ML16048A170

{{Adams | number = ML16048A170 | issue date = 07/07/2015 | title = FOIA/PA-2015-0294 - Resp 1 - Partial, Group a, Part 1 of 2 | author name = | author affiliation = NRC/OCIO | addressee name = | addressee affiliation = | docket = 05000397 | license number = | contact person = | case reference number = FOIA/PA-2015-0294 | document type = - No Document Type Applies | page count = 1434 }}

Text

{{#Wiki_filter:GROUP AFOIA/PA NO: 2015-0294RECORDS BEING RELEASED IN PARTThe following types of information are being withheld:Ex. 1 :L---l Records properly classified pursuant to Executive Order 13526Ex. 2:f- Records regarding personnel rules and/or human capital administrationEx. 3 :[---] Information about the design, manufacture, or utilization of nuclear weaponsE---]nformation about the protection or security of reactors and nuclear materialsE--iContractor proposals not incorporated into a final contract with the NRCE--OtherEx. 4:E-- Proprietary information provided by a submitter to the NRCV-]OtherEx. 5 :r- Draft documents or other pre-decisional deliberative documents (D.P. Privilege)El Records prepared by counsel in anticipation of litigation (A.W.P. Privilege)El Privileged communications between counsel and a client (A.C. Privilege)El OtherEx. 6:El Agency employee PII, including SSN, contact information, birthdates, etc.EThird party PII, including names, phone numbers, or other personal informationEx. 7(A):El Copies of ongoing investigation case files, exhibits, notes, ROI's, etc.ElRecords that reference or are related to a separate ongoing investigation(s)Ex. 7(C): *Special Agentor other law enforcement PIIr-]PII of third parties referenced in records compiled for law enforcement purposesEx. 7(D):f-lWitnesses' and Allegers' PII in law enforcement recordsEl Confidential Informant or law enforcement information provided by other entityEx. 7(E): ElLaw Enforcement Technique/Procedure used for criminal investigations[--]Technique or procedure used for security or prevention of criminal activityEx. 7(F): [] Information that could aid a terrorist or compromise securityOther/Comments: t -*

• l Agenda Introduction Presentation of Seismic Reevaluation Report SSHAC Activities Seismic Sources Ground Motion Model and Site Response Discussion of Interim Actions and Evaluations Flexible and Diverse Mitigation Strategies (FLEX) Seismic Analysis (PSA) Path Forward Introduction Energy Northwest followed the approved process for development of seismic hazard reevaluation for the Columbia Generating Station site in response to Enclosure 1 of the NRC's 1 O CFR 50.54(f) Request for Information Screening determination performed in accordance with endorsed Screening, Prioritization, and Implementation Details (SPID) (EPRI 1025287) Energy Northwest will present a detailed technical basis to demonstrate how process was followed and is prepared to discuss each of the technical focus areas

SSHAC Activities

• SSHAC Level 3 (SL3) conducted as "Hanford Site-Wide PSHA" with sponsorship from DOE and Energy Northwest
• Project planned and conducted to comply with NUREG-2117 and other guidance
• Roles and responsibilities of all project participants defined and adhered to
• Project-specific enhancements to SL3 process
• Participatory Peer Review Panel (PPRP) confirmed acceptability of both technical and process aspects of the project Hanford Site-Wide SSHAC Level 3 PSHA Purpose of Study: to develop a technically defensible PSHA that can be used for design and safety evaluations at the Hanford Site, Washington, including Columbia Generating Station PSHA must enjoy high levels of regulatory assurance, as indicated by a SSHAC Level 3 process Must provide outputs that allow use at multiple facility sites within the Hanford Site, including the CGS Outputs must be compatible in format with site response analyses for site-specific facility input motions Compliant with NRC requirements, per 50.54(f) letter, and regulatory guidance Compliant with DOE Order 420.1 B (later 420.1 C) regarding 10-year update and expectations of DNFSB SSHAC Guidelines and Guidance . . ***-.. NUR[(jlCJ:{ -6372 UCRL-ID-122160 Vul.1 Recommendations for Probabilistic Seismic Hazard Analysis: Guidance on Uncertainty and Use of Experts Main Report fur t:_s. :'\Llodt":.r C1unn*il'\1UH 1 .* lh*p:*rtm<*ll tir*:ru.*rgy t:ln'lrk l<<owt"r lni-fllUlt"' Practical Implementation Guidelines for SSHAC Level 3 and 4 Hazard Studies NUREG-2117 SSHAC Implementation Guidelines probabilistic seismic hazards analysis Project Plan for SSHAC Level 3 PSHA Project Plan specifies: Project organization Participant roles and responsibilities Scope Schedule Deliverables and instructions for usage Provided a basis for all project planning and contracting Ongoing information for participants and reviewers Recommended elements given in NUREG-2117 Hanford PSHA Enhancements New data collection activities PPRP participation Interfaces between seismic source characterization (SSC), ground motion characterization (GMC), and site response Selection Criteria for SSHAC Participants Tl Leads Tl Teams PPRP Specialty contractors Resource experts Proponent experts Hazard analysts l<nowledge Technical of PSHA expertise in SSC /GMC Objective & impartial evaluation Experience of SSHAC processes Bommer, J.J. and Coppersmith, K.J., 2013, SMiRT-22, Lessons Learned from Application of the NUREG-2117 Guidelines for SSHAC Level 3 Probabilistic Seismic Hazard Studies for Nuclear Sites Hanford PSHA --------------------------------------. PrOJ
• ect Organization Sponsors DOE-ORP, DOE-RL Dan Knight Energy Northwest Greg Lisle ... , Project Manager .... PPRP Project Quality Engineer Bob Bryce Ken Campbell. Chair Emily Wilson J. Carl Stepp Woody Savage Project Technical Integrator (PTI) Bill Lettis Kevin Coppersmith Brian Chiou I I I Project Technical Resources Hazard Analyst Data Base Manager A. Rohay V. Montaldo Falero D. Ward-Spatial Data C. Ross -Non Spatial Data ' I SSCTI Lead GMCTI Lead Kevin Coppersmith Julian Bommer I Specialty Contractors Specialty Contractors SSCTI Team GMCTITeam Resource Experts H R. Coppersmith L. Al Atik Resource Experts I !including R. Youngs) K. Hanson A. Rodriguez-Marek J. Unruh G. Toro I Proponent Experts L. Wolf R. Youngs Proponent Experts Seismic Source Characterization Team . ti I-. 1-+Kevin Coppersmith -Tl Lead +Lorraine Wolf + Kathryn Hanson +Ryan Coppersmith +Jeff Unruh
• Valentina Montaldo-Falero -Hazard Analyst
• Roseanne Chambers -PSHA document integrator
• Joe Lettrick-GIS data base manager Ground Motion Characterization Team + Julian Bommer -Tl Lead + Bob Youngs + Linda Al Atik + Gabriel Toro + Adrian Rodriguez-Marek Resource and Proponent Experts -WS1 Individual Walt Silva Carl Costantino Norm Abrahamson Tuna Onur Rob Graves Art Frankel Tom Hearns Alan Rohay Tom Pratt Brian Sherrod Rick Blakely George Last Harvey Kelsey Rex Flake Erick Burns Paul Thorne Bruce Bjornstad Pacific Engineering & Analysis Consultant Affiliation University of California, Berkeley Onur Seemann Consulting U.S. Geological Survey U.S. Geological Survey New Mexico State University Pacific Northwest National Laboratory U.S. Geological Survey U.S. Geological Survey U.S. Geological Survey Pacific Northwest National Laboratory Humboldt State University Central Washington University U.S. Geological Survey Pacific Northwest National Laboratory Pacific Northwest National Laboratory Resource and Proponent Experts -WS2 Individual Walt Silva Carl Costantino Norm Abrahamson Art Frankel Alan Rohay Suzette Payne Yousef Bozorgnia Paul Spudich Jennifer Donahue Dave Boore Olga Ktenidou Gail Atkinson Nick Gregor John Zhao AIRohay Tom Pratt Brian Sherrod Rick Blakely Marcia Mclaren Steve Reidel Judy Zachariasen Tyler Ladins Craig Weaver Affiliation Pacific Engineering & Analysis Consultant University of California-Berkeley U.S. Geological Survey Pacific Northwest National Laboratory Idaho National Laboratory University of California-Berkeley U.S. Geological Survey Geosyntec Consultants U.S. Geological Survey ISTerre, Universite Joseph Fourier-CNRS University of Western Ontario Consultant Institute of Geological and Nuclear Sciences, New Zealand Pacific Northwest National Laboratory U.S. Geological Survey U.S. Geological Survey U.S. Geological Survey Pacific Gas and Electric Co. Washington State University URS Corporation, Humboldt State University U.S. Geological Survey Participatory Peer Review Panel (PPRP) + Bill Lettis + Brian Chiou + Woody Savage + Ken Campbell, Chair + Carl Stepp Goal of a SSHAC Process "The fundamental goal of a SSHAC process is to properly carry out and completely document the activities of evaluation and integration, defined as: Evaluation: The consideration of the complete set of data, models, and methods proposed by the larger technical community that are relevant to the hazard analysis. Integration: Representing the center, body, and range of technically defensible interpretations in light of the evaluation process (i.e., informed by the assessment of existing data, models, and methods)." I NUREG-2117 I I NUREG-2117 Table 4-1. Summary of Essential Steps in SSHAC Level 3 and 4 Studies Essential Step Discussion 1. Select SSHAC Level
• Document decision criteria and process 2. Develop Project Plan
• Includes project organization and all technical and process activities 3. Select project
• Includes all management. technical, and peer review participants participants
• Includes compilation of existing. available data 4. Develop project
• Can include focused new data collection database
• Data dissemination to all evaluator experts (Level 4) or Tl Team members (Level 3) Workshop topics: 5. Hold workshops
• Hazard-significant issues and available data (minimum of three)
• Alternative interpretations
• Feedback 6. Develop preliminary
• Preliminary models developed prior to Feedback workshop model(s) and Hazard Input Document (HID)
• HID provides input to hazard calculations Table 4-1. Summary of Essential Steps in SSHAC Level 3 and 4 Studies
• Intermediate calculations should display the impact of elements 7. Perform preliminary of the expert models hazard calculations
• Hazard calculations should show the significance of all elements and sensitivity of the models analyses
• Sensitivity analyses should include the contributions to uncertainties
• Feedback provides a basis for prioritizing and focusing the 8. Finalize models in light finalization process of feedback
• Implement expert combination process across all evaluator experts in SSHAC Level 4 9. Perform final hazard Should be conducted to develop the required deliverables for calculations and
• sensitivity analyses subsequent use of the hazard results 10. Develop draft and
• Fundamental documentation of SSHAC process. technical final project report bases. and results 11. Participatory peer
• Periodic written reviews of key products and activities review of entire
• Review of draft report process
• Final written review of technical evaluations and process used

-m < 0 ::J Preparation of Work Plan Assessment of lr1 Team II PPRP I Preliminary Database)

• Hazard Significant ... Issues -------Resource 1: Hazard Significant _ Experts ,,_ Issues and Available Data ti111,1----t Resource Experts rl Additional Data Collection & Analysis I+-n Al :;o 't:I l'D -c: ., l'D l'D ,... ::T 0 (!) -0 .... Ill < :i -'11111 r; ID ;"' Workshop 2: Review of Database ..---g3 ""Cl Proponent .___--',M Discussion of Alternative Models o. o I I Tl Team Working Meetings (WM)
• WM1 Experts ...111 I <,_____ WM2 Databasel '11111 1 __________ _ -----------------------,, --------------. I Preliminary SSC and < ....... ..... -I + (!) -----------ID Preliminary HID :i ui 0 !2. . I -< Hazard Calculations and Sensitivity Analysis 0 WM3 (!) ... ii) Workshop 3: Feedback to Tl Teams ... on Preliminary Models .... :::a::::::::I .... :i I I Final SSC and GMC Models 1,,.-.__ __ ...... ro a. -----------WM4 0 ------------------------+----------Final HID and Hazard Calculations 0 ... 0 0 I Draft of Final PSHA Report c: 3 ... 11) ::i Review and Finalize PSHA Report -Ill -* s* :i I PPRP Closure Letter w c: *-----1 e. 3 0 ID ::J ::J *---UI ii L I -I -I., -I ,. I 4 days duration All team members Conference room with GIS support PPRP observers Requirements for SSHAC Level 3 PPRP PPRP Roles and Responsibilities Technical review: ensure that the full range of data, models, and methods have been duly considered in the assessment and all technical decisions are adequately justified and documented Process review: ensure that the project conforms to the requirements of the selected SSHAC level Provide timely perspectives and advice regarding the manner in which ongoing activities can be improved or carried out more effectively Be present at all the formal workshops as observers and subsequently submit a consensus report containing comments, questions, and suggestions Provide one or more representatives of the PPRP to attend as observers the working meetings of the Tl Teams Perform detailed review of all project documentation and provide written comments to ensure complete technical justification of integrated distribution Prepare PPRP Closure Letter providing final technical and process review I I Preparation of Work Plan Hanford PPRP lr1 Team II PPRP I Assessment of Major Activities Hazard Significant -, Database) Issues 0
• n Ill Workshop 1: Hazard Significant Ill :;o Review of Project Plan and -Resource "'C l'D Ill --s. C" Experts ... Issues and Available Data " c: attendance at Kick-Off m Ill ., l'D Ill l'D < l'D -0 ... , Additional Data Collection & Analysis I+-::r 0 c: (I) -Ill l'D en < n l'D {WM1} Ill en Full PPRP present at all 3 0 0 Resource :i :I: = -J> "'C ,,, l'D 3 Experts -;"' n Workshops l'D , Workshop 2: Review of Database 1...-OJ ""Cl = Proponent 0 ., .... , Discussion of Alternative Models 0 Q. t"> Experts (!) Ill PPRP representative as Ill _Ill Final Database I = Q. observers at all 8 Working :;o Ill n -----------------------------------= --. ::r Meetings IC = Preliminary SSC and tD n 0 GMC Models -OJ , -I + II) Ill (") I/I PPRP encouraged to ::r l'D Preliminary HID ::J (/I :l" 0 0 interrogate Tl Teams on -... Ill J> <O I -< I/I their preliminary models at ., Hazard Calculations and Sensitivity Analysis Ill 0 I/I .... l'D c;* ... l'D I/I WS3 -I/I = l'D 3 Workshop 3: Feedback to Tl Teams j :I -l'D on Preliminary Models = !l: -l'D I/I y ..._WMij Ill PPRP Briefing to review ::J I -Q. Final SSC and GMC Models l'D , * ., 9 Final SSC and GMC models ------------------------+------"'C ... " c: Final HID and Hazard Calculations I>> 3 e. 0
• 0 l'D ::J ::J Review of Draft Report 0 Ill -n I Draft of Final PSHA Report I -II.I -c: c;* 3 * ::i Review and Finalize PSHA Report I J -Di I., ---. c;*
• Preparation of PPRP ::J I I ,. PPRP Closure Letter I Closure Letter -----

PPRP Closure Letter November 15, 2014 The Tl Teams were responsive to the questions, comments. and suggestions made by the PPRP relative to the technical aspects of the project. Therefore, the Panel concludes that the technical aspects of the projects have been adequately addressed. Conclusion On the basis of the PPRP's review of the HSW PSHA, the Panel concludes that both the process and technical aspects of the assessment fully meet accepted guidance and current expectations for a SSHAC Level 3 study. We appreciate the opportunity to provide our review of the project. Sincerely. HSW PSHA PPRP Members 1,.; . G..""f Kenneth W. Campbell Chair 1 I ' . ),1 (* -. '-William U. Savage HSW PSHA PPRP Closure Letter Brian S.-J. Chiou r/Cdl:ifar J. Carl Stepp William R. Lettis Page 5

2 5 5 tO -Hanford Site-Wide SSHAC Level 3 PSHA 15 465!>4548 LM9 *119517907) B -We$! Area 1La1 .:6 Loo;; -11(1 &250631 C -Co'""'D*a Stat on (lat 47 It 88 lor.9 -19 )34 I 70i D. tC06Ct.rea .:(j(iJ0376 Long .119647486> E. 3:0A*Ci'l 1Li\1 46 3&8604. Long -119 :;>'7461 I SSC-Related Activities Compilation of extensive geologic/geophysical/tectonic database Update and analysis of earthquake catalogs: crustal and subduction zone Identification of seismic source zones and future earthquake characteristics Structural geologic and Quaternary analyses of Yakima folds Assessments of behavioral characteristics of fault sources including segmentation and slip rates Incorporation of associated uncertainties, including both aleatory and epistemic components Seismic Sources in SSC Model Cascadia Subduction Zone sources Plate interface lntraslab source Seismic source zones YFTB zone: serves as a "background" zone to fault sources Zones B, C, and D Fault sources within Yakima Fold and Thrust Belt (YFTB) 19 faults characterized More distant faults are implicitly included in source zones New Data Collection and Analyses Focused studies and analyses designed to reduce uncertainties in key SSC and GMC issues, within the project schedule and budget GMC-related Velocities at recording sites Analyses of kappa Analyses of basin effects SSC-related Structural analyses of Yakima folds Quaternary geologic studies High-resolution earthquake relocation analyses Seismic Source Characterization, Focus Area 1 1. Summarize the information used to constrain the slip rates on the YFTB faults, including: a. Methodology used to evaluate fault slip from topography including associated uncertainties in the ages and offsets. c. How potential effects of surficial erosion were accounted for in the use of an average topographic profile to represent structural relief in individual faults. Pertains to these sections of the report Section 5.2.1 Structural Analyses Section 8.4.3 Fault Characteristics Included in the SSC Model Appendix E, Section 5 Evaluation of Long-Term Structural Relief Steps in Characterizing Fault Sources Measure topographic relief along lengths Define segments for use in estimating Mchar, Mmax Alternative rupture length, area relationships Identify polygons on DEM defining fault-related deformation within seismogenic crust Compare topo relief with structural relief from boreholes: Agree. Define fault dip and uncertainties, given mapped fault location, seismogenic thickness, and polygon Max, average, 60°/o of polygon width defines uncertainty in fault dip and downdip width for given thickness Include geologic indicators of style of faulting to derive net slip Alternative start times of deformation 1 Omy, 6my for slip rate Compare with Quaternary rates where known: Agree. Steps in Characterizing Fault Sources (continued) Magnitude frequency distribution model Compare with fault-related seismicity: Characteristic earthquake model supported Incorporate recurrence interval data, if available Renewal model: elapsed times and alpha unknown Future ruptures: magnitude-dependent rupture areas, lengths can extend across segment boundaries Topographic Analysis of Folds: Defines surface evidence of fault-related deformation within seismogenic crust I.* .. 'It . Ma:Jntcii:i Q 4.[00 3 ooo Ooll

• 4.GOO is.coo :':'Dm norn lml 10 (* K:lomt:crs ---f:C ! " a ;x . ... ---------* <.vV e Horse Heaven Hills Base level Di\tanc* lml 400 m Identification of Polygons & Possible Segmentation Points ... ._:.... -.. '.,;;. 30 .' ./ J(:(J.) f:<,c:-::* *i ! . "'*Jl' . 2 'ii t**.:1,.1 )(:*J .', Yakima Ridge West-Yakima Ridge East ;:.;(:(I(.(} Ditt*n<* (m) Umtanum Ridge-Gable Mountain l*IJ(1'.X,\ 0.*tance 3C t*JL".t':Xl .. . I *-' .... ,' . . . * :*. j : : ,ir** ... : .; ........ ' ./. -.. , **_,,r., * .AJP;:* *.**.' .. *-!* "i.*".-. i* -.. *I.. 15 0 30 K1lomt"terr.i:'T"< J .

Comparison of Topographic Relief with Structural Relief --.. *4$"0*N .. 0 ..... , ... ...._iio o 0 * ."" '* , .. 0 *.*

• i;.f-; *u . 0 0 r. **-. -** ,*. .. QI 0 * . .. *._ 0 .. .. 0 .,.., (I ----119'"30'0'W ......... : ........ , ... '.*.'""I Pralile 2 111*30'0.,,.,.
• 0 . . a a o . .. 11.*(l Saddle Mountain Profile 1 :. l/t;'t.... _! __ -! :i_...-/ ---I>-* ------_-_-_:------* Saddle Mountain Profile 2 " -D*--IC\ll' ' 1.>\'lo)'o Legend 0 GPS :,,.'3 -AS!i. .. r;* .1pp:r CRB Mean Structural Relief *Shape of segments and slip distribution is likely the result of repeated rupture
• Average is appropriate for assessing slip rate when have multiple measurements along a fault segment Fault Source I Ahtanum Ridge Cleman Mountain Columbia Hills-Central-East Columbia Hills-East Columbia Hills-West Columbia Hills-Central Columbia Hills-Central-West Frenchman Hills-East Frenchman Hills-West Horn Rapids Fault Horse Heaven Hills-Central Horse Heaven Hills-Central-East Horse Heaven Hills-Central-West Horse Heaven Hills-East Horse Heaven Hills-West Manastash Ridge-Central Manastash Ridge-East Manastash Ridgt:-West Rattles Rattlesnnke Hills Rattlesnake Mountain Saddle Mountains-East Saddle Mountains-West Selah Butte Toppenish Ridge-East Toppenish Ridge-West Umtanum Ridge-Central Umtanum Ridge-East Umtanum Ridge-Southeast Anticline Umtanum Ridge-West Umtanum-Gablc Mountain Wallula Fault Yakima Ridge-East Yakima Ridge-West Yakima Ridge-Southeast Fault Arronym I Meau Structural Relief (m) AR 330 CM 650 CH-C-E 55 CH-E 105 CH-W 375 CH-C 135 CH-C-W 230 FH-E 155 FH-W 155 HR 90 HHH-C 485 HHH-C-E 415 HHH-C-W 575 HHH-E 205 HHH-W 270 MR-C 300 MR-E 145 MR-W 415 RAW 130 RH 335 RM 619 SM-E 320 SM-W 335 SB 460 TR-E 300 TR-W 310 UR-C 360 UR-E 250 UR-SA 90 UR-W 400 U-GM 160 WF 250 YR-E 325 YR-W 250 YR-SE 65 Uncertainty in Dip Included in Logic Trees : Saddle Mountain topographic width= km 800 700 600 & 400 "G : .300 :!! -200 100 0 0 i Dip at 13 km= 52" I Dip at 16 km= sr ; Dip at 20 km= 63" 1000 4000 6000 8000 10000 13 km 16 km 20 km oo HOOO 20000 nooo 26000 Topographic Analysis of Rattlesnake Mountain -60% of average topo width= 13,200 m -Average topo width= 22,000 m _______ _.-Max topowidth = 34,000 m 13km--20km--------* -----*. ---------;******* *'*< Dip range for 16 km depth 2s* to so*

Logic Tree Elements Related to Slip Rate SEISMOGENIC THICKNESS 13 Km [0.)) lb Km {O. '>) JO Km [0.3J .,., . <;ource specifi( BASIS FOR FAULT DIP M.1x Polygon Width [O.JI l\vt* Polygon Wicilh [O.'"il l..>0% of Aver c1g<> [CUJ FAULT SEGMENT 111111-LlSI rn111 u*n1r.111.1.-,1 Llmt.11H111l (i.lblt' Mtn Um!.ll\lllll ( enlr .11 * *

• SEISMOGENIC PROBABILITY Not \t>i'>rno <'nic [wt '>'>) '>l'i'>mog<>nic (WI'>'>) STYLE OF FAULTING Ht*Vt'I')(' {wt '>'>) Obliquc> (wt '>'>I \tr i kt> <,lip I wt s'>I
• FACTOR FOR NET SLIP l.O [Ul) 1.4 It 01 ),} I0-'11 10.*)1 START TIME 6My [wt '>'>] tOMy lwt .,., I NET SllP RATE Rc1t<* X I wt '>'>I R.1h* Y [wt s<.J * *
• R.lll' n Logic Tree for Rattlesnake Mtn Fault Source FACTOR FOR APPROACH QUATERNARY NET SLIP TO SLIP RATE RATE START TIME NET SLIP RATE 0.0 [O 101081 1.0
• 0.041<J R.Ht* X 11.01 [O J4'1)(JI !wt I <ll1.1t<>rn.uy D.11.1 0.CW)/ R.1tt> Y (0.11 [O. W9l<*J [wt I
• 1.4 10 /4419) * * [t.O) * [010108) R,l!(* n ) ) bM [O.'>>) 10.11 u<t ur .11 Rl'lit*f (O '*.1 to My [O '>) (O .3]

..... 8 Net Slip Rate Distributions 0.8 O.b 0.4 (J.) () i.001 m Yakima Ridge ' . ' ,I :1 1.001 ()} 1.00I 01 Slip Rate (mm/yr) 1.001 *00 --YR\I --YRI --YRW Rattlesnake Mountain 0.8 0. {, ..... e 0.4 0) 0 1.<XH Ol 1.00[ ()) 1.001 01 1.00! *00 Slip Rate (mm/yr) --HM --( ompo<. ih' Seismic Source Characterization, Focus Area 1 1. Summarize the information used to constrain the slip rates on the YFTB faults, including: b. Rationale for excluding thin skinned seismo-tectonic models. d. Bases for excluding listric fault geometries or potential for backthrust structures in structural relief model. Pertains to these sections of the report Section 4.1 Tectonic Setting Section 4.4.1.2 Instrumental Seismicity Section 6.3 Epicentral Locations Section 8.4.3.4 Fault Dip Appendix E, Section 6 Kinematic Analyses Using Earthquake Focal Mechanisms Thin-skinned vs. Thick-skinned Thin-skinned model called for mechanical decoupling of faults within Columbia River Basalts with those in crystalline basement Former proponents for those models participated in WS1 and WS2 and have abandoned that model Multiple arguments for discounting thin-skinned model are given in pp. 4.5 to 4.1 O Additional support was provided by high-resolution earthquake locations, which show no lack of seismicity at sub-basalt sediments Focal mechanisms in CRB and crystalline basement show comparable styles of faulting and stress orientations Geophysical properties of sub-basalt sediments suggest that they are not mechanically "weak" Listric Fault Geometries Listric geometries were not explicitly "excluded" A planar fault is the simplest geometry and is consistent with the back-limb geometry of essentially all of the YFB folds Historical large-magnitude thrust earthquakes show essentially planar rupture surfaces Backthrusts would have been included if there was good mapped evidence for their presence, and that they extend to the base of the seismogenic crust (i.e., are not confined to shallow depths in the hanging wall of another fault)

GMC Approach Use appropriate GMPEs to develop distribution of predicted ground motions Select and appropriate GMPE shape to use as a backbone model Develop distribution of scaling factors to adjust the backbone to represent the distribution of predicted motions Develop scaling factors to adjust for unique site conditions at Hanford Hanford Profile Several 100 feet of sands and gravels, some with cementation Sequence of basalt flows with well defined and relatively thick sedimentary interbeds -Saddle Mtns Basalts and Ellensburg Formation interbeds Several km of more massive basalts, Wanapum and Grand Ronde Several km of sedimentary rocks above crystalline basement rocks o_ 100 200 300 400 500 t-600 UJ LU LL 700 I I-0. LU 800 Cl 900 1000 1100 1200 1300 1400 1500 _ I . t: RINGOLD FORM&.TION 130' 250' f I/) z z :J 0 ::2: w _J 0 0 <( U) A\ 0 Selection of Reference Horizon for Site-wide Study Initial concept to use top of SMB/lnterbed sequence However, site response analyses indicate that treatment of the SMB/lnterbed sequence as a halfspace produced different surface motions than obtained from explicitly modeling basalts and interbeds Reference horizon moved down to top of massive Wanapum basalts (top of Lolo flow with flowtop removed) Implications for Downstream Site Response Analyses Assessment of baserock properties required assessment of properties of overlying SMB/lnterbeds In order to maintain consistency in downstream use of baserock hazard, properties of SMB/lnterbeds specified for use in site response based on properties used to develop GMC Uncertainties in damping within SMB/lnterbeds incorporated into uncertainty in baserock hazard in order to minimize computation burden for subsequent analyses. Crustal Earthquakes GMPEs Primary sources of hazard from shallow crustal earthquakes are reverse and reverse-oblique faulting mechanisms for sites that may be located in the hanging wall Selected candidate models that best represent these types of earthquakes -NGAW2 models, particularly those that explicitly include HW effects Select one of the candidate models to use as the backbone Compute distribution of ground motion predictions from candidate models relative to the selected backbone model Develop distribution of scaling factors to center the backbone model and represent the distribution of ground motion predictions First develop footwall model using ASK14, BSSA14, CB14, and CY14 GMPEs Compute predicted ground motions for a range of magnitudes, distances, fault dips, and depths to top of rupture Compute residuals for all of the predictions as residual = ln(PSA)_i -E[ln(PSA) for 4 NGAW2] for all 4 NGAW2 models Represent epistemic uncertainty in adjustment from CY14 by a mixed effects model L1 ln(Y) = clF + C2F {M -6.5} + clR,f(M) + C2R {M -6.5} Fixed coefficients represent change from CY14 to average of selected 4 NGA West2 GMPEs Random coefficients represent variability in scale factors from individual GMPEs to average Represent Distribution of Scale Factors Discretely Use period independent scale factors for T <= 2 seconds Scale factors nearly period independent for periods that contribute to hazard Allows use of a common Vs-kappa correction Use 9-point approximation of 2-D Gaussian distribution Account for correlation between random scale factor and random adjustment to magnitude scaling Resulting Footwall Models "' 0 0 c:i MS.5 ,Rx-5 km Centr .. 1 8eickbone --Epistemic MoaP.ls SL_ _______ __J ........ .u...J.L_.._1-..1_,_,..., 0 "' c:i § M7, Rx -5 km c:i -Centr .. l 8eickbone --Epistemic Models om 0.1 o.3 10 O.o1 Period (s) M6, fl'y -5 km Centr<1l 8ackbone --Epistemic MoaP.ls M 7 5 ,Rx -5 km -Centr<1l 8ackbone --Epistemic Models 0.03 0.1 0.3 Period (s) 3 W0.01 M6.5,Rx-5 km Centreil 8ackbone --Epistemic Moaels M 8, Rx -5 km -Centreil Backbone --Epistemic Models 0.03 0.1 0.3 Period (s) 3 10 Develop Hanging Wall Adjustments Use ASK14, CB14, and CY14 HW factors Compute average scale factor for RJ8 = 0 sites as difference between mean HW factor [in lnPSA)] and CY14 HW factor Model HW adjustments with function form HWadJustment = [1+ p4 cos(O)]xln[p5 cosh{p6 max(ln(Rx I p7),0}] Compute coefficients for mean adjustment and sigma of adjustments Add the mean adjustment to the mean FW adjustment RSS the HW sigma and the sigma of fitting the mean adjustment in with the FW random C1 component Crustal GMPE Logic Tree Backbone GMPE CY14 ( 1.0) Vs-K Adjustment Factors V K-7 s (0.(155) V K-6 s (0.136) V K-5 s (0.198) V K-4 s (0.222} V K-3 s {0.198) V K-2 s (0.136) V K-1 s (0.055) Inherent Uncertainty in Backbone Adjustments [llln(Y) I M]9 (0.0625 I [llln(Y) I M}8 (0.0625) [llln(Y) I Mb (O.fi625) [llln(Y) I M]6 [81n(Y)IM]5 (0.50) (llln(Y) I M]4 (U.Ot:i2:,) (llln(Y) I Mb (0.0625) [81n(Y) I M]2 (0.0625) [llln(Y} I M]1 (0.0625) Host-to-Target Uncertainty Factors 1.3 jll.3 J 1.0 (0.6) 0.8 (0.1) Subduction Zone GMPE Selected backbone model BC Hydro model (Abrahamson et al., 2014) Developed as part of a SSHAC Level 3 study as a response to shortcomings of existing relationship Global dataset Includes epistemic uncertainty in magnitude scaling Includes forearc/backarc scaling Modifications to BC Hydro GMPE to Address Ground Motions at Large Distances Modify dataset Re-evaluate censoring of data Additional data (KiKnet, Arango et al. for Central America, Maule EQ) Remove Taiwan data for sites where forearc/backarc is unknown Use Arango et al. data for El Salvador Earthquake Exclude Tohoku mainshock and aftershocks Attenuation rate at high frequencies is high -low motions at large distances Still used to constrain epistemic uncertainty in large-magnitude scaling Modifications to BC Hydro GMPE (2 of 2) Modify functional form controlling anelastic attenuation Assess modified model coefficients applying higher weight to data at distances > 200 km Include forearc/backarc scaling uncertainty Nisqually earthquake data from Hanford site consistent with BC Hydro backarc attenuation predictions Regions other than Japan do not show clear difference in forearc/back arc, but data is often limited Numerical simulation based model of Atkinson and Macias (2009) derived using a Q model similar to that of Phillips et al (2014) for the Cascadia-Hanford travel path show low attenuation similar to BC Hydro Forearc model Subduction Zone GMPE Logic Tree Sackbone GMPE Back-arc () *. O} Scaling [.&Cl] med+ 0.2 (0.2) [8C1]med (0.6.J med -0.2 (0.2) Scaling on Anelasttc Atten uatlon Term 0.5 06 ( 0.4) Ss ( 0.6) Epistemic Uncertainty in Median x1.62 (0.2) x1.0 ( 0.6) x0.62 ( 0.2) Host-to-Target Vr:. Adjustment Factor* Vs factor-4 (0.335) Vs factor-3 (0.165} factor-2 (0.335} Vs factor-1 (0.165) Adjustments to Hanford Baserock Conditions For Crustal GMPE adjust for Vs and kappa For Subduction zone GMPE adjust for Vs only Vs and Vs-kappa adjustments made using the Inverse Random Vibration Theory Approach of Al Atik et al. (2013) GMC, Focus Area 2a: Provide additional detail on the Vs-Kappa corrections applied to the scaled backbone GMPEs -Rational for not applying a kappa correction for the subduction zone GMMs Hazard sensitivity analyses indicated that the distant, large magnitude Cascadia subduction zone interface (CSZ) earthquakes primarily contribute to the hazard at low frequencies where the effects of kappa are small Because of the large distance to the CSZ (>200 km), the effects of Q are expected to dominate over the effects of kappa. Therefore, incorporation of uncertainty in Q was the focus Because the subduction zone GMMs are defined primarily by data at large distances, separation of kappa effects from Q effects in the host GMMs is difficult. GMC, Focus Area 1 (1of10) Provide additional detail on the process used to define the target site kappa values and their uncertainties, including the rationale for logic tree wefahtinas. Utilize recordings of small earthquakes from 6 sites located on basalt or a few meters of soil over basalt to assess kappa for basalts Some sites located on SMB with interbeds, some on outcropping layers of deeper basalts Apply alternative approaches to estimate site kappa and its uncertainty Inversion of Fourier spectra of recordings Anderson and Hough (1984) Apply kappa estimates in forward sense considering uncertainty in contribution of deeper sediments to kappa for large earthquakes GMC, Focus Area 1 (2 of 10): Target site kappa Target kappa logic tree 1.11\:d *. Uncertainty in Vs : .II:.'.'!{ !>11 *!ii-: .\p1*n* .. 1 ... i1 h* I* ,11::1.11-: : 1,\ :1hi:;-.\J1p:l'.ld1 1-'a*!ilt" I *:k profile l. : . 1.11:11: Alternative ' , . '1 I approaches Uncertainty in Pr.*:'::c I ir1h*r':*ll1\ *:. All '>:ti estimates from each . '* . approach '-:. l . . . Uncertainty in depth . : range contributing to .. 1 h-kappa for larger Pr* I:;: earthquakes ... ,,,,, J ,t....:, h. '.l.'h '*' s.-,! I I -.s : I *:.-i '_*' GMC, Focus Area 1 (3 of 10): Target site kappa Alternative Vs Profiles Differ in SMB Vs Differ in subbasalt sediment Vs Favor Profile 1 2:1 over ! j E -Profile 2 -prefer downhole Vs measurements over ._ suspension logging in basalt Difference in subbasalt Vs had small impact on assessments V!. (km/sec) j ' -{ \ I \_j :,.1 --:.-: (. :

• L)* l l 1 -' ! -E .J:. <. Q. -c. 0 : ::* J\.:. ----*-15 !. (km/sec) I j \ ---*----I \ I I \ . . I \ . *--* --(. !. . . . ! l*!.

GMC, Focus Area 1 (4 of 10): Target site kappa kappa estimated by inversion Used recordings from 15 earthquakes recorded in 2005 to 2013; 10 recordings at HAWA from 2004 study Hypocenter depths 5 km to avoid double paths accelerograph recordings at HAWA; all other recordings were on BB velocity instruments Inversion process estimates kappa along with source (fc) and path ( Q) parameters by nonlinear least-squares fit to FAS using source model was fixed at due to limited distance range and limited bandwidth Determined parameters: fc, kappa GMC, Focus Area 1 (5 of 10): Target site kappa Assessed correlation of kappa assessed from inversion with: Thickness of SMB Total thickness of interbeds Thickness of subbasalt sediments Conclusion that entire profile above basement contributed to kappa from the small, deeper earthquakes * * * . ' . (> . ' . .-.. : .... *.*; *.. * *. ... * ... *'-' . .. . ' *\ 0.

• t. ' . lit .. .'* ., .... TIX.ti Thld.n.;*u of F:lv1>*.bu1g rorm.ttloti lnt*rt>.d-. ( m) * *. ,,,:. *. \* .* r, . **h . I; . . .... -1 * * . 0. 0. ... : 1-.
• I . ' ., . I * * * * '. ' .*.I
• 0 0 * * * * :.* .. f* -*. ****** * :n::
• 0 * *
• GMC, Focus Area 1 (6 of 10): Target site kappa Anderson and Hough (1984) approach: Select data for R < 200 km that show linear trend in FAS at high frequencies Select frequency window for linear trend Smooth FAS and noise with Konno and Omachi (1998) filter Select records with signal to noise ratio > 3 Estimate kappa by fitting a( Extrapolate trend with distance back to 0 distance 0.1 . O.O'J . 0.08 : ()<JI * (l()I,. O.<H -0.(l/.; ()Ol . (). tl ; 10' ! 10 0 y 11 !*' * (I (.l.1.1*.* I) 71:11*1 !1: :l.i i'*' -JI) -'. Vector Sum : : -k0.049014 . 50 100 Frequency (Hz) ---.. (>l> 80 JI.JO R(kmJ 1\11'1 ( nn c nrt 'l'Nl \!T1* c nr: HAI r1 t GMC, Focus Area 1 (7 of 10): Target site kappa Assess site kappa removing effects of shallow soils and scattering from SMB interbeds Soil kappa assessed using Campbell (2009) Scattering kappa assessed by comparing response of an equivalent uniform Vs profile with damping to layered profile without damping Assuming Qs = yVs develop estimates of y to assign kappa to SMB and to deeper layers Based on K = H/Vs/Q GMC, Focus Area 1 (8 of 10): Target site kappa Favored inversion over A&H 2:1 Based on fit of broader frequency range of FAS A&H produced variable assessments of Os Application of A&H method required use of shallow earthquakes with potential multiple paths Epistemic uncertainty in A&H kappa assessed based on statistics of fit Epistemic uncertainty in Inversion kappa based on assessments of parametric variations in inversion parameters Produced an asymmetric distribution In addition, best estimate kappa based on Q(f) larger than Phillips et al. (2014), thus may be biased high. Weights adjusted to account for potential bias (lower Q would lead to lower kappa)

GMC, Focus Area 1 (9 of 10): Target site kappa Final component -depth extent of subbasalt sediment contribution Results for small, deep earthquakes indicates all of sediments No data available to assess contribution for shallower earthquakes or large earthquakes Considered three equally weighted alternatives All, half, or none GMC, Focus Area 1 (10 of 10): Target site kappa Resulting baserock kappa distribution Site C 0.2 -0.15 *-(!) 0.1 0.05 0 Kappa Bin GMC, Focus Area 2b: Provide additional detail on the Vs-Kappa corrections applied to the scaled backbone GMPEs -Comparison of the Vs-kappa scaled median GMPEs and NGA-West 2 models M 7, Rrup 11 km, HW 0 0 LO Red curve -Median Crustal g for V530 760 Black curves -Median Crustal scaled by Vs-kappa corrections <!'. (/) Cl. ...... 0 LO ci 0 ,.... 0 LO 0 ci ,.... 0 0 ..........,..__ ___________ ___. 0.01 0.05 0.10 0.50 1.00 5.00 10.00 GMC, Focus Area 2c: Provide additional detail on the Vs-Kappa corrections applied to the scaled backbone GMPEs -Whether any observational data from the region was used to assess the Vs-kappa corrected GMPEs Available ground motion data from small crustal earthquakes in the region recorded on basalts or shallow soil over basalt were used to assess kappa Recorded crustal earthquake data is generally from earthquakes too small to make meaningful comparisons with the developed GMPEs Data from the M 6.8 Nisqually earthquake was used to assess attenuation from distant CSZ earthquakes Aleatory Variability Model Utilized single station sigma concept Development very similar to that of the SWUS model with similar results Specified minimum level of epistemic uncertainty in characterizing site response to address: Lack of variability in site response at very low frequencies Possible basin effects in surficial sediments at intermediate periods GMC, Focus Area 3: (1of5) Provide additional discussion regarding bases for bump seen at T 0.1sec in the mean tau values for the NGA-West2 models and the decision for smoothing through this peak in developing single-station . sigma. A peak in the event-to-event variability (r) is commonly seen in the results of analyses of empirical strong motion data r is a measure of the differences in the average motions from earthquake to earthquake May be due to source differences May be due to differences in average site conditions for each earthquake Possible mechanisms for peak explored Using point-source stochastic simulations Examination of data from limited geographical regions GMC, Focus Area 3: (2 of 5) Bump in rat T o. 1 sec. Performed point-source stochastic model simulations Random variation in stress parameter (stress drop) Random variation in site K Simulated motions 200 earthquakes with lognormally distributed stress drops For each earthquake, ground motions at 25 sites with lognormally distributed site K Fit results with mixed effects model to compute variance components r and cf> Two cases analyzed No correlation in site K between earthquakes --produces a peak in cf> (within event variability) but not in r Half of the variance is assigned to event-to event variability in median K and remaining to within-event site-to-site variability in K--produces a peak in both r and cf> GMC, Focus Area 3: (3 of 5) Bump in rat T 0.1sec. ..... 0 Results of fitting mixed effects model to simulations I .,.._ ' ' ' ' ' .... ..... No kappa correlation with EQs Tau Phi Total. RE Fit ..... ..... ..... .... ... ---a> 0 co 0 E '1) 0 II) ---I .... -..... .... ... --.... .... ...... .... .... -... ..... ------kappa correlation with EQs Tau Phi Total. RE Fit -, ... .... ... ... ... ---'<r. 0 ----------------------*:t 0 ---.... ---.... .... --------------"' 0 N 0 0 I 0.01 0.03 0.1 0.3 Period (sec) --...... ...... ' ' ' ' ' ' 10 N 0 0 0.01 O.O:J 0 1 --0.3 Period (sec) ---...... ' ' ' 3 ' ' ' 10 GMC, Focus Area 3: (4 of 5) Bump in rat T 0.1sec. Fits to CY14 'i"' M <. i::::; *I I I II f residuals for IJ.J * :11h :d I R111Ju1 1 [fi:1..: ,......

• Jo:I* :a 1 .:me ::tat en Rane cm [ffe::: only California ...., data (I ... Inclusion of site-" "' to-site variability l-4 " term shifts peak I ' I II 11 l at 10 Hz from r ol I I I I I ii II I ) (1 [ )3 O.' 03 3 10 to ¢525 for Pe1ioJ (5) M < 5.5 N
• 1 II" I Less conclusive r.u * :11h :d I R111Ju1 1 [fi:1..: "
• Jo:I* anc Jtcit en Ranccm [ffe::: for larger M, but ...., limited data (I ... from sites .... " recording multiple l '4 ,, " earthquakes ol I I I I I i( II I I I I I I 11 I ) (1 ()3 O.' 0.3 3 10 Pe1iod (5) -JI ..... , 11111111 -1 11111-1 , 1 *111**i* w n ... w n * ... n
• 4roul * ,, h, 0 CO' JC: I II II I r
• 1 ", 1 I J I I I II 0.1 C3 3 1( * * , , 11111
• 1 , 1 .. , ., , 1 -1 "-11 M I I n 0 CO' I I I II I II I 0.1 I I I II I I I l I I I II C.3 3 1(

GMC, Focus Area 3: (5 of 5) Bump in rat T o. 1 sec. Conclusion -peak in r near 10 Hz (0.1 s) likely due to differences in average site conditions from earthquake to earthquake rather than variability in earthquake source properties Uncertainty in site effects for Hanford sites is explicitly addressed in development of GMC model Therefore, peak in r is smoothed through in developing aleatory variability model Provided Recommended Vertical/Horizontal Spectral Ratios for Development of Surface Vertical Spectra 1.5 -GA2011 Gulerce and Abrahamson (2011) modified at long periods to match trends in data from the Maule earthquake .. -.. -GA2011 modified en ..... (.) 1 <l> (/) c 0 N *c 0 I I 0.5 .9 ...!.. ro (.) *-t (I) > 0 0.01 0 1 1 Oscillator Period (seconds) I / I / I 10 Baserock Hazard Results at Site C -CGS SiteC 10°-------10, r ............ . ... *-* -....... __ . ** *-*-* ---* **-*-* -...... _..1 ..... --*---10" 10' 101 1011 Peak Ground Acceleration [g) 5th ---16th 50th ...... ********* 84th 95tt1 -meanTOT. GI u 10" i 10' "ti GI GJ 101, w 0 10* c . GI ::I er 10 LL. "' 10" c < 10 SiteC 10* 10'.I 10' 10 I io*' 101 T1 .OOsec Spectral Acceleration (g) 5th SOlh -841h 951h -meanTOT, Source Contributions QI CJ c "' "Cl Cl.I QI CJ )( w -0 SiteC 10° 10 10 10 10 'r 10 10"' 10*1 io*2 10* 10° 101 Peak Ground Acceleration [g] ZONES --FLTS --csz --JDF -TOT 10" QI CJ c 10 "' "Cl OJ Cl.I CJ 10 :1; )( w -0 SiteC 10 4 10*1 10*2 10*' 10° T1 .OOsec Spectral Acceleration [g) 10 ZONES I --FLTS --csz --JDF -TOT Contributions to Uncertainty (1 of 2) Site C (CGS) -Peak Ground Acceleration 100% -8 90% c D 10-3 AFE *10-4 AFE .9 80% ... Cl > 70% o 10-5 AFE

• 10-6 AFE 0 60% CJ 10-7 AFE c 50% G> u Ir> 40% CL 30% 20% 10% 0% -J -.Al 0 */ ... , ... ': ... . ,. *:* \ .... .<* * * ,. ...... ,:.

Contributions to Uncertainty (2 of 2) ! i "C > -I -0 Site C (CGS) -T 1.0 sec SA 100% o 10-3 AFE 90% *10-4 AFE 80% o 10-5 AFE i------lO%

• 10-6 AFE a 10-7 AFE 60% 50% :. 40% 30% 20% 10% 0% ...... L......p!L&L.+ 0 */ ... , ... ': ... . ,. *:* \ .... .<* * * ,. ...... ,:.

Development of Input Motions for Site Response Deaggregated mean hazard at each frequency Developed 4 scenarios to represent deaggregation M, Rand weight of event . vanes Developed conditional mean spectrum for each scenario 101 CMS 10° i 0-. 10 / . ' 0 ;f. "' 10 l Frequency [Hz I 1.0 Hz, AEF: l .Oe-04 -UHR!'> -*.1 '>.6, R: 7 krn, Wt: 0.1'.> '.I R 11 km. Wt: 0 39 '.I . l.l, R: 20 krn, Wt. ->./

• 9.0, R: 3.16 km, Wt* 0.21

Site Profile Site profile consists of two zones: Upper sands and gravels (525 ft thick) Sequence of basalt flows (765 ft thick) to top of Lolo Flow Sand and gravel properties based on FSAR data Basalt flows characterized in PSHA study Simulated profiles generated for each zone and then joined 2 i-w LU LL J: i-a. LU 0 0 100 200 300 400-500 600 700 800 900 1000 1100 1200 1300 1400 1500 t: 1-RINGOLD FORMATION 130' 250' f III (/J z z ::J 0 w ....I 0 0 ;:3 1345' nv RON !;: (/J<( INTERBEO 5* Z nso* <( Labeled depths not for CGS 0 Upper Sands and Gravels Profile Velocities obtained by hole and down-hole measurements at CGS (formerly WNP-2) and nearby WNP-1 and WNP-4 Considered: one velocity profile with cr1n 0.15to0.30 EPRI and Peninsular Range (PR) nonlinear curves (D s 15°/o) GSU 440ft .,H T-: 350 .__.___ ___ 250 g c: 150 .. > ..!! ... 50 *50 -150 I Middle Ringold I :, :, :. :.. '1 -----__ [ I --------' I Saddle Mtn Basalt I ***** WNP-1 CH WNP-/ CH WNP-4CI< \VlllP* 1 OH * *WNP-JOH * * * *

• LO\\ler Bound --*Upper Bourid 0 1000 2000 3000 4000 5000 6000 7000 V,(fps)

Site response, Focus Area 1 a Provide additional detail regarding the bases for only a single profile for the upper 525 ft. The geology and depositional processes are also known from the nearby DOE facilities in Hanford (e.g. WTP) The soil properties, specifically shear-wave velocity data, are consistent with the soil type and density The distinctive velocity profile in the top 525 ft is common to the 3 adjacent sites (CGS, WNP-1 and WNP-4) Similar Vs measurements were obtained using different methods with different instruments (cross-hole & down-hole) Seismic refraction measurements agreed well with cross-hole measurements in the top 105 ft at CGS Given the relatively small amount of variation among the measured results, there is a high degree of confidence that any additional measurements would fall close to the base case Vs profile (i.e., low epistemic uncertainty) The variation in soil velocity is adequately covered by consideration of the aleatory uncertainty Site response, Focus Area 1 d Provide additional detail regarding the adequacy of EPRI and Peninsular curves for covering range of nonlinear behavior for the Pasco Gravel. As recommended by the SPID, the EPRI and Peninsular Range curves were used These two sets of nonlinear curves are considered to span the range of nonlinearity for cohesionless soils More recent RCTS data (from other sites) often confirm the adequacy of generic curves for sands and gravels The generic curves were considered appropriate for screening analyses Basalt Flows Profile Provided by PSHA study Velocities measured with PS 0 0 logging and Downhole (DH) ..... : 1 --_,,, methods Two alternative profiles 100 --* r : Weighted 2:1 (DH:PS) -§. ---I r; -Q. --Nonlinear curves for interbeds 0 computed with Darendeli (01) 200 200 ' --. I (D < 15°/o) *--** ** 1 **** , ... F'. ' Site attenuation (Ko) calibrated 300 300 -Site C (profile 1) by recordings -----Site C iproflle 21 0 1000 2000 300C 4000 18 2 22 2.: 26 2.8 3 Vs (mis) p (g'cm') Site response, Focus Area 1 b Provide additional detail regarding the bases for two Vs profiles and their associated weights for the SMB stack. For interbeds, DH and PS Vs values in agreement For basalts Vs from PS .... 25°/o higher than Vs from DH Two Vs profiles created to capture epistemic uncertainty in basalt Vs Vs based on DH favored 2:1 over Vs based on PS DH Vs measured a frequencies near those of interest while PS Vs measured at 1 kHz Experts suggested that reliable PS values in stiff basalts may require use of 5-1 O kHz frequencies Site response, Focus Area 1c (1of2) Provide additional detail regarding the thickness of the interbed deposits including their lateral extent. Based on numerous deep borings, thickness and extent of Ellensburg Formation interbeds mapped across Hanford site Example for Mabton interbed from Rohay and Reidel (2005) MA8TONINTEA8ED * -1 *.: Tl: Site response, Focus Area 1 c (2 of 2) Provide additional detail regarding the thickness of the interbed deposits including their lateral extent Deep wells used to develop SMB stratigraphy at Site C (CGS). Details are in Last (2014) Uncertainty/variability in thickness was included in randomization of layer thicknesses 0 Used for superbasalt sediments and upper Saddle Mountains

• Used for lower Saddle Mountains Dashed where used indirectly 699-13-28' -. (B-35) ** *r " ---* \ . \ . \ ' \ \ " ' ". ' . \ .... . ' 699-15-El J, (DB-2) 01 l. * . . . \ . : ,699-.f2-:1A I ' . I * 'i J I C ' *** ' . *.. . -. .: . (B-36) . -.... I i
• I ' I I ; i / .. .' , . / ( I
• f * / i I "" /' *' / .. . / . . *. /*1'99-2-&14 . ;/ /,/ . .. / l '* .. Based on flow thicknesses from 699*15-15G (DC-8) taken from Landon et al. 1985.

Site response, Focus Area 1 e Provide additional detail regarding the bases for randomizing the small strain damping for the basalt layers in the SMB stack in view of the uncertainty already incorporated into the determination of the site kappa. Randomization is used to address Uncertainty in properties due to measurement error and extrapolation from other locations To characterize spatial variability within the facility footprint. To compensate for simplifications used in conventional 1-D site response analysis methodology Randomization would be applied in SPID methodology even if median properties were known with a high degree of certainty Site response, Focus Area 2 In view of the relatively high shear wave velocities (> 760 mis) and high confining stresses in the interbed layers, provide the rationale for not considering linear behavior of these materials and instead using a single sand curve which demonstrates significant non-linear behavior. lnterbeds are relatively soft rock-like materials even at depth Vs< 1000 mis Some degree of non-linearity expected in such materials at high loading levels, especially because of the large velocity contrasts with the basalts and resulting strain concentrations. Selected the Darendeli (2001) model because it provided a means of incorporating the effect of depth of the interbeds on the G/Gmax and damping relationships. Used only one set of curves with randomization because differences in average response between using alternative sets of median relationships expected to be much smaller that overall uncertainty in defining site ground motions developed for the GMC. Simulated Profiles 0 0 Realization Median 200 200 400 400 Cl) 600 <IJ 600 'O 'O <Cl Cl l3 ;; ;; 0 0 Qi Qi a:i 800 a:i 800 J::. J::. c. c. QI QI 0 0 1000 1000 1200. 1400 0 2000 4000 6000 8000 12000 Shear-Wave Velocity I ft/sec) 10 20 JO Realization 40 50 60 1500 3000 4500 ::. 6000 .... 0 <IJ > 7500 "' "' ., .i::. U'l 9000 10500 12000 .' ... Input Motions PSHA study provided CMS motions at: 20 frequencies 27 MAFEs 4 events M, Rand weight of event I vanes Site response computed for each motion [':' ti fl.I c. t/l i 101 CMS 10° c. . 10 / . ' 0 ;f. "' 10 l Frequency [Hz I 1.0 Hz, AEF: l .Oe-04 -UHR!'> -*.1 '>.6, R: 7 krn, Wt: 0.1'.> '.I R 11 km. Wt: 0 39 '.I . l.l, R: 20 krn, Wt. ->./

• 9.0, R: 3.16 km, Wt* 0.21 Site Response Analysis Total of 2, 160 input rock spectra Two velocity profiles: C1 (downhole) C2 (PS logging) Two nonlinear models for the upper zone: EPRI PR Total of 518,400 soil column analyses Site Response Performed with PSHAKE Uses random vibration theory (RVT) Equivalent-linear wave propagation Control point defined at surface Extracted the site amplification values at the controlling frequency of the CMS motion 70 60 50 1 0 00 J 1 *****Ar1tl"*ue:1*: '.1e;in ' c
• t: *:> *::ic * .! l**en* .-:>rof!le c 1-epn :>erioci 0 100 AEF 1 O*JE** Even: 1 Fr*qu<n<y tltz] 1C 10 (Hz) 'lC * * * *
• Arirhmet1c. Mean -Loganrhm1c. Mean 100 1 D Site Amplification 3.0 0.5 0.0 I 10 Cl*EPRI Frequency [Hz] 10*1 10*l 104 -=-.... ... UJ c: <O QJ ::!: 10 b 107 0.8 07 ci E 06* <t Vi QJ £ 0 0.5. c: .2 :ii s: QJ Cl 0.4 'C .... ro 'C c: <O ., VI .., 03* E .r::. ., *;:::: <O 0-0 ...J 0.2 -<O ;Q Cl*EPRI Frequency [Hz) 101 10 J u.. UJ c: <O QJ 10 '* :r lOb 10 7 1 D log Mean Site Amplification := 100 00 Hz 1= Q. 10 -----------------........ __ f 101) 1. I: 33.33 Hzll 1* I* "oo "'I w* 10 I'--------------------------------_. "---*_.:'_-..........____.-..__.J I :::I.__ ---'----I*_-......... 'I 1100011 l ___ ----101 10) Input PSA at J(gJ 10 l lOO Input PSA at f [gJ I :::r ------l:"'"II .___ __ ............... ""'I llOOv1* 1 -.._, I* "'"ii f _ ___..___I* . .........___,! oo Hzl : -I . ----l*-""'ll .....___ _1'"'""1 :-l'"'"II I* O!Ht,11 1 _________ OIOHll --I JO 1 10<* 101 I "'.I 10 10) I 10 l 10' 101 10" PSA at J [ g] Input PSA at J [gl GMRS-Approach 3 Approach 3 (Bazzurro and Cornell, 2004): Gz(z) = I Gv1x (: lxj) Px(Xj) all Xj Gz(z) = Horizon specific hazard curve Px(xj) = probability of rock input level (i.e., slope of input hazard curve) (z ) ln[mv1x(x)] Gy1x -lxj = <p X (J'lnYIX where fP = 1 -<p is the complementary standard Gaussian CDF my1x(x) = mean amplification factor (Jznvix = sigma of amplification factor GMRS-Approach 3 Input Hazard Curves from PSHA Input Site Amplification Results Two Profiles: Profile C1 (0.67) Profile C2 (0.33) Two Material Curves: EPRI (0.5) Peninsular Range (0.5) No Minimum Amplification Factor Hazard Curves: PGA Approach 3 Results: CGS, Mean (No Min), 100 Hz 1.0E-02 ....... l.OE-03 1.0E-01\ 1.0E-05 <1.'. 1.0E-06 --Input HC ------Cl-EPR I *******Cl-Pen 1.0E-07 C2-EPRI -----C2-Pen --Average HC 1.0E-08 0.01 0.1 1 PGA (g) 10 UHRS: Mean, AEP=1 o-4 10 1 0.1 0.01 *
• 0.1 * * . * . * . . ** * . * * * . . ** * .
• UHRS: CGS, Mean (No Min), AEP=l0-4 . . . . * . * . * . .
• 1 . * ** * *** **** .. ** ** ** Frequency (Hz) **************** *** * ** *****Hard Rock (10-'1) -Approach 3 (10-11) 10 ***** 100 UHRS: Mean, AEP=1 o-s 10 1 0.1 0.01 UHRS: CGS, Mean (No Min), AEP=l0-5 , ..... , ' , ************************** ,-' .. .. , .. r .** ' , .. ** ' , .** ,, ,,, . .... .** ............... , .* ........ . * ....... ,' .. ** ---' .* I *** I ** , .** , .* , .* , .** , .* , .. * , .* , .. , .. ,_ .. ** *****Hard Rock (10-5) --*Appro,Kh 3 (10-5) 0.1 1 10 100 Frequency (Hz)

Surface UHS and GMRS 3 -2 c 0 r:J ... ..., v (,/ Q. V"l 1 0 .l 0 0.1 ,1 , -, , , 4' I\ I \ I \ I ' I ' ' ' ' ' ' ' I t ' ' . -* ' ," ' I ' I I I \ I \ I \ I \ ' \ ' , ' , , ' . . ' -I ', / . 1 10 100 Frequency (Hz) Site response, Focus Area 3 Provide additional detail regarding the decision not to implement a minimum site amplification value and the effect of this decision on the development of the uncertainty in the site amplification function as well as on the final hazard curves for the site. The 0.5 limit is not used in the calculation of the surface hazard because the intended purpose of this report is to obtain the realistic and unbiased median based site amplification for SRA The basis for limitation of 0.50 is not well documented and is more relevant for additional conservatism under design applications

Interim Actions -FLEX strategy Columbia has significant flexibility for connection of portable electrical supplies following a seismic event Two portable 480 V AC diesel generators on-site Two redundant 480 VAC connection points to two safety divisions One additional 480 VAC connection point to either of two safety divisions 4160 VAC diesel generators available through SAFER Two 4160 VAC connection points to two safety divisions One additional 4160 VAC connection point capable of supplying either safety division Installed breakers and cabling allow safety divisions to be cross-tied if needed Interim Actions -FLEX strategy Columbia has significant flexibility for connection of portable pumps to supply cooling water to the core and suppression pool Two portable diesel powered pumps (high head) available onsite Injection points available on all three divisions of Residual Heat Removal (RHR) High capacity pump available through SAFER Injection point available on the Condensate system Connection points on the both divisions of Standby Service Water (SW) with piping cross-connected to RHR Inventory source is the normal plant ultimate heat sink (two SW spray ponds) Interim Evaluation -Seismic Current Seismic Probabilistic Risk Assessment (SPRA) -Mean Seismic Core Damage Frequency is calculated to be 4.9 x1 o-6 Based upon a hazard curve developed in terms of peak ground acceleration (PGA) and fragilities in terms of PGA Current SPRA maintained in alignment with the RG 1.200-compliant Internal Events modeling and is significantly advanced beyond IPEEE requirements Reanalysis of Mean Seismic Core Damage Frequency at PGA using new ground motion response spectrum indicates margin remains Seismic walk downs completed satisfactory as required by Enclosure 3 of the NRC's CFR 50.54(f) Request for Information All results satisfactory Path Forward Energy Northwest is initiating the Expedited Seismic Evaluation Process Report due Jan 2016 Energy Northwest is initiating SPRA in accordance with SPID requirements Submittal due Jun 2017 OENERGY NORTHWEST March 12, 2015 G02-15-045 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk 11555 Rockville Pike Rockville, MD 20852 David A. Swank Columbia Generating Station P .0. Box 968, PE04 Richland, WA 99352-0968 Ph.509-377-2309 I F.509-377-2354 daswank@energy-northwest.com

Reference:

1 O CFR 50.54(f)

Subject:

COLUMBIA GENERATING STATION, DOCKET NO. 50-397 SEISMIC HAZARD AND SCREENING REPORT, RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO 10 CFR 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE REVIEW OF INSIGHTS FROM THE FUKUSHIMA DAl-ICHI ACCIDENT

References:

1) NRG Letter, Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Recommendations 2.1, 2.3, and 9.3, of the Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accident, dated March 12, 2012, ADAMS Accession Nos. ML 12056A046 (Pkg.), ML 12053A340 (Ur.) 2) EPRI Report 1025287, Seismic Evaluation Guidance, Screening, Prioritization and Implementation Details (SPID} for the Resolution of Fukushima Near-Term Task Force Recommendation 2.1: Seismic, ADAMS Accession No. ML 12333A 170 3) NRG Letter, Endorsement of EPRI Final Draft Report 1025287, "Seismic Evaluation Guidance," dated February 15, 2013, ADAMS Accession No. ML12319A074

Dear Sir or Madam:

On March 12, 2012, the Nuclear Regulatory Commission (N RC) issued Reference 1 to all power reactor licensees and holders of construction permits in active or deferred status. Enclosure 1 of Reference 1 requested that each addressee located in the Western United States (WUS) submit a Seismic Hazard Evaluation and Screening Report within 3 years from the date of Reference 1. Reference 2 contains industry guidance and detailed information to be included in the Seismic Hazard Evaluation and Screening Report submittals. NRC endorsed this industry guidance in Reference 3. SEISMIC HAZARD AND SCREENING REPORT1 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO 10 CFR 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE REVIEW OF INSIGHTS FROM THE FUKUSHIMA DAIRICHI ACCIDENT Page 2 of 2 Enclosed is the Seismic Hazard and Screening Report for the Columbia Generating Station. This report provides the information requested in Reference 1, Enclosure 1 and its Attachment 1. The Hanford Sitewide Probabilistic Seismic Hazard Analysis referenced in the report, is available on the Department of Energy's Hanford external website. The direct link is: http://www. hanford .gov/page .cfm/Official Docume nts/HSPSHA. No new commitments are identified in this letter. If you have any questions or require additional information, please contact Ms. L. L. Williams at (509) 377-8148. I declare under penalty of perjury that the foregoing is true and correct. '* 1 ft I Executed on the id_ day of lvf /'c tj , 2015 Respectfully, , D. A. Swank Assistant Vice President, Engineering

Enclosure:

As stated cc: NRC Region IV Administrator NRC NRA Project Manager NRC Senior Resident lnspector/988C MA Jones -BPA/1399 (email) RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Enclosure COLUMBIA GENERATING STATION, DOCKET NO. 50*397 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR* TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION This report provides information in response to NRC's March 12, 2012, 10 CFR 50.54(f) letter requesting nuclear power plant licensees to perform seismic hazard reevaluation and screening for risk evaluation pursuant to the recommendations in NRC's Near-Term Task Force review of the accident at the Fukushima Dai-ichi nuclear facility. 1 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 1.0 Introduction Following the accident at the Fukushima Daiichi nuclear power plant resulting from the March 11, 2011, Great Tohoku Earthquake and subsequent tsunami, the NRC Commission established a Near Term Task Force (NTTF) to conduct a systematic review of NRC processes and regulations and to determine if the agency should make additional improvements to its regulatory system. The NTTF developed a set of recommendations intended to clarify and strengthen the regulatory framework for protection against natural phenomena. Subsequently, the NRG issued a 50.54(f) letter that requests information to assure that these recommendations are addressed by all U.S. nuclear power plants. The 50.54(f) letter requests that licensees and holders of construction permits under 10 CFR Part 50 reevaluate the seismic hazards at their sites against present-day NRG requirements. Depending on the comparison between the reevaluated seismic hazard and the current design basis, the result is either no further risk evaluation or the performance of a seismic risk assessment. Risk assessment approaches acceptable to the staff include a seismic probabilistic risk assessment (SPRA), or a seismic margin assessment (SMA). Based upon the risk assessment results, the NRG staff will determine whether additional regulatory actions are necessary. This report provides the information requested in items (1) through (7) of the "Requested Information" section and Attachment 1 of the 50.54(f) letter pertaining to NTTF Recommendation 2.1 for the Energy Northwest Columbia Generating Station {CGS), located in Benton County in the State of Washington. In earlier licensing documentation, the CGS plant was referred to as Washington Public Power Supply System Nuclear Project Number 2 (WNP-2). In providing this information, Energy Northwest (EN) followed the guidance provided in the Seismic Evaluation Guidance: Screening, Prioritization, and Implementation Details (SPID) for the Resolution of Fukushima Near-Term Task Force Recommendation 2.1: Seismic (EPRI, 2013a). The Augmented Approach, Seismic Evaluation Guidance: Augmented Approach for the Resolution of Fukushima Near-Term Task Force Recommendation 2.1: Seismic {EPRI, 2013b), has been developed as the process for evaluating critical plant equipment as an interim action to demonstrate additional plant safety margin, prior to performing the complete plant seismic risk evaluations. The original geologic and seismic siting investigations for CGS were performed in accordance with Appendix A to 1 O CFR Part 100 and meet General Design Criterion 2 in Appendix A to 1 O CFR Part 50. The Safe Shutdown Earthquake {SSE) ground motion was developed in accordance with Appendix A to 10 CFR Part 100 and used for the design of Seismic Category I systems, structures and components. In response to the 50.54(1) letter and following the guidance provided in the SPID (EPRI, 2013a) with due consideration to the extensive site soil profile data available for the plant site, a seismic 2 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure hazard reevaluation was performed. For screening purposes, a Ground Motion Response Spectrum (GMRS) was developed. Based on the results of the screening evaluation, CGS screens in for a risk evaluation, a Spent Fuel Pool evaluation, and a High Frequency evaluation as part of the risk evaluation. 3 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 2.0 Seismic Hazard Reevaluation CGS is located on the eastern side of the Hanford Site. As discussed in PNNL (2014), the Hanford Site is located east of the region tectonically dominated by the Cascadia subduction zone (CSZ), where the Juan de Fuca (JDF) plate under-thrusts northern California and western Oregon and Washington along the Cascadia subduction zone. Magmatism related to the subduction zone is represented by the Cascade volcanoes, which lie to the west of the Hanford Site. Following establishment of the Cascadia subduction zone and related volcanic chain, the later geologic history of eastern Washington was dominated by eruption and deposition of the Columbia River Basalts (CRBs). The CRB flows in eastern Washington are deformed in a series of generally east-west-trending anticlines underlain by reverse faults that are known collectively as the Yakima Fold Belt (YFB). The reverse faults of the YFB dominate the post-CRB tectonics and topography in eastern Washington. The Yakima folds are anticlines that have accommodated approximately north-south shortening. Seismicity and geodetic indicators of contemporary tectonics confirm that north-south stresses continue to be the dominant stress mechanism. However, the rates of shortening, uplift, and fault slip, as recorded by the deformation of various units of the CAB, show that rates of deformation are low relative to the slip rates of f au Its within active tectonic regions. The Hanford Site is characterized by a relatively thin layer of supra-basalt sediments (mainly the Hanford and Ringold formations), which have thicknesses ranging from 200 to 660 ft (60 to 200 m) at five sites across the Hanford Site investigated by PNNL (2014). These sediments are underlain by the basalt flows of the Saddle Mountain Basalts (SMB) sequence and interbedded Ellensburg formation sediments; the basalt-interbed stacks have a thickness of about 820 ft (250 m) at the PNNL sites. Below the SMB are the Wanapum Basalts and Grande Ronde Basalts, collectively forming the CRB, with a total thickness of 1.2 to 1.9 mi (2 to 3 km) at the PNNL sites. The CAB is underlain by a thick layer of pre-Miocene sediments, with the crystalline basement encountered at depths ranging from 4.7 to 5.6 mi (7.5 to 9 km) at the five PNNL sites. Regional seismicity in the YFB region is dominated by small-magnitude earthquakes that occur within the CRB units in the upper 1.9 mi (3 km), and more diffuse seismicity that extends to depths of about 12.4 mi (20 km). Rates of moderate-to-large earthquakes are low relative to plate boundary regions. Within the YFB region, the largest observed earthquakes are the 1936 Milton-Freewater earthquake (M 6) and the 1872 Lake Chelan earthquake (M 6.5-7). To the west of the site region, earthquakes are mainly associated with the Cascadia subduction zone and Holocene crustal faults in the Puget Lowland. The following section discusses the regional and local geology (Section 2.1 ), the probabilistic seismic hazard analysis (Section 2.2), the development of site profiles and site response analyses (Section 2.3), and the control point response spectrum {Section 2.4). 4 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 2. 1 Regional and Local Geology The CGS site lies in the Pasco Basin which encompasses about 1,600 square miles in south central Washington State. It is one of several physiographic depressions occupying the Columbia Plateau, a major physiographic and geologic province that is surrounded by the Blue Mountains, High Lava Plains and Snake River Plains provinces on the south, the Northern Rocky Mountains and Idaho Batholith provinces on the east, the Okanogan Highlands province to the north, and the Cascade Mountains, Puget-Willamette Trough, and Washington-Oregon Coast Ranges on the west. Bedrock in the Columbia Plateau consists of a thick sequence of Miocene Basalt flows with minor amounts of interflow sediments, known as interbeds. These rocks, generally mantled by younger sediments of Pliocene and Holocene age, are termed the Columbia River Basalts (CRBs). The CRBs cover about 77,000 square miles in Washington, Oregon and western Idaho. The CRBs consist of the Yakima Basalt Sub-Group (which includes the Saddle Mountains Basalt, Wanapum Basalt and Grande Ronde Basalt) and the lmnaha Basalt. Estimated extrusion period of the CRB is between 6 million and 17 million years ago. The CRBs, particularly in the western part of the Columbia Plateau, have been folded into a series of east-west anticlines. The Pasco Basin is a gently undulating, semiarid plain, interrupted by low-lying hills and dunes that are dissected by intermittent streams. The basin is transected by the Columbia River. The CGS reactor is located just over 3 miles west of the Columbia River on the eastern edge of the Hanford Site. The CGS site, which covers about 1, 100 acres, is essentially flat -average surface elevation prior to construction was 440 ft, with a variation of about 4 ft across the site. Plant grade is El. 441 ft. Depth to the groundwater table is about 62 ft. The CGS site is immediately underlain by about 45 ft thickness of Pasco Gravel, a Quaternary deposit made up of glaciofluvial sediments. It is noted that at and around the control point the Pasco gravel was removed and replaced with compacted structural backfill. The Pasco Gravel and structural fill are underlain by the Pliocene-age Ringold Formation, consisting of the Middle Member down to 250 ft depth and the Lower Member down to 525 ft depth. The Ringold is predominantly a sandy gravel with interbedded sandy and silty layers (Middle Member) and some interbedded soft sandstone and some conglomerate present at the base of the layer (Lower Member). Several hundred ft of the Ringold Formation materials at the site were removed during Pleistocene floods. The overlying Pasco Gravel was deposited over the eroded surface of the Ringold Formation materials. The Pasco Gravel at the site has not been subjected to significant past loading. At the CGS site, the top of the CRB occurs immediately below the Ringold Formation, at 525 ft depth. The Saddle Mountains Basalt forms the upper approximately 765 ft of the CRB at the site, ranging from about 10.5 million years old at the top (Elephant Mountain Member) to 13.5 million 5 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure years old (Umatilla Member) at the base. There are four basalt members within the Saddle Mountains Basalt that range from about 110 ft to 215 ft in thickness, each underlain by a sedimentary interbed consisting mainly of sandstone and claystone, and ranging in thickness from about 15 ft to 70 ft. The interbeds have significantly lower strength and density than the basalt. The Saddle Mountains Basalt comprises less than 1% of the volume of the CRB, but perhaps because of their relatively long period of extrusion at a time of waning volcanism, members of the Saddle Mountains Basalt display the greatest petrographic, chemical and paleomagnetic variability of any formation of the CRB. All stratigraphic units beneath the site appear to be nearly horizontal. The Wanapum Basalt beneath the Saddle Mountains Basalt is approximately 1,000 ft thick and is between about 13.5 and 14 million years old. It consists of the Priest Rapids Member, the Roza Member, the Frenchman Springs Member, and the Eckler Mountain Member. The Priest Rapids Member contains the Lolo Flow (about 155 ft thick) underlain by the Rosalia Flow (60 ft thick). The Grande Ronde Basalt below the Wanapum Basalt is approximately 7,200 ft thick. 2.2 Probabilistic Seismic Hazard Analysis Section 2.2 summarizes the results of a probabilistic seismic hazard analysis (PSHA) of the CGS located within the boundaries of the Hanford Site in south central Washington State The PSHA was performed by the Pacific Northwest National Laboratory (PNNL) in accordance with the provisions of the Nuclear Regulatory Commission (NRC, 2014a) 50.54(1) letter and in fulfillment of the requirement from the U.S. Nuclear Regulatory Commission that Energy Northwest conduct a PSHA using Senior Seismic Hazard Analysis Committee (SSHAC) Level 3 procedures (see Appendix 2.2A}. The PNNL report (2014) provides a detailed characterization of the vibratory hard-rock motion hazard at the CGS location from potential future earthquakes conducted using the Level 3 procedures advanced by SSHAC in detailed guidance published by the U.S. Nuclear Regulatory Commission (see Appendix 2.2A for a description of the SSHAC Level 3 process as used for this PSHA). In accordance with this guidance, a participatory peer review panel (PPRP) oversaw all details of the performance of the PSHA and confirmed that the work was done in conformance with SSHAC guidance. This confirmation is provided in a PPRP closure letter (see Appendix 2.2B). 2.2. 1 Probabilistic Seismic Hazard Analysis Results PNNL (2014) report is the source of the information presented in the following section. 6 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure The summary presented here is of the base case rock hazard at the CGS using the seismic source characterization (SSC) and ground motion characterization {GMC) models of the PNNL (2014) report, Chapters 8.0 and 9.0, respectively. A cumulative absolute velocity filter was not applied in this analysis and no site amplification factors are used. Results are consistent with hard-rock conditions {for this site rock with a shear-wave velocity, V5, very close to 9,800 ft/s or 3,000 mis). The methodology for seismic hazard analysis is well established in the technical literatures (e.g., McGuire, 2004). Three sets of seismic sources are included in the SSC model and are identified below: Subduction source zones (discussed in Section 8.2 of the PNNL report) Crustal area source zones {discussed in Section 8.3 of the PNNL report) Crustal fault sources (discussed in Section 8.4 of the PNNL report) The list of all seismic sources and acronyms used in this analysis are provided in Table 2.2.2-3. This list of sources represents a hazard-informed compilation of all sources that would be expected to contribute significantly to the site hazard, based on the hazard sensitivity analyses. The identification and characterization of seismic sources for the SSC model gave highest priority to aspects of the model that had the highest potential hazard significance, and the level of complexity of the SSC model was consistent with current knowledge and importance to hazard. Sensitivity analyses conducted early in the Hanford PSHA project showed that the plate interface seismic source of the CSZ could contribute to long-period ground motions at mean annual frequencies of exceedance {MAFE) of interest to the Hanford Site. For completeness, both the plate interface zone (CSZ) and the intraslab source (JDF) are included in the SSC model. The seismic area source zones defined for the SSC model are shown in Figure 8.1 of the PNNL (2014) report, together with the earthquake epicenters from the project catalog. All seismic area source zones are assessed to be seismogenic with a probability of unity. Two types of seismic area source zones are identified: 1) the YFTB source zone is a "background" zone to the fault sources of the Yakima Fold and Thrust Belt and 2) Zones B, C, and Dare crustal area source zones that do not include identified fault sources. The exceptions are the Arlington (AF), Luna Butte (LB), Laurel {LF), and Maupin (MF) faults that exist within the YFTB background source zone and extend into adjacent Zone D. However, additional faults within Zone D have not been identified separately as fault sources. The reason for the two types of source zones is the relative contribution that nearby sources make to the hazard at the site. Because of their distance from the site, individual faults within Zones B, C, and D are not specifically identified and characterized. Rather, the faults that exist within these source zones are modeled by 7 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure "virtual faults" whose locations are random within each zone and whose characteristics are assessed in the SSC model. The twenty faults whose closest approach lies within about 12.4 mi (20 km) of the site and that were assessed to have a seismogenic probability greater than zero are included in the SSC model (Figure 8.2 of the PNNL (2014) report). In addition, the Seattle fault zone (SFZ) is included in the model for completeness. Sensitivity analyses show that it does not contribute significantly to the hazard at the site because of its distance from the site, but it is included in the model as being representative of faults that exist within the Puget Sound region. With the exception of four faults within the YFTB background source all faults were assessed, like the seismic areas sources, to have a seismogenic probability of unity. Fault trees capturing variation of a number of parameters selected to capture the epistemic uncertainty in the characterization of the three sets of seismic sources are outlined as Figures 8.3 through 8.7 of the PNNL (2014) report. All elements of the SSC model are included in the hazard input document (HID) provided in Appendix D of the PNNL (2014) report. The ground motion characterization (GMC) model consists essentially of two logic trees, one for ground motions from crustal earthquakes (both area and fault) and the other for motions caused by subduction earthquakes (both intraslab and interface), taking into account magnitude and distance ranges appropriate for each group and, for the shallow crustal fault sources, appropriate fault rupture characteristics. In both the shallow crustal and subduction source cases, GMC models represent spectral acceleration at 5% of critical damping and apply to the base rock elevation at the top of the Wanapum Basalts, which have a shear-wave velocity (Vs) very close to 9,840 ft/s (3,000 mis). For both the crustal and subduction logic trees, there are branches for the median motions and also for the associated aleatory variability (sigma). The GMC model is defined by suites of equations with coefficients at twenty spectral frequencies ranging from O. 1 Hz to 100 Hz, which were selected in agreement with the project sponsors and which include the seven spectral frequencies {100 Hz, 25 Hz, 10 Hz, 5 Hz, 2.5 Hz. 1 Hz, and 0.5 Hz) specified in the NRC's 50.54(f) letter (NRC, 2012a). All of the information in the GMC logic tree is presented in the HID, which is included as Appendix D of the PPNL (2014) report. 2.2.2 Base Rock Seismic Hazard Curves Mean seismic hazard curves at CGS are calculated for base rock site conditions (Site C: PNNL, 2014). 8 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure The procedure to develop probabilistic seismic hazard curves for base rock follows standard techniques documented in the technical literatures (e.g., McGuire, 2004). Separate seismic hazard calculations are conducted for twenty spectral frequencies (or periods) ranging from 0.1 Hz (10 seconds) to PGA or 100 Hz (0.01 seconds), as available in supplemental digital material of Appendix J of PNNL (2014). Presented in this report are the results for seven spectral frequencies: PGA (100 Hz), 25 Hz, 10 Hz, 5 Hz, 2.5 Hz, 1 Hz, and 0.5 Hz. The SSC and GMC models discussed in Section 2.2.1 are used for the calculation of the mean base rock hazard. All spectral accelerations presented herein correspond to 5% of critical damping (PNNL, 2014). Figure 2.2.2-1 shows the mean base rock hazard curves for the seven spectral frequencies. Table 2.2.2-1 lists the mean rock uniform hazard response spectra (UHAS) for MAFEs of 10*4, 10-5, and 1 o*6 for twenty spectral periods. The digital values for the mean and fractile hazard curves are provided in Tables 2.2.2-2a through 2.2.2-2g. Deaggregations of the total mean seismic hazard for 10 Hz (0.1 s) and 1 Hz (1.0 s) spectral accelerations at MAFEs of 10'4 and 10*5 hazard levels are shown in Figure 2.2.2-2. Each figure contains histograms representing the percent contribution to the total mean seismic hazard from different magnitude-distance bins. For 10 Hz spectral acceleration the mean hazard at the two MAFEs is dominated by source zones (small magnitudes at distances of less than 62 mi (100 km)), which, as will be seen, is especially attributable to the YFTB background source. For 1 Hz spectral acceleration the mean hazard at the two MAFEs is clearly being impacted by the distant, very large magnitude Cascadia subduction zone, though the relative contribution is higher at an MAFE of 10-4 than at 10*5 hazard levels. At the lower hazard level of 1 o*5, the 1 Hz mean hazard, while the small-to-moderate magnitude sources at near distances are still dominant (YFTB background source), the Cascadia subduction zone and moderate-to-large earthquakes at distances between 6.2 to 31 mi (1 Oto 50 km), attributable to crustal fault sources. appear near equal contributors to about half of the hazard. Deaggregation is also presented as a function of the contribution of the individual seismic sources. Figures 2.2.2-3 and 2.2.2-4 are plots, 10 Hz and 1 Hz, respectively, of the comparison between the mean hazard curves at CGS (Site C in PNNL, 2014) obtained for each individual source relative to the total mean hazard. Acronyms used in these figures are listed in Table 2.2.2-3. By inspection of these figures, Table 2.2.2-3 also indicates those sources contributing more than 5% toward the total 10 Hz and/or 1 Hz mean hazard of the site for MAFEs between 10'4 and 10'5 hazard levels, the MAFEs of specific interest in the estimation of the ground motion response spectrum (GMRS). presented later in this report. Columbia Generating Station is located within the YFTB background zone that clearly dominates the high frequency seismic hazard at the MAFEs of interest (Figure 2.2.2-3), while both the YFTB background zone and the Cascadia subduction (interface) zone (CSZ) generally 9 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure dominate the low frequency hazard {Figure 2.2.2-4). The Juan de Fuca (JDF) intraslab subduction source contributes little to the total mean hazard. Table 2.2.2-1: Mean Rock UHAS at 5% Damping for MAFEs of 10*4, 10*5, and 10*5 Period [s] 10*4 UH RS [g] 10*0 UHRS [g] 10*0 UHAS [g] 0.01 6.366E-01 1.866E+OO 4.132E+OO 0.02 7.817E-01 2.138E+OO 4.494E+OO 0.03 8.189E-01 2.169E+OO 4.469E+OO 0.04 8.272E-01 2.145E+OO 4.369E+OO 0.05 8.206E-01 2.100E+OO 4.246E+OO 0.075 7.976E-01 2.001E+OO 3.997E+OO 0.1 7.536E-01 1.854E+OO 3.689E+OO 0.15 6.528E-01 1.590E+OO 3.150E+OO 0.2 5.878E-01 1.422E+OO 2.808E+OO 0.3 4.828E-01 1.157E+OO 2.292E+OO 0.4 3.873E-01 9.41 SE-01 1.870E+OO 0.5 3.218E-01 7.797E-01 1.531 E+OO 0.75 2.142E-01 5.154E-01 1.030E+OO 1 1.541E-01 3.643E-01 7.277E-01 1.5 1.032E-01 2.301 E-01 4.430E-01 2 7.755E-02 1.699E-01 3.231 E-01 3 5.289E-02 1.110E-01 2.052E-01 5 3.403E-02 7.136E-02 1.282E-01 7.5 2.237E-02 4.648E-02 8.448E-02 10 1.651 E-02 3.454E-02 6.261 E-02 10 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.2.2-2a: Annual Frequency of Exceedance Mean and Fractile Base Rock Seismic Hazard Curves for PGA at Columbia Generating Station (PNNL, 2014) Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile PGA[g] AFE AFE AFE AFE AFE AFE 0.0001 9.358E-02 6.166E-02 7.079E-02 8.71 OE-02 1.122E-01 1.514E-01 0.0005 8.240E-02 5.370E-02 6.166E-02 7.762E-02 1.000E-01 1.259E-01 0.001 7.063E-02 4.169E-02 5.012E-02 6.761 E-02 8.913E-02 1.096E-01 0.003 4.548E-02 1.995E-02 2.570E-02 3.981 E-02 6.607E-02 8.511 E-02 0.01 2.017E-02 5.623E-03 7.762E-03 1.413E-02 3.548E-02 5.370E-02 0.03 7.029E-03 1.202E-03 1.862E-03 3.890E-03 1.259E-02 2.455E-02 0.05 3.939E-03 5.248E-04 8.511 E-04 1.905E-03 7.079E-03 1.479E-02 0.075 2.406E-03 2.455E-04 4.266E-04 1.047E-03 4.365E-03 9.SSOE-03 0.1 1.667E-03 1.288E-04 2.399E-04 6.607E-04 3.020E-03 6.918E-03 0.2 6.459E-04 1.778E-05 4.266E-05 1.738E-04 1.202E-03 3.020E-03 0.3 3.532E-04 4.074E-06 1.175E-05 6.457E-05 6.607E-04 1.778E-03 0.5 1.544E-04 4.266E-07 1.660E-06 1.413E-05 2.630E-04 8.511 E-04 0.75 7.447E-05 5.012E-08 2.512E-07 3.236E-06 1.072E-04 4.365E-04 1 4.219E-05 8.71 OE-09 5.495E-08 9.772E-07 5.012E-05 2.570E-04 2 8.523E-06 5.495E-11 6.761 E-10 3.090E-08 5.370E-06 4.786E-05 3 2.786E-06 1.445E-12 3.020E-11 2.754E-09 1.023E-06 1.380E-05 5 5.433E-07 7.586E-15 3.467E-13 8.128E-11 8.511 E-08 2.042E-06 7.5 1.212E-07 3.631 E-17 7.079E-15 3.631 E-12 8.511 E-09 3.388E-07 10 3.712E-08 O.OOOE+OO 2.344E-16 3.548E-13 1.349E-09 7.943E-08 20 1.412E-09 O.OOOE+OO O.OOOE+OO 1.31 SE-15 9.120E-12 1.318E-09 11 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.2.2-2b: Annual Frequency of Exceedance Mean and Fractile Base Rock Seismic Hazard Curves for 5% Damped 25 Hz SA at Columbia Generating Station (PNNL, 2014) Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile SA [g] AFE AFE AFE AFE AFE AFE 0.0001 9.356E-02 6.166E-02 7.079E-02 8.71 OE-02 1.122E-01 1.514E-01 0.0005 8.408E-02 5.370E-02 6.310E-02 7.943E-02 1.023E-01 1.288E-01 0.001 7.406E-02 4.365E-02 5.248E-02 7.079E-02 9.333E-02 1.148E-01 0.003 5.114E-02 2.138E-02 2.884E-02 4.786E-02 7.244E-02 8.913E-02 0.01 2.483E-02 6.457E-03 9.772E-03 1.995E-02 4.266E-02 5.495E-02 0.03 9.315E-03 1.549E-03 2.512E-03 6.31 OE-03 1.778E-02 2.455E-02 0.05 5.41 OE-03 7.079E-04 1.230E-03 3.388E-03 1.047E-02 1.514E-02 0.075 3.414E-03 3.467E-04 6.607E-04 2.042E-03 6.761 E-03 1.000E-02 0.1 2.426E-03 1.950E-04 4.074E-04 1.380E-03 4.898E-03 7.413E-03 0.2 1.002E-03 3.311 E-05 9.333E-05 4.786E-04 2.138E-03 3.388E-03 0.3 5.670E-04 8.913E-06 3.090E-05 2.188E-04 1.230E-03 2.042E-03 0.5 2.545E-04 1.202E-06 5.623E-06 6.457E-05 5.754E-04 1.023E-03 0.75 1.222E-04 1.778E-07 1.122E-06 2.042E-05 2.754E-04 5.248E-04 1 6.780E-05 3.802E-08 3.020E-07 7.762E-06 1.514E-04 3.090E-04 2 1.232E-05 4.571E-10 6.918E-09 4.786E-07 2.399E-05 6.310E-05 3 3.682E-06 2.042E-11 4.898E-10 6.607E-08 6.166E-06 1.950E-05 5 6.265E-07 2.692E-13 1.122E-11 3.802E-09 8.128E-07 3.311 E-06 7.5 1.245E-07 6.166E-15 4.467E-13 2.818E-10 1.202E-07 6.166E-07 10 3.526E-08 1.000E-16 4.266E-14 3.890E-11 2.630E-08 1.660E-07 20 1.157E-09 O.OOOE+OO 1.122E-16 3.236E-13 3.71SE-10 4.074E-09 12 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.2.2-2c: Annual Frequency of Exceedance Mean and Fractile Base Rock Seismic Hazard Curves for 5% Damped 10 Hz SA at Columbia Generating Station (PNNL, 2014) Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile SA [g] AFE AFE AFE AFE AFE AFE 0.0001 9.372E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.514E-01 0.0005 8.421 E-02 5.623E-02 6.457E-02 7.943E-02 1.000E-01 1.259E-01 0.001 7.411 E-02 4.786E-02 5.623E-02 7.079E-02 9.120E-02 1.072E-01 0.005 3.855E-02 1.905E-02 2.512E-02 3.715E-02 5.248E-02 6.31 OE-02 0.01 2.391 E-02 1.000E-02 1.413E-02 2.291 E-02 3.388E-02 4.169E-02 0.02 1.318E-02 4.786E-03 6.918E-03 1.202E-02 1.950E-02 2.512E-02 0.05 5.174E-03 1.479E-03 2.344E-03 4.571 E-03 7.943E-03 1.096E-02 0.1 2.346E-03 5.370E-04 9.120E-04 1.995E-03 3.802E-03 5.370E-03 0.2 9.721 E-04 1.445E-04 2.951 E-04 7.762E-04 1.660E-03 2.455E-03 0.3 5.397E-04 5.370E-05 1.288E-04 4.074E-04 9.550E-04 1.445E-03 0.5 2.276E-04 1.148E-05 3.548E-05 1.514E-04 4.266E-04 6.918E-04 0.75 1.011 E-04 2.692E-06 1.000E-05 5.754E-05 1.950E-04 3.388E-04 1 5.253E-05 8.128E-07 3.631 E-06 2.S?OE-05 1.023E-04 1.905E-04 1.5 1.848E-05 1.202E-07 6.918E-07 6.918E-06 3.548E-05 7.413E-05 2 8.032E-06 2.570E-08 1.820E-07 2.399E-06 1.514E-05 3.467E-05 3 2.158E-06 2.239E-09 2.239E-08 4.467E-07 3.71 SE-06 9.772E-06 5 3.225E-07 6.026E-11 9.772E-10 3.631 E-08 4.786E-07 1.549E-06 7.5 5.844E-08 2.239E-12 5.754E-11 3.631 E-09 7.079E-08 2.754E-07 10 1.566E-08 1.778E-13 6.457E-12 5.888E-10 1.585E-08 7.244E-08 20 4.656E-10 2.818E-16 2.344E-14 4.677E-12 2.630E-10 1.778E-09 13 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.2.2-2d: Annual Frequency of Exceedance Mean and Fractile Base Rock Seismic Hazard Curves for 5% Damped 5 Hz SA at Columbia Generating Station (PNNL, 2014) Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile SA [g] AFE AFE AFE AFE AFE AFE 0.0001 9.441 E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.514E-01 0.0005 8.809E-02 5.888E-02 6.761 E-02 8.318E-02 1.047E-01 1.349E-01 0.001 7.878E-02 5.370E-02 6.166E-02 7.586E-02 9.550E-02 1.148E-01 0.005 4.042E-02 2.399E-02 2.951 E-02 3.890E-02 5.129E-02 6.166E-02 0.01 2.427E-02 1.31 SE-02 1.660E-02 2.344E-02 3.236E-02 3.890E-02 0.02 1.290E-02 6.166E-03 8.128E-03 1.230E-02 1.738E-02 2.188E-02 0.05 4.750E-03 1.950E-03 2.692E-03 4.365E-03 6.761 E-03 8.913E-03 0.1 1.986E-03 7.079E-04 1.047E-03 1.778E-03 2.951 E-03 3.981 E-03 0.2 7.420E-04 2.138E-04 3.311 E-04 6.310E-04 1.148E-03 1.622E-03 0.3 3.828E-04 8.511 E-05 1.479E-04 3.162E-04 6.026E-04 9.120E-04 0.5 1.441 E-04 2.138E-05 4.266E-05 1.096E-04 2.399E-04 3.890E-04 0.75 5.762E-05 5.495E-06 1.259E-05 3.890E-05 1.000E-04 1.738E-04 1 2.759E-05 1.820E-06 4.677E-06 1.698E-05 4.898E-05 8.913E-05 1.5 8.565E-06 3.090E-07 9.SSOE-07 4.365E-06 1.514E-05 3.090E-05 2 3.383E-06 7.244E-08 2.630E-07 1.445E-06 5.888E-06 1.288E-05 3 7.889E-07 7.244E-09 3.388E-08 2.570E-07 1.31 SE-06 3.311 E-06 5 9.839E-08 2.291E-10 1.660E-09 1.995E-08 1.445E-07 4.365E-07 7.5 1.554E-08 8.913E-12 1.000E-10 1.905E-09 1.950E-08 6.91 BE-08 10 3.796E-09 6.607E-13 1.072E-11 3.020E-10 4.074E-09 1.660E-08 20 9.133E-11 5.129E-16 2.344E-14 1.950E-12 5.754E-11 3.467E-10 14 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.2.2-2e: Annual Frequency of Exceedance Mean and Fractile Base Rock Seismic Hazard Curves for 5% Damped 2.5 Hz SA at Columbia Generating Station (PNNL, 2014) Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile SA [g] AFE AFE AFE AFE AFE AFE 0.0001 9.452E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.0005 8.962E-02 5.888E-02 6.761 E-02 8.318E-02 1.072E-01 1.380E-01 0.001 8.011 E-02 5.370E-02 6.166E-02 7.586E-02 9.550E-02 1.175E-01 0.005 3.739E-02 2.239E-02 2.754E-02 3.631 E-02 4.786E-02 5.623E-02 0.01 2.075E-02 1.175E-02 1.445E-02 1.995E-02 2.692E-02 3.311 E-02 0.02 1.015E-02 5.129E-03 6.607E-03 9.550E-03 1.349E-02 1.698E-02 0.05 3.348E-03 1.380E-03 1.905E-03 3.090E-03 4.786E-03 6.31 OE-03 0.1 1.247E-03 4.571 E-04 6.457E-04 1.096E-03 1.820E-03 2.512E-03 0.2 3.91 SE-04 1.175E-04 1.820E-04 3.311 E-04 6.026E-04 8.511 E-04 0.3 1.778E-04 4.365E-05 7.244E-05 1.445E-04 2.818E-04 4.169E-04 0.5 5.624E-05 9.333E-06 1.738E-05 4.169E-05 9.333E-05 1.514E-04 0.75 1.946E-05 2.089E-06 4.571 E-06 1.288E-05 3.311 E-05 5.888E-05 1 8.381 E-06 6.31 OE-07 1.514E-06 5.012E-06 1.445E-05 2.754E-05 1.5 2.225E-06 8.913E-08 2.570E-07 1.096E-06 3.802E-06 8.128E-06 2 7.827E-07 1.820E-08 6.310E-08 3.236E-07 1.31 SE-06 3.020E-06 3 1.545E-07 1.445E-09 6.607E-09 4.677E-08 2.455E-07 6.457E-07 5 1.561 E-08 3.236E-11 2.344E-10 2.818E-09 2.188E-08 6.918E-08 7.5 2.091 E-09 9.120E-13 1.072E-11 2.188E-10 2.455E-09 9.333E-09 10 4.538E-10 5.248E-14 9.333E-13 2.951 E-11 4.467E-10 1.950E-09 20 8.102E-12 1.862E-17 1.023E-15 1.230E-13 4.365E-12 3.020E-11 15 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.2.2-2f: Annual Frequency of Exceedance Mean and Fractile Base Rock Seismic Hazard Curves for 5% Damped 1 Hz SA at Columbia Generating Station (PNNL, 2014) Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile SA [g] AFE AFE AFE AFE AFE AFE 0.00001 9.457E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.00005 9.445E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.0001 9.366E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.514E-01 0.0005 7.614E-02 5.012E-02 5.754E-02 7.244E-02 9.333E-02 1.148E-01 0.001 5.808E-02 3.715E-02 4.365E-02 5.623E-02 7.244E-02 8.71 OE-02 0.003 2.844E-02 1.698E-02 2.042E-02 2.754E-02 3.631 E-02 4.365E-02 0.005 1.809E-02 1.047E-02 1.288E-02 1.738E-02 2.344E-02 2.884E-02 0.01 8.721 E-03 4.571 E-03 5.754E-03 8.318E-03 1.148E-02 1.445E-02 0.02 3.754E-03 1.585E-03 2.138E-03 3.467E-03 5.370E-03 6.918E-03 0.03 2.159E-03 7.943E-04 1.096E-03 1.905E-03 3.236E-03 4.467E-03 0.05 9.827E-04 3.236E-04 4.571 E-04 8.128E-04 1.514E-03 2.188E-03 0.1 2.712E-04 7.586E-05 1.175E-04 2.188E-04 4.169E-04 6.31 OE-04 0.2 5.472E-05 1.072E-05 1.905E-05 4.266E-05 8.913E-05 1.413E-04 0.3 1.823E-05 2.512E-06 5.012E-06 1.288E-05 3.090E-05 5.129E-05 0.5 3.758E-06 2.754E-07 6.761 E-07 2.239E-06 6.457E-06 1.230E-05 0.75 8.990E-07 3.388E-08 1.023E-07 4.365E-07 1.549E-06 3.311 E-06 1 2.938E-07 6.31 OE-09 2.239E-08 1.175E-07 4.898E-07 1.148E-06 2 1.377E-08 4.786E-11 2.884E-10 2.884E-09 1.995E-08 6.026E-08 5 1.672E-10 2.951E-14 4.467E-13 1.202E-11 1.660E-10 7.244E-10 10 7.121E-12 9.120E-17 3.090E-15 2.042E-13 4.898E-12 2.754E-11 16 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.2.2-2g: Annual Frequency of Exceedance Mean and Fractile Base Rock Seismic Hazard Curves for 5% Damped 0.55 Hz SA at Columbia Generating Station (PNNL, 2014) Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile SA [g] AFE AFE AFE AFE AFE AFE 0.00001 9.456E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.00005 9.228E-02 6.026E-02 6.918E-02 8.511 E-02 1.096E-01 1.479E-01 0.0001 8.577E-02 5.623E-02 6.457E-02 8.128E-02 1.023E-01 1.31 SE-01 0.0005 4.813E-02 2.951 E-02 3.548E-02 4.571 E-02 6.026E-02 7.413E-02 0.001 3.171 E-02 1.905E-02 2.291 E-02 3.020E-02 3.981 E-02 4.898E-02 0.003 1.376E-02 8.128E-03 9.772E-03 1.318E-02 1.778E-02 2.138E-02 0.005 8.460E-03 4.677E-03 5.888E-03 8.128E-03 1.096E-02 1.349E-02 0.01 3.935E-03 1.698E-03 2.291 E-03 3.631 E-03 5.623E-03 7.079E-03 0.02 1.569E-03 4.898E-04 6.918E-04 1.288E-03 2.512E-03 3.631 E-03 0.03 8.156E-04 2.188E-04 3.162E-04 6.026E-04 1.318E-03 2.089E-03 0.05 2.997E-04 6.607E-05 1.023E-04 2.089E-04 4.786E-04 8.511 E-04 0.1 5.295E-05 8.128E-06 1.479E-05 3.548E-05 8.318E-05 1.549E-04 0.2 5.984E-06 4.677E-07 1.122E-06 3.548E-06 1.023E-05 1.950E-05 0.3 1.357E-06 5.888E-08 1.698E-07 6.918E-07 2.344E-06 4.898E-06 0.5 1.661 E-07 2.692E-09 1.047E-08 6.026E-08 2.81 BE-07 6.761 E-07 0.75 2.590E-08 1.479E-10 7.762E-10 6.607E-09 3.981 E-08 1.122E-07 1 6.247E-09 1.445E-11 1.000E-10 1.148E-09 8.71 OE-09 2.818E-08 2 1.422E-10 1.995E-14 3.162E-13 9.120E-12 1.349E-10 6.166E-10 5 5.984E-13 5.623E-19 4.898E-17 6.166E-15 2.692E-13 1.995E-12 10 1.125E-14 O.OOOE+OO O.OOOE+OO 2.188E-17 2.512E-15 2.754E-14 17 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.2.2-3: Acronyms for Seismic Sources and Indication of Those Sources Contributing more than 5% of the Total 1and/or10 Hz Seismic Hazard for Mean Annual Frequencies of Exceedance Between 10*4 and 10*5 Acronym Seismic Source Name >5% Contribution* Subduction Sources csz Cascadia Subduction Zone (interface) 2 JDF Juan de Fuca lntraslab source Crustal Area Sources YFTB Yakima Fold and Thrust Belt Backciround 1 Zone B Mid-C Study Zone B ZoneC Mid-C Study Zone C Zone D Zone D Crustal Fault Sources AF Arlington ARH Ahtanum -Rattlesnake Hills 10 CH Columbia Hills CM Cleman Mountain FH Frenchman Hills HHH Horse Heaven Hills 7 HR Horn Rapids Fault 6 LB Luna Butte LF Laurel MF Maupin MR Manastash Ridge RAW Rattles of the Rattlesnake-Wallula Alicinment 8 RM Rattlesnake Mountain 3 SB Selah Butte SFZ Seattle Fault SM Saddle Mountain 9 TR Toppenish Ridge UR Umtanum Ridge 4 WF Wallula Fault YR Yakima Ridoe 5 Note: Modified after Table 10.13 in PNNL (2014) "Number represents approximate order of contribution to the total hazard; lack of a number indicates that the source contributed <5% to the total hazard 18 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 1.E-02 I 1.E-03 I r I I I I I I CD I u I c 1.E-04 "' ""C I I CD I CD I u I 25 Hz )( I LU I 10 Hz 0 I > 1.E-05 u PGA c I I CD I ::::s I -SHz I C" I CD ... I 2.5 Hz LL. -I "' -lHz ::::s 1.E-06 c I c I -0.5 Hz I < I I I I 1.E-07 I I I I I I I 1.E-08 I I L _____________ 0.01 0.1 1 10 100 Spectral Acceleration (g) Figure 2.2.2-1: Mean Base Rock Hazard Curves for Oscillator Frequencies of 0.5, 1, 2.5, 5, 10, 25 and 100 Hz at Columbia Generating Station (PNNL, 2014) at 5% Spectral Damping 19 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Site c (CGS): 10*4 MAFE: T:0.1 sec SA Site c (CGS): 104 MAFE: T:1.0 sec SA 20* (.:") Site C (CGS): 10*5 MAFE: T:0.1 sec SA Site C (CGS): 10*5 MAFE: T:1.0 sec SA . . 10<:, tf) Figure 2.2.2-2: Deaggregation Histogram Showing Magnitude-Distance Contributions to the Total Mean Hazard at Site C for 5% Damped 10 Hz (0.1 s) (left column) and 1 Hz (1.0 s) (right column) Spectral Accelerations at MAFEs of 10*4 (top row) and 10*5 (bottom row) (Source: Figures 10.41and10.42 in PNNL, 2014) 20 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure SiteC 10*1 G) (,) c 10*<' cu 'ti G) G) (,) 10*3 )( w 0 10-4 c G) :I tT G) 10*5 .... u. cu :I 10*6 c c <( 10*7 10*4 10*3 10*2 10*1 100 101 T0.1 sec Spectral Acceleration [g] -meanTOT *-***--* csz .,,.

• JDF ....... &-*** ZONEB ........ & ........ ZONEC *--*& --YFTB ZONED --AF --ARH CH --CM --FH HHH --HR LB --LF MF --MR --RAW RM SB --SFZ --SM --TR UR --YR WF Figure 2.2.2-3. Comparison Between the Mean Hazard Curves at Columbia Generating Station (Site C) Obtained for Each Individual Source: subduction sources are shown by dotted star curves; crustal sources by dotted circle curves; and fault sources by solid curves for 5% damped 10 Hz (0.1 s) SA. Acronyms used in figures are listed in Table 2.2.2-3 (Source: Figure 10.44 in PNNL, 2014) 21 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure SiteC 10-1 a,, (..) c: cu a,, a,, (..) 10-3 >< w '-0 10*4 c: a,, ::::I C"' G,) 10-S ... u. -cu ::::I 10*6 c: c: <( 10-7 10-8 ............... .......... ............... 10-5 10-4 10-3 10-2 10-1 10° T1.0sec Spectral Acceleration [g] -meanTOT ***-***-** csz JDF ....... & ....... Z 0 NEB ......... a ......... ZONEC ...... & ....... YFTB ZONED --AF --ARH CH --CM --FH HHH --HR LB --LF MF --MR --RAW RM SB --SFZ --SM --TR UR --YR WF Figure 2.2.2-4. Comparison Between the Mean Hazard Curves at Columbia Generating Station (Site C) Obtained for Each Individual Source: subduction sources are shown by dotted star curves; crustal sources by dotted circle curves; and fault sources by solid curves for 5% damped 1 Hz (1.0 s) PSA. Acronyms used in figures are listed in Table 2.2.2-3 (Source: Figure 10.44 in PNNL, 2014) 22 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 2.3 Site Response Evaluation Following the guidance contained in Seismic Enclosure 1 of the NRG (2012a) 50.54(f) Request for Information and in the SPID (EPRI, 2013a) for nuclear power plant sites that are not located on hard rock (defined as 9,200 ft/s or 2,830 m/s), a site response analysis was performed for CGS. 2.3.1 Description of Subsurface Material Soils beneath the CGS site extend down to approximately 525 ft depth. The top soil layer consists of about 45 ft thickness of Pasco Gravel, a Quaternary deposit made up of glaciofluvial sediments consisting of loose to medium dense sand with scattered gravel. These soils are underlain by the Pliocene-age Ringold Formation. The Ringold comprises (1) the Middle Member, a very dense sandy gravel with interbedded sandy and silty layers, down to 250 ft depth, and (2) the Lower Member, from 250 ft to 525 ft depth, consisting of very dense interbedded layers of sandy gravel, silt and soft sandstone with some conglomerate present at the base of the layer. Several hundred feet of the Ringold Formation materials at the site were removed during Pleistocene floods. The overlying Pasco Gravel was deposited over the eroded surface of the Ringold Formation materials and has not been subjected to significant past loading. The groundwater table is in the Middle Ringold Member at a depth of about 62 ft. The rock below 525 ft consists of the Saddle Mountains Basalt (SMB) down to about 1300 ft depth, underlain by the Wanapum Basalt, Grande Ronde Basalt, and the lmnaha Basalt. The Wanapum Basalt is counted as the start of basement rock, with a shear wave velocity (Vs) of over 9,200 ft/s. There are four basalt members within the SMB that range from about 110 ft to 215 ft in thickness, each underlain by a sedimentary interbed consisting mainly of sandstone and claystone, and ranging in thickness from about 15 ft to 70 ft. The collective interbeds are called the Ellensburg Formation. The deepest boring at the CGS plant extended to about 850 ft depth, to just below the bottom of the second sedimentary interbed (Selah lnterbed) of the SMB. The stratigraphy below the Selah lnterbed was inferred from four borings not drilled tor CGS but within 2.6 to 3.4 miles of the site. The SMB stratigraphy at CGS (from the 850-ft deep boring at the site and the four borings beyond the site) is compared in Table 2.3.1-1 with the stratigraphy at the Waste Treatment Plant (WTP) about 10 miles northwest of CGS. 23 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.1-1: Comparison of Estimated SMB Layer Thicknesses at CGS and WTP Stratum Thickness (ft) CGS WTP Elephant Mountain Basalt 130(1) 110 Rattlesnake Ridge lnterbed 25(1) 45 Pomona Basalt 160(l) 200 Selah lnterbed 15t1J 20 Esquatzel Basalt 11Q(LJ 90 Cold Creek lnterbed 44(Z) 95 Umatilla Basalt 214(2) 150 Mabton lnterbed 67lLJ 100 (1) From the 850-ft deep CGS site boring (2) From the four borings located 2.6 miles to 3.4 miles from the CGS site Table 2.3.1-1 shows that all of the basalt members and sedimentary interbeds of the SMB present at WTP are also present at the CGS site. The total thicknesses of the SMB at each site are comparable (765 ft at CGS and 810 ft at WTP) although the elevations of the top of the SMB are different (El. -85 ft at CGS and El. 290 ft at WTP). The thicknesses of each basalt member are comparable, with generally more variation in the interbed thicknesses. It is noted that at WTP, the Umatilla Member consists of the upper Sillusi flow and the underlying Umatilla flow. At CGS, the Umatilla Member is assumed to consist only of the Umatilla flow (PNNL, 2014). The 850-ft deep boring at CGS did not include measurements of Vs or other geotechnical parameters. Actual Vs measurements at CGS were taken to 105 ft depth. Vs measurements were taken down to close to the bottom of the Ringold Formation at the nearby WNP-1 (1 mile southeast of the CGS site) and WNP-4 (3/4 mile northeast of the CGS site) sites, and can be used for the CGS site. (The WNP-1 and WNP-4 nuclear plants were started but not completed.) However, no measurements of Vs or other geotechnical parameters were made in the SMB at CGS, WNP-1 or WNP-4. Extensive Vs and unit weight (y) measurements were performed down to about 1,450-ft depth at WTP, i.e., into the Wanapum Basalt basement rock. Given the level of agreement between the SMB stratigraphy at the CGS and WTP, it is reasonable to apply the WTP SMB Vs and y values to the CGS site. Table 2.3.1-2 provides a brief description of the subsurface materials in terms of the geologic units and layer thicknesses. This table includes best estimate values of Vs, compressive wave velocity (Vp), v and Poisson's ratio. As discussed in Section 2.3.2, both down-hole and P-S suspension logging measurements were used to measure Vs at WTP. The Vs values in the SMB in Table 2.3.1-2 are the mean values from the down-hole measurements since they are 24 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure considered to be more representative. The P-S suspension logging Vs measurements are presented and discussed in Section 2.3.2. Table 2.3.1-2: Geologic Profile and Estimated Layer Thicknesses for CGS Depth Soil/Rock Density Vs Vp Poisson's Range Description (pcf) (fVs) (ft/s) Ratio (ft} 0 SSE control point ------------0-6 Pasco Gravel 105 520 1,080 0.35 6-13 Pasco Gravel 105 700 1,460 0.35 13-21 Pasco Gravel 105 840 1,750 0.35 21-45 Pasco Gravel 105 900 1,875 0.35 45-56 Middle Ringold 141 1,320 2,620 0.33 56-85 Middle Ringold 145 2,040 4,805 0.39 85-250 Middle Ringold 145 4,740 10,135 0.36 250-300 Lower Ringold 145 2,300 4,920 0.36 300-325 Lower Ringold 145 3,260 6,970 0.36 325-525 Lower Ringold 145 2,200 4,705 0.36 525-655 Elephant Mountain Basalt 175 7,575 15,950 0.35 (SMB) 655-680 Rattlesnake Ridge lnterbed 118 2,750 7,520 0.42 680-840 Pomona Basalt (SMB) 175 8,300 16, 120 0.32 840-855 Selah lnterbed 133 2,945 7,400 0.41 855-965 Esquatzel Basalt (SMB) 171 8,285 17, 175 0.35 965-1009 Cold Creek lnterbed 121 2,700 6,560 0.40 1009-1223 Umatilla Basalt (SMB) 166 8,360 17,270 0.35 1223-1290 Mabton lnterbed 127 2,720 7,445 0.42 1290+ Basement Rock 176 9,840 20,870 0.36 There are transition zones called flow tops between the interbeds and the SMB basalt members, ranging in thickness from approximately 20 ft above the Elephant Mountain Basalt to 31 ft above the Pomona Basalt. These flow tops consist of breccia, vesicular basalt, or a mixture of sedimentary clay and basalt breccia. Vs increases through these flow tops from the interbed Vs to the basalt Vs. The thickness of the flow tops is included in the depth range for each of the basalt members listed in Table 2.3.1-2. There is also a thin flow top at the top of the underlying Wanapum Basalt. The flow top Vs values (and corresponding flow top densities) are not included in Table 2.3.1-2, but are modeled in the seismic response analysis. As noted earlier in this section, the Wanapum Basalt below the SMB is counted as the start of basement rock, with a shear wave velocity (Vs) of over 9,200 ft/s. The basement rock is modeled 25 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure with an assigned Vs of 9,840 ftls {3,000 m/s) in the seismic response analysis and this is the value shown in Table 2.3.1-2. 2.3.2 Development of Base Case Profiles and Nonlinear Material Properties The approach taken in developing base case profiles and nonlinear material properties for the upper 525 ft of soil materials at CGS is substantially different from that for the underlying basalt members and interbeds. Soil Materials to 525 Ft Depth Available Data There are four sources of data available to create the base-case soil Vs profile: 1. The cross-hole Vs profile from CGS (originally called WNP-2) to a depth of 105 ft. 2. Cross-hole and down-hole Vs results from nearby WNP-1 and WNP-4. 3. Seismic refraction survey interpretation in the upper materials at CGS. 4. Indirect means of determining shear wave variation using SPT N-value data for the shallower deposits. Figure 2.3.2-1 shows Vs plotted versus depth for data sources 1 and 2. These plotted results do not show the actual measured values, but rather averaged results over specified depth intervals. There is generally good agreement between the results in the figure. The Vs measurements in the Middle Member of the Ringold Formation between about 100 ft to 250 ft depth range from around 4,500 ft/s to 5,000 ft/s. These values are considerably higher than would be expected in what is generally regarded as a soil formation. However, there is strong supporting evidence for these higher values:
• The results at CGS increased to around 4,200 ft/s towards the bottom of the boring.
• Similar measurements were obtained at WNP-1 and WNP-4 using both cross-hole and down-hole methods, which are quite different techniques that use entirely different instruments.
• The Vs measurements below 250-ft depth in the Lower Member of the Ringold Formation at WTP-1 and WTP-4 drop back into the expected Vs range of about 2,000 to 2,500 tVs, again suggesting that the equipment was providing accurate measurements. Three shallow seismic refraction survey lines (data source 3) were run at CGS. Vs values were obtained from the Vp measurements using the Poisson's ratio values given in Table 2.3.1-2. The measured cross-hole and derived seismic refraction Vs values down to 105 ft depth were in 26 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure good agreement, including a jump to between 4,350 to 4.490 ft/s from seismic refraction. compared to 4,200 fVs noted above for the same depth interval from the cross-hole. There are numerous relationships developed in the literature to determine Vs using standard penetration test (SPT) N-values. For the CGS site, boring logs were available from 29 borings with SPT N-values taken at 2 .5-ft to 10-ft intervals (data source 4). Refusal ( N = 100 blows/ft) was reached typically at about 45 ft depth, i.e., at the bottom of the Pasco Gravel. Analysis of the standard deviation of these data using the natural log of Vs (i.e., o1nvs) showed that for the Pasco Gravel, the average 01nvs was about 0.25. Vs measurements at WNP-1 extend to about 435 ft depth and at WNP-4 to about 400 ft depth. The bottom of the Ringold Formation is at about 437 ft depth at WNP-1 and at about 406 ft depth at WNP-4. Thus it can be concluded that the Vs measurements at these two sites extend to within a few feet of the bottom of the Ringold. It is reasonable to conclude that the best fitting Vs value of just over 2,000 ft/sin the lower portions of WNP-1 and WNP-4 (Figure 2.3.2-1) extends also to the bottom of the Ringold at CGS at 525 ft depth. Base Case Profiles EPRI (2013a) (SPID), Appendix B-3.2 indicates that for sites with very limited Vs data, the estimate for epistemic uncertainty is to be taken as a1nvs = 0.35. In this situation, there will be three base case Vs profiles, the best estimate or base case (Vee), the lower range (VLR) and the upper range (VuR). Each of these Vs profiles is randomized and a weight given to each. EPRI (2013a) recommends that VLR is the 101h percentile and VuR is the 901h percentile. with V8c being the 501h percentile. According to EPRI (2013a), the 101h and 901h percentiles correspond to a profile scale factor of 1.28 01nvs* This results in VLR = 0.639 Vee and VuR = 1.565 Vee. This is a much greater variation in Vs than obtained from the measured Vs values shown in Figure 2.3.2-1. A more realistic approach is to accept that there is not a great deal of epistemic uncertainty at CGS, given the good agreement between the CGS, WNP-1 and WNP-4 Vs results, and the good agreement using cross-hole, down-hole and seismic refraction techniques., there is no distinct epistemic uncertainty on the shear-wave velocity data. Epistemic uncertainty represents the lack of knowledge about the Vs profile of the CGS site. Given the Vs profile shown in Figure 2.3.2-1, it is probable that an additional measured Vs profile would fall close to the V sc profile derived from the Figure 2.3.2-1 results. Thus, the Vee profile derived from Figure 2.3.2-1 will be used, and the aleatory variability {i.e., the inherent variability found at any site) will be accommodated by assigning standard deviation values to the Vsc profile to be used in the randomization process. The randomization process (Section 2.3.3) typically considers up to 2 standard deviations from the base case. As noted before, since seismic properties are typically considered to be log-normally distributed, 01nvs will be used, i.e., the log normal standard 27 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure deviation. To summarize, a single base case profile (Vsc) will be used, and the variability in the randomization process will be accounted for by using simulated profiles. Table 2.3.2-1 shows the Vsc values computed from the Figure 2.3.2-1 results down to 525 ft depth. Values of 01nvs that are used to obtain Vus and VLs are discussed next. For aleatory variability, EPRI (2013a) Appendix 8-4.1 recommends using 01nvs = 0.25 down to 15 m (49 ft (15 m) depth and a1nvs = 0.15 below that. As noted above, the average 0'1nvs based on correlation with N-value for the top approximately 45 ft is about 0.25, in agreement with the EPRI (2013a) recommendation. The 01nvs = 0.25 is extended down to 56 ft depth, the nearest interval bottom to 49 ft. Between 300 ft and 325 ft depth, (El. 140 ft to El. 115 ft) the WNP-1 Vs is about 2,300 ft/s while the WNP-4 Vs is about 4,300 ft/s, and V8c is 3,260 ft/s. To account for this larger variation, a1nvs will be assigned a value of 0.3 in this range. Below 325 ft depth (El. 115 ft), although there are down-hole data for WNP-1 and WNP-4, these do not extend down to El. -85 ft (bottom of Ringold at CGS). Thus, there is a somewhat higher level of uncertainty in this range, and so 0'1nvs is increased to 0.2. Table 2.3.2-1 shows the recommended Vs with the corresponding 0'1nvs values. The Vee, VLs and Vue profiles, which respectively represent the 1 o*h and 901h percentiles, are plotted in Figure 2.3.2-2. Note that the values from Figure 2.3.2-1 for CGS (WNP-2). WNP-1 and WNP-4 hole CH and down-hole DH) are also included in Figure 2.3.2-2. Rock Below 525 Ft Depth The rock beneath the bottom of the Ringold Formation is described in Section 2.3.1. It consists of the Saddle Mountains Basalt (SMB) down to about 1300 ft depth. underlain by the Wanapum Basalt which is counted as the start of basement rock, with Vs of over 9,200 ft/s. The stratigraphy of the rock at CGS is taken from a deep boring at the site down to about 850 ft depth and from four borings outside but relatively close to the site down to 1,300 ft depth. However, no Vs measurements were made in the rock in any of these five borings. As described in Section 2.3.1, the Vs values for the rock at CGS were obtained from extensive measurements made in the rock at WTP. Both down-hole and P-S suspension logging Vs measurements were made down to about 1,400 ft depth at WTP. terminating in the Rosalia Flow of the Wanapum Basalt. The down-hole measurements (Profile C1) were judged to be more representative since it was determined that the P-S suspension logging measurements (Profile C2) would probably have required higher frequency signals to accurately measure the hard basalt (PNNL, 2014). It was concluded that the down-hole measurements could be considered to be twice as reliable as the P-S suspension logging measurements in this environment, leading to the assignment of relative 28 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure weights of 2:1, i.e., a weight of 2 to Vs Profile C1 and a weight of 1 to Vs Profile C2 (PNNL, 2014). The Vsc values versus depth and elevation for Profile C1 and Profile C2 are given in Table 2.3.2-2. For variation of each Vsc profile, <11nvs of 0.1 is used for each basalt member, and 01nvs of 0.2 is used for each interbed (PNNL, 2014). The Vee. VLe and Vue profiles are plotted on Figure 2.3.2-3 for both the rock and the soil with VL8and Vue representing the 10th and goth percentiles. As noted in Section 2.3.1, there are transition zones called flow tops between the interbeds and the SMB basalt members, ranging in thickness from approximately 20 ft above the Elephant Mountain Basalt to 31 ft above the Pomona Basalt. There is also a thin flow top at the top of the underlying Wanapum Basalt. The flow top Vs values (and corresponding flow top densities) are not included in Table 2.3.2-2 or Figure 2.3.2-3, but are modeled in the seismic response analysis. The flow top Vs values and corresponding flow top densities are shown in Figure 2.3.2-4 (from PNNL.1. 2014). Table 2.3.2-1: Base Case Shear-Wave Velocity (V8c) for the Soil Profile Material Depth {ft) Top El. (ft) Vs (fVs} OtnVs Sand 0-6 440 520 0.25 Sand 6-13 434 700 0.25 Sand 13*21 427 840 0.25 Sand 21*45 419 900 0.25 Middle Ringold 45-56 395 1,320 0.25 Middle Ringold 56-85 384 2,040 0.15 Middle Ringold 85-250 355 4,740 0.15 Lower Ringold 250-300 190 2,300 0.15 Lower Ringold 300-325 140 3,260 0.30 Lower Ringold 325-525 115 2,200 0.20 29 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.2-2: Base Case Shear-Wave Velocity (V8c) Rock Profiles C1 and C2 Material Depth Top El. Vsc C1 Vsc C2 O'tnVs (ft) {ft) {ftls) {ftls) Elephant Mtn Basalt (SMB) 525-655 -85 7,575 9,550 0.1 Rattlesnake Ridge lnterbed 655-680 -215 2,750 2,730 0.2 Pomona Basalt (SMB) 680-840 -240 8,300 10,235 0.1 Selah lnterbed 840-855 -400 2,945 3,190 0.2 Esquatzel Basalt (SMB) 855-965 -415 8,285 9,690 0.1 Cold Creek lnterbed 965-1009 -525 2,700 2,490 0.2 Umatilla Basalt (SMB) 1009-1223 -569 8,360 9,420 0.1 Mabton lnterbed 1223-1290 -783 2,720 2,565 0.2 Basement Rock 1290+ -850 9,840 9,840 -30 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure -£ Q ... c 1000 50 100 150 200 250 300 350 400 Shear Wave Velocity. ft/sec 2000 3000 4000 WNP*2 r I I I WNP-4 I I I I I I WNP-1 I I I I I I I I I l I r-*.....------__....._ __ __, I I I I I I I : WNP-4 L------------, l I I I I I r--L--------I I I WNM 6000 __ _._ _____ ..._ ____ _.. __________________ ..... EXPLANATION ------Downhole menurtment ----Cros1hole meuuremen1 Figure 2.3.2-1: Vs Values in Soil from CGS (WNP-2), WNP-1 and WNP-4 (Source: FSAR Figure 361.017-1; EN, 2013b) 31 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 450 350 250 g i:: 0 i 150 > a> w 50 150 0 I Sand I GS El. 440ft . -* I -I
• I I : : I .l --., I I I ...... :-* . I . I __ J _________________ . '* .
• I .... -----. ! . I . ' . *---. . . . . I I .

. Middle Ringold . . . . . . . . ------. . I I . I . I . . I . I . I I I . : ,*-------------------------. *I . :1 . __ I I . !1 . Lower Ringold . I .. . . I I . I . . ----.. --. . . -----WNP-1 CH . . . . ----*WNP-2CH . . . . WNP-4CH . . . WNP-1 DH . . . . -WNP-4DH . . . -Base Case . . . . * * * *

• Lower Bound . . . ---Upper Bound .

. . . . --. I Saddle Mtn Basalt 1000 2000 3000 4000 5000 6000 7000 Vs (fps) Figure 2.3.2-2: Base Case, Lower Bound and Upper Bound Vs in Top 525 Ft 32 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Developement of Base Case Profiles Shear wave Velocity (fps) 0 2000 4000 6000 8000 10000 12000 14000 0 = -.s CL al 100 200 300 400 500 600 Q 700 800 900 1,000 1,100 1,200 1,300 .. --L .1 I:_ * * . . .. . .. II . -II . . . . I . I . I I . I . I I . I ' . I . I . I . Soil, Ba5e Case Soil, Lower-bound Soil, Upper-bound -Rock Profile 1, Base Case -* -Rock Profile 1, Lower-bound ....... Rock Profile 1, Upper-bound -Rock Profile 2, Base Case -* -Rock Profile 2, Lower-bound ******* Rock Profile 2, Upper-bound I I . I ..... I I I . . ... I : : I .... ..... ' ***. I lo I I ...... Figure 2.3.2-3: Base Case, Lower Bound and Upper Bound Vs for Rock Profiles C1 & C2 33 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 0 100 -E -a. ct> 0 200 . *:,.*:I 300 0 0 L---I I I I 100 --, I I I 200 *,,* 300 I I F,,-.:,.:. *,-: :-* . Sile c (profile 1) Site C (profile 2) .._ l r 1000 2000 Vs (m/s) 3000 4000 1.8 2 2 2 2.4 2.6 2.8 r (g/cmC*) Figure 2.3.2*4: Rock Profiles C1 & C2 Showing Flow Top Shear-Wave Velocities and Densities (PNNL, 2014) 34 of 136 3 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 2.3.2.1 Shear Modulus and Damping Ratio Curves 2.3.2.1.1 Shear Modulus and Damping for Soil Materials to 525 Ft Depth For curves of soil shear modulus reduction (G/GMAx) and damping ratio (D) versus cyclic shear strain, EPRI (2013a) (SPID) recommends using the EPRI and Peninsular curves for cohesionless soils defined by depth, giving an equal weight to each. Since the CGS soils are classified as mainly sand in the upper 45 ft, and the Ringold Formation from 45 ft to 525 ft is mainly sandy gravel, these curves are appropriate. Figure B-8 of EPRI (2013a) shows the EPRI curves, giving curves from 0-20 ft depth all the way down to 500-1,000 ft depth (from EPRI, 1993). This figure is included here as Figure 2.3.2.1-1. The tabulated values scaled from these curves are given in Table 2.3.2.1-1 for G/GMAx and Table 2.3.2.1-2 for D. The Peninsular curves (from Silva et al, 1997) for G/GMAxand D versus shear strain for depth of 0 to 50 ft and depth of 50 to 500 ft are given in Figure 2.3.2.1-2. The tabulated values of the Peninsular curves are given in Table 2.3.2.1-3 for G/GMAx and D. Comparison of the values in Tables 2.3.2.1-1, 2.3.2.1-2 and 2.3.2.1-3 shows that for G/GMAx and D, the Peninsular curve for depth of 0 to 50 ft is very similar to the EPRI curve for depth of 50 to120 ft, and the Peninsular curve for depth of 50 to 500 ft is very similar to the EPRI curve for depth of 500 to 1,000 ft. This similarity is noted in EPRI (2013a). As noted in EPRI (2013a), D values are limited to 15% in the soil column analysis. Table 2.3.2.1-4 shows the applicable curves from Tables 2.3.2.1-1, 2.3.2.1-2 and 2.3.2.1-3 for use in each depth range. The uncertainty of each G/GMAx and D versus shear strain curve is computed following the methodology outlined in EPRI (2013a) and further explained in PNNL (2014). At a shear strain of 0.03%, the variation of G/GMAxand Dis treated as a log normal distribution with the natural log of the standard deviation cr1n = 0.15 for G/GMAX and cr1n = 0.30 for D. For D, cr1n is independent of shear strain. For G/GMAx, cr1n is varied with shear strain to taper the variation at small strains such that the non-linear curves converge to 1 at small strains. 2.3.2.1.2 Shear Modulus and Damping for Rock below 525 Ft Depth The basalt members of the Saddle Mountains Basalt behave as elastic materials with G/GMAx = 1 over the strain range of interest. Damping of the basalt members is independent of strain, and was estimated as a function of the inverse of Vs (PNNL, 2014). Damping values ranged from a high of 1.03% in Profile 1 for the uppermost flow top of the Elephant Mountain Basalt to 0.46% in Profile 2 for the Pomona Basalt, with a median of about 0.75% (Profile 1) and about 0.65% (Profile 2). 35 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Several non-linear models were considered for establishing G/GMAx and D for the Saddle Mountains Basalt interbeds. The model proposed by Darendeli (2001) was considered viable for the interbeds and was adopted because it offers more flexibility and accounts for confining stress dependence which is important for the depths at which the interbeds are located (PNNL. 2014). The Darendeli (2001) equations for damping have two separate terms. The first term is independent of strain and controls low-strain damping. As with the basalt members, this strain term was estimated for the interbeds as a function of the inverse of Vs (PNNL, 2014). The second term represents hysteretic damping and is strain-dependent. This term has very low values at low strains but is the dominant term at high strains. The damping curves for the interbeds are constructed as the sum of the low-strain damping (function of the inverse of Vs) and the hysteretic damping term (PNNL, 2014). Examination of the PNNL (2014) interbed damping curves indicates that the low-strain damping term is reduced with increasing strain, and only the hysteretic portion is used at shear strains above about 0.05%. All four interbeds have very large confining stresses, with the deepest interbed (Mabton) having the most and the shallowest interbed (Rattlesnake Ridge) having the least. This results in the Mabton interbed having slightly less G/GMAx reduction with increasing shear strain than the Rattlesnake Ridge interbed. Similarly, the Mabton interbed has slightly less damping with increasing shear strain than the Rattlesnake Ridge interbed. The Cold Creek interbed (shallower than the Mabton and deeper than the Rattlesnake Ridge) has G/GMAx and D curves that are between (but very close to) those of the Mabton and Rattlesnake Ridge interbeds. These Cold Creek curves will be used to illustrate the G/GMAx and D values for the interbeds. The Cold Creek interbed curves (derived from PNNL, 2014) for G/GMAxand D versus shear strain are shown in Figure 2.3.2.1-3. The tabulated values of these curves are given in Table 2.3.2.1-5 for G/GMAx and D. As noted in EPRI (2013a), D values are limited to 15% in the rock column analysis. The uncertainty of G/GMAx and D for the interbeds is treated the same way as for the overlying soils, as described in Section 2.3.2. 1 .1. 36 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.2.1-1: Shear-Modulus Reduction Curves for the EPRI (1993) Model G/GMAX Shear Strain (%) 0-20 ft 20-50 ft 50-120 ft 120-250 ft 250-500 ft 500-1000 ft 0.0001 1.0 1.0 1.0 1.0 1.0 1.0 0.000316 1.0 1.0 1.0 1.0 1.0 1.0 0.001 0.99 0.995 0.995 0.995 1.0 1.0 0.00316 0.92 0.95 0.97 0.98 0.99 0.995 0.01 0.76 0.83 0.88 0.91 0.94 0.96 0.0316 0.50 0.60 0.70 0.75 0.80 0.86 0.1 0.28 0.36 0.44 0.50 0.57 0.65 0.316 0.125 0.18 0.23 0.28 0.33 0.40 1.0 0.05 0.075 0.10 0.13 0.16 0.20 Table 2.3.2.1-2: Damping Ratio Curves for the EPRI (1993) Model Damping Ratio (%)111 Shear Strain {%) 0-20 ft 20-50 ft 50-120 ft 120-250 ft 250-500 ft 500-1000 ft 0.0001 1.5 1.25 1.0 1.0 1.0 0.5 0.000316 1.5 1.25 1.0 1.0 1.0 0.5 0.001 2.0 1.5 1.25 1.0 1.0 0.5 0.00316 2.6 2.0 1.5 1.25 1.1 0.75 0.01 5.0 3.5 2.7 2.2 2.0 1.25 0.0316 9.5 7.5 5.7 4.2 3.6 2.5 0.1 15.1 12.5 10.3 8.75 7.3 5.1 0.316 22.0 19.0 16.5 14.5 12.8 10.2 1.0 27.5 24.7 22.6 20.8 19.0 16.2 (1) Damping is limited to 15% maximum in the soil column analysis. 37 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.2.1-3: The Shear-Modulus Reduction and Damping Ratio Curves for the Peninsular Range (Silva et al., 1997) model G/GMAX Damping Ratio (%)w Shear Strain (%) 0-50 ft 50-500 ft 0-50 ft 50-500 ft 0.0001 1.0 1.0 1.1 0.5 0.000316 1.0 1.0 1.1 0.5 0.001 1.0 1.0 1.3 0.5 0.00316 0.96 0.99 1.6 0.9 0.01 0.85 0.95 3.0 1.4 0.0316 0.67 0.84 5.5 2.6 0.1 0.43 0.64 10.3 5.5 0.316 0.22 0.40 16.5 10.3 1.0 0.09 0.20 22.8 16.5 ( 1) Dam ping is limited to 15% maxim um in the soil column analysis. Table 2.3.2.1-4: Selected G/Gmax and Damping Ratio Curves for Depths Above 525 ft Material Depth Top El. G/GMAx & D Curves111 (ft) {ft) EPRI Peninsular Sand 0-6 440 Sand 6-13 434 0-20 ft 0-50 ft Sand 13-21 427 Sand 21-45 419 Middle Ringold 45-56 395 20-50 ft Middle Ringold 56-85 384 50-120 ft Middle Ringold 85-250 355 120-250 ft 50-500 ft Lower Ringold 250-300 190 Lower Ringold 300-325 140 250-500 ft Lower Ringold 325-525 115 Saddle Mtn. Basalt . -85 (1) Analyses are performed using both the EPRI and Peninsular curves, with equal weighting for each. 38 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.2.1-5: Cold Creek lnterbed G/Gmax and Damping Ratio Versus Shear Strain G/GMAX Damping Ratio Shear Strain (%) (%fl 0.0001 1.0 1.8 0.000316 1.0 1.85 0.001 0.99 1.9 0.00316 0.97 2.0 0.01 0.90 2.8 0.0316 0.77 4.2 0.1 0.53 8.0 0.316 0.28 14.0 1.0 0.12 20.0 (1) Damping is limited to 15% maximum in the rock column analysis. 39 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure ';::::;'--...... ._ O.B ,..o.s 1,9 ...... 1,9 0.4 -.:* -20 ft --20-SC* ft 3D. 12Co ft --110 -2.50:* ft 0.1 250 -3C(* ft 3 DD -lCO:O:* f: D a.DOD 1 D.CO:*l rn -o-2att 25 --20-50 f: SQ* 12D :: :f;. --120 -2 50 ft -Ill 2.50 -.5 DD ft .: 15 Cir.. E 500 -lDDa ft IS Q 10 .5 -... .... ... ..... ... ' o.o.:. ' ' ' She-ar Strain(%) -... --.. ,-... i) O.DOOl 0.001 D.01 Shear Strain(%) .... ' ' ' D.l / ... .. ,,.. 0.1 .,., ' 1 , " / ,, , Figure 2.3.2.1-1: EPRI G/Gmax and Damping Ratio Curves (EPRI, 1993) 40 of 136 l RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure ......... .... ' ' ' ' ' ' ' ' ' ' ' ' " ' ' ' ' ..... ' 0 ______ ....._ ____ ....._ ____ ..__ ____ ..__ ____ ..__ ____ .....__ ____ ....._ __ ___, -4.0 -3.S -3.D -2. s -2. 0 -1.5 -1.0 -0.'5 o.o CCI ,...., N1 .1 LEGoiD r ---0-50 n N I 51-lO:C: ., .,., c:i ---£ N: v ' ui c: N c t. ID ,.... ,.... / ,,..,.... __ ..... / / / / / / / / / / / / /. / / O "------....._ ____ ....._ ____ ..__ ____ _._ ____ ..__ ____ ....__ ____ ....._ __ ___J -.:i.O -3.5 -3.D -2.S -2.0 -1. s -1. 0 -0. s 0. Cl log <Shedr Strain -MODULUS REDUCTJON AND DRMP!NS CURVE5 SOILS Figure 2.3.2.1-2: Peninsular G/Gmax and Damping Ratio Curves (Silva et al., 1997) 41 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 1 0.9 0.8 0.7 x 0.6 Ill o.s " C> 0.4 0.3 0.2 0.1 0 0.0001 20 18 16 .2 12 1ii Ci:: 10 *a. 8 E " c 6 4 2 0 0.0001 0.001 0.001 0.01 Shear Strain (%) -G/GMAX 0.01 Shear Strain (%) -Damping Ratio(%) 0.1 1 0.1 1 Figure 2.3.2.1-3: Cold Creek lnterbed G/Gmax and Damping Ratio Curves (PNNL, 2014) 42 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 2.3.2.2 Kappa The site attenuation parameter (Ko) at the CGS is dependent on the supra-basalt sediments, the SMB stack, and the input motion. The PNNL (2014) report documented an extensive study regarding the Ko contributions of the SMB stack and the input motion. In the study, the empirical estimates of the Ko were computed using two methods and recordings from 59 earthquakes recorded at 6 different sites around the Hanford site. The result of the study was the distributions of Ko at the reference condition (i.e., input motion horizon) and at the top of the SMB stack, shown in Figures 2.3.2.2-1 and 2.3.2.2-2, respectively. No explicit consideration of the contribution of the supra-basalt sediment to the total Ko was made. Instead, this contribution was based on the low strain damping from the assigned soil strain-dependent nonlinear curves. The site attenuation parameter (Ko) at the surface of the site is a combination of the contributions at the reference rock horizon (Ko.ref) and the wave propagation through the site (8K0= K0-Ko,ref). The 8K0 value is computed by the linear-elastic transfer function for the site profile using each of the four base soil case profiles with and without damping following the procedure by Boore and Joyner (1997). For each transfer function, the log-linear slope (6.Ko) is computed. The 6.Ko value is defined as the difference of these two slopes (6.Ko.damping -6.Ko,no damping). The transfer function without damping is used to isolate the effects of the velocity profile from the effects of the damping on the slope transfer function. For example, the linear-elastic transfer functions for the C1-EPRI site profile are computed, as well as the logarithmic mean of transfer functions, shown in Figure 2.3.2.2-3. The .1.Ko,damping is then computed to be 0.0085 s using log-linear fit between 60 and 200 Hz to the logarithmic mean transfer function as shown in Figure 2.3.2.2-3. The 6Ko,no damping is computed to be -0.0002 as shown in Figure 2.3.2.2-4. The .1.Ko,nodarnping value is relatively small because of the selected frequency range and the characteristics of the velocity profile at the site. For the C1-EPRI case profile, this approach provides a .1.Ko value of 0.0087 s. The values for all four site profiles are provided in Table 2.3.2 .2-1. PNNL (2014) provides Ko,ref values tor the C1 and C2 SMB profile, presented in Table 2.3.2.2-2. Using the weights from Figure 7.61 of PNNL (2014), the logarithmic weighted average of Ko.ref is computed to be 0.0205 s. These values are significantly larger than the 8Ko computed for the site, which indicates that the reference condition is controlling the total site attenuation (Ko). The total site attenuation (Ko= 8Ko +Ko.ref) for the four profiles is provided in Table 2.3.2.2-3 and that shows a variation between 0.0287 and 0.0357 s. A log-normal standard deviation of 0.4 is used in randomization to model the uncertainty in the strain-independent damping ratios. 43 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.2.2-1: The Incremental Site Attenuation (ti.KO) for the Four Base-Case Profiles SMB Velocity Model Nonlinear Model C1 C2 EPRI 0.0087 s 0.0086 s PEN 0.0065 s 0.0064 s Table 2.3.2.2-2: The Reference (i.e., base rock) Site Attenuation (Ko,rei) for the Cl and C2 SMB Profiles (Table 7.25 of PNNL, 2014) SMB Velocity Model C1 I C2 Kore! 0.0222 s I 0.0271 s Table 2.3.2.2-3: The Total Site Attenuation (Ko) for the Four Base-Case Profiles SMB Velocity Model Nonlinear Model C1 C2 EPRI 0.0309 s 0.0357 s PEN 0.0287 s 0.0335 s 44 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 0.25 0.20 0.15 0.10 0.05 0.00 I I I I I I

• Reference Kappa (sec) Figure 2.3.2.2*1: Site Attenuation (kappa) at the Reference Condition (Figure 7.66 from PNNL, 2014) 45 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 0.25 0.20 0.15 0.10 0.05 0.00 I I I °-oo 73 °-008 O.o,o O.o,s °-o<o °-o<s 0.030 0.038 °-0-10 O.o"s °-os0 °-os8 SMB Kappa (sec) Figure 2.3.2.2*2: Site Attenuation (kappa) at the SMB Stack (Figure 7.63 from PNNL, 2014) 46 of 136 I 0.06'0 0.03, RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 1.0E*01 1.0E+OO ----Q. E < c: 0 ts 1.0E*01 c: "' u.. ... c: .. 1.0E-02 1.0E-03 0.1 -Logarithmic Mean Fi1 Profile: c 1-epn t.KO [sec): 0.0085 Frequency [Hz) 10 \ \ \ 100 Figure 2.3.2.2-3: Fit Between the Geometric Mean Transfer Function and the Log-Linear Model for the C1-EPRI Base-Case Site Profile with Damping 47 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Q. E < c: 1.0E*01 1 OE+OO c: "' u.. ... c: .. 1 OE-01 0.1 -Logarithmic Mean Fit Profile: c 1-epn t.KO [sec): -0.0002 Frequency [Hz) 10 100 Figure 2.3.2.2-4: Fit Between the Geometric Mean Transfer Function and the Log-Linear Model for the C1-EPRI Base-Case Site Profile without Damping 2.3.3 Randomization of Base Case Profiles The simulated base case profiles for the CGS site include both aleatory and epistemic uncertainty. The site profile consists of an upper supra-basalt zone and the lower SMB stack. The epistemic uncertainty of the supra-basalt zone is characterized by a single base-case velocity profile and two different models tor the nonlinear behavior of the soil. The EPRI (1993) and Peninsular (PEN) Range (Silva et al., 1997) are used and given equal weight. PNNL (2014) provides two sets (C1 and C2) of sixty simulated profiles and associated nonlinear curves for the Saddle Mountain Basalt zone tor the CGS site (Site C). The two sets of simulated profiles correspond to profiles developed using different rock velocity measurement methods. As described in Section 7.2.6 of PNNL (2014), C1 profiles are based on down-hole measurements and given a weight of 0.67, while the C2 profiles are based on PS suspension logging measurements and given a weight of 0.33. The weight for each of the considered profiles is summarized in Table 2.3.3-1. Combining the 2 base profiles representing the supra-basalt and the 2 base profiles representing the lower SMB stack, a total of 4 base profiles are selected for simulation. The 48 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure simulated profiles for the lower SMB stack {60 profiles for each base case) are provided in PNNL {2014). For the supra basalt, variability in the shear-wave velocity profiles has been incorporated in the soil profile simulation to account for the aleatory variability in material properties that is expected to occur across a site at the scale of a typical nuclear facility. For the CGS site, simulated wave velocity profiles were developed from the base case profiles, as presented in Section 2.3.2. The simulation procedure generates a set of sixty site-specific simulated (randomized) soil profiles to represent the dynamic properties of the site while considering the uncertainty associated with each of these properties, and correlations between different parameters. Simulated profiles were generated for the supra-basalt zone, and were subsequently augmented with the simulated profiles provided for the Site C SMB stack in Appendix J of PNNL (2014). As specified in the SPID (EPRI, 2013a), correlation of shear wave velocity between layers was modeled using the USGS B correlation model. In profile simulation, a limit of+/- 2 standard deviations about the median value in each layer was assumed for the limits on random velocity fluctuations, as well as on strain-dependent shear modulus reduction and damping ratios. The simulated damping ratios are limited to a maximum of 15%. The variation in the thickness and S-wave velocity of the supra-basalt layers is presented in Table 2.3.3-2. The variation for the SMB stack is described in Sections 7 and 9 of PNNL (2014). The hard-rock half-space is defined by an S-wave velocity of 9,840 ft/s, a unit weight of 0.177 kcf, and a damping ratio of 0.1% as defined by Section 9.6.1 of PNNL (2014). The combined simulated velocity profiles with the C1 Saddle Mountain Basalt profiles are shown in Figures 2.3.3-1 and 2.3.3-2. Similarly, the C2 Saddle Mountain basalt profiles are shown in Figures 2.3.3-3 and 2.3.3-4. The EPRI and PEN simulated shear-wave velocity profiles have the same simulated velocity profiles, and only have different shear modulus reduction and damping ratio curves. Table 2.3.3-1: The Weight Factors for the Four Base-Case Profiles SMB Velocity Model Nonlinear Model C1 (0.67) C2 (0.33) EPRI (0.5) 0.335 0.165 PEN (0.5) 0.335 0.165 49 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.3-2: Variation of the Thickness and S-wave Velocity in the Supra-Basalt Zone Thickness S-Wave Velocity Stratum Unit Variation Uncertainty, 01nvs P-1 Pasco Gravel +/-22% 0.25 P-2 Pasco Gravel +/-22% 0.25 P-3 Pasco Gravel +/-22% 0.25 P-4 Pasco Gravel +/-22% 0.25 MR-1 Middle Ringold +/-10% 0.25 MR-2 Middle Ringold +/-10% 0.15 MR-3 Middle Ringold +/-10% 0.15 LR-1 Lower Ringold +/-15% 0.15 LR-2 Lower Ringold +/-15% 0.30 LR-3 Lower Ringold +/-15% 0.20 50 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 200 400 CV 600 -0 ttl ,_ (.,!) 0 Qi ca 800 ...... a. CV 0 1000 1 10 20 30 Realization 40 1500 3000 4500 6000 7500 9000 10500 12000 so 60 Figure 2.3.3-1: Bar Plots of the Combined Simulated Site Profiles with the C1 SMB Profile 51 of 136 -V\ --.:t: ->-:!: u 0 Q) > Ill ..!. Ill (]) Ul RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 200 400 v 600 -0 ttl ,_ (.!) 0 Qi co 800 ...... a. Q) 0 1000 1200 1400 0 2000 ***-.... 4000 6000 8000 Shear-Wave Velocity [ft/sec] Realization Median 10000 12000 Figure 2.3.3-2: Line Plots of the Combined Simulated Site Profiles with the C1 SMB Profile 52 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 200 400 CV 600 -0 ttl ,_ (.,!) 0 Qi ca 800 ...... a. CV 0 1000 1 10 20 30 Realization 40 1500 3000 4500 6000 7500 9000 10500 12000 so 60 Figure 2.3.3-3: Bar Plots of the Combined Simulated Site Profiles with the C2 SMB Profile 53 of 136 -V\ --.:t: ->-:!: u 0 Q) > Ill ..!. Ill (]) Ul RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 200 400 ..... . . **-.... ***-* v 600 -0 ttl ,_ (.!) 0 Qi co 800 ...... a. Q) 0 1000 1200 1400 0 2000 4000 6000 8000 Shear-Wave Velocity [ft/sec] 10000 Realization Median 12000 14000 Figure 2.3.3-4: Line Plots of the Combined Simulated Site Profiles with the C2 SMB Profile 54 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 2.3.4 Input Spectra Appendix J of PNNL (2014) provides the hard-rock hazard and site-specific horizontal 5% damped hard-rock acceleration response spectra (ARS) calculated at bedrock with an S-wave velocity of 9,840 ft/s (3,000 m/s). The data for Site C designated for the CGS is used. In the site response analysis simulations, the rock ARS are used as outcrop motions at the bedrock horizon, which is defined by an S-wave velocity of 9,840 ft/s. The rock horizon is identified as top of the Lalo formation in Section 7.2.5 of PNNL (2014). The input motions are provided as both scaled mean spectra and conditional mean spectra (CMS). The site response analyses presented in this report use the CMS. Baker (2010) proposed the concept of the CMS in which a mean response spectrum is modified to fit a target spectral acceleration at a specific frequency, which is referred to as the conditioning frequency. The spectral accelerations at the other frequencies are computed by the Baker (2010) relationship, which provides for realistic scaling of the ground motions. PNNL (2014) provides CMS spectra at the mean annual frequencies of exceedance (MAFEs) and frequencies presented in Table 2.3.4-1. With a total of 4 event spectra for each of the 20 frequencies and the total of 27 MAFEs, a total of 2, 160 spectra were used for each of the simulated profiles for site response analysis. The magnitude and distance of each event is dependent on the deaggregation, and thus vary with MAFE and conditioning frequency. At MAFE of 10-4, the mean magnitude and distances computed for the 20 frequencies of the 4 events are: 0) Mw 5.5 at 5.6 mi (9 km), 1) Mw 6.5 at 7.5 mi (12 km), 2) Mw 7.2 at 13 mi (21 km), and 3) Mw 9.0 at 207 mi (333 km). Examples of the CMS for conditioning frequencies of 1 and 10 Hz and a MAFE of 10"4 are shown in Figures 2.3.4-1 and 2.3.4-2, respectively. The scenario magnitude and distance listed in Figures 2.3.4-1 and 2.3.4-2 are specific to the conditioning frequency and MAFE. In some cases, the weight factor of an event may be zero (see Mw=9.1 event in Figure 2.3.4-2). In the CMS motions provided in PNNL (2014), the methodology is limited to only increase the spectral acceleration at the conditioning frequency. In addition to the acceleration response spectrum, the duration and effective strain ratio need to be defined for each of the input motions. The ground motion duration is estimated using the magnitude and distance of the events listed in CMS text files along with the WUS duration model (Equation H-9) of NUREG/CR-6728 (McGuire. 2001). The durations range from 1.5 to 60.4 seconds and correspond to earthquakes with moment magnitudes from 5.4 to 9.2. For materials with nonlinear properties, the effective strain ratio, which relates the peak shear strain to the effective shear strain, is computed using the following equation from Idriss and Sun (1992): Yeff Mw = (2.3.4-1) Ymax 10 Using the magnitudes reported in CMS text files, the effective strain ratio is computed for each of the events. The effective strain ratios range from 0.44 to 0.82. 55 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.4-1: The MAFE and Conditioning Frequencies of the Conditional Mean Spectra (PNNL, 2014) MAFE Frequency [Hz] 1.00E-02 100.000 7.52E-03 50.000 5.00E-03 33.333 3.00E-03 25.000 2.00E-03 20.000 1.00E-03 13.333 7.50E-04 10.000 5.00E-04 6.667 4.00E-04 5.000 3.00E-04 3.333 2.00E-04 2.500 1.00E-04 2.000 7.SOE-05 1.333 5.00E-05 1.000 3.00E-05 0.667 2.00E-05 0.500 1.00E-05 0.333 7.50E-06 0.200 5.00E-06 0.133 3.00E-06 0.100 2.00E-06 1.00E-06 7.SOE-07 5.00E-07 3.00E-07 2.00E-07 1.00E-07 56 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Cl (I) u 10*1 u 4: Ctl ,_ ..... u (I) a_ Ill -0 (I) a_ E io*2 Ctl 0 '#. U"l Frequency [Hz] ........ 1.0 Hz, AEF: l.Oe-04 UHRS .11 .. : 5.6, R: 7 km, Wt: 0.15 .11 .. : 6.5, R: 11 km, Wt: 0.39 .\/,.: 7.2. R: 20 km. Wt: 0.25 -11,.: 9.0, R: 336 km, Wt: 0.21 Figure 2.3.4-1: The Four Input Rock Conditional Mean Spectra with a Conditioning Frequency of 1 Hz and a MAFE of 10*4.Compared with the Hard-Rock Uniform Hazard Response Spectrum 57 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 101 CMS 10° cu 10*1 It) ... .., u (IJ a_ VI -0 (IJ Cl. 10*2 0 '# U"'t ---*-* -* * * * * * * * * * * * * * * * * * * * * * * * * -* * * * * * * * * * * * * * * * -* * ------------. 10.0 Hz, AEF: l.Oe-04 -UHRS H : 5.4, R 10 km, Wt 0.46 \/,. : 6-4. R: 12 km. Wt: 0.37 .ll,. : 7 .2. R: 20 km. Wt: 0.17 ll,.: 9.1. R: 328 l<m. Wt: 0.00 io*4 L. ________ .J...._ _______ -=:::c::::=======::::::::=..J 10*1 10° 101 102 Frequency [Hz] Figure 2.3.4-2: The Four Input Rock Conditional Mean Spectra with a Conditioning Frequency of 10 Hz and a MAFE of 10*4.Compared with the Hard-Rock Uniform Hazard Response Spectrum 58 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 2.3.5 Methodology To perform the site response analyses for the CGS site, a random vibration theory (RVT) approach and the computer program P-SHAKE was used. This process utilizes a simple, efficient approach for computing site-specific amplification functions and is consistent with existing NRC guidance and the SPID (EPRI, 2013a). Each set of sixty simulated profiles based on the 4 base profiles (4 x 60 = 240), presented in Section 2.3.3, are subjected to the 2, 160 hard rock spectra, presented in Section 2.3.4, at the top of hard rock, which is characterized by a minimum shear-wave velocity of 9,840 ft/s (3,000 mis). The 5% damped acceleration response spectra at the ground surface (SSE control point) are computed, and the amplification functions are calculated as the ratio of the surface response spectra to the hard rock spectra both at 5% spectral damping. For a set of sixty site profile realizations, the logarithmic mean amplification function is computed by: and associated logarithmic standard deviation (a1n) is then computed as N CT1n = N 1 L (In mi -µ1n)2 i=l (2.3.5-1) {2.3.5-2) where m; is is the i-th site amplification. At each MAFE and CMS conditioning frequency, there are four values of µ1n and a1n provided by the four different events. From these four values, the weighted average of the logarithmic mean amplification is computed by: (2.3.5-3) where µ1n.i is the logarithmic mean site amplification for event i and w; is the weight assigned to event i. These weight factors are provided for each of the 2, 160 events in PN NL {2014). The total logarithmic standard deviation (o-1n,r) is computed by: O'tn.T = L Wi [ (µ1n.i -µln,T )2 + i (2.3.5-4) where µ1n.i is the logarithmic mean site amplification for event i, o-111.i is the logarithmic standard deviation for event i, and w; is the weight assigned to event i. This process is repeated for all MAFE and CMS conditioning frequencies to develop the site am pl if ication for one of the case profiles, and then repeated tor the remaining three base-case profiles. As a result, tor each base profile and each MAFE and each frequency for which CMS is provided, the associated logarithmic mean and total standard deviation of the amplification is obtained. 59 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 2.3.6 Amplification Functions The site amplification functions that are developed rely on 518,400 site response analyses, which were carried out for the: 240 simulated profiles from 4 base case profiles {60 simulated profiles for each base case), 20 conditioning frequencies with 4 CMS, 27 mean MAFEs. All different cases are analyzed and processed the same way, thus only a portion of these analyses are taken as examples and are discussed in detail in this report. The portion of site response analyses to be discussed herein is for the sixty simulated profiles for a C1-EPRI profile, CMS period of 0.1 s, MAFE of 1 o-4, and earthquake event 1. The resulting 5% damped surface acceleration response spectra (ARS) and logarithmic mean ARS for one case is shown in Figure 2.3.6-1. The site amplification is computed as the ratio of the surface ARS to the rock (i.e., at outcrop input layer) ARS both at 5% spectral damping, shown in Figure 2.3.6-2. The logarithmic mean using Equation 2.3.5-1 and logarithmic standard deviation using Equation 2.3.5-2 are computed from the sixty realizations, shown in Figure 2.3.6-3. The logarithmic standard deviation is shown in Figure 2.3.6-4. An important characteristic of the site response analyses is the large variability (i.e., large standard deviation) in the response between 2 and 6 Hz, which correspond to natural frequencies of the site. This characteristic is observed in the ARS (Figure 2.3.6-1) and site amplification (Figure 2.3.6-2) and is present to a varying degree in all of the considered cases. For a specific profile and CMS frequency, the arithmetic mean, logarithmic mean, and logarithmic standard deviation from all of the analyses (27 MAFEs and 4 events) are collected together. The weight factors are shown in Figure 2.3.6-5. Using these weight factors, the weighted average of the logarithmic mean site amplification are computed using Equation 2.3.5-3 as shown in Figure 2.3.6-6. The total standard deviation is computed using Equation 2.3.5-4 as shown in Figure 2.3.6-7. The results indicate that as the intensity of the input motion increases (i.e., decreasing MAFE) the 10 Hz site amplification decreases (see Figure 2.3.6-6). This decrease in site amplification is associated with an increase in total standard deviation. This behavior is attributed to the nonlinear response of the site. The composite site amplification (weighted average logarithmic mean and total standard deviation) is developed for each profile. The weighted average logarithmic mean for the C1-EPRI profile are shown in Figure 2.3.6-8. The associated total standard deviations for the C1-EPRI profile are shown in Figure 2.3.6-9. As intensity increases (decreasing MAFE), the amplification tends to shift to lower frequency, due to strain softening, and the once significant 2"d and 3rd natural frequencies decrease. This decrease in amplification at the 2nd and 3rd natural frequencies (2 to 6 Hz) is attributed to varying natural frequencies, again due to strain softening, and is accompanied by an increase in uncertainty (quantified by the logarithmic standard deviation) over the same frequency range. The site amplification results from the other profiles show similar characteristics to the C1 -EPRI profile. 60 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure The logarithmic mean with +/-1 *crin variation of the C1-EPRI site amplification is shown in Figures 2.3.6-10 and 2.3.6-11. The site amplification tends to be a generally smooth curve. The logarithmic mean site amplification for the four profiles are shown in Figures 2.3.6-12 and 2.3.6-13. The profiles show similar behavior with increasing intensity. The weighted average logarithmic mean and total logarithmic standard deviation of the site amplification are presented in Tables 2.3.6-1 and 2.3.6-2 for the C1-EPRI base-case profile, Tables 2.3.6-3 and 2.3.6-4 for the C1-PEN base-case profile, Tables 2.3.6-5 and 2.3.6-6 for the C2-EPRI base-case profile, and Tables 2.3.6-7 and 2.3.6-8 for the C2-PEN base-case profile. It should be noted that in computing the amplification factors, the recommended minimum variability in the site amplification factors, which is defined as a function of spectral frequency from PNNL (2014), was not implemented in the calculation of the surface hazard. This minimum variability is intended include the variability in epistemic uncertainty of the site term and particularly important at low frequencies. However, comparison of the computed standard deviation with the suggested minimum variability shows that for frequencies less than 1 Hz, this minimum epistemic uncertainty is greater than the standard deviation values computed from the site response analysis. For frequencies greater than 1 Hz, the computed standard deviation values are greater than the recommended minimum values from PNNL (2014).These observed differences in the uncertainty would lead to an increase in the surface hazard for frequencies less than 1 Hz by a small margin (note that the as-computed surface hazard exceeds the SSE over this frequency range without the minimum requirement) and does not cause any change for frequencies greater than 1 Hz in the surf ace hazard. Since the refinement using the minimum requirement does not affect the assessment presented in this report, the comparison of GMRS to the SSE (see Section 4.0), and the HCLPF as defined in terms of PGA (see Section 5.0), no further refinement of GMRS is considered. Another point to be noted is the evaluation of the minimum value for soil amplification function. At some frequencies, the calculated site amplification for high base rock amplitudes is less than the minimum value of 0.5 recommended by the SPID (EPRI, 2013a). The 0.5 limit is not imposed here in the calculation of the surface hazard because the intended purpose of this report is to obtain the best estimate of the mean and fractile levels of the seismic response for plant risk assessment with no added conservatism. 61 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.6-1: Weighted Average Logarithmic Mean of the 5% Damped Site Amplification for Base-Case Profile C1-EPRI Period [s] 0.01 0.02 0.03 0.04 0.05 0.08 0.10 0.15 0.20 0.30 0.40 0.50 0.75 1.00 1.50 2.00 3.00 5.00 7.50 10.00 Freauencv [Hzl 100.00 50.00 33.33 25.00 20.00 13.33 10.00 6.67 5.00 3.33 2.50 2.00 1.33 1.00 0.67 0.50 0.33 0.20 0.13 0.10 1.00E-02 1.047 0.900 0.951 1.019 0.968 1.069 1.238 1.796 3.074 3.223 1.671 1.969 2.214 2.453 2.700 1.953 1.444 1.233 1.173 1.147 7.52E-03 0.968 0.847 0.904 0.973 0.923 1.032 1.201 1.756 3.006 3.204 1.684 1.971 2.215 2.447 2.706 1.952 1.432 1.224 1.155 1.130 5.00E-03 0.899 0.791 0.850 0.914 0.865 0.963 1.130 1.687 2.887 3.158 1.700 1.974 2.217 2.437 2.707 1.946 1.424 1.205 1.136 1.117 3.00E-03 0.817 0.733 0.790 0.849 0.802 0.896 1.058 1.607 2.725 3.087 1.715 1.969 2.219 2.419 2.713 1.950 1.421 1.194 1.125 1.113 2.00E-03 0.741 0.686 0.743 0.797 0.753 0.841 0.997 1.537 2.584 3.022 1.731 1.967 2.217 2.402 2.716 1.961 1.419 1.189 1.124 1.114 1.00E-03 0.653 0.595 0.650 0.694 0.655 0.739 0.885 1.399 2.315 2.849 1.753 1.965 2.212 2.359 2.729 1.987 1.419 1.182 1.118 1.116 7.50E-04 0.610 0.559 0.611 0.655 0.619 0.700 0.840 1.329 2.193 2.768 1.758 1.969 2.212 2.344 2.736 2.001 1.420 1.180 1.116 1.117 >-5.00E-04 0.553 0.508 0.555 0.595 0.561 0.642 0.774 1.232 2.032 2.616 1.753 1.976 2.211 2.325 2.746 2.022 1.426 1.177 1.114 1.115 0 4.00E-04 0.523 0.483 0.527 0.565 0.533 0.613 0.742 1.182 1.945 2.548 1.747 1.981 2.217 2.313 2.755 2.035 1.429 1.176 1.113 1.115 c Q) 3.00E-04 0.481 0.449 0.486 0.522 0.494 0.574 0.700 1.120 1.843 2.459 1.738 1.979 2.232 2.306 2.763 2.056 1.433 1.179 1.112 1.115 ::J O" 2.00E-04 0.418 0.399 0.428 0.468 0.446 0.524 0.645 1.033 1.705 2.350 1.715 1.959 2.255 2.293 2.784 2.084 1.441 1.177 1.110 1.114 Q) ..... LL 1.00E-04 0.339 0.325 0.354 0.389 0.375 0.450 0.566 0.897 1.471 2.167 1.648 1.910 2.306 2.295 2.822 2.139 1.458 1.175 1.107 1.114 Q) 7.50E-05 0.309 0.301 0.327 0.361 0.350 0.424 0.538 0.846 1.390 2.088 1.613 1.876 2.316 2.304 2.827 2.166 1.466 1.174 1.106 1.113 0 c 5.00E-05 0.276 0.267 0.329 0.321 0.387 0.495 0.783 1.269 1.963 1.555 2.310 2.307 2.833 2.208 1.480 1.174 1.105 ca 0.298 1.828 1.109 "U Q) 3.00E-05 0.242 0.228 0.261 0.289 0.287 0.348 0.451 0.707 1.136 1.803 1.475 1.759 2.283 2.282 2.846 2.257 1.499 1.174 1.103 1.102 Q) 0 2.00E-05 0.218 0.204 0.235 0.262 0.262 0.319 0.418 0.652 1.043 1.685 1.399 1.679 2.254 2.254 2.853 2.308 1.516 1.176 1.102 1.091 x w 1.00E-05 0.179 0.169 0.198 0.222 0.223 0.277 0.368 0.565 0.900 1.499 1.278 1.490 2.153 2.112 2.764 2.416 1.556 1.181 1.100 1.070 cU 7.50E-06 0.166 0.158 0.186 0.209 0.211 0.261 0.349 0.534 0.846 1.422 1.227 1.425 2.104 2.085 2.715 2.456 1.576 1.183 1.100 1.062 ::J c 5.00E-06 0.152 0.143 0.169 0.191 0.194 0.241 0.325 0.492 0.782 1.315 1.158 1.330 1.985 2.066 2.620 2.492 1.600 1.188 1.100 1.070 c <: 3.00E-06 0.134 0.127 0.151 0.172 0.175 0.217 0.296 0.445 0.706 1.187 1.068 1.226 1.906 1.937 2.456 2.515 1.636 1.197 1.099 1.058 2.00E-06 0.123 0.117 0.139 0.158 0.162 0.202 0.275 0.413 0.649 1.096 0.996 1.122 1.868 1.840 2.344 2.482 1.674 1.205 1.099 1.050 1.00E-06 0.106 0.100 0.121 0.138 0.141 0.177 0.243 0.361 0.556 0.955 0.880 1.000 1.592 1.644 2.217 2.367 1.764 1.226 1.099 1.040 7.50E-07 0.099 0.093 0.114 0.130 0.134 0.168 0.232 0.342 0.519 0.897 0.841 0.944 1.544 1.580 2.117 2.332 1.750 1.232 1.099 1.037 5.00E-07 0.091 0.086 0.105 0.120 0.124 0.156 0.216 0.316 0.477 0.815 0.795 0.881 1.476 1.420 1.964 2.297 1.776 1.243 1.099 1.036 3.00E-07 0.080 0.078 0.095 0.109 0.113 0.142 0.198 0.286 0.428 0.725 0.730 0.802 1.359 1.308 1.765 2.124 1.795 1.249 1.102 1.036 2.00E-07 0.066 0.071 0.089 0.102 0.105 0.133 0.185 0.265 0.393 0.664 0.681 0.752 1.264 1.258 1.590 1.937 1.787 1.260 1.106 1.036 1.00E-07 0.051 0.062 0.078 0.090 0.094 0.118 0.166 0.233 0.338 0.565 0.627 0.648 1.095 1.163 1.332 1.678 1.820 1.288 1.118 1.039 62 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.6-2: Total Logarithmic Standard Deviation of the 5% Damped Site Amplification for Base-Case Profile C1-EPRI Period [s] 0.01 0.02 0.03 0.04 0.05 0.08 0.10 0.15 0.20 0.30 0.40 0.50 0.75 1.00 1.50 2.00 3.00 5.00 7.50 10.00 Freauencv [Hzl 100.00 50.00 33.33 25.00 20.00 13.33 10.00 6.67 5.00 3.33 2.50 2.00 1.33 1.00 0.67 0.50 0.33 0.20 0.13 0.10 1.00E-02 0.299 0.294 0.273 0.316 0.309 0.309 0.287 0.291 0.360 0.475 0.356 0.315 0.130 0.121 0.152 0.133 0.076 0.048 0.045 0.035 7.52E-03 0.284 0.274 0.260 0.309 0.299 0.297 0.279 0.297 0.366 0.467 0.361 0.318 0.131 0.121 0.152 0.134 0.072 0.048 0.033 0.024 5.00E-03 0.264 0.249 0.245 0.301 0.285 0.285 0.272 0.312 0.380 0.454 0.371 0.321 0.133 0.123 0.152 0.135 0.072 0.038 0.033 0.038 3.00E-03 0.240 0.229 0.234 0.294 0.273 0.277 0.269 0.330 0.396 0.437 0.390 0.331 0.135 0.125 0.151 0.137 0.072 0.039 0.030 0.035 2.00E-03 0.228 0.222 0.231 0.291 0.269 0.273 0.269 0.346 0.408 0.425 0.400 0.340 0.139 0.128 0.149 0.140 0.072 0.037 0.029 0.037 1.00E-03 0.222 0.217 0.230 0.290 0.266 0.275 0.276 0.367 0.430 0.403 0.418 0.363 0.153 0.134 0.144 0.147 0.073 0.033 0.032 0.036 7.50E-04 0.221 0.218 0.232 0.290 0.266 0.278 0.280 0.374 0.442 0.397 0.425 0.376 0.163 0.138 0.143 0.151 0.074 0.033 0.032 0.036 >-5.00E-04 0.222 0.222 0.237 0.292 0.268 0.285 0.290 0.382 0.455 0.386 0.430 0.399 0.184 0.146 0.142 0.157 0.078 0.032 0.030 0.035 0 4.00E-04 0.224 0.225 0.241 0.294 0.271 0.290 0.295 0.386 0.462 0.387 0.433 0.415 0.200 0.152 0.143 0.161 0.080 0.032 0.030 0.035 c Q) 3.00E-04 0.228 0.231 0.250 0.301 0.277 0.298 0.304 0.390 0.470 0.393 0.435 0.435 0.225 0.163 0.144 0.166 0.083 0.033 0.030 0.035 ::J O" 2.00E-04 0.228 0.241 0.261 0.310 0.286 0.309 0.317 0.398 0.482 0.407 0.435 0.455 0.264 0.184 0.149 0.173 0.089 0.034 0.030 0.035 Q) ..... LL 1.00E-04 0.240 0.264 0.283 0.328 0.304 0.326 0.341 0.408 0.500 0.440 0.431 0.479 0.327 0.240 0.170 0.181 0.099 0.037 0.030 0.036 Q) 7.50E-05 0.246 0.273 0.292 0.337 0.310 0.333 0.351 0.413 0.508 0.454 0.433 0.487 0.347 0.274 0.182 0.185 0.103 0.038 0.029 0.036 0 c 5.00E-05 0.254 0.284 0.344 0.337 0.364 0.515 0.474 0.444 0.496 0.365 0.111 0.040 0.035 ca 0.300 0.318 0.418 0.318 0.204 0.189 0.029 "U Q) 3.00E-05 0.262 0.283 0.308 0.348 0.325 0.346 0.381 0.430 0.520 0.489 0.452 0.516 0.381 0.343 0.259 0.198 0.121 0.042 0.029 0.034 Q) 0 2.00E-05 0.269 0.291 0.318 0.359 0.334 0.354 0.394 0.438 0.530 0.501 0.456 0.524 0.396 0.369 0.304 0.217 0.132 0.044 0.029 0.031 x w 1.00E-05 0.279 0.304 0.335 0.377 0.349 0.364 0.413 0.454 0.550 0.532 0.485 0.544 0.433 0.352 0.357 0.284 0.158 0.050 0.029 0.025 cU 7.50E-06 0.283 0.308 0.340 0.383 0.353 0.367 0.421 0.460 0.558 0.539 0.496 0.561 0.454 0.374 0.373 0.300 0.169 0.053 0.029 0.023 ::J c 5.00E-06 0.288 0.314 0.350 0.392 0.361 0.371 0.429 0.468 0.568 0.551 0.510 0.579 0.464 0.431 0.385 0.317 0.183 0.059 0.030 0.025 c <: 3.00E-06 0.293 0.321 0.359 0.400 0.371 0.378 0.440 0.480 0.578 0.570 0.524 0.605 0.487 0.451 0.400 0.342 0.200 0.071 0.031 0.022 2.00E-06 0.297 0.326 0.368 0.408 0.376 0.380 0.449 0.489 0.585 0.591 0.536 0.619 0.534 0.457 0.424 0.354 0.219 0.082 0.032 0.020 1.00E-06 0.304 0.335 0.383 0.420 0.387 0.389 0.461 0.505 0.592 0.624 0.578 0.629 0.515 0.458 0.499 0.371 0.271 0.116 0.035 0.020 7.50E-07 0.307 0.340 0.390 0.426 0.392 0.392 0.467 0.510 0.591 0.630 0.588 0.638 0.538 0.462 0.525 0.395 0.244 0.130 0.038 0.019 5.00E-07 0.310 0.344 0.397 0.432 0.400 0.398 0.475 0.517 0.599 0.651 0.608 0.667 0.575 0.408 0.530 0.444 0.250 0.144 0.044 0.019 3.00E-07 0.334 0.351 0.407 0.441 0.408 0.405 0.485 0.528 0.611 0.665 0.626 0.693 0.612 0.401 0.544 0.485 0.257 0.142 0.054 0.020 2.00E-07 0.344 0.357 0.417 0.448 0.416 0.410 0.492 0.537 0.624 0.676 0.631 0.704 0.656 0.421 0.531 0.489 0.256 0.146 0.068 0.022 1.00E-07 0.297 0.366 0.430 0.460 0.428 0.420 0.506 0.554 0.631 0.673 0.662 0.671 0.661 0.450 0.492 0.495 0.303 0.161 0.111 0.028 63 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.6-3: Weighted Average Logarithmic Mean of the 5% Damped Site Amplification for Base-Case Profile C1-PEN Period [s] 0.01 0.02 0.03 0.04 0.05 0.08 0.10 0.15 0.20 0.30 0.40 0.50 0.75 1.00 1.50 2.00 3.00 5.00 7.50 10.00 Freauencv [Hzl 100.00 50.00 33.33 25.00 20.00 13.33 10.00 6.67 5.00 3.33 2.50 2.00 1.33 1.00 0.67 0.50 0.33 0.20 0.13 0.10 1.00E-02 1.173 1.029 1.087 1.164 1.081 1.181 1.369 1.934 3.312 3.377 1.717 2.014 2.249 2.483 2.727 1.965 1.450 1.237 1.176 1.150 7.52E-03 1.090 0.975 1.039 1.118 1.035 1.143 1.330 1.891 3.241 3.354 1.728 2.013 2.248 2.474 2.731 1.962 1.437 1.227 1.157 1.133 5.00E-03 1.017 0.917 0.983 1.056 0.973 1.068 1.254 1.814 3.111 3.299 1.740 2.011 2.244 2.460 2.726 1.955 1.428 1.208 1.139 1.119 3.00E-03 0.927 0.851 0.917 0.983 0.903 0.993 1.172 1.722 2.935 3.224 1.747 1.997 2.241 2.438 2.729 1.956 1.424 1.196 1.127 1.115 2.00E-03 0.842 0.796 0.863 0.923 0.848 0.930 1.103 1.641 2.779 3.162 1.758 1.989 2.236 2.419 2.731 1.967 1.421 1.191 1.125 1.115 1.00E-03 0.739 0.691 0.755 0.806 0.739 0.817 0.980 1.501 2.499 3.018 1.781 1.974 2.226 2.374 2.743 1.992 1.421 1.183 1.119 1.117 7.50E-04 0.690 0.649 0.710 0.762 0.700 0.775 0.934 1.437 2.377 2.954 1.787 1.972 2.221 2.357 2.749 2.004 1.422 1.181 1.117 1.118 >-5.00E-04 0.626 0.591 0.648 0.697 0.639 0.715 0.867 1.350 2.218 2.821 1.784 1.968 2.209 2.333 2.755 2.022 1.426 1.178 1.115 1.115 0 4.00E-04 0.592 0.564 0.617 0.665 0.609 0.686 0.835 1.304 2.131 2.758 1.778 1.966 2.205 2.316 2.762 2.033 1.429 1.176 1.114 1.115 c 3.00E-04 0.547 0.526 0.573 0.620 0.568 0.646 0.793 1.245 2.031 2.669 1.770 1.958 2.206 2.298 2.765 2.050 1.432 1.179 1.112 1.115 ::J O" 2.00E-04 0.478 0.471 0.511 0.563 0.518 0.595 0.736 1.159 1.896 2.549 1.752 1.938 2.209 2.271 2.777 2.073 1.438 1.177 1.111 1.115 Q) ..... LL 1.00E-04 0.392 0.390 0.430 0.478 0.442 0.519 0.653 1.017 1.664 2.340 1.699 1.895 2.226 2.240 2.794 2.117 1.451 1.174 1.107 1.114 7.50E-05 0.359 0.363 0.401 0.447 0.416 0.492 0.623 0.963 1.580 2.252 1.668 1.865 2.228 2.229 2.791 2.139 1.458 1.173 1.106 1.114 0 c 5.00E-05 0.325 0.411 0.454 0.577 1.458 2.127 1.611 1.821 2.229 2.210 2.782 2.172 1.470 1.172 1.105 ca 0.322 0.368 0.384 0.896 1.109 "U Q) 3.00E-05 0.284 0.281 0.326 0.365 0.346 0.413 0.529 0.814 1.325 1.982 1.533 1.748 2.211 2.186 2.759 2.208 1.485 1.172 1.103 1.103 0 2.00E-05 0.257 0.252 0.297 0.334 0.318 0.380 0.494 0.757 1.229 1.875 1.469 1.678 2.179 2.163 2.759 2.243 1.499 1.173 1.102 1.091 x w 1.00E-05 0.212 0.211 0.253 0.286 0.274 0.334 0.441 0.666 1.075 1.709 1.363 1.532 2.074 2.047 2.693 2.325 1.533 1.176 1.099 1.070 cU 7.50E-06 0.197 0.198 0.238 0.270 0.260 0.317 0.420 0.631 1.012 1.636 1.314 1.479 2.028 2.012 2.647 2.369 1.550 1.178 1.099 1.062 ::J c 5.00E-06 0.180 0.180 0.218 0.249 0.241 0.296 0.394 0.585 0.931 1.519 1.237 1.380 1.970 1.964 2.548 2.402 1.571 1.182 1.098 1.070 c <: 3.00E-06 0.159 0.161 0.197 0.225 0.219 0.269 0.362 0.532 0.841 1.377 1.157 1.279 1.895 1.869 2.463 2.390 1.601 1.190 1.098 1.058 2.00E-06 0.146 0.149 0.183 0.209 0.204 0.251 0.338 0.495 0.778 1.272 1.102 1.211 1.776 1.818 2.356 2.386 1.630 1.198 1.098 1.050 1.00E-06 0.126 0.128 0.160 0.184 0.181 0.223 0.303 0.436 0.681 1.120 0.995 1.098 1.629 1.642 2.189 2.354 1.679 1.217 1.096 1.039 7.50E-07 0.118 0.120 0.152 0.175 0.172 0.212 0.290 0.414 0.643 1.059 0.951 1.039 1.582 1.569 2.142 2.323 1.700 1.223 1.096 1.036 5.00E-07 0.109 0.111 0.141 0.164 0.160 0.198 0.271 0.385 0.595 0.974 0.897 0.972 1.464 1.482 2.033 2.251 1.732 1.231 1.097 1.035 3.00E-07 0.096 0.101 0.130 0.150 0.147 0.181 0.250 0.350 0.542 0.870 0.830 0.888 1.350 1.375 1.827 2.126 1.739 1.236 1.099 1.035 2.00E-07 0.079 0.094 0.121 0.141 0.138 0.170 0.235 0.325 0.500 0.804 0.773 0.828 1.279 1.301 1.672 2.003 1.748 1.245 1.103 1.035 1.00E-07 0.062 0.083 0.109 0.126 0.124 0.151 0.212 0.285 0.434 0.688 0.691 0.742 1.191 1.115 1.450 1.823 1.748 1.270 1.114 1.038 64 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.6-4: Total Logarithmic Standard Deviation of the 5% Damped Site Amplification for Base-Case Profile C1-PEN Period [s] 0.01 0.02 0.03 0.04 0.05 0.08 0.10 0.15 0.20 0.30 0.40 0.50 0.75 1.00 1.50 2.00 3.00 5.00 7.50 10.00 Freauencv [Hzl 100.00 50.00 33.33 25.00 20.00 13.33 10.00 6.67 5.00 3.33 2.50 2.00 1.33 1.00 0.67 0.50 0.33 0.20 0.13 0.10 1.00E-02 0.284 0.285 0.272 0.326 0.311 0.309 0.287 0.284 0.358 0.492 0.363 0.317 0.134 0.122 0.156 0.136 0.078 0.050 0.046 0.036 7.52E-03 0.272 0.269 0.263 0.323 0.304 0.300 0.282 0.290 0.366 0.484 0.367 0.320 0.134 0.123 0.155 0.136 0.074 0.049 0.034 0.024 5.00E-03 0.255 0.248 0.253 0.320 0.295 0.292 0.279 0.306 0.382 0.471 0.376 0.323 0.136 0.124 0.155 0.136 0.073 0.039 0.033 0.038 3.00E-03 0.236 0.233 0.248 0.318 0.289 0.287 0.279 0.325 0.399 0.457 0.394 0.332 0.138 0.126 0.154 0.139 0.073 0.039 0.031 0.036 2.00E-03 0.226 0.229 0.249 0.318 0.288 0.286 0.282 0.343 0.411 0.447 0.406 0.339 0.140 0.128 0.153 0.142 0.073 0.037 0.029 0.038 1.00E-03 0.225 0.226 0.252 0.320 0.287 0.289 0.292 0.374 0.430 0.432 0.428 0.355 0.151 0.134 0.149 0.149 0.074 0.034 0.032 0.037 7.50E-04 0.225 0.227 0.253 0.319 0.287 0.292 0.296 0.385 0.440 0.427 0.435 0.363 0.157 0.137 0.148 0.153 0.075 0.033 0.032 0.036 >-5.00E-04 0.227 0.230 0.254 0.321 0.289 0.298 0.303 0.397 0.451 0.413 0.442 0.379 0.168 0.142 0.147 0.158 0.078 0.033 0.031 0.035 0 4.00E-04 0.230 0.233 0.256 0.322 0.291 0.302 0.308 0.402 0.457 0.412 0.444 0.389 0.176 0.145 0.147 0.162 0.080 0.033 0.031 0.035 c Q) 3.00E-04 0.234 0.237 0.261 0.327 0.296 0.309 0.315 0.406 0.465 0.411 0.447 0.404 0.190 0.150 0.148 0.166 0.083 0.034 0.031 0.036 ::J O" 2.00E-04 0.233 0.246 0.272 0.336 0.303 0.320 0.326 0.411 0.478 0.415 0.454 0.423 0.219 0.159 0.151 0.172 0.087 0.034 0.031 0.036 Q) ..... LL 1.00E-04 0.244 0.267 0.292 0.354 0.319 0.341 0.344 0.415 0.498 0.434 0.461 0.461 0.276 0.190 0.164 0.180 0.096 0.036 0.030 0.036 Q) 7.50E-05 0.250 0.276 0.301 0.364 0.325 0.349 0.351 0.419 0.506 0.445 0.461 0.473 0.295 0.212 0.173 0.183 0.100 0.038 0.030 0.037 0 c 5.00E-05 0.258 0.288 0.311 0.370 0.357 0.424 0.519 0.466 0.486 0.243 0.187 0.107 0.040 ca 0.332 0.361 0.463 0.328 0.186 0.030 0.036 "U Q) 3.00E-05 0.266 0.290 0.320 0.373 0.339 0.369 0.374 0.434 0.531 0.493 0.466 0.499 0.357 0.285 0.216 0.190 0.116 0.042 0.030 0.034 Q) 0 2.00E-05 0.273 0.300 0.331 0.384 0.349 0.380 0.386 0.443 0.540 0.514 0.470 0.507 0.378 0.322 0.262 0.199 0.126 0.044 0.029 0.031 x w 1.00E-05 0.282 0.317 0.353 0.403 0.366 0.395 0.408 0.454 0.555 0.545 0.490 0.529 0.397 0.338 0.317 0.247 0.148 0.049 0.029 0.026 cU 7.50E-06 0.286 0.322 0.360 0.410 0.371 0.401 0.417 0.457 0.556 0.558 0.498 0.545 0.406 0.359 0.331 0.281 0.158 0.051 0.030 0.024 ::J c 5.00E-06 0.291 0.331 0.372 0.420 0.380 0.409 0.428 0.461 0.559 0.567 0.504 0.554 0.430 0.386 0.345 0.294 0.171 0.057 0.030 0.025 c <: 3.00E-06 0.296 0.341 0.384 0.432 0.393 0.419 0.443 0.469 0.568 0.577 0.521 0.568 0.471 0.401 0.389 0.301 0.185 0.068 0.031 0.022 2.00E-06 0.301 0.348 0.397 0.442 0.401 0.425 0.455 0.477 0.577 0.588 0.541 0.590 0.470 0.433 0.416 0.320 0.200 0.080 0.032 0.020 1.00E-06 0.309 0.362 0.415 0.459 0.416 0.436 0.470 0.494 0.596 0.620 0.572 0.620 0.500 0.445 0.458 0.369 0.210 0.114 0.035 0.019 7.50E-07 0.313 0.369 0.424 0.468 0.423 0.441 0.478 0.501 0.605 0.633 0.580 0.635 0.521 0.446 0.489 0.390 0.216 0.128 0.038 0.019 5.00E-07 0.318 0.377 0.434 0.477 0.433 0.448 0.487 0.509 0.622 0.645 0.591 0.652 0.529 0.454 0.529 0.410 0.243 0.140 0.043 0.018 3.00E-07 0.345 0.388 0.447 0.490 0.443 0.455 0.501 0.517 0.635 0.655 0.606 0.659 0.539 0.471 0.528 0.443 0.240 0.138 0.053 0.019 2.00E-07 0.360 0.397 0.458 0.500 0.451 0.460 0.509 0.524 0.639 0.650 0.611 0.676 0.572 0.478 0.529 0.469 0.252 0.139 0.067 0.021 1.00E-07 0.314 0.412 0.476 0.517 0.466 0.468 0.522 0.537 0.643 0.660 0.613 0.688 0.638 0.437 0.534 0.506 0.279 0.153 0.110 0.027 65 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.6-5: Weighted Average Logarithmic Mean of the 5% Damped Site Amplification for Base-Case Profile C2-EPRI Period [s] 0.01 0.02 0.03 0.04 0.05 0.08 0.10 0.15 0.20 0.30 0.40 0.50 0.75 1.00 1.50 2.00 3.00 5.00 7.50 10.00 Freauencv [Hzl 100.00 50.00 33.33 25.00 20.00 13.33 10.00 6.67 5.00 3.33 2.50 2.00 1.33 1.00 0.67 0.50 0.33 0.20 0.13 0.10 1.00E-02 0.930 0.787 0.807 0.804 0.786 0.960 1.037 1.556 2.805 2.983 1.536 1.848 2.199 2.376 2.662 1.962 1.446 1.231 1.170 1.144 7.52E-03 0.857 0.737 0.764 0.763 0.744 0.926 1.002 1.515 2.741 2.960 1.546 1.846 2.198 2.369 2.669 1.961 1.435 1.222 1.153 1.128 5.00E-03 0.793 0.687 0.715 0.711 0.692 0.862 0.937 1.448 2.632 2.910 1.556 1.844 2.197 2.357 2.670 1.957 1.428 1.205 1.135 1.115 3.00E-03 0.720 0.636 0.665 0.658 0.639 0.802 0.873 1.370 2.483 2.836 1.563 1.832 2.196 2.336 2.674 1.962 1.425 1.193 1.125 1.112 2.00E-03 0.652 0.595 0.626 0.618 0.600 0.753 0.820 1.303 2.353 2.770 1.573 1.822 2.191 2.318 2.675 1.975 1.424 1.189 1.123 1.113 1.00E-03 0.573 0.515 0.550 0.538 0.522 0.663 0.725 1.182 2.101 2.606 1.584 1.807 2.182 2.273 2.683 2.003 1.425 1.183 1.118 1.116 7.50E-04 0.536 0.485 0.519 0.510 0.495 0.628 0.688 1.122 1.984 2.528 1.587 1.804 2.180 2.257 2.688 2.018 1.427 1.181 1.116 1.116 >-5.00E-04 0.486 0.442 0.474 0.465 0.449 0.575 0.631 1.039 1.829 2.388 1.583 1.797 2.178 2.236 2.693 2.040 1.433 1.179 1.115 1.114 0 4.00E-04 0.459 0.421 0.451 0.443 0.427 0.549 0.604 0.994 1.743 2.326 1.578 1.794 2.181 2.222 2.700 2.055 1.438 1.177 1.114 1.114 c Q) 3.00E-04 0.423 0.392 0.417 0.410 0.396 0.513 0.567 0.941 1.644 2.243 1.572 1.781 2.189 2.210 2.704 2.076 1.443 1.180 1.113 1.114 ::J O" 2.00E-04 0.368 0.349 0.367 0.368 0.357 0.466 0.519 0.865 1.508 2.139 1.555 1.755 2.203 2.192 2.716 2.104 1.452 1.179 1.111 1.114 Q) ..... LL 1.00E-04 0.299 0.285 0.303 0.306 0.300 0.398 0.451 0.746 1.288 1.966 1.494 1.699 2.221 2.183 2.733 2.161 1.471 1.178 1.108 1.114 Q) 7.50E-05 0.273 0.263 0.281 0.283 0.280 0.375 0.427 0.703 1.214 1.892 1.460 1.669 2.221 2.183 2.728 2.190 1.480 1.177 1.108 1.113 0 c 5.00E-05 0.243 0.234 0.256 0.259 0.257 0.341 0.650 1.109 1.778 1.405 2.205 2.172 2.721 2.234 1.496 1.178 1.106 ca 0.392 1.624 1.109 "U Q) 3.00E-05 0.213 0.199 0.225 0.229 0.231 0.307 0.357 0.587 0.993 1.632 1.339 1.555 2.161 2.124 2.716 2.289 1.517 1.179 1.105 1.103 Q) 0 2.00E-05 0.192 0.178 0.203 0.208 0.210 0.281 0.331 0.542 0.910 1.513 1.278 1.502 2.112 2.075 2.680 2.339 1.537 1.182 1.104 1.091 x w 1.00E-05 0.157 0.147 0.170 0.176 0.178 0.243 0.292 0.471 0.786 1.318 1.182 1.358 2.053 1.971 2.529 2.417 1.584 1.187 1.103 1.071 cU 7.50E-06 0.146 0.137 0.160 0.165 0.168 0.230 0.277 0.445 0.741 1.246 1.138 1.302 1.998 1.912 2.463 2.441 1.607 1.190 1.102 1.063 ::J c 5.00E-06 0.133 0.124 0.145 0.151 0.155 0.213 0.258 0.410 0.684 1.142 1.077 1.229 1.944 1.887 2.343 2.427 1.641 1.196 1.102 1.071 c <: 3.00E-06 0.117 0.110 0.130 0.136 0.139 0.192 0.235 0.372 0.618 1.023 0.990 1.136 1.857 1.862 2.213 2.380 1.689 1.204 1.102 1.060 2.00E-06 0.108 0.101 0.120 0.126 0.129 0.178 0.219 0.345 0.573 0.941 0.915 1.040 1.763 1.807 2.113 2.326 1.735 1.212 1.103 1.052 1.00E-06 0.092 0.087 0.104 0.110 0.113 0.157 0.195 0.304 0.497 0.813 0.781 0.886 1.579 1.685 1.975 2.237 1.816 1.231 1.102 1.041 7.50E-07 0.087 0.081 0.098 0.103 0.106 0.149 0.186 0.289 0.467 0.774 0.741 0.840 1.482 1.583 1.890 2.171 1.820 1.240 1.102 1.039 5.00E-07 0.079 0.074 0.091 0.096 0.098 0.139 0.174 0.269 0.430 0.708 0.686 0.770 1.323 1.489 1.794 2.071 1.831 1.260 1.103 1.037 3.00E-07 0.070 0.067 0.082 0.087 0.090 0.127 0.160 0.245 0.387 0.638 0.639 0.686 1.183 1.366 1.640 1.960 1.836 1.286 1.105 1.038 2.00E-07 0.058 0.062 0.076 0.081 0.083 0.118 0.150 0.228 0.356 0.591 0.585 0.638 1.067 1.303 1.547 1.844 1.826 1.310 1.108 1.039 1.00E-07 0.045 0.054 0.067 0.072 0.074 0.105 0.135 0.201 0.307 0.520 0.524 0.560 0.928 1.121 1.298 1.609 1.807 1.365 1.118 1.041 66 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.6-6: Total Logarithmic Standard Deviation of the 5% Damped Site Amplification for Base-Case Profile C2-EPRI Period [s] 0.01 0.02 0.03 0.04 0.05 0.08 0.10 0.15 0.20 0.30 0.40 0.50 0.75 1.00 1.50 2.00 3.00 5.00 7.50 10.00 Freauencv [Hzl 100.00 50.00 33.33 25.00 20.00 13.33 10.00 6.67 5.00 3.33 2.50 2.00 1.33 1.00 0.67 0.50 0.33 0.20 0.13 0.10 1.00E-02 0.294 0.292 0.266 0.280 0.266 0.273 0.255 0.245 0.347 0.483 0.336 0.323 0.148 0.150 0.132 0.132 0.074 0.047 0.044 0.034 7.52E-03 0.276 0.269 0.248 0.264 0.247 0.259 0.241 0.246 0.354 0.474 0.340 0.325 0.150 0.151 0.132 0.133 0.072 0.047 0.032 0.023 5.00E-03 0.252 0.239 0.226 0.244 0.218 0.244 0.225 0.251 0.368 0.461 0.349 0.329 0.152 0.152 0.133 0.134 0.072 0.037 0.033 0.037 3.00E-03 0.222 0.214 0.213 0.229 0.194 0.239 0.214 0.259 0.387 0.443 0.367 0.340 0.156 0.155 0.132 0.137 0.073 0.038 0.029 0.035 2.00E-03 0.205 0.204 0.212 0.226 0.188 0.241 0.212 0.268 0.403 0.429 0.376 0.350 0.161 0.158 0.129 0.140 0.072 0.036 0.029 0.037 1.00E-03 0.198 0.198 0.222 0.229 0.187 0.254 0.219 0.291 0.430 0.401 0.391 0.377 0.176 0.167 0.126 0.146 0.074 0.033 0.031 0.035 7.50E-04 0.196 0.200 0.230 0.231 0.190 0.262 0.224 0.303 0.443 0.391 0.397 0.390 0.187 0.172 0.125 0.150 0.076 0.032 0.031 0.035 >-5.00E-04 0.199 0.204 0.241 0.238 0.196 0.275 0.233 0.318 0.456 0.374 0.406 0.411 0.209 0.181 0.126 0.155 0.080 0.032 0.030 0.034 0 4.00E-04 0.202 0.209 0.248 0.241 0.201 0.282 0.238 0.325 0.462 0.374 0.411 0.425 0.224 0.188 0.127 0.158 0.082 0.033 0.030 0.034 c Q) 3.00E-04 0.207 0.215 0.259 0.249 0.208 0.293 0.245 0.332 0.467 0.376 0.417 0.440 0.246 0.200 0.130 0.161 0.085 0.033 0.030 0.034 ::J O" 2.00E-04 0.210 0.227 0.275 0.260 0.220 0.305 0.255 0.342 0.474 0.389 0.425 0.458 0.281 0.222 0.136 0.165 0.091 0.034 0.030 0.035 Q) ..... LL 1.00E-04 0.226 0.252 0.301 0.278 0.240 0.325 0.271 0.357 0.482 0.425 0.425 0.479 0.333 0.282 0.162 0.171 0.101 0.037 0.029 0.035 Q) 7.50E-05 0.233 0.261 0.311 0.284 0.246 0.332 0.276 0.365 0.487 0.442 0.425 0.488 0.348 0.310 0.176 0.173 0.106 0.039 0.029 0.035 0 c 5.00E-05 0.242 0.274 0.255 0.332 0.375 0.496 0.470 0.427 0.494 0.344 0.177 0.113 0.041 0.035 ca 0.321 0.291 0.282 0.368 0.206 0.029 "U Q) 3.00E-05 0.252 0.273 0.331 0.295 0.264 0.339 0.293 0.390 0.500 0.494 0.433 0.501 0.393 0.350 0.278 0.186 0.124 0.043 0.029 0.033 Q) 0 2.00E-05 0.259 0.281 0.342 0.301 0.271 0.346 0.303 0.399 0.502 0.505 0.432 0.517 0.407 0.358 0.316 0.201 0.135 0.045 0.029 0.030 x w 1.00E-05 0.269 0.294 0.360 0.311 0.282 0.356 0.320 0.414 0.509 0.517 0.463 0.527 0.472 0.363 0.339 0.250 0.158 0.051 0.029 0.025 cU 7.50E-06 0.272 0.297 0.366 0.315 0.286 0.359 0.327 0.420 0.511 0.522 0.479 0.536 0.478 0.355 0.349 0.275 0.169 0.053 0.029 0.023 ::J c 5.00E-06 0.277 0.303 0.377 0.321 0.292 0.364 0.336 0.428 0.517 0.532 0.503 0.560 0.500 0.387 0.350 0.281 0.185 0.058 0.030 0.025 c <: 3.00E-06 0.282 0.310 0.388 0.327 0.298 0.372 0.349 0.438 0.530 0.545 0.515 0.590 0.537 0.453 0.370 0.290 0.203 0.066 0.030 0.022 2.00E-06 0.286 0.315 0.398 0.332 0.304 0.376 0.360 0.448 0.539 0.559 0.519 0.602 0.561 0.476 0.392 0.303 0.223 0.073 0.031 0.020 1.00E-06 0.294 0.324 0.414 0.342 0.312 0.386 0.376 0.464 0.562 0.584 0.542 0.624 0.619 0.525 0.463 0.342 0.247 0.093 0.034 0.020 7.50E-07 0.296 0.328 0.421 0.346 0.315 0.390 0.384 0.470 0.570 0.592 0.552 0.633 0.629 0.521 0.464 0.353 0.239 0.107 0.035 0.020 5.00E-07 0.300 0.333 0.429 0.352 0.319 0.398 0.395 0.477 0.580 0.604 0.561 0.656 0.619 0.522 0.490 0.373 0.231 0.135 0.038 0.019 3.00E-07 0.326 0.339 0.440 0.359 0.324 0.405 0.409 0.487 0.591 0.611 0.583 0.631 0.643 0.518 0.521 0.434 0.232 0.164 0.044 0.020 2.00E-07 0.340 0.344 0.449 0.365 0.328 0.412 0.419 0.492 0.595 0.617 0.585 0.624 0.639 0.538 0.549 0.459 0.239 0.181 0.050 0.021 1.00E-07 0.294 0.352 0.464 0.375 0.335 0.426 0.437 0.501 0.605 0.645 0.600 0.606 0.658 0.555 0.506 0.487 0.269 0.215 0.069 0.025 67 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.6-7: Weighted Average Logarithmic Mean of the 5% Damped Site Amplification for Base-Case Profile C2-PEN Period [s] 0.01 0.02 0.03 0.04 0.05 0.08 0.10 0.15 0.20 0.30 0.40 0.50 0.75 1.00 1.50 2.00 3.00 5.00 7.50 10.00 Freauencv [Hzl 100.00 50.00 33.33 25.00 20.00 13.33 10.00 6.67 5.00 3.33 2.50 2.00 1.33 1.00 0.67 0.50 0.33 0.20 0.13 0.10 1.00E-02 1.037 0.888 0.907 0.896 0.863 1.057 1.138 1.684 3.031 3.137 1.584 1.894 2.236 2.406 2.689 1.974 1.452 1.235 1.174 1.147 7.52E-03 0.960 0.838 0.863 0.853 0.820 1.022 1.102 1.641 2.963 3.111 1.592 1.890 2.233 2.396 2.693 1.971 1.439 1.226 1.155 1.130 5.00E-03 0.892 0.784 0.812 0.799 0.765 0.953 1.032 1.566 2.844 3.052 1.598 1.883 2.227 2.380 2.689 1.965 1.432 1.207 1.137 1.117 3.00E-03 0.812 0.727 0.756 0.740 0.705 0.886 0.960 1.476 2.680 2.971 1.597 1.862 2.220 2.354 2.689 1.968 1.429 1.196 1.126 1.114 2.00E-03 0.736 0.681 0.712 0.694 0.660 0.829 0.900 1.398 2.535 2.905 1.603 1.847 2.212 2.334 2.689 1.980 1.426 1.190 1.124 1.114 1.00E-03 0.645 0.589 0.625 0.604 0.574 0.728 0.795 1.266 2.270 2.760 1.613 1.821 2.198 2.287 2.696 2.007 1.427 1.184 1.118 1.116 7.50E-04 0.602 0.554 0.590 0.571 0.544 0.691 0.756 1.208 2.153 2.696 1.616 1.814 2.192 2.268 2.699 2.021 1.428 1.182 1.117 1.117 >-5.00E-04 0.546 0.505 0.541 0.523 0.495 0.637 0.698 1.130 2.000 2.568 1.611 1.802 2.180 2.243 2.700 2.041 1.434 1.179 1.115 1.115 0 4.00E-04 0.516 0.482 0.516 0.499 0.473 0.609 0.671 1.089 1.917 2.509 1.605 1.794 2.175 2.225 2.705 2.053 1.437 1.178 1.114 1.115 c 3.00E-04 0.476 0.450 0.479 0.465 0.440 0.573 0.634 1.039 1.820 2.425 1.598 1.777 2.174 2.205 2.704 2.071 1.441 1.181 1.113 1.115 ::J O" 2.00E-04 0.417 0.403 0.426 0.421 0.400 0.526 0.585 0.966 1.687 2.310 1.583 1.744 2.173 2.175 2.708 2.095 1.449 1.179 1.111 1.115 Q) ..... LL 1.00E-04 0.342 0.334 0.358 0.356 0.340 0.456 0.514 0.844 1.460 2.108 1.541 1.686 2.169 2.137 2.705 2.141 1.465 1.177 1.109 1.114 7.50E-05 0.313 0.310 0.333 0.331 0.319 0.432 0.489 0.798 1.380 2.024 1.514 1.656 2.163 2.122 2.692 2.165 1.473 1.176 1.108 1.114 0 c 5.00E-05 0.277 0.305 0.397 0.451 0.739 1.264 1.904 1.464 2.150 2.098 2.667 2.200 1.486 1.176 1.106 1.110 ca 0.280 0.306 0.294 1.613 "U Q) 3.00E-05 0.247 0.238 0.272 0.273 0.266 0.360 0.412 0.669 1.140 1.766 1.398 1.546 2.106 2.062 2.624 2.239 1.504 1.177 1.105 1.103 0 2.00E-05 0.223 0.214 0.247 0.249 0.243 0.331 0.383 0.620 1.053 1.665 1.340 1.484 2.051 2.024 2.600 2.274 1.521 1.179 1.104 1.092 x w 1.00E-05 0.184 0.178 0.209 0.213 0.208 0.290 0.340 0.545 0.921 1.499 1.245 1.358 1.955 1.886 2.511 2.336 1.562 1.183 1.102 1.071 cU 7.50E-06 0.171 0.167 0.197 0.201 0.197 0.274 0.323 0.518 0.870 1.435 1.207 1.313 1.915 1.843 2.419 2.360 1.584 1.186 1.101 1.063 ::J c 5.00E-06 0.155 0.151 0.181 0.185 0.182 0.255 0.303 0.481 0.805 1.348 1.159 1.251 1.857 1.788 2.313 2.378 1.615 1.190 1.101 1.071 c <: 3.00E-06 0.137 0.135 0.163 0.167 0.164 0.232 0.278 0.438 0.730 1.231 1.097 1.183 1.782 1.718 2.191 2.358 1.661 1.198 1.101 1.059 2.00E-06 0.126 0.125 0.151 0.155 0.153 0.216 0.261 0.408 0.673 1.133 1.039 1.134 1.715 1.675 2.085 2.298 1.701 1.206 1.101 1.052 1.00E-06 0.109 0.107 0.132 0.136 0.134 0.192 0.235 0.361 0.586 0.984 0.936 1.026 1.596 1.567 1.911 2.191 1.768 1.225 1.100 1.041 7.50E-07 0.102 0.100 0.125 0.129 0.127 0.183 0.225 0.343 0.555 0.925 0.898 0.972 1.547 1.513 1.848 2.120 1.768 1.233 1.100 1.038 5.00E-07 0.093 0.093 0.116 0.120 0.118 0.171 0.211 0.319 0.515 0.847 0.847 0.904 1.462 1.446 1.759 2.038 1.780 1.252 1.100 1.037 3.00E-07 0.082 0.084 0.106 0.110 0.108 0.157 0.195 0.291 0.469 0.754 0.773 0.834 1.312 1.353 1.639 1.900 1.783 1.279 1.103 1.037 2.00E-07 0.068 0.078 0.099 0.103 0.101 0.147 0.184 0.271 0.435 0.691 0.714 0.773 1.215 1.287 1.506 1.829 1.786 1.301 1.105 1.038 1.00E-07 0.053 0.069 0.089 0.091 0.090 0.132 0.166 0.240 0.383 0.607 0.626 0.680 1.069 1.152 1.307 1.637 1.752 1.355 1.114 1.040 68 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.6-8: Total Logarithmic Standard Deviation of the 5% Damped Site Amplification for Base-Case Profile C2-PEN Period [s] 0.01 0.02 0.03 0.04 0.05 0.08 0.10 0.15 0.20 0.30 0.40 0.50 0.75 1.00 1.50 2.00 3.00 5.00 7.50 10.00 Freauencv [Hzl 100.00 50.00 33.33 25.00 20.00 13.33 10.00 6.67 5.00 3.33 2.50 2.00 1.33 1.00 0.67 0.50 0.33 0.20 0.13 0.10 1.00E-02 0.281 0.284 0.262 0.281 0.259 0.274 0.252 0.241 0.345 0.502 0.344 0.324 0.152 0.153 0.136 0.134 0.076 0.048 0.045 0.035 7.52E-03 0.266 0.265 0.247 0.268 0.242 0.263 0.241 0.243 0.353 0.494 0.349 0.327 0.153 0.153 0.136 0.135 0.073 0.048 0.033 0.024 5.00E-03 0.245 0.240 0.230 0.251 0.215 0.252 0.228 0.250 0.369 0.481 0.357 0.330 0.155 0.154 0.135 0.136 0.073 0.038 0.033 0.037 3.00E-03 0.220 0.220 0.221 0.240 0.193 0.249 0.220 0.259 0.389 0.465 0.374 0.340 0.158 0.157 0.134 0.138 0.074 0.039 0.030 0.035 2.00E-03 0.206 0.212 0.223 0.238 0.188 0.251 0.220 0.269 0.405 0.453 0.385 0.348 0.163 0.160 0.133 0.142 0.073 0.037 0.029 0.037 1.00E-03 0.201 0.208 0.235 0.242 0.188 0.263 0.228 0.289 0.428 0.433 0.404 0.368 0.175 0.167 0.130 0.148 0.075 0.034 0.032 0.036 7.50E-04 0.200 0.208 0.242 0.244 0.191 0.269 0.233 0.299 0.440 0.425 0.410 0.379 0.182 0.171 0.129 0.152 0.077 0.033 0.032 0.036 >-5.00E-04 0.203 0.212 0.253 0.250 0.196 0.280 0.242 0.314 0.453 0.408 0.416 0.396 0.195 0.178 0.130 0.157 0.080 0.033 0.030 0.035 0 4.00E-04 0.206 0.214 0.259 0.254 0.200 0.287 0.246 0.322 0.461 0.405 0.419 0.407 0.204 0.182 0.131 0.159 0.082 0.033 0.030 0.035 c Q) 3.00E-04 0.211 0.219 0.270 0.261 0.206 0.297 0.253 0.331 0.469 0.401 0.423 0.419 0.219 0.189 0.132 0.162 0.085 0.034 0.030 0.035 ::J O" 2.00E-04 0.213 0.228 0.286 0.272 0.216 0.311 0.263 0.346 0.481 0.402 0.433 0.432 0.247 0.201 0.137 0.166 0.090 0.035 0.030 0.035 Q) ..... LL 1.00E-04 0.228 0.251 0.312 0.293 0.235 0.335 0.279 0.364 0.495 0.413 0.450 0.460 0.295 0.238 0.153 0.170 0.099 0.037 0.030 0.036 Q) 7.50E-05 0.235 0.261 0.322 0.301 0.242 0.345 0.285 0.373 0.500 0.424 0.454 0.471 0.312 0.260 0.163 0.172 0.103 0.038 0.030 0.036 0 c 5.00E-05 0.244 0.274 0.310 0.252 0.350 0.508 0.445 0.458 0.482 0.181 0.173 0.110 0.040 0.035 ca 0.333 0.292 0.384 0.343 0.291 0.030 "U Q) 3.00E-05 0.255 0.276 0.345 0.319 0.264 0.363 0.304 0.398 0.515 0.472 0.459 0.496 0.367 0.328 0.220 0.175 0.119 0.043 0.029 0.034 Q) 0 2.00E-05 0.263 0.286 0.359 0.328 0.273 0.374 0.313 0.406 0.520 0.492 0.459 0.506 0.379 0.354 0.270 0.182 0.128 0.045 0.029 0.031 x w 1.00E-05 0.276 0.304 0.382 0.344 0.286 0.388 0.328 0.422 0.528 0.524 0.471 0.524 0.411 0.338 0.342 0.216 0.150 0.049 0.029 0.025 cU 7.50E-06 0.281 0.310 0.390 0.349 0.291 0.392 0.334 0.429 0.531 0.537 0.480 0.532 0.426 0.346 0.340 0.244 0.161 0.052 0.029 0.024 ::J c 5.00E-06 0.287 0.318 0.404 0.356 0.298 0.398 0.344 0.437 0.536 0.559 0.499 0.545 0.454 0.360 0.350 0.274 0.175 0.056 0.030 0.025 c <: 3.00E-06 0.293 0.328 0.418 0.365 0.306 0.407 0.357 0.447 0.544 0.581 0.515 0.569 0.488 0.383 0.372 0.301 0.194 0.063 0.030 0.022 2.00E-06 0.298 0.335 0.431 0.371 0.312 0.411 0.367 0.455 0.547 0.595 0.526 0.593 0.515 0.415 0.391 0.306 0.209 0.070 0.031 0.020 1.00E-06 0.307 0.348 0.452 0.383 0.322 0.420 0.385 0.468 0.558 0.606 0.563 0.617 0.555 0.452 0.429 0.343 0.231 0.090 0.033 0.020 7.50E-07 0.310 0.354 0.461 0.388 0.326 0.424 0.392 0.473 0.564 0.606 0.577 0.616 0.571 0.456 0.449 0.351 0.213 0.103 0.034 0.019 5.00E-07 0.314 0.362 0.472 0.394 0.331 0.431 0.404 0.479 0.571 0.608 0.597 0.634 0.596 0.472 0.481 0.374 0.219 0.131 0.037 0.018 3.00E-07 0.342 0.371 0.487 0.403 0.337 0.438 0.419 0.489 0.579 0.612 0.599 0.656 0.609 0.492 0.513 0.404 0.218 0.162 0.043 0.019 2.00E-07 0.364 0.379 0.499 0.409 0.343 0.445 0.429 0.497 0.587 0.619 0.596 0.660 0.624 0.489 0.510 0.445 0.236 0.178 0.049 0.020 1.00E-07 0.321 0.392 0.519 0.422 0.351 0.457 0.447 0.505 0.600 0.632 0.597 0.666 0.638 0.497 0.496 0.483 0.268 0.215 0.067 0.023 69 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 2 Realizations * * * *
• Arithmetic Mean 1.8 -Logarithmic Mean Profile: 1.6 Period c1 -epri 0.100 sec 1.00E-4 s 1.4 c 0 :;::; QI 1.2 Qi 0.. Cl>_ 0.8 0.. E 0.6 0.4 0.2 AEF: Event 1 o-------0.1 10 Frequency [Hz) Figure 2.3.6-1: The Computed Surface 5% Damped Acceleration Response Spectrum (Profile: C1-EPRI, CMS Period: 0.1 sec, AFE: 1E-4, and Event: 1) 70 of 136 100 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 7.0 6.0 5.0 c Ill u i;::: a 4.o E <( ii) i:i 3.0 E C'll c ;!!. I() 2.0 1.0 0.0 0.1 Profile: c1 -epri Realizations Period 0.100 sec AEF 1.00E-4 *****Arithmetic Mean Event: 1 -Logarithmic Mean 10 Frequency [Hz) Figure 2.3.6-2: The Individual Realizations and Arithmetic Site Amplification (Profile: C1-EPRI, CMS Period: 0.1 sec, AFE: 1E-4, and Event: 1) 71 of 136 100 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure c 0 4.0 3.5 3.0 :; 2.5 u !E c.. E <( 2.0 ii) "C E 1.5 C'll c 0.5 0.0 Profile: Period AEF Event 0.1 c1 -epri 0.100 sec 1.00E-4 1 Frequency [Hz) 10 *******Arithmetic Mean --Logarithmic Mean ---*+/-a_ln Variation 100 Figure 2.3.6-3: The Arithmetic, Logarithmic and +/-a1n Variation of the Site Amplification (Profile: C1 -EPRI, CMS Period: 0.1 sec, AFE: 1 E-4, and Event: 1) 72 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 0.60 0.50 0.10 0.00 0.1 Profile: c1-epri Period: 0.100 sec AEF: 1.00E-4 Event: 1 10 Frequency [Hz) Figure 2.3.6-4: The Logarithmic Standard Deviation of the Site Amplification (Profile: C1-EPRI, CMS Period: 0.1 sec, AFE: 1E-4, and Event: 1) 73 of 136 100 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 1.0 0.8 0.5 en -Event 0 -Event 1 Event2 -Event 3 Profile: Period: Frequency: . ---c1-epri 0.100 sec 10.000 Hz ---------------------.... -.... .... --------0.3 0.0 --1.00E-07 1.00E-06 1.00E-05 1.00E-04 Annual Exceedence Frequency (1fyear] ---1.00E-03 Figure 2.3.6-5: The Weight Factors for the Four Events at the Various MAFE (Profile: C1-EPRI, CMS Period: 0.1 sec) The magnitude and distance of each event varies with MAFE 74 of 136 _. -1.00E-02 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure c 0 :;::; Ill u !E c.. 2.5 2.0 E 1.5 <( .SI (ii c :ll :E .!:! Qi 1.0 E .s *i:::: <( 0.5 -Event 0 -Event 1 Event2 -Event 3 -Weighted Average Profile: Period: Frequency: c1-epri 0.100 sec 10000 Hz ---_,,,_.-___ ,,,,._ ---0.0 1 OOE-07 1.00E-06 1.00E-05 1.00E-04 Annual Exceedence Frequency (1fyear] / / 1.00E-03 / I I I I Figure 2.3.6-6: The Weighted Average of the Logarithmic Site Amplification for the Four Events at the Various MAFE (Profile: C1-EPRI, CMS Period: 0.1 sec) 75 of 136 I I I I 1.00E-02 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure c 0 :;::; Cll u Q. E c( ii) c Cll Q) :E u .E -*c: Cll CJ) 0 ....I 2.5 -Event 0 -Event 1 Event2 -Event 3 2.0 -Weighted Average Profile: c1-epri Period: 0.100 sec Frequency: 10.000 Hz 1.5 1.0 0.5 ---___ ..... __ _ *---------0.0 1.00E-07 1.00E-06 I I I I I I I I / 1.00E-05 1.00E-04 1.00E-03 1 OOE-02 Annual Exceedence Frequency [1/year) Figure 2.3.6-7: The Total Logarithmic Standard Deviation for the Four Events at the Various MAFE (Profile: C1-EPRI, CMS Period: 0.1 sec) 76 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 3.0 ..................................................................................... . ci. E <t 2.5 (I) ...... iJ) c Ctl (IJ :a .!::::! 2.0 E ..c ...... *;:: Ctl OI 3 . ,'i* L <:-r-4 LL UJ <t c ro (IJ 1.5 Ctl ,_ ./\\***********. ... \* .... ...... 10-5 :a (IJ "C (IJ ...... \'. -5' 1.0 '\ \. . ..... * .... .... \ ... '\. ' 0.5 .................................... . . . \::t* .............. .. .. -.................... ............ .................... io-10° io 102 Frequency [Hz] Figure 2.3.6-8: Line Plots of the Weighted Average Logarithmic Site Amplification for the C1-EPRI Profile 77 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure ci_ E <l: QI ...... Vl CV ..c. ...... .._ 0 c:: 0 tlJ *:; CV Q -0 ,_ tlJ -0 c tlJ ...... Vl E ..c. ...... tlJ Ol 0 ....J -;o ,..., i2 0.7 10-3 0.6 0.5 10*4 L >--r-4 0.4 LL UJ <l: c: ro v 10-5 :a 0.3 0.2 10-6 0.1 .................... ............ ...................... 10-10° 10 102 Frequency [Hz] Figure 2.3.6-9: Line Plot of the Total Standard Deviation of the Site Amplification for the C1-EPRI Profile 78 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 100.00 Hz 50.00 Hz ******** ... .. .. ........... ----1 /= 33.33 Hz 25.00 Hz ........... ----1 I= 20.00 Hz 13.33 Hz ** ... ........... ----1 /= 10.00 Hz 10*1 .....__.__ __ _.._ ____ ....._ __ ........._ ........ 5.00 Hz 10-1 .....__.__....____._. .......... __ ........... .-..........____.__ .................. 10-2 10-1 10° 101 10*2 10-1 10° Input PSA at /(g] Input PSA at I [g] Figure 2.3.6-10: Logarithmic with +/-1-a1n Variation of the C1-EPRI Site Amplification at Frequencies from 100.00 to 3.33 Hz 79 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 2.50 Hz 2.00 Hz 1.33 Hz ........ 1.00 Hz --10*1 .....__ ___ _....... ____ ...._ ___ __. I 0.67 Hz 0-50 Hz 10*1 .....__._ __ ......._ __ __.__......__..___.............., 0.33 Hz ........ 0.20 Hz -,_ --->--10*1 .....___._ __ _....... ____ ...._ ___ __. I 0.13 Hz 0.10 Hz a. 100 ------------QI ..,,, ill 10* l .....__._....___......._ __ __.__.__._......_ ___ ..___.............., 10*2 10*1 10° 101 10*2 Input PSA at I [g] 10*1 10° Input PSA at /(g] Figure 2.3.6-11: Logarithmic with +/-1 *a1n Variation of the C1 -EPRI Site Amplification at Frequencies from 2.50 to 0.10 Hz 80 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure ci E <( QI ..... ii) ci E <( QI ...., Vi ci E <( QI ..... ii) ci E <( QI ..... ii) ci E <( QI ..... ii) 100.00 Hz 100 10*1 ........... ---11 f= 33.33 Hz 10° -***** ..... 10*1 ........... ---11 f= 20.00 Hz 100 ****** .... 10*1 *********** ..... **---........... ---11 f= 10.00 Hz 10° -**-... **-... ****** ................ 10*1 5.00 Hz 100 10-1 10-2 10-1 10° Input PSA at I [g] 50.00 Hz ********** .. 25.00 Hz 13.33 Hz ********* .... -I 3.33 Hz 10-1 10° Input PSA at /(g] Figure 2.3.6-12: The Logarithmic Mean from the C1-EPRI (red line), C1-PEN (orange line), C2-EPRI (green line), and C2-PEN (blue line) Profiles at Frequencies from 100.00 to 3.33 Hz 81 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 2.so Hz 1.33 Hz -10*1 .....__ ___ _.._ ____ .......__ ___ _..... 0.67 Hz 0.33 Hz -10*1 .....__ ___ _.._ ____ .......__ ___ _..... 0.13 Hz a. 100 Q) ..,,, ill 1.00 Hz -I 0-50 Hz 0.20 Hz -I 0.10 Hz 10*1 .....__.__....____._. .......... __ ........... .-..........____._ _ _.... ........ 10*2 10*1 10° 101 10*2 10*1 10° Input PSA at /(g] Input PSA at I [g] Figure 2.3.6-13: The Logarithmic Mean from the C1-EPRI (red line), C1-PEN (orange line), C2-EPRI (green line), and C2-PEN (blue line) Profiles at Frequencies from 2.50 to 0.10 Hz 82 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 2.3. 7 Control Point Seismic Hazard Curves The procedure to develop probabilistic site-specific control point hazard curves used in the present analysis follows the methodology described in McGuire et al. (2001) and Bazzurro and Cornell (2004). This procedure (referred to as "Approach 3") computes a site-specific control point hazard curve for a broad range of spectral accelerations, given the site-specific baserock hazard curve (Section 2.2.2), and site-specific estimates of soil or soft-rock response (i.e., median amplification factors) and associated uncertainties {i.e., sigma in natural log units), presented in the previous section. The input base rock hazard curves are provided for a suite of 20 spectral frequencies which span the frequency range of 100 -0.1 Hz. Site response results are provided for the two base case soil profiles and two sets of soil damping ratio and shear modulus reduction curves, described earlier in this report. Given these input baserock hazard curves and the resulting site response analyses, control point hazard curves are developed using Approach 3 at each of the 20 spectral frequencies for the mean and five fractile levels (i.e., 5th, 16th, soth, a4th, and 95th percentiles), based on the individual combinations of the two soil profiles and two soil curves. Given the assigned weights of 0.67 for Profile C1 and 0.33 for Profile C2 and equal weights for the two sets of soil curves, a weighted average control point hazard curve is computed. The mean and fractile level control point hazard curves for seven selected spectral frequencies of 100 Hz (PGA), 25 Hz, 1 O Hz, 5 Hz, 2.5 Hz, 1 Hz, and 0.5 Hz for the CGS site are shown in Figures 2.3.7-1through2.3.7-7. Tabulated values of these control point hazard curves are provided in Tables 2.3.7-1 through 2.3.7-7. 83 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.7-1: The 5% Damped SA at 100 Hz (PGA) Control Point Hazard Curves for the CGS Site PGA Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile [g] AFE AFE AFE AFE AFE AFE 0.000100 9.362E-02 6.169E-02 7.082E-02 8.713E-02 1.122E-01 1.515E-01 0.000113 9.310E-02 6.132E-02 7.039E-02 8.670E-02 1.117E-01 1.503E-01 0.000128 9.245E-02 6.085E-02 6.986E-02 8.614E-02 1.110E-01 1.488E-01 0.000145 9.169E-02 6.031 E-02 6.924E-02 8.550E-02 1.101E-01 1.470E-01 0.000164 9.087E-02 5.973E-02 6.857E-02 8.481 E-02 1.093E-01 1.451 E-01 0.000185 9.002E-02 5.912E-02 6.788E-02 8.409E-02 1.083E-01 1.432E-01 0.000210 8.916E-02 5.851 E-02 6.717E-02 8.336E-02 1.074E-01 1.412E-01 0.000237 8.830E-02 5.789E-02 6.646E-02 8.263E-02 1.064E-01 1.392E-01 0.000268 8.744E-02 5.727E-02 6.576E-02 8.190E-02 1.055E-01 1.373E-01 0.000303 8.657E-02 5.665E-02 6.505E-02 8.117E-02 1.046E-01 1.353E-01 0.000343 8.569E-02 5.600E-02 6.432E-02 8.041 E-02 1.036E-01 1.334E-01 0.000388 8.475E-02 5.528E-02 6.352E-02 7.962E-02 1.026E-01 1.314E-01 0.000439 8.372E-02 5.444E-02 6.263E-02 7.875E-02 1.016E-01 1.294E-01 0.000497 8.255E-02 5.341 E-02 6.157E-02 7.774E-02 1.004E-01 1.272E-01 0.000562 8.117E-02 5.214E-02 6.029E-02 7.658E-02 9.901 E-02 1.249E-01 0.000636 7.958E-02 5.061 E-02 5.878E-02 7.520E-02 9.750E-02 1.224E-01 0.000719 7.777E-02 4.884E-02 5.702E-02 7.362E-02 9.580E-02 1.198E-01 0.000813 7.575E-02 4.684E-02 5.504E-02 7.180E-02 9.393E-02 1.171 E-01 0.000920 7.355E-02 4.466E-02 5.286E-02 6.975E-02 9.192E-02 1.143E-01 0.001041 7.116E-02 4.233E-02 5.047E-02 6.743E-02 8.974E-02 1.114E-01 0.001177 6.860E-02 3.987E-02 4.789E-02 6.483E-02 8.743E-02 1.085E-01 0.001332 6.589E-02 3.732E-02 4.517E-02 6.199E-02 8.499E-02 1.056E-01 0.001507 6.308E-02 3.473E-02 4.236E-02 5.896E-02 8.246E-02 1.028E-01 0.001704 6.023E-02 3.217E-02 3.954E-02 5.585E-02 7.987E-02 9.996E-02 0.001928 5.739E-02 2.970E-02 3.678E-02 5.273E-02 7.726E-02 9.714E-02 0.002181 5.459E-02 2.734E-02 3.412E-02 4.967E-02 7.465E-02 9.436E-02 0.002467 5.183E-02 2.51 OE-02 3.156E-02 4.665E-02 7.200E-02 9.156E-02 0.002791 4.907E-02 2.296E-02 2.908E-02 4.365E-02 6.927E-02 8.870E-02 0.003157 4.627E-02 2.089E-02 2.666E-02 4.063E-02 6.639E-02 8.574E-02 0.003571 4.341 E-02 1.889E-02 2.428E-02 3.757E-02 6.336E-02 8.265E-02 0.004040 4.052E-02 1.695E-02 2.195E-02 3.449E-02 6.019E-02 7.943E-02 0.004570 3.764E-02 1.511 E-02 1.970E-02 3.144E-02 5.692E-02 7.613E-02 0.005170 3.482E-02 1.339E-02 1.758E-02 2.850E-02 5.364E-02 7.281 E-02 0.005848 3.212E-02 1.181E-02 1.562E-02 2.574E-02 5.044E-02 6.953E-02 0.006615 2.957E-02 1.040E-02 1.384E-02 2.318E-02 4.733E-02 6.632E-02 0.007483 2.719E-02 9.127E-03 1.224E-02 2.083E-02 4.433E-02 6.316E-02 0.008465 2.495E-02 7.995E-03 1.080E-02 1.869E-02 4.140E-02 6.001 E-02 0.009576 2.282E-02 6.982E-03 9.503E-03 1.671 E-02 3.850E-02 5.682E-02 0.010833 2.079E-02 6.068E-03 8.330E-03 1.488E-02 3.557E-02 5.352E-02 0.012254 1.885E-02 5.243E-03 7.261 E-03 1.317E-02 3.262E-02 5.011 E-02 84 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure PGA Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile [g] AFE AFE AFE AFE AFE AFE 0.013862 1.699E-02 4.497E-03 6.290E-03 1.159E-02 2.965E-02 4.661 E-02 0.015681 1.521 E-02 3.829E-03 5.413E-03 1.013E-02 2.674E-02 4.307E-02 0.017739 1.355E-02 3.235E-03 4.627E-03 8.788E-03 2.392E-02 3.956E-02 0.020066 1.200E-02 2.712E-03 3.927E-03 7.576E-03 2.125E-02 3.613E-02 0.022699 1.055E-02 2.253E-03 3.305E-03 6.480E-03 1.873E-02 3.278E-02 0.025678 9.201 E-03 1.852E-03 2.754E-03 5.490E-03 1.638E-02 2.952E-02 0.029047 7.957E-03 1.504E-03 2.268E-03 4.601 E-03 1.419E-02 2.633E-02 0.032859 6.814E-03 1.205E-03 1.843E-03 3.810E-03 1.218E-02 2.324E-02 0.037170 5.780E-03 9.516E-04 1.478E-03 3.118E-03 1.035E-02 2.028E-02 0.042048 4.855E-03 7.400E-04 1.168E-03 2.520E-03 8.712E-03 1.749E-02 0.047565 4.038E-03 5.657E-04 9.090E-04 2.012E-03 7.260E-03 1.492E-02 0.053806 3.325E-03 4.238E-04 6.954E-04 1.587E-03 5.991 E-03 1.259E-02 0.060867 2.712E-03 3.101 E-04 5.212E-04 1.234E-03 4.896E-03 1.052E-02 0.068853 2.192E-03 2.208E-04 3.820E-04 9.473E-04 3.968E-03 8.725E-03 0.077888 1.759E-03 1.526E-04 2.733E-04 7.161 E-04 3.194E-03 7.188E-03 0.088108 1.403E-03 1.022E-04 1.904E-04 5.328E-04 2.556E-03 5.888E-03 0.099670 1.109E-03 6.621 E-05 1.290E-04 3.889E-04 2.029E-03 4.789E-03 0.112748 8.667E-04 4.136E-05 8.472E-05 2.774E-04 1.593E-03 3.853E-03 0.127542 6.667E-04 2.481 E-05 5.365E-05 1.919E-04 1.229E-03 3.055E-03 0.144278 5.020E-04 1.421 E-05 3.251 E-05 1.277E-04 9.250E-04 2.373E-03 0.163210 3.680E-04 7.699E-06 1.867E-05 8.093E-05 6.736E-04 1.796E-03 0.184625 2.616E-04 3.907E-06 1.007E-05 4.843E-05 4.711 E-04 1.319E-03 0.208851 1.798E-04 1.841 E-06 5.064E-06 2.720E-05 3.147E-04 9.369E-04 0.236256 1.196E-04 8.003E-07 2.361 E-06 1.430E-05 2.004E-04 6.430E-04 0.267257 7.693E-05 3.204E-07 1.021 E-06 7.045E-06 1.215E-04 4.256E-04 0.302325 4.785E-05 1.185E-07 4.106E-07 3.262E-06 7.000E-05 2.709E-04 0.341995 2.869E-05 4.074E-08 1.545E-07 1.425E-06 3.830E-05 1.649E-04 0.386871 1.650E-05 1.312E-08 5.471 E-08 5.875E-07 1.983E-05 9.554E-05 0.437634 9.059E-06 3.974E-09 1.825E-08 2.285E-07 9.677E-06 5.234E-05 0.495059 4.720E-06 1.132E-09 5.726E-09 8.356E-08 4.436E-06 2.699E-05 0.560020 2.325E-06 3.023E-10 1.683E-09 2.862E-08 1.904E-06 1.304E-05 0.633503 1.079E-06 7.523E-11 4.616E-10 9.152E-09 7.639E-07 5.897E-06 0.716629 4.717E-07 1.738E-11 1.176E-10 2.728E-09 2.859E-07 2.489E-06 0.810663 1.941 E-07 3.712E-12 2.778E-11 7.569E-10 9.967E-08 9.797E-07 0.917036 7.559E-08 7.313E-13 6.078E-12 1.956E-10 3.234E-08 3.599E-07 1.037366 2.809E-08 1.330E-13 1.233E-12 4.715E-11 9.769E-09 1.238E-07 1.173485 1.011 E-08 2.237E-14 2.325E-13 1.061 E-11 2.752E-09 4.022E-08 1.327466 3.585E-09 3.488E-15 4.085E-14 2.236E-12 7.266E-10 1.249E-08 1.501652 1.269E-09 5.062E-16 6.709E-15 4.426E-13 1.812E-10 3.766E-09 1.698694 4.487E-10 6.861 E-17 1.036E-15 8.282E-14 4.321E-11 1.122E-09 1.921589 1.562E-10 8.744E-18 1.515E-16 1.478E-14 1.000E-11 3.322E-10 2.173734 5.225E-11 1.056E-18 2.119E-17 2.544E-15 2.279E-12 9.717E-11 85 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure PGA Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile [g] AFE AFE AFE AFE AFE AFE 2.458964 1.639E-11 1.223E-19 2.868E-18 4.274E-16 5.148E-13 2.753E-11 2.781622 4.718E-12 1.377E-20 3.796E-19 7.071 E-17 1.144E-13 7.373E-12 3.146617 1.228E-12 1.527E-21 4.951 E-20 1.157E-17 2.460E-14 1.824E-12 3.559503 2.857E-13 1.675E-22 6.368E-21 1.864E-18 4.998E-15 4.093E-13 4.026569 5.893E-14 1.818E-23 8.045E-22 2.915E-19 9.383E-16 8.238E-14 4.554923 1.074E-14 1.942E-24 9.907E-23 4.347E-20 1.602E-16 1.475E-14 5.152606 1.727E-15 2.020E-25 1.179E-23 6.070E-21 2.460E-17 2.339E-15 5.828714 2.453E-16 2.050E-26 1.344E-24 7.830E-22 3.384E-18 3.290E-16 6.593533 3.093E-17 1.987E-27 1.451 E-25 9.260E-23 4.173E-19 4.118E-17 7.458715 3.488E-18 1.866E-28 1.482E-26 1.003E-23 4.635E-20 4.622E-18 8.437425 3.554E-19 1.736E-29 1.441 E-27 1.000E-24 4.676E-21 4.690E-19 9.544557 3.309E-20 1.517E-30 1.308E-28 9.210E-26 4.327E-22 4.355E-20 10.796952 2.855E-21 1.825E-31 1.330E-29 8.312E-27 3.749E-23 3.754E-21 12.213694 2.302E-22 O.OOOE+OO 3.660E-31 5.048E-28 2.860E-24 2.998E-22 13.816336 1.768E-23 O.OOOE+OO 2.791 E-32 3.847E-29 2.185E-25 2.298E-23 15.629272 1.286E-24 O.OOOE+OO 1.998E-33 2.750E-30 1.571 E-26 1.664E-24 17.680094 8.285E-26 O.OOOE+OO 1.220E-34 1.672E-31 9.715E-28 1.052E-25 20.000000 O.OOOE+OO O.OOOE+OO O.OOOE+OO O.OOOE+OO O.OOOE+OO O.OOOE+OO 86 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.7-2: The 5% damped SA at 25 Hz Control Point Hazard Curves for the CGS Site PSA Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile [g] AFE AFE AFE AFE AFE AFE 0.000100 9.330E-02 6.144E-02 7.058E-02 8.690E-02 1.119E-01 1.508E-01 0.000113 9.282E-02 6.103E-02 7.019E-02 8.650E-02 1.115E-01 1.496E-01 0.000128 9.224E-02 6.054E-02 6.972E-02 8.604E-02 1.109E-01 1.482E-01 0.000145 9.160E-02 6.000E-02 6.920E-02 8.552E-02 1.102E-01 1.467E-01 0.000164 9.091 E-02 5.941 E-02 6.863E-02 8.497E-02 1.095E-01 1.450E-01 0.000185 9.019E-02 5.882E-02 6.806E-02 8.439E-02 1.087E-01 1.433E-01 0.000210 8.947E-02 5.820E-02 6.747E-02 8.381 E-02 1.080E-01 1.415E-01 0.000237 8.874E-02 5.759E-02 6.687E-02 8.322E-02 1.072E-01 1.398E-01 0.000268 8.801 E-02 5.697E-02 6.628E-02 8.262E-02 1.064E-01 1.381 E-01 0.000303 8.726E-02 5.633E-02 6.565E-02 8.201 E-02 1.057E-01 1.364E-01 0.000343 8.647E-02 5.565E-02 6.498E-02 8.137E-02 1.049E-01 1.346E-01 0.000388 8.562E-02 5.489E-02 6.423E-02 8.066E-02 1.040E-01 1.328E-01 0.000439 8.466E-02 5.401 E-02 6.333E-02 7.986E-02 1.030E-01 1.309E-01 0.000497 8.355E-02 5.297E-02 6.227E-02 7.892E-02 1.020E-01 1.290E-01 0.000562 8.227E-02 5.174E-02 6.100E-02 7.784E-02 1.008E-01 1.269E-01 0.000636 8.082E-02 5.031 E-02 5.951 E-02 7.658E-02 9.947E-02 1.247E-01 0.000719 7.919E-02 4.867E-02 5.781 E-02 7.515E-02 9.798E-02 1.223E-01 0.000813 7.739E-02 4.684E-02 5.589E-02 7.352E-02 9.636E-02 1.198E-01 0.000920 7.540E-02 4.481 E-02 5.377E-02 7.169E-02 9.458E-02 1.173E-01 0.001041 7.324E-02 4.259E-02 5.146E-02 6.966E-02 9.265E-02 1.146E-01 0.001177 7.093E-02 4.021 E-02 4.898E-02 6.745E-02 9.059E-02 1.118E-01 0.001332 6.850E-02 3.774E-02 4.639E-02 6.509E-02 8.841 E-02 1.090E-01 0.001507 6.599E-02 3.522E-02 4.374E-02 6.262E-02 8.616E-02 1.061 E-01 0.001704 6.344E-02 3.272E-02 4.109E-02 6.009E-02 8.385E-02 1.032E-01 0.001928 6.088E-02 3.028E-02 3.849E-02 5.752E-02 8.149E-02 1.003E-01 0.002181 5.831 E-02 2.794E-02 3.594E-02 5.492E-02 7.907E-02 9.735E-02 0.002467 5.569E-02 2.568E-02 3.345E-02 5.225E-02 7.657E-02 9.434E-02 0.002791 5.302E-02 2.351 E-02 3.099E-02 4.948E-02 7.395E-02 9.121 E-02 0.003157 5.027E-02 2.141E-02 2.856E-02 4.660E-02 7.118E-02 8.795E-02 0.003571 4.745E-02 1.938E-02 2.617E-02 4.361 E-02 6.827E-02 8.455E-02 0.004040 4.459E-02 1.745E-02 2.383E-02 4.055E-02 6.525E-02 8.105E-02 0.004570 4.174E-02 1.562E-02 2.159E-02 3.751 E-02 6.217E-02 7.750E-02 0.005170 3.894E-02 1.392E-02 1.947E-02 3.454E-02 5.908E-02 7.395E-02 0.005848 3.625E-02 1.237E-02 1.749E-02 3.170E-02 5.604E-02 7.045E-02 0.006615 3.367E-02 1.096E-02 1.568E-02 2.900E-02 5.304E-02 6.699E-02 0.007483 3.120E-02 9.681 E-03 1.401 E-02 2.647E-02 5.009E-02 6.356E-02 0.008465 2.884E-02 8.533E-03 1.248E-02 2.409E-02 4.714E-02 6.011 E-02 0.009576 2.656E-02 7.494E-03 1.108E-02 2.183E-02 4.416E-02 5.662E-02 0.010833 2.435E-02 6.552E-03 9.785E-03 1.969E-02 4.114E-02 5.304E-02 0.012254 2.221 E-02 5.700E-03 8.595E-03 1.767E-02 3.81 OE-02 4.942E-02 87 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure PSA Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile [g] AFE AFE AFE AFE AFE AFE 0.013862 2.016E-02 4.934E-03 7.507E-03 1.577E-02 3.507E-02 4.579E-02 0.015681 1.822E-02 4.249E-03 6.521 E-03 1.400E-02 3.212E-02 4.221 E-02 0.017739 1.640E-02 3.643E-03 5.637E-03 1.237E-02 2.927E-02 3.875E-02 0.020066 1.471 E-02 3.11 OE-03 4.853E-03 1.089E-02 2.657E-02 3.544E-02 0.022699 1.314E-02 2.644E-03 4.160E-03 9.552E-03 2.402E-02 3.229E-02 0.025678 1.169E-02 2.234E-03 3.548E-03 8.337E-03 2.159E-02 2.927E-02 0.029047 1.034E-02 1.875E-03 3.006E-03 7.232E-03 1.928E-02 2.637E-02 0.032859 9.083E-03 1.559E-03 2.528E-03 6.230E-03 1.709E-02 2.360E-02 0.037170 7.918E-03 1.283E-03 2.107E-03 5.325E-03 1.503E-02 2.094E-02 0.042048 6.852E-03 1.043E-03 1.740E-03 4.517E-03 1.31 OE-02 1.845E-02 0.047565 5.887E-03 8.373E-04 1.424E-03 3.803E-03 1.134E-02 1.613E-02 0.053806 5.025E-03 6.640E-04 1.154E-03 3.181 E-03 9.748E-03 1.401 E-02 0.060867 4.263E-03 5.193E-04 9.257E-04 2.642E-03 8.331 E-03 1.210E-02 0.068853 3.595E-03 4.002E-04 7.344E-04 2.180E-03 7.081 E-03 1.040E-02 0.077888 3.013E-03 3.033E-04 5.752E-04 1.785E-03 5.986E-03 8.878E-03 0.088108 2.509E-03 2.256E-04 4.438E-04 1.447E-03 5.031 E-03 7.541 E-03 0.099670 2.074E-03 1.644E-04 3.367E-04 1.162E-03 4.202E-03 6.365E-03 0.112748 1.702E-03 1.171 E-04 2.507E-04 9.221 E-04 3.483E-03 5.335E-03 0.127542 1.384E-03 8.143E-05 1.828E-04 7.214E-04 2.863E-03 4.436E-03 0.144278 1.114E-03 5.51 SE-05 1.303E-04 5.549E-04 2.329E-03 3.654E-03 0.163210 8.860E-04 3.632E-05 9.053E-05 4.185E-04 1.870E-03 2.975E-03 0.184625 6.940E-04 2.322E-05 6.11 SE-05 3.083E-04 1.479E-03 2.389E-03 0.208851 5.343E-04 1.436E-05 4.002E-05 2.210E-04 1.150E-03 1.888E-03 0.236256 4.034E-04 8.579E-06 2.533E-05 1.539E-04 8.752E-04 1.464E-03 0.267257 2.980E-04 4.939E-06 1.547E-05 1.038E-04 6.515E-04 1.112E-03 0.302325 2.152E-04 2.733E-06 9.094E-06 6.777E-05 4.732E-04 8.250E-04 0.341995 1.516E-04 1.453E-06 5.148E-06 4.275E-05 3.347E-04 5.973E-04 0.386871 1.041 E-04 7.41 SE-07 2.805E-06 2.608E-05 2.302E-04 4.212E-04 0.437634 6.954E-05 3.636E-07 1.472E-06 1.538E-05 1.538E-04 2.889E-04 0.495059 4.521 E-05 1.714E-07 7.441 E-07 8.765E-06 9.961 E-05 1.926E-04 0.560020 2.857E-05 7.778E-08 3.631 E-07 4.829E-06 6.254E-05 1.246E-04 0.633503 1.753E-05 3.401 E-08 1.709E-07 2.570E-06 3.800E-05 7.823E-05 0.716629 1.045E-05 1.433E-08 7.756E-08 1.320E-06 2.235E-05 4.765E-05 0.810663 6.056E-06 5.816E-09 3.392E-08 6.537E-07 1.272E-05 2.818E-05 0.917036 3.416E-06 2.271 E-09 1.428E-08 3.122E-07 7.022E-06 1.621 E-05 1.037366 1.879E-06 8.519E-10 5.778E-09 1.439E-07 3.761 E-06 9.076E-06 1.173485 1.011 E-06 3.065E-10 2.246E-09 6.406E-08 1.961 E-06 4.963E-06 1.327466 5.337E-07 1.057E-10 8.396E-10 2.764E-08 9.974E-07 2.658E-06 1.501652 2.776E-07 3.499E-11 3.025E-10 1.160E-08 4.968E-07 1.399E-06 1.698694 1.427E-07 1 .113E-11 1.054E-10 4.751 E-09 2.430E-07 7.251 E-07 1.921589 7.284E-08 3.422E-12 3.575E-11 1.909E-09 1.171 E-07 3.717E-07 2.173734 3.700E-08 1.022E-12 1.184E-11 7.543E-10 5.579E-08 1.889E-07 88 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure PSA Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile [g] AFE AFE AFE AFE AFE AFE 2.458964 1.878E-08 2.981 E-13 3.856E-12 2.940E-10 2.635E-08 9.556E-08 2.781622 9.537E-09 8.557E-14 1.239E-12 1.133E-10 1.238E-08 4.822E-08 3.146617 4.855E-09 2.425E-14 3.932E-13 4.336E-11 5.796E-09 2.429E-08 3.559503 2.474E-09 6.804E-15 1.237E-13 1.651 E-11 2.713E-09 1.222E-08 4.026569 1.260E-09 1.891 E-15 3.862E-14 6.280E-12 1.270E-09 6.133E-09 4.554923 6.382E-10 5.214E-16 1.202E-14 2.398E-12 5.929E-10 3.060E-09 5.152606 3.202E-10 1.429E-16 3.743E-15 9.218E-13 2.758E-10 1.512E-09 5.828714 1.583E-10 3.897E-17 1.172E-15 3.568E-13 1.272E-10 7.366E-10 6.593533 7.671E-11 1.061 E-17 3.709E-16 1.392E-13 5.793E-11 3.520E-10 7.458715 3.627E-11 2.891 E-18 1.188E-16 5.445E-14 2.590E-11 1.642E-10 8.437425 1.666E-11 7.895E-19 3.862E-17 2.128E-14 1.133E-11 7.455E-11 9.544557 7.411 E-12 2.164E-19 1.270E-17 8.250E-15 4.818E-12 3.278E-11 10.796952 3.180E-12 5.961 E-20 4.205E-18 3.155E-15 1.989E-12 1.392E-11 12.213694 1.313E-12 1.649E-20 1.393E-18 1.183E-15 7.936E-13 5.698E-12 13.816336 5.210E-13 4.586E-21 4.585E-19 4.326E-16 3.052E-13 2.241 E-12 15.629272 1.981E-13 1.280E-21 1.489E-19 1.537E-16 1.130E-13 8.456E-13 17.680094 7.213E-14 3.578E-22 4.748E-20 5.281 E-17 4.017E-14 3.059E-13 20.000000 2.514E-14 9.991 E-23 1.477E-20 1.752E-17 1.370E-14 1.059E-13 89 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.7-3: The 5% Damped SA at 10 Hz Control Point Hazard Curves for the CGS Site PSA Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile [g] AFE AFE AFE AFE AFE AFE 0.000100 9.413E-02 6.189E-02 7.105E-02 8.743E-02 1.128E-01 1.525E-01 0.000113 9.383E-02 6.172E-02 7.086E-02 8.718E-02 1.124E-01 1.517E-01 0.000128 9.340E-02 6.148E-02 7.058E-02 8.684E-02 1.118E-01 1.505E-01 0.000145 9.286E-02 6.117E-02 7.023E-02 8.641 E-02 1.111E-01 1.490E-01 0.000164 9.222E-02 6.081 E-02 6.982E-02 8.590E-02 1.103E-01 1.473E-01 0.000185 9.154E-02 6.042E-02 6.937E-02 8.534E-02 1.094E-01 1.454E-01 0.000210 9.082E-02 6.001 E-02 6.890E-02 8.477E-02 1.085E-01 1.434E-01 0.000237 9.009E-02 5.959E-02 6.842E-02 8.418E-02 1.075E-01 1.414E-01 0.000268 8.936E-02 5.91 SE-02 6.794E-02 8.359E-02 1.066E-01 1.395E-01 0.000303 8.862E-02 5.876E-02 6.746E-02 8.300E-02 1.057E-01 1.375E-01 0.000343 8.789E-02 5.834E-02 6.698E-02 8.241 E-02 1.047E-01 1.356E-01 0.000388 8.715E-02 5.790E-02 6.649E-02 8.180E-02 1.038E-01 1.337E-01 0.000439 8.637E-02 5.742E-02 6.596E-02 8.117E-02 1.028E-01 1.316E-01 0.000497 8.551 E-02 5.687E-02 6.535E-02 8.047E-02 1.018E-01 1.296E-01 0.000562 8.453E-02 5.619E-02 6.463E-02 7.965E-02 1.008E-01 1.274E-01 0.000636 8.338E-02 5.534E-02 6.375E-02 7.868E-02 9.957E-02 1.249E-01 0.000719 8.203E-02 5.429E-02 6.268E-02 7.754E-02 9.828E-02 1.221 E-01 0.000813 8.047E-02 5.304E-02 6.142E-02 7.621 E-02 9.682E-02 1.192E-01 0.000920 7.872E-02 5.160E-02 5.996E-02 7.469E-02 9.519E-02 1.160E-01 0.001041 7.673E-02 4.994E-02 5.828E-02 7.294E-02 9.333E-02 1.127E-01 0.001177 7.451 E-02 4.804E-02 5.635E-02 7.095E-02 9.119E-02 1.093E-01 0.001332 7.202E-02 4.591 E-02 5.416E-02 6.869E-02 8.874E-02 1.057E-01 0.001507 6.931 E-02 4.358E-02 5.174E-02 6.618E-02 8.599E-02 1.020E-01 0.001704 6.642E-02 4.11 OE-02 4.916E-02 6.350E-02 8.300E-02 9.827E-02 0.001928 6.346E-02 3.858E-02 4.650E-02 6.072E-02 7.989E-02 9.455E-02 0.002181 6.049E-02 3.608E-02 4.385E-02 5.793E-02 7.673E-02 9.088E-02 0.002467 5.760E-02 3.368E-02 4.129E-02 5.519E-02 7.362E-02 8.730E-02 0.002791 5.480E-02 3.141 E-02 3.884E-02 5.255E-02 7.059E-02 8.384E-02 0.003157 5.213E-02 2.927E-02 3.651 E-02 5.003E-02 6.766E-02 8.0SOE-02 0.003571 4.957E-02 2.727E-02 3.432E-02 4.760E-02 6.484E-02 7.728E-02 0.004040 4.711 E-02 2.539E-02 3.224E-02 4.527E-02 6.209E-02 7.414E-02 0.004570 4.471 E-02 2.360E-02 3.024E-02 4.299E-02 5.939E-02 7.104E-02 0.005170 4.234E-02 2.187E-02 2.828E-02 4.072E-02 5.666E-02 6.791 E-02 0.005848 3.994E-02 2.01 SE-02 2.634E-02 3.842E-02 5.384E-02 6.467E-02 0.006615 3.748E-02 1.851 E-02 2.439E-02 3.606E-02 5.090E-02 6.130E-02 0.007483 3.498E-02 1.686E-02 2.245E-02 3.364E-02 4.784E-02 5.779E-02 0.008465 3.245E-02 1.525E-02 2.051 E-02 3.119E-02 4.471 E-02 5.419E-02 0.009576 2.996E-02 1.370E-02 1.863E-02 2.876E-02 4.156E-02 5.057E-02 0.010833 2.752E-02 1.225E-02 1.684E-02 2.637E-02 3.846E-02 4.700E-02 0.012254 2.518E-02 1.091 E-02 1.513E-02 2.405E-02 3.543E-02 4.352E-02 90 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure PSA Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile [g] AFE AFE AFE AFE AFE AFE 0.013862 2.294E-02 9.670E-03 1.354E-02 2.183E-02 3.251 E-02 4.017E-02 0.015681 2.082E-02 8.546E-03 1.206E-02 1.970E-02 2.972E-02 3.695E-02 0.017739 1.882E-02 7.528E-03 1.069E-02 1.770E-02 2.707E-02 3.389E-02 0.020066 1.696E-02 6.608E-03 9.438E-03 1.584E-02 2.456E-02 3.098E-02 0.022699 1.522E-02 5.778E-03 8.304E-03 1.411 E-02 2.220E-02 2.823E-02 0.025678 1.361 E-02 5.028E-03 7.273E-03 1.253E-02 1.998E-02 2.561 E-02 0.029047 1.210E-02 4.348E-03 6.339E-03 1.107E-02 1.788E-02 2.312E-02 0.032859 1.069E-02 3.732E-03 5.490E-03 9.727E-03 1.590E-02 2.074E-02 0.037170 9.392E-03 3.176E-03 4.722E-03 8.495E-03 1.405E-02 1.849E-02 0.042048 8.196E-03 2.680E-03 4.032E-03 7.372E-03 1.233E-02 1.638E-02 0.047565 7.105E-03 2.243E-03 3.418E-03 6.358E-03 1.076E-02 1.443E-02 0.053806 6.125E-03 1.862E-03 2.877E-03 5.450E-03 9.334E-03 1.264E-02 0.060867 5.252E-03 1.535E-03 2.404E-03 4.646E-03 8.064E-03 1.101 E-02 0.068853 4.482E-03 1.256E-03 1.997E-03 3.938E-03 6.939E-03 9.555E-03 0.077888 3.806E-03 1.021 E-03 1.646E-03 3.321 E-03 5.948E-03 8.249E-03 0.088108 3.215E-03 8.217E-04 1.347E-03 2.783E-03 5.077E-03 7.087E-03 0.099670 2.701 E-03 6.544E-04 1.093E-03 2.318E-03 4.311 E-03 6.058E-03 0.112748 2.255E-03 5.143E-04 8.779E-04 1.916E-03 3.639E-03 5.150E-03 0.127542 1.869E-03 3.982E-04 6.974E-04 1.571 E-03 3.051 E-03 4.351 E-03 0.144278 1.538E-03 3.033E-04 5.471 E-04 1.277E-03 2.539E-03 3.652E-03 0.163210 1.255E-03 2.268E-04 4.232E-04 1.027E-03 2.095E-03 3.041 E-03 0.184625 1.012E-03 1.661 E-04 3.219E-04 8.161 E-04 1.711 E-03 2.508E-03 0.208851 8.068E-04 1.190E-04 2.401 E-04 6.390E-04 1.381 E-03 2.046E-03 0.236256 6.339E-04 8.298E-05 1.751 E-04 4.918E-04 1.099E-03 1.647E-03 0.267257 4.900E-04 5.634E-05 1.247E-04 3.713E-04 8.607E-04 1.307E-03 0.302325 3.721 E-04 3.714E-05 8.641 E-05 2.743E-04 6.625E-04 1.022E-03 0.341995 2.774E-04 2.377E-05 5.830E-05 1.982E-04 5.004E-04 7.850E-04 0.386871 2.027E-04 1.476E-05 3.825E-05 1.398E-04 3.704E-04 5.920E-04 0.437634 1.451 E-04 8.904E-06 2.441 E-05 9.622E-05 2.683E-04 4.378E-04 0.495059 1.017E-04 5.221 E-06 1.515E-05 6.454E-05 1.899E-04 3.169E-04 0.560020 6.969E-05 2.977E-06 9.150E-06 4.219E-05 1.313E-04 2.244E-04 0.633503 4.668E-05 1.651 E-06 5.373E-06 2.685E-05 8.852E-05 1.552E-04 0.716629 3.055E-05 8.900E-07 3.067E-06 1.663E-05 5.820E-05 1.048E-04 0.810663 1.953E-05 4.664E-07 1.703E-06 1.002E-05 3.729E-05 6.906E-05 0.917036 1.220E-05 2.374E-07 9.187E-07 5.876E-06 2.330E-05 4.444E-05 1.037366 7.450E-06 1.174E-07 4.818E-07 3.353E-06 1.419E-05 2.792E-05 1.173485 4.449E-06 5.635E-08 2.459E-07 1.865E-06 8.440E-06 1.714E-05 1.327466 2.602E-06 2.632E-08 1.222E-07 1.011 E-06 4.901 E-06 1.029E-05 1.501652 1.492E-06 1.196E-08 5.922E-08 5.354E-07 2.782E-06 6.045E-06 1.698694 8.394E-07 5.301 E-09 2.SOOE-08 2.769E-07 1.545E-06 3.478E-06 1.921589 4.643E-07 2.294E-09 1.293E-08 1.401 E-07 8.404E-07 1.963E-06 2.173734 2.529E-07 9.703E-10 5.842E-09 6.933E-08 4.484E-07 1.089E-06 91 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure PSA Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile [g] AFE AFE AFE AFE AFE AFE 2.458964 1.359E-07 4.011E-10 2.580E-09 3.362E-08 2.350E-07 5.951 E-07 2.781622 7.225E-08 1.622E-10 1.115E-09 1.599E-08 1.213E-07 3.211 E-07 3.146617 3.813E-08 6.412E-11 4.722E-10 7.472E-09 6.181E-08 1.716E-07 3.559503 2.003E-08 2.482E-11 1.959E-10 3.437E-09 3.117E-08 9.102E-08 4.026569 1.050E-08 9.407E-12 7.978E-11 1.560E-09 1.561 E-08 4.806E-08 4.554923 5.498E-09 3.494E-12 3.195E-11 7.008E-10 7.783E-09 2.529E-08 5.152606 2.876E-09 1.274E-12 1.261 E-11 3.125E-10 3.867E-09 1.326E-08 5.828714 1.501 E-09 4.568E-13 4.919E-12 1.387E-10 1.915E-09 6.920E-09 6.593533 7.789E-10 1.613E-13 1.902E-12 6.130E-11 9.442E-10 3.584E-09 7.458715 4.005E-10 5.629E-14 7.309E-13 2.703E-11 4.623E-10 1.836E-09 8.437425 2.031 E-10 1.945E-14 2.798E-13 1.187E-11 2.240E-10 9.269E-10 9.544557 1.012E-10 6.676E-15 1.069E-13 5.179E-12 1.070E-10 4.591 E-10 10.796952 4.931E-11 2.281 E-15 4.077E-14 2.239E-12 5.015E-11 2.224E-10 12.213694 2.341 E-11 7.764E-16 1.548E-14 9.548E-13 2.299E-11 1.050E-10 13.816336 1.080E-11 2.632E-16 5.843E-15 4.002E-13 1.027E-11 4.811E-11 15.629272 4.823E-12 8.881 E-17 2.183E-15 1.641 E-13 4.461 E-12 2.137E-11 17.680094 2.082E-12 2.975E-17 8.042E-16 6.567E-14 1.876E-12 9.172E-12 20.000000 8.661 E-13 9.865E-18 2.911 E-16 2.556E-14 7.626E-13 3.797E-12 92 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.7-4: The 5% Damped SA at 5 Hz Control Point Hazard Curves for the CGS Site PSA Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile [g] AFE AFE AFE AFE AFE AFE 0.000100 9.491 E-02 6.188E-02 7.104E-02 8.741 E-02 1.128E-01 1.527E-01 0.000113 9.491 E-02 6.188E-02 7.104E-02 8.741 E-02 1.128E-01 1.527E-01 0.000128 9.490E-02 6.188E-02 7.104E-02 8.740E-02 1.128E-01 1.527E-01 0.000145 9.489E-02 6.187E-02 7.103E-02 8.740E-02 1.128E-01 1.527E-01 0.000164 9.488E-02 6.186E-02 7.102E-02 8.739E-02 1.128E-01 1.526E-01 0.000185 9.484E-02 6.185E-02 7.100E-02 8.736E-02 1.127E-01 1.525E-01 0.000210 9.477E-02 6.182E-02 7.097E-02 8.732E-02 1.126E-01 1.524E-01 0.000237 9.465E-02 6.177E-02 7.092E-02 8.725E-02 1.125E-01 1.520E-01 0.000268 9.449E-02 6.170E-02 7.083E-02 8.715E-02 1.123E-01 1.516E-01 0.000303 9.424E-02 6.159E-02 7.071 E-02 8.700E-02 1.120E-01 1.510E-01 0.000343 9.394E-02 6.146E-02 7.056E-02 8.681 E-02 1.117E-01 1.502E-01 0.000388 9.357E-02 6.130E-02 7.038E-02 8.659E-02 1.112E-01 1.492E-01 0.000439 9.317E-02 6.112E-02 7.017E-02 8.634E-02 1.107E-01 1.481 E-01 0.000497 9.272E-02 6.092E-02 6.995E-02 8.606E-02 1.102E-01 1.470E-01 0.000562 9.225E-02 6.072E-02 6.971 E-02 8.577E-02 1.096E-01 1.457E-01 0.000636 9.177E-02 6.050E-02 6.947E-02 8.548E-02 1.091 E-01 1.444E-01 0.000719 9.128E-02 6.029E-02 6.922E-02 8.517E-02 1.085E-01 1.432E-01 0.000813 9.078E-02 6.007E-02 6.897E-02 8.485E-02 1.079E-01 1.419E-01 0.000920 9.026E-02 5.983E-02 6.869E-02 8.451 E-02 1.073E-01 1.405E-01 0.001041 8.968E-02 5.956E-02 6.839E-02 8.414E-02 1.066E-01 1.391 E-01 0.001177 8.904E-02 5.925E-02 6.803E-02 8.370E-02 1.059E-01 1.375E-01 0.001332 8.828E-02 5.887E-02 6.759E-02 8.316E-02 1.051 E-01 1.358E-01 0.001507 8.737E-02 5.839E-02 6.705E-02 8.250E-02 1.042E-01 1.337E-01 0.001704 8.629E-02 5.778E-02 6.636E-02 8.166E-02 1.030E-01 1.313E-01 0.001928 8.498E-02 5.704E-02 6.551 E-02 8.063E-02 1.017E-01 1.285E-01 0.002181 8.343E-02 5.61 OE-02 6.447E-02 7.938E-02 1.001 E-01 1.254E-01 0.002467 8.163E-02 5.495E-02 6.319E-02 7.787E-02 9.816E-02 1.220E-01 0.002791 7.956E-02 5.355E-02 6.166E-02 7.606E-02 9.595E-02 1.183E-01 0.003157 7.721 E-02 5.189E-02 5.985E-02 7.397E-02 9.341 E-02 1.143E-01 0.003571 7.459E-02 4.997E-02 5.777E-02 7.158E-02 9.054E-02 1.101 E-01 0.004040 7.175E-02 4.784E-02 5.547E-02 6.894E-02 8.738E-02 1.058E-01 0.004570 6.875E-02 4.553E-02 5.300E-02 6.612E-02 8.402E-02 1.014E-01 0.005170 6.568E-02 4.315E-02 5.044E-02 6.320E-02 8.054E-02 9.704E-02 0.005848 6.260E-02 4.076E-02 4.787E-02 6.025E-02 7.703E-02 9.270E-02 0.006615 5.957E-02 3.842E-02 4.534E-02 5.735E-02 7.356E-02 8.847E-02 0.007483 5.664E-02 3.615E-02 4.288E-02 5.452E-02 7.018E-02 8.438E-02 0.008465 5.380E-02 3.398E-02 4.052E-02 5.179E-02 6.690E-02 8.043E-02 0.009576 5.105E-02 3.191 E-02 3.825E-02 4.915E-02 6.372E-02 7.661 E-02 0.010833 4.838E-02 2.992E-02 3.604E-02 4.658E-02 6.062E-02 7.287E-02 0.012254 4.575E-02 2.798E-02 3.388E-02 4.405E-02 5.755E-02 6.919E-02 93 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure PSA Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile [g] AFE AFE AFE AFE AFE AFE 0.013862 4.312E-02 2.608E-02 3.173E-02 4.152E-02 5.448E-02 6.550E-02 0.015681 4.046E-02 2.41 SE-02 2.957E-02 3.897E-02 5.138E-02 6.177E-02 0.017739 3.778E-02 2.231 E-02 2.740E-02 3.639E-02 4.823E-02 5.799E-02 0.020066 3.508E-02 2.044E-02 2.522E-02 3.379E-02 4.504E-02 5.418E-02 0.022699 3.238E-02 1.861 E-02 2.307E-02 3.119E-02 4.185E-02 5.036E-02 0.025678 2.973E-02 1.684E-02 2.096E-02 2.865E-02 3.867E-02 4.659E-02 0.029047 2.716E-02 1.514E-02 1.894E-02 2.617E-02 3.555E-02 4.291 E-02 0.032859 2.469E-02 1.353E-02 1.702E-02 2.378E-02 3.252E-02 3.934E-02 0.037170 2.235E-02 1.203E-02 1.522E-02 2.151 E-02 2.959E-02 3.593E-02 0.042048 2.015E-02 1.064E-02 1.355E-02 1.937E-02 2.679E-02 3.269E-02 0.047565 1.808E-02 9.366E-03 1.200E-02 1.736E-02 2.415E-02 2.962E-02 0.053806 1.616E-02 8.202E-03 1.058E-02 1.548E-02 2.166E-02 2.674E-02 0.060867 1.437E-02 7.145E-03 9.280E-03 1.373E-02 1.934E-02 2.404E-02 0.068853 1.271 E-02 6.192E-03 8.098E-03 1.211 E-02 1.719E-02 2.150E-02 0.077888 1.119E-02 5.336E-03 7.027E-03 1.062E-02 1.520E-02 1.915E-02 0.088108 9.792E-03 4.571 E-03 6.062E-03 9.262E-03 1.337E-02 1.696E-02 0.099670 8.522E-03 3.894E-03 5.201 E-03 8.025E-03 1.171 E-02 1.494E-02 0.112748 7.377E-03 3.298E-03 4.437E-03 6.916E-03 1.020E-02 1.311 E-02 0.127542 6.354E-03 2.779E-03 3.766E-03 5.928E-03 8.851 E-03 1.145E-02 0.144278 5.446E-03 2.329E-03 3.181 E-03 5.055E-03 7.643E-03 9.944E-03 0.163210 4.644E-03 1.941 E-03 2.672E-03 4.289E-03 6.567E-03 8.597E-03 0.184625 3.939E-03 1.607E-03 2.233E-03 3.618E-03 5.613E-03 7.390E-03 0.208851 3.321 E-03 1.322E-03 1.853E-03 3.034E-03 4.770E-03 6.316E-03 0.236256 2.782E-03 1.078E-03 1.527E-03 2.528E-03 4.027E-03 5.364E-03 0.267257 2.314E-03 8.719E-04 1.249E-03 2.090E-03 3.376E-03 4.524E-03 0.302325 1.910E-03 6.984E-04 1.011 E-03 1.714E-03 2.809E-03 3.789E-03 0.341995 1.564E-03 5.537E-04 8.107E-04 1.394E-03 2.318E-03 3.149E-03 0.386871 1.269E-03 4.338E-04 6.426E-04 1.123E-03 1.896E-03 2.597E-03 0.437634 1.020E-03 3.356E-04 5.033E-04 8.953E-04 1.536E-03 2.123E-03 0.495059 8.115E-04 2.560E-04 3.890E-04 7.058E-04 1.231 E-03 1.719E-03 0.560020 6.381 E-04 1.923E-04 2.964E-04 5.497E-04 9.753E-04 1.377E-03 0.633503 4.954E-04 1.422E-04 2.224E-04 4.224E-04 7.630E-04 1.091 E-03 0.716629 3.794E-04 1.032E-04 1.642E-04 3.199E-04 5.888E-04 8.538E-04 0.810663 2.861 E-04 7.344E-05 1.191 E-04 2.384E-04 4.476E-04 6.584E-04 0.917036 2.123E-04 5.123E-05 8.471 E-05 1.747E-04 3.348E-04 5.000E-04 1.037366 1.548E-04 3.497E-05 5.91 OE-05 1.256E-04 2.462E-04 3.734E-04 1.173485 1.108E-04 2.334E-05 4.036E-05 8.850E-05 1.776E-04 2.738E-04 1.327466 7.773E-05 1.522E-05 2.696E-05 6.110E-05 1.257E-04 1.969E-04 1.501652 5.346E-05 9.692E-06 1.760E-05 4.126E-05 8.719E-05 1.389E-04 1.698694 3.599E-05 6.025E-06 1.122E-05 2.724E-05 5.920E-05 9.582E-05 1.921589 2.371 E-05 3.654E-06 6.985E-06 1.757E-05 3.932E-05 6.470E-05 2.173734 1.528E-05 2.162E-06 4.243E-06 1.107E-05 2.554E-05 4.272E-05 94 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure PSA Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile [g] AFE AFE AFE AFE AFE AFE 2.458964 9.625E-06 1.247E-06 2.515E-06 6.808E-06 1.621 E-05 2.757E-05 2.781622 5.928E-06 7.020E-07 1.454E-06 4.087E-06 1.005E-05 1.739E-05 3.146617 3.568E-06 3.850E-07 8.195E-07 2.394E-06 6.083E-06 1.072E-05 3.559503 2.100E-06 2.059E-07 4.504E-07 1.369E-06 3.597E-06 6.451 E-06 4.026569 1.208E-06 1.073E-07 2.414E-07 7.631 E-07 2.077E-06 3.798E-06 4.554923 6.795E-07 5.454E-08 1.262E-07 4.152E-07 1.171E-06 2.185E-06 5.152606 3.741 E-07 2.701 E-08 6.429E-08 2.205E-07 6.457E-07 1.231 E-06 5.828714 2.018E-07 1.304E-08 3.196E-08 1.144E-07 3.480E-07 6.786E-07 6.593533 1.067E-07 6.137E-09 1.550E-08 5.793E-08 1.836E-07 3.672E-07 7.458715 5.549E-08 2.816E-09 7.331 E-09 2.867E-08 9.496E-08 1.952E-07 8.437425 2.840E-08 1.260E-09 3.387E-09 1.389E-08 4.824E-08 1.023E-07 9.544557 1.435E-08 5.498E-10 1.528E-09 6.592E-09 2.412E-08 5.289E-08 10.796952 7.188E-09 2.343E-10 6.741E-10 3.072E-09 1.190E-08 2.711 E-08 12.213694 3.578E-09 9.749E-11 2.912E-10 1.408E-09 5.813E-09 1.381 E-08 13.816336 1.777E-09 3.967E-11 1.233E-10 6.365E-10 2.818E-09 7.007E-09 15.629272 8.825E-10 1.580E-11 5.133E-11 2.847E-10 1.361 E-09 3.551 E-09 17.680094 4.394E-10 6.178E-12 2.105E-11 1.264E-10 6.562E-10 1.799E-09 20.000000 2.193E-10 2.373E-12 8.521 E-12 5.581 E-11 3.162E-10 9.113E-10 95 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.7-5: The 5% Damped SA at 2.5 Hz Control Point Hazard Curves for the CGS Site PSA Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile [g] AFE AFE AFE AFE AFE AFE 0.000100 9.485E-02 6.185E-02 7.100E-02 8.736E-02 1.125E-01 1.561 E-01 0.000113 9.480E-02 6.182E-02 7.097E-02 8.732E-02 1.125E-01 1.559E-01 0.000128 9.471 E-02 6.176E-02 7.091 E-02 8.724E-02 1.124E-01 1.555E-01 0.000145 9.457E-02 6.168E-02 7.082E-02 8.714E-02 1.123E-01 1.551 E-01 0.000164 9.438E-02 6.158E-02 7.070E-02 8.698E-02 1.121E-01 1.544E-01 0.000185 9.414E-02 6.144E-02 7.054E-02 8.679E-02 1.118E-01 1.535E-01 0.000210 9.385E-02 6.128E-02 7.035E-02 8.656E-02 1.115E-01 1.526E-01 0.000237 9.352E-02 6.11 OE-02 7.014E-02 8.631 E-02 1.112E-01 1.514E-01 0.000268 9.318E-02 6.090E-02 6.992E-02 8.603E-02 1.108E-01 1.502E-01 0.000303 9.282E-02 6.070E-02 6.968E-02 8.574E-02 1.105E-01 1.489E-01 0.000343 9.244E-02 6.048E-02 6.944E-02 8.544E-02 1.101 E-01 1.477E-01 0.000388 9.206E-02 6.027E-02 6.920E-02 8.513E-02 1.097E-01 1.464E-01 0.000439 9.166E-02 6.004E-02 6.894E-02 8.482E-02 1.093E-01 1.450E-01 0.000497 9.123E-02 5.980E-02 6.866E-02 8.448E-02 1.089E-01 1.436E-01 0.000562 9.076E-02 5.953E-02 6.836E-02 8.410E-02 1.083E-01 1.421 E-01 0.000636 9.019E-02 5.921 E-02 6.799E-02 8.365E-02 1.077E-01 1.405E-01 0.000719 8.949E-02 5.883E-02 6.755E-02 8.310E-02 1.069E-01 1.387E-01 0.000813 8.862E-02 5.833E-02 6.698E-02 8.242E-02 1.059E-01 1.365E-01 0.000920 8.752E-02 5.771 E-02 6.628E-02 8.156E-02 1.046E-01 1.340E-01 0.001041 8.618E-02 5.693E-02 6.540E-02 8.049E-02 1.030E-01 1.311 E-01 0.001177 8.456E-02 5.595E-02 6.429E-02 7.917E-02 1.011 E-01 1.278E-01 0.001332 8.262E-02 5.473E-02 6.294E-02 7.757E-02 9.880E-02 1.241 E-01 0.001507 8.035E-02 5.324E-02 6.131 E-02 7.565E-02 9.618E-02 1.200E-01 0.001704 7.774E-02 5.146E-02 5.936E-02 7.338E-02 9.320E-02 1.156E-01 0.001928 7.480E-02 4.940E-02 5.712E-02 7.079E-02 8.988E-02 1.109E-01 0.002181 7.160E-02 4.71 OE-02 5.463E-02 6.792E-02 8.630E-02 1.059E-01 0.002467 6.822E-02 4.464E-02 5.197E-02 6.485E-02 8.254E-02 1.008E-01 0.002791 6.475E-02 4.21 OE-02 4.922E-02 6.170E-02 7.869E-02 9.576E-02 0.003157 6.130E-02 3.956E-02 4.647E-02 5.852E-02 7.486E-02 9.074E-02 0.003571 5.793E-02 3.709E-02 4.379E-02 5.541 E-02 7.11 OE-02 8.587E-02 0.004040 5.468E-02 3.472E-02 4.120E-02 5.241 E-02 6.747E-02 8.119E-02 0.004570 5.156E-02 3.247E-02 3.872E-02 4.951 E-02 6.395E-02 7.671 E-02 0.005170 4.857E-02 3.032E-02 3.634E-02 4.672E-02 6.057E-02 7.241 E-02 0.005848 4.568E-02 2.827E-02 3.405E-02 4.401 E-02 5.725E-02 6.826E-02 0.006615 4.284E-02 2.629E-02 3.181 E-02 4.134E-02 5.396E-02 6.421 E-02 0.007483 4.002E-02 2.435E-02 2.959E-02 3.867E-02 5.065E-02 6.020E-02 0.008465 3.720E-02 2.244E-02 2.736E-02 3.597E-02 4.728E-02 5.621 E-02 0.009576 3.437E-02 2.055E-02 2.513E-02 3.324E-02 4.386E-02 5.221 E-02 0.010833 3.155E-02 1.869E-02 2.291 E-02 3.0SOE-02 4.040E-02 4.824E-02 0.012254 2.877E-02 1.688E-02 2.073E-02 2.780E-02 3.696E-02 4.432E-02 96 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure PSA Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile [g] AFE AFE AFE AFE AFE AFE 0.013862 2.608E-02 1.514E-02 1.863E-02 2.516E-02 3.360E-02 4.049E-02 0.015681 2.350E-02 1.349E-02 1.664E-02 2.264E-02 3.038E-02 3.681 E-02 0.017739 2.107E-02 1.195E-02 1.478E-02 2.026E-02 2.732E-02 3.330E-02 0.020066 1.881 E-02 1.052E-02 1.305E-02 1.803E-02 2.447E-02 2.999E-02 0.022699 1.672E-02 9.200E-03 1.147E-02 1.598E-02 2.182E-02 2.690E-02 0.025678 1.479E-02 8.006E-03 1.004E-02 1.410E-02 1.939E-02 2.403E-02 0.029047 1.304E-02 6.930E-03 8.746E-03 1.240E-02 1.717E-02 2.139E-02 0.032859 1.146E-02 5.968E-03 7.587E-03 1.085E-02 1.516E-02 1.898E-02 0.037170 1.003E-02 5.116E-03 6.554E-03 9.470E-03 1.335E-02 1.680E-02 0.042048 8.750E-03 4.366E-03 5.638E-03 8.238E-03 1.173E-02 1.483E-02 0.047565 7.612E-03 3.711 E-03 4.832E-03 7.144E-03 1.028E-02 1.306E-02 0.053806 6.604E-03 3.143E-03 4.127E-03 6.180E-03 8.987E-03 1.148E-02 0.060867 5.715E-03 2.655E-03 3.51 SE-03 5.332E-03 7.840E-03 1.007E-02 0.068853 4.935E-03 2.237E-03 2.986E-03 4.590E-03 6.826E-03 8.824E-03 0.077888 4.251 E-03 1.880E-03 2.530E-03 3.940E-03 5.927E-03 7.709E-03 0.088108 3.653E-03 1.577E-03 2.139E-03 3.373E-03 5.132E-03 6.717E-03 0.099670 3.130E-03 1.320E-03 1.803E-03 2.878E-03 4.428E-03 5.833E-03 0.112748 2.674E-03 1.103E-03 1.516E-03 2.446E-03 3.807E-03 5.046E-03 0.127542 2.276E-03 9.180E-04 1.270E-03 2.070E-03 3.259E-03 4.348E-03 0.144278 1.930E-03 7.615E-04 1.060E-03 1.744E-03 2.778E-03 3.730E-03 0.163210 1.629E-03 6.291 E-04 8.809E-04 1.463E-03 2.358E-03 3.187E-03 0.184625 1.370E-03 5.171 E-04 7.289E-04 1.222E-03 1.992E-03 2.709E-03 0.208851 1.146E-03 4.226E-04 6.002E-04 1.01 SE-03 1.676E-03 2.293E-03 0.236256 9.536E-04 3.431 E-04 4.914E-04 8.390E-04 1.403E-03 1.931 E-03 0.267257 7.893E-04 2.765E-04 3.998E-04 6.895E-04 1.168E-03 1.617E-03 0.302325 6.491 E-04 2.209E-04 3.229E-04 5.630E-04 9.670E-04 1.347E-03 0.341995 5.300E-04 1.749E-04 2.586E-04 4.564E-04 7.955E-04 1.114E-03 0.386871 4.293E-04 1.370E-04 2.052E-04 3.669E-04 6.492E-04 9.156E-04 0.437634 3.447E-04 1.060E-04 1.61 OE-04 2.922E-04 5.252E-04 7.463E-04 0.495059 2.739E-04 8.097E-05 1.247E-04 2.302E-04 4.207E-04 6.030E-04 0.560020 2.151 E-04 6.091 E-05 9.528E-05 1.790E-04 3.331 E-04 4.821 E-04 0.633503 1.668E-04 4.505E-05 7.161 E-05 1.373E-04 2.603E-04 3.810E-04 0.716629 1.274E-04 3.271 E-05 5.287E-05 1.036E-04 2.005E-04 2.971 E-04 0.810663 9.582E-05 2.327E-05 3.828E-05 7.689E-05 1.519E-04 2.283E-04 0.917036 7.080E-05 1.620E-05 2.714E-05 5.598E-05 1.131E-04 1.726E-04 1.037366 5.135E-05 1.102E-05 1.883E-05 3.995E-05 8.269E-05 1.283E-04 1.173485 3.653E-05 7.321 E-06 1.277E-05 2.791 E-05 5.927E-05 9.356E-05 1.327466 2.547E-05 4.744E-06 8.455E-06 1.909E-05 4.163E-05 6.694E-05 1.501652 1.741 E-05 2.998E-06 5.468E-06 1.277E-05 2.864E-05 4.697E-05 1.698694 1.166E-05 1.847E-06 3.453E-06 8.350E-06 1.931 E-05 3.232E-05 1.921589 7.655E-06 1.109E-06 2.130E-06 5.344E-06 1.275E-05 2.180E-05 2.173734 4.932E-06 6.506E-07 1.284E-06 3.349E-06 8.258E-06 1.444E-05 97 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure PSA Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile [g] AFE AFE AFE AFE AFE AFE 2.458964 3.121 E-06 3.725E-07 7.568E-07 2.056E-06 5.249E-06 9.386E-06 2.781622 1.942E-06 2.086E-07 4.367E-07 1.239E-06 3.277E-06 6.002E-06 3.146617 1.190E-06 1.143E-07 2.471 E-07 7.328E-07 2.013E-06 3.777E-06 3.559503 7.190E-07 6.147E-08 1.373E-07 4.264E-07 1.217E-06 2.342E-06 4.026569 4.290E-07 3.245E-08 7.496E-08 2.443E-07 7.264E-07 1.434E-06 4.554923 2.531 E-07 1.684E-08 4.029E-08 1.379E-07 4.279E-07 8.671 E-07 5.152606 1.479E-07 8.61 OE-09 2.134E-08 7.689E-08 2.492E-07 5.188E-07 5.828714 8.566E-08 4.338E-09 1.115E-08 4.236E-08 1.437E-07 3.075E-07 6.593533 4.925E-08 2.157E-09 5.759E-09 2.307E-08 8.203E-08 1.807E-07 7.458715 2.814E-08 1.059E-09 2.939E-09 1.244E-08 4.646E-08 1.054E-07 8.437425 1.598E-08 5.138E-10 1.484E-09 6.639E-09 2.611 E-08 6.105E-08 9.544557 9.033E-09 2.464E-10 7.408E-10 3.510E-09 1.456E-08 3.515E-08 10.796952 5.082E-09 1.168E-10 3.660E-10 1.839E-09 8.068E-09 2.012E-08 12.213694 2.846E-09 5.469E-11 1.789E-10 9.545E-10 4.439E-09 1.145E-08 13.816336 1.587E-09 2.530E-11 8.643E-11 4.911 E-10 2.426E-09 6.477E-09 15.629272 8.816E-10 1.155E-11 4.128E-11 2.505E-10 1.318E-09 3.643E-09 17.680094 4.873E-10 5.206E-12 1.949E-11 1.266E-10 7.109E-10 2.036E-09 20.000000 2.678E-10 2.314E-12 9.102E-12 6.349E-11 3.807E-10 1.130E-09 98 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.7-6: The 5% Damped SA at 1 Hz Control Point Hazard Curves for the CGS Site PSA Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile [g] AFE AFE AFE AFE AFE AFE 0.000010 9.458E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.000011 9.458E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.000013 9.458E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.000015 9.458E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.000017 9.458E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.000020 9.458E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.000023 9.457E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.000027 9.457E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.000031 9.456E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.000035 9.455E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.000040 9.454E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.000046 9.453E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.000053 9.452E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.000061 9.451 E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.000071 9.450E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.000081 9.449E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.000093 9.448E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.000107 9.446E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.000123 9.442E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.548E-01 0.000142 9.433E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.544E-01 0.000163 9.420E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.538E-01 0.000187 9.404E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.531 E-01 0.000215 9.382E-02 6.161 E-02 7.074E-02 8.704E-02 1.122E-01 1.523E-01 0.000248 9.335E-02 6.139E-02 7.048E-02 8.676E-02 1.118E-01 1.510E-01 0.000285 9.239E-02 6.081 E-02 6.981 E-02 8.603E-02 1.108E-01 1.487E-01 0.000327 9.098E-02 5.989E-02 6.876E-02 8.487E-02 1.093E-01 1.457E-01 0.000376 8.940E-02 5.885E-02 6.757E-02 8.356E-02 1.076E-01 1.423E-01 0.000433 8.781 E-02 5.781 E-02 6.636E-02 8.224E-02 1.059E-01 1.389E-01 0.000498 8.624E-02 5.678E-02 6.51 SE-02 8.093E-02 1.043E-01 1.356E-01 0.000572 8.471 E-02 5.576E-02 6.402E-02 7.965E-02 1.026E-01 1.324E-01 0.000658 8.320E-02 5.477E-02 6.288E-02 7.839E-02 1.01 OE-01 1.292E-01 0.000756 8.172E-02 5.380E-02 6.176E-02 7.715E-02 9.939E-02 1.262E-01 0.000870 8.027E-02 5.284E-02 6.066E-02 7.592E-02 9.781 E-02 1.232E-01 0.001000 7.882E-02 5.188E-02 5.956E-02 7.470E-02 9.624E-02 1.203E-01 0.001150 7.723E-02 5.081 E-02 5.836E-02 7.335E-02 9.450E-02 1.172E-01 0.001322 7.500E-02 4.926E-02 5.665E-02 7.139E-02 9.198E-02 1.133E-01 0.001520 7.177E-02 4.695E-02 5.417E-02 6.854E-02 8.830E-02 1.081 E-01 0.001748 6.811 E-02 4.431 E-02 5.135E-02 6.525E-02 8.407E-02 1.025E-01 0.002009 6.449E-02 4.172E-02 4.857E-02 6.201 E-02 7.988E-02 9.692E-02 0.002310 6.093E-02 3.91 BE-02 4.583E-02 5.878E-02 7.574E-02 9.149E-02 99 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure PSA Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile [g] AFE AFE AFE AFE AFE AFE 0.002656 5.706E-02 3.645E-02 4.281 E-02 5.518E-02 7.116E-02 8.570E-02 0.003054 5.266E-02 3.338E-02 3.933E-02 5.097E-02 6.588E-02 7.923E-02 0.003511 4.819E-02 3.028E-02 3.579E-02 4.665E-02 6.046E-02 7.269E-02 0.004037 4.402E-02 2.742E-02 3.251 E-02 4.262E-02 5.539E-02 6.660E-02 0.004642 4.020E-02 2.483E-02 2.952E-02 3.892E-02 5.074E-02 6.100E-02 0.005337 3.671 E-02 2.248E-02 2.680E-02 3.555E-02 4.648E-02 5.587E-02 0.006136 3.351 E-02 2.034E-02 2.433E-02 3.245E-02 4.255E-02 5.116E-02 0.007055 3.052E-02 1.836E-02 2.203E-02 2.955E-02 3.887E-02 4.676E-02 0.008111 2.755E-02 1.644E-02 1.981 E-02 2.666E-02 3.521 E-02 4.245E-02 0.009326 2.457E-02 1.453E-02 1.760E-02 2.373E-02 3.151E-02 3.817E-02 0.010723 2.173E-02 1.274E-02 1.552E-02 2.095E-02 2.799E-02 3.409E-02 0.012328 1.914E-02 1.111 E-02 1.361 E-02 1.841 E-02 2.474E-02 3.032E-02 0.014175 1.672E-02 9.574E-03 1.180E-02 1.606E-02 2.170E-02 2.674E-02 0.016298 1.451 E-02 8.159E-03 1.01 OE-02 1.391 E-02 1.888E-02 2.338E-02 0.018738 1.253E-02 6.911 E-03 8.598E-03 1.199E-02 1.636E-02 2.036E-02 0.021544 1.080E-02 5.838E-03 7.298E-03 1.033E-02 1.416E-02 1.771 E-02 0.024771 9.281 E-03 4.895E-03 6.158E-03 8.850E-03 1.223E-02 1.536E-02 0.028480 7.908E-03 4.043E-03 5.132E-03 7.512E-03 1.053E-02 1.328E-02 0.032745 6.686E-03 3.287E-03 4.222E-03 6.315E-03 9.026E-03 1.144E-02 0.037649 5.630E-03 2.650E-03 3.452E-03 5.284E-03 7.728E-03 9.842E-03 0.043288 4.732E-03 2.131 E-03 2.815E-03 4.410E-03 6.606E-03 8.461 E-03 0.049770 3.963E-03 1.706E-03 2.283E-03 3.662E-03 5.625E-03 7.267E-03 0.057224 3.294E-03 1.355E-03 1.832E-03 3.009E-03 4.754E-03 6.234E-03 0.065793 2.715E-03 1.065E-03 1.454E-03 2.445E-03 3.982E-03 5.329E-03 0.075646 2.219E-03 8.330E-04 1.146E-03 1.966E-03 3.301 E-03 4.510E-03 0.086975 1.794E-03 6.481 E-04 8.981 E-04 1.563E-03 2.699E-03 3.754E-03 0.100000 1.438E-03 5.023E-04 7.009E-04 1.231 E-03 2.184E-03 3.080E-03 0.114976 1.144E-03 3.871 E-04 5.444E-04 9.629E-04 1.750E-03 2.500E-03 0.132194 8.982E-04 2.944E-04 4.185E-04 7.458E-04 1.380E-03 1.995E-03 0.151991 6.933E-04 2.199E-04 3.175E-04 5.707E-04 1.067E-03 1.559E-03 0.174753 5.293E-04 1.623E-04 2.387E-04 4.331 E-04 8.147E-04 1.202E-03 0.200923 4.016E-04 1.189E-04 1.782E-04 3.268E-04 6.182E-04 9.205E-04 0.231013 3.019E-04 8.603E-05 1.315E-04 2.444E-04 4.654E-04 6.996E-04 0.265609 2.236E-04 6.084E-05 9.494E-05 1.800E-04 3.462E-04 5.252E-04 0.305386 1.633E-04 4.200E-05 6.706E-05 1.305E-04 2.547E-04 3.899E-04 0.351119 1.185E-04 2.864E-05 4.686E-05 9.415E-05 1.867E-04 2.884E-04 0.403702 8.606E-05 1.950E-05 3.268E-05 6.782E-05 1.370E-04 2.134E-04 0.464159 6.239E-05 1.325E-05 2.274E-05 4.870E-05 1.003E-04 1.577E-04 0.533670 4.490E-05 8.926E-06 1.567E-05 3.462E-05 7.286E-05 1.157E-04 0.613591 3.181E-05 5.896E-06 1.060E-05 2.415E-05 5.207E-05 8.363E-05 0.705481 2.202E-05 3.785E-06 6.973E-06 1.640E-05 3.635E-05 5.915E-05 0.811131 1.483E-05 2.345E-06 4.435E-06 1.079E-05 2.467E-05 4.078E-05 1 oo of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure PSA Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile [g] AFE AFE AFE AFE AFE AFE 0.932604 9.702E-06 1.398E-06 2.720E-06 6.873E-06 1.624E-05 2.735E-05 1.072268 6.171E-06 8.023E-07 1.611 E-06 4.241 E-06 1.040E-05 1.788E-05 1.232847 3.831 E-06 4.452E-07 9.253E-07 2.547E-06 6.486E-06 1.142E-05 1.417475 2.328E-06 2.404E-07 5.183E-07 1.494E-06 3.956E-06 7.143E-06 1.629751 1.386E-06 1.271 E-07 2.843E-07 8.582E-07 2.361 E-06 4.370E-06 1.873819 8.065E-07 6.589E-08 1.526E-07 4.814E-07 1.374E-06 2.607E-06 2.154435 4.562E-07 3.338E-08 7.980E-08 2.624E-07 7.766E-07 1.510E-06 2.477078 2.500E-07 1.641 E-08 4.040E-08 1.383E-07 4.244E-07 8.466E-07 2.848037 1.324E-07 7.773E-09 1.967E-08 7.003E-08 2.237E-07 4.588E-07 3.274549 6.794E-08 3.525E-09 9.169E-09 3.407E-08 1.138E-07 2.410E-07 3.764938 3.393E-08 1.526E-09 4.088E-09 1.594E-08 5.619E-08 1.234E-07 4.328762 1.662E-08 6.309E-10 1.746E-09 7.207E-09 2.708E-08 6.213E-08 4.977026 8.067E-09 2.498E-10 7.182E-10 3.172E-09 1.286E-08 3.100E-08 5.722369 3.914E-09 9.512E-11 2.861E-10 1.370E-09 6.068E-09 1.545E-08 6.579331 1.912E-09 3.507E-11 1.113E-10 5.863E-10 2.866E-09 7.734E-09 7.564636 9.431 E-10 1.260E-11 4.256E-11 2.502E-10 1.360E-09 3.893E-09 8.697490 4.693E-10 4.441E-12 1.613E-11 1.071E-10 6.492E-10 1.969E-09 10.000005 2.350E-10 1.543E-12 6.090E-12 4.606E-11 3.112E-10 9.969E-10 101 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.7-7: The 5% Damped SA at 0.5 Hz Control Point Hazard Curves for the CGS Site PSA Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile [g] AFE AFE AFE AFE AFE AFE 0.000010 9.476E-02 6.178E-02 7.093E-02 8.727E-02 1.124E-01 1.555E-01 0.000011 9.476E-02 6.178E-02 7.093E-02 8.727E-02 1.124E-01 1.555E-01 0.000013 9.476E-02 6.178E-02 7.093E-02 8.727E-02 1.124E-01 1.555E-01 0.000015 9.476E-02 6.178E-02 7.093E-02 8.727E-02 1.124E-01 1.555E-01 0.000017 9.472E-02 6.176E-02 7.090E-02 8.724E-02 1.124E-01 1.554E-01 0.000020 9.460E-02 6.169E-02 7.082E-02 8.714E-02 1.122E-01 1.550E-01 0.000023 9.443E-02 6.158E-02 7.069E-02 8.698E-02 1.120E-01 1.545E-01 0.000027 9.423E-02 6.146E-02 7.056E-02 8.681 E-02 1.118E-01 1.539E-01 0.000031 9.403E-02 6.133E-02 7.042E-02 8.664E-02 1.116E-01 1.533E-01 0.000035 9.383E-02 6.121 E-02 7.028E-02 8.646E-02 1.114E-01 1.526E-01 0.000040 9.363E-02 6.109E-02 7.014E-02 8.629E-02 1.111E-01 1.520E-01 0.000046 9.344E-02 6.097E-02 7.000E-02 8.612E-02 1.109E-01 1.514E-01 0.000053 9.324E-02 6.085E-02 6.986E-02 8.595E-02 1.107E-01 1.508E-01 0.000061 9.304E-02 6.073E-02 6.972E-02 8.577E-02 1.105E-01 1.502E-01 0.000071 9.284E-02 6.061 E-02 6.958E-02 8.560E-02 1.102E-01 1.496E-01 0.000081 9.263E-02 6.047E-02 6.943E-02 8.542E-02 1.100E-01 1.490E-01 0.000093 9.231 E-02 6.028E-02 6.920E-02 8.518E-02 1.096E-01 1.481 E-01 0.000107 9.169E-02 5.989E-02 6.876E-02 8.479E-02 1.089E-01 1.465E-01 0.000123 9.067E-02 5.926E-02 6.804E-02 8.418E-02 1.078E-01 1.439E-01 0.000142 8.942E-02 5.849E-02 6.71 SE-02 8.343E-02 1.064E-01 1.408E-01 0.000163 8.807E-02 5.765E-02 6.620E-02 8.262E-02 1.049E-01 1.375E-01 0.000187 8.646E-02 5.660E-02 6.502E-02 8.150E-02 1.031 E-01 1.339E-01 0.000215 8.408E-02 5.495E-02 6.322E-02 7.953E-02 1.00SE-01 1.296E-01 0.000248 8.077E-02 5.259E-02 6.067E-02 7.653E-02 9.682E-02 1.242E-01 0.000285 7.701 E-02 4.986E-02 5.775E-02 7.300E-02 9.268E-02 1.184E-01 0.000327 7.326E-02 4.717E-02 5.484E-02 6.947E-02 8.854E-02 1.127E-01 0.000376 6.969E-02 4.461 E-02 5.207E-02 6.609E-02 8.457E-02 1.072E-01 0.000433 6.628E-02 4.21 SE-02 4.943E-02 6.287E-02 8.078E-02 1.020E-01 0.000498 6.304E-02 3.989E-02 4.693E-02 5.981 E-02 7.715E-02 9.699E-02 0.000572 5.996E-02 3.772E-02 4.456E-02 5.690E-02 7.369E-02 9.227E-02 0.000658 5.703E-02 3.567E-02 4.231 E-02 5.413E-02 7.039E-02 8.778E-02 0.000756 5.424E-02 3.373E-02 4.016E-02 5.149E-02 6.723E-02 8.350E-02 0.000870 5.155E-02 3.187E-02 3.81 OE-02 4.895E-02 6.415E-02 7.937E-02 0.001000 4.875E-02 2.997E-02 3.595E-02 4.629E-02 6.088E-02 7.508E-02 0.001150 4.554E-02 2.786E-02 3.348E-02 4.326E-02 5.700E-02 7.017E-02 0.001322 4.207E-02 2.563E-02 3.081 E-02 3.998E-02 5.271 E-02 6.485E-02 0.001520 3.870E-02 2.348E-02 2.823E-02 3.681 E-02 4.852E-02 5.969E-02 0.001748 3.556E-02 2.149E-02 2.584E-02 3.384E-02 4.462E-02 5.489E-02 0.002009 3.257E-02 1.961 E-02 2.359E-02 3.102E-02 4.091 E-02 5.031 E-02 0.002310 2.960E-02 1.777E-02 2.137E-02 2.820E-02 3.726E-02 4.575E-02 102 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure PSA Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile [g] AFE AFE AFE AFE AFE AFE 0.002656 2.670E-02 1.599E-02 1.923E-02 2.546E-02 3.372E-02 4.129E-02 0.003054 2.402E-02 1.435E-02 1.726E-02 2.292E-02 3.045E-02 3.718E-02 0.003511 2.160E-02 1.288E-02 1.549E-02 2.063E-02 2.748E-02 3.346E-02 0.004037 1.943E-02 1.156E-02 1.390E-02 1.857E-02 2.481 E-02 3.012E-02 0.004642 1.747E-02 1.037E-02 1.247E-02 1.671 E-02 2.239E-02 2.711 E-02 0.005337 1.570E-02 9.294E-03 1.118E-02 1.502E-02 2.019E-02 2.438E-02 0.006136 1.404E-02 8.268E-03 9.971 E-03 1.345E-02 1.811 E-02 2.185E-02 0.007055 1.244E-02 7.244E-03 8.797E-03 1.192E-02 1.607E-02 1.944E-02 0.008111 1.092E-02 6.257E-03 7.683E-03 1.047E-02 1.413E-02 1.718E-02 0.009326 9.545E-03 5.358E-03 6.661 E-03 9.155E-03 1.238E-02 1.514E-02 0.010723 8.295E-03 4.528E-03 5.701 E-03 7.940E-03 1.083E-02 1.332E-02 0.012328 7.154E-03 3.755E-03 4.791 E-03 6.812E-03 9.471 E-03 1.171 E-02 0.014175 6.136E-03 3.073E-03 3.975E-03 5.800E-03 8.274E-03 1.028E-02 0.016298 5.255E-03 2.503E-03 3.284E-03 4.926E-03 7.226E-03 9.020E-03 0.018738 4.491 E-03 2.033E-03 2.704E-03 4.171 E-03 6.301 E-03 7.918E-03 0.021544 3.813E-03 1.636E-03 2.202E-03 3.495E-03 5.460E-03 6.947E-03 0.024771 3.205E-03 1.296E-03 1.763E-03 2.885E-03 4.689E-03 6.089E-03 0.028480 2.678E-03 1.01 SE-03 1.397E-03 2.358E-03 4.005E-03 5.335E-03 0.032745 2.233E-03 7.966E-04 1.104E-03 1.922E-03 3.415E-03 4.673E-03 0.037649 1.858E-03 6.229E-04 8.708E-04 1.562E-03 2.900E-03 4.078E-03 0.043288 1.534E-03 4.848E-04 6.835E-04 1.256E-03 2.432E-03 3.516E-03 0.049770 1.250E-03 3.741 E-04 5.31 SE-04 9.932E-04 2.001 E-03 2.977E-03 0.057224 1.006E-03 2.862E-04 4.102E-04 7.749E-04 1.618E-03 2.480E-03 0.065793 8.000E-04 2.166E-04 3.136E-04 5.991 E-04 1.289E-03 2.034E-03 0.075646 6.277E-04 1.617E-04 2.374E-04 4.597E-04 1.011 E-03 1.643E-03 0.086975 4.873E-04 1.195E-04 1.782E-04 3.507E-04 7.830E-04 1.309E-03 0.100000 3.753E-04 8.750E-05 1.329E-04 2.662E-04 6.014E-04 1.034E-03 0.114976 2.853E-04 6.312E-05 9.778E-05 1.999E-04 4.559E-04 8.010E-04 0.132194 2.128E-04 4.445E-05 7.050E-05 1.476E-04 3.389E-04 6.050E-04 0.151991 1.562E-04 3.068E-05 4.998E-05 1.075E-04 2.481 E-04 4.477E-04 0.174753 1.140E-04 2.098E-05 3.517E-05 7.786E-05 1.805E-04 3.286E-04 0.200923 8.287E-05 1.428E-05 2.464E-05 5.618E-05 1.31 OE-04 2.403E-04 0.231013 5.964E-05 9.580E-06 1.705E-05 4.007E-05 9.424E-05 1.742E-04 0.265609 4.205E-05 6.238E-06 1.147E-05 2.791 E-05 6.672E-05 1.241 E-04 0.305386 2.904E-05 3.924E-06 7.499E-06 1.897E-05 4.649E-05 8.695E-05 0.351119 1.991 E-05 2.426E-06 4.835E-06 1.276E-05 3.226E-05 6.060E-05 0.403702 1.373E-05 1.509E-06 3.135E-06 8.635E-06 2.252E-05 4.249E-05 0.464159 9.500E-06 9.477E-07 2.046E-06 5.864E-06 1.576E-05 2.988E-05 0.533670 6.508E-06 5.924E-07 1.325E-06 3.942E-06 1.090E-05 2.079E-05 0.613591 4.354E-06 3.616E-07 8.357E-07 2.583E-06 7.347E-06 1.414E-05 0.705481 2.818E-06 2.126E-07 5.078E-07 1.633E-06 4.785E-06 9.314E-06 0.811131 1.762E-06 1.197E-07 2.956E-07 9.927E-07 3.00SE-06 5.937E-06 103 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure PSA Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile [g] AFE AFE AFE AFE AFE AFE 0.932604 1.068E-06 6.462E-08 1.653E-07 5.821 E-07 1.827E-06 3.675E-06 1.072268 6.321 E-07 3.367E-08 8.946E-08 3.314E-07 1.082E-06 2.223E-06 1.232847 3.675E-07 1.707E-08 4.717E-08 1.844E-07 6.286E-07 1.322E-06 1.417475 2.110E-07 8.481 E-09 2.440E-08 1.008E-07 3.600E-07 7.760E-07 1.629751 1.199E-07 4.146E-09 1.243E-08 5.430E-08 2.036E-07 4.507E-07 1.873819 6.752E-08 1.996E-09 6.241 E-09 2.884E-08 1.138E-07 2.590E-07 2.154435 3.763E-08 9.463E-10 3.085E-09 1.509E-08 6.278E-08 1.472E-07 2.477078 2.072E-08 4.407E-10 1.498E-09 7.771 E-09 3.412E-08 8.254E-08 2.848037 1.125E-08 2.007E-10 7.122E-10 3.925E-09 1.824E-08 4.562E-08 3.274549 6.021 E-09 8.91 OE-11 3.305E-10 1.942E-09 9.570E-09 2.481 E-08 3.764938 3.173E-09 3.844E-11 1.494E-10 9.397E-10 4.926E-09 1.326E-08 4.328762 1.646E-09 1.608E-11 6.570E-11 4.443E-10 2.486E-09 6.969E-09 4.977026 8.407E-10 6.521 E-12 2.809E-11 2.053E-10 1.230E-09 3.597E-09 5.722369 4.226E-10 2.561 E-12 1.168E-11 9.265E-11 5.961E-10 1.823E-09 6.579331 2.092E-10 9.745E-13 4.721 E-12 4.084E-11 2.833E-10 9.073E-10 7.564636 1.020E-10 3.592E-13 1.855E-12 1.759E-11 1.319E-10 4.433E-10 8.697490 4.903E-11 1.282E-13 7.088E-13 7.391 E-12 6.027E-11 2.128E-10 10.000005 2.323E-11 4.438E-14 2.634E-13 3.036E-12 2.701E-11 1.003E-10 104 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 10:: 02 .... 10:: LO:: 01 10:: 08 0.01 CGS: Fractile Hazard Curves, 100 Hz ** . .. **** ... * .. ****** ... ' ' ' \ ' \ 0.1 ' \ \ \ \ \ \ . \ . \ \ \ \ \ \ \ \ \ \ \ \ \ PGA(g) ****** L' Figure 2.3.7-1: Control Point Mean and 5th, 16th, soth, s4th, and 95th Percentile Fractile Hazard Curves for Spectral Frequency 5% Damped SA at 100 Hz (PGA) at the CGS Site 105 of 136 10 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure CJ u c "" "CS CJ CJ u )( ..... 0 > u c CJ :J ... ;::; :J c c <t c ... CJ CGS: Fractile Hazard Curves, 25 Hz LO:: 02 ..... .. ..... '** .. ........... . ,** ... --\.1C'.:t* .. **. '**. ' ' . -* :it" "**:,ct c . !Gt" "":*Ct LO:: ' ' . c ' . . --"":*Ct c ' ' . -* 8*'.t" "":tCt c ' . ' ' . ' . ...... t c LO:: Ot. ' . ' . . \ ' ' . \ \ ' *. !Ci:: Cb \ \ \ *. \ \ \ . ' !.(;:_ (it> \ ' ' ' \ ' LO:: 01 ' \ ' \ \ \ \ LO:: 08 . 0.01 0.1 SA (g) Figure 2.3.7-2: Control Point Mean and s'h, 161h, so'h, 841h, and 95*h Percentile Fractile Hazard Curves for the Spectral Frequency 5% Damped SA at 25 Hz at the CGS Site 106 of 136 10 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure LO:: 02 LO:: LO:: 01 LO:: 08 0.01 CGS: Fractile Hazard Curves, 10 Hz 0.1 ' ** . . ,** ... . ..:** ... ' . ,** .. ' . * .. '* .. ' . * .. ' '* .. ' . ,** ... \ \ \ SA (g) . . '** .. . . \ ' .... . . . \ ** .. \ . * .. \ \ *. \ \ \ --\.1C'O:t ... ' ' Figure 2.3.7-3: Control Point Mean and 51h, 161h, 501h, 841h, and 95th Percentile Fractile Hazard Curves for the Spectral Frequency 5% Damped SA at 10 Hz at the CGS Site 107 of 136 10 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 10:: 02 lO:: 10:: 01 10:: 08 0.1 CGS: Fractile Hazard Curves, 5 Hz . ._::* .... .. , .... . :.: .... . . ........ . . ... 'ii: * * ** ' " ' ... " . .. .... ' "\ * .. . .. \.. " . * .. "' ' \ * .. ' . *. \ \ '\. \ , ... \ .... \ \ \ \ \ . ,** .. . \ . \ \. ,\. \ .... '*. \ ' . *. ' \ ... ' .... \ ' ' ... .. ' '\ \ . *. \ \ \ .... SA (g) -\ .. ... Figure 2.3.7-4: Control Point Mean and 51h, 161h, 501h, 841h, and 95th Percentile Fractile Hazard Curves for the Spectral Frequency 5% Damped SA at 5 Hz at the CGS Site 108 of 136 100 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure CJ u c ... "C CJ CJ .., x ..... 0 > .., c CJ :J l: ... ;:;; :J c c <r c ... CJ :2; CGS: Fractile Hazard Curves, 2.5 Hz 10:: 02 --\ .. ... 10:: ' --.. e 10:: 01. !Ci:: (i) l.O:: Cit> LO:: 01 10:: 08 SA(g) Figure 2.3.7-5: Control Point Mean and s'h, 161h, so'h, 841h, and 95*h Percentile Fractile Hazard Curves for the Spectral Frequency 5% Damped SA at 2.5 Hz at the CGS Site 109 of 136 100 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 10:: 02 10:: LO:: 01 10:: 08 CGS: Fractile Hazard Curves, 1 Hz '* ... .... . * .. " ' **. " . ,** .. . ' . **. ' ' '** .. 0.1 . ' . ,** .. '-' . "*. ' ' ' *. . . ' . .. '\. ' . * .. ' '* .. ' . * .. '\. ' '* .. ' . , .... ' ' . * .. ' ' '** .. ' .... \ .\ ' \ * .. \ . *. \ ' ' ... \ . ,** ... ' .... \ ' '\ ' *, \ \ \ .... ' ' ... ' . \. * .. l SA(g) --\1c;,*' --.. e *****
• L' Figure 2.3.7-6: Control Point Mean and 5th, 16th, soth, s4th, and 95th Percentile Fractile Hazard Curves for the Spectral Frequency 5% Damped SA at 1 Hz at the CGS Site 110 of 136 100 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure ., .... c 1.0E-01. 1 1.0E-04 :: .... x w -0 c 1.0E-05 g-ol: ii :I c c <( 1 OE-06 ., ::E 1.0E-07 1.0E-08 0.01 CGS: Fractile Hazard Curves, 0.5 Hz . ..:..*** . .. . . ... --Me;m ..... . .. 'ii; ..... ,** .... . '** ... -*5th Fi.utile . ,*** .. *. le.th f1"Htile ' * ... --F1<11tile 01 . '* .... *. ' ** .. . .. ' ' * .... ' ' ... ' . * .. ' ' ' ** .. ' '* ... ' . * .. ' ' ... -*
• 84th flil( tile ****** 95d1 F1<1ctile ' . ,** ... \ ' . *. \ SA (g) ' * .. ' .... \ ' '. * .... \ 1 ' ... \ .... ' \ ** .. \ . \ * ... ' . * .. \ ' ... \ .... \ *. \ .... \ *._ Figure 2.3.7-7: Control Point Mean and 51h, 161h, 501h, 841h, and 951h Percentile Fractile Hazard Curves for the Spectral Frequency 5% Damped SA at 0.5 Hz at the CGS Site 111 of 136 10 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 2.4 Control Point Response Spectra The control point hazard curves described above have been used to develop uniform hazard response spectra (UHRS) and the ground motion response spectrum (GMRS). The UHAS were obtained through linear interpolation in log-log space to estimate the spectral acceleration at each of the 20 oscillator frequencies for the 10-4 and 10-5 per year hazard levels. The control point UHRS for 10*4 and 10"5 hazard levels, along with a design factor (OF) are used to compute the GMRS at the control point using the criteria in Regulatory Guide 1.208 (USNRC, 2007). Table 2.4-1 shows the UHRS and GMRS spectral accelerations and these spectra which are also plotted in Figure 2.4-1 . Table 2.4-1: 5% Damped UHAS for 10*4 and 10"5 Hazard Levels and GMRS at Control Point for the CGS Site Frequency Mean UHRS [g] Mean UHRS [g] GMRS (Hz) (AFE=104} (AFE=10"5) (g] 100.000 0.2484 0.4288 0.2484 50.000 0.2951 0.5057 0.2951 33.333 0.3471 0.6242 0.3471 25.000 0.3916 0.7238 0.3916 20.000 0.3595 0.6537 0.3595 13.333 0.4341 0.8088 0.4341 10.000 0.4978 0.9638 0.5067 6.667 0.7427 1.4240 0.7501 5.000 1.2160 2.4340 1.2711 3.333 1.3236 2.8030 1.4474 2.500 0.7958 1.7767 0.9078 2.000 0.7360 1.7620 0.8878 1.333 0.5313 1.3565 0.6748 1.000 0.3781 0.9234 0.4634 0.667 0.3089 0.7104 0.3609 0.500 0.1851 0.4552 0.2281 0.333 0.0837 0.1917 0.0974 0.200 0.0435 0.0912 0.0472 0.133 0.0262 0.0540 0.0280 0.100 0.0196 0.0397 0.0207 112 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 3 2.5 2 tiO -c: c '.w IV 1.5 u <( -a. II) 1 0.5 0 0.1 GMRS: CGS, Approach 3, Mean (No Min) ,, ' \ ' \ ' \i I l ' ' ' ' I l , ' ' ' ' I l I l I I \ I \ I \ I \ 3 (10-5) 3 GMRS 3 (10-4) I ', , c:: .. ,-' I I n , , , 1 10 Frequency {Hz) Figure 2.4-1: Control Point UHAS for 10*4 and 10*5 Hazard Levels and GMRS at Control Point for the CGS Site 113 of 136 100 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 3.0 Plant Design Basis and Beyond Design Basis Evaluation Ground Motion The seismic design basis for CGS is identified in Section 3.7 of the Final Safely Analysis Report (EN, 2013b) and other pertinent documents (EN, 1993, 2003. & 2011 ). 3. 1 SSE Description of Spectral Shape The SSE was developed in accordance with Appendix A of 10 CFR Part 100 through an evaluation of the maximum earthquake potential for the region surrounding the site. The original investigation of historical seismic activity in the region is described in the FSAR (EN, 1998 and 2013b). The design response spectrum is based on Newmark-Hall spectrum shape, and hence similar but not identical to Regulatory Guide (RG) 1.60 (NRC. 1973) generic response spectra. However, after the RG 1.60 response spectrum became available, a confirmatory seismic analysis was performed using the RG 1.60 response spectrum scaled to 0.25 g peak ground acceleration to verify that the the structural responses from use of the two spectra were within 10% of each other at almost all locations (see FSAR Section 3.7.1.1 ). Additionally, Section 3.7.2.5 of the FSAR notes that, for primary metal containment, the RPV, the RPV pedestal, and the sacrificial shield wall, the RG spectrum was used for determination of seismic demands and development of in-structure response spectra. The original 5% damped horizontal response spectrum and the RG 1.60 response spectrum are shown in Figure 3.1-1 and tabulated in Table 3.1-1. For analysis of the structures, a set of synthetic time histories was generated and used in the seismic analysis. The response spectra from the time histories enveloped the Operating Basis Earthquake (OBE) response spectra (half of SSE) by a large margin. A typical comparison of the time history response spectrum with SSE spectrum is shown in Figure 3.1-2 (Figure 3. 7-8 of the updated FSAR). The response spectrum method of analysis was used for seismic analysis of the Seismic Category I structures. However, time history analyses of the structures were also performed to develop in-structure response spectra for Seismic Category I systems and components in these structures. 114 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 3.1-1: The 5% Damped Horizontal SSE for CGS and the RG 1.60 with PGA of 0.25 g SSE RG 1.60 Frequency [Hz] SA (g] Frequency [Hz] SA [g] 0.40 0.12 0.10 0.019 2.05 0.60 0.25 0.118 6.10 0.60 2.50 0.783 18.9 0.25 9.00 0.653 100.0 0.25 33.00 0.250 115 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 0.9 0.8 0.7 s 0.6 Cl) u -0.5 u [ en_ 0.4 "C E Ill c 0.3 . . . . . .. . .. . * . **. : **. . . . . .. ... .. /,---\ *** . . . . ' . . . . . . . /1 \ ./°I \ ... .// \ . * .. . . . ...... 1 \ ... *. * * *** RG 1.60 -SSE It) ...... / \ *. . 02 0.1 .... 0 0.1 .. .. .** .* ... ** / .... ** / ... ** / ... **. 10 Frequency (Hz) Figure 3.1-1: The 5% Damped Horizontal SSE for CGS and RG 1.60 with PGA 0.25 g (Source: FSAR Figure 3.7-3; EN, 2013b) 100 Note: RG 1.60 spectrum was used for design of SSCs associated with the primary containment structure. 116 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Ope*at 19 Bass Her zontal Corrpc'le'lt Darrping=0.050 0.56 ....---------------------------------. 0.48 040 0.32 5 !ii ] 0.24 " <I: 0.16 0.08 Synt1et c H story Respc'lse Spect' Jm Desgn Res:Xl'lse SpectrJm 0.00 .....__ ____________________________ ___. o.oo 0.20 o.40 o so o so 100 uo 1.40 uo 1ao 2 oo 220 2 40 NatJral Pe *iod
• Seccnds Figure 3.1-2: The 5% Damped SA of the Time Series Used for Analysis (Source: FSAR Figure 3.7-8; EN, 2013b) 117 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 3.2 Control Point Elevation The CGS site is a soil site with a thickness of about 525 ft. All Seismic Category I structures are supported by a soil layer with embedment depth ranging from 4 ft to 21.5 ft {FSAR Table 3.7-2, EN, 2013b). For seismic analyses of the structures, the SSE control point elevation is defined at the basemat level of the structures attached to soil springs for SSI analysis. Given the previous analysis and the recommendations of the SPID document (EPRI, 2013a) for soil sites, the control point elevation is considered to be at the surface of the finished grade (El. 441 ft). This location has therefore been used to compute the GMRS. 3.3 IPEEE Description and Capacity Response Spectrum Section 5.0 summarizes the Individual Plant Examination of External Events (IPEEE) and IPEEE seismic PAA assessment and provides the plant-level high-confidence low-probability of failure (HCLPF) capacity spectrum for the CGS. 118 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 4.0 Screening Evaluation In accordance with SPID (EPRI, 2013a) Section 3, a screening evaluation was performed as described below. 4. 1 Risk Evaluation Screening (1 to 10 Hz) In the 1 to 10 Hz part of the response spectrum, the GMRS exceeds the SSE. Therefore, CGS screens in for a risk evaluation. 4.2 High Frequency Screening(> 10 Hz) For the range above 1 O Hz, the GMRS exceeds the SSE. The high frequency exceedances will be addressed in the risk evaluation discussed in 4.1 above. 4.3 Spent Fuel Pool Evaluation Screening (1 to 10 Hz) In the 1 to 10 Hz part of the response spectrum, the GMRS exceeds the SSE. Therefore, CGS screens in tor a spent fuel pool evaluation. 119 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 5.0 Interim Actions Based on the screening evaluation, the expedited seismic evaluation described in EPRI (2013b) is planned. Consistent with NRC letter dated February 20, 2014, (NRC, 2014a) the seismic hazard reevaluations presented herein are distinct from the current design and licensing bases of CGS. Therefore, the results do not call into question the operability or functionality of SSCs and are not reportable pursuant to10 CFR 50.72, "Immediate notification requirements for operating nuclear power reactors," and 10 CFR 50.73, "Licensee event report system" .. The NRC letter also requests that licensees provide an interim evaluation or actions to demonstrate that the plant can cope with the reevaluated hazard while the expedited approach and risk evaluations are conducted. In response to that request, NEI letter dated March 12, 2014 (NEI, 2014), provides seismic core damage risk estimates using the updated seismic hazards tor the operating nuclear plants in the Central and Eastern United States. These risk estimates continue to support the following conclusions of the N RC Gl-199 Safety/Risk Assessment (NRC, 201 Ob): Overall seismic core damage risk estimates are consistent with the Commission's Safety Goal Policy Statement because they are within the subsidiary objective of 10*4/year for core damage frequency. The Gl-199 Safety/Risk Assessment, based in part on information from the U.S. Nuclear Regulatory Commission's (NRC's) Individual Plant Examination of External Events {IPEEE) program. indicates that no concern exists regarding adequate protection and that the current seismic design of operating reactors provides a safety margin to withstand potential earthquakes exceeding the original design basis. CGS is a western plant, and hence it was not included in the March 12, 2014 risk estimates (NEI, 2014). In any case, using the Gl-199 Appendix A methodology and based on CGS's most recently reported SCDF value of 4.9x 10-6/year. the CGS's plant-level HCLPF capacity is estimated to be 0.395 g (PGA value). It is noted that the 4.9x 10-6/year SCDF value is the third SCDF update since the original IPEEE Seismic PAA; one SCDF update because of Seismic PRA update in 2004, and two more SCDF updates due to revision of plant models for internal events (EN, 2011 ). Integration of the plant-level fragility (corresponding to 0.395 g PGA HCLPF capacity) with the latest PGA seismic hazard results in revised SCDF estimate as 8.5x 10-7 per year, which is about two orders of magnitude smaller than the 10*4 per year maximum seismic risk threshold considered in Gl-199 (see further discussion below under the heading '"/PEEE and Post-IPEEE Seismic PRA Assessments'}. 120 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Additional information is provided below about the recent 2.3 Seismic Walkdowns. and historical Seismic PRA assessments to demonstrate that: (a) CGS' plant-level HCLPF capacity spectrum well exceeds its seismic design basis spectrum; and (b) CGS plant continues to have a very low seismic risk when the latest PSHA results are factored in. 2.3 Seismic Walkdowns and IPEEE Information The 2.3 Seismic Walkdowns were performed at CGS during 2013 for a broad range of safety related equipment and the walkdown summary is documented in CGS' final walkdown report (EN, 2013a). The NRC, in letter dated March 11, 2014 (NRC, 2014b), determined that sufficient information was provided to be responsive to Enclosure 3 of the 50.54(f) letter. This concluded the NRC's efforts associated with 2.3 Seismic for CGS. The letter reported that CGS had no significant degraded, non-conforming or unanalyzed conditions that warranted any modification[s] to the plant. CGS had no as-found conditions that would prevent SSCs from performing their required safety functions. CGS' 2.3 Seismic Walkdown report also noted that all the IPEEE identified issues have been resolved. Based on the NRC staff's review of the report, the staff concluded that the licensee's identification of plant-specific vulnerabilities (including anomalies, outliers and other findings) identified by the IPEEE program, as well as actions taken to eliminate or reduce them, meets the intent of Section 7 (IPEEE vulnerabilities) of the walkdown guidance. Expedited Seismic Evaluation Process The Expedited Seismic Evaluation Process (ESEP) walkdowns and seismic margin evaluations for CGS will be initiated later in 2015. The seismic demand used in the ESEP will be 2 x CGS SSE in-structure response spectra (ISRS). It is noted that the plant-level HCLPF capacity spectrum well exceeds the plant SSE spectrum (by a factor of approximately 1.5 to 1.7), and the new PGA hazard curve is enveloped by the PGA hazard curve used in the past Seismic PRA assessments. The combination of these two factors suggests that very few expedited seismic equipment list (ESEL) items, if any, will require upgrade/modifications to achieve seismic margin of at least 2 x SSE. IPEEE and Post-IPEEE Seismic PRA Assessments As part of the response to IPEEE-Seismic. CGS performed a full scope seismic PAA assessment in the mid 1990's (EN, 1995). This assessment was performed using the 10,000-year uniform hazard spectrum shape, scaled up to 0.50 g PGA, for use as the RLE spectrum. This ground motion is two times the CGS SSE. In its IPEEE-Seismic report, CGS reported an SCDF value of 2.1x10-5 per year using the PGA hazard curve that was developed in 1994. The IPEEE report was reviewed by the NRG and the identified vulnerabilities were resolved. 121 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure During CGS' license amendment application for license renewal, three subsequent updates were performed on the original IPEEE Seismic PRA. In 2004, several fragility calculations were updated, resulting in a revised SCDF value of 6.67x10"6 per year {the PGA hazard curve from 1994 was the same, albeit extended to cover low annual probabilities of exceedance) (NRC, 201 Oa). In 2007 and 2010, the plant systems models for Seismic PRA and internal events were successively updated, which led to further reduction of SCDF to 5.24x 10-6/year and 4.9x 10-6 per year, respectively {NRC, 2010a; EN, 2011). Section 5.3.2 of NUREG-1437, Supplement No. 47 (NRC. 2012b), documents NRC's review and acceptance of this decreasing trend in SCDF values. It was also noted in this section that the plant-specific PGA hazard curve based on USGS 2008 work was more benign than the PGA hazard curve that was used for CGS' Seismic PRA studies, thus indicating that the SCDF would be even lower than 4.9x 1 o*6 per year if the USGS hazard results were to be used. The Gl-199 methodology was used to estimate the plant-level PGA HCLPF capacity based on the most recently reported SCDF value of 4.9x10"6 per year. The HCLPF capacity was determined to be 0.395 g (about 1.6-times higher than the SSE PGA value), and the corresponding HCLPF Capacity Spectrum is provided in Table 5-1 and shown in Figure 5-1. Table 5-1: CGS Plant-Level HCLPF Capacity Spectrum Calculated Using the 2010 Seismic PAA Results 5% Damped, Frequency Spectral rHzl Acceleration rol 0.500 0.283 0.980 0.608 1.937 0.881 3.214 1.007 4.770 1.034 6.861 0.963 9.720 0.810 19.985 0.522 29.709 0.396 49.765 0.395 122 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 1.2 ........ C) ...... 1.0 c 0 +:i cu L.. Q) 0.8 Q) u u <C cu 0.6 '-.... u Q) c.. "' "C 0.4 Q) c.. E cu c 0.2 .. It) 0.0 0.1 10 Frequency [Hz] Figure 5-1: CGS Plant-Level HCLPF Capacity Spectrum Calculated Using the 2010 Seismic PRA Results 100 As seen in Figure 5-2, the latest PGA hazard curve is lower than the PGA hazard curve considered for CGS's earlier Seismic PRA studies (this is similar to how the old hazard curve exceeded the 2008 USGS hazard curve as well). Using the calculated 0.395 g plant-level (PGA) HCLPF capacity based on the 2010 Seismic PRA and the latest PGA hazard curve developed for this report, the revised SCDF tor CGS is estimated to be about 8.Sx 10-7 per year. As a result of being "screened in" in this report (see Section 4), the new SCDF value will, however, be more rigorously determined by carrying out new Seismic PRA that will be based on new seismic analyses and fragility analyses considering GMRS as the RLE spectrum. In any case, the (rather low) estimated value of 8.5x 10-7 per year is indicative of the plant's low seismic risk profile {and suggests that very few, if any, seismic upgrades will be needed as a result of the new Seismic PRA). 123 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Cll u c C1l 'C QI Cll u >< w .... 0 >-u c QI ::I C" LL ;;; ::I c c <( 1.E-02 1.E-03 1.E-04 1.E-05 1.E-06 1.E-07 1.E-08 0.01 -Old PSHA (NRC, 2010a) -New PSHA (Bechtel, 2015b) 0, 10 Ac:c:e leration (g) Figure 5-2: Comparison of New PGA Hazard Curve with that Used in Earlier CGS Seismic PRAs 124 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 6.0 Conclusions In accordance with the 50.54(f) request for information, a seismic hazard and screening evaluation was performed for CGS. A GMRS was developed solely for the purpose of screening for additional evaluations in accordance with the SPID (EPRI, 2013a). Based on the results of the screening evaluation, CGS screens in for a risk evaluation, a Spent Fuel Pool evaluation, and a High Frequency evaluation as part of the risk evaluation. As discussed in Section 5, previous Seismic PRA evaluations have already shown that the seismic core damage risk is low for CGS, and is expected remain low when new Seismic PRA evaluation is completed. 125 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 7 .0 References Baker, J. W. (2010). Conditional mean spectrum: Tool for ground-motion selection, Journal of Structural Engineering, 137(3), 322-331. Bazzurro, P. and C. Allin Cornell (2004). Nonlinear Soil-Site Effects in Probabilistic Hazard Analysis, Bulletin Seismological Society of America, Vol. 94, No. 6, pp. 2110-2123. Boore, D. M., Joyner, W. B .. & Fumal. T. E. (1997). Equations for estimating horizontal response spectra and peak acceleration from western North American earthquakes: a summary of recent work. Seismological Research Letters, 68(1), 128-153. Darendeli, M.B. (2001 ). Development of a New Family of Normalized Modulus Reduction and Material Damping Curves, PhD Dissertation, University of Texas at Austin. Electric Power Research Institute [EPRI] (1993). Guidelines for Determining Design Basis Ground Motions: methods and guidelines for Estimating Earthquake Ground Motions in Eastern North America, Vols. 1-5, EPRI TR-102293. Electric Power Research Institute [EPRI] (2013a, February 28). Seismic Evaluation Guidance, Screening, Prioritization and Implementation Details (SPID) for the Resolution of Fukushima Near-Term Task Force Recommendation 2.1: Seismic, Report No. 1025287. Electric Power Research Institute [EPRI] (2013b, May 31 ). Seismic Evaluation Guidance: Augmented Approach for the Resolution of Fukushima Near-Term Task Force Recommendation 2.1 -Seismic, Report No. 3002000704. Energy Northwest [EN] (1993). CIVES-1: Seismic/Dynamic Analysis of Structural Components, Richland, WA. Energy Northwest [EN] (1995, June). Individual Plant Examination of External Events -Washington Nuclear Plant 2, Washington Public Power Supply System. Richland. WA. Energy Northwest. [EN] (1998, November). Geology, Seismology, and Geotechnical Engineering Report, Technical Memorandum, TM-2143, Richland, WA. Energy Northwest [EN] (2003, April). Design Specification for Division 202 -Structural and Seismic Design Requirements, Revision 1, Richland, WA. Energy Northwest [EN] (2011, January 28). Letter to U.S. NRC, Columbia Generating Station, Docket No. 50-397, Response to Request tor Additional Information tor the Review of the Columbia Generating Station, License Renewal Application. ADAMS Accession No. ML110330395, Richland, WA. Energy Northwest [EN] (2013a). Columbia Generating Station -Final Seismic Walkdown Summary Report, ADAMS Accession No. ML 13241 A278. 126 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Energy Northwest [EN] (2013b). Columbia Generating Station Final Safety Analysis Report, Amendment 62, Richland, WA. Idriss, I. M., and Sun. J. I. (1992). SHAKE91: A Computer Program for Conducting Equivalent Linear Seismic Response Analyses of Horizontally Layered Soil Deposits, Dept. of Civil and Environmental Engineering, Center for Geotechnical Modeling, Univ. of California, Davis. McGuire, R.K., W. J. Silva, and C. J. Costantino (2001). Technical Basis for Revision of Regulatory Guidance on Design Ground Motions, Hazard-and Risk-Consistent Ground Motion Spectra Guidelines, Prepared for Nuclear Regulatory Commission, NUREG/CR-6728. McGuire, R.K. (2004). Seismic Hazard and Risk Analysis, Earthquake Engineering Research Institute, Monograph MN0-10. Nuclear Energy Institute [NEI] (2014, March 12). Letter to U.S. NRG, Seismic Risk Evaluations for Plants in the Central and Eastern United States, ADAMS Accession No. ML 14083A584. Nuclear Regulatory Commission [NRG] (1973). Design Response Spectra for Seismic Design of Nuclear Plants. Regulatory Guide 1.60, Revision 1. ADAMS Accession No. ML003740207. Nuclear Regulatory Commission [NRG] (2007). A Performance-based Approach to Define the Site-Specific Earthquake Ground Motion, Office of Nuclear Regulatory Research, Regulatory Guide 1.208. ADAMS Accession No. ML070310619. Nuclear Regulatory Commission [NRG] (201 Oa, January). Appendix E to Environmental Report for Operating License Renewal Application, Columbia Generating Station Energy Northwest, Docket No. 50-397 License No. NPF-21, ADAMS Accession No. ML 100250666. Nuclear Regulatory Commission [NRG] (201 Ob, September 2). Safety/Risk Analysis for Gl-199, ADAMS Accession No. ML 100270582. Nuclear Regulatory Commission [NRG] (2012a, March 12). Letter to All Power Reactor Licensees et al., Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Recommendations 2.1, 2.3 and 9.3 of the Near-Term Task Force Review of Insights from the Fukushima Dai-lchi Accident. ADAMS Accession No. ML 12053A340. Nuclear Regulatory Commission [NRG] (2012b. April). NUREG-1437 Supplement 47, Generic Environmental Impact Statement for License Renewal of Nuclear Plants Regarding Columbia Generating Station, Final Report, ADAMS Accession No. ML 12096A334. Nuclear Regulatory Commission [NRG] (2014a, February). Letter to All Power Reactor Licensees et al., Supplemental Information Related to Request for Information Pursuant 127 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure to Title 10 of the Code of Federal Regulations 50.54(f) regarding Seismic Hazard Reevaluations for Recommendation 2.1 of the Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accident, ADAMS Accession No. ML 14030A046. Nuclear Regulatory Commission [NRG] (2014b, March 11 ). Letter to Energy Northwest, Columbia Generating Station -Staff Assessment of the Seismic Walkdown Report Supporting Implementation of Near-Term Task Force Recommendation 2.3 Related to the Fukushima Dai-ichi Nuclear Power Plant Accident (TAC No. MF0109), ADAMS Accession No. ML 14064A311. Pacific Northwest National Laboratory [PNNL], 2014, '"Hanford Sitewide Probabilistic Seismic Hazard Analysis", Report# PNNL-23361, Pacific Northwest National Laboratory, Richland, Washington, November 2014. Silva, W. J., N. A. Abrahamson, G. R. Toro, and C. J. Constantino (1997). Description and Validation of the Stochastic Ground Motion Model, Contract 770573, Report to Brookhaven National Laboratory, Associated Universities, Inc., Upton, New York. 128 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Appendix 2.2A Hanford Sitewide Probabilistic Seismic Hazard Analysis Analytical Process: SSHAC Level 3 The Hanford Probabilistic Seismic Hazard Analysis (PSHA) was conducted using processes that are appropriate for a Study Level 3, as presented in the guidance advanced by the SSHAC in NUREG/CR-6372, Recommendations for Probabilistic Seismic Hazard Analysis: Guidance on Uncertainty and Use of Experts-known informally as the Senior Seismic Hazard Analysis Committee (SSHAC) Guidelines-as well as the detailed implementation guidance provided in NUREG-2117, Practical Implementation Guidelines for SSHAC Level 3 and 4 Hazard Studies. The input to the PSHA to calculate the hazard at the baserock horizon consists of a seismic source characterization (SSC) model and a ground motion characterization (GMC) model. The SSC model defines the location and average rates of all potential future earthquakes of different magnitudes up to the maximum considered physically possible within each source. The GMC model predicts the expected distribution (defined by a logarithmic mean value and an associated logarithmic standard deviation) of spectral accelerations at a site due to a particular earthquake scenario. The PSHA calculations calculate the resulting ground motions from all possible earthquake scenarios and from sampling the full distribution of ground motion amplitudes, to obtain estimates of the total rate at which each level of acceleration is expected to be exceeded at the site. The quantity of data available regarding earthquake occurrence and ground motion generation in any region is never sufficient to unambiguously define the SSC and GMC models. One reason for this is that the completeness of the data, and sometimes its quality as well, are such that different experts assessing the data arrive at diverse interpretations, all of which may be technically defensible. Another reason is that the PSHA calculations will always consider earthquake scenarios for which no data at all are available, such as large-magnitude earthquakes at short distances from the site. These are examples of what is referred to as epistemic uncertainty, which reflects lack of knowledge regarding earthquake processes in general and in the study region in particular. This uncertainty is incorporated in the PSHA calculations. The SSHAC Level 3 process as given in current regulatory guidance defines clear roles and responsibilities for all participants. All technical assessments including the final hazard model and documentation are developed by Technical Integration (Tl) Teams that perform this work in two stages: evaluation and integration. In the evaluation stage, the Tl Teams assess available data, methods, and models both for their inherent quality and reliability, and specifically for their applicability to the region and site under consideration. In the integration phase, the Tl Teams construct logic trees that capture the center, the body, and the range of technically defensible interpretations. The work is conducted under the continuous observation of the Participatory 129 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Peer Review Panel (PPRP), which is charged with performing both technical and process reviews. The PPRP is responsible for reviewing the activities of the Tl Teams to ensure that the project satisfactorily considers available data, methods, and models; captures the center, body, and range of technically defensible interpretations; and adequately documents the technical bases of all decisions. PPRP concurrence that these goals have been met is the key indicator of successful compliance with the requirements of a SSHAC Level 3 process. The Hanford PSHA was conducted from April 2012 to October 2014. The project included a kick-off meeting in April 2012 conducted at PNNL facilities in Richland, Washington, and a tour of the Hanford region. Three workshops were held in Walnut Creek, California. Workshop 1 identified significant seismic hazard issues and data available to address those issues. Workshop 2 reviewed the databases assembled by the teams and discussed alternative models that related to the seismic source or ground motion models for the project. Workshop 3 provided an opportunity for the technical integration teams to present their preliminary SSC and GMC models to the PPRP and receive feedback. Hazard feedback based on hazard calculations using the preliminary models was also provided at Workshop 3. Seven working meetings (four for seismic source characterization and three for ground motion characterization) were held in Oakland, California, over the course of the project to facilitate interaction between the team members; due to family circumstance preventing travel, the first GMC Working Meeting was conducted as a conference call. As is typical of SSHAC Level 3 projects, the total number of participants entailed a large group of about 50 individuals. 130 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Appendix 2.28 Hanford Sitewide Probabilistic Seismic Hazard Analysis PPRP Closure Letter 131 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure November 15. 2014 Mr. Robert W. Bryce Hanford PSHA Project Manager Pacific Northwest National Laboratory 902 Battelle Boulevard P.O. Box 999, MSIN K6-75 Richland, WA 99352

Subject:

Hanford Site-Wide Probabilistic Seismic Hazard Analysis Participatory Peer Review Panel Closure Letter

Dear Mr. Bryce:

Consistent with the requirements for a SSHAC1 Level 3 study, the Hanford Site-Wide (HSW) Probabilistic Seismic Hazard Analysis (PSHA) Participatory Peer Review Panel (hereafter "PPRP" and "Panel") is pleased to issue this PPRP Closure Letter containing our findings with respect to the HSW PSHA SSHAC Level 3 project. The Panel participated in the study following implementation guidance for a SSHAC Level 32 study. The Panel was actively engaged in all phases and activities of the Project's implementation, including final development of the Project Plan and planning of the evaluation and integration activities, which are the core of the SSHAC assessment process. Consistent with regulatory guidance for SSHAC projects, the role of the PPRP is to conduct a review of both the process followed and the technical assessments made by the Technical Integration (Tl) Teams. Accordingly, this letter documents the activities that the PPRP has undertaken in its review of the PSHA, its review of the adequacy of the process followed, and its findings relative to the technical adequacy of the PSHA. PPRP Activities for the PSHA Review The notion of a participatory peer review process entails the continual review of a project from its start to its completion. Thus, proper implementation requires adequate opportunities during the conduct of the study for the PPRP to understand the data being used, the analyses performed for the study, the Tl Team's evaluations and integration of the technical bases for its assessments, and the completeness and clarity of the 1Budnitz, R.J., G. Apostolakis, D.M. Boore, LS. Cluff, K.L. Coppersmith, CA Cornell, and P.A. Morris (1997). Recommendations for Probabilistic Seismic Hazard Analysis: Guidance on Uncertainty and the Use of Experts (known as the .. Senior Seismic Hazard Analysis Committee Report': or "SSHAC Guideline'), NUREG/CR-6372, U.S. Nuclear Regulatory Commission, TIC; 235076, Washington, D.C. 2USN RC (2012). Practical Implementation Guidelines for SSHAC Level 3 and 4 Hazard Studies. NUREG-2117, U.S. Nuclear Regulatory Commission, Washington, D.C. HSW PSHA PPRP C.lo.sure Letter 132 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure documentation. Participatory review also involves opportunities for the PPRP to provide its reviews and comments in written form during the conduct of the project, such that the suggestions and recommendations made by the Panel can be considered by the Tl Teams in a timely fashion prior to completion of the work. Written comments by the PPR P serve to document the review process and provide a vehicle for ensuring that all aspects of the SSHAC process have been adequately conducted. The activities of the PPRP for the HSW PSHA are summarized in the table below, which include written reviews during various stages of the project. Date PPRP Activity April 23, 2012 Kick-off Meeting and Site Tour: All PPRP members attended in person May 25, 2012 Submittal of PPRP written review comments on Kick-off Meeting July 23-27. 2012 SSHAC Workshop No. 1: All PPRP members attended in person as observers August 11, 2012 Submittal of PPRP written review comments on SSHAC Workshop No. 1 September 11, 2012 GMC Working Meeting No. 1a: PPRP representative attended via as an observer September 17-19, 2012 SSC Working Meeting No. 1: PPRP representatives attended in person as observers October 24, 2012 GMC Working Meeting No. 1b: PPRP representatives attended via eleconference as observers December 3-8, 2012 SSHAC Workshop No. 2: All PPRP members attended in person as observers January 3, 2013 Submittal of PPRP written review comments on SSHAC Workshop No. 2 February 18-21, 2013 GMC Working Meeting No. 2: PPRP representatives attended in person as observers February 25-28, 2013 SSC Working Meeting No. 2: PPRP representatives attended in person as observers August 13-16, 2013 GMC and SSC Working Meetings No. 3: PPRP representatives 3ttcndcd via teleconference and in person as observers September 17, 2013 Quaternary Geologic Studies Field Trip: PPRP representative attended n person as an observer November 11-15, 2013 SSHAC Workshop No. 3: All PPRP members attended in person as active participants December 7, 2014 Submittal of PPRP written review comments on SSHAC Workshop No. 3 January 13-16, 2014 SSC Working Meeting No. 4: PPRP representatives attended via eleconference and in oerson as observers January 13-17, 2014 3MC Working Meeting No. 4: PPRP representative attended in person as an observer March 6-7. 2014 PPRP Briefing Meeting on changes made to the GMC and SSC models Workshop No. 3 and on the PPRP written review comments on Workshop No. 3: All PRPP members attended in person as active :>articioants June 16, 2014 Submittal of PPRP written review comments on HSW PSHA Draft Report No. 1 June 18, 2014 Teleconference with Tl Teams to discuss PPRP written review comments on partially complete HSW PSHA draft report: All PRPP members attended HSW PSHA PP RP f.losure I .etter Page2 133 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure June 30, 2014 Submittal of PPRP written review comments on HSW PSHA Draft Repo11 No. 2 and on Tl Teams' responses to PPRP vvritten review comments on PSHA Draft Report No. 1 October 23, 2014 Submittal of PPRP written review comments on HSW PSHA Draft Repol1 No. 3 and on Tl Teams' responses to PPRP vvritten review comments on PSHA Draft Report No. 2 November 11, 2014 Submittal of PPRP written review comments on HSW PSHA Draft Repol1 No. 4 and on Tl Teams' responses to PPRP vvritten review comments on PSHA Draft Report No. 3 November 16, 2014 Submittal of HSW PSHA PPRP Closure Letter The activities listed above are those that were related directly to the conduct of the HSW PSHA and the development of the HSW PSHA report. Prior to the HSW PSHA work activities. the Panel was provided with the Mid-Columbia Project PSHA report and other documents related to Hanford Site seismic hazards. Although those documents provided a useful background for the Panel, this letter does not address these activities, because they lie outside of the SSHAC Level 3 process for the new HSW PSHA. The Panel concludes that its ongoing review and feedback interactions with the Tl Teams during the conduct the HSW PSHA project activities Fully met the expectations for a SSHAC Level 3 study. From the presentation of the plans for conducting the HSW PSHA at the outset of the project to the completion of the HSW PSHA report, the Tl Teams provided multiple and effective communications to the PPRP. Conference calls and written communications allowed the PPRP to fully understand the technical support for the Tl Teams' assessments. The Tl Teams provided written responses to PPRP comments documenting that all comments had been adequately considered during the conduct of the work and its documentation. SSHAC Process Review As explained in NUREG-2117 (USNRC, 2012), the SSHAC process consists of two important activities, described as follows: "The fundamental goal of a SSHAC process is to carry out properly and document completely the activities of evaluation and integration, defined as:

• Evaluation: The consideration of the complete set of data, models, and methods proposed by the larger technical community that are relevant to the hazard analysis.
• Jntegration: Representing the center, body, and range of technically defensible interpretations in light of the evaluation process (i.e., informed by the assessment of existing data, models, and methods)." These activities are essential to any SSHAC Level study and to both refinements to existing studies as well as new PSHAs (such as the HSW PSHA). HSW PSHA PPRP Letter 134 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure During the Evaluation phase of the HSW PSHA, the Tl Teams considered new data, models, and methods that have become available in the technical community since the previous HSW PSHA project was completed in 1995. Importantly, the Tl Teams also evaluated new site-specific data and methods for conducting site-response analysis, which is included as part of the HWS PSHA project as guidelines that ensure that there is a proper interface between the reference-rock hazard and the site-response analyses that will be conducted by the engineering consultants. The Panel concludes that the Tl Teams conducted an adequate evaluation process and that this process has been sufficiently documented in the PSHA report. During the Integration phase of the project, SSC and GMC models and site-response methodological guidance were developed for purposes of the HSW-specific PSHA. SSHAC guidelines require that the technical bases for the PSHA model be documented thoroughly in the PSHA report. The PSHA document demonstrates the consideration by the Tl Teams of the existence of seismic-source and ground-motion data and models that have become available since the previous HSW PSHA model was developed. The site-response guidelines entailed developing shear-wave velocity profiles for the Saddle Mountain Basalts and conducting a site-response analysis in light of models and methods that have been identified by the U.S. Nuclear Regulatory Agency and used in recent analyses for nuclear facilities. Documentation in the PSHA report confirms that the GMC Tl Team was aware of the applicable site-specific data, as well as models and methods for building the profiles, accounting for uncertainties, and carrying out the site-response analysis in order to develop these guidelines. Based on the review of the Evaluation and Integration activities conducted by the Tl Teams, as well as the documentation of these activities in the PSHA report. the PPRP concludes that the SSHAC process has been adequately conducted. SSHAC Technical Review The role of the PPRP in the review of the technical aspects of the project is specified in NUREG-2117 (USNRC, 2012) as follows: "The PPRP fulfills two parallel roles, the first being technical review. This means that the PPRP is charged with ensuring that the full range of data, models, and methods have been duly considered in the assessment and also that all technical decisions are adequately justified and documented. The responsibility of the PPRP is to provide clear and timely feedback to the Tl/TFI and project manager to ensure that any technical or process deficiencies are identified at the earliest possible stage so that they can be corrected. More commonly, the PPRP provides its perspectives and advice regarding the manner in which ongoing activities can be improved or carried out more effectively. In terms of technical review, a key responsibility of the PPRP is to highlight any data, models or proponents that have not been HSW PSHA ?PRP C:losure J .etter 135 of 136 Page 4 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure considered. Beyond completeness, it is not within the remit of the PPRP to judge the weighting of the logic-trees in detail but rather to judge the justification provided for the models included or excluded, and for the weights applied to the logic-tree branches." Consistent with this USNRC guidance, the PPRP reviewed at multiple times during the project the Tl Teams' analyses and evaluations of data, models, and methods. These reviews included conference calls, post-workshop meetings, written comments, and the review of drafts of the PSHA report. Through these reviews, the PPRP communicated feedback to the Tl T earns regarding data and approaches that did not appear to have been considered, suggestions for methods being used within the technical community, and recommendations for ways that the documentation could be improved to include more discussion of the technical bases for the assessments. Examples of PPRP feedback regarding the technical aspects of the project can be found in the written comments provided at various times to the Tl Teams. The Tl Teams were responsive to the questions, comments, and suggestions made by the PPRP relative to the technical aspects of the project. Therefore, the Panel concludes that the technical aspects of the projects have been adequately addressed. Conclusion On the basis of the PPRP's review of the HSW PSHA, the Panel concludes that both the process and technical aspects of the assessment fully meet accepted guidance and current expectations for a SSHAC Level 3 study. We appreciate the opportunity to provide our review of the project. Sincerely, HSW PSHA PPRP Members Kenneth W. Campbell Chair William U. Savage HSW PSHA PPRP Closure Letter ... Brian S.-J. Chiou rfadLfar J. Carl Stepp 136 of 136 William R. Lettis Page 5 Focus Area Ouestions!T opics for DCPP Public Meeting 4128 In addition to providing a general overview of the SSC and GMC SSHAC Reports and March 2015 50.54(f) response for DCPP, please provide additional clarification on the following topics. Seismic Source Characterization 1. Summarize the key data used to constrain the slip rate of the Hosgri fault, including associated uncertainties. 2. Clarify how elements of the thrust/reverse interpretation for the San Luis Range Thrust are incorporated into the SSC. 3. Clarify how the rupture models are derived from the fault source geometry models. 4. Summarize the methodology used to define the equivalent Poisson rates. Ground Motion Characterization 1. Provide additional detail on the criteria used for the selection of the candidate ground motion prediction equations (GMPEs) for development of the common form median ground motion models for DCPP. Specifically, please elaborate on the basis for including GMPEs based on datasets other than NGA-West2. 2. Provide additional detail on development of the common functional form used to fit the candidate GMPEs. Specifically, please discuss how model parameters such as depth to Vs=1 kmls and 2.5 km/s (which are present in some of the candidate GMPEs) are accounted for in the functional form. 3. Provide additional detail on the approach for weighting the selected common form models as well as the criteria used to verify the physicality of the final models. 4. Provide additional detail on how the continuous distribution for total sigma (ass) was developed by combining the between-event and within-event aleatory variabilities. Site Response 1. Section 2.3.2.1 of the 50.54(f) submittal states that shear modulus and damping curves are not directly applicable to DCPP since analytical modeling is not used and that linear site effects are implicitly included in the empirical GMPEs for Vs30=760 mis. However, the NGA-West2 database has a limited amount of data for sites with Vs30 near 760 mis and for earthquakes with magnitudes and source-to-site distances similar to those dominating the hazard for DCPP. Please provide additional information on how these limitations in the NGA-West2 database are accounted for in the site response model for DCPP. 2. Section 2.3.6 of the 50.54(f) submittal describes the development of the site term for DCPP. For the calculations of between-event residuals, provide additional information on the criteria used to determine the appropriate distance range(+ and -Rrup) to the sample station. Please discuss the sensitivity of this distance range on between-event residual values. Please provide an example calculation that uses site-specific values to determine the values for including the epistemic uncertainty in the source term.

Focus Area Topics for CGS Public Meeting 6/2 In addition to providing a general overview of the SSC and GMC SSHAC Reports and March 2015 50.54(f) response for CGS. please provide additional clarification on the following topics. Seismic Source Characterization 1. Summarize the information used to constrain the slip rates on the YFTB faults, including: a. Methodology used to evaluate fault slip from topography including associated uncertainties in the ages and offsets. b. Rationale for excluding thin skinned seismo-tectonic models. c. How potential effects of surficial erosion were accounted for in the use of an average topographic profile to represent structural relief in individual faults. d. Bases for excluding listric fault geometries or potential for backthrust structures in structural relief model. 2. Summarize the information use to define the areal seismic source zones, including: a. Bases for zone boundaries b. Seismicity rate calculations. smoothing, and how uncertainty was captured as part of logic tree. c. Bases for Mmax distributions Ground Motion Characterization 1. Provide additional detail on the process used to define the target site kappa values and their uncertainties, including the rationale for logic tree weightings. 2. Provide additional detail on the Vs-Kappa corrections applied to the scaled backbone GMPEs, including: a. Rational for not applying a kappa correction for the subduction zone GM Ms b. Comparison of the Vs-kappa scaled median GMPEs and NGA-West 2 models c. Whether any observational data from the region was used to assess the kappa corrected GMPEs 3. Provide additional discussion regarding bases tor bump seen at T =0.1 sec in the mean tau values for the NGA-West2 models and the decision for smoothing through this peak in developing single-station sigma. Site Response 1. Provide additional detail regarding the characterization of the uncertainty in the site response analyses. specifically: a. Bases for only a single profile for the upper 525 ft b. Bases for two Vs profiles and their associated weights for the SMB stack c. Thickness of the interbed deposits including their lateral extent d. Adequacy of EPRI and Peninsular curves for covering range of nonlinear behavior for the Pasco Gravel e. Bases for randomizing the small strain damping for the basalt layers in the SMB stack in view of the uncertainty already incorporated into the determination of the site kappa 2. In view of the relatively high shear wave velocities(> 760 mis) and high confining stresses in the interbed layers, provide the rationale for not considering linear behavior of these materials and instead using a single sand curve which demonstrates significant non-linear behavior. 3. Provide additional detail regarding the decision not to implement a minimum site amplification value and the effect of this decision on the development of the uncertainty in the site amplification function as well as on the final hazard curves for the site. Focus Area Ouestions!T opics for DCPP Public Meeting 4128 In addition to providing a general overview of the SSC and GMC SSHAC Reports and March 2015 50.54(f) response for DCPP, please provide additional clarification on the following topics. Seismic Source Characterization 1. Summarize the key data used to constrain the slip rate of the Hosgri fault, including associated uncertainties. 2. Clarify how elements of the thrust/reverse interpretation for the San Luis Range Thrust are incorporated into the SSC. 3. Clarify how the rupture models are derived from the fault source geometry models. 4. Summarize the methodology used to define the equivalent Poisson rates. Ground Motion Characterization 1. Provide additional detail on the criteria used for the selection of the candidate ground motion prediction equations (GMPEs) for development of the common form median ground motion models for DCPP. Specifically, please elaborate on the basis for including GMPEs based on datasets other than NGA-West2. 2. Provide additional detail on development of the common functional form used to fit the candidate GMPEs. Specifically, please discuss how model parameters such as depth to Vs=1 kmls and 2.5 km/s (which are present in some of the candidate GMPEs) are accounted for in the functional form. 3. Provide additional detail on the approach for weighting the selected common form models as well as the criteria used to verify the physicality of the final models. 4. Provide additional detail on how the continuous distribution for total sigma (ass) was developed by combining the between-event and within-event aleatory variabilities. Site Response 1. Section 2.3.2.1 of the 50.54(f) submittal states that shear modulus and damping curves are not directly applicable to DCPP since analytical modeling is not used and that linear site effects are implicitly included in the empirical GMPEs for Vs30=760 mis. However, the NGA-West2 database has a limited amount of data for sites with Vs30 near 760 mis and for earthquakes with magnitudes and source-to-site distances similar to those dominating the hazard for DCPP. Please provide additional information on how these limitations in the NGA-West2 database are accounted for in the site response model for DCPP. 2. Section 2.3.6 of the 50.54(f) submittal describes the development of the site term for DCPP. For the calculations of between-event residuals, provide additional information on the criteria used to determine the appropriate distance range(+ and -Rrup) to the sample station. Please discuss the sensitivity of this distance range on between-event residual values. Please provide an example calculation that uses site-specific values to determine the values for including the epistemic uncertainty in the source term. Focus Area Topics for CGS Public Meeting 6/2 In addition to providing a general overview of the SSC and GMC SSHAC Reports and March 2015 50.54(f) response for CGS. please provide additional clarification on the following topics. Seismic Source Characterization 1. Summarize the information used to constrain the slip rates on the YFTB faults, including: a. Methodology used to evaluate fault slip from topography including associated uncertainties in the ages and offsets. b. Rationale for excluding thin skinned seismo-tectonic models. c. How potential effects of surficial erosion were accounted for in the use of an average topographic profile to represent structural relief in individual faults. d. Bases for excluding listric fault geometries or potential for backthrust structures in structural relief model. 2. Summarize the information use to define the areal seismic source zones, including: a. Bases for zone boundaries b. Seismicity rate calculations. smoothing, and how uncertainty was captured as part of logic tree. c. Bases for Mmax distributions Ground Motion Characterization 1. Provide additional detail on the process used to define the target site kappa values and their uncertainties, including the rationale for logic tree weightings. 2. Provide additional detail on the Vs-Kappa corrections applied to the scaled backbone GMPEs, including: a. Rational for not applying a kappa correction for the subduction zone GM Ms b. Comparison of the Vs-kappa scaled median GMPEs and NGA-West 2 models c. Whether any observational data from the region was used to assess the kappa corrected GMPEs 3. Provide additional discussion regarding bases tor bump seen at T =0.1 sec in the mean tau values for the NGA-West2 models and the decision for smoothing through this peak in developing single-station sigma. Site Response 1. Provide additional detail regarding the characterization of the uncertainty in the site response analyses. specifically: a. Bases for only a single profile for the upper 525 ft b. Bases for two Vs profiles and their associated weights for the SMB stack c. Thickness of the interbed deposits including their lateral extent d. Adequacy of EPRI and Peninsular curves for covering range of nonlinear behavior for the Pasco Gravel e. Bases for randomizing the small strain damping for the basalt layers in the SMB stack in view of the uncertainty already incorporated into the determination of the site kappa 2. In view of the relatively high shear wave velocities(> 760 mis) and high confining stresses in the interbed layers, provide the rationale for not considering linear behavior of these materials and instead using a single sand curve which demonstrates significant non-linear behavior. 3. Provide additional detail regarding the decision not to implement a minimum site amplification value and the effect of this decision on the development of the uncertainty in the site amplification function as well as on the final hazard curves for the site. Jackson, Diane From:Jackson, Diane Sent:22 May 2015 09:03:37 -0400 To:Akc, Jon;John Stamatakos;Miriam Juckett (mjuckett@swri.org);Sticvc, Alice;Plaza-Tolcdo, Meralis;Stova11, Scott;Weaver, Thomas;Munson, Clifford;Hil1, Brittain;Li, Yong;Giacinco, Joseph;Stirewalt, Gerry;Graizer, Vladimir;Devlin-Gill, Stephanie;Heeszel, David;Walsh, Lisa Cc:Kock, Andrea;Burke, John

Subject:

FY I Focus Arca Topics for Columbia Public Meeting (draft 2) Attachments: Focus Area Questions for DCPP Public Meeting 4-17 DSEA.docx, Focus Area Topics for CGS Public Meeting (draft 2).doc.:x

Dear R2.1 WUS reviewers:

Columbia is the next public meeting. It is scheduled for June 4 in the afternoon. Just as we did with Diablo focus areas, I want to share the Columbia focus areas with all of the team for information and consistency. Please take a look at them. I have re-included Diablo focus areas for completeness and convenience. Palo Verde focus areas are coming along and are next. Public meeting June 9. After the public meetings, our next milestone is Questions by the end of summer. Please target mid-August. The SRB will be reviewing the questions for consistency and level of detail. This system worked well for CEUS and in the ESEP interim evaluation reviews which are on-going. For a data point comparison, of the CEUS plants, about seven received questions. I would not be surprised if all 3 WUS sites have questions due to the complexity of the review. However, keep in mind, these are 50.54(f) reviews. We will use softer wording in the questions. Our goal is to make sure we understand what they did and have sufficient information to make a judgment if they adequately characterized the site and that the hazard is suitable to develop the SPRA. I understand this is still not a small task; it is a large task. However, as we discussed, the level of review should not be to the depth of a licensing review. Regards -Diane g)Uuie Jacll,jon, Chief Geosciences and Geotechnical Engineering Branch 2 (RGS2) Division of Site Safety and Environmental Analysis ( DSEA), Office of New Reactors ( N RO) US Nuclear Regulatory Commission +1301-415-5641; office: T-7 D3; mail stop: T-7 F3 NRC -One Team -One Mission 1 5 ---------.-------------.-----------, I Columbia r .. ! 1.2 .. GMRS, Tbl 2.4-1 1.1 ; SSE, Tbl 3.1-1 / __ -\-.,....-------1_0 -*RG 1.60, 0.25g * -;-\ .,_ ___ _ c; ***** HCLPF, Tbl 5.1 I .*. *. \ -0.9 . ----.---,-----O.B 1 -*IPEEE, 2x SSE / _ __ _ cu ** l . ' *' I... 0 7 .:* ** I-. --------;-. 8 0.6 -----' J 0.5 :*.*------* " 'ta:: , -1: ---i 0.4 -:-. ----* 0.3 :-: ----* 0.2 ----* 0 1 J ,,., . .,,.' ,)_...,. ---0.0 :.--0.1 ------....... ::mr:: ******* ______ ...,. ------1.0 10.0 100.0 Frequency (Hz) l'rotecting l>eople and the r:uvirou1ncnt Near-term Task Force Recommendation 2.1 (R2.1) Seismic Hazard Evaluation Energy Northwest Columbia Generating Station Public Meeting References and Protecli**g People and the Enviromnent Logistics

• Public Meeting Agenda -ML 15142A452
• NRC Presentation Slides -MLXXXXXXXX
• Licensee Presentation Slides -MLXXXXXX
• Licensee Hazard Report -ML 15078A243
• Screening and prioritization results -ML 151138344
• Meeting Feedback Form (request from njd2@nrc.gov)
• Meeting Summary to be issued within 30-day 2

\-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent Meeting Purposes

• Gather additional information based on early identification of areas where additional technical information will support the staff's review
• Gain a better understanding of how the licensee conducted their evaluation 3

\-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent Outline

• Overview of Recommendation 2.1 -Response to NRC 50.54(f) letter
• Screening and Prioritization results
• N RC approach to seismic hazard characterization reviews for Western US (WUS) sites
• Review schedules and timeline 4

\-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent Seismic R2.1 Process Ensures Clarity, Consistency, and Informed Regulatory Decisions PHASE 1 INFORMATION GATHERING STAGE 1 Interact with Industry on Hazard and Risk Evaluation Guidance CELIS Licensees submit Site Response (9/2013 & 3/2014) Screened-in plants complete Expedited Interim Evaluation (CEUS:12/31/2014;WUS:1 /2016) and Risk Evaluation (Group 1: 6/2017) NRC reviews Risk Evaluation -----------------------------* ,----------------PHASE 2 DECISION-MAKING N RC makes Regulatory Decisions as Needed *Safety Enhancements

• Backfit Analysis *Modify Plant License -----------------5 Seismic Screening and -. .. m, ... ,,. ... ..... ro._., Prioritization resu Its
• NRG Letter issued for WUS sites on May 13, 2015 (ML 151138344)
• Columbia has screened-in for seismic risk evaluation and limited scope evaluations -Review Group 1 plant
• No immediate safety issues identified
• Information supports safety assurance allowing additional time to complete the seismic risk evaluation 6 NRC Review of SSHAC -. .. m, ... ,,. ... ..... ro._., Studies for WUS Sites
• Did SSHAC process follow NRC guidance?
• How effective was the peer review panel?
• Have all applicable data been considered?
• Were data uncertainties identified and considered?
• Was an appropriate range of applicable models considered?
• How were models selected and weighted in the analysis?
• How were models assembled into the PSHA? 7

\-* U.S.NRC NRC Review of Source Mode Is for WUS Sites

• How were seismic sources identified? -Geologic mapping -Geophysical observations -Earthquake catalog
• How were seismic sources characterized? -Geometry (location, length, dip) -Range of magnitudes -Faulting style (normal, reverse, strike-slip) -Slip rate and recurrence models -Complex rupture scenarios 8

\-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent NRC Review of Ground Motion Models and Site Response for WUS Sites

• Do final ground motion models capture a reasonable range of alternative models?
• How were sources of uncertainty captured in model development?
• How were ground motion models adjusted for local site geology?
• Does site response analysis cover a reasonable range of alternative soil/rock properties?
• How was uncertainty in site response analysis incorporated into final probabilistic hazard curves? 9 Timeline * '1 March 2015: WUS Hazard Submittals * '1 May: Screening and prioritization letter * '1 May/June: Public meetings
• Late summer/early fall: Staff questions
• December: GMRS suitability Letter
• January 2016: ESEP Interim Evaluation
• April 2016: ESEP review response
• Summer 2016: Document Hazard review
• June 2017: Risk Evaluation submittal (Grp 1) 10

\-* U.S.NRC Break for NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent Staff Alignment

• 15 -20 minute planned break for NRC staff alignment to support meeting wrap-up
• Meeting to resume at 3:00pm (Eastern) or 12:00pm (Western) 11 Opportunity for Public Protecli**g People and the Enviromnent Questions or Comments
• Additional Questions? Please ask us at: JLD _PublicResource@nrc.gov 12

\-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent List of Acronyms

• CEUS -Central and Eastern United States
• ESEP -Expedited Seismic Evaluation Process (for Interim Evaluation)
• GMRS-Ground Motion Response Spectrum
• NRC-U.S. Nuclear Regulatory Commission
• NPP-Nuclear Power Plant
• NTIF -Near-Term Task Force
• PSHA -Probabilistic Seismic Hazard Analysis
• SFP -Spent Fuel Pool
• SMA -Seismic Margins Analysis
• SPID -Screening, Prioritization, and Implementation Details SPID
• SPRA -Seismic Probabilistic Risk Assessment
• SSC -Structures, Systems and Components
• SSHAC -Senior Seismic Hazard Analysis Committee
• SSE -Safe Shutdown Earthquake
• SPID -Screening, Prioritization, and Implementation Details
• WUS -Western United States 13

\-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent Backup Slides 14 Additional WUS Protecli**g People and the Enviromnent Seismic Hazard Reports Public SSHAC Report

• Hanford Sitewide (PSHA including Columbia Generating Station) http://www.hanford.gov/page .cfm/Official Do cuments/HSPSHA 15

\-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent Guidance Documents

• Two main guidance documents proposed by industry and endorsed by the N RC
• Screening, Prioritization, and Implementation Details (SPID) -Submitted by EPRI on November 2012 -Endorsed by NRC on February 15, 2013 -EPRl-1025287 (ML12333A170)
• Seismic Evaluation Guidance: Augmented Approach (aka Expedited Approach) -Submitted by EPRI on April 9, 2013 -Endorsed by NRC on May 7, 2013 -EPRl-3002000704 (ML 13102A 142) 16

\-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent Hazard Development Expedited Interim Evaluations Risk Evaluations Higher Priority Lower Priority Hazard Analyses Expedited Interim Evaluations 2012 I I Schedule for Seismic Hazard and Risk Evaluations 2013 2014 2015 2016 2017 2018 2019 2020 CEUS '1

• wus '1
• All plants I CEUS I mods I
• 1 wus mods Only plants I with new
• I Group 1 I I Risk Evaluations '1 Staff acknowledgement to use GMRS for risk evaluation seismic hazard exceeding design basis Group 2 Group 3 (as needed) e Staff Assessment or response -17 Summary of Recent Seismic Hazard Investigations at Diablo Canyon Power Plant The 2015 seismic hazard analysis is different from analyses in 2014 and earlier -Considers likelihoods that ground motions will occur (earlier assumed will occur) -Uses new approach to model how energy moves from source to beneath site -Uses more site-specific information to calculate ground accelerations at surface The 2015 seismic hazard is higher than calculated in 2011 and 2014 analyses -Better understanding of site-specific conditions -Consideration of earthquakes from linked faults (e.g., Shoreline+San Simeon+Hosgri) -Improved models for how energy travels from source to site New data from site-specific investigations is used extensively in 2015 seismic analysis -Studies directed by CA Assembly Bill 1632 -Results presented in PG&E Central Coastal California Seismic Imaging Project Report -Reviewed by the Independent Peer Review Panel and recent SSHAC program Diablo Canyon is safe to operate while additional risk investigations are completed in June 2017 -New GMRS does not exceed the well-documented safety margins for Diablo's design -Safety margin analyses from Long-term Seismic Program reviewed by NRC in 1991 -Sufficient detail to provide NRC assurance that Diablo Canyon can operate safely Chronology of Key Seismic Hazard Issues at Diabfo Canyon 1969 Construction Permit for Unit 1, design basis 0.4g Double Design Earthquake 1971-77 Characterization of Hosgri Fault offshore DCPP 1973 N RC issues Apdx A to 1 O C FR Part 100 (SSE-G DC2), and RG 1 . 61 (damping) 1977 PG&E applies for Operating License, includes Hosgri evaluation in design 1984 NRG issues SSER 7, grants OL w/ Lie Condition for Long-Term Seismic Program 1988 PG&E issues LTSP report, includes seismic PRA and margins assessment 1991 NRC extensively review L TSP report, no change to design basis, issues SSER 34 1992-2006 Cooperative seismic research program with USGS 2008 Shoreline fault identified from offshore earthquake alignment 2008 PG&E uses LTSP methods to show Shoreline bounded by previous analyses 2009 NRG RIL-09-01 deterministic analyses confirm PG&E conclusions 2011 PG&E issues detailed Shoreline fault report, ground motions bounded previously 2011-12 Two nonconcurrences on Inspection Reports for seismic hazard analyses Feb 2012 NRG RIL-12-01, additional deterministic analyses confirm PG&E conclusions March 2012 NRC issues 50.54(f) letter to all licensees. DCPP compare DDE to GMRS 2013-14 D PO on DCPP seismic hazard issues: N RC refutes conclusions Sept 2014 PG&E issues updated Shoreline report, conducts operability evaluation Dec 2014 NRC inspects PG&E operability evaluation, confirms seismic safety at DCPP Mar 2015 PG&E submits 50.54{f) response Tl Team I PM notes Hazard Sensitivity
• Make the tornado plots consistent for DCPP and PVNGS Directivity
• Directivity -Hazard sensitivity
• Currently only for the original distribution of hypocenters
• Justify the use of a single directivity model -Show the hazard sensitivity with the new hypocenter distribution that is more concentrated on unilateral -Apparent sharp changes in the contours
• Check the maps of the parameterized model -Does it still have the sharp edges?
• Demonstrate the the contours are appropriate Median Models
• Common form The break point in the mag scaling may be related to an important seismological parameter and could be treated as a random variable
• Demonstrate that the current approach adequately captures the range of models that would be found if the break point was treated as a random parameter DCPP
• Justify the mag range (MS-m8) used for fitting the GMPEs with a common model
• Would adding a point at M4.5 make a difference to the covariance? PVNGS
• Demonstrate that the upper mag range (M7) used for fitting to the common form is adequate if SSC has magnitudes up to M7.4?
• May be alternative ways to capture the ZTOR dependence without introducing a 0,1 indicator variable, but getting a better fit on the FW side Median Models
• Generating common form models -Improve documentation
• Document that the COV was doubled to broaden the distribution for generating the 15,000 models
• But used interpolated models which are correlated
• The doubling of the variance approximates the effect of the correlation on the covariance. -Justify not adding the additional epistemic uncertainty to the COV for generating the 15,000 models
• Show a PSA histogram (slice at one scenario) with COV and 2 times the COV -Compare to the distribution that would result using the COV (not doubled) but adding the AV epistemic uncertainty. -Does the doubling of the COV capture that range?

Median Modes

• CDF checks -Justify the use of the representative model rather than the suite of models in a region.
• Check if the CDF sensitive to the use of the representative model rather than all of the models that fall into a region
• 5-95 range plots -Show the range from the original GMPEs, in addition to full range from GMPEs with +-2sigma -Show insensitivity to cell boundaries Logic tree weights
• Justify (explain) why the three point distribution has weights of 0.2, 0.6, 0.2 rather than 0.185, 0.63, 0.185 as given in referenced paper.

Weights on approach for sammon's maps weights

• Document what was being checked in CDF plots for constraining the 60-40 weights on resid approach and likelihood approach -Is it the slope, the 5% and 95% or other metrics? -Show the fractiles of the original GMPEs (w/o unc)
• Improve justification for the weights on the data sets and prior. -More important for PVNGS -Think about likelihood for European data using fixed sigma but with more variable data -DCPP hazard is not very sensitive to these weights Tau model
• What is the justification for using the smoothed CV14 tau in computing the average rather than using the raw unsmoothed values?
• Explain how the effect of the bump in tau will be captured somewhere in the process of getting the site-specific ground motions -Add examples showing how the bump moves to site terms if RE for both site and event are included -Document how this should be addressed in the site response Phi Models
• Justify not using the PEGASOS phiSS models -Why are they only used for comparisons?
• Documentation of phi -Make clear that all data is used to get the site terms, but a subset of the deltaWs is used for the PHISS (based on M,R)
• Justify why there should be a reduction (change in slope) in PHISS from 5-10 sec -Consider smoothing through this.

PhiSS and PhiSP-R

• Justify using a constant phiSS with mag when the 5 NGA models used for this region all have mag dependent phi Limited mag range and dominated by larger magnitudes for this source. Some NGA models have constant phi for M>5.5 for M>6
• Address SSC changes Changes to the SSC zonation affect the classification of one event used for the path This revision is now final
• Expand documentation for how the COV of phiSP-R is computed Justify why only four periods between 0.2 and 2 sec were used and not more as used for phiSS The values at T=0.2 and 0.5 are different and the fit from 0.5 to 1. sec is influenced by the value at T=0.2 sec. Justify why this captures the period dependence in the main range of interest {T>0.5 sec)

PhiSS (greater AZ)

• Revise terms on logic tree -"constant" should be "mag independent"
• Revise phiSS versus mag plots to drop the M4 to MS points as these were not used
• Justify why the apparent mag dependence from MS to M6 is not considered as evidence for a mag dependent phiSS
• For the comparison to PhiSS from Swiss study, document that the Swiss study did not address the bias due to sample size Spatial correlation effects on tau and phi
• Not currently included in documentation -Model is not fully developed -Will not be formally included as a branch, but consider putting extra weight on the upper branch of total sigma Sigma Sensitivity
• DCPP -Modify plots to use symbol size to represent weights consistent with PVNGS plots
• PVNGS -Sensitivity to tau for regions 1, 2,3 need to be checked -Make sure the numerator has the hazard from all source (include the mean hazard from the other region)

Phi logic tree

• Greater AZ phi -Justify why the European data is given lower weight for phi, but higher weight for the median -Justify the mag-independent phiSS for full range of magnitudes M>S.
• If there is a mag dependence, this approach may underestimate the phi for MS.

Other Issues Missed?

• If PPRP has noted other deficiencies (unclear documentation or inadequate justification), provide short letter to Tl team by Friday Jul 25, or it will not be addressed for the Aug 11 draft report
• Lumpy, discretized, hazard sensitivity results for Palo Verde median models Evaluation of Alternative Directivity Models for DCPP Introduction The simplified directivity model by Watson-Lamprey (2015) was used to conduct the hazard sensitivity studies. The Watson-Lamprey model is intended to be a simplified version of the Chiou and Youngs (2014) directivity model that is part of their GMPE (called CY14). To incorporate directivity into hazard calculations, the direct method is to integrate over the hypocenter location for each rupture and add the directivity effects on the median ground motion for each hypocenter location. This leads to a range of median ground motion values for a given rupture (magnitude, dimension, location) but with different hypocenters on the rupture plane. The Watson-Lamprey model simplifies the application to hazard by pre-computing the range of median ground motions for the distribution of hypocenter for a given rupture and site location. The range of directivity factors for the median is parameterized by a mean value and the standard deviation. This allows for a faster implementation in the hazard code because there is no need to include the integration over hypocenter location in the hazard code. The cost of this simplification is that is may not capture all of the features of the CYl 4 model for the specific site/source geometry for DCPP. This sensitivity study compares the hazard at DCPP using the full CY14 directivity model and the simplified Watson-Lamprey directivity model. Hypocenter distribution The distributions of the along-strike and down-dip locations of the hypocenter are based on the distributions shown in Figures 1 and 2 shown below. For this sensitivity study, the following hypocenter distributions are used: For strike-slip earthquakes, the "Appendix D" distribution is used for the strike distribution and the CY2008 distribution is used for the down-dip distribution. For reverse earthquakes, the uniform distribution is used for the along-strike distribution and the CY2008 distribution is used for the down-dip distribution. For both strike-slip and reverse earthquakes, the hypocenters are restricted to be at least 10% of the rupture length from the ends of the rupture as recommended by Chiou and Spudich (2013) (Sec 6.3, page 90). In the hazard code, these distributions are discretized into 10 locations along strike and 3 locations down dip. The discrete probabilities for these locations are given in Table 1.

Hazard code implementation The CY14 directivity model was implemented into PG&E hazard code (Haz43b). This hazard code was previously set up to include directivity by including integration over the hypocenter location along strike and down dip. In general, implementing the CY14 directivity model into haz43b is straight-forward with one exception: computing the mean OPP parameter for a given rupture. The CY14 directivity model uses the difference in the OPP at the site of interest from the mean OPP for sites located at the same RRuP for a given rupture. This requires finding a set of sites that are at the same RRuP and represent uniform sampling of the locations. There was not an obvious simple way to find a uniform sample of sites at a given RRuP from an arbitrary rupture. Therefore, a brute force method was used to implement this into Haz43b. For each rupture, a uniform grid of sites was generated along the rupture (sampling both sides) with a grid step size of 0.5 km. The RRur was computed for each site and those sites with an RRuP that was within 1 km of the RRuP for the DCPP site were selected for averaging the OPP. There is probably a faster way to do this, but this method was the easiest to implement at the cost of computation time. Sensitivity results The CY14 directivity model was developed for the CY14 GMPE. Therefore, the hazard was computed using the CY14 GMPE. Three alternative directivity models are used to compute the hazard: 1) No site-specific directivity added (e.g. !:illPP = 0) 2) The CYl 4 directivity model is added using the hypocenter distributions listed in Tables 1 and 2. 3) The simplified Watson-Lamprey directivity model is added The hazard was computed for a period of T=3 sec. At a period of 3 sec, the Hosgri is the main contributor to the hazard: the Hosgri contributes 60% of the hazard at 1 E-4 and 75% of the hazard at lE-5. Therefore, the first sensitivity study is based on the impacts on the hazard from the Hosgri fault source. A second sensitivity study that includes the directivity effects using the CY14 model for all sources could not be completed in time for inclusion in this report, but it will be included in the final version of this sensitivity study. To show the effect of two directivity models, the ratio of the hazard with directivity to the hazard without directivity is shown in Figure 3. In the lE-3 to lE-4 hazard level range, the CY14 model and the Watson-Lamprey model give similar factors of 1.00 to 1.10. At lower hazard levels (lE-6), the models become more different with the CYl 4 model showing increasing directivity effects at lower hazard levels while the Watson-Lamprey model show a decrease to back to unity. From this comparison, the TI team concludes that the directivity effects based on the simplified Watson-Lamprey model will give reasonable results in the lE-4 to lE-5 range, but it underestimates the directivity effects at the lE-6 hazard level. The decision to exclude directivity effects based on the small effect on the hazard based on the sensitivity studies that used the Watson-Lamprey simplified model is justified for hazard above the lE-5 level, but it should be checked further for the lower hazard levels. The hazard results are used to generate the ground motion response spectra (GMRS) which uses the lE-4 and lE-5 UHS. For this application, the Watson-Lamprey simplified model gives reasonable results. References Chiou, B.S.-J., Spudich P. (2013). The Chiou and Spudich NGA-West2 directivity predictor DPP, PEER Report 2013/09, Pacific Earthquake Engineering Research Center, University of California, Berkeley, CA. Chiou, B.S.-J., and Youngs, R.R. (2014). Update of the Chiou and Youngs NGA Model for the Average Horizontal Component of Peak Ground Motion and Response Spectra, Earthquake Spectra, Vol. 30(3), 1117-1153, DOI: 10.1193/072813EQ5219M. Watson-Lamprey, J. (2015). Capturing Directivity Effects in the Mean and Aleatory Variability of the NGA-West 2 Ground Motion Prediction Equations, Pacific Earthquake Engineering Research Center PEER Report (in preparation). Table 1. Discrete distribution used for hypocenter location along strike Hypocenter Probability for Probability for location along Strike-slip Reverse strike (ratio to ruptures ruptures rupture length) 0.10 0.13 0.1 0.19 0.10 0.1 0.28 0.09 0.1 0.37 0.09 0.1 0.46 0.09 0.1 0.54 0.09 0.1 0.63 0.09 0.1 0.72 0.09 0.1 0.81 0.10 0.1 0.90 0.13 0.1 Table 2. Discrete distribution used for hypocenter location down dip Hypocenter Probability for Probability for location down Strike-slip Reverse dip (ratio to ruptures ruptures rupture width) 0.25 0.15 0.15 0.50 0.35 0.35 0.25 0.50 0.50 1.4 1.2 0.4 a.z 0'------------' 0 0 1 0 2 0 3 0.4 0.5 0 6 0 7 0 8 0 9 I Hypoccniral X Rati() -CY2008 -Appendi* D -Uni1orrn Figure 4.1 Hypocenter distributions along strike for strlke*slip ruptures. 1.8 1.6 1.4 1.2 E 1 .. '50.8 G. 0.6 0.4 0.2 o.._ ________ __, 0 0.1 0.2 0.3 0.4 0.5 0.6 0 7 08 0.9 1 0()wn Dip Ratio -CY2008 -Uniform Figure 4.2 Hypocenter distributions down dip for strike-slip ruptures. Figure 1. Alternative hypocenter distribution models for strike-slip earthquakes given in Watson-Lamprey (2015). The top frame gives the distribution along strike and the bottom frame gives the distribution down dip. (Figure from Lamprey, 2015) 1.4 1.2 1 ..... ii .li 08 e (I_ 0.6 0.4 0.2 O'------------' 0 0.1 0.2 0.3 0.4 0.5 0.5 0 7 08 0.9 1 Hypucenlr*I X R*lio -CY200B -umrmm Figure 4.3 Hypocenter distributions along strike for reverse ruptures. 1.8 1.6 1,4 1.2 ,., 1 z £as 0.6 0.4 0.2 o..__ ________ _... 0 0. 1 0.2 0.3 0.4 0.5 0.6 0. 7 0.8 0.9 1 Down Dip Ral*O -CY20CJB -umro1m Figure 4.4 Hypocenter distributions down dip for reverse ruptures. Figure 2. Alternative hypocenter distribution models for reverse earthquakes given in Watson-Lamprey (2015). The top frame gives the distribution along strike and the bottom frame gives the distribution down dip. (Figure from Watson-Lamprey, 2015) 2 (.) 1.8 7i 1.6 I-..... 0 -1.4 *5 1.2 ..... 0 ..... 1 0 -..... 0 t5 0.8 <'1 LL Q) <'1 0.6 (.) Cl) -e 0.4 <'1 J: 0.2 0 1 E-2 ---------WL Dir I no Dir (CY14 GMPE) CY14 Dir I no Dir (CY14 GMPE) 1E-3 1E-4 Annual Hazard 1E-5 _/ 1 E-6 Figure 3. Hazard ratio for directivity effects for the Hosgri fault (using the full Hosgri SSC model) with the CY14 GMPE for both the median and the standard deviation. Comment Response Table Comment Location in Text PPRP Comments Tl Team Responses Number 1. General comments The report lacks terminological and stylistic consistency. This deficiency A comprehensive check of the terminology and style was affects its readability and sometimes renders meanings ambiguous. Just done for all chapters and all appendices. as examples: the report uses inconsistent abbreviations for the NGA West2. inconsistent symbols for some variables (e.g. tau, Tau.<), inconsistent names to refer to data sets. Please edit for overall consistency of style, terminology and notation throughout the report, including main chapters and appendices. 2. General comments Acronyms, technical terms, and individual variables are not consistently A check was made that the acronyms are all defined at defined when they are first used. Please provide a list of acronyms, a list the first use and that they are consistently used of variables. and a list of terms that the reader can refer to when throughout the chapters and appendices needed. Please also define these acronyms, parameters. and terms the first time that they are used in the report, after which they need not be defined again as long as the reader can refer to a list as necessary. For example, ASK14. BSSA14, CB14, and CY14 are used throughout the report and are defined by their full references sometimes and only their acronyms at other times. Please provide the full references the first time they are used, include them in the list of acronyms, then only reference them by their acronyms after that. 3. General comments There is very inadequate cross-referencing between chapters and Detailed cross referencing is added between chapters. and between the main chapters and the appendices. While there is no between chapters and appendices objection to putting technical detail in the appendices. each report chapter must be coherent and self-contained in and of itself in the sense that any appendices that it relies on must be incorporated by explicit references, with sufficient connective text to be readable and understandable. When results from such an appendix are referenced, please cite the relevant section and/or figure or table number within the appendix. 4. General comments Please consider streamlining the presentation by absorbing some The following appendices have been absorbed into the of the short appendices with few figures, or that are redundant with main report Appendix L, M. and N. other report chapters or appendices. into the appropriate main chapters. In that case, only those appendices that are lengthy, present complex methods or analysis, or contain a large number of figures or tables, could be retained as separate entities. 5. General comments There are many places throughout the report where there are The text is reviewed to identify this type of statements, and statements of what was done but not why it was done. It is a additional text explaining why it was done is added. requirement of the SSHAC process that the justification and basis for each decision by the Tl Team be fully documented. Please provide a description of the Tl Team's assessment and evaluation that was done to arrive at the methods, models, and decisions that form the bases for the statements and models presented in the report and appendices. 6. General comments Because the 3-point discretization scheme for representing a continuous A new Appendix has been added that provides the distribution was frequently used in the report, please provide a brief background and references for three point distributions used discussion of its origin. properties. and accuracy, so that that discussion by the Tl Team This appendix include the three point can be used as a reference throughout the report. distributions for both normal and chi-squared distributions.

7. General comments Please consider providing a special treatment of the scaled Chi-square Same as response to General comment 6 distribution in the report. It is invoked frequently, and such a treatment could serve as a reference throughout the report, and also could make related chapters more accessible to the full range of readers. As noted later in this review. the presentation of the topic in Chapter 13 is unmotivated, lacks clarity. and its equations are made impenetrable by numerous notational errors. 8. General comments The term "proponent moder is used a number of times in the report in The confusion occurs because we have used the term ways that seem to be inconsistent with the term's usual meaning in a "proponent model" for both the existing models and new SSHAC study. In the SSHAC context, the term is usually reserved for models developed by the Tl Team or under the direct models presented by proponent experts, for subsequent evaluation by direction of the Tl Team. The text has been revised to only the Tl Team. In each instance, if the intended usage corresponds to the use "proponent model" for previously existing models that SSHAC standard, please ensure that it is clear why. If it does not, it is are evaluated by the Tl Team. New models developed by important to avoid the term, as it is misleading. the Tl Team or under the direction of the Tl Team are called "Tl Team models 9. General comments It is appropriate to discuss the center, low and high values of variables All Tl T earn evaluations of weights were moved to the when a model is first discussed, but please consider consistently chapters describing the logic trees. deferring discussion of the weights to the chapter that discusses the related logic tree. The current draft is inconsistent in this regard. CHAPTER 7 GMC Models for the Sigma 10. Section 7 .1 , Page 7-Please note that Anderson and Brune (1999) was cited but not included The missing references have been added 1, Paragraph 1. Line 4 in the references section of this chapter 11. Section 7.1, Page 7-Please clarify that q>ss and q>so-R are alternative (mutually exclusive) Text revised to better explain the relation between PhiSS 1, Paragraph 1. Line 6 models for PVNGS (associated with non-path-specific median and path-and PhiSP-R specific median models, respectively, and also please reference appropriate sections from chapter(s) on median motion. 12. Section 7. 1 , Page 7-Please replace "/" with "and" to avoid any confusion that q>ss I 'l>s*-R is a Text revised as recommended 1, Paragraph 1, Line 7 ratio of these two terms. 13. Section 7. 1 , Page 7-For uniformity of coverage, please include in the outline in this section a Reference to chapter 13 added to chapter 7 to explain how 1, Paragraph 1, Line reference to chapter 13 where the combining and resampling of tau and the phi and tau models are simplified to a total sigma logic 8-9 phi is discussed. tree 14. Section 7.1, Page 7-Please consider whether Miller and Rice (1983) is correc11y cited here. New Appendix P addresses 1he use of a 1hree poin1 sample 1, Paragraph 1. Line 9 Miller and Rice propose moment-preserving sampling of continuous of the distribution and clarify if the quotation is appropriate or distributions at Gaussian points. Is this reference relevant to the not. approach actually used in this report? 15. Section 7. 1 , Page 7-It is not clear whether the term "sigma is meant to represent a generic The text was modified to avoid the use of generic "sigma". 1, Line 10 term for all standard deviations or to represent a specific standard Sigma will only be used for the total standard deviation (e.g. deviation. Please define the term "sigma" the first time it is used and Chap 13) include it in the list of terms 16. Section 7.1, Page 7-It would be helpful to also give a guide here to the relevant appendices The key appendices (L, M, N) for the phi and tau are 1, End of first covering sigma topics that are referenced in 1his chapter. Please note in incorporated into chap 7 (see General comment 4) paragraph particular that the division of the (jlss and (jls*-R details between two different appendices (N and L, respectively) tends to obscure their close relationship, and any such confusion would be mitigated by an overview discussion of the sigma appendices at this point in the report. 17. Section 7.1.1, Page Please explain that the site-to-site variability that is removed in order to This is addressed in the chapter dealing with the application 7-1, 1st Paragraph of estimate single-station sigma needs to be included as uncertainty in the guideline. A reference to this guideline added to Chap 7. Section, Line 4 site-specific site-response analyses, whether they are empirical or analytical.

18. Section 7.1.1, Page Please include citable references to the PSHA studies mentioned in this Missing references were added 7-1, 1st Paragraph of sentence (PEGASOS Refinement Project, Thyspunt Nuclear Siting Section, Last Project. BC Hydro PSHA Project. and Hanford PSHA Project) sentence 19. Section 7. 1 . 1 . Page Please justify your criterion of using "a minimum of 3 recordings". Why is The difference in the min number of recordings is based on 7-2, First Paragraph, a higher number of recordings not needed (especially given the use of a the use of the terms (for the variance or for the estimate). Line 6 minimum of 5 recordings per station in the Cjlso*R analysis for PVNGS The basis for the selection of the min number is addressed in described in Appendix L)? Chap5 20. Section 7.2.1, Page Please define the term 'central value' (is it mean. median, or something The text was revised to replace "central" value will a more 7-2, First paragraph, else?). precise term Line 1 21. Section 7.2.1, Page Please cite appropriate references for ASK14, BSSA14, CB14 and Missing references were added 7-2, Paragraph 1, Line CY 14, as well as for the errata of the Akkar et al. (2014) and Bindi et al. 2-3 (2014) papers. 22. Section 7.2.1, Page Please explain whether there was an attempt to obtain the residuals or This was not done because applying a mixed effect would 7-2, Paragraph 1, Line databases, from which residuals could be calculated, for the Graizer require changing other parts of their model that affect the 4 (2014) and Idriss (2014) GMPEs in order that estimates of phi and tau median (and the authors judgments), thus requiring the could be derived before these models were rejected. authors to re-evaluate their model. The reason for not using these two models to estimate the standard deviations have been added to the Chao 7 text 23. Section 7.2.1, Page Please provide a reference to the section where plots of the magnitude The recommended cross referencing is added to the text 7-2, Paragraph 1, Line distribution of the Akkar et al. (2014) and Bindi el al. (2014) databases 5 are shown. 24. Section 7.2.1, Page Regarding the expression "it was assessed," please indicate who did the The text revised to clearly indicate that this is a Tl T earn 7-2, Paragraph 1, Line assessment (i.e., the Tl Team) in order to avoid confusion Please also evaluation. 9 ensure that similar references to the writers of the report are replaced with references to the Tl T earn throughout the report and appendices, unless someone else did the assessment, in which case they should be clearly identified. Moreover. use of the word "may" implies that it is not known and not assessed. If such an assessment was done, please delete the word "may" to indicate that the Tl T earn knows this to be the case. 25. Section 7.2.1, Page Some studies have developed separate sigma and median models. in The two models were not rejected for the median values. but 7-2, Paragraph 1, Line which case the model-specific sigma model of each GMPE is not they were rejected for the tau and phi values based on less 9 important. Please explain why the Akkar et al. (2014) and Bindi el al. reliable metadata. The point was clarified in the text. (2014) GMPEs were rejected on the basis of their sigma models and why the Tl T earn decided to use model-specific sigma models instead of a sigma model that is independent of the median model. 26. Section 7.22 1. Page Introducing the term "bump" is stylistically questionable (as The text was revised to refer to the narrow band increase in 7-2, Section title (and acknowledged by the use of quotes) and not as clear as simply calling the tau values at high frequencies. general comment on the feature a peak (which is unambiguously a feature with a local section) maximum). and leads lo inconsistency, as sometimes it is called a peak later in the report (e.g .. first line of next paragraph). Please consider whether a more conventional term such as "peak" (without quotes). used consistently in the subsection heading and thereafter, would be suitable here. 27. Section 7.2.2.1, Page Please explain why ASK14 and CY14 "chose to smooth through these Sections rewritten to better discuss the evaluations and the 7-2, Paragraph 1, Line variations" in the period-dependence of tau technical bases for the assessments 7 28. Section 7.22 1. Page Please provide a citable reference to the point-source simulation A reference to the approach used by Youngs was added. 7-3, Paragraph 1, Line methodology used by Bob Youngs. Because this work forms the 1 theoretical justification for removing the peak in tau around 10 Hz, please consider adding a more in-depth description of this work either to this section or as an appendix.

29. Section 7.2.2.1, Page Please explain why the particular values of median stress parameter (50 The results are not sensitive to these values. The text is 7-3, Paragraph 1, Line bars) and its logarithmic standard deviation (0.5) were selected and why revised to explain how the values were selected and the 2 the stress parameter is modeled with a lognormal distribution. Please sensitivity to the assumed values. also indicate whether the results are sensitive to the selection of these particular values. 30. Section 7.22 1. Page Please explain what logarithmic standard deviation is. The logarithmic standard deviation refers to the standard 7-3, Paragraph 1, Line deviation of the log values. The text is revised to make this 3 clear. 31. Section 7.22 1. Page Please ensure that the term "site kappa" has been defined in the report The term "site kappa" is replaced with" kappa at the 7-3, Paragraph 1, Line prior to its use in Chapter 7 and included in the list of terms. individual sites" 4 32. Section 7.2.2.1, Page Please explain why the particular values of median site kappa (0.035 See response to comment 29 7-3, Paragraph 1, Line sec) and its logarithmic standard deviation (0.3) were selected and why 5 site kappa is modeled with a lognormal distribution. Please also indicate whether the results are sensitive to the selection of these particular values. 33. Section 7.22 1. Page Please add text to explain what the "WUS amplification factor is and The text is revised to include a definition of the amplification 7-3, Paragraph 1, Line what effect it is supposed to model (also ensure that the acronym WUS factor as it is used in this simulation method 5 has been defined when it is first used and included in the list of acronvmsl. 34. Section 7.22 1. Page This sentence implies that the site amplification from the Boore and The frequency independence referred to the random 7-3, Paragraph 1, Line Joyner (1997) site profile is frequency independent; whereas, it is highly adjustment from the frequency depended site amplification 5-7 frequency dependent. Please clarify whether it is the site factor itself or factor. Text revised to make this clear the variability in this site factor that is frequency-independent. Please explain why the particular values for median site amplification variability (0) and its logarithmic standard deviation (0.4) were selected and why site amplification is modeled with a lognormal distribution. 35. Section 7.22 1. Page Please describe how you obtain the residual standard deviations from The simulated data are fit to a simple form using random 7-3, Paragraph 1, simulation data. effects. The text revised to explain the regression process Line 7 used to compute the phi and tau from the simulations 36. Section 7.2.2.1, Page Please also state that this methodology does not explain the "dip" in tau Text revised to discuss the dip at T=0.4 sec and that this is 7-3, Paragraph 1, at around T = 0.4 sec. not explained by the simulations Line 8 37. Section 7.2.2.1, Page Please describe the frequency-dependent site factor that was used. Text modified 7-3, Paragraph 1, Line 9 38. Section 7.2.2.1, Page Please consider providing a clear statement of what variable was Text modified 7-3, Paragraph 2, Line correlated with kappa, and how this correlation was determined. in the 1 2nd set of simulations 39. Section 7.2.2.1, Page Please consider whether the phrase "tau is a measure of the average The text was revised to clarify that tau is the standard 7-3, Paragraph 2, differences in ground motion from earthquake to earthquake" should be deviation of the event terms Line 4 more precisely formulated to reflect the fact that tau is a parameter that measures the dispersion of deviation (from average). 40. Section 7.2.2.1, Page Please revise this sentence to make ii clear that the total variance in The text was revised to explain the partitioning of the kappa 7-3, Paragraph 2, kappa is partitioned into two components: the event-to-event variation of variance Line 7 median site kappa of an event and the within-event variation of site kappa at 50 sites. 41. Section 7.22 1. Page Please clarify whether you mean "average" or "median". The term "average" is appropriate here. It does not depend 7-3, Paragraph 2, Line on median versus mean. 11

42. Section 7.2.2.2, Page Please rewrite paragraph for greater precision and clarity. The first two First sentence rewritten 7-4, Paragraph 1, sentences of this section read as though the previous section of the Lines 1and2 report was not there. Furthermore, they are imprecise. NGA-West2 analyses (not models) found the tau peak cited. The second sentence can be read as implying that the NGA-West2 studies attributed the peak to the kappa correlation, which they did not 43. Section 7.222. Page Please provide a reference to the section where the removal of the 10 A cross reference was added 7-4, Paragraph 1, Line Hz peak is discussed and the outcome presented 3 44. Section 7.2.2.2, Page Please further articulate this recommendation to include, for example, This is part of the site response -hazard inference Chapter. 7-4, Paragraph 1, Line how site response should be conducted in order to be consistent with the A reference to this interface added in the Chap 7 4 decision to remove the 10 Hz peak. 45. Section 7.23, Page Please use consistent language throughout the report and appendices to The text was revised to use consistent terminology for the 7-4, Paragraph 1, 2nd refer to the set of GMPEs selected for the tau study (currently they are set of selected GMPEs and 3rd Lines: called, e.g., "considered models," "five considered GMPEs," "the 5 GMPEs," "the underlying five models" elsewhere in Chapter 7). 46. Section 7.2.3, Page The cited figures, 7.2.3-2 and 7.2.3-3, are missing. Numbering has been fixed (it referred to the figures in the 7-4, second to last subsequent Section) line of section 47. Section 7.2.4, Page The word "significantly" represents a subjective judgment by the Tl sentence has been removed 7-5, Paragraph 2, 2nd Team. Please replace "significantly" with a more quantitative description Line of the change of tau with period and discuss why this change is not considered to be significant. 48. Section 7.2.5, Page On the right hand side, the subscript "w" is incorrectly included. Typo corrected 7-5, First Paragraph of section, Equation 7.2.5-1 49. Section 7.2.5, Page Please justify why the within-model variability of tau from CY14 can be This is addressed in the new appendix P (see general 7-5, 1st Paragraph of considered representative of the other four selected models. Also comment 6) Section, 2nd provide a citable reference to the result from Bob Youngs referred to Sentence here, if one is available. Otherwise provide documentation of that analysis and its results in the chapter or an appendix. 50. Section 7.2.5, Page The phrase "smoothed using a constant across all periods" is misleading sentence replaced 7-5, Paragraph 1 of if the intent was that the average over all periods was done to produce a section, 5th line after period-independent model. Please clarify. eqn 7 2 5-t 51. Section 7.25, Page The averaging process doesn't "account" for the slated fact, but rather sentence replaced 7-5, Paragraph 1, Line makes it irrelevant, since the Tl Team elected to use a period-6 after eqn 7.2.5-1 independent model. Please clarify this point. 52. Section 7.2.5, Page Please provide lexl to explain clearly why the distribution is "scaled, addressed in the new appendix P (see general comment 6) 7-5, Paragraph 2, Line how the scale factor c and degree of freedom k are derived (e.g., are 5 they set to obtain a simultaneous match to mean and variance of tau squared?). and why this distribution is appropriate for modeling the uncertainly in tau squared. 53. Section 7.25, Page Please describe what value of tau squared should be entered into the addressed in the new appendix P (see general comment 6) 7-5, Paragraph 2, equations for c and k. This special value of tau characterizing the Second 10 Last Line distribution should be given a distinct notation to differentiate ii from the random variable tau whose distribution is being characterized.

54. Section 7.2.5, Page Please provide additional justification and basis for the magnitude-The mag-dependent tau is based on the mean tau shown in 7-6, Paragraph 1, dependent tau model shown in Figure 7.2.5-5. Figure 7.2.3-1. A cross reference to this figure is added lo Sentence 3 this section of the text 55. Section 7.3 1, Page The hazard sensitivity studies from elsewhere in the report that support The deaggregations have been added to Chap 4 to indentify 7-6, Paragraph 1, the specific magnitude and distance ranges selected as "important" for the mag & dist ranges that are important to DCPP. A cross Lines 4-5 DCPP should be referenced here, with section and figure numbers cited. reference to these chap 4 plots is added to this section. Please also provide a more quantitative description of what is meant by "important", since this term represents a subjective judgment of the Tl Team. 56. Section 7.3 1, Page Please rewrite this sentence to clarify its meaning, and also provide a A Reference to the PEGASOS study is added. The text was 7-6, Paragraph 1, reference for the results cited from an external project. revised to explain why the PEGASOS models are not used Final sentence directly. 57. Section 7.3 1, Page Please add references to parts of the report where results of the Tl A cross reference to the Tl Team evaluations is added. A 7-6, Paragraph 2 Team's evaluations are presented (including a reference to a figure figure is added to the report to show that the phiSS values supporting the statement that "the calculated <i'ss values were consistent are similar among the 4 NGA-West2 models. among the 4 NGA-West2 models"). 58. Section 7.3.1, Page Please add precise references to the report and/or appendix section(s) Cross references to the new appendix P is added to this 7-6, Paragraph 3 of where the coefficient of variation estimate of 0.12 is derived (for section section, Line 4-7 example. "Appendix M, Section M 3 and Figure M.7"). where use of chi-squared distribution of <pss is explained and justified, and where the details of model derivation and assessment are available. The general catchall referral to Appendix M in the last sentence of the paragraph is insufficient in this regard. 59. Section 7.3.1, Page Regarding the statement that " ... values were smoothed over period: The smoothing is a fit to a bilinear model. An explanation of 7-7, Paragraph 2 on please clarify nature of smoothing or provide reference to section of how the smoothing is done is added to the text page, Line 1 report that does so. 60. Section 7.3.1, Page Please provide the justification and basis for the proposed high and low The high and low values are from the confidence bounds of 7-7, Last paragraph of values of q>ss and provide missing Table 7.3.1-3. the estimates. A cross reference to the new App P is added. section, last sentence The missing table is added 61. Section 7.3 1 1. Page Please add text to describe the findings regarding dependence on included as NEW appendix K 7-7, Paragraph 1, Line distance, style-of-faulting, and Vs30. Please also add text (here or in 1 Chapters 1tand12) to justify the Tl Team's decision to not model such dependence in the logic tree for sigma. 62. Section 7.3.1.1, Page A reference to Workshop 3 (Appendix G) is not sufficient. If this work See comment 61 7-7, Paragraph 1, Line was done outside the SWUS project, please provide references to 2 publications or peer-reviewed reports. If this work was done within the SWUS project, then please add more documentation or cite sections of the report where such documentation is included. 63. Section 7.3 1 1. Page Please also summarize where in Chapter 7 the models for <Pss and their The table with the results was missing. This table is added 7-7, Paragraph 2 coefficients can be found. (see comment 60) 64. Section 7.3 1 1. Page Please further justify the inclusion of the magnitude-independent (jlss Done -the M -independent CA model has been replaced by 7-7. Paragraph 2 branch (with the CA data set) in light of the clearly observed magnitude-a M dependent model with break at MS.5 dependence shown in Figure M.4. 65. Section 7.32, Page The part of the sentence after the comma that starts with "a subsets of We have removed "a subsets of' from the text 7-7, 1st Paragraph of the single-station seems to be disconnected from the first part of the Section, 2nd sentence. Please restructure this sentence to clarify its meaning. Sentence 66. Section 7.3.2, Page Please indicate that Figure 7.3.2-t shows <pss values for the European Entire sentence has been restructured 7-7, 2nd Paragraph of dataset, which is not obvious from the text. Section, 1st Sentence

67. Section 7.3.2, Page Please provide reference to specific section(s) or appendices of the A reference to the new appendix P which addresses this 7-8, 1*1 paragraph on report where this figure for COV(<pss) is derived. including explanation topic is added this the text page, Line 2-4 on and justification of the method based on chi-square distribution. page 68. Section 7.3.2, Page Please explain why data for only five spectral periods are shown in Only 5 periods are used because the Taiwan data available 7-8, 1 paragraph on Figure 7.3.2-2. to the project was limited to these five periods. The figure is page, Line 4 revised to also show the phiSS at other periods without the Taiwan data 69. Section 7.321. Page Please explain why the CA dataset was not used to develop a Addressed in Chapters 11 and t2. The logic trees show all 7-8, 1st Paragraph of magnitude-dependent <pss model for PVNGS as it was for DCPP. the branches. also associated to models not used (in this Section, 1st Sentence case zero weight). Same nodes are provided in the figures for DPP and PVNGS, but different weights are applied as appropriate 70. Section 7.3 3, Page Please provide further explanation and basis of the statement "No data The text is revised to explain the treatment of the CB 14 data. 7-8, 2nd Paragraph of in the distance range of 200 to 400 km is available in the CB14 dataset". The residuals are computed using the event terms provided Section, 1st Sentence CB 14 did use data from distances of 80-500 km to fit average anelastic by the developers. The CB14 model events terms are only attenuation terms, but did not include these data in the derivation of for the short distances. These event terms may not be event terms and within-event standard deviations. applicable to 200-400 km. Therefore. the CB14 residuals were not used for this step 71. Section 7.3.3, Page Please provide reference to specific section(s) or appendices of the A reference to the new appendix P which addresses this 7-8, 3rd Paragraph of report where this figure for COV(</lss) is derived, including explanation topic is added this the text Section, 2nd and justification of the method based on chi-square distribution. Sentence 72. Section 7.3.3, Page Please consider deferring any discussion of logic-tree weights and their The discussions on logic tree weights is removed from this 7-9 1st Paragraph, 1st justification until the report sections that present the logic-trees. Other chapter and placed into the appropriate logic tree chapter Line parts of Chapter 7 present the models and their uncertainty and not the assessment of logic-tree branch weights, which requires additional justification; so introduction of weights in this section appears somewhat inconsistent with the rest of the chapter. 73. Section 7.4.1, Page Please explain why all four NGA-West2 GMPEs can be used for the The PhiSP-R is estimated from the GMPEs and the AZ data 7-9 1st Paragraph of assessment of (jlsP-R. whereas CB 14 was excluded from the assessment (new residuals computed), whereas for the PHISS, the Section, 1st sentence of <Pss. within-event residuals provided by the developers are used. Because we compute the residuals for PhiSP-R, we can use all four of the models. The text is revised to explain this point. 74. Section 7.4 1, Page Please justify why only three spectral periods are sufficient to define the Due to the bandwidth of the oscillator. the change of PHISP-7-9 1st Paragraph of period-dependence of single-path term (/)sP-R. given that the observed R for nearby periods is small. From the hazard calculations Section, 2nd dependence of this standard deviation for other spectral periods might from previous studies (chap 4), the dist CNMEX sources Sentence deviate from that shown in Figure 7.4.1-1. contribute significantly to the hazard at T>1 sec. For this evaluation, we captured the range of periods using T=0.5. T=1. and T=2 sec. (Note, the T=0.2 sec point was removed in the figure as this is not important to hazard and does not help the understanding) 75. Section 7.4 1 . Page Please provide a discussion of why the 0.2 s result is unstable. The T=0.2 sec value is not needed and was removed 7-9, 1st Paragraph of Section, 3'" sentence 76. Section 7.4.1, Page Please provide justification for the use of a chi-square distribution and A reference to the new appendix P which addresses this 7-9 1st Paragraph of provide a reference to this distribution and the related equations. Please topic is added this the text Section, 4rd Sentence also provide a reference (Le., the section in Appendix M) for the selection of a COV of 0.17; the explanation in the 4th Sentence requires additional *ustification.

77. Section 7.4.1, Page The related materials provided in Appendix Lare little more than a The phi_sp-r model is an empirical derived standard 7-9, 1st Paragraph of repeat of these sentences. The required technical details and basis for deviation whose mathematical framework is described in Section, 4*h sentence the proposed models for 4>sP-R are lacking. Please provide sufficient section 7.4.1. We disagree that there in inadequate technical and remainder of documentation so report satisfies SSHAC Level 3's requirement of being bases for this approach. paragraph clear, transparent, and complete. Any references to the appendix should be specific with respect to sections, tables, figures. 78. Section 7.5, Page 7-In addition to presenting the comparison, please discuss the important Additional discussion of these plots and how they show that 9, Paragraph 1 findings and how they agree (or disagree) with the logic-tree models range of the models is added to the text proposed by the Tl T earn 79. Section 7.5, Page 7-Please supply a reference for the Hanford project magnitude-dependent The reference to the Hanford project is added 9, Paragraph 1. Line 8 <pss. 80. References, Page 7-Please update Abrahamson et al. (2014) with journal volume and pages. Reference was corrected 10, Item 3 81. References, Page 7-Please add reference for published erratum to Akkar et al. (2014) and Reference was corrected 10, Item 4 cite both original paper and erratum in text. 82. References. Page 7-Ang and Tang (2007) is not cited in text. Please remove from references Reference was removed 10, Item 7 unless a citation is added to text. If it is cited, please cite by page number, and also include publisher location in the reference section entry. 83. References. Page 7-Please include an additional reference to the published erratum to Bindi Reference was added 10. Item 9 et al. (2014) and cite both references in the text. 84. References, Page 7-Please update the Boore et al. (2014) and Campbell and Bozorgnia Reference was corrected 10, Items 11 and 12 (2014) references to include the specific journal volume and pages. 85. References. Page 7-Please update the Chiou and Youngs (2014) reference to include the Reference was corrected 10. Item 14 specific journal volume and pages. 86. References. Page 7 -Please provide the page numbers or paper number for the Graizer Reference was corrected 11. Item 1 (2013) reference. 87. References, Page 7 -Please update the Idriss (2014) reference to include the specific journal Reference was corrected 1 t, Item 2 volume and pages. 88. References, Page 7-Please list the publisher's name and location for the Rodriguez-Marek Reference was corrected 11 and Cotton (2011) reference. 89. Tables 7.3.1-1, 7.3.1-These three tables are missing Missing tables with the PhiSS models were added 2, and 7.3.1-3 90. Figures 7.2.3-2 and These figures are missing. Missing figures were added 7.2.3-3 91. Figure 7.3.2-3, Page Please indicate in the cap1ion which panel is PGA and which is 1 s PSA Figures were modified to use consistent terms for the PGA 7-33 (the panel headers do this, but the information needs to be clearer, especially as the header uses T0.000 while the caption refers to PGA) 92. Figure 7.5-5 Please replace "/"with "and" so that the term "hiss/PhisP*R" will not be Text was revised as recommend confused as being a ratio. Also note that the figure is mislabeled (as 7 5-6) 93. Figure 7.5-7 To maintain consistency, please describe the three Italian datasets We are discussing three Italian models and not datasets. A referred to as .. Italy, PhiSS t -Italy, PhiSS2 -ltaly-PhiSS3" in the text. description of the Italian PhiSS models is included in Chapter 5. Section 5 5 We modified caption to say "models" instead than "data sets" CHAPTER 10 Tau Model Logic Tree for Both DCPP and PVNGS 94. General The chapter is tersely written. often with insufficient background The text was mildly expanded to make this chapter more self infonnation provided. and insufficiently thorough documentation of the contained and complete. logic tree and the assessment and evaluation that went into determining its branches and weights. Please ensure that the chapter is self-contained, with an adequate summary that references back to Chapter 7 (sigma overview chapter), and other chapters and appendices as needed. 95. Section 10.0 This paragraph has little substance. Please consider providing a done somewhat more complete outline of the chapter. 96. Section 10.1, Page Please point out the meaning of red versus green coding of the weights Figure caption is modified to explain the colors. This has 10-1, Paragraph 1. in Figure 10-1 (and in the caption of that figure) been explained in the text in the chapters on the median Line 2 logic tree so it is not needed again in the text of chap 10 97. Section 10.1, Page Please list or provide a reference to the parameter values of the scaled A reference to the new appendix P which addresses this 10-1, Paragraph t. Chi-square distribution that were used to compute the quantiles. Also, topic is added in the text. Mean value is the correct word Line 2 please confirm that it is the mean, not the 50th percentile, that was used for the central branch. 98. Section 10.2, Page Please consider replacing "observations" with "assessment" to indicate Text is revised as recommended 10-1, 1st Paragraph of that at this stage of the evaluation and integration that the Tl Team has Section, 2nd Line made its assessments of the proposed model. 99. Section 10.2, Page Please reference the appropriate sections of the chapter or appendix Initial hazard sensitivities are added to chapter 4. A cross 10-1, Item No. 1 where the hazard sensitivity analysis is presented that justifies the reference is added to the text in this section. specified magnitude and distances ranges of interest. 100. Section 10.2, Page Please also cite the published errata to Akkar et al. (2014) and Bindi et fixed 10-1, Item No. 2, 1st al. (2014) and include these errata in the list of references. Line 101. Section 10.2, Page The statement that The Zhao et al. (2006) magnitude-independent This statement is moved to later in the text where it fits into 10-1, Item No. 2, Last proponent model is judged to be applicable because their database is the modeling of the tau Sentence almost entirely composed of recordings from earthquakes with M 5" could be understood to be a counter argument to the adoption of a weight of 1.0 for the magnitude-dependent tau model mentioned in the beginning of this section. Please explain how the magnitude-independent tau model of Zhao et al. (2006) was incorporated into the magnitude-dependent tau model or remove this statement and discuss it later in the text 102. Section 10.2, Page Please either provide the full references to the acronyms BSSA 14, These acronyms have been defined in earlier chapters and 10-1, Item No. 3, 3rd CB14, CY14, and ASK14 the firsttime they are mentioned in Chapter 10 are also given in the list of acronyms and abbreviations. We and 4th Lines or ensure that they are defined the first lime they are mentioned in the do not see the need to define them in each chapter. report and that they are included in the list of acronyms. 103. Section 10.2, Page Please explain why it is proper to use the word "proponent" in this We deleted the word "proponent", because it is a model we 10-2, Paragraph t. sentence. derive. Proponent should be used for published models. We Line 4 will use the term "Tl-Team models for models developed by the Tl Team or under the direction of the Tl Team. 104. Section 10.3, Page Please avoid using the word "assuming" in this context, but rather We changed the word "assuming" to "using" 10-2, 1st Paragraph of replace it with a phrase that indicates that the logic-tree branches were Section, 1st Line developed by evaluating and assessing available data and results, referencing other sections of the report for supporting analysis if appropriate.

105. Section 10.3, Page Please provide a reference to sections/pages in Chapter 7 where the A reference to the new appendix P which addresses this 10-2, Sentence 2 evaluation of 0,2 is described. topic is added this the text 106. Section 10.3, Page Please either provide a reference that supports the specified A reference to the new Appendix P which addresses this 10-2, Sentence 2 approximation of a three-point discretization of a chi-square distribution, topic is added this the text including the specified weights, or explain the evaluation and basis for this approximation. 107. Section 10.3, Page In light of the discussions in Section 13.2, please clarify if the central, The logic trees for tau are not used directly in the hazard 10-2, general low, and high 1 branches described in this section are directly used in calculation. Rather, they are inputs to the simplified total comment on section the Hazard Input. lfnot, please explain the reasons for having this sigma models. The text is revised to make this clear. section. 108. Section 10.4, A large number of references contained in this section are not cited by fixed References this chapter. Please clean up the reference list 109. Figure 10-1. Page 10-Please add an explanation of the color scheme for the branch weights. Figure caption is modified to explain the colors. 4 110. Figure 10-2, Page 10-Please modify Figure 10-2 to show the final magnitude-dependent tau We believe it is valuable to see the underlying models and 5 model without all of the various models that were used to derive it and show that our range is broader than the range of the explain that this model is independent of frequency (the figure. being for proponent models, but this should be in Chap 7. We have T = 1 sec, implies that the model might be frequency-dependent). The swapped figure 7.2.5-5 (which just shows the final three other models shown in this figure were evaluated in a previous chapter models) with Figure 10-2. and need not be included in the final logic-tree model. CHAPTER 11 Phi Model Logic Tree: DCPP 111. Title Please add a subscript 'SS' to 'PHI' Text is revised as recommended 112. General The chapter is tersely written. often with insufficient background The text is expanded to make this chapter more self information provided. and insufficiently thorough documentation of the contained and complete. logic tree and the assessment and evaluation that went into determining its branches and weights. Please ensure that the chapter is self-contained, with an adequate summary that references back to Chapter 7 (sigma overview chapter), and other chapters and appendices as needed. 113. Section 11.1, Page Although the analysis of the aleatory variability is performed on the This is not the distribution of PHiSS. We are changing the 11-1, 2nd Paragraph within-event residuals, the distribution is on Phiss. Please remove form of the pdf of the residuals to allow for heavy tails. It is of Section, 5th "residual" to indicate that the distribution is for Phiss. not a change in the value of PhiSS. So it is not on the Sentence distribution of the phi SS but rather on the distribution of the residuals. See sketch below. /t;.) )hi SS -pdf x ows 114. Section 11.1, Page Please clarify if the phrase involving aleatory variability" is consistent The header in the figure was changed so to substitute 1 t-1, Paragraph 2. with the 'Epistemic Uncertainly' branch heading on Figure 11-1. "epistemic uncertainty" with "PhiSS estimate". Similar Line 6 changes were applied to figures 12-1 and 12-2 115. Section 11.2, Page Please provide references for the acronyms ASK 14. BSSA 14, CB 14. See response to comment 102 11-1, 1st Paragraph of and CY14 the first time they are mentioned in Chapter 11 or ensure that Section, 3rd Line they are defined the first time they are mentioned in the report and in nf 116. Section 11.3, Page Please further justify the assignment of equal (0.5) weight to the We have modified the CA models so that there are two M-11-2, Paragraph 1. magnitude-independent branch even though Figure M.4 suggests a clear dependent branches with break at M5.5 and M7. The text is Line 2 magnitude dependence in the California subset. Appendix references revised and additional justification is provided. should be specific, citing sections, pages, tables, and/or figures. 117. Section 11.3, Page Please provide a clear reference to where in Appendix M the absence of Appendix Mis incorporated into Chap 7. A cross reference 11-2, Paragraph 2. M-independence in the global dataset is illustrated. to the figure showing absence of mag dependence in the Line 1-2 global dataset (in chap 7) is added. 118. Section 11.4, Page This explanation is pretty cryptic until one studies Appendix M. Please The suggested change in wording is applied 11-2, Paragraph 2, consider whether clarity would be improved by an explicit statement that Sentences 1 and 2 the sampling distribution of (jlss at each site adds an upward bias on top of the true site-to-site variability of (jlss. Also consider whether the second sentence would be more precisely rendered if "removed 1he bias using" were replaced by "the bias was estimated assuming a chi-squared sampling distribution of (jlss 2 ",with reference to the place in the report where this assumption is justified. 119. Section 11.4, Page Coefficient of variation is abbreviated as CV here, but COV elsewhere. CV is used throughout the report. Changes have not been 11-2, Paragraph 2, Please make the notation consistent throughout the report. marked because occurred in several instances Sentences 3 and 4 120. Section 11.4, Page The assessment of the low and higher values of <Psss was not well A reference to the new Appendix P which addresses this 11-2, 2nd Paragraph documented in Appendix Mand in Chapter 7 (see previous comments). topic is added this the text of Section, Last Therefore, the statement that high and low epistemic uncertainty Sentence branches are computed corresponding to the 5th and 95th percentile of <Pss.s" does not have a well-documented basis at this point in the report. Also, the use of present tense infers that the calculations are discussed and included in Chapter 11 rather than in a previous chapter. Please revise Appendix M and Chapter 7 to fully support the assessment that the high and low values of <Pss.s can be represented as the 5th and 95th percentiles of the epistemic distribution. 121. Section 11.4, Page Please provide the mathematical basis for characterizing the central, 5th, Refer to the new Appendix P. We define the central estimate 11-2, 3rd Paragraph and 95th percentile values with weights of 0.6, 0.2, and 0.2, respectively. as the median. of Section Please also be more specific when referring to the "central" value as being the median. mean. or another statistical value of the distribution 122. Section 1.5, Page 11-Please provide a reference to the section (and pages, tables, and/or The directivity adjustment affects both the median and the 3, Paragraph 1, Line 2 figures, if appropriate) where directivity adjustment of <i'ss is discussed. aleatory terms. Both adjustments are described in Section 6.5 and shown in the figures herein We referenced back to that section. 123. Section 11.6, Page Please provide a brief description and reference of the "quantile plot (Q-A reference to a statistics text book is added to define Q-Q 11-3, 1st Paragraph of Q plot)" for clarity. plots, and we also added a short description of Q-0 plots Section, 3rd Line 124. Section 11.6, Page Please define what epsilon is the first time it is mentioned in Chapter 11, A definition of epsilon is added to the text 11-3, Paragraph 1. or ensure that it is defined the first time it is mentioned in the report and Line 4 that it is included in the list of terms. 125. Section 11.6, Page Because the concept of a mixture model is relatively new, all available We are now showing our own results 11-3, 2nd Paragraph sets of GMPE within-event residuals should be used to demonstrate that of Section, 1st the single mixture model proposed by the Tl Team can be used to Sentence characterize all of them. Please provide the analysis of residuals that was performed for ASK14 for the other three NGA-West2 GMPEs and demonstrate that the proposed normal distribution and mixture model is appropriate for all four GMPEs 126. Section 11.6, Page Please describe the "statistical tests" that were performed and provide a The statistical tests are test of the observed 0-Q plot being 11-3, 2nd Paragraph reference for these tests. above the 1-to-1 line for a given confidence level. Add of Section, 2nd Line explanation of confidence bounds in the figures. In addition. Anderson-Darling tests were applied and the reference is cited 127. Section 11.6, Page Please clarify who conducted the tests on KiK-net data. If it was outside The tests on Kik-net data were conducted under the Hanford 11-3, Paragraph 2, the SWUS project, please provide a reference. If it was within the SWUS PSHA project. However, now we are showing our own Line 6 project, please give more technical material so there is sufficient results and we do not need to reference Hanford anymore technical basis to support the conclusions derived from the KiK-net data. 128. Section 11.6, Page Please rewrite this paragraph to give a more rigorous presentation of The text is modified to expand the description of the mixture 11-3, Paragraph 3 mixture model, including appropriate references. The phrase "a sum of model. multiple normal distribution" could easily be misunderstood by those who are not familiar with the concept of mixture model 129. Section 11.6, Page Please describe the technical evaluations that lead to the selection of The sum of the two normal distributions was assessed using 11-3, Paragraph 3. mixture of two normal distributions with equal mean. a statistical package designed to identify mixtures in data. Line 3 The selected mixture was checked using Q-0 plots of the ASK 14 data and found to produce results consistent with distribution of the data. Text is expanded to explain this point 130. Section 11.6, Page Please describe the technical evaluations/calibrations that lead to the See response to comment 129 11-4, Paragraph 2. (0.5, 0.5) mixture weight and the (1.2, 0.8) scale factors, and that justify Line 4 the application of the model to all of relevant GMPEs (even though the model was calibrated using ASK14 residuals). Were parameters obtained by trial and error or by methods of statistical inference? 131. Section 11.6, Page Note also that the parenthetical epsilon range should be written with a Text was modified as recommended 11-4, Paragraph 2. minus sign, i.e."(<= -3)" Sentence 6 132. Section 11.6, Page The upper case phi in this equation appears to be the cumulative Correct, we defined the notation for the GDF 11-4, Equation 11-2 distribution function. Please check that the notation has been introduced and defined prior to its use at this point. 133. Section 11.6, Page Please explain what a composite normal distribution is. The word "composite" is deleted. 11-4, Paragraph 4, Line 1 134. Section 11.6, Page Please provide the technical justification for allowing a normal The mixture model is new and. while we strongly favor it, we 11-4, Paragraph 4. distribution with non-zero weight. given that you report that your analysis maintain the traditional normal distribution with small weight. Line 2 consistently showed heavy tails. 135. References

• General Please remove those references that are not cited in the text. References were removed comment 136. References, Page 11-Please update the Dawood et al. (2014) reference to include the volume Reference was corrected 5, Item 2 and page numbers of the published version, if available. 137. Figure 11-1, Page 11-Caption should explain the meaning of the color scheme used for the Figure caption is modified to explain the colors 6 weights 138. Figure 11-2, Page 11-Please explain what "Studentized Residual" is in the y-axis label, and Studentized residual is a normalized residual. This plot is 7 correct the caption by replacing "T=2 sec" with "T=0.5 sec" part of the build-in statistic package used in the analyses. We have now inserted more QQ figures 139. Figure 11-3, Page 11-Please replace "ASK" with "ASK14" in the caption Text was modified as recommended .!!

CHAPTER 12 Phi Model Logic Tree: PVNGS 140. General The chapter is tersely written. often with insufficient background The text was expanded to make this chapter more self information provided. and insufficiently thorough documentation of the contained and complete. logic tree and the assessment and evaluation that went into determining its branches and weights. Please ensure that the chapter is self-contained, with an adequate summary that references back to Chapter 7 (sigma overview chapter), and other chapters and appendices as needed. 141. Section 12, Page 12-Please replace "I" with "and" here and elsewhere in Chapter 12 to avoid Text was modified as recommended 1, 1st Paragraph, 1st confusion that the term "<pss I q>sr-R." refers to a ratio. Line 142. Page 12-1, Paragraph Please clarify whether the first motivation implies there is a significant No. this does not imply a significant dependence on mag, 1, Line 5 dependence on magnitude, distance, and style of faulting. dist, or SOF. Paragraph is rewritten to clarify the question. More figures provided in a NEW Appendix K 143. Section 12.1.1, Page Please remove "residual" to clarify that the aleatory distribution is for q>ss. The statement is correct. This is a distribution of residual and 12-1, 2nd Paragraph not the value of phiSS of Section, 4th Line 144. Section 12.1.1, Page Please consider moving this sentence to the beginning of this section. Done 12-1, Paragraph 2. Lines 4 to 6 145. Section 12.1.2, Page Please provide a reference to the section where the necessity to use The need for both data sets is discussed in Chapter 7. A 12-1, Paragraph t. both datasets is discussed. cross reference is added to the text Sentence 1. Line 1 146. Section 12.1.2, Page Please also reference the published erratum to Akkar et al. (2014 ), in fixed 12-1, 1st Paragraph of which case the reference becomes Akkar et al (2014a,b). Section, 2nd Line 147. Section 12.1.2, Page Please specify the magnitude and distance range. Also, please confirm The mag-dist range (M >=5, R <=50 km) is added to the text. 12-2, Paragraph 1. that the developers mentioned in this sentence are the NGA GMPE The "developers" are the NGA developers. The text is Lines 4 and 5 developers. modified to make this clear 148. Section 12.1.2, Page Please consider summarizing these data statistics in a table. Also, This text is repetitive and is moved in Chapter 7 which 12-2, Paragraph. 1 please clarify if these statistics are based on a data subset in which includes these tables. Lines 3to 9 each station recorded at least 3 earthquakes. 149. Section 12.1.2, Page Please provide a reference to the sensitivity analyses that show that Initial hazard sensitivities are added to chapter 4. A cross 12-2, 2nd Paragraph, large (M > 6) magnitudes are important for the hazard calculations at reference is added to the text in this section, (reference to 2nd Line PVNGS the deaggregation from previous studies) 150. Section 12.1.2, Page Only one limitation of the European dataset is listed as justification for Yes, all of the limitations were considered. 12-2, 3rd Paragraph the smaller weight given to the European dataset; whereas, several limitations are mentioned in the previous paragraph. Please clarify whether these other limitations contributed lo the Tl Team's assessment to give the European dataset less weight. 151. Section 12.1.4, Page Please justify the use of weights of 0.2, 0.6, and 0.2 to define the A reference to the new Appendix P which addresses this 12-2, 1st Paragraph of central, 5th, and 95th percentiles of the epistemic distribution of q>55. topic is added this the text Section, 2nd Please also be specific whether the central value represents the mean Sentence or median. 152. Section 12.2.1, Page The phrase "are added to" could be misleading (suggesting We removed the word "added" and slated that is used to 12-3, 2nd Paragraph mathematical addition of unspecified quantities), so please consider modify the GMPE of Section, 3rd Line using another wording. 153. Section 12.2.1, Page Please remove "residual" to clarify that the aleatory distribution is for See response to comment 143 12-3, 3rd Paragraph IPss. of Section, 4th Line 154. Section 12.2.2, Page Please summarize why a single dataset is appropriate for each branch We only have one set of Arizona data for the path term 12-3, 1st Paragraph of of the logic tree. branch. For the no-path term branch, the California model is Section, 4th Line not used because the site is not in California and the global model is judged to be more appropriate. This discussion and basis is added in the text. 155. Section 12.2.3, Page Please provide a reference to specific sections, pages, tables, and/or Appendix N is incorporated in the main report. Cross 12-4, 1st Paragraph of figures to Appendix N. references is provided Section, 1st Line 156. Section 12.2.4, Page Please provide the basis for the increased CV (i.e., COV) from 0.14 to The difference occurs because the CV for the Arizona data 12-4, Paragraph 1. 0. 17 (and please ensure that terminology for coefficient of variation is set is higher. The terminology is made consistent to use CV. Line 2 consistent throughout the report and appendices). 157. Section 12.2.4, Page Please justify using weights of 0.2, 0.6, and 0.2 to represent the 5th, A reference to the new Appendix P which addresses this 12-4, 1st Paragraph of central, and 95th percentiles of the epistemic distribution of the Phi topic is added this the text Section, Last terms. Please also be specific whether the central value represents the Sentence mean or median. 158. Section 12.2.5, Page Please clarify who made the judgment and describe the basis for the This is a Tl Team judgment and text was modified to make 12-4, Paragraph 1. judgment. this clear Line 3: 159. Section 12.2.5, Page Please provide the technical justification for allowing a normal see response to comment 134 12-4, Paragraph 1. distribution with non-zero weight. given that your analysis consistently Line 4 showed heavy tails. 160. Section 12.3, Page Please revise the date to "2014a" to reflect the published manuscript and fixed 12-4, 1st Item the fact that the erratum was published in the same year. 161. Section 12.3, Page Please update Akkar et al. (2014) to Akkar et al. (2014b) and provide the fixed 12-4, Item 2 volume and page numbers of the published erratum. 162. Section 12.3, Page Please remove the Abrahamson et al. (2014) reference or cite ii in the fixed 12-4, Item 3 text. 163. Figure 12-2 Figure is incorrectly numbered ("Figure 1") Figure label for fig 12-2 was corrected CHAPTER 13 Total Sigma Model 164. The chapter is tersely written, often with insufficient background The text is expanded to make this chapter more self information provided, and insufficiently thorough documentation of the contained and complete. logic tree and the assessment and evaluation that went into determining its branches and weights. Please ensure that the chapter is self-contained, with an adequate summary that references back to Chapter 7 (sigma overview chapter), and other chapters and appendices as needed. 165. Section 13.1 Please provide an overview of the methodology used in other recent An overview is added to the text SSHAC Level 3 PSHA studies to construct total sigma models. 166. Section 13. 1 This methodology can significantly benefit from an extensive rewrite Sections is rewritten to better explain how the total sigma (including related parts in Chapters 7, 10, 11, and 12) to improve model is a more efficient version of the combination of the readability and understandability. Please provide a clear and easy-to-separate phi and tau models understand presentation of the basic principles and ideas behind the methodology, which should also serve to connect the various pieces presented across Chapters 7. 10, 11, 12, and 13. 167. Section 13.1, Page Please verify and, if found incorrect, provide the proper references The text is modified to refer to the logic tree branches in 13-1, Paragraph 1. where logic-tree branches are presented. Chap 10, 11, and 12. Line 1 168. Section 13.1, Page Please check whether this report section actually applies the Miller and The new Appendix P addresses this topic. We are using the 13-1, Paragraph 1. Rice (1983) methodology. Otherwise the reference to that paper here is 5th. 50th, and 95th fractiles as the three point distribution. Line 2 misleading and should be dropped. Consider whether Keefer and Bodily Also, the Miller and Rice reference was not correct and was is an appropriate reference for the type of distribution resampling applied removed here. 169. Section 13.1, Page The reference to the book by Ang and Tang (2007) is too general. The new Appendix P addresses this topic. The specific 13-1, Paragraph 1. Please confirm that this reference is the appropriate one for the discrete sections of Ang and Tang (2007) is cited in the appendix Line 3 representation of scaled Chi-squared distributions, and if so, please cite page number(s). 170. Section 13.2, Page Theo here appears to be the same as Oss in Eq 5.4.1-1 on page 6-20 The text is modified to indicate the fact that the type of total 13-1, Paragraph 1. (October 2014 draft), and in Section 13.4, second to last line on page sigma depends on the type of phi Lines 5-6 and Eq. 13-13-3. If that is correct, please replace cr with crss throughout the chapter 1 for consistency with terminology used elsewhere in the report. 171. Section 13.2, Page Please discuss or reference the "resul1s" being referred to in the The results are from the NGA-West2 regression studies. but 13-1, 1st Paragraph of statement "results that show a very weak negative correlation between ' these were not published. We will add the correlations from Section, 10th Line and cp". the ASK14 and CY14 studies to show the size of the correlation. 172. Section 13.2, Page Section 7.3.1 does not provide the definitions of the scaled chi-squared A reference to the new appendix P which addresses this 13-2, Paragraph 1. distribution as claimed. Please provide a correct reference. topic is added this the text Line 1: 173. Section 13.2, Page The first equality is nawed: no non-constan1 function of xis equal to the The equation is correct. As sigma is always non negative. 13-2, Paragraph 1. same function of x2. This abuse of notation is confusing. If it is necessary there is a monotonic one-to-one relationship between o and Equation 13-3 to introduce the first equality, please clarify its meaning. o2. As a result the probability that a is less than or equal to x is equal to the probability that a2 is less than or equal to x2 for all non negative x 174. Section 13.2, Page In equation 13-4, c is defined as a function of sigma-squared, treated as This is described in the new appendix P 13-2, Paragraph 1. a deterministic variable, but sigma is a random variable in Equation 13-3. Equations 13-4, 13-5. The same applies to the definition of constant k in Equation 13-5. The substitution of Equations 13-4 and 13-5 into 13-3 leads to incomprehensible results. Please define and use notation that clearly distinguishes between the random variable and the deterministic variable 1hat represents a distribution model parameter. This should be done in a manner that maintains consistency with the rest of the report notation. 175. Section 13.2, Page Please indicate what typical numerical values of c and k are. This is described in the new appendix P 13-2, Paragraph 1. following Eqn 13-5 176. Section 13.2, Page Please provide an explanation of what a "weighted composite CDF" is The term "weighted composite CDF" refers to the 13-2, Paragraph 2, and how it was computed. Also, please confirm that the composite CDF combination of the phi and tau (composite) using the weights Lines 5-6 is for (j)ss only (as indicated in the legend of Figure 13-4). Finally. please from the phi and tau logic trees. Fig 13-4 is for the total, not explain why composite CDF for <Pss is created and presented in this only for PhiSS. The legend shows the PhiSS part with the chapter, not in Chapters t 1. 12. Also note that the sentence beginning same tau models added in each case. Text revised and on line 5 ("Using weights ... ) is garbled-please revise to clarify its augmented to provide additional details explaining how the meaning. models were derived. Garbled sentence rewritten. 177. Section 13.2, Page Please add text to explain how the weigh1ed composi1e CDF for 4>ss was See response to comment 176 13-2, Paragraph 2, used to form the composite distribution of total sigma given in Table 13-Line 5-7 1. 178. Section 13.2, Page Please provide a reference for the statement made in this sentence. If it A Table has been added to support the statement. More 13-2, Paragraph 2, is based on SWUS's own investigation, then please include, at a verbiage provided Sentence 6 minimum, a supporting figure for this conclusion. 179. Section 13.2, Page Please confirm that variance, not standard error, was the quantity that The fractiles are developed on variance; we simply take the 13-2, Paragraph 1. was used in the analysis throughout this report. Also. please explain square root of the sample point for the standard deviation Last Line (Eq. 13-6) how you go from a model of variance to a model (Eq. 13-6) of standard The fractiles are not affected by the square root operation. deviation. Text was modified to explain this. 180. Section 13.2, Page Also please reference where in the report the basis for Equation 13-6 In the text. we will note that a bilinear model was used based 13-2, Paragraph 1. can be found. on the bilinear model for PhiSS. Last Line (Eq. 13-6) 181. Section 13.3, Page Please briefly summarize the three uncertainty models being referred to The three models are the PHISS models for greater AZ 13-2, 1st Paragraph of in this sentence. and clarify that the models for PVNGS are (or <Pss-r) sources, the PHISS for the CNMEX sources, ad the PHISP-Section models (as opposed R for the CNMEX sources. The text is revised to make this clear 182. Section 13.3.1, Page Please add text to discuss the need for two alternative models. The need for the two alternative models is that there are two 13-3, Paragraph 1. branches in the logic tree for data sets in Chapter 12. We will Line 2 revise the text to reference back to Chapter 12. The total sigma model is just a parameterization of the tau and phi models from Chapters 10 and 12. 183. Section 13.3.1, Page In addition to Table 13-2, please also provide a figure similar to Figure The requested figure is added. 13-3, 1st Paragraph of 13.4 to show how well the composite distribution fits the original Section, Last distribution. Sentence 184. Section 13.3.2, Page In addition to Tables 13-3 and 13-4, please also provide a figure similar The figures are not needed because there is only one phi 13-3, 1st Paragraph of to Figure 13.4 to show how well the com po site distribution fits the model being used Section, Last original distribution. Sentence 185. Section 13.4, Page Please provide a reference (such as Jayaram and Baker, 2010) for the We added "They found that" at the beginning of the second 13-3, 1st Paragraph of statement "it leads to an increase in the .p estimates and decrease in the sentence. Section, 3rd Line t estimates". or provide another basis for this statement. 186. Section 13.4, Page According to Appendix R, the analysis was done on the model of CY14 The text is modified to make this consistent with the current 13-3, 1st Paragraph of (Chiou and Youngs, 2014). Please remove "preliminary" and revise the Attachment D Section, 5th Line date from "2013" to "2014" in the statement "preliminary CY14 (Chiou and Youngs, 2013)" to conform to the discussion in Appendix R. 187. Section 13.4, Page Please change the reference to Shahi (2014), here and at other The work by Shahi and Colleagues is packaged as a "Report 13-3, Paragraph 1. locations. to reflect the multiple authors of Appendix R. Also, please use to GeoPentech for the SWUS GMC Study", and properly Line 5 some alternative style for the citation, as the author/year form of citation referenced in the Reference. It is documented in the report is only appropriate for an article or report that appears in the reference as an Attachment (thus not as an Appendix anymore) list, not for an internal reference to an appendix, which is an integral part of the report. 188. Section 13.4, Page Please clarify what the terms "homoscedastic" and "heteroscedastic" Homoscedastic refers to the magnitude-independent model 13-3, 1st Paragraph of refer to in this context. and heteroscedastic refers to the magnitude-dependent Section, 6th and 7th models. Clarifying text is added. Lines 189. Section 13.4, Page Please clarify who conducted the semivariogram analysis (was it the Tl This analysis was done by Linda under the direction of the Tl 13-3, Paragraph 1. Team or Shahi et al., Appendix R). and provide a reference that Team. Proper reference is provided. Line 9 describes the semivariogram analysis methodogy. 190. Section 13.4, Page Please explain what normalization factor was used for the normalized The variogram is normalized by the variance of selected 13-3, Paragraph 1. variogram. Please also change the figure caption and the y-axis label of subset of the data. This is explained in the text Line 12 Figure 13-6 to reflect the use of normalized variogram. 191. Section 13.4, Page Please specify the amount of reduction in tau that was used to obtain the The reduction in tau is ranges from 0 to 7% (see Figure 13-5. 13-3, Paragraph 1. 4% increase in total sigma. This is added to the text. Thi rd to Last Line 192. Section 13.4, Page Please justify why it is appropriate to change the weights for all spectral The results from 2010 and 2014 show very different period 13-4, 1st Paragraph, periods when the analyses of Jayaram and Baker (2010) and Appendix dependence. This is a small effect and we choose to model it 3rd Sentence R indicate that they are period-dependent. Please also explain how what as a constant to all periods. The average of the 2010 and appears to be a relatively large degree of epistemic uncertainly 2014 models is close lo be period-independent. Clarifying depending on the dataset that is used to perform the analyses is taken text is added. into account. when results are available for only two datasets. 193. Section 13.4, Page Please discuss whether the modified weights (which constitute a skewed No. we are not capturing the true shape but this is a 13-4, Paragraph 1. discrete distribution) adequately capture the true shape of the sigma relatively new work with inconsistent results between 2010 Last Sentence distribution that accounts for spatial correlation in residuals. Please also and 2014. So we are using a simpler approach by discuss if the 3-4% increase in mean sigma is justified and if the introducing skewed weights on the branches from the variance of total sigma is unaffected by the consideration of spatial standard approach (i.e. ignoring the spatial correlation correlation in residuals. effect). We think this a reasonable approach at this state of development of the analysis. Text is modified lo explain this justification. 194. Section 13.5, Page In previous discussions of these distributions, they were described as Inconsistent terminology is cleaned up 13-4, 1st Paragraph of normal and a mixture of normal without "log" in front of them. It was Section, 1st Sentence relatively clear that this was because the distributions were developed from the within-event residuals, which have natural log units. The use of "log" now can be confusing given these previous discussions. Please explain why "log" is now being used to describe these normal distributions for additional clarity or remove "log" and describe that the distribution is on a parameter that has units of natural log. 195. Section 13.5, Page Since not cl>. was used in Eq 13-1, please justify the decision to apply Justification is provided 13-4, Paragraph 1. the same factors and weights for .p lo .Pss. Line 4 196. Section 13.5, Page Please replace "event-to-event" with "between-event" to be consistent The term is changed, and consistent terminology is used. 13-4, 1st Paragraph of with terminology used elsewhere in lhe report. Section, 6th Line 197. Section 13.5, Page Since <Pss. was used in Eq. 13-1, please rewrite this sentence in The term is changed, and consistent terminology is used. 13-4, Last Sentence terms of 198. Section 13.6, Page Please update the Abrahamson et al. (2014) reference to include the fixed 13-4, Item 1 page numbers of the published manuscript. 199. Section 13.6, Page Please provide the location of publisherfor the Ang and Tang (2007) fixed 13-4, Item 2 reference. 200. Section 13.6, Page The date is incorrect. This report is actually Chiou and Youngs, 2013. fixed 13-4, fourth entry But please remove it from references, since the citation in Appendix R is actually of the published paper, Chiou and Youngs (2014) 201. Section 13.6, Page Please update the Chiou and Youngs (2014) reference lo include the Reference was updated 13-5, Item 1 page numbers of the published manuscript. 202. Section 13.6, Page As noted in an earlier comment, it is questionable whether this article Reference was checked and text was updated as applicable 13-5, Last item was correctly cited. If the citation is deleted, please also delete this reference section entry and replace with the correct reference. 203. Table 13-4, Page 13-Sigma listed in other tables show an increasing trend with period. Please The observation is correct. For the large distance data set 9 provide explanation for the decreasing trend shown in this table. Also, at (200-400 km). the standard deviation decreases with period. T>= 5 sec, the central branch in Table 13-3 is higher than the central The other comparisons were for shorter distances. There are branch in Table 13-4. Please clarify whether <lisP-R is supposed to be no inconsistencies between these two sets of results. On always lower than <liss for all periods (because of the removal of average, PhiSP-R is lower than PhiSS for large numbers of systematic path effect) and whether the above-mentioned reversal is data set However, for an individual path. PhiSP-R may be expected. larger ifthe crustal structure is more variable than average. This was explained in the text. 204. Figure 13-6, Page 13-Please note that the legends are erroneous in both the upper and lower Legend is corrected 6 panels: the exponential functions are incorrectly identified with the blue asterisk symbols instead of with the red curves. 205. Figure 13-7. Page 13-The caption refers lo preliminary CY14 model and cites Chiou and See response to comment 200 14 Youngs (2013). But Appendix R says that the Shahi et al. analysis is for the published work, not the preliminary model, and cites the published paper Chiou and Youngs (2014). Please correct. and use an appropriate reference to Appendix R rather than the author/date citation of Shahi APPENDIX L Path Terms for PVNG and Associated Phi _sp-r Model 206. Section L.1, Page L-1, 1st Please explain why path-specific effects are used and why they are Appendix is absorbed into the report (Chapter 7). Text is Paragraph, 1st Sentence appropriate for modeling the ground motion from California and Mexico added to Chapter 7. See also response to comment 1 t earthquakes. It would also be helpful to clarify in this introductory paragraph that .PsP-R is an alternative model to <liss for representing site-specific within-event standard deviation (that they are mutually exclusive alternative models for PVNGS). 207. Section L.1, Page L-1, Line The notation <lisP-R is used here without introduction. Please ensure that Because Appendix N is absorbed into Chapter 7, the term is 3 notation is defined at the time it is introduced. introduced the first time it is used in the chapter 208. Section L.2, Page L-1, 1st Please reference the specific dataset(s) from Chapter 5, and explain why Specific data set is referenced. The deaggregation shows paragraph of section only four spectral periods are available and why these four periods are that the contribution to the hazard from the sources is only at sufficient to conduct the analysis of path terms. long periods, so we are focusing on the long periods. 209. Section L.2, Page L-1, 1st Please provide full references or previously defined acronyms for the 4 Because Appendix N is absorbed into Chapter 7, the Paragraph of Section, 3rd NGA-West2 GMPES" the first time they are mentioned in the appendix. references are properly provided Line 210. Section L.2, Page L-1, First Please clarify whether every AZ station recorded the same set of CA The current equations were meant to be easy to understand Paragraph, Line 7 events. If not. please add text to comment how this situation is addressed but they do not capture the unequal sampling. We in Equations (L-3) through (L-8). reformatted the equations to show the unequal sampling (even if leading to more complex notation ..... ). Appropriate notation is introduced with the modified formulas. 211. Section L.2, Page L-1, 2nd Consider saying "for sources in regions" instead of "for regions", to avoid Verbiage is changed as suggested Paragraph of Section, first any misinterpretation that within-region paths are being characterized line rather than region-to-PVNGS paths. 212. Section L.2, Page L-1, 2nd Please give specific reference to the chapter, section, and figure Proper cross-reference to Section 4.2 is provided Paragraph of Section, first number(s) where the three regions are defined line 213. Section L.2, Page L-1, Please justify Eq. (L-2) as representing the average path term. This is a mean residual for a given path. Formulas are Second Paragraph, Line 4 reformatted to make it easier to understand. 214. Section L.2, Page L-1, Please define Nc;MPE* See response to comment 210 Equation L-2 215. Section L.2, Page L-1, 2nd Please replace "eq(x)" with the correct equation reference. Proper Equation reference is provided Paragraph of Section, 6th Line 216. Section L.2, Page L-1, 2nd This sentence is redundant (as the same info1111ation is conveyed by the Sentence is removed Paragraph of Section, 7th parenthetical remark two sentences earlier). If retained, please change Line "NGA-W-2" to a consistent abbreviation used throughout report. 217. Section L.2, Page L-2, Please define NSTA;. and NEQK *. See response lo comment 210 Equation L-3 218. Section L.2, Page L-2, 1st Please explain the need to preserve the range of the medians obtained Our goal is to capture the range for large magnitudes sentence after Eqn L-4 from the 4 GMPEs, and be specific about the medians being referred to. whereas the available data are for small M: accordingly, we Note also that this and the following sentence mix references to "median want to retain the range of M scaling from the GMPEs -and "mean". If this distinction is intended, please clarify; otherwise, please Clarifying text was added. The distinction between use te1111inology that consistently treats either amplitudes or log median and mean terminology is intended Median refers to amplitudes as the principal variate. PSA (arithmetic units), whereas mean refers to the log of the path term. Clarifying text was added 219. Section L.2, Page L-2, 2"c Please be specific about the "residuals" referred to in this sentence. See answer for comment 218 sentence after Eqn L-4 220. Section L.2, Page L-2, 2nd Please justify why a minimum of 5 recordings for each station is adequate The reason for requiring 5 recordings is that these estimates Paragraph on page, 1st in this analysis and explain why this number is larger than the minimum of are used to correct to GMPEs, whereas the other were used Line 3 recordings used in other analyses conducted for the project. Please also to adjust the distribution. Fewer recordings are needed to explain if those earthquakes with less than 5 recordings were discarded or estimate the standard deviation of the distribution of used in other parts of the analysis. residuals than are needed to estimate the median path effect. The selection of number of recordings is a pragmatic selection based on the number of available recordings. If we choose too large of the number, we would not have sufficient data to work with. The limitations of the selected number of recordings are discussed in the text. Additional comments are provided in Chapter 5 221. Section L.2, Pages L-2, Please discuss the possibility of mapping the path te1111 into the site term The site terms are used to correct to CA GMPES to AZ on Second Paragraph on and the consequences of such miss-mapping, if significant. average, whereas the path terms are used to distinguish page, Line 3 between path effect for regions 1 and 2&3. The net effect is the sum of the two terms. Path effect that applies to both regions could be mapped in site term but it does not matter. Clarifying text is added to the report 222. Section L.2, Page L-3, 1st Please consider using a font for the "lower-case L" subscript that is less Text is changed as suggested Paragraph on page, 1*1 line apt to be mistaken for a "one", and please write "region 1" with a font that after Eqn L-8 is less apt to be mistaken for "lower-case L". 223. Section L.2, Page L-3, 1st For completeness, please provide the equation for the standard error of Equation is added Paragraph, first 2 lines afte1 he mean path terms. Eqn L-9 224. Section L.2, Page L-3, 2nd Please explain why the value for T = 0.2 sec was not used in deriving the See response to comment 7 4 Paragraph on page, seconc central path te1111 when Figure L.5 shows that it is similar to the other line after Eqn L-10 periods, and also why the average of the few available periods is an appropriate representation for all periods. 225. Section L.2, Page L-3, 2nd Please consider removing the discussion of logic-tree branches and Discussions on weights is moved to the appropriate chapter Paragraph, 3rd Sentence weights and reserve this discussion instead for the report section on the appropriate logic-tree models. It would seem appropriate to discuss the high and low uncertainty bounds, but the evaluation of the central, low. and high values should be presented in the discussion of the logic-tree models. 226. Section L.2, Page L-3, 2nd Please explain why T = 0.2 sec was not used for the shorter periods and See response to comment 74 for T = 0.2 sec. The Paragraph, 4th Sentence why T = 2 sec was not used for the mid-periods, given that additional uncertainty is based on the number of recordings at each uncertainty was added for periods greater than 2 sec. It appears that the period, not on the difference in average values between two entire uncertainty model is based primarily on only two spectral periods. periods. Accordingly, this is not just two data points. The T = Please explain the justification and basis for the path terms, given that 2 sec period is modeled separately because additional essentially only two spectral periods are used in the assessment. epistemic uncertainty is added to T > 2 sec. Clarifying text is added to describe this. 227. Section L.2, Page L-3. Please provide rationale for the need for additional epistemic uncertainty The range from the 5 NGA GMPEs captures the epistemic Second Paragraph, 2"" to T > 2 sec, and for the approach by which that additional epistemic uncertainty below 2 seconds. but additional epistemic last sentence of section uncertainty is determined. Also, please explain why it is not needed for T uncertainty is needed at period > 2 seconds. Clarifying text is < 2 sec. added. 228. Section L.2, Page L-3. Please clarify if the uncertainty in the path term due to the small sample Because the data are from small magnitudes. we maintain general size and small magnitude range (all but 2 data point are from M<5.2 the range of the medians from the 5 NGA GMPEs to capture events) of AZ. data needs to be incorporated. the uncertainty in the large magnitude scaling. Additional text is provided. 229. Section L.3, Page L-4, 1st Please reference Figure L.8 for the statement "The 4>sr*R. (T) at a period of Figure is now properly referenced Paragraph, last Sentence 0.2 sec was not used in deriving the central model due to the large variability in the values obtained for the 4 GMPEs at this period and because sources in regions 1 , 2. and 3 do not contribute significantly to he hazard at short periods". 230. Section L.3, Page L-4. 1st Please explain why the mean estimate, including the 0.2 sec value. is not The 0.2 sec value is not relevant to the hazard and was Paragraph, last Sentence appropriate to use (even though the variability might be larger). If indeed removed from the plots to avoid any confusion. In general. he hazard is not impacted at T = 0.2 period from the California/Mexico below 0.5 sec is not relevant to the hazard, so a constant earthquakes, then that should be sufficient to ignore it. but then that value is acceptable as it does not matter. The long period leaves only three periods (all defining a slope) to describe what happens extrapolation of PhiSP-R was re-evaluated, and found that at T < 0.5 sec and T > 2 sec. Please explain the justification for assuming there are not enough data points to constraint the estimate a constant value of beyond the limits of the observations. when all above 2 sec hree of the observations defines a frequency-dependent slope. 231. Section L.3, Page L-4, 1st Please cite the specific section and figure( s) of the report where it is Proper reference is provided. pointing at Chapter 4 (planned Paragraph, last Sentence demonstrated that hazard at 0.2 sec is not impacted by sources in regions addition therein of the deaggregation from previous PSHA 1, 2, and 3. studies) 232. Section L.3, Page L-4, 2nd Please justify why a scaled chi-square distribution is appropriate and New Appendix P will address with point. Proper reference is Paragraph, 1st Sentence provide a reference for this distribution and the related equations (or provided. reference a section of the report where the issue is treated). Although the discussion of low and high values is appropriate, please consider removing any discussion of logic-tree branches and reserve this assessment for the discussion of the logic-tree models. 233. Section L.3, Page L-4, 2nd Please expand the discussion of the GOV with equations or additional text Clarifying text is provided, and CV instead than COV is used Paragraph, 2nd and 3rd (and rewrite for better clarity) to show how the COV of 0.17 was throughout the report Sentences estimated. Also please ensure that a consistent notation for coefficient of variation is used throughout the report. 234. Section L.4, Page L-4 Please provide missing references. not needed because Appendix is absorbed in main report APPENDIX M Phi SS Models for DCPP - 235. General Section 11.3 refers to Appendix M for the Tl Team's technical basis of Appendix is absorbed into main report, and technical bases giving 0 weight lo the magnitude-dependent branch. However. such are incorporated in the main report, as applicable. basis is not yet provided in this Appendix. Please add details of the technical evaluations that support 1he selection of 0 branch weight for the magnitude-dependent-cl>ss branch. 236. Section M.1. Page M-Please confirm that the acronyms ASK14, BSSA14, CB14, and CY14 See response to comment 102 1, 1st Paragraph, 2nd are defined by their full citations the first time they are used and verify Line that they are included in the list of acronyms. 237. Section M.1. Pate M-"CA" should be spelled out as "California", and should be accompanied Text is modified as suggested, and proper reference to the 1, 1 *1 paragraph. line 3 by the name of a specific dataset that has already been defined and data set is provided. listed in a table of data sets elsewhere in the report (and that table should be referenced here). The specific dataset name should be used consistently throughout the report. 238. Section M.1. Page M-Please explain why non-NGA data from regions other than Taiwan (such The Japanese residuals were not available to us at the time 1, First Paragraph, as the Japanese data set used in the PAGASUS project) are not of this project. Rather than using the Japanese data, we Line 3 considered in this project. compared the SWUS PhiSS model to the PEGASOS model. 239. Section M.1. Page M-Please indicate whether the terms "site terms and single-station within-Appendix is absorbed into main report, and terminology is 1, 1st Paragraph, 5th event residuals" have been defined in the main report prior to being included in the main report, as applicable. Line mentioned in Appendix M. If not, these terms require a specific reference to a section in the report or another appendix for their definition or they should be defined when first used in Appendix M. 240. Section M.1. Page M-Please indicate how the site terms and single-station within-event See response to comment 70 1, 2nd Paragraph, 1st residuals were calculated from the entire database for CB t4. which only and 2nd Lines fit an average anelastic attenuation term with data from distances of 80-500 km (i.e., the more distant data was not used to develop all of 1he parameters in the GMPE and, therefore, do not necessarily have unbiased between-event or within-event residuals beyond 80 km). 241. Section M. t, Page M-Please provide the justification and basis for the specific magnitude and Reference to deaggregation from previous results shown in 1, 3rd Paragragh, 1st distance ranges that were selected. Chapter 4 is provided. Sentence 242. Section M 1. Page M-Please describe the specific ,Pss terms that are referred to in this Terms are described. See reply to Comment 64 1, 3rd Paragraph, Last sentence, and explain why this sentence does not contradict the Sentence statement made in Section 11.3 (Page 11-2, Second Paragraph) that "For the global data set, a magnitude-dependence in the cl>ss is not seen" 243. Section M. t. Page M-Does this wording mean that the Lin et al dataset has been The data labeled "Taiwan refers lo both NGA-West2 and Lin 1, 4'" paragraph, 1*1 superimposed on each of the NGA-West2 datasets? Are the red circles et al (2011). Text to clarify this point has been added to sentence to denote "Taiwan" representing part of the NGA-West2 datasets, or are Chapter 5 these from Lin et al., or both? Please clarify. 244. Section M 1. page M-Please replace the lower right plot with the data distribution plot for Plot now shows the CY14 data distribution instead than the 1, paragraph, and CY14. Also, please check all the plots for accuracy; it seems odd, for duplicate of BSSA 14 data distribution. In chapter 5 Page M-5, Figure M.1 example, that the CB 14 plot shows only a handful of Italy data and no Japan data at all. 245. Section M2. Page M-This sentence seems to have a missing word. Please rewrite to make its Sentence is rewritten 2, 1"' sentence meaning clear. 246. Section M.2. Page M-Please provide plots similar to those in Figure M.4 for a wider range of Additional plots are provided 2, 1st Paragraph, 3rd spectral periods to more thoroughly document the magnitude-dependent Sentence cl>ss model. 247. Section M.2. Page M-Please consider changing the word "variances" to for clarity. Text was modified as suggested 2, 1st Paragraph, end of 3rd Sentence 248. Section M 2. Page M-2, 1"' Paragraph. Please consider a rewrite of this sentence for accuracy and clarity. Sentence was rewritten Lines 4 and 5 249. Section M 2. Page M-Please describe how the estimated was smoothed over periods A description of the smoothing algorithm is provided 2, First Paragraph, given estimates at only 5 periods. Lines 6 and 7, Figure M.3 250. Section M.2. Page M-Please provide a justification and basis for using only a magnitude-The distance dependence seen in the Rodriguez-Marek 2, 2nd Paragraph, 1st dependent <l>ss model and not a model that is dependent on both model only applied to smaller magnitudes, and disappears at Line magnitude and distance. M > 5. Therefore we have not developed a distance dependent PhiSS model. Clarifying text is provided 251. Section M2. Page M-Please correct "M.4" to "M.5. Figure number was corrected 2, 2nd Paragraph, Line 5 252. Section M.2. Page M-Please also reference Table M.2 for the a and b coefficients in Equation done 2, 2nd Paragraph, ( M-1) and explain how the "high" and "low" values in Table M.2 were Last Sentence determined. Although Table M.2 is referenced in the next section. because the a and b coefficients are presented here, their tabulated values should be referenced. 253. Section M.3. Page M-Please carefully review this sentence for accuracy and reword for clari1y. done 3, First Paragraph. Lines 1and2 Dr. Carola Di Section M.3. Page M-Please provide the technical basis for selecting 0.12 as being See new Appendix P for the CV value. We had also Alessandro 3, Second Paragraph. representative. Please also clarify whether hazard is sensitive to the performed sensitivities to CV which are describes now in Line 4 COV value and if there is significant uncertainty in selecting the value. Chapter 7. 255. Section M.3. Page M-Please add text to discuss the evidence and implica1ion of the The M-dependence of the CV has not been evalua1ed. Text 3, Second Paragraph. magnitude-independence of COV, particularly for evaluating the was revised to include this discussion. Line 4 epistemic uncertainty in the magnitude-dependent ,Pss 256. Section M.3. Page M-Please provide justification for the use of a chi-square distribution and See new Appendix P 3, 2nd Paragraph, provide a reference to this distribution and the related equations. Last Sentence 257. Section M.3. Page M-Please add text to provide a source of or derivation for the relationship See new Appendix P 3, Second Paragraph, = 2

• last sentence 258. Section M.4. Page M-Please provide the missing references. Appendix is absorbed into main report, and references are 3, References incorporated in the main report, as applicable. 259. Table M. 1. Page M-4 Please provide another table that lists the number of earthquakes and Table is provided, and text was revised to clarify that the recordings for the M5.5 and greater database. Please also indicate that statistics are for sites with at least 3 recordings. these statistics are for sites with at least 3 recordings. 260. Figure M.2, Page M-6 Please explain why not all of the common spectral periods included in This subset of periods was considered to be representative the NGA-West2 GMPEs are included in Figure M.2. of the period dependence. Clarifying text is provided 261. Figure M.3, Page M-7 Please explain why the values for the models and their averages are The averages are for the global data. For the Lin et al (2011) shown for only five spectral periods in Figure M.3. data set we only have five periods. Text is added to clarify this point.

262. Figure M.5, Page M-8 Please explain why only a subset of the available spectral periods for the The values are not stable at 10 seconds as shown in Figure NGA-West2 GMPEs are used and why there is no value at 10 sec M.2. This value at 10 seconds is not used for the smoothing. period; whereas, this period is shown in other figures. Clarifying text has been added 263. Figure M.8, Page M-Please explain why not all of the common spectral periods included in See reply to comment 260 11 the NGA-West2 GMPEs are included in Figure M.8. 264. Figure M.9, Page M-Please explain why the values for the models and their averages are Those are the periods for which the Lin et al (2011) data 12 shown for only five spectral periods in Figure M.9. was available. Clarifying text is added 265. Figure M.10, Page M-Please explain why not all of the common spectral periods included in See reply to comment 260 13 the NGA-West2 GMPEs are included in Figure M.13. 266. Figure M.10, page M-Because there are two global datasets employed in Chapter 11 and New notation is being used to clearly identify each data set, 13 Appendix M, the caption, if it alludes to "the global dataset," the text including the two versions of the global data set should make it clear that the "global dataset" referenced here is the one specifically used to derive the epistemic uncertainty in 4>ss (which is distinct from the other global dataset specifically used lo derive the central 4>ss model, for which the magnitude-dependent branch does not exist). APPENDIX N Phi _ss Models for PVNGS 267. Section N. 1, general It is potentially confusing that 4>ss and 4>sP-R are discussed in separate Appendix N is absorbed into the main report. comment appendices (N and L. respectively), even though they seem to be mutually exclusive alternative branches of the same logic-tree node. Please provide some connective discussion to clarify this relationship. 268. Section N.1. Page N-Please reconsider the use of the term "proponent" in this context. as it See answer to General comment 8 1, 1st Paragraph of may cause confusion as to whether the proponent is an outside expert or Section, 1st Line is the Tl Team. 269. Section N.2. Page N-Please quantify what is meant by "important" and provide a specific The term "important" was replaced by the quantitative 1, 1"' paragraph, line 2 (section, figure number) reference to the part of 1he report where 1hese estima1e of the fractional contribution to the hazard. Text was deaggregation results are documented. Also note the misplaced word revised accordingly. "consideration". 270. Section N.2, page N-Please reference the precise dataset names established and tabulated New notation is being used to clearly identify each data se1, 21 1 paragraph, line earlier in the report. and the section number where they were defined. and is properly referenced herein. 4 271. Section N 2. Page N-Please explain why the California database used for DCPP is not also a See answer to comment 69.Now we have a unique global 1, 1st Paragraph of viable dataset for regional Arizona sources. PhiSS -RSO model Section, Last Sentence 272. Section N.2.1, Page N-1. Please explain why the use of 3 recordings per station is sufficient to See answer to comment 220 1st Paragraph of Section, define a site term (especially since 5 recordings were used for other 1st Line aspects of the study as reported elsewhere in 1he report). 273. Section N.2.1, Page N-1. Please replace Lin et al. (2010) with Lin et al. (2011 ). Typo is corrected 1st Paragraph of Section, 2nd Line 274. Section N 2. 1. Page Judging from the identical values of N.1andM1. the global dataset Text is revised to clearly identify the unique data set. N-1 , 1" Paragraph, used in this Appendix is the same as the dataset used in Appendix M. Is Lines 6 and 7 it necessary to repeat the same plots and table here (an issue because of the two appendices instead of one)? It will also help if each dataset is precisely defined and given a unique identifier early in the report and referred to consistently by that identifier thereafter. 275. Section N.2.1, Page The language "on average of 1,200-1, 700 recordings 1,460 recordings Text is revised to remove the verbiage "1.460 recordings" N-1 , 1 '1 paragraph, from 72-106 earthquakes" is incomprehensible as written. Please clarify. Lines 5 and 6 276. Section N 2.1. Page Same comments about Figure M-1 are also applicable to Figure N.1 Agree. See answer to comment 244 N-1 , 1 *1 Paragraph, Lines 7 (Figure N.1) 277. Section N 2.2. Page Please reference the precise dataset names established and tabulated Proper reference to univoquely identified data sets is N-1 , 1 *1 paragraph, earlier in the report, and the section number where they were defined. provided lines 3-4 278. Section N 3.1. Page There appears to be a trend with magnitude when the entire magnitude The M dependence is not significant, in that is much smaller N-2, 1st Paragraph of range is taken as a whole. Please provide a quantitative definition of than the uncertainty in the constant shown in Figure N.4. All Section, 3rd Sentence what is meant by "significant" and how this definition supports the Tl of the points in figure N.3 are accommodated in the Team's assessment of assuming magnitude-independence of uncertainty range shown in Figure N.4 279. Section N 3.2. Page Please see previous comments regarding justification of the use of a chi-See comments for the new Appendix P N-2. 1st Paragraph of square distribution and the specific value for the GOV. Please also Section, 2nd and 3rd provide a basis for the "assumption" that the GOV for the European data Sentences is the same as for the global data. 280. Section N.3.3, Page Please explain the difference in the cl>ss model (derived from the same Now we have only one Phi_global_r50 applicable to both N-2, First Paragraph global dataset using the same methodology) between the greater AZ sites (Table N.3) and the DCPP (Table M.2). Please also explain the use of different assumption about period dependence for smoothing across periods (there is no period dependence for AZ). 281. Section N 3.3. Page Please see previous comments regarding use of the chi-square See comments for the new Appendix P N-2, 1 *1 paragraph of distribution and the specific value for the COV. Please also clarify section, line 2-4 whether hazard is sensitive to the COV value and whether there is significant uncertainty in selecting the value. 282. Please provide a reference to the sensitivity studies that show the References to new deaggregation plots inserted in Chapter 4 Section N 4. Page N-magnitude and distance ranges that control the hazard. are provided 2, 1st Paragraph of Section, 1st Sentence 283. Section N.4, Page N-2, Please reference Figure N-6 for a definition of regions 1, 2, and 3. Proper reference to a figure defining the Regionalization is 1st Paragraph of Section. provided. It is included in Chapter 4. 3rd Line 284. Section N.4. Page N-Appendix L refers to records in the distance range 200-500 km (section The selected distance ranges reflects the available data 2, 1"' paragraph of L.2). Please explain why a different range is used here. Same comment ranges. We needed a big enough range to have sufficient section, line 4 applies to Line 3 on next page, and Line 3 of section N.5. data to constrain the path effects while keeping our focus on the applicable range. For the global PhiSS model. the GMPEs are less reliable beyond 400 km. Clarifying text is added. 285. Section N.4. Page N-Please explain why this renders the CB 14 model unusable at large See reply to comment 70 2, 1st Paragraph of distances. Section, 2nd Sentence 286. Section N 5. Page N-Please see previous comments on justification of the chi-square See comments for the new Appendix P 3, 1st Paragraph of distribution and use of the specific value of the GOV, and the Section, 3rd and 4th presentation of logic-tree branch weights. Sentences 287. Section N.5, Page N-Please discuss the cause of the decreasing trend of cl>ss with period at The decrease trend is an empirical observation. We do not 3, First Paragraph. large distances (ie., for sources in Regions 1, 2. and 3), as shown in have an explanation for this trend Lines 7 and 8 Figure N.8. 288. Section N.6, Page N-Please correct the date of this publication to 2014a to agree with the Reference was corrected 3, 2nd Reference published date of the manuscript 289. Section N.6, Page N-Please correct the date of this publication to 2014b and include the Reference was corrected 3, 3rd Reference volume and page numbers of the published version. 290. Table N 3. Page N-6 Please correct the heading of the second column from 'CA data' to Table heading is corrected 'European data'. 291. Table N.1, Page N-5, Please clarify whether this table also includes the Taiwanese recordings Yes, that includes the Lin et al (2011) data. Text is provided Caption from the Lin et al. (2011) study. in the caption 292. Figure N.5, Page N-Please explain why only five periods are shown in this figure. These are the periods available for the Lin et al. (2011) data 10 set 293. Figure N.7, Page N-Please check the accuracy of these plots. Plots were checked for accuracy 12 294. Figure N.8, Page N-Please correct the caption to indicate that the figure is for sources in Caption was corrected 13, caption Regions 1, 2, and 3 (not 4 ). APPENDIX R Spatial Correlation 295. General Please consider formatting this appendix for consistency and visual This appendix documents work by Shahi to update his uniformity with the rest of the report (font: section. equation and page previous evaluation of the effect of the spatial correlation on numbering style, etc) the phi and tau It is an independent deliverable that is not part of the Tl Team report. Therefore. it is not up to the Tl Team to rewrite the deliverable. To make this difference clear, it is changed from an appendix to an attachment. The detailed comments (296 to 320) have been provided to Shahi for consideration in revising the deliverable 296. Abstract, Page 1, Line Please consider revising this sentence to reflect the fact that only the Done 7 model of aleatory variability was refitted. the coefficients of the median relation were fixed to the values estimated by Chiou and Youngs (as stated in Section 3, Page 4, First Paragraph). 297. Section 1, Page 1, Please consider changing the word "prediction" to "modeling". Done First Paragraph, Last Line 298. Section R. 1, Page 2, ?e appears to be the same as what is elsewhere in the report called '* The reviewer is correct in noting that \phi_e and \tau 1** paragraph, Line 8 Please make changes here. and elsewhere in the appendix. to ensure represent the same thing. We have included the following in that the notation is consistent throughout the report. the text to help the readers "traditionally $\phi_{e}S is also represented by the symbol $\tau$". We decided against changing the notation everywhere in the report because we strongly feel that using the same greek letter to denote standard deviation component is a more consistent notation. 299. Section R. 1, Page 2, Please clarify the importance of these two sentences in the context of We have added the explanation that regions refer to data 1st Paragraph, last 2 the present study. and clarify whether "regions" refers to spatial regions sparse regions in parameter space. We use the fact that sentences (e.g., California or Japan) or regions in ground-motion parameter space these median model coefficients are not pure statistical fits, (e.g., ranges of magnitude and distance). and the result from Jayaram and Baker (2010) to justify our assumption of not letting the median model coefficients to change. 300. Section R. 1. Page 2, This sentence is confusingly worded because it does not indicate for Thanks for pointing out the confusing sentence. The revised 2"' paragraph, 2"rl what pairs of things correlations are being modeled. Please reword for sentence reads "Though spatial correlation of ground-motion sentence clarity (for example. "models the correlation of ground motion intensity intensity at two sites is not explicitly considered, the between sites ... "). between-event residual $\delta_ es is shared by every recording from an event and thus implicitly models the correlation between the intensity of motion due to common eventfsource effects." 301. Section R. 1, Page 2, Please quantitatively define what is meant by "significantly". We have added the explanation that (Jayaram and Baker, 2nd Paragraph, 14th 2010, showed that the standard deviation components Line chanae bv over 10%). 302. Section R. 1. Page 2, Please replace "NGA West 2" with NGA-West2" to be consistent with Done 2nd Paragraph, 17th the acronym used by the NGA project and used elsewhere in the report Line and aooendices. 303. Section R. 1. Page 2, Please change this citation to "(Ancheta et al .. 2014)" to be consistent Thanks. We have changed the citation. 2nd Paragraph, Last with the published journal article. or alternatively reference both the Line PEER report and the journal article. 304. Section 2, Page 3, The statement that a magnitude-dependent model is "closer" to the truth The motivation behind this statement comes from the fact First Paragraph, 1"' than the magnitude-independent model seems to contradict the Tl that several NGA-West2 models use a magnitude dependent sentence Team's assessed branch weights in the GMC logic tree (equally functional form for their aleatoric uncertainly models (e.g., weighted in Fig 11.1, 12.1, 12.2, and binary weighted in Fig 10.1 ). ASK, CY, CB). Our statement is made in the context of Please revise or explain how this sentence is consistent with the Tl ground motion models in general, whereas the Team's assessment of these two alternatives. Please also provide a recommendation of the Tl team may be appropriate for this reference to publications by the cited "ground-motion modelers" that particular project. suggest magnitude dependence. 305. Section R.2, Page 3. Please describe what simplifications were made to the Chiou and We do not include the effects of soil non-linearity on 2nd Paragraph, 1st Youngs (2014) variance model for the present study. variance. The text is updated to note this simplification. Sentence 306. Section R.2. Page 3, Please define what the symbols "s" and "t" refer to in Equations (3) and We have updated the text to include that s_ 1, s_2. t_ 1, and 2nd Paragraph, 3rd (4). t_2 are model coefficient fitted from data. Sentence 307. Section R.2. Page 3, It might be useful to clarify parenthetically that "s" and "s prime" Done 3rd Paragraph, 4th mentioned here is not the same as "s" in Eq. (4). Line 308. Section R.2. Page 3, Please justify why the equations for "r" given by Jayaram and Baker In their report Baker and Jayaram studied the spatial 3rd Paragraph. 9th (2009) are also appropriate for the within-event residuals of CY14. correlations computed for several well-recorded Line earthquakes. Their results show that the value of the range parameter (r) has similar value across earthquakes if the Vs30 values are not clustered together. 309. Section R.3, Page 4, Please explain why the results of Jayaram and Baker (2010) and Hong Baker and Jayaram explain how including spatial correlation 1st Paragraph, 2nd et al. (2009) are robust enough to permit assuming that the CY14 changes the values of the values of the inter and intra event Sentence coefficients will not change. standard deviation without changing the total standard deviation. Since the total standard deviation does not change significantly, we do not expect large changes in the total residuals. Thus. we should not expect large changes in the median model coefficients. 310. Section 3, Page 4, This equation (Eq. 8) seems to be a duplicate of Eq. 2. Please review it The reviewer is correct in noting that equations 2 and 8 are First Paragraph, Line and make clarifications as needed. duplicates. These equations serve different purpose in the 8 two places. Equation 2 represents the relationship between the total residual, the within event residual, and the between event residual. Whereas equation 8 shows how assuming that the coefficients of CY14 model do not change simplifies regression the problem into a residual splitting problem. 311. Section 3, Page 4, Please review whether "I)_." in these equations should really be "i:.s, and Thanks for catching the typo. The \delta_{ es} should have Second Paragraph, consider clarifying the intent of these equations. been \epsilon_{es}. We have added text to explain how these Lines 3 to 5 (Eq. 9 to equations are used to fit model coefficients Eq 10) 312. Section R.3. Page 4, Please provide a published statistical reference for Eqs. (9). (10), and Equations 9, 10 and 11 are mathematical truth derived from 2nd Paragraph, (11 ). assumptions stated in the report (after we fixed the typo). Equations (9) to (11) They stand without any need for citations. 313. Section 3, Page 4, Please justify the assumption of non-correlation in light of the presence The assumption is made to make the computation tractable Third Paragraph. of a site-specific term, which could induce correlation between residuals This is an assumption used in all ground motion models that Lines 3 and 4 across different events recorded at the same site. do not include the site term. This includes CY14 models. 314. Section R.4, Page 5, The standard deviations derived without considering spatial correlation We agree with the reviewer that the comparison of standard 2nd Paragraph, 1st should have been similar to those obtained by CY14. Please show that deviations without correlation with the standard deviations Sentence this is the case or, if not, why not. from CY14 model can be a good validation test, and including this will improve the quality of the report. This comparison is difficult to make here because we use a simplified form of the standard deviation model. For example, the CY14 standard deviation models include the effects of soil nonlinearity, which is completely ignored in this report. Any comparison without adjusting for the effects of simplification will not be meaningful and may end up confusing the reader. These adjustments are non-trivial and are outside the scope of this mini report. We will try to derive a good scheme to adjust for the model simplifications and include the suggested comparison in a future publication. 315. Section R.4. Page 5, Please clarity whether "these results" refers to the homoskedastic or The results refer to both homo-and heteroskedaslic models. 3rd Paragraph, 1st heteroskedastic results, or both. Line 316. References, page 5. 4'" reference Please provide a volume number for this reference. Done 317. References. Page 6, Please update this reference to include volume and page numbers Done 3rd Reference 318. References, Page 6, Please provide a more complete reference (e.g .* conference dale, Done 6th Reference conference proceedings title, publisher, etc.). 319. Table 1, Page 7, Please clarify that these are "standard deviation model" coefficients, and Adding the word "standard deviation" with model coefficients Caption not median model coefficients. is slightly confusing, as model coefficients are estimates and have their own errors and standard deviations. The report is focused on standard deviation models, and it is the only model we fit. It is clear from context that the coefficients are for the standard deviation model and not any median model. We did not change the table title to avoid any potential confusion. 320. Table 2, Page 8, 5th The value "0.367" appears to be a typo. Please verify this value and Thanks for catching the typo. We have corrected it to 1.008 Row, 3rd Column revise accordingly. Comment Response Table Comment Location in PPRP Comment Summary of Revisions to Report Number Text CHAPTER 6 GMC Models for the Median 321. Section 6.1, Page 6-1, The "base-model GMPEs" are called by other names-e.g., "proponent Done mostly throughout the report (Rev.1) and completed (Rev. First Paragraph, First Line GMPES", or "selected candidate GMPEs (as in the next paragraph of 2) this section) -in other parts of the report. Please select an appropriate name for these GMPEs and consistently use this name throughout the report and appendices. If "base model" is intended to mean something else in this context, please define this term the first time it is used and include it in the list of terms. 322. Section 6.1, page 6-1, Please explain the concept of a "space of GMPEs," or make it clear that We refer to the Draft PEER report on epistemic uncertainty paragraph 2, line 2 this is a concept that is going to be fully explained later in the chapter, (Attachment E for Rev.1. Introduction to Appendix H for Rev.2) and reference the section where the explanation is given. It would also for a comprehensive overview of the Sammon's map approach be advisable to develop a terminology that distinguishes actual GMPEs and reasoning from the virtual GMPEs constructed from the common form, as the lack of consistent, distinct terms for these entities is a frequent source of ambiguity in the rest of the chapter. 323. Section 6.2.1, Page 6-1, Please replace "Akkar et al. (2013, 2014 )"with "Akkar et al. (2014a,b)" Citations in text/tables/figures and references list are fixed 2nd Bullet here and elsewhere throughout the chapter to indicate that both the throughout the report original manuscript and the erratum were published in the same year. 324. Section 62.1. page 6-1. Idriss (2014) is referred to here as 114, whereas it is ld14 in the figures Done 6'" bulleted item and elsewhere in the text. Please make these acronyms consistent. 325. Section 6.2.1, Page 6-1, Zhao and Lu (2011) is not a GMPE, but a method for accounting for Done 8th Bullet saturation of magnitude scaling. Please summarize how this magnitude scaling is used to construct a GMPE for purposes of 1he Tl Team's evaluation and provide a more meaningful description and acronym for this model. 326. Section 6.2.1, page 6-2, Please indicate quantitatively what is meant by "large magnitude" in this Done 1st paragraph on page, context. line4 327. Section 62.1. Page 6-2, Please provide a reference for the finite-fault simulations (e.g .. Appendix Done 2nd Paragraph on page, J as well as citations to references in the list of references). 2nd Sentence 328. Section 6.2.1, Page 6-2, Please provide a more complete citation to "Idriss". Fixed: now reads "Idriss (2014)" 3rd Paragraph on page. 10th Line 329. Section 6.2.1. page 6-2, Please provide additional justification for the exclusion of 114 at Done 3'" paragraph on page, distances less than 3 km, beyond its status as an outlier relative to other last sentence GMPEs and simulated data. 330. Section 6 2. 1. page 6-2. Please check the magnitude of the Kocaeli earthquake. which is given Done 4*h paragraph on page, as 7.51 in the NGA-West 2 flatfile. line 2 331. Section 6.2.1, page 6-2. Please include a reference to the report section (and figure number if Done S"' paragraph in section appropriate) where the sensitivity result cited here is demonstrated. (last on paQe), Line 1 332. Section 6.2.1, page 6-2. The figure is for a relatively long period (0.5 Hz), so it would be helpful We refer to the previous hazard deaggregation results shown in 5"' paragraph in section, here to complete the argument by recalling that the long periods are the Chapter4 Line 4 worst case for hazard sensitivity at this distance range (and to reference the report section and figure(s) where that is demonstrated). 333. Section 6 2. 1. page 6-2. Please provide a more precise statement of what is meant by "the Done last paragraph of page, candidate GMPEs is reasonable for application to DCPP" and provide last line the justification for this judgment, or a reference to the report section where this justification is given. 334. Section 62.2. Page 6-3, Please replace "Bindi et al. (2014)" with "Bindi et al. (2014a,b)" here and citations in text/tables/figures and references list are fixed 3rd Bullet elsewhere throughout the chapter to indicate that both the original throughout the report manuscript and the erratum were both published in the same year. 335. Section 62.2. page 6-3. Please explain more fully the justification for excluding the Bindi et al. The text seems clear -reference to figure 6.6.2-1 is provided 1*1 paragraph of section, (2014) model, or provide specific reference(s) to the section(s) where lines following bullets that justification is fully explained, and explain whether ASB 14 has similar limitations. 336. Section 6.2.3, page 6-3, Please reference more specifically-section number, and figure number Done 1** paragraph of section, if appropriate-where the sensitivity result cited here is demonstrated. Line 2 337. Section 6.2.3. page 6-3. Please state quantitatively what is meant by "large magnitude" in this Done 1** paragraph of section, context. Line 3 338. Section 6.2.3, page 6-3. The structure of the final sentence of the paragraph is a little awkward Done paragraph 1 of section, (particularly its formulation as a rhetorical question), and the expression lines 4,5 "large distance attenuation" is ambiguous in meaning. Please consider rewriting the sentence to improve its clarity and precision. 339. Section 6.2.3, Page 6-3, Please replace "Kashida et al. (2014a)" with "Kashida et al. (2014)" here citations in text/tables/figures and references list are fixed 2nd Paragraph of and elsewhere in the chapter to reflect the fact that there is only one throughout the report Section, 3rd Line such reference listed in the references. 340. Section 6.2.3. Page 6-3, Please explain how the California event terms were calculated, or The event terms were provided by NGA modelers. Clarifying 3rd Paragraph of Section. provide a reference to the report section where the explanation is given. text was added Last Sentence on page 341. Section 6.2.3, page 6-4. Here and elsewhere, "California/Mexico" should read "California and Edits applied paragraph 4 of section Mexico" for clarity. Same in the next paragraph where "southern/central" (2"d on page), last line should read "southern and central " 342. Section 6.2.3. Page 6-4, Please include the Phillips et al. (2013) reference in the list of this reference has been added (which is Phillips, 2014)--text last paragraph of section, references. changed accordingly 2nd Line 343. Section 62.3, page 6-4. The strong frequency dependence of Q evident in Figures 6.2.3-2 and Clarification added 5"' (last) paragraph of 6.2.3-3 increases the differences between California and Arizona Q at 5 section, last sentence Hz (upper left panel of each figure), so please reference the sensitivity studies that demonstrate the absence of hazard significance at 5 Hz for California sources. 344. Section 6.3, general The relegation of part of the hanging wall discussion to Appendix K is Appendix K was integrated into Chapter 6 somewhat awkward and inefficient. Please consider integration of the material from that appendix into the various subsections of 6.3. 345. Section 6.3, Page 6-5. 1st Please include the Abrahamson and Silva (2008) and Campbell and References added Line on page Bozorgnia (2008) references in the list of references. 346. Section 6.3, page 6-5. The statement that Rjb implicitly accounts for the hanging wall effect Sentence revised to clarify this point last paragraph of section, could be seen as contradicting the result noted later that the Rjb last sentence distance metric alone does not account for the dip-dependence of the hanging wall effect. Please modify this statement to note that Rjb does not agree with simulations for shallow-dipping scenarios and reference the sections of the report where this is discussed. 347. Section 6 3.1. page 6-5. Please consider whether "moderate" is a better descriptor than Done 1** paragraph, Line 3 "average", in order to avoid the suggestion that this is a rigorous statistical measure. 348. Section 6.3. t, Page 6-5, Please explain why the Rjb-based ASB14 GMPE was not used to Clarification added 1st Paragraph of Section, evaluate HW effects, given that the Rbj-based BSSA14 GMPE was 4th Sentence found to be suitable. 349. Section 6 3.1. Page 6-5, Please provide a specific reference to the report section that describes Done 2nd Paragraph of the "additional simulations" that were done for the SWUS project. Section, 1st Sentence 350. Section 6.3.1, page 6-6. The phrase "Moves off of the hanging wall" is ambiguous, as it does not Sentence revised 3*d paragraph of section make it clear whether the reference is to distant points still on the (1'1 on page), line 3 of hanging wall side of the surface projection of the top of the rupture, to paragraph points on the footwall side of the surface projection of the top of the rupture. or to both. Please clarify. 351. Section 6.3. t, page 6-6, The phrase "Moderate magnitude scaling" is ambiguous. Please clarify; Done 3'" paragraph of section for example, if the intent is to refer to scaling at moderate magnitudes, (1 on page), line 5 of please hyphenate as in the phrase "moderate-magnitude scaling." paragraph 352. Section 6 3.1. page 6-6. The notion of "magnitude taper" has not been defined. and by itself is Sentence revised to clarify this point 3*d paragraph of section ambiguous. Please clarify. ( 1 "1 on page), 2*** to last sentence 353. Section 6.3.1, page 6-6. The discussions in Appendix J (Pages J-41 and J-42) and Appendix K Sentence revised 3*d paragraph of section (Section K.1.2) suggest that the magnitude tapers of ASK14 and CB14, ( 1 *1 on page), second to but not CY14, are too strong compared to the magnitude scaling of the last sentence HW effect revealed by the simulated data Please revise this sentence to reflect the conclusions described in Appendix J and Appendix K. 354. Section 6 3.2. Page 6-6. At this point in the chapter the Rjb-based models have not been Reference to "Donahue and Abrahamson" provided 1st Paragraph of Section. eliminated as being inappropriate. Please explain why the Rjb-based 2nd Sentence models are not used in developing the HW model. 355. Section 6 3.2. page 6-6. The scaled-backbone approach has not been defined nor is a reference Reference provided 1** paragraph of section, cited. Please correct this. Line 4 356. Section 6.3.2, Page 6 -6, To avoid misinterpretation, please include text to note that, although a Text included First Paragraph, Last magnitude taper was not explicitly included, Eqs. (6.3-1) and (6.3-2) still Sentence provide a magnitude scaling of the HW effect, as was explained in Appendix J (Page J-42). 357. Section 6.3.2, Page 6-6, Please clarify how the total hanging wall effect is to be modeled by the 3 they are multiplicative factors, formula is now fixed 2"c paragraph of section, equations (e.g., is it the product of the three factors defined in these Eqns 6.3-1.2,3 equations?), and also define the variable "W". 358. Section 6.3.2, Page 6-6, Comprehension of this sentence depends upon familiarity with Appendix Not a problem anymore because the Appendix K is now 3rd paragraph of section, K. For example, it does not make sense to say "Five equally weighted integrated with Chapter 6 line 1 alternative HW factor models were developed ... ",because, logically. models have to be developed before they can be assigned weights. Nor is it clear what is meant by equal probability of the C 1 coefficient. Please rewrite and expand the text to make this section sufficiently self-contained to be understandable. 359. Section 6.3.2, Page 6-6, The terminology "weighted factors" in Lines 2 and 3, is a source of Not a problem anymore because the Appendix K is now 3rd paragraph of section, confusion, and without familiarity with Appendix K, the sentence is integrated with Chapter 6 2"" sentence incomprehensible. Please reword and expand for clarity, and give a more specific reference to the relevant appendix subsection(s). Please note that this is a place where the division of the material between the chapter and the related appendix seems especially inefficient. 360. Section 6.3.3, Page 6-7, Please indicate that additional comparison plots similar to Figure 6.3.3-1 Not a problem anymore because the Appendix K is now 1st Paragraph, 4th are given in Appendix K. integrated with Chapter 6 Sentence 361. Section 6.3.3, Page 6-7, The assessment that Rjb-based HW models are not appropriate for Discussion added 2nd Paragraph shallow dips is important. Please provide an example plot to show that these models are not appropriate and that Rrup-based models adequately model HW effects. and reference where in the report or appendices the discussion of this topic can be found. 362. Section 6.4, Page 6-7, Please explain the following: What does "mutually exclusive" mean? Are Discussion added First Paragraph, Third the candidate GMPEs mutually exclusive? Why is it important to use Line mutually exclusive GMPEs for the characterization of the CBR of median amplitude? What are the impacts on hazard if GMPEs are not mutually exclusive? 363. Section 6.4. page 6-7. 1" "Sammon's mapping" is called "Sammon's map" in Section 6.1. If there Consistent terminology used throughout the report paragraph of section, is no distinction between these. please use a consistent terminology. 11 364. Section 6.4. Page 6-7. The term "base model" has not been defined at this point in the chapter. Definition provided 2nd Paragraph of Please define the term "base model" the first time it is used and include Section, 1st Line it in the list of tenms. 365. Section 6 4. 1. Page 6-8, Please expand this sentence to explain why a common functional form Discussion added 1st Paragraph of Section, for all of the candidate models is needed or reference appropriate 1st Sentence sections in an appendix where this information can be found. 366. Section 6 4. 1. Page 6-8, Please indicate what is meant by the phrase "induces a distribution of Discussion added 1st Paragraph of Section, GMPEs", and indicate where in the chapter this concept will be 3rd Line expanded upon. 367. Section 6 4. 1. Page 6-8, There could be confusion when the term "models" is used between Consistent terminology used throughout the report 1st Paragraph of Section, whether this refers to the candidate GMPEs or to the simulated GMPEs. 7th Line Please select a common terminology for these two types of models and use this terminology consistently throughout the report and appendices in order to avoid confusion. 368. Section 6.4. 1. Page 6-8, Please be more specific by what is meant by "scaling". If it refers to the Clarification provided 2nd Paragraph of scaling terms in the GMPEs, please consider replacing "scaling" with Section, 3rd Line "scaling terms" here and elsewhere in the report and appendices. Please also qualify what type of scaling is meant when the term is used elsewhere throughout the report and appendices. 369. Section 6.4. 1, page 6-8, Please define NML as an acronym for "normal" here if this is the first Done 2"c paragraph of section, 4"' line after Ean 6.4-1 time it is used and include it in the list of terms. 370. Section 6.4.1, page 6-8. Please define the acronym "SS" (implying strike slip) the first time it is Done 2"" paragraph of section. used and include it in the list of terms. 8111 line after Eqn 6.4-1 371. Section 6 4. 1. page 6-8. Please clarify what SS NML and SS REV mean and replace "based on Sentence rewritten to improve clarity 2"' paragraph of section, the scaling in the eight candidate GMPEs" with more precise language. last 2 sentences Also explain why the specific scenarios for estimating SS:REV and SS:NML factors are appropriate and if the results are sensitive to the choice of the selected scenario. Please also explain why the same scenario is appropriate for both DCPP and PVNGS, considering that their hazard is impacted by potentially different magnitudes and distances. 372. Section 6.4.1, page 6-9. Please indicate what function is being referred to in the statement '"this New figures have been inserted showing filling of common-form 3*d paragraph of section, function," and by whom it is considered to have the stated flexibility. If GMPEs to candidate GMPEs, and Mand R residuals for the ( 1 *1 on page) lines 2 and this is the assessment of the Tl Team, please say so, and provide the scenarios used for the fitting 3. basis for this judgment by demonstrating that Eqs. (6.4-1) and (6.4-2) are flexible enough to capture the full range of scaling of the selected candidate GMPEs. That might entail, for example, showing the misfits to the original GMPEs as a function of magnitude and distance. Also, please discuss whether the misfits to the original GMPEs significantly affect the hazards, or reference the report section where such a discussion is provided. 373. Section 6 4. 1. Page 6-9, Please explain why this transformation of coefficients is necessary and Explanation added 3'" paragraph of section how it leads to squared coefficient terms in Eq. (6.4-2). (1st on page), 3rd Sentence 374. Section 6 4.1. page 6-9. Please check the equation. Shouldn't a6(7) be squared? Yes, it should be squared 3'd paragraph of section (1 on page), Eqn 6.4-2 375. Section 6.4.1, Page 6-9, Please clarify what the phrase "the square" refers to with respect to Eq. Clarification added 3*d paragraph of section (6.4-2) and/or the definition of the model coefficients. (1st on page), 13th Line 376. Section 6.4. t, Page 6-9, The intended point of this sentence is unclear. Please revise to make it Sentence rewritten to improve clarity 4*h paragraph of section clear. (1" paragraph after Eqn 6.4-2). 1*1 sentence 377. Section 6 4. 1. Page 6-9, Please justify that the Ztor effects of the ASK14, CB14, and CY14 Ztor is not used in Rjb-based models, but the effect is captured 4'" paragraph of section GMPEs are adequately captured by the common-form models with a8 = in the Rrup-based models (1 paragraph after Eqn 0. 6.4-2), znc sentence 378. Section 6.4.1. Page 6-9, Please describe what the three Ztor values are supposed to represent Weights for the Ztor values given 4'" paragraph of section and how they were used in the regression analysis (e.g., were they ( 1 "1 paragraph after Eqn equally weighted or weighted by some other probability distribution). 6.4-2), last sentence Also please revise the reference to the Ztor model of CY14 to be more specific (e.g., "the Ztor-M relationship developed by CY14"). 379. Section 6.4.1.1, page 6-9, The explanation in this section is incomplete, in that it is never explicitly Section restructured to improve clarity general comment stated that numerical log(Sa) predictions of each GMPE, for the given M and Rx set. are used as data to determine a best-fitting coefficient vecto1 for the common form to that GMPE, nor what fitting criterion is applied. Please make the explanation more complete. This same comment applies to Section 6.4.1.2. 380. Section 6.4.1.1, Page 6-9, Please explain what is meant by the phrase "for comparison of the Sentence and section went through major reconstruction -the 1st Paragraph of Section. GMPEs". specific verbiage in the comment has been modified 3rd Line 381. Section 6.4. 1. 1, Page 6-9, Please explain how predictor variables Rrup and Rjb were determined, We added a clarification on how the geometry was construc1ed 1" Paragraph, first 2 lines given M and Rx, and clarify who the '"developers" are (e.g., the NGA-given M and Rx after the bullets West2 developers or the candidate GMPE developers meaning the Tl Team) 382. Section 6 4. 1. 1, Page 6-The phrase" ... is only included to constrain the fitted models at large Clarification added 10, 1" paragraph, 1" line distances ... " has the connotation that the large-distance scenarios are on page used in a limited fashion in the fitting process. Please clarify and revise this paragraph as needed. 383. Section 6.4. 1. 1, Page 6-Please provide a reference in the report or appendices where the Done 10, 1st Paragraph, 3rd definition and calcula1ion of "hazard-relevant" scenarios can be found. Line 384. Section 6.4. 1.2, Page 6-Please clarify who the "developers" are (e.g., the NGA-West2 Done 10. 1st Paragraph of Section, 2"" line after the developers or 1he candidate GMPE developers meaning the Tl Team). bullets 385. Section 6.4.1.2, Page 6-Please explain the basis for "assuming" a 50-degree dip and indicate 50 degrees is a value consistent with the SSC models. 10. 1st Paragraph of Section, 2"" line after the whether the results are sensitive to this assumption Sensitivity on that assumption was not evaluated bullets 386. Section 6 4.2. General To provide more complete documentation. please list the covariance The covariance matrices are provided as electronic attachment matrices in Appendix H. to Appendix H 387. Sections 6.4.2 and 6.4.3, The method used to generate the simulated GMPEs and project them See answer to 387. Also, the methodology is described in the General comment onto Sammon's maps is new and requires detailed documentation to report (Attachment E for Rev.1; Introduction to Appendix H for fully understand the methodology. Please provide more detailed Rev.2) documentation on the generation of the covariance matrices, the simulated GMPEs, and the Sammon's maps. including all related equations, either in Chapter 6 or in an appendix. 388. Section 64.2. page 6-tO, This short section is mainly devoted lo describing the use of Title changed section title interpolation to facilitate the estimation of the coefficient correlations. It is not clear what the title "generation of models" refers to. In the subsequent section (6.4.3), model generation seems to refer to the sampling of the coefficient space to create sample GMPEs. so the use of "model generation** as the title of Section 6.4.2 seems confusing. Please consider changes to remedy this confusion. 389. Section 64.2. page 6-tO, Please explain the difficulties encountered in estimating the correlations The Kullback-Leibler-divergence approach was used to respond 1** paragraph of section, of the coefficients using the original GMPEs alone. and justify how it is to this question. Text added to the report. sentences 2,3, and line 5 mathematically possible with the addition of the interpolated GMPEs to better capture the correlations. Also provide the rationale for the interpolation weights selected, and clarify whether the interpolation was done by interpolating the coefficients or by interpolating the ground motion vectors and refitting to the common form 390. Section 64.2. page 6-tO, The last set of weights (2/3, 1/2) do not add to 1, while the other two It was a typo and it has been changed 1" paragraph of section, sets do add to 1. Please review and revise as needed. line 5 391. Section 6.4.2, Page 6-11, Is this approach (for treating the case T>3 sec) mentioned for the first Reference added at the beginning of Chapter 6 2"" Paragraph of section time here? If so, please add a paragraph in Section 6.1 so the readers ( 1 *1 on page). Last are aware of it from the very beginning. Sentence 392. Section 6 4.3. page 6-11, Please add an explanation of what is meant by model generation and Section rewritten to improve clarity 1** paragraph of section how it is done At this point, for example. there has been no explicit (1 on page), 1" sentence explanation that models in this section are generated by sampling the on page common-form coefficient distribution estimated in the previous step, nor have any necessary assumptions about the joint distribution of the coefficient distribution been explicitly stated. 393. Section 6.4.3, page 6-11, Please clarify what is meant by "for a few scenarios. Doesn't Figure Scenario clarified in text and labeling 1" paragraph of section, 6.4.3-1 apply to just a single set of predictor variables (i.e., a single 3'd sentence value each for magnitude, distance, and style of faulting)? In addition. please state what predictor values were used (that information should be in the figure caption as well). 394. Section 6 4.3. page 6-11, Please indicate by whom the judgment was made. and on what basis. Clarifications added 1" paragraph of section, and consider whether "range" is the appropriate term here, as opposed last sentence of to, e.g., "distribution" or "center, body, and range" (there are other paragraph instances throughout the report where the usage of "range" should also be reviewed and revised where appropriate). 395. Section 6.4.3, page 6-11, Please clarify whether the good agreement seen in the example We show a new figure where we plot the standard deviation 1 paragraph of section, scenario was also observed in all other scenarios important to the from 7500 and 2000 models for all scenarios in the vector. last sentence of hazards at DCPP and PVNGS. paragraph 396. Section 6.4.3. page 6-11, Some explanation of the nature of the Sammon's map should precede The structure has been reorganized 3'd paragraph of section, this instance of its application. Please consider doing some 1** sentence reorganization of this section to put the developments in a more logical order. 397. Section 6 4.3. page 6-11, The range of values of the Sammon's map coordinates in Figure 6.4.3-2, Changes applied to Chapter 6, 8 and 9, as applicable 3'" paragraph of section, for the original GMPEs, is roughly plus/minus 10. This is more than an 1" sentence order of magnitude greater than the range shown in, e.g., Fig. 9.1-3b of Chapter 9. Please explain the reason for the difference. Also please explain the reason for the difference in axis labels in different parts of the report, i.e .. "C1 ,C2" is used here and in Chapter 9. versus the axis labels "In units" shown for seemingly analogous plots in Chapter 8 and Annendix H. 398. Section 6.4.3, Page 6-11, Please explain why there is a trade-off between the "likelihood and an Explanation has been provided, and entire sentence is now in 4th Paragraph, Last 2 optimized standard deviation", what the sensitivity of the results is to Chapters sentences using a fixed standard deviation, and what the rationale is for selecting that value from BSSA 14 over the other GMPEs. 399. Section 6.4.3, Page 6-11, Please describe the Tl Team's reasons for including the simulated data Explana1ion has been provided, and entire sen1ence is now in 5'h Paragraph, 1" in the model evaluation, or point to the section where those reasons are Chapters Sentence described. 400. Section 6.4.3, Page 6-12, Please provide a reference for 1he "80% and 20%" proportions of relative Explanation has been provided, and entire sentence is now in 2nd Line on page rates of normal and strike-slip mechanisms for the Arizona sources. Chapters 401. Section 6.4.3, page 6-12, Please rewrite this sen1ence to improve clarity. It is not clear wha1 part of Sentence rewritten to improve clarity 7'h paragraph of section the analysis was done using the central HW term, nor at what stage the (2" on page), 2°d and 3*c random HW models are introduced instead, nor why this two-stage sentences analysis method was chosen. 402. Section 6.4.3, Page 6-12, Please provide citations for principal component analysis and Sammon's They are provided in the beginning, in Section 6.4. We do not 9th Paragraph of section (41h on page), 1 *1 maps if they haven't been provided previously in the chapter. see reasons to repeat them Sentence 403. Section 64.3. Page 6-12. Please describe the Tl Team's motivation to base the selection of the Goal is to capture the range in hazard. Also look at the scatted 9th Paragraph of section representative model on the resulting hazards, and to select the model hazard from a cell. Figure inserted (4'h on page), 2"d with hazard closest to the mean hazard (as opposed to. e.g .. the median Sentence or another quantile hazard level). Please also describe the scatter in the hazard from models in the same cell. 404. Section 64.3. Page 6-12. Please verify that the simplified SSC models for DCPP and PVNGS No, they are not consistent but they are representative of the 9th Paragraph of section being used are consistent with the final SSC models for these sites. type of sources -We are not meaning to reproduce the same (4th on page), 3'° final hazard as if we were using the final SSHAC L.3 SSC Sentence models. Also, the simplified models were derived before the final SSC models are done. The general features are however comparable 405. Section 6.4.3, Page 6-12, Please explain the basis for selecting the "one specific HW model". Clarification provided 9th Paragraph of section (4th on page), 6111 line 406. Section 6 4.3. page 6-12, The concept of using random HW models in the development of the We have re-written the sentence to explain and justify the two 9'" paragraph of section Sammon's maps for PVNGS and a random HW model assigned after different approaches for OPP and PVNGS (41" on page), last the selection of a GMPE for each cell for DCPP is unclear. Please sentence provide additional explanation of how this method is applied and why it is needed in order to help the reader better understand the methodology. 407. Section 6.4.3, page 6-12, Please clarify what is meant by an approximately uniform distribution of Such statement is made in Section 6.3. The factors are normally 9th paragraph of section hanging wall factors (e.g., according to Appendix K, the HW factors were distributed, but the models are sampling. (41h on page), last developed under the assumption of a normal distribution). and why it is sentence important. 408. Section 6.4.3, page 6-12, Please describe how the outputs of principal component analysis No further explanation will be added in the text, because it has 10'h paragraph of section (presumably, a set of 2-D coordinates) are used as inputs for the been already mentioned before that the methodology is well (5th on page), 1*t sentence construction of Sammon's maps, and provide a reference for the described in the report (Attachment E for Rev.1; Introduction to "principal component analysis and Sammon's maps" methodology that is Appendix H for Rev.2) being used 409. Section 64.3. page 6-12, Please indicate whether the model vector concatenates a set of periods, Section rewritten to improve clarity 101h paragraph of section or a separate model vector is constructed for each of a set of periods. In ( 51h on page), 2"d either case, please indicate what set of periods was used. Also please sentence consider changes to emphasize even more explicitly that the vector space is a space of ground motion valued n-tuples, and to draw a clear distinction between this vector space and the space of common-form coefficient vectors used in the model generation stage. 410. Section 6.4.3, page 6-13, Please rewrite this sentence (and perhaps add additional text) to make Section rewritten to improve clarity 10'h paragraph of section its meaning clear. The explanation should clarify that each vector (1" on page), 1*t full component is a In( Sa) value for a particular combination of predictor sentence on page variables. The lists of predictor values (for DCPP and PVNGS, respectively) should also be given at this point (e.g .. are they the values listed later on this page and called "deaggregation bins" or values listed on Pages 6-9 and 6-10?) Presumably one of those sets was used in the fitting and the other in model generation, but it is difficult for the reader to figure this out. The explanation should also clarify that the analysis is done independently at each period. if that is the case. 411. Section 6.4.3, page 6-13, Please be precise and consislenl in the use of terminology. The symbol Done 101" paragraph of section "w" in this line is defined as the importance of the scenario, bul in lhe (1st on page). 1 *1 line after next sentence it is call the "weight," and later something called Eqn 64-4 "deaggregation weight" is referenced. If these all mean the same thing, the terminology should be consistent; if they do not, their distinction should be clarified. 412. Section 64.3. page 6-13, This line states that the weights are computed from "the deaggregation." Plots showing weights have been added Section has been re-101" paragraph of section But this is the first time "deaggregation" has been mentioned in the written. Approach described in greater details for both PVNGS ( 1 on page), 2nrl line afte1 chapter, so the use of the definite article (indicating something already and DCPP applications. Return periods and a table showing Eqn 6.4-4 introduced) is very confusing. Please rewrite this statement to make it ground motion levels have been added to the texl. clear that a new element is being introduced into the analysis. Please also be more specific than just referring generically to "deaggregation" by saying, e g , "hazard deaggregation matrix" and by specifying what return periods and spectral periods are used to perform the deaggregation. 413. Section 6.4.3, page 6-13, Please clarify what GMPE distribution is referred lo here, and what is Clarification added 10t* paragraph of section meant by "mean model." For example, is this distribution that of the eight (1st on page). 2r.d line afte1 original GMPEs, or of the 2000 virtual GMPEs in the constructed Eqn 6.4-4 ensemble, and is the "mean model" the virtual GMPE that occupies the position in Sammon's map space that represents the geometrical centroid of the original GMPEs? 414. Section 64.3. page 6-13, The term "deaggregation weight" has not been defined. Please explain Entire description of the weights has been redone 101" paragraph of section how ii is related to the deaggregated hazard (e.g., is it some function of (1 on page), 3"' and 4'" the probability of exceedance value at a given ground motion level, or line after Eqn 6.4-4 simply the probability value itself, normalized in some way?). Please also state precisely and quantitatively what was done. and include the defining equation for the deaggregation weighl. 415. Section 6.4.3, page 6-t3, The sta1ement that the mean of the "deaggregation weights" is "used as Formulas corrected for consistency 101" paragraph of section w" in Eq. (6.4-4) is inconsistent with the subsequent explanation in which (1" on page), line after this mean is given a differenl symbol, w_bar, and is used in Eq. (6.4-4 ), Eqn 6.4-4 in combination with the number 1/N, to give w. Please rewrite this statement to provide a precise and consistent explanation. 416. Section 6.4.3, page 6-t3, Please clarify if the "renormalized weights" are used with Eq. (6.4-4) Sentence rewritten to improve clarity 11 t* paragraph of section inslead of the mean of the 10 deaggregation weighls referred lo in lhe (2s1 on page). 3'0 line previous paragraph. 417. Section 64.3. page 6-13, Please explain how it was determined that the defined "deaggregation 1 t'" paragraph of section bins" are sufficient for the purpose of determining the scenario weights. (2" on page), 3rd line afler Equation 6.4-5 418. Section 64.3. Page 6-14 Please explain why only a mean + 3 km increment was used as an Clarification added 141" paragraph of section alternative value for Ztor and not also a mean -3 km increment. Please ( 1 on page), First Line also explain why 3 km was chosen for the increment and whether the alternative value was given a different weight than the mean. 419. Section 64.3. page 6-14, The juxtaposition of the statement that "only one Ztor value is used" for Clarifying text was added to this section 14'" paragraph of section the Rjb-based models, with 1he statement "these models do not include (lop paragraph on page), Zlor scaling," seems illogical. If Ztor does not occur as a predictor 1*1 full sentence variable in a GMPE, it is confusing to suggest that "only one value" of that variable was used. Please rewrite this statement for clarity and nr<>r.i.:inn. 420. Section 6.4.3, Page 6-14, It's not clear how the number 384 is obtained. Based on the information The correct dimensions are: 288 for DCPP; 384 for PVNGS 14th Paragraph (1st given in this paragraph. there are 6 magnitudes, 13 distances, 2 styles Model A; 192 for PVNGS Model B paragraph on page), Line of faulting, and 2 Ztor values; 6 x 13 x 2 x 2 = 312. Please clarify. 7 421. Section 6.4.3, page 6-14, This sentence seems redundant with the content of the previous Spelling corrected. Redundant text removed 15th paragraph of section paragraph, except that the cited dimension of 284 for PVNGS is (2"0 paragraph on page), inconsistent with the dimension of 384 in the bulleted list in the 1** sentence preceding paragraph and with the dimension cited in the subsequent sentences (also note that PVNGS is misspelled in both of its occurrences). Please clarify and correct. 422. Section 64.3. page 6-14, Please explain the reason for the extra step of first projecting the space Explanation provided 15'h paragraph of section using principal component analysis. (2"d paragraph on page), line4 423. Section 6.4.3. page 6-14, To avoid confusion, please consider rewriting to avoid the ambiguous Done 151h paragraph of section "2881384/192" notation (here, and elsewhere In the report). For example, (2"d paragraph on page), consider the alternative phrase '"each model corresponds to a point in N-2"' sentence dimensional space, where N has values of 288. 384, and 192 for the DCPP, PVNGS Model A, and PVNGA Model B cases, respectively." 424. Section 6.4.3, page 6-14, Please provide the basis or reference for the statement '"the first two No further explanation will be added in the text, because it has 15th paragraph of section principal components. however, typically account for about 85-90% of been already mentioned before that 1he methodology is well (2"d paragraph on page), the variance". described in the report (Attachment E for Rev.1; Introduction to 3'0 sentence Appendix H for Rev.2) 425. Section 6.4.3, page 6-14, This sentence appears to misrepresent what is presented above. Please Sentence and section has been rearranged. The logic of the 15th paragraph of section consider restructuring the sentence to begin "As described above, the discussions in now improved (2"" paragraph on page), contributions to the difference in the squared Euclidean distances .. ". 4*h sentence 426. Section 6.4.3. page 6-14, Please show the values of deaggregation weight for some example M-Plots included in text See also answers to 412 151h paragraph of section distance bins and periods. (2"d paragraph on page), last line 427. Section 6.4.3. page 6-14, Please check the definition of u.. Should the second entry in the set be 2 The correct value is 2; typo corrected 16th paragraph of section (not 0.2)? (3'd paragraph on page). first line after Eqn 6.4-6 428. Section 6.4.4, page 6-14, Please explain why an ellipse was chosen, in what sense the ellipse is The reason is that the x axes is the direction of the epistemic 1 paragraph of section, best fitting, and why the best fitting ellipse is always horizontally uncertainty scaling-explanation added here and also inserted in 2"c sentence oriented. Chaoter 8 429. Section 6.4.4. page 6-14, The correct expression here is "convex hull" (not "complex"). Please We added a plot showing the convex hull, corrected the 1"' paragraph of section, make that correction, define what it is, and consider whether the ellipse verbiage and provided explanation 2** sentence is fit to the boundary curve of the convex hull. 430. Section 6.4.4, page 6-14, The acronym "GMPE" is used indiscriminately in this chapter, Done throughout the report 1** paragraph of section, sometimes to mean specifically the original set of eight published 2"" sentence GMPEs, other times to refer to members of the ensemble of constructed virtual GMPEs. Please clarify the meaning of GMPE used here and be consistent in uniquely describing which definition of GMPE is meant when it is used elsewhere in the chapter. 431. Section 6.4.4, page 6-14, The expression uncertainty models" is used here without definition and Terms rewritten for clarity 1 paragraph of section, the resulting text is ambiguous and confusing. Please rewrite for clarity. 2"" sentence If the set of GMPEs formed from the original GMPEs with added epistemic uncertainty is going to be used repeatedly. please introduce an unambiguous terminology and use it consistently. 432. Section 64.4. page 6-t4, Since it has not been explained how the ellipse is going to be used, the Sentence rewritten to improve clarity 1" paragraph of section, significance of scaling it up is not clear at this point in the narrative. Nor 3'" sentence is the parenthetical comment comprehensible (e.g., capture the full range of what?). Please rewrite this discussion to clarify the reasoning behind centering and scaling the ellipses this way. including the reasoning behind the choice of the factors 1.5 and 0.5. 433. Section 6.4.4. page 6-14, 1 paragraph of section, This sentence is incomprehensible. Please rewrite it for clarity. Done last sentence 434. Section 6.4.4, page 6-15, Please state what data set(s) the residuals are calculated for. and clarify Clarifications added 2"c paragraph of section whether the between-event residuals are also weighted by (1" paragraph on page), deaggregation weight to emphasize the magnitudes that are more line 1 important for hazard and, if they are not weighted, please explain why. 435. Section 64.4. page 6-t5. Please provide additional discussion of the method for producing the Additional discussion provided 2"c paragraph of section ellipses and justify the 5 selected residual values used to define the (1 paragraph on page), intersection points between the residual contours and the ellipses. line 2 436. Section 64.4. page 6-t5. Please clarify the meaning of uncertainty models" (see earlier comment Verbiage replaced as "additional epistemic uncertainty" 2"' paragraph of section suggesting use of a consistent, unambiguous expression for those throughout most of the section (1" paragraph on page), 3'0 sentence models) 437. Section 64.4. page 6-t5. What is meant by the phrase broadened lo capture this range"? That is, We meant that we increased the multiplication factor of the 2"' paragraph of section please state which new contours are then selected in that case. ellipse. We added more info on the "broadening" approach (1" paragraph on page), 3'0 sentence 438. Section 6.4.4, page 6-15, Please explain what is meant by the ambiguous phrase "center of the Clarification added 2"c paragraph of section original GMPEs." If this refers to the centroid point in Sammon's map (1" paragraph on page), coordinates, please say so. line 6. 439. Section 6.4.4. page 6-15, Please give the final number of selected representative points. A table with the info has been added 2"' paragraph of section (1" paragraph on page), last line 440. Section 6.4.4, page 6-Please be specific about the quantity to which the term "range Done 15, 3*d paragraph of refers. Please also explain how the range in the location of points on section (2"d paragraph the Sammon's map relates to the range of this quantity. In addition. on page) please explain why the range of Sammon's map coordinates in Figure 6.4.3-2 is larger by more than an order of magnitude than the range of Sammon's map coordinates in Figure 6.4.4-1 and all the other Sammon*s map figures in the report. 441. Section 64.4. page 6-t5. This is the first time the expression "epistemic models" has been used See answer to comment 436 3'" paragraph of section Please clarify what is meant by this expression (in contrast to previous (2" paragraph on page), references simply to "models" or "GMPEs"). znc sentence 442. Section 6.4.4, page 6-15, Please be specific and quantitative about this procedure. For example, 3rd paragraph of section how are the rescaled ellipses defined in the case noted? (2" paragraph on page). 211* sentence 443. Section 64.4. page 6-15, Please be clear that reference is being made to the original GMPEs and We added the qualifiers throughout the report to the best of our 3'" paragraph of section to those GMPEs with the added epistemic uncertainty terms. ability. (2" paragraph on page), 3** sentence 444. Section 6.4.4, page 6-15, Please explain how the model screening was done and what models A figure was added to show example of models that were 3'" paragraph of section were removed during the screening process. removed. (2" paragraph on page), 4"' sentence 445. Section 6.4.4, page 6-15, Please explain the basis for the assumption that "The selected points They are representative of the hazard by definition, because 4th paragraph of section are assumed to be representative of their neighborhood in ground-they produce the same GM. The differences in the standard (3 paragraph on page), motion space". deviation are less than . 1 . Not sure the text has been changed Line 1 to say so. 446. Section 6.4.4, page 6-15, Please clarify whether the word "boundaries" means boundaries of the We stated what is the scale factor for 4th ellipse (it is 2) 4"' paragraph of section outer Voronoi polygons, and state the scale factor used to define the (3 paragraph on page), fourth ellipse. Line 3 447. Section 6.4.4, page 6-15, Please explain the reason for not simply using the selected point to 4th paragraph of section represent the models in a Voronoi cell. (J't paragraph on page), line4 448. Section 6.4.4, page 6-15, The meaning of the phrase "closeness in hazard space for each cell" is See response to 449. 4"' paragraph of section not clear. For example, closeness of what to what? Please consider (3'd paragraph on page), whether this sentence can be deleted and the word "therefore" deleted 4'" sentence from the following sentence 449. Section 6.4.4, page 6-15, Please explain in what sense the hazard curve for the selected model is We defined "closeness" and provided explanation on how it is 4th paragraph of section "closest" to the mean. computed (3" paragraph on page), 6'" sentence 450. Section 64.4. page 6-15, Please explain why selection of this "closest" point as a representative ol same as above 4'" paragraph of section the cell does not contradict the first sentence of the paragraph. which (3 paragraph on page), appears to say that the points on the ellipses "selected" in the previous 5th sentence paragraphs "are assumed to be representative of 1heir neighborhood." 451. Section 6.4.4. page 6-15, Please explain how to interpret the x-and y-axis scale of the Sammon's Explanation provided (in the attachment E for Rev1, and in the 4'" paragraph of section map, as was requested by many workshop participants during introduction to Appendix H for Rev.2). (3 paragraph on page), Workshops 2 and 3 and recommended by the PPRP in its comment last line letters on the workshops. 452. Section 64.4. page 6-15, The phrase "distribution of HW branches for the selected representative Done 5'h paragraph (4'h branches" is awkward. Please consider rewri1ing this phrase to improve paragraph on page), 1" its clarity. line 453. Section 6.4.4, page 6-15, Please explain why this distribu1ion of HW terms does no1 contradict the The two steps for the HW approach for DCPP are better 5th paragraph of section statement in Section 6.4.3 that "the central hanging wall branch is described in Section 6.4.3 (4'" paragraph on page). applied for the Sammon's maps." That section also notes that "later the 2"" sentence DCPP base models are assigned a random HW models[sic]," but there appears to be no mention of that addition in the intervening text. The treatment of the HW terms requires clarification. 454. Section 6.4.4, page 6-15, Please state the rationale for the assessment given in this sentence. Justification added as of why HW effects are not important for S"' paragraph of section PVNGS. (41" paragraph on page). last line 455. Section 6.4.5, page 6-15, Please explain the need to assign a weight to each selected model. Also Further text added to explain what the rationale for not assigning 1 paragraph of section, note that the sentence refers ambiguously to "representative models for equal weights is. Concept also addressed in Appendix 0 line 1 each cell." Please use the singular "model" to avoid the implication that there could be multiple models selected for a cell, unless that is the intent. 456. Section 6.4.5, page 6-15, Please indicate what data set(s) the statistics are calculated for, and The word "mean" has been dropped. Verbiage change has been 1" paragraph of section, clarify what is meant by "mean statistic" in this context (e.g., why is it applied to say "metric" throughout the section. Same verbiage 1 sentence appropriate to call the likelihood a mean statistic?). modification applied to chapters 8 and 9 for consistency 457. Section 64.5. page 6-t6, The same notation, "w", was used for the weights defining the Eqn 6.4-7 Sammon's distance metric. This is potentially confusing, especially since the term "weight" is used for both. Note also that "L is used in this equation to represent a generic statistic, but the same symbol is defined as the likelihood in the subsequent bulleted list Please make corrections to ensure that notation throughout the chapter is consistent and unambiguous. 458. Section 6.4.5, page 6-16, Please replace the typo "combing cell with "combined cell", or perhaps Done paragraph 1 on page, 2"d even better by "merged cell" to be consistent with the previous sentence. to last line 459. Section 6.4.5. Page 6-16. Please define "M" and D". Notation removed Second Paragraph on page, Last Bullet 460. Section 6 4.5 t, page 6-Please explain the basis for assuming that the cited properties of the The verbiage "Equal weights" refers to assignment of equal 17, 2"' paragraph of original GMPEs are also applicable to the constructed GMPEs. weights to the models used to generate the covariance matrix. section (1'1 paragraph on Once generated, the prior weights reflects how often page), line 6 generated ground motion models appear in a particular location. The prior weight incorporates the notion that the covariance is correct and represents the uncertainty fully. 461. 6.4.5.1, page 6-17. This sentence is imprecise about the definition of the norms referred to. Sentence deleted paragraph 2 of section as well as what space they are defined on. The sentence could be (1"1 paragraph on page), interpreted to suggest that the mean residual is an L 1 norm, which it is last sentence not, nor is it even a norm at all, nor is its absolute value (neither one is positive definite). The sentence should be rewritten to make it clear what norms it refers to, and what vector space the norms apply to. Alternatively, if the sentence is not essential to subsequent arguments, please consider deleting it 462. Section 6.4.6, General Please summarize the Tl Team's assessment of the appropriateness of The Tl Team's assessment is contained in Chapters 8 and 9. the selected models and model weights in capturing the center. body. and range of the median amplitude. If such assessments are discussed in Chapters 8 and 9, please provide references to the relevant section(s). 463. Section 6 4.6. General Please discuss the following observation: For M 7 5 and short periods An explanation has been added (PGA and T=0.2s), the ground-motion distribution at larger distance (Rx > 30 km) is broader than at shorter distances (Rx< 10 km); see, for example, Figure 2.178 of Appendix H. Please explain the cause of this behavior. Given that empirical data are sparser at shorter distances. intuitively. shouldn't the epistemic uncertainty be larger at shorter distances than at larger distances? 464. Section 6.4.6, General Please discuss the following observation: For PGA and T=0.2s, ground-An explanation has been added motion distributions at Rx=-1 and -5 exhibit a large negative skewness at M > 6 5: see for example, Fig. 2.236 of Appendix H. In contrast, the distribution based on the candidate GMPEs shows much less skewness Please explain the cause of the negative skewness and justify the appropriateness of the model distribution. Also. please discuss whether the negative skewness may yield more conservative (or less conservative) hazard in comparison to the use of a less skewed distribution (such as the one from the candidate GMPEs). 465. Section 6.4.6, page 6-17, Please correct the section reference. Done Line 1 466. Section 6.4.6, page 6-17, Please specify the section number in the statement "in the section for Done Line 5 PVNGS" 467. Section 6.4.6. 1, page 6-Please clarify what the "total weights" case represents, since it has not Done 17, 2"c paragraph in been defined at this point in the text. This expression is also used section, Lines 3 and 4 without definition in Chapter 8-please make necessary edits lo ensure claritv 468. Section 6.4.6.1, page 6-Please clarify whether reference is being made to the original empirical Done 17. 2"" paragraph in GMPEs or to the constructed virtual GMPEs. section, Lines 4 and 5 469. Section 6.4.6.1, page 6-Please justify the weights 80%110%110%, given that the plus/minus 17, 2"' paragraph in models are two limes the standard error away from the mean. section, Lines 5 470. Section 6.4.6. 1, page 6-The expression "plus/minus uncertainty model" is imprecise and Done throughout the report 17, 2"' paragraph in ambiguous. Please use a clear, unambiguous terminology for this set of section, Lines 6 and 7 models consistently throughout the chapter. 471. Section 6.4.6.1, page 6-The residual-based weighting case for the NGA dataset is indicated as We added the "usually" qualifier, and added few examples 18. 3rd paragraph of being the blue curve in Figure 6.4.6-1. That curve appears to define a rather than only one (from Appendix H). Typo corrected. section ( 1 '1 paragraph on relatively narrow distribution (probably the second narrowest after the page), 1"' 2 sentences likelihood case for the EU dataset), apparently narrower than that of the black curve representing the GMPEs. But the text here says the opposite ("using the residual-based weights yields to[sic) ground motion distribution broader than the one associated to the candidate GMPEs". Furthermore. the prior-based case (brown curve) appears to be one of the broadest. yet the text says . ._ .. prior-based weights lead[s) to narrow distributions." Please provide clarification as to what the conclusion actually is, and then further clarify whether the stated conclusion applies to the majority of scenarios examined in Appendix H (also note the typo, "yields to instead of "yields a"). 472. Section 6.4.6.1, page 6-The total weighted distribution of the simulated weighted GMPEs is very 18. 3'd paragraph of similar to the distribution for the GMPEs themselves. Please indicate if section ( 1 '1 paragraph on this is true in general and if the weights were chosen to closely match page), 3'" sentence the GMPE distribution on average. 473. Section 6.4.6.2, Page 6-Please clarify if the term "quantile" is the same as the term percentile" The terms are the same, but have not been unified in the report 18. 1st Paragraph of used elsewhere in the report and appendices and, if it is, please Section, 2nd Line consider consistently using only one of these terms in order to avoid confusion. 474. Section 6.4.6.2, page 6-The phrase "Widthlrange" is vague (e.g .. is there a distinction between The two terms have been separated. 18. 1st paragraph, last line width and range, and if so what is it?). Please use language that is precise about what specific attribute(s) will be compared. 475. Section 6.4.6.2, Page 6-Please explain the significance of the comparisons shown in Figures A sentence indicating that the distributions are similar has been 18. 2nd Paragraph of 6.4.6-2 through 6 4 6-4. It appears that the two distributions are added Section generally similar. 476. Section 6.4.6.3, Page 6-Please explain the significance of the quantile ratio plots shown in It is a way to summarize width of distribution. Clarifying text was 18. 2nd Paragraph of Figure 6.4.6-5. added. Section 477. Section 6.4.6.4, Page 6-Please reconcile the "broader distribution" shown in Figures 6 4 6-6 and Partially answered 19, 2nd Paragraph of 6.4.6-7 with the previous figures that show similar 0.05, 0.5, and 0.95 Section, 4th Sentence auantiles for the simulated models and the GMPEs. 478. Section 6 5. 1. General There is insufficient discussion of directivity models for the dip-slip The model applies to both strike slip and dip slip ruptures. earthquake sources. Please enhance the text to address this deficiency. Directivity has no hazard significance (As shown in Chapter 14). so we feel that the discussions are adeauate 479. Section 6.5.1, Page 6-19, Please replace "Somerville et al. (1999)" with "Somerville el al. (1997)". Done 1st Paragraph of Section, 2nd Line 480. Section 6 5.1. Page 6-19. There is no mention of magnitude in Figure 6.5.1-1, although it can be Done 3rd Paragraph of Section. presumed that the different rupture lengths shown in this figure 2nd Line represent different magnitudes. Please include the magnitude in addition to the rupture length in Figure 6. 5.1-1 for com ple1eness and lo tie the figure to the MS magnitude mentioned in this sentence. 481. Section 6 5. 1. Page 6-20. Please also reference Spudich and others (2014; Earthquake Spectra, Verbiage inserted into the main text. References polished 4*h Paragraph of section vol 3., no. 3, page 1199-1221) and Spudich and Chiou (2013; Chapter 5 (2"d on page), First of PEE R's directivity working group report). since both gave an in-depth Sentence discussion on the issue of centering. 482. Section 6 5. 1. Page 6-20. The NGA-West2 developers had originally concluded that the Chiou and Clarification provided 4'" Paragraph of section Youngs (2014) directivity model could not be used with other GMPEs (2"d on page), 2"" because of the centering issue. Please explain the basis or provide a sentence reference for assuming that the CY14 directivity model can now be used with other GMPEs. 483. Section 6 5.1. Page 6-20. Chiou and Youngs (2014) addressed the effect of directivity on only Explanation added 4'" Paragraph of section median amplitude. Please explain the basis for concluding that there is (2"d on page), line 6 variation of sigma along strike, and explain what sigma is referred being referred to. 484. Section 6 5.1. Page 6-20. Please explain the need for simplifying the application of the directivity We have to simplify to speed up the calculation so we do not 5"' Paragraph of section model. Also ensure that Watson-Lamprey (2014) (still listed as being in integrate over the hypocenter distribution in the hazard 3'" on page), Line 1 preparation) will be published (or at least be in press) prior to finalizing computations. The issue of the draft report timeline for the PSHA report if the results of the study are to be used by the Tl Team publication is out of our control, but we have included what was as part of their evaluation. used so the documentation is complete. We are using the draft report and the SSHAC guideline allows us to use unpublished results. This issue is further addressed in Rev.2 report. 485. Section 6.5.1, Page 6-20, Please provide a definition and a brief description of the variable "DPP." A reference is already provided. No further actions needed S"' Paragraph of section 3'd on page), Line 6 486. Section 6.5.1, Page 6-20, Please indicate if Attachment C passes peer review or the Tl Team's The Tl Team reviewed the resulting model and its applicability to 6"' Paragraph of section evaluation. Please describe the Tl Team's basis for accepting the DCPP conditions. The PEER report is in draft stage. but it was 4'" on page). Line 1 simplified models in Attachment C for use in the hazard calculation. not our job to edit the report for completeness 487. Section 6 5.1. Page 6-20. Please clarify who developed the parametric model, and indicate We used two different hypocenters along strike but only a single 7"' Paragraph of section whether rupture depth (which is not mentioned here) was considered as model for hypocenter depth. For the DCPP application, 5"' on page). 1** 2 a parameter and found to be insignificant. directivity effects due to rupture depth are not important. sentences Sensitivity analysis in Chapter 14 shows no significant sensitivity to the directivity. therefore we did not develop more models for depth distribution. No change in the text. This issue is further addressed in Rev.2 report. 488. Section 6.5.1, page 6-20, If the phrase " ... at the ends of the large strike-slip faults." is meant to Clarification added 8"' paragraph of section indicate "at the ends of large strike-slip ruptures, please make that (61" on page), 2"d to last correction. In any case, please clarify the meaning of the phrase line. 489. Section 6.5.1, page 6-20, To avoid potential misunderstanding, please revise the text to note that Done 8111 paragraph of section this statement refers to the case of treating the hypocenter position as (61" on page), line 5 random along the fault, not the case where the hypocenter is deterministically specified. 490. Section 6.5.2, Page 6-21, The first sentence is ambiguous (e.g., "a small impact" could be Done First Paragraph interpreted to mean a significant one), and the Workshop 3 reference is incorrect (Section 4 does not exist). In any case, please cite the Chapter 14 sensitivity studies here to provide an adequate technical justification for the simplified treatment of directivity. Once the Chapter 14 sensitivities are referenced, consider whether also citing the workshop proceedings is redundant. 491. Section 6.5.2, Page 6-21, Please provide a discussion of other directivity models published since First Paragraph, Last 2008, including why Chiou and Youngs was selected but not alternative Sentence models 492. Section 6 6.1. Page 6-21. In order to avoid confusion, please reserve the term "proponent models" Agree. Clarification and consistent nomenclature added. General and "proponent methods" to refer to models or methods proposed by Proponent Experts as defined in the SSHAC guidelines. Please use a different name to refer to models proposed by the Tl T earn here and elsewhere throughout the report and appendices. 493. Section 6.6.1, Page 6-21, Please define what is meant by "path terms" the first time it is used, so Done 2nd Paragraph of the reader need not have to read Appendix L to understand what the Section, 1st Line term means. 494. Section 6.6.1, Page 6-21, Please provide a reference to the specific report sections, tables and/or Done 3rd Paragraph, Line 3 figures where the description is provided. 495. Section 6.6.2, Page 6-2t. Please clarify what the units (and sign) of the path term mean, and The units are log ground motions. A possible explanation is that First Paragraph, Line 1 explain whether the large negative path term (about -0.5) for regions 2 those ray paths travel a zone with higher heat flow. and 3 appears reasonable on geological and geophysical grounds, such as known differences in crustal structure. Also. please comment on the size of the path term compared to those estimated for other regions by previous studies. 496. Section 6.6.2, Page 6-21, Please comment as to whether additional epistemic uncertainty in the The uncertainty reflects the sample size and we also have First Paragraph, Line 1 path term is warranted, given that a sparse dataset was used in its considered the additional uncertainty related to the large M estimation. scaling 497. Section 6. 7.1, Page 6-22, Please define what is meant by "R here. Definition added First Paragraph, Line 5 498. Section 6 7. t. Page 6-22. The term "PSA" is used on line 7, and "Sa" is used in Eq. (6.7-1 ). Please Consistent term is used throughout the report First Paragraph, Line 7 select and use a consistent term for this parameter. and Eqn 6.7-1 499. Section 6. 7.1, Page 6-22, Please provide a short description of the motivation behind Method 1. Done First Paragraph, Line 10 500. Section 6. 7.1, Page 6-22, Please consider revising the phrase '"single representative rupture" so Clarification added First Paragraph, Last that it will not be misconstrued as a new rupture geometry modified from Sentence the rupture geometry specified in the SSC model. For example, doesn't the method create a single representative set of predictor variables? 501. Section 6.7.1, Page 6-22, Please define the term 'WidthDD" here and include it in the list of terms. substituted with "Down-dip width" Second Paragraph, First Sentence 502. Section 6 7. 1. Page 6-22. Please check whether the second sentence is redundant-given that it Done Second Paragraph appears to just repeat the content of the first sentence-and revise if appropriate. 503. Section 6 7.1. Page 6-23. Please define the distance metric "R", and consider changing the phrase Done 3'" Paragraph of section "based on distance" to something like '"based on inverse-squared (2"" paragraph on page), distance". Line 3 504. Section 6.7.2, General There are empirical ground-motion data from historical earthquakes that Reference to Somerville et al (2011) presentation added to the exhibited complex rupture or splay fault rupture, including those in the text. NGA-West2 database and the 2011 Fukushima-Hamadori, Japan. earthquake. Please indicate whether these empirical data were used by the Tl Team to evaluate the four proponent methods. If so, please describe the main results of the evaluations; if not, please explain why not. 505. Section 6.7.2.1, Page 6-Please explain what is meant by the term '"main rupture'" or rewrite the We use the term "primary" and '"secondary rupture 23, 1st Paragraph of section in a form that does not depend upon making that distinction. Section, Last Line 506. Section 6. 7.2.1, page 6-Please rewrite this sentence to improve its syntax and clarity. Done 23. paragraph 3 of section, t" sentence 507. Section 6 7.2. t, Page 6-Please brieffy summarize the discussion from Appendix J explaining the We analyze only representative cases, not covering the full 23. Second Paragraph. extent to which these complex scenarios cover the full range present in range of scenarios in the SSC model Line 2 the SSC model. Also please provide specific (subsection number) reference(s) to that discussion to justify the sufficiency of these scenarios. Also, Figure 6.7.2-1 does not provide a clear annotation of the associated geometry for the main rupture. the combined rupture, and the location of the site mentioned on Line 2. Please revise the text and the figure to correct these deficiencies. 508. Section 6.7.2.1, page 6-Please explain more clearly and precisely what the term Done 23, 3*d paragraph of "complex/simple LN (ratios) means. Also, please use conventional section, lines 3-5 notation such as ln(x) for the natural log of x (here and elsewhere in the report). 509. Section 6.7.2.2, Page 6-Please brieffy summarize the discussion from Appendix J explaining that see answer to 507 24, Second Paragraph these splay scenarios cover the full range present in the SSC model. Also please provide specific (subsection number) reference(s) to that discussion to justify the sufficiency of these scenarios. 510. Section 6.7.2.2, page 6-Please rewrite this sentence to clarify its meaning. sentence rewritten 24. paragraph 3 of section, 1*1 sentence 511. Section 6.7.2.2, page 6-The text states that "The site is assumed to be located near the splay Parenthetical comment removed 24. 2"" paragraph of rupture (otherwise the effect of the splay can be ignored)." If in the upper section, last line right diagram of Figure 6.7.2-1 the site were moved from "near the splay" to near the part of the main fault southeast of the junction. what would be different? Please explain the origin of the asymmetry; that is, please explain why the splay can be ignored if the site is near the main fault (the part of the main fault that is SE of the junction, just like the splay is), but the SE part of the main fault cannot be ignored if the site is near the splay. Alternatively, consider deleting the parenthetical comment if it is irrelevant to the ground motion model 512. Section 6 8. Page 6-25, Please provide a more complete description of the Abrahamson (2000) Done 4th Reference reference (e.g., dates and location of the conference, paper number, proceedings pages, etc.) 513. Section 6 8. Page 6-25, Please update the Abrahamson et al. (2014) reference with page Reference fixed 6th Reference numbers from the published manuscript. 514. Section 6.8. Page 6-25, Please replace the date "2013" with "2014a" in the Akkar et al. (2013) Reference fixed 7th Reference reference to renect the actual date of publication. Note that the "a" should be added because the referenced erratum was published in the same year. 515. Section 6.8, Page 6-25, Please update the Akkar et al. (2014) reference with the volume and Reference fixed 8th Reference page numbers of the published manuscript. Please also replace the date "2014" with "2014b" to renect the fact that the original manuscript was published in the same year as the erratum. 516. Section 6.8, Page 6-25, Please update the Al Atik and Youngs (2014) reference to include the Reference fixed 9th Reference page numbers of the published manuscript. 517. Section 6 8. Page 6-25, Please replace the date "2013" with "2014a" in the Bindi et al (2013) Reference fixed 11th Reference reference to renect the date the manuscript was published and the fact that the erratum was published in the same year. 518. Section 6.8, Page 6-25, Please replace the date "2014" with "2014a in the Bindi et al. (2014) Reference fixed 12th Reference reference to renect the fact that the original manuscript was published in the same year. 519. Section 6.8, Page 6-25, Please update the reference Bommer et al. (2014) to include volume Reference fixed (it is now Atkinson et al. 2014) 13th Reference and page numbers of the published manuscript, if available. 520. Section 6.8, Page 6-25, Please update the Boore et al. (2014) reference to include the page Reference fixed 15th Reference numbers of the published manuscript. 521. Section 6.8. Page 6-26, Please update the Campbell and Bozorgnia (2014) reference to include Reference fixed 1st Reference the page numbers of the published manuscript 522. Section 6 8. Page 6-26, Please provide the organization that the Chiou et al. (2000) report was 2nd Reference submitted to 523. Section 6 8. Page 6-26, Please update the Chiou and Youngs (2014) reference to include the Reference fixed 4th Reference page numbers of the published manuscript. 524. Section 6.8, Page 6-26, The Graizer (2014) reference is not cited in the text. Please either cite The model is referred in various occasions. Proper reference 7th Reference this reference or remove it from the list of references. inserted 525. Section 6 8. Page 6-26, The Graves and Pitarka (2014) reference is not cited in the text, but is References to the FFS methods GP. SDSU and EXSIM are 8th Reference probably the reference to the acronym "G&P (also cited as "GP") used provided. to identify one of the simulation methods in some of the figure captions. Please cite this reference the first time that the acronym "G&P" is used and use a consistent acronym for this reference. 526. Section 6.8, Page 6-26, Please update the Idriss (2014) reference to include the page numbers Reference fixed 9th Reference of the published manuscript. 527. Section 6 8. Page 6-26, Please replace the date "2014a" with "2014" in the Kashida et al (2014) Reference fixed 12th Reference reference. 528. Section 6.8, Page 6-26, The Olsen and Takedatsu (2014) reference is not cited in the text. but is See answer to 525 14th Reference probably the reference to the acronym "SDSU" used to identify one of the simulation methods in some of the figure captions. Please cite this reference the first time the acronym "SDSU" is used. 529. Section 6 8. Page 6-26, Please provide a more complete description of the Somerville and Done to the best of ability 17th Reference Abrahamson (1995) reference (i.e .. report number, organization, etc.). 530. Section 6.8, Page 6-27, Please update the Watson-Lamprey (2014) reference with the report The draft PEER report is associated to the 2015 date (and not 2nd Reference number, publisher, etc .* if available. If the report is not published or in 2014 as correctly noted by the PPRP). press al the lime the SWUS report is finalized, any reference to the We disagree that the PEER report should be considered a Tl PEER report should be removed from the report and characterized as Team's product. but the Tl Team's evaluation of the candidate an analysis performed for the Tl Team and included as an appendix. directivity model is part of the SWUS report. 531. Table 6.6-t, Page 6-29 The values given in Table 6. 6-1 do not appear to be consistent with the The table is correct: Regions 2 and 3 are combined in the table proposed models shown in Figure 6.6.1-2. Please explain why this is the case, or if in error. correct the table or figure. 532. Table 6 7-1. Page 6-30 Please define the term "DDWidth" the first time it is used Changed to Down-dip Width 533. Figure 6.2.1-1, page 6-31 In the explanation, the acronym "ld14" is used, whereas in the text, ii is Abbreviations are now consistent given as "114". Please choose one and be consistent. This same comment applies to the corresponding figures. 534. Figure 6.2.1-2, Page 6-32 Please explain what the term "ZH06 = ZL 11" means in the legend and Explanation on ZH06 = ZL 11 is provided in caption. correct "ZH06" to "Z06 and "ASB 13 to "ASB 14" to be consistent with Abbreviations are consistent. the terminology used in the text. 535. Figure 6.2.3-1, page 6-34 The caption refers to periods al 0.2, 0.5, 1.0 and 2.0 seconds, but is not Period labels added. Consistent abbreviation provided. clear as to which panel is which. Please label the individual panels for clarity. Please also remove mention of a specific period in the legend, since period varies from panel lo panel. Also correct the legend to refer to the NGA-West2 models by the acronyms used in the text (e.g., "ASK14"). 536. Figure 6.2.3-2, Page 6-Please explain the meaning of the phrase "over frequency" in the figure 35, and Figure 6.2.3-3, caption. Page 6-36 537. Figure 6.3.1-2, page 6-38 The solid (5 km) and dashed (10 km) curves should be belier explained Consistent abbreviation provided. in the caption. Also, please refer to the GMPEs in the legend by the acronyms used in the text (i e., "ASK14" instead of "ASK") 538. Figure 6.3.3-1, page 6-39 Please add an explanation of the black curves to the caption. Please Done also define the terms EXSIM, G&P. and SDSU and provide citations to references in the list of references. The apparent references to these models in the list of references are incomplete and should be updated to "in press or published when possible. Please note that the reference to EXSIM is missing from the list of references. 539. Figure 6.4.3-1, page 6-40 Please provide in the caption the predictor variable values for which the See answer to 393. Labels and scenario clarified. Description of plot was generated. Also please consider explaining more explicitly that red curves enhanced. the red curves represent the distribution of the median (mean of natural log) for each GMPE based on the Al-Atik and Youngs (2014) analysis of epistemic uncertainty. 540. Figure 6.4.3-2, page 6-40 Please explain in the caption how to distinguish the Model A and Model Done. B samples, and also give the meaning of the solid dots and their colors. Please also define the axis labels. The plot of "sampled models" is for 15,000 samples, but 2,000 samples were used. Please replace this plot with one for 2,000 samples to better represent what was used in the evaluation. 541. Figure 6.4.4-1, page 6-41 Please correct the caption to read "mean between-event residuals," add Done an explanation of the black dots, and identify the "contours" as the gray lines in the plot. 542. Figures 6.4.6-2, 3 and 4, Please add explanatory text to the caption indicating that the solid lines Done pages 6-43, 6-44, and 6-are the 0.5 quantiles, whereas the dashed lines represent the 0.05 and 45 0.95 quantiles 543. Figures 6.4.6-2, 3, 4 and Please explain the meaning of the term "total weights" in the figure Done 5, pages 6-43, 6-44, and caption. 6-45 544. Figure 6.5.1-5, Page 6-47 Please replace the date "1999" with "1997" in the Somerville el al. Done (t999) reference in the figure caption. 545. Figure 6.6.1-1, page 6-49 Please correct the mislabeling of the figure in its caption. Also, in the Done caption, please specify which colors are referred to for the "colored lines" that represent faults, as there are also colored lines that separate regions. Also please add the location of PVNGS to the map. Note also that 5 earthquakes appear to be located in Region 1. whereas the text seems to indicate that there are 3 (first line on Page 6-22). Please review and revise this caption as needed 546. Figure 6.6.1-2, page 6-50 Please correct the mislabeling of the figure in its caption, and provide Done the units for the oath terms aiven in the olots. 547. Figure 6.7.2-2, page 6-52 Please label the vertical axis. The simulation model acronyms in the GP is used throughout the report. The figures with axis label are figure caption have not been defined in the text at this point. Please available in Appendix J and are provided in Chapter 6 in a make sure they are defined and cited prior to being used the first time consistent manner. and that they are included in the list of references. Nole also that the acronym "GP" is referred to as "G&P" elsewhere in the chapter. Please use a consistent acronym for "G&P" throughout the report and appendices. 548. Figure 6.7.2-2,3,4, pages Captions for these figures are inadequate. Please write captions that Done 6-52, 6-53, and 6-54 indicate the scenarios for which results are depicted and, in the case of Figure 6.7.2-3, indicate what the respective colors represent. Also label and provide units for they axis in Figure 6.7.2-4, and check that all references to the simulation models use acronyms that have previously been defined and are consistent with usage in the rest of the report. CHAPTER 8 Median GMC Models: DCPP Sources 549. Section 8.1, page 8-1, Please consider writing a more precise statement of the procedure. Clarification added numbered item 4 For example, would ii be better described as sampling from the multivariate normal distribution defined by the coefficient covariance matrix? 550. Section 8.1, page 8-1, This statement is impossible to parse. Please consider rewriting to Paragraph rewritten to improve clarity item 5 improve its clarity. One option to consider is breaking it into 3 items, the first stating the formation of high-dimensional vectors. each representing the ground motion predictions of a given model for a representative range of predictor variables, the second stating that a metric is defined on that high-dimensional space based on the differences in hazard level between model pairs. and the third staling that the vectors are represented in two dimensions via a (nearly) metric-preserving mapping procedure by means of a Sarnrnon's map. If the term "deaggregation" is retained in the revision of this passage, please indicate what it means in this context (i.e .. what was deaggregated and for what set of parameters). 551. Section 8.1, page 8-1, Please specify that it is the two-dimensional space (i.e., after the Done item6 Sammon's mapping procedure is applied) that is discretized. 552. Section 8.2, page 8-1, The statement that weights associated with statistical sampling are Done 1" paragrafh of shown in green seems a little odd, since none of the weights in the section, 2° sentence figure are actually shown in green (and in fact there are no green weights in any of the figures in the entire chapter). Please consider revising this and other related statements to avoid confusion. 553. Section 8.2, page 8-1, Weights of the base models are not provided on Figure 8.2-1. Done 1** paragraph of Please provide the missing weights and indicate the nature of these section, 2"d sentence weights (i.e. are they subjective weights or weights associated with statistical sampling). 554. Section 8.2, Page 8-The definition of "base model is given after it is first mentioned on Done 1, Second Paragraph Line 1 of Page 8-1 . Please move this definition to where it was first of section. Line 2 mentioned. 555. Section 8.2, Page 8-2, 4m line on page Please explain how a HW model was assigned to each base model. Done 556. Section 8.2, Page 8-Please clarify if the hazard for spectral periods longer than 3 sec are Clarification added 2, 3'd of part of the deliverable and, if yes, please provide a reference to the section (2" on page). sections where median models for these long period spectra are Line 2 evaluated and integrated into logic trees. 557. Section 8.2, Page 8-Please summarize the meaning of the different branches in the logic Done. Also. we changed colors to branches (all red entries) 2, 3"' of tree in Figure 8.2-2, similarly lo what was done for Figure 8.2-1. section (2° on page). 2nd Sentence 558. Section 8.2, Page 8-The discussion in Section 8.3 suggests that the Tl Team's focus is Clarification added 2, 3'0 Paragraph of on capturing the CBR of median-amplitude predictions. Please section (2" on page). provide text to clarify that "median ground motion models" is a Last Sentence shorthand for "median amplitude predicted by alternative GMPEs." 559. Section 8.3, Page 8-Please clarify whether the comment on the Rjb-based formulation is The problem is for both the GMPEs and the common-form 2, First Paragraph of directed toward the GMPEs (such as BSSA14) or toward the choice models section, Line 4 of the distance metric used in the common-form models. 560. Section 8.3, Page 8-Please specify the (lower) bound of the HW effect and how "being 2, First Paragraph of log-normally distributed" is unable to satisfy such a bound section, Line 6 561. Section 8.3, Page 8-Please refer to the specific branch in the Figure 8.2-1 logic tree Done 2, 1st Paragraph of Section, 4'" Sentence when describing weights. 562. Section 8.41, Page Please revise the text to be specific about the quantity to which the Done 8-2, 1 *1 Paragraph of term "range" refers. For example, is it the median amplitude section, First Line predicted by the GMPEs or the GMPEs themselves? 563. Section 8.4.1, Page The terms "common-form models" and "candidate GMPEs" are Consistent terminology applied throughout the report 8-2, 1st Paragraph of referred to by different names throughout the report and appendices. Section, 1st Sentence Please define a common set of terms for these models and use them consistently throughout the report and appendices and include them in the list of terms. 564. Section 8.4 1, Page The statistical uncertainty analyzed and parametrized by Al-Atik and Justification and discussion added 8-2, 1 Paragraph of Youngs (2014) was for the NGA-West2 GMPEs and associated section, Lines 4 and 5 datasets. Please comment on whether their results were also applied to non-NGA-West2 GMPEs and, if so, please justify that decision, given that a non-NGA GMPE may use a dataset different from those used by NGA-West2 GMPEs. 565. Section 8.4.1, Page Please revise the text to make it clear that the **+-2 sigma range" is Done 8-3, 2"d Paragraph of relative to the original candidate GMPEs. section (1'1 on page), Line 2 566. Section 8.4.1, Page Please reference the relevant sections of the report and/or Done 8-3, 2"0 Paragraph of appendices where the process of reducing the range in the common-section (t'1 on page). form models is reduced based on comparison with ground-motion 2"c sentence data. 567. Section 8.4 1, page 8-Please consider rewording this paragraph to indicate that the check Done 3, 2"" paragraph of is done to determine whether the resulting reduced range (not the section (1'1 on page), method) is appropriately wide. last sentence 568. Section 8.4 1, Page Please explain the phrase "weighted standard deviation between Clarifications provided 8-3, 4'" Paragraph of ground motions predicted by two different models ... **, and explain section (3" on page), (or provide a reference for) how it can be approximated by the Third Line distance between two points on a Sammon's map. 569. Section 8.41, Page Please indicate what the term "deaggregation means in this context A plot with the weights has been added to Chapter 6 8-3, 4'" Paragraph of (i.e .* what was deaggregated and for what set of parameters). section (3'* on page), 5'" line 570. Section 8.4.1, Page It appears that only seven red dots are plotted on Figures 8.4-1 and The plots are correct. we realize it is hard to see the dots but 8-3, S'" Paragraph of Figure 8.4-2. Please check and correct the text or figures as needed. they are there. section (41" on page), Line 2 571. Section 8.4.1, Page Please consider adding, parenthetically, a brief description of the Done 8-3, 61" Paragraph of NGAW2oc: database. section (51" on page). 4'h line 572. Section 8.4. 1, Page In setting the regions from which GMPEs are selected based on the Clarification added 8-3, 61" Paragraph of mean residual, please comment if the use of a horizon1al ellipse is section (5'" on page). compatible to the roughly 45-degree inclined pattern of the mean Last Sentence residuals. 573. Section 8.4.1, Page For the upper left plot, please label the contours of 1, 0.3, 0, -0.3, The contours for these values are now clearly marked 8-3, 61" Paragraph of and-1. (Rev.2) section (51" on page). Last Sentence. Figures 8.4-1 and 8.4-? 574. Section 8.4. 1, Page Please comment on the causes of the numerous small patches Done 8-3, 61" Paragraph of inside the horizontal ellipse. section (51" on page). Last Sentence. Figures 8.4-1 and 8.4-2 575. Section 8.4. 1, Page Please explain what "likelihood" is shown in the figures (i.e., the Clarification added 8-4, 91" Paragraph of likelihood with respect to what). section (2"" on page), 1" line 576. Section 8.4.1, Page Please explain why a fixed sigma value of 0.65 was used and what Clarification added 8-4, g1" Paragraph of impact it has on the results. Please also indicate whether "sigma" in section (2"" on page). this case is the between-event. within-event, or total standard 211* line deviation. 577. Section 8.4.1, Page Please explain the significance of a relatively low versus a relative Discussions provided 8-4, gt* Paragraph of high likelihood. section (2"" on page). 4'h line 578. Section 8.4.1, Page Please add additional contour levels to Figures 8.4-1 and 8.4-2 to Not possible at this time 8-4, 91" Paragraph of help show the likelihood value of each GMPE. section (2°d on page). Line 5 579. Section 8.41, Page In this section. the utility of using both the mean residual and the Clarifying text was added 8-4, 111"' (last) likelihood in setting the ranges was discussed. Please give a clear Paragraph of section and explicit summary of the roles played by each one in setting the final range. The boundaries shown in Figures 8.4-1 and 8.4-2 seem to suggest an unimportant role of the likelihood. 580. Section 8.4 1, Page There seems to be a large overlap in information and discussions Paragraphs consolidated 8-4, 11 u. (last) between this paragraph and the sixth paragraph on Page 8-3 (7'" Paragraph of section paragraph of Section 8.4.1 ). Please consolidate these two paragraphs where appropriate. 581. Section 8.4. 1, page 8-Please replace "epistemic" with "epistemic uncertainties. Please Done 4, 11th (last) also indicate the number of standard deviations used to represent paragraph of section, those uncertainties in the cited figure. line 3 582. Section 8.4. 1, page 8-Please explain why an extrapolation of the candidate GMPEs is Done 4, 11th (last) found in some cases and not in others. paragraph of section, last sentence 583. Section 8.4.2, Page Please be more specific about the parameter that is being referred Done 8-4, First Paragraph to of section, Line 2 584. Section 8.4.2, Page Please give a reference to where a summary of the datasets used in Done 8-4, 2"d Paragraph of this section is provided. section, Line 2 585. Section 8.4.2, Page Please provide a figure similar to Figure 8.4-4 for the simulated Done 8-5, 2"d paragraph of ground-motion data. section (1" on page), 1** line on page 586. Section 8.4.2, Page Please provide references to the sections where such definitions are Done 8-5, 3'd Paragraph of given. section (2"" on page). Lines 1and2 587. Section 8.4.2, Page Please provide the technical basis for the Tl Team's selection of the Done 8-5, 3'd Paragraph of (60, 40) mixing between the residual-based and likelihood-based section (2"d on page), weights. Line 4 588. Section 8.4.2, Page Please explain how the "judgments by the GMPE developers" are Done 8-5, 5'" Paragraph of transmitted and maintained by the selected GMPEs. section (41" on page), Item 3, Line 1 589. Section 8.4.2, Page The concern of non-independent model development has been Done both here and in Chapter 9 8-5, 61" Paragraph of brought up numerous times in this report. In this section, it is used as section (5'" on page), a critical factor in the Tl Team's evaluation of weights assigned to 1" sentence GMPEs. It is thus both helpful and important to have a clear discussion of this concern. including its causes, the magnitude-distance ranges where it is a prevalent issue, and an assessment of the extent of the resulting "redundancy." Please provide such a discussion, either here or in Chapter 6. 590. Section 8.4.2, Page Please indicate what actual weights the decision of a "3 to 1 Done 8-5, last paragraph on preference leads to for the empirical and the simulated data sets. page, last sentence 59t. Section 8.4.2, page 8-Please replace "cumulative density function" with "cumulative Done 6, (last) paragraph distribution function." in section, line 2 592. Section 8.4.2, Page Please clarify the meaning of "range" as used in this sentence. The Done 8-6, 7'" (last) likelihood approach seems to render a narrower "shape" (body) than Paragraph in section, other approaches but its range (the difference between the largest Line 5 and the smallest value) is comparable to others. Please be precise when the concept of the center and body of a distribution is invoked. 593. Section 8.4.2, Page Please provide the criteria against which reasonableness is Done 8-6, 7'" (last) assessed. Paragraph in section, Line 7 594. Section 8.4.2, Page Please clarify whether this is generally the case for different Done 8-6, 7'" (last) scenarios and spectral periods. paragraph in section, 2"" to last Sentence 595. Section 8.4.3, page 8-Please clarify that the CDF associated with the selected weights (not Done 6, 1"' paragraph of the weights themselves) has the property indicated Also indicate section, line 4 that "median" refers to CDF=0.5 on Figures 8.4-5 and 8.4-6. 596. Section 8.4 3, page 8-Please check the values given here for the offset of the medians in Done 6, 1" paragraph of Figure 8.4-5. For example, are the red (selected weights) and brown section, lines 4 & 5 (GMPEs) 50'h percentile values offset by about 0.1 natural log units (rather than 0 05 as stated), and is the purple (simulations) curve offset from the red by at least 0.15 log units (not 0.1 as stated)? 597. Section 8.4.3, Page Please clarify what is meant by the phrase "slope of the CDF" and Done 8-6, 1 "1 Paragraph of how this slope defines the body of the distribution. section, Last Sentence 598. Section 8.4.3, Page Please explain why curves representing the statistical uncertainties Reply to first part: Hazard curves for candidate GMPES with 8-6, 3'" Paragraph of of each original GMPE are not included in these plots (whereas they additional epistemic uncertainty are added to separate plot. section, Line 2 are included in previous figures for evaluation of the CBR of the ground motion distribution), and explain the odd shape of the 0.05 quantile curve for M7.5 in Figure 8.4-7. 599. Section 8.4.3, Page Please explain why the 50% value does not always track the median Explanation added 8-6, 3'° Paragraph of of the predictions of the original GMPE (e.g .. see the upper right plot section, Line 2 in Figure 8.4-9). 600. Section 8.4.3, page 8-In Figure 8.4-7, it appears that the selected models do not quite Explanation added 6, 3'" paragraph of envelope the original GMPEs for M 7.5 (e.g., at distance Rx<2), as section, 3'" sentence categorically claimed in the text. In fact, the figure gives the impression that M 7.5 is at least as much as exception (to the models enveloping the GMPEs) as is M 5.5, and the text does note the latter exception. Irrespective of whether the exceptions are significant, the apparent inconsistency between the text and the figure is confusing. Please clarify. 60t. Section 8.4.3, page 8-Although the reason for the selected M5.5 models not enveloping Explanation added 6, 3r<1 paragraph of the original GMPEs is given, please also explain why it is acceptable section, 4'" sentence to allow this underestimate of the range in GMPEs in the model. 602. Section 8.4 3, page 8-Please state the rationale for the Tl Team judgment cited here. Done 6, 3'" parawaph of section, 2" to last line on page 603. Section 8.4.3, Page Curves from the models with additional epistemic uncertainty are not The curves are included 8-7, 3'" Paragraph of shown in Figure 8.4-10. Please correct this oversight. section (1" on page), Line 1 604. Section 8.4.3, page 8-The phrase "all of the models are not enveloped" reads as if none of Sentence rewritten 7, 3'" of the models are enveloped. Please rephrase to state" ... not all of the section (1' on page), models are enveloped due to the sharp ... " last 2 lines 605. Section 8.4 3, page 8-Please indicate what "lower and "higher" center for the simulations Clarification added 7, 6"' of is with respect to (e.g., the GMPEs, the Tl Team's weighted average section (4' on page). model, etc), and whether it refers to ground-motion amplitude or 3*d sentence probability. 606. Section 8.4.3, page 8-Please explain the meaning of "the upper tail of the distribution in Clarification added 7, 6'" parawaph of section (41' on page). this context, and consider whether it is appropriate terminology to refer to the "center and body" of the upper tail distribution, or whether last sentence this may be an oxymoron. In any case, please define clearly what is meant in this context. 607. Section 8.4 3, Page Please improve the text so it is clear and easier to understand. The Done 8-7, ?'to Paragraph of revision should also indicate that CDF=0.5 refers to the median of section (5'" on page). the distribution and state what specific "statistics" are computed. Lines 1 to 5: 608. Section 8.4.3, Page Please explain what the "zero residual" is with respect to. Done 8-7, 7'" Paragraph of section (51" on page). Line 8 609. Section 8.4.3, page 8-Please note that the phrase "distance scaling" is repeated. Duplicate verbiage removed 8, of section (1' on page), line 2 610. Section 8.4.3, Page Please clarify which curve in Figure 8 4-17 corresponds to the mean Clarification was added in the caption, following the example 8-8, 11 paragraph of hazard. Also, please revise the categorical statement "larger than the in Figure 8.4-18 section (41" on page). hazard from GMPEs" (which appears to be true atlow probability but Second Sentence not necessarily at high probability). 611. Section 8.4.3, Page The original GMPEs with statistical uncertainties are an essential See reply to 598 8-8, 11 tt. paragraph of part of the overall epistemic uncertainty in the median motion, and section (41" on page). they are used extensively by the Tl Team in Section 8.4 to set the Third Sentence ranges from which representative GMPEs are selected. Given this, please justify why the hazard based on these GMPEs is not included in the checking exercise. 612. Section 8.4 3, Page The average hazard from the GMPEs is not shown in Figure 8.4-17. We disagree with this request 8-8, 11 *** paragraph of Please revise this statement to refer to "hazard" instead of "mean section (4'" on page), hazard". 5'" line 613. Section 8.4 3, page 8-Here the acronym "ID14" is used. whereas in Chapter 6, it was "114". Consistent acronyms are used. Clarification added 8, 11'" paragraph of In many of the figures, it is denoted "ld14." Please choose one section (4'" on page). acronym and be consistent throughout the text and figures. Also note line 7 that there is no separate GMPE for ZL 11 (it represents a method for characterizing magnitude saturation). Please describe how ZL 11 was used to create a GMPE where the empirical GMPEs are first discussed and assign it a unique acronym to use here and elsewhere throughout the report and appendices. 614. Section 8.5, page 8-9, This section seems to imply that HW effects are not involved in the See reply to 598 general model generation and representative model selection of Chapter 6. It is not clear how this is consistent with the second to last paragraph of Section 6.4.4. where HW effects appear to have been assigned by some form of sampling during the selection of representative models. Please clarify. 615. Section 8.5, Page 8-Please explain what the term "HW3" means. Explanation of terms and process to assign HW branch has 9, First Paragraph, been expanded Second Line 616. Section 8.5, Page 8-Please review the suitability of using the word "range" in the context Explanation added 9, First Paragraph. of this sentence. Please also indicate whether the center and body is Last Sentence also captured. 617. Section 8.6, Page 8-The workshop summary (near the bottom of Page G-17) suggests More exhaustive documentation and evaluation of directivity 9, First Paragraph. that directivity has a significant effect on hazard. opposite to what is models is added in Chapter 6 First sentence stated in this sentence. Furthermore. there is insufficient technical material in the workshop summary to allow for a review by the PPRP. Instead of citing the workshop summary. please provide a complete documentation of the hazard sensitivity analysis that supports the conclusion given in this sentence. or provide a reference to the section of the report that does so 618. Section 8.6, Page 8-Please explain how directivity effects were taken into account or Clarification added 9, 1st Paragraph of provide a specific (chapter, subsection) reference for that Section, Last explanation. Sentence 619. Section 8.7, Page 8-There is insufficient technical material in the workshop summary to More hazard sensitivities were not run for paucity of time, 10. First Paragraph, allow for a review by the PPRP. Please provide a complete but we expect the effect not to be significant given the low Last Sentence documentation of the hazard sensitivity analysis that supports the probability of occurrence. conclusion given in this sentence or provide a reference to the section of the report that does so. 620. Section 8.8, page 8-Please see previous comments regarding the list of references for Done 10 other chapters and appendices for guidance on revising the list of references in this chapter. 621. Table 8.4-1, page 8-Please indicate in the caption what is meant by the term SOF." Done 11 622. Figure 8.2-2, Page 8-Please indicate in the caption the meaning of the various branches Done 13, caption (e.g., what is meant by the terms "SIM", "NGAW2DC-MED" etc.). 623. Figure 8.4.1, Page 8-Please define the units for the color bar and explain the "In" in the Consistent labels and units are provided for plots in 14 and Figure 8.4.2, axis labels. Also please explain why these two plots label the axes Chapters 6, 8 and 9. Page 15 "In units" whereas what seem to be corresponding plots in Chapter 9 (Figures 9.1-2a,b and 9.1-3a,b) have their axes labeled "C1" and "C2". If there is no reason for a distinction. please make changes so lh"'f lhPV " 624. Figure 8.4-3, page 8-Please indicate in the caption andlor legend the number of standard Done 16 deviations that have been used to represent the uncertainties 625. Figures 8 4-5. 8.4-6, In the captions of these figures, "cumulative density function" is Done page 8-18; and & 8.4-incorrect terminology. Please replace by "cumulative distribution 11, page 8-23 function." 626. Figure 8.4-7, page 8-Please explain the meaning of the term "total weights in the figure Done 19 caption of this and other similar figure captions. 627. Figure 8.4-12, 8.4-13, Please make the titles on the figure subplots legible. Done page 8-24; and 8.4-14. page 8-25 CHAPTER 9 Median GMC Models: PVNGS Sources 628. Sections 9.1 Through These sections are very similar to those discussing the DCPP Done 9.1.3 median GMC models. Please review those Chapter 8 comments and apply the relevant ones to the PVGNS discussion in these sections. Nole that some, but not all, of these comments are repeated below. 629. Section 9 .1 , page 9-1 , Please consider writing a more precise statement of the procedure. Done numbered item 4 For example, would it be better described as sampling from the multivariate normal distribution defined by the coefficient covariance matrix? 630. Section 9 .1 , page 9-1 , This statement is impossible to parse. Please consider rewriting to Done item 5 improve its clarity. One option to consider is breaking it into 3 items, the first stating the formation of high-dimensional vectors, each representing the ground motion predictions of a given model for a representative range of predictor variables. the second stating that a metric is defined on that high-dimensional space based on the difference in hazard level between model pairs, and the third stating that the vectors are represented in two dimensions via a (nearly) metric-oreservino maooina orocedure. 631. Section 9.1, page 9-1, Please specify that it is the two-dimensional space (i.e., after the Done item6 Sammon's mapping procedure is applied) that is discretized. 632. Section 9.1.1, page 9-To avoid confusion, having introduced the convention about red and Now there is more than one figure with the color code 2, last paragraph of green weights in connection with Figure 9.1-1, please consider red/green. section noting that Figure 9.1-1 itself does not actually show any statistical-sampling (green) weights. Also, since only one additional figure in the chapter, Figure 9.2-1, actually uses the red/green convention, it would be clearer to simply name that figure. rather than saying In Figure 9.1-1 and subsequent" 633. Section 9.1.2, Page Please describe and show the misfits to the predictions from the The misfits have nothing to do with the weights. It does not 9-2. First Paragraph, original GMPEs by the RRuP*based and RJa-based common forms. matter because they give almost same hazard results Line 8 Please discuss whether the weights (0.7, 0.3) assigned to the RRuP-based and RJa-based branches, respectively, are consistent with the misfits. 634. Section 9.1.3.1, Page Please review whether using a term like "distribution" or "center. Clarification added 9-2. First Paragraph, body. and range" would be more appropriate here than using just the Line 1 tem "range. There are other instances throughout Chapter 9 where the term "range" is used. Please also review those instances and revise where appropriate. 635. Section 9.1.3.2, Page Please explain why the Tl Team limits the dataset to events with at The justifications are given in Chapter 5 9-5. 2"0 paragraph of least 3 recordings per earthquake and whether such a limit is also section (1 used in the DCPP evaluation. Paragraph on page), 1" line on page 636. Section 9.1 32. Page In Figure 9.1-7, the M 6.6 event appears to have just one recording. The plot has been removed, instead we point at the plots in 9-5. 2"0 paragraph of Please check whether this is an error and revise if needed. Chapter 5 section (1 paragraph on page), 1 sentence on page 637. Section 9.1 32. Page In the preliminary draft of Chapter 5 (noting that we have not yet Same as above 9-5. 2"0 paragraph of seen Rev.O for that chapter), in Figure 5.1.3-2, there are a large section (1 paragraph number of recordings that appear to come from a single M 6 9 on page), t" sentence normal-faulting event. These data are not included in Figure 9.1-7. on page Please explain why they are not included in Figure 9.1-7 and are not used for PVNGS. 638. Section 9.1.3.2, Page Please verify that the 2009 M 6.3 L'Aquila earthquake is included in Clarification added. We used the datasets are provided and 9-5, 2"0 paragraph of the EURPV-Meo data set. If not. please explain why not. Also. please did not evaluate if the same events were included in the section (1"' paragraph discuss whether all European events in the PEER NGA-West2 altemative datasets on page), last database satisfying the minimum of 3 recordings-per-event sentence requirement are captured in EURPv*MED* If not, please explain (preferable in Chapter 5) why they were excluded. Conversely, please discuss if all EURPv-Meo events are included in PEER's NGA-West2 database. If not, please explain whey they were excluded. 639. Section 9.1 32. page Since weighting is used in several different senses in the chapter, Clarification added 9-5, 4th paragraph of please consider adding a phrase to clarify that there is no section (3'0 on page), reweighting of different style-of-faulting cases in the calculation of the last line mean-residual and likelihood. if that is the meaning that is intended here. 640. Section 9.1 32. Page Please explain what "differences in mean residuals" mean. The Clarification added 9-5, 5tto Paragraph of definition given in Section 6.4.5 does not mention the word section (4'h on page). "difference". Line 3 641. Section 9.1 3 2. Page Please clarify whether the phrase "range of underlying GMPEs" Clarification added 9-5, s*h paragraph of means the range of predictions of the median amplitude by the section (4'h on page). underlying GMPEs. Also, please clarify whether the epistemic-Last Sentence uncertainty versions are also used in the evaluation of mixing weights. 642. Section 9.1.3.2, Page Please discuss the Tl Team's assessment of the quality of the No further evaluations provided 9-6, 7'h paragraph of EURPv-Meo dataset, such as issues related to record screening (for section (1"' Paragraph example, removal of low signal-to-noise ratio records and non-free on page), Line 4 field records), record processing. and accuracy of magnitude estimates. Also please clarify whether both data quality and data coverage in the key magnitude range are considered in the Tl Team's assessment of relative weights. If the answer is yes, please document Tl Team's evaluations and conclusions. If the answer is no, please provide further justification of the ratio of 3: 1, accounting for these two additional considerations. 643. Section 9.1.3.3, page Please correct this term to the correct term "cumulative distribution Done 9-6, 1" paragraph of function. section, line 2 644. Section 9.1.3.3, page For the NGA dataset. the residual approach (blue curve) seems to Clarification added 9-6, 1" paragraph of give a narrower distribution than does the likelihood (orange curve). section, 2°d to last If this is true, it contrasts with the categorical statement to the sentence contrary in the text, which is confusing (even though it doesn't vitiate your main point about the advantages of the weighted model). Please clarify. 645. Section 9.1.3.3, page As in Chapter 8. please correct the phrase "distance scaling and Sen1ence corrected 9-7, ih paragraph of distance scaling". section (4111 on page). line 2 646. Section 9.1 3 3. page 9-8, g*h paragraph of section (2°d on page). Please substitute "and" for the slash between California and Mexico Done throughout the report line4 647. Section 9.1.3.3, Page Please explain why the uncertainty in hazard shown in Figure 9.1-Done 9-8, gth paragraph of 19a (for Model A) is much larger than the hazard uncertainty shown section (2"" on page). in Figure 9.1-19b (for Model B). _ Lines 5 to 7 648. Section 9.1.3.3, Page Please clarify whether the mean hazard is weighted by the branch That's the definition of the mean hazard, which has the 9-8, 1 O'" paragraph of section (3'" Paragraph weights. branch weights in it. No change in text. on page), Line 1 649. Section 9.1.3.3, Page Please include in Figures 9.1-19 and 9.1-20 a curve representing the See answer to 649 9-8, 1 O'" paragraph of average hazard from the original GMPEs. section (3'0 Paragraph on oaae}. Line 2 650. Section 9.1.3.3. Page Please explain why the epistemic versions of the original GMPEs We added a new figure with the mean hazard from the 9-8, Last Paragraph of are not included in Figures 9.1-19 and 9.1-20 to help judge the candidate GMPEs, and from the candidate GMPEs with section appropriateness of the selected common-form models in capturing additional epistemic uncertainty, in the same way we did in the CBR of the median motion. Chapter 8 651. Section 9.1.4, page 9-Please express quantitatively what is meant by "nearby" (where Done 8, 1 *1 paragraph of there are no known faults), and give the justification for neglecting section, line 1 directivity effects for identified faults outside that region (or specific reference to a report section that provides the justification). 652. Section 9.14, Page Please further clarify the statement 'The GMPEs capture this Clarification added 9-8, Line 6 random case" and how it supports the Tl Team's decision to give zero weight to the directivity adjustment branch. 653. Section 9.1.5, Page Please indicate that the tectonic regime of the Wells earthquake is Done 9-9, 1st Paragraph, the same as for the PVNGS site region. but that the tectonic regime 2nd Sentence for the Japan earthquake is not. 654. Section 9.15 1. Page Without plotting residuals against the directivity parameter, it is Discussion on directivity has been removed 9-9, 2"" Paragraph, difficult to form a definite conclusion regarding the existence or the Second Sentence level of the directivity effect. Please either add a plot to support the conclusion or revise the sentence to be less definite. 655. Section 9 .1 5 1. page 9-9, 2"d paragraph, Please replace "with respect the" with "with respect to." Done line 5 656. Section 9 .1 5 1. page PGV residuals are not shown in Figures 1-15 and 1-16. According to The text "In contrast, the PGV data are much lower than 9-9, paragraph 2, line Appendix I (Section 1.3.2, Second Paragraph). residuals in Figure I-GMPEs with an average residual of -0.74 natural log units." 5 15 are with respect to CY14 only, not to the four NGA-West2 has been removed GMPEs. Also. residuals shown in Figure 1-16 are averages over six candidate GMPEs. Please revise this paragraph to be consistent with Appendix I. 657. Section 9.151. Page Because the Wells earthquake occurred in the same tectonic regime Residuals wrt Bi14 and ASB14 were evaluated in Figure 1-9-9, 2nd Paragraph of as the PVNGS site, its ground motion is very relevant to 17. Residuals for various periods were evaluated with Section, Last understanding the ground motions that might occur at PVNGS from respect of CY14 in Figure 1-16. Evaluation of the data is Sentence normal-faulting events. Please state what conclusions were drawn included in Chapter 9 from the observations regarding the validity of the NGA-West2 GMPEs to estimate normal-faulting ground motions at the site. Please also indicate why neither the Bindi et al. (2014) GMPE nor response-spectral values in addition to PGA and PGV were evaluated. 658. Section 9.1.5.2. Page Please clarify whether the definition of a complex rupture adopted by Clarification provided 9-9, First Paragraph, the Tl Team is applicable to the case of disjoint ruptures as seen in Line 1 the Fukushima-Hamadori earthquake. 659. Section 9.1.5.2, Page Please justify that the SSRS method is the preferred method for Discussion added 9-9, First Paragraph, computing ground motion from the Fukushima-Hamadori Line 5 earthquake, given that the evaluation of alternative methods for complex ruptures (Section 6.7 and Sections J.2.2 and J.3.2) does not include disjoint rupture scenarios as seen in the Fukushima-Hamadori earthquake. 660. Section 9.1 52. Page Please explain why the Bindi et al. (2014) GMPE was not evaluated, Yes, the Japanese factors were used for the GMPEs that 9-9, First Paragraph, given that it was one of the candidate GMPEs. Please also indicate if include those. Bindi et al. (2014) and Akkar et al. (2014) do 4'" sentence the Japan regional factors in the NGA-West2 GMPES were used to not have Japan-specific terms and were not evaluated evaluate the Fukushima-Hamadori, Japan earthquake. 661. Section 9.1 5 2. Page Please provide a figure similar to Figure 9.1-21 for the Wells Not done at this time 9-9, 1st Paragraph of earthquake. Section, 7th Line 662. Section 9.1.5.2, page Please consider whether an accessible document can be cited Tl T earn evaluation is now provided 9-9, 3r0 paragraph of instead of personal communication, and if not, consider whether the section, line 2 observation cited is of real significance to the assessment. 663. Section 9.1.5.2, page The personal communication cited here entails a claim of local See answer to 662 9-10, 3r<1 paragraph of stress heterogeneities. without reference to a data source. and a section ( 1 *1 on page), "suggestion" about rupture behavior that is difficult to distinguish from lines 9-14 simply an offhand speculation. Please consider first whether this passage is essential to the Tl Team's assessment. If so, please consider whether there is a documentary source for the observation of stress heterogeneity. Also consider whether stating a Tl Team judgment (based on review of the available evidence) that the event cannot be discounted (as an Arizona proxy) might be as authoritative, and more direct, than citing Dr. Stein's undocumented suggestion. 664. Section 9.1.5.2, page Please reference where in the report and/or appendices the Comment inserted into Chapter 9 9-10, 4"' paragraph of additional variability gleaned from the evaluation of the Wells and section (2"" on page), Fukushima-Hamadori earthquakes is taken into account. 665. Section 9.2, Page 9-Please explain why the Sammon's mapping approach was not used A new plot is now available, showing PSA scaling versus 10, General to develop the set of models used to estimate ground motions from distance, for the NGA-W2 models corrected for the median the distant California and Mexico sources in Regions 1, 2, and 3. path terms and their uncertainty (15 curves) -separate plots Please also include figures to demonstrate the distribution of ground are provided for each region (Region 1 and combined motion values that are implied by the logic-tree model that Regions 2&3) represents these sources. 666. Section 9.2.1, page 9-The phrases "California/Mexico" and "California -Mexico" should Done 10. paragraph 1 read "California and Mexico." 667. Section 9.24, Page Please specify the applicable distance range of Al-Atik and Youngs Clarification added 9-11, First Paragraph. (2014) and comment on its applicability to the distant California and Line 4: Mexico sources. 668. Section 9.24 1. Page First Paragraph of Section 9.2.4 indicates that this section is about Clarifications added 9-11, 1 "' Paragraph of epistemic uncertainty in median prediction by the NGA-West2 section, Line 4 GMPEs, whereas this sentence and the remainder of this subsection indicate ifs about uncertainty in the path effect. This is very confusing. Please clarify or reorganize as needed. 669. Section 9.2.4.1, page Please cite the relevant appendix section(s) and figure(s) where the Done 9-11, 1"' paragraph of details are given. section, lines 6-9 670. Section 9.2.4.1, page Please provide a reference and clear explanation for the equation. Done 9-12, Eqn 9.2-1 671. Section 9.2.5, Page A description of the standard deviation used by the Tl T earn to Reference to Appendix P added 9-12, Second compute the 5'" and 95'" values is missing. Please provide such a Paragraph, Line 1 description along with Tl Team's justification for the value used. That description should also clarify why the weights stated at the end of Section 9.2.4.2 and elsewhere in the report differ (slightly) from the 0.185, 0 63 and 0.185 weights used by Al Atik and Youngs (2014) and recommended by Keefer and Bodily. 672. Section 9.2.6, Page Please provide a reference for 1he sta1ement that "The distant Clarification added 9-12, 1st Paragraph of California strike slip sources are located at distances well beyond Section, 1st Line where directivity effects are observed in the empirical data. 673. Section 9.3, page 9-Please see previous comments regarding the list of references for Common issues fixed (e.g., citation volume/issue/pages, 13, General comment other chapters and appendices for guidance on revising the list of 2014a vs. 2014, etc.) references in this chapter. 674. Figure 9.1-1, page 9-The caption should include the information on the meaning of the Done 15 red and green weights (as discussed in the text), while noting that 1here are no statistical (green) weights presen1 in this case. 675. Figure 9. 1-2a, Page Please indicate the type of residuals (i.e., between-event, within-Done 9-16, 5th Line of event, total) here and elsewhere throughout the chapter when the Caption term "residuals" is used. 676. Figure 9. 1-2 & 3, Please provide a label giving the color bar units, or provide that Done pages 9-16 to 9-19 information in the caption 677. Figure 9. 1-5, page 9-Please rewrite the caption to correct typographical errors and make Done 21 it more informative. 678. Figures 9.1-8, page 9-The caption in each of these figures should be corrected to read Captions corrected 24: and 9.1-9, page 9-"cumulative distribution function." Please also improve the readability 25 and resolu1ion of 1hese figures and several subsequent ones-they are fuzzy and the numbering is nearly illegible. 679. Figure 9.1-14a-e. All of the influence plots are fuzzy and need improved resolution. Captions improved pages 9-30 through 9-Plus, the lettering is too small and illegible. The captions could be 34 improved with better explanations of the plots. CHAPTER 14 Hazard Sensitivity 680. General comment Subjective sta1ements such as "main contributing, controlling, Done to the best of ability significant, small, little impact", etc. are used throughout the chapter to describe results. Please provide a quantitative description of such statements in order to avoid ambiguity. 681. Section 14.1, Page Please provide specific references (i.e., documents or presentations) A new table has been inserted 14-1, 1st Paragraph, to the hazard sensitivity studies that were provided throughout the 1st Sentence project. 682. Section 14.1, page The sensitivity estimates have been invoked at many points in the Goal is to capture the type of sources that are contributing, 14-1, 1"' paragraph report as a rationale for various model simplifications. Therefore, so that's ok for us please consider adding a short discussion to further justify the validity of using the earlier SSC models for DCPP and PVNGS as the base case for this purpose (and emphasizing that the older models are used only for that purpose). 683. Section 14.1, page Has the acronym "NPP" been defined. or even used at all elsewhere Done 14-1, 2°d paragraph of in the report? Please consider whether it is worth introducing this section, line 3 acronym and defining it here, in lieu of just writing out what it means. 684. Section 14.1, page If the term tornado plot" has not been defined earlier in the report, Description provided 14-1, paragraph 3 of please provide a brief description of its form and construction. If section, 3*c sentence there was an earlier definition given, please provide a specific section reference. Please also clarify that the y-axis value alluded to at the end of the sentence is that of the hazard curve, not that of the tornado plot itself. And since not all of the sensitivity studies are summarized in Tornado plots (e.g., the source contributions are shown as graphs and deaggregation histograms) please indicate that these other results are shown in other formats 685. Section 14. 1, page Please clarify the meaning of "weighted mean" in this context (e.g., Done 14-1, 3rd paragraph of how are the individual ratio values weighted?). section, line 6 686. Section 14.1, Page This statement implies that the results could be different enough to Our sensitivity analysis is not representative of final hazard 14-2, last paragraph be of concern. In this case, please justify why it is sufficient to use level, but is representative of the contribution from the of section (1st on the older SSC models for the hazard sensitivity studies. Please also different branches. A clarification has been provided page), Last Sentence consider moving this caveat and its discussion and justification to Section 14.1 at the beginning of the chapter as recommended in an earlier comment. 687. Section 14.2, page Here. and elsewhere in the report (e.g .. Section 14.2, Page 14-4). Done 14-2, paragraph 1. please add "fault" after Shoreline. Los Osos, San Luis Bay. etc. lines 2 & 6 These are formal names and should be spelled out in full. 688. Section 14.2, Page Please indicate how the fractional contribution of the different Clarification provided 14-2, 1st Paragraph of seismic sources to the total mean hazard was determined. If ii was Section, 2nd done using deaggregation, please indicate that this is the case and Sentence define what deaggregation is and how it is done prior to discussing the results. 689. Section 14.2, Page Please indicate that the deaggregation is done on the mean hazard Clarification provided. That's the only way it is done. 14-4, 1st Paragraph here and elsewhere thought the chapter and appendices. on page, 1st Line 690. Section 14.2, Page Please also show the 10*0 hazard deaggregation histograms for Done 14-4, 1st Paragraph completeness. on page, 1st Line 691. Section 14.2, Page Please explain how the deaggregation histograms show that the Clarification added 14-4, 1st Paragraph hazard at DCPP is controlled by the four local faults when no on page, Last sources are identified in these plots. Sentence 692. Figures 14.2-3 and The entire report addresses hazard on a reference site condition Done 14.2-4, Pages 14-5 corresponding to Vs30 = 760 m/sec. Because of this. ii is confusing and 14-6, Figure to describe the hazard as being for "rock". Please delete the word Captions rock to avoid confusion. 693. Section 14.2.1, Page Please change 14.3-6b to t4 2-6b Done 14-6, First Paragraph, Last Line 694. Section 14.2, Page Please consider revising the x-axis title in this figure and other Additional explanation of the tornado plots addresses this 14-8, Figure 14.2-Sa similar figures in Chapter 14 to reflect the no1111alization of ground-question See comment 684 motion ratio discussed in Paragraph 3, Page 14-1. 695. Section 14.2.2, page This sentence would benefit from minor rewording to avoid Done 14-11, paragraph 2, ambiguity. Please consider whether its meaning could be correctly last line on page rendered by ..... with the weighted average of the phi ** models, including only the central aleatory-variability branch on phi." 696. Section 14.2.2, page Please refer to specific figures when referring to "the fifth line ... ". Done 14-12. 4th paragraph This needs to be done throughout this section (next several of section (3'd on paragraphs) and the remainder oflhe chapter, as the absence of page). line 3 and specific references leaves some ambiguity as to which tornado plot elsewhere is being cited. 697. Section 14.2.2, Page The sensitivity oflhe mixture high model appears to be as great as Done 14-12. 7'" paragraph many of the other parameters. Please consider revising this of section (6th on statement to better reflect the results shown in the tornado plots. page) 7th Sentence 698. Section 14.3, page Please check lo ensure that all of the names and abbreviations that CP and CP-F corrected. The nomenclature is consistent 14-21, abbreviation are listed here are used consistently throughout the report. For with the LCI 2013 PVNGS SSHAC level 2 SSC zonation. lists instance, is Gulf of California referred to as GZ consistently (and not Note that the PVNGS L2 report mixes between GF and GC) and why is the -F added to CP for Colorado Plateau? This is GULF. We have chosen GULF now to be consistent with potentially confusing, because CP is listed here for the Cerro Prieto most of the figures and their Level 2 HID fault (and ii would seem more logical to have the F identifying a fault). Please also reference this list back to a figure. 699. Section 14.3, page Please revise this statement to make it clear whether the 99% Done 14-2 t. 1 ** sentence contribution to the total hazard is from the background (area?) after bullet 11 sources, the fault sources, or the combination of both. 700. Section 14.3, page Please specify which faults are the distant fault sources. Done 14-22, 1"' paragraph after bullet 26, 1" line 701. Section 14.3, page Please clarify which modeling choices were made by LCI (2013) and Clarification added 14-22. 1st paragraph which ones were made by the Tl Team. Regarding those made by after bullet 26, and the Tl Team, please justify the choices made with respect to their 3'd sentences implications in identifying hazard-sensitive models and parameters. 702. Section 14.3, page Please be specific and precise about the meaning oflhe phrase " ... a Done 14-22. 1** paragraph pure characteristic earthquake magnitude distribution ... " as used in after bullet 26, line 7 this context 703. Section 14.3, page 14-22. 2"" paragraph Please explain how the source contributions were calculated. Done of page after bulleted items, t sentence 704. Section 14.3, page Please justify the use of the specific sigma value of 0. 65. The correct sigma value is the one from BSSA14. 14-22. 2"" paragraph Clarification added of page after bulleted items, 4'" line 705. Section 14.3, page Please add the missing word "greater before "than in the phrase Done 14-22. 211* paragraph "For ground motion values than 0.1 g. of page after bulleted items, line 7 706. Section 14.3, page If this paragraph is intended to be a summary of the results in The corresponding hazard level is provided to clarify the 14-24, 1" paragraph Figures 14.3-1 and 14.3-2, please explain how one reconciles the statement. on page categorical statements in this paragraph with the period-dependent results in the figures. For example, Figure 14.3-2 appears to indicate that SBR sources dominate 0.5 Hz hazard at levels exceeding about 0.15 g, which appears to contradict the categorical statement that "distant fault sources are the dominant contributor to hazard at lower spectral frequencies." Shouldn't the statements in this paragraph be conditional on something (e.g., the probability of exceedance range of interest)? Please also indicate whether this apparent contradiction is related to the observation made later in Section 14.3, Page 14-25, top 2 lines on page. 707. Section 14.3, page Please quantify what is meant by "local small" and "distant large" in Clarification added 14-24, 2"' paragraph this context. on page, 2"d and 3r<1 sentence 708. Section 14.3, Page Please also show the 10-0 mean annual hazard deaggregation Done 14-24, 2nd Paragraph histograms for completeness. on page, 4th Sentence 709. Section 14.3, page This observation may be related to the above comment made about Addressed in response to 706 14-25. top 2 lines on Section 14.3, Page 14-24, t" paragraph on page. page 710. Section 14.3.1, page The phrase "there are not known active faults" is at best an awkward Done 14-27. 2"" paragraph construction, and potentially ambiguous. Please reword for clarity. of section ( 1 *1 on page). line 1 at top of page. 711. Section 14.3.1, page Please provide reference to the report section where the neglect of Done 14-27, 2"' paragraph directivity effects was justified. of section (1"' on page), top 2 lines on page 712. Section 14.3.1, page Please indicate what the statement "little impact" is compared to. Done 14-27. 3rd paragraph of section (2"" on page). 713. Section 14.3.1, page Please refer to specific figures that are related to this discussion. Done 14-27. 4"' paragraph of section (3'd on page) 714. Section 14.3.1, page The explanation of the greater range at lower hazard level in terms Further explanations provided 14-27. 4*h paragraph of depth scaling requires some amplification. Please provide some of section (3'd on further explanatory remarks. page). lines 9 and 10 715. Section 14.3.1, page Please add the missing word "for in the phrase " ... lo the hazard and Done 14-27, 4*h paragraph produce a noor the hazard estimate ... " of section (3rd on page), line 15 716. Section 14.3.1, page Please revise this statement to clarify its meaning (i.e., are the Yes they are fractional contributions. We think the 14-27. 41h paragraph values shown really fractional" contributions?) sentences are clear of section (3'd on page). last sentence 717. Section 14.3.1, page Please refer to specific figures that are related to this discussion. Done 14-27. S"' paragraph of section (411' on page), general comment 718. Section 14.3.1, page Please consider rewording this sentence so as not to categorize the Done 14-27. 5"' paragraph GMPE prior estimate as a "dataset." The subject here is really of section (41"' on sensitivity to elements of the weighting scheme for the median base page), 1" sentence models (Figure 9.1-5), only some of which are datasets. 719. Section 14.3.2, page Please provide a reference to the report section where the neglect of Done 14-31. 1 *1 paragraph directivity effects was justified. of section. 2*** sentence 720. Section 14.3.2, page Please refer to specific figures that are related to this discussion Done 14-32, first 3 paragraphs on page 72t. Section 14.3.2, page Please clarify where in the report the additional epistemic cross reference provided in page 14-33 14-32, 4*h paragraph uncertainty in the magnitude scaling is discussed and which node in of section (3rd on Figure 9.2-1 models this uncertainty. oaoel, line 1 722. Section 14.3.2, page It should be clear at this point that the different model sensitivities We do have a changing base but normalized to be 1. 14-32, 4'" paragraph are with respect to a common base case (ie .. the denominator) and; Clarification added of section (3"' on therefore, all represent changes in the numerator. Please remove page). line 3 this reference to the numerator in order to avoid confusion that these results are somehow different than the previous ones. 723. Section 14.3.2, page This sentence is poorly written (including seemingly redundant Sentence rewritten 14-32, 4*h paragraph constructions such as "approach application and "in with"). Please of section (3rd on rewrite this sentence for clarity and precision. Also, please check page). lines 7 & 8 whether the "i.e." in the parenthetical note correctly conveys the intended meaning (i.e .. the i.e" implies some sort of equivalence between the preceding clause and the parenthetical observation, which mav not be intendedl. 724. Section 14.3.3, Page Please do not use a slash (e.g., in the term the Phiss/PhisP*R) unless Done throughout the report 14-36, 1st Paragraph, it is intended to represent a ratio here and throughout the chapter. 2nd Line 725. Section 14.3.3, Page Please explain why the BSSA 14 GMPE was used for the sigma Explanation added 14-36. 1st Paragraph, sensitivity studies and the CB14 GMPE was used for the median 6th Line sensitivity studies. 726. Section 14.3.3, Page Please provide, in the text, the spectral frequencies that are Done 14-36. 2nd associated with Figures 14.3-9 and 14.3-10. Paragraph, 1st Line 727. Section 14.3.3, Page This is the first time that the values of ratios are given. Please be The ratios values are removed 14-36, 2nd consistent in either providing such ratios or not providing them Paragraph, 41h Line 1hroughout the chapter. If the ratios are not provided, the subjective statements describing these ratios should be quantified (see General Comment on this chapter). 728. Section 14.3.4 page 14-41. 3*d paragraph Please reference specific figures related lo this discussion. Done of section ( 1 *1 on oaael 729. Section 14.3.5, page Please check whether "0.5 Hz should be "5.0 Hz." Checked 14-46. 3rd paragraph of section ( 1 "' on page). line 1 730. Section 14.3.5, page Please describe the three models that are shown for the "with path Done 14-46, 4'h paragraph and 'without path" rows in Figures 14.3-13a, 14.3-13b, 14.3-14a, and of section (2nd on 14.3-14b. page), 1*1 sentence 731. Section 14.3.5, page Please consider whether the intended meaning of this sentence Done 14-46, 4'h paragraph would be better conveyed by "because of' rather than "based on" of section (2"d on page). line 4 732. Section 14.3.5, page This statement does not seem to be consistent with the figures. Done 14-46. S"' paragraph Please revise this statement to better reHect the results shown in the of section (31d on tornado plots. page). 6'" sentence 733. Figure 14.3-13b, page The caption reads correctly that this plot is for 5 hz (as stated in the The correct figure is now inserted 14-48 tex1) but the header of the figure reads 0.5 Hz. Furthermore, the plot looks identical to Figure 14.3-14b. Please make sure this is the correct plot and either correct the header or replace it with the correct plot. 734. Section 14.3.7, Page Use of the term distribution is confusing. Please consider replacing Done 14-54, 1st Paragraph, "distribution" with "sensitivity". 9th Line 735. Section 14.3.7, Page The NGA-West2 models only show significant sensitivity at 0.5 Hz, Done 14-54. 1st Paragraph, so this general statement is confusing. Please consider deleting this 101" Line sentence and making statements regarding the impact of these models separately for 1he two frequencies. 736. Section 14.3.7, Page Use of the term uncertainty is confusing. Please consider replacing Done 14-55, (1st "uncertainty" with "sensitivity". Paragraph, 3rd Line 737. Section 14.4, Page Please see previous comments regarding the list of references for Common issues like volume/issue/page numbers fixed, not 14-58. General other chapters and appendices for guidance on revising the list of cited references removed references in this chapter. APPENDIX H Evaluation of Common Form Models 738. General The format of the appendix is different from that of the report and The format and content of Appendix H was not modified in other appendices. Please reformat the appendix to be consistent Rev.1 with the rest of the report. In Rev.2 instead, the introductory material of Appendix H was a summary of Attachment E (not provided anymore), and included also the explanation of the plots. All the other information on dataset and candidate GMPEs is already provided in the main report, and were removed from the Appendix H. In both versions of Appendix H in Rev1 and Rev.2, we were not in control of the formatting of the material. 739. Chapter 1, General The text is very cryptic and contains a myriad of terms and See answer to comment 738 acronyms, making it comprehensible to only those that have a good understanding of the topic. Please expand the text to be more descriptive and ensure that all of the used terms and acronyms have been clearly defined in the main report prior to referencing the appendix or. if not, that they are defined in the appendix the first time they are used. 740. Chapter 1. Tables 1 . 1 The table captions should specify units for the ground motion levels. See answer to comment 738 and 1.2, page 2 741. Chapter t. Section Please indicate what the GMPEs are used for. See also 1st Line of See answer to comment 738 1.1, Page 1, 4th 5th Paragraph. Paragraph, 1st Line 742. Chapter t. Section Please replace "(2014)" with "(2014a,b)" in the Akkar et al. (2014) See answer to comment 738 1.1, Page 1. 4th reference to indicate that both the original manuscript and the Paragraph, 2nd Bullet erratum were published in the same year and add the reference to the erratum in the list of references. See also 3rd Bullet in 5th Paragraph. 743. Chapter 1, Section Zhao and Lu (2011) do not present a GMPE, but rather an approach See answer to comment 738 1.1, Page 1, 4th to magnitude-scaling at large magnitudes. Please define a new Paragraph, 8th Bullet GMPE that incorporates the proposed magnitude-scaling in Zhao and Lu (2011) and identify it by a unique acronym. 744. Chapter t. Section Please replace "(2014)" with "(2014a,b)" in the Bindi et al. (2014) See answer to comment 738 1.1, Page 1, 5th reference to indicate that both the original manuscript and the Paragraph, 3rd Bullet erratum were published in the same year and add the reference to the erratum in the list of references. 745. Chapter 1, Section Please add the missing word "not" in the phrase "but do See answer to comment 738 1.1.1, page 3, paragraph 1 , 2"" to incorporate". last line 746. Chapter t. Section Please justify the basis for the weights assigned to the median and See answer to comment 738 1.1.1, Page 3, 2nd plus/minus uncertainty of the GMPEs. Paragraph, 7th Line 747. Chapter t. Section Please define the meaning of the term "total weights". See answer to comment 738 1.1.1, Page 3, 3rd Paragraph, 1st Line 748. Chapter t. Section Please avoid the use of slashes (e.g., in width/range) unless it is See answer to comment 738 1.1.1, Page 3, 3rd intended to represent a ratio. Paragraph, 3rd Line 749. Chapter 1, Section Please define the meaning of the term "all weights" and how it differs See answer to comment 738 1.1.1, Page 3, 7th from the term total weights". Paragraph, 2nd Line 750. Chapter 1. Section Please reference the logic tree that documents the weights that are See answer to comment 738 1.1.1, Page 3, 8th assigned to Models A and B for PVNGS. Paragraph, 2nd Line 751. Chapter 1. Section Please update the references to the various datasets to use the See answer to comment 738 1.1.1, page 3. 8"' terminology introduced in Chapter 5, and reference the appropriate paragraph, line 5 section and table from that chapter. If the term "weighted NGA dataset" is not explained in Chapter 5, please explain that term here. 752. Chapter t, Section Please clarify what those" refers to in what appears to be part of an See answer lo comment 738 1.2, Page 5, 1st incomplete phrase. Paragraph, 1st Line 753. Chapter 1, Section Please provide references to the simulation methods of EXSIM, See answer lo comment 738 1.2, Page 5, 1st Graves and Pitarka (i.e., G&P), and SDSU. Paragraph, 3rd Line 754. Chapter 1, Section Please clarify what "models" are being referred to. See answer to comment 738 1.2, Page 5, 1st Paragraph, 5th Sentence 755. Chapter 1. Page 7. Please ensure that all of the references are cited in the text and are See answer to comment 738 Bibliography complete, and add missing references identified in the text. 756. Chapter 2. General Please provide a short introduction to the figures that are presented See answer to comment 738 in the report. 757. Chapter 2, Section Please provide units for the legend bars in the figures showing the See answer lo comment 738 2.1.2 Sammon's maps. 758. Chapter 2. Section Please explain why the distribution of hazard curves for the selected For discussion on the main chapters. not in the appendix 2.1.4 models covers a smaller range of hazard than that for the 2000 curves and what impact that has on the final results 759. Section 2.1.4, Page To help visually compare the hazard distribution from the selected For discussion on the main chapters. not in the appendix 53, Figure 2.69 model to the distribution from all 2000 sampled models, please add the 5%, 50%, and 95% curves of the latter distribution to bo1h plots. Also please increase the size of each plo1 for ease of viewing. 760. Chapter 2. Section Please define the acronyms in the legend that are used to describe Done 2.1.5 the GDF curves in the figures. Also please change "cumulative density function" to "cumula1ive distribution function" in all captions, here and throughout the report. 761. Section 2.1 6, Page Please explain what causes the ramp-up of the lower black curve on For discussion on the main chapters. not in the appendix 106, Figure 2.202 this figure and other figures. 762. Section 2.1 . 7, Page Please explain what causes the ramp-up of the lower red curve on For discussion on the main chapters. not in the appendix 107, Figure 2.208 this and other figures. 763. Section 2.1.81.4.7, Please explain why, at Rx= -1, the GMPE distribu1ion is much more For discussion on the main chapters, not in the appendix Pages 137 and 140, sensitive to the value of F (style-of-faulting flag) than the Model A Figure 2.272 vs. distribution is. Figure 2.281 764. Chapter 3. General Please see comments for Chapter 2. Ok 765. Chapter 4, General Please see comments for Chapter 2. Ok 766. Chapter 5. General Please see comments for Chapter 2. Ok APPENDIX I Wells (NV) Earthquake 767. Section 1.1, Page 1-1. Please provide a reference for the statement that "The tectonic Added reference to Chapter 4 where the the topic is 2nd Paragraph, 1st setting, magnitude, and focal mechanism of this earthquake are all discussed Sentence consistent with the seismic sources in the Southern Basin and Range that contribute significantly to the hazard at high frequencies at the Palo Verde Nuclear Generating Station (PVNGS)". 768. Section 1.1, page 1-1, The acronym" NGA-W2" was given as "NGA-West2" elsewhere in Done throughout the Appendix 2"' paragraph, line 5 the report. Please standardize the terminology and acronyms throughout the report. 769. Section 1.2.1, Page 1-Please provide a summary of instrument response, sampling time Information such as 40 samples per second, broadband 1, 1 *1 Paragraph of interval, and possible limitations of the USTA recordings for use in seismometer, flat response in the 0.01 -16 Hz frequency section, Line 7 the comparison with GMPEs described in Section 1.3. range, etc were added to the text Limitation is that PSAs below 0.075 sec are not reliable due to sensor response. Specs and limitations described in the text 770. Section 1.2.1, page 1-US Transportable Array is abbreviated "USTA" here, while TA used everywhere in the Appendix 1, 1 *1 paragraph. line 7 elsewhere it is referred to as "Transportable Array" and abbreviated as "TA". Please standardize the terminology and acronyms throughout the report. 771. Section 1.2.1, page 1-Please clarify the meaning of the term "temporary stations. If these We clarified that those are TA temporary stations. 1, 1"' paragraph, line 8 temporary stations are the USTA stations, please indicate such in the text. 772. Section 1.2.1, page 1-1, 1 *1 paragraph. last 2 Please add either a period or semicolon following "100km". Period added lines 773. Section 1.2.2, Page 1-Please clarify that the Wills and Clahan (2006) relationships A discussion on the regional dependence of VS30/geology 2, 2nd Paragraph, 1st between geologic units and Vs30 are based on California data and proxy has been added. The estimated impact of a Vs30 Line geology and might not be appropriate for Nevada. Please also uncertainty of about +-0.15 (LN units) on the total residual discuss the potential significance of this assumption on the results. has also been addressed. 774. Section 1.2.2, Page 1-Please provide units for the Vs30 values of 600 and 750 mis. Done 2, 2nd Paragraph, tst Sentence 775. Section 1.2.2, Page 1-Please explain why there is no proxy Vs30 value for Station M12A Done 2, 2nd Paragraph, 2nd shown in Figure 1-2. Later in the text it is noted that this station Sentence clipped and was not used. but that information is not available at the point in the appendix where this figure is referenced. 776. Section 1.2.3, page 1-The record for station N12A also looks clipped in Figure 1-3. Please Record for station N12A is not clipped. No change in the text 2, 1"' paragraph of consider whether that is the case, and if so, whether ii is appropriate section, line 7 to comment on that record as well, in order to be consistent. 777. Section 1.2.3, Page 1-Please explain why a focal mechanism from UCB was used rather The focal mechanism is provided as reference, but the finite-2, 1st Paragraph of than one from a more local source (e.g., the UNR Seismological fault inversion from Dreger et al (2011) was indeed used for Section, Last Laboratory). or from the study of Dreger et al (2011) or the USGS computing the finite-fault distances in a compatible manner. Sentence NEIC. Clarifying text provided. 778. Section 1.3.2, Page 1-Please add the references for Abrahamson et al. (2014), Boore et al. References added 3, 1st Paragraph of (2014), Campbell and Bozorgnia (2014), Chiou and Youngs (2014). Section, 2nd and Idriss (2014) to the list of references Sentence 779. Section 1.3.2, Page I-Please replace "2013 (ASB 13 )" with "2014a ,b (ASB 14 )" and add the References enhanced as suggested 3, 1st Paragraph of Akkar et al. (2014a.b) original manuscript and erratum to the list of Section, 2nd references. Sentence 780. Section 1.3.2, Page I-Please replace "2013 (BIN13)" with "2014a,b (Bi14)" and add the References enhanced as suggested 3, 1st Paragraph of Bindi et al (2014a,b) original manuscript and erratum to the list of Section, 2nd references. Sentence 781. Section 1.3.2, Page I-The statement that the NGA models are a better short-period fit than More precise evaluation is provided. 3, 3'0 paragraph, last the Euro models does not seem correct without a more specific line statement of the period range (e.g., it appears that the absolute value of the average residual is similar between NGA and European datasets up to a period of -0.05 seconds). Please fonmulate the conclusion more precisely. 782. Section 1.3.2, Page 1-This paragraph summarizes the observations of the analysis given in The evaluations are given in Chapter 9, not in this Appendix. 3, 4th Paragraph of Appendix I, but does not provide conclusions whether the Wells No change in the text. Section earthquake data indicate that there is a potential issue with the applicability of the NGA-West2 or European GMPES to the greater Arizona region. Please provide conclusions based on the observed comparison shown in this appendix and demonstrate, perhaps statistically, whether the Wells ground-motion data is consistent with the empirical GMPEs over the period range of interest. 783. Section 1.4, Page 1-3 Please revise the list of references to include missing references Done and to update those references that have incomplete information. 784. Figures I. 1 to I. 14 Please provide missing or more meaningful figure captions. Done for figures 1-1 to 1-14 785. Figure 1.15, Page I-Please indicate that these residuals were calculated with respect to The residuals are now shown for all the candidate GMPEs 19, Caption the CY14 GMPE. 786. Figures 1.16, Page I-Please indicate that the mean residuals are calculated with respect Accurate caption provided 20, Caption to all 7 sites in the upper plot and provide a description of what is shown in the lower plot. APPENDIX J Forward Finite Fault Simulations for SWUS 787. General There are a lot of analyses being described in this appendix. some Issue resolved in Rev.2 of which are attributed to unspecified authors or by the pronouns "I". "we", "our", etc. Please indicate who performed the analyses (e.g., the Tl Team or some other Resource or Proponent Expert) and avoid the use of pronouns, which refer to unspecified authors of the appendix. 788. General comment This appendix deviates stylistically from others, in that some Issue resolved in Rev.2 subsections are given headers but left unnumbered. For example, within Section J.2.2, on Page J-10 there is a heading "Scenario 1: Hosgri that is unnumbered, whereas following convention established in other chapters this should have become Section J.2.2.1. Please edit the chapter for uniformity of style with the rest of the report. 789. Section J.1, page J-1. Please include a reference describing the SCEC Broadband Done. The Dreger et al. (2015) citation was also added Line 1 Platform. For example, a suitable paper would be that published (SRL early online publication for Jan 2015 issue), by Maechling et al Also please define acronyms (such as SCEC) the first time they are used, here and throughout the appendix. 790. Section j. 1, page J-1, For the sake of parallelism of construction, "and extending GMPE" Done Line 4 should read "and to extend GMPE" 791. Section J. 1 , Page J-1 , Please include additional text in this sentence lo reflect the use of Text has been added discussing the use of simulations for Line 5 simulated data by the Tl Team in Chapter 8 to select and assign analyzing ground motion Sammon's space and assigning weights to the selected models for DCPP (Figure 8.2-2). Also, please logic tree weights. A reference to Table 8.4-1 that defines add a summary. including tables, of the fault paramelers used to lhe parameters of the simulations used has been added. obtain the Chapter 8 simulated data, or reference the section where such a summary is provided. 792. Section J.1.1, Please explain whether the validation process uses a performance Text was added that explains the Tl Team's basis for using General measure that specifically evaluates the capability of simulation a HW factor derived from simulations methods in modeling hanging wall effects. If not, please explain the Tl Team's basis for trusting the HW factor derived from the simulations. 793. Section J.1.1, page J-The acronym "G&P" is given as "GP" elsewhere. Please use a Changed to GP throughout 1, 1"' paragraph of consistent acronym throughout the report. section, line 7 794. Section J.1.1, page J-In addition to the cited report, there is a peer-reviewed publication in The SRL special issue papers for all of the 5 simulation 1, 1"' paragraph of (SRL early online publication for Jan 2015 issue) by Dreger et al, methods have been referenced. The citation to Dreger et al.. section line 8 describing the BBP methods review, which could usefully be 2013, 2015 was moved to the following paragraph describing referenced here. The individual BBP methods each have individual the charge of the validation panel. peer-reviewed papers in the same SRL issue, and these should be cited as well. 795. Section J.1.1, Page J-There were issues attempting to open the URL from the link given in The link was removed since it would not be useful in print 1, 1st Paragraph of the appendix, although it worked when pasted into Microsoft Internet versions of the report. Section, Last Explorer. Please correct this link or indicate that it should be pasted Sentence into a web browser. 796. Section J.1.1, Page J-The pseudo spectral acceleration (PSA) referred to here is also The connection between PSA and RotD50, and a reference 1, 2nd Paragraph of referred to as RotD50 spectra elsewhere in the appendix. Please to Boore (2010) has been added. Section, 2nd Line choose a single term for PSA and use it consistently throughout the appendix and. preferably, the report and other appendices for consistencv. 797. Section J.1.1, Page J-Please provide references for the NGA-West1 project and the A citation to Goulet et al. (2015) was added since that paper 1, 2nd Paragraph of specific NGA-West1 GMPEs lhal were used for the Part B validation. describes the framework of the validation process. and the Section, 3rd Line definitions of the Part A and Part B validation tests, including how the NGA-West1 and NGA-West2 GMPEs were used. 798. Section J.1.1, Page J-Please provide a reference and/or link to the SCEC BBP workshop There is no proceedings, only the panel report and SRL 2, 1 "' Paragraph on proceedings. paper, which have been referenced page, 1st Line 799. Section J.1.1, Page J-Please indicate the specific appendix" that is referred to Done 2, 1" Paragraph on page, last line 800. Section J.1.1, Page J-This excerpt from the panel report needs clarification as indicated in Done 2, 2°d paragraph on subsequent comments, even if that requires a format different from a page, general verbatim quote. If one or more direct excerpts are nonetheless comment retained, please use quotation marks and indentation to distinguish paragraph-length quotations from the main text, and quotation marks to distinguish brief ones. 801. Section J.1.1, Page J-Please clarify this statement by replacing "residual" with "value of the Done 2, 2nd Paragraph on residual". page, 2nd Line 802. Section J.1.1, Page J-Please clarify the specific meaning of "performance" here and in Done 2, 2nd Paragraph on ltem4. page, 7th Line 803. Section J.1.1, Page J-Please clarify the meaning of the phrase "equally combining the The text was simplified by indicating the second assessment 2, 2nd Paragraph on absolute value of mean bias with the mean of the absolute value of criteria was the existence or lack of trends in bias within page, 2nd Numbered the bias". which is somewhat confusing as stated. discrete period bins. Item 804. Section J.1.1, Page J-Please explain why the period range 0.01 to 3 sec is deemed Text was added to remark that bias was observed to 2, 2nd Paragraph on acceptable for validating the finite-fault simulation methods. increase at periods greater than 3 seconds for most of the page, Last Line methods 805. Section J.1.1, page J-Please consider whether the parenthetical comment is necessary, Text has been clarified, and the parenthetical comment was 2, 3rd paragraph on and if so, whether the point being made could be clarified. The point removed as it is unnecessary. page, line 3 of the corresponding comment in the SCEC report was only to place the 0.35 natural log unit threshold in context, by comparing ii to the amplitude effect of a 0.1 unit magnitude shift in the limit of large distance and long period. 806. Section J.1.1, Page J-Please provide a reference for the "SCEC review report. Done 2, 3rd Paragraph on page, 6th Line 807. Section J.1.1, Page J-Please explain why the specific ranges of distances and magnitudes It was done to facilitate comparison. The text was modified 2, 4th Paragraph on were selected for the Part B validation. make that point. page, 2nd Line 808. Section J.1.1, page J-Please replace NGS-West 1" with "NGA-West1". Done 2, 4th paragraph on page, sentence 809. Section J.1.1, Page J-Please define these acronyms the first time they are used and Done 2, 4th Paragraph, 2nd replace the year with only the last two letters of the year to be Sentence consistent with how these acronyms are defined elsewhere throughout the report and appendices. 810. Section J.1.1, page J-The description of the upper and lower acceptance thresholds is The description was made more precise, and Goulet et al. 2, 41" paragraph on ambiguous. Please provide a more precise description. (2015) was cited. page, 3"' and 4'h sentences 811. Section J.1.1, Page J-Please indicate what "appendix" is being referred to. Done 3, 1st Paragraph on page, Last Line 812. Section J.1.1, Page J-Please provide the numerical values of the validation magnitude Done 3, 2nd Paragraph on range. page, 3rd Line 813. Figure J.1.1-1:, Page The bias threshold of 0.69 In units is not discussed in the text at this Text was that states it was the judgment of the SCEC J-4, Caption, 3rd Line point in the appendix. Please define why this threshold was selected validation panel that failure criterion for the simulation and how it is used when the figure is first discussed in the text. methods should be a bias threshold of 0.69 In units 814. Figure J.1. t-2:, Page The stated factor of 1. 15 applies to extending the maximum value Done J-5, Caption, 4th Line but not the minimum value. Please indicate what factor (less than one) was used to extend the minimum value. 815. Section J.2.1, Page J-Please define the terms and units in the magnitude-area scaling Done 6, 1st Paragraph of relationship of Leonard (2010). section, Last Line 816. Section J.2.1, Page J-Please replace "Graves and Pitarl<a" with "G&P" to be consistent Done 6, 2nd Paragraph of with the use of this acronym elsewhere throughout the report and section, 2nd Line appendices and use it consistently throughout the appendix. which also sometimes refers to G&P as GP. 817. Section J.2.1. page J-Please correct the extraneous words "A of' at the beginning of the Done 6, paragraph 2 of last sentence of the section. section, line 4 818. Figure J.2. t-1, Page Please also show the M7 scenario on this plot and indicate what dip The dip was added to the caption. The M7 case used J-7 angle is used to make the plot. different stations and cannot easily be added. 819. Section J.2.1, Page J-Please explain why there is no dip variation for the M 7 scenario. Text was added for the reason the number of M7 scenarios 8, Table J.2.1-1 was limited. 820. Section J.2.2, page J-Please provide a reference to the report section where the precise Done 9, paragraph 1. line 1 definition of a "complex" rupture scenario. as used in this project, is given. 821. Section J.2.2, page J-Please consider whether the reference to personal communication is Done 9, paragraph t, line 2 appropriate in this context. or whether it would be sufficient to note that the simplified scenarios were developed by the SSC project. 822. Section J.22, page J-The first sentence of the paragraph states that two complex Done 9, paragraph 1. line 4 scenarios were considered, but the list on this line contains three. including a Hosgri-Shoreline scenario that appears to be a splay scenario. Please check and make any appropriate corrections. 823. Section J.2.2, Page J-Please define the parameters "L" and "W" the first time they are Done 9, 1"' Paragraph, 6th used. Line 824. Section J.22, page J-The final sentence of the paragraph cites a personal communication Done 9, paragraph 1. last 2 for the approach to scaling the simulation parameters. Please rewrite lines this sentence to make it clearer that the Tl Team made the judgment to follow this approach. in light of its technical assessment of the alternatives and its consideration of the specific ways in which the simulations are used. 825. Section J.22, page J-Please add the missing word "that" in the phrase "except for." Done 9, 2n* of section, 2" line after equations 826. Section J.22, page J-Please clarify the intended meaning of the phrase "shortening a Done 9, 2" paragraph of fault". If, for example. it means shortening it relative to the length section, s'" and 6'" assigned in the SSC. that should be made explicit. Also clarify the lines after the intended meaning of the word "lowered" with respect to the northern equations endpoint [of the fault]. 827. Section J.2.2, page J-This sentence has several issues that should be corrected. ( 1) Done 10, 3'" paragraph of Please revise the awkward and ungrammatical (in this context) section (1" on page), construction "instead of attempting to predict realistic ground 1 sentence on page motion." (2) Please consider whether "realistic ground motion" is the right contrast to draw with "relative" ground motion (e.g., would "absolute" ground motion level be more appropriate?). (3) The caution against using the simulations for absolute ground motion levels appears to contradict the use of simulated ground motions in Chapter 8 to evaluate the common-form models Please rewrite this sentence to clarify the intended meaning and resolve the apparent contradiction. 828. Section J.2.2, page J-Later in this section, when splay scenarios are discussed, the Done 10. heading of 41" corresponding headings start with "Splay Scenario." The structure of paragraph of section the discussion would be more parallel and clearer if this heading (line 4 on page) were changed to "Complex Scenario 1: Hosgri-Los Osos." Please also include a section number for this and other similar subsection headings in the appendix, for easy reference and stylistic consistency with the other sections of the report. 829. Figure 2.2-1, Page J-Please show the surface projection of the inferred rupture plane of Done 10 the dipping reverse fault(s) in this and similar figures in the appendix. 830. Section J.2.2, page J-Please indicate (e.g., in the table caption) which (Hosgri or Los Done 10, Table J.2.2-1 Osos) is segment 1 and which is segment 2. 831. Section J.2.2, page J-Later in this section, when splay scenarios are discussed, the Done 11. heading at top of equivalent headings start with "Splay Scenario." The structure of the page discussion would be more parallel and clearer if this heading were changed to "Complex Scenario 2: Shoreline-San Luis Bay." 832. Section J.2.2, Page J-The length of the Shoreline fault plotted in this figure seems to be Done 11. Figure J.2.2-2 and much shorter than the length listed in Table J.2.2-2. Please check Table J2.2.-2 and revise as needed. 833. Section J.22, page J-Please indicate (e.g., in the table caption) which (Shoreline or San Done 11. Table J.2.2-2 Luis Bay) is segment 1 and which is segment 2. 834. Section J.2.3, page J-If the rupture scenarios were defined by the DCPP SSC Tl Team, Done 11. 1 ** paragraph, 1 *1 2 please indicate that explicitly. lines 835. Section J.2 3, page J-Please justify why the Tl Team made the judgment to select Text was added indicating that as validated the simulation 12. 211* paragraph of scenarios consistent with the Leonard relationships (e.g., is there a methods used source generators based on Leonard (2010), section (t'1 on page), connection with the way the models were validated?). and based on extensive discussions on the topics with lines 4 & 5 developers the Tl team made the judgment to select scenarios consistent with the Leonard relationships 836. Section J.2.3, page J-Please clarify which research goals were facilitated by the The research goal of how to mix GMPEs for complex and 12. 211* paragraph of modifications described and how the results ultimately feed into the splay cases was stated. section (t'1 on page), GMCmodel. Last 2 sentences of paragraph 837. Section J.2.3, page J-Please check whether the intended meaning would be better Done 12. 4'h paragraph of conveyed by using "each case" in place of "both cases." section, line 1 838. Section J.2 3, page J-Please explain the meaning of the phrase "scaled that slip by 30%," Done 12. 4'h paragraph of and give the justification for selecting the vaue 30% . section (3" on page), 3*d and sentences 839. Section J.2.3, page J-Please clarify whether "this slip" refers to the slip on the secondary Done 12. 4th paragraph of fault. section (3'" on page), 5*h line 840. Section J.2.3, page J-Please check whether this line should read "Los Osos-San Luis Bay Done 12. 5th paragraph of splay scenario" and correct if appropriate. section (3'* on page), Linet 841. Section J.2.3, page J-This sentence is confusing because of the ambiguity of the word Done 12. 5"' paragraph of "meet" in this context (i.e .. the word does not indicate which fault is section (3'" on page), cut off by the "meeting"). Please consider whether the intended Line 5 meaning would be better indicated if "meet" were replaced by "abut". 842. Section J.2.3, Page J-Please explain how exactly the process described in this sentence Done 13. 1st Paragraph. was done, which is somewhat confusing as stated. 2nd Sentence 843. Section J.2.3, page J-This sentence repeats nearly verbatim that of Section J.2.2, Page J-Done 13. paragraph 8 of 10, 3m paragraph of section. and the same comment applies and is section (41h on page) repeated here. This sentence has several issues that should be corrected. (1) Please revise the awkward and ungrammatical (in this context) construction "instead of a1tempting to predict realistic ground motion. (2) Please consider whether "realistic ground motion" is the right contrast to draw with "relative" ground motion (e.g., would "absolute" ground motion level be more appropriate?). (3) The caution against using the simulations for absolute ground motion levels appears to contradict the use of simulated ground motions in Chapter 8 to evaluate the common-form models Please rewrite this sentence to clarify the intended meaning and resolve the apparent contradiction. 844. Section J.2 3, page J-The phrase "Complex Scenario 2" should read "Splay Scenario 2". Done 14, heading following Table J.2.3-1 845. Section J.2.3, page J-"Shoreline-San Luis Bay splay" should read "Los Osos-San Luis Bay Done 14. 1 *1 line after the splay". Please correct. heading 846. Section J.3, Page J-Please indicate if "spectra" refers to Fourier amplitude spectra or Done 15, 1st Paragraph, 4th PSA spectra or both and whether the RotD50 component applies to Bullet Item, Last Line PSA here and elsewhere throughout the appendix. Nole a previous comment to use a consistent definition for the PSA spectral values referenced throughout the appendix and to define the term "RotD50" the first time it is used. 847. Section J.3.2, Page J-Please explain what an SRF file is the first time the term is used. Done 16,Second Paragraph, Line 3 (Item 2) 848. Section J.3 2, Page J-Please explain what each of the "two pieces" of the SRF file Done 16, 3rd Numbered represents. Item 849. Section J.3.2, page J-Please use some alternative language in place of the personal Done 16, paragraph 3 of pronoun "I" in order to better reflect the Tl Team's collective section ( 1 *1 paragraph intellectual ownership of the model and maintain stylistic consistency after the list), Line 2 throughout the report. 850. Section J.3.2, page J-The meaning of this sentence is not clear. Please rewrite it to clarify Done 16, S'h paragraph of how ExSim solutions for the component segments were combined. If section (last the GP and SDSU simulations were applied in some way as part of paragraph on page). the ExSim procedure, the explanation should clarify what "properties" 211* sentence GP and SDSU provided. and how those properties were matched by the ExSim procedure. 851. Section J.3.2, page J-The time delay appears to represent the delay between initial Done 16 51" paragraph of rupture on the initial segment and arrival of that rupture at the section (last on page). junction of the fault segments. If that is the case. the relevant velocity last sentence would be the rupture velocity, not the S wave velocity Vs. If this reasoning is correct, please modify the notation "Vs" to be more appropriate for representing a rupture velocity instead of the wavespeed If it is not, please clarify. In either event, please rewrite this sentence to be explicit about what was done. That is, instead of using the ambiguous qualifier "based off', state explicitly what was calculated to obtain the delay time. 852. Figure J.3.2-1, Page Please describe the meaning of the colored shading on these and Done J-17 similar plots in the appendix. 853. Section J.3.2, page J-The use of quotation marks on "factors" is not appropriate (it is not a Done 17. 6"' paragraph of meta-reference to the word "factors"), and because the quantities section (1"1 on page), defined here are used repeatedly in an important role in this section, line4 the clarity would be significantly improved if they were given a distinctive name, with the name then used consistently throughout the discussion that follows. 854. Section J.3.2, page J-The factors obtained from rules for defining GMPE input parameters Done 17. 6'" paragraph of appear to be different quantities than the factors defined earlier in the section (1'1 paragraph paragraph, and the use of the same term "factor" for both (especially on page), line 9 since the term "factor" is not distinctive to begin with) is a source of confusion. Please clarify the discussion later in the chapter by giving the ratios obtained from these GMPE rules a distinctive name, different from that used for the simulation ratios. 855. Section J.3.2, page J-The characterization of the process as "already quite convoluted" is Done 18, 7'h paragraph of redundant. Please consider deleting that phrase In fact, the entire section (1'1 on page), sentence could be replaced by beginning the subsequent sentence 1 sentence with "For complex scenarios with both a strike-slip and reverse component, it was required." 856. Section J.3.2, page J-Please elaborate on what "separated" means in this context and how Done 18, 7'h paragraph of this separation is conducted and the results verified section (1"1 on page), last sentence 857. Section J.3.2, page J-Please explain what this paragraph contributes to the description or Done 18. 8"' paragraph (2r.d evaluation of the GMC model or delete it. on page) 858. Figure J.3.3-1, Page Please define the acronyms used in the legend of the plot. Done J-19, Caption 859. Section J.3.3, page J-This sentence is similar to that of Section J.3.2, Page J-16 5'" Done 20. 3rd paragraph of paragraph of section (last on page), last sentence. and the same section (1"1 on page), comment is repeated here. The time delay appears to represent the line 6 delay between initial rupture on the initial segment and arrival of that rupture at the junction of the fault segments. If that is the case, the relevant velocity would be the rupture velocity, not the S wave velocity Vs. If this reasoning is correct. please modify the notation "Vs" to be more appropriate for representing a rupture velocity instead of the wavespeed. If it is not, please clarify. In either event, please rewrite this sentence to be explicit about what was done That is, instead of using the ambiguous qualifier "based off', state explicitly what was calculated to obtain the delay time. 860. Section J.3.3, page J-Please remove the inappropriate quotes from "factors" (but see Done 21. 4'" paragraph of previous comment recommending use of a more distinctive section (t'1 on page), terminology), and correct the redundancy in the phrase "we 1" and z*d lines on computed factors computed for." oaae 861. Section J.3 2, Page J-If "plant site" refers to the "DCPP site". please replace the former Done 2t. 1st Paragraph. with the latter. If the intended meaning of the phrase is different, 2nd Line please supply the intended meaning. 862. Section J.4, Page J-Please avoid the use of the term "proponent models" here and Done 21. Section Heading elsewhere throughout the appendix. which can be confused with the term proponent models and/or methods proposed by Proponent Experts, as defined in the SSHAC guidelines. 863. Section J.4, Page J-Since much of the text in this section is virtually the same as the text Done 21, General in Section 6.7, please refer to the comments on Section 6.7 for revising the similar text and figure captions in this section. 864. Section J.4, Page J-Please clarify whether this always leads to an increase in ground Done 22. 211* Paragraph of motion. section, Line 2 865. Section J.4.1, page J-Please consider whether the intent of this line would be better Done 23. 1 paragraph, line conveyed by the phrase "Four methods were evaluated for 1 computing" in place of the phrase "four methods were used to comoute." 866. Section J.4 1, page J-Please define the variables used in the equation. and. for Done 23, 2"' paragraph of consistency with other parts of the report, change "Sa" to "PSA." section, unnumbered equation 867. Section J.4.1, page J-The quotation marks on "average" are inappropriate. If the word Done 23. znc paragraph of "average" without quotes doesn't communicate the intended section, 3'" line after meaning. please use a word that does (e.g., "representative"). the equation 868. Section J.4.1, page J-24. 4'" paragraph of section (t'1 on page), Please define the variable "R." Done line 2 869. Section J.4.1, page J-Please define the variables used in the equation and clarify the Done 24, 4*h paragraph of nature of the summation. section ( 1 *1 on page), unnumbered equation 870. Section J.4.1, page J-Please consider whether the intent of this sentence would be better Done 24. 1 line after the conveyed by the phrase "The GMPEs are then applied using" equation instead of the phrase "The GMPEs use the", since the latter could be misinterpreted to imply that the subsequent part of the sentence is a defining feature of the GMPEs. 871. Section J.41, page J-The meaning of this line would be clearer if the sentence began by Done 24, last paragraph of indicating explicitly that the method applies the GMPEs with the section, 1*1 line predictor variables as defined in the balance of the sentence. Please clarifv this line. 872. Section J.42, Page J-Please revise the sentence so that it is clear that "50 degree" refers Done 24. 2"" paragraph of to the fault dip. section, line 1 873. Section J.4.2, page J-Please specify that "method refers to "ground motion simulation Done 25, paragraph 4 of method." The distinction is necessary because four methods for section (last on page). assigning GMPE predictors are also discussed and need to be line 1 differentiated from the numerical ground motion simulation methods. 874. Section J.4.2, page J-Please clarify this line by specifying that the spectra are obtained Done 25, paragraph 4 of from the GMPEs using each of the four different methods for section (last on page), assigning predictor variables. line 2 875. Figure J.4.2-1, Page Please correct the acronyms in the plot legends to confolTl'l with Done J-26 those used elsewhere throughout the report and appendices (i.e., "ASK14" instead of "ASK'13). Also, please check the accuracy of the "grey" curve that has a nearly "flat" zone from 0.5 to 1 Hz and. if correct. explain why this GMPE is used given such strange behavior. 876. Section J.4.2, page J-There are no gray lines in Figure J.4.2-3, nor are the colors of the Done 26. paragraph 5 of section (1"1 on page), dots explained. Please correct. line 2 877. Section J.4 2, page J-As noted in an earlier comment, the discussion of complex and splay Done 26, paragraph 5 of adjustments would be easier to follow if the simulation factors and section (t'1 on page), GMPE factors had different, distinctive names used consistently line 2 throughout the chapter. Furthermore, the GMPE factors have not been explicitly defined, and although the meaning can be inferred from the context pretty well, it would be clearer if they were explicitly defined when the concept was first introduced. Please consider introducing better terminology and more explicit definitions for these "factors". 878. Section J.4.2, page J-Figure J.4.2-3 does not appear to show what is claimed, maybe Done 26. paragraph 6 of because the gray lines mentioned in the text and caption are not section (2"d on page). visible. line 2 879. Figure J.4.2-3, Page There are four GMPE methods but six differently colored dots. Done J-28 Please indicate what the different colored dots represent both here and in similar plots in the appendix. 880. Section J.4.2, page J-The statement that the magnitude is based only on the area of the Done 29. 9"' paragraph of Los Osos fault in Method 1 for the Hosgri-Los Osos scenario is section (1"1 on page), confusing. The problem is that the statement can be misinterpreted last sentence to suggest that the magnitude of the scenario changes depending upon the method of ground motion calculation. However, what actually changes is just the predictor variable M that is input to the GMPE. Please keep this distinction clear in the discussion. 881. Section J.4.2, page J-Please revise this sentence so that it is clear "70 degree" refers to Done 29, 10'" paragraph of the fault dip section (2"d on page). Line 1 882. Section J.4.2, page J-This figure citation appears to be in error. as this is no Figure J.2.2-Done 29, 10'" paragraph of 3. Please check whether the citation should be to Figure J.2.2-2 and section (2"d on page). make the appropriate correction. Line 2 883. Section J.4.2, page J-Please check whether the cited table should be J.2.2-2 instead of Done 29. 10111 paragraph of J.2.2-3. section (2"d on page). Line 3 884. Section J.4.2, page J-The word "one" just before the comma is ambiguous. Please clarify Done 29, 11'" paragraph of whether the meaning is "all periods except for one period" (in which section (last on page), case indicate which one), or if ii is "all periods except for T= 1 last line on page second." 885. Section J.4.2, page J-The gray lines are not visible in Figure J.4.2-6, nor are the symbols Done 30. 13111 paragraph of explained. Please correct this. section (2"d on page). Line 1 886. Section J.4 2, Page J-If this sentence is intended to refer only to Methods 2. 3, and 4, but Done 32, 2nd Paragraph, not Method 1, please replace the phrase "each of these methods Last Sentence with "each of Methods 2, 3, and 4." 887. Section J.4 2, Page J-Please expand this paragraph to summarize quantitatively the Done 33. 1st Paragraph on justification for accepting Method 1 for the complex scenarios. page, 1st Sentence 888. Section J.4.3, page J-Please cite a published report or journal article for the observation Issue resolved in Rev.2 34. 4'" paragraph of that the GMPEs have stronger distance saturation than the ExSim section (1'1 on page), model. Then the result mentioned here (regarding ExSim peak line 5 amplitudes) can be stated as a consequence of that fact (perhaps one pointed out by Dr. Atkinson to the Tl Team), rather than something to be taken purely on the authority of an unpublished comment by Dr. Atkinson. 889. Section J.4.3, Page J-Please reference the figure where the comparison referred to in this Done 35, 2nd Paragraph on sentence is shown. page, 1st Line 890. Section J.4.3, Page J-Please explain quantitatively the basis for the statement that Done 37. 2nd Paragraph on "Overall, GMPE Method 1 RotD50 spectra provide the best page, Last Sentence agreement with the simulation results". 891. Section J.4.3, page J-Please reference the figure where the comparison referred to in this Done 39. 1 paragraph on sentence is shown. page, 1*1 line 892. Section J.4.3, page J-In Figure J.4.3-6, the colors are not explained nor are the panels Done 39, 1" paragraph on labeled nor explained in the caption Please correct this. page, last line 893. Section J.5.1, Page J-The magnitude ranges specified in this sentence disagree with those The magnitude ranges have been corrected. Simulations 41. Last Sentence of specified elsewhere in the report and also disagree with those were used to a minim um magnitude of 6.0. ASK 14 and section described in the publications of ASK14 and CB14 Please revise as CB14 both use magnitude tapers from M<6 5, which tapers needed. to no effect for M <= 5.5. 894. Section J.5.2, Page J-Please clarify that only the NGA-West2 HW terms are used and that Yes this is true 41, 3rd Paragraph of these terms are applied to the footwall model developed from the Section, 1st Line simulations. 895. Section J.5.2, page J-Please distinguish whether the processing described in this Clarified that the processing was on the simulation PSA. 41. 3'0 paragraph of sentence refers to the GMPE estimates or the simulation estimates. section, 2"d sentence Also clarify that the phrase "extent of the rupture plane" means extent of the surface projection of the rupture plane. 896. Section J.5 2, page J-Please either provide the functional form used or a reference to the An equation was added. 41. 3'" paragraph of report section or publica1ion where it is provided. section, 3'" sentence 897. Section J.5.2, Page J-Instead of stating that the comparisons are similar, please include Since this figure is just demonstrating that we can reproduce 41. 3rd Paragraph of the comparisons with CB14 and CY14 on Figure J.5.2-2 to show the the GMPE with the approach used to analyze the simulated Section, Last robustness of the NGA-West2 GMPE HW terms. motions it is not really necessary to show all of the model-to-Sentence model comparisons. Instead we removed the sentence regarding CB14 and CY14. 898. Section J.52, Page J-The SDSU simulations do not show a HW effect at M5.5 and M6.0. Text has been added discussing that while it is true the 41. 4th Paragraph of This would imply 1hat there is some uncertainty in whether there is a SDSU method shows lower HW amplification for the shown Section, 2nd HW effect at small magnitudes. Please discuss how this uncertainty scenario, other fault dip and ztor cases indicate that HW Sentence is factored into the HW model or reference where in the report such amplification is seen in all three simulation methods. a discussion is provided. 899. Section J.5.2.3. Page Instead of stating that the results are similar, please include the Figure J.5.2-4 was added to shows the comparison between J-42. 1st Paragraph. results from CB 14 to show that the results are similar. CB14 and the simulations 2nd Sentence 900. Section J.5 2, page J-The statement that the distance taper is small is ambiguous and Poor choice of words. Small was referring to the lack of 42, 5*h paragraph of confusing. It appears, in fact, that the distance tapering factor is near tapering, but as you point out that term is in fact larger section (2"" on page). unity, not near zero. Please clarify. valued. The text has been clarified. znc lo last sentence 901. Section J.5.2.3, Page Please also clarify that the development of the HW term for the GMC The development of the HW model has been now moved to J-42. 3rd Paragraph, model is given in Appendix K Chapter6 Last Sentence 902. Section J.5.2, page J-Please reconsider the categorical statement made here that the M The statement regarding the severity of the magnitude 42. 6'h paragraph of taper of the NGA-West2 GMPEs is too severe. There are several tapers was removed and the focus changed to reiterating section (3'c on page), such GMPEs. Do you mean to refer to all of them, to all that use that the simulations show that hanging wall effects may be 2"" sentence Rrup as the distance predictor, or to just ASK 14 and CB 14? Why important to magnitude as low as 5.5 would CY14 be judged as too severely tapered, given the results in Figure J.5.2-4? Please clarify. 903. Figure J.5.2-2, Page Please expand this figure caption to better describe the plots that The caption has been expanded. J-44 are shown in the figure. 904. Figure J.5.2-3, Page Please indicate that the colors refer to the plus symbols shown on Done J-44 this and similar plots in the appendix. 905. Section J.6.1, page J-The language used here could imply that 1 D models are not yet fully The sentence has been changed stating that Green's 47. 1*1 paragraph of implemented. Please clarify by revising this line functions for 1D models are being used by the BBP. section, line 1 906. Section J.6.1, Page J-Stochastic simulation methods often employ a set of site-Text has been added clarifying the velocity model 47. 1st Paragraph, 4th amplification factors that are developed from a 1D velocity and constraints on the BBP methods. A minimum Vs=863 mis is Sentence density crustal structure, typically using the Quarter-Wavelength used EXSIM does use calibrated geometrical spreading and Method. Please clarify whether or not that is the case with the attenuation operators. As implemented the methods are versions of EXSIM, G&P and SDSU that are available on the BBP, simulating rock motions and they are not subsequently all of which use a stochastic method (though only for the adjusted for site effects. computation of ground motion at frequencies above 1 Hz in the case of SDSU and G&P). If it is. please indicate what crustal structure is used and how similar it is to the velocity models described in this section. 907. Section J.61, Page J-Please indicate the referenced features on the velocity profiles Done 47, 2nd Paragraph, shown in Figure J.6.1-1. 1st and 2nd Numbered Items 908. Section J.6.1, page J-Please indicate whether the recording at PKD was affected by any Done 47. 3*d paragraph of significant, known 3D wave propagation effects. section, line 2 909. Section J.6.1, Page J-Please provide units for the values 286, 93, and 62. Done 47. 3rd Paragraph. 3rd Line 910. Section J.61, page J-The cited figure shows synthetic ground motion, not velocity models, Done 47, 3'" paragraph of so "GIL7 velocity model" should read "synthetics calculated with the section, line 7 1D GIL? velocity model." 911. Section J.6.1, page J-Please provide a reference (either to a publication or to a report Done 47. 3*d paragraph of section) supporting the asserted appropriateness of the GIL7 velocity section, line 8 model for the central coast ranges. 912. Section J.61, Page J-Please define the term "PL type wave" the first time it is used, or cite Deleted since this level of detail is not needed. Long-period 48, 1st Paragraph on a reference where the term is defined. P-wave suffices. page, 2nd Sentence 913. Section J.61, page J-This paragraph (and to some extent the preceding one as well) Fair comment GIL7 is considered more appropriate for two 48. 211* paragraph on seems rather awkward and its purpose unclear. The discussion reasons: 1) it is based on modeling of seismic waveforms page appears to be treating GIL7-based synthetics as targets for the BBP and not just P-wave arrival times, thus it includes direct Norcal-based simulations to match, giving the GIL7-based synthetics information regarding shear wave velocities, and 2) it is now similar status to that of the observed waveforms. Why would not all commonly used by the BSL in routine analysis. which has of the models deserve comparison with the observations on an equal proven effective in source parameter recovery. footing? Please consider whether it would be less confusing, and Nevertheless, the suggested rephrasing more clearly makes more to the point, to simply state that, on balance, simulated in the intended point and the text has been modified. waveforms based on the BBP Norcal profile agree with the key features of the observed waveforms at least as well as those based on alternative available 1 D models. 914. Section J.6.1, Page J-Please avoid the use of the subjective term "very good agreement Done 48. 2nd Paragraph, and instead provide a quantitative measure of the agreement and 4th Line why that measure of agreement is acceptable. For example, it appears from Figure J.6.1-3 that the synthetic seismogram amplitudes are as much as a factor of 2 higher than the observations. 915. Section J.6.1, page J-The clause beginning with "although" confuses the issue, making it The point that the use of the 1 D velocity model in the 48. 3'd paragraph on harder to understand the point being made. The use of the 1 D model simulations is justified is made clearer. Future page, 1*1 sentence is either justified by the tests cited or it is not. The fact that there improvements in methods including 3D structures will likely could be an even better option for future use is interesting and worth improve the simulations, but that issue is not immediately mentioning as a final comment, but it does not address the question relevant to this report and has been deleted. of whether the current use of the 1 D models is justified. Please rewrite this sentence to summarize the Tl Team evaluation of the model actually being applied. Ideas (like 3D modeling) for future improvement may be offered, but in a way that makes it clear that the evaluation is not contingent on those improvements. 916. Section J.6 2, page J-Please provide a specific reference to the discussion or presentation Done 50, 1" paragraph of where the stated "remark" from Workshop 2 can be found, and section, line 1 indicate the period range implied by "long-period" in this context. 917. Section J.62, Page J-Please clarify if the comparison is between simulated ground The comparison is between simulated motions and fault slip 50, 1st Paragraph, motions or between simulated and observed ground motions. only. There is no comparison with observations. 2nd Sentence 918. Section J.6 2, page J-The line described parenthetically as red appears as a black line in Corrected 50, 1" paragraph of Figure J.6.2-1. Please correct this description so that the text and section, line 7 figure are consistent. 919. Section J.6.2, page J-Please clarify that the comparison is between simulated ground This is the correct interpretation, and the text has been 51. 3rd paragraph of motion and synthetic slip models used to compute those ground clarified. section (2"" on page) motions, if that is the case. If that is not the correct interpretation, please explain. 920. Section J.62, page J-51, 3'" paragraph of section (2"" on page), Please explain what the word "maximum" refers to. Done Line 2 921. Section J.6.2, page J-This paragraph and some of the subsequent discussion is difficult to The first paragraph has been rewritten to clarify the 51, 4th paragraph of follow. Please consider prefacing ii with some clear statement of the motivation of the section. section (3'" on page) purpose of the analysis, and following it with a clear summary statement. For example, if the purpose is to assess (using numerical simulations) whether near-fault. long-period ground motion amplitudes mirror the empirically-observed high variability of static slip values. ii would help if that were stated explicitly. If the conclusion is that ground motions do not mirror that high variability, because they are better correlated with broader spatial averages of slip (which are less variable than point values) than they are with nearest-point slip values, it would be useful to summarize that conclusion in explicit terms. 922. Section J.6 2, page J-Please consider whether the intended meaning of this line would be Done 51, 4*h paragraph of clearer if the phrase "from nearby shallow regions of the fault" were section (3'c on page), restated as "from slip on shallow portions of the fault that are nearby. line 3 but not necessarily nearest. to the site," or some similar phrase that highlights the essential idea that the nearest point on the fault does not necessarily dominate the ground motion amplitude. 923. Section J.6.2, Page J-Please explain the meaning of the term "radiation sensitivity" and Done 51. 3rd Paragraph on define the tenns "FP" and FN" the first lime they are used. page, 7th Line 924. Section J.6.2, Page J-Please clarify that the "given site is the location of LCN. Done. This was meant to be general so the phrase ". in this 51, 3rd Paragraph on case LCN" was added. page, Last 2 Lines 925. Section J.6.2, page J-This paragraph is difficult to parse and its purpose is not very clear. Changed to added. The point is that in the validation LCN is 51. 511' paragraph of Please rewrite to make that purpose clearer, and also please state an actual stations that was used where we have simulation section (4111 on page). what is meant by the phrase "pseudo station." results, and the other 13 are simply used to compare different measures of the slip model to document both along strike, and source realization variability in slip. 926. Section J.6.2, page J-Please include plots of variation of static displacement, peak FP and Done. Also the plots for radiation pattern averaged slip were 51, 7'h paragraph of FN displacement, and SD with the nearest surface slip incorporated in a new composite figure J.6.2-5 and the section (61h on page), original figures J.6.2-5 -7 have been deleted. Line 1 927. Section J.6.2, Page J-Please clarify what "correlations" are being referred to in this We added "simulated" to clarify that the comparisons or 51, 6th Paragraph on statement. correlations are between the simulated ground motions and page, 3rd Line the various measures of fault slip. 928. Section J.6.2, Page J-Please avoid the use of the subjective statement quite good" and See answer below 51, 6th Paragraph on page, 5'h line replace it with a quantitative measure of the goodness. 929. Section J.6.2, page J-This sentence is ambiguous. One possible interpretation is that the Section and sentence has been rewritten 51, 7'h paragraph of static displacement and FP peak displacement correlate better with section (6'h on page). local fault slip than does the FN peak displacement. An alternative 3*d sentence interpretation is to replace "than does" with "than with". Please make changes to resolve this ambiguity. 930. Section J.6.2, page J-There is a reference here to "local fault slip." Please distinguish. Done 51. 7111 paragraph of here and elsewhere in this section. between point-wise (or nearest-section (6111 on page). point) values of local fault slip versus localized averages. The last line on page distinction is important because there is no real question that some sort of local average is going to correlate with low-frequency ground motion. The point of the section appears to be to indicate just how localized that control is, and therefore how much variability it introduces. 931. Section J.6.2, Page J-Please clarify what the "geometric mean" is taken with respect to. Done 60. 1st Paragraph on page, 1st Line 932. Section J.6.2, Page J-Please delete the subjective word well". Done 60, 1st Paragraph on page, 4th Line 933. Section J.6.2, Page J-Please complete the phrase "and that the range of the simulated Done. " ... motions spans that of the individual GMPEs." 60. 1st Paragraph on motions". page, Last Line 934. Section J.6.2, page J-Please resolve the ambiguity of the phrase "10s of source Done 60. B"' paragraph of realizations," which can be read as "1 O's of source realizations" or section (1"1 on page), "10 seconds of source realizations." last line on page 935. Section J.6.2, Page J-Please explain why the capture of the variability along the fault by Expectation is not the right word. The analysis shows that 61, 2nd Paragraph, the 50 realizations is expected. this is the case and the text has been modified to make that Last Sentence point 936. Section J.7, page J-Please ensure that all of the references that are cited are in the list Done 61 & J-62 of references and that all of the references are complete with up-to-date infonmation. For example, please update reference items 2. 8, 10 & 13 with complete publication information, and the missing references for Goulet et al. (2014) and Dreger et al. (2014) that were cited at the end of Section J. 1. 1. 937. Figure J.2.2-2, page Please add to the caption that "Shoreline" and "San Luis Bay" label Done J-1 t the rupture segments modeled in the simulation, and indicate their relationships to the Shoreline Fault and San Luis Bay Faull, respectively (e.g .. that they are simplified representations inspired by the Hosgri-Shoreline splay scenario?). 938. Figure J.4.2-2, Page Please add a label to the y-axis and indicate in the figure caption y-axis label provided J-26 that this figure is for complex rupture Scenario 1. This request also applies to Figures J.4.2-5, J.4.3-2, and J.4.3-5 939. Figure J.4.2-3, page The gray lines in this plot are not visible, and the meanings of the Done J-28 colors are not indicated (the latter also applies to Figure J.4.2-6, J.4.3-3, and J.4.3-6). Please correct. 940. Figure J.4.2-6, page The gray lines in this plot are not visible, and meanings of the colors Done J-32 are not explained. Please correct. 941. Figure J.5.2-3 & These figures use a different color scheme for the 3 simulations than Done Figure J.5.2-4, pages do earlier figures, which is confusing. Please use the same color J-45 & J-46 scheme for all figures for clarity. 942. Figure J.4.3-2, page Please label the plot axes. Done J-35; Figure J.4.3-5, Page J-39; and Figure J.6.1-1, page J-48 943. Figures J.6.1-2 and Please indicate the recording station in the caption. Done J.6.1-3 944. Figures J.6.2-5 Please explain the use of the factor Y:., and why it is absent in Done. These figures have been incorporated into the new Figures J.6.2-6 and J.6.2-7. Also please define the symbols and lines composite Figure J.6.2-5. in the plot and reword the caption to be more meaningful in this and similar figures in the appendix. APPENDIX K Hanging Wall Model 945. General There are many parameters, terms, and acronyms used throughout The appendix is now integrated into the Chapter 6, so the appendix without first being defined As a reiteration of previous several of the acronyms are defined already comments on various chapters and appendices in this report. please ensure that all of the parameters, terms, and acronyms used in this appendix are defined in a list prior to their use. Otherwise, they will need to be defined the first time they are used in each chapter and appendix. 946. General All of the figure captions are short and cryptic. Please expand the Done figure captions to completely describe all of the curves shown on the plot and the values of any variables that were used to plot them. 947. Section K.1, Page K-Please explain the meaning of the term "HW factor" the first time it is Done 1, 1st Paragraph of used (e.g., indicate how is it calculated from each GMPE). Please Section, 1st Line also indicate who derived the HW factor model in place of the statement "The HW factor model was derived". 948. Page K-1, First Please include a brief summary of the ranges of magnitude and Ztor Paragraph and site locations (Rx) for which HW effects are of importance to the GMCmodel. 949. Section K.1, Page K-The dip of the rupture plane is a fifth aspect of the ASK14 and CB14 Done 1, 1st Paragraph of HW terms that has been overlooked. Please mention the dip of the Section, 2nd Line rupture plane as an additional aspect of the ASK 14 and CB 14 HW terms. 950. Section K.1, page K-Please replace "rupture place" with "rupture plane." or, perhaps Done 1, 1 "' paragraph. line 3 more precisely, with "rupture surface." 951. Section K.1, Page K-Please define the term "taper," as it applies in this context, the first Done 1, 1st Paragraph of time it is used. Section, 5th Line 952. Section K.1, Page K-Please indicate which of the five aspects of the HW terms of ASK14 Done 1, 1st Paragraph of and CB14 are also present in the CY14 HW term before describing Section, 7th Line the differences in this latter term. 953. Section K.1, Page K-Please insert the missing comma after the word "magnitude" al the Done 1, 1" Paragraph, Line end of line 7. 7 954. Section K 11. Page Please avoid the use oflhe subjective term "significant" and instead K-1, 1st Paragraph of provide a quantitative metric to describe these differences. Please Section, 6th Sentence also summarize the observed differences among the HW terms of the NGA-West2 GMPEs 955. Section K 11. Page Please indicate ifthe HW factors given by Eq. (K-1) are arithmetic or Done K-1, Eq. (K-1) logarithmic and exercise care when referring to this factor elsewhere throughout the appendix by indicating if it is the multiplicative factor or the log factor that is being referenced. 956. Section K.1.1, Page Please justify the assumption that the HW effect is largely geometric Discussion added in Chapter 6 K-2, 1st Paragraph on and show why, based on this assumption, that the surface projection page, 2nd Sentence of the rupture plane is directly related to the cosine of the dip. 957. Section K 11. page Please add a comment noting that the formulation alluded to was That's not correct. K-2, 1 "1 paragraph of introduced to fit numerical simulations, if that is the case. section (t" on page), 3*d sentence on page 958. Section K. 1.1, Page Please briefly describe the HW study and model developed by Out of the SWUS GMC scope K-2, 1st Paragraph, Donahue and Abrahamson (2014). 5th Line 959. Section K 11. page Please clarify the purpose of the expression "with the effect based Entire section absorbed in Chapter 6, with greater K-2, 1 "1 paragraph of on the GMPE." It seems to be covered already by the text in the consistency among all the parts section (1" on page), beginning of this sentence. Line 7 960. Section K.1.1, page Please justify the Tl Team's decision to neglect HW effects at Based on GMPEs scale K-2, 1" paragraph of periods longer than 3 seconds, in light of the interpretation of Chang section (1"' on page), et al. (2004, BSSA, vol 94, p. 2186) that there are large HW effects 2"" to last sentence at long period (T = 2s and 4s) for the 1999 Chi Chi earthquake. This may entail showing plots of long-period (T>3s) residuals for the ChiChi earthquake computed with respect to the candidate GMPEs. 961. Section K. 1.1, Page Please define the meaning of "central model" (e.g., is it the median Clarification added in Chapter 6, in the appropriate section K-2, 1st Paragraph on or mean HW factor. which depends on whether the model is on the page, 12th Line factor itself or the log of the factor). 962. Section K. 1.1, page Please check whether this line should say "K-1 through K-4," and Based on GMPEs scale K-2, 1" paragraph of section (1"' on page), correct if appropriate. last line 963. Section K 11. Page Please define the term "base moder the first time it is used. Done in Chapter 6, where Appendix K was integrated K-2, 2nd Paragraph, 1st Line 964. Section K 11. Page Please further explain (here or preferably in Chapter 6) the necessity Explanation added (so we can randomly pick one HW K-2, Second for equal-probability sampling of the HW factor models, in lieu of branch) Paragraph of section other variance-preserving sampling schemes (un-equally weighted) (and 2"C on page) such as those widely used to represent the epistemic uncertainty of other PSHA inputs. 965. Section K 11. Page Please clarify whether it is the arithmetic HW factor or the log HW Clarification added in Chapter 6, in the appropriate section K-2, 2nd Paragraph. factor that is assumed to be normally distributed. 3rd Line 966. Section K.1.1, Page Please explain the meaning of "fitted model" Explained in chapter 6 K-2, 2nd Paragraph, 5th Line 967. Section K 11. page Please define the term "epsilon" the first time it is used. Done K-2, 2"d paragraph of section and page, line 7 968. Section K 11. Page Please explain how the "probability weighted mean epsilons" were Done K-2, 2nd Paragraph. calculated. 7th Line 969. Section K. 1.1, Page Please explain why "equally weighted factors" were used when they Done K-2, 2nd Paragraph. were derived from different probability ranges of a normal 12th Line distribution. 970. Section K. 1.1, page Please check whether this sentence should say "K-1 through K-4, Done K-2, 2"0 paragraph of section (2"d on page). and correct if necessary. 211* to last sentence 971. Section K.1.1, Page Please avoid the use of the subjective term "good" and provide a Explained in chapter 6 K-2, 2nd Paragraph, quantitative metric for describing the goodness of the observed 14th Line comparison. This applies to this instance and several other instances throughout the appendix where "good" is used to describe the goodness of a comparison. 972. Section K.1.1, Page Please explain why it is acceptable for some of the GMPE HW Explained in chapter 6 K-2, 2nd Paragraph, factors to fall outside the bounds of the five proposed HW models. 14th Line 973. Section K. 1.2, Page Please summarize the analysis from Appendix J to the extent Explained in chapter 6 K-2 necessary to form a readable and understandable review of the Tl Team's treatment of the magnitude taper issue. If, in that treatment. the magnitude-dependence carried implicitly by Eq K-1 is deemed reasonable based on the good agreement with simulated HW effects at M 5.5, please state this explicitly. 974. Section K 1 2. Page Other reasons why the ASK14 and CB14 HW models applied a Done K-2, 1st Paragraph of magnitude taper to make the HW factor go to zero at M5.5 was the Section, 2nd Line lack of any empirical data or numerical simulations to support a HW effect at smaller magnitudes. Please include these reasons in support the NGA-West2 developers "judgment" that is stated as the reason for the taper. 975. Section K.1.2, page Please give a specific magnitude range for the phrase "moderate Done (chapter 6) K-2, 1 paragraph, magnitudes". Line 3 976. Section K 1 2. Page The ground motion simulations described in Appendix J showed that K-2, 1st Paragraph of one of the three simulation models (SDSU) did not predict strong HW Section, 2nd effects at small magnitudes. except at relatively small depths (e.g., Sentence Ztor = 2 5 km) or relatively small dips (e.g .. dip= 30 degrees). Please indicate how this uncertainty is incorporated in the HW factor model presented in this appendix. 977. Section K.1.3, page Please indicate that the site angles of 90 and 0 degrees mentioned Done K-3, 3"' and 4*h in these sentences are measured relative to fault strike. sentences of section 978. Section K.1 3. page Please explain how the assertion that CB14 and CY14 "allow for a Figure corrected, and discussion modified accordingly K-3, lines 4-6 on page smoother transition as a function of location around the rupture" is consistent with the fact that (according to Figure K-5) CB14 has a step as Rjb approaches zero along the strike direction This step behavior actually appears to be a sharper transition than that of any of the other HW models in Figure K-5, and would seem inconsistent with this assertion. 979. Section K.1.3, Page Please avoid the use of the subjective term "well," which in this case Explained in chapter 6 K-3, 1st Paragraph, can be deleted without impacting the statement. 6th Line 980. Section K.1.3, Page Please indicate that the proposed Rjb taper model given by Eq. (K-Done K-3, 1st Paragraph, 2) is shown in Figure K-5. Eq. (K-2) 981. Section K.1.4, Page Please avoid the use of the subjective term "significant" and instead Explained in chapter 6 K-3, 1st Paragraph of provide a quantitative metric to describe the observed differences in Section, 3rd Line the trends. 982. Section K.1.4, Page Please indicate that the proposed Ztor taper model given by Eq. (K-Done K-3, 1st Paragraph of 3) is shown in Figure K-6. Please also show the equation for the Section, Eq (K-3) complete HW factor model that combines all three equations for completeness (also note whether the complete model is the arithmetic or log value of the HW factor 983. Section K 2, page K-Please provide a specific reference to the section(s) of Appendix J Not needed anymore because Appendix K was incorporated 3, 1 "' paragraph of where the hanging wall analysis is presented. in the main report section, 1"' sentence 984. Section K.2, Page K-Please provide and discuss the development of the equation that Done 3, 1st Paragraph of was used to define the footwall simulations. Section, 3rd Line 985. Section K.2, Page K-Please clarify who did the simulations described as "were Done 3, 1st Paragraph of simulated". Section, 5th Sentence 986. Section K.2, Page K-Please provide similar plots to those in Figure (K-1 t) for a range of Three new figures were added to show Ztor and dip 4, 1st Paragraph, 2nd magnitudes, dips, and depths to fully document the comparison with sensitivity for the M 5.5 and MG.O cases. The original figures Sentence the simulations, or revise Figures (K-1) to (K-10) to show all five HW in Appendix Kare now in Chapter 6 factor models instead of only the central model. 987. Section K 2, Page K-4 Please ensure that all of the references cited in the text are included Done in the list of references and that all of the references provide a complete description of the publication (e.g., volume and page numbers). 988. Table K-1. Page K-4 Please include all five of the C1 values that represent the five HW Done (Chapter 6) factor models in Table K-1. 989. Table K-1, Page K-4 The "Central" and "Range of Models" shown in this figure have not Done been discussed the first time this figure is referenced in the text. Please provide an explanation of these curves as well as an explanation that the curves and GMPE estimates are for Ztor = 0 in the figure caption of this figure and in Figures (K-2) through (K-4). 990. Figures K-t. K-2, K-3, Please make changes to the legend to reflect that the dashed lines Done and K-4 do not show the "range" of the models, but rather are the five individual models used to approximate the distribution of the modeled HW factors 991. Figure K-5, Page K-Please check the CB14 HW factor for the increasing Ry curve, which Figure fixed 10 for Rx = 0 should have a positive HW factor that decays with distance (i.e., it is only for Rx< 0 that CB14 predicts no HW effects). 992. Figures K-5 and K-6 Please change "rx" in the figure legend to "Rx" to be consistent with Done the main text. 993. Figure K-7 Please explain in the caption the meaning of the solid black curve in Done each plot and provide references to the three simulation models that are defined by their acronyms in this and similar figures in the appendix. Please also indicate that the SWUS HW tenn (called HW factor model in the text) that is plotted in this and all similar figures as the red line is the central model. APPENDIX 0 Comparison of Hazard: Original GMPEs versus Common Functional Forms 994. General Although the plots shown in this appendix show that the range of Plots added hazard is captured, it would be useful to show a comparison of the hazard curves from the GMPEs with the 5th, 50th. and 95th percentile hazard curves from the common-form models in order to also show that the body and not just the range of the hazard is also captured. Please provide such plots in addition to those that are already shown for the DCPP and PVNGS models. 995. Section 0. 1. page 0-The reference to a simplified" seismic source model is confusing. Chapter 14 was modified to indicate a simplified SSC model 1, 2M of This sentence refers to it as the DCPP SSC model used in Chapter is used for DCPP. This resolves the inconsistency. No section, 2° sentence 14, and the First Paragraph on Page 14-1 states that "the previously change to Appendix 0 text. published Seismic Source Characterization (SSC) models for the two sites were used", without reference to any simplification. Please review and revise the entire paragraph as needed to clarify. 996. Section 0.1, page 0-Without a comma after the words "closest sources, this sentence is Done 1, 2r.d of (almost) ambiguous as written. It could mean that the source model section, 2" sentence comprises the closest sources, inasmuch as those are the significant contributors. But it could easily be misread to mean that, among all sources that are significant contributors. the model singles out only the closest ones. If the former interpretation is intended, please clarify that by means of a comma. 997. Section 0.2. General Except for the addition of the hazard curve from GK 14, Section 0.2 Appendix 0 was modified to show additional periods and appears to provide the same information as provided in Section 8.4.3 fractiles (and Figures 8.4-17 and 8.4-18). Please clarify what is new in Section 0.2, compared to Section 8.4.3. 998. Section 0.2. Page 0-Please see comments given in other chapters and appendices Akkar's references fixed 1, 1st Paragraph of regarding suggested revisions to the bullet list of references to these Section, 3rd Line eight GMPEs. 999. Section 0.2. Page 0-Please provide the reference to sections of the report where the Done 2, 2r.d paragraph on common-form models are described. page ( t sentence after the bulleted list) 1000 Section 0.2. Page 0-Please indicate who calculated the common-fonn model hazard Done 2, 3rd Paragraph, 1st curves (i.e., the Tl Team, a hazard analyst, etc.) and the hazard Line code that was used. 1001. Section 0.2. Page 0-Please describe in more detail the modification that was made to the Clarification added 2, 3rd Paragraph, 5th ASK14 model. Line 1002 Section 0.2. page 0-Similar to the earlier comment, a comma after the words "hanging-Sentence has been rewritten 2, zn* paragraph of wall model" would help insure a correct interpretation of the section, line 6 sentence. 1003. Section 0.2, page 0-Please consider adding the qualifier that the mean hazard from the Done 2, 3'0 paragraph of section, 3'" sentence common-form models plots near the upper limit of the GMPE range at the relevant hazard levels (e.g., 10* and less) and that this does not seem lo be so clearly the case at higher hazard levels. 1004 Figure 0.2-1a, Page In this and all similar figures in this appendix, please use the same Done 0-3 acronyms for the models listed in the legend that are used elsewhere throughout the report and appendices (e.g., use "ASK14" instead of "ASK") 1005. Section 0.3. General Except for showing hazard curves from Model A and Model B See answer to question 997 together on the same plot, Section 0.3 appears to provide the same information as provided in Section 9.1.1.3 (and Figures 9.1-19 and 91-20). Please clarify what is new in Section 0.3. compared to Section 9.1.1.3. 1006 Section 0.3. Page 0-Please see comments given in other chapters and appendices References fixed (Akkar & Bindi); Consistent acronyms used 7, 2nd Paragraph regarding suggested revisions to the bullet list of references to these six GMPEs. 1007. Section 0.3, Page 0-Please avoid the use of the subjective term "significant" and instead Sentence has been rewritten 7, 3rd Paragraph, 9th provide a quantitative metric to describe the contribution to the Line hazard of the distant seismic sources 1008. Section 0.3. page 0-Please add a comma after the word "strong, to signal that the Done 8, last line subsequent "as" is being used as a conjunction to introduce a clause (not to express similarity). 1009 Figure 0.2-1a, Page It is difficult lo tell the difference between the two blue dashed Not done at this lime 0-9 curves in this plot. Please use a different color andlor symbol so that these two curves can be more easily distinguished in this and similar figures in this appendix. 1010. Section 0.4. Page 0-Please ensure that all of the references cited in the text are included Done 13 in the list of references and that all of the references provide a complete description of the publication (e.g., volume and page numbers). APPENDIX Q Host Kappa 1011. General comment A list of references is missing from the appendix. Please include a This Appendix is now renamed "M. complete list of references in a separate section of the appendix. References are now inserted 1012. General comment There are a lot of parameters. terms, and acronyms used throughout Done everywhere in Appendix Mas applicable the appendix without first being defined. As a reiteration of previous comments on various chapters and appendices in this report. please ensure that all of the parameters. terms. and acronyms used in this appendix are defined in a list prior to their use. Otherwise, they will need to be defined the first time they are used in each chapter and appendix. 1013. General comment Please check, in this appendix and throughout the report. to ensure Clarification on the meaning of Host Kappa has been that geographical terminology and acronyms are consistent with provided. II is not related to the host region from the SSC usage in the DCPP and PVNGS SSC projects. One example worth perspective. checking is whether "Sonoran Basin and Range" is the name for the PVNGS host region (please confirm that it is not "southern Basin and Range" in the PVNGS SSC, or if it is, make changes to ensure consistency). 1014. General comment Please make the notation consistent throughout the chapter (and Changed kappa(O) to Ko consistent with the rest of the report). For example, the decay exponent is sometimes spelled out in roman letters as "kappa", sometimes given by 1he Greek letter i-:, and k, and k1 seem to be used in1erchangeably (and k(O) is used in lieu of i-:o, even though the latter seems to be advocated by Ktenidou et al., 2014). In the process of clarifying, please also give consideration to the merits of following as strictly as possible the published taxonomy of Ktenidou et al. (2014). 1015. General comment Please define kappa and provide the foundational references that A new section ("Kappa Components and Terminology") was established the empirical basis for this concept added to provide a description of kappa, its componen1s and the adopted terminology. 1016. Page Q-1 , first The term "Host kappa" is jargon that only insiders will understand, Host kappa is defined in Chapter 5.5.3. Cross reference paragraph particularly since "host" is used in multiple, seemingly quite different added, and definition repeated senses in the report (e.g., in Chapter 14, "host" refers to the Sonora Basin and Range region in which PVNGS is situated). Please begin by explaining precisely what is meant by the term in the current chapter and how the host kappa estimates are then used in the GMC model. Please also cross-reference those places in the report where the resulting kappa estimates are used. 1017. Section Q. 1. Page 0-Please revise the Akkar et al. Bindi et al.. and Zhao references to Fixed in Appendix M (formerly Appendix Q). Completed on 1, 1st Paragraph of show the correct publication dates and acronyms (as used figure labels. Section elsewhere throughout the report and appendices) and to include the published errata for the first two references. Please also ensure that the correct acronyms for the GMPEs that are used throughout the report and appendices are used here and elsewhere throughout the appendix, including in figure legends and figure captions. 1018 Section 0. 1. page 0-Please provide the meaning of IRVT upon its first occurrence, and Reference included in response to comment #1020 1, 2M paragraph of provide a reference to the method (not just to the computer section, 1*1 sentence program). 1019 Section 0. 1. page 0-Please rewrite the sentence with parallel construction to improve Done 1, 3r<1 paragraph of clarity (e.g., "for spectra with higher host kappa than for those with section, last sentence lower host kappa," if that is the intended meaning). 1020. Section Q.2, Page Q-Please provide a reference for 1he IRVT approach that is used, (e.g., See answer to 1018 1, 1st Paragraph of if it is that published by Al Atik et al., 2013, please indicate that). Section, 1st Line 1021. Section Q.2. page Q-This comment refers to the phrase "while also limiting the a Sentence removed to avoid confusion and this point is 1, 1"' paragraph of attenuation effects" The kappa effect is itself most likely, at least in clarified in the added section "kappa Components and section, Line 4 part, a Q effect (which would be better described as an "anelastic Terminology". effect"). but just one that is so localized that it is more practical to treat it as a separate site-associated parameter. To avoid feeding confusion on this point, please state more precisely what is meant by this phrase. If the Tl Team chose close stations in order to isolate that part of the attenuation that persists in the limit of short propagation paths and is therefore suited to modeling as a site-associated attenua1ion factor exp(-pi"kappa"f), please indicate that 1022. Section Q.2, Page Q-Because of its common use in stochastic simula1ion, please also The Boore and Joyner (1997) Vs profile and corresponding 2, 2nd Paragraph on provide and plot the Vs profile for the WUS crustal model of Boore site amplification factors were not used in the derivation of page, 1st Sentence and Joyner ( 1997) in Figure Q-1 . Likewise, please plot the related the host kappa values. Therefore, Figures M-1 and M-2 only site-amplification factors for the WUS crustal model of Boore and show plots for the profile that is relevant for this study. Joyner (1997) in Figure (0-2). 1023. Section Q.2, Page Q-Please describe and reference the "OWL program" that was used to We added reference to Boore (2005). Also, added reference 2, 2nd Paragraph, 6th obtain the Vs-density relationships and summarize those to Boore's write up on the Vs-density relation Line relationships for completeness. 1024. Section Q.2. Page 0-Please explain what an angle of incidence of zero means and why it A discussion on the impact of using a different angle of 2, 2nd Paragraph, 5th was assumed to be zero and what impact this assumption has on the incidence on the results is added. Sentence final results. 1025. Section Q.2. page 0-Please consider referring to "the nine selected scenarios" to clarify Done 3, 3rd paragraph of that the reference is to the selections made in the earlier paragraph section (1" on page), for the reasons stated there. The current language given by the 1" sentence phrase "the nine scenarios considered," could be misunderstood as part of an evaluation process (i e , that some were considered and rejected, for example). 1026. Section Q.2. page 0-This sentence asserts that the kappa derived using the IRVT Refer to the added section "Kappa Components and 3, 3m paragraph of approach (k1) is not equal to kappa(O). This categorical statement Terminology" which elaborates on this point. section (1" on page), could imply that k1 is in principle not able to capture kappa(O). Is that line 8 &9 really the meaning intended? If so. please explain. and reconcile this assertion with the fact that Ktenidou et al (2014) classify the IRVT-derived method as a k(O) estimator in their Table 1. Otherwise, please reword these lines. 1027. Section Q.2, page Q-As noted in an earlier comment, the reference here to "anelastic This is now better described in the added section "Kappa 3, 3'0 of attenuation" implies that the kappa decay factor is not a Components and Terminology" section (1" on page), consequence of anelastic attenuation. whereas the scientific 2"c to last sentence consensus is that it is (at least in part). Please reword this sentence to express the intended meaning more precisely. 1028 Section 0.2. page 0-Please explain the distinction being made here between k(O) and This is explained in the added section "Kappa Components 3, 3'° paragraph ( 1 ** k,;, ** and justify the assumption that there is no source contribution to and Terminology" with appropriate references added. on page), last line kappa. 1029. Section Q.2. page 0-Please explain what is meant by "best picks. On what criteria was "best picks" is replaced with "best visual picks" 3, 4'"' paragraph of the selection made? section (2"" on page), Line 5 1030 Section 0.2. Page 0-Because this appendix is intended to present the details of the host Plots are added for all 9 scenarios for all seven GMPEs 3, 2nd Paragraph on kappa calculations. please provide plots for all nine scenarios for all page, 5th Sentence seven GMPEs for completeness. 1031. Section Q.2, Page Q-For completeness, please provide the standard deviations of the Evaluating the uncertainty of the host kappa values to the 3, 2nd Paragraph, 6th host kappa values shown in Table Q-1 that account for uncertainty in selection of f1 and f2 and to the use of different host Vs Sentence the f1 and f2 picks, the nine different scenarios, and the two different profiles is outside the scope of this Chapter. The goal here is crustal models. to provide best estimates for the host kappa values. The standard deviations of the host kappa values for the nine scenarios used are added to Table M1. 1032. Section Q.2. page 0-The phrase "best estimate" seems to be used in two different senses This sentence is rephrased. 3, 4"' paragraph of in its two occurrences in this sentence. Please clarify. Also note that section (2"" on page), there appears to be a missing word or words after "GMPE." last sentence Comment Response Table Comment Location in PPRP Comment Summary of Revisions to Report Number Text CHAPTER 1 Introduction Lines 51-55 Suggest this sentence be broken into 2 sentences for clarity done Line 62 Comma after "site-specific rock condition" done Line 91 Suggest putting Q in parentheses done Line 149 Fix margins Done, use justified margins CHAPTER 2 Project Organization Line 13 Suggest comma after "(U.S. NRC, 1997)" done Line 35 Set should be plural done Line 99 Product should be plural done Line 146 Estimated should be estimates done Line 155 Suggest comma after Arizona done Line 238 Suggest comma after comments Done Line 240 Suggest insertion of "the" after reviewing Done Line 252 "shows the dates of the main .. " change "of' to "that" done CHAPTER 3 Work Plan Line 9 Suggest insertion of "the" belween "as" and "kick-off' done Line 120 Station should be plural done Line 125 Suggest comma after "conducted" done Line 159 Questions should be plural Done Line 187 Include should be included Done Line 224 Suggest insertion of "the" between "In terms of' and "sigma models" Done Line 238 Insert "to after "prior done Line 291 Insert "to" after "pertaining" done CHAPTER 4 Seismotectonic Setting Line 60 Ranges should be singular done Line 112 and 116 Capi1alize Southern consistently, or use lower case consistently for Done. Capitalized notation is used Southern Basin and Range. Suggest caps. as we have formalized the term SBR Chapter 5 Ground motion Databases Line 37 Suggesl comma after residuals done Line 140 Suggest insertion of the" between "For" and "objective" done Lines 140, 141 Suggest period after "al" in Lin et al. (here and elsewhere) done Line 186 Suggest changing containing to contains. done Line 313 Suggest comma after (Pasyanos et al., 1996) done Line 385 Ruptures should be plural. done Line 422 "using for?? should this be used for? done Line 451 "The subsets of the subset of... is confusing. Is this correct? Please Done. consider rewording. Line 484, 485 Was selected is repeated as selected was This is a confusing done sentence -consider rephrasing. Line 498 "study" should be studies done Line 501 "and by the distant" should be "and from the distant" done Line 579-580 There is no verb in this sentence done Line 586 Figures should be singular done Line 623 The citation to Table 5.4.4-1 has an extra period "4.-1" done Line 654 Function from? Do you mean functional form? done Line 695 Insert "and" between "another" and "should" done Line 699 A comma is needed after "selected" done Line 703 Change rejection to rejecting. or place "of' after rejection done Line 703 "ad" should be "and" done Line 752 Suggest a comma after is used" done Line 754 Suggest set be pluralized done Line 777 Suggest a comma after data" done Line 787 Change "as" to "at" done Chapter 6 GMC Models For the Median Line 16 Delete up" fixed Line 42 Delete the extra ) after T akedatsu, 2015 fixed Line 57 Insert "to" between "leads" and a model" fixed Line 58 Add "because" after **and furthermore." fixed Line 67 Magnitude should be plural fixed Line 71 Add a comma after "50 km) fixed Line 143 Replace "in" with "on" -Based on ... fixed Line 155 Insert "a between "explained as" and "geometric" fixed Line 238 This would read better as " ... Model to account for the HW ... fixed Line 274 Was calculated or were calculated? Line 362 Place a comma after GMPE. Also. magnitudes should be plural. fixed Line 439 Place a comma after (Model B) fixed Line 466 Insert "and" after M>7.5, fixed Line 496 Place a comma after "used" fixed Line 542 HW models" -models should be singular. fixed Line 548 Change applies to applied fixed Line 569 Set off wi with commas fixed Line 594 In is given" should read "It is given" fixed Line 615 "the difference is scaling" -is should be "in" fixed Line 801 Reflects should be singular fixed Lines 802/803 Move "fully" to before "represents fixed Line 830 Example should be plural fixed Line 882 Figures should be lower case fixed Line 892 "These two model" -model should be plural fixed Line 902 Insert "to the between similar and Spudich fixed Line 936 Insert a comma after (20t4) fixed Line 954 Insert "a between "for" and "strike-slip" fixed Line 1019 Insert "a between ruptures of' and splay fault" fixed Line 1029 Insert an "a" between Approximate a" and "Single Fault". Same with fixed next two lines. Chapter 7 GMC Models for the Sigma Line 12 The closing parentheses should not be subcase fixed Line 100 Insert a comma after "used" fixed Line 101 Insert a comma after "data" fixed Line 107 Insert a comma after "used" fixed Line 108 Insert a comma after "residuals" fixed Line 194 Delete the extra "for" near the end of this line. fixed Line 290 Insert "of' between "distances" and "200-300". Also, Section should fixed be lower case. Line 291 Indicated should be indicates fixed Line 301 Insert "a" between "of' and "few" fixed Line 318 "explanation or this trend change "or" to "for" fixed Line 382 with respect of distance" should be "with respect to distance" fixed Line 499 Provide should be plural Fixed: the figure is now singular, so the verb is written as "provides" Line 518 Insert a comma between branches" and "is developed" fixed Chapter 8 Median GMC Models: DCPP Line 36 Suggest a comma after figures" fixed Line 42 Consider changing random to randomly fixed Line 55 Fault should be plural fixed Line 60 "to the five" should be "for the five" fixed Line 86 "DCPP has made .. . should be "DCPP was made" fixed Line 167 model this penalizes" should read "model that penalizes" Sentence restructured Line 293 Insert "and" before "as noted" Sentence restructured Line 377 Insert a comma after "removed" fixed Lines 395-396 Place a comma after magnitudes and delete the and" before fixed distances Chapter9 Median GMC Models: PVNPP Line 11 Tl Team should read Tl Team's. Also. weighed should be weighted. fixed Line 25 Capture should be plural It is plural (associated to "weights") Line 40 Insert a comma after "considered". Also. (NGAW2-pv.MEov fixed needs an end-parenthesis Line 41 Remove end-parenthesis after Section 5.3.2 fixed Line 82 Insert a comma after "respectively" fixed Line 86 Under laying?? Underlying? fixed Line 119 There is an extra period after "is used" fixed Line 185 Magnitude should be plural fixed Line 182 Insert comma after "Figure 9. 1-2 fixed Line 219 This sentence would read better if "and that" was replaced by fixed "whereas'" Line 226 "right and side"?? You mean right hand side, correct? Line 254 "is referred to as "influence diagram" -insert "an after "as" fixed Line 278 Insert "to" after "respect" fixed Line 356 Remove the comma after "Section 5. 1.5.2" -it is not needed. Also, Inserted "rupture" after "each" "(M6.5 for each ... " Each what? Lines 412-416 Break this into 2 sentences. Start the 2"" sentence at 'Therefore, ... ** fixed Line 424 Sentence ends with a comma. fixed Chapter 10 Tau Model Logic Trees Line 4 Sectrion should be Section. Line 7 Insert "a" between "develop" and "single" fixed Line 34 Insert "that" after "2014 )" ok Chapter 11 Phi Model Logic Tree: DCPP Line 23 Place a comma after Taiwan. fixed Line 53 Place a comma after "Appendix R fixed Line 59 Place a comma after "respectively" fixed Line 79 Delete "a" between "as" and "heavy-tailed" fixed Line 127 Insert a space after phi Cannot find instance Line 132 Delete "the" between "because and "most" Chapter 12 Phi Model Logic Tree: PVNPP Line 10 Insert comma after PVNGS fixed Line 12 There should be the. Plus insert "are" after "the" "there" changed to these" Line 13 Need a) at the end of the sentence. fixed Line 28 Delete the extra space before the period. fixed Line 29 Insert "which are" after "events" fixed Line 30 Toe should be to. fixed Line 46 Number should be plural fixed Line 50 Time should be plural fixed Line 52 Insert "the" before Tl Team fixed Line 72 Insert a comma after "respectively" fixed Line 102 "dataset contains should read "datasets contain". Also, insert a fixed comma after "records" Line 123 Magnitudes should be singular fixed Line 132 Insert a comma after "respectively" fixed Line 137 Insert a comma after "respectively" fixed Chapter 13 Total Sigma Model Line 32 Approached should be approaches fixed Line 39 Represent should be plural It is singular and now reads as "represents" Line 42 Insert a space between "the" and "greater fixed Line 52 Change the period to a comma after Appendix P fixed Line 54 scaled" is repeated -delete one. fixed Line 74 One to one -correct the zero to a lower case o fixed Line 76 Point should be plural fixed Line 82 "uses" should be "used". Also. "numerical" should be "numerically" fixed Line 109 "Greater Arizona source" -source should be plural. fixed Line 125 Insert "as to after "designated" fixed Line 132 Delete "for" between "of the" and "single" fixed Line 135 indicated" should be "indicate". Also, insert "with" between that" Sentence slightly modified to fix issue and "the Line 176 Insert "affects" after "path" fixed Line 182 The title should read "Implementation of the Mixture Model fixed Chapter 14 Hazard Sensitivity Line 15 Insert comma after "plant sites" fixed Line 164 Insert comma after "several nodes" fixed Line 351 "show should be plural fixed Line 403 Change "that" to than fixed Line 461 Insert a comma after "approach" fixed Line 473 Delete "in" (presented in with the next case) fixed Chapter 15 Application Guidelines and Limitations Line 34 "then" should be "the" fixed Line 45 Insert "a" between "at" and distance" fixed Line 56 Available" is misspelled. constraint" should be constrain". fixed Line 57 "comprising is misspelled fixed Comment Response Table Comment Location PPRP Comment Summary of Revisions to Number in Text Report Tier 2 Comments (by chapter) General 1041. NIA Please carefully review the references for completeness and to ensure that all cited references are Mostly done in Rev. 1. Completed in Rev.2 listed. For example, some of the same references in different chapters are listed slightly differently (i.e., one might be missing a volume number or page numbers while another might not). 1042. NIA The report is written primarily in third person. which implies that the writers of the report. chapter, An author list is now included in the TOC andfor section performed the work or made the decisions and assumptions that are being described. (second page). However, there are no specific authors listed on the report. which is only identified by the publisher. GeoPentech, and a list of participants in the project. Please make ii clear who the writers of the report A comprehensive check was made to are either on the Title Page (ideally) or in the introduction so that there is clear ownership of the work ensure that the personnel performing the that is being described in the third person. When the description refers to someone else's work, evaluations or assessments are clearly decision. or assumptions, please make it clear that this is the case. There are also still sporadic uses defined. of the pronouns "we" and "us" throughout the report, which is even more ambiguous. Please consider replacing these pronouns with the person or group that the pronoun refers to (e.g., the Tl Team or a specific Resource Expert) or change the sentence to third person to refer to the identified writers of the report. CHAPTER 0.-Table of Contents 1043. NIA The Section No. 5 21. t appears twice. The second one should be 5.2.2. t. Fixed 1044. NIA In the title of Section No. 5.5 3, Vs should be Fixed 1045. NIA The Section No. 6 4 5 3 appears twice. The first occurrence should be 6.4.5.2. Fixed CHAPTER 1-Introduction 1046. Lines The description of Vs'¥! as "shear-wave velocity" should be more accurately described as "travel-time-Done in both locations 57-58 averaged shear-wave velocity." This change also applies to the definition of Vs30 in the list of terms and acronvms. 1047. Line 63 Please define "kappa," since this is the first time that this term is used in the report. Please also add Done in both locations the definition of kappa to the list of terms and acronyms, which only contains the specific symbols used to characterize the different ways kappa can be estimated and no definition of the generic term kappa itself. 1048. Line 80 Please define "sigma, since this is the first time that this term is used in the report. Please also add Term sigma is now introduced in Section the definition of sigma to the list of terms and acronyms, which only contains the specific symbols used 1. 1. and defined in abbreviation list to characterize the different types of standard deviations and no definition of the generic term sigma itself. 1049. Line Please consider replacing the phrase "suites of models" with "representative suite of models" here and Done 109 elsewhere in the report to conform with terminology used in "Atkinson. G.M., Bommer, J.J.. and Abrahamson, N .A. (2014 ). Alternative approaches to modeling epistemic uncertainty in ground motions in probabilistic seismic-hazard analysis, Seismological Research Letters, Vol. 86, pp. 1141-1144." CHAPTER 2-Project Organization 1050. Line 52 The description of the workshops is incomplete and does not list all of the purposes of the workshops. Sentence modifies to add the qualifier Please qualify the sentence to indicate that this is only one of the purposes of the workshops or "among other purposes. the Workshops .. " .. exoand it to list all of the ourvoses. 1051. Line 53 Since this is the first time that peer review is mentioned in the report, please introduce the peer review PPRP is already introduced in Section panel and the acronym PPRP. Please also add the definition of PPRP to the list of terms and 2.1.2. and is already included in the list of acronyms. acronyms 1052. Line 75 The use of the phrase "Appendix A of Appendix A" is awkward. Please consider calling the appendix oJ Done in Chapter 2, cannot make the an appendix something different in order to avoid confusion (e.g .. "annex"). change in Appendix A because that is an executed document 1053. Line 81 Please correct the name of the power plant, i.e., "Saint Onofre" should be "San Onofre. Done 1054. Line Please correct the grammar in this passage, e.g., "preliminary estimate of the kappa sensitivity .. . Fixed 146 1055. Line The large magnitude earthquakes in California cited here appear to be the same events referred to "and Mexico" added 157 elsewhere in the report as large earthquakes in California and Mexico (appropriately, since the 2010 El Mavor-Cucaoah event is included). Please clarifv or correct for consistencv. 1056. Line Please provide a reference to the PEER report that is mentioned in this sentence. Section mildly rearranged to provide the 162 requested citation (Kishida et al.. 2014) 1057. Lines Please provide references for the PEER projects that are referred to in this paragraph. NGA-Subduction effort is now referred to 167-(reference provided by Yousef Bozorgnia) 171 1058. Line Please reference the report or appendix where the PE&A study can be found it is not a report, but the material was 187 presented in the Workshop #1 presentations 1059. Line Please consider replacing the word "sensibly" with one that better conveys what the writer intended to Changed to "significantly" 189 mean. 1060. Line Please explain what "anticipated" means in this context. Changed to "preceded" 253 CHAPTER 3-SWUS GMC Work Plan and Key Study Tasks 1061. Line 97 Please confirm that the distance range "30-100 km" is correct and should not be "less than tOO km." Changed lo "less than tOO km" 1062. Line In Table 3.4-1, "Ken Campbell Consulting" should be "Kenneth W Campbell Consulting." fixed 152 1063. Line Please clarify that "the second meeting" refers to the January 2014 Special Working Meeting. Clarification added 244 1064. Line In Table 3.7-1, "Ken Campbell Consulting" should be "Kenneth W Campbell Consulting." fixed 340 CHAPTER 4-Seismotectonic Setting 1065. Line Please explain the difference between "layered faults" and "individual faults." Definition of "layered fault added to text 160 1066. Lines These lines refer to two categories, namely "the California and Mexico faults (referred to as Regions 1 Entries in the table are now aligned with the 163-and 2&3 in this Report)," and "other faults (AZ,NM, NV, and Mexico)." Table 4.2-2 has rows for "CA text in the chapter 164 Faults" and "AZ, NV, & Mex Faults. Do the rows of the table correspond to the two categories of faults described in the text? If so, please align the te1TT1inology; if not, please clarify 1067. Lines The legends of Figures 4-8a and 4-8b are not well correlated with the text. For example, "NSHMP Clarifying text is provided in the chapter 172-faults" are noted in the legends but are defined neither there nor in the text And the text calls attention body. Also, a new set of figures showing the 179 to the dominance of distant fault sources for low frequency at 1 O"" AFE, but the figures do not identify contribution from individual faults has been the curves associated with "distant fault sources." Please reconcile the figure legends and the text. added: this supports the conclusions on the distant sources being the main contributors at low frequency 1068. Line In Figure 4-8a, please explain the meaning of "coarse" and "fine" areal sources. The meaning has been introduced in 289 Section 4.2 3 and is not repeated in the fiaure caption 1069. Line In Figure 4-Sb, please explain the meaning of "coarse" and fine" areal sources. The meaning has been introduced in 293 Section 4.2 3 and is not repeated in the figure caption 1070. Tables Please identify the pertinent site (i.e., DCPP or PVNGS) in the title of each of these tables. Done 4.1-4, 4 2-1. 4.2-2 1071. Figure The two line colors for the SAF are not well distinguished in the figure. Please consider making Done 4-t improvements to remedy this. 1072. Figure Please identify the site (DCPP) in the figure caption. Done 4-2 1073. Figure The arrow for the Cerro Prieto fault points to the Imperial fault (CPF is the next bold red line to the Done 4-6 SW). Please correct this. CHAPTER 5-Ground Motion Databases and Candidate Models 1074. Genera Two references for Kishida et al. 2014a and 2014b, appear in the reference list However. many of the Fixed Now the two separate references are I citations in this chapter refer only to Kishida et al. (2014) without distinguishing 2014a from 2014b. appointed to as 2014a and 2014b Please check and correct this omission. 1075. Genera The figure numbering scheme seems to be inconsistent in this chapter. For example, Figure 5.2.2-2 is Done. Now the figure and table numbers I called in Section 5.2.2.1, indicating the convention that only the chapter number and first two section reflect the two section level levels prefix the sequence number. But a Figure 5.2.3.4-1 is called in Section 5.2.3.4, so in that case the chapter number and all three section levels prefix the sequence number. There are some other anomalies as well. Please check carefullv and ensure that numberina is done consistentlv throuahout. 1076. Line 11 Use of the term "proponent models" is confusing, especially given that the report is written in third Word "proponent substituted with SWUS person with no identified authors. The term is usually reserved for describing a model or method GMC proposed by a Proponent Expert (PE). If this is not the meaning of the term in this context or in similar contexts elsewhere in the report. please consider using another term to describe the models or identify who the proponents are (e.g., "Tl Team proponent models") when the term is used. 1077. Line 27 The intended meaning of the sentence is ambiguous. If the intent is to say that the Wells earthquake Done was in the southern Basin and Range, please review for accuracy (e.g., was it in the northern or southern Basin and Range?). If the intent is that the Wells earthquake provides control for a normal faulting earthquake, if one should occur in the Southern Basin and Range, please clarify and correct, as needed. 1078. Line 31 Since this is the first time that the term "PSA" is used in the report, please define it Done 1079. Line 47 Please add that the bottom frames also show the number of recordings per site class. Verbiage added to address that the frame addressed the number of recordings per site conditions (VS30) 1080. Line 85 There is no evidence in Figure 5. t.2-1 of "Station Z14A, shown by the open star". Please clarify. Sentence restructured and reference to star removed (it was old text associated to a previous version of the figure) 1081. Line 87 Please complete the citation of Kishida" (ie., Kishida et al. 2014a or 2014b?). Done 1082. Line Please correct the figure number on this line, which should be Figure 5.1.5-1. Done 158 1083. Lines The spelling of the fault names differs between the text and Figure 5.1.5-2 ("ltozawa" in the figure Done 173-becomes "ldozawa" in the text, and "Yunodake" in the figure becomes "Yunotake" in the text). Please 174 edit for consistency. 1084. Lines The total moment given here and attributed to personal communication is inconsistent with the Paper of Tanaka et al is now quoted as a 175-moment magnitude of 6.7 given for this event on Line 164 (the sum of the moments on Line 175 imply reference of almost equal moment 176 M 6.56). Please resolve the inconsistency. In doing so, please consider whether it would be partitioning (Rev.2) appropriate to cite published moment estimates (e.g .. Tanaka et al., 2014, report a moment consistent with M 6.7 and approximately equally partitioned between the two faults) instead of those reported from oersonal communication. 1085. Line Please supply the missing Table 5.1.7-1. The correct citation is the table 5.1.2-2 202 1086. Line The symbols referring to the different types of kappa used in this sentence are slightly different from Done in this Section, a final check is 209 those listed in the terms and acronyms. Please use a consistent set of symbols for kappa throughout pending throughout the report the report and appendices. 1087. Line "co is undefined at this point in the text. Please correct this. Term introduced 216 1088. Line Please consider whether a more appropriate characterization than "upper bound" can be used here Done 223 (e.g., is that categorical statement even consistent with the one standard deviation ranges cited for the other methods?). 1089. Line Please include a reference to a publication describing the SCEC BBP (e.g., the paper by Maechling et Reference added 228 al. in the JanfFeb 2015 SRL may be appropriate). 1090. Line Please consider citing the published paper by Dreger et al. (2015) in the Jan/Feb 2015 SRL. Done 242 1091. Lines It is appropriate for the Tl Team to rely on the SCEC Validation Review Panel for the technical analysis Done 264-of the simulations, and to rely upon the judgment of that panel to determine which methods met the 266 acceptance criteria established in that review. However. the Tl Team itself needs to justify that meeting those acceptance criteria makes the methods suitable for the specific purposes for which the simulations are to be employed. Those purposes are staled on Lines 227-233. Please augment the summary statement on Lines 264-266 by explaining how meeting the SCEC review panel's acceptance criteria makes the simulation methods suitable for addressing the problems laid out on Lines 8-14. 1092. Lines This passage needs rewriting because: (1) the BSL model is not identified as GIL7 on Line 309, but Done 306-seems to be the same as what is called GIL7 in the legend of Figure 5.2.2-1 and then on Line 312; and 315 (2) the passage is repetitive (e.g., the verbiage about routine estimation of moment tensors on Line 309 is repeated on Line 314-315; the basis of the GIL7 model in broadband waveform modeling is staled repetitively on Line 308 and then on Line 314} 1093. Line "Frequency wave-number" is written differently on this I ine than it was on Lines 304 and 311 Frequency-wavenumber used in the section 322 ("frequency-wave number"). Please review the hyphenation convention and apply one consistently consistently (note also that both "wave number" and "wavenumber** are in common use, so the easier-to-read form "frequency-wavenumber" is also an option). 1094. Line "Area" is used to signify rupture area in Equation 52 3-1. but "A" is defined as rupture area on Line Done 361, 364. Please edit for consistency. 364 1095. Lines Please indicate whether this statement is an assumption or is based on an evaluation of data, models, Done 374-etc., by the Tl Team. 375 1096. Line Please correct the figure number. It is called out as Figure 5.3.2.1-1 on this line, but the figure itself is Done 383 labeled as Figure 5.2.3.1-1. Moreover, the numbering scheme used elsewhere in the report appears to call it Figure 5.2.3-1, since it occurs in a subsection of Section 5.2.3 (e.g., by analogy with the fact that Fiaures 5.2.2-1 and 5.2.2-2 occur in Section 5.2.2. n 1097. Line The figure number 5.2.3.2-1 is inconsistent wi1h the fact 1hat it is 1he second figure in the subsection. Done 392 Please check the figure numbering convention and make it consistent with the rest of the chapter and report. 1098. Line Please indicate that CB 14 also used the functional form of the hanging-wall term developed by Done 396 Donahue and Abrahamson (2014). 1099. Line Please consider replacing "we" (first person) with third-person to be consistent with the remainder of Done 411 the report. 1100. Lines The figure citations do not correspond to the figure numbering. Please check the figure numbering Done 427, against the figure citations and correct as needed. 431, and 433 1101. Line The table called Table 5.1.1-2 on this line appears to be the table labeled Table 5.1-2 (and called by Corrected 452, those numbers elsewhere in the report). Please correct here and in subsequent occurrences. 458 1102. Line Line 464 gives the distance criterion for NGA-W2_DC-MED as abs(Rx)<70km, whereas the lines 475 Done 464, and 481 give it as R<70 km, which is more restrictive. Please clarify how the various distance metrics 475, are used together to screen records for NGA-W2_DC-MED. 481 1103. Line Please quantify what "similar enough" means in regards to the value of (e.g., in terms of the Done 492 percent difference in site-amplification factors). 1104. Line Previously, Akkar et al. (2014c) was cited as the database reference. Please check whether the Clarification added -it is a subset of the 506 citation given on this line is correct in the present context. dataset used to derive the ASB 14 model, which in turn is a subset of the RESORCE database (Akkar et al 2014 c) 1105. Lines The criterion abs(Rx)<70 km leaves the total distance unconstrained. Please provide a complete Disagree, the abs(Rx)<70 corresponds to 508 statement of the distance selection criterion. Rx values less than 70 km on footfall and and Rx <70 on the hanging wall. It is not 517 unconstrained. No chanae in text. 1106. Line Please consider whether this might be a good place to introduce the symbol *** so that it will be Done 548 defined prior to its use on Line 553. 1107. Line Disaggregation" is used on this line, whereas "deaggregation" is used elsewhere in the report. Please Done 558 edit for consistency. 1108. Lines The selection criteria (distance. magnitude. number of recordings per event and site) do not seem to Sentence added 565-be given. Please check and correct if necessary. 572 1109. Line "NGA-W2 is "NGA-West2" elsewhere. Please edit for consistency. Done everywhere 566 1110. Line Please check whether "for use in" should be "is used in". As is, the sentence lacks a verb. Changed to "to be used in" 579 1111. Line Please add the missing parenthesis closure. Done 585 1112. Lines Please indicate whether the 3 events per station requirement was also applied. Yes, clarifying sentence added 592-593 1113. Line Section 5.41 does not contain the discussion of the Idriss 2014 model that is referenced here ("As Section 5.41 has now a sentence 601 noted in Section 5 4 1 "), nor does there appear to be any prior reference to the Idriss model in the describing how Idriss (2014) treats the chapter. Please make the necessary corrections. residuals 1114. Line Please replace "200-30 km" with 30-200 km." Done 610 1115. Lines CB 14 used mixed-effects regression to derive the anelastic attenuation term from data with RRuP > 80 Requested clarification added 614-km, but allowed the source terms to vary from those for RRuP < 80 km. Although this does not 615 necessarily impact the decision not to use CB14, the description of what CB14 did should be correctly stated in the text. 1116. Line Please indicate what range that "this magnitude-distance range" refers to. (M;:: 5.5. distance 200-400 km) added lo 619 the text 1117. Lines Line 619 has the statement that "the global dataset in this magnitude and distance range consists of Second sentence has been removed 619 264-415 recordings from 4 to 23 earthquakes." Line 625 states 'Within this magnitude and distance because it added confusion without and range, the global dataset contains four earthquakes and 280 records." Please clarify why these additional information 626 statements are not contradictory. 1118. Line The cited figures do not exist. Please add them. Figures existed but were misnumbered. 627 Figure number has been corrected 1119. Line Please correct the figure references (they should be to Figures 5.5.1-1 and 5.5.1-2). Done 669-670 1120. Line Please correct the figure reference (it should be to Figure 5.5.1-3). Done 673 1121. Line Please correct the table reference (the intended reference appears to be to Table 5.5.1-1). Done 683 1122. Line Please clarify why specific scenarios had to be specified. given that kappa is not being explicitly Kappa depends on the spectral shape 724 modeled as a source effect. which depends to the scenario. Clarifying text has been added 1123. Line Please explain why only footwall scenarios were used. Done 725 1124. Line Please consider rewording the reference to "Q attenuation." to avoid the implication that the kappa Done 727 effect is necessarily physically distinct from effects ordinarily parameterized in terms of 0. Isn't the point that the kappa parameter (or at least Ko) is intended to capture attenuation effects that are so localized that in a practical sense they are better parameterized as site terms than as path-dependent attenuation terms, and that therefore isolation of kaooa effects reouires short-distance scenarios? 1125. Line Please be more specific about which profile was used. Is it one of those in Figure 2.6 of Kamai et al. 760 m/s is correct. The profile referenced is 730 (one is listed as having Vs30 of 750 mis, none has exactly 760 mis)? the one in Appendix M 1126. Line Figure 5.5.3-1 appears to be labeled incorrectly. Please correct this. Done 735 1127. Line Rodriguez-Marek (2013) actually developed four single-station sigma models: one with neither M nor Text expanded to clarify the confusion 778 R dependence, one each with Mand R dependencies, respectively, and a fourth with both Mand R dependence. Please clarify which three have been chosen, and why. Note also that there is a perception of ambiguity introduced by mixing "dependent" and "independent" in listing the attributes of the selected models; i.e., is the "magnitude-independent" model alluded to also R independent (in which case it would be clearer to say "magnitude and distance independent). or is there a typo such that "magnitude-dependent" is what is actually intended? If one of the figures were not missing, this ambiauitv would be cleared uo. but it would be better to also do so in the text. 1128. Lines Please check whether the first of the three models alluded to should be "magnitude-dependent" (rather Text clarified to say that is magnitude-779 than magnitude-independent", which would appear to be inconsistent with the figures). Alternatively, if dependent and "magnitude-independent" is correct as written. please clarify whether it is paired with a distance 781 dependence or not. 1129. Lines Only the R-dependent and MR-dependent models are shown. and these are in Figures 5.6.2-3 and Done 780-5.6.2-4, respectively (not 5.6.2-4 and 5.6.2-5 as called in the text). The other model (called 782 "maanitude-independent" in the text} is not shown, nor is there anv Fiaure 5.6-5. Please correct this. 1130. Line Please cite a reference for the assertions about the small-magnitude limitations of GMPEs at short Atkinson 2015. Reference added in Rev.2 789 distance. 1131. Line Table 5.5.1-1 indicates that the Graizer (2014) GMPE was used for the DCPP GMC model. but the Table corrected. A reason to exclude the 1122 Graizer GMPE is not listed as being one of the models that was used in Chapter 6. Please either GK14 model has been added. In Chapter 6 correct the table or the text in Chapter 6. If this GMPE was used, please justify its use in view of the , we justify why using the GK1 model to fact that it is only published as a conference paper and has not been peer reviewed or vetted by the check the hazard. larger scientific community. 1132. Figure The caption cites Akkar et al. (2014a and 2014b). whereas the text (Line 121) cites Akkar et al. Clarification added 5.1.3-1 (2014c), apparently in the same context. Please check whether this difference is intentional and make a correction if appropriate. 1133. Figures These figures are mislabeled (as 5.2.3.3-1 and 5.2.3.3-2, respectively). Please correct. Fixed 5.2.3.4-1 and 52 34-2 1134. Figures Please correct these figures. In each of these figures, the second row repeats the first with a scale Fixed 5.3.2-1 change, and the remaining plots (recordings per site, recordings per event, etc.) are absent. and 5.3.2-2 1135. Line In Figure 5.4.1-2, please explain why there is a triangular symbol plotted at slightly over 100 km or, if Fixed in Rev.2 1258 this is an error, please remove the symbol. 1136. Line In Figure 5.4.1-3, please explain why there is a triangular symbol plotted at slightly over 100 km or, if Fixed in Rev.2 1263 this is an error, please remove the symbol. 1137. Line In Figure 5.5.1-1, please define the meaning of the solid black symbols and the color and black trend Done 1322 lines 1138. Line In Figure 5.5.1-2, please define the meaning of the solid black symbols and the color and black trend Done 1326 lines 1139. Figure Please correct the figure number. It is called Figure 5.5.3-1, but labeled 5 5 3-2. Fixed 5.5.3-1 1140. Figure Please improve the figure caption by including some basic contextual information Done 5.6.2-2 1141. Figure Please add the dataset identifiers given in Lines 805-808 of the text (Blea. Blea2. and ABR) to the Names added to the captions 5.6.4-1 figure caption. or else delete them from the text, as the inconsistency is confusing. CHAPTER 6-GMC Models for the Median 1142. Lines Table 5.5.1-1 indicates that the Graizer (2014) GMPE was used for the DCPP GMC model, resulting in Table 5.5.1-1 was corrected and some 23-24 the use of 9 models. The text indicates that 8 models, excluding the Graizer GMPE, were used. Please discussion added to Section 6.2.1 correct either the table or the text. 1143. Line Please hyphenate "large-distance attenuation" to resolve the otherwise ambiguous meaning. Done 105 1144. Lines Not all of the simulations show that hanging-wall effects persist down to magnitudes of 5.5 and 6.0 for Most of the simulations showed HW effects 209-all fault geometries. This suggests that there is some uncertainty in whether such effects exist. Please and the hazard sensitivities (Figure 0.2-3a) 210 discuss this apparent uncertainty and justify the decision to extend hanging-wall effects to smaller displayed that the effect is small, so we magnitudes, explaining whether this uncertainty is accounted for elsewhere. always included the HW adjustments. Discussion added. 1145. Lines Please explain why, if hanging-wall effects are geometric, the cosine term is more appropriate than the Discussion added 256-arithmetic angle to model these effects 257 1146. Line The statement that the hanging-wall models are "equally likely" and "normally distributed" is still Done 269 confusing on its face. However, the discussion that follows clarifies this apparent contradiction vis-a-vis the use of equal probability slices of the distribution. Perhaps, a statement like "as explained below" after introducing this apparent contradiction would provide less confusion for the reader. 1147. Line Figure 6.3.2-5 shows CB14 having a step-like change in its HW factor as Rjb approaches zero along Figure has been corrected and now shows 303 the strike direction. Please clarify how this is consistent with the claim that CB14 allows "a smoother the non-linear transition is smooth. but transition" around the rupture compared with some other models rapid. 1148. Lines In reviewing all of the figures comparing the HW adjustment model with the simulations, all except There were redundant figures. The figures 341-Figure 6.3.2-14 compare the simulations only with the central HW model In order to show that the five showing only the central model 343 HW models adequately capture the uncertainty in the simulations, please show all five HW models in comparisons were removed and the figures all of the figures and discuss any cases in which the five models to not appear to capture the showing the 5 equal probability models uncertainty. were retained. The text was modified accordingly. Also the figure numbering was not consistent with the section and the figure numbers were updated to 6 3.3-etc. It is pointed out that the HW model does not capture the simulations for points located off of the surface projection of the dipping fault (Rjb>O) and that the HWRjbTaper was designed to be consistent with the empirical data captured by the similar terms in the published GMPEs. Figures 6 3 2-7 (M5.5D45Ztor2.5-7-12) redundant with 11 Figure 6.3.2-8 (M6D45Ztor2.5-7-12) redundant with 12 Figure 6.3.2-9(M6.5D45Ztor0-7) redundant with 14 Figures 6.3.2-10(M6Ztor7D30-45-60) redundant with 13 Figure 6.3.2-11(M5.5D45Ztor2.5-7-12) 5 models Figure 6.3.2-12 (M6D45Ztor2.5-7-12) 5 models Figure 6.3.2-13 (M6Ztor7D30-45-60) 5 models Figure 6.3.2-14 (M6.5 D45Ztor0-7) 5 models 1149. Line The term "scaled-backbone approach" is never used by Atkinson et al. (2014). These authors do Sentence rephrased: "Atkinson et al. (2014) 363 mention the concept of selecting a single "central or backbone GMPE" and scaling it up and down, but introduced the concept of selecting a single do not specifically call this a scaled-backbone approach. Please consider replacing the term "scaled-"central or backbone GMPE" and scaling it backbone approach" wi1h a simple description of the approach instead. up and down. This concept is here referred to as the "scaled-backbone approach, which provides a method to develop a set of.. .. 1150. Line The term "generated models" is used in this sentence to refer to ground motion models derived from Done throughout report and Appendices 384 the visualization (Sammon's mapping) technique Terms such as "large suite of models" and (partially in Rev.1, completely in Rev 2) "representative models" were used earlier in the section to refer to similar models. The concept of using visualization techniques to produce a distribution of models that sample the full model space is difficult enough to understand without being confused further by the use of different terms to describe the same technique or products thereof. In order to avoid such confusion, please consider using a consistent and strict set of terminology to refer to these models. For example, the term "candidate models" has been generally used to describe the GMPEs that are used in conjunction with the visualization method, since this term is used elsewhere in the report to describe such models: the term "suite of models" might be used to refer to the entire set of models that are generated using the visualization technique (e.g., the 2000 common-form models); and the term "representative suite of models" might be used to refer to the final set of models that are used in the GMC logic tree (e.g., the 25 or so common-form models). This latter term is also consistent with the general term used by Atkinson et al. (2014) to describe the method of generating models that sample the model space, whether it be by simple methods (i.e., scaling up and down) or by more complex models, such as those sampled from the Sammon's map. 1151. Line It is possible that this is the first time that the term "Joyner-Boore distance" is used in the report. If so. Disagree. First occurrence of "Joyner-Boore 402 please note that this term refers to the distance metric RJa distance (RJa)" is in Section 6.3 1152. Lines Please delete "0,0" and replace "(fork= 7,8,9, 10)" with "(fork= 7,8,9)" since there is no k = 10 Fixed now (See general comment 1040) 412-coefficient in the model. 413 1153. Line Please replace "(fork= 7,8,9, 10)" with "(fork= 7,8.9)" since there is no k = 10 coefficient in the model. Fixed now (See general comment 1040) 429 1154. Line Please replace fork= 7,8,9, 10" with "fork= 7,8,9" since there is no k = 10 coefficient in the model. Fixed now (See general comment 1040) 433 1155. Line Please replace fork= 7,8,9 and 10 with "fork= 7,8 and 9" since there is no k = 10 coefficient in the Fixed now (See general comment 1040) 444 model. 1156. Line Please justify the selection of :::3 km to represent the uncertainly around the mean value of ZroR-Discussion added 449 1157. Lines In order for RJB to equal IRxl, the footwall site must be located at a source-to-site azimuth of -90 Done 463-degrees (i.e., perpendicular to the fault within the bounds of the ends of the rupture). Please indicate 464 that this is the case in order to justify the given distance equalities. 1158. Lines The term total residual" is usually reserved to mean the addition of the between-event and within-Fixed 472 event residuals in the aleatory variability model. Please consider calling this the total fitted residual" or and something like that to distinguish it from the true total residual. 493 1159. Lines The entire discussion of using candidate GMPEs and interpolated versions of the GMPEs and the A formula has been inserted to clarify the 502-generation and simplification of the coefficient covariance matrices is confusing to a non-statistician. concept 513 For example, what exactly are the sets of weights applied to and why can the covariance matrices be simplified in the manner discussed? Please consider expanding this discussion to better explain and justify exactly what was done. 1160. Lines Please justify how it is mathematically possible with the addition of the interpolated GMPE ground We demonstrate numerically that using the 506-motions to better capture the correlations? interpolation leads to a more stable 513 estimate of the covariance matrix. New paragraph inserted 116!. Line Please be precise about what types of standard deviations" are plotted in Figure 6 4 3-1. Plotted are the standard deviations for each 524 scenario in the vector that goes into the calculation the Sammon's maps (Vectors in Section 6.4.3). Clarifying text has been added to text and figure caption 1162. Lines This explanation needs to be set out more clearly. The sentence beginning on Line 536 states that "for Done 536-the DCPP application ... the central HW branch is applied to all common-form models." The rest of 548 the passage, although rather difficult to read, appears to indicate the following: (1) HW effects are omitted from the 2000 models used for the Sammon's map, (2) the central HW model is appended to those footwall models, solely for the purpose of the simplified hazard calculations used in the selection of representative common-form (footwall) models from the original 2000, and (3) randomly selected HW models (from the equal-probability set developed in Section 6.3.2) are appended to the selected representative set of footwall models, to give the final set of common-form models for application to DCPP. If this is a correct interpretation, then the last item seems to contradict the sentence from Line 536 (and if this is not a correct interpretation, some clarification is needed). Please rewrite for clarity and consistency. This paragraph would be less confusing if a strict use of terminology to identify all of the different types of models were used, as suggested in an earlier comment. Please be more specific in identifying what set of models are being described in each case. such as candidate models (i.e., the original published GMPES), common-form models (i.e .. the mean and interpreted GMPEs and presumably the 2000 or 7500 count versions as well), representative model (i.e., the common-form model that best matches the mean hazard in a given cell), and the suite of representative models (i.e., the ones that are eventually used in the logic tree). 1163. Line Please be explicit as to whether this paragraph is discussing the development of representative Fixed (refers to both sites) 552 models for both sites or just PVNGS. 1164. Line Please replace "magnitude/distance" with "magnitude-distance." Done 564 1165. Line Please review the appropriateness of subscript kin NG *. given that there is already a sum over k. Subscript removed (in Rev.2) 602 1166. Lines Please justify why uncertainty in Ztor is represented by adding 3 km to Ztor and not also subtracting 3 As noted in the previous comment# 1156, 614-km and why the value of 3 km was chosen to represent this uncertainty (see previous comment). this is not uncertainty in the mean Ztor for a 615 given magnitude. Two values are used so that the regression can determine the Ztor dependence. Because the scaling is linear with respect to Ztor, only two values are needed. No text added. 1167. Lines Please explain why a value for Ztor is needed in the RJa-based models when it was not used as a term The term "RJs-based models" refers to the 616-in these models, i.e .. how can "one Ztor value" be used if the models do not include Zlor at all? common-form models. not lo the candidate 618 GMPEs. The process is to generate ground motions from the candidate GMPEs and then refit them with a common-form model. To generate the GM from the candidate GMPES that use RRuP, a ZTOR value needs lo be defined When we fit the common-form models using RJB, there is no ZTOR term. Clarifying text added 1168. Line Please correct the spelling of the second occurrence of "PVNGS." Done 629 1169. Line Please check whether the intent of this sentence would be more clearly expressed if the final clause Done 632 were included inside the parentheses. 1170. Line It appears from Eq. 6.4-4 that it is the contributions to the Euclidean distance squared that are Done 633 weighted by the weights from Eq. 6.4-7 (not the contributions to the Euclidean distance itself. as stated). Please correct or clarify. 1171. Lines The phrase " ... then the point that corresponds to the position of the candidate GMPEs is selected" is Done 689-confusing. Please rewrite this phrase to make its meaning clearer. 690 1172. Line Please correct the typo. Le. "two week" should be "too weak." Fixed 704 1173. Line Please provide a brief statement. or reference. that describes a "Voronoi-diagram" or the section(s) of Reference added 706 an appendix where such a reference or definition can be found 1174. Lines Is it true that all of the models within a given Voronoi cell do not really represent the same level of The cells are small enough (range less that 719-probability on the ground-motion distribution? If this is true. the use of equal weights is an assumption. 0. t In units in the Sammon's map) that we 720 Please justify the use of equal weights to determine the weighted mean hazard in each cell. can use equal weight. To assign probabilities would require that we use the prior and in some cases we set weights not based on the prior. 1175. Line Please discuss the common form model that corresponds to the highest hazard curve in Figure 6.4.4-4 Discussion added 726 and explain why it falls so far above the cluster defined by the rest of the models in the same cell. 1176. Lines Although the distribution of HW models is nearly uniform for the DCPP representative models, the Discussion added 735-distribution of the hazard might not be, depending on what Voronoi cells received the higher HW 736 models (i.e., the high-hazard cells or the low-hazard cells). Please justify that the mean hazard is not biased by the random selection of HW models. 1177. Lines Please clarify what "results" are not sensitive to the discretization size of the Voronoi cells (i.e .. the Text revised to define "results". 762-weights or the hazard). It is possible that the hazard will be sensitive to the size of the cells (e.g .. what If only one cell was used, then, by our 763 if only one cell were used?). approach the selected model would correspond to the mean hazard for eaual weights (because we selected the model closest to the mean hazard). We note that, with very large cells (or just one big cell), equal weights would not be appropriate. We used equal weights because our cell size was small enough as described in Comment #1174. 1178. Lines Please show an example contour plot in Chapter 6 for those readers that do not care to read Appendix Reference Chapters 8 and 9 that include 804-H. example of those figures, in addition to 807 Appendix H 1179. Lines Please show an example distribution plot in Chapter 6 for those readers that do not care to read Sentence removed -the figures and 808-Appendix H. reference to appendix Hare included in the 809 sections that follow 1180. Line Two consecutive figures are called "6.4.5-8." Please check and renumber as needed. Fixed 879 1181. Lines The sentence starting with "Randomizing" appears to be unconnected to the rest of the paragraph. Sentence removed. 927-Please expand or rewrite this sentence to better convey is meaning. 928 1182. Line Please see the general comment regarding the documentation of the directivity model evaluation. See our answers above 929 1183. Lines If the standard deviation represents the variability in the hypocenter location, please explain what the Clarification added 937-median (or should it be the mean) represents (e.g .. the bias?). 939 1184. Lines Please justify why it is not necessary to include Ztor as a directivity parameter for those events that do Watson-Lamprey did not find the need to 951-not rupture to the surface (e.g., the directivity effects for M5.5-6.5 events that the GMPEs were include Ztor in her formulation of the 953 evaluated for). simplified model. Because we are not incorporating this model, we have not looked at more refined scaling of directivity effects with depth. No chanae in the text. 1185. Lines Please include sufficient details of the Tl Team's evaluations of the technical merits and limitations of Addressed in Tier 1 comments 962-the simplified directivity mode I in support of the decision to adopt this model for use in hazard 964 calculations (as also requested in one of the general comments). 1186. Lines Please explain the basis for the evaluation that the simplified directivity model is a reasonable Addressed in Norm's write up "Evaluation of 965-approach for capturing directivity effects (e.g., was the hazard using the CY14 directivity model and alternative directivity models for DCPP" 967 random hvoocenters comoared to that usino the simolified model?). dated march 9, 2015 1187. Lines Please identify which event NGA EQID 1017 represents and why it is justified to remove this event I* PGA. EOID 1017 I 981-because the event-terms of the GMPEs are not consistent. 01 982 001 " § 0.001 .... .. {. .. .,, *! 0 ... : :ff;#; c.. 0.0001 .. ... -0.00001 ;':' .-.j :) 0 0.000001 1 10 100 1000 Auptute Distance \kH1j The data from event 1017 are primarily at large distance. As a result the event term caoture the difference in distance scalino. This leads to an inconsistency for the event term correction of the within-event residuals of the BSSA model. It's not a problem for CY14 because of their fitting procedure. The BSSA within residuals are outliers, leading the path PhiSP-r to be larger than the ergodic standard deviation. The Ti Team judged that the trade off may be unreliable and removed for the path-effects evaluations 1188. Lines Please explain why there is a difference in plotted values between Figure 6.6.1-2 and Figure 7.4.1-6. The figure in Chapter 7 was the correct one. 990-Figure 6.6.1-2 is now corrected (Rev.2) 991 1189. Lines There seem to be two sets of LN values being given in this section. The -0.5 and +0.1 LN units listed Clarifications added 1008-in the previous paragraph appear to be biases in the log PSA values, whereas, the 0.32 and 0.35 LN 1009 units given in this paragraph appear to be standard deviations. Please make the distinction between these two sets of values clear in the text. Please also be more specific about what "numbers" (the biases or the standard deviations) the Tl Team considers to be "reasonable." 1190. Lines The use of the telTl'l "proponent model" or "proponent method" is confusing. since it can be interpreted Word "proponent" removed. In some 1015 as a model or method being proposed by a Proponent Expert (PE). If these models and methods are instances. it has been substituted with proposed by the Tl Team. please replace "proponent" with Tl Team" in this line and elsewhere in alternative" Section 6.7 where the term is used. 1191. Line Please delete the phrase "with similar rake, dip, width," which is incorrect based on the contradictory This refers to what constituted an individual 1036 and apparently correct description given on Line 1039. rupture. Clarifying text added 1192. Line Please note that this statement appears to contradict the phrase on Line 1036. which has been Done 1039 interpreted to be a typo in a previous comment. 1193. Lines The sentence "The ground motions from the 2011 Fukushima-Hamadori earthquake are evaluated Sentence deleted 1064-using the SRSS method in Section 9.1.5.2." appears to be disconnected from the sentences before 1065 and after it. It is also ambiguous what the "Therefore ... " at the beginning of the next sentence is referrino to. Please rewrite these sentences to better convev their intended meanino. 1194. Line Please explain which complex rupture "Complex Scenario 18" represents. Done 1076 1195. Line Please explain which splay rupture "Splay Scenario 1C" represents. Done 1096 1196. Line Please confirm whether "Model A should be included in the title to Table 6.4-2. Done 1300 1197. Line Please confirm that the CB14 GMPE is plotted correctly in the lower plot (M6.6. SS, PGA). PSA is correct. This reflects the difference 1343 in high-frequency spectral shape in CB 14 for Vs30 = 760. This is seen clearly in the response spectral shape comparisons. No change in text. 1198. Line Please confirm that the GMPEs are plotted correctly in this plot. For example, CB14 appears to have a This reflects the coarse sampling of the 1354 hinge or kink at M7, but its magnitude scaling term does not. magnitude. A finer sampling would show a smoother M-dependence. Caption auomented 1199. Line Please identify the models listed in the legend to Figure 6.2.3-1 by their correct acronyms (i.e., ASK14 Not done, original figure not available to us 1359 instead of ASK). at this time 1200. Line Please identify the models listed in the legend to Figure 6.3.1-2 by their correct acronyms (i.e., ASK 14 Done 1380 instead of ASK). 1201. Line Please identify the models listed in the legend to Figure 6.3.2-1 by their correct acronyms (i.e., ASK14 Done 1386 instead of ASK2014). Please also justify in the text why it is acceptable for the predictions from the proposed HW models to not encompass the predictions from all of the GMPEs. 1202. Line Please identify the models listed in the legend to Figure 6.3.2-2 by their correct acronyms (i.e., ASK14 Done 1391 instead of ASK2014 ). Please also justify in the text why it is acceptable for the predictions from the proposed HW models to not encompass the predictions from all of the GMPEs. 1203. Line Please identify the models listed in the legend to Figure 6.3.2-3 by their correct acronyms (i.e., ASK14 Done 1396 instead of ASK2014 ). Please also justify in the text why it is acceptable for the predictions from the proposed HW models to not encompass the predictions from all of the GMPEs. 1204. Line Please identify the models listed in the legend to Figure 6.3.2-4 by their correct acronyms (i.e., ASK 14 Done 1401 instead of ASK2014). Please also justify in the text why it is acceptable for the predictions from the proposed HW models to not encompass the predictions from all of the GMPEs 1205. Line Please identify the models listed in the legend to Figure 6.3 2-5 by their correct acronyms (i.e .. ASK 14 Done 1406 instead of ASK2014). 1206. Line Please identify the models listed in the legend to Figure 6.3 2-6 by their correct acronyms (i.e .. ASK 14 Done 1409 instead of ASK2014). 1207. Line In Figure 6.3.2-11, please justify in the text why it is acceptable for the predictions from the HW models Pointed out that for sites over the surface 1432 to not encompass all of the predictions from the simulations. projection of the fault plane the models to encompass the majority of predictions from simulations, but for sites located off the surface projection (Rjb>O) the simulations produce values larger than the model. The HWRjbTaper is based on the empirical constraints captured in the published GMPEs in which the HW effect 1208. Line In Figure 6.3.2-12, please justify in the text why it is acceptable for the predictions from the HW models See 1207 1438 to not encompass all of the predictions from the simulations. 1209. Line In Figure 6.3.2-13, please justify in the text why it is acceptable for the predictions from the HW models See 1207 1444 to not encompass all of the predictions from the simulations. 1210. Line In Figure 6.3.2-14, please justify in the text why it is acceptable for the predictions from the HW models See 1207 1448 to not encompass all of the predictions from the simulations. 121 t. Lines The plot for the Idriss model is labeled "114," inconsistent with "ld14" elsewhere in the chapter. Please done 1472 modify for consistency. (Figure 6.4.1-4a). 1475 (Figure 6.4.1-4b). 1478 (Figure 6.4.1-Sa), and Line 1481 (Figure 6.S.1-Sb) 1212. Line In Figure 6.4.3-3, please explain the meaning of "NGAW2PV-MED MODEL A" in the upper-left corner of Label removed from plot 1S29 the plot. 1213. Line In Figure 6.4.4-1, please explain the meaning of "NGAW2oc-MEo" in the upper-left corner of the plot. Label removed from plot 1SS2 Please also explain what the different colors for the solid circles representing the GMPEs and their epistemic uncertainty refer to and what the orey circles represenl. 1214. Line In Figure 6.4.4-2, please provide a legend for the color contours and explain the meaning of the grey Done 1557 ellipses and circles. 1215. Line In Figure 6.4.4-4, please define the axes labels and explain the meaning of "T001 DCCP4 MODELA" Done 1567 in the upper-right corner of the bottom plot. 1216. Line The caption states that the GMPEs are in black, but the legend indicates a different color. Moreover, Done 1586 the color assignments differ from those in Figure 6.4.5-2a. Please modify for consistency between (Figure caption and legend, and between the a and b parts of the figure. 64 5-2bl 1217. Line In Figure 6.4.5-7, please justify why it is acceptable for the predictions from the proposed model to not Sentence added to expand on the 1623 encompass all of the predictions from the candidate GMPEs. The inference is that there is less than discussion 5% confidence in those GMPE predictions that fall outside of the limits of the model. 1218. Line In Figure 6.4.5-8, please justify why it is acceptable for the predictions from the proposed model to not Sentence added to expand on the 1630 encompass all of the predictions from the candidate GMPEs. The inference is that there is less than discussion 5% confidence in those GMPE predictions that fall outside of the limits of the model. 1219. Line In Figure 6.5.1-3, please explain what directivity model is used to make the plot and where the Done 1666 epicenter and/or hypocenter is located on the fault. 1220. Figure Please label the vertical axis and explain the meaning of the term "ground motion factors" in the Done 6.7.2-2 caption. 1221. Figure Please identify the GMPEs associated with the respective colors. and the meanings of the different Done 6.7.2-3 styles of grey lines, and make improvements to the legibility of the figure (note also that the figure did not appear in its entirety in the supplied PDF version). Also please explain the meaning of the term "Qround motion factors" in the caption. 1222. Figure Please label the vertical axis and explain the meaning of the term "ground motion factors" in the Done 6.7.2-5 caption. 1223. Figure Please identify the GMPEs associated with the respective colors. and explain the meaning of the term Done 6.7.2-6 "ground motion factors" in the caption. CHAPTER 7-GMC Models for the Sigma: Overview and Methodology 1224. Lines Please note that by the sigma terminology of Al Atik et al. (2010) "single-station within-event" standard Notation changed throughout the report and 8-9 deviation should be "single-site within-event standard deviation. Please consider consistently using appendices the terminology of Al Atik et al. (2010). 1225. Line 74 Please consider assigning the Zhao et al. (2006) model the acronym used in Chapter 6 (i.e .. ZH06) as Done shorthand in the remainder of the chapter. 1226. Line 84 Please add the missing words in this sentence (which currently reads "and chose through the"). "to smooth" added before "through" 1227. Line 87 Please consider revising "smooth" to "constant." "Smooth" changed with period-independent" 1228. Line Please consider using a different word than "proponent" on this line and elsewhere in the chapter to Proponent changed to "candidate" 155 explain the different Tau and Phi models so as not to confuse them with models that have been proposed by Proponent Experts (PEs). 1229. Line Please rewrite the sentence beginning with "The values .. " to better convey its meaning. The Sentence is modified now (see answer to 177 second half of this sentence appears to be incomplete. comment 197 1230. Line Please correct the figure citation. which should be to Figures 7.2.3-2 and 7.2.3-3 (not "7.2.3-3 and Fixed 183 7.2.3-3"). 123t. Line Please replace the term "proponent" with the term "candidate" to be consistent with terminology used Done, see comment t 55 191 elsewhere in the report. 1232. Line Please replace the term "proponent" with the term "candidate" to be consistent with terminology used Done, see comment t 55 195 elsewhere in the report. 1233. Line Please rewrite the final sentence of the paragraph to clarify its meaning (i.e., a "value" cannot be Sentence rewritten as "The standard 197 similar to a "model," so it is not clear what point the sentence is trying to convey). deviation of r2 was fitted to a constant, period-independent function. The period-independent constant estimate is similar to the central model" 1234. Line Please change crss to cr,. Done 202 1235. Line Please replace the term proponent" with the term "candidate" to be consistent with terminology used Done, see comment 155 207 elsewhere in the report. 1236. Line Please describe the type of distribution used in the simulation. Normal distribution. Sentence added 232 1237. Line Please indicate whether "Dawood et al. (2015 )" should be replaced with "Dawood et al .. 2014 -in The correct citation is (2014) and is already 269 press" and, if not. please provide the reference to the former. included in the reference list. The notation "in press" has been removed from the text 1238. Lines This paragraph appears to be contradictory and the Tl Team decision to use a magnitude-independent Sentence introduced to state that, upon 271-Phi_ss is not well supported by the first sentence in the paragraph and the results in Figures 7.3.2-1. visual examination of the M-binned PhiSS . 275 Please expand this paragraph to better discuss and justify the decision to use a magnitude-the Tl T earn judged that is no significant M-independent model for Phi_ss. dependence seen consistently at most of the available periods 1239. Line Please correct the inconsistency between the phrase "shown .. for four spectral periods" and the list Done 273 "(PGA, 0.1,0.5, 1.0,3.0 sec)," which (like the figure itself) includes five periods (PGA in addition to the four aiven spectral periods). 1240. Line Please explain why the Phi_ss values of the GLOBAL datasets for each GMPE are only shown for five The reasons are described in Chapter 5. 276 periods in the figures and indicate, if only five values were used in the analysis. why Phi_ss values for The Lin et al. dataset in our possession had the other periods are not used. only those five periods. 1241. Line Please describe how CV(4>ss) = 0. 12 was derived. It is explained in Section 7 .3.1. A cross 320 reference has been added 1242. Line Please avoid the use of the first person us." Done 388 1243. Line The statement that the between-event residuals were provided by the NGA-West2 developers is Sentence modified to clarify the difference 396 contradictory lo the statement on Lines 404-405 that the Tl Team calculated the residuals. Please in the approach between PhiSS (NGA rewrite the text to remove this contradiction. residuals) and PhiSP-R(new residuals from data recorded at Arizona stations not included in NGA-West2) 1244. Line Please avoid the use of the first person "we." Since the use of first person has appeared several times Done 404 in this chapter, please search the entire chapter for other uses of first person and convert them to third oerson. 1245. Line This statement is confusing and again suggests that the between-event residuals provided by the See answer to 1243 407 developers are perhaps being used. Please consider rewriting or expanding this entire section to make the orocess of develooina the LD sinale-path standard deviations less confusina. 1246. Line Please change oW;i to oW;1k Done 415 1247. Line In the Figure 7.2.4-4 caption, please consider replacing the word "proponent" with candidate" to be Done 730 consistent with how these models are referred to elsewhere in the report. 1248. Line In the Figure 7 2 5-1 caption, please consider replacing the word "proponent" with candidate" to be Done 744 consistent with how these models are referred to elsewhere in the report. 1249. Line Please explain what is the first issue. Verbiage modified to "An issue associated 469 to" There is no first issue in the text. 1250. Line In Figure 7.3.2-3, please consider showing the periods with average "no-Lin et al. Data" to show that Done 784 these values are also bracketed by the low and high proposed values. 1251. Line In the Figure 7.3.3-1a caption, please describe what the black solid and dashed lines represent. Also. Done 812 in this and many other figures there are error bars on the symbols, but no mention of them in the legend or the caption. Please define the meaning of the error bars in this and other figures in this chapter and for similar fioures elsewhere in the report where thev mioht appear 1252. Line In the Figure 7.3.3-1b caption, please describe what the black solid and dashed lines represent. Done 821 1253. Line In Figure 7.4.2-1, this figure clearly demonstrates that the assumption that the standard deviation is An expanded discussion on lack of data to 898 constant at low and high periods is totally unsupported by the data (note that the values at 0.2 sec derive Phi SP-R above 2 seconds has were not used because of reliability issues). Please further justify in the text why it is appropriate to been added extrapolate the first and last values as constant values to lower and higher periods and why the uncertainty should not become larger at low and high periods given this added uncertainty. Discussion expanded. CHAPTER 8-Median GMC Models: DCPP Sources 1254. Section There does not appear to be a reference to Figure 8.2-3 Please check and add a reference lo this Fixed, now is quoted in Section 8.2.2 8.2.2, figure if one is missing. general com me nt 1255. Lines Please explain the bases for the values used to define the three branches and their weights included Sentence expanded 60-61 in the second node of Figure 8.2-3. 1256. Line This is not necessarily true for the Akkar et al (2014a,b) and Bindi et al. (2014a,b) GMPEs that were Bindi 2014 is not a candidate GMPE for 100 developed using subsets of the RESORCE database and with at least some interaction between them DCPP, therefore the issue is not pertinent under the auspices of the SIGMA project. Please clarify this statement. to Chapter 8. Some clarifying text has been added. 1257. Line Please add the missing word "models" after "common-form". Fixed ("models" added) 125 1258. Line Please improve clarity by adding a sentence break after the word "model." Fixed 167 1259. Lines Please reference where in the report the evaluation of Id 14 was done to determine that it was Reference to Section 6.2.1 is already cited. 293-unreliable for RRuP < 3 km at large magnitudes. Text revised to make this point clearer. 295 1260. Line Please indicate what models are being compared in Figure 8.4-8. The discussion references both the Description added 302 common-form models and the candidate GMPEs and it is not clear which is being referred to when not exolicitlv stated in the text. 1261. Line Contrary to this sentence. curves corresponding to the epistemic uncertainty are not included in Figure Same issue applied lo Figure 8.4-8 which 310 8.4-9. Please add the curves or modify this sentence to remove reference to epistemic uncertainty. has been changed so lo show the candidate GMPEs with the epistemic uncertainty. Sentence is now consistent with figure 8.4-8. Figure 8.4-9 has been fixed and now the epistemic uncertainty curves are shown for M 6.5 and 7.5 in addition to M5.5 1262. Line Please provide evaluations or provide a cross reference in support of the conclusion that "differences Change "will to "may to make this less 355 in the magnitude and distance scaling wil I also impact the range of the hazard." definitive. No evaluations are provided. 1263. Lines Please explain what will need to be done if in the future the hazard model is changed. For example, Text revised (also added to Chapter 15, 360-will an evaluation of the GMC model need to be redone because its validity was based, in part. on the section on DCPP application) 361 hazard calculated from a specific hazard model (i.e., hazard-calibrated)? If that is the case. it is important that such a caveat be clearly communicated in the report. Please note that there are other instances in this and other chapters where hazard was invoked as demonstrating that the range in the models is adequate, which should also be included as part of this comment. 1264. Lines Please explain why the versions of the candidate GM PEs with added epistemic uncertainty are not That's already shown in Figures 8.4-18 and 367-considered in the comparison. 19. No change in the text. 370 1265. Line Figure 8.4-7 is missing or skipped over. Please correct this oversight. Done 388 1266. Figure Please correct the weight for "Sim_DC-MED, (i.e., shouldn't it be 0.25?). Done 82-2 1267. Line In Figure 8.4-1, please provide labels for the color legend bars and define what the light grey ellipses Done (besides for bar labels) 522 and points represent. 1268. Line In Figure 8.4-2, please provide labels for the color legend bars and define what the light grey ellipses Done (besides for bar labels) 533 and points represent. 1269. Line In Figure 8.4-3, please explain what DCPP Model A is, given that there appears to be only one DCPP Caption augmented to clarify the meaning 547 model 1270. Line In Figure 8.4-6, there does not appear to be any "dashed black" lines. Please revise the caption to Dashed black lines are already in the figure. 569 refer to the actual color scheme used in the figure. No change applied 1271. Line In Figure 8.4-8, there does not appear to be any "dashed black" lines. Please revise the caption to Dashed black lines are already in the figure. 580 refer to the actual color scheme used in the figure. No change applied 1272. Line In Figure 8.4-9, there does not appear to be any "dashed black" lines. Please revise the caption to Dashed black lines are already in the figure. 594 refer to the actual color scheme used in the figure. No change applied 1273. Line In the Figure 8 4-14 caption, please describe what models the phrase "individual models" refer to Qualifier "representative suite of common-645 form models" used instead than "individual models" 1274. Line In the Figure 8.4-15 caption, please describe what models the phrase "individual models" refer to. Qualifier "representative suite of common-651 form models" used instead 1han "individual models" 1275. Line In the Figure 8.4-16 legend, please refer to the various models by the acronyms used throughout the Done 656 report (e.g., ASK14 instead of ASK). 1276. Line In the Figure 8.4-17 legend, please refer to the various models by the acronyms used throughout the Done 662 report (e.g., ASK14 instead of ASK). 1277. Line In Figure 8.4-18, please define what the light grey lines represent in the legend or the caption. Explanation is in the caption 665 1278. Line In Figure 8.4-19, please define what the light grey lines represent in the legend or the caption. Explanation is in the caption 670 CHAPTER 9-Median GMC Models: PVNGS Sources 1279. Line 38 Please follow the standard practice of numbering figures in the order in which they are first called in Figure 9. 1-2 is correctly called on line 37 in the text, which is not the case with the figure called on this line. the Draft Rev1 documents. No change in the text 1280. Line 54 Chapter 6 of this report and the report on the SSC model use the term "virtual faul1". rather then Fixed "pseudo fault." Please revise for consistency with those other usages. 1281. Lines The Akkar et al. (2014a,b) and Bindi et al. (2014a,b) GMPEs were developed using subsets of the Paragraph added to clarify this point 74-75 RESORCE strong-mo1ion database under the auspices of the SIGMA project. Please indicate that these two models are likely correlated, although perhaps not to the extent of the NGA-West2 models. Please also note that this is not an issue, since epistemic uncertainty was applied to these models as well as to the NGA-West2 models. 1282. Line Please specify the type of "residual" (i.e .. between-event). A qualifier was already applied to each 108 "residual" entry in the Draft Rev1 document. No chanae in the text 1283. Lines The sentence beginning "The limitation .. " is confusing. Please reword it or expand it to make its We assume this is line 149 Sentence 173-meaning clearer. reworded. 174 1284. Line Please make it clear which mechanism each of the weights refers to. We assume this is line 163. Sentence 187 reworded. 1285. Line Please correct the figure reference; the reference to Figure 9.1-10 should actually be to Figure 9.1-9. We assume this is line 232. Figure 256 reference fixed. 1286. Line Please correct the figure reference on this line (it should be 9.1-19). The comment does not match the line 371 number in Draft Rev1 Chapter 9. We do not understand comment 1287. Lines Please indicate where the technical justification and bases for these statistical weights are given (i.e .. The comment does not match the line 475-Appendix P). number in Draft Rev1 Chapter 9. 476 We highlighted references to Appendix P already in the text 1288. Lines The stated justification seems weak; there are few recordings at 200 to 400km distance range in the Paragraph expanded to clarify this 478-ground-motion database. On the other hand. it would appear that there is no need to consider comment 481 directivity because its effect, as modeled in CY14, is zero at such large distances. Please revise to clarify the justification for the Tl Team's judgment. 1289. Line In the heading of the last column in Table 9.1-1, please replace the term "SFO" with "SOF" to Done in Chapter 8 and 9 545 represent style of faulting. 1290. Line In Figure 9.1-2a, please label the color legend bars and describe whal the light grey ellipses and Done (besides for bar labels) 557 circles are on the plots. 1291. Line In Figure 9.1-2b, please label the color legend bars and describe whal the light grey ellipses and Done (besides for bar labels) 567 circles are on the plots. 1292. Line In Figure 9.1-3a, please label the color legend bars and describe whal the light grey ellipses and Done (besides for bar labels) 577 circles are on the plots. 1293. Line Figure 9.1-3b. please label the color legend bars and describe what the light grey ellipses and circles Done (besides for bar labels) 587 are on the plots. 1294. Line Please provide a specific reference to "Akkar et al." Unique subset ID is used (EUR*v Meo) 607 1295. Line In Figure 9.1-8, the plots do not appear to have any "dashed black lines. Please revise the text to Dashed black lines are already in the figure. 637 better describe the lines. No change applied 1296. Line In Figure 9.1-9, the plots do not appear to have any "dashed black" lines. Please revise the text to Dashed black lines are already in the figure. 645 better describe the lines. No change applied 1297. Line In Figure 9.1-10, the plots do not appear to have any "dashed black" lines. Please revise the text to Dashed black lines are already in the figure. 653 better describe the lines. No change applied 1298. Line In Figure 9.1-11, the plots do not appear to have any "dashed black" lines. Please revise the text to Second part of the question is now 661 better describe the lines. Please also further justify in the text why it is acceptable for some of the addressed in Chapter 6 in response to Tier predictions from the GMPEs to fall outside of the range of the representative models at some periods. t comments. Note the concern in previous comments of using only the hazard distribution alone to justify the range in the representative suite of models. Dashed black lines are already in the figure. No chanae aaalied 1299. Line In the Figure 9 1-13 caption, please describe what is meant by "individual models," and consider First part clarified, 709 making changes such that the upper and lower parts of the figure have the same vertical scale. Second part will not be done for this revision 1300. Line In the Figure 9.1-14 caption, please describe what is meant by "individual models." Done 714 NOTE: in this and other similar cases, the exact figure matching the comment line was not found, but corrections have been applied to all figures captions where applicable 1301. Line In the Figure 9 1-15 caption, please describe what is meant by "individual models." Done 718 1302. Line In the Figure 9.1-16 caption, please describe what is meant by "individual models." Done 724 1303. Line In the Figure 9.1-17a caption, please describe what is meant by "selected models." Please consider Done 729 using a consistent set of tenninology for the different types of models that are described throughout the report to make it less confusing to the reader. Please also use a consistent set of acronyms in the leoend (e o, ASK14 instead of ASK). 1304. Line In the Figure 9.1-17b caption, please describe what is meant by "selected models." Please also use a Done 738 consistent set of acronyms in the legend (e.g., ASK14 instead of ASK). 1305. Line In the Figure 9.1-18a caption, please describe what is meant by "selected models." Please also use a Done 742 consistent set of acronyms in the legend (e.g., ASK14 instead of ASK). 1306. Line In the Figure 9.1-18b caption, please describe what is meant by "selected models." Please also use a Done 748 consistent set of acronyms in the legend (e.g., ASK14 instead of ASK). 1307. Line In Figure 9.1-19, please use a consistent set of acronyms in the legend (e.g., ASK 14 instead of ASK). Assuming it refers to Figures 9.1-17 or 9.1-759 18 Done 1308. Figure Please correct the abbreviation for the Idriss (2014) model to be consistent with usage elsewhere in Fixed 9 2-t the report. CHAPTER 10-r Model Logic Tree for both DCPP and PVNGS 1309. Lines Please also mention that the standard deviations of ASB 14 and Bi14 are independent of magnitude. Done 25-26 which was an important property of the models that the Tl Team used to reject them. 1310. Line 38 Although the use of the term "proponent" in this context is technically correct, it is inconsistent with the Done term **candidate" used throughout the report to identify such proponent models Please consider replacing "proponent" with "candidate" to be consistent with the description of such models throughout the report. 1311. Line 47 Please add the term "scaled" before "Chi-square distribution." Done 1312. Lines The three-point approximation scheme (as described in Appendix P) applies (0.2, 0.6. 0.2) weighs to Discussion added in Appendix P 51-53 the (5th, 50th, 95th) percentiles. Please explain the appropriateness (or point to a place where such explanation was given) of giving a 0.6 weight to the central branch representing the mean (which may not be the 501" percentile of a Chi-square distribution} CHAPTER 11-cj> Model Logic Tree: DCPP 1313. Line 27 Please clarify if interpolation and extrapolation were also needed for the California-only data subset, Done. The issues does not exist for the which includes data at the full set of spectral periods. California data 1314. Line 53 Statistical evaluation of the standard error of .Pss was not given in Appendix P. Please verify and correct Reference to Appendix P is now removed the cross reference as needed. 1315. Lines Please refine this paragraph to give a clear and accurate summary of the approach described in Entire paragraph rewritten 53-58 Section 7.3.1. 1316. Line 64 Please qualify the term "correlated" in a way that is similar to Lines 4-5 of Chapter 12. Done 1317. Line 71 Please consider revising the term "intra-event" to "within-event" to be consistent with the terminology Done throughout the chapter generally used throughout the report. 1318. Lines Please define the level of significance for the presumed departure from normality. It might be obvious Sentence added to clarify this point 78-79 to the Tl Team, but not necessarily to the reader, that a point falling outside the 95% confidence and 88-interval can be considered to depart from normality at the 5% level of significance. Besides, others 89 mioht consider "sionificant" to be at the 10% level of sionificance 1319. Line Please be specific whether the same weights of the mixture models that were found to be appropriate Discussion expanded to clarify this point. 105 for CY14 are "similar" or the "same" as found for ASK t4. The same weights are adequately fit the data. 1320. Lines Please provide a context for this paragraph. Paragraph deleted 108-112 1321. Line Please insert a space after 4'-Done 127 1322. Line Please consider revising the term "intra-event" to "within-event" to be consistent with the terminology Done (See reply to 1317) 133 used throughout the report. 1323. Line In the Figure 11-2 caption, please consider revising the term "intra-event" to "within-event" to be Done 188 consistent with the terminology used throughout the report and define the meaning of the term "normalized." Please also define the solid and dashed red curves. In addition. note that panel b) is stated as being for T=2 sec, but the y-axis label indicates it is for T=0.5 sec. Please correct this inconsistency. 1324. Line In the Figure 11-3 caption, please describe what type of "residuals" are referred to in this figure. Done 191 Please also define the solid and dashed red curves. 1325. Line In the Figure 11-4 caption, please describe what type of "residuals" are referred to in this figure. Figures not revised due to paucity of time 194 Please also define the solid and dashed red curves and provide the missing red curves on the right plot. 1326. Line In Figure 11-5, both of these plots appear to be incomplete and the left plot is not consistent with the Figures not revised due to paucity of time 201 right plot. Please correct these plots to be consistent with other similar plots in the chapter. 1327. Line In Figure 11-6, both of these plots appear to be incomplete and the left plot is not consistent with the Figures not revised due to paucity of time 212 right plot. Please correct these plots to be consistent with other similar plots in the chapter. 1328. Line In Figure 11-7, both of these plots appear to be incomplete and the left plot is not consistent with the Figures not revised due to paucity of time 218 right plot. Please correct these plots to be consistent with other similar plots in the chapter. CHAPTER Models Logic Tree: PVNGS 1329. Lines The first paragraph appears to be awkwardly placed. Please consider placing this paragraph in a more Paragraph moved to second position. 3-5 appropriate place in the chapter. 1330. Line 45 Please remove the reference to DCPP, since this chapter addresses the Phi model for PVNGS. Done 133t. Line 69 Please correct "biased-corrected" to "bias-corrected." Done 1332. Line 90 Lines 486 and 487 on Page 7-16: CV=0.17 of .PsP-* was based on the variability and the mean of Paragraph rewritten for clarity estimates for the four individual GMPEs. Please clarify or correct the statement "based on sample size" in the case of <J>_. .*. 1333. Line Please replace "02" with "0.2." Done 146 CHAPTER 13-Total Sigma Model 1334. Genera The use of the term "total sigma" instead of the more accurate "total single-site sigma" tends to neglect The term is intentionally used generically as I the fact that only a single-site sigma model was adopted. Please consider replacing the term "total two types of total sigma values are in fact sigma" with "total single-site sigma" to emphasize this point. generated, one for the single station sigma and one for the similar path to a region. These are indicated by the appropriate subscripts on o. No chanoe needed 1335. Line 7 Although the Greek letter "1p" and the Greek symbol "fj>"both represent Phi, it is common in engineering q> was replaced with ¢ seismology to use the latter, which has also been used elsewhere in this report to represent Phi. Please select one of these lettersfsymbols to represent Phi and use it consistently throughout the report in order to avoid confusion. 1336. Line 10 Eq ( 13-1) is very generic and does not represent the actual aleatory variabi lily models that are The equation is intentionally generic as proposed. Please consider replacing this equation with two equations: one that represents the total described in the subsequent paragraphs. sinole-site sioma without path terms and one that reoresents the total sinole-site sioma with path (see response to 1334} terms, as discussed in the text that follows the equation. 1337. Lines Although the use of only a total [single-site) standard deviation epistemic logic tree is conceptually fine. They would use the phi and tau models 30-31 it appears to prevent the ability to test the sensitivity of the hazard results to the individual between-given in chap 10, 11, and 12 event and single-site within-event epistemic uncenainty models. Since sensitivity to each type of model is provided in Chapter 14, please explain how someone else can test this sensitivity given that the final model presents only a sinqle total [sinqle-sitel siqma model 1338. Line 55 Please replace the term "cumulative distribution" with the more accurate term "'cumulative distribution Done function" 1339. Line 57 Please add a sentence to explain the utility of Eq (13-3). The sentence below has been added The cumulative distribution function is used to develop the discrete approximation used in the logic tree formulation to represent the uncertainty in the variance parameter 1340. Line 61 Please correct the missing factor of two in Eq ( 13-5) (this typographical error is noted here just as a Done reminder; it has already been noted by the Tl Team). 1341. Lines Please further describe these analyses or provide a reference where the results of these analyses can Appendix P. Section P.3 62-63 be found. 1342. Line 66 Please correct a possible typo: should oss be changed to Corrected 1343. Line 75 Please correct a possible typo: should be changed to oss? Corrected 1344. Line 77 Please correct the typo ("bi-linear") and add the missing word (i.e., missing "to" in "leads to"). Done 1345. Line 79 The Tl Team responded to PPRP's Comment 175 by adding the sentence "Appendix P presents They are provided at the bottom of page P-typical exam pies of the calculations." However, such exam pie calculations were not given in Appendix 1 P. Please provide these missing calculations. 1346. Lines To be consistent with the usage in the embedded table on Line 93, please consider adding subscript Subscript and consistent notation is used 89 and "SS" to symbol o. 90 1347. Line 90 Please assign the embedded table a number and a title so that it can be referenced by table number if Fixed throughout the Chapter needed, and correct any subsequent table numbering as necessary. 1348. Lines Please explain why directly computed CT" at magnitudes between M 5 and M 7 at 0.1 units were not The tri-linearfolTn for sigma is linear 98, 99 and used in fitting Eq (13-8)? interpolation. 100 1349. Lines Please provide a reference for the statement beginning "Minimization of the difference ... ". Reference provided (Appendix I of EPRI, 102-2004) 103 1350. Line Please check the correctness of the reference to Section 13.1; should it be Section 13.2? Yes. Corrected 118 1351. Line Please clarify whether "the method refers to the semivariogram analysis method (Le .. the current Done 154 sentence construction leaves some ambiguity). 1352. Line The Tl T earn presented its evaluation and decision on the modeling of the effects of spatial correlation Paragraph inserted to address the Tl 160 on cr" for the magnitude-independent cr" model only. Please also provide discussions for the Team's evaluation of the magnitude-magnitude-dependent ass models. independent model. 1353. Line Please repair the typos on this line. Done 184 1354. Lines Please indicate in each figure which branch includes the spatial-correlation effect on oss. The spatial correlation effect is not applied 267, on a branch or branched, but by skewing 270 the weights towards the upper branch. Text and added 273 CHAPTER 14--Hazard Sensitivity 1355. Lines It appears awkward to state that the hazard sensitivity analyses for the final GMC model was done on Caveat integrated with the edits done in 7-8 preliminary versions of the SSC models without providing some sort of caveat. This can be avoided by response to previous comment 682 stating that it is the responsibility of the individual NPPs to conduct thorough sensitivity analyses for their individual sites and that the sensitivity results provided herein are for demonstration purposes and for purposes of making hazard-informed decisions. 1356. Line 60 There is no mention of deaggregation in the introduction to this chapter. Please introduce this concept Sentence inserted in the general and discuss what it is used for in the introduction to the chapter prior to presenting the deaggregation introduction results. 1357. Line 81 Please add the term "mean" before "hazard level" to be clear that the results represent the mean and Done, clarification added in the general not some other fractile (e.g., the median) hazard. Hazard is used without prefacing it by mean many introduction times throughout the chapter. If mean is not added to all of the instances where the hazard level is mentioned, then please state that this is the case for the remainder of the chapter in order to avoid confusion. 1358. Line 88 Please consider rewriting the caption (i.e., the "hazard at hazard" juxtaposition somewhat obscures the Captions changed. Now they read meaning). "Deaggregation of reference site condition (Vs30 of760 mis) hazard at mean annual. .... " 1359. Line Please define the term "sensitivity case" and be as specific as possible about what figure(s) are being Done 103 referenced in the discussion. 1360. Line The text on this line states that HW Models 5, 11 and 21 were selected for the 0.5 Hz tornado plots, but Fixed 116 the figure legends for the 0.5 Hz cases indicate that Models 5, 13 and 23 were used. Please check and correct as necessarv. 1361. Line Although the sigma model started as separate Tau and Phi_ss models. in the end a single total single-Done 151 site sigma model was used. Please acknowledge that here and describe that the individual Tau and Phi_ss models were used for purposes of the sensitivity analyses. Also describe how the user of the model can conduct a similar sensitivity analysis usinQ their own hazard code 1362. Line This statement implies that "Model 1" is always the central model of the representative suite of models Done 152 lfthere is some numbering convention for these models. please describe that convention. 1363. Line It is awkward that the first sensitivity analysis appears on the fifth line of the tornado plot. Please The discussion follows the order of the 168 consider here and elsewhere in the chapter discussing the sensitivity cases starting with the top line of nodes in the logic tree. The tornado plots the tornado plot and descending down the plot to make the discussion less confusing. are organized with the main effect at the top. 1364. Line The terminology used here is confusing, at best, and doesn't seem to have a useful purpose. The First comment fixed. 247 dichotomy "seismogenic sources" versus "tectonic sources" does not seem meaningful. Why are the Seismic source input is what gets fed into the former not simply called areal sources, since the other type -tectonic sources -are also seismogenic hazard code, so the term has not been sources? Further, in the next line, "Seismic source input" is used; what is the difference between changed. seismic source and seismogenic source? Finally, in Line 251, "areal seismic source" is used. This rrhird comment fixed paragraph needs to be rewritten with consistent. conventional terminology. 1365. Line There is some confusion as lo the use of the term "Sonora Basin and Range. The SSC model uses Done, a footnote was inserted (Rev.2) 266 the term "Southern Basin and Range". Here. you seem to indicate that the "Sonora component of this term is derived from the Lettis (2013) SSHAC2 report. This needs to be made clearer, and ii would also help if it were made clear that this region is now referred to as the Southern Basin and Range, especially as the Mexican Highland Basin and Range is in Sonora. Mexico 1366. Line Baja is not the name of the Mexican State that occupies the northern half of the Baja California Done 270 peninsula. It is Baja California. If this term is in reference to that used in Lettis (2013). please make that more clear by also referencing its current usage as Baja California in the SSC report. 1367. Lines Some of the faults have "fault" in their listed name, whereas others do not. Is there a reason for this, Done 274-and if so, please explain. Alternatively, make them consistent. 302 1368. Line Please describe what is meant by the term "wider tail" in this context. Done 401 1369. Line Here it states that the discussion will only address the 0.5 Hz SA sensitivities. whereas in the following References to the 5 Hz figures are removed 449 text, the figures addressing the 5 Hz sensitivities are also cited (Lines 462-463, 466 and 477). Please clarify. 1370. Lines Please be as specific as possible about what figure(s) are being referenced in the discussion. Please Care applied to address this request 451-also be more specific when describing the sensitivity cases. For example, the first sentence mentions throughout the chapter. 452 "the first sensitivity analysis" and the second sentence mentions "these sensitivity cases," without indicating how these two descriptions are related. Since there are a lot of repetitive statements in the text describing the sensitivity analyses and/or sensitivity cases. this comment applies throughout the chapter; please make it clear what sensitivity analysis and/or case is being discussed at any given time and where that analvsis andfor case can be found on the tornado clot. 1371. Line Section 7.4.1 does not include a discussion of additional epistemic uncertainty at large magnitude. Correct section provided 465 Please provide the correct cross-reference. 1372. Line Please add "types" between "two" and common form models" in order to avoid confusion. Done 468 1373. Line Please clarify what "Model 1" refers to on this Ii ne. That is the same approach followed in 506 Section 14.2.1. Model 1 is the central model in the ellipse. A qualifier has been added 1374. Line Please consider replacing the term "average" with the term "central" so as not to imply that it is Sentence edited 510 intended to represent the mean (average) hazard. 1375. Line Figure t4.3-tOa is cited on this line, but the discussion appears to refer to the case shown in Figure Done 511 14.3-9. Please check and correct as appropriate. 1376. Line Figure 14.3-9b is cited on this line, but the discussion appears to refer to the case shown in Figure 14-Done 517 10a. Please check and correct as appropriate. 1377. Lines Please add "types" between "two" and "common form models" in order to avoid confusion. Done 594-595 1378. Lines Figures 14.3 (a and b) are cited, but in Line 605, it is stated these would not be discussed further. Fixed in both instances 609 Please clarify. and 617 CHAPTER 15-Application Guidelines and Limitations 1379. Line 5 Please provide a cross reference to the adopted kappa value of 0.041s. Reference added to Section 5.3.3 and Appendix M 1380. Lines Please provide a cross reference to the section where evaluations are presented to support the claim Discussion added 5-8 that epistemic uncertainty in kappa is captured by the variation in high-frequency spectral shape within the SWUS GMC common-form models. 1381. Lines Please give the purpose for providing a representative Vs and density profile and what they can or Discussion added 12-14 should be used for, or delete this discussion from the report. Without such a statement of purpose, it is ambiguous why these profiles are presented. For example, if they are provided for purposes of documentina what was used to estimate the host kappa values for the NGA-West2 GMPEs, then their discussion should be part of the appendix that discusses the host kappa value determination. If they are meant to be representative of the site response predicted by the site terms in the NGA-West2 GMPEs, that has not been shown to be the case for these GMPES and is certainly not the case for the Eurooean or Jaoan GMPEs, which are likelv reoresented bv totallv different Vs and densitv orofiles CHAPTER 16-References 1382. Please carefully review these references for completeness and accuracy and for consistency with the Done (partially in Rev.1. completely in references provided in each chapter Rev2) Comment Response Table Comment Location in Text PPRP Comment Summary of Revisions to Report Number CHAPTER 1-xxxx CHAPTER 2-xxxx CHAPTER 3-xxxx CHAPTER 4-Seismotectonic Setting Lines 163-164 These lines refer to two categories, namely "the California and Mexico faults (referred to as Regions 1 and 2&3 in this Report)," and "other faults (AZ.NM, NV, and Mexico)" Table 4.2-2 has rows for "CA Faults" and "AZ., NV, & Mex Faults." Do the rows of the table correspond to the two categories of faults described in the text? If so, please align the teminology; if not, please clarify Lines 172-179 The legends of Figures 4-8a and 4-8b are not well correlated with the text. For example. "NSHMP faults" are noted in the legends but are defined neither there nor in the text. And the text calls attention to the dominance of distant fault sources for low frequency at 1 o** AFE, but the Figures do not identify the curves associated with "distant fault sources." Please reconcile the figure legends and text. CHAPTER 5-Ground Motion Databases and Candidate Models General Two references for Kishida et al.. 2014a and 2014b. appear in the reference list. However, many of the citations in this chapter refer only to Kishida et al (2014) without distinguishing 2014a from 2014b. Please check and correct this omission. General The figure numbering scheme seems to be inconsistent in this chapter. For example, Figure 5.2.2-2 is called in Section 5.2.2.1, indicating the convention that only the chapter number and first two section levels prefix the sequence number. But a Figure 5.2. 3.4-1 is called in Section 52 3.4. so in that case all three section levels prefix the sequence number. There are some other anomalies as well. Please check carefully and ensure that numberinQ is done consistently throuQhout. Line 47 Please add that the bottom frames also show the number of recordings per site class. Line 85 There is no sign in Figure 5.1.2-1 of "Station Z14A, shown by the open star". Please clarify. Line 87 Please complete the citation of "Kishida" (i.e .. Kishida et al. 2014a or 2014b?). Line 158 Please correct the figure number on this line, which should be Figure 5 1 5-1. Lines 173-174 The spelling of the fault names differs between the text and Figure 51.5-2 ("ltozawa" in the figure becomes to "ldozawa" in the text, and "Yunodake" in the figure becomes "Yunotake" in the text). Please edit for consistency. Lines 175-176 The total moment given here and attributed to personal communication is inconsistent with the moment magnitude of 6.7 given for this event on Line 164 (the sum of the moments on Line 175 imply M 6.56). Please resolve the inconsistency. In doing so. please consider whether it would be appropriate to cite published moment estimates (e.g., Tanaka et al. 2014, report a moment consistent with M 6.7 and approximately equally partitioned between the two faults) instead those reported from personal communication. Line 202 Please supply the missing Table 5.1.7-1. Line 216 Ku is undefined at this point in the text. Please correct this. Line 223 Please consider whether a more appropriate characterization than "upper bound" can be used here (e.g .. is that categorical statement even consistent with the one standard deviation ranges cited for the other methods?). Line 228 Please include a reference to a publication describing the SCEC BBP (e.g., the paper by Maechling et al. in the Jan/Feb 2015 SRL may be aporooriate ). Line 242 Please consider citing the published paper by Dreger et al. (2015) in the Jan/Feb 2015 SRL Lines 264-266 It is appropriate for the Tl Team to rely on the SCEC Validation Review Panel for the technical analysis of the simulations. and to rely upon the judgment of that panel to determine which methods met the acceptance criteria established in that review. However, the Tl itself needs to justify that meeting those acceptance criteria makes the methods suitable for the specific purposes for which the simulations are to be employed. Those purposes are stated on Lines 227-233. Please augment the summary statement on Lines 264-266 explaining how meeting the SCEC review panel's acceptance criteria makes the simulation methods suitable for addressing the problems laid out on Lines 8-14. Lines 306-315 This passage needs rewriting because: 1) the BSL model is not identified as GIL7 on Line 309, but seems to be the same as what is called GIL7 in the legend of Figure 5.2.2-1 and then on Line 312; and 2) the passage is repetitive (e.g., the verbiage about routine estimation of moment tensors on Line 309 is repeated on Line 314-315; the basis of the GIL? model in broadband waveform modeling is stated repetitively on Line 308 and then on Line 314). Line 322 "Frequency wave-number" is written differently on this line than it was on Line2 304 and 311 ("frequency-wave number"). Please review the hyphenation convention and apply one consistently (note also that both "wave number" and "wavenumber" are in common use, so the easier-to-read form "frequency-wavenumber" is also an option). Line 361

• 364 "Area" is used to signify rupture area in Equation 5.2.3-1, but 'A" is defined as rupture area on Line 364. Please edit for consistency. Line 383 Please correct the figure number. It is called out as Figure 5.3.2.1-1 on this line, but the figure itself is labeled as Figure 5.2.3.1-1. Moreover. the numbering scheme used elsewhere in the report seems to call forit to be called Figure 5.2 3-1. since it occurs in a subsection of Section 5.2.3 (e.g., by analogy with the fact that Figures 5.2.2-t and 5.2.2-2 occur in Section 5.2.2.1 ). Line 392 The figure number 5.2.3.2-1 is inconsistent with fact that it is the second figure in the subsection. Please check the figure numbering convention and make it consistent with the rest of the chapter and report. Line 452 The table called Table 5.1.1-2 on this line appears to be the table labeled Table 5.1-2 (and called by those numbers elsewhere in the reoortl. Please correct here and in subseauent occurrences. Line 464, 475, 481 Line 464 gives the distance criterion for NGA-W2_DC-MED as abs(Rx)<70km. whereas the lines 475 and 481 give R<70 km, which is more restrictive. Please clarify how the various distance metrics are used toqether to screen records for NGA-W2 DC-MED. Line 506 Previously. Akkar et al. (2014c) was cited as the database reference. Please check whether the citation given on this line is correct in the present context. Lines 508 and 517 The criterion abs(Rx)<70 km leaves the total distance unconstrained. Please provide a complete statement of the distance selection criterion.

Line 548 Please consider whether this might be a good place to introduce the symbol .Pss. so that it will be defined prior to its use on Line 553. Line 558 "Disaggregation" is used on this line, whereas "deaggregation" is used elsewhere in the report. Please edit for consistency. Lines 565-572 The selection criteria (distance. magnitude, number of recordings per event and site) do not seem to be given. Please check and correct if necessary. Line 566 "NGA-W2" is "NGA-West2" elsewhere. Please edit for consistency. Line 579 Please check whether "for use in should be "is used in". As is. the sentence lacks a verb. Line 585 Please add the missing parenthesis closure. Line 601 Section 5.4.1 does not contain the discussion of the Idriss 2014 model that is referenced here ("As noted in Section 5.4.1"), nor does there appear to be any prior reference to the Idriss model in the chapter. Please make the necessarv corrections. Lines 619 and 626 Line 619 has the statement that "the global dataset in this magnitude and distance range consists of 264-415 recordings from 4 to 23 earthquakes." Line 625 states "Within this magnitude and distance range, the global dataset contains four earthquake and 280 records." Please clarify why these statements are not contradictory. Line 627 The cited figures do not exist. Please add them. Line 669-670 Please correct the figure references (they should be to Figures 5.5.1-1 and 5.5.1-2). Line 673 Please correct the figure reference (it should be to Figure 5.5.1-3). Line 683 Please correct the table reference (the intended reference appears to be to Table 5.5.1-1). Line 724 Please clarify why specific scenarios had to be specified. given that kappa is not being explicitly modeled as a source effect. Line 727 Please consider rewording the reference to "Q attenuation." to avoid the implication that the kappa effect is necessarily physically distinct from effects ordinarily parameterized in terms of Q. Isn't the point that the kappa parameter (or at least Ku) is intended to capture attenuation effects that are so localized that in a practical sense they are better parameterized as site terms than as path-dependent attenuation terms. and that therefore isolation of kappa effects requires short-distance scenarios? Line 730 Please be more specific about which profile was used. Is it one of those in Figure 2.6 of Kamai et al (one is listed as having Vs30 of 750 mis. none has exactly 760 m/s )? Line 735 Figure 5.5.3-1 appears to be labeled incorrectly. Please correct this. Line 778 Rodriguez-Marek (2013) actually developed four single-station sigma models: one with neither M nor R dependence, one each with M and R dependencies, respectively, and a fourth with both M and R dependence. Please clarify which three have been chosen. and why. Note also that there is a perception of ambiguity introduced by mixing "dependent" and "independent" in listing the attributes of the selected models; i.e .. Is the "maqnitude-independent" model alluded to also R independent (in which case it would be clearer to say "magnitude and distance independent), or is there a typo such that "magnitude-dependent" is what is actually intended? If one of the figures were not missing, this ambiguity would be cleared up, but it would be better to also do so in the text. Lines 779 and 781 Please check whether the first of the three models alluded to should be "magnitude-dependent" (rather than "magnitude-independent", which would appear to be inconsistent with the figures). Alternatively, if "magnitude-independent" is correct as written, please clarify whether it is paired with a distance dependence or Lines 780-782 Only the R-dependent and MR-dependent models are shown. and these are in Figures 5.6.2-3 and 5.6.2-4, respectively (not 5.6.2-4 and 5.6.2-5 as called in the text). The other model (called "magnitude-independent" in the text) is not shown, nor is there any Figure 5.6-5. Please correct this. Line 789 Please cite a reference for the assertions about the small-magnitude limitations of GMPEs at short distance. Figure 5.1.3-1 The caption cites Akkar et al. (2014a and 2014b), whereas the text (Line 121) cites Akkar et al. (2014c), apparently in the same context. Please check whether this difference is intentional and make a correction if aooropriate. Figures 5.2.3.4-1 and These figures are mislabeled (as 5.2.3.3-1 and 5.2.3.3-2, respectively). 5.2.3.4-2 Please correct. Figures 5.3.2-1 and Please correct these figures: in each of these figures. the second row 5.3.2-2 repeats the first with a scale change, and the remaining plots (recordings per site, recordings per event, etc) are absent. Figure 5.5.3-1 Please correct the figure number. It is called as Figure 5.5.3-1, but labeled 5.5.3-2. Figure 5.6.4-1 Please add the dataset identifiers given in Line 805-808 of the text (Blea, Blea2, and ABR) to the figure caption, or else delete them from the text, as the inconsistency is confusing. CHAPTER 6-GMC Models for the Median Line 40-41 Please reconcile the statement that the finite-fault simulations "all show saturation at short distances" with the statement on Line 697 of Appendix J (and evidence in Figure J.4.3-1) that "the GMPEs have stronger saturation than the EXSIM model at very close distances." If it is correct that EXSIM has less saturation at short distances, please explain why this should not be interpreted as support for the Id 14 model (e.g., is the formulation of EXSIM such that it is not intended by its developers for use at the shortest distances? Or does the Tl Team argue on physical grounds that EXSIM is not reliable at short distances?). Line 105 Please hyphenate "large-distance attenuation" to resolve the otherwise ambiguous meaning. Line 303 Figure 6.3.2-5 shows CB 14 having a step-like change in its HW factor as Rjb approaches zero along the strike direction. As already requested in comment 978, please clarify how this is consistent with the claim that CB14 allows "a smoother transition" around the rupture compared with some other models. Lines 506-513 Please justify (as requested previously, Comment 389) how it is mathematically possible with the addition of the interpolated GMPE qround motions to better capture the correlations. Line 524 Please be precise about what "standard deviations" are plotted in Figure 6.4.3-1. Lines 536-543 This explanation needs to be set out more clearly. The sentence beginning on Line 536 says "for the DCPP application ... the central HW branch is applied to all common-form models." The rest of the passage, although rather difficult to read, appears to indicate the following: ( 1) HW effects are omitted from the 2000 models used for the Sammon's map, (2) the central HW model is appended to those footwall models, solely for the purpose of the simplified hazard calculations used in the selection of representative common-form (footwall) models from the original 2000, and (3) randomly selected HW models (from the equal-probability set developed in Section 6.3.2) are appended to the selected representative set of footwall models, to give the final set of common-form models for application to DCPP If this is a correct interpretation, then the last item seems to contradict the sentence from Line 536 (and if this is not a correct interpretation, some clarification is needed). Please rewrite for clarity and consistency. Lines 616-618 How can one Ztor value be used if the models do not include Ztor at all? Line 629 Please correct the spelling of second occurrence of "PVNGS." Line 632 Please check whether the intent of this sentence would be more clearly expressed if the final clause were included inside the parentheses. Line 633 It appears from Eq. 6.4-4 that it is the contributions to the Euclidean distance squared that are weighted by the weights from Eq. 6.4-7 (not the contributions to the Euclidean distance itself. as stated). Please correct or clarifv. Line 704 Please correct the typo, i.e., "two week" should be "loo weak." Line 879 Two consecutive figures are called "6 4 5-8." Please check and renumber as needed. Figure 6.7.2-2 Please label the vertical axis. Figure 6.7.2-3 Please identify the GMPEs associated with the respective colors, and make improvements to the legibility of the figure (note also that the figure did not appear in its entirety in the supplied pdf version). Figure 6.7.2-5 Please label the vertical axis. Figure 6.7.2-6 Please identify the GMPEs associated with the respective colors. CHAPTER 7-GMC Models for the Sigma: Overview and Methodology Line 84 Please add the missing words in this sentence (which currently reads "and chose through the"). Line 197 Please rewrite the final sentence of the paragraph to clarify its meaning (i e . a "value" cannot be similar to a "model," so it is not clear what point the sentence is trvino to convevl. Line 273 Please correct the inconsistency between the phrase "shown . . . for four spectral periods" and the list "(PGA, 0.1,0.5, 1.0.3.0 sec)," which (like the figure itself) includes five periods (PGA in addition to the four given spectral periods). CHAPTER 8-xxxx Section 8.2.2, There does not appear to be a reference to Figure 8.2-3 Please check general comment and add a reference lo this figure if one is missing. Line 167 Please improve clarity by adding a sentence break after the word "model." Figure 8.2-2 Please correct the weight for "Sim_DC-MED," (i.e., shouldn't it be 0.25?). CHAPTER 9-xxxx Line 38 Please follow the standard practice of numbering figures in the order in which they are first called in the text, which is not the case with the figure called on this line. Line 54 Chapter 6 of this report and the report on SSC model use the te1111 "virtual fault", rather then "pseudo fault." Please make a change for consistencv with those other usaaes. Line 371 Please correct the figure reference on this line (it should be 91-19). CHAPTER 10-xxxx NO COMMENTS CHAPTER 11-xxxx NO COMMENTS CHAPTER 12-xxxx NO COMMENTS CHAPTER 13-xxxx Line 61 Please correct the missing factor of two in Eq 13-5 (this typographical error is noted here just as a reminder: it has already been noted by the Tl Teaml. Line 77 Please correct the typographical error {"bi-linear). CHAPTER 15-xxxx NO COMMENTS CHAPTER 16-xxxx NO COMMENTS APPENDIX A-xxxx NO COMMENTS (REVIEWED AT BEGINNING OF PROJECT) APPENDIX B-xxxx NO COMMENTS APPENDIX C-xxxx APPENDIX D-xxxx APPENDIX E-xxxx APPENDIX F-xxxx APPENDIX G-xxxx APPENDIX H-xxxx APPENDIX 1-xxxx APPENDIX J-xxxx General Comment 788 on Rev.O requested editing of the appendix to conform lo the heading/subheading structure of the rest of the report (that is, the request was to number all subsections set off by headers, as in the rest of the report). This was not done consistently; the specific examples given to illustrate the intent of the comment were rectified, but the generality of the comment was not addressed To reiterate that comment: please edit the appendix for uniformity of style (specifically the treatment of subsection numbering) with the rest of the report. Line 50 Please distinguish this lengthy quotation by indenting the entire paragraph. Line 110 It is appropriate that the Tl Team relies on the SCEC Validation Review Panel for the technical analysis of the simulations, and that they rely upon the judgment of that panel to determine which methods met the acceptance criteria established in that review. However, the Tl itself needs to justify that meeting those acceptance criteria makes the methods suitable for the specific purposes for which the simulations are to be employed. Those purposes are stated on Lines 8-13. Please add a paragraph at the end of Section J.1.1 explaining how meeting the SCEC review panel's acceptance criteria makes the simulation methods suitable for addressing the problems laid out on Lines 8-13. Line 499 "PSA here symbolizes "pseudo-spectral acceleration" rather than "peak spectral acceleration." Please correct. and specify that the relevant values are the RotDSO spectra Line 520 The resultant of the summation is called Dip.,.,, in the equation, but is not a root-mean-squared quantity, but rather just a linear average. Please avoid confusion by using a more appropriate symbol for the sum, and also add the explanation that the summation is over the discrete fault elements. Line 526 There should not be a sentence break in this paragraph (the second part is not a complete sentence). Please correct (e.g., by merging the two parts into a single sentence). Line 537 The Figure and Table references on this line appear to be incorrect. Please check and correct them (it appears that they should be Figure J.2.2-1 and Table J.2.2-1 l. Line 538 The Figure and Table references on this line appear to be incorrect. Please check and correct them (it appears that they should be Figure J.22-2 and Table J.2.2-2). Line 543 Please check and correct the Table reference (it appears that it should be Table J.2.2-1) Line 553 Please check the accuracy of the gray curve in Figure J.4 2-1 that has a nearly flat zone from 0.5 to 1 Hz and, if it is correct as plotted, explain why this GMPE is used given this strange behavior. This request was also made as part of Comment 875 on Rev.O. Line 582 The dot colors in Figure J.4.2-3 are not explained (i.e., there is no explanation in the caption or legend of which color represents which GMPE). Please add the missing information, as was already explicitly requested in Comment 876 on Rev.O. Line 591 The comment that Method 2 "produces the lowest factors" appears to be true only at frequencies above about 1 Hz. If that is a correct interpretation of Figure J.4.2-3, please qualify the statement aoorooriatelv. Line 601 The statement that "the magnitude used in the GMPE is computed based only on the area of the closest segment" does not seem to be a correct representation of Method t. Doesn't Method t make two separate GMPE evaluations, using the respective magnitudes of the two segments for the respective GMPE evaluations? Please provide a more precise explanation for the relativelv low around motion factor from Method 1. Line 641 The dot colors in Figure J.4.2-6 are not explained (i.e., there is no explanation in the caption or legend of which color represents which GMPE). Please add the missing information. Lines 696-697 To repeat Comment 888 from the review of Rev.O: Please cite a published report or journal article for the observation that the GMPEs have stronger distance saturation than the ExSim model. Then the result mentioned here (regarding ExSim peak amplitudes) can be stated as a consequence of that fact (perhaps one pointed out by Dr. Atkinson to the Tl Team), rather than something to be taken purely on the authority of an unpublished comment bv Dr. Atkinson. Line 720 Please give the figure number corresponding to the description that begins on this line. Line 730 The dot colors in Figure J.4.3-3 are not explained (i e , there is no explanation in the caption or legend of which color represents which GMPEJ. Please add the missina information Line 909 The clause beginning after the parenthesis is a bit redundant (see Lines 893-894). Please consider deleting it to streamline the text. APPENDIX K-xxxx General comment on Please add a discussion of Figure K.1-6, which is not mentioned in the Section K.1 current text. Lines 6-8 If these are the same datasets defined in Chapter 5 and Table 5.1-4 (as the caption of Figure K .1-1 seems to indicate), please reference that table and aive the corresoondina dataset names here. General comment on Please cite the figures by number and state what is plotted in each Section K.2 Line 54 (Figure K.2-The vertical axis labels do not appear properly (at least in the PDF 1) distribution). Please correct. APPENDIX L-xxxx NO COMMENTS APPENDIX M-xxxx APPENDIX N-xxxx Line 32 Please explain why Figure N-1 seems to show a break in slope at M 7 in the dashed black curve for T=5, given that Equation N-2 only allows slooe breaks at M 5.5 and M 6 5 APPENDIX 0-xxxx APPENDIX P-xxxx Line 7 Please provide a page reference for the cited information in Ang and Tang (2007). Lines 8 and 9 The same symbol is used here for the variate ("-r2 follows a scaled chi-squared distribution") and a parameter of its distribution function ("with mean given by T2) Please remedy this source of confusion (this notational issue was also noted in Comment 174 on Rev OJ. Line 17 The notation does not properly distinguish the variate from its expected value. Please correct this (as was done for, e.g., Eq 13-4 and 13-5). Line 19 "0.6" should probably be "0.63." Please check and correct if necessary. Lines 25 and 26 The same symbol is used here for the variate (<!>1,,/ follows a scaled chi-squared distribution") and a parameter of its distribution function ("with mean given by .P:..i,-R2"). Please remedy this source of confusion (this notational issue was also noted in Comment 174 on Rev.O). Lines 36 and 37 The same symbol is used here for the variate (T2 follows a scaled chi-squared distribution") and a parameter of its distribution function ("with mean given by Please remedy this source of confusion (this notational issue was also noted in Comment 17 4 on Rev 0). Comment Response Table Comment Location in PPRP Comment Summary of Revisions to Report Number Text CHAPTER 1 Introduction Line 4 October? This project extends into February, 2015 Line 10 Should read .. Western U.S. sites. three Western ... " Line 115 " ... central Arizona compared and the path ... " Change and to with CHAPTER 2 Project Organization Line 81 Saint Onofre should be San Onofre Line 200 Change thought to through Line 207 Correct were generally are" -delete one of the verbs Line 241 Correct spelling of draft (drat) Line 260 Correct "tee" to "tree" CHAPTER 3 Work Plan Line 3 Correct spelling of fulfill CHAPTER 4 Seismotectonic Setting Line 77 Delete "of range after "and the range" Table 4.1-4 Include DCPP in the table title Table 4.2-1 Include PVNPP in the table title Table 4.2-2 Include PVNPP in the table title Figure 4-1 The two line colors for the SAF are not clearly distinguished in the figure Figure 4-2 Include "of DCPP" in the figure caption Figures 4-5 and 4-6 Consider combining these figures Figure 4-6 The arrow for Cerro Prieto fault points to the Imperial fault. The CPF is the next bold red line to the SW. Please correct. Chapter 5 Ground motion Databases Line 27 Wasn't the Wells earthquake in the "Northern Basin and Range. Or do you mean that the Wells earthquake provides control for a normal faulting earthquake. if one should occur in the Southern Basin and Range? Please clarify and correct, as needed. Line 85 The "open star is not evident on figure 5. 1 .2-1. And this figure is the "data distribution", not "attributes". Is this the correct figure attribution? Line 276 "were compared to the a suite" Please correct this error. Section 5.2.3.1 Need to cite figure 5.2.3.1-1 in this section -currently not referred to Line 383 Figure should be referenced as Figure 5.2.3.2-1. Please correct. Line413 These figure citations appear correct but the cited figures appear to be mislabeled as Figs. 5.2.3.3-1 and -2. Please check and correct. Lines 427, 431, and These figure citations appear correct but the cited figures appear to 433 be mislabeled as Figs. 5.2.3.4-1, -2 and -3. Please check and correct. Line 452 Table 5.1.1-2 is not provided, or this citation is incorrect. Please check and correct. Line 458 Table 5.1.1-2 is not provided, or this citation is incorrect. Please check and correct. Line 490 Okay. Figure 5.2 3 1-t is finally cited -this needs to be cited earlier, or the figure number needs to be corrected for inclusion in this sec1ion. Line 610 Is "200-30 km" correct, or should it be 200-300 km? Line 627 The figure citations here are incorrect -these apparently refer to Figures 5.4.4-1 through 5.4.4-3 Lines 669 and 670 The figures cited do not appear to be the correct citations -please check and correct. (appear lo be referring to Figures 5.5.1-1 and -2) Line 673 The figure cited does not appear to be the correct citations -please check and correct. (appears lo be referring to Figure 5.5.1-3) Line 683 Table 5.5.2-1 was not provided. Please check this table citation and correct. Line 712 Table 5.5.2-1 was not provided. Please check this table citation and correct. Line 735 Figure citation is incorrect -should this be Figure 5 5.3-2? Or is the figure mislabeled. Lines 780 and 781 Please check that the figure citations correspond to the correct figures, as there appear to be discrepancies between the text, figure captions and figures. Figure 5.2.2-2 The caption should indicate that this is for an M4.7 aftershock to the SS earthquake, as discussed in the text. Figure 5.2.3.1-1 Not cited in the correct location in the text Figure 5.2.3.3-1 and -Check figure numbers 2 Figure 5.2.3.4-1 and -Check figure numbers 2 Figure 5.5.1-1 and-2 The red and dashed lines should be explained in the caption Line 1337 Check if this figure number is correct Line 1344 This caption should be improved to better fit the text Chapter 6 GMC Models For the Median Line116 Remove the extra "D" in ld14 Line 234 Magnitude depth?? Do you mean rupture depth? Line 298 "RO" is RxO in the figures -please correct. Line 487 The phrase in the areal sources in the as shown in ... " is not clear. Please correct. Line 494 "are shown in figures" is repeated twice -please correct. Line 495 Please correct "thought" to "though" Line 704 Correct week lo weak Line 879 Figure 6.4.5-8 should be 6.4.5-9. Also change 9 to 10. Correct both citations in this paragraph. Line 1093 Correct dip-sip to dip-slip (2 cases) Table 6.7-1 Is a 22 km down-dip width consistent with the 15 km max. depth for Hosgri rupture widths? Figures 64 1-4a, 4b, Is the 3*c panel down on the right from Idriss (2014)? If so, correct Sa. and Sb 114 to ld14 for consistency Figure 6.4.4-1 Caption should define what the colored points are. Figure 6.4.5-2b Caption states that the GMPEs are in black. However, the key shows this as a different color. Please correct. Also, make the color schemes the same between 2a and 2b. Line 1637 This should be Figure 64.5-9 Line 1646 This should be Figure 6.4.5-10 Figure 6.6.1-1 This figure should include the DCPP site Chapter 7 GMC Models for the Sigma Line 59 "of the events from events" is unclear -please correct. Line 121 Delete "of' between "distributions" and "kappa" (repeated) Line 183 Figures 7.2.3-3 and 7.2.3-3 should be corrected to 7.2.3-2 and 7.2.3-3 Line 216 "they generally fall within the uncertainty range." Generally? It looks like they mostly do Lines 266-269 This sentence is difficult to understand -please clarify. Chapter 8 Median GMC Models: DCPP Line 125 2000 common form ???? Models? Not clear. Line 257 Weight is stated as 0.25. On figure 8.2-2, both are 0.75. Please check -the figure appears to have an error. Line 285 Figure 8.4-7 not provided. (???) Line 388 Is there a 7 missing? 8.4-7 Please correct. Figure 8.2-2 Under the Data Set node, both have a 0.75 weight -one should be 0.25 Figure 8.2-3 Figure does not appear to be cited in the text. Please check. Chapter 9 Median GMC Models: PVNPP Line 232 Figure 9.1-10? Do you mean 9.1-9?? Lines 342-347 This section seems to just hang, as if not complete. Please add a closure statement on its significance. such as -Consequently, .... Figure 9.1-13 These 2 figures would be easier to compare if they had the same vertical scale. Figure 9.2-1 Idriss 2014 is referred to as 114 -please make consistent with the text. Chapter 10 Tau Model Logic Trees No comments Chapter 11 Phi Model Logic Tree: DCPP No comments Chapter 12 Phi Model Logic Tree: PVNPP Line 146 *'weight of 02 because .. " 02? Please correct this value Chapter 13 Total Sigma Model Line 77 "leads potential"?? Please clarify. Line 90 "the following table"??? What table -this "following table" needs to be assigned a Table ##consistent and in order with the rest of the tables-ie., Table 13-1. Please correct and also correct the numberina in the subseauent tables. Line 154 "using the method" is not clear. Please specify the method. Line 184 Define lnormal or correct this Log normal? Also. correct og to of Chapter 14 Hazard Sensitivity Line 88 Caption of figure 14.2-3 hazard for hazard" is confusing. Do you mean "hazard vs. the hazard at.."? This also applies to the next figure (14.2-4). Line116 States that models 5. 11. and 21 are used for the 0.5 hz case, but figures indicate that models 5. 13, and 23 were used. Please clarify or correct. Line 121 even thought the logic tree .. " Do you mean "even though the logic tree ... "? Line 172 Ration? Do you mean ratio? Line 247 1) "consists of seismogenic sources" Are these not the areal sources, as indicated in the parentheses? Why are these not simply called out as areal sources, as the other type -tectonic sources -are also seismogenic sources. This makes it confusing. 2) Further, in the next line. "Seismic source input" is used -what is the difference between seismic source and seismogenic source? 3) Finally, in line 251, "areal seismic source" is used. This paragraph needs to be clarified in terms of usage of the terms "areal sources", seismogenic sources", seismic sources", versus tectonic sources (which I assume you are referring to specified fault sources) Line 266 There is some confusion as to the use of the term "Sonora Basin and Range. The SSC model uses the term "Southern Basin and Range". Here, you state (I think) that the "Sonora" aspect of this term is derived from the Lettis (2013) SSHAC2 report. This needs to be made clearer, and it would also help if it was made clear that this region is now referred to as the Southern Basin and Range, especially as the Mexican Highland Basin and Range is in Sonora, Mexico. Line 270 Similar comment as above. Baja is not the name of the Mexican State that occupies the northern half of the Baja California peninsula. It is Baja California. If this term is in reference to that used in Lettis (2013), please make that more clear by also referencing its current usage as Baja California in the SSC report. Lines 274-302 Some of the faults have "fault" in their listed name. whereas others do not. Is there a reason for this. aand if so, please explain. Alternatively, make them consistent. Line 449 Here it states that the discussion will only address the 0.5 hz SA sensitivities, whereas in the following text, the figures addressing the 5 hz sensitivities are also cited (lines 462-463, 466, 477). Please clarify. Line 472 1' "sensitivity" of the line -should this be followed by analysis? Preceded by "determination of'? Line 506 What does Model 1 refer to? Not Model A or Model B. Please clarify (label in figure??) Line 511 Figures 14.3-9a and 14.3-1 Oa are cited, but it is figures 14.3-9a and b that you are referring to Please correct the text. unless the figures are mislabeled. Line 517 Same comment as above, but for figure 14.3-9b and 1 Ob -should be 14.3-10a and bat 0.5 hz Line 609 and 617 Figures 14.3 (a and b) are cited, but in line 605, it is stated these would not be discussed further. Why are they cited here? Chapter 15 Application Guidelines and Limitations No substantial comments Comment Response Table Comment Location in PPRP Comment Summary of Revisions to Report Number Text CHAPTER 1 Introduction Lines 51-55 Suggest this sentence be broken into 2 sentences for clarity Line 62 Comma after "site-specific rock condition" Line 91 Suggest putting Q in parentheses Line 149 Fix margins CHAPTER 2 Project Organization Line 13 Suggest comma after "(U.S. NRC, 1997)" Line 35 Set should be plural Line 99 Product should be plural Line 146 Estimated should be estimates Line 155 Suggest comma after Arizona Line 238 Suggest comma after comments Line 240 Suggest insertion of "the" after reviewing Line 252 "shows the dates of the main .. " change "of' to "that" CHAPTER 3 Work Plan Line 9 Suggest insertion of "the" belween "as" and "kick-off' Line 120 Station should be plural Line 125 Suggest comma after "conducted" Line 159 Questions should be plural Line 187 Include should be included Line 224 Suggest insertion of "the" between "In terms of' and "sigma models" Line 238 Insert "to after "prior Line 291 Insert "to" after "pertaining" CHAPTER 4 Seismotectonic Setting Line 60 Ranges should be singular Line 112 and 116 Capi1alize Southern consistently, or use lower case consistently for Southern Basin and Range. Suggest caps. as we have formalized the term SBR Chapter 5 Ground motion Databases Line 37 Suggesl comma after residuals Line 140 Suggest insertion of "the" between "For" and "objective" Lines 140, 141 Suggest period after "al" in Lin et al. (here and elsewhere) Line 186 Suggest changing containing to contains. Line 313 Suggest comma after (Pasyanos et al., 1996) Line 385 Ruptures should be plural. Line 422 "using for?? should this be used for? Line 451 "The subsets of the subset of... is confusing. Is this correct? Please consider rewording. Line 484, 485 Was selected is repeated as selected was This is a confusing sentence -consider rephrasing. Line 498 "study" should be studies Line 501 "and by the distant" should be "and from the distant" Line 579-580 There is no verb in this sentence Line 586 Figures should be singular Line 623 The citation to Table 5.4.4-1 has an extra period "4.-1" Line 654 Function from? Do you mean functional form? Line 695 Insert "and" between "another" and "should" Line 699 A comma is needed after "selected" Line 703 Change rejection to rejecting. or place "of' after rejection Line 703 "ad" should be "and" Line 752 Suggest a comma after is used" Line 754 Suggest set be pluralized Line 777 Suggest a comma after data" Line 787 Change "as" to "at" Chapter 6 GMC Models For the Median Line 16 Delete up" Line 42 Delete the extra ) after T akedatsu, 2015 Line 57 Insert "to" between "leads" and a model" Line 58 Add "because" after **and furthermore." Line 67 Magnitude should be plural Line 71 Add a comma after "50 km) Line 143 Replace "in" with "on" -Based on ... Line 155 Insert "a between "explained as" and "geometric" Line 238 This would read better as " ... Model to account for the HW ... Line 274 Was calculated or were calculated? Line 362 Place a comma after GMPE. Also. magnitudes should be plural. Line 439 Place a comma after (Model B) Line 466 Insert "and" after M>7.5, Line 496 Place a comma after "used" Line 542 HW models" -models should be singular. Line 548 Change applies to applied Line 569 Set off wi with commas Line 594 In is given" should read "It is given" Line 615 "the difference is scaling" -is should be "in" Line 801 Reflects should be singular Lines 802/803 Move "fully" to before "represents Line 830 Example should be plural Line 882 Figures should be lower case Line 892 "These two model" -model should be plural Line 902 Insert "to the between similar and Spudich Line 936 Insert a comma after (20t4) Line 954 Insert "a between "for" and "strike-slip" Line 1019 Insert "a between ruptures of' and splay fault" Line 1029 Insert an "a" between Approximate a" and "Single Fault". Same with next two lines. Chapter 7 GMC Models for the Sigma Line 12 The closing parentheses should not be subcase Line 100 Insert a comma after "used" Line 101 Insert a comma after "data" Line 107 Insert a comma after "used" Line 108 Insert a comma after "residuals" Line 194 Delete the extra "for" near the end of this line. Line 290 Insert "of' between "distances" and "200-300". Also, Section should be lower case. Line 291 Indicated should be indicates Line 301 Insert "a" between "of' and "few" Line 318 "explanation or this trend change "or" to "for" Line 382 with respect of distance" should be "with respect to distance" Line 499 Provide should be plural Line 518 Insert a comma between branches" and "is developed" Chapter 8 Median GMC Models: DCPP Line 36 Suggest a comma after figures" Line 42 Consider changing random to randomly Line 55 Fault should be plural Line 60 "to the five" should be "for the five" Line 86 "DCPP has made .. . should be "DCPP was made" Line 167 model this penalizes" should read "model that penalizes" Line 293 Insert "and" before "as noted" Line 377 Insert a comma after "removed" Lines 395-396 Place a comma after magnitudes and delete the and" before distances Chapter9 Median GMC Models: PVNPP Line 11 Tl Team should read Tl Team's. Also. weighed should be weighted. Line 25 Capture should be plural Line 40 Insert a comma after "considered". Also. (NGAW2-pv.MEov needs an end-parenthesis Line 41 Remove end-parenthesis after Section 5.3.2 Line 82 Insert a comma after "respectively" Line 86 Under laying?? Underlying? Line 119 There is an extra period after "is used" Line 185 Magnitude should be plural Line 182 Insert comma after "Figure 9. 1-2 Line 219 This sentence would read better if "and that" was replaced by "whereas'" Line 226 "right and side"?? You mean right hand side, correct? Line 254 "is referred to as "influence diagram" -insert "an after "as" Line 278 Insert "to" after "respect" Line 356 Remove the comma after "Section 5. 1.5.2" -it is not needed. Also, "(M6.5 for each ... " Each what? Lines 412-416 Break this into 2 sentences. Start the 2"" sentence at 'Therefore, ... ** Line 424 Sentence ends with a comma. Chapter 10 Tau Model Logic Trees Line 4 Sectrion should be Section. Line 7 Insert "a" between "develop" and "single" Line 34 Insert "that" after "2014 )" Chapter 11 Phi Model Logic Tree: DCPP Line 23 Place a comma after Taiwan. Line 53 Place a comma after "Appendix R Line 59 Place a comma after "respectively" Line 79 Delete "a" between "as" and "heavy-tailed" Line 127 Insert a space after phi Line 132 Delete "the" between "because and "most" Chapter 12 Phi Model Logic Tree: PVNPP Line 10 Insert comma after PVNGS Line 12 There should be the. Plus insert "are" after "the" Line 13 Need a) at the end of the sentence. Line 28 Delete the extra space before the period. Line 29 Insert "which are" after "events" Line 30 Toe should be to. Line 46 Number should be plural Line 50 Time should be plural Line 52 Insert "the" before Tl Team Line 72 Insert a comma after "respectively" Line 102 "dataset contains should read "datasets contain". Also, insert a comma after "records" Line 123 Magnitudes should be singular Line 132 Insert a comma after "respectively" Line 137 Insert a comma after "respectively" Chapter 13 Total Sigma Model Line 32 Approached should be approaches Line 39 Represent should be plural Line 42 Insert a space between "the" and "greater Line 52 Change the period to a comma after Appendix P Line 54 scaled" is repeated -delete one. Line 74 One to one -correct the zero to a lower case o Line 76 Point should be plural Line 82 "uses" should be "used". Also. "numerical" should be "numerically" Line 109 "Greater Arizona source" -source should be plural. Line 125 Insert "as to after "designated" Line 132 Delete "for" between "of the" and "single" Line 135 indicated" should be "indicate". Also, insert "with" between that" and "the Line 176 Insert "affects" after "path" Line 182 The title should read "Implementation of the Mixture Model Chapter 14 Hazard Sensitivity Line 15 Insert comma after "plant sites" Line 164 Insert comma after "several nodes" Line 351 "show should be plural Line 403 Change "that" to than Line 461 Insert a comma after "approach" Line 473 Delete "in" (presented in with the next case) Chapter 15 Application Guidelines and Limitations Line 34 "then" should be "the" Line 45 Insert "a" between "at" and distance" Line 56 Available" is misspelled. constraint" should be constrain". Line 57 "comprising is misspelled Section 6.5 Are Eq. 6.5-8 and Eq. 6.5-18 identical? If so, please remove Eq 6.5-18 and associated text. The same comment applies to 6.5-9 and 6.5-19, 6.5-10 and 6.5-20. Lines 1164 and 1165, variable clcHANGE was not defined. Line 2051, please explain which sigma is plotted in Figure 6.5.1-3. Is it fo1R_s1G_ss (Eq 6.5-10) or cro1R_ss? Line 1197 to Line 1199, please clarify if the inputs the Tl Team used to produce Figure 6.5.1-3 are meant to represent the dominant scenarios for DCPP and PVNGS? Which of the two Rys is representative of DCPP? November 3, 2012 Carola Di Alessandro, Ph.D. Project Manager for the SWUS GMC SSHAC GeoPentech, Inc. 525 N. Cabrillo Park Drive, Suite 280 Santa Ana, CA 9270 I

Dear Dr. Di Alessandro:

The Participatory Peer Review Panel (PPRP) has reviewed the Project Plan (dated October 3, 2012) for the Southwestern U.S. Ground Motion Characterization (SWUS-GMC) SSHAC Level 3 study. The Project Plan document is well prepared, explains the SSHAC Level 3 guidelines well, and provides a framework for successful implementation of those guidelines. The Plan calls for an additional member, not yet named, to be appointed to the Technical Integration (TI) team to provide expertise in numerical ground motion simulation. That appointee should be knowledgeable with respect to the techniques employed in such studies, as well as knowledgeable in the appropriate selection of model parameters for those studies. We look forward to seeing that position filled by an experienced scientist or engineer with a well-established professional or academic reputation, so that this appointment will also bring the TI team an appropriate balance between experienced experts and more junior members. The PPRP requests that some clarifying language be added to the plan, as noted in an attachment to this letter. The panel believes that, with these clarifications, together with the augmentation of the TI team described above, the Project Plan has the elements required for meeting the SSHAC Level 3 objectives. We thank the project team for its efforts in developing the plan and look forward to its implementation. Sincerely, Steven M. Day Chair, PPRP Brian Chiou Member, PPRP Kenneth Campbell Member, PPRP Thomas Rockwell Member, PPRP

Attachment:

Requested clarifications and edits Attachment to PPRP letter of November 3, 2012 Requested clarifications to SWUS GMC Project Plan 1. It still does not appear to us that the project plan spells out clearly that comparison tests will be m<1de of the different h<1zard codes used by the three utilities, as discussed in our initial review1, <1nd we request that this be addressed. 2. The Project Pl<1n stipulates that the PPRP will meet for a half day after Workshops 1 <1nd 2, and we reaffirm our requestz for a modification of the language to note that the PPRP will have the flexibility to complete its post-workshop deliberations by teleconference and/or email. We feel that occasionally, due to scheduling or personal difficulties, those other arrangements may be the optimal way to insure full participation of the panel. 3. The project pl<1n notes that documentation of the numerical simul<1tion methods will be part of the project database, but does not address our concern that the documentation be available to the PPRP in advance of the time when the models are evaluated3. For models like these being developed via university research, it is reasonable to be concerned that insufficient documentation may be available at the time of model evaluation. Hence, it is important that the Project Plan be clear about the documentation ground rules and the consequences of insufficient documentation. Minor editorial notes (i) Page 18, row 5 (Compile Regional GM data for Arizona): Although this work has been discussed during the working meetings and it is clearly important, it was not mentioned in the main text of the Project Plan, so we suggest removing it from Figure 2 or adding some discussion to the Project Plan. (ii) It would be helpful to have the TI Te<1m briefly describe how the simulated dat<1 will be used in the GMC study, in particular in the construction of the logic tree (e.g., will there be branches based on the simulation results?). (iii) Page 12, 2nd paragraph --typo 'Wworkshop' (iv) P<1ge 12, 7th bullet --'as distances' should be 'at distances' 1 PPRP review memo dated 9 /17 /2012, see Note 4 2 Ibid, Note 10 Note 2 From: Carola DiAlessandro Sent: Monday, July 28, 2014 10:23 AM To: Steven Day; ken.w.campbell@comcast.net; brian_chiou@comcast.net; Tom Rockwell Cc: norman abrahamson; Katie Wooddell; Douglas Dreger; Bob.Youngs@amec.com; Linda Al Atik; Nicolas Kuehn; Jennie Watson-Lamprey; Nick Gregor; Melanie Walling; Gabriel Toro; mcguire@lettisci.com; John Barneich

Subject:

Follow up after PPRP Briefing: please provide your feedback at your convenience

Dear Steve and PPRP Colleagues,

We would like to follow up with you after the concluded PPRP Briefing held on July 17 and 18 @ UC Berkeley. We have not received any further feedback from you so far, besides for the verbal comments received during the meeting and summarized in the notes shared with you soon after the event (https ://www .dropbox.com/s/ .... omlssis ... ./Jul 17-18 PPRP notes.pptx) As a reminder, the notes and the presentations were collected under the DropBox link https://www .dropbox.com/ .... omissis .... / , which is in turn accessible from the PPRP Transmittal Folder at https://www.dropbox.com/. ... omissis ... ./ Please let us know as soon as possible if those notes are comprehensive, and if you have any further feedback on the presentation material and/or on the Preliminary Draft Report. We are revising the GMPE selection approach via visualization and addressing other concerns as emerged during the discussions. We also look forward to revising the Draft Report to encompass the changes in the GMC model while capturing your requests, so please provide your feedback at your earliest convenience. Should you have any question or concern, do not hesitate to contact us. With best regards, Carola Di Alessa11dro, Ph.D. Project Manager.for the SWUS GMC SSHAC GcoPcntcch, Inc. 525 N. Cabrillo Park Drive. Suite 280 Santa Ana. CA 92701 Mobile: 510-491-6713 Fax: 714-796-9191 Office Phone: 714-796-9100 Email: carola dialessandro(a;geopentech.com February 23, 2015 Steven M. Day Chair, Participatory Peer Review Panel Department of Geological Sciences San Diego State University 5500 Campanile Drive San Diego, California 92182

Dear Prof. Day:

The Tl Team and PM appreciated the valuable comments and suggestions received from the Participatory Peer Review Panel (PPRP) during the report preparation. This communication serves to provide the PPRP with updates on the Tl Team and PM replies to the Comments included in the Participatory Peer Review Panel Letter No. 3: Draft Rev.1 Report, Southwest United States Ground Motion Characterization Level 3 SSHAC Project, dated Feb. 20, 2015. Each of the Tier 1 Comment is addressed in detail by means of a Tl Team-PM reply, and by providing an excerpt of the report where the edits were incorporated. We are aware of a documentation limitation associated to the directivity model which we expect being included in the planned PPRP Closure Letter. We are already preparing a response to address such limitation, to be incorporated in the Rev.1 Report publication (Feb. 26, 2015). In the case of the Tier 2 Comments, the provided format of the Comment Response Table was used to fill the column entitled "Summary of Revisions to Report". We want to clarify that the edits associated to the Tier 2 Comments are still ongoing, and we expect to address the majority for the Rev.1 Report publication. There are however some comments that will remain not addressed for paucity of time. For clarification, the open items not yet addressed are associated to all three installments received from the PPRP. The Tl Team and PM plan to address those left-over comments in the following week, and to issue a Rev.2 Report by March 10, 2015. We'll follow up with the PPRP on a mutually amenable logistic for completing such task. We hope you will find this document useful for resolving the Tier 1 Comments, and for evaluating the Tl Team's progress on addressing the Tier 2 Comments. Sincerely, --Carola Di Alessandro (also in behalf of the Tl Team) TIER 1 COMMENTS Comment Number 1033 -Directivity Model: General PPRP Comment: The Tl team has not provided sufficient information detailing their evaluation of the directivity model. It is necessary that the explanation of the Tl Team's evaluation include sufficient detail to clarify (1) what the model is, (2) what its limitations are, and (3) what analysis was done to demonstrate that it is justifiable (in light of any model limitations) to use it for the purpose it is being used for here. Please provide an explanation meeting those criteria in the report. Tl TEAM -PM Reply: 1) The text in section 6.5 was revised to fully describe the Watson-Lamprey directivity model. The equations and coefficients describing the model, currently included in the DCPP HID (Appendix C -Part II), were included in the main report. (2) The text in section 6.5 was expanded to describe the limitations that we see with the Watson-Lamprey directivity model: (i) it is only for straight faults, (ii) it applies the CY14 directivity to other GMPEs, (iii) it uses the changes to the standard deviation in the CY14 model to scale the standard deviations from the other GMPEs (3) Analyses done to demonstrate that the model is justifiable were added to the text of section 6.5. We included simple checks to show that the results from the model are reasonable in that they are consistent with the range of directivity effects from other directivity models. The PPRP has provided feedback that such simple checks are inadequate, but the Tl team's judgment is that, given the small effect on the hazard at DCPP (less than 2%), using simple checks is justified because even if the Watson-Lamprey model is off by a factor of 2, there would still be only a small effect on the hazard (less than 4%). This conclusion that the directivity effect on the DCPP hazard is small is based on using the Watson-Lamprey model to do the hazard runs. So if the Watson-Lamprey model is wrong, it is not a valid check. Our simple checks provide us confidence that the Walson-Lamprey model is reasonable for the cases that control the hazard at DCPP. An alternative would be to run a full comparison of the hazard run with the CY14 methodology for directivity; however, we do not expect to be able to complete this comparison by Feb. 23, 2015, as requested. A place-holder has been inserted in the text to accommodate the discussion on the comparison, if time allows. We recognize this will remain as a limitation of the Tl Team model, but due to the small effect of directivity on the hazard at DCPP, the Tl Team judged that this limitation is mainly of scientific interest and not a significant issue for the hazard for DCPP or PVNGS. Because (1) the Watson-Lamprey model is still under review a PEER and (2) the effect on the hazard at DCPP is small, (3) questions about the applicability of the CY14 centering and directivity models to other GMPEs, and (4) large increase in hazard run times with little expected effect if the CY 14 directivity model is implemented in the hazard integral, the Tl Team judged that it would be better to remove the directivity model from the DCPP model. Comment Number 1034-Directivity Model: Chapter 6, Lines 914-922 PPRP Comment: There are two major assumptions that are made in applying the CY14 centered directivity model to the GMPEs used in the DCPP GMC model: (1) that the large-magnitude distribution is similar amongst the NGA-West2 GMPEs so that similar directivity effects can be expected, and (2) that the centered CY14 model can be applied to the NGA-West2 GMPEs to model these effects. These are both potentially important assumptions. Please provide justification for these assumptions or indicate that the impact of these assumptions is not critical to the hazard. Tl TEAM -PM Reply: Based on the CY14 centered model and using the Watson-Lamprey simplified model, the directivity effect on the hazard is small (2% or less) as shown by sensitivity analyses documented in Chapter 14. Considering the similarities of the large-magnitude short-distance data used by the various modelers, the Tl Team's judgment is that the directivity effects will not become significant to hazard if separate centering models were developed for each GMPEs. PEER plans to develop GMPEs including directivity effects that are centered for each individual GMPE. This work is currently scheduled to be completed in 2017. It is beyond the scope of SWUS to develop these models. Comment Number 1035-Directivity Model: Chapter 9, Lines 317-320 PPRP Comment: Please further justify the zero weight given to the directivity adjustment branch by providing evaluations in support of the claim that directivity effects are adequately captured by the standard deviation from the GMPEs. Also, if this claim is justifiable, please explain why the same justification was not applied to DCPP to assign a zero weight to its directivity branch. Tl TEAM -PM Reply: The text of Section 6.5 (not Chapter 9) was revised to include the discussion outlined below. The standard deviation of GMPEs is due to the simplification of the source, path, and site effects. (We use the single-station sigma approach which removes the simplification for site effects, so all that remains is the source and path) A key assumption in using the single-station standard deviation from empirical GMPEs for hazard calculations is that the data used to develop the GMPEs are a representative range of other aspects of the source and path that are not captured in the simple parameters used in the GMPEs. This would include the location of the hypocenter (e.g. directivity), slip distribution, rupture velocity, rise time (or complete slip time function), and 3-D crustal path effects. Directivity is just one of the parameters that is assumed to be representatively sampled in the empirical data. In magnitude-distance ranges for which there are large numbers of recordings, forward, neutral and backward directivity conditions are all sampled. We assume that the sampled distribution is representative of the distribution of future earthquakes. In magnitude-distance ranges for which there are fewer data (e.g large magnitudes at short distance), it is less likely that the distribution of directivity effects in available empirical data set is representative of the distribution of directivity effects for a future earthquake at a specific site. For this reason, we used the Watson-Lamprey simplified model to check this for DCPP, which has nearby faults. The hazard results showed for that for DCPP site, the impact of using the distribution of directivity effects based on the CY14 parameterization (as simplified by Watson-Lamprey), was almost the same (less than 2% difference) as using the distribution in the data used by the GMPEs. For directivity, we will add a plot that shows the distribution of the IDP directivity parameter in the NGA-West2 data set for various magnitude and distance ranges. As stated in response to comment 1033, the Tl team decided to change the logic tree for DCPP to put full weight on the no directivity branch. This will avoid the inconsistency in the application of directivity between DCPP and PVNGS. Excerpt of Chapter 61 Section 6.5 and associated figures/tables follows in the following pages. Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 956 of ground-motion predictions for different two different magnitudes and distances, and calculating their 957 ratios. 958 Figure 6.4.5-15 and Figure 6.4.5-16 show an el(ample of the epistemic uncertainty in distance and 959 magnitude scaling, respectively, for PVNGS (Model A), normal style of faulting, for T" 0.01 sec. Figure 960 6.4.5-15 shows the PSA ratio histogram for distance scaling for a M6 scenario. Figure 6.4.5-16 shows the 961 PSA ratio histogram for magnitude scaling for a Rx distance of -15 km. These figures show that the range 962 of magnitude and distance scaling in the selected models is broader than the range of the candidate 963 GMPEs. 964 Appendix H includes several plots showing epistemic uncertainty in distance and magnitude scaling for 965 various periods for DCPP and PVNGS, respectively, in Sections 2.1.11, 2.1.12, 3.1.11, 3.1.12, 4.1.11 and 966 4.1.12. 967 968 6.5 Directivity Scaling Models 969 6.5.1 Candidate Models for Directivity Scaling 970 The most widely used models for incorporating directivity effects into ground motions are the 971 Somerville et al. (1997) model and Abrahamson (2000) modification to this model. These two models 972 parameterize the directivity effect for strike-slip faults using X cos(theta) as the predictive parameter, 973 where X=s/L is the ratio of the rupture length between the epicenter and the site (s), to the total rupture 974 length (L), and theta is the azimuth between the fault strike and the site azimuth from the epicenter. 975 In 2008, updated directivity models were developed as part of the PEER NGA-Westl ground motion 976 study. The el(panded empirical data sets and numerical simulations for directivity from the 2008 studies 977 showed that the directivity effect depends on the length sand not the normalized length X (Spudich and 978 Chiou (2008). As an example comparison of using normalized versus un-normalized rupture lengths for a 979 MS earthquake, the directivity from the Spudich and Chiou (2008) directivity model is compared to the 980 Abrahamson (2000) directivity model for T"3 seconds in Figure 6.5.1-1. The directivity effects from the 981 Abrahamson (2000) model are similar to the Spudich and Chiou (2008) for the 100 km rupture length for 982 X Cos(theta)>0.2. The Abrahamson (2000) model was based on numerical simulations for M7.5 strike-983 slip earthquakes. This figure shows that for longer or shorter rupture lengths, the older model based on 984 the normalized rupture lengths is not similar to the Spudich and Chiou (2008) model. 985 In addition to the effect of using un-normalized rupture lengths, Figure 6.5.1-1 also highlights the issue 986 of centering of the directivity. For MS, the Spudich and Chiou (2008) directivity model leads to positive 987 directivity effects for almost all rupture locations (all values of X cos(theta)); however, the GMPE models Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-31 Comment [alext74): 0479 "Comment [CDA175): 480 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 988 are developed to have near zero mean residual for large magnitudes. This indicates that the 2008 989 directivity models are not directly applicable to the GMPEs without centering the directivity model. 990 Chiou and Youngs (2014) addressed the issue of centering the directivity model by considering the 991 sampling of the directivity for stations in the empirical data set compared to the distribution of 992 993 994 995 996 directivity parameters for randomly located stations. In-depth discussions on the issue of centering can be also found in Spudich et al. (2014) and in Spudich and Chiou (2013). Because the candidate GMPEs tend to fit the same limited large magnitude data, the centering of the directivity model for the Chiou and Youngs (2014) dataset can be assumed to also represent the centering for the other NGA-West2 candidate GMPEs. For the non-NGA-West2 GMPEs used at DCPP (ASB14, ZH06 and ZLll), there are no 997 available evaluations of the centering of the datasets for directivity parameters. The Tl Team judged that 998 directivity effects should be considered in all the models, for application to DCPP, given the short 999 distances and large magnitudes of the controlling events; therefore, the Tl Team models apply the Chiou 1000 and Youngs (2014) directivity centering to all the common-form models even though they were 1001 developed from a combination of NGA-West2 and non-NGA-West2 proponent models. 1002 The key outcome of using this directivity model is that, for sites at the same closest distance, the median 1003 of the ground motion will vary for different locations along strike. That is, the GMPEs do not fully 1004 capture the scaling of the ground motion for sites located along the rupture (different directivity). 1005 Depending on the rupture and the site location, the directivity effect may increase or decrease the 1006 ground motion. Randomizing over the hypocenter location for the directivity implies variability in the 1007 median ground motions, which impacts the standard deviation. 1008 To simplify the application of the directivity model, Watson-Lamprey (2015) developed scale factors that 1009 describe the change in the median and total standard deviation as a function of the position along strike 1010 (Rv) and the distance perpendicular to the strike of the rupture (R,). The Chiou and Youngs (2014) 1011 directivity model could be used. but randomizing over the hypocenter would increase the hazard 1012 calculation time, while the Watson-Lamprey's models, which pre-calculated the effect of hypocenter 1013 randomization, expedites the calculation. In the Watson-Lamprey (2015) approach, the location of the 1014 hypocenter was randomized along the rupture, and the median and variability for the range of 1015 hypocenter locations was computed using the directivity effect predicted by Chiou and Youngs (2014), 1016 which is based on the directivity parameter OPP described in Chiou and Spudich (2013). The standard 1017 deviation reflects the variability of the random hypocenter on the rupture plane. This simplified model is 1018 applicable to both strike slip and dip slip earthquakes. 1019 A simplified method for directivity effects is described in Attachment C. and summarized in the following 1020 section. The equations for the preferred directivity model are also provided in the following section. 1021 6.5.l.l Watson-Lamprey (2015) Directivity Effects Model Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-32 .. Comment [CDA176): 481 .. Comment [CDA177): 482 .. Comment [CDA178]: 483 Comment [CDA179): 484 Comment [CDA180]: 478 ,. .. Comment [CDA181): 48& Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 1022 The Watson-Lamprey (2014) simplified implementation of directivity is documented in a PEER draft 1023 report that will be published in 2015. The basic steps followed by Watson-Lamprey {2015) do develop 1024 her model are described here. First, a suite of rupture geometries for strike-slip ruptures up to a 1025 moment magnitude of 8 and reverse ruptures up to a moment magnitude of 7.5 was created. Next, the 1026 mean and standard deviation of the change in the 5% damped pseudo-spectral acceleration at sites due 1027 to directivity by randomizing over hypocenters was calculated for a suite of sites out to a rupture 1028 distance of 70 km. The hypocenter randomization model for strike-slip ruptures was from Chiou and 1029 Youngs (2008b). For reverse ruptures, a new hypocenter distribution model was developed based on the 1030 hypocenters from large magnitude reverse events world-wide (see Attachment C, Section 4). 1031 Using the set of computed directivity factors, the mean and standard deviation of the change in the 5%-1032 damped pseudo-spectral acceleration was used to develop models for both strike-slip and reverse 1033 ruptures. The resulting factors for the median and standard deviation were fit to simple parametric 1034 models: for strike-slip earthquakes, the model parameters are rupture length, Rx and R,; for reverse 1035 earthquakes, the model parameters are rupture width, rupture length, dip, Rx and R,. Figure 6.5.1-2 1036 shows a schematic representation of the parameters utilized by the directivity model. 1037 An example of the scaling for a strike-slip fault with 80 km rupture length (M7) and a site located at an 1038 Rx value of 3 km is shown in Figure 6.5.1-3. For a site located at the center of the rupture {Rv=O), the 1039 median is slightly reduced and the additional variance term is slightly increased. For a site located at the 1040 end of the rupture (R,=40 km) both the median and variance are increased. This shows that the 1041 1042 1043 1044 1045 directivity effects will be strongest for sites located at the ends of large strike-slip ruptures in the case of treating the hypocenter position as random along the rupture. Attachment C has additional example cases. The functional form of the directivity adjustment for strike-slip earthquakes is given by: J;>IR_ss(M ,R111,,,R,,R,, l)= Factor,s(A1 ,R,,11.,R,,R,, *(M -c.,(T) y) xc. ,.,,,,..(T)T/)/I( R(RR/'P)T/)11< .\f(M) 1046 (Eq. 6.5-1) 1047 and the functional form for reverse earthquakes is given by: 1048 fmn_*i (114.RR{P*R,.R,.,W.l,Dip)= Factor.1.(.A.1,R111,.,R,.R., .. *(M -c.1,(T))') X Cg_rurw(T)T,)JR_l<(Rnr:P )T/)11<_.11 (M) 1049 (Eq. 6.5-2) 1050 where Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-33 Comment [CDA182]: 488 .. Comment [CDA183): 489 1051 1052 1053 1054 1055 1056 . (max(M-5.5,0) T01R .lf(M)= mml O.S ,l) Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 {Eq. 6.5-3) {Eq. 6.5-4) ,RRLr*R,,R,.L) = a0 +a1 (max( RyRatio *cos28,-0.5) )+ a2 (max ( J(vRatio

• cos20, -0.5) r + a_1 (max (Ry Ratio"' cos20, -0.5) r (Eq. 6.5-5) ----2 --1 --Fac:torw,(M .RRur* Rx, R,.W,L,Dip) = b0 +b1 cos2tP + b2cos2tP + bJcos2tP + b4cos28+ --2 ' b5cos20 + + b7RyRatio + (Eq. 6.5*6) Ri*Ra1io = min(fl.1) . l/2 {Eq. 6.5*7) 1057 For strike-slip sources, cos20 is the average value of ws20 evaluated over the length of the surface 1058 projection of the top of rupture and where (}is the angle between the ray from a point on the surface 1059 of rupture to the site and the ray from the same point along strike. This is calculated using the following 1060 equation: ( [R. + L/2)) __ R,.+Ll2-2IRxl*ArcTange/1f 'IR,I cos20 = * -L 1061 ( I I ( R. + U 2 )J R,. -LI 2-2 R, "'ArcTangent 'IR,I (Eq. 6.5-8) L 1062 For reverse sources, cos2¢' is the average value of cos2; evaluated in the plane perpendicular to 1063 rupture over the width of the rupture and where ,P is the angle between the ray from a point on the Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-34 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 1064 rupture to the site and the ray from the same point up dip. This is calculated using the following 106S equation: lr H .. + U 2 -2IH, cos( l)ip )I"' Arcfo11ge111( I H,. +. (U 2 ll )) __ , R., cos Dip cos2<1> = 1066 I. {Eq. 6.5-9) ( R, -LI 2-21Rxcos(Dip)I* )1)) L 1067 For reverse sources, cos2() is the average value of cos20 evaluated over the length of the surface 1068 projection of the top of rupture and where (}is the angle between the ray from a point on the surface 1069 of rupture to the site and the ray from the same point along strike. This is calculated using the following 1070 equation: r/C + l !2-2IR,sin(Dip)I* ArcTangem(1 R .. _+ __ R,sm Dip cos20 = l {Eq. 6.5*10) 1071 lt ( R, + U2 l) R:. -I. ! 2 -21 R., (Dip )I* A re Tange/11 IR., (Dip ll J I. 1072 The coefficients for the directivity effects for the median ground motion are listed in Table 6.5*1. 1073 1074 Table 6.5-1: Coefficients for directivity effect adjustments to the media for SS and REV earthquakes. Median for SS earthquakes Median for REV earthquakes Period* Period-Dependent Period* Period-Dependent Independent Coefficients Independent Coefficients Coefficients Coefficients ao *0.078101 Period (sec) Cs Csb bo *0.13414 Period {sec) Cs ratio Csb a1 *0.033923 O.ot 0.000 0.483 b1 0.022371 0,01 0.000 0.483 a2 0.20067 0.02 0.000 1.214 b2 0.047363 0.02 0.000 1.214 a1 0.149361 0.03 0.000 1.642 b1 0.02078 0.03 0.000 1.642 a"' -0.3004 0.05 0.000 2.181 b. 0.1042 0.05 0.000 2.181 0.075 0.000 2.609 bs 0.00716 O.D75 0.000 2.609 ---------*--*--0.1 0.000 2.912 b6 *0.1239 0.1 0.000 2.912 Chapter 6: GMC Models for the Median: Overview and Methodology Page 6*35 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 0.15 0.000 3.340 b1 0.069512 0.15 o.ooo 3.340 I 0.2 0.000 3.643 ba 0.076094 0.2 0.000 3.643 0.25 0.000 3.879 b .. -0.26717 0.25 0.000 3.879 0.3 0.000 4.071 0.3 0.000 4.071 0.4 0.000 4.375 0.4 0.000 4.375 0.5 0.460 4.610 0.5 0.460 4.610 ------*--*--0.75 0.920 5.038 0.75 0.920 5.038 1 1.000 5.341 1 1.000 5.341 1.5 1.000 5.769 1.5 1.000 5.769 2 1.000 6.072 2 1.000 6.072 3 1.000 6.500 3 1.000 6.500 4 1.000 6.804 4 1.000 6.804 5 1.000 7.039 5 1.000 7.039 7.5 1.000 7.467 7.5 1.000 7.467 10 1.000 7.770 10 1.000 7.770 The functional form of the directivity sigma adjustment for strike-slip earthquakes is given by: ,Rm., Rx, R,..L)-= Factor,,,\(M ,Rm., Rx, *(\rt -c.,,(T) Y) x )T,,,R_JJ (M) and the functional form for reverse earthquakes is given by: {Eq. 6.5-11) .1;>11, $/(; Rr(M, R/Ul"R" R_, .W,1., Dip)= Factorl,,.(M, R/U/>>R,, R_, .w, /.,Dip)cxpel" *(M -c\,(T) :Y) x c"-""'"(T)T,,,,,_"(Rm. )T,,,,,_ 1.1 (M) {Eq. 6.5-12) where {Eq. 6.5-13) . (max(M-5.5,0) l TmR_ii(M)= mml 0.8 ,lj {Eq. 6.5-14) Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-36 I 108S 1086 1087 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 ,R11,,P.Rx,R,,L) = a0 + a1 {max ( RyRatio *cos2{},-0.5)) + a2 (max ( RyRatio
• cos211,-0.5))2 + a1 (max( RyRaiio
• cos28,-0.5) r FactorR,*:I' (.1\1,R/(..,,,R,,R,.,W,L, Dip)= h0 + h1cos2,P + cos2/ + h_icos21/J' + + RvRatio = min(fu.1) . L/2 {Eq. 6.5-15) {Eq. 6.5-16) {Eq. 6.5-17) 1088 For strike-slip sources, ros2() is the average value of cos20 evaluated over the length of the surface 1089 projection of the top of rupture and where (}is the angle between the ray from a point on the surface 1090 of rupture to the site and the ray from the same point along strike. This is calculated using the following 1091 equation: __ (R, +Li 2-21Rxl
• ArcTangefll( cos20 = * -L 1092 ( I I ( R. + U 2 )) R,. -LI 2 -2 R,
• ArcTa11gent 'IR,I {Eq. 6.5-18) L 1093 1094 For reverse sources, cos2¢> is the average value of cos2; evaluated in the plane perpendicular to 1095 rupture over the width of the rupture and where ,P is the angle between the ray from a point on the 1096 rupture to the site and the ray from the same point up dip. This is calculated using the following 1097 equation: Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-37 1098 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 ( . I ( . )I ( R, +L/2 )) R, +Li 2-2 R, cos Dip
• ArcTnngent I * ( . )I __ . R, cos /)ip cos2ct> = L {Eq. 6.5-19) (R, -li2-2IR, cos(Dip)I* R, )1)J Rxcos Dip L 1099 For Reverse sources, cos20 is the average value of ws20 evaluated over the length of the surface 1100 projection of the top of rupture and where 0 is the angle between the ray from a point on the surface 1101 of rupture to the site and the ray from the same point along strike. This is calculated using the following 1102 equation: 1103 1104 1105 1106 1107 l( R., + l i 2-21R, sin (Dip )I* ArcTm1ge11/ r I R, )1)) __ * \ R,sm(D1p cos2(} = l ( R .. -li2-2IR, sin(Dip)I .. An:Tu11ge111(1 R, _+(l/.21)1 I\ R, sm Dip) , l {Eq. 6.5-20) {Eq. 6.5-21) {Eq. 6.5-22) 1108 The coefficients for the directivity effects for the sigma are listed in Table 6.5-2 (a and b). 1109 1110 1111 Table 6.5-2a: Coefficients for Directivity Adjustment Model for the Sigma Sigma for SS earthquakes Sigma for REV earthquakes Period-Period-Dependent Period-Period-Dependent Independent Coefficients Independent Coefficients Coefficients Coefficients Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-38 1112 ao 0.029001 Period (sec) Cs r,;itio 31 0.21112 O.ot 0.000 0.483 a, 0.53116 0.02 0.000 1.214 a3 -0.60145 0.03 0.000 1.642 aM -0.16960 0.05 0.000 2.181 O.Q75 0.000 2.609 -----0.1 0.000 2.912 0.15 0.000 3.340 0.2 0.000 3.643 0.25 0.000 3.879 0.3 0.000 4.071 0.4 0.000 4.375 0.5 0.460 4.610 0.75 0.920 5.038 1 1.000 5.341 1.5 1.000 5.769 2 1.000 6.072 3 1.000 6.500 4 1.000 6.804 5 1.000 7.039 7.5 1.000 7.467 10 1.000 7.770 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 bo 0.044478 Period (sec) Csrot;o b1 -0.021982 O.Ql 0.000 0.483 b, -0.025129 0.02 0.000 1.214 b3 0.020343 0.03 0.000 1.642 b. -0.022130 0.05 0.000 2.181 bs 0.030626 0.075 0.000 2.609 ---*--*--bM 0 0.1 0.000 2.912 0.15 0.000 3.340 0.2 0.000 3.643 0.25 0.000 3.879 0.3 0.000 4.071 0.4 0.000 4.375 I 0.5 0.460 4.610 0.75 0.920 5.038 1 1.000 5.341 1.5 1.000 5.769 2 1.000 6.072 3 1.000 6.500 4 1.000 6.804 5 1.000 7.039 7.5 1.000 7.467 10 1.000 7.770 Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-39 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 1113 Table 6.5-Zb: Coefficients for Directivity Adjustment Model for the Sigma Period (sec) ()C/1.1.\Wi 0.0. 2.0 0 3 0.1205 4 0.1535 5 0.1913 -*--7.5 0.2285 10 0.2478 1114 *Comment [CDA184]: 1033part1 1115 6.5.2 Tl Team's Evaluation of Directivity Scaling Models 1116 The Tl Team evaluated the simplified approach to directivity described in Section 6.5.1.1 and the 1117 evaluations are summarized below. 1118 The advantage of the Watson-Lamprey (2015) model is that it evaluates the net effect of variability in 1119 hypocenters on the directivity parameter rather than requiring a direct integration over hypocenter 1120 location for the hazard calculation. It has also estimates the impact on the standard deviation of other 1121 GMPEs in addition to the CY14 model. The model represents in average effects of directivity over the 1122 four NGA-West2 models. 1123 Limitations of the Watson-Lamprey (2015) model are that: 1124 1. It is only for straight faults; 1125 2. It applies the CY14 directivity to other GMPEs; 1126 3. It uses the changes to the standard deviation in the CY14 model to scale the standard 1127 1128 1129 deviations from the other GMPEs, and 4. The review of the Watson-Lamprey (2015) model for publication as PEER report is not complete and the model in still draft. 1130 There are two major assumptions that are made in applying the CY14 centered directivity model to the 1131 GMPEs used in the DCPP GMC model: (1) that the large-magnitude distribution is similar amongst the 1132 NGA-West2 GMPEs so that similar directivity effects can be expected, and (2) that the centered CY14 1133 model can be applied to the NGA-West2 GMPEs to model these effects. Considering the similarities of 1134 the large-magnitude short-distance data used by the various modelers, the Tl Team's judgment is that 1135 the directivity effects will not become significant to hazard if separate centering models were developed 1136 for each GMPEs. PEER plans to develop GMPEs including directivity effects which are centered for each Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-40 *Comment [CDA185]: 486 Comment [CDA186): 1033 patt 2 1137 1138 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 individual GMPE. This work is currently scheduled to be completed in 2017. It is beyond the scope of SWUS to develop these models. 1139 Because the Watson-Lamprey model is still in a draft report, the Tl team conducted simple checks to 1140 show that the results from the recommended model are reasonable in that they are consistent with the 1141 range of directivity effects from other directivity models, such as those shown in Figure 6.5.1-1. Because 1142 the long-period hazard at DCPP is controlled by the Hosgri fault (Section 4.1.4), the main concern for 1143 application of the directivity models is for strike-slip earthquakes. The DCPP site is not located up-dip 1144 from the Los Osos fault, so directivity effects from the dip-slip Los Osos fault would not be large. 1145 Figure 6.5.1-3 shows the Watson-Lamprey model for M7 earthquakes with an 80 km rupture on a strike-1146 slip fault for two sites at an Rx distance of 3 km: a site located at the end of the rupture (Rv=40) and a 1147 site located at the center of the rupture (R,=O). At a period of 3 seconds, the median directivity term for 1148 a site located at the end of the rupture is 0.18 (or a factor 1.2). At the center of the rupture, the 1149 directivity factor is -0.07 (factor of 0.93). Using the previous directivity models shown in Figure 6.5.1-1. 1150 for a 100 km long fault, the Spudich and Chiou (2008) model has a maximum directivity factor for T=3 1151 sec of 1.5 and a minimum factor of 0.9. If the Spudich and Chiou (2008) model was centered so that 1152 the mean factor was about 1.0, then the range would be about 0.7 to 1.3. 1153 The Spudich and Chiou (2008) model is for a specified hypocenter location, while the Watson-Lamprey 1154 model is the average for a randomized hypocenter. The average directivity factor of 1.2 from the 1155 Watson-Lamprey model for sites located at the end of the rupture is in the upper range of the Spudich 1156 and Chiou model. At the center of the rupture, the Watson-Lamprey model has an average directivity 1157 factor of 0.93, which is consistent with sites near the center of the rupture having slightly below average 1158 because the ruptures will, on average, be away from the center. The standard deviation of the 1159 directivity factor is 0.15 for the site at the end of the rupture. This is consistent with a range of+/- 30 % {+/- 1160 0.28 in In units) if we take the full range to be about+/- 2 standard deviations. 1161 Based on this simple comparison, the Tl Team judged that the directivity scaling in the Watson-Lamprey 1162 simplified implementation are consistent with previous models and are reasonable for application even 1163 though the documentation of the model has not been finalized in a final PEER report. This model has a 1164 1165 1166 large advantage in terms of the required computation time for hazard calculations because the randomization of the hypocenters is done outside of the hazard calculation. The hazard sensitivity results in Section 14.2.1 showed that including or not including the directivity 1167 effect had a small impact on the hazard. 1168 The Tl Team's judgment is that, given the small effect on the hazard at DCPP (less than 2%), using simple 1169 checks is justified because even if the Watson-Lamprey model is off by a factor of 2, there would still be 1170 only a small effect on the hazard (less than 4%). Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-41 .. Comment [CDA187): 1034 Comment [CDA188): 1033 pan 3 Comment [CDA189]: 49Q Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 1171 This conclusion that the directivity effect on the DCPP hazard is small is based on using the Watson-1172 Lamprey model to do the hazard runs. So if the Watson-Lamprey model is wrong, it is not a valid check. 1173 The Tl Team's simple checks provide confidence that the Watson-Lamprey model is reasonable for the 1174 cases that control the hazard at DCPP. 1175 Because (1) the Watson-Lamprey model is still under review a PEER, (2) the effect on the hazard at DCPP 1176 is small, (3) questions about the applicability of the CY14 centering and directivity models to other 1177 GMPEs, and (4) large increase in hazard run times with little expected effect if the CY14 directivity model 1178 is implemented in the hazard integral, the Tl Team judged that it would be better to remove the 1179 directivity model from the DCP P model. 1180 By excluding the directivity adjustment model in the logic trees for both sites has an implicit assumption 1181 that the median directivity effect is zero and the variability of the ground motion due to directivity is 1182 captured by the standard deviation by the GMPEs for the two sites. The basis for this assumption is 1183 discussed below. 1184 The standard deviation of GMPEs is due to the simplification of the source, path, and site effects (the 1185 single-station sigma approach is used which removes the simplification for site effects, so all that 1186 remains is the source and path). A l<ey assumption in using the single-station standard deviation from 1187 empirical GMPEs for hazard calculations is that the data used to develop the GMPEs are a representative 1188 range of other aspects of the source and path that are not captured in the simple parameters used in 1189 the GMPEs. This would include the location of the hypocenter (e.g. directivity), slip distribution, rupture 1190 velocity, rise time (or complete slip time function), and 3-D crustal path effects. Directivity is just one of 1191 the parameters that is assumed to be representatively sampled in the empirical data. 1192 In magnitude-distance ranges for which there are large numbers of recordings, forward, neutral and 1193 backward directivity conditions are all sampled. The Tl Team assumes that the sampled distribution is 1194 representative of the distribution of future earthquakes. 1195 In magnitude-distance ranges for which there are fewer data (e.g. large magnitudes at short distance), it 1196 is less likely that the distribution of directivity effects in available empirical data set is representative of 1197 1198 1199 the distribution of directivity effects for a future earthquake at a specific site. For this reason, the Tl Team used the Watson-Lamprey simplified model to check this for DCPP site, which has nearby faults. The hazard results showed for that for DCPP site, the impact of using the distribution of directivity 1200 effects based on the CY14 parameterization (as simplified by Watson-Lamprey), was almost the same 1201 (less than 2% difference) as using the distribution in the data used by the GMPEs. 1202 1203 1204 Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-42 . Comment [CDA190): 1035 1945 >. ....... *::;: u 2.5 2 0 0.5 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 Somerville et al (1997) Abrahamson (2000) Spudich and Chiou (2008) -400 km rupture Spudich and Chiou (2008) -100 km rupture Spudich and Chiou (2008) -30 km rupture .... . -. . .... .. .. 0 0 0.1 0.2 0.3 0.4 0.5 0.6 X cos(theta) 0.7 0.8 0.9 1946 Figure 6.5.1-1: Comparison of directivity from the normalized rupture length models (Somerville et al., 1947 1997; Abrahamson, 2000) and the un-normalized rupture length model of Spudich and Chiou (2008). 1948 1949 1950 1951 1952 Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-123 a) Plan view *Rx +Rx Length Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 bJ Cross sec11on 1953 ----1954 1955 Figure 6.5.1*2; Parameters for the directivity models. 1956 1957 1958 1959 1960 1961 -0.2 en -'E ::J 0. 1 5 +-----I c:: -Ay=O. M7 (med_fac) Ay=O. M7 (sigma_fac} Ay=40, M7 (med_fac) Ay=40, M7 (sigma_fac) E ... 0.05-+--------------+*+--------< >. -*::; :;:::: (,) 0 -0.05 -0.1 0.01 0.1 .......... 1 10 Period (sec) Figure 6.5.1-3: Example of the directivity model scaling for an 80 km long strike*slip fault and a site located at Rx" 3 km. The effects on median ground motion and sigma are shown for two sites located at the center of the rupture (R," O km) and at the end of the rupture (R," 40 km). Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-124 Comment Number 1036 -Evaluation of Common-form suite: Chapter 8, Lines 305-308 PPRP Comment: Please revise this passage to emphasize that these simplified hazard comparisons are not the primary basis for evaluating the common-form suite of representative models (which, though it should be hazard informed, should not be hazard calibrated, i.e., it is required to cover the CBR of the TDI of ground motion, not hazard). It appears that the simplified hazard comparisons are actually being used as a final check to ensure that occasional small excursions of the candidate GMPE estimates (with added epistemic uncertainty) do no carry unexpectedly high leverage with respect to hazard. If that is the case, please reframe the discussion to clarify that. The additional discussion should emphasize this point by summarizing the non-hazard-based justification for accepting a suite of common-form models that does not fully envelop the predictions of the candidate GMPEs (all of which were considered to be credible--i.e., they passed the test by the Tl Team of being technically defensible interpretations). Tl TEAM -PM Reply: We agree that the justification in terms of CBR of the TDI should be provided, with the added qualifier that the CBR of the TDI needs to be captured for the range of scenarios (magnitude and distance) that contribute significantly to the hazard. We evaluate if we captured the CBR of the TDI for the hazard relevant sources by using hazard calculations based on representative SSC models. Text in Chapter 8 was modified to discuss that the smoother common-form models are adequate because they cover the CBR of the TDI (i.e. candidate GMPEs) for scenarios that are relevant to the hazard. In some magnitude-distance combinations, the suite of common-form models do not fully envelop the prediction of the candidate GMPEs with added epistemic uncertainty, as discussed in the next paragraph. To check that these small exeedances are not at scenarios that control the hazard, the hazard is evaluated using a representative SSC model. These representative hazard results show that the common-form models have an appropriate range (shown later in this section)." Excerpt of Chapter 8, Section 8.4.3 follows in the following pages.

Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 272 8.4.3 Evaluation of Center and Body of the Selected Models 273 The center and body of the distribution of the medians is evaluated by comparing the COFs using the 274 weights described in Section 8.4.2 with the CDF from the candidate GMPEs with epistemic uncertainty 275 (see Figures 8.4-4 and 8.4-5 as examples). Figure 8.4-4 shows CDF for PGA for an M6.5 strike-slip 276 earthquake for a site at Rx"-5 km (on FW). The selected weights (red curve) has a center (CDF "0.5) that 277 is about 0.2 In units greater than the center of the CDF from the finite-fault simulations, about 0.12 units 278 above the GMPEs, and is similar to the CDFs based on the mean residual, prior and likelihood 279 approaches. The average slope of the CDF between CDF"0.1 and CDF"0.9 defines the body of the 280 distribution and, overall, is consistent with the slopes from the other methods eKcept for the GMPE and 281 likelihood approaches which are steeper for this example. These comparisons of the center and body of 282 the distribution change for different scenarios and spectral periods. 283 In addition to the CDF plots, the center and body of the distribution can be evaluated using distance 284 scaling, magnitude scaling, and spectra plots. Figures 8.4-6 and 8.4-7 compare the distance scaling for 285 the 51", so11** and 95'11 fractiles from the logic tree weights with the distance scaling for the candidate 286 GMPEs for PGA and PSA (T"l sec), respectively. The 501h percentile for the selected common-from 287 models is not the same as the so1* percentile of the candidate GMPEs. One reason for this difference is 288 289 that the common-form model weights were partly based on finite-fault simulations that were not part of the dataset used in the candidate GMPEs' derivation. 290 As seen in these figures, the selected models envelope the candidate GMPEs for the larger magnitudes 291 (M6.5 and M7.5) other than at distances less than 3 km. The GMPE that is above the selected model 292 envelope is the ld14 model. As noted in Section 6.2.1, the Tl Team judged the short distance scaling in 293 the ld14 model to be unreliable for large magnitudes and removed the ld14 model at distances less than 294 3 km from the development of the common form models. This apparent inconsistency between the 295 range of GMPEs and the range of the selected common form models reflects the Tl Team's judgment 296 with regard to the ld14 GMPE. The shape of the 5% fractiles for M7.5 shown in Figure 8.4-6 is not 297 smooth due to the relatively small number of common-form models selected (less than 31). 298 At smaller magnitudes (MS.5), the selected common form models do not envelope all of the candidate 299 GMPEs for M5.5 as shown in Figure 8.4-7 (top panel). The differences at M5.5 are related to the sharp 300 breaks in the magnitude scaling for the short period ground motion for some of the candidate GMPEs. 301 Figure 8.4-8 shows the magnitude scaling for strike-slip earthquakes for an Rx distance of 5 km for PGA, 302 T=0.2, T=l, and T=3 seconds. The sharp breaks in the magnitude scaling at MS.5 for one of the GMPEs 303 can be seen in this figure. The selected common form models include breaks in the magnitude scaling at 304 M5.5 and M6.S, but the break is not as sharp and leads to a smoother set of models. The Tl Team judged 305 that the smoother common-form models are adequate because they cover the CBR of the TDI (i.e. 306 candidate GMPEs) for scenarios that are relevant to the hazard. In some magnitude-distance 307 combinations, the suite of common-form models do not fully envelop the prediction of the candidate Chapter 8: Median GMC Models: DCPP Sources Page 8-9 Comment [CDA42): 595 Comment [CDA43]: 596 Comment (CDA44): S97 " Comment [CDA45): 599 Comment [CDA46]: 600 "Comment [CDA47): 593 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 308 GMPEs with added epistemic uncertainty, as discussed in the next paragraph. To check that these small 309 exeedances are not at scenarios that control the hazard, the hazard is evaluated using a representative 310 SSC model. These representative hazard results show that the common-form models have an 311 appropriate range (shown later in this section). 312 Examples of the spectra for M5.S, MG.5, and M7.5 strike-slip earthquakes at a distance of S km are 313 314 315 compared to the range of the candidate GMPEs plus additional epistemic uncertainty in Figure 8.4-9. For M6.5 and M7.5, the selected models envelop the range of the candidate GMPEs plus additional epistemic uncertainty, but at M5.5, not all of the models are enveloped due to the sharp breaks in the 316 magnitude scaling at MS.Sin one of the GMPE models. This issue of adequate range is evaluated later at 317 the end of Section 8.4.3, using hazard curves as the metric of interest. 318 An example of the CDF with a broad distribution of the GMPEs is shown in Figure 8.4-10 for a M5.5 319 earthquake at a distance of 1 km. For the spectral acceleration at T=l sec, the GMPE distribution is 320 much broader than the distribution for the selected models due to the kink in the magnitude scaling at 321 M5.5 for one of the candidate GMPEs. In contrast for PGA, for this same scenario, the GMPE 322 distribution is similar to the selected models as the range of the selected models captures the kink in the 323 magnitude scaling. 324 The centering of the models can also be evaluated in terms of the influence of the different metrics used 325 for computing the weights for the common-form models. Because the simulations are also used to 326 constrain the center and body of the distribution, differences between the center of the simulations and 327 the center of the candidate GMPEs will affect the centering of the selected models. 328 A set of CDF plots and ground motion scaling plots for the scenarios listed in Table 8.4-1 and for a range 329 of spectral periods are shown in Appendix H. The CDFs of the ground motions were reviewed to check 330 the center and body of the distributions. A general result is that the simulations lead to a lower center 331 (PSA at CDF=0.5) for short periods and a higher center for long periods. The center of the full 332 distribution and the body of the upper tail distribution of the selected common-form models are 333 consistent with the distribution of the GMPEs except at an R, distance of 1 km from M5.5 earthquakes. 334 The lower tail has more variability in the shape of the CDF, but it is not as important to the hazard as the 335 upper tail. (The mean hazard is driven by the upper tail because the distribution is skewed. 336 To summarize the evaluation of the centering of the models based on the CDF plots, the changes in the 337 PSA at CDF=0.5 for the different metrics and datasets are computed. Specifically, for each scenario listed 338 in Table 8.4-1, the difference in the ground motion for a single metric and the weighted average model 339 is computed. The distribution of the differences of the In PSA for the 18 scenarios is referred to as an 340 "influence histogram", and is plotted for each statistic and each spectral period. Examples for the R,.,.-341 based models (A models) are shown in Figures 8.4-11, 8.4-12, and 8.4-13 for PGA, and spectral 342 accelerations at T=l sec and T=3 sec, respectively. These plots show the influence of the different Chapter 8: Median GMC Models: DCPP Sources Page 8-10 .. Comment [CDA48): 1036 .. Comment [CDA49): 604 Comment [CDASO]: 601 Comment [CDAS1]: 605

• Comment [CDAS2]: 606 .. Comment [CDA53): 607 Comment Number 1037 -Evaluation of Common-form suite: Chapter 9, Lines 301-313 PPRP Comment: Although it is reasonable to use the hazard as a guide in determining whether the representative models produce a wide enough hazard distribution, it seems appropriate that the distribution of the ground motion models should also be wide enough to encompass the candidate models and their epistemic uncertainty. Please explain that both of these distributions were checked and that the hazard distribution alone is not being used to judge whether the representative suite of models represents the CBR (especially the range) of the ground motion distribution, which should be the intent of a SSHAC Level 3 ground motion study. Tl TEAM -PM Reply: The goal of the SSHAC evaluation is develop a set of ground motion models that capture the CBR of TOI for scenarios that are relevant to the hazard. If the GM models capture the CBR for all scenarios. then it will also capture the range of the hazard. If the range of the GM models does not fully capture the range for all scenarios, then the range of hazard may or may not be captured. Because our model does not capture the full range of the ground motion from the candidate GMPEs with additional (2 sigma) for every scenario, we needed to check that the range of hazard was captured. The main evaluation was in the ground motion space. In developing our weights for the alternative weights approaches (prior, residual, likelihood, data sets), we explicitly evaluated the GM-based CDF and chose a weighting scheme for the weighting approaches that lead to a CDF with an appropriate shape of the CDF (body of the distribution) in addition to the 5th and 95th fractiles (range of the CDF). We then evaluated the range of the hazard as a check that the range of the hazard-significant scenarios is captured. The hazard evaluation is just a check that the approach used to set the weights for weighting approaches, which control the full distribution (CBR), does not miss the range of a key contributor to the hazard. To summarize the comparison of the range from the common-form models and the range from the GMPEs, we added new plots showing the histogram of PSA ratios between the 95th percentile from common-form models and the 95th percentile from the candidate GMPEs (plus epistemic uncertainty). A similar set of plots was prepared for the 5th percentile. Augmented discussion is incorporated in Chapter 6, Section 6.4.5.4. Excerpt of Chapter 6, Section 6.4.5.4 and associated figures follows in the following pages.

Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 892 From the CDF of the ground-motion distribution based on the total weights, the 0.05, 0.5 and 0.95 893 quantiles are calculated, as well as for the candidate GMPE distribution. The candidate GMPEs are 894 equally weighted (as described above). while the common-form model distribution is based on the 895 selected models and total weights. This allows comparing the width and range of the distribution of the 896 selected common-form models and the candidate GMPEs. 897 Figure 6.4.5-3 shows the 0.05, 0.5 and 0.95 quantiles distributions for Model A and for the PVNGS 898 application, for M6.0, normal faulting cases, at T = 0.01 sec, plotted against distance. Figure 6.4.5*4 899 shows the quantiles for the PVNGS (Model A) normal faulting cases, at T = 0.01 sec, plotted against 900 moment magnitude. Figure 6.4.5-5 shows the PSA 0.05, 0.5 and 0.95 quantiles distributions for PVNGS 901 (Model A), for M6.0, strike*slip cases, at R, = *15 km, plotted against periods. The range of the 0.05 to 902 0.95 quantiles from the common*form models is similar to the range from the candidate GMPEs. For 903 some cases, the 0.05 quantile is less stable, leading to a distribution that is skewed to lower values. This 904 905 is not significant for the hazard because the mean hazard is controlled by the upper tail of the motion distribution. 906 AppendiJC H includes several plots showing the 0.05, 0.5 and 0.95 quantiles distributions versus distance 907 and magnitude, for several magnitude and distance values, respectively, in Sections 2.1.6 and 2.1.8 for 908 DCPP (Model A), in 3.1.6 and 3.1.8 for PVNGS (Model A), and 4.1.6 and 4.1.8 for PVNGS (Model B). In 909 addition, the 0.05, 0.5, 0.95 quantiles are plotted against periods, for several scenarios, in Sections 2.1.9, 910 3.1.9 and 4.1.9 of AppendiJC H. 911 6.4.5.4 Range of Distribution 912 To assess the width of the common-form model distribution, the ratios of the 0.05/0.5 and 0.95/0.5 913 quantiles are plotted against distance, for several magnitudes. This is an indicator of possible skewness 914 of the model distribution. 915 Figure 6.4.5-6 shows an el<ample of the 0.05/0.5 and 0.95/0.5 quantiles ratios for Model A and for 916 PVNGS, Rx=-15 km, normal style of faulting, for all periods, and MS (top), M6 (center), and M7 (bottom). 917 The quantile ratios show a broadening of the uncertainty as distance increases from 1 to 50 km, which is 918 counter-intuitive as there is more data in the 30-50 km range than the 1-5 km range for constraining 919 GMPEs. The reason for this increase is that the suite of candidate GMPEs has different distance scaling, 920 as discussed in Section 6.4.5.5. 921 Appendix H includes several plots showing ratios of the 0.05/0.5 and 0.95/0.5 quantiles versus distance 922 for various periods for PVNGS and DCPP, respectively, in Sections 2.1.10, 3.1.10 and 4.1.10. Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-29 Comment [CDA170]: 47S "Comment [CDA171): 464 .. Comment [CDA172]: 463 aod 477 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 923 Although the ranges from the common-form models do not bound the ranges from the GMPEs with 924 additional epistemic uncertainty for all scenarios. the ranges of the st* and 95111 fractiles for the 925 common-form models are, on average, wider than the ranges of the 5th and 95111 fractiles for the GMPEs. 926 The fractiles for the common-form models are based on the weights from the logic trees. The fractiles 927 for the GMPEs with additional epistemic uncertainty are based on using equal weight for each candidate 928 GMPE and using weights of 0.8, 0.1, and 0.1 for the original GMPE and the plus and minus 2 sigma levels 929 for the additional epistemic uncertainty. 930 The histogram of the ratios of the 95** fractiles from the common-form models to the 95** fractiles of 931 the GMPEs for DCPP for strike-slip earthquakes is shown in the top frames of Figure 6.4.5-7. All of the 932 spectral periods are included in the histogram. The lower frame shows the ratios of the 5th fractiles. 933 The histograms for the 95** fractiles are centered on values greater than 0, indicating that the 95** 934 fractiles for the common-form models are, on average, higher than the 95** fractile for the GMPEs. The 935 histograms for the 5'11 fractile are centered on values less than 0, indicating that the 51" fractiles for the 936 common-form models are, on average, lower than the 5** fractile for the GMPEs. This indicates that the 937 common-form models are, on average, yielding a wider range than the candidate GMPEs, but they are 938 not broader for every scenario. 939 Similar histograms of the ratios of the 95** fractiles and 5t* fractiles are shown in Figure 6.4.5-8 for DCPP 940 for reverse earthquakes. The histograms for PVNGS are shown in Figures 6.4.5-9 and 6.4.5-10 for RRuP-941 based models for strike-slip and normal earthquakes, and in Figures 6.4.5-11 and 6.4.5-12 for R18-based 942 models for strike-slip and normal earthquakes. In all of the plots, the histograms are shifted to wider 943 distributions for the common-form models, but for the R,A-based models, the shift is small. 944 There are some scenarios for which the GMPEs give a wider range than the common-form models in all 945 of the plots. Part of the Tl Team's evaluation is to set weights for the common-from models which are 946 not just based on equal weight to each GMPE. Using different weights, the s** and 95*h fractiles for the 947 GMPEs are expected to be different from the fractiles for the common-form models. Also, the shapes of 948 CDFs of the common-form models (e.g. Figures 6.4.5*2 a through c), tend to be smoother than the 949 shapes of the CDFS for the common-form models. The less smooth CDFs of the GMPEs leads to some 950 cases for which the GMPE fractiles are broader than the common-form model fractiles. 951 6.4.5.5 Epistemic Uncertainty in Distance and Magnitude Scaling 952 Figures 6.4.5-13 and 6.4.5-14 show range of distance and magnitude scaling in the selected common-953 form models for PVNGS (Model A), normal style of faulting, and T = 0.01 sec, compared to the scaling of 954 the candidate GMPEs and the candidate GMPEs with epistemic uncertainty. The epistemic uncertainty 955 of magnitude and distance scaling which is contained in the models is assessed by calculating the ratios Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-30 .. Comment [CDA173]: 1037 3C* T =ALL sof = o DCPP4 ModelA 2C t..: *c C* -0.2 -0.1 1861 T =ALL 2C* sof = o DCPP4 ModelA t..: *c C* 1862 0.0 0.1 -0 2 C.O Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 i::*.3 C.-1 02 lnnatio 1863 Figure 6.4.5-7: Ln ratio of the s'" and 95'" fractile of the median spectral acceleration from the common 1864 for models to the 51* and 951" fractile of the median spectral acceleration from the GMPEs with 1865 additional epistemic uncertainty (assuming equal weight to each GMPE). Top frame is for the histogram 1866 of the In ratios of the 95'" fractile for DCPP for strike-slip earthquakes. Bottom frame is for the histogram 1867 of the In ratios of the 511' fractile for DCPP for strike-slip earthquakes. Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-114 T =ALL *IC sof = 1 DCPP4 3C* ModelA t..: 2C *c C* -C.3 -0 2 1868 3C T =ALL sof = 1 DCPP4 2C ModelA t..: *:: *c* C* -C.5 -0 4 1869 -:: , Q.{l i::0.1 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 0.2 C.3 Int ratio 1 -0 3 -0.2 -0 1 c*.O C. 1 02 lnnatio 1870 Figure 6.4.5-8: Ln ratio of the s'" and 95'" fractile of the median spectral acceleration from the common 1871 for models to the 511' and 951" fractile of the median spectral acceleration from the GMPEs with 1872 additional epistemic uncertainty (assuming equal weight to each GMPE). Top frame is for the histogram 1873 of the In ratios of the 95"* fractile for DCPP from reverse earthquakes. Bottom frame is for the histogram 1874 of the In ratios of the s'" fractile for DCPP for reverse earthquakes. Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-115 T =ALL sof = o PVNGS2 *IC ModelA t..: j() 2C *c* C* -C.2 1875 f1C T =ALL sof = o *IC PVNGS2 ModelA j() t..: 2C* 'C* C* -C.f> 1876 0.0 0 00 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 0 *! Int ratio 1 -02 C.O lnnatio 1877 Figure 6.4.5-9: Ln ratio of the s'" and 95'" fractile of the median spectral acceleration from the common 1878 for models to the 511' and 951" fractile of the median spectral acceleration from the GMPEs with 1879 additional epistemic uncertainty (assuming equal weight to each GMPE). Top frame is for the histogram 1880 of the In ratios of the 95'" fractile for PVNGS for strike-slip earthquakes, RRup-based models. Bottom 1881 frame is for the histogram of the In ratios of the s'" fractile for PVNGS for strike-slip earthquakes, R<u,-1882 based models. Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-116 1883 1884 1885 1886 1887 1888 1889 1890 1891 GC* *IC t..: )C 2() *c* C* *IC* 3C* t..: 2C* 'C* C* T =ALL sot= 1 PVNGS2 ModelA -0 3 -C-.2 T =ALL sot= 1 PVNGS2 ModelA -:: , 0.0 0.1 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 02 OJ C.-1 -OG 0 2 C.O 0 2 CA lnnatio Figure 6.4.5-10: Ln ratio of the s'" and 95'" fractile of the median spectral acceleration from the common for models to the 511' and 951" fractile of the median spectral acceleration from the GMPEs with additional epistemic uncertainty (assuming equal weight to each GMPE). Top frame is for the histogram of the In ratios of the 95'" fractile for PVNGS for normal earthquakes, R*ur-based models. Bottom frame is for the histogram of the In ratios of the s'" fractile for PVNGS for normal earthquakes, R1,up*based models. Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-117 7C* GC 5C* *IC t..: 3C* 2C* *c C* -C.2 1892 GC* *IC* t..: 3C* 2C *c C* -C.6 1893 T =ALL sof = o PVNGS2 ModelB -C .* T =ALL sof = o PVNGS2 ModelB -C.*1 -0 2 c*.O Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 ().\ C.5 C.2 lnnatio 1894 Figure 6.4.5-11: Ln ratio of the s'" and 95'" fractile of the median spectral acceleration from the common 189S for models to the 511' and 951" fractile of the median spectral acceleration from the GMPEs with 1896 additional epistemic uncertainty (assuming equal weight to each GMPE). Top frame is for the histogram 1897 of the In ratios of the 95'" fractile for PVNGS for strike-slip earthquakes, R18-based models. Bottom frame 1898 is for the histogram of the In ratios of the 511, fractile for PVNGS for strike*slip earthquakes, R1,.-ba.sed 1899 models. 1900 Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-118 T =ALL 6C* sot= 1 5C* PVNGS2 ModelB -IC t..: '.>C 2C *c* C* -'::0.2 1901 T =ALL 4C sot= 1 PVNGS2 3C* ModelB t..: 2C* *c C* -'J 6 1902 -JC Q/ Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 0.-1 Int ratio 1 -0 .; --:*. 2 0 0 2 lnnatio 1903 Figure 6.4.5-12: Ln ratio of the s'" and 95'" fractile of the median spectral acceleration from the common 1904 for models to the to the 51" and 951" fractile of the median spectral acceleration from the GMPEs with 1905 additional epistemic uncertainty (assuming equal weight to each GMPE). Top frame is for the histogram 1906 of the In ratios of the 95'" fractile for PVNGS tor normal earthquakes, R,8*based models. Bottom frame is 1907 for the histogram of the In ratios of the s'" fractile for PVNGS for normal earthquakes, Rw*based models. 1908 1909 1910 Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-119 Comment Number 1038 -Short-range saturation: Chapter 6, Lines 40-41 PPRP Comment: Please reconcile the statement that the finite-fault simulations "all show saturation at short distances" with the statement on Line 697 of Appendix J (and evidence in Figure J.4.3-1) that "the GMPEs have stronger saturation than the EXSIM model at very close distances." If it is correct that EXSIM has less saturation at short distances, please explain why this should not be interpreted as support for the ld14 model (e.g., is the formulation of EXSIM such that it is not intended by its developers for use at the shortest distances? Or does the Tl Team argue on physical grounds that EXSIM is not reliable at short distances?). Tl TEAM -PM Reply: The first part of the question points at an internal inconsistency between Chapter 6 and Appendix J, which the Tl Team also acknowledges. Edits were provided to Chapter 6 to improve clarity. The Tl Team notes that there is no specific mention of saturation issues with EXSIM at distances less than 5 km in Assatourians and Atkinson (2015), Venier and Atkinson (2014), nor the earlier papers. Thus the only citation appears to be her comments at our special working meeting, and a recent email communication: Since Gail Atkinson has indicated at the January 28-29, 2014 special working meeting, and also in subsequent email correspondence that the method does not saturate as strongly as observations for distances less than 5 km. the method is deemed less reliable in this distance range and therefore cannot be used as an argument for ld14 and very near distances. Lastly, the Tl Team remarks that EXSIM is not used in the Sammon's map approach to generate a suite of common-form models, instead is used for residuals (together with the other two validated FFS simulations methods) in the weighting scheme. As a result, its behavior to short distance and high frequency does not impact the residuals too much. On the contrary, the ld14 model is used in the generation of the base model via Sammon's map, so the Tl Team's assessment of the unreliable M-R range has important downstream effects in the generation of reliable suite of the common-form models. Comment Number 1039 -Short-range saturation: Chapter 6, Lines 47-61 and Figure 6.2.1-2 PPRP Comment: The 1014 model was deemed unreliable by the Tl Team in the range of M 7.5 and Rs 3km. The description of the Tl Team's justification is based mainly on the interpretation that 1014's predicted median PGA is an outlier (it is higher by about 40% than the predictions of other candidate GMPEs). However, the predicted median at Rs 3km for T = 2s from the ZL 11 and the ZH06 GMPEs are also much higher than the other GMPEs (by more than 50%), but neither were rejected (Figure 6.2.1-2). Please justify the seemingly inconsistent assessments. Tl TEAM -PM Reply: The reason for rejecting ld14 and not ZH06 and ZL 11 is the following: ZH06 and ZL 11 are much higher than the other GMPEs over a wide distance range, whereas the ld14 model is much higher only at short distance range. Because the 1014 model is based on a much smaller number of near-fault data (due to restricting the data to VS30>450 m/s), there is much less constraint on the short-distance scaling. The Tl team judged that the distance scaling for large magnitudes is not as well constrained in the 1014 model as it is in the other NGA-E2 GMPEs which had the advantage of using the much larger data set that included soil data at short distances. The Tl team judged that the overall higher level of ground motion in the ZH06 and ZL 11 represented credible alternative scaling models that should be included. Explanatory text was added to Chapter 6. Excerpt of Chapter 6, Section 6.2.1 and associated figures follows in the following pages. Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 1 6 GMC MODELS FOR THE MEDIAN: OVERVIEW AND 2 METHODOLOGY 3 4 6.1 Introduction S This Chapter describes the evaluations of the candidate GMPEs selected for the median ground motion 6 compiled in Section 5.5. In addition, the alternative adjustment factors to account for hanging-wall 7 effects, directivity effects, and path effects on the median are described and evaluated. The evaluations 8 of the weights for the logic trees for the median for DCPP and PVNGS are described in Chapters 8 and 9, 9 respectively. 10 A new methodology is used to develop the suite of alternative median models based on the Sammon'.s 11 map representation of the alternative magnitude and distance scaling of the GMPEs. The Sammon's 12 map method is described in Attachment E. In this approach, the selected candidate GMPEs are 13 expanded to develop continuous distributions of the median GMPEs which can then be discretized into 14 representative models that are mutually exclusive and collectively exhaustive. This new method, 15 described in Section 6.4, allows the Tl Team evaluations to better capture the center, body and range of 16 median GMPE predictions. The application of the Sammon's map is limited to 17 periods ranging 17 between 0.01 (PGA) and 3 seconds, listed in Table 6.1-1. The spectral accelerations for the suite of 18 median models for periods above 3 seconds are based on the period scaling of NGA-West2 GMPEs 19 beyond 3 seconds, as described in Appendix N. 20 21 6.2 Evaluation of Candidate GMPEs for the Median 22 6.2.1 Evaluation of Candidate GMPEs for DCPP 23 Section 5.5 de.scribed the selection of the candidate GMPEs for the median ground motion. The eight 24 candidate GMPEs selected for application to DCPP are listed below: 25

• Abrahamson et al. (2014), referred to as ASK14 26
• Akkar et al. (2014a, 2014b), referred to as ASB14 Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-1 Comment [CDAl]: 321 "Comment [CDA2]: 322 "Comment [CDA3): 391 , Comment [alex4): #323 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 27
• Boore et al. (2014), referred to as BSSA14 28
• Campbell and Bozorgnia (2014), referred to as CB14 29
• Chiou and Youngs (2014), referred to as CY14 30
• Idriss (2014), referred to as ld14 31
• Zhao et al. (2006), referred to as ZH06 32
• Tl Team implementation of Zhao and Lu (2011), referred to as Zlll (Section 5.5.1.1) 33 Based on the discussions in Section 5.5, the eight candidate GMPEs are all considered to be applicable to 34 35 36 OCPP for magnitudes 5.0-8.0, distances of 0-30 km, and periods of 0-3 sec for strike-slip and reverse earthquakes for sites on the footwall side with the following exceptions: the ld14 model is not considered applicable for distances less than 3 km for large magnitudes (M > 7.5) and the ASB14 model 37 is not considered applicable to magnitudes greater than 7.5. The technical justification for these 38 exceptions is given below. 39 For the ld14 model, there is a strong distance slope of the short-periods spectral values for large 40 magnitudes for distances less than S km. The other candidate GMPEs and two of the finite-fault 41 simulations (GP -Graves and Pitarka, 2015; and SDSU -Olsen and Takedatsu, 2015; see Section 5.2 and 42 Appendix J and references therein for more information) show saturation at short distances for short 43 periods. While the EXSIM method (Atkinson and Assatourians, 2015) in the SCEC validation of 44 broadband simulation methods also showed acceptable saturation with the limited data set, SWUS 45 scenario simulations indicate that it does not saturate as strongly as the other two simulation 46 approaches used nor as strongly as the GMPEs. The developer Gail Atkinson noted at the January 28-47 29, 2014 Special Working Meeting that, at distances less than 5 km, there may be additional 48 unmodeled saturation effects. Since Gail Atkinson has indicated at the January 28-29, 2014 special 49 working meeting, and also in subsequent email correspondence that the method does not saturate as 50 strongly as observations for distances less than 5 km, the Tl Team judges the EXSIM method to be 51 deemed less reliable in this distance range and therefore cannot be used as an argument for accepting 52 ld14 and very near distances. Lastly, EXSIM is not used in the Sammon's map approach to generate a 53 suite of common-form models. Instead, it is used for residuals (together with the other two validated 54 FFS simulations methods) in the weighting scheme. As a result, its behavior to short distance and high SS frequency does not impact the residuals too much. On the contrary, the ld14 model is used in the 56 generation of the base model via Sammon's map, so the Tl Team's assessment of the unreliable M-R 57 58 range has important downstream effects in the generation of reliable suite of the common-form models. 59 Figure 6.2.1-1 shows the median spectra for an M7.S strike-slip earthquake. At 5 km distance, all five 60 models are in a similar range in the short periods, but at 1 km, the Idriss (2014) model is outside the 61 range of the other candidate GMPEs due to the stronger distance scaling in this short distance range. Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-2 Comment [CDAS): 325 "Comment [CDA6): 326 Comment [CDA7]: "Comment [CDAS): 327 ,. . Comment [CDA!>): 1038 , Comment [alexlO): #328 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 62 There is very little empirical data to constrain the short-distance large-magnitude scaling. For M 7.2, 63 R<JP 5 10 km, Rx < 0 km (excludes HW sites), Vs30 > 450 m/s (subset of Vs30 used by ld14), and requiring 64 more than one recording from an earthquake to constrain the distance scaling, the NGA-West2 data set 65 contains only 19 recordings, all of which are from the Chi-Chi earthquake. If the V530 range is expanded 66 to include soil sites (as used by the other four NGA-West2 modelers), then the short distance, large 67 magnitude data set on the footwall (FW) increases to 35 recordings of which 30 are from Chi-Chi, 3 are 68 from Kocaeli, and 2 are from Landers. While the short-distance scaling in the ld14 model at M6.6 is 69 slightly steeper than any other candidate GMPE models (Figure 6.2.1-1 lower panel), it is still in the 70 overall range of the other models and the finite-fault simulations; however, at large magnitudes (M7.5, 71 shown in Figure 6.2.1-1 upper panel), the short-distance slope is even steeper than M6.6 and does not 72 show saturation. Because the short-distance scaling in the ld14 model leads to a model that is an outlier 73 from the other GMPEs and from the finite-fault simulations, and furthermore, because the ld14 short-74 distance large-magnitude scaling is based on a more limited data set due to the narrower range of V530 75 values used by Idriss, the Tl Team judged that the ld14 model is not reliable in the short distance range 76 (53 km) for larger magnitudes (M 7.5). 77 For the ASB14 GMPE model, the scaling above M7.5 is not well constrained by the empirical data used 78 to derive the model: the only earthquake above M7.5 in the ASB14 data is the M7.51 Kocaeli 79 earthquake (magnitude from the PEER NGA-West2 database). Because the M > 7.5 scaling in the ASB14 80 model is based on only one earthquake and this earthquake is part of the larger NGA-West2 data set, 81 the ASB14 model does not add information on the large magnitude scaling. Therefore, the Tl Team 82 judged that the ASB14 model should not be applied for magnitudes greater than 7.5. 83 84 85 86 Although previous hazard sensitivity studies (Section 4.1.4) showed that sources at large distances (30-300 km) do not contribute significantly to the hazard at DCPP for hazard levels less than 10*3 {the deaggregation for 1 Hz shown in Figure 4.1-4b indicated that there is no contribution to the hazard for distances greater than 50 km), the GMPEs still need to scale in a reasonable way to the large distance 87 for all sources. As long as the large-distance scaling is not unreasonable, then the GMPEs can be used 88 for the distant sources. A comparison of the distance scaling for 0.5 Hz is shown in Figure 6.2.1-2: the 89 ASB14 GMPE model has the weakest attenuation with distance but there is still not a significant effect 90 on the hazard. Figure 6.2.1-2 also shows that the predicted median by ZH06 and Zlll are much higher 91 than the predicted median by ld14 at short distance. In general, the predicted median by ZH06 and Zlll 92 are higher than the other GMPEs over a wide distance range, whereas the ld14 model is much higher 93 only at short distance range. The Tl Team judged that the overall higher level of ground motion in the 94 ZH06 and Zlll represented credible alternative scaling models that should be included. As mentioned 95 above, because the ld14 model is based on a much smaller number of near-fault data {due to restricting 96 the data to Vslo > 450 m/s), there is much less constraint on the short-distance scaling. The Tl Team 97 judged that the short-distance scaling for large magnitudes is not as well constrained in the ld14 model 98 as it is in the other NGA-West2 GMPEs which had the advantage of using the much larger data set that Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-3 Comment [CDA11]: #329 " Comment [CDA12): 330 Comment [CDA13): 331 r "Comment [CDA14): 332 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 99 included soil data at short distances. 100 The Tl Team judged that the large distance scaling in the candidate GMPEs is reasonable for application 101 to DCPP because there is no significant contribution (less than 3% contribution as shown in Figure 4.1-3 102 for 1 Hz} to the hazard for hazard levels less than 10*3 for any of the GMPEs. 103 6.2.2 Evaluation of Candidate GMPEs for PVNGS for Greater Arizona Sources 104 Section 5.5 described the selection of the candidate GMPEs for the median ground motion. The six 105 candidate GMPEs selected for application to PVNGS for Greater Arizona sources are listed below: 106 107 108
• Abrahamson et al. (2014), referred to as ASK14
• Akkar et al. (2014a, 2014b), referred to as ASB14
• Bindi et al. (2014a, 2014b), referred to as Bi14 109
• Boore et al. (2014), referred to as BSSA14 110
• Campbell and Bozorgnia (2014), referred to as CB14 111
• Chiou and Youngs (2014), referred to as CY14 112 Based on the data sets used to derive the models, the Tl Team judged that the six candidate GMPEs are 113 applicable to normal and strike-slip earthquakes with magnitudes 5 to 7.5 at distances of 0 to 200 km 114 with the exception that the Bi14 model is not considered to be applicable to magnitude greater than 7.0 115 based on the strong change in the magnitude scaling for S Hz. The magnitude scaling of the candidate 116 GMPEs for 5 Hz for strike-slip earthquakes at an Rx distance of 5 km is shown in Figure 6.2.2-1. As 117 evident from the Figure 6.2.2-1, the Bi14 model shows an increase in the magnitude scaling above M7, 118 whereas the other candidate GMPEs for DCPP show magnitude saturation. Based on this trend, the Tl 119 Team judged that the Bi14 model is not applicable for M > 7 for 5 Hz. This feature of the Bi14 model is 120 not seen for all spectral frequencies, but for simplicity of application, the Tl Team decided not to use the 121 Bi14 model for M > 7 for all spectral frequencies. 122 6.2.3 Evaluation of Candidate GMPEs for PVNGS for Distant California and Mexico 123 124 125 126 Sources Previous hazard sensitivity studies (Section 4.2.3) showed that distant California and Mexico earthquakes could have a significant contribution to the low frequency hazard at PVNGS. The relevant sources are mainly large magnitude (M7 to M8.5) strike-slip earthquakes. The issue of the 127 application of the GMPEs to these sources is the large-distance attenuation from California to central 128 Arizona, and, in particular, whether the attenuation from California to central Arizona is different from 129 the attenuation within California. Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-4 Comment [CDA15]: , Comment [CDA16): B3 , Comment [alex17): , Comment [alex18): 034 Comment [CDA19): 335 .. Comment [CDA20]: ns Comment [alex21]: 041 Comment [CDA22): 336 , Comment [alex23): , Comment [CDA24]: n1 Comment [CDA25): 338 0.1 1 1575 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 Distance Scaling (M7.5 SS, PGA) ..... __ .... _______ _ o.: -AS*:l4 ---A.$814 ce:4 ('j -Zlll -1)!4 Rupture Distan<e I krnl Distance Scaling (M6.6 SS, PGA) -B>SA14 CB14 (y 14 -*L: land -1)14 Mioain F S 1mLI a ti -Rupture D*st;once lkm I 10 10 1576 Figure 6.2.1-1: Distance scaling of the 5%-damped response spectra (PSA) at PGA for the candidate 1577 GMPEs for a M7.S strike-slip event (top panel) and MG.6 strike-slip event (bottom panel). The mean of 1578 the finite fault (FF) simulations available for M6.6 is also shown in the bottom panel. The Zlll and ZH06 1579 PSA are identical at M6.6. Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-58 1S80 v ... .. N II I-@J B cf "' Q, 1581 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 Distance Scaling (M7 SS, 0.5 Hz) 1 0.01 --ASK14 --BSSA14 CB14 CY14 0.001 --ld14 A5B14 --ZH06 and Zll 1 Bi14 0.0001 1 10 100 R*u* Distance (km) 1582 Figure 6.2.1-2: Distance scaling of the candidate GMPEs at 0.5 Hz for a M7.0 strike-slip event. The Zll 1 1583 and ZH06 PSA are identical at M7.0. 1584 1585 Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-59 1586 T=0.2 1.00 SS 0.70 _..., C> .......... <( 0.50 (/) CL 0.30 0.20 Rx=5 5.0 5.5 6.0 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 .... ;** *_, .. 6.5 M .,-* ... ,,-** .::*-.-:: :: ... _:::..:.-7.0 *ASK14 *ASB14 *Bi14 1 BSSA14 oCB14 CY14 7.5 8.0 1587 Figure 6.2.2-1 Magnitude scaling of the candidate GMPEs at 5.0 Hz for strike-slip event with Rx distance 1588 5 km. 1589 Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-60 Comment Number 1040 -Consistency of Key Equations: Chapter 6, Lines 409,410 PPRP Comment: The parameters FREv and FNML defined on these lines do not appear in Eq (6.4-1 ). On the other hand, F in Eq 6.4-1 is not defined. Furthermore, this equation differs from what would seem to be intended to be its equivalent in Appendix C, Part II, Line 33, where FREv and FNML appear, but not F, and an additional coefficient a10 appears that is absent in 6.4-1. Also, coefficient a9 is squared in 6.4-1, but not in the Appendix C counterpart. It would be beneficial and less confusing to many readers if the same terminology for predictor variables used in the West1 and NGA-West2 projects were used throughout the report. For example, please consider replacing "FREv" and "FNML" with "FRv" and "FNM" (and note, as mentioned above, that these terms are not actually used in Eqs (6.4-1) and (6.4-2) and instead only a single "F" indicator variable is used in these equations). Please replace "F" in these equations with the mechanism-specific predictor variables or modify the text accordingly, and in any case make changes to ensure consistency with Appendix C. It is likely that the inclusion of a tenth coefficient in the text that follows refers to the inclusion of two predictor variables to represent the style-of-faulting. If this is the case, and the equations are corrected, then please ignore those comments that refer to the missing tenth coefficient elsewhere in the list of comments. Tl TEAM -PM Reply: The PPRP is correct. The two formulas were corrected to insert the missing style-of-faulting factors and coefficients. Corrections applied to Chapter 6 and Appendix C -Part 11 No change was applied to the FREv and FNML notation to be consistent with the notation used throughout the report and in the HID Excerpt of Chapter 6, Section 6.4. 1 and Appendix C -Part II follows in the following pages.

Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 427 based on the comparisons with hazard relevant data sets (empirical and/or simulated) and with the 428 density of the suite of representative models within each cell, to represent the center, body and range 429 of median predictions. The representative model for each cell is defined as the model leading to a 430 hazard curve that is the closest to the mean of the hazard curves from all the models within a given cell. 431 In particular, the model is selected by minimizing the variance of the difference in the log hazard for the 432 model and the log of the mean hazard for the cell measured over a range of ground motion levels. The 433 mean hazard is used because the primary use of the SWUS GMC models will be to develop mean hazard 434 curves for the NPP sites. 435 The use of the visualization technique for the sampling of the suite of common-form models is applied 436 to the DCPP sources and to the Greater Arizona sources for PVNGS. The ground-motion models 437 addressing the ground motion for PVNGS from sources located in central and southern California and 438 Mexico is treated with a different approach based on as-published GMPEs with path-specific adjustment 439 factor to take advantage of the available ground motion data in Arizona from these sources (see Section 440 6.2.3 for details on the approach, and Section 9.2 for the technical justification). 441 6.4.1 Fitting Candidate GMPEs to a Common Functional Form 442 In the first step, the candidate GMPEs are fit to a common functional form, which allows an evaluation 443 of the distributions of the coefficients. This step is necessary because the GMPEs use different functional 444 forms and the coefficients cannot be directly compared between GMPEs. By using the common form, 445 the mean and covariance of the resulting sets of coefficients can be estimated. This gives a distribution 446 of the set of coefficients, which can be sampled to generate a large suite of new common-form models. 447 These new models lead to a continuous distribution of median models which fill in between the 448 candidate GMPEs as well as broadening the range of models beyond the range of candidate GMPEs. 449 Based on the evaluation of these new common.form models, which is done by comparing them to data 450 and simulations. a subset of common-form models is selected and weighted appropriately to capture 451 the center, body and range of median PSA predictions. 452 Two functional forms were used for the common-form models: one based on rupture distance (called 453 Model A) and one based on Joyner-Boore distance (called Model B). The common form for Model A is 454 given in Equation 6.4-1 and was selected based on the magnitude, distance, depth, and style-of-faulting 455 dependence in the candidate GMPEs. Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-14 , Comment [CDA81]: 403 >Comment [CDA82]: 365 Comment [CDA83): 367 "Comment [CDA84): 366 Comment [CDA8S]: 367 Comment [CDA86]: 367 Comment [CDA87]: 367 Comment [CDA88): 367 Comment [CDA89): 368 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 L11(SA11,s1:<M .R1/(1,,Zm1<*F. T)) = t{)(T)-exp(B, (T))R11t:f' + exp(B, (T))Z70" + exp(8rn(T))F,11w 456 +( 04(T)+ + 06(T)2 )-cxp(0.>(T))t:v,1n + 16\(T)(S.5-6.5) + 82(T)(M -5.5) }hr M < 5.5 Ol(T)(M -6.5) .for5.5 M 6.5 0;( T)( M -6.S) for M > 6.5 457 (Eq. 6.4-1) 458 459 where SAllAsF refers to the model without HW effects (called the base model), M is moment magnitude, 460 RRuP is rupture distance in km, Zro* is the depth to the top of rupture in km. F*ev is a flag for the reverse 461 (REV) style-of-faulting (i.e. F*ev = 1 for REV sources, and is zero otherwise), and FNML is a flag for the 462 normal {NML) style-of-faulting (i.e. F * .,L = 1 for NML sources, and is zero otherwise). The coefficients for 463 the linear distance, style of faulting, and rupture depth in the common-form model ( 87, 8.) and 8,., J 464 are fit using the exp( O{) (fork = 7. 8, 9, I 0) to ensure that the terms are positive for all four 46S coefficients. A similar form is used for Model B, but with R,J* replaced by R1". There is no site term (e.g. 466 in the common form because the application is for a single reference site condition with 467 = 760 m/s. 468 To focus the common form on the most important sources, the fitting of the common form used 469 different faulting styles for the two sites: for DCPP, the common form is derived for strike-slip (SS) and 470 REV earthquakes only and a single NML factor is added at the end; for PVNGS, the common form is 471 derived for SS and NML earthquakes only and a single REV factor is added at the end. For adding the 472 style-of-faulting (SOFJ factors at the end, smoothed average NML factors for DCPP are computed based 473 on the mean style-of-faulting factor for NML earthquakes in the eight candidate GMPEs for M6.5, z10* = 474 0 km, Rx = -30 km. Because the NML faulting events do not contribute significantly to the haz.ard at 475 DCPP (as discussed in Section 4.1), only a single scenario was used to evaluate the NML style-of-faulting 476 factor. For PVNGS, the same approach is used to compute the average REV style*of-faulting factor based 477 on the six candidate GMPEs. Similar to DCPP, only a single scenario was used to evaluate the REV style of 478 faulting factor because the REV faulting events do not contribute significantly to the hazard at PVNGS (as 479 discussed in Section 4.2.2). 480 For the regression, the exp( Bk) terms (fork = 7, 8, 9, t 0) are replaced by a;. Thus, the following 481 function is used for the prediction of PSA values using the sampled functions (Eq. 6.4-2): Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-15 .. " Comment [CDA!>O]: 364 Comment [CDA!>l]: 369 Comment [CDA!>2]: 3n Comment [CDA!>3): 1040 Comment [CDA!>4): 370 Comment [CDA!>S): #371 Comment [CDA!>6): 37S Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 l11(SA11,s1(i\4 ,R,11:"'Z11111, F, T)) = a11(T)-a;(T)R,11:" + 482 +(a4(T)+a5(T)(,o\rl + f-a1(T)(5.5-6.5)+a2(T)(,o\.1-5.5) forM <5.5 l a,(T)(M-6.5) jilr5.5::S,M::S,6.5 a)(T)(M-6.5) fc>rM>6.5 483 (Eq. 6.4-2) 484 where ak = B, for k = 0, 1.. .. 6 and ak Ok fork= 7,8, 9, IO. Using the square of the aA terms 485 fork= 7, 8, 9 and 10 ensures a positive value for these parameters. 486 To evaluate the suitability of the common form in Eq. 6.4-2 to fit the candidate GMPEs, the Tl Team 487 inspected the comparisons of the scaling in the original candidate GMPEs with the scaling in the fitted 488 common-form models. Examples comparing the distance scaling of the candidate GMPEs for DCPP and 489 PVNGS with the fitted common form models for PGA and T = 1.0 sec are shown in Figures 6.4.1*1 to 490 6.4.1-3 for the DCPP, PVNGS (Model A) and PVNGS (Model B), respectively. Based on inspections of the 491 fits, the Tl Team judged that the function in Eq. 6.4-2 is flexible enough to capture the full range of 492 scaling in the selected candidate GMPEs. 493 The Zro< term is included for the R,J,-based common-form models, but not for the R18*based common* 494 form models, because the candidate GMPEs which use Rm as their primary distance metric (ASB14, 495 BSSA14, Bil4) do not include Zm* depth-scaling. Therefore, for the common-form models. 496 a,= 0. For the R10-based common-form models fit to the candidate GMPEs with z,0* effects (e.g. 497 ASK14, CB14 and CY14), the Zro* scaling is not maintained. This is a feature of the Rie metric which does 498 not include depth effects. For the R*up*based common-form models, the candidate GMPEs are evaluated 499 at three z10* values per magnitude, centered on the mean z,0* from the Z,0.-M relationship developed 500 by CY14. The high and low values are +/- 3 km from the mean Zro*-M relationship of CY14, with the 501 constraint that Zro* is greater or equal to 0 km. 502 6.4.l.l DCPP Fitted Models 503 For each of the eight selected candidate GMPEs for DCPP listed in Section 6.2.1, median predictions (in 504 In units) are calculated for MS to MS, Rx-= -2 to -200 km, V530-= 760m/s, and strike-slip and reverse 505 faulting mechanisms are included. The magnitudes and distances used to define the scenarios for fitting 506 the candidate GMPEs for DCPP are listed below: 507

• M:: 5.0, 5.2, 5.4, 5.5, 5.6, 5.8, 6.0, 6.2, 6.4, 6.5, 6.6, 6.8, 7.0, 7.2, 7.4, 7.5, 7.6, 7.8, 8.0 Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-16 ,. Comment [CDA97): 374 Comment (CDA!IS): 375 and 376 Comment (CDA99): 1040 .. Comment [CDAtOOJ: 732 Comment (CDAlOl): 377 Comment (CDA102): 378 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT -Draft Rev. 1 27 GMPE 0.2 ASK14 0.2 BSSA14 0.2 CB14 0.2 CY14 0.2 1014 28 29 Figure 1-2: Logic Tree for Median at DCPP 30 Additional Epistemic Uncertainty 1.6 sigmaMu (M=8) 0 -1.6 sigmaMu (M=8) 31 2.2 Common Functional Form for Base Model 32 The functional form of the DCPP base model GMPEs is given in Eq. 2-1: Ln ( SAHr.w*(A1, RIWI" zlOR' F, T)) = ao(T)-a;(T)RIWI' + a;(T)ZroR + 33 +( a4(T) + a5(T)(M -5) )ln( + + forM<5.5 I a1(T)(M-6.5) for5.5sMs6.5 . a3(T)(M-6.5) forM>6.5 34 (Eq. 2-1) 35 The coefficients for 17 spectral periods and up to 31 models are listed in excel files named 36 "Coefficients_Weights_DCPP _TX.csv", where Xis the period, which are collected under the folder 37 "DCPP _Coefficients_Weights-11262014", which is provided as an electronic attachment to the HID. 38 The list of the included excels files and their contents are described in section 4. There may be less Appendix C: Final SWUS GMC Models Hazard Input Documents (HIDs) Part II: DCPP, Rev.1 Page C Part II -3 TIER 2 COMMENTS Comment Location in Text PPRP Comment Summary of Revisions to Report Number Tier 2 Comments (by chapter) General 1033. NIA Please carefully review the references for completeness and to ensure that all cited references are listed. For example, some of the same references in different chapters are listed slightly differently (i.e., one might be missing a volume number or page numbers while another miaht not). 1034. NIA The report is written primarily in third person, which implies that the An author list is now included in the TOC (third page). writers of the report, chapter, and/or section performed the work or made the decisions and assumptions that are being described. However. there A comprehensive check will be made to ensure that the are no specific authors listed on the report, which is only identified by the personnel performing the evaluations or assessments are clearly publisher, GeoPentech, and a list of participants in the project Please defined. make it clear who the writers of the report are either on the Title Page (ideally) or in the introduction so that there is clear ownership of the work that is being described in the third person. When the description refers to someone else's work, decision. or assumptions, please make it clear that this is the case. There are also still sporadic uses of the pronouns *'we" and "us" throughout the report, which is even more ambiguous. Please consider replacing these pronouns with the person or group that the pronoun refers to (e.g., the Tl Team or a specific Resource Expert) or change the sentence to third person to refer to the identified writers of the reoort. CHAPTER 0-Table of Contents 1035. NIA The Section No. 5.2.1.1 appears twice. The second one should be fixed 5.2.2.1. 1036. NIA In the title of Section No. 5.5.3, Vs should be Vs30. fixed 1037. NIA The Section No. 6.4.5.3 appears twice. The first occurrence should be fixed 6.4.5.2. CHAPTER 1-Introduction 1038. Lines 57-58 The description of Vs3c as "shear-wave velocity" should be more done in both locations accurately described as "travel-time-averaged shear-wave velocity." This change also applies to the definition of Vs3n in the list of terms and acronvms. 1039. Line 63 Please define "kappa," since this is the first time that this term is used in done in both locations the report. Please also add the definition of kappa to the list of terms and acronyms, which only contains the specific symbols used to characterize the different ways kappa can be estimaled and no definition of the generic term kappa itself. 1040. Line 80 Please define "sigma," since this is the firsl time that lhis term is used in Term sigma is now introduced in Section 1 . 1. and defined in the report. Please also add the definition of sigma to lhe list of terms and abbreviation list acronyms, which only contains the specific symbols used lo characterize the different tvoes of standard deviations and no definition of the aeneric term sigma itself. 1041. Line 109 Please consider replacing the phrase '"suites of models'* with done "representative suite of models** here and elsewhere in the report to conform with terminology used in "Atkinson, G.M., Bommer, J.J., and Abrahamson, N.A. (2014). Alternative approaches to modeling epistemic uncertainty in ground motions in probabilistic seismic-hazard analysis, Seismo/oaical Research Letters, Vol. 86, DD. 1141-1144." CHAPTER 2-Project Organization 1042. Line 52 The description of the workshops is incomplete and does not list all of Sentence modifies to add the qualifier "among other purposes. the purposes of the workshops. Please qualify the sentence to indicate the Workshops ..... ** that this is only one of the purposes of the workshops or expand it to list all of the purposes. 1043. Line 53 Since this is the first time that peer review is mentioned in the report, PPRP is already introduced in Section 2.1.2, and is already please introduce the peer review panel and the acronym PPRP. Please included in the list of acronyms also add the definition of PPRP to the list of terms and acronyms. 1044. Line 75 The use of the phrase "Appendix A of Appendix A" is awkward. Please Done in Chapter 2, pending in Appendix A consider calling the appendix of an appendix something different in order to avoid confusion (e.g., "'annex"). 1045. Line 81 Please correct the name of the power plant, i.e., "Saint Onofre" should aone be San Onofre " 1046. Line 146 Please correct the grammar in 1his passage, e.g., "preliminary estimate of the kappa sensitivity ... " 1047. Line 157 The large magnitude earthquakes in California cited here appear lo be "and Mexico" added the same events referred to elsewhere in the report as large earthquakes in California and Mexico (appropriately, since the 2010 El Mayor-Cucapah event is included). Please clarify or correct for consistency. 1048. Line 162 Please provide a reference to the PEER report that is mentioned in this Section mildly rearranged to provide the requested citation sentence. (Kishida et al.. 2014) 1049. Lines 167-171 Please provide references for the PEER projects that are referred to in NGA-Subduction effort is not referred to this paragraph. 1050. Line 187 Please reference the report or appendix where the PE&A study can be found. 1051. Line 189 Please consider replacing the word sensibly" with one that better Changed to "significantly" conveys what the writer intended to mean. 1052. Line 253 Please explain what anticipated" means in this context. Changed to "preceded" CHAPTER 3-SWUS GMC Work Plan and Key Study Tasks 1053. Line 97 Please confirm that the distance range "30-100 km" is correct and should Changed to "less than 100 km" not be "less than 100 km." 1054. Line 152 In Table 34-1. "Ken Campbell Consulting" should be "Kenneth W fixed Campbell Consulting." 1055. Line 244 Please clarify that "the second meeting" refers to the January 2014 Clarification added Special Working Meeting. 1056. Line 340 In Table 3 7-1. "Ken Campbell Consulting" should be "Kenneth W fixed Campbell Consulting." CHAPTER 4-Seismotectonic Setting 1057. Line 160 Please explain the difference between "layered faults" and "individual Definition of "layered fault" added to text faults." 1058. Lines 163-164 These lines refer to two categories, namely "the California and Mexico Entries in the table are now aligned with the text in the chapter faults (referred to as Regions 1 and 2&3 in this Report)," and "other faults (AZ,NM, NV, and Mexico)." Table 4.2-2 has rows for "CA Faults" and "AZ, NV, & Mex Faults." Do the rows of the table correspond to the two categories of faults described in the text? If so, please align the terminoloov; if not, olease clarifv 1059. Lines 172-179 The legends of Figures 4-8a and 4-Sb are not well correlated with the Clarifying text is provided in the chapter body. Also. a new set of text. For example. "NSHMP faults" are noted in the legends but are figures showing the contribution from individual faults has been defined neither there nor in the text. And the text calls attention to the added: this supports the conclusions on the distant sources dominance of distant fault sources for low frequency at 10*4 AFE, but the being the main contributors at low frequency figures do not identify the curves associated with "distant fault sources." Please reconcile the fiaure leaends and the text. 1060. Line 289 In Figure 4-8a. please explain the meaning of "coarse" and "fine" areal The meaning has been introduced in Section 4.2.3 and is not sources. repeated in the figure caption 1061. Line 293 In Figure 4-8b, please explain the meaning of "coarse" and "fine" areal The meaning has been introduced in Section 4.2.3 and is not sources. repeated in the figure caption 1062. Tables 4.1-4, 4.2-1, Please identify the pertinent site (Le., DCPP or PVNGS) in the title of done 4.2-2 each of these tables. 1063. Figure 4-1 The two line colors for the SAF are not well distinguished in the figure. done Please consider making improvements lo remedy this. 1064. Figure 4-2 Please identify the site (DCPP) in the figure caption. done 1065. Figure 4-6 The arrow for the Cerro Prieto fault points to the Imperial fault (CPF is done the next bold red line to the SW). Please correct this. CHAPTER 5-Ground Motion Databases and Candidate Models 1066. General Two references for Kishida et al.. 2014a and 2014b. appear in the Fixed. Now the two separate references are appointed as 2014a reference list. However. many of the citations in this chapter refer only to and 2014b Kishida et al. (2014) without distinguishing 2014a from 2014b. Please check and correct this omission. 1067. General The figure numbering scheme seems lo be inconsistent in this chapter. Done. Now the figure and table numbers renect the two section For example, Figure 5.2.2-2 is called in Section 5.2.2.1, indicating the level convention that only the chapter number and first two section levels prefix the sequence number. But a Figure 5.2.3.4-1 is called in Section 5 2 3 4. so in that case the chapter number and all three section levels prefix the sequence number. There are some other anomalies as well. Please check carefully and ensure that numbering is done consistently throuahout. 1068. Line 11 Use of the term "proponent models" is confusing, especially given that Word "proponent" removed the report is written in third person with no identified authors. The term is usually reserved for describing a model or method proposed by a Proponent Expert (PE). If this is not the meaning of the term in this context or in similar contexts elsewhere in the report, please consider using another term to describe the models or identify who the proponents are (e.g .. "Tl Team proponent models") when the term is used. 1069. Line 27 The intended meaning of the sentence is ambiguous. If the intent is to done say that the Wells earthquake was in the southern Basin and Range, please review for accuracy (e.g., was it in the northern or southern Basin and Range?). If the intent is that the Wells earthquake provides control for a normal faultina earthauake, if one should occur in the Southern Basin and Range. please clarify and correct, as needed. 1070. Line 31 Since this is the first time that the term "PSA" is used in the report, done please define it. 1071. Line 47 Please add that the bottom frames also show the number of recordings Verbiage added to address that the frame addressed the per site class. number of recordings per site conditions (VS30) 1072. Line 85 There is no evidence in Figure 5.1.2-1 of "Station Z14A, shown by the Sentence restructured and reference to star removed (it was old open star". Please clarify. text associated to a previous version of the figure) 1073. Line 87 Please complete the citation of "Kishida (i.e .* Kishida et al. 2014a or done 2014b?). 1074. Line 158 Please correct the figure number on this line. which should be Figure done 5.1.5-1. 1075. Lines 173-174 The spelling of the fault names differs between the text and Figure 5.1.5-done 2 ("ltozawa" in the figure becomes "ldozawa" in the text, and "Yunodake" in the figure becomes "Yunotake" in the text). Please edit for consistencv. 1076. Lines 175-176 The total moment given here and attributed to personal communication is inconsistent with the moment magnitude of 6.7 given for this event on Line 164 (the sum of the moments on Line 175 imply M 6.56). Please resolve the inconsistency. In doing so, please consider whether it would be appropriate to cite published moment estimates (e.g., Tanaka et al., 2014, report a moment consistent with M 6.7 and approximately equally partitioned between the two faults) instead of those reported from oersonal communication. 1077. Line 202 Please supply the missing Table 5. 1. 7-1. The correct citation is the table 5. 1.2-2 1078. Line 209 The symbols referring to the different types of kappa used in this sentence are slightly different from those listed in the terms and acronyms. Please use a consistent set of symbols for kappa throughout the report and appendices. 1079. Line 216 K,, is undefined at this point in the text. Please correct this. 1080. Line 223 Please consider whether a more appropriate characterization than "upper bound can be used here (e.g .* is that categorical statement even consistent with the one standard deviation ranges cited for the other methods?). 1081. Line 228 Please include a reference to a publication describing the SCEC BBP Reference added (e.g., the paper by Maechling et al. in the Jan/Feb 2015 SRL may be aooropriate ). 1082. Line 242 Please consider citing the published paper by Dreger et al. (2015) in the done Jan/Feb 2015 SRL 1083. Lines 264-266 It is appropriate for the Tl Team to rely on the SCEC Validation Review done Panel for the technical analysis of the simulations. and to rely upon the judgment of that panel to determine which methods met the acceptance criteria established in that review. However, 1he Tl T earn itself needs to justify that meeting those acceptance criteria makes the methods suitable for the specific purposes for which the simulations are to be employed. Those purposes are stated on Lines 227-233. Please augment the summary statement on Lines 264-266 by explaining how meeting the SCEC review panel's acceptance criteria makes the simulation methods suitable for addressing the problems laid out on Lines 8-14.

1084. Lines 306-315 This passage needs rewriting because: (1) the BSL model is not done identified as GIL7 on Line 309, but seems to be the same as what is called GIL7 in the legend of Figure 5.2.2-1 and then on Line 312; and (2) the passage is repetitive (e.g., the verbiage about routine estimation of moment tensors on Line 309 is repeated on Line 314-315; the basis of the GIL? model in broadband waveform modeling is slated repetitively on Line 308 and then on Line 314). 1085. Line 322 "Frequency wave-number" is written differently on this line than it was on done Lines 304 and 3 t 1 ("frequency-wave number"). Please review the hyphenation convention and apply one consistently (note also that both "wave number" and "wavenumber" are in common use, so the easier-to-read form "freauencv-wavenumber" is also an ootionl. 1086. Line 361, 364 "Area" is used to signify rupture area in Equation 5.2.3-1, but "A" is done defined as rupture area on Line 364. Please edit for consistency. 1087. Lines 37 4-375 Please indicate whether this statement is an assumption or is based on an evaluation of data, models, etc., by the Tl Team. Under internal revision 1088. Line 383 Please correct the figure number. It is called out as Figure 5.3.2.1-1 on done this line, but the figure itself is labeled as Figure 5.2.3.1-1. Moreover. the numbering scheme used elsewhere in the report appears to call it Figure 5 2 3-t. since it occurs in a subsection of Section 5.2 3 (e.g .. by analogy with the fact that Figures 5.2.2-1 and 5.2.2-2 occur in Section 5.2.2. t). 1089. Line 392 The figure number 5.2.3.2-1 is inconsistent with the fact that it is the ok second figure in the subsection. Please check the figure numbering convention and make ii consistent with the rest of the chapter and reoort. 1090. Line 396 Please indicate that CB14 also used the functional form of the hanging-wall term developed by Donahue and Abrahamson (2014). 1091. Line 411 Please consider replacing "we" (first person) with third-person to be done consistent with the remainder of the report. 1092. Lines 427. 431. and The figure citations do not correspond to the figure numbering. Please 433 check the figure numbering against the figure citations and correct as needed. 1093. Line 452, 458 The table called Table 5.1.1-2 on this line appears to be the table corrected labeled Table 5.1-2 (and called by those numbers elsewhere in the reoortl. Please correct here and in subseauent occurrences. 1094. Line 464, 475, 481 Line 464 gives the distance criterion for NGA-W2_DC-MED as abs(Rx)<70km. whereas the lines 475 and 481 give it as R<70 km, which is more restrictive. Please clarify how the various distance metrics are used together to screen records for NGA-W2 DC-MED. 1095. Line 492 Please quantify what "similar enough" means in regards to the value of Vs3-0 (e.g., in terms of the percent difference in site-amplification factors). 1096. Line 506 Previously, Akkar et al. (2014c) was cited as the database reference. Clarification added -it is a subset of the dataset used to derive Please check whether the citation given on this line is correct in the the ASB14 model, which in tum is a subset of the RESORCE present context. database (Akkar et al 2014 cl 1097. Lines 508 and 517 The criterion abs(Rx)<70 km leaves the total distance unconstrained. Please provide a complete statement of the distance selection criterion. 1098. Line 548 Please consider whether this might be a good place to introduce the done symbol 41> ** , so that it will be defined prior to its use on Line 553. 1099. Line 558 "Disaggregation" is used on this line, whereas "deaggregation" is used done elsewhere in the report. Please edit for consistency. 1100. Lines 565-572 The selection criteria (distance, magnitude, number of recordings per Sentence added event and site) do not seem to be given. Please check and correct if necessarv. 1101. Line 566 "NGA-W2" is "NGA-West2" elsewhere. Please edit for consistency. We found one case saying "-west2 which has been corrected to "-West2" 1102. Line 579 Please check whether "for use in" should be "is used in". As is, the Changed to "to be used in" sentence lacks a verb. 1103. Line 585 Please add the missing parenthesis closure. ok 1104. Lines 592-593 Please indicate whether the 3 events per station requirement was also applied. 1105. Line 601 Section 5.4.1 does not contain the discussion of the Idriss 2014 model Section 5.4.1 has now a small sentence on how Idriss (2014) that is referenced here ("As noted in Section 5.4.1"), nor does there treats the residuals appear to be any prior reference to the Idriss model in the chapter. Please make the necessary corrections. 1106. Line 610 Please replace "200-30 km" with "30-200 km." done 1107. Lines 614-615 CB 14 used mixed-effects regression to derive the anelastic attenuation tenn from data with RR11P > 80 km, but allowed the source terms to vary from those for RRuP < 80 km. Although this does not necessarily impact the decision not to use CB14, the descrip1ion of what CB14 did should be correctly stated in the text. 1108. Line 619 Please indicate what range that "1his magnitude-distance range" refers to. 1109. Lines 619 and 626 Line 619 has the statement that 'the global dataset in this magnitude Second sentence has been removed because added confusion and distance range consists of 264-415 recordings from 4 to 23 without additional information earthquakes." Line 625 states "Within this magnitude and distance range, the global dataset contains four earthquakes and 280 records. Please clarify why these statements are not contradictory. 1110. Line 627 The cited figures do not exist Please add them. Figures are there 1111. Line 669-670 Please correct the figure references (they shou Id be to Figures 5 5 1-1 done and 5.5.1-2). 1112. Line 673 Please correct the figure reference (it should be to Figure 5 51-3). done 1113. Line 683 Please correct the table reference (the intended reference appears to be done to Table 5 51-1). 1114. Line 724 Please clarify why specific scenarios had to be specified. given that kappa is not being explicitly modeled as a source effect. 1115. Line 725 Please explain why only footwall scenarios were used. 1116. Line 727 Please consider rewording the reference to "Q attenuation." to avoid the implication that 1he kappa effect is necessarily physically distinct from effects ordinarily parameterized in terms of a. Isn't the point that the kappa parameter (or at least Kc) is intended to capture attenuation effects that are so localized that in a practical sense they are better parameterized as site terms than as pa1h-dependent attenuation tenns, and that therefore isolation of kappa effects requires short-distance scenarios? 1117. Line 730 Please be more specific about which profile was used. Is ii one of those in Figure 2.6 of Kamai et al. (one is listed as having Vs30 of 750 m/s, none has exactly 760 m/s )? 1118. Line 735 Figure 5.5.3-1 appears to be labeled incorrectly. Please correct this. done 1119. Line 778 Rodriguez-Marek (2013) actually developed four single-station sigma Text expanded to clarify the confusion models: one with neither M nor R dependence, one each with Mand R dependencies, respectively, and a fourth with both M and R dependence. Please clarify which three have been chosen. and why. Note also that there is a perception of ambiguity introduced by mixing "dependent" and "independent" in listing the attributes of the selected models; i.e., is the "magnitude-independent" model alluded to also R independent (in which case it would be clearer to say "magnitude and distance independent), or is there a typo such that "magnitude-dependent" is what is actually intended? If one of the figures were not missing, this ambiguity would be cleared up, but it would be better to also do so in the text. 1120. Lines 779 and 781 Please check whether the first of the three models alluded to should be Text clarified to say that is magnitude-dependent "magnitude-dependent" (rather than magnitude-independent". which would appear to be inconsistent with the figures). Alternatively, if "magnitude-independent" is correct as written, please clarify whether it is paired with a distance dependence or not. 1121. Lines 780-782 Only the R-dependent and MR-dependent models are shown. and these done are in Figures 5.6.2-3 and 5.6.2-4, respectively (not 5.6.2-4 and 5.6.2-5 as called in the text). The other model (called "magnitude-independent" in the text) is not shown. nor is there any Figure 5.6-5. Please correct this 1122. Line 789 Please cite a reference for the assertions about the small-magnitude limitations of GMPEs at short distance. 1123. Line t122 Table 5.5.1-1 indicates that the Graizer (2014) GMPE was used for the DCPP GMC model. but the Graizer GMPE is not listed as being one of the models that was used in Chapter 6. Please either correct the table or the text in Chapter 6. If this GMPE was used, please justify its use in view of the fact that it is only published as a conference paper and has not been oeer reviewed or vetted bv the laraer scientific communitv. 1124. Figure 5.1.3-1 The caption cites Akkar et al. (2014a and 2014b), whereas the text (Line Clarification added 121) cites Akkar et al. (2014c), apparently in the same context. Please check whether this difference is intentional and make a correction if aooropriate. 1125. Figures 5.2.3.4-1 and These figures are mislabeled (as 5.2.3.3-1 and 5.2.3.3-2, respectively). Fixed 5.2.3.4-2 Please correct. 1126. Figures 5.3.2-1 and Please correct these figures. In each of these figures. the second row fixed 5.3.2-2 repeats the first with a scale change, and the remaining plots (recordings per site, recordings per event, etc.) are absent. 1127. Line 1258 In Figure 5.4.1-2, please explain why there is a triangular symbol plotted at slightly over 100 km or, if this is an error, please remove the symbol. 1128. Line 1263 In Figure 5.4.1-3, please explain why there is a triangular symbol plotted at slightly over 100 km or, if this is an error, please remove the symbol. 1129. Line 1322 In Figure 5.5.1-1, please define the meaning of the solid black symbols and the color and black trend lines. 1130. Line 1326 In Figure 5.5.1-2, please define the meaning of the solid black symbols and the color and black trend lines. 1131. Figure 5.5.3-1 Please correct the figure number. It is called Figure 5.5.3-1, but labeled fixed 5.5.3-2. 1132. Figure 5.6.2-2 Please improve the figure caption by including some basic contextual information. 1133. Figure 5.6.4-1 Please add the dataset identifiers given in Lines 805-808 of the text Names added to the captions (Blea, Blea2, and ABR) to the figure caption, or else delete them from the text, as the inconsistency is confusing. CHAPTER 6-GMC Models for the Median 1134. Lines 23-24 Table 5.5.1-1 indicates that the Graizer (2014) GMPE was used for the DCPP GMC model. resulting in the use of 9 models. The text indicates that 8 models, excluding the Graizer GMPE, were used. Please correct either the table or the text. 1135. Line 105 Please hyphenate "large-distance attenuation" to resolve the otherwise fixed ambiguous meaning. 1136. Lines 209-210 Not all of the simulations show that hanging-wall effects persist down to magnitudes of 5.5 and 6.0 for all fault geometries. This suggests that there is some uncertainty in whether such effects exist. Please discuss this apparent uncertainty and justify the decision to extend hanging-wall effects to smaller magnitudes. explaining whether this uncertainty is accounted for elsewhere. 1137. Lines 256-257 Please explain why, if hanging-wall effects are geometric, the cosine term is more appropriate than the arithmetic angle to model these effects. 1138. Line 269 The statement that the hanging-wall models are "equally likely" and "normally distributed" is still confusing on its face. However, the discussion that follows clarifies this apparent contradiction vis-a-vis the use of equal probability slices of the distribution. Perhaps, a statement like "as explained below" after introducing this apparent contradiction would provide less confusion for the reader. 1139. Line 303 Figure 6.3.2-5 shows CB14 having a step-like change in its HW factor as Sentence and figure replaced Rjb approaches zero along the strike direction. Please clarify how this is consistent with the claim that CB14 allows "a smoother transition" around the rupture compared with some other models. 1140. Lines 341-343 In reviewing all of the figures comparing the HW adjustment model with the simulations, all except Figure 6.3.2-14 compare the simulations only with the central HW model. In order to show that the five HW models adequately capture the uncertainty in the simulations, please show all five HW models in all of the figures and discuss any cases in which the five models to not appear to caoture the uncertaintv. 1141. Line 363 The term "scaled-backbone approach" is never used by Atkinson et al. Sentence rephrased: "Atkinson et al. (2014) introduced the (2014). These authors do mention the concept of selecting a single concept of selecting a single "central or backbone GMPE" and "central or backbone GMPE" and scaling it up and down. but do not scaling it up and down. This concept is here referred to as the specifically call this a scaled-backbone approach. Please consider "scaled-backbone approach", which provides a method to replacing the term "scaled-backbone approach" with a simple description develop a set of.. .. of the approach instead. 1142. Line 384 The term "generated models" is used in this sentence to refer to ground Done in section. Search ongoing in the rest of the report. motion models derived from the visualization (Sammon's mapping) technique. Terms such as "large suite of models" and "representative models" were used earlier in the section to refer to similar models. The concept of using visualization techniques to produce a distribution of models that sample the full model space is difficult enough to understand without being confused further by the use of different terms to describe the same technique or products thereof. In order to avoid such confusion, please consider using a consistent and strict set of terminology to refer to these models. For example, the term "candidate models" has been generally used to describe the GMPEs that are used in conjunction with the visualization method, since this term is used elsewhere in the report to describe such models; the term "suite of models" might be used to refer to the entire set of models that are generated using the visualization technique (e.g., the 2000 common-form models); and the term "representative suite of models" might be used to refer to the final set of models that are used in the GMC logic tree (e.g., the 25 or so common-form models). This latter term is also consistent with the general term used by Atkinson et al. (2014) to describe the method of generating models that sample the model space. whether it be by simple methods (i.e., scaling up and down) or by more complex models, such as those sampled from the Sammon's map. 1143. Line 402 It is possible that this is the first time that the term "Joyner-Boore Disagree. First occurrence of "Joyner-Boore distance (R,a)" is in distance is used in the report. If so, please note that this term refers to Section 6.3 the distance metric RJa. 1144. Lines 412-4t3 Please delete "010" and replace "(fork = 7.8.9. tO)" with "(fork = 7.8,9)" Fixed now (See general comment 1040) since there is no k = 10 coefficient in the model. 1145. Line 429 Please replace "(fork = 7,8,9, 10)" with "(for k = 7,8,9)" since there is no k Fixed now (See general comment 1040) = 10 coefficient in the model 1146. Line 433 Please replace "fork= 7.8.9. 10" with "fork= 7,8,9" since there is no k = Fixed now (See general comment 1040) 10 coefficient in the model. 1147. Line 444 Please replace "fork = 7.8.9 and 1 O" with "fork = 7.8 and 9" since there Fixed now (See general comment 1040) is no k = 10 coefficient in the model. 1148. Line 449 Please justify the selection of +/-3 km to represent the uncertainty around the mean value of ZroR-1149. Lines 463-464 In order for R.1a to equal IRxl. the footwall site must be located at a source-to-site azimuth of -90 degrees (ie., perpendicular to the fault within the bounds of the ends of the rupture). Please indicate that this is the case in order to justify the given distance equalities. 1150. Lines 472 and 493 The term "total residual" is usually reserved to mean the addition of the fixed between-event and within-event residuals in the aleatory variability model. Please consider calling this the "total fitted residual" or something like that to distinouish it from the true total residual. 1151. Lines 502-5t3 The entire discussion of using candidate GMPEs and interpolated A numerical evaluation was conducted to address this question versions of the GMPEs and the generation and simplification of the and will be included in the Rev.1 Report coefficient covariance matrices is confusing to a non-statistician. For example. what exactly are the sets of weights applied to and why can the covariance matrices be simplified in the manner discussed? Please consider expanding this discussion to better explain and justify exactly what was done. 1152. Lines 506-513 Please justify how it is mathematically possible with the addition of the See above interpolated GMPE ground motions to better capture the correlations? 1153. Line 524 Please be precise about what types of "standard deviations" are plotted in Figure 6.4.3-1. 1154. Lines 536-548 This explanation needs to be set out more clearly. The sentence beginning on Line 536 states that "for the DCPP application ... the central HW branch is applied to all common-form models." The rest of the passage. although rather difficult to read, appears to indicate the following: ( 1) HW effects are omitted from the 2000 models used for the Sammon's map, (2) the central HW model is appended to those footwall models, solely for the purpose of the simplified hazard calculations used in the selection of representative common-form (footwall) models from the original 2000, and (3) randomly selected HW models (from the equal-probability set developed in Section 6.3.2) are appended to the selected representative set of footwall models, to give the final set of common-form models for application to DCPP. If this is a correct interpretation, then the last item seems to contradict the sentence from Line 536 (and if this is not a correct interoretation, some clarification is needed). Please rewrite for clarity and consistency. This paragraph would be less confusing if a strict use of terminology to identify all of the different types of models were used, as suggested in an earlier comment. Please be more specific in identifying what sel of models are being described in each case, such as candidate models (ie .. the original published GMPES). common-form models (Le .. the mean and interpreted GMPEs and presumably the 2000 or 7500 count versions as well). representative model (i.e., the common-form model that best matches the mean hazard in a given cell), and the suite of representative models (i.e., the ones that are eventually used in the logic tree) 1155. Line 552 Please be explicit as to whether this paragraph is discussing the Fixed (refers to both sites) development of representative models for both sites or just PVNGS. 1156. Line 564 Please replace **magnitudefdistance" with "magnitude-distance." fixed 1157. Line 602 Please review the appropriateness of subscript k in NGk. given that there is already a sum over k. 1158. Lines 614-615 Please justify why uncertainty in Ztor is represented by adding 3 km to Ztor and not also subtracting 3 km and why the value of 3 km was chosen to represent this uncertainty (see previous comment). 1159. Lines 616-618 Please explain why a value for Zlor is needed in the R.1s*based models A qualifier has been added saying that "only one ZrnR value is when it was not used as a term in these models. ie., how can one Ztor used lo develop geometries for compatible distance metrics" value" be used if the models do not include Ztor at all? 1160. Line 629 Please correct the spelling of the second occurrence of "PVNGS" 'ixed 1161. Line 632 Please check whether the intent of this sentence would be more clearly fixed expressed if the final clause were included inside the parentheses. 1162. Line 633 It appears from Eq. 6.4-4 that it is the contributions to the Euclidean distance squared that are weighted by the weights from Eq. 6.4-7 (not the contributions to the Euclidean distance itself, as stated). Please correct or clarify. 1163. Lines 689-690 The phrase " ... then the point that corresponds lo the position of the candidate GMPEs is selected" is confusing. Please rewrite this phrase to make its meaning clearer. 1164. Line 704 Please correct the typo, i.e .. "two week" should be **too weak." fixed 1165. Line 706 Please provide a brief statement. or reference. that describes a "Voronoi-diagram" or the section(s) of an appendix where such a reference or definition can be found 1166. Lines 719-720 Is it true that all of the models within a given Voronoi cell do not really represent the same level of probability on the ground-motion distribution? If this is true, the use of equal weights is an assumption. Please justify the use of equal weights to determine the weighted mean hazard in each cell. 1167. Line 726 Please discuss the common form model that corresponds to the highest hazard curve in Figure 6.4.4-4 and explain why it falls so far above the cluster defined bv the rest of the models in the same cell. 1168. Lines 735-736 Although the distribution of HW models is nearly uniform for the DCPP representative models. the distribution of the hazard might not be. depending on what Voronoi cells received the higher HW models (i.e., the high-hazard cells or the low-hazard cells). Please justify that the mean hazard is not biased by the random selection of HW models. 1169. Lines 762-763 Please clarify what "results" are not sensitive to the discretization size of the Voronoi cells (i.e., the weights or the hazard). It is possible that the hazard will be sensitive to the size of the cells (e.g., what if only one cell were used?). 1170. Lines 804-807 Please show an example contour plot in Chapter 6 for those readers that do not care to read Appendix H. 1171. Lines 808-809 Please show an example distribution plot in Chapter 6 for those readers that do not care to read Appendix H. 1172. Line 879 Two consecutive figures are called "6.4.5-8." Please check and fixed renumber as needed. 1173. Lines 927-928 The sentence starting with "Randomizing" appears to be unconnected to the rest of the paragraph. Please expand or rewrite this sentence to better convev is meanina. 1174. Line 929 Please see the general comment regarding the documentation of the directivity model evaluation 1175. Lines 937-939 If the standard deviation represents the variability in the hypocenter location, please explain what the median (or should it be the mean) represents (e.g., the bias?). 1176. Lines 951-953 Please justify why it is not necessary to include Ztor as a directivity parameter for those events that do not rupture to the surface (e.g., the directivity effects for M5.5-6.5 events that the GMPEs were evaluated for). 1177. Lines 962 -964 Please include sufficient details of the Tl Team's evaluations of the technical merits and limitations of the simplified directivity model in support of the decision to adopt this model for use in hazard calculations (as also reQuested in one of the Qeneral comments). 1178. Lines 965-967 Please explain the basis for the evaluation that the simplified directivity model is a reasonable approach for capturing directivity effects (e.g .. was the hazard using the CY 14 directivity model and random hypocenters compared to that using the simplified model?). 1179. Lines 981-982 Please identify which event NGA EOI D 1017 represents and why it is justified to remove this event because the event-terms of the GMPEs are not consistent. 1180. Lines 990-991 Please explain why there is a difference in plotted values between Figure 6.6.1-2 and Figure 7.4.1-6. 1181. Lines 1008-1009 There seem to be two sets of LN values being given in this section. The -0.5 and +0.1 LN units listed in the previous paragraph appear to be biases in the log PSA values, whereas, the 0.32 and 0.35 LN units given in this paragraph appear to be standard deviations. Please make the distinction between these two sets of values clear in the text. Please also be more specific about what "numbers" (the biases or the standard deviations) the Tl Team considers to be "reasonable." 1182. Lines 1015 The use of the term "proponent model" or "proponent method" is confusing, since it can be interpreted as a model or method being proposed by a Proponent Expert (PE). If these models and methods are proposed by the Tl Team, please replace "proponent with "Tl Team" in this line and elsewhere in Section 6.7 where the term is used. 1183. Line 1036 Please delete the phrase "with similar rake, dip, width," which is incorrect based on the contradictory and apparently correct description given on Line 1039. 1184. Line 1039 Please note that this statement appears to contradict the phrase on Line 1036. which has been interpreted to be a typo in a previous comment. 1185. Lines 1064-1065 The sentence "The ground motions from the 2011 Fukushima-Hamadori earthquake are evalua1ed using the SRSS method in Section 9.1.5.2." appears to be disconnected from the sen1ences before and after it. It is also ambiguous what the "Therefore ... " at the beginning of the next sentence is referring to. Please rewrite these sentences to better convey their intended meanina. 1186. Line 1076 Please explain which complex rupture "Complex Scenario 18" represents. 1187. Line 1096 Please explain which splay rupture Splay Scenario 1 C" represents. 1188. Line 1300 Please confirm whether "Model A" should be included in the title to Table 6 4-2. 1189. Line 1343 Please confirm that the CB14 GMPE is plotted correctly in the lower plot (M6.6, SS, PGA). 1190. Line 1354 Please confirm that the GMPEs are plotted correctly in 1his plot. For example, CB14 appears to have a hinge or kink at M7, but its magnitude scaling term does not. 1191. Line 1359 Please identify the models listed in the legend to Figure 6.2.3-1 by their correct acronyms (i.e .. ASK14 instead of ASK). 1192. Line 1380 Please identify the models listed in the legend to Figure 6.3.1-2 by their correct acronyms (i.e .. ASK14 instead of ASK). 1193. Line 1386 Please identify the models listed in the legend to Figure 6.3.2-1 by their correct acronyms (i.e., ASK14 instead of ASK2014). Please also justify in the text why it is acceptable for the predictions from the proposed HW models to not encompass the predictions from all of the GMPEs. 1194. Line 1391 Please identify the models listed in the legend to Figure 6.3.2-2 by their correct acronyms (i.e .. ASK14 instead of ASK2014). Please also justify in the text why it is acceptable for the predictions from the proposed HW models to not encompass the predictions from all of the GMPEs. 1195. Line 1396 Please identify the models listed in the legend to Figure 6.3.2-3 by their correct acronyms (i.e .. ASK14 instead of ASK2014). Please also justify in the text why it is acceptable for the predictions from the proposed HW models to not encompass the predictions from all of the GMPEs. 1196. Line 1401 Please identify the models listed in the legend to Figure 6.3.2-4 by their correct acronyms (i.e., ASK14 instead of ASK2014). Please also justify in the text why it is acceptable for the predictions from the proposed HW models to not encompass the predictions from all of the GMPEs. 1197. Line 1406 Please identify the models listed in the legend to Figure 6.3.2-5 by their correct acronyms (i.e .. ASK14 instead of ASK2014). 1198. Line 1409 Please identify the models listed in the legend to Figure 6.3.2-6 by their correct acronyms (i.e .. ASK14 instead of ASK2014). 1199. Line 1432 In Figure 6.3.2-11, please justify in the text why it is acceptable for the predictions from the HW models to not encompass all of the predictions from the simulations 1200. Line 1438 In Figure 6.3.2-12, please justify in the text why it is acceptable for the predictions from the HW models lo not encompass all of the predictions from 1he simulations. 1201. Line 1444 In Figure 6.3.2-13, please justify in the text why it is acceptable for 1he predictions from the HW models to not encompass all of the predictions from the simulations. 1202. Line 1448 In Figure 6.3.2-14, please justify in the text why it is acceptable for the predictions from the HW models to not encompass all of the predictions from the simulations. 1203. Lines 1472 (Figure The plot for the Idriss model is labeled "114," inconsistent with "ld14" 6.4.1-4a), 1475 elsewhere in the chapter. Please modify for consistency. (Figure 6.4.1-4b), 1478 (Figure 6.4. t-Sa), and Line 1481 (Figure 6.5.1-Sb) 1204. Line 1529 In Figure 6.4.3-3, please explain the meaning of "NGAW2Pv-MED MODEL A" in the upper-left corner of the plot. 1205. Line 1552 In Figure 6.4.4-1, please explain the meaning of "NGAW2oc-MEo" in the upper-left corner of the plot. Please also explain what the different colors for the solid circles representing the GMPEs and their epistemic uncertainty refer to and what the grey circles represent. 1206. Line 1557 In Figure 6.4.4-2, please provide a legend for the color contours and explain the meaning of the grey ellipses and circles. 1207. Line 1567 In Figure 6.4.4-4, please define the axes labels and explain the meaning of "T001 DCCP4 MODELA" in the upper-right corner of the bottom plot. 1208. Line t 586 (Figure The caption states that the GMPEs are in black, but the legend indicates 6.4.5-2b) a different color. Moreover, the color assignments differ from those in Figure 6 4 5-2a Please modify for consistency between caption and leqend, and between the a and b parts of the figure 1209. Line 1623 In Figure 6.4.5-7, please justify why it is acceptable for the predictions from the proposed model to not encompass all of the predictions from the candidate GMPEs. The inference is that there is less than 5% confidence in those GMPE predictions that fall outside of the limits of the model. 1210. Line 1630 In Figure 6.4.5-8, please justify why it is acceptable for the predictions from the proposed model to not encompass all of the predictions from the candidate GMPEs. The inference is that there is less than 5% confidence in those GMPE predictions that fall outside of the limits of the model. 121 t. Line 1666 In Figure 6.5.1-3, please explain what directivity model is used to make the plot and where the epicenter andfor hypocenter is located on the fault. 1212. Figure 6.7.2-2 Please label the vertical axis and explain the meaning of the term fixed "ground motion factors" in the caption. 1213. Figure 6.7.2-3 Please identify the GMPEs associated with the respective colors, and fixed the meanings of the different styles of grey lines. and make improvements to the legibility of the figure (note also that the figure did not appear in its entirety in the supplied PDF version). Also please explain the meaning of the te1TT1 "ground motion factors" in the caption 1214. Figure 6.7.2-5 Please label the vertical axis and explain the meaning of the term fixed "ground motion factors" in the caption. 1215. Figure 6.7.2-6 Please identify the GMPEs associated with the respective colors, and fixed explain the meaning of the te1TT1 "ground motion factors in the caption CHAPTER 7-GMC Models for the Sigma: Overview and Methodology 1216. Lines 8-9 Please note that by the sigma terminology of Al Atik et al (2010) "single-Notation changed throughout the report and appendices station within-event" standard deviation should be "single-site within-(pending on Chapter 5) event" standard deviation. Please consider consistently using the terminoloav of Al Atik et al. (2010). 1217. Line 74 Please consider assigning the Zhao et al. (2006) model the acronym done used in Chapter 6 (i.e., ZH06) as shorthand in the remainder of the chapter. 1218. Line 84 Please add the missing words in this sentence (which currently reads ..to smooth" added before .. through" "and chose through the"). 1219. Line 87 Please consider revising "smooth" to "constant." "Smooth changed with "period-independent 1220. Line 155 Please consider using a different word than "proponent" on this line and Proponent changed to candidate" elsewhere in the chapter to explain the different Tau and Phi models so as not to confuse them with models that have been proposed by Proponent Experts (PEs). 1221. Line t77 Please rewrite the sentence beginning with "The mean 1 values .. " to Sentence is modified now (see answer to comment 197 better convey its meaning. The second half of this sentence appears to be incomplete. 1222. Line 183 Please correct the figure citation, which should be to Figures 7.2.3-2 and nxea 7 2 3-3 (not 7.2.3-3 and 7.2.3-3"). 1223. Line t91 Please replace the term "proponent" with the term "candidate" to be Done, see comment 155 consistent with terminology used elsewhere in the report. 1224. Line t95 Please replace the term "proponent" with the term "candidate" to be Done, see comment 155 consistent with terminology used elsewhere in the report. 1225. Line t97 Please rewrite the final sentence of the paragraph to clarify its meaning , (ie .. a "value" cannot be similar to a "model," so it is not clear what point Sentence rewritten as "The standard deviation of r was fitted the sentence is trying to convey). to a constant, period-independent function. The period-independent constant estimate is similar to the central model" 1226. Line 202 Please change Ci>6 to u,. done 1227. Line 207 Please replace the term "proponent" with the term "candidate" to be Done, see comment 155 consistent with terminology used elsewhere in the report. 1228. Line 232 Please describe the type of distribution used in the simulation. 1229. Line 269 Please indicate whether "Dawood et al. (2015 )" should be replaced with The correct citation is (2014) and is already included in the "Dawood et al., 2014 -in press" and, if not, please provide the reference reference list. The notation in press" has been removed from to the former. the text 1230. Lines 271-275 This paragraph appears to be contradictory and the Tl Team decision to use a magnitude-independent Phi_ ss is not well supported by the first sentence in the paragraph and the results in Figures 7.3.2-1. Please expand this paragraph to better discuss and justify the decision to use a maanitude-independent model for Phi ss. 1231. Line 273 Please correct the inconsistency between the phrase shown . . . for fixed four spectral periods and the list "(PGA, 0.1,0.5, 1.0,3.0 sec)," which (like the figure itself) includes five periods (PGA in addition to the four given spectral periods) 1232. Line 276 Please explain why the Phi_ss values of the GLOBAL datasets for each The reasons are described in Chapter 5. The Lin et al. dataset in GMPE are only shown for five periods in the figures and indicate, if only our possession had only those five periods. five values were used in the analysis, why Phi_ss values for the other oeriods are not used. 1233. Line 320 Please describe how 0.12 was derived. It is explained in Section 7.3.1. A cross reference has been added 1234. Line 388 Please avoid the use of the first person .. us." Verbiage changed to "makes it possible" 1235. Line 396 The statement that the between-event residuals were provided by the Sentence mildly modified to clarify the difference in the approach NGA-West2 developers is contradictory to the statement on Lines 404-between PhiSS (NGA residuals) and PhiSP-R(new residuals 405 that the Tl Team calculated the residuals. Please rewrite the text to from data recorded at Arizona stations not included in NGA-remove this contradiction. West2l 1236. Line 404 Please avoid the use of the first person "we." Since the use of first done person has appeared several times in this chapter, please search the entire chapter for other uses of first person and convert them to third person. 1237. Line 407 This statement is confusing and again suggests that the between-event See answer to 396 residuals provided by the developers are perhaps being used Please consider rewriting or expanding this entire section to make the process of developing the LD single-path standard deviations less confusing. 1238. Line 415 Please change 0W1; to fiW,,, Tl Team to evaluate if the formula is correct or not 1239. Line 730 In the Figure 7.2.4-4 caption, please consider replacing the word done "proponent" with "candidate" to be consistent with how these models are referred to elsewhere in the report. 1240. Line 744 In the Figure 7.2.5-1 caption, please consider replacing the word done "proponent" with "candidate" to be consistent with how these models are referred to elsewhere in the report. 1241. Line 469 Please explain what is the first issue. Verbiage modified to **An issue associated to" 1242. Line 784 In Figure 7.3.2-3, please consider showing the periods with average "no-Lin et al. Data" to show that these values are also bracketed by the low and hiah proposed values. 1243. Line 812 In the Figure 7.3.3-1a caption. please describe what the black solid and dashed lines represent. Also, in this and many other figures there are error bars on the symbols, but no mention of them in the legend or the caption. Please define the meaning of the error bars in this and other figures in this chapter and for similar figures elsewhere in the report where they might appear. 1244. Line 821 In the Figure 7.3.3-1 b caption. please describe what the black solid and dashed lines represent. 1245. Line 898 In Figure 7.4.2-1, this figure clearly demonstrates that the assumption An expanded discussion on lack of data to derive Phi_SP-R that the standard deviation is constant at low and high periods is totally above 2 seconds has been added unsupported by the data (note that the values at 0.2 sec were not used because of reliability issues). Please further justify in the text why it is Answer lo second part of the question is pending appropriate to extrapolate the first and last values as constant values to lower and higher periods and why the uncertainly should not become laroer at low and hiah periods oiven this added uncertaintv. CHAPTER 8-Median GMC Models: DCPP Sources 1246. Section 8.2.2, There does not appear to be a reference to Figure 8.2-3 Please check Fixed, now is quoted in Section 8.2.2 general comment and add a reference to this figure if one is missing. 1247. Lines 60-61 Please explain the bases for the values used to define the three branches and their weights included in the second node of Figure 8.2-3. 1248. Line 100 This is not necessarily true for the Akkar et al. (2014a,b) and Bindi et al. (2014a,b) GMPEs that were developed using subsets of the RESORCE database and with al least some interaction between them under the auspices of the SIGMA project. Please clarify this statement. 1249. Line 125 Please add the missing word "models" after "common-form". Fixed ("models" added) 1250. Line 167 Please improve clarity by adding a sentence break after the word Fixed "model." 1251. Lines 293-295 Please reference where in the report the evaluation of ld14 was done to determine that it was unreliable for RRuP < 3 km at large magnitudes. 1252. Line 302 Please indicate what models are being compared in Figure 8.4-8. The discussion references both the common-form models and the candidate GMPEs and it is not clear which is being referred to when not explicitly stated in the text 1253. Line 310 Contrary to this sentence, curves corresponding to the epistemic uncertainty are not included in Figure 8.4-9. Please add the curves or modifv this sentence to remove reference to eoistemic uncertaintv. 1254. Line 355 Please provide evaluations or provide a cross reference in support of the conclusion that "differences in the magnitude and distance scaling will also imoact the ranae of the hazard." 1255. Lines 360-361 Please explain what will need to be done if in the future the hazard model is changed. For example, will an evaluation of the GMC model need to be redone because its validity was based, in part, on the hazard calculated from a specific hazard model (i.e., hazard-calibrated)? If that is the case, it is important that such a caveat be clearly communicated in the report. Please note that there are other instances in this and other chapters where hazard was invoked as demonstrating that the range in the models is adequate, which should also be included as part of this comment. 1256. Lines 367-370 Please explain why the versions of the candidate GMPEs with added epistemic uncertainty are not considered in the comparison. 1257. Line 388 Figure 8.4-7 is missing or skipped over. Please correct this oversight. fixed 1258. Figure 8.2-2 Please correct the weight for "Sim_DC-MED," (i.e., shouldn't it be 0.25?). fixed 1259. Line 522 In Figure 8.4-1, please provide labels for the color legend bars and define what the light grey ellipses and points represent. 1260. Line 533 In Figure 8.4-2, please provide labels for the color legend bars and define what the light grey ellipses and points represent. 1261. Line 547 In Figure 8.4-3, please explain what DCPP Model A is, given that there appears to be only one DCPP model. 1262. Line 569 In Figure 8.4-6, there does not appear to be any "dashed black" lines. Please revise the caption to refer to the actual color scheme used in the fiaure. 1263. Line 580 In Figure 8.4-8, there does not appear to be any "dashed black" lines. Please revise the caption to refer to the actual color scheme used in the fiaure. 1264. Line 594 In Figure 8.4-9, there does not appear to be any "dashed black" lines. Please revise the caption to refer to the actual color scheme used in the fiaure. 1265. Line 645 In the Figure 8.4-14 caption, please describe what models the phrase "individual models" refer to. 1266. Line 651 In the Figure 8.4-15 caption, please describe what models the phrase "individual models" refer to. 1267. Line 656 In the Figure 8.4-16 legend, please refer to the various models by the acronyms used throughout the report (e.g., ASK14 instead of ASK). 1268. Line 662 In the Figure 8.4-17 legend, please refer to the various models by the acronyms used throughout the report (e.g., ASK14 instead of ASK). 1269. Line 665 In Figure 8.4-18, please define what the light grey lines represent in the legend or the caption. 1270. Line 670 In Figure 8.4-19, please define what the light grey lines represent in the legend or the caption. CHAPTER 9-Median GMC Models: PVNGS Sources 1271. Line 38 Please follow the standard practice of numbering figures in the order in The instance seems fixed, needs second check which they are first called in the text, which is not the case with the figure called on this line. 1272. Line 54 Chapter 6 of this report and the report on the SSC model use the term fixed "virtual fault", rather then "pseudo fault." Please revise for consistency with those other usages. 1273. Lines 74-75 The Akkar et al. (2014a,b) and Bindi et al. (2014a,b) GMPEs were developed using subsets of the RESORCE strong-motion database under the auspices of the SIGMA project. Please indicate that these two models are likely correlated. although perhaps not to the extent of the NGA-West2 models. Please also note that this is not an issue. since epistemic uncertainty was applied to these models as well as to the NGA-West2 models. 1274. Line 108 Please specify the type of "residual" (i.e., between-event). 1275. Lines 173-174 The sentence beginning "The limitation ... " is confusing. Please reword it or expand it to make its meaning clearer. 1276. Line 187 Please make it clear which mechanism each of the weights refers to. 1277. Line 256 Please correct the figure reference; the reference to Figure 9 .1-10 should actually be to Figure 9.1-9. 1278. Line 371 Please correct the figure reference on this line (it should be 9.1-19). The instance seems fixed, needs second check 1279. Lines 475-476 Please indicate where the technical justification and bases for these statistical weights are given (i.e., Appendix P). 1280. Lines 478-481 The stated justification seems weak; there are few recordings at 200 to 400km distance range in the ground-motion database. On the other hand. it would appear that there is no need to consider directivity because its effect, as modeled in CY14, is zero at such large distances. Please revise to clarifv the iustification for the Tl Team's iudament. 1281. Line 545 In the heading of the last column in Table 9.1-1, please replace the term "SFO" with "SOF' to represent style of faulting. 1282. Line 557 In Figure 9.1-2a, please label the color legend bars and describe what the light grey ellipses and circles are on the plots. 1283. Line 567 In Figure 9.1-2b, please label the color legend bars and describe what the light grey ellipses and circles are on the plots. 1284. Line 577 In Figure 9.1-3a, please label the color legend bars and describe what the light grey ellipses and circles are on the plots. 1285. Line 587 Figure 91-3b, please label the color legend bars and describe what the ligh1 grey ellipses and circles are on the plots. 1286. Line 607 Please provide a specific reference 1o "Akkar et al." 1287. Line 637 In Figure 9.1-8, the plots do not appear to have any "dashed black" lines. Please revise the text to better describe the lines. 1288. Line 645 In Figure 9.1-9, the plots do not appear to have any "dashed black" lines. Please revise the text to better describe the lines. 1289. Line 653 In Figure 9.1-10, the plots do not appear to have any "dashed black" lines. Please revise the text to better describe the lines. 1290. Line 661 In Figure 9.1-11, the plots do not appear to have any dashed black" lines. Please revise the text to better describe the lines. Please also further justify in the text why it is acceptable for some of the predictions from the GMPEs to fall outside of the range of the representative models at some periods. Note the concern in previous comments of using only the hazard distribution alone to justify the range in the representative suite of models. 1291. Line 709 In the Figure 9.1-13 caption, please describe what is meant by "individual models," and consider making changes such that the upper and lower parts of the fiaure have the same vertical scale. 1292. Line 714 In the Figure 9.1-14 caption. please describe what is meant by individual models. 1293. Line 718 In the Figure 9.1-15 caption. please describe what is meant by individual models. 1294. Line 724 In the Figure 9.1-16 caption. please describe what is meant by individual models. 1295. Line 729 In the Figure 9.1-17a caption, please describe what is meant by selected models." Please consider using a consistent set of terminology for the different types of models that are described throughout the report to make it less confusing to the reader. Please also use a consistent set of acronvms in the leaend Ce.a, ASK14 instead of ASKJ. 1296. Line 738 In the Figure 9.1-17b caption, please describe what is meant by "selected models " Please also use a consistent set of acronyms in the legend (e.g., ASK14 instead of ASK). 1297. Line 742 In the Figure 9.1-18a caption, please describe what is meant by "selected models." Please also use a consistent set of acronyms in the legend (e.g., ASK14 instead of ASK). 1298. Line 748 In the Figure 9.1-18b caption, please describe what is meant by "selected models." Please also use a consistent set of acronyms in the legend (e.g., ASK14 instead of ASK). 1299. Line 759 In Figure 9.1-19, please use a consistent set of acronyms in the legend (e.g., ASK14 instead of ASK). 1300. Figure 9.2-1 Please correct the abbreviation for the Idriss (2014) model to be fixed consistent with usage elsewhere in the report. CHAPTER 10--.. Model Logic Tree for both DCPP and PVNGS 1301. Lines 25-26 Please also mention that the standard deviations of ASB14 and Bi14 are independent of magnitude. which was an important property of the models that the Tl Team used to reiect them. 1302. Line 38 Although the use of the term "proponent" in this context is technically fixed correct, it is inconsistent with the term "candidate" used throughout the report to identify such proponent models. Please consider replacing proponent" with candidate" lo be consislenl wilh the descriplion of such models throughout the report 1303. Line 47 Please add the term "scaled" before "Chi-square distribulion." fixed 1304. Lines 51-53 The three-point approximation scheme (as described in Appendix P) applies (0.2, 0.6, 0 2) weighs to the (5th, SOth, 95th) percentiles. Please explain the appropriateness (or point to a place where such explanation was given) of giving a 0.6 weight to the central branch representing the mean (which may not be the SO"' percentile of a Chi-square distribution). CHAPTER Model Logic Tree: DCPP 1305. Line 27 Please clarify if interpolation and extrapolation were also needed for the Done. The issues does not exist for the California data California-only data subset, which includes data at the full set of spectral oeriods. 1306. Line 53 Statistical evaluation of the standard error of ?ss was not given in Reference to Appendix P is now removed Appendix P. Please verify and correct the cross reference as needed. 1307. Lines 53-58 Please refine this paragraph to give a clear and accurate summary of the approach described in Section 7.3.1. 1308. Line 64 Please qualify the term "correlated" in a way that is similar to Lines 4-5 done of Chapter t2. 1309. Line 71 Please consider revising the term "intra-event" to "within-event" to be Done throughout the chapter consistent with the terminology generally used throughout the report. 1310. Lines 78-79 and 88-Please define the level of significance for the presumed departure from 89 normality. It might be obvious to the Tl Team, but not necessarily to the reader, that a point falling outside the 95% confidence interval can be considered to depart from normality at the 5% level of significance. Besides, others might consider "significant" to be at the 10% level of sianificance 131 t. Line t05 Please be specific whether the same weights of the mixture models that were found to be appropriate for CY14 are "similar" or the "same" as found for ASK14. 1312. Lines 108-112 Please provide a context for this paragraph. 1313. Line 127 Please insert a space after ok 1314. Line 133 Please consider revising the term "intra-event" to "within-event" to be Done (See reply to 71) consistent with the terminology used throughout the report. 1315. Line 188 In the Figure 1 t-2 caption, please consider revising the term "intra-done event" to "within-event" to be consistent with the terminology used throughout the report and define the meaning of the term "normalized." Please also define the solid and dashed red curves. In addition, note that panel b) is stated as being for T=2 sec, but the y-axis label indicates it is for T=0.5 sec. Please correct this inconsistencv. 1316. Line t91 In the Figure 1 t-3 caption. please describe what type of "residuals" are done referred to in this figure. Please also define the solid and dashed red curves. 1317. Line t94 In the Figure 1 t-4 caption. please describe what type of "residuals" are referred to in this figure. Please also define the solid and dashed red curves and provide the missing red curves on the right plot. 1318. Line 201 In Figure t 1-5, both of these plots appear to be incomplete and the left plot is not consistent with the right plot. Please correct these plots to be consistent with other similar plots in the chapter. 1319. Line 212 In Figure 11-6, both of these plots appear to be incomplete and the left plot is not consistent with the right plot. Please correct these plots to be consistent with other similar plots in the chapter. 1320. Line 218 In Figure 11-7. both of these plots appear to be incomplete and the left plot is not consistent with the right plot. Please correct these plots to be consistent with other similar plots in the chapter. CHAPTER 12-<j> Models Logic Tree: PVNGS 1321. Lines 3-5 The first paragraph appears to be awkwardly placed. Please consider Paragraph moved to second position. placing this paragraph in a more appropriate place in the chapter. 1322. Line 45 Please remove the reference to DCPP, since this chapter addresses the done Phi model for PVNGS 1323. Line 69 Please correct "biased-corrected" to "bias-corrected." fixed 1324. Line 90 Lines 486 and 487 on Page 7-16: CV=0.17 of (h*. was based on the variability and the mean of estimates for the four individual GMPEs. Please clarify or correct the statement "based on sample size" in the case of 1325. Line 146 Please replace "02 with "0.2. fixed CHAPTER 13-Total Sigma Model 1326. General The use of the term "total sigma" instead of the more accurate "total The term is intentionally used generically as two types of total single-site sigma" tends to neglect the fact that only a single-site sigma sigma values are in fact generated, one for the single station model was adopted. Please consider replacing the term "total sigma" sigma and one for the similar path to a region. These are with "total single-site sigma" to emphasize this point. indicated by the appropriate subscripts on o. No change needed 1327. Line 7 Although the Greek letter "1p" and the Greek symbol "4'"both represent q> was replaced with ¢ Phi, it is common in engineering seismology lo use the latter. which has also been used elsewhere in this report to represent Phi. Please select one of these letters/symbols to represent Phi and use it consistently throughout the report in order to avoid confusion. 1328. Line 10 Eq (13-1) is very generic and does not represent the actual aleatory The equation is intentionally generic as described in the variability models that are proposed. Please consider replacing this subsequent paragraphs. (see response to 1 334) equation with two equations: one that represents the total single-site sigma without path terms and one that represents the total single-site siama with oath terms, as discussed in the text that follows the eauation. 1329. Lines 30-31 Although the use of only a total [single-site) standard deviation epistemic The person would have to construct individual models for tau logic tree is conceptually fine. it appears to prevent the ability lo test the and phi. The necessary information is provided. sensitivity of the hazard results to the individual between-event and single-site within-event epistemic uncertainty models. Since sensitivity to each type of model is provided in Chapter 14, please explain how someone else can test this sensitivity given that the final model presents only a single total [single-site) sigma model. 1330. Line 55 Please replace the term "cumulative distribution" with the more accurate term "cumulative distribution function. 1331. Line 57 Please add a sentence to explain the utility of Eq (13-3). Will add the sentence The cumulative distribution function is used to develop the discrete approximation used in the logic tree formulation to represent the uncertainty in the variance parameter 1332. Line 61 Please correct the missing factor of two in Eq ( 13-5) (this typographical fixed error is noted here just as a reminder: it has already been noted by the Tl Team). 1333. Lines 62-63 Please further describe these analyses or provide a reference where the results of these analyses can be found. 1334. Line 66 Please correct a possible typo: should oss be changed to 4';s? 1335. Line 75 Please correct a possible typo: should <l>ss be changed to ass? 1336. Line 77 Please correct the typo ("bi-linear") and add the missing word (i.e., fixed missing "to" in "leads to"). 1337. Line 79 The Tl Team responded to PPRP's Comment 175 by adding the sentence "Appendix P presents typical examples of the calculations." However, such example calculations were not given in Appendix P. Please orovide these missina calculations. 1338. Lines 89 and 90 To be consistent with the usage in the embedded table on Line 93, please consider adding subscript "SS" to symbol c;. 1339. Line 90 Please assign the embedded table a number and a title so that it can be Fixed throughout the Chapter referenced by table number if needed, and correct any subsequent table numberino as necessarv. 1340. Lines 98, 99 and too Please explain why directly computed ass at magnitudes between M 5 and M 7 at 0.1 units were not used in fitting Eq (13-8)? 1341. Lines 102-103 Please provide a reference for the statement beginning "Minimization of the difference .. " 1342. Line t18 Please check the correctness of the reference to Section 13.1: should it be Section 13.2? 1343. Line t54 Please clarify whether "the method" refers to the semivariogram analysis fixed method (i.e., the current sentence construction leaves some ambiguity). 1344. Line t60 The Tl Team presented its evaluation and decision on the modeling of the effects of spatial correlation on crss for the magnitude-independent crss model only. Please also provide discussions for the magnitude-dependent cr" models. 1345. Line 184 Please repair the typos on this line. fixed 1346. Lines 267. 270 and Please indicate in each figure which branch includes the spatial-273 correlation effect on cr". CHAPTER 14-Hazard Sensitivity 1347. Lines 7-8 It appears awkward to state that the hazard sensitivity analyses for the final GMC model was done on preliminary versions of the SSC models without providing some sort of caveat. This can be avoided by stating that it is the responsibility of the individual NPPs to conduct thorough sensitivity analyses for their individual sites and that the sensitivity results provided herein are for demonstration purposes and for purposes of makina hazard-informed decisions. 1348. Line 60 There is no mention of deaggregation in the introduction to this chapter. Please introduce this concept and discuss what it is used for in the introduction to the chapter prior to presenting the deaggregation results. 1349. Line 81 Please add the term "mean" before "hazard level" to be clear that the results represent the mean and not some other fractile (e.g., the median) hazard. Hazard is used without prefacing it by mean many times throughout the chapter. If mean is not added to all of the instances where the hazard level is mentioned, then please state that this is the case for the remainder of the chaoter in order to avoid confusion 1350. Line 88 Please consider rewriting the caption (ie., the "hazard at hazard" Captions changed. Now they read "Deaggregation juxtaposition somewhat obscures the meaning). of reference site condition (V530 of 760 m/s) hazard at mean annual. .... " 1351. Line 103 Please define the term "sensitivity case" and be as specific as possible about what figure(s) are being referenced in the discussion. 1352. Line 116 The text on this line states that HW Models 5, 11 and 21 were selected Fixed for the 0.5 Hz tornado plots, but the figure legends for the 0.5 Hz cases indicate that Models 5, 13 and 23 were used. Please check and correct as necessarv. 1353. Line t51 Although the sigma model started as separate Tau and Phi_ss models. in the end a single total single-site sigma model was used. Please acknowledge that here and describe that the individual Tau and Phi_ss models were used for purposes of the sensitivity analyses. Also describe how the user of the model can conduct a similar sensitivity analysis usina their own hazard code. 1354. Line 152 This statement implies that "Model 1" is always the central model of the representative suite of models. If there is some numbering convention for these models, please describe that convention. 1355. Line 168 It is awkward that the first sensitivity analysis appears on the fifth line of the tornado plot. Please consider here and elsewhere in the chapter discussing the sensitivity cases starting with the top line of the tornado plot and descending down the plot to make the discussion less confusina. 1356. Line 247 The terminology used here is confusing, at best. and doesn't seem to First comment fixed. have a useful purpose. The dichotomy "seismogenic sources versus Seismic source input is what gets fed into the hazard code. so the "tectonic sources" does not seem meaningful. Why are the former not tell'Tl has not been changed. simply called areal sources. since the other type -tectonic sources -are Third comment fixed also seismogenic sources? Further, in the next line, "Seismic source input" is used; what is the difference between seismic source and seismogenic source? Finally, in Line 251, "areal seismic source" is used. This paragraph needs to be rewritten with consistent. conventional tenninology. 1357. Line 266 There is some confusion as to the use of the term "Sonora Basin and We think that the qualifier at the beginning of the paragraph is Range. The SSC model uses the term "Southern Basin and Range". sufficient to state that these names are from the SSHAC L.2 Here, you seem to indicate that the "Sonora" component of this tenn is PVNGS effort. derived from the Lettis (20t3) SSHAC2 report This needs to be made clearer. and it would also help if it were made clear that this region is Needs double checking now referred to as the Southern Basin and Range, especially as the Mexican Highland Basin and Range is in Sonora, Mexico. 1358. Line 270 Baja is not the name of the Mexican State that occupies the northern hal1 We think that the qualifier at the beginning of the paragraph is of the Baja California peninsula. It is Baja California. If this term is in sufficient to state that these names are from the SSHAC L.2 reference to that used in Lettis (2013), please make that more clear by PVNGS effort. also referencing its current usage as Baja California in the SSC report Needs double checking 1359. Lines 27 4-302 Some of the faults have "fault" in their listed name. whereas others do Fixed not. Is there a reason for this. and if so. please explain. Alternatively. make them consistent. 1360. Line 401 Please describe what is meant by the term "wider tail" in this context. 1361. Line 449 Here it states that the discussion will only address the 0.5 Hz SA Fixed sensitivities. whereas in the following text, the figures addressing the 5 Hz sensitivities are also cited (Lines 462-463, 466 and 477). Please clarify. 1362. Lines 451-452 Please be as specific as possible about what figure(s) are being referenced in the discussion. Please also be more specific when describing the sensitivity cases. For example, the first sentence mentions "the first sensitivity analysis" and the second sentence mentions "these sensitivity cases," without indicating how these two descriptions are related. Since there are a lot of repetitive statements in the text describing the sensitivity analyses and/or sensitivity cases. this comment applies throughout the chapter: please make it clear what sensitivity analysis and/or case is being discussed at any given time and where that analysis and/or case can be found on the tornado plot. 1363. Line 465 Section 7.4 .1 does not include a discussion of additional epistemic uncertainty at large magnitude. Please provide the correct cross-reference. 1364. Line 468 Please add "types" between '"two" and "common form models" in order to avoid confusion. 1365. Line 506 Please clarify what "Model 1" refers to on this line. That is the same approach followed in Section 14.2.1. Model 1 is the central model in the ellipse. A qualifier has been added 1366. Line 510 Please consider replacing the term "average" with the term "central" so as not to imply that it is intended to represent the mean (average) hazard. 1367. Line 511 Figure 14.3-10a is cited on this line, but the discussion appears to refer fixed to the case shown in Figure 14.3-9. Please check and correct as aporooriate 1368. Line 517 Figure 14.3-9b is cited on this line, but the discussion appears to refer to the case shown in Figure 14-10a. Please check and correct as aooropriate. 1369. Lines 594-595 Please add "types" between "two" and "common form models" in order to avoid confusion. 1370. Lines 609 and 617 Figures 14.3 (a and b) are cited, but in Line 605, it is stated these would Fixed in both instances not be discussed further Please clarify. CHAPTER 15-Application Guidelines and Limitations 1371. Line 5 Please provide a cross reference to the adopted kappa value of 0.041 s. Reference added to Section 5.3.3 and Appendix M 1372. Lines 5-8 Please provide a cross reference to the section where evaluations are presented to support the claim that epistemic uncertainty in kappa is captured by the variation in high-frequency spectral shape within the SWUS GMC common-form models. 1373. Lines 12-14 Please give the purpose for providing a representative Vs and density profile and what they can or should be used for, or delete this discussion from the report. Without such a statement of purpose. it is ambiguous why these profiles are presented. For example, if they are provided for purposes of documenting what was used to estimate the host kappa values for the NGA-West2 GMPEs, then their discussion should be part of the appendix that discusses the host kappa value determination. If they are meant to be representative of the site response predicted by the site terms in the NGA-West2 GMPEs, that has not been shown to be the case for these GMPES and is certainly not the case for the European or Japan GMPEs, which are likely represented by totally different Vs and density profiles CHAPTER 16-References 1374. Please carefully review these references for completeness and accuracy Ongoing and for consistency with the references provided in each chapter. From: Carola DiAlessandro Sent: Monday, March 09, 201511:44 AM To: Steven Day; Kenneth Campbell; Brian Chiou; Thomas Rockwell

Subject:

FW: directivity sensitivty study

Dear PPRP,

Please find enclosed the document that shows the similarities in hazard results between the Lamprey and the CY14 approaches for directivity. We hope this document satisfies your concerns, and can be assessed by the Panel in view of the Closure Letter. We are planning to insert this document in our report, integrating the text as appropriate in the Section 6.5. Thanks, Carola Di Alessandro, Ph.D. Project Manager for the SWUS GMC SSHAC GeoPentech, Inc. 525 N. Cabrillo Park Drive, Suite 280 Santa Ana, CA 92701 Mobile: 510-491-6713 Fax: 714-796-9191 Office Phone: 714-796-9100 Emai I: ca rola_dia lessandro@geopentech.com To: John Barneich and Norm Abrahamson From: Steven Day, PPRP Chair, SWUS GMC SSHAC Project Date: September 17, 2012

Subject:

Draft Comments on the SWUS GMC Project Plan The following is the review by the Participatory Peer Review Panel (PPRP) of the draft Project Plan (draft dated August 2, 2012) for the Southwestern U.S. Ground Motion Characterization (SWUS-GMC) SSHAC Level 3 study. Overall, the Project Plan document is well prepared, explains the SSHAC Level 3 guidelines well, and provides a framework for successful implementation of those guidelines. The panel recommendations fall into two categories. First. we recommend an augmentation of the Technical Integration (TI) team to better represent the mix of technical methods to be employed. Second, we recommend additions and clarifications to make some aspects of the plan more explicit and improve its internal consistency. Technical Integration (TI) team A substantial component of the project entails evaluation of the validity and limitations of numerical simulation methods. In the current Project Plan draft, the project relies heavily on an anticipated Southern California Earthquake Center (SCEC) numerical simulation validation report as a basis for evaluation. The panel agrees that the SCEC study may provide a valuable resource for the TI team, but also believes that the Tl team needs to have its own expertise in this area if it is to undertake the comprehensive evaluation of proponent models required in the context of a SSHAC study. The Project should therefore add another member to the TI team to bring additional expertise in methods and application of numerical modeling for ground motion estimation. It is also important that the added TI team member be an experienced scientist or engineer with a well-established professional or academic reputation, in order to bring the team a more appropriate balance between experienced experts and more junior members. Additions and Clarifications 1. The draft plan includes a brief summary of the NGA-West2 GMPEs, but that summary does not include enough detail to provide understanding of all its purposes and products. It would be useful to include a short appendix that does so. 2. The Project Plan should provide for comprehensive documentation of the numerical simulation methods. That documentation should be completed and made available to the evaluation team and PPRP in advance of the assessment of the simulation results. This document should reference previously published papers to supply supporting technical description and/or analysis and should clearly note the subsequent changes to the simulation methods that were introduced prior to their application to the SWUS project.

3. (Page 4) On other projects, the terminology distinguishes the roles of "TI Team Evaluator Experts," and "TI Team Support Technical Staff' or "TI Team Resource Experts." We believe that the term "Evaluator Expert" should be used only lo describe the Tl Team members who will have ownership of the results. 4. (Page 5) A potential concern is how differences in code implementation (particularly, for complex fault geometry, such as bending and branching faults) might influence the hazard analysis results. If the three hazard analysts plan to use different hazard analysis codes, will the project address this issue (if it is not already addressed in PEER's hazard code verification project)? 5. (Page 8) The project plan should briefly describe the mechanism for storing and disseminating various documents. 6. Task 2 (page 9) gives some examples of GMPEs developed outside of PEER that may be applicable. Since PVNGS is in an extensional tectonic environment. it would be appropriate to also explicitly note one or more examples from such an environment (e.g., Italy). 7. Project plan (page 9, 3rd paragraph, line 5) indicates that both traditional ergodic sigma and single-station sigma are included in the new PEER GMPEs. This contradicts the statement in the kickoff meeting that single-station sigma will not be part of the new GMPEs. If the latter is correct, this should be corrected in the project plan document. 8. Several other non-PEER tasks (page 9) were mentioned in the kickoff meeting, and, if these are to be part of the SWUS GMC project, there should be some discussion of these tasks in the plan. 9. The Project Plan should include a discussion of the contingency plan for the possibility that SCEC is unable to finish its validation of the numerical models (and provide a recommendation and associated documentation) by an appropriate cutoff date. 10. In the discussion of each workshop (e.g., Task 3, page 10), there is a description of a process for PPRP caucusing and reporting. (i) Post-workshop caucus. This function would better be described as PPRP deliberations, and the language should preserve the PPRP' s option of completing them later via phone and/ or email (e.g., in the event that schedule conflicts prevent the full panel convening immediately after workshop completion). (ii) Written comments. There is reference to written comments and feedback to the PTI and TI team at the time of the half-day workshop deliberations. But there is also a reference later on to the PPRP submitting a letter providing observations on the workshop. The Project Plan should be edited to clarify that the PPRP will provide only verbal comments and feedback to the PTI and TI team at the conclusion of each workshop. with the written version of the PPRP comments provided at a later date (so that they can be carefully edited and a PPRP consensus built and confirmed). 11. Under "Topics to be addressed at Workshop 1" (page 11 ), there are a few points that might benefit from some clarification. First, we suggest that there be an item explicitly mentioning the identification of data needs or gaps, as that is one of the essential purposes of the first workshop. Also, because specific mention is made of reviewing GMPEs from PEER, it might be appropriate to also explicitly mention the review of non-PEER GMPEs in this list. There is also a reference to "moderate (M 5.5-6.5) earthquakes occurring 30-100 km from a site." What is the basis for selecting this distance range? Does this M-R range matter to DCPP and SONGS? Finally, on the same page, there is a reference to selecting "a representative reference VS30 that is applicable to all three sites." Have all three PTis agreed to this? 12. Since the hazard analysts have been named in the Project Plan, it would be good, in the interests of consistency, to outline their qualifications in the appendix (and note this at the appropriate point in the main text), just as you have for all the other named participants (it may seem odd if they are singled out for omission). Minor editorial notes and comments. Page i (Table of Contents): Page numbers should be updated to be consistent with the current version 'INTRODUCTION AND CONTEXT OF TllE STUDY' should be included. 'APPENDIX A, should be included. Page 1: First paragraph notes a SSHAC level 3 requirement for all operating nuclear power plants. Is this true for CEUS plants (or are they allowed to perform Level 2 study)? Figure 2 could be improved by showing the schedule in a chart. similar to the one shown by John Barneich at the kickoff meeting. It would be helpful if this chart also shows the schedules of the 3 SSC studies, as was done in John's chart. Page 2: L12, should be NRC, 2012 (not 2011). Page 3:

First line of Project Sponsor description, should say "provide" (not "provides"). Page 4: "Evaluator Expert (EE)" is not shown in the organization chart (Figure l ). Line 6, typo "and" (delete "s") 3rd paragraph, "The REs provide their specialized knows to ... ", knows should be changed to "knowledge". Page 5: 1. 5 lines from bottom, with reference to "applicability of NGA-West2 .. to the SWUS region." Perhaps the issue should be stated as applicability to the three SWUS sites of interest, since each might require its own adjustment to the ground motion model(s). Page 6: 8th line of the SWUS GMC WORK PLAN ... section, I think you mean "By receiving feedback ... ", rather than "by providing feedback ... " Second line from bottom, end of sentence, delete extra period Page 7: 4*h paragraph, line 3 -"There may also be site-specific versions of the GMC logic tress to address site-specific issues .. ". We suggest changing "versions" to "modifications". Page 8: I 0 lines from bottom, "database" should be one word. 5 lines from bottom, "outlines" (not outlining) Page 9: First line of last sentence, "a major" (not "an") Line 4, "subsequent to the kickoff meeting" (the PPRP letter will not be prepared until after the Kickoff Meeting) I st paragraph, line 3 -"Training on the SSHAC process will also take place at the off meeting." This training was not listed in the kick-off meeting agenda. Terms "ergodic sigma" and "single-station sigma" should be (briefly) defined. First line, last paragraph, "a major" (not "an") Page 10: Final paragraph, first line, delete extraneous "the" (before "Workshop 1") and "as" (before the word "mainly") Second line of Task 3 section, " ... list of RE' s will be provided to the PPRP ... " (the words "will be" are missing) Page 11: Fourth item in topics list, extraneous word "the" (before "PEER") Correct the subscript formatting in item 8, and eliminate period (for parallelism with other list items) Page 12: Line 3, "Vl" (rather than "VO") In Task 5, state that the latest version of the SSC model will be implemented in the hazard sensitivity analysis. Second to last line, typo: "identify" (not "indentify") Page 13: Line 4, "Database Manager" is not shown in the organization chart. Does the SWUS GMC study have a database manager? Third line from bottom "the Final Report" (missing "the") Page 14: Line 2, extraneous "the" (before "Workshop") Page A-1: Second line, second paragraph, extra space in "internationally recognized" Third paragraph: technically, the 1996-1998 Yucca Mountain project was not a SSHAC study, since the SSHAC process had not been finalized yet-perhaps a qualifier is in order here. Three lines above Table la, delete "as" Page A-2: Table lb, line 2, you probably mean "GMC issues" rather than "SSC issues" 6 lines from bottom, there is a typo in NGA-East Page A-4: Dr. Campbell's bio is not up to date, especially with respect to his experience in SSHAC projects. His bio should be updated as follows: "Dr. Kenneth Campbell is a recognized expert in ground motion and seismic hazard. He has over 30 years experience in developing empirically based GMPEs. He was one of the GMPE developers in the 2008 NGA project and is a developer of updated GMPEs in the ongoing NGA-west2 project. Dr. Campbell also has extensive experience with the SSHAC process. He participated as an expert evaluator in the 1998 Yucca Mountain SSHAC level 4 GMC and is currently an expert evaluator in the ongoing SSHAC level 4 GMC study for the PEGASOS refinement project and Chair of the PPRP in the ongoing SSHAC level 3 GMC study for the Hanford PSHA. In addition, Dr. Campbell has served as a PPRP member for the 2011 BCHydro SSHAC level 3 SSC and GMC studies, was a resource expert in the 2004 EPRI CEUS SSHAC level 3 GMC study, and was a proponent expert for the hybrid empirical method of modifying GMPEs for regional factors in the Blue Castle and Thyspunt SSHAC level 3 GMC studies." Third paragraph, third line, "his key expertise" (rather than "he"): fifth line, "resource expert" (rather than "participant"); sixth line, "Blue Castle" (spelling). Page A-6: Line 1, "PM" (rather than "PPRP") Table 3A, row 2, change "QA" to "QA Staff' Table 3A, Line 3, "development of and adherence to" November 3, 2012 Carola Di Alessandro, Ph.D. Project Manager for the SWUS GMC SSHAC GeoPentech, Inc. 525 N. Cabrillo Park Drive, Suite 280 Santa Ana, CA 9270 I

Dear Dr. Di Alessandro:

The Participatory Peer Review Panel (PPRP) has reviewed the Project Plan (dated October 3, 2012) for the Southwestern U.S. Ground Motion Characterization (SWUS-GMC) SSHAC Level 3 study. The Project Plan document is well prepared, explains the SSHAC Level 3 guidelines well, and provides a framework for successful implementation of those guidelines. The Plan calls for an additional member, not yet named, to be appointed to the Technical Integration (TI) team to provide expertise in numerical ground motion simulation. That appointee should be knowledgeable with respect to the techniques employed in such studies, as well as knowledgeable in the appropriate selection of model parameters for those studies. We look forward to seeing that position filled by an experienced scientist or engineer with a well-established professional or academic reputation, so that this appointment will also bring the TI team an appropriate balance between experienced experts and more junior members. The PPRP requests that some clarifying language be added to the plan, as noted in an attachment to this letter. The panel believes that, with these clarifications, together with the augmentation of the TI team described above, the Project Plan has the elements required for meeting the SSHAC Level 3 objectives. We thank the project team for its efforts in developing the plan and look forward to its implementation. Sincerely, Steven M. Day Chair, PPRP Brian Chiou Member, PPRP Kenneth Campbell Member, PPRP Thomas Rockwell Member, PPRP

Attachment:

Requested clarifications and edits Attachment to PPRP letter of November 3, 2012 Requested clarifications to SWUS GMC Project Plan 1. It still does not appear to us that the project plan spells out clearly that comparison tests will be m<1de of the different h<1zard codes used by the three utilities, as discussed in our initial review1, <1nd we request that this be addressed. 2. The Project Pl<1n stipulates that the PPRP will meet for a half day after Workshops 1 <1nd 2, and we reaffirm our requestz for a modification of the language to note that the PPRP will have the flexibility to complete its post-workshop deliberations by teleconference and/or email. We feel that occasionally, due to scheduling or personal difficulties, those other arrangements may be the optimal way to insure full participation of the panel. 3. The project pl<1n notes that documentation of the numerical simul<1tion methods will be part of the project database, but does not address our concern that the documentation be available to the PPRP in advance of the time when the models are evaluated3. For models like these being developed via university research, it is reasonable to be concerned that insufficient documentation may be available at the time of model evaluation. Hence, it is important that the Project Plan be clear about the documentation ground rules and the consequences of insufficient documentation. Minor editorial notes (i) Page 18, row 5 (Compile Regional GM data for Arizona): Although this work has been discussed during the working meetings and it is clearly important, it was not mentioned in the main text of the Project Plan, so we suggest removing it from Figure 2 or adding some discussion to the Project Plan. (ii) It would be helpful to have the TI Te<1m briefly describe how the simulated dat<1 will be used in the GMC study, in particular in the construction of the logic tree (e.g., will there be branches based on the simulation results?). (iii) Page 12, 2nd paragraph --typo 'Wworkshop' (iv) P<1ge 12, 7th bullet --'as distances' should be 'at distances' 1 PPRP review memo dated 9 /17 /2012, see Note 4 2 Ibid, Note 10 Note 2 November 29, 2012 Carola Di Alessandro, Ph.D. Project Manager for the SWUS GMC SSllAC GeoPentech, Inc. 525 N. Cabrillo Park Drive, Suite 280 Santa Ana, CA 9270 I

Dear Dr. Di Alessandro:

The Participatory Peer Review Panel (PPRP) has reviewed the Project Plan (dated November 12, 2012) for the Southwestern U.S. Ground Motion Characterization GMC) SSHAC Level 3 study. The Project Plan document is well prepared, explains the SSHAC Level 3 guidelines well, and provides a framework for successful implementation of those guidelines. It is responsive to earlier PPRP's rernmmendations, as detailed in our memoranda dated September 17 and November 3, 2012, respectively. The Plan includes a Technical Integration lTI) team that brings the project an appropriate balance between experienced experts and more junior members, and includes high-level expertise in both empirical and simulation-based ground motion estimation. The PPRP believes that the Project Plan has the elements required for meeting the SSHAC Level 3 objectives. We thank the project team for its efforts in developing the plan and look forward to its implementation. Sincerely, Steven M. Day Chair, PPRP Brian Chiou Member, PPRP Kenneth Campbell Member, PPRP .. , .,,,-.. /.. ': ; \. .;;,;t/ --' :/* .,,, / .1 ,A-" ..* $') ....... Thomas Rockwell Member, PPRP April 21, 2013 Carola Di Alessandro, Ph.D. Project Manager for the SWUS GMC SSHAC GcoPentcch, Inc. 525 N. Cabrillo Park Drive, Suite 280 Santa Ana, CA 92701

Dear Dr. Di Alessandro:

This letter provides comments from the Participalory Peer Review Panel (PPRP) on Workshop No. 1 (Significant Issues and Available Data) of the Soulhwestern U.S. Ground Motion Characterization (SWUS GMC) project. The PPRP wishes to thank the management team for the opportunity to participate in the workshop, which was held on March 19-21 in Oakland, California. The PPRP participated as observers, in order to be informed and lo provide a review of both the process and the technical developments. All four members of the PPRP (K. Campbell, B. Chiou, S. Day, and T. Rockwell) attended, and the panel observed all aspects of the workshop. The workshop was organized in a very professional and effective manner, and we appreciate the hospitality shown to us by lhe project team. Summary Comments The technical program was organized and conducted with the highest level of professionalism. As appropriate for the first workshop of a SSllAC Level 3 study, the focus was on framing the hazard issues, identifying available data, and identifying key data needs. The workshop began with a summary of the project, including clear statements of its objectives and scope. The SWUS GMC project inlerfaces with the lhree separate Seismic Source Characterization (SSC) studies supported by the respective sponsoring utilities. A series of presentations on the first day of the workshop outlined lhe principal seismic source issues for each sile, expressed in terms of hazard sensilivity. This introduction was very useful in setting the broader context for the GMC study and in enabling subsequent discussions to focus on data that arc most relevant to hazard. The resource-expert presentations that followed were well chosen, well structured, and comprehensive, and each included a list of references. All five members of lhe Technical Integration (TI) Team were fully engaged in the discussions of these presentations and each played a valuable role in interrogating the presenters. The PPRP is unaware of any relevant avenues that were not explored. The Tl Team did a commendable job of keeping the workshop focus on the data issues, as is appropriate for the first workshop of a SSllAC Level 3 study. Maintaining the right focus was challenging, because the line between data and interprelalions or models is nol a sharp one, but the team found the right balance. A clear separation of roles was mainlained. For example, when occasionally a TI or PPRP Team member was required to comment in the role of a resource expert, that role was always clearly stated. In summary, with respect to process, as well as with respect to technical quality and completeness, lhe workshop met all standards for a SSHAC Level 3 data workshop. A good foundation has been set for the exploration of proponent models in Workshop No. 2. Specific comments and recommendations are given below. Those specific comments, suggestions, or recommendations that require a written response are underlined. Recommendations 1. Site Kappa and Single-Station Sigma Terminology. Several resource experts presented very interesting and insightful information on the data needed to estimate the site attenuation parameter kappa and the ground motion standard deviation parameter site sigma. However, this material is quite technical and some of it is quite new. Not all parlicipanls and observers seemed lo have a shared underslanding of the terminologies being employed or how the estimated quantities can be applied in a self-consistent manner at each of the nuclear power plant sites where they wil1 be used. Our concern comes partly from the lack of probing questions of the kappa and single-site sigma resource experts from the TI Team, partly from a lack of significant questions from the audience, and partly from questions expressed by members of the PPRP. Therefore, the PPRP suggests that the Tl Team write White Papers, i.e., authoritative technical notes, on site kappa and single-station sigma, respectively, that define the terms, indicate how they are going lo be estimaled, and how they are to be used in the seismic hazard analysis of each of the NPPs. These documents would provide a common language and reference frame for future discussions and help allay concerns about possible double counting or other inconsistencies in lhese two parameters. 2. Splay Fault Modeling. The workshop included some discussion of dynamic rupture modeling of splay faulting, especially models leading to possible concurrent rupture of the Hosgri and Shoreline faults. Our understanding is that SCEC has been tasked with performing such modeling. We are concerned that this effort may not be as well interfaced with the relevant SSllAC projects (the DCPP and SONGS SSC studies and the SWUS GMC study) as it could be. In particular, the occurrence and extent of concurrent rupture on a splay depends quile slrongly on the orientation of the maximum principal stress direction. It is likely also to be sensitive lo rupture velocity. The SCEC team tasked for this work has been principa11y focused on canonical test problems for the purpose of code verification; it should not simply be assumed that the SCEC group has sufficient expertise and experience in the specific rupture dynamics questions being posed by the SSHAC projects to operate independenlly. The presentation al the workshop did not suggest that the SCEC team recognizes the importance of the principal stress orientations, nor the importance of exploring conditions conducive to a range of rupture velocities. We recommend that the SWUS GMC project and the other relevant SSHAC projects devise a plan to provide ongoing guidance and foedback to the SCEC modeling team.

3. DCPP-SSC inte1face issue: Slab Earthquakes. During the workshop, the possibility of earthquakes within a relic subducted slab beneath DCPP was broached during the presentation overviewing the DCPP SSC project. To our knowledge, this possibility of slab sources had not been mentioned at previous DCPP SSC workshops, and from the discussion at the workshop, it was not clear which project takes responsibility for assessing its technical defensibility and implications. Slab earthquakes arc known to excite ground motion with systematically distinct characteristics relative to crustal sources. We recommend that the two projects clarify the lines of responsibility and establish effective communication on this subject so that the Tl Team is not taken by surprise if slab events arc characterized in the DCPP SSC. 4. DCPP-SSC and SONGS-SSC intef:face issue: Afaximum depth qf' rupture in crustal earthquakes. During the DCPP-SSC overview presented at the workshop, the possibility was raised of deep rnpturc penetration, i.e., rnpture extending to greater than I 5-20 km depth, on some crustal faults in California. The SWUS-GMC TI Team seemed unaware that this was a possibility in the DCPP SSC project and it was not clear to us which project takes responsibility for the technical assessment of deep rnpturc. Furthcnnorc, although this issue was not raised in the SONGS-SSC overview, similar depth-of-rnpturc considerations may pertain to both California sites. We recommend that the SWUS-GMC project work with the DCPP-SSC and SONGS-SSC projects, respectively, to clarify ownership of the depth-of-rupture problem and begin to communicate effectively and regularly about the status and implications of those ideas. 5. Path-Spec(/ic Attenuation.for Palo Verde. The attenuation of ground motion between distant earthquakes and PVNPS may be quite strongly dependent upon the source location and might not be well represented by a single function of distance. The Tl Team clearly recognizes this likelihood and has taken it into consideration in their plan to empirically estimate attenuation from distant sources to PVNPS using existing recordings from relevant source regions. We consider this a sound approach. llowcver, the PPRP would suggest that the empirical approach be carefully applied in the light of a geological understanding of both the source and path regions (for example, it might be observed that paths crossing the Salton Trough are highly attenuative and geologic understanding might dictate that the same empirical correction not be applied to nearby sources that do not cross that province). 6. Iland-o.fl to Site-Spec(/ic Site-Response Team. The GMC TI Team is proposing to characterize ground motions for a common reference rock condition with Ys'.lo = 760 m/s and to adjust the base case GMC model to incorporate utility-specific differences in site characteristics and modeling approach. We understand that each utility will adjust the resulting rock hazards to the local site condition at each NPP site when deriving the I lazard-Consistcnt Ground Motion Response Spectra (GMRS). The Tl Team have acknowledged the need for interaction between these two efforts and emphasized the importance of proper handoff of the GMC model to the team responsible for specific site-response analysis. Still, we want to further emphasize it here by cautioning that lack of clarity and precision in the communication between the GMC Tl Team and lhe site response analysis team may make both vulnerable to misunderstandings and claims of inconsistency or double counting of effects. We recommend that the TI Team and the individual site projects collaborate to generate as soon as possible a reference document that describes the respective a(ljustments and procedures to be used at each site, and thal explains the technical rationale in each case. As with the documenls on kappa and single-site sigma recommended in Item I above, such a document would serve to guide future discussions, prevent misunderstandings, and ensure that no relevant data or models are neglected due to uncertainties about which project is responsible. Please feel free to contact us if you would like to discuss further our comments or recommendations. Sincerely, Steven M. Day Chair, PPRP Brian Chiou Member, PPRP Kenneth Campbell Member, PPRP I , f // /-* .. *'" Thomas Rockwell Member, PPRP December 3, 2013 Carola Di Alessandro, Ph.D. Project Manager for the SWUS GMC Project GeoPentech, Inc. 525 N. Cabrillo Park Drive, Suite 280 Santa Ana, CA 92701

Dear Dr. Di Alessandro:

This letter comprises the comments of the Participatory Peer Review Panel (PPRP) on Workshop #2 (Proponent Models and Alternative Interpretations) of the Southwestern U.S. Ground Motion Characterization (SWUS GMC) project. Workshop #2 was held on October 22-24, 2013, in Berkeley, California. The PPRP participated as observers, to monitor the progress of the SWUS GMC project and provide a review of both the process and the technical developments. All four members of the PPRP (K. Campbell, B. Chiou, S. Day, and T. Rockwell) were present for the full workshop and observed all workshop sessions. The panel also met at regular intervals during the workshop to assess its effectiveness in probing the proponent models and in adhering to SSI IAC Level 3 procedural guidelines. The workshop was very well planned and conducted. We appreciate the organizational efforts of the Project Management team, and, in particular their hospitality and attention to our requirements as a review panel. The location and facilities were excellent, and most proponent and resource experts were able to participate for the full three days. The presence throughout the workshop of a critical mass of experts resulted in very focused and thorough discussion of proponent models, key technical issues, and progress on ongoing studies. Summary Comments The technical program was very well prepared by the Technical Integration (TI) team to address appropriate Workshop #2 goals in depth. Those goals are to present, discuss, and debate alternative technical viewpoints, identify alternative hypotheses and their uncertainties, and provide a basis for development of hazard models that consider the full range of alternative technically defensible interpretations. The team made this large task tractable within the confines of a three-day workshop through several devices that maintained focus without sacrificing depth and completeness of the discussions. First, the workshop began with a series of hazard sensitivity presentations that were well designed to provide workshop participants a shared understanding of the key issues. These presentations were very effective in directing subsequent discussions. Second, the TI team prepared well thought-out questions for each proponent expert and submitted these to the experts in advance. Those questions provided good direction to the presenters and guidance to the discussions. At the same time, the format was kept open enough to ensure that potentially relevant issues, concerns, and models not anticipated by the TI team could be proposed and explored, and several such examples received valuable discussion. 1 Each resource-expert or proponent-expert presentation was well chosen and each provided thorough coverage of a relevant study or model and included a list of references. The TI team interrogated all presenters effectively and led general discussions that successfully engaged the wider audience of ground motion experts. As we nole in our recommendations below, most of the questioning during the first part of the workshop came from just a few of the Tl team members. The PPRP encouraged all five members of the TI Team to bring their voices to bear in this process, and by the end of the workshop we were pleased to see progress toward a more balanced engagement of all team members. The overall process was successful in revealing the strengths, weaknesses, and uncertainties of the competing models, and, except as noted in the recommendations listed below, Lhe PPRP is unaware of relevanl issues that were not explored. With respect to adherence to procedural guidelines, as well as with respect to technical quality, the workshop confom1ed well to standards for a SSllAC Level 3 workshop on alternative models and interpretations. There are some remaining issues of completeness Lhat should be considered prior to Workshop #3, and these are noted, along wilh other issues to consider, in the comments and recommendations below. Those specific comments or recommendations that require a written response arc underlined. Recommendations I. Bala11ced participatio11 by the Tl team members. During the first two days of the workshop, a disproportionate amount of the interrogation of the proponent experts was done by Lhe TI lead, with some conlributions from other senior members of the team. Other members were not significantly engaged in the discussions on those days. This imbalance is a concern, because SSI IAC guidelines for a Level 3 study explicitly call for TI Leam members to be prepared Lo voice independent views and technical challenges. The PPRP was pleased to see more balanced participation on the third day and recommends that the Tl team take concrete steps to ensure that this progress continues during the remainder of the project. The importance of full TI team participation is emphasized in the NRC SSHAC guidance document (NUREG-2117), which states, for example (p. 36) "membership in the Tl team automatically implies sharing the ownership qf the component models developed by that team," and (p. 38), while discussing the distinction of a Level 3 SSI IAC study in contrast to lower level SSI IAC studies, "The Tl must now be a team rather than an individual or small group .... at Level 3. this is essential both because no individual has the breadth o,/expertise required and because o.l the necessityfor technical challenge and defense among the evaluators. " 2. Selecti<m criteria and dedsion date for G1°"1PEs. Some of the ground motion prediction equations (GMPEs) presented and discussed al the workshop appeared to the PPRP to be at a less mature stage of development than the others. For example, one has not yet been fully described and documented in a formal publication. We recommend that the TI team formulate and document, as soon as possible, dear criteria to be employed to detennine which GMPEs will be used in hazard model developmenl, and thal documentation of the acceptance criteria include a justification, and that it specify a firm 2 cutoff date for achievement of the criteria, based on a realistic assessment of schedule requirements. The selection criteria should be applied on a consistent basis to all candidate GMPEs. 3. Completeness of proponent-model analysis in Workshop #1. The project team made a thorough effort to identify, select, and invite proponents of alternative interpretations. Not all invited proponents were able to attend the workshop. In the absence of a proponent to support the GMPE and magnitude-scaling recommendations of Dr. Zhao and his colleagues, their viewpoints on magnitude scaling of ground motion were solicited and presented by the TI Team; therefore an opportunity existed at the workshop to discuss and challenge them. This approach was fully consistent with guidance in the NRC SSHAC guidance document (NUREG-2117) (p. 70), which states, for example: "Because not all proponents ql alternative viewpoints may be able to attend the workshop, interpretations made by individuals who may not be present should be ident{fied and discussed." On the other hand, Dr. Idriss (author of the Idriss NGA-West2 GMPE) and Ors. Atkinson and Assatourians (developers of the finite-fault stochastic simulation method, EXSIM) also were absent, yet no representatives were designated to represent their models. As a result, discussion and debate of the merits of these two models were largely incomplete. The PPRP recommends that the TI team make an additional effort to complete the evaluation of these two proponent models at a level equal to that of the other models being evaluated. It should take place before the development of preliminary hazard models, and in a setting consistent with NUREG 2117, which stipulates (p. 39) that in a Level 3 study, the interactions with proponent experts should be "conducted openly in the presence qlobservers including the PPRP." 4. Completion of Workshop #2 objectives. The PPRP noted that there were many ongoing tasks that could not be evaluated in Workshop #2 because they were either incomplete or had just begun. The TI lead pointed out during the workshop that these tasks will need to be fully discussed and evaluated in order for the TI team to obtain feedback from the resource and proponent experts to factor into their evaluation. The PPRP agrees that there is the need for an additional meeting with resource and proponent experts, including the PPRP as observers, to cover these ongoing and incomplete tasks. The PPRP emphasizes, moreover, that sufficient time should be allowed between such a meeting and Workshop #3 to enable the Tl Team to fully evaluate and discuss the feedback from the meeting and incorporate that feedback into the preliminary ground motion logic tree and the related sensitivity studies that will be presented and discussed in Workshop #3. This concept is embodied in the NRC SSHAC guidance document (NUREG-2 I 17) that states (p. 67) "Any new data collection activities should be ident(fied early in the project, evaluated for their potential impact on the hazard results and associated uncertainties, and completed in a timely manner .for use in the technical evaluations. this would mean that the activities should be completed prior to Workshop #3 on Feedback and certainly no later than the time that the models are .finalized; (p. 68) Each workshop has a 5pec(fic focus and goal, and each requires that particular work activities have been conducted prior to its occurrence a11d certain work activities will occur and (p. 73) "Following Workshop #2 and prior to Workshop #3 Feedback. multiple l*vorking meetings will be necessary to develop a 3 preliminary model that can be used for purposes o,f sensitivity to provide the necessa1yfeedback to the Tl Team." Tl Team should consider scheduling this additional meeting such that there is sufficient time between it and Workshop #3 to prepare and revise the preliminary ground motion logic tree and to perform related sensitivity studies. 5. Schedule a11d prioritization. Over the course of the workshop, numerous technical issues that arc currently under investigation were identified as requiring substantial further work before certain modeling procedures can be included in a hazard model. The PPRP is very pleased that the project has initiated important investigations that are likely to have a big impact over the longer tcnn, and the fact that some will not reach full practical implementation during this project is understandable and inevitable in an effort such as this one. As the TI lead noted, in the short term, incomplete resolution of these technical issues can be accommodated in the hazard model through appropriate expansion of epistemic uncertainty estimates. The PPRP urges, however, that the TI team reach a prompt decision on which efforts to prioritize for inclusion in the hazard model. That decision should consider hazard sensitivities, and should be made early enough to realistically account for project schedule requirements. For example, by Workshop #3, which is scheduled for March 2014, a preliminary hazard model should have sufficient maturity that the PPRP and others can meaningfully probe its technical basis and understand the manner in which it incorporates the views of the larger technical community. We also note that a preliminary report is due for PPRP review within just a couple of months following Workshop #3. Please feel free to contact us if you would like to discuss further our comments or recommendations. Sincerely, Steven M. Day Chair, PPRP Brian Chiou Member, PPRP Kenneth W. Campbell Member, PPRP * Thomas Rock well Member, PPRP 4 April 21, 2014 Carola Di Alessandro, Ph.D. Project Manager for the SWUS GMC Project GeoPentech, Inc. 525 N. Cabrillo Park Drive, Suite 280 Santa Ana, CA 92701

Dear Dr. Di Alessandro:

This letter comprises the comments of the Participatory Peer Review Panel (PPRP) for Workshop #3 of the Southwestern U.S. Ground Motion Characterization (SWUS GMC) project. Workshop #3 was held on March 10-12, 2014, in Berkeley, California. The PPRP observed both the process and the technical developments. Fo11owing the guidelines of NUREG-2117, the PPRP also actively participated in the discussion and questioning of the preliminary models. The four members of the PPRP (K. Campbell, B. Chiou, S. Day, and T. Rockwell) were present for the full workshop and observed all workshop sessions. The PPRP met at regular intervals during the workshop to assess its effectiveness in providing feedback to the model evaluators, as we11 as its adherence to SSI IAC Level 3 procedural guidelines. The PPRP congratulates the TI and Project Management teams for carrying out a very successful workshop in conformity with SSI IAC Level 3 guidelines. The Tl team organized the workshop fonnat and presentations effectively, and we appreciate the efforts they and the Project Management team made to provide the PPRP with ample opportunity to interrogate the presenters. Summary Comments The goals of Workshop #3 are (1) to present the preliminary models, with emphasis on how alternative interpretations and uncertainties have been incorporated, (2) present sensitivity analyses and hazard calculations that provide insight into the preliminary models, and (3) address questions, including those from the PPRP, to provide an understanding of the technical bases for the model components and weights, and the manner in which the center, body and range (CBR) of tcchnica11y defensible interpretations (TOI) have been included in the models. The Tl team designed a set of presentations and discussions that was very successful in describing and exploring the overall structure for the GMC model. This enabled the PPRP to gain a good understanding of how the model is being framed. Several components of the model are very advanced and innovative. The use of Sammon mapping to visualize relationships among ground motion predictions (and to compare them with data and numerical simulations) is an especially noteworthy development. Also noteworthy is the exploration of possible non-Gaussian upper tails lo ground motion distributions, and their incorporation into the characterization of aleatory uncertainty via a mixture of two Gaussian distributions. Likewise, non-ergodic aleatory uncertainty is being addressed with exceptional rigor in this project, and path-specific terms arc being developed and applied where available data permit. We commend the TI team on their continuing efforts to bring these technical advances to fruition. 1 With respect to adherence to procedural guidelines, as well as with respect lo technical quality, the workshop confcmncd well to standards for a SSI IAC Level 3 workshop on model feedback. The entire Tl team was fu11y engaged in presenting the model clements and addressing questions. The TI team and the project manager were attentive to the role of the PPRP. During the presentation and discussion of each model element, the TI team allocated sufficient time for the PPRP to ask detailed questions about the model fommlation, its technical justifications, the basis for incorporation or rejection of alternative models, and the manner in which uncertainty is characterized. The TI lead, Project Manager, and in some cases the TI Team members met with the PPRP at the end of each day of the workshop to obtain immediate feedback. A number of requests for program adjustments were made at these meetings, and the Tl team was fully responsive to al1 such requests. Parts of the model evaluation process arc stil1 in progress, and a complete preliminary model was not available at the time of the workshop. However, the presentations and discussions of the model framework and the key individual model elements were sufficient to enable the PPR P to provide substantial feedback to the Tl team. In the comments and recommendations below, we endorse the Tl team's plans to obtain further model feedback from the PPRP once a complete preliminary model is available. Comments and Recommendations (underlining indicates those requiring a written response) J. Do£*umentation. As noted in the summary comments, the ground motion model contains a number of advanced clements aimed at providing improved confidence that the CBR of the TOI is being captured. The scientific development and validation of these advanced clements has been driven in large part by this project. The technical bases for these elements appear to be sound, and they represent significant advances in hazard assessment. However, because they are tcchnica11y advanced and relatively complex, they will have to be carefully and fully documented in the project report. Careful and clear documentation of complex procedures and concepts (for example, the construction of a multidimensional GMPE space, its visualization via Sammon mapping, and its final characterization from representative points on that map, in light of disparate data sets and simulation results) may be critical to project success. The PPRP recommends that Tl team members pay close attention to the documentation of these advanced model elements to ensure that the final report is not only complete and scientifically sound, but also as transparent and persuasive as possible to the PPRP and a broader technical audience. 2. Site effects interface issue. During the workshop, it became clear that the project had not yet produced a comprehensive reference document describing the adjustments and procedures to be used to modify the reference ground motions for use al each site (i.e., at PVNGS and DCPP). The PPRP previously recommended that such a document be developed in a letter to the Project Manager dated April 21, 2013 (Recommendation #6) following Workshop #1, and this recommendation is repeated here. As noted previously, any lack of clarity and precision in the communication between the TI team and a site response analysis team may make both vulnerable to misunderstandings and claims of inconsistency or double counting of effects. A comprehensive written document would serve to guide discussions, prevent misunderstandings, and ensure that no relevant data or models are neglected due to confusion about which project is responsible for which elements of the ground motion model. 2

3. SSC interface issue. The workshop revealed some apparent gaps in coordinalion between lhe Tl team and the respective SSC Tl teams for the DCPP and PVNGS SSllAC Level 3 projects. For example, the Tl team appeared to be unaware of the inclusion of strike-slip sources in the local-source component of the SSC model for PVNGS, and only presented GMC models relevanl to nonnal faulting. As a second example, the TI team discussed the PVNGS sourcc component in tenns of random fault orientations, whereas the PVNGS SSC TI team wil1 provide preferred orientations in the final SSC model. A further concern is that the DCPP SSC model might include a large range of rakes on dipping faults, and some coordination between that project and the GMC project may be required to ensure that those sources are appropriately categorized for use in the GMC model (e.g., the treatment of oblique slip sources was not discussed by the TI team). The PPRP recommends that the Tl team improve coordination with the TI teams of each of the SSC projecls to ensure that the GMC approach is fully compalible with the respective SSC approaches, so that last-minute issues will not arise that could delay project completion. 4. Feedha£*k on a complete preliminary model. The workshop provided a very good exposition of lhe conceptual framework of the ground molion logic lrees to be employed, as well as their technical bases. In most cases, the specific branches were identified, and there was extensive technical questioning and discussion from the PPRP and other experts, meeting most of the workshop objeclives. Nonetheless, the model feedback process was not quile completed at Workshop #3, because a complete preliminary model populated with weights was not available to be interrogated by the PPRP at that time. As noted in NUREG 2117 (p. 71 ), "In the discussions of the preliminary models, the technical bases for the assessments and weights should be described to allow for a discussion of the implications and constraints provided by the available dala." The PPRP supports the TI team's preliminary decision to hold one or more briefing meetings to present a full preliminary model to the PPRP for feedback when it becomes available, in advance of their development of the final model. 5. Geologic consistency of models for ground motion simulation. The numerical simulation of specific sources at DCPP employed fault geometrical parameters (in particular, down-dip fault widths) that arc not consistent with the SSC model. The PPRP recognizes that this may be largely an artifact of the way the numerical models are parameterized, together with the understandable project requirement to hold that parameterization fixed in the form it had when the numerical models were calibrated and validated. The PPRP also recognizes that the principal application of the simulations to date has been to test methods for combining empirical relalionships so as to approximate special conditions not represented well in the database, such as the simultaneous rupture on a main fault and a secondary splay. In thal type of application, lhe PPRP agrees that the results may be insensitive to the precise simulation geometry relative to the SSC model. Ilowcver, the appearance of discordance between the simulation parameters and actual fault parameters developed by the DCPP SSC is a potential source of confusion. The PPRP recommends lhat project documenlalion give careful auention to any apparent inconsistency between the ground motion simulation parameters and the actual fault parameters developed by the DCPP SSC team. Where simulations arc used only to test methods for applying empirical methods to special situations, the TI team might evaluate whether to simply treat the simulated faults as represenlatives of generic faull lypes, rather than associaling lhem wilh specific faults from the SSC model. On the other hand, if simulated ground motions arc 3 employed more directly, it will be necessary to document with care their actual relationship to the SSC model. 6. Representation CBR of liypocenter location.ti. In the development of the model of additional standard deviation to account for rupture directivity, the TI team assumed a model of hypocenter locations in which strike-slip earthquake epicenters had a tendency to concentrate near the center of the rupture trace. The team cited empirical results of Mai and others in support of this assumption. However, other relevant data are available (e.g., global compilations such as that of McGuire et al. in BSSA, 2002, as well as data from detailed studies of individual earthquakes in California and elsewhere). If the form of the hypocenter distribution is significant to the conclusions of the directivity study, the PPRP recommends that the Tl team further evaluate the hypocenter distribution model to ensure adoption of a final version that adequately captures the CBR of the TDI. 7. Frequency shift of between-eve11t standard deviation. The Tl team showed at the workshop that, if not removed by smoothing (as was done by some NGA-West2 developers), the event standard deviation tau has a so-called "bump" at short periods that is not as visible in the within-earthquake standard deviation phi. The Tl team showed evidence from a simple stochastic analysis that this bump is likely due to systematic variability in site effects, presumably due to variability in kappa, that is being transferred to tau and should, therefore, be included as part of the within-earthquake variability. Based on this conclusion, the TI team has adopted as part of their logic tree a smoothed short-period tau model with no bump and instead is transferring this aleatory variability to the site-response model. One of the interesting features of the bump in tau, which is often described as being at O. l sec ( l 0 Hz), is that it occurs at a shorter period for small earthquakes than for large earthquakes and has a pronounced dip near 0.3-0.5 sec, which also changes with magnitude. The PPRP recommends that the Tl team seek an explanation of the apparent frequency shift of the bump and dip in tau with magnitude and assess whether it is consistent with the proposed hypothesis that these effocts represent variability in site effects rather than source effects. 8. Epistemic uncertainty iii median predictio11. The epistemic uncertainty in predicted median ground motion includes two components the within-GMPE uncertainty of estimated GMPE coefficients and the between-GMPE variability. At the workshop, the TI team's proposed approach for evaluating the latter component of uncertainty (via the construction of GMPE space) received substantial discussion and helpful feedback. There was, however, not as much discussion of the within-GMPE uncertainty. Since uncertainty in median motion is an important contributor to the uncertainty in calculated hazard, the PPRP recommends that both bet G M PE and within-GMPE components of epistemic uncertainty be evaluated with comparable rigor and that each be represented in the logic tree with an appropriate level of detail. A potential means to capture within-GMPE uncertainty in a manner comparable to the treatment of between-GMPE uncertainty was noted by the Tl lead during the workshop. The suggestion was that the within-GMPE covariance matrix of a training GMPE be used to generate more training GMPEs for the purpose of constructing GMPE space. The PPRP will be interested in any update of the TI team's views of this approach and any plans that they have to further evaluate it. 4 Please feel free to contact us if you would like to discuss further our comments or recommendations. Sincerely, Steven M. Day Chair, PPRP Brian Chiou Member, PPRP Kenneth W. Campbell Member, PPRP I , f // /-... * Thomas K. Rockwell Member, PPR 5 Decemberl3, 2014 Dr. Carola Di Alessandro SWUS Project Manager GeoPentech, Inc. 525 N. Cabril1o Park Drive, Suite 280 Santa Ana, CA 92701

Subject:

Participatory Peer Review Panel Letter No. I: Rev.O Report, Southwest United States Ground Motion Characterization Level 3 SSI IAC Project

Dear Dr. Di Alessandro:

This letter provides comments and recommendations of the Participatory Peer Review Panel (PPRP) for the SWUS Project Report, Rev.O. llerc we address Chapters 7, 10, 11, 12, and 13, and Appendices L, M, N, and R. We have not yet had the opportunity to lhoroughly review the remainder of the report, some of which is nol yet available to us at this time. It should be appreciated, therefore, that the portions of the report considered in this letter may be subject to further comment once the PPRP has reviewed the remainder of lhe report. The review comments arc tabulated by chapter and identified by section, page, paragraph, sentence or line number, and table or figure number where appropriate. Each comment is assigned a unique number for reference, and the table includes an additional column in which the responses of the TI T earn may be recorded. The review is not intended to be editorial, but we do cal1 attention to stylistic or grammatical concerns in instances where they substantia11y affect clarity or may introduce ambiguities. The Rev .0 report covers the full scope of the evaluation and integration efforts of the TI Team. The review comments from the PPRP arc intended to help the Tl Team clarify and expand as necessary the technical basis and justifications for the models and weights used in the final GMC logic trees. Sincerely, Steven M. Day Chair, PPRP Brian Chiou Member, PPRP Kenneth W. Campbell Member, PPRP I , f // /-* .. *'" Thomas K. Rockwell Member, PPRP Comment Response Table Comment Location in Text PPRP Comments Tl Team Responses Number 1. General comments The report lacks terminological and stylistic consistency. This deficiency affects its readability and sometimes renders meanings ambiguous. Just as examples: the report uses inconsistent abbreviations for the NGA West2. inconsistent symbols for some variables (e.g. tau.Tau. r). inconsistent names to refer to data sets. Please edit for overall consistency of style, terminology and notation throughout the report, including main chapters and appendices. 2. General comments Acronyms. technical terms, and individual variables are not consistently defined when they are first used. Please provide a list of acronyms. a list of variables. and a list of terms that the reader can refer to when needed. Please also define these acronyms, parameters, and terms the first time that they are used in the report, after which they need not be defined again as long as the reader can refer to a list as necessary. For example. ASK14. BSSA 14, CB 14, and CY14 are used throughout the report and are defined by their full references sometimes and only their acronyms at other times. Please provide the full references the first time they are used. include them in the list of acronyms, then only reference them by their acronyms after that. 3. General comments There is very inadequate cross-referencing between chapters and between the main chapters and the appendices. While there is no objection to putting technical detail in the appendices, each report chapter must be coherent and self-contained in and of itself in the sense that any appendices that it relies on must be incorporated by explicit references. with sufficient connective text to be readable and understandable. When results from such an appendix are referenced, please cite the relevant section and/or figure or table number within the appendix. 4. General comments Please consider streamlining the presentation by absorbing some of the short appendices with few figures. or that are redundant with other report chapters or appendices. into the appropriate main chapters. In that case, only those appendices that are lengthy, present complex methods or analysis, or contain a large number of figures or tables. could be retained as separate entities. 5. General comments There are many places throughout the report where there are statements of what was done but not why it was done. It is a requirement of the SSHAC process that the justification and basis for each decision by the Tl Team be fully documented Please provide a description of the Tl Team's assessment and evaluation that was done to arrive at the methods, models, and decisions that form the bases for the statements and models presented in the report and appendices. 6. General comments Because the 3-point discretization scheme for representing a continuous distribution was frequently used in the report. please provide a brief discussion of its origin. properties. and accuracy. so that that discussion can be used as a reference throughout the report.

7. General comments Please consider providing a special treatment of the scaled Chi-square distribution in the report. It is invoked frequently, and such a treatment could serve as a reference throughout the report, and also could make related chapters more accessible to the full range of readers As noted later in this review. the presentation of the topic in Chapter 13 is unmotivated, lacks clarity, and its equations are made impenetrable by numerous notational errors. 8. General comments The term proponent model" is used a number of times in the report in ways that seem to be inconsistent with the term's usual meaning in a SSHAC study. In the SSHAC context. the term is usually reserved for models presented by proponent experts. for subsequent evaluation by the Tl Team. In each instance, if the intended usage corresponds to the SSHAC standard, please ensure that it is clear why. If it does not, it is important to avoid the term. as it is misleading. 9. General comments It is appropriate to discuss the center. low and high values of variables when a model is first discussed. but please consider consistently deferring discussion of the weights to the chapter that discusses the related logic tree. The current draft is inconsistent in this regard. CHAPTER 7 GMC Models for the Sigma 10 Section 7 .1 , Page 7 -Please note that Anderson and Brune (1999) was cited but not included 1, Paragraph 1, Line 4 in the references section of this chapter 11. Section 7.1, Page 7-Please clarify that Cj)ss and <ps,,.R are alternative (mutually exclusive) 1, Paragraph 1, Line 6 models for PVNGS (associated with non-path-specific median and path-specific median models, respectively, and also please reference appropriate sections from chapter(s) on median motion. 12. Section 7. 1 , Page 7 -Please replace "!" with "and" to avoid any confusion that <Pss I <f'sP-R is a 1, Paragraph 1, Line 7 ratio of these two terms. 13. Section 7. 1 , Page 7 -For uniformity of coverage, please include in the outline in this section a 1, Paragraph 1, Line reference to chapter 13 where the combining and resam piing of tau and 8-9 phi is discussed. 14. Section 7 .1 , Page 7 -Please consider whether Miller and Rice (1983) is correctly cited here. 1, Paragraph 1, Line 9 Miller and Rice propose moment-preserving sampling of continuous distributions at Gaussian points. Is this reference relevant to the approach actually used in this report? 15. Section 7. 1 , Page 7 -It is not clear whether the term "sigma" is meant to represent a generic 1, Line 10 term for all standard deviations or to represent a specific standard deviation. Please define the term "sigma" the first time it is used and include it in the list of terms. 16. Section 7. 1 , Page 7 -It would be helpful to also give a guide here to the relevant appendices 1. End offirst covering sigma topics that are referenced in this chapter. Please note in paragraph particular that the division of the <pss and s"*" details between two different appendices (N and L, respectively) tends to obscure their close relationship, and any such confusion would be mitigated by an overview discussion of the sigma appendices at this point in the report. 17. Section 7 .1 . 1 , Page Please explain that the site-to-site variability that is removed in order to 7-1. 1st Paragraph of estimate single-station sigma needs to be included as uncertainty in the Section, Line 4 site-specific site-response analyses. whether they are empirical or analytical.

18. Section 7. 1 . 1 , Page Please include citable references to the PSHA studies mentioned in this 7-1. 1st Paragraph of sentence (PEGASOS Refinement Project. Thyspunt Nuclear Siting Section, Last Project. BC Hydro PSHA Project. and Hanford PSHA Project} sentence 19 Section 7 .1 . 1 , Page Please justify your criterion of using "a minimum of 3 recordings. Why is 7-2, First Paragraph, a higher number of recordings not needed (especially given the use of a Line 6 minimum of 5 recordings per station in the <llsP-R analysis for PVNGS described in Appendix L)? 20. Section 7 .2.1, Page Please define the term 'central value' (is it mean, median, or something 7-2, First paragraph, else?). Line 1 21. Section 7.2.1, Page Please cite appropriate references for ASK14, BSSA14, CB14 and 7-2, Paragraph 1, Line CY14, as well as for the errata of the Akkar et al. (2014) and Bindi et al. 2-3 (2014) papers. 22. Section 7 .2.1, Page Please explain whether there was an attempt to obtain the residuals or 7-2, Paragraph 1, Line databases, from which residuals could be calculated, for the Graizer 4 (2014) and Idriss (2014) GMPEs in order that estimates of phi and tau could be derived before these models were rejected. 23. Section 7 .2.1, Page Please provide a reference to the section where plots of the magnitude 7-2. Paragraph 1. Line distribution of the Akkar et al (2014) and Bindi et al. (2014) databases 5 are shown. 24. Section 7 .2.1, Page Regarding the expression "it was assessed." please indicate who did the 7-2, Paragraph 1, Line assessment (i.e., the Tl Team) in order to avoid confusion. Please also 9 ensure that similar references to the writers of the report are replaced with references to the Tl Team throughout the report and appendices. unless someone else did the assessment. in which case they should be clearly identified. Moreover, use of the word "may" implies that it is not known and not assessed. If such an assessment was done, please delete the word "may" to indicate that the Tl Team knows this to be the case. 25. Section 7 .2.1, Page Some studies have developed separate sigma and median models, in 7-2. Paragraph 1. Line which case the model-specific sigma model of each GMPE is not 9 important. Please explain why the Akkar et al (2014} and Bindi et al (2014) GMPEs were rejected on the basis of their sigma models and why the Tl Team decided to use model-specific sigma models instead of a sigma model that is independent of the median model. 26. Section 7.2.2.1, Page Introducing the term "bump" is stylistically questionable (as 7-2, Section title (and acknowledged by the use of quotes) and not as clear as simply calling general comment on the feature a peak (which is unambiguously a feature with a local section) maximum). and leads to inconsistency. as sometimes it is called a peak later in the report (e.g., first line of next paragraph). Please consider whether a more conventional term such as "peak" (without quotes), used consistently in the subsection heading and thereafter. would be suitable here. 27. Section 7 .2 2 1. Page Please explain why ASK14 and CY14 "chose to smooth through these 7-2. Paragraph 1. Line variations" in the period-dependence of tau. 7 28. Section 7.2.2.1, Page Please provide a citable reference to the point-source simulation 7-3. Paragraph 1. Line methodology used by Bob Youngs. Because this work forms the 1 theoretical justification for removing the peak in tau around 10 Hz. please consider adding a more in-depth description of this work either to this section or as an appendix.

29. Section 7.2.2.1, Page Please explain why the particular values of median stress parameter (50 7-3. Paragraph 1. Line bars) and its logarithmic standard deviation (0.5) were selected and why 2 the stress parameter is modeled with a lognormal distribution Please also indicate whether the results are sensitive to the selection of these particular values. 30 Section 7 .2 2 t. Page Please explain what logarithmic standard deviation is. 7-3, Paragraph 1, Line 3 31. Section 7.2.2.1, Page Please ensure that the term "site kappa" has been defined in the report 7-3, Paragraph 1, Line prior to its use in Chapter 7 and included in the list of terms. 4 32. Section 7.2.2.1, Page Please explain why the particular values of median site kappa (0.035 7-3. Paragraph 1. Line sec) and its logarithmic standard deviation (0.3) were selected and why 5 site kappa is modeled with a lognormal distribution Please also indicate whether the results are sensitive to the selection of these particular values. 33. Section 7.2.2.1, Page Please add text to explain what the "WUS amplification factor" is and 7-3, Paragraph 1, Line what effect it is supposed to model (also ensure that the acronym WUS 5 has been defined when it is first used and included in the list of acronvms). 34 Section 7.2.2. t. Page This sentence implies that the site amplification from the Boore and 7-3, Paragraph 1, Line Joyner (1997) site profile is frequency independent; whereas, it is highly 5-7 frequency dependent. Please clarify whether ii is the site factor itself or the variability in this site factor that is frequency-independent. Please explain why the particular values for median site amplification variability (0) and its logarithmic standard deviation (0.4) were selected and why site amplification is modeled with a lognormal distribution. 35 Section 7 .2 2 1. Page Please describe how you obtain the residual standard deviations from 7-3. Paragraph simulation data. 1, Line 7 36. Section 7.2.2.1, Page Please also state that this methodology does not explain the "dip" in tau 7-3. Paragraph at around T = 0.4 sec. t. Line 8 37. Section 7.2.2.1, Page Please describe the frequency-dependent site factor that was used. 7-3, Paragraph 1. Line 9 38. Section 7.2.2.1, Page Please consider providing a clear statement of what variable was 7-3, Paragraph 2, Line correlated with kappa, and how this correlation was determined, in the t 2nd set of simulations. 39. Section 7.2.2.1, Page Please consider whether the phrase "tau is a measure of the average 7-3, Paragraph differences in ground motion from earthquake to earthquake" should be 2. Line 4 more precisely formulated to reflect the fact that tau is a parameter that measures the dispersion of deviation (from average). 40. Section 7.2.2.1, Page Please revise this sentence to make it clear that the total variance in 7-3. Paragraph kappa is partitioned into two components: the event-to-event variation of 2. Line 7 median site kappa of an event and the within-event variation of site kappa at 50 sites. 41. Section 7.2.2. t. Page Please clarify whether you mean "average" or "median". 7-3. Paragraph 2. Line 11

42. Section 7.2.2.2, Page Please rewrite paragraph for greater precision and clarity. The first two 7-4. Paragraph 1. sentences of this section read as though the previous section of the Lines 1 and 2 report was not there. Furthermore. they are imprecise. NGA-West2 analyses (not models) found the tau peak cited. The second sentence can be read as implying that the NGA-West2 studies attributed the peak to the kappa correlation. which they did not. 43 Section 7.222. Page Please provide a reference to the section where the removal of the 10 7-4, Paragraph 1, Line Hz peak is discussed and the outcome presented. 3 44. Section 7.222. Page Please further articulate this recommendation to include, for example. 7-4. Paragraph 1. Line how site response should be conducted in order to be consistent with the 4 decision to remove the 10 Hz peak. 45 Section 7.2 3, Page Please use consistent language throughout the report and appendices to 7-4. Paragraph 1. 2nd refer to the set of GMPEs selected for the tau study (currently they are and 3rd Lines: called, e.g., "considered models," "five considered GMPEs," "the 5 GMPEs," "the underlying five models" elsewhere in Chapter 7). 46 Section 7.2 3, Page The cited figures. 7.2.3-2 and 7.2.3-3, are missing. 7-4, second to last line of section 47. Section 7.24, Page The word "significantly represents a subjective judgment by the Tl 7-5. Paragraph 2. 2nd Team. Please replace "significantly" with a more quantitative description Line of the change of tau with period and discuss why 1his change is not considered to be significant. 48 Section 7.2 5, Page On the right hand side. the subscript "w" is incorrectly included 7-5, First Paragraph of section, Equation 7.2.5-1 49. Section 7.2.5, Page Please justify why the within-model variability of tau from CY14 can be 7-5, 1st Paragraph of considered representative of the other four selected models. Also Section, 2nd provide a citable reference to the result from Bob Youngs referred to Sentence here, if one is available. Otherwise provide documentation of that analysis and its results in the chapter or an appendix. 50. Section 7.2.5, Page The phrase "smoothed using a constant across all periods" is misleading 7-5, Paragraph 1 of if the intent was that the average over all periods was done to produce a section. 5th line after period-independent model. Please clarify. eqn 7.2 5-1 51 Section 7.2 5, Page The averaging process doesn't "account" for the stated fact, but rather 7-5. Paragraph 1. Line makes it irrelevant, since the Tl Team elected to use a period-6 after eqn 7.2.5-1 independent model. Please clarify this point. 52. Section 7.2.5, Page Please provide text to explain clearly why the distribution is "scaled", 7-5, Paragraph 2, Line how the scale factor c and degree of freedom k are derived (e.g., are 5 they set to obtain a simultaneous match to mean and variance of tau squared?), and why this distribution is appropriate for modeling the uncertainty in tau squared. 53 Section 7.2 5, Page Please describe what value of tau squared should be entered into the 7-5, Paragraph 2, equations for c and k. This special value of tau characterizing the Second to Last Line distribution should be given a distinct notation to differentiate it from the random variable tau whose distribution is being characterized.

54. Section 7.2.5, Page Please provide additional justification and basis for the magnitude-7-6. Paragraph 1. dependent tau model shown in Figure 7.2.5-5 Sentence 3 55 Section 7 .3.1, Page The hazard sensitivity studies from elsewhere in the report that support 7-6, Paragraph 1, the specific magnitude and distance ranges selected as "important" for Lines 4-5 DCPP should be referenced here, with section and figure numbers cited. Please also provide a more quantitative description of what is meant by "important". since this term represents a subjective judgment of the Tl Team. 56 Section 7 .3.1, Page Please rewrite this sentence to clarify its meaning. and also provide a 7-6, Paragraph 1, reference for the results cited from an external project. Final sentence 57 Section 7 .3.1, Page Please add references to parts of the report where results of the Tl 7-6, Paragraph 2 Team's evaluations are presented (including a reference to a figure supporting the statement that "the calculated <Pss values were consistent among the 4 NGA-West2 models"). 58. Section 7 .3.1, Page Please add precise references to the report and/or appendix section(s) 7-6, Paragraph 3 of where the coefficient of variation estimate of 0.12 is derived (for section. Line 4-7 example. "Appendix M. Section M.3 and Figure M.7"). where use of chi-squared distribution of <Pss is explained and justified. and where the details of model derivation and assessment are available. The general catchall referral to Appendix M in the last sentence of the paragraph is insufficient in this regard. 59. Section 7 .3.1, Page Regarding the statement that " ... values were smoothed over period; 7-7. Paragraph 2 on please clarify nature of smoothing or provide reference to section of page. Line 1 report that does so. 60. Section 7 .3.1, Page Please provide the justification and basis for the proposed high and low 7-7, Last paragraph of values of <Pss and provide missing Table 7.3.1-3. section. last sentence 61. Section 7 .3.1.1, Page Please add text to describe the findings regarding dependence on 7-7, Paragraph 1, Line distance, style-of-faulting, and Vs30. Please also add text (here or in 1 Chapters 11 and 12} to justify the Tl Team's decision to not model such dependence in the logic tree for sigma. 62. Section 7.3.1.1, Page A reference to Workshop 3 (Appendix G) is not sufficient. If this work 7-7, Paragraph 1, Line was done outside the SWUS project, please provide references to 2 publications or peer-reviewed reports. If this work was done within the SWUS project. then please add more documentation or cite sections of the report where such documentation is included. 63 Section 7.3.1.1. Page Please also summarize where in Chapter 7 the models for <Pss and their 7-7, Paragraph 2 coefficients can be found. 64 Section 7 .3.1.1. Page Please further justify the inclusion of the magnitude-independent <pss 7-7. Paragraph 2 branch (with the CA data set) in light of the clearly observed magnitude-dependence shown in Figure M.4. 65 Section 7.3.2, Page The part of the sentence after the comma that starts with "a subsets of 7-7, 1st Paragraph of the single-station" seems to be disconnected from the first part of the Section, 2nd sentence. Please restructure this sentence to clarify its meaning. Sentence 66. Section 7.3.2, Page Please indicate that Figure 7.3.2-1 shows <Pss values for the European 7-7. 2nd Paragraph of dataset. which is not obvious from the text Section, 1st Sentence

67. Section 7.3.2, Page Please provide reference to specific section(s) or appendices of the 7-8. 1*' paragraph on report where this figure for COV(q>ss) is derived. including explanation page. Line 2-4 on and justification of the method based on chi-square distribution page 68. Section 7.3.2, Page Please explain why data for only five spectral periods are shown in 7-8, 1" paragraph on Figure 7.3.2-2. page. Line 4 69 Section 7 .3 2 1. Page Please explain why the CA dataset was not used to develop a 7-8, 1st Paragraph of magnitude-dependent model for PVNGS as it was for DCPP. Section, 1st Sentence 70. Section 7.3 3, Page Please provide further explanation and basis of the statement "No data 7-8. 2nd Paragraph of in the distance range of 200 to 400 km is available in the CB14 dataset". Section, 1st Sentence CB 14 did use data from distances of 80-500 km to fit average anelastic attenuation terms, but did not include these data in the derivation of event terms and within-event standard deviations. 71. Section 7.3.3, Page Please provide reference to specific section(s) or appendices of the 7-8, 3rd Paragraph of report where this figure for COV(q>ss) is derived, including explanation Section, 2nd and justification of the method based on chi-square distribution Sentence 72. Section 7.3.3, Page Please consider deferring any discussion of logic-tree weights and their 7-9 1st Paragraph. 1st justification until the report sections that present the logic-trees. Other Line parts of Chapter 7 present the models and their uncertainty and not the assessment of logic-tree branch weights, which requires additional justification; so introduction of weights in this section appears somewhat inconsistent with the rest of the chapter. 73 Section 7 .4.1, Page Please explain why all four NGA-West2 GMPEs can be used for the 7-9 1st Paragraph of assessment of q>sP-R. whereas CB14 was excluded from the assessment Section, 1st sentence of <Pss. 74. Section 7.4.1, Page Please justify why only three spectral periods are sufficient to define the 7-9 1st Paragraph of period-dependence of single-path term <p:;p.I{, given that the observed Section, 2nd dependence of this standard deviation for other spectral periods might Sentence deviate from that shown in Figure 7 .4. 1-1. 75. Section 7 .4. 1, Page Please provide a discussion of why the 0.2 s result is unstable. 7-9. 1st Paragraph of Section, 3*d sentence 76 Section 7 .4.1, Page Please provide justification for the use of a chi-square distribution and 7-9 1st Paragraph of provide a reference to this distribution and the related equations. Please Section, 4rd Sentence also provide a reference (i.e., the section in Appendix M) for the selection of a COV of 0.17; the explanation in the 4th Sentence requires additional *ustification. 77. Section 7 .4.1, Page The related materials provided in Appendix Lare little more than a 7-9, 1st Paragraph of repeat of these sentences. The required technical details and basis for Section, 4:* sentence the proposed models for ills*-K are lacking. Please provide sufficient and remainder of documentation so report satisfies SSHAC Level 3's requirement of being paragraph clear. transparent. and complete. Any references to the appendix should be specific with respect to sections, tables, figures. 78. Section 7.5, Page 7-In addition to presenting the comparison, please discuss the important 9, Paragraph 1 findings and how they agree (or disagree) with the logic-tree models proposed by the the Tl T earn

79. Section 7.5, Page 7-Please supply a reference for the Hanford project magnitude-dependent 9. Paragraph 1. Line 8 <pss-80. References, Page 7-Please update Abrahamson et al. (2014) with journal volume and pages. 10, Item 3 81. References, Page 7 -Please add reference for published erratum to Akkar et al. (2014) and 10, Item 4 cite both original paper and erratum in text. 82. References, Page 7-Ang and Tang (2007) is not cited in text. Please remove from references 10, Item 7 unless a citation is added to text. If ii is cited, please cite by page number. and also include publisher location in the reference section entry. 83 References. Page 7-Please include an additional reference to the published erratum to Bindi 10, Item 9 et al. (2014) and cite both references in the text. 84. References, Page 7-Please update the Boore et al. (2014) and Campbell and Bozorgnia 10, Items 11 and 12 (2014) references to include the specific journal volume and pages. 85 References. Page 7-Please update the Chiou and Youngs (2014} reference to include the 10, Item 14 specific journal volume and pages. 86 References. Page 7-Please provide the page numbers or paper number for the Graizer 11, Item 1 (2013) reference. 87. References, Page 7-Please update the Idriss (2014) reference to include the specific journal 11, Item 2 volume and pages. 88 References. Page 7-Please list the publisher's name and location for the Rodriguez-Marek 11 and Cotton (2011) reference 89 Tables 7.3.1-1. 7.3.1-These three tables are missing 2. and 7.3.1-3 90. Figures 7.2.3-2 and These figures are missing. 7.2.3-3 91. Figure 7.3.2-3, Page Please indicate in the caption which panel is PGA and which is 1s PSA 7-33 (the panel headers do this. but the information needs to be clearer. especially as the header uses T0.000 while the caption refers to PGA) 92. Figure 7.5-5 Please replace"/" with "and" so that the term "hisslPhisp.f<" will not be confused as being a ratio. Also note that the figure is mislabeled (as 7.5-6) 93. Figure 7.5-7 To maintain consistency, please describe the three Italian datasets referred to as "Italy, PhiSS1 -Italy, PhiSS2 -ltaly-PhiSS3" in the text. CHAPTER 10 Tau Model Logic Tree for Both DCPP and PVNGS 94. General The chapter is tersely written, often with insufficient background information provided, and insufficiently thorough documentation of the logic tree and the assessment and evaluation that went into determining its branches and weights. Please ensure that the chapter is self-contained, with an adequate summary that references back to Chapter 7 (sigma overview chapter), and other chapters and appendices as needed.

95. Section 10.0 This paragraph has little substance. Please consider providing a somewhat more complete outline of the chapter. 96 Section 10.1. Page Please point out the meaning of red versus green coding of the weights 10-1, Paragraph 1, in Figure 10-1 (and in the caption of that figure) Line 2 97. Section 10.1, Page Please list or provide a reference to the parameter values of the scaled 10-1. Paragraph 1. Chi-square distribution that were used to compute the quantiles. Also. Line 2 please confirm that it is the mean. not the 50th percentile. that was used for the central branch. 98. Section 10.2, Page Please consider replacing "observations" with "assessment" to indicate 10-1, 1st Paragraph of that at this stage of the evaluation and integration that the Tl Team has Section, 2nd Line made its assessments of the proposed model. 99. Section 10.2, Page Please reference the appropriate sections of the chapter or appendix 10-1 , Item No. 1 where the hazard sensitivity analysis is presented that justifies the specified magnitude and distances ranges of interest. 100. Section 10.2, Page Please also cite the published errata to Akkar et al. (2014) and Bindi et 10-1, Item No. 2, 1st al. (2014) and include these errata in the list of references. Line 101. Section 10.2. Page The statement that 'The Zhao et al. (2006) magnitude-independent 10-1, Item No. 2, Last proponent 1 model is judged to be applicable because their database is Sentence almost entirely composed of recordings from earthquakes with M 2 5" could be understood to be a counter argument to the adoption of a weight of 1.0 for the magnitude-dependent tau model mentioned in the beginning of this section. Please explain how the magnitude-independent tau model of Zhao et al. (2006) was incorporated into the magnitude-dependent tau model or remove this statement and discuss it later in the text. 102. Section 10.2, Page Please either provide the full references to the acronyms BSSA 14, 10-1. Item No. 3, 3rd CB14. CY14. and ASK14 the first time they are mentioned in Chapter 10 and 4th Lines or ensure that they are defined the first time they are mentioned in the report and that they are included in the list of acronyms. 103. Section 10.2, Page Please explain why it is proper to use the word proponent" in this 10-2, Paragraph 1. sentence. Line 4 104. Section 10.3, Page Please avoid using the word "assuming" in this context, but rather 10-2, 1st Paragraph of replace it with a phrase that indicates that the logic-tree branches were Section, 1st Line developed by evaluating and assessing available data and results. referencing other sections of the report for supporting analysis if appropriate. 105. Section 10.3, Page Please provide a reference to sectionsfpages in Chapter 7 where the 10-2, Sentence 2 evaluation of 012 is described. 106. Section 10.3. Page Please either provide a reference that supports the specified 10-2. Sentence 2 approximation of a three-point discretization of a chi-square distribution, including the specified weights, or explain the evaluation and basis for this approximation. 107. Section 10.3. Page In light of the discussions in Section 13.2. please clarify if the central. 10-2, general low. and high 't branches described in this section are directly used in comment on section the Hazard Input. If not, please explain the reasons for having this section.

108. Section 10.4, A large number of references contained in this section are not cited by References this chapter. Please clean up the reference list. 109. Figure 10-1. Page 10-Please add an explanation of the color scheme for the branch weights. 4 110. Figure 10-2, Page 10-Please modify Figure 10-2 to show the final magnitude-dependent tau 5 model without all of the various models that were used to derive it and explain that this model is independent of frequency (the figure. being for T = 1 sec, implies that the model might be frequency-dependent). The other models shown in this figure were evaluated in a previous chapter and need not be included in the final logic-tree model. CHAPTER 11 Phi Model Logic Tree: DCPP 111. Title Please add a subscript 'SS' to 'PHI' 112. General The chapter is tersely written. often with insufficient background information provided. and insufficiently thorough documentation of the logic tree and the assessment and evaluation that went into determining its branches and weights. Please ensure that the chapter is self-contained, with an adequate summary that references back to Chapter 7 (sigma overview chapter). and other chapters and appendices as needed. 113. Section 11.1. Page Although the analysis of the aleatory variability is performed on the 11-1, 2nd Paragraph within-event residuals, the distribution is on Phbs. Please remove of Section, 5th "residual" to indicate that the distribution is for Phiss. Sentence 114. Section 11. 1 , Page Please clarify if the phrase involving "aleatory variability" is consistent 11-1, Paragraph 2, with the 'Epistemic Uncertainty' branch heading on Figure 11-1 . Line 6 115. Section 11.2. Page Please provide references for the acronyms ASK14, BSSA14, CB14, 11-1, 1st Paragraph of and CY14 the first time they are mentioned in Chapter 11 or ensure that Section, 3rd Line they are defined the first time they are mentioned in the report and i in *h= I id nf 116. Section 11.3, Page Please further justify the assignment of equal (0.5) weight to the 11-2, Paragraph 1. magnitude-independent branch even though Figure M.4 suggests a clear Line 2 magnitude dependence in the California subset. Appendix references should be specific. citing sections, pages. tables. and/or figures. 117. Section 11.3. Page Please provide a clear reference to where in Appendix M the absence of 11-2. Paragraph 2, M-independence in the global dataset is illustrated. Line 1-2 118. Section 11.4, Page This explanation is pretty cryptic until one studies Appendix M. Please 11-2. Paragraph 2. consider whether clarity would be improved by an explicit statement that Sentences 1 and 2 the sampling distribution of <pss at each site adds an upward bias on top of the true site-to-site variability of Also consider whether the second sentence would be more precisely rendered if removed the bias using" were replaced by "the bias was estimated assuming a chi-squared sampling distribution of Qlss 2 ", with reference to the place in the report where this assumption is justified. 119. Section 11.4. Page Coefficient of variation is abbreviated as CV here. but COV elsewhere. 11-2. Paragraph 2. Please make the notation consistent throughout the report. Sentences 3 and 4 120. Section 11.4, Page The assessment of the low and higher values of <Pss.s was not well 11-2. 2nd Paragraph documented in Appendix Mand in Chapter 7 (see previous comments). of Section. Last Therefore. the statement that "high and low epistemic uncertainty Sentence branches are computed corresponding to the 5th and 95th percentile of <llss.s .. does not have a well-documented basis at this point in the report. Also. the use of present tense infers that the calculations are discussed and included in Chapter 11 rather than in a previous chapter. Please revise Appendix M and Chapter 7 to fully support the assessment that the high and low values of 'Pss.s can be represented as the 5th and 95th percentiles of the epistemic distribution. 121. Section 11.4, Page Please provide the mathematical basis for characterizing the central. 5th, 11-2. 3rd Paragraph and 95th percentile values with weights of 0.6, 0.2. and 0.2. respectively. of Section Please also be more specific when referring to the "central" value as being the median, mean, or another statistical value of the distribution. 122. Section 1.5, Page 11-Please provide a reference to the section (and pages. tables. and/or 3. Paragraph 1. Line 2 figures. if appropriate) where directivity adjustment of <pss is discussed. 123. Section 11.6. Page Please provide a brief description and reference of the "quantile plot (Q-11-3, 1st Paragraph of Q plot)" for clarity. Section, 3rd Line 124. Section 11.6. Page Please define what epsilon is the first time it is mentioned in Chapter 11. 11-3, Paragraph 1. or ensure that ii is defined the first time it is mentioned in the report and Line 4 that it is included in the list of terms. 125. Section 11.6. Page Because the concept of a mixture model is relatively new. all available 11-3, 2nd Paragraph sets of GMPE within-event residuals should be used to demonstrate that of Section, 1st the single mixture model proposed by the Tl Team can be used to Sentence characterize all of them. Please provide the analysis of residuals that was performed for ASK14 for the other three NGA-West2 GMPEs and demonstrate that the proposed normal distribution and mixture model is appropriate for all four GMPEs. 126. Section 11.6. Page Please describe the "statistical tests" that were performed and provide a 11-3, 2nd Paragraph reference for these tests. of Section, 2nd Line 127. Section 11.6. Page Please clarify who conducted the tests on KiK-net data. If it was outside 11-3. Paragraph 2. the SWUS project, please provide a reference. If it was within the SWUS Line 6 project, please give more technical material so there is sufficient technical basis to support the conclusions derived from the KiK-net data. 128. Section 11.6, Page Please rewrite this paragraph to give a more rigorous presentation of 11-3. Paragraph 3 mixture model. including appropriate references. The phrase "a sum of multiple normal distribution" could easily be misunderstood by those who are not familiar with the concept of mixture model. 129. Section 11.6, Page Please describe the technical evaluations that lead to the selection of 11-3. Paragraph 3. mixture of two normal distributions with equal mean. Line 3 130. Section 11.6. Page Please describe the technical evaluations/calibrations that lead to the 11-4, Paragraph 2. (0.5, 0.5) mixture weight and the (1.2, 0.8) scale factors, and that justify Line 4 the application of the model to all of relevant GMPEs (even though the model was calibrated using ASK 14 residuals). Were parameters obtained by trial and error or by methods of statistical inference? 131. Section 11.6. Page Note also that the parenthetical epsilon range should be written with a 11-4. Paragraph 2. minus sign. i.e."(<= -3)" Sentence 6 132. Section 11.6, Page The upper case phi in this equation appears to be the cumulative 11-4. Equation 11-2 distribution function. Please check that the notation has been introduced and defined prior to its use at this point. 133. Section 11.6, Page Please explain what a composite normal distribution is. 11-4, Paragraph 4, Line 1 134. Section 11.6, Page Please provide the technical justification for allowing a normal 11-4, Paragraph 4, distribution with non-zero weight, given that you report that your analysis Line 2 consistently showed heavy tails. 135. References , General Please remove those references that are not cited in the text. comment 136. References, Page 11-Please update the Dawood et al. (2014) reference to include the volume 5. Item 2 and page numbers of the published version. if available. 137. Figure 11-1, Page 11-Caption should explain the meaning of the color scheme used for the 6 weights 138. Figure 11-2, Page 11-Please explain what "Studentized Residual" is in the y-axis label, and 7 correct the caption by replacing "T=2 sec" with 'T=0.5 sec" 139. Figure 11-3, Page 11-Please replace "ASK" with "ASK14" in the cap1ion 8 CHAPTER 12 Phi Model Logic Tree: PVNGS 140. General The chapter is tersely written, often with insufficient background information provided, and insufficiently thorough documentation of the logic tree and the assessment and evaluation that went into determining its branches and weights. Please ensure that the chapter is self-contained, with an adequate summary that references back to Chapter 7 (sigma overview chapter), and other chapters and appendices as needed. 141. Section 12. Page 12-Please replace"/" with "and" here and elsewhere in Chapter 12 to avoid 1, 1st Paragraph, 1st confusion that the term "q>ss I q>s*-f<" refers to a ratio. Line 142. Page 12-1. Paragraph Please clarify whether the first motivation implies there is a significant 1. Line 5 dependence of oon magnitude. distance. and style of faulting. 143. Section 12.1.1. Page Please remove "residual" to clarify that the aleatory distribution is for (j)ss. 12-1, 2nd Paragraph of Section, 4th Line 144. Section 12. 1 . 1 , Page Please consider moving this sentence to the beginning of this section. 12-1, Paragraph 2, Lines 4 to 6 145. Section 12.1.2, Page Please provide a reference to the section where the necessity to use 12-1. Paragraph 1. both datasets is discussed. Sentence 1. Line 1 146. Section 12.1.2. Page Please also reference the published erratum to Akkar et al. (2014 ), in 12-1. 1st Paragraph of which case the reference becomes Akkar et al. (2014a.b). Section, 2nd Line 147. Section 12. 1 . 2, Page Please specify the magnitude and distance range. Also, please confirm 12-2. Paragraph t. that the developers mentioned in this sentence are the NGA GMPE Lines 4 and 5 developers. 148. Section 12.1.2, Page Please consider summarizing these data statistics in a table. Also. t2-2. Paragraph, 1 please clarify if these statistics are based on a data subset in which Lines 3 to 9 each station recorded at least 3 earthquakes. t49. Section 12.1.2. Page Please provide a reference to the sensitivity analyses that show that 12-2, 2nd Paragraph, large (M > 6) magnitudes are important for the hazard calculations at 2nd Line PVNGS. t50. Section 12.1.2. Page Only one limitation of the European dataset is listed as justification for 12-2. 3rd Paragraph the smaller weight given to the European dataset; whereas, several limitations are mentioned in the previous paragraph. Please clarify whether these other limitations contributed to the Tl Team's assessment to give the European dataset less weight. t51. Section 12.1.4. Page Please justify the use of weights of 0.2, 0.6, and 0.2 to define the t2-2. 1st Paragraph of central, 5th, and 95th percentiles of the epistemic distribution of 'Pss. Section, 2nd Please also be specific whether the central value represents the mean Sentence or median. 152. Section 12.2.1, Page The phrase "are added to" could be misleading (suggesting t2-3. 2nd Paragraph mathematical addition of unspecified quantities). so please consider of Section. 3rd Line using another wording. t53. Section 12.2.1. Page Please remove "residual" to clarify that the aleatory distribution is for 12-3. 3rd Paragraph <t>ss. of Section, 4th Line t54. Section 12.2.2. Page Please summarize why a single dataset is appropriate for each branch t2-3. 1st Paragraph of of the logic tree. Section, 4th Line t55. Section 12.2.3. Page Please provide a reference to specific sections, pages. tables, and/or 12-4. 1st Paragraph of figures to Appendix N. Section, 1st Line t56. Section 12.2.4. Page Please provide the basis for the increased CV (i.e .. COV) from 0.14 to t2-4. Paragraph t. 0. t 7 (and please ensure that terminology for coefficient of variation is Line 2 consistent throughout the report and appendices). t57. Section 12.2.4. Page Please justify using weights of 0.2. 0.6. and 0.2 to represent the 5th. t2-4. 1st Paragraph of central. and 95th percentiles of the epistemic distribution of the Phi Section, Last terms. Please also be specific whether the central value represents the Sentence mean or median. 158. Section 12.2.5, Page Please clarify who made the judgment and describe the basis for the 12-4, Paragraph 1. judgment. Line 3: 159. Section 12.2.5, Page Please provide the technical justification for allowing a normal 12-4. Paragraph t. distribution with non-zero weight. given that your analysis consistently Line 4 showed heavy tails. t60. Section 12.3. Page Please revise the date to "2014a" to reflect the published manuscript and t2-4. 1st Item the fact that the erratum was published in the same year. t61. Section 12.3. Page Please update Akkar et al. (2014) to Akkar et al. (2014b} and provide the 12-4, Item 2 volume and page numbers of the published erratum. 162. Section 12.3. Page Please remove the Abrahamson et al. (2014) reference or cite it in the 12-4. Item 3 text. 163. Figure 12-2 Figure is incorrectly numbered ('"Figure 1") CHAPTER 13 Total Sigma Model 164. The chapter is tersely written. often with insufficient background information provided, and insufficiently thorough documentation of the logic tree and the assessment and evaluation that went into determining its branches and weights. Please ensure that the chapter is self-contained, with an adequate summary that references back to Chapter 7 (sigma overview chapter). and other chapters and appendices as needed. 165. Section 13.1 Please provide an overview of the methodology used in other recent SSHAC Level 3 PSHA studies to construct total sigma models. 166. Section 13.1 This methodology can significantly benefit from an extensive rewrite (including related parts in Chapters 7, 10, 11, and 12) to improve readability and understandability. Please provide a clear and easy-to-understand presentation of the basic principles and ideas behind the methodology. which should also serve to connect the various pieces presented across Chapters 7, 10, 11, 12, and 13. 167. Section 13.1. Page Please verify and. if found incorrect, provide the proper references 13-1, Paragraph 1. where logic-tree branches are presented. Line 1 168. Section 13.1. Page Please check whether this report section actually applies the Miller and 13-1, Paragraph 1, Rice (1983) methodology. Otherwise the reference to that paper here is Line 2 misleading and should be dropped. Consider whether Keefer and Bodily is an appropriate reference for the type of distribution resampling applied here. 169. Section 13.1. Page The reference to the book by Ang and Tang (2007) is too general. 13-1. Paragraph 1. Please confirm that this reference is the appropriate one for the discrete Line 3 representation of scaled Chi-squared distributions, and if so, please cite page number(s). 170. Section 13.2, Page Theo here appears to be the same as in Eq 5.4.1-1 on page 6-20 13-1, Paragraph 1. (October 2014 draft), and in Section 13.4, second to last line on page Lines 5-6 and Eq. 13-13-3 If that is correct. please replace cr with crss throughout the chapter 1 for consistency with terminology used elsewhere in the report. 171. Section 13.2. Page Please discuss or reference the "results" being referred to in the 13-1, 1st Paragraph of statement "results that show a very weak negative correlation between t Section, 10th Line and 1!J". 172. Section 13.2, Page Section 7 .3.1 does not provide the definitions of the scaled chi-squared 13-2. Paragraph 1. distribution as claimed. Please provide a correct reference. Line 1: 173. Section 13.2, Page The first equality is flawed: no non-constant function of xis equal to the 13-2, Paragraph 1, same function of x'. This abuse of notation is confusing. If it is necessary Equation 13-3 to introduce the first equality, please clarify its meaning. 174. Section 13.2, Page In equation 13-4, c is defined as a function of sigma-squared, treated as 13-2. Paragraph 1. a deterministic variable, but sigma is a random variable in Equation 13-3. Equations 13-4. 13-5. The same applies to the definition of constant kin Equation 13-5 The substitution of Equations 13-4 and 13-5 into 13-3 leads to incomprehensible results. Please define and use notation that clearly distinguishes between the random variable and the deterministic variable that represents a distribution model parameter. This should be done in a manner that maintains consistency with the rest of the report notation. 175. Section 13.2, Page Please indicate what typical numerical values of c and k are. 13-2. Paragraph 1. following Eqn 13-5 176. Section 13.2. Page Please provide an explanation of what a "weighted composite CDF" is 13-2, Paragraph 2, and how it was computed. Also, please confirm that the composite CDF Lines 5-6 is for lflss only (as indicated in the legend of Figure 13-4). Finally, please explain why composite CDF for Cj)ss is created and presented in this chapter. not in Chapters 11. 12. Also note that the sentence beginning on line 5 ("Using weights ... ) is garbled-please revise to clarify its meaning. 177. Section 13.2. Page Please add text to explain how the weighted composite CDF for cJ>ss was 13-2, Paragraph 2, used to form the composite distribution of total sigma given in Table 13-Line 5-7 1. 178. Section 13.2, Page Please provide a reference for the statement made in this sentence. If it 13-2, Paragraph 2, is based on SWUS's own investigation, then please include, at a Sentence 6 minimum. a supporting figure for this conclusion. 179. Section 13.2, Page Please confirm that variance, not standard error, was the quantity that 13-2, Paragraph 1. was used in the analysis throughout this report. Also, please explain Last Line ( Eq. 13-6) how you go from a model of variance to a model (Eq. 13-6) of standard deviation. 180. Section 13.2, Page Also please reference where in the report the basis for Equation 13-6 13-2. Paragraph 1. can be found Last Line ( Eq. 13-6) 181. Section 13.3. Page Please briefly summarize the three uncertainty models being referred to 13-2. 1st Paragraph of in this sentence. and clarify that the models for PVNGS are Oss (or <Jlss.,) Section models (as opposed to 4>) 182. Section 13.3.1. Page Please add text to discuss the need for two alternative models. 13-3. Paragraph 1. Line 2 183. Section 13.3.1, Page In addition to Table 13-2, please also provide a figure similar to Figure 13-3, 1st Paragraph of 13.4 to show how well the composite distribution fits the original Section, Last distribution. c:.,,ntence 184. Section 13.3.2. Page In addition to Tables 13-3 and 13-4. please also provide a figure similar 13-3. 1st Paragraph of to Figure 13.4 to show how well the composite distribution fits the Section, Last original distribu1ion. Sentence 185. Section 13.4. Page Please provide a reference (such as Jayaram and Baker. 2010) for the 13-3, 1st Paragraph of statement "it leads to an increase in the 4> estimates and decrease in the Section, 3rd Line 'estimates", or provide another basis for this statement. 186. Section 13.4, Page According to Appendix R, the analysis was done on the model of CY14 13-3. 1st Paragraph of (Chiou and Youngs. 2014). Please remove "preliminary" and revise the Section, 5th Line date from "2013" to "2014" in the statement "preliminary CY14 (Chiou and Youngs, 2013)" to conform to the discussion in Appendix R. 187. Section 13.4. Page Please change the reference to Shahi (2014 ). here and at other 13-3. Paragraph 1. locations. to reflect the multiple authors of Appendix R Also. please use Line 5 some alternative style for the citation, as the author/year form of citation is only appropriate for an article or report that appears in the reference list, not for an internal reference to an appendix, which is an integral part of the report. 188. Section 13.4, Page Please clarify what the terms "homoscedastic" and "heteroscedastic 13-3. 1st Paragraph of refer to in this context. Section, 6th and 7th Lines 189. Section 13.4, Page Please clarify who conducted the semivariogram analysis (was it the Tl 13-3, Paragraph 1. Team or Shahi et al., Appendix R), and provide a reference that Line 9 describes the semivariogram analysis methodogy. 190. Section 13.4, Page Please explain what normalization factor was used for the normalized 13-3, Paragraph 1, variogram. Please also change the figure caption and the y-axis label of Line 12 Figure 13-6 to reflect the use of normalized variogram. 191. Section 13.4. Page Please specify the amount of reduction in tau that was used to obtain the 13-3. Paragraph 1. 4% increase in total sigma. Third to Last Line 192. Section 13.4. Page Please justify why it is appropriate to change the weights for all spectral 13-4. 1st Paragraph. periods when the analyses of Jayaram and Baker (2010} and Appendix 3rd Sentence R indicate that they are period-dependent. Please also explain how what appears to be a relatively large degree of epistemic uncertainty depending on the dataset that is used to perform the analyses is taken into account. when results are available for only two datasets. 193. Section 13.4. Page Please discuss whether the modified weights (which constitute a skewed 13-4, Paragraph 1. discrete distribution) adequately capture the true shape of the sigma Last Sentence distribution that accounts for spatial correlation in residuals. Please also discuss if the 3-4% increase in mean sigma is justified and if the variance of total sigma is unaffected by the consideration of spatial ,., 194. Section 13.5. Page In previous discussions of these distributions. they were described as 13-4. 1st Paragraph of normal and a mixture of normal without "log" in front of them. It was Section, 1st Sentence relatively clear that this was because the distributions were developed from the within-event residuals, which have natural log units. The use of "log" now can be confusing given these previous discussions. Please explain why "log" is now being used to describe these normal distributions for additional clarity or remove log" and describe that the distribution is on a parameter that has units of natural log. 195. Section 13.5. Page Since <J>ss. not o. was used in Eq 13-1. please justify the decision to apply 13-4. Paragraph 1. the same factors and weights for cp to <J>ss-Line 4 196. Section 13.5. Page Please replace "event-to-event" with "between-event" to be consistent 13-4, 1st Paragraph of with terminology used elsewhere in the report. Section, 6th Line 197. Section 13.5. Page Since <J>ss. not o. was used in Eq. 13-1. please rewrite this sentence in 13-4, Last Sentence terms of 198. Section 13.6, Page Please update the Abrahamson et al. (2014) reference to include the 13-4. Item 1 page numbers of the published manuscript. 199. Section 13.6. Page Please provide the location of publisher for the Ang and Tang (2007) 13-4, Item 2 reference. 200. Section 13.6, Page The date is incorrect. This report is actually Chiou and Youngs, 2013. 13-4, fourth entry But please remove it from references, since the citation in Appendix R is actually of the published paper. Chiou and Youngs (2014) 201. Section 13.6. Page Please update the Chiou and Youngs (2014) reference to include the 13-5. Item 1 page numbers of the published manuscript. 202. Section 13.6, Page As noted in an earlier comment, it is questionable whether this article 13-5, Last item was correctly cited. If the citation is deleted, please also delete this reference section entry and replace with the correct reference. 203. Table 13-4, Page 13-Sigma listed in other tables show an increasing trend with period. Please 9 provide explanation for the decreasing trend shown in this table. Also. at T>= 5 sec. the central branch in Table 13-3 is higher than the central branch in Table 13-4. Please clarify whether cl>s*-f< is supposed to be always lower than <l>ss for all periods (because of the removal of systematic path effect) and whether the above-mentioned reversal is expected. 204. Figure 13-6, Page 13-Please note that the legends are erroneous in both the upper and lower 6 panels: the exponential functions are incorrectly identified with the blue asterisk symbols instead of with the red curves. 205. Figure 13-7. Page 13-The caption refers to "preliminary CY14 model and cites Chiou and 14 Youngs (2013). But Append ix R says that the Shahi et al. analysis is for the published work, not the preliminary model, and cites the published paper Chiou and Youngs (2014). Please correct, and use an appropriate reference to Appendix R rather than the author/date citation of Shahi. APPENDIX L Path Terms for PVNG and Associated Phi _sp-r Model 206. Section L.1, Page L-1, 1st Please explain why path-specific effects are used and why they are Paragraph, 1st Sentence appropriate for modeling the ground motion from California and Mexico earthquakes. It would also be helpful to clarify in this introductory paragraph that cl>sP-R is an alternative model to Oss for representing site-specific within-event standard deviation (that they are mutually exclusive alternative models for PVNGS). 207. Section L.1, Page L-1, Line The notation 4!>sro-* is used here without introduction. Please ensure that 3 notation is defined at the time it is introduced. 208. Section L.2, Page L-1, 1st Please reference the specific dataset(s) from Chapter 5, and explain why paragraph of section only four spectral periods are available and why these four periods are sufficient to conduct the analysis of path terms 209. Section L.2, Page L-1, 1st Please provide full references or previously defined acronyms for the "4 Paragraph of Section. 3rd NGA-West2 GMPES" the first time they are mentioned in the appendix. Line 210. Section L.2, Page L-1, First Please clarify whether every AZ station recorded the same set of CA Paragraph, Line 7 events. If not. please add text to comment how this situation is addressed in Equations (L-3) through (L-8). 211. Section L.2, Page L-1, 2nd Consider saying "for sources in regions" instead of "for regions", to avoid Paragraph of Section. first any misinterpretation that within-region paths are being characterized line rather than region-to-PVNGS paths. 212. Section L.2, Page L-1, 2nd Please give specific reference to the chapter. section. and figure Paragraph of Section, first number(s) where the three regions are defined. line 213. Section L.2, Page L-1, Please justify Eq. (L-2) as representing the average path term. Second Paragraph, Line 4 214. Section L.2, Page L-1, Please define NGMr*-Equation L-2 215. Section L.2, Page L-1, 2nd Please replace "eq(x}" with the correct equation reference. Paragraph of Section. 6th Line 216. Section L.2, Page L-1, 2nd This sentence is redundant (as the same information is conveyed by the Paragraph of Section, 7th parenthetical remark two sentences earlier). If retained, please change Line NGA-W-2 to a consistent abbreviation used throughout report. 217. Section L.2, Page L-2, Please define NSTA;. and NEQKk. Equation L-3 218. Section L.2, Page L-2, 1st Please explain the need to preserve the range of the medians obtained sentence after Eqn L-4 'rom the 4 GMPEs. and be specific about the medians being referred to. Note also that this and the following sentence mix references to "median" and "mean". If this distinction is intended, please clarify; otherwise, please use terminology that consistently treats either amplitudes or log amplitudes as the principal variate. 219. Section L.2, Page L-2, 2°0 Please be specific about the "residuals" referred to in this sentence. sentence after Eqn L-4 220. Section L.2, Page L-2, 2nd Please justify why a minimum of 5 recordings for each station is adequate Paragraph on page. 1st in this analysis and explain why this number is larger than the minimum of Line 3 recordings used in other analyses conducted for the project. Please also explain if those earthquakes with less than 5 recordings were discarded or used in other parts of the analysis. 221. Section L.2, Pages L-2. Please discuss the possibility of mapping the path term into the site term Second Paragraph on and the consequences of such miss-mapping, if significant. page, Line 3 222. Section L.2, Page L-3, 1st Please consider using a font for the lower-case L" subscript that is less Paragraph on page, 1" line apt to be mistaken for a "one", and please write region 1 with a font that after Eqn L-8 is less apt to be mistaken for "lower-case L". 223. Section L.2, Page L-3, 1st For completeness, please provide the equation for the standard error of Paragraph, first 2 lines after he mean path terms. Eqn L-9 224. Section L.2, Page L-3. 2nd Please explain why the value for T = 0.2 sec was not used in deriving the Paragraph on page. second central path term when Figure L.5 shows that it is similar to the other line after Eqn L-10 periods. and also why the average of the few available periods is an appropriate representation for all periods. 225. Section L.2, Page L-3. 2nd Please consider removing the discussion of logic-tree branches and Paragraph. 3rd Sentence weights and reserve this discussion instead for the report section on the appropriate logic-tree models. It would seem appropriate to discuss the high and low uncertainty bounds, but the evaluation of the central, low, and high values should be presented in the discussion of the logic-tree models 226. Section L.2, Page L-3. 2nd Please explain why T = 02 sec was not used for the shorter periods and Paragraph, 4th Sentence why T = 2 sec was not used for the mid-periods, given that additional uncertainty was added for periods greater than 2 sec. It appears that the entire uncertainty model is based primarily on only two spectral periods. Please explain the justification and basis for the path terms. given that essentially only two spectral periods are used in the assessment 227. Section L.2, Page L-3. Please provide rationale for the need for additional epistemic uncertainty Second Paragraph. 2"d to 'or T > 2 sec. and for the approach by which that additional epistemic last sentence of section uncertainty is determined. Also, please explain why it is not needed for T < 2 sec. 228. Section L.2, Page L-3. Please clarify if the uncertainty in the path term due to the small sample general size and small magnitude range (all but 2 data point are from M<5.2 events) of AZ data needs to be incorporated. 229. Section L.3, Page L-4, 1st Please reference Figure L.8 for the statement 'The ci>sr-R (T) at a period of Paragraph, last Sentence 0.2 sec was not used in deriving the central model due to the large variability in the values obtained for the 4 GMPEs at this period and because sources in regions 1, 2. and 3 do not contribute significantly to he hazard at short periods. 230. Section L.3, Page L-4, 1st Please explain why the mean estimate. including the 0.2 sec value. is not Paragraph, last Sentence appropriate to use (even though the variability might be larger). If indeed he hazard is not impacted at T = 0.2 period from the California/Mexico earthquakes, then that should be sufficient to ignore it, but then that leaves only three periods (all defining a slope) to describe what happens at T < 0.5 sec and T > 2 sec. Please explain the justification for assuming a constant value of <JlsP-R beyond the limits of the observations. when all hree of the observations defines a frequency-dependent slope. 231. Section L.3, Page L-4, 1st Please cite the specific section and figure(s) of the report where it is Paragraph, last Sentence demonstrated that hazard at 0.2 sec is not impacted by sources in regions 1, 2, and 3. 232. Section L.3, Page L-4, 2nd Please justify why a scaled chi-square distribution is appropriate and Paragraph. 1st Sentence provide a reference for this distribution and the related equations (or reference a section of the report where the issue is treated). Although the discussion of low and high values is appropriate. please consider removing any discussion of logic-tree branches and reserve this assessment for the discussion of the logic-tree models. 233. Section L.3, Page L-4, 2nd Please expand the discussion of the COV with equations or additional text Paragraph. 2nd and 3rd (and rewrite for better clarity) to show how the COV of 0.17 was Sentences estimated. Also please ensure that a consistent notation for coefficient of variation is used throughout the report. 234. Section L.4, Page L-4 Please provide missing references APPENDIX M Phi_ss Models for DCPP 235. General Section 11.3 refers to Appendix M for the Tl Team's technical basis of giving 0 weight to the magnitude-dependent Oss branch. However, such basis is not yet provided in this Appendix. Please add details of the technical evaluations that support the selection of O branch weight for the magnitude-dependent-IJ>ss branch. 236. Section M .1, Page M-Please confirm that the acronyms ASK14, BSSA14, CB14, and CY14 1, 1st Paragraph, 2nd are defined by their full citations the first time they are used and verify Line that they are included in the list of acronyms. 237. Section M.1, Pate M-"CA" should be spelled out as "California", and should be accompanied t. 1"' paragraph, line 3 by the name of a specific dataset that has already been defined and listed in a table of data sets elsewhere in the report (and that table should be referenced here). The specific dataset name should be used consistently throughout the report. 238. Section M .1, Page M-Please explain why non-NGA data from regions other than Taiwan (such 1, First Paragraph, as the Japanese data set used in the PAGASUS project) are not Line 3 considered in this project. 239. Section M.1, Page M-Please indicate whether the terms "site terms and single-station within-t. 1st Paragraph. 5th event residuals" have been defined in the main report prior to being Line mentioned in Appendix M. If not. these terms require a specific reference to a section in the report or another appendix for their definition or they should be defined when first used in Appendix M. 240. Section M .1, Page M-Please indicate how the site terms and single-station within-event 1. 2nd Paragraph, 1st residuals were calculated from the entire database for CB14. which only and 2nd Lines fit an average anelastic attenuation term with data from distances of 80-500 km (i.e .. the more distant data was not used to develop all of the parameters in the GMPE and, therefore, do not necessarily have unbiased between-event or within-event residuals beyond 80 km}. 241. Section M. t. Page M-Please provide the justification and basis for the specific magnitude and 1. 3rd Paragraph. 1st distance ranges that were selected. Sentence 242. Section M. t. Page M-Please describe the specific <Jlss terms that are referred to in this 1, 3rd Paragraph, Last sentence, and explain why this sentence does not contradict the Sentence statement made in Section 11.3 (Page 11-2, Second Paragraph) that "For the global data set, a magnitude-dependence in the Oss is not seen". 243. Section M .1, Page M-Does this wording mean that the Lin et al dataset has been 1. 4 lh paragraph. 1 sl superimposed on each of the NGA-West2 datasets? Are the red circles sentence to denote "Taiwan" representing part of the NGA-West2 datasets. or are these from Lin et al., or both? Please clarify. 244. Section M. t. page M-Please replace the lower right plot with the data distribution plot for t. 41to paragraph. and CY14. Also. please check all the plots for accuracy: it seems odd. for Page M-5, Figure M.1 example, that the CB14 plot shows only a handful of Italy data and no Japan data at all. 245. Section M.2. Page M-This sentence seems to have a missing word. Please rewrite to make its 2. 1 "' sentence meaning clear. 246. Section M .2, Page M-Please provide plots similar to those in Figure M.4 for a wider range of 2. 1st Paragraph. 3rd spectral periods to more thoroughly document the magnitude-dependent Sentence Oss model. 247. Section M.2. Page M-Please consider changing the word "variances" to "<Jl<ss" for clarity. 2. 1st Paragraph. end of 3rd Sentence 248. Section M.2. Page M-2, 1" Paragraph, Please consider a rewrite of this sentence for accuracy and clarity. Lines 4 and 5 249. Section M .2, Page M-Please describe how the estimated <Pss was smoothed over periods 2, First Paragraph, given estimates at only 5 periods. Lines 6 and 7, Figure M.3 250. Section M.2. Page M-Please provide a justification and basis for using only a magnitude-2. 2nd Paragraph, tst dependent <Jlss model and not a model that is dependent on both Line magnitude and distance. 251. Section M.2. Page M-Please correct "M.4" to "M.5". 2, 2nd Paragraph, Line 5 252. Section M.2, Page M-Please also reference Table M.2 for the a and b coefficients in Equation 2, 2nd Paragraph, (M-1) and explain how the "high" and "low" values in Table M.2 were Last Sentence determined Although Table M.2 is referenced in the next section. because the a and b coefficients are presented here. their tabulated values should be referenced. 253. Section M.3, Page M-Please carefully review this sentence for accuracy and reword for clarity. 3. First Paragraph. Lines 1 and 2 Dr. Carola Di Section M.3, Page M-Please provide the technical basis for selecting 0.12 as being Alessandro 3. Second Paragraph, representative. Please also clarify whether hazard is sensitive to the Line 4 COV value and if there is significant uncertainty in selecting the value 1 .. 255. Section M.3, Page M-Please add text to discuss the evidence and implication of the 3, Second Paragraph, magnitude-independence of COV, particularly for evaluating the Line 4 epistemic uncertainty in the magnitude-dependent <Jlss-256. Section M.3, Page M-Please provide justification for the use of a chi-square distribution and 3, 2nd Paragraph, provide a reference to this distribution and the related equations. Last Sentence 257. Section M.3, Page M-Please add text to provide a source of or derivation for the relationship 3, Second Paragraph, = 2

• COV(<llsss). last sentence 258. Section M.4. Page M-Please provide the missing references. 3, References 259. Table M.1, Page M-4 Please provide another table that lists the number of earthquakes and recordings for the M5.5 and greater database. Please also indicate that these statistics are for sites with at least 3 recordings. 260. Figure M.2, Page M-6 Please explain why not all of the common spectral periods included in the NGA-West2 GMPEs are included in Figure M.2.

261. Figure M.3, Page M-7 Please explain why the values for the models and their averages are shown for only five spectral periods in Figure M.3. 262. Figure M.5. Page M-8 Please explain why only a subset of the available spectral periods for the NGA-West2 GMPEs are used and why there is no value at 10 sec period; whereas, this period is shown in other figures. 263. Figure M.8. Page M-Please explain why not all of the common spectral periods included in 11 the NGA-West2 GMPEs are included in Figure M.8. 264. Figure M.9, Page M-Please explain why the values for the models and their averages are 12 shown for only five spectral periods in Figure M.9. 265. Figure M.10, Page M-Please explain why not all of the common spectral periods included in 13 the NGA-West2 GMPEs are included in Figure M.13 266. Figure M.10. page M-Because there are two global datasets employed in Chapter 11 and 13 Appendix M, the caption, if it alludes to "the global dataset," the text should make it clear that the "global dataset" referenced here is the one specifically used to derive the epistemic uncertainty in Oss (which is distinct from the other global dataset specifically used to derive the central oss model, for which the magnitude-dependent branch does not exist). APPENDIX N Phi_ss Models for PVNGS 267. Section N. 1. general It is potentially confusing that ci>ss and <J>sr.R are discussed in separate comment appendices (N and L, respectively), even though they seem to be mutually exclusive alternative branches of the same logic-tree node. Please provide some connective discussion to clarify this relationship. 268. Section N. 1, Page N-Please reconsider the use of the term "proponent" in this context, as it 1, 1st Paragraph of may cause confusion as to whether the proponent is an outside expert or Section, 1st Line is the Tl Team. 269. Section N.2. Page N-Please quantify what is meant by "important" and provide a specific 1. 1"' paragraph, line 2 (section, figure number} reference to the part of the report where these deaggregation results are documented. Also note the misplaced word "consideration". 270. Section N.2. page N-Please reference the precise dataset names established and tabulated 21 1 sl paragraph, line earlier in the report. and the section number where they were defined. 4 271. Section N.2, Page N-Please explain why the California database used for DCPP is not also a 1, 1st Paragraph of viable dataset for regional Arizona sources. Section, Last Sentence 272. Section N.2.1, Page N-1, Please explain why the use of 3 recordings per station is sufficient to 1st Paragraph of Section, define a site term (especially since 5 recordings were used for other 1st Line aspects of the study as reported elsewhere in the report). 273. Section N.2.1, Page N-1, Please replace Lin et al. (2010) with Lin et al. (2011 ). 1st Paragraph of Section, 2nd Line 274. Section N.2.1, Page Judging from the identical values of N.1 and M.1, the global dataset N-1. 1*1 Paragraph, used in this Appendix is the same as the dataset used in Appendix M. Is Lines 6 and 7 it necessary to repeat the same plots and table here (an issue because of the two appendices instead of one)? It will also help if each dataset is precisely defined and given a unique identifier early in the report and referred to consistently by that identifier thereafter. 275. Section N.2.1, Page The language on average of 1,200-1 , 700 recordings 1,460 recordings N-1 . 1 ,, paragraph. from 72-106 earthquakes" is incomprehensible as written. Please clarify. Lines 5 and 6 276. Section N.2.1, Page Same comments about Figure M-1 are also applicable to Figure N.1 N-1 , 1" Paragraph, Lines 7 (Figure N.1) 277. Section N.2.2, Page Please reference the precise dataset names established and tabulated N-1 , 1" paragraph, earlier in the report, and the section number where they were defined. lines 3-4 278. Section N.3.1, Page There appears to be a trend with magnitude when the entire magnitude N-2, 1st Paragraph of range is taken as a whole. Please provide a quantitative definition of Section, 3rd Sentence what is meant by "significant" and how this definition supports the Tl Team's assessment of assuming magnitude-independence of Oss. 279. Section N.3.2. Page Please see previous comments regarding justification of the use of a chi-N-2. 1st Paragraph of square distribution and the specific value for the COV. Please also Section, 2nd and 3rd provide a basis for the "assumption" that the COV for the European data Sentences is the same as for the global data. 280. Section N.3.3, Page Please explain the difference in the oss model (derived from the same N-2. First Paragraph global dataset using the same methodology) between the greater AZ (Table N.3) and the DCPP (Table M.2). Please also explain the use of different assumption about period dependence for smoothing across periods (there is no period dependence for AZ). 281. Section N.3.3. Page Please see previous comments regarding use of the chi-square N-2. 1st paragraph of distribution and the specific value for the COV. Please also clarify section, line 2-4 whether hazard is sensitive to the GOV value and whether there is significant uncertainty in selecting the value. 282. Please provide a reference to the sensitivity studies that show the Section N.4, Page N-magnitude and distance ranges that control the hazard. 2. 1st Paragraph of Section, 1st Sentence 283. Section N.4, Page N-2. Please reference Figure N-6 for a definition of regions 1, 2, and 3. 1st Paragraph of Section, 3rd Line 284. Section N.4, Page N-Appendix L refers to records in the distance range 200-500 km (section 2, 1" paragraph of L.2). Please explain why a different range is used here. Same comment section, line 4 applies to Line 3 on next page, and Line 3 of section N.5. 285. Section N.4, Page N-Please explain why this renders the CB14 model unusable at large 2. 1st Paragraph of distances Section, 2nd Sentence 286. Section N.5, Page N-Please see previous comments on justification of the chi-square 3, 1st Paragraph of distribution and use of the specific value of the COV, and the Section, 3rd and 4th presentation of logic-tree branch weights. Sentences 287. Section N.5, Page N-Please discuss the cause of the decreasing trend of i!lss with period at 3. First Paragraph. large distances (i.e .. for sources in Regions 1, 2. and 3), as shown in Lines 7 and 8 Figure N.8. 288. Section N.6, Page N-Please correct the date of this publication to 2014a to agree with the 3. 2nd Reference published date of the manuscript 289. Section N.6. Page N-Please correct the date of this publication to 2014b and include the 3, 3rd Reference volume and page numbers of the published version. 290. Table N.3. Page N-6 Please correct the heading of the second column from 'CA data' to 'European data'. 291. Table N.1, Page N-5, Please clarify whether this table also includes the Taiwanese recordings Caption from the Lin et al. (2011) study. 292. Figure N.5, Page N-Please explain why only five periods are shown in this figure. 10 293. Figure N.7, Page N-Please check the accuracy of these plots. 12 294. Figure N.8, Page N-Please correct the caption to indicate that the figure is for sources in 13, caption Regions 1, 2, and 3 (not 4). APPENDIX R Spatial Correlation 295. General Please consider formatting this appendix for consistency and visual uniformity with the rest of the report (font: section. equation and page numbering style, etc) 296. Abstract. Page 1. Line Please consider revising this sentence to reflect the fact that only the 7 model of aleatory variability was refitted. the coefficients of the median relation were fixed to the values estimated by Chiou and Youngs (as stated in Section 3, Page 4, First Paragraph). 297. Section 1 . Page 1 . Please consider changing the word "prediction" to "modeling. First Paragraph. Last Line 298. Section R. 1. Page 2. o, appears to be the same as what is elsewhere in the report called r. 1 *1 paragraph. Line 8 Please make changes here. and elsewhere in the appendix. to ensure that the notation is consistent throughout the report. 299. Section R. 1. Page 2. Please clarify the importance of these two sentences in the context of 1st Paragraph. last 2 the present study. and clarify whether "regions" refers to spatial regions sentences (e.g .. California or Japan) or regions in ground-motion parameter space (e.g., ranges of magnitude and distance). 300. Section R. 1. Page 2. This sentence is confusingly worded because it does not indicate for 2"c paragraph, 2rd what pairs of things correlations are being modeled. Please reword for sentence clarity (for example. "models the correlation of ground motion intensity between sites ... "). 301. Section R. 1. Page 2. Please quantitatively define what is meant by "significantly". 2nd Paragraph. 14th Line 302. Section R.1, Page 2, Please replace "NGA West 2" with "NGA-West2" to be consistent with 2nd Paragraph, 17th the acronym used by the NGA project and used elsewhere in the report Line and appendices. 303. Section R.1, Page 2, Please change this citation to "(Ancheta et al., 2014)" to be consistent 2nd Paragraph. Last with the published journal article. or alternatively reference both the Line PEER reoort and the iournal article. 304. Section 2. Page 3. The statement that a magnitude-dependent model is "closer" to the truth First Paragraph, 1" than the magnitude-independent model seems to contradict the Tl sentence Team's assessed branch weights in the GMC logic tree (equally weighted in Fig 11.1. 12.1. 12.2, and binary weighted in Fig 10.1 ). Please revise or explain how this sentence is consistent with the Tl Team's assessment of these two alternatives. Please also provide a reference to publications by the cited "ground-motion modelers" that suggest magnitude dependence. 305. Section R.2, Page 3, Please describe what simplifications were made to the Chiou and 2nd Paragraph, 1st Youngs (2014) variance model for the present study. Sentence 306. Section R.2, Page 3, Please define what the symbols "s" and "t" refer to in Equations (3) and 2nd Paragraph. 3rd (4). Sentence 307. Section R.2. Page 3. It might be useful to clarify parenthetically that "s" and "s prime" 3rd Paragraph, 4th mentioned here is not the same as "s" in Eq. (4). Line 308. Section R.2, Page 3, Please justify why the equations for "r" given by Jayaram and Baker 3rd Paragraph, 9th (2009) are also appropriate for the within-event residuals of CY14. Line 309. Section R.3, Page 4. Please explain why the results of Jayaram and Baker (2010) and Hong 1st Paragraph. 2nd et al. (2009) are robust enough to permit assuming that the CY14 Sentence coefficients will not chance. 310. Section 3. Page 4. This equation (Eq. 8) seems to be a duplicate of Eq. 2. Please review it First Paragraph. Line and make clarifications as needed. 8 311. Section 3, Page 4, Please review whether "o ** " in these equations should really be i::as", and Second Paragraph, consider clarifying the intent of these equations. Lines 3 to 5 (Eq. 9 to Eq. 10) 312. Section R.3. Page 4. Please provide a published statistical reference for Eqs. (9), (10), and 2nd Paragraph. (11 ). Equations (9) to ( 11) 313. Section 3. Page 4. Please justify the assumption of non-correlation in light of the presence Third Paragraph. of a site-specific term, which could induce correlation between residuals Lines 3 and 4 across different events recorded at the same site. 314. Section R.4. Page 5. The standard deviations derived without considering spatial correlation 2nd Paragraph. 1st should have been similar to those obtained by CY14 Please show that Sentence this is the case or, if not, why not. 315. Section R.4, Page 5, Please clarify whether "these results" refers to the homoskedastic or 3rd Paragraph, 1st heteroskedastic results, or both. Line 316. References, page 5, 4'h reference Please provide a volume number for this reference. 317. References. Page 6. Please update this reference to include volume and page numbers. 3rd Reference 318. References, Page 6, Please provide a more complete reference (e.g., conference date, 6th Reference conference proceedings title, publisher, etc.). 319. Table 1, Page 7, Please clarify that these are "standard deviation model" coefficients, and Caption not median model coefficients. 320. Table 2. Page 8. 5th The value "0.367" appears to be a typo. Please verify this value and Row, 3rd Column revise accordingly. January 5, 2015 Dr. Carola Di J\ lessandro SWUS Project Manager GeoPentech, Inc. 525 N. Cabrillo Park Drive, Suite 280 Santa Ana, CA 9270 I

Subject:

Participatory Peer Review Panel Letter No. 2: Rev.0 Report, Southwest United States Ground Motion Characterization Level 3 SSHAC Project

Dear Dr. Di Alessandro:

This letter provides comments and recommendations of the Participatory Peer Review Panel (PPRP) for the SWUS Project Report, Rev.0. Here we address Chapters 6, 8, 9, and 14, and Appendices H. I, J, K, 0, and Q. Our Letter No. I (dated December 13, 2014) already provided comments on Chapters 7, 10. 11, 12, and 13. and Appendices L. M, N, and R. We have not yet had the opportunity to thoroughly review the remainder of the report, some of which is not yet available to us at this time. It should be appreciated, therefore, that the portions of the report considered in this letter may be subject to further comment once the PPRP has reviewed the remainder of the report. The review comments are tabulated by chapter and identified by section. page, paragraph, sentence or line number, and table or figure number where appropriate. Each comment in the review is assigned a unique number for reference. Comments transmitted with Letter No. I were numbered 1-320, and the numbering of comments transmitted with the current letter start with 321. The table includes an additional column in which the responses of the TI Team may be recorded. The review is not intended to be editorial, but we do call attention to stylistic or grammatical concerns in instances where they substantially affect clarity or may introduce ambiguities. The Rev .0 report covers the full scope of the evaluation and integration efforts of the Tl Team. The review comments from the PPRP are intended to help the Tl Team clarify and expand as necessary the technical basis and justifications for the models and weights used in the final GMC logic trees. Sincerely, Steven M. Day Chair, PPRP Brian Chiou Member, PPRP Kenneth W. Campbell Member, PPRP I , f // /-* .. *'" Thomas K. Rockwell Member, PPRP Comment Response Table Comment Location in PPRP Comment Summary of Revisions to Report Number Text CHAPTER 6 GMC Models for the Median 321. Section 6. 1 , Page 6-1 , The "base-model GMPEs" are called by other names-e.g., "proponent First Paragraph, First Line GMPES", or "selected candidate GMPEs" (as in the next paragraph of th is section) -in other parts of the report. Please select an appropriate name for these GMPEs and consistently use this name throughout the report and appendices. If "base model" is intended to mean something else in this context, please define this term the first time it is used and include it in the list of terms. 322. Section 6. 1, page 6-1 , Please explain the concept of a "space of GMPEs, or make it clear that paragraph 2, line 2 this is a concept that is going to be fully explained later in the chapter, and reference the section where the explanation is given. It would also be advisable to develop a terminology that distinguishes actual GMPEs from the virtual GMPEs constructed from the common form. as the lack of consistent, distinct terms for these entities is a frequent source of ambiguity in the rest of the chapter. 323. Section 6.2.1, Page 6-1. Please replace "Akkar et al. (2013, 2014)" with "Akkar et al. (2014a,b)" 2nd Bullet here and elsewhere throughout the chapter to indicate that both the original manuscript and the erratum were published in the same year. 324 Section 6 2. 1. page 6-1. Idriss (2014) is referred to here as 114. whereas it is ld14 in the figures 6'h bulleted item and elsewhere in the text. Please make these acronyms consistent. 325. Section 6.2.1, Page 6-1. Zhao and Lu (2011) is not a GMPE, but a method for accounting for 8th Bullet saturation of magnitude scaling. Please summarize how this magnitude scaling is used to construct a GMPE for purposes of the Tl Team's evaluation and provide a more meaningful description and acronym for this model. 326. Section 6.2.1, page 6-2. Please indicate quantitatively what is meant by "large magnitude" in this 1" paragraph on page, context. line4 327 Section 62.1. Page 6-2. Please provide a reference for the finite-fault simulations (e.g .. Appendix 2nd Paragraph on page, J as well as citations to references in the list of references). 2nd Sentence 328 Section 62.1. Page 6-2. Please provide a more complete citation to "Idriss 3rd Paragraph on page, 10th Line 329. Section 6.2.1, page 6-2, Please provide additional justification for the exclusion of 114 at 3'" paragraph on page, distances less than 3 km, beyond its status as an outlier relative to other last sentence GMPEs and simulated data. 330. Section 6.2.1, page 6-2. Please check the magnitude of the Kocaeli earthquake, which is given 4'" paragraph on page, as 7.51 in the NGA-West 2 flatfile. line 2 331 Section 6.2.1. page 6-2. Please include a reference to the report section (and figure number if 5 paragraph in section appropriate) where the sensitivity result cited here is demonstrated. (last on paQe ). Line 1 332 Section 6.2.1. page 6-2. The figure is for a relatively long period (0.5 Hz). so it would be helpful 5'h paragraph in section. here to complete the argument by recalling that the long periods are the Line 4 worst case for hazard sensitivity at this distance range (and to reference the report section and figure(s) where that is demonstrated). 333. Section 6.2.1, page 6-2, Please provide a more precise statement of what is meant by "the last paragraph of page, candidate GMPEs is reasonable for application to DCPP" and provide last line the justification for this judgment, or a reference to the report section where this justification is given. 334 Section 6.2.2. Page 6-3. Please replace "Bindi et al (2014)" with .. Bindi et al. (2014a.b)" here and 3rd Bullet elsewhere throughout the chapter to indicate that both the original manuscript and the erratum were both published in the same year. 335 Section 6.2.2. page 6-3. Please explain more fully the justification for excluding the Bindi et al. 1*1 paragraph of section. (2014) model. or provide specific reference(s) to the section(s) where lines following bullets that justification is fully explained. and explain whether ASB 14 has similar limitations. 336. Section 6.2.3, page 6-3. Please reference more specifically-section number, and figure number 1" paragraph of section, if appropriate-where the sensitivity result cited here is demonstrated. Line 2 337 Section 6 2.3. page 6-3. Please state quantitatively what is meant by "large magnitude" in this 1" paragraph of section, context. Line 3 338. Section 6.2.3, page 6-3, The structure of the final sentence of the paragraph is a little awkward paragraph 1 of section. (particularly its formulation as a rhetorical question). and the expression lines 4.5 "large distance attenuation" is ambiguous in meaning. Please consider rewriting the sentence to improve its clarity and precision. 339. Section 6.2.3, Page 6-3. Please replace "Kashida et al. (2014a)" with "Kashida et al. (2014)" here 2nd Paragraph of and elsewhere in the chapter to reflect the fact that there is only one Section, 3rd Line such reference listed in the references. 340 Section 6 2.3. Page 6-3. Please explain how the California event terms were calculated. or 3rd Paragraph of Section, provide a reference to the report section where the explanation is given. Last Sentence on page 341 Section 6 2 3. page 6-4. Here and elsewhere ... California/Mexico should read "California and paragraph 4 of section Mexico" for clarity. Same in the next paragraph where "southernfcentral" (2'" on page). last line should read "southern and central." 342 Section 6.2.3. Page 6-4. Please include the Phillips et al. (2013) reference in the list of last paragraph of section, references. 2nd Line 343 Section 6 2.3. page 6-4. The strong frequency dependence of Q evident in Figures 6.2 3-2 and 5'h (last) paragraph of 6.2.3-3 increases the differences between California and Arizona Q at 5 section, last sentence Hz (upper left panel of each figure), so please reference the sensitivity studies that demonstrate the absence of hazard significance at 5 Hz for California sources. 344 Section 6 3. general The relegation of part of the hanging wall discussion to Appendix K is somewhat awkward and inefficient. Please consider integration of the material from that appendix into the various subsections of 6 3. 345. Section 6.3, Page 6-5. 1st Please include the Abrahamson and Silva (2008) and Campbell and Line on page Bozorgnia (2008) references in the list of references. 346 Section 6 3. page 6-5, The statement that Rjb implicitly accounts for the hanging wall effect last paragraph of section, could be seen as contradicting the result noted later that the Rjb last sen1ence distance metric alone does not account for the dip-dependence of the hanging wall effect Please modify this sta1ement to note that Rjb does not agree with simulations for shallow-dipping scenarios and reference the sections of the report where this is discussed. 347 Sec1ion 6 3. 1. page 6-5. Please consider whether "moderate" is a better descriptor than 1 sl paragraph' Line 3 "average". in order to avoid the suggestion that this is a rigorous statistical measure. 348. Section 6.3.1, Page 6-5. Please explain why the Rjb-based ASB14 GMPE was not used to 1st Paragraph of Section, evaluate HW effects, given that the Rbj-based BSSA14 GMPE was 4th Sen1ence found to be suitable. 349 Section 6 31. Page 6-5. Please provide a specific reference 1o the report section that describes 2nd Paragraph of the "additional simulations" that were done for the SWUS project. Section, 1st Sentence 350. Section 6.3.1, page 6-6. The phrase "Moves off of the hanging wall" is ambiguous, as it does not 3*d paragraph of section make it clear whether the reference is to distant points still on the (1" on page). line 3 of hanging wall side of the surface projection of the top of the rupture. to paragraph points on the footwall side of the surface projection of the top of the rupture, or to both. Please clarify. 351. Section 6.3.1, page 6-6, The phrase "Moderate magnitude scaling" is ambiguous. Please clarify; 3'" paragraph of section for example, if the intent is to refer to scaling at moderate magnitudes, (1" on page). line 5 of please hyphenate as in the phrase "moderate-magnitude scaling." paragraph 352 Section 6 3. 1. page 6-6. The notion of "magnitude taper" has not been defined. and by itself is 3'" paragraph of section ambiguous. Please clarify. ( 1" on page). 2rd to last sentence 353. Section 6.3.1, page 6-6. The discussions in Appendix J (Pages J-41 and J-42) and Appendix K 3*d paragraph of section (Section K.1.2) suggest that the magnitude tapers of ASK 14 and CB14, (1" on page). second to but not CY14, are too strong compared to the magnitude scaling of the last sen1ence HW effect revealed by the simulated data. Please revise this sentence to reflect the conclusions described in Appendix J and Appendix K. 354 Section 6.3.2. Page 6-6. At this point in the chapter the Rjb-based models have not been 1st Paragraph of Section, eliminated as being inappropriate. Please explain why the Rjb-based 2nd Sentence models are not used in developing the HW model. 355 Section 6.3.2. page 6-6. The scaled-backbone approach has not been defined nor is a reference 1" paragraph of section, cited. Please correct this. Line 4 356. Section 6.3.2, Page 6 -6, To avoid misinterpretation. please include text to note that, although a First Paragraph. Last magnitude taper was not explicitly included, Eqs. (6.3-1) and (6.3-2) still Sentence provide a magnitude scaling of the HW effect. as was explained in Appendix J (Page J-42). 357. Section 6.3.2, Page 6-6. Please clarify how the total hanging wall effect is to be modeled by the 3 2"" paragraph of section, equations (e.g .. is it the product of the three factors defined in these Eqns 6.3-1.2,3 equations?). and also define the variable "W". 358 Section 6 3.2. Page 6-6. Comprehension of this sentence depends upon familiarity with Appendix 3'" paragraph of section. K. For example, it does not make sense to say "Five equally weighted line 1 alternative HW factor models were developed .... ",because. logically. models have to be developed before they can be assigned weights. Nor is it clear what is meant by equal probability of the C1 coefficient. Please rewrite and expand the text to make this section sufficiently self-contained to be understandable. 359 Section 6 3.2. Page 6-6. The terminology "weighted factors" in Lines 2 and 3, is a source of paragraph of section. confusion. and without familiarity with Appendix K, the sentence is sentence incomprehensible. Please reword and expand for clarity. and give a more specific reference to the relevant appendix subsection(s). Please note that this is a place where the division of the material between the chapter and the related appendix seems especially inefficient. 360 Section 6 3.3. Page 6-7. Please indicate that additional comparison plots similar to Figure 6.3 3-1 1st Paragraph. 4th are given in Appendix K. Sentence 361. Section 6.3.3, Page 6-7. The assessment that Rjb-based HW models are not appropriate for 2nd Paragraph shallow dips is important Please provide an example plot to show that these models are not appropriate and that Rrup-based models adequately model HW effects. and reference where in the report or appendices the discussion of this topic can be found. 362. Section 6.4, Page 6-7. Please explain the following: What does mutually exclusive" mean? Are First Paragraph, Third the candidate GMPEs mutually exclusive? Why is it important to use Line mutually exclusive GMPEs for the characterization of the CBR of median amplitude? What are the impacts on hazard if GMPEs are not mutually exclusive? 363 Section 6.4. page 6-7, 1*' "Sammon's mapping" is called "Sammon's map" in Section 6.1. If there paragraph of section, Line is no distinction between these, please use a consistent terminology. 11 364 Section 6.4. Page 6-7. The term "base model" has not been defined at this point in the chapter. 2nd Paragraph of Please define the term "base model" the first time it is used and include Section, 1st Line it in the list of terms. 365. Section 6.4.1, Page 6-8. Please expand this sentence to explain why a common functional form 1st Paragraph of Section, for all of the candidate models is needed or reference appropriate 1st Sentence sections in an appendix where this information can be found. 366. Section 6.4.1, Page 6-8, Please indicate what is meant by the phrase "induces a distribution of 1st Paragraph of Section, GMPEs", and indicate where in the chapter this concept will be 3rd Line expanded upon. 367. Section 6.4.1, Page 6-8. There could be confusion when the term "models" is used between 1st Paragraph of Section, whether this refers to the candidate GMPEs or to the simulated GMPEs. 7th Line Please select a common terminology for these two types of models and use this terminology consistently throughout the report and appendices in order to avoid confusion. 368. Section 6.4.1, Page 6-8. Please be more specific by what is meant by "scaling". If it refers to the 2nd Paragraph of scaling terms in the GMPEs, please consider replacing "scaling" with Section, 3rd Line "scaling terms" here and elsewhere in the report and appendices. Please also qualify what type of scaling is meant when the term is used elsewhere throughout the report and appendices. 369. Section 6.4.1, page 6-8. Please define NML as an acronym for "normal" here if this is the first 2"" paragraph of section, time it is used and include it in the list of terms. 4 line after Ean 6.4-1 370 Section 6.4.1. page 6-8. Please define the acronym "SS" (implying strike slip) the first time it is 2"d paragraph of section, used and include it in the list of terms. 81h line after Eqn 6.4-1 371. Section 6.4. 1, page 6-8, Please clarify what SS:NML and SS:REV mean and replace "based on 2"" paragraph of section, the scaling in the eight candidate GMPEs" with more precise language. last 2 sentences Also explain why the specific scenarios for estimating SS:REV and SS:NML factors are appropriate and if the results are sensitive to the choice of the selected scenario. Please also explain why the same scenario is appropriate for both DCPP and PVNGS. considering that their hazard is impacted by potentially different magnitudes and distances. 372. Section 6.4. 1, page 6-9, Please indicate what function is being referred to in the statement "this 3*d paragraph of section. function." and by whom it is considered to have the stated flexibility. If (1" on page) lines 2 and this is the assessment of the Tl Team, please say so. and provide the 3. basis for this judgment by demonstrating that Eqs. (6.4-1) and (6.4-2) are flexible enough to capture the full range of scaling of the selected candidate GMPEs. That might entail, for example, showing the misfits to the original GMPEs as a function of magnitude and distance. Also, please discuss whether the misfits to the original GMPEs significantly affect the hazards. or reference the report section where such a discussion is provided. 373. Section 6.4.1, Page 6-9. Please explain why this transformation of coefficients is necessary and 3'" paragraph of section how it leads to squared coerticient terms in Eq. (6.4-2). (1st on page). 3rd Sentence 374 Section 6 4. 1. page 6-9. 3'" paragraph of section Please check the equation. Shouldn't as(7) be squared? (1" on page), Eqn 6.4-2 375. Section 6.4.1, Page 6-9. Please clarify what the phrase the square" refers to with respect to Eq. 3*d paragraph of section (6.4-2) and/or the definition of the model coefficients. (1st on page). 13th Line 376. Section 6.4. 1, Page 6-9, The intended point of this sentence is unclear. Please revise to make it 4'" paragraph of section clear. (1" paragraph after Eqn 6.4-2), 1*1 sentence 377 Section 6 4. 1. Page 6-9. Please justify that the Ztor effects of the ASK14. CB14. and CY14 4'" paragraph of section GMPEs are adequately captured by the common-form models with a8 = ( 1" paragraph after Eqn 0. 6.4-2), 2°0 sentence 378 Section 6 4. 1. Page 6-9. Please describe what the three Ztor values are supposed to represent 4 paragraph of section and how they were used in the regression analysis (e.g .. were they (1" paragraph after Eqn equally weighted or weighted by some other probability distribution). 6.4-2), last sentence Also please revise the reference to the Ztor model of CY 14 to be more specific (e.g., "the Ztor-M relationship developed by CY14"). 379 Section 6 4. 1. 1. page 6-9. The explanation in this section is incomplete. in that it is never explicitly general comment stated that numerical log(Sa) predictions of each GMPE, for the given M and Rx set, are used as data to determine a best-fitting coefficient vecto1 for the common form to that GMPE, nor what fitting criterion is applied. Please make the explanation more complete. This same comment applies to Section 6.4.1.2. 380 Section 6 4. 1. 1. Page 6-9, Please explain what is meant by the phrase "for comparison of the 1st Paragraph of Section, GMPEs" 3rd Line 381. Section 6.4.1.1, Page 6-9, Please explain how predictor variables Rrup and Rjb were determined, 1" Paragraph, first 2 lines given Mand Rx. and clarify who the developers" are (e.g., the NGA-after the bullets West2 developers or the candidate GMPE developers meaning the Tl Team) 382 Section 6 4. 1. 1. Page 6-The phrase " . is only included to constrain the fitted models at large 10, 1"' paragraph, 1" line distances ... " has the connotation that the large-distance scenarios are on page used in a limited fashion in the fitting process. Please clarify and revise this paragraph as needed. 383. Section 6.4.1.1, Page 6-Please provide a reference in the report or appendices where the 10, 1st Paragraph, 3rd definition and calculation of "hazard-relevant" scenarios can be found. Line 384. Section 6.4. 1.2, Page 6-Please clarify who the "developers" are (e.g., the NGA-West2 10, 1st Paragraph of developers or the candidate GMPE developers meaning the Tl Team). Section, 2"* line after the bullets 385. Section 6.4. 1.2, Page 6-Please explain the basis for "assuming" a SO-degree dip and indicate 10, 1st Paragraph of whether the results are sensitive to this assumption. Section, 2"* line after the bullets 386 Section 6.4.2, General To provide more complete documentation. please list the covariance matrices in Appendix H. 387. Sections 6.4.2 and 6.4.3, The method used to generate the simulated GMPEs and project them General comment onto Sammon's maps is new and requires detailed documentation to fully understand the methodology. Please provide more detailed documentation on the generation of the covariance matrices, the simulated GMPEs. and the Sammon's maps, including all related equations, either in Chapter 6 or in an appendix. 388 Section 6.4.2, page 6-10. This short section is mainly devoted to describing the use of section title interpolation to facilitate the estimation of the coefficient correlations. It is not clear what the title "generation of models" refers to. In the subsequent section (6.4.3), model generation seems to refer to the sampling of the coefficient space to create sample GMPEs. so the use of "model generation" as the title of Section 6.4.2 seems confusing. Please consider changes to remedy this confusion. 389 Section 64.2. page 6-10. Please explain the difficulties encountered in estimating the correlations 1" paragraph of section, of the coefficients using the original GMPEs alone, and justify how it is sentences 2,3, and line 5 mathematically possible with the addition of the interpolated GMPEs to better capture the correlations. Also provide the rationale for the interpolation weights selected. and clarify whether the interpolation was done by interpolating the coefficients or by interpolating the ground motion vectors and refitting to the common form. 390. Section 6.4.2, page 6-10, The last set of weights (2/3, 1/2) do not add to 1, while the other two 1" paragraph of section, sets do add to 1. Please review and revise as needed. line 5 391 Section 6 4.2. Page 6-11, Is this approach (for treating the case T>3 sec) mentioned for the first 2"d Paragraph of section time here? If so. please add a paragraph in Section 6.1 so the reader (1" on page). Last are aware of it from the very beginning. Sentence 392 Section 6 4.3. page 6-11. Please add an explanation of what is meant by model generation and 1" paragraph of section how it is done. At this point, for example, there has been no explicit (1" on page), 1" sentence explanation that models in this section are generated by sampling the on page common-form coefficient distribution estimated in the previous step, nor have any necessary assumptions about the joint distribution of the coefficient distribution been explicitly stated. 393. Section 6.4.3, page 6-11, Please clarify what is meant by "for a few scenarios." Doesn't Figure 1*1 paragraph of section. 6.4.3-1 apply to just a single set of predictor variables (i.e .. a single 3*d sentence value each for magnitude. distance. and style of faulting)? In addition. please state what predictor values were used (that information should be in the figure caption as well). 394. Section 6.4.3, page 6-11, Please indicate by whom the judgment was made, and on what basis, 1" paragraph of section, and consider whether "range" is the appropriate term here, as opposed last sentence of to, e.g., distribution" or "center, body, and range" (there are other paragraph instances throughout the report where the usage of "'range" should also be reviewed and revised where appropriate). 395 Section 6 4.3. page 6-11. Please clarify whether the good agreement seen in the example 1*1 paragraph of section. scenario was also observed in all other scenarios important to the last sentence of hazards at DCPP and PVNGS. paragraph 396 Section 6 4.3. page 6-11. Some explanation of the nature of the Sammon's map should precede 3'" paragraph of section. this instance of its application. Please consider doing some 1" sentence reorganization of this section to put the developments in a more logical order. 397. Section 6.4.3, page 6-11, The range of values of the Sammon's map coordinates in Figure 6.4.3-2, 3'" paragraph of sec1ion, for the original GMPEs, is roughly plus/minus 10. This is more than an 1" sentence order of magnitude greater than the range shown in, e.g., Fig. 9.1-3b of Chapter 9. Please explain the reason for the difference Also please explain the reason for the difference in axis labels in different parts of the report. i.e .. "C 1,C2" is used here and in Chapter 9. versus the axis labels In units" shown for seemingly analogous plots in Chapter 8 and Annendix H. 398. Section 6.4.3, Page 6-11, Please explain why there is a trade-off between the "likelihood and an 4'" Paragraph, Last 2 optimized standard deviation", what the sensitivity of the results is to sentences using a fixed standard deviation. and what the rationale is for selecting that value from BSSA 14 over the other GMPEs. 399. Section 6.4.3, Page 6-11, Please describe the Tl Team's reasons for including the simulated data 5'" Paragraph, 1" in the model evaluation, or point to the section where those reasons are Sentence described. 400. Section 6.4.3, Page 6-12, Please provide a reference for the "80% and 20%" proportions of relative 2nd Line on page rates of normal and strike-slip mechanisms for the Arizona sources. 401. Section 6.4.3, page 6-12, Please rewrite this sentence to improve clarity. It is not clear what part of 7'" paragraph of section the analysis was done using the central HW term, nor at what stage the (2'" on page). 2"d and 3'" random HW models are introduced instead. nor why this two-stage sentences analysis method was chosen. 402 Section 6 4.3. Page 6-12, Please provide citations for principal component analysis and Sammon's 9th Paragraph of section (4'" on page). 1*1 maps if they haven't been provided previously in the chapter. Sentence 403 Section 6 4.3. Page 6-12, Please describe the Tl Team's motivation to base the selection of the 9th Paragraph of section representative model on the resulting hazards, and to select the model (41" on page), 2"" with hazard closest to the mean hazard (as opposed to, e.g., the median Sentence or another quantile hazard level). Please also describe the scatter in the hazard from models in the same cell. 404. Section 6.4.3, Page 6-12, Please verify that the simplified SSC models for DCPP and PVNGS 9th Paragraph of section (41" on page), 3" being used are consistent with the final SSC models for these sites. Sentence 405 Section 6 4.3. Page 6-12, Please explain the basis for selecting the "one specific HW model". 9th Paragraph of section (4'" on page). 6'" line 406. Section 6.4.3, page 6-12, The concept of using random HW models in the development of the 9'" paragraph of section Sammon's maps for PVNGS and a random HW model assigned arter (4'" on page), last the selection of a GMPE for each cell for DCPP is unclear. Please sentence provide additional explanation of how this method is applied and why it is needed in order to help the reader better understand the methodology. 407 Section 64.3. page 6-12. Please clarify what is meant by an approximately uniform distribution of 9 paragraph of section hanging wall factors (e.g .. according to Appendix K. the HW factors were (4'" on page), last developed under the assumption of a normal distribution), and why it is sentence important. 408 Section 64.3. page 6-12. Please describe how the outputs of principal component analysis 1 o'" paragraph of section (presumably. a set of 2-D coordinates) are used as inputs for the (5'" on page). 1*1 construction of Sammon's maps. and provide a reference for the "principal component analysis and Sammon's maps" methodology that is being used 409. Section 6.4.3, page 6-12, Please indicate whether the model vector concatenates a set of periods, 1 o'" paragraph of section or a separate model vector is constructed for each of a set of periods. In (5"' on page). 2"d either case. please indicate what set of periods was used. Also please sentence consider changes to emphasize even more explicitly that the vector space is a space of ground motion valued n-tuples. and to draw a clear distinction between this vector space and the space of common-form coefficient vectors used in the model generation stage. 410 Section 64.3. page 6-13. Please rewrite this sentence (and perhaps add additional text) to make 1011' paragraph of section its meaning clear The explanation should clarify that each vector (1" on page). 1" full component is a In( Sa) value for a particular combination of predictor sentence on page variables. The lists of predictor values (for DCPP and PVNGS, respectively) should also be given at this point (e.g., are they the values listed later on 1his page and called "deaggregation bins" or values listed on Pages 6-9 and 6-1 O?) Presumably one of those sets was used in the fitting and the other in model generation. but it is difficult for the reader to figure this out The explanation should also clarify that the analysis is done independently at each period, if that is the case. 411. Section 64.3. page 6-13. Please be precise and consistent in the use of terminology. The symbol 101" paragraph of section "w" in this line is defined as the importance of the scenario. but in the (1" on page). 1" line after next sentence it is call the weight," and later something called Eqn 6.4-4 deaggregation weight" is referenced. If these all mean the same thing, the terminology should be consistent; if they do not, their distinction should be clarified. 412. Section 64.3. page 6-13. This line states that the weights are computed from "the deaggregation." 10'" paragraph of section But this is the first time "deaggregation" has been mentioned in the (1" on page), 2"" line afte1 chapter, so the use of the definite article (indicating something already Eqn 6.4-4 introduced) is very confusing. Please rewrite this statement to make it clear that a new element is being introduced into the analysis. Please also be more specific than just referring generically to "deaggregation" by saying. e.g .. "hazard deaggregation matrix" and by specifying what return periods and spectral periods are used to perform the deaggregation. 413. Section 6.4.3, page 6-13, Please clarify what GMPE distribution is referred to here, and what is 10111 paragraph of section meant by "mean model." For example, is this distribution that of the eight (1" on page). 2*d line afte1 original GMPEs. or of the 2000 virtual GMPEs in the constructed Eqn 64-4 ensemble. and is the "mean model" the virtual GMPE that occupies the position in Sammon's map space that represents the geometrical centroid of the original GMPEs? 414. Section 64.3. page 6-13. The term "deaggregation weight" has not been defined. Please explain 1 o'" paragraph of section how it is related to the deaggregated hazard (e.g., is it some function of (1" on page), 3'd and 4'" the probability of exceedance value at a given ground motion level, or line after Eqn 6.4-4 simply the probability value itself, normalized in some way?). Please also state precisely and quantitatively what was done, and include the defining equation for the deaggregation weight. 415. Section 6.4.3, page 6-13, The statement that the mean of the deaggregation weights" is "used as 10'" paragraph of section w in Eq. (6.4-4) is inconsistent with the subsequent explanation in which (1" on page). 4"' line after this mean is given a different symbol. w_bar. and is used in Eq. (6.4-4). Eqn 64-4 in combination with the number 1/N. to give w. Please rewrite this statement to provide a precise and consistent explanation. 416. Section 6.4.3, page 6-13, Please clarify if the renormalized weights" are used with Eq. (6.4-4) 11 '" paragraph of section instead of the mean of the 10 deaggregation weights referred to in the (2" on page). 3*d line previous paragraph. 417. Section 6.4.3, page 6-13, Please explain how it was determined that the defined deaggregation 11 '" paragraph of section bins" are sufficient for the purpose of determining the scenario weights. (2" on page), 3*d line after Equation 6.4-5 418 Section 6 4.3. Page 6-14 Please explain why only a mean + 3 km increment was used as an 14'" paragraph of section alternative value for Ztor and not also a mean -3 km increment. Please (1" on page), First Line also explain why 3 km was chosen for the increment and whether the alternative value was given a different weight than the mean. 419. Section 6.4.3, page 6-14, The juxtaposition of the statement that "only one Ztor value is used for 14'" paragraph of section the Rjb-based models, with the statement "these models do not include (top paragraph on page), Ztor scaling," seems illogical. If Ztor does not occur as a predictor 1st fu II sentence variable in a GMPE. it is confusing to suggest that "only one value" of that variable was used. Please rewrite this statement for clarity and nrF>r.i<<inn. 420 Section 6 4.3. Page 6-14, It's not clear how the number 384 is obtained. Based on the information 14th Paragraph (1"' given in this paragraph. there are 6 magnitudes. 13 distances. 2 styles paragraph on page), Line of faulting. and 2 Ztor values: 6 x 13 x 2 x 2 = 312. Please clarify. 7 421. Section 6.4.3, page 6-14, This sentence seems redundant with the content of the previous 15th paragraph of section paragraph, except that the cited dimension of 284 for PVNGS is (2r* paragraph on page), inconsistent with the dimension of 384 in the bulleted list in the 1st sentence preceding paragraph and with the dimension cited in the subsequent sentences (also note that PVNGS is misspelled in both of its occurrences). Please clarify and correct. 422. Section 6.4.3, page 6-14, Please explain the reason for the extra step of first projecting the space 15*h paragraph of section using principal component analysis. (2"" paragraph on page), line4 423 Section 64.3. page 6-14. To avoid confusion, please consider rewriting to avoid the ambiguous 15*h paragraph of section "28813841192 .. notation (here, and elsewhere In the report). For example, (2"" paragraph on page), consider the alternative phrase "each model corresponds to a point in N-2"" sentence dimensional space, where N has values of 288, 384, and 192 for the DCPP. PVNGS Model A. and PVNGA Model B cases. respectively. 424. Section 6.4.3, page 6-14, Please provide the basis or reference for the statement "the first two 15*h paragraph of section principal components, however. typically account for about 85-90% of (2r* paragraph on page), the variance". 3*d sentence 425 Section 6 4.3. page 6-14. This sentence appears to misrepresent what is presented above. Please 15th paragraph of section consider restructuring the sentence to begin "As described above. the (2r* paragraph on page), contributions to the difference in the squared Euclidean distances .. ". 41" sentence 426 Section 6 4.3. page 6-14. Please show the values of deaggregation weight for some example M-15*h paragraph of section distance bins and periods. (2"" paragraph on page), last line 427. Section 64.3. page 6-14. Please check the definition of ex Should the second entry in the set be 2 16t11 paragraph of section (not 0.2)? (3'd paragraph on page}. first line after Eqn 6.4-6 428 Section 6.4.4. page 6-14. Please explain why an ellipse was chosen. in what sense the ellipse is 1*t paragraph of section. best fitting, and why the best fitting ellipse is always horizontally 2"d sentence oriented. 429. Section 6.4.4, page 6-14, The correct expression here is "convex hull" (not "complex"). Please 1" paragraph of section, make that correction, define what it is, and consider whether the ellipse 2"" sentence is fit to the boundary curve of the convex hull. 430. Section 6.4.4, page 6-14, The acronym "GMPE" is used indiscriminately in this chapter, 1*t paragraph of section. sometimes to mean specifically the original set of eight published 2"d sentence GMPEs. other times to refer to members of the ensemble of constructed virtual GMPEs. Please clarify the meaning of GMPE used here and be consistent in uniquely describing which definition of GMPE is meant when it is used elsewhere in the chapter. 431 Section 6.4.4. page 6-14. The expression "uncertainty models" is used here without definition and 1*1 paragraph of section. the resulting text is ambiguous and confusing. Please rewrite for clarity. 2"d sentence If the set of GMPEs formed from the original GMPEs with added epistemic uncertainty is going to be used repeatedly, please introduce an unambiguous terminology and use it consistently. 432. Section 6.4.4, page 6-14, Since it has not been explained how the ellipse is going to be used, the 1" paragraph of section, significance of scaling it up is not clear at this point in the narrative. Nor 3'" sentence is the parenthetical comment comprehensible (e.g., capture the full range of what?). Please rewrite this discussion to clarify the reasoning behind centering and scaling the ellipses this way. including the reasoning behind the choice of the factors 1.5 and 0.5. 433 Section 6.4.4. page 6-14. This sentence is incomprehensible. Please rewrite it for clarity. 1*1 paragraph of section. last sentence 434. Section 6.4.4, page 6-15, Please state what data set(s) the residuals are calculated for, and clarify 2"" paragraph of section whether the between-event residuals are also weighted by (1" paragraph on page). deaggregation weight to emphasize the magnitudes that are more line 1 important for hazard and. if they are not weighted, please explain why. 435 Section 6.4.4. page 6-15. Please provide additional discussion of the method for producing the 2"" paragraph of section ellipses and justify the 5 selected residual values used to define the (1" paragraph on page), intersection points between the residual contours and the ellipses. line 2 436. Section 6.4.4, page 6-15, Please clarify the meaning of "uncertainty models" (see earlier comment 2"" paragraph of section suggesting use of a consistent, unambiguous expression for those (1" paragraph on page), 3*d sentence models) 437. Section 6.4.4, page 6-15, What is meant by the phrase "broadened to capture this range"? That is, 2"" paragraph of section please state which new contours are then selected in that case. (1" paragraph on page), 3'" sentence 438. Section 6.4.4, page 6-15, Please explain what is meant by the ambiguous phrase "center of the 2"" paragraph of section original GMPEs." If this refers to the centroid point in Sammon's map (1" paragraph on page). coordinates. please say so. line 6. 439. Section 6.4.4, page 6-15, 2"" paragraph of section Please give the final number of selected representative points. (1" paragraph on page). last line 440. Section 6.4.4, page 6-Please be specific about the quantity to which the term "range" 15, 3'" paragraph of refers. Please also explain how the range in the location of points on section (2"" paragraph the Sammon's map relates to the range of this quantity. In addition. on page) please explain why the range of Sammon's map coordinates in Figure 6.4.3-2 is larger by more than an order of magnitude than the range of Sammon's map coordinates in Figure 6.4 4-1 and all the other Sammon's map figures in the report. 441. Section 6.4.4. page 6-15. This is the first time the expression "epistemic models" has been used. 3'" paragraph of section Please clarify what is meant by this expression (in contrast to previous (2" paragraph on page), references simply to "models or "GMPEs"). 2"" sentence 442. Section 6.4.4. page 6-15. Please be specific and quantitative about this procedure. For example. 3'" paragraph of section how are the rescaled ellipses defined in the case noted? (2r paragraph on page), 2"" sentence 443. Section 6.4.4, page 6-15, Please be clear that reference is being made to the original GMPEs and 3'" paragraph of section to those GMPEs with the added epistemic uncertainty terms. (2" paragraph on page), sentence 444. Section 6.4.4, page 6-15, Please explain how the model screening was done and what models 3'" paragraph of section were removed during the screening process. paragraph on page), 4'h sentence 445. Section 6.4.4, page 6-15, Please explain the basis for the assumption that "The selected points 4 paragraph of section are assumed to be representative of their neighborhood in ground-(3" paragraph on page). motion space". Line 1 446 Section 6.4.4. page 6-15. Please clarify whether the word "boundaries" means boundaries of the 4'h paragraph of section outer Voronoi polygons. and state the scale factor used to define the (3" paragraph on page). fourth ellipse. Line 3 447. Section 6.4.4, page 6-15, Please explain the reason for not simply using the selected point to 4'h paragraph of section represent the models in a Voronoi cell. (3" paragraph on page). line4 448 Section 6.4.4. page 6-15. The meaning of the phrase "closeness in hazard space for each cell" is 4 paragraph of section not clear. For example, closeness of what to what? Please consider (3r>:1 paragraph on page). whether this sentence can be deleted and the word "therefore" deleted 4'" sentence from the following sentence. 449. Section 6.4.4, page 6-15, Please explain in what sense the hazard curve for the selected model is 4 paragraph of section "closest" to the mean. (3" paragraph on page). 6'h sentence 450 Section 6.4.4. page 6-15. Please explain why selection of this "closest" point as a representative ol 4'" paragraph of section the cell does not contradict the first sentence of the paragraph, which (3" paragraph on page), appears to say that the points on the ellipses selected" in the previous 61" sentence paragraphs "are assumed to be representative of their neighborhood." 451 Section 6.4.4. page 6-15. Please explain how to interpret the x-and y-axis scale of the Sammon's 4*h paragraph of section map. as was requested by many workshop participants during (3" paragraph on page), Workshops 2 and 3 and recommended by the PPRP in its comment last line letters on the workshops. 452. Section 6.4.4, page 6-15, The phrase "distribution of HW branches for the selected representative 5'" paragraph (4:* branches" is awkward. Please consider rewriting this phrase to improve paragraph on page), 1" its clarity. line 453. Section 6.4.4, page 6-15, Please explain why this distribution of HW terms does not contradict the 5'" paragraph of section statement in Section 6.4.3 that "the central hanging wall branch is (4"' paragraph on page), applied for the Sammon's maps." That section also notes that "later the sentence DCPP base models are assigned a random HW models[sic)," but there appears to be no mention of that addition in the intervening text The treatment of the HW terms requires clarification. 454 Section 6.4.4. page 6-15. 5'h paragraph of section (4'" paragraph on page), Please state the rationale for the assessment given in this sentence last line 455 Section 64.5. page 6-15. Please explain the need to assign a weight to each selected model Also 1*1 paragraph of section. note that the sentence refers ambiguously to "representative models for line 1 each cell." Please use the singular "model" to avoid the implication that there could be multiple models selected for a cell, unless that is the intent. 456. Section 6.4.5, page 6-15, Please indicate what data set(s) the statistics are calculated for, and 1" paragraph of section, clarify what is meant by "mean statistic" in this context (e.g., why is it 1 sl sentence appropriate to call the likelihood a mean statistic?). 457 Section 64.5. page 6-16. The same notation. "w". was used for the weights defining the Eqn 6.4-7 Sammon's distance metric. This is potentially confusing, especially since the term "weight" is used for both. Note also that "L" is used in this equation to represent a generic statistic, but the same symbol is defined as the likelihood in the subsequent bulleted list. Please make corrections to ensure that notation throughout the chapter is consistent and unambiguous. 458 Section 64.5. page 6-16. Please replace the typo "combing cell" with "combined cell", or perhaps paragraph 1 on page. even better by "merged cell" to be consistent with the previous sentence. to last line 459 Section 6 4.5. Page 6-16, Please define "M" and "D". Second Paragraph on page, Last Bullet 460. Section 6.4.5.1, page 6-Please explain the basis for assuming that the cited properties of 1he 17, 2°0 paragraph of section (1" paragraph on original GMPEs are also applicable to the constructed GMPEs. page). line 6 461. 6.4.5.1, page 6-17, This sentence is imprecise about the definition of the norms referred to, paragraph 2 of section as well as what space they are defined on. The sentence could be (1" paragraph on page}. interpreted to suggestthat the mean residual is an L1 norm. which it is last sentence not. nor is it even a norm at all. nor is its absolute value (neither one is positive definite). The sentence should be rewritten to make it clear what norms it refers to, and what vector space the norms apply to. Alternatively, if the sentence is not essential to subsequent arguments, please consider deleting it. 462. Section 6.4.6, General Please summarize the Tl Team's assessment of the appropriateness of the selected models and model weights in capturing the center, body, and range of the median amplitude. If such assessments are discussed in Chapters 8 and 9. please provide references to the relevant section( s ). 463 Section 6 4.6. General Please discuss the following observation: For M 7 5 and short periods (PGA and T=0.2s). the ground-motion distribution at larger distance (Rx > 30 km) is broader than at shorter distances (Rx< 10 km); see, for example, Figure 2.178 of Appendix H. Please explain the cause of this behavior. Given that empirical data are sparser at shorter distances, intuitively, shouldn't the epistemic uncertainty be larger at shorter distances than at larger distances? 464 Section 6 4.6. General Please discuss the following observation: For PGA and T=0.2s. ground-motion distributions at Rx=-1 and -5 exhibit a large negative skewness at M > 6.5: see for example. Fig. 2.236 of Appendix H. In contrast, the distribution based on the candidate GMPEs shows much less skewness. Please explain the cause of the negative skewness and justify the appropriateness of the model distribution. Also, please discuss whether the negative skewness may yield more conservative (or less conservative) hazard in comparison to the use of a less skewed distribution (such as the one from the candidate GMPEs). 465. Section 6.4.6, page 6-17, Please correct the section reference. Line 1 466 Section 6 4.6. page 6-17. Please specify the section number in the statement .. in the section for Line 5 PVNGS" 467. Section 6.4.6.1, page 6-Please clarify what the "total weights" case represents, since ii has not 17, 2°0 paragraph in been defined at this point in the text. This expression is also used section. Lines 3 and 4 without definition in Chapter 8-please make necessary edits to ensure claritv. 468 Section 6.4.6.1. page 6-Please clarify whether reference is being made to the original empirical 17, 2"" paragraph in GMPEs or to the constructed virtual GMPEs. section, Lines 4 and 5 469. Section 6.4.6.1, page 6-Please justify the weights 80%110%110%, given that the pluslminus 17, 2°0 paragraph in models are two times the standard error away from the mean. section. Lines 5 470. Section 6.4.6.1, page 6-The expression "pluslminus uncertainty model is imprecise and 17, 2°0 paragraph in ambiguous. Please use a clear, unambiguous terminology for this set of section, Lines 6 and 7 models consistently throughout the chapter. 471. Section 6.4.6.1. page 6-The residual-based weighting case for the NGA dataset is indicated as 18, 3'" paragraph of being the blue curve in Figure 6.4.6-1. That curve appears to define a section ( 1" paragraph on relatively narrow distribution (probably the second narrowest after the page), 1"' 2 sentences likelihood case for the EU dataset), apparently narrower than that of the black curve representing the GMPEs. But the text here says the opposite ("using the residual-based weights yields to[sic] ground motion distribution broader than the one associated to the candidate GMPEs". Furthermore. the prior-based case (brown curve) appears to be one of the broadest, yet the text says" ... prior-based weights lead[s) to narrow distributions." Please provide clarification as to what the conclusion actually is, and then further clarify whether the stated conclusion applies to the majority of scenarios examined in Appendix H (also note the typo. "yields to" instead of "yields a"). 472. Section 6 4.6. 1. page 6-The total weighted distribution of the simulated weighted GMPEs is very 18, 3*d paragraph of similar to the distribution for the GMPEs themselves. Please indicate if section (1" paragraph on this is true in general and if the weights were chosen to closely match page), 3'" sentence the GMPE distribution on average. 473 Section 6.4.6.2. Page 6-Please clarify if the term "quantile is the same as the term "percentile" 18, 1st Paragraph of used elsewhere in the report and appendices and, if it is. please Section, 2nd Line consider consistently using only one of these terms in order to avoid confusion. 474. Section 6.4.6.2, page 6-The phrase "Widthlrange" is vague (e.g., is there a distinction between 18, 1"' paragraph, last line width and range, and if so what is it?). Please use language that is precise about what soecific attribute(s) will be comoared. 475 Section 6 4.6.2. Page 6-Please explain the significance of the comparisons shown in Figures 18, 2nd Paragraph of 6.4.6-2 through 6.4.6-4. It appears that the two distributions are Section aenerallv similar. 476 Section 6 4.6.3. Page 6-Please explain the significance of the quantile ratio plots shown in 18, 2nd Paragraph of Figure 6.4 6-5. Section 477. Section 6.4.6.4, Page 6-Please reconcile the "broader distribution" shown in Figures 6.4.6-6 and 19, 2nd Paragraph of 6.4.6-7 with the previous figures that show similar 0.05, 0.5, and 0.95 Section, 4th Sentence quantiles for the simulated models and the GMPEs. 478 Section 6 5. 1. General There is insufficient discussion of directivity models for the dip-slip earthquake sources. Please enhance the text to address this deficiency. 479. Section 6.5.1, Page 6-19, Please replace "Somerville et al. (1999)" with Somerville et al. (1997)". 1st Paragraph of Section, 2nd Line 480 Section 6.5.1. Page 6-19, There is no mention of magnitude in Figure 6.5.1-1. although it can be 3rd Paragraph of Section. presumed that the different rupture lengths shown in this figure 2nd Line represent different magnitudes. Please include the magnitude in addition to the rupture length in Figure 6.5.1-1 for completeness and to tie the figure to the M8 magnitude mentioned in this sentence. 481. Section 6.5.1, Page 6-20, Please also reference Spudich and others (2014; Earthquake Spectra, 4'" Paragraph of section vol 3., no. 3, page 1199-1221) and Spudich and Chiou (2013; Chapter 5 (2"" on page), First of PEER's directivity working group report), since both gave an in-depth Sentence discussion on the issue of centering. 482 Section 6 5.1. Page 6-20, The NGA-West2 developers had originally concluded that the Chiou and 4'" Paragraph of section Youngs (2014) directivity model could not be used with other GMPEs (2"" on page), 2"" because of the centering issue. Please explain the basis or provide a sentence reference for assuming that the CY14 directivity model can now be used with other GMPEs. 483 Section 6 5.1. Page 6-20, Chiou and Youngs (2014) addressed the effect of directivity on only 4 Paragraph of section median amplitude. Please explain the basis for concluding that there is (2"" on page), line 6 variation of sigma along strike, and explain what sigma is referred being referred to. 484 Section 6 5.1. Page 6-20, Please explain the need for simplifying the application of the directivity 5'" Paragraph of section model. Also ensure that Watson-Lamprey (2014} (still listed as being in 3'" on page}. Line 1 preparation) will be published (or at least be in press) prior to finalizing the PSHA report if the results of the study are to be used by the Tl Team as part of their evaluation. 485 Section 6 5.1. Page 6-20, 5'" Paragraph of section Please provide a definition and a brief description of the variable "OPP." 3'" on page), Line 6 486 Section 6 5.1. Page 6-20, Please indicate if Attachment C passes peer review or the Tl Team's 61" Paragraph of section evaluation. Please describe the Tl Team's basis for accepting the 4'" on page), Line 1 simplified models in Attachment C for use in the hazard calculation. 487. Section 6.5.1, Page 6-20, Please clarify who developed the parametric model, and indicate 7'" Paragraph of section whether rupture depth (which is not mentioned here) was considered as 5'" on page). 1" 2 a parameter and found to be insignificant. sentences 488. Section 6.5.1, page 6-20, If the phrase ... at the ends of the large strike-slip faults," is meant to 81" paragraph of section indicate "at the ends of large strike-slip ruptures," please make that (61" on page), 2*d to last correction. In any case, please clarify the meaning of the phrase. line. 489 Section 6.5.1. page 6-20. To avoid potential misunderstanding. please revise the text to note that a'h paragraph of section this statement refers to the case of treating the hypocenter position as (6'h on page). line 5 random along the fault. not the case where the hypocenter is deterministically specified. 490 Section 6 5.2. Page 6-21, The first sentence is ambiguous (e.g .. "a small impact" could be First Paragraph interpreted to mean a significant one), and the Workshop 3 reference is incorrect (Section 4 does not exist). In any case. please cite the Chapter 14 sensitivity studies here to provide an adequate technical justification for the simplified treatment of directivity. Once the Chapter 14 sensitivities are referenced, consider whether also citing the workshop proceedings is redundant. 491 Section 6 5.2. Page 6-21, Please provide a discussion of other directivity models published since First Paragraph. Last 2008, including why Chiou and Youngs was selected but not alternative Sentence models. 492 Section 6 6.1. Page 6-21, In order to avoid confusion. please reserve the term "proponent models General and "proponent methods" to refer to models or methods proposed by Proponent Experts as defined in the SSHAC guidelines. Please use a different name to refer to models proposed by the Tl Team here and elsewhere throughout the report and appendices. 493. Section 6.6.1, Page 6-21, Please define what is meant by "path terms" the first time it is used, so 2nd Paragraph of the reader need not have to read Appendix L to understand what the Section, 1st Line term means. 494. Section 6.6.1, Page 6-21, Please provide a reference to the specific report sections, tables and/or 3rd Paragraph, Line 3 figures where the description is provided. 495 Section 6 6.2. Page 6-21, Please clarify what the units (and sign) of the path term mean, and First Paragraph, Line 1 explain whether the large negative path term (about-0.5) for regions 2 and 3 appears reasonable on geological and geophysical grounds, such as known differences in crustal structure. Also, please comment on the size of the path term compared to those estimated for other regions by previous studies. 496. Section 6.6.2, Page 6-21, Please comment as to whether additional epistemic uncertainty in the First Paragraph, Line 1 path term is warranted, given that a sparse dataset was used in its estimation. 497 Section 6 7.1. Page 6-22, Please define what is meant by "R" here. First Paragraph. Line 5 498 Section 6 7.1. Page 6-22, The term "PSA" is used on line 7. and "Sa" is used in Eq. (6.7-1). Please First Paragraph, Line 7 select and use a consistent term for this parameter. and Eqn 6.7-1 499. Section 6.7.1, Page 6-22, Please provide a short description of the motivation behind Method 1. First Paragraph. Line 10 500 Section 6 7.1. Page 6-22, Please consider revising the phrase "single representative rupture" so First Paragraph. Last that it will not be misconstrued as a new rupture geometry modified from Sentence the rupture geometry specified in the SSC model. For example, doesn't the method create a single representative set of predictor variables? 501 Section 6 7.1. Page 6-22, Please define the term "WidthDD" here and include it in the list of terms. Second Paragraph, First Sentence 502 Section 6 7.1. Page 6-22, Please check whether the second sentence is redundant-given that it Second Paragraph appears to just repeat the content of the first sentence-and revise if appropriate. 503. Section 6.7.1, Page 6-23, Please define the distance metric R", and consider changing the phrase Paragraph of section "based on distance" to something like "based on inverse-squared paragraph on page), distance". Line 3 504 Section 6.7.2. General There are empirical ground-motion data from historical earthquakes that exhibited complex rupture or splay fault rupture. including those in the NGA-West2 database and the 2011 Fukushima-Hamadori, Japan, earthquake. Please indicate whether these empirical data were used by the Tl Team to evaluate the four proponent methods. If so, please describe the main results of the evaluations: if not, please explain why not. 505 Section 6 7.2.1. Page 6-Please explain what is meant by the term "main rupture" or rewrite the 23, 1st Paragraph of section in a form that does not depend upon making that distinction. Section, Last Line 506. Section 6. 7 .2. 1 , page 6-Please rewrite this sentence to improve its syntax and clarity. 23, paragraph 3 of section. 1*1 sentence 507. Section 6. 7.2.1, Page 6-Please briefly summarize the discussion from Appendix J explaining the 23, Second Paragraph, extent to which these complex scenarios cover the full range present in Line 2 the SSC model. Also please provide specific (subsection number) reference(s) to that discussion to justify the sufficiency of these scenarios. Also, Figure 6.7.2-1 does not provide a clear annotation of the associated geometry for the main rupture, the combined rupture, and the location of the site mentioned on Line 2. Please revise the text and the figure to correct these deficiencies. 508 Section 6 7.2.1. page 6-Please explain more clearly and precisely what the term 23, 3'" paragraph of "complex/simple LN (ratios)" means Also. please use conventional section. lines 3-5 notation such as ln(x) for the natural log of x (here and elsewhere in the report). 509 Section 6.7.2.2. Page 6-Please briefly summarize the discussion from Appendix J explaining that 24, Second Paragraph these splay scenarios cover the full range present in the SSC model. Also please provide specific (subsection number) reference(s) to that discussion to justify the sufficiency of these scenarios. 510 Section 6 7.2.2. page 6-Please rewrite this sentence to clarify its meaning. 24, paragraph 3 of section. 1*1 sentence 511 Section 6 7.2.2. page 6-The text stales lhat "The site is assumed to be localed near the splay 24, 2"* paragraph of rupture (otherwise lhe effect of the splay can be ignored}." If in the upper section. last line right diagram of Figure 6.7.2-1 the site were moved from "near the splay to near the part of the main fault southeast of the junction, what would be different? Please explain the origin of the asymmetry; that is, please explain why the splay can be ignored if the site is near the main fault (the part of the main fault that is SE of the junction. just like the splay is). but the SE part of the main fault cannot be ignored if the site is nearthe splay. Alternatively. consider deleting the parenthetical comment if it is irrelevant to the ground motion model. 512. Section 6.8, Page 6-25, Please provide a more complete description of the Abrahamson (2000) 4th Reference reference (e.g., dates and location of the conference, paper number, proceedings pages, etc.) 513 Section 6 8. Page 6-25, Please update the Abrahamson et al. (2014) reference with page 6th Reference numbers from the published manuscript. 514 Section 6 8. Page 6-25, Please replace the date "2013 with "2014a" in the Akkar et al (2013) 7th Reference reference to reflect the actual date of publication. Note that the "a" should be added because the referenced erratum was published in the same year. 515. Section 6.8, Page 6-25, Please update the Akkar et al. (2014) reference with the volume and 8th Reference page numbers of the published manuscript. Please also replace the date "2014" with "2014b" to reflect the fact that the original manuscript was published in the same year as the erratum. 516. Section 6.8, Page 6-25, Please update the Al Atik and Youngs (2014) reference to include the 9th Reference page numbers of the published manuscript. 517. Section 6.8, Page 6-25, Please replace the date "2013" with "2014a" in the Bindi et al. (2013) 11th Reference reference to reflect the date the manuscript was published and the fact that the erratum was published in the same year. 518. Section 6.8, Page 6-25, Please replace the date "2014" with "2014a" in the Bindi et al. (2014) 12th Reference reference to reflect the fact that the original manuscript was published in the same year. 519. Section 6.8, Page 6-25, Please update the reference Bommer et al. (2014) to include volume 13th Reference and page numbers of the published manuscript. if available. 520 Section 6 8. Page 6-25, Please update the Boore et al. (2014) reference to include the page 15th Reference numbers of the published manuscript. 521 Section 6 8. Page 6-26, Please update the Campbell and Bozorgnia (2014) reference to include 1st Reference the page numbers of the published manuscript. 522 Section 6 8. Page 6-26, Please provide the organization that the Chiou et al. (2000) report was 2nd Reference submitted to. 523. Section 6.8, Page 6-26, Please update the Chiou and Youngs (2014) reference to include the 4th Reference page numbers of the published manuscript. 524. Section 6.8, Page 6-26, The Graizer (2014) reference is not cited in the text. Please either cite 7th Reference this reference or remove it from the list of references. 525 Section 6 8. Page 6-26, The Graves and Pitarka (2014) reference is not cited in the text. but is 8th Reference probably the reference to the acronym "G&P" (also cited as "GP") used to identify one of the simulation methods in some of the figure captions. Please cite this reference the first time that the acronym G&P" is used and use a consistent acronym for this reference. 526. Section 6.8, Page 6-26, Please update the Idriss (2014) reference to include the page numbers 9th Reference of the published manuscript. 527 Section 6 8. Page 6-26, Please replace the date "2014a" with "2014" in the Kashida et al. (2014) 12th Reference reference. 528 Section 6 8. Page 6-26, The Olsen and Takedatsu (2014) reference is not cited in the text. but is 14th Reference probably the reference to the acronym "SDSU" used to identify one of the simulation methods in some of the figure captions. Please cite this reference the first time the acronym "SDSU" is used. 529 Section 6 8. Page 6-26, Please provide a more complete description of the Somerville and 17th Reference Abrahamson (1995) reference (i.e., report number, organization, etc.). 530. Section 6.8, Page 6-27, Please update the Watson-Lamprey (2014) reference with the report 2nd Reference number, publisher, etc., if available. If the report is not published or in press at the time the SWUS report is finalized. any reference to the PEER report should be removed from the report and characterized as an analysis performed for the Tl Team and included as an appendix. 531. Table 6.6-1, Page 6-29 The values given in Table 6.6-1 do not appear to be consistent with the proposed models shown in Figure 6.6.1-2. Please explain why this is the case, or if in error, correct the table or figure. 532 Table 6.7-1. Page 6-30 Please define the term "DDWidth" the first time it is used 533 Figure 6.2.1-1. page 6-31 In the explanation. the acronym "ld14" is used. whereas in the text. it is given as "114. Please choose one and be consistent. This same comment applies to the corresoondina fiaures. 534. Figure 6.2.1-2, Page 6-32 Please explain what the term ZH06 = ZL 11 means in the legend and correct "ZH06" to "Z06" and "ASB13" to "ASB14" to be consistent with the terminology used in the text. 535 Figure 6.2.3-1. page 6-34 The caption refers to periods at 0.2. 0 5, 1.0 and 2.0 seconds. but is not clear as to which panel is which. Please label the individual panels for clarity. Please also remove mention of a specific period in the legend, since period varies from panel to panel. Also correct the legend to refer to the NGA-West2 models by the acronyms used in the text (e.g., "ASK14). 536. Figure 6.2.3-2, Page 6-Please explain the meaning of the phrase "over frequency" in the figure 35, and Figure 6.2.3-3, caption. Page 6-36 537 Figure 6.3.1-2. page 6-38 The solid (5 km) and dashed (10 km) curves should be better explained in the caption. Also. please refer to the GMPEs in the legend by the acronyms used in the 1ext (i.e .. "ASK 14" instead of "ASK") 538 Figure 6.3.3-1. page 6-39 Please add an explanation of the black curves to the caption. Please also define the terms EXSIM, G&P, and SDSU and provide citations to references in the list of references. The apparent references to these models in the list of references are incomplete and should be updated to .. in press" or published when possible. Please note that the reference to EXSIM is missing from the list of references. 539 Figure 6.4.3-1. page 6-40 Please provide in the caption the predictor variable values for which the plot was generated. Also please consider explaining more explicitly that the red curves represent the distribution of the median (mean of natural log) for each GMPE based on the Al-Atik and Youngs (2014) analysis of epistemic uncertainty. 540. Figure 6.4.3-2, page 6-40 Please explain in the caption how to distinguish the Model A and Model B samples. and also give the meaning of the solid dots and their colors. Please also define the axis labels. The plot of sampled models" is for 15.000 samples. but 2,000 samples were used. Please replace this plot with one for 2,000 samples to better represent what was used in the evaluation. 541. Figure 6.4.4-1, page 6-41 Please correct the caption to read "mean between-event residuals," add an explanation of the black dots. and identify the "contours" as the gray lines in the plot. 542. Figures 6.4.6-2, 3 and 4, Please add explanatory text to the caption indicating that the solid lines pages 6-43, 6-44, and 6-are the 0.5 quantiles, whereas the dashed lines represent the 0.05 and 45 0.95 quantiles 543. Figures 6.4.6-2, 3, 4 and Please explain the meaning of the term "total weights" in the figure 5, pages 6-43, 6-44, and caption. 6-45 544. Figure 6.5.1-5, Page 6-47 Please replace the date "1999" with "1997" in the Somerville et al. (1999) reference in the figure caption. 545. Figure 6.6.1-1, page 6-49 Please correct the mislabeling of the figure in its caption. Also, in the caption, please specify which colors are referred to for the "colored lines" that represent faults, as there are also colored lines that separate regions. Also please add the location of PVNGS to the map. Note also that 5 earthquakes appear to be located in Region 1. whereas the text seems to indicate that there are 3 (first line on Page 6-22). Please review and revise this caption as needed. 546 Figure 6.6.1-2. page 6-50 Please correct the mislabeling of the figure in its caption. and provide the units for the oath terms aiven in the clots 547 Figure 6.7.2-2. page 6-52 Please label the vertical axis. The simulation model acronyms in the figure caption have not been defined in the text at this point. Please make sure they are defined and cited prior to being used the first time and that they are included in the list of references. Note also that the acronym "GP" is referred to as "G&P" elsewhere in the chapter. Please use a consistent acronym for "G&P" throughout the report and appendices. 548 Figure 6.7.2-2.3.4, pages Captions for these figures are inadequate. Please write captions that 6-52. 6-53. and 6-54 indicate the scenarios for which results are depicted and, in the case of Figure 6.7 2-3. indicate what the respective colors represent. Also label and provide units for they axis in Figure 6.7.2-4, and check that all references to the simulation models use acronyms that have previously been defined and are consistent with usage in the rest oflhe report. CHAPTER 8 Median GMC Models: DCPP Sources 549. Section 8.1, page 8-1, Please consider writing a more precise statement of the procedure. numbered item 4 For example, would it be better described as sampling from the multivariate normal distribution defined by the coefficient covariance matrix? 550. Section 8.1, page 8-1, This statement is impossible to parse. Please consider rewriting to item 5 improve its clarity. One option to consider is breaking it into 3 items, the first stating the formation of high-dimensional vectors. each representing the ground motion predictions of a given model for a representative range of predictor variables, the second stating that a metric is defined on that high-dimensional space based on the differences in hazard level between model pairs. and the third stating that the vectors are represented in two dimensions via a (nearly) metric-preserving mapping procedure by means of a Sammon's map. If the term "deaggregation" is retained in the revision of this passage. please indicate what it means in this context (ie .. what was deaggregated and for what set of parameters). 551. Section 8 .1 , page 8-1 , Please specify that it is the two-dimensional space (i.e .* after the item 6 Sammon's mapping procedure is applied) that is discretized. 552. Section 8.2, page 8-1, The statement that weights associated with statistical sampling are 1"' paragraph of shown in green seems a little odd, since none of the weights in the section. 2"" sentence figure are actually shown in green (and in fact there are no green weights in any of the figures in the entire chapter). Please consider revising this and other related statements to avoid confusion. 553. Section 8.2, page 8-1, Weights of the base models are not provided on Figure 8.2-1. 1"' paragraph of Please provide the missing weights and indicate the nature of these section. 2"" sentence weights (i.e. are they subjective weights or weights associated with statistical sampling). 554. Section 8.2, Page 8-The definition of "base model" is given after it is first mentioned on 1. Second Paragraph Line 1 of Page 8-1 . Please move this definition to where it was first of section, Line 2 mentioned. 555. Section 8.2, Page 8-2. 4th line on page Please explain how a HW model was assigned to each base model. 556. Section 8.2, Page 8-Please clarify if the hazard for spectral periods longer than 3 sec are 2. 3rd Paragraph of part of the deliverable and. if yes. please provide a reference to the section (2"c on page). sections where median models for these long period spectra are Line 2 evaluated and integrated into logic trees. 557. Section 8.2, Page 8-Please summarize the meaning of the different branches in the logic 2, 3"' Paragraph of tree in Figure 8.2-2, similarly to what was done for Figure 8.2-1. section (2"" on page), 2nd Sentence 558. Section 8.2, Page 8-The discussion in Section 8.3 suggests that the Tl Team's focus is 2. 3rd Paragraph of on capturing the CBR of median-amplitude predictions. Please section (2"c on page). provide text to clarify that "median ground motion models" is a Last Sentence shorthand for "median amplitude predicted by alternative GMPEs:* 559. Section 8.3, Page 8-Please clarify whether the comment on the Rjb-based formulation is 2, First Paragraph of directed toward the GMPEs (such as BSSA14) or toward the choice section, Line 4 of the distance metric used in the common-form models. 560. Section 8.3, Page 8-Please specify the (lower) bound of the HW effect and how "being 2. First Paragraph of log-normally distributed" is unable to satisfy such a bound section. Line 6 561. Section 8.3, Page 8-Please refer to the specific branch in the Figure 8.2-1 logic tree 2. 1st Paragraph of Section, Sentence when describing weights. 562. Section 8.41, Page Please revise the text to be specific about the quantity to which the 8-2, 1" Paragraph of term range" refers. For example, is it the median amplitude section, First Line predicted by the GMPEs or the GMPEs themselves? 563. Section 8.4.1, Page The terms "common-form models" and "candidate GMPEs" are 8-2, 1st Paragraph of referred to by different names throughout the report and appendices. Section, 1st Sentence Please define a common set of terms for these models and use them consistently throughout the report and appendices and include them in the list of terms. 564. Section 8.4.1, Page The statistical uncertainty analyzed and parametrized by Al-Atik and 8-2, 1" Paragraph of Youngs (2014) was for the NGA-West2 GMPEs and associated section, Lines 4 and 5 datasets. Please comment on whether their results were also applied to non-NGA-West2 GMPEs and, if so. please justify that decision. given that a non-NGA GMPE may use a dataset different from those used by NGA-West2 GMPEs. 565. Section 8.4.1, Page Please revise the text to make it clear that the "+-2 sigma range" is 8-3, 2"" Paragraph of relative to the original candidate GMPEs. section ( 1*1 on page). Line 2 566. Section 8.41, Page Please reference the relevant sections of the report andlor 8-3. 2"d Paragraph of appendices where the process of reducing the range in the common-section ( 1*1 on page). form models is reduced based on comparison with ground-motion 2°0 sentence data. 567. Section 8.4.1, page 8-Please consider rewording this paragraph to indicate that the check 3, paragraph of is done to determine whether the resulting reduced range (not the section (1"' on page), method) is appropriately wide. last sentence 568. Section 8.4.1, Page Please explain the phrase "weighted standard deviation between 8-3, 4** Paragraph of ground motions predicted by two different models .. :*, and explain section (3'" on page), (or provide a reference for) how it can be approximated by the Third Line distance between two points on a Sammon's map. 569. Section 8.4.1, Page Please indicate what the term "deaggregation" means in this context 8-3, 4** Paragraph of (i.e., what was deaggregated and for what set of parameters). section (3'" on page), 5"' line 570. Section 8.4.1, Page It appears that only seven red dots are plotted on Figures 8.4-1 and 8-3, 5** Paragraph of Figure 8.4-2. Please check and correct the text or figures as needed. section (4:" on page). Line 2 571. Section 8.4.1, Page Please consider adding, parenthetically, a brief descrip1ion of 1he 8-3. 61" Paragraph of NGAW2nc database section (5'" on page). 4'" line 572. Section 8.4.1, Page In setting the regions from which GMPEs are selected based on the 8-3. 6111 Paragraph of mean residual, please comment if the use of a horizontal ellipse is section (5'" on page), compatible to the roughly 45-degree inclined pattern of the mean Last Sentence residuals. 573. Section 8.4.1, Page For the upper left plot, please label the contours of 1, 0.3, 0, -0.3, 8-3. 6111 Paragraph of and -1. section (5'" on page). Last Sentence, Figures 8.4-1 and 8.4-? 574. Section 8.41, Page Please comment on the causes of the numerous small patches 8-3. 6111 Paragraph of inside the horizontal ellipse. section (5'" on page). Last Sentence, Figures 8.4-1 and 8.4-2 575. Section 8.4.1, Page Please explain what "likelihood" is shown in the figures (i.e., the 8-4. 91" Paragraph of likelihood with respect to what). section (2"" on page). 1"' line 576. Section 8.41, Page Please explain why a fixed sigma value of 0.65 was used and what 8-4. 91" Paragraph of impact it has on the results. Please also indicate whether .. sigma" in section (2"c on page). this case is the between-event. within-event, or total standard 2°0 line deviation. 577. Section 8.4.1, Page Please explain the significance of a relatively low versus a relative 8-4. 91" Paragraph of high likelihood. section (2"" on page). 4"' line 578. Section 8.4.1, Page Please add additional contour levels to Figures 8.4-1 and 8.4-2 to 8-4, 9'" Paragraph of help show the likelihood value of each GMPE. section (2"" on page). Line 5 579. Section 8.41, Page In this section, the utility of using both the mean residual and the 8-4, 11 '" (last) likelihood in setting the ranges was discussed. Please give a clear Paragraph of section and explicit summary of the roles played by each one in setting the final range. The boundaries shown in Figures 8 4-1 and 8.4-2 seem to suggest an unimportant role of the likelihood. 580. Section 8.4.1, Page 8-4, 11 '" (last) There seems to be a large overlap in information and discussions between this paragraph and the sixth paragraph on Page 8-3 (7'" Paragraph of section paragraph of Section 8.4.1 ). Please consolidate these two paragraphs where appropriate. 581. Section 8.41, page 8-Please replace epistemic" with "epistemic uncertainties." Please 4, 11" (last) also indicate the number of standard deviations used to represent paragraph of section, those uncertainties in the cited figure. line 3 582. Section 8.41, page 8-Please explain why an extrapolation of the candidate GMPEs is 4, 11" (last) found in some cases and not in others. paragraph of section, last sentence 583. Section 8.4.2, Page Please be more specific about the parameter that is being referred 8-4. First Paragraph to. of section. Line 2 584. Section 8.4.2, Page Please give a reference to where a summary of the datasets used in 8-4. 2"1 Paragraph of this section is provided. section, Line 2 585. Section 8.4.2, Page Please provide a figure similar to Figure 8.4-4 for the simulated 8-5, 2"" paragraph of ground-motion data. section (1"1 on page), 1"' line on page 586. Section 8.4.2, Page Please provide references to the sections where such definitions are 8-5. 3'd Paragraph of given. section (2"" on page). Lines 1 and 2 587. Section 8.4.2, Page Please provide the technical basis for the Tl Team's selection of the 8-5, 3'0 Paragraph of (60, 40) mixing between the residual-based and likelihood-based section (2"" on page), weights. Line 4 588. Section 8.4.2, Page Please explain how the "judgments by the GMPE developers" are 8-5, s'* Paragraph of transmitted and maintained by the selected GMPEs. section (4:" on page), Item 3. Line 1 589. Section 8.4.2, Page The concern of non-independent model development has been 8-5, 5** Paragraph of brought up numerous times in this report. In this section, it is used as section (5:" on page), a critical factor in the Tl Team's evaluation of weights assigned to 1"' sentence GMPEs It is thus both helpful and important to have a clear discussion of this concern, including its causes, the magnitude-distance ranges where it is a prevalent issue, and an assessment of the extent of the resulting .. redundancy." Please provide such a discussion. either here or in Chapter 6. 590. Section 8.4.2, Page Please indicate what actual weights the decision of a 3 to 1" 8-5. last paragraph on preference leads to for the empirical and the simulated data sets. page, last sentence 591. Section 8.4.2, page 8-Please replace "cumulative density function .. with "cumulative 6, t* (last) paragraph distribution function." in section. line 2 592. Section 8.4.2, Page Please clarify the meaning of .. range" as used in this sentence. The 8-6. i* (last) likelihood approach seems to render a narrower "shape" (body) than Paragraph in section. other approaches but its range (the difference between the largest Line 5 and the smallest value) is comparable to others. Please be precise when the concept of the center and body of a distribution is invoked. 593. Section 8.4.2, Page Please provide the criteria against which reasonableness is 8-6. i* (last) assessed. Paragraph in section. Line 7 594. Section 8.4.2, Page Please clarify whether this is generally the case for different 8-6, t* (last) scenarios and spectral periods. paragraph in section. 2** to last Sentence 595. Section 8.4.3, page 8-Please clarify that the CDF associated with the selected weights 6. 1"' paragraph of (not the weights themselves) has the property indicated Also section. line 4 indicate that "median" refers to CDF=0.5 on Figures 8.4-5 and 8.4-6. 596. Section 8.4.3, page 8-Please check the values given here for the offset of the medians in 6, 1" paragraph of Figure 8.4-5. For example, are the red (selected weights) and brown section, lines 4 & 5 (GMPEs) 50'" percentile values offset by about 0.1 natural log units (rather than 0.05 as stated). and is the purple (simulations) curve offset from the red by at least 0.15 log units (not 0.1 as stated)? 597. Section 8.4.3, Page Please clarify what is meant by the phrase slope of the CDF" and 8-6, 1" Paragraph of how this slope defines the body of the distribution. section, Last Sentence 598. Section 8.4.3, Page Please explain why curves representing the statistical uncertainties 8-6. 3'd Paragraph of of each original GMPE are not included in these plots (whereas they section. Line 2 are included in previous figures for evaluation of the CBR of the ground motion distribution), and explain the odd shape of the 0.05 quantile curve for M7.5 in Figure 8.4-7. 599. Section 8.4.3, Page Please explain why the 50% value does not always track the median 8-6. 3'd Paragraph of of the predictions of the original GMPE (e.g., see the upper right plot section. Line 2 in Figure 8.4-9). 600. Section 8.4.3, page 8-In Figure 8.4-7, it appears that the selected models do not quite 6, 3"' of envelope the original GMPEs for M 7.5 (e.g., at distance Rx<2), as section, 3' sentence categorically claimed in the text. In fact. the figure gives the impression that M 7 5 is at least as much as exception (to the models enveloping the GMPEs) as is M 5.5, and the text does note the latter exception. Irrespective of whether the exceptions are significant. the apparent inconsistency between the text and the figure is confusing. Please clarify. 601. Section 8.4.3, page 8-Although the reason for the selected M5.5 models not enveloping 6. 3rd paragraph of the original GMPEs is given. please also explain why it is acceptable section. 4'" sentence to allow this underestimate of the range in GMPEs in the model. 602. Section 8.4.3, page 8-6, 3"' paragraph of section, 2"" to last line Please state the rationale for the Tl Team judgment cited here. on page 603. Section 8.4.3, Page Curves from the models with additional epistemic uncertainty are not 8-7. 3'd Paragraph of shown in Figure 8.4-10. Please correct this oversight. section (1"' on page), Line 1 604. Section 8.4.3, page 8-The phrase "all of the models are not enveloped" reads as if none of 7, 3'd paragraph of the models are enveloped. Please rephrase to state" ... not all of the section (1"' on page), models are enveloped due to the sharp ... last 2 lines 605. Section 8.4.3, page 8-Please indicate what "lower" and "higher" center for the simulations 7, 6'" paragraph of is with respect to (e.g., the GMPEs, the Tl Team's weighted average section (4:" on page), model, etc), and whether it refers to ground-motion amplitude or 3'" sentence probability. 606. Section 8.4.3, page 8-Please explain the meaning of "the upper tail of the distribution" in 7, 6'" paragraph of this con1ext, and consider whether i1 is appropriate terminology to section (4'" on page). refer to 1he "center and body" of the upper tail distribution, or whether last sentence this may be an oxymoron. In any case, please define clearly what is meant in this context. 607. Section 8.4.3, Page Please improve the text so it is clear and easier to understand. The 8-7, 7'" Paragraph of revision should also indicate that CDF=0.5 refers to the median of section (5'" on page), the distribution and state what specific "statistics" are computed. Lines 1 to 5: 608. Section 8.4 3. Page 8-7. i" Paragraph of section (5"' on page). Please explain what the "zero residual" is with respect to. Line 8 609. Section 8.4.3, page 8-8, 8'" paragraph of Please no1e that the phrase "distance scaling" is repeated. section ( 1"' on page). line 2 610. Section 8.4.3, Page Please clarify which curve in Figure 8 4-17 corresponds 1o the mean 8-8, 11 '" paragraph of hazard. Also. please revise the categorical statemen1 "larger than the section (4'" on page). hazard from GMPEs" (which appears to be true at low probability but Second Sentence not necessarily at high probability). 611. Section 8.4.3, Page The original GMPEs with statistical uncertainties are an essential 8-8. 11 "' paragraph of part of the overall epistemic uncertainty in the median motion, and section (4'" on page), they are used extensively by the Tl Team in Section 8.4 to set 1he Third Sentence ranges from which representative GMPEs are selected. Given this, please justify why the hazard based on these GMPEs is not included in the checking exercise. 612. Section 8.4.3, Page The average hazard from the GMPEs is not shown in Figure 8.4-17. 8-8, 11 '" paragraph of Please revise this statement to refer to "hazard" instead of mean section (4'" on page), 5"' line hazard. 613. Section 8.4.3, page 8-Here the acronym "1014" is used, whereas in Chapter 6, it was "114". 8, 11'" paragraph of In many of the figures, it is denoted ld14." Please choose one section (4'" on page), acronym and be consis1ent throughout the text and figures. Also note line 7 that 1here is no separate GMPE for ZL 11 (it represents a method for characterizing magnitude saturation). Please describe how ZL11 was used to create a GMPE where the empirical GMPEs are first discussed and assign it a unique acronym to use here and elsewhere throughout the report and appendices. 614. Section 8.5, page 8-9, This section seems to imply that HW effects are no1 involved in the general model generation and representative model selection of Chapter 6. 11 is not clear how this is consistent with the second to last paragraph of Section 6.4.4, where HW effects appear to have been assigned by some form of sampling during the selection of representative models. Please clarify. 615. Section 8.5, Page 8-Please explain what the term "HW3" means. 9, First Paragraph, Second Line 616. Section 8.5, Page 8-Please review the suitability of using the word "range" in the context 9. First Paragraph. of this sentence. Please also indica1e whe1her 1he cen1er and body is Las1 Sentence also captured. 617. Section 8.6, Page 8-The workshop summary (near the bottom of Page G-17) suggests 9, First Paragraph, that directivity has a significant effect on hazard, opposite to what is First sentence stated in this sentence. Furthermore, there is insufficient technical material in the workshop summary 1o allow for a review by the PPRP. Instead of citing the workshop summary, please provide a complete documentation of the hazard sensitivity analysis that supports the conclusion given in this sentence. or provide a reference to the section of the report 1hat does so. 618. Section 8.6, Page 8-Please explain how directivity effects were taken in1o account or 9, 1st Paragraph of provide a specific (chapter. subsection) reference for that Section, Last explanation. Sen1ence 619. Section 8.7, Page 8-There is insufficient technical material in the workshop summary to 10, Firs! Paragraph. allow for a review by the PPRP. Please provide a complete Last Sentence documenta1ion of the hazard sensitivity analysis that supports the conclusion given in this sentence or provide a reference to the section of the report that does so. 620. Section 8.8, page 8-Please see previous comments regarding the list of references for 10 other chapters and appendices for guidance on revising the list of references in this chapter. 621. Table 8.4-1, page 8-Please indica1e in the caption what is meant by the term "SOF." 11 622. Figure 8.2-2, Page 8-Please indicate in 1he caption the meaning of the various branches 13, caption (e.g., what is meant by 1he terms "SIM". "NGAW2DC-MED" etc.). 623. Figure 8.4. 1. Page 8-Please define the units for the color bar and explain the "In" in the 14 and Figure 8.4.2, axis labels. Also please explain why these two plots label the axes Page 15 "In uni1s" whereas what seem 1o be corresponding plo1s in Chapter 9 (Figures 9.1-2a,b and 9.1-3a,b) have their axes labeled "C 1" and C2". If there is no reason for a distinction, please make changes so th;it 1hPv ::irP ronn***'nl. 624. Figure 8.4-3. page 8-Please indicate in the caption and/or legend the number of standard 16 deviations that have been used 1o represent the uncertainties 625. Figures 8 4-5. 8.4-6, In the captions of these figures, "cumulative density function" is page 8-18; and & 8.4-incorrect terminology. Please replace by "cumulative distribution 11, page 8-23 function" 626. Figure 8.4-7, page 8-Please explain the meaning of the term "to1al weights" in the figure 19 caption of this and other similar figure captions. 627. Figure 8.4-12, 8.4-13, Please make the titles on the figure subplots legible. page 8-24; and 8.4-14, page 8-25 CHAPTER 9 Median GMC Models: PVNGS Sources 628. Sections 9.1 Through These sections are very similar to those discussing the DCPP 9.1.3 median GMC models. Please review those Chap1er 8 comments and apply 1he relevant ones to the PVGNS discussion in these sections. Note that some, but not all, of 1hese comments are repeated below. 629. Section 9. 1 , page 9-1 , Please consider writing a more precise s1a1ement of the procedure. numbered item 4 For example, would it be better described as sampling from the multivariate normal distribution defined by the coefficient covariance matrix? 630. Section 9. 1 , page 9-1 , This statement is impossible to parse. Please consider rewriting to item 5 improve its clarity. One option to consider is breaking it into 3 items, the first stating the formation of high-dimensional vectors, each representing the ground motion predictions of a given model for a representative range of predic1or variables. 1he second stating that a metric is defined on that high-dimensional space based on the difference in hazard level between model pairs, and the third stating that the vectors are represented in two dimensions via a (nearly) metric-oreservina maooina orocedure. 631. Section 9. 1 , page 9-1 , Please specify that it is the two-dimensional space (i.e .. after the item 6 Sammon's mapping procedure is applied) that is discretized. 632. Section 9.1.1, page 9-To avoid confusion. having introduced the convention about red and 2. last paragraph of green weights in connection with Figure 9 .1-1 , please consider section noting that Figure 9.1-1 itself does not actually show any statistical-sampling (green) weights. Also, since only one additional figure in the chapter, Figure 9.2-1. actually uses the redfgreen convention. it would be clearer to simply name that figure. rather than saying "In Figure 9.1-1 and subsequent." 633. Section 9.1.2, Page Please describe and show the misfits to the predictions from the 9-2. First Paragraph. original GMPEs by the RR11ro*based and R.iR*based common forms. Line 8 Please discuss whether the weights (0.7, 0.3) assigned 1o the RRuro* based and RJa-based branches, respec1ively, are consistent with 1he misfits. 634. Section 9.1.3.1. Page Please review whether using a term like "distribution" or "center. 9-2. First Paragraph. body. and range" would be more appropriate here than using just the Line 1 term .. range". There are other instances throughout Chapter 9 where the term "range is used. Please also review those instances and revise where appropriate. 635. Section 9.1 3 2. Page Please explain why the Tl Team limits the dataset to events with at 9-5. 2"" paragraph of least 3 recordings per earthquake and whether such a limit is also section ( 1 *1 used in the DCPP evaluation. Paragraph on page), 1"' line on paqe 636. Section 9.1 3 2. Page In Figure 9.1-7, the M 6.6 event appears to have just one recording. 9-5. 2"" paragraph of Please check whether this is an error and revise if needed. section ( 1*1 paragraph on page), 1" sentence on oaae 637. Section 9.1 3 2. Page In the preliminary draft of Chapter 5 (noting that we have not yet 9-5. 2"0 paragraph of seen Rev O for that chapter). in Figure 5.1.3-2. there are a large section ( 1*1 paragraph number of recordings that appear to come from a single M 6.9 on page), 1" sentence normal-faulting event. These data are not included in Figure 9.1-7. on page Please explain why they a re not included in Figure 9. 1-7 and are not used for PVNGS. 638. Section 9.1 3 2. Page Please verify that the 2009 M 6.3 L'Aquila earthquake is included in 9-5. 2"0 paragraph of the EURrv-r.<Fn data set If not. please explain why not. Also. please section ( t*1 paragraph discuss whether all European events in the PEER NGA-West2 on page), last database satisfying the minimum of 3 recordings-per-event sentence requirement are captured in EURpv .... eo-If not, please explain (preferable in Chapter 5) why they were excluded. Conversely. please discuss if all EURrv-MFn events are included in PEER's NGA-West2 database. If not, please explain whey they were excluded. 639. Section 9.1 3.2. page Since weighting is used in several different senses in the chapter. 9-5. 41" paragraph of please consider adding a phrase to clarify that there is no section (3'" on page), reweighting of different style-of-faulting cases in the calculation of the last line mean-residual and likelihood, if that is the meaning that is intended here. 640. Section 9.1 32. Page Please explain what differences in mean residuals mean. The 9-5, 5'" Paragraph of definition given in Section 6.4.5 does not mention the word section (4:" on page), "difference .. Line 3 641. Section 9.1.3.2, Page Please clarify whether the phrase "range of underlying GMPEs" 9-5, 5'" paragraph of means the range of predictions of the median amplitude by the section (4:" on page), underlying GMPEs. Also, please clarify whether the epistemic-Last Sentence uncertainty versions are also used in the evaluation of mixing weights. 642. Section 9.1.3.2, Page Please discuss the Tl Team's assessment of the quality of the 9-6, 7'" paragraph of EURrv-Mm dataset. such as issues related to record screening (for section ( t*1 Paragraph example, removal of low signal-to-noise ratio records and non-free on page). Line 4 field records), record processing, and accuracy of magnitude estimates Also please clarify whether both data quality and data coverage in the key magnitude range are considered in the Tl Team's assessment of relative weights. If the answer is yes, please document Tl Team's evaluations and conclusions. If the answer is no. please provide further justification of the ratio of 3:1. accounting for these two additional considerations. 643. Section 9.1.3.3, page Please correct this term to the correct term .. cumulative distribution 9-6, 1" paragraph of function." section. line 2 644. Section 9.1.3.3, page For the NGA dataset. the residual approach (blue curve) seems to 9-6, 1" paragraph of give a narrower distribution than does the likelihood (orange curve). section. 2"d to last If this is true, it contrasts with the categorical statement to the sentence contrary in the text, which is confusing (even though it doesn't vitiate your main point about the advantages of the weighted model). Please clarify. 645. Section 9.1 3 3. page As in Chapter 8, please correct the phrase "distance scaling and 9-7. i" paragraph of distance scaling". section (4"' on page). line 2 646. Section 9.1.3.3, page 9-8, 9'" paragraph of Please substitute .. and" for the slash between California and Mexico section (2"" on page), line 4 647. Section 9.1.3.3, Page Please explain why the uncertainty in hazard shown in Figure 9. t-9-8. 91" paragraph of t 9a (for Model A) is much larger than the hazard uncertainty shown section (2"" on page). in Figure 9.1-19b (for Model B). _ Lines 5 to 7 648. Section 9.1 3 3. Page Please clarify whether the mean hazard is weighted by the branch 9-8. 1 o'" paragraph of weights. section (3'd Paragraph on page), Line 1 649. Section 9.1 3 3. Page Please include in Figures 9.1-19 and 9.1-20 a curve representing the 9-8. 1 o'" paragraph of average hazard from the original GMPEs. section (3'" Paragraph on oaaet Line 2 650. Section 9. 1.3.3, Page Please explain why the epistemic versions of the original GMPEs 9-8, Last Paragraph of are not included in Figures 9.1-19 and 9.1-20 to help judge the section appropriateness of the selected common-form models in capturing the CBR of the median motion 651. Section 9.1.4, page 9-Please express quantitatively what is meant by "nearby" (where 8. 1" paragraph of there are no known faults). and give the justification forneglecting section. line 1 directivity effects for identified faults outside that region (or specific reference to a report section that provides the justification). 652. Section 9.1 4, Page Please further clarify the statement "The GMPEs capture this 9-8. Line 6 random case" and how it supports the Tl Team's decision to give zero weight to the directivity adjustment branch 653. Section 9.1 5, Page Please indicate that the tectonic regime of the Wells earthquake is 9-9. 1st Paragraph, the same as for the PVNGS site region. but that the tectonic regime 2nd Sentence for the Japan earthquake is not. 654. Section 9.1.5.1. Page Without plotting residuals against the directivity parameter, it is 9-9. 2"0 Paragraph. difficult to form a definite conclusion regarding the existence or the Second Sentence level of the directivity effect. Please either add a plot to support the conclusion or revise the sentence to be less definite. 655. Section 9.1.5.1, page 9-9, 2"" paragraph, Please replace "with respect the" with "with respect to." line 5 656. Section 9.1.5.1, page PGV residuals are not shown in Figures 1-15 and 1-16. According to 9-9, paragraph 2, line Appendix I (Section 1.3.2, Second Paragraph), residuals in Figure I-5 15 are with respect to CY14 only, not to the four NGA-West2 GMPEs Also. residuals shown in Figure 1-16 are averages over six candidate GMPEs Please revise this paragraph to be consistent with Appendix I. 657. Section 9.1.5.1, Page Because the Wells earthquake occurred in the same tectonic regime 9-9, 2nd Paragraph of as the PVNGS site, its ground motion is very relevant to Section, Last understanding the ground motions that might occur at PVNGS from Sentence normal-faulting events. Please state what conclusions were drawn from the observations regarding the validity of the NGA-West2 GMPEs to estimate normal-faulting ground motions at the site. Please also indicate why neither the Bindi et al. (2014) GMPE nor response-spectral values in addition to PGA and PGV were evaluated 658. Section 9.1.5.2. Page Please clarify whether the definition of a complex rupture adopted by 9-9, First Paragraph, the Tl Team is applicable to the case of disjoint ruptures as seen in Line 1 the Fukushima-Hamadori earthquake. 659. Section 9.1 5 2. Page Please justify that the SSRS method is the preferred method for 9-9. First Paragraph. computing ground motion from the Fukushima-Hamadori Line 5 earthquake, given that the evaluation of alternative methods for complex ruptures (Section 6.7 and Sections J.2.2 and J.3.2) does not include disjoint rupture scenarios as seen in the Fukushima-Hamadori earthquake. 660. Section 9.1 52. Page Please explain why the Bindi et al. (2014) GMPE was not evaluated, 9-9. First Paragraph. given that it was one of the candidate GMPEs. Please also indicate if 4:n sentence the Japan regional factors in the NGA-West2 GMPES were used to evaluate the Fukushima-Hamadori. Japan earthquake. 661. Section 9.1 52. Page Please provide a figure similar to Figure 9.1-21 for the Wells 9-9, 1st Paragraph of earthquake. Section, 7th Line 662. Section 9.1.5.2, page Please consider whether an accessible document can be cited 9-9. 3'd paragraph of instead of personal communication, and if not. consider whether the section. line 2 observation cited is of real significance to the assessment. 663. Section 9.1.5.2, page The personal communication cited here entails a claim of local 9-10. 3'd paragraph of stress heterogeneities. without reference to a data source. and a section ( 1*1 on page). "suggestion" about rupture behavior that is difficult to distinguish from lines 9-14 simply an offhand speculation. Please consider first whether this passage is essential to the Tl Team's assessment. If so. please consider whether there is a documentary source for the observation of stress heterogeneity. Also consider whether stating a Tl Team judgment (based on review of the available evidence) that the event cannot be discounted (as an Arizona proxy) might be as authoritative. and more direct. than citing Dr. Stein's undocumented suggestion. 664. Section 9.1 5 2. page Please reference where in the report and/or appendices the 9-10, 4'" paragraph of additional variability gleaned from the evaluation of the Wells and section (2"" on page), Fukushima-Hamadori earthquakes is taken into account. 665. Section 9.2, Page 9-Please explain why the Sammon's mapping approach was not used 10, General to develop the set of models used to estimate ground motions from the distant California and Mexico sources in Regions 1, 2, and 3. Please also include figures to demonstrate the distribution of ground motion values that are implied by the logic-tree model that represents these sources. 666. Section 9.2.1, page 9-The phrases "California/Mexico" and "California -Mexico" should 10, paragraph 1 read "California and Mexico." 667. Section 9.2.4, Page Please specify the applicable distance range of Al-Atik and Youngs 9-11. First Paragraph, (2014) and comment on its applicability to 1he distant California and Line 4: Mexico sources. 668. Section 9.2 41. Page First Paragraph of Section 9.2.4 indicates that this section is about 9-11, 1" Paragraph of epistemic uncertainty in median prediction by the NGA-West2 section, Line 4 GMPEs, whereas this sentence and the remainder of this subsection indicate it's about uncertainty in the path effect. This is very confusing. Please clarify or reorganize as needed. 669. Section 9.2.4.1, page Please cite the relevant appendix section(s) and figure(s) where the 9-11 , 1" paragraph of details are given. section. lines 6-9 670. Section 9.2.4.1, page Please provide a reference and clear explanation for the equation. 9-12, Eqn 9.2-1 671. Section 9.2.5, Page A description of the standard deviation used by the Tl Team to 9-12. Second compute the 51to and 95" values is missing. Please provide such a Paragraph. Line 1 description along with Tl Team's justification for the value used. That description should also clarify why the weights stated at the end of Section 9.2.4.2 and elsewhere in the report differ (slightly) from the 0. 185. 0.63 and 0.185 weights used by Al Atik and Youngs (2014) and recommended by Keefer and Bodily. 672. Section 9.2.6, Page Please provide a reference for the statement that "The distant 9-12. 1st Paragraph of California strike slip sources are located at distances well beyond Section, 1st Line where directivity effects are observed in the empirical data". 673. Section 9.3, page 9-Please see previous comments regarding the list of references for 13, General comment other chapters and appendices for guidance on revising the list of references in this chapter. 674. Figure 9.1-1, page 9-The caption should include the information on the meaning of the 15 red and green weights (as discussed in the text), while noting that there are no statistical (green) weights present in this case. 675. Figure 9.1-2a, Page Please indicate the type of residuals (i.e., between-event, within-9-16, 5th Line of event, total) here and elsewhere throughout the chapter when the Caption term residuals" is used. 676. Figure 9.1-2 & 3, Please provide a label giving the color bar units. or provide that pages 9-16 to 9-19 information in the caption. 677. Figure 9.1-5, page 9-Please rewrite the caption to correct typographical errors and make 21 it more informative. 678. Figures 9.1-8, page 9-The caption in each of these figures should be corrected to read 24; and 9.1-9, page 9-..cumulative distribution function" Please also improve the readability 25 and resolution of these figures and several subsequent ones-they are fuzzy and the numbering is nearly illegible. 679. Figure 9.1-14a-e. All of the influence plots are fuzzy and need improved resolution. pages 9-30 through 9-Plus, the lettering is too small and illegible. The captions could be 34 improved with better explanations of the plots. CHAPTER 14 Hazard Sensitivity 680. General comment Subjective statements such as "main contributing, controlling, significant. small, little impact", etc. are used throughout the chapter to describe results. Please provide a quantitative description of such statements in order to avoid ambiguity. 681. Section 14.1, Page Please provide specific references (i.e., documents or presentations) 14-1, 1st Paragraph, to the hazard sensitivity studies that were provided throughout the 1st Sentence project. 682. Section 14 .1 . page The sensitivity estimates have been invoked at many points in the 14-1. 1"' paragraph report as a rationale for various model simplifications. Therefore. please consider adding a short discussion to further justify the validity of using the earlier SSC models for DCPP and PVNGS as the base case for this purpose (and emphasizing that the older models are used only for that purpose). 683. Section 14.1, page Has the acronym .. NPP" been defined. or even used at all elsewhere 14-1, 2,." paragraph of in the report? Please consider whether it is worth introducing this section. line 3 acronym and defining it here, in lieu of just writing out what it means. 684. Section 14.1, page If the term .. 1ornado plot" has not been defined earlier in 1he report. 14-1 , paragraph 3 of please provide a brief description of i1s form and construction If section. 3'" sentence there was an earlier definition given. please provide a specific section reference. Please also clarify that the y-axis value alluded to at the end of the sentence is that of the hazard curve. not tha1 of the tornado plot i1self. And since not all of the sensi1ivity studies are summarized in Tornado plots (e.g., the source contributions are shown as graphs and deaggregation histograms) please indicate that these other results are shown in other formats. 685. Section 14 .1 . page Please clarify the meaning of "weighted mean" in this context (e.g., 14-1, 3*d paragraph of how are the individual ratio values weighted?). section, line 6 686. Section 14.1. Page This statement implies that the results could be different enough to 14-2. last paragraph be of concern. In this case, please justify why it is sufficient to use of section (1st on the older SSC models for the hazard sensitivi1y studies. Please also page), Last Sentence consider moving this caveat and i1s discussion and justification to Section 14.1 at the beginning of the chapter as recommended in an earlier comment. 687. Section 14.2, page Here, and elsewhere in the report (e.g., Section 14.2, Page 14-4). 14-2, paragraph 1, please add "fault" after Shoreline. Los Osos. San Luis Bay. etc lines 2 & 6 These are formal names and should be spelled out in full. 688. Section 14.2, Page Please indica1e how the fractional contribu1ion of 1he different 14-2, 1st Paragraph of seismic sources to the total mean hazard was determined. If it was Section, 2nd done using deaggregation, please indicate that this is the case and Sen1ence define what deaggregation is and how it is done prior to discussing the results. 689. Section 14.2. Page Please indicate that the deaggregation is done on the mean hazard 14-4, 1st Paragraph here and elsewhere thought the chapter and appendices. on page, 1st Line 690. Section 14.2. Page Please also show the 10'" hazard deaggregation histograms for 14-4. 1st Paragraph completeness. on page, 1st Line 691. Section 14.2. Page Please explain how the deaggregation histograms show that the 14-4. 1st Paragraph hazard at DCPP is controlled by the four local faults when no on page. Last sources are identified in these plots. Sentence 692. Figures 14.2-3 and The entire report addresses hazard on a reference site condition 14.2-4, Pages 14-5 corresponding to Vs30 = 760 m/sec. Because of this. it is confusing and 14-6. Figure to describe the hazard as being for "rock". Please delete the word Captions rock to avoid confusion. 693. Section 14.2.1, Page Please change 14.3-6b to 14.2-6b 14-6, First Paragraph, Last Line 694. Section 14.2, Page Please consider revising the x-axis title in this figure and other 14-8, Figure 14.2-Sa similar figures in Chapter 14 to reflect the normalization of ground-motion ratio discussed in Paragraph 3, Page 14-1. 695. Section 14.2.2, page This sentence would benefit from minor rewording to avoid 14-11, paragraph 2, ambiguity. Please consider whether its meaning could be correctly last line on page rendered by " ... with the weighted average of the phi,, models, including only the central aleatory-variability branch on phi." 696. Section 14.2.2, page Please refer to specific figures when referring to .. the fifth line .. ". 14-12, 4'" paragraph This needs to be done throughout this section (next several of section (3"' on paragraphs) and the remainder of the chapter, as the absence of page). line 3 and specific references leaves some ambiguity as to which tornado plot elsewhere is being cited. 697. Section 14.2.2. Page The sensitivity of the mixture high model appears to be as great as 14-12, t' paragraph many of the other parameters. Please consider revising this of section (6th on statement to better reflect the results shown in the tornado plots. page) 7th Sentence 698. Section 14.3, page Please check to ensure that all of the names and abbreviations that 14-21, abbreviation are listed here are used consistently throughout the report. For lists instance, is Gulf of California referred to as GZ consistently (and not GC) and why is the -F added to CP for Colorado Plateau? This is potentially confusing. because CP is listed here for the Cerro Prieto fault (and it would seem more logical to have the F identifying a fault). Please also reference this list back to a figure. 699. Section 14.3. page Please revise this statement to make it clear whether the 99% 14-21, 1"' sentence contribution to the total hazard is from the background (area?) after bullet 11 sources. the fault sources. or the combination of both. 700. Section 14.3, page 14-22, 1"' paragraph after bullet 26, 1" line Please specify which faults are the distant fault sources. 701. Section 14.3, page Please clarify which modeling choices were made by LCI (2013) and 14-22, 1"' paragraph which ones were made by the Tl Team. Regarding those made by after bullet 26. 2"d and the Tl Team, please justify the choices made with respect to their 3'" sentences implications in identifying hazard-sensitive models and parameters. 702. Section 14.3. page Please be specific and precise about the meaning of the phrase ... a 14-22, 1*1 paragraph pure characteristic earthquake magnitude distribution .. :* as used in after bullet 26, line 7 this context 703. Section 14.3. page Please explain how the source contributions were calculated. 14-22, 2"* paragraph of page after bulle1ed items, 1" sentence 704. Section 14.3. page Please justify the use of the specific sigma value of 0.65. 14-22, 2"* paragraph of page after bulleted items, 4'" line 705. Section 14.3. page Please add the missing word greater" before than" in the phrase 14-22, 2"' paragraph "For ground motion values than 0.1 g." of page after bulleted items, line 7 706. Section 14.3, page If this paragraph is intended 1o be a summary of the results in 14-24, 1"' paragraph Figures 14.3-1 and 14.3-2, please explain how one reconciles the on page categorical statements in this paragraph with the period-dependent resul1s in 1he figures. For example, Figure 14.3-2 appears to indicate that $BR sources dominate 0.5 Hz hazard at levels exceeding about 0. 15 g, which appears to contradict the categorical statement that "distant fault sources are the dominant contributor to hazard at lower spectral frequencies:' Shouldn't the statements in this paragraph be conditional on something (e.g., the probability of exceedance range of interest)? Please also indicate whether this apparent contradiction is related to the observation made later in Section 14.3, Page 14-25, top 2 lines on page. 707. Section 14.3, page Please quantify what is meant by "local small"' and .. distant large** in 14-24, 2"' paragraph on page, 2"d and 3*d this context. sentence 708. Section 14.3. Page Please also show the 1ff" mean annual hazard deaggregation 14-24, 2nd Paragraph histograms for completeness. on page, 4th Sentence 709. Section 14.3. page This observation may be related to the above comment made about 14-25, top 2 lines on Section 14.3, Page 14-24, 1" paragraph on page. page 710. Section 14.3.1. page The phrase "there are not known active faults .. is at best an awkward 14-27, 2"* paragraph construction. and potentially ambiguous. Please reword for clarity. of section ( 1 ** on page), line 1 at top of page. 711. Section 14.3. 1, page Please provide reference to the report section where the neglect of 14-27, 2"' paragraph directivity effects was justified. of section ( 1" on page), top 2 lines on page 712. Section 14.3.1. page Please indicate what the statement "'little impact" is compared to. 14-27, 3*d paragraph of section (2"0 on page), 713. Section 14.3.1. page t4-27, 4'" paragraph of section (3"' on Please refer to specific figures that are related to this discussion. page) 714. Section 14.3.1, page The explanation of the greater range at lower hazard level in terms 14-27, 4'" paragraph of depth scaling requires some amplification. Please provide some of section (3'" on further explanatory remarks. page), lines 9 and to 715. Section 14.3. 1, page Please add the missing word *ior" in the phrase** .. to the hazard and 14-27, 4'" paragraph produce a floor the hazard estimate ... " of section (3"' on page), line 15 716. Section 14.3. 1, page Please revise this statement to clarify its meaning (i.e .. are the t4-27, 4" paragraph of section (3'" on values shown really "fractional" contributions?) page), last sentence 717. Section 14.3.1. page t4-27, 5" paragraph of section (4'" on Please refer to specific figures that are related to this discussion. page), general comment 718. Section 14.3.1. page Please consider rewording this sentence so as not to categorize the 14-27, 5'" paragraph GMPE prior estimate as a "dataset." The subject here is really of section (4'" on sensitivity to elements of the weighting scheme for the median base page), 1"' sentence models (Figure 9.1-5), only some of which are datasets. 719. Section 14.3.2. page Please provide a reference to the report section where the neglect of 14-31 , 1 *1 paragraph directivity effects was justified. of section. 2"0 sentence 720. Section 14.3.2, page Please refer to specific figures that are related to this discussion t 4-32, first 3 paragraphs on page 721. Section 14.3.2, page Please clarify where in the report the additional epistemic 14-32, 4'" paragraph uncertainty in the magnitude scaling is discussed and which node in of section (3"' on Figure 9.2-1 models this uncertainty. aaae), line 1 722. Section 14.3.2. page It should be clear at this point that the different model sensitivities 14-32, 4" paragraph are with respect to a common base case (i.e .. the denominator) and: of section (3'" on therefore. all represent changes in the numerator. Please remove page), line 3 this reference to the numerator in order to avoid confusion that these results are somehow different than the previous ones. 723. Section 14.3.2, page This sentence is poorly written (including seemingly redundant 14-32, 4'" paragraph constructions such as "approach application" and "in with"). Please of section (3"' on rewrite this sentence for clarity and precision. Also, please check page), lines 7 & 8 whether the "i.e." in the parenthetical note correctly conveys the intended meaning (ie .. the "i.e." implies some sort of equivalence between the preceding clause and the parenthetical observation. which mav not be intended). 724. Section 14.3.3, Page Please do not use a slash (e.g .. in the term the PhisslPhisr-R) unless 14-36, 1st Paragraph, it is intended to represent a ratio here and throughout the chapter. 2nd Line 725. Section 14.3.3. Page Please explain why the BSSA 14 GM PE was used for the sigma 14-36, 1st Paragraph, sensitivity studies and the CB14 GMPE was used for the median 6th Line sensitivity studies. 726. Section 14.3.3. Page Please provide, in the text, the spectral frequencies that are 14-36, 2nd associated with Figures 14.3-9 and 14.3-10. Paragraph, 1st Line 727. Section 14.3.3, Page This is the first time that the values of ratios are given. Please be 14-36, 2nd consistent in either providing such ratios or not providing them Paragraph, 4th Line throughout the chapter. If the ratios are not provided, the subjective statements describing these ratios should be quantified (see General Comment on this chapter). 728. Section 14.3.4 page Please reference specific figures related to this discussion. 14-41 , 3'" paragraph of section (1"' on aaae) 729. Section 14.3.5. page Please check whether "0.5 Hz .. should be "5.0 Hz." 14-46, 3*d paragraph of section ( 1" on page), line 1 730. Section 14.3.5, page Please describe the three models that are shown for the "with path" 14-46, 4:* paragraph and without path" rows in Figures 14.3-13a, 14.3-13b, 14.3-14a, and of section (2"" on 14.3-14b. page), 1*1 sentence 731. Section 14.3.5, page Please consider whether the intended meaning of this sentence 14-46, 4:* paragraph of section (2"" on would be better conveyed by .. because of' rather than "based on " page), line 4 732. Section 14.3.5. page This statement does not seem to be consistent with the figures. 14-46, 5:* paragraph Please revise this statement to better reflect the results shown in the of section (3"' on tornado plots. page), 6:* sentence 733. Figure 14 3-13b. page The caption reads correctly that this plot is for 5 hz (as stated in the 14-48 text) but the header of the figure reads O 5 Hz. Furthermore, the plot looks identical to Figure 14.3-14b. Please make sure this is the correct plot and either correct the header or replace it with the correct plot. 734. Section 14.3.7, Page Use of the term distribution is confusing. Please consider replacing 14-54, 1st Paragraph, "distribution" with sensitivity. 9th Line 735. Section 14.3.7. Page The NGA-West2 models only show significant sensitivity at 0.5 Hz, 14-54, 1st Paragraph, so this general statement is confusing. Please consider deleting this 101" Line sentence and making statements regarding the impact of these models separately for the two frequencies. 736. Section 14.3.7, Page Use of the term uncertainty is confusing. Please consider replacing 14-55, (1st uncertainty" with sensitivity". Paragraph, 3rd Line 737. Section 14.4, Page Please see previous comments regarding the list of references for 14-58, General other chapters and appendices for guidance on revising the list of references in this chapter. APPENDIX H Evaluation of Common Form Models 738. General The format of the appendix is different from that of the report and other appendices. Please reformat the appendix to be consistent with the rest of the report. 739. Chapter 1. General The text is very cryptic and contains a myriad of terms and acronyms. making it comprehensible to only those that have a good understanding of the topic. Please expand the text to be more descriptive and ensure that all of the used terms and acronyms have been clearly defined in the main report prior to referencing the appendix or. if not. that they are defined in the appendix the first time they are used. 740. Chapter 1. Tables 1.1 The table captions should specify units for the ground motion levels. and 1.2, page 2 741. Chapter 1, Section Please indicate what the GMPEs are used for See also 1st Line of 1.1, Page 1, 4th 5th Paragraph. Paragraph, 1st Line 742. Chapter 1, Section Please replace "(2014)" with "(2014a.b)" in the Akkar et al (2014) 1.1, Page 1, 4th reference to indicate that both the original manuscript and the Paragraph, 2nd Bullet erratum were published in the same year and add the reference to the erratum in the list of references. See also 3rd Bullet in 5th Paragraph. 743. Chapter 1 , Section Zhao and Lu (2011) do not present a GMPE, but rather an approach 1.1, Page 1, 4th to magnitude-scaling at large magnitudes. Please define a new Paragraph, 8th Bullet GMPE that incorporates the proposed magnitude-scaling in Zhao and Lu (2011) and identify it by a unique acronym. 744. Chapter 1, Section Please replace "(2014)" with "(2014a.b)" in the Bindi et al. (2014) 1.1, Page 1, 5th reference to indicate that both the original manuscript and the Paragraph, 3rd Bullet erratum were published in the same year and add the reference to the erratum in the list of references. 745. Chapter 1. Section Please add the missing word not" in the phrase "but do 1. 1.1, page 3. paragraph 1 . 2"d to incorporate". last line 746. Chapter 1. Section Please justify the basis for the weights assigned to the median and 1. 1. 1, Page 3, 2nd plustminus uncertainty of the GMPEs. Paragraph, 7th Line 747. Chapter 1, Section Please define the meaning of the term "total weights". 1. 1. 1, Page 3, 3rd Paragraph, 1st Line 748. Chapter 1, Section Please avoid the use of slashes (e.g .. in widthlrange) unless it is 1.1.1, Page 3, 3rd intended to represent a ratio. Paragraph, 3rd Line 749. Chapter 1, Section Please define the meaning of the term "all weights" and how it differs 1.1.1. Page 3. 7th from the term "total weights". Paragraph, 2nd Line 750. Chapter 1. Section Please reference the logic tree that documents the weights that are 1. 1. 1, Page 3, 8th assigned to Models A and B for PVNGS. Paragraph, 2nd Line 751. Chapter 1. Section Please update the references to the various datasets to use the 1. 1.1, page 3. 81" terminology introduced in Chapter 5. and reference the appropriate paragraph. line 5 section and table from that chapter. If the term "weighted NGA dataser is not explained in Chapter 5, please explain that term here. 752. Chapter 1, Section Please clarify what "those" refers to in what appears to be part of an 1.2, Page 5, 1st incomplete phrase. Paragraph, 1st Line 753. Chapter 1 , Section Please provide references to the simulation methods of EXSIM, 1.2, Page 5, 1st Graves and Pitarka (i.e., G&P), and SDSU. Paragraph, 3rd Line 754. Chapter 1 , Section Please clarify what "models" are being referred to 1.2, Page 5, 1st Paragraph. 5th Sentence 755. Chapter 1. Page 7. Please ensure that all of the references are cited in the text and are Bibliography complete. and add missing references identified in the text. 756. Chapter 2. General Please provide a short introduction to the figures that are presented in the report. 757. Chapter 2, Section Please provide uni1s for the legend bars in the figures showing the 2.1.2 Sammon's maps. 758. Chapter 2. Section Please explain why the distribution of hazard curves for the selected 2.1.4 models covers a smaller range of hazard than that for 1he 2000 curves and what impac1 that has on the final results. 759. Section 2.1.4. Page To help visually compare the hazard distribution from the selected 53, Figure 2.69 model to the distribution from all 2000 sampled models. please add the 5%. 50%. and 95% curves of 1he latter distribution to both plots. Also please increase the size of each plot for ease of viewing. 760. Chapter 2. Section Please define the acronyms in the legend that are used to describe 2.1.5 the GDF curves in the figures. Also please change "cumulative density function** to "cumulative distribution function" in all captions. here and 1hroughout the report. 761. Section 2.1 6, Page Please explain what causes the ramp-up of the lower black curve on 106. Figure 2.202 this figure and other figures. 762. Section 2 .1 . 7, Page Please explain what causes the ramp-up of the lower red curve on 107, Figure 2.208 this and other figures. 763. Section 2.1.81.4.7, Please explain why, a1 Rx= -1, the GMPE distribution is much more Pages 137 and 140, sensitive 1o the value of F (s1yle-of-faulting flag) than the Model A Figure 2.272 vs. distribution is. Figure 2.281 764. Chapter 3. General Please see comments for Chapter 2. 765. Chapter 4, General Please see comments for Chapter 2. 766. Chapter 5. General Please see comments for Chap1er 2. APPENDIX I Wells (NV) Earthquake 767. Section 1.1, Page 1-1. Please provide a reference for 1he statement that "The tectonic 2nd Paragraph. 1st setting. magnitude. and focal mechanism of this earthquake are all Sentence consistent with the seismic sources in the Southern Basin and Range that contribute significantly to the hazard at high frequencies at the Palo Verde Nuclear Generating Station (PVNGS)"'. 768. Section 1.1, page 1-1. The acronym" NGA-W2" was given as "NGA-West2 .. elsewhere in 2"' paragraph, line 5 the report. Please standardize the terminology and acronyms throughout the report. 769. Section 1.2.1. Page 1-Please provide a summary of instrument response, sampling lime 1. 1" Paragraph of interval. and possible limitations of the USTA recordings for use in section. Line 7 the comparison with GMPEs described in Section 13. 770. Section 1.2.1, page I-US Transportable Array is abbreviated "USTA" here. while 1. 1"' paragraph, line 7 elsewhere it is referred to as 'Transportable Array" and abbreviated as "TA". Please standardize the terminology and acronyms throughout the report. 771. Section 1.2.1, page I-Please clarify the meaning of the term "temporary stations". If these 1. 1" paragraph, line 8 temporary stations are the USTA stations. please indicate such in the text. 772. Section 1.2.1, page I-Please add either a period or semicolon following "100km". 1. 1"' paragraph, last 2 lines 773. Section 1.2.2, Page I-Please clarify that the Wills and Clahan (2006) relationships 2, 2nd Paragraph, 1st between geologic units and Vs30 are based on California data and Line geology and might not be appropriate for Nevada. Please also discuss the potential significance of this assumption on the results 774. Section 1.2.2, Page I-Please provide units for the Vs30 values of 600 and 750 m/s. 2. 2nd Paragraph. 1st Sentence 775. Section 1.2.2, Page I-Please explain why there is no proxy Vs30 value for Station M 12A 2, 2nd Paragraph, 2nd shown in Figure 1-2. Later in the text it is noted that this station Sentence clipped and was not used, but that information is not available at the point in the appendix where this figure is referenced. 776. Section 1.2.3, page I-The record for station N12A also looks clipped in Figure 1-3. Please 2. 1 "' paragraph of consider whether that is the case. and if so. whether it is appropriate section. line 7 to comment on that record as well, in order to be consistent. 777. Section 1.2.3, Page I-Please explain why a focal mechanism from UCB was used rather 2, 1st Paragraph of than one from a more local source (e.g., 1he UNR Seismological Section, Last Laboratory), or from the study of Dreger et al. (2011) or the USGS Sentence NEIC. 778. Section 1.3.2, Page I-Please add the references for Abrahamson et al. (2014), Boore et al 3, 1st Paragraph of (2014), Campbell and Bozorgnia (2014), Chiou and Youngs (2014), Section, 2nd and Idriss (2014) to the list of references. Sentence 779. Section 1.3.2, Page I-Please replace "2013 (ASB13)" with "2014a,b (ASB14)" and add the 3, 1st Paragraph of Akkar et al. (2014a,b) original manuscript and erratum to the list of Section, 2nd references. Sentence 780. Section 1.3.2. Page 1-Please replace "2013 (BIN13)" with "2014a,b (Bi14)" and add the 3. 1st Paragraph of Bindi et al. (2014a.b) original manuscript and erratum 1o the list of Section, 2nd references. Sentence 781. Sec1ion 1.3.2, Page 1-The statement that the NGA models are a better short-period fit than 3. 3*d paragraph. last the Euro models does not seem correct without a more specific line s1atement of 1he period range (e.g .. it appears that the absolute value of the average residual is similar between NGA and European datasets up to a period of -0.05 seconds). Please formulate the conclusion more precisely. 782. Section 1.3.2. Page 1-This paragraph summarizes the observations of the analysis given in 3, 4th Paragraph of Appendix I, but does not provide conclusions whether the Wells Section earthquake data indicate tha1 there is a po1ential issue with 1he applicability of 1he NGA-West2 or European GMPES to the greater Arizona region. Please provide conclusions based on the observed comparison shown in this appendix and demonstrate, perhaps statistically. whether the Wells ground-motion data is consistent with the empirical GMPEs over the period range of interest 783. Section 1.4, Page 1-3 Please revise the list of references to include missing references and 1o update those references 1hat have incomple1e informa1ion 784. Figures 1.1 1o 1.14 Please provide missing or more meaningful figure captions. 785. Figure 1.15, Page I-Please indicate that these residuals were calculated with respect to 19, Caption the CY14 GMPE. 786. Figures 1.16, Page I-Please indica1e that the mean residuals are calcula1ed with respect 20, Caption to all 7 sites in the upper plot and provide a description of what is shown in the lower plot. APPENDIX J Forward Finite Fault Simulations for SWUS 787. General There are a lot of analyses being described in this appendix, some of which are attributed to unspecified authors or by the pronouns "I", "we", "our", etc. Please indicate who performed the analyses (e.g., the Tl Team or some o1her Resource or Proponen1 Expert) and avoid the use of pronouns, which refer to unspecified authors of the appendix. 788. General comment This appendix deviates stylistically from others, in that some subsections are given headers but left unnumbered. For example, within Section J.2.2. on Page J-10 there is a heading .. Scenario 1: Hosgri that is unnumbered, whereas following convention established in other chapters this should have become Section J.2.2.1. Please edit the chapter for uniformity of style with the rest of the reoort 789. Section J .1 , page J-1 . Please include a reference describing the SCEC Broadband Line 1 Platform. For example. a suitable paper would be that published (SRL early online publication for Jan 2015 issue). by Maechling et al. Also please define acronyms (such as SCEC) the first lime they are used, here and throughout the appendix. 790. Section j. 1, page J-1, For the sake of parallelism of construction. "and extending GMPE" Line 4 should read "and to extend GMPE." 791. Section J.1, Page J-1, Please include additional text in this sentence to reflect the use of Line 5 simulated data by the Tl Team in Chapter 8 to select and assign weights to the selec1ed models for DCPP (Figure 8.2-2). Also. please add a summary, including tables, of the fault parameters used to obtain the Chapter 8 simulated data, or reference the section where such a summary is provided. 792. Section J.1.1, Please explain whether the validation process uses a performance General measure that specifically evaluates the capabili1y of simulation methods in modeling hanging wall effects. If not, please explain the Tl Team's basis for trusting the HW factor derived from the simulations. 793. Section J.1.1, page J-The acronym "G&P" is given as "GP" elsewhere. Please use a 1. 1 "' paragraph of consisten1 acronym throughout the report. section, line 7 794. Section J.1.1, page J-In addition to the cited report, there is a peer-reviewed publication in 1, 1" paragraph of (SRL early online publication for Jan 2015 issue) by Dreger et al, section line 8 describing the BBP methods review, which could usefully be referenced here. The individual BBP methods each have individual peer-reviewed papers in the same SRL issue, and these should be cited as well. 795. Section J.1.1, Page J-There were issues attempting to open the URL from the link given in 1. 1st Paragraph of the appendix, although it worked when pasted into Microsoft ln1erne1 Section, Last Explorer. Please correct this link or indicate that it should be pasted Sen1ence into a web browser. 796. Section J.1.1, Page J-The pseudo spectral acceleration (PSA) referred to here is also 1. 2nd Paragraph of referred to as RotD50 spectra elsewhere in the appendix. Please Section, 2nd Line choose a single 1erm for PSA and use it consistently throughout 1he appendix and, preferably, the report and other appendices for con sistencv. 797. Section J.1.1, Page J-Please provide references for the NGA-West1 project and the 1. 2nd Paragraph of specific NGA-West1 GMPEs that were used for the Part B validation. Section, 3rd Line 798. Section J.1.1, Page J-Please provide a reference and/or link to the SCEC BBP workshop 2. 1"' Paragraph on proceedings. page, 1st Line 799. Section J.1.1, Page J-Please indicate the specific "appendix" that is referred to. 2, 1" Paragraph on page, last line 800. Section J.1.1, Page J-This excerp1 from the panel report needs clarification as indicated in 2, 2"" paragraph on subsequent comments, even if that requires a format different from a page, general verbatim quote. If one or more direct excerpts are nonetheless comment retained. please use quota1ion marks and indentation 1o distinguish paragraph-length quotations from the main text, and quotation marks to distinguish brief ones. 801. Section J.1.1, Page J-Please clarify this statement by replacing .. residual .. with "value of the 2, 2nd Paragraph on residual". page, 2nd Line 802. Section J.1.1, Page J-Please clarify the specific meaning of "performance" here and in 2. 2nd Paragraph on Item 4. page, 7th Line 803. Section J.1.1, Page J-Please clarify the meaning of the phrase "equally combining the 2. 2nd Paragraph on absolute value of mean bias with the mean of the absolute value of page. 2nd Numbered the bias". which is somewhat confusing as stated Item 804. Section J.1.1, Page J-Please explain why the period range 0.01 to 3 sec is deemed 2. 2nd Paragraph on acceptable for validating the finite-fault simulation methods. page, Last Line 805. Section J.1.1, page J-Please consider whether the parenthetical comment is necessary, 2, 3*d paragraph on and if so. whether the point being made could be clarified. The point page, line 3 of the corresponding comment in the SCEC report was only to place the 0.35 natural log unit threshold in context, by comparing it to the amplitude effect of a 0.1 unit magnitude shift in the limit of large distance and long period. 806. Section J.1.1, Page J-Please provide a reference for the SCEC review report." 2, 3rd Paragraph on page, 6th Line 807. Section J.1.1, Page J-Please explain why the specific ranges of distances and magnitudes 2. 4th Paragraph on were selected for the Part B validation. page, 2nd Line 808. Section J.1.1, page J-2, 4'" paragraph on page, 2"d sentence Please replace "NGS-West 1" with "NGA-West1". 809. Section J.1.1, Page J-Please define these acronyms the first time they are used and 2, 4th Paragraph, 2nd replace the year with only the last two letters of the year to be Sentence consistent with how these acronyms are defined elsewhere throughout the report and appendices. 810. Section J.1.1, page J-The description of the upper and lower acceptance thresholds is 2, 4'" paragraph on ambiguous. Please provide a more precise description. page, 3'" and 4:n sentences 811. Section J.1.1, Page J-Please indicate what "appendix" is being referred to. 3, 1st Paragraph on page, Last Line 812. Section J.1.1, Page J-Please provide the numerical values of the validation magnitude 3. 2nd Paragraph on range. page, 3rd Line 813. Figure J.1.1-1:, Page The bias threshold of 0.69 In units is not discussed in the text at this J-4. Caption. 3rd Line point in the appendix. Please define why this threshold was selected and how it is used when the figure is first discussed in the text. 814. Figure J. 1. 1-2:, Page The stated factor of 1.15 applies to extending the maximum value J-5, Caption, 4th Line but not the minimum value. Please indicate what factor (less than one) was used to extend the minimum value. 815. Section J.21, Page J-Please define the terms and units in the magnitude-area scaling 6, 1st Paragraph of relationship of Leonard (2010). section, Last Line 816. Section J.21, Page J-Please replace "Graves and Pitarka" with "G&P .. to be consistent 6. 2nd Paragraph of with the use of this acronym elsewhere throughout the report and section. 2nd Line appendices and use it consistently throughout the appendix, which also sometimes refers to G&P as GP. 817. Section J.21. page J-Please correct the extraneous words "A of' at the beginning of the 6. paragraph 2 of last sentence of the section. section. line 4 818. Figure J.2.1-1, Page Please also show the M7 scenario on this plot and indicate what dip J-7 angle is used to make the plot. 819. Section J.21, Page J-Please explain why there is no dip variation for the M 7 scenario. 8. Table J.2.1-1 820. Section J.2.2, page J-Please provide a reference to the report section where the precise 9. paragraph 1. line 1 definition of a "complex" rupture scenario, as used in this project, is given. 821. Section J.2.2, page J-Please consider whether the reference to personal communication is 9, paragraph 1, line 2 appropriate in this context, or whether ii would be sufficient to note that the simplified scenarios were developed by the SSC project. 822. Section J.2.2, page J-The first sentence of the paragraph states that two complex 9. paragraph 1. line 4 scenarios were considered. but the list on this line contains three. including a Hosgri-Shoreline scenario that appears to be a splay scenario. Please check and make any appropriate corrections. 823. Section J.2.2, Page J-Please define the parameters "L" and .. W" the first time they are 9, 1" Paragraph, 6th used. Line 824. Section J.2.2, page J-The final sentence of the paragraph cites a personal communication 9. paragraph 1. last 2 for the approach to scaling the simulation parameters. Please rewrite lines this sentence to make it clearer that the Tl Team made the judgment to follow this approach. in light of its technical assessment of the alternatives and its consideration of the specific ways in which the simulations are used. 825. Section J.2.2, page J-Please add the missing word .. that" in the phrase .. except for." 9, of section, 2" line after equations 826. Section J.2.2, page J-Please clarify the intended meaning of the phrase "shortening a 9. 2"d paragraph of fault". If, for example, it means shortening it relative to the length section, 5'" and 6:" assigned in the SSC. that should be made explicit. Also clarify the lines after the intended meaning of the word "lowered" with respect to the northern equations endpoint [of the fault]. 827. Section J.2.2, page J-This sentence has several issues that should be corrected. (1) 10, paragraph of Please revise the awkward and ungrammatical (in this context) section (1*1 on page). construction "instead of attempting to predict realistic ground 1*1 sentence on page motion." (2) Please consider whether .. realistic ground motion" is the right contrast to draw with "relative" ground motion (e.g., would "absolute .. ground motion level be more appropriate?). (3) The caution against using the simulations for absolute ground motion levels appears to contradict the use of simulated ground motions in Chapter 8 to evaluate the common-form models. Please rewrite this sentence to clarify the intended meaning and resolve the apparent contradiction. 828. Section J.2.2, page J-Later in this section, when splay scenarios are discussed, the 10, heading of 41h corresponding headings start with .. Splay Scenario " The structure of paragraph of section the discussion would be more parallel and clearer if this heading (line 4 on page) were changed to "Complex Scenario 1 : Hosgri-Los Osos:* Please also include a section number for this and other similar subsection headings in the appendix, for easy reference and stylistic consistency with the other sections of the report. 829. Figure 2.2-1. Page J-Please show the surface projection of the inferred rupture plane of 10 the dipping reverse fault(s) in this and similar figures in the appendix. 830. Section J.2.2, page J-Please indicate (e.g .. in the table caption) which (Hosgri or Los 10, Table J.2.2-1 Osos) is segment 1 and which is segment 2. 831. Section J.2.2, page J-Later in this section. when splay scenarios are discussed. the 11, heading at top of equivalent headings start with "Splay Scenario." The structure of the page discussion would be more parallel and clearer if this heading were changed to "Complex Scenario 2: Shoreline-San Luis Bay." 832. Section J.2.2, Page J-The length of the Shoreline fault plotted in this figure seems to be 11, Figure J.2.2-2 and much shorter than the length listed in Table J.22-2. Please check Table J2.2.-2 and revise as needed. 833. Section J.2.2, page J-Please indicate (e.g., in the table caption) which (Shoreline or San 11, Table J.2.2-2 Luis Bay) is segment 1 and which is segment 2. 834. Section J.2.3, page J-If the rupture scenarios were defined by the DCPP SSC Tl Team. 11, 1'1 paragraph, 1sl2 please indicate that explicitly. lines 835. Section J.2.3, page J-Please justify why the Tl Team made the judgment to select 12, 2,." paragraph of scenarios consistent with the Leonard relationships (e.g., is there a section (1"1 on page), connection with the way the models were validated?). lines 4 & 5 836. Section J.2.3, page J-Please clarify which research goals were facilitated by the 12, paragraph of modifications described and how the results ultimately feed into the section (1"' on page), GMC model. Last 2 sentences of paragraph 837. Section J.2.3, page J-Please check whether the intended meaning would be better 12, 4'" paragraph of conveyed by using "each case" in place of "both cases." section. line 1 838. Section J.2.3, page J-Please explain the meaning of1he phrase scaled that slip by 30%," 12, 4'" paragraph of and give the justification for selecting the vaue 30%. section (3'" on page), 3'" and 4*h sentences 839. Section J.2.3, page J-Please clarify whether .. this slip" refers to the slip on the secondary 12, 4'" paragraph of fault. section (3'd on page). 5'h line 840. Section J.2.3, page J-Please check whether this line should read "Los Osos-San Luis Bay 12, 5'" paragraph of splay scenario" and correct if appropriate. section on page). Line 1 841. Section J.2.3, page J-This sentence is confusing because of the ambiguity of the word 12, 5'" paragraph of "meet" in this context (i.e .. the word does not indicate which fault is section (3'd on page). cut off by the "meeting"). Please consider whether the intended Line 5 meaning would be better indicated if meet" were replaced by "abut". 842. Section J.2.3, Page J-Please explain how exactly the process described in this sentence 13, 1st Paragraph, was done, which is somewhat confusing as stated. 2nd Sentence 843. Section J.2.3, page J-This sentence repeats nearly verbatim that of Section J.2.2, Page J-13, paragraph 8 of 10. 3*d paragraph of section. and the same comment applies and is section (4"' on page) repeated here. This sentence has several issues that should be corrected. (1) Please revise the awkward and ungrammatical (in 1his context) construction "instead of attempting to predict realistic ground motion." (2) Please consider whether "realistic ground motion" is the right contrast to draw with "relative" ground motion (e.g., would "absolute" ground motion level be more appropriate?). (3) The caution against using the simulations for absolute ground motion levels appears to contradict the use of simulated ground motions in Chapter 8 to evaluate the common-form models. Please rewrite this sentence to clarify the intended meaning and resolve the apparent contradiction. 844. Section J.2.3, page J-The phrase "Complex Scenario Z' should read "Splay Scenario 2". 14, heading following Table J.2.3-1 845. Section J.2.3, page J-"Shoreline-San Luis Bay splay" should read "Los Osos-San Luis Bay 14, 1 *1 line after the splay". Please correct. heading 846. Section J.3, Page J-Please indicate if "spectra" refers to Fourier amplitude spectra or 15, 1st Paragraph, 4th PSA spectra or both and whether the RotD50 component applies to Bullet Item, Last Line PSA here and elsewhere throughout the appendix. Note a previous comment to use a consistent definition for the PSA spectral values referenced throughout the appendix and to define the term "RotD50" the first time it is used. 847. Section J.3.2, Page J-Please explain what an SRF file is the first time the term is used. 16, Second Paragraph. Line 3 (Item 2) 848. Section J.3.2, Page J-Please explain what each of the "two pieces" of the $RF file 16, 3rd Numbered represents. Item 849. Section J.3.2, page J-Please use some alternative language in place of the personal 16, paragraph 3 of pronoun "I" in order to better reflect the Tl Team's collective section ( 1*1 paragraph intellectual ownership of the model and maintain stylistic consistency after the list), Line 2 throughout the report. 850. Section J.3.2, page J-The meaning of this sentence is not clear. Please rewrite it to clarify 16, 5'" paragraph of how ExSim solutions for the component segments were combined. If section (last the GP and SDSU simulations were applied in some way as part of paragraph on page). the ExSim procedure. the explanation should clarify what "properties" 2"* sentence GP and SDSU provided. and how those properties were matched by the ExSim procedure. 851. Section J.3.2, page J-The time delay appears to represent the delay between initial 16 5'" paragraph of rupture on the initial segment and arrival of that rupture at the section (last on page). junction of the fault segments. If that is the case. the relevant velocity last sentence would be the rupture velocity, not the S wave velocity Vs. If this reasoning is correct, please modify the notation "Vs" to be more appropriate for representing a rupture velocity instead of the wavespeed. If it is not. please clarify. In either event, please rewrite this sentence to be explicit about what was done. That is, instead of using the ambiguous qualifier based off', state explicitly what was calculated to obtain the delay time. 852. Figure J.3.2-1. Page Please describe the meaning of the colored shading on these and J-17 similar plots in 1he appendix. 853. Section J.3.2, page J-The use of quotation marks on factors" is not appropriate (it is not a 17, 6'" paragraph of meta-reference to the word "factors"), and because the quantities section ( 1*1 on page). defined here are used repeatedly in an important role in this section. line4 the clarity would be significantly improved if they were given a distinctive name, with the name then used consistently throughout the discussion that follows. 854. Section J.3.2, page J-The factors obtained from rules for defining GMPE input parameters 17, 6'" paragraph of appear to be different quantities than the factors defined earlier in the section ( 1*1 paragraph paragraph. and the use of the same term "factor" for both (especially on page), line 9 since the term "factor" is not distinctive to begin with) is a source of confusion. Please clarify the discussion later in the chapter by giving the ratios obtained from these GMPE rules a distinctive name. different from that used for the simulation ratios 855. Section J.3.2, page J-The characterization of the process as "already quite convoluted" is 18, 7'" paragraph of redundant. Please consider deleting that phrase. In fact, the entire section (1*' on page). sentence could be replaced by beginning the subsequent sentence 1 *1 sentence with "For complex scenarios with both a strike-slip and reverse component. it was required." 856. Section J.3.2, page J-Please elaborate on what "separated" means in this context and how 18, 7'" paragraph of section (1*' on page). this separation is conducted and the results verified last sentence 857. Section J.3.2, page J-Please explain what this paragraph contributes to the description or 18, 8'" paragraph evaluation of the GMC model or delete it. on page) 858. Figure J.3.3-1, Page Please define the acronyms used in the legend of the plot. J-19, Caption 859. Section J.3.3, page J-This sentence is similar to that of Section J.3.2, Page J-16 5:" 20, 3'" paragraph of paragraph of section (last on page). last sentence. and the same section (1*1 on page). comment is repeated here. The time delay appears to represent the line 6 delay between initial rupture on the initial segment and arrival of that rupture at the junction of the fault segments. If that is the case, the relevant velocity would be the rupture velocity. not the S wave velocity Vs. If this reasoning is correct. please modify the notation "Vs" to be more appropriate for representing a rupture velocity instead of the wavespeed. If it is not, please clarify. In either event, please rewrite this sentence to be explicit about what was done. That is. instead of using the ambiguous qualifier "based off'. state explicitly what was calculated to obtain the delay time. 860. Section J.3.3, page J-Please remove the inappropriate quotes from "factors" (but see 21, 4" paragraph of previous comment recommending use of a more distinctive section ( 1*1 on page). terminology). and correct the redundancy in the phrase "we 1"' and lines on computed factors computed for." oaae 861. Section J.3.2, Page J-If "plant site" refers to the "DCPP site", please replace the former 21 , 1st Paragraph, with the latter. If the intended meaning of the phrase is different. 2nd Line please supply the intended meaning. 862. Section J.4, Page J-Please avoid the use of the term "proponent models" here and 21, Section Heading elsewhere throughout the appendix, which can be confused with the term proponent models and/or methods proposed by Proponent Experts, as defined in the SSHAC guidelines. 863. Section J.4, Page J-Since much of the text in this section is virtually the same as the text 21, General in Section 6.7, please refer to the comments on Section 6.7 for revising the similar text and figure captions in this section. 864. Section J.4, Page J-Please clarify whether this always leads to an increase in ground 22, 2,." Paragraph of motion. section, Line 2 865. Section J.41, page J-Please consider whether the intent of this line would be better 23, 1*1 paragraph. line conveyed by the phrase "Four methods were evaluated for 1 computing" in place of the phrase "four methods were used to comoute." 866. Section J.4.1, page J-Please define the variables used in the equation. and, for 23, 2,." paragraph of consistency with other parts of the report, change "Sa" to "PSA." section, unnumbered equation 867. Section J.41, page J-The quotation marks on average" are inappropriate. If the word 23, paragraph of "average" without quotes doesn't communicate the intended section, 3'" line after meaning, please use a word that does (e.g .. "representative"). the equation 868. Section J.41, page J-24, 4" paragraph of section (1*1 on page). Please define the variable 'R" line 2 869. Section J.4.1, page J-Please define the variables used in the equation and clarify the 24, 4'" paragraph of nature of the summation. section (1*1 on page). unnumbered equation 870. Section J.41, page J-Please consider whether the intent of this sentence would be better 24, 1 *1 line after the conveyed by the phrase "The GMPEs are then applied using" equation instead of the phrase 'The GMPEs use the .. , since the latter could be misinterpreted to imply that the subsequent part of the sentence is a defining feature of the GMPEs. 871. Section J.4.1, page J-The meaning of this line would be clearer if the sentence began by 24, last paragraph of indicating explicitly that the method applies the GMPEs with the section, 1" line predictor variables as defined in the balance of the sentence. Please clarifv this line. 872. Section J.4.2, Page J-Please revise the sentence so that it is clear that **so degree" refers 24, 2r* paragraph of to the fault dip. section. line 1 873. Section J.4.2, page J-Please specify that "method., refers to "ground motion simulation 25, paragraph 4 of method." The distinction is necessary because four methods for section (last on page). assigning GMPE predictors are also discussed and need to be line 1 differentiated from the numerical ground motion simulation methods. 874. Section J.4.2, page J-Please clarify this line by specifying that the spectra are obtained 25, paragraph 4 of from the GMPEs using each of the four different methods for section (last on page). assigning predictor variables. line 2 875. Figure J.4.2-1. Page Please correct the acronyms in the plot legends to conform with J-26 those used elsewhere throughout the report and appendices (i.e., "ASK 14" instead of .. ASK'13"). Also, please check the accuracy of the "grey., curve that has a nearly "flat" zone from 0.5 to 1 Hz and. if correct, explain why this GMPE is used given such strange behavior. 876. Section J.4.2, page J-There are no gray lines in Figure J.4.2-3, nor are the colors of the 26, paragraph 5 of section (1*1 on page). dots explained. Please correct line 2 877. Section J.4.2, page J-As noted in an earlier comment. the discussion of complex and splay 26, paragraph 5 of adjustments would be easier to follow if the simulation factors and section (1"1 on page), GMPE factors had different, distinctive names used consistently line 2 throughout the chapter. Furthermore. the GMPE factors have not been explicitly defined. and although the meaning can be inferred from the context pretty well, ii would be clearer if they were explicitly defined when the concept was first introduced. Please consider introducing better terminology and more explicit definitions for these "factors". 878. Section J.4.2, page J-Figure J 4 2-3 does not appear to show what is claimed. maybe 26, paragraph 6 of because the gray lines mentioned in the text and caption are not section (2"c on page). visible. line 2 879. Figure J.4.2-3, Page There are four GMPE methods but six differently colored dots J-28 Please indicate what the different colored dots represent both here and in similar plots in the appendix. 880. Section J.4.2, page J-The statement that the magnitude is based only on the area of the 29, 9'" paragraph of Los Osos fault in Method 1 for the Hosgri-Los Osos scenario is section (t*1 on page). confusing. The problem is that the statement can be misinterpreted last sentence to suggest that the magnitude of the scenario changes depending upon the method of ground motion calculation. However, what actually changes is just the predictor variable M that is input to the GMPE. Please keep this distinction clear in the discussion. 881. Section J.4.2, page J-Please revise this sentence so that it is clear "70 degree" refers to 29, 10'" paragraph of the fault dip. section (2"' on page), Line 1 882. Section J.4.2, page J-This figure citation appears to be in error, as this is no Figure J.22-29, 10'" paragraph of 3. Please check whether the citation should be to Figure J.2.2-2 and section (2"c on page), make the appropriate correction. Line 2 883. Section J.4.2, page J-Please check whether the cited table should be J.2.2-2 instead of 29, 10 paragraph of J 2.2-3. section (2"" on page), Line 3 884. Section J.4.2, page J-The word "one" just before the comma is ambiguous. Please clarify 29, 11'" paragraph of whether the meaning is all periods except for one period" (in which section (last on page), case indicate which one), or if it is "all periods except for T= 1 last line on page second." 885. Section J.42, page J-The gray lines are not visible in Figure J.4.2-6, nor are the symbols 30, 13'" paragraph of explained. Please correct this. section (2"" on page). Line 1 886. Section J.4.2, Page J-If this sentence is intended to refer only to Methods 2. 3. and 4, but 32, 2nd Paragraph, not Method 1, please replace the phrase each of these methods" Last Sentence with "each of Methods 2, 3, and 4." 887. Section J.4.2, Page J-Please expand this paragraph to summarize quantitatively the 33, 1st Paragraph on justification for accepting Method 1 for the complex scenarios. page, 1st Sentence 888. Section J.4.3, page J-Please cite a published report or journal article for the observation 34, 4** paragraph of that the GMPEs have stronger distance saturation than the ExSim section (t*' on page). model Then the result mentioned here (regarding ExSim peak line 5 amplitudes) can be stated as a consequence of that fact (perhaps one pointed out by Dr. Atkinson to the Tl Team), rather than something to be taken purely on the authority of an unpublished comment by Dr. Atkinson. 889. Section J.4.3, Page J-Please reference the figure where the comparison referred to in this 35, 2nd Paragraph on sentence is shown. page, 1st Line 890. Section J.4.3, Page J-Please explain quantitatively the basis for the statement that 37, 2nd Paragraph on "Overall, GMPE Method 1 RotD50 spectra provide the best page, Last Sentence agreement with the simulation results". 891. Section J.4.3, page J-Please reference the figure where the comparison referred to in this 39, 1*1 paragraph on sentence is shown. page, 1*1 line 892. Section J.4.3, page J-In Figure J.4.3-6. the colors are not explained nor are the panels 39, 1*1 paragraph on labeled nor explained in the caption. Please correct this. page, last line 893. Section J.51, Page J-The magnitude ranges specified in this sentence disagree with those 41, Last Sentence of specified elsewhere in the report and also disagree with those section described in the publications of ASK 14 and CB14. Please revise as needed. 894. Section J.5.2, Page J-Please clarify that only the NGA-West2 HW terms are used and that 41, 3rd Paragraph of these terms are applied to the footwall model developed from the Section, 1st Line simulations. 895. Section J.5.2, page J-Please distinguish whether the processing described in this 41 , 3'" paragraph of sentence refers to the GMPE estimates or the simulation estimates. section. 2"d sentence Also clarify that the phrase "extent of the rupture plane" means extent of the surface projection of the rupture plane. 896. Section J.5.2, page J-Please either provide the functional form used or a reference to the 41 , 3'" paragraph of report section or publication where ii is provided. section, 3'" sentence 897. Section J.5.2, Page J-Instead of stating that the comparisons are similar, please include 41, 3rd Paragraph of the comparisons with CB14 and CY14 on Figure J.5.2-2 to show the Section, Last robustness of the NGA-West2 GMPE HW terms. Sentence 898. Section J.5.2, Page J-The SDSU simulations do not show a HW effect at M5.5 and M6.0. 41, 4th Paragraph of This would imply that there is some uncertainty in whether there is a Section, 2nd HW effect at small magnitudes. Please discuss how this uncertainty Sentence is factored into the HW model or reference where in the report such a discussion is provided. 899. Section J.5.2.3, Page Instead of stating that the results are similar. please include the J-42, 1st Paragraph, results from CB14 to show that the results are similar. 2nd Sentence 900. Section J.5.2, page J-The statement that the distance taper is small is ambiguous and 42, 5'" paragraph of confusing. It appears, in fact, that the distance tapering factor is near section (2"" on page), unity, not near zero. Please clarify. 2** to last sentence 901. Section J.5 2 3. Page Please also clarify that the development of the HW term for the GMC J-42, 3rd Paragraph, model is given in Appendix K. Last Sentence 902. Section J.5.2, page J-Please reconsider the categorical statement made here that the M 42, 6" paragraph of taper of the NGA-West2 GMPEs is too severe. There are several section (3'" on page). such GMPEs Do you mean to refer to all of them. to all that use 2"" sentence Rrup as the distance predictor, or to just ASK14 and CB14? Why would CY 14 be judged as too severely tapered, given the results in Figure J.5.2-4? Please clarify. 903. Figure J.5.2-2, Page Please expand this figure caption to better describe the plots that J-44 are shown in the figure. 904. Figure J.5.2-3. Page Please indicate that the colors refer to the plus symbols shown on J-44 this and similar plots in the appendix. 905. Section J.6.1, page J-The language used here could imply that 1D models are not yet fully 47, 1*1 paragraph of implemented. Please clarify by revising this line. section. line 1 906. Section J.6 t, Page J-Stochastic simulation methods often employ a set of site-47, 1st Paragraph, 4th amplification factors that are developed from a 1 D velocity and Sentence density crustal structure. typically using the Quarter-Wavelength Method. Please clarify whether or not that is the case with the versions of EXSIM, G&P and SDSU that are available on the BBP, all of which use a stochastic method (though only for the computation of ground motion at frequencies above 1 Hz in the case of SDSU and G&P). If it is, please indicate what crustal structure is used and how similar it is to the velocity models described in this section. 907. Section J.6.1, Page J-Please indicate the referenced features on the velocity profiles 47, 2nd Paragraph, shown in Figure J.6.1-1. 1st and 2nd Numbered Items 908. Section J.6.1, page J-Please indicate whether the recording at PKO was affected by any 47, 3'" paragraph of significant. known 30 wave propagation effects section. line 2 909. Section J.6 t, Page J-Please provide units for the values 286, 93, and 62. 47, 3rd Paragraph, 3rd Line 910. Section J.6 t, page J-The cited figure shows synthetic ground motion, not velocity models, 4 7, 3'" paragraph of so "GIL7 velocity model" should read "synthetics calculated with the section, line 7 1D GIL? velocity model" 911. Section J.6.1, page J-Please provide a reference (either to a publication or to a report 47, 3'" paragraph of section) supporting the asserted appropriateness of the GIL 7 velocity section. line 8 model for the central coast ranges. 912. Section J.6.1, Page J-Please define the term "PL type wave" the first time it is used. or cite 48, 1st Paragraph on a reference where the term is defined. page, 2nd Sentence 913. Section J.6 t, page J-This paragraph (and to some extent the preceding one as well) 48, 2,." paragraph on seems rather awkward and its purpose unclear. The discussion page appears to be treating GIL7-based synthetics as targets for the BBP Norcal-based simulations to match. giving the GIL7-based synthetics similar status to that of the observed waveforms. Why would not all of the models deserve comparison with the observations on an equal footing? Please consider whether it would be less confusing. and more to the point. to simply state that, on balance. simulated waveforms based on the BBP Norcal profile agree with the key features of the observed waveforms at least as well as those based on alternative available 1 D models. 914. Section J.61, Page J-Please avoid 1he use of 1he subjective term very good agreement" 48, 2nd Paragraph, and instead provide a quantitative measure of the agreement and 4th Line why that measure of agreement is acceptable. For example. it appears from Figure J.6.1-3 that the synthetic seismogram amplitudes are as much as a factor of 2 higher than the observations. 915. Section J.61, page J-The clause beginning with "although" confuses the issue, making it 48, 3'" paragraph on harder to understand the point being made. The use of the 1 D model page, 1" sentence is either justified by the tests cited or it is not The fact that there could be an even better option for future use is interesting and worth mentioning as a final comment, but it does not address the question of whether the current use of the 1 D models is justified. Please rewrite this sentence to summarize the Tl Team evaluation of the model actually being applied. Ideas (like 3D modeling) for future improvement may be offered, but in a way that makes it clear that the evaluation is not contingent on those improvements. 916. Section J.6.2, page J-Please provide a specific reference to the discussion or presentation 50, 1" paragraph of where the stated "remark" from Workshop 2 can be found, and section, line 1 indicate the period range implied by long-period" in this context. 917. Section J.6.2, Page J-Please clarify if the comparison is between simulated ground 50, 1st Paragraph, motions or between simulated and observed ground motions. 2nd Sentence 918. Section J.6.2, page J-The line described parenthetically as red appears as a black line in 50, 1" paragraph of Figure J.6.2-1. Please correct this description so that the text and section, line 7 figure are consistent. 919. Section J.6.2, page J-Please clarify that the comparison is between simulated ground 51, 3'" paragraph of motion and synthetic slip models used to compute those ground section (2"" on page) motions, if that is the case. If that is not the correct interpretation, please explain. 920. Section J.6.2, page J-51 , 3'" paragraph of Please explain what the word "maximum" refers to. section (2"' on page). Line 2 921. Section J.6.2, page J-This paragraph and some of the subsequent discussion is difficult to 51, 4" paragraph of follow. Please consider prefacing it with some clear statement of the section on page) purpose of the analysis, and following it with a clear summary statement. For example, if the purpose is to assess (using numerical simulations} whether near-fault. long-period ground motion amplitudes mirror the empirically-observed high variability of static slip values, it would help if that were stated explicitly. If the conclusion is that ground motions do not mirror that high variability, because they are better correlated with broader spatial averages of slip (which are less variable than point values} than they are with nearest-point slip values, it would be useful to summarize that conclusion in explicit terms. 922. Section J.6.2, page J-Please consider whether the intended meaning of this line would be 51, 4'" paragraph of clearer if the phrase "from nearby shallow regions of the fault" were section (3'" on page), restated as "from slip on shallow portions of the fault that are nearby, line 3 but not necessarily nearest. to the site." or some similar phrase that highlights the essential idea that the nearest point on the fault does not necessarily dominate the ground motion amplitude. 923. Section J.6.2, Page J-Please explain the meaning of the term "radiation sensitivity" and 51, 3rd Paragraph on define the terms "FP" and "FN" the first time they are used. page, 7th Line 924. Section J.6.2, Page J-Please clarify that the "given site" is the location of LCN. 51, 3rd Paragraph on page, Last 2 Lines 925. Section J.6.2, page J-This paragraph is difficult to parse and its purpose is not very clear. 51, 5" paragraph of Please rewrite to make that purpose clearer, and also please state section (4'h on page). what is meant by the phrase "pseudo station." 926. Section J.6.2, page J-Please include plots of variation of static displacement, peak FP and 51, 7 paragraph of FN displacement, and SD with the nearest surface slip. section (6"' on page). Line 1 927. Section J.6.2, Page J-Please clarify what "correlations" are being referred to in this 51, 6th Paragraph on statement. page, 3rd Line 928. Section J.6.2, Page J-Please avoid the use of the subjective statement "quite good" and 51, 6th Paragraph on page, 51" line replace it with a quantitative measure of the goodness. 929. Section J.6.2, page J-This sentence is ambiguous. One possible interpretation is that the 51 , 7'" paragraph of static displacement and FP peak displacement correlate better with section (6'h on page). local fault slip than does the FN peak displacement. An alternative 3'" sentence interpretation is to replace "than does" with than with". Please make changes to resolve this ambiguity. 930. Section J.6.2, page J-There is a reference here to "local fault slip." Please distinguish, 51 , 7 paragraph of here and elsewhere in this section, between point-wise (or nearest-section (6:" on page), point) values of local fault slip versus localized averages. The last line on page distinction is important because there is no real question that some sort of local average is going to correlate with low-frequency ground motion. The point of the section appears to be to indicate just how localized that control is. and therefore how much variability it introduces. 931. Section J.6.2, Page J-Please clarify what the "geometric mean" is taken with respect to 60, 1st Paragraph on page. 1st Line 932. Section J.6.2, Page J-Please delete the subjective word "well". 60, 1st Paragraph on page. 4th Line 933. Section J.6.2, Page J-Please complete the phrase "and that the range of the simulated 60, 1st Paragraph on motions". page, Last Line 934. Section J.6.2, page J-Please resolve the ambiguity of the phrase "1 Os of source 60, s** paragraph of realizations," which can be read as "tO's of source realizations" or section (t*1 on page). "10 seconds of source realizations." last line on page 935. Section J.6.2, Page J-Please explain why the capture of the variability along the fault by 61, 2nd Paragraph, the 50 realizations is expected. Last Sentence 936. Section J.7, page J-Please ensure that all of the references that are cited are in the list 61 & J-62 of references and that all of the references are complete with up-to-date information. For example, please update reference items 2, 8, 10 & t3 with complete publication information, and the missing references for Goulet et al. (20t4} and Dreger et al. (2014) that were cited at the end of Section J.1.1. 937. Figure J.2.2-2, page Please add to the caption that "Shoreline" and "San Luis Bay" label J-11 the rupture segments modeled in the simulation, and indicate their relationships to the Shoreline Fault and San Luis Bay Fault, respectively (e.g .. that they are simplified representations inspired by the Hosgri-Shoreline splay scenario?). 938. Figure J.4.2-2. Page Please add a label to the y-axis and indicate in the figure caption J-26 that this figure is for complex rupture Scenario 1. This request also applies to Figures J.4 2-5. J.4.3-2, and J 4 3-5. 939. Figure J.4.2-3, page The gray lines in this plot are not visible. and the meanings of the J-28 colors are not indicated (the latter also applies to Figure J.4.2-6, J.4.3-3, and J.4.3-6). Please correct. 940. Figure J.4.2-6, page The gray lines in this plot are not visible. and meanings of the colors J-32 are not explained. Please correct. 941. Figure J.5.2-3 & These figures use a different color scheme for the 3 simulations than Figure J.5.2-4, pages do earlier figures, which is confusing. Please use the same color J-45 & J-46 scheme for all figures for clarity. 942. Figure J.4.3-2, page Please label the plot axes. J-35: Figure J.4.3-5, Page J-39; and Figure J.6.1-1. page J-48 943. Figures J.6.1-2 and Please indicate the recording station in the caption. J.6.1-3 944. Figures J.6 2-5 Please explain the use of the factor Y:i, and why it is absent in Figures J.6 2-6 and J.6 2-7. Also please define the symbols and lines in the plot and reword the caption lo be more meaningful in this and similar figures in the appendix. APPENDIX K Hanging Wall Model 945. General There are many parameters, terms, and acronyms used throughout the appendix without first being defined. As a reiteration of previous comments on various chapters and appendices in this report. please ensure that all of the parameters, terms, and acronyms used in this appendix are defined in a list prior to their use. Otherwise, they will need to be defined the first time they are used in each chapter and appendix. 946. General All of the figure captions are short and cryptic. Please expand the figure captions to comple1ely describe all of 1he curves shown on the plot and the values of any variables that were used to plot them. 947. Sec1ion Kt. Page K-Please explain the meaning of the term "HW facto( the first time it is 1, 1st Paragraph of used (e.g., indicate how is it calculated from each GMPE). Please Section, 1st Line also indicate who derived the HW fac1or model in place of the statement "The HW fac1or model was derived". 948. Page K-1. First Please include a brief summary of the ranges of magnitude and Ztor Paragraph and site locations (Rx) for which HW effects are of importance to the GMC model. 949. Section K.1, Page K-The dip of the rupture plane is a fifth aspect of the ASK14 and CB14 1. 1st Paragraph of HW terms 1hat has been overlooked. Please mention 1he dip of the Sec1ion, 2nd Line rupture plane as an additional aspec1of1he ASK14 and CB14 HW terms. 950. Sec1ion Kt. page K-Please replace "rupture place" with "rupture plane," or, perhaps 1, 1" paragraph, line 3 more precisely, wi1h "rupture surface." 951. Sec1ion Kt. Page K-Please define the term taper," as it applies in this context, the first 1. 1st Paragraph of time it is used. Section, 5th Line 952. Sec1ion Kt. Page K-Please indicate which of the five aspects of 1he HW 1erms of ASK14 1. 1st Paragraph of and CB14 are also present in 1he CY14 HW term before describing Sec1ion, 7th Line the differences in this latter term. 953. Section K.1, Page K-Please insert the missing comma after 1he word "magnitude" at the 1, 1" Paragraph, Line end of line 7. 7 954. Sec1ion K. 1.1, Page Please avoid the use of the subjective term "significant" and instead K-1, 1st Paragraph of provide a quantitative metric to describe these differences. Please Section, 6th Sentence also summarize the observed differences among the HW terms of the NGA-West2 GMPEs. 955. Sec1ion K.1.1, Page Please indicate if the HW factors given by Eq. (K-1) are arithmetic or K-1. Eq. (K-t) logarithmic and exercise care when referring to this factor elsewhere throughout the appendix by indicating if it is the multiplicative factor or the log factor that is being referenced. 956. Section K.1.1, Page Please justify the assumption that the HW effec1 is largely geometric K-2, 1st Paragraph on and show why. based on this assumption. that the surface projection page. 2nd Sentence of the rupture plane is directly related to the cosine of the dip. 957. Section K. 1. t. page Please add a comment noting that the formulation alluded to was K-2, 1" paragraph of section (1"1 on page), 3'" sentence on page introduced to fit numerical simulations, if that is the case. 958. Section K 1.1, Page Please briefly describe the HW study and model developed by K-2. 1st Paragraph. Donahue and Abrahamson (2014). 5th Line 959. Section K 1.1, page Please clarify the purpose of the expression "with the effect based K-2, 1" paragraph of on the GMPE." It seems to be covered already by the text in the section ( 1"' on page), beginning of this sentence. Line 7 960. Section K.1.1, page Please justify the Tl Team's decision to neglect HW effects at K-2. 1st paragraph of periods longer than 3 seconds, in light of the interpretation of Chang section ( 1*1 on page). et al. (2004, BSSA, vol 94, p. 2186) that there are large HW effects 2"* to last sentence at long period (T = 2s and 4s) for the 1999 Chi Chi earthquake. This may entail showing plots of long-period (T>3s) residuals for the ChiChi earthquake computed with respect to the candidate GMPEs. 961. Section K 1. 1. Page Please define the meaning of "central model (e.g., is it the median K-2. 1st Paragraph on or mean HW factor. which depends on whether the model is on the page. 12th Line factor itself or the log of the factor). 962. Section K.1.1, page Please check whether this line should say '"K-1 through K-4." and K-2, 1" paragraph of section (1"1 on page). correct if appropriate. last line 963. Section K.1.1, Page Please define the term "base model" the first time it is used. K-2, 2nd Paragraph, 1st Line 964. Section K 1. 1. Page Please further explain (here or preferably in Chapter 6) the necessity K-2, Second for equal-probability sampling of the HW factor models, in lieu of Paragraph of section other variance-preserving sampling schemes (un-equally weighted) (and 2°0 on page) such as those widely used to represent the epistemic uncertainty of other PSHA inputs. 965. Section K 1.1, Page Please clarify whether it is the arithmetic HW factor or the log HW K-2. 2nd Paragraph, factor that is assumed to be normally distributed. 3rd Line 966. Section K.1.1, Page Please explain the meaning of '"fitted model K-2. 2nd Paragraph, 5th Line 967. Section K 1. 1. page Please define the term "epsilon" the first time it is used. K-2, 2"" paragraph of section and page, line 7 968. Section K 1.1, Page Please explain how the "probability weighted mean epsilons" were K-2. 2nd Paragraph, calculated. 7th Line 969. Section K. 1.1, Page Please explain why "equally weighted factors were used when they K-2. 2nd Paragraph, were derived from different probability ranges of a normal 12th Line distribution. 970. Section K 1.1, page Please check whether this sentence should say "K-1 through K-4," K-2. 2"" paragraph of and correct if necessary. section (2"c on page). 2"' to last sentence 971. Section K. 1.1, Page Please avoid the use of the subjective term "good" and provide a K-2, 2nd Paragraph, quantitative metric for describing the goodness of the observed 14th Line comparison. This applies to this instance and several other instances throughout the appendix where "good" is used to describe the goodness of a comparison. 972. Section K. 1.1, Page Please explain why it is acceptable for some of the GMPE HW K-2, 2nd Paragraph, factors to fall outside the bounds of the five proposed HW models. 14th Line 973. Section K1.2. Page Please summarize the analysis from Appendix J to the extent K-2 necessary to form a readable and understandable review of the Tl Team's treatment of the magnitude taper issue. If. in that treatment. the magnitude-dependence carried implicitly by Eq K-1 is deemed reasonable based on the good agreement with simulated HW effects at M 5 5. please state this explicitly. 974. Section K 1.2. Page Other reasons why the ASK14 and CB14 HW models applied a K-2, 1st Paragraph of magnitude taper to make the HW factor go to zero at M5.5 was the Section, 2nd Line lack of any empirical data or numerical simulations to support a HW effect at smaller magnitudes. Please include these reasons in support the NGA-West2 developers "judgment" that is stated as the reason for the taper. 975. Section K. 1.2, page Please give a specific magnitude range for the phrase "moderate K-2, 1" paragraph, magnitudes". Line 3 976. Section K 1.2. Page The ground motion simulations described in Appendix J showed that K-2, 1st Paragraph of one of the three simulation models (SDSU) did not predict strong HW Section, 2nd effects at small magnitudes. except at relatively small depths (e.g., Sentence Ztor = 2.5 km) or relatively small dips (e.g .. dip= 30 degrees). Please indicate how this uncertainty is incorporated in the HW factor model presented in this appendix. 977. Section K.1.3, page Please indicate that the site angles of 90 and 0 degrees mentioned K-3, 3" and 4'" in these sentences are measured relative to fault strike. sentences of section 978. Section K 1.3. page Please explain how the assertion that CB14 and CY14 "allow for a K-3, lines 4-6 on page smoother transition as a function of location around the rupture is consistent with the fact that (according to Figure K-5) CB14 has a step as Rjb approaches zero along the strike direction This step behavior actually appears to be a sharper transition than that of any of the other HW models in Figure K-5, and would seem inconsistent with this assertion 979. Section K.1.3, Page Please avoid the use of the subjective term "well." which in this case K-3. 1st Paragraph. can be deleted without impacting the statement 6th Line 980. Section K.1.3, Page Please indicate that the proposed Rjb taper model given by Eq. (K-K-3, 1st Paragraph, 2) is shown in Figure K-5. Eq. (K-2) 981. Section K.1.4, Page Please avoid the use of the subjective term significant" and instead K-3. t st Paragraph of provide a quantitative metric to describe the observed differences in Section, 3rd Line the trends. 982. Section K. 1.4, Page Please indicate that the proposed Ztor taper model given by Eq. (K-K-3, 1st Paragraph of 3) is shown in Figure K-6 Please also show the equation for the Section, Eq. (K-3) complete HW factor model that combines all three equations for completeness (also note whether the complete model is the arithmetic or log value of the HW factor. 983. Section K.2, page K-Please provide a specific reference to the section(s) of Appendix J 3. 1"' paragraph of where the hanging wall analysis is presented. section, 1" sentence 984. Section K.2, Page K-Please provide and discuss the development of the equation that 3. 1st Paragraph of was used to define the footwall simulations. Section, 3rd Line 985. Section K.2, Page K-Please clarify who did the simulations described as "were 3. 1st Paragraph of simulated". Section, 5th Sentence 986. Section K.2, Page K-Please provide similar plots to those in Figure (K-11) for a range of 4, 1st Paragraph, 2nd magnitudes. dips, and depths to fully document the comparison with Sentence the simulations, or revise Figures (K-1) to (K-10) to show all five HW factor models instead of only the central model. 987. Section K.2, Page K-4 Please ensure that all of the references cited in the text are included in the list of references and that all of the references provide a complete description of the publication (e.g., volume and page numbers). 988. Table K-t. Page K-4 Please include all five of the C1 values that represent the five HW factor models in Table K-1. 989. Table K-t. Page K-4 The "Central" and "Range of Models" shown in this figure have not been discussed the first time this figure is referenced in the text. Please provide an explanation of these curves as well as an explanation that the curves and GMPE estimates are for Ztor = 0 in the figure caption of this figure and in Figures (K-2) through (K-4). 990. Figures K-1. K-2, K-3, Please make changes to the legend to reflect that the dashed lines and K-4 do not show the "range .. of the models, but rather are the five individual models used to approximate the distribution of the modeled HW factors. 991. Figure K-5. Page K-Please check the CB14 HW factor for the increasing Ry curve, which 10 for Rx = O should have a positive HW factor that decays with distance (i.e .. it is only for Rx< O that CB14 predicts no HW effects). 992. Figures K-5 and K-6 Please change "rx" in the figure legend to "Rx" to be consistent with the main text 993. Figure K-7 Please explain in the caption the meaning of the solid black curve in each plot and provide references to the three simulation models that are defined by their acronyms in this and similar figures in the appendix. Please also indicate that the SWUS HW term (called HW factor model in the text) that is plotted in this and all similar figures as the red line is the central model. APPENDIX 0 Comparison of Hazard: Original GMPEs versus Common Functional Forms 994. General Although the plots shown in this appendix show that the range of hazard is captured, ii would be useful to show a comparison of the hazard curves from the GMPEs with the 5th, 50th, and 95th percentile hazard curves from the common-form models in order to also show that the body and not just the range of the hazard is also captured. Please provide such plots in addition to those that are already shown for the DCPP and PVNGS models. 995. Section 0. 1, page 0-The reference to a "simplified" seismic source model is confusing. 1, 2"" of This sentence refers to it as the DCPP SSC model used in Chapter section. 2" sentence 14, and the First Paragraph on Page 14-1 states that "the previously published Seismic Source Characterization (SSC) models for the two sites were used ... without reference to any simplification. Please review and revise the entire paragraph as needed to clarify. 996. Section 0.1. page 0-Without a comma after the words "closest sources", this sentence is 1. 2"d of (almost) ambiguous as written It could mean that the source model section. 2" sentence comprises the closest sources. inasmuch as those are the significant contributors. But it could easily be misread to mean that, among all sources that are significant contributors, the model singles out only the closest ones If the former interpretation is intended. please clarify that by means of a comma. 997. Section 0.2. General Except for the addition of the hazard curve from GK14, Section 0.2 appears to provide the same information as provided in Section 8.4.3 (and Figures 8 4-17 and 8.4-18). Please clarify what is new in Section 0.2. compared to Section 8.4.3. 998. Section 0.2, Page 0-Please see comments given in other chapters and appendices 1, 1st Paragraph of regarding suggested revisions to the bullet list of references to these Section, 3rd Line eight GMPEs. 999. Section 0.2. Page 0-Please provide the reference to sections of the report where the 2. 2"d paragraph on common-form models are described. page (1" sentence after the bulleted list) 1000. Section 0.2, Page 0-Please indicate who calculated the common-form model hazard 2, 3rd Paragraph, 1st curves (i.e., the Tl Team, a hazard analyst, etc.) and the hazard Line code that was used. 1001. Section 0.2. Page 0-Please describe in more detail the modification that was made to the 2. 3rd Paragraph, 5th ASK14 model. Line 1002. Section 0.2, page 0-Similar to the earlier comment, a comma after the words "hanging-2, 2"" paragraph of wall model .. would help insure a correct interpretation of the section, line 6 sentence. 1003. Section 0.2. page 0-Please consider adding the qualifier that the mean hazard from the 2. 3rd of common-form models plots near the up per limit of the GMPE range section. 3' sentence at the relevant hazard levels (e.g., to* and less) and that this does not seem to be so clearly the case at higher hazard levels. t004. Figure 0.2-1a, Page In this and all similar figures in this appendix. please use the same 0-3 acronyms for the models listed in the legend that are used elsewhere throughout the report and appendices (e.g., use "ASK14" instead of "ASK") 1005. Section 0.3. General Except for showing hazard curves from Model A and Model B together on the same plot, Section 0.3 appears to provide the same information as provided in Section 9.1.1.3 (and Figures 9.1-19 and 9. t-20). Please clarify what is new in Section 0.3. compared to Section 9.1.1.3. t006. Section 0.3, Page 0-Please see comments given in other chapters and appendices 7. 2nd Paragraph regarding suggested revisions to the bullet list of references to these six GMPEs. 1007. Section 0.3. Page 0-Please avoid the use of the subjective term "significant" and instead 7. 3rd Paragraph. 9th provide a quantitative metric to describe the contribution to the Line hazard of the distant seismic sources. t008. Section 0.3, page 0-Please add a comma after the word "strong." to signal that the 8, last line subsequent "as" is being used as a conjunction to introduce a clause (not to express similarity). t009. Figure 0.2-1a, Page It is difficult to tell the difference between the two blue dashed 0-9 curves in this plot. Please use a different color and/or symbol so that these two curves can be more easily distinguished in this and similar figures in this appendix. t010. Section 0.4, Page 0-Please ensure that all of the references cited in the text are included 13 in the list of references and that all of the references provide a complete description of the publication (e.g., volume and page numbers). APPENDIX Q Host Kappa 1011. General comment A list of references is missing from the appendix. Please include a complete list of references in a separate section of the appendix. 1012. General comment There are a lot of parameters. terms, and acronyms used throughout the appendix without first being defined. As a reiteration of previous comments on various chapters and appendices in this report. please ensure that all of the parameters. terms. and acronyms used in this appendix are defined in a list prior to their use. Otherwise, they will need to be defined the first time they are used in each chapter and appendix. 1013. General comment Please check, in this appendix and throughout the report, to ensure that geographical terminology and acronyms are consistent with usage in the DCPP and PVNGS SSC projects. One example worth checking is whether "Sonoran Basin and Range" is the name for the PVNGS host region (please confirm that it is not southern Basin and Range" in the PVNGS SSC, or if it is, make changes to ensure consistency). 1014. General comment Please make the notation consistent throughout the chapter (and consistent with the rest of the report). For example, the decay exponent is sometimes spelled out in roman letters as "kappa". sometimes given by the Greek letter K, and k1 and k1 seem to be used interchangeably (and k(O) is used in lieu of Ko, even though the latter seems to be advocated by Ktenidou et al.. 2014 ). In the process of clarifying, please also give consideration to the merits of following as strictly as possible the published taxonomy of Ktenidou et al. (2014). 1015. General comment Please define kappa and provide the foundational references that established the empirical basis for this concept. 1016. Page Q-1 , first The term "Host kappa" is jargon that only insiders will understand. paragraph particularly since "host" is used in multiple, seemingly quite different senses in the report (e.g., in Chapter 14, "host" refers to the Sonora Basin and Range region in which PVNGS is situated}. Please begin by explaining precisely what is meant by the term in the current chapter and how the host kappa estimates are then used in the GMC model. Please also cross-reference those places in the report where the resulting kappa estimates are used 1017. Section Q.1. Page Q-Please revise the Akka r et a I., Bindi et al., and Zhao references to 1. 1st Paragraph of show the correct publication dates and acronyms (as used Section elsewhere throughout the report and appendices) and to include the published errata for the first two references. Please also ensure that the correct acronyms for the GMPEs that are used throughout the report and appendices are used here and elsewhere throughout the appendix. including in figure legends and figure captions. 1018. Section Q.1. page Q-Please provide the meaning of IRVT upon its first occurrence, and 1, paragraph of provide a reference to the method (not just to the computer section, 1" sentence program). 1019. Section Q.1. page Q-Please rewrite the sentence with parallel construction to improve 1, 3"' paragraph of clarity (e.g., "for spectra with higher host kappa than for those with section, last sentence lower host kappa." if that is the intended meaning). 1020. Section Q.2, Page Q-Please provide a reference for the IRVT approach that is used. (e.g .. 1, 1st Paragraph of if it is that published by Al Atik et al., 2013, please indicate that). Section, 1st Line 1021. Section Q.2, page Q-This comment refers to the phrase "while also limiting the Q 1, 1" paragraph of attenuation effects" The kappa effect is itself most likely. at least in section. Line 4 part, a Q effect (which would be better described as an "anelastic effect"), but just one that is so localized that it is more practical to treat it as a separate site-associated parameter. To avoid feeding confusion on this point. please state more precisely what is meant by this phrase. If the Tl Team chose close stations in order to isolate that part of the attenuation that persists in the limit of short propagation paths and is therefore suited to modeling as a site-associated attenuation factor exp(-pi"kappa*n. please indicate that 1022. Section Q.2, Page Q-Because of its common use in stochastic simulation. please also 2, 2nd Paragraph on provide and plot the Vs profile for the WUS crustal model of Boore page. 1st Sentence and Joyner ( 1997) in Figure Q-1 . Likewise, please plot the related site-amplification factors for the WUS crustal model of Boore and Joyner (1997} in Figure (Q-2). 1023. Section Q.2. Page Q-Please describe and reference the "OWL program" that was used to 2. 2nd Paragraph. 6th obtain the Vs-density relationships and summarize those Line relationships for completeness. 1024. Section Q.2. Page Q-Please explain what an angle of incidence of zero means and why it 2. 2nd Paragraph, 5th was assumed to be zero and what impact this assumption has on the Sen1ence final results 1025. Sec1ion Q.2, page Q-Please consider referring to "the nine selected scenarios" 1o clarify 3, 3"' paragraph of that the reference is to the selections made in the earlier paragraph section ( 1*1 on page). for 1he reasons stated there. The current language given by the 1 *1 sentence phrase the nine scenarios considered," could be misunders1ood as part of an evaluation process (i.e., that some were considered and rejected, for example). 1026. Section Q.2. page Q-This sentence asserts that the kappa derived using the IRVT 3. 3rd of approach (kt} is not equal 1o kappa(O). This categorical statement section (16 on page). could imply that k 1 is in principle not able to capture kappa(O). Is that line 8 &9 really the meaning intended? If so, please explain, and reconcile this asser1ion with 1he fact that Ktenidou et al (2014) classify the IRVT-derived method as a k(O) estimator in their Table 1. Otherwise. please reword these lines. 1027. Section Q.2. page Q-As noted in an earlier comment, the reference here to "anelastic 3, 3"' paragraph of attenuation" implies that the kappa decay factor is not a section (1"' on page), consequence of anelastic attenuation. whereas the scientific 2"' to last sentence consensus is that it is (at least in part). Please reword this sentence to express the intended meaning more precisely. 1028. Section Q.2. page Q-Please explain the distinction being made here between k(O) and 3. 3rd paragraph (1*1 k,;,., and justify the assumption that there is no source contribution to on page), last line kappa. 1029. Section Q.2, page Q-Please explain what is mean1 by "bes1 picks." On what criteria was 3. 41to paragraph of the selection made? section (2"" on page). Line 5 1030. Section Q.2. Page Q-Because this appendix is intended to present the details of the host 3. 2nd Paragraph on kappa calculations. please provide plots for all nine scenarios for all page. 5th Sentence seven GMPEs for completeness. 1031. Section Q.2, Page Q-For completeness. please provide the standard deviations of the 3, 2nd Paragraph, 6th host kappa values shown in Table Q-1 that account for uncertainly in Sentence the f1 and f2 picks, the nine different scenarios, and the two different crustal models 1032. Section Q.2, page Q-The phrase "best es1imate seems to be used in two different senses 3, 4'" paragraph of in its two occurrences in this sentence. Please clarify. Also note that section (2"c on page). there appears to be a missing word or words after "GMPE." last sentence From: Steven Day <sday@mail.sdsu.edu>

Subject:

informal comments Date: February 9, 2015 at 4:43:37 PM PST To: Norm Abrahamson <abrahamson@berkeley.edu>, Carola DiAlessandro <carola dialessandro@geopentech.com> Cc: Steven Day <sday@mail.sdsu.edu>, Thomas Rockwell <trockwell@mail.sdsu.edu>, Brian Chiou <brian chiou@comcast.net>, Kenneth Campbell <ken.w.campbell@comcast.net> Attachments: SWUSFinal Rpt CommentsTKR.docx (48 KB); SWUS Final Rpt suggested -1.docx (56 KB); SWUS_Comments_Rev1_smd.docx (71 KB) Carola and Norm, Thanks for a productive meeting this morning. And thanks, Carola, for agreeing to assist us by setting up the PPRP conference call next week. That is a big help. As promised, here are some unedited preliminary comments from Tom and myself. These are not to be understood as formal comments from the PPRP, as they have not been discussed, reconciled, edited or approved by the full panel. However, we are happy to provide them informally, acting as individuals, for your consideration. Tom's comments are complete for the main sections (and he provides a second file with what are more purely editorial comments). Mine are complete for Chapters 3-15, and I also include several of the appendices. Steve February 20, 2015 Dr. Carola Di J\ lessandro SWUS Project Manager GeoPentech, Inc. 525 N. Cabrillo Park Drive, Suite 280 Santa Ana, CA 9270 I

Subject:

Participatory Peer Review Panel Letter No. 3: Draft Rev. I Report, Southwest United States Ground Motion Characterization Level 3 SSHAC Project

Dear Dr. Di Alessandro:

This letter provides comments and recommendations of the Participatory Peer Review Panel (PPRP) for the SWUS Project Report, Draft Rev. I. Here we address Chapters 1 through 16. Our Letter No. I (dated December 13, 2014) already provided comments on Chapters 7, I 0, 11, 12, and 13, and Appendices L, M, N, and R of Rev.O. Our Letter No. 2 addressed Chapters 6, 8, 9, and 14, and Appendices H, I, J, K, 0, and Q of Rev.0. We have not yet had the opportunity to thoroughly review all of the revisions made to the appendices for Draft Rev. I. The review comments are tabulated in two parts. Tier I comments are those that the PPRP considers of the highest relevance to our assessment of the documentation. Those are listed separately at the beginning of the Comment Table, identified by both chapter and line number. Tier 2 comments are additional comments tabulated by chapter and identified by line number (or table or figure number where more appropriate). Each comment in the review is assigned a unique number for reference. Comments transmitted previously with Letter No. I were numbered 1-320, those with letter No. 2 were numbered 321-1032, and the numbering of comments transmitted with the current letter start with l 033. The table includes an additional column in which the responses of the TI Team may be recorded. The review is not intended to be editorial. but we do call attention to stylistic or grammatical concerns in instances where they substantially affect clarity or may introduce ambiguities. The Draft Rev. I report covers the full scope of the evaluation and integration efforts of the Tl Team. These review comments from the PPRP are intended to help the TI Team improve the quality and clarity of its documentation of the technical basis and justifications for the models and weights used in the final GMC logic trees. Sincerely. Steven M. Day Chair, PPRP Brian Chiou Member, PPRP Kenneth W. Campbell Member, PPRP -1 :'.. 1 i. .1 .* s".> -// /-* .. *'" Thomas K. Rockwell Member, PPRP Comment Response Table Comment Location in Text PPRP Comment Summary of Revisions to Report Number Tier 1 Comments 1033. Directivity model: The Tl team has not provided sufficient information detailing their General evaluation of the directivity model. It is necessary that the explanation of the Tl Team's evaluation include sufficient detail to clarify (1) what the model is. (2) what its limitations are, and (3) what analysis was done to demonstrate that it is justifiable (in light of any model limitations) to use it for the purpose it is being used for here. Please provide an explanation meetina those criteria in the reoort. 1034. Directivity model: There are two major assumptions that are made in applying the CY14 Chapter 6, Lines 914-centered directivity model to the GMPEs used in the DCPP GMC model: 922 (1) that the large-magnitude distribution is similar amongst the NGA-West2 GMPEs so that similar directivity effects can be expected. and (2) that the centered CY14 model can be applied to the NGA-West2 GMPEs to model these effects. These are both potentially important assumptions. Please provide justification for these assumptions or indicate that the imoact of these assumotions is not critical to the hazard. 1035. Directivity model: Please further justify the zero weight given to the directivity adjustment Chapter 9, Lines branch by providing evaluations in support of the claim that directivity 317-320 effects are adequately captured by the standard deviation from the GMPEs Also. if this claim is justifiable. please explain why the same justification was not applied to DCPP to assign a zero weight to its directivitv branch. 1036. Evaluation of Please revise this passage to emphasize that these simplified hazard Common-form suite: comparisons are not the primary basis for evaluating the common-form Chapter 8, Lines 305-suite of representative models (which, though it should be hazard 308 informed, should not be hazard calibrated, i.e., it is required to cover the CBR of the TOI of ground motion, not hazard). II appears that the simplified hazard comparisons are actually being used as a final check to ensure that occasional small excursions of the candidate GMPE estimates (with added epistemic uncertainty} do no carry unexpectedly high leverage with respect to hazard. If that is the case, please reframe the discussion to clarify that. The additional discussion should emphasize this point by summarizing the non-hazard-based justification for accepting a suite of common-form models that does not fully envelop the predictions of the candidate GMPEs (all of which were considered to be credible--i e .. they passed the test by the Tl Team of being technically defensible interoretation s ). 1037. Evaluation of Although it is reasonable to use the hazard as a guide in determining Common-form suite: whether the representative models produce a wide enough hazard Chapter 9, Lines 301-distribution, it seems appropriate that the distribution of the ground 313 motion models should also be wide enough to encompass the candidate models and their epistemic uncertainty. Please explain that both of these distributions were checked and that the hazard distribution alone is not being used to judge whether the representative suite of models represents the CBR (especially the range) of the ground motion distribution, which should be the intent of a SSHAC Level 3 ground motion studv. 1038. Short-range Please reconcile the statement that the finite-fault simulations all show saturation: Chapter 6, saturation at short distances" with the statement on Line 697 of Lines 40-41 Appendix J (and evidence in Figure J.4.3-1) that "the GMPEs have stronger saturation than the EXSIM model at very close distances." If it is correct that EXSIM has less saturation at short distances. please explain why this should not be interpreted as support for the ld14 model (e.g., is the formulation of EXSIM such that it is not intended by its developers for use at the shortest distances? Or does the Tl Team argue on physical arounds that EXSIM is not reliable at short distances?). 1039. Short-range The 1014 model was deemed unreliable by the Tl Team in the range of saturation: Chapter 6, M <: 7.5 and R::; 3km The description of the Tl Team's justification is Lines 47-61 and based mainly on the interpretation that 1Dt4's predicted median PGA is Figure 6.2.1-2 an outlier (it is higher by about 40% than the predictions of other candidate GMPEs). However, the predicted median at Rs; 3km for T = 2s from the ZL 11 and the ZH06 GMPEs are also much higher than the other GMPEs (by more than 50%), but neither were rejected (Figure 6.2. t-2) Please iustifv the seeminalv inconsistent assessments. 1040. Consistency of Key The parameters FREv and F.,.L defined on these lines do not appear in Equations: Chapter 6, Eq (6.4-1 ). On the other hand.Fin Eq 6.4-1 is not defined. Furthermore. Lines409.4t0 this equation differs from what would seem to be intended to be its equivalent in Appendix C, Part II, Line 33. where FRFv and F*M1 appear. but not F, and an additional coefficient a1o appears that is absent in 6.4-1. Also, coefficient ag is squared in 6.4-1, but not in the Appendix C counterpart. It would be beneficial and less confusing to many readers if the same terminology for predictor variables used in the NGA-West1 and NGA-West2 projects were used throughout the report. For example, please consider replacing "FF<Ev" and FN"L" with "Ff<*/ and F""" (and note, as mentioned above. that these terms are not actually used in Eqs (6.4-t) and (6.4-2) and instead only a single T' indicator variable is used in these equations). Please replace "F" in these equations with the mechanism-specific predictor variables or modify the text accordingly, and in any case make changes to ensure consistency with Appendix C. It is likely that the inclusion of a tenth coefficient in the text that follows refers to the inclusion of two predictor variables to represent the style-of-faulting. If this is the case. and the equations are corrected. then please ignore those comments that refer to the missing tenth coefficient elsewhere in the list of comments. Tier 2 Comments (by chapter) General 1041. NIA Please carefully review the references for completeness and to ensure that all cited references are listed. For example, some of the same references in different chapters are listed slightly differently (i.e .. one might be missing a volume number or page numbers while another miaht notl. t042. NIA The report is written primarily in third person. which implies that the writers of the report, chapter, and/or section performed the work or made the decisions and assumptions that are being described. However, there are no specific authors listed on the report, which is only identified by the publisher. GeoPentech. and a list of participants in the project. Please make it clear who the writers of the report are either on the Title Page (ideally) or in the introduction so that there is clear ownership of the work that is beina described in the third oerson. When the descriotion refers to someone else's work. decision. or assumptions, please make it clear that this is the case. There are also still sporadic uses of the pronouns "we" and "us" throughout the report, which is even more ambiguous. Please consider replacing these pronouns with the person or group that the pronoun refers to (e.g., the Tl Team or a specific Resource Expert) or change the sentence to third person to refer to the identified writers of the reoort. CHAPTER 0-Table of Contents 1043. NIA The Section No. 5 21.1 appears twice. The second one should be 5.2.2.1. 1044. NIA In the title of Section No. 5 5 3. Vs should be 1045. NIA The Section No. 6 4 5 3 appears twice. The first occurrence should be 6.4.5.2. CHAPTER 1-Introduction 1046. Lines 57-58 The description of Vs*o as shear-wave velocity" should be more accurately described as "travel-time-averaged shear-wave velocity. This change also applies to the definition of in the list of terms and acronvms. 1047. Line 63 Please define "kappa." since this is the first time that this term is used in the report. Please also add the definition of kappa to the list of terms and acronyms. which only contains the specific symbols used to characterize the different ways kappa can be estimated and no definition of the generic term kappa itself. 1048. Line 80 Please define sigma," since this is the first time that this term is used in the report. Please also add the definition of sigma to the list of terms and acronyms. which only contains the specific symbols used to characterize the different types of standard deviations and no definition of the generic term siqma itself 1049. Line 109 Please consider replacing the phrase "suites of models" with "representative suite of models here and elsewhere in the report to conform with terminology used in "Atkinson, G.M., Bommer, J.J., and Abrahamson, N.A. (2014). Alternative approaches to modeling epistemic uncertainty in ground motions in probabilistic seismic-hazard analysis, Seismo/oqical Research Letters, Vol. 86. pp 1141-1144." CHAPTER 2-Project Organization 1050. Line 52 The description of the workshops is incomplete and does not list all of the purposes of the workshops. Please qualify the sentence to indicate that this is only one of the purposes of the workshops or expand it to list all of the purposes. 1051. Line 53 Since this is the first time that peer review is mentioned in the report, please introduce the peer review panel and the acronym PPRP. Please also add the definition of PPRP to the list of terms and acronvms 1052. Line 75 The use of the phrase "Appendix A of Appendix A" is awkward. Please consider calling the appendix of an appendix something different in order to avoid confusion Ce.a., "annex"). 1053. Line 81 Please correct the name of the power plant. i.e., "Saint Onofre" should be "San Onofre." 1054. Line 146 Please correct the grammar in this passage, e.g .. "preliminary estimate of the kappa sensitivity ... " 1055. Line 157 The large magnitude earthquakes in California cited here appear to be the same events referred to elsewhere in the report as large earthquakes in California and Mexico (appropriately, since the 2010 El Mayor-Cucapah event is included). Please clarify or correct for con sistencv. 1056. Line 162 Please provide a reference to the PEER report that is mentioned in this sentence. 1057. Lines 167-171 Please provide references for the PEER projects that are referred to in this paragraph. 1058. Line 187 Please reference the report or appendix where the PE&A study can be found. 1059. Line 189 Please consider replacing the word "sensibly" with one that better conveys what the writer intended to mean. 1060. Line 253 Please explain what "anticipated" means in this context. CHAPTER 3-SWUS GMC Work Plan and Key Study Tasks 1061. Line 97 Please confirm that the distance range 30-100 km is correct and should not be "less than 100 km." 1062. Line 152 In Table 3.4-1, "Ken Campbell Consulting" should be "Kenneth W Campbell Consulting." 1063. Line 244 Please clarify that "the second meeting" refers to the January 2014 Special Working Meeting. 1064. Line 340 In Table 3.7-1, "Ken Campbell Consulting" should be "Kenneth W Campbell Consulting." CHAPTER 4-Seismotectonic Setting 1065. Line 160 Please explain the difference between .. layered faults" and "individual faults. 1066. Lines 163-164 These lines refer to two categories. namely .. the California and Mexico faults (referred to as Regions 1 and 2&3 in this Report)," and "other faults (AZ,NM, NV, and Mexico):* Table 4.2-2 has rows for CA Faults" and "AZ, NV, & Mex Faults. Do the rows of the table correspond to the two categories of faults described in the text? If so. please align the terminoloov; if not. olease clarifv. 1067. Lines 172-179 The legends of Figures 4-8a and 4-8b are not well correlated with the text. For example. "NSHMP faults" are noted in the legends but are defined neither there nor in the text. And the text calls attention to the dominance of distant fault sources for low frequency at 10-* AFE, but the figures do not identify the curves associated with distant fault sources. Please reconcile the figure legends and the text. 1068. Line 289 In Figure 4-8a, please explain the meaning of "coarse" and fine" areal sources. 1069. Line 293 In Figure 4-8b, please explain the meaning of "coarse" and "fine" areal sources. 1070. Tables4.1-4, 4.2-1. Please identify the pertinent site (i.e., DCPP or PVNGS) in the title of 4.2-2 each of these tables. 1071. Figure 4-1 The two line colors for the SAF are not well distinguished in the figure. Please consider making improvements to remedy this. 1072. Figure 4-2 Please identify the site (DCPP) in the figure caption. 1073. Figure 4-6 The arrow for the Cerro Prieto fault points to the Imperial fault (CPF is the next bold red line to the SW). Please correct this. CHAPTER Motion Databases and Candidate Models 1074. General Two references for Kishida et al., 2014a and 2014b, appear in the reference list. However, many of the citations in this chapter refer only to Kishida et al. (2014) without distinguishing 2014a from 2014b. Please check and correct this omission. 1075. General The figure numbering scheme seems to be inconsistent in this chapter. For example. Figure 5.2.2-2 is called in Section 5.2.2.1. indicating the convention that only the chapter number and first two section levels prefix the sequence number. But a Figure 5.2.3.4-1 is called in Section 5.2.3.4, so in that case the chapter number and all three section levels prefix the sequence number. There are some other anomalies as well. Please check carefully and ensure that numbering is done consistently th rouahout. 1076. Line 11 Use of the term "proponent models" is confusing. especially given that the report is written in third person with no identified authors. The term is usually reserved for describing a model or method proposed by a Proponent Expert (PE). If this is not the meaning of the term in this context or in similar contexts elsewhere in the report, please consider using another term to describe the models or identify who the proponents are (e.g .. 'Tl Team proponent models") when the term is used. 1077. Line 27 The intended meaning of the sentence is ambiguous. If the in1ent is to say that the Wells earthquake was in the southern Basin and Range. please review for accuracy (e.g., was it in the northern or southern Basin and Range?). If the intent is that the Wells earthquake provides control for a normal faulting earthquake, if one should occur in the Southern Basin and Ranae, olease clarifv and correct, as needed 1078. Line 31 Since this is the first time that the term "PSA is used in the report, please define it. 1079. Line 47 Please add that the bottom frames also show the number of recordings per site class. 1080. Line 85 There is no evidence in Figure 5.1.2-1 of "Station Z14A, shown by the open star". Please clarify. 1081. Line 87 Please complete the citation of Kishida" (i.e., Kishida et al. 2014a or 2014b?). 1082. Line 158 Please correct the figure number on this line, which should be Figure 5.1.5-1. 1083. Lines 173-174 The spelling of the fault names differs between the text and Figure 5.1.5-2 ("ltozawa" in the figure becomes "ldozawa" in the text. and "Yunodake" in the figure becomes .. Yunotake** in the 1ext). Please edit for con sistencv. 1084. Lines 175-176 The 1otal moment given here and attributed 1o personal communication is inconsistent with the moment magnitude of 6. 7 given for this event on Line 164 (the sum of the moments on Line 175 imply M 6.56). Please resolve the inconsistency. In doing so, please consider whether it would be appropriate to cite published moment estimates (e.g., Tanaka et al.. 2014, report a moment consistent with M 6.7 and approximately equally parti1ioned between the two faul1s} instead of those reported from oersonal communication. 1085. Line 202 Please supply the missing Table 5.1. 7-1. 1086. Line 209 The symbols referring to the different types of kappa used in this sentence are slightly different from those listed in the terms and acronyms. Please use a consistent set of symbols for kappa throughout the reoort and aaoendices. 1087. Line 216 K0 is undefined at this point in the text. Please correct this. 1088. Line 223 Please consider whether a more appropriate characterization than "upper bound" can be used here (e.g .. is that categorical statement even consistent with the one standard deviation ranges cited forthe other methods?). 1089. Line 228 Please include a reference to a publication describing the SCEC BBP (e.g., the paper by Maechling et al. in the Jan/Feb 2015 SRL may be aoorooriate ). 1090. Line 242 Please consider citing the published paper by Dreger et al. (2015) in the Jan/Feb 2015 SRL. 1091. Lines 264-266 It is appropriate for the Tl Team to rely on the SCEC Validation Review Panel for the technical analysis of the simulations, and to rely upon the judgment of that panel to determine which methods met the acceptance criteria established in that review. However. the Tl Team itself needs to justify that meeting those acceptance criteria makes the methods suitable for the specific purposes for which the simulations are to be employed. Those purposes are stated on Lines 227-233. Please augment the summary statement on Lines 264-266 by explaining how meeting the SCEC review panel's acceptance criteria makes the simulation methods suitable for addressing the problems laid out on Lines 8-14. 1092. Lines 306-315 This passage needs rewriting because: (1) the BSL model is not identified as GIL7 on Line 309, but seems to be the same as what is called GIL7 in the legend of Figure 5.2.2-1 and then on Line 312; and (2) the passage is repetitive (e.g., the verbiage about routine estimation of moment tensors on Line 309 is repeated on Line 314-315; the basis of the GIL7 model in broadband waveform modeling is stated repetitively on Line 308 and then on Line 3141. 1093. Line 322 "Frequency wave-number is written differently on this line than it was on Lines 304 and 311 ("frequency-wave number"). Please review the hyphenation convention and apply one consistently (note also that both "wave number" and "wavenumber" are in common use, so the easier-to-read form "freauencv-wavenumbe(' is also an ootion). 1094. Line 361, 364 "Area" is used to signify rupture area in Equation 5.2.3-1. but "A is defined as rupture area on Line 364. Please edit for consistency. 1095. Lines 374-375 Please indicate whether this statement is an assumption or is based on an evaluation of data, models, etc., by the Tl Team. 1096. Line 383 Please correct the figure number. It is called out as Figure 5.3.2.1-1 on this line, but the figure itself is labeled as Figure 5.2.3.1-1. Moreover, the numbering scheme used elsewhere in the report appears to call it Figure 5.2.3-1. since it occurs in a subsection of Section 5.2.3 (e.g .. by analogy with the fact that Fiqures 5 2 2-1 and 5 2 2-2 occur in Section 5.2.2.1) 1097. Line 392 The figure number 5.2.3.2-1 is inconsistent with the fact that it is the second figure in the subsection. Please check the figure numbering convention and make it consistent with the rest of the chapter and report. 1098. Line 396 Please indicate that CB14 also used the functional form of the hanging-wall term developed by Donahue and Abrahamson (2014). 1099. Line411 Please consider replacing "we" (first person) with third-person to be consistent with the remainder of the report. 1100. Lines 427, 431. and The figure citations do not correspond to the figure numbering. Please 433 check the figure numbering against the figure citations and correct as needed. 1101. Line 452. 458 The table called Table 5.1.1-2 on this line appears to be the table labeled Table 5.1-2 (and called by those numbers elsewhere in the report). Please correct here and in subse<1uent occurrences. 1102. Line 464. 475. 481 Line 464 gives the distance criterion for NGA-W2_DC-MED as abs(Rx)<70km. whereas the lines 475 and 481 give it as R<70 km, which is more restrictive. Please clarify how the various distance metrics are used toaether to screen records for NGA-W2 DC-MED. 1103. Line 492 Please quantify what .. similar enough" means in regards to the value of Vs30 (e.g., in terms of the percent difference in site-amplification factors). 1104. Line 506 Previously, Akkar et al. (2014c) was cited as the database reference. Please check whether the citation given on this line is correct in the oresent context. 1105. Lines 508 and 517 The criterion abs(Rx)<70 km leaves the total distance unconstrained. Please provide a complete statement of the distance selection criterion. 1106. Line 548 Please consider whether this might be a good place to introduce the symbol ell,., so that ii will be defined prior to its use on Line 553. 1107. Line 558 "Disaggregation .. is used on this line, whereas "deaggregation" is used elsewhere in the report. Please edit for consistency. 1108. Lines 565-572 The selection criteria (distance, magnitude, number of recordings per event and site) do not seem to be given. Please check and correct if necessary. 1109. Line 566 "NGA-W2" is "NGA-West2 .. elsewhere. Please edit for consistency. 1110. Line 579 Please check whether for use in" should be "is used in". As is, the sentence lacks a verb. 1111. Line 585 Please add the missing parenthesis closure. 1112. Lines 592-593 Please indicate whether the 3 events per station requirement was also applied. 1113. Line 601 Section 5.4.1 does not contain the discussion of the Idriss 2014 model that is referenced here ("As noted in Section 5.4. r). nor does there appear to be any prior reference to the Idriss model in the chapter. Please make the necessarv corrections. 1114. Line610 Please replace "200-30 km" with "30-200 km." 1115. Lines 614-615 CB14 used mixed-effects regression to derive the anelastic attenuation term from data with RKuP > 80 km, but allowed the source terms to vary from those for RRuP < 80 km. Although this does not necessarily impact the decision not to use CB14, the description of what CB 14 did should be correctly stated in the text. 1116. Line 619 Please indicate what range that "this magnitude-distance range" refers to. 1117. Lines 619 and 626 Line 619 has the statement that "the global dataset in this magnitude and distance range consists of 264-415 record in gs from 4 to 2 3 earthquakes." Line 625 states "Within this magnitude and distance range, the global dataset contains four earthquakes and 280 records." Please clarify whv these statements are not contradictory. 1118. Line 627 The cited figures do not exist. Please add them. 1119. Line 669-670 Please correct the figure references (they should be to Figures 5. 5 .1-1 and 5.5.1-2). 1120. Line 673 Please correct the figure reference (it should be to Figure 5.5.1-3). 1121. Line 683 Please correct the table reference (the intended reference appears to be to Table 5.5.1-1 ). 1122. Line 724 Please clarify why specific scenarios had to be specified, given that kappa is not being explicitly modeled as a source effect. 1123. Line 725 Please explain why only footwall scenarios were used. 1124. Line 727 Please consider rewording the reference to "Q attenuation," to avoid the implication that the kappa effect is necessarily physically distinct from effects ordinarily parameterized in terms of Q. Isn't the point that the kappa parameter (or at least K.,1) is intended to capture attenuation effects that are so localized that in a practical sense they are better parameterized as site terms than as path-dependent attenuation terms. and that therefore isolation of kappa effects requires short-distance scenarios? 1125. Line 730 Please be more specific about which profile was used. Is it one of those in Figure 2.6 of Kamai et al. (one is listed as having Vs30 of 750 mis. none has exactlv 760 m/s)? 1126. Line 735 Figure 5.5.3-1 appears to be labeled incorrectly. Please correct this. 1127. Line 778 Rodriguez-Marek (2013) actually developed four single-station sigma models: one with neither M nor R dependence, one each with Mand R dependencies, respectively, and a fourth with both Mand R dependence. Please clarify which three have been chosen, and why. Note also that there is a perception of ambiguity introduced by mixing .. dependent" and .. independent" in listing the attributes of the selected models: i.e .. is the .. magnitude-independent" model alluded to also R independent (in which case it would be clearer to say "magnitude and distance independent), or is there a typo such that "magnitude-dependent" is what is actually intended? If one of the figures were not missing, this ambiguity would be cleared up, but it would be better to also do so in the text. 1128. Lines 779 and 781 Please check whether the first of the three models alluded to should be .. magnitude-dependent" (rather than .. magnitude-independent". which would appear to be inconsistent with the figures). Alternatively, if "magnitude-independenr is correct as written, please clarify whether it is paired with a distance dependence or not. 1129. Lines 780-782 Only the R-dependent and MR-dependent models are shown, and these are in Figures 5.6.2-3 and 5.6.2-4, respectively (not 5.6.2-4 and 5.6.2-5 as called in the text). The other model (called "magnitude-independent" in the text) is not shown. nor is there any Figure 5.6-5. Please correct this. 1130. Line 789 Please cite a reference for the assertions about the small-magnitude limitations of GMPEs at short distance. 1131. Line1122 Table 5.5.1-1 indicates that the Graizer (2014} GMPE was used for the DCPP GMC model. but the Graizer GMPE is not listed as being one of the models that was used in Chapter 6 Please either correct the table or the text in Chapter 6. If this GMPE was used, please justify its use in nf tho it nnl\I nl not been peer reviewed or vetted by the larger scientific community. 1132. Figure 5.1.3-1 The caption cites Akkar et al. (2014a and 2014b), whereas the text (Line 121) cites Akkar et al. (2014c), apparently in the same context. Please check whether this difference is intentional and make a correction if aoarooriate. 1133. Figures 52.3.4-1 and These figures are mislabeled (as 5.2.3.3-1 and 5.2.3.3-2, respectively). 5.2.3.4-2 Please correct. 1134. Figures 5 3.2-1 and Please correct these figures. In each of these figures, the second row 5.3.2-2 repeats the first with a scale change. and the remaining plots (recordings oer site, recordinas per event, etc.) are absent. 1135. Line 1258 In Figure 5.4.1-2, please explain why there is a triangular symbol plotted at slightly over 100 km or, if this is an error. please remove the symbol. 1136. Line 1263 In Figure 5.4.1-3, please explain why there is a triangular symbol plotted at slightly over 100 km or, if this is an error, please remove the symbol. 1137. Line 1322 In Figure 5.5.1-1, please define the meaning of the solid black symbols and the color and black trend lines. 1138. Line 1326 In Figure 5.5.1-2, please define the meaning of the solid black symbols and the color and black trend lines. 1139. Figure 5.5.3-1 Please correct the figure number. It is called Figure 5.5.3-1, but labeled 5.5.3-2. 1140. Figure 5.6.2-2 Please improve the figure caption by including some basic contextual information. 1141. Figure 5.6.4-1 Please add the dataset identifiers given in Lines 805-808 of the text (Blea, Blea2, and ABR) to the figure caption, or else delete them from the text, as the inconsistency is confusing. CHAPTER 6-GMC Models for the Median 1142. Lines 23-24 Table 5.5.1-1 indicates that the Graizer (2014) GMPE was used for the DCPP GMC model. resulting in the use of 9 models. The text indicates that 8 models, excluding the Graizer GMPE, were used. Please correct either the table or the text. 1143. Line 105 Please hyphenate "large-distance attenuation" to resolve the otherwise ambiguous meaning. 1144. Lines 209-210 Not all of the simulations show that hanging-wall effects persist down to magnitudes of 5.5 and 6.0 for all fault geometries. This suggests that there is some uncertainty in whether such effects exist. Please discuss this apparent uncertainty and justify the decision to extend hanging-wall effects to smaller magnitudes. explaining whether this uncertainty is accounted for elsewhere. 1145. Lines 256-257 Please explain why. if hanging-wall effects are geometric. the cosine term is more appropriate than the arithmetic angle to model these effects. 1146. Line 269 The statement that the hanging-wall models are "equally likely" and "normally distributed" is still confusing on its face. However, the discussion that follows clarifies this apparent contradiction vis-a-vis the use of equal probability slices of the distribution Perhaps. a statement like "as explained below" after introducing this apparent contradiction would provide less confusion for the reader. 1147. Line 303 Figure 6.3.2-5 shows CB14 having a step-like change in its HW factor as Rjb approaches zero along the strike direction. Please clarify how this is consistent with the claim that CB14 allows "a smoother transition" around the rupture compared with some other models. 1148. Lines 341-343 In reviewing all of the figures comparing the HW adjustment model with the simulations, all except Figure 6.3.2-14 compare the simulations only with the central HW model In order to show that the five HW models adequately capture the uncertainty in the simulations. please show all five HW models in all of the figures and discuss any cases in which the five models to not aooear to caoture the uncertaintv. 1149. Line 363 The term "scaled-backbone approach" is never used by Atkinson et al. (2014). These authors do mention the concept of selecting a single "central or backbone GMPE" and scaling it up and down, but do not specifically call this a scaled-backbone approach. Please consider replacing the term "scaled-backbone approach" with a simple description of the aaoroach instead. 1150. Line 384 The term "generated models" is used in this sentence to refer to ground motion models derived from the visualization (Sammon's mapping) technique. Terms such as "large suite of models" and "representative models" were used earlier in the section to refer to similar models. The concept of using visualization techniques to produce a distribution of models that sample the full model space is difficult enough to understand without being confused further by the use of different terms to describe the same technique or products thereof. In order to avoid such confusion, please consider using a consistent and strict set of terminology to refer to these models. For example, the term "candidate models" has been generally used to describe the GMPEs that are used in conjunction with the visualization method, since this term is used elsewhere in the report to describe such models: the term "suite of models" might be used to refer to the entire set of models that are generated using the visualization technique (e.g .. the 2000 common-form models); and the term "representative suite of models" might be used to refer to the final set of models that are used in the GMC logic tree (e.g., the 25 or so common-form models). This latter term is also consistent with the general term used by Atkinson et al. (2014) to describe the method of generating models that sample the model space. whether it be by simple methods (i.e., scaling up and down) or by more comolex models, such as those samoled from the Sammon's mao. 1151. Line 402 It is possible that this is the first time that the term "Joyner-Boore distance is used in the report. If so, please note that this term refers to the distance metric R,s. 1152. Lines412-413 Please delete "0,c" and replace "(fork= 7,8,9, 10)" with "(fork= 7,8,9)" since there is no k = 1 O coefficient in the model. 1153. Line 429 Please replace "(fork= 7.8.9, 10)" with "(fork= 7,8,9)" since there is no k = 10 coefficient in the model. 1154. Line 433 Please replace "fork= 7,8,9, 10" with fork= 7,8,9" since there is no k = 10 coefficient in the model. 1155. Line 444 Please replace "fork= 7,8,9 and 10" with "fork= 7,8 and 9 since there is no k = 10 coefficient in the model. 1156. Line 449 Please justify the selection of +/-3 km to represent the uncertainty around the mean value of ZrnR* 1157. Lines 463-464 In order for R,e to equal IRxl. the footwall site must be located at a source-to-site azimuth of -90 degrees (i.e., perpendicular to the fault within the bounds of the ends of the rupture). Please indicate that this is the case in order to iustifv the aiven distance eaualities. 1158. Lines 472 and 493 The term "total residual" is usually reserved to mean the addition of the between-event and within-event residuals in the aleatory variability model Please consider calling this the "total fitted residual" or something like that to distinauish it from the true total residual 1159. Lines 502-513 The entire discussion of using candidate GMPEs and interpolated versions of the GMPEs and the generation and simplification of the coefficient covariance matrices is confusing to a non-statistician. For example, what exactly are the sets of weights applied to and why can the covariance matrices be simplified in the manner discussed? Please consider expanding this discussion to better explain and justify exactly what was done. 1160. Lines 506-513 Please justify how it is mathematically possible with the addition of the interpolated GMPE ground motions to better capture the correlations? 1161. Line 524 Please be precise about what types of "standard deviations" are plotted in Figure 6.4.3-1. 1162. Lines 536-548 This explanation needs to be set out more clearly. The sentence beginning on Line 536 states that "for the DCPP application ... the central HW branch is applied to all common-form models." The rest of the passage. although rather difficult to read. appears to indicate the following: ( 1) HW effects are omitted from the 2000 models used for the Sammon's map, (2) the central HW model is appended to those footwall models, solely for the purpose of the simplified hazard calculations used in the selection of representative common-form (footwall) models from the original 2000. and (3) randomly selected HW models (from the equal-probability set developed in Section 6.3.2) are appended to the selected representative set of footwall models, to give the final set of common-form models for application to DCPP. If this is a correct interpretation, then the last item seems to contradict the sentence from Line 536 (and if this is not a correct interpretation, some clarification is needed). Please rewrite for clarity and consistency. This paragraph would be less confusing if a strict use of terminology to identify all of the different types of models were used. as suggested in an earlier comment. Please be more specific in identifying what set of models are being described in each case. such as candidate models (i.e., the original published GMPES), common-form models (i.e., the mean and interpreted GMPEs and presumably the 2000 or 7500 count versions as well), representative model (i.e., the common-form model that best matches the mean hazard in a given cell), and the suite of representative models (i.e., the ones that are eventually used in the logic tree). 1163. Line 552 Please be explicit as to whether this paragraph is discussing the development of representative models for both sites or just PVNGS. 1164. Line 564 Please replace "magnitude/distance" with "magnitude-distance." 1165. Line 602 Please review the appropriateness of subscript k in NGk. given that there is already a sum over k. 1166. Lines 614-615 Please justify why uncertainty in Ztor is represented by adding 3 km to Ztor and not also subtracting 3 km and why the value of 3 km was chosen to represent this uncertainty (see previous comment). 1167. Lines 616-618 Please explain why a value for Ztor is needed in the R.1A-based models when ii was not used as a term in these models, i.e., how can one Ztor value" be used if the models do not include Ztor at all? 1168. Line 629 Please correct the spelling of the second occurrence of "PVNGs:* 1169. Line 632 Please check whether the intent of this sentence would be more clearly expressed if the final clause were included inside the parentheses. 1170. Line 633 It appears from Eq. 6.4-4 that it is the contributions to the Euclidean distance squared that are weighted by the weights from Eq. 6.4-7 (not the contributions to the Euclidean distance itself. as stated). Please correct or clarifv. 1171. Lines 689-690 The phrase " ... then the point that corresponds to the position of the candidate GMPEs is selected .. is confusing. Please rewrite this phrase to make its meanina clearer. 1172. Line 704 Please correct the typo, ie . "two week" should be "too weak." 1173. Line 706 Please provide a brief statement. or reference. that describes a "Voronoi-diagram" or the section(s) of an appendix where such a reference or definition can be found. 1174. Lines 719-720 Is it true that all of the models within a given Voronoi cell do not really represent the same level of probability on the ground-motion distribution? If this is true, the use of equal weights is an assumption. Please justify the use of equal weights to determine the weighted mean hazard in each cell. 1175. Line 726 Please discuss the common form model that corresponds to the highest hazard curve in Figure 6.4.4-4 and explain why it falls so far above the cluster defined by the rest of the models in the same cell. 1176. Lines 735-736 Although the distribution of HW models is nearly uniform for the DCPP representative models. the distribution of the hazard might not be. depending on what Voronoi cells received the higher HW models (i.e., the high-hazard cells or the low-hazard cells). Please justify that the mean hazard is not biased by the random selection of HW models. 1177. Lines 762-763 Please clarify what results" are not sensitive to the discretization size of the Voronoi cells (i.e., the weights or the hazard). It is possible that the hazard will be sensitive to the size of the cells (e.g., what if only one cell were used?). 1178. Lines 804-807 Please show an example contour plot in Chapter 6 for those readers that do not care to read Appendix H. 1179. Lines 808-809 Please show an example distribution plot in Chapter 6 for those readers that do not care to read Appendix H. 1180. Line 879 Two consecutive figures are called "6.4.5-8." Please check and renumber as needed. 1181. Lines 927-928 The sentence starting with "Randomizing" appears to be unconnected to the rest of the paragraph. Please expand or rewrite this sentence to better convey is meanina. 1182. Line 929 Please see the general comment regarding the documentation of the directivity model evaluation. 1183. Lines 937-939 If the standard deviation represents the variability in the hypocenter location, please explain what the median (or should ii be the mean) represents (e.a., the bias?). 1184. Lines 951-953 Please justify why it is not necessary to include Ztor as a directivity parameter for those events that do not rupture to the surface (e.g., the directivity effects for M5.5-6.5 events that the GMPEs were evaluated for). 1185. Lines 962 -964 Please include sufficient details of the Tl Team's evaluations of the technical merits and limitations of the simplified directivitv model in support of the decision to adopt this model for use in hazard calculations (as also requested in one of the general comments). 1186. Lines 965-967 Please explain the basis for the evaluation that the simplified directivity model is a reasonable approach for capturing directivity effects (e.g., was the hazard using the CY14 directivity model and random hvoocenters comoared to that usina the simplified model?). 1187. Lines 981-982 Please identify which event NGA EQ ID 1017 represents and why it is justified to remove this event because the event-terms of the GMPEs are not consistent. 1188. Lines 990-991 Please explain why there is a difference in plotted values between Figure 6.6.1-2 and Figure 7.4.1-6. 1189. Lines 1008-1009 There seem to be two sets of LN values being given in this section The -0.5 and +0.1 LN units listed in the previous paragraph appear to be biases in the log PSA values, whereas, the 0.32 and 0.35 LN units given in this paragraph appear to be standard deviations. Please make the distinction between these two sets of values clear in the text. Please also be more specific about what "numbers" (the biases or the standard deviations) the Tl Team considers to be "reasonable" 1190. Lines 1015 The use of the term "proponent model" or proponent method is confusing, since it can be interpreted as a model or method being proposed by a Proponent Expert (PE}. If these models and methods are proposed by the Tl Team. please replace "proponent" with "Tl Team" in this line and elsewhere in Section 6.7 where the term is used 1191. Line 1036 Please delete the phrase "with similar rake. dip. width," which is incorrect based on the contradictory and apparently correct description given on Line 1039. 1192. Line 1039 Please note that this statement appears to contradict the phrase on Line 1036, which has been interpreted to be a typo in a previous comment. 1193. Lines 1064-1065 The sentence "The ground motions from the 2011 Fukushima-Hamadori earthquake are evaluated using the SRSS method in Section 9.1.5.2." appears to be disconnected from the sentences before and after it. It is also ambiguous what the "Therefore .. " at the beginning of the next sentence is referring to. Please rewrite these sentences to better convey their intended meanina. 1194. Line 1076 Please explain which complex rupture "Complex Scenario 18" represents. 1195. Line 1096 Please explain which splay rupture "Splay Scenario 1C" represents. 1196. Line 1300 Please confirm whether "Model A" should be included in the title to Table 6.4-2. 1197. Line 1343 Please confirm that the CB14 GMPE is plotted correctly in the lower plot (M6.6, SS, PGA). 1198. Line 1354 Please confirm that the GMPEs are plotted correctly in this plot. For example, CB14 appears to have a hinge or kink at M7, but its magnitude scalina term does not. 1199. Line 1359 Please identify the models listed in the legend to Figure 6.2 3-1 by their correct acronyms (i.e .* ASK14 instead of ASK). 1200. Line 1380 Please identify the models listed in the legend to Figure 6.31-2 by their correct acronyms (i.e .* ASK14 instead of ASK). 1201. Line 1386 Please identify the models listed in the legend to Figure 6.3.2-1 by their correct acronyms (i.e., ASK14 instead of ASK2014). Please also justify in the text why it is acceptable for the predictions from the proposed HW models 1o no1encompass1he predictions from all of the GMPEs. 1202. Line 1391 Please identify the models listed in the legend to Figure 6.3.2-2 by their correct acronyms (i.e., ASK14 instead of ASK2014). Please also justify in the 1ext why it is acceptable for the predictions from the proposed HW models to no1 encomoass the predictions from all of 1he GMPEs. 1203. Line 1396 Please identify the models listed in the legend to Figure 6.3.2-3 by their correc1 acronyms (i.e .. ASK 14 ins1ead of ASK2014 }. Please also justify in the 1ext why it is acceptable for the predictions from the proposed HW models to not encomoass the predictions from all of the GMPEs. 1204. Line 1401 Please identify the models listed in 1he legend to Figure 6.3 2-4 by their correct acronyms (i.e .* ASK14 instead of ASK2014). Please also justify in the text why it is acceptable for the predictions from the proposed HW models to not encompass the predictions from all of the GMPEs. 1205. Line 1406 Please identify the models listed in the legend to Figure 6.3.2-5 by their correct acronyms (i.e .* ASK14 instead of ASK2014). 1206. Line 1409 Please identify the models listed in the legend to Figure 6.3.2-6 by their correct acronyms (i.e., ASK14 instead of ASK2014). 1207. Line 1432 In Figure 6.3.2-11, please justify in the text why it is acceptable for the predic1ions from the HW models to not encompass all of the predictions from the simulations. 1208. Line 1438 In Figure 6.3.2-12, please justify in the text why it is acceptable for the predic1ions from the HW models to not encompass all of the predictions from the simulations. 1209. Line 1444 In Figure 6.3.2-13. please justify in 1he text why it is acceptable for the predic1ions from the HW models to not encompass all of the predictions from the simulations. 1210. Line 1448 In Figure 6.3.2-14. please justify in 1he text why it is acceptable for the predictions from the HW models to not encompass all of the predictions from the simulations. 1211. Lines 1472 (Figure The plot for the Idriss model is labeled "114." inconsistent with "ld14" 6.4.1-4a), 1475 elsewhere in the chapter. Please modify for consistency. (Figure 6.41-4b}. 1478 (Figure 6.4. 1-Sa}. and Line 1481 (Fiaure 6.5.1-Sbl 1212. Line 1529 In Figure 6.4.3-3, please explain the meaning of "NGAW2rv-MFn MODEL A" in the upper-left corner of the plot. 1213. Line 1552 In Figure 6.4.4-1, please explain the meaning of "NGAW2nc-MFn" in the upper-left corner of the plot. Please also explain what the different colors for the solid circles representing the GMPEs and their epistemic uncertainty refer to and what the grey circles represent. 1214. Line 1557 In Figure 6.4.4-2, please provide a legend for the color contours and explain 1he meaning of the grey ellipses and circles. 1215. Line 1567 In Figure 6.4.4-4, please define the axes labels and explain the meaning of "TOO 1 DCCP4 MODELA" in the upper-right corner of 1he bottom plot. 1216. Line 1586 (Figure The caption states that the GMPEs are in black, but the legend indicates 6.4.5-2b) a different color. Moreover. the color assignments differ from those in Figure 6.4.5-2a. Please modify for consistency between caption and leaend, and between 1he a and b oarts of 1he fiaure. 1217. Line 1623 In Figure 6.4.5-7, please justify why it is acceptable for the predictions from the proposed model to not encompass all of the predictions from the candidate GMPEs. The inference is that there is less than 5% confidence in those GMPE predictions that fall outside of the limits of the model. 1218. Line 1630 In Figure 6.4.5-8, please justify why it is acceptable for the predictions from the proposed model to not encompass all of the predictions from the candidate GMPEs. The inference is that there is less than 5% confidence in those GMPE predictions that fall outside of the limits of the model. 1219. Line 1666 In Figure 6.5.1-3, please explain what directivity model is used to make the plot and where the epicenter andfor hypocenter is located on the fault. 1220. Figure 6.7.2-2 Please label the vertical axis and explain the meaning of the term "ground motion factors" in the caption. 1221. Figure 6.7.2-3 Please identify the GMPEs associated with the respective colors, and the meanings of the different styles of grey lines, and make improvements to the legibility of the figure (note also that the figure did not appear in its entirety in the supplied PDF version). Also please exolain the meanina of the term "around motion factors" in the caotion. 1222. Figure 6.7.2-5 Please label the vertical axis and explain the meaning of the term "ground motion factors" in the caption. 1223. Figure 6.7.2-6 Please identify the GMPEs associated with the respective colors, and explain the meaning of the term "ground motion factors" in the caption. CHAPTER 7-GMC Models for the Sigma: Overview and Methodology 1224. Lines 8-9 Please note that by the sigma terminology of Al Atik et al. (201 O) "single-station within-evenf' standard deviation should be "single-site within-event" standard deviation. Please consider consistently using the terminoloav of Al Atik et al. 120101. 1225. Line 74 Please consider assigning the Zhao et al. (2006) model the acronym used in Chapter 6 (i.e., ZH06) as shorthand in the remainder of the chapter. 1226. Line 84 Please add the missing words in this sentence (which currently reads "and chose through the). 1227. Line 87 Please consider revising "smooth" to "constant. 1228. Line 155 Please consider using a different word than "proponent" on this line and elsewhere in the chapter to explain the different Tau and Phi models so as not to confuse them with models that have been proposed by Prooonent Exoerts (PEsl 1229. Line 177 Please rewrite the sentence beginning with The mean ' values ... " to better convey its meaning. The second half of this sentence appears to be incomplete. 1230. Line 183 Please correct the figure citation. which should be to Figures 7.2.3-2 and 7.2.3-3 (not "7.2.3-3 and 7.2.3-3"). 1231. Line 191 Please replace the term "proponent" with the term "candidate" to be consistent with terminology used elsewhere in the report. 1232. Line 195 Please replace the term "proponent" with the term "candidate" to be consistent with terminology used elsewhere in the report. 1233. Line 197 Please rewrite the final sentence of the paragraph to clarify its meaning (i.e .. a "value" cannot be similar to a "model," so it is not clear what point the sentence is trvina to convevl. 1234. Line 202 Please change oss to a,. 1235. Line 207 Please replace the term proponent" with the term candidate" to be consistent with terminology used elsewhere in the report. 1236. Line 232 Please describe the type of distribution used in the simulation. 1237. Line 269 Please indicate whether Dawood et al. (2015)" should be replaced with "Dawood et al., 2014 -in press .. and, if not, please provide the reference to the former. 1238. Lines 271-275 This paragraph appears to be contradictory and the Tl Team decision to use a magnitude-independent Phi_ss is not well supported by the first sentence in the paragraph and the results in Figures 7 3.2-1. Please expand this paragraph to better discuss and justify the decision to use a mac:mitude-independent model for Phi ss. 1239. Line 273 Please correct the inconsistency between the phrase "shown ... for four spectral periods" and the list (PGA, 0.1,0.5, 1.0,3.0 sec), which (like the figure itself) includes five periods (PGA in addition to the four given spectral periods). 1240. Line 276 Please explain why the Phi_ss values of the GLOBAL datasets for each GMPE are only shown for five periods in the figures and indicate, if only five values were used in the analysis. why Phi_ss values for the other oeriods are not used. 1241. Line 320 Please describe how CV(<Jl, * .) = 0.12 was derived. 1242. Line 388 Please avoid the use of the first person "us." 1243. Line 396 The statement that the between-event residuals were provided by the NGA-West2 developers is contradictory to the statement on Lines 404-405 that the Tl Team calculated the residuals. Please rewrite the text to remove this contradiction. 1244. Line 404 Please avoid the use of the first person "we." Since the use of first person has appeared several times in this chapter, please search the entire chapter for other uses of first person and convert them to third oerson. 1245. Line 407 This statement is confusing and again suggests that the between-event residuals provided by the developers are perhaps being used. Please consider rewriting or expanding this entire section to make the process of develooina the LO sinale-oath standard deviations less confusina. 1246. Line415 Please change oW;1 to oW;,. 1247. Line 730 In the Figure 7.2.4-4 caption, please consider replacing the word "proponent" with "candidate" to be consistent with how these models are referred to elsewhere in the reoort. 1248. Line 744 In the Figure 7 2 5-1 caption, please consider replacing the word "proponent" with candidate" to be consistent with how these models are referred to elsewhere in the report. 1249. Line 469 Please explain what is the first issue. 1250. Line 784 In Figure 7.3.2-3, please consider showing the periods with average "no-Lin et al. Data" to show that these values are also bracketed by the low and hiQh proposed values. 1251. Line 812 In the Figure 7.3.3-1a caption, please describe what the black solid and dashed lines represent. Also, in this and many otherfi11ures there are error bars on the symbols. but no mention of them in the legend or the caption. Please define the meaning of the error bars in this and other figures in this chapter and for similar figures elsewhere in the report where thev miaht aooear. 1252. Line 821 In the Figure 7 3 3-1 b caption. please describe what the black solid and dashed lines represent. 1253. Line 898 In Figure 7.4.2-1, this figure clearly demonstrates that the assumption that the standard deviation is constant at low and high periods is totally unsupported by the data (note that the values at 0.2 sec were not used because of reliability issues). Please further justify in the text why it is appropriate to extrapolate the first and last values as constant values to lower and higher periods and why the uncertainty should not become larQer at low and hiqh periods Qiven this added uncertainty. CHAPTER 8-Median GMC Models: DCPP Sources 1254. Section 8.2.2. There does not appear to be a reference to Figure 8.2-3. Please check general comment and add a reference to this figure if one is missing. 1255. Lines 60-61 Please explain the bases for the values used to define the three branches and their weights included in the second node of Figure 8.2-3 1256. Line 100 This is not necessarily true for the Akkar et al. (2014a,b) and Bindi et al. (2014a.b) GMPEs that were developed using subsets of the RESORCE database and with at least some interaction between them under the ausoices of the SIGMA oroiect. Please clarifv this statement. 1257. Line 125 Please add the missing word "models" after "common-form". 1258. Line 167 Please improve clarity by adding a sentence break after the word "model." 1259. Lines 293-295 Please reference where in the report the evaluation of ld14 was done to determine that it was unreliable for R1wP < 3 km at large magnitudes. 1260. Line 302 Please indicate what models are being compared in Figure 8.4-8. The discussion references both the common-form models and the candidate GMPEs and it is not clear which is being referred to when not explicitly stated in the text. 1261. Line 310 Contrary to this sentence, curves corresponding to the epistemic uncertainty are not included in Figure 8.4-9. Please add the curves or modifv this sentence to remove reference to epistemic uncertaintv. 1262. Line 355 Please provide evaluations or provide a cross reference in support of the conclusion that "differences in the magnitude and distance scaling will also imoact the ranae of the hazard. 1263. Lines 360-361 Please explain what will need to be done if in the future the hazard model is changed. For example. will an evaluation of the GMC model need to be redone because its validity was based. in part. on the hazard calculated from a specific hazard model (i.e., hazard-calibrated)? If that is the case, it is important that such a caveat be clearly communicated in the report. Please note that there are other instances in this and other chapters where hazard was invoked as demonstrating that the range in the models is adequate, which should also be included as part of this comment. 1264. Lines 367-370 Please explain why the versions of the candidate GMPEs with added epistemic uncertainty are not considered in the comparison. 1265. Line 388 Figure 8.4-7 is missing or skipped over Please correct this oversight. 1266. Figure 8.2-2 Please correct the weight for "Sim_DC-MED," (i.e., shouldn't it be 0.25?). 1267. Line 522 In Figure 8.4-1, please provide labels for the color legend bars and define what the light grey ellipses and points represent. 1268. Line 533 In Figure 8.4-2, please provide labels for the color legend bars and define what the light grey ellipses and points represent. 1269. Line 547 In Figure 8.4-3, please explain what DCPP Model A is, given that there appears to be only one DCPP model. 1270. Line 569 In Figure 8.4-6, there does not appear to be any dashed black" lines. Please revise the caption to refer to the actual color scheme used in the fiaure. 1271. Line 580 In Figure 8.4-8, there does not appear to be any dashed black" lines. Please revise the caption to refer to the actual color scheme used in the fiaure. 1272. Line 594 In Figure 8.4-9, there does not appear to be any "dashed black" lines. Please revise the caption to refer to the actual color scheme used in the fiaure. 1273. Line 645 In the Figure 8 4-14 caption, please describe what models the phrase "individual models refer to. 1274. Line 651 In the Figure 8 4-15 caption, please describe what models the phrase "individual models refer to. 1275. Line 656 In the Figure 8 4-16 legend, please refer to the various models by the acronyms used throughout the report (e.g., ASK14 instead of ASK). 1276. Line 662 In the Figure 8 4-17 legend, please refer to the various models by the acronyms used throughout the report (e.g., ASK14 instead of ASK). 1277. Line 665 In Figure 8.4-18. please define what the light grey lines represent in the legend or the caption. 1278. Line 670 In Figure 8.4-19. please define what the light grey lines represent in the legend or the caption. CHAPTER 9-Median GMC Models: PVNGS Sources 1279. Line 38 Please follow the standard practice of numbering figures in the order in which they are first called in the text, which is not the case with the figure called on this line. 1280. Line 54 Chapter 6 of this report and the report on the SSC model use the term "virtual fault", rather then "pseudo fault." Please revise for consistency with those other usaaes. 1281. Lines 74-75 The Akkar et al. (2014a,b) and Bindi et al. (2014a.b) GMPEs were developed using subsets of the RESORCE strong-motion database under the auspices of the SIGMA project. Please indicate that these two models are likely correlated. although perhaps not to the extent of the NGA-West2 models Please also note that this is not an issue. since epistemic uncertainty was applied to these models as well as to the NGA-West2 models. 1282. Line 108 Please specify the type of "residual" (i.e., between-event). 1283. Lines 173-174 The sentence beginning "The limitation ... " is confusing. Please reword it or expand it to make its meaning clearer. 1284. Line 187 Please make it clear which mechanism each of the weights refers to. 1285. Line 256 Please correct the figure reference; the reference to Figure 9.1-10 should actually be to Figure 9. 1-9. 1286. Line 371 Please correct the figure reference on this I ine (it should be 9. 1-19 ). 1287. Lines 475-476 Please indicate where the technical justification and bases for these statistical weights are given (i.e., Appendix P). 1288. Lines 478-481 The stated justification seems weak; there are few recordings at 200 to 400km distance range in the ground-motion database. On the other hand. it would appear that there is no need to consider directivity because its effect. as modeled in CY14, is zero at such large distances. Please revise to clarify the justification for the Tl Team's iudament 1289. Line 545 In the heading of the last column in Table 9 .1-1 , please replace the term "SFo** with "SOF" to represent style of faulting. 1290. Line 557 In Figure 9.1-2a. please label the color legend bars and describe what the light grey ellipses and circles are on the plots. 1291. Line 567 In Figure 9.1-2b. please label the color legend bars and describe what the light grey ellipses and circles are on the plots. 1292. Line 577 In Figure 9 .1-3a. please label the color legend bars and describe what the light grey ellipses and circles are on the plots. 1293. Line 587 Figure 9.1-3b. please label the color legend bars and describe what the light grey ellipses and circles are on the plots. 1294. Line 607 Please provide a specific reference to "Akkar et al." 1295. Line 637 In Figure 9.1-8, the plots do not appear to have any "dashed black" lines. Please revise the text to better describe the lines. 1296. Line 645 In Figure 9.1-9, the plots do not appear to have any "dashed black" lines. Please revise the text to better describe the lines. 1297. Line 653 In Figure 9. 1-10, the plots do not appear to have any "dashed black" lines. Please revise the text to better describe the lines. 1298. Line 661 In Figure 9. 1-11, the plots do not appear to have any "dashed black" lines. Please revise the text to better describe the lines. Please also further justify in the text why it is acceptable for some of the predictions from the GMPEs to fall outside of the range of the representative models at some periods. Note the concern in previous comments of using only the hazard distribution alone to justify the range in the representative suite of models. 1299. Line 709 In the Figure 9 1-13 caption. please describe what is meant by "individual models," and consider making changes such that the upper and lower parts of the figure have the same vertical scale. 1300. Line 714 In the Figure 9.1-14 caption, please describe what is meant by "individual models." 1301. Line 718 In the Figure 9.1-15 caption, please describe what is meant by "individual models." 1302. Line 724 In the Figure 9. 1-16 caption, please describe what is meant by "individual models." 1303. Line 729 In the Figure 9.1-17a caption, please describe what is meant by "selected models." Please consider using a consistent set of terminology for the different types of models that are described throughout the report to make it less confusing to the reader. Please also use a consistent set of acronvms in the leaend (e.a., ASK14 instead of ASK). 1304. Line 738 In the Figure 9. 1-17b caption, please describe what is meant by "selected models." Please also use a consistent set of acronyms in the legend (e g. ASK14 instead of ASK) 1305. Line 742 In the Figure 9. 1-18a caption, please describe what is meant by .. selected models." Please also use a consistent set of acronyms in the legend (e q. ASK14 instead of ASK) 1306. Line 748 In the Figure 9. 1-18b caption, please describe what is meant by .. selected models." Please also use a consistent set of acronyms in the legend (e q. ASK14 instead of ASK) 1307. Line 759 In Figure 9 .1-19. please use a consistent set of acronyms in the legend (e.g., ASK 14 instead of ASK). 1308. Figure 9.2-1 Please correct the abbreviation for the Idriss (2014} model to be consistent with usage elsewhere in the report. CHAPTER 10-'t Model Logic Tree for both DCPP and PVNGS 1309. Lines 25-26 Please also mention that the standard deviations of ASB14 and Bi14 are independent of magnitude, which was an important property of the models that the Tl Team used to reject them. 1310. Line 38 Although the use of the term "proponenr in this context is technically correct, it is inconsistent with the term "candidate" used throughout the report to identify such proponent models. Please consider replacing .. proponent" with .. candidate .. to be consistent with the description of such models throughout the report. 1311. Line 47 Please add the term .. scaled" before "Chi-square distribution." 1312. Lines 51-53 The three-point approximation scheme (as described in Appendix P) applies (0.2. 0.6. 0.2) weighs to the (5th. 50th. 95th) percentiles. Please explain the appropriateness (or point to a place where such explanation was given) of giving a 0.6 weight to the central branch representing the mean (which may not be the so** percentile of a Chi-square distribution). CHAPTER 11-4> Model Logic Tree: DCPP 1313. Line 27 Please clarify if interpolation and extrapolation were also needed for the California-only data subset, which includes data at the full set of spectral periods. 1314. Line 53 Statistical evaluation of the standard error of o .. was not given in Appendix P. Please verify and correct the cross reference as needed. 1315. Lines 53-58 Please refine this paragraph to give a clear and accurate summary of the approach described in Section 7.3.1. 1316. Line 64 Please qualify the term "correlated .. in a way that is similar to Lines 4-5 of Chapter 12. 1317. Line 71 Please consider revising the term "intra-event" to "within-event" to be consistent with the terminology generally used throughout the report. 1318. Lines 78-79 and 88-Please define the level of significance for the presumed departure from 89 normality. It might be obvious to the Tl Team, but not necessarily to the reader. that a point falling outside the 95% confidence interval can be considered to depart from normality at the 5% level of significance. Besides. others might consider "significant" to be at the 10% level of significance. 1319. Line 105 Please be specific whether the same weights of the mixture models that were found to be appropriate for CY14 are "similar or the "same" as found for ASK14. 1320. Lines 108-112 Please provide a context for this paragraph. 1321. Line 127 Please insert a space after o. 1322. Line 133 Please consider revising the term "intra-event to "within-event to be consistent with the terminology used throughout the report. 1323. Line 188 In the Figure 11-2 caption, please consider revising the term "intra-event" to within-event" to be consistent with the terminology used throughout the report and define the meaning of the term "normalized " Please also define the solid and dashed red curves. In addition. note that panel b) is stated as being forT=2 sec. but the y-axis label indicates it is for T=0.5 sec. Please correct this inconsistencv. 1324. Line 191 In the Figure 11-3 caption. please describe whattype of "residuals" are referred to in this figure. Please also define the solid and dashed red curves. 1325. Line 194 In the Figure 11-4 caption, please describe what type of "residuals are referred to in this figure. Please also define the solid and dashed red curves and provide the missinq red curves on the riqht plot. 1326. Line 201 In Figure 11-5, both of these plots appear to be incomplete and the left plot is not consistent with the right plot. Please correct these plots to be consistent with other similar plots in the chapter. 1327. Line 212 In Figure 11-6, both of these plots appear to be incomplete and the left plot is not consistent with the right plot. Please correct these plots to be consistent with other similar plots in the chapter. 1328. Line 218 In Figure 11-7. both of these plots appear to be incomplete and the left plot is not consistent with the right plot. Please correct these plots to be consistent with other similar plots in the chapter. CHAPTER 12-qi Models Logic Tree: PVNGS 1329. Lines 3-5 The first paragraph appears to be awkwardly placed. Please consider placing this paragraph in a more appropriate place in the chapter. 1330. Line 45 Please remove the reference to DCPP, since this chapter addresses the Phi model for PVNGS. 1331. Line 69 Please correct "biased-corrected" to bias-corrected. 1332. Line 90 Lines 486 and 487 on Page 7-16: CV=O. 17 of was based on the variability and the mean ofo ... estimates for the four individual GMPEs. Please clarify or correct the statement .. based on sample size" in the case of 1333. Line 146 Please replace "02" with "0.2." CHAPTER 13-Total Sigma Model 1334. General The use of the term "total sigma" instead of the more accurate "total single-site sigma" tends to neglect the fact that only a single-site sigma model was adopted. Please consider replacing the term "total sigma" with "total sinale-site sioma" to emphasize this point. 1335. Line 7 Although the Greek letter "q1** and 1he Greek symbol "o .. both represent Phi. it is common in engineering seismology to use the latter. which has also been used elsewhere in this report to represent Phi. Please select one of these letters/symbols to represent Phi and use it consistently throuahout the reoort in order to avoid confusion. 1336. Line 10 Eq (13-1) is very generic and does not represent the actual aleatory variability models that are proposed. Please consider replacing this equation with two equations: one that represents the total single-site sigma without path terms and one that represents the total single-site siama with path terms, as discussed in the text that follows the equation. 1337. Lines 30-31 Although the use of only a total [single-site) standard deviation epistemic logic tree is conceptually fine. it appears to prevent the ability to test the sensitivity of the hazard results to the individual between-event and single-site within-event epistemic uncertainty models. Since sensitivity to each type of model is provided in Chapter 14, please explain how someone else can test this sensitivity given that the final model presents onlv a sinqle total lsinqle-sitel siqma model. 1338. Line 55 Please replace the term cumulative distribution" with the more accurate term "cumulative distribution function" 1339. Line 57 Please add a sentence to explain the utility of Eq (13-3). 1340. Line 61 Please correct the missing factor of two in Eq (13-5) (this typographical error is noted here just as a reminder: it has already been noted by the Tl Team). 1341. Lines 62-63 Please further describe these analyses or provide a reference where the results of these analyses can be found 1342. Line 66 Please correct a possible typo: should cr .. be changed to<jl,.,? 1343. Line 75 Please correct a possible typo: should qi" be changed to cr,.,? 1344. Line 77 Please correct the typo ("bi-linear") and add the missing word (i.e .. missing "to" in "leads to"). 1345. Line 79 The Tl Team responded to PPRP's Comment 175 by adding the sentence "Appendix P presents typical examples of the calculations." However, such example calculations were not given in Appendix P. Please provide these missing calculations. 1346. Lines 89 and 90 To be consistent with the usage in the embedded table on Line 93, please consider adding subscript SS" to symbol a. 1347. Line 90 Please assign the embedded table a number and a title so that it can be referenced by table number if needed. and correct any subsequent table numberina as necessarv. 1348. Lines 98. 99 and 100 Please explain why directly computed a" at magnitudes between M 5 and M 7 at 0.1 units were not used in fitting Eq (13-8)? 1349. Lines 102-103 Please provide a reference for the statement beginning "Minimization of the difference . ". 1350. Line 118 Please check the correctness of the reference to Section 13. 1; should it be Section 13.2? 1351. Line 154 Please clarify whether "the method" refers to the semivariogram analysis method (ie .. the current sentence construction leaves some ambiguity). 1352. Line 160 The Tl Team presented its evaluation and decision on the modeling of the effects of spatial correlation on cr.,, for the magnitude-independent cr .. model only. Please also provide discussions for the magnitude-dependent a,, models. 1353. Line 184 Please repair the typos on this line. 1354. Lines 267. 270 and Please indicate in each figure which branch includes the spatial-273 correlation effect on o". CHAPTER 14-Hazard Sensitivity 1355. Lines 7-8 It appears awkward to state that the hazard sensitivity analyses for the final GMC model was done on preliminary versions of the SSC models without providing some sort of caveat. This can be avoided by stating that ii is the responsibility of the individual NPPs to conduct thorough sensitivity analyses for their individual sites and that the sensitivity results provided herein are for demonstration purposes and for purposes of makina hazard-informed decisions 1356. Line 60 There is no mention of deaggregation in the introduction to this chapter. Please introduce this concept and discuss what it is used for in the introduction to the chapter prior to presentinq the deaaqreqation results. 1357. Line 81 Please add the term .. mean" before "hazard level" to be clear that the results represent the mean and not some other fractile (e.g., the median) hazard. Hazard is used without prefacing it by mean many times throughout the chapter. If mean is not added to all of the instances where the hazard level is mentioned, then please state that this is the case for the remainder of the chapter in order to avoid confusion. 1358. Line 88 Please consider rewriting the caption (i.e., the "hazard at hazard" juxtaposition somewhat obscures the meaning). 1359. Line 103 Please define the term "sensitivity case and be as specific as possible about what figure(s) are being referenced in the discussion. 1360. Line116 The text on this line states that HW Models 5, 11 and 21 were selected for the 0.5 Hz tornado plots. but the figure legends for the 0 5 Hz cases indicate that Models 5. 13 and 23 were used. Please check and correct as necessarv. 1361. Line 151 Although the sigma model started as separate Tau and Phi_ss models. in the end a single total single-site sigma model was used. Please acknowledge that here and describe that the individual Tau and Phi_ss models were used for purposes of the sensitivity analyses. Also describe how the user of the model can conduct a similar sensitivity analysis usina their own hazard code. 1362. Line 152 This statement implies that "Model 1" is always the central model of the representative suite of models. If there is some numbering convention for these models, please describe that convention. 1363. Line 168 It is awkward that the first sensitivity analysis appears on the fifth line of the tornado plot. Please consider here and elsewhere in the chapter discussing the sensitivity cases starting with the top line of the tornado plot and descending down the plot to make the discussion less confusing. 1364. Line 247 The terminology used here is confusing, at best, and doesn't seem to have a useful purpose. The dichotomy "seismogenic sources" versus "tectonic sources" does not seem meaningful. Why are the former not simply called areal sources. since the other type -tectonic sources -are also seismogenic sources? Further, in the next line, "Seismic source input" is used: what is the difference between seismic source and seismogenic source? Finally, in Line 251. "areal seismic source" is used. This paragraph needs to be rewritten with consistent, conventional terminology. 1365. Line 266 There is some confusion as to the use of the term "Sonora Basin and Range. The SSC model uses the term .. Southern Basin and Range". Here. you seem to indicate that the "Sonora" component of this term is derived from the Lettis (2013) SSHAC2 report. This needs to be made clearer, and it would also help if it were made clear that this region is now referred to as the Southern Basin and Range. especially as the Mexican Highland Basin and Range is in Sonora. Mexico. 1366. Line 270 Baja is not the name of the Mexican State that occupies the northern hal1 of the Baja California peninsula. It is Baja California. If this term is in reference to that used in Lettis (2013}. please make that more clear by also referencing its current usage as Baja California in the SSC report. 1367. Lines 27 4-302 Some of the faults have "fault" in their listed name. whereas others do not. Is there a reason for this. and if so. please explain. Alternatively, make them consistent. 1368. Line 401 Please describe what is meant by the term "wider tail" in this context. 1369. Line 449 Here it states that the discussion will only address the 0.5 Hz SA sensitivities. whereas in the following text. the figures addressing the 5 Hz sensitivities are also cited (Lines 462-463. 466 and 477). Please clarify. 1370. Lines 451-452 Please be as specific as possible about what figure(s) are being referenced in the discussion Please also be more specific when describing the sensitivity cases. For example. the first sentence mentions "the first sensitivity analysis" and the second sentence mentions "these sensitivity cases, without indicating how these two descriptions are related. Since there are a lot of repetitive statements in the text describing the sensitivity analyses and/or sensitivity cases. this comment applies throughout the chapter: please make it clear what sensitivity analysis and/or case is being discussed at any given time and where that analvsis and/or case can be found on the tornado olot. 1371. Line 465 Section 7.4.1 does not include a discussion of additional epistemic uncertainty at large magnitude. Please provide the correct cross-reference. 1372. Line 468 Please add "types" between "two" and "common form models" in order to avoid confusion. 1373. Line 506 Please clarify what "Model 1" refers to on this line. 1374. Line 510 Please consider replacing the term "average" with the term "centrar so as not to imply that it is intended to represent the mean (average) hazard. 1375. Line 511 Figure 14.3-10a is cited on this line, but the discussion appears to refer to the case shown in Figure 14.3-9. Please check and correct as acoropriate. 1376. Line 517 Figure 14.3-9b is cited on this line, but the discussion appears to refer to the case shown in Figure 14-1 Oa. Please check and correct as acoropriate. 1377. Lines 594-595 Please add "types" between "two" and "common form models" in order to avoid confusion. 1378. Lines 609 and 617 Figures 14.3 (a and b} are cited. but in Line 605. it is stated these would not be discussed further. Please clarify. CHAPTER 15-Application Guidelines and Limitations 1379. Line 5 Please provide a cross reference to the adopted kappa value of 0.041 s. 1380. Lines 5-8 Please provide a cross reference to the section where evaluations are presented to support the claim that epistemic uncertainty in kappa is captured by the variation in high-frequency spectral shape within the SWUS GMC common-form models 1381. Lines 12-14 Please give the purpose for providing a representative Vs and density profile and what they can or should be used for. or delete this discussion from the report Without such a statement of purpose. it is ambiguous why these profiles are presented. For example, if they are provided for purposes of documenting what was used to estimate the host kappa values for the NGA-West2 GMPEs, then their discussion should be part of the appendix that discusses the host kappa value determination If they are meant to be representative of the site response predicted by the site terms in the NGA-West2 GMPEs. that has not been shown to be the case for these GMPES and is certainly not the case for the European or Japan GMPEs, which are likely represented by totally different Vs and density profiles. CHAPTER 16-References 1382. Please carefully review these references for completeness and accuracy and for consistency with the references provided in each chapter. February 24, 2015 Dr. Carola Di Alessandro SWUS Project Manager GeoPentech, Inc. 525 N. Cabrillo Park Drive, Suite 280 Santa Ana, CA 92701

Subject:

Participatory Peer Review Panel Closure Letter, Southwest United States Ground Motion Characterization Level 3 SSHAC Project

Dear Dr. Di Alessandro:

The Participatory Peer Review Panel (PPRP, also referred to herein as the "Panel") for the Southwest United States (SWUS) Ground Motion Characterization (GMC) Project is pleased to issue this PPRP Closure Letter. Herein we describe our participation in the SWUS GMC SSHAC Level 3 project and present our findings. Pursuant to the guidelines for a SSHAC Level 3 study (NUREG/CR-6372; NUREG-2117), the PPRP was engaged at all stages of the project, including review of the final Project Plan, Workshop agendas and participant lists; the planning of the evaluation and model integration activities; and review of the project documentation. Throughout the project, the Panel reviewed and provided regular feedback on both the process followed, and the technical assessments made, by the Technical Integrator (Tl) Team. By this letter the Panel documents the activities it has performed in the course of its review, its assessment of the process followed relative to SSHAC Level 3 expectations, and its assessment of the technical rationale underlying the GMC model. PPRP Activities in Support of the SWUS GMC Review In a SSHAC Level 3 study, the PPRP fulfills two roles. The first is that of technical review, in which the Panel ensures that the full range of data, models and methods are considered and that technical decisions and judgments are adequately justified and documented. The second is that of process review, under which the Panel ensures that the study maintains conformity with the SSHAC Level 3 guidelines. To fulfill these roles, the Panel requires adequate opportunities to gain understanding of the data being used, the analyses being performed, the Tl Team's evaluations of data and models, and the technical justifications for the Tl Team's model decisions. The table below summarizes the formal project activities in which the Panel participated. Fulfilling these roles also requires the Panel to provide regular feedback to the Tl Team during the course of the project. In addition to verbal feedback during Working Meetings and Workshops, the Panel provided written comments and recommendations at key stages of the project. Those written submittals are also noted in the table. 1 Date I PPRP Activity June 21, 2012 !Working Meeting #1 (Planning). All PPRP members attended. July 18, 2012 Working Meeting #2 (Planning}. All PPRP members attended. Auqust27, 2012 Kick-off MeetinQ. All PPRP members attended. September 17, 2012 PPRP submittal of written comments on the Project Plan. October 8, 2012 !Working Meeting #3. PPRP representatives attended as observers. November 3, 2012 IPPRP submittal of written comments on revised Project Plan. November 29, 2012 PPRP submittal of PPRP endorsement letter for Project Plan. December 10, 2012 WorkinQ MeetinQ #4. PPRP representatives attended as observers. February 11, 2a 13 Working Meeting #5. PPRP representatives attended as observers. March 19-21, 2013 #1: Critical issues and Data Needs. All PPRP members attended as bservers. The PPRP provided verbal feedback to the Tl Team at the end of ach day of the Workshop April 12, 2013 !Working Meeting #6. PPRP representatives attended as observers. April 21, 2013 PPRP submittal of written comments on Workshop #1. May 23, 2013 WorkinQ MeetinQ #7. PPRP representatives attended as observers. June 24, 2013 Working Meeting #8. PPRP representatives attended as observers. July 16, 2013 !Working Meeting #9. PPRP representatives attended as observers. August 21, 2013 !Working Meeting #10. PPRP representatives attended as observers. October 2, 2013 Working Meeting #11. PPRP representatives attended as observers. October 15, 2013 WorkinQ MeetinQ #12. PPRP representatives attended as observers. October 22-24, 2013 Workshop #2: Proponent Models and Alternative Interpretations. All PPRP members attended as observers. The PPRP provided verbal feedback to the Tl !Team at the end of each day of the Workshop. November 26, 2013 Working Meeting #13. PPRP representatives attended as observers. December 3, 2013 PPRP submittal of written comments on Workshop #2. January 2, 2014 Working Meeting #14. PPRP representatives attended as observers. January 28-29, 2014 Special Workinq MeetinQ. All PPRP members attended as observers. March 3, 2a14 Working Meeting #15. PPRP representatives attended as observers. March 10-12, 2014 #3: Preliminary GMC Models and Hazard Feedback. All PPRP embers attended as participants. The PPRP provided verbal feedback to the Team at the end of each day of the Workshop. March 24, 2014 !Working Meeting #16. PPRP representatives attended as observers. April 21, 2014 PPRP submittal of written comments on Workshop #3. May 14, 2014 PPRP Closure Pre-Briefinq. All PPRP members attended as participants. July 17-18, 2014 PPRP Closure Briefinq. All PPRP members attended as participants. December 13, 2014 Submittal No. 1 of PPRP written review comments on SWUS GMC Report: Comments on SWUS GMC Report Rev.a. Chapters 7, 10, 11, 12, 13, and l/\ppendices L, M, N, and R. December 16, 2014 PPRP and Tl Team, to discuss the PPRP written review omments, Submittal No. 1. January 5, 2015 Submittal No. 2 of PPRP written review comments on SWUS GMC Report: Comments on SWUS GMC Report Rev.a, Chapters 6, 8, 9, 14, and Appendices H, I, J, K, 0, and Q. January 7, 2015 [Teleconference, PPRP and Tl Team, to discuss the PPRP written review comments, Submittal No. 2. January 26, 2015 rTeleconference, PPRP and Tl Team, to discuss the main modifications introduced in SWUS GMC Report Draft Rev.1. February 9, 2015 [Teleconference, PPRP and Tl Team, to discuss observations from PPRP partial review of SWUS GMC Report Draft Rev.1. February 16, 2a15 !Teleconference, PPRP and Project Manager to discuss project completion schedule. February 20, 2a15 Submittal No. 3 of PPRP written review comments on SWUS GMC Report: Comments on SWUS GMC Report Draft Rev.1. 2 The PPRP finds that the level of ongoing review it was able to undertake, and the opportunities afforded the PPRP to provide feedback to the Tl Team, met the expectations for a SSHAC Level 3 study. Interactions with the Tl Team provided ample opportunity for the Panel to gain an understanding of the technical bases for the Tl Team's evaluations. The Panel also was given adequate opportunity to query the Tl Team, especially in Workshop #3 and in the Pre-Closure Briefing and Closure Briefing, to assess the justification provided for their model decisions. The Tl Team provided written responses to each formal PPRP submittal, and in nearly every case the PPRP and Tl Team subsequently discussed the comments and replies in a conference call or Working Meeting. SSHAC Process Review NUREG-2117 describes the goal of a SSHAC process as being "to carry out properly and document completely the activities of evaluation and integration, defined as: Evaluation: The consideration of the complete set of data, models and methods proposed by the larger technical community that are relevant to the hazard analysis. Integration: Representing the center, body, and range of technically defensible interpretations in light of the evaluation process (i.e., informed by the assessment of existing data, models, and methods)." During the Evaluation activities, the Tl Team considered new data, models and methods that have been introduced within the technical community since the previous seismic hazard studies were conducted for nuclear power plants in California and Arizona. The Team evaluated newly available ground motion databases, ground motion prediction equations (GMPEs), and ground motion simulation techniques. Notably, the Tl Team evaluated methods for the representation of non-Gaussian aleatory variability, as well as newly available methods for the visualization and characterization of epistemic uncertainty in ground motion prediction. The PPRP finds that the Tl Team's evaluation was consistent with the expectations for a SSHAC Level 3 study, and, apart from the specific reservation noted at the end of this section, was adequately documented. The Integration phase entails thoroughly documenting the technical bases for all elements of the GMC model, to provide assurance that the center, body and range of technically defensible interpretations have been captured. The Tl Team used a new statistical technique to generate a suite of representative models for median ground motion prediction that collectively represent the epistemic uncertainty in ground motion more broadly than do the published GMPEs alone. This technique is combined with a new method to select and weight the predictions of the expanded suite of models. The Tl Team's method for assigning weights is based on consideration of appropriate data 3 sets and numerical simulations, with adequate justification. The Tl Team's model for aleatory variability and weighting of alternative aleatory models is also adequately justified. The PPRP finds that the Tl Team's GMC model integration is consistent with the expectations of a SSHAC Level 3 project, and, apart from the specific reservation noted in the next paragraph, was adequately documented. The PPRP's reservation with respect to the documentation of the evaluation and integration phases of the study is based on the Tl Team's inability to produce a final report based on the last set of comments from the Panel (Submittal No. 3, February 20, 2015) that were intended to improve the completeness and clarity of the documentation. The Tl Team was unable to revise the report in time for this letter to be issued in order to meet contractual obligations to provide written documentation to the utilities. The Tl Team did provide written responses to the Panel's comments and assured the Panel in writing that the final version of the report would take these comments into account. SSHAC Technical Review NUREG-2117 describes the PPRP's technical review role as follows: "The PPRP fulfills two parallel roles, the first being technical review. This means that the PPRP is charged with ensuring that the full range of data, models, and methods have been duly considered in the assessment and also that all technical decisions are adequately justified and documented. The responsibility of the PPRP is to provide clear and timely feedback to the Tl/TFI and project manager to ensure that any technical or process deficiencies are identified at the earliest possible stage so that they can be corrected. More commonly, the PPRP provides its perspectives and advice regarding the manner in which ongoing activities can be improved or carried out more effectively. In terms of technical review, a key responsibility of the PPRP is to highlight any data, models or proponents that have not been considered. Beyond completeness, it is not within the remit of the PPRP to judge the weighting of the logic-trees in detail but rather to judge the justification provided for the models included or excluded, and for the weights applied to the logic-tree branches." As summarized in the table above, the PPRP reviewed the Tl Team's evaluations of data, models and methods on multiple occasions, and through various means, including written communications, in-person meetings, teleconferences, and review of the project report. The Panel was given adequate opportunity to question the Tl Team concerning details of their analysis, and provided feedback verbally and in writing. The Tl Team was responsive to the technical input from the Panel. The Tl Team's responses included evaluating additional data sets suggested by the Panel, undertaking additional 4 analyses to address specific Panel technical questions or concerns, and examining and assessing alternative technical approaches suggested by the Panel. The PPRP therefore concludes that it has been afforded an adequate basis for technical assessment of the Tl Team's evaluations and model integration and finds that the project meets technical expectations for a SSHAC Level 3 study. Conclusion On the basis of its review of the SWUS GMC project, the PPRP finds that the project meets, with respect to both process and technical standards, the expectations for a SSHAC Level 3 study, with the reservation cited above. That reservation relates only to completeness of the documentation, which the Tl Team has assured in writing will be rectified in the final report. Sincerely, Steven M. Day Chair, PPRP Brian Chiou Member, PPRP Kenneth W. Campbell Member, PPRP . /""' ' -...-'°1 . . . I , *'JI, I / .* *

• f-/i t. ..,_,:.(, 1.(__ 1 i. .1 .* s-:> -// /-... * Thomas K. Rockwell Member, PPRP 5 From: Steven Day <sday@mail.sdsu.edu>

Subject:

non-mandatory comments Date: Monday, March 09, 2015 8:03 AM To: Carola DiAlessandro <carola dialessandro@geopentech.com> Cc: Steven Day <sday@mail.sdsu.edu>, Kenneth Campbell <ken.w.campbell@comcast.net>, Brian Chiou <brian chiou@comcast.net>, Thomas Rockwell <trockwell@mail.sdsu.edu> Attachments: Non-mandatory comments, BC.docx (13 KB) Hi, Carola. Please find attached some non-mandatory comments on SWUS report Rev2 .These are offered by PPRP members acting individually, and I am sending them to you informally in case they might aid your team in its editorial work. There is no obligation on your part to consider them. Steve March 10, 2015 Dr. Carola Di Alessandro SWUS Project Manager GeoPentech, Inc. 525 N. Cabrillo Park Drive, Suite 280 Santa Ana, CA 92701

Subject:

Participatory Peer Review Panel Closure Letter, Southwest United States Ground Motion Characterization Level 3 SSHAC Project

Dear Dr. Di Alessandro:

The Participatory Peer Review Panel (PPRP, also referred to herein as the "Panel") for the Southwest United States (SWUS) Ground Motion Characterization (GMC) Project is pleased to issue this PPRP Closure Letter. Herein we describe our participation in the SWUS GMC SSHAC Level 3 project and present our findings. Pursuant to the guidelines for a SSHAC Level 3 study (NUREG/CR-6372; NUREG-2117), the PPRP was engaged at all stages of the project, including review of the final Project Plan, Workshop agendas and participant lists; the planning of the evaluation and model integration activities; and review of the project documentation. Throughout the project, the Panel reviewed and provided regular feedback on both the process followed, and the technical assessments made, by the Technical Integrator (Tl) Team. By this letter the Panel documents the activities it has performed in the course of its review, its assessment of the process followed relative to SSHAC Level 3 expectations, and its assessment of the technical rationale underlying the GMC model. The PPRP issued a previous letter dated February 24, 2015. In that letter, the Panel noted that there were limitations in the completeness and clarity of the project documentation. Those limitations were noted as exceptions to the Panel's finding that the project successfully met SSHAC Level 3 expectations. Since that time, the Tl Team has produced a final report, designated Rev2, addressing the final set of comments from the Panel (PPRP Submittal No. 3, February 20, 2015). The Panel has reviewed Rev2 (including a short addendum supplied to the PPRP in draft form on March 9 which the Tl Team has assured in writing will be incorporated in the final version) and finds that all material concerns have been adequately addressed and are now closed, apart from one remaining exception that will be described at the end of the SSHAC Process Review section below. Two GMC models were developed for application to Diablo Canyon Power Plant (DCPP) and Palo Verde Nuclear Generating Station (PVNGS), respectively. The exception applies only to the GMC model for DCPP, and is not relevant to the case of PVNGS. 1 PPRP Activities in Support of the SWUS GMC Review In a SSHAC Level 3 study, the PPRP fulfills two roles. The first is that of technical review, in which the Panel ensures that the full range of data, models and methods are considered and that technical decisions and judgments are adequately justified and documented. The second is that of process review, under which the Panel ensures that the study maintains conformity with the SSHAC Level 3 guidelines. To fulfill these roles, the Panel requires adequate opportunities to gain understanding of the data being used, the analyses being performed, the Tl Team's evaluations of data and models, and the technical justifications for the Tl Team's model decisions. The table below summarizes the formal project activities in which the Panel participated. Fulfilling these roles also requires the Panel to provide regular feedback to the Tl Team during the course of the project. In addition to verbal feedback during Working Meetings and Workshops, the Panel provided written comments and recommendations at key stages of the project. Those written submittals are also noted in the table. Date PPRP Activity June 21. 2012 Working Meeting #1 (Planning). All PPRP members attended. July 18, 2012 Working Meeting #2 (Planning). All PPRP members attended. August27, 2012 Kick-off Meeting. All PPRP members attended. September 17, 2012 PPRP submittal of written comments on the Project Plan. October 8, 2012 Workinq Meetinq #3. PPRP representatives attended as observers. November 3, 2012 PPRP submittal of written comments on revised Project Plan. November 29, 2012 IPPRP submittal of PPRP endorsement letter for Project Plan. December 10, 2012 Working Meeting #4. PPRP representatives attended as observers. February 11, 2013 WorkinQ MeetinQ #5. PPRP representatives attended as observers. March 19-21. 2013 Workshop #1: Critical issues and Data Needs. All PPRP members attended as observers. The PPRP provided verbal feedback to the Tl Team at the end of each day of the Workshop April 12, 2013 Working Meeting #6. PPRP representatives attended as observers. April 21, 2013 PPRP submittal of written comments on Workshop #1. May 23, 2013 Working Meeting #7. PPRP representatives attended as observers. June 24, 2013 WorkinQ MeetinQ #8. PPRP representatives attended as observers. July 16, 2013 Working Meeting #9. PPRP representatives attended as observers. August 21, 2013 Working Meeting #10. PPRP representatives attended as observers. October 2, 2013 !Working Meeting #11. PPRP representatives attended as observers. October 15, 2013 Working Meeting #12. PPRP representatives attended as observers. October 22-24, 2013 Workshop #2: Proponent Models and Alternative Interpretations. All PPRP members attended as observers. The PPRP provided verbal feedback to the Tl [Team at the end of each dav of the Workshop. November 26, 2013 Working Meeting #13. PPRP representatives attended as observers. December 3, 2013 PPRP submittal of written comments on Workshop #2. January 2, 2014 Working Meeting #14. PPRP representatives attended as observers. January 28-29, 2014 Special Working Meeting. All PPRP members attended as observers. March 3, 2014 WorkinQ MeetinQ #15. PPRP representatives attended as observers. March 10-12, 2014 Workshop #3: Preliminary GMC Models and Hazard Feedback. All PPRP members attended as participants. The PPRP provided verbal feedback to the rTI Team at the end of each day of the Workshop. March 24, 2014 Working Meeting #16. PPRP representatives attended as observers. April 21, 2014 PPRP submittal of written comments on Workshop #3. 2 May 14, 2014 IPPRP Closure Pre-Briefing. All PPRP members attended as participants. July 17-18, 2014 PPRP Closure Briefinq. All PPRP members attended as participants. December 13, 2014 Submittal No. 1 of PPRP written review comments on SWUS GMC Report: Comments on SWUS GMC Report Rev .0, Chapters 7, 10, 11, 12, 13, and L, M, N, and R. December 16. 2014 rTeleconference, PPRP and Tl Team, to discuss the PPRP written review comments, Submittal No. 1. January 5, 2015 Submittal No. 2 of PPRP written review comments on SWUS GMC Report: Comments on SWUS GMC Report Rev.O. Chapters 6, 8, 9, 14, and Appendices H, I, J, K, 0, and Q. January 7, 2015 rTeleconference, PPRP and Tl Team, to discuss the PPRP written review comments. Submittal No. 2. January 26, 2015 !Teleconference, PPRP and Tl Team, to discuss the main modifications introduced in SWUS GMC Report Draft Rev.1. February 9, 2015 rTeleconference, PPRP and Tl Team, to discuss observations from PPRP partial review of SWUS GMC Report Draft Rev.1. February 16, 2015 rTeleconference, PPRP and Project Manager to discuss project completion schedule. February 20, 2015 Submittal No. 3 of PPRP written review comments on SWUS GMC Report: Comments on SWUS GMC Report Draft Rev.1. February 24. 2015 Submittal of Closure Letter based on Draft Rev.1 The PPRP finds that the level of ongoing review it was able to undertake, and the opportunities afforded the PPRP to provide feedback to the Tl Team, met the expectations for a SSHAC Level 3 study. Interactions with the Tl Team provided ample opportunity for the Panel to gain an understanding of the technical bases for the Tl Team's evaluations. The Panel also was given adequate opportunity to query the Tl Team, especially in Workshop #3 and in the Pre-Closure Briefing and Closure Briefing, to assess the justification provided for their model decisions. The Tl Team provided written responses to each formal PPRP submittal, and in nearly every case the PPRP and Tl Team subsequently discussed the comments and replies in a conference call or Working Meeting. SSHAC Process Review NUREG-2117 describes the goal of a SSHAC process as being "to carry out properly and document completely the activities of evaluation and integration, defined as: Evaluation: The consideration of the complete set of data, models and methods proposed by the larger technical community that are relevant to the hazard analysis. Integration: Representing the center, body, and range of technically defensible interpretations in light of the evaluation process (i.e., informed by the assessment of existing data, models, and methods)." During the Evaluation activities, the Tl T earn considered new data, models and methods that have been introduced within the technical community since the previous seismic hazard studies were conducted for nuclear power plants in California and Arizona. The 3 Team evaluated newly available ground motion databases, ground motion prediction equations (GMPEs), and ground motion simulation techniques. Notably, the Tl Team evaluated methods for the representation of non-Gaussian aleatory variability, as well as newly available methods for the visualization and characterization of epistemic uncertainty in ground motion prediction. The PPRP finds that the Tl Team's evaluation and the documentation thereof are consistent with the expectations for a SSHAC Level 3 study, apart from the specific reservation noted at the end of this section. The Integration phase entails thoroughly documenting the technical bases for all elements of the GMC model, to provide assurance that the center, body and range of technically defensible interpretations have been captured. The Tl Team used a new statistical technique to generate a suite of representative models for median ground motion prediction that collectively represent the epistemic uncertainty in ground motion more broadly than do the published GMPEs alone. This technique is combined with a new method to select and weight the predictions of the expanded suite of models. The Tl Team's method for assigning weights is based on consideration of appropriate data sets and numerical simulations, with adequate justification. The Tl Team's model for aleatory variability and weighting of alternative aleatory models is also adequately justified. The PPRP finds that the Tl Team's GMC model integration and the documentation thereof are consistent with the expectations of a SSHAC Level 3 project, apart from the specific reservation noted in the next paragraph. The Panel finds that the Tl Team's evaluation of directivity models has limitations. The Tl Team make use of a simplified directivity model to save computational time, and the final report adequately describes that model, how it is used, and some of its limitations. However, because the simplified model is unpublished, it is also necessary for the Tl Team to document that the simplified model is appropriate for the purpose for which it is applied, in the sense that it gives results that are essentially consistent with the published and peer-reviewed model that it is intended to approximate. The final report (in the March 9 addendum) documents the performance of the simplified model through comparison with results from a hazard calculation that uses the full, published directivity model. At hazard levels of 10-4 and above, the full model calculation confirms the conclusion obtained using the simplified model. At hazard levels below 10-4, however, the difference in calculated hazard between the full model and the simplified model increases with decreasing hazard level. This increasing trend has not been satisfactorily explained, has not been explored beyond the single fault case provided in the March 9 addendum, and has not been quantified in terms of impact on equal-hazard spectra at hazard levels of 10-5 and lower. Because the key rationale for the zero weighting of the directivity branch in the GMC model for periods longer than 0.5 s (the period range where the directivity effect applies) is the weak sensitivity of hazard to the directivity effect calculated using the simplified model, the PPRP finds that this weighting lacks sufficient technical justification. 4 SSHAC Technical Review NUREG-2117 describes the PPRP's technical review role as follows: "The PPRP fulfills two parallel roles, the first being technical review. This means that the PPRP is charged with ensuring that the full range of data, models, and methods have been duly considered in the assessment and also that all technical decisions are adequately justified and documented. The responsibility of the PPRP is to provide clear and timely feedback to the Tl/TFI and project manager to ensure that any technical or process deficiencies are identified at the earliest possible stage so that they can be corrected. More commonly, the PPRP provides its perspectives and advice regarding the manner in which ongoing activities can be improved or carried out more effectively. In terms of technical review, a key responsibility of the PPRP is to highlight any data, models or proponents that have not been considered. Beyond completeness, it is not within the remit of the PPRP to judge the weighting of the logic-trees in detail but rather to judge the justification provided for the models included or excluded, and for the weights applied to the logic-tree branches." As summarized in the table above, the PPRP reviewed the Tl Team's evaluations of data, models and methods on multiple occasions, and through various means, including written communications, in-person meetings, teleconferences, and review of the project report. The Panel was given adequate opportunity to question the Tl Team concerning details of their analysis, and provided feedback verbally and in writing. The Tl Team was responsive to the technical input from the Panel. The Tl Team's responses included evaluating additional data sets suggested by the Panel, undertaking additional analyses to address specific Panel technical questions or concerns, and examining and assessing alternative technical approaches suggested by the Panel. The PPRP therefore concludes that it has been afforded an adequate basis for technical assessment of the Tl Team's evaluations and model integration. As noted above in the final paragraph of the SSHAC Process Review section, the evaluation of directivity effects has been inadequate and may constitute a technical limitation of the study. Apart from that reservation, the PPRP finds that the project meets technical expectations for a SSHAC Level 3 study. Conclusion On the basis of its review of the SWUS GMC project, the PPRP finds that the project meets, with respect to both process and technical standards, the expectations for a 5 SSHAC Level 3 study, with the reservation cited above. That reservation pertains specifically to application of the directivity component of the GMC model to the DCPP site. Sincerely, Steven M. Day Chair, PPRP Brian Chiou Member, PPRP Kenneth W. Campbell Member, PPRP * Thomas K. Rockwell Member, PPRP 6 SWUS GMC SSHAC -PPRP INTERACTION Participatory Peer Review Panel (PPRP) Letters PPRP-la) Letter dated September 17, 2012, to Mr. Barneich and Dr. Abrahamson: Draft Comments on the SWUS GMC Project Plan Results of the Participatory Peer Review Panel (PPRP} review of the draft Project Plan (draft dated August 2, 2012} for the Southwestern U.S. Ground Motion Characterization (SWUS GMC) SSHAC Level 3 study. PPRP-lb) Letter dated November 3, 2012, to Dr. Di Alessandro: Requested Clarifications to the SWUS GMC Project Plan Request for clarifications by the Participatory Peer Review Panel (PPRP) relating to the updated version of the draft Project Plan (draft dated October 3, 2012} for the Southwestern U.S. Ground Motion Characterization (SWUS GMC) SSHAC Level 3 study. PPRP-lc) Letter dated November 29, 2012, to Dr. Di Alessandro: Participatory Peer Review Panel Review of the SWUS GMC Project Plan Results of the Participatory Peer Review Panel (PPRP) review of the consolidated Project Plan (dated November 12, 2012) for the Southwestern U.S. Ground Motion Characterization (SWUS GMC} SSHAC Level 3 study. PPRP-2) Letter dated April 21, 2013, to Dr. Di Alessandro: Participatory Peer Review Panel Comments on Workshop No. l Participatory Peer Review Panel (PPRP) comments on the SWUS GMC SSHAC Level 3 Workshop #1 (Significant Issues and Available Data). PPRP-3) Letter dated December 3, 2013, to Dr. Di Alessandro: Participatory Peer Review Panel Comments on Workshop No. 2 Participatory Peer Review Panel (PPRP) comments on the SWUS GMC SSHAC Level 3 Workshop #2 (Proponent Models and Alternative Interpretations). PPRP-4) Letter dated April 21, 2014, to Dr. Di Alessandro: Participatory Peer Review Panel Comments on Workshop No. 3 Participatory Peer Review Panel (PPRP) comments on the SWUS GMC SSHAC Level 3 Workshop #3 (Pre I imi nary G MC Models and Haza rd Feed back}. Page 1of4 SWUS GMC SSHAC -PPRP INTERACTION PP RP-Sa) Letter dated December 13, 2014, to Dr. Di Alessandro: Participatory Peer Review Panel Letter No. 1: Rev.O Report, Southwest United States Ground Motion Characterization Level 3 SSHAC Project Participatory Peer Review Panel (PPRP} comments and recommendations on the SWUS Project Report, Rev.a (Chapters 7, 10, 11, 12, and 13, and Appendices L, M, N, and R). PPRP-Sb) Letter dated January 5, 2015, to Dr. Di Alessandro: Participatory Peer Review Panel Letter No. 2: Rev.O Report, Southwest United States Ground Motion Characterization Level 3 SSHAC Project Participatory Peer Review Panel (PPRP) comments and recommendations on the SWUS Project Report, Rev.a (Chapters 6, 8, 9, and 14, and Appendices H, I, J, K, O, and Q). PPRP-Sc) Email dated February 9, 2015, to Dr. Abrahamson and Dr. Di Alessandro: Preliminary PPRP comments on Draft Rev.1 SWUS GMC Report (PPRP Informal Communication) Informal transmittal of unedited preliminary comments from Dr. Day and Dr. Rockwell. Attachment PPR P-5 b-A: Preliminary comments from Dr. Day. Attachment PPRP-Sb*B: Preliminary comments from Dr. Rockwell. Attachment PPRP-Sb-C: Suggested minor editorial corrections from Dr. Rockwell. PPRP-5d) Letter dated February 20, 2015, to Dr. Di Alessandro: Participatory Peer Review Panel Letter No. 3: Draft Rev.1 Report, Southwest United States Ground Motion Characterization Level 3 SSHAC Project Provides Participatory Peer Review Panel (PPRP} consolidated comments and rec om mendatio ns for the SWUS Project Report, Draft Rev.1 (Chapters 1 th rough 16}. PPRP*6) Letter dated February 24, 2015, to Dr. Di Alessandro: Participatory Peer Review Panel Closure Letter, Southwest United States Ground Motion Characterization Level 3 SSHAC Project Participatory Peer Review Panel (PPRP) Closure Letter regarding the SWUS GMC SSHAC Level 3 Report, Rev. 1. PPRP*7) Email dated March 9, 2015, to Dr. Di Alessandro: Non-mandatory PPRP comments on Draft Rev. 2 SWUS GMC Report (PPRP Informal Communication) Informal transmittal of non-mandatory comments from Dr. Chiou. Attachment PPRP-7: Non-mandatory comments from Dr. Chiou. PPRP-8) Letter dated March 10, 2015, to Dr. Di Alessandro: Participatory Peer Review Panel Closure Letter, Southwest United States Ground Motion Characterization Level 3 SSHAC Project Participatory Peer Review Panel (PPRP} Closure Letter regarding the SWUS GMC SSHAC Level 3 Report, Rev. 2. Page 2 of 4 SWUS GMC SSHAC -PPRP INTERACTION Technical Integration (Tl) Team and Project Manager (PM) Response to PPRP Letters Tl_Team_PM-1) Email dated November 13, 2012, to Dr. Day: Tl Team and PM responses to PPRP request for clarification on Draft Project Plan, dated November 3, 2012 Participatory Peer Review Panel (PPRP} questions provided with their November 3, 2012 letter. Replies are provided as digital sticky notes superimposed on the PPRP November 3, 2012 letter. Attachment Tl Team PM-1: Responses to PPRP request for clarification. Tl_Team_PM-2) letter dated May S, 2013, to Dr. Day: Tl Team and PM responses to Participatory Peer Review Panel Comments on Workshop No. 1, dated April 21, 2013 Provides the Tl Team and Project Manager's responses to the Participatory Peer Review Panel (PPRP} comments on the SWUS GMC SSHAC Level 3 Workshop #1 (Significant Issues and Available Data). Tl_Team_PM-3) Letter dated January 6, 2014, to Dr. Day: Tl Team and PM responses to Participatory Peer Review Panel Comments on Workshop No. 2, dated December 3, 2013 Provides the Tl Team and Project Manager's responses to the Participatory Peer Review Panel (PPRP} comments on the SWUS GMC SSHAC Level 3 Workshop #2 (Proponent Models and Alternative Interpretations). Tl_Team_PM-4) letter dated May 23, 2014, to Dr. Day: Tl Team and PM responses to Participatory Peer Review Panel Comments on Workshop No. 3, dated April 21, 2014 Provides the Tl Team and Project Manager's responses to the Participatory Peer Review Panel (PPRP} comments on the SWUS GMC SSHAC Level 3 Workshop #3 (Preliminary GMC Models and Hazard Feedback). Other Technical Integration (Tl) Team and Project Manager (PM) Relevant Documentation in Response to PPRP Comments Other-1) Email dated July 28, 2014, to Dr. Day, Dr. Campbell, Dr. Chiou, and Dr. Rockwell: Follow up after the PPRP Briefing Meeting, occurring on July 17-18, 1014 Exhorts further comments by the PPRP after the Briefing Meeting held on July 17-18, 2015 at UC Berkeley, in addition to what was collected in the Meeting Notes. Attachment Other-1: Summary of discussions and PPRP verbal feedback obtained during the July 17-18, 2015 Briefing Meeting. Page 3 of 4 SWUS GMC SSHAC -PPRP INTERACTION Other-2) Letter dated February 23, 2015, to Dr. Day: Replies to Tier 1 and Tier Z comments contained in the Participatory Peer Review Panel Letter No. 3, dated February ZO, 2015 Responses to the Tier 1 comments transmitted via PPRP Letter No. 3. Provides excerpts of the Rev.1 report showing where the comments were accommodated (via comment dialog boxes). It also provides resolution to Tier 2 comments, including summary of the changes applied to the Rev. 1 report (where applicable}. Other-3) Email dated March 9, 2015, to Dr. Day, Dr. Campbell, Dr. Chiou, and Dr. Rockwell: Evaluation of Alternative Directivity Models for DCPP Attachment Other-3: Stand-alone write-up provided by Dr. Abrahamson on March 9, 2015, addressing the PPR P's request to augment the Tl Team's evaluation of the alternative directivity models for application to DCPP. Other-4) Internal project records: Consolidated Comment-Resolution log in response to Participatory Peer Review Panel Letters No. l, Z and 3. Attachment Other-4-A: Consolidated Comment-Resolution log in response to Participatory Peer Review Panel Letter No. 1. The modifications in the text were incorporated in the SWUS GMC Rev.1 and Rev.2 reports, unless diversely stated. Attachment Other-4-B: Consolidated Comment-Resolution log in response to Participatory Peer Review Panel Letter No. 2. The modifications in the text were incorporated in the SWUS GMC Rev.1 and Rev.2 reports, unless diversely stated. Attachment Other-4-C: Con so I idated Comment-Resolution log in response to m a ndato ry ed itoria I comments from Tom Rockwel I dated February 9, 2015. Attachment Other-4-0: Consolidated Comment-Resolution log in response to Participatory Peer Review Panel Letter No. 3. The modifications in the text were incorporated in the SWUS GMC Rev.1 and Rev.2 reports, unless diversely stated. Page 4 of 4 From: Carola DiAlessandro Sent: Tuesday, November 13, 2012 2:47 PM To: Steve Day Cc: John Barneich; norman abrahamson

Subject:

Responses to PPRP Comments and resulting Rev2 Project Plan

Dear Steve,

We have gone over the PPRP comments (PPRP Project Plan Letter dated 11/3/2012) and have accommodated or responded to them as appropriate. We are attaching two versions for Rev2 of the Project Plan. One includes tracked changes and comments referring to which question or minor editorial note is accommodated through the revision. Another document is a clean version of the same Project Plan without comments and change tracking. We are also attaching a copy of your letter with sticky notes indicating a cross reference as to what page each of your comments is accommodated by the plan modifications (Rev 2 Plan attached); such sticky notes address as well PPRP questions or comments in those cases where a change to the plan did not occur. We hope that our modified Project Plan and enclosed responses will satisfy the PPRP panel. Should that be the case, we would appreciate receiving a reviewed letter as appropriate. Thanks, --Carola, John and Norm Carola Di Alessandro, Ph.D. Project Managerfor the SWUS GMC SSHAC GeoPentech, Inc. 525 N. Cabrillo Park Drive, Suite 280 Santa Ana. CA 9270 I Mobile: 510-491-6713 Fax: 714-796-9191 Office Phone: 714-796-9100 Email: carola dialessandro(t1)geopentech.com May 5, 2013 Sleven M. Day Chair, Participatory Peer Review Panel Department of Geological Sciences San Diego State University 5500 Campanile Drive San Diego, California 92182

Dear Prof Day:

The Tl Team and PM appreciate the valuable comments and suggestions received from the Participatory Peer Review Panel (PPRP), both during the Workshop No. I execution and in Lheir fonnal letter commentary daled April 21, 2013. The present document serves to provide written responses to specific comments, suggestions, or recommendations that the PPRP identified (by underlining). 1. Site Kappa and Single-Station Sigma Terminology Several resource experls presenled very interesting and insighlful information on Lhe data needed to estimale the site attenuation parameler kappa and the ground motion standard deviation parameter single-site sigma. However, this material is quite technical and some of it is quite new. Not all participants and observers seemed to have a shared understanding of the terminologies being employed or how the estimated quantities can be applied in a self-consistent manner at each of the nuclear power plant sites where they will be used. Our concern comes partly from the lack of probing questions of the kappa and single-site sigma resource experts from the Tl Team, partly from a lack of significant questions from the audience, and partly from questions expressed by members of the PPRP. Therefore. the PPRP suggests that the Tl Team write White Papers. i.e .. authoritative technical notes. on site kappa and single-station sigma. respectively, that define the tenns. indicate how they are going to be estimated. and how they are to be used in the seismic hazard analysis of each of the NPPs. These documents would provide a common language and reference frame for future discussions and help allay concerns about possible double counting or other inconsislencies in these two paramelers. We agree. Our plan is to coordinate the preparation of the requested White Papers with the effort already initiated by Dr. Linda Al-Atik (a member of the Tl Team Support group) for the Hanford site SSHAC project In this way, in addition to providing a common understanding of the issues and terminology for the SWUS GMC project, we will address consistency with the other ongoing SSllAC projects conducted in the Western US region.

2. Splay Faull Modeling The workshop included some discussion of dynamic rupture modeling of splay faulting, especially models leading to possible concurrent rupture of the Hosgri and Shoreline faults. Our understanding is that SCEC has been tasked with pcrfom1ing such modeling. We arc concerned that this effort may not be as well interfaced with the relevant SSllAC projects (the DCPP and SONGS SSC studies and the SWUS GMC study) as it could be. In particular, the occurrence and extent of concurrent rupture on a splay depends quite strongly on the orientation of the maximum principal stress direction. It is likely also to be sensitive to rupture velocity. The SCEC team tasked for this work has been principally focused on canonical test problems for the purpose of code verification; it should not simply be assumed that the SCEC group has sufficient expertise and experience in the specific rupture dynamics questions being posed by the SSHAC projects to operate independently. The presentation at the workshop did not suggest that the SCEC team recognizes the importance of the principal stress orientations, nor the importance of exploring conditions conducive to a range of rupture velocities. W c recommend that the SWUS GMC project and the other relevant SSHAC projects devise a plan to provide ongoing guidance and feedback to the SCEC modeling team. We note that SCEC has not been tasked with conducting dynamic rupture calculation for splay faulting for SWUS GMC. The activities at SCEC have focused only on code verification (i.e. to make sure codes arc working as intended) for splay fault geometrics that arc relevant to DCPP and SONGS. Based on the results of the verification, we will identify potential groups for conducting dynamic rupture simulations for SWUS GMC Project. However, the decision on the extent of use of dynamic rupture simulations has not yet been made. Our plan is for the TI Team (in particular Prof. Doug Dreger) to work in close contact with the SCEC dynamic rupture verification coordinator (Dr. Ruth Harris of USGS) to understand the role played by stress orientation and rupture velocity in the validation exercise. In addition, we will recommend that representatives from the SSC Teams meet with Ruth Harris to discuss the use of dynamic ruptures for constraining characteristics and frequencies of splay fault ruptures. This infonnation can be used to constrain the source characterization for splay faulting. 3. DCPP-SSC inte1:face issue: Slab Earthquakes During the workshop, the possibility of earthquakes within a relic subducted slab beneath DCPP was broached during the presentation overviewing the DCPP SSC project. To our knowledge, this possibility of slab sources had not been mentioned at previous DCPP SSC workshops, and from the discussion at the workshop, it was not clear which project takes responsibility for assessing its technical defensibility and implications. Slab earthquakes are known to excite ground motion with systematically distinct characteristics relative to crustal sources. We recommend that the two projects clarify the lines of responsibility and establish effective communication on this subject so that the TI Team is not taken by surprise if slab events are characterized in the DCPP SSC. We agree and will engage the DCPP SSC Project Team to address the potential for slab earthquakes in the DCPP region. The final decision for inclusion or exclusion of slab earthquakes lies with the SCC Team but information from ground motion experts that maybe relevant to the SSC Team evaluation will be provided by the SWUS GMC project. 4. DCPP-SSC and SONGS-SSC inte1.face issue: Maximum depth of rupture in crustal earthquakes During the DCPP SSC overview presented at the workshop, the possibility was raised of deep cmstal earthquakes, i.e., greater than 15-20 km deep, on some cmstal faults in California. The SWUS GMC TI Team seemed unaware that this was a possibility in the DCPP SSC project and it was not clear to us which project takes responsibility for the technical assessment of deep cmstal earthquake modeling. We recommend that the two projects clarify ownership of the depth-ot:. faulting problem and begin to communicate effectively and regularly about the status and implications of those ideas. We agree. Information on the maximum depth of mpture may be available from source inversions commonly used in ground motion studies that arc not yet being considered by the DCPP and SONGS SSC TI Teams. Ensuring that this interface issue is addressed is the responsibility of the Project Technical Integrators (PTls) for the SSC and GMC efforts for each site. We will provide examples of ground motion inversion studies to demonstrate the range of depth-of-ruptures implied by these studies so that the SSC TI Teams arc fully informed. The final decision for the distribution of rupture depths lies with the individual SSC Teams. 5. Attenuation for Palo Verde The attenuation of ground motion between distant earthquakes and PVNPS may be quite strongly dependent upon the source location and might not be well represented by a single function of distance. The TI Team clearly recognizes this likelihood and has taken it into consideration in their plan to empirically estimate attenuation from distant sources to PVNPS using existing recordings from relevant source regions. We consider this a sound approach. However, the PPRP would suggest that the empirical approach be carefully applied in the light of a geological understanding of both the source and path regions (for example, it might be observed that paths crossing the Salton Trough are highly attenuative and geologic understanding might dictate that the same empirical correction not be applied to nearby sources that do not cross thal province). We agree. The SWUS GMC TI Team will consider different regions (one being the Salton Trough region) when evaluating the residuals to derive empirical correction factors applicable to PYNGS. In order to preserve the statistical robustness of the analysis, we are expanding our ground motion dataset so to include more earthquakes generaled in central California (up to 400 km from the Arizona border) and recorded by stations in Arizona located up to I 00 km away from PYNGS, but still within the Sonoran Basin and Range zone as prescribed/mapped by the associated SSC effort. These additional earthquakes will allow us to evaluate Lhe need for diflerent path effecls through the Salton Trough versus other path effects. 6. Hand-r?[f to Site-Spec(fic Site-Response Analysis Team The GMC Tl Team is proposing to characterize ground motions for a common reference rock condition with Ys30 = 760 mis and to adjust the base case GMC model to incorporate utility-specific differences in site characteristics and modeling approach. We understand that each utility will adjust the resulting rock hazards to the local site condition at each NPP site when deriving the Consistent Ground Motion Response Spectra (GMRS). The TI Team have acknowledged need for interaction between these two efforts and emphasized the importance of proper handoff of the GMC model to the team responsible for specific site-response analysis. Slill we want to further emphasize it here by cautioning that lack of clarity and precision in the communication between the GMC TI Team and the site response analysis team may make both vulnerable to misunderstandings and claims of inconsistency or double counting of effects. We recommend that the TI Team and the individual site projects collaborate to generate as soon as possible a reference document that describes the respective adjustments and procedures to be used at each site and that explains the technical rationale in each case. As with the documents on kappa and single-site sigma recommended in Item I above, such a document would serve to guide future discussions, prevent misunderstandings, and ensure that no relevant data or models arc neglected due to uncertainties about which project is responsible. We agree. Although site response is not part of the deliverable for SWUS GMC, the approaches being used for site response at the three NPP sites need to be underslood and clearly documented to ensure a consistent interface between the base case ground motion and site response. The final decision on site response approaches lies with the individual NPP siles.

We plan on issuing a White Paper describing the site-response approaches being used at each of the Lhree sites; this document will include the Lechnical base for the seleclion of the reference rock conditions. We hope this letter clarifies the queslions and comments stated in the April 21, 2013 PPRP Commentary Letter. We wish to express our gratitude to the PPRP again for their efforts and cooperation, and for making this project a success. Sincerely, .. . ,..., l:;j_? . _j ** ,

• 0 . .cc0-.,*(...o Carola Di Alessandro, SWUS GMC Project Manager CC: PPRP Panel, TI Team, PTis Norman A. Abrahamson, SWUS GMC Tl Team Lead January 6, 2014 Steven M. Day Chair, Participatory Peer Review Panel Department of Geological Sciences San Diego State University 5500 Campanile Drive San Diego, California 92182

Dear Prof. Day:

The Tl Team and PM appreciate the valuable comments and suggestions received from the Participatory Peer Review Panel (PPRP}, both during the Workshop No. 2 execution and in their formal letter commentary dated December 3, 2013. The present document serves to provide written responses to specific comments, suggestions, or recommendations that the PPRP identified (by underlining). 1. Balanced participation by the Tl team members. During the first two days of the workshop, a disproportionate amount of the interrogation of the proponent experts was done by the Tl lead, with some contributions from other senior members of the team. Other members were not significantly engaged in the discussions on those days. This imbalance is a concern, because SSHAC guidelines for a Level 3 study explicitly call for Tl team members to be prepared to voice independent views and technical challenges. The PPRP was pleased to see more balanced participation on the third day and recommends that the Tl team take concrete steps to ensure that this progress continues during the remainder of the project. The importance of full Tl team participation is emphasized in the NRC SSHAC guidance document (NUREG-2117), which states, for example (p. 36) "membership in the Tl team automatically implies sharing the ownership of the component models developed by that team" and (p. 38}, while discussing the distinction of a Level 3 SSHAC study in contrast to lower level SSHAC studies, "The Tl must now be a team rather than an individual or small group, ... at Level 3, this is essential both because no individual has the breadth of expertise required and because of the necessity for technical challenge and defence among the evaluators." REPLY: We agree with the PPRP about the need of a full Tl Team participation. The Tl Lead will take responsibility to ensure that all members of the Tl Team participate fully and, if necessary, actively asking each Tl Team member to make comments or ask questions during the Workshops. 2. Selection criteria and decision date for GMPEs. Some of the ground motion prediction equations (GMPEs) presented and discussed at the workshop appeared to the PPRP to be at a less mature stage of development than the others. For example, one has not yet been fully described and documented in a formal publication. We recommend that the Tl team formulate and document, as soon as possible, clear criteria to be employed to determine which GMPEs will be used in hazard model development, and that documentation of the acceptance criteria Reply to PPRP Commentary Letter on SWUS Workshop #2 -Jan. 6th 2014 Page 1 include a justification, and that it specify a firm cutoff date for achievement of the criteria, based on a realistic assessment of schedule requirements. The selection criteria should be applied on a consistent basis to all candidate GMPEs. REPLY: Agree. We are currently planning on accepting GMPEs finalized (stable) and adequately documented by the end of 2013. GMPEs selection criteria will be clearly documented in the final project report, together with evaluation on applicability of the models for the project. 3. Completeness of proponent-model analysis in Workshop #2. The project team made a thorough effort to identify, select, and invite proponents of alternative interpretations. Not all invited proponents were able to attend the workshop. In the absence of a proponent to support the GMPE and magnitude-scaling recommendations of Dr. Zhao and his colleagues, their viewpoints on magnitude scaling of ground motion were solicited and presented by the Tl Team; therefore an opportunity existed at the workshop to discuss and challenge them. This approach was fully consistent with guidance in the NRC SSHAC guidance document (NUREG-2117) ( p. 70), which states, for example: "Because not all proponents of alternative viewpoints may be able to attend the workshop, interpretations made by individuals who may not be present should be identified and discussed." On the other hand, Dr. Idriss (author of the Idriss NGA-West2 GMPE} and Drs. Atkinson and Assatourians (developers of the finite-fault stochastic simulation method, EXSIM) also were absent, yet no representatives were designated to represent their models. As a result, discussion and debate of the merits of these two models were largely incomplete. The PPRP recommends that the Tl team make an additional effort to complete the evaluation of these two proponent models at a level equal to that of the other models being evaluated. It should take place before the development of preliminary hazard models, and in a setting consistent with NUREG 2117, which stipulates (p. 39} that in a Level 3 study, the interactions with proponent experts should be "conducted openly in the presence of observers including the PPRP." REPLY: Agree. We plan on evaluating the two aforementioned proponent models during a special working meeting (January 28 and 29, 2014) in the presence of PPRP, while also inviting relevant Proponent Experts and Resource Experts who attended the Workshop #2. Back up plans have also been discussed to make sure the Tl Team has a chance to discuss the proponent model with the experts if the authors cannot attend the meeting. These discussions will be summarized at the special working meeting. 4. Completion of Workshop #2 objectives. The PPRP noted that there were many ongoing tasks that could not be evaluated in Workshop #2 because they were either incomplete or had just begun. The Tl lead pointed out during the workshop that these tasks will need to be fully discussed and evaluated in order for the Tl team to obtain feedback from the resource and proponent experts to factor into their evaluation. The PPRP agrees that there is the need for an additional meeting with resource and proponent experts, including the PPRP as observers, to cover these ongoing and incomplete tasks. The PPRP emphasizes, moreover, that sufficient time should be allowed between such a meeting and Workshop #3 to enable the Tl Team to fully evaluate and discuss the feedback from the meeting and incorporate that feedback into the preliminary ground motion logic tree and the related sensitivity studies that will be presented and discussed in Workshop #3. This concept is embodied in the NRC SSHAC guidance document (NUREG-2117) that states (p. 67) "Any new data collection activities should be identified early in the project, evaluated for their potential impact on the hazard results and associated Reply to PPRP Commentary Letter on SWUS Workshop #2 -Jan. 6th 2014 Page2 uncertainties, and completed in a timely manner for use in the technical evaluations. Typically, this would mean that the activities should be completed prior to Workshop #3 on Feedback and certainly no later than the time that the models are finalized; (p. 68) Each workshop has a specific focus and goal, and each requires that particular work activities have been conducted prior to its occurrence and certain work activities will occur following;" and (p. 73) "Following Workshop #2 and prior to Workshop #3 Feedback, multiple working meetings will be necessary to develop a preliminary model that can be used for purposes of sensitivity analyses to provide the necessary feedback to the Tl Team." Tl Team should consider scheduling this additional meeting such that there is sufficient time between it and Workshop #3 to prepare and revise the preliminary ground motion logic tree and to perform related sensitivity studies. REPLY: Agree. The special working meeting planned at the end of January 2014. This provides adequate time for the Tl Team to incorporate the information from the working meeting into the initial GM model to e presented at Workshop #3 5. Schedule and prioritization. Over the course of the workshop, numerous technical issues that are currently under investigation were identified as requiring substantial further work before certain modeling procedures can be included in a hazard model. The PPRP is very pleased that the project has initiated important investigations that are likely to have a big impact over the longer term, and the fact that some will not reach full practical implementation during this project is understandable and inevitable in an effort such as this one. As the Tl lead noted, in the short term, incomplete resolution of these technical issues can be accommodated in the hazard model through appropriate expansion of epistemic uncertainty estimates. The PPRP urges, however. that the Tl team reach a prompt decision on which efforts to prioritize for inclusion in the hazard model. That decision should consider hazard sensitivities, and should be made early enough to realistically account for project schedule requirements. For example, by Workshop #3, which is scheduled for March 2014, a preliminary hazard model should have sufficient maturity that the PPRP and others can meaningfully probe its technical basis and understand the manner in which it incorporates the views of the larger technical community. We also note that a preliminary report is due for PPRP review within just a couple of months following Workshop #3. REPLY: Agree. We are using hazard sensitivity to identify the critical technical issues. Sincerely, Carola Di Alessandro, SWUS GMC Project Manager CC: PPRP Panel, Tl Team, PTls Norman A. Abrahamson, SWUS GMC Tl Team Lead Reply to PPRP Commentary Letter on SWUS Workshop #2 -Jan. 6th 2014 Page 3 May 23, 2014 Steven M. Day Chair, Participatory Peer Review Panel Department of Geological Sciences San Diego State University 5500 Campanile Drive San Diego, California 92182

Dear Prof. Day:

The Tl Team and PM appreciate the valuable comments and suggestions received from the Participatory Peer Review Panel (PPRP), both during the Workshop No. 3 execution and in their formal letter commentary dated April 21, 2014. The present document serves to provide written responses to specific comments, suggestions, or recommendations that the PPRP identified (by underlining). 1. Documentation. As noted in the summary comments, the ground motion model contains a number of advanced elements aimed at providing improved confidence that the CBR of the TOI is being captured. The scientific development and validation of these advanced elements has been driven in large part by this project. The technical bases for these elements appear to be sound, and they represent significant advances in hazard assessment. However, because they are technically advanced and relatively complex, they will have to be carefully and fully documented in the project report. Careful and clear documentation of complex procedures and concepts (for example, the construction of a multidimensional GMPE space, its visualization via Sammon mapping, and its final characterization from representative points on that map, in light of disparate data sets and simulation results) may be critical to project success. The PPRP recommends that Tl team members pay close attention to the documentation of these advanced model elements to ensure that the final report is not only complete and scientifically sound. but also as transparent and persuasive as possible to the PPRP and a broader technical audience. ?EP:Y: We agree Lhe 81 ::.he nat*;, 1". ciraft j:::ur:-1al paper*,.,, .. be :::::::T1p.eted r*:-.e ,.:;-u*y Griefing 2. Site effects interface issue. During the workshop, it became clear that the project had not yet produced a comprehensive reference document describing the adjustments and procedures to be used to modify the reference ground motions for use at each site (i.e., at PVNGS and DCPP). The PPRP previously recommended that such a document be developed in a letter to the Project Manager dated April 21. 2013 (Recommendation #6) following Workshop #1. and this recommendation is repeated here. As noted previously, any lack of clarity and precision in the communication between the Tl team and a site response analysis team may make both vulnerable to misunderstandings and claims of inconsistency or double counting of effects. A comprehensive 1 written document would serve to guide discussions, prevent misunderstandings, and ensure that no relevant data or models are neglected due to confusion about which project is responsible for which elements of the ground motion model. ?RP:.Y: We agree. A will be co:rpleted si:-e respcnse *,rnrY.: it; !>ti\r:-.ed. 3. SSC interface issue. The workshop revealed some apparent gaps in coordination between the Tl team and the respective SSC Tl teams for the DCPP and PVNGS SSHAC Level 3 projects. For example, the Tl team appeared to be unaware of the inclusion of strike-slip sources in the source component of the SSC model for PVNGS, and only presented GMC models relevant to normal faulting. As a second example, the Tl team discussed the PVNGS local-source component in terms of random fault orientations, whereas the PVNGS SSC Tl team will provide preferred orientations in the final SSC model. A further concern is that the DCPP SSC model might include a large range of rakes on dipping faults, and some coordination between that project and the GMC project may be required to ensure that those sources are appropriately categorized for use in the GMC model (e.g., the treatment of oblique slip sources was not discussed by the Tl team). The PPRP recommends that the Tl team improve coordination with the Tl teams of each of the SSC projects to ensure that the GMC approach is fully compatible with the respective SSC approaches, so that last-minute issues will not arise that could delay project completion. ?fo.P: Y: ;.".ie a.qree. ': .. !e :-::.-.ve a -:-e:.:i::Jv i :rp:-cveci :-.'.-:e : :r:e:-:.ict o:-: with :-.:-:e for :i::d PVt\C:-;. 'i*!e :;ee ilr:y tiona.:_ al Lhls L.:_nc. 4. Feedback on a complete preliminary model. The workshop provided a very good exposition of the conceptual framework of the ground motion logic trees to be employed, as well as their technical bases. In most cases, the specific branches were identified, and there was extensive technical questioning and discussion from the PPRP and other experts, meeting most of the workshop objectives. Nonetheless, the model feedback process was not quite completed at Workshop #3, because a complete preliminary model populated with weights was not available to be interrogated by the PPRP at that time. As noted in NUREG 2117 (p. 71), "In the discussions of the preliminary models, the technical bases for the assessments and weights should be described to allow for a discussion of the implications and constraints provided by the available data." The PPRP supports the Tl team's preliminary decision to hold one or more briefing meetings to present a full preliminary model to the PPRP for feedback when it becomes available, in advance of their development of the final model. 'f'!e *:_,,;: :1d:Lt.io:::1.:_ ::i\Ve beer: *,::_th the :::*PRF: :..he ..'..l.:-sl 0:1c on Eay -_t;, l_hc scco:1c:. cr:c Ju-_y 17--_8, 5. Geologic consistency of models for ground motion simulation. The numerical simulation of specific sources at DCPP employed fault geometrical parameters (in particular, down-dip fault widths) that are not consistent with the SSC model. The PPRP recognizes that this may be largely an artifact of the way the numerical models are parameterized, together with the understandable project requirement to hold that parameterization fixed in the form it had when the numerical models were calibrated and validated. The PPRP also recognizes that the principal application of the simulations to date has been to test methods for combining empirical relationships so as to approximate special conditions not represented well in the database, such 2 as the simultaneous rupture on a main fault and a secondary splay. In that type of application, the PPRP agrees that the results may be insensitive to the precise simulation geometry relative to the SSC model. However, the appearance of discordance between the simulation parameters and actual fault parameters developed by the DCPP SSC is a potential source of confusion. The PPRP recommends that project documentation give careful attention to any apparent inconsistency between the ground motion simulation parameters and the actual fault parameters developed by the DCPP SSC team. Where simulations are used only to test methods for applying empirical methods to special situations, the Tl team might evaluate whether to simply treat the simulated faults as representatives of generic fault types, rather than associating them with specific faults from the SSC model. On the other hand, if simulated ground motions are employed more directly, it will be necessary to document with care their actual relationship to the SSC model. 'i*!e :...he Broad 3an..:;. L .. a:...lo.rr.1 exn the : 'n'::a::icn t::P. lin:_ :-.a::i :r:!> ::::P. c<.,p:ibil:_ tie<; o.: (B::H'J .i.n Lcrr.1::; ol .s::;urcc c:ha.:-ac1 .. cr.i..sL.i.c::;, a:1c:. cf the ::a the SSC 6. Representation of CBR of hypocenter locations. In the development of the model of additional standard deviation to account for rupture directivity, the Tl team assumed a model of hypocenter locations in which strike-slip earthquake epicenters had a tendency to concentrate near the center of the rupture trace. The team cited empirical results of Mai and others in support of this assumption. However, other relevant data are available (e.g., global compilations such as that of McGuire et al. in BSSA, 2002, as well as data from detailed studies of individual earthquakes in California and elsewhere). If the form of the hypocenter distribution is significant to the conclusions of the directivity study, the PPRP recommends that the Tl team further evaluate the hypocenter distribution model to ensure adoption of a final version that adequately captures the CBR of the TOI. ?Rr-v: agree. for ::he eva. * .. w:-.ed. 7. Frequency shift of between-event standard deviation. The Tl team showed at the workshop that, if not removed by smoothing (as was done by some NGA-West2 developers), the event standard deviation tau has a so-called "bump" at short periods that is not as visible in the within-earthquake standard deviation phi. The Tl team showed evidence from a simple stochastic analysis that this bump is likely due to systematic variability in site effects, presumably due to variability in kappa, that is being transferred to tau and should, therefore, be included as part of the within-earthquake variability. Based on this conclusion, the Tl team has adopted as part of their logic tree a smoothed short-period tau model with no bump and instead is transferring this aleatory variability to the site-response model. One of the interesting features of the bump in tau, which is often described as being at 0.1 sec (10 Hz), is that it occurs at a shorter period for small earthquakes than for large earthquakes and has a pronounced dip near 0.3-0.5 sec, which also changes with magnitude. The PPRP recommends that the Tl team seek an explanation of the apparent frequency shift of the bump and dip in tau with magnitude and assess whether it is consistent with the proposed hypothesis that these effects represent variability in site effects rather than source effects. p::-,:-,r.v: The apparent o-:' the t* .. ::r::-; anci ciip ::.at: "':'::h is a. 2f the of :egio:-:s for :i::d L1 rqe 1:1<H.:pi 'i*!e * .. ev:1l 1:iltP. th:_;; :_;;;;-.:e by :_nq the 3 ta*_: f:::r sr1a--larqe f:--:::T1 a :--eg'o:-1 as see if the is no cbserved as 8. Epistemic uncertainty in median prediction. The epistemic uncertainty in predicted median ground motion includes two components -the within-GMPE uncertainty of estimated GMPE coefficients and the between-GMPE variability. At the workshop, the Tl team's proposed approach for evaluating the latter component of uncertainty (via the construction of GMPE space) received substantial discussion and helpful feedback. There was, however, not as much discussion of the within-GMPE uncertainty. Since uncertainty in median motion is an important contributor to the uncertainty in calculated hazard, the PPRP recommends that both GMPE and within-GMPE components of epistemic uncertainty be evaluated with comparable rigor and that each be represented in the logic tree with an appropriate level of detail. K: .. :::' L:: A!> !> ho,:;:1 i:1 :-.::e .J <HF Ji.\ r*; 2 Cl 11 Y.: :.-:1q i nq by X . ::.:*.1e:: r:, the *,.;i *; 'l!> by A.:_ -.r-.:::.-Y.: a:1d :ou:1q<; pc.;::..c<, n.:;r)or:-. 0:1 cp.i.s:..cn.:_c: u:1c:e::::La.:_n:_y .i::; 1r....;ch :::;ria.:_.:_c::: L:*:c :oc:..*:.:e:e:r:-r.1oc:.c.:_ epi.ster1'::: ar:::I is bei:-1g ::::aptureci *:::y :::vera--rar:.:;*e 'n the node:s develcced. We we be able to thi<; to be ::::2 c<Lie :-.he fine.\.:_ :r.:::d2.:_ a:1d, thP.ref:::::::2, 0:1 :::* .. ::::: o.:_ unccr:..a.ir:Ly :..8 dcvc.:_8p Lhc o.:_ X8dc:s. We hope this letter clarifies the questions and comments stated in the April 21, 2014 PPRP Commentary Letter. We wish to express our gratitude to the PPRP again for their insightful questions, and for their continuous review of this project. Sincerely, / -.. Norman A. Abrahamson, Carola Di Alessandro, SWUS GMC Tl Team Lead SWUS GMC Project Manager CC: PPRP Panel, Tl Team, PTls 4 The following documents may be grouped as follows: I. Source Characterization PPRP A) Completed PPRP Comment Response Log PPRP Comment-Response Log_Appendix C_2015_03_04.pdf "5-; PPRP Comment-Respome Log_Appendix 0_2015_02_27.pdf PPRP Comment-Response Log_Appendix E_2015_02_27.pdf PPRP Comment-Response Log_Appendix F _2015_02_27.pdf PPRP Comment-Re'.;ponse Log_Appe:nclix G_2015_03_05.pdf PPRP Comment-Response Log_Appendix H_2015_02_27.pdf "5-; PPRP Comment-Respome Log_Ch l-4_2015_02_14.pdf "5:: PPRP Comment-Response Log_Ch 5_2015_02_16.pdf PPRP Comment-Response Log_Ch6_2015_02_20.pdf PPRP Comment-Re!:ponse Log_Ch7_2015_02_23.pdf PPRP Comment-Response Log_Ch8_2015_02_27.pdf "5-; PPRP Comment-Respome Log_Ch9_2015_02_20.pdf PPRP Comment-Response Log_Ch10_2015_02_27.pdf PPRP Comment-Response Log_Chlla_2015_02_23.pdf '5-:: PPRP Comment-Re!:ponse Log_Chllb_2015_02_23.pdf PPRP Comment-Response Log_Ch12_2015_02_18.pdf PPRP Comment-Response Log_Chl3_2015_03_04.pdf "5-; PPRP Comment-Respome Log_Ch14_2015_03_03.pdf B) PPRP Draft Report Comments *'

• J I 0:: -,:_ PPRP Comments Installment 1_2014_12_14.pdf -,:_ PPRP Comments Installment 2_2015_01_10.pdf PPRP Comments Installment .3_2015_01_21.pdf PPRP Comments Installment 4_2015_02_12.pdf PPRP Comments Installment 5_2015_02_20.pdf ,_Trans Ltr PPRP Installment 2_2015_01_09.pdf Ltr PPRP Installment 3_2015_01_21.pdf "l:._ Tram Ltr PPRP Installment 4_2015_02_12.pdf Ltr PPRP Comments Installment 5_2015_02_20.pdf C) PPRP Non-Mandatory Comments Non-mandatCr)' Ccmmi:nts 1st Round Re'.-01.pdf PPRP Non-Mandatory Ccmmi:nts_2015_Q2_28.pdf PPRP Non-Mandatory Ccmmi:nts_2015_Q3_Q6.pdf D} PPRP Workshop Letters and Responses -,.__ PPRP _Letter_',*VSl.pdf PPRP _Letter_',*'/S2.pclf -,.:_ PPRP _Letter_'NS3.pclf -,.__ P.esponse_to_PPRP _WS2.pdf -,.:_ Response_to_PPRP _1NS3.pdf II GROUND MOTION CHARACTERIZATION -,..:.. Attachment_ Other-1.p df -,..:. Attachment_ Other-3 .p df Attachment_Other-4-A.pdf Attachment_Other-4-8.pdf Attachment_Other-4-C.pdf Attachment_Other-4-D.pdf Attachment_PPRP-5b-A.pdf Attachment_PPRP-5b-B.pdf .,.., Attachment_PPRP-5b-C.pdf .,.., Attachment_PPRP-7.pdf .,.., Attachment_ ll_ T eam_PM-1.pdf II GROUND MOTION CHARACTERIZATION -,...:: Othe:r-1.pdf -,...:: Othe:r-2.pdf -,...:: Othe:r-3.pdf -,...:: PPRP-la.pdf -,...:: PPP,P-lb.pdf -,...:: PPRP-lc.pdf -,...:: PPRP-2.pdf -,...:: PPP.P-3.pdf -,...:: PP RP-4. p df -,...:: PPRP-5a.pdf -,...:: PPRP-5b.pdf -,...:: PPRP-5c.pdf -,...:: PPP,P-5d.pdf -,...:: PPP.P-6.pdf -,...:: PPRP-7.pdf -,...:: PPP,P-8.pdf PPRP-INTEP...A.CTION_S.\o'iUS._9Apr2015.docx -,...:: PP RP-INT E P...A.CTIO N_SViU 5_9Ap r2015. p df -,...:: TI_Te:am_PM-1.pdf -,...:: TI_Te:am_PM-2.pdf -,...:: TI_Team_PM-3.pdf -,...:: TI_Team_PM-4.pdf Comment Location in Text Number Line 152 Line 154 Line 235 Line 273 Line 307 Line 455 Line 207 Line 224 Line 292 Line 300,301 Line 315 Line 322 Line 545 Line 821 Line 948 Line 44 PPRP Comment Response Table Final Review PPRP Comment CHAPTER4 "This database has been supplemented" -"been" Describe should be past tense Add a comma after "study area", and another after "data set" Add a space between Central and California Add two commas -" ... sand spit and, based on detailed analysis of the relict shoreface, estimate ... ,, Delete *'for the" after **rates" CHAPTERS " ... stepping of the proto-transform fault 5 Ma to the ... " Is there a missing word here? "at 5 Ma"? Insert "at" between beginning and approximately(?) Insert "At" before approximately -"At approximately 12-10 Ma," ** . current location at the San Andreas fault between approximately 5 Ma. Between 5 Ma and when? Or, at approximately 5 Ma? Move the comma to outside of the quotation mark around "benched" This would read more clearly as "Dextral rates of slip ... " "include" should be singular This would read more clearly as The Lompoc earthquake of 1927, estimated at M7, is the largest event recorded ..... "sympathetic" or antithetic?? CHAPTER6 Typo in **seismogenic". Summary of Revisions to Report Table 6-1 In Table 6-1, 199 Hector Mine Earthquake: "The complex northward rupture initiated on an unknown north-trending structure (a splay to a previously mapped but unnamed fault, which is now referred to as the Lavic Lake fault) and propagated north on both branches of the Lavic Lake fault and propagated southward onto the Buillion fault (rupturing both the East and West strands of the Buillion fault." Details of this statement are incorrect. Actually, based on mapping of the surface rupture (Treiman et al., 2002), the rupture propagated bilaterally on the Lavic Lake fault (as the earthquake nucleated in the middle of that fault) and then southwestward onto the Bullion fault. Also, there is only one branch of the Lavic Lake fault north of the epicenter, unless you consider the splay fault a branch. Note the rupture is correctly described in ch 9 (lines 455-460}. CHAPTER7 Line 463 Need a space between " ... (Figure 7-Sb)." and "The alternative ... " Figure 7-18a The caption still has the apparent inconsistency pointed out in Comment 385 (the Response Log says it was "revised as suggested," but that does not appear to be the case). That is, shouldn't the reference to "sinistral ranspression" on the third line actually be "sinistral transtension .. ? There is no phase of **sinistral transpression" represented in the figure, so certainlv somethina is inconsistent. CHAPTERS Line 123 Need a space between ", .. therefore," and "the probability weights ... " Lines 339 & 340 Eolian is spelled 2 different ways -be consistent. Line 385 Delete space before period at end of sentence. CHAPTER9 Comment 551, This discussion is a good step forward, but it is not as explicit as it could as addressed be about how aleatory variability and epistemic uncertainty are in Chapter 9, accommodated, and distinguished, in the rupture-source framework. A Section 9.1. full reading of the report seems to indicate, roughly, that (1) the OV, SW and NE Rupture Models represent different logic-tree branches that (together with branches for the various magnitude pdf models and rupture-source slip rates) collectively sample and represent the range of epistemic uncertainty in the slip budget and the way that slip budget is distributed spatially and with respect to magnitude and style of faulting: and (2) the collection of rupture sources (and their respective magnitude pdfs) within each Rupture Model is designed to capture the corresponding aleatory variability in magnitude (and rupture dimensions). This is probably not quite the right formulation, but certainly some precise statement of this sort that is similarly compact and explicit would be valuable introduction to ouide the reader forward. Comment 566 Comment 566, Chapter 9, noted that the Los Osos-San Luis Bay splay occurs at an acute-angle fault intersection, and is therefore an exception to the stated rule that faults "that intersect at acute angles are not part of the same rupture source." The Tl Team response is that this exception doesn't need to be noted because the intersection is at depth, not at the surface. This is a non-sequitur the stated rule has no stipulation as to whether the acute intersection is in the surface trace or fault plane in general. This is a minor point to be sure, but it remains an inconsistency that leaves the careful reader confused and affects readability, and seems trivial to clear up. 641 The response given by the Tl Team appears to be a paragraph that is intended to be included in the text. Is this the case? Line 428 Correct spelling of Kickapoo CHAPTER11 543-546 Figures 11-11 through 11-15 are not included in the figures provided and the comments made by the Tl Team are unclear with respect to exactly what actions were taken to address the PPRP comments.

COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT PPRP COMMENTS AND Tl TEAM RESPONSES, APPENDIX C (HAZARD INPUT DOCUMENT) Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision APPENDIX C -Final SSC Model Hazard Input Document 869 Line 10 Model-building is restricted to the Tl Team. Suggest changing to "to Line 10 Text revised as suggested. implement" the SSC model. 870 Line 25 Are areal sources and areal source zones the same thing? Suggest Line 26 Text revised to list three areal source zones in the consistent use. model. 871 Line 30 Source-site? Source to site would be clearer. Line 30 Text revised as suggested. 872 Line Rupture sources for Hosgri Table H.2-4 lists 7 sources (all three FGMs): Table C.2-4 Table corrected to show 8 rupture sources. Rupture H-104 however. in Table H.2-6 there are 8 rupture sources for the Hosgri 08 is not on the Hosgri fault zone, but is grouped with Table the Hosgri ruptures to provide an alternative rupture H.2-4 7 source involvina the PB. 873 Line Should 7 ruptures be 8 ruptures? Line 131 Text revised to show 8 rupture sources 130 874 Line Please add the missing parenthesis at the end of the sentence. Line 185 Text revised as suggested. 184 875 Line Why are some "sub" rupture in italics? Line 190 Text revised to eliminate the italicized 'sub' 189 876 Table Standard deviation is zero?? Please clarify (e.g .. would it be more Table C.2-15 Text revised as suggested to use NIA. H.2-15 appropriate to say "n/a", as is done for truncation factor on the next line). Line 244 877 Line Might consider changing figure so it parallels text (a) maximum magnitude Figure C-7 and Figure C-7 and Text in Section C.2.5 reordered for 246 (b) Y-C characteristic (c) exponential (d) WAACY text consistency with Chapter 10 and between figure and Figure text, as suggested. H-7. 878 Line Delete "is" between "term" and "in" for clarity. Line 290 Text revised as suggested. 288 879 Line Why is OV-09 linked and Characteristic -why is it not Category B? Line 304 It is a linked rupture source because its longest length is 299 (LP+FS+FN+ON+OF) not capable of hosting an Mmax that differs meaningfully Table from an alternative Mchar. H.2-22. Please check other tables with linked faults H.2-24, H.2-26 880 Line Table H.6-1 has NE and SW dipping reverse faults; logic tree Figure H-13 FigureC-13 Figure edited to be consistent. Only NE and SW shown. 399 has N or NE and S and SW for the reverse faults -please make consistent. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT PPRP COMMENTS AND Tl TEAM RESPONSES, APPENDIX D Location in Comment Location in Text PPRP Comment Text for Summary of Revisions to Report Number Comment Revision APPENDIX D -Workshop Summaries 881 Line 21 "A GMC model -"A should be lower case Line 21 Text revised as suggested. 882 Line 24 Change are" to '"is" as the verb refers to Each workshop presentation" Line 24 Text revised as suggested. 883 Line 34 Consider spelling out RE at first usage in the appendix. Line 36 Text revised as suggested. 884 Line 53 You should not leave the reader with the impression that the master list Line 55 Text revised as suggested of data collection activities coming from the workshop was. in fact, funded. 885 Line 56 Delete "but." Line 57 Sentence revised for clarity. Conjunction needed for accuracy. 886 Line 56 Insert '"are" after "presentations" for clarity Line 55 Text revised as suggested. 887 Line 101 Typically, the term "hazard" is used to specify the annual frequency of Line 102 Added text after the word '"hazard" to clarify that exceedance (y-axis of the hazard curve). rather than the ground motion hazard is being used here as AFE (x-axis of the hazard curve) for a given AFE. Please clarify if this is the way that '"hazard" is used here and subsequently when talking about percent contribution to the hazard (i.e., is it the AFE or the ground motion at a aiven AFE?) 888 Lines 107 -108 '"none of the more distant faults contributes> 1 % to hazard ... " Is this per Lines 107-112 Text added to clarify that none of the distant fault fault? In which case, because there are a lot of faults, could sum to sources (with the exception of the SAF) significant hazard, or does this mean that these distant faults individually contributed> 1% to total hazard, cumulatively amount to < 1 % of total hazard? Please clarify. though cumulatively (with the SAF), they contributed -5%. In considering fault sources individually, the Hosgri. Los Osos, SLB. and Shoreline are still the most important for hazard. 889 Line 113 Delete 2nd '"that." Line 117 Text revised as suggested. 890 Line 113 The tornado diagrams actually show the sensitivity to hazard uncertainty, Lines 116-122 Text revised to describe tornado diagrams as rather than to hazard itself. Suggest stating that they show the range in depicting sensitivity to hazard uncertainty: "In hazard results for the range in values of an input parameter in the logic addition, Ms. Wooddell examined the ranges in tree. Thus, they show how much uncertainty in a parameter leads to hazard results for the range in values of various uncertainty in the hazard result. If no uncertainty is included for a given input source parameters associated with the four parameter. it shows no contribution to hazard uncertainty. nearby faults, including slip rate. fault dip/geometry, crustal thickness, and fault length (including joint ruptures). The resulting ranges in hazard results, or sensitivity to hazard uncertainty, are presented in "tornado" diagrams that rank the source parameters in order of "most significant" to '"least significant" to hazard uncertaintv at Diablo Canvon. As shown on COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT the tornado diagrams (for PGA. T=0.2 sec. and T=2.0 sec) provided by Ms. Wooddell. the source parameters that are most significant to hazard uncertainty at Diablo Canyon are, in order of significance ... ** 891 Line 114 Delete the extra "that" Line 117 Text revised as suggested. 892 Line 186 Insert "USGS" in front of ".CRADA Line 190 Text revised as suggested. 893 Lines 261-271 Change all "Mr. Thatcher citations to "Dr. Thatcher" -use is inconsistent Line 271, 274 Text revised as suggested. here. 894 Line 283 Insert "for" art er "rotation" for clarity Line 287 Text revised as suggested. 895 Line 329 "Rate" should be singular(?) Line 334 Text revised as suggested. 896 Lines 330-333 Is the maximum unaccounted for plate motion parallel or normal to the Lines 338-348 Text added to clarify that the trend of the SAF? Please clarify. unaccounted plate motion is a function of the assumed SAF slip rate. where an assumed SAF slip rate of 28 mmlyr results in -6.5 mmlyr of unaccounted plate motion distributed with a trend of N27°W and an assumed SAF slip rate of 32 mm/yr results in -3.5 mm/yr of unaccounted plate motion distributed with a trend of N12*w 897 Line 442 Check spelling of "Mohorovic." Line 453 Text revised as suggested. 898 Line 469 Please change "daps" to "gaps." Line 480 Text revised as suggested. 899 Line 500 Heave is not associated with the presence of a shallow/hard bottom -Line 513 Text revised to state that "seafloor reverberation rather it is related to sea state that may result from the presence of a shallow/hard bottom and heave (vertical motion) of data acauisition vessel" 900 Line 523 Insert "depth" -so ii reads "10 to 15 km depth." Line 537 Text revised as suggested. 901 Line 567 "Investigations" is lower case Line 579 Text revised as suggested. 902 Line 637 Should PPRP comments and Tl team responses be inserted here for Lines 31-32 Statement added to the end of the introduction that Workshop #1 and likewise for WS#2 and WS#3? If not, then please point the PPRP comments and Tl Team responses are the reader to where thev can be found. included in the oroiect files. 903 Line 672 Consider deleting first "sensitivity." Line 655 First "sensitivity" in sentence was replaced with "SSC framework" 904 Lines 822-824 Did Hamilton conclude or present this or is this inferred by the Lines 836-839 Tl Team inference of his model removed from the relationships he reported -if the latter might want to consider deleting. discussion. 905 Line 889 Clark reference? Line 902 Text revised to state "Clark et al.. 1984" instead of "e.g., J. Clark"; reference added to reference list 906 Line 981 Replace "or" with "to" Line 994 Text revised as suggested. 907 Line 988 In the near "shore," i.e .. add "shore" Line t001 Text revised as suggested. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT 908 Lines 1077-1078 This might be stated more accurately as incorporating the additional Lines 1089-Text added to clarify this statement: ... beyond the uncertainty that would result from considering non-Poissonian temporal 1092 traditional Poisson recurrence distribution by models, such as a renewal model. considering non-Poissonian recurrence models (e.g., Brownian Passage Time or other renewal models). 909 Line 1116 Replace "N." with "Dr." Line 1130 Text revised as suggested. 910 Line 1131 Should PPRP comments and Tl Team responses for WS#2 go here? Lines 31-32 Statement added the the indroduction section. 911 Line 1225 Insert "then" -so it reads "then replaced." Line 1239 Text revised as suggested. 912 Lines 1259, 1262, "Mr. Abrahamson" should probably be replaced by "Mr. AbramsonWard". Line 1273, Text revised as suggested. 1277 Please check and correct if necessary. 1276, 1291 913 Line 1289 Spell out "HIV" ("horizontal to vertical") for clarity Line 1284, Text revised as suggested. Line 1295 914 Line 1290, 1291 Replace "Mr." with "Dr." Line 1305, Text revised as suggested. 1307 915 Line 1291 'These data yield". Actually, these are not data, but rather. Line 1297, Text revised as suggested. interpretations. 1314, 1471, 1476 916 Line 1312 Please replace "frequency" with function" to reflect the correct Line 1327 Text revised as suggested. interpretation of "CDF." 917 Line 1385 "and is it ready ... " would read more clearly if written "and questions Lines 1391-Text revised as suggested. whether it is ready ... " 1392 918 Line 1393 Replace "The" with the" Line 1408 Text revised as suggested. Also add period at end of sentence. Check the other PPRP sentences like this one as thev also are missino periods at the end of the sentence. 919 Line 1400 Replace *'generals with **general." Line 1415 Text revised as suggested. 920 Line 1608 Replace period with a question mark. Line 1623 Text revised as suggested. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT PPRP COMMENTS AND Tl TEAM RESPONSES, APPENDIX E Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision APPENDIX E -Data Summary and Geospatial Databases 921 Line 3 Data is plural, so change "was" to "were" Line 3 Text revised as suggested. 922 Line 40 Insert "the" between "as .. and "Shoreline" Line 47 Text revised as suggested. 923 Page Y-Replace "maps .. with map Page E-2-3 of Text revised as suggested. 8 Attachment E-2, Folder Folder name name .. \Geographic_fe .. \Geogr atures aphic_f eatures 924 Page Y-(198") year? Page E-2-15 of ..... had been listed because the exact date was 20 Attachment E-2, unknown. Text revised to state that the date is unknown. Folder Folder name .. \ name Other_ data\Core .. \other_ hole _locations data\Div er_geol ogy COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT PPRP COMMENTS AND Tl TEAM RESPONSES, APPENDIX F Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision APPENDIX F -Earthquake Catalogs 863 Line 28-Please consider whether there is actual support for the claim of "better -Lines 32-35 Comparative statement deleted as suggested. Text 29 quality relocations than other available methods." Inserting this claim does describing the important tomoDD attributes (improved not appear to add any useful information, and an option would be to absolute and relative earthquake locations by delete the comparative statement and instead to state what specific incorporating ray tracing in a 30 velocity model and attributes tomoDD provides that proved important to the outcome. differential travel-time data, respectively) was added. 864 Lines States that focal mechanisms were assigned a quality rating of A through Lines 117-125 Text revised as suggested. Quality criteria of Hardebeck 104-108 C, but the lower-quality D rating was introduced. It would be clearer to and Shearer (2002: quality of A -C) are defined, as well state that they were assigned a quality rating of A through D, and then as well as quality D (Hardebeck's examination of polarity qualify the various ratings. data and visual inspection of solutions that did not meet at least one of the Hardebeck and Shearer (2002) criteria). 865 Lines These two sentences sound contradictory, ie., there is "no material Lines 178-182 Text revised to state that there are few differences 143-147 difference," yet there is a "difference of note." Please reword to avoid the between the datasets. Reference to Chapter 12 of the appearance of inconsistency. report is made for discussion of the location of the Given the differences in locations, what was done? Either state the Lompoc earthquake. decision here or point to where it is discussed in the report. 866 Line Refers to attachment X-3, but this was not provided. Same with Lines 145, These are provided as separate text documents. 161 attachment X-4 on line 173. 146, 149, 166, and 197 867 Citation These are electronic files provided to S. Thompson, but where are they Attachment F-Included as Attachments F-3 and F-4 to this appendix. sPG&E now? If someone wants to look at these files, how would they acquire 3 and 2014a them? Is there a URL that can be referenced? Attachment F-and 4 2014b 868 Figs. X-The explanations of these figures have the same spelling errors noted in Figs. F-1, F-3, Figures revised as suggested. 1, X-3, figs. 13.3. 13.4 and 13.5. and F-4 and X-4 COMMENT-RESPONSE LOG DIABLO CANYON SSC STUDY DRAFT REPORT PPRP COMMENTS AND Tl TEAM RESPONSES, APPENDIX G (WAACY MAGNITUDE PDF) Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision APPENDIX G -WAACY Model 785 Line 27 Might want to use another word than characterize as ii might introduce Line 5 Text revised as recommended. "describe" chosen instead confusion with "characteristic model" 786 Line 34 Is this the motivation that the authors of the model had for developing Line 13 Text revised to past tense as recommended it in the first place? If so, this should be past tense. 787 Line 44 Any recurrence curve, by definition, permits a broad aleatory variability Line 25 Broad aleatory variability was not described as a constraint It in magnitude. Not clear that this is an actual constraint. Isn't the real was described as a need. The real constraints are exactly as constraint that large Mmax*s are allowed (more than the characteristic stated in this comment (large Mmax's and small CVs), and are earthquake model) and small CVs are met (unlike the exponential described in the previous sentences. model)? The text has been revised to emphasize that the need was for aleatory variability in magnitude above Mchar. 788 Line 47 Note the missing")". Line 34 The descriptor "hump" has been removed 789 Lines Please clarify what the distinction is between "fits a doubly-truncated Line 39 Text changed to read " ... is a doubly truncated ... " 52-53 exponential" and "is a doubly-truncated exponential". 790 Line 68 Mmin of 5 is used for hazard integration, but is not common practice Table G1 Table entry revised to clarify that Mmin of 5 is a standard of for purposes of earthquake recurrence, especially when fitting practice for PSHA recurrence curves to observed seismicitv. 791 Line 68 "Values larger than 3 yield results that are indistinguishable from 3 for Table G1 Text revised as recommended Table the DCPP." This is a bit confusing. Why not state that "values of 3 and W-1, larger yield results that are indistinguishable at DCPP" bh;gh box 792 Lines What units are used in Dave? Centimeters? Meters? Lines 70-72 Not critical to the appendix. The equations have been removed 78-79 from the body of Appendix G, and are included instead in Attachment G1. 793 Line 92 Replace S08, 13 with S09, 13 Line 81 Text revised as recommended. 794 Line Please check whether this is the first reference in the text (apart from Line 84 Text revised as recommended 104 Table W-1) to the 0.55 value of the displacement CV threshold. If so, please indicate here that you refer to the 0.55 threshold estimated by Hecker et al. (2013). 795 Line Suggested should maybe be "suggest". as it still applies. If accepted, Line 88 Text revised to present tense. Suggests is used to agree with 139 change "included" in line 140 to "include" inspection. Include is used to agree with parameters. COMMENT-RESPONSE LOG DIABLO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 796 Line II appears that instead of "values and weights of the fixed parameters Lines 95-96 *weights" is deleted to clarify. 142 being shown in Table W-2, it is actually parameter name and fixed value. Please clarify. 797 Lines "We note that for Group B cases, the parameter combination of 12% Figure G-4 The logic is as follows. 209-moment and b,,,9,, = 1 exceeded the CV threshold value of 0.55 (Figure On figure G-4c, the three points above the CV threshold are all 211 W-5)." btail = 1. Since btail = 1 is given a weight of 0 for group C, all other values are under the CV threshold. For group B, which Please discuss weighting for Group B versus Group C for 12% has low weight on btail = 1, half of the group B points are moment in Figure W-7. Based on Figure W-6, It appears that Group C above the line. Thus, for non-zero weighted alternatives. group should have an equal or lower weight than Group B for the 12% B performs more poorly for F1 = 0.12 than group C. moment? We note that, since the revised parameters, the groupings have less distinction. The review comment is noted and the Tl Team judges that the difference in weights across the groups has negligible impact on hazard. especially given the sensitivities in Chapter 14. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT PPRP COMMENTS AND Tl TEAM RESPONSES, APPENDIX H Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision APPENDIX H-Method For Estimating Time Dependent Fault Hazard in the Absence of an Earthquake Recurrence Record 499 Line 45 "Poisson probability distribution of ground rupturing earthquakes is Distribution of what? And, in fact, the Poisson distribution itself (probability of exactly n occurrences in a given time interval. as a function n) is never used in the report. Please consider changing to a more Lines 47-48 precise statement (e.g., "the model of ground rupturing earthquakes as a reworded Poisson process assumes that events occur randomly in time"). 500 Line 47 rrhis would be clearer if "to occur" is inserted between "more likely" and 'when the energy Line 49 done 501 Lines 58-60 PSHA also initially did not consider the faults that gave rise to earthquakes; seismic sources were source zones, each of which likely included Rewritten to open the paragraph with this point. faults. The point should be made early in this section that the whole Lines 59-60 Historical reference for PSHA was distracting, and ime-dependent recurrence concept is for fault-specific recurrence removed. behavior. 502 Line 66 rrhe word "be" seems to be missing between cannot" and "rigorously". Line 65 Yes, fixed. 503 Lines 67-68 Consider indicating that an additional reason for the use of the Poisson model is that regulatory design criteria are expressed as target annual of exceedance (e.g., 10-4) without consideration of any time klependence. Lines 66-69 Good, added. 504 Lines 70-71 Bui. as you discuss below. the use of an equivalent Poisson rate does NOT require a change in the hazard code, just inclusion of the concept in the Lines 71-75 This section has been rewritten and hopefully clearer. SSC model. Please clarify. 505 Line 97 'Cumulative density function" is incorrect; please rewrite as cumulative klistribution function." Line 99 yes, changed. 506 Line 162 rrhe phrase "before reaching the long-term mean" could be misinterpreted o mean that the CP ratio is asymptotic to the long-term mean. which isn't Lines 148-150 Text has been reworded. The asymptotic value depends l)enerally the case. Please consider rephrasing to avoid ambiguity on this on the recurrence model width parameter. ooint. 507 Lines 166-Are you saying that we have absolutely no idea what the value of these 167 parameters might be? Or that we have no direct data upon which to base Lines 151-153 No, not the intent. Reworded. hem. but they can be estimated with considerable uncertainty? 508 Line 180 rrhe phrase "although it coincides numerically with the data estimate of the Reworded along the lines suggested in the comment. more familiar coefficient of variation" seems unnecessarily cryptic. Since. in Matthews et al. (2002) prefer the term aperiodicity as a its role as a parameter in a PDF (Eqn 10), alpha is equal numerically to the Lines 161-162 more general description, and their paper defines BPT in CV, please clarify why it cannot simply be said to be the CV. seismological use, so mention of aperiodicity is to respect their more mathematically informed preference. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 509 Lines 205-statement is not always true for faults having good paleoseismic data. The sentence starts "Individual values for Dare not 206 Please qualify that this information is assumed to not be known for the Line 185 normally known,", and explains what we do when Dis *aulls in this exercise. not known. 510 Line 210-211 'The distribution conveys a relative agnosticism among choices in lclisplacement per event (DPE) from 1.5 meter to 3.5 " Line 191 Fixed in text. Figure EPR-3 shows DPE from 1.5 -3. 511 Line 213 Up to 5.0 m in the text of the report (line 258, page 14 of chapter 11 ). Please check and rectify if different. Line 192 5.5 m was intended. 512 Lines 214-Please consider changing to the following (less fragmented) -216 In California. for example, the largest measured average slips per event on he San Andreas fault are 4.45 and 4.3 mlevent for the 1857 and 1906 earthquakes, respectively (Biasi et al., 2013). Lines 194-196 Changed as recommended. 513 Lines 218-22 reference to an upper bound of 5 mlevent in the text appears to conflict lwith values up to 5.5 mlevent given by the solid curve in Figure 3 (there is a Plots have been modified to end at ranges shown in the break in slope at 5.5 min the plot, indicating a non-zero probability point at text. The DPE is implemented as a list with non-zero hat value of sliplevent). Likewise, reference to an upper bound of 4 Figure H-3 entries for the Hosgri from 0.5 to 5.5 in 0.5 m mlevent in the text appears to conflict with values up to 4.5 mlevent for the increments, but the plot incorrectly implies weight above lclashed curve in the plot. Please check and make any changes required for 5.5 m. The same shape considerations affect plots of lconsistency. other OPE curves. 514 Line 227 If L TM is displacement per event divided by fault slip rate, then L TM must be an inverse rupture rate (or mean recurrence time), not a rupture rate as Line 206 LTM does have units of mean recurrence time. Text in stated. Please check the text for consistency and correct as necessary. the affected area has been modified accordingly. 515 Line 247 Please replace "to" with "do" Line 225 done 516 Line 265 If the reference to Philibosian et al. is the same article listed in the references section, then it should be cited as 2011 (rather than 2012). Line 243 Revised to 2011. Please check and make a correction if necessary. 517 Line 268 lsince the EPR is a dimensionless ratio, not a rate, it would be clearer and less subject to confusion to call it something else. Later the EPR is The EPR is a ratio, as noted by the reviewer. The text estimated from the distribution of "conditional probability ratio (CPR)", nla erminology that explicitly indicates the dimensionless character, so calling (and several figures) have been modified accordingly. EPR a rate and CPR a ratio is a source of confusion Please consider this point. 518 Line 275 Please replace "complimentary" with "complementary." Line 266 Yes, fixed. 519 Line 283 IA comma is needed after "renewal" to set off the first part of this sentence Line 275 Done 520 Line 284 tThe tl TM" appears to be a typo-please check whether this should be Line 276 Fixed as suggested, and the word "small" removed 'LTM". because it conflicted with the direction of the sentence. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 521 Line 286 It will cause confusion to say that the CPR is elevated relative to the Poisson rate, because the former is a dimensionless ratio and the later is Wording has been changed to distinguish between the l'ln absolute rate (events/unit time). Please rephrase this to be more Lines 278-279 ratio and the corresponding rate. precise. 522 Line 286 rrhe distinction between CPR and EPR is never stated explicitly, and this l'.;auses confusion later on. The eventual impression is that CPR is treated The first paragraph under "Estimating Equivalent 11s a random variable and EPR its estimated value: if so. please consider Lines 245-259 Poisson Ratios" is largely new and dedicated to clarifying making this explicit, and if not, please add text to clarify the the relationship between CPR and EPR. The second mathematical/conceptual distinction between them. paragraph covering Figure 5 has also been rewritten. 523 Line 288 rrhe phrase "declines to approach the Poisson rate at the upper probable range of tMRE" may be misleading. First of all, since EPR is a ratio, it approach unity if the CP approaches the Poisson probability? If This section has been reworded and the explanation please rephrase to make that clear. Secondly, the phrasing can be Lines 279-286 interpreted to imply that the approach to the Poisson rate is an asymptotic extended. behavior. As that is in general not the case, please rewrite to avoid that impression. 524 Line 297 rrhe peak appears to occur below the diagonal in Figure 6. not above the kliagonal as stated. Please add clarification or correct the statement or Lines 296-300 Rewritten. "igure as necessary. 525 Line 303 rrhe term "joint probability surface" appears to be used here to denote a 'oint probability density. However, this is not made explicit. and doubt is raised by Figure 7, in which it is obvious that the integral under the surface The explanation of the joint probability surface used for is much greater than 1. ruling out its interpretation as a joint PDF. Further Lines 301-311 weighting has been extended and clarified. The fact that arises from Equation 13, as discussed in a subsequent comment. Figure 7 was normalized by its maximum value has been Please be explicit and precise about what is meant by "joint probability stated in the text. 526 Line 303 rrhe joint probability appears to depend upon slip rate. If that is a correct interpretation, please indicate (in the text and caption) what slip rate was used to generate the probability function in Figure 7, and confirm that that Remarks on the relationship of slip rate to individual EPR rate plus the Hosgri OPE model of Figure 3 was the basis for the Lines 301-311 estimates were added in a new paragraph inserted to marginal distribution p(L TM) used to generate that figure (or if, that is introduce the "Estimating Equivalent Poisson Ratios" incorrect, give the correct explanation). If the joint probability does not section. k!epend upon slip rate, please improve the description to make clear why not. 527 Line 308 rrhe survivor function S(tMREIL TM) integrated over tMRE (for fixed L TM) is not generally unity. p(L TM), being a PDF, does integrate to unity. So W integrated over the tMRE,L TM plane is not generally unity. Therefore Wis not a joint probability density, yet the text gives the impression that it is The survivor function actually does have unit area, by intended to be just that (though that interpretation is also cast in doubt by construction. This was obliquely the point of the Figure 7. as noted in a previous comment} If W is something other than a Lines 313-320 sentence in former lines 313-315. The discussion of oint PDF. please explain clearly what it is. If W is a joint PDF. but the weighting, area of the S. and the mathematics have reasoning in this comment to the contrary is incorrect. please clarify in the been rewritten. ext why there is no contradiction. Otherwise make necessary corrections that W can be properly considered to be a joint PDF. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 528 Lines 313-15 sentence seems correct, but it is confusing because its intended purpose is unclear. Is it simply intended to point out that the variates tMRE l'ln d LT M are not independent (because the factor S in Eqn 13 depends not ust on tMRE, but also on L TM), so that (by definition) the joint PDF is not Lines 313-320 Rewritten to move the point earlier in the paragraph. the product of the marginal PDFs? Please rewrite or amplify to K::larify the intended meaning. 529 Line 320-321 horizonal axis in Figure 8 is labeled "Equivalent Poisson Rate" (and EPR is indicated in the caption), but the text seems to indicate that this axis represents the random variable CPR, not the estimated value EPR. and his interpretation is reinforced by the fact that the plot is presumably the GDF of a random variable (i.e., CPR). Please review and Line 327 The use of "Rate" has been revised to "Ratio". modify as necessary to make the text and Figure 8 consistent, and to make K::lear the conceptual distinction between CPR and EPR. The same K:;omment applies to Figure 9. 530 Line 320-321 apparently the curve in Figure 8 is a CDF (or the complement of its maximum value should be 1. This is not clear in Figure 8. If in fact he curve does rise rapidly to intersect 1 at zero CPR (and from looking at Figure is slightly modified to clarify the location of the Figure 9 it becomes clear that it does), to avoid any confusion, please Figure H-8 curve as it approaches 1.0, and notes are added in indicate that fact with a modification to the figure or a note in the caption figure EXPLANATION box. 531 Line 335-336 Please explain the meaning of the vertical dashed lines in Figure 9. Lines 344-345 Description added. 532 Line 343 Please review the use of the term "marginal distribution" here. Wouldn't The intended meaning is as the reviewer indicates, a marginalizing on tMRE mean integrating over it. whereas what is proposed delta function on tMRE=t_eqk. Because the weighting is is concentrating the tMRE dependence in a delta function delta(tMRE-done on narrow discrete values for tMRE, a single _eqk) to begin with. so W=p(l TM) x delta(tMRE-t_eqk)? In what sense is it Lines 352-354 column remains across the range of L TM. The reduction rue that "the equality constraint is a form of marginal distribution"? shares in common the idea of reducing a range on L TM-tMRE to a range on L TM alone, but it is not done by integrating, and thus is not a true marginal distribution. The relevant wording has been revised. 533 Line 396 It is a little recursive to say that values of parameters used for Figure 12 Confusion was introduced by the author because of an were fixed to the values used in Figures 9-12. Please consider revising this. Lines 401-404 incomplete editing of the draft. Back reference to Figures 9-12 is removed and the sentence has been reworded 534 Line 407 Figure 13 has not been cited prior to this citation of Figure 14. Please check whether the figure currently labeled 13 should be deleted and figures The former Figure 14 (Weibull) has been moved to K:;urrenlly labeled 14 and 15 should be relabeled t 3 and 14. If so. then the Line 413 Figure 13. A new Figure 14 is added that more directly K;itation at this point in the text should be Figure 13 (and subsequent figure compares the three time-dependent models. This K::itations are already correct). comparison is promised in Chapter t t text. 535 Line 426 would be useful between "principle" and "slip rate". Line 444 Done COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 536 Line 456-457 Please explain the connection between the weighting method implemented The maximum likelihood approach underlies our EPR here and a maximum likelihood perspective. estimation because weighted solutions are extracted using joint L TM-tMRE probabilities. However. we Lines 4 7 4-4 76 reworded to replace the ML mention with a more important observation that the action of the survivor function to cut off right probability space leads to stability of the EPR estimate across recurrence model functional forms. 537 Line 466-467 Please provide references for the cited MFD functional forms. Lines 483-485 Reworded 538 Figure 5 Please correct the following deficiencies in the figure: 1. The caption is inadequate. It shou Id provide additional information, including at least the CV used to generate the plots, the meaning of the circles in the upper right panel, and the meaning of the curve cutoffs in the lower panels. It should also properly indicate the nature of the Figure H-5, Line are not all lognormal distributions, as the caption would 261 Revised. even though they are all quantities derived from lognormal ktistributions. panels are called out by letter (e.g., "Figure 5d") in the text, but they not labeled with those letters. 539 Figure 7 Please indicate in the caption what slip rate was used to generate this l:!xample. what OPE model was used ( Hosgri OPE model of Figure 3?), Figure H-7 Revised what CV was assumed. 540 Figure 8 Please indicate in the caption the meaning of the red stars. Figure H-8 Revised 541 Figure 9 Please define the symbols, either in the legend or the caption or both, as well as stating the meaning of the vertical dashed lines (which do not seem o be mentioned in the text either). Please also improve the figure title, Which is rather cryptic (what does "Four Tmin,LN", mean, for example?). Figure H-9 Revised please review the use of EPR for the title and horizontal axis, and make changes as necessary to ensure consistency with the discussion in he text and with any intended distinction between EPR and CPR. 542 Figure 10 Please write a more complete caption for this figure. Is it based on the Hosgri OPE model? What are the dotted lines in the upper panel? Tmin is in the legend. but not clearly identified there, so it also should probably be given in the caption. Figure H-10 Revised 543 Figure 12 Please improve the caption. At the least, the meaning of the colors should be explained. H-12 Revised 544 Figure 13 rrhis figure may be redundant. Please check whether that is the case and This Figure 13 became Figure H-14. It shows the BPT ktelete if appropriate. H-14 results. 545 Figure 14 Please check whether this figure should be relabeled "Figure 13". H-13 Yes, this figure has become Figure H-13. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 546 Figure 15 Please check whether this figure should be relabeled "Figure 14" and write informative caption (which should include deciphering "BWM"). H-15 Revised, Figure H-15 is correct. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT PPRP COMMENTS AND Tl TEAM RESPONSES, CHAPTERS 1 TO 4 Location Comment Location in Text Number inText1 PPRP Comment for Summary of Revisions to Report Comment Revision General Comments The report is generally well written and comprehensive. Comment acknowledged. The entire The entire text would benefit from a thorough technical report, figures and appendices are edit. This edit would ensure the consistent use of tense being edited by a professional Text throughout the text, maintain the consistent use of the Editor. 1 third person, ensure the consistent use of terminology, remove redundancies from section to section, and correct typographic errors. We have not attempted to provide such a technical edit in this review but have focused on technical justification and clarity. In some cases, where errors are obvious to us, we have noted those. In several instances, the absence of figure captions Figures are produced using the PG&E detracts from the usefulness of the figures. Figure titles Report Style Guide, which requires a are important, but they do not provide the link from the title block. The title block limits the image to the technical arguments being made in the text. length of the figure caption. Where We strongly urge that figure captions be developed for all possible, we have added "Notes" to the of the figures that provide a summary of the salient body of the figure to provide additional elements of the figures that are being presented, and the explanation. key technical conclusions that the authors would like to 2 portray. The fundamental technical arguments and detail will still reside in the main text, but the figures will carry additional meaning when they are accompanied by captions that highlight those arguments. Further, the captions will provide an opportunity for the various panels of a figure to be defined and discussed, without forcing the reader to flip back and forth between the main text discussions and the figure. Figure captioning of the type requested is standard for a report of this kind. 3 We recognize that the SSHAC process allows for the Comment acknowledged. Text has 1 Unless otherwise indicated, paragraphs identified are for the section, rather than on the page cited. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location Comment Location in Text Number inText1 PPRP Comment for Summary of Revisions to Report Comment Revision consideration by the Tl Team of all data, models, and been revised to more explicitly identify methods that exist within the larger technical community, Tl Team judgments and to eliminate all including those that have been developed within a QA "personal communications". environment, the peer-reviewed literature. unpublished reports, or otherwise. A vitally important part of the documentation process is the attribution of those data, models, and methods by exhaustive referencing throughout the report. Thus, many of our comments call for more complete referencing of the technical conclusions and assertions made in the text. It is particularly important to indicate which technical assessments have been taken from other sources (with proper referencing) and which have come from the Tl Team itself. In the hierarchy of sources of information, we consider personal communications to be the least defensible, due to the general inability of the report reader to verify their accuracy. We therefore urge the authors to avoid reference to personal communications if at all possible. If any cited source can be made (e.g., reference to abstracts for presentations at professional conferences, reference to presentations made at the workshops and documented in the workshop summaries, papers that have been accepted for publication but not yet published), that would be preferable to a personal communication. If there is no other reference to cite. please consider whether the technical conclusion being made is vital to the SSC model and whether it can be removed from the report. If the conclusion is vital and a personal communication is the only source of information, please consider adding documentation to the report in the form of an appendix. We recognize the need to develop the report in Comment acknowledged. More explicit 4 installments in order to meet the project schedules; cross-referencing to specific sections however, this precludes our ability at this staoe to provide and subsections of the report is COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location Comment Location in Text Number inText1 PPRP Comment for Summary of Revisions to Report Comment Revision intelligent comments on the accuracy of cross-references. provided. We urge the authors to provide the most specific cross-referencing possible to assist the reader in understanding the technical arguments being made. For example, given the scale of this report and the complexity of the technical issues, cross-referencing is essential to guide the reader in seeing how the evaluation of data has led to the development of the SSC model. As the arguments are developed, links within the text will be needed to refer to the specific sections and subsections of the report where the information lies. Simple reference to an entire chapter is not helpful, but reference to specific subsections will be most useful. Hence, once all sections have been written, it is strongly recommended that a single author read through and edit the document with the appropriate detailed cross-references. Reviewing a report in installments is not ideal but required Comment acknowledged. We in this case. Without seeing how the sections in this understand the need for a final review installment interface with other sections, there is a certain upon completion of the entire report. amount of faith that we must have that the technical data and arguments made in other sections will support the 5 positions taken in this installment. Although the comments made in this round of PPRP review provide a comprehensive review at this point in time. we reserve the right to provide additional commentary on the sections of Installment #1 in the future after we have reviewed later sections of the report. Chapter 1 Section 1.0. Suggest adding " ... ground motion at the site as a Line 41 Text revised as suggested. p. 17, 1st function ... " 6 paragraph, last sentence 7 Section 1.0, Please specify if this SSC report will also be an Line 52 The SSC model and SWUS GMC COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location Comment Location in Text Number inText1 PPRP Comment for Summary of Revisions to Report Comment Revision p. 17, pt attachment to PG&E 2015. model reports will be stand-alone paragraph. reports. 4th sentence Section 1.0, Will PG&E documents (e.g., 2015 and others referred to Line 110 Documents related to the SSC study page 17, in text} be accessible on PG&E/LCI share drive? are available on PG&E website 8 2nd {address provided). paragraph 7th line down Section 1, ." ... was conducted from June 2011 to January 2015. Line 54 Text revised to March 2015 9 Page 17, Please change to February 2015, as this date is more Paragraph realistic. 2, line 8 Section 1, Please include the specific date of the kick-off meeting. Line 54 Text revised as requested. 10 Page 17, Paragraph 2, line 9 Section 1.0, 35 working meetings are identified on page 28 and Table Line 56 Text and Table 3-1 have been revised 11 p. 17, 2nd 3-1. Please clarify. to reflect 36 working meetings. paragraph, line 10 Section 1.1, A careful reading of Chapter 6 of NUREG-2117 shows Lines 72-73, Text revised as requested to show 12 p. 18, pt that the options are accept, refine, or replace. There is no 84,98 "accept, refine or replace". paragraph. "revise." Please clarify that the decision here is to replace. 1st line Section 1.1. Please define ISFSI with first usage. Line 79 Text revised as requested. Page 18, 13 Paragraph 2. Line 3 Section 1.1. Will (in prep) documents be made available-Wooddell et Line 92 The Wooddell et al study will be 14 page 18, al. (in prep); please see General Comments regarding provided in Appendix G to the report. 2nd such citations. paragraph COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location Comment Location in Text Number inText1 PPRP Comment for Summary of Revisions to Report Comment Revision 141h line down Section 1.1, " ... regional GPS data. and several offshore studies and Line 87 Text revised as requested. Page 18, seismicity studies ... " Please indicate what types of 15 Paragraph offshore studies were conducted. Geologic? Seismic? 2, line 10 Section 1.1, Please cite published report(s) and/or journal article(s) for Lines 90-92 Text revised as requested to add 16 Page 18, UCERF 3, and update the Wooddell et al. citation if report reference to Field et al (2013) and the paragraph 2, or paper is published (and if not, cite the section of the Wooddell et al Appendix. Line 12: report where that work is presented). Section 1.1, The presence of new data, models, and methods requires Line 97 Text revised as requested to show that p. 18, 2"d that they be evaluated, as defined in NUREG-2117. They "new data, methods, and models will 17 paragraph, do not necessarily need to be incorporated into the SSC be evaluated and integrated, as last model, particularly if they are not found to be technically appropriate, ... ' sentence defensible. Section This is actually an existing regulation pertaining to license Lines 112-115 Text revised as requested. 1.1.1, 151 conditions. The NRG therefore did not "issue" 50.54(f). 18 paragraph, They issued a request for information pursuant to the p.18, first regulation and related to NTTF recommendations. sentence Section " ... site specific earthquake ground motion" addresses Line 130 The term "addresses" has been 1.1.1. Page should use ... " This statement is unclear. Please clarify replaced by "licensees". 19 19, what is meant by "addresses". Paragraph 2. line 7 Section Coppersmith and Bommer (2012) is not listed in the Chapter 2, Reference in text removed from 1.1.1. Page chapter references section lines 75-76 chapter 1, added to chapter 2, and 20 19, 3rd and 512 cited in chapter 2 references paragraph of section, Line 4: COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location Comment Location in Text Number inText1 PPRP Comment for Summary of Revisions to Report Comment Revision Section Please consider referencing the report chapter that Line 154-156 Text revised as requested. 1.1.2, Page presents the sensitivity studies. 21 19, 1st paragraph of section, 2nd sentence: Section Consider whether "complete is the right word here. Line 152 Text revised. The word "complete" is 1.1.2, Page deleted. 22 19, 1st paragraph of section, line 5: Section In the first bulleted line, are location and geometry the Lines 159-178 Text is okay as shown. The 1.1.2, Page only foci in the identification and characterization of active subsequent bullets describe the 23 19, faults near the site? Consider also kinematics, rates, and additional source parameters Paragraph 1 recency of motion. considered. Section The use of the term "explore implies that some things Lines 161-178 Text revised. The word "explore" is 1.1.2, p. 19, were looked at (explored), but weren't necessary replaced by "capture". 24 second included. For example, exploratory studies are a type of bullet sensitivity analysis. If the intent here is to say that the range of uncertainty was "defined" and/or "included", then consider changing the terminology. Section Please consider the suggestion to reference the report Lines 159-178 Text revised as requested. 25 1.1.2. Page section(s) appropriate to each bulleted item. 19-20, bulleted list: Section "Development of fault "fault rupture models" that... " Line 165 Text revised as requested. 1.1.2. Page Please delete fault. 26 20, 1st bulleted line on paqe 27 Section If this is the first reference to "linked ruptures. complex n/a Terms removed from bulleted item. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location Comment Location in Text Number inText1 PPRP Comment for Summary of Revisions to Report Comment Revision 1.1.2, Page ruptures, and splay ruptures", please define or include a 20, 1st reference to report section or other source where they are bulleted line defined. on page Section Please rephrase, as this is a run-on sentence. Line 171-173 Text revised as requested. 1.1.2, Page 28 20, 3rd bulleted line on page Section Please change "incorporates" to "incorporate" as this Line 174 Text revised as requested. 1.1.2, Page refers to "models" (plural) 20, 4th 29 bulleted line on page Section 1.2, Please correct "strike-slip" Line 209 Text revised as requested. Page 20, 30 Paragraph 1 of section, line9. Section 1.2. Please note typo and clarify number of Tl Team Line 229-231 Text revised as requested. Page 21. members. 31 last paragraph of section, Lines 7-8: Section 1.2. Three of six members four of five members not affiliated -Lines 229-231 Text revised as requested. page 21, 3rd unclear which one? 32 paragraph, 7th line down COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location Comment Location in Text Number inText1 PPRP Comment for Summary of Revisions to Report Comment Revision Section 1.2, The 3rd subphrase "(3) ... new methods and ... " Are you Line 233 Text is okay as shown. New methods Page 21. referring to new data? What new methods were used? include the WAACY model and 33 Paragraph 3D seismic is not a new method, although it is newly "rupture source" modeling approach. 3, line 10. applied to the SSC for DCPP. Please clarify what "fundamentally new methods" were aoolied. Section 1.3, "provides our evaluation" -please specify who "our" Line 244 Text revised to show "Tl Team". Page 21, 1st refers to-the Tl Team? 34 numbered paragraph Section 1.5, The references need to be correctly formatted. For Lines 343-352 Reference list has been edited and 35 pages 23-24 instance, there is a U.S. NRC, 2012 and U.S. Nuclear correctly formatted. Regulatory Commission 2012a, 2012b, and 2012c. Please correct these references here and in the text Chapter 2 Section An opinion is a belief that does not require facts or Lines 82-83 Text revised as requested. 2.1.1, p. 25, evidence. Judgment is the evaluation of evidence to make 36 211d a decision. Suggest replacing "opinion" with "judgment." paragraph, 211d sentence Section 2.2, " ... provided for bringing all members of the project Line 157 Text revised as requested. Page 27, team ... " This is awkward. Please rewrite for clarity 37 3rd paragraph, line 3 Section Please note word repetition. Lines 142-145 Text revised as requested. 2.2.1. Page 38 27, last sentence of section: Section "uncertainty" Consider pluralizing this word. Line 194 Text revised as requested. 39 2.2.3. Page 28, Paragraph COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location Comment Location in Text Number inText1 PPRP Comment for Summary of Revisions to Report Comment Revision 2, line 7 Section Please clarify or correct the apparent conflict between this Line 198 Text revised and updated to show 36 2.2.3, page line ("35 working meetings"} and Section 1.0, paragraph working meetings. 40 28, 3rd 2, Line 11. ("53 Working Meetings"). paragraph of section, Line 2: Section In reference to UCERF, are you referring to UCERF3? If Line 267 Text revised as requested. 2.2.3, Page so, please state. 41 29, Paragraph 8, line 18 Section It would be clearer if Dr. Lettis were included in this list, Line 250 Text revised to add Dr. Lettis. 2.2.3, page e.g.," .. consisted, in addition to Dr. Lettis, of Dr .... " 42 29, last paragraph on page, Line 2: Section Please resolve the conflict between this statement that Line 256 Text revised to show Ms. Hanson 2.2.3, page Ms. Hanson was added after Workshop 2, with the joining the Tl Team following 43 29, last statement in Section 1.4, page 23, line 8-9 on page, that Workshop 2. paragraph says that Ms. Hanson was added "Following Workshop on page, 3". Line 8: Section Please check whether the sentence (stating that the Tl Line 256 Text is okay. Ms. Hanson joined the Tl 2.2.3. page Team remained stable throughout the data integration Team following Workshop 2. 44 29, last and model building process) is strictly correct given that paragraph Kathryn Hanson joined the Tl Team after Workshop 3 (if on page, that is the case}. Lines 11-12: Section Inasmuch as "Mr. AbramsonWard and Dr. Thompson Lines 278 Mr. AbramsonWard and Dr. Thompson 45 2.2.3. page were younger scientists," please clarify whether the use of willfully revised the text as suggested. 30, Line 2: past tense here means they are now elderly scientists. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location Comment Location in Text Number inText1 PPRP Comment for Summary of Revisions to Report Comment Revision Section You might also mention that Dr. Rockwell worked on the Line 307 Text revised as suggested. 2.2.4, Page L TSP in the 1980's 46 30, Paragraph 2, line 14 Section Please consider whether this statement is correctly Line 309 The statement is correct as written. We 2.2.4, page phrased, given that Dr. Day's only other SSHAC Level 3 do not say "ALL individuals". 47 30, experience is concurrent with this SSC study. Paragraph 2 of section, Line 10: Section Should read: "For Workshop 3, the members of the Line 318 Text revised as requested. 2.2.4, Page PPRP ... " 48 30, Paragraph 3, line 6 Section Professor of Geology and Geophysics at Scripps Lines 295 Text revised as requested. 2.2.4, page 49 30, 2nd paragraph, 5 lines down Section For completeness. please also note the PPRP's Line 326 Text revised as requested. 2.2.4. page responsibility to review the Project Plan. 50 31, listed items in 4th paragraph of section: Section Inconsistent usage of periods at the end of each bullet. Line 326-337 Text revised as requested. 51 2.2.4. Page Please make them all the same. 31,bulleted items 52 Section In Figure 2-1, SSC Tl Team Staff Support is indicated by NIA Yes, all of the Tl Team support staff COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location Comment Location in Text Number inText1 PPRP Comment for Summary of Revisions to Report Comment Revision 2.2.5, p. 31, an asterisk as being EEs. Is this correct? shown are considered Evaluator last Experts. sentence Section Of course. the REs did not present "raw" data without Line 363 Text revised as requested. 2.2.6, p. 31, interpretation. The important point is that the REs avoid 53 1st providing their interpretations of the data relative to SSC paragraph, issues. That is the puiview of the Tl Team. line6 Section Please replace "several" with "some." Line 369 Text revised as requested. 2.2.6, page 54 32 1st paragraph 2nd to last line Section Please make Analyst was to "Analysts were Line 388 Text is okay. The project utilized only 2.2.8, page one hazard analyst, Nick Gregor. 55 32, 1st paragraph 2nd line Section Ms. Wooddell is identified as one of the Hazard Analysts, Lines 394 Text revised to remove reference to 56 2.2.8, page but her name does not appear in Figure 2-1 (the project Ms. Wooddell as a hazard analyst. 32, 3rd to organizational chart). Figure 2-1 is okay. last line: Section To avoid confusion of roles. consider adding a statement Lines 371-372 Text revised as requested. 2.2. 7. p. 32. that all participants were made aware of the fact that Lines 383-385 57 last members of the Tl Team were assuming the role of PE for sentence purposes of the workshop. and they would then return to their roles as EE and Els. Section Affiliations were given for the people identified above; Line 394 Affiliations and titles have been added 58 2.2.8. p. 32. consider if they should be provided here as well. Likewise (also line 405) for all participants on the project. line? for Serkan Bozkurt in the next paragraph. Section 2.3. Please consider changing the title to emphasize the Line 417 Title of section changed to "Database 59 Section title: studies rather than the contractors (i.e .. the section is Development and New Studies". about the studies, the contractors being important but COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location Comment Location in Text Number inText1 PPRP Comment for Summary of Revisions to Report Comment Revision subordinate information). Section 2.3, It may be useful to explain either in this paragraph or in Lines 456 Text revised as requested. p.33 Section 2.3.2 what the relationship is between the focus of the CRADA and the studies conducted specifically for 60 Diablo Canyon. It may be important to distinguish the role of the USGS, which conducts research for non-site specific applications, versus 1632 studies that are aimed at reducing uncertainties for the DCPP PSHA. Section 2.3, Please consider rewording this to reflect the fact that you Lines 431-433 Text revised as requested. page 33, are summarizing focused studies done by contractors to 61 2nd to last PG&E (you mention the contractors as part of that sentence: summary, but you aren't merely compiling a list of contractors here). Section Is the Diablo Cove fault considered "potentially active? Lines 443-444 Text revised to delete the Diablo Cove 2.3.1, Page Please refer to subsequent discussion of evidence of fault as potentially active. The intent of 33, line 9 Quaternary activity on this fault. In line 14, is the the text in this section is to be agnostic Shoreline-Diablo Cove fault interaction actually as to whether a fault is active or not, considered in this SSC? but to indicate that these faults were 62 considered and evaluated as part of the SSHAC process. Yes, the Diablo Cove fault and potential intersection with the Shoreline fault was considered, evaluated and judged to be not technically defensible. Section " ... and to evaluate slip rate on the Hosgri fault zone." Line 459 Text revised as requested. 63 2.3.2. Page Didn't Sam Johnson actually "develop new slip rate data 34, line 5 on the Hosgri fault zone."?? Section "lineaments in Estero Bay." What type of lineaments? Line 461-462 Text revised to indicate "seismicity 64 2.3.2. Page Topographic? lineaments". 34, line 8 65 Section "San Francisco State" should read "San Francisco State Line 477 Sentence deleted. 2.3.3, Page University" COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location Comment Location in Text Number inText1 PPRP Comment for Summary of Revisions to Report Comment Revision 34, line 9. Section "San Francisco State" should read "San Francisco State Line 481 Text revised as requested. 66 2.3.4, Page University" Redundancy eliminated by deleting 34, line 3. Also, the second line of this paragraph seems redundant sentence in Section 2.3.3. with the previous paragraph/section. Section It is not clear how the listed studies by Tl Team members Line 484-488 Last sentence is revised to provide 2.3.4, page are to be distinguished from "independent new detailed additional clarification on the use of the 67 34, last studies." If the intent of the sentence is to clarify the scope field reviews performed by the Tl sentence of of Tl Team efforts, please reword. Team. section: Table 2-1, Jan Rietman is stated as being affiliated with FUGRO in Line 477 Rietman is shown as being an Page 35 the text and as a consultant in the table-please make independent consultant, per his 68 consistent. Also, please consider ordering the names request. Tables merged and modified alphabetically-this will eliminate the double naming of and moved to Appendix D -workshop participants, as with Phil Hogan in Workshop #2 (listed summaries. twice). Section The Tl Team members in a SSHAC process are expected Line 500 Paragraph revised as requested. 2.3.5, p. 35, to evaluate ALL forms of data, models, and methods. This 2nd includes data gathered under a QA program, data paragraph provided in peer reviewed publications, and data gathered for other purposes. This is because the experts on the 69 Team are capable of evaluating the quality and applicability of those data. models, and methods. This does not mean that the data are "accepted into the SSHAC process" but that the data have been evaluated according to the SSHAC process. Suggest revising the wording in this sentence. Chapter 3 Section 3.1. In Figure 3-1, there are called "essential steps." To avoid Figure 3-1 Figure modified as requested. 70 p. 38, 2nd confusion with the "essential steps" identified in Chapter 4 paragraph of NUREG-2117. suggest calling these four "components" as done in the text. 71 Section To avoid any perception that the PPRP was actually Line 53-54 Text revised as requested. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location Comment Location in Text Number inText1 PPRP Comment for Summary of Revisions to Report Comment Revision 3.1.1, p. 39, involved in the technical integration process, suggest 4th substituting the term "reviewed," or something similar, for paragraph. "involved." last sentence Section 3.2, Where do these Working Meeting summaries" reside in Line 119-126 There are no formal "working meeting 72 p. 40, last the project records? summaries". This clause is deleted sentence from the sentence. Section Please consider reserving the term "Workshop" for those Lines 130-132 Text clarifies that workshop 0 is an 3.2.1, activities specifically defined as workshops in the SSHAC informal workshop. 73 general NUREG documents (for example, Workshops 1,2, and 3 comment: are structured quite formally and documented thoroughly, including a PPRP feedback letter; this was not the case for the kickoff meetinQ). Section Here and elsewhere, please do not use "etc. List out any Line 158-189 Text revised as requested. 3.2.2, Page other items. 74 41, Paragraph 2, line 9 Section significant parameters and features." Please clarify what Line 199 Text revised to say "seismic source 75 3.2.3, Page is meant and implied here. Issues? Data? characteristics". 42, line 9 Interpretations? What are parameters and features?? " Section Consider changing " ... and input into ... " to " ... and added Line 216 Text revised as requested. 3.2.4. Page to .. " 76 42, Paragraph 1. line 4 Section "overlapping day with the GMC to discuss ... " Do you Lines 233-235 Text revised to clarify the 3rd day of the 3.2.5. Page mean GMC Tl Team? Please clarify. workshop. 77 43, Paragraph 1, line 6 78 Section Please delete "etc." and list out any other items. Line 246 Text revised as requested. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location Comment Location in Text Number inText1 PPRP Comment for Summary of Revisions to Report Comment Revision 3.2.5, Page 43, Paragraph 2. line 10 Section "Several of the working meetings were observed ... " This Line 300 Sentence deleted. 3.2.6, Page is redundant with the previous paragraph -already 79 44, stated. Paragraph 3, line 13/14 Section " ... used to form the basis development of ... .. This Lines 322-325 Sentence clarified as requested. 3.2.7, Page statement is unclear. Please clarify 80 45, Paragraph 3, line 5 Section Please indicate where the summary and PPRP letter are Line 310 Reference is given to the workshop 3.2.7, Page located. Appendix D. PPRP letter and response 81 45, are kept in the project files, and are not Paragraph planned to be part of the submittal. 4. last line Section Are these the same as the WM Summaries identified on Lines 355-359 There are no formal working meeting 3.2.8. p. 46. page 40? summaries. This sentence is deleted. 82 1st paragraph, last sentence Section Please delete "etc." and list out any other items. Line 392 Sentence revised as requested. 3.2.9. Page 83 47, Paragraph 2, line 9 84 Section " ... the final model in light of the ... " Consider changing Lines 427-429 Sentence is clarified as requested. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location Comment Location in Text Number inText1 PPRP Comment for Summary of Revisions to Report Comment Revision 3.2.10, Page "in light of" to "using" to improve clarity. 48, Paragraph 1, line 6 Section Please add "fault" after "Hosgri", as it is a formal name. Line 434-437 "Hosgri" text removed from the revised 3.2.10, Page sentence. 85 48, Paragraph 2, line 7 Chapter 4 Section 4.1, Please define FSAR if this is the first usage of this term. Line 39 Modified as suggested. 86 Page 51, Paragraph 4, line 2 Section "proposed Diablo Cove fault" -Is it a fault, or not? Line 68-69 The term 'proposed' has been deleted 4.2.1, Page Please clarify "proposed" 87 51, last line and sentence revised. Section The bulleted items do not have a parallel sentence Line 72-73 Text revised to correct sentence 88 4.2.2, Page structure with the intro. Each should read correctly after structure as suggested. 52, bulleted " ... .included:" items Section University of Berkeley-University of California, Line 100 Revised to clarify 4.2.2, page Berkeley? 89 52, 2nd paragraph, last line Section The first bulleted paragraph is confusing. Please rewrite Lines 108-119 Text revised to clarify. 90 4.2.3, Page for clarity. 52, 1st bulleted item Section If this is the first occurrence of the acronym LESS, please Lines 176-181 Text revised and reference to LESS 91 4.2.4, page define (it may be used freely thereafter, since it does deleted from this paragraph. 53, 1st COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location Comment Location in Text Number inText1 PPRP Comment for Summary of Revisions to Report Comment Revision paragraph of appear in the acronym table). Also, suggest putting "New" section, Line 4: prior to Offshore Section "Report" is repeated, but the acronym does not have an Line 215-216 The extra "report" has been removed. 4.3.1, Page R. Is report part of the official title? Not clear. 92 54, Paragraph 1, line 6. Section "Low-Energy Seismic Survey" and "Onshore Seismic Lines 235-237 Capitalization in the revised sentence 4.3.1, page Interpretation Project" should be written with initial capital was recommended by technicial editor. 55, 3rd letters. 93 paragraph of section, last 3 lines of section, Section If this is the first occurrence of the acronym HFZ, please Line 259-260 Revised as suggested 4.3.1.1, define (It appears in the acronym table, so it may be used 94 page 55, 1st freely thereafter). paragraph, Line 4: Section Non-parallel structure and confusing. Suggest" ... to the Lines 335-338 Agreed. Sentence was revised 4.3.2.1, Hosgri fault zone, were spaced -800 m apart (locally 400 (subdivided into two sentences) to 95 Page 56, m) along an -94 km-long portion of the Hosgri fault zone, clarify and correct. Paragraph and crossed the fault zone 121 times." 2. lines4 and 5 Section Check spelling of "transect" Line 353 Spelling corrected. 4.3.2.1, 96 Page 57, Paragraph 3, line4 COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location Comment Location in Text Number inText1 PPRP Comment for Summary of Revisions to Report Comment Revision Section "available at CSUMB (2010)." Is this a published source? Line 358 Reference added. The site was 4.3.2.1, It is not in the listed references. Please include. Page 57, accessed in December 2014 to confirm Paragraph that there were no newer updates. Text 4, line4 was modified to reflect 2014 reference citation. 97 California State University, Monterey Bay, Sea Floor Mapping Lab (CSUMB), 2012. Multibeam echosounder (MBES) data for the California Central Coast. Available at http://seafloor.csumb.edu/SFMLweb DATA_c.htm (accessed December 2014). Section Sentence is incomplete; please check and correct. Lines 355-356 Sentence corrected 4.3.2.1, 98 Page 57, 5th paragraph of section, 1st sentence: Section "tomoDD velocity model" is very specialized jargon. in the Line 381-382 Sentence revised as suggested 4.3.2.2, sense that "tomoDD" is the name of the computer page 57, 1st program that implements a particular analytical method. 99 paragraph of Please consider rewording, either simplifying to "seismic section, Line velocity model", or to something that references the 3 underlying analytical method, e.g., "seismic velocity model based on double-difference tomoaraohv". Section Suggest moving "by" after (1) to be consistent with rest of Lines 404-408 Sentence revised to provide 100 4.3.2.3, paragraph. consistency in list Page 58, COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location Comment Location in Text Number inText1 PPRP Comment for Summary of Revisions to Report Comment Revision Paragraph 1 Section This sentence is confusing. " ... are incorporated into the Lines 431-432 Sentence was corrected to clarify and 4.3.2.4, characterization of the Irish Hills-Estero Bay Local Areal remove extraneous text. 101 Page 58, Source Zone Irish Hills-that includes the Irish Hills." Paragraph 2 Please clarify. Section Reference section gives author name as Murray-Line 450 Text modified to cite name as shown 4.3.2.5.1, Moraleda, which is not consistent with the citation in this on the report (Murray-Moraleda). Later 102 page 59, 1st paragraph. Workshop presentation correctly cited paragraph, as "Murray" Line 1: Section Rinconada fault2??? Are there two Rinconada faults? Is Line 470-471 Typo corrected in revised text. 4.3.2.5.3, this a typo? Please clarify. 103 Page 59, Paragraph 1, line 6 Section The citation is consistent with the reference section entry, Line 450 Text and reference citation were 4.3.2.5.1, but not with the citation at the beginning of the paragraph. modified (see response to #102) to be 104 page 59, 1st consistent. paragraph, Last line: Section "San Luis/Pismo" is written "San Lui-Pismo" in the list of Lines 623-624 The term has been changed to San 4.3.2.8, abbreviations and acronyms. Luis-Pismo in the revised text 105 page 61, 1st bulleted item: Section Please rewrite this paragraph for clarity. Lines 653-658 Section 4.3.2.9 was modified 4.3.2.9, throughout to clarify the objectives of 106 Page 62, the research and to cross reference Paragraph 1 more specifically to where the new data and information used to evaluate seismic sources was discussed. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT PPRP COMMENTS AND Tl TEAM RESPONSES, CHAPTER 5 Location PPRP Comment Location Summary of Revisions to Report inText1 in Text Comment for Number Comment Revision Chapter 5 Section 5.2, Both SYRF and SYF labeled on Figure for Santa Ynez No change Figure 5-1 is correct. The Santa Ynez 107 page 69 River Fault. Please make consistent. required River fault and Santa Ynez fault are Figure 5-1 two different faults. Section 5.2, States that the contemporary plate boundary is a zone of Lines 95-96. No change; text is correct. Both strike Page 67, strike slip faults and transpressional deformation, but slip and reverse/thrust faults may occur paragraph 1 , wasn't the San Simeon earthquake purely thrust? Plus, Please note in a transpressional tectonic setting. lines 4-5 two of the structural models have the San Luis Bay and that the Los Osos as thrust faults. Is this statement correct? subheading of 108 Please clarify. 5.1 for Introduction was removed and Section 5.2 in previous draft is now Section 5.1 Section 5.2, In the preceding section, the region is referred to as The preceding sentence states "at the Page 68, " ... zone of right-lateral strike-slip faults ... ", whereas many Lines 96-97 latitude of Diablo Canyon" and is not Paragraph of the faults shown in Figure 5.1 are left-lateral or oblique referring to faults within the Western 109 2. line 1 left lateral (Santa Ynez. Lion's Head, Casmalia. etc.). No change Transverse Ranges. Also, the Lion's Please clarify. required Head and Casmalia faults are either reverse or right reverse faults (e.g .. the 1980 Casmalia earthquake). Section Please add a reference for these ages: "(approximately Line 126 The ages shown refer to the age of the 5.2.1. Page 200 to 66 Ma)". 66 Ma may be a bit young for the Jurassic and Cretaceous Period, 110 68, cessation of subduction-related volcanism. as Sierran because this is the time interval Paragraph volcanism and pluton emplacement shut down by about discussed. For clarity, we have deleted 1, line 1 80 Ma, and it was even earlier in the southern California reference to the age. 1 Unless otherwise indicated, paragraphs identified are for the section, rather than on the page cited. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location PPRP Comment Location Summary of Revisions to Report in Text1 in Text Comment for Number Comment Revision Peninsular Ranges (95 Ma). Are you suggesting that Cessation of volcanism in the subduction ceased at 66 Ma? Clearly, as stated earlier, Cretaceous is not considered relevant the spreading ridge intersected the trench at about 28 Ma to the tectonic setting at Diablo and flat-slab subduction was occurring after-80 Ma Canyon. Subduction of the Farallon (hence, the cessation of Sierran volcanism}. This section Plate beneath North American plate would benefit from additional supporting discussion and continued well into the Cenozoic. improved referencinQ. Section Would it be helpful to mention the seismicity that is also Lines 175-176 Text revised as requested. 5.2.2, p. 69, projected on to the cross section in Figure 5-4? 111 3rd paragraph, line8 Section Please provide more information or reference to support Lines 176-178 Text revised to state "top of the imaged 5.2.2, page "surface slab does not appear to be disrupted by crustal slab appears continuous and does not 69 faults". Is this based on microseismity?? appear to be vertically offset or 112 3nd disrupted ... " paragraph 10 lines down Section Please provide the basis for this interpretation or make Lines 178-179 Reference is made to Sections 5.1.5 5.2.2, p. 69, reference to a section of the report where the issue of the and 7.2.1 for assessment of 3rd top of the slab relative to the Hosgri fault is discussed seismogenic thickness. 113 paragraph. further. second to last sentence Section Onderdonk (2007) is cited but does not appear in the Line 1203 Onderdonk (2007) is added to the 5.2.3. page references section. reference list. 114 70, 2nd paragraph of section, Line 7: 115 Section It is stated here that subduction ceased 22-20 Ma at the Lines 135-209 Text revised to clarify timing. and 5.2.2, Paoe latitude of DCPP, but it is earlier stated that the spreadinq location of subduction. Reference to COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location PPRP Comment Location Summary of Revisions to Report in Text1 in Text Comment for Number Comment Revision 69, 3rd ridge contacted the subduction zone "directly south" of specific age is deleted. Paragraph, DCPP. which would imply a timing close to 28 Ma. In line7 contrast. figure 5-3 suggests that contact occurred near present-day Los Angeles. Please clarify or correct. Section There is a lot of detail with no referencing, and alternative Lines 135-209 Text modified to provide additional 5.2.2, Page interpretations have been proposed in the literature. For clarity. The reference to Gulf of 69, 2nd, instance, the notion that the main plate boundary jumped California is deleted. Much of the 3rd and 4th inland at 5 Ma is contradicted by many studies. There discussion in these paragraphs is from Paragraphs was clearly part of the main plate boundary already inland Atwater and Stock ( 1998). 116 by 12 Ma -hence the Miocene activity of the San Gabriel fault and the development of Ridge Basin (Crowell refs). Oskin and Stock argue for an earlier opening of the Gulf, as does Fletcher, and that the "proto-Gulf" is really no different than the modern Gulf of California, except where the locus of extension occurred. Please provide complete referencing in these paragraphs. Section "full plate motion of 30 to 35 mm/yr during the late Lines 286-314 The change in plate rate and 5.2.2, Page Miocene." According to many references, the full plate orientation is directly from Atwater and 70, 5th motion during the late Miocene was no different than it is Stock (1998). The change in rate 117 Paragraph, today --52 mm/yr. Please provide additional justification occurred about 12 Ma; the change in line2 and references, and specify the timing of the increase in plate orientation occurred about 8 Ma. rate ( 12 Ma?) Additional text has been added for clarification. Section Please complete the citation for Atwater (2011) or provide Line 138 URL has been added to the reference; 5.2.3. page an online URL. and sentence has been moved to the 118 71, 4th introduction paragraph of Section paragraph. 5.1.2. line4 Section If the San Miguelita and Edna faults were active at this Initial As discussed further in this Section. 5.2.3. page time with lateral slip. the model requires them to be left-comment in the sense of lateral slip on these faults 119 71, 4th lateral. Is this model consistent with observations? not changed. is poorly constrained by data. The text paragraph, Please elaborate. Discussion of describes two "models"; the model by line8 models in Luyendyk (1991) which shows these lines 272-285 faults as dextral slip, and the model by COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location PPRP Comment Location Summary of Revisions to Report in Text1 in Text Comment for Number Comment Revision Wilson et al (2005) which shows these faults as first left lateral. followed by right lateral. Section Please consider whether the topic of "early sinistral Lines 272-285 The paper by Wilson et al (2005) 5.2.3, page transtension between blocks and later dextral presents a palinspastic reconstruction 71, 5th transpression" is discussed in Wilson et al., 2005. The of the WTR and Los Osos domain area paragraph, paper is focused on the correlation of volcanism and slab in Figure 8. This figure shows an initial 120 last windows and does not appear to address the topic period of left lateral faulting followed by sentence. identified. If it does not, please provide a proper citation right lateral faulting as described in the for this concept. Also, please explain why many of the E text. to NE-striking faults (Santa Ynez, Lions Head, etc.) continue to have late Quaternary left lateral or oblique LL motion. Section Here it is stated 6.3 to 4.7 Ma. Earlier 5 Ma is used. Line 299 Text revised to say 5 Ma, consistent 5.2.3, page Please be consistent and provide a reference for this with the model from Atwater and Stock. 72, 6th timing. 121 paragraph, line 9 from top of page COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location PPRP Comment Location Summary of Revisions to Report in Text1 in Text Comment for Number Comment Revision Section Please provide a reference for the statement that rotation Lines 327-332 The text is modified to show a Tl Team 5.2.4, Page in the WTR has stopped. This is a key issue as it affects assessment that the rotation has 72, expected motion on W-NW striking faults in the Santa slowed, in part supported by Marshall Paragraph Maria basin province (Los Osos domain) -should see et al. (2013). 1, line 3 continued left-lateral oblique slip if rotation continues. At least some faults remain active, and Holocene left-lateral has been demonstrated on the Santa Ynez fault. 122 COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location PPRP Comment Location Summary of Revisions to Report in Text1 in Text Comment for Number Comment Revision Section Please replace Carreaga with Careaga Line 325 Text revised as requested. 5.2.4, page 123 72, 1st paragraph 3rd to last line Section What sense of strike-slip? -please indicate. Within the Lines 348; As defined by Lettis et al (2004), the 5.2.5, Page Los Osos domain, the Shoreline fault is presumed to be lines 334-362 Santa Ynez fault is within the WTR, 73, right-lateral based on seismicity and obseived offsets, and is not part of the Los Osos domain. Paragraph whereas the San Ynez fault is left-lateral in the Holocene. Furthermore, the fault strikes east-2, line 4 Other faults, such as Casmalia, Lions Head, Santa Ynez northeast, in contrast to the northwest-River faults, may be left oblique in terms of overall striking faults of the Los Osos domain. 124 displacement, but Holocene slip and kinematics is not The text is revised to indicate faults well-documented. Please explain the inter-relationship of within the domain accommodate these structures and how they can be right-lateral near "dextral" slip and to provide additional the Hosgri and left-lateral farther inland. clarification. The Tl Team judges the Casmalia, Lion's Head and Santa Maria River faults to be either reverse or right-reverse faults. Section Here it is stated that faults in the Los Osos domain are Lines 363-368 The text states that the eastern and 5.2.5, Page dextral or oblique. Does this include the Santa Ynez and western boundaries of the domain are 73, other sinistral faults? These relationships should be marked by dextral faulting. The text of Paragraph explained. It is stated later that the San Luis Bay fault is the previous paragraph is modified to 3, line 2 reverse to left oblique based on kinematic indicators. clarify that faults within the domain are 125 Please provide clarification. interpreted to accommodate reverse, right-oblique, or dextral slip. The rake of the San Luis Bay fault is assessed to be dominantly reverse with minor uncertainty in either direction {Section 8.6). Section Here the concept is introduced of continued clockwise Lines 379-381 In all alternative models, the 126 5.2.5, Page rotation of the WTR. If correct, this could cause a contemporary sense of slip on faults in 74, component of left slip on all of the faults in the Los Osos the Los Osos domain would be reverse Paraoraph domain, as thev are beino extruded to the NW. How does or dextral-reverse slip. Text is modified COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location PPRP Comment Location Summary of Revisions to Report in Text1 in Text Comment for Number Comment Revision 3, 3rd this work -please explain. to provide additional clarification. bulleted item Section Please provide a reference to support the last line of this Line 394-395 Reference added {Lettis and Hanson, 5.2.5, Page paragraph, which starts: "Evidence for downdropped or 1992) 74, static ... " 127 Paragraph 4, last line Section Please provide a reference for the statement that the San Lines 409-415 References provided {Lettis et al, 1994; 5.2.5, Page Miguelito, Edna, and Pismo faults do not deform 2004 ). Additional text added to clarify 128 74, Quaternary deposits. Also, please specify where -the location. Paragraph Edna may not be active in the Irish Hills, but may be 6, line 2,3 active to the east. Section If the Los Osos domain is undergoing transpressional No change The Tl Team considered this issue and 5.2.6, Page dextral shear, consider whether this would preclude judges that continued rotation of the 75, opening shortening due to continued rotation of the WTR. WTR, if occurring, would impose a 129 paragraph northeast-directed strain superimposed on the more regional plate margin strain, which has a similar shortening direction. The two do not seem incompatible. Section Please explain why only two solutions are shown for the Figure 5-11 Notes are added to Figure to provide 130 5.2.6. Figure HASH data. Are there sufficient data for more solutions? additional information {criteria for 5-11 minimum events per cell). Section This appears to be a minimum rate based on data (red Lines 514-522 A new reference is added {DeMets et 131 5.2.6 Figure dashed line). Please provide more explanation on how the al, 2014) which refines the slip rate 5-13 budget was determined. budgets and further describes how the geodetic rate was determined. Section Please check spelling of Zheng (isn't this Yuehua Zeng?) Line 469 Text revised as requested. 132 5.2.6. page 75, 2nd bullet COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location PPRP Comment Location Summary of Revisions to Report in Text1 in Text Comment for Number Comment Revision Section Lewandowski and Unruh (2014) is not in the references. Lines 465 and This is a workshop presentation, not a 5.2.6, page 1142 published reference. Text revised for 133 76, 2nd clarity and citation added. paragraph of section, Line 1: Section DeMets (2012) is not in the references. Lines 476, Clarification of 2012a, 2012b added to 5.2.6, page 481, 1021-text; references added. 134 76, 2nd 1027 paragraph of section, Line 4: Section d3/s1 could be mistaken for a ratio, so please consider Line 510 Text revised to say d3 or s1. 5.2.6, page stating this differently. 76, 2nd 135 paragraph of section, 4 lines from end: Section Please indicate how the cited results differ from published Lines 514-522 The results are modified to be 5.2.6, page work of DeMets (2012), and state the basis for those consistent with published results and 76, 3rd differences (or reference the relevant part of the report). the DeMets et al. 2014 reference has 136 paragraph of been added section, 2nd and 3rd sentences: Section Annotations need to be rotated. also OWH has a p = 1.1 Figure 5-15 Figure modified as requested. Yes, 137 5.2.6 Figure mm/yr? NeoKinema results show a shortening 5-15 rate of 1.1mm/yr on the OWH. Section 5.3. Since the sensitivity results are being used to limit the Lines 563-565 Reference is made to sensitivity 138 Page 77. 1st selection of faults for discussion. please provide a analyses in the Shoreline fault report sentence: reference to somewhere in the report where those (PG&E, 2011 ), Workshop 1 (Wooddell, sensitivitv studies are documented. 2011 ), and Chapter 14 of report. 139 Section 5.3, Consider whether it would worthwhile in this introduction Lines 574-580 Text is modified as requested to COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location PPRP Comment Location Summary of Revisions to Report in Text1 in Text Comment for Number Comment Revision p. 77, pt to discuss the concept of defining each fault according to indicate that this is a site-specific paragraph its characteristics along the reach closest to the site. It study. could be important to remind the reader that this is NOT a regional fault characterization {e.g., UCERF3), but a site soecific SSC model. Section "The model results showed more evidence for northeast-Lines 546-551 NeoKinema discussion remains brief. 5.2.6, page southwest directed contraction between the Los Osos Important element for hazard is to 77, 4th domain (east of the Oceanic-West Huasna fault) and the provide the Hosgri slip rate estimate. Tl paragraph, 9 San Andreas fault than within the Los Osos domain itself. Team considers that exploring deeper 140 lines down "Please provide additional discussion about the model as into NeoKinema (e.g., how faults are it appears to be different from other models. constrained to slip; how they are initially parameterized) would be distracting to the streamlined presentation of results. Section 5.3, "active and potentially active" Please provide Line 576 Text modified to delete "active and page 77, 1st criteria/definitions for these terms. potentially active". 141 paragraph, 11 lines down Section Two alternative models are presented, but the wording is Lines 595-605 Text modified as requested. 5.3.1, Page highly asymmetric. The first-cited references "interpret 142 78, 1st recently acquired offshore seismic reflection data to show, paragraph of ... "whereas the latter-cited references "show" the section, Line contrary. Please reword to be consistent with the 7 to 13: statement that these are alternative models. Section "Possible Hosgri fault zone dip angles are shown on Figure 5-17 Figure corrected as requested (please 143 5.3.1. figure BB'." BB' should be AA'. note that this is Figure 5-17) 5-16 Section "San Luis/Pismo block" is written as "San Luis-Pismo Line 618 Text revised as requested. 5.3.1. page Block" in the list of abbreviations and acronyms and in 144(a) 78, 2nd many other places in the report. paragraph of section, Line 10: COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location PPRP Comment Location Summary of Revisions to Report in Text1 in Text Comment for Number Comment Revision Section 'These intersecting faults include the Los Osos, Lines 648-656 All of these faults do, in fact, intersect 5.3.1, Page Shoreline, Casmalia and Lion's Head faults." This seems with or merge with the Hosgri fault 79, to imply that all of these faults exhibit similar kinematics, zone, and thus in some way will Paragraph but that is certainly not the case. The Casmalia and influence slip rate on the Hosgri fault 4, line4. Lion's Head faults are similar to the Los Osos in that they zone. The Casmalia fault is not a left exhibit a large reverse component, but their sense of oblique slip fault. Chapter 8 will be 144(b) lateral motion is unknown, and in section 8, the Casmalia modified to eliminate this mis-fault is inferred to be left oblique to reverse. Please clarify representation. As described in the known sense of slip on these faults, as their sense of Chapter 7, depending on the slip may control the validity of tectonic models, and alternative fault geometry model whether the current transpression I shortening is the (FGM), sense of slip on the Los Osos result of continued rotation of the Transverse Ranges, or fault varies. In all models the Shoreline some other mechanism. fault is strike slip and the San Luis Bay fault is reverse. Section Refers to the Casmalia and Lion's Head faults as reverse Line 648-664 Paragraph removed, as subject matter 5.3.1, Page to reverse oblique. Please indicate the sense of oblique was intruding on Chapter 8. Summary 80, slip, if known (LL or RL) and provide references. statement that changes in Hosgri slip 145 paragraph 7, rate at fault intersections is sufficient line 3 for Chapter 5 scope. Reverse slip of the Casmalia fault is documented in Lettis et al., (2004) Section "southeast" should be southwest. Line 685 Text modified as requested. 5.3.2, page 146 80, 1st paragraph, 6 line from bottom Section Consider breaking up this very long paragraph. Line 717 Text modified as requested. 147 5.3.3. p. 81. znd oaraaraoh Section San Miguelita fault not labeled on figure. Figure 5-16 Figure modified as requested. 148 5.3.3 Figure 5-16 COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location PPRP Comment Location Summary of Revisions to Report in Text1 in Text Comment for Number Comment Revision Section Provides the inferred dip of the SLB fault of-75 degrees Line 737 This comment is removed from 5.3.3, Page and refers to Chs 8 and 9. It is difficult here, and Chapter 5 (Seismotectonic setting). 149 81, last elsewhere, to confirm critical cross-referenced material The PG&E (2014) interpretations of the paragraph of without it in hand. Please provide referencing to specific dip of the San Luis Bay fault will be section, last sections of the report when they are available. assessed in Chapter 7 line Section Elsewhere "catalog" rather than "catalogue" is used. Line 790; This section has been removed from 150 5.4.1, p. 83, Please be consistent. Appendix F Chapter 5. This comment will be noted title during review of Appendix F Section The terminology for the areal zones does not seem to Figure The figure in question has been 5.4.1., page agree with Figure 5-20. In the latter, the innermost zone is removed removed from Chapter 5. This is 151 83, 1st labeled "Areal Source Zone," not "Local Source Zone. discussed in Chapter 13. The paragraph, Please clarify and intended distinction, or make them terminology has evolved; current is 1st consistent. "Local areal source zone" sentence: Section Consider adding a short phrase (or a specific reference to Chapter 13 This section has been removed from 5.4.1, page another section of the report) to define what is meant by Chapter 5. The comment is addressed 152 83, 1st "gridded seismicity rates." in Chapter 13 paragraph, Line 4, Section Please provide a reference to the report section where the Chapter 13 This section has been removed from 5.4.1, page cited sensitivity analyses are documented. Chapter 5. The comment is addressed 153 83, 1st in Chapter 13 paragraph of section, last sentence: Section Please specify that this is "structural" frequency (and not Chapter 13 This section has been removed from 5.4.1. p. 83. annual frequency). Chapter 5. The comment is addressed 154 1st in Chapter 13 paragraph, last sentence 155 Section If this is the first use of the acronym. please define it (it Appendix F This section has been removed from 5.4.1, page may be used freely thereafter, as it does appear in the Chapter 5. This comment will be COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location PPRP Comment Location Summary of Revisions to Report in Text1 in Text Comment for Number Comment Revision 83, 2nd acronym table). addressed in Appendix F paragraph of section, Line 2: Section It would be helpful for references to other parts of the Chapter 13 This section has been removed from 5.4.1, page report to be specific as to section number. Chapter 5. Chapter 13 provides all the 83, 2nd required information on seismicity rates 156 paragraph of in aerial sources so no internal section, first references are necessary. listed item, last line: Section To avoid confusion for the reader unfamiliar with the Line 811-814 Text modified as requested. Please 5.4.2, page region, you might consider noting parenthetically that, note that the subheading has been 157 84, 1st while similarly trending to the Los Osos, has an opposite removed, and this is now just Section paragraph of dip direction. 5.3. section, last sentence: Section The wording leaves the confusing initial impression that Line 815 Text modified as requested. 5.4.2, page the topic of the paragraph will continue to be the San 158 84, 2nd Simeon Earthquake rather than the Lompoc Earthquake paragraph. ("San Simeon" is the sentence subject, whereas "Lompoc" 1st appears in a prepositional phrase). Please consider sentence: rewording this. Section The meaning of "is considered in terms of' is not clear in Lines 831-838 Text modified as requested. 5.4.2. page this context. If you mean. for example, that the available 159 85, 2nd mission records (etc) place some bounds on the timing of paragraph of the most recent event (as the subsequent sentence section, Line indicates). please consider using some more direct 2, wording. Section The phrase" ... more northwesterly compared to the Lines 866-87 4 Text revised to clarify that although the 5.4.2. page more northwesterly ... "may have a typo in it. Please Hosgri focal mechanisms strike north-160 86, 1st check and correct or clarify. northwesterly, they strike "more sentence on northerly than the northwest-striking the paoe focal mechanisms directly east ... ". COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location PPRP Comment Location Summary of Revisions to Report in Text1 in Text Comment for Number Comment Revision Section 5.5, Please include in observation 2 a brief indication of how Lines 886-888 Text modified as requested. 161 page 86, 3rd the San Simeon Earthquake supports the transpressional line after the model (as you already do in the cases of observations 1, list: 3 and 4). Section 5.5, The sigma_1/d_3 could be confused for a ratio, so please Line 889 Text modified as requested. 162 page 86, 4th restate to remove the ambiguity. line after the list Section 5.5, What is the red star shown in panel (a) of the figure? Figure 5-25 Figure is simplified to show only one 163 p. 86, 2"d Consider re-sequencing the discussion here to be sketch of the transpressional shear paragraph consistent with panels (a) then (b) of the figure, or reverse tectonic model. Red star clearly labeled the panels in the fiQure. and in explanation as the DCPP site. Section 5.5, These paragraphs describe two models on the styles of Lines 893-918 Text is modified to provide more clarity Page 86,last active deformation in the DCPP region, but both appear to and distinction between the two two be essentially the same in that the Hardeback models. paragraphs transpression model shows pure shortening on the on page Oceanic, Los Osos, San Luis Bay, Casmalia and Lion's Heads faults (in her figure), but so does the NE-SW-164 directed crustal shortening model of Lettis et al. (1994, 2004). How these models are distinguished is not clearly presented. Please clarify. Presumably the transpression model includes lateral slip on some or all of these faults, but if so, please explain why the Los Osos fault in the OV model is RL oblique reverse. whereas the San Luis Bay. Casmalia and Lion's heads faults are believed to be LL oblique reverse to reverse. Figure 5-2 The model works until about 80 Ma, after which the slab Figure 5-2 is a schematic flattened due to subduction of buoyant crust, producing representation to show how rocks of the Laramide Orogeny. More relevant to DCPP is the the Franciscan and Great Valley 165 configuration that was frozen in place in the late sequence were deposited, and has not Oligocene I early Miocene, presumably with a relatively been modified. The text is modified to flat subducting slab. Please provide a discussion of this provide additional explanation and configuration. clarity of the Cenozoic plate configuration. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location PPRP Comment Location Summary of Revisions to Report in Text1 in Text Comment for Number Comment Revision Figure 5-18: The orientation of the various cross-sections is not clearly Figure 5-18 Note added to figure to hopefully clarify 166 explained in the figure or caption. tie between maps {a to c) and sections {d to f) Figure 5-21: Legends are very difficult to read, especially in panel (b). Figure 5-20 Figure modified as requested. 167 {note change in Figure# COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT PPRP COMMENTS AND Tl TEAM RESPONSES, INSTALLMENT #2

GENERAL COMMENT

S AND CHAPTER 6 Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision General Comments 259 Overall, the chapters that comprise Installment #2 are well written and Comment acknowledged. We have been working with a provide the necessary documentation for several elements of the SSC technical editor and are striving for consistent, specific model. As noted in Installment #1, the text would benefit from a internal referencing. comprehensive technical edit to ensure consistency in the usage of various terms, tense, third person, etc. Such an edit would also allow for more specific internal referencing to other sections of the report. Suggested edits are provided in these comments, but they are not exhaustive. 259 As noted in the PPRP comments for Installment #1, it is strongly We are committed to using the PG&E title block. Each recommended that figure captions be developed for every figure to assist figure has a title. Additional explanation (i.e., the the reader in understanding the salient points of each figure. Title blocks information that would be presented in captions for a and notes are helpful, but they often do not adequately convey the publication) will be presented in notes on the figure. The messages that the figure is intended to convey. notes can be elaborated into more explanatory descriptions where necessary. 260 Throughout the text, the terms "SSC" and "SSC model" are used Comment acknowledged: use of these terms will be interchangeably. Common usage would dictate that the elements of the checked throughout the report. SSC model should be indicated as such, and that the activity of characterizing seismic sources should be termed SSC. Editing the text for consistent usage is recommended. CHAPTER 6-Seismic Source Characterization Overview 261 Line 14 Please check whether "piecewise planar" would better convey the Lines 14 and 37 Edit made as suggested. intended meaning here and on Line 33. 262 Line 20 Please state, in some quantitative terms, the threshold to be considered to Lines 20-21 Defined approximately as contributing a few percent or "contribute significantly." more to total hazard at relevant frequencies and hazard levels. 263 Line 28 If this is the first usage in the report of the terms **maximum earthquake" Lines 30-32 This is first usage of terms. Definitions provided as and "floating earthquakes", please define or indicate the subsequent requested. section of chapter 6 in which the definition will be given (they are defined on Lines 177-179, for example). Otherwise provide a reference to the previous report section where they were defined. 264 Lines Please explain difference between seismogenic or potentially Lines 38 to 44 Potentially seismogenic distinction removed; 34-35 seismogenic. seismogenic fault is defined. 265 Line 36 Please provide more detail regarding sufficiently active. Presumably this Lines 38 to 44 The sentence in which the term 'sufficiently active' was relates to recurrence rates. used has been replaced by more detailed discussion of criteria used to idenitify seismogenic faults. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 266 Line 38 References to depth here, and in several other places in the chapter, are Revised to be 'depth extent' ambiguous. Please establish, in each case in which it matters, whether Line 61 the reference is to depth to top, depth to bottom, or some other quantity (e.g .. depth extent). 267 Lines Please consider rephrasing to the following -Key data from the DCPP Addressed in Chapter 11 comment 43-44 region are needed for fault slip rates and the lime since the most recent Chapter 11 earthquake 268 Line 46 Non-specific or non-specified? Line 70 Revised to non-specified 269 Lines Please cross reference where hazard sensitivity studies show that the Chapter 11 comment 53-55 SAF has only a small effect on hazard. 270 Line 62 Please provide a more specific reference (section number and figure Chapter 11 comment number(s)). 271 Line 63 "fault" should be plural Line 86 Text revised as suggested 272 Line 63 Please show/reference lngley site on a figure. Chapter 11 comment 273 Line 68 "Recent historical" seems redundant, especially for California as we have Line 91 "Recent" has been deleted such a short historical record. Are you implying there are "older historical" earthquakes? 274 Lines It is recognized that the conclusions presented in these paragraphs Chapter 11 comment 57-88 regarding recency, displacement per event, and recurrence intervals are summaries of the conclusions drawn elsewhere. However, the reader would benefit from specific references to the locations in the report andfor the primary references where the data have been evaluated and the conclusions and uncertainties have been developed. 275 Lines "Selected historical ruptures that we considered in developing both Fault Lines 101-102 Text revised as suggested 76-79 Geometry Models and rupture sources for these fault sources (discussed below in Sections 6.3.1and6.3.3, respectively) are listed in Table 6-1." Please move parenthetical phrase to end of sentence. This occurs many places in the text and ii would make the document flow better if they were at the end of the sentence where possible -see below 276 Table 6-One other well-studied earthquake to consider in this table is the 1999 Line 106 (Table The Hector Mine earthquakes has been added as an 1 Hector Mine earthquake, as it nucleated on a splay fault and then ruptured 6-1) analog earthquake to Table 6-1 bilaterally. It also produced secondary rupture on a number of small faults. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 277 Table 6-The source faults in the 2010 El Mayor-Cucapah rupture were not Table 6-1 (near This statement. which was taken from Fletcher et al., 1 previously unidentified, as stated. These were all mapped by Barnard as Line 107) has been modified to stress that the existence of an part of his PhD thesis, and have been shown in a number of published 'integrated' fault system was not previously recognized. sources. All were named faults prior to the earthquake. What was not Additionally, text was added to state that the fault known is how all of these faults work together to accommodate oblique system consists of seven 'previously mapped' major strain. faults 278 Lines Please flesh out this line of reasoning out-Chapter 11 comment 104-105 The founding of the mission at SLO in 1772 together with the lack of reported earthquakes in mission documents provides a rationale for settina Tmin=242 vr. 279 Line "Missions were sensitive to strong ground motions" Chapter 11 comment 107 Please expand. 280 Line Please consider rephrasing -Chapter 11 comment 118-120 In summary, the lack of any damage reports in documents from the San Luis Obispo mission make it unlikely an earthquake of M6.5 or larger on DCPP Primary and Connected faults since 1772. 281 Line Figures 6-2 through 6-7. Consider presenting Table 7-2. Primary and Line 165 Revised as suggested. Table 6-5 provides the codes. 131 Connected Fault Section Codes and Descriptions here in Chapter 6 where References in Figures 6-2 to 6-7 updated. figures are first presented. 282 Line Please provide a more specific reference, i.e., number of section and Line 171 Revision made to cite the preliminary sensitivity results 137 figure(s). where the relevant sensitivity studies are described. presented at Workshop 1 283 Line Please note the typo: should be Figure 6-7 (rather than 6.7). Line 206 Corrected as suggested. 17') 284 Line Figure 6-7. Should a rupture source S4+S5+S6+S9+S10 be listed? Figure 6-7 No change. The list on Figure 6-7 is not intended to be 174 exhaustive but sufficiently detailed to explain the conceot. 285 Line This is one example of the usage of "SSC" where "SSC model" is Line 214 Text revised as suggested 180 recommended. Please ensure proper terminology throughout the text. 286 Line Please remove is" Chapter 11 comment 185 287 Lines "over the forward-modeling rupture model approach taken for the Diablo Lines 238-239 Text revised as suggested 204-205 Canyon SSC model" Model seems to be over-used in this sentence .. 288 Line Please remove "wide" Chapter 11 comment 212 289 Line Would the Hosgri fault be considered low slip rate and "within the noise?" Lines 247-250 Text revised as suggested. 215 Might want to temper this a bit by clarifying that the DCPP SSC model needs to deal with lesser faults and detailed characteristics of Hosgri fault. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 290 Line Consider adding a sentence noting that a forward modeling approach Lines 283-286 Text modified as suggested. 246 does not imply that there are no overall constraints in the SSC model on such things as cumulative slip rate and deformation rate. Rather, it just means that those constraints are not formally imposed within the framework of an inverse modeling approach. 291 Line Please change displacement to displacements. Chapter 11 comment 248 292 Line PDF is used to indicate a probability density function. Line 303 Text revised as suggested 264 293 Line Please consider whether the meaning would be clearer if the passage Line 327-328 Text revised as suggested 289 were rewritten as "such that, when the contributions from all rupture sources that include a particular fault are summed.". 294 Lines Are the slip rates uniform over the entire rupture source for the main fault Lines 332-333 Text revised to clarify. 294-296 (larger slip rate) and uniform over the entire rupture source for the secondary fault (smaller slip rate)? Please explain. 295 Line Please give an indication of what magnitudes would be considered Lines 360-361 Text revised to add magnitude range. 321 '"moderate to large." 296 Lines The last line of the paragraph is unclear as to its meaning. "'the number of Line 369 Text revised to change the word 'distinguish' to *assess' 330-331 events captured is very few or is difficult to distinguish." The first part makes sense -the number of events is very few. The second part is unclear -the number of events is difficult to distinguish." Distinguish from what? To count? To determine? 297 Lines Long sentence. please consider breaking it up. Lines 372-373 Text revised as suggested. 332-338 298 Line '"understood to accurately model" -please change to -understood to Lines 378-379 No revision. Split infinitive judged to more clearly convey 340 model accurately the central idea of the sentence. 299 Line '"but few are sufficiently large to preclude throughgoing fault rupture." Lines 383-384 Text revised as suggested. 343-345 Please consider adding to end of sentence -based on observations from other segmented strike-slip fault systems (Wesnousky, 2006). 300 Line Please define '"behavioral." Line 385 Text revised to clarify that "behavioral' refers to size and 346 timing 301 Line Figure 11-8 should be Figure 11-9. Chapter 11 comment 350 302 Line Please note the typo: "'MDF" should be "'MFD". Line 398 Typo corrected. 358 303 Line '"by maximum rupture source size" would read better as '"by the maximum Line 401 Text revised. 361 rupture ... 304 Line It is not clear how this sentence relates to the previous sentence. Does Lines 402-403 Text revised to better relate the sentences. 361-362 the maximum rupture source size relate to the characteristic earthquake rupture dimensions? COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 305 Line Please consider expressing this differently. Do you mean that the absence Lines 403-406 Yes; Text revised accordingly. 363-364 of that information is not a rationale for precluding characteristic-model behavior as part of the technically defensible range of models? 306 Line Please consider using a more descriptive term such as "exponential MDF" Line 408 Text modified as suggested. 367 here, since another exponential distribution (i.e., for recurrence times in a Poisson process) comes into the discussion elsewhere in the report. 307 Lines Is this saying that faults and portions of fault networks that have been Line 416 Word also added to sentence to clarify that, in many 370-375 modeled with characteristic earthquakes can ALSO be modeled with cases, either characteristic earthquake or truncated exponential distributions? Or that faults and portions of fault networks that exponential magnitude PDFs are arguably consistent are modeled individually with characteristic earthquakes can be with data. represented in aggregate with exponential distributions? 308 Line What is an historical limit? Is this the observed maximum for the fault? For Lines 421-423 Text revised to clarify. 379 any fault of the same slip type? Please clarify. 309 Line Consider replacing accidently with coincidentally. Chapter 11 comment 379 310 Line "equally durable scrutiny" Please consider replacing with -much scrutiny Line 435 Text revised as suggested 393 311 Line Please consider whether there is a published article or report that could Line 438 Text revised to cite Table 6-1 (several citations) in 396 be cited instead of the unpublished powerpoint presentation addition to Hardebeck presentation. 312 Line Please provide the justification for the sole selection of this relationship in Lines 453-463 Text revised to better explain rationale for the sole use 410-413 light of these issues. For example, why is this relationship preferred in of the Hanks and Bakun relationship. light of the "dimensions and style of faulting"? the tectonic setting? The "application of magnitudes in the PSHA"? 313 Line Please consider whether "end-member" is the optimal characterization of Line 464 Text revised to eliminate the 'end-member' terminology. 414 the set of proposed magnitude PDFs (i.e., what distribution are they end members of? Does that distribution have four endpoints?), or whether instead the set actually includes samples from throughout the distribution of proponent models. 314 Line Please delete the citation of an article that is "in preparation," or update Line 472 Text revised to cite Appendix G, which includes the draft 420 the citation to a published article. If that manuscript is unpublished but WAACY manuscript contains elements essential to this report, please include those elements in Appendix W AACY. 315 Line Please provide the rationale for the selection of these magnitude PDFs for Lines 479-480 The text has been revised to provide a cross reference 426 each rupture source type. Also, please provide the justification for the to Section t 0.2.3 for discussion of the rationale for branch weights cited here, or provide a reference to the report section selection and weighting of the various magnitude PDFs where that justification is given. for each rupture source type. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 316 Line 6.3.6 Time Dependency Model. Please consider moving this section up in Line 482 No change. 428 the chapter so that the sections mirror the order of the logic tree shown in It was noted in the initial discussion of the logic tree (see Figure 6-1: Time Dependency Model, FGM, Rupture model, Slip rate Lines 127-133) that the order of the logic tree is Allocation model, MOM organized to facilitate the implementation in the hazard code (i.e., global parameters that apply to all or a group of sources are listed first) followed by more specific assessments that pertain to individual sources. Terminology explained in the preceding sections is used in the discussion of the Time Dependency Model. Therefore the Tl Team feels that moving this section forward is not warranted. 317 Line Suggest clarifying that the theory relates to individual faults. PSHA began Line 491 Text revised as suggested 435-437 with the representation of seismic sources as zones that likely included multiple faults and. as a result. these behave more like a Poisson process. 318 Line This line refers to "coefficient of variation in the long-term mean rate." That Line 497 Text corrected to state, coefficient of variation in the 443 would be an epistemic uncertainty. However. please check whether that is recurrence model" the actual intent on this line, or whether the intended reference is to the coefficient of variation in the recurrence model (and which represents aleatory variability in recurrence time associated with a given long-term mean rate)? 319 Line What is meant by a "global parameter?" Lines 502-503 Text revised to include explanation. 448 320 Line "many tens of active faults". Please consider removing -tens of Line 506 Text revised as suggested. 452 321 Line Please replace "to" with " do" Chapter 11 comment 453 322 Line Please give a more specific reference to the sensitivity analyses that Lines 509-512 Text revised to clarify where results of sensitivity 456 support this statement about the hazard contribution from regional analyses were presented or described. sources (i.e .. by citing section number(s) and figure or table number(s) where the relevant analyses are presented). 323 Line "included as a fault sources". Either drop the "a" or change sources to Line 523 Text revised to drop the 'a' 466 singular. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 324 Line Why is a conservative characterization used? How do you know that it is Lines 538-540 Text revised; adjective describing the characterization 466-467 conservative? removed, and discussion of justification of rates used moved to Chapter 12. 325 Line Please indicate who is doing the judging in this and the next sentence. Lines 531-534 Text revised to specify that these are Tl Team 475 judgments. 326 Line Please explain what is meant by a point source" in this context. Text revised -set of point sources on regularly spaced 508 grid. Cross reference provided to Sections 13.3, 13.4 327 Figure Please replace loger with longer. Figure 6-1 Figure corrected 6-1 caption ATTACHMENT PPRP COMMENTS ON DCPP SSC DRAFT REPORT PPRP COMMENTS AND Tl TEAM RESPONSES,

GENERAL COMMENT

S AND CHAPTER 7 Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision General Comments 259 Overall, the chapters that comprise Installment #2 are well written and A technical edit has been performed provide the necessary documentation for several elements of the SSC model. As noted in Installment #1, the text would benefit from a comprehensive technical edit to ensure consistency in the usage of various terms, tense, third person, etc. Such an edit would also allow for more specific internal referencing to other sections of the report. Suggested edits are provided in these comments, but they are not exhaustive. 259 As noted in the PPRP comments for Installment #1, it is strongly We are committed to using the PG&E title block. Each recommended that figure captions be developed for every figure to assist figure has a title. Where appropriate. additional the reader in understanding the salient points of each figure. Title blocks explanatory notes have been added. and notes are helpful, but they often do not adequately convey the messages that the figure is intended to convey. 260 Throughout the text. the terms SSC" and SSC model" are used Usage of the acronym SSC has been standardized to interchangeably. Common usage would dictate that the elements of the strictly mean "seismic source characterization". SSC model should be indicated as such, and that the activity of characterizing seismic sources should be termed SSC. Editing the text for consistent usage is recommended. CHAPTER 7 -Fault Geometry Models 328 General Please make references to other parts of the report as specific as possible, Cross references have been checked and more specific i.e., by providing section number(s), and figure or table number(s) where subsections added where appropriate appropriate. Some instances where this is required are noted in specific comments. but please review the chapter for other instances and make appropriate changes. 329 Line 5-6 Common usage would call this a seismic source characterization model." Line 5 Text revised to add *model' as suggested. 330 Line 10 Figures 6-2 to 6-5 are maps showing Primary and connected fault sections Figures 6-5 and 6-6 are regional figures that show the not "Figures 6-5 to 6-6" as listed No change full extent of all of the Primary and Connected fault needed sections. 331 Line 18 Suggest making reference to the logic tree that shows these alternatives Text revised as suggested. and weights. Line 18 Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 332 Line 81 Please provide a more specific reference to the section(s) of Chapter 13 A discussion of seismogenic depth is not included in where the discussion cited here is presented. Chapter 13. More detail is provided here regarding the Lines 81-92 subset of the Hardebeck 2014 catalog used to calculate 090 and 095. and the resulting depths. 333 Line 83-84 Please provide a more specific reference to the section(s) of Chapter 14 Text revised to cite Workshop 1 sensitivity results that substantiate the claim made on these lines. Line 93 334 Line 96-97 You may also want to cite the deepening of seismicity after the 1999 lzmit Text revised to cite Ben-Zion and Lyakhovsky, 2006) earthquake. Seismicity deepened by-3 km, and recover over the following Line 109-112 modeling results that show transient deepening of 6 months (BenZion et al) aftershocks following a main shock. 335 Line 107-113 Please provide references to articles or the report section(s) that present Instead of referencing other parts of the report, the the observations and interpretation cited here. Lines 121-146 observations and interpretations that bear on the depth to the top of rupture are summarized here in this section. 336 Line118 Terminology is odd. Suggest changing "allowed to" to "assessed to." Text revised as suggested. Line 151 337 Line 131 Are these spatial patterns of epicenters and hypocenters? Does this Text revised to clarify include focal mechanisms and their associated geometries? 165-167 338 Plate 7-1 Plate 7-1. Why are the names of rivers and creeks highlighted by blue boxes? Please remove blue boxes around names of rivers and creeks. This appears to have been a problem with the pdf No change download. The final version does not show blue boxes needed around names of drainages. 339 Line 164 The wording on this line is ambiguous. Please rephrase this passage to Text revised to clarify. clarify whether it is the simplified representations" or the "actual faults" that Line 201-202 are shown in the cited figures. 340 Line 172 Please specify by whom it is considered to be insufficiently wide to be a Text revised to provide reference to Wesnousky (2008) barrier, and on what basis. Unclear what is meant by universal" in this and to clarify that the Tl Team assesses this complexity to context. It sounds like the Team made an assessment that the basin is not be useful for defining rupture sources and MFOs, but sufficiently wide to represent a barrier to ANY future ruptures? Lines 210-217 does not consider it sufficiently pronounced to prohibit 'oint rupture of the onshore and offshore Los Osos fault. 341 Line 174 "single fault connected fault source" The first "fault" could be deleted Agreed. Text revised to eliminate the first 'fault'. without losing anything. Line 218 342 Table 7-2 In reference to the Wilmar Avenue fault. it would be best to spell out Agreed. Table text revised accordingly. "Avenue" as it is a proper name. Table6-5 Please note that the table has been moved into Chapter 6. Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 343 Lines 188-Please consider rephrasing to the following Text revised for clarification 190 Two boundaries between fault sections that are not intersections between Lines 229-232 Primary or Connected fault sources are discussed below. 344 Line 217 Please specify by whom (e.g., the Tl Team) such geometries are assessed Text modified as follows: to be the only valid ones, and consider whether the intent of this line would Fault geometries for the Primary and Connected fault be better conveyed by the phrase "technically defensible" in place of sources were considered by the Tl Team to be "technically valid. permissible only if slip on the faults will produce this general pattern of vertical deformation. The Tl Team recognizes that other mapped faults (and possibly other Lines 256-263 blind faults) in the SLPB area may be capable of producing moderate to large earthquakes. However. the Tl Team judges that the slip rates of these other faults must be sufficiently low so as not to affect the observed uplift rate pattern. This category of other possible faults are considered as part of the areal source zones in the Diablo Canyon SSC model (Section 6.5 and Chapter 13). 345 Line 218 Please explain in the caption of Figure 7-4 the meaning of the additional The caption is expanded to define these interpretations of annotations such as "<0.05 m/kyr," that appear away from the dashed approximate uplift rates. contour curves (e.g., are these point constraints based on specific Figure 7-4 observations; or are they regional generalizations, and, if so, how wide an area do they apply to?). 346 Lines 242-Please provide a reference to the specific report section(s) where this Reference to Section 13.5.2 added. 246 assessment is justified. Lines 291-293 347 Line 245 "convincing evidence of unique fault geometry". Please consider changing Text revised as suggested. "of unique" to -for well defined Line 292 348 Line 292 Please define the rake ranges that distinguish the "reverse" sense of slip Text revised to clarify that the lateral component of slip from the "reverse oblique" sense of slip, since this distinction was not given varies among the three models, but is always secondary on Lines 259-264. Lines 338-342. to the reverse component. Because they use the same GMC models, the precise boundary between reverse and reverse oblique is not meaningful. 349 Line 307 A comma is required after "bathymetry data" for clarity Line 353 Text revised as suggested. 350 Line 308 Figure 7-5 is a good example of how figure captions would greatly help the Per general request, figures have been reviewed and reader interpret the panels of the figure. Figure 7-5 and explanatory text added where needed. others 351 Line 309 "DCPP that were compared to evaluate". Please consider replacing Text revised as suggested. "compared" with -examined Line 355 352 Line 338 "The HFZ is the best imaged, most continuous, and complex fault zone" Text revised to delete *complex* "complex" -scale dependent. thus level of complexity is dependent on imaging resolution -some of the faults in the Irish Hills could be equally or Line 384 more complex than the H FZ?? Please clarify. Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 353 Lines 341-"Locally, strands of the fault zone exhibit seafloor expression. either as Text revised to clarify that the fault-line erosional features 343 erosional fault-line scarps. or possibly also as tectonic scarps within young are generally observed in bedrock in contrast to scarps in sediment." Lines 387-390 young sediment inferred to represent youthful tectonic surface rupture. Please expand to explain differences between the two. 354 Line 343 Some explanation is needed either here andlor as a figure caption Caption added explaining what the ages of the MIS tracts and unconformities are in the Figure 7-6 figure. 355 Lines 351-Please explain how "aleatory uncertainty" can be captured by modeling Revised text to change 'uncertainty' to 'variability' and 352 "alternative near-surface traces." That is, doesn't the word "alternative" deleted the word 'alternative'. The point of this discussion imply epistemic uncertainty. and that the options for the trace location are is to describe aleatory variability. All three surface traces mutually exclusive (and isn't that the thrust of the discussion on Lines 390-have ruptured in the Quaternary and will likely rupture 404), which would preclude them acting in concert to produce aleatory Lines 399-400 again. variability? In contrast, the alternatives discussed in lines 390-404 (now 456-476) describe alternative (and mutually exclusive) interpretations of the down-dip geometry of the three surface traces. 356 Line 356 Please check whether there is a peer-reviewed report or article The 2012 citation is the Workshop 2 presentation and a documenting the study of Hardebeck cited on this line. and if there is, comma has been added to clarify that. The 2013 please cite that in preference to the unpublished Workshop 2 presentation. reference is a published paper. The Tl Team considers Line 405 citing both to be appropriate to indicate that the information was presented as part of the SSHAC Level 3 process and also confirmed by later publication. 357 Line 363 Please consider replacing "apparently" to -interpreted to be Line 416 Text revised as suggested. 358 Line 369 Consider replacing "and also" with "along with" Text revised to delete the phrase 'and also' and which 423 catalogs were used. 359 Line 376 The seismicity is projected onto a plane that is perpendicular to the strike of Text modified to clarify that seismicity is projected onto a the Hosgri fault. Also, it is very difficult to see the plus signs and dots on Figure 7-9 and plane perpendicular to the strike of the Hosgri fault. the figure. Can they be enlarged? Line 431 Plus signs are enlarged to distinguish them from dots. Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 360 Lines 379-Please explain the basis for the proposed associations of hypocenters to The text has been modified to provide further explanation 382 faults. and note any other analyses that were undertaken to try to resolve of how the seismicity was separated spatially, and provide the apparent ambiguity in those associations (as seen in Figure 7-9). For citation to the analyses considered in this separation. example, can the association of hypocenters to the Hosgri fault be improved by restricting the cross-sectional projection to events located The figure is also modified to incorporate more southeast of DCPP (avoiding interference from the northernmost part of the hypocenters into the category of uncertain association. Shoreline Fault and Estero Bay seismicity)? The Tl Team also considered the following analyses, but did not include them in this figure (or Figure 7-10) Lines 434-445 because they were judged to be less informative regarding the fault dip along the reach adjacent to the DCPP, or impractical to include in a static image: . Classification by Hardebeck (2013) of first motion polarities that are consistent with either Hosgri or Shoreline fault orientations, . Projection of narrower window within the San Luis Bay reach of the fault. . Visualization of hypocenters and focal mechanisms in 30 space. 361 Line 382 According to the legend. the plus symbols represent "uncertain Legend was updated to state 'intermediate location' association." Figure 7-9 consistent with the text. 362 Line 393 Please explain in what sense model H85 is the best fit to the seismicity. Text revised to note that the H85 provides a reasonable fit to the seismicity data and that it is most consistent with Lines 459-463 Hardebeck (2010. 2013) tomoDD focal mechanism OADC mean planar solution. 363 Line 398 Figure 7-11 indicates "systematic offset which could be better defined as Figure is updated as recommended. Discussion of possible systematic offset of hypocenter locations from the fault. Also, Figure 7-11 and "possible future data" is moved from the figure into the "possible future data" is cited in the figure text but is not discussed in the Line 468-470 text text. 364 Lines 400-"The H90 model fits the seismicity data, but is less consistent with fold The text is updated to cite the interpretation from 401 deformation that appears to indicate a flower structure on the reach Willingham et al. (2013) that the fault dips steeply to the adjacent to the DCPP. " Lines 474-477 east, and that the Hosgri fault is typically expressed as a There are many fault segments offshore, could the fold deformation and flower structure instead of parallel faults that do not flower structures be explained by constraining bends along a vertical strike-merge. slip fault -H90? 365 Line 452 "North" Please replace with -Northwest Line 534 Text revised as suggested. 366 Lines 464-"The concept of the outward-vergent (OV) model is that uplift of the SLPB The pattern of uplift inferred by the connection off the 466 is produced by transpressional right-reverse faulting along the northeastern Shoreline fault to the San Luis Bay fault is described in and southwestern block boundaries (Figure 7-13)." paragraph 5 of this section Please explainfdiscuss. The Shoreline is a vertical strike-slip fault. Reverse Lines 608-61 3 slip is occurring toward the southeast on BE, WA and OF fault segments. Such a configuration would predict uplift rates to increase toward the southeast-in contrast to the observations? Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 367 Line 469 Figure 7-14. Please discuss constraints on Los Osos dip from segment LE Additional explanation has been added to the introduction (80') to LO (60') of fault models, Section 7.4. to emphasize that very few definitive constraints are available on the dip of faults beneath the San Luis Range. To account for that, our approach is to interpret that uplift of the range is driven by Note added to fault slip. The SSC model includes a range of fault dips Figure 7-15. such that the entire uplifting range overlies at least one Lines 542-548 dipping fault plane. The difference in dip is explained by and 601-603 the difference in the width of the uplifting range. A second reason for the steep dip of LE is a speculative link to the Edna fault within the Irish Hills shown on Figure 7-17. Please note. Figure 7-14 has been renumbered to Figure 7-15 368 Lines 475-Junction with dextral-reverse Oceanic-West Huasna fault is not shown in Text revised to cite Plate 7-1, which does show 476 Figure 7-13 Line 576 intersection. 369 Line 476 Figure 7-13. Please discuss intersection of OF and SF -does the reverse No change to Reverse deformation west of the Shoreline fault is slip die toward the northwest? Why is there no reverse motion along text of Chapter interpreted as distributed deformation. This is discussed segment SF? 7 in Section 8.4. 370 Line 488 If the phrase *'seismic source zone" on this line means the same thing that Text revised to use consistent term -Local areal source "areal source zone" or Local Source Zone" means in Chapter 6, please zone use the appropriate one of those previously defined terms to provide a Line 589 consistent terminology throughout the report. If is means something else, olease define it. 371 Line 494 Please explain further the kinematics between shoreline fault and San Luis Uplift in the hanging wall of the San Luis Bay fault west of Bay fault in transect C-C' the Shoreline fault is interpreted to be caused by one of Lines 608-613 three factors: additional faults in the SWBZ, distributed deformation up-dip of the San Luis Bay fault, or a restraining bend in the Hosgri fault 372 Line 497 Figure 7-16. Why does ancestral Shoreline Fault have a dip? Please Figure replaced with an unrestored cross section, and the explain relationship with vertical Shoreline Fault. Figure 7-17 number is changed to 7 -17. 373 Line 497 Figure 7-16 legend states faults are solid where well located -Are Edna C Figure replaced with an unrestored cross section, and the and Los Osos faults well located down to -30,000 feet? Figure 7-17 number is changed to 7 -17. 374 Line 497 Figure 7-16. Please discuss constraints on dip between the range-The cross section shown in the figure (now 7-17) was bounding reverse faults and steeper strike-slip faults within the range for developed by PG&E. 2014, Chapter 7 based on the structural model shown in Figure 7-16 as well as uncertainties. Figure 7-17 interpretation of surficial geologic mapping, seismic-reflection data, and correlation to borings and wells. A note has been added to the figure stating this. 375 Line 508 Presumably, the sensitivity analyses only include a range of depths that are This paragraph has been moved to the section on depth considered to be credible. Other values could have an impact on the to top of rupture. hazard. Consider adding the phrase, " ... not a hazard-sensitive parameter Lines 142-t46 Instead of citing sensitivity analyses, the text is revised to given the range of technically-defensible depths." describe the the Tl Team judges that a simplification of using a single value of 1 km depth to represent a range of 0-2 km is justified. Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 376 Line 511-513 This sentence is confusing. Perhaps it could be broken into parts or set off Line 606 This sentence is not necessary in Chapter 7, so it was with commas. deleted. Uplift rates are covered in Section 8.2.2. 377 Line 515 "in" is repeated -please delete one. Lines 128-133 The pertinent text has been modified and moved. 378 Line 530 Please place a comma between "formations" and "which" for clarity. Text revised to change 'which' to that to indicate that the Line 620 following phrase is a key conclusion--not just an optional descriptor. No comma is needed after 'that'. 379 Lines 531-"Uplift of the continental shelf region west of the Shoreline fault as indicated The ages of the submerged marine terraces on the 532 by the presence of submerged marine terraces " continental shelf west of the Irish Hills are characterized Lines 608-610 in Section 8.4. What is germane to Chapter 7 is that the Please provide any age information (e.g., MIS3?) shelf in that region is uplifting in that region. The text is modified to reference the original work (PG&E. 20t 1, Appendix I) 380 Line 536 Please explain further how the kinematics in the Southwest Boundary Zone Uplift of the Irish Hills is driven by slip on the San Luis to the northwest of segments BR and BE engender the uplift rates and Bay fault. West of the Shoreline fault, uplift of the patterns shown in figure 7-4. continental shelf occurs as distributed deformation up-dip Lines 608-616 of the San Luis Bay fault. It is not clear whether this deformation is driven by a seismogenic fault (as in the SW model) or is more distributed, and therefore better modeled as an areal source zone (as in the NE and OV models). 381 Line 538 If the phrase "local seismic source zone" on this line means the same thing Text revised to be consistent with term 'Local areal that "areal source zone" or "Local Source Zone" means in Chapter 6, source zone* as described in Section 13.5. please use the appropriate one of those previously defined terms to Lines 615-616 provide a consistent terminology throughout the report. If is means something else. please define it. 382 Line 540-541 Please discuss the constraints on the Wilmar Avenue fault being rooted There are no good constraints on the dip of the Wilmar into the steeper Los Osos East (LE) fault. Avenue fault at depth. The OV FGM allows for a relatively No change to steeply dipping fault that could intersect the Edna fault at text depth. The Tl Team judges this to be a technically defensible interpretation given the overall width of the range. 383 Lines 542-How well are the fault intersections at depth known? Is it important to There is little available data to constrain the geometry of 543 GMC? Please provide any insights possible. faults within the Southwestern Boundary zone al depth. The alternative FGMs are used to capture what the Tl Team judges to be a technically defensible set of alternative dips and depths of intersection of faults beneath the San Luis Range. Text was added in the introductory text of Section 7.4 to note the lack of Lines 542-560 available data that could be constrain these fault intersections. In order to capture the range of technically defensible interpretations. the Primary faults that are the main drivers of uplift in each model (e.g., the San Luis Bay fault in the SW Model and the Los Osos fault in the NE model) have been modeled to extend to the full seismogenic depth. and are not considered to be truncated by otherfaults Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 384 Line 543 A comma between "fault" and "assuming" would make this line clearer. Line 626 Text revised as suggested. 385 Line 567 Please check the caption of Figure 7-17a. On the third line of the caption, Caption revised as suggested. Note that the figure has shouldn't sinestral transpression" be changed to sinistral transtension"? been moved to 7-18. Also please mention in the caption of Figure 7-17b the reference number Figure 7-18 for the transpressional reverse splay feature that is noted there. 386 Line 568 Figure 7-18. Southward dipping fault that intersects the Shoreline Fault at This figure has been deleted. depth is Dashed in Figure 7-18 and solid in Figure 7-16. Please make Figure deleted consistent. 387 Lines 622-Why does the SLB fault increase to 50' on cross section D -D'? Any As noted in the text added in introductory part of Section 623 constraints? 7.4, the dip of the fault inferred to accommodate uplift of Figure 7-23 the range may vary along strike depending on the width of the range. The uplifting range is narrower along cross Lines 542-548 section D-D* compared to cross sections B-B* and C-C'. A note was added to the figure to indicate this. 388 Lines 641-"The Los Osos East fault (LE) is characterized as an axial surface that dips We have chosen to honor our approach of modeling the 642 steeply to the southwest. " primary faults to a depth of 12 km more strictly than our approach of restricting the spatial limits of the fault planes In panel B-B', the Los Osos axial surface is not controlled by the change in to approximate the scale of the uplifting range. A note dip of the controlling detachment and intersection of the San Luis Bay fault has been added to Figure 7-22 explaining that we -please explain location and driver of the "zone of deformation" for the Los recognize that the geometry of the Los Osos fault Osos axial surface. Figure 7-22 intersection with the San Luis Bay fault in panel b (Section B-B') does not clearly fit the expected geometry of an axial surface with a change in dip of the underlying reverse fault. The geometry of the San Luis Bay fault has been simplified to better represent an end member model as a moderately dipping fault (45°) that extends to a seismogenic depth of 12 km. 389 Line 642 The terminology "fold hinge" is used in the figure, but "axial surface" is used Figures 7-21 The figures have been updated to read "axial surface" in the text. Please clarify. through 7-23 and 7-25 through 7-27 390 Line 657 This would read more clearly as "San Luis Bay, Wilmar Avenue and The most significant potential lateral ramp would be Oceano faults). There is also an extra comma at the end, but inside the between the SLBF and the faults underlying the Edna parentheses. Lines 741-743 sub-block (the WAF and OF). The text has been revised to clarify and to correct typo as suggested. 391 Line 668 Should this be fold" axis? Lines 710-712 Text revised to read axial surface or backthrust 392 Line 682 Should "OV" model be SW model? Lines 763-764 Yes. Text revised to correct. 393 Line 684-689 This sentence is too long and could be improved for clarity. Lines 765-772 Text revised to break the sentence up for clarity. Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 394 Lines 729-Please move lines 773 -776 right after 734 so the reader knows why the Text revised as suggested. 734 dips of the faults are different for the Edna block in A-A* in Figure 7-22 and Lines 819-822 Figure 7-26. 395 Line 747 Granularity? Do you mean resolution? Regional constraints? Please Text revised to use the term 'sufficient coverage' clarify. Line 835 396 Line 752 "The dip of the Los Osos fault is shown as 500 throughout the entire The cross sections are corrected to show the Los Osos seismogenic crust beneath the Irish Hills." Figures 7-26 fault consistently with a 50 degree dip. II is shown as 60" in profile B-B' in Figure 7-26. and 7-27 397 Line 780-781 Sierra Pampeanas is the Spanish spelling, Pampean Ranges is the English Text revised to use consistent terminology. spelling -you have mixed the two. Please choose one. Line 866 398 Line 797-802 This statement is not germane to DCPP and is an incorrect interpretation. Agreed. Text from lines 807-812, and the note about They based this on a leveling line at the south end of the range where shortening rate in the following sentence were deleted. topography is actually low, and then apply the 1977 observed deformation Line 882 to the highest part of the range. This results in a shortening rate that is an order of magnitude higher than actually exists. It would be preferable to delete this sentence as it adds nothing. 399 Line 824 This 1st sentence would read better if a couple words were added: Agreed. We made the recommended changes. " ... subsequently been reactivated in the contemporary tectonic setting as _g Line 903 transpressional system." 400 Lines 834-Uplift patterns in the SW portion of the Irish Hills (Figure 7-4) northwest of Text revised to discuss how th is region of uplift is handled 837 segments BR and BE (Figure 7-13) are difficult to explain in the OV model Lines 915-924 in the OV Model. -please expand the section to clarify the uplift boundary. 401 Figure 7-20 The massif names are lh Bogd and Baga Bogd (Big Bogd and Little Bogd). Figure modified as requested. This spelling is different than in the text (see line 584). which uses the correct spelling. Please correct this figure to be consistent with the text. Figure 7-20 COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT PPRP COMMENTS AND Tl TEAM RESPONSES, CHAPTER 8 Location in Comment Location in PPRP Comment Text for Summary of Revisions to Report Number Text1 Comment Revision Chapter 8 Section 8.2, Please reference the section (and table or figure number Lines 18-19 Reference to appropriate Section has page 94. 1st if appropriate) where this sensitivity analysis is been added. 168 paragraph, documented. 2nd to last sentence: Section 8.2, Please replace "initial" with "completed" or just delete. Line 18 The word' initial' has been deleted. page 94. 1st 169 paragraph, 2 lines up from bottom Section 8.2, Please explain why the assertion here that the No change No change to text. page 94, 3rd environment is one of transpression doesn't contradict the paragraph of approach introduced in Section 5.5 of considering both The transpressional setting of the section, 1st transpressional and NE-SW crustal shortening models of Hosgri fault, particularly along its reach sentence: active deformation. adjacent to the DCPP, is largely inferred from the orientation of the fault within the present tectonic stress regime and evidence for a small component of 170 vertical slip indicated by positive flower structures and up-to-the east vertical offsets of the ELP unconformity. The two 'end member' models described in Section 5.4 are primarily addressing more regional conditions within the Los Osos Domain to the east of the Hosgri fault 1 Unless otherwise indicated, paragraphs identified are for the section, rather than on the page cited. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location in PPRP Comment Text for Summary of Revisions to Report Number Text1 Comment Revision Section 8.2, Please indicate whether the transpressional strain Lines 36-39 The following text has been added: Page 94, referred to here is dextral or sinistral, and how these paragraph 3 might change as the fault systems trend to the east and Within this strain regime, faults that line 3/4 become more easterly in strike. strike northwest are favorably oriented 171 to accommodate dextral slip, and more easterly-striking faults (approximately perpendicular to the direction of maximum compression) are favorably oriented to accommodate reverse slip (Fiqure 5-12). Section 8.2, Note that this is a sentence fragment. Please rewrite. Line 41 Corrected typo; sentence fragment page 94, 3rd should have been included with 172 paragraph of preceding sentence. section, last 2 lines on page: Section 8.2, If this is the first occurrence of this fault name, please Line 65 Definition of acronym added. page 95, define its acronym at this point. 173 2nd to last paragraph of section, Line 4 Section 8.2, : Please note the typo: CDF means "cumulative Line 69 Corrected page 95, distribution function" {not "continuous"). 174 last paragraph of section. line 2 Section This presentation of new models would benefit from a Note: Chapter has been reorganized to 8.2.1, Page more complete discussion of the older models. Lines 160-make Geologic Slip Rate CDFs Section 95 188 8.2.1 and Quaternary Uplift Rate 175 (Section 8.2.2). The text has been modified to summarize key observations and COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location in PPRP Comment Text for Summary of Revisions to Report Number Text1 Comment Revision conclusions of older models. Section "Are judged" by whom? Please specify. If this is to be Line 215 Text has been modified to clarify that 8.2.1.1, presented as a judgment by the Tl Team on the basis of this is a judgment of the Tl T earn page 96, 3rd the comment made about hydro-isostatic adjustment, Lines 225-176 bulleted please say so, otherwise cite reference. 229 Note that the discussion of uplift rate item: PDFs for the Irish Hills block (and associated figures 8-5 and 8-6} have been moved forward from previous location in Section 8.5) Section The bimodal ages from Point Loma are not on the lowest Line 242; The text has been clarified to note that 8.2.1.2, terrace, they are from the 2nd emergent terrace, the Lines 247-the bimodal ages are from the Nestor Page 97, Nestor terrace. Please correct. Also, the last line states 252 terrace. A statement also has been 177 Paragraph 1 that unlike San Nicholas Island, Point Loma and Cayucos added to note that remnants of a slightly do not have fragments of the older -120 ka terrace at higher terrace are present, but are slightly higher elevation Actually, there is a slightly correlated to MIS 7 by Kern and higher terrace in the San Diego sequence but it is inferred Rockwell (1992) to be the MIS 7 terrace (Kern and Rockwell, 1992). Section It is difficult to follow the logic in this paragraph -is the Lines 253-Text has been added to clarify age 8.2.1.2, preferred interpretation that the 13 m terrace at Cayucos 293 preference (MIS Se} for the 13 +/- 1 m 178 page 97, 4th formed during MIS Se? Please clarify. terrace. paragraph Section Figure is incorrectly labeled "San Nicolas Island. Figure 8-9 Figure title changed to 179 8.2.1.2 Figure 8.2. 1-Marine Terrace Observations, Ellysly 5 Creek Section Mentions a flight of 4-5 possible marine terraces, but lists Lines 295-The text has been modified as follows 8.2.1.3. the elevations of only 4 terraces. Please clarify. 297 Page 98, Recent work identified remnants of 180 paragraph 1. surfaces underlain by marine deposits line 1 within the Edna Valley (PG&E, 2013b). Terrace remnants are mapped at elevations of 40 m, 55 m. 70 m. and 80 m. 181 Section Refers to a personal communication from John Caskey. Lines 299-The discussion has been modified to COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location in PPRP Comment Text for Summary of Revisions to Report Number Text1 Comment Revision 8.2.1.3, The discussion appears to be quite speculative and need 316 reference only the observations in the Page 98, additional support. PG&E (2013b) report and those paragraph 2, presented more clearly in this report. It line2 is acknowledged that the inference regarding correlation to the late Pliocene warm interval (-3.3 -3.0 Ma, paleosea level of-22 m (+/- 10 m) is speculative Section "strongly developed soil" -is this documented? What are Lines 368-A description of the soil profile 8.2.1.3, its characteristics? Please provide a reference 385 described by Chea and Caskey and 182 Page 98, clay profile based on laboratory paragraph 3, Attachment analyses has been added to support the line 11 E-4 of Tl Team assessment regarding the age Appendix E of the Memorial Park terrace. Section "pedimentation" is the wrong word here. Pediments form Line 343 Agreed. Text modified accordingly to 8.2.1.3, in regions of vertical tectonic stability over long periods of replace 'pedimentation' with 'lateral Page 99, time. In this case, a flat surface can only result from fluvial erosion' 183 paragraph 4, marine planation of fluvial planation, neither of which line2 would be considered pedimentation in this context. Please consider replacing "pedimentation" with "lateral fluvial erosion". Section There seems to be a lot of conjecture in this paragraph, Lines 317-The discussion of the geomorphology, 8.2.1.3, most of which is not well documented except as a 392 stratigraphy, and soil profile Page 99, personal communication. Please provide better development has been expanded to paragraph 4. documentation. explain and defend the statements in this better document and support the 184 paragraph, and include references. For instance, "it is estimated age of the Memorial Park unlikely that the Memorial Park terrace surface is younger surface. than about 400 ka" -please provide better documentation and discussion on this key age parameter, as it implies very low rates of uplift of Los Osos Valley. Section Should this be equation 5.1. There are other "equation Line 76 Text modified to label this equation as 185 8.2.2, Page (1 )"usages in the report (c.f. page 133) 8-1 following the overall numbering 99, equation system for equations in this report--( 1) numbered sequentially by Chapter. 186 Section Is there a parentheses missing here? No change No--parentheses appear to be COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location in PPRP Comment Text for Summary of Revisions to Report Number Text1 Comment Revision 8.2.2, Page appropriate. 99, paragraph 3, line4 Section The abbreviation CDF means "cumulative distribution Line 102 Text has been corrected to ref er to 8.2.2, page function" (not "continuous" distribution function, nor 'cumulative distribution function' 187 100, 3rd cumulative "density" function). If you intend to say paragraph, "cumulative distribution function" (as appears to be the Line 4: case from the context), please reword appropriately. Section Please be clear about how the CDFs may be combined Lines 105-The text has been modified to clarify 8.2.2, page (for example, perhaps you mean by forming a weighted 110 that PDFs are combined different ways 100, 3rd sum with weights summing to 1.0?), or reference the for different types of uncertainty. For 188 paragraph, report section where that explanation is given. PDFs describing uncertainty in parts of Line 8 the total offsets, offsets are summed using Monte Carlo methods. For PDFs describing epistemic uncertainty in a value, the PDFs are weiQhted. Section Please replace "correct" with robust or has high Line 130 The term 'correct' was replaced by 8.2.2, p. confidence. 'robust' as suggested. 189 100, 5th paragraph, 5 lines down Section If there is not a single correct (but unknown) slip rate for a Lines 135-The text has been modified to clarify 8.2.2, p. given section of a fault, then there must be some 136 that slip rate CDFs represent epistemic 100, 5th variability in slip rate along that section. Typically, the slip Lines 146-uncertainty in the actual slip rate of the paragraph, rate CDF would be assumed to represent epistemic 149 fault. They do not incorporate aleatory last uncertainty in what the "true" slip rate actually is for a variability in slip rate over time or 190 sentence particular section of fault of interest. If the distribution also distance. includes aleatory variability. as implied in this sentence, there should be a discussion of how that variability is estimated and distinguished from the epistemic uncertainty. Also. if that variability is dependent on the location along a fault, then that should be indicated and discussed as well. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location in PPRP Comment Text for Summary of Revisions to Report Number Text1 Comment Revision Section 8.3, The discussion would be easier to follow if the location of Figure 8-13 The location of the Piedras Blancas page 101, the Piedras Blancas anticlinorium were shown on Figure anticlinorium has been added to Figure 191 paragraph 4, 8.3.1 (at a minimum, some appropriate figure locating that 8.3.1 Line 4: feature should be referenced). Section 8.3, Are the seismic reflection data used to constrain slip rates No change The sentence states that 'Interpretation 192 Page 101. or interpret them? of offset channels ... constrains .. .'. The Paragraph term constrains is appropriate --4, line 7 therefore, no change needed. Section Please expand the discussion on the preferred offset. as Figure 8-14 Figure and text modified to provide 8.3.1, page the figure only shows Oso terrace offset as a minimum at Lines 497-more explanation of the preferred offset 193 102, Figure 150 m. Figure 8.3-3 mentions piercing points across the 509 (and constraints on range of values) as 8.3-2 HFZ as the basis for preferred offset; consider labeling on described in the text. Fiqure 8.3-2. Section The discussion of Figure 8.3-3 would be easier to follow if Figures 8-16 We agree. The text and figure are 8.3.1 page the panels were labeled (i.e., a,b,c) and cited specifically Lines 497-updated to reflect this change. 103, 2nd (e.g., Figure 8.3-3(a)). This comment applies to many of 509 194 paragraph the composite figures in the chapter. (and following paragraphs): Section Traverse Range?? Do you mean Transverse Ranges, or Line 213 Text modified to read ... in the western 8.3.1, Page WTR?? Transverse Ranges ... 195 103, 3rd bulleted paragraph Section "require reversal in uplift for the lower terraces" Please Figure 8-15 We have added a new figure to illustrate 8.3.1 , page provide more clarification why the Muhs et al.. 2012 this better. and revised the text 196 103. 3rd studies on San Nicolas Island would require that. Line 496 accordingly paragraph, 3rd bullet 2 lines up 197 Section The CDF curve does not plot exceedance probability, but Lines Text corrected. 8.3.1, page rather its complement. Please correct this, and check the 519-523, COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location in PPRP Comment Text for Summary of Revisions to Report Number Text1 Comment Revision 104, 2nd use of the word "exceedance throughout the chapter, as it 605-607, paragraph seems to be used repeatedly in this same erroneous 1434-1436, on page, sense. 1533-1534, Lines 2 and 1732-1734, 3: 1839-1840, 2133-2135 Section "hence broader, are not inconsistent with ... " This is a Lines 528-Text modified to remove double 8.3.1, Page double negative. Is it possible to make this more straight 531 negative. 104, forward to "are consistent with"? 198 paragraph 7 (last of section), line 2,3 Section "Cumulative density function" is incorrect. You may mean Lines 590-Text corrected 8.3.2, page either "probability density function" or "cumulative 594 199 105, 3rd distribution function" (probably the latter, since that is paragraph, what appears in the last panel of the figure under Line 3: discussion, FiQure 8.3-5). Please clarify. Section Please consider rewording to avoid ambiguity, since the Lines 606-Text corrected 8.3.2, page tabulated probabilities are not exceedance probabilities, 608 200 105, last but their complements. paragraph on page, Line 2: Section Figure 5-9 does not seem to show the Piedras Blancas Figure 8-13 Call out to Figure 5-9 has been changed 8.3.3, page anticlinorium. as the text implies. If it does not, please to be Figure 8.3-1 (now Figure 8-13). A 201 106, 1st remedy this inconsistency. label has been added to Figure 8-13 to paragraph of show location of the PB anticlinorium section. line 2: Section Please elaborate on the implications of "the western Lines 657-Text has been added to better explain 8.3.3, Page branch of the Hosgri is not the current locus of 661 the constraints of possible slip that may 202 107, deformation." Does this imply that this fault strand does be added to the Hosgri fault source to paragraph 4. not increase the Hosgri rate to the south? Please provide the south based on the observation of last line an explanation of the significance of this observation. no offset of datums inferred to be 135-COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location in PPRP Comment Text for Summary of Revisions to Report Number Text1 Comment Revision 125 ka. The constraints on slip rate emphasize that the 0.2 mm/yr modeled for Piedras Blancas is conservative. Section Please rephrase this sentence as it is not clear. Lines 771-This sentence and preceding sentence 8.3.4.2, 775 were modified to clarify statements. 203 Page 109, Paragraph 4, line 7 Section "at least five glacial terminations" Are you referring to Line 826 Text modified to add the word 'major' 8.3.4.3, major (100 ka) glacial phases, as appears to be the case? before glacial terminations. 204 Page 110, If so, please indicate that these are major glacial Paragraph terminations. 4, line4 Section "Paleo slope breaks associated with unconformities H10 Lines 656-Additional discussion has been added. 8.3.4.3, and H30 occur more than 1 km west of the paleo slope 601 page 111, break associated with unconformity H40 (PG&E, 2014, Lines 871-7th Chapter 3 Figure 6-3, and Figure 8.3-6) suggesting that 890 paragraph, 5 the lowstands preceding H10 and H30 reached 205 lines down significantly greater depths than the lowstand preceding H40. This relationship strongly supports the preferred unconformity age model and contradicts the relationships that would be predicted by the alternative model (Figure 8.3-7)." This argument is important and would benefit from additional discussion. Section Could the relatively high amplitudes from the channel Bottom of A footnote has been added speculating 8.3.5, page thalweg be gas? Please consider whether gas might give page 8-32 of that the higher amplitudes may result 113, 5th rise to some of the observed changes in acoustic 8-74 below from gas trapped within channel 206 paragraph, 7 reflectivity. Line 1004 sediment. We wanted to avoid lines down discussing this in the body of the text because it distracts from the main message, which is that channels are difficult to distinguish on these data. 207 Section "Due to this uncertainty, the Tl team assessment of offset Lines The full range of Channel F offset 8.3.6, page across the fault does not rely directly on channel Fe." How 1078-1081 considered by the Tl Team exceeds all COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location in PPRP Comment Text for Summary of Revisions to Report Number Text1 Comment Revision 115, 2nd does this affect overall slip rate estimates? What were the of the uncertainty estimates reported in paragraph, estimates from the PG&E 2014 CH3 report? PG&E, 2014 Ch. 3, but the mean last estimates are the same. Text has been sentence added to this section to clarify that point. Three alternative correlations for Channel Complex F and associated offsets were presented in PG&E 2014 Ch. 3. Correlations and offsets were reported as follows: Preferred, entire HFZ: Fe3/Fw3 min. 550 Max. 700 Pref. 600-650 Alternate, entire HFZ: Fe1/Fw3 min. 450 max. 600 pref. 500-550 Western Strand: Fc1/Fw3: min. 376 max. 490 pref. 435 Eastern Strand: Fe3/Fc1: min. 150 max. 250 pref. 200 PG&E (2014, Ch. 3) calculated slip rates for the preferred and alternate correlation across the entire HFZ. No attempt was made to sum the offsets across individual strands and use those to estimate a slip rate. Section Fe1 and FW1 are not shown in Figure 8.3-16 Figure 8-29 Channel thalwegs for Fw1 and Fw2 208 8.3.6 page were added to the figure, and a callout 116, Figure was added to the boundary of Fe1. 8.3-16 Section As stated later, the slip rates to the north are expected to Lines The single GDF describes epistemic 209 8.3.7, Page be higher than at DCPP, whereas the southern slip rate is 1106-1118 uncertainty in the part of the HFZ 116, expected to be lower due to pulling slip I deformation off directly offshore of the DCPP. The Tl Paragraph 1 onto the Los Osos, San Luis Bay and other faults. Please team considers it likely that slip rate COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location in PPRP Comment Text for Summary of Revisions to Report Number Text1 Comment Revision discuss the implications of combining all of the rates into a increases to the north, and has single CDF. incorporated that judgment into the SSC model through the use of additional rupture sources on the HFZ to the north of the DCPP. A discussion of this issue has been added to the text. Section This statement would appear to imply that the slip rate Lines Yes the slip rate assessments at each 8.3.7, p. estimates at each site are epistemic assessments of the 1136-1140 site represent the epistemic uncertainty 116, 1st true rate at each site, but the weights assigned to each of in the SR at that site. The weights paragraph, the sites represents the degree of belief that any given assigned to the alternative reflect the Tl last site is an indicator of the rate along the fault near the plant Team judgment as to the likelihood that 210 sentence site. This is all epistemic uncertainty. However, as stated the individual site assessments are below in the last sentence of this paragraph, the representative of the rate along the fault integrated distribution might also have an aleatory near the DCPP (based on quality of component in it, implying that there is true variability in the data and proximity to the site) (i.e., slip rate opposite the plant. Please explain if this is the epistemic uncertainty in the SR for the case. fault closest to the DCPP). The text is modified to clarify this point. Section Does this imply that there is aleatory variability in the -see above-No: see response to 209 and 210. 8.3.7, p. integrated distribution across all sites? because any correction 211 for tectonic uplift/subsid ence rate to these terrs Section Please note that the first column heading should be Line 1255 Corrected as suggested. 212 8.3.8.3. "Zeng" (not "Zheng"). page 120, Table 8-1, Section The CDF table may have a typo, as the first two entries Figure 8-39 This is not a typo. These numbers are 213 8.4.1, Figure give different cumulative probability, but at the same slip the same when rounded to two decimal 8.4-6: rate. places. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location in PPRP Comment Text for Summary of Revisions to Report Number Text1 Comment Revision Section Refers to the "lateral slip is a good approximation of the No change Text not changed. 8.4.1, Page net slip rate." But that hasn't been presented yet. It may 123, be better to state that it "will be" a good ... The slip rate doesn't change whether 214 paragraph 3, we have presented it or not. The ratios line3 of horizontal to vertical offset demonstrate that the lateral slip rate (whatever it is) is a good approximation of net slio rate. Section It is important to determine if the terrace riser is older or Figure 8-37 The profile in Figure 8-37 is the best 8.4.1, page younger that H40 -Are there any seismic data, that would one to use for evaluate this relationship. 123, 4th allow the Tl team to trace H40 from the west? The Tl Team has explored the available paragraph, data and has concluded that the H40 215 10 lines unconformity cannot be traced down continuously into the San Luis Obispo Bay area with high confidence, but it is likely that the unconformity continues. The plausible extension of H40 was added to the figure. Section The last 10 or so lines of this paragraph are somewhat Lines 1390-The text in question was clarified. 8.4.1, Page confusing. Could this be made clearer I simpler? 1395 216 123, paragraph 4, Figure 8.4-5 Lower part of figure has an arrow to the right with 630 ka, Line 1418 The age quoted in the text was 217 which refers to the possible upper end of the age range of corrected. The slip rate is calculated the terrace sequence. In the text on page 124, 1st using a maximum age of 630. paragraph, 625 ka is stated. Please be consistent. Section Please reference Figure 8.4-2 providing the map showing Line 1442 Added as suggested 8.4.2, Page location of channel I, which the subsequent discussion in 218 124, 1st this paragraph relies upon. paragraph of section. 1st line: 219 Section Please reference Figure 8.4-2. which provides the map Line 1541 Added as suggested 8.4.3 Page showing location of channel A that the subsequent COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location in PPRP Comment Text for Summary of Revisions to Report Number Text1 Comment Revision 127, 1st discussion in this paragraph relies upon. paragraph of section, 1st line: Section Please explain what observation or analysis led the Tl Lines New text was added to explain why the 8.4.3, Page Team's interpretation to differ from the previous PG&E 1556-1558 Tl team did not accept the PG&E 127, 3rd interpretation. 1576-1594 interpretation, and chose to re-interpret paragraph, the data. 220 second to last sentence and last sentence: Section The assumption here is that lithology and stream power Lines The paragraph has been modified to 8.4.3, Page are similar over time, which is likely the case as these 1656-1663 clarify the assumptions 128, 6th three "streams" likely originate from the same drainage 221 paragraph, source. This should be made clear that they all have the lines 9-10 same source, and that the drainage area has not likely evolved much to its present state over the expected age range of these three channels. Otherwise, the rest of the an::iuments in this section fail. Section Should the reference be to Figure 8.4-13? Figure 8-38 No. The cited figure (8.4-5) shows the 8.4.3, Page range of possible ages relative to the 222 129, 2nd sea level curve paragraph on page, Line 7: Section Please summarize what specific observations and/or Lines The section was re-organized to better 8.4.3, Page analysis led the Tl Team's age model to differ from the 1600-1647 describe the previous PG&E age model 129, 2nd previous PG&E model. 1727-1730 and describe why the Tl Team's age 223 paragraph model is different. on page, last sentence: 224 Section Might want to rephrase the sentence below so it is clear Line 1702 We have rephrased the sentence to COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location in PPRP Comment Text for Summary of Revisions to Report Number Text1 Comment Revision 8.4.3, page that Channel A is older than Channel C -"The MIS 6 age eliminate the erroneous statement that 129, 9th alternative is preferred and assigned a weight of [O. 7] channel C was older than Channel A. paragraph, 3 based on the observation that Channel A is crosscut by lines down Channels Band C, and therefore must be older than them (Figure 8.4-11) and the greater depth of incision of Channel C, suggesting it is likely a full sea-level cycle older than Channel A (as described above and illustrated in Fioure 8.4-12)." Section The San Luis Bay "kinematic indicators of strain No change The observation of reverse to reverse-8.4.4.2, (slickenlines) are compatible with reverse or reverse left oblique slickenlines on a trace of the Page 131, oblique slip" This is the first time that the possibility of left San Luis Bay fault is one of the reasons 2nd bulleted oblique slip has been raised. Is this congruent with the that the OV model is not weighted point OV model, which implies right oblique slip on the parallel higher than it is. This observation is Los Osos fault? essentially a strike against the OV model, but it does not completely invalidate the model. These slickenlines are observed on just one 225 trace within a zone of surface faults that we interpret to be secondary to the primary fault at depth. It is possible that this particular trace last deformed in a reverse or reverse-left oblique sense, but the fault zone as a whole generally accommodates dextral oblique reverse motion. No change to text Section "Based on this assessment. the uplift rate of the Irish Hills Lines The chapter has been reorganized to 8.4.4.2. Slip ranges from 0.15 mm/yr to 0.35 mm/yr, but most likely is 1814-1820 provide the assessment of Irish Hills rate of between approximately 0.18 and 0.23 mm/yr." Please uplift rate in the approach, Section 226 SWBZ, page expand on why is it most likely? 8.2.2. A reference to that section has 132, 1st been added as explanation of why uplift paragraph 7 rates between 0.18 and 0.23 mm/yr are lines down most likely. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location in PPRP Comment Text for Summary of Revisions to Report Number Text1 Comment Revision Section The input parameters for the resolved slip calculation are Figure 8-48 This figure has been divided into two 8.4.4.2, in Figure 8.4-15 (not 8.4-16). separate figures (8-48 and 8-49) to Page 133, clarify the slip rate calculations. The 227 3nd figure references have been updated. paragraph on page, Line 1: 8.4.4.2, This discussion seems to indicate that the vertical rate on Lines An introduction and conclusion to this Page 134 the Shoreline fault is possibly on par with the horizontal 1782-1796 section have been added to explain that and 135 rate (up to 0.11 mm/yr vertical, with a best estimate of this simple kinematic model is used to 0.07 mm/yr horizontal). Is this consistent with other Lines justify an increase in slip rate on the interpretations that the Shoreline fault is mostly strike-1953-1955 northern Shoreline fault relative to the slip? (focal mechanisms, offset channels and shoreline 1966-1995 southern Shoreline fault, a difference features, vertical dip, etc.). Please clarify the support for that the Tl Team interprets to be likely. this interpretation. The Tl team acknowledges that vertical separation predicted by the model is not 228 consistent with the other observations pointed out in this comment, and therefore does not include that component of slip into the net slip rate assessment for the Shoreline fault. Given the small differences in slip rate, the Tl team judges that use of this simple model is appropriate in lieu of a more complicated model that better fits all observations. Section "The second age model is called the post-LGM age Lines Text has been added that elaborates on 8.4.4.2. model. This model, which is assigned a weight of [0.4), 1941-1944 processes that may have led to Constraints accounting for the possibility that the wave cut platforms development of wave-cut platforms on Vertical mapped by PG&E (2011) do not represent long-lived during the last transgression. 229 Separation stillstands. and may instead be erosional surfaces Rate developed during the last transgression." Please provide Lines We have also modified the justification Offshore of additional justification for this weight, given the Tl's 1924-1935 for our weight on the MIS 3-5 model by Irish Hills, assessment that the MIS 3 -5 age is likely to be "correct". stating it is "more likely to be correct page 135, than the alternative model." COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location in PPRP Comment Text for Summary of Revisions to Report Number Text1 Comment Revision 3rd paragraph, 15 lines down Section 8.5, Please consider referencing the section of the report Line 2049 Cross reference to Section 7.4 added page 136, where the concept of "fault models" was defined and the as suggested. 230 2nd NE, SW and OV cases introduced. paragraph of section, 2nd to last line: Section Hanging wall uplift-rate PDFs (Figure 8.5-2) and footwall Figure 8-55 The CDFs shown in Figure 8-55 were 8.5.1, page uplift-rate PDFs are all bounded density functions. Please calculated using the Monte Carlo 138, explain how bounded PDFs (as opposed to discrete method described in Section 8.2.1. The 231 probability mass distributions) can combine to give the steps in the CDF result from the bin size discontinuous CDF's shown in Figure 8.5-6 (hint: they of Monte Carlo sampling. A note has can't), or clarify how the CDF's in Figure 8.5-6 were been added to this and other figures to actually calculated, or correct the plot (and subsequent describe this. ones) if it is erroneous. Section "The maximum value considered is -0.21 mm/yr based Lines Text is modified to indicate that the 8.5.1, page on the assumption that the magnitude of hanging wall 2092-2097 maximum subsidence rate is set at 0.2 138, 4th uplift (preferred uplift rate of the Irish Hills) is the upper mm/yr based on Tl Team judgment that paragraph, limit on footwall subsidence as predicted by various the subsidence rate of this small crustal last structural models (e.g .. King et al., 1988; Stein et al .. depression does not exceed the uplift sentence 1988)." rate of the Irish Hills, a much larger crustal block. 232 Please provide clarification here as hanging wall uplift Reference to the Stein and King models causes rock to displace air-large density contrast: has been removed. whereas foot wall subsidence causes crustal rocks to displaces mantle -small density contrast -it is the density contrast and associated buoyancy that controls magnitude of subsidence. Thus subsidence is larger than associated uplift for both extensional and compressional environments. 233 Section Please state the rationale that the selected fault dips Line 2121 Cross reference to appropriate sections 8.5.1, page adequately represent the full technically defensible range, of Chapter 7 have been added. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location in PPRP Comment Text for Summary of Revisions to Report Number Text1 Comment Revision 138, last or reference the section of the report that does so. paragraph, 1st sentence: Section Please state the technical justification for the range of Lines Additional text and a cross reference to 8.5.1, page rakes employed. 2123-2131 Section 7.2.4 was added to explain 138, last range of rakes assigned to different 234 paragraph of styles of faulting. section, 2nd to last sentence: Section The terminology used in Figure 8.5-7 is ambiguous. What Figure 8-56 The figure has been modified to show 8.5.1, page does "deviation from vertical mean there? Unless the the rake angles. 138, last fault has a dip of 90 degrees, then there is no vertical 235 paragraph of reference direction within the fault plane. If you mean the section, 2nd complement of the rake angle, please say so (or to last "deviation from the up-dip direction"). sentence: Section Here, the Memorial Park terrace is potentially correlated Line 2111 Revised text in Section 8.2.2.3 8.5.1, Page to the -400 m (should read -400 ka); ... Earlier, 400 ka discussing the estimated age of the 138, was suggested as a minimum age for this terrace. Which Memorial Park surface shows that paragraph 6, is it, and what is the likelihood that it is younger, as this correlation of the surface to MIS 11 236 line 14 discussion was not very clear earlier in the report. (-400 ka) is a reasonable interpretation, not a maximum age. A cross reference has been added to Section 8.2.2.3. Section In discussing Figures 8.5-8 through 8.5-10, please explain Figures 8-57 The apparent steps in the vertical rate 8.5.2 page how the net slip rate can have a continuous CDF to 8-59 CDFs result from the sampling bins 237 138, 1st (implying a bounded PDF), while vertical rate has a used in the Monte Carlo calculations. A paragraph of discontinuous CDF (implying a discrete probability mass note has been added to the figures to section. Line distribution). state this. 2-3 238 Section The expression "the center of the range" is used here Lines The description has been updated to 8.5.3, Page without definition. It seems to correspond to the 21st to 2155-2162 provide the range and weighted mean COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location in PPRP Comment Text for Summary of Revisions to Report Number Text1 Comment Revision 139, 1st 79th percentile values in Figure 8.5.11, but similar 2257-2264 values for each of the three fault paragraph of expressions (e.g .. "center of the PDF") have been used models. section: previously in the report for intervals defined differently. Please make the intended meaning clearer here. Section 8.6, Note the extra ". )" at end of paragraph. Line 2215 The parenthesis has been removed. 239 Page 1, 1st paragraph, last line: Section Please reference the section of the report where the Line 2214 A reference to Section 7.4 has been 8.6.1, page alternative age models were evaluated and the weights added to the end of the previous section 240 1, 1st cited here were justified. (when the three models are first paragraph of mentioned). section, last line: Section If this statement refers back to an assessment from an Lines References to Section 8.2.2.1 and the 8.6.1 page earlier part of the report, that section should be 2224-2225 pertinent figures have been added. 241 1, 2nd referenced. In not, please provide a more complete paragraph of statement of the technical justification here. section, 2nd sentence: Section "Deviation from vertical is not an acceptable terminology, Lines The figures and descriptions have been 8.6.2, page because it is ambiguous (there is no vertical reference 2252-2253 modified to show the rake angles. 242 1, 1st direction in the fault plane unless dip is 90 degrees). paragraph of Please use a conventional and unambiguous terminology. Figures 8-56 section. 1st and others line. Section Please explain why the GDF for the vertical rate appears Figures 8-62, A note has been added to the figures 8.6.2, page to be discontinuous (stepped) in Figures 8.6-2. 3. and 4 8-63, and 8-explaining that the apparent steps in the 1, 1st (which would imply a discrete probability mass function). 64 GDF result from the bin size for 243 paragraph of or correct the figure. sampling in the Monte Carlo section. last calculations. line on page: 244 Section Please state the technical justification that the selected Line 2250 A reference to Section 7-4 has been 8.6.2, page fault dips adequately represent the full technically added. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location in PPRP Comment Text for Summary of Revisions to Report Number Text1 Comment Revision 2, last defensible range, or reference the section of the report paragraph of that does so. section, Line 2: Section The sentence refers to a PDF for fault rake, but the range Line 2253 The angles have been changed to 8.6.2, page of angles cited seems to apply to the complement of the describe uncertainty in the rake. 2, last rake. Please check and make a correction if needed. 245 paragraph of section, last sentence: Section Please clarify the meaning of the "plus or minus 1 degree" Line 2253 The text has been revised to clarify that 8.6.2, page in the description of the distribution. a uniform distribution is used. 246 2, last paragraph of section, last sentence: Section Please state the technical justification that this rake angle Lines A paragraph has been added at the end 8.6.2, page distribution adequately represents the full technically 2231-2242 of 8.6.1 describing the justification for 247 2, last defensible range, or reference the section of the report the rake angles considered. paragraph of that does so. section, last sentence: Section Please indicate left or right oblique. If right oblique, Lines Text has been added to explain that the 8.6.3, Page please explain why it is different from earlier statements 2231-2242 rake is interpreted to be dominantly 248 2, 3rd bullet that kinematic data suggest left oblique to reverse. If right reverse with uncertainty in both oblique, please explain (somewhere) how the SLB and directions. Los Osos faults, which are nearly parallel. can have the opposite sense of oblique slip, if that is the case. Lines Added discussion of UCERF3 rates. 2291-2296 Section 8. 7, "San LuisPismo" is written "San Luis-Pismo" in the list of Line 2298 Text has been through technical edit to 249 page 1, 1st abbreviations and acronyms, and in most occurrences correct to San Luis-Pismo. paragraph, elsewhere in the report. line 1: COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location in PPRP Comment Text for Summary of Revisions to Report Number Text1 Comment Revision Section Please indicate whether the oblique slip is left or right Line 2322 "right-" has been added before oblique. 8.7.1, Page oblique. 250 1, Paragraph 2, last line Section Please provide a reference to a report, or to a section Lines Sensitivity analyses presented in 8.7.1, page (and figure) of this report, that documents the sensitivity 2315-2316 Chapter 6 of the Shoreline fault report 1, 2nd analysis cited here. (PG&E, 2011) and in Workshop 1 251 paragraph, (documented in Appendix D of this Line 1: report) both support the statement made here. Reference to that documentation has been added. Section Please check whether "Wilmar Avenue fault" should be Line 2375 The fault name has been corrected 8.7.2, page "Oceana fault" instead. 252 2, last paragraph on page, Line 1: Figures in The discussions of total slip and age PDFs and the Figures 8-6, These references have been added to Chapter 8, associated slip-rate CDFs in the chapter would be easier 16, 18, 28, the figures 253 general to follow if the multi-panel figures such as Figure 8.3-3, 32, 39, 42, comment: 8.3-5, and many others. had panel labels (i.e., "a", "b", "c", 46, 49, 52, etc), and if the individual panels were referred to by letter 55, 56, 61 in the text (e.g .. "Figure 8.3-3a"). 254 Figure 8.5-5: Is the location of the D-D' cross-section shown in Figure Figure 8-53 The cross section location has been 8.5-5? added Figure 8.5-7: "Deviation from vertical" is ambiguous: please correct Figure 8-56 "Deviation from vertical" has been 255 this. removed, and the figures are updated to show rake of the faults. Figures 8.5-"Deviation from vertical distribution" (footnote to the table Figures 8-57, "Deviation from vertical" has been 256 8, 9 & 10: on right of figure) is ambiguous; please replace with 8-58, 8-59 removed, and the figures are updated to standard, unambiguous terminology. show rake of the faults. 257 Figures 8.6-"Deviation from vertical distribution" (footnote to the table Figures 8-62, "Deviation from vertical" has been 2, 3. &4: on right of figure) is ambiguous; please replace with 8-63, and 8-removed, and the figures are updated to COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location in PPRP Comment Text for Summary of Revisions to Report Number Text1 Comment Revision standard, unambiguous terminology. 64 show rake of the faults. Figures 8.6-In the footnote to the table on right of each of these Figures 8-62, The note has been updated to more 258 2, 3, &4: figures, the meaning of "1-19 degrees plus or minus 1 8-63, and 8-clearly describe that uncertainty in rake degree" is unclear. 64 is represented by a uniform distribution from 70 to 110 degrees. COMMENT-RESPONSE LOG DIABLO CANYON SSC STUDY DRAFT REPORT PPRP COMMENTS AND Tl TEAM RESPONSES, CHAPTER 9 Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision CHAPTER 9-Rupture Models 547 Line 5 "Historical ruptures have involved .. . Some historical ruptures? Many Line 5 Text revised to clarify historical ruptures? Please clarify. 548 Line 6 "single fault zone" is referenced to the 1992 Landers earthquake, Line 6 Text revised to clarify which actually involved 5 separate faults. Please clarify or correct. 549 Line 8 Using a colon after "styles of faulting" is change in style from earlier in Line 8 Text revised for consistency the paragraph where the earthquake was in parentheses. Please make consistent for clarity of readinci. 550 Line 13 "define fault rupture lengths" Do you mean to define potential rupture Lines 13-20 Text revised to clarify lengths? Define the potential for future rupture lengths? Define future potential rupture lenciths? Please clarify. 551 Lines Please state more explicitly the technical rationale for the choice to Lines 27-42 Text revised to better explain the concepts behind the 28-30 treat the rupture sources as aleatory variability. How is it different from development of the Rupture Model with respect to aleatory a recurrence curve that expresses the aleatory variability in the variability and epistemic uncertainty magnitudes (and rupture dimensions) of possible earthquakes that occur on a fault source? Additional explanation is needed to understand the concept, the technical basis, and the implications to the SSC model. Also, there is an implication that epistemic uncertainties have not been included. It is recommended that the manner in which epistemic uncertainties were captured be identified here in juxtaposition with the statement that epistemic uncertainties are not included in the modeling of rupture sources. 552 Line 37 Plate 9-1. Please explain why the surface projection of dipping rupture Plate 9-1 No Revision. North of the DCPP, all Hosgri FGMs have a source changes along strike for 75* dip, but appears more constant for vertical trace. This is for simplicity with linked and complex 85" ruptures involving northern Hosgri and SLPB faults. It is not important to hazard as the difference in fault width is small, and the difference in source-site distance, etc. is likewise small 553 Lines There is epistemic uncertainty regarding the slip rates, but how is slip Lines 65-68 Text revised to clarify 45-46 rate itself treated as epistemic uncertainty. Please clarify your mean in a. 554 Line 49 "A demonstration" or "demonstrations" ?? Line 71 Text corrected. 555 Lines The fault names should all be followed by fault for clarity (i.e., Hosgri Lines 79-80 Text revised as suggested. 57-58 fault, Shoreline fault, etc.) 556 Line Please clarify that the historical examples from Chapter 7 were Line 85 Text revised to clarify. 62-63 possible analogues for each FGM. taken from other regions. COMMENT-RESPONSE LOG DIABLO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision 557 Lines Both here and Line 231, the declaration is made, without much Lines 81-91 Text revised to clarify. 65-68 technical basis, that the suite of rupture sources "captures the range of viable ruptures." How is this consistent with the SSHAC imperative to capture the CBR of the TOI? What is the basis for judging that the range is captured, especially since the approach of identifying specific rupture sources is different from the classic approach of defining recurrence curves for each fault source? It is noted that the range is considered adequate to capture the sources that contribute significantly to the hazard. Were there hazard sensitivity analyses conducted to support this assertion? 558 Line 81 The descriptions of the respective rupture source types in Figure 9-1 Figure 9-1 Figure modified. differ significantly from the definitions given in Table 9-2. If the figure and table are intended to convey different types of information, please make that clear in the text and figure caption. In any event, please make sure that it is clear which characteristics are the defining characteristics of the rupture source types, and which just represent typical examples. 559 Line 84 Explain what defines the length of a characteristic rupture as being Lines 105-111 Text revised to clarify the terminology and to avoid confusion <100 km. There are many worldwide examples of longer with regard to criteria !Of defining a characteristic-type rupture. characteristic' ruptures. Are you saying the Hosgri fault only produces characteristic ruptures that are less than 100 km in length (-M7.2). Clearly later in the report, this is not the case. There needs to be some explanation as to why you broke out characteristic behavior to be limited to relatively short rupture seqments. 560 Line 96 Please replace comma with a semicolon after GMC model, Line 121 Text revised as suggested 561 Line Please consider some alternative way to describe "splay" rupture Lines 130-132 Text revised as suggested to better define splay type of 105 source type, because "overlapping source planes" is ambiguous (i.e .. rupture. in what sense do the planes overlap?). Branching of the rupture surface seems to be an important element. 562 Line "Based on empirical observations" implies that there is a direct linkage Lines 143-149 Text revised as suggested 117 between the observations and the topologies, and little judgment required by the Tl Team. Isn't it more accurate to say that the topologies are developed by the Tl Team based on a consideration of historical earthquake ruptures that may be analogous to the ruptures in the reaion? 563 Lines Isn't down-dip hyphenated? No change No hyphen. downdip" is designated as one word in the PG&E 119 Style Guide word list. The technical editor has checked and numerous times on Google Ngram Viewer for its spelling in the 130 literature. The results consistently show that the one-word spelling is more common than the hyphenated spelling. The Schlumberger Oilfield Glossary also lists it as one. COMMENT-RESPONSE LOG DIABLO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision 564 Line The description of slip rates for complex and splay rupture sources is Lines 150-152 Text revised to clarify 123-ambiguous. For example, if the intended meaning is that the primary 125 part of a rupture source (complex or splay) has a uniform slip rate and the secondary part of the same rupture source has a different uniform slip rate, please make that clear. 565 Line This sentence seems to be missing a verb. Please correct for clarity. Line 160 Text revised to add missing verb 132 566 Line The only stated exception to the obtuse angle requirement is the Because the intersection angle between the Los Osos and San 138-Hosgri-Shoreline splay. Please explain how the Los Osos-San Luis Luis Bay is at depth, and there ii is acute. 141 Bay splay is consistent with this taxonomy (i.e., why isn't ii also considered an exception to the obtuse anqle requirement?). 567 Line The three types of features" does not seem to include major steps or Lines 175-179 Text explains that this was considered for one of the rules to 143 bends, although the majority of historical ruptures had endpoints at develop the rupture source. but was not needed as an explicit steps or bends. Was this intended? rule for the DCPP rupture sources. 568 Lines Please include references to the corresponding figures from Chapter 6 No change required. 156-on which the segment locations are shown. Plates 9-1 and 9-2. which are referenced in the first sentence 162 of this statement, define each seqment location and name 569 Line This sentence is confusingly written, because the subject is ruptures Lines 197-199 Text revised as suggested 164-[across branch points)" and the direct object is also "ruptures." Please 166 rewrite to make it clear that it is the branch points themselves that may be the sites of rupture arrest more frequently than are generic fault ooints. 570 Lines This seems to imply that more ruptures will include both the Hosgri Lines 208-210 Statement added to clarify that the boundary is used to assess 170-and San Andreas faults, versus the Hosgri-San Gregorio fault where it Mmax lengths, which should remind reader that these rupture 174 meets the San Andreas fault. Is this what you intended to mean? source total lengths are for the largest Mmax earthquakes. Please clarify. 571 Lines In defending this conclusion. perhaps the point should be made that Lines 266 to 276 Text revised as suggested. 231-the CBR is supported by the careful review of analogies and the fact 234 that the salient elements of the rupture topologies are supported by observations that they have occurred elsewhere during actual earthquakes. Are there hazard sensitivity cases that show this? 572 Line Please consider replacing "in which" to where Lines 306-308 Text revised to clean up sentence structure. 266 573 Line Please consider replacing "Although this result was considered by the Lines 315-317 Text revised as suggested 275 Tl Team in developing the rupture sources," with -Although the Tl Team considered this result when developing the rupture sources," 574 Line Please spell out RO and LH on figure Figure9-2 Figure revised as requested to include explanations of 281 abbreviations Figure 9-2 575 Line Approximately 6 km in which direction? Line 324-325 The 6 km refers to the length of surface rupture on the 284 Kawafune fault as shown on Figure 9-2 COMMENT-RESPONSE LOG DIABLO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision 576 Line Kawafune? Is this a fault name? Please specify "fault" Line 325 Text revised to add the word 'fault' 285 577 Line If both were reverse displacements, it would be clearer to say Line 326 Text revised as suggested 286 "opposite sense of vertical slip" 578 Line General dip angle? Do you mean average dip angle? The general Lines 345-346 Text revised to clarify. 305 direction of dip? Please clarify. 579 Line Stretches? Do you mean extends? Line 349 Text revised to use the term extends instead of stretches. 309 580 Line Is M6.5 a large earthquake? Most seismologists would consider this a Line 350 Text revised as suggested 310 moderate event. Rather than using "large", you could say "surface-ruoturina earthauakes 581 Lines No fault section has been defined to indicate what "that section of the Line 356 Text revised to clarify. 315, fault" refers to. Please clarify. 318 582 Line You should also reference Sieh, 1996. as this was one of his Line 365 Reference added 325 examples to argue for the slip patch model. 583 Line Subsurface rupture? Line 378 Text revised to correct to 'subsurface' 336 584 Line "bordered the flank Do you mean bordered" orflanked". This Line 381-385 Text revised to clarify. 341 statement is unclear, as written. 585 Lines Are you referring to rupture of the Brawley fault? Please clarify this Line 384-385 Yes. Text clarified. 341-342 586 Line Please consider deleting "instruments". Line 387 Text revised as suggested. 344 587 Line Please change "Displacement on" to displacement in Line 402 Text revised as suggested 359 588 Line "several major and many right-lateral faults"? Consider deleting "and Line 408 Text revised to add *minor' as an adjective 365 many" or qualify as "many minor" 589 Line Geodetic strain needs more clarity of meaning. Wasn't the geodetic Line 410 Text revised to add the modifier 'historical' before strain as 367 strain fairly localized? described in the source reference (Sieh et al. t993). The description is of the ECSZ as a whole, not the Landers rupture. 590 Line Does a 30 degree change in strike count as sub-parallel?? Line 412 Text revised to delete the term 'subparallel' 369 591 Lines This is somewhat misleading and semantic. The Landers/Kickapoo Lines 415-421 Text revised 372-fault is essentially co-I inear with the southern section of the Johnson 373 Valley fault (which wasn't recognized prior to the 1992 earthquake). Basically, the Landers and southern JVF are the same fault. The rupture stalled for 7 seconds at the intersection with the Homestead Valley fault, and then re-nucleated on the HVF to continue the rupture. Two maior sub-events. See fiaure below. Comment Location Number in Text 592 593 594 595 596 597 598 Lines 375-376 Lines 378-380 Line 385 Line 386 Line 395, Figure 9-6 Lines 407-408 Lines 412-413 COMMENT-RESPONSE LOG DIABLO CANYON SSC STUDY DRAFT REPORT PPRP Comment Location in Textfor Comment Revision The step from the Emerson fault to the Camp Rock fault is not Line 420 contractional -it is also a releasing step. Please provide references for estimates of stress drop and the Lines 425-433 relationship between stress drop and recurrence intervals (e.g., Rockwell et al., 2000). Please add year (2012) to Madden and Pollard. Line 438 Please change "to better resolve" to to resolve better. Line 439 Please explain "culled measurements" Figure 9-6 Angle of the prestress? Or just the fact that the main Denali was Lines 490-495 stressed whereas the eastern Denali was not. probably due to a recent failure. Please clarifv What is meant here? Most faults were previously mapped and named Lines 497-509 (Barnard. 1965). Are you just saying that it wasn't known that they would rupture together? In the same sense, the 1992 Landers earthquake identified a previously unknown fault system, and the southern Johnson Valley fault was not known in the literature. Please clarifv. Summary of Revisions to Report Text revised to correct statement. Additional text added as requested. Text revised as suggested. Text revised as suggested. No change. Reader is directed to Wesnousky (2008) for explanation. This is not germane to the SSC model Additional text added to discuss this concept. Text revised to clarify. COMMENT-RESPONSE LOG DIABLO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision "Previously unidentified fault system" is an accurate quote from the study of Fletcher et al. However, many of the individual faults involved in that rupture were known and mapped beforehand. Please consider adding a few words to clarify this point. 599 Line Check this. There was a foreshock on a north-striking normal fault. but Line 505 Fletcher et al. (2014) state that the rupture intiated on a north 417 the mainshock initiated on a northwest-striking fault-the Laguna trending fault (see opening sentence of conclusion); their Salada fault. Please consider, given the uncertainties, whether a less Figure 3 shoes a smaller M 5.7 event at the north end of the categorical statement would be more appropriate. rupture as well. The text is revised to note the central location of the fault on the rupture near a north-trendinQ fault. 600 Lines Please clarify reversal in slip. This could mean normal to reverse. Lines 513-514 The sentence indicated that the reversal was with respect to 424-Right-lateral to left-lateral. What you mean is that the dip direction the sense of vertical slip. The text has been revised to further 425 switched from SW in the southern half to NE in the northern half of the clarify. rupture? 601 Line Series of several?? Please clarify. Lines 518-520 Text revised to delete 'series of' 429 602 Line Is HB vertical? If so, the surface projection of dipping rupture source Plate 9-1 The Hosgri fault from sections HB to the north is modeled as a 447, (pink) stops south of HB. If correct, please state on plate 9-1 or in text. vertical fault. Additional text will be added to Chapter 7 (after Plate 9-the original line 404) and as a note on Plate 9-t to clarify this. 1 603 Line The phrase "uncertainty in the distance" could be understood to Line 545 Text revised to make it clear that it is aleatory variability that is 456 suggest that it represents epistemic uncertainty. The way the model is being discussed in this sentence. employed, that does not appear to be the case, but rather that all of the Hosgri rupture sources occur on any one branch of the logic tree, so that the rupture sources collectively define aleatory variability. If the latter is the correct interpretation, please consider adding some clarification that it is actually aleatory variability in future rupture distances that is modeled bv the device described here. 604 Lines Please add -with different dips -to the end of the sentence below Line 548 Text revised as suggested. 457-459 "These sources are identical in length, extending from the south end of the Hosgri fault to the MT J, but they occupy different strands of the fault zone directly west of the DCPP." 605 Line Please consider adding subscript to H-01 (75), H-02 (85), and H03 (90) Table 9-3 No change to table. Text is clear above that all three 471, in the table geometries use the same rupture model. Adding subscripts Table would add unnecessary clutter 9-3 606 Line How about just a section of the Hosgri fault as a characteristic rupture? Line 560, Table 9-Text added to Section 9.2. t.1 to clarify that characteristic 471 Is this scenario accounted for in one of the models? Please clarify how 3 earthquakes are included in the Magnitude Distribution Models Table shorter Hosgri fault ruptures are accommodated by this model as this (MD Ms) for the longer linked and splay ruptures. 9-3 seems to be the most likely scenario and it is not clearly presented. 607 Lines Models H-01, H-02, and H-03 are essentially the same except for the Scenario is not in the model. Scenario would not meaningfully 476-site to source distance. In reality, they may all fail together as a broad add to variability. uncertainty in ground motions 486 zone -is that scenario in the model?? COMMENT-RESPONSE LOG DIABLO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision 608 Line Consider changing analogy to analogous. Line 588 Text revised as suggested. 499 609 Line "recent 20 dynamic .. . Define "recent. 2003 is 12 years old. Please Line 591 Text revised to delete the word 'recent' 502 clarify. 610 Lines Please consider shortening sentence or breaking into parts. Line 591-597. Text revised to split into two sentences 502-507 611 Line Please explain why SH is secondary and BE+ BR are primary in OV-Line 627, Table 9-This was a typo. SH is primary. Table fixed to show SH as 538, 03 -this makes sense for the SW model but not for the OV -is it 4 primary. Table driven by slip rate? 9-4 612 Line Consider rephrasing -"The south end the rupture source is the south Lines 635-637 Text revised as suggested. 546 end of the Shoreline fault source-the intersection with the Casmalia fault." to The sooth end of the Shoreline fault source at the intersection with the Casmalia fault is the south end of the rupture source. 613 Line Figure 7-2 should be Figure 7-4? Line 675 Agree. Text revised as suggested. 582 614 Line This would read more clearly if "an" was placed before "oppositely" Line 679 Text revised as suggested 596 (shoo Id have been 586) 615 Line Please explain why some ruptures continue to the MT J and some end The linked rupture sources. which can accept floating 605 at the north end of the San Gregorio fault. earthquakes, extent to MT J and have epistemic uncertainty in Mmax. The complex and splay sources, or just the more northern ones that don't contribute to hazard, stop at the north end of the San Gregorio fault for simplicity. The complex and splay ones cannot have floating earthquakes, and this is such a low probability event that we don't include it. 616 Lines It is stated here that SW-01 through SW-03 "acknowledge uncertainty" Lines 721-726 Text revised to remove ambiguity regarding all rupture sources 630, in whetherthe set of faults rupture together, but that SW-04 through representing aleatory variability. 634 SW-07 "describe variability" in ruptures on another set of faults. This contrast in language could leave the impression that one treatment is epistemic and the other aleatory, whereas it appears that the SSC model is set up to treat both as aleatory variability. If that is the correct interpretation, please consider using more consistent language to highlights that fact. If that is not the correct interpretation, please clarifv. 617 Line Recent work has shown a strong strike-slip component on the Little No change. This component was from the Miocene per 661 Pine fault (Cannon. 2012) Onderdonk, pers. comm .. and Cannon's thesis. Recent slip apoears to be reverse COMMENT-RESPONSE LOG DIABLO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision 618 Line Figure 7-2 should be Figure 7-4? Line 767 Text revised to correct Figure number. 673 and 684 619 Line This is word-for-word the same as in the previous section -needs an Line 782 Text revised to insert *an 689 "an" before "oppositely for clarity. 620 Line No comma is needed after California Line 783, 784 No change. Response from Technical Editor: 690 Re the comma after "California': that is absolutely correct. The rule is that you use commas in pairs when the phrase or sentence continues beyond the element being set off. The same is true for the year when you give a full date. (Ex.: September 10, 2001, was the fast day of its kind in the United States.) 621 Line This would read more clearly with "that" between SWBZ" and "could" Line 790 Text revised as suggested. 697 622 Line You need a period at the end of the sentence Line 796 Text revised as suggested. 703 623 Lines Commas are not needed after "California" or "Japan". Lines 825, 826 No change. Response from Technical Editor 729. Re the comma after "California': that is absolutely correct. The 730 rule is that you use commas in pairs when the phrase or sentence continues beyond the element being set off. The same is true for the year when you give a full date. (Ex.: September 10, 2001. was the last day of its kind in the United Stales.) 624 Line This would read more clearly if you replaced "Like" with "As with" Line 830 Text revised as suggested 734 625 Table Please spell out Avenue for Wilmar Avenue fault, as it is a formal Line 846; Table 9-Text revised as suggested. 9-6 name. 6 626 Lines This is another case where the switch in language from "uncertainty" to Lines 836-839 Text revised to clarify. 740-variability" is a potential point of confusion. Please consider using 749 consistent language to keep it clear that the range of rupture sources Table (within a given Rupture Model) represents aleatory variability. 9-61Plate 9-2. 627 Line Please explain -LB and LE dip south -why is surface projection of No change As shown on Figure 7-26a, the main fault in this rupture is the 750 rupture to the north? Wilmar Avenue fault, which extends at a shallower dip beneath the Edna Valley. The LB and LE form a secondary backthrust (splay} that branches from the underlying ramp at the point of dip chanae. COMMENT-RESPONSE LOG DIABLO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision 628 Line If rupture source NE-11 models "the possibility that the Morro Bay Lines 896-904 Text revised to clarify and correct misrepresentations of what 806 basin does not represent a step-over," doesn't this represent at least might be interpreted to be epistemic uncertainty rather than some conflation of epistemic and aleatory elements in the SSC model? aleatory variablity. That is, "represents a stepover and does not represent a step-over are, on the face of it, mutually exclusive alternatives. so represent epistemic uncertainty. Yet they appear to occur concurrently in the NE loaic tree branch. Please exolain whv this is not a contradiction. 629 Line Please explain surface projection change along segments NL and FN Lines 661-664, Text included to explain the geometry of the rupture model 818 in NE-07 (Splay) 791-794, 920-923 explicitly for OV-04, SW-07, and NE-07 630 Line This results in faults that do not intersect at depth unless the Hosgri No Change. The fault sections. as drawn, do intersect. The 834 ruptures south of the intersection. proximity of the mapped traces is such that joint rupture would not be orecluded. 631 Line Please remind the reader of what the first piece was. Line 951 Text revised to clarify. 851 632 Line It would help the reader to remind them that the slip rate allocation will Line 953 Text revised as suggested. 852 ultimately provide information related to earthquake recurrence rates. 633 Line If this feature (greater slip rate) is merely the definition of "primary," Lines 982-983 Text revised to avoid the implication that the amount of slip is 880 please make that clear (otherwise it is ambiguous, because there is the criteria used to define the *primary' part of the rupture the alternative that "primary" has been defined on some other criteria source. and then this sentence becomes a rule about assigning relative slip rates). 634 Line The slip rate should be greater by an amount proportional to the ratio Line 984 Text revised to correct mistake 881-momentfarea of each part (not the moment alone). Please correct this 882 statement (although it is cleared up in the subseguent eauationsl. 635 Line Units should be specified here (e.g., the seismic moment given by Eq. Line 992 Text revised to specify units. 891 9-4 is in dyne-cm) 636 Line This sentence is confusing. The first clause appears to be just a partial Lines 1077-1080 Text revised to clarify the steps in the approach 974-restatement of a more precise statement in the second clause. Please 977 rewrite to improve clarity. 637 Line Please state the criteria that were used to conclude that the fits were Line 1109 Text added to state they were evaluated based on visual 1006 satisfactory. inspection. 638 Line As 89% of the rate is on the H-01, H-02, and H-03 models, does this Line 1125 Earthquakes on the rupture sources are modeled based on 1022 imply that these ruptures extend all of the way to the MT J? This is not magnitude PDFs presented in Chapter 10. The allocated slip Table entirely clear, as presented. rate is for the entire rupture source, including all the way to 9-8 MT J, but it is used up mostly with floating earthquakes that are distant from the DCPP. 639 Line There are eight Hosgri rupture sources. If the reference on this line to Lines 1149-1150 Text revised to clarify that the five rupture sources described 1046 "the five Hosgri rupture sources" is meant to refer only to those that involve the section of the fault adjacent to the DCPP rupture the Hosgri Fault Source, please indicate that, and in any event olease clarify the statement. 640 Line It is 54% not 65% as stated in Explanation column Line 1153 (Table Text has been added to clarify that H-04 and H-05 are also on 1048 9-9) the Central strand and contribute (0.06 +0.5 = 0.11 ). Thus the Table 054 + 0.11=0.65. COMMENT-RESPONSE LOG DIABLO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision 9-9. H-01 (Centra I strandl 641 Lines If the location is aleatory, then the relative frequency of each location Line 1164-1175 The following paragraph outlines the geologic and geomorphic 1055-must be defined by the Tl Team. Please inform the reader how the data used to inform the values selected by the Tl T earn to 1058 relative frequencies (fractions) were assessed by the Tl Team. What represent the aleatory variability in the location of future types of data were considered? What was the role of different types of ruptures. Aleatory variability is expressed as the slip rate data (e.g., geomorphic expression, analogs, indications of vertical allocated to each rupture source (i.e .* the percentage, or component of slip)? The reader needs to know that this is an expert fraction of the entire slip rate). assessment process (i.e., the numbers don't just fall out of the calculations), but the expert judgments are informed by a variety of data constraints. 642 Line Please consider replacing "not as continuous a trace" with -a Line 1166 Text revised as suggested. 1062 discontinuous trace 643 Lines What if one or more strands were more strongly strike-slip (ie., Line 1168-1169 No change to text. Review has a good point. but the 1064-different horizlvert ratios)? How does this compare with the offset assumption is stated that we use the vertical separation as a 1067 channel data from LESS Lines 1215-1216? proxy. The range in slip rate values for each source (low, middle, high) covers the possibility that our proxy is misleading. 644 Line "The plant" is elsewhere called "the DCPP." Please consider keeping Line 1181 Text revised to replace 'planf with 'DCPP' 1077 the terminology consistent. 645 Line Please consider adding two letter segment after "western reach of the Lines 1181-1183 Text revised to include two-letter codes to clarify the segments 1077 Hosgri fault source' (HB) so it not confused with HW involved in the rupture. 646 Line If "relative merits of this configuration compared to others" means Lines 1192-1194 Text revised to better explain 1087 compared to other options for filling in the limited Shoreline Fault slip budget. please add that clarification. Otherwise, add some explanation of what the phrase means in this context. 647 Line It would be useful to explain the difference between the 54% allocation Table 9-9 and Text added to Table 9-9 (see response to Comment 640 and to 1090 and the approximately 65% estimated based on vertical separation. lines 1196-1199. last sentence of Section 9.2.3.1 to explain why the 54% and Please explain whv these values are not in conflict with each other. 65% values are not in conflict with each other.. 648 Line The Hosgri slip rate CDF seems to have been presented in Section Line 1209 and Minor edits made to check Section and figure references. 1097 8.3.7 (not 8.3.3). Please check and correct if necessary. Also please Figure 9-10 Discrete" removed from the figures. The black lines are indeed explain why the Hosgri slip rate CDF shown as a solid black curve in discrete distributions, but the large sample size (10,000) and Figure 9-9 is called a "discrete Hosgri CDF' when it appears in the the GDF makes them look continuous. In text, discrete only figure to be a continuous function, and seems to be presented as a used for the logic tree combinations. continuous CDF in Section 8.3.7 (e.g., Figure 8.3-20). In what sense is it "discrete" (that term would seem more appropriate for the logic-tree CDF. and the term is used in that sense on Line 1101)? 649 Line Please replace "it is a satisfactory" with "it provided a satisfactory." Line 1207 Text revised as suggested. 1099 COMMENT-RESPONSE LOG DIABLO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision 650 Lines The phrase "discrete CDF of all logic tree branch combinations and Lines 1209-1210 Text revised to clarify meaning. 1101-their weights" is not clear. Please clarify (e.g., it would be clearer to Line 1286 1102, say something like '"discrete CDF of all weighted logic tree branch Lines 1 3 76-1377 Lines combinations" if that is the intended meaning). 1165-1166. and Lines 1243-1244 651 Line It is understood that the '"preferences'" identified in this paragraph and Lines 1239-1272 Text added to state judgments behind the allocation amounts. 1130 the next two paragraphs are implementing the two principal bases for the allocation discussed in the paragraph starting with Line 936. However. the reader needs to have a better idea of how the application of the bases is applied in each case discussed in these three paragraphs. For example, why does the Tl Team have a preference that the Shoreline fault slips either along or as part of the Hosgri fault? Is it the least complex topology for accommodating slip? More consistent with analogs? Likewise, in the next paragraph. why is 92% allocated to reverse-only rupture sources? The technical bases for the allocation amounts need to be given, especially because they are based on expert judgments. It is comparable to providing technical justification for the weights assigned to logic tree branches: there needs to be some basis given in the text or the decision will look arbitrarv. 652 Lines Please consider changing sentence to: The remaining slip rate is Lines 1261-1264 Text revised as suggested. 1134-allocated approximately evenly between the shorter (OV-03) and 1136 longer (OV-04) complex ruptures whereby the Shoreline fault source ruptures as part of multi-fault complex rupture involving both strike-slip motion and reverse or reverse obliaue motion. 653 Line Why is OV-05 at the top of the list in the legend? Figure 9-11 This is a typo in the figure. Explanation changed to correctly 1161 state H-05 for the top of the list. Figure 9-10 654 Line For clarity, spell out numbers in this paragraph as the get lost with the Lines 1215-1221 Text revised to list in bullets for clarify 1173 other numbers. Lines 1294-1301 655 Line H-05 -This should be 23% of Shoreline fault slip budget and then table Line 1307, Table Text revised to correct a typo (23% is correct value for H-05. 1185 for the SW model will sum to 100% 9-13 656 Line Please explain -SW-06 source of 0.086 is 100% of total budget for Line 1307, Table Footnote added to table to explain that the Los Osos is a 1185 Los Osos source. but is listed at 45% 9-13 backthrust in the SW model and is not fully seismically coupled. Thus the 45% total signifies 45% of the total slip rate is released seismoaenicallv; the rest bv other mechanisms. 657 Lines 0.09 mm/yr is not 45% of 1.9 mmlyr, it is 4.5%. Is there a typo here? Lines 1 340-1342 Text revised to correct a typo (1.9 mm/yr was corrected to 0.19 1215-Please clarify. mm/yr) 1216 COMMENT-RESPONSE LOG DIABLO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision 658 Line "The total slip rate of less than 0.09 mm/yr is approximately 45% of the Lines 1340-1342 See responses to comment numbers 656 and 657; text and 1215 geologic rate of slip of 1.9 mm/yr attributed to the Los Osos fault in the and Table 9-13 table modified for clarity. SW Model (Section 8.5)." Total is listed as 0.09 for Los Osos in Table 9-13 -please make consistent 659 Line Please expand the technical argument supporting the 0.45 coupling Lines 1345-1359 Text added to provide the rationale for the coupling values. 1217-coefficient for the Los Osos Fault in the SW model, and the 0.57 Lines 1435-1447 Examples of structures where structural growth probably 1220, coefficient for the San Luis Bay Fault in the NE model. especially any occurred seismically similar to what the Tl T earn en vis ions for and empirical support. For example, if there are geologic analogues that these backthrusts. 1290-favor decoupling of approximately this magnitude, please cite. If this 1297 value is a source of significant hazard sensitivity, please explain how the SSC model accounts for uncertainties in the coupling coefficient. If it is not a source of significant hazard sensitivity, please state that and cite the hazard sensitivity analvsis that establishes that fact. 660 Line Field et al.,2014, does not appear in the list of references. Line 1345 Citation changed to Field et al. 2013. 1220 661 Lines Spell out numbers in this paragraph as well, for clarity. Lines 1384-1391 Text revised to show as bulleted list. 1251-1256 662 Line "Combined, these rupture sources accommodate approximately 0.09 Line 1397. Table Footnote added to table with explanation for discrepancy 1290 mm/yr of seismogenic slip rate on the fault, or approximately 57% of 9-15 between total slip rate allocated to rupture sources and the total 0. 16 mm/yr slip rate attributed to the San Luis Bay fault in the geologic slip rate on the fault source. NE Model (Table 9-15: Section 8.6)." Allocated 0.092 total slip for San Luis Bay Fault in Table 9-15 not 0.16 mm/vr -please make consistent. 663 Lines Consider including the slip rate CDF information in a caption or the Figures 9-10 to 9-See Comment 671. Edits made to figures. 1313-notes for each of these types of figures. 15 1314 664 Line Hosgri +SW Models and Hosgri +NE models do not add up to 100% Line 1484. Table Typo corrected. 91 % of total now shown for top row on all 1333 as shown in Table 9-17. 9-17 three models. Table 9-17. 665 Line Might want to add supporting arguments why this higher-than-target Lines 1510-1514 Text added to cite Workshop 1 and chapter 14. 1356 slip rate on the Hosgri fault north of the DCPP will not meaningfully affect the hazard results for the DCPP. 666 Lines Please complete these citations. Lines 1518 and Citations checked and are complete 1406, below 1473, and 1477 667 Table Please clarify why the western reach of the Hosgri fault has a negative Lines 1497-1500 It shows slip rate transferring westward from the main Hosgri-9-17 slip rate. Cross-check this with lines t 344-1345 and clarify what/how it San Simeon fault zone to the Piedras Blancas via the western COMMENT-RESPONSE LOG DIABLO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision was done. reach. Text provided and cross-reference to section 5.2.1. 668 Figure Is it really negative vertical offset? Subsidence? Plus, technically, Figure 9-2 Points taken, but no change. Figure is directly from Wesnousky 9-2 offset is a strike-slip term. (2008); no reason to extensively modify this other citation, as it's not germane to this study 669 Figure The arrow showing the northern extent of rupture in Yeats' figure is Figure 9-3 No change. The arrow is meant to point to the thicker black line 9-3 misleading, as both the 1940 and 1979 ruptures extended north of this that shows the extent of the 1979 rupture. It is not meant to point. show the northern extent of the rupture. 670 Figure The note on the figure states that two dominant fault zones are shown Figure 9-8 The phrase '(thick black lines)' has been deleted from the note. 9-7 by thick black lines. It is confusing that, for the most part, these black The following sentence names the two dominant fault zones. lines are covered by green or yellow lines showing other attributes (also true in Fletcher et al.'s published version). Please clarify this issue in the fiaure note. 671 Figure An explanation is needed with the figure that the individual rupture Figures 9-10 to 9-Note added to figures as suggested 9-11 source CDFs sum to the Lognormal SLB CDF 15 672 Figure The Hosgri slip rate CDF (solid black curve) in panels a and c of Figures 9-10 to 9-Word Discrete removed, even though this is technically correct 9-9 Figure 9-9 is labeled "Discrete Hosgri GDF." But it appears to be a 15 (discrete CDFs from the Monte-Carlo simulations -10,000 through continuous CDF, and that is also the impression left by Section 8.3.7. make a smooth GDF) 9-14 Please clarify or correct the figure label. Same comment applies to the CDF plots for other faults in Figures 9-10. 9-11, 9-12, 9-13, and 9-14. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT PPRP COMMENTS AND Tl TEAM RESPONSES, CHAPTER 10 Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision CHAPTER 10-Magnitude Distribution Models 673 Line 7 Isn't the shape actually defined by the magnitude PDF. while the MFD Lines 14-15 and We are using the magnitude PDF as generic shape. Shape is actually incorporates the seismic moment rate? 27-28 modified based on Mchar, etc. values. The term MDM, which was incorrectly used in this paragraph and latter sections of the report has been corrected to *maonitude PDF(sJ' 674 Line 40 Might qualify this statement to indicate "earthquake magnitudes that Line 47 Text revised to add qualifying statement as suggested. give rise to significant ground motions." It might be argued that the historical/instrumental record provides a pretty good basis for assessino the rates of M3 earthouakes. 675 Line 50 Within the WAACY box, doubly-tuncated should read doubly-Line 57 Text revised to correct spelling of 'truncated'. According to Table truncated. Technical Editor. a hyphen is not needed where adjective ends 10-1 in .. ly. 676 Line Please state what lengths would typically be hypothesized to be Line 66 This sentence has been deleted. The discussion is reserved 61-62 characteristic, and provide justification or a reference that does so. Or, for later in the chapter (Section 10.2.3) if that discussion is provided elsewhere in the report. please provide a specific {chapter, section number) reference. 677 Line 79 This sentence appears to be a direct contradiction of sentence Lines 83-85 You are correct. They are aleatory in the model beginning on line 520. Please rectify this apparent contradiction or The text was revised to clarify this. explain why it is not actually contradictory. 678 Line 84 Here and elsewhere in the text. this should be termed the Lines 91, 98, Text revised as suggested. "characteristic earthquake model'". 109,444, 483, 524, 656 Tables 10-2 and 10-4 Figures 10-1 and 10-4 679 Line Please improve this explanation of conditions for use of the Line 103 This sentence has been deleted. The discussion is reserved 97-98 characteristic PDF, because the explanation seems more or less for later in the chapter (Section 10.2.3) circular without a quantitative statement of the rupture-source length criterion. 680 Line The word "bur is a source of confusion, because it suggests that the Line 109 Text revised as suggested. 104 second clause is going to qualify the first, whereas the second clause actually seems to directly reinforce the first. Please check whether the intent of the sentence would be more efficiently communicated if the word were chanoed to and."' 681 Line And what are the disadvantages? (Difficulties in assessing the various Lines 128-t 33 Text revised to clarify that the possible disadvantages are that 127 parameters?) the W AACY model contains many parameters and has not yet been implemented in previous PSHAs. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 682 Line The phrase "the logic tree of W AACY parameters values and weights Lines 156-158 Text revised to clarify. 150-are correlated with" is unclear (e.g., does it mean "the parameters 151 values and weights in the logic tree are correlated with"?). Please rewrite the sentence to clarify its intended meaning. 683 Line Suggest a section title that is more specific to Mchar and Mmax. Line 159 Text revised as suggested. 154 Otherwise. the section could refer to the selection of the particular type of maanitude to be used (Mw, Ms, etc.). 684 Line Check spelling on paleoseismic. Line 186 Spelling corrected. 183 685 Line Please consider rephrasing -This prediction is supported to an extent Line 192 Text revised . 197 by empirical data. which include no step-overs wider than 4 km (Wesnousky. 2008) or 5 km (Lettis et al., 2002), but not in detail, as Wesnousky (2008) found that among step-overs less than 4 km wide. there was no relationship between step-over width and likelihood of arresting rupture. 686 Line The phrase "energy in rupture momentum" is not physically Line 207 The phrase *energy in rupture momentum' has been change to 204 meaningful. In fact. at least in the limit of a very narrow process zone, 'kinetic energy during rupture* a rupture front does not carry any momentum at all. in the sense that rupture speed can respond instantaneously to changes in stress. frictional resistance, etc. Please substitute more aoorooriate lanauaae. 687 Line Soften -replace indicate with suggest Line 210 Text revised as suggested. 208 688 Line This would read more clearly with a comma after "lengths". Line 210 Text revised as suggested. 208 689 Line "where fault traces more abruptly bend" would read more clearly as Line 214 Text revised as suggested. 212 "bend more abruptly". 690 Line Please consider replacing "than where they are less pronounced" with Lines 211-216 Text revised to clarify. 214 "where offsets or bends are more pronounced" 691 Line "The maximum M ... , value for all Primary fault sources bypasses Lines 228-231 Text revised to clarify that all Rupture Models include rupture 222-essentially all proposed segment boundaries." Are these wall to wall sources that involve Primary faults that link with Hosgri, San 223 ruptures? Please explain. Gregorio, and San Andreas faults to MT J .. 692 Line Please change "materially" to substantially -remove any material Line 247 Text revised as suggested. 239 properties confusion 693 Line Replace "Points" with Features Line 255 Text revised as suggested. 247 694 Line Please check for missing verb on this line. Lines 293-297 Text revised to address verb issue 286 695 Line Delete "and" between intersection and had for clarity Line 294 Text revised as suggested 287 696 Line consider replacing "considered lesser in degree" with Line 304 Text revised as suggested. 296 "less well develooed" COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 697 Line This line is unclear. What are alternates? Please check whether the Line 328-331 Text revised to clarify. 300 word "alternatives" (rather than "alternates") better corresponds to the intended meanina on this line. Or is it alternative traces? 698 Line Faults joining? The activity of faults that intersect the main trace is Line 313-314 Text revised to clarify 303 low?? Please clarify. 699 Line Replace "short" with finite Line 318 Text revised as suggested. 307 700 Line Please make it clearer what is meant by "to define the limits of soft Lines 323-328 This sentence was changed to emphasize that the purpose of 314 segment boundaries along fault sources." allowing ruptures to float is to account for uncertainty in precise locations and sizes of potential segment boundaries. This simplification is justified because this is a site-specific SSC model. 701 Line Please insert capture in front of magnitude Line 340 Text revised as suggested. 330 702 Line Please check whether the word "given" (rather than provided") would Line 341 Text revised as suggested. 330 better convey the intended meaning. 703 Lines The range of magnitudes predicted by the alternative rupture lengths Lines 344-347 Sentence rearranged as follows to clarify the meaning 333-considered using any single magnitude-scaling relation is much The range of magnitudes predicted by any single magnitude-336 greater than the range of magnitudes predicted for any single rupture scaling relation for the alternative rupture lengths considered in length (or area) from a suite of magnitude-scaling relations. This the Diablo Canyon SSC model is much greater than the range sentence is difficult to parse. Please rewrite and clarify this statement. of magnitudes predicted for any single rupture length (or area) from a suite of maanitude-scalina relations. 704 Line Delete extra do" for clarity. Line 344-34 7 Text modified to eliminate typo .. 340 705 Line Please explain why the SSC forward-modeling approach implies Line 347 Reference to the implications of magnitude scaling 340 weaker sensitivity to magnitude-area scaling compared with the relationships for UCERF 3 is removed from this discussion. inversion approach of UCERF3. The UCERF 3 analysis is not what guides our approach to characterizing magnitude uncertainty. 706 Line "This review included other evaluations of alternative scaling relations Line 353 Text revised as suggested to delete sentence. 347 and their relative merits for use in seismic hazard analysis (e.g., WGCEP, 2003; Shaw, 2013a; Stirling et al . 2013)." Redundant -olease remove. 707 Line Use a comma after SSC model, rather than a colon. Line 364 Text revised, but semi-colon used based on recommendations 360 of technical editor 708 Line "strike-slip Hosgri fault, lesser but significant" is unclear. Perhaps Lines 365-367 Text revised 361 insert whereas" before lesser? 709 Lines Abbreviated HB02 -please add "as so it reads "abbreviated as HB02" Line 371-373 Text revised as suggested; other abbreviations added as well 367, 368, 369 710 Line Abbreviated as??? How is this designated? Line 375 Text revised to specify abbreviation as requested. 370 COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 711 Line EB02 should be EB03? Line 381 Text revised to change to EB03. 376 712 Lines HB08 data set looks more comparable with YM11 than NGA-W2 data Lines 383-387 Text revised to clarify that HB08 does look more comparable 378-set? with the YM11 dataset, instead of the NGA-W2 dataset as was 380 previously written. 713 Line EB02 should be EB03? Line 390 Yes. Text revised to correct. 385 714 Line Here you use a 12 km depth for characteristic ruptures, but the implicit Lines 445-448 Text is revised to clarify that characteristic earthquakes are 438 assumption is that these only apply to shorter faults, and not the interpreted to occur on any of the Primary or Connected fault Hosgri. Perhaps it would be good to make this clarification here rather sources, and that the rupture width for all characteristic than below (lines 451-453). earthauakes is 12 km. 715 Line The argument in this sentence appears to be that it is acceptable to Lines 462-468 A reference to sensitivity analyses presented at Workshop 2 447-under-represent aleatory variability of magnitude because epistemic testing fault length is provided. 450 uncertainty is broadly sampled. Please justify quantitatively why this The text is modified to clarify that the Tl Team judges that the tradeoff is acceptable (for example, this might be done by referencing wide range of aleatory variability built into the model through available hazard sensitivity analysis). the use of numerous rupture sources in addition to the epistemic uncertainty incorporated through consideration of alternative estimates of Mmax justify this simplification. 716 Lines Please provide supporting evidence for the stated hypothesis that only Lines 445-448 Text revised to cross reference to Section 7.2.1. where 451-the largest earthquakes rupture with depth greater than the depth Line 453 transient deepening is postulated to be generated by high 455 limits inferred from background microseismicity. strain rates of the main shock strain rate. 717 Line The wording "depth of crust derived from proxies such as the D90 or Line 446-453 Text revised to correct. These concepts are more fully 454 D95 values" implies incorrectly that D90 or 095 can be interpreted as discussed in Section 7.2. 1; the revised text refers the reader to proxies for the depth of the crust. They are proxies for depth of the this section of the report. seismogenic zone, and perhaps for the brittle-ductile transition depth. Please make aonrooriate chanaes. 718 Line Please state the technical justification for selecting M 7.3 as the Lines 452-457 Text revised to clarify the cut-off magnitude (M 74) used (ie. 458 threshold for rupture deeper than 12 km. >the largest Mchar earthquakes included in the model) The Tl Team judges that characteristic earthquakes should adhere to the depth limits indicated by consideration of 090 and D95, and the presence of an apparently unfaulted slab. Only the rare larger events are interpreted to rupture beyond that depth. These analyses are more fully discussed in Section 7.2.1; the revised text refers the reader to this section of the report. 719 Line The figure uses 130 km. Please make consistent. Figure 10-4 The figure is corrected. 468 720 Lines This aleatory variability is considered by the Tl Team to represent a Lines 485-490 Text revised to clarify. 471-combination of magnitude variability given the rupture area and rupture 474 area variability of the characteristic earthquake given the approximate definitions of the soft segmentation points used to define the characteristic ruptures. Please rewrite this with one less "given", as it is difficult to parse. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 721 Line Don't capitalize The Line 496 Sentence modified to eliminate typo .. 480 722 Lines This sentence is confusing -please rewrite for clarity Lines 501-505 Text revised to clarify. 485-489 723 Line Was any consideration given to the manner in which the exponential Lines 507-514 Text revised to cite other studies that showed the exponential 490 relationship would need to be implemented? Studies of other active model does not provide a good fit to seismicity or paleoseismic faults show that the observed seismicity occurring within a narrow data. zone along a fault is not compatible with the exponential shape of the recurrence curve unless a very large Mmax is adopted (e.g., Hecker et al. 2013). Was there any attempt to examine the recurrence distribution along the Hosgri fault or other faults based on seismicity? The same arguments made below between the exponential and WAACY model with respect to repeated slip at a point could be made here to justify the zero weighting of the exponential model for Category A rupture sources. 724 Line 130 km in the figures -please correct to a common value. Figure 10-4 Figures were updated to clarify that all type A rupture sources 500 are less than 100 km. Type B rupture sources are greater than 100 km 725 Line Please consider whether the challenges to the exponential PDF Lines 541-544 Agreed. Good suggestion. UCERF3 tried unsuccessfully to 504 identified by UCERF3 (Field et al., 2014) constitute another factor (in implement GR fault MFDs. They found that the fault system addition to the Hecker et al analysis) in the Tl Team's judgment to give was too characteristic to make them work. that PDF substantially lower weight than given the WAACY PDF. Text has been modified to cite Field et al. (2014) who do acknowledge the Hecker et al. (2013) results and issues with G-R for faults. 726 Line Please insert paleoseismic before data Line 531 Text revised as suggested. 504 727 Line Replace "confidence" with determined Line 533 Text revised as suggested 506 728 Line The inclusion of Figure 10-5 with virtually no accompanying Figure 10-5 An explanation has been added to Figure 10-5 509 explanation in the text or caption is extremely confusing. The figure makes reference to undefined "Group A," "Group B", and "Group C". and the reader naturally associates these with the "Category A." "Category B," and "Category C" magnitude PDF categories that have just been introduced in the text at this point (only to eventually discover that there is no such connection). Please either make some use of the fiaure, with a full explanation, or delete it. 729 Line Please define "available data." There is an implication that these Line 541 These endorsements of the exponential model did not consider 514 endorsements of the exponential distribution for faults were made after the final version of Hecker et al. (2013) because they pre-date giving due consideration of the Hecker et al. data regarding slip per that paper, but they did attempt to reconcile paleoseismic data event. What types of data were considered by these authors and is ii and seismicity data near faults. Parsons and Geist point out possible that they would endorse the W AACY model over the that reconciling the two datasets for the southern San Andreas exponential model if they had considered all "available data" presented fault is achieved by either ( 1) considering seismicity within a by Hecker et al.? volume around a fault 10s of kilometers wide, or (2) considerina temooral chanaes in seismicitv rates, oerhaos due COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision to regional effects such as stress shadows that follow major earthquakes. Text modified to describe the data tvoes considered. 730 Lines A potential criticism of the maximum magnitude model for hazard No change No change required. While we acknowledge that this may be a 516-analysis is that smaller magnitudes are not provided for in the concern in more traditional SSC models where the maximum 517 distribution for each rupture source. It could be noted that the use of magnitude model is given weight as the appropriate model for the model in conjunction with seismic source zones to account for a single fault source. in this model it is being applied to only smaller magnitude seismicity ensures that all magnitudes smaller than certain rupture sources, on a particular fault source. In all the maximum are included. cases, the fault source also produces small magnitude earthquakes as part of other rupture sources. Adding text to explain how smaller magnitude events are accounted for in this section would be more confusing than helpful. 731 Line The statement about Category C rupture sources is that "aleatory Lines 545-556 Text revised to clarify that magnitude variability for Category C 520-magnitude variability is introduced by involving more than one rupture sources is aleatory. 522 scenario" with defined relative frequencies. But Line 79, also in regard to Category C rupture sources, states that "epistemic uncertainty is incorporated by considering alternative scenario earthquakes." Please explain why this is not a contradiction, or make changes to provide a consistent description of the intended treatment of variability in the Category C rupture sources. 732 Line Insert model after UCERF3 Line 570 and 571 This sentence and preceding one were revised accordingly. 536 733 Line "at random" may read better as "randomly" Line 591 Text revised as suggested. 557 734 Line "the left end"?? Left end of what? One end? South or north end? Lines 599-604 Text revised to clarify that left and right are respective of the 568 There is no "left" or right ends of a fault without a reference frame. *observation point' The descriptions 'left' and 'right' are left purposely generic to avoid confusion with faults of any specific direction. 735 Line Same comment. "on the right" could read "towards one end" Lines 599-604 Text revised as noted above. 570 736 Line "of 60 km long" -this would be clearer with a hyphon between km and No change No change required based on following recommendation of 572 long Technical Editor Note that we don't hyphenate this kind of compound when there is an abbreviation-as explained in the Chicago Manual of Style. 737 Line Please write text and one or more equations explaining precisely what Figure 10-6 Equations have been added to clarify what is being plotted, 574 quantity is plotted in Figure 10-6 and how that quantity is applied to the Lines 590-663 and how Figure 10-6 relates to Figure 10-7. Briefly, 10-7 is magnitude PDFs (e.g .. what is a "reduction rate"-the term "rate" logarithmic. The y-axis on Figure 10-6 has been changed to implies it has units, yet from the range of values in the plot, it appears 'Geometric reduction rate' to be dimensionless; assuming it is actually a dimensionless adjustment factor, what quantity does it multiply to implement that adjustment? How do you go from the curve in Figure 10-6 to the results in Figure 10-7; how does the quantity in Figure 10-6 combine with the factor LIL,?)_ COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 738 Line Please give a precise definition of "geometric reduction** and how this Lines 590-610 Edited in the course of reply to comment 737. 584 term is distinguished from, and related to, the terms "rate reduction" labeling the axis in Figure 10-6 and "reduction rate" introduced on Line Figure 10-6 574. 739 Line It is stated on this line that the exponential model leads to a point MFD Lines 638-641 Text revised to clarify that once they reach a certain size, the 592 that has a "gentle upward deflection" for larger magnitudes. There is ruptures cannot float beyond the end of the fault. This no upward deflection on the point MFD (blue) curve in Figure 10-7a effectively decreases the geometric reduction factor. "upward (nor is ii clear why one would be expected). Please clarify deflection" was erroneous. For the exponential model, this effect is a downward deflection. The text has been revised to clarify this. 740 Line Please explain the phrase **arithmetic sum by magnitude Lines 662-663 Revised text to explain the slip rate matching and clarify the 611 next step of summing across rupture sources. 741 Line Please check whether the phrase "alternative earthquake scenario Lines 677-678 Text was revised to delete the word 'alternative' from the 623-magnitudes and frequencies for complex and splay rupture sources" phrase 'alternative earthquake scenario'. As noted in the 624 actually communicates what is intended. If so. please explain how response to Comment 677, the earthquake pairs represent "alternative" scenarios can be reconciled with the sentence beginning aleatory variability (i.e., both occur with some estimated on Line 520 that says "Aleatory magnitude variability is introduced by relative frequency). involving more than one scenario earthquake pair, whereby the relative frequency of the scenario earthquake pair is defined." The scenarios are either "alternatives" or they occur collectively with some "relative frequency," and it is not clear how both statements can be correct. 742 Lines Figure 10-4 shows 130 km as the break between category A and B Line 691 The figure was corrected to show that the break is 100 km. 636-rupture sources. 637 743 Line It is not clear what is meant by "alternative aleatory logic tree branch . Lines 706-712 Text has been revised to clarify . 653 values." Table 10-5 refers to "scenario frequency, suggesting that all of the listed scenarios occur on a single logic-tree branch and represent aleatory variability, not mutually exclusive alternatives. So please explain what the "alternative" logic tree branches are in reference to Table 10-5. The confusion about the status of the Category C rupture sources seems to be systemic in this chapter: Note the related apparent contradiction between sentences beginning on Line 79 and Line 520. and the related issue on Line 689 (with reference to Table 10-81 and Line 722 {with reference to Table 10-11 l. 744 Line Please explain how the assessment of the relative frequency of the Lines 710-712 A very crude magnitude scaling was adopted, in which large 655 scenarios relates to the shapes of the MFDs. What was the thought magnitude scenario events are judged to occur less frequently process used by the Team? than smaller magnitude scenario events. Text modified to clarify 745 Line "favors" instead of "favored? Lines 710-712 Word 'favors' was deleted in revised text in response to 658 Comment 7 44 .. 746 Line Same as comment for Line 623 Please check whether the phrase Lines 723-727 Text was revised to delete the word 'alternative' from the 670-71 "alternative earthquake scenario magnitudes and frequencies for phrase 'alternative earthquake scenario'. As noted in the complex and splay rupture sources" actually communicates what is response to Comment 677, the earthquake pairs represent intended. If so. please explain how "alternative" scenarios can be aleatory variability (i.e

• both occur with some estimated COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision reconciled with the sentence beginning on Line 520 that says "Aleatory relative frequency). magnitude variability is introduced by involving more than one scenario earthquake pair, whereby the relative frequency of the scenario earthquake pair is defined. The scenarios are either "alternatives or they occur collectively with some **relative frequency, and ii is not clear how both statements can be correct. 747 Lines II would be helpful to indicate where on the figures these segment Line 730 Text revised to cross reference to Plate 9-2 for maps showing 672-boundaries can be found. Perhaps add a column to the table what Tables 10-6, 10-9, locations of boundaries. 673 makes reference to the applicable figure. and 10-12 Tables 10-6, 9, and 12 were also modified to reference the fiqures that show how the segment boundaries were used. 748 Line Why is LC, HN, HD not a tier 1 as there is observed a pronounced Table 10-6, LC, This point is a first-tier boundary in the OV Model (although it is 674. difference in sense and rate of slip between the two faults? HN, HD boundary only a second tier boundary in the Hosgri MOM). The table has Table been corrected to reflect this. 10-6. 749 Table "South end of Little Pine fault"?? This fault strikes southeast -please Table 10-6, LP Text revised as requested. 10-6 correct the strike. 750 Table Different slip rate or difference in slip rate?? Please fix. Table 10-6, LO, Text revised as requested 10-6, LE LO, LE box. 751 Line Only double asterisk for SE** Table 10-6, SE Double asterisk was inadvertent. It has been removed 677 752 Line Suggest including "Rupture Source Magnitude PDF Category (rather Tables 10-7, 10-Revised heading to be "Magnitude PDF Category". 687. than just "Category") in this heading to remind the reader. 10, and 10-13 Table 10-7 753 Line Please provide some discussion of how the weights for Mchar and Lines 741-743 A discussion was added to the introductory text that precedes 687. Mmax were assessed. Lines 784-790 the table describing how the weights for Mchar and Mmax Table Lines 828-834 were assessed. 10-7 754 Line Same comment as for Line 653: It is not clear what is meant by Lines 750-755 Text has been revised to clarify. 689 "alternative aleatory logic tree branch values," given that Table 10-8 appears to describe relative frequencies, not mutually exclusive alternative models. Please explain how to interpret Table 10-8 in terms of alternative logic tree branches, and how that is consistent with the aleatory nature of the variability implied by the term "relative freauencv." 755 Line This would read more clearly with a comma after sources". Line 764 Paragraph was modified as part of technical edit 700 756 Line Same as comment for Lines 623 and 670: Please check whether the Lines 769-770 Text was revised to delete the word 'alternative' from the 702-phrase "alternative earthquake scenario magnitudes and frequencies phrase 'alternative earthquake scenario'. As noted in the 703 for complex and splay rupture sources" actually communicates what is response to Comment 677, the earthquake pairs represent intended. If so. please explain how "alternative" scenarios can be aleatory variability (ie .. both occur with some estimated reconciled with the sentence beginning on Line 520 that says "Aleatory relative frequency). maanitude variabilitv is introduced bv involvina more than one scenario COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision earthquake pair, whereby the relative frequency of the scenario earthquake pair is defined." The scenarios are either "alternatives" or they occur collectively with some **relative frequency," and ii is not clear how both statements can be correct. 757 Table "Postulated South end" -south should be lower case. Also, shouldn't SE box in Text revised as requested. 10-9, this be southeast end, as the fault strikes NW-SE?? This comment Tables 10-3, 10-6, SE .. also applies to other tables with identical verbage, such as Table 10-10-9, and 10-12 box 12 758 Table Same comment as above -the Little Pine fault has a NW-SE strike, so LP box in Text revised as requested 10-9, this should read the southeast end. This comment also applies to other Tables 10-6, 10-9, LP box tables that use identical verbage, as in Table 10-12 and 10-12 759 Table SH-HB marked difference in slip rate -Tier one? Tables 10-6, 10-9, Given the significant change in slip rate this property suggests 10-9 and 10-12 SH-HB it may be a first tier boundary. However, evidence for deflection of the primary Hosgri trace, or localized uplift or subsidence around this boundary is weak, suggesting it may be a second tier boundary. or a borderline case. In the SSC model. this boundary is treated both ways: many rupture sources end at this boundary. but some include characteristic rupture lengths that bypass it The tables have been modified to reflect this. 760 Table The hazard implications of the MS scenario that includes the Hosgri No change The hazard implications of this rupture source are considered 10-11. will need to be considered in Chapter 14. In particular, the implications in Chapter 14. Although preliminary sensitivity analyses (e.g .. SW-04 of assigning a 10% relative frequency should be discussed. Gregor, 2012) suggest that considering very large magnitudes box will tend to reduce hazard at the DCPP, the Tl Team judges it to be appropriate to assign a 10% frequency to the MS scenario for this rupture source. Given the low slip rate assigned to SW04, and the amount of moment consumed by a MS event, this event would be extremely rare. No change to the text of Chapter 10. 761 Table Fault is capitalized here, and small case elsewhere. Be consistent Table 10-12, SA Text revised as requested 10-12, box SA box 762 Table Please add fault after Wilmar Avenue, for clarity. Table 10-12, WB, Text revised as requested 10-12, SS, SF box WB,SS, SF box 763 Line There isn't any "description" provided in the table. Line 779 Correct. We have revised the text to state that the table 713 "provides" an assessment. .. 764 Line Please explain surface projection pattern for NL? Figure 10-30 The downdip projection of the Nipomo Lineament was drawn to 717 be truncated by a moderately to steeply east-dipping West Figure Huasna fault. This truncation was not used in Magnitude 10-30. scaling relationships for estimating magnitudes. The faults farther to the southeast are drawn to be more generalized. Given the distance and small hazard contributions of these faults, the Tl Team iudaes that these simolifications are COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision justified. 765 Line Same comment as for Lines 653 and 689: It is not clear what is meant Lines 794-797 Text has been revised to clarify. 722 by "alternative aleatory logic tree branch values," given that Table 10-11 appears to describe relative frequencies, not mutually exclusive alternative models. Please explain how to interpretTable 10-11 in terms of alternative logic tree branches, and how that is consistent with the aleatory nature of the variability implied by the term "relative frequency." 766 Line Same as comment for Lines 623, 670 and 702: Please check whether Lines 810-814 Text was revised to delete the word 'alternative' from the 737-the phrase *'alternative earthquake scenario magnitudes and phrase 'alternative earthquake scenario'. As noted in the 738 frequencies for complex and splay rupture sources" actually response to Comment 677. the earthquake pairs represent communicates what is intended. If so, please explain how "alternative" aleatory variability (i.e., both occur with some estimated scenarios can be reconciled with the sentence beginning on Line 520 relative frequency). that says Aleatory magnitude variability is introduced by involving more than one scenario earthquake pair, whereby the relative frequency of the scenario earthquake pair is defined." The scenarios are either "alternatives" or they occur collectively with some "relative freciuencv:* and it is not clear how both statements can be correct. 767 Line SH-HB Tier one segment boundary? Table 10-12 Same response as above (Comment 759). 742 The text is revised to clarify that this boundary is a borderline Table case and it is treated both ways. 10-12 768 Line No asterisk in Table 10-12 Table 10-12 Comment appears to be in error. 744 There are asterisks after the following table entries: SH,SS, BR NE-03. WB,SS,SF NE-07* LV,LB NE-07* LC, HN, HD NE-08* 769 Line Figure 10-36. Please explain -if the dip of the Los Osos is 60" -why No change The dip of the Los Osos changes along strike. See Figures 7-752 doesn*t the surface projection of the rupture parallel the fault? 26 and 7-27 that show the western part (LM) dips 50° and the eastern LV) dips so*. 770 Line Same comment as for Lines 653, 689:, and 722: It is not clear what is Lines 813-814 The word "Alternative" has been deleted. 756 meant by "alternative aleatory logic tree branch values." given that Lines 838-843 Table 10-14 appears to describe relative frequencies, not mutually exclusive alternative models. Please explain how to interpret Table 10-14 in terms of alternative logic tree branches, and how that is consistent with the aleatory nature of the variability implied by the term "relative frequency." 771 Line Tables 10-14-some descriptions (Faults) have main or splay written Tables 10-8, 10-The tables have been edited to clearly distinguish which fault is 762 in column but not all -please make consistent for all tables 11,10-14 main (or primary) and which is splay (or secondary). 772 780 Please specify (at least on the figure caption or figure notes) the Figures 10-43, Magnitude bins = 0.05 has been added to the notes on figures. magnitude bin size used for the incremental distribution (since the etc. curve does not appear to be normalized to unit magnitude increment),

COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision on this figure and other MFD plots (otherwise the incremental and cumulative plots cannot be reconciled). 773 Line This seems to be the first occurrence of the term "reduced source Lines 882-884 Explanation extended to clarify 798 MFD." Please define it (e.g., is it distinct from the Point MFDs in Figure 43?). 774 Line Figure 10-44 caption. "the rates for both subevents is the same" Figure 10-44 Caption corrected 803 replace is with are 775 Line Please clarify the meaning of "Hosgri source MFD." Line 891 Description updated to clarify that the shows the MFDs for the 805 collection of Hosgri rupture sources. 776 Line Might rephrase to indicate that these sources are characterized using Lines 893-894 Text modified as requested 807 the maximum magnitude PDF. Otherwise, it may be unclear what is meant by "simplified maximum magnitude sources." 777 Line Figure caption -please remove one "at the" in the phrase "at the at the Figure 10-45 Caption has been corrected 829 Hosgri subevent" 778 Line Figure 10-45 appears (based on the slope of left-hand extreme of the Figures 10-45 and The discussion in the text is focused on the general shape of 847 cumulative curve) to have been constructed with a magnitude bin size 10-46 the incremental curves as a means for understanding which of approximately 0.05 magnitude units, whereas uudging by the slope magnitude ranges are emphasized by which model, rather than breaks on the blue curve) Figure t0-46 appears to have been directly comparing rates from one model to another. constructed with a magnitude bin size of approximately 0.1 magnitude Notes have been added to the figures to clarify what units. If ii is the case that they were constructed with different bin magnitude bin sizes were used for each. sizes. please explain what normalizations were done to ensure that these curves are comparable. If the apparent difference in bin sizes is illusorv. please clarifv 779 Figure Correct the spelling of "strike" in the header for the top figure (a). Also, Figure 10-3 Corrections to the spelling are made. 10-3 why not use the same symbols for the models that are in common The only M-A relationships shown on both plots is HB14, and it between the two figure parts (a and b) is shown with the same symbol. The two WC94 relationships are different (strike-slip and reverse). 780 Figure Definitions of the dashed and solid lines in the Explanation are Figure 10-45 The figure has been corrected 10-45 reversed. 781 Line "or some other feature of the inversion solution (Page et al., 2014)." Lines 947 This phrase has been deleted in revised paragraph. 863 ? Please clarify some other feature 846 782 Line Please change is to are "the rates for both subevents is the same." Figures 10-47, 10-The figures have been corrected. 866 Please correct for all odd numbered figures that follow Figure 10-47 in 49, 10-51, 10-53, Figure this section. and 10-55 10-47. 783 Line Whether the ground motions will be higher or not is a GMC and hazard Lines 970-971 Text modified as suggested. 883 issue. It is suggested that the reader just be reminded that other line sources contribute to these scenarios besides just the Shoreline fault 860 oortion. 784 Line Replace is with are ? line number We could not find this typo. but we hope it was corrected by 973 given by PPRP the Tech Editor COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT PPRP COMMENTS AND Tl TEAM RESPONSES, CHAPTER 11 Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision CHAPTER 11 -Time Dependency Model 402 General Please review the chapter for notational consistency with Appendix. T1 for We will be standardizing on T1 he forecast interval seems to be the same thing as Tu in Appendix, for throughout 403 Line 8 rrhe first line is fuzzy in its meaning, Please improve the wording to mean Changed as suggested what you are trying to say: "Recurrence models can be divided into Line 13 categories, those that are time independent and those that are time '1ependent." 404 Line 10 What has been described is not a Poisson distribution (which would Changed as suggested. '1escribe the probability of n events occurring in a given time interval), but rather a Poisson process. Please use the more precise statement. Lines 13-15 405 Line 12 Please consider adding a definition of the hazard function, or referring to In these introductory section of the chapter we seek a Eq. 7 of the appendix for the definition. n/a more qualitative description. and reworded the sentence. rrhe hazard function is presented later in Chapter 11 406 Line 13 rrhis section discusses how time dependent models are considered but not rrhis is described in lines 28-30. We will promote the why. As noted. time independent models are typically used for site-specific paragraph to earlier in the introduction. PSHA purposes. Why is a time-dependent model being considered? Lines 10-12 Please provide additional discussion of the need for the consideration of a ime dependent model for faults and why the use of an equivalent Poisson rate is used, rather than a time-dependent PSHA. 407 Line 14 rrhis would be clearer if "models" was inserted after "most common" Line 21 Done 408 Lines 20-21 rrhe statement "time-dependent recurrence distributions are more Reworded to address the concern raised in the comment. K:;omplicated than the Poisson," implies that "Poisson" means "Poisson '1istribution," which does not make sense. If the intention is to compare the Lines 23-28 ime-dependent recurrence distributions with the exponential recurrence '1istribution (which characterizes the Poisson process). please make that K::lear. 409 Line 24 Might add something like, "particularly if there are other compelling reasons We've modified the description to improve the positive considering it." If there was no physical basis for a time-dependent basis to consider time dependence. The point here is that model and no data upon which to base it, there would be no justification for Lines 2-12 non-Poisson recurrence models should be considered if its use. hey cannot be ruled out, regardless of whether or not here is a physical basis for it. 410 Line 25 rrhe phrase "time-dependent fault recurrence" is incorrect. The occurrence reworded in addressing comments 406, 408 and Pt earthquakes can be time-dependent but faults don't recur over time Lines 2-12 1409 removing "fault" or changing fault to "earthquake" 411 Line 26 'The SSC recognizes ... " The SSC is now sentient? Do you mean the "Tl Reworded with changes responding to c.406-410. rream recognizes ... "? Please clarify what you mean here. Lines 2-12 412 Line 29 r.'ou included time dependent recurrence or recurrence models? Lines 2-12 Corrected with responses to comments 406-411. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 413 Line 35 Might be useful to say that this is done via seismic moment rate to account We added mention of the fault geometry directly, as *or rupture geometries. Lines 36-45 rupture geometries and moment rate are specific derivatives of it. 414 Lines 38-39 rrhe way it is described, the EPR appears to be a dimensionless ratio ("a Changed Rate to ratio. The EPR is a rate correction, and Factor that can be applied to the earthquake rate"). If this is a correct rightly understood as a ratio. understanding, please reconsider whether "Equivalent Poisson Rate" is an term, since the description in the text implies that it is not a rate Lines 43-45 at all, but a ratio of rates to be applied as a correction factor. If this is not a l'.;orrect understanding, please make the actual definition of EPR clearer. 415 Line 42 Unlike other chapters, this chapter is written in the first person. Suggest We wrote ourselves out of Chapter 11. using third person throughout the report. Line 48 416 Lines 42-43 'we review these data, and ranges of possible values where specific data rewritten are not available." Whal does this mean -it is unclear what these data" Lines 47-53 refer to when specific data are not available. Please clarify what you are In 417 Lines 48-49 Here it is stated that there are no data whereas earlier in the paragraph it is reworded from "no data" to "uncertain ranges". "limited data". Please clarify the intended meaning. Line 56 418 Line 55 Is there a hyphen missing in "site-to-source"? Line 63 !Yes. Revised , fixed. 419 Line 57 'available data available" -extra word here? Line 65 removed one. 420 Line 58 'slips per event" -do you mean "slip per event data"? Please clarify. Also Revised the previous sentence. and removed the note that displacement per event" is used in other places in this chapter Lines 65-66 in which the questioned phrase occurred. in Appendix EPR. If the meaning is the same, please consider changes o maintain consistency of terminology. 421 Line 62-63 'A trench at the lngley site shows activity in the late Pleistocene" but then rewritten to clarify. here is discussion of deformation (warping) in the past 2500 years and Line 69-76 1840 year-old deposits are faulted. These statements are incongruent. Please clarify. 422 Line 73-76 is a summary of the interpretations and there needs to be better page references to Lettis and Hall, 1994, have been referencing of the primary sources and/or sections of the report where the Line 70, 79 added. interpretations were developed. 423 Line 75 Please check whether "displacements" should be "displacements per 'displacements" says what we mean -several were and make any necessary correction. Line 83 measured, in the range stated. 424 Line 79 last sentence could be improved for clarity of intended meaning Line 87-89 Rewritten and developed to better give the interpretation. 425 Line 83-84 'recurrence intervals between 265 and 2000 years," sounds like there are to singular to fix the multiple sites reading. The multiple sites with abundant paleoseismic data. Do you really mean the Line 91 RI range is quoted from the paper. A page reference to on the recurrence interval falls in the range of 265-2000 yrs? he estimates has been added. 426 Line 89 'sample only the most recent few events" -do you really have the past few Modified to 'a few recent events'. (i.e., more than 2) earthquakes dated on the San Simeon fault and Los bsos faults? Please verify this statement. Line 99 COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 427 Line 89 Not clear what "both" refers to here, since there were multiple trenching Reworded to clarify the "both" and "sites" references along the Los Osos fault. Likewise, what are the "sites" are that are referred to below in line 91. Lines 98, 99 428 Lines 97-100 Is there a reason for specifying data types that currently don't exist? It It is not clear how this weakens the technical conclusions weakens the technical basis for the conclusions drawn. The conclusions were drawn in the absence of the Lines 107-111 ypes of data described here. The description helps to illustrate the types of data and the depth of investigation hat led to this anlaysis. 429 Line 99 'none of this sort" -are you referring to "this sort of data"? Please clarify Line 110 Reworded to say that for now these data are not 430 Line 108-112 rrhese statements about the effects of early historical earthquakes are fine We reworded including a closing statement of what how but they need context. Your basic argument is that there are early he mission record is understood as a temporal constraint of significant magnitude that damaged some of the Spanish Pn the improbability of a large event on the Primary faults. missions at significant distances. You need a concluding statement that this so that when you segue into the absence of such damage at the San Luis Obispo mission. it strikes home the argument that there have been no moderately large to large earthquakes affecting the region Lines 130-133 1772. Also, note that the location of the 2nd large 1812 earthquake (Dec. 22nd) is debated -Toppozada et al. (1981) place this on the SAF but his is a hotly debated topic among those working on the earthquake and its affects (i.e. tsunami, which has been found in Carpinteria, no direct and evidence found yet in paleoseismic exposures at Frazier Mountain, although they pushed hard to make a case, at first) 431 Line 120 Suggest adding "occurred" after larger. Line 132 432 Line 126 By saying that "it is likely that the local completeness level is actually potentially confusing. Reworded. lower", it sounds like less complete but you likely mean more complete. Line 139 Please clarify. 433 Lines 127-What is the reason for the different weights? Lines 143-145 is added to say that the weights reflect relative 129 h"I Team confidence in the two comoleteness dates. 434 Line 138 Please correct "cumulative density function" to read "cumulative distribution rt'es, done. *unction." Line 154 435 Lines 139-It is not clear that 0 is singular or plural, or what 0 actually signifies. This rrhe references to theta drew from more formal 141 needs more explanation. and a good definition of 0. nla references, and are unnecessary here. Theta has been 436 Line 177 rrhe correct statement is that the variate assumes only non-negative reworded rvalues, i.e., its support is the non-negative real line (the current wording Lines 182-187 implies only that the distribution itself is non-negative, which is true but not informative). 437 Line 185 Remove "is" Line 190 pkay 438 Line 186 Do you mean to say it doesn't depend onµ as a mean parameter, or that it 'mean parameter is correct. "mean parameter" is a depend on the mean of Line 191 for COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 439 Line 192 In reference to the phrase "less than what Poisson rate," please specify that Reworded from Poisson rate to specify the exponential he comparison is with the Poisson process that has the same long-term Line 195 k:listribution of the same long-term rate. mean recurrence rate that the given lognormal model has, if that is the intended meanina. 440 Line 193 Not sure what is meant by "anticipates". Please explain or choose a better is closer to the intended meaning than the word. Line 197 we put in by request. 441 Line 194-195 'we do not know the times of the most recent events for any ... " Earlier, you Reworded. The original state of knowledge was laid out the paleoseismic data and discussed recency of faulting on the Los imprecise. bsos fault (1840 rcYBP, line 72), and you discuss recurrence intervals on he San Simeon fault (lines 84-85), which imply some information on past Lines 197-200 l:!arthquake timing. Perhaps this lack of data needs to be better explained and better summarized as it leaves the reader confused as to what we know and what we don't know. 442 Line 196 If tMRE is treated as a random variable please state that explicitly. Reworded here to describe tMRE as known only as a Line 199 range. A line is added also to point ahead to how tMRE is incorporated. 443 Line 197 'The choice of functional form in time dependence is also unknown." As We removed "choice of'. you are saying the "choice" is unknown. Please restate. Line 201 444 Line 211 'Coincides with the data estimate" is vague as to whether the aperiodicity is Matthews et al. (2002) make the distinction; this wording pr is not the CV. If ii is the CV, please say so explicitly, if it is not. please was to respect their distaste for *'coefficient of variation" in what it means that it "coincides with the data estimate" of the CV Lines 209-214 *avor of "aperiodicity". "data estimate of the CV" was also yet is not the CV and why this distinction needs to be made. computational distinction made by Matthews. The rewording should put the terms on more familiar ground. 445 Line 212 Remove *'wide" Line 212 rrext edited as requested. 446 Line 228 Please justify why the 3 lime-dependent distributions plus the exponential Explanation is added above the definition of the lognormal k:listribution are a reasonable representation of the center, body and range Lines 439-464 k:listribution, above former line 220. Pf recurrence models. 447 Line 259 Please provide the technical justification for the DPE distribution in Figure explanation al paragraph length has been added 11-3, or provide a specific reference(s) (chapter or appendix, and under section 11.3, Logic Tree. Placing the explanation number) to the part of the report where the justification is Lines 439-464 near original line 259 would not be preferred because k:liscussed. parts of the technical justification are developed in the EPR discussion. 448 Line 260 Please state briefly what is meant by "fault distribution point" and give a !Yes, Hosgri slip rate was intended. We reworded to reference to the sub-section of Chapter 8 where it is defined K::larify, and added a reference to the Hosgri rate CDF. (however, a search of chapter 8 returns no match for fault distribution point"). Alternatively, if the meaning is just the 8.5, 50, and 91.5 percentiles Line 260 the GDF for Hosgri slip rate, please say so explicitly. In any event, if here is to be a reference lo Chapter 8 it should be made specific as to (and perhaps figure number). 449 Line 271 It appears that the correct joint probability is that of L TM and tMRE, not Describing the weighting surface as joint in L TM and L TM and S(tll TM) (in fact, the latter is a distribution, isn't it, not a random Line 271 MRE is better. The distributions of tMRE are given by the tvariable?). And joint probability of (L TM,tMRE) would be consistent with S(tMREILTM). Figure 11-5. Please review and correct the text if necessary. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 450 Line 272 Please provide further explanation of Figure 11-5. Are these plots to be Further explanation has been added. The joint probability interpreted as joint probability density plots? If so. why does the area under in Figure 11-5 has been normalized to its peak he function obviously exceed 1? Is each such joint probability density so the contours can be read as relative weights or *unction (if that is the correct interpretation) specific to a particular slip-rate as regions from which more or less of the CPR Some (not all) of this is cleared up after study of the appendix Lines 271-288 weighting has been drawn. material, but the explanation in this chapter needs to be self-contained to be comprehensible without familiarity with the appendix. 451 Line 274 Same comment as for Figure 8 of appendix: The horizontal axis in Figure 5 In Ch. 11 the comment is understood to apply to Figure is labeled "Equivalent Poisson Rate (and EPR is indicated in the caption), 11-6. "Ratio is intended. Text has been added earlier in but the text seems to indicate that this axis represents the random variable he section to explain that the CPR is a mathematical CPR, not the estimated value EPR. and this interpretation is reinforced by and that the EPR is the CPR distribution after he fact that the plot is presumably showing the CDF of a random variable Lines 228-232 weighting across L TM. tMRE. (i.e .. CPR). Please review and modify as necessary to make the text and Figure 5 consistent, and to make clear any conceptual distinction between CPR and EPR. 452 Line 279 Please clarify the meaning of the phrase "relative to a Gaussian rrhis detail was unnecessary for explanation of the EPR approximation" in this context. The Miller and Rice method minimizes and removed. misfits to the low-order moments by applying the moment-preserving Lines 288-289 properties of Gaussian quadrature. In what sense can this be thought of as minimizing "relative to a Gaussian approximation"? 453 Line 286 Please provide discussion and/or references (to external documents or to was added plus an additional figure showing report section(s)) justifying that the proposed CV weighting adequately Lines 289-327 CV values for well-studied paleoseismic sites. represents the center, body and range of technically defensible interoretations. 454 Line 323 rrhe verb "is" refers back to differences, which is plural. Please change to kl one 'are" Line 361 455 Line 333 Please clarify the meaning of "less coherent as a source of hazard." Lines 366-371 Coherent in the sense that they would not rupture as one source as the SAF does. Reworded to a simoler line. 456 Line 336 Scharer et al. (2014) does not appear in the list of references. Line 602 Reference is at original line 569. Perhaps it was missed somehow? 457 Line 347 Please review the appropriateness of the term "marginal distribution" in this Found "marginal distribution" on original line #405. (and consider whether it makes sense to refer to a marginal *conditional distribution" was intended. and the text klistribution-as opposed to a conditional distribution-as being revised. 'conditioned on" a value of one of the variates). The text does not make that any variate has been marginalized, but rather seems to imply that Line 381 he initial joint PDF has been defined as delta(tMRE-To) x p( L TM). If the erm "marginal distribution" is actually the correct one, please explain why .. 458 Line 349 rrhe correct figure reference for displacement per event models appears to Revised. With an added figure the reference becomes be 11-9 (not 11-8). Please check this. Line 383 11-10 459 Line 349 Please indicate (in both the text and figure caption) which recurrence model Lognormal model. References added. (lognormal, BPT, Weibull) is used in the construction of the results in Figure Line 383 11-9. 460 Line 351 Shouldn't observation be plural? Line 386 Pkay. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 461 Line 360-363 rrhe explanation of the averaging is ambiguous and can only be worked out Reworded to clarify that SAF1 weighted mean results hrough reverse engineering from Table 11-3. Please rewrite to make it *rom each recurrence model have been averaged to 1'.:lear whether: (1) only SAF1 is used in the final averaging; (2) a separate l'.lbtain the final SAF EPR estimate. mean is taken for each of the three selected percentile points; and (3) those Lines 394-396 means are weighted by 0.25, 0.5 and 0.25, for the 8.5, 50, and 91.5 percentile cases, respectively, to form a final weighted mean EPR. 462 Line 362 Please give the rationale for the 0.25, 0.5, 0.25 weighting (referring to Miller Removed in the rewriting for Comment 461. Numerically '1nd Rice if that is appropriate). Lines 283-286 weight values were added earlier with the first reference In 463 Lines 368-Please explain how the conditions (other than degree of hazard sensitivity) we simplified the discussion to focus on hazard 371 klescribed here apply differently to the non-SAF regional faults than they do Except for the SAF. regional faults together o the Primary (Hosgri. Los Osos. Shoreline, and San Luis Bay) faults. If a small fraction of one percent of total hazard. here is no difference. justify why ii is technically acceptable to not use an EPR for the regional faults even though it was found to be technically Lines 397-404 required to do so for the Primary faults. If the sole justification is absence of hazard sensitivity, please review this passage and consider whether it be better focused on the one relevant issue. 464 Line 371 Please provide reference(s) to studies that demonstrate the absence of to Chapter 14 was added in dispositioning hazard sensitivity cited here. Lines 403-404 Comment 463. 465 Lines 384 Please clarify the sense in which the San Simeon event is less rrhis section was revised to better reflect our state of mechanically related to the Primary faults than the Landers rupture is to the Lines 417-420 knowledge about the relationship between the San Hector Mine faults. Simeon earthquake and faults around DCPP. 466 Lines 396-Please indicate whether the Tl Team judges that the EPR model captures rrhis section has been modified slightly and clarified to 399 epistemic uncertainty to accommodate the absence of a reliable '3xpress the Tl Team opinion that the EPR captures the model for how large events influence the likelihood of subsequent events. If Lines 432-434 uncertainty of time dependence. provide the justification for that judgment. If not, please explain where hat uncertainty is captured in the SSC model. 467 Line 403 is required between "Farther afield" and "EPRs" for clarity. Done Sentence deleted Lines 436-438 468 Line 408 Please explain precisely (either here or in the paragraph beginning on Line rrhe EPR values for the logic tree were not derived by a 1436) how the final values of EPR for the Hosgri and SLPB cases shown in precise formula. Rather. the values for the logic tree are rrable 11-4 were obtained from the various estimates in Tables 11-1 and intended to represent Table 11-1 without overstating the 11-2 (the corresponding calculation for SAF was explained in Section n/a precision available in the model for time dependence. 11.2.6). There is some explanation in the paragraph beginning on Line 436, but it is neither complete nor precise enough to enable the steps to be reproduced. 469 Line 427-429 rrhe intended meaning of this sentence is not clear. Please clarify. Reworded to better reflect how the EPR values were Lines491-498 selected. 470 Lines 430-rrhere should be some recognition of what this approach means in terms of We reworded the first two paragraphs under section 432 he alternatives that are included in the values that comprise the tables. For Lines 487-510 11.3.2 to better align with how values in tables 11-1, 11-2. what does this imply about relative defensibility of the recurrence 11-3 were summarized for the logic tree. model functional forms? COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 471 Line 432-435 Please explain in what respect the range accounts for the fact that the EPR original wording was an oblique approach to justifying may not fully characterize all contributory factors. The range in the tables is pur rounding the EPR values to a bit more than 1 !Wider than the range of the three branches. Isn't the range derived directly Lines 494-495 figure. The branch values in the logic tree are by discretizing the CDF obtained from the EPR analysis? intended as representative of the range, but are ""' lli<>ir --Tli<> ... 472 Line 438 Please clarify the meaning of "rounded across fault slip rate cases." Reworded. Lines 499-506 473 Line 455 Please clarify if this is seismic hazard. If so, the influence on hazard of any Rewritten to clarify, including some distinction that the given fault is a function not only of the effective (EPR-adjusted) slip rate, as EPR increases hazard relative to the fault to which it noted. but the distance of the fault from the site. So large changes in the Line 528 EPR for distant faults will result in small changes in the hazard. 474 Figure 11-3 bottom panel has the same title as the upper panel. even though it is a Fixed. k:listribution of times, not displacements. Please correct title. Figure 11-3 475 Figure 11-3 box title and in the figure headers indicate displacement per event, but Lower figure title and title block have been revised. in the text. you refer to these as average displacement. Please clarify if Figure 11-3 hese should be indicated as "average" displacements. both in the figure headers and box title. APPENDIX H-Method For Estimating Time Dependent Fault Hazard in the Absence of an Earthquake Recurrence Record 499 Line 45 "Poisson probability distribution of ground rupturing earthquakes" is Distribution of what? And, in fact, the Poisson distribution itself (probability of exactly n occurrences in a given time interval. as a function reworded bf n) is never used in the report. Please consider changing to a more Lines 47-48 precise statement (e.g., "the model of ground rupturing earthquakes as a Poisson process assumes that events occur randomly in time"). 500 Line 47 rrhis would be clearer if "to occur" is inserted between "more likely" and k:lone 'when the energy" Line 49 501 Lines 58-60 PSHA also initially did not consider the faults that gave rise to earthquakes; Rewritten to open the paragraph with this point. Historical seismic sources were source zones, each of which likely included reference for PSHA was distracting, and removed. faults. The point should be made early in this section that the whole Lines 59-60 ime-dependent recurrence concept is for fault-specific recurrence behavior. 502 Line 66 word "be" seems to be missing between "cannot" and "rigorously". Line 65 rt'es, fixed. 503 Lines 67-68 Consider indicating that an additional reason for the use of the Poisson Good, added. model is that regulatory design criteria are expressed as target annual *requencies of exceedance (e.g., 10-4) without consideration of any time Lines 66-69 ktependence. 504 Lines 70-71 But. as you discuss below. the use of an equivalent Poisson rate does NOT section has been rewritten and hopefully clearer. require a change in the hazard code. just inclusion of the concept in the SSC model. Please clarify. Lines 71-75 505 Line 97 *cumulative density function" is incorrect; please rewrite as "cumulative changed. k:listribution function." Line 99 COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 506 Line 162 phrase "before reaching the long-term mean" could be misinterpreted has been reworded. The asymptotic value depends o mean that the CP ratio is asymptotic to the long-term mean. which isn't Lines 148-150 pn the recurrence model width parameter. IJenerally the case. Please consider rephrasing to avoid ambiguity on this looint. 507 Lines 166-you saying that we have absolutely no idea what the value of these No, not the intent. Reworded. 167 parameters might be? Or that we have no direct data upon which to base Lines 151-153 hem. but they can be estimated with considerable uncertainty? 508 Line 180 phrase "although it coincides numerically with the data estimate of the Reworded along the lines suggested in the comment. more familiar coefficient of variation" seems unnecessarily cryptic. Since, in Lines 161-162 Matthews et al. (2002) prefer the term aperiodicity as a its role as a parameter in a PDF (Eqn 10), alpha is equal numerically to the more general description, and their paper defines BPT in CV, please clarify why it cannot simply be said to be the CV. use, so mention of aperiodicity is to respect ........... _ ............... L... .... --. * , 509 Lines 205-statement is not always true for faults having good paleoseismic data. sentence starts "Individual values for Dare not 206 Please qualify that this information is assumed to not be known for the Line 185 normally known,", and explains what we do when Dis not Faults in this exercise. known. 510 Line 210-211 'The distribution conveys a relative agnosticism among choices in Fixed in text. k!isplacement per event (OPE) from 1.5 meter to 3.5 .. Line 191 Figure EPR-3 shows DPE from 1.5 -3. 511 Line 213 Up to 5.0 m in the text of the report (line 258, page 14 of chapter 11 ). m was intended. Please check and rectify if different. Line 192 512 Lines 214-Please consider changing to the following (less fragmented) -Changed as recommended. 216 In California. for example, the largest measured average slips per event on he San Andreas fault are 4.45 and 4.3 m/event for the 1857 and 1906 Lines 194-196 respectively (Biasi et al., 2013). 513 Lines 218-22 reference to an upper bound of 5 m/event in the text appears to conflict Plots have been modified to end at ranges shown in the with values up to 5.5 m/event given by the solid curve in Figure 3 (there is a ext. The OPE is implemented as a list with non-zero break in slope at 5.5 min the plot, indicating a non-zero probability point at for the Hosgri from 0.5 to 5.5 in 0.5 m increments, hat value of sliplevent). Likewise. reference to an upper bound of 4 but the plot incorrectly implies weight above 5.5 m. The m/event in the text appears to conflict with values up to 4.5 mlevent for the Figure H-3 shape considerations affect plots of other OPE k1ashed curve in the plot. Please check and make any changes required for K:urves. K;onsistency. 514 Line 227 If L TM is displacement per event divided by fault slip rate, then L TM must L TM does have units of mean recurrence time. Text in be an inverse rupture rate (or mean recurrence time), not a rupture rate as Line 206 he affected area has been modified accordingly. Please check the text for consistency and correct as necessary. 515 Line 247 Please replace "to" with "do" Line 225 k!one 516 Line 265 If the reference to Philibosian et al. is the same article listed in the Revised to 2011. references section. then it should be cited as 2011 (rather than 2012). Please check and make a correction if necessary. Line 243 COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 517 Line 268 Since the EPR is a dimensionless ratio, not a rate, it would be clearer and rrhe EPR is a ratio, as noted by the reviewer. The text less subject to confusion to call it something else. Later the EPR is (and several figures) have been modified accordingly. from the distribution of **conditional probability ratio (CPR)", nla erminology that explicitly indicates the dimensionless character, so calling EPR a rate and CPR a ratio is a source of confusion. Please consider this point. 518 Line 275 Please replace "complimentary" with "complementary." fixed. Line 266 519 Line 283 is needed arter "renewal" to set off the first part of this sentence. Done 520 Line 284 rrhe "tl TM" appears to be a typo-please check whether this should be Fixed as suggested, and the word "small" removed 'LTM". because it conflicted with the direction of the sentence. 521 Line 286 It will cause confusion to say that the CPR is elevated relative to the Wording has been changed to distinguish between the Poisson rate. because the former is a dimensionless ratio and the later is ratio and the corresponding rate. lln absolute rate (events/unit time). Please rephrase this to be more precise. 522 Line 286 rrhe distinction between CPR and EPR is never stated explicitly, and this rrhe first paragraph under Estimating Equivalent Poisson confusion later on. The eventual impression is that CPR is treated Ratios" is largely new and dedicated to clarifying the lls a random variable and EPR its estimated value: if so. please consider relationship between CPR and EPR. The second making this explicit, and if not, please add text to clarify the paragraph covering Figure 5 has also been rewritten. mathematical/conceptual distinction between them. 523 Line 288 rrhe phrase "declines to approach the Poisson rate at the upper probable rrhis section has been reworded and the explanation range of tMRE" may be misleading. First of all, since EPR is a ratio, it approach unity if the CP approaches the Poisson probability? If please rephrase to make that clear. Secondly, the phrasing can be interpreted to imply that the approach to the Poisson rate is an asymptotic behavior. As that is in general not the case, please rewrite to avoid that impression. 524 Line 297 rrhe peak appears to occur below the diagonal in Figure 6, not above the Rewritten. ktiagonal as stated. Please add clarification or correct the statement or "igure as necessary. 525 Line 303 rrhe term joint probability surface" appears to be used here to denote a rrhe explanation of the joint probability surface used for 'oint probability density. However, this is not made explicit. and doubt is tvveighting has been extended and clarified. The fact that raised by Figure 7, in which it is obvious that the integral under the surface Figure 7 was normalized by its maximum value has been is much greater than 1, ruling out its interpretation as a joint PDF. Further in the text. arises from Equation 13, as discussed in a subsequent comment. Please be explicit and precise about what is meant by "joint probability 526 Line 303 rrhe joint probability appears to depend upon slip rate. If that is a correct Remarks on the relationship of slip rate to individual EPR interpretation. please indicate (in the text and caption) what slip rate was were added in a new paragraph inserted to used to generate the probability function in Figure 7, and confirm that that introduce the "Estimating Equivalent Poisson Ratios" rate plus the Hosgri OPE model of Figure 3 was the basis for the marginal distribution p(L TM) used to generate that figure (or if, that is incorrect. give the correct explanation). If the joint probability does not ktepend upon slip rate. please improve the description to make clear why not. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 527 Line 308 survivor function S(tMREIL TM) integrated over tMRE (for fixed L TM) is survivor function actually does have unit area, by not generally unity. p(L TM), being a PDF, does integrate to unity. So W k:;onstruction. This was obliquely the point of the sentence integrated over the tMRE,L TM plane is not generally unity. Therefore Wis in former lines 313-315. The discussion of weighting, not a joint probability density, yet the text gives the impression that it is '1rea of the S, and the mathematics have been rewritten. intended to be just that (though that interpretation is also cast in doubt by Figure 7, as noted in a previous comment). If W is something other than a oint PDF, please explain clearly what it is. If W is a joint PDF, but the reasoning in this comment to the contrary is incorrect. please clarify in the ext why there is no contradiction. Otherwise make necessary corrections that W can be properly considered to be a joint PDF. 528 Lines 313-15 sentence seems correct, but it is confusing because its intended Rewritten to move the point earlier in the paragraph. purpose is unclear. Is it simply intended to point out that the variates tMRE lln d LT M are not independent (because the factor S in Eqn 13 depends not ust on tMRE, but also on L TM). so that (by definition) the joint PDF is not the product of the marginal PDFs? Please rewrite or amplify to K::larify the intended meaning. 529 Line 320-321 horizonal axis in Figure 8 is labeled "Equivalent Poisson Rate" (and use of "Rate" has been revised to "Ratio". EPR is indicated in the caption), but the text seems to indicate that this axis represents the random variable CPR, not the estimated value EPR, and his interpretation is reinforced by the fact that the plot is presumably the GDF of a random variable (i.e., CPR). Please review and modify as necessary to make the text and Figure 8 consistent, and to make K::lear the conceptual distinction between CPR and EPR. The same K:;omment applies to Figure 9. 530 Line 320-321 apparently the curve in Figure 8 is a CDF (or the complement of Figure is slightly modified to clarify the location of the its maximum value should be 1. This is not clear in Figure 8. If in fact K:;urve as it approaches 1.0, and notes are added in figure he curve does rise rapidly to intersect 1 at zero CPR (and from looking at EXPLANATION box. Figure 9 it becomes clear that ii does), to avoid any confusion, please indicate that fact with a modification to the figure or a note in the caption 531 Line 335-336 Please explain the meaning of the vertical dashed lines in Figure 9. Description added. 532 Line 343 Please review the use of the term "marginal distribution" here. Wouldn't rrhe intended meaning is as the reviewer indicates, a delta marginalizing on IMRE mean integrating over it, whereas what is proposed on tMRE=t_eqk. Because the weighting is done is concentrating the tMRE dependence in a delta function delta(tMRE-pn narrow discrete values for tMRE, a single column _eqk) to begin with, so W=p(L TM) x delta(tMRE-t_eqk)? In what sense is it remains across the range of L TM. The reduction shares rue that "the equality constraint is a form of marginal distribution"? in common the idea of reducing a range on LTM-tMRE to on L TM alone, but it is not done by integrating, thus is not a true marginal distribution. The relevant L ... ,.. .. ....i;,,....,., a....,..,.. h,..,..,,... .. ,.. .. ,;,..,.....,i 533 Line 396 II is a little recursive to say that values of parameters used for Figure 12 was introduced by the author because of an were fixed to the values used in Figures 9-12. Please consider revising this incomplete editing of the draft. Back reference to Figures S-12 is removed and the sentence has been reworded COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 534 Line 407 Figure 13 has not been cited prior to this citation of Figure 14. Please check former Figure 14 (Weibull) has been moved to Figure whether the figure currently labeled 13 should be deleted and figures 13. A new Figure 14 is added that more directly l'.;urrently labeled 14 and 15 should be relabeled 13 and 14. If so, then the l'.;ompares the three time-dependent models. This at this point in the text should be Figure 13 (and subsequent figure is promised in Chapter 11 text. l'.:itations are already correct). 535 Line 426 would be useful between "principle" and "slip rate". Done 536 Line 456-457 Please explain the connection between the weighting method implemented rrhe maximum likelihood approach underlies our EPR here and a maximum likelihood perspective. because weighted solutions are extracted using joint L TM-tMRE probabilities. However, we reworded to replace the ML mention with a more important observation, that the action of the survivor to cut off right probability space leads to stability Pf the EPR estimate across recurrence model functional 537 Line 466-467 Please provide references for the cited MFD functional forms. Need truncated GR and WAACY refs. 538 Figure 5 Please correct the following deficiencies in the figure: 1. The caption is inadequate It should provide additional information. See comments on Figure set. including at least the CV used to generate the plots. the meaning of the circles in the upper right panel, and the meaning of the curve cutoffs K;B: redraw. in the lower panels. It should also properly indicate the nature of the are not all lognormal distributions, as the caption would even though they are all quantities derived from lognormal k:listributions. panels are called out by letter (e.g., "Figure 5d") in the text. but they llre not labeled with those letters. 539 Figure 7 Please indicate in the caption what slip rate was used to generate this See comments in Figure set. what OPE model was used ( Hosgri OPE model of Figure 3?), llnd what CV was assumed. 540 Figure 8 Please indicate in the caption the meaning of the red stars. See comments in Figure set 541 Figure 9 Please define the symbols, either in the legend or the caption or both, as See comments on Figure set wen as stating the meaning of the vertical dashed lines (which do not seem o be mentioned in the text either). Please also improve the figure title. tvvhich is rather cryptic (what does "Four Tmin,LN". mean. for example?). please review the use of EPR for the title and horizontal axis, and make changes as necessary to ensure consistency with the discussion in he text and with any intended distinction between EPR and CPR. 542 Figure 10 Please write a more complete caption for this figure. Is it based on the See comments on Figure set Hosgri OPE model? What are the dotted lines in the upper panel? Tmin is in the legend, but not clearly identified there, so it also should probably be given in the caption. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 543 Figure 12 Please improve the caption. At the least, the meaning of the colors should bkay. notes in file EPR_appendix be explained. Figures_with_notes.pdf. GB followup: redraw Weibull; olors backward. 544 Figure 13 rrhis figure may be redundant. Please check whether that is the case and Current Figure 13 to become Figure 14. It shows the BPT klelete if appropriate. results. The current Figure 14 shows Weibull. 545 Figure 14 Please check whether th is figure shou Id be relabeled "Figure 13". r-.'es, move this figure to become Figure 13. 546 Figure 15 Please check whether this figure should be relabeled "Figure 14" and write Figure 15 is correct after BPT figure is written in. informative caption (which should include deciphering "BWM"). For the caption, maybe the proposed text in the figure markup will do. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT PPRP COMMENTS AND Tl TEAM RESPONSES, CHAPTER 11, part b Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision Chapter 11-Time Dependency Model-Comments originally placed within Chapter 6 267 Lines Please consider rephrasing to the following -Key data from the DCPP Lines 49-50 Text modified as suggested 43-44 region are needed for fault slip rates and the lime since the most recent earthquake 269 Lines Please cross reference where hazard sensitivity studies show that the Line 62 Text added as suggested 53-55 SAF has only a small effect on hazard. 270 Line 62 Please provide a more specific reference (section number and figure Line 68 No change. Reference is to Lettis and Hall (1994) number(s)). 272 Line 63 Please show/reference lngley site on a figure. Line 69 Page reference in Lettis and Hall (1994) added 274 Lines It is recognized that the conclusions presented in these paragraphs Lines 66-96 Specific pages in primary references added 57-88 regarding recency, displacement per event, and recurrence intervals are summaries of the conclusions drawn elsewhere. However, the reader would benefit from specific references to the locations in the report andfor the primary references where the data have been evaluated and the conclusions and uncertainties have been developed 278 Lines Please flesh out this line of reasoning out-Lines 114-116 Text added per suggestion. 104-105 The founding of the mission at SLO in 1772 together with the lack of reported earthquakes in mission documents provides a rationale for settina Tmin=242 vr. 279 Line "Missions were sensitive to strong ground motions" Lines 118-125 Text editing and reviewed to make sure sentences 107 Please expand. following this one adequately support the statement. 280 Line Please consider rephrasing -Lines 130-132 Text modified per suggestion. 118-120 In summary, the lack of any damage reports in documents from the San Luis Obispo mission make it unlikely an earthquake of M6.5 or larger on DCPP Primary and Connected faults since 1772. 286 Line Please remove "is" Line 189 Typo corrected 185 288 Line Please remove wide" Line 211 Typo corrected 212 291 Line Please change displacement to displacements. Line 245 Text edited per suggestion 248 301 Line Figure 11-8 should be Figure 11-9. Line 382 Figure reference checked and updated to t 1-tO 350 COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 309 Line Consider replacing accidently with coincidentally. Line 412 Text modified as suggested 379 321 Line Please replace to with " do" Line 523 No change; text reviewed and to estimate" is correct. 453 COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT PPRP COMMENTS ANO Tl TEAM RESPONSES, CHAPTER 12 Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision CHAPTER 12-Regional Fault Sources 476 Lines 6-8 'Faults capable of producing moderate to large earthquakes that are not Lines 16-18 rrext revised as suggested. included as Regional fault sources are represented by the areal source (Chapter 13)." Please move to end of paragraph after line 13. 477 Line 13 In place of (or in addition to) the word small," please provide a quantitative Ines 11-13 rrext revised to cross reference to preliminary sensitivity of the relative hazard contribution from the regional faults. (Workshop 1.Appendix D) and Chapter 14 results. 478 Lines 28-29 Sounds like a sales pitch rather than an accurate technical statement. If the Lines 31-34 Reworded to be more measured. is "comprehensive" why does it omit many faults? What is meant by 'objective?" How can something be consistent with "all available data" when misfits are allowed to occur? Suggest toning down the description of UCERF3 to be more realistic and to specify that it provides a reasonable basis for characterizing some of the regional faults for the SSC model. 479 Line 34 Please consider citing an authoritative source such as a USGS report in Line 40 Petersen et al. 2014 (see their page 2) of the statement on this line. 480 Line 35 rrext moves back and forth between first person and third person. Suggest Lines 39, 51, 96, rr ext revised to use third person using third person throughout. 115, 119, 159. 181 481 Line 35 and (which implies changing them) or adopting (which does not imply Lines 39, 41 Changed; "adopting" was intended. Idea was preserved 37 hrough a rewrite to accommodate Comment 480. 482 Line 39 rrhe quotation marks suggest that this is a quotation from some source, or Lines 43-45 Puotes removed; the ordinary meaning of the word is hat the word itself, rather than its ordinary meaning, is the object of intended. interest. Please consider whether either of these is the case and edit (or not) accordingly. 483 Line 58 Please specify that this is an assessment made by the Tl Team. Line 62 rrext revised as suggested. 484 Lines 59-60 rrhe first clause of this sentence appears to have some sort of transcription Lines 62-66 Reworded and simplified. Please review and correct it. 485 Line 68 Where does this logic tree exist and who assigned the equal weights? Lines 70-71 Clarifications added. 486 Line 72 'Figure 12-5 shows ruptures common to both" Is the top panel of Figure Lines 74-75 Reworded The figure label is correct. the text has been 12-5 intended to include faults common to both UCERF3.1 and 3.2 The figure is copied from the UCERF3 main report, models? Presently, it is labeled Fault Model 3. 1. not accurately represented in the text. 487 Line 85 'the depiction in this SSC model, while FM3. 1 does not. Line 88 rt'es, done. Please consider deleting "depiction in this" 488 Line 95 Suggest deleting "radial." Line 98 Reworded. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 489 Line113 'come nearer closer to the DCPP than the physical SAF itself." Lines 114-116 Rewording allowed a shorter, clearer construction. Please consider rephrasing to -come closer to the DCPP than the SAF. 490 Line 117 Please replace we" with Tl team, if appropriate. Line 119 rr1 team 491 Line 216 Figure 12-4 indicates Queenie fault". Is there a difference? Figure 12-4 Figure revised to change labels to read Queenie, Purisima, and Lompoc structures to be consistent with ext. 492 Line 244 you suggesting juxtaposition of units of similar age that have Lines 260-261 rrhe text has been revised to be more consistent with different thicknesses? Please clarify. Otherwise, this could be in McCulloch et al. (1980). The concept of interpreted as growth strata. uxtaposition of units of similar age having significantly klifferent thicknesses is likely what the authors intended they cite this as evidence of significant lateral (rather than indicative of predominantly vertical bffset as evidenced by growth strata). However, in that the citation does not specifically state this, we are reluctant to explicitly make this assumption but would that this is implied 493 Lines 252-'Sorlien et al. (1999) note that the large amount of strike-slip inferred is No change No. Sorlien et al (1999) do not provide an estimate of slip. 253 based on a regional tectonic model, and they discount the large offset." rrheir interpretations of the data argue for predominantly klip slip (initially normal: later contractional) movement Do Sorlien et al. ( 1999) provide an estimate of slip? rather than major strike-slip. 494 Line 262 Please consider changing "overlapped" by onlapped or draped Line 280 rrext revised to use the term "onlapped". 495 Line 290 What is the type of magnitude indicating 7.0? Ms? Line 308 rrhe text has been modified to clarify that it is surface wave magnitude (Ms) 7.0. 496 Lines 301-It is understood that the characterization is simplified (i.e., single-valued). Lines 331-355 rr ext has been revised to provide additional justification 302 However, there is insufficient information in this section to understand how description of the simplified source characterization he values in Table 12-5 are derived. For example, the estimated slip rate used for the Non-UCERF3 regional fault sources. wor the Queenie structure is said to be 0.005 mm/yr in section 12.6.1.2, but Kl.1 mmlyr is shown in the table. The slip rates for the Santa Lucia Bank West Basin -Southwest Channel faults are listed here at 1 mm/yr. Earlier, you cite a rate of 0.2 mm/yr since the Pliocene forthe WB_SC fault, Which is likely a maximum as you state that much occurred toward the end the early Pliocene. Slip rates for other faults shown in the table are not kliscussed al all in the text. What approach was used? In the absence of wault-specific information. drawing analogies to other faults is appropriate. but must be indicated as such in the text. Likewise. what was the approach used to assess Mchar? It is not sufficient to merely indicate that sensitivity show these faults aren't important; that conclusion is dependent pn the characteristics that are ascribed to the faults. If one of the faults had rate of 30 mmlyr, the hazard significance might be different. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 497 Figure 12-3 Consider a way to name the fault sources -not everyone will be familiar No change Faults within approximately 60 km of the site are labeled with the California fault system. pn Figure 12-6. More distant sources are not significant to he hazard at the DCPP. 498 Figure 12-7 What produces the sloping linear trends in seismicity rate between M6.5 No change to We put most of the explanation of the diagonal trend in M7.5. These are interesting and should be explained in a caption figure. Text he text, with a note of referral in the figure itself. The (which needs to be added to this and other figures). added 134-146 rends and the difference in rates between trends are k!iscussed in the text with the figure. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT PPRP COMMENTS AND Tl TEAM RESPONSES, CHAPTER 13 Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision CHAPTER 13-Areal Source Zones 798 Line 1 Please consider adding some additional introductory information. such as Lines 3-6 Additional text provided as requested. the topics that will be covered in this chapter. 799 Line 2 Delete "of." Line 2 Modified to "away from" 800 Line 12 "but the faults are not sufficiently active to be considered" Consider Line 17 Added the phrase "well constrained" to the sentence. adding *'or well-constrained or studied" as there may be other faults of similar activity to the Shoreline fault that have simply not been identified or studied. 801 Line 17 It would be useful to acknowledge that, although it is recognized that Lines 22-30 Clarification is added on how distance adjustments are moderate-to-large earthquakes rupture finite lengths of faults. at large added to implement the point source characterization, as distances those ruptures can be approximated by ruptures effectively at a recommended. point for purposes of seismic hazard analysis. 802 Line 35 Add "smoothing" after Gaussian. Lines 67-68 The text is modified as recommended. 803 Lines Please give the units for the quantity 1 O" (e.g., is this an annualized rate Lines 72-73 Text has been modified to clarify the a-value is the log of 39-40 for M>O events?). the annualized rate of MO+ earthquakes. 804 Line 42 A factor of 0.1 would appear to be the correction factor for accounting for Lines 77-78 Text modified to more accurately describe the 0.184 the 0.1 magnitude increment, not the factor 0.184 cited on this line. The factor. latter would appear to account for the 0.1 factor multiplied by the additional factor 1.84, which equals bx log.(10), and accounts for the relationship between the exponential density function and the Gutenberg-Richter cumulative distribution. Please check whether this explanation is correct and make anv reauired chanaes in the text. Lines This leaves the reader wondering what the implications are for the n/a Discussion of 2014 model is removed as it is not used. 43-46 research coming out afterthe model was locked down. Please explain how this is relevant -did you use it or not? If so, then consider deleting this sentence, as it is irrelevant. If not, then close with a statement of what was and was not used. As it is, there is no final context to understand the meanina of this sentence. 806 Line 52 Replace "we make" with "the Tl Team makes." n/a Sentence was removed 807 Line 57-This sentence as written seems to say that the given latitude/longitude Lines 182-183 The sentence has been rearranged to clarify that the 59 range is that part of the Regional ASZ that extends beyond the 320 km Regional areal source zone extends beyond the 320 km limits, whereas Figure 13-1 makes it clear that the given latitude/longitude limit. Please note that the sentence has been moved range actually defines the full Regional ASZ (and this full range happens down into the section on the regional source zone to extend beyond the 320 km limits). Please rewrite to clarify the meanina. 808 Line 64 The concept of a "DCPP Site Vicinity" seems to be important enough to Lines 11-13 A definition of Site Vicinity has been added to Section be named and capitalized. yet has not been defined up to this point in t3. t Chapter 13. From Figure 13-t, it seems to be defined by a 40 km radius circle centered at DCPP. but this has not been made explicit. Please make sure this term has been defined prior to its use, and also be consistent with caoitalization re.a., note that the term is caoitalized in the COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision text. but not in the figure legend). 809 Lines II is not clear at this point why two catalogs are being considered, how the Sections The chapter has been reorganized to clarify the purpose 67-68 comparisons with the predicted rate will be done, or what "adjustments to 13.2.1. 13.2.2 of considering catalogs, and a reference has been the baseline gridded seismicity rates" means. Please provide more added to the section where adjustments are assessed. explanation and context. What type of "adjustments" would be made if there are differences? Or reference other parts of the report where these issue are discussed. 810 Line 74 It would help the reader to also indicate that those two catalogs are n/a A reference to the section in which the catalog seismicity discussed below. rates are compared to the gridded seismicity rates is added to the preceding paragraph. and this line is deleted. 811 Line 75 Considered for what? Remind the reader what the catalogs are being Sections The chapter has been reorganized to clarify the purpose considered for and how they will be used. 13.2.1. 13.2.2 of considering catalogs, and a reference has been added to the section where adjustments are assessed. 812 Line 88 This would read more clearly if "the" was placed before "Felzer" Lines 144-145 Term changed to. updated UCERF3 catalog" throughout text and figures. 813 Line 88 This is a methodology section, but it would help the reader if a pointer was Lines 98-99 Reference has been added to Section 13.4 directing the made to the section where the conclusions from exercising the reader to the section where adjustments are assessed methodoloav for the Vicinitv sources are aiven. and the conclusions are drawn. 814 Line Again. a pointer to where the Local sources are described would be Line 109 Reference has been added to Section 13.5. 106 useful. 815 Line Please be specific about what quantity is plotted in Figure 13-2 (e.g., is it Line 75; The values shown on this figure (which is now 13-6) and 117 the annual rate of events in a 0.1 magnitude-unit wide bin centered on Figures 13-6 Figure 13-7 are the gridded seismicity rates. These may MO, per 0.1 x 0.1 dearee soatial bin?J. and 13-7 be converted to a-values using Equation 13-2. 816 Lines Please provide further technical support for the 70%-30% distribution Lines 198-200 References to the hazard sensitivity analyses that show 124-125 (e.g., is it consistent with focal mechanism distributions where those data and 94-97 that the regional areal source does not contribute are available?), or reference sensitivity studies or other evidence that significantly to hazard have been added. indicate that the effect of this distribution is not hazard significant. 817 Line Please consider replacing second "and" in the sentence with *'as well as Line 218 Text modified as recommended 142 818 Line Agreed that it is a less clear association. but Edna and the western portion Lines 225-229 Although there may microseismicity associated with the 149 of the Los Osos show some spatial association with microseismicity -northwest-trending part of the offshore Los Osos fault, in please consider softening by using "less clear association" -rather than our evaluation of seismicity data within the Irish Hills we "no clear association" find no clear association of seismicity with the Edna or Los Osos fault. The text has been revised accordingly. A reference to the discussion of microseismicity in section 13.5.2 and 13.5.3 is added. 819 Line Please consider "higher density" as a replacement for (the slightly Line 233 Text revised as recommended. 154 awkward) "qualitative(ly) greater number" 820 Line This table needs a caption explaining each of the Table elements. Also. Table 13-2, Table is clarified. Scale factor is defined in the opening 189, the implied scale factor is not clearly explained. Lines 247-250 paragraph of section 13.4.2 Table 13-2 821 Line Consider replacing that" with "as to which" for clarity Lines 282-289 Paragraph modified; sentence omitted 207 COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision 822 Line Please state why this 3-point distribution is an adequate representation of Lines 290-300 Revised paragraph provides basis for 3-pt distribution 209-211 the CBR of the TDI. capturing uncertainty. 823 Line Consider changing to a greater extent" Lines 307-308 Text modified as requested. 218 824 Lines Consider breaking up this very long sentence, for clarity. Line 305-312 Text modified as requested 215-223 825 Line "study" should be plural. n/a The chapter has been reorganized and this sentence is 247 deleted 826 Line Please define what is meant by virtual faults, or indicate in the text that Lines 33-35 The concept of virtual faults is described in the revised 248 this term is used in a sense that will be explained later in the chapter. introductory section. 827 Line Please define what is meant by "semi-randomly." or indicate in the text n/a This term is no longer used to describe the spacing of 250 that this term is used in a sense that will be explained later in the chapter, virtual faults. if that is the case. 828 Line Need an introductory sentence that states what this section is about. Lines 332-337 In lieu of an introductory sentence here, we amended 254 the end of the introductory paragraph (Section 13. 5) to provide a *'road map" of the section. 829 Lines Consider using a, b c, etc ratherthan #, x, and y for the 2014 PG&E Line 596 and PG&E (2014) is the CCSIP report, which contains 12 257 and citations. Also. there are 8 PG&E 2014# citations listed in the references Numerous chapters. This chapter has been revised to refer to each numero section. Please rename them all so the reader knows which citation locations CCSIP report chapter independently. which is consistent us other refers to which reference. throughout the with the remainder of the Diablo Canyon SSC report. location text s 830 Line Replace "was" with "were." Line 619 Text modified as requested. 282 831 Line The word inference is pretty weak. How about, "it can reasonably be Line 622 Yes. Text modified to read .... .first-order conclusion 285 concluded"? that... " 832 Line Figure 13-6 should be 13-5. Line 642 Figure references updated to the current figure numbers. 304 833 Line To the extent possible, it would be preferable to replace references to Line 652 The Tl Team has made a point of referring to 315 workshop presentations by references to published reports or papers. For presentations made at the Diablo Canyon SSHAC example, please consider whether the pertinent part of McLaren's workshops to emphasize that we are following the powerpoint presentation could be covered by references to Mclaren & SSHAC process. The presentations are made available Savage (2001) and to the 2011 PG&E Shoreline Fault report. Please to the public, and a website address where the check on the viability of similar substitutions for the other workshop presentation can be found is included with the title of powerpoint presentations cited in this paragraph. each presentation in the reference section. 834 Lines Consider breaking this long sentence into a couple of parts to assist the Lines 665-671 Text modified as recommended. 327-332 reader. 835 Line This sentence would read more clearly if "is more problematic" was placed No change This rearrangement is not adopted. We consider 332 after "Local Source Zone" in line 331 splitting the sentence (as recommended in comment 834 l to be sufficient clarification. 836 Line Please state the basis for the Tl Team judgment that the method and Lines 681-698 Text modified to provide support of this judgment. 341 results are unreliable for identifying laterally continuous fault sources in this context. 837 Line The dips might be consistent; however, the OADC-FM fault plane Lines 684-689 Uncertainly in the directions of dip associated with the 346 solutions dip in the opposite direction lo the dips in the NE and SW OADC-FM solutions is addressed in the new. more vergent models as well as dips interpreted from seismic and well data in thorough discussion of these results. the CCCSIP. Please clarifv. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision 838 Line "Map" should be plural. Line 712 Text modified as recommended. 348 839 Line Please consider deleting "compiled from that effort Line 715 Text modified as recommended. 351 840 Line Insert "shown" (i.e., "is shown on"). Line 723 Sentence rearranged to address this issue. 359 841 Lines Might consider rephrasing -The Tl Team judged that the quality of the Lines 733-736 Text modified as recommended. 365-367 seismic reflection data used to delineate the faults was poor and introduced much uncertainty in mapping fault dip and architecture, a concern expressed bv the authors (PG&E, 2014#, Chapter 7). 842 Lines Also might want to mention that even though the interpretations are Line 739 A note is added that the cross section is consistent with 371-374 uncertain they are constrained/consistent with well data in the region. surface geologic and well data. 843 Line "within the" is repeated -please delete one. Line 749 Text modified as recommended. 384 844 Lines Please explain why the existence of a residual uncertainty as to the Lines 752-754 Text is modified to clearly present the rationale for the 389-392 amount of strike-slip deformation present would justify assigning strike slip aleatory variability in the model (and avoid mixing a higher frequency of occurrence relative to the reverse style (i.e., if I have epistemic uncertainty). a C average on half the class assignments, and don't turn in the other half. there is residual uncertainty about how many A's I would have qotten, but this mav not iustifv raising mv grade to a Bl. 845 Line Remove hyphen in half-way; also please check hyphens throughout text Line 762 Hyphens were checked throughout the report by the 396 (e.g .. line 389. well constrained needs a hyphen). technical editor. This one was removed as part of that process. 846 Line Note typo: "Where" should be lower case. n/a This sentence was removed as an alternative approach 421 to the assessment of rates for the Local areal source zone was used (Section 13.5.1) 847 Line As noted in a previous comment, the factor 0.184 appears to account for Lines 76-78 This factor is described in Section 13.2.1 421 both the magnitude increment and the transformation from the incremental to the cumulative magnitude-frequency relationship. Please check and make appropriate changes in the text. 848 Line Table 13-3 has NE and SW dips for both strike slip and reverse -the logic Figure 13-19 Figure is modified for consistency. Please note that the 452 tree in Figure 13-14 has N or NE and Sand SW for reverse faults -logic tree is now shown on Figure 13-19 please make consistent. 849 Line Please add at this point in the text that "slip rates for the virtual faults" in Lines 826-827 Text modified as recommended. 457 this context will mean the sum of slip rates across all the virtual faults. Currently this is a point of confusion until it is finally explained on Line 491-493 and in the footnote to Table 13-5. 850 Line Might want to add some supporting information as to why less than about Line 836 This sentence has been deleted. 466 4. 851 Line Please check whether Mo on the left side of Equation 13-5 should actually Line 840 A definition of M0.;has been added 472 be Mn.;. If so. please correct. and if not, please explain what Mo.1 means on the right side of Equation 13-6. 852 Lines The s" needs a dot above it to indicate that it is slip rate. Otherwise, this Line 851 Modified as recommended. 479 and equation will be mistaken for the equation for Mo. Use of "s" for slip is 480 standard notation, so using it without the dot for slip rate will be confusing 853 Line Please check and correct this rate. which should probably be "0.07 Line 890 Modified as recommended. 505 mm/yr." COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision 854 Figure Using colors in the explanation is a little problematic as they don't match Figure 13-1 The colors were selected to be readily distinguishable 13-1 the colors in the figure in a consistent way due to overlapping color with from each other. some transparency. For instance, the regional source zone has a different color onshore versus offshore. 855 Figure Please give the units for the rates shown in the legend (e.g .. indicate that Figure 13-6 Please note that the figure has been renumbered as 13-13-2 they are annual rates if that is the case), and be specific (in the text or a 6. The colors shown here are the seismicity rates. They caption or note on the figure) about what quantity is plotted. E.g., does it can be related to a-values using Equation 13-2, as represent the annual rate of events in a 0.1 magnitude-unit wide bin described in Lines 75-78. containing Magnitude 0, as estimated by 0.184 x 1 o* (where a is the annual rate of events of M>O) as Line 42 seems to indicate? We did not add faults to the figure to avoid distracting readers from the main point of the figure. Consider adding the major faults to this figure -would clearly show that the nearest red areas are associated with the San Andreas fault. 856 Figures In the Explanation", where is spelled "wehere" and buried is spelled Figures 13-2, These and other spelling errors were corrected. Please 13-3. -"burried". Please correct the spelling in all such figures. as the error is 13-3, and 13-4 note that the figures have been renumbered. 4, -5 reoeated. 857 Figure Observe 2 colors for the 0.1' grid; however only one color (yellow) shown Figure 13-7 The variations in yellow shown on the 0. 1 Vicinity areal 13-6 in legend source zone grid are due to overlaying the grid scale onto the project basemap, which includes grayscale colors onshore and blue offshore. We find ii useful to consistently use the same project base map for the report, and consider that readers will be able to recognize that the shades of yellow are all meant to represent the same rate (shown in the explanation). Please note the figure has been renumbered as 13-7. 858 Figure Notes state "Figure modified by Hardebeck, 2012; Legend states "From Figure 13-13 Conflicting references have been clarified. 13-8 Hardebeck, 2011" If the distinction is intentional and necessary. please Please note that this figure has been renumbered as 13-add some clarification. If both references are to the same content, please 13. make consistent. 859 Figure The figure has PE as a site. whereas the Abbreviations: lists it as PB for Figure 13-14 Figure has been corrected. 13-9 Point Estero. Please correct the abbreviations to PE so that they are Please note that this figure has been renumbered as 13-consistent. 14. 860 Figure Cites PG&E (2014). Is this 2014x, 2014y or 2014#??? Figure 13-16 The citation has been corrected to PG&E (2014, Chapter 13-11 7). Please note that this figure has been renumbered as 13-16 861 Figure No apparent dip symbols appear to be used in the figure. Either make Figure 13-17 There are numerous apparent dip symbols shown above 13-12 these larger/clearer or delete reference to them in the "Geologic Symbols" the ground surface on the figure. They are already fairly explanation. crowded, and making them larger would cause them to block one another. Please note that this figure has been renumbered as 13-17. 862 Figure Is it reasonable to have virtual faults that cross the Hosgri fault zone? Figure 13-18 The virtual faults are shown on the figure to illustrate 13-13 their geometry and spatial distribution relative to the DCPP. The parts that extend across the Hosgri fault zone do not affect hazard at the DCPP. Because there is not enough information to characterize these as fault sources, the Tl Team considered it appropriate to characterize all the virtual faults the same wav, instead COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision of attempting to distinguish differences in length and Mmax for different parts of the zone. Please note that this figure has been renumbered as 13-18. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT PPRP COMMENTS AND Tl TEAM RESPONSES, CHAPTER 14 Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision CHAPTER 14-Hazard Sensitivity 925 General comment: at several locations, only a discussion is given of what Additional text is provided, as appropriate, recognizing the sensitivity analyses show. More discussion is needed of 'tlbY these that the scope of this report is to document the SSC results occur, particularly as related to the particular elements of the SSC model and not to document or defend the final PSHA model. Otherwise. the reader is left to ponder and. given the various results. assumptions that were used to construct the sensitivity cases, may question whether the result is credible. 926 General comment: Figure captions (or "notes" for the PG&E template) are Figures have been improved for clarity. very much needed for this chapter. Without them, the reader is forced to Hip back and forth between the figure and the text in order to gain an understanding of the important messages being portrayed. The captions should draw the basic conclusions-or "take-aways"-for each figure. 927 Lines It is suggested that this sentence be the topic sentence for the chapter. Lines 1-3 Revision accepted 68-71 928 Line 81 Consider putting the sentence from Lines 109-111 at the end of this Lines 19-21 Revision accepted section. 929 Line 95 Please replace "was" with "were". Line 37 Revision accepted 930 Line 99 It is suggested that a description be given of what the tornado plots show Lines 41-43 Additional clarification provided (relative contributions to hazard uncertainty) and why they are called tornado plots (largest contributors to uncertainty are placed at the top of the diagram) 931 Lines The explanation of the construction of the tornado plots is given more Lines 52-55 The cases that are specifically commented on are for 101-103 precisely and clearly here than has been customary (thanks!). But a values not in the logic tree. In these cases. the corollary of the description (specifically, of the normalization) seems to be sensitivity analysis assumes the full 100% weight on the that the values on a given line of a tornado plot (weighted by their branch test case. The tornado ratio value provided to shows weights) should sum to unity. Visually, that appears to be at least roughly what the impact would be on the total hazard if the test true in most cases. Bui there are exceptions, e.g .. "IHEB Areal" in Figures case was used instead of the logic tree values. The text 14-7, 14-8. "synchronous GM" in Figure 14-9. 14-10, "full characteristic" in is clarified to state that both types of sensitivity analyses Figures 14-11. 14-12. "magnitude PDF in Figure 14-12. If this is a are presented on the tornado plots. (See further misunderstanding, please clarify (e.g., perhaps it is mistaken to identify explanation in next comment). each line of a tornado plot with a node of the logic tree?). If this is correct, please refine the explanation of the tornado plots to accommodate the aooarent exceotions to the current definition. 932 Lines What are the "some cases" and please explain why they provide a value Lines 52-55 See previous comment response. Cases not shown in 107-108 that is not in the logic tree. the logic tree, for example, include the use of gridded seismicity for the local areal source zone rat her than virtual faults (which IS in the logic tree), and using only the YC characteristic model for maximum sources. This type of analysis is performed for a variety of reasons, such as to support simplification of the SSC model. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT 933 Lines Does this mean that the conclusion drawn from the sensitivity analyses Lines 19-23 Additional clarification provided. 110-111 are also "not representative"? Perhaps it would be more accurate to say that the levels or amplitudes of ground motions may not be indicative of the final hazard results that are based on the inclusion of the full SWUS GMC model. 934 Line The figures and text refer variously to "annual frequency of exceedance Line 49 and The figures have been edited and updated. 119 (AFE), annual exceedance probability (AEP), and annual exceedance of elsewhere probability." Please make them consistent throughout figures and text. 935 Line There is actually a visible difference in hazard in Figure 14-1a at AFEs Lines 61-69 Although as noted there is a difference in the hazard 121. greater than 10-4. Is there a reason that it is not noted here? If it is not curves for AEPs of 10-4 and greater, the primary focus Figure significant, please so state. for this study is for AEPs in the range of 10** to 10*6* 14-1a 936 Line Please discuss the reasons for the differences in hazard level between Line 66 and Although we do not want to speculate in the text, the 125 the 2015 SSC and 2011 Shoreline models. In particular. why has hazard Figure 14-1 difference in hazard results for low frequency (long dropped systematically for the low ground motion levels. and increased period) motion may result from an increase in systematically (at least in the 05 Hz case) at high ground motion levels? magnitudes considered for the Hosgri fault in the 2015 SSC model relative to the 2011 model. For higher frequencies, the smaller magnitude earthquakes tend to contribute relatively more to the total hazard than the larger magnitude events. Given the location and magnitude distribution of the Local areal source zone, this leads to a relatively larger contribution of this source to the total hazard for the 5 Hz versus 0.5 Hz cases. We prefer that the text focus on documentation of the SSC model and not on discussion of the hazard results 937 Lines It might help the reader by stating something like For example, as shown Lines 77-83 Additional clarification provided. 133-136 in Figure 14-1a. the mean AEP associated with at 5 Hz spectral acceleration of 1 g is about 10-3. 938 Line Replace "past" with "previous" Line 99 Revision accepted 154 939 Line An explanation for the contribution at higher frequencies made by the No change to Once again, we prefer that the text focus on 158 IHEB source zone would be helpful to the reader. text documentation of the SSC model and not on discussion of the hazard results. As stated above, for higher frequencies, the smaller magnitude earthquakes tend to contribute relatively more to the total hazard than the larger magnitude events. Given the location and magnitude distribution of the Local areal source, this leads to a relatively larger contribution of this source to the total hazard for the 5 Hz versus 0.5 Hz cases. 940 Line Please compare the relative hazard from the Local areal source zone with No change to We prefer that the text focus on documentation of the 163-165 the corresponding result from the 2011 Shoreline model and discuss text SSC model and not on discussion of the PSHA results possible explanations for any differences. 941 Lines Any explanation why the SA contributes at the lower ground motions? It is Lines 111-113 We agree. The larger earthquakes at greater distance 165-167 likely related to the relatively high rate of occurrence of large earthquakes on the SA contribute at lower frequency (0.5 Hz) but not on the SA. but the great distance lowers the likelihood of larger ground at higher frequency (5 Hz) motions. 942 Lines Consider noting that such an observation is not unusual for site-specific Lines 126-131 Additional clarification is provided. 182-185 hazard results. 943 Line Please make reference to the specific section of the report that describes Line 134 Section 9.3 describes the allocation of fault slip rate to 188 these logic tree branches and weights. rupture sources. and presents the logic tree branches and weights. Reference has been added to the text. The discussion of slip rate for each fault is given in Chapter COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT 8. 944 Line Please explain why this simplifying assumption is made (these are the Lines 136-139 Yes. Additional clarification is provided. 192 highest weighted FGMs?) 945 Line Please explain why these AEPs are used for the display. Line 147 and These AEPs are used because this is the AEP range of 200 Lines 64-65 interest for nuclear sites. The introduction to Section 14.2 is corrected to reflect this. 946 Lines The weights on Line 231 give the appearance of being rounded No change to The weights shown on line 205 are for slip rate; the 205 and representations of the weights on Line 205. If this is so. please clarify why text weights shown on line 231 are for FGM. They are not 231 one case was rounded and the other not. And, in any event, please clarify rounded from one another. When weights are assigned why the weights on Line 205 are expressed to such high precision while by judgment, they are typically given to the nearest those on 231 are not. tenth; when weights are assigned from a three-point sample of a continuous distribution using Keefer and Bodily ( 1983 l, they are shown with qreater precision. 947 Line Replace "as" with "and" Line 161 Revision accepted. 214 948 Lines Please discuss the factors which may account for the stated differences in No change to Although we do not want to speculate in the text. the 222-225 hazard from the three FGMs. text difference in hazard results may relate to hanging wall effects associated with the more gently dipping faults in the SW and NE models relative to the OV Model. 949 Line Replace "unit" with "unity." Line 174 Revision accepted 224 950 Line Figure 14-8. Please provide figure captions and spell out abbreviations. Figure 14.8 Figures have been improved for clarity. 227 Would be helpful if figures and figure captions were self explanatory. and others 951 Line Replace "done" with "performed" Lines 188 and Revision accepted 238 and 190 240 952 Line This is not the "standard" for host zones any longer (e.g .. CEUS SSC Lines 189 Revision accepted. 239 model, Hanford PSHA. BC Hydro, etc.). Suggest deleting "in a more standard way". 953 Lines One might have speculated that smaller dip would decrease the average No change to We prefer that the text focus on documentation of the 252-259 Rjb distance of DCPP from the virtual faults, and thereby would affect text SSC model and not on discussion of the hazard results. hazard measurably. Please consider whether some simple explanation Although the change in dip angle and associated can be provided for why this is not what is seen in the sensitivity analysis. hanging wall and RJB distances would have an impact on the contribution from the Local areal source individually, its relative contribution to the total hazard reduces the impact on the total ground motion change as shown in the tornado results. 954 Line The section heading, figure captions, and most of the text. describe this Line 209 It could be separated but this would lead to a single plot 260 as a section on time dependency. But the complex and splay mechanism for just the splay/complex case. Section heading is (general sensitivities are tucked away in this section too. Anyone scanning the revised to add Complex and Splay rupture sensitivity for com me chapter or figures for the latter sensitivities will likely not find them. Please transparency. nt on consider making the full purpose of the section and its figures more section transparent. 14.2.61 955 Lines This is not necessarily expected." The contribution to hazard uncertainty Line 214 Text revised to delete "as expected". 265-266 that the EPR branches make could be small if the range of EPR values was small-despite the dominant contribution of the Hosgri fault to the hazard. In other words. the large contribution of the Hosgri fault to the hazard means that the details of the characterization of that source are generally more important than other sources. But that does not mean that any given characteristic of that source will contribute significantly to the hazard. The EPR is one that does. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT 956 Lines The sensitivity to Hosgri EPR appears to be significantly higher for 0.5 Hz No change to We prefer that the text focus on documentation of the 265-269 than for 5.0 Hz. If this is a correct understanding, please comment on it text SSC model and not on discussion of the hazard results. and if possible suggest an explanation. The percent contribution of the Hosgri fault at both AEPs is slightly greater for 0.5 Hz relative to the 5 Hz case, which leads to a larger range in the tornado results. This may be due to the larger magnitudes characterized for the Hosgri fault than for other sources. For lower frequencies, the larger magnitude earthquakes tend to contribute relatively more to the total hazard than the smaller magnitude events. 957 Lines Interesting, in that the SAF is known to be at or near the end of the Lines 214-215 Relative contribution of the SAF to the total hazard is low 269-272 seismic cycle -why doesn't this have more of an effect? compared to the other sources shown here, so changes to this individual hazard curve do not significantly chanoe the total around motion values. 958 Lines Consider adding the phrase to the end of the sentence "'due to the lack of Lines 231-232 Additional clarification is provided. 282-283 including the secondary (or splay) rupture event." 959 Lines Please discuss this a little further. Does this reflect that those ruptures are Lines 234-236 We prefer that the text focus on documentation of the 285-287 very infrequent in the model and therefore contribute very little to hazard SSC model and not on discussion of the hazard results. to begin with? Or does it reflect the dominance of the primary rupture, This result very likely reflects the infrequency of these such that the SSRS is little affected by the secondary rupture? Or both? ruptures in the model 960 Lines More accurately, the inclusion of the complex (or splay) ruptures or not Lines 234-236 These results show the impact on how the 286-287 does not have a significant contribution to the uncertainty in the total splay/complex sources are modeled in terms of their hazard. ground motion compared to ground motions that would result from modeling just the primary (or main) rupture. The text has been modified to reflect this. 961 Line Replace "unit" with "unity" Line 254 Revision accepted 303 962 Lines Please provide an explanation for why this is the case. Lines 263-266 We prefer that the text focus on documentation of the 312-316 SSC model and not on discussion of the hazard result. For 10*6 at 0.5 Hz, the characteristic earthquake magnitude PDF may be lower because of a lack of rare large events that are contained in the WAACY model. For lower frequencies, the larger magnitude earthquakes tend to contribute relatively more to the total hazard than the smaller maonitude events. 963 Lines Please provide an explanation for why this is the result. Lines 282-284 We prefer that the text focus on documentation of the 331-335 SSC model and not on discussion of the hazard result This result suggests that the relatively rare large events represented by the high M * .,, alternative contribute to hazard uncertainty at very low AEP (i.e., 10*6) and low freouency (0.5 Hzl. 964 Line Should *'plots" be singular? Line 293 Text has been clarified 343 965 Lines This explanation needs bolstering. Is it only the proximity of the Hosgri Lines 300-305 Text has been clarified/bolstered 353-354 fault to the site? Both the slip rate and the EPR are directly tied to the recurrence rate, is that why they contribute most to the uncertainty in hazard? The Hosgri fault's slip rate is 1-2 orders of magnitude greater than any other nearby fault AND it is close to the site. Why not spell out why this result is expected, as this is the concludino punch of the chapter. December 14, 2014 Mr. Kent S. Ferre Project Manager Pacific Gas & Electric Company 245 Market St. San Francisco, CA 94177

SUBJECT:

Participatory Peer Review Panel Letter No. 1: DCPP SSC SSHAC Project Draft Report Installment #1

Dear Mr. Ferre,

This letter provides in writing the comments of the Participatory Peer Review Panel (PPRP) on the Diablo Canyon Seismic Source Characterization (SSC) SSHAC Project Draft Report. We (Coppersmith, Day, Rockwell, and Driscoll), the designated PPRP, want to express our appreciation for the opportunity to review Installment #1 of the Draft Report, which consists of Chapters 1 -5, and 8. Our review comments are provided in the attached table and each comment is associated with a unique number. We will consecutively number our comments in future transmittals for clarity. The table includes a column for the Tl Team to summarize the revisions made to the report to respond to each comment. We would request that a completed copy of the table be returned to us with the revised report to expedite our follow-up review. We look forward to answering any questions of clarification regarding these comments during our conference call on Wednesday, December 17, 2014. Sincerely, DCPP SSC PPRP K. Coppersmith, Chair S. Day N. Driscoll T. Rockwell ATIACHMENT PPRP COMMENTS ON DCPP SSC DRAFT REPORT INSTALLMENT #1 Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report General Comments The report is generally well written and comprehensive. The entire text would benefit from a thorough technical edit. This edit would ensure the consistent use of tense throughout the text, maintain the consistent use of the third person, ensure the 1 consistent use of terminology, remove redundancies from section to section, and correct typographic errors. We have not attempted to provide such a technical edit in this review but have focused on technical justification and clarity. In some cases, where errors are obvious to us, we have noted those. In several instances, the absence of figure captions detracts from the usefulness of the figures. Figure titles are important, but they do not provide the link from the image to the technical arguments being made in the text. We strongly urge that figure captions be developed for all of the figures that provide a summary of the salient elements of the figures that are being presented, and the key technical conclusions that the authors 2 would like to portray. The fundamental technical arguments and detail will still reside in the main text, but the figures will carry additional meaning when they are accompanied by captions that highlight those arguments. Further, the captions will provide an opportunity for the various panels of a figure to be defined and discussed, without forcing the reader to flip back and forth between the main text discussions and the figure. Figure captioning of the type requested is standard for a report of this kind. We recognize that the SSHAC process allows for the 3 consideration by the Tl Team of all data, models, and methods that exist within the larger technical community, including those 1 Unless otherwise indicated, paragraphs identified are for the section, rather than on the page cited. Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report that have been developed within a QA environment, the peer-reviewed literature, unpublished reports, or otherwise. A vitally important part of the documentation process is the attribution of those data, models, and methods by exhaustive referencing throughout the report. Thus, many of our comments call for more complete referencing of the technical conclusions and assertions made in the text. It is particularly important to indicate which technical assessments have been taken from other sources (with proper referencing) and which have come from the Tl Team itself. In the hierarchy of sources of information, we consider personal communications to be the least defensible, due to the general inability of the report reader to verify their accuracy. We therefore urge the authors to avoid reference to personal communications if at all possible. If any cited source can be made (e.g., reference to abstracts for presentations at professional conferences, reference to presentations made at the workshops and documented in the workshop summaries, papers that have been accepted for publication but not yet published), that would be preferable to a personal communication. If there is no other reference to cite, please consider whether the technical conclusion being made is vital to the SSC model and whether it can be removed from the report. If the conclusion is vital and a personal communication is the only source of information, please consider adding documentation to the report in the form of an aooendix. We recognize the need to develop the report in installments in order to meet the project schedules; however, this precludes our ability at this stage to provide intelligent comments on the accuracy of cross-references. We urge the authors to provide the most specific cross-referencing possible to assist the reader in understanding the technical arguments being made. For 4 example, given the scale of this report and the complexity of the technical issues, cross-referencing is essential to guide the reader in seeing how the evaluation of data has led to the development of the SSC model. As the arguments are developed, links within the text will be needed to refer to the specific sections and subsections of the report where the information lies. Simple reference to an entire chapter is not Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report helpful, but reference to specific subsections will be most useful. Hence. once all sections have been written, it is strongly recommended that a single author read through and edit the document with the appropriate detailed cross-references. Reviewing a report in installments is not ideal but required in this case. Without seeing how the sections in this installment interface with other sections, there is a certain amount of faith that we must have that the technical data and arguments made 5 in other sections will support the positions taken in this installment. Although the comments made in this round of PPRP review provide a comprehensive review at this point in time, we reserve the right to provide additional commentary on the sections of Installment #1 in the future after we have reviewed later sections of the report. Chapter 1 6 Section 1.0, p. 17, 1st Suggest adding " ... ground motion at the site as a function ... " paragraph, last sentence 7 Section 1.0, p. 17, 1st Please specify if this SSC report will also be an attachment to paragraph, 4th sentence PG&E 2015. 8 Section 1.0, page 17, 2nd Will PG&E documents (e.g., 2015 and others referred to in text) paragraph 7th line down be accessible on PG&E/LCI share drive? 9 Section 1, Page 17, ." ... was conducted from June 2011 to January 2015. Please Paragraph 2, line 8 change to February 2015, as this date is more realistic. 10 Section 1, Page 17, Please include the specific date of the kick-off meeting. Paragraph 2, line 9 11 Section 1.0, p. 17, 2nd 35 working meetings are identified on page 28 and Table 3-1. paragraph, line 10 Please clarify. Section 1.1. p. 18. 1st A careful reading of Chapter 6 of NUREG-2117 shows that the 12 paragraph. 1st line options are accept, refine. or replace. There is no "revise." Please clarify that the decision here is to replace. 13 Section 1.1. Page 18. Please define ISFSI with first usage. Paragraph 2. Line 3 Section 1.1. page 18. 2nd Will (in prep) documents be made available-Wooddell et al. (in 14 paragraph 14th line down prep); please see General Comments regarding such citations. 15 Section 1.1. Page 18. " ... regional GPS data. and several offshore studies and Paragraph 2. line 10 seismicity studies ... " Please indicate what types of offshore Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report studies were conducted. Geologic? Seismic? Section 1.1, Page 18, Please cite published report(s) and/or journal article(s) for 16 paragraph 2, Line 12: UCERF 3, and update the Wooddell et al. citation if report or paper is published (and if not, cite the section of the report where that work is presented). Section 1.1, p. 18, 211d The presence of new data, models, and methods requires that 17 paragraph, last sentence they be evaluated, as defined in NUREG-2117. They do not necessarily need to be incorporated into the SSC model, particularly if they are not found to be technically defensible. Section 1.1.1, 1st This is actually an existing regulation pertaining to license 18 paragraph, p.18, first conditions. The NRG therefore did not "issue" 50.54(f). They sentence issued a request for information pursuant to the regulation and related to NTTF recommendations. Section 1.1.1, Page 19, " ... site specific earthquake ground motion" addresses should 19 Paragraph 2, line 7 use ... " This statement is unclear. Please clarify what is meant by "addresses". Section 1.1.1, Page 19, Coppersmith and Bommer (2012) is not listed in the chapter 20 3rd paragraph of section, references section Line 4: Section 1.1.2, Page 19, Please consider referencing the report chapter that presents the 21 1s1 paragraph of section, sensitivity studies. 2nd sentence: Section 1.1.2, Page 19, Consider whether "complete" is the right word here. 22 1st paragraph of section, line 5: Section 1.1.2, Page 19, In the first bulleted line, are location and geometry the only foci 23 Paragraph 1 in the identification and characterization of active faults near the site? Consider also kinematics, rates. and recency of motion. Section 1.1.2, p. 19, The use of the term "explore" implies that some things were second bullet looked at (explored), but weren't necessary included. For 24 example. exploratory studies are a type of sensitivity analysis. If the intent here is to say that the range of uncertainty was "defined" and/or "included", then consider changing the terminoloav. 25 Section 1.1.2. Page 19-Please consider the suggestion to reference the report 20, bulleted list: section(s) appropriate to each bulleted item. 26 Section 1.1.2, Paoe 20, "Development of fault fault rupture models" that ... " Please Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report 1st bulleted line on page delete fault. Section 1.1.2, Page 20, If this is the first reference to "linked ruptures, complex ruptures, 27 1st bulleted line on page and splay ruptures", please define or include a reference to report section or other source where they are defined. 28 Section 1.1.2, Page 20, Please rephrase, as this is a run-on sentence. 3rd bulleted line on page Section 1.1.2, Page 20, Please change "incorporates" to "incorporate" as this refers to 29 4th bulleted line on page "models" (plural) Section 1.2, Page 20, Please correct "strike-slip" 30 Paragraph 1 of section, line9. Section 1.2, Page 21, last Please note typo and clarify number of Tl Team members. 31 paragraph of section, Lines 7-8: 32 Section 1.2, page 21, 3rd Three of six members four of five members not affiliated -paraqraph, 7th line down unclear which one? Section 1.2, Page 21, The 3rd subphrase "(3) ... new methods and .. . Are you Paragraph 3, line 10. referring to new data? What new methods were used? 30 33 seismic is not a new method, although it is newly applied to the SSC for DCPP. Please clarify what "fundamentally new methods" were applied. 34 Section 1.3, Page 21, 1st "provides our evaluation" -please specify who "our" refers to -numbered paragraph the Tl Team? Section 1.5, pages 23-24 The references need to be correctly formatted. For instance, 35 there is a U.S. NRC, 2012 and U.S. Nuclear Regulatory Commission 2012a. 2012b, and 2012c. Please correct these references here and in the text Chapter 2 Section 2.1. 1, p. 25, 2nd An opinion is a belief that does not require facts or evidence. 36 paragraph. 2nd sentence Judgment is the evaluation of evidence to make a decision. Suggest replacing "opinion" with "judgment." 37 Section 2.2. Page 27. 3rd " ... provided for bringing all members of the project team .. . paragraph, line 3 This is awkward. Please rewrite for clarity 38 Section 2.2.1, Page 27, Please note word repetition. last sentence of section: 39 Section 2.2.3, Page 28, "uncertainty" Consider pluralizing this word. Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report Paragraph 2. line 7 Section 2.2.3, page 28, Please clarify or correct the apparent conflict between this line 40 3rd paragraph of section, ("35 working meetings"} and Section 1.0, paragraph 2, Line 11, Line 2: ("53 Working Meetings"). 41 Section 2.2.3, Page 29, In reference to UCERF, are you referring to UCERF3? If so, Paragraph 8, line 18 please state. Section 2.2.3, page 29, It would be clearer if Dr. Lettis were included in this list, e.g.," .. 42 last paragraph on page, consisted, in addition to Dr. Lettis, of Dr. ... " Line 2: Section 2.2.3, page 29, Please resolve the conflict between this statement that Ms. 43 last paragraph on page, Hanson was added after Workshop 2, with the statement in Line 8: Section 1.4, page 23, line 8-9 on page, that says that Ms. Hanson was added "FollowinQ Workshop 3". Section 2.2.3, page 29, Please check whether the sentence (stating that the Tl Team 44 last paragraph on page, remained stable throughout the data integration and model Lines 11-12: building process} is strictly correct given that Kathryn Hanson joined the Tl Team after Workshop 3 (if that is the case}. Section 2.2.3, page 30, Inasmuch as "Mr. AbramsonWard and Dr. Thompson were 45 Line 2: younger scientists," please clarify whether the use of past tense here means they are now elderly scientists. 46 Section 2.2.4, Page 30, You might also mention that Dr. Rockwell worked on the LTSP Paragraph 2. line 14 in the 1980's Section 2.2.4, page 30, Please consider whether this statement is correctly phrased, 47 Paragraph 2 of section, given that Dr. Day's only other SSHAC Level 3 experience is Line 10: concurrent with this SSC study. Section 2.2.4, Page 30, Should read: "For Workshop 3, the members of the PPRP ... " 48 Paragraph 3. line 6 Section 2.2.4, page 30. Professor of Geology and Geophysics at Scripps 49 2nd paragraph, 5 lines down Section 2.2.4, page 31. For completeness. please also note the PPRP's responsibility to 50 listed items in 4th review the Project Plan. paragraph of section: 51 Section 2.2.4, Page Inconsistent usage of periods at the end of each bullet. Please 31,bulleted items make them all the same. 52 Section 2.2.5, p. 31, last In Figure 2-1, SSC Tl Team Staff Support is indicated by an sentence asterisk as being EEs. Is this correct? Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report Section 2.2.6, p. 31, P1 Of course. the REs did not present "raw" data without 53 paragraph, line 6 interpretation. The important point is that the REs avoid providing their interpretations of the data relative to SSC issues. That is the purview of the Tl Team. Section 2.2.6, page 32 Please replace "several" with "some." 54 1st paragraph 2nd to last line 55 Section 2.2.8, page 32, Please make Analyst was to "Analysts were" 1st paragraph 2nd line Section 2.2.8, page 32, Ms. Wooddell is identified as one of the Hazard Analysts, but 56 3rd to last line: her name does not appear in Figure 2-1 (the project organizational chart). Section 2.2.7, p. 32, last To avoid confusion of roles, consider adding a statement that all sentence participants were made aware of the fact that members of the Tl 57 Team were assuming the role of PE for purposes of the workshop, and they would then return to their roles as EE and Els. Section 2.2.8, p. 32, line Affiliations were given for the people identified above; consider 58 7 if they should be provided here as well. Likewise for Serkan Bozkurt in the next paragraph. Section 2.3, Section title: Please consider changing the title to emphasize the studies 59 rather than the contractors (i.e., the section is about the studies, the contractors being important but subordinate information). Section 2.3, p. 33 It may be useful to explain either in this paragraph or in Section 2.3.2 what the relationship is between the focus of the CRADA and the studies conducted specifically for Diablo Canyon. It may 60 be important to distinguish the role of the USGS, which conducts research for non-site specific applications. versus 1632 studies that are aimed at reducing uncertainties for the DCPP PSHA. Section 2.3. page 33. 2nd Please consider rewording this to reflect the fact that you are 61 to last sentence: summarizing focused studies done by contractors to PG&E (you mention the contractors as part of that summary, but you aren't merely compiling a list of contractors here). Section 2.3. 1, Page 33, Is the Diablo Cove fault considered "potentially active? Please 62 line9 refer to subsequent discussion of evidence of Quaternary activity on this fault. In line 14, is the Shoreline-Diablo Cove Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report fault interaction actually considered in this SSC? Section 2.3.2, Page 34, " ... and to evaluate slip rate on the Hosgri fault zone." Didn't 63 line 5 Sam Johnson actually "develop new slip rate data on the Hosgri fault zone."?? Section 2.3.2, Page 34, "lineaments in Estero Bay." What type of lineaments? 64 line8 Topographic? 65 Section 2.3.3, Page 34, "San Francisco State" should read "San Francisco State line9. University" Section 2.3.4, Page 34, "San Francisco State" should read "San Francisco State 66 line 3. University" Also, the second line of this paragraph seems redundant with the previous paraqraph/section. Section 2.3.4, page 34, It is not clear how the listed studies by Tl Team members are to 67 last sentence of section: be distinguished from "independent new detailed studies." If the intent of the sentence is to clarify the scope of Tl Team efforts, please reword. Table 2-1, Page 35 Jan Rietman is stated as being affiliated with FUGRO in the text and as a consultant in the table-please make consistent. 68 Also, please consider ordering the names alphabetically -this will eliminate the double naming of participants, as with Phil Hogan in Workshop #2 (listed twice). Section 2.3.5, p. 35, 2nd The Tl Team members in a SSHAC process are expected to paragraph evaluate ALL forms of data, models, and methods. This includes data gathered under a QA program, data provided in peer reviewed publications, and data gathered for other 69 purposes. This is because the experts on the Team are capable of evaluating the quality and applicability of those data. models, and methods. This does not mean that the data are "accepted into the SSHAC process" but that the data have been evaluated according to the SSHAC process. Suggest revising the wording in this sentence. Chapter 3 Section 3.1. p. 38, znd In Figure 3-1, there are called "essential steps." To avoid 70 paragraph confusion with the "essential steps" identified in Chapter 4 of NUREG-2117, suggest calling these four "components" as done in the text. Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report Section 3.1. 1, p. 39, 4th To avoid any perception that the PPRP was actually involved in 71 paragraph. last sentence the technical integration process, suggest substituting the term "reviewed," or something similar, for "involved." 72 Section 3.2, p. 40, last Where do these Working Meeting summaries" reside in the sentence project records? Section 3.2.1, general Please consider reserving the term "Workshop" for those comment: activities specifically defined as workshops in the SSHAC 73 NUREG documents (for example, Workshops 1,2, and 3 are structured quite formally and documented thoroughly, including a PPRP feedback letter; this was not the case for the kickoff meetinQ). 74 Section 3.2.2, Page 41, Here and elsewhere, please do not use "etc. List out any other Paragraph 2, line 9 items. Section 3.2.3, Page 42, significant parameters and features. Please clarify what is line9 " meant and implied here. Issues? Data? Interpretations? What 75 are parameters and features?? 76 Section 3.2.4, Page 42, Consider changing " ... and input into ... " to " ... and added to .. " Paragraph 1, line 4 77 Section 3.2.5, Page 43, "overlapping day with the GMC to discuss ... " Do you mean Paragraph 1, line 6 GMC Tl Team? Please clarify. 78 Section 3.2.5, Page 43, Please delete "etc." and list out any other items. Paragraph 2. line 10 79 Section 3.2.6, Page 44, "Several of the working meetings were observed ... " This is Paragraph 3, line 13/14 redundant with the previous paragraph -already stated. 80 Section 3.2.7, Page 45, " ... used to form the basis development of ... " This statement is Paragraph 3, line 5 unclear. Please clarify 81 Section 3.2.7, Page 45, Please indicate where the summary and PPRP letter are Paragraph 4, last line located. 82 Section 3.2.8, p. 46, 1st Are these the same as the WM Summaries identified on page paragraph. last sentence 40? 83 Section 3.2.9, Page 47, Please delete "etc." and list out any other items. Paragraph 2, line 9 84 Section 3.2. 1 O. Page 48. " ... the final model in light of the ... " Consider changing "in light Paragraph 1. line 6 of" to "using" to improve clarity. 85 Section 3.2. 1 O. Page 48. Please add "fault" after "Hosgri". as it is a formal name. Paragraph 2, line 7 Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report Chapter 4 86 Section 4.1, Page 51, Please define FSAR if this is the first usage of this term. Paragraph 4, line 2 87 Section 4.2.1, Page 51, "proposed Diablo Cove fault" -Is it a fault, or not? Please last line clarify "proposed" 88 Section 4.2.2, Page 52, The bulleted items do not have a parallel sentence structure bulleted items with the intro. Each should read correctly after" .... included:" 89 Section 4.2.2, page 52, University of Berkeley-University of California, Berkeley? 2nd paragraph, last line 90 Section 4.2.3, Page 52, The first bulleted paragraph is confusing. Please rewrite for 1st bulleted item clarity. Section 4.2.4, page 53, If this is the first occurrence of the acronym LESS, please define 91 1st paragraph of section, (it may be used freely thereafter, since it does appear in the Line 4: acronym table). Also, suggest putting "New" prior to Offshore 92 Section 4.3.1, Page 54, "Report" is repeated, but the acronym does not have an R. Is Paragraph 1, line 6. report part of the official title? Not clear. Section 4.3.1, page 55, "Low-Energy Seismic Survey" and "Onshore Seismic 93 3rd paragraph of section, Interpretation Project" should be written with initial capital last 3 lines of section, letters. Section 4.3. 1.1, page 55, If this is the first occurrence of the acronym HFZ, please define 94 1st paragraph, Line 4: (It appears in the acronym table, so it may be used freely thereafter). Section 4.3.2.1, Page 56, Non-parallel structure and confusing. Suggest " ... to the Hosgri 95 Paragraph 2. lines 4 and fault zone, were spaced -800 m apart {locally 400 m) along an 5 -94 km-long portion of the Hosgri fault zone, and crossed the fault zone 121 times." 96 Section 4.3.2.1. Page 57. Check spelling of "transect" Paragraph 3, line 4 97 Section 4.3.2.1. Page 57. "available at CSUMB (2010)." Is this a published source? It is Paragraph 4, line 4 not in the listed references. Please include. Section 4.3.2.1. Page 57. Sentence is incomplete; please check and correct. 98 5th paragraph of section, 1st sentence: Section 4.3.2.2. page 57, "tomoDD velocity model" is very specialized jargon. in the sense 99 1st paragraph of section, that "tomoDD" is the name of the computer program that Line 3 implements a particular analytical method. Please consider Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report rewording. either simplifying to "seismic velocity model". or to something that references the underlying analytical method, e.g., "seismic velocity model based on double-difference tomography". 100 Section 4.3.2.3, Page 58, Suggest moving "by" after (1) to be consistent with rest of Paragraph 1 paragraph. Section 4.3.2.4, Page 58, This sentence is confusing. " ... are incorporated into the 101 Paragraph 2 characterization of the Irish Hills-Estero Bay Local Areal Source Zone Irish Hills-that includes the Irish Hills." Please clarify. 102 Section 4.3.2.5. 1, page Reference section gives author name as Murray-Moraleda, 59, 1st paragraph, Line 1: which is not consistent with the citation in this paragraph. 103 Section 4.3.2.5.3, Page Rinconada fault2??? Are there two Rinconada faults? Is this a 59, ParaQraph 1, line 6 typo? Please clarify. Section 4.3.2.5. 1, page The citation is consistent with the reference section entry, but 104 59, 1st paragraph, Last not with the citation at the beginning of the paragraph. line: 105 Section 4.3.2.8, page 61, "San Luis/Pismo" is written "San Lui-Pismo" in the list of 1st bulleted item: abbreviations and acronyms. 106 Section 4.3.2.9, Page 62, Please rewrite this paragraph for clarity. Paragraph 1 Chapter 5 107 Section 5.2, page 69 Both SYRF and SYF labeled on Figure for Santa Ynez River Figure 5-1 Fault. Please make consistent. Section 5.2, Page 67, States that the contemporary plate boundary is a zone of strike paragraph 1, lines 4-5 slip faults and transpressional deformation, but wasn't the San 108 Simeon earthquake purely thrust? Plus, two of the structural models have the San Luis Bay and Los Osos as thrust faults. Is this statement correct? Please clarify. Section 5.2. Page 68. In the preceding section, the region is referred to as " ... zone of 109 Paragraph 2. line 1 right-lateral strike-slip faults ... ", whereas many of the faults shown in Figure 5.1 are left-lateral or oblique left lateral (Santa Ynez, Lion's Head, Casmalia, etc.). Please clarify. Section 5.2. 1, Page 68, Please add a reference for these ages: "(approximately 200 to Paragraph 1. line 1 66 Ma)". 66 Ma may be a bit young for the cessation of 110 subduction-related volcanism. as Sierran volcanism and pluton emplacement shut down by about 80 Ma, and it was even earlier in the southern California Peninsular Ranges (95 Ma). Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report Are you suggesting that subduction ceased at 66 Ma? Clearly, as stated earlier, the spreading ridge intersected the trench at about 28 Ma and flat-slab subduction was occurring after -80 Ma (hence, the cessation of Sierran volcanism). This section would benefit from additional supporting discussion and improved referencing. 111 Section 5.2.2, p. 69, 3rd Would it be helpful to mention the seismicity that is also paragraph, line 8 projected on to the cross section in Figure 5-4? Section 5.2.2, page 69 Please provide more information or reference to support 112 3nd paragraph 10 lines "surface slab does not appear to be disrupted by crustal faults" . down Is this based on microseismitv?? Section 5.2.2, p. 69, 3rd Please provide the basis for this interpretation or make 113 paragraph, second to last reference to a section of the report where the issue of the top of sentence the slab relative to the Hosgri fault is discussed further. Section 5.2.3, page 70, Onderdonk (2007) is cited but does not appear in the references 114 2nd paragraph of section, section. Line 7: Section 5.2.2, Page 69, It is stated here that subduction ceased 22-20 Ma at the latitude 3rd Paragraph, line 7 of DCPP, but it is earlier stated that the spreading ridge 115 contacted the subduction zone "directly south" of DCPP, which would imply a timing close to 28 Ma. In contrast, figure 5-3 suggests that contact occurred near present-day Los Angeles. Please clarify or correct. Section 5.2.2, Page 69, There is a lot of detail with no referencing, and alternative 2nd

• 3rd and 4th interpretations have been proposed in the literature. For Paragraphs instance, the notion that the main plate boundary jumped inland at 5 Ma is contradicted by many studies. There was clearly part of the main plate boundary already inland by 12 Ma -hence the 116 Miocene activity of the San Gabriel fault and the development of Ridge Basin (Crowell refs). Oskin and Stock argue for an earlier opening of the Gulf. as does Fletcher, and that the "proto-Gulf' is really no different than the modern Gulf of California, except where the locus of extension occurred. Please provide complete referencing in these paragraphs. Section 5.2.2, Page 70, "full plate motion of 30 to 35 mm/yr during the late Miocene." 117 5th Paragraph, line 2 According to many references, the full plate motion during the late Miocene was no different than it is today --52 mm/yr.

Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report Please provide additional justification and references, and soecifv the timinq of the increase in rate (12 Ma?) 118 Section 5.2.3, page 71, Please complete the citation for Atwater (2011} or provide an 4th paragraph, line 4 online URL. Section 5.2.3, page 71, If the San Miguelita and Edna faults were active at this time with 119 4th paragraph, line 8 lateral slip, the model requires them to be left-lateral. Is this model consistent with observations? Please elaborate. Section 5.2.3, page 71, Please consider whether the topic of "early sinistral transtension 5th paragraph, last between blocks and later dextral transpression" is discussed in sentence. Wilson et al., 2005. The paper is focused on the correlation of 120 volcanism and slab windows and does not appear to address the topic identified. If it does not, please provide a proper citation for this concept. Also, please explain why many of the E to NE-striking faults (Santa Ynez, Lions Head, etc.} continue to have late Quaternary left lateral or oblique LL motion. Section 5.2.3, page 72, Here it is stated 6.3 to 4.7 Ma. Earlier 5 Ma is used. Please be 121 6th paragraph, line 9 from consistent and provide a reference for this timing. top of page Section 5.2.4, Page 72, Please provide a reference for the statement that rotation in the Paragraph 1. line 3 WTR has stopped. This is a key issue as it affects expected motion on W-NW striking faults in the Santa Maria basin 122 province (Los Osos domain} -should see continued left-lateral oblique slip if rotation continues. At least some faults remain active, and Holocene left-lateral has been demonstrated on the Santa Ynez fault. Section 5.2.4, page 72. Please replace Carreaga with Careaga 123 1st paragraph 3rd to last line Section 5.2.5, Page 73, What sense of strike-slip? -please indicate. Within the Los Paragraph 2. line 4 Osos domain, the Shoreline fault is presumed to be right-lateral based on seismicity and observed offsets. whereas the San 124 Ynez fault is left-lateral in the Holocene. Other faults, such as Casmalia, Lions Head, Santa Ynez River faults, may be left oblique in terms of overall displacement, but Holocene slip and kinematics is not well-documented. Please explain the inter-relationship of these structures and how thev can be riqht-lateral Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report near the Hosgri and left-lateral farther inland. Section 5.2.5, Page 73, Here it is stated that faults in the Los Osos domain are dextral Paragraph 3, line 2 or oblique. Does this include the Santa Ynez and other sinistral 125 faults? These relationships should be explained. It is stated later that the San Luis Bay fault is reverse to left oblique based on kinematic indicators. Please provide clarification. Section 5.2.5, Page 74, Here the concept is introduced of continued clockwise rotation 126 Paragraph 3, 3rd bulleted of the WTR. If correct, this could cause a component of left slip item on all of the faults in the Los Osos domain, as they are being extruded to the NW. How does this work -please explain. 127 Section 5.2.5, Page 74, Please provide a reference to support the last line of this Paragraph 4, last line paragraph, which starts: "Evidence for downdropped or static ... " Section 5.2.5, Page 74, Please provide a reference for the statement that the San 128 Paragraph 6, line 2,3 Miguelita, Edna, and Pismo faults do not deform Quaternary deposits. Also, please specify where -the Edna may not be active in the Irish Hills, but may be active to the east. Section 5.2.6, Page 75, If the Los Osos domain is undergoing transpressional dextral 129 opening paragraph shear, consider whether this would preclude shortening due to continued rotation of the WTR. 130 Section 5.2.6, Figure 5-11 Please explain why only two solutions are shown for the HASH data. Are there sufficient data for more solutions? Section 5.2.6 Figure 5-13 This appears to be a minimum rate based on data (red dashed 131 line). Please provide more explanation on how the budget was determined. 132 Section 5.2.6, page 75, Please check spelling of Zheng (isn't this Yuehua Zeng?) 2nd bullet Section 5.2.6, page 76. Lewandowski and Unruh (2014) is not in the references. 133 2nd paragraph of section. Line 1: Section 5.2.6, page 76. DeMets (2012) is not in the references. 134 2nd paragraph of section. Line 4: Section 5.2.6, page 76. d3/s1 could be mistaken for a ratio, so please consider stating 135 2nd paragraph of section. this differently. 4 lines from end: 136 Section 5.2.6, page 76, Please indicate how the cited results differ from published work Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report 3rd paragraph of section, of DeMets (2012). and state the basis for those differences (or 2nd and 3rd sentences: reference the relevant part of the report). 137 Section 5.2.6 Figure 5-15 Annotations need to be rotated, also OWH has a p = 1.1 mm/yr? Section 5.3, Page 77, 1st Since the sensitivity results are being used to limit the selection 138 sentence: of faults for discussion, please provide a reference to somewhere in the report where those sensitivity studies are documented. Section 5.3, p. 77, pt Consider whether it would worthwhile in this introduction to paragraph discuss the concept of defining each fault according to its 139 characteristics along the reach closest to the site. It could be important to remind the reader that this is NOT a regional fault characterization {e.g., UCERF3), but a site specific SSC model. Section 5.2.6, page 77, "The model results showed more evidence for northeast-4th paragraph, 9 lines southwest directed contraction between the Los Osos domain 140 down (east of the Oceanic-West Huasna fault) and the San Andreas fault than within the Los Osos domain itself." Please provide additional discussion about the model as it appears to be different from other models. 141 Section 5.3, page 77, 1st "active and potentially active" Please provide criteria/definitions paragraph, 11 lines down for these terms. Section 5.3. 1, Page 78, Two alternative models are presented, but the wording is highly 1st paragraph of section, asymmetric. The first-cited references "interpret recently 142 Line 7 to 13: acquired offshore seismic reflection data to show, ... "whereas the latter-cited references "show" the contrary. Please reword to be consistent with the statement that these are alternative models. 143 Section 5.3.1, figure 5-16 "Possible Hosgri fault zone dip angles are shown on BB'." BB' should be AA'. Section 5.3. 1, page 78. "San Luis/Pismo block" is written as "San Luis-Pismo Block" in 144 2nd paragraph of section, the list of abbreviations and acronyms and in many other places Line 10: in the report. Section 5.3. 1, Page 79, 'These intersecting faults include the Los Osos, Shoreline, Paragraph 4, line 4. Casmalia and Lion's Head faults." This seems to imply that all 144 of these faults exhibit similar kinematics, but that is certainly not the case. The Casmalia and Lion's Head faults are similar to the Los Osos in that thev exhibit a laroe reverse component, but Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report their sense of lateral motion is unknown, and in section 8, the Casmalia fault is inferred to be left oblique to reverse. Please clarify the known sense of slip on these faults, as their sense of slip may control the validity of tectonic models, and whether the current transpression I shortening is the result of continued rotation of the Transverse Ranges, or some other mechanism. Section 5.3.1, Page 80, Refers to the Casmalia and Lion's Head faults as reverse to 145 paragraph 7, line 3 reverse oblique. Please indicate the sense of oblique slip, if known (LL or RL) and provide references. Section 5.3.2, page 80, "southeast" should be southwest. 146 1st paragraph, 6 line from bottom 147 Section 5.3.3, p. 81, 2"d Consider breaking up this very long paragraph. paragraph 148 Section 5.3.3 Figure 5-16 San Miguelita fault not labeled on figure. Section 5.3.3, Page 81, Provides the inferred dip of the SLB fault of -75 degrees and last paragraph of section, refers to Chs 8 and 9. It is difficult here, and elsewhere, to 149 last line confirm critical cross-referenced material without it in hand. Please provide referencing to specific sections of the report when they are available. 150 Section 5.4.1, p. 83, title Elsewhere "catalog" rather than "catalogue" is used. Please be consistent. Section 5.4.1., page 83, The terminology for the areal zones does not seem to agree 151 1st paragraph, 1st with Figure 5-20. In the latter, the innermost zone is labeled sentence: "Areal Source Zone," not "Local Source Zone." Please clarify and intended distinction. or make them consistent. Section 5.4. 1, page 83. Consider adding a short phrase (or a specific reference to 152 1st paragraph, Line 4, another section of the report) to define what is meant by "gridded seismicity rates." Section 5.4. 1, page 83. Please provide a reference to the report section where the cited 153 1st paragraph of section, sensitivity analyses are documented. last sentence: 154 Section 5.4. 1, p. 83, 1st Please specify that this is "structural" frequency (and not annual paraqraph, last sentence frequency). 155 Section 5.4. 1, page 83. If this is the first use of the acronym, please define it (it may be 2nd paraqraph of section, used freelv thereafter, as it does aooear in the acronvm table). Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report Line 2: Section 5.4. 1, page 83, It would be helpful for references to other parts of the report to 156 2nd paragraph of section. be specific as to section number. first listed item, last line: Section 5.4.2, page 84, To avoid confusion for the reader unfamiliar with the region, you 157 1st paragraph of section, might consider noting parenthetically that, while similarly last sentence: trending to the Los Osos, has an opposite dip direction. Section 5.4.2, page 84, The wording leaves the confusing initial impression that the 2nd paragraph, 1st topic of the paragraph will continue to be the San Simeon 158 sentence: Earthquake rather than the Lompoc Earthquake ("San Simeon is the sentence subject, whereas "Lompoc appears in a prepositional phrase). Please consider rewording this. Section 5.4.2, page 85, The meaning of "is considered in terms of' is not clear in this 2nd paragraph of section, context. If you mean, for example, that the available mission 159 Line 2, records (etc) place some bounds on the timing of the most recent event (as the subsequent sentence indicates), please consider usinQ some more direct wordinQ. Section 5.4.2, page 86, The phrase" ... more northwesterly compared to the more 160 1st sentence on the page northwesterly .. :*may have a typo in it. Please check and correct or clarify. Section 5.5, page 86, 3rd Please include in observation 2 a brief indication of how the San 161 line after the list: Simeon Earthquake supports the transpressional model (as you already do in the cases of observations 1, 3 and 4). 162 Section 5.5, page 86, 4th The sigma_1/d_3 could be confused for a ratio, so please line after the list restate to remove the ambiguity. Section 5.5, p. 86, znd What is the red star shown in panel (a) of the figure? Consider 163 paragraph re-sequencing the discussion here to be consistent with panels (a) then (b) of the figure. or reverse the panels in the figure. Section 5.5. Page 86.last These paragraphs describe two models on the styles of active two paragraphs on page deformation in the DCPP region, but both appear to be essentially the same in that the Hardeback transpression model shows pure shortening on the Oceanic. Los Osos, San Luis 164 Bay. Casmalia and Lion's Heads faults (in her figure), but so does the NE-SW-directed crustal shortening model of Lettis et al. (1994, 2004). How these models are distinguished is not clearly presented. Please clarify. Presumably the transoression model includes lateral slip on some or all of these Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report faults. but if so, please explain why the Los Osos fault in the OV model is RL oblique reverse, whereas the San Luis Bay, Casmalia and Lion's heads faults are believed to be LL oblique reverse to reverse. Figure 5-2 The model works until about 80 Ma, after which the slab flattened due to subduction of buoyant crust, producing the 165 Laramide Orogeny. More relevant to DCPP is the configuration that was frozen in place in the late Oligocene I early Miocene, presumably with a relatively flat subducting slab. Please provide a discussion of this configuration. 166 Figure 5-18: The orientation of the various cross-sections is not clearly explained in the fiQure or caption. 167 Figure 5-21: Legends are very difficult to read, especially in panel (b). Chapter 8 Section 8.2, page 94, 1st Please reference the section (and table or figure number if 168 paragraph. 2nd to last appropriate) where this sensitivity analysis is documented. sentence: Section 8.2, page 94, 1st Please replace "initial" with "completed" or just delete. 169 paragraph, 2 lines up from bottom Section 8.2, page 94, 3rd Please explain why the assertion here that the environment is 170 paragraph of section, 1st one of transpression doesn't contradict the approach introduced sentence: in Section 5.5 of considering both transpressional and NE-SW crustal shortening models of active deformation. Section 8.2, Page 94, Please indicate whether the transpressional strain referred to 171 paragraph 3 line 3/4 here is dextral or sinistral, and how these might change as the fault systems trend to the east and become more easterly in strike. Section 8.2. page 94. 3rd Note that this is a sentence fragment. Please rewrite. 172 paragraph of section, last 2 lines on page: Section 8.2. page 95. 2nd If this is the first occurrence of this fault name. please define its 173 to last paragraph of acronym at this point. section, Line 4 Section 8.2. page 95. last : Please note the typo: GDF means "cumulative distribution 174 paragraph of section, line function" (not "continuous"). 2 Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report 175 Section 8.2.1, Page 95 This presentation of new models would benefit from a more comolete discussion of the older models. Section 8.2.1.1, page 96, "Are judged" by whom? Please specify. If this is to be 176 3rd bulleted item: presented as a judgment by the Tl Team on the basis of the comment made about hydro-isostatic adjustment, please say so, otherwise cite reference. Section 8.2. 1.2, Page 97, The bimodal ages from Point Loma are not on the lowest Paragraph 1 terrace, they are from the 2nd emergent terrace, the Nestor terrace. Please correct. Also, the last line states that unlike 177 San Nicholas Island, Point Loma and Cayucos do not have fragments of the older -120 ka terrace at slightly higher elevation" Actually, there is a slightly higher terrace in the San Diego sequence but it is inferred to be the MIS 7 terrace (Kern and Rockwell, 1992). Section 8.2.1.2, page 97, It is difficult to follow the logic in this paragraph -is the 178 4th paragraph preferred interpretation that the 13 m terrace at Cayucos formed during MIS Se? Please clarify. 179 Section 8.2.1.2 Figure Figure is incorrectly labeled "San Nicolas Island. 8.2.1-5 180 Section 8.2.1.3, Page 98, Mentions a flight of 4-5 possible marine terraces, but lists the paragraph 1, line 1 elevations of only 4 terraces. Please clarify. Section 8.2.1.3, Page 98, Refers to a personal communication from John Caskey. The 181 paragraph 2, line 2 discussion appears to be quite speculative and need additional support. 182 Section 8.2.1.3, Page 98, "strongly developed soil" -is this documented? What are its paragraph 3, line 11 characteristics? Please provide a reference Section 8.2.1.3. Page 99. "pedimentation" is the wrong word here. Pediments form in paragraph 4, line 2 regions of vertical tectonic stability over long periods of time. In 183 this case. a flat surface can only result from marine planation of fluvial planation. neither of which would be considered pedimentation in this context. Please consider replacing "pedimentation" with "lateral fluvial erosion". Section 8.2. 1.3. Page 99. There seems to be a lot of conjecture in this paragraph, most of paragraph 4, which is not well documented except as a personal 184 communication. Please provide better documentation, explain and defend the statements in this paragraph, and include references. For instance, "it is unlikely that the Memorial Park Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report terrace surface is younger than about 400 ka" -please provide better documentation and discussion on this key age parameter, as it implies very low rates of uplift of Los Osos Valley. 185 Section 8.2.2, Page 99, Should this be equation 5. 1. There are other "equation ( 1 )" equation ( 1 ) usages in the report (c.f. page 133) 186 Section 8.2.2, Page 99, Is there a parentheses missing here? paragraph 3, line 4 Section 8.2.2, page 100, The abbreviation GDF means "cumulative distribution function" 3rd paragraph, Line 4: (not "continuous" distribution function, nor cumulative "density" 187 function). If you intend to say "cumulative distribution function" (as appears to be the case from the context), please reword appropriately. Section 8.2.2, page 100, Please be clear about how the CDFs may be combined (for 188 3rd paragraph, Line 8 example, perhaps you mean by forming a weighted sum with weights summing to 1.0?), or reference the report section where that explanation is qiven. 189 Section 8.2.2, p. 100, 5th Please replace "correct" with robust or has high confidence. paragraph, 5 lines down Section 8.2.2, p. 100, 5th If there is not a single correct (but unknown) slip rate for a given paragraph, last sentence section of a fault, then there must be some variability in slip rate along that section. Typically, the slip rate CDF would be assumed to represent epistemic uncertainty in what the "true" slip rate actually is for a particular section of fault of interest. If 190 the distribution also includes aleatory variability, as implied in this sentence, there should be a discussion of how that variability is estimated and distinguished from the epistemic uncertainty. Also. if that variability is dependent on the location along a fault. then that should be indicated and discussed as well. Section 8.3. page 101, The discussion would be easier to follow if the location of the paragraph 4, Line 4: Piedras Blancas anticlinorium were shown on Figure 8.3.1 (at a 191 minimum. some appropriate figure locating that feature should be referenced). 192 Section 8.3, Page 101, Are the seismic reflection data used to constrain slip rates or Paragraph 4, line 7 interpret them? 193 Section 8.3. 1, paqe 102, Please expand the discussion on the preferred offset, as the Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report Figure 8.3-2 figure only shows Oso terrace offset as a minimum at 150 m. Figure 8.3-3 mentions piercing points across the HFZ as the basis for preferred offset; consider labeling on Figure 8.3-2. Section 8.3.1 page 103, The discussion of Figure 8.3-3 would be easier to follow if the 194 2nd paragraph (and panels were labeled (i.e., a,b,c) and cited specifically (e.g., following paragraphs): Figure 8.3-3{a)). This comment applies to many of the composite figures in the chapter. 195 Section 8.3.1, Page 103, Traverse Range?? Do you mean Transverse Ranges, or 3rd bulleted paragraph WTR?? Section 8.3. 1 , page 103. "require reversal in uplift for the lower terraces" Please provide 196 3rd paragraph, 3rd bullet more clarification why the Muhs et al., 2012 studies on San 2 lines up Nicolas Island would require that. Section 8.3.1, page 104, The CDF curve does not plot exceedance probability, but rather 197 2nd paragraph on page, its complement. Please correct this, and check the use of the Lines 2 and 3: word "exceedance throughout the chapter, as it seems to be used repeatedly in this same erroneous sense. Section 8.3.1, Page 104, "hence broader, are not inconsistent with ... " This is a double 198 paragraph 7 (last of negative. Is it possible to make this more straight forward to section), line 2, 3 "are consistent with"? Section 8.3.2, page 105, "Cumulative density function" is incorrect. You may mean either 199 3rd paragraph. Line 3: "probability density function" or "cumulative distribution function" (probably the latter. since that is what appears in the last panel of the figure under discussion, Figure 8.3-5). Please clarify. Section 8.3.2, page 105, Please consider rewording to avoid ambiguity, since the 200 last paragraph on page, tabulated probabilities are not exceedance probabilities, but Line 2: their complements. Section 8.3.3, page 106, Figure 5-9 does not seem to show the Piedras Blancas 201 1st paragraph of section, anticlinorium. as the text implies. If it does not, please remedy line2: this inconsistency. Section 8.3.3, Page 107. Please elaborate on the implications of "the western branch of paragraph 4, last line the Hosgri is not the current locus of deformation." Does this 202 imply that this fault strand does not increase the Hosgri rate to the south? Please provide an explanation of the significance of this observation. 203 Section 8.3.4.2. Page Please rephrase this sentence as it is not clear. 109, Paragraph 4, line 7 204 Section 8.3.4.3, Paoe "at least five olacial terminations" Are vou referrino to maior Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report 110, Paragraph 4, line 4 (100 ka) glacial phases, as appears to be the case? If so, olease indicate that these are maior alacial terminations. Section 8.3.4.3, page "Paleo slope breaks associated with unconformities H10 and 111, 7th paragraph, 5 H30 occur more than 1 km west of the paleo slope break lines down associated with unconformity H40 (PG&E, 2014, Chapter 3 Figure 6-3, and Figure 8.3-6) suggesting that the lowstands 205 preceding H10 and H30 reached significantly greater depths than the lowstand preceding H40. This relationship strongly supports the preferred unconformity age model and contradicts the relationships that would be predicted by the alternative model (Figure 8.3-7). This argument is important and would benefit from additional discussion. Section 8.3.5, page 113, Could the relatively high amplitudes from the channel thalweg 206 5th paragraph, 7 lines be gas? Please consider whether gas might give rise to some of down the observed chanQes in acoustic reflectivity. Section 8.3.6, page 115, "Due to this uncertainty, the Tl team assessment of offset 207 2nd paragraph, last across the fault does not rely directly on channel Fe. How does sentence this affect overall slip rate estimates? What were the estimates from the PG&E 2014 CH3 report? 208 Section 8.3.6 page 116, Fe1 and FW1 are not shown in Figure 8.3-16 Figure 8.3-16 Section 8.3. 7, Page 116, As stated later, the slip rates to the north are expected to be Paragraph 1 higher than at DCPP, whereas the southern slip rate is 209 expected to be lower due to pulling slip I deformation off onto the Los Osos, San Luis Bay and other faults. Please discuss the implications of combining all of the rates into a single CDF. Section 8.3.7, p. 116. 1st This statement would appear to imply that the slip rate paragraph. last sentence estimates at each site are epistemic assessments of the true rate at each site, but the weights assigned to each of the sites represents the degree of belief that any given site is an indicator 210 of the rate along the fault near the plant site. This is all epistemic uncertainty. However, as stated below in the last sentence of this paragraph, the integrated distribution might also have an aleatory component in it, implying that there is true variability in the slip rate opposite the plant. Please explain if this is the case. 211 Section 8.3.7, p. 117, 2nd Does this imply that there is aleatory variability in the inteorated Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report paragraph. last sentence distribution across all sites? 212 Section 8.3.8.3, page Please note that the first column heading should be "Zeng" (not 120, Table 8-1. "Zheng"). 213 Section 8.4. 1, Figure 8.4-The CDF table may have a typo, as the first two entries give 6: different cumulative probability, but at the same slip rate. Section 8.4.1, Page 123, Refers to the "lateral slip is a good approximation of the net slip 214 paragraph 3, line 3 rate." But that hasn't been presented yet. It may be better to state that it "will be" a good ... Section 8.4. 1, page 123, It is important to determine if the terrace riser is older or 215 4th paragraph, 10 lines younger that H40 -Are there any seismic data, that would allow down the Tl team to trace H40 from the west? 216 Section 8.4.1, Page 123, The last 10 or so lines of this paragraph are somewhat paragraph 4, confusing. Could this be made clearer I simpler? Figure 8.4-5 Lower part of figure has an arrow to the right with 630 ka, which 217 refers to the possible upper end of the age range of the terrace sequence. In the text on page 124, 1st paragraph, 625 ka is stated. Please be consistent. Section 8.4.2, Page 124, Please reference Figure 8.4-2 providing the map showing 218 1st paragraph of section, location of channel I, which the subsequent discussion in this 1st line: paragraph relies upon. Section 8.4.3 Page 127, Please reference Figure 8.4-2, which provides the map showing 219 1st paragraph of section, location of channel A that the subsequent discussion in this 1st line: paragraph relies upon. Section 8.4.3, Page 127, Please explain what observation or analysis led the Tl Team's 220 3rd paragraph. second to interpretation to differ from the previous PG&E interpretation. last sentence and last sentence: Section 8.4.3, Page 128. The assumption here is that lithology and stream power are 6th paragraph. lines 9-10 similar over time. which is likely the case as these three "streams" likely originate from the same drainage source. This 221 should be made clear that they all have the same source. and that the drainage area has not likely evolved much to its present state over the expected age range of these three channels. Otherwise, the rest of the arguments in this section fail. ection 8.4.3, Page 129. Should the reference be to Figure 8.4-13? 222 2nd paragraph on page, Line 7: Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report Section 8.4.3, Page 129, Please summarize what specific observations and/or analysis 223 2nd paragraph on page, led the Tl Team's age model to differ from the previous PG&E last sentence: model. Section 8.4.3, page 129, Might want to rephrase the sentence below so it is clear that 9th paragraph, 3 lines Channel A is older than Channel C -The MIS 6 age alternative down is preferred and assigned a weight of [0.7] based on the 224 observation that Channel A is crosscut by Channels Band C, and therefore must be older than them (Figure 8.4-11) and the greater depth of incision of Channel C, suggesting it is likely a full sea-level cycle older than Channel A (as described above and illustrated in Figure 8.4-12)." Section 8.4.4.2, Page The San Luis Bay "kinematic indicators of strain (slickenlines) 131, 2nd bulleted point are compatible with reverse or reverse left oblique slip" This is 225 the first time that the possibility of left oblique slip has been raised. Is this congruent with the OV model, which implies right oblique slip on the parallel Los Osos fault? Section 8.4.4.2, Slip rate "Based on this assessment, the uplift rate of the Irish Hills 226 of SWBZ, page 132, 1st ranges from 0.15 mm/yr to 0.35 mm/yr, but most likely is paragraph 7 lines down between approximately 0.18 and 0.23 mm/yr." Please expand on why is it most likely? Section 8.4.4.2, Page The input parameters for the resolved slip calculation are in 227 133, 3nd paragraph on Figure 8.4-15 (not 8.4-16). page, Line 1: 8.4.4.2, Page 134 and This discussion seems to indicate that the vertical rate on the 135 Shoreline fault is possibly on par with the horizontal rate (up to 0.11 mm/yr vertical. with a best estimate of 0.07 mm/yr 228 horizontal). Is this consistent with other interpretations that the Shoreline fault is mostly strike-slip? (focal mechanisms, offset channels and shoreline features, vertical dip, etc.). Please clarifv the suooort for this interpretation. Section 8.4.4.2. "The second age model is called the post-LGM age model. This Constraints on Vertical model, which is assigned a weight of [0.4), accounting for the Separation Rate Offshore possibility that the wave cut platforms mapped by PG&E (2011) 229 of Irish Hills, page 135, do not represent long-lived stillstands, and may instead be 3rd paragraph, 15 lines erosional surfaces developed during the last transgression." down Please provide additional justification for this weight, given the Tl's assessment that the MIS 3 -5 age is likely to be "correct". Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report Section 8.5, page 136, Please consider referencing the section of the report where the 230 2nd paragraph of section. concept of "fault models" was defined and the NE, SW and OV 2nd to last line: cases introduced. Section 8.5. 1, page 138, Hanging wall uplift-rate PDFs (Figure 8.5-2) and footwall uplift-rate PDFs are all bounded density functions. Please explain how bounded PDFs (as opposed to discrete probability mass 231 distributions) can combine to give the discontinuous CDF's shown in Figure 8.5-6 (hint: they can't), or clarify how the CDF's in Figure 8.5-6 were actually calculated, or correct the plot (and subsequent ones) if it is erroneous. Section 8.5. 1, page 138, "The maximum value considered is -0.21 mm/yr based on the 4th paragraph, last assumption that the magnitude of hanging wall uplift (preferred sentence uplift rate of the Irish Hills) is the upper limit on footwall subsidence as predicted by various structural models (e.g., King et al., 1988; Stein et al., 1988)." 232 Please provide clarification here as hanging wall uplift causes rock to displace air -large density contrast; whereas foot wall subsidence causes crustal rocks to displaces mantle -small density contrast -it is the density contrast and associated buoyancy that controls magnitude of subsidence. Thus subsidence is larger than associated uplift for both extensional and compressional environments. Section 8.5.1, page 138, Please state the rationale that the selected fault dips adequately 233 last paragraph, 1st represent the full technically defensible range, or reference the sentence: section of the report that does so. Section 8.5. 1, page 138, Please state the technical justification for the range of rakes 234 last paragraph of section. employed. 2nd to last sentence: Section 8.5. 1, page 138, The terminology used in Figure 8.5-7 is ambiguous. What does last paragraph of section, "deviation from vertical" mean there? Unless the fault has a dip 235 2nd to last sentence: of 90 degrees, then there is no vertical reference direction within the fault plane. If you mean the complement of the rake angle, please say so (or "deviation from the up-dip direction"). Section 8.5.1, Page 138, Here, the Memorial Park terrace is potentially correlated to the 236 paragraph 6, line 14 -400 m (should read -400 ka); ... Earlier, 400 ka was suggested as a minimum age for this terrace. Which is it, and Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report what is the likelihood that it is younger, as this discussion was not verv clear earlier in the reoort. Section 8.5.2 page 138, In discussing Figures 8.5-8 through 8.5-10, please explain how 237 1st paragraph of section, the net slip rate can have a continuous CDF {implying a Line 2-3 bounded PDF), while vertical rate has a discontinuous CDF (implying a discrete probability mass distribution). Section 8.5.3, Page 139, The expression "the center of the range" is used here without 1st paragraph of section: definition. It seems to correspond to the 21st to 79th percentile 238 values in Figure 8.5.11, but similar expressions {e.g., "center of the PDF") have been used previously in the report for intervals defined differently. Please make the intended meaning clearer here. 239 Section 8.6, Page 1, 1st Note the extra ".)" at end of paragraph. paragraph, last line: Section 8.6.1, page 1, 1st Please reference the section of the report where the alternative 240 paragraph of section, last age models were evaluated and the weights cited here were line: justified. Section 8.6.1 page 1, 2nd If this statement refers back to an assessment from an earlier 241 paragraph of section, 2nd part of the report, that section should be referenced. In not, sentence: please provide a more complete statement of the technical justification here. Section 8.6.2, page 1, 1st "Deviation from vertical" is not an acceptable terminology, 242 paragraph of section, 1st because it is ambiguous (there is no vertical reference direction line. in the fault plane unless dip is 90 degrees). Please use a conventional and unambiguous terminology. Section 8.6.2, page 1, 1st Please explain why the CDF for the vertical rate appears to be 243 paragraph of section, last discontinuous (stepped) in Figures 8.6-2, 3, and 4 (which would line on page: imply a discrete probability mass function). or correct the figure. Section 8.6.2, page 2, Please state the technical justification that the selected fault 244 last paragraph of section. dips adequately represent the full technically defensible range, Line 2: or reference the section of the report that does so. Section 8.6.2, page 2, The sentence refers to a PDF for fault rake. but the range of 245 last paragraph of section, angles cited seems to apply to the complement of the rake. last sentence: Please check and make a correction if needed. Section 8.6.2, page 2, Please clarify the meaning of the "plus or minus 1 degree" in the 246 last paragraph of section, description of the distribution. last sentence: Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report Section 8.6.2, page 2, Please state the technical justification that this rake angle 247 last paragraph of section, distribution adequately represents the full technically defensible last sentence: range, or reference the section of the report that does so. Section 8.6.3, Page 2, Please indicate left or right oblique. If right oblique, please 3rd bullet explain why it is different from earlier statements that kinematic 248 data suggest left oblique to reverse. If right oblique, please explain (somewhere) how the SLB and Los Osos faults, which are nearly parallel, can have the opposite sense of oblique slip, if that is the case. Section 8. 7, page 1, 1st "San LuisPismo" is written "San Luis-Pismo" in the list of 249 paragraph, line 1: abbreviations and acronyms, and in most occurrences elsewhere in the report. 250 Section 8.7.1, Page 1, Please indicate whether the oblique slip is left or right oblique. Paragraph 2, last line Section 8.7.1, page 1, Please provide a reference to a report, or to a section (and 251 2nd paragraph, Line 1: figure) of this report, that documents the sensitivity analysis cited here. Section 8.7.2, page 2, Please check whether "Wilmar Avenue fault" should be "Oceana 252 last paragraph on page, fault" instead. Line 1: Figures in Chapter 8, The discussions of total slip and age PDFs and the associated general comment: slip-rate CDFs in the chapter would be easier to follow if the 253 multi-panel figures such as Figure 8.3-3, 8.3-5, and many others, had panel labels (i.e .. "a", "b", "c", etc), and if the individual panels were referred to by letter in the text (e.g., "Figure 8.3-3a"). 254 Figure 8.5-5: Is the location of the D-D' cross-section shown in Figure 8.5-5? 255 Figure 8.5-7: "Deviation from vertical" is ambiguous: please correct this. Figures 8.5-8, 9 & 10: "Deviation from vertical distribution" (footnote to the table on 256 right of figure) is ambiguous: please replace with standard, unambiguous terminology. Figures 8.6-2, 3, & 4: "Deviation from vertical distribution" (footnote to the table on 257 right of figure) is ambiguous: please replace with standard, unambiguous terminology. 258 Figures 8.6-2, 3, & 4: In the footnote to the table on right of each of these figures, the meaning of "1-19 degrees plus or minus 1 degree" is unclear. ATTACHMENT PPRP COMMENTS ON DCPP SSC DRAFT REPORT INSTALLMENT #2 Comment Location in Text PPRP Comment Summary of Revisions to Report Number General Comments 259 Overall, the chapters that comprise Installment #2 are well written and provide the necessary documentation for several elements of the SSC model. As noted in Installment #1, the text would benefit from a comprehensive technical edit to ensure consistency in the usage of various terms, tense, third person, etc. Such an edit would also allow for more specific internal referencing to other sections of the report. Suggested edits are provided in these comments, but they are not exhaustive. 259 As noted in the PPRP comments for Installment #1. it is strongly recommended that figure captions be developed for every figure to assist the reader in understanding the salient points of each figure. Title blocks and notes are helpful, but they often do not adequately convey the messages that the figure is intended to convey. 260 Throughout the text, the terms "SSC" and "SSC model" are used interchangeably. Common usage would dictate that the elements of the SSC model should be indicated as such, and that the activity of characterizing seismic sources should be termed SSC. Editing the text for consistent usage is recommended. CHAPTER 6-Seismic Source Characterization Overview 261 Line 14 Please check whether "piecewise planar** would better convey the intended meaning here and on Line 33. 262 Line 20 Please state, in some quantitative terms, the threshold to be considered to "contribute significantly." 263 Line 28 If this is the first usage in the report of the terms "maximum earthquake" and "floating earthquakes", please define or indicate the subsequent section of chapter 6 in which the definition will be given (they are defined on Lines 177-179. for example). Otherwise provide a reference to the previous report section where they were defined. 264 Lines 34-35 Please explain difference between seismogenic or potentially seismogenic. 265 Line 36 Please provide more detail regarding sufficiently active. Presumably this relates to recurrence rates. 266 Line 38 References to depth here. and in several other places in the chapter, are ambiguous. Please establish. in each case in which it matters, whether the reference is to depth to top, depth to bottom, or some other quantity (e.g., depth extent). 267 Lines 43-44 Please consider rephrasing to the following -Key data from the DCPP region are needed for fault slip rates and the time since the most recent earthquake 268 Line 46 Non-specific or non-specified? 269 Lines 53-55 Please cross reference where hazard sensitivity studies show that the SAF has only a small effect on hazard 270 Line 62 Please provide a more specific reference (section number and figure number(s)). 271 Line 63 "fault" should be plural 272 Line 63 Please showfreference lngley site on a figure. 273 Line 68 "Recent historical" seems redundant, especially for California as we have such a short historical record. Are you implying there are "older historical" earthquakes? 274 Lines 57-88 It is recognized that the conclusions presented in these paragraphs regarding recency, displacement per event, and recurrence intervals are summaries of the conclusions drawn elsewhere. However, the reader would benefit from specific references to the locations in the report andfor the primary references where the data have been evaluated and the conclusions and uncertainties have been developed. 275 Lines 76-79 "Selected historical ruptures that we considered in developing both Fault Geometry Models and rupture sources for these fault sources (discussed below in Sections 6.3.1 and 6.3.3, respectively) are listed in Table 6-1 " Please move parenthetical phrase to end of sentence. This occurs many places in the text and it would make the document flow better if they were at the end of the sentence where possible -see below 276 Table 6-1 One other wel I-studied earthquake to consider in this table is the 1999 Hector Mine earthquake, as it nucleated on a splay fault and then ruptured bilaterally. It also produced secondary rupture on a number of small faults. 277 Table 6-1 The source faults in the 2010 El Mayor-Cucapah rupture were not previously unidentified, as stated. These were all mapped by Barnard as part of his PhD thesis, and have been shown in a number of published sources. All were named faults prior to the earthquake. What was not known is how all of these faults work together to accommodate oblique strain. 278 Lines 104-105 Please nesh out this line of reasoning out-The founding of the mission at SLO in 1772 together with the lack of reported earthquakes in mission documents provides a rationale for settina Tmin=242 vr. 279 Line 107 "Missions were sensitive to strong ground motions" Please expand. 280 Line 118-120 Please consider rephrasing -In summary, the lack of any damage reports in documents from the San Luis Obispo mission make it unlikely an earthquake of M6.5 or larger on DCPP Primary and Connected faults since 1772. 281 Line 131 Figures 6-2 through 6-7. Consider presenting Table 7-2. Primary and Connected Fault Section Codes and Descriptions here in Chapter 6 where figures are first presented 282 Line 137 Please provide a more specific reference, i.e., number of section and figure(s), where the relevant sensitivity studies are described. 283 Line 172 Please note the typo: should be Figure 6-7 (rather than 6.7). 284 Line 174 Figure 6-7. Should a rupture source S4+S5+S6+S9+S10 be listed? 285 Line t80 This is one example of the usage of "SSC" where "SSC model" is recommended. Please ensure proper terminology throughout the text. 286 Line t85 Please remove "is" 287 Lines 204-205 "over the forward-modeling rupture model approach taken for the Diablo Canyon SSC model" Model seems to be over-used in this sentence .. 288 Line 212 Please remove "wide" 289 Line 215 Would the Hosgri fault be considered low slip rate and "within the noise?" Might want to temper this a bit by clarifying that the DCPP SSC model needs to deal with lesser faults and detailed characteristics of Hosgri fault. 290 Line 246 Consider adding a sentence noting that a forward modeling approach does not imply that there are no overall constraints in the SSC model on such things as cumulative slip rate and defo1111ation rate. Rather. it just means that those constraints are not formally imposed within the framework of an inverse modeling approach. 291 Line 248 Please change displacement to displacements. 292 Line 264 PDF is used to indicate a probability density function 293 Line 289 Please consider whether the meaning would be clearer if the passage were rewritten as "such that, when the contributions from all rupture sources that include a particular fault are summed,". 294 Lines 294-296 Are the slip rates uniform over the entire rupture source for the main fault (larger slip rate) and uniform over the entire rupture source for the secondary fault (smaller slip rate)? Please explain. 295 Line 321 Please give an indication of what magnitudes would be considered "moderate to large." 296 Lines 330-331 The last line of the paragraph is unclear as to its meaning. "the number of events captured is very few or is difficult to distinguish." The first part makes sense -the number of events is very few. The second part is unclear -"the number of events is difficult to distinguish." Distinguish from what? To count? To dete11T1ine? 297 Lines 332-338 Long sentence, please consider breaking it up. 298 Line 340 "understood to accurately model -please change to -understood to model accurately 299 Line 343-345 "but few are sufficiently large to preclude throughgoing fault rupture." Please consider adding lo end of sentence -based on observations from other segmented strike-slip fault systems (Wesnousky. 2006). 300 Line 346 Please define "behavioral." 301 Line 350 Figure 11-8 should be Figure 11-9. 302 Line 358 Please note the typo: "MDF" should be "MFD". 303 Line 361 "by maximum rupture source size** would read better as "by the maximum rupture ... " 304 Line 361-362 It is not clear how this sentence relates to the previous sentence. Does the maximum rupture source size relate to the characteristic earthquake rupture dimensions? 305 Line 363-364 Please consider expressing this differently. Do you mean that the absence of that information is not a rationale for precluding characteristic-model behavior as part of the technically defensible range of models? 306 Line 367 Please consider using a more descriptive term such as "exponential MDF" here, since another exponential distribution (i.e., for recurrence times in a Poisson process) comes into the discussion elsewhere in the report. 307 Lines 370-375 Is this saying that "faults and portions of fault networks that have been modeled with characteristic earthquakes can ALSO be modeled with exponential distributions? Or that faults and portions of fault networks that are modeled individually with characteristic earthquakes can be represented in aggregate with exponential distributions? 308 Line 379 What is an historical limit? Is this the observed maximum for the fault? For any fault of the same slip type? Please clarify. 309 Line 379 Consider replacing accidently with coincidentally. 310 Line 393 "equally durable scrutiny" Please consider replacing with -much scrutiny 311 Line 396 Please consider whether there is a published article or report that could be cited instead of the unpublished powerpoint presentation 312 Line 410-413 Please provide the justification for the sole selection of this relationship in light of these issues. For example, why is this relationship preferred in light of the "dimensions and style of faulting? the tectonic setting? The "application of magnitudes in the PSHA"? 313 Line 414 Please consider whether "end-member" is the optimal characterization of the set of proposed magnitude PDFs (Le., what distribution are they end members of? Does that distribution have four endpoints?), or whether instead the set actually includes samples from throughout the distribution of proponent models. 314 Line 420 Please delete the citation of an article that is "in preparation," or update the citation to a published article. If that manuscript is unpublished but contains elements essential to this report, please include those elements in Appendix WAACY. 315 Line 426 Please provide the rationale for the selection of these magnitude PDFs for each rupture source type. Also, please provide the justification for the branch weights cited here, or provide a reference to the report section where that justification is given. 316 Line 428 6.3.6 Time Dependency Model. Please consider moving this section up in the chapter so that the sections mirror the order of the logic tree shown in Figure 6-1: Time Dependency Model, FGM, Rupture model, Slip rate Allocation model, MDM 317 Line 435-437 Suggest clarifying that the theory relates to individual faults. PSHA began with the representation of seismic sources as zones that likely included multiple faults and, as a result, these behave more like a Poisson process. 318 Line 443 This line refers to "coefficient of variation in the long-term mean rate." That would be an epistemic uncertainty. However. please check whether that is the actual intent on this line, or whether the intended reference is to the coefficient of variation in the recurrence model (and which represents aleatory variability in recurrence time associated with a given long-term mean rate J? 319 Line 448 What is meant by a "global parameter?" 320 Line 452 "many tens of active faults". Please consider removing -tens of 321 Line 453 Please replace "to" with " do" 322 Line 456 Please give a more specific reference to the sensitivity analyses that support this statement about the hazard contribution from regional sources (i.e., by citing section number(s) and figure or table number(s) where the relevant analyses are presented). 323 Line 466 "included as a fault sources". Either drop the "a" or change sources to singular. 324 Line 466-467 Why is a conservative characterization used? How do you know that it is conservative? 325 Line 475 Please indicate who is doing the judging in this and the next sentence. 326 Line 508 Please explain what is meant by a "point source" in this context. 327 Figure 6-1 caption Please replace loger with longer. CHAPTER 7 -Fault Geometry Models 328 General Please make references to other parts of the report as specific as possible, i.e., by providing section number(s), and figure or table number(s) where appropriate. Some instances where this is required are noted in specific comments, but please review the chapter for other nstances and make appropriate changes. 329 Line 5-6 K;ommon usage would call this a seismic source characterization "model." 330 Line 10 Figures 6-2 to 6-5 are maps showing Primary and connected fault $ections not "Figures 6-5 to 6-6" as listed 331 Line 18 $uggest making reference to the logic tree that shows these alternatives Md weights. 332 Line 81 Please provide a more specific reference to the section(s) of Chapter 13 where the discussion cited here is presented. 333 Line 83-84 Please provide a more specific reference to the section(s) of Chapter 14 hat substantiate the claim made on these lines. 334 Line 96-97 r-.'ou may also want to cite the deepening of seismicity after the 1999 lzmit l:!arthquake. Seismicity deepened by -3 km, and recover over the "allowing 6 months (BenZion et al) 335 Line 107-113 Please provide references to articles or the report section(s) that present he observations and interpretation cited here. 336 Line 118 rre1111inology is odd. Suggest changing "allowed to" to "assessed to." 337 Line 131 these spatial patterns of epicenters and hypocenters? Does this 'nclude focal mechanisms and their associated geometries? 338 Plate 7-1 Plate 7-1 . Why are the names of rivers and creeks highlighted by blue IJoxes? Please remove blue boxes around names of rivers and creeks. 339 Line 164 rrhe wording on this line is ambiguous. Please rephrase this passage to whether it is the "simplified representations" or the "actual faults hat are shown in the cited figures. 340 Line 172 Please specify by whom it is considered to be insufficiently wide to be a IJarrier, and on what basis. Unclear what is meant by *'universal" in this It sounds like the Team made an assessment that the basin is not $ufficiently wide to represent a barrier to ANY future ruptures? 341 Line 174 'single fault connected fault source." The first fault" could be deleted without losing anything. 342 Table 7-2 In reference to the Wilmar Avenue fault, it would be best to spell out 'Avenue" as it is a proper name. 343 Lines 188-190 Please consider rephrasing to the following Two boundaries between fault sections that are not intersections between Primary or Connected fault sources are discussed below 344 Line 217 Please specify by whom (e.g., the Tl Team) such geometries are assessed to be the only valid ones. and consider whether the intent of this ine would be better conveyed by the phrase "technically defensible" in l>lace of "technically valid." 345 Line 218 Please explain in the caption of Figure 7 -4 the meaning of the additional Mnotations such as "<0.05 m/kyr," that appear away from the dashed curves (e.g .. are these point constraints based on specific pbservations; or are they regional generalizations, and, if so, how wide an do they apply to?). 346 Lines 242-246 Please provide a reference to the specific report section(s) where this assessment is justified. 347 Line 245 'convincing evidence of unique fault geometry". Please consider changing 'of unique" to -for well defined 348 Line 292 Please define the rake ranges that distinguish the "reverse" sense of slip *rom the "reverse oblique" sense of slip, since this distinction was not !Jiven on Lines 259-264. 349 Line 307 is required after "bathymetry data" for clarity 350 Line 308 Figure 7-5 is a good example of how figure captions would greatly help he reader interpret the panels of the figure. 351 Line 309 'DCPP that were compared to evaluate. Please consider replacing 'compared with -examined 352 Line 338 'The HFZ is the best imaged, most continuous, and complex fault zone" 'complex" -scale dependent, thus level of complexity is dependent on maging resolution -some of the faults in the Irish Hills could be equally or more complex than the HFZ?? Please clarify. 353 Lines 341-343 'Locally, strands of the fault zone exhibit seafloor expression, either as fault-line scarps, or possibly also as tectonic scarps within young Please expand to explain differences between the two. 354 Line 343 Some explanation is needed either here andlor as a figure caption what the ages of the MIS tracts and unconfonmities are in the 0igure. 355 Lines 351-352 Please explain how "aleatory uncertainty" can be captured by modeling 'alternative near-surface traces." That is, doesn't the word "alternative" mply epistemic uncertainty, and that the options for the trace location are mutually exclusive (and isn't that the thrust of the discussion on Lines 390 1404), which would preclude them acting in concert to produce aleatory 356 Line 356 Please check whether there is a peer-reviewed report or article (locumenting the study of Hardebeck cited on this line, and if there is, please cite that in preference to the unpublished Workshop 2 oresentation. 357 Line 363 Please consider replacing "apparently" to -interpreted to be 358 Line 369 K;onsider replacing "and also" with "along with" 359 Line 376 rThe seismicity is projected onto a plane that is perpendicular to the strike K>f the Hosgri fault. Also. ii is very difficult to see the plus signs and dots on he figure. Can they be enlarged? 360 Lines 379-382 Please explain the basis for the proposed associations of hypocenters to f-aults, and note any other analyses that were undertaken to try to resolve he apparent ambiguity in those associations (as seen in Figure 7-9). For can the association of hypocenters to the Hosgri fault be mproved by restricting the cross-sectional projection to events located of DCPP (avoiding interference from the northernmost part of he Shoreline Fault and Estero Bay seismicity)? 361 Line 382 to the legend, the plus symbols represent "uncertain !association." 362 Line 393 Please explain in what sense model H85 is the best fil to the seismicity. 363 Line 398 Figure 7-11 indicates "systematic offset" which could be better defined as possible systematic offset of hypocenter locations from the fault. Also, 'possible future data" is cited in the figure text but is nol discussed in the ext. 364 Lines 400-401 The H90 model fits the seismicity data, but is less consistent with fold (leformation that appears to indicate a flower structure on the reach !adjacent to the DCPP. " h°here are many fault segments offshore, could the fold deformation and 'lower structures be explained by constraining bends along a vertical fault -H90? 365 Line452 'North" Please replace with -Northwest 366 Lines 464-466 'The concept of the outward-vergent (OV) model is that uplift of the SLPB s produced by transpressional right-reverse faulting along the riortheastern and southwestern block boundaries (Figure 7-13)." Please explain/discuss. The Shoreline is a vertical strike-slip fault. Reverse slip is occurring toward the southeast on BE, WA and OF fault Such a configuration would predict uplift rates to increase oward the southeast -in contrast to the observations? 367 Line 469 Figure 7-14. Please discuss constraints on Los Osos dip from segment LE ::so') to LO (60°) 368 Lines 475-476 Uunction with dexlral-reverse Oceanic-West Huasna fault is not shown in Figure 7-13 369 Line476 Figure 7-13. Please discuss intersection of OF and SF -does lhe reverse die toward the northwest? Why is there no reverse motion along SF? 370 Line488 If the phrase seismic source zone" on this line means the same thing that 'areal source zone" or "Local Source Zone" means in Chapter 6, please the appropriate one of those previously defined te1TT1s to provide a te1TT1inology throughout the report. If is means something else, IJlease define it. 371 Line494 Please explain further the kinematics between shoreline fault and San Luis Bay fault in transect C-C' 372 Line497 Figure 7-16. Why does ancestral Shoreline Fault have a dip? Please relationship with vertical Shoreline Fault. 373 Line 497 Figure 7-16 legend states faults are solid where well located -Are Edna C land Los Osos faults well located down to -30,000 feet? 374 Line 497 Figure 7-16. Please discuss constraints on dip between the range-bounding reverse faults and steeper strike-slip faults within the range for he structural model shown in Figure 7-16 as well as uncertainties. 375 Line 508 Presumably, the sensitivity analyses only include a range of depths that !are considered to be credible. Other values could have an impact on the tiazard. Consider adding the phrase, " ... not a hazard-sensitive parameter given the range of technically-defensible depths." 376 Line 511-513 h°his sentence is confusing. Perhaps it could be broken into parts or set pff with commas. 377 Line 515 'in" is repeated -please delete one. 378 Line 530 Please place a comma between "formations" and "which" for clarity. 379 Lines 531-532 'Uplift of the continental shelf region west of the Shoreline fault as ndicated by the presence of submerged marine terraces " Please provide any age information (e.g., MIS3?) 380 Line 536 Please explain further how the kinematics in the Southwest Boundary to the northwest of segments BR and BE engender the uplift rates land patterns shown in figure 7-4. 381 Line 538 If the phrase local seismic source zone" on this line means the same hing that "areal source zone" or Local Source Zone" means in Chapter 6, please use the appropriate one of those previously defined terms to IJrovide a consistent terminology throughout the report. If is means somethina else olease define it. 382 Line 540-541 Please discuss the constraints on the Wilmar Avenue fault being rooted nto the steeper Los Osos East (LE) fault. 383 Lines 542-543 How well are the fault intersections at depth known? Is it important to GMC? Please provide any insights possible. 384 Line 543 IA comma between "fault" and "assuming" would make this line clearer. 385 Line 567 Please check the caption of Figure 7 -17a. On the third line of the caption. "sinestral transpression" be changed to "sinistral transtension"? !Also please mention in the caption of Figure 7 -t 7b the reference number the transpressional reverse splay feature that is noted there. 386 Line 568 Figure 7-18. Southward dipping fault that intersects the Shoreline Fault at klepth is Dashed in Figure 7-18 and solid in Figure 7 -16 Please make 387 Lines 622-623 Why does the SLB faull increase to so* on cross section D -D'? Any t;onstraints? 388 Lines 641-642 The Los Osos East fault (LE) is characterized as an axial surface that (lips steeply to the southwest. " In panel B-B'. the Los Osos axial surface is not controlled by the change n dip of the controlling detachment and intersection of the San Luis Bay *ault -please explain location and driver of the "zone of defo1TT1ation" for he Los Osos axial surface. 389 Line 642 rrhe lelTTlinology "fold hinge" is used in the figure, but "axial surface" is used in the text. Please clarify. 390 Line 657 rThis would read more clearly as "San Luis Bay, Wilmar Avenue and Pceano faults). There is also an extra comma at the end. but inside the l'.larentheses 391 Line 668 $hould this be "fold" axis? 392 Line 682 $hould "OV" model be SW model? 393 Line 684-689 rrhis sentence is too long and could be improved for clarity. 394 Lines 729-734 Please move lines 773 -776 right after 734 so the reader knows why the kJips of the faults are different for the Edna block in A-A' in Figure 7-22 and Figure 7-26. 395 Line 747 Do you mean resolution? Regional constraints? Please K;larify. 396 Line 752 'The dip of the Los Osos fault is shown as 500 throughout the entire crust beneath the Irish Hills." It is shown as 60" in profile B-B' in Figure 7-26. 397 Line 780-781 Sierra Pampeanas is the Spanish spelling, Pampean Ranges is the English spelling -you have mixed the two. Please choose one. 398 Line 797-802 rThis statement is not germane to DCPP and is an incorrect interpretation. rrhey based this on a leveling line at the south end of the range where opography is actually low. and then apply the 1977 observed deformation o the highest part of the range. This results in a shortening rate that is an prder of magnitude higher than actually exists. It would be preferable to k.lelete this sentence as it adds nothing. 399 Line 824 rThis 1st sentence would read better if a couple words were added: '. .. subsequently been reactivated in the contemporary tectonic setting as transpressional system." 400 Lines 834-837 Uplift patterns in the SW portion of the Irish Hills (Figure 7 -4) northwest of $egments BR and BE (Figure 7-13) are difficult to explain in the OV model >-please expand the section to clarify the uplift boundary. 401 Figure 7-20 rThe massif names are lh Bogd and Baga Bogd (Big Bogd and Little Bogd). This spelling is different than in the text (see line 584). which uses he correct spelling. Please correct this figure to be consistent with the ext. CHAPTER 11 -Time Dependency Model 402 General Please review the chapter for notational consistency with Appendix. T1 for he forecast interval seems to be the same thing as To in Appendix. for 403 Line 8 rrhe first line is fuzzy in its meaning. Please improve the wording to mean what you are trying to say: "Recurrence models can be divided 'nto two categories, those that are time independent and those that are ime dependent. 404 Line 10 What has been described is not a Poisson distribution (which would the probability of n events occurring in a given time interval), but ather a Poisson process. Please use the more precise statement. 405 Line 12 Please consider adding a definition of the hazard function. or referring to Eq. 7 of the appendix for the definition. 406 Line 13 rrhis section discusses how time dependent models are considered but 11ot why. As noted, time independent models are typically used for site-PSHA purposes. Why is a time-dependent model being t;onsidered? Please provide additional discussion of the need for the of a time dependent model for faults and why the use of an Poisson rate is used, rather than a time-dependent PSHA. 407 Line 14 rrhis would be clearer if "models" was inserted after "most common" 408 Lines 20-21 rrhe statement "time-dependent recurrence distributions are more t;omplicated than the Poisson, implies that "Poisson" means "Poisson which does not make sense. If the intention is to compare the ime-dependent recurrence distributions with the exponential recurrence (which characterizes the Poisson process), please make that 409 Line 24 Might add something like. "particularly if there are other compelling easons for considering ii." If there was no physical basis for a time-model and no data upon which to base it. there would be no ustification for its use. 410 Line 25 rrhe phrase time-dependent fault recurrence" is incorrect. The ticcurrence of earthquakes can be time-dependent but faults don't recur pver time. Suggest removing "fault" or changing fault to "earthquake" 411 Line 26 'The SSC recognizes ... " The SSC is now sentient? Do you mean the "Tl h"eam recognizes ... "? Please clarify what you mean here. 412 Line 29 r-.'ou included time dependent recurrence or recurrence models? 413 Line 35 Might be useful to say that this is done via seismic moment rate to for rupture geometries. 414 Lines 38-39 h"he way it is described, the EPR appears to be a dimensionless ratio ("a that can be applied to the earthquake rate"). If this is a correct µnderstanding, please reconsider whether "Equivalent Poisson Rate" is an term, since the description in the text implies that it is not a ate at all, but a ratio of rates to be applied as a correction factor. If this is not a correct understanding, please make the actual definition of EPR 415 Line 42 Unlike other chapters. this chapter is written in the first person. Suggest µsing third person throughout the report. 416 Lines 42-43 'we review these data, and ranges of possible values where specific data 1>re not available." What does this mean -it is unclear what these data efer to when specific data are not available. Please clarify what you are ta. 417 Lines 48-49 Here it is staled that there are no data whereas earlier in the paragraph it s stated "limited data". Please clarify the intended meaning. 418 Line 55 Is there a hyphen missing in "site-to-source? 419 Line 57 'available data available" -extra word here? 420 Line 58 'slips per event" -do you mean "slip per event data"? Please clarify. Also riote that displacement per event" is used in other places in this chapter land in Appendix EPR. If the meaning is the same, please consider to maintain consistency of terminology. 421 Line 62-63 'A trench at the lngley site shows activity in the late Pleistocene" but then here is discussion of deformation (warping) in the past 2500 years and 1840 year-old deposits are faulted. These statements are incongruent. Please clarify. 422 Line 73-76 rThis is a summary of the interpretations and there needs to be better eferencing of the primary sources and/or sections of the report where the nterpretations were developed. 423 Line 75 Please check whether "displacements should be "displacements per and make any necessary correction. 424 Line 79 rThis last sentence could be improved for clarity of intended meaning 425 Line 83-84 'recurrence intervals between 265 and 2000 years, " sounds like there are multiple sites with abundant paleoseismic data. Do you really mean the on the recurrence interval falls in the range of 265-2000 yrs? 426 Line 89 'sample only the most recent few events" -do you really have the past *ew (i.e .* more than 2) earthquakes dated on the San Simeon fault and Los Osos faults? Please verify this statement. 427 Line 89 Not clear what "both" refers lo here. since there were multiple trenching along the Los Osos fault. Likewise. what are the "sites" are that are eferred to below in line 91 428 Lines 97-100 Is there a reason for specifying data types that currently don't exist? It the technical basis for the conclusions drawn 429 Line 99 'none of this sort" -are you referring to "this sort of data"? Please clarify 430 Line 108-112 rThese statements about the effects of early historical earthquakes are fine but they need context. Your basic argument is that there are early of significant magnitude that damaged some of the Spanish missions at significant distances. You need a concluding statement that $ummarizes this so that when you segue into the absence of such at the San Luis Obispo mission. it strikes home the argument that here have been no moderately large to large earthquakes affecting the egion since 1772. Also. note that the location of the 2nd large 1812 l:!arthquake (Dec. 22nd) is debated -Toppozada et al. (1981) place this the SAF but this is a hotly debated topic among those working on the and its affects (i.e. tsunami. which has been found in no direct and solid evidence found yet in paleoseismic at Frazier Mountain, although they pushed hard to make a t;ase, at first) 431 Line 120 Suggest adding "occurred" after larger. 432 Line 126 By saying that "it is likely that the local completeness level is actually ower, it sounds like less complete but you likely mean more complete. Please clarify. 433 Lines 127-129 What is the reason for the different weights? 434 Line 138 Please correct "cumulative density function" to read "cumulative function. 435 Lines 139-141 It is not clear that 0 is singular or plural, or what 0 actually signifies. This more explanation, and a good definition of E+. 436 Line 177 rThe correct statement is that the variate assumes only non-negative i.e., its support is the non-negative real line (the current wording mplies only that the distribution itself is non-negative, which is true but not nformative). 437 Line 185 Remove "is" 438 Line 186 Do you mean to say it doesn't depend on p as a mean parameter, or that 't doesn't depend on the mean of parameter f* '! 439 Line 192 In reference to the phrase "less than what Poisson rate, please specify hat the comparison is with the Poisson process that has the same long-erm mean recurrence rate that the given lognormal model has. if that is he intended meanina. 440 Line 193 Not sure what is meant by "anticipates". Please explain or choose a better word. 441 Line 194-195 'we do not know the times of the most recent events for any ... " Earlier, tyou laid out the paleoseismic data and discussed recency of faulting on he Los Osos fault (1840 rcYBP. line 72). and you discuss recurrence ntervals on the San Simeon fault (lines 84-85), which imply some nformation on past earthquake timing. Perhaps this lack of data needs lo be better explained earlier. and better summarized as it leaves the reader K;onfused as to what we know and what we don't know. 442 Line 196 If tMRE is treated as a random variable please state that explicitly. 443 Line 197 'The choice of functional form in time dependence is also unknown " As $lated, you are saying the "choice" is unknown. Please restate. 444 Line 211 'Coincides with the data estimale" is vague as lo whether the aperiodicity 's or is not the CV. If ii is the CV. please say so explicitly, if it is not, please what it means that it "coincides with the data estimate" of the CV yet is not the CV and why this distinction needs lo be made. 445 Line 212 Remove "wide" 446 Line 228 Please justify why the 3 time-dependent distributions plus the exponential are a reasonable representation of the center. body and range pf recurrence models. 447 Line 259 Please provide the technical justification for the DPE distribution in Figure 11-3, or provide a specific reference(s) (chapter or appendix. and $ubsection number) to the part of the report where the justification is kliscussed. 448 Line 260 Please state brieHy what is meanl by "faull distribution point" and give a reference to the sub-section of Chapter 8 where ii is defined ::however, a search of chapter 8 returns no match for "fault distribution point"). Allematively, if the meaning is just the 8.5, 50, and 91.5 IJercentiles from the CDF for Hosgri slip rate, please say so explicitly. In event, if there is to be a reference to Chapter 8 it should be made as to subsection (and perhaps figure number). 449 Line 271 It appears that the correct joint probability is that of L TM and tMRE. not L TM and S(tll TM) (in fact, the latter is a distribution. isn't it. not a random And joint probability of (l TM,tMRE) would be consistent with Figure 11-5. Please review and correct the text if necessary. 450 Line 272 Please provide further explanation of Figure 11-5. Are these plots to be 'nterpreted as joint probability density plots? If so. why does the area k.mder the function obviously exceed 1? Is each such joint probability ktensity function (if that is the correct interpretation) specific to a particular value? Some (not all) of this is cleared up after study of the !appendix material, but the explanation in this chapter needs to be self-K;ontained enough to be comprehensible without familiarity with the !appendix. 451 Line 274 Same comment as for Figure 8 of appendix: The horizontal axis in Figure labeled "Equivalenl Poisson Rate" (and EPR is indicated in the K;aption ). but the text seems lo indicate that this axis represents the andom variable CPR, not the estimated value EPR, and this nterpretation is reinforced by the fact that the plot is presumably showing he CDF of a random variable (i.e., CPR). Please review and modify as necessary to make the text and Figure 5 consistent, and to make clear lany conceptual distinction between CPR and EPR 452 Line 279 Please clarify the meaning of the phrase "relative to a Gaussian !approximation" in this context The Miller and Rice method minimizes misfits to the low-order moments by applying the moment-preserving IJroperties of Gaussian quadrature. In what sense can this be thought of las minimizing "relative to a Gaussian approximation"? 453 Line 286 Please provide discussion and/or references (to external documents or to eport section(s)) justifying thal the proposed CV weighting adequately epresents the center, body and range of lechnically defensible

• nteroretations. 454 Line 323 h'he verb "is" refers back to differences, which is plural. Please change to 'are" 455 Line 333 Please clarify the meaning of "less coherent as a source of hazard." 456 Line 336 $charer et al. (2014) does not appear in the list of references. 457 Line 347 Please review the appropriateness of the term "marginal distribution" in his context (and consider whether it makes sense to refer to a marginal opposed to a conditional distribution-as being 'conditioned on" a value of one of the variates). The text does not make that any variate has been marginalized, but rather seems to imply hat the initial joint PDF has been defined as delta(tMRE-To) x p(LTM). If he term "marginal distribution** is actually the correct one, please explain why .. 458 Line 349 rThe correct figure reference for displacement per event models appears to be 11-9 (not 11-8). Please check this. 459 Line 349 Please indicate (in both the text and figure caption) which recurrence model (lognormal, BPT. Weibull) is used in the construction of the results n Figure 11-9. 460 Line 351 $houldn't observation be plural? 461 Line 360-363 rThe explanation of the averaging is ambiguous and can only be worked tiut through reverse engineering from Table 11-3. Please rewrite to make t clear whether: ( 1) only SAF 1 is used in the final averaging; (2) a mean is taken for each of the three selected percentile points; Md (3) those means are weighted by 0.25, 0.5 and 0.25, for the 8.5, 50, 91.5 percentile cases, respectively, to form a final weighted mean EPR. 462 Line 362 Please give the rationale for the 0.25. 0.5, 0.25 weighting (referring to Miller and Rice if that is appropriate). 463 Lines 368-371 Please explain how the conditions (other than degree of hazard described here apply differently to the non-SAF regional faults han they do to the Primary (Hosgri. Los Osos, Shoreline, and San Luis Bay) faults. If there is no difference, justify why it is technically acceptable o not use an EPR for the regional faults even though it was found to be echnically required to do so for the Primary faults. If the sole justification s absence of hazard sensitivity, please review this passage and consider whether it could be better focused on the one relevant issue. 464 Line 371 Please provide reference(s) to studies that demonstrate the absence of tiazard sensitivity cited here. 465 Lines 384 Please clarify the sense in which the San Simeon event is less mechanically related to the Primary faults than the Landers rupture is to he Hector Mine faults. 466 Lines 396-399 Please indicate whether the Tl Team judges that the EPR model captures epistemic uncertainty to accommodate the absence of a reliable model for how large events influence the likelihood of subsequent events If so, provide the justification for that judgment. If not. please explain where that uncertainty is captured in the SSC model. 467 Line 403 IA comma is required between "'Farther afield" and '"EPRs" for clarity.

468 Line408 Please explain precisely (either here or in the paragraph beginning on Line 436) how the final values of EPR for the Hosgri and SLPB cases in Table 11-4 were obtained from the various estimates in Tables 11-1 and 11-2 (the corresponding calculation for SAF was explained in $ection 11.2.6). There is some explanation in the paragraph beginning on Line 436, but it is neither complete nor precise enough to enable the steps o be reproduced. 469 Line 427-429 rrhe in1ended meaning of this sen1ence is not clear. Please clarify. 470 Lines 430-432 rThere should be some recognition of what this approach means in terms pf the alternatives that are included in the values that comprise the tables. For example, what does this imply about relative defensibility of the ecurrence model functional forms? 471 Line 432-435 Please explain in what respect the range accounts for the fact that the EPR may not fully characterize all contributory factors. The range in the ables is wider than the range of the three branches. Isn't the range directly by discretizing the CDF obtained from the EPR analysis? 472 Line 438 Please clarify the meaning of "rounded across fault slip rate cases. 473 Line 455 Please clarify if 1his is seismic hazard. If so, the influence on hazard of any fault is a function not only of the effec1ive (EPR-adjusted) slip rate, noted, but the distance of the fault from the site. So large changes in he EPR for distant faults will result in small changes in the hazard. 474 Figure 11-3 rThe bottom panel has the same title as the upper panel, even though it is distribution of times, not displacements. Please correct title. 475 Figure 11-3 rThe box title and in the figure headers indicate displacement per event, l>ul in lhe text, you refer lo these as average displacement. Please clarify 'f these should be indicated as "average" displacements, both in the figure headers and box title. CHAPTER 12 -Regional Fault Sources 476 Lines 6-8 'Faults capable of producing moderate to large earthquakes that are not ncluded as Regional fault sources are represented by the areal source (Chapter 13)." Please move to end of paragraph after line 13. 477 Line 13 In place of (or in addition lo) the word small," please provide a statement of the relative hazard contribution from the regional *aults. 478 Lines 28-29 $ounds like a sales pitch rather than an accurate technical statement If he study is "comprehensive" why does it omit many faults? What is meant IJY "objective?" How can something be consistent with "all available data" when misfits are allowed to occur? Suggest toning down the description of UCERF3 to be more realistic and to specify that it provides a reasonable l>asis for characterizing some of the regional faults for the SSC model. 479 Line 34 Please consider citing an authoritative source such as a USGS report in $upport of the statement on this line 480 Line 35 rrexl moves back and forth belween first person and third person. Suggesl using lhird person throughout 481 Line 35 and 37 !Adapting (which implies changing them) or adopting (which does not imply 482 Line 39 rrhe quotation marks suggest that this is a quotation from some source. or hat the word itself. rather than its ordinary meaning, is the object of nterest. Please consider whether either of these is the case and edit (or riot) accordingly. 483 Line 58 Please specify that this is an assessment made by the Tl Team. 484 Lines 59-60 rrhe first clause of this sentence appears to have some sort of ranscription error. Please review and correct it. 485 Line 68 Where does this logic tree exist and who assigned the equal weights? 486 Line 72 'Figure 12-5 shows ruptures common to both" Is the top panel of Figure 12-5 intended to include faults common to both UCERF3.1 and 3.2 models? Presently, it is labeled Fault Model 3.1. 487 Line 85 'the depiction in this SSC model, while FM3.1 does not." Please consider deleling "depiclion in this" 488 Line 95 Suggest deleling "radial." 489 Line 113 'come nearer closer to the DCPP than the physical SAF itself." Please consider rephrasing to -come closer to the DCPP than the SAF. 490 Line 117 Please replace "we" with Tl team, if appropriate. 491 Line 216 Figure 12-4 indicates "Queenie fault". Is there a difference? 492 Line 244 !Are you suggesting juxtaposition of units of similar age that have different thicknesses? Please clarify. Otherwise, this could be 'nterpreled as growth slrata. 493 Lines 252-253 'Sorlien et al. (1999) note that the large amount of strike-slip inferred is j)ased on a regional tectonic model, and they discount the large offset. " Do Sorlien et al. (1999) provide an estimate of slip? 494 Line 262 Please consider changing "overlapped" by onlapped or draped 495 Line 290 What is the type of magnitude indicating 7.0? Ms? 496 Lines 301-302 It is understood that the characterization is simplified (i.e., single-valued). However. there is insufficient info1TT1ation in this section to understand how he values in Table 12-5 are derived. For example, the estimated slip rate wor the Queenie structure is said to be 0.005 mmfyr in section 12.6.1.2, but 0.1 mmfyr is shown in the table. The slip rates for the Santa Lucia Bank land West Basin -Southwest Channel faults are listed here at 1 mmfyr. Earlier, you cite a rate of 0.2 mmfyr since the Pliocene for the WB_SC *ault, which is likely a maximum as you state that much occurred toward he end of the early Pliocene. Slip rates for other faults shown in the table iare not discussed at all in the text. What approach was used? In the !absence of fault-specific info1TT1ation, drawing analogies to other faults is !appropriate, but must be indicated as such in the text. Likewise, what was he approach used to assess Mchar? It is not sufficient to merely indicate hat sensitivity analyses show these faults aren't important; that is dependent on the characteristics that are ascribed to the waults. If one of the faults had a slip rate of 30 mmfyr, the hazard $ignificance might be different. 497 Figure 12-3 Consider a way to name the fault sources -not everyone will be familiar with the California fault system. 498 Figure 12-7 Whal produces the sloping linear trends in seismicity rate between M6.5 land M7.5. These are interesting and should be explained in a caption ::which needs to be added to this and other figures). APPENDIX-Method For Estimating Time Dependent Fault Hazard in the Absence of an Earthquake Recurrence Record 499 Line 45 "Poisson probability distribution of ground rupturing earthquakes" is !ambiguous. Distribution of what? And, in fact, the Poisson distribution 'tself (probability of exactly n occurrences in a given time interval, as a *unction of n) is never used in the report. Please consider changing to a more precise statement (e.g., "the model of ground rupturing earthquakes las a Poisson process assumes that events occur randomly in time"). 500 Line 47 rrhis would be clearer if "to occur" is inserted between "more likely" and 'when the energy" 501 Lines 58-60 PSHA also initially did not consider the faults that gave rise to all seismic sources were source zones. each of which likely ncluded several faults. The point should be made early in this section that he whole time-dependent recurrence concept is for fault-specific ecurrence behavior. 502 Line 66 rrhe word "be" seems to be missing between "cannot" and "rigorously". 503 Lines 67-68 Consider indicating that an additional reason for the use of the Poisson model is that regulatory design criteria are expressed as target annual of exceedance (e.g., 10-4) without consideration of any lime klependence. 504 Lines 70-71 But, as you discuss below. the use of an equivalent Poisson rate does NOT require a change in the hazard code, just inclusion of the concept in he SSC model. Please clarify. 505 Line 97 'Cumulative density function is incorrect; please rewrite as "cumulative k!istribution function." 506 Line 162 rThe phrase "before reaching the long-term mean could be misinterpreled o mean that the CP ratio is asymptotic to the long-lem mean. which isn't the case. Please consider rephrasing to avoid ambiguity on this ooint. 507 Lines 166-167 you saying that we have absolutely no idea whal the value of these varameters might be? Or that we have no direct data upon which to base hem, but they can be estimated with considerable uncertainty? 508 Line 180 rThe phrase "although it coincides numerically with the data estimate of the more familiar coefficient of variation" seems unnecessarily cryptic. Since, nits role as a parameter in a PDF (Eqn 10). alpha is equal numerically to he CV, please clarify why it cannot simply be said to be the CV. 509 Lines 205-206 rThis statement is not always true for faults having good paleoseismic klata. Please qualify that this information is assumed to not be known for he faults in this exercise. 510 Line 210-211 The distribution conveys a relative agnosticism among choices in (lisplacement per event (DPE) from 1.5 meter to 3.5" Figure EPR-3 shows DPE from 1.5 -3. 511 Line 213 Up to 5.0 m in the text of the report (line 258, page 14 of chapter 11 ). Please check and rectify if different. 512 Lines 214-216 Please consider changing to the following (less fragmented) -In California, for example. the largest measured average slips per event K>n the San Andreas fault are 4.45 and 4.3 mlevent for the 1857 and 1906 respectively (Biasi et al., 2013). 513 Lines 218-22 rThe reference to an upper bound of 5 m/event in the text appears to with values up to 5.5 m/event given by the solid curve in Figure 3 ::there is a break in slope at 5.5 m in the plot, indicating a non-zero l'.lrobability point at that value of slip/event). Likewise. reference to an bound of 4 m/event in the text appears to conflict with values up to m/event for the dashed curve in the plot. Please check and make any required for consistency. 514 Line 227 If L TM is displacement per event divided by fault slip rate. then L TM must J:>e an inverse rupture rate (or mean recurrence time), not a rupture rate as Please check the text for consistency and correct as necessary. 515 Line 247 Please replace "to" with "do" 516 Line 265 If the reference to Philibosian et al is the same article listed in the eferences section, then it should be cited as 2011 (rather than 2012). Please check and make a correction if necessary. 517 Line 268 Since 1he EPR is a dimensionless ratio, not a rate, it would be clearer and ess subjecl to confusion to call it something else. Later the EPR is from the distribution of "conditional probability ratio (CPR)". erminology that explicitly indicates the dimensionless character. so calling EPR a rate and CPR a ratio is a source of confusion Please consider this point. 518 Line 275 Please replace "complimentary with "complementary." 519 Line 283 is needed after "renewal to set off the first part of this sentence. 520 Line 284 rrhe "IL TM" appears to be a typo-please check whether this should be 'LTM". 521 Line 286 It will cause confusion to say that the CPR is elevated relative to the Poisson rate, because the former is a dimensionless ratio and the later is an absolute rate (events/unit time). Please rephrase this to be more precise 522 Line 286 rrhe distinction between CPR and EPR is never stated explicitly, and this confusion later on. The eventual impression is that CPR is treated as a random variable and EPR its estimated value; if so, please consider making this explicit, and if not, please add text to clarify the mathematical/conceptual distinction between them. 523 Line 288 rrhe phrase declines to approach the Poisson rate at the upper probable ange of tMRE" may be misleading. First of all, since EPR is a ratio, $houldn't it approach unity if the CP approaches the Poisson probability? If so, please rephrase to make that clear. Secondly, the phrasing can be nterpreted to imply that the approach to the Poisson rate is an asymptotic l>ehavior. As that is in general not the case, please rewrite to avoid that *mpression. 524 Line 297 rrhe peak appears to occur below the diagonal in Figure 6, not above the kliagonal as stated. Please add clarification or correct the statement or Figure as necessary. 525 Line 303 rrhe term "joint probability surface" appears lo be used here lo denote a 'oint probability density. However. this is not made explicit, and doubt is aised by Figure 7. in which it is obvious that the integral under the surface s much greater than 1, ruling out its interpretation as a joint PDF. Further arises from Equation 13, as discussed in a subsequent K;omment. Please be explicit and precise about what is meant by "joint 1>robability surface." 526 Line 303 rrhe joint probability appears to depend upon slip rate If that is a correct nterpretation, please indicate (in the text and caption) what slip rate was to generate the probability function in Figure 7, and confirm that that rate plus the Hosgri OPE model of Figure 3 was the basis for the marginal distribution p(L TM) used to generate that figure (or if, that is *ncorrect, give the correct explanation). If the joint probability does not upon slip rate, please improve the description to make clear why riot. 527 Line 308 rrhe survivor function S(tMREIL TM) integrated over tMRE (for fixed L TM) snot generally unity. p(L TM), being a PDF, does integrate to unity. So W ntegrated over the tMRE,L TM plane is not generally unity. Therefore Wis not a joint probability density. yet the text gives the impression that it is 'ntended to be just that (though that interpretation is also cast in doubt by Figure 7, as noted in a previous comment). lfW is something other than a oint PDF, please explain clearly what it is. If W is a joint PDF, but the easoning in this comment to the contrary is incorrect, please clarify in the ext why there is no contradiction. Otherwise make necessary corrections that W can be properly considered to be a joint PDF. 528 Lines 313-15 rThis sentence seems correct, but ii is confusing because its intended l'.lurpose is unclear. Is it simply intended lo point oul that the variates IMRE and L TM are not independent (because the factor S in Eqn 13 depends not just on tMRE, but also on L TM). so that (by definition) the joint PDF is not simply the product of the marginal PDFs? Please rewrite or amplify to the intended meaning. 529 Line 320-32 t rThe horizonal axis in Figure 8 is labeled "Equivalent Poisson Rate" (and EPR is indicated in the caption). but the text seems to indicate that this axis represents lhe random variable CPR, nol the estimated value EPR, Md lhis interpretation is reinforced by lhe facl that the plot is presumably the CDF of a random variable (i.e., CPR). Please review and modify as necessary to make the text and Figure 8 consistent, and to make clear the conceptual distinction between CPR and EPR. The same K;omment applies to Figure 9. 530 Line 320-321 Since apparently the curve in Figure 8 is a CDF (or the complement of pne), its maximum value should be 1. This is not clear in Figure 8. If in fac he curve does rise rapidly to inlersect 1 al zero CPR (and from looking at Figure 9 ii becomes clear that it does), to avoid any confusion, please ndicate that fact with a modification to the figure or a note in the caption. 531 Line 335-336 Please explain the meaning of the vertical dashed lines in Figure 9. 532 Line 343 Please review the use of the term "marginal distribution" here. Wouldn't marginalizing on tMRE mean integrating over it, whereas what is l'.lroposed is concenlrating lhe tMRE dependence in a delta function to begin with. so W=p(LTM) x delta(tMRE-t_eqk)? In What sense is it lrue that "the equality constrain! is a form of marginal 533 Line 396 It is a little recursive to say that values of parameters used for Figure 12 were fixed to the values used in Figures 9-12. Please consider revising his. 534 Line407 Figure 13 has not been cited prior to this citation of Figure 14. Please whether the figure currently labeled 13 should be deleted and currently labeled 14 and 15 should be relabeled 13 and 14. If so, hen the citation at this point in the text should be Figure 13 (and figure citations are already correct). 535 Line426 would be useful between "principle" and "slip rale. 536 Line 456-457 Please explain the connection between the weighting method mplemented here and a maximum likelihood perspective. 537 Line 466-467 Please provide references for the cited MFD functional forms. 538 Figure 5 Please correct the following deficiencies in the figure: 1. The caption is inadequate. It should provide additional info1TT1ation, ncluding at least the CV used to generate the plots, the meaning of the circles in the upper right panel, and the meaning of the curve cutoffs n the lower panels. It should also properly indicate the nature of the are not all lognormal distributions. as the caption would even though they are all quantities derived from lognormal panels are called out by letter (e.g., Figure 5d) in the text, but hey are not labeled with those letters. 539 Figure 7 Please indicate in the caption what slip rate was used to generate this what DPE model was used ( Hosgri DPE model of Figure 3?), land what CV was assumed. 540 Figure 8 Please indicate in the caption the meaning of the red stars. 541 Figure 9 Please define the symbols, either in the legend or the caption or both, as well as stating the meaning of the vertical dashed lines (which do not to be mentioned in the text either). Please also improve the figure itle, which is rather cryptic (what does "Four Tmin,LN", mean, for Also please review the use of EPR for the title and horizontal !axis. and make changes as necessary to ensure consistency with the in the text and with any intended distinction between EPR and K;PR. 542 Figure 10 Please write a more complete caption for this figure. Is it based on the Hosgri DPE model? What are the dotted lines in the upper panel? Tmin is given in the legend, but not clearly identified there, so it also should brobably be given in the caption. 543 Figure 12 Please improve the caption. At the least, the meaning of the colors should Ile explained. 544 Figure 13 rThis figure may be redundant. Please check whether that is the case and if appropriate. 545 Figure 14 Please check whether this figure should be relabeled "Figure 13". 546 Figure 15 Please check whether this figure should be relabeled "Figure 14" and write a more informative caption (which should include deciphering "BWM"). Comment Location in Text Number 547 Line 5 548 Line 6 549 Line 8 550 Line 13 551 Lines 28-30 552 Line 37 553 Lines45-46 554 Line 49 555 Lines 57-58 556 Line 62-63 557 Lines 65-68 PPRP Comment Response Table Installment #3 PPRP Comment CHAPTER 9-Rupture Models "Historical ruptures have involved ..... Some historical ruptures? Many historical ruptures? Please clarify. "single fault zone" is referenced to the 1992 Landers earthquake, which actually involved 5 separate faults. Please clarify or correct. Using a colon after "styles of faulting" is change in style from earlier in the paragraph where the earthquake was in parentheses. Please make consistent for clarity of reading. "define fault rupture lengths" Do you mean to define potential rupture lengths? Define the potential for future rupture lengths? Define future potential ruoture lenoths? Please clarifv. Please state more explicitly the technical rationale for the choice to treat the rupture sources as aleatory variability. How is it different from a recurrence curve that expresses the aleatory variability in the magnitudes (and rupture dimensions) of possible earthquakes that occur on a fault source? Additional explanation is needed to understand the concept, the technical basis, and the implications to the SSC model. Also, there is an implication that epistemic uncertainties have not been included. It is recommended that the manner in which epistemic uncertainties were captured be identified here in juxtaposition with the statement that epistemic uncertainties are not included in the modeling of rupture sources. Plate 9-1. Please explain why the surface projection of dipping rupture source changes along strike for 75' dip, but appears more constant for 85' There is epistemic uncertainty regarding the slip rates. but how is slip rate itself treated as epistemic uncertainty. Please clarify your meaning. "A demonstration" or "demonstrations" ?? The fault names should all be followed by fault for clarity (Le .. Hosgri fault, Shoreline fault, etc.) Please clarify that the historical examples from Chapter 7 were possible analogues for each FGM, taken from other regions. Both here and Line 231, the declaration is made, without much technical basis. that the suite of rupture sources "captures the range of viable ruptures." How is this consistent with the SSHAC imperative to capture the CBR of the TDI? What is the basis for judging that the range is captured, especially since the approach of identifying specific rupture sources is different from the classic approach of defining recurrence curves for each fault source? It is noted that the range is considered adequate to capture the sources that contribute significantly to the hazard. Were there hazard sensitivity analyses conducted to support this Summary of Revisions to Report assertion? 558 Line 81 The descriptions of the respective rupture source types in Figure 9-1 differ significantly from the definitions given in Table 9-2. If the figure and table are intended to convey different types of information, please make that clear in the text and figure caption. In any event, please make sure that it is clear which characteristics are the defining characteristics of the rupture source types. and which just represent typical examples. 559 Line 84 Explain what defines the length of a characteristic rupture as being <100 km. There are many worldwide examples of longer "characteristic' ruptures. Are you saying the Hosgri fault only produces characteristic ruptures that are less than 100 km in length (-M7.2). Clearly later in the report, this is not the case. There needs to be some explanation as to why you broke out characteristic behavior to be limited to relatively short rupture seQments. 560 Line 96 Please replace comma with a semicolon after GMC model, 561 Line 105 Please consider some alternative way to describe "splay" rupture source type, because "overlapping source planes" is ambiguous (i.e .. in what sense do the planes overlap?). Branching of the rupture surface seems to be an important element. 562 Line 117 "Based on empirical observations" implies that there is a direct linkage between the observations and the topologies, and little judgment required by the Tl Team. Isn't it more accurate to say that the topologies are developed by the Tl Team based on a consideration of historical earthquake ruptures that may be analogous to the ruptures in the region? 563 Lines 119 and 130 Isn't down-dip hyphenated? 564 Line 123-125 The description of slip rates for complex and splay rupture sources is ambiguous. For example, if the intended meaning is that the primary part of a rupture source (complex or splay) has a uniform slip rate and the secondary part of the same rupture source has a different uniform slip rate, please make that clear. 565 Line 132 This sentence seems to be missing a verb. Please correct for clarity. 566 Line 138-141 The only stated exception to the obtuse angle requirement is the Hosgri-Shoreline splay. Please explain how the Los Osos-San Luis Bay splay is consistent with this taxonomy (i.e., why isn't it also considered an exceotion to the obtuse anale reauirement?}. 567 Line 143 The "three types of features" does not seem to include major steps or bends, although the majority of historical ruptures had endpoints at steps or bends. Was this intended? 568 Lines 156-162 Please include references to the corresponding figures from Chapter 6 on which the segment locations are shown. 569 Line 164-166 This sen1ence is confusingly wri1ten. because the subject is "ruptures [across branch points!" and the direct object is also "ruptures." Please rewrite to make it clear that it is the branch points themselves that may be the sites of rupture arrest more frequently than are generic fault points. 570 Lines 170-174 This seems to imply that more ruptures will include both the Hosgri and San Andreas faults. versus the Hosgri-San Gregorio fault where it meets the San Andreas fault. Is this what you intended to mean? Please clarify. 571 Lines 231-234 In defending this conclusion, perhaps the point should be made that the CBR is supported by the careful review of analogies and the fact that the salient elements of the rupture topologies are supported by observations that they have occurred elsewhere during actual earthquakes. Are there hazard sensitivity cases that show this? 572 Line 266 Please consider replacing "in which to where 573 Line 275 Please consider replacing "Although this result was considered by the Tl Team in developing the rupture sources. ,, with -Although the Tl Team considered this result when developing the ruoture sources," 574 Line 281 Figure 9-2 Please spell out RO and LH on figure 575 Line 284 Approximately 6 km in which direction? 576 Line 285 Kawafune? Is this a fault name? Please specify "fault" 577 Line 286 If both were reverse displacements, it would be clearer to say "opposite sense of vertical slip" 578 Line 305 General dip angle? Do you mean average dip angle? The general direction of dip? Please clarify. 579 Line 309 Stretches? Do you mean extends? 580 Line 310 Is M6.5 a large earthquake? Most seismologists would consider this a moderate event. Rather than using "large", you could say "surface-rupturing earthquakes" 581 Lines 315, 318 No fault section has been defined to indicate what "that section of the fault" refers to. Please clarify. 582 Line 325 You should also reference Sieh, 1996, as this was one of his examples to argue for the slip patch model. 583 Line 336 Subsurface rupture? 584 Line 341 "bordered the flank" Do you mean bordered" or flanked". This statement is unclear, as written. 585 Lines 341-342 Are you referring to rupture of the Brawley fault? Please clarify this 586 Line 344 Please consider deleting "instruments". 587 Line 359 Please change "Displacement on" to displacement in 588 Line 365 "several major and many right-lateral faults"? Consider deleting "and many" or qualify as "many minor" 589 Line 367 Geodetic strain needs more clarity of meaning. Wasn't the geodetic strain fairly localized? 590 Line 369 Does a 30 degree change in strike count as sub-parallel?? 591 Lines 372-373 This is somewhat misleading and semantic. The Landers/Kickapoo fault is essentially co-linear with the southern section of the Johnson Valley fault (which wasn't recognized prior to the 1992 earthquake). Basically, the Landers and southern JVF are the same fault. The rupture stalled 592 Lines 375-376 593 Lines 378-380 594 Line 385 595 Line 386 596 Line 395, Figure 9-6 597 Lines 407 -408 598 Lines 412-413 599 Line 417 600 Lines 424-425 for 7 seconds at the intersection with the Homestead Valley fault, and then re-nucleated on the HVF to continue the rupture. Two major e11ents. See figure below. Valley Fault \ ,/?'tt-. '-:. \ . *iii.*'. Kickaooo fault ..* ,. . ....... ,_. ....,.,,.. --)\ ".'-.. \. *1 \ ... "" * .... ,, * .. HomesteadVaUey Fault -:"":. .,-. The step from the Emerson fault to the Camp Rock fault is not contractional -it is also a releasing step. Please provide references for estimates of stress drop and the relationship between stress drop and recurrence intervals (e.g., Rockwell et al., 2000) Please add year (2012) to Madden and Pollard. Please change "to better resolve" to to resolve better. Please explain "culled measurements" Angle of the prestress? Or just the fact that the main Denali was stressed whereas the eastern Denali was not, probably due to a recent failure. Please clarifv What is meant here? Most faults were previously mapped and named (Barnard, 1965). Are you just saying that it wasn't known that they would rupture together? In the same sense, the 1992 Landers earthquake identified a previously unknown fault system, and the southern Johnson Valley fault was not known in the literature. Please clarify. "Previously unidentified fault system" is an accurate quote from the study of Fletcher et al. However, many of the individual faults involved in that rupture were known and mapped beforehand. Please consider adding a few words to clarifv this point. Check this. There was a foreshock on a north-striking normal fault, but the mainshock initiated on a northwest-striking fault -the Laguna Salada fault. Please consider, given the uncertainties, whether a less categorical statement would be more aooropriate. Please clarify reversal in slip. This could mean normal to reverse. Right-lateral to left-lateral What you mean is that the dip direction switched from SW in the southern half to NE in the northern half of the rupture? 601 Line 429 Series of several?? Please clarify. 602 Line 447, Plale 9-1 Is HB vertical? If so, the surface projection of dipping rupture source (pink) slops south of HB. If correct, please state on plate 9-1 or in text. 603 Line 456 The phrase "uncertainty in the distance" could be understood to suggesl lhat it represents epistemic uncertainty. The way lhe model is employed, lhat does not appear to be the case, but rather that all of lhe Hosgri rupture sources occur on any one branch of the logic tree, so that the rupture sources collectively define aleatory variability. If the latter is the correct interpretation. please consider adding some clarification that it is actually aleatory variability in future rupture distances that is modeled by lhe device described here. 604 Lines 457 -459 Please add -with different dips -to the end of the sentence below "These sources are identical in length. extending from the south end of the Hosgri fault to the MT J, but they occupy different strands of the fault zone directly west of the DCPP. " 605 Line 4 71, Table 9-3 Please consider adding subscript to H-01 (75), H-02 (85), and H03 (90) in he table 606 Line 471 Table 9-3 How about just a section of the Hosgri fault as a characteristic rupture? Is this scenario accounted for in one of the models? Please clarify how shorter Hosgri fault ruptures are accommodated by this model as this seems to be the most likely scenario and it is not clearly presented. 607 Lines 476-486 Models H-01, H-02, and H-03 are essentially the same except for the site to source distance. In reality, they may all fail together as a broad zone -is that scenario in lhe model?? 608 Line 499 Consider changing analogy to analogous. 609 Line 502 "recent 20 dynamic ... " Define recenl". 2003 is 12 years old. Please clarify. 610 Lines 502-507 Please consider shortening sentence or breaking inlo parts. 611 Line 538, Table 9-4 Please explain why SH is secondary and BE+ BR are primary in OV-03 -this makes sense for the SW model but not for the OV -is it driven by slip rate? 612 Line 546 Consider rephrasing -"The south end the rupture source is the south end of the Shoreline fault source-the intersection with the Casmalia fault." to The south end of the Shoreline fault source at the intersection with the Casmalia fault is the south end of the rupture source. 613 Line 582 Figure 7-2 should be Figure 7-4? 614 Line 596 This would read more clearly if "an" was placed before "oppositely" 615 Line 605 Please explain why some ruptures continue to the MT J and some end at the north end of the San Gregorio fault. 616 Lines 630. 634 It is slaled here that SW-01 through SW-03 "acknowledge uncertainty" in whether the set of faults rupture together, but that SW-04 through SW-07 "describe variability" in ruptures on another set of faults. This contrast in language could leave the impression that one treatment is epistemic and the other aleatory, whereas it appears that the SSC model is set up to treat both as aleatory variability. If that is the correct interpretation, please consider using more consistent language to highlights that fact. If lhat is not the correcl interpretation, please clarify. 617 Line 661 Recent work has shown a strong strike-slip component on the Little Pine fault (Cannon, 2012) 618 Line 673 and 684 Figure 7-2 should be Figure 7-4? 619 Line 689 This is word-for-word the same as in the previous section -needs an "an" before "oppositely" for clarity. 620 Line 690 No comma is needed after California 621 Line 697 This would read more clearly with "that between "SWBZ and "could" 622 Line 703 You need a period at the end of the sentence 623 Lines 729. 730 Commas are not needed after "California or "Japan". 624 Line 734 This would read more clearly if you replaced "Like" with "As with" 625 Table 9-6 Please spell out Avenue for Wilmar Avenue fault, as it is a formal name. 626 Lines 740-749 Table This is another case where the switch in language from "uncertainty" to 9-61Plate 9-2. "variability" is a potential point of confusion. Please consider using consistent language to keep it clear that the range of rupture sources (within a given Rupture Model) represents aleatory variability. 627 Line 750 Please explain -LB and LE dip south -why is surface projection of rupture to the north? 628 Line 806 If rupture source NE-11 models "the possibility that the Morro Bay basin does not represent a step-over." doesn't this represent at least some conflation of epistemic and aleatory elements in the SSC model? That is. "represents a stepover" and "does not represent a step-over" are, on the face of it, mutually exclusive alternatives, so represent epistemic uncertainty. Yet they appear to occur concurrently in the NE logic tree branch. Please explain why this is not a contradiction. 629 Line 818 Please explain surface projection change along segments NL and FN in NE-07 (Splay) 630 Line 834 This results in faults that do not intersect at depth unless the Hosgri ruptures south of the intersection. 631 Line 851 Please remind the reader of what the first piece was. 632 Line 852 It would help the reader to remind them that the slip rate allocation will ultimately provide information related to earthquake recurrence rates 633 Line 880 If this feature (greater slip rate) is merely the definition of primary," please make that clear (otherwise it is ambiguous, because there is the alternative that "primary** has been defined on some other criteria and then this sentence becomes a rule about assigning relative slip rates). 634 Line 881-882 The slip rate should be greater by an amount proportional to the ratio momentfarea of each part (not the moment alone). Please correct this statement (although it is cleared up in the subsequent equations) 635 Line 891 Units should be specified here (e.g., the seismic moment given by Eq. 9-4 is in dyne-cm) 636 Line 97 4-977 This sentence is confusing. The first clause appears to be just a partial restatement of a more precise statement in the second clause. Please rewrite to improve clarity. 637 Line 1006 Please state the criteria that were used to conclude that the fits were satisfactory. 638 Line 1022 Table 9-8 As 89% of the rate is on the H-01, H-02, and H-03 models, does this imply that these ruptures extend all of the way to the MTJ? This is not entirely clear, as presented. 639 Line 1046 There are eight Hosgri rupture sources. If the reference on this line to "the five Hosgri rupture sources" is meant to refer only to those that rupture the Hosgri Fault Source, please indicate that, and in any event olease clarifv the statement. 640 Line 1048 Table 9-9. It is 54% not 65% as stated in Explanation column H-01 (Central strand) 641 Lines 1055-1058 If the location is aleatory, then the relative frequency of each location must be defined by the Tl Team. Please inform the reader how the relative frequencies (fractions) were assessed by the Tl Team. What types of data were considered? What was the role of different types of data (e.g., geomorphic expression. analogs, indications of vertical component of slip)? The reader needs to know that this is an expert assessment process (i.e., the numbers don't just fall out of the calculations), but the expert judgments are informed by a variety of data constraints. 642 Line 1062 Please consider replacing "not as continuous a trace" with -a discontinuous trace 643 Lines 1064-1067 What if one or more strands were more strongly strike-slip (i.e., different horiz/vert ratios)? How does this compare with the offset channel data from LESS Lines 1215-1216? 644 Line 1077 'The plant" is elsewhere called "the DCPP." Please consider keeping the terminology consistent. 645 Line 1077 Please consider adding two letter segment after "western reach of the Hosgri fault source' (HB) so ii not confused with HW 646 Line 1087 If "relative merits of this configuration compared to others" means compared to other options for filling in the limited Shoreline Fault slip budget. please add that clarification. Otherwise, add some explanation o1 what the phrase means in this context. 647 Line 1090 It would be useful to explain the difference between the 54% allocation and the approximately 65% estimated based on vertical separation. Please explain why these values are not in conflict with each other. 648 Line 1097 The Hosgri slip rate CDF seems to have been presented in Section 8.3.7 (not 8.3.3). Please check and correct if necessary. Also please explain why the Hosgri slip rate CDF shown as a solid black curve in Figure 9-9 is called a "discrete Hosgri CDF" when it appears in the figure to be a continuous function. and seems to be presented as a continuous CDF in Section 8.3.7 (e.g., Figure 8.3-20). In what sense is it discrete" (that term would seem more appropriate for the logic-tree CDF, and the term is used in that sense on Line 1101 )? 649 Line 1099 Please replace "it is a satisfactory with "it provided a satisfactory." 650 Lines 1101-1102, The phrase "discrete CDF of all logic tree branch combinations and their Lines 1165-1166, and weights" is not clear. Please clarify (e.g., it would be clearer to say Lines 1243-1244 something like "discrete GDF of all weighted logic tree branch combinations" if that is the intended meaning) 651 Line 1130 It is understood that the "preferences" identified in this paragraph and the next two paragraphs are implementing the two principal bases for the allocation discussed in the paragraph starting with Line 936. However. the reader needs to have a better idea of how the application of the bases is applied in each case discussed in these three paragraphs. For example. why does the Tl Team have a preference that the Shoreline fault slips either along or as part of the Hosgri fault? Is it the least complex topology for accommodating slip? More consistent with analogs? Likewise. in the next paragraph, why is 92% allocated to reverse-only rupture sources? The technical bases for the allocation amounts need to be given. especially because they are based on expert judgments. It is comparable to providing technical justification for the weights assigned to logic tree branches: there needs to be some basis given in the text or the decision will look arbitrary. 652 Lines 1134-1136 Please consider changing sentence to: The remaining slip rate is allocated approximately evenly between the shorter (OV-03) and longer (OV-04) complex ruptures whereby the Shoreline fault source ruptures as part of multi-fault complex rupture involving both strike-slip motion and reverse or reverse obliaue motion. 653 Line 1161 Figure 9-Why is OV-05 at the top of the list in the legend? 10 654 Line 1173 For clarity, spell out numbers in this paragraph as the get lost with the other numbers. 655 Line 1185 H-05 -This should be 23% of Shoreline fault slip budget and then table for the SW model will sum to 100% 656 Line 1185 Please explain -SW-06 source of 0. 086 is 100% of total budget for Los Osos source, but is listed at 45% 657 Lines 1215-1216 0.09 mm/yr is not 45% of 1.9 mm/yr. it is 4.5%. Is there a typo here? Please clarify. 658 Line 1215 "The total slip rate of less than 0.09 mm/yr is approximately 45% of the geologic rate of slip of 1.9 mm/yr attributed to the Los Osos fault in the SW Model (Section 8.5)." Total is listed as 0.09 for Los Osos in Table 9-13 -please make consistent 659 Line 1217-1220, and Please expand the technical argument supporting the 0.45 coupling 1290-1297 coefficient for the Los Osos Fault in the SW model, and the 0.57 coefficient for the San Luis Bay Fault in the NE model, especially any empirical support. For example, if there are geologic analogues that favor decoupling of approximately this magnitude. please cite. If this value is a source of significant hazard sensitivity, please explain how the SSC model accounts for uncertainties in the coupling coefficient. If it is not a source of significant hazard sensitivity, please state that and cite the hazard sensitivity analysis that establishes that fact 660 Line 1220 Field el al.,2014, does not appear in the list of references. 661 Lines 1251-1256 Spell out numbers in this paragraph as well, for clarity. 662 Line 1290 "Combined, these rupture sources accommodate approximately 0.09 mm/yr of seismogenic slip rale on the fault, or approximately 57% of the total 0.16 mm/yr slip rate attributed to the San Luis Bay fault in the NE Model (Table 9-15; Section 8.6)." Allocated 0.092 total slip for San Luis Bay Fault in Table 9-15 not 0.16 mm/yr -please make consistent. 663 Lines 1313-1314 Consider including the slip rate CDF information in a caption or the notes for each of these types of figures. 664 Line 1333 Table 9-Hosgri +SW Models and Hosgri +NE models do not add up lo 100% as 17. shown in Table 9-17. 665 Line 1356 Mighl want to add supporting arguments why lhis higher-than-target slip rate on the Hosgri faull north of the DCPP will not meaningfully affect the hazard results for the DCPP. 666 Lines 1406, 1473, Please complete these citalions. and 1477 667 Table 9-t7 Please clarify why the western reach of the Hosgri fault has a negative slip rate. Cross-check lhis with lines 1344-1345 and clarify what/how it was done. 668 Figure 9-2 Is it really negative vertical offse!? Subsidence? Plus. technically, offset is a strike-slip term. 669 Figure 9-3 The arrow showing lhe northern exlent of rupture in Yeats' figure is misleading, as both the 1940 and 1979 ruptures extended north of this point. 670 Figure 9-7 The note on the figure states that two dominant fault zones are shown by thick black lines. It is confusing that, for the most part, these black lines are covered by green or yellow lines showing other attributes (also true in Flelcher et al.'s published version). Please clarify this issue in the fioure note. 671 Figure 9-11 An explanation is needed with lhe figure that the individual rupture source CDFs sum lo the Lognormal SLB GDF 672 Figure 9-9 through 9-The Hosgri slip rate CDF (solid black curve) in panels a and c of Figure 14 9-9 is labeled "Discrete Hosgri CDF." But it appears to be a continuous CDF, and that is also the impression left by Section 8.3.7. Please clarify or correct the figure label. Same comment applies to the CDF plots for other faults in Figures 9-10. 9-11, 9-12, 9-13, and 9-14. CHAPTER 10-Magnitude Distribution Models 673 Line 7 lsn*t the shape actually defined by the magnitude PDF, while the MFD actually incorporates the seismic moment rate? 674 Line 40 Might qualify this statement to indicate "earthquake magnitudes that give rise to significant ground motions." It might be argued that the historical/instrumental record provides a pretty good basis for assessing the rates of M3 earthquakes. 675 Line 50 Table 10-1 Within the WAACY box, doubly-tuncated should read doubly-truncated. 676 Line 61-62 Please state what lengths would typically be hypothesized to be characteristic, and provide justification or a reference that does so. Or, if that discussion is provided elsewhere in the report, please provide a specific (chapter, section number) reference. 677 Line 79 This sentence appears to be a direct contradiction of sentence beginning on line 520. Please rectify this apparent contradiction or explain why it is not actually contradictory. 678 Line 84 Here and elsewhere in the text. this should be termed the "characteristic earthquake model". 679 Line 97-98 Please improve this explanation of conditions for use of the characteristic PDF. because the explanation seems more or less circular without a quantitative statement of the rupture-source length criterion. 680 Line 104 The word .. but" is a source of confusion. because it suggests that the second clause is going to qualify the first, whereas the second clause actually seems to directly reinforce the first. Please check whether the intent of the sentence would be more efficiently communicated if the word were chanqed to "and." 681 Line 127 And what are the disadvantages? (difficulties in assessing the various parameters?) 682 Line 150-151 The phrase "the logic tree ofWAACY parameters values and weights are correlated with" is unclear (e.g., does it mean "the parameters values and weights in the logic tree are correlated with"?). Please rewrite the sentence to clarify its intended meaning. 683 Line 154 Suggest a section title that is more specific to Mchar and Mmax. otherwise, the section could refer to the selection of the particular type of magnitude to be used (Mw, Ms, etc.). 684 Line 183 Check spelling on paleoseismic. 685 Line 197 Please consider rephrasing -This prediction is supported to an extent by empirical data. which include no step-overs wider than 4 km (Wesnousky, 2008) or 5 km (Lettis et al., 2002), but not in detail, as Wesnousky (2008) found that among step-overs less than 4 km wide, there was no relationship between step-over width and likelihood of arresting rupture. 686 Line 204 The phrase "energy in rupture momentum" is not physically meaningful. In fact, at least in the limit of a very narrow process zone, a rupture front does not carry any momentum at all, in the sense that rupture speed can respond instantaneously to changes in stress, frictional resistance, etc. Please substitute more appropriate language. 687 Line 208 Soften -replace indicate with suggest 688 Line 208 This would read more clearly with a comma after "lengths". 689 Line 212 "where fault traces more abruptly bend" would read more clearly as "bend more abruptly". 690 Line 214 Please consider replacing "than where they are less pronounced" with "where offsets or bends are more pronounced" 691 Line 222-223 "The maximum M,.,., value for all Primary fault sources bypasses essentially all proposed segment boundaries." Are these wall to wall ruotures? Please exolain 692 Line 239 Please change "materially" to substantially -remove any material properties confusion 693 Line 247 Replace "Points" with Features 694 Line 286 Please check for missing verb on this line. 695 Line 287 Delete "and" between intersection and had for clarity 696 Line 296 consider replacing "considered lesser in degree" with "less well developed" 697 Line 300 This line is unclear. What are alternates? Please check whether the word "alternatives" (rather than "alternates") better corresponds to the inlended meaning on this line. Or is it allernalive traces? 698 Line 303 Faults joining? The activily of faulls that inlersect the main trace is low?? Please clarify. 699 Line 307 Replace "short" wilh finile 700 Line 314 Please make it clearer whal is meant by "to define the limils of soft segment boundaries along fault sources:* 701 Line 330 Please insert caplure in front of magnitude 702 Line 330 Please check whether the word "given** (rather than "provided") would better convey the intended meaning. 703 Lines 333-336 The range of magnitudes predicted by the allemative rupture lengths considered using any single magnitude-scaling relation is much greater than the range of magnitudes predicted for any single rupture length (or area) from a suite of magnitude-scaling relations. This sentence is difficult to parse. Please rewrite and clarify this statement. 704 Line 340 Delete extra "do" for clarity. 705 Line 340 Please explain why the SSC forward-modeling approach implies weaker sensitivity to magnitude-area scaling compared with the inversion approach of UCERF3. 706 Line 347 "This review included other evaluations of alternative scaling relalions and their relative merits for use in seismic hazard analysis (e.g., WGCEP. 2003; Shaw. 2013a: Stirling et al. 2013)." Redundant -please remove. 707 Line 360 Use a comma after SSC model, rather than a colon. 708 Line 361 "strike-slip Hosgri fault. lesser but significant" is unclear. Perhaps insert "whereas" before lesser? 709 Lines 367, 368, 369 Abbreviated HB02 -please add "as" so it reads "abbreviated as HB02" 710 Line 370 Abbreviated as??? How is this designated? 711 Line 376 EB02 should be EB03? 712 Lines 378-380 HB08 data set looks more comparable with YM11 than NGA-W2 data set? 713 Line 385 EB02 should be EB03? 714 Line 438 Here you use a 12 km depth for characteristic ruptures, but the implicit assumption is that these only apply to shorter faults, and not the Hosgri. Perhaps it would be good to make this clarification here rather than below (lines 451-453) 715 Line 447-450 The argument in this sentence appears to be that it is acceptable to under-represent aleatory variability of magnitude because epistemic uncertainty is broadly sampled. Please justify quantitatively why this tradeoff is acceptable (for example, this might be done by referencing available hazard sensitivity analysis). 716 Lines 451-455 Please provide supporting evidence for the stated hypothesis that only the largest earthquakes rupture with depth greater than the depth limits inferred from background microseismicity. 717 Line 454 The wording "depth of crust derived from proxies such as the D90 or D95 values** implies incorrectly that D90 or D95 can be interpreted as proxies for the depth of the crust. They are proxies for depth of the seismogenic zone, and perhaps for the brittle-ductile transition depth Please make appropriate changes. 718 Line 458 Please state the technical justification for selecting M 7.3 as the threshold for rupture deeper than 12 km. 719 Line 468 The figure uses 130 km. Please make consistent. 720 Lines 471-474 This aleatory variability is considered by the Tl T earn to represent a combination of magnitude variability given the rupture area and rupture area variability of the characteristic earthquake given the approximate definitions of the soft segmentation points used to define the characteristic ruptures. Please rewrite this with one less "given, as it is difficult to parse. 721 Line 480 Don't capitalize "The" 722 Lines 485-489 This sentence is confusing -please rewrite for clarity 723 Line 490 Was any consideration given to the manner in which the exponential relationship would need to be implemented? Studies of other active faults show that the observed seismicity occurring within a narrow zone along a fault is not compatible with the exponential shape of the recurrence curve unless a very large Mmax is adopted (e.g., Hecker et al. 2013). Was there any attempt to examine the recurrence distribution along the Hosgri fault or other faults based on seismicity? The same arguments made below between the exponential and WAACY model with respect to repeated slip at a point could be made here to justify the zero weighting of the exponential model for Category A rupture sources. 724 Line 500 130 km in the figures -please correct to a common value. 725 Line 504 Please consider whether the challenges to the exponential PDF identified by UCERF3 (Field et al., 2014) constitute another factor (in addition to the Hecker et al analysis) in the Tl Team's judgment to give that PDF substantially lower weight than given the WAACY PDF. 726 Line 504 Please insert paleoseismic before data 727 Line 506 Replace "confidence" with determined 728 Line 509 The inclusion of Figure 10-5 with virtually no accompanying explanation in the text or caption is extremely confusing. The figure makes reference to undefined "Group A," Group B". and Group C". and the reader naturally associates these with the "Category A," "Category B," and "Category C" magnitude PDF categories that have just been introduced in the text at this point (only to eventually discover that there is no such connection). Please either make some use of the figure, with a full explanation, or delete it. 729 Line 514 Please define "available data "There is an implication that these endorsements of the exponential distribution for faults were made after giving due consideration of the Hecker et al. data regarding slip per event. What types of data were considered by these authors and is it possible that they would endorse the WAACY model over the exponential model if they had considered all "available data" presented by Hecker et al.? 730 Lines 516-517 A potential criticism of the maximum magnitude model for hazard analysis is that smaller magnitudes are not provided for in the distribution for each rupture source It could be noted that the use of the model in conjunction with seismic source zones to account for smaller magnitude seismicity ensures that all magnitudes smaller than the maximum are included. 731 Line 520-522 The statement about Category C rupture sources is that "aleatory magnitude variability is introduced by involving more than one scenario with defined relative frequencies. But Line 79, also in regard to Category C rupture sources, states that "epistemic uncertainty is incorporated by considering alternative scenario earthquakes." Please explain why this is not a contradiction, or make changes to provide a consistent description of the intended treatment of variability in the Cateaorv C rupture sources. 732 Line 536 Insert model after UCERF3 733 Line 557 "at random" may read better as "randomly" 734 Line 568 "the left end?? Left end of what? One end? South or north end? There is no "left" or right ends of a fault without a reference frame. 735 Line 570 Same comment. "on the right" could read "towards one end" 736 Line 572 "of 60 km long" -this would be clearer with a hyphon between km and long 737 Line 574 Please write text and one or more equations explaining precisely what quantity is plotted in Figure 10-6 and how that quantity is applied to the magnitude PDFs (e.g., what is a "reduction rate-the term "rate" implies it has units, yet from the range of values in the plot, it appears to be dimensionless; assuming it is actually a dimensionless adjustment factor, what quantity does it multiply to implement that adjustment? How do you go from the curve in Figure 10-6 to the results in Figure 10-7; how does the quantity in Fiaure 10-6 combine with the factor LIL.?). 738 Line 584 Please give a precise definition of "geometric reduction" and how this term is distinguished from. and related to, the terms "rate reduction" labeling the axis in Figure 10-6 and reduction rate" introduced on Line 574. 739 Line 592 It is stated on this line that the exponential model leads to a point MFD that has a "gentle upward deflection" for larger magnitudes. There is no upward denection on the point MFD (blue) curve in Figure 10-7a (nor is it clear why one would be expected). Please clarify 740 Line611 Please explain the phrase "arithmetic sum by magnitude" 741 Line 623-624 Please check whether the phrase "alternative earthquake scenario magnitudes and frequencies for complex and splay rupture sources" actually communicates what is intended. If so, please explain how alternative" scenarios can be reconciled with the sentence beginning on Line 520 that says Aleatory magnitude variability is introduced by involving more than one scenario earthquake pair, whereby the relative frequency of the scenario earthquake pair is defined. The scenarios are either "alternatives" or they occur collectively with some "relative freauencv," and it is not clear how both statements can be correct. 742 Lines 636-637 Figure 10-4 shows 130 km as the break between category A and B rupture sources. 743 Line 653 It is not clear what is meant by "alternative aleatory logic tree branch values." Table 10-5 refers to "scenario frequency," suggesting that all of the listed scenarios occur on a single logic-tree branch and represent aleatory variability, not mutually exclusive alternatives. So please explain what the alternative" logic tree branches are in reference to Table 10-5 The confusion about the status of the Category C rupture sources seems to be systemic in this chapter: Note the related apparent contradiction between sentences beginning on Line 79 and Line 520, and the related issue on Line 689 (with reference to Table 10-8) and Line 722 (with reference to Table 10-11) 744 Line 655 Please explain how the assessment of the relative frequency of the scenarios relates to the shapes of the MFDs. What was the thought process used by the Team? 745 Line 658 "favors" instead of "favored"? 746 Line 670-71 Same as comment for Line 623: Please check whether the phrase "alternative earthquake scenario magnitudes and frequencies for complex and splay rupture sources" actually communicates what is intended. If so, please explain how "alternative" scenarios can be reconciled with the sentence beginning on Line 520 that says "Aleatory magnitude variability is introduced by involving more than one scenario earthquake pair. whereby the relative frequency of the scenario earthquake pair is defined." The scenarios are either "alternatives" or they occur collectively with some "relative frequency," and it is not clear how both statements can be correct. 747 Lines 672-673 It would be helpful to indicate where on the figures these segment boundaries can be found. Perhaps add a column to the table what makes reference to the applicable fiaure. 748 Line 674, Table 10-6. Why is LC. HN, HD not a tier 1 as there is observed a pronounced difference in sense and rate of slip between the two faults? 749 Table 10-6 "South end of Little Pine fault"?? This fault strikes southeast -please correct the strike. 750 Table 10-6, LO, LE Different slip rate or difference in slip rate?? Please fix. box. 751 Line 677 Only double asterisk for SE"" 752 Line 687, Table 10-7 Suggest including "Rupture Source Magnitude PDF Category" (rather than just "Category") in this heading to remind the reader. 753 Line 687, Table 10-7 Please provide some discussion of how the weights for Mchar and Mmax were assessed. 754 Line 689 Same comment as for Line 653: It is not clear what is meant by "alternative aleatory logic tree branch values," given that Table 10-8 appears to describe relative frequencies, not mutually exclusive alternative models. Please explain how to interpret Table 10-8 in terms of alternative logic tree branches. and how that is consistent with the aleatorv nature of the variabilitv imolied bv the term "relative freauencv." 755 Line 700 This would read more clearly with a comma after "sources". 756 Line 702-703 Same as comment for Lines 623 and 670: Please check whether the phrase alternative earthquake scenario magnitudes and frequencies for complex and splay rupture sources" actually communicates what is intended. If so, please explain how alternative" scenarios can be reconciled with the sentence beginning on Line 520 that says Aleatory magnitude variability is introduced by involving more than one scenario earthquake pair. whereby the relative frequency of the scenario earthquake pair is defined." The scenarios are either "alternatives" or they occur collectively with some "relative frequency, and it is not clear how both statements can be correct 757 Table 10-9, SE** box "Postulated South end" -south should be lower case. Also, shouldn't this be southeast end, as the fault strikes NW-SE?? This comment also applies to other tables with identical verbaQe, such as Table 10-12 758 Table 10-9, LP box Same comment as above -the Little Pine fault has a NW-SE strike. so this should read the southeast end. This comment also applies to other tables that use identical verbage, as in Table 10-12 759 Table 10-9 SH-HB marked difference in slip rate -Tier one? 760 Table 10-11, SW-04 The hazard implications of the M8 scenario that includes the Hosgri will box need to be considered in Chapter 14. In particular. the implications of assianina a 10% relative freauencv should be discussed. 761 Table 10-12, SA box Fault is capitalized here. and small case elsewhere. Be consistent 762 Table 10-12, WB, SS, Please add fault after Wilmar Avenue, for clarity. SF box 763 Line 713 There isn't any "description" provided in the table. 764 Line 717 Figure 10-Please explain surface projection pattern for NL? 30. 765 Line 722 Same comment as for Lines 653 and 689: It is not clear what is meant by alternative aleatory logic tree branch values," given that Table 10-11 appears to describe relative frequencies, not mutually exclusive alternative models. Please exp la in how to interpret Table 10-11 in terms of alternative logic tree branches, and how that is consistent with the aleatory nature of the variability implied by the term "relative frequency." 766 Line 737-738 Same as comment for Lines 623, 670 and 702: Please check whether the phrase "alternative earthquake scenario magnitudes and frequencies for complex and splay rupture sources" actually communicates what is intended If so, please explain how alternative" scenarios can be reconciled with the sentence beginning on Line 520 that says "Aleatory magnitude variability is introduced by involving more than one scenario earthquake pair, whereby the relative frequency of the scenario earthquake pair is defined." The scenarios are either "alternatives" or they occur collectively with some "relative frequency, and it is not clear how both statements can be correct 767 Line 742 Table 10-12 SH-HB Tier one segment boundary? 768 Line 744 No asterisk in Table 10-12 769 Line 752 Figure 10-36. Please explain -if the dip of the Los Osos is 60. -why doesn't the surface projection of the rupture parallel the fault? 770 Line 756 Same comment as for Lines 653, 689:, and 722: II is not clear what is meant by "alternative aleatory logic tree branch values," given that Table 10-14 appears to describe relative frequencies, not mutually exclusive allernative models. Please explain how to interpret Table 10-14 in terms of alternative logic tree branches. and how that is consistent with the aleatory nature of the variability implied by the term "relative frequency." 771 Line 762 Tables 10-14-some descriptions (Faults) have main or splay written in column but not all -please make consistent for all tables 772 780 Please specify (at least on the figure caption or figure notes) the magnitude bin size used for the incremental distribution (since the curve does not appear to be normalized to unit magnitude increment). on this figure and other MFD plots (otherwise the incremental and cumulative plots cannot be reconciled). 773 Line 798 This seems to be the first occurrence of the term "reduced source MFD." Please define it (e.g., is it distinct from the Point MFDs in Figure 43?). 774 Line 803 Figure 10-44 caption. "the rates for both subevents is the same" replace is with are 775 Line 805 Please clarify the meaning of "Hosgri source MFD." 776 Line 807 Might rephrase to indicate that these sources are characterized using the maximum magnitude PDF. Otherwise, it may be unclear what is meant by "simplified maximum magnitude sources:* 777 Line 829 Figure caption -please remove one "at the" in the phrase "al the at the Hosgri subevent" 778 Line 847 Figure 10-45 appears (based on the slope of left-hand extreme of the cumulative curve) to have been constructed with a magnitude bin size of approximately 0.05 magnitude units, whereas (judging by the slope breaks on the blue curve) Figure 10-46 appears to have been constructed with a magnitude bin size of approximately 0.1 magnitude units. If it is the case that they were constructed with different bin sizes, please explain what normalizations were done to ensure that these curves are comparable. If the apparent difference in bin sizes is illusory, please clarify. 779 Figure 10-3 Correct the spelling of "strike" in the header for the top figure (a). Also, why not use the same symbols for the models that are in common between the two fiQure parts (a and bl 780 Figure 10-45 Definitions of the dashed and solid lines in the Explanation are reversed. 781 Line 863 "or some other feature of the inversion solution (Page et al., 2014 )." Please clarify some other feature 782 Line 866 Figure 10-Please change is to are "the rates for both subevents is the same." 47. Please correct for all odd numbered figures that follow Figure 10-47 in this section. 783 Line 883 Whether the ground motions will be higher or not is a GMC and hazard issue. It is suggested that the reader just be reminded that other sources contribute to these scenarios besides just the Shoreline fault portion. 784 Line 973 Replace is with are APPENDIX -WAACY Model 785 Line 27 Might want to use another word than characterize as it might introduce confusion with "characteristic model" 786 Line 34 Is this the motivation that the authors of the model had for developing it in the first place? If so. this should be past tense. 787 Line 44 Any recurrence curve, by definition, permits a broad aleatory variability in magnitude. Not clear that this is an actual constraint. Isn't the real constraint that large Mmax's are allowed (more than the characteristic earthquake model) and small CVs are met (unlike the exponential model)? 788 Line 47 Note the missing")". 789 Lines 52-53 Please clarify what the distinction is between "fits a doubly-truncated exponential" and "is a doubly-truncated exponential". 790 Line 68 Mmin of 5 is used for hazard integration, but is not common practice for purposes of earthquake recurrence, especially when filling recurrence curves to observed seismicity. 791 Line 68 Table W-1, "Values larger than 3 yield results that are indistinguishable from 3 for bhighbox the DCPP." This is a bit confusing. Why not state that "values of 3 and larger yield results that are indistinguishable at DCPP" 792 Lines 78-79 What units are used in Dave? Centimeters? Meters? 793 Line 92 Replace SOS, 13 with S09, 13 794 Line 104 Please check whether this is the first reference in the text (apart from Table W-1) to the 0.55 value of the displacement CV threshold. If so, please indicate here that you refer to the 0.55 threshold estimated by Hecker et al. (2013). 795 Line 139 Suggested should maybe be "suggest", as it still applies. If accepted, change "included in line 140 to include". 796 Line 142 It appears that instead of "values and weights" of the fixed parameters being shown in Table W-2, it is actually parameter name and fixed value. Please clarify. 797 Lines 209-211 "We note that for Group B cases, the parameter combination of 12% moment and = 1 exceeded the CV threshold value of 0.55 (Figure W-5)." Please discuss weighting for Group B versus Group C for 12% moment in Figure W-7. Based on Figure W-6. It appears that Group C should have an equal or lower weight than Group B for the 12% moment? Comment Location in Text Number 798 Line 1 799 Line 2 800 Line 12 801 Line 17 802 Line 35 803 Lines 39-40 804 Line 42 805 Lines 43-46 806 Line 52 807 Line 57-59 808 Line 64 PPRP Comment Response Table Installment #4 PPRP Comment CHAPTER 13-Areal Source Zones Please consider adding some additional introductory information, such as the topics that will be covered in this chapter. Delete "of." "but the faults are not sufficiently active to be considered" Consider adding "or well-constrained or studied as there may be other faults of similar activity to the Shoreline fault that have simply not been identified or studied. It would be useful to acknowledge that, although it is recognized that moderate-to-large earthquakes rupture finite lengths of faults, at large distances those ruptures can be approximated by ruptures effectively at a point for purposes of seismic hazard analysis. Add "smoothing" after Gaussian. Please give the units for the quantity 1 O" (e.g., is this an annualized rate for M>O events?). A factor of 0.1 would appear to be the correction factor for accounting for the 0. 1 magnitude increment, not the factor 0.184 cited on this line. The latter would appear to account for the 0. 1 factor multiplied by the additional factor 1.84, which equals bx log.(10), and accounts for the relationship between the exponential density function and the Gutenberg-Richter cumulative distribution. Please check whether this explanation is correct and make any required changes in the text. This leaves the reader wondering what the implications are for the research coming out after the model was locked down. Please explain how this is relevant -did you use it or not? If so, then consider deleting this sentence. as it is irrelevant. If not. then close with a statement of what was and was not used. As it is. there is no final context to understand the meaninq of this sentence Replace we make" with "the Tl Team makes." This sentence as written seems to say that the given latitude/longitude range is that part of the Regional ASZ that extends beyond the 320 km limits. whereas Figure 13-1 makes it clear that the given latitude/longitude range actually defines the full Regional ASZ (and this full range happens to extend beyond the 320 km limits). Please rewrite to clarify the meaning. The concept of a "DCPP Site Vicinity seems to be important enough to be named and capitalized. yet has not been defined up to this point in Chapter 13. From Figure 13-1, it seems to be defined by a 40 km radius circle centered at DCPP. but this has not been made explicit. Please make sure this term has been defined prior to its use, and also be Summary of Revisions to Report consistent with capitalization (e.g., note that the term is capitalized in the text, but not in the figure legend). 809 Lines 67-68 It is not clear at this point why two catalogs are being considered, how the comparisons with the predicted rate will be done, or what "adjustments to the baseline gridded seismicity rates means. Please provide more explanation and context. What type of "adjustments" would be made if there are differences? Or reference other parts of the report where these issue are discussed. 810 Line 74 It would help the reader to also indicate that those two catalogs are discussed below 811 Line 75 Considered for what? Remind the reader what the catalogs are being considered for and how they will be used. 812 Line 88 This would read more clearly if "the" was placed before "Felzer" 813 Line 88 This is a methodology section, but it would help the reader if a pointer was made to the section where the conclusions from exercising the methodology for the Vicinity sources are given. 814 Line 106 Again, a pointer to where the Local sources are described would be useful. 815 Line 117 Please be specific about what quantity is plotted in Figure 13-2 (e.g., is it the annual rate of events in a 0.1 magnitude-unit wide bin centered on MO, per 0.1 x 0.1 degree spatial bin?). 816 Lines 124-125 Please provide further technical support for the 70%-30% distribution (e.g., is it consistent with focal mechanism distributions where those data are available?), or reference sensitivity studies or other evidence that indicate that the effect of this distribution is not hazard sianificant. 817 Line 142 Please consider replacing second "and" in the sentence with .. as well as" 818 Line 149 Agreed that it is a less clear association. but Edna and the western portion of the Los Osos show some spatial association with microseismicity -please consider softening by using "less clear association" -rather than "no clear association" 819 Line 154 Please consider "higher density" as a replacement for (the slightly awkward) "qualitative[ly) greater number." 820 Line 189, Table 13-2 This table needs a caption explaining each of the Table elements. Also, the implied scale factor is not clearly explained. 821 Line 207 Consider replacing "that" with "as to which" for clarity 822 Line 209-211 Please state why this 3-point distribution is an adequate representation of the CBR of the TOI. 823 Line 218 Consider changing to a "greater extent" 824 Lines 215-223 Consider breaking up this very long sentence, for clarity. 825 Line 247 "study" should be plural. 826 Line 248 Please define what is meant by virtual faults." or indicate in the text that this term is used in a sense that will be explained later in the chapter. 827 Line 250 Please define what is meant by "semi-randomly," or indicate in the text that this term is used in a sense that will be explained later in the chaoter, if that is the case 828 Line 254 Need an introductory sentence that states what this section is about. 829 Lines 257 and Consider using a. b c, etc rather than#. x, and y for the 2014 PG&E numerous other citations. Also, there are 8 PG&E 2014# citations listed in the references locations section. Please rename them all so the reader knows which citation refers to which reference. 830 Line 282 Replace "was" with "were." 831 Line 285 The word inference is pretty weak. How about. "it can reasonably be concluded? 832 Line 304 Figure 13-6 should be 13-5. 833 Line 315 To the extent possible, it would be preferable to replace references to workshop presentations by references to published reports or papers. For example, please consider whether the pertinent part of McLaren's powerpoint presentation could be covered by references to Mclaren & Savage (2001) and to the 2011 PG&E Shoreline Fault report. Please check on the viability of similar substitutions for the other workshop powerpoint presentations cited in this paragraph 834 Lines 327 -332 Consider breaking this long sentence into a couple of parts to assist the reader. 835 Line 332 This sentence would read more clearly if "is more problematic" was placed after "Local Source Zone" in line 331 . 836 Line 341 Please state the basis for the Tl Team judgment that the method and results are unreliable for identifying laterally continuous fault sources in this context. 837 Line 346 The dips might be consistent: however. the OADC-FM fault plane solutions dip in the opposi1e direction lo the dips in the NE and SW vergent models as well as dips interpre1ed from seismic and well data in 1he CCCSIP. Please clarify. 838 Line 348 "Map" should be plural. 839 Line 351 Please consider deleting "compiled from that effort" 840 Line 359 Insert "shown" (i.e., "is shown on"). 841 Lines 365-367 Might consider rephrasing -The Tl Team judged that the quality of the seismic reflection data used to delineate the faults was poor and introduced much uncertainty in mapping fault dip and architecture, a concern exoressed bv the authors (PG&E, 2014#, Chaoter n 842 Lines 371-37 4 Also might want to mention that even though the interpretations are uncertain they are constrained/consistent with well data in the region. 843 Line 384 "within the" is repeated -please delete one 844 Lines 389-392 Please explain why the existence of a residual uncertainty as to the amount of strike-slip deformation present would justify assigning strike slip a higher frequency of occurrence relative to the reverse style (i.e., if I have a C average on half the class assignments, and don't turn in the other half, there is residual uncertainty about how many A's I would have aotten, but this mav not iustifv raisina mv arade to a Bl 845 Line 396 Remove hyphen in half-way; also please check hyphens throughout text (e.g., line 389, well constrained needs a hyphen). 846 Line 421 Note typo: "Where" should be lower case. 847 Line 421 As noted in a previous comment. the factor 0.184 appears to account for both the magnitude increment and the transfo1TT1ation from the incremental to the cumulative magnitude-frequency relationship. Please check and make aoorooriate chanaes in the text. 848 Line 452 Table 13-3 has NE and SW dips for both strike slip and reverse -the logic tree in Figure 13-14 has Nor NE and Sand SW for reverse faults -olease make consistent. 849 Line 457 Please add at this point in the text that "slip rates for the virtual faults" in this context will mean the sum of slip rates across all the virtual faults Currently this is a point of confusion until it is finally explained on Line 491-493 and in the footnote to Table 13-5. 850 Line 466 Might want to add some supporting info1TT1ation as to why less than about 4. 851 Line 472 Please check whether Mo on the left side of Equation 13-5 should actually be Mc .*. If so, please correct, and if not, please explain what Mo.1 means on the riaht side of Equation 13-6. 852 Lines 479 and 480 The "s" needs a dot above it to indicate that ii is slip rate. Otherwise, this equation will be mistaken for the equation for Mo. Use of "s" for slip is standard notation. so using it without the dot for slip rate will be confusing. 853 Line 505 Please check and correct this rate. which should probably be O 07 mm/yr. 854 Figure 13-1 Using colors in the explanation is a little problematic as they don't match the colors in the figure in a consistent way due to overlapping color with some transparency. For instance, the regional source zone has a different color onshore versus offshore. 855 Figure 13-2 Please give the units for the rates shown in the legend (e.g., indicate that they are annual rates if that is the case), and be specific (in the text or a caption or note on the figure) about what quantity is plotted. E.g., does it represent the annual rate of events in a 0.1 magnitude-unit wide bin containing Magnitude 0, as estimated by 0. 184 x 10" (where a is the annual rate of events of M>O) as Line 42 seems to indicate? Consider adding the majorfaulls to this figure -would clearly show that the nearest red areas are associated with the San Andreas fault. 856 Figures 13-3, -4, -5 In the "Explanation", where is spelled "wehere" and buried is spelled burried". Please correct the spelling in all such figures, as the error is repeated. 857 Figure 13-6 Observe 2 colors for the 0.1* grid; however only one color (yellow) shown in legend 858 Figure 13-8 Notes state "Figure modified by Hardebeck, 2012: Legend states From Hardebeck, 2011" If the distinction is intentional and necessary, please add some clarification. If both references are to the same content, please make consistent. 859 Figure 13-9 The figure has PE as a site. whereas the Abbreviations: lists it as PB for Point Estero. Please correct the abbreviations to PE so that they are consistent. 860 Figure 13-11 Cites PG&E (2014). Is this 2014x. 2014y or 2014#??? 861 Figure 13-12 No apparent dip symbols appear to be used in the figure. Either make these larger/clearer or delete reference to them in the "Geologic Symbols" explanation. 862 Figure 13-13 Is it reasonable to have virtual faults that cross the Hosgri fault zone? APPENDIX -Earthquake Catalog 863 Line 28-29 Please consider whether there is actual support for the claim of "better-quality relocations than other available methods "Inserting this claim does not appear to add any useful information. and an option would be to delete the comparative statement and instead to state what specific attributes tomoDD provides that proved important to the outcome. 864 Lines 104-108 States that focal mechanisms were assigned a quality rating of A through C, but the lower-quality D rating was introduced. It would be clearer to state that they were assigned a quality rating of A through D, and then qualify the various ratinas. 865 Lines 143-147 These two sentences sound contradictory, i.e. there is "no material difference," yet there is a "difference of note." Please reword to avoid the appearance of inconsistency. Given the differences in locations, what was done? Either state the decision here or point to where it is discussed in the report. 866 Line 161 Refers to attachment X-3. but this was not provided. Same with attachment X-4 on line 173. 867 Citations PG&E These are electronic files provided to S. Thompson, but where are they 2014a and 2014b now? If someone wants to look at these files, how would they acquire them? Is there a URL that can be referenced? 868 Figs. X-1. X-3, and X-The explanations of these figures have the same spelling errors noted in 4 figs. 13.3, 13.4 and 13.5. APPENDIX H -Final SSC Model Hazard Input Document (HID) 869 Line tO Model-building is restricted to the Tl Team. Suggest changing to "to implement" the SSC model. 870 Line 25 Are areal sources and areal source zones the same thing? Suggest consistent use. 871 Line 30 Source-site? Source to site would be clearer. 872 Line 104 Table H.2-4 Rupture sources for Hosgri Table H.2-4 lists 7 sources (all three FGMs); 7 however, in Table H.2-6 there are 8 rupture sources for the Hosgri 873 Line 130 Should 7 ruptures be 8 ruptures? 874 Line 184 Please add the missing parenthesis at the end of the sentence. 875 Line 189 Why are some "sub" rupture in italics? 876 Table H.2-15 Standard deviation is zero?? Please clarify (e.g .. would it be more appropriate to say "n/a", as is done for truncation factor on the next line). 877 Line 246 Figure H-7. Might consider changing figure so it parallels text (a) maximum magnitude (bl Y-C characteristic (c) exponential (d) WAACY 878 Line 288 Delete "is" between "term" and "in for clarity. 879 Line 299 Table H.2-Why is OV-09 linked and Characteristic-why is it not Category B? 22. (LP+FS+FN+ON+OF) Please check other tables with linked faults H.2-24, H.2-26 880 Line 399 Table H.6-1 has NE and SW dipping reverse faults; logic tree Figure H-13 has N or NE and S and SW for the reverse faults -please make consistent. APPENDIX S-Workshop Summaries 881 Line 21 "A GMC model -"A" should be lower case 882 Line 24 Change "are" to "is as the verb refers to "Each workshop presentation" 883 Line 34 Consider spelling out RE at first usage in the appendix. 884 Line 53 You should not leave the reader with the impression that the master list of data collection activities coming from the workshop was, in fact, funded. 885 Line 56 Delete "but." 886 Line 56 Insert "are" after "presentations" for clarity 887 Line 101 Typically, the term "hazard" is used to specify the annual frequency of exceedance (y-axis of the hazard curve), rather than the ground motion (x-axis of the hazard curve) for a given AFE. Please clarify if this is the way that "hazard" is used here and subsequently when talking about percent contribution to the hazard (ie. is it the AFE or the ground motion at a given AFE?) 888 Lines 107-108 "none of the more distant faults contributes >1% to hazard ... " Is this per fault? In which case, because there are a lot of faults, could sum to significant hazard, or does this mean that these distant faults cumulatively amount to < 1 % of total hazard? Please clarify. 889 Line 113 Delete 2nd "that." 890 Line 113 The tornado diagrams actually show the sensitivity to hazard uncertainty, rather than to hazard itself. Suggest stating that they show the range in hazard results for the range in values of an input parameter in the logic tree. Thus, they show how much uncertainty in a parameter leads to uncertainty in the hazard result. If no uncertainty is included for a given oarameter, it shows no contribution to hazard uncertaintv. 891 Line t14 Delete the extra "that" 892 Line 186 Insert "USGS" in front of "."CRADA 893 Lines 261-271 Change all "Mr. Thatcher" citations to "Dr. Thatcher" -use is inconsistent here. 894 Line 283 Insert "for" after "rotation" for clarity 895 Line 329 "Rate" should be singular (?) 896 Lines 330-333 Is the maximum unaccounted for plate motion parallel or normal to the SAF? Please clarify. 897 Line 442 Check spelling of "Mohorovic." 898 Line 469 Please change "daps lo "gaps." 899 Line 500 Heave is not associated wilh the presence of a shallow/hard bottom -rather it is related to sea slate 900 Line 523 Insert "depth -so it reads "10 lo 15 km depth." 901 Line 567 "Investigations is lower case 902 Line 637 Should PPRP comments and Tl team responses be inserted here for Workshop #1 and likewise forWS#2 and WS#3? If not, then please point the reader to where they can be found. 903 Line 672 Consider deleting first "sensitivity." 904 Lines 822-824 Did Hamilton conclude or present this or is this inferred by the relationships he reported -if the latter might want to consider deleting. 905 Line 889 Clark reference? 906 Line 981 Replace "or with "to" 907 Line 988 In the near "shore," i.e., add "shore" 908 Lines 1077-1078 This might be stated more accurately as incorporating the additional uncertainty that would result from considering non-Poissonian temporal models, such as a renewal model. 909 Line 1116 Replace "N." with "Dr." 910 Line1131 Should PPRP comments and Tl Team responses for WS#2 go here? 911 Line 1225 Insert "then" -so it reads "then replaced." 912 Lines 1259, 1262, "Mr. Abrahamson" should probably be replaced by "Mr. AbramsonWard". 1277 Please check and correct if necessary. 913 Line 1289 Spell out "HN" ("horizontal to vertical") for clarity 914 Line 1290, 1291 Replace "Mr." with "Dr." 915 Line 1291 'These data yield". Actually, these are not data, but rather, interpretations. 916 Line 1312 Please replace "frequency" with "function" to reflect the correct interpretation of "CDF ." 917 Line 1385 "and is it ready ... " would read more clearly if written "and questions whether it is ready ... " 918 Line 1393 Replace "The" with "the" Also add period at end of sentence. Check the other PPRP sentences like this one as they also are missina periods at lhe end of the sentence. 919 Line 1400 Replace "generals" with "general." 920 Line 1608 Replace period with a question mark. APPENDIX Y -Data Summary and Geospatial Databases 921 Line 3 Data is plural, so change "was" to "were" 922 Line 40 Insert "the" between "as" and "Shoreline" 923 Page Y-8 Replace "maps" with map Folder name .. \Geographic_feature s 924 Page Y-20 (198") year? Folder name .. \other_ data\Diver _g eology Comment Location in Text Number 925 926 927 Lines 68-71 928 Line 81 929 Line 95 930 Line 99 931 Lines 101-103 932 Lines 107-108 933 Lines 110-1t1 PPRP Comment Response Table Installment #5 PPRP Comment CHAPTER 14-Hazard Sensitivity General comment: at several locations, only a discussion is given of what the sensitivity analyses show. More discussion is needed of these results occur. particularly as related to the particular elements of the SSC model. Otherwise, the reader is left to ponder and, given the various assumptions that were used to construct the sensitivity cases, may question whether the result is credible. General comment: Figure captions (or "notes" for the PG&E template) are very much needed for this chapter. Without them, the reader is forced to flip back and forth between the figure and the text in order to gain an understanding of the important messages being portrayed. The captions should draw the basic conclusions-or "take-aways-for each figure. It is suggested that this sentence be the topic sentence for the chapter. Consider putting the sentence from Lines 109-111 at the end of this section. Please replace "was" with "were". It is suggested that a description be given of what the tornado plots show (relative contributions to hazard uncertainty) and why they are called tornado plots (largest contributors to uncertainty are placed at the top of the diagram) The explanation of the construction of the tornado plots is given more precisely and clearly here than has been customary (thanks!). But a corollary of the description (specifically, of the normalization) seems to be that the values on a given line of a tornado plot (weighted by their branch weights) should sum to unity. Visually, that appears to be at least roughly true in most cases. But there are exceptions, e.g .. "IHEB Areal" in Figures 14-7, 14-8. "synchronous GM" in Figure 14-9, 14-10, "full characteristic" in Figures 14-11, 14-12, "magnitude PDF in Figure 14-12. If this is a misunderstanding, please clarify (e.g., perhaps it is mistaken to identify each line of a tornado plot with a node of the logic tree?) If this is correct. please refine the explanation of the tornado plots to accommodate the apparent exceptions to the current definition What are the "some cases" and please explain why they provide a value that is not in the logic tree. Does this mean that the conclusion drawn from the sensitivity analyses are also "not representative"? Perhaps it would be more accurate to say that the levels or amplitudes of ground motions may not be indicative of the final hazard results that are based on the inclusion of the full SWUS GMCmodel. Summary of Revisions to Report 934 Line 119 The figures and text refer variously to "annual frequency of exceedance (AFE), annual exceedance probability (AEP). and annual exceedance of probability." Please make them consistent throughout figures and text. 935 Line 121, Figure 14-There is actually a visible difference in hazard in Figure 14-1a at AFEs 1a greater than 10-4. Is there a reason that it is not noted here? If it is not significant, please so state. 936 Line 125 Please discuss the reasons for the differences in hazard level between the 2015 SSC and 2011 Shoreline models. In particular, why has hazard dropped systematically for the low ground motion levels, and increased systematically (at least in the 05 Hz case) at high ground motion levels? 937 Lines 133-136 It might help the reader by stating something like: For example, as shown in Figure 14-1a. the mean AEP associated with at 5 Hz spectral acceleration of 1 g is about 10-3. 938 Line 154 Replace "past" with "previous" 939 Line 158 An explanation for the contribution at higher frequencies made by the IHEB source zone would be helpful to the reader. 940 Line 163-165 Please compare the relative hazard from the Local areal source zone with the corresponding result from the 2011 Shoreline model and discuss possible explanations for any differences. 941 Lines 165-167 Any explanation why the SA contributes at the lower ground motions? It is likely related to the relatively high rate of occurrence of large earthquakes on the SA, but the great distance lowers the likelihood of lamer around motions. 942 Lines 182-185 Consider noting that such an observation is not unusual for site-specific hazard results. 943 Line 188 Please make reference to the specific section of the report that describes these logic tree branches and weights. 944 Line 192 Please explain why this simplifying assumption is made (these are the highest weighted FGMs?) 945 Line 200 Please explain why these AEPs are used for the display. 946 Lines 205 and 231 The weights on Line 231 give the appearance of being rounded representations of the weights on Line 205. If this is so, please clarify why one case was rounded and the other not. And, in any event, please clarify why the weights on Line 205 are expressed to such high precision while those on 231 are not. 947 Line 214 Replace "as with "and" 948 Lines 222-225 Please discuss the factors which may account for the stated differences in hazard from the three FGMs. 949 Line 224 Replace "unit" with "unity." 950 Line 227 Figure 14-8. Please provide figure captions and spell out abbreviations. Would be helpful if figures and figure captions were self explanatory. 951 Line 238 and 240 Replace "done" with "performed" 952 Line 239 This is not the "standard" for host zones any longer (e.g .. CEUS SSC model, Hanford PSHA. BC Hydro, etc.). Suggest deleting "in a more standard wav". 953 Lines 252-259 One might have speculated that smaller dip would decrease the average Rjb distance of DCPP from the virtual faults, and thereby would affect hazard measurably. Please consider whether some simple explanation can be provided for why this is not what is seen in the sensitivity analysis 954 Line 260 (general The section heading. figure captions. and most of the text, describe this comment on section as a section on time dependency. But the complex and splay 14.2.6) mechanism sensitivities are tucked away in this section too. Anyone scanning the chapter or figures for the latter sensitivities will likely not find them. Please consider making the full purpose of the section and its figures more transparent. 955 Lines 265-266 This is not necessarily "expected. The contribution to hazard uncertainty that the EPR branches make could be small if the range of EPR values was small-despite the dominant contribution of the Hosgri fault to the hazard. In other words. the large contribution of the Hosgri fault to the hazard means that the details of the characterization of that source are generally more important than other sources. But that does not mean that any given characteristic of that source will contribute significantly to the hazard. The EPR is one that does. 956 Lines 265-269 The sensitivity to Hosgri EPR appears to be significantly higher for 0.5 Hz than for 5.0 Hz. If this is a correct understanding, please comment on it and if possible suggest an explanation. 957 Lines 269-272 Interesting. in that the SAF is known to be at or near the end of the seismic cycle -why doesn't this have more of an effect? 958 Lines 282-283 Consider adding the phrase to the end of the sentence "due to the lack of including the secondary (or splay) rupture event" 959 Lines 285-287 Please discuss this a little further. Does this reflect that those ruptures are very infrequent in the model and therefore contribute very little to hazard to begin with? Or does it reflect the dominance of the primary rupture, such that the SSRS is little affected by the secondary rupture? Or both? 960 Lines 286-287 More accurately, the inclusion of the complex (or splay) ruptures or not does not have a significant contribution to the uncertainty in the total hazard. 961 Line 303 Replace "unit" with "unity" 962 Lines 312-316 Please provide an explanation for why this is the case. 963 Lines 331-335 Please provide an explanation for why this is the result 964 Line 343 Should "plots" be singular? 965 Lines 353-354 This explanation needs bolstering. Is it only the proximity of the Hosgri fault to the site? Both the slip rate and the EPR are directly tied to the recurrence rate. is that why they contribute most to the uncertainty in hazard? The Hosgri fault's slip rate is 1-2 orders of magnitude greater than any other nearby fault AND it is close to the site. Why not spell out why this result is expected, as this is the concluding punch of the chapter. From: To: Cc:

Subject:

Date: Attachments: Steve, Kevin Coppersmith Sieve Thompson; William Lettis sday@mail sdsu edu; ndriscoll@ucsd.edu; Thomas Rockwell Non-Mandatory Comments Saturday. February 28, 201 S 4:08:42 PM Non-mandatory Comments 1st Round.docx As I mentioned on the phone, after reviewing the revised draft report Chapters 1-7, 9, 11, and 12, we have identified non-mandatory comments that we are passing along to you. We believe that responding to these comments will improve the report and add clarity, but a formal response from the Tl Team is not required. We will forward our non-mandatory comments, if any, on the remaining chapters after completing our review. Best, Kevin Coppersmith Consulting, Inc. 2121 '.\/.California Blvd, Suite 290 Walnut Creek. CA 94596 P 925 F 925 932-3506 From: To:

Subject:

Date: Hi Steve, Kevin Coppersmich Sieve Thompson Non-Mandatory Comments Friday, March 6, 201 S 11: 10:38 AM As these come in to me from the Panel, I will pass them along to you. All very minor. Chapter 10: The only minor darity issue is on line 62 l -" ... then a rupture 10 km could occur on most of the source without passing X. R 1 = 70 km and ... " This would read more clearly if it read " ... then a rupture of 10 km length could occur ... " Thanks Kevin Coppersmith Consulting. Inc. 2121 N. California Blvd. Suite 290 Walnut Creek. CA 945% p 925 974-3335 F 925 932-3506 November 26, 2012 Mr. Kent Ferre, SE Project Manager Geosciences Department Pacific Gas and Electric Company San Francisco, CA 94177 Via email

Subject:

Participatory Peer Review Panel Report on Workshop #2, Diablo Canyon Seismic Source Characterization Workshop #2

Dear Kent,

This letter constitutes the report of the Participatory Peer Review Panel (PPRP) on Workshop No. 2 (WS2) of the Diablo Canyon Seismic Source Characterization (SSC). The workshop was held November 6 -8, 2012 in San Luis Obispo, California. Following guidance described in the Project Plan1 for the PPRP, and consistent with the expectations of the SSHAC Level 32 process, the PPRP participated in WS2 as observers in order to be informed and to review both procedural and technical aspects of the workshop. All four members of the PPRP (K. Coppersmith, S. Day, N. Driscoll, and T. Rockwell) attended WS2 and, collectively, the Panel observed all aspects of the workshop. The PPRP met each day with the Tl Lead, some Tl Team members, Project Manager, and the PG&E Geosciences Department manager. The purpose of these meetings was for the PPRP to provide their comments and suggestions for "mid-course corrections" to the ongoing workshop. As described in NUREG-2117, the PPRP is responsible for review of both the technical as well as the process aspects of the project. Therefore, the Panel's recommendations relate to certain aspects of the SSC technical evaluations as well as to ways that the process might be implemented to ensure that the goals of a SSHAC process are met. We offer these recommendations in the spirit of our common goal; a successful project that meets the objective of a SSHAC process that successfully captures the center. body, and range of technically defensible interpretations. The Panel's general observations as well as specific comments and recommendations are provided for your consideration below. 1 Diablo Canyon SSC Model Update Using SSHAC Level 3 Methodology, Project Plan for the Diablo Canyon Seismic Source Characterization (SSC) Model Update. dated July 18. 2012. 2 NUREG-2117, 2012, Practical Implementation Guidelines for SSHAC Level 3 and 4 Hazard Studies, NUREG-2117, U.S. Nuclear Regulatory Commission, Office of Nuclear Regulatory Research. Washington, DC 20555-0001. DCPP SSC WS2 PPRP Letter 11-16-12 Page 1 General Observations Workshop #2 of a SSHAC Level 3 process is the second workshop of the evaluation phase of the study, during which the data, models, and methods of the larger technical community are evaluated. The focus is on data presented by resource experts and models and methods presented by proponent experts. After Workshop #2, the project will move into the integration phase, during which the preliminary SSC model will be constructed. The PPRP would like to congratulate the DCPP SSHAC SSC project team for a very informative and useful workshop. Workshop 2 was very successful and the PPRP acknowledges the great amount of work performed by the Tl Team organizing the workshop and preparing the participants. The proponent experts were charged with a series of questions that helped focus their presentations and provided continuity to the workshop. The speakers did an excellent job staying on task and addressing the questions posed by the Tl Team. The meeting was well-coordinated and sequenced with good time management. The interaction amongst the Tl Team was dynamic; the Tl Team did an excellent job probing the proponent experts to evaluate and understand the models presented. The Tl Team was responsive to the suggestions made each day by the PPRP to improve the workshop. A good example was the improvement in the end-of-the-day summary conducted each day by the Tl Lead. The Tl Team also employed a novel approach of inviting resource experts, many of whom gave short "pop-up" presentations during the discussion section that helped clarify issues and raised alternative hypotheses. This proved to be very effective and the Tl Team should be commended. In addition, the Tl team did an outstanding job outlining and enforcing the roles and responsibilities of the Workshop 2 participants. In summary, this was an excellent workshop and it adhered to the requirements outlined in NUREG-2117 for a SSHAC Workshop #2. Specific Comments and Recommendations 1. Project Schedule The PPRP recommends that a detailed schedule for all working meetings, Workshop 3, deliverables, and other key activities be updated and issued by project management in the form of an updated Project Plan. At Workshop 3, the PPRP plays an active role and the preliminary model will be presented. Accordingly, the PPRP requires sufficient time to review the data evaluation and integration process, as well as the details of the SSC model. For the process to be effective, documents that describe the evaluation and integration processes need to be provided to the PPRP in a timely fashion well in advance of the workshop. It is the Panel's understanding that the Tl Team is using data summary and data evaluation sheets to document the data, models, and methods that are being reviewed during the evaluation phase of the project. These data tables need to be completed by the Tl Team when the data are examined prior to the model building process. In addition to the data tables, the PPRP would like to request a copy of the DCPP SSC WS2 PPRP Letter 11-16-12 Page 2 Hazard Input Document (HID, see NUREG-2117, Section 4.7.2) and any other documents that will describe the preliminary SSC model. Up to the present time, the participation of the PPRP in working meetings has been limited due to budget constraints. However, as the project moves into the process of evaluating the extensive data being gathered, as well as into the model-building process, we request that at least one member of the PPRP participates as an observer in the working meetings throughout the model building process leading up to WS3. As discussed in NUREG-2117: "However, provided that the boundaries are maintained and the clear separation of reviewers and evaluators is respected, then one or more representatives of the PPRP may attend the working meetings of the evaluator experts as observers. This could bring benefits of providing information to the entire PPRP via the observer representative at an early stage regarding the manner in which the evaluation and integration processes are being conducted. Such information can assist the PPRP in their later reviews of the bases for the technical assessments and their review of the project conduct and documentation. This is particularly true in Level 3 studies in which technical challenges to various interpretations by evaluators occur in the working meetings, as well as in the workshops." (p. 50) Given the expected large numbers of assessments and possibly complex components to the preliminary SSC model, coupled with the active role that the PPRP will play at WS3, participation as observers will greatly assist the Panel in gaining a first-hand understanding of the technical bases that underpin the preliminary SSC model. 2. Strategy for Recurrence Models Assessment of the impact of using different recurrence models turns out to rank at the top of the tornado diagram in terms of hazard significance. The Tl team needs to develop a clear strategy on how to deal with non-Poissonian models in light of the fact that it is unlikely that well-resolved information on the slip rates and timing of past earthquakes on the fault zones will be available, which are critical to the hazard assessment at DCPP. Specifically, use of renewal models requires information on the recency and rate of activity of a specific fault and these types of data are not likely to be forthcoming in the time between now and when WS3 is conducted. The Tl team will therefore need to develop and defend a model with large uncertainties that may have significant impact on the hazard to DCPP. Alternatively, the Tl team may wish to reconsider the use of non-Poissonian models, as it is clear from long paleoseismic records in California that earthquake recurrence has demonstrably large coefficients of variations and there is not a clear benefit in moving away from the state-of-the-practice of using Poissonian recurrence distributions. 3. Strategy for Consideration of Research Projects The workshop provided an excellent opportunity for the Tl Team to understand the data, models, and methods that the larger technical community is using to characterize seismic sources in California. In most cases, the presentations and discussions involved research-oriented activities and initiatives (e.g., UCERF3) that are designed to (1) push DCPP SSC WS2 PPRP Letter 11-16-12 Page 3 the state of the art and (2) to provide input to regional seismic hazard studies. We suggest that the Tl Team develop a strategy for how they will evaluate these other efforts and what elements of those studies are applicable to the site-specific SSC model and PSHA at the Diablo Canyon site. For example, much of the discussion at the workshop surrounding the concept of segmentation resulted in the general agreement among the participants that the tool is best used when high-quality behavioral data along a fault can be gathered and analyzed. There is little prospect that such data can be gathered for the Hosgri fault, so a strategy will be needed for how the segmentation tool can be used, if at all, for the DCPP SSC model. Similarly, the UCERF3 Grand Inversion attempts to incorporate various types of fault-specific information for the major faults of California and to incorporate a wide variety of rupture scenarios within the constraints provided by issues such as moment and slip balancing. To what extent can the UCERF3 model provide reliable estimates of SSC parameters for the faults in the DCPP area? If the UCERF3 model is not judged to have sufficient resolution to provide direct information on the local faults, should the conceptual models embedded in the UCERF3 model be adopted locally for DCPP? (e.g., local moment balancing, soft segmentation points resulting from slip rate differences). Because the UCERF3 model is regional and has been designed to provide regional seismic hazard, should it be used at all as either a direct input or even to inform the DCPP SSC model? These are all issues that we suggest need to be included and considered in the development of an overall strategy for the SSC model. 4. Full Participation of All Members of the Tl Team At the workshop, four out of the five members of the Tl team were fully engaged in the discussions. All five members need to be fully engaged and up to speed on all issues related to the SSC model as any member may be called upon in WS3 to defend or explain aspects of the model. In other words, all five members need to take complete ownership of all aspects of the model. As noted in NUREG-2117: During the model-building process, the Tl Team may divide the work among subgroups to expedite the evaluation process. However, the full team should thoroughly review, understand, and endorse the decisions made by any subset of the team because the entire team will be expected to assume ownership of the final model. (p. 74) If not all team members possess the attributes required for participation on the Tl Team, the Tl Lead should consider replacing those members that do not. Time is short and all members will need to be fully engaged to make the deadlines laid out in the project plan. Given the nature of the evaluations that lie ahead for the Tl Team, it may be prudent to include a member with expertise in geophysics and seismology. 5. Strategy for Hazard Model Development The workshop did a very good job of reviewing relevant research on fault behavior. There is clearly a growing recognition that a multiplicity of rupture modes is possible on the regional fault system in California. For example, ruptures may link faults in a great number of ways. A rupture may nucleate on one fault and transfer to other faults, even to faults of differing senses of slip. Critical points on faults (e.g., fault intersections and DCPP SSC WS2 PPRP Letter 11-16-12 Page 4 splays, stepovers, etc.) may sometimes become rupture endpoints, sometimes not, with probabilities that are still poorly understood. The project is therefore faced with a number of challenges: (1) Research on rupture modes such as that being conducted under UCERF-3 is at a regional scale, and only indirectly informs model building at the local scale relevant to the SSHAC study. (2) For the most part, the data required to apply those ideas are absent in the central coast region (e.g., reliable slip rates and timing of past ruptures). (3) That research is rapidly evolving. (4) It is possible that these complex multi-fault rupture models may raise significant interface issues when translated into ground motion models. (5) Given the very large number of potential linkages, end points, and segmentation models, a hazard model could quickly become unwieldy and incomprehensible. The PPRP therefore recommends that the Tl team develop, at the outset, a clear strategy for construction of a workable hazard model. Some elements that should be considered: ( 1) Hazard sensitivity may be an important element of that strategy. While all technically defensible models must be evaluated, it will probably be possible to eliminate some model complexities early in the evaluation process by documenting an absence of hazard significance. (2) The team needs to establish a clear cutoff on the consideration of emerging research results. (3) The strategy should consider potential ground motion interface issues. For example, ruptures that link faults with different senses of slip may raise substantial new problems when translated into ground motion modeling. 6. Data Tables All data that have been evaluated by the Tl Team should be documented in data tables such that the Team can represent the center, body, and range of technically defensible interpretations during the model building process. Accordingly, data summary and evaluation tables should to be completed when data are examined and evaluated. Evaluation entails a number of activities including identifying important technical issues and the ability of the data to address those issues, as well as evaluating the data in terms of their quality and relevance to the assessments being made. Integration is model building to arrive at a defensible expression of knowledge and uncertainty of the inputs to the model. giving due consideration to the available data. This includes the full expression of the model elements (logic-tree branches), their relative weights, and the range of credible uncertainties. Documentation of data evaluation and integration is one of the most important parts of the SSHAC process; it should be performed concurrently with model building. The PPRP needs timely access to this documentation throughout the model building process in order to perform independent evaluation. 7. Lexicon of Terms During the course of Workshop 2, it became clear to the PPRP that key proponent experts were using terminology that had a different meaning for different people. As an example, the term "fault segment" was used by one expert to imply that a section or sections of a fault always ruptures together. whereas others used the same term to represent a change in the style or rate of faulting, a change in fault geometry, or some other aspect of the fault as a way to describe different sections of a fault zone. This DCPP SSC WS2 PPRP Letter 11-16-12 Page 5 causes confusion among the project participants, as well as among outside observers, and could be easily corrected by development of a lexicon of key terms that are used in this study. The PPRP recommends that such a lexicon of definitions be developed for key terms that will be used in the models and reports completed for this project, and that this lexicon be distributed to the appropriate experts to assure common understanding of key issues. 8. Site-Specific SSC Model Acknowledging the excellent cross-section of SSC talent brought to the workshop from the larger community, the Panel notes that nearly all of the participants come from the research community and are involved in regional seismic hazard studies that are not intended to be used for site-specific use and certainly not for use in evaluating the seismic design of nuclear power plants at low annual frequencies of exceedance. Although many of the basic seismic source characterization issues are common to both regional and local PSHAs, there are unique issues that come into play for site-specific studies that the Tl Team will face, but could not be addressed by the participants at the workshop specifically. For example. detailed modeling of fault geometries in the vicinity of the plant site will be important and local constraints on potential models of ruptures that entail faults having different senses of slip may need to be considered. Practical ways of deciding upon the fault-specific selection of applicable magnitude frequency distributions, and decisions regarding appropriate ways of incorporating the epistemic uncertainty in recurrence behavior will need to be considered. These are issues that have been addressed to some extent by others who have developed site-specific SSC models for nuclear facilities. It is suggested that the Tl Team consider the models and methods developed by other resource experts having site-specific PSHA experience. That experience may provide the team with additional insights and practical approaches that have been used to address common problems. 9. Aleatory Approach to Segmentation The discussions of fault segmentation at the workshop provided a valuable range of viewpoints on the issue and served to highlight not only the differences in models, but also the potential approaches that the Tl Team might take as they move forward constructing their SSC model. It is clear to the Panel that the community has moved away from considering the alternative segments that might result from a given segmentation model as epistemic alternatives toward a more aleatory model that includes the occurrence of a wide range of rupture scenarios at their applicable relative frequency. For example, the presentation by Glenn Biasi and comments by Steve Wesnousky reinforce the notion that a very wide range of possibilities are observed for possible controls of rupture segments, but it is more fruitful to consider the relative fraction or frequency with which those controls might limit or extend the ruptures. We suggest that the Team consider moving toward this type of aleatory treatment of alternative rupture scenarios-one that might include a number of credible scenarios each with its relative frequency of occurrence. It is also suggested that the Team consider the rupture case histories discussed at the workshop relative to the specific rupture scenarios that might be included in the SSC DCPP SSC WS2 PPRP Letter 11-16-12 Page 6 model. For example, the Denali earthquake appears to have nucleated on a relatively small thrust fault, with rupture then propagating onto the main strike slip Denali fault. This event and others like it might serve as potential analogs for the relationship between the faults that appear to merge with the Hosgri fault. Likewise, the workshop highlighted the value that might come from considering the orientation of principal stresses relative to the orientation of faults as they change trend. There and other case histories could provide a basis for the consideration and selection of credible and defensible rupture scenarios for the SSC model. Please do not hesitate to contact me if you wish to discuss any of our observations, comments, or recommendations. If it would be helpful, we would be happy to schedule a conference call with the PPRP to explain and discuss any of our recommendations. Sincerely, DCPP SSC PPRP Copy: Kevin Coppersmith, Chair Stephen Day Neal Driscoll Tom Rockwell N. Abrahamson, PTI B. Lettis, SSC Tl Lead DCPP SSC WS2 PPRP Letter 11-16-12 Page 7 April 1, 2014 Mr. Kent Ferre, SE Project Manager Geosciences Department Pacific Gas and Electric Company San Francisco, CA 94177 Via email

Subject:

Participatory Peer Review Panel Report on Workshop #3, Diab/o Canyon Seismic Source Characterization Workshop #3

Dear Mr. Ferre. This letter constitutes the report of the Participatory Peer Review Panel (PPRP) on Workshop No. 3 (WS3) of the Diablo Canyon Seismic Source Characterization (SSC). The workshop was held March 25 -27,

2014 in San Luis Obispo, California. Following guidance described in the Project Plan 1 for the PPRP, and consistent with the expectations of the SSHAC Level 3 process2, the PPRP participated in WS3 as active participants in order to be informed and to review both procedural and technical aspects of the workshop. All four members of the PPRP (K. Coppersmith, S. Day, N. Driscoll, and T. Rockwell) attended WS3 and, collectively, the Panel observed all aspects of the workshop. The PPRP met each day with the Tl Leads, Project Manager, and the PG&E Geosciences Department manager. The purpose of these meetings was for the PPRP to provide their comments and suggestions for "mid-course corrections" to the ongoing workshop. As described in NUREG-2117, the PPRP is responsible for review of both the technical as well as the process aspects of the project. Therefore, the Panel's recommendations relate to certain aspects of the SSC technical evaluations as well as to ways that the process might be implemented to ensure that the goals of a SSHAC process are met. We offer these recommendations in the spirit of our common goal; a successful project that meets the objective of a SSHAC process by capturing the center, body, and range of the technically defensible interpretations (CBR of the TDI). The Panel's general observations as well as specific comments and recommendations are provided for your consideration below. 1 Diablo Canyon SSC Model Update Using SSHAC Level 3 Methodology, Project Plan tor the Diablo Canyon Seismic Source Characterization (SSC) Model Update, dated July 18, 2012. 2 NUREG-2117, 2012, Practical Implementation Guidelines tor SSHAC Level 3 and 4 Hazard Studies, NUREG-2117, U.S. Nuclear Regulatory Commission, Office of Nuclear Regulatory Research, Washington. DC 20555-0001. DCPP SSC WS3 PPRP Letter 04-01-14 Page 1 General Observations We would like to thank and congratulate the SSC Tl Team for a successful workshop. It was clear that much work was done prior to and during the workshop to cover the entire SSC model, its detailed implementation, and its technical justification. We also congratulate the PG&E team for making all of the logistical arrangements to ensure a smoothly run workshop. Specific Comments and Recommendations 1 . SSHAC Level 3 Process The goal of Workshop #3 within a SSHAC Level 3 process, as described in NUREG-2117, is to provide the Tl T earn with feedback in two forms: 1) hazard sensitivity analyses that provide insights into the most significant parts of the preliminary SSC model, and 2) feedback from the PPRP regarding the technical support for the model and the degree to which the model captures the CBR of the TDI. Further, NUREG-2117 prescribes the specific roles that various participants should assume during the course of WS3. For example, all members of the Tl Team are expected to participate in the presentation, discussion, and technical justification for the preliminary SSC model. We were pleased to see that this was certainly the case and this led to thought-provoking discussions and insights into details of the SSC model components, as perceived by various Team members. At WS3 the PPRP is free to question members of the Tl Team regarding details of the SSC model and the technical justification for model elements and the treatment of uncertainties. In this regard, the Tl Team encouraged active PPRP participation and was responsive to the questions posed by the Panel. For example, the Team responded to the Panel's request for changes to the workshop agenda, which allowed additional time to discuss the approach to recurrence modeling. Also, in many cases, the Team positively considered the comments posed by the Panel and will use that information during the finalization of the SSC model. Other aspects of the SSHAC Level 3 process were appropriately conducted. Training in the proper roles of the workshop participants was performed daily, and those roles were enforced. For example, the role of observers was identified throughout the workshop and adequate time was provided for observers to comment on the proceedings daily. An additional bonus, for which the PG&E team should be congratulated, was the organization of a special session at the end of each day to allow the general public to ask questions related to the scientific issues surrounding earthquake hazard analysis. Typically, WS3 within a SSHAC Level 3 project occurs after the completion of the evaluation phase of the work such that proponent and resource experts are not present. An unusual aspect of this project is that data collection activities associated with AB 1632 are ongoing and the PSHA project must consider the results of those activities. Accordingly, PEs and REs were present and participated in the workshop to report their findings. However, the Tl Team was careful to define their role in the workshop and to DCPP SSC WS3 PPRP Letter 04-01-14 Page 2 make it clear how the Team would be considering the results of those studies in the future. The preliminary SSC model was not complete at the time that hazard calculations and sensitivity analyses were conducted for the workshop. However, the PPRP concludes that a sufficient framework, and components of the model had been completed to provide a significant amount of useful feedback to the Team to assist them with the completion of the integration phase of the work. In order for the work to be completed according to the schedule, it is recognized that a significant amount of work will need to done-in a properly prioritized manner-to arrive at a final SSC model. Prior to that time, the Panel would like to continue to review the development of the model prior to the review of the draft PSHA report. Suggestions for the elements of that review are described below under "SSC products for PPRP review." Also, the impact on the schedule will be important and we discuss this below in "Need for PSHA Schedule. 2. Need for PSHA Schedule Given that the preliminary SSC model is not yet complete, due primarily to the need to finish the ongoing data collection program, we anticipate the need to carefully schedule and prioritize the effort to first complete the preliminary SSC model, obtain additional SSC products and hazard sensitivity results (see below), finalize the SSC model, and document the PSHA report. Specifically, the elements of the schedule that we would like to see on the calendar are the following:

• Completion of the preliminary SSC model
• Delivery of the preliminary SSC model Hazard Input Document (HID) to the PPRP
• Finalization of the SSC model
• Briefing with the PPRP to review the final SSC model
• Delivery of the Draft PSHA report to the PPRP for review
• Review of the Draft PSHA report by the PPRP (minimum six weeks required)
• Delivery of PPRP comments to the Tl Team
• Delivery of Draft Final PSHA report to PPRP for final review
• Delivery of PPRP Closure Letter to PG&E 3. SSC Products for PPRP Review In order for the Panel to have a full understanding of the SSC model, we would like to request the following products be provided. We understand that all of these products are already part of the planning and deliverables anticipated by the project, but we would like to emphasize their importance to the Panel by listing them below:
• Recurrence curves for rupture sources, particularly for the Hosgri fault
• Implementation of the WAACY model for linked ruptures (Mmax ruptures); how do you arrive at b-tail and tail offset DCPP SSC WS3 PPRP Letter 04-01-14 Page 3
• Approach to the use of non-Poisson recurrence models, the logic tree distribution of equivalent Poisson rates, and their impact on hazard and uncertainty contribution
• Impact of logic tree branches for Mchar and Mmax on hazard
• Impact of categorization of rupture sources as either Mmax and Mchar
• Discussion of what is aleatory and what is epistemic (e.g., Mmax logic tree, versus aleatory rupture sources)
• Hazard sensitivity for all of the above, including running the Shoreline Fault Report model with the new Hosgri rates 4. Tl Team Action Items The Tl team did an excellent job discussing/summarizing each day's results as well as developing a list of action items required to finalize the SSC model. The PPRP endorses such an approach. Here, we review the Tl team's action items according to an overarching theme, not priority. The PPRP is NOT directing the Tl team with regard to which action item or scope of work needs to be completed; such decisions are the responsibility of the Tl team as they finalize the SSC model. It should be noted that some of the actions identified by the Tl Team relate to immediate actions that are needed to finalize the SSC model, other actions relate to documentation that will be provided in the PSHA report. We include both types of actions in our comments below. a. Documentation of Piercing Points. Documentation of piercing points for offshore fault systems and age models is required. Specifically, the Tl team should explain how the piercing points are used to constrain slip distribution along the fault with the full range of interpretations reported. When multiple piercing points yield different offsets and imply different rates, the Tl team should document how the geologic slip rate distribution is characterized along the fault. b. Document Use of ONSIP Results. After the SSC model has been finalized, the Tl Team should document how or if new ONshore Seismic Investigation Project (ONSIP) results are used to constrain fault geometry and locations in the Irish Hills. For example, will the dip of the Los Osos and San Luis Bay faults in the OV, SW, and NE tectonic models be constrained by the ONSIP data? c. Document Definitions of Styles of Faulting. The three proposed tectonic models (OV, SW, NE) entail a rather large range of rakes on some of the individual faults (e.g., the San Luis Bay and Los Osos faults). The style-of-faulting (SOF) categorization of a fault for purposes of applying GMPEs depends upon its rake. We recommend that the SSC Tl team coordinate with the GMC (SWUS) team to ensure that appropriate GMPE SOF classes are assigned to the faults, recognizing the SOF assignment for a given fault may vary depending upon which tectonic model it is participating in. d. Carefully document/compare with UCERF3. The PPRP agrees with the Tl team's action item to compare the slip rate models, linked rupture models and rupture participation rates to the corresponding UCERF3 results. The SSC model is based DCPP SSC WS3 PPRP Letter 04-01-14 Page4 on a more current data set for the local faults than is the UCERF3 model, so agreement is not necessarily to be expected. Rather, the objective should be to document the comparison, pointing out any important differences and explaining why they arise. e. Documentation of Slip Allocation and Budget. It is critical that there be complete documentation on how slip is allocated among the various rupture sources and various models to construct the final slip budget. The allocation of slip budget to various earthquakes in the final model will drive the ultimate shape/form of the MFDs, which are the basic input to the hazard model. f. Explain Differences in Hazard with that of the Shoreline Fault Report. It was clear during multiple/various presentations that the current assessment of hazard is consistently lower than that presented in the Shoreline Report, possibly based on updated information on fault slip rates. This is a significant feedback issue and will need to be understood prior to finalization of the SSC model, and will ultimately need to be completely documented. g. Age Model in the Offshore. The PPRP was pleased to see a coherent age model presented by various PEs and members of the Tl team for use in the assessment of slip rates for the offshore faults illuminated by the LESS studies. This represents an improvement over earlier presentations and indicates a maturation of the offshore age model that is now being applied in the assessment of slip rates. The PPRP has increased confidence that the final slip rates that will be assessed and completely documented by the Tl team in the final report will rely on a mature, defendable age model. h. Documentation of Hazard Sensitivity to Fault Models. The three primary fault models could represent different hazard levels at DCPP. It will be important to document the hazard sensitivity of these various models to establish whether one model represents a substantially higher hazard than others, and to be sure that all assumptions are well-founded and applicable uncertainties incorporated. Please do not hesitate to contact me if you wish to discuss any of our observations, comments, or recommendations. If it would be helpful, we would be happy to schedule a conference call with the PPRP to explain and discuss any of our recommendations. Sincerely, DCPP SSC PPRP Kevin Coppersmith, Chair Steven Day Neal Driscoll Thomas Rockwell DCPP SSC WS3 PPRP Letter 04-01-14 Page 5 Copy: N. Abrahamson, PTI W. Lettis, SSC Tl Lead DCPP SSC WS3 PPRP Letter 04-01-14 Page 6 Participatory Peer Review Panel (PPRP) Review of the Document: "SSHAC Level 3 Methodology, PG&E DCPP SSHAC Study DRAFT -Project Plan for Diablo Canyon Seismic Source and Ground Motion Characterization SSHAC Studies" Dated August 8, 2011 This document provides the PPRP's comments regarding the Project Plan for the DCPP SSHAC Level 3 PSHA. We have focused our comments on items that relate to the manner in which the study will be carried out and on clarifying the activities that will be conducted. We have not focused on editorial revisions that might be made to the document itself. Our comments are divided into General Comments and Specific Comments, given below. General Comments PPRP Participation. The SSHAC level 3 process permits a role for PPRP members beyond the formal workshops, i.e., involvement as observers at working meetings of the Tl groups. The draft project plan is silent on this additional involvement of the PPRP members. Rather than leaving this entirely to the initiative of the PPRP (as suggested at the Kickoff Meeting), perhaps there should be a mechanism for the project leadership and the PPRP to collaboratively identify opportunities for this broader PPRP participation and to add that to the Project Plan. Workshop plans. It is important that the workshops follow the SSHAC structure and numbering conventions more closely than is indicated in the current Project Plan draft, so that participants will have greater clarity as to their roles. In particular, Workshop 1 should be restructured to follow the SSHAC model and therefore focus on ( 1 ) identification of technical issues of highest significance to hazard. and (2) identification of available data and other relevant information. The current Workshop 1ab plan lacks this focus, since it includes proponent presentations and exploration of model alternatives (p.14 ). Workshop 1 should attempt to be inclusive with respect to data, i.e., should provide a thorough data review (including older data if they will used in the PSHA update) to ensure that all participants are "on the same page" prior to discussions of alternative models at subsequent workshops. To go beyond "data" in the narrow sense, to more broadly encompass relevant information, Workshop 1 should also include presentations on the simulation methodologies and their verification and validation. It also seems to us that it is appropriate to include presentations on relevant community models and products (e.g., updated Ground Motion Prediction Equations; regional seismic velocity and/or fault models, if relevant) and updates on ongoing data collection efforts that can be expected to provide relevant data within the life of the study (e.g., offshore seismic network deployment). If multiple workshops are required on these topics, it would be appropriate to designate them Workshop 1 a,b, etc. The subsequent workshops should be restructured to provide a clearer distinction between (1) those filling the SSHAC "Workshop 2" function of presenting alternative models and their technical bases, prior to development of preliminary models by the Tl teams, and (2) those filling the 'Workshop 3" function of presenting preliminary models and hazard calculations and receiving feedback. A clearer distinction is required because the participant roles are different in each case (for example, the PPRP plays an active role in the latter, but an observer role in the former). This would not preclude having multiple workshops of each type and accommodating multiple cycles of feedback, as deemed necessary. Specific Comments p. 1, 1st para.: It would help the reader to understand exactly what "update" means. The SSHAC NU REG (NRC, 2011) uses the term in a general way to mean any replacement, revision, or refinement to an existing PSHA. Based on comments at the Kick-off meeting, it appears that the intent of this study is to "replace" the previous PSHA. p. 2, 2nd para.: The sentence states that the DCPP study "will differ in several important aspects" from a traditional Level 3 study, but the three items identified are common to other similar studies and making a distinction is not necessary. For example. the PSHA, PVHA, and TSPA SSHAC studies for Yucca Mountain were all open to the public and attended by a variety of observers; nearly all hazard studies replace previous such studies and the SSHAC guidance says that assessment of hazard-significance is required for Workshop #1; and most hazard studies take advantage of an ongoing collection or data-analysis program that is conducted in parallel with the hazard study. Therefore, it is incorrect to state that these are important differences with other SSHAC studies; further, drawing such a distinction leaves the reader wondering what the significance of the differences means and whether the approach to be followed (said to be different from "a traditional Level 3 study") would be considered acceptable as a SSHAC Level 3 process. p. 3, 1st para.: Reference is made to a Figure 2, but it is not provided. p. 3, 2nd para.: Table 1 should be revised to reflect the actual time of the Kick-off meeting and any other changes that reflect the current schedule. p. 3, 3rd para.: Here and elsewhere, the NUREG should be referred to as NRC, 2011. Because the document is not a contractor report (i.e., NUREG/CR), it is NRC's intent for the document to represent the NRC staff's positions without attribution to specific authors within the NRC. Once the document is issued a NUREG number. it is suggested that the document identifier be used in the citation. Page 4, Paragraph 2, Last Sentence: I believe "transparent" should be added to the list of items that the seismic hazard study is expected to achieve. p. 5, 2nd para.: Somewhere in this section, describe the process for selecting the participants. What are the criteria and qualifications? Is past DCPP experience part of the consideration? For those participants with previous DCPP experience, indicate how the project leaders will ensure there is no bias or anchoring to previous interpretations and technical positions. For those with no SSHAC experience, how will they be provided with sufficient guidance to understand the essential steps and participant roles? p. 5, 4th para.: It is stated that the Tl Team "may have" a staff of experts, but the organizational chart shows an SSC Tl T earn Staff Support box, so the text should be consistent. It appears from the text that the Staff will not "own" the Tl Team's assessments, which would imply that they will not directly participate in the integration (model-building) process (e.g., identifying logic tree branches and assessing weights). Is this true? If so, that should be made explicit. p. 5, 4th para. (and elsewhere): As noted, NRC (2011) suggests that the term "ITC" be replaced by the two-step process of evaluation and integration, defined as:
• Evaluation: The consideration of the complete set of data, models, and methods proposed by the larger technical community that are relevant to the hazard analysis.
• Integration: Representing the center, body, and range of technically defensible interpretations in light of the evaluation process (i.e., informed by the assessment of existing data. models, and methods). It is therefore suggested that "ITC" and "the informed technical community" be removed throughout the text to help avoid confusion. The sentence in the paragraph should be revised to say: "As such, the Tl Team is responsible for ensuring: (1) that the various data. models, and methods proposed by the larger technical community and relevant to the hazard analysis are considered in the evaluation; and (2) that the final SSC and GMC models represent the center, body, and range of technically defensible interpretations." Page 5, Last Paragraph: To avoid any perception of bias. it should noted that the PTI and GMC Tl Lead is an employee (i.e., Norm Abrahamson) of the Project Sponsor (i.e., PG&E) but that the SSHAC process has sufficient checks and balances to avoid any conflict of interest (e.g., PPRP review of technical assessments and process). This discussion should be part of the suggested discussion regarding the criteria and process for selecting the project participants. p. 6, 2nd para.: Typically, members of the Tl Team are expected to play the role of evaluator experts and well as integrators (see Section 3.6.3 of NRC, 2011 ). As written, it appears that the evaluator experts will be "identified as needed on the project" and are somehow external to the Tl Team. It is suggested that responsibilities of the Tl Team be to assume the role of evaluator experts. p. 7, 3rd para.: There is quite a bit of discussion about observers in NRC (2011 ), including sponsors, regulators. public representatives, PPRP, etc., so reference should be made to that guidance. p. 7, 3rd para.: Consider allowing for observers to make statements or ask questions at the end of each day of the workshop; having to wait until the end of a multi-day workshop can be frustrating.

p. 9, 1st para.: Take care to not raise the issue of PPRP participation in the evaluation and integration process (see also 1st paragraph on p. 10) by saying that the "PPRP is involved" in the evaluation or integration process. The PPRP reviews those processes and maintains its independence throughout. Page 9, Paragraph 2: With respect to item (b), will the hazard sensitivity analyses be conduct for only the "exceedance frequencies of interest" or for all frequencies? Page 9, Paragraph 3: Shouldn't a statement similar to that at the bottom of Paragraph 4 be added to this paragraph? The sentence would read something like "The final logic tree (GMC V5) will be developed based on the feedback from the Resource experts and PPRP members." Page 9, Paragraph 4, Sentence 1: Later in the text there is no mention of an iterative GMC V3. V3 is described as being the final version. Page 10, Paragraphs 1 & 2, Last Sentence: Suggest that "working meetings" be included in the list of meetings in which the PPRP has an opportunity of being informed of project developments. p. 1 O, 4th para.: Is the Figure 2 cited that same as Table 1? Page 11, Paragraph 1, Sentence 2: The project plan is generally written in third person, but in this sentence and several other sentences throughout the text. the first person is used. The text should be consistently written in the third person. p. 11. 2nd para.: It is stated that. "The actual databases formed for the GMC and SSC studies will become part of the SSHAC documentation and will be made publically available." Is this actually what is intended? How will the data be made available? Are there plans for dealing with copyright issues, proprietary data, ownership releases, etc.? Is there a plan for a public portal to retrieve the data (e.g., website)? This was a major activity on the CELIS SSC project and deserves additional discussion in this Project Plan. Page 11, Paragraph 2, Middle: It is not clear whether the reference to "numerical [ground motion] simulations" is with respect to the NGA-west2 project or other ground motion simulations that will be conducted by others. p. 12, 3rd para.: There is no discussion of what the data evaluation process will entail. At the kick-off meeting, there was discussion about the use of Data Summary and Data Evaluation tables for this process, as in the CELIS SSC project. Any differences in the data evaluation process for SSC and GMC should be identified. Page 13, Task 4, Sentence 2: It appears from this sentence that only new data, analyses, and interpretations since the last update of the LTSP seismic hazard program are going to be presented at SSHAC Workshop 1. Since previous data, analyses, and interpretations were not conducted under a SSHAC Level 3 program, any previous data, analyses, and interpretations that will be used in the SSC and GMC logic trees will need to be vetted through the SSHAC Level 3 process in order to establish data needs and allow review by the PPRP and new members of the Tl Teams. p. 13, P' para. (and see General Comments): The title and description of WS1 blurs the lines between the typical WS1 and WS2 for a SSHAC Level 3 process (see descriptions in NRC, 2011 ). It is suggested that the descriptions be revised to more clearly define the purpose and activities of WS1, 2, and 3 to conform with NRC (2011 ). If additional workshops are needed, they can be tied to WS1, 2, and 3 by citing a, b, c, etc. Page 15, Task 4d, Bullet 3: GMC Model V1 should also be evaluated through a sensitivity analysis Page 15, Task 5, Sentence 3: Only "new information" is referred to as being presented at SSHAC Workshops 1 a and 1 b. Any old information that will be used should also be presented. Page 15, Task 5, Last Sentence: This is where it gets confusing regarding which version of the GMC logic tree model is being used. It is not clear whether the GMC logic tree model is being evaluated at the same time as the SSC logic tree models (i.e., there is no mention of the GMC model). Is only the SSC model being evaluated and, if so, why? Page 16, Task Sb, SSC, Bullet 1: There is a question that needs to be resolved for the final version of the Project Plan. Page 16, Task 6: Title and text refers to GMC Model V3 as the final model, whereas previously it was stated that V4 would be the final version. Page 18, Task 7: Under item (1 ), the GMC model should be included along with the SSC model? p. 19. 3rd para.: There is no discussion about developing a Draft Report. I assume that the project will want to received comments from the PPRP on a Draft prior to developing its final comments. Page 20, Paragraph 1: NRC (2011) should be referenced along with Budnitz et al. (1997). p. 23: Please ensure that the dates and topics in this table are consistent with those given in the excel schedule (which should also be made part of the Project Plan). Also, there are random comments in the table that presumably should be deleted.

Page 23: (a) The note identified by the"**" needs to be done. (b) The list needs to be formatted in a consistent manner. (c) The PTI, Tl staff, and Hazard Analyst should also be listed as attendees at all of the workshops. Page 24: The note identified by the"***" needs to be done. Page 25, Workshop 28: Under the list of Attendees, what does "Down" mean? Page 26, Workshop 3: The "SSC & GMC" before "Workshop 3" should be deleted. Pages 27 & 28: Figures 1 and 2 are missing. February 13, 2012 Kevin Coppersmith Chair DCPP PPRP

Subject:

Response to PPRP comments on Workshop #1

Dear Dr. Coppersmith:

Thank you for the comments, dated December 13, 201 l, on Workshop #1 .Our responses to the comments and recommendations are given below. Norm Abrahamson Chief Engineering Seismologist Pacific Gas & Electric Company Response to Comments 1. Update Project Plan The Panel recommends several steps that should be taken by the project and then documented in an update to the Project Plan. These are summarized here: -The Project Plan should clar((v the role deterministic analyses in the sensitivity analyses, in defining the sign(f'icant issues, and ultimately in identffyi11g the data compilation a11d data collectio11 activities. Response: As noted at the workshop, both deterministic and probabilistic approaches will be used in the seismic hazard update for DCPP. This is consistent with the current License Amendment Request that was submitted to the NRC. We agree that the use of the deterministic method in defining hazard sensitive issues needs to be defined. The project plan will be updated to clarify the role of the deterministic analysis. The revised project plan will be submitted to the PPRP by March 31, 2012. -The schedule.for WS2 and working meetings between now and WS2 should he estahlished as soon as possible to ensure that all participants have adequate opportunity to work these dates into their schedules. For example, in discussions with the TI Leads, it was stated that WS2 would not occur in June but rather in November 2012, but that the June date would be held for a working meeting of some sort. We suggest that the June working meeting include the emire PPRP as observers so that an entire year does not pass between now and the next inte1.face with the project. Response: The schedule for WS2 and the working meetings have been set. Workshop #2 is planned for Nov 5-9 (starting Monday afternoon and finishing Friday noon}. A list of working meeting dates was sent to the PPRP in January. They are repeated below: GMC Working Meetings in 2012 March 19 (1-3 pm at PG&E) May 30 (1-3 pm at PG&E) June 19-20 (9-5 pm at PG&E) July 18 (1-3 pm at PG&E) October 8 (1-3 pm at PG&E) SSC Working Meetings in 2012 SSC TI Team Working Meeting 58 6 7 8 9 10 Date 01/11/2012 01125/2012 02/13/2012 03/12/2012 03128/2012 05/14/2012 Venue PG&E SFGO -CR 407 PG&E SFGO -CR 407 LCI -Walnut Creek PG&E SFGO -CR 407 LCI -Walnut Creek PG&E SFGO -CR 407 I I 06/ 19-06/21/2012 PG&E SFGO -CR 407 12 07/09/2012 LCI -Walnut Creek 13 08/13/2012 PG&E SFGO -CR 407 14 09/13/2012 LCI -Walnut Creek 15 10/11/2012 PG&E SFGO -CR 407 16 12/10/2012 LCI -Walnut Creek Workshop #2 Nov 5-9 at Embassy Suites, San Luis Obispo -The project should consider having a representative.from the SSC Tl Team attend GMC working meetings, and vice versa. Response: Agreed. This will be done for future working meetings. -One or more represenlativesfrom the PPRP should he invited lo each f?{fhe working meetings to al/end as ohservers. For this to happen, the PPRP must he in.fhrmed <?[the meetings asfar in advance as possihle. Response: The PPRP is invited to send a member to any of the working meetings. It is up to the PPRP to select which working meetings to attend and which PPRP member should attend. The schedule of working meetings is provided above. We will inform the PPRP of the agenda for each working meeting prior to the meeting. -We recommend that parallel sessions not he used in.future workshops. hut that the SSC and GMC session he held The SSC and GMC participants can attend their own workshop and depart. but the Tl Leads and the PPRP should attend both sessions. Response: Agreed. Workshop #2 will not have parallel sessions. We have extended the workshop to start Monday afternoon and end Friday at noon to allow for the parallel sessions. The relationship between the Tl Staff and the Tl Team need<.; to he clarffled. What is the distinction? Who will he building the models during the integration part <?f the pr<?ject? Response: The Tl team members have ownership of the SSC and GMC logic trees. The Tl team staff provide technical support for the Tl team and will participate in the discussions at the working meetings, but they do not have ownership of the final model. This will be clarified in the updated project plan to be submitted by March 31, 2012. 2. Workshop Attendance and Participation To ensure that the appropriate expertise is present.for workshop discussions, we recommend support.for all participants.for the entire duration q(their respective portion qf'the workshop (i.e., GMC or SSC). Thus, a proponent expert participating in WS2 would be provided support to attend not the day qf their presentation, hut also the remaining days o,ftheir respective portion o,f the workshop. Response: Agreed. The resource experts will be asked to attend the full workshop, with compensation provided for the additional days. 3. Summary at the end o,feach technical session Interaction between TI team and experts during workshop meetings is a key component C!fthe SSHAC Level 3 Process. To.foster more interaction. the PPRP recommends that a session summary he made at the end o,feach session hy the TI Lead with input.fi*om the entire TI Team and all attending experts. {fapplicahle, it is also recommended that prioritization of any potential future project activities (e.g., gathering new data, conducting new analyses) be part C!f the summary so that input.fl-om the TI Teams and workshop participants can be discussed and considered. Response: Agreed. At future workshops, an initial prioritization will be discussed during the workshop to gain from the resource/proponent experts views and to also avoid giving the impression that all the tasks discussed will be funded. 4. Inclusion or Exclusion l!f Interpretations It is important that the Tl Team communicate a clear and consistent policY,for the inclusion o,f SSC and GMC models. At least one statement during Workshop I posited that ff an interpretation cannot he rejected then it will be included in /w::,ard models. The PPRP notes that the SSHAC guidelines, as ampl(/ied by the draft NUREG on SSHAC Level 3 and 4 implementation, stipulate only that "technically defensible'* models be included, and we recommend holding strictly to this concept. Response: Agree. The project plan will be modified to make it clear that only technically defensible interpretations will be included 5. Participation o,f TI Team Members The TI team members are. without exception. highly capable sciemists and engineers who, together, bring the expertise.for a success.fl.ti prl!ject. Notab(v. though. their level is roughly bimodal. with some members having two to three decades o,f experience in seismic hazard studies, and the rest being at much earlier career stages. The involvement o,f the latter cohort is a very positive developmem that we commend. However, this circumstance does place an added responsibility upon the TI leads. It will be incumbent upon them to elicit the .fi1ll and independent voicing C!l views by all team members that is necessary to provide high that no individual cognitive biases dominate the process. Response: As noted, there is a wide range of experience in the Tl teams and one of the goals of this project is to develop younger people that can lead Tl teams in the future. We will encourage the younger members of the Tl team to participate fully in the discussions at both the workshops and the working meetings and to question the recommendations of the more senior Tl team members. The more senior members will actively work to engage the younger members in the discussions and evaluation process. This will be a continuing challenge for the project and should be carefully watched by the PPRP. 6. Data Needs or Gaps Particularly in the SSC element the project, a large number data gaps and data needs were identified, along with a host studies that could be conducted to address data needs. As noted by the SSC TI Lead, the project resources will not he sidficient to conduct all C?f'the studies ident(fied. When identfjjJing additional data needs or data gaps to address sign(ficant issues or uncertainties, we recommend that this he an exhaustive process that allows.for prioritization and decision-making. Speqfically. it is recommended that the process include a.full inventory andjust!flc:ation gaps, realistic costsfor acquiring new data, and design plans.for data acquisition. Furthermore, in areas where data already exist, an explanation should he given for why the existing data fail to address sign(ficant issues and uncertainties. Response: Agreed. The justification for the new studies will be made and documented. In particular, we will continue to ask the question "what are the short-comings of the existing data and what are the uncertainties that are caused by the short-comings?" 7. Data Jnve11t01y and Documemation There is a need to establish a process for identffying those data that were considered and used in each model element for the project. As noted in NRC (2011): It is important to document and inventmy all data that were considered in the course of the project including those data that were not used. For those data that were relied upon, it is important to also document the manner in which those data were used. "Spec(fically, there needs to be complete documentation process of data evaluation, and which data were considered, and ultimately used to construct each element the.final seismic hazard model. Response: Agreed. We plan to use the data table approach developed in the CEUS-SSC study to document which data were used and which were excluded. Data tables will be prepared for both the SSC and GMC. We will include an Attachment to the Project Plan that includes a description of the data evaluation and documentation process with an example of the Data Evaluation Table. 8. Interim documentation and review We recommend that key intermediate products he documented in writing and reviewed hy the PPRP. For example. the PPRP would welcome the opportunity to review.fi!lly documented data collection plans, which should include (1) the relationship efforts to reduction. and (2) the rationale.for their prioritization. Response: The rationale for the prioritization of data needs and descriptions of the planned studies will be provided to the PPRP for their comment.

9. Data Availability We recommend that all data acquired or used to develop a model or imerpretation he made publically available as soon as quality control is Such a policy will allow the public and the scient(fic community to acquire/review the data and develop alternative models in a timely manner. It will also make the SSHAC process accessible and tramparent. For example, during the course of the project, r£ferences used in developing models and interpretations could he collated into a master reference list and made available. Also, a PDF database for all references could he developed a11d made available to the TI Teams a11d StaJJ: as well as the PPRP. Response: We agree that there is value in making the data sets publically available as soon as the QA is completed. The decision regarding how the different data sets will be released has not been decided yet. Data collected under the AB1632 program may have different reporting requirements. Any PG&E data sets that are presented at workshops will be made publically available before the workshop. 10. Imerface issues The Diab lo Canyon SSHA C study has some characteristics that affect the scope required collaboration between the GMC and SSC teams. For example, the SSC team may have to consider logic-tree branches involving a range f?f"single-and multi-segment rupture models.for the Hosgrifault, the possibility Shoreline splay faulting, and a considerable range <?[scenarios.for the Los Ososfauft to accoum.for dip uncertainty. It is important that key scenarios be communicated to the GMC team at an early stage, in order to permit the latter to undertake an adequate integration of data and empirical and numerical models for those scenarios. As another example, the project makes sign(ficant use f?f"dynamic rupture modeling to address DCPP issues such asfault branching and hanging-wall ampl{fication. Dynamic modeling will create new SSCIGA1C inte1.face issues beyond those that customarily arise in kinematic modeling (for example, a critical component of the.fault branching problem is the orientation principal stresses, which are not required.for kinematic modeling). A third example relates to the scale of the seismic velocity and attenuation models, as high-resolution models may provide importam constraints for ground motion studies. While scale structure will be important.few SSC issues (e.g., seismotectonic studies). geologic variations on the scale afew kilometers or fess may carry information relevant to GMC (e.g.. i11formation on the crustal qualityfactor (Q) around the DCPP site that may heljJ to address the question: Could the high DCPP site kappa he due to a low-Q path? In order to ensure that these sorts of inteiface issues are adequately addressed and results communicated, we recommend that SSC working meetings be attended by some member(!l) the GMC group. and vice versa. Response: Agreed. l I. Comprehensive Simulation Validation Plan The GMC Tl team proposes extensive use f?f ground motion simulation, hoth kinematic and dynamic. to help characterize ground motion at DCPP, including the median motion.fl'om nearby/emits, the hanging wall q{fect, the directivity effects, and the near-:.fleldfling velocity pul<>e. Validation is a critical process to assure that a particular simulation method is sound and its results can he trustedfor use at DCPP. Validation o.lsimulation methodology was discussed at WS 1; however, the discussion focused mainly on the near-fault median motion. The PPRP recommends that a comprehensive validation plan and validation rules be established by the project that will cover the full set ojfeatures to be used in the project by the GMC TI Team. This validation plan should cover hoth the kinematic and dynamic modeling. Response:. We agree that the validation plan should cover both kinematic and dynamic modeling, but we do not agree that the validation should not be focused on the near-fault ground motions. These near-fault ground motions dominate the hazard. We do not want to be distracted by issues that may arise for distant earthquakes. For example, ground motions from large magnitude earthquakes at large distances may be dominated by wave propagation effects that are not significant for the hazard at DCPP. 12. Epistemic Uncertainty in Ground Motion Estimates It is important that the epistemic uncertainty in the ground motion estimates adequately represent the center, body, and range the defensible interpretations. Although the PPRP acknowledges the importance the empirical NGA ground motion prediction equations (GMPEs), it is critical that all relevant data and models, 11otjust the NGA models, he considered in developing the median, standard deviations, and epistemic distrihution o,j'ground motion estimates. This should include relevant ground motion data and GMPE'lfimn similar tectonic regions.fl*om around the world as well as ground motion simulations where empirical data and models are insuj.ficient in characterizing all of the representative earthquake scenarios, whether prohahilistically or defined, that will he proposed hy the SSC team. Response: Agreed. Applicable data, GMPEs, and simulation methods from other parts of the world will be considered in developing the range of ground motion models for DCPP.

January 16, 2013 Kevin Coppersmith Chair DCPP PPRP

Subject:

Response to PPRP comments on Workshop #2

Dear Dr. Coppersmith:

Thank you for the comments dated November 11, 2012, on Workshop #2. Our responses to the comments and reconunendations arc given below. 1£,,1"" (}Jvft<<t.A(..-.J Norm Abrahamson Chief Engineering Seismologist Pacific Gas & Electric Company p. 1 Response to Comments Our responses to the PPRP's comments and recommendations are provided below. We have attempted to respond to all of the PPRP comments; the explicit PPRP comment is shown first in italics, followed hy our response. Please do not hesitate to contact us if further clarification is required, or if we have inadvertently overlooked a comment requiring a response. Gene1*al Observations ln swm1U1JJ'* this was a11 excellent workshop and it adhered lo the requirements outlined in NUREG-2117.for a SSHAC Workshop #2. We agree that Workshop #2 was successful and provided important information for the Evaluation phase of the SSHAC process. Specific Comments and Recommendations 1. Project Schedule The PPRP recommends that a detailed schedule.for all working meetings, Workshop 3, deliverables, and other key activities be updated and issued by project management in tlze fonn of an updated Project Plan. As requested, we have updated the Project Schedule and are revising the Project Plan. A copy of the updated Schedule is attached to this response: and a copy of the updated Project Plan will he provided to you upon completion. At Workshop 3, the PPRP plays an active role and the preli111i11c11y model will he presented. Accordingly, Jhe PI'RP requires sufficient time to review the data evaluation and integration process, as well as the details of the SSC model. For the process to be effective, documents that describe the evaluation and integration processes need lo be provided to tlze PPRP in a timely fashion well in culvance of the worhhop. It is the Panel's understanding that the TI Team is i using data summmy and data evaluation sheets to document the data, models, and methods thaf: are being reviewed during the evaluation phase o,f the pro,ject. These data tables need to be completed by the 11 Team when the data are examined prior to lhe model building process. In addition to the data tables, the PPRP would like lo request a copy of the Hazard Input Document (HID, see NUREG-2117, Section 4. 7. 2) and any other documents that will describe the preliminalJ' SSC model. We agree with the need to provide adequate review time prior to Workshop 3. As per the attached schedule, we plan to provide the PPRP with the data evaluation and source sununary sheets and a description of the preliminary model (our logic tree model V2) two months prior to the workshop. As requested, an IIID will be provided to the PPRP prior to the workshop with sufficient time for a review. However, we envision suhmitting the HID of the preliminary model to the PPRP one month prior to the workshop following the submittal of the data evaluation, source summary sheets, and description of the logic tree model V2. p.2' We request that at least one member of the PPRP participates as an observer in the working meetings throughout the model building process leading up to WS3. As discussed in NUREG-2117 We agree. As shown on the project schedule, we plan to convene one formal Working Meeting per qua11er for the duration of the project. We will plan to notify the PPRP in advance so that at least one member of the PPRP can attend all \Vmking Meetings. The PPRP will be notified if additional fo1mal Working Meetings are added to the schedule and we will make every eff01t to make sure a member of the PPRP may attend. 2. Strategy for Recurrence Model Assessmem of the impact of using different recurrence models turns out to rank at the top of the tornado diagram in terms of hazard significance. The 11 team needs to develop a clear strategy on how to deal with non-Poissonian models in light of the fact that it is 1111/ikely that we/1-resolved information 011 the slip rates and timinK of past earthquakes on the fault zones will be available, which are critical to the hazard asse.\*sment at DCPP. Specifically, use of renewal models requires information on the recency and rate of activity of a specific fault and these types of data are not likely to be forthcoming in the time between now ,ind when WS3 is conducted. Tire Tl team will therefore need to develop 'md defend a model with large uncertainNes that 11wy have significant impact on the hazard to DCPJ>. Alternatil'ely, the TI team may wish to reconsider the use of non-Poissonian models, as it is clear.from lonK paleoseismic records in California that earthquake recurrence has demonstrably large coeffidents of variations and there is not a clear benefit in moving away from the srate-of-the-pmclice of using Poissonian recurrence distributions. We agree that the TI team needs to develop a clear strategy for addressing recurrence models as this appears to be one of the larger sources of uncertainty based on the tornado diagrams. However, we do not agree with the PPRP suggestion that there is no clear benefit to moving away from following state-of-the-practice and only using Poisson models for recurrence. Using only Poisson models is not consistent with the objective of capturing unce11ainty in the center, body and range of teclrnically defensible interpretations for source characterization. Lack of data is not a valid reason to reject alternative approaches lo model recu!Tence. Lack of data should lead to larger unce1tainty, not less uncertainty. Assuming a Poisson model because there are not enough data to constrain non-Poisson models is equivalent to saying that there is no uncertainty in the recutrnnce model. This approach will lead to increasing unce1tainty as mOl'c data arc collected. For example, if we only consider Poisson models as alternatives to Poisson models for faults in regions with abundant of data and only use Poisson models for regions with sparse data, then unce11ainty is systematically underestimated for regions with sparse data. The logic tree for regions with sparse data should be broad enough so that additional data collection in the future will lead to a reduction of uncertainty, not an increase in uncertainty. p. 3 If non-Possion models are a technically defensible interpretation for the behavior of fa.ulls or regions, then these models should be captured in the range of models developed by the TI team. The approach (or strategy) discussed in workshop 2 is to address temporal variations in the rate of seismicity due to renewal models or other causes by applying a scaling factor to the Poisson rate. In this case, the Poisson model will be used as the base-mode1, and the non-Poisson models will be captured by the range of scaled Passion models. The lask for lhc TI lcam will be to justify the range and weights for the scale factors that are applied. J. Strategy for Consideration of Research Projects Tire workshop pmvided an excellent opportunity for the Tl Team to understand the data, models, and methods that the larger technical community ;s using to characterize seismic sources in California. Jn most cases, the presentations and discussions involved research-oriented activities and initiatives (e.g., UCER.F3) tlrat are designed to (l) push tile state nf the art and (2) to provide input to regional seismic hazard studies. We suggest that the Tl Team develop a strategy for how they will evaluate these other efforts and what elements of those studies are applicable lo the site-specific SSC model and PSff A at the Diahlo Canyon site. For example, much of the discussion at the workshop surrounding tire concept a/segmentation resulted in the general agreement among the participants that the tool is used when high-quality behavioral data along a fault can be gathered and analyzed. There is Ii/lie prospect that such data can be gathered for the Hosgrifimlt, so a stratem1 will be needed for how the segmentation tool can be usecl, if at all, for tire DCP P SSC model. Similarly, the UCERFJ Grand In11ersion Clllempts to inco111orate various types of fault-specific information for the ma;orfaults of California and to inco1porate a wide variety of rupture scenarios within the constraints provided by issues such as moment and slip balancing. To what extent can the UCER.F3 model provide re/;able estimates of SSC parameters/or thefi111/ls in the DCPP area? Tf the UCRRFJ model is not judged to have suj}icient resolution to provide direct information 011 the local fimlts, should the conceptual models embedded in the UCERF3 model be adopted locally for DCPP? (e.g., local moment balancing, soft segmentation points resultingfi*om slip rate differences). Because the UCERF3 model is regional and has been designed to provide regional seismic hazard, should it be used at all as either a direct inplll or e11en to inform the DCPP SSC mndel? These are all issues that we suggest need to be included and in the development of an o\lerall strategy for the SSC model. We agree that a clear strategy needs to be developed and aiticulated regarding how the stawide UCERF3 model is considered in the site-specific DCPP SSC model. The PPRP commei1I describes some of the concerns with the UCERF3 model and its applicability for a site-specific investigation. We know, for example, that the UCRRF3 model inputs do not adequately capture the uncertainties in fault source geometry and fault slip rate for the four primary faults contributing to hazard at DCPP .. Fm1hermore, we agree that the Grand Inversion is best suited to characterize major California faults with abundant paleoseismic data, and that it may provide less meaningful results to the short, low slip rate, relatively data poor faults of major interest to DCPP. However, many of the concepts and approaches developed by the UCERFJ effort (available as appendix repo1ts to the overall UCERF3 report) contain valuable infom1ation regarding multi-segment and multi-fault mptures, and the solution files to the UCERF3 model contain insights into the possible behavior of mulli-segment and multi-fault ruptures that need to p.4 be evaluated and considered. Thus, our plaru1cd approach is to Jay out the strategy for considering the UCERF3 model for Diablo Canyon in a "white paper" that can be provided to the PPRP as part of the data documentation deliverable prior to workshop 3. Jn summary, the range of uncc11ainty in the final SSC model should capture the aspects of the UCERF3 model that are considered to he applicable to the DCPP region. This may he achieved without directly implementing the UCERF3 model in the final SSC logic tree, but by selectively incorporating philosophies imbedded in the UCER.F3 model oflinked fault rnptures. 4. Full participation of All Members of the Tl Team

• At the workshop, four out of the five members of the TI team were fully engaged in the discussions. All five memhers need to be fully engaged and up lo speed on all issues related to the SSC model as any member may be called upon in J'.fSJ to defend or explain aspects of the model. In other word{j, all .five members need to take complete ownership of all aspects of the model .... If not all team members possess the attributes requiredforparticipC1tion on the Tl Team, the TI Lead should consider replacing those members that do nnt. Time is short and all members will need to he fully engaged to make the deadlines laid out in the project plan. Given the nature of the evaluations that lie ahead for the Tl Team, it may be prudent to include a memher with e.\pertise in geophysics and seismology. We agree that all members of the Tl Team need to be fully engaged in the Evaluation and Integration process, including full participation at each Workshop. The member of the TI Team that was not engaged in the discussions has agreed to step down from the TI Team. A replacement for this person has not yet been identified. Regarding the PPRP recommendation that we consider a membel' with expe11ise in geophysics and seismology, we have discussed adding Glen Biasi as a TI Staff Supp011 person. Dr. Biasi may move into a full TI Team member depending on his time commitments and ability to "catch up" with the current TI Team's progress in the Evaluation process. 5. Strategy for hazard model development The workshop did a ve1J> goodjoh of reviewing relevant research onfimlf behavior. There is clearly a KJ'Oll'ing recognition thaf a m11/tiplicity of rupture modes is possible on the regionC1/ fault system in California. For example, ruptures may linkfiwlts in a great mnnher of-ways. A rupture may nucleate on one fault and transfer to other faults, even to faults of differing senses of slip. Critical points on faults (e.g, fault intersections and splays, stepovers, etc.) may sometimes become rupture endpoints, sometimes not, with probabilities that are still poorly understood. The project is therefore faced wilh a number of chclllenges: (I) Research 011 rupture modes such tis that being conducted under UCRRF-3 is at a regional scale, and only indirectly informs model buildinf{ at the local scale relevant ro the SSHAC study. (2) For the most part, the data required to apply those ideas are absent in the central coast region (e.g., reliable slip rates and timinf{ of pas/ rupture.5.). (3) That research is rapidly evolving. (4) It is possible that these complex multifault rupture models may raise significant i1Ue1face issues when translated into ground motion models. (5) Given the very large numher of potential linkaf{es, end points, and segmentation models, a hazard model could quickly become unwieldy and incomprehensible. p. 5 The PPRP rherefore recommends tltat tlte Tl team develop, al the outset, a clear strategy.for co11str11ction of a workahle hazard model. Some elements that should be considered: (!) llazard sensitivity may be an important element of that sh*ategy. While all technically defensible models must be evaluated, it will prohahly he possible to eliminate some model complexities early in the evaluation pmcess by documenting an absence of hazard significance. (2) The team needs to establish a clew* cut<:?[( on the consideration of emerging research results. (3) The strategy should consider potential ground motion inte1face issues. For example, ruptures that linkfiwlts wUh different senses of slip may raise substantial new problems when translated into ground motion modeling. We agree with the PPRP comment that the complexities of some of the source models discussed at Workshop 2, such as complex multi-fault ruptures, could he difficult to impkment in the PSHA calculation and also may not have a significant effect on the hazard. As recommended by the PPRP, hazard sensitivity sludies will be used to eliminate some model complexities that are not significant lo hazard and to justify simplification of the source modeJ. The Tl Team will evaluate if the standard form of the models can be used to capture the key aspects of the SSC. For example, a hazard sensitivity study will be conducted to dete1mine if using a large number of individual complex multi-fault ruptures leads to significantly different hazard than using a more limited selection of ruptures that captures the range of uncertainty implied by the complex models. As noted by the PPRP, lhe interface between the SSC and GMC Tl Teams will be critical for implementing various issues of complex multi-fault ruptures with mixed mechanisms on different segments. We will start with a simple approach of using bounding cases, such as using pure strike-slip and then pme reverse slip for a multi-fault rupture that involves both strike-slip and reverse-slip segments. If the rates of such complex rnptures are low, then there will not be a significant effecl on hazard and a simplified approach can be used. If thcre is a significant effect on hazard, then other methods, such as using finite-fault simulations will he used to develop an appropriate method to address the interface issue. 6. Data Tables All data that ltave been evaluated by the Tl Team should be documented ;n dara tables such that the Team can represent !he center, body, and range of technically defensible interpretations the model building process. Accordingly, data summary and evaluation tahles should ro be completed when data are examined and evaluated. Evaluatfon entails a mrmber of activities idenf{fying important technical issues cmd tlte ability of the data to address those issues, as well as evaluating the data in terms C?f their quality and relevance to the assessments being made. integration is model building to arrive at a defensible expression of knowledge and uncertainty of the inputs to the model, due consideration to the available data. This includes the full expression of the model elements (logic-tree their relative weights, and tire range C?f credible uncertainties. Docmuenlation of data evaluation and integration is one of the most important parts of the SSHAC process; it should be pe1formed concurrently with model building. The PPR P needs* timely access to this documentation throughout the model building process in order lo pe1form independent evaluation p. 6 We agree thal documentalion of the data evaluation process is an important element of the SSHAC process. The TI Team is prepa.l'ing both Data Evaluation and Seismic Source Summary tables that document the data evaluation process and use of the data in the integration and model building phase of the project. These tables are being prepared concurrent with both the Data Evaluation and Integration Model Building phases of the prqjcct, and will be available to the PPRP for independent review. 7. Lexicon of Terms During the course of Workshop 2, it became clear to the PPRP that key proponent experts were using terminolozy that had a different meaning for different people. As an example, the term fault segment" was used by one expert to imply that a section or sections of a fault alw<1ys ruptures together, whereas others used the same term to represent a change in the style or rate of faulting, a change in fault geomefly, or some other aspect of the fiwlt as a way 10 describe different secrions of a fault zone. This causes confusion among the project participants, as well as among outside observers, and could be easily corrected by development of a lexicon of key terms that are used in this s111dy. The PPR P recommends that such a lexicon of de.fin it ions be developed/or key terms that will be used in the models and reports completed for this project, and that this lexicon be distributed to the appropriate expel'fs lo c1ssure common understanding of key issues. We agree. A lexicon of terms or glossary will he developed for the prqject. 8. Site-Specific SSC Model Acknowledgh1g the excellent cross-section of SSC talent brought to the workshop fiwn the larger community, the Panel notes that nearly all of the participants come.from the research community and are involved in regional seismic hawrd studies that are not intended to be used for site* specific use and certainly not for use in evaluating the seismic design of nuclear power plants al low annuaJ.fi'equencies of exceedance. Although many of the basic seismic source characterization issues are common to both regional and local I'SHAs, there are unique issues that come info play for site-specific studies that the TI Team will face, but could not be culdressed by the participants at the workshop specifically. For example, detailed modeling of fault geometries in the vicinity of the plant site will be important and local constraints on potential models of ruptures that email fiwlts huving different senses may need to be considered. Practical ways of deciding upon the fault-specUlc selection of applirnble magnitude fi*equency distriblllions, and decisions regarding appmpriate ways of the epistemic uncertainty in recurrence behavior *will need to be considered. These are issues that have been addressed to some extent hy others who have developed sife-spec{fic SSC models for nuclear facilities. ft is suggested that the Tl Tewn consider the models and developed by other resource experts having site-fjpecific PSHA e,,perience. That experience nwy provide the ream H1fth additionc1I insights and practical approaches that have been used to address common problems. p. 7 We respect this observation from the PPRP, and \.Viii take your suggestion to consider other specific SSC models for nuclear facilities into consideration. However, we ofter the following response: (1) Development of the SSC model involves both an evaluation of the current status of knowledge within the scientific community on issues related to seismic source characterization (e.g., status of the C,B,R of TOI for segmentation, multi-fault rnptures, recurrence models, geodesy, etc) as well as an evaluation of approaches/methods for implementing this infomiation into an SSC model for input to a PSHA. We designed Workshop #2 and invited Resource and Proponent Experts to explicitly discuss both of the above. (2) In terms of generic site-specific SSC models for nuclear facilities, between the Tl Lead (William Lettis) and TI Support Staff (Kathryn Hanson), the TI Team has the experience of approximately 90% of the SSC models developed for nuclear facilities over the past ten years. In addition, the technical community of individuals with experience developing SSC models for nuclear facilities is relatively small. We also invited Dr. Robert Youngs to attend Workshop #2 to discuss various implementation approaches, but he was unable to participate. In addition, similar to other SSHAC Workshop #2s where the USGS model and approaches were discussed, we fully explored the UCERF3 model, and the TI Team is participating in other working meetings to discuss how the UCERF3 model will be incoiporate<l into the National Seismic Ha7.ard Map as well as how the model may be adapted for site-speci fie use. (3) In tenns of site-specific models of relevance to Diablo Canyon, there is only one -the SSC Model developed for the PG&E J .TSP (PG&E, 1988). This model was fully explored and updated at the meeting by various Proponent Experts involved in the f.TSP model. 9. Aleatory Approach to Segmentation The discussions of fault segmentanrm at rhe workshop provided a valuable range of viewpoints on the issue and served to highlight not 011ly the differences in models, but also the potential approaches that the Tl Team might take as they mnve f01ivard constrncting their SSC model. It is clear to the Panel that the community has moved away from considering the alternative segments that might result fi'om a given segmentation model as epistemic alternatives toward a more aleat01y model that includes the occurrence of a wide range of rupture scenarios at their applicable relative frequenlJ'. For example, the presentation by Glenn Rias; and comments by Sieve Wesnousky reinforce the notion that a ve1y wide range of possibilities are observed/or possible controls of rupture segments, but it is more fi*uitful to consider the relative fraction or frequency with which those controls might limit or extend the ruptures. We suggest that the Team consider moving toward this type of aleat01y tre(lfment of altemarive rupture scenarios-one
• that might include (I number of credible scenarios each with its relative frequency of occurrence. lt is also suggested that the Tecm1 consider the rupture case hislories discussed at the workshop relcttive to the specffic rnpture scenarios that might be included in the SSC model. For example, the Denali earthquake appears lo have 1111cleated on a relatively small thrust fa11lt, with rupture then propagating onto the main strike slip Denali fault. This event and others like it might serve as potential analngs for the relationship between the fiwlts that appear to merge with the Hosgri fault. Likewise, the workshop highlighted the value that might come /mm considering the orientation of principal stresses relative ro the orientation of faults as they change trend. These and other case histories could provide a basis for the consideration and selection of credible and defensible rupture scenarios for the SSC model. p. 8 We agree with the PPRP observation that it may be more appropriate to model earthquake rupture scenarios as an aleatory unce11ainty with an assessment of their applicable relative frequency of occurrence. We wiJl incorporate this concept into our SSC model. The TI Team is developing approaches to inco1vorate the full range of unce11ainty in rupture models into the SSC model. We also agree that earthquake rnptures such as the Denali rupture (also the I 950 Kern County rupture) during which both strike slip and reverse slip occurred may serve as analogs for the Hosgri fault and neighboring faults in the Diablo Canyon region. These past ruptures are being used by the TI Team to inform our assessment of possible rnpturc scenarios for the SSC model. p.9

"'? _. 0 Tm 1: Prop..v.illon of Draft Pl:ln """ ln111.11 Sor>SIUVl!y ANIY'JS Taolc2; W011<$Mp 0 (Kick.off MooUna) J; Ev31uatton Ta*k 4: Workollop 1 -Slgnlftc:.:lnl b!luo11.1 Av41Ual1to Dat.:t, .,n<I D:IQ Nood*: Mod"I VO S<rnSIUvlry 5: O;,t:i Evll!u1>t1on and ntOD,..IOn Jor SSC Son"d*llY I.ogle roe a; Workshop 2 -Pro.,.,,,ent MOClelO, SSC MO<IOI VI Snn>ltlvll)' r .... 7: Dab EvOIU3tlon *r>a ln"'ll""'on for SSC Model V2 T3Sll ll: Wotbllop 3-lbmrd Fo.-!b:lctc WorkshOp :Z.S-27. SSC MO<lct V2 H>brd Ta*k 9; Oa\/olop Fl..,I Model: SSC MOf!ol VJ 31\d R01>0rtln11 T.>*k 10: ,ln*I Pl>lll' !WvloW ... a Sul>mlb:ll 5 Figuro 2 -Olablo Canyon SSC project $Chedule 2011 2012

• I 10 I 11 I u I 1 I ' I 11111 I *: I 1 I : .. * -:_,;I: 2013 'I 1tl u 11211 Ongoing PG&E Program Notes 1 -SWUS GMC 1 2 -seismic SllJ:ly letter re:iort. :>11.-..<;e : I 3 -L TSP Briefing (resulls of on9oin9 SSC studies) 4 -Ottsnore low*energy seismic studies letter repc11 5-SWUS GMC WnooMp2 6 -Ol'ISnore seismic study letter report, phase 2 7 -Prelimioary SSC mot!el V2 to PPRP e -SW..JS GMC WOntshop J 9 -Final Briefing Meeting wilh Hazard Input Oocul:lcnt 1 Ii I l 14 Sj 6 I >-17 :* J: 1 *: I e 2014 2015 1 t, ...,, ,, , ,,. , 9110 I May 16, 2014 Kevin Coppersmith Chair, DCPP SSC PPRP

Subject:

Response to Participatory Peer Review Panel (PPRP) comments on DCPP SSC Workshop #3, Dated April l, 2014

Reference:

Participatory Peer Review Panel Report on Workshop #3, Diablo Canyon Seismic Source Characterization Workshop #3 from Dr. Kevin Coppersmith (Chair), Dr. Steve Day, Dr. Neil Driscoll, and Dr. Tom Rockwell

Dear Dr. Coppersmith:

Thank you for your comments and recommendations on the Diablo Canyon SSC Workshop No. 3 <lated April I, 2014. Our responses to the comments and recommendations arc given below. The PPRP comment is provided in its entirety in italics, followed by the TI Team response. In addition, please find attached an updated schedule through completion of the project. Thank you for your comments, and please do not hesitate to contact me at ( 415) 973-5291 if you would like to discuss the responses. Sincerely William Lettis SSC TI Lead Response to Comments Our responses to the PPRP's comments and recommendations are provided below. We have attempted to respond to all of the PPRP comments; the explicit PPRP comment is shown first in italics, followed by our response. Please do not hesitate to contact us if further clarification is required, or if we have inadvertently overlooked a comment requiring a response. General Observations We would like to thank and congratulate the SSC Tl T earn for a successful workshop. It was clear that much work was done prior to and during the workshop to cover the entire SSC model, its detailed implementation, and its technical justification. We also congratulate the PG&E team for making all of the logistical arrangements to ensure a smoothly run workshop. Thank you. We agree that Workshop #3 was successful and provided important feedback information for the Integration and Model Development phase of the SSH AC process. Specific Comments and Recommendations I. SSHAC Level 3 Process The goal of Workshop #3 within a SSHAC Level 3 process, as described in NUREG-2117, is to provide the Tl Team with feedback in two forms: 1) hazard sensitivity analyses that provide insights into the most significant parts of the preliminary SSC model, and 2) feedback from the PPRP regarding the technical support for the model and the degree to which the model captures the CBR of the TD/. Further, NUREG-2117 prescribes the specific roles that various participants should assume during the course of WS3. For example, all members of the Tl Team are expected to participate in the presentation, discussion, and technical justification for the preliminary SSC model. We were pleased to see that this was certainly the case and this led to provoking discussions and insights into details of the SSC model components, as perceived by various Team members. At WS3 the PPRP is free to question members of the Tl Team regarding details of the SSC model and the technical justification for model elements and the treatment of uncertainties. In this regard, the Tl Team encouraged active PPRP participation and was responsive to the questions posed by the Panel. For example, the Team responded to the Panel's request for changes to the workshop agenda, which allowed additional time to discuss the approach to recurrence modeling. Also, in many cases, the Team positively considered the comments posed by the Panel and will use that information during the finalization of the SSC model. Other aspects of the SSHAC Level 3 process were appropriately conducted. Training in the proper roles of the workshop participants was performed daily, and those roles were enforced. For example, the role of observers was identified throughout the workshop and adequate time was provided for observers to comment on the proceedings daily. An additional bonus, for which the PG&E team should be congratulated, was the organization of a special session at the end of each day to allow the general public to ask questions related to the scientific issues surrounding earthquake hazard analysis. Typically, WS3 within a SSHAC Level 3 project occurs after the completion of the evaluation phase of the work such that proponent and resource experts are not present. An unusual aspect of this project is that data collection activities associated with AB 1632 are ongoing and the PSHA project must consider the results of those activities. Accordingly, PEs and REs were present and participated in the workshop to report their findings. However, the Tl Team was careful to define their role in the workshop and to make it clear how the Team would be considering the results of those studies in the future. The preliminary SSC model was not complete at the time that hazard calculations and sensitivity analyses were conducted for the workshop. However, the PPRP concludes that a sufficient framework, and components of the model had been completed to provide a significant amount of useful feedback to the Team to assist them with the completion of the integration phase of the work. In order for the work to be completed according to the schedule, it is recognized that a significant amount of work will need to done-in a properly prioritized manner-to arrive at a final SSC model. Prior to that time, the Panel would like to continue to review the development of the model prior to the review of the draft PSHA report. Suggestions for the elements of that review are described below under "SSC products for PPRP review." Also, the impact on the schedule will be important and we discuss this below in "Need for PSHA Schedule." We agree that new information has and will become available to the TI Team for evaluation and integration, as appropriate, into the Final SSC Model. We will continue to keep the PPRP appraised of our evaluation and integration of the new data and development of the SSC model. As per the attached schedule, we will convene a Final Briefing to review the model with the PPRP prior to submittal of the draft SSC report. In addition, the TI Team will convene several Working Meetings to finalize development of the Preliminary SSC model, in particular development of the recurrence parameters (effective Poisson rate). We will invite the PPRP to attend these Working Meetings, either in person or via teleconference call or webinar, and to provide feedback to the TI Team. 2. Need for PSHA Schedule Given that the preliminary SSC model is not yet complete, due primarily to the need to finish the ongoing data collection program, we anticipate the need to carefully schedule and prioritize the effort to first complete the preliminary SSC model, obtain additional SSC products and hazard sensitivity results (see below), finalize the SSC model, and document the PSHA report. Specifically, the elements of the schedule that we would like to see on the calendar are the following: *Completion of the preliminary SSC model *Delivery of the preliminary SSC model Hazard Input Document (HID) to the PPRP

• Finalization of the SSC model *Briefing with the PPRP to review the final SSC model
• Delivery of the Draft PSHA report to the PPRP for review
• Review of the Draft PSHA report by the PPRP (minimum six weeks required)
• Delivery of PPRP comments to the Tl T earn *Delivery of Draft Final PSHA report to PPRP for final review *Delivery of PPRP Closure Letter to PG&E We have incorporated these clements of the schedule into the updated Project Schedule, as attached. 3. SSC Products for PPRP Review In order for the Panel to have a full understanding of the SSC model, we would like to request the following products be provided. We understand that all of these products are already part of the planning and deliverables anticipated by the project, but we would like to emphasize their importance to the Panel by listing them below:
• Recurrence curves for rupture sources, particularly for the Hosgri fault *Implementation of the WAACY model for linked ruptures (Mmax ruptures); how do you arrive at b-taif and tail offset? _____________________________ _ *Approach to the use of non-Poisson recurrence models, the logic tree distribution of equivalent Poisson rates, and their impact on hazard and uncertainty contribution
• Impact of logic tree branches for Mchar and Mmax on hazard
• Impact of categorization of rupture sources as either Mmax and Mchar *Discussion of what is aleatory and what is epistemic (e.g., Mmax logic tree, versus aleatory rupture sources) *Hazard sensitivity for all of the above, including running the Shoreline Fault Report model with the new Hosgri rates The documentation will provide the TI Team* s assessment of the above source characteristics, including sensitivity feedback on each of these issues. The TI Team appreciates the feedback from the PPRP at the Workshop on each of these topics, and wil1 address each of these topics at the Final Briefing as well as in the project documentation. 4. Tl Team Action Items The Tl team did an excellent job discussing/summarizing each day's results as well as developing a list of action items required to finalize the SSC model. The PPRP endorses such an approach. Here, we review the Tl team's action items according to an overarching theme, not priority. The PPRP is NOT directing the Tl team with regard to which action item or scope of work needs to be completed; such decisions are the responsibility of the Tl team as they finalize the SSC model. It should be noted that some of the actions identified by the Tl Team relate to immediate actions that are needed to finalize the SSC model, other actions relate to documentation that will be provided in the PSHA report. We include both types of actions in our comments below. a. Documentation of Piercing Points. Documentation of piercing points for offshore fault systems and age models is required. Specifically, the Tl team should explain how the piercing points are used to constrain slip distribution along the fault with the full range of interpretations reported. When multiple piercing points yield different offsets and imply different rates, the Tl team should document how the geologic slip rate distribution is characterized along the fault. We agree. The documentation will include a discussion of how the distribution of slip rate is characterized along each fault, and how various piercing points arc used to constrain fault slip rate, including assessments of data quality, distance along the fault from the DCPP site, age of piercing point, etc. b. Document Use of ONSIP Results. After the SSC model has been finalized, the Tl Team should document how or if new ONshore Seismic Investigation Project (ONSIP) results are used to constrain fault geometry and locations in the Irish Hills. For example, will the dip of the Los Osos and San Luis Bay faults in the OV, SW, and NE tectonic models be constrained by the ONSIP data? Results from the ONSIP study will be evaluated and integrated, as appropriate, into the SSC model. We anticipate that the ONIP data will provide important constraints on the down-dip geometry of some (but not all) faults in the OV, SW and NE tectonic models. The documentation will provide the Tl Team's assessment of the ONSIP data and how the data are used to constrain fault geometry in the three alternative tectonic models. c. Document Definitions of Styles of Faulting. The three proposed tectonic models (OV, SW, NE) entail a rather large range of rakes on some of the individual faults (e.g., the San Luis Bay and Los Osos faults). The style-of-faulting (SOF) categorization of a fault for purposes of applying GMPEs depends upon its rake. We recommend that the SSC Tl team coordinate with the GMC (SWUS) team to ensure that appropriate GMPE SOF classes are assigned to the faults, recognizing the SOF assignment for a given fault may vary depending upon which tectonic model it is participating in. We agree. The Tl Team will coordinate with the GMC (SWUS) Tl Team to ensure that the Final SSC model and HID describe the appropriate rakes for use for each fault in applying the GMPEs. We are aware that the style-of-faulting and rake may vary, both along strike in a particular tectonic model, as well as between models. d. Carefully document/compare with UCERF3. The PPRP agrees with the Tl team's action item to compare the slip rate models, linked rupture models and rupture participation rates to the corresponding UCERF3 results. The SSC model is based on a more current data set for the local faults than is the UCERF3 model, so agreement is not necessarily to be expected. Rather, the objective should be to document the comparison, pointing out any important differences and explaining why they arise. The documentation will include a comparison of the SSC model to the UCERF3 model results, including rupture participation rates for those fault "sections" closest to DCPP. We agree with the PPRP that agreement is not necessarily expected, but our documentation will include an assessment of any differences and an explanation of why they arise. e. Documentation of Slip Allocation and Budget. It is critical that there be complete documentation on how slip is allocated among the various rupture sources and various models to construct the final slip budget. The allocation of slip budget to various earthquakes in the final model will drive the ultimate shape/form of the MFDs, which are the basic input to the hazard model. The documentation wi11 include the Tl Team's assessment of how slip rate is allocated among the various rupture sources within each tectonic model, and how the slip budget for the combined rupture sources adds up to equal each fault slip rate. The TI Team recognizes the impo11ance of this assessment for allocating slip budget to various earthquakes, and significance to the hazard model. f. Explain Differences in Hazard with that of the Shoreline Fault Report. It was clear during multiple/various presentations that the current assessment of hazard is consistently lower than that presented in the Shoreline Report, possibly based on updated information on fault slip rates. This is a significant feedback issue and will need to be understood prior to finalization of the SSC model, and will ultimately need to be completely documented. The documentation will include a comparison of the SSC model hazard results to the Shoreline Fault report hazard results, pointing out any important differences and the TI Team* s assessment of why they arise. The comparison also will be made using the updated SWUS GMPE model for the DCPP site. g. Age Model in the Offshore. The PPRP was pleased to see a coherent age model presented by various PEs and members of the Tl team for use in the assessment of slip rates for the offshore faults illuminated by the LESS studies. This represents an improvement over earlier presentations and indicates a maturation of the offshore age model that is now being applied in the assessment of slip rates. The PPRP has increased confidence that the final slip rates that will be assessed and completely documented by the Tl team in the final report will rely on a mature, defendable age model. The documentation will include the TI Team's assessment of the offshore LESS study for use in constraining the distribution of slip rate along offshore faults. Results from the LESS study will be finalized in June, 2014, and will be evaluated and integrated, as appropriate, into the Final SSC model. We agree that preliminary results from the LESS study have described what appears to be a coherent, well documented age model using sequence-stratigraphy correlation dating methods. The TI Team recognizes the importance of carefully evaluating the LESS study results for assessing and constraining both fault location and distribution of fault slip rate. h. Documentation of Hazard Sensitivity to Fault Models. The three primary fault models could represent different hazard levels at DCPP. It will be important to document the hazard sensitivity of these various models to establish whether one model represents a substantially higher hazard than others, and to be sure that all assumptions are well-founded and applicable uncertainties incorporated. The documentation wi11 include hazard sensitivity analyses comparing each alternative tectonic model, and elements within each model. The assumptions and technical bases for each model will be described in the SSC report. The epistemic weighting given to each model, and elements within each model, however, will be based solely on the technical assessments and not on the level of hazard that each model represents.

January 9, 2015 Mr. Kent S. Ferre Project Manager Pacific Gas & Electric Company 245 Market St. San Francisco, CA 94177

SUBJECT:

Participatory Peer Review Panel Letter No. 2: DCPP SSC SSHAC Project Draft Report Installment #2

Dear Mr. Ferre,

This letter provides in writing the comments of the Participatory Peer Review Panel (PPRP) on the Diablo Canyon Seismic Source Characterization (SSC) SSHAC Project Draft Report. We (Coppersmith, Day, Rockwell, and Driscoll), the designated PPRP, want to express our appreciation for the opportunity to review Installment #2 of the Draft Report, which consists of Chapters 6, 7, 11, and 12, as well as the EPR Appendix. Our review comments are provided in the attached table and each comment is associated with a unique number that continues consecutively from our comments on Installment #1. The table includes a column for the Tl Team to summarize the revisions made to the report to respond to each comment. We would request that a completed copy of the table be returned to us with the revised report to expedite our follow-up review. We look forward to answering any questions of clarification regarding these comments during our conference call on Wednesday, January 14, 2015. Sincerely, DCPP SSC PPRP K. Coppersmith, Chair S. Day N. Driscoll T. Rockwell January 21, 2015 Mr. Kent S. Ferre Project Manager Pacific Gas & Electric Company 245 Market St. San Francisco, CA 94177

SUBJECT:

Participatory Peer Review Panel Letter No. 3: DCPP SSC SSHAC Project Draft Report Installment #3

Dear Mr. Ferre,

This letter provides in writing the comments of the Participatory Peer Review Panel (PPRP) on the Diablo Canyon Seismic Source Characterization (SSC) SSHAC Project Draft Report. We (Coppersmith, Day, Rockwell, and Driscoll), the designated PPRP, want to express our appreciation for the opportunity to review Installment #3 of the Draft Report, which consists of Chapters 9 and 10, as well as the WAACY Appendix. Our review comments are provided in the attached table and each comment is associated with a unique number that continues consecutively from our comments on Installment #2. The table includes a column for the Tl Team to summarize the revisions made to the report to respond to each comment. We would request that a completed copy of the table be returned to us with the revised report to expedite our follow-up review. We look forward to answering any questions of clarification regarding these comments during our conference call on Friday, January 23, 2015. Sincerely, DCPP SSC PPRP K. Coppersmith, Chair S. Day N. Driscoll T. Rockwell February 12, 2015 Mr. Kent S. Ferre Project Manager Pacific Gas & Electric Company 245 Market St. San Francisco, CA 94177

SUBJECT:

Participatory Peer Review Panel Letter No. 3: DCPP SSC SSHAC Project Draft Report Installment #4

Dear Mr. Ferre,

This letter provides in writing the comments of the Participatory Peer Review Panel (PPRP) on the Diablo Canyon Seismic Source Characterization (SSC) SSHAC Project Draft Report. We (Coppersmith, Day, Rockwell, and Driscoll), the designated PPRP, want to express our appreciation for the opportunity to review Installment #3 of the Draft Report, which consists of Chapter 13, Appendices H, S, and Y, and the Earthquake Catalog Appendix. Our review comments are provided in the attached table and each comment is associated with a unique number that continues consecutively from our comments on Installment #3. The table includes a column for the Tl Team to summarize the revisions made to the report to respond to each comment. We would request that a completed copy of the table be returned to us with the revised report to expedite our follow-up review. We look forward to answering any questions of clarification regarding these comments during our conference call on Tuesday, February 17, 2015. Sincerely, DCPP SSC PPRP K. Coppersmith, Chair S. Day N. Driscoll T. Rockwell February 20, 2015 Mr. Kent S. Ferre Project Manager Pacific Gas & Electric Company 245 Market St. San Francisco, CA 94177

SUBJECT:

Participatory Peer Review Panel Comments DCPP SSC SSHAC Project Draft Report Installment #5

Dear Mr. Ferre,

This letter provides in writing the comments of the Participatory Peer Review Panel (PPRP) on the Diablo Canyon Seismic Source Characterization (SSC) SSHAC Project Draft Report. We (Coppersmith, Day, Rockwell, and Driscoll), the designated PPRP, want to express our appreciation for the opportunity to review Installment #5 of the Draft Report, which consists of Chapter 14. Our review comments are provided in the attached table and each comment is associated with a unique number that continues consecutively from our comments on Installment #4. The table includes a column for the Tl Team to summarize the revisions made to the report to respond to each comment. We would request that a completed copy of the table be returned to us with the revised report to expedite our follow-up review. Please feel free to contact Kevin with any questions of clarification regarding these comments. Sincerely, DCPP SSC PPRP K. Coppersmith, Chair S. Day N. Driscoll T. Rockwell ( >/] P<N:iii;: .-w,J I' * * :i --March 11, 2015 PG&E Letter DCL-15-035 Barry S. Allen Vice President. Nuclear Services Oiablo Canyon Power Plan I Mail Code 104/6 P. 0. 56 Avila Beach. CA 93424 805. 545, 4668 Internal: 691.4688 Fal: 805. 545. 6445 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk 11555 Rockville Pike 10 CFR 50.54(f) Rockville, MD 20852 Docket No. 50-275, OL-DPR-80 Docket No. 50-323, OL-DPR-82 Diablo Canyon Units 1and2 Response to NRC Request for Information Pursuant to 1 O CFR 50.54(f) Regarding the Seismic Aspects of Recommendation 2.1 of the Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accident: Seismic Hazard and Screening Report

References:

1. NRC Letter, "Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Recommendations 2.1, 2.3, and 9.3 of the Near-Term Task Force Review of Insights from the Fukushima Dai-lchi Accident," dated March 12, 2012 2. Electric Power Research Institute (EPRI) Report No. 1025287, "Seismic Evaluation Guidance: Screening, Prioritization and Implementation Details (SPID) for the Resolution of Fukushima Near-Term Task Force Recommendation 2.1: Seismic," dated November 2012 3. PG&E Letter DCL-13-044, "Response to NRC Request for Information Pursuant to 1 O CFR 50.54(F) Regarding the Seismic Aspects of Recommendation 2.1 of the Near-Term Task Force Review of Insights from the Fukuhsima Dai-ichi Accident," dated April 29, 2013 4. NRC Letter, "Supplemental Information Related to Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Seismic Hazards Reevaluations for Recommendation 2.1 of the Near-Term Task Force Review of Insights from the Fukushima Dai-lchi Accident," dated February 20, 2014 A member of tlie STARS (Strategic Teaming and Resource Sharing) Alliance Callaway

• Diablo Canyon
• Palo Verde
• Wolf Creek I° -{'-Document Control Desi< !Jfi March 11, 2015 Page2

Dear Commissioners and Staff:

PG&E Letter DCL-15-035 On March 12, 2012, the Nuclear Regulatory Commission (NRC) issued Reference 1 to Pacific Gas and Electric Company (PG&E) directing PG&E to reevaluate the seismic hazards at Diablo Canyon Power Plant (DCPP) using present-day NRC requirements and guidance and to identify actions to address plant specific vulnerabilities associated with the updated seismic hazards. Specific requirements are outlined in Reference 1, Enclosure 1 . In response to Reference 1, and following the guidance provided in Reference 2, PG&E performed a seismic hazard reevaluation for DCPP and developed a specific ground motion response spectrum (GMRS) for screening purposes. Enclosure 1 to this letter provides PG&E's Seismic Hazard and Screening Report. Consistent with Reference 41 the enclosed seismic hazard reevaluations are distinct from the current design and licensing bases of DCPP. Consequently, the results of these analyses -performed using present-day regulatory guidance, methodologies, and information -would not generally be expected to call into question the operability or functionality of structures, systems and components, and were not reportable pursuant to 1 O CFR 50. 72, "Immediate Notification Requirements for Operating Nuclear Power Reactors," and 10 CFR 50.73, "Licensee Event Report System." The GMRS was developed through the performance of a Senior Seismic Hazards Analysis Committee (SSHAC) Level 3 seismic source characterization study and a SSHAC Level 3 ground motion characterization study, in accordance with NUREG 2117, "Practical Implementation Guidelines for SSHAC Level 3 and 4 Hazard Studies," dated April 2012, followed by a site-specific amplification study. A copy of the participatory peer review panels (PPRP) closure letters for seismic source characterization and the ground motion characterization (GMC) is provided in Enclosure 1, Appendix C. The GMC closure letter found that the DCPP SSHAC meets the expectations for a SSHAC Level 3 study but requested that additional technical justification be provided regarding the application of the directivity component of the GMC model to the DCPP site. The SSHAC Technical Integration team provided a response to the PPRP request (see Enclosure 1, Appendix C). PG&E will submit the resolution of the PPRP identified request as soon as it is completed. As discussed in* NRC Letter, "Diablo Canyon Power Plant, Unit Nos. 1 and 2 -NRC Review of Shoreline Fault (TAC Nos. ME5306 and ME5307)," dated October 12, 2012, PG&E's reevaluation used the DCPP double design earthquake (ODE) as the safe shutdown earthquake for screening purposes. PG&E's screening evaluation of the GMRS indicates that the GMRS exceeds the DDE in the 1 to 10 hertz frequency range. Therefore, DCPP screens-in for a seismic risk evaluation A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway

• Diablo Canyon
• Palo Verde
• Wolf Creek j Document Control Desk March 11, 2015 Page 3 PG&E Letter DCL-15-035 in accordance with Reference 2. PG&E will perform the seismic risk evaluation as required in Reference 2. In the interim, PG&E compared the GMRS to the design and licensing basis 1977 Hosgri earthquake spectrum and to the results of the long term seismic program seismic margins assessment. These comparisons demonstrate that there is reasonable assurance that the DCPP structures, systems, and components required for safe shutdown will continue to perform their intended safety function if subjected to the ground motions at the newly developed GMRS levels. PG&E will perform an update of the seismic probabilistic risk assessment (PRA), which will include high-frequency confirmation, and a spent fuel pool integrity evaluation in accordance with Reference 2. PG&E is making a new regulatory commitment (as defined by NEI 99-04). PG&E is revising an existing regulatory commitment as shown in Enclosure 2. PG&E has determined that it is not necessary to perform an expedited seismic evaluation process as PG&E's interim evaluation provides reasonable assurance that it is safe to operate DCPP while the updated/upgraded seismic PRA is developed. Refer to Enclosure 2. If you have any questions, or require additional information, please contact Mr. L. Jearl Strickland at (805) 781-9795. I declare under penalty of perjury that the foregoing is true and correct. Executed on March 11, 2015. Sincerely, 5'". Barry S. Allen Vice President, Nuclear SetVices dmfn/50465913-3 Enclosures cc: Diablo Distribution cc:/enc: Marc L. Dapas, NRC Region IV Administrator Dan H. Dorman, NRC/NRR Director Thomas R. Hipschman, NRC, Senior Resident Inspector Siva P. Lingam, NRR Project Manager A member of the STARS (Strategic Teaming and Resource Sh11ring) Alliance Callaway
• Diablo Canyon
• Palo Verde
• Wolf Creel1 PG&E Letter DCL-15-035 Pacific Gas and Electric Company Seismic Hazard Screening Report Diablo Canyon Power Plant Units 1 and 2 PG&E Letter DCL-15-035 Page 1 of 60 Pacific Gas and Electric Company Seismic Hazard and Screening Report Diablo Canyon Power Plant Units 1 and 2 Table of Contents Enclosure 1 PG&E Letter DCL-15-035 Page 2of60 1.0 Introduction ................................................................................................................ 4 2.0 Seismic Hazard Reevaluation .................................................................................... 8 2.1 Regional and Local Geology ........................................................................... 9 2.1.1 Bedrock Stratigraphy ............................................................................ 9 2.1.2 Tectonic Setting .................................................................................. 10 2.1.3 Significant Faults ................................................................................ 10 2.1.4 Site Geology ....................................................................................... 12 2.2 Probabilistic Seismic Hazard Analysis ........................................................... 15 2.2.1 Probabilistic Seismic Hazard Analysis Results ................................... 15 2.2.2 Base Rock Seismic Hazard Curves .................................................... 17 2. 3 Site Response Evaluation ............................................................................. 20 2.3.1 Description of Subsurface Material ..................................................... 21 2.3.2 Development of Base Case Profiles and Nonlinear Material Properties ........................................................................................... 25 2.3.3 Randomization of Base Case Profiles ................................................ 28 2.3.4 Input Spectra ...................................................................................... 28 2.3.5 Methodology ....................................................................................... 28 2.3.6 Amplification Functions ....................................................................... 29 2.3.7 Control Point Seismic Hazard Curves ................................................. 32 2.4 Control Point Response Spectra ................................................................... 33 3.0 Plant Design, Licensing, and LTSP Evaluation Bases Ground Motions ................... 36 3.1 Description of Response Spectra Shapes ..................................................... 38 3.1.1 Double Design Earthquake Response Spectrum ............................... 38 3.1.2 1977 Hosgri Earthquake Response Spectrum .................................... 40 3.1.3 Long Term Seismic Program Earthquake Spectrum ........................... 42 3.2 Control Point Elevation .................................................................................. 44 4.0 Screening Evaluation ............................................................................................... 46 4.1 Risk Evaluation Screening (1to10 Hz) ......................................................... 46 4.2 High Frequency Screening(> 10 Hz) ............................................................ 46 4.3 Spent Fuel Pool Evaluation Screening (1to10 Hz) ..................................... 47 5.0 Interim Evaluation .................................................................................................... 48 5.1 Expedited Seismic Evaluation Process ......................................................... 51 PG&E Letter OCL-15-035 Page 3of60 5.2 Walkdowns to Address NRC Fukushima NTTF Recommendation 2.3: Seismic .......................................................................................................... 51 6. O Conclusions ............................................................................................................ 53 7.0 References ............................................................................................................... 54 7. 1 Electric Power Research Institute .................................................................. 54 7.2 Pacific Gas and Electric Company ................................................................ 54 7.3 United States Nuclear Regulatory Commission ............................................. 55 7.4 Nuclear Energy Institute ............................................................................... 58 7.5 Other ............................................................................................................. 58 List of Appendices No. of Pages Appendix A-Additional Seismic Hazard Curve Data ......................................................... 13 Appendix B-Long Term Seismic Program Seismic Margin Spectrum ................................ 9 Appendix C-PPRP Endorsements ................................................................................... 18 1.0 Introduction Enclosure 1 PG&E Letter DCL-15-035 Page 4of60 Following the accident at the Fukushima Daiichi nuclear power plant resulting from the March 11, 2011, Great Tohoku Earthquake and subsequent tsunami. the Nuclear Regulatory Commission (NRC) established a Near Term Task Force (NTTF) to conduct a systematic review of NRC processes and regulations and to determine if the agency should make additional improvements to its regulatory system. The NTTF developed a set of recommendations intended to clarify and strengthen the regulatory framework for protection against natural phenomena. Subsequently, on March 12, 2014, the NRC issued a request for information letter under Title 10, "Energy," of the Code of Federal Regulations, Part 50, "Domestic Licensing of Production and Utilization Facilities," Section 50.54, "Conditions of Licenses, Subsection (f), "Request for Information," (March 12, 2012 10 CFR 50.54{f) letter). to assure that these recommendations are addressed by all United States nuclear power plants (NRC 2012). The March 12, 2012 10 CFR 50.54(f) letter requests that licensees and holders of construction permits under 10 CFR 50 reevaluate the seismic hazards at their sites against present-day NRC requirements. Depending on the comparison between the reevaluated seismic hazard and the current design/licensing basis, the result is either no further risk evaluation or the performance of a seismic risk assessment. Risk assessment approaches acceptable to the NRC staff include a seismic probabilistic risk assessment (SPRA), or a seismic margin assessment (SMA). Based upon the risk assessment results, the NRC staff will determine whether additional regulatory actions are necessary. This report provides the information requested in items (1) through (7) of the "Requested Information" section and Attachment 1 of the 10 CFR 50.54(f) letter pertaining to NTTF Recommendation 2.1 (NRC 2012) for Diablo Canyon Power Plant (DCPP), located in San Luis Obispo County, California. In providing this information, Pacific Gas and Electric Company (PG&E) followed the guidance provided in Electric Power Research Institute (EPRI) Technical Report No. 1025287, "Seismic Evaluation Guidance: Screening, Prioritization, and Implementation Details (SPID) for the Resolution of Fukushima Near-Term Task Force Recommendation 2.1: Seismic" (EPRI 2013a). The original geologic and seismic siting investigations for DCPP predate the issuance of Appendix A, "Seismic and Geologic Siting Criteria for Nuclear Power Plants," to 10 CFR 100, "Reactor Site Criteria" (NRC 1973). The double design earthquake (ODE), which the NRC directed PG&E to use for the response to the March 12, 2012 10 CFR 50.54(f) letter1, was originally developed using specific criteria and methods, and is used for the design of Design Class I structures, systems, and components, where Design Class I is DCPP's As stated in the NRC's letter to PG&E dated October 12, 2012 (NRC 2012c), "for the purposes of the response to the March 12, 2012 request for information. the NRC statt expects PG&E to use the DDE for comparison with the reevaluated seismic hazard GMRS."

2 Enclosure 1 PG&E Letter DCL-15-035 Page 5of60 equivalent to Seismic Category I, as defined in NRC Regulator Guide 1.29, "Seismic Design Classification" (NRC 1978). In addition, the seismic design of OCPP includes the 1977 Hosgri earthquake (HE). The 1977 HE, which has significantly larger ground motions than the ODE, is also used for design and evaluation of Design Class I structures, systems, and components. Finally, in response to License Condition 2.C.(7) of the DCPP Unit 1 operating license, the Long Term Seismic Program (L TSP) earthquake (L TSPE) was developed. The L TSPE was used for DCPP's prior SPRA and SMA (1988 L TSP Final Report, PG&E 1988). In response to the NRC's March 12, 2012 10 CFR 50.54(f) letter. and following the guidance provided in the screening, prioritization, and implementation details (SPID)2 (EPRI 2013a) and a Senior Seismic Hazard Analysis Committee (SSHAC) process established by the NRC for western United States plants. a seismic hazard reevaluation was performed for OCPP. This included development of DCPP*specific ground motion response spectrum (GMRS). Consistent with the NRC letter dated February 20, 2014, (NRC 2014) the seismic hazard reevaluations presented herein are being performed to beyond current design/licensing basis requirements for OCPP. Therefore, the results do not call into question the operability or functionality of structures, systems, and components and are not reportable pursuant to 10 CFR 50.72, "Immediate Notification Requirements for Operating Nuclear Power Reactors," or 10 CFR 50.73, "Licensee Event Report System." The GMRS was developed through the performance of a SSHAC Level 3 seismic source characterization study and a SSHAC Level 3 ground motion characterization study, in accordance with NUREG-2117, "Practical Implementation Guidelines for SSHAC Level 3 and 4 Hazard Studies," (NRC 2012b). In addition, a site-specific amplification study was performed. A copy of the participatory peer review panels (PPRP) closure letters for seismic source characterization and the ground motion characterization (GMC) is provided in Appendix C. The GMC closure letter found that the DCPP SSHAC meets the expectations for a SSHAC Level 3 study but requested that additional technical justification be provided regarding the application of the directivity component of the GMC model to the DCPP site. The SSHAC technical integration team provided a response to the PPRP request (see Appendix C). PG&E will submit the resolution of the PPRP identified request as soon as it is completed. Note: It has been recognized. and acknowledged by the NRC in public meetings (NRC 2014c and NRC 2014d), that the guidance provided in the SPID is more aligned with the seismic hazard studies associated with central and eastern United States plants, while SSHAC studies, performed in accordance with NUREG-2117 (NRG 2012b), and site-specific amplification studies, utilizing more up-to-dale, modern day methodologies. are appHcable to western United States plants. PG&E Letter DCL-15-035 Page 6 of 60 OCPP's screening evaluation of the GMRS, performed in accordance with SPID Figure 1-1, indicates that the GMRS exceeds the DOE in the 1to10 Hz frequency range. Therefore, DCPP screens-in for a seismic risk evaluation per the requirements of the SPID. PG&E will perform a SPRA in accordance with the EPRI guidance (EPRI 2013a) and the schedule as defined in NEl's letter to the NRC, dated April 9, 2013 (NEI 2013) and confirmed in NRC's letter, dated May 7, 2013 (NRC 2013). In accordance with the NRC's February 20, 2014 request for supplemental information from plant's that screen-in for a seismic risk evaluation (NRC 2014)! PG&E has performed an interim evaluation to address the seismic safety of DCPP. This interim evaluation compared the GMRS to the design/licensing basis 1977 HE spectrum and to the results of the L TSP seismic margin evaluation. This comparison demonstrated that there is reasonable assurance that DCPP's safety related structures. systems, and components will continue to perform their intended safety function if subjected to the ground motions at the newly developed GMRS levels. PG&E's letter to the NRC dated April 29, 2013 (PG&E 2013d), indicated that the expedited seismic evaluation process (ESEP) would be implemented for DCPP in accordance with EPRI Technical Report No. 3002000704, "Seismic Evaluation Guidance: Augmented Approach for the Resolution of Fukushima Near-Term Task Force Recommendation 2.1: Seismic" (EPRI 2013b). However, as noted above, the interim evaluation already demonstrates DCPP's seismic safety while an updated/upgraded SPRA is being developed. No additional insights will be gained for DCPP from the implementation of the ESEP. PG&E concludes that only a SPRA will be performed, rather than the implementation of an ESEP, such that the critical skilled resources can be devoted towards an update/upgrade of the SPRA. The SPRA. which includes the high-frequency confirmation, will be performed in accordance with the EPRI guidance (EPRI 2013a) and the schedule as defined in NEl's letter to the NRC, dated April 9, 2013 (NEI 2013) and confirmed in NRC's letter, dated May 7, 2013 (NRC 2013). PG&E's spent fuel pool (SFP) screening evaluation indicates that the GMRS exceeds the DCPP ODE in the 1 to 10 Hz frequency range. Therefore, DCPP screens-in for further review of the SFPs as required by the SPID. PG&E also performed an interim evaluation to address the seismic safety of the SFPs, which are located in the fuel handling area of the auxiliary building. Comparing the GMRS with the design/licensing basis 1977 HE spectrum and the L TSP seismic margin shows that the auxiliary building has a significant margin beyond the GMRS. Therefore, there is reasonable assurance that DCPP's SFPs will maintain their structural integrity if subjected to the ground motions at the newly developed GMRS levels. As indicated in PG&E's letter dated April 29. 2013 (PG&E 2013d), PG&E will perform additional evaluations of the SFPs in accordance with the EPRI guidance (EPRI 2013a) and the schedule as defined PG&E Letter DCL-15-035 Page 7of60 by the NEl's letter to the NRC, dated April 9, 2013 (NEI 2013) and confirmed in the NRC's letter dated May 7, 2013 (NRC 2013). 2.0 Seismic Hazard Reevaluation Enclosure 1 PG&E Letter DCL-15-035 Page 8 of 60 DCPP is located on the central California coast, approximately 19 kilometers (km) (12 miles (mi.)) west of San Luis Obispo, California (Figure 2.0-1). The plant is on the southwestern margin of the Irish Hills, an area of moderate relief bordered by Morro Bay on the north, San Luis Obispo Bay on the south, and Los Osos Valley on the east. The Irish Hills are the northwestern part of the San Luis Range, which trends approximately west-northwest/east-southeast and separates the Santa Maria River Valley to the south from the Los Osos and Edna valleys to the north . ...... ... .... _ '*'\* Pacific Ocean EXPlANATION .-.---* -Stginirlcanl faults -Other laults I Ouacernary I Tertiary i-Pie* Tertiary. mostly Mesozoic N O 2 4 A :-S mi. ** 111Af'*v*,o1 >bin Sal'*.d l*.):u;,, 0 Figure 2.0-1: Simplified Geology and Faults in DCPP's Vicinity PG&E Letter DCL-15-035 Page 9of60 DCPP's site region is within the broad boundary between the Pacific and North American tectonic plates. The majority of relative motion between the plates is accommodated by the right-lateral strike-slip San Andreas Fault Zone (SAFZ), located approximately 80 km (50 mi.) northeast of DCPP. Lesser rates of boundary deformation are accommodated by faults and folds in the coastal and offshore areas around the site. Historical earthquakes in the DCPP region have been moderate to large. The largest ground motion recorded at the site is a peak ground acceleration (PGA) (horizontal) of 0.042 g from the 2003 moment magnitude (M) 6.5 San Simeon earthquake. This ground motion is significantly lower than the ground motions from the design, licensing, and evaluation basis earthquakes (see Section 3.0 for definitions: a) Design Earthquake (OE}: An earthquake having a horizontal PGA of 0.20g. b) Double Design Earthquake (DOE): The ODE is defined as twice the DE and is an earthquake having a horizontal PGA of 0.40 g. The NRC staff requested that PG&E use the DOE for the GMRS comparison (NRC 2012c). c) 1977 Hosgri Earthquake (HE): DCPP's highest-level design/licensing basis earthquake having a horizontal PGA of 0.75 g. d) 1991 Long Term Seismic Program Earthquake (L TSPE): OCPP's review level earthquake associated with the SPRA and SMA, having a horizontal PGA of 0.83 g. 2.1 Regional and Local Geology Bedrock in OCPP's vicinity includes highly deformed Mesozoic and Cenozoic sedimentary and volcanic rocks. Foundations of principal plant buildings are founded directly on volcaniclastic rocks of the Miocene Obispo Formation (Fm.). 2.1.1 Bedrock Stratigraphy Basement rocks exposed in the central California coastal region generally consist of Jurassic to Cretaceous Franciscan Complex rocks (primarily melange, metavolcanics, ophiolite, and serpentine) faulted against Cretaceous marine arkosic to lithic sandstone (Figure 2.0-1). Overlying basement rocks in OCPP's vicinity are a sequence of Cenozoic sedimentary and volcanic rocks deposited in fault-bounded, marine to coastal sedimentary basins. Faulted and folded strata of the Pismo basin are located beneath the DCPP site and much of the San Luis Range in the Pismo syncline PG&E Letter DCL-15-035 Page 10of60 (Figure 2. 0-1). The base of the Pismo basin Cenozoic sequence consists of the Oligocene Rincon shale and Vaqueros sandstone, which unconformably overlie the Mesozoic basement rocks. Overlying the Oligocene strata are the Miocene Obispo and Monterey Formations and the Miocene to Pliocene Pismo Fm.. The Obispo Fm. consists of resistant zeolitized tuft, tuffaceous marine sandstone, and diabase, whereas the Monterey and Pismo Formations consist of nonvolcanic marine siltstone, chert, and porcelaneous shale. 2.1.2 Tectonic Setting DCPP is located within a tectonic region of distributed transpressional dextral shear bordering the eastern margin of the Pacific Plate. The SAFZ, located approximately 80 km (50 mi.) northeast of DCPP, accommodates most of the relative motion between the Pacific Plate and the Sierra Nevada-Great Valley microplate. West of the SAFZ, an additional component of relative Pacific-Sierra Nevada plate motion is accommodated by slip on various Quaternary faults bounding crustal blocks and, to a lesser extent, by deformation within the blocks. In DCPP's site vicinity, the San Luis Range and adjacent valleys and ranges are underlain by crustal blocks that together make up a larger tectonic element called the Los Osos domain (Lettis et al 2004). The Los Osos domain is a triangular structural region bounded by three Quaternary faults: the northwest-striking lateral oblique Oceanic-West Huasna fault zone on the east: the left-lateral oblique Santa Ynez River fault on the south; and the striking right-lateral Hosgri-San Simeon fault zone on the west (Figure 2.0-1). Individual blocks within the Los Osos domain are bounded by northwest-striking reverse, oblique, and strike-slip fault zones. Crustal shortening within the Los Osos domain is accommodated primarily by reverse faulting along the block margins, producing alternating uplifted and down-dropped blocks (Lettis et al 1994, Lettis et al 2004). Additional crustal shortening and dextral shear is accommodated by a combination of reverse, oblique, and strike-slip faulting between and within blocks and by block rotation. OCPP is located within the San Luis-Pismo block, which is topographically expressed by the San Luis Range. The San Luis-Pismo block is bounded by the Los Osos fault zone on the north, by the faults of the "southwestern boundary zone" (including the San Luis Bay, Wilmar Avenue, Los Berros, and Oceano fault zones) on the south, and by the Hosgri fault zone on the west (Figure 2.0-1). 2.1.3 Significant Faults Faults that contribute significantly to the seismic hazard at DCPP include the Hosgri fault zone, the Los Osos fault zone, the San Luis Bay fault within the southwestern boundary zone, and the Shoreline fault (Figure 2.0-1 ). 2.1.3.1 Hosgri Fault Zone Enclosure 1 PG&E Letter DCL-15-035 Page 11of60 The Hosgri fault zone is the southern part of the larger 410 km (255 mi.) long San Gregorio-San Simeon-Hosgri fault system (Figure 2.0-1 ). The location of the offshore Hosgri fault zone is known primarily from the interpretation of marine seismic-reflection data. The fault zone consists of multiple vertical to steeply dipping traces in a zone up to 2.5 km (1.6 mi.) wide directly offshore of OCPP and forms the western termination of the offshore bedrock platform associated with uplift of the San Luis-Pismo block (PG&E 1988, PG&E 1990, PG&E 2011; Willingham et al 2013). Focal mechanisms and the distribution of seismicity along the Hosgri fault zone document nearly pure strike slip on a near vertical to steeply east-dipping fault to a depth of 12 km (7.5 mi.) (Mclaren and Savage 2001; Hardebeck 2010, Hardebeck 2013). Slip rate studies provide an estimate of approximately 1 to 3 millimeters per year (mm/year) of right-lateral slip on the Hosgri fault near OCPP (Hanson and Lettis 1994; Johnson et al 2014; PG&E 2014, Chapter 3). These rates are consistent with regional geodetic data showing approximately 1 to 3 mm/year of plate-margin lateral shear in the region west of the West Huasna fault (OeMets et al 2014). 2.1.3.2 Los Osos Fault Zone The Los Osos fault zone borders the northeastern margin of the San Luis Range (Figure 2.0-1). The south to southwest-dipping fault generally separates the uplifting San Luis-Pismo block from the subsiding or southwest-tilting Cambria block to the northeast (lettis et al 1994). As described by Lettis and Hall (Lettis and Hall 1994), the fault zone is a 2 km (1.2 mi.) wide system of discontinuous, sub-parallel and en-echelon fault traces extending from an intersection with the Hosgri fault zone in Estero Bay on the north to an intersection with the West Huasna fault southeast of San Luis Obispo, for a distance of over 55 km (34 mi.). The slip rate of this reverse to reverse-oblique fault is estimated to be approximately 0.2 to 0.4 mm/year (PG&E 2015). 2.1.3.3 San Luis Bay Fault within the Southwestern Boundary Zone The southwestern margin of the San Luis Range is bordered by a complex zone of late Quaternary reverse, oblique-slip and possibly strike-slip faults (Figure 2.0-1). These faults in aggregate separate the San Luis-Pismo block from the subsiding Santa Maria Valley block to the southwest (Lettis et al 1994). The zone of faults is collectively called the southwestern boundary zone, and is 4 to 10 km (2.5 to 6.2 mi.) wide and over 60 km (30 km) long (Lettis et al 1994; Lett1s et al 2004). The faults generally strike west-northwest and dip moderately to steeply to the northeast. Principal structures within this fault zone include the San Luis Bay, Wilmar Avenue, Los Berros, Oceano, and Nipomo faults. The cumulative rate of vertical separation across the fault zone, based primarily on PG&E Letter Page 12 of 60 deformation of the marine terrace sequence along the coast and southwest side of the range onshore, ranges from about 0.1 to 0.3 mm/year with each fault generally having a rate of 0.04 to 0.1 mm/year (Lettis et al 1994). Within the southwestern boundary zone, the north-dipping, reverse-slip San Luis Bay fault lies closest to DCPP. The fault has an estimated slip rate of approximately 0.1 to 0.3 mm/year (PG&E 2015). 2.1.3.4 Shoreline Fault Zone The Shoreline fault was originally identified from a seismicity lineament trending approximately N60°W to N70°W offshore and parallel to the coast in the vicinity of DCPP (Hardebeck 2010) (Figure 2.0-1 ). Mapping of the Shoreline fault zone at and near the seafloor was performed by PG&E (PG&E 2011; PG&E 2014, Chapters 2 and 3). The hypocentral distribution of seismicity forms a nearly vertical alignment that extends to a depth of about 8 to 10 km, and focal mechanisms indicate the fault is right-lateral strike slip (Hardebeck 2013). Hardebeck (Hardebeck 2013) interprets that to the north the Shoreline fault zone likely connects with the Hosgri fault zone, a result that is consistent with PG&E (PG&E 2014, Chapter 2). Within San Luis Obispo Bay and south of the seismicity lineament, high-resolution 30 seismic data show that the Shoreline fault zone displaces sediments of late Quaternary age providing clear geologic evidence of late Quaternary fault activity (PG&E 2014, Chapter 3). The Shoreline fault zone has an estimated slip rate of approximately 0.03 to 0.15 mm/yr (PG&E 2015). 2.1.4 Site Geology The geology of DCPP's site area consists of Tertiary Obispo Fm. resistant tuff, volcaniclastic strata, and later-stage Obispo Fm. diabase that intruded into the Obispo Fm. volcaniclastics, Quaternary surficial deposits, and engineered fill (Figures 2.1.4-1 and 2.1.4-2). Older Cretaceous sandstone and Franciscan basement rocks are mapped on the seafloor approximately 500 meters (m) southwest of DCPP (Figure 2.1.4-1 ), and onshore along the coastline several km to the southeast (Figure 2.0-1; PG&E 2014, Chapter 9). Four map-scale Obispo Fm. sub-units, or lithofacies, are recognized within the DCPP site area. From oldest to youngest, these sub-units are as follows: a) Resistant, bedded to massive tuffaceous rocks. including possible "peperite," a near-source intrusive tuff (Tmor) b) Bedded, shaley siltstone with tuffaceous fine sandstone interbeds (Tmofc) c) Bedded, tuffaceous and dolomitized fine sandstone and siltstone (Tmofb) d) Massive to jointed diabase (Tmod). PG&E Letter DCL-15-035 Page 13 of 60 The diabase sub-unit intrudes all the other lithologies, and thus is the youngest (PG&E 2014, Chapter 9). Figure 2.1.4-1: Geologic Map of DCPP's Site Area from (PG&E 2014, Chapter 9) (Explanation of geologic units and symbols are shown on Figure 2.1.4-2) af 2" Qsw .,, c: ,_ ., Qts ;;;J 0 Qm Ou Ks KJf Geologic Units Artificial fill: fill ma1erial emplaced locally during construction and improvement activities. Shallow fills not shown: bedrock with trenches and excavation for power block shown; filled with al. Sand wave deposits, offshore: unlilhifled sheets of sand that form migrating marine dunes. Landslide deposits: unllthified masses of displaced bedrock and/or soil: may be active or inactive. Marine terrace deposits: unlithified to weakly lithified marine sand and gravel deposited above wave*cut platforms in the Pleistocene and commonly overlain by alluvial fan and cotluvial deposits. Quaternary deposits, undifferentiated: unlitflified silt, sand. and/or gravel; consists of alluvial fan, fluvial terrace. alluvial and colluvial deposits. Tmod Tmofb Tmok -rmor Obispo Formation, diabase: brown, aphanilic to phanetitic. intrus:ve in dikes and sills. Obispo Formation, fine.grained sub-member b: Bedded tuffaceous, dolomitic, fine to medium-bedded siltstone and fine sandstone. Obispo Formation, fine-grained sub-member c: Bedded shale and siltstone. very fine bedded silly shale with medium bedded. dolomitic siltstone intcrbeds. Obispo Formation. resistant member: Bedded to massive zeolitic tuft. tuft breccia, and tuffac:eous sandstone. Cretaceous Sandstone: arkosic to lithic sandstone, brown. bedded, well-lithified, fine-to course-grained. includes minor shale. Franciscan Complex, undifferentiated 0.. ::! (!) -0 c ., m .!i c. c. .,, E ., ::l .Q > c. E e 11. Enclosure 1 PG&E Letter DCL-15-035 Page 14 of 60 Geologic Structures ., Contact: solid where well located. long dash where approximate, short dash where inferred. dotted where concealed, queried where uncertain. -.. H__!vl .* -* * -* * -*

• Boundary (contact) between Obispo diabase and tuffaceous rocks interpreted from helicopter magnetic survey (PG&E. 2C11 ). Line may not follow exact contact of reek at surface. --t----.. --t-----------***';I*** A A. Syncline: dashed where approximate, dotted where concealed. An ow poinls in direction of plunge. Anticline: dashed where approximate, dotted where concealed. Arrow points in direction of plunge. fault: solid where well located. ror.g dash wt'lere approximate, short dash where inferred. dotted where concealed. queried where uncertain. Geographical Features Roads Buildings Coastline (white line) at mean lower low waler (approximate sea level) Vp Cross sections (Figure 2.3.1-3) Figure 2.1.4-2: Explanation of Geologic Units and Symbols for Figure 2.1.4-1 PG&E Letter DCL-15-035 Page 15of60 DCPP is underlain by gently to steeply dipping sub-unit Tmofb, the bedded, tuffaceous and dolomitized fine sandstone and siltstone (Figure 2. 1. 4-1). Directly adjacent to the foundation area, this volcaniclastic sub-unit is locally unconformably overlain by Quaternary surficial units including alluvial fan sediments (mapped as part of undifferentiated Quaternary deposits (Ou)) and marine terrace deposits (Om) (Figure 2.4.1-1 ). Additionally, engineered fill (af) underlies portions of the roadways and infrastructure at the DCPP site. 2.2 Probabilistic Seismic Hazard Analysis 2.2.1 Probabilistic Seismic Hazard Analysis Results In accordance with the March 12, 2012 50.54(f) letter (NRC 2012) a site-specific probabilistic seismic hazard assessment was completed for DCPP's site. The assessment used an updated seismic source characterization (SSC) model and an updated GMC model as basic inputs. The SSC and GMC studies were undertaken to fulfill the NRC requirement that PG&E conduct a probabilistic seismic hazard assessment using SSHAC Level 3 procedures for DCPP. as specified by the NRC (NRC 2012). Thus, the SSC and GMC models were developed using processes that are appropriate for a SSHAC Level 3 study, as described in NUREG/CR-6372 (NRC 1997), and the detailed implementation guidance provided in NUREG-2117 (NRC 2012b). Both the SSC and GMC models represent new or "replacement" models according to the definitions and instructions in NUREG-2117. The SSC model describes the future earthquake potential (e.g., magnitudes, locations, and rates) for the region surrounding the DCPP site, and the GMC model describes the distribution of the ground motion as a function of magnitude, style of faulting, source-to-site geometry and reference site condition. The DCPP SSC model includes fault and areal seismic sources out to and beyond the 320 km (200 mi.) DCPP site region. The SSC model focuses on those sources that contribute most to hazard at DCPP: the Hosgri, Los Osos, San Luis Bay, and Shoreline fault sources, called the primary fault sources, and the local areal source zone, which accounts for earthquakes that occur near DCPP but off the recognized fault sources (PG&E 2015). Uncertainty and variability in earthquake ruptures that are modeled to occur on the primary and adjacent fault sources consider alternative fault geometries and fault slip rates, and include alternative connections of adjacent fault sections across which earthquake ruptures may occur. New elements in the SSC model compared to prior SSC models include fault magnitude probability density functions that allow a fault source to rupture during more common, characteristic earthquakes and rare but permissible multi-fault, maximum earthquakes. The largest earthquake considered in the SSC model is a magnitude M 8.5 on the Hosgri fault source, representing an extremely rare, but plausible, rupture between offshore Point Arguello south of DCPP and the Mendocino Triple Junction offshore Cape Mendocino in northern California. The postulated rupture would include the PG&E Letter DCL-15-035 Page 16 of 60 entire 41 O km (255 mi.) length of the Hosg ri-San Simeon-San Gregorio fault zone and an additional 330 km (205 mi.) of the northern San Andreas fault north of San Francisco. More common characteristic earthquake magnitudes on the fault sources range between M 6 and M 7.3, with strike-slip, reverse, and reverse-oblique slip senses occurring between approximately 1 O and 1 km (6 and 0.6 mi.) from DCPP at closest source-to-site distances. Another new element of the DCPP SSC model is the inclusion of uncertainty in the time-dependent nature of the earthquake occurrence rate. Instructions for implementing the SSC model are in the SSC hazard input document. Full documentation of the DCPP SSC model and the SSHAC Level 3 process is contained in the DCPP SSC Report (PG&E 2015) and is available online at www.pge.com/dcpp-ltsp. The DCPP GMC model is derived as part of a regional study addressing the ground motion characterization for two sites located in the Southwestern United States (SWUS) (DCPP and Palo Verde Nuclear Generating Station in Arizona), for a common reference site condition with Vs303 of 760 meters per second (m/s) and kappa of 0.041 seconds (sec) (GeoPentech 2015). The DCPP GMC model for the median is derived from published ground motion prediction equations wt1ich are then reparameterized into models that use a common functional form. With a set of models based on a common functional form, the covariance structure of the model coefficients can be estimated and sampled to produce a large number of alternative ground motion prediction equations (GMPEs). This large space of ground motion models is then discretized into a smaller number of representative ground motion models. A key advantage of this approach is that the weights on the alternative models represent probabilities of the ground motion models based on the discretization of the ground motion model space. The ground motion models are optimized for large magnitudes (M 5.5 to M 7.5) strike slip and reverse events at short distances(< 10 km) that dominate the hazard at DCPP. The hanging-wall effects are captured from a suite of wall adjustment models derived from the hanging-wall scaling in the existing NGA-West2 RRuP-based GMPEs. In addition to the empirically-based models, finite fault simulations were used for three purposes: (1) to constrain the hanging-wall scaling; (2). to provide an alternative data set of large magnitude near-fault ground motions for use in the evaluation of the weights for the ground motion models; and (3) to constrain the scaling of ground motions for complex and splay ruptures that are not well constrained in the empirical data sets (complex rupture refers to a case with significant (i.e., > 15 degrees) changes in rake and dip along fault strike, and splay rupture refers to a case with two faults rupturing together). The GMC model for the standard deviation for DCPP uses the partially non-ergodic approach (Al Atik et al, 201 O) in which the variability of the average site-specific amplification, not captured in the simple site scaling in the GMPEs, is removed from the within-event standard deviation. This approach provides a consistent V530 is defined as the average shear-wave velocity in the first 30 m of subsoil/rock. PG&E Letter DCL-15-035 Page 17 of 60 method for combining the uncertainty in the site-specific site amplification with the aleatory variability of the ground motion models. Instructions for implementing the GMC model are in the GMC hazard input document. Full documentation of the DCPP GMC model and the SSHAC Level 3 process is contained in the southwestern United States GMC report (GeoPentech 2015) which is available online at www.pge.com/dcpp-ltsp. 2.2.2 Base Rock Seismic Hazard Curves For the central and eastern United States (CEUS) sites, the base rock condition is a hard rock site condition (shear-wave velocity of 2800 m/s) (EPRI 2013c). For the western United States, the ground motion models are not well constrained for hard-rock conditions. Therefore, a reference rock condition for soft-rock (Vs30 = 760 m/s) is used for the base rock hazard calculation. The hazard is computed using a minimum moment magnitude of 5.0. All sources within 320 km (200 mi.) of DCPP are included in the hazard calculation, as required by Regulatory Guide 1.208 (NRC 2007). The aleatory variability is modeled using the single-station sigma approach (Al-Atik et al 2010), which removes the systematic site terms from the traditional total standard deviation. Using the single-station sigma approach requires that the epistemic uncertainty in the site terms be included. The epistemic uncertainty in the site term at each spectral frequency is included through the standard error of the empirical site term. The hazard curves by seismic source are shown in Figures 2.2.2*1 and 2.2.2-2 for 1 and 10 Hz spectral acceleration, respectively. The digital data associated with these figures are listed in Appendix A. The sources that contribute at least 5 percent to the total hazard at 1 x 10*3 hazard level are shown individually. Only the sources that come within 15 km (9 mi.) of DCPP contribute significantly (at least 5 percent) to the total hazard at any spectral period for hazard levels of 1 x 10'3 or less. The total hazard for seven frequencies is shown in Figure 2.2.2-3.

DCPP: 1 Hz 1.E-01 I ---*---* _ __I _____ .-------* I 1.E-02 1.E-03 1.E-05 -f----1.E-06 -1 I I I 1.E-07 -!1---------** ---0.01 0.1 Enclosure 1 PG&E Letter DCL-15-035 Page 18 of 60 -Total --Hosgri fault * ...... San Luis Bay fault -*--Los osos fault -----Shoreline fault --San Andreas fault -* -Other connected faults --*Other regional faults -*

• Local source zone Regional and Vicinity source zones 1 10 Spectral Acceleration (g) Figure 2.2.2-1: Reference Rock Hazard by Source for 1 Hz Spectral Acceleration

.. Ill N Ill ::c (ii ::I c c c:( 1.E-01 1.E-02 1.E-03 1.E-04 1.E-05 . l.E--06 r 1.E-07 *-----------* 0.1 1 DCPP: 10 Hz \ . -\.. Enclosure 1 PG&E Letter DCL-15-035 Page 19of60 -Total --Hoscri fault ......

• San Luis Bay fault ---Los Osos fault ----*Shoreline fault --San Andreas fault -* -Other connected faults -*
• Local source zone
• Regional and Vicinity sourc:e zones *--------------*------------* 10 100 Spectral Acceleration (g) Figure 2.2.2-2: Reference Rock Hazard by Source for 10 Hz Spectral Acceleration "E is ra 1.E-02 1 1.E-03 r-Enclosure 1 PG&E Letter DCL-15-035 Page 20of60 --! -Mean (PGA) I -Mean (20 Hz) Mean (10 Hz) -Mean(SHz) Mean (2.5 Hz) Mean (1 Hz) Mean (O.S Hz) ::c 1.E*04 ra :I c 1.E-05 \ ** .. *---------------1.E*06 ***r----------------0.1 l Spectral Acceleration (g) 10 Figure 2.2.2-3: Reference Rock Mean Hazard for PGA and 20, 10, 5, 2.5, 1, and 0.5 Hz Spectral Acceleration 2.3 Site Response Evaluation 4 The traditional approach for site response is to develop analytical models for the site amplification relative to the reference rock site condition used for computing the hazard. An alternative empirical approach is used for DCPP to account for the recorded ground motion data at DCPP4. This approach relies on the observed ground motions at the site to constrain the site amplification rather than analytical models. When site specific data are available, the empirical approach is preferred over analytical modeling. The epistemic uncertainty due to the limited number of recordings is taken into account. DCPP's seismic instrumentation system, described in Section 3. 7.4 of the DCPP UFSAR (PG&E 2013), includes several free-field recording instruments. Ground motion records from instrument nos. ESTA27 and ESTA28 (see Figure 2.3.2-4 for instrument locations) are used as input to the site response evaluation. PG&E Letter DCL-15-035 Page 21of60 The empirical site term represents the difference from the site amplification expected for a reference Vs30 of 760 m/s and the observed site amplification. It is estimated from recorded data after removing the average source and path terms from the observed ground motions at DCPP. The control point for DCPP is set at one of the free-field recording instruments (ESTA28). This control point is at elevation 26 m (85 feet (ft)). The empirical site response approach estimates the site amplification at the control point. To estimate the ground motions at other locations as part of the soil-structure interaction analyses, a three-dimensional (30) site response will be conducted in a separate study. The 30 site response will be used to compute the factors to scale the control point ground motions to other locations accounting for the lateral differences in the 30 velocity structure across the DCPP site. Equivalent one-dimensional (1 D) profiles will be developed that capture the range of the amplification from the alternative 30 velocity models in order to define the inputs for the soil-structure interaction analyses. 2.3.1 Description of Subsurface Material The volcaniclastic Tmofb subunit of the Tertiary Obispo Fm. is mapped to the bottom of the four deepest boreholes in the DCPP foundation area, as well as two deep boreholes located about 305 m (1000 ft) east-northeast of the northeastern corner of the DCPP foundation. Directly adjacent to the Tmofb subunit are other subunits of the Obispo Fm. as shown on Figure 2.1.4-1. There is considerable rock velocity variability observed in the high-resolution 30 tomographic 5 km by 5 km (3 mi. by 3 mi.) area containing the DCPP structure foundations (PG&E, 2014, Chapter 10). A substantial portion of this variability appears to be related to volcanic intrusion and alteration of the diabase subunit. Characteristics of acoustic (Vp) seismic velocities estimated using 30 tomography from active-source seismic data collected in 2011 and 2012 (PG&E 2014, Chapter 10) are briefly discussed below and then related to first-order geology in the remainder of this section. The 2011-2012 active seismic acoustic-wave (Vp) travel-time and 2013 gravity data were inverted to estimate 30 Vp in a large area containing DCPP (PG&E 2014, Chapter 10). Several additional 30 Vp inversions used successively finer grid spacing and progressively smaller maximum offset arrival time data to estimate more detailed 30 Vp in the 5 km by 5 km (3 mi. by 3 mi.) volume containing DCPP. The active seismic data were also processed to produce prestack depth-migrated 30 seismic velocity volumes containing DCPP. There is a correlation between 30 Vp and geologic units (Table 2.3.1-1). The lowest seismic velocities are associated with Quaternary surficial units and the shallowest weathered regions in Tertiary rocks beneath PG&E Letter DCL-15-035 Page 22of60 surficial units. The highest seismic velocities are associated with massive diabase. Seismic velocities in the top 300 m vary by more than a factor of 13 in DCPP's site area. Less than half this velocity range is represented by about a factor of three range in velocities between the slowest Quaternary surficial units (Vp = 0.5 kilometers per second (km/s)) and the top of competent weathered rock (Vp = 1.5 km/s). The remaining velocity variability of about a factor of four occurs within Tertiary Obispo Fm. rocks that comprise the entire rock portion of the DCPP foundation to about 300 m below sea level or more. Interpretation of 30 seismic-reflection data acquired in 2012 in a 30 migrated volume containing the DCPP foundation indicates that there is an unconformity at elevations deeper than 300 m below sea level that separates shallow Obispo rocks from either deeper older Obispo rocks or Cretaceous sandstone (PG&E, 2014, Chapter 8). Thus the entire rock portion of the 30 DCPP foundation velocity model likely consists entirely of Tertiary Obispo Fm. rocks beneath surficial deposits. PG&E Letter DCL-15-035 Page 23of60 Table 2. 3. 1-1: Generalized Irish H ii Is Vp-Geologic Un it Correlation Bin Color Vp (Figure (km/sec) (ft/sec) Geologic Unit(s) 2.3.1-1) Black 0.560 1,857 Dry soil Dark Blue 1.120 3,675 Dry soil-weathered rock Dark Green 1.676 5,512 Saturated soil-weathered rock Medium Typical Tertiary (all units except diabase), Green 2.235 7,349 weathered Ks and KJf, and KJf of the northern Irish Hills Light Green 2.794 9,186 Typical higher velocity Obispo Fm. except diabase, and KJf of the northern Irish Hills Light Blue 3.353 11,024 Typical Ks, fast Obispo Fm. (except diabase), and KJf of the northern Irish Hills Yellow 3.911 12,861 ] Typical near the top of KJf, zones around thin 1 diabase, and KJf of the northern Irish Hills Near maximum for KJf, low diabase, and Red 4.470 14,698 Monterey and Obispo Fm. in the hanging wall of the Edna fault KJf near large-scale diabase intrusions, thin Dark Red 5.029 16,535 diabase, and Monterey and Obispo Fm. near the Edna fault Purple 5.588 18,373 J Exclusively diabase Notes: Minimum velocity of the bin 1s listed. Ks= Cretaceous sandstone KJf =Franciscan complex . I The 3D Vp values and their correlative geologic units shown in Table 2.3.1-1 were developed by comparing 30 Vp values to observed geologic units throughout the Irish Hills. The table illustrates that, while there probably are unique correlations between velocity and geologic unit for the fastest and slowest velocities in the DCPP foundation area. intermediate velocities can correspond to several different rock types and geologic units of various ages that exist beneath the greater Irish Hills. Thus, seismic velocity does not, in general, uniquely distinguish one rock type or formation from another. For instance, the velocity bin of -2.2 to 2.8 km/sin Table 2.3.1 w1 captures Tertiary Monterey and lower-velocity Obispo Fm. rocks as well as weathered Cretaceous sandstone (Ks) and Franciscan rocks (KJf). Unweathered, massive Obispo diabase is likely the only high-velocity rock unit that has a unique velocity signature over its maximum velocity range of 5.5-6+ km/s (Table 2.3.1-1). Tabular and saucer-shaped high-velocity bodies are evident in east-west oriented Vp cross sections located beneath and to the north DCPP PG&E Letter DCL-15-035 Page 24 of 60 (Figures 2.1.4-1and2.3.1-1) and within the high-resolution 5 km by 5 km (3 mi. by 3 mi.) tomographic model where dense seismic travel-time measurements where obtained (PG&E 2014, Chapter 10). West A 300 200 :[ 100 c. .Q 0 iQ > Q) iii *100 -200 -300 0 0 0 0 0 0 0 0 0 -N .... "t B 300 200 'E 100 DCPP t -200 0 0 0 0 0 0 0 0 0 0 ,., <O .... 00 O> Distance (m) 0 0 0 -East 0 0 0 0 0 0 0 0 0 0 0 0 0 0 :! Vp (km/s; ftls) 0.560; 1857 1.120; 3675 1.676; 5512 2.235; 7349 ..* 2.794; 9186 3.353; 11024 3.911; 12861 4.470; 14698 5.029; 16535 5.588; 18373 Vp (km/s; ftls) 0.560; 1857 1.120; 3675 1.676; 5512 2.235; 7349 2.794; 9186 3.353; 11024 3.911; 12861 4.470; 14698 5.029; 16535 5.588; 18373 -300 +., ........... , ,,,.,..,, ......... ,,.,.., ,.,,..., .. = .. = .... = ................. ***"""* ........ ,,,...,,. **""'** ,.,.,,....,.,. **""'***** ...... , ..... "'"'""'*""'* '"""'",...,.' ,,..,.,,,,., ...... ,,.,...,,, .......... , Distance (m} Figure 2.3.1-1: Vp Cross Sections Showing High-Velocity (yellow to magenta) Saucer-Shaped Bodies (Vertical exaggeration is approximately 2: 1. Velocities listed correspond to the top of each color bin. See Figure 2.1.4-1 for cross-section locations) These high-velocity bodies have 30 shapes that are typically associated with saucer-shaped intrusive sills (PG&E 2014, Chapter 10). The shallow position of the saucer-shaped sills adjacent to, and beneath, some edges of DCPP's foundation area may in part explain observations of the diabase subunit exposed adjacent to the breakwater of intake cove (Figure 2.1.4-1 ), along the coastline southeast of DCPP, and offshore of OCPP (PG&E 2014, Chapter 9). PG&E Letter DCL-15-035 Page 25 of 60 2.3.2 Development of Base Case Profiles and Nonlinear Material Properties The traditional approach uses multiple base profiles and non-linear properties to capture the epistemic uncertainty in the site amplification. For the empirical site term approach used for DCPP, epistemic uncertainty is captured through the epistemic uncertainty of the empirical site terms rather than using uncertainty in the inputs to an analytical site response model. For DCPP, we use alternative 30 models to capture the epistemic uncertainty in the lateral variation of the ground motion across the DCPP site region. The alternative 30 velocity models were selected from a large suite of alternative models such that they appropriately capture the range of the amplification at the key structures. The epistemic uncertainty in the amplification at the control point ground motion is included in the uncertainty of the empirical site factors. To avoid double counting uncertainty, only the uncertainty in the lateral variations of the site amplification due to the alternative 30 velocity is included in the 30 site response evaluation. As an example, three alternative 30 models of the wave velocity are shown in Figures 2.3.2-1, 2.3.2-2, and 2.3.2-3. Figure 2.3.2-4 shows 1 D profiles at the control points based on the 30 models. Figure 2.3.2-1: 30 Perspective of Vs-Depth Cross Section Slices through the Amplification 30 Vs DCPP Site Model (Model 1 ). Location of Cross Section is Shown in Figure 2.3.2-4. PG&E Letter DCL-15-035 Page 26of60 Figure 2.3.2-2: 3D Perspective of Vs-Depth Cross Section Slices through the Amplification 3D Vs DCPP Site Model (Model 2). Location of Cross Section is Shown in Figure 2.3.2-4. Figure 2.3.2-3: 3D Perspective of Vs-Depth Cross Section Slices through the Amplification 3D Vs DCPP Site Model (Model 3). Location of Cross Section is Shown in Figure 2.3.2-4.

20 0 I -20 c 0 -40 llJ w -60 *80 *100 ---------ESTA27: midAmp Model ; -ESTA 28: miclAmp Model *, Turbine *-Unit I Unit l 400 600 800 1000 1200 1400 1600 1800 2000 Vs (m/s) Enclosure 1 PG&E Letter DCL-15-035 Page 27of60 180 160 140 I 120 -ro I : *so g 1 I I: I 1!0 \ I 20 . j i 0 800 -20 Figure 2.3.2-4: 1 D Velocity Model for the Control Point (ESTA 28) and Other Locations in the Plant Area 2.3.2.1 Shear Modulus and Damping Curves Shear-modulus curves and damping curves are not directly applicable to DCPP, since analytical modeling is not used. The non-linear site effects are implicitly included in the empirical GMPEs for Vs30 = 760 m/s. The non-linearity in the NGA-West2 GMPEs is generally consistent with the EPRI Peninsular Range shear-modulus curves and damping curves (Kamai et al 2014). In the Kamai et al 2014 model, there is no dependence of the site amplification on the rock ground motion level (e.g. no non-linearity) for Vs30 > 760 mis. The NGA-West2 GMPEs also have very weak or no rock ground motion level dependence on the sites amplification for V53o > 760 m/s. Therefore, the empirical site factors are applicable to high rock ground motion levels. 2.3.2.2 Kappa The kappa values are implied in the empirical GMPEs used to develop the ground motion model and in the site-specific recordings. The GMPEs used to develop the ground motion model have average (host) kappa of 0.041 sec (Appendix M of GeoPentech 2015). The issue for DCPP's empirical approach is the applicability of this host kappa to DCPP's site. The kappa for DCPP was PG&E Letter DCL-15-035 Page 28of60 evaluated using the spectral shape of the 2003 Deer Canyon earthquake (Appendix L of the 2011 Shoreline fault report (PG&E 2011)) and was found to be consistent with a kappa of 0.04 sec. Empirical evaluations of the kappa scale factors (Ktenidou and Abrahamson 2015) show that the dependence of the frequency ground motion residuals are not strongly correlated with kappa computed from the observed ground motions. They conclude that the estimated site kappa is correlated with other parameters, which limits the observed correlation of residuals and kappa. Therefore. the kappa from the empirical GMPEs used for the ground motion model is consistent with the DCPP site kappa and an adjustment for site-specific kappa or adding additional uncertainty for kappa is not warranted. 2.3.3 Randomization of Base Case Profiles Randomization of the base case profiles is not needed since DCPP is using the empirical site term approach. 2.3.4 Input Spectra An input spectrum is not required since DCPP is using the empirical site term approach. 2.3.5 Methodology The empirical site-term approach is used because site-specific empirical motion data are available at DCPP. These data provide the best information on the site response because they sample the actual conditions at DCPP. In particular. the data provide a better representation of the effects of the deeper structure (top 0.5-1 km) that are important to the kappa and to the low-frequency response. which may not be captured in the analytical modeling. A disadvantage of using site-specific empirical data is the limited number of recordings; however, this limitation is addressed by estimating the epistemic uncertainty in the site response factors based on the number of recordings and the global estimate of the standard deviation of site-specific site terms. The free-field recordings at DCPP (available from the Pacific Earthquake Engineering Research ground motion database) are used to estimate the specific effects on the ground motions relative to the reference-rock GMPEs. The ground motions at a site from a given earthquake reflect the event-specific source and attenuation effects in addition to the site-specific site effects. To isolate the site effects, the differences in the event-specific source and specific attenuation effects from the average effects captured in the GMPEs are removed. This is done by computing the mean residual at each spectral frequency over a subset of recorded ground motions from a representative distance range and then developing a source-specific estimate of the ground motion at DCPP by adding the mean residual to the median ground motion from PG&E Letter DCL-15-035 Page 29of60 each of the GMPEs. The mean residual for the selected data is different from the traditional event term used in developing GMPEs because it is for a limited distance range. This provides an estimate of not just the average source effect, but also the average path effect (difference from the distance scaling in the GMPEs). To avoid having the DCPP site effects influence the correction, the mean residual is computed without the DCPP data. Ground motions from the 2003 San Simeon and 2004 Parkfield earthquakes were selected for use in this evaluation. The 2003 Deer Canyon earthquake did not have enough recordings to constrain the mean event term independent of OCPP's recordings. Therefore, the recording from the 2003 Deer Canyon earthquake is not used in this evaluation. The mean residuals are computed for each of the five NGA-West2 GMPEs. Following the method used in the 2011 Shoreline fault report (PG&E 2011), the residuals are computed for eight recordings in the distance range of Oto 100 km (62 mi.) for the San Simeon earthquake and for 16 recordings in the distance range of 40 to 170 km (25 to 106 mi.) for the Parkfield earthquake to capture the event term in the relevant distance ranges (35 km (22 mi.) for San Simeon and 85 km (53 mi.) for Parkfield). This mean residual is used to adjust the West2 GMPEs to the event and distance specific values (e.g. remove average source and path effects). The residuals of the free-field spectral accelerations recorded at DCPP are computed with respect to the event and distance specific spectral accelerations. The 2003 San Simeon earthquake was recorded at one instrument at DCPP (ESTA27). Following the San Simeon earthquake, additional seismic instrumentation was installed, including an additional free-field instrument (ESTA28). The 2004 Parkfield earthquake was recorded at both free-field instruments (ESTA27 and ESTA28). The velocity profile at the location of instrument no. ESTA28 becomes similar to the power block5 and turbine building profiles at depths of about 100 m (see Figure 2.3.2-4 above). The profile for free-field instrument no. ESTA27 shows a different gradient and does not merge with the power block and turbine building profiles at depth as seen with the profile for ESTA28. Since the profile at instrument no. ESTA28 is more consistent with the power block and turbine building profiles, this site is selected as the control point. 2.3.6 Amplification Functions The residuals for the DCPP free-field recordings were computed (PG&E 2014, Chapter 11) for each of the five event-adjusted NGA-West2 models for a ' The term "power block" herein refers to the combination of the Unit 1 containment structure, the Unit 2 containment structures, and the common auxiliary building. PG&E Letter DCL-15-035 Page 30of60 reference rock with Vs30 = 760 m/s. The average residuals over the five GMPEs are shown on Figure 2.3-1. Overall, the frequency-dependent residuals are consistent between the two recordings over most of the frequency range, but there is a large difference at 0.5 hertz (Hz). In particular, the San Simeon residuals are much larger. The ESTA27 time histories from this earthquake show that the 0.5 Hz ground motion is coming from late-arriving surface waves, indicating different path effects for these two earthquakes. This is not seen in the Parkfield recordings at either ESTA27 or ESTA28. Since the low-frequency residual are not similar for both earthquakes, they are not consistent with a strong site effect. The variability of the low frequency amplification is included in the uncertainty of the site factor. The smoothed model is shown by the heavy black line and represents the OCPP site term relative to the reference free-field instrument no. ESTA28 with Vs30 = 753 m/s. If there was no ground motion data at a given site, then the mean site term would be zero and the epistemic uncertainty in the site term would have a standard deviation of phis2s. which is the standard deviation of the site terms from worldwide data sets. As data is recorded at the site of interest, then the mean site term can be estimated and the epistemic uncertainty reduced from the value of phis2s from global data. The source and path corrected residual at the site given an estimate of the site term. The standard error of the site terms is phis2s divided by JN, where N is the number of recordings. The uncertainty in the estimated of the source and path terms due to the limited number of recordings is added to the standard error of the site term. The standard error of the DCPP site term is listed in Table 2.3.6-1. The upper and lower ranges shown in the figure are based on+/- 1.25 times the standard error and represent the 10th and 90th confidence limits. The epistemic uncertainty in the site term has two components: the uncertainty in the estimated terms for each earthquake and the variability in the single-path within-event residuals (phiO). The uncertainty in the event-path term is given by the standard error of the estimate of the mean residual of the selected subsets of recordings (8 recordings from San Simeon and 16 recordings from Parkfield). The observed ground motion at a site is a sample from a normal distribution with a standard deviation given by the single-path within-event standard deviation (called phiO). The standard deviation of the epistemic uncertainty in the site term is given by sqrt( (SE1 /\2 + phiQA2)/4 + (SE2A2+PhiQA2)/4 ) where SE1 and SE2 are the standard errors of the path terms from San Simeon and Parkfield respectively. The value of phiO is given by Lin et al 2011. The epistemic uncertainty is modeled using a three point distribution based on -1.64. 0, and 1.64 times the standard of the epistemic uncertainty with weights of 0.2, 0.6, and 0.0, respectively. The upper and lower ranges shown in Figure 2.3.6-1 and represent the 5th and 95th confidence limits The central, upper, and lower ranges of DCPP's site-specific site term are listed in Table 2.3.6-1. The median amplification factors and epistemic uncertainty at PG&E Letter DCL-15-035 Page 31 of 60 the control point, using the empirical site response approach, are listed in Appendix A.

• San Simeon residual
• Parkfield residual Average Site-Specific Median Site-Specific -High range 1--Site-Specific -Low range ..... -' _L 0 8 -+-----+------<-*--+--+--+-+-+-+------<----+---+--1--+--<--tt--------,-f--*--+ . ti)' 0 6 . *--* -----i----< ** _ _..; ..., . -------__ .:. __ --!..-;....._ ___ __,_--+----+--+-+--+-+-+* *c: . *
• I I* I r I , ---1--::I 0.4 Pl '... .. z ------>-. + ---*---+--+-i--+f+ ---+---1---+--*-+-l-+-+-I d 0.2 -E -* -*-':--* .;.....
• H+ ..... 0 ., ..... "' _._, , ' * --* -** II :--ia..*-1!-_i. * .2? -0 2 -. -,;* Ii *1 t --I
• I *-* I. -. I (J) -: .. -*i ,i ... '-:'T'* --,.--+ . -. a.. -0. 4 . -' ,__ *-' a.. i.... .. I""": 1--*, --;--*-+----*_+/-* I ! -,-.+-----_; -r-; I ----'*--+-* *-* _,_ -;-{) . .. I ., ___ *-I l .-. I 0 6 . _,., 0 -. ----. -' ! .. -....... -* * * ----r--*j---* ---i-'T--,. -11.--*--.. -*-+---+--1-'Tf-'--i-+--+-f-++ -0.8 . I I I I _.. j ------*--r---.. --!---+--+--11---i-"l-+=l---+--_,._-+-+-+-+-++I . . 0.1 1 10 100 Frequency (Hz) Figure 2.3.6-1: Mean Event-Specific Residuals for DCPP Relative to the ESTA28 Reference Rock Site Condition with V830 = 750 m/s Note: Epistemic uncertainty (10% and 90% confidence levels) is shown by the dashed lines PG&E Letter DCL-15-035 Page 32of60 Table 2.3.6-1. DCPP Site-Specific Site Amplification Terms DCPP Site Term for Control Point (ESTA28) (natural log units) Standard -* Upper J . Lower -Deviation of Frequency DCPP Site (Hz) Term Median _Range_ . 100 -0.20 -0.3 -0.62 0.02 50 -0.20 -0.32 -0.65 0.01 34 -0.20 -0.36 -0.68 -0.04 20 -0.20 -0.52 -0.85 -0.19 13.5 -0.21 -0.52 -0.86 -0.18 10 -0.22 -0.52 -0.88 -0.16 6.7 -0.24 -0.5 -0.89 -0.11 5 -0.22 -0.38 -0.74 -0.02 4 -0.21 -0.24 -0.58 0.1 3.3 -0.21 -0.13 -0.47 0.21 2.5 -0.21 0.19 -0.15 0.53 *---*-* ---* 2 -0.22 0.19 -0.17 0.55 1.3 -0.23 0.19 -0.19 0.57 1 -0.24 0 -0.4 0.4 0.67 -0.26 0 -0.42 0.42 0.5 -0.27 0 -0.44 0.44 0.33 -0.35 0.00 0.58 -0.58 0.2 -0.35 0.00 0.58 -0.58 0.1 -0.35 0.00 0.58 -0.58 2.3.7 Control Point Seismic Hazard Curves The mean hazard for the control point is computed using a method that is consistent with approach 3 of NUREG/CR-6728 (NRC 2001). The site term is added to the median from the ground motion models developed as part of the SSHAC ground motion characterization. Epistemic uncertainty is captured by using a logic tree for the range of the site terms. The mean hazard for the control point for seven frequencies is shown in Figure 2.3.7-1 and listed in Appendix A.

Control Point Enclosure 1 PG&E Letter DCL-15-035 Page 33of60 ---. _::_:-; .. -........ '. : . I '.---+---1--*--1 **- I-! . : I l. ! .. l < I i : *--,II 1* I ' II , ' I'\.. ..... ! 1 X*' 1, I *, 1 x1 o-3 ** , I "-. I ,. ....._' -+--------_.__-+--_.__---+--+--I *-**-.------1----""i,--""*:*'--. :-, __ ;" . i----+---,-----1--f-* -t--', ', 1""-"' ..... " "'"'-_-+-, __ -_-_-_-_ -_ -_J-,_-_-___ 1x10*5-',, . "'-'-I '-i'-1 Spectral Ace (g) I i i : I I J i \ I I Figure 2.3.7-1 Control Point Mean Hazard Curves for PGA and 20, 10, 5, 2.5, 1, and 0_5 Hz Spectral Frequencies 2.4 Control Point Response Spectra 10 The uniform hazard response spectra (UHRS) for 1 x 10-4 and 1 x 10-5 hazard levels at the control point are computed from the mean hazard curves. The UHRS are plotted in Figure 2.4-1 and are listed in Table 2.4-1. The GMRS is computed following the requirements of Regulatory Guide 1.208 (NRC 2007). The GMRS is equal to the 1 x 10-4 UHRS at frequencies greater than or equal to 1 Hz. At lower frequencies, the GMRS is slightly greater than the 1 x 10-4 UHRS. PG&E Letter DCL-15*035 Page 34 of 60 Table 2.4-1 UHRS for 1 E-4 and 1 E-5, and GMRS at Control Point for DCPP -------(5% damping) Frequency Spectral Acceleration (g) (Hz) Control Point 1 E-4 Control Point 1 E-5 GMRS UHRS UHRS -.-...... -100.00 0.812 1.525 0.812 50.00 0.832 1.564 0.832 33.33 0.882 1.659 0.882 20.00 0.983 1.849 0.983 13.33 1.236 2.295 1.236 ....._ .. 10.00 1.405 2.640 1.405 6.67 1.613 3.054 1.613 5.00 1.740 3.305 1.744 4.00 1.785 3.373 1.785 -* --** 3.33 1.714 3.236 1.714 2.50 1.960 3.830 2.010 2.00 1.634 3.186 1.672 1.33 1.200 2.469 1.282 1.00 0.755 1.566 0.812 0.67 0.478 1.017 0.525 0.50 0.318 0.703 0.360 . 0.33 0.188 0.408 0.210 4 3.5 3 .-2.5 Ol -(.) (.) <( 2 ro ..... t5 (]) a. (./) 1.5 1 0.5 0 0.1 *

• Control Point UHAS (AEP=10-4) Control Point UHAS (AEP=10-5) Control Point GMRS , I I I *t . ' ! I I . 1*' 1
• I I ' ' i' .. ' .. I 11, t ' I I l I I I
• I ' ' f1v
• r... I I ' ' I 1, jY I J ' I ' # J ill I , . j I ., I < I ' 1 Frequency (Hz) * ' ' ' Enclosure 1 PG&E Letter DCL-15-035 Page 35of60 I ' I I i I I .. I I I I ! I .. l .. ... .... '"" I ! ! I r i l ' i I I ; I ... 10 100 Figure 2.4-1 UHRS for 1E-4 and 1E-5, and GMRS at Control Point for DCPP PG&E Letter DC L-15-035 Page 36 of 60 3.0 Plant Design, Licensing, and LTSP Evaluation Bases Ground Motions The seismic design, licensing, and LTSP evaluation bases for DCPP are identified in Sections 2.5, 3.1, and 3.7 of the UFSAR, Revision 21 (PG&E 2013) the Hosgri Report (PG&E 1980), the 1988 L TSP Final Report (PG&E 1988), and the 1991 Addendum to the L TSP Final Report (PG&E 1991 ). Since the development of the seismic design/licensing basis for DCPP predates the issuance of Appendix A to 10 CFR 100 (NRC 1973) site-specific criteria and methods were employed in the development of the design/licensing basis ground motions. The seismic design, licensing, and LTSP evaluation of DCPP includes the following earthquakes: 1. Design Earthquake (0.20g PGA) The DE is defined in UFSAR Section 2.5.3.10.1 based on the maximum size earthquakes that can be expected to occur at DCPP during the life of the reactor. Four earthquakes of varying magnitudes and distances were postulated (described as Earthquake A, Earthquake 8, Earthquake C, and Earthquake D in UFSAR Section 2.5.3.9.1 ). The postulated ground motions at DCPP for these four earthquakes were based on empirical data, with certain modifications based on input from the Atomic Energy Commission and their consultants. As described in UFSAR Section 2.5.3.10.1, Earthquakes B and D were found to be governing over Earthquakes A and C. In addition, based on meetings between PG&E, the Atomic Energy Commission, and the Atomic Energy Commission's consultants, the shape of the response spectra associated with Earthquake D was modified and the accelerations associated with Earthquake B were increased by 25 percent. After the incorporation of the modifications, the following two earthquake ground motions were selected to represent the DE for DCPP: (a) Earthquake D-modified, derived by modifying the S80°E component of the 1957 Golden Gate Park. San Francisco earthquake, and then normalizing to a maximum ground acceleration of 0.20 g. The smoothed response spectrum for this earthquake is shown in UFSAR Figure 2.5*21. (b) Earthquake B, derived by normalizing the N69°W component of the 1952 Taft earthquake to a maximum ground acceleration of 0.15 g. The smoothed response spectrum for Earthquake Bis shown in UFSAR Figure 2.5-20. PG&E Letter OCL-15-035 Page 37of60 Seismic design for the DE is based on the envelope of Earthquake B and Earthquake 0-modified. 2. Double Design Earthquake (0.40g PGA) The DOE is defined in UFSAR Section 2.5.3.10.2 as an earthquake having twice the maximum ground acceleration and response spectra as those associated with the DE. 3. 1977 Hosgri Earthquake (0. 75g PGA) The 1977 HE is defined in UFSAR Section 2.5.3.10.3 as the predicted ground motion at DCPP associated with a Richter magnitude 7.5 earthquake on the Hosgri fault at a point nearest to DCPP. There are two ground motion definitions associated with the HE: (a) The Newmark HE, is an earthquake developed by Dr. N. M. Newmark, having an effective maximum horizontal ground acceleration of 0.75 g. The smoothed response spectrum for the Newmark HE is shown in UFSAR Figure 2.5-30. (b) The Blume HE, is an earthquake developed by Dr. J. A. Blume based on empirical data associated with strong-motion time histories recorded on rock close to the epicenters, and normalized to a 0.75 g peak acceleration. The smoothed response spectrum for the Blume HE is shown in UFSAR Figure 2.5-29. The seismic design for the HE is summarized in Supplement No. 5 to the NRC's Safety Evaluation Report (SER) for OCPP (NRC 1976) and is based on the envelope of the loadings associated with the Newmark HE and the Blume HE. The HE is the largest ground motion considered in the seismic design of OCPP. 4. Long Term Seismic Program Earthquake (0.83 g PGA) The L TSPE is associated with license condition 2. C. (7) of the OCPP Unit 1 operating license, that required, in part: "PG&E shall develop and implement a program to reevaluate the seismic design bases used for the OCPP." PG&E's reevaluation effort in response to the license condition was titled the "Long Term Seismic Program." The L TSPE is defined in UFSAR Section 2.5.3.10.4 as the predicted ground motion at OCPP associated with a moment magnitude 7.2 earthquake on the Hosgri fault approximately 4.5 km (3 mi.) from OCPP. PG&E Letter DCL-15-035 Page 38 of 60 The L TSP included both a SPRA and a deterministic SMA. The results of the L TSP are described in the 1988 L TSP Final Report (PG&E 1988) and the 1991 Addend urn to the L TSP Final Report (PG&E 1991 ). The L TSP evaluation concluded that the structures, systems, and components previously qualified for the DE, DOE, and 1977 HE seismic loads remained qualified for the LTSPE. The NRC's review and acceptance of the LTSP evaluations are documented in Supplement No. 34 of the SER for DCPP (NRC 1991). 3.1 Description of Response Spectra Shapes 3.1.1 Double Design Earthquake Response Spectrum The ODE response spectrum, which corresponds to an envelope of the 5 percent damped horizontal Earthquake B (UFSAR Figure 2.5-20) response spectrum and the 5 percent damped Earthquake 0-modified response spectrum (UFSAR Figure2.5-21), multiplied byafactoroftwo, is tabulated in Table3.1.1-1 and illustrated in Figure 3.1.1-1.

I Enclosure 1 PG&E Letter DCL-15-035 Page 39of60 Table 3.1 1-1: DOE Response Spectrum for DCPP (5% DamQing) ----** Period Frequency Spectral Acceleration . __ .Jsec) (Hz) (g) 0.010 100.000 0.400 0.050 20.000 0.400 -* *-0.060 16.667 0.432 0.070 14.286 0.498 0.080 12.500 0.666 0.090 11.111 0.930 0.100 10.000 1.266 0.110 9.091 1.386 .-0.120 8.333 1.434 0.130 7.692 1.464 0.140 7.143 1.476 0.150 6.667 1.473 0.160 6.250 1.467 0.170 5.882 1.443 0.180 5.556 1.413 0.200 5.000 1.338 0.250 4.000 1.182 0.290 3.448 1.047 0.300 3.333 1.005 0.320 3.125 1.009 0.330 3.030 1.005 0.350 2.857 0.993 ****---* 0.380 2.632 0.963 0.500 2.000 0.786 0.580 1.724 0.705 0.660 1.515 0.639 0.740 1.351 0.609 -. 0.880 1.136 0.595 1.000 1.000 0.594 - 1 6 v -..... § L_ Enclosure 1 PG&E Letter DCL-15-035 Page 40of60 -DOE J / LI c 12 .. Oi l u L >--->----* *---/ l 0.8 -04 0.0 I 00 1000 Frequency (Hzl Figure 3.1.1-1: ODE Response Spectrum for DCPP (5% Damping) 3.1.2 1977 Hosgri Earthquake Response Spectrum I 100.00 The 1977 HE response spectrum, which corresponds to an envelope of the 5 percent damped horizontal Newmark HE response spectrum (UFSAR Figure 2.5-30) and the 5 percent damped horizontal Blume HE response spectrum (UFSAR Figure 2.5-29), is tabulated in Table 3.1.2-1 and illustrated in Figure 3.1.2-1. PG&E Letter DCL-15-035 Page 41of60 Table 3.1.2-1: 1977 HE Response Spectrum6 for DCPP (5% Damping) ._ .... ____ , Period Frequency Spectral Acceleration (sec) (Hz) (g) 0.010 100.000 0.750 0.029 34.000 0.750 0.032 31.000 0.784 0.040 25.000 0.912 0.050 20.000 1.067 0.063 16.000 1.248 0.071 14.000 1.371 -... 0.083 12.000 1.528 0.100 10.000 1.737 0.111 9.000 1.870 0.125 8.000 2.032 0.174 5.750 2.032 0.182 5.500 2.044 0.190 5.250 2.061 0.200 5.000 2.080 0.217 4.600 2.106 0.238 4.200 2.128 0.250 4.000 2.125 0.263 3.800 2.118 0.278 3.600 2.111 0.303 3.300 2.075 0.333 3.000 2.032 0.435 2.300 2.032 0.455 ' 2.200 1.975 0.500 2.000 1.795 0.556 1.800 1.616 0.625 1.600 1.436 0.714 1.400 1.257 0.800 1.250 1.124 1.000 1.000 0.898 1.538 0.650 0.586 --* 2.000 0.500 0.411 6 The spectral acceleration values represent the envelope of the Newmark HE (UFSAR Figure 2.5-30) and the Blume HE (UFSAR Figure 2.5-29). Note that the HE response spectra have been extrapolated to a minimum frequency of 0.50 Hz for this application. 2.5 2.0 o.s 0.0 0.10 ----v ..... ' -f J I I/"". I *' , 1.00 Frequency (Hz) ....... ' \ Enclosure 1 PG&E Letter DCL-15-035 Page 42 of 60 -t<E(IJFSAA) 1--*HE ! \. 10.00 100.00 Figure 3.1.2-1: 1977 HE Response Spectrum for DCPP (5% Damping) 3.1.3 Long Term Seismic Program Earthquake Spectrum The 5 percent damped horizontal 84th percentile of non-exceedance 1991 L TSPE response spectrum (UFSAR Figure 2.5-33), is tabulated in Table 3.1.3-1 and illustrated in Figure 3.1.3-1. PG&E Letter DCL-15-035 Page 43of60 Table 3.1.3-1: 1991 L TSPE 84th Percentile Response Spectrum for DCPP (5% Damping) Period Frequency Spectral Acceleration (sec) (Hz) (g) 0.010 100.000 0.830 0.025 40.000 0.830 ---0.030 33.000 0.830 0.040 25.000 0.964 0.050 20.000 1.110 0.070 14.286 1.344 0.085 11.765 1.508 0.100 10.000 1.654 0.120 8.333 1.819 0.140 7.143 1.918 0.150 6.667 1.947 0.170 5.882 1.976 0.200 5.000 2.006 -* --* 0.250 4.000 2.015 0.300 3.333 1.962 0.400 2.500 1.763 0.500 2.000 1.554 0.750 1.333 1.109 1.000 1.000 0.831 1.500 0.667 0.524 2.000 0.500 0.356 2.5 2.0 !.:! 0.5 0.0 D.10 ,; :/;> I ) '.l 1.00 :I ' ... *' l ' / ' *' .> ...... fJeQuency tHz) v ....... i\ \ Enclosure 1 PG&E Letter DCL-15-035 Page 44of60 I -\i19! LTSP I \ .\ . "* ', '** >-oH 10,00 Figure 3.1.3-1: 1991 L TSPE 84th Percentile Response Spectrum for DCPP (5% Damping) 3.2 Control Point Elevation 7 The control point elevation for DCPP's ODE is defined based on the criteria provided in Section 2.4.2 of the SPID (EPRI 2013a). As shown on UFSAR Figures 2.5-15, 2.5-16, and 2.5-17, all original surface materials (soil and rock) were removed from the locations of the major structures7 and their foundations were excavated into the bedrock. Therefore, the major structures are rock-founded. The free-field ground motions, associated with the DOE (described in Section 3.1.1) and the 1977 HE (described in Section 3.1.2), are used as input to all structures at DCPP. The UFSAR does not explicitly define a control point for the ground motions, but it can be derived from the seismic analyses of structures described in UFSAR Section 3.7. Based on a review of the seismic analyses of the major structures, as described in UFSAR Section 3.7.2.1.7. the control point for the seismic analyses is the finished grade level, which corresponds to Major structures at OCPP include the containment structures, the auxiliary building, and the turbine building. PG&E Letter DCL-15-035 Page 45 of 60 26 m (85 ft) mean sea level at the location of the major structures (see UFSAR Figure 2.5-18). This is consistent with the control point elevation associated with the site response evaluation, as described in Section 2.3. Since the site-amplification studies associated with the GMRS (Section 2.4) are developed based on the free-field recordings of historical earthquakes affecting DCPP, the control point is specifically at the location of free-field seismic instrument no. ESTA28 (located in the yard area at elevation 26 m (85 ft). approximately 96 m (316 ft) north of the centerline of the Un it 1 containment structure and 2.4 m (8 ft) east of a north-south line passing through the centerlines of the Unit 1 and Unit 2 containment structures -see Figure 2.3.2-4). See Section 2.3.5 for additional information on the selection of the control point. PG&E Letter DCL-15-035 Page 46of60 4.0 Screening Evaluation In accordance with Section 3 of the SPID, a screening evaluation was performed, as described in the following subsections. As stated in the NRC's letter to PG&E dated October 12, 2012 (NRC 2012c), "for the purposes of the response to the March 12, 2012 request for information, the NRC staff expects PG&E to use the DOE for comparison with the reevaluated seismic hazard GMRS." Therefore, the following screening evaluations are based on the DOE. 4.1 Risk Evaluation Screening (1 to 10 Hz) § c .2 -e .!! .. u "iD .. u .. Q, Cl.I The GMRS exceeds the DOE in the 1 to 10 Hz frequency range, as shown in Figure 4. Therefore DC PP screens-in for a risk evaluation. 30 25 20 1.$ 1.0 o.s 0.0 0.10 y / I I '* I ' : I I ' I-' ' _J *x '1 */ / .,, 1' **"' * ! i 1 I I I l 1.00 Frequency {Hz) 1-Gr.tRS I -oce 'I'-.-. .,. "' ' \ ............. """-........ 10.00 Figure 4.1-1: Comparison of GMRS and DOE Spectrum for DCPP (5% Damping) 100.00 4.2 High Frequency Screening(> 10 Hz) The GMRS exceeds the DOE for frequencies greater than 10 Hz, as shown in Figure 4.1-1. This exceedance will be addressed in the required risk evaluation. 4.3 Spent Fuel Pool Evaluation Screening (1 to 10 Hz) Enclosure 1 PG&E Letter DCL-15-035 Page 47 of 60 The GMRS exceeds the ODE in the 1 to 10 Hz frequency range, as shown in Figure 4. 1-1 . Therefore DC PP screens-in for a SFP evaluation. Note that at DCPP the SFPs are located in the fuel handling area of the auxiliary building. 5.0 Interim Evaluation Enclosure 1 PG&E Letter Page 48 of 60 Consistent with the NRG letter dated February 20, 2014, (NRG 2014) the seismic hazard reevaluations presented herein are distinct from the current design and licensing bases of DCPP. Consequently, the results of these analyses performed using present-day regulatory guidance, methodologies, and information would not generally be expected to call into question the operability or functionality of structures, systems, and components, and are not reportable pursuant to 10 CFR 50.72 or 10 CFR 50.73. The NRC's March 12, 2012 10 CFR 50.54(f) letter (NRC 2012) and February 20, 2014 supplemental letter (NRC 2014) request that Licensees submit an interim evaluation or actions taken or planned to address the reevaluated hazard where it exceeds the current design basis, if necessary prior to completion of the risk evaluation. PG&E's interim evaluation is based on comparisons of the beyond design basis GMRS to the design/licensing basis 1977 HE and the 1988 L TSP evaluations: (a) 1977 HE Evaluation All Design Class I structures. systems, and components at DCPP, including the SFPs8, have been designed/evaluated for the design/licensing basis 1977 HE spectrum and found to meet the HE acceptance criteria (PG&E 1980 and NRC 1978b). A comparison of the GMRS with the design/licensing basis 1977 HE spectrum is shown in Figure 5.0-1. This comparison indicates that, with the exception of an exceedance of approximately 0.09 g (7 percent) at 1.33 Hz, the GMRS is bounded by the design/licensing basis 1977 HE spectrum at all frequencies in the 1 to 10 Hz frequency range (frequency range associated with the risk evaluation screening). The exceedance is insignificant because no structure, system, or component required for safe shutdown is susceptible to the 1.33 Hz frequency (Tables 6-24 and 6-25 of PG&E 1988). The GMRS also exceeds the design/licensing basis 1977 HE spectrum for frequencies> 24 Hz. As stated in Section 3.4 of the SPID (EPRI 2013a): "high-frequency vibratory motions above about 10 Hz are not damaging to the large majority of (nuclear power plant] structures, components, and equipment. An exception to this is the functional performance of vibration sensitive components, such as relays and 6 As indicated in Section 4.3, the SFPs are located in the fuel handling area of the auxiliary building. which is a Design Class I structure. § c 0 .. .. Cl .. u '"' ii .. ... u " a. I/) 9 3.0 2.5 2.0 1.5 10 0.0 0.10 Enclosure 1 PG&E Letter Page 49 of 60 other electrical and instrumentation devices whose output signals could be affected by high-frequency excitations." Therefore, in accordance with Section 3.4 of the SPID (EPRI 2013a), the results of the design/licensing basis 1977 HE evaluation demonstrate that all Design Class I structures, systems, and components are capable of resisting the ground motions associated with the GMRS with exception of the high-frequency sensitive equipment. The impact of the high-frequency exceedance is addressed as part of the L TSP evaluation, discussed below. -GURS -HE(UFS.-'IR) v ........ ---HE ---If' ' -.. ' ) ...... ..... \ I ,( i-.-. lit.. *' 1.00 10.00 100.00 Frequency (Hz) Figure 5.0-1: Comparison of GMRS and 1977 HE Design Spectrum for DCPP (5% Damping) (b) 1988 LTSP Evaluation All structures9, systems, and components required for safe shutdown 10 have been evaluated for the 1988 L TSP spectrum and found to have The auxiliary building. which contains the SFPs, is included in the scope of the LTSP evaluation. 10 The safe shutdown-related structures, systems, and components addressed in the 1988 L TSP are listed in Tables 7 -1 and 7-2 of the 1988 L TSP Final Report {PG&E 1988) 3.0 2.5 2.0 0.5 Enclosure 1 PG&E Letter DCL-15-035 Page 50 of 60 significant seismic margins (see Appendix B for discussion of the LTSP seismic margins). A comparison of the GMRS with the L TSP seismic margin spectrum is shown in Figure 5.0-2. This comparison indicates that the GMRS is bounded by the LTSP seismic margin spectrum at all frequencies, including 1.33 Hz and those > 24 Hz -frequencies where the GMRS exceeds the design/licensing basis 1977 HE spectrum. Therefore, comparing the results of the revised GMRS against the 1988 L TSP evaluation demonstrate that all structures, systems, and components required for safe shutdown, including vibration sensitive components, have a significant seismic design margin beyond the GMRS. -er.IRS -. : ... -LTSP Seismic r.1 argln Spectrum / \ I \ .' /\ \ . I I v ......... ' ,/ J \ ...... , \ // "!'. I\ *\ .. '* ----/ I r-....... .....__ I II / I / *I /" 00 0.10 100 10.0*) 100.00 Frequency (Hz) Figure 5.0-2: Comparison of GMRS and LTSP Seismic Margin Spectrum for DCPP (5% Damping} Based on the above comparisons to the design/licensing basis 1977 HE evaluation and the 1988 L TSP evaluation, there is reasonable assurance that DCPP remains safe to operate without undue risk to the public while an updated risk evaluation is being performed. PG&E Letter DCL-15-035 Page 51 of 60 The consideration of potential loss of the water inventory from the SFPs, as described in Section 7 of the SPID (EPRI 2013a), has been addressed as part of the NTTF Recommendation 2.3: Seismic Walkdowns, as discussed in Section 5.2. The results of these walkdowns demonstrated that the potential for loss of the water inventory from the SFPs (e.g., rapid draindown) has been adequately addressed in the design and construction of DCPP's SFPs. Further evaluatrons of the potential loss of the water inventory from the SFPs will be performed once an NRC-endorsed guidance has been developed. 5. 1 Expedited Seismic Evaluation Process The ESEP, as proposed in the NEl's letter to the NRC, dated April 9, 2013 (NEI 2013) and confirmed in NRC letter dated May 7, 2013 (NRC 2013), is described in EPRI Technical Report No. 3002000704 (EPRI 2013b). The ESEP was intended as an interim measure to provide additional assurance of safety in cases where the GMRS significantly exceeds the plant design/licensing basis while additional risk evaluations (i.e., SMA, or SPRA) were being performed. However, as discussed in Section 5.0, the DCPP GMRS is bounded by other previous seismic evaluations, including the design/licensing basis 1977 HE evaluations and the 1988 LTSP evaluation. Therefore. there are no additional benefits in performing this activity in parallel with the more robust risk evaluation associated with updating/upgrading the SPRA. PG&E will devote the critical skilled resources to expediting the update/upgrade of the SPRA in order to gain additional risk insights in a timely manner. 5.2 Walkdowns to Address NRC Fukushima NTTF Recommendation 2.3: Seismic In response to the NRC's March 12, 2012 50.54(f) letter Fukushima NTTF Recommendation 2.3: Seismic (NRC 2012), PG&E performed walkdowns of the configuration of specific equipment and components in accordance with EPRI Technical Report No. 1025286 (EPRI 2012), as endorsed by the NRC in their letter dated May 31, 2012 (NRC 2012a). The goals of these walkdowns were to (a) verify that the current plant configuration was in accordance with the licensing basis; (b) verify that the current maintenance plans were adequate to maintain the plant configuration in accordance with the licensing basis; and (c) identify any seismic vulnerabilities. The potential for loss of water inventory from the SFPs (e.g., rapid draindown) was included in the scope of these walkdowns. The walkdowns of DCPP, Units 1 and 2, as documented in several PG&E letters to the NRC (PG&E 2012, PG&E 2012a, PG&E 2013b, and PG&E 2014a) identified a number of potentially adverse seismic conditions, which were entered into the DCPP corrective action program. The engineering evaluations of the potentially adverse seismic conditions determined that they did not adversely affect the performance of any required safety functions. including the ability to maintain the water inventory of the SFPs during a seismic event. Therefore, PG&E Letter DCL-15-035 Page 52 of 60 these walkdowns confirmed that the configuration of DCPP is within its seismic design/licensing basis and provided additional assurance of seismic safety. The NRC has reviewed the DCPP NTTF Recommendation 2.3: Seismic walkdown submittal reports and the results of their staff assessment (NRC 2014a) concluded that sufficient information was provided by PG&E to be responsive to the requirements of their March 12, 2012 10 CFR 50.54(f) letter (NRC 2012). 6.0 Conclusions Enclosure 1 PG&E Letter DCL-15-035 Page 53of60 PG&E completed a seismic hazard and screening evaluation for DCPP in accordance with the NRC's Fukushima 10 CFR 50.54(f) request for information letter (NRC 2012), and consistent with the NRC endorsed SPID guidelines (EPRI 2013a). A GMRS was developed solely for the purpose of screening for additional evaluations in accordance with the SPID. The DCPP GMRS exceeds the design and licensing basis DOE spectrum in both the 1 to 10 Hz range and above 10 Hz. Therefore, an updated risk evaluation and a SFP evaluation for potential loss of water inventory, in accordance with the SPID (EPRI 2013a) will be performed. PG&E also compared the GMRS with the L TSP seismic margin spectrum, described in Section 5.0. The comparison shows that DCPP's structures, systems and components required for safe shutdown and the SFPs have significant design margins beyond the GMRS. In addition, the results of the Fukushima NTTF Recommendation 2.3: Seismic walkdowns. described in Section 5.2, show that the potential for loss of water inventory from the SFPs has been adequately addressed. Therefore, DCPP remains safe to operate without undue risk to the public while an updated risk evaluation and detailed SFP evaluation for potential loss of water inventory are being performed. PG&E will perform an update to the SPRA in accordance with the EPRI guidance (EPRI 2013a) in support of the resolution of Fukushima NTTF Recommendation 2.1: Seismic. PG&E believes that since there are no additional insights to be gained from an implementation of an ESEP, PG&E will devote its resources to performing a more robust SPRA. PG&E will perform additional evaluations of the SFPs to address potential loss of water inventory in accordance with the EPRI guidance (EPRI 2013a) and any additional NRC endorsed guidance that may be issued. The completion dates for the SPRA and SFP evaluations will be based on the schedule as defined in NEl's letter to the NRC, dated April 9, 2013 (NEI 2013) and confirmed in NRC's letter, dated May 7. 2013 (NRC 2013). 7.0 References 7.1 Electric Power Research Institute Enclosure 1 PG&E Letter DCL-15-035 Page 54of60 (a) EPRI 2012, "Seismic Walkdown Guidance for the Resolution of Fukushima Near-Term Task Force Recommendation 2.3: Seismic," Technical Report No. 1025286, dated June 2012 (b) EPRI 2013a, "Seismic Evaluation Guidance -Screening, Prioritization and Implementation Details (SPID) for the Resolution of Fukushima Near-Term Task Force Recommendation 2.1: Seismic," Technical Report No. 1025287, dated February 2013 (c) EPRI 2013b, "Seismic Evaluation Guidance: Augmented Approach for the Resolution of Fukushima Near-Term Task Force Recommendation 2.1: Seismic," Technical Report No. 3002000704, dated April 2013 (d) EPRI 2013c, EPRI (2004, 2006) Ground-Motion Model (GMM) Review Project," Technical Report No. 3002000717, 2 Volumes, dated June 2013 7.2 Pacific Gas and Electric Company (a) PG&E 1980, PG&E Report, "Seismic Evaluation for Postulated 7.5M Hosgri Earthquake -Units 1 and 2, Diablo Canyon Site," transmitted to the NRC as Amendment Nos. 50, 53, 54, 56, 59, 60, 62, 64, 66, 68, 70, 72. 75, 76, 77, 79, 82, and 83 to the Operating License Application for Diablo Canyon Power Plants Units 1 and 2," dated June 3, 1977 through June 6, 1980 (b) PG&E 1988, PG&E Report, "Final Report of the Diablo Canyon Long Term Seismic Program for the Diablo Canyon Power Plant," Enclosure to PG&E Letter DCL-88-192, "Long Term Seismic Program Completion," dated July 31, 1988 (c) PG&E 1990, PG&E Report, "Additional Deterministic Evaluations Performed to Assess Seismic Margins of the Diablo Canyon Power Plant. Units 1 and 2," Enclosure to PG&E Letter DCL-90-226, "Long Term Seismic Program Additional Deterministic Evaluations," dated September 18, 1990 (d) PG&E 1991, PG&E Report, "Addendum to the 1988 Final Report of the Diablo Canyon Long Term Seismic Program," Enclosure to PG&E Letter DCL-91-027, "Addendum to Long Term Seismic Program Final Report, dated February 13, 1991 PG&E Letter DCL-15-035 Page 55 of 60 (e) PG&E 2011, PG&E Report, "Report on the Analysis of the Shoreline Fault Zone, Central Coastal California, report to the U.S. Nuclear Regulatory Commission," Enclosure to PG&E Letter DCL-11-005, "Report on the Analysis of the Shoreline Fault Zone, Central Coastal California," dated January 7, 2011 (f) PG&E 2012, PG&E Letter DCL-12-118, "Response to Request for Information Pursuant to 10 CFR 50.54(f) Regarding Recommendation 2.3 Seismic Unit 1," dated November 27, 2012 (g) PG&E 2012a, PG&E Letter DCL-12-119, "Response to Request for Information Pursuant to 10 CFR 50.54(f) Regarding Recommendation 2.3 Seismic Unit 2," dated November 27, 2012 (h) PG&E 2013, "Diablo Canyon Power Plant Units 1 & 2 Final Safety Analysis Report Update," Revision 21, dated September 2013 (i) PG&E 2013b, PG&E Letter DCL-13-054. "Response Amendment to Request for Information Pursuant to 10 CFR 50.54(f) Regarding Recommendation 2.3 Seismic," DCPP Unit 2, dated May 22, 2013 (j) PG&E 2013d, PG&E Letter DCL-13-044, "Response to NRC Request for Information Pursuant to 10 CFR 50.54(f) Regarding the Seismic Aspects of Recommendation 2.1 of the Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accident," dated April 29, 2013 (k) PG&E, 2014, PG&E Report, "Central Coastal California Seismic Imaging Project Report to the California Public Utilities Commission." Enclosure to PG&E Letter DCL-14-081, "Central Coastal California Seismic Imaging Project, Shoreline Fault Commitment," dated September 10, 2014 (I) PG&E 2014a, PG&E Letter DCL-14-041, "Response Update to Request for Information Pursuant to 10 CFR 50.54(f) Regarding Recommendation 2.3 Seismic Unit 1 .dated May 8, 2014 (m) PG&E 2015, "Seismic Source Characterization for Probabilistic Seismic Hazard Analysis for the Diablo Canyon Power Plant, San Luis Obispo County, California," Report on the Results of the SSHAC Level 3 Study in Partial Compliance with NRC Letter 50.54(f). dated March 2015. 7.3 United States Nuclear Regulatory Commission (a) NRC 1973. "Seismic and Geologic Siting Criteria for Nuclear Power Plants," Appendix A to Part 100, "Reactor Site Criteria," of Title 10, "Energy," of the Code of Federal Regulations, dated December 13, 1973 PG&E Letter DCL-15-035 Page 56of60 (b) NRC 1976, "Supplement No. 5 to the Safety Evaluation Report by the Office of Nuclear Reactor Regulation. U.D. Nuclear Regulatory Commission, in the Matter of Pacific Gas and Electric Company, Diablo Canyon Nuclear Power Station, Units 1 and 2, Docket Nos. 50-275 and 50-323," NUREG-0675, Supplement No. 5, dated September 10. 1976 (c) NRC 1978a. "Seismic Design Classification," Regulatory Guide 1.29, Revision 3, dated September 1978 (d) NRC 1978b, "Supplement No. 7 to the Safety Evaluation Report by the Office of Nuclear Reactor Regulation, U.D. Nuclear Regulatory Commission, in the Matter of Pacific Gas and Electric Company, Diablo Canyon Nuclear Power Station, Units 1 and 2, Docket Nos. 50-275 and 50-323," NUREG-0675, Supplement No. 7, dated May 26, 1978 (e) NRC 1991. "Safety Evaluation Report related to the operation of Diablo Canyon Nuclear Power Plant, Units 1 and 2, Docket Nos. 50-275 and 50-323, Pacific Gas and Electric Company," NUREG-0675, Supplement No. 34, dated June 1991 (f) NRC 1997. "Recommendations for Probabilistic Seismic Hazard Analysis: Guidance on Uncertainty and Use of Experts -Main Report," NUREG/CR-6372, Volume 1, dated April 1997 (g) NRC 2001, "Technical Basis for Revision of Regulatory Guidance on Design Ground Motions: Hazard* and Consistent Ground Motion Spectra Guidelines," NUREG/CR-6728, dated November 6, 2001 (h) NRC 2007, "A Performance-Based Approach to Define the Site-Specific Earthquake Ground Motion," Regulatory Guide 1.208, dated March 2007 (i) NRC 2012, letter from Eric J. Leeds (NRC) to All Power Reactor Licensees and Holders of Construction Permits in Active or Deferred Status, "Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Recommendations 2.1, 2.3, and 9.3 of the Near-Term Task Force Review of Insights from the Fukushima Dai-lchi Accident," dated March 12, 2012 (ADAMS Accession No. ML 12056A046) G) NRC 2012a, letter from David L. Skeen (NRC) to Adrian P. Heymer (NEI), "Endorsement of Electric Power Research Institute (EPRI) Draft Report 1025286, 'Seismic Walkdown Guidance', dated May 31, 2012 PG&E Letter DCL-15-035 Page 57of60 (k) NRC 2012b, "Practical Implementation Guidelines for SSHAC Level 3 and 4 Hazard Studies," NUREG-2117, Revision 1, dated April 2012 (I) NRC 2012c, letter from Joseph M. Sebrosky (NRC) to Edward P. Halpin (PG&E), "Diablo Canyon Power Plant, Unit Nos. 1 and 2 -NRC Review of Shoreline Fault (TAC Nos. ME5306 and ME5307)," dated October 12, 2012 (m) NRC 2013, letter from Eric J. Leeds (NRC) to Joseph E. Pollack (NEI}, "Electric Power Research Institutes Final Draft Report XXXXX, 'Seismic Evaluation Guidance: Augmented Approach for the Resolution of Fukushima Near-Term Task Force Recommendation 2.1: Seismic,' As an Acceptable Alternative to the March 12, 2012, Information Request for Seismic Reevaluations," dated May 7, 2013 (ADAMS Accession No. ML 13106A331)11 (n) NRC 2014, letter from Eric J. Leeds (NRC) to All Power Reactor Licensees and Holders of Construction Permits in Active or Deferred Status on the Enclosed List, "Supplemental Information Related to Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Seismic Hazards Reevaluations for Recommendation 2. 1 of the Near-Term Task Force Review of Insights from the Fukushima Dai-lchi Accident," dated February 20, 2014 (ADAMS Accession No. ML 14030A046) (o) NRC 2014a. letter from James Kim (NRC) to Edward 0. Halpin (PG&E). "Diablo Canyon Power Plant, Units 1 and 2 -Staff Assessment of the Seismic Walkdown Reports Supporting Implementation of Near-Term Task Force Recommendation 2.3 Related to the Fukushima Dai-lchi Nuclear Power Plant Accident (TAC Nos. MF0117 and MF0118)," dated March 14, 2014. (p} NRC 2014c, memorandum from Nicholas J. DiFrancesco (Senior Project Manager, Japan Lessons-Learned Division) to Sheena A. Whaley (Chief. Japan Lessons-Learned Division), "Summary of October 27, 2014, Category 2 Public Meeting with the Nuclear Energy Institute to Discuss Seismic Hazard Reevaluations Associated with Implementation of Japan Lessons-Learned Near-Term Task Force Recommendation 2.1, Seismic," dated December 15, 2014 (ADAMS Accession No. ML 143078726) 11 EPRI Draft Report XXXXX referenced in the title of this letter corresponds to EPRI Technical Report No. 3002000704 (EPRI 2013b}. PG&E Letter DCL-15-035 Page 58of60 (q) NRC 2014d, memorandum from Nicholas J. DiFrancesco (Senior Project Manager, Japan Lessons-Learned Division) to Sheena A. Whaley (Chief, Japan Lessons-Learned Division), "Summary of December 4, 2014, Category 2 Public Meeting with the Nuclear Energy Institute to Discuss Seismic Hazard Reevaluations for the Western United States Sites Associated with Implementation of Japan Lessons-Learned Near-Term Task Force Recommendation 2.1, Seismic, dated December 15, 2014 (ADAMS Accession No. ML 14342A901) 7.4 Nuclear Energy Institute (a) NEI 2013, letter from Anthony R. Pietrangelo (NEI) to David L. Skeen (NRC), "Proposed Path Forward for NTTF Recommendation 2.1 Seismic Reevaluations, dated April 9. 2013 (ADAMS Accession No. ML 13101A379) 7.5 Other (a) Al-Atik, L., Abrahamson, N., Bommer, J., Scherbaum, F., Cotton, F .* Kuehn, N. 2010, "The Variability of Ground-Motion Prediction Models and Its Components, Seismological Research Letters, Volume 81, Issue 5, pp. 794-801. (b) DeMets, C., Marquez-Azua, B., and Cabral-Cano, E. 2014, "A new GPS velocity field tor the Pacific Plate -Part 1: constraints on plate motion, intraplate deformation, and the viscosity of Pacific basin asthenosphere" Geophysical Journal International. Volume 199: 1878-1899. (c) GeoPentech 2015, "Southwestern United States Ground Motion Characterization SSHAC Level 3," Technical Report, Revision 1, dated February 2015 (d) Hanson, K.L., and Lettis, W.R. 1994, "Estimated Pleistocene slip rate for the San Simeon fault zone, south-central coastal California: in Alterman, 1.B., McMullen, RB., Cluff, LS., and Slemmons, D.B. (editors), Seismotectonics of the Central California Coast Range, Geological Society of America Special Paper 292, pp. 133-150 (e) Hardebeck, J.L. 2010, "Seismotectonics and fault structure of the California central coast," Bulletin of the Seismological Society of America, Volume 100, Issue 3: pp 1031-1050. (f) Hardebeck. J.L. 2013. "Geometry and earthquake potential of the Shoreline Fault, Central California," Bulletin of the Seismological Society of America Volume 103, Issue 1: pp 447-462 PG&E Letter DCL-15-035 Page 59of60 (g} Johnson, S.Y., Hartwell, S.R., and Dartnell, P. 2014, "Offset of Latest Pleistocene shoreface reveal slip rate on the Hosgri strike-slip fault, offshore central California," Bulletin of the Seismological Society of America, Volume 104, Issue 4, doi:10.1785/012013057. (h) Kamai, R., Abrahamson, N., Silva, W. 2014, "Nonlinear Horizontal Site Amplification for Constraining the NGA-West2 GMPEs," Earthquake Spectra, Volume 30, Issue 3. pp. 1223-1240 (i) Ktenidou, 0. and N. Abrahamson. 2015 "A methodology for the selection of data and the estimation of kappa (K) for hard rock sites in the NGA databases," Pacific Earthquake Engineering Research Center, PEER Report 2015/03. 0) Lin, P., N. Abrahamson, M. Walling, C.-T. Lee, B. Chiou, and C. C., Heng, 2011, "Repeatable path effects on the standard deviation for empirical ground-motion models," Bulletin of the Seismological Society of America, Volume 101, pp. 2281-2295. (k) Lettis, W.R., and Hall, N.T. 1994, "Los Osos fault zone, San Luis Obispo County, California: in Alterman, 1.8., McMullen, R.B., Cluff. LS .. and Slemmons, D.8. (editors), Seismotectonics of the Central California Coast Ranges," Geological Society of America Special Paper 292, pp. 73-102, and Plate 5. (I) Lettis, W.R., Kelson, K.I., Wesling, J.R., Angell, M., Hanson, K.L.. and Hall, N. T. 1994, "Quaternary deformation of the San Luis Range, San Luis Obispo County, California," in Alterman, 1.8., McMullen, R.B., Cluff, LS., and Slemmons, D.B. (editors), Seismotectonics of the Central California Coast Ranges. Geological Society of America Special Paper 292, pp. 111-132. (m) Lettis, W.R., Hanson, K.L, Unruh, J.R., Mclaren, M.K., Savage, W.U. 2004, "Quaternary Tectonic Setting of South-Central Coastal California," U.S. Geological Survey Bulletin, 1995 (AA): pp. 1-21. (n) Mclaren, M.K., and Savage, W.U. 2001, "Seismicity of South-Central Coastal California: October 1987 through January 1997, Bulletin of the Seismological Society of America, Volume 91, Issue 4: 1629-1658. PG&E Letter DCL-15-035 Page 60 of 60 (o) Willingham, C.R., Rietman, J.D., Heck, R.G., and Lettis, W.R. 2013, "Characterization of the Hosgri Fault Zone and adjacent structures in the offshore Santa Maria Basin, south-central California: in Keller, M.A. (editor), Evolution of Sedimentary Basins/Onshore Oil and Gas Investigations-Santa Maria Province," U.S. Geological Survey Bulletin 1995-CC, pp. 105 (revised version of 1995 report). PG&E Letter DCL-15-035 Appendix A Page 1of13 Appendix A -Additional Seismic Hazard Curve Data A 1.0 Hazard for the Reference Rock Site Enclosure 1 PG&E Letter DCL-15-035 Appendix A Page 2 of 13 The mean hazard by source for the reference rock site are listed in Table A 1.0-1 for 10 Hz spectral acceleration and in Table A 1.0-2 for 1 Hz spectral acceleration. The deaggregation of the mean hazard at the 1 x 10-4 hazard level for 10 and 1 Hz are shown in Figures A 1.0-1 and A 1.0-2, respectively. The degregation shows that the hazard at OCPP at the 1 x 10-4 hazard level is controlled by nearby earthquakes(< 10 km) with moment magnitudes (M) in the M6 to MS range. A2.0 Hazard for the Control Point The mean hazard for the control point and the fractiles of the hazard, that capture the epistemic uncertainty, are listed in Tables A2.0-1 through A2.0-7 for the peak acceleration and six spectral frequencies: 20, 10, 5, 2.5, 1, and 0.5 Hz. A3.0 Site Amplification for the Control Point The median amplification (from the reference rock site to the control point) is listed in Table A3.0-1. The epistemic uncertainty in the median amplification is quantified by the logarithmic standard deviation listed in Table A3.0-1. The non-linear effects are captured addressed by the empirical ground motion models used for the reference rock site (Vs30= 760 mis and kappa= 0.041 seconds). The aleatory variability of the site response is captured by the standard deviation of the empirical ground motions. The single-station sigma approach removes the differences in the site-specific site amplification from the traditional ergodic standard deviation, but the single-station sigma approach does not remove the aleatory variability in the site amplification from the empirically-based standard deviations. PG&E Letter DCL-15-035 Appendix A Page 3of13 Table A1 .0-1. Mean Hazard by Source for the Reference Rock Site for 10 Hz -Spectral Acceleration. ViGiffi.t y-San 6'3tlffie-10 Hz Los Luis Local San Other ;;oReOthE r PSA Total Hosgri Shoreline Osos Bay source Andreas connected regional (a) Hazard fault fault fault fault zone fault faults faults 4.4E-8.3E-4.8E-0.01 3.9E-01 2.1 E-02 3.9E-04 04 7.1E-04 04 9.0E-02 2.1E-03 4.1E-8.0E-9.3E-0.05 7.SE-02 1.0E-02 2.7E-04 04 5.8E-04 1.9E-02 1.3E-03 3.4E-7.3E-036,e.E-3.6E-0.1 3.1 E-02 6.5E-03 2.2E-04 04 5.2E-04 G3 5.9E-03 8.5E-04 ... ___ -2 lE-6.2E-031.,..JE-1.1E-0.2 1.2E-02 3.?E-03 1.7E-04 04 4.SE-04 93 1.4E-03 4.6E-04 Q3.1-,2£..Q3 9.4E-4.4E-04.:\-:-&e-2.2E-0.4 4.6E-03 1.SE-03 1.1E-04 04 3.4E-04 04 1.SE-04 1.BE-04 2.8E-2.1E-04.f.,.2E-2.1E-0.8 1.5E-03 6.SE-04 5.9E-05 04 1.9E-04 05 1.0E-05 3.9E-05 0544E--05 6.0E-5.6E-058AE-1.5E-1.5 3.?E-04 1.6E-04 1.SE-05 05 6.SE-05 o+

• 5.5E-07 5.2E-06 06&.+E-Op .. 2.5E-2.5E-052-:2-E-4.1 E-2.0 1.6E-04 6.?E-05 8.2E-06 05 3.1E-05 o+ 1.3E-07 1.7E-06 0 7.(;..-0 *-6.2E-6.6E-062.,9£-5.6E-3.0 4.1E-05 1.6E-05 2.2E-06 06 9.0E-06 08 1.3E-08 3.3E-07 oai,.:le-Ol< 8.5E-' 9.6E-07+.8E-3.5E-5.0 5.?E-06 2.1 E-06 3.1E-07 07 1.4E-06 09 5.9E-10 3.2E-08 093,-lE-O.B --* 4 OE-4.8E-082 . .SE-4.BE-10.0 2.?E-07 8.9E-08 1.5E-08 08 7.4E-08 14 3.1 E-12 9.2E-10 11 9A E -4 P *------Table A1 .0-2: Mean Hazard by Source for the Reference Rock Site for 1 Hz Spectral Acceleration. ViGffii Y-&eUH e-Regiooal WAel 1 Hz Los Local San Other her PSA Total Hosgri Shoreline Osos San Luis source Andreas connected regio1 a (g) Hazard fault fault fault Bay fault zone fault faults I faul s 0.01 1.SE-01 7.BE-03 ! 2.?E-04 7.6E-04 5.6E-04 3.7E-4.BE-02 1.1E-03 3.4E 0.05 1.6E-02 2.SE-03 1.4E-04 5.3E-04 3.BE-04 0.1 5.0E-03 1.3E-03 9.6E-05 3.9E-04 2.9E-04 --*-*-0.2 1.6E-03 6.8E-04 5.7E-05 1.9E-04 1.6E-04 -----*----* 0.4 4.SE-04 2.6E-04 2.1E-05 4.6E-05 5.2E-05 0,8 8.0E-05 5.4E-05 3.9E-06 5.3E-06 9.2E-06 1.5 1.0E-05 7.4E-06 5.2E-07 4.SE-07 1.2E-06 2.0 3.6E-06 2.6E-06 1.BE-07 1.4E-07 4.0E-07 3.0 6.9E-07 5.2E-07 3.6E-08 2.2E-08 7.7E-08 5.0 7.2E-08 5.4E-08 3.9E-09 1.7E-09 7.9E-09 1.2E-5.2E-Q4 1.8E-G5 4 SE-06 Enclosure 1 PG&E Letter DCL-15-035 Appendix A Page 4 of 13 02&.-B-OJ 2.4E 031-,-t-4.2E-03 4.6E-04 Q4 5.0E 04W 9.BE-04 2.1E-04 94 5.9E 053.:-9 1.3E-04 5.4E-05 Q5 4.2E 06d.:+ 9.7E-06 7.1E-06 00 *-*-* 6.SE-1.8E 06-1.1 E-072-.-5 07 4.7E-07 5.SE-07 Q+ 7.2E-7.2E 074.2E-09 1.9E-08 3.7E-08 Qg 2.3E-1.4E 078,.J&-093-. ..g +o 3.9E-09 9.4E-09 09 4.2E-1.2E 087:-2-E-104,.7 1-3.SE-10 1.2E-09 lO 4.0E-3.5E 092-:4E-122.,.7 +2 1.1E-11 7.2E-11 1-1-.... .... t;-.... t;-t;-

"Cl :; 0.18 . :11 I ::c 0.16 *1 s 0.14 lj I 6 0.12 .i j 0.1 i *s I 8 0.08. 0.06 .! QI I r o.o4 *1 c QI :::! QI Cl.. DCPP: 10 Hz, AEP=l0-4 Distance (km) Enclosure 1 PG&E Letter OCL-15-035 Appendix A Page 5of13 -->8.0 Figure A 1.0-1: Deaggregation of the Reference Rock Site Hazard for 10 Hz Spectral Acceleration for the 1 E-4 Hazard Level.

0.25 N "' % s 0.2 -, IS I = 0.15 -

J:t 0.1 ' ., ; i N o.o5 c ., G1 Q,, 0 DCPP: 1 Hz, AEP=l0-4 ! ' Distance (km} Enclosure 1 PG&E Letter DCL-15-035 Appendix A Page 6 of 13 ------------------*-------------------* Figure A 1.0-2: Deaggregation of the Reference Rock Site Hazard for 1 Hz Spectral Acceleration for the 1 E-4 Hazard Level. PG&E Letter OCL-15-035 Appendix A Page 7of13 Table A2. 0-1: Mean and F ractiles of Hazard for the Control Point for Peak Acceleration _ Mean 5'" 16tn som 84tn 95tn 0.02 7.0E-02 4.4E-02 4.9E-02 7.5E-02 I 1.2E-01 1.2E-01 0.05 2.3E-02 1.1E-02 1.4E-02 2.3E-02 3.SE-02 3.SE-02 0.10 8.4E-03 3.5E-03 4.6E-03 8.4E-03 1.4E-02 1.5E-02 0.15 4.6E-03 1.6E-03 2.2E-03 4.3E-03 7.2E-03 I 8.5E-03 0.20 2.SE-03 9.1E-04 1.4E-03 2.?E-03 4.7E-03 5.7E-03 0.25 2.0E-03 5.2E-04 8.3E-04 1.?E-03 3.3E-03 4.2E-03 *-* 0.30 1.4E-03 2.BE-04 4.9E-04 1.2E-03 2.4E-03 3.0E-03 *-0.40 7.3E-04 1.2E-04 2.4E-04 6.5E-04 1.5E-03 2.0E-03 0.50 4.3E-04 5.5E-05 1.2E-04 3.4E-04 8.SE-04 1.3E-03 ,....._ 0.60 2.8E-04 2.4E-05 5.SE-05 2.1E-04 5.5E-04 7.9E-04 0.70 1.7E-04 1.0E-05 2.?E-05 1.1E-04 3.SE-04 5.BE-04 .. 0.85 8.6E-05 4.1E-06 1.2E-05 5.7E-05 2.2E-04 3.5E-04 1.00 4.9E-05 1.BE-06 6.4E-06 3.1E-05 1.2E-04 ! 1.9E-04 1.20 2.6E-05 5.1E-07 2.1E-06 1.SE-05 7.1E-05 1.3E-04 1.40 1.4E-05 2.3E-07 1.0E-06 7.6E-06 3.?E-05 7.1 E-05 1.60 8.2E-06 7.8E-08 4.0E-07 4.0E-06 2.3E-05 4.7E-05 1.80 4.9E-06 3.5E-08 2.0E-07 2.2E-06 1.4E-05 3.1 E-05 2.0 3.2E-06 1.6E-08 9.5E-08 1.3E-06 8.9E-06 2.1 E-05 2.5 1.2E-06 2.1 E-09 1.6E-08 3.5E-07 3.3E-06 8.4E*06 3.0 5.0E-07 5.2E-10 3.4E-09 9.6E-08 1.3E-06 3.5E-06 4.0 1.3E-07 7.0E-11 4.3E-10 1.2E-08 2.3E-07 8.4E-07 5.0 3.8E-08 1.6E-11 1.1E-10 2.9E-09 7.2E-08 3.0E-07 -. - PG&E Letter DCL-15-035 Appendix A Page 8 of 13 Table A2.0-2: Mean and Fractiles of Hazard for the Control Point for 20 Hz Spectral Acceleration 20 Hz Mean 5rn 16tn sotn 841n 95rn PSA (g) 0.02 7.5E-02 4.4E-02 4.8E-02 7.1E-02 1.SE-01 1.6E-01 0.05 2.6E-02 1.3E-02 1.6E-02 2.6E-02 5.1E-02 5.5E-02 --0.10 1.0E-02 4.4E-03 5.7E-03 1.0E-02 2.1E-02 2.4E-02 0.15 5.SE-03 2.1E-03 2.9E-03 5.5E-03 1.2E-02 1.4E-02 >-------0.20 3.6E-03 1.2E-03 1.7E-03 3.6E-03 7.9E-03 9.4E-03 0.25 2.5E-03 7.1 E-04 1.1E-03 2.4E-03 5.8E-03 7.0E-03 0.30 1.8E-03 4.3E-04 7.2E-04 1.8E-03 4.2E-03 5.2E-03 0.40 1.0E-03 2.0E-04 3.6E-04 1.0E-03 2.7E-03 3.5E-03 I 0.50 6.6E-04 7.7E-05 1.6E-04 5.7E-04 1.8E-03 2.5E-03 I 0.60 4.0E-04 3.SE-05 8.7E-05 3.4E-04 1.2E-03 1.SE-03 0.70 2.7E-04 2.0E-05 5.0E-05 2.3E-04 9.3E-04 1.4E-03 0.85 1.6E-04 7.9E-06 2.3E-05 1.3E-04 5.9E-04 9.6E-04 1.00 9.4E-05 3.2E-06 1.1 E-05 6.7E-05 3.4E-04 6.0E-04 1.20 5.1E-05 1.3E-06 4.9E-06 3.7E-05 2.4E-04 4.4E-04 1.40 2.9E-05 4.1 E-07 1.9E-06 1.8E-05 1.4E-04 2.7E-04 1.60 1.7E-05 2.1E-07 1.0E-06 1.1E-05 9.1E-05 1.9E-04 1.80 1.1E-05 7.4E-08 4.5E-07 6.1E-06 6.0E-05 1.3E-04 2.0 7.2E-06 3.8E-08 2.4E-07 3.8E-06 3.9E-05 9.1E-05 2.5 2.8E-06 9.5E-09 6.2E-08 1.3E-06 1.6E-05 4.3E-05 3.0 1.3E-06 2.0E-09 1.SE-08 4.8E-07 7.0E-06 2.0E-05 4.0 3.3E-07 2.SE-10 2.1 E-09 8.5E-08 1.6E-06 5.7E-06 -5.0 1.2E-07 5.9E-11 I I 4.3E-10 2.2E-08 5.SE-07 2.4E PG&E Letter DCL-15-035 Appendix A Page 9of13 Table A2.0-3: Mean and Fractiles of Hazard for the Control Point for 10 Hz Spectral Acceleration ------*--.. ------10 Hz Mean 5th 16th so th a41n 95th PSA (g) --* 0.02 1.1 E-01 6.9E-02 7.SE-02 1.1 E-01 I 2.1 E-01 2.2E-01 -0.05 4.0E-02 2.0E-02 2.3E-02 4.1E-02 7.BE-02 8.4E-02 0.10 1.6E-02 6.9E-03 8.BE-03 1.7E-02 3.3E-02 3.6E-02 0.15 9.3E-03 3.5E-03 4.7E-03 9.2E-03 1.9E-02 2.1E-02 0.20 6.2E-03 2.1E-03 2.9E-03 6.1E-03 1.3E-02 1.5E-02 0.25 4.5E-03 1.4E-03 2.0E-03 4.1E-03 9.7E-03 1.1E-02 -----0.30 3.3E-03 9.3E-04 1.4E-03 3.2E-03 7.1E-03 8.6E-03 0.40 2.1E-03 4.?E-04 7.9E-04 2.0E-03 4.8E-03 5.9E-03 0.50 1.4E-03 2.3E-04 4.2E-04 1.2E-03 3.4E-03 4.3E-03 0.60 9.5E-04 1.6E-04 3.0E-04 8.5E-04 2.4E-03 3.2E-03 0.70 6.7E-04 8.4E-05 1.8E-04 6.0E-04 1.9E-03 2.6E-03 0.85 4.4E-04 3.6E-05 8.5E-05 3.?E-04 1.3E-03 1.9E-03 1.00 2.9E-04 1.?E-05 4.4E-05 2.2E-04 8.SE-04 1.3E-03 1.20 1.?E-04 8.3E-06 2.3E-05 1.3E-04 6.6E-04 9.7E-04 1.40 1.0E-04 3.8E-06 1.2E-05 7.4E-05 4.3E-04 6.SE-04 1.60 6.5E-05 1.6E-06 5.SE-06 4.6E-05 3.1E-04 4.9E-04 1.80 4.4E-05 8.5E-07 3.4E-06 3.1E-05 2.2E-04 3.7E-04 .-2.0 2.9E-05 4.7E-07 2.0E-06 2.0E-05 1.5E-04 2.7E-04 2.5 1.2E-05 7.9E-08 4.6E-07 6.9E-06 7.2E-05 1.4E-04 3.0 6.1E-06 2.9E-08 2.0E-07 3.5E-06 3.4E-05 7.6E-05 4.0 1.?E-06 4.0E-09 3.4E-08 7.2E-07 9.4E-06 2.4E-05 5.0 6.4E-07 5.6E-10 5.3E-09 2.0E-07 3.9E-06 1.1E-05 PG&E Letter DCL-15-035 Appendix A Page 10 of 13 Table A2.0-4: Mean and Fractiles of Hazard for the Control Point for 5 Hz Spectral Acceleration 5 Hz Mean *:rn----5 16111-*--501" g4tn 95m PSA (g) 0.02 1.4E-01 9.6E-02 1.0E-01 1.4E-01 2.4E-01 2.SE-01 0.05 5.4E-02 2.8E-02 3.1E-02 5.6E-02 9.0E-02 9.4E-02 --**----->-------* 0.10 2.1E-02 9.SE-03 1.2E-02 2.2E-02 3.6E-02 3.9E-02 0.15 1.2E-02 4.8E-03 6.1E-03 1.2E-02 2.0E-02 2.3E-02 0.20 7.9E-03 3.0E-03 4.0E-03 7.9E-03 1.4E-02 1.6E-02 0.25 5.7E-03 2.0E-03 2.8E-03 5.3E-03 1.0E-02 1.2E-02 0.30 4.4E-03 1.4E-03 2.0E-03 4.2E-03 7.SE-03 9.0E-03 -0.40 2.BE-03 7.SE-04 1.2E-03 2.7E-03 5.0E-03 6.1E-03 0.50 2.0E-03 4.8E-04 7.8E-04 1.7E-03 3.6E-03 4.5E-03 -0.60 1.4E-03 3.0E-04 5.1E-04 1.3E-03 2.6E-03 3.3E-03 0.70 1.0E-03 1.9E-04 3.3E-04 8.8E-04 2.1E-03 2.7E-03 0.85 6.9E-04 1.0E-04 1.9E-04 5.8E-04 1.SE-03 2.0E-03 1.00 4.9E-04 5.9E-05 1.2E-04 3.7E-04 9.9E-04 1.4E-03 1.20 3.1E-04 2.SE-05 5.6E-05 2.4E-04 7.6E-04 1.1E-03 1.40 2.0E-04 1.SE-05 3.SE-05 1.4E-04 5.1E-04 7.SE-04 1.60 1.3E-04 7.3E-06 1.9E-05 9.4E-05 3.8E-04 5.8E-04 1.80 9.0E-05 4.2E-06 1.2E-05 6.2E-05 2.?E-04 4.3E-04 2.0 6.4E-05 1.8E-06 6.2E-06 4.2E-05 2.0E-04 3.3E-04 2.5 2.8E-05 4.9E-07 2.1E-06 1.7E-05 9.9E-05 1.8E-04 -----** 3.0 1.4E-05 1.9E-07 9.2E-07 8.6E-06 5.1E-05 9.6E-05 4.0 4.SE-06 2.7E-08 1.SE-07 2.1E-06 1.5E-05 3.2E-05 ---. -5.0 1.?E-06 3.BE-09 3.3E-08 6.6E-07 6.4E-06 1.SE-05 ---- PG&E Letter DCL-15-035 Appendix A Page 11of13 Table A2.0-5: Mean and Fractiles of Hazard for the Control Point for 2.5 Hz Spectral Acceleration 0.02 2.0E-01 l 1.SE-01 1.6E-01 1.8E-01 2.2E-01 2.4E-01 -----+ 0.05 7.4E-02 4.5E-02 4.9E-02 5.7E-02 6.9E-02 7.7E-02 ---+----l 0.10 2.9E-02 1.5E-02 1. 7E-02 2.1 E-02 2. ?E-02 3.2E-02 0.15 1.6E-02 7 .2E-03 8.SE-03 1.1 E-02 1.4E-02 1. 7E-02 0.20 1.0E-02 4.4E-03 5.3E-03 7.0E-03 9.2E-03 1.1 E-02 0.25 7.1E-03 3.0E-03 3.7E-03 4.9E-03 6.7E-03 8.1E-03 ---+-------+-----+----t-------+------+-----t 0.30 5.3E-03 2.0E-03 2.5E-03 3.SE-03 4.8E-03 5.9E-03 --4--------l 0.40 3.3E-03 1.1 E-03 1.5E-03 2.2E-03 3.1 E-03 3.8E-03 -----+-----l 0.50 2.3E-03 6.9E-04 9.3E-04 1.4E-03 2.2E-03 2.8E-03 --+-----+----+------I 0.60 1.6E-03 4.2E-04 5.9E-04 9.4E-04 1.SE-03 2.0E-03 0.70 1.2E-03 3.0E-04 4.3E-04 7.1E-04 1.2E-03 1.6E-03 ---1-----+-----+-------+----+-------I 0.85 8.3E-04 1.6E-04 2.4E-04 4.4E-04 8.2E-04 1.1 E-03 1.00 6.1 E-04 8.2E-05 1.3E-04 2.6E-04 5.2E-04 7.8E-04 1.20 3.7E-04 4.3E-05 7.4E-05 1.7E-04 3.7E-04 5.9E-04 1.40 2.SE-04 2.4E-05 4.1 E-05 9.7E-05 2.3E-04 3.9E-04 1.60 1.8E-04 1.4E-05 2.6E-05 6.6E-05 1.7E-04 2.9E-04 l-------+-------1*-1.80 1.3E-04 7.8E-06 1.5E-05 4.2E-05 1.2E-04 2.2E-04 2.0 9.4E-05 4.2E-06 9.1 E-06 2.BE-05 8.3E-05 1.6E-04 -*+------+----+-----;---------+-------t 2.5 4.6E-05 1.3E-06 3.3E-06 1.2E-05 4.0E-05 7.9E-05 3.0 2.4E-05 4.0E-07 1.2E-06 5.0E-06 2.0E-05 4.4E-05 4.0 8.4E-06 5.5E-08 1.9E-07 1.2E-06 5.8E-06 1.5E*05 5.0 3.5E-06 1.4E-08 5.7E-08 3.9E-07 f2.4E-06 6.BE-06 '------'-----'---------'------'-----'-----*- PG&E Letter DCL-15-035 Appendix A Page 12of13 Table A2.0-6: Mean and Fractiles of Hazard for the Control Point for 1 Hz Spectral Acceleration 1.0 Hz Mean 5tn 15tti sotn a4tn ! 95tn PSA (g) 0.02 6.3E-02 3.0E-02 3.2E-02 6.4E-02 I 7.2E-02 7.5E-02 -------* 0.05 1.7E-02 6.6E-03 7.7E-03 1.4E-02 1.7E-02 1.SE-02 I 0.10 5.3E-03 1.7E-03 2.3E-03 4.2E-03 5.6E-03 6.2E-03 0.15 2.7E-03 6.5E-04 1.0E-03 1.9E-03 2.9E-03 I 3.4E-03 0.20 1.7E-03 3.1E-04 5.5E-04 1.2E-03 1.9E-03 2.3E-03 0.25 1.1E-03 1.?E-04 3.4E-04 7.6E-04 1.3E-03 1.7E-03 .. 0.30 8.1E-04 8.2E-05 1.BE-04 4.BE-04 9.5E-04 ! 1.3E-03 0.40 4.8E-04 2.7E-05 7.6E-05 2.5E-04 6.0E-04 8.4E-04 0.50 2.8E-04 1.2E-05 3.6E-05 1.3E-04 3.6E-04 5.4E-04 0.60 1.8E-04 4.7E-06 1.6E-05 7.1E-05 2.2E-04 3.5E-04 0.70 1.2E-04 2.4E-06 9.1E-06 _j.5E-05 J 1.SE-04 2.6E-04 0.85 7.3E-05 9.1E-07 3.BE-06 2.3E-05 8.7E-05 1.6E-04 1.00 4.3E-05 3.4E-07 1.5E-06 1.1E-05 4.6E-05 8.BE-05 I 1.20 2.4E-05 1.2E-07 6.6E-07 5.8E-06 2.9E-05 5.9E-05 1.40 1.4E-05 4.2E-08 2.6E-07 2.7E-06 1.SE-05 3.3E-05 1.60 9.2E-06 1.BE-08 1.3E-07 1.SE-06 9.8E-06 2.2E-05 -1.80 5.9E-06 7.7E-09 6.0E-08 8.5E-07 6.2E-06 1.4E-05 -. .----2.0 4.0E-06 3.3E-09 2.BE-08 4.BE-07 3.9E-06 9.5E-06 2.5 1.7E-06 6.7E-10 6.BE-09 1.SE-07 1.SE-06 4.2E-06 -3.0 7.9E-07 1.4E-10 1.6E-09 5.0E-08 5.9E-07 1.8E-06 4.0 2.2E-07 1.3E-11 1.?E-10 6.2E-09 1.1 E-07 4.4E-07 5.0 8.2E-08 2.6E-12 4.1 E-11 1.5E-09 3.SE-08 1.7E-07 PG&E Letter DCL-15-035 Appendix A Page 13of13 Table A2.0-7: Mean and Fractiles of Hazard for the Control Point for 0.5 Hz Spectral Acceleration -0.5 Hz Mean 5tn 16tn som 84tn 95tn PSA (g} 0.02 2.0E-02 7.8E-03 9.0E-03 1.BE-02 2.2E-02 2.4E-02 ---*-* 0.05 4.5E-03 1.3E-03 1.?E-03 3.SE-03 4.?E-03 5.5E-03 0.10 1.3E-03 2.0E-04 3.4E-04 8.7E-04 1.5E-03 2.0E-03 0.15 5.6E-04 4.9E-05 1.1 E-04 3.0E-04 7.0E-04 1.1E-03 0.20 3.1 E-04 1.6E-05 4.0E-05 1.5E-04 4.2E-04 7.1E-04 0.25 1.8E-04 5.1E-06 1.5E-05 7.0E-05 2.5E-04 4.6E-04 0.30 1.2E-04 2.3E-06 7.5E-06 3.6E-05 1.6E-04 3.0E-04 0.40 5.6E-05 4.8E-07 2.1 E-06 1.4E-05 7.5E-05 1.7E-04 0.50 2.9E-05 9.8E-08 6.2E-07 5.2E-06 3.6E-05 9.2E-05 0.60 1.6E-05 4.1E-08 2.4E-07 2.4E-06 1.9E-05 5.4E-05 0.70 1.0E-05 1.1E-08 9.1 E-08 1.1E-06 1.2E-05 3.4E-05 0.85 5.5E-06 3.1E-09 I 2.9E-08 4.5E-07 5.4E-06 1.8E-05 ----1.00 3.0E-06 1.0E-09 1.1 E-08 1.7E-07 2.4E-06 1.0E-05 1.20 1.SE-06 2.3E-10 3.6E-09 7.5E-08 1.3E-06 5.5E-06 I 1.40 8.7E-07 8.2E-11 1.2E-09 2.8E-08 5.3E-07 2.7E-06 1.60 5.2E-07 3.2E-11 5.2E-10 1.3E-08 3.0E-07 1.7E-06 1.80 3.2E-07 1.3E-11 2.3E-10 6.2E-09 1.7E-07 1.1E-06 2.0 2.1 E-07 4.3E-12 8.3E-11 2.SE-09 8.9E-08 6.5E-07 I 2.5 8.0E-08 6.?E-13 9.3E-12 6.3E-10 2.9E-08 2.SE-07 3.0 3.6E-08 1.1E-13 1.1 E-12 1.4E-10 9.6E-09 9.?E-08 4.0 9.3E-09 3.8E-14 5.4E-12 1.5E-09 2.1E-08 I --5.0 3.2E-09 9.7E"16 2.3E-15 5.3E-13 3.9E-10 6.9E-09 PG&E Letter DC L-15-035 Appendix A Page 14of13 Table A3. 0-1: Median Amplification Factors and Epistemic Uncertainty for the Control Point Using the Empirical Site Response Approach. (Amplification is with respect to f k *t "th V 760 I d k 0 041 onds). a re erence roe s1ew1 S30 = ms an appa = sec logarithmic Median Standard Deviation Freq (Hz) Amplification {LN units) 100.00 0.74 0.20 50.00 0.73 0.20 33.30 0.70 0.20 20.00 0.59 0.20 13.30 0.59 0.21 10.00 0.59 0.22 6.67 0.61 0.22 5.00 0.68 0.22 4.00 0.79 0.22 3.33 0.88 0.22 2.50 1.21 0.22 2.00 1.21 0.22 1.33 1.21 0.23 1.00 1.00 0.24 0.67 1.00 0.26 0.50 1.00 0.27 0.33 1.00 0.35 0.20 1.00 0.35 0.10 1.00 0.35 PG&E Letter DCL-15-035 Appendix B Page 1 of 9 Appendix B-Long Term Seismic Program Seismic Margin Spectrum B 1.0 Introduction Enclosure 1 PG&E letter DCL-15-035 Appendix B Page 2 of 9 The purpose of this Appendix is to document the seismic margins associated with the 1988 Long Term Seismic Program (LTSP) evaluation of Diablo Canyon Power Plant (DCPP) (see the 1988 DCPP LTSP Final Report (PG&E 1988), the 1991 Addendum to the DCPP LTSP Final Report (PG&E 1991 ), and the Supplement No. 34 of the Safety Evaluation Report (SER) for DCPP (NRC 1991 )). The resulting response spectrum, herein, is defined as the LTSP seismic margin spectrum. B2.0 Long Term Seismic Program Background License Condition No. 2.C.(7) of the DCPP Unit 1 operating license, required, in part that: "PG&E shall develop and implement a program to reevaluate the seismic design bases used for the DCPP." Pacific Gas and Electric Company's (PG&E's) seismic reevaluation effort in response to the license condition was titled the "Long Term Seismic Program." The LTSP included a seismic probabilistic risk assessment (SPRA) and a deterministic seismic margin assessment (SMA). The results of the L TSP are described in the 1988 LTSP Final Report (PG&E 1988) and the 1991 Addendum to the L TSP Final Report (PG&E 1991 ). The Nuclear Regulatory Commission's (NRC's) review and acceptance of the L TSP evaluations are documented in DCPP SER Supplement 34 (NRC 1991 ). B2 .1 L TSP Ground Motion Site-specific free-field ground motions were developed by PG&E based on the following (PG&E 1988, Chapters 2 through 4): (a) regional geology, seismology, geophysics, and tectonics investigations (b) characterization of seismic source (c) characterization of ground motions, using both empirical analysis and numerical modeling PG&E's horizontal site-specific 1988 L TSP response spectrum is shown in Figure 82.1-1(PG&E1988, Figure 7-2) and tabulated in Table B2.1-1. Note PG&E Letter DCL-15-035 Appendix B Page 3of9 that the 84th percentile response spectrum was used as input to the deterministic evaluations. Z.5 .5 5%Damplng P* / '\'\ 1977 Hoseri evaluation / \: (Newmark) / 19l'!8 84tn Percentile I \ " .'/ /./ "/ .............. _._ ........................ ........ _,_...._ ..................... ........ ._._ ......... ._ .1 .2 .& 2 5 10 Froquency ltli) 20 50 100 Figure 82. 1-1: Horizontal 1988 L TSP Response Spectrum for DC PP (From LTSP Final Report, Figure 7-2) PG&E Letter DCL-15-035 Appendix B Page 4 of 9 Table 82.1-1: Horizontal 1988 L TSP Response Spectrum for OCPP (5% 0 . ) 0 ampmq Period Frequency 84m Percentile Spectral Acceleration (sec.) (Hz) (g) 0.0250 40.000 0.830 0.0303 33.000 0.830 0.0400 25.000 0.964 0.0500 20.000 1.110 0.0700 14.286 1.344 0.0850 11.765 1.508 -.--0.1000 10.000 1.654 0.1200 8.333 1.819 0.1400 7.143 1.918 0.1500 6.667 1.947 0.1700 5.882 1.976 0.2000 5.000 2.006 0.2500 4.000 2.015 0.3000 3.333 1.962 0.4000 2.500 1.763 0.5000 2.000 1.554 0.7500 1.333 1.109 1.0000 1.000 0.831 1.5000 0.667 0.524 2.0000 0.500 0.356 B2.2 L TSP HCLPF Capacities The high-confidence-low-probability-of-failure (HCLPF) capacities of structures, systems, and components that were found to be governing in the deterministic seismic margin assessment associated with the implementation of the LTSP are described in Chapter 7 of the 1988 LTSP Final Report (PG&E 1988) and updated in Chapter 7 of the 1991 Addendum of the L TSP Final Report (PG&E 1991). The fragilities and HCLPF capacities for DCPP structures, systems, and components are defined based on the 5 percent damped horizontal spectral acceleration value, averaged over the frequency range of 3.0 to 8.5 Hz. This is illustrated in Figure B2.2-1 (based on Figure 7-40 from the 1988 LTSP Final Report -PG&E 1988).

Average spectral acceleration from 3 to 8.5 Hz 3 8.5 Frequency (Hz) Enclosure 1 PG&E Letter DCL-15-035 Appendix 8 Page 5 of 9 Figure 82.2-1: Frequency Range Associated with HCLPF Capacities for DCPP (From PG&E 1988, Figure 7-40) 83.0 Minimum Seismic Margin As indicated m Tables 7-1 and 7-2 of the 1988 LTSP Final Report (PG&E 1988), the turbine building is the structure with the lowest HCLPF capacity and the emergency diesel generator (EOG) control panels are the component whose failure could lead to significant seismic risk to the plant with the lowest HCLPF capacity. The HCLPF capacities of these structures, systems, and components were updated by PG&E using the conservative deterministic failure margins method (PG&E 1990) and summarized in Table A 7-1 of the 1991 Addendum to L TSP Final Report (PG&E 1991). The HCLPF capacities for the turbine building and the EOG control panels are listed in Table 83.0-1. PG&E Letter DCL-15-035 Appendix 8 Page 6 of 9 Table 83.0-1: Limiting HCLPF Capacities for DCPP (PG&E 1988 and PG&E 1991) SSC 841h Percentile HCLPF Capacity (g) Name PG&E 19881 PG&E --Turbine Building 2.21 2.89 EOG Control Panels 2.69 2.62 Since the average 5 percent damped spectral acceleration for the 84th percentile 1988 LTSP horizontal response spectrum is 1.94 g (see Figure 82.2-1) and the HCLPF capacity for the limiting structure. system, and components (EOG control panels) is 2.62 g, the minimum seismic margin is 2.62 g/1.94 g = 1.35. Note that Section 3.8.1.5 of the NRC's SER associated with the 1988 L TSP (NRC 1991) states: "the staff generally agrees with the PG&E's statement that all components whose failure could lead to seismic risk to the plant have at least a margin of 40 percent when their HCLPF capacities are compared with the 84-percent, site-specific, ground-motion demand." Therefore, the use of a minimum seismic margin of 1.35 is conservative relative to the NRC's conclusions for the 1988 LTSP. 84.0 LTSP Seismic Margin Spectrum The resulting LTSP seismic margin spectrum is the product of the 84th percentile 1988 L TSP ground motion response spectrum (Table 82.1-1) and the minimum seismic margin from Section 83.0 (1.35). The LTSP seismic margin spectrum is shown in Figure 84.0-1 and tabulated in Table 84.0-1. 1988 HCLPF capacities are from Tables 7-1 and 7-2 of the 1988 L TSP Final Report (PG&E 1988). 1991 HCLPF capacities are from Table A7-1 of the 1991 Addendum to the l TSP Final Report (PG&E 1991). § c .2 ID 3 u c( u ID a. ..,, 30 2.5 2.0 t.5 1.0 0.5 0.0 0.10 I// .... _ v I v II II l/ I I I 00 Frequency (Hz) !"--. r---1\ \ I'\ Enclosure 1 PG&E Letter DCL-15-035 Appendix B Page 7 of 9 f -L TSP Seismic \ I\ II.. 10.00 100.00 Figure 84.0-1: LTSP Seismic Margin Spectrum for DCPP (5% Damping)

• --Enclosure 1 PG&E Letter DCL-15-035 Appendix B Page 8 of 9 Table 84.0-1: LTSP Seismic Margins Spectrum for DCPP (5% Damping} Period Frequency Spectral Acceleration (sec} (Hz} (g} 0.0100 *I----149£-=0°0°0°0° 1.121 0.0250 1.121 0.0303 I 33.0000 1.121 0.0400 25.0000 1.301 0.0500 20.0000 1.499 0.0700 14.2857 1.814 0.0850 11.7647 2.036 0.1000 10.0000 2.233 0.1200 8.3333 2.456 0.1400 7.1429 2.589 0.1500 6.6667 2.628 0.1700 5.8824 2.668 . ----0.2000 5.0000 2.708 0.2500 4.0000 2.720 0.3000 3.3333 2.649 0.4000 2.5000 2.380 0.5000 2.0000 2.098 -* 0.7500 1.3333 1.497 1.0000 1.0000 1.122 1.5000 0.6667 0.707 2.0000 0.5000 0.481 85.0 References 85.1 Pacific Gas and Electric Company Enclosure 1 PG&E Letter DCL-15-035 Appendix B Page 9 of 9 (a) PG&E 1988, PG&E Report, "Final Report of the Diablo Canyon Long Term Seismic Program for the Diablo Canyon Power Plant," Enclosure to PG&E Letter DCL-88-192, "Long Term Seismic Program Completion," dated July 31, 1988 (b) PG&E 1990, PG&E Report, "Additional Deterministic Evaluations Performed to Assess Seismic Margins of the Diablo Canyon Power Plant, Units 1 and 2," Enclosure to PG&E Letter DCL-90-226, "Long Term Seismic Program Additional Deterministic Evaluations," dated September 18, 1990 (c) PG&E 1991, PG&E Report, "Addendum to the 1988 Final Report of the Diablo Canyon Long Term Seismic Program," Enclosure to PG&E Letter DCL*91-027, "Addendum to Long Tenn Seismic Program Final Report," dated February 13, 1991 85.2 Nuclear Regulatory Commission (a) NRC 1991. "Safety Evaluation Report related to the operation of Diablo Canyon Nuclear Power Plant, Units 1 and 2, Docket Nos. 50-275 and Pacific Gas and Electric Company," NUREG-0675, Supplement No. 34, dated June 1991 PG&E Letter DCL-15-035 Appendix C Page 1of18 Appendix C -PPRP Endorsements PG&E Letter DCL-15-035 Appendix C Page 2 of 18 Diablo Canyon Seismic Source Characterization SSHAC Project Participatory Peer Review Panel Closure Letter March 10, 2015 Mr. Kent S. Ferre Project Manager Pacific Gas & Electric Company 245 Market St. San Francisco, CA 94177 Enclosure 1 PG&E Letter DCL-15-035 Appendix C Page 3 of 18

SUBJECT:

Diablo Canyon Seismic Source Characterization SSHAC Project Participatory Peer Review Panel Closure Letter

Dear Mr. Ferre,

The Participatory Peer Review Panel (PPRP, the "Panel") for the Diablo Canyon Seismic Source Characterization (SSC) SSHAC Project (the "DCPP SSC Project") is pleased to issue this PPRP Closure Letter containing our findings with respect to the project. The four Panel members (Kevin J. Coppersmith, Steven M. Day, Neal W. Driscoll, and Thomas K. Rockwell) participated in the Project in a manner fully consistent with the SSHAC Guidance 1 for a SSHAC Level 3 study. The Panel was actively engaged in all phases and activities of the Project's implementation, including the development of the Project Plan, review of analyses performed by the Technical Integration (Tl) Team to support the evaluation and integration processes, review of interim products, and review of the draft project report and the final project report. Consistent with regulatory guidance for SSHAC projects, the role of the PPRP is to conduct a review of both the process followed and the technical assessments made by the Tl Team. Accordingly, this letter documents the activities that the PPRP has undertaken in its review of the Project, its review of the adequacy of the process followed, and its findings relative to the technical adequacy of the resulting SSC model. Consistent with SSHAC Guidance, the Panel was fully engaged in peer-review interactions with the DCPP SSC Tl Team throughout the entire project from development of the Project Plan through finalization the Project Report. The participatory peer review process entails the continual review of a project from its start to its completion. Thus, proper implementation requires adequate opportunity during the conduct of the study for the PPRP to understand the data, models, and methods being evaluated; the analyses performed for the study; the Tl Team's integration activities that lead to SSC models and uncertainties; and the completeness and clarity of the technical 1 Budnitz, R.J .. G. Apostolakis, D M. Boore, L.S. Cluff, KL Coppersmith, CA Cornell, and P.A. Morris (1997). Recommendations for Probabilistic Seismic Hazard Analysis: Guidance on Uncertainty and me Use of Experts (known as the "Senior Seismic Hazard Analysis Committee Report'", or "SSHAC Guideline"), NUREG/CR-6372, U.S. Nuclear Regulatory Commission, TIC: 235076, Washington, D.C. NRG (2012). Practical Jmpfementation Guidelines for SSHAC Level 3 and 4 Hazard Studies, NUREG-2117, U.S. Nuclear Regulatory Commission, Washington. D.C. DCPP SSC PPRP Closure Letter 3-10-15 Page 1 Enclosure *1 PG&E Letter DCL-15-035 Appendix C Page 4 of 18 justifications given in the documentation. Participatory review also involves opportunities for the PPRP to provide its reviews and comments in written and verbal form during the conduct of the project, such that the suggestions and recommendations made by the Panel can be considered by the Tl Team in a timely fashion prior to completion of the work. The meetings attended and observed by the PPRP for the DCPP SSC project are summarized in the table below. The PPRP assumed an active participant role in Workshop #3 and the PPRP Briefings. . Meeting Type Date(s) Topic(s) Kick off meeting August 25, 2011 Kick off meetinQ Workshop November 29 -Workshop#1 December 1. 2011 WorkinQ Meetinq March 28, 2012 Characteristic earthauake review Working Meeting April 11. 2012 Logic tree and sensitivity for magnitude PDF and earthquake recurrence Working meeting May 14, 2012 SSC work plan review, overall logic tree structure Project and Workshop #2 planning, logic tree Working Meeting June 19-20, 2012 structure, sensitivity analyses, Hosgri, Los Osos, San Luis Bav. and Shoreline looic trees Working Meeting October 25-26, 2012 Workshop #2 planning, logic tree sensitivity review -*-Workshop November 6-8, 2012 Workshop #2 Working Meeting December 11, 2012 Review Workshop 2. 2013 plan. data needs table Working Meeting February 20. 2013 2013 Schedule and Assignments. Offshore seismic stratigrai:ihv project PE presentation Working Meeting September 20, 2013 Alternative fault model evaluation Working Meeting November 5-6, 2013 Presentation of draft SSC Model V2 Working Meeting March 5, 2014 Rupture Models, Sam Johnson PE presentation, Recurrence model Workshop March 25-27, 2014 Workshop #3 Modifications to Preliminary Fault and Working Meeting June 23-24, 2014 Deformation models, open items following Preliminary SSC Model PPRP Briefing July 24-25, 2014 DCPP SSC Model Final PPRP Briefinq, Part 1 PPRP Briefing October 31. 2014 DCPP SSC Model Final PPRP Briefing, Part 2. Time Dependency Model The PPRP, collectively and individually, understood fully the SSHAC Guidance for a structured participatory peer review and the requirements for a SSHAC Level 3 project; had full and frequent access to information and interacted extensively with the Tl Team throughout the project: provided peeMeview comments at multiple stages; and, as documented within the final report, was fully engaged to meet its peer-review obligations in an effective way. The Panel concludes that its ongoing review and DCPP SSC PPRP Closure Letter 3-10-15 Page2 PG&E Letler DCL-15-03S Appendix C Pai;!<! 5 of 18 feedback interactions with the Tl Team during the conduct of the DCPP SSC project activities fully met the expectations for a SSHAC Level 3 study. SSHAC Process Review Fundamentally. the question of whether or not a project follows a proper SSHAC Level 3 process is answered by comparing the process used with the process outlined generally in the SSHAC implementation guidance issued by the NRC. NRC (2012, Table 4-1) identifies the essential steps in a SSHAC Level 3 study that define the minimum required activities: 1. Select SSHAC Level 2. Develop Project Plan 3. Select project participants 4. Develop project database 5. Hold workshops (minimum of three, focused on available data, alternative models. and feedback) 6. Develop preliminary model(s) and Hazard Input Document (HID) 7. Perform preliminary hazard calculations and sensitivity analyses 8. Finalize models in light of feedback 9. Perform final hazard calculations and sensitivity analyses 10. Develop draft.and final project report 11. Participatory peer review of entire process Review of the project documentation, as well as ongoing participatory peer review throughout the project, leads to the conclusion that the essential steps of a SSHAC Level 3 process have been followed in the DCPP SSC Project. For example, a Project Plan was issued at the start of the project that outlined the project activities and the roles and responsibilities of all project participants; a major effort was devoted to developing a project database that was accessible to the Tl Team; three topical workshops were held to identify available data, to discuss alternative methods and models, and to present feedback based on preliminary interpretations; preliminary models were developed and seismic hazard calculations conducted to provide additional feedback to the Tl Team; draft and final reports were developed that documented the process followed and the technical assessments made; and a peer review process was conducted that included both participatory aspects and late-stage reviews (e.g., review of the draft report). In light of due consideration of the essential elements of a SSHAC process and the specific manner in which the DCPP SSC Project was conducted, the Panel concludes that the project performed all essential steps consistent with current state-of-practice guidance for a SSHAC Level 3 process. As explained in NUREG-2117 (NRC, 2012). the SSHAC process consists of two important activities, described as follows: DCPP SSC PPRP Closure Letter 3-10-15 Page3 PG&E Letter DCL-15-035 Appendii< C Page 6of 18 "The fundamental goal of a SSHAC process is to carry out properly and document completely the activities of evaluation and integration, defined as:

• Evaluation: The consideration of the complete set of data, models, and methods proposed by the larger technical community that are relevant to the hazard analysis.
• Integration: Representing the center, body, and range of technically defensible interpretations in light of the evaluation process (i.e., informed by the assessment of existing data, models, and methods)." These activities are essential to any SSHAC study and the Panel has followed the DCPP SSC Project closely to ensure that both activities have been adequately conducted. A third key activity of a SSHAC process is the documentation phase, which ensures that all evaluation and integration activities are properly supported and captured in the written record. During the Evaluation phase of the DCPP SSC Project. the Tl Team considered new data, models, and methods that have become available in the technical community in recent years. Importantly, the Tl Team evaluated the wealth of onshore and offshore data that have recently been collected as part of the AB 1632 studies required by the State of California, as well as numerous data collection activities conducted by federal and state researchers such as the USGS and California Geological Survey. Workshop #1 was devoted to reviewing these disparate datasets and to identifying which data could be used to develop the SSC model. Continuing the evaluation process, Workshop #2 focused on alternative methods and models that pertain to the hazard-significant SSC issues. Significant representation of these alternative viewpoints was made by the participation of resource and proponent experts at the workshop. The Panel concludes that the Tl Team conducted an adequate evaluation process. The Integration phase of the project entails the building of the SSC model to capture current knowledge and uncertainties. Care was given in the model-building process to appropriately distinguish between epistemic uncertainties and aleatory variability. The Tl Team conducted multiple working meetings and other interactions to ensure that the center, body, and range of technically defensible interpretations were included in the SSC model. Importantly, the Team also received appropriate communications from the Project Technical Integrator (PTI) regarding the required elements of the SSC model needed for consistency with the ground motion models being developed in parallel as part of the Southwest United States Ground Motion Characterization Project. A preliminary SSC model was developed prior to Workshop #3 and hazard calculations were conducted for purposes of sensitivity analysis feedback. At Workshop #3, the PPRP was given the opportunity to provide their feedback on the preliminary model and to challenge the Tl Team with respect to the technical justifications for their SSC model assessments and associated uncertainties. The Tl Team used the feedback gained from the hazard calculations and PPRP comments to prioritize their efforts in the final SSC model development process. The tectonic complexity of the DCPP study region requires a complex SSC model to completely and appropriately capture current DCPP SSC PPRP Closure letter 3-10-15 Page 4 PG&E Letter DCL-15-035 Appendix C Page 7 of 18 knowledge and uncertainties. Efforts were made to simplify the models when it could be shown that detailed characterization would not lead to significant differences in the hazard results. The Panel concludes that such simplifications were justified and appropriate. In support of the Documentation phase of the project, the Tl Team developed a comprehensive Draft Report that was provided to the PPRP for detailed review. To ensure that schedule constraints for the project were met, the report was provided to the PPRP in major installments consisting of multiple chapters and appendices. The role of the Panel's review was specifically to ensure that all evaluation and integration activities were described completely, and that the SSC model was adequately justified technically. Written comments were provided by the PPRP to the Tl Team and, after revision of the report in light of those comments, written responses by the Team were provided to the PPRP to ensure proper closure of each comment. Based on the review of the evaluation and integration activities conducted by the Tl Team, as well as the documentation of these activities in the PSHA report. the PPRP concludes that the SSHAC process has been adequately conducted. SSHAC Technical Review The role of the PPRP in the review of the technical aspects of the project is specified in NUREG-2117 (USNRC, 2012) as follows: "The PPRP fulfills two parallel roles. the first being technical review. This means that the PPRP is charged with ensuring that the full range of data. models, and methods have been duly considered in the assessment and also that all technical decisions are adequately and documented. The responsibility of the PPRP is to provide clear and timely feedback to the TlffFI and project manager to ensure that any technical or process deficiencies are identified at the earliest possible stage so that they can be corrected. More commonly, the PPRP provides its perspectives and advice regarding the manner in which ongoing activities can be improved or carried out more effectively. In terms of technical review, a key responsibility of the PPRP is to highlight any data, models or proponents that have not been considered. Beyond completeness, it is not within the remit of the PPRP to judge the weighting of the logic-trees in detail but rather to judge the justification provided for the models included or excluded, and for the weights applied to the logic-tree branches. Consistent with this NRC guidance. the PPRP reviewed at multiple times during the project the Tl Team's evaluations of data, models, and methods, as well as the Team's development and technical justification for the SSC model These reviews DCPP SSC PPRP Closure letter 3-10-15 Page 5 PG&E Letter DCL-15-035 Appendix C Page 8of 18 included conference calls, post-workshop meetings, written comments. and the review of drafts of the PSHA report. Through these reviews, the PPRP communicated feedback to the Tl Team regarding data and approaches that did not appear to have been considered, suggestions for methods being used within the technical community that should be evaluated by the Team, and recommendations for ways that the documentation could be improved to strengthen the discussion of the technical bases for the assessments. Requirements for a successful integrat;on or model-building phase of a SSHAC Level 3 process are that it is informed by a complete evaluation of all relevant data. models, and methods during the evaluation phase of the project, that all assessments are technically defensible, and that the developed models are thoroughly documented so as to be transparent to users. During the course of the integration process, the Tl Team found that the available set of methods or model elements were not sufficient to properly and completely represent current knowledge and uncertainty in some components of the model. In those cases, the Tl Team developed a refined set of model elements or concepts that-although they are not radically different from current practice-provide approaches that the Team concluded were more effective in modeling technical aspects than available tools. For example, the SSC model includes a series of fault geometry models and rupture sources that span the range of credible interpretations of available data. Key aspects of these rupture sources are assessed based on a consideration of constraints from geologic, geomorphic. geophysical, and seismological data. A strong requirement of the SSHAC Guidance is that all elements of the SSC model must be completely documented and adequately justified technically. This is particularly true of new model elements that have not enjoyed the benefit of use on multiple projects or that have not been subject to peer review within the larger technical community. Particularly in those cases, the PPRP must ensure that the model elements are sufficiently justified and adequately defended in the project documentation. This has been the case in the DCPP SSC Project. Examples of new approaches include the use of a slip rate allocation approach to characterizing rupture sources. incorporating new magnitude frequency distributions, and the adoption of a non-Poisson temporal model. To review these concepts and applications to the SSC model, the PPRP was present as observers at workshops where these concepts were presented, provided written comments in response to those workshops. asked questions and provided feedback in a workshop environment regarding the adequacy of the technical justification for the models, participated in briefings and conference calls related to the topics, and provided detailed written comments related to the draft project report. Based on this process of participatory review throughout the course of the project. the PPRP concludes that the bases for the SSC model elements are technically defensible, and that the technical assessments and process for arriving at the model elements are adequately documented. Throughout the course of the PPRP review. the Tl Team was responsive to the questions, comments, and suggestions made by the PPRP relative to the technical aspects of the project. Therefore. the Panel concludes that the technical aspects of the DCPP SSC PPRP Closure Letter 3-10-15 Page 6 PG&E Letter DCL-15-035 Appendix C Page 9 of 18 projects have been adequately addressed and all written comments provided by the Panel, including those made following each workshop and those pertaining to the Draft Report, are hereby considered to be closed. Conclusion Based on our observation of the completeness and professional standard by which the evaluation and integration activities were conducted, the Panel concludes that the data. models, and methods within the larger technical community have been properly evaluated, and that the center, body, and range of technically defensible interpretations have been appropriately represented in the SSC model. Accordingly, the Panel concludes that both the process and technical aspects of the DCPP SSC assessment fully meet accepted guidance and current expectations for a SSHAC Level 3 study. We appreciate the opportunity to provide our review of the project. Sincerely. DCPP PPRP Members Kevin J. Coppersmith, Chair Steven M. Day Neal W. Driscoll Thomas K. Rockwell DCPP SSC PPRP Closure Letter 3-10-15 Page 7 PG&E Letter DCL-15-035 Appendix C Page 10ol18 Participatory Peer Review Panel Closure Letter, Southwest United States Ground Motion Characterization Level 3 SSHAC Project and Tl Team -PM Response to PPRP Closure Letter PG&E Letter DCL* 15-035 Southwestern United States Appendix c Ground Motion Characterization SSHAC Level 3 Page 11of18 TECHNICAL REPORT-Rev. 2 PPRP CLOSURE LETTER March 10, 2015 Dr. Carola Di Alessandro SWUS Project Manager GeoPentech, Inc. 525 N. Cabrillo Park Drive, Suite 280 Santa Ana, CA 92701

Subject:

Participatory Peer Review Panel Closure Letter, Southwest United States Ground Motion Characterization Level 3 SSHAC Project

Dear Dr. Di Alessandro:

The Participatory Peer Review Panel (PPRP, also referred to herein as the "Panel"} for the Southwest United States (SWUS) Ground Motion Characterization (GMC) Project is pleased to issue this PPRP Closure Letter. Herein we describe our participation in the SWUS GMC SSHAC level 3 project and present our findings. Pursuant to the guidelines for a SSHAC Level 3 study (NUREG/CR-6372; NUREG-2117), the PPRP was engaged at all stages of the project, including review of the final Project Plan, Workshop agendas and participant lists; the planning of the evaluation and model integration activities: and review of the project documentation. Throughout the project, the Panel reviewed and provided regular feedback on both the process followed, and the technical assessments made. by the Technical Integrator (Tl) Team. By this letter the Panel documents the activities it has performed in the course of its review, its assessment of the process followed relative to SSHAC Level 3 expectations, and its assessment of the technical rationale underlying the GMC model. The PPRP issued a previous letter dated February 24. 2015. In that letter, the Panel noted that there were limitations in the completeness and clarity of the project documentation. Those limitations were noted as exceptions to the Panel's finding that the project successfully met SSHAC Level 3 expectations. Since that time. the Tl Team has produced a final report, designated Rev2, addressing the final set of comments from the Panel (PPRP Submittal No. 3, February 20. 2015). The Panel has reviewed Rev2 (including a short addendum supplied to the PPRP in draft form on March 9 which the Tl Team has assured in writing will be incorporated in the final version) and finds that all material concerns have been adequately addressed and are now closed. apart from one remaining exception that will be described at the end of the SSHAC Process Review section below. Two GMC models were developed for application to Diablo Canyon Power Plant (OCPP) and Palo Verde Nuclear Generating Station (PVNGS). respectively. The exception applies only to the GMC model for DCPP, and is not relevant to the case of PVNGS. 1 Appendix B -PPRP Closure Letter Page B-1 PG&E Letter DCL**r 5-035 Southwestern United States Appendix c Ground Motion Characterization SSHAC Level 3 Page 12 0118 TECHNICAL REPORT -Rev. 2 PPRP Activities in Support of the SWUS GMC Review In a SSHAC Level 3 study, the PPRP fulfills two roles. The first is that of technical review. in which the Panel ensures that the full range of data, models and methods are considered and that technical decisions and judgments are adequately justified and documented. The second is that of process review, under which the Panel ensures that the study maintains conformity with the SSHAC Level 3 guidelines. To fulfill these roles. the Panel requires adequate opportunities to gain understanding of the data being used, the analyses being performed, the Tl Team's evaluations of data and models, and the technical justifications for the Tl Team's model decisions. The table below summarizes the formal project activities in which the Panel participated. Fulfilling these roles also requires the Panel to provide regular feedback to the Tl Team during the course of the project. Jn addition to verbal feedback during Working Meetings and Workshops, the Panel provided written comments and recommendations at key stages of the project. Those written submittals are also noted in the table. Date PPRP Activitv Clune 21. 2012 Workino Meeting #1 (Planninol AU PPRP members attended. \July 1 B. 2012 Working Meeting #2 (PlaMing) All PPRP members attended. Auaust 27. 2012 Kick-off Meeting. All PPRP members attended. September 17. 2012 P PRP submittal or written oomm en ts on the Project Plan. C>ctobe r B, 2012 Working Meeting #3. PPRP representatives attended as observers. November 3. 2012 PPRP submittal or written comme11ts on revised Project Plan. November 29. 2012 PPRP submittal of PPRP endorsement letter ror Proiecl Plan. December 10, 2012 Workino Meetina #4. PPRP reoresenta1ives attended as observers. February 11, 2013 Working Meeting #5. PPRP representatives attended as observers. March 19-21, 2013 Workshop #1: Critical issues and Data Needs. All PP RP members attended as observers. The PP RP provided verbal feedback to lhe Tr Team a11he end of each da v of the Wori<shoo Amil 12, 2013 Working Meeting #6. PPR P representatives attended as observers. Amil 21, 2013 PPRP submittal of written comments on Workshop #1. Mav23, 2013 Norkina Meelin!l #7. PPRP reoresentalives attended as observers. June 24, 2013 Working Meeting #8. PPRP representatives attended as obseIVers. July 18. 2013 Workina Meeting #9. PPRP representatives attender! as observers. Auaust 21, 2013 Workina Meelina #10. PPRP reoresentatives attended as observe1s. Jclober 2, 2013 Workino Meelina PPRP reoresentalives attended as observers. 15, 2013 Working Meeting #12. PPRP representatives attended as obse1Vers October 22-24. 2013 Workshop #2: Proponent Models and Alternative Interpretations. All PPRP members attenae.d as observers. The PPRP proviaed verbal feedbac1< to tile Tl T earn at the end of each day of lhe Workshop. November 26. 2013 Workino Meeting #13. PPRP representatives :ittended as observers 3, 2013 PPRP submittal of written comments on Workshop #12. Januarv 2. 2014 Workina Meelino #14. PPRP reoresentalives attended as obseivers. January 28-29. 2014 Soecial Working Meelino. All PPRP members attendea as ot>servers March 3, 2014 Working Meelino #15. PPRP rep1ese11tatives attended as obseivers. March 10*12. 201-i Workshop #3; Preliminary GMC Models and Hazard Feedback. All PPRP me.mbers attended as participants. The PPRP provided verbal feedback lo the Tl Team at the end of each d;:iy of tile Workshop. March 24, 2014 Norkina Meetinc #16. PPRP reoresenialives attended as ubservers. April 21. 2014 PPRP submittal of written comments on Workshop #3. 2 Appendix 8

• PPRP Closure Letter Page B-2 PG&E Letter DCL*15-035 Southwestern United States Appendix c Ground Motion Characterization SSHAC Level 3 Page 13 of 18 TECHNICAL REPORT-Rev. 2 Mav 14, 2014 PPRP Closure Pre-Briefinll. All PPRP members attendee as oart1ciDants. Uulv 17*18. 2014 PPRP Closure Briefing_ All PPRP members altenaed as participants. December 13, 2014 Subm iltal No. 1 of PPRP written review com men ts on SWUS G MC Report: en ts on swus G MC Report Rev O, Chapters 7. 1 O, 11, 12, 13, and f!l.ppendices L. M, N, and R. December 16, 2014 rTe!econference, PPRP and Tl Team, to discuss the PPRP written review Submittal No. 1. Januaiy 5, 2015 Submittal No. 2 or PPRP written review commenls on swus GMC Report on SWUS GMC Report Rev.O, Cnapters 6. 8, 9, 14, and Appendices H, I, J, K. 0, andO Uanuaiy 7. 2015 rTeleconference, PPR? and Tl Team. to discuss the PPRP written review Submittal No 2. Uanuary 26, 2015 rTeh:!conference, PPRP and Tl Team, to drscuss the main mudifications introduced in SWUS GMC Report Draft Rev.1. February 9. 2015 rTeleconference, PPRP and Tl Team, to discuss observations from PPRP partial review of SWUS G MC Report Draft Rev 1. F"ebruary 16. 2015 [Teleconference, PPRP and Pmject Manager to discuss project completion ;;chedule. F"ebruary 20, 2015 No. 3 or PPRP written revie.w comments on SWUS GMC Report. Comments 011 SWuS GMC Reoort Draft Rev.1. February 24, 2015 Submittal of Closure Letter based on Draft Rev. t The PPRP finds that the level of ongoing review it was able to undertake. and the opportunities afforded the PPRP to provide feedback to the Tl Team, met the expectations for a SSHAC level 3 study. Interactions with the Tl Team provided ample opportunity for the Panel to gain an understanding of the technical bases for the Tl Team's evaluations. The Panel also was given adequate opportunity to query the Tt Team, especially in Workshop #3 and in the Pre-Closure Briefing and Closure Briefing, to assess the justification provided for their model decisions. The Tl Team provided written responses to each formal PPRP submittal, and in nearly every case the PPRP and Tl Team subsequently discussed the comments and replies in a conference call or Working Meeting. SSHAC Process Review NUREG-2117 describes the goal of a SSHAC process as being "to carry out properly and document completely the activities of evaluation and integration, defined as: Evaluation: The consideration of the complete set of data. models and methods proposed by the larger technical community that are relevant lo the hazard analysis. I nteqra lion: Representing the center. body, and range of technically defensible interpretations in light of the evaluation process (i.e., informed by the assessment of existing data, models, and methods}." During the Evaluation activities, the Tl Team considered new data, models and methods that have been introduced within the technical community since the previous seismic hazard studies were conducted for nuclear power plants in California and Arizona. The 3 Appendix B -PPRP Closure Letter Page B-3 PG&E Letler DCL-15-035 Southwestern United States Appendix c Ground Motion Characterization SSHAC Level 3 Page 14 01 18 TECHNICAL REPORT-Rev. 2 Team evaluated newly available ground motion databases, ground motion prediction equations (GMPEs), and ground motion simulation techniques. Notably, the Tl Team evaluated methods for the representation of non-Gaussian aleatory variability, as well as newly available methods for the visualization and characterization of epistemic uncertainty in ground motion prediction. The PPRP finds that the Tl Team's evaluation and the documentation thereof are consistent with the expectations for a SSHAC Level 3 study, apart from the specific reservation noted at the end of this section. The Integration phase entails thoroughly documenting the technical bases for all elements of the GMC model, to provide assurance that the center, body and range of technically defensible interpretations have been captured. The Tl Team used a new statistlcal technique to generate a suite ot representative models for median ground motion prediction that collectively represent the epistemic uncertainty in ground motion more broadly than do the published GMPEs alone. This technique is combined with a new method to select and weight the predictions of the expanded suite of models. The Tl Team's method for assigning weights is based on consideration of appropriate data sets and numerical simulations, with adequate justification. The Tl Team's model for aleatory variability and weighting of alternative aleatory models is also adequately justified, The PPRP finds that the Tl Team's GMC model integration and the documentation thereof are consistent with the expectations of a SSHAC level 3 project. apart from the specific reservation noted in the next paragraph. The Panel finds that the Tl Team's evaluation of directivity models has limitations. The Tl Team make use of a simplified directivity model to save computational time, and the final report adequately describes that model, how it is used, and some of its limitations. However, because the simplified model is unpublished, it is also necessary for the Tl Team to document that the simplified model is appropriate for the purpose ror which it is applied, in the sense that it gives results that are essentially consistent with the published and peer-reviewed model that it is intended to approximate. The final report (in the March 9 addendum) documents the performance of the simplified model through comparison with results from a hazard calculation that uses the full, publlshed directivity model. At hazard levels of 10*4 and above, the fuU model calculation confirms the conclusion obtained using the simplified model. At hazard levels below 1 o-4* however, the difference in calculated hazard between the full model and the simplified model increases with decreasing hazard level. This increasing trend has not been satisfactorily explained, has not been explored beyond the single fault case provided in the March 9 addendum. and has not been quantified in terms of impact on equal-hazard spectra at hazard levels of 10-5 and lower. Because the key rationale for the zero weighting of the directivity branch in the GMC model for periods longer than 0.5 s (the period range where the directivity effect applies) is the weak sensitivity of hazard to the directivity effect calculated using the simplified model, the PPRP finds that this weighting lacks sufficient technical justification. 4 Appendix B -PPRP Closure letter Page B-4 PG&E Letler DCL-15-035 Southwestern United States Appendix c Ground Motion Characterization SSHAC Level 3 Page 15 or1a TECHNICAL REPORT -Rev. 2 SSHAC Technical Review NUREG*2117 describes the PPRP's technical review role as follows: *'The PPRP fulfills two parallel roles, the first being technical review. This means that the PPRP is charged with ensuring that the full range of data. models, and methods have been duly considered in the assessment and also that all technical decisions are adequately justified and documented. The responsibility of the PPRP is to provide clear and timely feedback to the Tl/TFI and project manager to ensure that any technical or process deficiencies are identified at the earliest possible stage so that they can be corrected. More commonly, the PPRP provides its perspectives and advice regarding the manner in which ongoing activities can be improved or carried out more effectively. In terms of technical review, a key responsibility of the PPRP is to highlight any data. models or proponents that have not been considered. Beyond completeness, it is not within the remit of the PPRP to judge the weighting of the logic-trees in detail but rather to judge the justification provided for the models included or excluded, and for the weights applied to the logic-tree branches." As summarized in the table above, the PPRP reviewed the Tl Team's evaluations of data, models and methods on multiple occasions, and through various means, including written communications, in-person meetings, teleconferences, and review of the project report. The Panel was given adequate opportunity to question the Tl Team concerning details of their analysis, and provided feedback verbally and in writing. The Tl Team was responsive to the technical input from the Panel. The Tl Team's responses included evaluating additional data sets suggested by the Panel, undertaking additional analyses to address specific Panel technical questions or concerns, and examining and assessing alternative technical approaches suggested by the Panel. The PPRP therefore concludes that it has been afforded an adequate basis for technical assessment of the Tl Team's evaluations and model integration. As noted above in the final paragraph of the SSHAC Process Review section, the evaluation of directivity effects has been inadequate and may constitute a technical limitation of the study. Apart from that reservation, the PPRP finds that the project meets technical expectations for a SSHAC Level 3 study. Conclusion On the basis of its review of the SWUS GMC project, the PPRP finds that the project meets, with respect to both process and technical standards, the expectations for a Appendix B -PPRP Closure Letter 5 Page B*S PG&E Letter DCL-15-035 Southwestern United States Appendix c Ground Motion Characterization SSHAC Level 3 Page 16 0118 TECHNICAL REPORT-Rev. 2 SSHAC Level 3 study, with the reservation cited above. That reservation pertains specifically to application of the directivity component of the GMC model to the DCPP site. Sincerely, Steven M. Day Chair, PPRP Brian Chiou Member. PPRP Appendix B -PPRP Closure letter Kenneth W. Campbell Member. PPRP .*1 r') (--...., i , )' ,/,/ ';. J'....' -{7 / c: ,.,_:ii:'"(__ ,r:_ l , .* , ,!'.) * . -::/ Thomas K. Rockwell Member. PPRP 6 Page B-6 PG&E Leller DCL-15-035 Southwestern United States Appendix c Ground Motion Characterization SSH AC Level 3 Page 17 of 18 TECHNICAL REPORT -Rev. 2 Tl TEAM -PM RESPONSE TO PPRP CLOSURE LETTER The PPRP letter identifies a limitation of the study due to the use of the Watson-lamprey directivity model for the sensitivity studies that supported the Tl Team judgment that directivity had only a small effect on the low-frequency ground-motion hazard at DCPP. The Watson-Lamprey model provides a simplified method to include the directivity in the CY14 model in a more efficient manner by randomizing over the hypocenter locations and developing site-specific adjustments to the median and standard deviation of the ground motion for the common-form models. The limitation is related to the differences in the computed hazard if the directivity model from CY14 is applied directly into the hazard rather than using the Watson-Lamprey implementation of the CY14 directivity scaling. This limitation does not apply to PVNGS as there are no faults within 40 km of the site in the PVNGS SSC. The directivity model of CY14 reduces the directivity effects to zero for distances greater than 40 km. so there would be no directivity effects if the CY14 model was applied directly to the hazard calculations for the PVNGS site. For DCPP, the differences between the directivity effects computed using the CY14 model directly and using the Watson-Lamprey model are discussed in Section 6.S of this report. Including directivity for randomized hypocenter locations leads to additional variability of the low-frequency ground motion. This variability is combined with the total standard deviation. The key issue is if the standard deviation, developed from residuals from GMPEs that generally do not include directivity as a predictive parameter, should be reduced to account for the expected improved fit to the data if directivity parameters are included in the model. That is, should the additional aleatory variability be added to the standard deviation from the GMPEs or should it be added to a reduced standard deviation model that accounts for an improved fit if directivity parameters are included in the GMPE rnodeL The Watson-Lamprey model assumes that the standard deviations from the published GMPEs include the effects of variability due to directivity, and therefore, applies a reduction to standard deviation before adding the directivity effect on the standard deviation. If this reduction is not applied, then there will be an increase in the total standard deviation which leads to an increase in the hazard at low hazard levels_ Section 6.5 shows examples of the effect on the hazard for these two alternatives. Developing a directivity model that is consistent with the median and standard deviation of the GMPEs remains an area of research. The directivity sensitivity studies in this report that used the Watson-Lamprey model were for a period of 2 seconds. At this period, the reduction to the standard deviation in the Watson-Lamprey model is zero. Therefore, the conclusions from the hazard sensitivity for directivity are not affected by the approach of using a reduction to the standard deviation before adding the directivity effects. This Appendix B -PPRP Closure Letter Page B-7 PG&E Letter DCL-15-035 Southwestern United States Appendil( c Ground Motion Characterization SSHAC Level 3 Page 18 of 18 TECHNICAL REPORT -Rev. 2 remains an issue for periods longer than 3 seconds, but the Watson-lamprey model is not applied in the final GMC model. At a period of 3 seconds, using either approach leads to a small effect on the hazard at the lE-4 hazard level as shown in Section 6.5. The directivity effect is primarily a standard deviation effect. If the directivity effect is applied to the full standard deviation (without reduction}, then there is a potential increase of 2% to 8% for the ground motion at the lE-4 to lE-6 hazard level for T ::;; 3 seconds. This increase reflects the effect of the increased standard deviation. The range of total standard deviation models developed in Chapter 13 of this report for a period of T = 2 seconds leads to a broad range (15% to 25%} for lE-4 to lE-6, as shown in the hazard sensitivity results in Section 14. The same range of epistemic uncertainty will apply for T = 3 seconds. The Tl Team agrees that implementation of directivity into ground-motion models needs further research and that there is uncertainty in the effect of directivity on the total standard deviation, but, given that the potential range of the directivity effects is well within the range captured by the epistemic uncertainty in the total sigma logic tree, the Tl Team judges that total sigma logic tree adequately captures the potential range of the standard deviation including directivity effects. The limitation noted by the PPRP does not significantly affect the range of the standard deviation of the ground-motion model for application to DCPP. Appendix 8 -PPRP Closure letter Page B-8 Regulatory Commitments Enclosure 2 PG&E Letter DCL-15-035 PG&E is making the following regulatory commitment in this submittal: Commitment Due Date PG&E will submit the resolution of the PPRP identified To be determined request as soon as it is completed. In this submittal, Pacific Gas and Electric Company (PG&E) is revising the regulatory commitment made in PG&E Letter DCL-13-044, "Response to NRC Request for Information Pursuant to 10 CFR 50.54(f) Regarding the Seismic Aspects of Recommendation 2.1 of the Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accident," dated April 29, 2013. PG&E committed to follow the guidance provided in NEI letter, "Proposed Path Forward for NTTF Recommendation 2.1: Seismic Reevaluations," dated April 9, 2013, with two clarifications. The guidance provided in the NEI letter was to utilize the Electric Power Research Institute Report No. 1025287, "Seismic Evaluation Guidance: Screening, Prioritization, and Implementation Details (SPID) for the Resolution of Fukushima Near-Term Task Force Recommendation 2.1: Seismic," dated November 2012 for the performance of the seismic reevaluations. This commitment indicated that PG&E will perform the ground motion response spectrum comparison. PG&E's interim evaluation in preparation for the seismic probabilistic risk assessment (SPRA), as described in Enclosure 1, provides reasonable assurance that it is safe to operate DCPP while the updated/upgraded SPRA is being developed. As a result, performance of an expedited seismic evaluation process is not necessary.

Focus Area Ouestions!T opics for DCPP Public Meeting 4128 In addition to providing a general overview of the SSC and GMC SSHAC Reports and March 2015 50.54(f) response for DCPP, please provide additional clarification on the following topics. Seismic Source Characterization 1. Summarize the key data used to constrain the slip rate of the Hosgri fault, including associated uncertainties. 2. Clarify how elements of the thrust/reverse interpretation for the San Luis Range Thrust are incorporated into the SSC. 3. Clarify how the rupture models are derived from the fault source geometry models. 4. Summarize the methodology used to define the equivalent Poisson rates. Ground Motion Characterization 1. Provide additional detail on the criteria used for the selection of the candidate ground motion prediction equations (GMPEs) for development of the common form median ground motion models for DCPP. Specifically, please elaborate on the basis for including GMPEs based on datasets other than NGA-West2. 2. Provide additional detail on development of the common functional form used to fit the candidate GMPEs. Specifically, please discuss how model parameters such as depth to Vs=1 kmls and 2.5 km/s (which are present in some of the candidate GMPEs) are accounted for in the functional form. 3. Provide additional detail on the approach for weighting the selected common form models as well as the criteria used to verify the physicality of the final models. 4. Provide additional detail on how the continuous distribution for total sigma (ass) was developed by combining the between-event and within-event aleatory variabilities. Site Response 1. Section 2.3.2.1 of the 50.54(f) submittal states that shear modulus and damping curves are not directly applicable to DCPP since analytical modeling is not used and that linear site effects are implicitly included in the empirical GMPEs for Vs30=760 mis. However, the NGA-West2 database has a limited amount of data for sites with Vs30 near 760 mis and for earthquakes with magnitudes and source-to-site distances similar to those dominating the hazard for DCPP. Please provide additional information on how these limitations in the NGA-West2 database are accounted for in the site response model for DCPP. 2. Section 2.3.6 of the 50.54(f) submittal describes the development of the site term for DCPP. For the calculations of between-event residuals, provide additional information on the criteria used to determine the appropriate distance range(+ and -Rrup) to the sample station. Please discuss the sensitivity of this distance range on between-event residual values. Please provide an example calculation that uses site-specific values to determine the values for including the epistemic uncertainty in the source term. 3.0 I Diablo Canyon I 2.5 n GMRS I -!*ODE -*1 2.0 ]I I HE .2 -j1 I --L TSP 84°/oile '+-' ... *J1 I ---LTSPx1.35 Qi 1 5 *1 '-' . iH , *-.,. 11 SLB Ergo (,J .,. *II I , , 11 SLB SStn C'CS ' J:; .j1 I 14 Sh+HE+SS (,J (1) 1.0 a. "' 0.5 **n------, I I I I . -I --< * , ....

• I .. a -----,/'" , j" :7'*/* ,,_/ ,.;: "---o.o lL . 0.1 1.0 10.0 100.0 Frequency (Hz)

LICENSEE: FACILITY:

SUBJECT:

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, O.C. 20555-0001 May 27. 2015 Pacific Gas and Electric Company Diablo Canyon Power Plant. Unit Nos. 1 and 2 SUMMARY OF APRIL 28. 2015. CATEGORY 1 PUBLIC MEETING WITH PACIFIC GAS AND ELECTRIC COMPANY TO DISCUSS DIABLO CANYON POWER PLANT. UNIT NOS. 1AND2 SEISMIC HAZARD REEVALUATION ASSOCIATED WITH IMPLEMENTATION OF JAPAN LESSONS-LEARNED NEAR-TERM TASK FORCE RECOMMENDATION 2.1. SEISMIC On April 28. 20151* the U. S. Nuclear Regulatory Commission (NRC) staff held a Category 1 public meeting with the Pacific Gas and Electric Company (PG&E, the licensee) at NRC Headquarters, Two White Flint North. 11545 Rockville Pike. Rockville. Maryland. The purpose of this meeting was to discuss Diablo Canyon Power Plant. Unit Nos. 1 and 2 (Diablo Canyon) Seismic Hazard Reevaluation2 associated with the implementation of Near-Term Task Force ( NTTF) Recommendation 2. 1: Seismic of the March 12. 2012. N RC request for information issued pursuant to Title 10 to the Code of Federal Regulations Part 50, Section 50.54(f) (hereafter referred to as the 50.54(f) letter)3. During the meeting. the NRC staff provided an overview of NTTF Recommendation 2.1 "Seismic" including specifics of the review process as it relates to the Western United States (WUS) sites4 Additionally. PG&E representatives provided an overview of Diablo Canyon's seismic hazard reevaluation which included specific discussions of several focus areas identified by the staff and conveyed to PG&E before the public meeting!>. NRC staff and PG&E representatives* discussions included the following meeting highlights:

• NRC staff presented an overview of NTTF Recommendation 2.1 "Seismic" review process which included specifics on how the process would be applied to the review of the WUS submittals.
• NRC staff provided the overall schedules for Recommendation 2. 1 seismic hazard and risk evaluation activities. The staff stated that the screening and prioritization results letter for the WUS reviews would be issued by mid May 2015. Specifically. for Diablo Canyon. the plant has screened-in for further risk evaluation as a higher priority group. Subsequently. by letter dated May 13, 20156, NRC placed Diablo Canyon into the 1 The meeting notice is available via the Agencyw1de Documents Access and Management System (ADAMS) under Access:on No ML 151C5A528 ,. Diab10 Canyon's Seismic Hazard Reevaluation is available via ADAMS under Accession No. ML 1507CA6C7 3 The 50 54(f) letter and Enciosure 1 are available under ADAMS Accession Nos. ML12C53A34C and ML 12056A047, respectively.
• NRC's slide presentat!on ;s available via ADAMS under Accession No ML15117A226 ' PG&Es slide presentation rs available via ADAMS under Accession No. ML151 17 A069 *The screening and prioritization resuits for the WUS sites can be found via ADAMS under Access1on No ML 151136344 highest priority group (Group 1) for the reevaluated seismic hazard review along with 11 other reactor sites.
• The staff described the main differences between the Central and Eastern United States (CEUS) and WUS submittals. The staff emphasized the complexity of the WUS reviews and explained the reasons for anticipating that the WUS reviews may take longer to be completed than those for the CEUS.
• PG&E provided an overview of their seismic hazard reevaluation. Specifically, PG&E responded to a series of potential issues or focus areas that the staff had identified and conveyed to PG&E before the meeting7. These discussions helped the staff better understand PG&E approaches and added clarity to assist in the staff's review.
• PG&E provided additional clarification on Diablo Canyon's seismic design and licensing basis. Specifically, PG&E described their Long-Term Seismic Program margin assessment in order to demonstrate additional seismic margin and ensure plant safety while the updated risk evaluations are in progress.
• PG&E stated that they are moving forward with the seismic probabilistic risk assessment update and are currently coordinating with the Electric Power Research Institute to be one of the first licensees to complete these evaluations.
• The staff asked for clarifications in areas of the seismic reevaluation report where information appeared to be in conflict or incomplete.
• The staff indicated its plan to request from PG&E free field recordings for the Parkfield and San Simeon earthquakes used to develop the ground motion model. PG&E indicated that it will work with the staff to supplement the report with this information. Requests for additional information by the staff are also expected.
• The staff is currently evaluating PG&E's intentions not to perform the Expedited Seismic Evaluation Process and will provide a formal response. No regulatory decisions or commitments were made during the meeting. The public was invited to observe the meeting and was given an opportunity to communicate with the NRC during the public meeting before adjourning. The NRC staff received several public comments, which were addressed during the meeting and no meeting feedback forms were received. The staff received a comment from Dr. Gene Nelson (Physical Sciences professor at Cuesta College and Government Liaison for Californians for Green Nuclear Power) via email during the meeting. The NRC staff inadvertently missed the opportunity to acknowledge Dr. Nelson's comment during the meeting. According to Dr. Nelson, Diablo Canyon has favorable site conditions, which attenuate or dissipate earthquake energy over relatively short distances. Due to these favorable conditions, the primary earthquake forces seen by the plant would be dominated by nearby earthquake sources and energy transmitted to the plant would be 7 NRC Technical Focus Areas for Support of Public Meeting on April 28 can be found via ADAMS under Accession No. ML 151138360 dominated by the small section of the earthquake rupture closest to the plant. Dr. Nelson stated that when considering the information presented at the meeting of overall plant ruggedness and the seismic hazard insights discussed above, Diablo Canyon will continue to operate safely -with generous safety margins -during anticipated earthquakes. The staff received a comment via email from Rochelle Becker (Alliance for Nuclear Responsibility) after the meeting on May 12, 20158. Mrs. Becker summarized several concerns identified by the California Public Utilities Commission's Independent Peer Review Panel (IPRP) and emphasized the need for the staff to consider this information as part of its review process. The IPRP has expressed concerns regarding the modeling assumption used by PG&E to characterize soil conditions beneath the plant. In response to the comment, the staff stated that it is aware and following the IPRP activities and will consider this information as part of its review of the Diablo Canyon Seismic Hazard Screening Report supporting NTTF Recommendation 2. 1: Seismic. Rochelle Becker's (Alliance for Nuclear Responsibility) wrihen concerns can be found via ADAMS under Accession No. ML 15134A25B Please direct any inquiries to me at 301-415-1115 or by e*mail at Nicholas.DiFrancesco@nrc.gov. Docket Nos. 50-275 and 50*323

Enclosure:

List of Attendees cc w/encl: Distribution via Listserv Nicholas J. Difran sea, Senior Project Manager Hazards Management Branch Japan Lessons*Learned Division Office of Nuclear Reactor Regulation List of Attendees U.S. Nuclear Regulatory Commission Public Meeting with Pacific Gas and Electric Company to discuss Diablo Canyon's seismic hazard reevaluation associated with implementation of Japan Lessons-Learned Near-Term Task Force Recommendation 2.1. Seismic April 28. 2015 Name Lisa Walsh Clifford Muns , Diane Jackso on n ----* ! Scott Stoval ancesco Jon Ake Nicholas DiFr Mohamed Sh Vladimir Grai Frankie Vega ams zer ----Toledo . Meralis Plaza Thomas Weaver David Heeszel ---Alice Stieve ----i Nilesh Chokshi -NRC/N NRC/N

• RO RO NAC/N RO _____ 1 NAC/A NRC/R NRC/N NRC/N ... NRC/N ES ES RR RA RO AR RO --NRC/N --. NRC/N NRC/AES .NRC/NRO NAC/NAO NRC/NAO Mike Tschiltz NEI I--1---------1 (continues to next Abbreviations: NEI -Nuclear Energy Institute NMSS -Nuclear Material Safety and Safeguards NAO -Office of New Reactors NRA -Office of Nuclear Reactor Regulation RES -Off ice of Nuclear Regulatory Research Enclosure -------Name i Steve Wyman Richard Rivera-Lugo Siva P. Lingam -1 Organization NRC/NRA NRC/NRO ------NRC/NRA ------Meraj Rahimi NAC/NMSS Mike Markley NRC/NRR Tom Hipschman . NRC/RIV Ryan Alexander NRC/RIV ------Wayne Walker
• NRC/RIV Tom Farnholtz NRC/RIV ---* --------Farhanf Ostadan Bechtel 1 Dennis Damon NRC/NMSS -------* Damon Maslen Friends of the Earth --I---------Norm Abrahamson___ ar Jahangir . PG&E ----*1 ------rl Strick_land --* t PG&E m Jones PG&E ------

Ml15125A186 OFFICE NR R/JLD/JHMB/PM NAME 1 FVega --* DATE 05/15/15 -OFFICE NRR/JLD/JHMB/BC IRA/ Nicholas J. DiFrancesco, Senior Project Manager Hazards Management Branch Japan Lessons*Learned Division Office of Nuclear Reactor Regulation WWalker. A*IV Difrancesco. NRA KManoly, NRA LYong. NRA FVega, NAO MShams. NRA MMarkely. NRA RidsNrrPMDiabloCanyon RidsNrrLASLent ---*-**

• Slent 05i05/15 -....._ ---OGC (NLO) --Rids Rg n 1 Mai I Centc r RidsRgn2MailCenter RidsRgn3MailCenter RidsRgn4MailCentor RidsNrrDorl RidsOpaMail RidsNroDsea RidsNrrDe *concurrence via e-mail =::&O/OSEA/AGSIBC DJackson .. ---*** 05/19/15 I NRR/JLD/PMB/PM ---*-------NAME MShams BHarris NDiF rancesco -*----DATE 05/27115 05120/15 05/27/15 l'rotecting l>eople and the r:uvirou1ncnt Near-term Task Force Recommendation 2.1 Seismic Hazard Evaluation Pacific Gas & Electric Company Public Meeting

\-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent References and Logistics

• Licensee Presentation Slides -ML 15105A528
• NRC Presentation Slides -ML 15XXXX
• Public Meeting Agenda -ML 15XXX
• Licensee Hazard Report -ML 15070A607 and ML 15070A608
• Meeting Feedback Form (request from njd2@nrc.gov)
• Webcast Archive at http://video.nrc.gov
• Meeting Summary to be issued within 30-day 2

\-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent Meeting Purposes

• Gather additional information based on early identification of areas where additional technical information will support the staff's review
• Gain a better understanding of how the licensee conducted their evaluation 3

\-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent Outline

• Background of NRC Near-term Task Force Recommendation 2.1 (NTTF R2.1)
• Current NRC approach to seismic hazard characterization
• Hazard characterization for NTTF R2.1
• Potential outcomes
• Focus questions for NRC review
• Timeline 4 U.S.NRC J 1*srrm .. ..-.n:s SlU.t:AR RF.<a:O.ATOR\" Proleclitig People and the Enviroti>>umt NTTF Report and Recommendations Recommendation 2 The Task Force recommends that the NRC require licensees to reevaluate and upgrade as necessary the design-basis seismic and flooding protection of SS Cs for each operating reactor. The Task Force recommends that the Commi:,:.ion direct the actions to ew,ure aclequate protec:ion fro1r natural phenvnena. con:,i:,tent w1tl1 t*1e curre'lt :.tate of and analyt"cal met*wds. These should be cmdertaken to prevent fuel darnage and to en:,ure con:a1nrnent and :.pent fuel pool integrity: 2.1 Order licensees to reevaluate the seismic and flooding hazards at their sites against current NRG requirements and guidance, and if necessary, update the design basis and SSCs important to safety to protect against the updated hazards. 2.2 Initiate rulemaking to require licensees to confirm seismic hazards and flooding hazards every 10 years and address any new and significant information. If necessary, update the design basis for SSCs important to safety to protect against the updated hazards. 2.3 Order licensees to perform seismic and flood protection walkdowns to identify and address plant-specific vulnerabilities and verify the adequacy of monitoring and maintenance for protection features such as watertight barriers and seals in the interim period until longer term actions are completed to update the design basis for external events. RECOMMENDATIONS FOR ENHANCING REACTOR SAFETY INmE215TCENTU RY 5

\-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent N RC 50.54{f) activities to address NTTF Seismic Recommendations UMITED STATES NUCLEAR RFGULATORY COMMISSION ..:." _ '-t'ns..ees .a11d H*:..1ct:r"$ llf Pt:t*r* Is 1r ;..;. ..... cere1*ed f'fa:..,1JrrfGto-., ac roP. PL;r-ISUO.NI f(; lll_L 10 :.:* 1Hf::. L.:-:;(.>} (J' .f*t !.If i?AJ .1.'l)l\IS 5.i1:4' NG R[f:C"IM,.tft-.DA TIOt\.S; 1 l 3 Al'.(i 9 '* ()F T>--E '-F.Aq.r::ll*.1 RE"JlE".'Y ci: FRG-V THf::. [)AHCHI .. CC [;E"-1 T ... s *!So tr.m;;i '"" ""1r-.. r,( 1(; 1

• c. at the E:ns-r;;i :..:r of r<:;54 .n 3m¥idltll
• 3!"'*::J 1*+ t.. S a1i:ir:f :,-*::;.:>1'1n-::i.:i.1;:w;* **Tire 10 c:f t'le r:.' f;*1:'.J* ... 11( CTR. PJtC 5C P ** ... ;.:f1J*.*<;11Jn5 '- r;r 0'1 ..-(' t.:-: r.-::--... tn f;JX..,,. thf:' *"e1:1on rec.crrTl(""'r:at10'1\ *er :he t.Jear. r 9'"1l t as.1o .. f\ I If' :* re*, <l?w .,),.;:;. . Jr tl'\P F 1..kudun:.l Oa1 u;t11 ".*::luat ':tc ".'J T"it! ,.,,11 t!n;ihlr. :hr. w-r.!hAr rrv r:ur.lr.ear .... .;::<"-*,*::> ... ' '0$.,Y;n;o; tr. T10d1f ro susc-?rall!ld *Jf *evo .. ... or (Ci"[*"'<IM :GOL.1 *::ic>R Pa"! In NTTF 7 :t:;; J 't"\l.,.dlll!J -:.e1:s*111;. <11rtLJ 'l;,:.it.: ".g 1eev.Jh.J.,l:ut*, -'f*IJ dl'f"! y ... ... n1711 r*1 ll'I0*1SJ'es. :.t t:. y 1nf;-.r-n.)!1on .. 3 t:fll.! *l .lrl! n:t ..::r :)": Pt!'11ls 10 Pa1T s.:J 0S:t'!l:O:.I .. 9 ;>:Tlmt .;""t:S\"'" 1{) C*R Pr. 5C b nr , .. ,. .. .,n r{"*: .. ar.::;*rienl iii 1.,t:: 0<t' n * .t:;le'9t -.;<:'\\'f:* .. "!inijl 'flll11 l'IC r.I ., 11. 201 ,
• C*<!>at T -1Clo.u ... a,..e 3nd t-.e-..., RC 1&.'"*to I\ TTf C *e.:t 1 P l.lf*le>Z :!t -'::tf 1 t.asi.:ec t.. Tfr ..,,.. ""-; .:uitJ ur J.r!d :s.,d rf ""ir.**c)' should n<<L"-e .Jdd1I ::*,a i1 .. ,)11 Tlioff?I*; ;t ::-' *'1 *t 'lr. .:a.Ji:-t-:: J., ,. l2 2*: !;[ ;::'* 0 0 *CCq'.'l :..i.genr ,-\\o1c1e On.-.,, ... Ac:r.,..$'\ 01n:j No Ml ;1 OC<°.$in:-1 ::OJ.U :uound :n@ **ri*dnpt .. cc:nc,.=*" ,.. "i'dl nt rirfnn!'l.t' .., 1.t10."'1e***, l.Jlt'vt't'lt ....... , i11: 1Ja:1::i1' C.*1:J *. ., f:;* *h t ,,.. .. .;a'r.1'1 f . .r.:;t r:.n I!""! <1nrt :tit! p101*'! :..:>pao1I !n=s. rtie N f a'".: rre 1-: ii., :..: ful\ .. :s 'o <.;c;i:_r ,,., mt-iU 1 r'"1e "P.C *t-(ft ::{1ne "l1r:1i pl.:t"*t and <;* a-:u .... '3*ct '\Cl .a .. lr'!'T11., .. nt 'i' tn f1ulil i; *ri d11CI 50.54(f) Request for Information Letter issued March 12, 2012 * *
• Enclosure 1 (or R2.1): Seismic hazard and risk reevaluation Enclosure 3 (or R2.3)
• Seismic Walkdowns Other enclosures addressed flooding and emergency response 6

\-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent Tiered-approach to Seismic Activities NTTF 2.3 -Seismic Walkdowns -COMPLETED reviews June 2014 licensees identify and address degraded, nonconforming, or unanalyzed conditions relative to a plant's current licensing and design bases. // NTTF 2.1-Hazard Reevaluations: SUBMITTED CEUS:3/2014; WUS:3/2015 Licensees reevaluate hazard based on present day guidance/methods used to define the design basis for new \-..reactors. \ NTTF 2.1-Interim Evaluation: COMPLETED CEUS: 4/2014; WUS: 4/2015 --, If the design basis does not bound reevaluated hazard: Licensees evaluated the need for interim evaluations using new seismic sources and ground motion with old hazard while the longer-term risk evaluation is '* \ __ perjormed. / ---( \ NTTF 2.1-Interim Expedited Approach {ESEP) CEUS: 12/31/2014; WUS: 1/16 If the design basis does not bound reevaluated hazard: Licensees perform interim evaluation to demonstrate key pieces of equipment for core cooling at a higher hazard using installed FLEX equipment .. up to 2 x SSE. Evaluate need for modifications while longer-term risk evaluation is performed. 1 / NTTF 2.1-Seismic Risk Evaluations: June 2017-2020 -J. If the design basis does not bound reevaluated hazard: Licensees determine perform a seismic risk evaluation. Regulatory Actions NRC staff determines whether additional regulatory actions are necessary to provide additional protection against the updated hazards. 7 \-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent Probabi I istic Approach

• Previous studies such as 2011 Shoreline Fault Report and 2014 Coastal Commission Report were deterministic -Few selected scenario earthquakes -Limited treatment of uncertainty
• NTTF Recommendation 2.1 calls for seismic hazard reevaluations at each nuclear power plant using current NRC regulations
• Current NRC regulations and guidance specify a probabilistic approach for developing design ground motions
• Probabilistic ground motion hazards are characterized by a Ground Motion Response Spectrum or GMRS 8

\-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent Development of Seismic Hazard for R2.1 Reeva I uations

• Licensees perform probabilistic seismic hazard analyses following NRC guidance (Regulatory Guide 1.208) i * -* *** 1. I
• CEUS licensees (96 units/59 sites) ! =** ......... . .,, ... , .. . . '.' , . -Previously approved SSHAC Level 3 Models 1* --*** .. =***** i ...... . -Plant-specific site analyses 1. I
• WUS licensees (6 units/3 sites) . .,:*: ... .. * -Regional source and ground motion models developed by each Licensee using SSHAC Level 3 Studies -Plant-specific site analyses 9

\ -* U.S.NRC Screening Approach for R2.1 Reevaluations

• Screening approach specified in Industry Screening, Prioritization, and Implementation Details (SPID) Guidance
• SPID provides detailed guidance for -Development of GMRS -Seismic Risk Evaluations & Limited Scope Evaluations (high frequency, SFP)
• Plants with GMRS >SSE "Screen In" for -Interim Evaluations (and actions, as needed) -Expedited Interim Evaluations (and actions, as needed) -Seismic Risk Evaluations 10

\-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent Outcome 1 0.1 l lO frequency (Hz) Outcome 2 c 0 --'i"I. (i) O.l ) **:-frequency (Hz) lOC lOC Potential Outcomes for R2.1 Reevaluations No Further Analysis 20 .--------------. Outcome 3 §1.5 c .g -IU -"'* ..... (]) )IJ 0 \ \ I/) ""----00. _____ ___. 0.1 1 -o 1oc frequency (Hz) Industry Testing Program for High Frequency Sensitive components 11 NRC Review of SSHAC -. .. m, ... ,,. ... ..... ro._., Studies for WUS Sites

• Did SSHAC process follow NRC guidance?
• How effective was the peer review panel?
• Have all applicable data been considered?
• Were data uncertainties identified and considered?
• Was an appropriate range of applicable models considered?
• How were models selected and weighted in the analysis?
• How were models assembled into the PSHA? 12

\-* U.S.NRC NRC Review of Source Mode Is for WUS Sites

• How were seismic sources identified? -Geologic mapping -Geophysical observations -Earthquake catalog
• How were seismic sources characterized? -Geometry (location, length, dip) -Range of magnitudes -Faulting style (normal, reverse, strike-slip) -Slip rate and recurrence models -Complex rupture scenarios 13

\-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent NRC Review of Ground Motion Models and Site Response for WUS Sites

• Do final ground motion models capture a reasonable range of alternative models?
• How were sources of uncertainty captured in model development?
• How were ground motion models adjusted for local site geology?
• Does site response analysis cover a reasonable range of alternative soil/rock properties?
• How was uncertainty in site response analysis incorporated into final probabilistic hazard curves? 14

\-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent Hazard Development Expedited Interim Evaluations Risk Evaluations Higher Priority Lower Priority Hazard Analyses Expedited Interim Evaluations 2012 I I Schedule for Seismic Hazard and Risk Evaluations 2013 2014 2015 2016 2017 2018 2019 2020 CEUS '\

• wus '1
• All plants r CEUS I mods
• I 1 wus mods Only plants I with new
• I Group 1 I I Risk Evaluations '1 Staff acknowledgement to use GMRS for risk evaluation seismic hazard exceeding design basis Group 2 Group 3 (as needed) e Staff Assessment or response -15 Forthcoming Seismic Protecli**g People and the Enviromnent Screening Letter
• Issuance of letter for WUS sites in 2 weeks
• Diablo Canyon has screened-in for further risk evaluations and is a review priority
• No immediate safety issues identified
• Information supports safety assurance allowing additional time to complete the seismic risk evaluation 16

\-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent List of Acronyms

• CEUS -Central and Eastern United States
• GMRS-Ground Motion Response Spectrum
• NRC-U.S. Nuclear Regulatory Commission
• NPP -Nuclear Power Plant
• NTTF -Near-Term Task Force
• SFP -Spent Fuel Pool
• SMA-Seismic Margins Analysis
• SPID -Screening, Prioritization, and Implementation Details SPID
• SPRA-Seismic Probabilistic Risk Assessment
• SSC-Structures, Systems and Components
• SSHAC-Senior Seismic Hazard Analysis Committee
• SSE -Safe Shutdown Earthquake
• SPID -Screening, Prioritization, and Implementation Details
• WUS -Western United States 17

\-* U.S.NRC Break for NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent Staff Alignment

• 15 -20 minute planned break for NRC staff alignment to support meeting wrap-up
• Meeting to resume at 4:00pm (Eastern) or 1 :OOpm (Western) 18 Opportunity for Public Protecli**g People and the Enviromnent Questions or Comments
• Additional Questions? Please ask us at: JLD_PublicResource@nrc.gov 19

\-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent Backup Slides 20 Additional WUS Protecli**g People and the Enviromnent Seismic Hazard Reports Public SSHAC Reports

• Diablo Canyon http://www.pge.com/en/safety/systemworks/dcpp/sshac/index.page 21

\ -* u.S.NRC Potential Alternative s I ides 22 \-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent Guidance Documents

• Two main guidance documents proposed by industry and endorsed by the N RC
• Screening, Prioritization, and Implementation Details (SPID) -Submitted by EPRI on November 2012 -Endorsed by NRC on February 15, 2013 -EPRl-1025287 (ML12333A170)
• Seismic Evaluation Guidance: Augmented Approach (aka Expedited Approach) -Submitted by EPRI on April 9, 2013 -Endorsed by NRC on May 7, 2013 -EPRl-3002000704 (ML 13102A 142) 23

\-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent Seismic 2.1 Process Ensures Clarity, Consistency, and Informed Regulatory Decisions PHASE 1 INFORMATION GATHERING STAGE 1 Interact with Industry on Hazard and Risk Evaluation Guidance CELIS Licensees submit Site Response (9/2013 & 3/2014) Screened-in plants complete Expedited Approach Interim (CEUS:12/31 /2014;WUS:1 /2016) and Risk Evaluation (Group 1 : 2017) NRC reviews Risk Evaluation * ,----------------PHASE 2 DECISION-MAKING NRG makes Regulatory Decisions as Needed *Safety Enhancements

• Backfit Analysis
• Modify Plant License ----------------24 Hill, Brittain From:Hill, Brittain Sent:8 Jun 2015 07:12:15 -0400 To:Kock, Andrca;Munson, Clifford Cc:Jackson, Diane;Ake, Jon

Subject:

RE: FYI: News on Diablo I checked the USGS California Seafloor Mapping Project site http://walrus.wr.usgs.gov/mapping/csmp/index.html, and there are no new (i.e., after Sept 2014) data published for the Diablo area. Surveys for this area are "in progress" The high-res data referred to in the news article are the results of previous offshore mapping, which is in the Sept 2014 PG&E Cal Coastal Commission report (on Shoreline Fault). The offshore data were considered in the SSHAC for Diablo, which includes low likelihoods for earthquakes from connected offshore faults. From: Kock, Andrea Sent: Friday, June 05, 2015 5:48 PM To: Munson, Clifford; Hill, Brittain Cc: Jackson, Diane; Ake, Jon

Subject:

FYI: News on Diablo Was this included in Diablo's recent submittal? USGS Publishes Super-High Resolution Seafloor Maps Near Diablo Canyon Plant. The Point Reyes (CA) Light (6/5, Kimmey) reports that the United States Geological Survey has published "extremely high-resolution maps of the seafloors offshore of Tamales Point, Drakes Bay and San Francisco Bay" as part of a "multi-million dollar, decade-long partnership with other agencies to pin down baseline conditions of the seafloor." According to USGS research geologist Samuel Johnson, the maps "provide a very high-resolution starting point from which you can monitor change." Among other discoveries, Mr. Johnson "said the project has found that offshore faults near Diablo Canyon Nuclear Power Plant, in San Luis Obispo, previously thought to be separated by a gap, are in fact connected." Andrea Kock, Deputy Director Division of Site Safety and Environmental Analysis Office of New Reactors United States Nuclear Regulatory Commission Ph. 301-415-2368 UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 The Power Reactor Licensees on the Enclosed List May 13, 2015

SUBJECT:

SCREENING AND PRIORITIZATION RESULTS FOR THE WESTERN UNITED STATES SITES REGARDING INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(f) REGARDING SEISMIC HAZARD RE-EVALUATIONS FOR RECOMMENDATION 2.1 OF THE TERM TASK FORCE REVIEW OF INSIGHTS FROM THE FUKUSHIMA ICHI ACCIDENT The purpose of this letter is to inform Western United States (WUS) licensees of the results of U.S. Nuclear Regulatory Commission's (NRC's) seismic hazard screening and prioritization for plants to conduct seismic risk evaluations. The NRG staff has reviewed licensee interim evaluations which provide a safety basis supporting continued plant operations. This letter also discusses staff review plans including targets for acceptance of the seismic hazard by the end of 2015 and completion of the staff assessment in 12 to 18 months. BACKGROUND On March 12, 2012, the NRG issued a request for information pursuant to Title 10 of the Code of Federal Regulations, Part 50 (10 CFR). Section 50.54(1) (hereafter referred to as the 50.54(1) letter) (Agencywide Documents Access and Management System (ADAMS) Accession No. ML 12053A340). The purpose of that request was to gather information concerning, in part, the seismic hazards at operating reactor sites and to enable the NRC staff to determine whether licenses should be modified, suspended, or revoked. The "Required Response" section of Enclosure 1 indicated that licensees and construction permit holders should provide a Seismic Hazard Evaluation and Screening report within 3 years from the date of the letter for WUS plants (i.e., Columbia Generating Station (Columbia), Diablo Canyon Power Plant (Diablo Canyon), and Palo Verde Nuclear Generating Station (Palo Verde)). Further, the 50.54(f) letter stated that NAC would provide the results of the screening and prioritization indicating deadlines for individual plants to complete seismic risk evaluations to assess the total plant response to the re-evaluated seismic hazard. Additionally, by letter1 dated February 20, 2014, the NRC provided supplemental information on the content of the seismic re-evaluated hazard submittals including guidance on reportability and operability. The purpose of this letter is to inform WUS licensees of the NAC's screening and prioritization and to allow licensees to appropriately plan the completion of further seismic risk evaluations described in Enclosure 1 of the 50.54(f) letter. To respond to the 50.54(f) letter, all addressees committed to follow the Electric Power Research Institute (EPRI) Report, "Seismic Evaluation Guidance: Screening, Prioritization and Implementation Details (SPID) for the Resolution of Fukushima Near-Term Task Force 'The February 20. 2014, supplemental information letter is available in ADAMS under Accession No. ML 14030A046. Recommendation 2.1: Seismic,"2 as supplemented, by the EPRI Report, "Seismic Evaluation Guidance: Augmented Approach for the Resolution of Fukushima Near-Term Task Force (NTTF) Recommendation 2.1: Seismic"3 (this approach is known as the Expedited Approach). The NRC held multiple public meetings and teleconferences with industry and the public leading to the development of the guidance documents to review the re-evaluated seismic hazards. The WUS licensees submitted seismic hazard and screening reports (SHSRs) by letters dated on or before March 12, 2015 (references are provided in Enclosure 3 of this letter). The SHSRs included interim evaluations that the staff has reviewed as part of this letter. The NRC staff conducted the screening and prioritization review of the submittals by assessing each licensee's screening evaluation and hazard analyses utilizing the endorsed SPID guidance. INTERIM EVALUATIONS4 The 50.54(f) letter requested that licensees provide "interim evaluations and actions taken or planned to address the higher seismic hazard relative to the design-basis, as appropriate, prior to completion of the risk evaluation." For those plants where the re-evaluated seismic hazard exceeds the seismic design-basis, licensees stated they will provide interim evaluations to demonstrate that the plant can cope with the higher re-evaluated seismic hazard while the longer-term seismic risk evaluations are ongoing. In support of the requested interim evaluations for licensees, WUS plants provided information related to seismic margin evaluations or insights from Individual Plant Examination of External Events (IPEEE) evaluations including estimated seismic risk. Additionally, the submittals discussed completing plant seismic walkdowns as part of NTTF Recommendation 2.3 in order to verify that the current plant configuration is consistent with the licensing basis. The NRC staff review of WUS reports found that licensees have demonstrated seismic margins supportive of continued plant operation while additional risk evaluations are conducted. The interim evaluation provided in March 2015 is a first step in assessing the plant's capacity to withstand the re-evaluated hazard. In the near-term, by January 2016, licensees will complete an "Expedited Approach" to evaluate and identify reinforcements, if necessary, for certain equipment to ensure a safe shutdown pathway can withstand seismic ground motion that exceeds the safe shutdown earthquake (SSE). For Diablo Canyon and Palo Verde sites, the licensees stated that the Expedited Approach would not provide additional safety benefit for their plants because existing anaylses already demonstrate the ability to withstand the higher seismic ground motion. The NRC staff is continuing to assess the information provided by the licensees to determine if it meets the intent of the Expedited Approach review and will respond under a separate letter. 2 The SPID guidance document is found.in ADAMS under Accession No. ML 12333A 170. The staff endorsement letter for the SPID guidance is found in ADAMS under Accession No. ML 12319A07 4. 3 The Expedited Approach guidance document is found in ADAMS under Accession No. ML13102A142. 4 Enclosure 1 of this letter provides a Glossary of Seismic Evaluations, explaining each of the evaluations that are part of the overall seismic reevaluation. SCREENING PROCESS As described in the 50.54(f) letter and the SPID guidance, the seismic hazard re-evaluations were to be conducted using current analysis methods and guidance. The licensees' responses to the 50.54(f) letter provided seismic hazard re-evaluation results, which were the focus of the NRC staff's initial screening and prioritization review. Although the SSE is commonly referred to as a single number. this number represents a distribution of ground motions that occur over a range of spectral frequencies. This results in a curve of ground acceleration over frequency. The ability of the equipment and structures in the plant to withstand the effects of ground motions is frequency specific. For the purposes of the licensees' analyses and NRC staff's review, the SPID guidance identifies three frequency ranges that are of particular interest: 1-1 O Hertz (Hz), a low frequency range of <2.5 Hz, and a high frequency range of >10 Hz. The different ranges have been identified due to the different types of structures and equipment that may be impacted by ground motions in that range. For example, large components generally are not affected significantly by high frequencies (i.e.,> 10 Hz). The frequency range 1-10 Hz is the focus for this portion of the risk evaluation. as this range has the greatest potential effect on the performance of equipment and structures important to safety. For other frequency ranges, discussed below, limited-scope evaluations will be conducted, when appropriate. In accordance with the SPID and Expedited Approach guidance, the re-evaluated seismic hazard determines if additional seismic risk evaluations are warranted for a plant (i.e., the plant screens in for further evaluation). Specifically, the re-evaluated ground motion response spectra (GMRS) in the 1-10 Hz frequency range is compared to the existing SSE:

• If the re-evaluated GMRS. in the 1-10 Hz range, is less than the plant's existing SSE, then the plant screens out of conducting further seismic risk evaluations.
• If the GMRS, in the 1-10 Hz range, is greater than the existing SSE. then the plant will complete the Expedited Approach (including the Interim Evaluation). Most plants that meet this criterion also screen in to conduct a seismic risk evaluation and have committed to conduct high frequency and spent fuel pool evaluations. In addition. if the GMRS meets the low hazard threshold, which is described in the SPID, and only exceeds the SSE below 2.5 Hz, the licensee will perform a limited evaluation of equipment potentially susceptible to low frequency motions. Similarly. if the GMRS exceeds the SSE only above 10 Hz, then the licensee will perform an evaluation of the equipment or structures susceptible to that specific range of ground motion. Enclosure 2 provides the staff's determination of priority tor plants that screen-in to conduct a seismic risk evaluation, and identification of plants to complete limited-scope evaluations (i.e., spent fuel pool, high frequency, or low frequency).

. 4. CONDITIONAL SCREENING As discussed in public meetings5, the staff anticipated the possibility of not being able to complete the determination for conducting a seismic risk evaluation for some plants in the 30 to 60 day review period under certain circumstances. For example, if a licensee provided a unique submittal or deviated from the SPID guidance, additional time for the review might be needed. In general, WUS submittals contain extensive site specific information including site specific source models and ground-motion models which could affect the final screening decisions. Accordingly, during the NRC screening and prioritization process, the staff identified that for Palo Verde additional time and interactions will be required to better understand the seismic hazard for the plant. As such, the staff determined that Palo Verde "conditionally screens-in" for the purposes of prioritizing and conducting additional evaluations. After interactions have occurred, the staff will make a final screening and prioritization determination and provide a letter to the licensee. If the plant remains screened-in, the final screening letter will affirm the plant priority for further evaluations and establish schedule for an Expedited Approach, if necessary. If the plant screens out, the final screening letter also will determine if Palo Verde needs to complete limited-scope evaluations (i.e .. spent fuel pool, high frequency, or low frequency). PLANT PRIORITIZATION The NRC grouped the "screened-in" plants into three groups6, which (i) reflects the relative priority for conducting a seismic risk evaluation that compares each plant's current capabilities to the re-evaluated seismic hazard, and (ii) accounts for the appropriate allocation of limited staff and available expertise for reviewing and conducting seismic risk evaluations. During the prioritization review, the staff considered each licensee's re-evaluated hazard submittals, plant specific seismic and risk insights. The WUS plants are included in the same groups as CEUS plants for completion of seismic risk evaluations. To prioritize the plants for completing seismic risk evaluations, staff examined certain key parameters such as ( 1) the maximum ratio of the new re-evaluated hazard (G MRS) to the SSE in the 1*1 O Hz range; (2) the maximum ground motion in the 1-1 0 Hz range; and (3) insights from previous seismic risk evaluations. As such, Group 1 plants are generally those that have the highest re-evaluated hazard relative to the original plant seismic design-basis (GMRS to SSE), as well as ground motions in the 1-10 Hz range that are generally higher in absolute magnitude. Based on these criteria. Columbia and Diablo Canyon are prioritized as Group 1 plants. Group 1 plants, including Columbia and Diablo Canyon are expected to conduct a seismic risk evaluation and submit it by June 30, 2017. Although, WUS have a shorter timeframe to develop a seismic risk evaluation relative to CEUS plants, WUS sites have the benefit of updating existing seismic probabilistic risk assessments (SPRAs) to meet current guidance. Group 3 plants have GMRS to SSE ratios that are greater than 1, but the amount of exceedance in the 1-10 Hz range is relatively small, and the maximum ground motion in the 5 Discussion as part of public meetings dated December 4, 2014, February 11, 2015, and March 30, 2015 (ADAMS Accession Nos. ML 14342A901, ML 15104A065 and ML 15111 A031, respectively}. 6 Central and Eastern licensees seismic hazard screening and priority reviews were completed in 2014. 1*10 Hz range is also not high. As described above, Palo Verde has conditionally screened in; based on current information Palo Verde has been assigned to prioritization Group 3. Given the limited level of exceedance of the Group 3 plants including Palo Verde, staff is evaluating the need for licensees to conduct a seismic risk evaluation in order for the staff to complete its regulatory decision making. After further review, the staff will decide which Group 3 plants need to complete a seismic risk evaluation to inform NRC regulatory decision making. Risk evaluations for Group 3 plants are due by December 31, 2020. NEXT STEPS Based on the staff's screening review. the licensee for Columbia should finalize and submit an Expedited Approach report no later than January 31, 2016. The NRC staff is continuing to review the licensee-provided information for Diablo Canyon and Palo Verde related to the Expedited Approach. In accordance with the endorsed guidance, the staff acknowledges that the January 2016 Expedited Approach submittal will focus on plant equipment (i.e. safe shutdown pathway7) evaluations and modifications, as necessary, prior to submitting the plant seismic risk evaluations. The content of limited-scope evaluations or confirmations and their associated schedule milestones remain under development with NRC staff and stakeholders. The NRC staff has conducted a number of public meetings on the implementation details of these evaluations, including the development of alternatives approaches for conducting these evaluations. The staff expects that implementing guidance should be established by summer 2015 and fall 2015 for high frequency and spent fuel pool evaluations, respectively. It is expected that WUS licensees can complete these evaluations in parallel with completion of SPRAs for Group 1 plants by June 2017. This letter transmits the NRC staff's results of the seismic hazard submittals for the purposes of screening and prioritizing the plants. It does not convey the staff's final determination regarding the adequacy of any plant's calculated hazard. As such, the NRC staff will continue its review of the submitted seismic hazard re-evaluations, and may request additional plant-specific information through the summer of 2015. The staff has placed a high priority on this review for the early identification of issues that might adversely affect each licensee's seismic risk evaluations. Interactions with licensees will occur as soon as practical, including NRC staff plans to acknowledge whether seismic hazard curves are suitable for use in SPRA development by the end of 2015. The NRC staff plans to issue a staff assessment on the re-evaluated seismic hazard once each review is completed in approximately 12 to 18 months. 7 Section 3 of the Expedited Approach guidance (ADAMS Accession No. ML 13102A142), provides a process to identify a single seismically robust success path using a subset of installed plant equipment, FLEX equipment and connection points. If you have any questions regarding this letter, please contact Nicholas Difrancesco at 301-415-1115 or via email at Nicholas.Difrancesco@nrc.gov. Sincerely,

Enclosures:

1. Glossary of Evaluations 2. Screening and Prioritization Results 3. List of Licensees' March 2015 Re-evaluated Seismic Hazard Submittals 4. List of Licensees cc w/encls: Listserv Glossary of Evaluations Associated with Near-Term Task Force Recommendation 2.1 Seismic Hazard Re-evaluations Interim Evaluation or Actions -An immediate licensee and NRC review of the re-evaluated hazard to determine whether actions are needed to assure plant safety while further evaluations are ongoing. The staff has completed its review and concluded that, based on the licensees' interim evaluations and actions, Western United States (WUS) plants are safe for continued operations. Interim evaluations and actions are provided in Section 5.0, "Interim Actions," of the licensee submittals. Expedited Approach -A near-term licensee evaluation to be completed by January 31, 2016. for WUS plants whose re-evaluated hazard exceeds the current design-basis for the safe shutdown earthquake (SSE) hazard level. The evaluation looks at the systems and components that can be used to safely shut down a plant under the conditions of a station blackout (i.e., no alternating current power is available) and loss of ultimate heat sink. The expedited approach will either confirm that a plant has sufficient margin to continue with a longer-term evaluation without any modifications, or confirm the need to enhance the seismic capacity to assure they can withstand seismic ground motion that exceeds the safe shutdown earthquake. The Expedited Approach guidance document is found in the Agencywide Documents Access and Management System under Accession No. ML 13102A142. Seismic Risk Evaluation -Longer-term seismic risk evaluation provides the most comprehensive information to make regulatory decisions, such as whether to amend a plant's design or licensing basis or make additional safety enhancements. These evaluations provide information to make risk-informed decisions. The staff will use this information in conjunction with the existing regulatory tools, such as backfit analyses, to decide on further regulatory actions. The longer-term seismic risk evaluations could be either a Seismic Margins Assessment or a Seismic Probabilistic Risk Assessment, depending on the magnitude of the exceedance. Limited-Scope Evaluations -These include i) Spent Fuel Pool Evaluation, ii) High Frequency Evaluation, and iii) Low Frequency Evaluation. Respectively, these evaluations are focused on the following: i) spent fuel pool components and systems capable of draining water inventory to the level of the spent fuel, ii) a review of components susceptible to high frequency accelerations (e.g. electrical relays). and iii) a review of components susceptible to low frequency accelerations (e.g. water storage tanks). Enclosure 1 Near-Term Task Force Review of Insights from the Fukushima Dai-lchi Accident Seismic Risk Evaluations Screening and Prioritization Results for Western United States <WUS) Reactor Sites Seismic Risk Limited-scope Evaluations Screening Expedited Evaluation High Low Spent Fuel Plant Name Result Approach (Prioritization Frequency Frequency Pool Evaluation Group) Evaluation Evaluation Evaluation Columbia Generating Station In x 1 x x Diablo Canyon Power Plant, Unit In x* 1 x x Nos. 1and2 Palo Verde Nuclear Generating Conditional x* 3 x Station, Units 1, 2, and 3 in x

• NRC staff is evaluating whether information provided meets the intent of the Expedited Approach. The staff's conclusions will be provided in a separate letter. Enclosure 2 March 2015 Re-evaluated Seismic Hazard and Screening Reports for Western United States Reactor Sites Licensee Facility Date of letter (ADAMS Accession Nos.) Columbia Generating Station March 12, 2015(Ml15078A243) Diablo Canyon Power Plant, Unit Nos. 1 and 2 March 11, 2015(Ml15071A046) Palo Verde Nuclear Generating Station, Units March 10, 2015, (ML15076A073) and 1, 2, and 3 April 10, 2015(ML15105A076) Enclosure 3 LIST OF APPLICABLE POWER REACTOR LICENSEES Columbia Generating Station Energy Northwest Docket No. 50-397 License No. NPF-21 Mr. Mark E. Reddemann Chief Executive Officer Energy Northwest MD 1023 76 North Power Plant Loop P.O. Box 968 Richland, WA 99352 Diablo Canyon Power Plant Unit Nos. 1 and 2 Pacific Gas & Electric Company Docket Nos. 50-275 and 50-323 License Nos. DPR-80 and DPR-82 Mr. Edward D. Halpin Senior Vice President and Chief Nuclear Officer Pacific Gas and Electric Company P.O. Box 56 Mail Code 104/6 Avila Beach, CA 93424 Palo Verde Nuclear Generating Station. Units 1. 2. and 3 Arizona Public Service Company Docket Nos. STN 50-528, STN 50-529. and STN 50-530 License Nos. NPF-41. NPF-51 and NPF-74 Mr. Randall K. Edington Executive Vice President Nuctear/CNO Arizona Public Service Company P.O. Box 52034, MS 7602 Phoenix. AZ 85072-2034 Enclosure 4

ML 151138344 *via email . QfFICE ____ NRR/JLD/LA NRR/JLOIHMB/BC NRO/DSEA/RGS2/BC ; NRR/DORUD . .NDiFrancesc9 SLent *-____ --r-5Jackson---*--; LLu-nd _-__ DATE : 04/22/15 04/24/15 04/23/15 05105/15 05108115 .OFFICE-* NROJDSEA/D ---. OGC NRRtJLDID ==--__ ..... ----* NAME SFlanders __ fo.1_ (J\j_hle for) 05104115 05/07/15 05/13115 DiFranccsco, Nicholas From:DiFrancesco, Nicholas Sent:8 Apr2015 16:30:17 +0000 To:Munson, Clifford;Dcvlin-Gill, Stcphanic;Akc, Jon;Sticvc, Alice Cc:Heeszel, David;Rivera-Lugo, Richard

Subject:

Additional Palo Verde Documents Folks, I have place the additional Palo Verde documents in shared location. Please let me know if you have access issues. Documents are about 100 mb. The licensee is still compiling the PPRP comments and TIT resolution. S:\Palo Verde R2.1 Seismic Information\ Thanks, Nick Senior Project Manager -Seismic Reevaluation Activities U.S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Japan Lesson Learned Project Division n icho las.difrancesco@nre.gov I Tel: (301} 415-1115 Sent:2 Apr 20 I 5 15 :28 :25 +0000 To: 'Thomas.N. Weber@aps.com' ;Carl.stephenson@aps.com; Vega, Frankie

Subject:

APS -R2. l Seismic Licensing Call (888-817-9392 PC: 7956336) Past Seismic Public Meeting http://www.nrc.gov/reactors/operatinq/ops-experience/japan/japan*meetinq-briefinq.html Tom, 11 am eastern is open. A couple of items for discussion, coordination, and planning today. Thanks, Nick

• Supplemental Letter Planning
• Staff Reference for Additional References
• SSHAC PPRP and TIT Comments and their resolution
• Example
• Example from CEUS SSHAC Appendix I -ssc.com/Report/ Appendixl.html 11) PPRP Comment Response Table
• HID Attachments
• Attachment A: Areal Source Coordinates (electronic attachment)
• Attachment B: Fault Source Coordinates (electronic attachment)
• Attachment C: UCERF3.3 Rupture Sets (electronic attachment)
• Attachment D: ABSMOOTH Output (electronic attachment)
• Attachment E: SWUS GMC Regions for Fault Sources (electronic attachment)
• Public Meeting Tentative May 20 Agenda Outline 1. NRC a. Introduction of Meeting Agenda Structure b. General Background on 50.54(f) and 2.1 Seismic c. Technical discussion on goals and expected outcome d. Intro of seismic hazard PSHA methods and use for licensing of new plants I SSHAC 2. Licensee e. SSHAC effort f. Sources g. GMM h. Interim Actions i. Technical Issues I Discussions

3. Break [to discuss -separate staff discussion] 4. NRC j. Discussion of Interim actions and approach k. Technical wrap-up-next steps I. Public Questions From: Thomas.N.Weber@aps.com [ mailto: Thomas. N.Weber@aps.com] Sent: Wednesday, April 01, 2015 8:51 PM To: Difrancesco, Nicholas

Subject:

Supplemental Information Letter for the Palo Verde Seismic Hazard Reevaluation Report Nick, Are you available to discuss the supplemental information letter we are writing regarding the seismic reevaluation report we submitted on March 10, 2015. I was hoping to talk to you tomorrow (Thursday April 2} at 8:00 am AZ time (which is 11:00 am EDT). Or if more convenient, you can call me in my office at 623-393-5764. TN Weber ... DiFranccsco, Nicholas From:DiFrancesco, Nicholas Sent:4 Jun 2015 13:23:19 +0000 To:Munson, Clifford;Scbcr, Dogan;Jackson, Diane Cc:Seber, Dogan;Hill, Brittain;Stirewalt, Gerry

Subject:

Attached ---Columbia Missing Slides Attachments: missing pages2. pdf Fyi. -----Original Messnge-----i-;rom: Williams, Lisa L. l mai Ito: llwi 11 iams@energv-northwest.com J Sent: Thursday, June 04, 2015 9:22 AM To: Dihancesco, Nicholas

Subject:

RE: Thanks! RE: Question on Columbia Seismic Public Meeting Slides Nick, We found the missing slides. I have updated our sel of slides but now it is over the 5 MB limit for NRC email. The missing slides arc attached lo this email. Thanks. Lisa from: Difrancesco, Nicholas [Nicholas.Difrancesco@nrc.govl Sent: Wednesday, June 03, 2015 2:45 PM To: Williams, Lisa L. Subject Thanks! RE: Question on Columbia Seismic Public Meeling Slides Thanks. I'll have slaff check lhc slides. Also. NRC slides are still draft, however, they will likely be a short intro version from previously public meetings. -Nick -----Original Message-----From: Williams. Lisa L. [ mai Ito: II w illimus @energ v-north west.com l Sent: Wednesday, June 03, 2015 5:41 PM To: Difrancesco. Nicholas

Subject:

RE: Question on Columbia Seismic Public Meeting Slides Nick, l believe it is covered in the GMM section. Lisa Sent from my Verizon Wireless 4G L TE smartphonc --------Original message--------from: "Difrancesco, Nicholas" <Nicholas.Difranccsco@nrc.gov> Date: 06/03/2015 5:15 PM (GMT-05:00) To: "Williams, Lisa L."<ilwilliams@cncrgy-northwcst.com> Cc: 'Rich Rogalski' <richard@richard.rogalski.name>

Subject:

Question on Columbia Seismic Public Meeting Slides Lisa. Received a question from the staff of whether Topic #2 under the Source Characterization will be covered verbally'! Thanks, Nick Seismic Source Characterization, Focus Area 2 2. Summarize the information use to define the areal seismic source zones, including: a. Bases for zone boundaries b. Seismicity rate calculations, smoothing, and how uncertainty was captured as part of logic tree. c. Bases for Mmax distributions Pertains to these sections of the report Section 8.1.4.2 Seismic Source Zones Section 8.1.5 Structure of the SSC Model Logic Trees Section 8.3.2 Source Zone Characteristics for the SSC Model Seismic Source Zones Seismic sources defined by differences in: Seismogenic probability p[S] Maximum magnitude, Mmax Recurrence (spatial variations in rate) Future earthquake characteristics For Hanford SSC Model, two types of source zones: YFTB background zone that represents non-fault sources Given original deposition of CRB and age, provides a unique marker for any post-10 My deformation or significant faulting Accounts for sources not included as fault sources Zones B, C, and D include all types of sources; fault sources are not identified separately Summary of SSC Model Assessments Seismic Source Zones Geometry Nature of source boundaries to future ruptures: leaky Future earthquake characteristics Style of faulting Strike and dip of ruptures Seismogenic thickness Mm ax Presence or absence of fault sources Largest observed earthquakes Recurrence Uniform M earthquake catalogue Corrected for clustering and incompleteness Spatial variation in rates Criteria for Defining Source Zone Boundaries

• Tectonic environments Columbia River Basin Cascades Craton Palouse Blue Mountains Yakima Fold Belt
• Seismogenic thickness
• Presence or absence of YFB faults
• Geophysical evidence for Pasco Gravity Low
• Changes in seismicity m ** .. ._, .... EIMJ ,_, '* / " ** J 1.85 to2 / .... \ *.,_ 2 to 3 ' *,, 3 to 4 ., ****** ; / .. --', 4 to 5 / ,;'(.*.** ..... ) .... Sto 6 6to 7 >: 7 :*-: .. *; l-..' . <'..:. . .". ,**.</ / .. * -... .* "..... -.1 r '-"'"'* . ,_ Idaho c *C ,*. ,-)'if '-. o* Study Area 0 50 100 --Kilometers -Fault Sources Source Zones . ... :;

Future Earthquake Characteristics

• Style of faulting
• Strike and dip of ruptures
• Dimensions of rupture .. .. :J. G' ... Right Late1al All Events (n = 447) left laleral I Normal I I ** 11i.11i11.111.i1l1ii11 I R('lferse R19ht *St< Late111I I . 111 ' . . .. *.* .......... *.*. : . . . '*' : . . . *,* , . '. .:. . . . . . .. . . *.* .;,* . . ,,. . . . . .. ,. . . . . ........ *, ... * : . : '. Raki' l"I *7c :l c:J Source Zones -J .....
• 0 50 --t Hanford Site Boundary 100 Kilometers 1 *e .,, *Sh Source Zone Mmax 0.4"> 0.4 O . 0.3 0.2'."> O . .l 0.1 O.OS 0 Fault Source Mmax Distributions 11 I
• Aht.rnum-R<ittlesn.lke Ill ( olu111hi<1 CJ Clernan Mount<iin D FH'rltllru.rn 8 HP,Wf'll *Hom F,wa
• Rirlge *RAW
• R;at t IP\.r1.1kP
• Butte *Saddle Mount.iin o roppenish Ridge o Ur11t.inum Ridge D W;illul.-i F<1ult *Y<1kinu RidRC *Arlington 0 L.iurel f .iult El llin<1 Butte o M.iupi11 r .iult Source Zones B C D 6.85 6.95 7.05 ' ' 6.65 6.75 6.5 [0.2] 6.75 [0.5] 7.0 [0.2] 7.25 [0.09] 7.5 [0.01] YFTB Source Zone 6.5 [0.3] 6.75 [0.4] 7.0 [0.3]

Smoothing

• Nearest-neighbor analysis to assess spatial homogeneity
• Uncertainty included in logic tree *Spatial Smoothing of values using adaptive kernel ..... , 40 .. , Oregon o Seismicity .....______.! Source Zones 118 * .,.,. Idaho Study Area 0 50 100 *--=*--=---Kilometers 120W
• Source Zone Logic Tree SEISMOGENIC THICKNESS Thin [0.3) Moderate [0.4] Thick [0.3] ss =source specific SOURCE ZONE YFTB Zone B Zone C Zone D Mmax Mag X [wt SS] MagY [wt ss] Mag Z [wt ss] SPATIAL VARIATION Smoothing [wt ss] Uniform [wt SS) SEISMICITV ASSOCIATION WITH FAULT SOURCES Associated with fault sources [0.2] Not associated with fault sources [0.8]

DiFranccsco, Nicholas From:DiFrancesco, Nicholas Sent:5 May 201521:46:19 +0000 To:Lingam, Siva;Singal, Balwant;Watford, Margaret Cc:Markley, Michael;Orf, Tracy

Subject:

Awareness of Forthcoming Issuance of WUS Seismic Screening and Prioritization Letter Attachments:lnfo POP Western US Screening Letter rev6.docx Siva. Balwant, Maggie, For awareness, JLD is moving forward issuance of the WUS Seismic Screening and Prioritization letter targeted for Mav 12for Columbia, Diablo, and Palo Verde. I am planning to communicate the results to licensee management once the letter is signed. Current Letter: Open ADAMS P8 Document (Screening and Prioritization Results for the Western United States Sites Regarding Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Seismic Hazard Re-Evaluations for Recommendation 2. 1 of the NTTF Review) A few highlights for awareness:

• WUS Seismic Hazard Review Progress o Screening & prioritization letter -targeting issuance 5/12/15 o All 3 plants screen in tor sPRA; no immediate safety issues o Columbia & Diablo Canyon -Group 1
• sPRA due 06/30/17 (Seismic Probabilistic Risk Assessment)
• Diablo Canyon -Separate letter on ESEP; LTSP provides safety basis
• Public Meetings o Diablo Canyon (04/28/15) o Columbia (06/04/15) o Palo Verde -Group 3
• sPRA due 12/31/20
• Public Meeting 06/09/15 Please let me know if you have any questions or concerns. Thanks. Nick Senior Project Manager -Seismic Reevaluation Activities U.S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Japan Lesson Learned Project Division nicholas.difrancesco@nrc.gov I Tel: (301) 415-1115 OFFICIAL USE ONLY-SENSITIVE INTERNAL INFORMATION INFORMATION POP Western US Seismic Screening and Prioritization Status May 5, 2015 PURPOSE: Brief NRR and NRO Management on the WUS Seismic Screening and Prioritization Review Letter EXPECTED OUTCOME: Understanding of the staff's review approach, conclusions and path forward detailed in the WUS Seismic Screening and Prioritization Review Letter PROCESS: Timeline
• March 2015 -WUS sites submitted their seismic hazard reevaluation (summary) reports including proposed interim action, when applicable. SSHAC reports were also made available
• April -June 2015-The staff plans to conduct individual public meetings with licensees to discuss the reevaluated hazards submittals.
• May 2015 -The staff plans to issue the screening and prioritization results letter for the WUS sites. Screening and Prioritization Letter Content
• Screening and prioritization review letter target for issuance is Tuesday May 12
• Review approach consistent with CEUS sites; WUS sites greater complexity due to unique source characterization and ground motion models
• No immediate safety concerns identified
• NRC targeting release of GMRS curve for SPRA development late 2015 Preliminary NRC screening determinations WUS Sites Seismic Risk Interim Limited Scope ESEP Evaluation Actions Evaluations Columbia Generating Station Group 1 Yes Yes Jan 2016 (acceptable) (SFP/HF) Diablo Canyon Power Plant, Unit Group 1 Yes Yes Jan 2016 Nos. 1and2 (acceptable) (SFP/HF) Palo Verde Nuclear Generating Conditionally in Yes Yes Jan 2016 Station, Units 1, 2, and 3 Group 3 (acceptable) (SFP/HF) Plant safety and interim actions
• Diablo Canyon (DC) screens-in to perform a detailed risk evaluation as a Group 1 plant. For interim action, DC has demonstrated margin above their GMRS by comparing their design basis (Hosgri) and the LTSP earthquakes to the reevaluated GMRS.
• Columbia screens-in to perform a detailed risk evaluation as a Group 1 plant. For their interim action, the licensee referenced their IPEEE seismic PRA results along with recent updates to their models to demonstrate capacity above their GMRS.
• Palo Verde conditionally screens-in to perform a detailed risk evaluation as a Group 3 Plant due to a small exceedance of the SSE. Palo Verde will provide a supplemental letter to provide details regarding their interim action review, their seismic licensing basis and justification for not performing the ESEP review.
• NRG staff has found that WUS sites may continue to operate while additional safety assessment are conducted. OUTCOMES:
• Alignment on seismic screening letter content and preliminary results
• Awareness of plant seismic evaluations and interim actions
• Awareness of communication and review timeline Communication Plan Timeline (ADAMS ML14083A619) Date Activity (responsible organization) Sig_nifjcant Historic Actions Completed (2/20/14) Issued letter to all licensees Re: Operability, Reportability, Interim Evaluation and Actions (ML14030A046) Completed (5/9/14) Issued Central and Eastern US (CEUS) Seismic Screening Letter (ML14111A147) WUS Seismic Hazard Screening Review Completed (3/12/15) NRC Receipt of WUS Hazard Reports (JLD/licensees) Completed (3/30/15) NRC/NEI Seismic Public Meeting w/ Discussion of WUS Review Process Completed (4/15/15) Target for public meeting notice of April 28 Diablo Seismic Meeting (JLD-DiFra ncesco) Completed 4/27 /15 Public availability of NRC and licensee slides for April 28 meeting (JLD -DiFra ncesco) Completed 4/28/15 Diablo Canyon Public Meeting on 2.1 Seismic (NRR/JLD, NRO/DSEA, Licensee) Completed 4/29/15 Complete WUS screening & prioritization technical review (NRO/DSEA) 5/7/2015 Distribute WUS screening & prioritization letter to R-IV, OPA, OCA, OEDO (NRR/JLD liaison team) 5/11/2015 Notice to states, congressional, licensee issuance, and NGOs of pending issuance (RSLO, OCA, JLD) 5/12/2015 Issue WUS screening & prioritization letter licensees including review of interim evaluation and actions (NRR/JLD) Issue Press Release on prioritization review (OPA) 6/4/15 Columbia Public Meeting on Methods (NRR/JLD, NRO/DSEA, Licensee) 6/9/15 Palo Verde Public Meeting on Methods (NRR/JLD, NRO/DSEA, Licensee) 6/23/15 Diablo End of Cycle Meeting and Open House (R-IV) late Summer Columbia End of Cycle Meeting (R-IV) Continuing Staff assessment of the reevaluated seismic hazard (NRO/DSEA, NRR/JLD) Points-of-contact: TBD DiFranccsco, Nicholas From:DiFrancesco, Nicholas Sent:27 Apr 2015 17:33:54 +0000 To:'Jahangir, Nozar';Socncn, Philippe R Cc:Strickland, Jearl

Subject:

Bridgeline and Webcast Information for NRC/PG&E Public Meeting on April 28 Attachments:NRC Slides for DCPP mtg Apr 2015.pdf Folks, A few meeting logistics. NRC Slides Attached. The webcast can be watched at: http://video.nrc.gov/ For awareness, there will be a small delay between the bridgeline and the internet webcast. Bridgeline Information Licensee Lines 888-469-1602 PC: 10973 Public Meeting Lines 888-792-8503 PC: 3081295 Please let me know if you need anything additional. Thanks, Nick Senior Project Manager -Seismic Reevaluation Activities U.S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Japan Lesson Learned Project Division nicholas.difrancesco@nrc.gov I Tel: (301) 415-1115 l'rotecting f:Jeopl.e and the E11viron1nent Near-term Task Force Recommendation 2.1 Seismic Hazard Evaluation Pacific Gas & Electric Company Public Meeting References and Logistics

• Public Meeting Agenda -ML 15105A528
• NRC Presentation Slides -ML 15117 A226
• Licensee Presentation Slides -ML 15117 A069
• Licensee Hazard Report -ML 15070A607 and ML 15070A608
• Meeting Feedback Form (request from njd2@nrc.gov)
• Webcast Archive at http://video.nrc.gov
• Meeting Summary to be issued within 30-day 2

\--U.S.NRC J ,.,_.., '" ou.o;n. rnmr Pratecti>l,r: Pu>/>le and thP. F.nvirmrmeut Meeting Purposes

• Gather additional information based on early identification of areas where additional technical information will support the staff's review
• Gain a better understanding of how the licensee conducted their evaluation 3

\--U.S.NRC J ,.,_.., '" ou.o;n. rnmr Pratecti>l,r: Pu>/>le and thP. F.nvirmrmeut Outline

• Background of NRC Near-term Task Force Recommendation 2.1 (NTTF R2.1)
• Current NRC approach to seismic hazard characterization
• Hazard characterization for NTTF R2.1
• Potential outcomes
• Focus questions for NRC review
• Timeline 4

\--U.S.NRC J ,.,_.., '" ou.o;n. rnmr Pratecti>l,r: Pu>/>le and thP. F.nvirmrmeut NTTF Report and Recommendations Recommendation 2 The Task Force recommends that the NRC require licensees to reevaluate and upgrade as necessary the design-basis seismic and flooding protection of SS Cs for each operating reactor. The Force that the direct the :ollmv1ng action:, to adequate protec:ion frorr natural pheno11ena, consistent with t1e curre1t of knowledge and anatyt cal rnet'1od: .. The:,e :,hould be ,mdertaken to prevent fuel and to erw.1re con:ainrnent and spent fuel pool integrity: 2. 1 Order licensees to reevaluate the seismic and flooding hazards at their sites against current NRC requirements and guidance, and if necessary, update the design basis and SSCs important to safety to protect against the updated hazards. 2.2 Initiate rulemaking to require licensees to confirm seismic hazards and flooding hazards every 10 years and address any new and significant information. If necessary, update the design basis for SSCs important to safety to protect against the updated hazards. 2.3 Order licensees to perform seismic and flood protection walkdowns to identify and address plant-specific vulnerabilities and verify the adequacy of monitoring and maintenance for protection features such as watertight barriers and seals in the interim period until longer term actions are completed to update the design basis for external events. RECOMMENDATIONS FOR ENHANCING REACTOR SAFETY iNrnE2151CENTU RY 5 \--U.S.NRC J ,.,_.., '" ou.o;n. rnmr Pratecti>l,r: Pu>/>le and thP. F.nvirmrmeut NRC 50.54(f} activities to address NTTF Seismic Recommendations uM1rED s r.e.rts NUCL£AR RFGULATORY COMMISSION ,.:.." Reac.:o* _ d111d H*:..1ct:"r'!I: llr Pt:'t*r Is 1r ;..;. '*v1:' .. ,.. ::;141 f'fa:..,1Jirft#to-., ac RE:).Jf::.S' roP. NFOrWAllO" l"l.;r.ISU.O.NI lll_L 10 :.:* 1Hf::. L.:.:;U} u* ,q !.If i?AJ 5-4:4' NG RCCC,,n.*ff\()ATIOf\S; 1 ').) AMi 9 :;. OF Tl-oE RE'JlE'.'* CF FRGA/ lHf::. DAl-ICHI 4\:C [;Et..1 , ... .... .. r,( 1(i1 .;, at the :..:r of t<:;54 .n 3meeidita. 3!"'*'.l t.. S 1 p,.qc ;,-*:: ;.Wur :i.:u::w ;. * ** Tit e 1 Q c:f t'le r:-.' f;*1:r_,* .. 11( CTR. PJH 5C P .. ... to ;,;f1J'*"St1JnS '- r;r 0'1 f¥t tn ,;JX..,,. 'er :he t.Jear. r v-n 'ali. *."-I If' :* re*1 "l?'w .,).;::; . .at rr.p F L.kustun:J Oa1 n.:r11 ".*::luat *ac ".'J T"it! "'II t!n::ahlr. :hr. w-t:!hAr Uv r:w:lr..,r .... 'f::> .. :,;.h:r tc T10d1f ro susc-?rallJd *Jf *evo .. i.:or (-01'[* "'<l?'d . :) C>R Par: In NT TF ; J 't"\l.,.dlll!J ..:1rnJ *l:J:.or.: **.g .mLJ f.",i:rofr..rol! ai! n1711 t*/ lo<::*1SJ'@$ 1 4 :.t le1:e* t:. m1la! y 1nf:Y'Y'l.l!1on .. "Lo::.i*)i--'&i. 3 *1.lrl! n:t :)'°: pt!*1**11s .;*v.:1t* 10 P:"trt s.:J Oj:t'!l:.:.1 *'9 ;>:,Im* 't:..lCtc;; .;'"l:S\"" 1{) C*R Pr. 5C ,..'" mqu*'n-j 't:"'rmrd 1::* .. ,1 nr , ** ,. r{"*: .. c:?1l'S .lr.::;.iienl ail 1.,t; n ... n ... t.:<:'\\'lf!' .. "!in)il *rn111 i*1c rJ ., 11. 201 , . T oriclo.u ... afl.e .lnd "S1.J:'l)t"l*Jon1 ts, .. RC *&*"'("0 "'TTf (* c *e.:t 1 n.e-"* P 1.l:-,1e-z :!t 4::tf 1 I\ Tfr w J ;arid ur .lr'!d :s.,d rf "*'ie**c)' should .Jdd1I ::*,a i1 .. ,)11 Tliofr.I*; ;t ..... ,.. ::' -::nnl.:11*1e.1t *'l *t "'lr. J., ,. ll i*: ;::'* * * *CCq'.1 ""'1c1e On.-.,, .. Ac:r.,..$'\ 01n:j "lo Ml 11 *.-.oi& opr:J U'§. .. ., i1 0C(°.$1!'l:'" ::>J*lt :uound :n@ .. cc:no**=** ,.. '°"'h*r.." IP"'*' nf 1.r10."h::***1 ... ,., 1l*: y3:1::i1' C.*1:J *. & ., f:;* *h L'.::t** r ,,.. .;a'r.1*1 f . .r.::t c:.n I!"<! arpr:-i.-ct-<1nrt :tit! :..:>pao1I rt1e N r a .. c rre the= C011LJi:=nte I<: o::ncl.10(t :l'\811 8., .... :..: lh! ful\ .. :s 'o <.;c;i:_r .,., lht-iU 1 f'"1e "RC "t'(ft ;:4:1n* "l1r:1i pld.t and <;0 llfe")lng ... *te$ ;l1ct "C1 ar-lr"!Tfll""IPnt r fn f1Ulil i; *r: dllO 50.54(f) Request for Information Letter issued March 12, 2012 * *

• Enclosure 1 (or R2.1 ): Seismic hazard and risk reevaluation Enclosure 3 (or R2.3): Seismic Walkdowns Other enclosures addressed flooding and emergency response 6

\--U.S.NRC J ,.,_.., '" ou.o;n. rnmr Pratecti>l,r: Pu>/>le and thP. F.nvirmrmeut Tiered-approach to Seismic Activities NTTF 2.3 -Seismic Walkdowns -COMPLETED reviews June 2014 licensees identify and address degraded, nonconforming, or unanalyzed conditions relative to a plant's current licensing and design bases. l. NTTF 2.1-Hazard Reevaluations: SUBMITTED CEUS:3/2014; WUS:3/2015 licensees reevaluate hazard based on present day guidance/methods used to define the design basis for new reactors. _.,/ NTTF 2.1-Interim Evaluation: COMPLETED CEUS: 4/2014; WUS: 4/2015 -\j If the design basis does not bound reevaluated hazard: licensees evaluated the need for interim evaluations using new seismic sources and ground motion with old hazard while the longer-term risk evaluation is performed. --'\ NTTF 2.1-Interim Expedited Approach (ESEP) CEUS: 12/31/2014; WUS: 1/16 . If the design basis does not bound reevaluated hazard: licensees perform interim evaluation to demonstrate key pieces of equipment for core cooling at a higher hazard using installed FLEX equipment \ up to 2 x SSE. Evaluate need for modifications while longer-term risk evaluation is performed. / NTTF 2.1-Seismic Risk Evaluations: June 2017-2020 l If the design basis does not bound reevaluated hazard: Licensees determine perform a seismic risk evaluation. Regulatory Actions NRC staff determines whether additional regulatory actions are necessary to provide additional protection against the updated hazards. 7 \--U.S.NRC J ,.,_.., '" ou.o;n. rnmr Pratecti>l,r: Pu>/>le and thP. F.nvirmrmeut Probabilistic Approach

• Previous studies such as 2011 Shoreline Fault Report and 2014 Coastal Commission Report were deterministic -Few selected scenario earthquakes -Limited treatment of uncertainty
• NTTF Recommendation 2.1 calls for seismic hazard reevaluations at each nuclear power plant using current NRG regulations
• Current NRG regulations and guidance specify a probabilistic approach for developing design ground motions
• Probabilistic ground motion hazards are characterized by a Ground Motion Response Spectrum or GMRS 8

\--U.S.NRC J ,.,_.., '" ou.o;n. rnmr Pratecti>l,r: Pu>/>le and thP. F.nvirmrmeut Development of Seismic Hazard for R2.1 Reeva I uations

• Licensees perform probabilistic seismic hazard analyses following NRC guidance (Regulatory Guide 1.208) **-*-c::::J ..*.* ... *. . . .. .. .. " .,,,., .. ..,,., ., ....
• CEUS licensees {96 units/59 sites) -Previously approved SSHAC Level 3 Models ...... -Plant-specific site analyses ....
• WUS licensees (6 units/3 sites) .________.,. i'. . . . . .. -Regional source and ground motion models developed by each Licensee using SSHAC Level 3 Studies -Plant-specific site analyses 9

, -U.S.NRC Screening Approach for R2. 1 Reeva I u at ions

• Screening approach specified in Industry Screening, Prioritization, and Implementation Details (SPID) Guidance
• SPID provides detailed guidance for -Development of GMRS -Seismic Risk Evaluations & Limited Scope Evaluations (high frequency, SFP)
• Plants with GMRS >SSE "Screen In" for -Interim Evaluations (and actions, as needed) -Expedited Interim Evaluations (and actions, as needed) -Seismic Risk Evaluations 10

\--U.S.NRC J ,.,_.., '" ou.o;n. rnmr Pratecti>l,r: Pu>/>le and thP. F.nvirmrmeut Outcome 1 ,, ,,,-----=--=-.::::-.::::: ___________ ---------::.,;;==::::*::_ ------0.1 10 frequency (Hz) Outcome 2 _£> c .Q -c;\lk\ (ti -"'I*. (i) t> /_--(/) -----------.-**-"' ____ /><,, "' 0 ------.:.::=--------**-***-*---. . 0.1 10 frequency (Hz) 10-: 10-: Potential Outcomes for R2.1 Reevaluations No Further Analysis Outcome 3 --S:-.1. \ v 0--00 -===------------' 0.1 -o lOC frequency (Hz) Industry Testing Program for High Frequency Sensitive components 11 ,J. NRC Review of SSHAC ...,, .... ... , ... , .. Studies for WUS Sites

• Did SSHAC process follow NRC guidance?
• How effective was the peer review panel?
• Have all applicable data been considered?
• Were data uncertainties identified and considered?
• Was an appropriate range of applicable models considered?
• How were models selected and weighted in the analysis?
• How were models assembled into the PSHA? 12

,-U.S.NRC NRC Review of '""" ,,,," ............ "'""""""" ._,, .. ... , ... , ... Source Models for WUS Sites

• How were seismic sources identified? -Geologic mapping -Geophysical observations -Earthquake catalog
• How were seismic sources characterized? -Geometry (location, length, dip) -Range of magnitudes -Faulting style (normal, reverse, strike-slip) -Slip rate and recurrence models -Complex rupture scenarios 13

\--U.S.NRC J ,.,_.., '" ou.o;n. rnmr Pratecti>l,r: Pu>/>le and thP. F.nvirmrmeut NRC Review of Ground Motion Models and Site Response for WUS Sites

• Do final ground motion models capture a reasonable range of alternative models?
• How were sources of uncertainty captured in model development?
• How were ground motion models adjusted for local site geology?
• Does site response analysis cover a reasonable range of alternative soil/rock properties?
• How was uncertainty in site response analysis incorporated into final probabilistic hazard curves? 14

\--U.S.NRC J ,.,_.., '" ou.o;n. rnmr Pratecti>l,r: Pu>/>le and thP. F.nvirmrmeut Hazard Development Expedited Interim Evaluations Risk Evaluations Higher Priority Lower Priority Hazard Analyses Expedited Interim Evaluations 2012 I Schedule for Seismic Hazard and Risk Evaluations 2013 2014 2015 2016 2017 2018 2019 2020 CEUS '\

• wus
• All plants CEUS 121ant mods I
• mods Only plants wus I with new
• I Group 1 I Risk Evaluations Staff acknowledgement to use GMRS for risk evaluation seismic hazard exceeding design basis Group 2 Group 3 (as needed) e Staff Assessment or response -15 Forthcoming Seismic Screening Letter
• Issuance of letter for WUS sites in ---2 weeks
• Diablo Canyon has screened-in for further risk evaluations and is a review priority
• No immediate safety issues identified
• Information supports safety assurance allowing additional time to complete the seismic risk evaluation 16

\--U.S.NRC J ,.,_.., '" ou.o;n. rnmr Pratecti>l,r: Pu>/>le and thP. F.nvirmrmeut List of Acronyms

• CELIS -Central and Eastern United States
• GMRS -Ground Motion Response Spectrum
• NRC-U.S. Nuclear Regulatory Commission
• NPP -Nuclear Power Plant
• NTTF -Near-Term Task Force
• SFP -Spent Fuel Pool
• SMA-Seismic Margins Analysis
• SPID -Screening, Prioritization, and Implementation Details SPID
• SPRA-Seismic Probabilistic Risk Assessment
• SSC-Structures, Systems and Components
• SSHAC -Senior Seismic Hazard Analysis Committee
• SSE -Safe Shutdown Earthquake
• SPID -Screening, Prioritization, and Implementation Details
• WUS -Western United States 17

,-U.S.NRC Break for NRC J ,.,_.., '" ou.o;n. rnmr Pratecti>l,r: Pu>/>le and thP. F.nvirmrmeut Staff Alignment

• 15 -20 minute planned break for NRC staff alignment to support meeting wrap-up
• Meeting to resume at 4:00pm (Eastern) or 1 :OOpm (Western) 18 Opportunity for Public Questions or Comments
• Additional Questions? Please ask us at: JLD _PublicResource@nrc.gov 19

\--U.S.NRC J ,.,_.., '" ou.o;n. rnmr Pratecti>l,r: Pu>/>le and thP. F.nvirmrmeut Backup Slides 20 , -U.S.NRC Additional WUS J ,.,_.., '" ou.o;n. rnmr Pratecti>l,r: Pu>/>le and thP. F.nvirmrmeut Seismic Hazard Reports Public SSHAC Reports

• Diablo Canyon http://www. pge. com/en/safety/systemworks/ dcpp/sshac/index. page 21

\--U.S.NRC J ,.,_.., '" ou.o;n. rnmr Pratecti>l,r: Pu>/>le and thP. F.nvirmrmeut Guidance Documents

• Two main guidance documents proposed by industry and endorsed by the NRC
• Screening, Prioritization, and Implementation Details (SPID) -Submitted by EPRI on November 2012 -Endorsed by NRC on February 15, 2013 -EPRl-1025287(ML12333A170)
• Seismic Evaluation Guidance: Augmented Approach (aka Expedited Approach) -Submitted by EPRI on April 9, 2013 -Endorsed by NRC on May 7, 2013 -EPRl-3002000704(ML13102A142) 22

\--U.S.NRC J ,.,_.., '" ou.o;n. rnmr Pratecti>l,r: Pu>/>le and thP. F.nvirmrmeut Seismic 2.1 Process Ensures Clarity, Consistency, and Informed Regulatory Decisions ----------------------------, PHASE 1 INFORMATION GATHERING STAGE 1 STAGE 2 Interact with Industry on Hazard and Risk Evaluation Guidance CEUS Licensees submit Site Response (9/2013 & 3/2014) Screened-in plants complete Expedited Approach Interim (CEUS: 12/31/2014;WUS: 1/2016) and Risk Evaluation (Group 1: 2017) N RC reviews Risk Evaluation ----------------1 PHASE 2 DECISION-MAKING N RC makes Regulatory Decisions as Needed *Safety Enhancements

• Backfit Analysis *Modify Plant License '----------------23 DiFranccsco, Nicholas From:DiFrancesco, Nicholas Sent:26 May 2015 17:40:31 +0000 To:Watford, Margaret Cc:Singal, Michael

Subject:

Columbia References for Seismic Hazard Reportability and Operability Reference for beyond design basis seismic hazard information:

• N RC letter to industry with guidance on tt1e content of seismic reevaluation submittals (February 20, 2014) Columbia Safety Basis -Section 5.0 Interim Evaluations contains Seismic GDF estimates and insights into plant capacity.
• http://pbadupws.nrc.gov/docs/ml1507/ML 15078A243.pdf DiFranccsco, Nicholas From:DiFrancesco, Nicholas Sent:2l Apr 2015 17:25:14 +0000 To: Munson, Clifford;Akc, Jon Cc :Jackson, Diane;Shams, Mohamed; Vega, Frankie;Graizer, Vladimir;John Stamatakos <jstam@swri.org> (jstam@swri.org);Hill, Brittain;Seber, Dogan;Vega, Frankie;Stirewalt, Gerry

Subject:

DCPP, Palo Verde, and Columbia Audit Information: SSHAC Documentation from PPRP-IT Team Folks, Please control distribution to the designated review team member for the following references. Following your audit review, please advise if information reviewed should be docketed to support development of the hazard staff assessment or RAls. DC Audit Information S:\Diablo Canyon R2.1 Seismic lnformation\SSHAC Documentation of PPRP-TI Team Palo Verde Audit Information S:\Palo Verde R2.1 Seismic lnformation\SSHAC Documentation of PPRP-TI Team Columbia Information is on ePortal (PM action to work through access controls). Also, licensee plans to work with PNNL to post information on public website. Thanks, Nick From: Soenen, Philippe R [1] Sent: Tuesday, April 21, 2015 10:49 AM To: Difrancesco, Nicholas Cc: Jahangir, Nazar

Subject:

DCPP information on Certrec Nick, We have uploaded the PPRP information onto Certrec IMS and granted access to Vladimir Grazier, John Stamatakos, and yourself. Here is how you get to the PPRP information in Certrec:

• Login to ims.certrec.com
• Click on "Inspections"
• Set status to "In Progress" and Plant to "Diablo Canyon"
• Click "Search" button.
• Click link to "Self-Assessment I Audit-Review of PPRP Comments and TIT Resolution"
• Click on the "NRC Requests" tab
• Click on what you would like to see.

Please let me know if you have any questions. Regards, Philippe Soenen Regulatory Services Office -805.545.6984 Cell -805.459.3701 PG&E is committed to protecting our customers' privacy. To learn more, please visit http://www.pge.com/about/company/privacy/customer/ Sticvc, Alice From:Stieve, Alice Sent:2l Apr 2015 13:45:28 -0400 To:DiFranccsco, Nicholas Cc:Jackson, Diane;Munson, Clifford

Subject:

FW: DCPP, Palo Verde, and Columbia Audit Information: SSHAC Documentation from PPRP-IT Team Nick please include me on future Palo Verde emails. I am the geologist and team lead on PY. Thanks. From: Hill, Brittain Sent: Tuesday, April 21, 2015 1:32 PM To: Stieve, Alice

Subject:

FW: DCPP, Palo Verde, and Columbia Audit Information: SSHAC Documentation from PPRP-IT Team From: Difrancesco, Nicholas Sent: Tuesday, April 21, 2015 1:25 PM To: Munson, Clifford; Ake, Jon Cc: Jackson, Diane; Shams, Mohamed; Vega, Frankie; Graizer, Vladimir; John Stamatakos <jstam@swri.org> (jstam@swri.org); Hill, Brittain; Seber, Dogan; Vega, Frankie; Stirewalt, Gerry

Subject:

DCPP, Palo Verde, and Columbia Audit Information: SSHAC Documentation from PPRP-IT Team Folks, Please control distribution to the designated review team member for the following references. Following your audit review, please advise if information reviewed should be docketed to support development of the hazard staff assessment or RAls. DC Audit Information S:\Diablo Canyon R2.1 Seismic lnformation\SSHAC Documentation of PPRP-TI Team Palo Verde Audit Information S:\Palo Verde R2.1 Seismic lnformation\SSHAC Documentation of PPRP-TI Team Columbia Information is on ePortal (PM action to work through access controls). Also, licensee plans to work with PNNL to post information on public website. Thanks, Nick From: Soenen, Philippe R [2] Sent: Tuesday, April 21, 2015 10:49 AM To: Difrancesco, Nicholas Cc: Jahangir, Nazar

Subject:

DCPP information on Certrec Nick, We have uploaded the PPRP information onto Certrec IMS and granted access to Vladimir Grazier, John Stamatakos, and yourself. Here is how you get to the PPRP information in Certrec:

• Login to ims.certrec.com
• Click on "Inspections"
• Set status to "In Progress" and Plant to "Diablo Canyon"
• Click "Search" button.
• Click link to "Self-Assessment I Audit -Review of PPRP Comments and TIT Resolution"
• Click on the "NRC Requests" tab
• Click on what you would like to see. Please let me know if you have any questions. Regards, Philippe Soenen Regulatory Services Office -805.545.6984 Cell
• 805.459.3701 PG&E is committed to protecting our customers' privacy. To learn more, please visit http://www.pge.com/about/company/privacy/customer/

Wyman, Stephen From:Wyman, Stephen Sent: 17 Mar 2015 20: 16: 12 +0000 To:Jackson, Diane Cc: Dev Ii n-Gi 11, Stephanie;M unson, Clifford

Subject:

FW: Palo Verde FSAR Diane, Palo Verde FSAR latest is Rev 17, ADAMS Accession Package No. ML 13214A057. The referenced sections were 2.5 for SSE and 3. 7 for the design basis. I don't see how they are *'special". Regards. Steve Stephen M. Wyman USNRC/NRRIJLDIHMB Office: 0-13G9 MS: 0-13C5 301-415-3041 (Voice) 301-415-8333 (Fax) Stephen.Wyman@nrc.gov From: Singal, Balwant Sent: Tuesday, March 17, 2015 4:08 PM To: Wyman, Stephen

Subject:

RE: Palo Verde FSAR Latest I know of is Revision 17. ADAMS Accession Package No. ML 13214A057. Thanks. Balwant K. Singal Senior Project Manager (Comanche Peak and Palo Verde) Nuclear Regulatory Commission Division of Operating Reactor Licensing Balwa nt.Singa l@nre.gov Tel: (301) 415-3016 Fax: {301) 415-1222 From: Wyman, Stephen Sent: Tuesday, March 17, 2015 3:52 PM To: Singal, Balwant

Subject:

Palo Verde FSAR Balwant, Can you please confirm for me the latest Rev of the FSAR for Palo Verde? I currently find Rev 16 dated June 2011 on the network. (Y:/CDIMAGES/FSAR) The staff has a question regarding their seismic design basis as it related to the recently submitted seismic hazard report. Thanks, Steve Stephen M. Wyman USNRC/NRRIJLDIHMB Office: 0-13G9 MS: 0-13C5 301-415-3041 (Voice) 301-415-8333 (Fax) Stephen.Wyman@nrc.gov DiFranccsco, Nicholas From:DiFrancesco, Nicholas Sent:25 Mar 2015 14:58:38 +0000 To:Hill, Brittain;Jackson, Dianc;Shams, Mohamed Cc:Wyman, Stephen

Subject:

FW: Palo Verde Pages from Original Plant SER Attachments:Pages from Palo Verde SER.pdf Folks, Spoke with APS, about beginning preps for an interim evaluation and licensing basis clarification letter. The licensee maintains that their history relatively short history is nuanced. Attached is a seismic SER excerpt that they said explained it. I don't think it changes the current understanding. Thanks, Nick From: Weber, Thomas N Sent: Tuesday, March 17, 2015 6:13 PM To: stephen.wyman@nrc.gov

Subject:

Palo Verde Pages from Original Plant SER Stephen, I am sending you some pages from our original plant safety evaluation report for your information and use. You will note the unique wording that the NRC used to described both the seismic site characterization values in section 2.5 as well as the seismic design values in section 3.7. We tried to distinguish the difference in our submittal. We look forward to future discussions on this topic. Thanks, TN Weber ... Department Leader Regulatory Affairs PVNGS 623-393-5764 I I / FOR INFORMATION ONLY NUREG-0057 Safety Evaluation Report_. .. related to the operation of . Palo Verde Nuclear Generating Station:;r Units 1, -2, and 3 Docket Nos. STN 50-528, STN 50-529, and STN 50-530 Arizona Public Service Company, et al. U.S. Nuclear Regulatory Commission Office of Nuc ... r RNctor Regulation November 1981 ., site. This is the largest earthquake which has been reported within 161 km (100 mi) of the PVNGS site. The staff concluded that this earthquake is associated with the Basin and Range Tectonic for the purpose of iaple11enttng Appendix A to 10 CFR Part 100 and found that a .agnitude 5.2 event could occur near the site (CP-SER for PVNGS 4-5, 1979). The other significant seismic zone is the zone containing the epicentral area of the 1887 Sonora Mexico earthquake. The Sonora earthquake was located about 443 km (275 *i) southeast of the PVHGS site. The reported epicentral intensity of the Sonora earthquake was K*KI (Modified Mercalli). The applicant's estimated .. gnitude is approxi*atey 7 3/4 to 8 (M5); the.Dubois and Sbar (1981) esti*ated *agnitude is 7 1/4 (M5). The applicant has assumed that an event similar in size to the 1887 Sonora earthquake of magnitude 8 occurs 116 km (72 mi} northeast of the site. This position corresponds to the closest approach to the site.of a line which coincides with e series of long northwesterly*trending valleys and atsociated Quaternary and capable faults which project ff'Oll the epicentral area to the Grand Canyon region. The Ari2ona Bureau of Geology and Mineral Technology, in eooperat;on with the Department of Geosciences, University of Arizona, is conducting a study of historical seismicity in Arizona, partly funded by the NRC. Early results from the study (Dubois, 1980) summarize previous earthquake investigations, the current attempt to document historical earthquakes in Arizona, and analysis of the location and size of these historic earthquakes. The historical quakes have been tentatively grouped into four basic zones of seismicity. The staff has reviewed the technical progress report (Dubois, 1980) and finds no impact resulting from this study on the seismic risk for the PVNGS site. The applicant has agreed to update the FSAR to include the results of this study when completed. 2.S.2.4 Safe Shutdown Earthquake (SSE) In determining the SSE, the staff has followed the tectonic province approach described in Appendix A to 10 CFR Part 100. The applicant has proposed an SSE acceleration level of O.ZOg which corresponds to an event of magnitude 8 similair in size to the 1887 Sonora earthquake occurring at a distance of 116 km (72 mi) northeast of the site. This acceleration value is used as the high frequency input to a RG 1.60 response spectrum. During the CP review, the USGS agreed with the applicant's conclusion that an acceleration of 0.2g is adequate for use 1t the site (CP*SER for PVNGS 1*3, Supp. No. 2, 1976). The USGS examined the following situations in assessing the adequacy of the proposed SSE. 1. A San Andreas-type event of magnitude 8+ about 200 km (124 mi) from the site. .... 2. A *agnitude 8 Sonora. Mexico-type event 115 km (72 mi) from the site. 3. A random event of magnitude 5.0 within the site province. During the CP review, the staff and the USGS assessed the adequacy of the SS£ for the above situations based on 1) empirical relations among magnitude, Palo Verde SER 2-24 01 o' 11 \ FOR INFORMATION ONLY epicentral distance and accleration, and relations among acceleration, intensity and distance and 2) empirical relations among site intensity, epicentral intensity and distance and relations between acceleration and intensity. The spectra four seismograms from the 1952 Kern County earthquake and two from the 1971 San Fernando earthquake were scaled for distance and magnitude. The applicant showed that the resultant spectra are conservatively enveloped with the RG 1.60 spectrum anchored at 0.2g. The staff and the USGS agreed that for the Palo Verde site, 0.2g is an adequate value to be used as the high-frequency input to RG 1.60 response spectra. In the CP review for Units 4 and 5 at the PVNGS site (CP-SER for PVNGS 4-5, 1979), the staff considered the effects of a magnitude S.2 earthquake similar to the 1976 Prescott event occurring near the site. (Detailed geologic gations in the site area have precluded the existence of any capable *faults within 8 km (5 mi) of the site.) Based again on empirical relationships. the staff concluded that the acceleration from a *agnitude S.2 earthquake assumed to occur 8 km (5 mi) from the site would not be expected to exceed 0.2g. The staff's position is that the following seismic hazards likely to affect the PVNGS site should be considered: 1. A magnitude 8 Sonora. Mexico-type event at a distance of 115 km (72 mi) from the site. 2. A random event of magnitude 5.2 (ML). Since the CP review for Units 4 and S, all available information supports the position that the SSE response spectra are conservative for a Sonora-type event at 115 km (72 mi) from the site. The applicant has further demonstrated the ** conservatism of the 0. 2g SSE design spectrum with respect to a nearby magn tude 5.2 event by comparing the SSE and site-specific spectra generated by Lawrence Livermore Laboratories (LLL) (1979). The SSE spectrum exceeds the 84th percentile LLL spectrum for magnitude 5.3 at soil sites at all periods except for minor exceedance between 0.04 and 0.05 seconds. The SSE spectrum the SOth percentile LLL spectrum at all periods by factors between 2 and 10. The staff and the staff consultant at Los Alamos National Laboratory agree that the proposed acceleration value of O.ZOg, as the high frequency anchor to a RG 1.60 response spectrum, is adequately conservative as the SSE for the PVNGS site. 2.S.2.S Operating Basis Earthquake (OBE) The applicant has proposed O.lOg for the acceleration level corresponding to the OBE. The design vibratory ground acceleration for the OBE is taken to be one-half of the design vibratory ground acceleration for the SSE, consistent with dix A to 10 CFR 100. Considering the low seismicity near the PVNGS site, the staff concludes that the proposed acceleration viHue for the OBE is adequately conservative. 2.5.3 Surface Faulting Post-CP (Units 1, 2, and 3) site and regional subsurface information reinforces the NRC staff finding that there is no known evidence either at the PVNGS 1-3 site or within 8 km (5 mi) of the nuclear plants to indicate surface Palo Verde SER 2-25 I I FOR INFORMATION ONLY 3.7 SEISMIC DESIGN 3.7.1 Seismic Input The input seismic design response spectra based on the Maximum horizontal ground motion of 0.13 g for OBE and 0.25 g for SSE and applied in the design of BOP seismic Category I structures, systems. and components comply with dations of RG l.60, Design Response Spectra for Nuclear Plants.** The specific percentage of critical damping values used in the seismic analysis of Category I structures, systems and components within the balance*of-plant (BOP) scope are in conformance with RG 1.61, "Damping Values for Seismic Analysis of Nuclear Power Plants ... The synthetic time history used for the seismic design of BOP Category I plant structures, systems and components is adjusted in amplitude and frequency content to obtain response spectra that envelope the response spectra specified for the site. Conformance with the reconmendations in RG 1.60 and RG 1.61 provides reasonable assurance that the seismic inputs to BOP Category I structures, systems, and components are adequately defined to assure a conservative basis for the design of such structures, systems and components to withstand the consequent seismic loadings. A discussion of the. conformance of the spectra and damping values used in the design and analysis of NSSS Category I structures, systems. and components with RG 1.60 and RG 1.61 is contained in NUREG-0852. Section 3.7. The staff concludes that the PVNGS response spectra 3re enveloped by the response spectra developed for the NSSS components, and, therefore. the CESSAR interface requirements are satisfied. The staff does have a concern on the use of high damping values in the design of cable trays for PVNGS 1-3. Since these damping values are much higher than those recommended in RG 1.60 for steel structures. the staff requested that the applicant provide the theoretical basis and a further discussion of the experimental data for staff review and evaluation. The resolution of this item is pending receipt, review and acceptance of this information. 3.7.2 Seismic System Analysis and Seismic Subsystem Analysis (Structural) The scope of review of the seismic system and subsystem analys;s for PVNGS 1*3 Category I structures, systems and components included the seismic analysis. It also included a review of procedures for Modeling, seismic soil*structure interact;on, development of floor response spectra. inclusion of torsional effects, evaluation of seismic Category I structures overturning, and determina* tion of composite damping. In addition, the review included design criteria and procedures for evaluation of the interaction of nonseismic Category I struc* tures with seismic Category I structures. effectS""Of parameter variations on floor response spectra, and seismic Category l buried piping outside the ment. A discussion of the review of the seismic analysis of the structural. components of NSSS systems and subsystems is found in NUREG-08S2, Section 3.7. A structural engineering audit was held during the week of August 10. 1981. At the conclusion of that meeting, the staff requested that the applicant furnish justification that the corridor building and a Category I buried pipeline had Palo Verde SER 3*17 V cga, Frankie From: Vega, Frankie Sent:3 Jun 2015 11:07:58-0400 To:DiFranccsco, Nicholas

Subject:

FW: Proposed agenda -Public meeting to discuss Columbia's seismic hazard reevaluation From: Williams, Lisa L. [3] Sent: Thursday, May 21, 2015 3:57 PM To: Vega, Frankie

Subject:

RE: Proposed agenda -Public meeting to discuss Columbia's seismic hazard reevaluation See minor change in red below From: Vega, Frankie [4] Sent: Tuesday, May 19, 2015 1:51 PM To: Williams, Lisa L.

Subject:

RE: Proposed agenda -Public meeting to discuss Columbia's seismic hazard reevaluation Thanks Lisa! From: Williams, Lisa L. [5] Sent: Tuesday, May 19, 2015 4:43 PM To: Vega, Frankie; Rogalski, Richard J. Cc: Difrancesco, Nicholas

Subject:

RE: Proposed agenda -Public meeting to discuss Columbia's seismic hazard reevaluation Frankie. Here are the attendees for Energy Northwest: In person Dave Swank-Assistant Vice President, Engineering and Fukushima Project Leader Mike Kennedy-PSA/Safety Analysis Supervisor Lisa Williams -Licensing Supervisor Greg Lisle -Design Engineer Kevin Coppersmith -consultant Bob Youngs -consultant Via telephone Bob Bryce -consultant Habib Shtaih -PSA Engineer Rich Rogalski -Licensing Engineer From: Vega, Frankie [ mailto: Frankie.Vega@nrc.gov] Sent: Tuesday, May 19, 2015 12:53 PM To: Williams, Lisa L.; Rogalski, Richard J. Cc: DiFrancesco, Nicholas

Subject:

Proposed agenda -Public meeting to discuss Columbia's seismic hazard reevaluation Mrs. Williams and Mr. Rogalski; My name is Frankie Vega and I'm one of the PMs involved with 2.1 Seismic. Please see the agenda below for the upcoming public meeting on Columbia's reevaluated seismic hazard. Feel free to modify the agenda if needed. I would appreciate your comments/edits by COB Thursday since I plan to issue the meeting notice this Friday. Also, please send us a list of your staff and contractor personnel that are planning to participate in the meeting (either attending or calling -in). Feel free to contact either Nick or me with any questions. Time 12:00-12: 15 12:15* 12:30 12:30-2:45 2:45-3:05 3:05-3:20 3:20-4:00 Thanks! Topic Introductions Overview of R2.1 Seismic -Discussion of meeting goals and expected outcome Presentation of Seismic Reevaluation Report SSHAC Activities Seismic Source and Ground Motion Model Technical Focus Areas and Discussions Discussion of licensee next steps Planned Break NRC Meeting Wrap-up Technical Wrap-up, review of focus areas and next steps Public Questions or Comments Speaker NRC/Energy Northwest NRC Energy Northwest NRC Public/NRC ..... Frankie G. Vega, P .E. Project Manager NRR/JLD/JHMB 301-415-1617 Location: 0-13Hl2 DiFranccsco, Nicholas From:DiFrancesco, Nicholas Sent:l4 May 2015 16:07:06 +0000 To:NRR-PMDA-ECapturc Resource Cc:50.54f_Seismic.Resource@nrc.gov

Subject:

FW: Written concerns -April 28th, 2015 webcast meeting with PG&E Attachments:Written concerns -April 28th, 2015 webcast meeting with PG&E Please add to PUBLIC ADAMS, sunsi review complete. A release date of May 21 is preferred. Thanks, Nick Senior Project Manager -Seismic Reevaluation Activities U.S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Japan Lesson Learned Project Division nicholas.difrancesco@nrc.gov I Tel: (301) 415-1115 STATE OF CALIFORNIA EDMUND G. BROWN JR., GOVERNOR Independent Peer Review Panel A pcvl'U!/b ef J-'fJ/1:-J*-m-vo fuvg-a-rd,, ;pe,c.-;,a,Z.,,:-;*tJ* f!/,,,C-a;biv,yft.ed,, try t"M Ca;[,:,f'o-rl'l/ia-pul>-lz,o U t"t/Ut'UJ-* C o-m/Jn/v,1-;1*iorl/ CALIFORNIA GEOLOGICAL SURVEY, CALIFORNIA COASTAL COMMISSION CALIFORNIA PUBLIC UTILITIES COMMISSION, CALIFORNIA ENERGY COMMISSION CALIFORNIA SEISMIC SAFETY COMMISSION, COUNTY OF SAN LUIS OBISPO IPRP Report No. 8, December 17, 2014 Comments on PG&E's Central Coastal California Seismic Imaging Project Report part 2: onshore seismic studies intended to reduce the uncertainty in seismic hazard at Diablo Canyon Power Plant BACKGROUND In 2006, the California Legislature enacted Assembly Bill (AB) 1632, which was codified as Public Resources Code Section 25303. AB 1632 directed the California Energy Commission (CEC) to assess the potential vulnerability of California's largest baseload power plants, which includes Diablo Canyon Power Plant (DCPP), to a major disruption due to a major seismic event and other issues. In response to AB 1632, in November 2008 the CEC issued its findings and recommendations in its AB 1632 Report, which was part of its 2008 Integrated Energy Policy Report Update. In Pacific Gas and Electric Company's (PG&E) 2007 General Rate Case decision D.07-03-044, the California Public Utilities Commission (CPUC) directed PG&E to address and incorporate the recommendations from the AB 1632 Report into its feasibility study to extend the operating licenses of its Diablo Canyon Units 1 and 2 for an additional 20 years. In November 2009, PG&E submitted its formal application with the Nuclear Regulatory Commission to extend the licenses of DCPP Units 1 and 2. In 2010 PG&E filed for cost recovery with the CPUC for expenditures associated with the enhanced seismic studies recommended by the CEC's AB 1632 Report. The motions for cost recovery were subsequently approved in 2010 and 2011 . CPU C Decision D .10-08-003, issued on August 16, 2010, established that the CPUC would convene its own Independent Peer Review Panel (IPRP) and invite the CEC, the California Geological Survey, the California Coastal Commission, and the California Seismic Safety Commission to participate on the panel. Under the auspices of the CPUC, the IPRP is conducting an independent review of PG&E's seismic studies including independently reviewing and commenting on PG&E's study plans and the findings of the studies. The comprehensiveness, completeness, and timeliness of these studies will be critical to the CPUC's ability to assess the cost-effectiveness of Diablo Canyon's proposed license renewal. As noted in the CEC's AB 1632 Report, a major disruption because of an earthquake or plant aging could result in a shutdown of several months or even cause the retirement of one or more of the plants' reactors. A long-term plant shutdown would have economic, environmental and reliability implications for California ratepayers. This report by the IPRP responds to reports released by PG&E on September 10, 2014. Those reports are collectively referred to as the Central Coastal California Seismic Imaging Project (CCCSIP) report. The CCCSIP report is divided into 14 chapters focused on individual studies. This review, and subsequent reviews of the CCCSIP, are divided into sections based on factors that are important to seismic hazard analysis and the studies intended to help constrain those factors. In this organization and emphasis, these reports by the IPRP follow the format of IPRP Reports No. 2 and 3 and refer to investigation "targets" described in a memo report "Response to IPRP Request for Hazard Sensitivity for Targets for the DCPP Geophysical Surveys," that was prepared by the PG&E Geosciences Department and dated August 8, 2011. Due to the large volume of information in the CCCSIP report, the IPRP chose to review it in three parts. The second part includes onshore seismic studies and the hazard parameters that they are designed to study. These studies, Chapters 7, 8, 9 and 12 of the CCCSIP report, were the subject of a public meeting on November 17, 2014 and of this report. At the IPRP meeting on November 17, 2014, PG&E project manager Stuart Nishenko presented an update of the "tornado diagram" from the August 11, 2011 memo report. In the updated "tornado diagram" (Figure 1 ), the distance between points related to a hazard parameter represents the uncertainty in seismic hazard resulting from that parameter. In this type of diagram, parameters that are poorly constrained and have a Hosgri Slip Ra1e . *J Hosgri Dip-+----------",_.------++-----< Shoreline Slip Rate . .J* Hosgn -San Simeon Step Over * *..!I

• Los Osos Dip *..!l*..!1* *_J
• Los Osos Sense of Slip +-------+---1t----1 *J Shoreline and Hosgri Linking . *..!I 2011 2014 Los Osos Slip Rate+-------;,,,. .. _ -+-------+---t Shoreline Segmentation Shoreline Southern End -+--------------+---< 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 Figure 1. "Tornado diagram" from CCCSIP report. chapter 14, showing seismic hazard parameters and related uncertainty in seismic hazard. Values depicting state of knowledge in 2011 and 2014 show reduction in uncertainty related, in part, to CCCSIP studies.

large effect on hazard are shown as widely separated points at the top of the diagram. Closely spaced points shown near the base of the diagram can be either parameters that are well-constrained or parameters that are poorly-constrained but have slight effect on hazard. As stated by Dr. Nishenko, reducing the uncertainty in the parameters near the top of the "tornado" will have the greatest effect in reducing the uncertainty in hazard. The depiction of uncertainty in 2011 and 2014, particularly the lower uncertainty for the parameters at the top of the "tornado" show PG&E's estimate of how much uncertainty in seismic hazard has decreased due to studies described in the CCCSIP report. The parameter with the greatest impact on seismic hazard, slip rate on the Hosgri fault, was the main subject of IPRP Report No. 7. This report includes discussion of seismic hazard parameters including dip and sense of slip on the Los Osos fault (fourth and fifth from the top of the "tornado"). The IPRP notes that the parameters shown on the "tornado diagram" are the parameters included in the 2011 seismic hazard analysis. As stated in IPRP Reports No. 2 and 3, an important emphasis of on-land seismic surveys should be to determine if there are additional faults that should be considered and an overall "tectonic model" describing the location. sense of slip, and level of activity on faults within the Irish Hills. As in IPRP Report No. 7, the IPRP notes that the parameters shown on the "tornado diagram" are all "seismic source characterization" parameters. Other parameters, especially "site conditions" or "site amplification" parameters can have equal or greater impact on seismic hazard calculations as any shown on Figure 1. Site conditions and seismic amplification factors were the subject of IPRP Report No. 6 and are discussed in other sections of the CCCSIP report. These factors will be addressed in a subsequent IPRP report. Seismic hazard parameters addressed in Chapters 7, 8, 9 and 12 of the CCCSIP report and discussed here are:

• Los Osos dip
• Los Osos sense of slip
• Tectonic model of the Irish Hills
• Evaluation of hazard related to the Diablo Cove fault and the San Luis Range Fault. The major emphasis of this part of the CCCSIP is to develop a complete and consistent tectonic model of the Irish Hills, which includes dip and sense of slip on all faults, including the Los Osos fault. This review, therefore. follows the general organization of the CCCSIP report and presentations at the IPRP meeting on November 17, 2014, beginning with, 1) a discussion of studies intended to develop tectonic models of the Irish Hills, 2) how well those studies constrain seismic hazard parameters, (e.g.,dip of IPRP Report No. 8, Page 3 the Los Osos fault), and 3) use of those models in seismic hazard analysis. A separate section discusses Chapter 12 of the CCCS IP report, which is an evaluation of fau Its and tectonic models proposed by Dr. Douglas Hamilton and presented by Dr. Hamilton at the IPRP meeting on November 17, 2014. Onshore seismic interpretation program (ONSIP) The major data collection efforts described in Chapters 7, 8 and 9 of the CCCSIP report were seismic surveys of the area surrounding the DCPP, including the Irish Hills collectively referred to as the onshore seismic interpretation program (ONSIP). This effort was supplemented by updated geologic mapping, new surveys of gravity and magnetics, and interpretation of available data from previous oil and water wells. Seismic surveys were conducted in 2011 and 2012 and consisted of two types of seismic sources and arrays of receivers. The sources, truck-mounted Accelerated Weight Drop (AWD) and Vibroseis vehicles, were deployed along roads throughout the Irish Hills and receivers were deployed on the roads and in grid arrays where allowed by the terrain and landowners. As described in the CCCSIP report and in the November 17, 2014 IPRP meeting by Dr. Daniel O'Connell of Fugro Consultants, the highly irregular source and receiver layout posed challenges for processing, hence all data were processed with 30 methods. Processed seismic survey data were presented in the CCCSIP report and at the IPRP meeting as 2-dimensional cross sections along the lines where surveys were conducted, mainly along roads across the hills. In general, AWD surveys produced relatively high resolution to shallow depths and Vibroseis surveys produced lower resolution to greater depth. The surveys show "reflections" related to changes in seismic velocity of the materials. The processed seismic reflection data were interpreted by a team from PG&E and their consultants. The CCCSIP report (Chapter 7, page 25) lists assumptions upon which the team's interpretations are based, including: "We assume that variations in the acoustic properties of the rocks that give rise to the seismic reflectors directly or indirectly represent real geologic structure". In practice, observed reflections generally are assumed to represent bedding or other geologic fabric. The reflections further arre assumed to be caused by contrasts in acoustic impedance (the product of acoustic velocity and rock density) between adjacent geologic features. Faults are assumed to truncate or offset otherwise continuous geologic units, and thus are interpreted from related changes in observed reflections. Note also that the interpretation of seismic sections needs to take into account the possibility that some observed events are artifacts. On a given 20 section, observed reflections may come from features that are not in the plane of the cross-section. Observed events may also be artifacts created by assumptions built into the seismic data processing. Use of the sections derived from the IPRP Report No. 8, Page 4 seismic survey data to develop a tectonic model of the Irish Hills is described in Chapter 7 of the CCCSIP report. This chapter and the presentation by Dr. Jeff Unruh at the IPRP meeting on November 17, 2014 describe the evidence for the Los Osos, Edna. San Miguelito, San Luis Bay and additional un-named faults. Chapter 7 and the presentation emphasized the seismic surveys, but also described the use of geologic mapping, surveys of the gravity and magnetic fields, and well data in developing a tectonic model for the Irish Hills. The tectonic model described in Chapter 7 of the CCCSIP report includes a series of faults, generally dipping steeply toward the center of the hills (Figures 5-30, 5-31 and 5-32 of the CCCSIP report). The major faults are interpreted as having formed as extensional faults (normal faults) during Miocene time. Movement on these faults formed a deep basin that was filled with sediment that became the Obispo, Monterey, and Pismo Formations. In this model, faults formed as normal faults, possibly with some lateral displacement, in the Miocene then were reactivated as reverse faults, also possibly with some lateral displacement, in the Quaternary. This model is consistent with 1) potential field (gravity and magnetic) data, 2) the great thickness of Miocene sedimentary rocks encountered in the "Honolulu-Tidewater 1" oil well in the central Irish Hills, and 3) surface geologic mapping. The CCCSIP report does not thoroughly address the extent to which the geologists who developed this model considered alternative models which match the observed data equally well. Neither does the CCCSIP quantify the impact of potential alternative models on the seismic hazard. These issues were the subject of discussion at the IPRP meeting on November 17, 2014, which is summarized below. There are two types of questions about the faults that are included in the tectonic model: How well documented are they? And how much do they contribute to seismic hazard? Some faults, such as the Edna and San Luis Bay faults, are known from surface geologic mapping and can be projected some distance into the subsurface using the seismic reflection data. In some instances, truncated reflections in seismic sections presented in the CCCSIP report can reasonably be attributed to the downward extension of known surface faults. Such correlation of truncated reflections with surface faults can be accomplished with some confidence in the shallow subsurface, but becomes increasingly difficult with depth. The IPRP is not convinced that the interpretations of the down-dip extensions of faults are well constrained, even in the case of well-documented surface faults. Similarly, faults interpreted from the seismic sections, but not corroborated by surface mapping, (e.g. faults interpreted between the San Miguelita and Edna faults) are possible, but are by no means unique interpretations of the data. Overall. the IPRP is not convinced that projections of faults beyond the very shallow subsurface represented unique interpretations of the data. IPRP Report No. 8, Page 5 Projections of faults to depth in "basement" rocks of the Franciscan complex appear to be even more problematic. As discussed at the IPRP meeting on November 17, 2014, the Franciscan complex is known to be a mixture of different rock types pervasively sheared at a variety of scales and is not expected to produce reflectors that are extensive over broad areas. The majority of seismic sections, (e.g. AWD line 150 as presented on Chapter 7, Figure 5-25) show prominent, continuous reflectors at relatively great depths in material that is assumed to be bedrock of the Franciscan complex. Most deep reflectors shown on Figure 5-25, and in many other sections are arranged in groups of concave-upward, gently curved reflectors. These reflectors are interpreted in the CCCSIP report as representing geological structure. The IPRP, however, regards this pattern of concave-upward sets of reflectors as difficult to explain geologically, but not difficult to envision as artifacts from the data processing. If the continuous reflectors in Franciscan complex bedrock are artifacts of data processing, rather than representing geologic structure, then the seismic reflection surveys provide no constraint on the down-dip geometry of faults in the Franciscan Complex. The Los Osos fault, in particular, is entirely within Franciscan Complex rocks from very shallow depths. If the reflection surveys do not show real geologic structure along the down-dip extension of this fault, then dip of the fault remains essentially unconstrained. The question of how important the faults included in the tectonic model of the Irish Hills are in terms of seismic hazard is not addressed in the CCCSIP report, but was partly addressed in a presentation by Dr. Steve Thompson of Lettis Consultants International at the IPRP meeting on November 17, 2014. In that presentation, Dr. Thompson explained how the "Technical Integration (Tl) Team" working within the U.S. Nuclear Regulatory Commission's Senior Seismic Hazard Analysis Committee (SSHAC) process is developing input to the seismic hazard analysis. In contrast to the CCCSIP report, which attempts to present a single tectonic model as a unique result of the geophysical surveys, Dr. Thompson reports that the SSHAC "Tl team" is developing three alternative tectonic models for input into their seismic hazard analysis. One of these models is similar to the model described in the CCCSIP report, with faults that dip steeply toward the center of the Irish Hills, the two others are dominated by more gently dipping faults that dip either to the northeast or to the southwest. All else being equal, a tectonic model with relatively gently dipping thrust faults may result in higher hazard at Diablo Canyon for two reasons: the known vertical uplift of the Irish Hills requires a higher slip rate on a gently dipping reverse fault than on a steeply dipping one and most ground motion prediction equations predict higher ground motion for sites above (on the hanging wall of) thrust faults. IPRP Report No. 8, Page 6 The CCCSIP report describes some of the data to support a tectonic model including thrust faulting in discussion of the Honolulu-Tidewater 1 well (Chapter 7, page 43). It also presents analysis of seismicity that can be used to support a tectonic model that includes thrust faulting, based on the work presented by Dr. Jeanne Hardebeck (SSHAC workshop in San Luis Obispo, March, 2014, see (Chapter 12, Figure 6-47). The CCCSIP report does not, however, present a tectonic model with gently dipping thrust faults. Dr. Thompson's presentation indicates that the SSHAC seismic hazard analysis will consider three alternative tectonic models of the Irish Hills, including two with gently dipping thrust faults. The IPRP supports the concept of including three different tectonic models in seismic hazard analysis and has not seen a compelling reason to favor the model presented in the CCCSIP report over the other two described by Dr. Thompson. CONCLUSIONS IPRP review of the tectonic model is based on the CCCSIP report and presentation. The IPRP has not had time, to review the seismic data processing in detail. In addition, a full auditing of the seismic data acquisition and processing sequence would require the IPRP to retain outside consulting services. Evaluation of the figures showing seismic sections, however, has led to the following general conclusions:
• Seismic imaging of geologic structures deep beneath the Irish Hills was expected to present a significant challenge for both data acquisition and interpretation. The data and interpretations presented in the CCCSIP report increase our knowledge of several faults in the Irish Hills, particularly in the shallow subsurface. With increasing depth, however, there appears to be less support for the assumption that the "reflectors" shown in seismic sections represent "real geologic structure". As noted at the IPRP meeting, the most prominent, continuous reflectors in many sections are from relatively great depth in material that is assumed to be bedrock of the Franciscan complex. Since the Franciscan complex is known to be a mixture of different rock types pervasively sheared at a variety of scales, continuous, gently dipping layers are not expected. The overall arrangement of the gently dipping "reflectors" also raises questions that are not addressed in the report. In several sections, the arrangement of reflectors does not resemble a cross-section of folded or faulted rock. The pattern of concave-upward sets of reflectors seen in many sections does not have an obvious geological explanation, leading the IPRP to question whether they represent real geologic structure.
• Even if all reflectors shown in the seismic sections are images of geologic features, the interpretations of various faults are inconsistent and not unique: 1) In many cases, faults are interpreted based on a series of truncated reflectors, IPRP Report No. 8, Page 7 but are shown to pass through other reflectors that are not truncated: 2) In some seismic sections, it appears that additional faults are permitted by the data. It is not clear how the stated interpretation methodology allowed the interpretation team to draw some faults and not others; and 3) Alternate interpretations of the dip of most faults are possible. This concern applies to the dip of the Los Osos fault. Alternate dips, including relatively low-angle dips, of the Los Osos fault appear to be possible through sections 138-149 and 150 as shown on Figures 5-24 and 5-25 of the CCCSIP report. The reduction in uncertainty in seismic hazard depicted on the "tornado diagram" for dip of the Los Osos fault appears to be based on the CCCSIP report conclusion that the new data precludes low-angle dips. The IPRP does not concur that low-angle dips are precluded by this new data and therefore does not believe that these studies have resulted in reduced uncertainty in seismic hazard related to this parameter.
• Considering significant uncertainties in whether the seismic sections presented in the CCCSIP report represent "real geologic structure" and whether the faults shown on those sections represent preferred interpretations, the IPRP is not confident that the tectonic model described as being developed from these surveys is well constrained.
• The newly acquired seismic data may contain valuable new information that bears on the seismic hazard. However the interpretation process that resulted in a single tectonic model is hampered by significant data quality issues (associated in part with the irregular acquisition geometry) and a lack of significant subsurface control (see Ch. 7, page 70). An alternative approach exploring the full range of models allowed by the uncertainties of the data is preferable.
• The IPRP does not see a strong reason to favor the single tectonic model presented in the CCCSIP report over the two alternative models presented by Dr. Thompson at the IPRP meeting on November 17, 2014. CCCSIP Chapter 12: Response to Administrative Law Judge's Decision D.12-09* 008 Regarding Dr. Douglas Hamilton's Concerns The CCCSIP report's Chapter 12 addresses elements of tectonic models of the Irish Hills advanced by Dr. Douglas Hamilton. We focus on the two elements with clear hazard implications: 1) The San Luis Range Fault (SLRF), originally based on the Inferred Offshore Fault (IOF), as a major seismic source, and 2) The Diablo Cove Fault as a surface rupture hazard. In this review we focus on Dr. Hamilton's presentations at SSHAC and IPRP meetings and other references upon which the CCCSIP report is based. At this point we are not commenting on details of his presentation at the IPRP Report No. 8, Page 8 November 17. 2014 IPRP meeting, as this presentation included a preliminary new model for which no documentation has been provided. The model explaining the tectonic uplift of the Irish Hills hypothesized by Dr. Hamilton consists of a low-angle northeast-dipping thrust fault, the SLRF (Figure 6-12). underlying the Irish Hills with a postulated surface trace almost entirely offshore. This inferred fault, would have a length of 60-80 km extending from an intersection with the Hosgri fault, about 8 km south of Point Estero in the north, to the onshore mapped Wilmar Ave fault to the south (Figure 6-21 ). The SLRF proposed by Dr. Hamilton appears to be a variation of the Inferred Offshore Fault of Nitchman and Slemmons (1994), Figure 6-23 in Chapter 12. Along the central portion this inferred fault is coincident with the mapped Shoreline fault. The SLRF is interpreted by Dr. Hamilton to be a thrust fault dipping to the northeast that intersects the Shoreline fault at a depth of 1 to 2 km. He hypothesizes that this is the main structure accommodating regional northeast to southwest compression, which ultimately results in uplift of the Irish Hills. Uplift Boundary and SLRF Location Dr. Hamilton's proposed SLRF and Irish Hills uplift model are based on uplifted landforms, especially the well-documented series of Quaternary marine terraces (Hanson et al, 1994) and the longer term uplift of the Irish Hills block. Nitchman and Slemmons (1994), proposed the IOF to explain the uplift of the Irish Hills as well as the linear range front and coastline. The discovery of the now well-documented Shoreline fault along this section of the coast provides an explanation for the striking linearity of the coastline. Dr. Hamilton's model requires uplift to be localized at the trace of the SLRF, either at or near the surface. Therefore, because the SLRF is co-located along the central portion of the Shoreline fault, it follows that the Shoreline fault should exhibit signs of vertical movement. The series of uplifted coastal terraces provide vertical uplift rates of approximately 0.2 mm/yr, which should be expressed as vertical uplift located on. or in close proximity to the Shoreline fault. The newly acquired multibeam echosounder (MBES) high resolution bathymetry data. however. show no evidence of any vertical fault slip on the Shoreline fault (Chapter 12, Figure 6-28). Hence, along this section of the inferred SLRF, where the highest vertical fault slip rates are predicted as indicated by the uplifted terraces, the Hamilton model is not consistent with observations. Rather, the relatively straight trace and a level marine shelf strongly suggests that the Shoreline fault is a nearly vertical strike-slip fault. Implications of Seismic Imaging on the SLRF Near-surface faults can be found along the length of much of the proposed the SLRF but do not support the model of a major thrust fault. New high-resolution offshore IPRP Report No. 8, Page 9 seismic data from the Point Buchon area. where the proposed SLRF diverges from the Shoreline fault, confirm the existence of faults shown in Figure 6-21. Along the central portion of the Shoreline fault the SLRF is coincident with the Shoreline fault. In San Luis Obispo Bay, seismic reflection data also confirms the existence of near surface faults. These surface fault traces, however, have been explained in existing models that interpret the Shoreline fault as a near vertical strike-slip fault, secondary eastern splays along its northernmost reach off of Point Buchon, and a series of strike-slip and reverse fault crossing San Luis Obispo Bay. Although surface faults recognized to date appear to be consistent with strike-slip faulting on the Shoreline fault, rather than thrusting on the SLRF, the possibility of thrust faults in the subsurface is not ruled out by on-land seismic survey data. The interpretation of the ONSIP data is far from unique and allows one to interpret a low angle reverse fault at the proposed location, contrary to what is stated in the CCCSIP report (p.70 Figure 6-54). The CCCSIP interpretation criteria are not clearly defined and do not appear consistent in terms of selections made when seismic reflections are truncated. Does Seismicity Support the Existence of the SLRF? Seismicity can be correlated with active faults; however, many active faults have little to no seismicity during the interseismic period. Further complicating the matter of using seismicity to characterize faults is the observation that microseismicity often occurs in a large volume surrounding the fault rather than on a localized fault plane. Despite these complications, the Shoreline fault was discovered by Hardebeck (2010, 2013) based on a seismicity trend and later confirmed by MBES surveys. The assertion by Dr. Hamilton that seismicity beneath the Irish Hills shows an alignment that indicates the SLRF location and activity at depth is not confirmed by the more rigorous seismicity analysis performed by Hardebeck (2010, 2013. 2014a. 2014b). Hardebeck has shown convincingly that these data do not allow a unique interpretation and clearly do not strongly favor any Irish Hills uplift model. However, as previously implied, the interpretation of microseismicity has clear limitations in mapping faults and in this case also cannot be used to rule out the existence of the proposed SLRF. Conclusions Although specific details of the Hamilton SLRF Irish Hills uplift model are inconsistent with several observations, the overall model that explains the uplift of the Irish Hills via a northward-dipping fault underlying the Irish Hills is a viable alternative model given the uncertainties in the existing data sets. As presented by Dr. Steve Thompson at the November 17, 2014 IPRP meeting, the SSHAC process is considering an alternative model that includes northeast-dipping thrust faults to explain the uplift of the Irish Hills which largely encompasses the hazard implications of the SLRF model. IPRP Report No. 8, Page 10 Diablo Cove Fault The Diablo Cove fault has been proposed by Dr. Hamilton as presenting a surface rupture hazard to DCPP. The basis for this proposed fault consists of on-and offshore bedrock mapping (Figure 6-3. 6-4. 6-5. 6-8. 6-9.6-10). The mapped faulting has been shown to be discontinuous (Figure 6-6. 6-17, 6-18) and limited in extent. Specifically, there are four locations where faulting was observed during the original DCPP construction between 1966 and 1973 (Figure 6-5, 6-6, 6-9): 1.) In the sea cliff south of the outlet of Diablo Creek (Figure 6-8, 6-10); 2.) In the turbine building foundation excavation; 3.) In the Unit 1 containment structure excavation; and 4.) In a road cut for the switchyard access road east of the DCPP power block. At the turbine building the faulting consists of a zone of faulting extending 70 m in length. Under the Unit 1 containment structure the faulting consists of two discontinuous zones of faulting 10 to 20 m in length. Between these two areas the bedrock was continuously exposed and there is a 50 m-long area where no faulting in the bedrock was observed. Perhaps the most significant exposure of the Diablo Cove fault exists in the sea cliff and was described in detail by Jahns (1966, 67a, 67b). The faulting was observed in thinly bedded sandstone originally classified as Tertiary-age Monterrey Formation (Jahns, 1967b), and later reclassified as Obispo Formation (Hall, 1973). Jahns noted that the fault planes in the sea cliff and on the adjacent modern wave cut platform project eastward north of the DCPP site. Figs. 6-3, and 6-4 show this fault zone to strike N55°-600E with a steep dip to the north. The original investigation by Jahns ( 1966) notes: "None of the faults observed in the mapped area extends upward from the bedrock section into the overlying terrace deposits, nor have any of the wave-cut benches beneath these deposits been offset by such faults. Since the original investigation and additional studies. this key observation has never been disputed. The age of this marine terrace is firmly established at 120 ka by correlation and nearby directly-dated U-series dating with a back edge at an elevation of 30-32 m (Hanson et al, 1994 ). No support for Dr. Hamilton's age assertion of 80-105 ka has been provided. Furthermore Jahns (1967b) reasonably states that the maximum age of faulting is millions of years. The discontinuous, minor faulting, with on the order of a few meters of total offset has been interpreted by the CCCSIP authors as most likely related to contractional deformation and folding (Figure 6-17), and as such could be late Miocene to Pliocene in age (Luyendyk, 1991 ). Dr. Hamilton provides a cross section that extrapolates the Diablo Cove fault to seismogenic depths below 4 km and attempts to correlate the location with m icroseismicity (Figure 6-12 ). No basis for th is correlation can be found, as the IPRP Report No. 8, Page 11 seismicity appears almost randomly distributed and provides little basis for any preferred fault selection. We refer to rigorous microseismicity analyses by Hardebeck (2010. 2013, 2014a, 2014b), who quantifies a wide range of possible fault orientations. The CCCSIP report makes the reasonable point that simple scaling relationships makes it unlikely that these short, discontinuous near-surface faults, with minor meter-scale displacements can reasonably be extended to depths of kilometers, where seismogenic processes occur. Offshore Dr. Hamilton has mapped the Diablo Cove fault extending to the Shoreline fault on the basis of interpreted bedding disruptions observed in the Kelpfly MBES image (Figure 6-4, 6-11 ). The CCCSIP authors appear to have optimized the MBES imagery to assess NW trends of faults (Figure 6-8, 6-9), and they can only identify a possible lineament that does not extend continuously to the Shoreline fault, but rather is cut by a more northerly trending "Headland fault" (Figure 6-18). Conclusions Based on the characterization of the minor faulting activity as older than 120 thousand years and very possibly in the millions-at-years age range, we find that the CCCSIP has reasonably assessed the Diablo Cove fault as not presenting a seismic hazard in terms of surface faulting or increased ground motions at DCPP. IPRP Report No. 8, Page 12 STATE OF CALIFORNIA EDMUND G. BROWN JR .. GOVERNOR Independent Peer Review Panel A 1'1U{;lrv*a1f*e-n,,cy pa-11/e'b of:J*ev,s-*m;w JfJect/a-bvJf:J' l!/J't'a.C-lt/.f*fi,e,d-b-y t'lw/ Ca,,/,Vf'o-rwvw ltt'vbU-U>.,,f* Ct>-1*1vnvt/J-rio-w CALIFORNIA GEOLOGICAL SURVEY, CALIFORNIA COASTAL COMMISSION CALIFORNIA GOVERNOR'S OFFICE OF EMERGENCY SERVICES CALIFORNIA PUBLIC UTILITIES COMMISSION, CALIFORNIA ENERGY COMMISSION CALIFORNIA SEISMIC SAFETY COMMISSION, COUNTY OF SAN LUIS OBISPO IPRP Report No. 6, August 12, 2013 Site shear wave velocity at Diablo Canyon: summary of available data and comments on analysis by PG&E for Diablo Canyon Power Plant seismic hazard studies BACKGROUND In 2006, the California Legislature enacted Assembly Bill (AB) 1632, which was codified as Public Resources Code Section 25303. AB 1632 directed the California Energy Commission (CEC) to assess the potential vulnerability of California's largest baseload power plants, which includes Diablo Canyon Power Plant (DCPP), to a major disruption due to a major seismic event and other issues. In response to AB 1632, in November 2008 the CEC issued its findings and recommendations in its AB 1632 Report, which was part of its 2008 Integrated Energy Policy Report Update. In Pacific Gas and Electric Company's (PG&E) 2007 General Rate Case decision D.07-03-044, the California Public Utilities Commission (CPUC) directed PG&E to address and incorporate the recommendations from the AB 1632 Report into its feasibility study to extend the operating licenses of its Diablo Canyon Units 1 and 2 for an additional 20 years. In November 2009, PG&E submitted its formal application with the Nuclear Regulatory Commission (NRC) to extend the licenses of DCPP Units 1 and 2. In 2010 PG&E filed for cost recovery with the CPUC for expenditures associated with the enhanced seismic studies recommended by the CEC's AB 1632 Report. The motions for cost recovery were subsequently approved in 2010 and 2011. CPUC Decision D.10-08-003. issued on August 16, 2010, established that the CPUC would convene its own Independent Peer Review Panel (IPRP) and invite the CEC, the California Geological Survey (CGS), the California Coastal Commission, and the California Seismic Safety Commission to participate on the panel. Under the auspices of the CPUC, the IPRP is conducting an independent review of PG&E's seismic studies including independently reviewing and commenting on PG&E's study plans and the findings of the studies.

The comprehensiveness. completeness, and timeliness of these studies will be critical to the CPUC's ability to assess the cost-effectiveness of Diablo Canyon's proposed license renewal. As noted in the CEC's AB 1632 Report, a major disruption because of an earthquake or plant aging could result in a shutdown of several months or even cause the retirement of one or more of the plants' reactors. A long-term plant shutdown would have economic, environmental and reliability implications for California ratepayers. In contrast to previous reports of the IPRP, which commented on studies by PG&E to investigate potential earthquake sources near Diablo Canyon, this report focuses on the site amplification factor -an important factor in the calculation of ground motion from any earthquake. The report summarizes data that are available to constrain the site amplification factor and uncertainties in its value, and then provides comments on analyses performed by PG&E using their preferred method of considering that parameter. We chose to focus on site amplification at the Diablo Canyon site because "site conditions" modify earthquake shaking from any earthquake. In sensitivity studies by CGS for the IPRP, site amplification factor has a large effect on calculated seismic shaking potential at DCPP. INTRODUCTION Estimated ground motion hazards can be altered significantly by site conditions, and different methods used to incorporate the effects of site conditions often result in different ground motion estimates. Three approaches have been used in engineering practice to incorporate the effects of site conditions on estimated ground motion hazards: 1. Scaling based on soil classifications, for example, the National Earthquake Hazards Reduction Program (NEHRP) site classifications used in building codes; 2. Using ground motion prediction equations (GMPEs) that incorporate the average shear wave velocity of the uppermost 30 meters of a site (Vs30) as an approximation for site condition; and 3. Site response analyses using near surface site-specific or generic soil profiles. The NEHRP scaling approach is simple, conservative. and often used only for an approximate estimation of design ground motion values. In most modern GMPEs, such as the Next Generation Attenuation (NGA) relations, V530 is treated as an independent variable along with earthquake magnitude, site-to-source distance, etc.; and ground motions for a specific site are calculated by entering the site-specific Vs30 value directly in the GMPEs. For sites with Vs30 values outside the data range that adequately constrains the GMPEs, however, direct use of Vs30 in GMPEs may not be appropriate. In such cases, other methodologies, such as site response analysis, are utilized. PG&E uses a new method to incorporate site effects based on recorded ground motions at Diablo Canyon. A site amplification term has been developed based on ground motion residuals at the site from two locally recorded earthquakes. Uncertainty in site IPRP Report 6, Page 2 amplification is based on the epistemic uncertainty due to systematic differences in the site amplification between sites with the same Vs30 in a single station sigma approach. Compared to traditional approaches, the PG&E method resulted in lower ground motion hazard estimates, particularly in the spectral period range important to DCPP (3.5 to 8 Hz), as reported in the Shoreline Fault Report (SFR) (PG&E 2011 a). The PG&E method is based on state-of-the-art research and is technically sound. However, additional data, clarification, and documentation are required to justify the applicability of the method to the DCPP site. In this memo, we summarize PG&E's determination of the mean site Vs30 value and discuss variability in near surface shear wave velocity (Vs) illustrated in PG&E data. We demonstrate that a lower Vs30 value is more consistent with other soft rock sites in California and is within the range of uncertainty observed at the DCPP site. A lower V830 brings the estimated ground motion hazards beyond the original design level when used in typical, state-of-the-practice seismic hazard analysis using GMPE's. Given the significant effects of site Vs30 value and uncertainty in near surface Vs on ground motion estimation using a traditional approach, we suggest that PG&E present an evaluation on whether the large uncertainty in near surface Vs is captured adequately in their site amplification approach that is based on two historical earthquakes and the single station sigma concept. DCPP SITE Vs30 VALUES PG&E determined that the DCPP power block foundation has a mean Vs30 value of approximately 1,200 m/s, corresponding to a hard-rock site. This mean Vs30 value was determined based on downhole velocity surveys in four deep boreholes (Figure 1) near the power block conducted in 1978 as part of the PG&E Long Term Seismic Program (L TSP) and two velocity profiles measured in 1998 at the Independent Spent Fuel Storage Installation (ISFSI) site as part of the ISFSI site characterization (Figure 2). The ISFSI site is located approximately 400 m away from IPRP Report 6, Page 3 0 *CO 300ft SCALE. Bo11r.g NU ... locOllonw El**aliO<l Stre pla:: a:-.4 borthofo of *he ir .... es:jgslilm.,o; (rt'f"1rGncc I ():t Ta.tie Figure 1. Location of four downhole velocity survey boreholes near the power block (provided by PG&E). / ,' / g:1: Q "" <!< po>1b *

• llu'. *um b11> 1* ,._., Or * * *w1um **ll*hh i, H1 * * **f\"'
• 1lluv1.1I t,*n (Jh Qt:f Onl;* s,u(tclal *:lepos*:S qret1h:r th.l r. 1hour -r ..... , 11*, r l <, hrw*.n j Op.. . r:l:':')tfJ<-:ont-<.fJllu*. ,ti ! Opt:i1: 1 v* v .. :. ***Ul ,, *. 1.. :nu:i.u .. M1.1. **u .. : :l1.1h.1*.** 111cm*.h'" ,,11-. .. lnd M,* *nb.:*1 tut U I Ill I .. .. ,h tnn-,tf>d ... uu.ht1:**.o:' llll:'*h.nn ,,*: Puc:k h-:ld'"'d Figure 2. Location of ISFSI site (provided by PG&E). The two ISFSI boreholes were located in the highlighted area. the power block. Vs30 values were determined to be 1,212 m/s, 1,228 m/s, and 1,215 m/s for the mean 1978 profile near the power block and the two 1998 profiles at the ISFSI site. PG&E noted that the accuracy of the computed Vs30 values for the ISFSI site is a few percent because the digitization of the ISFSI profiles has a limited accuracy of a few percent. The accuracy of the 1978 profile at the power block is not determined. PG&E also noted that the Vs30 value of 1,200 mis is at the power block embedment depth of 32.4 ft (or approximately 10 m) determined by the lower range of the original surface elevation of 85 ft (from mean sea level) minus the power block foundation elevation of 52.6 ft. We note that according to Figure 5-3 in the DCPP LTSP report (PG&E, 1991) (reproduced as Figure 3 in this memorandum), 52.6 ft represents the deepest part of the power block foundation. A considerable portion of the Turbine Building and Containment Structure is located less than 10 m from the surface and the Auxiliary Building is approximately at the level of the down-slope surface (i.e., elevation of 85 ft). A conservative measure would assume that these structures are located on the IPRP Report 6, Page 4

<;;_ Rnad Turt>ine AuilCing --EL_8.5':..0" * . ---*-l 1 --ri.,__; EL o*-o* J EL 61'-0 S:r*.Jc:;.;ro Figure 3. Cross section of DCPP (Figure 5-3 in DCPP LTSP report, PG&E, 1991). The dashed curve is the original ground surface. ground surface. Vs30 for the ground surface would be lower than at 10 m depth. PG&E indicated during meetings with IPRP that soil structure interaction (SSI) analysis is used to estimate ground motions at different elevations (or embedment levels), and the SSI analyses will incorporate a range of site-specific Vs profiles. Sfl*ar Wave Velocity (Ip.a In 1000s) 2 3 4 5 7 8 100 g c [II c i 0 I 80 -*--:. 396 rn/$ !.. ........ .... -. i : 1,219m/s I : 60 >-: : 40 .... 20 *20 ,. *40 -*60 -*SO -*10D -*120 --140 -*160 ..... -180 ..... *200 792 ml* : i *--'l : : ............. . f i 731n1/si l ! : : I ! : ! : i j 1,646 m/s i ! B I ! I i i : I !............. . .... .:. ........ . : 1,..219 m/$ EXPlA'IATION -BMttioleA*2 -*-* Bor.hvl* B *******Bo<ehol*C ----Be>retioleD A*2 ! l 1.7S3m/s t : ! ! : c : ! i ! Figure 4. Shear wave velocity profiles from 1978 downhole velocity surveys (provided by PG&E). IPRP Report 6, Page 5 In response to our request for additional information on the Vs measurements near the power block, PG&E provided the I PRP with its response to an NRC request for additional information (RAI) made in January 1989 (Question 19) that included shear wave measurements in the four deep boreholes drilled in 1978 near the power block (provided by Richard Klimczak via email dated April 22, 2013). Figure 4 shows these Vs profiles. Considerable variability in measured Vs is observed in this figure. For example, at mean sea level (zero elevation), the measured Vs varies from 731 m/s to 1,646 m/s, a range of over 900 m/s, over a depth range of 80 24 m). According to PG&E's calculation (Excel spreadsheet file provided by Richard Klimczak via email dated April 22. 2013). Vs30 values from these four boreholes are 981 mis. 1,646 mis, 764 mis and 1,347 mis. The shear-wave velocity profile from borehole "B", however, does not include any measurement from within 80 feet of the surface, so is not appropriate for use in calculating V530. Excluding borehole "B", the mean is 1,031 mis and standard deviation is 295 mis, but even this mean is probably higher than the actual V530 at the site. Borehole "C" includes no velocity measurements within 15 feet of the surface and Borehole "A-2" includes no velocity measurements within 30 feet of the surface. Considering that near-surface weathered rock is almost always lower in velocity than deeper unweathered rock, both the mean velocity and range of velocities in the upper 10 mare probably overestimates. In its response to the NRC RAI, PG&E developed a mean Vs profile and lower and upper bounds based on the four 1978 boreholes. Previous soil-structure interaction analyses using this range of uncertainty in Vs profiles found a significant effect of uncertainty in near surface Vs on soil-structure interaction. This effect may have been underestimated because of overestimates of Vs at shallow depths in the average profile by PG&E. Considering the three usable measured profiles, A-2, C, and D, the mean value at 10 m is approximately 800 mis, considerably below PG&E's mean of 1200 mis. A mean value at 5 mis problematic because only profiles C and D measured velocities at that depth. If A-2 had the same velocity as Cat a depth of 5 m, consistent with the relative weathering described in the borehole logs. the mean velocity at that depth would be about 650 mis. also below PG&E's mean value of 1000 mis. The lower bound profile also appears to be overestimated at all depths because it approximates the measured velocities in borehole C. With only three profiles, it is unlikely that one of them represents the lowest velocity material underlying the plant. Some of the variability seen in the 1978 data may reflect poor quality of the Vs measurements made 35 years ago. Interpretations of that data, however, appear to include unconservative assumptions of velocity in boreholes where no velocity was recorded in the upper parts of the soil profile. Alternative interpretations suggest overall lower velocity of the rock underlying the plant and greater variability of velocity across the plant footprint. A complete consideration of site conditions across the plant footprint requires additional Vs measurements using modern technology to constrain the uncertainty and yield more reliable site Vs values. PG&E relied on the two newer profiles at the ISFSI site to justify the use of a mean Vs30 value of 1,200 mis because both the ISFSI and the power block are located on the same geologic unit (the Miocene Obispo Formation, which is composed of tuffaceous and diatomaceous sandstone and silty sandstone). Although the Vs30 values derived from the two Vs profiles at the ISFSI site (1,228 m/s and 1,215 mis) are consistent with a Vs30 of 1,200 mis, these two profiles do not give consistent Vs measurements at given depths. Considerable variability exists at some depth ranges (see Figure 5). Vs30 values from these two boreholes would be 993 mis and 1,214 mis, respectively, if calculated IPRP Report 6, Page 6 from the surface instead offrom 10 m depth. While these two measurements support the high velocity measured in borehole Din 1978, they do not help constrain the lower bound or range of velocity at the plant site. Geological formations elsewhere in California that are similar to the formations at the power block and the ISFSI site show considerable variation in Vs30 values. Tertiary sandstone measured in California have an average Vs30 of 555 m/s and Tertiary volcanic rocks have an average Vs30 of 609 mis (Wills and Clahan, 2006). Since the Obispo Formation at the power plant is relatively well indurated sandstone, above average Vs30 values are expected, but 1 ,200 mis is higher than the expected range of values for this type of rock. Additional Vs measurements near the power block would give better assurance that variability in site Vs30 value as well as near surface Vs profile is adequately captured and the values used in hazard analysis are well constrained, particularly because the rock at the DCPP site is both faulted and folded, leading to greater variability. IPRP Report 6, Page 7 0 10 20 -E -..c 30 -35 0 I I I Shear Wave Velocity (m/s) 500 1000 1500

• I I I I '-1 I I I I I I I I I f I I I I t Mean Profile ---Lower Bound --Upper Bound -ISFSl-1 ISFSl-2 -50 2000 Figure 5. Mean shear wave velocity profile and uncertainty from 1978 downhole velocity surveys and the simplified shear wave velocity profiles from ISFSI borings (plotted using data provided by PG&E).

PG&E APPROACH FOR HARD-ROCK SITE EFFECTS PG&E used an indirect approach to account for hard rock effects. The PG&E approach includes: (1) using the NGA relations to calculate median ground motions and associated standard deviations for a generic "firm rock" condition with Vs30 of 760 mis, and (2) using amplification factors derived by Silva (2008) from generic site response analyses for hard-rock sites to adjust the NGA-predicted median (for a Vs30 of 760 mis) to a generic hard-rock condition (Vs30 of 1,200 mis). PG&E stated that the reason it did not use NGAs to calculate ground motion for Vs30 of 1,200 mis is because this Vs30 value is outside of the range of Vs30 that is well constrained by the empirical data used to derive the NGAs. Silva (2008) derived amplification factors relative to a Vs30 of 1, 100 m/s for 64 cases with different velocity profiles, including rock profiles. PG&E chose two of Silva's 64 cases (Cases 61 and 64 with V530 of 760 m/s and 3, 150 mis, respectively) as relevant to the DCPP site based on similarity in kappa (K) values (approximately 0.04 second, PG&E determined that K for the DCPP site is 0.042 second). It was determined from these two cases that the site amplification is close to a linear function with site Vs30. Therefore, the amplification factors from Vs30 of 760 m/s to 1, 100 m/s were used to extrapolate to the DCPP site ( Vs30 of 1,200 mis). The raw values were smoothed and are shown in Figure 6-6 of the SFR (PG&E, 2011a). Values of hard rock amplification factors (a1) are listed in Table 6-5 of SFR. As indicated in the SFR, K of 0.04 second is the justification for using the Silva (2008) generic amplification factors for the DCPP site. However, in the NGA dataset, K of about 0.04 second is found for generic soft-rock sites in California. For hard-rock sites, the K values can be much smaller (0.01 -0.02 second). There is an inconsistency in the DCPP site condition indicated by the site-specific Vs30 value of 1,200 m/s (hard rock) and by the site-specific K value of 0.042 second (soft rock). This inconsistency makes application of the Silva (2008) scaling factors questionable. Furthermore, the K value for the DCPP site isn't well constrained, as discussed in the next section. However, the Silva (2008) scaling factors were used mainly to compute event-corrected ground motion residuals to derive site-specific site amplification terms using the new site amplification approach, as discussed in a later section. KAPPA AND DCPP KAPPA VALUE K is a seismological parameter that reflects the observable high frequency decay of Fourier amplitude spectra in ground-motion recordings. Although the Fourier amplitude spectra of recorded ground motions are usually jagged, their characteristic shapes can be seen more easily when they are plotted on logarithmic scales. Fourier acceleration amplitudes tend to be largest over an intermediate range of frequencies bounded by the corner frequency on the low side and the cutoff frequency on the high side. The corner frequency is shown theoretically (Brune, 1970) to be inversely proportional to the cube IPRP Report 6, Page 8 root of the seismic moment. Therefore, smaller magnitudes have higher corner frequencies and large earthquakes produce greater low-frequency motions than do smaller earthquakes. Anderson and Hough ( 1984) characterized the shape of the spectrum at high frequencies as exponentially decaying, given by: a(f) = A0 exp(-rrKf) for f > fE where fE is a frequency above which the decay is approximately linear on a plot of log amplitude against linear frequency, Ao is Fourier amplitude, which is dependent on source and propagation path, and K controls the rate of amplitude fall-off with frequency. Although K is accepted as a parameter representing the behavior of Fourier spectra at high frequencies, the mechanism causing this observed fall-off is under debate. Hanks (1982) suggested site effects in near-surface materials; Papageorgiou and Aki (1983) prefer a source-dependency (source does not produce high frequencies due to fault nonelasticity); Anderson and Hough (1984) found that K increases with epicentral distance; and Tsai and Chen (2000) suggested a combined effect of source, distance, and site, with the distance being the least significant of the three. To obtain a more meaningful parameter, the distance dependency can be eliminated by extrapolating the K(r) trend to zero epicentral distance (r = 0). The intercept, Ko, is believed to denote the site attenuation a few kilometers immediately beneath the station (Hough et al., 1988). Ko is a commonly applied high-frequency filter parameter. Silva and Darragh (1995) show that near-source attenuation modeled through K mainly influences response spectra content for frequencies greater than about 5-10 Hz. Average Ko value is 0.037 second for western North America and 0.008 second for eastern North America, demonstrating the difference in rock spectral content in eastern and western North America. Houtte et al. (2011) observed predominant influences of superficial layers of soil on Ko. Although small, a source component of Ko is clearly observable. Ko is often calculated from ground motion recordings as the fitted slope of Fourier amplitude spectra. It can also be estimated from site material properties. An alternate approach was used to determine the K value at the DCPP site. PG&E (2011 a) used the stochastic point source model of Boore (2000) with a K value of 0.042 second and stress drop of 120 bars to simulate ground motions of a 2003 M3.4 Deer Canyon earthquake at a hypocentral distance of 7.8 km. Because the resulting response spectrum compares well with the average horizontal spectrum of the free-field recordings at the DCPP from the 2003 M3.4 Deer Canyon earthquake, K value for the DCPP site is said to be 0.042 second. This K value is not well constrained. It is not clear why K isn't calculated by fitting the Fourier spectrum of the recorded motions or estimated from material properties as noted above. IPRP Report 6, Page 9 PG&E APPROACH TO SITE-SPECIFIC AMPLIFICATION In the SFR, PG&E derives site-specific amplification factors based on recorded ground motion data from two earthquakes: the 2003 M6.5 San Simeon earthquake and the 2004 M6.0 Parkfield earthquake. Site-specific amplification factors are derived for each earthquake event through the following procedure: (1) Determine event terms for a suite of frequencies. For each frequency, the event term is the average of residuals event residuals) from recordings within a chosen distance range that approximately centers on the rupture distance at the DCPP site. The event term is meant to remove source-specific effects; (2) GMPEs are used to calculate median ground motions from the earthquake for the DCPP site rupture distance and a Vs30 of 760 mis. The predicted median ground motions are corrected by the event term from step 1 and scaled to a generic free-field site condition with V830 of 1.100 mis (reference V830), representative of surface V830 value at the DCPP site, using Silva (2008) scaling factors; (3) The average median spectra from all GMPEs (from step 2, event term corrected and Vs30 scaled) are compared with the observed free-field ground motion spectrum at the DCPP site and the differences (i.e., event-term corrected residuals) represent specific amplification compared to a generic site with the reference Vs30 value. Finally, site-specific amplification factors are determined as the mean residuals from the two available earthquakes (averaged period by period and smoothed over a period range). The values of the smoothed mean residuals (i.e., site-specific amplification factors, a2, for reference Vs30 of 1, 100 mis) are listed in Table 6-7 of SFR. Because a2 in Table 6-7 of SFR is derived for reference Vs30 of 1, 100 mis (DCPP surface condition), the overall site amplification factor for NGA medians calculated with Vs30 of 760 mis to DCPP surface condition is the sum of a2 in Table 6-7 plus a1 for Vs30 of 1, 100 mis in Table 6-5 of SFR. The overall amplification factor for NGA medians calculated with Vs30 of 760 mis to the DCPP power block foundation is approximated as a2 in Table 6-7 plus a1 for Vs30 of 1.200 m/s in Table 6-7 of SFR. Note that a1 and a2 in these SFR tables are in natural log units. The overall amplification factor in linear units is the exponential of a1+a2 and is reproduced in Figure 6 (solid curve) of this report. IPRP Report 6, Page 10 2 1.8 -1.6 Ill ' E 0 1.4 U) ,.... 0 .. Qj > 1.2 .i Qj 1 ... -... 0 IQ 0.8 I.I. c 0 .B o.6 Qj ... .. 0 u 0.4 0.2 0 0.1 \ --exp(site_amp) \ ---PG&E+ lo ---PG&E-lo ' 1, I ' ', ' --PG&E+ 2o --PG&E-2o ' . \ ' , ' ,, ', \ --NRC average --Silva Generic 1 ', \ \\ ,, \ ____ ,, ' ' , ' -------' , __ ---------10 100 Frequency (Hz) Figure 6. Site-specific amplification relative to Vs30 of 760 m/s and associated uncertainty (reproduced based on presentation by Norm Abrahamson on June 6, 2013). exp(site_amp) is the exponential of PG&E site amplification term and is used to scale GMPE median predictions, and o is standard deviation applied to PG&E site amplification term. The uncertainty in the mean residual value (i.e., epistemic uncertainty in site-specific amplification factor) has a variance of af25(T)/N, where N is number of observations (i.e., earthquake events) and af25(T), termed site-to-site uncertainty in the single station sigma approach, is the variance of the epistemic uncertainty due to systematic differences in the site amplification between sites with the same Vs30 value. as2s(n is calculated as: af25(T) = Ja2(T,M) -affs(T,M) where a2(T, M) is the standard deviation given by GMPEs. It is a function of earthquake magnitude, M, and is often given as discrete values for a series of spectral periods (n. a55(T, M) is single station sigma, representing a reduced standard deviation for single sites. In the SFR, PG&E used a preliminary model for single station sigma derived for the NGA models (BCHydro, 2010): IPRP Report 6, Page 11 a55(T, M) = (0.87 + 0.0037 ln(T))a(T, M) In the SFR, a525(T) is averaged over M6, M6.5, and M7 to capture standard deviation for the magnitudes relevant for the DCPP site. It also is averaged over the five NGA models used for DCPP ground motion hazard studies. N for the DCPP site is listed in the last column in Table 6-7 of the SFR. In the SFR, this epistemic uncertainty on site amplification is combined with ground motion aleatory uncertainty in the ground motion hazard calculation for computational efficiency. PG&E indicated that in future analyses this epistemic uncertainty will be accounted for using the standard logic-tree approach for epistemic uncertainties, and the range of +/-2 standard deviations will be considered. This uncertainty range also is reproduced in Figure 6 of this report for reference. In the single station sigma approach employed in SFR, ground motion hazards are calculated by integrating a lognormal distribution with single station sigma as the standard deviation instead of the standard deviation from GMPEs. NRC REVIEW OF PG&E SITE EFFECTS In its review of PG&E's SFR, the Nuclear Regulatory Commission (NRC, 2012) concluded that PG&E's site-specific Vs30 value of 1,200 mis is reasonable. This conclusion is based on evaluation of the same three velocity profiles used by PG&E. The NRC agreed that using such a high Vs30 value with the NGAs would not be appropriate. The NRC staff considered PG&E's scaling approach for incorporating site effects appropriate. However, it questioned the applicability of the specific scaling factors and developed an independent set of site correction factors based in its independent site response analyses using PG&E's near surface Vs profile. The NRC site correction factors are plotted in Figure 6 (red curve) for comparison. Also plotted in Figure 6 is Silva's (2008) factor (i.e., a1) for scaling from a generic site with Vs30 of 760 m/s to a generic hard rock site with Vs30 of 1,200 m/s. This figure shows that within the period range important to DCPP, the NRC correction factor is similar to the Silva amplification factor for generic hard rock sites, and DCPP site-specific amplification factor is lower than both the NRC and Silva factors for frequency greater than 4 Hz. IPRP Report 6, Page 12 EFFECTS OF SITE AMPLIFICATION FACTORS ON ESTIMATED DCPP GROUND MOTION HAZARDS To demonstrate the significant effect of site amplification on estimated ground motion hazards at the DCPP site, we reproduced PG&E's deterministic ground motions (dashed curves in Figure 7) for the four main fault sources (the Hosgri fault, Los Osos fault, Shoreline fault, and San Luis Bay fault) and then did the same analysis for other site conditions. For dipping faults, the cases with the lowest estimated dip angles were analyzed. Table 1 lists input parameters for these deterministic calculations. These calculations used the same four NGAs used by PG&E: Boore and Atkinson (2008), Campbell and Bozorgnia (2008), Chiou and Youngs (2008), and Abrahamson and Silva (2008). Figure 7 compares PG&E 84th percentile deterministic ground motions (dashed curves) with those from three sensitivity cases (solid curves in Figures 7a, 7b, and 7c). The PG&E 1991 L TSP/SSER 34, the 1977 HE (Hosgri Earthquake) design spectrum, and the frequency range important to DCPP structures (marked by vertical dark grey lines) are plotted for reference. The PG&E calculation uses PG&E site-specific amplification factors derived from ground motion residuals, epistemic uncertainty in specific amplification factors, and single station sigma. The three sensitivity cases are: (i) a generic site with Vs30 of 1,200 m/s (scaled from GM PE-predicted median for Vs30 of 760 mis using Silva scaling factors, single station sigma); (ii) a generic site with Vs30 of 760 mis (GMPE-predicted median without scaling) using single station sigma; and (iii) a generic site with Vs30 of 760 mis (GMPE-predicted median without scaling) using sigma from GMPEs (i.e., ergotic sigma). This figure shows significant effects of site condition Table 1. PG&E selected deterministic earthquake scenarios (modified from Table 6-8 of the Shoreline Fault Report) Rupture Distance (km)2 Fault Source Magnitude1 Dip (0) Sense of slip3 RR up RJB Rx Hosgri 7.1 80 4.9 2.3 4.9 Strike Slip Los Osos 6.8 45 7.6 0.0 9.9 Reverse/Oblique Shoreline 6.5 90 0.6 0.6 0.6 Strike Slip San Luis Bay 6.3 50 1.9 0.0 2.5 Reverse l ,m .. 90 fractlle of the mean charactenst1c magnitude d1stnbut1on for non-linked cases from source characterization logic tree (see Figure 6-17, PG&E, 2011a) 2RJe is closest horizontal distance to the surface projection of the rupture plane, RRup is closest distance to the rupture plane, and Rx is horizontal distance from the top edge of the rupture, measured perpendicular to the fault strike (it is positive over the hanging wall and negative over the footwall) 3DCPP site is on the hanging wall of Hosgri, Los Osos, and San Luis Bay faults. IPRP Report 6, Page 13 on deterministic ground motions. Compared to a generic rock site with Vs30 of 1,200 m/s, the PG&E site-specific amplification factors shift peak spectral response toward lower frequency. They also lead to slightly lower peak spectral response for all four scenarios (Figure 7a). Compared to a generic site with V530 of 760 m/s, the PG&E site specific ground motions are significantly lower, except for frequencies lower than approximately 2 Hz (Figures 7b and 7c). Comparison of these figures also shows that reducing the aleatory uncertainty in ground motion from GMPE sigma to single station sigma reduces predicted ground motion amplitudes across the spectrum (compare the set of solid curves in Figure 7b with that in Figure 7c). These two figures also show that if DCPP site had a Vs30 value of 760 m/s rather than 1,200 m/s, and if the site behaves more like an average site in ground motion amplification, some deterministic spectra would exceed the 1991 LTSP spectrum. 2.5 2.0 -c .2 1.5 ... QJ "ai u 1.0 ... u QJ a. V'l 0.5 0.0 0.1 -Hosgri 1200o_ss -Los Osos 1200 o ss Shoreline 1200 o_ss -San Luis Bay 1200 o_ss ---Hosgri PG&E ---Los Osos PG&E Shoreline PG&E ---San Luis Bay PG&E ---1977 Spectrum -1991 LTSP Spectrum a 1.0 10.0 100.0 Frequency (Hz) Figure 7. Comparison of deterministic ground motion spectra from PG&E for the DCPP site (dashed color curves; using site amplification term, its uncertainty, and single station sigma) with deterministic spectra of three sensitivity cases (solid curves): (i) a generic site with V530 of 1,200 m/s and single station sigma (Figure 7a); (ii) a generic site with Vs30 of 760 m/s and single station sigma (Figure 7b); and (iii) a generic site with V530 of 760 m/s and sigma from GMPEs (ergotic sigma, Figure 7c). The PG&E 1991 LTSP/SSER 34, the 1977 HE (Hosgri Earthquake) design spectrum, and the frequency range important to DCPP (marked by vertical dark grey lines) are also plotted for reference. (Continued) IPRP Report 6, Page 14 2.5 2.0 s s i 1.5 ... <U .., c( 1.0 ti <U Q. VI 0.5 0.0 2.5 2.0 s s i 1.5 ... <U Qi .., 1.0 ti <U a. VI 0.5 0.0 0.1 0.1 -Hosgri 760 o_ss --Los Osos 760 o ss Shoreline 760 o_ss --San Luis Bay 760 o_ss ---Hosgri PG&E ---LosOsos PG&E Shoreline PG&E ---San Luis Bay PG&E ---1977 Spectrum -1991 LTSP Spectrum b 1.0 --Hosgri 760 Ergotic -Los Osos 760 E rgotic Shoreline 760 Ergotic --San Luis Bay760 Ergotic ---Hosgri PG&E ---Los Osos PG&E Shoreline PG&E ---San Luis Bay PG&E ---1977 Spectrum -1991 LTSP Spectrum c 1.0 Figure 7. Continued. IPRP Report 6, Page 15 Frequency (Hz) Frequency (Hz) 10.0 100.0 ' ,, ,, ,, ,, ' , ', ,,,,, 10.0 ', , ___ -. ........... ' *-' -----100.0 We also calculated probabilistic ground motions using PG&E's probabilistic seismic hazard analysis codes provided by Norm Abrahamson. The calculations were based on an input file (also provided by Norm Abrahamson) that contains the input parameters and the full logic tree of the PG&E base case. We made changes to the input files in order to look at the sensitivity of estimated probabilistic ground motion hazards to site amp I ification. Figure 8 compares the total hazard curve that we reproduced using the PG&E base case input file provided by Norm Abrahamson without modification (solid red curve, using site-specific amplification term, a V530 of 1200 mis scaling, and single station sigma) with two sensitivity hazard curves: (i) for a generic site with Vs30 of 760 mis (dashed red curve, no scaling, single station sigma); and (ii) for a generic site with Vs30 of 1,200 mis (solid green curve, Silva scaling factor, single station sigma). This figure, once again, shows significant increase in ground motion hazards when PG&E specific amplification factors are not used and as Vs30 value is decreased from 1200 m/s to 760 mis. 1.E-02 1.E-03 l.E-05 l.E-06 0.1 Total Hazard Curves at 5 Hz ..... .......... .... -PG&E base case (site term) ---Vs30= 760 m/s, sigma_ss ........ ',, Vs30 = 1,200 m/s (generic), sigma_SS ',, ' ', ' ' ' Spectral Acceleration (g) ' ' ' ' ' ' ' ' ' ' ' \ \ ' ' \ \ ' \ \ \ \ \ \ \ \ \ \ \ 10 Figure 8. Comparison of the total hazard curve at 5 Hz obtained from PG&E base case input file provided by Norm Abrahamson (used site-specific amplification factor) with hazard curves for generic sites with Vs30 of 760 m/s (GMPE-predicted median without scaling) and 1,200 m/s (using Silva scaling factors), respectively. Single station sigma is used in all cases. IPRP Report 6, Page 16 Sensitivity analysis for probabilistic hazards was conducted by PG&E (2011 b) to address an IPRP request to test the main targets of the onshore and offshore geophysical studies. Probabilistic hazard sensitivities to individual targets are demonstrated by comparing hazard curves in Figures 2 through 11 of PG&E's response to IPRP (PG&E, 2011 b). Sensitivity of the 5 Hz hazard at 2 g ground motion level for different sensitivity cases are summarized and ranked in a "tornado plot" shown in Figure 12 of PG&E (2011 b ). The tornado plot is reproduced in this memorandum as Figure 9 for reference. The x-axis value is the ratio of 5 Hz hazard at 2 g spectral acceleration to the reference hazard of 10-4 (i.e., the approximate base case hazard for 5 Hz at 2 g spectral acceleration level). This figure shows that probabilistic hazard is most sensitive to Hosgri slip rate. Uncertainty in Hosgri slip rate may lead to calculated ground motion hazard that varies by a factor of nearly 2. Hosgri Slip-Rate Hosgri Dip (.J u (J Shoreline Slip-Rate o 0 Hosgri -San Simeon Step-Over c Los Osos Dip 00 0 Los Osos Sense of Slip 0 0 Hosgri & Shoreline Rupture 0 Los Osos Slip-Rate () () Shoreline Segmentation () () Shoreline Southern End 0 0 0.25 0.5 0. 75 1 1.25 , .5 1. 75 2 Sensitiivity Hazard I 1 E-4 (at 2 g) Figure 9. PG&E Summary of hazard sensitivity showing effect on 5 Hz hazard for a reference hazard level of 104 (after PG&E, 2011b) IPRP Report 6, Page 17 We constructed a similar "tornado plot" (Figure 10) to put the effect of site condition in the same perspective as source parameters studied by PG&E (2011b). In Figure 10, the horizontal axis is the ratio of 5 Hz sensitivity case hazard to base-case hazard at spectral acceleration of 2g. PG&E base case used site-specific amplification term. its uncertainty, and single station sigma. All other cases used unscaled GMPE medians with Vs30 values indicated in the figure. This figure shows that changing site condition from PG&E characterized DCPP site to a generic site with Vs30 of 760 m/s increases the hazard by more than a factor of 3 (compare hazards for PG&E base case and the 760 m/s case). Changing site condition from PG&E base case to a generic site with Vs300f 1000 m/s increases hazard by a factor of 2. V530= 760 m/s GMPEs 1000 m/s GMPEs V530= 1200 m/s GMPEs PG&E Bse Case 0 0 0 0 0 1 2 3 4 Ratio of Sensitivity Hazard vs. Base-Case Hazard at 2 g Figure 10. Sensitivity shown as the ratio of sensitivity case hazard to PG&E base-case hazard for 5 Hz spectral acceleration at 2 g. IPRP Report 6, Page 18 The fragility used for DCPP is based on the spectral acceleration averaged over the frequency band of 3 -8.5 Hz. Figure 11 shows the significant effect of site condition on this ground motion parameter. Also plotted on this figure is the 1988 L TSP hazard curve for comparison. This figure shows that changing site condition from PG&E characterized DCPP site to a generic site with Vs30 of 760 m/s brings the average ground motion over the frequency band of 3-8.5 Hz above the 1988 L TSP curve (PG&E, 1988) for acceleration greater than about 1.5 g (i.e., hazard level of approximately ?x 10-4 or return period of approximately 1,428 years). <: Cl/ ..... cu 1.E-02 1.E-03 1.E-04 c: cu "'C Cl/ x UJ cu => c: c: <( 1.E-05 1.E-06 0 0.5 1 -Single-Station o. 1200 m/s Single-Station o, 760 m/s -1988LTSP 1.5 2 2.5 3 3.5 Spectral Acceleration (g) Figure 11. Comparison of mean hazard curve for 3-8.5 Hz for Vs30 of 760 m/s with PG&E base case and the 1988 LTSP curves. IPRP Report 6, Page 19 4 DISCUSSION AND RECOMMENDATIONS In summary, PG&E determined that the Vs30 value for DCPP Site is 1,200 mis, similar to a hard rock site. Because NGAs are not well constrained for Vs30 greater than approximately 1,000 mis. NGAs were used to calculate median ground motions for a generic "firm rock" site with V530 of 760 mis. Empirical site-specific amplification terms were developed as mean residuals (event corrected) of ground motions recorded at the site from two locally recorded earthquakes. Site-specific amplification terms (relative to V830 of 760 mis) were then used to scale NGA-predicted median ground motions to the DCPP site condition. Uncertainty in site-specific amplification is characterized by station-to-station uncertainty in the single station sigma concept and is combined with single station sigma and integrated in hazard calculations for computational efficiency. In the frequency range important to DCPP, PG&E site-specific amplification factors are significantly lower than scaling factors for generic sites (Silva. 2008). NRC factors derived from site-response analysis for the DCPP site as part of their independent analysis. and conservative factors in current California and building codes for conventional and critical facilities. So far, PG&E has not captured epistemic uncertainty in available approaches for the effect of site conditions on ground motion hazards. At the I PRP meeting on July 11 , 2013, PG&E indicated it would study site amp I ification analytically and make use of its detailed 3D velocity data for the DCPP site. We conclude that PG&E's state-of-the-art approach to site amplification (based on recorded ground motions) and ground motion variability (single station sigma) is reasonable and makes intuitive sense. However, we conclude that further justifications/clarifications to the PG&E approach are necessary, particularly because the PG&E approach gives lower ground motion hazard estimates in the period range important to DCPP compared to other state-of-the-practice approaches used currently in the U.S. National Seismic Hazard Maps and in International and California building codes. PG&E should demonstrate that the low site amplification seen at the DCPP site is due to site effects. not specific to the azimuths and distances traveled by the recorded ground motions at the site from the two earthquakes used. PG&E should also justify the adequacy of using only two earthquakes to characterize site amplification, particularly because these two earthquakes cover only a small range of the azimuths that seismic waves can travel toward the DCPP site. Near surface Vs data at the DCPP site indicate significant variability/uncertainty (Vs30 ranging from 696 mis to 1 ,646 mis). PG&E should evaluate whether and how this specific variability/uncertainty is captured adequately by its approach that quantifies uncertainty in site amplification based on site-to-site uncertainty (not a site specific parameter) in the single station sigma method. IPRP Report 6, Page 20 PG&E's approach in K estimation is different from approaches that are commonly applied. Usually, K is estimated from the Fourier spectra of recorded ground motions or from subsurface material properties. We would appreciate justifications/explanations to the PG&E's approach. In a public meeting held on July 11, 2013, PG&E indicated that they plan to conduct further studies to improve the quantification of site amplification: 1. PG&E will use new data from recently completed on-land exploration geophysics surveys to develop a new model of Vs beneath the plant site. Initial results of surveys presented by PG&E from one profile suggest that this analysis will result in a well-constrained 3-D model of shear-wave velocity beneath the plant. 2. PG&E will analyze broad band ground motion data to rule out path effects in the current site-specific amplification terms. Since data from two earthquakes are not sufficient to demonstrate that the amplification factors include only modifications of the shaking due to site effects, recorded motion from other earthquakes, particularly earthquakes from the south and west, may help rule out path effects in the amplification terms. 3. PG&E will evaluate site amplification using analytical approaches in which seismic waves are propagated through a velocity model. This approach is more typical of state-of-the-practice for critical facilities and will provide a comparison to the ground shaking evaluation using the site-specific amplification factors. The additional studies by PG&E appear to be well conceived to address the uncertainty in site conditions at DCPP. Considering the large effects on seismic hazard results from different estimates of site conditions and different methods in considering site conditions in seismic hazard analysis, the IPRP will be interested in additional briefings by PG&E on the results of their surveys and analyses. REFERENCES Abrahamson, N.A.. and W. Silva, 2008. Summary of the Abrahamson and Silva NGA ground-motion relations, Earlhquake Spectra, v 24, n 1, p 67 -98. Anderson, J. G., and S. E. Hough. 1984, A model for the shape of the Fourier amplitude spectrum of acceleration at high frequencies, Bulletin of Seismological Society of America, v 74, p 1969-1993. BCHydro (2010). Probabilistic Seismic Hazard Analysis, Volume 3: Ground Motion Report, Draft Nov 3, 2010. Boore, D. M., 2000, SMSIM -Fortran programs for simulating ground motions from earthquakes: version 2.0 -a revision of OFR 96-80-A, U.S. Geological Survey OFR 00-509. IPRP Report 6, Page 21 Boore, D.M., and G.M. Atkinson, 2008, Ground-motion predication equations for the average horizontal component of PGA, PGV, and 5%-damped PSA at spectral periods between 0.01 s and 10.0 s, Earthquake Spectra, v 24, n 1, p 99 -138. Campbell, K.W., and Y. Bozorgnia, 2008, NGA ground motion model for the geometric mean horizontal component of PGA, PGV, PGD and 5% damped linear elastic response spectra for periods ranging from 0.01 s to 10.0 s, Earthquake Spectra, v 24. n 1, p 139-172. Chiou. B.S-J .. and R.R. Youngs, 2008. An NGA model for the average horizontal component of peak ground motion and response spectra, Earthquake Spectra, v 24, n 1, p 173-216. Brune, J. N., 1970, Tectonic stress and the spectra of seismic shear waves from earthquakes, Journal of Geophysical Research, v 75, p 4997 -5009. Hanks, T. C., 1982, fmax. Bulletin of the Seismological Society of America, v 72, p 1867 -1879. Hough, S. E., J. G. Anderson, J. Brune, F. Vernon, J. Berger, and J. Fletcher, 1988, Attenuation near Anza, California, Bulletin of the Seismological Society of America, v 78, p 672 -691. Houtte, C.V., S. Drouet, and F. Cotton, 2011, Analysis of the original of K (Kappa) to compute hazard rock to rock adjustment factors for GMPEs, Bulletin of the Seismological Society of America, v 101, n 6, p 2926 -2941. Nuclear Regulatory Commission, 2012, Confirmatory Analysis of Seismic Hazard at the Diablo Canyon Power Plant from the Shoreline Fault Zone, Research Information Letter 12-01. Pacific Gas and Electric Company (PG&E), 2011a. Report on the Analysis of the Shoreline Fault Zone, Central Coastal California, Report to the U.S. Nuclear Regulatory Commission, January. Pacific Gas and Electric Company (PG&E), 2011 b, Response to IPRP Request for Hazard Sensitivity for Targets for the DCPP Geophysical Surveys, August 8. Pacific Gas and Electric Company (PG&E), 1988, Final report of the Diablo Canyon long-term seismic program, U.S. Nuclear Regulatory Commission Docket No. 50-275 and No. 50-323. Pacific Gas and Electric Company (PG&E), 1991 , Addendum to the 1988 Final Report of the Diablo Canyon Long Term Seismic Program, U.S. Nuclear Regulatory Commission Docket No. 50-275 and No. 50-323. February 1991. Papageorgiou, A. S., and K. Aki, 1983, A specific barrier model for the quantitative description of inhomogeneous faulting and the prediction of strong ground motion, Bulletin of the Seismological Society of America, v 73, p 693 -722. Silva. W., 2008. Site Response Simulations for the NGA Project, Pacific Engineering and Analysis, El Cerrito, CA IPRP Report 6, Page 22 Silva, W., and R. B. Darragh, 1995, Engineering characterization of strong ground motion recorded at rock sites, Technical report, Electric Power Research Institute, El Cerrito, California. EPRI Report TR-102262. Tsai, C.-C. P., and K.-C. Chen, 2000, A model for the high-cut process of strong-motion accelerations in terms of distance, magnitude, and site condition: An example from the SMART 1 Array. Lotung, Taiwan, Bulletin of the Seismological Society of America, v 90, p 1535-1542. Wills, C.J .. and K.B. Clahan. 2006, Developing a map of geologically defined condition categories for California, Bulletin of the Seismological Society of America, v 96, n 4A, p 1483 -1501. IPRP Report 6, Page 23 STATE OF CALIFORNIA EDMUND G. BROWN JR., GOVERNOR Independent Peer Review Panel A m/lvU-v-ag-e,,woy pcvfl/e'b of J*e,,t/;*mio Ju;v;'(;l,/yd-¥peoU:vbt/JCJ* try rluY Ccvb£k,,-nva,,, Pu!J-Uo lirvb1:.TV&J* Co-mmt/Jri&w CALIFORNIA GEOLOGICAL SURVEY, CALIFORNIA COASTAL COMMISSION, CALIFORNIA PUBLIC UTILITIES COMMISSION, CALIFORNIA ENERGY COMMISSION, CALIFORNIA SEISMIC SAFETY COMMISSION, COUNTY OF SAN LUIS OBISPO IPRP Report No. 9, March 6, 2015 Comments on PG&E's Central Coastal California Seismic Imaging Project Report part 3: onshore seismic studies intended to reduce the uncertainty in seismic hazard at Diablo Canyon Power Plant BACKGROUND In 2006, the California Legislature enacted Assembly Bill (AB) 1632, which was codified as Public Resources Code Section 25303. AB 1632 directed the California Energy Commission (CEC) to assess the potential vulnerability of California's largest baseload power plants, which includes Diablo Canyon Power Plant (DCPP), to a major disruption due to a major seismic event and other issues. In response to AB 1632, in November 2008 the CEC issued its findings and recommendations in its AB 1632 Report, which was part of its 2008 Integrated Energy Policy Report Update. As noted in the CEC's AB 1632 Report, a major disruption because of an earthquake or plant aging could result in a shutdown of several months or even cause the retirement of one or more of the plants' reactors. A long-term plant shutdown would have economic, environmental and reliability implications for California ratepayers. In Pacific Gas and Electric Company's (PG&E) 2007 General Rate Case decision D.07-03-044, the California Public Utilities Commission (CPUC) directed PG&E to address and incorporate the recommendations from the AB 1632 Report into its feasibility study to extend the operating licenses of its Diablo Canyon Units 1 and 2 for an additional 20 years. In November 2009, PG&E submitted its formal application with the Nuclear Regulatory Commission (NRC) to extend the licenses of DCPP Units 1 and 2. In 2010 PG&E filed for cost recovery with the CPUC for expenditures associated with the enhanced seismic studies recommended by the CEC's AB 1632 Report. The motions for cost recovery were subsequently approved in 2010 and 2011. CPUC Decision D.10-08-003, issued on August 16, 2010, established that the CPUC would convene its own Independent Peer Review Panel (IPRP) and invite the CEC, the California Geological Survey, the California Coastal Commission, and the California Seismic Safety Commission to participate on the panel. Under the auspices of the CPUC, the IPRP is conducting an independent review of PG&E's seismic studies including independently reviewing and commenting on PG&E's study plans and the findings of the studies. The comprehensiveness. completeness. and timeliness of these studies will be critical to the CPUC's ability to assess the cost-effectiveness of Diablo Canyon's proposed license renewal. IPRP reports 7, 8 and this report respond to studies released by PG&E on September 10, 2014. Those studies are referred to collectively as the Central Coastal California Seismic Imaging Project (CCCSIP) report. The CCCSIP report is divided into 14 chapters focused on individual studies intended to help constrain factors that are important to seismic hazard analysis. Due to the large volume of information presented in the CCCSIP report, IPRP's review of the document was divided into three sections. IPRP Report No. 7, issued November 21, 2014, reviewed offshore seismic surveys as presented in chapters 2 and 3 of the CCCSIP report. IPRP Report No. 8, issued December 17, 2014, reviewed onshore seismic surveys and analysis as presented in chapters 7,8,9 and 12 of the CCCSIP report. This IPRP report is the third part of IPRP's review of the CCCSIP report. It includes onshore seismic studies in the immediate area of the DCPP and the hazard parameters that they are designed to study. These studies. Chapters 10, 11. and 13 of the CCCSIP report, were the subject of a public meeting on January 8, 2015. The focus of chapter 10 is on the shear-wave velocity (Vs) of the geologic material beneath DCPP. Following the public meeting on January 8, 2015, the IPRP had a number of additional questions regarding the velocity model described in Chapter 1 O and requested an additional meeting with PG&E. PG&E declined to meet again with IPRP. As a result, this report only covers aspects of those models described in the CCCSIP report and the public meeting. Chapter 11 describes PG&E's evaluation of such "site conditions" and methods to consider "site response amplification" in seismic hazard calculations. Chapter 13 describes hazard sensitivity by comparing response spectra for selected scenario earthquakes with response spectra previously used for DCPP. SUMMARY OF PREVIOUS RECOMMENDATIONS The IPRP previously reviewed DCPP site conditions and PG&E site amplification approaches documented in the Shoreline Fault Report (PG&E, 2011) and documented its findings and recommendations in IPRP Report No. 6. Important findings and recommendations from that report and PG&E responses are summarized briefly in this section to facilitate discussion. In the 2011 Shoreline Fault Report. PG&E estimated the average shear-wave velocity in the upper 30 m (Vs30), commonly used to represent "site conditions", to be 1200 m/s. IPRP Report No. 6 noted that "Vs data at the DCPP site indicate significant variability /uncertainty" and that PG&E's estimates "appear to include unconservative assumptions IPRP Report No. 9, Page 2 of velocity in boreholes". IPRP recommended additional studies to determine the Vs beneath DCPP and the variability of Vs. While the IPRP found the empirical approach used by PG&E to incorporate site-specific amplification reasonable and intuitive, the panel concluded that further justifications/clarifications are necessary. Specifically, IPRP Report No. 6 recommended that PG&E "demonstrate that the low site amplification seen at the DCPP site is due to site effects, not specific to the azimuths and distances traveled by the recorded ground motions at the site from the two earthquakes used" and "justify the adequacy of using only two earthquakes to characterize site amplification". In response, PG&E confirmed in a letter to CPUC (PG&E, 2013) that it would conduct further studies to improve the quantification of site conditions and amplification. These studies would: (1) use new data from on-land exploration geophysics surveys to develop a 30 model of shear wave velocity beneath the plant site; (2) analyze broad band ground motion data and ground motions from small earthquakes to better quantify site-specific amplification terms; and (3) evaluate site amplification using analytical approaches in which seismic waves are propagated through a velocity model. The CCCSIP report addressed the first study as discussed in detail in the remainder of this IPRP report, but not the second and third studies. DCPP SITE SHEAR WAVE VELOCITY AND SITE CONDITIONS Chapter 1 O of the CCCSIP report presents the "CCCSIP DCPP P-and S-Wave Foundation Velocity Report". Background, methods and conclusions of this study were presented at the IPRP meeting on January 8, 2015 by Dr. Daniel O'Connell of Fugro Consultants. The CCCSIP study consisted of new 3D tomographic imaging of the geologic material beneath DCPP to a depth of about 3000 ft. The tomographic imaging used the same seismic survey sources and receivers as the reflection seismic surveys discussed in IPRP Report No. 8 and used the resulting data, combined with gravity data, to estimate p-wave ands-wave velocities in 3-dimensional cells. Velocity estimates were made for 200x200x200 ft cells underneath the Irish Hills and higher resolution 50x50x10 ft cells in the area around DCPP. The presentation by Dr. O'Connell showed some images of the tomographic model of the Irish Hills. These images show some of the same large-scale features of the geology of the Irish Hills as the seismic reflection studies and geologic mapping described in other chapters of the CCCSIP report, including higher-velocity material consistent with uplifted Franciscan Complex bedrock in the northern Irish Hills, velocity material in the central to southern Irish Hills consistent with the Pismo Syncline, and higher-velocity material along the south edge of the Irish Hills consistent with areas where diabase is mapped at the surface or projected into the subsurface. IPRP Report No. 9, Page 3 The high-resolution tomographic model of the area near DCPP presented in the CCCSIP report shows details of the variation in interpreted velocity. Important elements of this detailed model include: relatively low near-surface velocities in areas with remaining natural soil; relatively high near-surface velocities underlying much of the plant itself; highly variable estimates of Vs30; and irregularly shaped subsurface regions interpreted to have high velocity. While each of these features of the tomographic model may represent improved understanding of the "site conditions" at DCPP and may lead to decreased uncertainty in seismic hazard estimates, PG&E has not confirmed the uncertainties in these velocity estimates. Moreover, the CCCSIP report has an extensive discussion of the difficulty of gaining accurate tomographic results at shallow depths, given the constrained receiver locations. Estimates of seismic shaking are commonly calculated for a "firm rock" site condition with a Vs30 of 760 m/s, then adjusted for the Vs30 of the site. In previous evaluations, PG&E estimated a Vs30 of 1200 m/s for DCPP. IPRP Report No. 6 noted that this value did not reflect the values or variability of Vs measured in 1978. The CCCSIP report presents Vs profiles and estimates of Vs30 of 570 mis and 750 mis for two sites adjacent to DCPP. For additional context, the CCCSIP report provides Vs30 estimates ranging from 429 to 479 m/s for five sites in the DCPP area. The CCCSIP report estimates Vs30 of 980 m/s at the basement elevation of the turbine building and 1260 m/s at the basement elevation of the power block. The variation in Vs30 estimated from the tomographic model support the IPRP interpretation of "overall lower velocity of the rock underlying the plant and greater variability in velocity across the plant footprint" relative to PG&E's previous interpretation. Much of this variation in Vs is expected on a site that has been graded. Low velocities are modeled in soil and deeply-weathered rock. Removal of soil and weathered rock in preparing excavations for construction results in higher Vs3o. The tomographic model depicts the expected variability in shear wave velocity. Vs30 of 750 at seismic station ESTA 28 adjacent to the south side of the turbine building and 570 mis at seismic station ESTA 27 north of the turbine building are consistent with removal of soil and weathered rock from these sites. Simply considering the amount of grading, Vs30 values at DCPP can be expected to be lower than 760 mis at the ground surface around the south, west, and north sides of the turbine building and higher on the east and around the power block. Higher values would be expected at foundation levels, where more weathered rock has been removed and higher-velocity rock is at the surface. The IPRP understands that the purpose of the detailed 3-dimensional velocity model is to replace the simple Vs30 index with detailed amplification estimates that take into account of the velocity structure of the rock underlying the plant. For comparison of IPRP Report No. 9, Page 4 ground motion estimates below, the IPRP is using 760 m/s, the approximate value at the ground surface adjacent to the south side of DCPP, in estimating ground motion at DCPP. In addition to the variation in Vs at the surface due to grading, the CCCSIP report suggests that irregularly shaped diabase bodies in the subsurface lead to large variations in seismic velocity. The centers of some regions interpreted to be diabase bodies are estimated to have p-wave velocities of over 5000 mis, nearly double the velocity of the surrounding sedimentary rock. The presentation by Dr. O'Connell showed that the detailed tomographic model includes modeled diabase bodies to a depth of about 1000 feet below DCPP. The high-resolution tomographic model of the DCPP region is dependent on details of seismic data acquisition and processing. Also, as noted above, PG&E has not provided estimates of the uncertainty in velocity estimates included in the model. One way to check the accuracy of the model is to compare it with other measurements of p-and wave velocity in the same area and with expected velocities in similar materials statewide. Chapter 10 of the CCCSIP report provides profiles of modeled Vs with depth at numerous locations. These can be compared with profiles measured at the DCPP in 1978. Previous Vs measurements were provided to the IPRP as described in IPRP Report No. 6. Comparison of Vs profiles from the tomographic model with profiles measured in 1978 shows broadly similar ranges of Vs and variation of Vs with depth. In detail, however, Vs profiles from the tomographic model do not appear to reproduce the variation in Vs with depth in nearby measured profiles. The most prominent feature in previous profiles is the high-velocity zone centered at approximately 50' elevation in profile DDH-C (Figure 1 ). The tomographic model includes a high-velocity zone near this elevation. but not in any of the profiles near the site of profile DDH-C presented on transects B-B' or D-D'. Below the high-velocity zone, profile DDH-C shows lower velocity (731 m/s) but all nearby profiles from the tomographic model show increasing velocity through this zone, reaching velocities of over 1600 m/s in the profile at 1000 ft on transect B-B' (the closest profile to DDH-C presented in the CCCSIP report). Downhole profile DDH-D shows much less variation of Vs with depth than the nearest profile shown in the CCCSIP report. Differences between Vs profiles measured in 1978 and profiles derived from the tomographic model may reflect poor data or poor resolution in the 1978 profiles. If the 1978 downhole velocity surveys represent "ground truth", however, it appears that the tomographic model does not show some shallow high velocity layers up to 50' thick or low velocity layers up to 100' thick. The lack of correspondence between measured Vs profiles and Vs profiles estimated from the tomographic model suggests significant uncertainty remains in estimates of "site conditions" at DCPP. The IPRP cannot IPRP Report No. 9, Page 5 determine if these differences reflect poor data or analysis in one or both measurements of Vs or if both surveys are essentially correct, but have differing levels of spatial resolution. Certainly, the differences between Vs profiles from the tomographic model and previously measured Vs profiles should have been addressed in the CCCSIP report. Vs (m/sec) 500 1000 1500 2000 200 60 GeoTomo Vs model profiles Site East (ft.) North (ft. I Elev. (ft. I B-1000 5709014.5 2275061.3 87.0 40 0 0 <> D* 700 5709256. 7 2275418 7 1170 100 <> <> 1978 Oownhole Vs profiles <> <> I "ol I DOH*C 20 I DDH-D { 0 0 !, 00 -'E <> < c: <> 0 c: 0 <>o 0 B *20 > /'. o0 Cl) .92 w 0 <> . UJ -100 -40 *200 80 2000 4000 6000 8000 Vs (ft/sec) Figure 1. Comparison of measured Vs profiles from 1978 with the nearest profile from the 30 tomographic survey presented in the CCCSIP report. Site B-1000 is closest to downhole profile DDH-C. Site D-700 is closest to profile DDH-D. Profiles from 30 model from CCCSIP report, Chapter 11, Figures B-2 and B-4. IPRP Report No. 9, Page 6 PG&E SITE RESPONSE METHODOLOGY AND SITE AMPLIFICATION CALCULATION The PG&E methodology to account for site response in its CCCSIP report is essentially the same as the methodology documented in the Shoreline Fault Report. However. the CCCSIP methodology incorporated two new developments: (1) the new Vs30 values at the two free field ground motion recording stations and at the foundation levels of the power block and the turbine building, and (2) four new ground motion prediction equations (GMPEs) developed as part of the 2014 updates of the Next Generation Attenuations for Western United States (NGA West2). The new Vs30 values were developed based on the new shear wave velocity data interpreted from the resolution tomographic model. IPRP review of the new Vs30 values is documented in the previous section of this report. Evaluation of NGA West2 GMPEs is beyond the scope of this review. However, we note PG&E indicated in its CCCSIP report that it would conduct a complete evaluation of the NGA West2 GMPEs as part of the Southwestern United States (SWUS) Senior Seismic Hazard Analysis Committee (SSHAC) ground motion studies required by the NRC. We also note the NGA West2 GMPEs were developed via a multidisciplinary, multi-year research program coordinated by the Pacific Earthquake Engineering Research Center (PEER) (Bozorgnia et al., 2014) and have been adopted in the 2014 updates of the National Seismic Hazard Maps (Petersen et al., 2014). The incorporation of these new developments necessitated recalculation of site amplification parameters. The PG&E methodology consists of two components: (1) an empirical site-specific site term that accounts for differences in observed ground motions at the DCPP site and an average site depicted by the GMPEs for a reference site condition. and (2) a site amplification term that accounts for differences between sites with different Vs30 values reflecting differences in shallow Vs profiles. We refer to these two terms as site-specific term and Vs30 scaling term. respectively. In the CCCSIP report, recording station ESTA28 (Vs30 = 753 mis, approximated as 750 m/s) was selected to be the reference free field site. Ground motions recorded at station ESTA27 (Vs30 = 570 m/s) were adjusted to the reference site condition. Following the procedure described in the Shoreline Fault Report, a site-specific term at each frequency is determined as the mean residuals from the two available earthquakes (averaged period by period and smoothed over a period range) and uncertainty is estimated based on station-to-station variability from a worldwide dataset and number of available earthquakes recorded at the DCPP (2 earthquakes). The values of the smoothed mean residuals (i.e., site specific term for reference Vs30 of 760 m/s) and uncertainty range are listed in Table 3-1 and illustrated in Figure 3-4, Chapter 11 of the CCCSIP report. IPRP Report No. 9, Page 7 In the Shoreline Fault Report, scaling of ground motions for sites with different Vs 30 values was based on the site response analysis results of Silva (2008). In the CCCSIP report, PG&E scaled ground motions at the reference site ( Vs30 = 760 mis) to the power block foundation (Vs30 = 1260 mis, approximated as 1200 mis) using scaling factors derived from site response analysis carried out by the NRC (2012) using a DCPP shear wave velocity profile with Vs30 of 1200 mis. In applying the NRC scaling factors, PG&E made additional corrections to account for difference in basin depth according to the studies of Kamai et al. (2013). Scaling factors from the reference site to the turbine building were interpolated from scaling factors from the reference site to the power block. Amplification factors for Vs30 scaling (i.e., Vs30 scaling term) are listed in Table 3-2 for the foundations at the power block and turbine building and are illustrated in Figure 3-5 (for power block foundation) in Chapter 11 of the CCCSIP report. The total site-specific amplification factor (in natural log scale) for each site with respect to the NGA West2 predictions for a reference rock site of Vs30 = 760 mis is the sum of the site specific term (Table 3-1 in Chapter 11 of the CCCSIP report) and the Vs30 scaling term for that site (Table 3-2 in Chapter 11 of the CCCSIP report). The total 2 1.8 -1.6 Ill -E 1.4 " 0 .. Cll 1.2 .i? 1;j a; 1 ... -... 0 ti ::!. 0.8 c .2 t: 0.6 Cll ... ... 0 v 0.4 0.2 0 0.1 \ \ ' 1, I \ -SiteAmp-CCCSIP * * * *

• Upper Range -CCCSIP * * * *
• Lower Range
• CCCS IP --exp(site_amp)-SFR ---SFR +lo ---SFR -lo ', :** .. ' ' : A **.,\ .. **' .. , ' ., . .._.,, ' :, ' . ' :, \: \: \ \: -SFR +20 --SFR -2o '* --... __ ,, ' ... " ., ..... ----........ \ ' '"" ... , ...... ,,,,.,. ' . \ .. . _..,. _______ _,-:.* . . ** ............. \ '1 ---.-;. ** ** ... **************** 1 10 100 Frequency (Hz) Figure 2. Comparison of site-specific amplification factors (in linear units) and associated uncertainty in the CCCSIP report and the Shoreline Fault Report (SFR) (plotted according data presented in the CCCSIP report, SFR, and presentation by Norm Abrahamson on June 6, 2013, a is standard deviation). IPRP Report No. 9, Page 8 amplification factors for the foundation levels at the power block and the turbine building are listed in Table 3-3, Chapter 11 of the CCCSIP report. Figure 2 compares updated site amplification factors and associated uncertainties in the CCCSIP report with those used in the Shoreline Fault Report. In general, the new factors are slightly lower. However, given large uncertainty in site amplification, the difference should be considered insignificant. HAZARD SENSITIVITY AND IMPACT Impact of the updated fault source and site amplification parameters on ground motion hazards at the DCPP site was evaluated using a simple, deterministic approach in Chapter 13 of the CCCSIP report. Changes in source parameters that have potential impact in estimated ground motion hazards include: increase in Shoreline Fault length (from 23 km to 45 km); coseismic rupture of the Shoreline, Hosgri, and San Simeon Faults with a potential magnitude of 7.3; the longer trace, shallower dip for the Hosgri Fault; coseismic rupture of the Hosgri and San Simeon Faults with a potential magnitude of 7. 3; and increase in the minim um dip angle for the Los Osos Fa ult (by 10 degrees). There is no change to the San Luis Bay Fault. Figure 3 compares deterministic ground motion spectra presented in the CCCSIP report (for the turbine building foundation level, Vs30 = 980 m/s, solid curves) and the Shoreline Fault Report (for the DCPP site with Vs30 = 1200 mis, dashed curves) for the four most important fault sources affecting the DCPP site. The PG&E 1991 L TSP/SSER 34, the 1977 HE (Hosgri Earthquake) design spectrum, and the frequency range important to DCPP structures (marked by vertical dark grey lines) are plotted for reference. Although the CCCSIP updates resulted in different ground motions for individual scenarios, there is little difference in estimated ground motion portrayed by the four scenarios as a group. Ground motion is higher for the linked Hosgri and San Simeon M7.3 scenario compared to the SFR Hosgri M7.1 scenario, except at frequency lower than 1 Hz. The updated Los Osos MS.7 scenario resulted in lower ground motions across the spectrum due to combined effects of the new GMPEs, slightly lower site amplification factors, and steeper minimum dip angle. For the Shoreline and San Luis Bay Fault scenarios, slightly lower ground motions were predicted by the CCCSIP updates for frequency range of 3 to 1 O Hz. All scenario spectra fall below the 1991 L TSP and the 1977 HE design spectra. For each earthquake scenario, the CCCSIP deterministic spectrum for the power block foundation level (Vs30 = 1200 m/s) is slightly lower than the CCCSIP spectra for the turbine building foundation level shown in Figure 3 due to higher Vs30 value at the power block foundation level. To illustrate important aspects of seismic hazard evaluation at the DCPP site, Norm Abrahamson presented an updated "tornado plot" at the January 8, 2015 IPRP meeting. The updated tornado plot is re-produced as Figure 4 in this report to facilitate IPRP Report No. 9, Page 9 2.5 2.0 0.5 0.0 0.1 Comparison of CCCSIP and SFR Spectra --Linked Hosgri7.3_ TB_CCCSIP --Los Osos6. 7 _TB_ CCCSIP Shoreline6.7 _ TB_CCCSIP --San Luis Bay6.4_TB_CCCSIP ---Hosgri7 .l_SFR ---Los Osos6.8_SFR Shoreline6.S_SFR ---San Luis Bay6.3_SFR ---1977 Spectrum --1991 LTSP Spectrum 1.0 10.0 Frequency (Hz) 100.0 Figure 3. Comparison of deterministic ground motion spectra from the CCCSIP update for the turbine building foundation level (Vs30 = 980 m/s, solid curves) and from the Shoreline Fault Report for the DCPP site (Vs30 = 1,200 m/s, dashed curves). The PG&E 1991LTSP/SSER34, the 1977 HE (Hosgri Earthquake) design spectrum, and the frequency range important to DCPP (bracketed by vertical dark grey lines) are also plotted for reference. discussion. The horizontal axis is the ratio of 5 Hz hazard at 2 g spectral acceleration to the reference hazard of 10-4 annual rate of exceedance (i.e., the approximate base case hazard for 5 Hz at 2 g spectral acceleration at the DCPP site). The vertical axis ranks sensitivity of ground motion hazard to various input parameters. The updated tornado plot illustrates the reduction of uncertainties in some source parameters based on information developed by the AB1632 studies as reported in the CCCSIP. We note that uncertainty reductions shown in the updated tornado plot is based on PG&E's updated PSHA analyses as part of the SSHAC process. IPRP has not reviewed these new calculations and cannot comment on whether the reductions seen on the updated tornado plot are reasonable. The most striking feature of this updated tornado plot is the 6 items related to ground motion calculation on the top of the tornado that have considerably greater uncertainty and hazard sensitivity compared to the source parameters (lower part of the tornado starting from Hosgri slip rate). The IPRP previously recognized the importance of ground motion calculation parameters (including site specific amplification and ground IPRP Report No. 9, Page 10 Hazard Sensitivity 5 Hz, PSA::: 2g Nor--Frgod1c Pa:h . ** . . . ******* Non-Eri;od1c Source . . ... . . *** Mec1an from GMPf: Si1e Amplification 1-------* *---***---.. Sigm;iSS Model Time Deper.dent haza-d Hosgri Slip Rate Hosgri Dip S1ore11ne Shp Rate . :"*. Los Osos Dip . L:.is Ow:. Slip Rate Shoreline and Hos!;ri L*nking . ,. ! 1 0.01 0, , 1(1 ti<i..:arrJ Ralio (not GM rcrtioi SS'-?011 SSC 2014
• GMC ?014
• Non-E*goc1c G\llC Figure 4. "Tornado Plot" ranking sensitivity of ground motion hazards to uncertainty in input parameters (presented by Norm Abrahamson at the January 8, 2015 IPRP public meeting). motion uncertainty or sigma model) and illustrated their importance in ground motion estimation using a "half tornado plot" in IPRP Report No. 6 (Figure 10). Figure 5 further illustrates the significant impact of ground motion sigma model and site amplification on estimated ground motions. The sensitivity cases illustrated in Figure 5 are based on earthquake scenarios and site amplification parameters developed in the CCCSIP report and the NGA West2 GMPEs. The two components of the overall site amplification (i.e., site-specific term and Vs30 scaling) are separated to illustrate their relative importance. Figure 5 compares the CCCSIP deterministic spectra for the turbine building foundation (calculated using the single station sigma assumption, site-specific term, its uncertainty, and scaling from Vs30 of 760 mis to 980 m/s) with two sensitivity cases: (a) an average site with Vs30 of 760 m/s using the ergodic assumption (i.e., a4th percentile ground motion calculated directly using GMPEs); and (b) a DCPP site with Vs30 of 760 mis using the single station sigma assumption, the site-specific term and its uncertainty (i.e., IPRP Report No. 9, Page 11 eliminating the scaling from Vs30 of 760 mis to 980 m/s compared to the CCCSIP spectra). Figure 5a shows that the deterministic spectra calculated based on the ergodic assumption exceed the 1977 HE and the 1991 L TSP spectra for all but one scenarios in the period range important to DCPP, which re-illustrates observations made in the IPRP Report No. 6 and depicted in Figure 7c of that report. Scaling of Vs30 from 760 m/s to 980 m/s decreases deterministic ground motion across the spectrum, except for frequencies less than 1 Hz (Figure 5b). Differences between the Vs30 of 760 m/s cases (solid curves) shown in Figures Sa and Sb reflect differences when ergodic assumption is used (Figure Sa) versus when single station sigma with site specific term is used (Figure Sb). For the OCPP site, the use of single station sigma with site-specific term appears to be the key factor that brings the deterministic spectra below the original design spectra. While the single station sigma assumption and especially the site term have a significant effect on hazard, the site term is based on the observations of only two earthquakes. As described in IPRP Report No. 6, the IPRP is not convinced that the "site term" reflects some property of the site that would affect all earthquakes recorded at OCPP. The alternative hypothesis that additional factors related to the particular source or paths of those two earthquakes remains at least as plausible. The CCCSIP report does not include any additional studies to address this issue. The 30 site response analyses proposed by PG&E will not address whether single station sigma model is more reasonable than the ergodic assumption, nor will it reduce uncertainty in the site specific term that is calculated based on two recorded earthquakes. The proposed 30 site response model will address Vs30 scaling and the effect of large variability in Vs30 values at the DCPP site. Figure 6 compares deterministic spectra for the CCCSIP sensitivity scenario assuming linked co-seismic rupture of the Shoreline, Hosgri, and San Simeon Faults (M7.3). It shows that deterministic ground motion increases across the spectrum as magnitude for the Shoreline Fault rupture increases from 6.7 to 7.3. This figure also shows increased ground motion as Vs30 decreases from 1200 mis [at the power block foundation level] to 760 m/s. More significantly, the figure shows, once again, that the most influential factor affecting deterministic ground motion estimates is the single station sigma assumption and the site term. IPRP Report No. 9, Page 12 Comparison of CCCSIP Spectra at Turbine Building with Ergodic Spectra 25 2.0 0.0 0.1 --Hosgri7.3_760_erg --Los Osos6.7_760_erg Shoreline6. 7 _ 760 _erg --San Luis Bay6.4_760_erg ---Linked Hosgri7.3_TB_CCCSIP ---Los Osos6.7_TB_CCCSIP Shoreline6.7 _ TB_CCCSIP ---San Luis Bay6.4_TB_CCCSIP ---1977 Spectrum --1991 l TSP Spect ru rn 1.0 10.0 100.0 Frequency (Hz) Comparison of CCCSIP Spectra at Turbine Building with Single Station a Spectra 2.5 --Hosgri7 .3_760_ss --Los Osos6.7 _760_ss Shoreline6.7 _760_ss --San Luis Bay6.4_760_ss 2.0 ---Linked Hosgri7.3_TB_CCCSIP ---Los0sos6.7_TB_CCCSIP Qj Qj ... 1il a. 11'1 0.5 0.0 0.1 Shoreline6.7 _TB_CCCSIP ---San Luis Bay6.4_TB_CCCSIP ---1977 Spectrum --1991 L TSP Spectrum 1.0 ------10.0 100.0 Frequency (Hz) Figure 5. Comparison of deterministic ground motion spectra from the CCCSIP update for the turbine building foundation level (dashed curves; using single station sigma, site term, site term uncertainty, and scaling from Vs30 of 760 mis to 980 mis) with deterministic spectra of two sensitivity cases: (a) an average site with Vs30 of 760 mis using the ergodic assumption (i.e., calculated from GMPEs directly); and (b) A DCPP site with Vs30 of 760 mis using single station sigma assumption, and site-specific term and its uncertainty. The PG&E 1991 LTSPISSER 34, the 1977 HE (Hosgri Earthquake) design spectrum, and the frequency range important to DCPP (bracketed by vertical dark grey lines) are also plotted for reference. IPRP Report No. 9, Page 13 2.5 2.0 0.5 o.o 0.1 Comparison of Shoreline Spectra --Shoreline7 .3_760_erg --Shoreline? .3_760_ss Shoreline? .3_PB_ss_CCCSIP Sh ore Ii ne6. 7 _ps _SS_ c CCSI p ---1977 Spectrum -1991 LTSPSpectrum 1.0 ,--, I I I , I I I " Frequency (Hz) 10.0 100.0 Figure 6. Comparison of deterministic ground motion spectra for the Shoreline Fault rupture linked with the Hosgri and San Simeon Faults. CONCLUSIONS The CCCSIP report, chapter 10, presents a new high-resolution tomographic model intended to be used to model how seismic waves are modified as they pass through the rocks immediately beneath DCPP. That model shows overall lower Vs and greater variability of Vs than used in the Shoreline Fault Report, as the IPRP anticipated in Report No. 6. Estimates of Vs near the surface approximately reflect the amount of soil and weathered rock removed from the site during grading, as expected. Estimates of Vs30 are 570 m/s and 750 mis at ground level on opposite ends of the turbine building, within the range expected for the type of rock at these locations. Estimates of Vs30 for foundation levels are higher, reflecting removal of more weathered rock. While the estimated Vs values in the tomographic model correspond to expected relationships of Vs with depth, with removal of low-Vs material by grading, and general range of Vs for different geologic units these values do not correspond well to values previously measured in boreholes. PG&E has not reconciled these differences, nor have they provided estimates of uncertainty in the velocity values in the tomographic model. IPRP Report No. 9, Page 14 The PG&E methodology to account for site amplification in the CCCSIP report is essentially the same as in the Shoreline Fault Report. Nevertheless, site amplification factors were updated to incorporate two new developments: the new NGA West2 GMPEs and the updated Vs30 values for the two free field recording stations. The updated site amplification factors are generally lower than those in the Shoreline Fault Report. However, the difference is insignificant given large uncertainty in site amplification. The CCCSIP report states that the new 30 velocity model is to be used in 30 response analysis as part of the SSHAC process. The 30 response analysis may improve the estimate of site amplification from the reference site with Vs30 of 760 mis to the foundation levels of the power block and the turbine building. It could also account for the effect of highly variable Vs30 values at the OCPP site on estimated ground motion. The 30 response analysis cannot, however, address issues associated with the specific term. IPRP previously expressed its concern regarding the adequacy of using only two earthquakes in estimating the site-specific term and made recommendations to gain confidence in the PG&E site-specific approach, including analyzing broad band ground motion data and ground motions from small earthquakes to better quantify the site-specific term. PG&E has not addressed these recommendations. SUMMARY
• The CCCSIP report presents a detailed 30 velocity model that reproduces several expected variations in shear-wave velocity in subsurface, however: o Uncertainties of velocities are not clearly described. o Correspondence with previously measured velocities is poor.
• The single-station sigma approach has significant effects on calculated earthquake shaking. o Calculated ground motions using the 30 tomographic model should reflect uncertainties in that model, which have not been described. o The "site term" based on two recorded earthquakes may represent other factors, rather than site conditions. IPRP is not convinced that this factor is adequately constrained for use in ground motion calculations. IPRP Report No. 9, Page 15 REFERENCES Bozorgnia, Y., Abrahamson, N.A., Al Atik, L., Ancheta, T.D., Atkinson, G.M., Baker, J.W., Baltay, A., Boore, D.M., Campbell, K.W., Chiou, B. S.-J., Darragh, R., Day, S., Donahue, J., Graves, R.W., Gregor, N., Hanks, T., Idriss, l.M., Kamai, R., Kishida. T.. Kottke, A., Mahin, S.A., Rezaeian. S., Rowshandel. B., Seyhan, E .. Shahi, S., Shantz, T., Silva, W., Spudich, P., Stewart, J.P., Watson-Lamprey, J., Wooddell, K., and Youngs, R., 2014, NGA-West2 research project: Earthquake Spectra. v 30, p 973-987. Kamai, R., Abrahamson, N.A., and Silva, W.J., 2013. Nonlinear Horizontal Site Response for the NGA-West2 Project, Pacific Earthquake Engineering Research Center Report PEER 2013/12, May. Nuclear Regulatory Commission, 2012, Confirmatory Analysis of Seismic Hazard at the Diablo Canyon Power Plant from the Shoreline Fault Zone, Research Information Letter 12-01. Pacific Gas and Electric Company (PG&E), 2011, Report on the Analysis of the Shoreline Fault Zone, Central Coastal California, Report to the U.S. Nuclear Regulatory Commission, January. Pacific Gas and Electric Company (PG&E), 2013, PG&E Response to IPRP Report No. 6 Site Shear Wave Velocity at Diablo Canyon: Summary of Available Data and Comments on Analysis by PG&E for Diablo Canyon Power Plant Seismic Hazard Studies, Letter to California Public Utilities Commission, October. Pacific Gas and Electric Company (PG&E), 2014, Central Coastal California Seismic Imaging Project, Report to the California Public Utilities Commission, 3 volumes. 13 chapters, September 2014. Petersen, M.D., Moschetti, M.P., Powers, P.M., Mueller, C.S., Haller, K.M., Frankel, A.O., Zeng, Y .. Rezaeian, S., Harmsen, S.C., Boyd, O.S., Field, N., Chen, R., Rukstales, K.S., Luco, N., Wheeler, R.L., Williams, R.A., and Olsen, A.H., 2014. Documentation for the 2014 Update of the United States National Seismic Hazard Maps, USGS Open-File Report 2014-1091, 243 pp. Silva, W., 2008, Site Response Simulations for the NGA Project, Pacific Engineering and Analysis, El Cerrito, CA. IPRP Report No. 9, Page 16 Rochelle Becker From:Rochelle Becker Sent:l2 May 2015 13:08:44-0700 To:DiFranccsco, Nicholas Cc:Markley, Michael;Plasse, Richard;Wentzel, Michael;Walker, Wayne;Alexander, Ryan;Hipschman, Thomas;Maier, Bill;Li, Yong;Chokshi, Nilesh;Xu, Jim;Manoly, Kamal;P. Y.Chen@nrc.gov;Burke, John;Munson, Clifford;Stirewalt, Gerry;Lupold, Timothy;jstamatakos@swri.org;Lingam, Siva;Millcr, Chris;Dcan, Bill;Holian, Brian;Dapas, Marc;Johnson, Michael;Ake, Jon

Subject:

Written concerns -April 28th, 2015 webcast meeting with PG&E Attachments:IPRP Report No 6-1.pdf, IPRP Report No 8.pdf, IPRP Report No 9-1.pdf, 040315 A4NR Protcst-023.pdf, 051215 Rochelle Beckcr-NRC staff.pdf

Dear Mr DiFrancesco,

Please see attached letter. There are four referenced attachments as pdf files as well. Thank you Rochelle Rochelle Becker, Executive Director Alliance for Nuclear Responsibility PO 1328 San Luis Obispo, CA 93406 WWW .a4nr .On! BEFORE THE PUBLIC UTILITIES COMMISSION OF THE STATE OF CALIFORNIA Application of Pacific Gas and Electric ) Company for Compliance Review of Utility ) Owned Generation Operations, Electric Energy ) Resource Recovery Account Entries, Contract ) Application 15-02-023 (Filed February 27, 2015) Administration, Economic Dispatch of Electric ) Resources, Utility Retained Generation Fuel ) Procurement, and Other Activities for the Period ) January 1 through December 31, 2013. ) (U 39 E) ) ALLIANCE FOR NUCLEAR RESPONSIBILITY'S PROTEST Date: April 3, 2015 JOHN L. GEESMAN DICKSON GEESMAN LLP 1999 Harrison Street, Suite 2000 Oakland, CA 94612 Telephone: (510) 899-4670 Facsimile: (510) 899-4671 E-M ai I: joh n@dicksongeesman.com Attorney for ALLIANCE FOR NUCLEAR RESPONSIBILITY TABLE OF CONTENTS I. INTRODUCTION. 1 II. CHERRY-PEEVEY EMAILS REVEAL POST-FUKUSHIMA PR PLOY. 2 Ill. AB 1632 PROGRAM'S REVIEW SAFEGUARDS WERE BREACHED. 4 IV. PG&E SENT 'FINAL' REPORT TO THE NRC WITH NO IRPR REVIEW. 5 V. PG&E's 2014 'FINAL' REPORT STONEWALLED IPRP 2013 CRITIQUE. 7 VI. DR. BLAKESLEE SPOTLIGHTS PG&E's DECEPTIVE PATTERN. 14 VII. PG&E's POST-CCCSIP CONTEMPTUOUS DISCLOSURE. 16 VIII. TO LIVE OUTSIDE THE LAW YOU MUST BE HONEST. 18 IX. WHY A4NR PROTESTS. 21 APPENDIX A: PG&E SPECTRA CHARTS FROM CCCSIP REPORT A-1 APPENDIX B: PG&E LATE-DISTRIBUTED HAZARD CHART B-1 TABLE OF AUTHORITIES CALIFORNIA STATUTES AB 1632 ...................................................................................................... i, 1, 2, 4, 5, 6, 7, 8, 10, 13, 14, 15, 16, 17, 20 CALIFORNIA PUBLIC UTILITIES COMMISSION RULES Rule 2.6 .......................................................................................................................................................................... 1 CALIFORNIA PUBLIC UTILITIES COMMISSION DECISIONS D.10-08-003 ......................................................................................................................................................... 1, 4, 12 D.12-09-008 ..................................................................................................................................................... 1, 4, 5, 12 D.14-08-032 ................................................................................................................................................................... 1 OTHER AUTHORITIES IPRP Report No. l ........................................................................................................................................................ 12 IPRP Report No. 2 .......................................................................................................................................................... 4 IPRP Report No. 3 ...................................................................................................................................................... 4, 5 IPRP Report No. 6 ........................................................................................................................................ 5, 6, 7, 9, 13 I PRP Report No. 8 ...................................................................................................................................... 10, 11, 12, 16 IPRP Report No. 9 ...................................................................................................................................... 7, 8, 9, 10, 13 ii I. INTRODUCTION. Pursuant to Rule 2.6 of the Rules of Practice and Procedure of the California Public Utilities Commission ("Commission" or "CPUC"), the Alliance for Nuclear Responsibility ("A4NR") files its Protest to a portion of the 2014 Energy Resource Recovery Account Compliance ("ERRA Compliance") application filed by the Pacific Gas and Electric Company ("PG&E"). A4NR objects to PG&E's recovery of certain balances recorded in the Diablo Canyon Seismic Studies Balancing Account ("DCSSBA") for 2014 costs which fail to comply with D.12-09-008 and D.10-08-003 and, consequently, were not reasonably incurred. Additionally, D.14-08-032 directed PG&E to transfer funding for its Long Term Seismic Program ("LTSP"), including the Senior Seismic Hazard Analysis Committee ("SSHAC") process, to the DCSSBA effective January l, 2014, subject to reasonableness review in the ERRA Compliance process.1 A4NR protests recovery of certain LTSP amounts as well. A4NR's Protest focuses on PG&E's continued evasion of the Independent Peer Review Panel ("IPRP") established by the Commission to assist in the oversight of the ratepayer-funded AB 1632 seismic studies. The legal and factual grounds for the 2014 Protest are similar to those cited in A4NR's protest of PG&E's still-pending 2013 ERRA Compliance application, A.14-02-008, broadened to include the LTSP to the extent that non-compliant avoidance of IPRP review has contaminated core assumptions used in PG&E's SSHAC reports. Sadly, the 2013 evidence cited in A4NR's opening and reply briefs in A.14-02-008 has been augmented by increasingly brazen defiance by PG&E of D.12-09-008 and D.10-08-003, as outlined herein. 1 D.14-08-032, OP 29 a. The Commission stated, "We find this disposition to be a reasonable approach to improving oversight of the LTSP costs," (Jd., p. 411) and, "We find this disposition to be a reasonable approach to assure the proper integration of Assembly Bill (AB) 1632 seismic studies with the L TSP and the SSHAC process." (Id., p. 412) 1 II. CHERRY-PEEVEY EMAILS REVEAL POST-FUKUSHIMA PR PLOY. A4NR's Protest coincidentally follows the recent revelation of unreported ex parte communications in 2011 between PG&E Vice President Brian Cherry and Commission President Michael Peevey concerning PG&E's A.10-01-022, which sought ratepayer funding for the relicensing of the Diablo Canyon Nuclear Power Plant ("DCNPP"}. Five days after the Fukushima accident, AU Robert Barnett had taken the A.10-01-022 evidentiary hearing scheduled for April 13, 2011 off calendar. On April 11, 2011-just one month after the Japanese meltdown --PG&E ceremoniously announced it would accelerate completion of the AB 1632 seismic studies and requested the U.S. Nuclear Regulatory Commission ("NRC") "to delay final action on the utility's on-going license renewal application until PG&E submits the findings. "2 That same day, Mr. Cherry and President Peevey had the following exchange:3 From: Cherry, Brian K [6] Sent: Mon 4/11/2011 2:49 PM To: Peevey, Michael R.

Subject:

FW: Diablo Canyon License Renewal Attached is the letter mentioned in the press release. From: Peevey, Michael R. [7] Sent: Monday, April 11, 2011 4:34 PM To: Cherry, Brian K

Subject:

RE: Diablo Canyon License Renewal Very good. Prudent thing to do and should reduce some fears, concerns. 2 "PG&E Commits to Finishing 3-D Seismic Studies Related to Diablo Canyon Before Seeking Final Issuance of Renewed Licenses," news release from PG&E External Communications, April 11, 2011. The release quoted John Conway, Senior Vice President of Energy Supply and Chief Nuclear Officer: "We recognize that many in the public have called for this research to be completed before the NRC renews the plant's licenses," said Conway. "We are being responsive to this concern by seeking to expeditiously complete the 3-D seismic studies and provide those findings to the commission and other interested parties so that they may have added assurance of the plant's seismic integrity. " 3 Accessible at ftp://ftp2.cpuc.ca.gov/PG&E20150130ResponseToA1312012Ruling/2011/04/SB GT&S 0001262.pdf 2 From: Cherry, Brian K [8] Sent: Mon 4/11/2011 4:47 PM To: Peevey, Michael R.

Subject:

RE: Diablo Canyon License Renewal ... and resurrect our application and get it back on track? From: Peevey, Michael R. [mailto:michael.peevey@cpuc.ca.gov) Sent: Monday, April 11, 2011 5:04 PM To: Cherry, Brian K

Subject:

RE: Diablo Canyon License Renewal Yep. I will have Carol talk to Barnett. From: Cherry, Brian K [9] Sent: Mon 4/11/2011 5:05 PM To: Peevey, Michael R.

Subject:

RE: Diablo Canyon License Renewal Thanks. The sooner the better. From: Peevey, Michael R. [10] Sent: Monday, April 11, 2011 5:08 PM To: Cherry, Brian K

Subject:

RE: Diablo Canyon License Renewal May. From: Cherry, Brian K Sent: 4/11/2011 5:09:40 PM To: 'Peevey, Michael R.'(michacl.pccvcy@cpuc.ca.gov) Cc: Bee: Subject RE: Diablo Canyon License Renewal Great. And thanks again. 3 Ill. AB 1632 PROGRAM'S REVIEW SAFEGUARDS WERE BREACHED. A4NR relied upon the establishment of the IPRP by the Commission in D.10-08-003 to ensure that the AB 1632 studies were conducted as robust scientific inquiry and not as a public relations exercise. As AU Barnett made clear in that proceeding: And I say this, and I'll say it on the record, that part of this is because I don't want the Commission to be in a position of just accepting what the utilities tell us without looking at it. We've gotten in that position too many times, and I feel that the way to avoid that problem that we are just taking the utility at its word without the expertise to determine the reasonableness of that. That is why I think the IPRP is valuable, and why they should have an expert witness to review this stuff 4 The protocols for IPRP-PG&E interactions articulated in IPRP Report No. 2, 5 repeated verbatim in IPRP Report No. 3, 6 and reinforced by the admonition in D.12-09-008 ("We expect PG&E to 4 A.10-11-015 Transcript, p. 263. 5 IPRP Report No. 2, September 7, 2011, pp. 8 -9: "The JPRP expects that: *PG&E will provide its study plans and draft completed study findings to the I PRP for review. These include studies summarized in CPUC Decision 10-08-003 including off-shore, on-shore, and ocean bottom studies, and seismic studies recommended in the AB 1632 Report.

• The JPRP, coordinated by the California Geological Survey (CGS}, will review and provide comments on PG&E's study plans. The goal wilf be, if possible, to provide comments within 30 days of receipt.
• The JPRP, coordinated by the CGS, will review and provide comments on PG&E's draft completed study findings to the CPUC. The goal will be to provide comments as promptly as possible.
• PG&E will review and, if possible, within 30 days incorporate the I PR P's recommendations and comments in PG&E's revised study plans and revised completed study findings and prepare for the I PRP a 'Response to Comments' for the IPRP to document scientifically why PG&E accepted or rejected the IPRP's comments.
• PG&E and the JPRP will participate in quarterly meetings/briefings to review the status of PG&E's seismic studies, any changes in the study plans, and any preliminary study findings.
• PG&E and the JPRP will prepare a master schedule incorporating the major milestones for the IPR P's review process and will include these milestones in PG&E's monthly progress reports and schedule to the NRC and the Atomic Safety and Licensing Board.
• The CPUC and CEC will address any major scientific or technical issues that have not been resolved informally between the IPRP and PG&E. CPUC Decision 10-08-003 states that, 'Should a dispute arise it should be resolved informally but if that is not attainable the Commission has authority to halt the associated rate recovery.' In addition, the CEC may report on any seismic issues and updates through its JEPR process. However, we anticipate that any major scientific or technical issue that may arise can be addressed and resolved informally. The quarterly briefings/meetings mentioned above will allow PG&E to report on its progress and help facilitate a productive informal exchange of scientific viewpoints." 4 continue to meet with the IPRP to present and review changes to the seismic study plans, to provide process updates to the IPRP regarding implementation of the studies, and to receive /PRP comments."\ offered at least theoretical protection from the PG&E misconduct which surfaced in 2013 and worsened in 2014. IV. PG&E SENT 'FINAL' REPORT TO THE NRC WITH NO IRPR REVIEW. PG&E submitted what it labeled the "final" AB 1632 report to the NRC on September 10, 2014, six days after the evidentiary hearing in A.14-02-008, and without providing even a draft of the submittal to the IPRP. As the Director of PG&E's Geosciences Department explained at the A.14-02-008 hearing, PG&E had decided that the IPRP was only entitled to receive '1inalized"8 results of the studies after PG&E had issued a '1ina/"9 report to the U.S. Nuclear Regulatory Commission.10 As described in the evidentiary record of A.14-02-008, the extensive criticism of PG&E's ground motion assumptions at the July 11, 2013 IPRP meeting, followed by the eviscerating IPRP Report No. 6, appears to have significantly chilled relations between PG&E and the IPRP. One month after publication of IPRP Report No. 6, PG&E regulatory affairs personnel were complaining to CPUC staff about self-initiated reports by the IPRP and questioning whether the IPRP could be "decommissioned" after submittal of the 'Jina/" report.11 6 IPRP Report No. 3, April 6, 2012, pp. 8 -9. 7 D.12-09-008, p. 16. 8 Richard Klimczak, PG&E, A.14-02-008 Transcript, p. 139, In. 16; p. 141, In. 14. 9 Jd., p. 140, In. 21; p. 141, In. 22.; p. 142, In. 7. 10 Id., p. 140, In. 25. 11 A4NR Opening Brief, A.14-02-008, pp. 27 -29 citing three internal PG&E emails dated September 16, 2013. 5 It had taken more than six months of repeated requests by IPRP chair Chris Wills to obtain PG&E's documentation of its Vs measurements at the OCNPP plant site, and his efforts established that PG&E's Vs assumptions had a 50% greater impact on the seismic hazard calculation than the slip rate on the Hosgri Fault, previously labeled the top uncertainty in the PG&E model. And IPRP Report No. 6 was unsparing in its criticism of PG&E's assumptions:
• To prioritize the main targets of the AB 1632 onshore and offshore geophysical studies, the IPRP earlier asked PG&E for sensitivity analyses of the probabilistic hazards. PG&E's 2011 response ranked uncertainty in the slip rate of the Hosgri Fault as clearly the most significant, with a "calculated ground motion hazard that varies by a factor of nearly 2. "12
• Changing PG&E's base case ground motion characterization of V530 of 1200 m/s to a generic site with a V530 of 760 m/s ("more consistent with other soft rock sites in Califomia"13) "increases the hazard by more than a factor of 3" 14 and changing PG&E's assumed site condition to a generic site with a Vs30 of 1000 m/s "increases hazard by a factor of 2." 15 * "Compared to traditional approaches, the PG&E method resulted in lower ground motion hazard estimates, particularly in the spectral period range important to [Diablo Canyon] ... /1 In contrast, "(a) lower V530 brings the estimated ground motion hazards beyond the original design level when used in typical, state-of-the-practice seismic hazard analysis ... " 16
• The IPRP questioned whether PG&E's approach adequately captured shear wave velocities at different depths beneath the plant: "With only three profiles, it is unlikely that one of them represents the lowest velocity material underlying the plant. Some of the variability seen in the 1978 data may reflect poor quality of the Vs measurements made 35 years ago. Interpretations of that data, however, appear to include unconservative assumptions of velocity in boreholes where no velocity was recorded ... " 17 12 IPRP Report No. 6, p. 17. H Id., p. 3. 14 Id., p. 18. 15 /d. 16 /d., p. 3. 17 Id., p. 6. 6
• Nor was newer data from the ISFSl18 site without problem: "these two profiles do not give consistent Vs measurements at given depths. Considerable variability exists at some depth ranges ... they do not help constrain the lower bound or range of velocity at the plant site." 19 * "A complete consideration of site conditions across the plant footprint requires additional V5 measurements using modern technology to constrain the uncertainty and yield more reliable site V5 values. "20 V. PG&E's 2014 'FINAL' REPORT STONEWALLED IPRP 2013 CRITIQUE. Despite written assurances to the CPUC staff in response to IPRP Report No. 6 that "PG&E understands the scientific findings and will conduct the further studies noted, "21 and internal acknowledgment within PG&E's Geosciences Department that '7he recommended tasks described in the conclusion are reasonable and we plan to address them as part of our own updated site response evaluation,"22 the so-called "final" report submitted to the NRC on September 10, 2014 is willfully unresponsive. As summarized in the IPRP's belated review of the ground motion chapters of the 2014 "final" AB 1632 report:
• IPRP Report No. 6 noted that 'Vs data at the DCPP site indicate significant variability /uncertainty' and that PG&Es estimates "appear to include unconservative assumptions of velocity in boreholes'. IPRP recommended additional studies to determine the V5 beneath DCPP and the variability of V5* 23 (emphasis added) * /PRP Report No. 6 recommended that PG&E 'demonstrate that the low site amplification seen at the DCPP site is due to site effects, not specific to the azimuths and distances traveled by the recorded ground motions at the site from the two earthquakes used' 18 "ISFSI" is an acronym for Independent Spent Fuel Storage Installation. 19 IPRP Report No. 6, pp. 6 -7. 20 Id., p. 6. 21 A4NR Opening Brief, A.14-02-008, p. 30, citing PG&E's October 10, 2013 written response to IPRP Report No. 6. 22 A4NR Opening Brief, A.14-02-008, p. 31, citing September 9, 2013 email from Dr. Norman Abrahamson to Richard Klimczak. 23 IPRP Report No. 9, pp. 2 -3. 7 and 'justify the adequacy of using only two earthquakes to characterize site amplification'. 24 (emphasis added)
• In response, PG&E confirmed in a letter to CPUC (PG&E, 2013) that it would conduct further studies to improve the quantification of site conditions and amplification. These studies would: (1) use new data from on-land exploration geophysics surveys to develop a 30 model of shear wave velocity beneath the plant site; (2) analyze broad band ground motion data and ground motions from small earthquakes to better quantify site-specific amplification terms; and (3) evaluate site amplification using analytical approaches in which seismic waves are propagated through a velocity model. The CCCSIP report addressed the first study as discussed in detail in the remainder of this IPRP report, but not the second and third studies. 25 (emphasis added)
• The high-resolution tomographic model of the area near DCPP presented in the CCCSIP report shows details of the variation in interpreted velocity. Important elements of this detailed model include: relatively low near-surface velocities in areas with remaining natural soil; relatively high near-surface velocities underlying much of the plant itself; highly variable estimates of V530; and irregularly shaped subsurface regions interpreted to have high velocity. 26
• While each of these features of the tomographic model may represent improved understanding of the 'site conditions' at DCPP and may lead to decreased uncertainty in seismic hazard estimates, PG&E has not confirmed the uncertainties in these velocity estimates. Moreover, the CCCSIP report has an extensive discussion of the difficulty of gaining accurate tomographic results at shallow depths, given the constrained receiver locations. 27 (emphasis added)
• Differences between V5 profiles measured in 1978 and profiles derived from the tomographic model may reflect poor data or poor resolution in the 1978 profiles. If the 1978 downhole velocity surveys represent 'ground truth', however, it appears that the tomographic model does not show some shallow high velocity layers up to 50' thick or low velocity layers up to 100' thick. The lack of correspondence between measured Vs 24 Id., p. 3. 2s Id. The "final" AB 1632 Report is also referred to as the "CCCSIP" report, an acronym for Central Coastal California Seismic Imaging Project. 26 /d., p. 4. 27 Id. 8 profiles and Vs profiles estimated from the tomographic model suggests significant uncertainty remains in estimates of "site conditions" at DCPP. 28 (emphasis added)
• The IPRP cannot determine if these differences reflect poor data or analysis in one or both measurements of VS or if both surveys are essentially correct, but have differing levels of spatial resolution. Certainly, the differences between VS profiles from the tomographic model and previouslv measured VS profiles should have been addressed in the CCCSIP report. 29 (emphasis added)
• For the DCPP site, the use of single station sigma with site-specific term appears to be the key factor that brings the deterministic spectra below the original design spectra. 30 (emphasis added)
• While the single station sigma assumption and especially the site term have a significant effect on hazard, the site term is based on the observations of only two earthquakes. 31 As described in IPRP Report No. 6, the IPRP is not convinced that the term' reflects some property of the site that would affect all earthquakes recorded at DCPP. The alternative hypothesis that additional factors related to the particular source or paths of those two earthquakes remains at least as plausible. 32 (emphasis added)
• The CCCSIP report does not include any additional studies to address this issue. The 30 site response analyses proposed by PG&E will not address whether single station sigma model is more reasonable than the ergodic assumption, nor will it reduce uncertainty in the site specific term that is calculated based on two recorded earthquakes. 33 (emphasis added)
• Figure 6 compares deterministic spectra for the CCCS/P sensitivity scenario assuming linked co-seismic rupture of the Shoreline, Hosgri, and San Simeon Faults (M7.3). It shows that deterministic ground motion increases across the spectrum as magnitude for the Shoreline Fault rupture increases from 6. 7 to 7.3. This figure also shows increased ground motion as V530 decreases from 1200 m/s [at the power block foundation level] to 28 Id., p. 5. 29 Id., pp. 5 -6. 30 Id., p. 12. 31 The NRC staff noted this same limitation in its 2012 assessment of PG&E's single-station-sigma adjustment at DCN PP, observing, "Generally a larger number of earthquakes would be needed to develop confidence in the correction factor." RI L 12-01, p. 59. 32 IPRP Report No. 9, p. 12. 33 Id. 9 760 m/s. More significantly, the figure shows, once again, that the most influential factor affecting deterministic ground motion estimates is the single station sigma assumption and the site term. 34 (emphasis added)
• The 30 response analysis cannot, however, address issues associated with the specific term. IPRP previously expressed its concern regarding the adequacy of using only two earthquakes in estimating the site-specific term and made recommendations to gain confidence in the PG&E site-specific approach, including analyzing broad band ground motion data and ground motions from small earthquakes to better quantify the specific term. PG&E has not addressed these recommendations. 35 (emphasis added)
• The "site term" based on two recorded earthquakes may represent other factors, rather than site conditions. IPRP is not convinced that this factor is adequately constrained for use in ground motion calculations.36 (emphasis added) The IPRP, impeded from performing its duties by PG&E's extended embargo from mid-2013 until the AB 1632 report was "finalized" in September 2014, was also critical of certain aspects of PG&E's seismic source characterization when it eventually gained access to the document. IPRP Report No. 8 is particularly pointed in its assessment of PG&E's analysis of onshore faults: 34 Id.
• The IPRP is not convinced that the interpretations of the down-dip extensions of faults are well constrained, even in the case of well-documented surface faults. Similarly, faults interpreted from the seismic sections, but not corroborated by surface mapping, (e.g. faults interpreted between the San Miguelita and Edna faults) are possible, but are by no means unique interpretations of the data. Overall, the IPRP is not convinced that projections of faults beyond the very shallow subsurface represented unique interpretations of the data.37 (emphasis added)}
• Proiections of faults to depth in 'basement' rocks of the Franciscan complex appear to be even more problematic. As discussed at the IPRP meeting on November 17, 2014, the Franciscan complex is known to be a mixture of different rock types pervasively 35 /d., p. 15. 36 /d. 37 IPRP Report No. 8, p. 5. 10 sheared at a variety of scales and is not expected to produce reflectors that are extensive over broad areas. The majority of seismic sections, (e.g. AWD line 150 as presented on Chapter 7, Figure 5-25) show prominent, continuous reflectors at relatively great depths in material that is assumed to be bedrock of the Franciscan complex. 38 (emphasis added)
• Most deep reflectors shown on Figure 5-25, and in many other sections are arranged in groups of concave-upward, gently curved reflectors. These reflectors are interpreted in the CCCSIP report as representing geological structure. The IPRP, however, regards this pattern of concave-upward sets of reflectors as difficult to explain geologically, but not difficult to envision as artifacts from the data processing. If the continuous reflectors in Franciscan complex bedrock are artifacts of data processing, rather than representing geologic structure, then the seismic reflection survevs provide no constraint on the down-dip geometry of faults in the Franciscan Complex. 39 (emphasis added)
• The Los Osos fault, in particular, is entirely within Franciscan Complex rocks from very shallow depths. If the reflection surveys do not show real geologic structure along the down-dip extension of this fault, then dip of the fault remains essentially unconstrained. 40 (emphasis added)
• Since the Franciscan complex is known to be a mixture of different rock types pervasively sheared at a variety of scales, continuous, gently dipping layers are not expected. The overall arrangement of the gently dipping 'reflectors' also raises questions that are not addressed in the report. In several sections, the arrangement of reflectors does not resemble a cross-section of folded or faulted rock. The pattern of concave-upward sets of reflectors seen in many sections does not have an obvious geological explanation, leading the IPRP to question whether they represent real geologic structure.41 (emphasis added}
• Even if all reflectors shown in the seismic sections are images of geologic features, the interpretations of various faults are inconsistent and not unique: 1) In many cases, faults are interpreted based on a series of truncated reflectors, but are shown to pass through other reflectors that are not truncated; 2) In some seismic sections, it appears that additional faults are permitted by the data. It is not clear how the stated interpretation methodology allowed the interpretation team to draw some faults and not others; and 3) Alternate interpretations of the dip of most faults are possible. 42 (emphasis added) 38 Id., p. 6. Jci Id. 40 Id. 41 Id., p. 7. 42 Id., pp. 7 -8. 11
• This concern applies to the dip of the Los Osos fault. Alternate dips, including relatively low-angle dips, of the Los Osos fault appear to be possible through sections 138-149 and 150 as shown on Figures 5-24 and 5-25 of the CCCSIP report. The reduction in uncertainty in seismic hazard depicted on the 'tornado diagram' for dip of the Los Osos fault appears to be based on the CCCSIP report conclusion that the new data precludes low-angle dips. The IPRP does not concur that low-angle dips are precluded by this new data and therefore does not believe that these studies have resulted in reduced uncertainty in seismic hazard related to this parameter. 43(emphasis added)
• Although surface faults recognized to date appear to be consistent with strike-slip faulting on the Shoreline fault, rather than thrusting on the SLRF, the possibility of thrust faults in the subsurface is not ruled out by on-land seismic survey data. The interpretation of the ONSIP data is far from unique and allows one to interpret a low angle reverse fault at the proposed location, contrarv to what is stated in the CCCSIP report (p.70 Figure 6-54}. The CCCSIP interpretation criteria are not clearly defined and do not appear consistent in terms of selections made when seismic reflections are truncated. 44 (emphasis added) IPRP Report No. 8 emphasizes the curtailed nature of its after-the-fact review, 45 and points out that proper evaluation of PG&E's seismic data acquisition and processing would require the retention of outside consulting services-an authority expressly granted to the IPRP by D.10-08-00346 and D.12-09-008,47 and first promised at the IPRP's initial meeting on August 31, 2010, 48 but still unfulfilled as of the date of this Protest. Unsurprisingly, it was the very fear of this predictable IPRP focus on data acquisition and processing that dominated PG&E management's 2013 internal "risk" evaluation of a scenario labeled "IPRP Review": 43 Id., p. 8. 44 Id., p. 10. 45 "IPRP review of the tectonic model is based on the CCCSIP report and presentation. The IPRP has not had time, to review the seismic data processing in detail." IPRP Report No. 8, p. 7. 46 D.10-08-003, p. 11. 47 D.12-09-008, p. 23. 48 IPRP Report No. 1, p. 5. 12 IPRP recommends additional processing of data or interpretations after their review of project results. The project results and conclusions are to be provided to the Independent Peer Review Panel (IPRP) as a condition of authorized CPUC funding for this project. They could recommend additional processing methods be applied or other interpretation techniques be utilized. The IPRP make-up does not have members who are experienced in processing and interpretation, but they could seek an independent review by others. 49 (emphasis added) IPRP Report No. 9 also describes more recent obstruction to its review of PG&E's ground motion assumptions: Following the public meeting on January 8, 2015, the IPRP had a number of additional questions regarding the velocity model described in Chapter 10 and requested an additional meeting with PG&E. PG&E declined to meet again with IPRP. As a result, this report only covers aspects of those models described in the CCCS/P report and the public meeting. 50 (emphasis added) PG&E's successful strategy to circumvent meaningful IPRP review, originally formulated in 2013 and implemented as a reaction to the devastating IPRP Report No. 6, culminated with submittal of a deeply flawed 'Jina/" AB 1632 Report to the NRC in 2014. As of the date of this Protest, A4NR has had insufficient time to determine the degree to which adulterated assumptions from the inadequately reviewed AB 1632 Report have driven the conclusions of the LTSP's recent SSHAC Report. The cynical fashion in which PG&E's recent publicity offensive has invoked the hamstrung IPRP review to promote the rosy conclusions of the SSHAC Report leaves little room for doubt: 49 A4NR Opening Brief, A.14-02-008, p. 4, quoting a March 28, 2013 submittal to PG&E's Executive Project Committee by Ed Halpin, Jeff Summy, and Richard Klimczak. so IPRP Report No. 9, p. 2. 13
• Independent experts also included an evaluation of the advanced seismic studies recently performed near Diablo Canyon, as well as feedback on the research provided from a state-appointed independent peer review panel. 51 (emphasis added}
• Their work also utilized insight gained from the advanced seismic studies recently completed near Diablo Canyon. In addition, input on the advanced seismic studies provided bv the California Public Utilities Commission's Independent Peer Review Panel was considered in the seismic hazard re-evaluation process. 52 (emphasis added} * [Th is] work also included an evaluation of the advanced seismic studies recently performed near Diablo Canyon, as well as feedback on the research provided from a state-appointed independent peer review panel. 53 (emphasis added} VI. DR. BLAKESLEE SPOTLIGHTS PG&E's DECEPTIVE PATTERN. Leave it to the author of AB 1632, Dr. Sam Blakeslee, the former Exxon geophysicist who served as Republican Minority Leader of the California State Assembly, to assess the degree to which the $64.25 million ratepayer-funded seismic studies have been subverted. As Dr. Blakeslee observed in December 3, 2014 testimony to the U.S. Senate Environment and Public Works Committee, over several decades PG&E has discovered more faults in close proximity to the plant, attributed greater capability to the faults which it has acknowledged, yet consistently proclaimed the seismic risk at the plant to be diminishing: "The potential earthquakes affecting the plant have increased with each major study. But what's equally striking is that the shaking 51 "Confirming Diablo Canyon Plant's Safety," Ed Halpin, Lompoc Record, March 14, 2015. 52 "Seismic and tsunami safety a priority for Diablo Canyon," Ed Halpin, San Luis Obispo Tribune, March 19, 2015. sJ "Op/ed: PG&E exec answers critics, says Diablo Canyon is safe, secure," Ed Halpin, Pacific Coast Business Times, March 20, 2015. 14 predicted by PG&E for these increasing threats has systematically decreased as PG&E adopted less and less conservative analytical methodologies ... " 54 Dr. Blakeslee was especially critical of PG&E's debased '1inal" AB 1632 Report: ... in a seeming contradiction, rather than finding that larger or closer faults produce greater shaking and therefore a greater threat, PG&E argues in the Report that ground motion will be lower than the levels previously estimated. In other words, these newly discovered and re-interpreted faults are capable of producing shaking that exceeds the shaking from the Hosgri, yet that shaking threat would be much reduced from prior estimates. Though discussed only in passing in the Report, the reason for this seeming contradiction is quite important when assessing whether or not the plant is safe or whether it is operating within its license conditions. The reason the earthquake threat purportedly went down when new faults were discovered is because the utility adopted significant changes to the methodology utilized for converting earthquakes (which occur at the fault) into ground motion (which occurs at the facility). This new methodology, which is less-conservative than the prior methodology, essentially "de-amplifies" the shaking estimated from any given earthquake relative to the prior methodology used during the licensing process. 55 PG&E's "final" AB 1632 Report artfully avoids an apples-to-apples comparison which would isolate the influence of its continuously evolving ground motion prediction methodology. The charts on pages 13 -15 of the Technical Summary, attached to this Protest as Appendix A, purport to contrast the spectra derived from the AB 1632 studies against the 1977 Hosgri evaluation and the 1991 LTSP analysis. Neglecting to reveal the radically different methods for predicting ground motions between cases has the same power of deception as assembling a financial spreadsheet mixing different vintages of dollars without disclosure. To the extent 54 Written Statement by Sam Blakeslee, Ph.D, to the Senate Committee on Environment and Public Works, December 3, 2014, p. 3. Dr. Blakeslee's complete statement is accessible at http://www. e pw. senate .gov Ip u b Ii c/i nd ex. cf m? Fuse Action= Files. View& Fi leS to re id =4 2 d07 68 2-cad 9-4 9f 4-b bf 1-fc975 7f624c9 55 /d., p. 5. 15 that PG&E intended anyone to rely upon the misrepresentations-by-omission contained in these charts, and such reliance were to occur, the common law uses a certain f-word to describe such conduct. VII. PG&E's POST-CCCSIP CONTEMPTUOUS DISCLOSURE. Having successfully circumvented the IPRP before submitting its "final" report to the NRC, and choosing to absorb the criticism of IPRP Report No. 8 without response, the PG&E Geosciences Department could not resist engaging in its own form of end-zone dance at the January 8, 2015 meeting of the IPRP. With peculiar aplomb, Dr. Norman Abrahamson blithely distributed a new hazard sensitivity chart, attached to this Protest as Appendix B, and acknowledged that the six highest ranked uncertainties (each relating to earthquake-induced ground motions at the plant) had never before been presented to the IPRP. Despite admitting that PG&E's void of site-specific ground motion data dominates Diablo Canyon's probabilistic seismic hazard, Dr. Abrahamson nonchalantly suggested this deficiency be addressed in PG&E's 2025 update. There was no mention of the staggering difference in magnitude between the six newly identified uncertainties and the ones which had been selected for the AB 1632 studies. 56 His unmistakable message: having feasted on a $64.25 million authorization for ratepayer-funded studies, we never addressed the most significant issues or even told you what they were. But now we've run out the clock. Too bad, chumps. 56 Dr. Abrahamson's discussion of the new hazard sensitivity chart runs from 1:51:27 to 2:03:25 in the video of the January 8, 2015 IPRP meeting, accessible at http://youtu.be/hXu vnSgxMU 16 VIII. TO LIVE OUTSIDE THE LAW YOU MUST BE HONEST. The light-handed oversight previously afforded PG&E in the conduct of its AB 1632 studies appears to be a legacy of the Commission's discredited, pre-San Bruno voluntary compliance era. As Executive Director Paul Clanon memorably testified to a California Senate committee, "That can be characterized as 'self-reporting,' but a better way to look at it is creating a safety culture at the utility. "57 He later explained that, in lieu of fines, "a better way to ensure safety is to make sure that a utility sees violations on its own has every incentive to report them. "58 As Mr. Clanon told a post-explosion community meeting in San Bruno, fines might "discourage the utilities to come forward when they see a problem. A utility doesn't want their pipelines to be unsafe. "59 A4NR does not contend that PG&E wants DCNPP to be seismically unsafe. Rather, the accumulated record of PG&E's performance of its AB 1632 seismic studies documents a furtive, thumb-on-the-scale approach designed primarily to quell public apprehension and forestall pressure to close the plant. PG&E has received special dispensation from the NRC since October 12, 2012 to defer application of the Double Design Earthquake ("DOE") standard to the Shoreline Fau It until submittal of the DCN PP SSHAC analysis --despite the N RC' s acknowledgment that "using the DOE as the basis of comparison will most likely result in the Shoreline fault and the Hosgri earthquake being reported as having greater ground motion" 57 "PG&E Hammered Over Safety Issues," San Mateo Times, October 19, 2010. 511 "State's gas pipeline inspections found to lag," San Francisco Chronicle, November 14, 2010. 59 "San Bruno blast victims skeptical of PUC oversight," San Francisco Chronicle, December 8, 2010. 17 than the plant's Safe Shutdown Earthquake. 60 This remarkable prediction was repeated by Dr. Cliff Munson, an NRC seismologist, in testimony to a June 19, 2013 California Energy Commission workshop. 61 The indifference with which California state agencies have, at least publicly, accepted this revelation has been alarming but the financial bottom line is undeniable: significant seismic retrofit requirements seem likely to be required. 62 A4NR does not expect the CPUC to involve itself in questions of the seismic licensing basis of DCNPP or the prudence of the manner in which the NRC has addressed the seismic Ii censi ng basis issue. 63 Instead, A4N R expects the Commission to be d ii igent in its application of traditional ratemaking authority to protect California's economic interest and electricity reliability interest in accurately understanding the seismic challenges facing the plant. The Commission would be derelict in meeting this responsibility by relying exclusively on PG&E's good faith or commitment to scientific objectivity. 50 Letter to Edward D. Halpin from Joseph M. Sebrosky, NRC Senior Project Manager for Plant Licensing Branch IV, Division of Operating Reactor Licensing, Office of Nuclear Reactor Regulation, October 12, 2012, accessible at http://pbadupws.nrc.gov/docs/ML1207 /M L120730106.pdf 61 Lead Commissioner Workshop on California Nuclear Power Plant Issues. Docket No.13-IEP-lJ, June 19, 2013, Transcript. p. 89, accessible at http://www.energy.ca.gov/2013 energypolicy/documents/2013-06-19 workshop/2013-06-19 nuclear workshop tra nscript.pdf 62 The severity of any such requirement is suggested by PG&E's 2012 submittal to the NRC of a 331-page list of DCNPP deviations from the "new plant" criteria Dr. Munson testified will be applied: ""The thing I wont to emphasize is that the hazard evaluations are based on current practices for new reactors." Id., p. 81. PG&E' s 331-page list of deviations is accessible at http://pbadupws.nrc.gov/docs/ML1134/ML11342A238.pdf The Union of Concerned Scientists reported in 2013 that. of the 100 reactors currently operating in the U.S .. the two at Diablo Canyon top the NRC's list as being most likely to experience an earthquake larger than they are designed to withstand, using NRC data to calculate the probability of such an event as more than 10 times greater than the nuclear fleet average. "Seismic Shift: Diablo Canyon Literally and Figuratively on Shaky Ground," Union of Concerned Scientists, November 2013, p. 7, accessible at http://www. u csu sa .o rg/ sites/ d efa ult/files/I ega cy/ assets/ d ocu me nts/ nuclear power Id ia b lo-canyon-ea rthq ua ri sk. p df 18 PG&E is the only NRC power plant licensee in the history of the commercial nuclear power industry to face criminal indictment for safety-related violations by the U.S. Department of Justice. While the 27 safety-related felony counts in PG&E's federal grand jury indictment are focused on the company's gas division, it strains credulity to believe that DCNPP has been somehow immunized from the corporate culture rot that recently prompted Commission President Michael Picker to acknowledge during a California Senate oversight hearing that, "I think there's a very clear case that in some places, the utility did divert dollars that we approved for safety purposes for executive compensation."64 And the obstruction of justice felony count which leads PG&E's federal indictment emphatically addresses management as a whole: "On or about September 10, 2010, and continuing through on or about September 30, 2011, in the Northern District of California, the defendant, PACIFIC GAS AND ELECTRIC COMPANY, did corruptly influence, obstruct, and impede, and did endeavor to influence, obstruct, and impede the due and proper administration of the law under which a pending proceeding was being had before a department and agency of the United States ... "65 (emphasis added) Although perhaps not a matter of familiarity to utility regulators, the term "RAP sheet" is derived from the Federal Bureau of Investigation's Record of Arrests and Prosecutions. Actual conviction is not a prerequisite. A4NR is unaware of any other California electric utility with a RAP sheet. While PG&E is certainly entitled to its day(s) in court to defend itself from the federal charges, its status as a criminal defendant and the nature of its alleged crimes should 64 President Picker's statement is at 36:56 of the video of the March 25, 2015 oversight hearing conducted by the California Senate Committee on Energy, Utilities and Communications, accessible at http://calchannel.granicus.com/Med ia Player.php ?view id= 7&clip id=2682 65 United States of America v. Pacific Gas and Electric Company, United States District Court for the Northern District of California, Case 3:14-cr-00175-THE, Superseding Indictment, July 29, 2014, p. 18. 19 discourage the Commission from extending any presumption of veracity to the representations in PG&E's AB 1632 Report without corroboration by the most rigorous scrutiny. IX. WHY A4NR PROTESTS. Building upon key decisions made and implemented by PG&E in 2013, the utility intensified its efforts in 2014 to subvert what was originally conceived by the Commission as a robust re-evaluation of DCNPP's seismic setting. If PG&E is allowed to recover the costs of such subterfuge, the effect on A4NR and all PG&E customers will be electricity rates rendered both unreasonable and unjust by Commission reward of unmistakable perfidy. The consequences for A4NR members (and others) living in communities near the plant stemming from unknowing acceptance of PG&E's defective seismic analysis could, in some circumstances, be much worse than that -with incalculable financial impact on California. A4NR requests evidentiary hearings and will conduct discovery and sponsor testimony elaborating on the facts contained in this Protest, as well as the extent to which PG&E's LTSP and SSHAC expenditures in 2014 were similarly tainted. Assuming timely responsiveness by PG&E to legitimate discovery requests, A4NR has no objection to the schedule proposed in PG&E' s application. The undersigned will be the A4NR's principal contact in this proceeding, but A4NR also asks that the following two individuals be placed in the "information only" category of the Service List: Rochelle Becker rochel le@a4n r .org 20 David Weisman david@a4nr.org Date: April 3, 2015 21 Respectfully submitted, By: /s/ John L. Geesman JOHN L. GEESMAN DICKSON GEESMAN LLP Attorney for ALLIANCE FOR NUCLEAR RESPONSIBILITY APPENDIX A PG&E SPECTRA CHARTS FROM CCCSIP REPORT A-1
• 1 :i r: .. ;. *J. CJ) -c:: 0 2 1.5 .... Q) Q) (.) (.) <{ 1 u (]) a. CJ) 0.5 1977 HE spectrum 1991 LTSP/SSER34 spectrum Page 13of15 CCCSIP Report Technical Summary PB -Linked Hosgri and San Simeon (M 7.3) PB -Los Osos (M 6.7) PB -San Luis Bay (M 6.4) PB -Shoreline (M 6.7) 1977 HE spectrum extended to 0.5 Hz 0 0.1 10 Frequency (Hz) 100 lhe 84th Pwcenlle Detennlnlstlc Ground Motions ii for Four Fault Scenarios Compared to the 19ll ti ,. Hosgrl Earthquake (HE) and the 1991 L 1SPISSER '= 34 Spectra tor the DCPP Power Block CCCSIP REPORT ;.; ! Figure 1-1 l! u 2 -O'l -c 1.5 .... Q,) 0 <( l'C .... 0 Q,) a. (/) 1 0.5 1977 HE spectrum Page 14ofl5 CCCSIP Report Technical Summary 1991 LTSP/SSER34 spectrum TB* Linked Hosgri and San Simeon (M 7.3) TB
• Los Osos (M 6. 7) TB* San Luis Bay {M 6.4) TB
• Shoreline (M 6. 7) 1977 HE spectrum extended to 0.5 Hz 0 ...._ _____________________________________ --.( 0.1 1 10 100 Frequency {Hz) The 84th Pen:.entle Detennlnlsdc Ground Motions for Four faajt Scenarios COlllpared to the 1977 Hosgri Emttlquake (HE) and the 1991 L TSPISSER 34 Spectra for the DCPP Turbine Buldlng CCCSIP RB'ORT Figure 1-2 ..

.9 c 0 2 1977 HE spectrum 1991 LTSP/SSER34 spectrum Page 15of15 CCCSIP Report Technical Summary PB -Shoreline Linked to Hosgri & San Simeon (M 7.3) TB -Shoreline Linked to Hosgri & San Simeon (M 7.3) 1977 HE spectrum extended to 0.5 Hz ..... CV a; a. CJ) 0.5 0.1 10 Frequency (Hz) 100 lhe Nth Pwcentle Detenoinistic Ground llotions for Joint Shorelne and Hosgd-San Slllleoo Fault Rupblre Cotnpared to the 19n Ho$ild Earthquake and the 1991 L lSPJSSER 34 Spectra for the DCPP PoMr Block and T..t>lne Buldln9s CCCSIP REPORT Padlic Ga *d Bldlic C-.-y Figure 1-3 . . APPENDIX B PG&E LATE-DISTRIBUTED HAZARD CHART B-1 Hazard Sensitivity 5 Hz, PSA = 2g Non-Ergodic Path -+-----*:--+-----------+-Non-Ergodic Source -+------__. _ Median from GMPE Site Amplification _,__ ............. SigmaSS Model -+--------+-___...---------r---*-Time Dependent hazard -+--------+-----Hosgri Slip Rate -i--------1----:::-_...---+-__.-----1 Hosgri Dip -+-------1----___.=..,..'-'-.,..,._--+-=----1 Shoreline Slip Rate Hosgri -San Simeon Step Over Los Osos Dip ............... Los Osos Slip Rate -+-------+-----**+ .. -+-. ------1 -Shoreline and Hosgri Linking ----.-----1 Los Osos Sense of Slip -**------+-------dJ Shoreline Segmentation .... ..:dJ Shoreline Southern End ....... * "-" 0.01 0.1 1 10 Hazard Ratio (not GM ratio) :..J SSC 2011 ., SSC 2014 /;},. GMC 2014 + Non-Ergodic GMC ALLIANCE FOR NUCLEAR RESPONSIBILITY May 12, 2015 Nicholas DiFrancesco Office of Nuclear Reactor Regulation njd2@nrc.gov PO Box 1328 San Luis Obispo, CA 93406 (858) 337-2703 (805) 704-1810 www.a4nr.org transmitted via email Re: April 28, 2015 WEBCAST PUBLIC MEETING TO DISCUSS THE SEISMIC HAZARD REEVAUATION RESPONSE BY PACIFIC GAS AND ELECTRIC COMPANY RELATED TO THE FUKUSHIMA DAl-ICHI NUCLEAR POWER PLANT ACCIDENT Dockets Nos. 05000275 and 05000323

Dear Mr. DiFrancesco:

I regret that schedule conflicts prevented the Alliance for Nuclear Responsibility ("A4NR") from participating in the April 28, 2015 public meeting. Having reviewed the archived video webcast and the reporting of the meeting in the San Luis Obispo Tribune ("NRC reaffirms Diablo Canyon's seismic safety," April 28, 2015). I am submitting the following written concerns pursuant to NRC guidelines for Category 1 public meetings. I firmly hope that the NRC staff will painstakingly review each of the focused criticisms in the attached three formal reports from the California Public Utilities Commission's Independent Peer Review Panel ("IPRP"). The IPRP, chaired by the California Geological Survey, was established to review PG&E's performance of the ratepayer-funded AB 1632 Seismic Studies. As explained in the attached A4NR Protest summarizing the IPRP's most pointed concerns, PG&E has largely evaded such review -but not before being called out by the IPRP for exceptionally dubious modeling assumptions concerning the soil conditions beneath the plant and the sparseness of relevant site-specific data to support its application of GMPEs. I was pleased to see some interest in this area by NRC staff on the webcast, but the ease with which the NRC staff and its consultants have previously been taken in by PG&E bluster (e.g., is there no chagrin over how quickly the AB 1632 data shredded PG&E's reduced length, no-joint-rupture dogma about the Shoreline Fault which had been embraced by RIL-12-01 just months earlier?) does not inspire confidence. PG&E's self-assurance in its ability to repeat this hat-trick with the NRC staff is manifest in its abandonment of a regulatory commitment to perform the expedited interim seismic evaluation otherwise required by its March 12, 2015 submittal. The Union of Concerned Scientists reported in 2013 that, of the 100 reactors then operating in the U.S., the two at Diablo Canyon top the NRC's list as being most likely to experience an earthquake larger than they are designed to withstand, using NRC data to calculate the probability of such an event as more than 10 times greater than the nuclear fleet average. PG&E is also the only NRC power plant licensee in the history of the commercial nuclear power industry to face criminal prosecution for safety-related violations by the U.S. Department of Justice. While 27 of those felony counts relate to the company's gas division, the obstruction of justice count which leads the indictment is emphatically company-wide, alleging that management: "did corruptly influence, obstruct, and impede, and did endeavor to influence, obstruct, and impede the due and proper administration of the law under which a pending proceeding was being had before a department and agency of the United States ... " Those two considerations argue for a heightened level of diligence by the NRC staff in reviewing PG&E's March 12, 2015 submittal. PG&E's braggadocio at the April 28, 2015 public meeting about reducing its Core Damage Frequency estimates from 3.7 down to 2 in the 3-8.5 Hz range carries a whiff of Bernie Madoff. The NRC staff needs to carefully address, point by point, each of the IPRP criticisms (among others) before it can begin to dislodge the rubberstamp image it suffers among many Californians. Sincerely, /s/ Rochelle Becker Executive Director Roche I le@a4n r .org cc: M ieha el.Ma rkley@nre.gov; Rieha rd.PI a sse@nre.gov; M iehael. Wentzel@nre.gov; Wayne.Walker@nre.gov; Ryan.Alexander@nre.gov; Thomas.Hipsehman@nre.gov; Bi 11.Maier@nre.gov; Jon .Ake@nre.gov .; Yong. Li@nre.gov; Ni lesh. Choksh i@nre.gov; Jim .Xu@nre.gov; Kam a I. Ma noly@nre.gov; P .Y.Chen@nre.gov; John. Bu rke@nre.gov; Clifford.Munson@nrc.gov; Gerry.Stirewalt@nrc.gov; Timothy.Lupold@nre.gov; jstamatakos@swri.org; Chris.Miller@nrc.govi Bill.Dean@nre.gov Brian. Holi a n@nre.gov; Marc. Da pas@nre.gov; Michael .Johnso n@nre.gov Attachments: IPRP Reports 6, 8, and 9; A4NR A.15-02-023 Protest, April 3, 2015 Sent:27 Mar 2015 16:5 I :57 +0000 To:Jackson, Diane;Munson, Clifford;Ake, Jon Cc:Hill, Brittain;Shams, Mohamed;Vega, Frankie

Subject:

Inquiry for Comment: Windows for WUS Public Meetings and Draft Agenda Cliff, Jon, Diane, Any thoughts on windows for the WUS public meetings? I need to forecast a guess to R-IV and licensee stakeholders. Working to manage expectations. Also, is an outline of a potential agenda for Diablo. I plan to discuss with licensee and R-IV next week and notice around April 2. Proposal for enhancement Diablo Canyon -April 28 Columbia -mid-May Palo Verde -early June Agenda Diablo Agenda 1. NRC a. General Background on 2.1 Seismic b. Technical discussion on goals and expected outcome c. Intro of seismic hazard PSHA methods and use for licensing of new plants I SSH AC 2. Licensee a. SSHAC effort b. Sources, c. GMM d. Technical Issues e. Discussions f. Interim Actions 3. Break [to discuss] 4. NRC a. Discussion of Interim actions and approach b. Technical wrap-up-next steps c. Public Questions Regards, Nick Project Manager -Seismic Walkdowns and Re-evaluations U.S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Japan Lesson Learned Project Directorate n icho las.difrancesco@nre.gov I Tel: (301} 415-1115 Wyman, Stephen From:Wyman, Stephen Sent: 17 Mar 2015 19:52: 17 +0000 To:Singal, Balwant Subjeet:Palo Verde FSAR Balwant, Can you please confirm for me the latest Rev of the FSAR for Palo Verde? I currently find Rev 16 dated June 2011 on the network. (Y:/CDIMAGES/FSAR) The staff has a question regarding their seismic design basis as it related to the recently submitted seismic hazard report. Thanks, Steve Stephen M. Wyman USNRCINRRIJLDIHMB Office: 0-13G9 MS: 0-13C5 301-415-3041 (Voice) 301-415-8333 (Fax) Stephen.Wyman@nrc.gov Sent:24 Apr 2015 14:32:36 +0000 To:Munson, Clifford;Stieve, Alice Cc:Jackson, Diane;Devlin-Gill, Stephanie;Hill, Brittain

Subject:

Palo Verde Source Information for: SSHAC Documentation from PPRP-IT Team Attachments:SSC SSHAC Documentation of PPRP-TI-Team lnteraction.pdf Cliff. Alice, Stephanie, Please let me know if this is the missing piece. They have this one file on the SSC in the reading room. Thanks, Nick From: Munson, Clifford Sent: Tuesday, April 21, 2015 4:14 PM To: Difrancesco, Nicholas; Ake, Jon Cc: Jackson, Diane; Shams, Mohamed; Vega, Frankie; Graizer, Vladimir; John Stamatakos <jstam@swri.org> (jstam@swri.org); Hill, Brittain; Seber, Dogan; Vega, Frankie; Stirewalt, Gerry

Subject:

RE: DCPP, Palo Verde, and Columbia Audit Information: SSHAC Documentation from PPRP-IT Team Importance: High Nick, We took a quick look at the contents of the information for DCPP and PVNGS. The DCPP folder contains the PPRP-TI correspondence and interactions on the source model and ground motion model SSHACs. However, the PVNGS only has the ground motion model SSHAC PPRP-TI team material and not for the Source model. Please let us know when we can get the source model PPRP-TI team documentation. Thanks, Cliff From: Difrancesco, Nicholas Sent: Tuesday, April 21, 2015 1:25 PM To: Munson, Clifford; Ake, Jon Cc: Jackson, Diane; Shams, Mohamed; Vega, Frankie; Graizer, Vladimir; John Stamatakos <jstam@swri.org> (jstam@swri.org); Hill, Brittain; Seber, Dogan; Vega, Frankie; Stirewalt, Gerry

Subject:

DCPP, Palo Verde, and Columbia Audit Information: SSHAC Documentation from PPRP-IT Team Folks, Please control distribution to the designated review team member for the following references. Following your audit review, please advise if information reviewed should be docketed to support development of the hazard staff assessment or RAls. DC Audit Information S:\Diablo Canyon R2.1 Seismic lnformation\SSHAC Documentation of PPRP-TI Team Palo Verde Audit Information S:\Palo Verde R2.1 Seismic lnformation\SSHAC Documentation of PPRP-TI Team Columbia Information is on ePortal (PM action to work through access controls). Also, licensee plans to work with PNNL to post information on public website. Thanks, Nick From: Soenen, Philippe R [11] Sent: Tuesday, April 21, 2015 10:49 AM To: Difrancesco, Nicholas Cc: Jahangir, Nazar

Subject:

DCPP information on Certrec Nick, We have uploaded the PPRP information onto Certrec IMS and granted access to Vladimir Grazier, John Stamatakos, and yourself. Here is how you get to the PPRP information in Certrec:

• Login to ims.certrec.com
• Click on "Inspections"
• Set status to "In Progress" and Plant to "Diablo Canyon"
• Click "Search" button.
• Click link to "Self-Assessment I Audit-Review of PPRP Comments and TIT Resolution"
• Click on the "NRC Requests" tab
• Click on what you would like to see. Please let me know if you have any questions. Regards, Philippe Soenen Regulatory Services Office -805.545.6984 Cell -805.459.3701 PG&E is committed to protecting our customers' privacy. To learn more, please visit http://www.pge.com/about/company/privacy/customer/

LCI Mr. Ronald Gaydos Project Manager Engineered Equipment & Major Projects Westinghouse Electric Company 1000 Westinghouse Drive CWHQ3-41 OM Cranberry Township, PA 16066

Subject:

Additional Documentation for the PVNGS SSC Report Mr. Gaydos, I .l'tlis Consultants I nh*rnational. Im*. 27-1-11 1,.>urn..:y H'.>ad. S11it<.: Vakni:ia. (;\ 91 (li<*l) lax (Md) April 17, 2015 Lettis Consultants International, Inc. (LCI) is pleased to submit this additional documentation associated with the Palo Verde Nuclear Generating Station (PVNGS) Seismic Source Characterization (SSC) Report (Revision 0, dated February 2015). This additional documentation satisfies deliverable requirements for Task 1, as described in Project Impact Notice (PIN) No. 8 for Scope Changes to the Arizona Public Service (APS) 2.1 Seismic Hazards Evaluation (SHE) Project. The U.S. Nuclear Regulatory Commission (NRC) requested that APS provide additional information detailing the interactions between the Participatory Peer Review Panel (PPRP) and the Technical Integrator (Tl) Team. The requested information is provided in the three attachments that accompany this letter:

• Attachment 1: PPRP Comments on the Project Plan and Tl Team Responses.
• Attachment 2: Formal Correspondence Between the Tl Team and the PPRP.
• Attachment 3: PPRP Comments on the Draft SSC Report and Tl T earn Responses. Please do not hesitate to contact us with any questions. Sincerely, Lettis Consultants Inc. \' * \ I I \ ,___,. \) \ . t. v* . i \....( ' J
• J Ross Hartleb Project Manager LCI Project No. 1056.001 April 17, 2015 ATTACHMENT 1 Participatory Peer Review Panel (PPRP) Comments on the Project Plan and Technical Integrator (Tl} Team Responses Senior Seismic Hazard Analysis Committee (SSHAC) Level 3 Seismic Source Characterization Palo Verde Nuclear Generating Station (PVNGS) This attachment contains technical comments made by the PPRP on the initial issue of the Project Plan dated January 17, 2013, and provides a record of the Tl Team response to each comment. Comments were provided to the Tl Team on January 23, 2013. The Plan Plan was revised and reissued on February 19, 2013. April 17, 2015 PVNGS SSC Additional Documentation Attachment 1, Page 1 of 4 COMMENT-RESPONSE LOG PALO VERDE SSHAC LEVEL 3 PROJECT PLAN PPRP COMMENTS AND Tl TEAM RESPONSES No. Date Location in Project PPRP Comment Summary of Revisions to Project Plan Received Plan 1 1/23/2013 "Introduction" paragraph Is this word (i.e., "adequately") used in Text revised to indicate that the term "adequately" 3, page 2. this context in the SSHAC references? I is used in this context by NRC (NUREG 2117). hope so, as it is a soft term that lacks Specifically, text revised to read, "Moreover, the specificity. NRC (2012a, p. 89) indicates that successful implementation of the SSHAC Level 3 process 'implies a complete and well-documented hazard study that contributes to regulatory assurance that the hazard has been robustly evaluated and that the associated uncertainty has been adequately captured."' 2 1/23/2013 "Objective of the Study" CBR and TOI are defined in the previous Text revised as suggested. paragraph 1, page 2. paragraph and so do not need to be defined again. 3 1/23/2013 "Description of SSHAC SSHAC has already been defined; Text revised as suggested. Methodology" paragraph SSHAC didn't publish the methodology, 1, page 2. the NRC did. I suggest reorganizing the sentence along the lines of "In 1997 the SSHAC methodology was published by the NRC as NUREG ... " 4 1/23/2013 "Description of SSHAG Is this phrase (i.e., "reasonable The term "reasonable regulatory assurance" is Methodology" paragraph regulatory assurance") from the NRG? replaced by "increased regulatory assurance", 3, page 3. You might put it in quotes and cite the which is directly quoted from NRG (NUREG reference. 2117). 5 1/23/2013 "Selection of SSHAC As noted in my earlier comment, is this The use of "adequately" here is consistent with Level" paragraph 1, (i.e., "adequately") NRC usage? NRC (NUREG 2117, p. 89). See response to page 3. comment #1. No change to text. 6 1/23/2013 "Palo Verde SSC Project I tried to clarify was seemed to me to be Text revised as suggested. Organization" paragraph somewhat awkward language in the 4 (definition of "Project paragraph. Sponsor"), paqe 5. April 17, 2015 PVNGS SSC Additional Documentation Attachment 1. Page 2 of 4 COMMENT-RESPONSE LOG PALO VERDE SSHAC LEVEL 3 PROJECT PLAN No. Date Location in Project PPRP Comment Summary of Revisions to Project Plan Received Plan 7 1/23/2013 "Palo Verde SSC Project Does this (i.e., "State agencies"} mean Text revised to specify "State of Arizona Organization" paragraph Arizona? Maybe should say so. Might agencies." 16 {definition of "Outside other states be interested in sending Observers"), paqe 7. representatives? 8 1/23/2013 "Palo Verde SSC Project Suggest replacing "progressively" with Text revised as suggested. Work Plan" paragraph 4 "continuously" or delete. {definition of "Evaluation"), page 8. 9 1/23/2013 "Palo Verde SSC Project This phrase (i.e., "participating in working Text revised to read, "The PPRP will be involved Work Plan paragraph 4 meetings, as needed.") is not clear. I in the evaluation process through attending (definition of suggest that at least one PPRP member workshops, reviewing interim project "Evaluation}, page 8. attend each working meeting, with a documentation, and attending selected working responsibility to report back to the other meetings." PPRP members on the meeting. In all likelihood, the written summary of each working meeting prepared by the Tl Team would be sufficient documentation of the meeting for PPRP purposes. This activity should be represented in the budget for the PPRP. 10 1/23/2013 "Palo Verde SSC Project I think this {i.e., the phrase "if needed" in Text revised as suggested. Work Plan" paragraph 9 reference to review by regulatory {definition of officials) could be deleted-regulatory "Documentation"), page review is needed! 9. 11 1/23/2013 "Structure of A written summary should be produced Text revised to read, "A summary session will be Workshops" paragraph for the workshop; would the compilation provided at the conclusion of each day. The intent 1, page 10. of results of the daily summary sessions of the summary sessions is to identify action items constitute the written summary? Does and key findings from the workshop. These action this {i.e., "workshop presentations will be items and key findings will be summarized in documented") mean they will be included slides presented during each summary session. in the project files? All workshop materials and presentations will be included in the project file." 12 1/23/2013 "Kev Proiect Tasks" Instead of "Exploration of kev data," Text revised as suaaested to read, "Presentation April 17, 2015 PVNGS SSC Additional Documentation Attachment 1. Page 3 of 4 COMMENT-RESPONSE LOG PALO VERDE SSHAC LEVEL 3 PROJECT PLAN No. Date Location in Project PPRP Comment Summary of Revisions to Project Plan Received Plan paragraph 7 (under would it be clearer to say "Presentation and discussion of key data, data uncertainties, 'Task 4"). page 12. and discussion"? What is the and appropriate use and limitations of the data "exploration" aspect you were aiming to and their interpretations." emohasize? 13 1/23/2013 "Key Project Tasks" To me, full evaluation must involve Text revised as suggested to read. "SSC logic paragraph 12 (under discussion and clarification with the trees and Source Evaluation sheets will be "Task 7"). page 14. model developers. Do you mean that the provided to the PPRP prior to Workshop 3 so that material provided prior to Workshop 3 the PPRP will be able to fully review in detail the will enable the PPRP to fully evaluate the V3 SSC model before the workshop. model during the workshop, such that evaluative PPRP comments during the workshop and in the written PPRP report would be comprehensive? I agree that receiving the logic trees and source evaluation sheets at the workshop would limit the PPRP evaluation process. 16 1/23/2013 "Project Schedule" Should put in the project completion Text revised as suggested to read, "in order to paragraph 2. page 18. date. comply with the NRG-mandated 50.54(f) completion date of March 2015." April 17, 2015 PVNGS SSC Additional Documentation Attachment 1. Page 4 of 4 ATTACHMENT 2 Formal Correspondence Between the Technical Integrator (Tl) Team and the Participatory Peer Review Panel (PPRP) Senior Seismic Hazard Analysis Committee (SSHAC) Level 3 Seismic Source Characterization Palo Verde Nuclear Generating Station (PVNGS) This attachment provides the signed correspondence between the Tl Team and the PPRP regarding development of the SSHAC Level 3 seismic source characterization for the PVNGS. The table below identifies the subjects and dates for the signed correspondence. Subject Date PPRP letter no. 1: Comments on Project Kickoff Meeting ("Workshop O") April 24, 2013 PPRP letter no. 2: Field trip to PVNGS site and vicinity following Workshop #1 April 29, 2013 Tl Team response to comments from PPRP on Project Kickoff Meeting May 7, 2013 PPRP letter no. 3: Comments on Workshop #1 June 5, 2013 Tl Team response to comments from PPRP on Workshop #1 July 15, 2013 PPRP letter no. 4: Comments on Workshop #2 October 23, 2013 Tl Team response to comments from PPRP on Workshop #2 November 26, 2013 PPRP letter no. 5: Field review of geologic mapping March 26, 2014 Tl Team response to comments from PPRP on field review of geologic mapping March 26, 2014 PPRP letter no. 6: Comments on Workshop #3 May 9, 2014 Tl Team response to comments from PPRP on Workshop #3 May 14, 2014 PPRP closure letter February 26, 2015 April 17, 2015 PVNGS SSC Additional Documentation Attachment 2, Page 1 of 51 April 24. 2013 Dr. Ross D. Hartleb LCI Project Manager. Palo Verde NGS Seismic Ha7.ard Evaluation Project Lettis Consultants International. Inc. 27441 Tourney Road, Suite 220 Valencia. CA 91335 SURJECT: Seismic Source Characterization (SSC) Participatory Peer Review Panel Letter No. I: Palo Verde \luclcar Generating Station Seismic I lazard Evaluation Project Kickoff Meeting (Workshop 0)

Dear Dr. Hartleb:

As the designated SSC Participatory Peer Revicv,* Panel (PPRP) for the Palo Verde Nuclear Generating Station (PV:"JGS) Seismic Hazard Evaluation Project. we (Savage. \1achettc, and Rockwell) wish to express our appreciation for the opportunity to attend the Project Kickoff Meeting (Workshop 0) on January 2L2013. We also thank you for coordinating our travel arrangements and providing a hospitable setting for the meeting in your Walnut Creek office. The Kickoff Meeting was well organized and conducted in a professional manner; it represents a successful start to the Project. The agenda and the conduct or the \1ccting '>Vere thoughtful. thorough, and efficient. We were pleased that the sponsor (PVNGS) was \Vell represented and actively participated in the Meeting. It \.\as useful for the PPRP to become informed by the Project Sponsor about the characteristics of the PV"l\GS at the start of the meeting. The SS! IAC training early in the meeting established the rigor or the SSI IAC Level 3 process, and the subsequent presentations info1med us about the Project Plan (dated January 17, 2013) and the existing PYNGS SSH AC Level 2 seismic source characterization model. The discussion of data requirements led directly to the need to identify resource and proponent experts: we appreciate the planned involvement of the PPRP in identifying these experts. The follov .. *-ing comments arc numbered consecutively for reference in any subsequent communications. We do not include shon technical comments that were provided during the Meeting. Following the practice that was agreed upon during the Meeting. we have underlined comments to which we would appreciate written responses. 1. The PPRP was provided '>-vith the Project Plan (dated January 17. 2013) in advance of the Kickoff Meeting. Although there was no formal discussion during the meeting of our detailed comments on the Project Plan, \VC think that the Project Plan is aligned well v.*ith the SSHAC Level 3 methodology and is comprehensive in its scope. We provided Dr. Ross D Hartleb 2 Final 4/24/13 additional comments after the meeting by email on January 23. 2013. We received a revised version of the Project Plan dated February 19. 20 I 3. The comments we provided appear to have been addressed satisfactorily, and we think the Plan is clearer and thus more effective for its intended use. You indicated that future revisions of the Project Plan could be made as the need for revisions arises. 2. The relationships betv..*een the Lcttis Consultants International (LCI) team and the Project Sponsor (PVNGS) and with Westinghouse Electric Company (the overall Project Manager for the PVNGS Seismic Hazard Evaluation Project) appear to be open and effective. We noted. for example. the care with which the protocol for releasing reports was discussed and established. 3. We concur with the benefits of having a recent SSHAC Level 2 seismic source characterization for the PVNGS site. However, care will need to be taken to avoid the occurrence of anchoring (e.g .. cognitive bias). The Project Plan (p. 2) provides a procedure intended to address this subject using self-evaluations. but docs not clearly include independent perspectives that could identify a condition of bias. We would apprecjale your_informing us of how you plan to obtain independent views of a.ny P9SSible bias on the Team's part. 4. Jc was helpful for the PPRP to have participated via conference call with the Ground Motion Characterization (GMC) team members during the SSC meeting. There was the appearance of a gap in communications regarding G\1C-SSC interface items that came out in Norm Abrahamson' s discussion. l t is advantageous to have Thomas Rock we 11 of the SSC-PPRP also serving on the OMC-PPRP for the Project lo help assure good coordination .. Evt;:_n_s.9..:. appreciate Y9.!l!. i!)formipg µs of how you intend to nu1intain a.n effective interface between the G\lf C and SSC aspects of the PSHJ\. Please contact us if you wish further discussion of any of our observations and comments. Sincerely yours, Dr. William L. Savage (Chair) Mr. Michael t\. Machette Dr. Thomas K. Rockwell PPRP Letter# I: PVNGS SSC WSO April 29, 2013 Dr. Ross D. Hartleb LCI Project Manager, Palo Verde NGS Seismic Hazard Evaluation Project Lettis Consultants International, Inc. 27441 Tourney Road, Suite 220 Valencia, CA 91335

SUBJECT:

Seismic Source Characterization (SSC) Participatory Peer Review Panel Letter No. 2: PPRP Field Trip to the Palo Verde Nuclear Generating Station site and vicinity following Workshop l, April 11, 2013

Dear Dr. I lartleb:

With PVNGS employee Mr. Chris Wandall as our host, the PPRP visited the Palo Verde Nuclear Generating Station (PVNGS) area on the morning of April 11, 2013. We arrived about I 0:45 a.m. and left about 12: 15 p.m., so our visit was a brief 1.5 hours long. Mr Wandall had broughl along a copy of Arizona Geologic Map DGM-47 by Pearthree and others (2006), which is the Geologic Map of the Wintersburg 7 .5-minute Quadrangle, Maricopa County, Arizona. The PYNGS is located in the southwest corner of the quadrangle and minor parts of the adjoining three maps. Our first observation is thal the site is characlerized by low relief and surrounded on at least three sides by small hills comprised of basalt (middle Miocene, ca. 21 m.y.), which is the youngest and only bedrock unit exposed in the area. This basalt is mapped as largely undifferentiated, but locally is split inlo two units on the basis of plagioclase phenocryst conlent (5-10%1 in the upper unit and sparse in the lower unit). Interestingly, small knobs of basalt on the north margin of the PYNGS arc mapped as upper and lower basalt with an inferred (dotted) fault separating outcrops with apparent down-to-the-south motion of tens to a hundred (?) feet. The mapped fault was likely inferred from the outcrop pattern, was probably of small displacement (for a bedrock fault), and was not mapped in adjacent Quaternary deposits as old as unit Qi2 (probably late middle Pleistocene, >I 00'? ka). The entire PVNGS site is mapped as "disturbed ground" owing to the massive amount of excavating and regrading that occurred during construction of the facilities in the late 1970s and early 1980s. We drove onto the site but noticed no exposures of any great depth, so any surficial geologic information would have to be obtained from pre-1976 aerial photography and mapping done for the initial site characterization. We were more successful in a few road cuts to the west and south of the PYNGS entrance (west side, south of reactors and cooling towers). In one bedrock-cored road cut lhere are south to southwest dipping ( 45°?) basalts and sedimenlary interbeds. On the north side of this cut, the colluvial apron of basalt fragments is completely cemented by PPRP Lettcr#2: PVNGS SSC PPRP Site Visit on 4/11/13 Dr. Ross D. Hartleb 2 FINAL 4/29/ 13 calcium carbonate, indicating that the eroded north slope of the hill was very stable for a long time and graded to a lower level (calcrctcs project below the road grade). To the north of this road cut there arc shallow road cuts (ditches) in a Quaternary piedmont deposit that we suspect correlates with Pearthree and others' unit Qi2. Three mapped Qi (intennediate) units are late to middle Pleistocene. The map unit description says units Qi2 and Qi I have stage Ill to IV morphology calcic soils, but all of the Qi I units mapped in the quadrangle arc to the cast, trending parallel to the I lassayampa River. Older Quaternary to Tertiary alluvium (unit QTs) is locally exposed to the north in the quadrangle and this unit may comprise a basin-fill unit since it includes an extensive clay-rich unit (the Palo Verde clay) that is older than 2 Ma. This unit may exist beneath the site, burying eroded basalts that surface in the area. Generally speaking, there arc poor exposures and small rcllcf within the immediate area of the PVNGS. Better exposures for understanding the Quaternary surficial units arc to be found in the eastern half of the Wintersburg quadrangle, so any future field trip to the site should include stops to the east. On further review of the Wintcrsburg geologic map subsequent to the field trip, Mr. Machelle discovered an error in the description of the Quaternary unit Qi I as printed on the map. After consultation with Dr. Philip Pearthree, senior author of the map, Dr. Pcarthrcc corrected the map explanation and offered to have the Arizona Geological Survey reissue the revised map in the near future. This change, although seemingly minor, is important in that the Wintersburg map is the most detailed modern geologic map that includes the PVNGS site. The change in the map explanation is in Appendix I to this letter; the change is highlighted in yellow on page I 0 of the Appendix. We greatly appreciate the time that Mr. Wandall took to provide us with an efficient and comprehensive view of the site and adjacent property. This advance perspective of the site geology, general layout of the facilities, and adjoining land use is already benefiting our understanding of seismic hazard issues for the site. Please contact us if you wish further discussion of any of our observations and comments. Sincerely yours, Dr. William U. Savage (Chair) Mr. Michael N. Machcttc Dr. Thomas K. Rockwell PPRP Letter #2: PVNGS SSC PPRP Site Visit on 4/11/13 Dr. Ross D. Hartleb 3 FINAL 4/29/ 13 Appendix 1: Revised Map Explanation for the Geologic Map of the Wintersburg 7.5' Quadrangle, Maricopa County, Arizona Revised description of unit Qi1 -Middle Pleistocene alluvium is highlighted in yellow on PagelO. Geologic Map of the Wintersburg 7.5' Quadrangle, Maricopa County, Arizona by Philip A. Pearthree, Charles A. Ferguson, and Raymond C. Harris Arizona Geological Survey Digital Geologic Map 47 (DGM-47) January 2006 Scale l :24,000 ( l sheet) Arizona Geological Survey 416 W. Congress St., #100, Tucson, Arizona 85701 Research supported hy the U.S. Geological Survey, National Cooperative Geologic Mapping Program, under USGS award number #04IIQAG0072. The views and conclusions contained in this document are those (!(the authors and should not be i11te11Jreted as necessarily representing the C?/lkial policies, either expressed or implied, ofthe U.S. Government. The Wintersburg 7 Yi' quadrangle is located 40 to 50 miles (70-80 km) west of downtown Phoenix. The map area covers much of the piedmont between the Palo Verde Hills and the llassayampa River and a 7 mile ( 11 km) reach of the llassayampa River. The quadrangle includes a portion of the Palo Verde Nuclear Generating Station (PVNGS) and Interstate Highway l 0. It has experienced some suburban development associated wilh the PVNGS and is currently on the outer fringe of the grealer Phoenix metropolilan area, so more development is likely in the near future. The small bedrock hills in the southwestern quarter of the quadrangle were mapped by Charles Ferguson in the spring of 2005. Surficial deposits that cover most of the quadrangle were mapped by Philip Pearthree using color aerial pholos from 1979, high-resolution digital color orthophotos provided by the Flood Control District of Maricopa County, and topographic infonnation. Field checking was done in the spring, summer and fall of 2005. This mapping was done in conjunction with geologic mapping of the Flatiron Mountain 7 W quadrangle (Spencer el al, 2005) to the north, and this quadrangle map is one of eight 1 :24,000 scale geologic maps covering most of the llassayampa Valley that have been produced in 2004 -2006. PPRP Letter #2: PVNGS SSC PPRP Site Visit on 4/11/13 Dr. Ross D. Hartleb 4 FINAL 4/29/ 13 This mapping was completed under the joint State-Federal ST ATEMAP program, as specified in the National Geologic Mapping Act of 1992. Surficial Geology The Wintcrsburg quadrangle is almost entirely covered with surficial deposits laid down by the Hassayampa River or numerous smaller tributary stream systems. These surficial deposits were mapped primarily using stereo pairs of color aerial photos taken in 1979 for the Bureau of Land Management, high-resolution digital orthophotos provided by the FDCMC, and topographic infonnation obtained from the 7 U.S. Geological Survey quadrangle map. Mapping interpretations were verified by field observations during the spring, summer and fall of 2005; unit characteristics were described and unit boundaries were spot-checked in the field. The physical characteristics of Quaternary alluvial surfaces (channels, alluvial fans, floodplains, stream terraces) evident on aerial photographs and in the field were used to differentiate their associated deposits by age and source. This mapping was compiled over a digital orthophoto base from 2003 provided by the Flood Control District of Maricopa County. Mapping was done in a GIS format and the final lincwork was generated from the digital data. Several characteristics evident on aerial photographs and on the ground were used to differentiate various alluvial surfaces and deposits associated with them by age and source. The color of alluvial surfaces is primarily controlled by soil color, desert pavement development and rock varnish, and vegetation type and density. Significant soil development begins beneath an alluvial surface afier it becomes isolated from active flooding and deposition (Gile ct al., 1981, Birkeland, 1999). I Iolocenc soils typically have relatively subtle horizons and generally arc brown or gray in the field and on aerial photographs. More distinct, relatively obvious soil horizons develop over thousands to tens of thousands of years. Typical soil horizons in Pleistocene alluvial sediments of Arizona arc reddish brown argillic horizons (zones of clay accumulation) and white calcic horizons (zones of calcium carbonate and silica accumulation). In arid areas such as the lower Hassayampa Valley, day accumulation and reddening associated with argillic horizon development tend to be relatively weak even on old alluvial surfaces. On color aerial photographs and on the ground, older alluvial surfaces characteristically appear slightly redder or distinctly whiter (on more eroded surfaces) than younger surfaces. Dark rock varnish and gravel pavements also develop with time on stable alluvial surfaces, so well-preserved older surfaces typically have a dark brown color. Differences in the drainage patterns between surfaces also provide clues to surface age. Young alluvial surfaces commonly display distributary (branching downstream) or anastomosing (branching and rejoining) channel patterns. Areas adjacent to active channels commonly have little channel development because unconfined shallow flooding predominates. Dcndritic tributary (joining downstream) drainage patterns arc characteristic where modem drainages arc incised into older surfaces. Topographic relief between adjacent alluvial surfaces and the depth of entrenchment of channels can be detennined using stereo-paired aerial photographs and topographic maps. Young surfaces arc minimally dissected and arc less than I m above channel bottoms. Active channels PPRP Letter #2: PVNGS SSC PPRP Site Visit on 4/11/13 Dr. Ross D. Hartleb 5 FINAL 4/29/ 13 are entrenched 1 to 5 m below Pleistocene alluvial surfaces, and the older surfaces typically have been moderately to severely rounded by erosion. Ages of various surficial deposits of the map area were roughly estimated based on regional correlations to similar surficial deposits in southern Arizona. Variations in the distribution of surfaces of different ages and sources and concomitant variations in dissection across the quadrangle provide evidence regarding the recent geologic evolution of this area. Generally, areas along the Hassayampa River are moderately to deeply dissected. The highest terrace remnants of the Hassayampa River (unit Qi,r) record the level of the river bed in the early to middle Quaternary. Qi1r terraces cap a several hundred meter thick aggradational sequence that was deposited during late Tertiary to early Quaternary (units QTs and QTsr) (Shoustra et al., 1976). Adjacent piedmont areas to the west and north were aggrading in the late Pliocene and early Quaternary as well (unit QTs). At that time the river was probably was depositing sediment across a fairly broad floodplain in the eastern part of the quadrangle, and distal alluvial fans on both sides of the river were interfingering with the river floodplain. Since then the Hassayampa River has downcut 10 to 15 m, with incision increasing slightly to the north. Preservation of Pleistocene river terraces recording intermediate levels of the I lassayampa River is poor. The valley bottom along the I lassayampa River consists almost entirely of modem channel deposits (unit Oyer) and late Holocene floodplain deposits (Qy2r). Tributary washes immediately west and east of the Hassayampa River have downcut in response to incision of the river, and late Quaternary deposits arc quite limited in extent along these drainages. In the western 2/3 of the quadrangle, piedmont washes drain to the south to the Gila River or Centennial Wash, a sizable tributary of the Gila River. Much of this piedmont is mantled by Pleistocene tributary deposits (units Qi1, Qii, or Qi.;). Older Pleistocene deposits (Qi1 and Qh) have been eroded into broadly rounded or moderately rounded ridges, respectively. The relatively small tributary washes that drain this area are incised less than a few meters below adjacent Pleistocene alluvial surfaces. Even though the amount of net incision is modest, there is enough topographic confinement of active fluvial systems that late Pleistocene deposits typically are found on the fringes of the eroded middle Pleistocene ridges, and Holocene deposits are found on valley bottoms. Agricultural activity, more recent residential development, aggregate pits and the PVNGS have modified the landscape to greater or lesser degrees. Areas arc mapped as "disturbed" where the surficial deposits are profoundly altered (gravel pits, nuclear plant, interstate surficial deposits other areas with less profound disturbance are depicted with concealed (dotted) contacts. Geologic Hazards and Aggregate Resources The geomorphology and surficial geology of the quadrangle provide clues to the extent and character of flood hazards and the availability of aggregate resources. Geologically young fluvial deposits (units Qye, Qy2, and locally Qy1 along tributary washes and units Oyer, Qy2r along the Hassayampa River) record recent fluvial activity. The Hassayampa River is incised and flooding is restricted to the valley bottom. The fact that the valley PPRP Letter #2: PYNGS SSC PPRP Site Visit on 4/11/13 Dr. Ross D. Hartleb 6 FINAL 4/29/ 13 bottom is covered almost entirely by late Holocene deposits strongly suggests that the valley bottom is the floodplain, and all portions of it have been subjected to recent inundation and deposition. Flooding is restricted to relatively narrow corridors along the incised tributary washes that drain directly to the Hassayampa. Flood-prone areas are somewhat more extensive in the western 2/3 of the quadrangle where incision is modest. Valley bottoms covered with young deposits but channels arc quite small, implying that shallow sheet flooding and bank erosion along channels arc the principal flood hazards. Although valley bottoms are fairly wide, there are no major distributary channel networks or active alluvial fans on the piedmont. Aggregate resources were extracted from several small pits in piedmont surficial deposits near Interstate Highway l 0, probably for construction of the highway. Two larger aggregate operations are currently active along the Hassayampa River north ofl-10. These operations arc apparently mining aggregate primarily from I loloccne river deposits, but they may be drawing upon older river deposits as well. The potential for useful aggregate resources in older river deposits that flank the modem floodplain is not known because the thickness of these deposits is uncertain. Both earth fissures (I larris, 200 I) and giant desiccation cracks (I Iarris, 2003) have been recognized in the southwestern portion of the quadrangle. A new earth fissure opened in the summer of 2000 about 3 miles (5 km) southeast of Wintersburg. The fissure trends nearly north-south and is about I, I 50 ft (350 m) long. The fissure is very young, with narrow, steep sides and a highly irregular apparent depth ranging from <l foot to >8 feet over short distances. In two locations the fissure is en echelon, with NW-SE steps. There is no discemable vertical offset across the fissure. The location of the fissure, at the edge of the Palo Verde basin and somewhat in line with the trend of a small hill, suggests that a shallow buried bedrock ridge may extend south of the hill beneath the trace of the fissure. If this scenario is correct, the crack may represent fissuring due to compaction and subsidence on either or both sides of the buried ridge. Adjacent lo the new earth fissure is an area of giant desiccation cracks that opened at the same time as the earth fissure. Alignments of established vegetation in some portions of the polygonal desiccation crack network demonstrate that cracking has occurred periodically in the past. Additional areas of giant desiccation cracks were mapped by Harris (2003) immediately west and south of the Wintcrsburg quadrangle. Bedrock Geology Basalt lava flows cap several hills in the southwest comer of the map area. The basalt is part of an extensive lava field known as the Palo Verde I I ills lava field. The flows were sampled extensively in and around the PVNGS prior to its construction. The lavas range in age from 16.9 to 20.7 Ma (Shoustra el al., 1976; Shafiqullah et al., 1980). In general, the lavas arc gently dipping, but locally, dips of up to 70 degrees have been reported for lavas to the west of this map area (Shafiqullah ct al., 1980). The westernmost hills, which lie directly north of the PVNGS, are divided into two map units. A gently northeast-dipping contact between the units, concealed by colluvium, is PPRP Letter #2: PVNGS SSC PPRP Site Visit on 4/11/13 Dr. Ross D. Hartleb 7 FINAL 4/29/ 13 interpreted to be present on the westernmost hill. The upper lava contains abundant mafic (pyroxene and/or olivine), and plagioclasc phcnocrysts (Tbu). The lower lava contains only mafic phcnocrysts (Tbl). Similar units arc found in the low hills just to the cast. Two interpretations are possible for the vokanic stratigraphy and structure of this area. The simplest interpretation, which is depicted on the map, shows the sequence of upper and lower lavas repeated by a southwest-side-down nonnal fault with modest (50-100 m) displacement. An alternative interpretation is that there is no fault, but that the volcanic stratigraphy is more complex, with intertonguing flows of different composition. The pair of hills lying to the cast of the PVNGS arc composed of amalgamated flows of ma fie phcnocryst-porphyritic basaltic lava (Tb) that appear to dip moderately to the southwest. These lavas were interpreted by Shafiqullah et al. ( l 980) to represent the oldest in the area. This sequence may correlate with the Tbl map unit, but since there are no other types of lava in the area, and since the flows dip in the opposite direction these rocks arc mapped as undifferentiated basalt lava (Tb). The difference in dip between the eastern and western hills implies that an intervening structure may exist. Acknowledgments. The Flood Control District of Maricopa County provided resolution digital orthophotos that were used to accurately locate surficial geologic unit boundaries. References Birkeland, Peter W., 1999, Soils and Geomorphology (3rd Ed.), New York: Oxford University Press, 429 pp. Gile, L.H., Hawley, J.W., and Grossman, R.B., 1981, Soils and geomorphology in the basin and range area of southern New Mexico --guidebook ot the Desert Project: New Mexico Bureau of Mines and Mineral Resources Memoir 39, 222 pp. Harris, R.C., 2001, A new earth fissure near Wintersburg, Maricopa County, Arizona: /\ZGS OFR Ol-10, 23 p. I larris, R.C., 2003, Additional giant desiccation cracks near Wintcrsburg, Maricopa County, Arizona: AZGS OFR 03-07, l 7 p. Machcttc, M.N., 1985, Calcic soils of the southwestern United States: in Weide, D.L., ed., Soils and Quaternary Geology of the Southwestern United States: Geological Society of America Special Paper 203, p. 1-2 l. Shafiqullah, M., Damon, P. E., Lynch, D. J., Reynolds, S. J., Rehrig, W. A., and Raymond, R. 11., 1980, K-Ar geochronology and geologic history of southwestern Arizona and adjacent areas, in Jenney, J.P., Stone, C., (eds.), Studies in western Arizona: Arizona Geological Society Digest 12, p. 201-242. PPRP Letter #2: PVNGS SSC PPRP Site Visit on 4/11/13 Dr. Ross D. Hartleb 8 FINAL 4/29/ 13 Shoustra, J. J., Smith, J. L., Scott, J. D., Strand, R. L., and D., 1976, Geology and scismicity, site lithologic conditions and Appendix 2Q (Radiometric age), in Palco Verde Nuclear Generating Stations I, 2, and 3, Preliminary safety analysis report: Arizona Public Service Commission, v. 2, Section 2.5; v. 8, Appendix 2Q. Spencer, J.E., Youberg, Ann, and Ferguson, C.A., 2005, Geologic map of the Flatiron Mountain 7 Yi' Quadrangle, Maricopa County, Arizona: Arizona Geological Survey Digital Geologic Map DGM-46, scale l :24,000. Surficial Map Units Piedmont Alluvium Quaternary and late Tertiary piedmont deposits from the Belmont Mountains to the north cover the western 2/3 of the Wintersburg quadrangle. This alluvium was deposited primarily by larger tributary streams that head to the north of the quadrangle; these larger streams and smaller streams that in this quadrangle have eroded and reworked some of these deposits. Clast lithologies include basalt and fclsic volcanic rocks with lesser amounts of granite. Deposits range in age from modem to Pliocene. Abbreviations used are ka, thousands of years before present, and Ma, millions of years before present. Qyc -Modern stream channel deposits. Active channel deposits composed of very poorly-sorted sand, pebbles, and cobbles with some boulders to moderately-sorted sand and pebbles. Channels are generally incised 0.5 to 2 m below adjacent I lolocenc terraces and alluvial fans, but may be incised as much as 4 m below adjacent Pleistocene deposits. Channel morphologies generally consist of a single thread, relatively deep channel or multi-threaded smaller, shallower channels with gravel bars. Channels are extremely flood prone and are subject lo deep, high velocity flow in moderate to large flow events. Areas adjacent to Qyc deposits may be prone to lateral bank erosion. Qn -Late Holocene alluvium. Young, typically fine-grained deposits in floodplains, low terraces and small channels. Along the larger drainages, unit Qy2 sediment is generally poorly to very poorly sorted silt, sand, pebbles, and small cobbles; floodplain and terrace surfaces typically are mantled with sand and finer sediment. On lower piedmont areas and in smaller tributary washes young deposits consist predominantly of moderately sorted sand and silt, with some pebbles and cobbles in channels. Soils arc pale brown in color (I 0 YR), and soil development is very weak, consisting of slight carbonate accumulation. Channels generally are incised less than l m below adjacent young surfaces, but locally incision may be as much as 2 m. Channel morphologies generally consist of a single-or multi-threaded channels with gravel bars adjacent to low flow channels. Channels arc flood prone and may be subject to deep, high velocity flows in large flow events. Substantial lateral bank erosion may occur in these deposits, and flood flows may significantly change channel morphology and flow paths. Local relief varies from fairly smooth channel PPRP Letter #2: PVNGS SSC PPRP Site Visit on 4/11/13 Dr. Ross D. Hartleb 9 FINAL 4/29/ 13 bottoms to undulating bar-and-swale topography that is characteristic of coarser deposits. Terraces have planar surfaces, but small channels arc common. Qy1 -Holocene alluvium. Older Holocene terrace deposits found mostly along the margins of incised drainages throughout the map area. Qy1 surfaces are higher and less subject to inundation than adjacent Qy2 surfaces. Qy1 terraces arc generally planar but local surface relief may be up to I m where gravel bars arc present. Qy1 surfaces are < 2 m above adjacent active channels. Surfaces typically are sandy but locally have unvarnished open fine gravel lags or pebble and cobble deposits. Qy1 soils typically arc brown in color (7.5 to 10 YR) with weakly developed stage I calcium carbonate accumulation (sec Machcttc, 1985, for description of stages of calcium carbonate accumulation in soils). Qyf -Fine-grained Holocene alluvium. Thin, fine-grain I loloccnc alluvial deposits fonncd in swales on ridges of mid-Pleistocene fan deposits. These deposits arc very thin, typically less than 0.5 m thick, but locally may be 1 m or more thick. Sediment typically is brown (7 .5YR) mainly silt and sand, with occasional deposits of open, unvarnished, fine gravel lag. Soil development is minimal, with substantial disseminated carbonate but little visible carbonate accumulation. Qy Holocene alluvial deposits, undifferentiated. Qh -Late Pleistocene alluvium. Unit Qi.; is composed of slightly dissected relict alluvial fans and terraces. Active channels are incised up to about 2 m below QiJ surfaces, and Qb fans and terraces generally are lower in elevation than adjacent older surfaces. Qi.; deposits consist of pebbles, cobbles, and finer-grained sediment. Qi.; surfaces commonly arc fairly smooth with weak bar and swale topography and loose to moderately packed pebble and cobble pavements. Surface gravel clasts typically exhibit weak to moderate brown rock varnish but some surfaces in the northern part of the quadrangle that arc mainly composed of fine-grained volcanics arc more darkly varnished. Qi.; soils arc moderately developed, with brown loamy (7 .5 YR) near-surface horizons and stage II calcium carbonate accumulation. Qh -Middle to late Pleistocene alluvium. Unit Qi2 is composed of moderately dissected relict alluvial fans and terraces with moderate soil development. Qi:! surfaces are drained by broad swales and well-developed, moderately incised tributary channel networks; channels are typically 1-2 meters below adjacent Qh surfaces. Well-preserved, planar Qi2 surfaces arc smooth with pebble and cobble pavements; surface color is reddish brown; surface gravel clasts arc moderately to strongly varnished. More eroded, rounded Qi2 surfaces are characterized by strongly varnished, scattered, cobble to pebble lags. Soils associated with planar surface remnants typically contain reddened (5 to 7.5 YR), clay loam argillic horizons, with clay coatings and subangular blocky structure. Underlying soil carbonate development is typically stage III with areas to stage IV, and abundant carbonate through at least 1 m of the soil profile. In more eroded locations, argillic horizons have been removed and soils arc calcic throughout. PPRP Letter #2: PVNGS SSC PPRP Site Visit on 4/11/13 Dr. Ross D. Hartleb lO FINAL 4/29/ 13 Qi1 -Middle Pleistocene alluvium. Unit Qi 1 is composed of deeply dissected relict al1uvial fans. Qi I surfaces form rounded ridges that arc higher than adjacent Qi2 surfaces. Drainage networks include broad swales on the ridge tops and tributary channels incised 3 to 4 m. Underlying eroded QTs deposits are occasionally exposed along some ridge slopes and wash banks. Wcl1-prcscrvcd Qi I surfaces arc limited in extent, but have moderately to tightly packed cobble, boulder, and pebble lag. Surface clasts are strongly to very strongly varnished and commonly have carbonate rinds up to 2 mm thick. More eroded, rounded Qi 1 surfaces are characterized by variably varnished, scattered, cobble and boulder lags with locally exposed laminar carbonate horizons. Where well preserved, Qi 1 soils arc strongly developed with a dark red (5-2.5 YR), heavy clay argillic horizon and subangular blocky to prismatic structure, with underlying petrocalcic stage IV to V. More eroded surfaces have common carbonate fragments and accumulations on gravel clasts arc 1-2 mm thick. This unit approximately correlates to unit M 1 a of Field and Pcarthrcc ( 1991 ). Qi -Middle and late Pleistocene alluvial deposits, undifferentiated. QTs -Early Pleistocene to Pliocene alluvium. Unit QTs is composed of eroded al1uvial fan deposits, locally overlain by younger Quatemary units. QTs deposits typically are poorly exposed on ridge slopes, in wash banks, and in channels as strath terraces. The thickness of QTs deposits is variable, but certainly is at least tens of meters (Shoustra ct al., 1976). In the shal1ow subsurface, unit QTs includes an extensive day-rich unit (the Palo Verde day) that is older than 2 Ma (Shoustra et al., 1976). Surface exposures of QTs include poorly sorted, subangular to subrounded, carbonate cemented, tan, pebble to cobble conglomerates, moderately to well sorted, subangular to subroundcd, moderately induratcd, cross-bedded, red, pebbly sandstones, and buried paleosols. Hassayampa River Alluvium Quaternary and late Tertiary piedmont deposits associated with the I lassayampa cover the eastern margin of the Wintersburg quadrangle. Clast lithologies are quite diverse, but are principally mixed fine-grained volcanic rocks and granite. Clasts range from roundcd to subangular in shape. Deposits range in age from modern to Pliocene. Qycr -Active river channel deposits. Moderately lo poorly sorted sand, gravel and minor silt in recently active channels and lightly vegetated bars of the Hassayampa River. Gravel consists mainly of pebbles with some cobbles; clasts range from subangular to well-rounded. Qy2r -Late Holocene floodplain deposits. Sand, silt, and gravel deposits associated with the floodplain and low terraces along the I lassayampa River. Qy2r surfaces typically arc smooth and arc less than 2 m above the active channel. T crracc surfaces PPRP Letter #2: PVNGS SSC PPRP Site Visit on 4/11/13 Dr. Ross D. Hartleb l l FINAL 4/29/ 13 typically are covered with fine-grained floodplain deposits, but relict gravel bars and lenses arc common. Qy1r -Older Holocene river terrace deposits. Sand, silt, and gravel deposits associated with slightly higher terraces along the Hassayampa River. Terrace surfaces typically arc flat but rounded around their margins and arc less than 3 m above the active channel. Terrace surfaces typically arc covered with a fine gravel lag where preserved but are quite fine-grained where eroded. Qhr -Late Pleistocene river terrace deposits. Deposits associated with low intcnncdiatc terraces inset about 3 m above the I loloccnc floodplain of the Hassayampa River. Deposits consist of sand, silt, and gravel, with weak lo moderate soil carbonate (Stage 1-11) accumulation. Terrace surfaces typically are smooth and arc covered with fine-grained floodplain deposits, but relict gravel bars and lenses arc found locally. Qhr-Middle Pleistocene river terrace deposits. High intennediale terraces about 5 m above the Holocene floodplain of the llassayampa River. Terrace surfaces typically arc dissected by small tributary drainages but arc smooth away from the drainages. Terrace deposits are a mix of river sand, gravel, and silt and clay, but surfaces typically are covered with relict gravel deposits. Soil development is moderately strong, consisting primarily of stage JI to Ill caleic horizons. Qiir -Early to middle Pleistocene river deposits. Deposits associated with the highest terraces along the Hassayampa River that record the maximum aggradation of the river. Terrace surfaces arc broadly rounded, and the deposits arc moderately to deeply dissected by tributary drainages and the river and have been substantia11y modified by erosion. Exposures are poor, but subangular to well-rounded gravel is evident al the surface. Terrace surfaces are also typically covered with litter from underlying induratcd stage IV pctrocalcic soil horizons. Qi1r terrace surfaces arc more extensive than any of the younger Pleistocene terraces. T crrace surfaces range from about l 0 to 15 m above the active river channel, and rise slightly to the north across the quadrangle. QTsr -Pliocene to early Pleistocene river deposits. A sequence of old river deposits of unknown thickness that underlies the Qi1r terrace deposits. These deposits consist of river sand, gravel and sill with a substantial component of tributary sand and gravel. Local zones of substantial carbonate accumulation may represent moderately to strongly developed buried soils. Other Units Qtc -Quaternary hillslope talus and colluvium. Thin, steeply to moderately sloping, weakly bedded hillslope deposits mantling the middle and lower slopes of basalt hills. Deposits are locally derived and very poorly sorted, consisting of angular to subangular basalt cobbles and boulders with a matrix of sand, silt and clay. Older PPRP Letter #2: PVNGS SSC PPRP Site Visit on 4/11/13 Dr. Ross D. Hartleb 12 FINAL 4/29/ 13 hillslope deposits have darkly varnished cobble and boulder mantles and relatively clay-rich soils. d -Disturbed areas. Much of the quadrangle has been disturbed by human activities, particularly agricultural activities. This unit designation is used only in areas of substantial excavation or anthropogenic deposition, for example, major flood-control levees. Bedrock Units Thu -upper basalt. Basalt lava containing 3-7% -2mm ma fie phcnocrysts (pyroxene and/or iddingsite altered olivine), and 5-10% l-4mm plagioclase phenocrysts (samples: CAF-2-10637, 10638, 10639, 10643, 10649, 10650, 11343, 11344, 11345, 11346,and 11348) Thi -lower basalt. Basalt lava containing 3-7%, l-3mm mafic phenocrysts (pyroxene and/or iddingsite altered olivine), and sparse l-2mm plagioclase phenocrysts (samples: CAF-2-10640, 10644, 10646, 10648) Tb -basalt lava, undifferentiated. Basalt lava containing 2-7%, 0.5-3mm mafic phenocrysts (pyroxene and/or iddingsite altered olivine) with sparse plagiodase phcnocrysts <2mm (samples: CAF-2-10622, I 0626, I 0631, and I 0635). Shafiqullah ct al. ( 1980) report a whole rock, Kl Ar age of 20. 7 + 0.6 Ma for this unit, making it the oldest known lava from the Palo Verde lava field. PPRP Letter #2: PVNGS SSC PPRP Site Visit on 4/11/13 To: From:

Subject:

Dear Sirs,

William Savage (Participatory Peer Review Panel (PPRP) chair) Michael Machette (PPRP member) Thomas Rockwell (PPRP member) William Lett is (Project Technical Integrator (PTI)) May 7, 2013 Scott Lindvall (Seismic Source Characterization (SSC) Technical Integrator (Tl) Team Lead) Ross Hartleb (Lettis Consultants International (LCI) Project Manager) Response to comments from the PPRP on Workshop #0 (Project Kickoff Meeting) Palo Verde Nuclear Generating Station (PVNGS) Seismic Hazard Evaluation Project Senior Seismic Hazard Analysis Committee (SSHAC) Level 3 SSC This letter constitutes our response to comments from the PPRP's Letter No. 1 dated April 24, 2013 on the PVNGS SSC Workshop #0 ("Project Kickoff'), which was held on January 21, 2013. We appreciate the PPRP's thoughtful review of both the SSHAC process and the technical issues presented at Workshop #0. The PPRP's Letter No. 1 includes four specific comments on Workshop #0. Two of these comments (comments 3 and 4) contain underlined passages. As requested by the PPRP, we provide in this letter our specific responses to each of the PPRP's underlined comments. For ease of reference, our responses below are numbered in a manner consistent with the numbering of comments in PPRP Letter No. 1. Specific Comments PPRP Comment #3: We concur with the benefits of having a recent SSHAC Level 2 seismic source characterization for the PVNGS site. However, care will need to be taken to avoid the occurrence of anchoring (e.g., cognitive bias). The Project Plan (p. 2) provides a procedure intended to address this subject using self-evaluations, but does not clearly include independent perspectives that could identify a condition of bias. We would appreciate your informing us of how you plan to obtain independent views of any possible bias on the Team's part. Response to PPRP Comment #3: A SSHAC Level 2 SSC for the PVNGS was completed in 2012. The Tl team for that SSHAC Level 2 SSC included Scott Lindvall and Kevin Clahan. Gabriel Toro served as a hazard analyst for the SSHAC Level 2 probabilistic seismic hazard analysis (PSHA). The Tl team for the ongoing SSHAC Level 3 SSC comprises Scott Lindvall, Kevin Clahan, Gabriel Toro, and Ross Hartleb. Because of the partial overlap in personnel between the SSHAC Level 2 and SSHAC Level 3 Tl teams, the PPRP is correct in pointing out the potential for cognitive bias (or "anchoring") to the existing SSHAC Level 2 SSC model. The following steps have been taken to ensure independent views of any possible bias on the Tl team's part and to minimize cognitive bias: Page 1of3 Response to comments from the PPRP on Workshop #0 (Project Kickoff Meeting) -May 7, 2013

• The SSHAC Level 3 Tl team includes members who did not participate in development of the SSHAC Level 2 SSC. Specifically, PTI William Lettis and Tl team member Ross Hartleb did not participate in development of the SSHAC Level 2 SSC and thus bring fresh perspectives to the ongoing SSHAC Level 3 SSC effort. Gabriel Toro acted as a hazard analyst for the SSHAC Level 2 PSHA, but he did not participate in the development of the SSHAC Level 2 SSC. As such, Gabriel Toro also brings his fresh perspective to the SHAC Level 3 SSC Tl team.
• Discussions of cognitive bias will be included at the start of each workshop and working meeting by the PTI or Tl Lead. Moreover, if apparent cognitive bias arises at any point during a workshop or working meeting, the Tl Lead or other Tl team members or staff will be responsible for alerting the Tl team.
• Continual review of SSC development will be performed by the PPRP for the duration of the project. The Tl team expects that the PPRP will alert the Tl team of any perceived cognitive bias at any point during the project. PPRP Comment #4: It was helpful for the PPRP to have participated via conference call with the Ground Motion Characterization (GMC) team members during the SSC meeting. There was the appearance of a gap in communications regarding GMC-SSC interface items that came out in Norm Abrahamson 's discussion. It is advantageous to have Thomas Rockwell of the SSC-PP RP also serving on the GMC-PPRP for the Project to help assure good coordination. Even so, we would appreciate your informing us of how you intend to maintain an effective interface between the GMC and SSC aspects of the PSHA. Response to PPRP Comment #4: The PPRP is correct in noting the importance of, and need for, ongoing technical and logistical communication between the PVNGS SSC Tl team and the Southwestern United States Ground Motion Characterization (SWUS GMC) project. An effective interface between the SSC and GMC efforts will be maintained by the following:
• In addition to his role as PPRP member for the PVNGS SSC project, Thomas Rockwell also serves as a member of the PPRP for the SWUS GMC project. As such, he will be able to provide information and coordination between the SSC and GMC projects.
• The Project Plan defines the role of the PTI as a technical expert responsible for ensuring coordination and compatibility between the SSC and GMC Projects. William Lettis is the PTI for the PVNGS SSC project and, therefore, is responsible for maintaining effective communication between the SSC and GMC projects.
• Members of the PVNGS SSC project also serve as members of the SWUS GMC project. Specifically, PVNGS SSC hazard analyst Robin McGuire is the Palo Verde PTI for the SWUS GMC project. Thus, he will attend all PVNGS SSC and SWUS GMC workshops, be informed of SWUS GMC Tl team deliberations, and provide an important interface between the PVNGS SSC and SWUS GMC projects. Likewise, PVNGS SSC hazard analyst Melanie Walling serves as the Palo Verde hazard analyst for the SWUS GMC project. In this role, she attends all SWUS GMC workshops and working meetings. Thus, Melanie Walling will be able to provide to the PVNGS SSC Tl team her first-hand knowledge of discussions and activities of the SWUS GMC project, and vice versa.
• PTI William Lettis and Tl Team Lead Scott Lindvall attended and presented at SWUS GMC Workshop #1, which was held on March 19-21, 2013. This workshop also was attended by PVNGS SSC hazard analysts Robin McGuire and Melanie Walling.
• Hazard analyst Melanie Walling and Tl team member and Project Manager Ross Hartleb participate in weekly status conference calls for the Palo Verde Seismic Hazard Evaluation Project. These conference calls also include participants from Arizona Public Service (APS) and Page 2 of 3 Response to comments from the PPRP on Workshop #0 (Project Kickoff Meeting) -May 7, 2013 Westinghouse Electric Company. The purpose of these calls is to discuss project progress, schedule, and SSC-GMC interfaces. Closure We appreciate the comments from the PPRP on Workshop #0 and suggestions for improvement to the ongoing Palo Verde Seismic Hazard Evaluation Project. We are incorporating your observations, suggestions, and recommendations into our program to the extent possible. We look forward to seeing you again at Workshop #2 and to sharing with you our additional progress on the project at that time. Sincerely, (v,_fi__ kf1lu William Lettis PTI ,... .... . I I \ \..(-> 1 "1.:: I * \ , .. * * " , \ Ross Hartleb LCI Project Manager Scott Lindvall SSC Tl Team Lead Page 3 of 3 June 5, 2013 Dr. Ross D. Hartleb LCI Project Manager, Palo Verde NGS Seismic Hazard Evaluation Project Lettis Consultants International, Inc. 27441 Tourney Road, Suile 220 Valencia, CA 91335

SUBJECT:

Seismic Source Characterization Participatory Peer Review Panel Letter No. 3: Palo Verde Nuclear Generating Station Seismic Hazard Evaluation Project, Workshop No. I: Significant Issues and Data Needs

Dear Dr. Hartleb:

This letter provides the report of the Seismic Source Characterization (SSC) Participatory Peer Review Panel (PPRP) on the Palo Verde Nuclear Generating Station (PYNGS) Seismic Hazard Evaluation Project Workshop No. 1 (WS 1). The workshop was held on April 9-10, 2013, in Litchfield Park, AZ at the conference facilities of the Wigwam Resort. WS 1 is identified as Task 4 in the current version of the SSC Project Plan, dated February 19, 2013, and is also discussed in Section 4.6. l of NUREG-2117. In accord with these guidance documents, the PPRP attended WS I as observers during the daily proceedings of the two-day workshop to become informed by the presentations and discussions, and to review both lhe technical and procedural aspecls of the workshop. All three members of the PPRP (M. Machette, T. Rockwell, and W. Savage) attended WS 1 and observed all aspects of the workshop. The PPRP met at the end of each day with the TI lead, Tl Team members, and Sponsor representatives to provide verbal comments that could be used during the course of the ongoing workshop and in preparing this letter. The PPRP appreciated the preparations for and conduct of the workshop in terms of the hospitality and professionalism of the Sponsors and the Project Team and their staff. The well-planned and efficiently followed agenda for the technical presentations and discussions led to successfully illuminating both available resources and deficiencies. The comfortable facilities and staff of the Wigwam Resort also contributed to the effectiveness of the workshop. The PPRP' s general observations and as well as specific comments and recommendations arc provided in the remainder of this letter. Those parts of the comments that require a written response are underlined for clarity. PPRP Letter #3: PVNGS SSC WS l Dr. Ross D. Hartlcb 2 FINAL 6/5/13 General Observations Regarding the Workshop Process As described in NUREG-2117 and the SSC Project Plan, the scope and pmvose of WS I is narrowly defined with specific goals and purposes to identify hazard-significant technical issues, and to identify the available data and information need to address the issues. The detailed agenda for WS I laid out the goals and approach for the workshop in a fashion that is fully consistent with the above governing documents for a SSHAC Level 3 study. The PPRP appreciated being contacted with regard to finalizing a list of prospective Resource Experts to be invited to WS l. The initial list was thoughtfully developed and the individual members of the PPRP made additional suggestions and comments as they felt were appropriate. At the start of the Workshop, the PPRP particularly noted the articulate, thorough and energizing summary of the SSHAC methodology, project organization, guidance to the Resource Experts, and intra-project coordination as presented by William Lettis. For the purpose of improving the collegiality and communication during the Workshop, it would have been helpful to have been provided brief bios (name and titles, organization. technical area of interest, role in the project) for each of the meeting participants so that each participant could more quickly establish an intellectual and conversational relationship with his or her peers. It would also be helpful for future meetings to provide name tents for the table for each individual. Name tags should have the preferred nickname of the individual and project role or home organization. The interactions between the Project TI Team members, technical support staff and the invited Resource Experts (REs) were engaging and productive. The prepared questions that were given to each RE in advance of the workshop served to help elicit information and perspectives that were directly relevant to the project. The PPRP observed that all the TI Team members contributed by asking questions and sustaining discussions with the REs. As appropriate, members of the support staff were also directly involved in the discussions. This high level of active participation on the part of the Project personnel is viewed by the PPRP as an important indication of a healthy intellectual interaction within the Project Team. The presentation of the previously developed SSHAC-Levcl-2 "Base Case" SSC model was effectively used to establish a knowledge base upon which the REs contributions could be considered. The sensitivity analyses presented by Melanie Walling were particularly useful during the course of the workshop. For future meetings, it would be useful to check the brightness of the room and the positioning of the projector(s) with respect to the screen(s) to assure that people in the back of the room can see the most detailed slides with reasonable clarity. The PPRP noted that several presenters commented that they had difficulty seeing their own PPRP Letter #3: PVNGS SSC WS l Dr. Ross D. Hartleb 3 FINAL 6/5/13 projected images clearly. It is also the case that some presenters did not have we11-prepared slides regardless of the projection facilities! Specific comments on Significant Issues and Data Needs I. Status or seismicity data for use in the Project. There arc several important uses of seismicity data (the catalog of parameters of located earthquakes) in the SSHAC 3 study for the PVNGS site. including associating earthquakes with geologic structures or zones, and developing statistical models for seismicity within geologically and/or tectonically coherent areas. TI Team Support Staff member John Vlasity summarized the compilation of available scismicity catalogs into a single catalog covering the region within 200 miles of the site for M3 and larger events (M5 and larger in the high-seismicity area west of Arizona). Subsequently, Resource Experts discussed the Northern Arizona Seismic Network (NASN) established in 1986 (David Brumbaugh) and the recent operation of the IR IS Transportable Array (TA) ( 4-2006 to 3-2009) and subsequent transfer of eight TA stations to ongoing operation as the Arizona Broadband Network (ABN) that sparsely covers western and central Arizona (Jeri Young). It was noted that one of the TA stations, which was located several miles west of the PNVGS site, was heavily vandalized and the station has been abandoned. The NASN and ABN are jointly called the Arizona Integrated Seismic Network (AISN). It was clear from the presentations and discussions that earthquake monitoring within Arizona has been given a low funding priority historica11y and is operating in a fragile manner through the dedication of a few individuals. This severe restriction of resources may have led lo operational practices that could have impacted the quality of the data being relied on for catalog development. We suggest that the TI Team consider performing a friendly "quality assurance" review of the earthquake monitoring data analysis procedures used for the ABN and NASN. The national standard for seismic network operations is established by the US Geological Survey's Advanced National Seismic System (ANSS); the seismic networks to the west (California) and north (Nevada and Utah) arc members of ANSS. The PVNGS site is within a part or the Southern Basin and Range Province that is characterized by very low seismicity. For example, within 50 miles of the site, there is only one M3+ event in the current catalog and only one event of M<2 recorded during the three years of the TA operation. We think that it would be useful to further quantify the seismicity rate by searching for recordings of earthquakes that are large enough lo be detected but too small to have enough stations to locate. One could start by looking at the three-year TA database using the nine TA stations roughly centered on the station closest to the PVNGS site. These data could be helpful in providing a more refined subdivision of the seismicity patterns associated with the Southern Basin and Range Province, and thereby used for refining the areal sources used in smoothing seismicity for areal source rates. Some of the initial results for computing rates for area] sources using the base case PPRP Letter #3: PVNGS SSC WS l Dr. Ross D. Hartleb 4 FINAL 6/5/13 model, as discussed by Melanie Walling, were startlingly high given the observed low seismicity within 50 miles of the PNVGS site. In consideration of the limitations of the current earthquake monitoring networks in Arizona, it might be reasonable for Arizona Public Service. on behalf of its PVNGS. to consider installing one or more seismic monitoring stations for specific data targets relating Lo the current project and for future use regarding seismic hazards related to licensing. As noted in the above comments, the paucity of seismic monitoring data in the low-scismicity environment of PVNGS has both positive and negative aspects. Herc arc several possible deployments that could be useful in the short term (the current project) and in the long term (future licensing matters). a. Given the location of surface bedrock within several miles of the PVNGS site, a broadband station comparable to the vandalized TA station could be installed at a reasonably secure location with data telemetered to a central recording site (potentially operated by the AISN). b. Several additional short-period seismographic stations could be installed to form a small array around the central station to improve the detection and location of occurring earthquakes. These data would be used to refine the seismicity model used for areal sources. c. It has been suggested that a strong-motion station be installed within the site perimeter to collect data on kappa for the site. It could be useful to operate similar strong-motion instruments along with the stations described in items (a) and (b) above. These possible seismic monitoring installations would best be considered in the context of both the near-term application of the data for the current project (a few years) and the longer-term interests of APS with regard to the role of seismic issues in future operational considerations at PVNGS. 2. Geologic data on the presence or absence of fault sources within 40 km of the PVNGS site. Although the PPRP has not seen a specific discussion of the site geology. it's clear that the existing geologic database, in terms of published geologic mapping, is variable in quality, scale (i.e., 1 :24,000 to 1 :250.000 scale), and distribution. There is no modern detailed map of the site and surrounding region. such as a 40 km radius. but it would be a valuable addition to the study in that it would help determine the presence or absence of fault sources within 40 km of the PVNGS site. Such a map could be constructed using existing source maps, such as the Wintersburg 7.5' quadrangle, and extending the map units out 40 km from the site. This mapping could be based largely on photogeologic interpretation in areas of low-quality reconnaissance mapping. Google Earth imagery provides a valuable, low-cost resource for such mapping, and such mapping would augment the reconnaissance Quaternary fault mapping that Arizona performed some two decades ago. Without a map showing the detailed Quaternary geology of the region. it will be difficult to preclude the presence or absence of capable fault sources. An example of the value of such mapping is the near-site faults mentioned in the field trip report PPRP Letter #3: PVNGS SSC WS 1 Dr. Ross D. Hartleb 5 FINAL 6/5/13 CPPRP Letter #2). The detailed Quaternary geologic map in the Wintersburg 7.5' quadrangle shows that the mapped bedrock faults, which trend beneath the PVNGS site, do not disturb Quaternary alluvial units of middle Pleistocene age (hundreds of thousands of years old), and thus show no evidence of young activity. Please contact us if you wish further discussion of any of our observations and comments. Sincerely yours, Dr. William U. Savage (Chair) Mr. Michael N. Machette Dr. Thomas K. Rockwell PPRP Letter #3: PVNGS SSC WS I To: From:

Subject:

Dear Sirs,

William Savage (Participatory Peer Review Panel (PPRP) chair) Michael Machette (PPRP member) Thomas Rockwell (PPRP member) William Lett is (Project Technical Integrator (PTI)) July 15, 2013 Scott Lindvall (Seismic Source Characterization (SSC) Technical Integrator (Tl) Team Lead) Ross Hartleb (Lettis Consultants International (LCI) Project Manager) Response to observations and comments from the PPRP on Workshop #1 Palo Verde Nuclear Generating Station (PVNGS) Seismic Hazard Evaluation Project Senior Seismic Hazard Analysis Committee (SSHAC) Level 3 SSC This letter provides our response to observations and comments from the PPRP's Letter No. 3 dated June 5, 2013 on the PVNGS SSC Workshop #1 ("Significant Issues and Data Needs"), which was held on April 9-10, 2013. We appreciate the PPRP's thoughtful review of both the SSHAC process and the technical issues presented at Workshop #1. The PPRP's Letter No. 3 includes both general observations and specific comments on Workshop #1, some of which contain underlined passages. As requested by the PPRP, we provide in this letter our responses to the underlined portions of the PPRP's observations and comments. General Observations PPRP General Observation: "For the purpose of improving the collegiality and communication during the Workshop, it would have been helpful to have been provided brief bios (name and titles, organization, technical area of interest, role in the project) for each of the meeting participants so that each participant could more quickly establish an intellectual and conversational relationship with his or her peers. It would also be helpful for future meetings to provide name tents for the table for each individual. Name tags should have the preferred nickname of the individual and project role or home organization." Response: The Tl Team concurs with this general observation and will implement these helpful suggestions at future workshops. PPRP General Observation: "For future meetings, it would be useful to check the brightness of the room and the positioning of the projector(s) with respect to the screen(s) to assure that people in the back of the room can see the most detailed slides with reasonable clarity. The PPRP noted that several presenters commented that they had difficulty seeing their own projected images clearly." Page 1of4 Response to observations and comments from the PPRP on Workshop #1-July 15, 2013 Response: The Tl Team concurs with this general observation and will take the recommended steps to ensure improved visibility and legibility of presentations at future workshops. Specific Comments PPRP Comment #1.1: "It was clear from the presentations and discussions that earthquake monitoring within Arizona has been given a low funding priority historically and is operating in a fragile manner through the dedication of a few individuals. This severe restriction of resources may have led to operational practices that could have impacted the quality of the data being relied on for catalog development. We suggest that the Tl Team consider performing a friendly "quality assurance" review of the earthquake monitoring data analysis procedures used for the ABN and NASN. The national standard for seismic network operations is established by the US Geological Survey's Advanced National Seismic System {ANSS); the seismic networks to the west {California) and north {Nevada and Utah) are members of ANSS.11 Response to PPRP Comment #1.1: To the extent possible, the Tl Team will perform the recommended "friendly quality assurance review" of the data analysis procedures of the Arizona Broadband Network (ABN) and the Northern Arizona Seismic Network (NASN), which collectively comprise the Arizona Integrated Seismic Network (AISN). To our knowledge, operational procedures for these networks are not published and are not readily available. The Tl Team will contact Jeri Young (Arizona Geological Survey) and David Brumbaugh (Northern Arizona University) to see if such procedures are available for the ABN and NASN, respectively, for Tl Team review. The Tl Team will use this information to evaluate quality and uncertainty of the data to inform our judgment when weighting alternatives in the SSC, but will not evaluate earthquakes in those earthquake catalogs. PPRP Comment #1.2: "We think that it would be useful to further quantify the seismicity rate by searching for recordings of earthquakes that are large enough to be detected but too small to have enough stations to locate. One could start by looking at the three-year TA database using the nine TA stations roughly centered on the station closest to the PVNGS site. These data could be helpful in providing a more refined subdivision of the seismicity patterns associated with the Southern Basin and Range Province, and thereby used for refining the areal sources used in smoothing seismicity for areal source rates." Response to PPRP Comment #1.2: Many of the earthquakes recorded in the PVNGS study region during the three-year window of the Transportable Array (TA) have magnitudes that are below the lower magnitude cutoff (Mw 2.7) for inclusion in the project earthquake catalog. The Tl Team agrees, however, that the TA earthquakes may be useful, in particular for evaluating seismicity rates and patterns within the study region and possibly to provide additional information or insights on seismicity rates. As such, the Tl Team will continue to investigate the TA earthquake data to assess alternate ways to capture uncertainty in the SSC. These investigations likely will include sensitivity analyses intended to assess the impacts of various modeling decisions on seismic hazard at the PVNGS site. PPRP Comment #1.3: "In consideration of the limitations of the current earthquake monitoring networks in Arizona, it might be reasonable for Arizona Public Service, on behalf of its PVNGS, to consider installing one or more seismic monitoring stations for specific data targets relating to the current project and for future use regarding seismic hazards related to licensing. As noted in the above comments, the paucity of seismic monitoring data in the low-seismicity environment of PVNGS has both positive and negative Page 2 of 4 Response to observations and comments from the PPRP on Workshop #1-July 15, 2013 aspects. Here ore several possible deployments that could be useful in the short term (the current project) and in the long term (future licensing matters). a. Given the location of surface bedrock within several miles of the PVNGS site, o broadband station comparable to the vandalized TA station could be installed at o reasonably secure location with data telemetered to a central recording site (potentially operated by the A/SN). b. Several additional short-period seismographic stations could be installed to form a small array around the central station to improve the detection and location of occurring earthquakes. These data would be used to refine the seismicity model used for areal sources. c. It has been suggested that a strong-motion station be installed within the site perimeter to collect data on kappa for the site. It could be useful to operate similar strong-motion instruments along with the stations described in items (a) and {b) above. These possible seismic monitoring installations would best be considered in the context of both the term application of the data for the current project (a few years) and the longer-term interests of APS with regard to the role of seismic issues in future operational considerations at PVNGS. 11 Response to PPRP Comment #1.3: The Tl Team agrees that installation of a seismograph or seismographs at or near the PVNGS site would provide useful data both for the current project and for the longer-term interests of Arizona Public Service (APS). Specifically, these data would provide improved earthquake monitoring and reduction of uncertainty on site kappa and other ground motion parameters. The installation of new instrumentation, however, is beyond the scope of the current project. We are in current discussions with APS and Westinghouse Electric Company (WEC) regarding the possibility of obtaining additional budget to install, operate, and maintain this new instrumentation and to determine who would receive and support interpretation of any new data. To maximize benefits to the current project, the Tl Team understands that any new instrumentation should be installed as soon as possible to maximize the number of earthquakes recorded in this low-seismicity environment. PPRP Comment #2: "Although the PPRP has not seen a specific discussion of the site geology, it's clear that the existing geologic database, in terms of published geologic mapping, is variable in quality, scale (i.e., 1:24,000 to 1:250,000 scale), and distribution. There is no modern detailed map of the site and surrounding region, such as a 40 km radius, but it would be a valuable addition to the study in that it would help determine the presence or absence of fault sources within 40 km of the PVNGS site. Such a map could be constructed using existing source maps, such as the Wintersburg 7.5' quadrangle, and extending the map units out 40 km from the site. This mapping could be based largely on photogeologic interpretation in areas of low-quality reconnaissance mapping. Google Earth imagery provides a valuable, low-cost resource for such mopping, and such mapping would augment the reconnaissance Quaternary fault mopping that Arizona performed some two decades ago. Without a map showing the detailed Quaternary geology of the region, it will be difficult to preclude the presence or absence of capable fault sources. An example of the value of such mopping is the near-site faults mentioned in the field trip report (PPRP Letter #2). The detailed Quaternary geologic mop in the Wintersburg 7.5' quadrangle shows that the mopped bedrock faults, which trend beneath the PVNGS site, do not disturb Quaternary alluvial units of middle Pleistocene age (hundreds of thousands of years old), and thus show no evidence of young activity." Response to PPRP Comment #2: Presentations and discussions at Workshop #1 identified Quaternary geologic mapping of the site vicinity (within 40 km of the site) as a data need. The Tl Team agrees that a Quaternary geologic map of the site vicinity would help reduce uncertainty regarding the presence or absence of near-site fault Page 3 of 4 Response to observations and comments from the PPRP on Workshop #1-July 15, 2013 sources, thus providing benefit to the PVNGS Seismic Hazard Evaluation Project. The development of such a map, however, is beyond the scope of the current project. We will discuss with APS and WEC the possibility of obtaining additional budget to produce a Quaternary geologic map of the site vicinity or key portions of the site vicinity. This map would need to be available to the Tl Team well in advance of Workshop #3 for incorporation in the PVNGS SSC. Regardless of whether additional budget is secured for Quaternary geologic mapping of the site vicinity, the Tl Team will evaluate the degree to which the development of a reconnaissance-level Quaternary geologic map is feasible under the current project scope. Likewise, we will follow-up with Resource Expert Philip Pearthree to establish more clearly the degree to which he and others at the Arizona Geological Survey have systematically and thoroughly investigated the site vicinity for the presence or absence of Quaternary-active faults. Closure We appreciate the comments from the PPRP on Workshop #1 and suggestions for improvement to the ongoing Palo Verde Seismic Hazard Evaluation Project. We are incorporating your observations, suggestions, and recommendations into our program to the extent possible. We look forward to seeing you again at Workshop #2 and to sharing with you our additional progress on the project at that time. Sincerely, (JJ,.fi_ kfL William Lettis PTI ,... .... . I I \ \..(-> 1 "1.:: I * \ , .. * * *. , \ Ross Hartleb LCI Project Manager Scott Lindvall SSC Tl Team Lead Page 4 of 4 October 23, 2013 Dr. Ross D. Hartleb LCI Project Manager, Palo Verde NGS Seismic Hazard Evaluation Project Lettis Consultants International, Inc. 27441 Tourney Road, Suile 220 Valencia, CA 91335

SUBJECT:

Seismic Source Characterization Participalory Peer Review Panel Lener No. 4: Palo Verde Nuclear Generating Station Seismic Hazard Evaluation Project, Workshop No. 2: Alternative Interpretations

Dear Dr. Hartleb:

This letter provides the report of the Seismic Source Characterization (SSC) Participatory Peer Review Panel (PPRP) on the Palo Verde Nuclear Generating Station (PVNGS) Seismic Hazard Evaluation Project Workshop No. 2 (WS2). The workshop was held on September 24-25, 2013, at the conference facilities of the Wigwam Resort in Litchfield Park, AZ. WS2 is identified as Task 6 in the current version of the SSC Project Plan, daled February 19, 2013, and the goals of this workshop are prescribed in Section 4.6.2 of NUREG-2117. In accord with these guidance documents, the PPRP attended WS2 as observers during the daily proceedings of the two-day workshop to become informed by the presentations and discussions, and to review both the technical and procedural aspects of the workshop. All three members of the PPRP (M. Machelle, T. Rockwell, and W. Savage) attended WS2 and observed all aspects of the workshop. The PPRP met at the end of each day with the TI lead, Tl Team members, and Sponsor representative to provide verbal commenls that could be used during the course of the ongoing workshop and in preparing this letter report. The PPRP appreciated the preparations for and conduct of the workshop in terms of the hospilalily and professionalism of the Sponsor and the Project Team and their staff. The well-planned agenda for the technical presentations and discussions was efficiently followed and led to successful execution of the full agenda of the workshop. The comfortable facilities and attentive staff of the Wigwam Resort also contributed to the effectiveness of the workshop. The PPRP noted lhal suggested improvemenls in the logistics of the meeting having to do with the meeting room layout, improving the visibility of the projection screens, and providing table-top name placards and a list containing brief summaries of professional backgrounds of the participants were very satisfactorily accomplished. In the opinion of lhe PPRP, W. Lellis efficienlly and engagingly presented the training on SSHAC methodology and workshop rules using a revised format. PPRP Letter #4: PVNGS SSC WS2 Dr. Ross D. Hartlcb 2 Final 10/23/13 The PPRP's general observations as well as specific comments and recommendations arc provided in the remainder of this letter report. Those parts of the comments that require a wrillen response from the TI Team are underlined for clarity. General Observations Regarding the Workshop Process The agenda for Lhe technical portion of the workshop began with a sel or presentations by the TI Team that focused on the key technical issues of the SSHAC Level 3 Seismic Source Characterization. This information was particularly useful for informing the new Proponent Experts (PEs) attending the workshop. The PPRP was pleased to see well-focused presentations that covered the entire range of alternative views. The Tl team did an excellent job of selecting the PEs to achieve the observed diversity of interpretations. The provision of targeted questions to the PEs worked very well to focus Lheir comments, and the PEs explicitly responded Lo these questions, in some cases by including them in their presentations; this enabled the TI team to have documentation of the responses. There were three excellent talks on geodesy Lhat elucidaled the discrepancy between geologic and geodetic crustal deformation rates, which are an important component of this project. The geodetic model presented by R. Bennett places most or all of the active deformation in the Transition Zone to the east of the southern Basin and Range, whereas the olhers show the geodelic deformation more as a strain gradient. Resolution of current geodetic rates and their rectification with the lack of geologic expression of deformation. and whether the current rates arc a transient feature in the strain field, arc both issues critical to the correct assessment of hazard. Toward that end, the documentation of unfaulted old piedmont surfaces in the sile vicinity ( 40 km radius) will be critical in demonstrating the absence of the potential for faulting in the site vicinity. as discussed below. Specific Comments on Significant Issues and Data Needs The assessment of the potential for surface faulting in the site vicinity can be efficiently addressed by documenting the locations and extents of older geomorphic piedmont remnants in the landscape. Specifically, targeted mapping of paleosurfaces with slrong soil development (Stage III and stronger CaC03 morphology) will demonstrate the significant age (105 years and older) of surfaces that can then be interrogated for the presence of fault scarps and other signs of deformation. Documentation of the absence of fault-relaled features is direct evidence that Lhese ancient surfaces have not suslained surface rupture in at least I 00,000 years and therefore demonstrates the absence of active faults in the site vicinity that could potentially affect the PVNGS in the future. LCI should be complimented on pursuing evidence for large surface faulls within the 400 km site radius that transects northern Mexico. This study using Google Earth is an efficient way to augment sparse data. However, the PPRP recommends that this type of reconnaissance be extended into southern Arizona within the 400-km radius. The existing PPRP Letter #4: PVNGS SSC WS2 Dr. Ross D. Hartlcb 3 Final 10/23/13 fault mapping in this region of Arizona was conducted in the early 1980s using I: 110,000-scale U2 photographs, in which the scale may limit detection of active faults. A modern landscape analysis and search for potentially active seismic sources, using the Google Earth platform, would assure that there are not additional unmapped seismic sources that may potentially affect PVNGS operations. Proposals for Additional Work Although potential additional work was mentioned only briefly during the formal workshop, the PPRP met subsequently with the Tl team to discuss the status of planned proposals to APS for additional work. The PPRP Letter #3 dated 6/5/13 commented on two areas of data needs regarding (1) improving near-regional seismicity monitoring, and (2) collecting field geologic data for constraining the presence of active faults within the site vicinity (a radius of 40 km). In addition, we understand that additional data collection for refining the site response in the sedimentary materials beneath the plant site is being considered for the site ground motion characterization.

• Quaternary geology and mapping: This proposal focuses on improving the detailed geology of the site area (5 miles/8 km radius) and making a reconnaissance map (25 miles/40 km radius) of the old landforms (piedmont surfaces and bedrock pediments) that provide a basis for precluding the presence of faulting in the past l 00,000 years or more. These basic geologic data are critical for determining whether there are faults capable of generating strong ground motion near the site.
• Seismicity monitoring: This proposal focuses on procuring and installing new broadband and strong-motion instrumentation at the PVNGS site in a borehole drilled for this purpose to bedrock, a depth of about 500 feet beneath the site. The purpose of the instrumentation is to collect data for (I) detection and improved location of earthquakes (-Ml and larger events) in the central part of the southern Basin and Range province including near the Palo Verde site, and (2) refining the value of kappa at the site using primarily weak ground motions from local or regional earthquakes. The instrumentation would be operated initia11y as a freestanding system recording in a triggered mode, prior to establishing more permanent power and Internet data communications for longer-term operation.
• Obtaining additional subsurface geotcchnical site-response information on the shallow velocity structure beneath the power plant: This proposal intends to conduct borehole and downhole Vs data collection prior to the installation of earthquake monitoring instrumentation in the borehole. The PPRP endorses and strongly supports the funding and implementation of these work items as soon as possible. APS has indicated that funding may be available for new work if it is well justified. The PPRP urges that a high priority be placed on implementing these work items at the earliest possible dates in order that the data may be obtained in a timely manner. For example, the new geologic mapping should be completed and PPRP Letter #4: PVNGS SSC WS2 Dr. Ross D. Hartlcb 4 Final 10/23/13 reviewed by the PPRP prior to Workshop No. 3, which is scheduled in February 2014. We assume that the GMC PPRP is independently reviewing the site response and other ground-motion aspects of the proposals for additional work. Conclusions The PPRP considers that Workshop No. 2 was a highly successful meeting where alternative SSC views and models were presented and discussed, thus providing the basis to proceed with the SSC model development, as required by the SSHAC process. Please contact us if you wish further discussion of any of our observations and comments. Sincerely yours, ;1* / . -. .,,: J*' . "' -.J.:* "-*/ ,.., _ _..,._,,,, "?--* , .. * '-:,.. * -s--./ Dr. William U. Savage (Chair) Mr. Michael N. Machette Dr. Thomas K. Rockwell (-' PPRP Letter #4: PVNGS SSC WS2 To: From:

Subject:

Dear Sirs,

William Savage (Participatory Peer Review Panel (PPRP) chair) Michael Machette (PPRP member) Thomas Rockwell (PPRP member) William Lett is (Project Technical Integrator (PTI)) November 26, 2013 Scott Lindvall (Seismic Source Characterization (SSC) Technical Integrator (Tl) Team Lead) Ross Hartleb (Lettis Consultants International (LCI) Project Manager) Response to observations and comments from the PPRP on Workshop #2 Palo Verde Nuclear Generating Station (PVNGS) Seismic Hazard Evaluation Project Senior Seismic Hazard Analysis Committee (SSHAC) Level 3 SSC This letter provides our response to observations and comments from the PPRP's Letter No. 4 dated October 23, 2013 on the PVNGS SSC Workshop #2 ("Alternative Interpretations"), which was held on September 24-25, 2013. We appreciate the PPRP's thoughtful review of both the SSHAC process and the technical issues presented at Workshop #2. The PPRP's Letter No. 4 includes both general observations and specific comments on Workshop #2, some of which contain underlined passages. As requested by the PPRP, we provide in this letter our responses to the underlined portions of the PPRP's observations and comments. General Observations PPRP General Observation: "Resolution of current geodetic rates and their rectification with the lack of geologic expression of deformation, and whether the current rates are a transient feature in the strain field, are both issues critical to the correct assessment of hazard. Toward that end, the documentation of unfaulted old piedmont surfaces in the site vicinity (40 km radius) will be critical in demonstrating the absence of the potential for faulting in the site vicinity, as discussed below." Response: The Tl team acknowledges the potential importance of, and the uncertainty associated with, geodetic data for the Palo Verde region. The question of how to incorporate geodetic data into the SSC will be carefully investigated and debated by the Tl team. Additionally, the Tl team will continue to engage Proponent Experts Richard Bennett (University of Arizona), Peter Bird (University of California at Los Angeles), Cornelius Kreemer (University of Nevada at Reno), and others to further explore the utility and limitations of geodetic data from the site region. As described below, newly proposed Quaternary geologic mapping of the site area (8 km radius) and reconnaissance-level Quaternary mapping of the site vicinity (40 km radius) will be used to evaluate the presence or absence of Quaternary surface faulting in the vicinity of the PVNGS. Page 1of3 Response to observations and comments from the PPRP on Workshop #2 -November 26, 2013 Specific Comments PPRP Comment #1: "The PPRP recommends that this type of reconnaissance be extended into southern Arizona within the 400-km radius." Response to PPRP Comment #1: The Tl team agrees that it is important to perform a level fault screening study for Arizona to assess whether there is evidence for capable fault sources in the PVNGS region that are not included in the current base-case SSC model. Thus, the Tl team will perform a screening study for large surface faults within the Arizona portion of the site region. Similar to the fault screening performed for northern Sonora and described at Workshop #2, the Tl team's new fault screening for Arizona largely will be based on Google Earth imagery, but also will utilize other data sets where available (e.g., the limited lidar data available for the Arizona-Mexico border area). Unlike the Sonora fault screening, the new Arizona fault screening will build on available data like the U.S. Geological Survey's Quaternary fault and fold database and the draft update to that database provided to the Tl team by Philip Pearthree (Arizona Geological Survey). A major benefit of this new fault screening is that it will bring the entire SSC model region closer to a common state of knowledge. PPRP Comment #2: "The PPRP endorses and strongly supports the funding and implementation of these work items as soon as possible.11 Response to PPRP Comment #2: Arizona Public Service (APS), LCI, and the Tl team are working together to implement three newly proposed work items, including Quaternary geologic mapping in the site area and site vicinity, installation of a down hole seismograph array at the site, and collection of Spectral Analysis of Surface Waves (SASW) data at the site. In a recent teleconference with LCI, APS indicated their intention to fund the three new proposals. During that call, however, APS indicated that funding for the new work largely will not be available until early in 2014, with the exception that procurement of seismograph instrumentation is underway so that it will be available for installation as early as possible in 2014. PPRP Comment #3: '7he PPRP urges that a high priority be placed on implementing these work items at the earliest possible dates in order that the data may be obtained in a timely manner. For example, the new geologic mapping should be completed and reviewed by the PPRP prior to Workshop No. 3, which is scheduled in February 2014. We assume that the GMC PPRP is independently reviewing the site response and other ground-motion aspects of the proposals for additional work.11 Response to PPRP Comment #3: As described above, APS, LCI and the Tl team are working together to implement the newly proposed work items as soon as possible. Field review by the PPRP of the new geologic mapping activities is planned for early February, 2014. It is anticipated that mapping activities will be ongoing at that time, thus allowing for input from the PPRP to be considered prior to finalization of mapping. Workshop #3 is postponed from February until April to allow additional time for the project team to complete newly proposed activities, especially the geologic mapping, and to incorporate this new information into the SSC. LCI has provided its SASW and seismograph array proposals to Carola DiAlessandro, Project Manager for the Southwestern United States Ground Motion Characterization (SWUS GMC) project, for their information. Closure We appreciate the comments from the PPRP on Workshop #2 and suggestions for improvement to the ongoing Palo Verde Seismic Hazard Evaluation Project. We are incorporating your observations, Page 2 of 3 Response to observations and comments from the PPRP on Workshop #2 -November 26, 2013 suggestions, and recommendations into our program to the extent possible. We look forward to seeing you again at Workshop #3 and to sharing with you our additional progress on the project at that time. Sincerely, k:fk* William Lettis PTISSC , '* . ... '., Ross Hartleb LCI Project Manager Page 3 of 3 Scott Lindvall Tl Team Lead March 26, 2014 Dr. Ross D. Hartleb LCI Project Manager, Palo Verde NGS Seismic Hazard Evaluation Project Lettis Consultants International, Inc. 27441 Tourney Road, Suile 220 Valencia, CA 91335

SUBJECT:

Seismic Source Characterization Participalory Peer Review Panel Lener No. 5: Palo Verde Nuclear Generating Station Seismic Hazard Evaluation Project, Field Review of Geologic Mapping

Dear Dr. Hartleb:

This letter constitutes the report of the Participatory Peer Review Panel (PPRP) on the Palo Verde Nuclear Generaling Station (PVNGS) Seismic Hazard Evaluation Project's 2.5-day Field Review of Geologic Mapping. The Field Review was held on February 4-6, 2014, at the conference facilities of the Wigwam Resort in Litchfield Park, AZ and at selected field localities within about 60 km of the PVNGS site. The work to be reviewed was recommended by the PPRP in our Lener No. 4 daled October 19, 2013. The scope of work suggested by the PPRP was as follows:

• Quaternary geology and mapping: This proposal focuses on improving the detailed geology of the site area (5 miles/8 km radius) and making a reconnaissance map (25 miles/40 km) of the old landforms (piedmont surfaces and bedrock pediments) that provide a basis for precluding the presence of active faulting. These basic geologic data are critical for determining whether there are faults capable of generating strong ground motion near the sile. The scope of work approved by Arizona Public Service is included in the Project Plan for Quaternary Geologic Mapping in the Vicinity of the Palo Verde Nuclear Generating Station, prepared by LCI and daled March 3, 2014. The PPRP received a draft version of this Project Plan for review and discussion during the February 4-6 Field Review. The PPRP finds that the March 3, 2014, Project Plan is a satisfactory response to the PPRP's suggested scope of work. Those parts of these comments that require a written response from the TI Team are underlined for clarity. It was our understanding that the purpose of the Field Review was to provide early feedback to the PVNGS Project management and the personnel performing the field investigations. The decision by PVNGS to proceed with the above scope of work reflects well on their commitment to achieve a robust and state-of-the-art understanding of potential seismic hazards within relatively close proximity to the PVNGS site. PPRP Letter #5: PVNGS SSC Field Review Feb 4-6, 2014 Dr. Ross D. Hartlcb 2 FINAL 3/26/14 The personnel listed in the Project Plan arc experienced and knowledgeable about the regional geology and its faults and their activity. and the PPRP is confident that they possess Lhe skills to carry oul the projecl successfully. These individuals consist of: LCI Project Manager and Senior Geologist Ross Hartleb LCI Senior Principal Geologist Scott Lindvall LCI Senior Project Geologist Richard Ortiz In addition, LCI has engaged consultants that are specifically knowledgeable about the project area, having worked in the region for years. These individuals arc: Philip Pearthree, Arizona Geological Survey, Senior Research Geologist, Jeri Young, Arizona Geological Survey, Senior Research Geologist Results of the Field Review LCI personnel and their consultants conducted a two-day field review that focused on techniques for differentiating ages of Quaternary units and afforded us the opportunity to inspect the project area and visit two key fault localities. During and immediately following the Field Review, the PPRP discussed with the LCI personnel and consultants the various aspects of the procedures to be used to conduct the new work. These comments and discussions were used by LCI to finalize the March 3, 2014, Projecl Plan. Day I (February 4): The focus of this day's field review was the explanation and demonstration of the procedures used to assess the age of Quaternary deposits within the 40-km radius (site vicinity) from the PNVGS site. Geologist Pearthree explained the observational approach and criteria that he and others have been using in the AZGS for detailed mapping in the Phoenix region. We visited a half-dozen sites in the Wintersburg 7.5-minute quadrangle (location of the PVNGS) to familiarize ourselves with soils on these deposits and their characteristic landforms, which will be used in the 8-km-and 40-km-radius mapping efforts. Particularly enlightening were the strong development of calcic soils on older deposits and surfaces. which will be the focus of defining I 00 ka and older landforms. The PPRP members were impressed by the effectiveness of the qualitative criteria used by Pearthree and Young to rapidly and confidently assess the ages of the surfaces at each locality. The PPRP felt that the procedure used and the nomenclature developed to classify the Quaternary deposits at each locality were based on established and defcndablc geomorphic and soil criteria and would be accepted by peers in the greater technical community. Day 2 (February 5, first stop): With the background from the first day, the LCI personnel and consultants escorted the PPRP to two fault localities where faults had been previously identified. At the first locality, about 60 km SSE of the PVNGS sile, the characteristics of the Sand Tank fault were discussed, including discussion of the trenching work that had been carried out previously by Dr. Pearthrcc and others. Procedures and technologies associated with detecting surface fault ruptures at other PPRP Letter #5: PVNGS SSC Field Review Feb 4-6, 2014 Dr. Ross D. Hartlcb 3 FINAL 3/26/14 localities in the site vicinity were discussed, with particular reliance on imagery available on Google Earth. The PPRP felt confident that the strategy of using Google Earth imagery combined with expertise in the kinds of features associated with surface fault rupture (chiefly long-term changes in the pattern of sediment removal or accumulation following the formation of fault scarps) was well understood by the Project personnel and consultants and would provide a high degree of confidence in being able to either demonstrate the existence of previously unidentified surface fault ruptures or demonstrate the absence of such faulting within the study region surrounding the PVNGS site. Day 2 (February 5, second stop): At this stop, the PPRP were taken to the location of the unnamed east-west-trending fault that was mapped by Gilbert (199 l) as a bedrock fault located west of the Gila River valley and suspected of being active. The group hiked along much of the discontinuously exposed trace of the fault and discussed evidence of its location and possible recency of activity. In this brief review, no evidence was found suggesting any recent (Quaternary) activity, but further study using the techniques discussed at the first stop was thought to be applicable to the two ends of the fault trace that trend beneath sediments, and within the 40-km-radius site vicinity. The PPRP considers this procedure to be an appropriate way to assess the potential for future activity by this and other known bedrock faults within the site vicinity. Day 3 (February 6, morning): The PPRP met with the LCJ personnel to briefly discuss the methodology used and the observations made during the Field Review. The PPRP met separately to discuss our observations and conclusions. Conclusions The PPRP is satisfied that the additional fieldwork has been planned in a scientifically sound manner with appropriate investigative procedures and well-qualified individuals performing the work. Because this Field Review was held prior to the completion of the planned field investigations. the PPRP recommends that additional time be allocated just before or during Workshop 3 for a detailed presentation of the results of the completed Quaternary Geologic Mapping as applied to evaluating the possible presence and seismic potential of as-yet unidentified active faults within 40 km of the PVNGS site. We also acknowledge the expertise and experience of all the members of the Field Review team, and expect that the results of the Quaternary Geologic Mapping study will be a valuable contribution to the Probabilistic Seismic Hazard Assessments for the Palo Verde Nuclear Generation Station. Please contact us if you wish further discussion of any of our observations and comments. PPRP Letter #5: PVNGS SSC Field Review Feb 4-6, 2014 Dr. Ross D. Hartlcb Sincerely yours, Dr. William U. Savage (Chair) Mr. Michael N. Machette Dr. Thomas K. Rockwell

Reference:

4 FINAL 3/26/14 Gilbert, W. G. ( 1991). Bedrock Geology of the Eastern Gila Bend Mountains, Maricopa County, Arizona; Arizona Geological Survey, Open-File Report 91-5. PPRP Letter #5: PVNGS SSC Field Review Feb 4-6, 2014 To: From:

Subject:

Dear Sirs,

William Savage (Participatory Peer Review Panel (PPRP) chair) Michael Machette (PPRP member) Thomas Rockwell (PPRP member) Ross Hartleb (Lettis Consultants International (LCI) Project Manager) March 26, 2014 Scott Lindvall (Seismic Source Characterization (SSC) Technical Integrator (Tl) Team Lead) Response to comment from the PPRP on field review of geologic mapping Palo Verde Nuclear Generating Station (PVNGS) Seismic Hazard Evaluation Project Senior Seismic Hazard Analysis Committee (SSHAC) Level 3 SSC This letter provides our response to the PPRP's Letter No. 5 dated March 26, 2014 on their field review of Quaternary geologic mapping in the vicinity of the PVNGS. On February 4-6, 2014, the PPRP joined geologists from Lettis Consultants International, Inc. (LCI) and the Arizona Geological Survey (AZGS) to provide early feedback regarding mapping activities that support development of the PVNGS SSC. We appreciate the PPRP's active participation in the field review and their thoughtful comments. The PPRP requested that we respond to one comment in their Letter No. 5. That comment, along with our response, is provided below. PPRP Comment: "Because this Field Review was held prior to the completion of the planned field investigations, the PPRP recommends that additional time be allocated just before or during Workshop 3 for a detailed presentation of the results of the completed Quaternary Geologic Mapping as applied to evaluating the possible presence and seismic potential of as-yet unidentified active faults within 40 km of the PVNGS site." Response: We agree that a detailed presentation and discussion of the results of the Quaternary geologic mapping is warranted. During Workshop #3, we will present an overview of mapping procedures, results, and incorporation into the SSC. If there is interest on the part of the PPRP, we would be happy to hold a more-detailed discussion of the mapping results in the evening following the first day of the workshop, or at another time that is mutually convenient. We appreciate the comments from the PPRP on our Quaternary geologic mapping activities. We look forward to seeing you again at Workshop #3 and to sharing with you our additional progress on the project at that time. Sincerely, l) 1". \ .. \ L v * .\ \ J I). J Ross Hartleb Scott Lindvall May 9, 2014 Dr. Ross D. Hartleb LCI Project Manager, Palo Verde NGS Seismic Hazard Evaluation Project Lettis Consultants International, Inc. 27441 Tourney Road, Suile 220 Valencia, CA 91335

SUBJECT:

Seismic Source Characterization Participalory Peer Review Panel Lener No. 6: Palo Verde Nuclear Generating Station Seismic Hazard Evaluation Project, Workshop No. 3: Preliminary Model and Hazard Feedback

Dear Dr. Hartleb:

This letter provides the report of the Participatory Peer Review Panel (PPRP) on the Palo Verde Nuclear Generating Station (PVNGS) Seismic Hazard Evaluation Project Workshop No. 3 (WS3). The workshop was held on April 23-24, 2014, at the conference facilities of the Marriott Hotel in Walnut Creek, CA. WS3 is identified as Task 8 in the cun-enl version of lhe SSC Project Plan, dated February 19, 2013, and the goals of this workshop are prescribed in Section 4.6.3 of NUREG-2117. In accord with these guidance documents, the PPRP attended WS3 as participants in the discussion of the preliminary SSC model in order to provide feedback to the evaluator experts regarding the manner in which the views of the larger lechnical community have been considered and the range of technically defensible interpretations included. A draft of the Hazard Identification Document (HID) was provided in advance of the workshop. The three members of the PPRP (M. Machecte, T. Rockwell, and W. Savage) attended both days of WS3 and observed and commented during all aspects of the workshop. The PPRP met at the end of each day with the TI Lead, Tl Team members, and the Sponsor representative to provide verbal comments that could be used during the ongoing workshop and in preparing this letter report. General Observations Regarding the Workshop Process The PPRP appreciated the efforts taken by the Tl Team and LCI personnel to prepare for and conducl WS3 in an efficient and highly professional manner. The agenda was thoughtfully planned and resulted in a comprehensive and on-time meeting. The workshop facilitators, Ross Hartleb and Scott Lindva11, were particularly effective in facilitating the various elements of the agenda to assure opportunities for thorough discussions and lo stay on the planned schedule for the two-day meeting. The PPRP members appreciated the seating an-angement for the meeting that placed the PPRP and TI Team leaders on opposite sides of the conference table and close to the projection screen. This arrangement assured that the PPRP members had a clear view of the PPRP Letter #6: PVNGS WS3 April 23-24, 2014 Dr. Ross D. Hartlcb 2 FINAL 5/9/14 PowerPoint figures and could interact with the TI Team leaders efficiently and directly. The individual speakers from the Tl Team were well prepared in delivering their presentations and were responsive to questions and comments from the PPRP members. Complex elements of the presentations (particularly the smoothing and completeness analyses discussed by G. Toro and the preliminary hazard and sensitivity analyses discussed by M. Walling via teleconference call) led to some extensive Q&A discussions, which the PPRP members found very informative. The PPRP observed that there arc several studies and analyses that may be on completion schedules that could impact the timely completion of the project. The PPRP recommends that the TI team prepare a complete schedule of planned meetings and due dates for all products (including reports. analyses. data catalogs, reviews, etc.). and provide a clear identification of how all the products link together to form the documentation of the HID and the PSHA final report. In this schedule, the PPRP members need to be advised as soon as possible when their future participation would be requested in terms of time windows within which document reviews, meeting attendance, and delivering written responses would be requested. Specific Comments on Significant Issues The PPRP has provided the following specific comments. Of these, the ones for which the PPRP would like to receive written responses are underlined. The PPRP would also appreciate a response regarding the schedule for completion identified in the previous paragraph. l. The PPRP acknowledges the detailed and comprehensive nature of the extensive compilation of "Points of Interest" and "Action Items" recorded for WS3 that was prepared by Scott Lindvall. Addressing these items will significantly improve the source characterization. The following PPRP comments address some of the action items that we feel need additional emphasis or specificity. We assume that all of the Action Items will be addressed by the TI Team during the finalization of the HID and the associated Seismic Source Characterization report preparation and documentation. 2. The incorporation of geodetic data in the hazard analysis appears to be incomplete at present. The PPRP suggests that a written plan be prepared and implemented as soon as possible for identifying (1) the relevant geodetic data set(s) to be considered and (2) how the geodetic data contribute to characterizing seismic hazard. Such contributions may result in changes to the HID. 3. During the meeting, Gabriel Toro discussed the analysis of uncertainty in using seismicity data for expressing seismic hazard in substantial detail, which proved to be quite informative. Preparation of a succinct narrative and more complete documentation of the analytical tool called "smoothing" during the meeting should be considered so that reviews of the analyses can be carried out in an informed and efficient manner. PPRP Letter #6: PVNGS WS3 April 23-24, 2014 Dr. Ross D. Hartleb 3 FINAL 5/9/14 4. Some uncertainty in the nature of the M>4.65 seismic events mapped on the west side of the Southern Basin and Range province just east of the Gulf of California was noted in the meeting. Conducting a review of the earthquakes comprising these events should be considered to determine if they are located on land or are associated with faulting within the Gulf. If they arc pre-instrumental (or otherwise poorly located), efforts could be made to reposition the events. 5. The nature of the observed surface displacements on the Sand Tank fault should be considered to assess the observations in terms of average and/or maximum fault displacement values. Comparisons could he made with historic normal fault ruptures with detailed displacement envelopes (e.g., 1959 Hebgen Lake, 1983 Borah Peak, etc.) to determine an average offset if the maximum is roughly 2 m. In addition, Phil Pearthree could be asked whether the scarp profiles measured across the fault arc long enough to detect far-field deformation. Such information could be gathered easily using modem precision GPS instrumentation. 6. The two-zone model for areal seismic sources may be unrealistic based on the level of geologic data that are available, and thus its usefulness should be reconsidered. The positions of zone boundaries in the seven-zone model could be reexamined to include a possible extension of the transition zone to the west to include faults and seismicity that arc concentrated between the 320-and 400-km radii. Similarly, we sec no reason not to absorb the ETR zone into the SCABA zone as discussed at the Workshop. This would result in a new 6-zone model that would be either the only model or the dominantly weighted model. 7. As part of the detailed Quaternary mapping fault studies for the site vicinity, the potential for Quaternary active faults located within the modern alluvial drainages should be considered. The north-south continuity of many of the surficial deposits provide valuable datums for excluding perpendicular (E-W) faults, but one could argue that significant (I 0-20 km long) N-S oriented faults could lurk beneath major river channels and their adjacent Holocene deposits. Conclusions The PPRP considers Workshop No. 3 to have been a successful forum for presenting the PVNGS Preliminary hazard model and generating useful feedback. Dr. William U. Savage (Chair) Mr. Michael N. Machelle Dr. Thomas K. Rockwell PPRP Letter #6: PVNGS WS3 April 23-24, 2014 To: From:

Subject:

Dear Sirs,

William Savage (Participatory Peer Review Panel (PPRP) chair) Michael Machette (PPRP member) Thomas Rockwell (PPRP member) William Lett is (Project Technical Integrator (PTI)) May 14, 2014 Scott Lindvall (Seismic Source Characterization (SSC) Technical Integrator (Tl) Team Lead) Ross Hartleb (Lettis Consultants International (LCI) Project Manager) Response to observations and comments from the PPRP on Workshop #3 Palo Verde Nuclear Generating Station (PVNGS) Seismic Hazard Evaluation Project Senior Seismic Hazard Analysis Committee (SSHAC) Level 3 SSC This letter provides our response to observations and comments from the PPRP's Letter No. 6 dated May 9, 2014 on the PVNGS SSC Workshop #3 ("Preliminary Model and Hazard Feedback"), which was held on April 23-24, 2014. We appreciate the PPRP's thoughtful review of both the SSHAC process and the technical issues presented at Workshop #3. The PPRP's Letter No. 6 includes both general observations and specific comments on Workshop #3, some of which contain underlined passages. As requested by the PPRP, we provide in this letter our responses to the underlined portions of the PPRP's observations and comments. General Observations PPRP General Observation: "The PPRP observed that there are several studies and analyses that may be on completion schedules that could impact the timely completion of the project. The PPRP recommends that the Tl team prepare a complete schedule of planned meetings and due dates for all products (including reports, analyses, data catalogs, reviews, etc.), and provide a clear identification of how all the products link together to form the documentation of the HID and the PSHA final report." Response: The Tl team will prepare and distribute to the PPRP a detailed project schedule. This schedule will clarify when and how PPRP participation is required for document review, attending meetings, delivering written responses, and other key project activities. Specific Comments PPRP Comment #1: "We assume that all of the Action Items will be addressed by the Tl Team during the finalization of the HID and the associated Seismic Source Characterization report preparation and documentation." Response to PPRP Comment #1: The Tl team records action items and key issues identified at each project workshop. During finalization of the SSC model and report, the Tl team will address the action items identified at Workshop #3 and previous project workshops. Page 1of4 Response to observations and comments from the PPRP on Workshop #3 -May 14, 2014 PPRP Comment #2: "The PPRP suggests that a written plan be prepared and implemented as soon as possible for identifying {1) the relevant geodetic data set(s) to be considered and {2) how the geodetic data contribute to characterizing seismic hazard." Response to PPRP Comment #2: Based on the evaluation of data presented in the published scientific literature and at Workshops #1 and #2, the Tl team excluded from the Preliminary SSC model the use geodetic data in calculating rates and identifying seismic sources. The basis for this decision will be further evaluated and documented in detail in the SSC report. PPRP Comment #3: "Preparation of a succinct narrative and more complete documentation of the analytical tools, called "smoothing" during the meeting, should be considered so that reviews of the analyses can be carried out in an informed and efficient manner." Response to PPRP Comment #3: The Tl team acknowledges the hazard significance of the decision to calculate earthquake recurrence parameters for areal source zones using a smoothed seismicity approach. The Tl team also understands that the soothing approach used in the project is a complex procedure that may not be well understood by all readers of the SSC report. For these reasons, a complete and thorough documentation of the smoothing process and assumptions will be provided in the SSC report. PPRP Comment #4: "Conducting a review of the earthquakes comprising these events should be considered to determine if they are located on land or are associated with faulting within the Gulf If they are pre-instrumental (or otherwise poorly located), efforts could be made to reposition the events." Response to PPRP Comment #4: The Tl Team reviewed the portion of the project earthquake catalog directly east of the Gulf of California, where an approximately triangular wedge of seismicity appears to taper off into the Southern Basin and Range. In order to assess the likelihood that: (1) the project catalog correctly reflects a region of elevated seismicity rate along the western border of the Southern Basin and Range; and (2) the catalog correctly locates Mw > 4.65 earthquakes in this region, the Tl Team reviewed the age, location uncertainty, and magnitude type of these earthquakes. Approximately 62 earthquakes in the project catalog are identified in this area. The majority of these earthquakes occurred recently, such that only eight earthquakes occurred prior to 1950. Furthermore, the majority of these earthquakes are based on instrumental data, such that only two earthquakes are reported with intensity-based (MMI) magnitudes. From these observations, the Tl Team assumes that the project catalog correctly reflects a region of elevated seismicity along the western border of the Southern Basin and Range. Most of the earthquakes in the project catalog for this area are minor to moderate in magnitude. Of the 62 earthquakes in the area, only six have magnitudes Mw > 4.65 (i.e., 1935 Mw 5.0, 1952 Mw 5.1, 1958 Mw 4.9, 1963 Mw 4. 7, 1969 Mw 4.8, and 1981Mw4.9). The location and magnitude for the 1935 earthquake are based on felt intensity reports and therefore may be highly uncertain. The locations and magnitudes of the 1952 and 1958 earthquakes are based on instrumental data but are reported only to the nearest half-degree, reflecting a high degree of uncertainty. The Tl team assumes that the more recent 1963, 1969, and 1981 earthquakes are relatively well located, however, and should not be repositioned. Given this assumption, it is difficult for the Tl team to justify repositioning the 1935, 1952, and 1958 earthquakes. Therefore, the Tl team does not plan to reposition any of the earthquakes in this area. Page 2 of 4 Response to observations and comments from the PPRP on Workshop #3 -May 14, 2014 PPRP Comment #5: "The nature of the observed surface displacements on the Sand Tonk fault should be considered to assess the observations in terms of overage and/or maximum fault displacement values." Response to PPRP Comment #5: The Tl team appreciates the discussions with the PPRP regarding observations of the Sand Tank fault scarp height and characterization of the Sand Tank fault source. Demsey and Pearthree (1990) recognize that the zone of deformation for normal faults commonly extends beyond the immediate location of the scarp and, therefore, their estimate of an approximately 2-m-high scarp for the Sand Tank fault is based on fault-normal topographic profiles that were surveyed over distances of approximately 700 m. In the Preliminary SSC model, greater weight is given to the possibility that this scarp height represents average slip in the most-recent earthquake, as opposed to maximum slip. The Tl team will re-evaluate this modeling decision and determine whether greater weight should be assigned to the possibility that the observed scarp height represents maximum coseismic displacement. PPRP Comment #6: "The two-zone model for areal seismic sources may be unrealistic based on the level of geologic data that are available, and thus its usefulness should be reconsidered. This would result in a new 6-zone model that would be either the only model or the dominantly weighted model. 11 Response to PPRP Comment #6: The Tl Team appreciates discussions with the PPRP regarding areal seismic sources. The Preliminary SSC model includes a seven-zone model alternative and a two-zone model alternative. The seven-zone model incorporates a broad range of geologic data to define unique seismotectonic domains that capture differences in expected future rupture characteristics. The zone model simply distinguishes the highly active plate boundary of California and Baja California from the less active areas to the east. The Tl team generally agrees that the geologic data suggest the zone model may be unrealistic, but this alternative is included to capture the range of technically defensible interpretations. Going forward, the Tl team will further evaluate the need for the two-zone alternative. The Tl team agrees that the Eastern Transverse Ranges (ETR) zone is unnecessary, based on discussions with the PPRP and on hazard sensitivity results presented at Workshop #3. The Tl team likely will combine the ETR zone into the adjacent Southern California and Baja (SCABA) source zone. PPRP Comment #7: "As part of the detailed Quaternary mapping fault studies for the site vicinity, the potential for Quaternary active faults located within the modern alluvial drainages should be considered." Response to PPRP Comment #7: Quaternary geologic mapping of the site vicinity is ongoing, but LCI expects to deliver in the near future its mapping report to the Tl team for evaluation. Given the expected distribution and ages of Quaternary deposits across the site vicinity, the Tl team agrees that it may not be possible to preclude the presence of active faults throughout the entire vicinity, especially beneath major river channels and adjacent Holocene deposits. As part of the integration of the mapping data into the SSC model, the Tl team will be mindful of these data limitations. Closure We appreciate the comments from the PPRP on Workshop #3 and suggestions for improvement to the ongoing Palo Verde Seismic Hazard Evaluation Project. We are incorporating your observations, suggestions, and recommendations into our program to the extent possible. We look forward to seeing Page 3 of 4 Response to observations and comments from the PPRP on Workshop #3 -May 14, 2014 you again at Workshop #4 ("Final Briefing") and to sharing with you our additional progress on the project at that time. Sincerely, I f)jj . William Lettis .::::::.*:--1L---* r:.;:.. /. ,// e:-: '---.t t:'. ' Scott Lindvall / PTI SSC Tl Team Lead J ) \'). \ \ t v* \ \ Ross Hartleb LCI Project Manager Page 4 of 4 February 26, 2015 Dr. Ross Hartleb LCI Project Manager, Palo Verde Nuclear Generating Station (PVNGS) Seismic Hazard Evaluation Project Lettis Consultants International, Inc. 27441 Tourney Road, Suite 220 Valencia, CA 91355

Subject:

PVNGS SSHAC Level 3 Seismic Source Characterization

Dear Dr. Hartleb:

On March 12, 2012, the U.S. Nuclear Regulatory Commission (NRC) issued a request for information pursuant to 10CFR50.54(f), requiring that all operating nuclear plants in the U.S. perform a site-specific Probabilistic Seismic Hazard Analysis (PSHA) and develop a Ground Motion Response Spectrum (GMRS) in accordance with Regulatory Guide 1.208 for comparison to the plant license Safe Shutdown Earthquake (SSE) ground motion. Licensees are required to evaluate the seismic hazard using present-day NRC regulatory criteria and guidance. For plants in the western U.S., including the PVNGS, the directive requires that the site-specific PSHA be performed using the Senior Seismic Hazard Analysis Committee (SSHAC1, 2) Level 3 process to develop the Seismic Source Characterization (SSC) model. In accordance with the requirements for a SSHAC Level 3 study, the PVNGS SSC Participatory Peer Review Panel ("PPRP") is pleased to issue this PPRP Closure Letter containing our findings with respect to the PVNGS SSC Project. The PPRP was actively engaged in the review of all phases and activities of the Project's implementation. These phases included development of the Project Plan, planning and execution of the Technical Integration (TI) Team's evaluation and integration activities, and review of the TI Team's documentation of the SSC model. These phases are at the core of the SSHAC process. In accordance with NRC guidance for SSHAC projects, the role of the PPRP is to conduct a review of both the process followed and the technical assessments made by the TI Team. Accordingly, this letter documents the activities that the PPRP has carried out to perform its review of the adequacy of the process followed, and its findings regarding the technical adequacy of the SSC. 1 Budnitz, R.J., G. Apostolakis, D.M. Boore, L.S. Cluff, K.L. Coppersmith, C.A. Cornell, and P.A. Morris (1997). Recommendations for Probabilistic Seismic Hazard Analysis: Guidance on Uncertainty and the Use of Experts [known as the "Senior Seismic Hazard Analysis Committee Report': or "SSHAC Guideline'], NUREG/CR-6372, U.S. Nuclear Regulatory Commission, TIC; 235076, Washington. D.C. 2 USN RC (2012). Practical Implementation Guidelines for SSHAC level 3 and 4 Hazard Studies, NUREG-2117, U.S. Nuclear Regulatory Commission, Washington, D.C. PVNGS SSC PPRP Closure Letter PPRP Activities for the SSC Peer Review The fundamental idea of a participatory peer review process entails the continual review of a project from its start to its completion. Thus, proper participatory peer review requires adequate opportunities during the conduct of the project for the PPRP to understand the data being used, the analyses performed, the TI Team's evaluations and integration of the technical bases for its assessments, and the completeness and clarity of the documentation. Participatory peer review also involves occasions for the PPRP to provide its reviews and comments in written form during the conduct of the project, such that their observations and recommendations can be considered by the TI Team in a timely manner prior to the completion of the project. Written comments by the PPRP serve to document the review process and provide part of the formal record documenting that all aspects of the SSHAC process have been satisfactorily conducted. The activities of the PPRP for the PVNGS SSC are summarized in the table below, which includes written reviews during the various stages of the project. These activities directly addressed the conduct of the PVNGS SSC and the development of the SSC Report. I Date PPRP Activity January 21. 2013 SSC Kickoff Meeting ("Workshop O"); PPRP members attended in person as observers I January 23, 2013 PPRP submitted review comments on the Project Plan via email I April 9-11, 2013 SSC Workshop No. 1: Significant Issues and Data Needs; PPRP members attended in person as observers April 24, 2013 PPRP submitted written review comments on Kick-off Meeting June 5, 2013 PPRP submitted written review comments on Workshop 1 July 10, 2013 TI working meeting No. 4: PPRP members Savage and Machette attend portion of TI working meeting by phone as observers August 27-28, 2013 TI working meeting No. 5: PPRP member Rockwell attends portion of TI working meeting by phone as observer September 24-26, 2013 SSC Workshop No. 2: Alternative Interpretations; PPRP members attended in person as observers October 23, 2013 PPRP submitted written review comments on Workshop No. 2 February 4-6, 2014 Field Review of Geologic Mapping: PPRP members attended in person as observers March 24, 2014 PPRP submitted written review comments of Field Review of Geologic Mapping April 23-25, 2014 SSC Workshop No. 3: Preliminary Model and Hazard Feedback: PPRP members attended in person as active participants PVNGS SSC PPRP Closure Letter 2 I Date PPRP Activity I May 5, 2014 PPRP submitted written review comments on Workshop 3 I June 18, 2014 Update on SSC Activities: PPRP members attended via webinar as observers I July 10-11, 2014 SSC Final Briefing; PPRP members attended in person August 1, 2014 Update on SSC Activities; PPRP representatives attended via webinar as observers I January 12, 2015 Submittal of review comments on SSC Report, transmittal 1 &2 I January 17, 2015 Submittal of review comments on SSC Report, transmittal 3 January 19-22, 2015 Submittal of PPRP written review comments on SSC Report transmittals 1-3 and on Tl Team's responses to PPRP written review comments February 17-19, 2015 Submittal of PPRP written review comments on PVNGS SSC Draft Report transmittal 4 and on Tl Team's responses to PPRP written review comments February 19-25, 2015 Teleconference call to resolve remaining issues with SSC Draft Report (2/19) and review of Tl Team's responses to teleconference call issues I February 26, 2015 Submittal of PVNGS SSC PPRP Closure Letter The activities listed above are those that directly addressed the conduct of the PVNGS SSC and the development of the PVNGS SSC Report. The PPRP has concluded that its ongoing review and feedback interactions with the TI Team during the conduct of the PVNGS SSC Project activities fully met the expectations for a SSHAC Level 3 study. From the presentation of the plans for conducting the PVNGS SSC at the start of the project to the completion of the PVNGS SSC Report, the TI Team provided multiple and effective communications with the PPRP. Webinars and written communications allowed the PPRP to fully understand the technical support for the Tl Team's assessments. The TI Team provided written responses to PPRP comments documenting that all comments had been adequately considered during the conduct of the work and the compilation of its documentation. SSHAC Technical Review The role of the PPRP in the review of the technical aspects of the project is specified in NUREG-2117 (USNRC, 2012) as follows: "The PPRP fulfills two parallel roles, the first being technical review. This means that the PPRP is charged with ensuring that the full range of data, models, and methods have been duly considered in the assessment and also that all technical decisions are adequately justified and documented. PVNGS SSC PPRP Closure Letter 3 The responsibility of the PPRP is to provide clear and timely feedback to the TI/TFI and project manager to ensure that any technical or process deficiencies are identified at the earliest possible stage so that they can be corrected. More commonly, the PPRP provides its perspectives and advice regarding the manner in which ongoing activities can be improved or carried out more effectively. In terms of technical review, a key responsibility of the PPRP is to highlight any data, models or proponents that have not been considered. Beyond completeness, it is not the responsibility of the PPRP to judge the weighting of the logic trees in detail, but rather to judge the justification provided for the models included or excluded, and for the weights applied to the logic-tree branches." Consistent with this USN RC guidance, the PPRP reviewed at multiple times during the project the TI Team's analyses and evaluations of data, models, and methods. These reviews included conference calls, post-workshop meetings, written comments, and the review of drafts of the SSC Report. Through these reviews, the PPRP communicated feedback to the TI Team regarding data and approaches that did not appear to have been considered, suggestions for methods being used within the technical community, and recommendations for ways that the documentation could be improved to include more discussion of the technical bases for the assessments. Examples of PPRP feedback regarding technical aspects of the project can be found in the written comments provided following workshops and field trips and during the review of the draft final report. The Tl Team was responsive to the questions, comments, and suggestions made by the PPRP relative to the technical aspects of the project. Therefore, the PPRP concludes that the technical aspects of the project have been adequately addressed. SSHAC Process Review As explained in NUREG-2117 (USNRC, 2012), the SSHAC process consists of two important activities, described as follows: "The fundamental goal of a SSH AC process is to carry out properly and document completely the activities of evaluation and integration, defined as:

• Evaluation: The consideration of the complete set of data, models, and methods proposed by the larger technical community that are relevant to the hazard analysis.
• Integration: Representing the center, body, and range of technically defensible interpretations in light of the evaluation process (i.e., informed by the assessment of existing data, models, and methods)." These activities are essential to any SSHAC Level study and to both new models and refinements to existing models (such as the PVNGS SSC). During the Evaluation phase of the PVNGS SSC, the TI Team considered new data, models, and methods that have become available in the technical community since the previous PVNGS PSHA PVNGS SSC PPRP Closure Letter 4 projects were completed in 1993 and 2012. In particular, the TI Team incorporated new earthquake occurrence models and carried out additional geologic mapping. The PPRP concluded that the Tl Team conducted a satisfactory evaluation process and that this process has been sufficiently documented in the SSC report. During the Integration phase of the project, an updated SSC model was developed for purposes of the PVNGS PSHA. SSHAC guidelines require that the technical bases for the SSC model be documented thoroughly in the SSC report. The SSC document demonstrates the consideration by the TI Team of the existence of seismic-source data and models that have become available since the previous PVNGS SSC model was developed. During the entire course of the PVNGS Project, The TI Team maintained close coordination with the SWUS ground-motion characterization project to assure that the PVNGS SSC will connect seamlessly with the GMC model. Based on the review of the Evaluation and Integration activities conducted by the TI Team, as well as the documentation of these activities in the SSC report, the PPRP concludes that the SSHAC level 3 process has been adequately conducted. Conclusion Based on its review of the PVNGS SSC, the PPRP concludes that the process and technical aspects of the analysis fully meet accepted guidance and current expectations for a SSHAC Level 3 study. We appreciate the opportunity to provide our review of the project. Sincerely, PVNGS SSC PPRP Members William U. Savage, Chair Michael N. Machette Thomas K. Rockwell . J' J1 /1 < .:*:,1:i **' .. // ,/ .. PVNGS SSC PPRP Closure Letter 5 ATTACHMENT 3 Participatory Peer Review Panel (PPRP) Comments on the Draft Seismic Source Characterization (SSC) Report and Technical Integrator (Tl) Team Responses Senior Seismic Hazard Analysis Committee (SSHAC) Level 3 SSC Palo Verde Nuclear Generating Station (PVNGS) This attachment contains technical comments made by the PPRP on various drafts of the PVNGS SSC Report, and provides a record of the Tl Team response to each comment. PPRP comments are listed by date received and draft report location (section number and page number). Please note that as text was added and deleted during the revision process, draft report locations of PPRP comments (primarily page numbers) are not necessarily the same as their locations in the final report. April 17, 2015 PVNGS SSC Additional Documentation Attachment 3, Page 1of53 Date Location in No. Received Report1 1 1/13/2015 Section 1. 1 , Page 1-2 2 1/13/2015 Section 1.1.3. Page 1-3 3 1/13/2015 Section 1.2, Page 1-4 4 1/13/2015 Section 1.3, Page 1-4 5 1/13/2015 Section 1.3, Page 1-5 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT PPRP COMMENTS AND Tl TEAM RESPONSES Location of PPRP Comment Comment Revision Chapter 1 Please clarify the new data, methods, and Throughout models since the 1993 study to complement report the 2013 UCERF3 example. It appears that the product of this SSC study will be a replacement for the current SSC model; if it is, please so state. The roles of McGuire and Walling need to be (Same) described. These two sentences effectively define the (Same) common terminology of being "hazard informed"; if desired, this terminology could be defined here because it is used later in the report text (e.g., Section 3.2.9) as a reminder of the usefulness of the hazard sensitivity analyses. Comment A: The logic for the order of the (Same) numbered work products is not clear. Please consider an order that reflects the logical sequence of the work, such as Project Plan, Workshop Summaries, Earthquake Catalog. SSC Model, Hazard Input Document, Reference Evaluation Table, and Database; or use the Table of Contents and Appendix order. Comment B: Please explain which products are not provided in this report and why. Has the PPRP reviewed these Workshop (Same) Summaries in any form yet? Will the PPRP letters on the Workshops be included in the 1 PPRP comment locations refer to draft versions of the SSHAC report. April 17, 2015 PVNGS SSC Additional Documentation Summary of Revisions to Report Text revised as suggested. See also comment #6 and comment #7 for further discussion of this issue. In regard to "replacement" vs. "update", yes, this should be described as an updated SSC model. Report text revised throughout. Text revised to add description of the roles of McGuire and Walling. Text added to summarize the approach as being "hazard informed" and to define that term as it is used throughout report. The ordering of these items is revised as suggested. Report text revised. PPRP correspondence appendix (originally Appendix B) will not be included in the final report, consistent with the Attachment 3, Page 2 of 53 Date Location in No. Received Report1 6 2/17/2015 Section 1. 1 , Page 1-2 7 2/17/2015 Section 1 . 1 , Page 1-2 8 1/13/2015 Section 2.2, Page 2.2 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision summaries? Will the Workshop Summaries be more like a summary of the topics covered, names of the presenters, and copies of presentations? We are concerned about a technical document being prepared that does not have PPRP review. Upon rereading this sentence and the non-(Same) response to Michael's previous comment, the "level" of update is not clearly described. The "new data, methods, and models" are not described, and are not evaluated with respect to the hazard significance. Instead, this discussion should focus on the level of update required by the NRC. What is the date of the current licensing basis? The update should(?) probably be from that date to the present. regardless of the 1993 and 2012 SSC studies. This matter should be clearly discussed. Following up on Michael's comment, the reader (Same) would have a better sense of what areas of data, methods, and models are going to be incorporated in the SSC study if there was a short discussion of key new data and models that will be incorporated in this SSC study. Chapter 2 Is this discussion needed, as level 3 is NIA proscribed for this project? The existence of other levels is irrelevant to the PV project. The discussion of the SSHAC methodology should focus on Level 3, which was specified by the PVNGS SSC Additional Documentation Summary of Revisions to Report Diablo and Hanford reports. The PPRP closure letter will be included as part of the preface material. Workshop Summaries appendix includes only workshop presentations and agendas, which have been reviewed by the PPRP. This appendix does not includes "workshop summaries" per se. Revisions were made to the paragraph to provide an example of new data, model, and method. Very brief descriptions are provided, with details presented in subsequent chapters. Palo Verde's operating license was extended in 2011 for an additional 20 yrs, allowing for operations through 2047. Little new seismic information was provided as part of the extension process, which relied heavily on data developed during the original licensing process. As described in Sect 1.1.1. the current work is required as part of post-Fukushima directives from NRC. which specify the need for SSHAC3 for the current screening of WUS plants. Paragraph revised to provide example of new data, model. and method available since REI (1993). Discussion is minimal. as details are presented in subsequent chapters. This very brief discussion is intended to provide context for the selection of SSHAC levels. No change to text. Attachment 3, Page 3 of 53 Date Location in No. Received Report1 9 1/13/2015 Section 2.3.9, Page 2-7 10 1/13/2015 Section 2.4, Page 2-7 and 2-8 11 2/17/2015 Section 2.3.3, Page 2-4 12 2/17/2015 Section 2.3.3. Page 2-5 13 2/17/2015 Section 2.4, Page 2-7 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision NRC as noted in Section 2.0. This report should not be a SSHAC training document, but should explain how the SSHAC process has been carried out for this project, and at the SSHAC3 level. Should the "database" be described as a (Same) geographic or geospatial database containing geographic or spatial information? Regarding released versus published: Reports (Same) such as the LCI ones are gray literature and best termed released (i.e. made available), not published in the normal sense of a peer-reviewed professional journal article or state-federal publication. The nature of independent technical review of the released reports and maps should be stated. This sentence represents the second part of (Same) the two-step SSHAC process. As such it should be in a paragraph by itself. Could you add more explanation of the integration process to make the new paragraph more parallel with the discussion of evaluation? Please explain this role more clearly so there (Same) isn't a one-paragraph sentence. and remind the reader of the working time between Workshops when the Hazard Analysts input was obtained and used. Is this considered to be an independent {Same) technical review? In general. what was the independent peer review process for the new data collection? This was asked for in a previous PPRP comment. PVNGS SSC Additional Documentation Summary of Revisions to Report Text revised to refer to "spatial database." Text revised as suggested. More detail added to discussion of integration process. Additional sentence added. No, the PPRP's review of the Site Area and Site Vicinity maps should not be considered an independent technical review. No truly independent (3'd party) review of these maps occurred. Consistent with the SSHAC process, the Tl Team and PPRP communicated frequently about the plan for data collection, as well as the Attachment 3, Page 4 of 53 Date Location in No. Received Report1 14 1/13/2015 Section 3. 1 , Page 3-1 15 1/13/2015 Section 3.1.1, Page 3-1 16 1/13/2015 Section 3. 1 . 1, Page 3-2 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision Chapter 3 It would be appropriate to state that the PPRP Section reviewed the Project Plan; here are the details 3.2.1, Page for your consideration: The PPRP was 3-3, 151 provided with a copy of the Project Plan dated paragraph January 17, 2013, in advance of the Kickoff Meeting (Workshop 0) that was held on January 21, 2013. Although there was no discussion of PPRP comments during the Kickoff Meeting, the PPRP provided detailed written comments on the January 17, 2013 version of the Project Plan on January 21, 2013. We received a revised version of the Project Plan on February 19, 2013, and felt that our comments were satisfactorily addressed and that the Plan was made clearer and thus was more effective for its intended use. We suggest that this review process be mentioned in Section 3.1. The "collection of new data as needed" should (Same) be described as an evaluation process that involves identifying how possible new data could impact the overall evaluation; i.e., the "need should be clearly driven by the evaluation process in terms of possible impact on the SSC model. "Logic Tree" is an important element in the (Same) SSC model and should be described in a sentence, in a reference to somewhere else in the report, and augmented by a clear glossary entry. Please consistently refer to this element PVNGS SSC Additional Documentation Summary of Revisions to Report final results. Text changed from "reviewed by" to "presented to" the PPRP. Details of PPRP review and revision of Project Plan added. Text revised as suggested. Definition for logic tree provided. The phrase "logic tree model" has been removed from the report text. Attachment 3, Page 5 of 53 Date Location in No. Received Report1 17 1/13/2015 Section 3.2.2, Page 3-3 18 1/13/2015 Section 3.2.8, Page 3-6 19 1/13/2015 Section 3.2.8. Page 3-8; Figure 3-1 20 2/17/2015 Section 3. 1 . 1, Page 3-1 21 2/17/2015 Section 3.1.2. Page 3-2 22 2/17/2015 Section 3.1.1, Page 3-1 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision either as a "logic tree" or a "logic tree model", but not both. The scope of the REs {and PEs) was much Section broader than significant parameters and 3.1.1, Page features and should include issues of new 3-1, Item 4 data, new models, and proponent views. It seems that the PPRP has not seen this Chapter 3 summary; procedurally, we should review it and provide written comments similar to what we did for the previous workshops. This figure is not cited in the report. Is this Figure 3-1 NU REG figure needed? It does not specifically represent the SSHAC Level 3 process, nor does it include Workshop 0 and the Final Briefing that were part of the PV project. If you want a figure, it should accurately represent the PV Project. This would read more clearly if written: "The {Same) PPRP was involved in the evaluation process through attendance at workshops, review of project interim documentation. and attendance at selected working meetings." This sentence would read more clearly written Section as:" ... integration process through attendance 3.1.3 at workshops, review of interim project documentation, and attendance at selected working meetings." This sentence is also redundant with that on the preceding page. and in the next section -please consider consolidation. Seems like logic tree should be introduced first, {Same) then sensitivity analysis of the tree follows. PVNGS SSC Additional Documentation Summary of Revisions to Report Text revised as suggested. Text revised throughout Chapter 3 to indicate that the workshop "summaries" received by the PPRP included workshop agendas and presentations, as opposed to formal notes or minutes. Figure 3-1 is cited twice on the first page of Chapter 3. This figure represents the elements of the SSHAC process, and is not PVNGS-specific. Text revised as suggested. Agree. Section 3.1.3 simplified to reduce redundancy. We removed discussion of logic tree from this section. Really logic trees are built and revised after evaluating data. Evaluation phase now Attachment 3, Page 6 of 53 Date Location in No. Received Report1 23 2/17/2015 Section 3.2.10, Page 3-7 24 1/13/2015 Section 4.1, Page 4-1 25 1/13/2015 Section 4.1.1, Page 4-1 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision The previous response about the PPRP's {Same) review of workshop summaries is not satisfactory. The term "summary" is not equivalent to "Workshop agenda and copies of presentations." Please make this change for the sake of clarity. Chapter4 The orogenies resulted from subduction of {Same) buoyant crust, resulting in the flattening of the subducting slab and back-arc shortening. In turn, this shut off Sierran volcanism. with eastward migration and then cessation of subduction-related volcanism. The subduction was occurring well before these orogenic phases occurred. Please consider clarifying and correcting this aspect. Regarding the term "thin-skinned," this has {Same) always been a poor term, as it implied no involvement of basement rock in its original usage. All "thin-skinned structures must root into basement, as one cannot shorten the sedimentary cover without shortening the rock beneath. Others use it simply refer to the style of crustal shortening -ramp and flat crumpling in thick sedimentary settings, as opposed to Laramide or Pampean style, basement-cored uplifts that occur where sedimentary cover is thin or already consumed by "thin-skinned" shortening. If you use this term, please define and describe exactly what you mean, as this is PVNGS SSC Additional Documentation Summary of Revisions to Report described as evaluating data. and evaluation of hazard significance of various aspects of the base case model. Text revised to clarify agenda and workshop slides were provided as opposed to a workshop summary. Text added clarifying that orogenesis occurred subsequent to subduction. Sentence deleted, paragraph rewritten to simply describe the fact that thrusts are low-angle structures. Attachment 3, Page 7 of 53 Date Location in No. Received Report1 26 1/13/2015 Section 4.1.1. Page 4-1 27 1/13/2015 Section 4.1.1, Page 4-1 28 1/13/2015 Section 4.1.2, Page 4-2 29 1/13/2015 Section 4.1.2, Page 4-2 30 1/13/2015 Section 4.1.2. Page 4-2 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision a controversial term to some researchers. Attributed to. or a consequence of? Flattening (Same) is a result of subduction of buoyant crust. Arc volcanism is generated at subduction depths of +110 km. As the slab flattens, arc volcanism ceases. or in this case, migrated east to where the subducting slab reached the necessary depth for melting. Please consider adding this discussion. Baja California and Sonora Mexico are not Figure 4-1 shown on the first map, Figure 4.1, which should be extended southward to at least include all the site region. The northern Basin and Range (tectonic {Same) province) should be indicated on Figure 4.1 or Figure 4-1 some other suitable map. There should be a clear definition of Basin and Range as a tectonic province, vis-a-vis the Great Basin as a physiographic region. The Wasatch is not the western margin of the (Same) Great Basin, nor is the central Nevada seismic belt the eastern margin. The western margin is the Sierra Nevada frontal fault zone, whereas the eastern margin is the Wasatch frontal fault zone. Please correct. Please check the accuracy of your statement that the margins accommodate more than half of the extension, once the margins are corrected. This statement doesn't follow with your earlier NIA statement that more than half of the extension PVNGS SSC Additional Documentation Summary of Revisions to Report Connection between trends in magmatism and migrating contact between subducting slab and asthenosphere added. Figure 4-1 has been revised to address this. Text has been revised so that geodetic and geologic transects refer to specific locations within the northern Basin and Range. All subsequent references to the Great Basin are also removed. Figure 4-1 revised to show boundaries of the northern and southern Basin and Ranoe. Specific reference points for these measurements added. More than half of 3 mm/yr (so more than 1.5 mm/yr) is found to be localized to the margins of Attachment 3, Page 8 of 53 Date Location in No. Received Report1 31 1/13/2015 Section 4.1.2, Page 4-2 32 1/13/2015 Section 4.1.3, Page 4-3 33 1/13/2015 Section 4.2, Page 4-3 34 1/13/2015 Section 4.2.1, Page 4-3 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision is accommodated on the margins. Please explain. Please identify what areas are covered by the (Same) Sonoran Desert and how they relate to the southern Great Basin. Most researchers now believe the "proto-Gulf' (Same) was simply earlier southern San Andreas fault transtension. The southern SAF was close to its modern configuration, albeit at a slower rate, by 12 Ma. The San Gabriel fault was active during this phase, resulting in Ridge Basin. So was the Naciemento (and possibly Rinconada) and many other faults of the early SAF system. The Gulf opened prior to 5 Ma -there is much literature on this topic that post-dates Lonsdale, 1989. Should "north" at the end of the sentence be {Same) northwest? Or are you referring to the absolute plate motion. in which case you are referring to relative motion between the Pacific and North American plates. Please clarifv this statement. Are the discontinuous northwest-to northeast-{Same) trending mountain ranges consistent with the Section earlier statement about structural trends being 4.1.2, Page NNE to ENE? 4-2, 4th paragraph PVNGS SSC Additional Documentation Summary of Revisions to Report the region, according to geodetic data. Therefore, less than 1.5 mm/yr is available for the interior of the region. Koehler and Wesnousky find that the long-term extension rate across all faults in the interior of this region is approximately 1 mm/yr, matching the geodetic constraint for the interior. No chanQe to text. In this sentence, Sonoran Desert was simply used as a way to describe southeastern Arizona, or the general location of the PVNGS site. To avoid confusion, text has been edited to indicate that southeastern Arizona hosts less than half of the strain calculated along this transect. Lonsdale cited in regard to the linked system of basins and transforms. Timing of Gulf opening comes from Oskin et al. (2001) and Oskin and Stock (2003), which have been added (text has also been revised to indicate localization at 6 Ma rather than 5 Ma). Also, text has been revised to clarify that we are referring to opening of the northern Gulf of California. Corrected sentence to read "northwest", since we are describing the relative plate motion vector. Earlier statements described NW-striking detachment faulting occurring from 30-15 Ma, as well as (now clarified) N-to ENE-striking block faulting occurring from 15 Ma. So, section 4.2.1, Page 4-3, 2nd paragraph should be Attachment 3, Page 9 of 53 Date Location in No. Received Report1 35 1/13/2015 Section 4.2.1, Page 4-3 36 1/13/2015 Section 4.2.1, Paqe 4-4 37 1/13/2015 Section 4.2.1, Page 4-4 38 1/13/2015 Section 4.2.3, Paqe 4-6 39 1/13/2015 Section 4.2.5, Page 4-7 40 1/13/2015 Section 4.2.5, Page 4-7 41 1/13/2015 Section 4.2.5. Page 4-7 42 1/13/2015 Section 4.2.5, April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision How can extension be more complete? Is it {Same) ever complete? Do you mean a greater magnitude of extension? Does more complete imply that extension is done? Please clarify. Please give quantitative examples of what you {Same) consider to be slow and lonq. The kinematics of the Sand Tank fault are {Same) assumed, as there are no direct kinematic data. Perhaps it is better to state that the Sand Tank fault is assumed to be a normal fault. Is this the same as saying that the known faults {Same) do not exhibit seismicitv? Please elaborate. Is there not continued development of the {Same) Salton Trough in the modern tectonic environment? Please clarify. Please revise as follows. At the workshop, {Same) Rockwell argued for a higher rate based on new paleoseismic data that demonstrated more frequent earthquakes via a longer record. The Thomas and Rockwell record is too short, encompassing only 2 events (one cycle). Is this still part of the Colorado Desert {Same) Province? Please clarify. Is this true? Or are earthquake locations poor? {Same) PVNGS SSC Additional Documentation Summary of Revisions to Report describing this range of azimuths. Corrected to now describe NW-to ENE-trending mountain ranaes. Yes, poor phrasing. Text has been edited to more clearly state that the SBR physiographic reflects extension that has largely ceased. whereas NBR physiography reflects ongoing extension. Included specific numbers from the referenced paper (Pearthree et al., 1983 added). Text revised as suggested. Text revised to clarify that seismicity is diffuse and does not form aliqnments. Replaced "formed" with "initiated. Text deleted. Clarified. The title of this subsection has been edited to simply ready "Colorado Desert Province". and the introduction states that this province extends into the northern Gulf of California. When discussing characteristics of the northern gulf. the text now make it clear that this is one portion of the greater physiographic province. Text revised here and in earlier instances in 4.2.5 Attachment 3, Page 10 of 53 Date Location in No. Received Report1 Page 4-8 43 1/13/2015 Section 4.2.6, Page 4-8 44 1/13/2015 Section 4.2.6, Page 4-8 45 1/13/2015 Section 4.2.6, Page 4-8 46 1/13/2015 Section 4.2.6, Page 4-8 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision Most seismicity should be associated with transform structures and spreading ridges. The rocks were produced in the Mesozoic, but (Same) the Peninsular Ranges themselves are young and a result of rift-shoulder uplift. See Mueller et al., 2009. There is no evidence of topographic relief prior to the middle Miocene, and most uplift may be Pliocene and younger. Should the San Jacinto Mountains be the (Same) Santa Rosa Mountains? Fialko argues for close to 20 mm/yr, but that (Same) includes strain from the Elsinore fault as well. Hudnut and Sieh (1989) suggest 3-6 mm/yr for the Superstition Hills fault. Gurrola and Rockwell (1996) suggest 5-9 mm/yr for the Superstition Mtn fault. Together, a rate of 8-15 mm/yr is consistent with Blisniuk's rate at Anza. as well as Fialko's rate (which includes both Elsinore slip and the deformation associated with NE-striking cross faults. Please fix this. The 1-2 mm/yr slip rate is for the southernmost NIA end of the fault in the Coyote Mtns. The rate increases in the Coyote Mtns to 2 mm/yr only 2-3 km NW from the Fletcher et al. locality (Masana et al., 2012, 2013). The rest of the PVNGS SSC Additional Documentation Summary of Revisions to Report to specify that patterns of faulting and seismicity are less well defined in the northern Gulf of California. For this specific portion of the Colorado Desert Province (the Gulf, north of Isla Angel de la Guarda), Persaud et al. (2003) argue that deformation is distributed across many faults related to the Delfin basin, Consag basin, and Wagner basin. They argue that there is no primary structure defining this portion of the Gulf, and that is reflected in the seismicitv. Yes, timing of the uplift was conflated with age of magmatism. Corrected timing, citing Mueller et al. (2009). Yes, changed to Santa Rosa Mountains. Yes, clear mistake. The intent was to describe the UCERF3 best estimates along the entire fault system, which would be Blisniuk et al. (2013) from the Clark/Coyote Creek overlap to the north, and the sum of the UCERF3 best estimate slip rates for Superstition Mtn and Superstition Hills to the south. These latter slip rates are 7 mm/yr and 4 mm/yr (respectively), summing to 11 mm/yr. The goal of this paragraph is simply to provide a brief, simplified picture of one of the major faults within the Peninsular Ranges province. No change to text. Attachment 3, Page 11 of 53 Date Location in No. Received Report1 47 1/13/2015 Section 4.2.6, Page 4-8 48 1/13/2015 Section 4.2.6, Page 4-8 49 1/13/2015 Figure 4-1 50 1/13/2015 Figure 4-8 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision Elsinore slip rate is transferred to the Earthquake Valley fault via the Palomar Mountain stepover, and then to the southern San Jacinto fault via the Vallecito-Fish Creek Mountain stepover (Rockwell et al., 2013) at a rate of 2.5 mm/yr. Magistrale and Rockwell (1996) referred to this as the eastern strand of the Elsinore fault. Please consider that Fialko (2006) drew his (Same) interpretation because at least half of the Elsinore slip rate had been added to the southern San Jacinto fault rate at the latitude of Fialko's study. The 1910 earthquake produced 25 cm of RL (Same) slip on a circa 1890's concrete flume -see Rockwell et al., 2014 in press. Also, the Laguna Salada and Borrego faults are SE continuations of the Elsinore fault zone and produced the 1892 M7.2 Laguna Salada earthquake and the 2010 M7.3 El Mayor earthquake. Please revise this statement. The map should be extended to the south to (Same) include the entire 400-km-radius study region. The star should be labeled as the PVNGS site. The second paragraph of Section 4.1.1 refers to Baja California and Sonora, Mexico; these locations should be labeled in the expanded area of Fiqure 4-2. Please indicate the magnitude range of the (Same) Lockridge et al. data shown. Why state that the ANSS seismicity shown includes statistically dependent and independent events? If all of the ANSS data within the date and magnitude limits are included, there is no need to point out PVNGS SSC Additional Documentation Summary of Revisions to Report This part of the sentence has been deleted. Text revised to incorporate these points. New figure created to address these issues. Figure revised as suggested. Also, all Lockridge data moved to new figure to improve the clarity of ANSS versus Lockridge data. Attachment 3, Page 12 of 53 Date Location in No. Received Report1 51 2/17/2015 Section 4.1.1, Page 4-1 52 2/17/2015 Section 4.1.3, Page 4-3 53 2/17/2015 Section 4.2.1, Page 4-4 54 2/17/2015 Section 4.2.2. Page 4-5 55 2/17/2015 Section 4.2.4. page 4-7 56 2/17/2015 Section 4.2.4. Page 4-7 57 2/17/2015 Section 4.2.5, Page 4-7 58 2/17/2015 Section 4.2.6, April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision that the catalog includes both statistical types of events. The symbol for the Lockridge clusters is not clear on the map vs. what is in the figure legend. Perhaps a small circle around each cluster could be used as the svmbol. " ... migrated from west to east, tracking the (Same) westward migration ... " If it migrates from west to east, then the tracking should also be west to east, not westward. Is this what you meant?? 25 Ma? Doesn't Atwater say 28 Ma? NIA Isn't the Sand Tank fault to the SE of the site? (Same) "the ISB has produced 3 historical scarp-(Same) forming earthquakes ... " Fig 4-9 shows only 2. Please clarify. " ... and three significant earthquakes ... " But (Same) you list 4 earthquakes(?) Please clarify. Is the Parkfield section really accommodating (Same) 30-mm/yr of creep? Or is that the section NW of Parkfield? If the fault initiated at a specific time, then it {Same) wasn't "Miocene to Pliocene". Was it one or the other? If unclear, specify, "initiated sometime in the Miocene or Pliocene". This seems to refer to only the major faults in {Same) PVNGS SSC Additional Documentation Summary of Revisions to Report Text fixed as suggested. Regarding the initiation of the modern transform plate boundary in California, Atwater (1970) says 28 Ma. As discussed by Stock and Hodges (1989), Atwater (1989) revised this number to 25 Ma. Atwater (1970) is still cited, however, to credit the origination of the plate tectonic reconstruction. No change to text. Text fixed as suggested. The Hebgen Lake earthquake is north of the view extent of the figure. All three earthquakes are now specified in the text. Text referring to seismicity along the creeping section of the San Andreas fault revised list four sianificant earthauakes. Creep is occurring northwest of Parkfield, text fixed as suggested. Text revised to specify late Miocene. Sentence added to name additional faults. Attachment 3, Page 13 of 53 Date Location in No. Received Report1 Page 4-8 59 2/17/2015 Section 4.2.6, Page 4-8 60 2/17/2015 Section 4.2.6, Page 4-8 61 2/17/2015 Section 4.2.6, Page 4-9 62 2/17/2015 Section 4.2.7, Par.ie 4-9 63 2/17/2015 Figure 4-13 64 2/17/2015 Section 4.1, Page 4-1 65 2/17/2015 Section 4.2.3, Page 4-6 66 2/17/2015 Section 4.2.7, Page 4-9 67 2/17/2015 Section 4.3, April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision the peninsular ranges north of the border. To the south, there is also the Agua Blanca, San Miquel, etc. Please clarifv. Superstition Hills earthquake was in 1987 (not (Same) 1986}. 15 large earthquakes? Yes, these would be the (Same) M7.2-7.3 events. However, the "small" events may have been at least as large as the 1918 earthquake -M6.9. Consequently, most would call all 21 events "larqe" Needs citations Mueller and Rockwell, 1995, (Same) Hough and Elliot, 200 , Fletcher et al., 2014} Hough 1994??? Didn't Rymer do the work on (Same) the surface ruptures for these faults?? For historical surface ruptures, this figure (Same) should include the 1910 Glen Ivy earthquake, the 1979 Homestead Valley earthquake, and the November 22, 1800 San Jacinto earthquake. Also, the Christmas Day, 1899 earthquake at Hemet produced some surface rupture. Recent is often used in exchange for (Same) Holocene, but what you really mean here is late Miocene to present Is it a segment or a whole fault on its own? (Same) There are better and more direct citations for (Same) these surface ruptures. Mike Rymer mapped them. References needed here. (Same) PVNGS SSC Additional Documentation Summary of Revisions to Report Text fixed as suggested. Text revised to state "21 moderate to large prehistoric earthquakes" have been interpreted along the northern and central San Jacinto fault in the past 4,000 years. Citations added. Yes, Rymer reference added. 1899 rupture already on figure. Remaining 3 ruptures added. Text revised as suggested. Text changed to "section". This is based on the USGS discussion of various sections of the Hurricane fault, which are defined based differences in structure. expression, and rupture history. This section would not be considered a distinct fault. Rymer (1992) citation added. Added Kreemer Workshop 2 reference, deleted Attachment 3, Page 14 of 53 Date Location in No. Received Report1 Pages 4-9 and 4-10 68 2/18/2015 Figure 4-6 69 2/17/2015 Figure 4-8 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision Figure 4-6 uses an inappropriate catalog for Figure 4-6 comparing the spatial distribution of seismicity Figure 4-8 with the distribution of faults. Please use the Figure 4-9 non-independent compiled catalog including Section events down to MO (described in the next 4.2.1, paragraph). Some categorization of Pages 4-4 earthquakes by size should be used so the and 4-5 smallest events neither get lost nor dominate the figure. There needs to be a discussion in the text regarding the relationship between the patterns of seismicity and the locations of Quaternary faults. It would be necessary for this and the subsequent figures to compile existing earthquake focal mechanisms to illustrate for the reader the current tectonic styles within the site region Figure 4-8a needs to be updated using the Section non-independent compiled project catalog that 4.2.1. includes all seismicity in the in the model Pages 4-4 region (i.e .. the independent catalog with all the and 4-5 excluded events included and magnitudes down to near 0). This figure could be discussed with respect to possible associations with tectonic provinces. The relationship between felt and instrumental seismicity with respect to mapped faults will need to be assessed using a figure that includes both faults and seismicity. Figure 4-8a currently uses two possibly overlapping catalogs (the ANSS catalog and the NASB catalog); the project independent plus non-independent earthquakes down to MO should be used for making this figure and PVNGS SSC Additional Documentation Summary of Revisions to Report comparison to northern Basin and Range. Figure 4-6, earthquakes removed. This figure only ever cited now in reference to the distribution of Quaternary faults in the Site Region. There is no discussion of the association of seismicity with mapped Quaternary faults, since we model all faults from QFDB as active sources. However, we have added or revised several figures to the sequence in Figure 4-8 that allow the detection of UNMAPPED faults based on patterns of seismicity. These new figures are accompanied by new text in Section 4.2.1. New focal mechanism figure also added and is part of this discussion. The project catalog does not include any events that are smaller than M2.7, since it was constructed for PSHA calculations. Instead. in response to this comment. we have used "off the shelf' catalogs from ANSS and AZGS that go down to MO. Associated discussion is added to Section 4.2.1. Attachment 3, Page 15 of 53 Date Location in No. Received Report1 70 2/17/2015 Figure 4-8 71 1/13/2015 Section 5.1.3, Page 5-2 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision discussing what it shows. There is no special benefit to using the ANSS catalog. as it is likely to be less comolete than the compiled cataloq Figure 4-8b uses two other catalogs for a Section comparison of seismicity with tectonic 4.2.1. provinces. The non-independent compiled Pages 4-4 project catalog should be used again. If and 4-5 Quaternary faults were added to this figure. it would be a zoom-in of Figure 4-6. An additional figure is likely needed to zoom in on the region within about 60-100 km of the site, thus including the Sand Tank fault and the region containing the new geologic mapping. The seismicity within this region is known to be sparse. Efforts should be made to obtain focal mechanisms from the better-recorded (and thus the larger) earthquakes within this region. These mechanisms should be compared with available geodetic data to evaluate the degree of consistency Chapter 5 Does the first sentence actually mean that the (Same) number of areal sources considered by the five teams ranged from 10 to 17? Similarly, the second sentence could be recast to say that four of the teams used between 4 and 23 fault sources, with the fifth group defining 94 fault sources. Why is this important enough to discuss here? Do you want the readers to compare these numbers with the number of aerial and fault sources used in the present study or to show how variable a result different teams can generate? Please revise this PVNGS SSC Additional Documentation Summary of Revisions to Report See above. No focal mechanisms are available for southern Arizona. Text revised to clarify the range in number of fault and areal sources defined by the five teams. This information is provided for context and to indicate the relatively small number of fault sources in these earlier SSC models. Attachment 3, Page 16 of 53 Date Location in No. Received Report1 72 1/13/2015 Section 5.3, Page 5-3 73 2/17/2015 Section 5.1.4, Paoe 5-3 74 2/17/2015 Section 5.3, Page 5-4 75 1/13/2015 Section 6.0, Page 6-1 76 1/13/2015 Section 6.1, Page 6-1 77 1/13/2015 Section 6.1, Page 6-1 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision paragraph to clarify why this information is important to the SSHAC process. The term "reference evaluation" is not {Same) explained. Please clarify to what extent there is an evaluation of the references and describe how this evaluation was used in the SSHAC process. Note about anchoring here? {Same) This section is not clear. {Same) Chapter6 You might want to consider some alternatives {Same) to the current title. During the development of the earthquake catalog, the term "Composite Earthquake Catalog" has been used. which is more descriptive of the catalog than "Project Earthquake Catalog". The catalog could also be called "Declustered Earthquake Catalog" or "PSHA Catalog" to focus on its use in PSHA calculations. In consideration of Comment C below, there may be a need for having a "Complete Earthquake Catalog" that contains all the seismicity in the region of interest for use in accessing seismicity associated with geological structures. This paragraph is written in a highly formal and {Same) stilted style, more suited to a legal brief than a scientific report. Please rewrite in a style consistent with the rest of the report. In this paragraph and several earlier {Same) paragraphs, the term "significant earthquakes" is used without clear definition. Based on the PVNGS SSC Additional Documentation Summary of Revisions to Report Text revised to define "reference evaluation" and to provide enumerated list of why and how this is used in the SSHAC process. Text added to address how the Tl Team avoided beino anchored to the base case model. Text revised to improve clarity. CATALOG OF INDEPENDENT EARTHQUAKES FOR PSHA, thus making it clear that this is a catalog of independent events intended to be used for Probabilistic Seismic Hazard Analysis. The paragraph has been re-written. Significant earthquakes are defined as magnitude 2. 7 or higher in the eastern portion of the study region and >4.7 is in the west. This Attachment 3, Page 17 of 53 Date Location in No. Received Report1 78 1/13/2015 Section 6.1, Page 6-1 79 1/13/2015 Section 6.1, Page 6-1 80 1/13/2015 Section 6.2 81 1/13/2015 Section 6.2, Pages 6-2 to 6-3 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision catalog selection criteria. the significant events appear to be those of M2. 7 or larger in the study region (4. 7 in the higher activity part of the study region as shown in Figure 1 }. Please clarify the meaning of "significant earthquakes" with a comprehensive definition including scientific and enqineerinq aspects. The composite catalog that is prepared using N/A the six-step procedure outlined in the fourth paragraph of this section does result in a catalog that is composed of statistically independent earthquakes. What about in the cases where '"aftershocks" are part of a sequence of large earthquakes, where rupture continued or extended along a fault zone {cf. Darfield sequence). There are also cases of a large regional earthquake triggering moderate to large earthquakes on independent faults-how are these cases addressed? The term "study region" was tentatively defined {Same) with an equivalent term "model region," with "study region" used more than "model region." Please explain in more detail why this region was defined, why its radius is 400 km, and provide references to other sections of the report where this term is used. The PPRP expects that Section 6.2 will be {Same) significantly revised and edited to address the PPRP comments on Section 6.2. This section is generally disjointed in terms of {Same) providing a systematic set of information that is needed for vetting the earthquake catalog data. PVNGS SSC Additional Documentation Summary of Revisions to Report explanation has been added to the text. In the Darfield sequence, the large M7.1 earthquake is considered the main shock (independent). The smaller, but still large, earthquakes that followed this event would be considered aftershocks (dependent), regardless of the amount of damage they caused. Moderate earthquakes on independent faults triggered by larger regional earthquakes are also assumed to be dependent. PSHA methodology requires a catalog of independent events. Note that large events specifically identified with a known fault were also removed from the catalog, in order to avoid double counting. No change to text. The 320 km radius comes from Reg. Guide 1.208 recommendations, and the text has been revised to state this. This revised text also presents language from Reg. Guide 1.208 that indicates why an SSC model might want to exceed this radius. The 400 km radius is now consistently called the "model region" throughout. Section 6.2 has been completely rewritten to discuss the features of each network, as obtained from network operators and catalog websites. Section 6.2 was completely rewritten to address this issue. Text revised to state that the final catalog spans Attachment 3, Page 18 of 53 Date Location in No. Received Report1 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision The data from various individual networks and several catalog compilations of data from an unidentified set of networks have been used in previous chapters. It would be important to discuss the features of each network as appropriate for the data to be used from the network. The basic monitoring framework is as follows: The relevant ANSS regional networks are in California, Nevada, and Utah. There is a small university-operated regional network in Northern Arizona. USGS operates the US National Network out of Colorado covering all states with a sparse network, and the Mexican network monitors the area south of the border. In parallel with the regional and national networks. there are organizations that compile reprocessed catalogs of earthquake locations and source characteristics using raw data from the above various sources. It should be carefully noted that this composite catalog is NOT likely suitable for assessing the presence of active faults. Because of the method used to create this catalog, all foreshocks and aftershocks have been removed; yet a catalog that includes all seismicity {and with duplicates removed) could be useful in comparisons with Quaternary fault maps in seeking evidence for fault activity based on clustered seismicity (including foreshocks and aftershocks) along a mapped fault trace or where no mapped faults have been found. Please address this issue as appropriate in this and other sections of the report. PVNGS SSC Additional Documentation Summary of Revisions to Report 160 years, ranging from 1852 -2012. Also, the title of this chapter has been revised to make it clear that this is a catalog of independent events and intended to be used for PSHA. The text now specifically states that the final catalog may not be suitable for assessing the presence of active faults. Attachment 3, Page 19 of 53 Date Location in No. Received Report1 82 1/13/2015 Section 6.8, Page 6-7 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision This section is important and depends on the {Same) definition of catalog completeness. Please clearly define what completeness means and how it is related to the activities of a seismic network operator (see suggestions for reworking Section 6.2). There is a tendency in this section to use sparse explanations and jargon; future readers would appreciate more clear explanations. The second sentence in the first paragraph is, "Unfortunately, several regional networks contributed to the PVNGS catalog and obtaining this type of information for each would be time-consuming." The message this sentence communicates is that nuclear power plant safety is not worth a time-consuming activity-the PPRP is certain that this attitude is not held by the Tl Team and is a misstatement. The lack of compiling data regarding the history and operation of the regional seismic networks surrounding and covering the PVNGS site vicinity and site study area was noted in our comment on Chapter 6.2. We strongly suggest that the basic spatial, instrumentation. and operational data be collected from the relevant network operators and be used to estimate modeled network completeness. We are reasonably confident that you will find that the network personnel have already done the "time-consuming" work that is needed These results can be compared with the composite catalog analyses that you have already carried out to reach a sound conclusion on catalog completeness as a PVNGS SSC Additional Documentation Summary of Revisions to Report The explanation of catalog completeness has been expanded. The second sentence in the first paragraph was poorly worded and could easily be misconstrued and was therefore removed. After the paragraph defining completeness times, the following line was modified to stress that applying statistical procedures such as the Stepp methodology is the preferred way to obtain completeness times. "Fortunately, a much better commonly used alternative approach is to use statistical procedures on the catalog itself." Variations of the Stepp methodology are frequently used to determine completeness times for PSHA. Completeness time data was requested from network operators but mostly inadequate information was received; primarily because many of the regional networks have only existed for a relatively short period of time. The statistical analysis of the catalog suggests that most completeness times for magnitude intervals of interest (above M4.0) extend back prior to the installation of many of the regional networks. In Arizona for instance, the record of >M4.0 events appear to be complete since 1920 but the first USGS instrument wasn't installed at Flagstaff until 1961 and NAU's three station network didn't start monitoring until 1986. The explanation of course is that when Lockridge et al. 2012, compiled the Arizona catalog he used data from other sources such as Dubois (1982) and newspaper accounts of felt reports in order to fill in the pre-instrumental record. In contrast, the Attachment 3, Page 20 of 53 Date Location in No. Received Report1 83 2/17/2015 Chapter6 84 2/17/2015 Section 6.1, April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision function of time. The title and subsequent terminology should Throughout be clearer. The objective is to have a catalog of Chapter 6 events that are statistically independent of each other, thereby not including foreshocks, aftershocks, or swarm-like occurrences. Since there also needs to be a complete seismicity catalog that includes the events excluded from the statistically independent catalog, it needs a meaningful name, such as "historical catalog" or "composite catalog". There are several additional names for the "independent" catalog in Chapter 6, such as "project catalog," "final catalog", "data catalog", "final PVNGS catalog," "comprehensive composite catalog", etc.-please pick two names for the two catalogs used in the SSC study, and don't use any others. It would be helpful to the reader to explain the characteristics of the two catalogs in this introduction, pointing out that the independent catalog is used for evaluating recurrence of future earthquakes for earthquakes magnitude 2.7 and larger, while the "more complete" catalog (name not established yet) contains all reported earthquakes in the region {needs to be specified) including earthquakes smaller than M2.7. In particular it is necessary to have a "complete" seismicity map within the 320-km-radius region around the PV site to support a discussion of the association of seismicity with QeoloQic structure and faults. Was there any explicit consideration of swarm-NIA PVNGS SSC Additional Documentation Summary of Revisions to Report network operator at AZGS maintains that M4.0 are complete since 2007 and M5.0 since 1970. As discussed in the Chapter 4 comments and responses, there is no version of the catalog that includes earthquakes below M2.7. In that case, our "complete" catalog prior to declustering cannot meaningfully be used to search for seismicity lineaments. The pre-declustering catalog also has no utility in terms of PSHA. It is therefore not presented. In chapter 4, ANSS and AZGS catalogs down to MO are used to search for spatial trends in microseismicity. The catalog is now consistently referred to as "the PVNGS catalog" Would have been removed in declustering Attachment 3, Page 21 of 53 Date Location in No. Received Report1 Page 6-2 85 2/17/2015 Section 6.2.1, Page 6.2 86 2/19/2015 Section 6.1, Page 6-1 87 2/19/2015 Section 6.2.1, Page 6-3 88 2/19/2015 Section 6.5, Page 6-8 89 1/19/2015 Section 7.0, Page 7-1 90 1/19/2015 Section 7.0, Page 7-1 91 1/19/2015 Section 7.0, Page 7-1 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision like occurrences, with no distinct main-shock? Or would they be identified by the foreshock-aftershock alqorithm? Please clarifv in the text. The role of the NAU needs to be discussed; is NIA the Northern Arizona Network now formally operated by AZGS personnel? Please clarify. Are quarry blasts confidently and systematically identified and excluded? Please clarify. "significant recorded earthquakes" -does this {Same) include historically reported earthquakes or only those that are instrumentally recorded? Please clarify. Under "Dates of Operation: were the early NIA Tucson seismograph records used? These date back to the first 2-3 decades of the century. Is "unk" a magnitude scale?? (also in Table 6-NIA 2). You mean that the magnitude scale that was used is unknown, but this is treated as a scale in and of itself. Is there a better way to indicate this? Chapter 7 Please remind the reader that Chapter 4 has {Same) substantial background information relevant to this chapter's focus on the Basin and Range province. Is this the same as saying "the general (Same) absence of tectonic landforms"?? What type of non-tectonic landforms are you referring to? Please clarify. The Lake Mead area is contiguous with (Same) northwestern Arizona--are these the same PVNGS SSC Additional Documentation Summary of Revisions to Report process, as described in Section 6.1 {only largest event retained). One of the focuses of Lockridge was swarm identification. No change to text. NAU is integrated into the Arizona network. AEIC is run out of NAU, but is part of AISN. No, NAU not operated by AZGS personnel. But shared data with AZGS. No change to text. "Significant recorded" includes both instrumental and historical earthquakes. Text to this effect has been added. We assume that the AZGS catalog delivered by Jeri Young (1852-2012) includes earthquakes recorded in the early 1900s from Tucson. No change to text. "Unk" means the original magnitude scale is unknown. As shown in Table 6-3, "unk" events are treated as equivalent to Mw (Petersen et al.. 2008). No change to text. Text revised as suggested. "Non-tectonic landforms" removed, we discuss the geomorphology of the landscape instead. Yes, "Lake Mead" has been removed from this sentence as suggested. Attachment 3, Page 22 of 53 Date Location in No. Received Report1 92 1/19/2015 Section 7.0, Page 7-1 93 1/19/2015 Section 7.0, Page 7-1 94 1/19/2015 Section 7.0, Page 7-1 95 1/19/2015 Section 7.0, Paqe 7-2 96 1/19/2015 Section 7.0, Page 7-2 97 1/19/2015 Section 7.0, Page 7-2 98 1/19/2015 Section 7.0, Paqe 7-2 99 1/19/2015 Section 7.0, April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision tectonic area? Isn't this a real discrepancy? Please explain {Same) your point. Could this be an issue of having an incorrect NIA Euler pole? At what rate? {Same) On any maps? Please specify/clarify. {Same) Certainly the late Quaternary. Can you {Same) preclude early Quaternary? Please clarify. There should be a discussion of seismicity in NIA the site region in parallel with the other four topics. What kinds of geologic rates? {Same) Why is seismicity missing from this discussion? NIA PVNGS SSC Additional Documentation Summary of Revisions to Report "Apparent" removed from the sentence describing comparatively low geologic extension rates and higher geodetic extension rates in Arizona. No change to text. Geodetic data are mentioned here to introduce the discrepancy in extension rates and not to offer potential explanations for whv. Cumulative geologic extension rate for the interior of the northern Basin and Range from Koehler and Wesnousky (2011) included for reference. Phrase "or shown on maps" deleted. Text revised to "Are large portions of the southern Basin and Range completely devoid of faults that have ruptured in the middle to late Quaternary?", which is the time range covered by later discussion. Discussion of seismicity in the site region is provided in Chapter 4. In response to comments in Chapter 4, those discussions will be expanded to describe the lack of spatial association between seismicity and mapped faults in Arizona. To clarify. Chapter 7 describes the issues that the Tl Team had to wrestle with before constructing the model. The paucity of seismicity in Arizona meant that seismicity was not something we could use to evaluate Quaternary faulting. No change to text. Text revised to specify "rates of extension". Discussion of seismicity in the site region is Attachment 3, Page 23 of 53 Date Location in No. Received Report1 Page 7-2 100 1/19/2015 Section 7.1.1, Page 7-3 101 1/19/2015 Section 7. 1 . 1, Page 7-3 102 1/19/2015 Section 7.1.1, Page 7-3 103 1/19/2015 Section 7.1.1. Page 7-3 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision What does this mean -please clarify. (Same) The background for this first mention of (Same) seismicity needs to be established earlier in this chapter. The total seismicity catalog needs to be used to look for associations with geological structure. The composite declustered catalog is not suitable for such comparisons as noted in our comments on Chapter Six. The presence or absence of seismicity? Please (Same) clarify. In the PPRP comments on Chapter 6. it was (Same) pointed out several times that the declustered catalog is an improper choice of catalog to search for spatial correlations between seismic activity and possible active-fault-related features. The declustered catalog is missing foreshocks and aftershocks and also is limited to earthquakes larger than M2.7--microearthquakes have been found useful for correlating with active faults--see for example the significance of the location of a small PVNGS SSC Additional Documentation Summary of Revisions to Report provided in Chapter 4. In response to comments in Chapter 4, those discussions will be expanded to describe the lack of spatial association between seismicity and mapped faults in Arizona. To clarify, Chapter 7 describes the issues that the Tl Team had to wrestle with before constructing the model. The paucity of seismicity in Arizona meant that seismicity was not something we could use to evaluate Quaternary faultinQ. No chanQe to text. Text clarified. Text revised to clarify that seismicity was not a determining factor in this analysis. Text revised to clearly state that the analysis of seismicity was not a determining factor in this analysis. Text revised to clarify that sparse seismicity was not a function of the declustered catalog, it is a characteristic of all earthquake catalogs covering the southern Basin and Range. Attachment 3, Page 24 of 53 Date Location in No. Received Report1 104 1/19/2015 Section 7.1.2, Page 7-4 105 1/19/2015 Section 7.2, Page 7-5 106 1/19/2015 Section 7 .2. 1, Page 7-5 107 1/19/2015 Section 7.2.1. Paqe 7-6 108 1/19/2015 Section 7.2.3. Page 7-8 109 1/19/2015 Section 7.2.3, April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision number of microearthquakes along the surface trace of the Shoreline fault offshore of Diablo Canyon. We recommend that a composite earthquake catalog be assembled to cover the 400km-radius study region. This catalog should include all seismicity reported by the cognizant seismic networks down to magnitude zero. The catalog must exclude non-natural seismic events including mining and construction explosions, sonic booms, and any other types of non-natural seismic events that are in the source catalogs. This complete natural seismicity catalog can be used to search for spatial and focal mechanism correlations between mapped geologic features and seismic activity in the Study Region. Such as gravitational collapse? What factors? {Same) Was Google Earth used for some of this?? (Same) Recall that the explanation on this quad had some errors and AGS promised to repair and reissue the map as v. 2 Please explain why this was done. {Same) This phrase may be from the dePolo and {Same) Anderson paper, but is seems misleading to have all the uncertainty on the greater side of the central value; what is likely meant is that there is an uncertainty of half an order-of -magnitude about the values of 0.001, 0.01, and 0.1. Using "or greater" is somewhat misleadino. Please clarifv. Certainly there is a range. Please specify. {Same) PVNGS SSC Additional Documentation Summary of Revisions to Report Sentence deleted. Yes, "Google Earth" added. AZGS has not yet published a revised version of this map. No change to text. Explanatory text describing why LCI conducted field investiqations added. Text has been revised to more explicitly reflect dePolo and Anderson's (2000) interpretations and conclusions. Text has been revised to more explicitly reflect Attachment 3, Page 25 of 53 Date Location in No. Received Report1 Page 7-8 110 1/19/2015 Section 7.2.3, Page 7-8 111 1/19/2015 Section 7.2.3, Page 7-8 112 111912015 Section 7.2.3.2, Page 7-10 113 111912015 Section 7 .2.3.2, Page 7-10 114 111912015 Section 7.2.3.2, Page 7-10 115 111912015 Section 7.2.3.3, Page 7-10 116 111912015 Section 7.2.3.3, Page 7-10 117 111912015 Section 7.2.3.3, Page 7-11 118 1/19/2015 Section 7.2.4, Paqe 7-13 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision Please provide a reference for this -seems too {Same) fast. Plus, are there not 100 ka scarps preserved in eastern Arizona? If you are citing the Machelle constraint of {Same) Hanks, its degradation of a 1 m high scarp in 100 kyr in desert climates of Southern New Mexico, which are comparable to your area. Read and cite the ref. Is this the same as evidence against? Please (Same) clarify. Please comment on the level of uncertainty. (Same) Could a half meter scarp be missed? 1 m? This is not a strong statement. One caveat is that strike-slip motion may not (Same) induce a vertical component and thus not be seen. Can you add that your saw into the deposits and didn't detect any faulting to them. This statement is not clear. What is meant by (Same) "this mapping project?" This chapter has several discussion of lineations; please clarify. Are their rate estimates points or bins? If bins, NIA revise prior citations of rates for dePolo and Anderson. Or it is an intrabasinal fault unrelated to any NIA now inactive fault at the front of bedrock. I don't buy it as an older Bull fault just because its way out there in the basin. How is this addressed in the SSC? {Same) PVNGS SSC Additional Documentation Summary of Revisions to Report dePolo and Anderson's (2000) interpretations and conclusions. 100 ka value comes from analysis described by dePolo and Anderson (2000). Text expanded and revised to mention the Machette constraint and Hanks et al. (1984). Text clarified to indicate "evidence for the absence of' activity. Text has been modified to provide qualitative caveat. We're highly certain that the Qi2 surface is not deformed, but less certain that this surface actually overlies the fault. Paragraph revised to clarify what could be and what could not be observed. Citation to LCI (2014) added to clarify "this mapping project". These slip rates are not bins. as described in revised text describing dePolo and Anderson slip rate categories in Section 7.2.3, Page 7-8. No change to text. We agree. Characterization of the Sand Tank fault in Chapter 10 gives low weight to the 0.001 slip rate that would follow from the interpretation that this is a Type 3 fault of Bull (2007}. No change to text. Section 7.2.4 rewritten to more clearly tie the results of this investiqation to the SSC model. Attachment 3, Page 26 of 53 Date Location in No. Received Report1 119 1/19/2015 Section 7.2.4, Page 7-13 120 1/19/2015 Section 7 .3, Page 7-13 121 1/19/2015 Section 7.3, Page 7-13 122 1/19/2015 Section 7 .3, Page 7-13 123 1/19/2015 Section 7.3, Page 7-13 124 1/19/2015 Section 7.3, Page 7-14 125 1/19/2015 Section 7.3.1. Page 7-14 126 1/19/2015 Section 7.4, Page 7-14 127 1/19/2015 Section 7.4, Page 7-14 128 1/19/2015 Section 7.4, April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision You might include here a statement that if {Same) there are potentially active fault sources within the site vicinity, their rates must be very low and covered by the aerial fault source model. Really. There are lots of slower faults there if {Same) vou look at the Quaternarv fault dataset. For how long? 100 ka? 1 Ma? {Same) You refer to this type of analysis earlier but provide no explanation. Perhaps move this discussion up? This was all stated earlier. Please combine and {Same) delete the redundancy Wasn't this stated earlier? {Same) In hind sight. it may be good to define what is {Same) meant here for the non-expert Most of the discussion in this and the following Figure 7-2 paragraphs refer to the Basin and Range and Figure 7-23 portions thereof. Please use consistent terminology and provide maps that show the locations of the Basin and Range elements. Here, central Nevada is said to have low rates, {Same) whereas in the preceding lines, the Central Nevada seismic belt is said to have relatively hiqh rates. Please clarifv. This will need to be justified. Do you assume (Same) PVNGS SSC Additional Documentation Summary of Revisions to Report Specifically, the first and last bullet points indicate what would have been added to the model if the Site Vicinity mapping had found local Quaternarv faults. Section 7.2.4 rewritten. We would like to avoid discussing the model as much as possible in Chapter 7. Since the point of the Site Vicinity mapping was to determine whether or not a local host source and local Quaternary faults could be defined, this section simply ties the mapping efforts to those two items. Sentence deleted. Text clarified to frame this in terms of interseismic period. No change to text. In these long reports, we are ok with allowing for redundancy. Oftentimes readers skip around to specific sections. Text revised to point reader back to 7.2.3 for more detail. Basics are retained here. Paragraph largely deleted. Definition added. Figures revised to include boundaries of the northern Basin and Range. Text now specifies eastern Nevada to avoid confusion between this part of Nevada versus the Central Nevada seismic belt. Justification added. Attachment 3, Page 27 of 53 Date Location in No. Received Report1 Page 7-15 129 1/19/2015 Section 7.4, Page 7-15 130 1/19/2015 Section 7.4, Page 7-16 131 111912015 Section 7.4, Page 7-16 132 111912015 Section 7.4, Page 7-16 133 111912015 Section 7.4, Page 7-17 134 1/19/2015 Section 7.4. 1, Page 7-18 135 1/19/2015 Table 7-4 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision this rate because all of the faults in this category are very poorly expressed, so based on their morphology, should have rates below this value? Please elucidate. Seems a bit shallow for the state on average NIA The point of this statement is not clear. What is N/A the issue for earthquake recurrence that is significant to PV? It might be also worth discussing that an M7 or (Same) M8 earthquake should rupture the surface and be locked into the geomorphology for tens of thousands of years. Over this timeframe, there should be a significant number of scarps, as are observed in the northern B&R. Thus. there is no evidence of the past occurrence of such events. supporting the low rates inferred from geology. You might mention the distance to the site. Has NIA a sensitivity analysis been conducted to see if this makes a difference? Dip slip? Won't you still see scarps? NIA Are you saying that there are likely numerous NIA unidentified faults in the southern B&R? In comparing tables 7-2, 7-3, and 7-4, different {Same) slip rates are used to calculate the number of PVNGS SSC Additional Documentation Summary of Revisions to Report We agree, but this is the crustal thickness value used by Corne Kreemer in his presentation. which the text is referencing. No change to text. This statement was added to close the interseismic window on events of this size, and show what a more conservative recurrence interval would look like when comparing the geodetic prediction of recurrence versus observed recurrence. No chanqe to text. Good suggestion, text added. No such sensitivity analysis has been performed. No change to text. If creep rates were high. we might see this in the landscape. At low creep rates, we probably wouldn't see them. No change to text. This list is discussing generic problems associated with geodetic rates, not necessarily issues specific to the PVNGS model region. No change to text. Table 7-3 has been revised to match the slip rates used in Table 7-2, and to include the Attachment 3, Page 28 of 53 Date Location in No. Received Report1 136 2117/2015 Chapter 7 137 2117/2015 Figure 7-20 138 2/19/2015 Section 7.2.3.1, Page 7-10 139 2/19/2015 Section 7.2.3.4, Page 7-13 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision expected faults required to satisfy the observed strain rate. It would be nice to have these all the same because it would be easier to then calculate expected versus observed for any given class. Assuming 0.1 mm/yr, 17 normal faults are required, but Table 7-2 skips from 0.05 to 0.2 mm/yr for the percentage of scarps preserved after 25 ka. At 0.05 mm/yr, scarps are preserved after 25 ka. The argument should be made that it would be hard to miss 33 faults if randomly generated in time (Poissonian). Extensive comments on the need for further NIA discussion of seismicity are found on Page 4-14 of the PPRP comments on Chapter 4. A substantial case has not been made that seismicity in the region does not provide information relevant to Quaternary faulting that may be significant to the site. Add Gila River lineament to caption? Sanford (Same) doesn't use the word lineament in the title of his paper. just fracture zone. May want to check this. or put lineament in parentheses with purple arrows. Same comment for fig. 7-21 The lack of deformation on the Palo Verde clay (Same) does not preclude 50-100 m of down-to-the-SW displacement on the inferred fault because they are of different ages. It just means that if such displacement exists, it predates the PV clav. In assessing the actual existence of this (Same) proposed structure, is there any evidence for or against its presence in the bedrock structure? PVNGS SSC Additional Documentation Summary of Revisions to Report correct number significant digits. Table 7-4 has been partially revised to include slip rates of 0.001 and 0.005 from Table 7-2 (as well as to include correct number of significant digits in all places). Other slip rates on the order of 10-2 and 10-1 remain unchanged, as the scarp degradation argument is less applicable here. Specific slip rates instead illustrate order of magnitude changes in slip rate and number of faults, with 0.5 mm/yr included for comparison to ECSZ faults. Text updated as needed to reflect these values. See chapter 4 responses. No change to text. Removed "lineament". Agree. Text revised to state no displacement since 2.8 Ma. Given hypothesized breadth of Soccorro fracture zone and scale of geologic mapping, we cannot definitely state that Tertiary strata are not Attachment 3, Page 29 of 53 Date Location in No. Received Report1 140 2/19/2015 Section 7.2.4, Page 7-13 141 2/19/2015 Section 7.3, Page 7-14 142 2/19/2015 Section 7.4, Paqe 7-17 143 2/19/2015 Section 7.4, Page 7-17 and 7-18 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision Yes, young structures cross-cut it, so clearly not active, but it seems to me that an even stronger statement is if Tertiary strata are not affected, and there must be good mapping of the Mesozoic and tertiary strata in that region. Is there a NE-striking bedrock fault or other structure? Same comment in the next paragraph -absence of scarps is a weak statement. Absence of an actual bedrock fault is strong. In the case of the Gila River, the unnamed fault mapped by Gilbert may constitute such a fault in bedrock, and you showed that old Pleistocene surfaces were not faulted. That is a stronqer statement than lack of scarps. " ... possibility of extremely rare ... " What is the {Same) basis for "extremely rare" when it is young alluvium? Also, the last sentence of this bullet is unclear. Comparing northern and southern B&R fault NIA scarps implies similar k values. This may be valid if the climate between the two regions has been the same throughout the time period over which the scarps are evaluated. Is this defendable? 2 mm/yr?? Do you mean 0.2 mm/yr? Please {Same) confirm. Another aspect of creeping faults is that they {Same) typically have abundant microseismicity because, although creep itself may be aseismic, there are usually numerous minor asperities along all faults and these tend to light up along creeping faults. The absence of microseismicity trends (or microseismicity PVNGS SSC Additional Documentation Summary of Revisions to Report affected. Statement about old Pleistocene surfaces added. "Extremely rare" deleted. Parenthetical added to last sentence to clarify. We weren't aware of any studies that made a strong case for differing climates over the timescale in question. No change to text. Fixed. should be 0.2 mm/yr. Sentence to this effect added. Attachment 3, Page 30 of 53 Date Location in No. Received Report1 144 2/19/2015 Section 7.4.2, Page 7-20 145 2/19/2015 Figure 7-21 146 1/19/2015 Section 8. 1 , Page 8-1 147 1/19/2015 Section 8.1, Page 8-1 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision associate with faults) is a strong argument against the presence of creeping faults. "The arid Arizona landscape ... " Yes, it is NIA currently arid, but what about the late Pleistocene. It may have been less arid although CaC03 was still accumulating. This would be a stronger statement if quantified with the fact that secondary carbonate is a component of sB&R soils throughout the middle to late Pleistocene so climate has always been arid to semi-arid, making the case for slow geomorphic change. An alternative argument or concept to think about is that if the climate has been arid for several hundred thousand years, as appears to be the case, the vegetation has likely always been sparse. In that case, would short-term wet periods have a more dramatic effect on the landscape because of the lack of vegetative cover? Just thoughts ..... not sure you want to even address this in the report. What about the bedrock geology? Is there NIA even a fault mapped in the Tertiary or Mesozoic rocks? The absence of a "bedrock" fault would be even stronger evidence against the activity of this inferred structure. Chapter 8 Perhaps this little explanation would be helpful (Same) at this point. Please consider having two bulleted sup-(Same) paragraphs to describe areal sources and fault sources. PVNGS SSC Additional Documentation Summary of Revisions to Report Thank you for the suggestion. We prefer to not introduce this argument though, as it may be a bit speculative. No change to text. No there are no faults of that orientation (on the state-wide geologic map). Text stating that 'there are no large-scale bedrock faults mapped along the trend of the Socorro fracture zone, but several cross-cut this trend" added. No change to text. Text revised to explain areal sources and their logic tree parameterizations. Instead of bullets, we inserted a hard return to start fresh paragraphs for the introduction of areal sources and fault sources. Attachment 3, Page 31of53 Date Location in No. Received Report1 148 1/19/2015 Section 8. 1 , Page 8-1 149 1/19/2015 Section 8. 1 , Page 8-1 150 1/19/2015 Section 8.2.1, Page 8-2 151 1/19/2015 Section 8.2.4.1 152 1/19/2015 Section 8.2.4.1. Page 8-4 153 1/19/2015 Section 8.2.4.1. Page 8-4 154 1/19/2015 Section 8.2.4.1, Page 8-4 155 1/19/2015 Section 8.2.4.2, Page 8-7 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision Please clarify what "location" means; does in {Same) mean "anywhere within the specified areal source zone"? This is referred to as the Sonoran Basin and Throughout Range elsewhere in the report. report. This term was defined as a 400km circular Throughout region centered on the PVNGS site. However, report. it has been called both "model region" and "study region" or both in various places in the document. Please settle on your single preferred name, use it only, and make the appropriate changes in the entire document includinq the qlossary to achieve consistency. Isn't this similar to fault sources?? NIA Due to scientific advances like seismology. So {Same) is this a global issue or just for our region? Also what do you consider to be the duration of the catalog?? This implies a limited duration for the catalog {Same) for the source region of PVNGS. This sentence is overly complex and I've tried {Same) to simply it. Basically, magnitudes for these events are inferred by their maximum intensities, and may contain considerable error. This could be more explicitly laid out. PVNGS SSC Additional Documentation Summary of Revisions to Report Text revised to remove "location" and insert "geometry". The report text has been revised throughout to only refer either to the northern Basin and Range or the southern Basin and Range. The report text and figures have been revised throughout to only use "model region" when referring to the 400 km radius. Yes, this model for the spatial distribution of seismicity in an areal source is similar to a fault source. This model could also define smaller zones. The key concept is that we don't know where within the zone they are located. No change to text. Rephrased to clarify that this is a project-specific issues. Also, the issues is the limited number of earthquakes. rather than duration of the catalog. Rephrased to clarify that this is a project-specific issue. Also. the issue is the limited number of earthquakes, rather than duration of the cataloa. Accepted and further revised. The problem here is not the uncertainty (which is taken into account with E[M] and N*). it is the lumpy nature of the observed recurrence curve due to each MMI value mapping into a specific ErMl value. No chanoe to text. Attachment 3, Page 32 of 53 Date Location in No. Received Report1 156 1/19/2015 Section 8.2.4.2, Page 8-8, equation 8-7 157 1/19/2015 Section 8.2.4.2, Page 8-12 158 1/19/2015 Section 8.3.5, Page 8-19 159 2/17/2015 Section 8.3.5.2, Page 8-23 160 2/19/2015 Section 8. 1 , Pages 8-1 and 8-2 161 2/19/2015 Section 8.3.5.2, April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision This is true for a b-value of 1. Is it strictly true if NIA the actual b-value falls below 1? That's an interesting bias. Is this a form of NIA anchoring? Up to an Mmax of 8.2 (?) (Same) Is this math correct? Seven earthquakes in {Same) 1100 years, but 6 recurrence intervals. 1100 x 24 = 26.4 m. So is the average displacement (between events) divided by 6 (4.4 m) or 7 (3.8 m)? "relatively low slip-rate ... " relative can be {Same) interpreted as several mm/yr -how about very low slip-rate ... ? The Rockwell, oers. Comm. Citation should be (Same) PVNGS SSC Additional Documentation Summary of Revisions to Report Ab-value not equal to 1 is not a problem in this formulation. Only b<O or b=O are problematic. No chanae to text. The result of equation 8-12 (which favors values near is not really a bias. Also, the term anchoring is generally used to indicate a psychological tendency, not a mathematical one. No change to text. Text revised to clarify focus of paragraph. The inclusions of large magnitudes isn't necessarily a reason for using one approach over another. Instead, the paragraph now describes why the use of UCERF3 rupture sets and certain combined fault sources is a valid alternative to the WAACY approach. There are two internally consistent estimates, 6 events and six intervals ending at -1720 AD, or seven events and approximately 7 intervals, the seventh being approximated by the open period. The closed interval (6 and 6) method leaves out the information on recurrence interval contained in the length of the open interval. The latter 7 and 7 method leads to a less biased estimate of the recurrence interval {e.g., Biasi. 2013. WGCEP Appendix H) and a less biased estimate of average displacement. We used the latter approach. It seems to us inconsistent to use the approximate time for seven events (1100 years and counting) to represent six intervals. Parenthetical explanation added to text. Text describing normal faults of the southern Basin and Range revised as suggested. Onderdonk et al., 2013 cited. Attachment 3, Page 33 of 53 Date Location in No. Received Report1 Page 8-22 162 111912015 Section 9.1.1 Title 163 111912015 Section 9.1.1, Page 9-1 164 111912015 Section 9.1.2. Paae 9-2 165 111912015 Section 9.1.3. Page 9-3 166 1/19/2015 Section 9.2, Page 9-3 167 111912015 Section 9.2.2, Page 9-3 168 111912015 Section 9.2.3, April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision changed to Onderdonk et al., 2013, 2015 in review-I can provide the published paper version and the current new paper version Chapter9 Simply stating "Future earthquakes" implies NIA that they will actually happen, whereas they may never happen. Are we not really talking about the plausibility of future earthquakes? Earthquakes that may possibly happen? Perhaps some citations here? (Same) Are there data to support this opinion? What (Same) does reaional seismicitv tell vou? A normal faulting event of this magnitude (Same) would also have to extend for several hundred kilometers, which would cross-cut a variety of other structural features. This would have to be a very complex, multi-segment, multi-fault earthquake The region really is the 400-km -radius "model Throughout region" As far as I recall. this reason for calling report. this the "model region: has not been explained. Early in the report, the 400-k-radius region was called the model region or study region. I prefer using "study region" because it is a clearly understandable terminology. This implies that they are expressed in bedrock (Same) terrain. In fact, they are mappable as geologic structures but may still have no expression of activity. Please clarify exactly what is meant here. Why an M7.2? Landers, as you mention, was NIA PVNGS SSC Additional Documentation Summary of Revisions to Report Yes, they may or may not happen in reality, but we're describing future earthquake that will happen in the model. No change to text. Text revised to only rely on expert judgment. Text revised to include heat flow and reference that ties the base of seismicitv to isotherms. Text discussing Mmax value of M7.9 revised as suggested. The report text and figures have been revised throughout to only use "model region" when discussing the 400 km radius. We prefer this to "study region" because we studied many things that are more than 400 km from the site, but our model is (mostly) restricted to the area within 400 km of PVNGS. The term model region is defined in the first paraqraph of Chapter 8. Phrase describing faults in the East source changed from "poorly expressed outside of bedrock terrain to "poorly expressed". These were provided as ballpark examples of Attachment 3, Page 34 of 53 Date Location in No. Received Report1 Page 9-4 169 1/19/2015 Section 9.2.4, Page 9-5 170 1/19/2015 Section 9.3.1, Page 9-6 171 1/19/2015 Section 9.3.1, Page 9-6 172 1/19/2015 Section 9.3.1.2, Page 9-6 173 1/19/2015 Section 9.3.3.1, Page 9-8 174 1/19/2015 Section 9.3.3.3, April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision M7.3 so shouldn't the largest future earthquake be possibly larger? Centroid depth? The centroid is the average (Same) depth weighted by slip. How can these represent the deepest events? There is a subtle difference in the usage here, (Same) with southern capitalized as a source, whereas in the next line, it is not capitalized when referring to the southern portion of the Basin and Ranoe. Is this correct? In some chapters (or I am confusing with text Throughout from the SWUS GMC), SBR is defined as the report Sonoran Basin and Range. I need to check on this to make sure I am not cross-wiring ... Why is this done? The discussion in this (Same) section seems uncomfortably ad hoc. Primary fault with an antithetic secondary fault? NIA What are paired normal faults? Need to better define these. I can't think of any NIA PVNGS SSC Additional Documentation Summary of Revisions to Report earthquakes that, at the time they occurred, would have exceeded the characteristic magnitudes of the causative faults. We think that the future occurrence of M7.3 earthquakes in the background of the West source is unlikely, however, we still assign a 0.4 weight to M7.2, and 0.25 weight to M7.5 and larger. No change to text. Text revised to remove comparison to earlier regional centroid depths of Goff, and instead cite the depths determined by Castro in his primary study of the Canal de Ballenas area. Text revised to remove reference to the province, to avoid confusion. But yes, capitalization matters. Report text and figures have been revised throughout to only ever refer to the "southern Basin and Range physiographic province" or the "Southern Basin and Range (SBR) source" Corrected text to state that default weights described in 9.1.3 were adopted. These faults are not thought to constitute the typical combination of primary and antithetic fault, rather, they appear to bound keystone style grabens. This suggests they may be very high angle structures. We do not think or mean to suggest they are strike-slip faults, rather, we simply suggest that their orientation allows the possibility that they could accommodate lateral displacement (but not significant displacement). No chanoe to text. We do not think or mean to suaaest they are Attachment 3, Page 35 of 53 Date Location in No. Received Report1 Page 9-8 175 1/19/2015 Section 9.3.4.2, Page 9-9 176 1/19/2015 Section 9.3.5.3, Page 9-10 177 2/17/2015 Figure 9-34 178 2/19/2015 Section 9.2.6, Page 9-6 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision paired strike-slip faults in California, so perhaps it is more likely that these represent very low angle faults. A better discussion on these interesting faults may be in order -perhaps where they are first mentioned in section 9.3.3.1 Mmax don't represent the expected sizes of N/A earthquakes for a source region, Mmax is the largest earthquake that can be expected from a source region. As this region has already had a M7.5, shouldn't this be the smallest Mmax that is considered?? Except that is includes the San Miguel fault in {Same) Baja California, which is transtensional and the source for the 1956 M6.8 San Miguel earthquake. This may not reflect, then, the CBR of the TDI. Are we supposed to know what the Chapter 13 "realizations" are or refer to Case 2 magnitude weights? Usually realizations mean something like model run number. Insert "minor" between continued and {Same) extension (?) PVNGS SSC Additional Documentation Summary of Revisions to Report strike-slip faults, rather, we simply suggest that their orientation allows the possibility that they could accommodate lateral displacement (but not significant displacement). No change to text. Mmax would begin at M7.5 only if we place a high degree of confidence in the interpretation that an 1887 style earthquake is likely to occur anywhere within the Mexican Highlands in the future (i.e., only if we have high confidence that the Mexican Highlands contains active, unrecognized faults capable of 100-km-long ruptures). Areal source Mmax only needs to account for the largest earthquakes not occurring on modeled faults in that source. The weights of 0.3 and 0.05 at M7.5 and M7.9 allow for the possibility that 1887-sized earthquakes may occur in the background of the Mexican Highlands, whereas lower points in the Mmax distribution represent the interpretation that all such large, active faults are accounted for. No chanae to text. Text revised to clarify that future earthquakes are modeled to reflect the dominance of strike-slip faulting and local transpression in the eastern Transverse Ranges. The definition for the term "realization" has been added to the Glossary (Chapter 13). Text describing extension in the East source revised as suaaested. Attachment 3, Page 36 of 53 Date Location in No. Received Report1 179 2/19/2015 Section 9.3.5.2, Page 9-10 180 1/19/2015 Section 10.0. Page 10-1, 151 paragraph 181 1/19/2015 Section 10.1. Page 10-1 182 1/19/2015 Section 10.1, Page 10-2 183 1/19/2015 Section 10.2, Page 10-3 184 1/19/2015 Section 10.2, April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision What about normal faults in Baja -these don't NIA seem to be covered Chapter 10 The Sand Tank fault on figure 10-1 is NIA disproportionately long -shows it as nearly 30 km in length. whereas the scarp is less than 4 km in lenath. The San Miguel fault is transtensive, whereas (Same) the Agua Blanca fault is purely strike-slip. There are no reverse faults mapped or known in Baja California. Transpression in southern California is limited to the region generally north and east of the Elsinore and San Jacinto fault. How about strike-slip and transpressive? Perhaps don't include transpressive and Mexico in the same sentence. Distant fault sources? Long period only N/A Sections kind of replaced "segments", as there (Same) was considerable push-back on the idea of segmentation. Nevertheless, sections/segments were never boundaries, but the section of faults between boundaries. Perhaps it would be better to state that the fault sections were not delineated by primary boundaries to fault rupture. Or separated? Second time mentioned, what is the problem (Same) PVNGS SSC Additional Documentation Summary of Revisions to Report Text states that this breakdown reflects the dominance of strike-slip and reverse faulting in SCABA. It is also designed to model earthquakes on faults not already mapped. We judge normal faulting in Baja to be covered by the faults that are alreadv maooed. No chanoe to text. The Sand Tank fault source in Figure 10-1 includes the longest extent included in the model, consistent with the way all other fault sources are depicted. No chanae to text. Text revised as suggested. Especially at long period. but these are the most hazard significant fault sources in general. Further specifics provided in Chapter 11. No chanQe to text. Text revised as suggested. Sentence deleted. There is no problem with Attachment 3, Page 37 of 53 Date Location in No. Received Report1 Page 10-3 185 1/19/2015 Section 10.2, Page 10-4 186 1/19/2015 Section 10.2.1.1, Page 10-5 187 1/19/2015 Section 10.2.1.1, Page 10-5 188 1/19/2015 10.2.1.1, Page 10-5 189 1/19/2015 Section 10.2.1.1, Page 10-6 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision with FM3.2 that it wasn't used. Right. Why is Dr. emphasized here whereas Throughout many other proponent and resource experts report. that hold doctoral degrees are not indicated as such? Please include DR. for all doctoral resource and proponent experts. Woody's addendum: Per Tom's comment below, I suggest that the project establish a policy for this document along the lines Tom suggests. All the project personnel who have bios attached to the report should not have titles in the text of the report. Consultants, resource and proponent experts should have their titles included in the text. Why omitted, then you say as a result, it's {Same) modeled separately. Yeah, because you already omitted it. What's the logic driving this? Also, figures 10-12 to 10-14 are hard to explain NIA without ruptures extending from the San Andreas fault onto the Imperial fault-how else can the Imperial fault have so many rupture terminations? Is this really known? 1857 -yes. All earlier {Same) earthquakes are debatable. Just so the Tl team is aware of this, but {Same) Rockwell, Oglesby and Meltzner have a SCEC proposal submitted to test (model) whether this is possible, qiven what we know about the PVNGS SSC Additional Documentation Summary of Revisions to Report FM3.2, we were just being clear and specific about the inputs to our model. But the exclusive dependence on FM3.1 is already stated in the previous oaramaoh. Throughout: "Dr." deleted per suggested rule. Rewritten to more clearly reflect the logic of the layered San Andreas fault model. Figures 10-12 through 10-14 depict the fault as modeled according to the UCERF3 rupture set approach, which is why they are referenced in the preceding paragraph and not this paragraph {which describes the layered approach). No chanae to text. Text revised to add "are interpreted to". This statement is based on 1857 termination combined with interpreted terminations from Fumal et al. (2002). Rewritten to more clearly state that this approach is a low weight alternative to UCERF3. Regarding the defensibility of this interpretation, the fact that it is currently the subiect of Attachment 3, Page 38 of 53 Date Location in No. Received Report1 190 1/19/2015 Section 10.2.1.2, Page 10-6 191 1/19/2015 Section 10.2.1.2, Page 10-6 192 1/19/2015 Section 10.2.1.2, Page 10-6 193 1/19/2015 Section 10.2.1.2, Page 10-6 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision structural configuration and paleoseismic record. The paleoseismic record for the southern San Andreas fault MRE is identical to the ca. 1700 event on the Imperial fault. Thus, this interpretation may not capture the CBR of the TDI. Hmmm -20 from the southern San Andreas (Same) fault and 15 from the southern San Jacinto fault equals 35 mm/yr. Based on what? References here? Bennett Section puts 35 mm/yr on the Imperial fault itself, as do 10.2 most geodetic studies. The Thomas and Rockwell paleoseismic study covered too short of a window (2 events) to represent a long term slip rate, and new paleoseismic data indicate a faster rate. 25 mm/yr. is certainly within the ranqe, but is not the center. This rate was for the northern end of the (Same) Imperial fault. Assuming that the large slip events increase in displacement to the south, as did the 1940 and 1979 earthquakes. then the rate at the border could be as large as 35-40 mm/yr. This will be tested with new trenches in January and February (too late for this SSHAC), but the 10 mm/yr at the north end of the fault should not be used for rate estimates as it is north of the split with the Brawley fault and in an area of distributed strain. Okay, so 25 mm/yr on the Imperial fault, 3 on NIA the southern Elsinore fault. Are you then putting another 11 mm/yr on the Cerro Prieto fault and having it cross the border without adding to the Imperial fault, as in figure 10-17, panel A? This needs to be explained in the PVNGS SSC Additional Documentation Summary of Revisions to Report investigation indicates that this interpretation must lie somewhere in the realm of the CBR. Note that, on the UCERF3 rupture set branch, through-going ruptures between the Imperial and the San Andreas fault are allowed (branch weight of 0.8). Text revised to clarify that the Imperial rate is based on plate boundary transects in Figure 10-17. Section 10-2 revised to include more detailed discussion of how geodetic and geologic data north and south of the border resolve about 40 mm/yr of the 50 mm/yr plate rate on the San Andreas, San Jacinto, and Elsinore faults (north of the border) and the Cerro Prieto and Ballenas faults (south of the border). Text revised to clarify basis for tarqet slip rates. Lines deleted as part of this paragraph's revision. This low slip rate did not influence the Tl Team's determination of a model slip rate. See previous responses about slip rate budget. Also, Figure 10-178 (lower panel) depicts UCERF3 fault geometries and stated geologic best estimates, which presumably apply to those same geometries. UCERF3 Cerro Prieto fault source terminates at the border. Therefore, Attachment 3, Page 39 of 53 Date Location in No. Received Report1 194 1/19/2015 Section 10.2.1.4, Page 10-7 195 1/19/2015 Section 10.2.2.1, Page 10-8 196 1/19/2015 Section 10.2.2.1, Page 10-8 197 1/19/2015 Section 10.2.2.1, Page 10-8 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision text. Also, does UCERF3 really extend the 35 mm/yr on the Cerro Prieto fault across the border? Obviously incorrect. I think I used a date of ca. 1715 in my SCEC NIA annual report last year. A SCEC report is better than an e-mail communication. Is there a better reference? These don't add up to 21,842 terminations. NIA What gives? Explanation please. Additional text to describe how to interpret the NIA rapid changes in term of numbers would be helpful. Okay, but the barrier is really at Mystic Lake, NIA which is in the middle of your combined section. The Casa Loma fault should be treated separately PVNGS SSC Additional Documentation Summary of Revisions to Report assuming that the geologic best estimates are meant to apply to UCERF3 fault source geometries, UCERF3 does not suggest the 35 mm/yr rate crosses the border. We agree that a rate of 35 mm/yr north of the volcano is incorrect. But we're simply depicting what follows from UCERF3 geometries and best estimates (which are not UCERF3 model slip rates). No change to text. This date is based on the range reported by Haaker et al., 2013, who reported 1717-1726. No change to text. Notice that there are several colored circles that overlap, in these cases, only the circle on top has the number of terminations listed. Due to this, the numbers shown add up to 20, 725 ruptures. The rest of the ruptures are there. but contained in the overlapping circles. No change to text. These points on each figure represent the number of rupture terminations at each 7.5-km-long subsection for each magnitude range. These rupture sets come directly from the results of the UCERF3 grand inversion, and are the product of a number of constraints. not all of which explicitly described in the UCERF3 report. Therefore, any attempt to explain variations in the number of rupture terminations along strike would be laraelv coniectural. No chanae to text. As currently constructed, Layer 2 in our model produces a close match to your Clark fault (we produce M7 .3 according to Hanks and Bakun, Rockwell et al., 2014 produce M7.2), and our Layer 4 produces a close match to your northern Attachment 3, Page 40 of 53 Date Location in No. Received Report1 198 1/19/2015 Section 10.2.2.1, Page 10-9 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision There is actually a large body of new data. NIA primarily contained in theses, that can be provided to the Tl Team. However, it is quite late in the game. Bottom line -the Superstition Mountains fault fails with the Coyote Creek fault, but the Coyote Creek fault also fails on its own more frequently. PVNGS SSC Additional Documentation Summary of Revisions to Report Clark fault {our M6.9 v. Rockwell et al. 2014 M6.7). The discrepancy appears to be due to the fact that our Layer 1 combines your Claremont and Casa Loma faults, producing one M7.2 fault rather than a M6.8 fault and a M6.5 fault. The effect is that our model reserves more of the available slip rate along the northern San Jacinto fault for large ruptures, rather than dividing that slip rate into M6.8 and M6.5 earthquakes. A more segmented model, as you suggest, may be supported by the paleoseismic data. In the end, the simplistic layered fault model has to incorporate paleoseismic data while accommodating along-strike variations in slip rate. all while reserving enough moment rate for characteristic magnitudes (i.e .. layer lengths) deemed reasonable by the Tl Team. This can be a real balancing act given the competing interests -for example. creating a large number of layers to honor all variations in slip rate can have the effect of reducing hazard by consuming a lot of moment in small magnitude earthquakes. But given the distance from the site, and the relatively low contribution to site hazard from this fault {based on sensitivity analyses), a relatively simple model is justified. No change to text. We didn't have these theses during model development. As such. they postdate our evaluation and integration phases. Constraints that guided the Tl Team's selection of San Jacinto fault layers described in more detail in response to comment 240. No change to text. Attachment 3, Page 41of53 Date Location in No. Received Report1 199 111912015 Section 10.2.2.1, Page 10-9 200 111912015 Section 10.2.2.1, Page 10-9 201 111912015 Section 10.2.3.1, Page 10-10 202 1/19/2015 Section 10.2.3.2, Page 10-11 203 1/19/2015 Section 10.2.3.2, Page 10-12 204 111912015 Section 10.2.3.4, Page 10-12 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision Not supported by paleoseismic data NIA May be true, but new data indicates a through-NIA going strand between the SHF and the CCF that had small rupture along it in 1968. An unpublished trench (student thesis) shows this as a recurrent Holocene fault. And the Whittier fault??? NIA Actually, what we think is happening is that the {Same) Earthquake Valley fault transfers slip from the northern Elsinore fault to the southern San Jacinto fault zone. so the rate on the southern Elsinore fault is only about 2-3 mm/yr, similar to that along the Laguna Salada fault (3 mm/y) to the south. This is reasonable -it has major restraining {Same) steps at both ends. so ruptures probably terminate in the Palomar Mtn uplift in the north, and the Vallecito-Fish Creek uplift in the south (Rockwell et al., 2013) The MRE on the Julian segment is determined NIA from trenching at Julian and Nenshaw to be about 1,700 years ago (Thorup, MS thesis) PVNGS SSC Additional Documentation Summary of Revisions to Report Is this based on the unpublished trench data mentioned in the previous comment? No change to text. Given that the model was essentially completed in June of 2014, new data available since then cannot be readily evaluated and integrated into the model. No change to text. The rupture-set model includes any rupture in the UCERF3 model in which Elsinore sections from Glen Ivy to Coyote Mountain participate. So, this set of ruptures includes a number of earthquakes that extend onto (or from) the Whittier fault as well. It simply excludes those UCERF3 events that ONLY rupture the Whittier fault. No change to text. Text added to clarify the fact that slip transfers from the Elsinore to the San Jacinto fault. Later discussion of modeled slip rates clearly indicates where the model deviates from reality, and why this approximation is necessary. Tom -did you mean Blisniuk et al., 2013? This ref has been added. This comment would apply to the treatment of the layered model, not the UCERF3 ruptures. For the layered model, we did not assign layer-specific EPR values using layer-specific slip rates and tMREs. This reflects the fact that for most lavers, paleoseismic data are not sufficient Attachment 3, Page 42 of 53 Date Location in No. Received Report1 205 1/19/2015 Section 10.2.4.2, Page 10-14 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision This is confusing. According to UCERF3 on {Same) figure 10-17, 35 mm/yr is assigned to both the Figure 10-northern Cerro Prieto fault and the Imperial 24 fault. The upper panel shows 11 mm/yr. In Figure 10-24. there is 10 mm/yr for layer Band 1 mm/yr for layer C, so it adds up. Does this model mean that the northern and southern Cerro Prieto fault segments usually rupture independently? PVNGS SSC Additional Documentation Summary of Revisions to Report to constrain a prehistoric MRE. And if we can't do it for even one layer, we have to abandon the layer-specific approach and instead apply EPR to the composite hazard of the layered model {the same way we don't apply rupture-specific EPRs to the rupture set model, since we can't get slip rate and tMRE for each rupture). This "composite" treatment of EPR for the layered model was applied to both the Elsinore and the Cerro Prieto. This treatment differs from the way the EPR was applied to the layered models of the San Andreas and San Jacinto. No change to text. Text should call out Figure 10-17 (which shows the Cerro Prieto UCERF3 mean solution rate/PVNGS target slip rate of 11 mm/yr in panel A and the UCERF3 geologic best estimate rate of 35 mm/yr in panel 8) and Figure 10-24. This should help avoid confusion regarding where various target slip rates come from. In addition, revised Figure 10-24 adds target slip rates for our layered model that had previously been missing. Important note: Geologic best estimate slip rates were developed by UCERF3 as a guide for the deformation modelers. These are not assigned to fault sources in the UCERF3 model. In fact, slip rates are not assigned, period. Slip rates are solved for by the grand inversion. The result of the grand inversion is a solution rate for each fault model (FM3.1 and FM3.2). The average of these solution rates for a given fault is the "mean solution rate". In the case of the Cerro Prieto fault, the mean solution rate is 11 mm/vr. Attachment 3, Page 43 of 53 Date Location in No. Received Report1 206 1/19/2015 Section 10.2.4.4, Page 10-15 207 1/19/2015 Section 10.2.4.4, Page April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision How can the MRE be 244 years when it N/A ruptured in 1934? We actually don't know if it didn't rupture to the border. The record is incomplete for the Imperial Valley NIA prior to the late 1800's. The penultimate Cerro PVNGS SSC Additional Documentation Summary of Revisions to Report Regarding the last question, yes, only 1 mm/yr (out of 35 available in the south, and 11 available in the north) is assigned to rupture of the entire source, from just north of the international border to the Waoner Basin. The MRE is based on a resetting event that ruptures the full fault length (or layer length, if we are calculating layer-specific EPR). In the case of the Cerro Prieto, we don't have good paleoseismic constraints on the most recent earthquake that ruptured all of layer 1, versus all of layer 2, versus all of layer 3. 1934 may have ruptured all of Layer 3 (from the Wagner Basin across the international border), but there isn't definitely evidence for this. We also can't confidently assert that 1934 ruptured all the way from the volcano offshore into the Wagner Basin (Layer 2). Given this uncertainty, we look at the entire fault length (in this case, layer 3). assign a defensible average slip rate (in this case. 35 mm/yr), and determine the youngest possible age of full-fault rupture. We consider full rupture of the fault from the international border to the Wagner Basin to be missing from the historical record. If such a rupture has occurred, it must have occurred prior to the beginning of the historic period, which we've defined as 1770. Therefore tMRE must be at least 244 years. This model decision ends up being more conservative than if we assume the 1934 earthquake was a resetting event. No chanoe to text. See response to previous comment. We don't have a sense of rupture length or displacement Attachment 3, Page 44 of 53 Date Location in No. Received Report1 10-15 208 1/19/2015 Section 10.3, Page 10-16 209 1/19/2015 Section 10.3, Page 10-17 210 1/19/2015 Section 10.3, Page 10-17 211 1/19/2015 Section 10.3, Page 10-17 212 1/19/2015 Section 10.3, Page 10-18 213 1/19/2015 Section 10.4. Page 10-19 214 1/19/2015 Section 10.4, Page 10-19 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision Prieto fault large earthquake was likely the 1855 earthquake reported in Yuma -produced mud volcanoes alonq the CPF. The earthquake mainshock nucleated on the {Same) southern Laguna Salada fault, at least as maooed. This is only true south of the Paso Inferior N/A accommodation zone. See Rockwell et al., 2014 in review, for the full slip distribution of this earthquake. Rockwell et al., 2014 in review have extended NIA the surface rupture -it is now 55 km in length. Okay, but the 2010 earthquake produced NIA mountain-side-down displacement, whereas the 1892 uplift the Sierra Caucapah. New paleoseismic results confirm a 1-2 kyr RI on the LSF, and indicate a -20 kyr RI for the Borrego fault. Hence, 2010 was a relatively rare event. In spite of only part of this rupturing with the NIA 1999 M7.1 earthquake? How does this come into play? Does the USGS {Same) have a proxy value for lntermountain West normal fault slip rates? If so I don't know about it. Holocene activity is completely independent of NIA recurrence intervals when you are dealing with such low slip rates. In fact, Holocene movement mioht be a oood deterministic factor PVNGS SSC Additional Documentation Summary of Revisions to Report for the 1855 earthquake, and therefore we can't assume it's a resetting event. Using an MRE of 1770 is more conservative. No chanqe to text. Modified to indicate that Laguna Salada also experienced rupture in 2010. This reference was not available during the Tl Team's evaluation and integration of data. No change to text. This reference was not available during the Tl Team's evaluation and integration of data. Mueller and Rockwell ( 1995) noted that 22 km was a minimum, and we state that. No change to text. We realize 2010 was a rare event, but have chosen to model the imbricate set of faults, including the Laguna Salada, as a single fault zone with a rate of 3 mm/yr. We acknowledge that individual elements. such as the 2010 rupture. have a much lower slip rate and recurrence. No change to text. Yes, this is not done to represent past ruptures, but to incorporate the spirit of UCERF3 and allow for connectivity between geometrical simple fault sections. No chanqe to text. Deleted text. The +100%/-50% uncertainty comes from WSSPC recommendations to USGS for Basin and Range normal faults, as stated in the text. Agree, we're just using the description of dePolo and Anderson (2000). No change to text. Attachment 3, Page 45 of 53 Date Location in No. Received Report1 215 1/19/2015 Section 10.4, Page 10-19 216 1/19/2015 Section 10.4.1, Page 10-19 217 1/19/2015 Section 10.4.1, Page 10-20 218 1/19/2015 Section 10.4.1, Page 10-20 219 1/19/2015 Table 10-3 220 1/19/2015 Table 10-3 221 1/19/2015 Table 10-3 222 1/19/2015 Table 10-3 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision for non-activity in the future with SRs of 0.01 mm/vr This has not been explained Section 8.3.3, Page 8-16 The scarp may degrade, but the fault isn't (Same) going to retreat that far unless its bedrock tip is down that far too. It's more likely a basinward reactivation of a lower angle Neogene range front fault. Why so high on the average? If this was an (Same) average, the scarp should be better preserved for a longer distance. It makes more sense that this was max displacement and that the scarp height was much lower along strike to the N and S. This scarp is so far from the range front that it (Same) doesn't even fit that category. 306 or 360? 4590/15 = 360 N/A How do you get an M8 out of a fault area of NIA 4590 square kms? Using Mw=4+LogA gives an M7.66. If I invert for slip and use 4590 square kms (which implies a 360 km rupture length for 15 km of seismogenic crust}, I need 9 m average displacement for the entire 360 km Using Leonard's equation {or Wells and NIA Coppersmith), I get an M7.9 for this fault area. Typical scaling requires about 10,000 square kms for an M8 Should state here that this is NOT based on Throughout PVNGS SSC Additional Documentation Summary of Revisions to Report Definition of the censored instrumental regression from Stirling et al. (2002) provided now in Chapter 8. We agree, we're just relaying the description of the Sand Tank fault from Demsey and Pearthree (1990). Text also clarified. Yes, in response to earlier discussions with the PPRP, the values of 0.8 and 0.2 had been reversed. This is the way the model was run, but the text had not been updated. Thank you for catching this, text revised. Text added to acknowledge the possibility that the Sand Tank fault may not belong to this cateqorv. 306 km taken from length of UCERF3 section, 15 km taken from central seismogenic thickness value for SCABA. 306"'15 = 4590 sqkm. No change to text. Hanks and Bakun (2008) regression is used, 3.07 + 4/3 LogA. No change to text. Hanks and Bakun (2008) regression is used, 3.07 + 4/3 LogA. No change to text. Text revisions and figure revisions should now Attachment 3, Page 46 of 53 Date Location in No. Received Report1 223 2/17/2015 Section 10.2, Page 10-3 224 2/17/2015 Section 10.2.3.4, Page 10-13 225 2/20/2015 Section 10.2, Page 10-4 226 2/20/2015 Section 10.2, Page 10-4 227 2/20/2015 Section 10.2.1.2, Page 10-7 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision UCERF3, as the rest are. Chapter 10. Grand inversion still not defined or explained. (Same) Comment wasn't addressed in previous round (Same) of revisions. This section says must have therefore occurred before ... 1770, which makes the tMRE a minimum not an average. See line 594 = average minimum tMRE value of 244 years States that there is no dependency of slip rate (Same) branches, whereas the preceding sentences look like there is a dependency. Please clarify. "a weight of 1.0." Will this capture the body and NIA range of the CBR? Please elaborate. 3 mm/yr is less than 10% -not 10-15% as N/A stated PVNGS SSC Additional Documentation Summary of Revisions to Report make it clear that the 11 mm/yr target north of the volcano comes from the solution mean, and that this reduction from the geologic best estimate is based on the overlap of the Cerro Prieto and Imperial faults. A brief definition was provided in the previous round of revisions, but more detail has now been added. ">"was previously added to indicate minimum. This has been deleted and replaced with the word "minimum". "Average minimum used to indicate that this MRE value may not be the minimum for all layers -some layers may have a more recent MRE, but since the MRE for all layers isn't known, a slip rate and MRE representative of the full geometry (on averaoe) is applied. Clarifying text added. Dependency within a given layered fault source (i.e., all layers within the San Andreas are dependent), but not between different layered fault sources (i.e., dependency between San Andreas layers has nothing to do with what the San Jacinto layers are doing). As discussion in Section 8.3.3 and summarized in this paragraph, the range of magnitudes produced by the California strike-slip regressions is less than the aleatory uncertainty applied later in the recurrence calculation. Therefore, the Tl Team felt it was appropriate to make the simplification of using a single regression for these faults sources. No change to text. 3 mm/yr is 9% of 34 mm/yr (total available to the north) and 15% of 20 mm/yr (total available to the south). Therefore, we are takino Attachment 3, Page 47 of 53 Date Location in No. Received Report1 228 2/20/2015 Section 10.2.2.4, Page 10-11 229 2/20/2015 Section 10.2.3.4, Page 10-13 230 2/20/2015 Section 10.2.4.3, Page 10-15 231 2/20/2015 Section 10.2.4.4, Page 10-16 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision Please justify the use of 10 mm/yr in NIA calculation of the EPR distribution. as the slip rate is closer to 13 mm/yr. What effect does this have on hazard? The MRE for the Julian segment was NIA estimated at 1700 years ago (Thorup MS thesis)-will this affect hazard? Also, in the next paragraph, the tMRE is 244 -in actuality, the MRE has been determined for all segments of the Elsinore fault zone. Justify using 14 km-thick crust. The 2010 NIA earthquake ruptured only to about 12 km, and the heat flow is higher along the Cerro Prieto fault. This seems a bit deeo. Didn't the 1934 rupture essentially reset the N/A Cerro Prieto fault? Or is this for a full-fault rupture? PVNGS SSC Additional Documentation Summary of Revisions to Report "approximately" 10-15% of the slip rate budget available and applying it to full fault ruptures. No chanae to text. When we were first experimenting with EPR, we found that the results were only sensitive to order of magnitude changes in slip rate. Since that time, we've further observed that the addition of EPR to our fault sources is not hazard significant (Figure 11-24). No change to text. Regarding the last point-individual section M REs would only be useful if they provided a 1 : 1 geometric match to all fault layers. But since our layers represent both single sections. multiple sections, and the full fault, we would need MRE for each one of those geometries. Lacking those data, we decided to calculate a single EPR distribution based on the average fault slip rate and minimum MRE. and apply that EPR to the hazard of all layers. Regarding the first point -due to the potential for missed events (as discussed in UCERF2, appendix F). we decided to default to our historical records date of 1770. Since the application of EPR has been shown to be insignificant to hazard, and the Elsinore is a low-hazard contributor anyway. this will not affect hazard. No change to text. Every fault is modeled using the median seismogenic thickness of the host areal source. In this case, the median seismogenic thickness of the host GULF is 14 km. No chanoe to text. The 1934 rupture may have reset the fault from the international border to the Wagner basin. But given the uncertainty, we defaulted to an older Attachment 3, Page 48 of 53 Date Location in No. Received Report1 232 2/20/2015 Section 10.3, Page 10-17 233 2/20/2015 Figure 10-5 234 2/20/2015 Figure 10-6 235 2/20/2015 Figure 10-8 236 2/20/2015 Table 10-2 237 2/20/2015 Table 10-3 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision Add the Paso Superior fault to the list of faults {Same) that ruptured in 2010. What does "no" mean for the resetting MRE? NIA 14 mm/yr is used on page 10-2 -I am still not N/A clear as to why the tMRE uses a rate of 10 mm/yr The 35 mm/yr section of the CPR was reset in NIA 1934 -this seems to be an issue for tMRE Doesn't the 1887 rupture source fault have a NIA name? Does it matter whether the strike-slip faults NIA really have a 90 degree dip? The San Andreas fault is not 90 degrees for much of these sections PVNGS SSC Additional Documentation Summary of Revisions to Report MRE, which is more conservative with respect to hazard. No change to text. Text discussing the El Mayor-Cucapah earthquake revised as suggested. It means that the MRE used in the EPR calculation for the San Andreas UCERF3 rupture set did not reset the full length of this fault source (San Bernardino South to Imperial). No change to text. As discussed above, EPR was observed to only be significant to order of magnitude changes in slip rate. In hindsight, we could have made this 14 mm/yr to honor the geologic slip rate data. But we know that application of EPR to all of our layered and UCERF3 rupture set faults is insignificant to hazard. No change to text. The 35 mm/yr section was reset. But the short section to the north, and layer combining these sections, may not have been. As discussed above for the Elsinore fault. when lacking MREs for every layer in a given layered model, a single EPR value using a slip rate and MRE representative of the full geometry is applied to the hazard of all layers. No change to text. Yes. but since it's been called both the Pitaycachi rupture {which is incorrect since there are 2 other faults) and the Sonoran rupture (which is the kind of terminology for fault sources we seek to avoid), we call it the 1887 rupture source. No change to text. Given the distance from the site. fault dip doesn't appreciably affect source to site distance. No change to text. Attachment 3, Page 49 of 53 Date Location in No. Received Report1 238 2/20/2015 Figure 10-10 239 2/20/2015 Figure 10-18 240 2/20/2015 Figure 10-20 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision Does UCERF3 not list the San Gorgonio Pass NIA sites by Yule et al? The Imperial fault sites? Lute Ridge? Is this the Clark Lake site? Did NIA UCERF3 really list this as Lute Ridge? Panel (e) is not supported by any data I know NIA of .... PVNGS SSC Additional Documentation Summary of Revisions to Report There is a Cabazon site by Ramzan and Yule (2011) on "San Gorgonio Pass" listed in UCERF3 Appendix G. However we did not include this fault in our model. It is a dead end that branches off of the San Andreas west of "San Andreas fault -San Gorgonio Pass-Garnet Hill", with nucleation rates that are at least an order of magnitude smaller than the rest of the fault. No change to text. There are no paleoseismic sites for the Imperial fault in UCERF3 Appendix G. Lute Ridge is the name of the only paleoseismic site on the San Jacinto (Clark) fault in UCERF3, coming from Salisbury et al. (2012). No change to text. Panel (e) shows layers 4 and 7 of the layered model of the San Jacinto fault source. Layer 4 is an attempt to model the 1918 Anza-only ruptures. Layer 7 models the UCERF3 Superstition Mountain section as rupturing alone. We assume you are referring to Layer 7. Point taken. This is one of those instances where our layered model was more influenced by changes in slip rate along strike, and less influenced by paleoseismic history. UCERF3 Appendix B provides identical geologic best estimate slip rates for Coyote Creek and Borrego (5 mm/yr). whereas Superstition Mountain has a slip rate of 7 mm/yr. In the end, both our segmented model and the segmentation implied by the paleoseismic record are superseded by the connected ruptures produced by UCERF3 (given a weight of 0.8) in Attachment 3, Page 50 of 53 Date Location in No. Received Report1 241 2/20/2015 Section 11.3, Page 11-2 242 2/20/2015 Section 11.3.1, Paqe 11-3 243 2/20/2015 Section 11.3.1, Page 11-3 244 2/20/2015 Section 11.3.2, Page 11-4 245 2/20/2015 Section 11.3.2, Par.ie 11-4 246 2/20/2015 Section 11.4.3, Page 11-6 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision Chapter 11 Please explain why these simplifications are (Same) used (later in this section the phrase "for expediency" is used. This is far from convincing. Please develop a well-stated strategy for using and defending the use of simplifications. Give a sample distance to set the frame of (Same) reference. Could it be 100 km? Please explain and justify what "minor" NIA means-less than?? This geographical area needs to be defined (Same) with an accompanying map. I don't think this has been defined previously. Later in this paragraph there are references to maps in other sections. I suggest providing a map her that shows "greater AZ." and what seismic sources it includes. Define Rrup (Same) It's one of two, how can it be the host (only) NIA PVNGS SSC Additional Documentation Summary of Revisions to Report our SSC model. No chanae to text. Text added to provide justification from NUREG 2117 for simplifying logic trees. The shortest distance between the site and non-host areal sources specified as ">80 km". We intended to keep this discussion general and not get into percent contributions, since these are preliminary results for reference rock (not site-specific Palo Verde rock or soil conditions). Figure 11-15 shows hazard curves for all areal sources with respect to mean total hazard. This figure is not cited at this point in the text, however, to maintain logical order of presentation of oreliminarv results. No change to text. Text rewritten with bullet points specifying those sources belonging to each SWUS GMC region, with figure callouts. Definition added. In each areal source alternative (Two-zone and Seismotectonic), there is one areal source hosting the PVNGS site. In the Two-zone alternative, it's the East source. In the Seismotectonic alternative, it's the SBR source. Attachment 3, Page 51 of 53 Date Location in No. Received Report1 247 2/20/2015 Section 11.4.10, Page 11-7 248 2/17/2015 Page 13-1, "Active fault" 249 2/17/2015 Page 13-1, "Active fault" 250 Page D-27, ANSS Earthquake Catalog April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision How about a concluding sentence or Section paragraph that synthesized the important 11.5 elements of the analysis of this chapter. As now written, you are closing with a whimper. Chapter 12 (No technical comments from the PPRP) Chapter 13 Wasatch has no clear association with (Same) earthquakes but has a robust Holocene history. I don't agree. Most faults called active in the (Same) US are Holocene. Some people use the terms Quaternary and Quaternary-active. Appendix A (No technical comments from the PPRP) Appendix B (No technical comments from the PPRP) AppendixC (No technical comments from the PPRP) Appendix D This date does not seem consistent with the (Same) download date-please explain/correct. PVNGS SSC Additional Documentation Summary of Revisions to Report These two sources also happen to be the most dominant contributors to hazard from areal sources, which is what this section is stating. No chanae to text. Section 11.5 "Summary" added. Phrase "clear association with earthquakes" removed. Sentence "Quaternary faults are generally considered to be active" removed. The ANSS Earthquake catalog was downloaded at several different dates throughout the course of the project. The documentation in Appendix D is now corrected to reflect the most recent download date. Attachment 3, Page 52 of 53 Date Location in No. Received Report1 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision Appendix E (No technical comments from the PPRP) PVNGS SSC Additional Documentation Summary of Revisions to Report Attachment 3, Page 53 of 53

1* ,* Time 1:00-1:15 1:15-1:45 1 :45 -3:45 3:45 -4:05 4:05 -4:20 4:20 -5:00 Topic Introductions Overview of R2. 1 Seismic -Discussion on meeting goals and expected outcome -General Background on 50.54(1) and NTTF 2.1 Seismic -Introduction of seismic hazard PSHA methods and Senior Seismic Ha7ard Analysis Committee (SSHAC) process Presentation of Seismic Reevaluation Report, Overview -SSHAC Activities -Seismic Sources -Ground Motion Model -Interim Actions or Evaluations -Technical Focus Areas and Discussions Planned Break NRC Meeting Wrap up -Technical wrap-up, review focus area, and next steps Public Questions or Comments Speaker NRC!PG&E Co. NRC Jearl Strickland Norm Abrahamson Norm Abrahamson Norm Abrahamson Nozar Jahangir All NRC Public/NRG 2 Safety is and always will be a core value for PG&E and Diablo Canyon Power Plant.

• New and extensive seismic hazard re-evaluation continues to show plant can safely withstand earthquakes.
• Seismic re-evaluation was performed with independent experts in a transparent and open public process.
• Using new regulatory guidance, the latest scientific methodologies and site-specific information, the analysis demonstrates the plant's earthquake design is appropriate and safe.
• PG&E maintains a Long Term Seismic Program (L TSP) for Diablo Canyon, a unique program in the industry that continually assesses seismic safety.
• Safety commitment will continue to be reflected through ongoing seismic study. 3 LTSP Update I Data Compilation and Collection .-------. .-------. Geophysics Geology, Seismicity (AB 1632) (PG&EJ Interpretation Interpretation SSHAC Process Evaluation Integration PSHAU-1 Ground Motion Studies (PEER, SCEC) Published Reports / 4 *Update the seismic source characterization (SSC) and ground motion characterization (GMC) models for use in an updated specific probabilistic seismic hazard assessment (PSHA) *Develop a methodology for obtaining reproducible, stable estimates of probabilistic seismic hazard at a site, including explicit quantification of uncertainty. *SSHAC guidelines are summarized in NRC documents NUREG/CR-6372 and NUREG-2117. *DCPP incorporated new geophysical data into the SSC model, acquired as part of the State mandated AB1632 studies.

SSC/GMC Workshop 1 -Nov. 29 -Dec. 1, 2011 SWUS GMC Workshop 1 -Mar. 19 -21, 2013

• Significant Issues, Available Data, Data Needs
• Included Resource Expert Presentations
• Following March 12. 2012 50.54(f) letter, split SSC and GMC into separate SSHAC studies. . SSC Workshop 2 -Nov. 6 -8, 2012 SWUS GMC Workshop 2 -Oct 22 -24, 2013
• Alternative Models and Proponent Interpretations
• Included Proponent and Resource Expert Presentations SSC Workshop 3 -Mar. 25 -27, 2014 SWUS GMC Workshop 3 -Mar 10-12, 2014
• Preliminary Model and Hazard Sensitivity
• Included Proponent Expert Presentations 5

. § f. \J t:l "' "' .. . .... , ... '* .. * . . . * . *, ', '*. ocrr o. 6 LEGEN "'008 rHa,oebec D k 201)) ty 1987 10 .. Se1sm1c1 D 8C-99 -* 0 0 -1 :} 10 c -It 9 D Z0-39

• f .
• 120-1).9
• D 40-s3 c. .
• 140. D 6.o. *9 1* ,* CCCSIP Study (PG&E)
• Offshore 2D/3D Seismic-Reflection Data
• Onshore 2D/3D Seismic-Reflection Data
• Updated Geologic Map Data Relocated Seismicity Catalog (J. Hardebeck, USGS) Offshore 20 Seismic-Reflection Data (S. Johnson, USGS) Offshore high-resolution bathymetry data (R. Kvitek, CSUMB and S. Johnson, USGS) GPS Velocity Field (J. Murray, USGS and C. DeMets, UW) 7 8 New Models
• Uniform California Earthquake Rupture Forecast, Version 3 (UCERF3) -USGS, CGS, SCEC
• Offshore Hosgri fault slip rates New Methods
• Rupture Sources: Incorporate earthquake ruptures that involve multiple faults
• Composite earthquake magnitude-frequency distributions (Wooddell et al, 2015)
• Fault geometry models that correlate geometric uncertainty
• Capture time-dependent behavior and uncertainties
• Virtual faults within the host areal source zone 8 1* ,* Primary fault sources
• Contribute most of the hazard
• Hosgri, Los Osos, San Luis Bay, Shoreline faults Connected fault sources
• Can link (rupture with) Primary fault sources
• E.g., San Gregorio, San Simeon, Wilmar Avenue, Oceano faults Regional fault source
• San Andreas
• UCERF3 faults
• Additional non-UCERF3 faults Areal Source Zones
• Regional source zone
• Vicinity source zone
• Local source zone 9 I' .1" '" , Virtual faults capture uncertainty in location, dip, sense of slip for other known and possible faults a 2 a . ,,11.1* \ "11" ""-\ '\ ' ' ' ' " ' Vicinity source zone boundary *121.1" -tit* 10 *12'!.t" -120 ,. \ *1206' . \.' \ '-.... \ 'I \ \ .. \ ;II \ ' '* "* "*.:.: ** ... *120.9" :-.: *120.6' NRG SSC Topic 1: Summarize the key data used to constrain the slip rate of the Hosgri fault, including associated uncertainties.
• Four slip rate sites
• Three new sites offshore
• Uncertainties developed for each site
• Sites are weighted for final uncertainty + ..... ().. t-. \ "' \ I \ \ \ 'f' \ \ \ \I ,,.. \ \ *lll"t' **. *Fr ,'\ncisco " . "W 11 IC' ,, . . . :-J: ..... . ... ! .. . . . ... 20 ... : + . . . . : ... *O . .., :"' . . . . . . . . \ *4 \ De \ \ \ \ \ \ . . . . <:Cayucos LosOsos D DCPP
• San Luis Figure extent EXPLANATION -*** * *
• r .,, 11* *: :. * .-*-,., .. 11 I:" ;J ... 1 ::;, :. *1.:.1 I ,._ ! ... *, 'u : : ' .. : ** :. * * * .... 1;1 ., : ... , , ,, ., , .... 11* ., I *. .-*' .I l,o*l 1'1,1 .-,.-.: ., *:I-*! I' : ** * l ., .' *** '1 ,. * :;,* ., ;.. *-rr ,,. I' Ch*nnel Oepth '**'*lll*IJ * *** *'; .\*.,.**I* '***+* ! '*' ,*.,: :1r*.-; rro I r:ro ;1.*rn'.*. *,h;11):t**. * *r*** * *r .-:* 1 .... ; * , ...** ** ;n ** 11' 1*,1*; ir. *!*r* r11.-*n **1 *' ,* * : ,, ,'.* ; 'r .. , '.l1* : * ,11* ' ;,.* II Lo;**: *:** .* 1h* *11. * ...... ,. " I: .. * -* .. , *,,.,,, :-1* .. , l::*I* .* 1 * .* ,., .. .,.,:I ... I ... , .. 1 ** *.,*J' * *. , ... I ,.* , . ._.,:.*no*.** fn1 1*.o,*11 ':: *:*. *. *. : ..... . ........ 11 ** '.\ ... : .. ..... J '.:It*:, .. :, '*, **. *' ,*' *:. *1 ,.<'!.'*.**.: :1 .. *r: *;*: .. **111. '.,1:,J ;.111: '.*II'.* llf .. **t .. *,:,; :.C:DC ... ,,, soo N A c ..io: Estero Bay: Piercing Point DBw-Ee1-De Separation and Uncertainty OCPP SSC REPORT Pacific Gas and Electric Company Figure 8-25 ... 12 1* ,* (a) Offset PDF 0.12 0.10 0.08 >-ii 0.06 0 ... a.. 0.04 0.02 0.00 0 13 Documentation of Offset Uncertainty (b) Justification for offset PDF West Strand Value Offset (m) Basis South margin or the shallo"N West strand off set Min. 450 channel-like feature and the limits of uncertainty in the projection of Channel Ee1 -East strand offset Preferred 770 Range estimated from direct projection of Channel Ee1 and Preferred 1,050 margins of shallow channel-like feature west of fault 10001 North margin of the deep Max. 1,730 channel-like feature and the limits of uncertainty in the projection of Channel Ee1 East Strand Value Offset (m) Basis Min. 200 Estimated from incorporating uncertainty in projections Preferred 230 Range estimated from the .,,----direct projection of Channel Ee1 .,.,... --and De thalwegs -Preferred 290 .,.,... -; -250 500 750 1.000 1.250 1,500 1,750 Estimated from incorporating Max. 320 uncertainty in projections Offset (m) 1* ,* (c) Age PDF 0.010 0.008 :c 0.006 Ill .Q e A. 0.004 0.002 0000 0 250 14 Documentation of Age Uncertainty (d) Justification for Age PDF Value Age (ka) Basis Min 340 MIS 10: youngest age of overlying unconformity Pref. 535 MIS 14; 2:5 transgressive Low End uncon. in strata above channel Preferred 630 MIS 16: probable end of MPT MIS 20; shelf progradation Preferred 800 deeper sea level during late stage MPT Pref. 1,000 High end of uncertainty in High End shelf progadation Max. age of NTN Max. 2,500 unconformity (PG&E. 2014 Chapter 3) 500 750 1.000 1250 1.500 1.750 2.000 2.250 2,500 Age (ka) 1* ,-15 Slip Rate CDF for Estero Bay Site (e) Slip Rate CDF (f) Summary Statistics 0.9 0.8 Cumulative Slip Rate Probability (mm/yr) :>. 0.7 -0.05 0.8 :c 0.1 1.0 !ti 0.6 .c 0 0.2 1.2 ... a.. Q.) 0.5 0.5 1.7 > :;::::; m 0.8 2.2 ::I 0.4 E 0.9 2.6 ::I u 0.3 0.95 2.9 Minimum 0.3 0.2 Maximum 5.3 0.1 Mean 1.7 0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 Slip Rate (mm/yr) 1* ,-Weighting of Four Study Sites CBR of TOI (in mm/yr): Center: 1.7 (wtd. mean) Body: 0.8 to 2.6 ( 1 0°/o, 90°/o) Range: 0.4 to 3.4 (1°/o, 99°/o) >. ..c C'G ..c a.. QI .!!! :I E :I (.) 0.9 0.8 0.7 0.6 0.5 0.4 0.3 I 0.2 I 0.1 I / 0 0.0 0.5 1.0 1.5 2.0 I Slip Rate CDF I I I 2.5 I I I I I 3.0 Slip Rate (mm/yr) / 16 -San Simeon I Oso Terrace Weight (0.3] --Point Estero Cross-Hosgri slope Weight [0.2] Estero Bay submarine channel Weight (0.3] Point Sal Channel F Weight [0.2] -Weighted Hosgri slip rate 3.5 4.0 4.5 5.0 5.5 17 NRC SSC Topic 2: Clarify how elements of the thrust! reverse interpretation for the San Luis Range Thrust are incorporated into the SSC. *San Luis Range thrust model proposes that the Irish Hills are uplifted by a northeast-dipping thrust fault *SSC model incorporates this model as one of three alternatives of uplifting the Irish Hills 3 for Hosgri; 3 for San Luis-Pismo Block Alternative Fault Models: 18
• Describe the fault geometry for each tectonic model in a correlated way
• Dip variability is achieved through the differences between tectonic models NRC SSC Topic 3: Clarify how the rupture models are derived from the fault source geometry models. Fault Geometry Models (FGMs) describe the fault locations, dips, and senses of slip Rupture Models describe the alternative locations on the FGMs where maximum earthquake ruptures and smaller, floating ruptures occur.
• Represents aleatory variability in how earthquakes rupture the fault network
• Allows single-and multi-fault rupture in a standard, forward model
• Rupture models include sufficient rupture sources such that the range of alternative types of ruptures are sampled for adequate source and ground motion variability 19 I' '" *-Rupture Models Allow multi-fault ruptures New composite frequency distribution (a) "20 (b)M,.., N A 0 10 20 -mo w "" 0 10 20 .,,,., *. -M l""iJi Magnitude I' '" *-NRC SSC Topic 4: Summarize the Methodology Used to Define the Equivalent Poisson Rates. Motivation: Non-Poisson Recurrence Behavior is Likely
• In some cases, paleoseismic recurrence records are inconsistent with a Poisson process
• Renewal process includes intuitive physics (elastic strain accumulation and release)
• Simple models available that simulate renewal-type behavior (a) (b) 08 0.6 04 02 0 0 0.5 . 21 Exponential .* / .. *. ;;;,.. . .*' .*',1' ' .. ** ... * . ,.****.: ...... . 1 2 3 4 Normalized time Lognormal, a= 0.6 2 3 4 Normalized time 22 Methodology: 1. Lognormal model for recurrence (also BPT, Conditional Probability Ratio Weibull) 2. Requires estimates of long-term mean (LTM), coefficient of variation (CV), and time since the 2 .... .. ...... -. most recent event (Tmre)
• CV range from global paleoseismic data (mostly California) *
• Tmin constraint on Tmre from historical record (SLO Mission) LTM from slip rate and simple slip/event model 3. For each CV and slip rate, model considers joint probabilities of correct LTM and Tm re 4. 3-pt. approximation of resulting CDF is used in the logic tree for an EPR c.. ,.:* . z ,...* __ en .* .,_,7-------. -. ----*-.. _ . o ,,, .. _ --2 1 ;< / ./ ..... *:-*.-,._. ..... * ........... . CL , *---. ---* ----() I / ....... : -. *:---*-*-*--*------* ,*' / ... ....... .* 0 2 Normalized time EXPLANATION --c;=Q4 ---o*Ot. --o=CS ---o=l 3 4 IC' ,, Use of survivor function to constrain L TM, Tmre joint probability (CV:0.6 shown) (a) PDF 1:;o i'i 2x10<* --ltm:500 ---ltm: 1.000 1.5x10° * * * * * * --* * --* * ... * * .. * .. *
• ltm: 2.000 2l 1 x1 o*l e a.. 0.5x1 o<* I I .* ...... ... 0 1tc.......:__ __ 0 2,000 4.000 Time since MRE (c) 30-Year Conditional Probability 0.2 a.. 0 015 0.1 0.05 0 0 ,, ' . . . ' . . ' 2.000 --ltm:500 -pois500 ---ltm 1000 -pois 1,000 * * * * * *
• ltm: 2,000 -pois2,000 4.000 Time since MRE (b) Survivor Function .q .0 ro .0 e a.. \ ., .. \ 0.8 .. \. 0.6 ... \ 0.4 ... 0.2 0 0 . *., .. 2.000 4.000 Time since MRE . . '. (d) 30-Year Conditional Probability Ratio to Poisson 2 Q 1ii er :.0 e 0.. (;j 1 . . ,. . I , : ., .'. ..... c 0 :g 0.5 I.; ............................... . c 0 (.) 0 0 I : I : 2.000 4.000 Time to MRE 23

(/) ro Q} 1* ,* 3,000 ..... . 2.000 1.000 . 1,000 CP Ratio, LN RI Model, CV: 0.6 2.000 3,000 4.000 Time since MRE (years) . . . co \. 0.81 0.27 5,000 Note: Contours are the ratio of time-dependent rate to time-independent rate. The long-term mean distribution is uniform on the range shown. 24 Joint L TM-tMRE Weighting Probability 4000 . :::oJ 3.000 4.::co Time since MRE (years; EPR Logic Tree, Hosgri fault 1.9 [0.25] 1.3 [O.S] 0.3 [0.25] Reference rock ground motion model (SSHAC GMC)

• Median ground motion
• Aleatory Variability Site Amplification
• How the ground motion at the control point differs from the reference rock ground motion Capture Uncertainties in each part
• Epistemic uncertainties 25 26 Data
• NGA-W2 strong motion data set (PEER)
• European strong motion data set (RESORSE)
• Finite-fault simulations close to large earthquakes (SCEC) Models
• Median GMPE: NGA-W2 GMPEs
• Median GMPE: European and Japanese GMPEs
• Aleatory variability: Mixture model Methods
• Sammons map approach to develop weights for GMPEs
• Additional epistemic uncertainty added to all GMPEs
• Included comparisons with empirical data and finite-fault simulations (SCEC) as part of the evaluation of the weights
• Single-station sigma approach
• Improved treatment of uncertainty for empirical DCPP site terms 27 ' "'C ..... 0.001 ro N ' ' ro I ro ::::J c:: c:: 0.0001 mean ( 5 Hz) \ \ <( ' 5th 15th \ \ 0.00001 50th ---85th \ l \ 95th l \ l 0.000001 0.01 0.1 1 10 Spectral Ace (g) 1* ,-0.1 DCPP: 10-4, S Hz CDO onxIXIDCIDO 0 0 0 00 GM Ratio (Sens/Bue) 0 0 0 0 0 000 000 en:> 00 0 * *
• 0 0 0 1 *_,Common-Form Models *:*Total Sigma *_;Dataset _*Tau * .' PhiSS Dataset *.*Phi Eps. CA *_*Phi Eps. Global *;Mixture-Low :_-,Mixture-High *:.*Phi SS Mag-Dep.
• _
• HW Models *_*HWModel 13 *
• HW Model 23 *_;Directivity Model S *:1 Directivity Model 13 * ; Directivity Model 23 28 29 NRC GMC Topic 1: Provide additional detail in the criterion used for the selection of candidate Ground Motion Prediction Equations (GMPEs) for development of the common form median ground motion models for DCPP. Specifically, please elaborate on the basis for including GMPEs based on data sets other than NGA West-2.

NGA-W2 NGA-W2 NGA-W2 NGA-W2 NGA-W2 Europe & ME Abrahamson et al. (2014), referred to as ASK14 Boore et al. (2014), referred to as BSSA 14 Campbell and Bozorgnia (2014) , referred to as CB14 Chiou and Youngs (2014), referred to as CY14 Idriss (2014), referred to as ld14 Akkar et al. (2014a, 2014b), referred to as AS B 14 Japan & CA Zhao et al. (2006), referred to as ZH06 Japan & CA Tl Team implementation of Zhao and Lu (2011 ), referred to as ZL 11 30 Consider all modern GMPEs from active crustal regions *Assumes that the magnitude and distance scaling in active crustal regions is similar around the world 31

• Selected GMPEs had to meet 7 criteria (SWUS, section 5.5.2) -Most recent version -Not an adjustment of another model -Functional form extrapolates in a reasonable manner -Do not combine data from active crustal and subduction earthquakes -Not just a research tool -Not developed for a very small region -Peer reviewed
• The objective is to capture the uncertainty
• GMPEs from other regions may provide alternative credible scaling for ground motions in CA
• Early feedback from PPRP recommended that we not limit the GMPEs to NGA models because there models may not capture the full range of uncertainty
• Some of the large magnitude data in the non-NGA GMPEs are contained in the NGA data set, so there is overlap, but also different modeling approaches used
• The weights for the final models are developed considering how well the models fit the NGA data 32 NRC GMC Topic 2: Provide additional detail on the development of the common functional form used to fit the candidate GMPEs. Specifically, please discuss how model parameters such as depth to Vs equals to 1 kmls and 2.5 kmls (which are present in some of the candidate GMPEs) are accounted for in the functional form. 33 The common-form models
• Developed for a single reference rock condition of VS30= 760 mis
• Footwall side only to keep the functional form simple
• Hanging-wall effects added to the common-form model The other site parameters, Z1 .0 and Z2.5, are set to their default values for VS30=760 mis
• Basin depth is not a significant issue for soft-rock sites 34 35 NRC GMC Topic 3: Provide additional detail on the approach for weighting the selected common form models as well as the criteria used to verify the physicality of the final model. 2000 models generated to fill in the space of possible GMPEs
• Sampled the covariance of the coefficients
• Treats the correlations of the coefficients Non-physical models *Tails of distributions of coefficients may lead to sampled models that are "unphysical"
• Defined as models for which the magnitude or distance scaling is not monotonically increasing (M) or decreasing (R)

I' '" *-,........, (\,( Cl) --1 0.5 <( C) a_ 0.2 ./ 5_0

• BSSA14 D CB14 5.5 6_0 Magnitude RJs = 30_ strike-slip V S3D = 760m/S 6.5 7.0 36 Measure the Standard Deviation of Difference in GMPEs for a Range of M,R 1* ,* =! :i .5 10 0.0 -0.5 th .... 5 .5 T = 0_01 NGAW2oc-MED 1.0 -0.5 0 ***95-T = 0.01 SI Moc-MED _._.:::--.., "l ID T = 0.01 NGAW2oc-Me.o 0.$ "' O.D .s 1.ol1-=-o -* In unrts ---1.0 r -1 . 5 0 -0. 5 0 t. 1*0 In units
• 0_5 1.0 1_5 37 -. I ..

APPROACH DATASET 0.75 NGAW2£<*MH* 0.67 Data Comparison 0.25 0.33 ---GMPE Prior WEIGHT STATISTIC 0.60 R .d I es1 ua 0.40 --.... Likelihood 1.0 ------Residuals 0 ---Likelihood 38 0.01 0.001 0.0001 le OS IC' ,, Hazard Curve: 5Hz . . . . . . . . . . . . . . . . . . . . . . ."'**,,, '>**. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ... ... ****. .... ..... ----........ ---....... -. ---: : .... <_*-.... -> ....... -:---MOl M03 MOS M06 M07 M12 M13 Ml4 MlS M16 M17 M18 M20 M22 M23 .................. **********************'\\************* \ 1\\ ........ . '\ \\ M24 . . \\ "* M25 \\ M26 \.\ M27 '* M28 \\ M29 . M30 *\\ M31 . . . . . . . . . . . . . . . . Mean Model ....... '*l A SK : , Al4 *********** <!. CB14

• l \\. CY14 -* ld14 ....... \ \ > ZH06 ********* * ** * -* * * * * * * * * * * * * * * * * *. * * * . \ Zlll *********** : 0.1 PSA{g) 0.01 0.001 0.0001 le OS 0.1 Hazard Curve: 0.5Hz .. \ **-...... . PSA{g) MOl M03 MOS M06 M07 MOS M10 M12 M13 M14 MlS Ml6 M17 M18 M19 M20 M21 M22 M23 M24 M2S M26 M27 M28 M29 M30 M31 39 Meao Model ........ ASB14 ASK14 BSSA14 .......... . CB14
• CY14 ld14 ....... .. ZH06 --***--** ZL11 ......... .. GK14
• 10 NRC GMC Topic 4: Provide additional detail on how the continuous distribution for total sigma was developed by combining the between-event and within-event aleatory variabilities. 40 Model M-Dependent 1.0 M-lndependent 0.0 Aleatory Vari ab i I ity High (95°/o pe1*centile) Oa2 Centl'al O .. fi Low (5°/o pe1*centile) 0 .. 2 41
• -1 * ' 'it 42 Dataset Model I I <t>ss Estimates Directivity Aleatory Adjustment Distribution Form 4>ss-CA*l 0.5 High Califomia {95% percentile) Yes. Central Mixture Model 0.67 ff.2 0.0 0.8 4>ss-cA-2 European Central 0.5 4>ss-GLOBAL* RSO (J. i) 0.0 1.0 Low Global (5% percentile) No Normal 0.33 0.2 1.0 0.2 M-Dependent 0.0 Use Chi-Squared distribution for phiSSJ\2 and TauA2 For each model (branch 2) of phiSS logic tree, sample the three PhiSS values and the three tau values Develop a cumulative distribution function (CDF) 43 Average the CDF using the logic tree weights for the alternative PhiSS models (branch 2) and data sets (branch 1) Sample the total CDF at the 5th, 5Qth, and 95th fractile levels 1* ,* ::-. -:.B ro a. 2 a.. 4l =--ro ::::l E ::::l u 0 ..... (0 0 0 'V 0 N 0 0 0 0.0 44 Usinq California Model 1 Usinq California Model 2 Usinq Globa I Weighted Composite 0.2 0.4 0.6 0.8 1.0 NRC SA Topic 1: Section 2.3.2.1 of 50.54(f) Submittal states that shear modulus and damping curves are not directly applicable to DCPP since analytical modeling is not used and that non-linear site effects are implicitly included in the empirical GM,PEs for Vs30 = 760 m/sec. However the NGA West 2 data base has a limited amount of data for sites with Vs30 near 760 m/sec and for earthquake with magnitude and source to site distance similar to those dominating the hazard for DCPP. Please provide additional information on how these limitations in the NGA West 2 data base are accounted for in site response model for DCPP? 45 Nonlinear Site Response in NGA-W2 GMPEs Some GMPEs used analytical modeling for noninearity. 150 125 If) O'> c :0 100 ..... 0 (..) <1> a: 75 -0 ..... Q) .0 50 E ::J z 25 0 0 0 0 0 C\J (Y) v I 0 0 C\I 46 0 0 0 0 l{) l{) 0 0 ""'" CD ()} ""'" ' ' . ....... 0 0 0 0 I (Y) I.[) I.[) 0 .q-CD 0 O> VS30 (mis) 47 NRC SA Topic 2: Section 2.3.6 of the 50.54(f) Submittal describes the development of the site terms for DCPP. For the calculations of between-event residuals, provide additional information on the criteria used to determine the appropriate distance range(+ and-Rrup) to the sample station. Please discuss the sensitivity of this distance range on between-event residual values. Please provide an example calculation that uses site specific values to determine the values for Phi s2s including the epistemic uncertainty in the site term.

48 Non-ergodic ground-motion model InSA0bs(Mi, Loci,Sitej) ==In GMPE(Mi, Rij, VS30 j) + <5L2L1 + <5S2S1 + <5P2Pu + <5Bi0 +ow,; Estimate the combined source and path terms for each earthquake using observations from other sites (not DCPP) 49 <5S2Sj = InSA0b.JMi,Loci,Site)-InGMPE(Mi,Rij, VS30) -(<5L2L1 + + <5P2Plj )+ Sources of Uncertainty of Site Term

• Uncertainty in the Event-specific source and path term:
• Randomness of the remaining aleatory variability of the event term Two factors
• Distance range that includes the DCPP distance
• Distance range for which the residuals do not have a strong distance slope 50 1 0.5 -(/) 0 :!:: c 0 :::I *
• z ....J -. .., 1.5 1 0 0 0 cg " . . . . . . . Q)o 04 oe n. " . . '-'* -. . . v 't 00 0 0 o '-' 0 0 0 0 0 co " 0 10 100 Rupture Distance (km) 1000 51 o San Simeon * -* * *
• DCPP Mean Path & Source Term plus SE minus SE 2 1. 5 1 (j) 0.5 :!::::: c :::::; 0 z ctS :::::; :0 -1 (/) -1.5 2.5 -3 1 --00(; (fr ,... r. I(!) 0 0 hr. , -v 0 rll 0 0 IV ,.... ..... ( 0 ,..j 1,.... q, 0-_1 c r\) ,...,_ VO vo u 0 9i '-' b 0 * *
• u 0 0 .. *'-'. (ii 0 n 0. ,...... cP () 9:> 0 (} In uo 0o 0 -0 10 100 Rupture Distance (km) 1000 52 o Parkfield e DCPP -* * *
• Mean Path & Source Term plus SE minus SE 53 Computed from the standard deviation and number of recordings used to estimate the term *San Simeon: 8 recordings, Sigma= 0.68 In units
• Parkfield: 16 recordings, Sigma= 0.55 In units Epistemic uncertainty is the standard error of the mean
• Sigma I sqrt(N) 0.25 for San Simeon 0.14 for Parkfield Std Error of JS2S DCPP = NEQK L SE(Source +<Pc; i=] = 0.22 NEQK 1960 54 DCPP Seismic Design/Licensing Basis History 1985 U-1
• March 2011 *
• 1986 U-2 *June 91 Nov. 2008 *Fukushima Event. -. . . . . March 2012 1968 & 1970 83 . In operation SSER 34 AB 1632 NRC NRC Fukushima Construction Permits DVP / IDVP (Accepting L TSP) Hazard Rll 09*01 50.54F NTTF 2.1 Evaluation SFZ Seismic Update I DE/ODE j + Hogri (w/Sig. Mods.} + LTSP Study DE/DOE/ Hos+ LTSP Margin AssessmentC I 1971-1976 Off-Shore Hosgri ID/Validation 7/88 1984 LTSP Report I Submitted 1 LTSP May91 LTSP Program License Condition Committment (Shiffer) Nov. 2008 2015 Oct.2012 Shoreline Fault \Rf RII. 12-01 I SFZ)Discovery Jan 2011 AB 1632 SFZ Final srz Seismic Report to Studies NRC Report !Sep. 2014)

DCPP was licensed prior to App. A to 10 CFR Part 100 (Introduced "OBE& SSE" terms) DE: OBE Equivalent= 0.2 g DOE: SSE equivalent = 0.4 g HE: Largest design ground motion= 0.75 g L TSP: Seismic Margin /L TSP Spectra= 0.83 g 2.5 2.0 -1.5 en -c .2 -f 1.0 (I) (J (J < 0.5 0.0 0.1 -LTSP -DE HE v r... ........ --DDE v " -HE(UFSAR) .15 ----HE (EX1rapolated) \ / I """"'11. \ I j [ 1()1 , v .\ _J /; .... , I * / \ __,/ [I 1.0 10.0 Frequency (Hz) ' " " IJ 55 .83 .75 .40 .20 100.0 GMRS Vs. 1977 HE Design u 0 0. "' 010 ' ' 'J ,lj p -GI.IRS -HE1.rS'.P.; ***HE 1 -) I ' ' --Frequency IHz) 56 GMRS Vs. L TSP Seismic Margin I -LTS' SHmc ... ' I\ I \I ...... \ \ I '\ I\ \ I I r-...... ...... -ll I/ :s :.o : .. 10 1.00 lO:l: 100 :o Frequency IHz) 57 3.0 urs b irn Margin 2.5 19 IE \ l/' ----I\ ' ,\ ) v r-... G MR s 2.0 ,/ I/ ...... \ v I ... J ' / \ "\ I * ........ 11 __/ lo.. I

• I I ,I DOE j '-1.0 0.5 0.0 0.1 1.0 10.0 100.0 Frequency (Hz.)

L TSP Licensing Background

• DCPP License condition No. 2.C.(7) required in part "PG&E shall develop and implement a program to reevaluate the seismic design bases used for the DCPP"
• Seismic reevaluation effort was titled Long Term Seismic Program (LTSP); issued in 1988 with 1991 addendums to address the LC and committed to maintain the program going forward. 58
• L TSP deliverables were Seismic Probabilistic Risk Assessment (SPRA) and Seismic Margin Assessment (SMA)
• NRC's comprehensive assessment and acceptance are documented in Supplement 34 to Safety Evaluation Report (SSER-34)
• Key Points -From SPRA; Mean Seismic Core Damage Frequency (SCDF) was calculated to be 3. 7x 1 0-5 59
• Current SCDF (including updated; data, logic model, HRA) is 2.66x10-5
• SCDF sensitivity review considering updated Hazard (with the original Fragilities) is -2.06x10-5 . The fragilities will be revised to get updated risk values. -The fragilities and HCLPF capacities are based on 5°/o damped horizontal spectral acceleration values, averaged over 3.0-8.5 Hz. (-1.94gs) -From Seismic Margin evaluation; the Lowest, High Confidence Of Low Probability of Failure (HCLPF) of SSCs was determined to be 2.62g resulting in a minimum seismic margin of 1.35. -NRG reviewed and acknowledged the significant seismic margin in SSER-34.

Expedited Seismic Evaluation Program (ESEP):

• The GMRS is recognized as beyond design basis. However there needs to be reasonable assurance of plant safety while new/updated risk evaluations are in-progress
• Developed to address where significant exceedance beyond design basis are identified in the 1-1 OHz. frequency range.
• The GMRS is effectively bounded by the 1977 HE design spectra in 1-10 Hz. Minor high frequency exceedance is well within the L TSP seismic margins and adequately considered in the SPRA analysis. Therefore there is reasonable assurance of plant safety. Spent Fuel Pool Evaluation:
• SFP structure is an integral part of the Auxiliary building, which has been designed and evaluated as a seismic Design Class I structure in accordance with the DE, DOE, HE design criteria, and considered in the SPRA (Building fragility). Therefore, there is reasonable assurance of structural integrity. DCPP will perform rapid drain down evaluation activities, as required per SPID and will reevaluate the fragilities for the Auxiliary building as part of SPRA update. 60 Proceeding with SPRA Update/Upgrade -Updating building models (3D FEA) -Updating SSI models -Developing Building FIRS -Fragility evaluation preparation -Updating/upgrading the SPRA model Next Actions -Determine Risk evaluation Prioritization (NRC) -Obtain agreed upon Hazard (GMRS) to proceed with the SPRA (NRC) -Complete Seismic Risk Assessment (PG&E) 61 GROUP AFOIA/PA NO: 2015-0294RECORDS BEING RELEASED IN PARTThe following types of information are being withheld:Ex. 1 :L---l Records properly classified pursuant to Executive Order 13526Ex. 2:f- Records regarding personnel rules and/or human capital administrationEx. 3 :[---] Information about the design, manufacture, or utilization of nuclear weaponsE---]nformation about the protection or security of reactors and nuclear materialsE--iContractor proposals not incorporated into a final contract with the NRCE--OtherEx. 4:E-- Proprietary information provided by a submitter to the NRCV-]OtherEx. 5 :r- Draft documents or other pre-decisional deliberative documents (D.P. Privilege)El Records prepared by counsel in anticipation of litigation (A.W.P. Privilege)El Privileged communications between counsel and a client (A.C. Privilege)El OtherEx. 6:El Agency employee PII, including SSN, contact information, birthdates, etc.EThird party PII, including names, phone numbers, or other personal informationEx. 7(A):El Copies of ongoing investigation case files, exhibits, notes, ROI's, etc.ElRecords that reference or are related to a separate ongoing investigation(s)Ex. 7(C): *Special Agentor other law enforcement PIIr-]PII of third parties referenced in records compiled for law enforcement purposesEx. 7(D):f-lWitnesses' and Allegers' PII in law enforcement recordsEl Confidential Informant or law enforcement information provided by other entityEx. 7(E): ElLaw Enforcement Technique/Procedure used for criminal investigations[--]Technique or procedure used for security or prevention of criminal activityEx. 7(F): [] Information that could aid a terrorist or compromise securityOther/Comments:

t -*

• l Agenda Introduction Presentation of Seismic Reevaluation Report SSHAC Activities Seismic Sources Ground Motion Model and Site Response Discussion of Interim Actions and Evaluations Flexible and Diverse Mitigation Strategies (FLEX) Seismic Analysis (PSA) Path Forward Introduction Energy Northwest followed the approved process for development of seismic hazard reevaluation for the Columbia Generating Station site in response to Enclosure 1 of the NRC's 1 O CFR 50.54(f) Request for Information Screening determination performed in accordance with endorsed Screening, Prioritization, and Implementation Details (SPID) (EPRI 1025287) Energy Northwest will present a detailed technical basis to demonstrate how process was followed and is prepared to discuss each of the technical focus areas

SSHAC Activities

• SSHAC Level 3 (SL3) conducted as "Hanford Site-Wide PSHA" with sponsorship from DOE and Energy Northwest
• Project planned and conducted to comply with NUREG-2117 and other guidance
• Roles and responsibilities of all project participants defined and adhered to
• Project-specific enhancements to SL3 process
• Participatory Peer Review Panel (PPRP) confirmed acceptability of both technical and process aspects of the project Hanford Site-Wide SSHAC Level 3 PSHA Purpose of Study: to develop a technically defensible PSHA that can be used for design and safety evaluations at the Hanford Site, Washington, including Columbia Generating Station PSHA must enjoy high levels of regulatory assurance, as indicated by a SSHAC Level 3 process Must provide outputs that allow use at multiple facility sites within the Hanford Site, including the CGS Outputs must be compatible in format with site response analyses for site-specific facility input motions Compliant with NRC requirements, per 50.54(f) letter, and regulatory guidance Compliant with DOE Order 420.1 B (later 420.1 C) regarding 10-year update and expectations of DNFSB SSHAC Guidelines and Guidance . . ***-.. NUR[(jlCJ:{ -6372 UCRL-ID-122160 Vul.1 Recommendations for Probabilistic Seismic Hazard Analysis: Guidance on Uncertainty and Use of Experts Main Report fur t:_s. :'\Llodt":.r C1unn*il'\1UH 1 .* lh*p:*rtm<*ll tir*:ru.*rgy t:ln'lrk l<<owt"r lni-fllUlt"' Practical Implementation Guidelines for SSHAC Level 3 and 4 Hazard Studies NUREG-2117 SSHAC Implementation Guidelines probabilistic seismic hazards analysis Project Plan for SSHAC Level 3 PSHA Project Plan specifies: Project organization Participant roles and responsibilities Scope Schedule Deliverables and instructions for usage Provided a basis for all project planning and contracting Ongoing information for participants and reviewers Recommended elements given in NUREG-2117 Hanford PSHA Enhancements New data collection activities PPRP participation Interfaces between seismic source characterization (SSC), ground motion characterization (GMC), and site response Selection Criteria for SSHAC Participants Tl Leads Tl Teams PPRP Specialty contractors Resource experts Proponent experts Hazard analysts l<nowledge Technical of PSHA expertise in SSC /GMC Objective & impartial evaluation Experience of SSHAC processes Bommer, J.J. and Coppersmith, K.J., 2013, SMiRT-22, Lessons Learned from Application of the NUREG-2117 Guidelines for SSHAC Level 3 Probabilistic Seismic Hazard Studies for Nuclear Sites Hanford PSHA --------------------------------------. PrOJ
• ect Organization Sponsors DOE-ORP, DOE-RL Dan Knight Energy Northwest Greg Lisle ... , Project Manager .... PPRP Project Quality Engineer Bob Bryce Ken Campbell. Chair Emily Wilson J. Carl Stepp Woody Savage Project Technical Integrator (PTI) Bill Lettis Kevin Coppersmith Brian Chiou I I I Project Technical Resources Hazard Analyst Data Base Manager A. Rohay V. Montaldo Falero D. Ward-Spatial Data C. Ross -Non Spatial Data ' I SSCTI Lead GMCTI Lead Kevin Coppersmith Julian Bommer I Specialty Contractors Specialty Contractors SSCTI Team GMCTITeam Resource Experts H R. Coppersmith L. Al Atik Resource Experts I !including R. Youngs) K. Hanson A. Rodriguez-Marek J. Unruh G. Toro I Proponent Experts L. Wolf R. Youngs Proponent Experts Seismic Source Characterization Team . ti I-. 1-+Kevin Coppersmith -Tl Lead +Lorraine Wolf + Kathryn Hanson +Ryan Coppersmith +Jeff Unruh
• Valentina Montaldo-Falero -Hazard Analyst
• Roseanne Chambers -PSHA document integrator
• Joe Lettrick-GIS data base manager Ground Motion Characterization Team + Julian Bommer -Tl Lead + Bob Youngs + Linda Al Atik + Gabriel Toro + Adrian Rodriguez-Marek Resource and Proponent Experts -WS1 Individual Walt Silva Carl Costantino Norm Abrahamson Tuna Onur Rob Graves Art Frankel Tom Hearns Alan Rohay Tom Pratt Brian Sherrod Rick Blakely George Last Harvey Kelsey Rex Flake Erick Burns Paul Thorne Bruce Bjornstad Pacific Engineering & Analysis Consultant Affiliation University of California, Berkeley Onur Seemann Consulting U.S. Geological Survey U.S. Geological Survey New Mexico State University Pacific Northwest National Laboratory U.S. Geological Survey U.S. Geological Survey U.S. Geological Survey Pacific Northwest National Laboratory Humboldt State University Central Washington University U.S. Geological Survey Pacific Northwest National Laboratory Pacific Northwest National Laboratory Resource and Proponent Experts -WS2 Individual Walt Silva Carl Costantino Norm Abrahamson Art Frankel Alan Rohay Suzette Payne Yousef Bozorgnia Paul Spudich Jennifer Donahue Dave Boore Olga Ktenidou Gail Atkinson Nick Gregor John Zhao AIRohay Tom Pratt Brian Sherrod Rick Blakely Marcia Mclaren Steve Reidel Judy Zachariasen Tyler Ladins Craig Weaver Affiliation Pacific Engineering & Analysis Consultant University of California-Berkeley U.S. Geological Survey Pacific Northwest National Laboratory Idaho National Laboratory University of California-Berkeley U.S. Geological Survey Geosyntec Consultants U.S. Geological Survey ISTerre, Universite Joseph Fourier-CNRS University of Western Ontario Consultant Institute of Geological and Nuclear Sciences, New Zealand Pacific Northwest National Laboratory U.S. Geological Survey U.S. Geological Survey U.S. Geological Survey Pacific Gas and Electric Co. Washington State University URS Corporation, Humboldt State University U.S. Geological Survey Participatory Peer Review Panel (PPRP) + Bill Lettis + Brian Chiou + Woody Savage + Ken Campbell, Chair + Carl Stepp Goal of a SSHAC Process "The fundamental goal of a SSHAC process is to properly carry out and completely document the activities of evaluation and integration, defined as: Evaluation: The consideration of the complete set of data, models, and methods proposed by the larger technical community that are relevant to the hazard analysis. Integration: Representing the center, body, and range of technically defensible interpretations in light of the evaluation process (i.e., informed by the assessment of existing data, models, and methods)." I NUREG-2117 I I NUREG-2117 Table 4-1. Summary of Essential Steps in SSHAC Level 3 and 4 Studies Essential Step Discussion 1. Select SSHAC Level
• Document decision criteria and process 2. Develop Project Plan
• Includes project organization and all technical and process activities 3. Select project
• Includes all management. technical, and peer review participants participants
• Includes compilation of existing. available data 4. Develop project
• Can include focused new data collection database
• Data dissemination to all evaluator experts (Level 4) or Tl Team members (Level 3) Workshop topics: 5. Hold workshops
• Hazard-significant issues and available data (minimum of three)
• Alternative interpretations
• Feedback 6. Develop preliminary
• Preliminary models developed prior to Feedback workshop model(s) and Hazard Input Document (HID)
• HID provides input to hazard calculations Table 4-1. Summary of Essential Steps in SSHAC Level 3 and 4 Studies
• Intermediate calculations should display the impact of elements 7. Perform preliminary of the expert models hazard calculations
• Hazard calculations should show the significance of all elements and sensitivity of the models analyses
• Sensitivity analyses should include the contributions to uncertainties
• Feedback provides a basis for prioritizing and focusing the 8. Finalize models in light finalization process of feedback
• Implement expert combination process across all evaluator experts in SSHAC Level 4 9. Perform final hazard Should be conducted to develop the required deliverables for calculations and
• sensitivity analyses subsequent use of the hazard results 10. Develop draft and
• Fundamental documentation of SSHAC process. technical final project report bases. and results 11. Participatory peer
• Periodic written reviews of key products and activities review of entire
• Review of draft report process
• Final written review of technical evaluations and process used

-m < 0 ::J Preparation of Work Plan Assessment of lr1 Team II PPRP I Preliminary Database)

• Hazard Significant ... Issues -------Resource 1: Hazard Significant _ Experts ,,_ Issues and Available Data ti111,1----t Resource Experts rl Additional Data Collection & Analysis I+-n Al :;o 't:I l'D -c: ., l'D l'D ,... ::T 0 (!) -0 .... Ill < :i -'11111 r; ID ;"' Workshop 2: Review of Database ..---g3 ""Cl Proponent .___--',M Discussion of Alternative Models o. o I I Tl Team Working Meetings (WM)
• WM1 Experts ...111 I <,_____ WM2 Databasel '11111 1 __________ _ -----------------------,, --------------. I Preliminary SSC and < ....... ..... -I + (!) -----------ID Preliminary HID :i ui 0 !2. . I -< Hazard Calculations and Sensitivity Analysis 0 WM3 (!) ... ii) Workshop 3: Feedback to Tl Teams ... on Preliminary Models .... :::a::::::::I .... :i I I Final SSC and GMC Models 1,,.-.__ __ ...... ro a. -----------WM4 0 ------------------------+----------Final HID and Hazard Calculations 0 ... 0 0 I Draft of Final PSHA Report c: 3 ... 11) ::i Review and Finalize PSHA Report -Ill -* s* :i I PPRP Closure Letter w c: *-----1 e. 3 0 ID ::J ::J *---UI ii L I -I -I., -I ,. I 4 days duration All team members Conference room with GIS support PPRP observers Requirements for SSHAC Level 3 PPRP PPRP Roles and Responsibilities Technical review: ensure that the full range of data, models, and methods have been duly considered in the assessment and all technical decisions are adequately justified and documented Process review: ensure that the project conforms to the requirements of the selected SSHAC level Provide timely perspectives and advice regarding the manner in which ongoing activities can be improved or carried out more effectively Be present at all the formal workshops as observers and subsequently submit a consensus report containing comments, questions, and suggestions Provide one or more representatives of the PPRP to attend as observers the working meetings of the Tl Teams Perform detailed review of all project documentation and provide written comments to ensure complete technical justification of integrated distribution Prepare PPRP Closure Letter providing final technical and process review I I Preparation of Work Plan Hanford PPRP lr1 Team II PPRP I Assessment of Major Activities Hazard Significant -, Database) Issues 0
• n Ill Workshop 1: Hazard Significant Ill :;o Review of Project Plan and -Resource "'C l'D Ill --s. C" Experts ... Issues and Available Data " c: attendance at Kick-Off m Ill ., l'D Ill l'D < l'D -0 ... , Additional Data Collection & Analysis I+-::r 0 c: (I) -Ill l'D en < n l'D {WM1} Ill en Full PPRP present at all 3 0 0 Resource :i :I: = -J> "'C ,,, l'D 3 Experts -;"' n Workshops l'D , Workshop 2: Review of Database 1...-OJ ""Cl = Proponent 0 ., .... , Discussion of Alternative Models 0 Q. t"> Experts (!) Ill PPRP representative as Ill _Ill Final Database I = Q. observers at all 8 Working :;o Ill n -----------------------------------= --. ::r Meetings IC = Preliminary SSC and tD n 0 GMC Models -OJ , -I + II) Ill (") I/I PPRP encouraged to ::r l'D Preliminary HID ::J (/I :l" 0 0 interrogate Tl Teams on -... Ill J> <O I -< I/I their preliminary models at ., Hazard Calculations and Sensitivity Analysis Ill 0 I/I .... l'D c;* ... l'D I/I WS3 -I/I = l'D 3 Workshop 3: Feedback to Tl Teams j :I -l'D on Preliminary Models = !l: -l'D I/I y ..._WMij Ill PPRP Briefing to review ::J I -Q. Final SSC and GMC Models l'D , * ., 9 Final SSC and GMC models ------------------------+------"'C ... " c: Final HID and Hazard Calculations I>> 3 e. 0
• 0 l'D ::J ::J Review of Draft Report 0 Ill -n I Draft of Final PSHA Report I -II.I -c: c;* 3 * ::i Review and Finalize PSHA Report I J -Di I., ---. c;*
• Preparation of PPRP ::J I I ,. PPRP Closure Letter I Closure Letter -----

PPRP Closure Letter November 15, 2014 The Tl Teams were responsive to the questions, comments. and suggestions made by the PPRP relative to the technical aspects of the project. Therefore, the Panel concludes that the technical aspects of the projects have been adequately addressed. Conclusion On the basis of the PPRP's review of the HSW PSHA, the Panel concludes that both the process and technical aspects of the assessment fully meet accepted guidance and current expectations for a SSHAC Level 3 study. We appreciate the opportunity to provide our review of the project. Sincerely. HSW PSHA PPRP Members 1,.; . G..""f Kenneth W. Campbell Chair 1 I ' . ),1 (* -. '-William U. Savage HSW PSHA PPRP Closure Letter Brian S.-J. Chiou r/Cdl:ifar J. Carl Stepp William R. Lettis Page 5

2 5 5 tO -Hanford Site-Wide SSHAC Level 3 PSHA 15 465!>4548 LM9 *119517907) B -We$! Area 1La1 .:6 Loo;; -11(1 &250631 C -Co'""'D*a Stat on (lat 47 It 88 lor.9 -19 )34 I 70i D. tC06Ct.rea .:(j(iJ0376 Long .119647486> E. 3:0A*Ci'l 1Li\1 46 3&8604. Long -119 :;>'7461 I SSC-Related Activities Compilation of extensive geologic/geophysical/tectonic database Update and analysis of earthquake catalogs: crustal and subduction zone Identification of seismic source zones and future earthquake characteristics Structural geologic and Quaternary analyses of Yakima folds Assessments of behavioral characteristics of fault sources including segmentation and slip rates Incorporation of associated uncertainties, including both aleatory and epistemic components Seismic Sources in SSC Model Cascadia Subduction Zone sources Plate interface lntraslab source Seismic source zones YFTB zone: serves as a "background" zone to fault sources Zones B, C, and D Fault sources within Yakima Fold and Thrust Belt (YFTB) 19 faults characterized More distant faults are implicitly included in source zones New Data Collection and Analyses Focused studies and analyses designed to reduce uncertainties in key SSC and GMC issues, within the project schedule and budget GMC-related Velocities at recording sites Analyses of kappa Analyses of basin effects SSC-related Structural analyses of Yakima folds Quaternary geologic studies High-resolution earthquake relocation analyses Seismic Source Characterization, Focus Area 1 1. Summarize the information used to constrain the slip rates on the YFTB faults, including: a. Methodology used to evaluate fault slip from topography including associated uncertainties in the ages and offsets. c. How potential effects of surficial erosion were accounted for in the use of an average topographic profile to represent structural relief in individual faults. Pertains to these sections of the report Section 5.2.1 Structural Analyses Section 8.4.3 Fault Characteristics Included in the SSC Model Appendix E, Section 5 Evaluation of Long-Term Structural Relief Steps in Characterizing Fault Sources Measure topographic relief along lengths Define segments for use in estimating Mchar, Mmax Alternative rupture length, area relationships Identify polygons on DEM defining fault-related deformation within seismogenic crust Compare topo relief with structural relief from boreholes: Agree. Define fault dip and uncertainties, given mapped fault location, seismogenic thickness, and polygon Max, average, 60°/o of polygon width defines uncertainty in fault dip and downdip width for given thickness Include geologic indicators of style of faulting to derive net slip Alternative start times of deformation 1 Omy, 6my for slip rate Compare with Quaternary rates where known: Agree. Steps in Characterizing Fault Sources (continued) Magnitude frequency distribution model Compare with fault-related seismicity: Characteristic earthquake model supported Incorporate recurrence interval data, if available Renewal model: elapsed times and alpha unknown Future ruptures: magnitude-dependent rupture areas, lengths can extend across segment boundaries Topographic Analysis of Folds: Defines surface evidence of fault-related deformation within seismogenic crust I.* .. 'It . Ma:Jntcii:i Q 4.[00 3 ooo Ooll

• 4.GOO is.coo :':'Dm norn lml 10 (* K:lomt:crs ---f:C ! " a ;x . ... ---------* <.vV e Horse Heaven Hills Base level Di\tanc* lml 400 m Identification of Polygons & Possible Segmentation Points ... ._:.... -.. '.,;;. 30 .' ./ J(:(J.) f:<,c:-::* *i ! . "'*Jl' . 2 'ii t**.:1,.1 )(:*J .', Yakima Ridge West-Yakima Ridge East ;:.;(:(I(.(} Ditt*n<* (m) Umtanum Ridge-Gable Mountain l*IJ(1'.X,\ 0.*tance 3C t*JL".t':Xl .. . I *-' .... ,' . . . * :*. j : : ,ir** ... : .; ........ ' ./. -.. , **_,,r., * .AJP;:* *.**.' .. *-!* "i.*".-. i* -.. *I.. 15 0 30 K1lomt"terr.i:'T"< J .

Comparison of Topographic Relief with Structural Relief --.. *4$"0*N .. 0 ..... , ... ...._iio o 0 * ."" '* , .. 0 *.*

• i;.f-; *u . 0 0 r. **-. -** ,*. .. QI 0 * . .. *._ 0 .. .. 0 .,.., (I ----119'"30'0'W ......... : ........ , ... '.*.'""I Pralile 2 111*30'0.,,.,.
• 0 . . a a o . .. 11.*(l Saddle Mountain Profile 1 :. l/t;'t.... _! __ -! :i_...-/ ---I>-* ------_-_-_:------* Saddle Mountain Profile 2 " -D*--IC\ll' ' 1.>\'lo)'o Legend 0 GPS :,,.'3 -AS!i. .. r;* .1pp:r CRB Mean Structural Relief *Shape of segments and slip distribution is likely the result of repeated rupture
• Average is appropriate for assessing slip rate when have multiple measurements along a fault segment Fault Source I Ahtanum Ridge Cleman Mountain Columbia Hills-Central-East Columbia Hills-East Columbia Hills-West Columbia Hills-Central Columbia Hills-Central-West Frenchman Hills-East Frenchman Hills-West Horn Rapids Fault Horse Heaven Hills-Central Horse Heaven Hills-Central-East Horse Heaven Hills-Central-West Horse Heaven Hills-East Horse Heaven Hills-West Manastash Ridge-Central Manastash Ridge-East Manastash Ridgt:-West Rattles Rattlesnnke Hills Rattlesnake Mountain Saddle Mountains-East Saddle Mountains-West Selah Butte Toppenish Ridge-East Toppenish Ridge-West Umtanum Ridge-Central Umtanum Ridge-East Umtanum Ridge-Southeast Anticline Umtanum Ridge-West Umtanum-Gablc Mountain Wallula Fault Yakima Ridge-East Yakima Ridge-West Yakima Ridge-Southeast Fault Arronym I Meau Structural Relief (m) AR 330 CM 650 CH-C-E 55 CH-E 105 CH-W 375 CH-C 135 CH-C-W 230 FH-E 155 FH-W 155 HR 90 HHH-C 485 HHH-C-E 415 HHH-C-W 575 HHH-E 205 HHH-W 270 MR-C 300 MR-E 145 MR-W 415 RAW 130 RH 335 RM 619 SM-E 320 SM-W 335 SB 460 TR-E 300 TR-W 310 UR-C 360 UR-E 250 UR-SA 90 UR-W 400 U-GM 160 WF 250 YR-E 325 YR-W 250 YR-SE 65 Uncertainty in Dip Included in Logic Trees : Saddle Mountain topographic width= km 800 700 600 & 400 "G : .300 :!! -200 100 0 0 i Dip at 13 km= 52" I Dip at 16 km= sr ; Dip at 20 km= 63" 1000 4000 6000 8000 10000 13 km 16 km 20 km oo HOOO 20000 nooo 26000 Topographic Analysis of Rattlesnake Mountain -60% of average topo width= 13,200 m -Average topo width= 22,000 m _______ _.-Max topowidth = 34,000 m 13km--20km--------* -----*. ---------;******* *'*< Dip range for 16 km depth 2s* to so*

Logic Tree Elements Related to Slip Rate SEISMOGENIC THICKNESS 13 Km [0.)) lb Km {O. '>) JO Km [0.3J .,., . <;ource specifi( BASIS FOR FAULT DIP M.1x Polygon Width [O.JI l\vt* Polygon Wicilh [O.'"il l..>0% of Aver c1g<> [CUJ FAULT SEGMENT 111111-LlSI rn111 u*n1r.111.1.-,1 Llmt.11H111l (i.lblt' Mtn Um!.ll\lllll ( enlr .11 * *

• SEISMOGENIC PROBABILITY Not \t>i'>rno <'nic [wt '>'>) '>l'i'>mog<>nic (WI'>'>) STYLE OF FAULTING Ht*Vt'I')(' {wt '>'>) Obliquc> (wt '>'>I \tr i kt> <,lip I wt s'>I
• FACTOR FOR NET SLIP l.O [Ul) 1.4 It 01 ),} I0-'11 10.*)1 START TIME 6My [wt '>'>] tOMy lwt .,., I NET SllP RATE Rc1t<* X I wt '>'>I R.1h* Y [wt s<.J * *
• R.lll' n Logic Tree for Rattlesnake Mtn Fault Source FACTOR FOR APPROACH QUATERNARY NET SLIP TO SLIP RATE RATE START TIME NET SLIP RATE 0.0 [O 101081 1.0
• 0.041<J R.Ht* X 11.01 [O J4'1)(JI !wt I <ll1.1t<>rn.uy D.11.1 0.CW)/ R.1tt> Y (0.11 [O. W9l<*J [wt I
• 1.4 10 /4419) * * [t.O) * [010108) R,l!(* n ) ) bM [O.'>>) 10.11 u<t ur .11 Rl'lit*f (O '*.1 to My [O '>) (O .3]

..... 8 Net Slip Rate Distributions 0.8 O.b 0.4 (J.) () i.001 m Yakima Ridge ' . ' ,I :1 1.001 ()} 1.00I 01 Slip Rate (mm/yr) 1.001 *00 --YR\I --YRI --YRW Rattlesnake Mountain 0.8 0. {, ..... e 0.4 0) 0 1.<XH Ol 1.00[ ()) 1.001 01 1.00! *00 Slip Rate (mm/yr) --HM --( ompo<. ih' Seismic Source Characterization, Focus Area 1 1. Summarize the information used to constrain the slip rates on the YFTB faults, including: b. Rationale for excluding thin skinned seismo-tectonic models. d. Bases for excluding listric fault geometries or potential for backthrust structures in structural relief model. Pertains to these sections of the report Section 4.1 Tectonic Setting Section 4.4.1.2 Instrumental Seismicity Section 6.3 Epicentral Locations Section 8.4.3.4 Fault Dip Appendix E, Section 6 Kinematic Analyses Using Earthquake Focal Mechanisms Thin-skinned vs. Thick-skinned Thin-skinned model called for mechanical decoupling of faults within Columbia River Basalts with those in crystalline basement Former proponents for those models participated in WS1 and WS2 and have abandoned that model Multiple arguments for discounting thin-skinned model are given in pp. 4.5 to 4.1 O Additional support was provided by high-resolution earthquake locations, which show no lack of seismicity at sub-basalt sediments Focal mechanisms in CRB and crystalline basement show comparable styles of faulting and stress orientations Geophysical properties of sub-basalt sediments suggest that they are not mechanically "weak" Listric Fault Geometries Listric geometries were not explicitly "excluded" A planar fault is the simplest geometry and is consistent with the back-limb geometry of essentially all of the YFB folds Historical large-magnitude thrust earthquakes show essentially planar rupture surfaces Backthrusts would have been included if there was good mapped evidence for their presence, and that they extend to the base of the seismogenic crust (i.e., are not confined to shallow depths in the hanging wall of another fault)

GMC Approach Use appropriate GMPEs to develop distribution of predicted ground motions Select and appropriate GMPE shape to use as a backbone model Develop distribution of scaling factors to adjust the backbone to represent the distribution of predicted motions Develop scaling factors to adjust for unique site conditions at Hanford Hanford Profile Several 100 feet of sands and gravels, some with cementation Sequence of basalt flows with well defined and relatively thick sedimentary interbeds -Saddle Mtns Basalts and Ellensburg Formation interbeds Several km of more massive basalts, Wanapum and Grand Ronde Several km of sedimentary rocks above crystalline basement rocks o_ 100 200 300 400 500 t-600 UJ LU LL 700 I I-0. LU 800 Cl 900 1000 1100 1200 1300 1400 1500 _ I . t: RINGOLD FORM&.TION 130' 250' f I/) z z :J 0 ::2: w _J 0 0 <( U) A\ 0 Selection of Reference Horizon for Site-wide Study Initial concept to use top of SMB/lnterbed sequence However, site response analyses indicate that treatment of the SMB/lnterbed sequence as a halfspace produced different surface motions than obtained from explicitly modeling basalts and interbeds Reference horizon moved down to top of massive Wanapum basalts (top of Lolo flow with flowtop removed) Implications for Downstream Site Response Analyses Assessment of baserock properties required assessment of properties of overlying SMB/lnterbeds In order to maintain consistency in downstream use of baserock hazard, properties of SMB/lnterbeds specified for use in site response based on properties used to develop GMC Uncertainties in damping within SMB/lnterbeds incorporated into uncertainty in baserock hazard in order to minimize computation burden for subsequent analyses. Crustal Earthquakes GMPEs Primary sources of hazard from shallow crustal earthquakes are reverse and reverse-oblique faulting mechanisms for sites that may be located in the hanging wall Selected candidate models that best represent these types of earthquakes -NGAW2 models, particularly those that explicitly include HW effects Select one of the candidate models to use as the backbone Compute distribution of ground motion predictions from candidate models relative to the selected backbone model Develop distribution of scaling factors to center the backbone model and represent the distribution of ground motion predictions First develop footwall model using ASK14, BSSA14, CB14, and CY14 GMPEs Compute predicted ground motions for a range of magnitudes, distances, fault dips, and depths to top of rupture Compute residuals for all of the predictions as residual = ln(PSA)_i -E[ln(PSA) for 4 NGAW2] for all 4 NGAW2 models Represent epistemic uncertainty in adjustment from CY14 by a mixed effects model L1 ln(Y) = clF + C2F {M -6.5} + clR,f(M) + C2R {M -6.5} Fixed coefficients represent change from CY14 to average of selected 4 NGA West2 GMPEs Random coefficients represent variability in scale factors from individual GMPEs to average Represent Distribution of Scale Factors Discretely Use period independent scale factors for T <= 2 seconds Scale factors nearly period independent for periods that contribute to hazard Allows use of a common Vs-kappa correction Use 9-point approximation of 2-D Gaussian distribution Account for correlation between random scale factor and random adjustment to magnitude scaling Resulting Footwall Models "' 0 0 c:i MS.5 ,Rx-5 km Centr .. 1 8eickbone --Epistemic MoaP.ls SL_ _______ __J ........ .u...J.L_.._1-..1_,_,..., 0 "' c:i § M7, Rx -5 km c:i -Centr .. l 8eickbone --Epistemic Models om 0.1 o.3 10 O.o1 Period (s) M6, fl'y -5 km Centr<1l 8ackbone --Epistemic MoaP.ls M 7 5 ,Rx -5 km -Centr<1l 8ackbone --Epistemic Models 0.03 0.1 0.3 Period (s) 3 W0.01 M6.5,Rx-5 km Centreil 8ackbone --Epistemic Moaels M 8, Rx -5 km -Centreil Backbone --Epistemic Models 0.03 0.1 0.3 Period (s) 3 10 Develop Hanging Wall Adjustments Use ASK14, CB14, and CY14 HW factors Compute average scale factor for RJ8 = 0 sites as difference between mean HW factor [in lnPSA)] and CY14 HW factor Model HW adjustments with function form HWadJustment = [1+ p4 cos(O)]xln[p5 cosh{p6 max(ln(Rx I p7),0}] Compute coefficients for mean adjustment and sigma of adjustments Add the mean adjustment to the mean FW adjustment RSS the HW sigma and the sigma of fitting the mean adjustment in with the FW random C1 component Crustal GMPE Logic Tree Backbone GMPE CY14 ( 1.0) Vs-K Adjustment Factors V K-7 s (0.(155) V K-6 s (0.136) V K-5 s (0.198) V K-4 s (0.222} V K-3 s {0.198) V K-2 s (0.136) V K-1 s (0.055) Inherent Uncertainty in Backbone Adjustments [llln(Y) I M]9 (0.0625 I [llln(Y) I M}8 (0.0625) [llln(Y) I Mb (O.fi625) [llln(Y) I M]6 [81n(Y)IM]5 (0.50) (llln(Y) I M]4 (U.Ot:i2:,) (llln(Y) I Mb (0.0625) [81n(Y) I M]2 (0.0625) [llln(Y} I M]1 (0.0625) Host-to-Target Uncertainty Factors 1.3 jll.3 J 1.0 (0.6) 0.8 (0.1) Subduction Zone GMPE Selected backbone model BC Hydro model (Abrahamson et al., 2014) Developed as part of a SSHAC Level 3 study as a response to shortcomings of existing relationship Global dataset Includes epistemic uncertainty in magnitude scaling Includes forearc/backarc scaling Modifications to BC Hydro GMPE to Address Ground Motions at Large Distances Modify dataset Re-evaluate censoring of data Additional data (KiKnet, Arango et al. for Central America, Maule EQ) Remove Taiwan data for sites where forearc/backarc is unknown Use Arango et al. data for El Salvador Earthquake Exclude Tohoku mainshock and aftershocks Attenuation rate at high frequencies is high -low motions at large distances Still used to constrain epistemic uncertainty in large-magnitude scaling Modifications to BC Hydro GMPE (2 of 2) Modify functional form controlling anelastic attenuation Assess modified model coefficients applying higher weight to data at distances > 200 km Include forearc/backarc scaling uncertainty Nisqually earthquake data from Hanford site consistent with BC Hydro backarc attenuation predictions Regions other than Japan do not show clear difference in forearc/back arc, but data is often limited Numerical simulation based model of Atkinson and Macias (2009) derived using a Q model similar to that of Phillips et al (2014) for the Cascadia-Hanford travel path show low attenuation similar to BC Hydro Forearc model Subduction Zone GMPE Logic Tree Sackbone GMPE Back-arc () *. O} Scaling [.&Cl] med+ 0.2 (0.2) [8C1]med (0.6.J med -0.2 (0.2) Scaling on Anelasttc Atten uatlon Term 0.5 06 ( 0.4) Ss ( 0.6) Epistemic Uncertainty in Median x1.62 (0.2) x1.0 ( 0.6) x0.62 ( 0.2) Host-to-Target Vr:. Adjustment Factor* Vs factor-4 (0.335) Vs factor-3 (0.165} factor-2 (0.335} Vs factor-1 (0.165) Adjustments to Hanford Baserock Conditions For Crustal GMPE adjust for Vs and kappa For Subduction zone GMPE adjust for Vs only Vs and Vs-kappa adjustments made using the Inverse Random Vibration Theory Approach of Al Atik et al. (2013) GMC, Focus Area 2a: Provide additional detail on the Vs-Kappa corrections applied to the scaled backbone GMPEs -Rational for not applying a kappa correction for the subduction zone GMMs Hazard sensitivity analyses indicated that the distant, large magnitude Cascadia subduction zone interface (CSZ) earthquakes primarily contribute to the hazard at low frequencies where the effects of kappa are small Because of the large distance to the CSZ (>200 km), the effects of Q are expected to dominate over the effects of kappa. Therefore, incorporation of uncertainty in Q was the focus Because the subduction zone GMMs are defined primarily by data at large distances, separation of kappa effects from Q effects in the host GMMs is difficult. GMC, Focus Area 1 (1of10) Provide additional detail on the process used to define the target site kappa values and their uncertainties, including the rationale for logic tree wefahtinas. Utilize recordings of small earthquakes from 6 sites located on basalt or a few meters of soil over basalt to assess kappa for basalts Some sites located on SMB with interbeds, some on outcropping layers of deeper basalts Apply alternative approaches to estimate site kappa and its uncertainty Inversion of Fourier spectra of recordings Anderson and Hough (1984) Apply kappa estimates in forward sense considering uncertainty in contribution of deeper sediments to kappa for large earthquakes GMC, Focus Area 1 (2 of 10): Target site kappa Target kappa logic tree 1.11\:d *. Uncertainty in Vs : .II:.'.'!{ !>11 *!ii-: .\p1*n* .. 1 ... i1 h* I* ,11::1.11-: : 1,\ :1hi:;-.\J1p:l'.ld1 1-'a*!ilt" I *:k profile l. : . 1.11:11: Alternative ' , . '1 I approaches Uncertainty in Pr.*:'::c I ir1h*r':*ll1\ *:. All '>:ti estimates from each . '* . approach '-:. l . . . Uncertainty in depth . : range contributing to .. 1 h-kappa for larger Pr* I:;: earthquakes ... ,,,,, J ,t....:, h. '.l.'h '*' s.-,! I I -.s : I *:.-i '_*' GMC, Focus Area 1 (3 of 10): Target site kappa Alternative Vs Profiles Differ in SMB Vs Differ in subbasalt sediment Vs Favor Profile 1 2:1 over ! j E -Profile 2 -prefer downhole Vs measurements over ._ suspension logging in basalt Difference in subbasalt Vs had small impact on assessments V!. (km/sec) j ' -{ \ I \_j :,.1 --:.-: (. :

• L)* l l 1 -' ! -E .J:. <. Q. -c. 0 : ::* J\.:. ----*-15 !. (km/sec) I j \ ---*----I \ I I \ . . I \ . *--* --(. !. . . . ! l*!.

GMC, Focus Area 1 (4 of 10): Target site kappa kappa estimated by inversion Used recordings from 15 earthquakes recorded in 2005 to 2013; 10 recordings at HAWA from 2004 study Hypocenter depths 5 km to avoid double paths accelerograph recordings at HAWA; all other recordings were on BB velocity instruments Inversion process estimates kappa along with source (fc) and path ( Q) parameters by nonlinear least-squares fit to FAS using source model was fixed at due to limited distance range and limited bandwidth Determined parameters: fc, kappa GMC, Focus Area 1 (5 of 10): Target site kappa Assessed correlation of kappa assessed from inversion with: Thickness of SMB Total thickness of interbeds Thickness of subbasalt sediments Conclusion that entire profile above basement contributed to kappa from the small, deeper earthquakes * * * . ' . (> . ' . .-.. : .... *.*; *.. * *. ... * ... *'-' . .. . ' *\ 0.

• t. ' . lit .. .'* ., .... TIX.ti Thld.n.;*u of F:lv1>*.bu1g rorm.ttloti lnt*rt>.d-. ( m) * *. ,,,:. *. \* .* r, . **h . I; . . .... -1 * * . 0. 0. ... : 1-.
• I . ' ., . I * * * * '. ' .*.I
• 0 0 * * * * :.* .. f* -*. ****** * :n::
• 0 * *
• GMC, Focus Area 1 (6 of 10): Target site kappa Anderson and Hough (1984) approach: Select data for R < 200 km that show linear trend in FAS at high frequencies Select frequency window for linear trend Smooth FAS and noise with Konno and Omachi (1998) filter Select records with signal to noise ratio > 3 Estimate kappa by fitting a( Extrapolate trend with distance back to 0 distance 0.1 . O.O'J . 0.08 : ()<JI * (l()I,. O.<H -0.(l/.; ()Ol . (). tl ; 10' ! 10 0 y 11 !*' * (I (.l.1.1*.* I) 71:11*1 !1: :l.i i'*' -JI) -'. Vector Sum : : -k0.049014 . 50 100 Frequency (Hz) ---.. (>l> 80 JI.JO R(kmJ 1\11'1 ( nn c nrt 'l'Nl \!T1* c nr: HAI r1 t GMC, Focus Area 1 (7 of 10): Target site kappa Assess site kappa removing effects of shallow soils and scattering from SMB interbeds Soil kappa assessed using Campbell (2009) Scattering kappa assessed by comparing response of an equivalent uniform Vs profile with damping to layered profile without damping Assuming Qs = yVs develop estimates of y to assign kappa to SMB and to deeper layers Based on K = H/Vs/Q GMC, Focus Area 1 (8 of 10): Target site kappa Favored inversion over A&H 2:1 Based on fit of broader frequency range of FAS A&H produced variable assessments of Os Application of A&H method required use of shallow earthquakes with potential multiple paths Epistemic uncertainty in A&H kappa assessed based on statistics of fit Epistemic uncertainty in Inversion kappa based on assessments of parametric variations in inversion parameters Produced an asymmetric distribution In addition, best estimate kappa based on Q(f) larger than Phillips et al. (2014), thus may be biased high. Weights adjusted to account for potential bias (lower Q would lead to lower kappa)

GMC, Focus Area 1 (9 of 10): Target site kappa Final component -depth extent of subbasalt sediment contribution Results for small, deep earthquakes indicates all of sediments No data available to assess contribution for shallower earthquakes or large earthquakes Considered three equally weighted alternatives All, half, or none GMC, Focus Area 1 (10 of 10): Target site kappa Resulting baserock kappa distribution Site C 0.2 -0.15 *-(!) 0.1 0.05 0 Kappa Bin GMC, Focus Area 2b: Provide additional detail on the Vs-Kappa corrections applied to the scaled backbone GMPEs -Comparison of the Vs-kappa scaled median GMPEs and NGA-West 2 models M 7, Rrup 11 km, HW 0 0 LO Red curve -Median Crustal g for V530 760 Black curves -Median Crustal scaled by Vs-kappa corrections <!'. (/) Cl. ...... 0 LO ci 0 ,.... 0 LO 0 ci ,.... 0 0 ..........,..__ ___________ ___. 0.01 0.05 0.10 0.50 1.00 5.00 10.00 GMC, Focus Area 2c: Provide additional detail on the Vs-Kappa corrections applied to the scaled backbone GMPEs -Whether any observational data from the region was used to assess the Vs-kappa corrected GMPEs Available ground motion data from small crustal earthquakes in the region recorded on basalts or shallow soil over basalt were used to assess kappa Recorded crustal earthquake data is generally from earthquakes too small to make meaningful comparisons with the developed GMPEs Data from the M 6.8 Nisqually earthquake was used to assess attenuation from distant CSZ earthquakes Aleatory Variability Model Utilized single station sigma concept Development very similar to that of the SWUS model with similar results Specified minimum level of epistemic uncertainty in characterizing site response to address: Lack of variability in site response at very low frequencies Possible basin effects in surficial sediments at intermediate periods GMC, Focus Area 3: (1of5) Provide additional discussion regarding bases for bump seen at T 0.1sec in the mean tau values for the NGA-West2 models and the decision for smoothing through this peak in developing single-station . sigma. A peak in the event-to-event variability (r) is commonly seen in the results of analyses of empirical strong motion data r is a measure of the differences in the average motions from earthquake to earthquake May be due to source differences May be due to differences in average site conditions for each earthquake Possible mechanisms for peak explored Using point-source stochastic simulations Examination of data from limited geographical regions GMC, Focus Area 3: (2 of 5) Bump in rat T o. 1 sec. Performed point-source stochastic model simulations Random variation in stress parameter (stress drop) Random variation in site K Simulated motions 200 earthquakes with lognormally distributed stress drops For each earthquake, ground motions at 25 sites with lognormally distributed site K Fit results with mixed effects model to compute variance components r and cf> Two cases analyzed No correlation in site K between earthquakes --produces a peak in cf> (within event variability) but not in r Half of the variance is assigned to event-to event variability in median K and remaining to within-event site-to-site variability in K--produces a peak in both r and cf> GMC, Focus Area 3: (3 of 5) Bump in rat T 0.1sec. ..... 0 Results of fitting mixed effects model to simulations I .,.._ ' ' ' ' ' .... ..... No kappa correlation with EQs Tau Phi Total. RE Fit ..... ..... ..... .... ... ---a> 0 co 0 E '1) 0 II) ---I .... -..... .... ... --.... .... ...... .... .... -... ..... ------kappa correlation with EQs Tau Phi Total. RE Fit -, ... .... ... ... ... ---'<r. 0 ----------------------*:t 0 ---.... ---.... .... --------------"' 0 N 0 0 I 0.01 0.03 0.1 0.3 Period (sec) --...... ...... ' ' ' ' ' ' 10 N 0 0 0.01 O.O:J 0 1 --0.3 Period (sec) ---...... ' ' ' 3 ' ' ' 10 GMC, Focus Area 3: (4 of 5) Bump in rat T 0.1sec. Fits to CY14 'i"' M <. i::::; *I I I II f residuals for IJ.J * :11h :d I R111Ju1 1 [fi:1..: ,......

• Jo:I* :a 1 .:me ::tat en Rane cm [ffe::: only California ...., data (I ... Inclusion of site-" "' to-site variability l-4 " term shifts peak I ' I II 11 l at 10 Hz from r ol I I I I I ii II I ) (1 [ )3 O.' 03 3 10 to ¢525 for Pe1ioJ (5) M < 5.5 N
• 1 II" I Less conclusive r.u * :11h :d I R111Ju1 1 [fi:1..: "
• Jo:I* anc Jtcit en Ranccm [ffe::: for larger M, but ...., limited data (I ... from sites .... " recording multiple l '4 ,, " earthquakes ol I I I I I i( II I I I I I I 11 I ) (1 ()3 O.' 0.3 3 10 Pe1iod (5) -JI ..... , 11111111 -1 11111-1 , 1 *111**i* w n ... w n * ... n
• 4roul * ,, h, 0 CO' JC: I II II I r
• 1 ", 1 I J I I I II 0.1 C3 3 1( * * , , 11111
• 1 , 1 .. , ., , 1 -1 "-11 M I I n 0 CO' I I I II I II I 0.1 I I I II I I I l I I I II C.3 3 1(

GMC, Focus Area 3: (5 of 5) Bump in rat T o. 1 sec. Conclusion -peak in r near 10 Hz (0.1 s) likely due to differences in average site conditions from earthquake to earthquake rather than variability in earthquake source properties Uncertainty in site effects for Hanford sites is explicitly addressed in development of GMC model Therefore, peak in r is smoothed through in developing aleatory variability model Provided Recommended Vertical/Horizontal Spectral Ratios for Development of Surface Vertical Spectra 1.5 -GA2011 Gulerce and Abrahamson (2011) modified at long periods to match trends in data from the Maule earthquake .. -.. -GA2011 modified en ..... (.) 1 <l> (/) c 0 N *c 0 I I 0.5 .9 ...!.. ro (.) *-t (I) > 0 0.01 0 1 1 Oscillator Period (seconds) I / I / I 10 Baserock Hazard Results at Site C -CGS SiteC 10°-------10, r ............ . ... *-* -....... __ . ** *-*-* ---* **-*-* -...... _..1 ..... --*---10" 10' 101 1011 Peak Ground Acceleration [g) 5th ---16th 50th ...... ********* 84th 95tt1 -meanTOT. GI u 10" i 10' "ti GI GJ 101, w 0 10* c . GI ::I er 10 LL. "' 10" c < 10 SiteC 10* 10'.I 10' 10 I io*' 101 T1 .OOsec Spectral Acceleration (g) 5th SOlh -841h 951h -meanTOT, Source Contributions QI CJ c "' "Cl Cl.I QI CJ )( w -0 SiteC 10° 10 10 10 10 'r 10 10"' 10*1 io*2 10* 10° 101 Peak Ground Acceleration [g] ZONES --FLTS --csz --JDF -TOT 10" QI CJ c 10 "' "Cl OJ Cl.I CJ 10 :1; )( w -0 SiteC 10 4 10*1 10*2 10*' 10° T1 .OOsec Spectral Acceleration [g) 10 ZONES I --FLTS --csz --JDF -TOT Contributions to Uncertainty (1 of 2) Site C (CGS) -Peak Ground Acceleration 100% -8 90% c D 10-3 AFE *10-4 AFE .9 80% ... Cl > 70% o 10-5 AFE

• 10-6 AFE 0 60% CJ 10-7 AFE c 50% G> u Ir> 40% CL 30% 20% 10% 0% -J -.Al 0 */ ... , ... ': ... . ,. *:* \ .... .<* * * ,. ...... ,:.

Contributions to Uncertainty (2 of 2) ! i "C > -I -0 Site C (CGS) -T 1.0 sec SA 100% o 10-3 AFE 90% *10-4 AFE 80% o 10-5 AFE i------lO%

• 10-6 AFE a 10-7 AFE 60% 50% :. 40% 30% 20% 10% 0% ...... L......p!L&L.+ 0 */ ... , ... ': ... . ,. *:* \ .... .<* * * ,. ...... ,:.

Development of Input Motions for Site Response Deaggregated mean hazard at each frequency Developed 4 scenarios to represent deaggregation M, Rand weight of event . vanes Developed conditional mean spectrum for each scenario 101 CMS 10° i 0-. 10 / . ' 0 ;f. "' 10 l Frequency [Hz I 1.0 Hz, AEF: l .Oe-04 -UHR!'> -*.1 '>.6, R: 7 krn, Wt: 0.1'.> '.I R 11 km. Wt: 0 39 '.I . l.l, R: 20 krn, Wt. ->./

• 9.0, R: 3.16 km, Wt* 0.21

Site Profile Site profile consists of two zones: Upper sands and gravels (525 ft thick) Sequence of basalt flows (765 ft thick) to top of Lolo Flow Sand and gravel properties based on FSAR data Basalt flows characterized in PSHA study Simulated profiles generated for each zone and then joined 2 i-w LU LL J: i-a. LU 0 0 100 200 300 400-500 600 700 800 900 1000 1100 1200 1300 1400 1500 t: 1-RINGOLD FORMATION 130' 250' f III (/J z z ::J 0 w ....I 0 0 ;:3 1345' nv RON !;: (/J<( INTERBEO 5* Z nso* <( Labeled depths not for CGS 0 Upper Sands and Gravels Profile Velocities obtained by hole and down-hole measurements at CGS (formerly WNP-2) and nearby WNP-1 and WNP-4 Considered: one velocity profile with cr1n 0.15to0.30 EPRI and Peninsular Range (PR) nonlinear curves (D s 15°/o) GSU 440ft .,H T-: 350 .__.___ ___ 250 g c: 150 .. > ..!! ... 50 *50 -150 I Middle Ringold I :, :, :. :.. '1 -----__ [ I --------' I Saddle Mtn Basalt I ***** WNP-1 CH WNP-/ CH WNP-4CI< \VlllP* 1 OH * *WNP-JOH * * * *

• LO\\ler Bound --*Upper Bourid 0 1000 2000 3000 4000 5000 6000 7000 V,(fps)

Site response, Focus Area 1 a Provide additional detail regarding the bases for only a single profile for the upper 525 ft. The geology and depositional processes are also known from the nearby DOE facilities in Hanford (e.g. WTP) The soil properties, specifically shear-wave velocity data, are consistent with the soil type and density The distinctive velocity profile in the top 525 ft is common to the 3 adjacent sites (CGS, WNP-1 and WNP-4) Similar Vs measurements were obtained using different methods with different instruments (cross-hole & down-hole) Seismic refraction measurements agreed well with cross-hole measurements in the top 105 ft at CGS Given the relatively small amount of variation among the measured results, there is a high degree of confidence that any additional measurements would fall close to the base case Vs profile (i.e., low epistemic uncertainty) The variation in soil velocity is adequately covered by consideration of the aleatory uncertainty Site response, Focus Area 1 d Provide additional detail regarding the adequacy of EPRI and Peninsular curves for covering range of nonlinear behavior for the Pasco Gravel. As recommended by the SPID, the EPRI and Peninsular Range curves were used These two sets of nonlinear curves are considered to span the range of nonlinearity for cohesionless soils More recent RCTS data (from other sites) often confirm the adequacy of generic curves for sands and gravels The generic curves were considered appropriate for screening analyses Basalt Flows Profile Provided by PSHA study Velocities measured with PS 0 0 logging and Downhole (DH) ..... : 1 --_,,, methods Two alternative profiles 100 --* r : Weighted 2:1 (DH:PS) -§. ---I r; -Q. --Nonlinear curves for interbeds 0 computed with Darendeli (01) 200 200 ' --. I (D < 15°/o) *--** ** 1 **** , ... F'. ' Site attenuation (Ko) calibrated 300 300 -Site C (profile 1) by recordings -----Site C iproflle 21 0 1000 2000 300C 4000 18 2 22 2.: 26 2.8 3 Vs (mis) p (g'cm') Site response, Focus Area 1 b Provide additional detail regarding the bases for two Vs profiles and their associated weights for the SMB stack. For interbeds, DH and PS Vs values in agreement For basalts Vs from PS .... 25°/o higher than Vs from DH Two Vs profiles created to capture epistemic uncertainty in basalt Vs Vs based on DH favored 2:1 over Vs based on PS DH Vs measured a frequencies near those of interest while PS Vs measured at 1 kHz Experts suggested that reliable PS values in stiff basalts may require use of 5-1 O kHz frequencies Site response, Focus Area 1c (1of2) Provide additional detail regarding the thickness of the interbed deposits including their lateral extent. Based on numerous deep borings, thickness and extent of Ellensburg Formation interbeds mapped across Hanford site Example for Mabton interbed from Rohay and Reidel (2005) MA8TONINTEA8ED * -1 *.: Tl: Site response, Focus Area 1 c (2 of 2) Provide additional detail regarding the thickness of the interbed deposits including their lateral extent Deep wells used to develop SMB stratigraphy at Site C (CGS). Details are in Last (2014) Uncertainty/variability in thickness was included in randomization of layer thicknesses 0 Used for superbasalt sediments and upper Saddle Mountains

• Used for lower Saddle Mountains Dashed where used indirectly 699-13-28' -. (B-35) ** *r " ---* \ . \ . \ ' \ \ " ' ". ' . \ .... . ' 699-15-El J, (DB-2) 01 l. * . . . \ . : ,699-.f2-:1A I ' . I * 'i J I C ' *** ' . *.. . -. .: . (B-36) . -.... I i
• I ' I I ; i / .. .' , . / ( I
• f * / i I "" /' *' / .. . / . . *. /*1'99-2-&14 . ;/ /,/ . .. / l '* .. Based on flow thicknesses from 699*15-15G (DC-8) taken from Landon et al. 1985.

Site response, Focus Area 1 e Provide additional detail regarding the bases for randomizing the small strain damping for the basalt layers in the SMB stack in view of the uncertainty already incorporated into the determination of the site kappa. Randomization is used to address Uncertainty in properties due to measurement error and extrapolation from other locations To characterize spatial variability within the facility footprint. To compensate for simplifications used in conventional 1-D site response analysis methodology Randomization would be applied in SPID methodology even if median properties were known with a high degree of certainty Site response, Focus Area 2 In view of the relatively high shear wave velocities (> 760 mis) and high confining stresses in the interbed layers, provide the rationale for not considering linear behavior of these materials and instead using a single sand curve which demonstrates significant non-linear behavior. lnterbeds are relatively soft rock-like materials even at depth Vs< 1000 mis Some degree of non-linearity expected in such materials at high loading levels, especially because of the large velocity contrasts with the basalts and resulting strain concentrations. Selected the Darendeli (2001) model because it provided a means of incorporating the effect of depth of the interbeds on the G/Gmax and damping relationships. Used only one set of curves with randomization because differences in average response between using alternative sets of median relationships expected to be much smaller that overall uncertainty in defining site ground motions developed for the GMC. Simulated Profiles 0 0 Realization Median 200 200 400 400 Cl) 600 <IJ 600 'O 'O <Cl Cl l3 ;; ;; 0 0 Qi Qi a:i 800 a:i 800 J::. J::. c. c. QI QI 0 0 1000 1000 1200. 1400 0 2000 4000 6000 8000 12000 Shear-Wave Velocity I ft/sec) 10 20 JO Realization 40 50 60 1500 3000 4500 ::. 6000 .... 0 <IJ > 7500 "' "' ., .i::. U'l 9000 10500 12000 .' ... Input Motions PSHA study provided CMS motions at: 20 frequencies 27 MAFEs 4 events M, Rand weight of event I vanes Site response computed for each motion [':' ti fl.I c. t/l i 101 CMS 10° c. . 10 / . ' 0 ;f. "' 10 l Frequency [Hz I 1.0 Hz, AEF: l .Oe-04 -UHR!'> -*.1 '>.6, R: 7 krn, Wt: 0.1'.> '.I R 11 km. Wt: 0 39 '.I . l.l, R: 20 krn, Wt. ->./

• 9.0, R: 3.16 km, Wt* 0.21 Site Response Analysis Total of 2, 160 input rock spectra Two velocity profiles: C1 (downhole) C2 (PS logging) Two nonlinear models for the upper zone: EPRI PR Total of 518,400 soil column analyses Site Response Performed with PSHAKE Uses random vibration theory (RVT) Equivalent-linear wave propagation Control point defined at surface Extracted the site amplification values at the controlling frequency of the CMS motion 70 60 50 1 0 00 J 1 *****Ar1tl"*ue:1*: '.1e;in ' c
• t: *:> *::ic * .! l**en* .-:>rof!le c 1-epn :>erioci 0 100 AEF 1 O*JE** Even: 1 Fr*qu<n<y tltz] 1C 10 (Hz) 'lC * * * *
• Arirhmet1c. Mean -Loganrhm1c. Mean 100 1 D Site Amplification 3.0 0.5 0.0 I 10 Cl*EPRI Frequency [Hz] 10*1 10*l 104 -=-.... ... UJ c: <O QJ ::!: 10 b 107 0.8 07 ci E 06* <t Vi QJ £ 0 0.5. c: .2 :ii s: QJ Cl 0.4 'C .... ro 'C c: <O ., VI .., 03* E .r::. ., *;:::: <O 0-0 ...J 0.2 -<O ;Q Cl*EPRI Frequency [Hz) 101 10 J u.. UJ c: <O QJ 10 '* :r lOb 10 7 1 D log Mean Site Amplification := 100 00 Hz 1= Q. 10 -----------------........ __ f 101) 1. I: 33.33 Hzll 1* I* "oo "'I w* 10 I'--------------------------------_. "---*_.:'_-..........____.-..__.J I :::I.__ ---'----I*_-......... 'I 1100011 l ___ ----101 10) Input PSA at J(gJ 10 l lOO Input PSA at f [gJ I :::r ------l:"'"II .___ __ ............... ""'I llOOv1* 1 -.._, I* "'"ii f _ ___..___I* . .........___,! oo Hzl : -I . ----l*-""'ll .....___ _1'"'""1 :-l'"'"II I* O!Ht,11 1 _________ OIOHll --I JO 1 10<* 101 I "'.I 10 10) I 10 l 10' 101 10" PSA at J [ g] Input PSA at J [gl GMRS-Approach 3 Approach 3 (Bazzurro and Cornell, 2004): Gz(z) = I Gv1x (: lxj) Px(Xj) all Xj Gz(z) = Horizon specific hazard curve Px(xj) = probability of rock input level (i.e., slope of input hazard curve) (z ) ln[mv1x(x)] Gy1x -lxj = <p X (J'lnYIX where fP = 1 -<p is the complementary standard Gaussian CDF my1x(x) = mean amplification factor (Jznvix = sigma of amplification factor GMRS-Approach 3 Input Hazard Curves from PSHA Input Site Amplification Results Two Profiles: Profile C1 (0.67) Profile C2 (0.33) Two Material Curves: EPRI (0.5) Peninsular Range (0.5) No Minimum Amplification Factor Hazard Curves: PGA Approach 3 Results: CGS, Mean (No Min), 100 Hz 1.0E-02 ....... l.OE-03 1.0E-01\ 1.0E-05 <1.'. 1.0E-06 --Input HC ------Cl-EPR I *******Cl-Pen 1.0E-07 C2-EPRI -----C2-Pen --Average HC 1.0E-08 0.01 0.1 1 PGA (g) 10 UHRS: Mean, AEP=1 o-4 10 1 0.1 0.01 *
• 0.1 * * . * . * . . ** * . * * * . . ** * .
• UHRS: CGS, Mean (No Min), AEP=l0-4 . . . . * . * . * . .
• 1 . * ** * *** **** .. ** ** ** Frequency (Hz) **************** *** * ** *****Hard Rock (10-'1) -Approach 3 (10-11) 10 ***** 100 UHRS: Mean, AEP=1 o-s 10 1 0.1 0.01 UHRS: CGS, Mean (No Min), AEP=l0-5 , ..... , ' , ************************** ,-' .. .. , .. r .** ' , .. ** ' , .** ,, ,,, . .... .** ............... , .* ........ . * ....... ,' .. ** ---' .* I *** I ** , .** , .* , .* , .** , .* , .. * , .* , .. , .. ,_ .. ** *****Hard Rock (10-5) --*Appro,Kh 3 (10-5) 0.1 1 10 100 Frequency (Hz)

Surface UHS and GMRS 3 -2 c 0 r:J ... ..., v (,/ Q. V"l 1 0 .l 0 0.1 ,1 , -, , , 4' I\ I \ I \ I ' I ' ' ' ' ' ' ' I t ' ' . -* ' ," ' I ' I I I \ I \ I \ I \ ' \ ' , ' , , ' . . ' -I ', / . 1 10 100 Frequency (Hz) Site response, Focus Area 3 Provide additional detail regarding the decision not to implement a minimum site amplification value and the effect of this decision on the development of the uncertainty in the site amplification function as well as on the final hazard curves for the site. The 0.5 limit is not used in the calculation of the surface hazard because the intended purpose of this report is to obtain the realistic and unbiased median based site amplification for SRA The basis for limitation of 0.50 is not well documented and is more relevant for additional conservatism under design applications

Interim Actions -FLEX strategy Columbia has significant flexibility for connection of portable electrical supplies following a seismic event Two portable 480 V AC diesel generators on-site Two redundant 480 VAC connection points to two safety divisions One additional 480 VAC connection point to either of two safety divisions 4160 VAC diesel generators available through SAFER Two 4160 VAC connection points to two safety divisions One additional 4160 VAC connection point capable of supplying either safety division Installed breakers and cabling allow safety divisions to be cross-tied if needed Interim Actions -FLEX strategy Columbia has significant flexibility for connection of portable pumps to supply cooling water to the core and suppression pool Two portable diesel powered pumps (high head) available onsite Injection points available on all three divisions of Residual Heat Removal (RHR) High capacity pump available through SAFER Injection point available on the Condensate system Connection points on the both divisions of Standby Service Water (SW) with piping cross-connected to RHR Inventory source is the normal plant ultimate heat sink (two SW spray ponds) Interim Evaluation -Seismic Current Seismic Probabilistic Risk Assessment (SPRA) -Mean Seismic Core Damage Frequency is calculated to be 4.9 x1 o-6 Based upon a hazard curve developed in terms of peak ground acceleration (PGA) and fragilities in terms of PGA Current SPRA maintained in alignment with the RG 1.200-compliant Internal Events modeling and is significantly advanced beyond IPEEE requirements Reanalysis of Mean Seismic Core Damage Frequency at PGA using new ground motion response spectrum indicates margin remains Seismic walk downs completed satisfactory as required by Enclosure 3 of the NRC's CFR 50.54(f) Request for Information All results satisfactory Path Forward Energy Northwest is initiating the Expedited Seismic Evaluation Process Report due Jan 2016 Energy Northwest is initiating SPRA in accordance with SPID requirements Submittal due Jun 2017 OENERGY NORTHWEST March 12, 2015 G02-15-045 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk 11555 Rockville Pike Rockville, MD 20852 David A. Swank Columbia Generating Station P .0. Box 968, PE04 Richland, WA 99352-0968 Ph.509-377-2309 I F.509-377-2354 daswank@energy-northwest.com

Reference:

1 O CFR 50.54(f)

Subject:

COLUMBIA GENERATING STATION, DOCKET NO. 50-397 SEISMIC HAZARD AND SCREENING REPORT, RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO 10 CFR 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE REVIEW OF INSIGHTS FROM THE FUKUSHIMA DAl-ICHI ACCIDENT

References:

1) NRG Letter, Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Recommendations 2.1, 2.3, and 9.3, of the Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accident, dated March 12, 2012, ADAMS Accession Nos. ML 12056A046 (Pkg.), ML 12053A340 (Ur.) 2) EPRI Report 1025287, Seismic Evaluation Guidance, Screening, Prioritization and Implementation Details (SPID} for the Resolution of Fukushima Near-Term Task Force Recommendation 2.1: Seismic, ADAMS Accession No. ML 12333A 170 3) NRG Letter, Endorsement of EPRI Final Draft Report 1025287, "Seismic Evaluation Guidance," dated February 15, 2013, ADAMS Accession No. ML12319A074

Dear Sir or Madam:

On March 12, 2012, the Nuclear Regulatory Commission (N RC) issued Reference 1 to all power reactor licensees and holders of construction permits in active or deferred status. Enclosure 1 of Reference 1 requested that each addressee located in the Western United States (WUS) submit a Seismic Hazard Evaluation and Screening Report within 3 years from the date of Reference 1. Reference 2 contains industry guidance and detailed information to be included in the Seismic Hazard Evaluation and Screening Report submittals. NRC endorsed this industry guidance in Reference 3. SEISMIC HAZARD AND SCREENING REPORT1 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO 10 CFR 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE REVIEW OF INSIGHTS FROM THE FUKUSHIMA DAIRICHI ACCIDENT Page 2 of 2 Enclosed is the Seismic Hazard and Screening Report for the Columbia Generating Station. This report provides the information requested in Reference 1, Enclosure 1 and its Attachment 1. The Hanford Sitewide Probabilistic Seismic Hazard Analysis referenced in the report, is available on the Department of Energy's Hanford external website. The direct link is: http://www. hanford .gov/page .cfm/Official Docume nts/HSPSHA. No new commitments are identified in this letter. If you have any questions or require additional information, please contact Ms. L. L. Williams at (509) 377-8148. I declare under penalty of perjury that the foregoing is true and correct. '* 1 ft I Executed on the id_ day of lvf /'c tj , 2015 Respectfully, , D. A. Swank Assistant Vice President, Engineering

Enclosure:

As stated cc: NRC Region IV Administrator NRC NRA Project Manager NRC Senior Resident lnspector/988C MA Jones -BPA/1399 (email) RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Enclosure COLUMBIA GENERATING STATION, DOCKET NO. 50*397 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR* TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION This report provides information in response to NRC's March 12, 2012, 10 CFR 50.54(f) letter requesting nuclear power plant licensees to perform seismic hazard reevaluation and screening for risk evaluation pursuant to the recommendations in NRC's Near-Term Task Force review of the accident at the Fukushima Dai-ichi nuclear facility. 1 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 1.0 Introduction Following the accident at the Fukushima Daiichi nuclear power plant resulting from the March 11, 2011, Great Tohoku Earthquake and subsequent tsunami, the NRC Commission established a Near Term Task Force (NTTF) to conduct a systematic review of NRC processes and regulations and to determine if the agency should make additional improvements to its regulatory system. The NTTF developed a set of recommendations intended to clarify and strengthen the regulatory framework for protection against natural phenomena. Subsequently, the NRG issued a 50.54(f) letter that requests information to assure that these recommendations are addressed by all U.S. nuclear power plants. The 50.54(f) letter requests that licensees and holders of construction permits under 10 CFR Part 50 reevaluate the seismic hazards at their sites against present-day NRG requirements. Depending on the comparison between the reevaluated seismic hazard and the current design basis, the result is either no further risk evaluation or the performance of a seismic risk assessment. Risk assessment approaches acceptable to the staff include a seismic probabilistic risk assessment (SPRA), or a seismic margin assessment (SMA). Based upon the risk assessment results, the NRG staff will determine whether additional regulatory actions are necessary. This report provides the information requested in items (1) through (7) of the "Requested Information" section and Attachment 1 of the 50.54(f) letter pertaining to NTTF Recommendation 2.1 for the Energy Northwest Columbia Generating Station {CGS), located in Benton County in the State of Washington. In earlier licensing documentation, the CGS plant was referred to as Washington Public Power Supply System Nuclear Project Number 2 (WNP-2). In providing this information, Energy Northwest (EN) followed the guidance provided in the Seismic Evaluation Guidance: Screening, Prioritization, and Implementation Details (SPID) for the Resolution of Fukushima Near-Term Task Force Recommendation 2.1: Seismic (EPRI, 2013a). The Augmented Approach, Seismic Evaluation Guidance: Augmented Approach for the Resolution of Fukushima Near-Term Task Force Recommendation 2.1: Seismic {EPRI, 2013b), has been developed as the process for evaluating critical plant equipment as an interim action to demonstrate additional plant safety margin, prior to performing the complete plant seismic risk evaluations. The original geologic and seismic siting investigations for CGS were performed in accordance with Appendix A to 1 O CFR Part 100 and meet General Design Criterion 2 in Appendix A to 1 O CFR Part 50. The Safe Shutdown Earthquake {SSE) ground motion was developed in accordance with Appendix A to 10 CFR Part 100 and used for the design of Seismic Category I systems, structures and components. In response to the 50.54(1) letter and following the guidance provided in the SPID (EPRI, 2013a) with due consideration to the extensive site soil profile data available for the plant site, a seismic 2 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure hazard reevaluation was performed. For screening purposes, a Ground Motion Response Spectrum (GMRS) was developed. Based on the results of the screening evaluation, CGS screens in for a risk evaluation, a Spent Fuel Pool evaluation, and a High Frequency evaluation as part of the risk evaluation. 3 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 2.0 Seismic Hazard Reevaluation CGS is located on the eastern side of the Hanford Site. As discussed in PNNL (2014), the Hanford Site is located east of the region tectonically dominated by the Cascadia subduction zone (CSZ), where the Juan de Fuca (JDF) plate under-thrusts northern California and western Oregon and Washington along the Cascadia subduction zone. Magmatism related to the subduction zone is represented by the Cascade volcanoes, which lie to the west of the Hanford Site. Following establishment of the Cascadia subduction zone and related volcanic chain, the later geologic history of eastern Washington was dominated by eruption and deposition of the Columbia River Basalts (CRBs). The CRB flows in eastern Washington are deformed in a series of generally east-west-trending anticlines underlain by reverse faults that are known collectively as the Yakima Fold Belt (YFB). The reverse faults of the YFB dominate the post-CRB tectonics and topography in eastern Washington. The Yakima folds are anticlines that have accommodated approximately north-south shortening. Seismicity and geodetic indicators of contemporary tectonics confirm that north-south stresses continue to be the dominant stress mechanism. However, the rates of shortening, uplift, and fault slip, as recorded by the deformation of various units of the CAB, show that rates of deformation are low relative to the slip rates of f au Its within active tectonic regions. The Hanford Site is characterized by a relatively thin layer of supra-basalt sediments (mainly the Hanford and Ringold formations), which have thicknesses ranging from 200 to 660 ft (60 to 200 m) at five sites across the Hanford Site investigated by PNNL (2014). These sediments are underlain by the basalt flows of the Saddle Mountain Basalts (SMB) sequence and interbedded Ellensburg formation sediments; the basalt-interbed stacks have a thickness of about 820 ft (250 m) at the PNNL sites. Below the SMB are the Wanapum Basalts and Grande Ronde Basalts, collectively forming the CRB, with a total thickness of 1.2 to 1.9 mi (2 to 3 km) at the PNNL sites. The CAB is underlain by a thick layer of pre-Miocene sediments, with the crystalline basement encountered at depths ranging from 4.7 to 5.6 mi (7.5 to 9 km) at the five PNNL sites. Regional seismicity in the YFB region is dominated by small-magnitude earthquakes that occur within the CRB units in the upper 1.9 mi (3 km), and more diffuse seismicity that extends to depths of about 12.4 mi (20 km). Rates of moderate-to-large earthquakes are low relative to plate boundary regions. Within the YFB region, the largest observed earthquakes are the 1936 Milton-Freewater earthquake (M 6) and the 1872 Lake Chelan earthquake (M 6.5-7). To the west of the site region, earthquakes are mainly associated with the Cascadia subduction zone and Holocene crustal faults in the Puget Lowland. The following section discusses the regional and local geology (Section 2.1 ), the probabilistic seismic hazard analysis (Section 2.2), the development of site profiles and site response analyses (Section 2.3), and the control point response spectrum {Section 2.4). 4 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 2. 1 Regional and Local Geology The CGS site lies in the Pasco Basin which encompasses about 1,600 square miles in south central Washington State. It is one of several physiographic depressions occupying the Columbia Plateau, a major physiographic and geologic province that is surrounded by the Blue Mountains, High Lava Plains and Snake River Plains provinces on the south, the Northern Rocky Mountains and Idaho Batholith provinces on the east, the Okanogan Highlands province to the north, and the Cascade Mountains, Puget-Willamette Trough, and Washington-Oregon Coast Ranges on the west. Bedrock in the Columbia Plateau consists of a thick sequence of Miocene Basalt flows with minor amounts of interflow sediments, known as interbeds. These rocks, generally mantled by younger sediments of Pliocene and Holocene age, are termed the Columbia River Basalts (CRBs). The CRBs cover about 77,000 square miles in Washington, Oregon and western Idaho. The CRBs consist of the Yakima Basalt Sub-Group (which includes the Saddle Mountains Basalt, Wanapum Basalt and Grande Ronde Basalt) and the lmnaha Basalt. Estimated extrusion period of the CRB is between 6 million and 17 million years ago. The CRBs, particularly in the western part of the Columbia Plateau, have been folded into a series of east-west anticlines. The Pasco Basin is a gently undulating, semiarid plain, interrupted by low-lying hills and dunes that are dissected by intermittent streams. The basin is transected by the Columbia River. The CGS reactor is located just over 3 miles west of the Columbia River on the eastern edge of the Hanford Site. The CGS site, which covers about 1, 100 acres, is essentially flat -average surface elevation prior to construction was 440 ft, with a variation of about 4 ft across the site. Plant grade is El. 441 ft. Depth to the groundwater table is about 62 ft. The CGS site is immediately underlain by about 45 ft thickness of Pasco Gravel, a Quaternary deposit made up of glaciofluvial sediments. It is noted that at and around the control point the Pasco gravel was removed and replaced with compacted structural backfill. The Pasco Gravel and structural fill are underlain by the Pliocene-age Ringold Formation, consisting of the Middle Member down to 250 ft depth and the Lower Member down to 525 ft depth. The Ringold is predominantly a sandy gravel with interbedded sandy and silty layers (Middle Member) and some interbedded soft sandstone and some conglomerate present at the base of the layer (Lower Member). Several hundred ft of the Ringold Formation materials at the site were removed during Pleistocene floods. The overlying Pasco Gravel was deposited over the eroded surface of the Ringold Formation materials. The Pasco Gravel at the site has not been subjected to significant past loading. At the CGS site, the top of the CRB occurs immediately below the Ringold Formation, at 525 ft depth. The Saddle Mountains Basalt forms the upper approximately 765 ft of the CRB at the site, ranging from about 10.5 million years old at the top (Elephant Mountain Member) to 13.5 million 5 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure years old (Umatilla Member) at the base. There are four basalt members within the Saddle Mountains Basalt that range from about 110 ft to 215 ft in thickness, each underlain by a sedimentary interbed consisting mainly of sandstone and claystone, and ranging in thickness from about 15 ft to 70 ft. The interbeds have significantly lower strength and density than the basalt. The Saddle Mountains Basalt comprises less than 1% of the volume of the CRB, but perhaps because of their relatively long period of extrusion at a time of waning volcanism, members of the Saddle Mountains Basalt display the greatest petrographic, chemical and paleomagnetic variability of any formation of the CRB. All stratigraphic units beneath the site appear to be nearly horizontal. The Wanapum Basalt beneath the Saddle Mountains Basalt is approximately 1,000 ft thick and is between about 13.5 and 14 million years old. It consists of the Priest Rapids Member, the Roza Member, the Frenchman Springs Member, and the Eckler Mountain Member. The Priest Rapids Member contains the Lolo Flow (about 155 ft thick) underlain by the Rosalia Flow (60 ft thick). The Grande Ronde Basalt below the Wanapum Basalt is approximately 7,200 ft thick. 2.2 Probabilistic Seismic Hazard Analysis Section 2.2 summarizes the results of a probabilistic seismic hazard analysis (PSHA) of the CGS located within the boundaries of the Hanford Site in south central Washington State The PSHA was performed by the Pacific Northwest National Laboratory (PNNL) in accordance with the provisions of the Nuclear Regulatory Commission (NRC, 2014a) 50.54(1) letter and in fulfillment of the requirement from the U.S. Nuclear Regulatory Commission that Energy Northwest conduct a PSHA using Senior Seismic Hazard Analysis Committee (SSHAC) Level 3 procedures (see Appendix 2.2A}. The PNNL report (2014) provides a detailed characterization of the vibratory hard-rock motion hazard at the CGS location from potential future earthquakes conducted using the Level 3 procedures advanced by SSHAC in detailed guidance published by the U.S. Nuclear Regulatory Commission (see Appendix 2.2A for a description of the SSHAC Level 3 process as used for this PSHA). In accordance with this guidance, a participatory peer review panel (PPRP) oversaw all details of the performance of the PSHA and confirmed that the work was done in conformance with SSHAC guidance. This confirmation is provided in a PPRP closure letter (see Appendix 2.2B). 2.2. 1 Probabilistic Seismic Hazard Analysis Results PNNL (2014) report is the source of the information presented in the following section. 6 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure The summary presented here is of the base case rock hazard at the CGS using the seismic source characterization (SSC) and ground motion characterization {GMC) models of the PNNL (2014) report, Chapters 8.0 and 9.0, respectively. A cumulative absolute velocity filter was not applied in this analysis and no site amplification factors are used. Results are consistent with hard-rock conditions {for this site rock with a shear-wave velocity, V5, very close to 9,800 ft/s or 3,000 mis). The methodology for seismic hazard analysis is well established in the technical literatures (e.g., McGuire, 2004). Three sets of seismic sources are included in the SSC model and are identified below: Subduction source zones (discussed in Section 8.2 of the PNNL report) Crustal area source zones {discussed in Section 8.3 of the PNNL report) Crustal fault sources (discussed in Section 8.4 of the PNNL report) The list of all seismic sources and acronyms used in this analysis are provided in Table 2.2.2-3. This list of sources represents a hazard-informed compilation of all sources that would be expected to contribute significantly to the site hazard, based on the hazard sensitivity analyses. The identification and characterization of seismic sources for the SSC model gave highest priority to aspects of the model that had the highest potential hazard significance, and the level of complexity of the SSC model was consistent with current knowledge and importance to hazard. Sensitivity analyses conducted early in the Hanford PSHA project showed that the plate interface seismic source of the CSZ could contribute to long-period ground motions at mean annual frequencies of exceedance {MAFE) of interest to the Hanford Site. For completeness, both the plate interface zone (CSZ) and the intraslab source (JDF) are included in the SSC model. The seismic area source zones defined for the SSC model are shown in Figure 8.1 of the PNNL (2014) report, together with the earthquake epicenters from the project catalog. All seismic area source zones are assessed to be seismogenic with a probability of unity. Two types of seismic area source zones are identified: 1) the YFTB source zone is a "background" zone to the fault sources of the Yakima Fold and Thrust Belt and 2) Zones B, C, and Dare crustal area source zones that do not include identified fault sources. The exceptions are the Arlington (AF), Luna Butte (LB), Laurel {LF), and Maupin (MF) faults that exist within the YFTB background source zone and extend into adjacent Zone D. However, additional faults within Zone D have not been identified separately as fault sources. The reason for the two types of source zones is the relative contribution that nearby sources make to the hazard at the site. Because of their distance from the site, individual faults within Zones B, C, and D are not specifically identified and characterized. Rather, the faults that exist within these source zones are modeled by 7 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure "virtual faults" whose locations are random within each zone and whose characteristics are assessed in the SSC model. The twenty faults whose closest approach lies within about 12.4 mi (20 km) of the site and that were assessed to have a seismogenic probability greater than zero are included in the SSC model (Figure 8.2 of the PNNL (2014) report). In addition, the Seattle fault zone (SFZ) is included in the model for completeness. Sensitivity analyses show that it does not contribute significantly to the hazard at the site because of its distance from the site, but it is included in the model as being representative of faults that exist within the Puget Sound region. With the exception of four faults within the YFTB background source all faults were assessed, like the seismic areas sources, to have a seismogenic probability of unity. Fault trees capturing variation of a number of parameters selected to capture the epistemic uncertainty in the characterization of the three sets of seismic sources are outlined as Figures 8.3 through 8.7 of the PNNL (2014) report. All elements of the SSC model are included in the hazard input document (HID) provided in Appendix D of the PNNL (2014) report. The ground motion characterization (GMC) model consists essentially of two logic trees, one for ground motions from crustal earthquakes (both area and fault) and the other for motions caused by subduction earthquakes (both intraslab and interface), taking into account magnitude and distance ranges appropriate for each group and, for the shallow crustal fault sources, appropriate fault rupture characteristics. In both the shallow crustal and subduction source cases, GMC models represent spectral acceleration at 5% of critical damping and apply to the base rock elevation at the top of the Wanapum Basalts, which have a shear-wave velocity (Vs) very close to 9,840 ft/s (3,000 mis). For both the crustal and subduction logic trees, there are branches for the median motions and also for the associated aleatory variability (sigma). The GMC model is defined by suites of equations with coefficients at twenty spectral frequencies ranging from O. 1 Hz to 100 Hz, which were selected in agreement with the project sponsors and which include the seven spectral frequencies {100 Hz, 25 Hz, 10 Hz, 5 Hz, 2.5 Hz. 1 Hz, and 0.5 Hz) specified in the NRC's 50.54(f) letter (NRC, 2012a). All of the information in the GMC logic tree is presented in the HID, which is included as Appendix D of the PPNL (2014) report. 2.2.2 Base Rock Seismic Hazard Curves Mean seismic hazard curves at CGS are calculated for base rock site conditions (Site C: PNNL, 2014). 8 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure The procedure to develop probabilistic seismic hazard curves for base rock follows standard techniques documented in the technical literatures (e.g., McGuire, 2004). Separate seismic hazard calculations are conducted for twenty spectral frequencies (or periods) ranging from 0.1 Hz (10 seconds) to PGA or 100 Hz (0.01 seconds), as available in supplemental digital material of Appendix J of PNNL (2014). Presented in this report are the results for seven spectral frequencies: PGA (100 Hz), 25 Hz, 10 Hz, 5 Hz, 2.5 Hz, 1 Hz, and 0.5 Hz. The SSC and GMC models discussed in Section 2.2.1 are used for the calculation of the mean base rock hazard. All spectral accelerations presented herein correspond to 5% of critical damping (PNNL, 2014). Figure 2.2.2-1 shows the mean base rock hazard curves for the seven spectral frequencies. Table 2.2.2-1 lists the mean rock uniform hazard response spectra (UHAS) for MAFEs of 10*4, 10-5, and 1 o*6 for twenty spectral periods. The digital values for the mean and fractile hazard curves are provided in Tables 2.2.2-2a through 2.2.2-2g. Deaggregations of the total mean seismic hazard for 10 Hz (0.1 s) and 1 Hz (1.0 s) spectral accelerations at MAFEs of 10'4 and 10*5 hazard levels are shown in Figure 2.2.2-2. Each figure contains histograms representing the percent contribution to the total mean seismic hazard from different magnitude-distance bins. For 10 Hz spectral acceleration the mean hazard at the two MAFEs is dominated by source zones (small magnitudes at distances of less than 62 mi (100 km)), which, as will be seen, is especially attributable to the YFTB background source. For 1 Hz spectral acceleration the mean hazard at the two MAFEs is clearly being impacted by the distant, very large magnitude Cascadia subduction zone, though the relative contribution is higher at an MAFE of 10-4 than at 10*5 hazard levels. At the lower hazard level of 1 o*5, the 1 Hz mean hazard, while the small-to-moderate magnitude sources at near distances are still dominant (YFTB background source), the Cascadia subduction zone and moderate-to-large earthquakes at distances between 6.2 to 31 mi (1 Oto 50 km), attributable to crustal fault sources. appear near equal contributors to about half of the hazard. Deaggregation is also presented as a function of the contribution of the individual seismic sources. Figures 2.2.2-3 and 2.2.2-4 are plots, 10 Hz and 1 Hz, respectively, of the comparison between the mean hazard curves at CGS (Site C in PNNL, 2014) obtained for each individual source relative to the total mean hazard. Acronyms used in these figures are listed in Table 2.2.2-3. By inspection of these figures, Table 2.2.2-3 also indicates those sources contributing more than 5% toward the total 10 Hz and/or 1 Hz mean hazard of the site for MAFEs between 10'4 and 10'5 hazard levels, the MAFEs of specific interest in the estimation of the ground motion response spectrum (GMRS). presented later in this report. Columbia Generating Station is located within the YFTB background zone that clearly dominates the high frequency seismic hazard at the MAFEs of interest (Figure 2.2.2-3), while both the YFTB background zone and the Cascadia subduction (interface) zone (CSZ) generally 9 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure dominate the low frequency hazard {Figure 2.2.2-4). The Juan de Fuca (JDF) intraslab subduction source contributes little to the total mean hazard. Table 2.2.2-1: Mean Rock UHAS at 5% Damping for MAFEs of 10*4, 10*5, and 10*5 Period [s] 10*4 UH RS [g] 10*0 UHRS [g] 10*0 UHAS [g] 0.01 6.366E-01 1.866E+OO 4.132E+OO 0.02 7.817E-01 2.138E+OO 4.494E+OO 0.03 8.189E-01 2.169E+OO 4.469E+OO 0.04 8.272E-01 2.145E+OO 4.369E+OO 0.05 8.206E-01 2.100E+OO 4.246E+OO 0.075 7.976E-01 2.001E+OO 3.997E+OO 0.1 7.536E-01 1.854E+OO 3.689E+OO 0.15 6.528E-01 1.590E+OO 3.150E+OO 0.2 5.878E-01 1.422E+OO 2.808E+OO 0.3 4.828E-01 1.157E+OO 2.292E+OO 0.4 3.873E-01 9.41 SE-01 1.870E+OO 0.5 3.218E-01 7.797E-01 1.531 E+OO 0.75 2.142E-01 5.154E-01 1.030E+OO 1 1.541E-01 3.643E-01 7.277E-01 1.5 1.032E-01 2.301 E-01 4.430E-01 2 7.755E-02 1.699E-01 3.231 E-01 3 5.289E-02 1.110E-01 2.052E-01 5 3.403E-02 7.136E-02 1.282E-01 7.5 2.237E-02 4.648E-02 8.448E-02 10 1.651 E-02 3.454E-02 6.261 E-02 10 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.2.2-2a: Annual Frequency of Exceedance Mean and Fractile Base Rock Seismic Hazard Curves for PGA at Columbia Generating Station (PNNL, 2014) Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile PGA[g] AFE AFE AFE AFE AFE AFE 0.0001 9.358E-02 6.166E-02 7.079E-02 8.71 OE-02 1.122E-01 1.514E-01 0.0005 8.240E-02 5.370E-02 6.166E-02 7.762E-02 1.000E-01 1.259E-01 0.001 7.063E-02 4.169E-02 5.012E-02 6.761 E-02 8.913E-02 1.096E-01 0.003 4.548E-02 1.995E-02 2.570E-02 3.981 E-02 6.607E-02 8.511 E-02 0.01 2.017E-02 5.623E-03 7.762E-03 1.413E-02 3.548E-02 5.370E-02 0.03 7.029E-03 1.202E-03 1.862E-03 3.890E-03 1.259E-02 2.455E-02 0.05 3.939E-03 5.248E-04 8.511 E-04 1.905E-03 7.079E-03 1.479E-02 0.075 2.406E-03 2.455E-04 4.266E-04 1.047E-03 4.365E-03 9.SSOE-03 0.1 1.667E-03 1.288E-04 2.399E-04 6.607E-04 3.020E-03 6.918E-03 0.2 6.459E-04 1.778E-05 4.266E-05 1.738E-04 1.202E-03 3.020E-03 0.3 3.532E-04 4.074E-06 1.175E-05 6.457E-05 6.607E-04 1.778E-03 0.5 1.544E-04 4.266E-07 1.660E-06 1.413E-05 2.630E-04 8.511 E-04 0.75 7.447E-05 5.012E-08 2.512E-07 3.236E-06 1.072E-04 4.365E-04 1 4.219E-05 8.71 OE-09 5.495E-08 9.772E-07 5.012E-05 2.570E-04 2 8.523E-06 5.495E-11 6.761 E-10 3.090E-08 5.370E-06 4.786E-05 3 2.786E-06 1.445E-12 3.020E-11 2.754E-09 1.023E-06 1.380E-05 5 5.433E-07 7.586E-15 3.467E-13 8.128E-11 8.511 E-08 2.042E-06 7.5 1.212E-07 3.631 E-17 7.079E-15 3.631 E-12 8.511 E-09 3.388E-07 10 3.712E-08 O.OOOE+OO 2.344E-16 3.548E-13 1.349E-09 7.943E-08 20 1.412E-09 O.OOOE+OO O.OOOE+OO 1.31 SE-15 9.120E-12 1.318E-09 11 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.2.2-2b: Annual Frequency of Exceedance Mean and Fractile Base Rock Seismic Hazard Curves for 5% Damped 25 Hz SA at Columbia Generating Station (PNNL, 2014) Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile SA [g] AFE AFE AFE AFE AFE AFE 0.0001 9.356E-02 6.166E-02 7.079E-02 8.71 OE-02 1.122E-01 1.514E-01 0.0005 8.408E-02 5.370E-02 6.310E-02 7.943E-02 1.023E-01 1.288E-01 0.001 7.406E-02 4.365E-02 5.248E-02 7.079E-02 9.333E-02 1.148E-01 0.003 5.114E-02 2.138E-02 2.884E-02 4.786E-02 7.244E-02 8.913E-02 0.01 2.483E-02 6.457E-03 9.772E-03 1.995E-02 4.266E-02 5.495E-02 0.03 9.315E-03 1.549E-03 2.512E-03 6.31 OE-03 1.778E-02 2.455E-02 0.05 5.41 OE-03 7.079E-04 1.230E-03 3.388E-03 1.047E-02 1.514E-02 0.075 3.414E-03 3.467E-04 6.607E-04 2.042E-03 6.761 E-03 1.000E-02 0.1 2.426E-03 1.950E-04 4.074E-04 1.380E-03 4.898E-03 7.413E-03 0.2 1.002E-03 3.311 E-05 9.333E-05 4.786E-04 2.138E-03 3.388E-03 0.3 5.670E-04 8.913E-06 3.090E-05 2.188E-04 1.230E-03 2.042E-03 0.5 2.545E-04 1.202E-06 5.623E-06 6.457E-05 5.754E-04 1.023E-03 0.75 1.222E-04 1.778E-07 1.122E-06 2.042E-05 2.754E-04 5.248E-04 1 6.780E-05 3.802E-08 3.020E-07 7.762E-06 1.514E-04 3.090E-04 2 1.232E-05 4.571E-10 6.918E-09 4.786E-07 2.399E-05 6.310E-05 3 3.682E-06 2.042E-11 4.898E-10 6.607E-08 6.166E-06 1.950E-05 5 6.265E-07 2.692E-13 1.122E-11 3.802E-09 8.128E-07 3.311 E-06 7.5 1.245E-07 6.166E-15 4.467E-13 2.818E-10 1.202E-07 6.166E-07 10 3.526E-08 1.000E-16 4.266E-14 3.890E-11 2.630E-08 1.660E-07 20 1.157E-09 O.OOOE+OO 1.122E-16 3.236E-13 3.71SE-10 4.074E-09 12 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.2.2-2c: Annual Frequency of Exceedance Mean and Fractile Base Rock Seismic Hazard Curves for 5% Damped 10 Hz SA at Columbia Generating Station (PNNL, 2014) Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile SA [g] AFE AFE AFE AFE AFE AFE 0.0001 9.372E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.514E-01 0.0005 8.421 E-02 5.623E-02 6.457E-02 7.943E-02 1.000E-01 1.259E-01 0.001 7.411 E-02 4.786E-02 5.623E-02 7.079E-02 9.120E-02 1.072E-01 0.005 3.855E-02 1.905E-02 2.512E-02 3.715E-02 5.248E-02 6.31 OE-02 0.01 2.391 E-02 1.000E-02 1.413E-02 2.291 E-02 3.388E-02 4.169E-02 0.02 1.318E-02 4.786E-03 6.918E-03 1.202E-02 1.950E-02 2.512E-02 0.05 5.174E-03 1.479E-03 2.344E-03 4.571 E-03 7.943E-03 1.096E-02 0.1 2.346E-03 5.370E-04 9.120E-04 1.995E-03 3.802E-03 5.370E-03 0.2 9.721 E-04 1.445E-04 2.951 E-04 7.762E-04 1.660E-03 2.455E-03 0.3 5.397E-04 5.370E-05 1.288E-04 4.074E-04 9.550E-04 1.445E-03 0.5 2.276E-04 1.148E-05 3.548E-05 1.514E-04 4.266E-04 6.918E-04 0.75 1.011 E-04 2.692E-06 1.000E-05 5.754E-05 1.950E-04 3.388E-04 1 5.253E-05 8.128E-07 3.631 E-06 2.S?OE-05 1.023E-04 1.905E-04 1.5 1.848E-05 1.202E-07 6.918E-07 6.918E-06 3.548E-05 7.413E-05 2 8.032E-06 2.570E-08 1.820E-07 2.399E-06 1.514E-05 3.467E-05 3 2.158E-06 2.239E-09 2.239E-08 4.467E-07 3.71 SE-06 9.772E-06 5 3.225E-07 6.026E-11 9.772E-10 3.631 E-08 4.786E-07 1.549E-06 7.5 5.844E-08 2.239E-12 5.754E-11 3.631 E-09 7.079E-08 2.754E-07 10 1.566E-08 1.778E-13 6.457E-12 5.888E-10 1.585E-08 7.244E-08 20 4.656E-10 2.818E-16 2.344E-14 4.677E-12 2.630E-10 1.778E-09 13 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.2.2-2d: Annual Frequency of Exceedance Mean and Fractile Base Rock Seismic Hazard Curves for 5% Damped 5 Hz SA at Columbia Generating Station (PNNL, 2014) Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile SA [g] AFE AFE AFE AFE AFE AFE 0.0001 9.441 E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.514E-01 0.0005 8.809E-02 5.888E-02 6.761 E-02 8.318E-02 1.047E-01 1.349E-01 0.001 7.878E-02 5.370E-02 6.166E-02 7.586E-02 9.550E-02 1.148E-01 0.005 4.042E-02 2.399E-02 2.951 E-02 3.890E-02 5.129E-02 6.166E-02 0.01 2.427E-02 1.31 SE-02 1.660E-02 2.344E-02 3.236E-02 3.890E-02 0.02 1.290E-02 6.166E-03 8.128E-03 1.230E-02 1.738E-02 2.188E-02 0.05 4.750E-03 1.950E-03 2.692E-03 4.365E-03 6.761 E-03 8.913E-03 0.1 1.986E-03 7.079E-04 1.047E-03 1.778E-03 2.951 E-03 3.981 E-03 0.2 7.420E-04 2.138E-04 3.311 E-04 6.310E-04 1.148E-03 1.622E-03 0.3 3.828E-04 8.511 E-05 1.479E-04 3.162E-04 6.026E-04 9.120E-04 0.5 1.441 E-04 2.138E-05 4.266E-05 1.096E-04 2.399E-04 3.890E-04 0.75 5.762E-05 5.495E-06 1.259E-05 3.890E-05 1.000E-04 1.738E-04 1 2.759E-05 1.820E-06 4.677E-06 1.698E-05 4.898E-05 8.913E-05 1.5 8.565E-06 3.090E-07 9.SSOE-07 4.365E-06 1.514E-05 3.090E-05 2 3.383E-06 7.244E-08 2.630E-07 1.445E-06 5.888E-06 1.288E-05 3 7.889E-07 7.244E-09 3.388E-08 2.570E-07 1.31 SE-06 3.311 E-06 5 9.839E-08 2.291E-10 1.660E-09 1.995E-08 1.445E-07 4.365E-07 7.5 1.554E-08 8.913E-12 1.000E-10 1.905E-09 1.950E-08 6.91 BE-08 10 3.796E-09 6.607E-13 1.072E-11 3.020E-10 4.074E-09 1.660E-08 20 9.133E-11 5.129E-16 2.344E-14 1.950E-12 5.754E-11 3.467E-10 14 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.2.2-2e: Annual Frequency of Exceedance Mean and Fractile Base Rock Seismic Hazard Curves for 5% Damped 2.5 Hz SA at Columbia Generating Station (PNNL, 2014) Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile SA [g] AFE AFE AFE AFE AFE AFE 0.0001 9.452E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.0005 8.962E-02 5.888E-02 6.761 E-02 8.318E-02 1.072E-01 1.380E-01 0.001 8.011 E-02 5.370E-02 6.166E-02 7.586E-02 9.550E-02 1.175E-01 0.005 3.739E-02 2.239E-02 2.754E-02 3.631 E-02 4.786E-02 5.623E-02 0.01 2.075E-02 1.175E-02 1.445E-02 1.995E-02 2.692E-02 3.311 E-02 0.02 1.015E-02 5.129E-03 6.607E-03 9.550E-03 1.349E-02 1.698E-02 0.05 3.348E-03 1.380E-03 1.905E-03 3.090E-03 4.786E-03 6.31 OE-03 0.1 1.247E-03 4.571 E-04 6.457E-04 1.096E-03 1.820E-03 2.512E-03 0.2 3.91 SE-04 1.175E-04 1.820E-04 3.311 E-04 6.026E-04 8.511 E-04 0.3 1.778E-04 4.365E-05 7.244E-05 1.445E-04 2.818E-04 4.169E-04 0.5 5.624E-05 9.333E-06 1.738E-05 4.169E-05 9.333E-05 1.514E-04 0.75 1.946E-05 2.089E-06 4.571 E-06 1.288E-05 3.311 E-05 5.888E-05 1 8.381 E-06 6.31 OE-07 1.514E-06 5.012E-06 1.445E-05 2.754E-05 1.5 2.225E-06 8.913E-08 2.570E-07 1.096E-06 3.802E-06 8.128E-06 2 7.827E-07 1.820E-08 6.310E-08 3.236E-07 1.31 SE-06 3.020E-06 3 1.545E-07 1.445E-09 6.607E-09 4.677E-08 2.455E-07 6.457E-07 5 1.561 E-08 3.236E-11 2.344E-10 2.818E-09 2.188E-08 6.918E-08 7.5 2.091 E-09 9.120E-13 1.072E-11 2.188E-10 2.455E-09 9.333E-09 10 4.538E-10 5.248E-14 9.333E-13 2.951 E-11 4.467E-10 1.950E-09 20 8.102E-12 1.862E-17 1.023E-15 1.230E-13 4.365E-12 3.020E-11 15 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.2.2-2f: Annual Frequency of Exceedance Mean and Fractile Base Rock Seismic Hazard Curves for 5% Damped 1 Hz SA at Columbia Generating Station (PNNL, 2014) Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile SA [g] AFE AFE AFE AFE AFE AFE 0.00001 9.457E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.00005 9.445E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.0001 9.366E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.514E-01 0.0005 7.614E-02 5.012E-02 5.754E-02 7.244E-02 9.333E-02 1.148E-01 0.001 5.808E-02 3.715E-02 4.365E-02 5.623E-02 7.244E-02 8.71 OE-02 0.003 2.844E-02 1.698E-02 2.042E-02 2.754E-02 3.631 E-02 4.365E-02 0.005 1.809E-02 1.047E-02 1.288E-02 1.738E-02 2.344E-02 2.884E-02 0.01 8.721 E-03 4.571 E-03 5.754E-03 8.318E-03 1.148E-02 1.445E-02 0.02 3.754E-03 1.585E-03 2.138E-03 3.467E-03 5.370E-03 6.918E-03 0.03 2.159E-03 7.943E-04 1.096E-03 1.905E-03 3.236E-03 4.467E-03 0.05 9.827E-04 3.236E-04 4.571 E-04 8.128E-04 1.514E-03 2.188E-03 0.1 2.712E-04 7.586E-05 1.175E-04 2.188E-04 4.169E-04 6.31 OE-04 0.2 5.472E-05 1.072E-05 1.905E-05 4.266E-05 8.913E-05 1.413E-04 0.3 1.823E-05 2.512E-06 5.012E-06 1.288E-05 3.090E-05 5.129E-05 0.5 3.758E-06 2.754E-07 6.761 E-07 2.239E-06 6.457E-06 1.230E-05 0.75 8.990E-07 3.388E-08 1.023E-07 4.365E-07 1.549E-06 3.311 E-06 1 2.938E-07 6.31 OE-09 2.239E-08 1.175E-07 4.898E-07 1.148E-06 2 1.377E-08 4.786E-11 2.884E-10 2.884E-09 1.995E-08 6.026E-08 5 1.672E-10 2.951E-14 4.467E-13 1.202E-11 1.660E-10 7.244E-10 10 7.121E-12 9.120E-17 3.090E-15 2.042E-13 4.898E-12 2.754E-11 16 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.2.2-2g: Annual Frequency of Exceedance Mean and Fractile Base Rock Seismic Hazard Curves for 5% Damped 0.55 Hz SA at Columbia Generating Station (PNNL, 2014) Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile SA [g] AFE AFE AFE AFE AFE AFE 0.00001 9.456E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.00005 9.228E-02 6.026E-02 6.918E-02 8.511 E-02 1.096E-01 1.479E-01 0.0001 8.577E-02 5.623E-02 6.457E-02 8.128E-02 1.023E-01 1.31 SE-01 0.0005 4.813E-02 2.951 E-02 3.548E-02 4.571 E-02 6.026E-02 7.413E-02 0.001 3.171 E-02 1.905E-02 2.291 E-02 3.020E-02 3.981 E-02 4.898E-02 0.003 1.376E-02 8.128E-03 9.772E-03 1.318E-02 1.778E-02 2.138E-02 0.005 8.460E-03 4.677E-03 5.888E-03 8.128E-03 1.096E-02 1.349E-02 0.01 3.935E-03 1.698E-03 2.291 E-03 3.631 E-03 5.623E-03 7.079E-03 0.02 1.569E-03 4.898E-04 6.918E-04 1.288E-03 2.512E-03 3.631 E-03 0.03 8.156E-04 2.188E-04 3.162E-04 6.026E-04 1.318E-03 2.089E-03 0.05 2.997E-04 6.607E-05 1.023E-04 2.089E-04 4.786E-04 8.511 E-04 0.1 5.295E-05 8.128E-06 1.479E-05 3.548E-05 8.318E-05 1.549E-04 0.2 5.984E-06 4.677E-07 1.122E-06 3.548E-06 1.023E-05 1.950E-05 0.3 1.357E-06 5.888E-08 1.698E-07 6.918E-07 2.344E-06 4.898E-06 0.5 1.661 E-07 2.692E-09 1.047E-08 6.026E-08 2.81 BE-07 6.761 E-07 0.75 2.590E-08 1.479E-10 7.762E-10 6.607E-09 3.981 E-08 1.122E-07 1 6.247E-09 1.445E-11 1.000E-10 1.148E-09 8.71 OE-09 2.818E-08 2 1.422E-10 1.995E-14 3.162E-13 9.120E-12 1.349E-10 6.166E-10 5 5.984E-13 5.623E-19 4.898E-17 6.166E-15 2.692E-13 1.995E-12 10 1.125E-14 O.OOOE+OO O.OOOE+OO 2.188E-17 2.512E-15 2.754E-14 17 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.2.2-3: Acronyms for Seismic Sources and Indication of Those Sources Contributing more than 5% of the Total 1and/or10 Hz Seismic Hazard for Mean Annual Frequencies of Exceedance Between 10*4 and 10*5 Acronym Seismic Source Name >5% Contribution* Subduction Sources csz Cascadia Subduction Zone (interface) 2 JDF Juan de Fuca lntraslab source Crustal Area Sources YFTB Yakima Fold and Thrust Belt Backciround 1 Zone B Mid-C Study Zone B ZoneC Mid-C Study Zone C Zone D Zone D Crustal Fault Sources AF Arlington ARH Ahtanum -Rattlesnake Hills 10 CH Columbia Hills CM Cleman Mountain FH Frenchman Hills HHH Horse Heaven Hills 7 HR Horn Rapids Fault 6 LB Luna Butte LF Laurel MF Maupin MR Manastash Ridge RAW Rattles of the Rattlesnake-Wallula Alicinment 8 RM Rattlesnake Mountain 3 SB Selah Butte SFZ Seattle Fault SM Saddle Mountain 9 TR Toppenish Ridge UR Umtanum Ridge 4 WF Wallula Fault YR Yakima Ridoe 5 Note: Modified after Table 10.13 in PNNL (2014) "Number represents approximate order of contribution to the total hazard; lack of a number indicates that the source contributed <5% to the total hazard 18 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 1.E-02 I 1.E-03 I r I I I I I I CD I u I c 1.E-04 "' ""C I I CD I CD I u I 25 Hz )( I LU I 10 Hz 0 I > 1.E-05 u PGA c I I CD I ::::s I -SHz I C" I CD ... I 2.5 Hz LL. -I "' -lHz ::::s 1.E-06 c I c I -0.5 Hz I < I I I I 1.E-07 I I I I I I I 1.E-08 I I L _____________ 0.01 0.1 1 10 100 Spectral Acceleration (g) Figure 2.2.2-1: Mean Base Rock Hazard Curves for Oscillator Frequencies of 0.5, 1, 2.5, 5, 10, 25 and 100 Hz at Columbia Generating Station (PNNL, 2014) at 5% Spectral Damping 19 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Site c (CGS): 10*4 MAFE: T:0.1 sec SA Site c (CGS): 104 MAFE: T:1.0 sec SA 20* (.:") Site C (CGS): 10*5 MAFE: T:0.1 sec SA Site C (CGS): 10*5 MAFE: T:1.0 sec SA . . 10<:, tf) Figure 2.2.2-2: Deaggregation Histogram Showing Magnitude-Distance Contributions to the Total Mean Hazard at Site C for 5% Damped 10 Hz (0.1 s) (left column) and 1 Hz (1.0 s) (right column) Spectral Accelerations at MAFEs of 10*4 (top row) and 10*5 (bottom row) (Source: Figures 10.41and10.42 in PNNL, 2014) 20 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure SiteC 10*1 G) (,) c 10*<' cu 'ti G) G) (,) 10*3 )( w 0 10-4 c G) :I tT G) 10*5 .... u. cu :I 10*6 c c <( 10*7 10*4 10*3 10*2 10*1 100 101 T0.1 sec Spectral Acceleration [g] -meanTOT *-***--* csz .,,.

• JDF ....... &-*** ZONEB ........ & ........ ZONEC *--*& --YFTB ZONED --AF --ARH CH --CM --FH HHH --HR LB --LF MF --MR --RAW RM SB --SFZ --SM --TR UR --YR WF Figure 2.2.2-3. Comparison Between the Mean Hazard Curves at Columbia Generating Station (Site C) Obtained for Each Individual Source: subduction sources are shown by dotted star curves; crustal sources by dotted circle curves; and fault sources by solid curves for 5% damped 10 Hz (0.1 s) SA. Acronyms used in figures are listed in Table 2.2.2-3 (Source: Figure 10.44 in PNNL, 2014) 21 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure SiteC 10-1 a,, (..) c: cu a,, a,, (..) 10-3 >< w '-0 10*4 c: a,, ::::I C"' G,) 10-S ... u. -cu ::::I 10*6 c: c: <( 10-7 10-8 ............... .......... ............... 10-5 10-4 10-3 10-2 10-1 10° T1.0sec Spectral Acceleration [g] -meanTOT ***-***-** csz JDF ....... & ....... Z 0 NEB ......... a ......... ZONEC ...... & ....... YFTB ZONED --AF --ARH CH --CM --FH HHH --HR LB --LF MF --MR --RAW RM SB --SFZ --SM --TR UR --YR WF Figure 2.2.2-4. Comparison Between the Mean Hazard Curves at Columbia Generating Station (Site C) Obtained for Each Individual Source: subduction sources are shown by dotted star curves; crustal sources by dotted circle curves; and fault sources by solid curves for 5% damped 1 Hz (1.0 s) PSA. Acronyms used in figures are listed in Table 2.2.2-3 (Source: Figure 10.44 in PNNL, 2014) 22 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 2.3 Site Response Evaluation Following the guidance contained in Seismic Enclosure 1 of the NRG (2012a) 50.54(f) Request for Information and in the SPID (EPRI, 2013a) for nuclear power plant sites that are not located on hard rock (defined as 9,200 ft/s or 2,830 m/s), a site response analysis was performed for CGS. 2.3.1 Description of Subsurface Material Soils beneath the CGS site extend down to approximately 525 ft depth. The top soil layer consists of about 45 ft thickness of Pasco Gravel, a Quaternary deposit made up of glaciofluvial sediments consisting of loose to medium dense sand with scattered gravel. These soils are underlain by the Pliocene-age Ringold Formation. The Ringold comprises (1) the Middle Member, a very dense sandy gravel with interbedded sandy and silty layers, down to 250 ft depth, and (2) the Lower Member, from 250 ft to 525 ft depth, consisting of very dense interbedded layers of sandy gravel, silt and soft sandstone with some conglomerate present at the base of the layer. Several hundred feet of the Ringold Formation materials at the site were removed during Pleistocene floods. The overlying Pasco Gravel was deposited over the eroded surface of the Ringold Formation materials and has not been subjected to significant past loading. The groundwater table is in the Middle Ringold Member at a depth of about 62 ft. The rock below 525 ft consists of the Saddle Mountains Basalt (SMB) down to about 1300 ft depth, underlain by the Wanapum Basalt, Grande Ronde Basalt, and the lmnaha Basalt. The Wanapum Basalt is counted as the start of basement rock, with a shear wave velocity (Vs) of over 9,200 ft/s. There are four basalt members within the SMB that range from about 110 ft to 215 ft in thickness, each underlain by a sedimentary interbed consisting mainly of sandstone and claystone, and ranging in thickness from about 15 ft to 70 ft. The collective interbeds are called the Ellensburg Formation. The deepest boring at the CGS plant extended to about 850 ft depth, to just below the bottom of the second sedimentary interbed (Selah lnterbed) of the SMB. The stratigraphy below the Selah lnterbed was inferred from four borings not drilled tor CGS but within 2.6 to 3.4 miles of the site. The SMB stratigraphy at CGS (from the 850-ft deep boring at the site and the four borings beyond the site) is compared in Table 2.3.1-1 with the stratigraphy at the Waste Treatment Plant (WTP) about 10 miles northwest of CGS. 23 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.1-1: Comparison of Estimated SMB Layer Thicknesses at CGS and WTP Stratum Thickness (ft) CGS WTP Elephant Mountain Basalt 130(1) 110 Rattlesnake Ridge lnterbed 25(1) 45 Pomona Basalt 160(l) 200 Selah lnterbed 15t1J 20 Esquatzel Basalt 11Q(LJ 90 Cold Creek lnterbed 44(Z) 95 Umatilla Basalt 214(2) 150 Mabton lnterbed 67lLJ 100 (1) From the 850-ft deep CGS site boring (2) From the four borings located 2.6 miles to 3.4 miles from the CGS site Table 2.3.1-1 shows that all of the basalt members and sedimentary interbeds of the SMB present at WTP are also present at the CGS site. The total thicknesses of the SMB at each site are comparable (765 ft at CGS and 810 ft at WTP) although the elevations of the top of the SMB are different (El. -85 ft at CGS and El. 290 ft at WTP). The thicknesses of each basalt member are comparable, with generally more variation in the interbed thicknesses. It is noted that at WTP, the Umatilla Member consists of the upper Sillusi flow and the underlying Umatilla flow. At CGS, the Umatilla Member is assumed to consist only of the Umatilla flow (PNNL, 2014). The 850-ft deep boring at CGS did not include measurements of Vs or other geotechnical parameters. Actual Vs measurements at CGS were taken to 105 ft depth. Vs measurements were taken down to close to the bottom of the Ringold Formation at the nearby WNP-1 (1 mile southeast of the CGS site) and WNP-4 (3/4 mile northeast of the CGS site) sites, and can be used for the CGS site. (The WNP-1 and WNP-4 nuclear plants were started but not completed.) However, no measurements of Vs or other geotechnical parameters were made in the SMB at CGS, WNP-1 or WNP-4. Extensive Vs and unit weight (y) measurements were performed down to about 1,450-ft depth at WTP, i.e., into the Wanapum Basalt basement rock. Given the level of agreement between the SMB stratigraphy at the CGS and WTP, it is reasonable to apply the WTP SMB Vs and y values to the CGS site. Table 2.3.1-2 provides a brief description of the subsurface materials in terms of the geologic units and layer thicknesses. This table includes best estimate values of Vs, compressive wave velocity (Vp), v and Poisson's ratio. As discussed in Section 2.3.2, both down-hole and P-S suspension logging measurements were used to measure Vs at WTP. The Vs values in the SMB in Table 2.3.1-2 are the mean values from the down-hole measurements since they are 24 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure considered to be more representative. The P-S suspension logging Vs measurements are presented and discussed in Section 2.3.2. Table 2.3.1-2: Geologic Profile and Estimated Layer Thicknesses for CGS Depth Soil/Rock Density Vs Vp Poisson's Range Description (pcf) (fVs) (ft/s) Ratio (ft} 0 SSE control point ------------0-6 Pasco Gravel 105 520 1,080 0.35 6-13 Pasco Gravel 105 700 1,460 0.35 13-21 Pasco Gravel 105 840 1,750 0.35 21-45 Pasco Gravel 105 900 1,875 0.35 45-56 Middle Ringold 141 1,320 2,620 0.33 56-85 Middle Ringold 145 2,040 4,805 0.39 85-250 Middle Ringold 145 4,740 10,135 0.36 250-300 Lower Ringold 145 2,300 4,920 0.36 300-325 Lower Ringold 145 3,260 6,970 0.36 325-525 Lower Ringold 145 2,200 4,705 0.36 525-655 Elephant Mountain Basalt 175 7,575 15,950 0.35 (SMB) 655-680 Rattlesnake Ridge lnterbed 118 2,750 7,520 0.42 680-840 Pomona Basalt (SMB) 175 8,300 16, 120 0.32 840-855 Selah lnterbed 133 2,945 7,400 0.41 855-965 Esquatzel Basalt (SMB) 171 8,285 17, 175 0.35 965-1009 Cold Creek lnterbed 121 2,700 6,560 0.40 1009-1223 Umatilla Basalt (SMB) 166 8,360 17,270 0.35 1223-1290 Mabton lnterbed 127 2,720 7,445 0.42 1290+ Basement Rock 176 9,840 20,870 0.36 There are transition zones called flow tops between the interbeds and the SMB basalt members, ranging in thickness from approximately 20 ft above the Elephant Mountain Basalt to 31 ft above the Pomona Basalt. These flow tops consist of breccia, vesicular basalt, or a mixture of sedimentary clay and basalt breccia. Vs increases through these flow tops from the interbed Vs to the basalt Vs. The thickness of the flow tops is included in the depth range for each of the basalt members listed in Table 2.3.1-2. There is also a thin flow top at the top of the underlying Wanapum Basalt. The flow top Vs values (and corresponding flow top densities) are not included in Table 2.3.1-2, but are modeled in the seismic response analysis. As noted earlier in this section, the Wanapum Basalt below the SMB is counted as the start of basement rock, with a shear wave velocity (Vs) of over 9,200 ft/s. The basement rock is modeled 25 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure with an assigned Vs of 9,840 ftls {3,000 m/s) in the seismic response analysis and this is the value shown in Table 2.3.1-2. 2.3.2 Development of Base Case Profiles and Nonlinear Material Properties The approach taken in developing base case profiles and nonlinear material properties for the upper 525 ft of soil materials at CGS is substantially different from that for the underlying basalt members and interbeds. Soil Materials to 525 Ft Depth Available Data There are four sources of data available to create the base-case soil Vs profile: 1. The cross-hole Vs profile from CGS (originally called WNP-2) to a depth of 105 ft. 2. Cross-hole and down-hole Vs results from nearby WNP-1 and WNP-4. 3. Seismic refraction survey interpretation in the upper materials at CGS. 4. Indirect means of determining shear wave variation using SPT N-value data for the shallower deposits. Figure 2.3.2-1 shows Vs plotted versus depth for data sources 1 and 2. These plotted results do not show the actual measured values, but rather averaged results over specified depth intervals. There is generally good agreement between the results in the figure. The Vs measurements in the Middle Member of the Ringold Formation between about 100 ft to 250 ft depth range from around 4,500 ft/s to 5,000 ft/s. These values are considerably higher than would be expected in what is generally regarded as a soil formation. However, there is strong supporting evidence for these higher values:
• The results at CGS increased to around 4,200 ft/s towards the bottom of the boring.
• Similar measurements were obtained at WNP-1 and WNP-4 using both cross-hole and down-hole methods, which are quite different techniques that use entirely different instruments.
• The Vs measurements below 250-ft depth in the Lower Member of the Ringold Formation at WTP-1 and WTP-4 drop back into the expected Vs range of about 2,000 to 2,500 tVs, again suggesting that the equipment was providing accurate measurements. Three shallow seismic refraction survey lines (data source 3) were run at CGS. Vs values were obtained from the Vp measurements using the Poisson's ratio values given in Table 2.3.1-2. The measured cross-hole and derived seismic refraction Vs values down to 105 ft depth were in 26 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure good agreement, including a jump to between 4,350 to 4.490 ft/s from seismic refraction. compared to 4,200 fVs noted above for the same depth interval from the cross-hole. There are numerous relationships developed in the literature to determine Vs using standard penetration test (SPT) N-values. For the CGS site, boring logs were available from 29 borings with SPT N-values taken at 2 .5-ft to 10-ft intervals (data source 4). Refusal ( N = 100 blows/ft) was reached typically at about 45 ft depth, i.e., at the bottom of the Pasco Gravel. Analysis of the standard deviation of these data using the natural log of Vs (i.e., o1nvs) showed that for the Pasco Gravel, the average 01nvs was about 0.25. Vs measurements at WNP-1 extend to about 435 ft depth and at WNP-4 to about 400 ft depth. The bottom of the Ringold Formation is at about 437 ft depth at WNP-1 and at about 406 ft depth at WNP-4. Thus it can be concluded that the Vs measurements at these two sites extend to within a few feet of the bottom of the Ringold. It is reasonable to conclude that the best fitting Vs value of just over 2,000 ft/sin the lower portions of WNP-1 and WNP-4 (Figure 2.3.2-1) extends also to the bottom of the Ringold at CGS at 525 ft depth. Base Case Profiles EPRI (2013a) (SPID), Appendix B-3.2 indicates that for sites with very limited Vs data, the estimate for epistemic uncertainty is to be taken as a1nvs = 0.35. In this situation, there will be three base case Vs profiles, the best estimate or base case (Vee), the lower range (VLR) and the upper range (VuR). Each of these Vs profiles is randomized and a weight given to each. EPRI (2013a) recommends that VLR is the 101h percentile and VuR is the 901h percentile. with V8c being the 501h percentile. According to EPRI (2013a), the 101h and 901h percentiles correspond to a profile scale factor of 1.28 01nvs* This results in VLR = 0.639 Vee and VuR = 1.565 Vee. This is a much greater variation in Vs than obtained from the measured Vs values shown in Figure 2.3.2-1. A more realistic approach is to accept that there is not a great deal of epistemic uncertainty at CGS, given the good agreement between the CGS, WNP-1 and WNP-4 Vs results, and the good agreement using cross-hole, down-hole and seismic refraction techniques., there is no distinct epistemic uncertainty on the shear-wave velocity data. Epistemic uncertainty represents the lack of knowledge about the Vs profile of the CGS site. Given the Vs profile shown in Figure 2.3.2-1, it is probable that an additional measured Vs profile would fall close to the V sc profile derived from the Figure 2.3.2-1 results. Thus, the Vee profile derived from Figure 2.3.2-1 will be used, and the aleatory variability {i.e., the inherent variability found at any site) will be accommodated by assigning standard deviation values to the Vsc profile to be used in the randomization process. The randomization process (Section 2.3.3) typically considers up to 2 standard deviations from the base case. As noted before, since seismic properties are typically considered to be log-normally distributed, 01nvs will be used, i.e., the log normal standard 27 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure deviation. To summarize, a single base case profile (Vsc) will be used, and the variability in the randomization process will be accounted for by using simulated profiles. Table 2.3.2-1 shows the Vsc values computed from the Figure 2.3.2-1 results down to 525 ft depth. Values of 01nvs that are used to obtain Vus and VLs are discussed next. For aleatory variability, EPRI (2013a) Appendix 8-4.1 recommends using 01nvs = 0.25 down to 15 m (49 ft (15 m) depth and a1nvs = 0.15 below that. As noted above, the average 0'1nvs based on correlation with N-value for the top approximately 45 ft is about 0.25, in agreement with the EPRI (2013a) recommendation. The 01nvs = 0.25 is extended down to 56 ft depth, the nearest interval bottom to 49 ft. Between 300 ft and 325 ft depth, (El. 140 ft to El. 115 ft) the WNP-1 Vs is about 2,300 ft/s while the WNP-4 Vs is about 4,300 ft/s, and V8c is 3,260 ft/s. To account for this larger variation, a1nvs will be assigned a value of 0.3 in this range. Below 325 ft depth (El. 115 ft), although there are down-hole data for WNP-1 and WNP-4, these do not extend down to El. -85 ft (bottom of Ringold at CGS). Thus, there is a somewhat higher level of uncertainty in this range, and so 0'1nvs is increased to 0.2. Table 2.3.2-1 shows the recommended Vs with the corresponding 0'1nvs values. The Vee, VLs and Vue profiles, which respectively represent the 1 o*h and 901h percentiles, are plotted in Figure 2.3.2-2. Note that the values from Figure 2.3.2-1 for CGS (WNP-2). WNP-1 and WNP-4 hole CH and down-hole DH) are also included in Figure 2.3.2-2. Rock Below 525 Ft Depth The rock beneath the bottom of the Ringold Formation is described in Section 2.3.1. It consists of the Saddle Mountains Basalt (SMB) down to about 1300 ft depth. underlain by the Wanapum Basalt which is counted as the start of basement rock, with Vs of over 9,200 ft/s. The stratigraphy of the rock at CGS is taken from a deep boring at the site down to about 850 ft depth and from four borings outside but relatively close to the site down to 1,300 ft depth. However, no Vs measurements were made in the rock in any of these five borings. As described in Section 2.3.1, the Vs values for the rock at CGS were obtained from extensive measurements made in the rock at WTP. Both down-hole and P-S suspension logging Vs measurements were made down to about 1,400 ft depth at WTP. terminating in the Rosalia Flow of the Wanapum Basalt. The down-hole measurements (Profile C1) were judged to be more representative since it was determined that the P-S suspension logging measurements (Profile C2) would probably have required higher frequency signals to accurately measure the hard basalt (PNNL, 2014). It was concluded that the down-hole measurements could be considered to be twice as reliable as the P-S suspension logging measurements in this environment, leading to the assignment of relative 28 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure weights of 2:1, i.e., a weight of 2 to Vs Profile C1 and a weight of 1 to Vs Profile C2 (PNNL, 2014). The Vsc values versus depth and elevation for Profile C1 and Profile C2 are given in Table 2.3.2-2. For variation of each Vsc profile, <11nvs of 0.1 is used for each basalt member, and 01nvs of 0.2 is used for each interbed (PNNL, 2014). The Vee. VLe and Vue profiles are plotted on Figure 2.3.2-3 for both the rock and the soil with VL8and Vue representing the 10th and goth percentiles. As noted in Section 2.3.1, there are transition zones called flow tops between the interbeds and the SMB basalt members, ranging in thickness from approximately 20 ft above the Elephant Mountain Basalt to 31 ft above the Pomona Basalt. There is also a thin flow top at the top of the underlying Wanapum Basalt. The flow top Vs values (and corresponding flow top densities) are not included in Table 2.3.2-2 or Figure 2.3.2-3, but are modeled in the seismic response analysis. The flow top Vs values and corresponding flow top densities are shown in Figure 2.3.2-4 (from PNNL.1. 2014). Table 2.3.2-1: Base Case Shear-Wave Velocity (V8c) for the Soil Profile Material Depth {ft) Top El. (ft) Vs (fVs} OtnVs Sand 0-6 440 520 0.25 Sand 6-13 434 700 0.25 Sand 13*21 427 840 0.25 Sand 21*45 419 900 0.25 Middle Ringold 45-56 395 1,320 0.25 Middle Ringold 56-85 384 2,040 0.15 Middle Ringold 85-250 355 4,740 0.15 Lower Ringold 250-300 190 2,300 0.15 Lower Ringold 300-325 140 3,260 0.30 Lower Ringold 325-525 115 2,200 0.20 29 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.2-2: Base Case Shear-Wave Velocity (V8c) Rock Profiles C1 and C2 Material Depth Top El. Vsc C1 Vsc C2 O'tnVs (ft) {ft) {ftls) {ftls) Elephant Mtn Basalt (SMB) 525-655 -85 7,575 9,550 0.1 Rattlesnake Ridge lnterbed 655-680 -215 2,750 2,730 0.2 Pomona Basalt (SMB) 680-840 -240 8,300 10,235 0.1 Selah lnterbed 840-855 -400 2,945 3,190 0.2 Esquatzel Basalt (SMB) 855-965 -415 8,285 9,690 0.1 Cold Creek lnterbed 965-1009 -525 2,700 2,490 0.2 Umatilla Basalt (SMB) 1009-1223 -569 8,360 9,420 0.1 Mabton lnterbed 1223-1290 -783 2,720 2,565 0.2 Basement Rock 1290+ -850 9,840 9,840 -30 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure -£ Q ... c 1000 50 100 150 200 250 300 350 400 Shear Wave Velocity. ft/sec 2000 3000 4000 WNP*2 r I I I WNP-4 I I I I I I WNP-1 I I I I I I I I I l I r-*.....------__....._ __ __, I I I I I I I : WNP-4 L------------, l I I I I I r--L--------I I I WNM 6000 __ _._ _____ ..._ ____ _.. __________________ ..... EXPLANATION ------Downhole menurtment ----Cros1hole meuuremen1 Figure 2.3.2-1: Vs Values in Soil from CGS (WNP-2), WNP-1 and WNP-4 (Source: FSAR Figure 361.017-1; EN, 2013b) 31 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 450 350 250 g i:: 0 i 150 > a> w 50 150 0 I Sand I GS El. 440ft . -* I -I
• I I : : I .l --., I I I ...... :-* . I . I __ J _________________ . '* .
• I .... -----. ! . I . ' . *---. . . . . I I .

. Middle Ringold . . . . . . . . ------. . I I . I . I . . I . I . I I I . : ,*-------------------------. *I . :1 . __ I I . !1 . Lower Ringold . I .. . . I I . I . . ----.. --. . . -----WNP-1 CH . . . . ----*WNP-2CH . . . . WNP-4CH . . . WNP-1 DH . . . . -WNP-4DH . . . -Base Case . . . . * * * *

• Lower Bound . . . ---Upper Bound .

. . . . --. I Saddle Mtn Basalt 1000 2000 3000 4000 5000 6000 7000 Vs (fps) Figure 2.3.2-2: Base Case, Lower Bound and Upper Bound Vs in Top 525 Ft 32 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Developement of Base Case Profiles Shear wave Velocity (fps) 0 2000 4000 6000 8000 10000 12000 14000 0 = -.s CL al 100 200 300 400 500 600 Q 700 800 900 1,000 1,100 1,200 1,300 .. --L .1 I:_ * * . . .. . .. II . -II . . . . I . I . I I . I . I I . I ' . I . I . I . Soil, Ba5e Case Soil, Lower-bound Soil, Upper-bound -Rock Profile 1, Base Case -* -Rock Profile 1, Lower-bound ....... Rock Profile 1, Upper-bound -Rock Profile 2, Base Case -* -Rock Profile 2, Lower-bound ******* Rock Profile 2, Upper-bound I I . I ..... I I I . . ... I : : I .... ..... ' ***. I lo I I ...... Figure 2.3.2-3: Base Case, Lower Bound and Upper Bound Vs for Rock Profiles C1 & C2 33 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 0 100 -E -a. ct> 0 200 . *:,.*:I 300 0 0 L---I I I I 100 --, I I I 200 *,,* 300 I I F,,-.:,.:. *,-: :-* . Sile c (profile 1) Site C (profile 2) .._ l r 1000 2000 Vs (m/s) 3000 4000 1.8 2 2 2 2.4 2.6 2.8 r (g/cmC*) Figure 2.3.2*4: Rock Profiles C1 & C2 Showing Flow Top Shear-Wave Velocities and Densities (PNNL, 2014) 34 of 136 3 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 2.3.2.1 Shear Modulus and Damping Ratio Curves 2.3.2.1.1 Shear Modulus and Damping for Soil Materials to 525 Ft Depth For curves of soil shear modulus reduction (G/GMAx) and damping ratio (D) versus cyclic shear strain, EPRI (2013a) (SPID) recommends using the EPRI and Peninsular curves for cohesionless soils defined by depth, giving an equal weight to each. Since the CGS soils are classified as mainly sand in the upper 45 ft, and the Ringold Formation from 45 ft to 525 ft is mainly sandy gravel, these curves are appropriate. Figure B-8 of EPRI (2013a) shows the EPRI curves, giving curves from 0-20 ft depth all the way down to 500-1,000 ft depth (from EPRI, 1993). This figure is included here as Figure 2.3.2.1-1. The tabulated values scaled from these curves are given in Table 2.3.2.1-1 for G/GMAx and Table 2.3.2.1-2 for D. The Peninsular curves (from Silva et al, 1997) for G/GMAxand D versus shear strain for depth of 0 to 50 ft and depth of 50 to 500 ft are given in Figure 2.3.2.1-2. The tabulated values of the Peninsular curves are given in Table 2.3.2.1-3 for G/GMAx and D. Comparison of the values in Tables 2.3.2.1-1, 2.3.2.1-2 and 2.3.2.1-3 shows that for G/GMAx and D, the Peninsular curve for depth of 0 to 50 ft is very similar to the EPRI curve for depth of 50 to120 ft, and the Peninsular curve for depth of 50 to 500 ft is very similar to the EPRI curve for depth of 500 to 1,000 ft. This similarity is noted in EPRI (2013a). As noted in EPRI (2013a), D values are limited to 15% in the soil column analysis. Table 2.3.2.1-4 shows the applicable curves from Tables 2.3.2.1-1, 2.3.2.1-2 and 2.3.2.1-3 for use in each depth range. The uncertainty of each G/GMAx and D versus shear strain curve is computed following the methodology outlined in EPRI (2013a) and further explained in PNNL (2014). At a shear strain of 0.03%, the variation of G/GMAxand Dis treated as a log normal distribution with the natural log of the standard deviation cr1n = 0.15 for G/GMAX and cr1n = 0.30 for D. For D, cr1n is independent of shear strain. For G/GMAx, cr1n is varied with shear strain to taper the variation at small strains such that the non-linear curves converge to 1 at small strains. 2.3.2.1.2 Shear Modulus and Damping for Rock below 525 Ft Depth The basalt members of the Saddle Mountains Basalt behave as elastic materials with G/GMAx = 1 over the strain range of interest. Damping of the basalt members is independent of strain, and was estimated as a function of the inverse of Vs (PNNL, 2014). Damping values ranged from a high of 1.03% in Profile 1 for the uppermost flow top of the Elephant Mountain Basalt to 0.46% in Profile 2 for the Pomona Basalt, with a median of about 0.75% (Profile 1) and about 0.65% (Profile 2). 35 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Several non-linear models were considered for establishing G/GMAx and D for the Saddle Mountains Basalt interbeds. The model proposed by Darendeli (2001) was considered viable for the interbeds and was adopted because it offers more flexibility and accounts for confining stress dependence which is important for the depths at which the interbeds are located (PNNL. 2014). The Darendeli (2001) equations for damping have two separate terms. The first term is independent of strain and controls low-strain damping. As with the basalt members, this strain term was estimated for the interbeds as a function of the inverse of Vs (PNNL, 2014). The second term represents hysteretic damping and is strain-dependent. This term has very low values at low strains but is the dominant term at high strains. The damping curves for the interbeds are constructed as the sum of the low-strain damping (function of the inverse of Vs) and the hysteretic damping term (PNNL, 2014). Examination of the PNNL (2014) interbed damping curves indicates that the low-strain damping term is reduced with increasing strain, and only the hysteretic portion is used at shear strains above about 0.05%. All four interbeds have very large confining stresses, with the deepest interbed (Mabton) having the most and the shallowest interbed (Rattlesnake Ridge) having the least. This results in the Mabton interbed having slightly less G/GMAx reduction with increasing shear strain than the Rattlesnake Ridge interbed. Similarly, the Mabton interbed has slightly less damping with increasing shear strain than the Rattlesnake Ridge interbed. The Cold Creek interbed (shallower than the Mabton and deeper than the Rattlesnake Ridge) has G/GMAx and D curves that are between (but very close to) those of the Mabton and Rattlesnake Ridge interbeds. These Cold Creek curves will be used to illustrate the G/GMAx and D values for the interbeds. The Cold Creek interbed curves (derived from PNNL, 2014) for G/GMAxand D versus shear strain are shown in Figure 2.3.2.1-3. The tabulated values of these curves are given in Table 2.3.2.1-5 for G/GMAx and D. As noted in EPRI (2013a), D values are limited to 15% in the rock column analysis. The uncertainty of G/GMAx and D for the interbeds is treated the same way as for the overlying soils, as described in Section 2.3.2. 1 .1. 36 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.2.1-1: Shear-Modulus Reduction Curves for the EPRI (1993) Model G/GMAX Shear Strain (%) 0-20 ft 20-50 ft 50-120 ft 120-250 ft 250-500 ft 500-1000 ft 0.0001 1.0 1.0 1.0 1.0 1.0 1.0 0.000316 1.0 1.0 1.0 1.0 1.0 1.0 0.001 0.99 0.995 0.995 0.995 1.0 1.0 0.00316 0.92 0.95 0.97 0.98 0.99 0.995 0.01 0.76 0.83 0.88 0.91 0.94 0.96 0.0316 0.50 0.60 0.70 0.75 0.80 0.86 0.1 0.28 0.36 0.44 0.50 0.57 0.65 0.316 0.125 0.18 0.23 0.28 0.33 0.40 1.0 0.05 0.075 0.10 0.13 0.16 0.20 Table 2.3.2.1-2: Damping Ratio Curves for the EPRI (1993) Model Damping Ratio (%)111 Shear Strain {%) 0-20 ft 20-50 ft 50-120 ft 120-250 ft 250-500 ft 500-1000 ft 0.0001 1.5 1.25 1.0 1.0 1.0 0.5 0.000316 1.5 1.25 1.0 1.0 1.0 0.5 0.001 2.0 1.5 1.25 1.0 1.0 0.5 0.00316 2.6 2.0 1.5 1.25 1.1 0.75 0.01 5.0 3.5 2.7 2.2 2.0 1.25 0.0316 9.5 7.5 5.7 4.2 3.6 2.5 0.1 15.1 12.5 10.3 8.75 7.3 5.1 0.316 22.0 19.0 16.5 14.5 12.8 10.2 1.0 27.5 24.7 22.6 20.8 19.0 16.2 (1) Damping is limited to 15% maximum in the soil column analysis. 37 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.2.1-3: The Shear-Modulus Reduction and Damping Ratio Curves for the Peninsular Range (Silva et al., 1997) model G/GMAX Damping Ratio (%)w Shear Strain (%) 0-50 ft 50-500 ft 0-50 ft 50-500 ft 0.0001 1.0 1.0 1.1 0.5 0.000316 1.0 1.0 1.1 0.5 0.001 1.0 1.0 1.3 0.5 0.00316 0.96 0.99 1.6 0.9 0.01 0.85 0.95 3.0 1.4 0.0316 0.67 0.84 5.5 2.6 0.1 0.43 0.64 10.3 5.5 0.316 0.22 0.40 16.5 10.3 1.0 0.09 0.20 22.8 16.5 ( 1) Dam ping is limited to 15% maxim um in the soil column analysis. Table 2.3.2.1-4: Selected G/Gmax and Damping Ratio Curves for Depths Above 525 ft Material Depth Top El. G/GMAx & D Curves111 (ft) {ft) EPRI Peninsular Sand 0-6 440 Sand 6-13 434 0-20 ft 0-50 ft Sand 13-21 427 Sand 21-45 419 Middle Ringold 45-56 395 20-50 ft Middle Ringold 56-85 384 50-120 ft Middle Ringold 85-250 355 120-250 ft 50-500 ft Lower Ringold 250-300 190 Lower Ringold 300-325 140 250-500 ft Lower Ringold 325-525 115 Saddle Mtn. Basalt . -85 (1) Analyses are performed using both the EPRI and Peninsular curves, with equal weighting for each. 38 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.2.1-5: Cold Creek lnterbed G/Gmax and Damping Ratio Versus Shear Strain G/GMAX Damping Ratio Shear Strain (%) (%fl 0.0001 1.0 1.8 0.000316 1.0 1.85 0.001 0.99 1.9 0.00316 0.97 2.0 0.01 0.90 2.8 0.0316 0.77 4.2 0.1 0.53 8.0 0.316 0.28 14.0 1.0 0.12 20.0 (1) Damping is limited to 15% maximum in the rock column analysis. 39 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure ';::::;'--...... ._ O.B ,..o.s 1,9 ...... 1,9 0.4 -.:* -20 ft --20-SC* ft 3D. 12Co ft --110 -2.50:* ft 0.1 250 -3C(* ft 3 DD -lCO:O:* f: D a.DOD 1 D.CO:*l rn -o-2att 25 --20-50 f: SQ* 12D :: :f;. --120 -2 50 ft -Ill 2.50 -.5 DD ft .: 15 Cir.. E 500 -lDDa ft IS Q 10 .5 -... .... ... ..... ... ' o.o.:. ' ' ' She-ar Strain(%) -... --.. ,-... i) O.DOOl 0.001 D.01 Shear Strain(%) .... ' ' ' D.l / ... .. ,,.. 0.1 .,., ' 1 , " / ,, , Figure 2.3.2.1-1: EPRI G/Gmax and Damping Ratio Curves (EPRI, 1993) 40 of 136 l RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure ......... .... ' ' ' ' ' ' ' ' ' ' ' ' " ' ' ' ' ..... ' 0 ______ ....._ ____ ....._ ____ ..__ ____ ..__ ____ ..__ ____ .....__ ____ ....._ __ ___, -4.0 -3.S -3.D -2. s -2. 0 -1.5 -1.0 -0.'5 o.o CCI ,...., N1 .1 LEGoiD r ---0-50 n N I 51-lO:C: ., .,., c:i ---£ N: v ' ui c: N c t. ID ,.... ,.... / ,,..,.... __ ..... / / / / / / / / / / / / /. / / O "------....._ ____ ....._ ____ ..__ ____ _._ ____ ..__ ____ ....__ ____ ....._ __ ___J -.:i.O -3.5 -3.D -2.S -2.0 -1. s -1. 0 -0. s 0. Cl log <Shedr Strain -MODULUS REDUCTJON AND DRMP!NS CURVE5 SOILS Figure 2.3.2.1-2: Peninsular G/Gmax and Damping Ratio Curves (Silva et al., 1997) 41 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 1 0.9 0.8 0.7 x 0.6 Ill o.s " C> 0.4 0.3 0.2 0.1 0 0.0001 20 18 16 .2 12 1ii Ci:: 10 *a. 8 E " c 6 4 2 0 0.0001 0.001 0.001 0.01 Shear Strain (%) -G/GMAX 0.01 Shear Strain (%) -Damping Ratio(%) 0.1 1 0.1 1 Figure 2.3.2.1-3: Cold Creek lnterbed G/Gmax and Damping Ratio Curves (PNNL, 2014) 42 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 2.3.2.2 Kappa The site attenuation parameter (Ko) at the CGS is dependent on the supra-basalt sediments, the SMB stack, and the input motion. The PNNL (2014) report documented an extensive study regarding the Ko contributions of the SMB stack and the input motion. In the study, the empirical estimates of the Ko were computed using two methods and recordings from 59 earthquakes recorded at 6 different sites around the Hanford site. The result of the study was the distributions of Ko at the reference condition (i.e., input motion horizon) and at the top of the SMB stack, shown in Figures 2.3.2.2-1 and 2.3.2.2-2, respectively. No explicit consideration of the contribution of the supra-basalt sediment to the total Ko was made. Instead, this contribution was based on the low strain damping from the assigned soil strain-dependent nonlinear curves. The site attenuation parameter (Ko) at the surface of the site is a combination of the contributions at the reference rock horizon (Ko.ref) and the wave propagation through the site (8K0= K0-Ko,ref). The 8K0 value is computed by the linear-elastic transfer function for the site profile using each of the four base soil case profiles with and without damping following the procedure by Boore and Joyner (1997). For each transfer function, the log-linear slope (6.Ko) is computed. The 6.Ko value is defined as the difference of these two slopes (6.Ko.damping -6.Ko,no damping). The transfer function without damping is used to isolate the effects of the velocity profile from the effects of the damping on the slope transfer function. For example, the linear-elastic transfer functions for the C1-EPRI site profile are computed, as well as the logarithmic mean of transfer functions, shown in Figure 2.3.2.2-3. The .1.Ko,damping is then computed to be 0.0085 s using log-linear fit between 60 and 200 Hz to the logarithmic mean transfer function as shown in Figure 2.3.2.2-3. The 6Ko,no damping is computed to be -0.0002 as shown in Figure 2.3.2.2-4. The .1.Ko,nodarnping value is relatively small because of the selected frequency range and the characteristics of the velocity profile at the site. For the C1-EPRI case profile, this approach provides a .1.Ko value of 0.0087 s. The values for all four site profiles are provided in Table 2.3.2 .2-1. PNNL (2014) provides Ko,ref values tor the C1 and C2 SMB profile, presented in Table 2.3.2.2-2. Using the weights from Figure 7.61 of PNNL (2014), the logarithmic weighted average of Ko.ref is computed to be 0.0205 s. These values are significantly larger than the 8Ko computed for the site, which indicates that the reference condition is controlling the total site attenuation (Ko). The total site attenuation (Ko= 8Ko +Ko.ref) for the four profiles is provided in Table 2.3.2.2-3 and that shows a variation between 0.0287 and 0.0357 s. A log-normal standard deviation of 0.4 is used in randomization to model the uncertainty in the strain-independent damping ratios. 43 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.2.2-1: The Incremental Site Attenuation (ti.KO) for the Four Base-Case Profiles SMB Velocity Model Nonlinear Model C1 C2 EPRI 0.0087 s 0.0086 s PEN 0.0065 s 0.0064 s Table 2.3.2.2-2: The Reference (i.e., base rock) Site Attenuation (Ko,rei) for the Cl and C2 SMB Profiles (Table 7.25 of PNNL, 2014) SMB Velocity Model C1 I C2 Kore! 0.0222 s I 0.0271 s Table 2.3.2.2-3: The Total Site Attenuation (Ko) for the Four Base-Case Profiles SMB Velocity Model Nonlinear Model C1 C2 EPRI 0.0309 s 0.0357 s PEN 0.0287 s 0.0335 s 44 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 0.25 0.20 0.15 0.10 0.05 0.00 I I I I I I

• Reference Kappa (sec) Figure 2.3.2.2*1: Site Attenuation (kappa) at the Reference Condition (Figure 7.66 from PNNL, 2014) 45 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 0.25 0.20 0.15 0.10 0.05 0.00 I I I °-oo 73 °-008 O.o,o O.o,s °-o<o °-o<s 0.030 0.038 °-0-10 O.o"s °-os0 °-os8 SMB Kappa (sec) Figure 2.3.2.2*2: Site Attenuation (kappa) at the SMB Stack (Figure 7.63 from PNNL, 2014) 46 of 136 I 0.06'0 0.03, RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 1.0E*01 1.0E+OO ----Q. E < c: 0 ts 1.0E*01 c: "' u.. ... c: .. 1.0E-02 1.0E-03 0.1 -Logarithmic Mean Fi1 Profile: c 1-epn t.KO [sec): 0.0085 Frequency [Hz) 10 \ \ \ 100 Figure 2.3.2.2-3: Fit Between the Geometric Mean Transfer Function and the Log-Linear Model for the C1-EPRI Base-Case Site Profile with Damping 47 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Q. E < c: 1.0E*01 1 OE+OO c: "' u.. ... c: .. 1 OE-01 0.1 -Logarithmic Mean Fit Profile: c 1-epn t.KO [sec): -0.0002 Frequency [Hz) 10 100 Figure 2.3.2.2-4: Fit Between the Geometric Mean Transfer Function and the Log-Linear Model for the C1-EPRI Base-Case Site Profile without Damping 2.3.3 Randomization of Base Case Profiles The simulated base case profiles for the CGS site include both aleatory and epistemic uncertainty. The site profile consists of an upper supra-basalt zone and the lower SMB stack. The epistemic uncertainty of the supra-basalt zone is characterized by a single base-case velocity profile and two different models tor the nonlinear behavior of the soil. The EPRI (1993) and Peninsular (PEN) Range (Silva et al., 1997) are used and given equal weight. PNNL (2014) provides two sets (C1 and C2) of sixty simulated profiles and associated nonlinear curves for the Saddle Mountain Basalt zone tor the CGS site (Site C). The two sets of simulated profiles correspond to profiles developed using different rock velocity measurement methods. As described in Section 7.2.6 of PNNL (2014), C1 profiles are based on down-hole measurements and given a weight of 0.67, while the C2 profiles are based on PS suspension logging measurements and given a weight of 0.33. The weight for each of the considered profiles is summarized in Table 2.3.3-1. Combining the 2 base profiles representing the supra-basalt and the 2 base profiles representing the lower SMB stack, a total of 4 base profiles are selected for simulation. The 48 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure simulated profiles for the lower SMB stack {60 profiles for each base case) are provided in PNNL {2014). For the supra basalt, variability in the shear-wave velocity profiles has been incorporated in the soil profile simulation to account for the aleatory variability in material properties that is expected to occur across a site at the scale of a typical nuclear facility. For the CGS site, simulated wave velocity profiles were developed from the base case profiles, as presented in Section 2.3.2. The simulation procedure generates a set of sixty site-specific simulated (randomized) soil profiles to represent the dynamic properties of the site while considering the uncertainty associated with each of these properties, and correlations between different parameters. Simulated profiles were generated for the supra-basalt zone, and were subsequently augmented with the simulated profiles provided for the Site C SMB stack in Appendix J of PNNL (2014). As specified in the SPID (EPRI, 2013a), correlation of shear wave velocity between layers was modeled using the USGS B correlation model. In profile simulation, a limit of+/- 2 standard deviations about the median value in each layer was assumed for the limits on random velocity fluctuations, as well as on strain-dependent shear modulus reduction and damping ratios. The simulated damping ratios are limited to a maximum of 15%. The variation in the thickness and S-wave velocity of the supra-basalt layers is presented in Table 2.3.3-2. The variation for the SMB stack is described in Sections 7 and 9 of PNNL (2014). The hard-rock half-space is defined by an S-wave velocity of 9,840 ft/s, a unit weight of 0.177 kcf, and a damping ratio of 0.1% as defined by Section 9.6.1 of PNNL (2014). The combined simulated velocity profiles with the C1 Saddle Mountain Basalt profiles are shown in Figures 2.3.3-1 and 2.3.3-2. Similarly, the C2 Saddle Mountain basalt profiles are shown in Figures 2.3.3-3 and 2.3.3-4. The EPRI and PEN simulated shear-wave velocity profiles have the same simulated velocity profiles, and only have different shear modulus reduction and damping ratio curves. Table 2.3.3-1: The Weight Factors for the Four Base-Case Profiles SMB Velocity Model Nonlinear Model C1 (0.67) C2 (0.33) EPRI (0.5) 0.335 0.165 PEN (0.5) 0.335 0.165 49 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.3-2: Variation of the Thickness and S-wave Velocity in the Supra-Basalt Zone Thickness S-Wave Velocity Stratum Unit Variation Uncertainty, 01nvs P-1 Pasco Gravel +/-22% 0.25 P-2 Pasco Gravel +/-22% 0.25 P-3 Pasco Gravel +/-22% 0.25 P-4 Pasco Gravel +/-22% 0.25 MR-1 Middle Ringold +/-10% 0.25 MR-2 Middle Ringold +/-10% 0.15 MR-3 Middle Ringold +/-10% 0.15 LR-1 Lower Ringold +/-15% 0.15 LR-2 Lower Ringold +/-15% 0.30 LR-3 Lower Ringold +/-15% 0.20 50 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 200 400 CV 600 -0 ttl ,_ (.,!) 0 Qi ca 800 ...... a. CV 0 1000 1 10 20 30 Realization 40 1500 3000 4500 6000 7500 9000 10500 12000 so 60 Figure 2.3.3-1: Bar Plots of the Combined Simulated Site Profiles with the C1 SMB Profile 51 of 136 -V\ --.:t: ->-:!: u 0 Q) > Ill ..!. Ill (]) Ul RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 200 400 v 600 -0 ttl ,_ (.!) 0 Qi co 800 ...... a. Q) 0 1000 1200 1400 0 2000 ***-.... 4000 6000 8000 Shear-Wave Velocity [ft/sec] Realization Median 10000 12000 Figure 2.3.3-2: Line Plots of the Combined Simulated Site Profiles with the C1 SMB Profile 52 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 200 400 CV 600 -0 ttl ,_ (.,!) 0 Qi ca 800 ...... a. CV 0 1000 1 10 20 30 Realization 40 1500 3000 4500 6000 7500 9000 10500 12000 so 60 Figure 2.3.3-3: Bar Plots of the Combined Simulated Site Profiles with the C2 SMB Profile 53 of 136 -V\ --.:t: ->-:!: u 0 Q) > Ill ..!. Ill (]) Ul RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 200 400 ..... . . **-.... ***-* v 600 -0 ttl ,_ (.!) 0 Qi co 800 ...... a. Q) 0 1000 1200 1400 0 2000 4000 6000 8000 Shear-Wave Velocity [ft/sec] 10000 Realization Median 12000 14000 Figure 2.3.3-4: Line Plots of the Combined Simulated Site Profiles with the C2 SMB Profile 54 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 2.3.4 Input Spectra Appendix J of PNNL (2014) provides the hard-rock hazard and site-specific horizontal 5% damped hard-rock acceleration response spectra (ARS) calculated at bedrock with an S-wave velocity of 9,840 ft/s (3,000 m/s). The data for Site C designated for the CGS is used. In the site response analysis simulations, the rock ARS are used as outcrop motions at the bedrock horizon, which is defined by an S-wave velocity of 9,840 ft/s. The rock horizon is identified as top of the Lalo formation in Section 7.2.5 of PNNL (2014). The input motions are provided as both scaled mean spectra and conditional mean spectra (CMS). The site response analyses presented in this report use the CMS. Baker (2010) proposed the concept of the CMS in which a mean response spectrum is modified to fit a target spectral acceleration at a specific frequency, which is referred to as the conditioning frequency. The spectral accelerations at the other frequencies are computed by the Baker (2010) relationship, which provides for realistic scaling of the ground motions. PNNL (2014) provides CMS spectra at the mean annual frequencies of exceedance (MAFEs) and frequencies presented in Table 2.3.4-1. With a total of 4 event spectra for each of the 20 frequencies and the total of 27 MAFEs, a total of 2, 160 spectra were used for each of the simulated profiles for site response analysis. The magnitude and distance of each event is dependent on the deaggregation, and thus vary with MAFE and conditioning frequency. At MAFE of 10-4, the mean magnitude and distances computed for the 20 frequencies of the 4 events are: 0) Mw 5.5 at 5.6 mi (9 km), 1) Mw 6.5 at 7.5 mi (12 km), 2) Mw 7.2 at 13 mi (21 km), and 3) Mw 9.0 at 207 mi (333 km). Examples of the CMS for conditioning frequencies of 1 and 10 Hz and a MAFE of 10"4 are shown in Figures 2.3.4-1 and 2.3.4-2, respectively. The scenario magnitude and distance listed in Figures 2.3.4-1 and 2.3.4-2 are specific to the conditioning frequency and MAFE. In some cases, the weight factor of an event may be zero (see Mw=9.1 event in Figure 2.3.4-2). In the CMS motions provided in PNNL (2014), the methodology is limited to only increase the spectral acceleration at the conditioning frequency. In addition to the acceleration response spectrum, the duration and effective strain ratio need to be defined for each of the input motions. The ground motion duration is estimated using the magnitude and distance of the events listed in CMS text files along with the WUS duration model (Equation H-9) of NUREG/CR-6728 (McGuire. 2001). The durations range from 1.5 to 60.4 seconds and correspond to earthquakes with moment magnitudes from 5.4 to 9.2. For materials with nonlinear properties, the effective strain ratio, which relates the peak shear strain to the effective shear strain, is computed using the following equation from Idriss and Sun (1992): Yeff Mw = (2.3.4-1) Ymax 10 Using the magnitudes reported in CMS text files, the effective strain ratio is computed for each of the events. The effective strain ratios range from 0.44 to 0.82. 55 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.4-1: The MAFE and Conditioning Frequencies of the Conditional Mean Spectra (PNNL, 2014) MAFE Frequency [Hz] 1.00E-02 100.000 7.52E-03 50.000 5.00E-03 33.333 3.00E-03 25.000 2.00E-03 20.000 1.00E-03 13.333 7.50E-04 10.000 5.00E-04 6.667 4.00E-04 5.000 3.00E-04 3.333 2.00E-04 2.500 1.00E-04 2.000 7.SOE-05 1.333 5.00E-05 1.000 3.00E-05 0.667 2.00E-05 0.500 1.00E-05 0.333 7.50E-06 0.200 5.00E-06 0.133 3.00E-06 0.100 2.00E-06 1.00E-06 7.SOE-07 5.00E-07 3.00E-07 2.00E-07 1.00E-07 56 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Cl (I) u 10*1 u 4: Ctl ,_ ..... u (I) a_ Ill -0 (I) a_ E io*2 Ctl 0 '#. U"l Frequency [Hz] ........ 1.0 Hz, AEF: l.Oe-04 UHRS .11 .. : 5.6, R: 7 km, Wt: 0.15 .11 .. : 6.5, R: 11 km, Wt: 0.39 .\/,.: 7.2. R: 20 km. Wt: 0.25 -11,.: 9.0, R: 336 km, Wt: 0.21 Figure 2.3.4-1: The Four Input Rock Conditional Mean Spectra with a Conditioning Frequency of 1 Hz and a MAFE of 10*4.Compared with the Hard-Rock Uniform Hazard Response Spectrum 57 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 101 CMS 10° cu 10*1 It) ... .., u (IJ a_ VI -0 (IJ Cl. 10*2 0 '# U"'t ---*-* -* * * * * * * * * * * * * * * * * * * * * * * * * -* * * * * * * * * * * * * * * * -* * ------------. 10.0 Hz, AEF: l.Oe-04 -UHRS H : 5.4, R 10 km, Wt 0.46 \/,. : 6-4. R: 12 km. Wt: 0.37 .ll,. : 7 .2. R: 20 km. Wt: 0.17 ll,.: 9.1. R: 328 l<m. Wt: 0.00 io*4 L. ________ .J...._ _______ -=:::c::::=======::::::::=..J 10*1 10° 101 102 Frequency [Hz] Figure 2.3.4-2: The Four Input Rock Conditional Mean Spectra with a Conditioning Frequency of 10 Hz and a MAFE of 10*4.Compared with the Hard-Rock Uniform Hazard Response Spectrum 58 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 2.3.5 Methodology To perform the site response analyses for the CGS site, a random vibration theory (RVT) approach and the computer program P-SHAKE was used. This process utilizes a simple, efficient approach for computing site-specific amplification functions and is consistent with existing NRC guidance and the SPID (EPRI, 2013a). Each set of sixty simulated profiles based on the 4 base profiles (4 x 60 = 240), presented in Section 2.3.3, are subjected to the 2, 160 hard rock spectra, presented in Section 2.3.4, at the top of hard rock, which is characterized by a minimum shear-wave velocity of 9,840 ft/s (3,000 mis). The 5% damped acceleration response spectra at the ground surface (SSE control point) are computed, and the amplification functions are calculated as the ratio of the surface response spectra to the hard rock spectra both at 5% spectral damping. For a set of sixty site profile realizations, the logarithmic mean amplification function is computed by: and associated logarithmic standard deviation (a1n) is then computed as N CT1n = N 1 L (In mi -µ1n)2 i=l (2.3.5-1) {2.3.5-2) where m; is is the i-th site amplification. At each MAFE and CMS conditioning frequency, there are four values of µ1n and a1n provided by the four different events. From these four values, the weighted average of the logarithmic mean amplification is computed by: (2.3.5-3) where µ1n.i is the logarithmic mean site amplification for event i and w; is the weight assigned to event i. These weight factors are provided for each of the 2, 160 events in PN NL {2014). The total logarithmic standard deviation (o-1n,r) is computed by: O'tn.T = L Wi [ (µ1n.i -µln,T )2 + i (2.3.5-4) where µ1n.i is the logarithmic mean site amplification for event i, o-111.i is the logarithmic standard deviation for event i, and w; is the weight assigned to event i. This process is repeated for all MAFE and CMS conditioning frequencies to develop the site am pl if ication for one of the case profiles, and then repeated tor the remaining three base-case profiles. As a result, tor each base profile and each MAFE and each frequency for which CMS is provided, the associated logarithmic mean and total standard deviation of the amplification is obtained. 59 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 2.3.6 Amplification Functions The site amplification functions that are developed rely on 518,400 site response analyses, which were carried out for the: 240 simulated profiles from 4 base case profiles {60 simulated profiles for each base case), 20 conditioning frequencies with 4 CMS, 27 mean MAFEs. All different cases are analyzed and processed the same way, thus only a portion of these analyses are taken as examples and are discussed in detail in this report. The portion of site response analyses to be discussed herein is for the sixty simulated profiles for a C1-EPRI profile, CMS period of 0.1 s, MAFE of 1 o-4, and earthquake event 1. The resulting 5% damped surface acceleration response spectra (ARS) and logarithmic mean ARS for one case is shown in Figure 2.3.6-1. The site amplification is computed as the ratio of the surface ARS to the rock (i.e., at outcrop input layer) ARS both at 5% spectral damping, shown in Figure 2.3.6-2. The logarithmic mean using Equation 2.3.5-1 and logarithmic standard deviation using Equation 2.3.5-2 are computed from the sixty realizations, shown in Figure 2.3.6-3. The logarithmic standard deviation is shown in Figure 2.3.6-4. An important characteristic of the site response analyses is the large variability (i.e., large standard deviation) in the response between 2 and 6 Hz, which correspond to natural frequencies of the site. This characteristic is observed in the ARS (Figure 2.3.6-1) and site amplification (Figure 2.3.6-2) and is present to a varying degree in all of the considered cases. For a specific profile and CMS frequency, the arithmetic mean, logarithmic mean, and logarithmic standard deviation from all of the analyses (27 MAFEs and 4 events) are collected together. The weight factors are shown in Figure 2.3.6-5. Using these weight factors, the weighted average of the logarithmic mean site amplification are computed using Equation 2.3.5-3 as shown in Figure 2.3.6-6. The total standard deviation is computed using Equation 2.3.5-4 as shown in Figure 2.3.6-7. The results indicate that as the intensity of the input motion increases (i.e., decreasing MAFE) the 10 Hz site amplification decreases (see Figure 2.3.6-6). This decrease in site amplification is associated with an increase in total standard deviation. This behavior is attributed to the nonlinear response of the site. The composite site amplification (weighted average logarithmic mean and total standard deviation) is developed for each profile. The weighted average logarithmic mean for the C1-EPRI profile are shown in Figure 2.3.6-8. The associated total standard deviations for the C1-EPRI profile are shown in Figure 2.3.6-9. As intensity increases (decreasing MAFE), the amplification tends to shift to lower frequency, due to strain softening, and the once significant 2"d and 3rd natural frequencies decrease. This decrease in amplification at the 2nd and 3rd natural frequencies (2 to 6 Hz) is attributed to varying natural frequencies, again due to strain softening, and is accompanied by an increase in uncertainty (quantified by the logarithmic standard deviation) over the same frequency range. The site amplification results from the other profiles show similar characteristics to the C1 -EPRI profile. 60 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure The logarithmic mean with +/-1 *crin variation of the C1-EPRI site amplification is shown in Figures 2.3.6-10 and 2.3.6-11. The site amplification tends to be a generally smooth curve. The logarithmic mean site amplification for the four profiles are shown in Figures 2.3.6-12 and 2.3.6-13. The profiles show similar behavior with increasing intensity. The weighted average logarithmic mean and total logarithmic standard deviation of the site amplification are presented in Tables 2.3.6-1 and 2.3.6-2 for the C1-EPRI base-case profile, Tables 2.3.6-3 and 2.3.6-4 for the C1-PEN base-case profile, Tables 2.3.6-5 and 2.3.6-6 for the C2-EPRI base-case profile, and Tables 2.3.6-7 and 2.3.6-8 for the C2-PEN base-case profile. It should be noted that in computing the amplification factors, the recommended minimum variability in the site amplification factors, which is defined as a function of spectral frequency from PNNL (2014), was not implemented in the calculation of the surface hazard. This minimum variability is intended include the variability in epistemic uncertainty of the site term and particularly important at low frequencies. However, comparison of the computed standard deviation with the suggested minimum variability shows that for frequencies less than 1 Hz, this minimum epistemic uncertainty is greater than the standard deviation values computed from the site response analysis. For frequencies greater than 1 Hz, the computed standard deviation values are greater than the recommended minimum values from PNNL (2014).These observed differences in the uncertainty would lead to an increase in the surface hazard for frequencies less than 1 Hz by a small margin (note that the as-computed surface hazard exceeds the SSE over this frequency range without the minimum requirement) and does not cause any change for frequencies greater than 1 Hz in the surf ace hazard. Since the refinement using the minimum requirement does not affect the assessment presented in this report, the comparison of GMRS to the SSE (see Section 4.0), and the HCLPF as defined in terms of PGA (see Section 5.0), no further refinement of GMRS is considered. Another point to be noted is the evaluation of the minimum value for soil amplification function. At some frequencies, the calculated site amplification for high base rock amplitudes is less than the minimum value of 0.5 recommended by the SPID (EPRI, 2013a). The 0.5 limit is not imposed here in the calculation of the surface hazard because the intended purpose of this report is to obtain the best estimate of the mean and fractile levels of the seismic response for plant risk assessment with no added conservatism. 61 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.6-1: Weighted Average Logarithmic Mean of the 5% Damped Site Amplification for Base-Case Profile C1-EPRI Period [s] 0.01 0.02 0.03 0.04 0.05 0.08 0.10 0.15 0.20 0.30 0.40 0.50 0.75 1.00 1.50 2.00 3.00 5.00 7.50 10.00 Freauencv [Hzl 100.00 50.00 33.33 25.00 20.00 13.33 10.00 6.67 5.00 3.33 2.50 2.00 1.33 1.00 0.67 0.50 0.33 0.20 0.13 0.10 1.00E-02 1.047 0.900 0.951 1.019 0.968 1.069 1.238 1.796 3.074 3.223 1.671 1.969 2.214 2.453 2.700 1.953 1.444 1.233 1.173 1.147 7.52E-03 0.968 0.847 0.904 0.973 0.923 1.032 1.201 1.756 3.006 3.204 1.684 1.971 2.215 2.447 2.706 1.952 1.432 1.224 1.155 1.130 5.00E-03 0.899 0.791 0.850 0.914 0.865 0.963 1.130 1.687 2.887 3.158 1.700 1.974 2.217 2.437 2.707 1.946 1.424 1.205 1.136 1.117 3.00E-03 0.817 0.733 0.790 0.849 0.802 0.896 1.058 1.607 2.725 3.087 1.715 1.969 2.219 2.419 2.713 1.950 1.421 1.194 1.125 1.113 2.00E-03 0.741 0.686 0.743 0.797 0.753 0.841 0.997 1.537 2.584 3.022 1.731 1.967 2.217 2.402 2.716 1.961 1.419 1.189 1.124 1.114 1.00E-03 0.653 0.595 0.650 0.694 0.655 0.739 0.885 1.399 2.315 2.849 1.753 1.965 2.212 2.359 2.729 1.987 1.419 1.182 1.118 1.116 7.50E-04 0.610 0.559 0.611 0.655 0.619 0.700 0.840 1.329 2.193 2.768 1.758 1.969 2.212 2.344 2.736 2.001 1.420 1.180 1.116 1.117 >-5.00E-04 0.553 0.508 0.555 0.595 0.561 0.642 0.774 1.232 2.032 2.616 1.753 1.976 2.211 2.325 2.746 2.022 1.426 1.177 1.114 1.115 0 4.00E-04 0.523 0.483 0.527 0.565 0.533 0.613 0.742 1.182 1.945 2.548 1.747 1.981 2.217 2.313 2.755 2.035 1.429 1.176 1.113 1.115 c Q) 3.00E-04 0.481 0.449 0.486 0.522 0.494 0.574 0.700 1.120 1.843 2.459 1.738 1.979 2.232 2.306 2.763 2.056 1.433 1.179 1.112 1.115 ::J O" 2.00E-04 0.418 0.399 0.428 0.468 0.446 0.524 0.645 1.033 1.705 2.350 1.715 1.959 2.255 2.293 2.784 2.084 1.441 1.177 1.110 1.114 Q) ..... LL 1.00E-04 0.339 0.325 0.354 0.389 0.375 0.450 0.566 0.897 1.471 2.167 1.648 1.910 2.306 2.295 2.822 2.139 1.458 1.175 1.107 1.114 Q) 7.50E-05 0.309 0.301 0.327 0.361 0.350 0.424 0.538 0.846 1.390 2.088 1.613 1.876 2.316 2.304 2.827 2.166 1.466 1.174 1.106 1.113 0 c 5.00E-05 0.276 0.267 0.329 0.321 0.387 0.495 0.783 1.269 1.963 1.555 2.310 2.307 2.833 2.208 1.480 1.174 1.105 ca 0.298 1.828 1.109 "U Q) 3.00E-05 0.242 0.228 0.261 0.289 0.287 0.348 0.451 0.707 1.136 1.803 1.475 1.759 2.283 2.282 2.846 2.257 1.499 1.174 1.103 1.102 Q) 0 2.00E-05 0.218 0.204 0.235 0.262 0.262 0.319 0.418 0.652 1.043 1.685 1.399 1.679 2.254 2.254 2.853 2.308 1.516 1.176 1.102 1.091 x w 1.00E-05 0.179 0.169 0.198 0.222 0.223 0.277 0.368 0.565 0.900 1.499 1.278 1.490 2.153 2.112 2.764 2.416 1.556 1.181 1.100 1.070 cU 7.50E-06 0.166 0.158 0.186 0.209 0.211 0.261 0.349 0.534 0.846 1.422 1.227 1.425 2.104 2.085 2.715 2.456 1.576 1.183 1.100 1.062 ::J c 5.00E-06 0.152 0.143 0.169 0.191 0.194 0.241 0.325 0.492 0.782 1.315 1.158 1.330 1.985 2.066 2.620 2.492 1.600 1.188 1.100 1.070 c <: 3.00E-06 0.134 0.127 0.151 0.172 0.175 0.217 0.296 0.445 0.706 1.187 1.068 1.226 1.906 1.937 2.456 2.515 1.636 1.197 1.099 1.058 2.00E-06 0.123 0.117 0.139 0.158 0.162 0.202 0.275 0.413 0.649 1.096 0.996 1.122 1.868 1.840 2.344 2.482 1.674 1.205 1.099 1.050 1.00E-06 0.106 0.100 0.121 0.138 0.141 0.177 0.243 0.361 0.556 0.955 0.880 1.000 1.592 1.644 2.217 2.367 1.764 1.226 1.099 1.040 7.50E-07 0.099 0.093 0.114 0.130 0.134 0.168 0.232 0.342 0.519 0.897 0.841 0.944 1.544 1.580 2.117 2.332 1.750 1.232 1.099 1.037 5.00E-07 0.091 0.086 0.105 0.120 0.124 0.156 0.216 0.316 0.477 0.815 0.795 0.881 1.476 1.420 1.964 2.297 1.776 1.243 1.099 1.036 3.00E-07 0.080 0.078 0.095 0.109 0.113 0.142 0.198 0.286 0.428 0.725 0.730 0.802 1.359 1.308 1.765 2.124 1.795 1.249 1.102 1.036 2.00E-07 0.066 0.071 0.089 0.102 0.105 0.133 0.185 0.265 0.393 0.664 0.681 0.752 1.264 1.258 1.590 1.937 1.787 1.260 1.106 1.036 1.00E-07 0.051 0.062 0.078 0.090 0.094 0.118 0.166 0.233 0.338 0.565 0.627 0.648 1.095 1.163 1.332 1.678 1.820 1.288 1.118 1.039 62 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.6-2: Total Logarithmic Standard Deviation of the 5% Damped Site Amplification for Base-Case Profile C1-EPRI Period [s] 0.01 0.02 0.03 0.04 0.05 0.08 0.10 0.15 0.20 0.30 0.40 0.50 0.75 1.00 1.50 2.00 3.00 5.00 7.50 10.00 Freauencv [Hzl 100.00 50.00 33.33 25.00 20.00 13.33 10.00 6.67 5.00 3.33 2.50 2.00 1.33 1.00 0.67 0.50 0.33 0.20 0.13 0.10 1.00E-02 0.299 0.294 0.273 0.316 0.309 0.309 0.287 0.291 0.360 0.475 0.356 0.315 0.130 0.121 0.152 0.133 0.076 0.048 0.045 0.035 7.52E-03 0.284 0.274 0.260 0.309 0.299 0.297 0.279 0.297 0.366 0.467 0.361 0.318 0.131 0.121 0.152 0.134 0.072 0.048 0.033 0.024 5.00E-03 0.264 0.249 0.245 0.301 0.285 0.285 0.272 0.312 0.380 0.454 0.371 0.321 0.133 0.123 0.152 0.135 0.072 0.038 0.033 0.038 3.00E-03 0.240 0.229 0.234 0.294 0.273 0.277 0.269 0.330 0.396 0.437 0.390 0.331 0.135 0.125 0.151 0.137 0.072 0.039 0.030 0.035 2.00E-03 0.228 0.222 0.231 0.291 0.269 0.273 0.269 0.346 0.408 0.425 0.400 0.340 0.139 0.128 0.149 0.140 0.072 0.037 0.029 0.037 1.00E-03 0.222 0.217 0.230 0.290 0.266 0.275 0.276 0.367 0.430 0.403 0.418 0.363 0.153 0.134 0.144 0.147 0.073 0.033 0.032 0.036 7.50E-04 0.221 0.218 0.232 0.290 0.266 0.278 0.280 0.374 0.442 0.397 0.425 0.376 0.163 0.138 0.143 0.151 0.074 0.033 0.032 0.036 >-5.00E-04 0.222 0.222 0.237 0.292 0.268 0.285 0.290 0.382 0.455 0.386 0.430 0.399 0.184 0.146 0.142 0.157 0.078 0.032 0.030 0.035 0 4.00E-04 0.224 0.225 0.241 0.294 0.271 0.290 0.295 0.386 0.462 0.387 0.433 0.415 0.200 0.152 0.143 0.161 0.080 0.032 0.030 0.035 c Q) 3.00E-04 0.228 0.231 0.250 0.301 0.277 0.298 0.304 0.390 0.470 0.393 0.435 0.435 0.225 0.163 0.144 0.166 0.083 0.033 0.030 0.035 ::J O" 2.00E-04 0.228 0.241 0.261 0.310 0.286 0.309 0.317 0.398 0.482 0.407 0.435 0.455 0.264 0.184 0.149 0.173 0.089 0.034 0.030 0.035 Q) ..... LL 1.00E-04 0.240 0.264 0.283 0.328 0.304 0.326 0.341 0.408 0.500 0.440 0.431 0.479 0.327 0.240 0.170 0.181 0.099 0.037 0.030 0.036 Q) 7.50E-05 0.246 0.273 0.292 0.337 0.310 0.333 0.351 0.413 0.508 0.454 0.433 0.487 0.347 0.274 0.182 0.185 0.103 0.038 0.029 0.036 0 c 5.00E-05 0.254 0.284 0.344 0.337 0.364 0.515 0.474 0.444 0.496 0.365 0.111 0.040 0.035 ca 0.300 0.318 0.418 0.318 0.204 0.189 0.029 "U Q) 3.00E-05 0.262 0.283 0.308 0.348 0.325 0.346 0.381 0.430 0.520 0.489 0.452 0.516 0.381 0.343 0.259 0.198 0.121 0.042 0.029 0.034 Q) 0 2.00E-05 0.269 0.291 0.318 0.359 0.334 0.354 0.394 0.438 0.530 0.501 0.456 0.524 0.396 0.369 0.304 0.217 0.132 0.044 0.029 0.031 x w 1.00E-05 0.279 0.304 0.335 0.377 0.349 0.364 0.413 0.454 0.550 0.532 0.485 0.544 0.433 0.352 0.357 0.284 0.158 0.050 0.029 0.025 cU 7.50E-06 0.283 0.308 0.340 0.383 0.353 0.367 0.421 0.460 0.558 0.539 0.496 0.561 0.454 0.374 0.373 0.300 0.169 0.053 0.029 0.023 ::J c 5.00E-06 0.288 0.314 0.350 0.392 0.361 0.371 0.429 0.468 0.568 0.551 0.510 0.579 0.464 0.431 0.385 0.317 0.183 0.059 0.030 0.025 c <: 3.00E-06 0.293 0.321 0.359 0.400 0.371 0.378 0.440 0.480 0.578 0.570 0.524 0.605 0.487 0.451 0.400 0.342 0.200 0.071 0.031 0.022 2.00E-06 0.297 0.326 0.368 0.408 0.376 0.380 0.449 0.489 0.585 0.591 0.536 0.619 0.534 0.457 0.424 0.354 0.219 0.082 0.032 0.020 1.00E-06 0.304 0.335 0.383 0.420 0.387 0.389 0.461 0.505 0.592 0.624 0.578 0.629 0.515 0.458 0.499 0.371 0.271 0.116 0.035 0.020 7.50E-07 0.307 0.340 0.390 0.426 0.392 0.392 0.467 0.510 0.591 0.630 0.588 0.638 0.538 0.462 0.525 0.395 0.244 0.130 0.038 0.019 5.00E-07 0.310 0.344 0.397 0.432 0.400 0.398 0.475 0.517 0.599 0.651 0.608 0.667 0.575 0.408 0.530 0.444 0.250 0.144 0.044 0.019 3.00E-07 0.334 0.351 0.407 0.441 0.408 0.405 0.485 0.528 0.611 0.665 0.626 0.693 0.612 0.401 0.544 0.485 0.257 0.142 0.054 0.020 2.00E-07 0.344 0.357 0.417 0.448 0.416 0.410 0.492 0.537 0.624 0.676 0.631 0.704 0.656 0.421 0.531 0.489 0.256 0.146 0.068 0.022 1.00E-07 0.297 0.366 0.430 0.460 0.428 0.420 0.506 0.554 0.631 0.673 0.662 0.671 0.661 0.450 0.492 0.495 0.303 0.161 0.111 0.028 63 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.6-3: Weighted Average Logarithmic Mean of the 5% Damped Site Amplification for Base-Case Profile C1-PEN Period [s] 0.01 0.02 0.03 0.04 0.05 0.08 0.10 0.15 0.20 0.30 0.40 0.50 0.75 1.00 1.50 2.00 3.00 5.00 7.50 10.00 Freauencv [Hzl 100.00 50.00 33.33 25.00 20.00 13.33 10.00 6.67 5.00 3.33 2.50 2.00 1.33 1.00 0.67 0.50 0.33 0.20 0.13 0.10 1.00E-02 1.173 1.029 1.087 1.164 1.081 1.181 1.369 1.934 3.312 3.377 1.717 2.014 2.249 2.483 2.727 1.965 1.450 1.237 1.176 1.150 7.52E-03 1.090 0.975 1.039 1.118 1.035 1.143 1.330 1.891 3.241 3.354 1.728 2.013 2.248 2.474 2.731 1.962 1.437 1.227 1.157 1.133 5.00E-03 1.017 0.917 0.983 1.056 0.973 1.068 1.254 1.814 3.111 3.299 1.740 2.011 2.244 2.460 2.726 1.955 1.428 1.208 1.139 1.119 3.00E-03 0.927 0.851 0.917 0.983 0.903 0.993 1.172 1.722 2.935 3.224 1.747 1.997 2.241 2.438 2.729 1.956 1.424 1.196 1.127 1.115 2.00E-03 0.842 0.796 0.863 0.923 0.848 0.930 1.103 1.641 2.779 3.162 1.758 1.989 2.236 2.419 2.731 1.967 1.421 1.191 1.125 1.115 1.00E-03 0.739 0.691 0.755 0.806 0.739 0.817 0.980 1.501 2.499 3.018 1.781 1.974 2.226 2.374 2.743 1.992 1.421 1.183 1.119 1.117 7.50E-04 0.690 0.649 0.710 0.762 0.700 0.775 0.934 1.437 2.377 2.954 1.787 1.972 2.221 2.357 2.749 2.004 1.422 1.181 1.117 1.118 >-5.00E-04 0.626 0.591 0.648 0.697 0.639 0.715 0.867 1.350 2.218 2.821 1.784 1.968 2.209 2.333 2.755 2.022 1.426 1.178 1.115 1.115 0 4.00E-04 0.592 0.564 0.617 0.665 0.609 0.686 0.835 1.304 2.131 2.758 1.778 1.966 2.205 2.316 2.762 2.033 1.429 1.176 1.114 1.115 c 3.00E-04 0.547 0.526 0.573 0.620 0.568 0.646 0.793 1.245 2.031 2.669 1.770 1.958 2.206 2.298 2.765 2.050 1.432 1.179 1.112 1.115 ::J O" 2.00E-04 0.478 0.471 0.511 0.563 0.518 0.595 0.736 1.159 1.896 2.549 1.752 1.938 2.209 2.271 2.777 2.073 1.438 1.177 1.111 1.115 Q) ..... LL 1.00E-04 0.392 0.390 0.430 0.478 0.442 0.519 0.653 1.017 1.664 2.340 1.699 1.895 2.226 2.240 2.794 2.117 1.451 1.174 1.107 1.114 7.50E-05 0.359 0.363 0.401 0.447 0.416 0.492 0.623 0.963 1.580 2.252 1.668 1.865 2.228 2.229 2.791 2.139 1.458 1.173 1.106 1.114 0 c 5.00E-05 0.325 0.411 0.454 0.577 1.458 2.127 1.611 1.821 2.229 2.210 2.782 2.172 1.470 1.172 1.105 ca 0.322 0.368 0.384 0.896 1.109 "U Q) 3.00E-05 0.284 0.281 0.326 0.365 0.346 0.413 0.529 0.814 1.325 1.982 1.533 1.748 2.211 2.186 2.759 2.208 1.485 1.172 1.103 1.103 0 2.00E-05 0.257 0.252 0.297 0.334 0.318 0.380 0.494 0.757 1.229 1.875 1.469 1.678 2.179 2.163 2.759 2.243 1.499 1.173 1.102 1.091 x w 1.00E-05 0.212 0.211 0.253 0.286 0.274 0.334 0.441 0.666 1.075 1.709 1.363 1.532 2.074 2.047 2.693 2.325 1.533 1.176 1.099 1.070 cU 7.50E-06 0.197 0.198 0.238 0.270 0.260 0.317 0.420 0.631 1.012 1.636 1.314 1.479 2.028 2.012 2.647 2.369 1.550 1.178 1.099 1.062 ::J c 5.00E-06 0.180 0.180 0.218 0.249 0.241 0.296 0.394 0.585 0.931 1.519 1.237 1.380 1.970 1.964 2.548 2.402 1.571 1.182 1.098 1.070 c <: 3.00E-06 0.159 0.161 0.197 0.225 0.219 0.269 0.362 0.532 0.841 1.377 1.157 1.279 1.895 1.869 2.463 2.390 1.601 1.190 1.098 1.058 2.00E-06 0.146 0.149 0.183 0.209 0.204 0.251 0.338 0.495 0.778 1.272 1.102 1.211 1.776 1.818 2.356 2.386 1.630 1.198 1.098 1.050 1.00E-06 0.126 0.128 0.160 0.184 0.181 0.223 0.303 0.436 0.681 1.120 0.995 1.098 1.629 1.642 2.189 2.354 1.679 1.217 1.096 1.039 7.50E-07 0.118 0.120 0.152 0.175 0.172 0.212 0.290 0.414 0.643 1.059 0.951 1.039 1.582 1.569 2.142 2.323 1.700 1.223 1.096 1.036 5.00E-07 0.109 0.111 0.141 0.164 0.160 0.198 0.271 0.385 0.595 0.974 0.897 0.972 1.464 1.482 2.033 2.251 1.732 1.231 1.097 1.035 3.00E-07 0.096 0.101 0.130 0.150 0.147 0.181 0.250 0.350 0.542 0.870 0.830 0.888 1.350 1.375 1.827 2.126 1.739 1.236 1.099 1.035 2.00E-07 0.079 0.094 0.121 0.141 0.138 0.170 0.235 0.325 0.500 0.804 0.773 0.828 1.279 1.301 1.672 2.003 1.748 1.245 1.103 1.035 1.00E-07 0.062 0.083 0.109 0.126 0.124 0.151 0.212 0.285 0.434 0.688 0.691 0.742 1.191 1.115 1.450 1.823 1.748 1.270 1.114 1.038 64 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.6-4: Total Logarithmic Standard Deviation of the 5% Damped Site Amplification for Base-Case Profile C1-PEN Period [s] 0.01 0.02 0.03 0.04 0.05 0.08 0.10 0.15 0.20 0.30 0.40 0.50 0.75 1.00 1.50 2.00 3.00 5.00 7.50 10.00 Freauencv [Hzl 100.00 50.00 33.33 25.00 20.00 13.33 10.00 6.67 5.00 3.33 2.50 2.00 1.33 1.00 0.67 0.50 0.33 0.20 0.13 0.10 1.00E-02 0.284 0.285 0.272 0.326 0.311 0.309 0.287 0.284 0.358 0.492 0.363 0.317 0.134 0.122 0.156 0.136 0.078 0.050 0.046 0.036 7.52E-03 0.272 0.269 0.263 0.323 0.304 0.300 0.282 0.290 0.366 0.484 0.367 0.320 0.134 0.123 0.155 0.136 0.074 0.049 0.034 0.024 5.00E-03 0.255 0.248 0.253 0.320 0.295 0.292 0.279 0.306 0.382 0.471 0.376 0.323 0.136 0.124 0.155 0.136 0.073 0.039 0.033 0.038 3.00E-03 0.236 0.233 0.248 0.318 0.289 0.287 0.279 0.325 0.399 0.457 0.394 0.332 0.138 0.126 0.154 0.139 0.073 0.039 0.031 0.036 2.00E-03 0.226 0.229 0.249 0.318 0.288 0.286 0.282 0.343 0.411 0.447 0.406 0.339 0.140 0.128 0.153 0.142 0.073 0.037 0.029 0.038 1.00E-03 0.225 0.226 0.252 0.320 0.287 0.289 0.292 0.374 0.430 0.432 0.428 0.355 0.151 0.134 0.149 0.149 0.074 0.034 0.032 0.037 7.50E-04 0.225 0.227 0.253 0.319 0.287 0.292 0.296 0.385 0.440 0.427 0.435 0.363 0.157 0.137 0.148 0.153 0.075 0.033 0.032 0.036 >-5.00E-04 0.227 0.230 0.254 0.321 0.289 0.298 0.303 0.397 0.451 0.413 0.442 0.379 0.168 0.142 0.147 0.158 0.078 0.033 0.031 0.035 0 4.00E-04 0.230 0.233 0.256 0.322 0.291 0.302 0.308 0.402 0.457 0.412 0.444 0.389 0.176 0.145 0.147 0.162 0.080 0.033 0.031 0.035 c Q) 3.00E-04 0.234 0.237 0.261 0.327 0.296 0.309 0.315 0.406 0.465 0.411 0.447 0.404 0.190 0.150 0.148 0.166 0.083 0.034 0.031 0.036 ::J O" 2.00E-04 0.233 0.246 0.272 0.336 0.303 0.320 0.326 0.411 0.478 0.415 0.454 0.423 0.219 0.159 0.151 0.172 0.087 0.034 0.031 0.036 Q) ..... LL 1.00E-04 0.244 0.267 0.292 0.354 0.319 0.341 0.344 0.415 0.498 0.434 0.461 0.461 0.276 0.190 0.164 0.180 0.096 0.036 0.030 0.036 Q) 7.50E-05 0.250 0.276 0.301 0.364 0.325 0.349 0.351 0.419 0.506 0.445 0.461 0.473 0.295 0.212 0.173 0.183 0.100 0.038 0.030 0.037 0 c 5.00E-05 0.258 0.288 0.311 0.370 0.357 0.424 0.519 0.466 0.486 0.243 0.187 0.107 0.040 ca 0.332 0.361 0.463 0.328 0.186 0.030 0.036 "U Q) 3.00E-05 0.266 0.290 0.320 0.373 0.339 0.369 0.374 0.434 0.531 0.493 0.466 0.499 0.357 0.285 0.216 0.190 0.116 0.042 0.030 0.034 Q) 0 2.00E-05 0.273 0.300 0.331 0.384 0.349 0.380 0.386 0.443 0.540 0.514 0.470 0.507 0.378 0.322 0.262 0.199 0.126 0.044 0.029 0.031 x w 1.00E-05 0.282 0.317 0.353 0.403 0.366 0.395 0.408 0.454 0.555 0.545 0.490 0.529 0.397 0.338 0.317 0.247 0.148 0.049 0.029 0.026 cU 7.50E-06 0.286 0.322 0.360 0.410 0.371 0.401 0.417 0.457 0.556 0.558 0.498 0.545 0.406 0.359 0.331 0.281 0.158 0.051 0.030 0.024 ::J c 5.00E-06 0.291 0.331 0.372 0.420 0.380 0.409 0.428 0.461 0.559 0.567 0.504 0.554 0.430 0.386 0.345 0.294 0.171 0.057 0.030 0.025 c <: 3.00E-06 0.296 0.341 0.384 0.432 0.393 0.419 0.443 0.469 0.568 0.577 0.521 0.568 0.471 0.401 0.389 0.301 0.185 0.068 0.031 0.022 2.00E-06 0.301 0.348 0.397 0.442 0.401 0.425 0.455 0.477 0.577 0.588 0.541 0.590 0.470 0.433 0.416 0.320 0.200 0.080 0.032 0.020 1.00E-06 0.309 0.362 0.415 0.459 0.416 0.436 0.470 0.494 0.596 0.620 0.572 0.620 0.500 0.445 0.458 0.369 0.210 0.114 0.035 0.019 7.50E-07 0.313 0.369 0.424 0.468 0.423 0.441 0.478 0.501 0.605 0.633 0.580 0.635 0.521 0.446 0.489 0.390 0.216 0.128 0.038 0.019 5.00E-07 0.318 0.377 0.434 0.477 0.433 0.448 0.487 0.509 0.622 0.645 0.591 0.652 0.529 0.454 0.529 0.410 0.243 0.140 0.043 0.018 3.00E-07 0.345 0.388 0.447 0.490 0.443 0.455 0.501 0.517 0.635 0.655 0.606 0.659 0.539 0.471 0.528 0.443 0.240 0.138 0.053 0.019 2.00E-07 0.360 0.397 0.458 0.500 0.451 0.460 0.509 0.524 0.639 0.650 0.611 0.676 0.572 0.478 0.529 0.469 0.252 0.139 0.067 0.021 1.00E-07 0.314 0.412 0.476 0.517 0.466 0.468 0.522 0.537 0.643 0.660 0.613 0.688 0.638 0.437 0.534 0.506 0.279 0.153 0.110 0.027 65 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.6-5: Weighted Average Logarithmic Mean of the 5% Damped Site Amplification for Base-Case Profile C2-EPRI Period [s] 0.01 0.02 0.03 0.04 0.05 0.08 0.10 0.15 0.20 0.30 0.40 0.50 0.75 1.00 1.50 2.00 3.00 5.00 7.50 10.00 Freauencv [Hzl 100.00 50.00 33.33 25.00 20.00 13.33 10.00 6.67 5.00 3.33 2.50 2.00 1.33 1.00 0.67 0.50 0.33 0.20 0.13 0.10 1.00E-02 0.930 0.787 0.807 0.804 0.786 0.960 1.037 1.556 2.805 2.983 1.536 1.848 2.199 2.376 2.662 1.962 1.446 1.231 1.170 1.144 7.52E-03 0.857 0.737 0.764 0.763 0.744 0.926 1.002 1.515 2.741 2.960 1.546 1.846 2.198 2.369 2.669 1.961 1.435 1.222 1.153 1.128 5.00E-03 0.793 0.687 0.715 0.711 0.692 0.862 0.937 1.448 2.632 2.910 1.556 1.844 2.197 2.357 2.670 1.957 1.428 1.205 1.135 1.115 3.00E-03 0.720 0.636 0.665 0.658 0.639 0.802 0.873 1.370 2.483 2.836 1.563 1.832 2.196 2.336 2.674 1.962 1.425 1.193 1.125 1.112 2.00E-03 0.652 0.595 0.626 0.618 0.600 0.753 0.820 1.303 2.353 2.770 1.573 1.822 2.191 2.318 2.675 1.975 1.424 1.189 1.123 1.113 1.00E-03 0.573 0.515 0.550 0.538 0.522 0.663 0.725 1.182 2.101 2.606 1.584 1.807 2.182 2.273 2.683 2.003 1.425 1.183 1.118 1.116 7.50E-04 0.536 0.485 0.519 0.510 0.495 0.628 0.688 1.122 1.984 2.528 1.587 1.804 2.180 2.257 2.688 2.018 1.427 1.181 1.116 1.116 >-5.00E-04 0.486 0.442 0.474 0.465 0.449 0.575 0.631 1.039 1.829 2.388 1.583 1.797 2.178 2.236 2.693 2.040 1.433 1.179 1.115 1.114 0 4.00E-04 0.459 0.421 0.451 0.443 0.427 0.549 0.604 0.994 1.743 2.326 1.578 1.794 2.181 2.222 2.700 2.055 1.438 1.177 1.114 1.114 c Q) 3.00E-04 0.423 0.392 0.417 0.410 0.396 0.513 0.567 0.941 1.644 2.243 1.572 1.781 2.189 2.210 2.704 2.076 1.443 1.180 1.113 1.114 ::J O" 2.00E-04 0.368 0.349 0.367 0.368 0.357 0.466 0.519 0.865 1.508 2.139 1.555 1.755 2.203 2.192 2.716 2.104 1.452 1.179 1.111 1.114 Q) ..... LL 1.00E-04 0.299 0.285 0.303 0.306 0.300 0.398 0.451 0.746 1.288 1.966 1.494 1.699 2.221 2.183 2.733 2.161 1.471 1.178 1.108 1.114 Q) 7.50E-05 0.273 0.263 0.281 0.283 0.280 0.375 0.427 0.703 1.214 1.892 1.460 1.669 2.221 2.183 2.728 2.190 1.480 1.177 1.108 1.113 0 c 5.00E-05 0.243 0.234 0.256 0.259 0.257 0.341 0.650 1.109 1.778 1.405 2.205 2.172 2.721 2.234 1.496 1.178 1.106 ca 0.392 1.624 1.109 "U Q) 3.00E-05 0.213 0.199 0.225 0.229 0.231 0.307 0.357 0.587 0.993 1.632 1.339 1.555 2.161 2.124 2.716 2.289 1.517 1.179 1.105 1.103 Q) 0 2.00E-05 0.192 0.178 0.203 0.208 0.210 0.281 0.331 0.542 0.910 1.513 1.278 1.502 2.112 2.075 2.680 2.339 1.537 1.182 1.104 1.091 x w 1.00E-05 0.157 0.147 0.170 0.176 0.178 0.243 0.292 0.471 0.786 1.318 1.182 1.358 2.053 1.971 2.529 2.417 1.584 1.187 1.103 1.071 cU 7.50E-06 0.146 0.137 0.160 0.165 0.168 0.230 0.277 0.445 0.741 1.246 1.138 1.302 1.998 1.912 2.463 2.441 1.607 1.190 1.102 1.063 ::J c 5.00E-06 0.133 0.124 0.145 0.151 0.155 0.213 0.258 0.410 0.684 1.142 1.077 1.229 1.944 1.887 2.343 2.427 1.641 1.196 1.102 1.071 c <: 3.00E-06 0.117 0.110 0.130 0.136 0.139 0.192 0.235 0.372 0.618 1.023 0.990 1.136 1.857 1.862 2.213 2.380 1.689 1.204 1.102 1.060 2.00E-06 0.108 0.101 0.120 0.126 0.129 0.178 0.219 0.345 0.573 0.941 0.915 1.040 1.763 1.807 2.113 2.326 1.735 1.212 1.103 1.052 1.00E-06 0.092 0.087 0.104 0.110 0.113 0.157 0.195 0.304 0.497 0.813 0.781 0.886 1.579 1.685 1.975 2.237 1.816 1.231 1.102 1.041 7.50E-07 0.087 0.081 0.098 0.103 0.106 0.149 0.186 0.289 0.467 0.774 0.741 0.840 1.482 1.583 1.890 2.171 1.820 1.240 1.102 1.039 5.00E-07 0.079 0.074 0.091 0.096 0.098 0.139 0.174 0.269 0.430 0.708 0.686 0.770 1.323 1.489 1.794 2.071 1.831 1.260 1.103 1.037 3.00E-07 0.070 0.067 0.082 0.087 0.090 0.127 0.160 0.245 0.387 0.638 0.639 0.686 1.183 1.366 1.640 1.960 1.836 1.286 1.105 1.038 2.00E-07 0.058 0.062 0.076 0.081 0.083 0.118 0.150 0.228 0.356 0.591 0.585 0.638 1.067 1.303 1.547 1.844 1.826 1.310 1.108 1.039 1.00E-07 0.045 0.054 0.067 0.072 0.074 0.105 0.135 0.201 0.307 0.520 0.524 0.560 0.928 1.121 1.298 1.609 1.807 1.365 1.118 1.041 66 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.6-6: Total Logarithmic Standard Deviation of the 5% Damped Site Amplification for Base-Case Profile C2-EPRI Period [s] 0.01 0.02 0.03 0.04 0.05 0.08 0.10 0.15 0.20 0.30 0.40 0.50 0.75 1.00 1.50 2.00 3.00 5.00 7.50 10.00 Freauencv [Hzl 100.00 50.00 33.33 25.00 20.00 13.33 10.00 6.67 5.00 3.33 2.50 2.00 1.33 1.00 0.67 0.50 0.33 0.20 0.13 0.10 1.00E-02 0.294 0.292 0.266 0.280 0.266 0.273 0.255 0.245 0.347 0.483 0.336 0.323 0.148 0.150 0.132 0.132 0.074 0.047 0.044 0.034 7.52E-03 0.276 0.269 0.248 0.264 0.247 0.259 0.241 0.246 0.354 0.474 0.340 0.325 0.150 0.151 0.132 0.133 0.072 0.047 0.032 0.023 5.00E-03 0.252 0.239 0.226 0.244 0.218 0.244 0.225 0.251 0.368 0.461 0.349 0.329 0.152 0.152 0.133 0.134 0.072 0.037 0.033 0.037 3.00E-03 0.222 0.214 0.213 0.229 0.194 0.239 0.214 0.259 0.387 0.443 0.367 0.340 0.156 0.155 0.132 0.137 0.073 0.038 0.029 0.035 2.00E-03 0.205 0.204 0.212 0.226 0.188 0.241 0.212 0.268 0.403 0.429 0.376 0.350 0.161 0.158 0.129 0.140 0.072 0.036 0.029 0.037 1.00E-03 0.198 0.198 0.222 0.229 0.187 0.254 0.219 0.291 0.430 0.401 0.391 0.377 0.176 0.167 0.126 0.146 0.074 0.033 0.031 0.035 7.50E-04 0.196 0.200 0.230 0.231 0.190 0.262 0.224 0.303 0.443 0.391 0.397 0.390 0.187 0.172 0.125 0.150 0.076 0.032 0.031 0.035 >-5.00E-04 0.199 0.204 0.241 0.238 0.196 0.275 0.233 0.318 0.456 0.374 0.406 0.411 0.209 0.181 0.126 0.155 0.080 0.032 0.030 0.034 0 4.00E-04 0.202 0.209 0.248 0.241 0.201 0.282 0.238 0.325 0.462 0.374 0.411 0.425 0.224 0.188 0.127 0.158 0.082 0.033 0.030 0.034 c Q) 3.00E-04 0.207 0.215 0.259 0.249 0.208 0.293 0.245 0.332 0.467 0.376 0.417 0.440 0.246 0.200 0.130 0.161 0.085 0.033 0.030 0.034 ::J O" 2.00E-04 0.210 0.227 0.275 0.260 0.220 0.305 0.255 0.342 0.474 0.389 0.425 0.458 0.281 0.222 0.136 0.165 0.091 0.034 0.030 0.035 Q) ..... LL 1.00E-04 0.226 0.252 0.301 0.278 0.240 0.325 0.271 0.357 0.482 0.425 0.425 0.479 0.333 0.282 0.162 0.171 0.101 0.037 0.029 0.035 Q) 7.50E-05 0.233 0.261 0.311 0.284 0.246 0.332 0.276 0.365 0.487 0.442 0.425 0.488 0.348 0.310 0.176 0.173 0.106 0.039 0.029 0.035 0 c 5.00E-05 0.242 0.274 0.255 0.332 0.375 0.496 0.470 0.427 0.494 0.344 0.177 0.113 0.041 0.035 ca 0.321 0.291 0.282 0.368 0.206 0.029 "U Q) 3.00E-05 0.252 0.273 0.331 0.295 0.264 0.339 0.293 0.390 0.500 0.494 0.433 0.501 0.393 0.350 0.278 0.186 0.124 0.043 0.029 0.033 Q) 0 2.00E-05 0.259 0.281 0.342 0.301 0.271 0.346 0.303 0.399 0.502 0.505 0.432 0.517 0.407 0.358 0.316 0.201 0.135 0.045 0.029 0.030 x w 1.00E-05 0.269 0.294 0.360 0.311 0.282 0.356 0.320 0.414 0.509 0.517 0.463 0.527 0.472 0.363 0.339 0.250 0.158 0.051 0.029 0.025 cU 7.50E-06 0.272 0.297 0.366 0.315 0.286 0.359 0.327 0.420 0.511 0.522 0.479 0.536 0.478 0.355 0.349 0.275 0.169 0.053 0.029 0.023 ::J c 5.00E-06 0.277 0.303 0.377 0.321 0.292 0.364 0.336 0.428 0.517 0.532 0.503 0.560 0.500 0.387 0.350 0.281 0.185 0.058 0.030 0.025 c <: 3.00E-06 0.282 0.310 0.388 0.327 0.298 0.372 0.349 0.438 0.530 0.545 0.515 0.590 0.537 0.453 0.370 0.290 0.203 0.066 0.030 0.022 2.00E-06 0.286 0.315 0.398 0.332 0.304 0.376 0.360 0.448 0.539 0.559 0.519 0.602 0.561 0.476 0.392 0.303 0.223 0.073 0.031 0.020 1.00E-06 0.294 0.324 0.414 0.342 0.312 0.386 0.376 0.464 0.562 0.584 0.542 0.624 0.619 0.525 0.463 0.342 0.247 0.093 0.034 0.020 7.50E-07 0.296 0.328 0.421 0.346 0.315 0.390 0.384 0.470 0.570 0.592 0.552 0.633 0.629 0.521 0.464 0.353 0.239 0.107 0.035 0.020 5.00E-07 0.300 0.333 0.429 0.352 0.319 0.398 0.395 0.477 0.580 0.604 0.561 0.656 0.619 0.522 0.490 0.373 0.231 0.135 0.038 0.019 3.00E-07 0.326 0.339 0.440 0.359 0.324 0.405 0.409 0.487 0.591 0.611 0.583 0.631 0.643 0.518 0.521 0.434 0.232 0.164 0.044 0.020 2.00E-07 0.340 0.344 0.449 0.365 0.328 0.412 0.419 0.492 0.595 0.617 0.585 0.624 0.639 0.538 0.549 0.459 0.239 0.181 0.050 0.021 1.00E-07 0.294 0.352 0.464 0.375 0.335 0.426 0.437 0.501 0.605 0.645 0.600 0.606 0.658 0.555 0.506 0.487 0.269 0.215 0.069 0.025 67 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.6-7: Weighted Average Logarithmic Mean of the 5% Damped Site Amplification for Base-Case Profile C2-PEN Period [s] 0.01 0.02 0.03 0.04 0.05 0.08 0.10 0.15 0.20 0.30 0.40 0.50 0.75 1.00 1.50 2.00 3.00 5.00 7.50 10.00 Freauencv [Hzl 100.00 50.00 33.33 25.00 20.00 13.33 10.00 6.67 5.00 3.33 2.50 2.00 1.33 1.00 0.67 0.50 0.33 0.20 0.13 0.10 1.00E-02 1.037 0.888 0.907 0.896 0.863 1.057 1.138 1.684 3.031 3.137 1.584 1.894 2.236 2.406 2.689 1.974 1.452 1.235 1.174 1.147 7.52E-03 0.960 0.838 0.863 0.853 0.820 1.022 1.102 1.641 2.963 3.111 1.592 1.890 2.233 2.396 2.693 1.971 1.439 1.226 1.155 1.130 5.00E-03 0.892 0.784 0.812 0.799 0.765 0.953 1.032 1.566 2.844 3.052 1.598 1.883 2.227 2.380 2.689 1.965 1.432 1.207 1.137 1.117 3.00E-03 0.812 0.727 0.756 0.740 0.705 0.886 0.960 1.476 2.680 2.971 1.597 1.862 2.220 2.354 2.689 1.968 1.429 1.196 1.126 1.114 2.00E-03 0.736 0.681 0.712 0.694 0.660 0.829 0.900 1.398 2.535 2.905 1.603 1.847 2.212 2.334 2.689 1.980 1.426 1.190 1.124 1.114 1.00E-03 0.645 0.589 0.625 0.604 0.574 0.728 0.795 1.266 2.270 2.760 1.613 1.821 2.198 2.287 2.696 2.007 1.427 1.184 1.118 1.116 7.50E-04 0.602 0.554 0.590 0.571 0.544 0.691 0.756 1.208 2.153 2.696 1.616 1.814 2.192 2.268 2.699 2.021 1.428 1.182 1.117 1.117 >-5.00E-04 0.546 0.505 0.541 0.523 0.495 0.637 0.698 1.130 2.000 2.568 1.611 1.802 2.180 2.243 2.700 2.041 1.434 1.179 1.115 1.115 0 4.00E-04 0.516 0.482 0.516 0.499 0.473 0.609 0.671 1.089 1.917 2.509 1.605 1.794 2.175 2.225 2.705 2.053 1.437 1.178 1.114 1.115 c 3.00E-04 0.476 0.450 0.479 0.465 0.440 0.573 0.634 1.039 1.820 2.425 1.598 1.777 2.174 2.205 2.704 2.071 1.441 1.181 1.113 1.115 ::J O" 2.00E-04 0.417 0.403 0.426 0.421 0.400 0.526 0.585 0.966 1.687 2.310 1.583 1.744 2.173 2.175 2.708 2.095 1.449 1.179 1.111 1.115 Q) ..... LL 1.00E-04 0.342 0.334 0.358 0.356 0.340 0.456 0.514 0.844 1.460 2.108 1.541 1.686 2.169 2.137 2.705 2.141 1.465 1.177 1.109 1.114 7.50E-05 0.313 0.310 0.333 0.331 0.319 0.432 0.489 0.798 1.380 2.024 1.514 1.656 2.163 2.122 2.692 2.165 1.473 1.176 1.108 1.114 0 c 5.00E-05 0.277 0.305 0.397 0.451 0.739 1.264 1.904 1.464 2.150 2.098 2.667 2.200 1.486 1.176 1.106 1.110 ca 0.280 0.306 0.294 1.613 "U Q) 3.00E-05 0.247 0.238 0.272 0.273 0.266 0.360 0.412 0.669 1.140 1.766 1.398 1.546 2.106 2.062 2.624 2.239 1.504 1.177 1.105 1.103 0 2.00E-05 0.223 0.214 0.247 0.249 0.243 0.331 0.383 0.620 1.053 1.665 1.340 1.484 2.051 2.024 2.600 2.274 1.521 1.179 1.104 1.092 x w 1.00E-05 0.184 0.178 0.209 0.213 0.208 0.290 0.340 0.545 0.921 1.499 1.245 1.358 1.955 1.886 2.511 2.336 1.562 1.183 1.102 1.071 cU 7.50E-06 0.171 0.167 0.197 0.201 0.197 0.274 0.323 0.518 0.870 1.435 1.207 1.313 1.915 1.843 2.419 2.360 1.584 1.186 1.101 1.063 ::J c 5.00E-06 0.155 0.151 0.181 0.185 0.182 0.255 0.303 0.481 0.805 1.348 1.159 1.251 1.857 1.788 2.313 2.378 1.615 1.190 1.101 1.071 c <: 3.00E-06 0.137 0.135 0.163 0.167 0.164 0.232 0.278 0.438 0.730 1.231 1.097 1.183 1.782 1.718 2.191 2.358 1.661 1.198 1.101 1.059 2.00E-06 0.126 0.125 0.151 0.155 0.153 0.216 0.261 0.408 0.673 1.133 1.039 1.134 1.715 1.675 2.085 2.298 1.701 1.206 1.101 1.052 1.00E-06 0.109 0.107 0.132 0.136 0.134 0.192 0.235 0.361 0.586 0.984 0.936 1.026 1.596 1.567 1.911 2.191 1.768 1.225 1.100 1.041 7.50E-07 0.102 0.100 0.125 0.129 0.127 0.183 0.225 0.343 0.555 0.925 0.898 0.972 1.547 1.513 1.848 2.120 1.768 1.233 1.100 1.038 5.00E-07 0.093 0.093 0.116 0.120 0.118 0.171 0.211 0.319 0.515 0.847 0.847 0.904 1.462 1.446 1.759 2.038 1.780 1.252 1.100 1.037 3.00E-07 0.082 0.084 0.106 0.110 0.108 0.157 0.195 0.291 0.469 0.754 0.773 0.834 1.312 1.353 1.639 1.900 1.783 1.279 1.103 1.037 2.00E-07 0.068 0.078 0.099 0.103 0.101 0.147 0.184 0.271 0.435 0.691 0.714 0.773 1.215 1.287 1.506 1.829 1.786 1.301 1.105 1.038 1.00E-07 0.053 0.069 0.089 0.091 0.090 0.132 0.166 0.240 0.383 0.607 0.626 0.680 1.069 1.152 1.307 1.637 1.752 1.355 1.114 1.040 68 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.6-8: Total Logarithmic Standard Deviation of the 5% Damped Site Amplification for Base-Case Profile C2-PEN Period [s] 0.01 0.02 0.03 0.04 0.05 0.08 0.10 0.15 0.20 0.30 0.40 0.50 0.75 1.00 1.50 2.00 3.00 5.00 7.50 10.00 Freauencv [Hzl 100.00 50.00 33.33 25.00 20.00 13.33 10.00 6.67 5.00 3.33 2.50 2.00 1.33 1.00 0.67 0.50 0.33 0.20 0.13 0.10 1.00E-02 0.281 0.284 0.262 0.281 0.259 0.274 0.252 0.241 0.345 0.502 0.344 0.324 0.152 0.153 0.136 0.134 0.076 0.048 0.045 0.035 7.52E-03 0.266 0.265 0.247 0.268 0.242 0.263 0.241 0.243 0.353 0.494 0.349 0.327 0.153 0.153 0.136 0.135 0.073 0.048 0.033 0.024 5.00E-03 0.245 0.240 0.230 0.251 0.215 0.252 0.228 0.250 0.369 0.481 0.357 0.330 0.155 0.154 0.135 0.136 0.073 0.038 0.033 0.037 3.00E-03 0.220 0.220 0.221 0.240 0.193 0.249 0.220 0.259 0.389 0.465 0.374 0.340 0.158 0.157 0.134 0.138 0.074 0.039 0.030 0.035 2.00E-03 0.206 0.212 0.223 0.238 0.188 0.251 0.220 0.269 0.405 0.453 0.385 0.348 0.163 0.160 0.133 0.142 0.073 0.037 0.029 0.037 1.00E-03 0.201 0.208 0.235 0.242 0.188 0.263 0.228 0.289 0.428 0.433 0.404 0.368 0.175 0.167 0.130 0.148 0.075 0.034 0.032 0.036 7.50E-04 0.200 0.208 0.242 0.244 0.191 0.269 0.233 0.299 0.440 0.425 0.410 0.379 0.182 0.171 0.129 0.152 0.077 0.033 0.032 0.036 >-5.00E-04 0.203 0.212 0.253 0.250 0.196 0.280 0.242 0.314 0.453 0.408 0.416 0.396 0.195 0.178 0.130 0.157 0.080 0.033 0.030 0.035 0 4.00E-04 0.206 0.214 0.259 0.254 0.200 0.287 0.246 0.322 0.461 0.405 0.419 0.407 0.204 0.182 0.131 0.159 0.082 0.033 0.030 0.035 c Q) 3.00E-04 0.211 0.219 0.270 0.261 0.206 0.297 0.253 0.331 0.469 0.401 0.423 0.419 0.219 0.189 0.132 0.162 0.085 0.034 0.030 0.035 ::J O" 2.00E-04 0.213 0.228 0.286 0.272 0.216 0.311 0.263 0.346 0.481 0.402 0.433 0.432 0.247 0.201 0.137 0.166 0.090 0.035 0.030 0.035 Q) ..... LL 1.00E-04 0.228 0.251 0.312 0.293 0.235 0.335 0.279 0.364 0.495 0.413 0.450 0.460 0.295 0.238 0.153 0.170 0.099 0.037 0.030 0.036 Q) 7.50E-05 0.235 0.261 0.322 0.301 0.242 0.345 0.285 0.373 0.500 0.424 0.454 0.471 0.312 0.260 0.163 0.172 0.103 0.038 0.030 0.036 0 c 5.00E-05 0.244 0.274 0.310 0.252 0.350 0.508 0.445 0.458 0.482 0.181 0.173 0.110 0.040 0.035 ca 0.333 0.292 0.384 0.343 0.291 0.030 "U Q) 3.00E-05 0.255 0.276 0.345 0.319 0.264 0.363 0.304 0.398 0.515 0.472 0.459 0.496 0.367 0.328 0.220 0.175 0.119 0.043 0.029 0.034 Q) 0 2.00E-05 0.263 0.286 0.359 0.328 0.273 0.374 0.313 0.406 0.520 0.492 0.459 0.506 0.379 0.354 0.270 0.182 0.128 0.045 0.029 0.031 x w 1.00E-05 0.276 0.304 0.382 0.344 0.286 0.388 0.328 0.422 0.528 0.524 0.471 0.524 0.411 0.338 0.342 0.216 0.150 0.049 0.029 0.025 cU 7.50E-06 0.281 0.310 0.390 0.349 0.291 0.392 0.334 0.429 0.531 0.537 0.480 0.532 0.426 0.346 0.340 0.244 0.161 0.052 0.029 0.024 ::J c 5.00E-06 0.287 0.318 0.404 0.356 0.298 0.398 0.344 0.437 0.536 0.559 0.499 0.545 0.454 0.360 0.350 0.274 0.175 0.056 0.030 0.025 c <: 3.00E-06 0.293 0.328 0.418 0.365 0.306 0.407 0.357 0.447 0.544 0.581 0.515 0.569 0.488 0.383 0.372 0.301 0.194 0.063 0.030 0.022 2.00E-06 0.298 0.335 0.431 0.371 0.312 0.411 0.367 0.455 0.547 0.595 0.526 0.593 0.515 0.415 0.391 0.306 0.209 0.070 0.031 0.020 1.00E-06 0.307 0.348 0.452 0.383 0.322 0.420 0.385 0.468 0.558 0.606 0.563 0.617 0.555 0.452 0.429 0.343 0.231 0.090 0.033 0.020 7.50E-07 0.310 0.354 0.461 0.388 0.326 0.424 0.392 0.473 0.564 0.606 0.577 0.616 0.571 0.456 0.449 0.351 0.213 0.103 0.034 0.019 5.00E-07 0.314 0.362 0.472 0.394 0.331 0.431 0.404 0.479 0.571 0.608 0.597 0.634 0.596 0.472 0.481 0.374 0.219 0.131 0.037 0.018 3.00E-07 0.342 0.371 0.487 0.403 0.337 0.438 0.419 0.489 0.579 0.612 0.599 0.656 0.609 0.492 0.513 0.404 0.218 0.162 0.043 0.019 2.00E-07 0.364 0.379 0.499 0.409 0.343 0.445 0.429 0.497 0.587 0.619 0.596 0.660 0.624 0.489 0.510 0.445 0.236 0.178 0.049 0.020 1.00E-07 0.321 0.392 0.519 0.422 0.351 0.457 0.447 0.505 0.600 0.632 0.597 0.666 0.638 0.497 0.496 0.483 0.268 0.215 0.067 0.023 69 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 2 Realizations * * * *
• Arithmetic Mean 1.8 -Logarithmic Mean Profile: 1.6 Period c1 -epri 0.100 sec 1.00E-4 s 1.4 c 0 :;::; QI 1.2 Qi 0.. Cl>_ 0.8 0.. E 0.6 0.4 0.2 AEF: Event 1 o-------0.1 10 Frequency [Hz) Figure 2.3.6-1: The Computed Surface 5% Damped Acceleration Response Spectrum (Profile: C1-EPRI, CMS Period: 0.1 sec, AFE: 1E-4, and Event: 1) 70 of 136 100 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 7.0 6.0 5.0 c Ill u i;::: a 4.o E <( ii) i:i 3.0 E C'll c ;!!. I() 2.0 1.0 0.0 0.1 Profile: c1 -epri Realizations Period 0.100 sec AEF 1.00E-4 *****Arithmetic Mean Event: 1 -Logarithmic Mean 10 Frequency [Hz) Figure 2.3.6-2: The Individual Realizations and Arithmetic Site Amplification (Profile: C1-EPRI, CMS Period: 0.1 sec, AFE: 1E-4, and Event: 1) 71 of 136 100 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure c 0 4.0 3.5 3.0 :; 2.5 u !E c.. E <( 2.0 ii) "C E 1.5 C'll c 0.5 0.0 Profile: Period AEF Event 0.1 c1 -epri 0.100 sec 1.00E-4 1 Frequency [Hz) 10 *******Arithmetic Mean --Logarithmic Mean ---*+/-a_ln Variation 100 Figure 2.3.6-3: The Arithmetic, Logarithmic and +/-a1n Variation of the Site Amplification (Profile: C1 -EPRI, CMS Period: 0.1 sec, AFE: 1 E-4, and Event: 1) 72 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 0.60 0.50 0.10 0.00 0.1 Profile: c1-epri Period: 0.100 sec AEF: 1.00E-4 Event: 1 10 Frequency [Hz) Figure 2.3.6-4: The Logarithmic Standard Deviation of the Site Amplification (Profile: C1-EPRI, CMS Period: 0.1 sec, AFE: 1E-4, and Event: 1) 73 of 136 100 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 1.0 0.8 0.5 en -Event 0 -Event 1 Event2 -Event 3 Profile: Period: Frequency: . ---c1-epri 0.100 sec 10.000 Hz ---------------------.... -.... .... --------0.3 0.0 --1.00E-07 1.00E-06 1.00E-05 1.00E-04 Annual Exceedence Frequency (1fyear] ---1.00E-03 Figure 2.3.6-5: The Weight Factors for the Four Events at the Various MAFE (Profile: C1-EPRI, CMS Period: 0.1 sec) The magnitude and distance of each event varies with MAFE 74 of 136 _. -1.00E-02 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure c 0 :;::; Ill u !E c.. 2.5 2.0 E 1.5 <( .SI (ii c :ll :E .!:! Qi 1.0 E .s *i:::: <( 0.5 -Event 0 -Event 1 Event2 -Event 3 -Weighted Average Profile: Period: Frequency: c1-epri 0.100 sec 10000 Hz ---_,,,_.-___ ,,,,._ ---0.0 1 OOE-07 1.00E-06 1.00E-05 1.00E-04 Annual Exceedence Frequency (1fyear] / / 1.00E-03 / I I I I Figure 2.3.6-6: The Weighted Average of the Logarithmic Site Amplification for the Four Events at the Various MAFE (Profile: C1-EPRI, CMS Period: 0.1 sec) 75 of 136 I I I I 1.00E-02 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure c 0 :;::; Cll u Q. E c( ii) c Cll Q) :E u .E -*c: Cll CJ) 0 ....I 2.5 -Event 0 -Event 1 Event2 -Event 3 2.0 -Weighted Average Profile: c1-epri Period: 0.100 sec Frequency: 10.000 Hz 1.5 1.0 0.5 ---___ ..... __ _ *---------0.0 1.00E-07 1.00E-06 I I I I I I I I / 1.00E-05 1.00E-04 1.00E-03 1 OOE-02 Annual Exceedence Frequency [1/year) Figure 2.3.6-7: The Total Logarithmic Standard Deviation for the Four Events at the Various MAFE (Profile: C1-EPRI, CMS Period: 0.1 sec) 76 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 3.0 ..................................................................................... . ci. E <t 2.5 (I) ...... iJ) c Ctl (IJ :a .!::::! 2.0 E ..c ...... *;:: Ctl OI 3 . ,'i* L <:-r-4 LL UJ <t c ro (IJ 1.5 Ctl ,_ ./\\***********. ... \* .... ...... 10-5 :a (IJ "C (IJ ...... \'. -5' 1.0 '\ \. . ..... * .... .... \ ... '\. ' 0.5 .................................... . . . \::t* .............. .. .. -.................... ............ .................... io-10° io 102 Frequency [Hz] Figure 2.3.6-8: Line Plots of the Weighted Average Logarithmic Site Amplification for the C1-EPRI Profile 77 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure ci_ E <l: QI ...... Vl CV ..c. ...... .._ 0 c:: 0 tlJ *:; CV Q -0 ,_ tlJ -0 c tlJ ...... Vl E ..c. ...... tlJ Ol 0 ....J -;o ,..., i2 0.7 10-3 0.6 0.5 10*4 L >--r-4 0.4 LL UJ <l: c: ro v 10-5 :a 0.3 0.2 10-6 0.1 .................... ............ ...................... 10-10° 10 102 Frequency [Hz] Figure 2.3.6-9: Line Plot of the Total Standard Deviation of the Site Amplification for the C1-EPRI Profile 78 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 100.00 Hz 50.00 Hz ******** ... .. .. ........... ----1 /= 33.33 Hz 25.00 Hz ........... ----1 I= 20.00 Hz 13.33 Hz ** ... ........... ----1 /= 10.00 Hz 10*1 .....__.__ __ _.._ ____ ....._ __ ........._ ........ 5.00 Hz 10-1 .....__.__....____._. .......... __ ........... .-..........____.__ .................. 10-2 10-1 10° 101 10*2 10-1 10° Input PSA at /(g] Input PSA at I [g] Figure 2.3.6-10: Logarithmic with +/-1-a1n Variation of the C1-EPRI Site Amplification at Frequencies from 100.00 to 3.33 Hz 79 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 2.50 Hz 2.00 Hz 1.33 Hz ........ 1.00 Hz --10*1 .....__ ___ _....... ____ ...._ ___ __. I 0.67 Hz 0-50 Hz 10*1 .....__._ __ ......._ __ __.__......__..___.............., 0.33 Hz ........ 0.20 Hz -,_ --->--10*1 .....___._ __ _....... ____ ...._ ___ __. I 0.13 Hz 0.10 Hz a. 100 ------------QI ..,,, ill 10* l .....__._....___......._ __ __.__.__._......_ ___ ..___.............., 10*2 10*1 10° 101 10*2 Input PSA at I [g] 10*1 10° Input PSA at /(g] Figure 2.3.6-11: Logarithmic with +/-1 *a1n Variation of the C1 -EPRI Site Amplification at Frequencies from 2.50 to 0.10 Hz 80 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure ci E <( QI ..... ii) ci E <( QI ...., Vi ci E <( QI ..... ii) ci E <( QI ..... ii) ci E <( QI ..... ii) 100.00 Hz 100 10*1 ........... ---11 f= 33.33 Hz 10° -***** ..... 10*1 ........... ---11 f= 20.00 Hz 100 ****** .... 10*1 *********** ..... **---........... ---11 f= 10.00 Hz 10° -**-... **-... ****** ................ 10*1 5.00 Hz 100 10-1 10-2 10-1 10° Input PSA at I [g] 50.00 Hz ********** .. 25.00 Hz 13.33 Hz ********* .... -I 3.33 Hz 10-1 10° Input PSA at /(g] Figure 2.3.6-12: The Logarithmic Mean from the C1-EPRI (red line), C1-PEN (orange line), C2-EPRI (green line), and C2-PEN (blue line) Profiles at Frequencies from 100.00 to 3.33 Hz 81 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 2.so Hz 1.33 Hz -10*1 .....__ ___ _.._ ____ .......__ ___ _..... 0.67 Hz 0.33 Hz -10*1 .....__ ___ _.._ ____ .......__ ___ _..... 0.13 Hz a. 100 Q) ..,,, ill 1.00 Hz -I 0-50 Hz 0.20 Hz -I 0.10 Hz 10*1 .....__.__....____._. .......... __ ........... .-..........____._ _ _.... ........ 10*2 10*1 10° 101 10*2 10*1 10° Input PSA at /(g] Input PSA at I [g] Figure 2.3.6-13: The Logarithmic Mean from the C1-EPRI (red line), C1-PEN (orange line), C2-EPRI (green line), and C2-PEN (blue line) Profiles at Frequencies from 2.50 to 0.10 Hz 82 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 2.3. 7 Control Point Seismic Hazard Curves The procedure to develop probabilistic site-specific control point hazard curves used in the present analysis follows the methodology described in McGuire et al. (2001) and Bazzurro and Cornell (2004). This procedure (referred to as "Approach 3") computes a site-specific control point hazard curve for a broad range of spectral accelerations, given the site-specific baserock hazard curve (Section 2.2.2), and site-specific estimates of soil or soft-rock response (i.e., median amplification factors) and associated uncertainties {i.e., sigma in natural log units), presented in the previous section. The input base rock hazard curves are provided for a suite of 20 spectral frequencies which span the frequency range of 100 -0.1 Hz. Site response results are provided for the two base case soil profiles and two sets of soil damping ratio and shear modulus reduction curves, described earlier in this report. Given these input baserock hazard curves and the resulting site response analyses, control point hazard curves are developed using Approach 3 at each of the 20 spectral frequencies for the mean and five fractile levels (i.e., 5th, 16th, soth, a4th, and 95th percentiles), based on the individual combinations of the two soil profiles and two soil curves. Given the assigned weights of 0.67 for Profile C1 and 0.33 for Profile C2 and equal weights for the two sets of soil curves, a weighted average control point hazard curve is computed. The mean and fractile level control point hazard curves for seven selected spectral frequencies of 100 Hz (PGA), 25 Hz, 1 O Hz, 5 Hz, 2.5 Hz, 1 Hz, and 0.5 Hz for the CGS site are shown in Figures 2.3.7-1through2.3.7-7. Tabulated values of these control point hazard curves are provided in Tables 2.3.7-1 through 2.3.7-7. 83 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.7-1: The 5% Damped SA at 100 Hz (PGA) Control Point Hazard Curves for the CGS Site PGA Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile [g] AFE AFE AFE AFE AFE AFE 0.000100 9.362E-02 6.169E-02 7.082E-02 8.713E-02 1.122E-01 1.515E-01 0.000113 9.310E-02 6.132E-02 7.039E-02 8.670E-02 1.117E-01 1.503E-01 0.000128 9.245E-02 6.085E-02 6.986E-02 8.614E-02 1.110E-01 1.488E-01 0.000145 9.169E-02 6.031 E-02 6.924E-02 8.550E-02 1.101E-01 1.470E-01 0.000164 9.087E-02 5.973E-02 6.857E-02 8.481 E-02 1.093E-01 1.451 E-01 0.000185 9.002E-02 5.912E-02 6.788E-02 8.409E-02 1.083E-01 1.432E-01 0.000210 8.916E-02 5.851 E-02 6.717E-02 8.336E-02 1.074E-01 1.412E-01 0.000237 8.830E-02 5.789E-02 6.646E-02 8.263E-02 1.064E-01 1.392E-01 0.000268 8.744E-02 5.727E-02 6.576E-02 8.190E-02 1.055E-01 1.373E-01 0.000303 8.657E-02 5.665E-02 6.505E-02 8.117E-02 1.046E-01 1.353E-01 0.000343 8.569E-02 5.600E-02 6.432E-02 8.041 E-02 1.036E-01 1.334E-01 0.000388 8.475E-02 5.528E-02 6.352E-02 7.962E-02 1.026E-01 1.314E-01 0.000439 8.372E-02 5.444E-02 6.263E-02 7.875E-02 1.016E-01 1.294E-01 0.000497 8.255E-02 5.341 E-02 6.157E-02 7.774E-02 1.004E-01 1.272E-01 0.000562 8.117E-02 5.214E-02 6.029E-02 7.658E-02 9.901 E-02 1.249E-01 0.000636 7.958E-02 5.061 E-02 5.878E-02 7.520E-02 9.750E-02 1.224E-01 0.000719 7.777E-02 4.884E-02 5.702E-02 7.362E-02 9.580E-02 1.198E-01 0.000813 7.575E-02 4.684E-02 5.504E-02 7.180E-02 9.393E-02 1.171 E-01 0.000920 7.355E-02 4.466E-02 5.286E-02 6.975E-02 9.192E-02 1.143E-01 0.001041 7.116E-02 4.233E-02 5.047E-02 6.743E-02 8.974E-02 1.114E-01 0.001177 6.860E-02 3.987E-02 4.789E-02 6.483E-02 8.743E-02 1.085E-01 0.001332 6.589E-02 3.732E-02 4.517E-02 6.199E-02 8.499E-02 1.056E-01 0.001507 6.308E-02 3.473E-02 4.236E-02 5.896E-02 8.246E-02 1.028E-01 0.001704 6.023E-02 3.217E-02 3.954E-02 5.585E-02 7.987E-02 9.996E-02 0.001928 5.739E-02 2.970E-02 3.678E-02 5.273E-02 7.726E-02 9.714E-02 0.002181 5.459E-02 2.734E-02 3.412E-02 4.967E-02 7.465E-02 9.436E-02 0.002467 5.183E-02 2.51 OE-02 3.156E-02 4.665E-02 7.200E-02 9.156E-02 0.002791 4.907E-02 2.296E-02 2.908E-02 4.365E-02 6.927E-02 8.870E-02 0.003157 4.627E-02 2.089E-02 2.666E-02 4.063E-02 6.639E-02 8.574E-02 0.003571 4.341 E-02 1.889E-02 2.428E-02 3.757E-02 6.336E-02 8.265E-02 0.004040 4.052E-02 1.695E-02 2.195E-02 3.449E-02 6.019E-02 7.943E-02 0.004570 3.764E-02 1.511 E-02 1.970E-02 3.144E-02 5.692E-02 7.613E-02 0.005170 3.482E-02 1.339E-02 1.758E-02 2.850E-02 5.364E-02 7.281 E-02 0.005848 3.212E-02 1.181E-02 1.562E-02 2.574E-02 5.044E-02 6.953E-02 0.006615 2.957E-02 1.040E-02 1.384E-02 2.318E-02 4.733E-02 6.632E-02 0.007483 2.719E-02 9.127E-03 1.224E-02 2.083E-02 4.433E-02 6.316E-02 0.008465 2.495E-02 7.995E-03 1.080E-02 1.869E-02 4.140E-02 6.001 E-02 0.009576 2.282E-02 6.982E-03 9.503E-03 1.671 E-02 3.850E-02 5.682E-02 0.010833 2.079E-02 6.068E-03 8.330E-03 1.488E-02 3.557E-02 5.352E-02 0.012254 1.885E-02 5.243E-03 7.261 E-03 1.317E-02 3.262E-02 5.011 E-02 84 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure PGA Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile [g] AFE AFE AFE AFE AFE AFE 0.013862 1.699E-02 4.497E-03 6.290E-03 1.159E-02 2.965E-02 4.661 E-02 0.015681 1.521 E-02 3.829E-03 5.413E-03 1.013E-02 2.674E-02 4.307E-02 0.017739 1.355E-02 3.235E-03 4.627E-03 8.788E-03 2.392E-02 3.956E-02 0.020066 1.200E-02 2.712E-03 3.927E-03 7.576E-03 2.125E-02 3.613E-02 0.022699 1.055E-02 2.253E-03 3.305E-03 6.480E-03 1.873E-02 3.278E-02 0.025678 9.201 E-03 1.852E-03 2.754E-03 5.490E-03 1.638E-02 2.952E-02 0.029047 7.957E-03 1.504E-03 2.268E-03 4.601 E-03 1.419E-02 2.633E-02 0.032859 6.814E-03 1.205E-03 1.843E-03 3.810E-03 1.218E-02 2.324E-02 0.037170 5.780E-03 9.516E-04 1.478E-03 3.118E-03 1.035E-02 2.028E-02 0.042048 4.855E-03 7.400E-04 1.168E-03 2.520E-03 8.712E-03 1.749E-02 0.047565 4.038E-03 5.657E-04 9.090E-04 2.012E-03 7.260E-03 1.492E-02 0.053806 3.325E-03 4.238E-04 6.954E-04 1.587E-03 5.991 E-03 1.259E-02 0.060867 2.712E-03 3.101 E-04 5.212E-04 1.234E-03 4.896E-03 1.052E-02 0.068853 2.192E-03 2.208E-04 3.820E-04 9.473E-04 3.968E-03 8.725E-03 0.077888 1.759E-03 1.526E-04 2.733E-04 7.161 E-04 3.194E-03 7.188E-03 0.088108 1.403E-03 1.022E-04 1.904E-04 5.328E-04 2.556E-03 5.888E-03 0.099670 1.109E-03 6.621 E-05 1.290E-04 3.889E-04 2.029E-03 4.789E-03 0.112748 8.667E-04 4.136E-05 8.472E-05 2.774E-04 1.593E-03 3.853E-03 0.127542 6.667E-04 2.481 E-05 5.365E-05 1.919E-04 1.229E-03 3.055E-03 0.144278 5.020E-04 1.421 E-05 3.251 E-05 1.277E-04 9.250E-04 2.373E-03 0.163210 3.680E-04 7.699E-06 1.867E-05 8.093E-05 6.736E-04 1.796E-03 0.184625 2.616E-04 3.907E-06 1.007E-05 4.843E-05 4.711 E-04 1.319E-03 0.208851 1.798E-04 1.841 E-06 5.064E-06 2.720E-05 3.147E-04 9.369E-04 0.236256 1.196E-04 8.003E-07 2.361 E-06 1.430E-05 2.004E-04 6.430E-04 0.267257 7.693E-05 3.204E-07 1.021 E-06 7.045E-06 1.215E-04 4.256E-04 0.302325 4.785E-05 1.185E-07 4.106E-07 3.262E-06 7.000E-05 2.709E-04 0.341995 2.869E-05 4.074E-08 1.545E-07 1.425E-06 3.830E-05 1.649E-04 0.386871 1.650E-05 1.312E-08 5.471 E-08 5.875E-07 1.983E-05 9.554E-05 0.437634 9.059E-06 3.974E-09 1.825E-08 2.285E-07 9.677E-06 5.234E-05 0.495059 4.720E-06 1.132E-09 5.726E-09 8.356E-08 4.436E-06 2.699E-05 0.560020 2.325E-06 3.023E-10 1.683E-09 2.862E-08 1.904E-06 1.304E-05 0.633503 1.079E-06 7.523E-11 4.616E-10 9.152E-09 7.639E-07 5.897E-06 0.716629 4.717E-07 1.738E-11 1.176E-10 2.728E-09 2.859E-07 2.489E-06 0.810663 1.941 E-07 3.712E-12 2.778E-11 7.569E-10 9.967E-08 9.797E-07 0.917036 7.559E-08 7.313E-13 6.078E-12 1.956E-10 3.234E-08 3.599E-07 1.037366 2.809E-08 1.330E-13 1.233E-12 4.715E-11 9.769E-09 1.238E-07 1.173485 1.011 E-08 2.237E-14 2.325E-13 1.061 E-11 2.752E-09 4.022E-08 1.327466 3.585E-09 3.488E-15 4.085E-14 2.236E-12 7.266E-10 1.249E-08 1.501652 1.269E-09 5.062E-16 6.709E-15 4.426E-13 1.812E-10 3.766E-09 1.698694 4.487E-10 6.861 E-17 1.036E-15 8.282E-14 4.321E-11 1.122E-09 1.921589 1.562E-10 8.744E-18 1.515E-16 1.478E-14 1.000E-11 3.322E-10 2.173734 5.225E-11 1.056E-18 2.119E-17 2.544E-15 2.279E-12 9.717E-11 85 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure PGA Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile [g] AFE AFE AFE AFE AFE AFE 2.458964 1.639E-11 1.223E-19 2.868E-18 4.274E-16 5.148E-13 2.753E-11 2.781622 4.718E-12 1.377E-20 3.796E-19 7.071 E-17 1.144E-13 7.373E-12 3.146617 1.228E-12 1.527E-21 4.951 E-20 1.157E-17 2.460E-14 1.824E-12 3.559503 2.857E-13 1.675E-22 6.368E-21 1.864E-18 4.998E-15 4.093E-13 4.026569 5.893E-14 1.818E-23 8.045E-22 2.915E-19 9.383E-16 8.238E-14 4.554923 1.074E-14 1.942E-24 9.907E-23 4.347E-20 1.602E-16 1.475E-14 5.152606 1.727E-15 2.020E-25 1.179E-23 6.070E-21 2.460E-17 2.339E-15 5.828714 2.453E-16 2.050E-26 1.344E-24 7.830E-22 3.384E-18 3.290E-16 6.593533 3.093E-17 1.987E-27 1.451 E-25 9.260E-23 4.173E-19 4.118E-17 7.458715 3.488E-18 1.866E-28 1.482E-26 1.003E-23 4.635E-20 4.622E-18 8.437425 3.554E-19 1.736E-29 1.441 E-27 1.000E-24 4.676E-21 4.690E-19 9.544557 3.309E-20 1.517E-30 1.308E-28 9.210E-26 4.327E-22 4.355E-20 10.796952 2.855E-21 1.825E-31 1.330E-29 8.312E-27 3.749E-23 3.754E-21 12.213694 2.302E-22 O.OOOE+OO 3.660E-31 5.048E-28 2.860E-24 2.998E-22 13.816336 1.768E-23 O.OOOE+OO 2.791 E-32 3.847E-29 2.185E-25 2.298E-23 15.629272 1.286E-24 O.OOOE+OO 1.998E-33 2.750E-30 1.571 E-26 1.664E-24 17.680094 8.285E-26 O.OOOE+OO 1.220E-34 1.672E-31 9.715E-28 1.052E-25 20.000000 O.OOOE+OO O.OOOE+OO O.OOOE+OO O.OOOE+OO O.OOOE+OO O.OOOE+OO 86 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.7-2: The 5% damped SA at 25 Hz Control Point Hazard Curves for the CGS Site PSA Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile [g] AFE AFE AFE AFE AFE AFE 0.000100 9.330E-02 6.144E-02 7.058E-02 8.690E-02 1.119E-01 1.508E-01 0.000113 9.282E-02 6.103E-02 7.019E-02 8.650E-02 1.115E-01 1.496E-01 0.000128 9.224E-02 6.054E-02 6.972E-02 8.604E-02 1.109E-01 1.482E-01 0.000145 9.160E-02 6.000E-02 6.920E-02 8.552E-02 1.102E-01 1.467E-01 0.000164 9.091 E-02 5.941 E-02 6.863E-02 8.497E-02 1.095E-01 1.450E-01 0.000185 9.019E-02 5.882E-02 6.806E-02 8.439E-02 1.087E-01 1.433E-01 0.000210 8.947E-02 5.820E-02 6.747E-02 8.381 E-02 1.080E-01 1.415E-01 0.000237 8.874E-02 5.759E-02 6.687E-02 8.322E-02 1.072E-01 1.398E-01 0.000268 8.801 E-02 5.697E-02 6.628E-02 8.262E-02 1.064E-01 1.381 E-01 0.000303 8.726E-02 5.633E-02 6.565E-02 8.201 E-02 1.057E-01 1.364E-01 0.000343 8.647E-02 5.565E-02 6.498E-02 8.137E-02 1.049E-01 1.346E-01 0.000388 8.562E-02 5.489E-02 6.423E-02 8.066E-02 1.040E-01 1.328E-01 0.000439 8.466E-02 5.401 E-02 6.333E-02 7.986E-02 1.030E-01 1.309E-01 0.000497 8.355E-02 5.297E-02 6.227E-02 7.892E-02 1.020E-01 1.290E-01 0.000562 8.227E-02 5.174E-02 6.100E-02 7.784E-02 1.008E-01 1.269E-01 0.000636 8.082E-02 5.031 E-02 5.951 E-02 7.658E-02 9.947E-02 1.247E-01 0.000719 7.919E-02 4.867E-02 5.781 E-02 7.515E-02 9.798E-02 1.223E-01 0.000813 7.739E-02 4.684E-02 5.589E-02 7.352E-02 9.636E-02 1.198E-01 0.000920 7.540E-02 4.481 E-02 5.377E-02 7.169E-02 9.458E-02 1.173E-01 0.001041 7.324E-02 4.259E-02 5.146E-02 6.966E-02 9.265E-02 1.146E-01 0.001177 7.093E-02 4.021 E-02 4.898E-02 6.745E-02 9.059E-02 1.118E-01 0.001332 6.850E-02 3.774E-02 4.639E-02 6.509E-02 8.841 E-02 1.090E-01 0.001507 6.599E-02 3.522E-02 4.374E-02 6.262E-02 8.616E-02 1.061 E-01 0.001704 6.344E-02 3.272E-02 4.109E-02 6.009E-02 8.385E-02 1.032E-01 0.001928 6.088E-02 3.028E-02 3.849E-02 5.752E-02 8.149E-02 1.003E-01 0.002181 5.831 E-02 2.794E-02 3.594E-02 5.492E-02 7.907E-02 9.735E-02 0.002467 5.569E-02 2.568E-02 3.345E-02 5.225E-02 7.657E-02 9.434E-02 0.002791 5.302E-02 2.351 E-02 3.099E-02 4.948E-02 7.395E-02 9.121 E-02 0.003157 5.027E-02 2.141E-02 2.856E-02 4.660E-02 7.118E-02 8.795E-02 0.003571 4.745E-02 1.938E-02 2.617E-02 4.361 E-02 6.827E-02 8.455E-02 0.004040 4.459E-02 1.745E-02 2.383E-02 4.055E-02 6.525E-02 8.105E-02 0.004570 4.174E-02 1.562E-02 2.159E-02 3.751 E-02 6.217E-02 7.750E-02 0.005170 3.894E-02 1.392E-02 1.947E-02 3.454E-02 5.908E-02 7.395E-02 0.005848 3.625E-02 1.237E-02 1.749E-02 3.170E-02 5.604E-02 7.045E-02 0.006615 3.367E-02 1.096E-02 1.568E-02 2.900E-02 5.304E-02 6.699E-02 0.007483 3.120E-02 9.681 E-03 1.401 E-02 2.647E-02 5.009E-02 6.356E-02 0.008465 2.884E-02 8.533E-03 1.248E-02 2.409E-02 4.714E-02 6.011 E-02 0.009576 2.656E-02 7.494E-03 1.108E-02 2.183E-02 4.416E-02 5.662E-02 0.010833 2.435E-02 6.552E-03 9.785E-03 1.969E-02 4.114E-02 5.304E-02 0.012254 2.221 E-02 5.700E-03 8.595E-03 1.767E-02 3.81 OE-02 4.942E-02 87 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure PSA Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile [g] AFE AFE AFE AFE AFE AFE 0.013862 2.016E-02 4.934E-03 7.507E-03 1.577E-02 3.507E-02 4.579E-02 0.015681 1.822E-02 4.249E-03 6.521 E-03 1.400E-02 3.212E-02 4.221 E-02 0.017739 1.640E-02 3.643E-03 5.637E-03 1.237E-02 2.927E-02 3.875E-02 0.020066 1.471 E-02 3.11 OE-03 4.853E-03 1.089E-02 2.657E-02 3.544E-02 0.022699 1.314E-02 2.644E-03 4.160E-03 9.552E-03 2.402E-02 3.229E-02 0.025678 1.169E-02 2.234E-03 3.548E-03 8.337E-03 2.159E-02 2.927E-02 0.029047 1.034E-02 1.875E-03 3.006E-03 7.232E-03 1.928E-02 2.637E-02 0.032859 9.083E-03 1.559E-03 2.528E-03 6.230E-03 1.709E-02 2.360E-02 0.037170 7.918E-03 1.283E-03 2.107E-03 5.325E-03 1.503E-02 2.094E-02 0.042048 6.852E-03 1.043E-03 1.740E-03 4.517E-03 1.31 OE-02 1.845E-02 0.047565 5.887E-03 8.373E-04 1.424E-03 3.803E-03 1.134E-02 1.613E-02 0.053806 5.025E-03 6.640E-04 1.154E-03 3.181 E-03 9.748E-03 1.401 E-02 0.060867 4.263E-03 5.193E-04 9.257E-04 2.642E-03 8.331 E-03 1.210E-02 0.068853 3.595E-03 4.002E-04 7.344E-04 2.180E-03 7.081 E-03 1.040E-02 0.077888 3.013E-03 3.033E-04 5.752E-04 1.785E-03 5.986E-03 8.878E-03 0.088108 2.509E-03 2.256E-04 4.438E-04 1.447E-03 5.031 E-03 7.541 E-03 0.099670 2.074E-03 1.644E-04 3.367E-04 1.162E-03 4.202E-03 6.365E-03 0.112748 1.702E-03 1.171 E-04 2.507E-04 9.221 E-04 3.483E-03 5.335E-03 0.127542 1.384E-03 8.143E-05 1.828E-04 7.214E-04 2.863E-03 4.436E-03 0.144278 1.114E-03 5.51 SE-05 1.303E-04 5.549E-04 2.329E-03 3.654E-03 0.163210 8.860E-04 3.632E-05 9.053E-05 4.185E-04 1.870E-03 2.975E-03 0.184625 6.940E-04 2.322E-05 6.11 SE-05 3.083E-04 1.479E-03 2.389E-03 0.208851 5.343E-04 1.436E-05 4.002E-05 2.210E-04 1.150E-03 1.888E-03 0.236256 4.034E-04 8.579E-06 2.533E-05 1.539E-04 8.752E-04 1.464E-03 0.267257 2.980E-04 4.939E-06 1.547E-05 1.038E-04 6.515E-04 1.112E-03 0.302325 2.152E-04 2.733E-06 9.094E-06 6.777E-05 4.732E-04 8.250E-04 0.341995 1.516E-04 1.453E-06 5.148E-06 4.275E-05 3.347E-04 5.973E-04 0.386871 1.041 E-04 7.41 SE-07 2.805E-06 2.608E-05 2.302E-04 4.212E-04 0.437634 6.954E-05 3.636E-07 1.472E-06 1.538E-05 1.538E-04 2.889E-04 0.495059 4.521 E-05 1.714E-07 7.441 E-07 8.765E-06 9.961 E-05 1.926E-04 0.560020 2.857E-05 7.778E-08 3.631 E-07 4.829E-06 6.254E-05 1.246E-04 0.633503 1.753E-05 3.401 E-08 1.709E-07 2.570E-06 3.800E-05 7.823E-05 0.716629 1.045E-05 1.433E-08 7.756E-08 1.320E-06 2.235E-05 4.765E-05 0.810663 6.056E-06 5.816E-09 3.392E-08 6.537E-07 1.272E-05 2.818E-05 0.917036 3.416E-06 2.271 E-09 1.428E-08 3.122E-07 7.022E-06 1.621 E-05 1.037366 1.879E-06 8.519E-10 5.778E-09 1.439E-07 3.761 E-06 9.076E-06 1.173485 1.011 E-06 3.065E-10 2.246E-09 6.406E-08 1.961 E-06 4.963E-06 1.327466 5.337E-07 1.057E-10 8.396E-10 2.764E-08 9.974E-07 2.658E-06 1.501652 2.776E-07 3.499E-11 3.025E-10 1.160E-08 4.968E-07 1.399E-06 1.698694 1.427E-07 1 .113E-11 1.054E-10 4.751 E-09 2.430E-07 7.251 E-07 1.921589 7.284E-08 3.422E-12 3.575E-11 1.909E-09 1.171 E-07 3.717E-07 2.173734 3.700E-08 1.022E-12 1.184E-11 7.543E-10 5.579E-08 1.889E-07 88 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure PSA Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile [g] AFE AFE AFE AFE AFE AFE 2.458964 1.878E-08 2.981 E-13 3.856E-12 2.940E-10 2.635E-08 9.556E-08 2.781622 9.537E-09 8.557E-14 1.239E-12 1.133E-10 1.238E-08 4.822E-08 3.146617 4.855E-09 2.425E-14 3.932E-13 4.336E-11 5.796E-09 2.429E-08 3.559503 2.474E-09 6.804E-15 1.237E-13 1.651 E-11 2.713E-09 1.222E-08 4.026569 1.260E-09 1.891 E-15 3.862E-14 6.280E-12 1.270E-09 6.133E-09 4.554923 6.382E-10 5.214E-16 1.202E-14 2.398E-12 5.929E-10 3.060E-09 5.152606 3.202E-10 1.429E-16 3.743E-15 9.218E-13 2.758E-10 1.512E-09 5.828714 1.583E-10 3.897E-17 1.172E-15 3.568E-13 1.272E-10 7.366E-10 6.593533 7.671E-11 1.061 E-17 3.709E-16 1.392E-13 5.793E-11 3.520E-10 7.458715 3.627E-11 2.891 E-18 1.188E-16 5.445E-14 2.590E-11 1.642E-10 8.437425 1.666E-11 7.895E-19 3.862E-17 2.128E-14 1.133E-11 7.455E-11 9.544557 7.411 E-12 2.164E-19 1.270E-17 8.250E-15 4.818E-12 3.278E-11 10.796952 3.180E-12 5.961 E-20 4.205E-18 3.155E-15 1.989E-12 1.392E-11 12.213694 1.313E-12 1.649E-20 1.393E-18 1.183E-15 7.936E-13 5.698E-12 13.816336 5.210E-13 4.586E-21 4.585E-19 4.326E-16 3.052E-13 2.241 E-12 15.629272 1.981E-13 1.280E-21 1.489E-19 1.537E-16 1.130E-13 8.456E-13 17.680094 7.213E-14 3.578E-22 4.748E-20 5.281 E-17 4.017E-14 3.059E-13 20.000000 2.514E-14 9.991 E-23 1.477E-20 1.752E-17 1.370E-14 1.059E-13 89 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.7-3: The 5% Damped SA at 10 Hz Control Point Hazard Curves for the CGS Site PSA Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile [g] AFE AFE AFE AFE AFE AFE 0.000100 9.413E-02 6.189E-02 7.105E-02 8.743E-02 1.128E-01 1.525E-01 0.000113 9.383E-02 6.172E-02 7.086E-02 8.718E-02 1.124E-01 1.517E-01 0.000128 9.340E-02 6.148E-02 7.058E-02 8.684E-02 1.118E-01 1.505E-01 0.000145 9.286E-02 6.117E-02 7.023E-02 8.641 E-02 1.111E-01 1.490E-01 0.000164 9.222E-02 6.081 E-02 6.982E-02 8.590E-02 1.103E-01 1.473E-01 0.000185 9.154E-02 6.042E-02 6.937E-02 8.534E-02 1.094E-01 1.454E-01 0.000210 9.082E-02 6.001 E-02 6.890E-02 8.477E-02 1.085E-01 1.434E-01 0.000237 9.009E-02 5.959E-02 6.842E-02 8.418E-02 1.075E-01 1.414E-01 0.000268 8.936E-02 5.91 SE-02 6.794E-02 8.359E-02 1.066E-01 1.395E-01 0.000303 8.862E-02 5.876E-02 6.746E-02 8.300E-02 1.057E-01 1.375E-01 0.000343 8.789E-02 5.834E-02 6.698E-02 8.241 E-02 1.047E-01 1.356E-01 0.000388 8.715E-02 5.790E-02 6.649E-02 8.180E-02 1.038E-01 1.337E-01 0.000439 8.637E-02 5.742E-02 6.596E-02 8.117E-02 1.028E-01 1.316E-01 0.000497 8.551 E-02 5.687E-02 6.535E-02 8.047E-02 1.018E-01 1.296E-01 0.000562 8.453E-02 5.619E-02 6.463E-02 7.965E-02 1.008E-01 1.274E-01 0.000636 8.338E-02 5.534E-02 6.375E-02 7.868E-02 9.957E-02 1.249E-01 0.000719 8.203E-02 5.429E-02 6.268E-02 7.754E-02 9.828E-02 1.221 E-01 0.000813 8.047E-02 5.304E-02 6.142E-02 7.621 E-02 9.682E-02 1.192E-01 0.000920 7.872E-02 5.160E-02 5.996E-02 7.469E-02 9.519E-02 1.160E-01 0.001041 7.673E-02 4.994E-02 5.828E-02 7.294E-02 9.333E-02 1.127E-01 0.001177 7.451 E-02 4.804E-02 5.635E-02 7.095E-02 9.119E-02 1.093E-01 0.001332 7.202E-02 4.591 E-02 5.416E-02 6.869E-02 8.874E-02 1.057E-01 0.001507 6.931 E-02 4.358E-02 5.174E-02 6.618E-02 8.599E-02 1.020E-01 0.001704 6.642E-02 4.11 OE-02 4.916E-02 6.350E-02 8.300E-02 9.827E-02 0.001928 6.346E-02 3.858E-02 4.650E-02 6.072E-02 7.989E-02 9.455E-02 0.002181 6.049E-02 3.608E-02 4.385E-02 5.793E-02 7.673E-02 9.088E-02 0.002467 5.760E-02 3.368E-02 4.129E-02 5.519E-02 7.362E-02 8.730E-02 0.002791 5.480E-02 3.141 E-02 3.884E-02 5.255E-02 7.059E-02 8.384E-02 0.003157 5.213E-02 2.927E-02 3.651 E-02 5.003E-02 6.766E-02 8.0SOE-02 0.003571 4.957E-02 2.727E-02 3.432E-02 4.760E-02 6.484E-02 7.728E-02 0.004040 4.711 E-02 2.539E-02 3.224E-02 4.527E-02 6.209E-02 7.414E-02 0.004570 4.471 E-02 2.360E-02 3.024E-02 4.299E-02 5.939E-02 7.104E-02 0.005170 4.234E-02 2.187E-02 2.828E-02 4.072E-02 5.666E-02 6.791 E-02 0.005848 3.994E-02 2.01 SE-02 2.634E-02 3.842E-02 5.384E-02 6.467E-02 0.006615 3.748E-02 1.851 E-02 2.439E-02 3.606E-02 5.090E-02 6.130E-02 0.007483 3.498E-02 1.686E-02 2.245E-02 3.364E-02 4.784E-02 5.779E-02 0.008465 3.245E-02 1.525E-02 2.051 E-02 3.119E-02 4.471 E-02 5.419E-02 0.009576 2.996E-02 1.370E-02 1.863E-02 2.876E-02 4.156E-02 5.057E-02 0.010833 2.752E-02 1.225E-02 1.684E-02 2.637E-02 3.846E-02 4.700E-02 0.012254 2.518E-02 1.091 E-02 1.513E-02 2.405E-02 3.543E-02 4.352E-02 90 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure PSA Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile [g] AFE AFE AFE AFE AFE AFE 0.013862 2.294E-02 9.670E-03 1.354E-02 2.183E-02 3.251 E-02 4.017E-02 0.015681 2.082E-02 8.546E-03 1.206E-02 1.970E-02 2.972E-02 3.695E-02 0.017739 1.882E-02 7.528E-03 1.069E-02 1.770E-02 2.707E-02 3.389E-02 0.020066 1.696E-02 6.608E-03 9.438E-03 1.584E-02 2.456E-02 3.098E-02 0.022699 1.522E-02 5.778E-03 8.304E-03 1.411 E-02 2.220E-02 2.823E-02 0.025678 1.361 E-02 5.028E-03 7.273E-03 1.253E-02 1.998E-02 2.561 E-02 0.029047 1.210E-02 4.348E-03 6.339E-03 1.107E-02 1.788E-02 2.312E-02 0.032859 1.069E-02 3.732E-03 5.490E-03 9.727E-03 1.590E-02 2.074E-02 0.037170 9.392E-03 3.176E-03 4.722E-03 8.495E-03 1.405E-02 1.849E-02 0.042048 8.196E-03 2.680E-03 4.032E-03 7.372E-03 1.233E-02 1.638E-02 0.047565 7.105E-03 2.243E-03 3.418E-03 6.358E-03 1.076E-02 1.443E-02 0.053806 6.125E-03 1.862E-03 2.877E-03 5.450E-03 9.334E-03 1.264E-02 0.060867 5.252E-03 1.535E-03 2.404E-03 4.646E-03 8.064E-03 1.101 E-02 0.068853 4.482E-03 1.256E-03 1.997E-03 3.938E-03 6.939E-03 9.555E-03 0.077888 3.806E-03 1.021 E-03 1.646E-03 3.321 E-03 5.948E-03 8.249E-03 0.088108 3.215E-03 8.217E-04 1.347E-03 2.783E-03 5.077E-03 7.087E-03 0.099670 2.701 E-03 6.544E-04 1.093E-03 2.318E-03 4.311 E-03 6.058E-03 0.112748 2.255E-03 5.143E-04 8.779E-04 1.916E-03 3.639E-03 5.150E-03 0.127542 1.869E-03 3.982E-04 6.974E-04 1.571 E-03 3.051 E-03 4.351 E-03 0.144278 1.538E-03 3.033E-04 5.471 E-04 1.277E-03 2.539E-03 3.652E-03 0.163210 1.255E-03 2.268E-04 4.232E-04 1.027E-03 2.095E-03 3.041 E-03 0.184625 1.012E-03 1.661 E-04 3.219E-04 8.161 E-04 1.711 E-03 2.508E-03 0.208851 8.068E-04 1.190E-04 2.401 E-04 6.390E-04 1.381 E-03 2.046E-03 0.236256 6.339E-04 8.298E-05 1.751 E-04 4.918E-04 1.099E-03 1.647E-03 0.267257 4.900E-04 5.634E-05 1.247E-04 3.713E-04 8.607E-04 1.307E-03 0.302325 3.721 E-04 3.714E-05 8.641 E-05 2.743E-04 6.625E-04 1.022E-03 0.341995 2.774E-04 2.377E-05 5.830E-05 1.982E-04 5.004E-04 7.850E-04 0.386871 2.027E-04 1.476E-05 3.825E-05 1.398E-04 3.704E-04 5.920E-04 0.437634 1.451 E-04 8.904E-06 2.441 E-05 9.622E-05 2.683E-04 4.378E-04 0.495059 1.017E-04 5.221 E-06 1.515E-05 6.454E-05 1.899E-04 3.169E-04 0.560020 6.969E-05 2.977E-06 9.150E-06 4.219E-05 1.313E-04 2.244E-04 0.633503 4.668E-05 1.651 E-06 5.373E-06 2.685E-05 8.852E-05 1.552E-04 0.716629 3.055E-05 8.900E-07 3.067E-06 1.663E-05 5.820E-05 1.048E-04 0.810663 1.953E-05 4.664E-07 1.703E-06 1.002E-05 3.729E-05 6.906E-05 0.917036 1.220E-05 2.374E-07 9.187E-07 5.876E-06 2.330E-05 4.444E-05 1.037366 7.450E-06 1.174E-07 4.818E-07 3.353E-06 1.419E-05 2.792E-05 1.173485 4.449E-06 5.635E-08 2.459E-07 1.865E-06 8.440E-06 1.714E-05 1.327466 2.602E-06 2.632E-08 1.222E-07 1.011 E-06 4.901 E-06 1.029E-05 1.501652 1.492E-06 1.196E-08 5.922E-08 5.354E-07 2.782E-06 6.045E-06 1.698694 8.394E-07 5.301 E-09 2.SOOE-08 2.769E-07 1.545E-06 3.478E-06 1.921589 4.643E-07 2.294E-09 1.293E-08 1.401 E-07 8.404E-07 1.963E-06 2.173734 2.529E-07 9.703E-10 5.842E-09 6.933E-08 4.484E-07 1.089E-06 91 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure PSA Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile [g] AFE AFE AFE AFE AFE AFE 2.458964 1.359E-07 4.011E-10 2.580E-09 3.362E-08 2.350E-07 5.951 E-07 2.781622 7.225E-08 1.622E-10 1.115E-09 1.599E-08 1.213E-07 3.211 E-07 3.146617 3.813E-08 6.412E-11 4.722E-10 7.472E-09 6.181E-08 1.716E-07 3.559503 2.003E-08 2.482E-11 1.959E-10 3.437E-09 3.117E-08 9.102E-08 4.026569 1.050E-08 9.407E-12 7.978E-11 1.560E-09 1.561 E-08 4.806E-08 4.554923 5.498E-09 3.494E-12 3.195E-11 7.008E-10 7.783E-09 2.529E-08 5.152606 2.876E-09 1.274E-12 1.261 E-11 3.125E-10 3.867E-09 1.326E-08 5.828714 1.501 E-09 4.568E-13 4.919E-12 1.387E-10 1.915E-09 6.920E-09 6.593533 7.789E-10 1.613E-13 1.902E-12 6.130E-11 9.442E-10 3.584E-09 7.458715 4.005E-10 5.629E-14 7.309E-13 2.703E-11 4.623E-10 1.836E-09 8.437425 2.031 E-10 1.945E-14 2.798E-13 1.187E-11 2.240E-10 9.269E-10 9.544557 1.012E-10 6.676E-15 1.069E-13 5.179E-12 1.070E-10 4.591 E-10 10.796952 4.931E-11 2.281 E-15 4.077E-14 2.239E-12 5.015E-11 2.224E-10 12.213694 2.341 E-11 7.764E-16 1.548E-14 9.548E-13 2.299E-11 1.050E-10 13.816336 1.080E-11 2.632E-16 5.843E-15 4.002E-13 1.027E-11 4.811E-11 15.629272 4.823E-12 8.881 E-17 2.183E-15 1.641 E-13 4.461 E-12 2.137E-11 17.680094 2.082E-12 2.975E-17 8.042E-16 6.567E-14 1.876E-12 9.172E-12 20.000000 8.661 E-13 9.865E-18 2.911 E-16 2.556E-14 7.626E-13 3.797E-12 92 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.7-4: The 5% Damped SA at 5 Hz Control Point Hazard Curves for the CGS Site PSA Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile [g] AFE AFE AFE AFE AFE AFE 0.000100 9.491 E-02 6.188E-02 7.104E-02 8.741 E-02 1.128E-01 1.527E-01 0.000113 9.491 E-02 6.188E-02 7.104E-02 8.741 E-02 1.128E-01 1.527E-01 0.000128 9.490E-02 6.188E-02 7.104E-02 8.740E-02 1.128E-01 1.527E-01 0.000145 9.489E-02 6.187E-02 7.103E-02 8.740E-02 1.128E-01 1.527E-01 0.000164 9.488E-02 6.186E-02 7.102E-02 8.739E-02 1.128E-01 1.526E-01 0.000185 9.484E-02 6.185E-02 7.100E-02 8.736E-02 1.127E-01 1.525E-01 0.000210 9.477E-02 6.182E-02 7.097E-02 8.732E-02 1.126E-01 1.524E-01 0.000237 9.465E-02 6.177E-02 7.092E-02 8.725E-02 1.125E-01 1.520E-01 0.000268 9.449E-02 6.170E-02 7.083E-02 8.715E-02 1.123E-01 1.516E-01 0.000303 9.424E-02 6.159E-02 7.071 E-02 8.700E-02 1.120E-01 1.510E-01 0.000343 9.394E-02 6.146E-02 7.056E-02 8.681 E-02 1.117E-01 1.502E-01 0.000388 9.357E-02 6.130E-02 7.038E-02 8.659E-02 1.112E-01 1.492E-01 0.000439 9.317E-02 6.112E-02 7.017E-02 8.634E-02 1.107E-01 1.481 E-01 0.000497 9.272E-02 6.092E-02 6.995E-02 8.606E-02 1.102E-01 1.470E-01 0.000562 9.225E-02 6.072E-02 6.971 E-02 8.577E-02 1.096E-01 1.457E-01 0.000636 9.177E-02 6.050E-02 6.947E-02 8.548E-02 1.091 E-01 1.444E-01 0.000719 9.128E-02 6.029E-02 6.922E-02 8.517E-02 1.085E-01 1.432E-01 0.000813 9.078E-02 6.007E-02 6.897E-02 8.485E-02 1.079E-01 1.419E-01 0.000920 9.026E-02 5.983E-02 6.869E-02 8.451 E-02 1.073E-01 1.405E-01 0.001041 8.968E-02 5.956E-02 6.839E-02 8.414E-02 1.066E-01 1.391 E-01 0.001177 8.904E-02 5.925E-02 6.803E-02 8.370E-02 1.059E-01 1.375E-01 0.001332 8.828E-02 5.887E-02 6.759E-02 8.316E-02 1.051 E-01 1.358E-01 0.001507 8.737E-02 5.839E-02 6.705E-02 8.250E-02 1.042E-01 1.337E-01 0.001704 8.629E-02 5.778E-02 6.636E-02 8.166E-02 1.030E-01 1.313E-01 0.001928 8.498E-02 5.704E-02 6.551 E-02 8.063E-02 1.017E-01 1.285E-01 0.002181 8.343E-02 5.61 OE-02 6.447E-02 7.938E-02 1.001 E-01 1.254E-01 0.002467 8.163E-02 5.495E-02 6.319E-02 7.787E-02 9.816E-02 1.220E-01 0.002791 7.956E-02 5.355E-02 6.166E-02 7.606E-02 9.595E-02 1.183E-01 0.003157 7.721 E-02 5.189E-02 5.985E-02 7.397E-02 9.341 E-02 1.143E-01 0.003571 7.459E-02 4.997E-02 5.777E-02 7.158E-02 9.054E-02 1.101 E-01 0.004040 7.175E-02 4.784E-02 5.547E-02 6.894E-02 8.738E-02 1.058E-01 0.004570 6.875E-02 4.553E-02 5.300E-02 6.612E-02 8.402E-02 1.014E-01 0.005170 6.568E-02 4.315E-02 5.044E-02 6.320E-02 8.054E-02 9.704E-02 0.005848 6.260E-02 4.076E-02 4.787E-02 6.025E-02 7.703E-02 9.270E-02 0.006615 5.957E-02 3.842E-02 4.534E-02 5.735E-02 7.356E-02 8.847E-02 0.007483 5.664E-02 3.615E-02 4.288E-02 5.452E-02 7.018E-02 8.438E-02 0.008465 5.380E-02 3.398E-02 4.052E-02 5.179E-02 6.690E-02 8.043E-02 0.009576 5.105E-02 3.191 E-02 3.825E-02 4.915E-02 6.372E-02 7.661 E-02 0.010833 4.838E-02 2.992E-02 3.604E-02 4.658E-02 6.062E-02 7.287E-02 0.012254 4.575E-02 2.798E-02 3.388E-02 4.405E-02 5.755E-02 6.919E-02 93 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure PSA Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile [g] AFE AFE AFE AFE AFE AFE 0.013862 4.312E-02 2.608E-02 3.173E-02 4.152E-02 5.448E-02 6.550E-02 0.015681 4.046E-02 2.41 SE-02 2.957E-02 3.897E-02 5.138E-02 6.177E-02 0.017739 3.778E-02 2.231 E-02 2.740E-02 3.639E-02 4.823E-02 5.799E-02 0.020066 3.508E-02 2.044E-02 2.522E-02 3.379E-02 4.504E-02 5.418E-02 0.022699 3.238E-02 1.861 E-02 2.307E-02 3.119E-02 4.185E-02 5.036E-02 0.025678 2.973E-02 1.684E-02 2.096E-02 2.865E-02 3.867E-02 4.659E-02 0.029047 2.716E-02 1.514E-02 1.894E-02 2.617E-02 3.555E-02 4.291 E-02 0.032859 2.469E-02 1.353E-02 1.702E-02 2.378E-02 3.252E-02 3.934E-02 0.037170 2.235E-02 1.203E-02 1.522E-02 2.151 E-02 2.959E-02 3.593E-02 0.042048 2.015E-02 1.064E-02 1.355E-02 1.937E-02 2.679E-02 3.269E-02 0.047565 1.808E-02 9.366E-03 1.200E-02 1.736E-02 2.415E-02 2.962E-02 0.053806 1.616E-02 8.202E-03 1.058E-02 1.548E-02 2.166E-02 2.674E-02 0.060867 1.437E-02 7.145E-03 9.280E-03 1.373E-02 1.934E-02 2.404E-02 0.068853 1.271 E-02 6.192E-03 8.098E-03 1.211 E-02 1.719E-02 2.150E-02 0.077888 1.119E-02 5.336E-03 7.027E-03 1.062E-02 1.520E-02 1.915E-02 0.088108 9.792E-03 4.571 E-03 6.062E-03 9.262E-03 1.337E-02 1.696E-02 0.099670 8.522E-03 3.894E-03 5.201 E-03 8.025E-03 1.171 E-02 1.494E-02 0.112748 7.377E-03 3.298E-03 4.437E-03 6.916E-03 1.020E-02 1.311 E-02 0.127542 6.354E-03 2.779E-03 3.766E-03 5.928E-03 8.851 E-03 1.145E-02 0.144278 5.446E-03 2.329E-03 3.181 E-03 5.055E-03 7.643E-03 9.944E-03 0.163210 4.644E-03 1.941 E-03 2.672E-03 4.289E-03 6.567E-03 8.597E-03 0.184625 3.939E-03 1.607E-03 2.233E-03 3.618E-03 5.613E-03 7.390E-03 0.208851 3.321 E-03 1.322E-03 1.853E-03 3.034E-03 4.770E-03 6.316E-03 0.236256 2.782E-03 1.078E-03 1.527E-03 2.528E-03 4.027E-03 5.364E-03 0.267257 2.314E-03 8.719E-04 1.249E-03 2.090E-03 3.376E-03 4.524E-03 0.302325 1.910E-03 6.984E-04 1.011 E-03 1.714E-03 2.809E-03 3.789E-03 0.341995 1.564E-03 5.537E-04 8.107E-04 1.394E-03 2.318E-03 3.149E-03 0.386871 1.269E-03 4.338E-04 6.426E-04 1.123E-03 1.896E-03 2.597E-03 0.437634 1.020E-03 3.356E-04 5.033E-04 8.953E-04 1.536E-03 2.123E-03 0.495059 8.115E-04 2.560E-04 3.890E-04 7.058E-04 1.231 E-03 1.719E-03 0.560020 6.381 E-04 1.923E-04 2.964E-04 5.497E-04 9.753E-04 1.377E-03 0.633503 4.954E-04 1.422E-04 2.224E-04 4.224E-04 7.630E-04 1.091 E-03 0.716629 3.794E-04 1.032E-04 1.642E-04 3.199E-04 5.888E-04 8.538E-04 0.810663 2.861 E-04 7.344E-05 1.191 E-04 2.384E-04 4.476E-04 6.584E-04 0.917036 2.123E-04 5.123E-05 8.471 E-05 1.747E-04 3.348E-04 5.000E-04 1.037366 1.548E-04 3.497E-05 5.91 OE-05 1.256E-04 2.462E-04 3.734E-04 1.173485 1.108E-04 2.334E-05 4.036E-05 8.850E-05 1.776E-04 2.738E-04 1.327466 7.773E-05 1.522E-05 2.696E-05 6.110E-05 1.257E-04 1.969E-04 1.501652 5.346E-05 9.692E-06 1.760E-05 4.126E-05 8.719E-05 1.389E-04 1.698694 3.599E-05 6.025E-06 1.122E-05 2.724E-05 5.920E-05 9.582E-05 1.921589 2.371 E-05 3.654E-06 6.985E-06 1.757E-05 3.932E-05 6.470E-05 2.173734 1.528E-05 2.162E-06 4.243E-06 1.107E-05 2.554E-05 4.272E-05 94 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure PSA Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile [g] AFE AFE AFE AFE AFE AFE 2.458964 9.625E-06 1.247E-06 2.515E-06 6.808E-06 1.621 E-05 2.757E-05 2.781622 5.928E-06 7.020E-07 1.454E-06 4.087E-06 1.005E-05 1.739E-05 3.146617 3.568E-06 3.850E-07 8.195E-07 2.394E-06 6.083E-06 1.072E-05 3.559503 2.100E-06 2.059E-07 4.504E-07 1.369E-06 3.597E-06 6.451 E-06 4.026569 1.208E-06 1.073E-07 2.414E-07 7.631 E-07 2.077E-06 3.798E-06 4.554923 6.795E-07 5.454E-08 1.262E-07 4.152E-07 1.171E-06 2.185E-06 5.152606 3.741 E-07 2.701 E-08 6.429E-08 2.205E-07 6.457E-07 1.231 E-06 5.828714 2.018E-07 1.304E-08 3.196E-08 1.144E-07 3.480E-07 6.786E-07 6.593533 1.067E-07 6.137E-09 1.550E-08 5.793E-08 1.836E-07 3.672E-07 7.458715 5.549E-08 2.816E-09 7.331 E-09 2.867E-08 9.496E-08 1.952E-07 8.437425 2.840E-08 1.260E-09 3.387E-09 1.389E-08 4.824E-08 1.023E-07 9.544557 1.435E-08 5.498E-10 1.528E-09 6.592E-09 2.412E-08 5.289E-08 10.796952 7.188E-09 2.343E-10 6.741E-10 3.072E-09 1.190E-08 2.711 E-08 12.213694 3.578E-09 9.749E-11 2.912E-10 1.408E-09 5.813E-09 1.381 E-08 13.816336 1.777E-09 3.967E-11 1.233E-10 6.365E-10 2.818E-09 7.007E-09 15.629272 8.825E-10 1.580E-11 5.133E-11 2.847E-10 1.361 E-09 3.551 E-09 17.680094 4.394E-10 6.178E-12 2.105E-11 1.264E-10 6.562E-10 1.799E-09 20.000000 2.193E-10 2.373E-12 8.521 E-12 5.581 E-11 3.162E-10 9.113E-10 95 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.7-5: The 5% Damped SA at 2.5 Hz Control Point Hazard Curves for the CGS Site PSA Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile [g] AFE AFE AFE AFE AFE AFE 0.000100 9.485E-02 6.185E-02 7.100E-02 8.736E-02 1.125E-01 1.561 E-01 0.000113 9.480E-02 6.182E-02 7.097E-02 8.732E-02 1.125E-01 1.559E-01 0.000128 9.471 E-02 6.176E-02 7.091 E-02 8.724E-02 1.124E-01 1.555E-01 0.000145 9.457E-02 6.168E-02 7.082E-02 8.714E-02 1.123E-01 1.551 E-01 0.000164 9.438E-02 6.158E-02 7.070E-02 8.698E-02 1.121E-01 1.544E-01 0.000185 9.414E-02 6.144E-02 7.054E-02 8.679E-02 1.118E-01 1.535E-01 0.000210 9.385E-02 6.128E-02 7.035E-02 8.656E-02 1.115E-01 1.526E-01 0.000237 9.352E-02 6.11 OE-02 7.014E-02 8.631 E-02 1.112E-01 1.514E-01 0.000268 9.318E-02 6.090E-02 6.992E-02 8.603E-02 1.108E-01 1.502E-01 0.000303 9.282E-02 6.070E-02 6.968E-02 8.574E-02 1.105E-01 1.489E-01 0.000343 9.244E-02 6.048E-02 6.944E-02 8.544E-02 1.101 E-01 1.477E-01 0.000388 9.206E-02 6.027E-02 6.920E-02 8.513E-02 1.097E-01 1.464E-01 0.000439 9.166E-02 6.004E-02 6.894E-02 8.482E-02 1.093E-01 1.450E-01 0.000497 9.123E-02 5.980E-02 6.866E-02 8.448E-02 1.089E-01 1.436E-01 0.000562 9.076E-02 5.953E-02 6.836E-02 8.410E-02 1.083E-01 1.421 E-01 0.000636 9.019E-02 5.921 E-02 6.799E-02 8.365E-02 1.077E-01 1.405E-01 0.000719 8.949E-02 5.883E-02 6.755E-02 8.310E-02 1.069E-01 1.387E-01 0.000813 8.862E-02 5.833E-02 6.698E-02 8.242E-02 1.059E-01 1.365E-01 0.000920 8.752E-02 5.771 E-02 6.628E-02 8.156E-02 1.046E-01 1.340E-01 0.001041 8.618E-02 5.693E-02 6.540E-02 8.049E-02 1.030E-01 1.311 E-01 0.001177 8.456E-02 5.595E-02 6.429E-02 7.917E-02 1.011 E-01 1.278E-01 0.001332 8.262E-02 5.473E-02 6.294E-02 7.757E-02 9.880E-02 1.241 E-01 0.001507 8.035E-02 5.324E-02 6.131 E-02 7.565E-02 9.618E-02 1.200E-01 0.001704 7.774E-02 5.146E-02 5.936E-02 7.338E-02 9.320E-02 1.156E-01 0.001928 7.480E-02 4.940E-02 5.712E-02 7.079E-02 8.988E-02 1.109E-01 0.002181 7.160E-02 4.71 OE-02 5.463E-02 6.792E-02 8.630E-02 1.059E-01 0.002467 6.822E-02 4.464E-02 5.197E-02 6.485E-02 8.254E-02 1.008E-01 0.002791 6.475E-02 4.21 OE-02 4.922E-02 6.170E-02 7.869E-02 9.576E-02 0.003157 6.130E-02 3.956E-02 4.647E-02 5.852E-02 7.486E-02 9.074E-02 0.003571 5.793E-02 3.709E-02 4.379E-02 5.541 E-02 7.11 OE-02 8.587E-02 0.004040 5.468E-02 3.472E-02 4.120E-02 5.241 E-02 6.747E-02 8.119E-02 0.004570 5.156E-02 3.247E-02 3.872E-02 4.951 E-02 6.395E-02 7.671 E-02 0.005170 4.857E-02 3.032E-02 3.634E-02 4.672E-02 6.057E-02 7.241 E-02 0.005848 4.568E-02 2.827E-02 3.405E-02 4.401 E-02 5.725E-02 6.826E-02 0.006615 4.284E-02 2.629E-02 3.181 E-02 4.134E-02 5.396E-02 6.421 E-02 0.007483 4.002E-02 2.435E-02 2.959E-02 3.867E-02 5.065E-02 6.020E-02 0.008465 3.720E-02 2.244E-02 2.736E-02 3.597E-02 4.728E-02 5.621 E-02 0.009576 3.437E-02 2.055E-02 2.513E-02 3.324E-02 4.386E-02 5.221 E-02 0.010833 3.155E-02 1.869E-02 2.291 E-02 3.0SOE-02 4.040E-02 4.824E-02 0.012254 2.877E-02 1.688E-02 2.073E-02 2.780E-02 3.696E-02 4.432E-02 96 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure PSA Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile [g] AFE AFE AFE AFE AFE AFE 0.013862 2.608E-02 1.514E-02 1.863E-02 2.516E-02 3.360E-02 4.049E-02 0.015681 2.350E-02 1.349E-02 1.664E-02 2.264E-02 3.038E-02 3.681 E-02 0.017739 2.107E-02 1.195E-02 1.478E-02 2.026E-02 2.732E-02 3.330E-02 0.020066 1.881 E-02 1.052E-02 1.305E-02 1.803E-02 2.447E-02 2.999E-02 0.022699 1.672E-02 9.200E-03 1.147E-02 1.598E-02 2.182E-02 2.690E-02 0.025678 1.479E-02 8.006E-03 1.004E-02 1.410E-02 1.939E-02 2.403E-02 0.029047 1.304E-02 6.930E-03 8.746E-03 1.240E-02 1.717E-02 2.139E-02 0.032859 1.146E-02 5.968E-03 7.587E-03 1.085E-02 1.516E-02 1.898E-02 0.037170 1.003E-02 5.116E-03 6.554E-03 9.470E-03 1.335E-02 1.680E-02 0.042048 8.750E-03 4.366E-03 5.638E-03 8.238E-03 1.173E-02 1.483E-02 0.047565 7.612E-03 3.711 E-03 4.832E-03 7.144E-03 1.028E-02 1.306E-02 0.053806 6.604E-03 3.143E-03 4.127E-03 6.180E-03 8.987E-03 1.148E-02 0.060867 5.715E-03 2.655E-03 3.51 SE-03 5.332E-03 7.840E-03 1.007E-02 0.068853 4.935E-03 2.237E-03 2.986E-03 4.590E-03 6.826E-03 8.824E-03 0.077888 4.251 E-03 1.880E-03 2.530E-03 3.940E-03 5.927E-03 7.709E-03 0.088108 3.653E-03 1.577E-03 2.139E-03 3.373E-03 5.132E-03 6.717E-03 0.099670 3.130E-03 1.320E-03 1.803E-03 2.878E-03 4.428E-03 5.833E-03 0.112748 2.674E-03 1.103E-03 1.516E-03 2.446E-03 3.807E-03 5.046E-03 0.127542 2.276E-03 9.180E-04 1.270E-03 2.070E-03 3.259E-03 4.348E-03 0.144278 1.930E-03 7.615E-04 1.060E-03 1.744E-03 2.778E-03 3.730E-03 0.163210 1.629E-03 6.291 E-04 8.809E-04 1.463E-03 2.358E-03 3.187E-03 0.184625 1.370E-03 5.171 E-04 7.289E-04 1.222E-03 1.992E-03 2.709E-03 0.208851 1.146E-03 4.226E-04 6.002E-04 1.01 SE-03 1.676E-03 2.293E-03 0.236256 9.536E-04 3.431 E-04 4.914E-04 8.390E-04 1.403E-03 1.931 E-03 0.267257 7.893E-04 2.765E-04 3.998E-04 6.895E-04 1.168E-03 1.617E-03 0.302325 6.491 E-04 2.209E-04 3.229E-04 5.630E-04 9.670E-04 1.347E-03 0.341995 5.300E-04 1.749E-04 2.586E-04 4.564E-04 7.955E-04 1.114E-03 0.386871 4.293E-04 1.370E-04 2.052E-04 3.669E-04 6.492E-04 9.156E-04 0.437634 3.447E-04 1.060E-04 1.61 OE-04 2.922E-04 5.252E-04 7.463E-04 0.495059 2.739E-04 8.097E-05 1.247E-04 2.302E-04 4.207E-04 6.030E-04 0.560020 2.151 E-04 6.091 E-05 9.528E-05 1.790E-04 3.331 E-04 4.821 E-04 0.633503 1.668E-04 4.505E-05 7.161 E-05 1.373E-04 2.603E-04 3.810E-04 0.716629 1.274E-04 3.271 E-05 5.287E-05 1.036E-04 2.005E-04 2.971 E-04 0.810663 9.582E-05 2.327E-05 3.828E-05 7.689E-05 1.519E-04 2.283E-04 0.917036 7.080E-05 1.620E-05 2.714E-05 5.598E-05 1.131E-04 1.726E-04 1.037366 5.135E-05 1.102E-05 1.883E-05 3.995E-05 8.269E-05 1.283E-04 1.173485 3.653E-05 7.321 E-06 1.277E-05 2.791 E-05 5.927E-05 9.356E-05 1.327466 2.547E-05 4.744E-06 8.455E-06 1.909E-05 4.163E-05 6.694E-05 1.501652 1.741 E-05 2.998E-06 5.468E-06 1.277E-05 2.864E-05 4.697E-05 1.698694 1.166E-05 1.847E-06 3.453E-06 8.350E-06 1.931 E-05 3.232E-05 1.921589 7.655E-06 1.109E-06 2.130E-06 5.344E-06 1.275E-05 2.180E-05 2.173734 4.932E-06 6.506E-07 1.284E-06 3.349E-06 8.258E-06 1.444E-05 97 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure PSA Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile [g] AFE AFE AFE AFE AFE AFE 2.458964 3.121 E-06 3.725E-07 7.568E-07 2.056E-06 5.249E-06 9.386E-06 2.781622 1.942E-06 2.086E-07 4.367E-07 1.239E-06 3.277E-06 6.002E-06 3.146617 1.190E-06 1.143E-07 2.471 E-07 7.328E-07 2.013E-06 3.777E-06 3.559503 7.190E-07 6.147E-08 1.373E-07 4.264E-07 1.217E-06 2.342E-06 4.026569 4.290E-07 3.245E-08 7.496E-08 2.443E-07 7.264E-07 1.434E-06 4.554923 2.531 E-07 1.684E-08 4.029E-08 1.379E-07 4.279E-07 8.671 E-07 5.152606 1.479E-07 8.61 OE-09 2.134E-08 7.689E-08 2.492E-07 5.188E-07 5.828714 8.566E-08 4.338E-09 1.115E-08 4.236E-08 1.437E-07 3.075E-07 6.593533 4.925E-08 2.157E-09 5.759E-09 2.307E-08 8.203E-08 1.807E-07 7.458715 2.814E-08 1.059E-09 2.939E-09 1.244E-08 4.646E-08 1.054E-07 8.437425 1.598E-08 5.138E-10 1.484E-09 6.639E-09 2.611 E-08 6.105E-08 9.544557 9.033E-09 2.464E-10 7.408E-10 3.510E-09 1.456E-08 3.515E-08 10.796952 5.082E-09 1.168E-10 3.660E-10 1.839E-09 8.068E-09 2.012E-08 12.213694 2.846E-09 5.469E-11 1.789E-10 9.545E-10 4.439E-09 1.145E-08 13.816336 1.587E-09 2.530E-11 8.643E-11 4.911 E-10 2.426E-09 6.477E-09 15.629272 8.816E-10 1.155E-11 4.128E-11 2.505E-10 1.318E-09 3.643E-09 17.680094 4.873E-10 5.206E-12 1.949E-11 1.266E-10 7.109E-10 2.036E-09 20.000000 2.678E-10 2.314E-12 9.102E-12 6.349E-11 3.807E-10 1.130E-09 98 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.7-6: The 5% Damped SA at 1 Hz Control Point Hazard Curves for the CGS Site PSA Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile [g] AFE AFE AFE AFE AFE AFE 0.000010 9.458E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.000011 9.458E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.000013 9.458E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.000015 9.458E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.000017 9.458E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.000020 9.458E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.000023 9.457E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.000027 9.457E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.000031 9.456E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.000035 9.455E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.000040 9.454E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.000046 9.453E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.000053 9.452E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.000061 9.451 E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.000071 9.450E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.000081 9.449E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.000093 9.448E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.000107 9.446E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.549E-01 0.000123 9.442E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.548E-01 0.000142 9.433E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.544E-01 0.000163 9.420E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.538E-01 0.000187 9.404E-02 6.166E-02 7.079E-02 8.710E-02 1.122E-01 1.531 E-01 0.000215 9.382E-02 6.161 E-02 7.074E-02 8.704E-02 1.122E-01 1.523E-01 0.000248 9.335E-02 6.139E-02 7.048E-02 8.676E-02 1.118E-01 1.510E-01 0.000285 9.239E-02 6.081 E-02 6.981 E-02 8.603E-02 1.108E-01 1.487E-01 0.000327 9.098E-02 5.989E-02 6.876E-02 8.487E-02 1.093E-01 1.457E-01 0.000376 8.940E-02 5.885E-02 6.757E-02 8.356E-02 1.076E-01 1.423E-01 0.000433 8.781 E-02 5.781 E-02 6.636E-02 8.224E-02 1.059E-01 1.389E-01 0.000498 8.624E-02 5.678E-02 6.51 SE-02 8.093E-02 1.043E-01 1.356E-01 0.000572 8.471 E-02 5.576E-02 6.402E-02 7.965E-02 1.026E-01 1.324E-01 0.000658 8.320E-02 5.477E-02 6.288E-02 7.839E-02 1.01 OE-01 1.292E-01 0.000756 8.172E-02 5.380E-02 6.176E-02 7.715E-02 9.939E-02 1.262E-01 0.000870 8.027E-02 5.284E-02 6.066E-02 7.592E-02 9.781 E-02 1.232E-01 0.001000 7.882E-02 5.188E-02 5.956E-02 7.470E-02 9.624E-02 1.203E-01 0.001150 7.723E-02 5.081 E-02 5.836E-02 7.335E-02 9.450E-02 1.172E-01 0.001322 7.500E-02 4.926E-02 5.665E-02 7.139E-02 9.198E-02 1.133E-01 0.001520 7.177E-02 4.695E-02 5.417E-02 6.854E-02 8.830E-02 1.081 E-01 0.001748 6.811 E-02 4.431 E-02 5.135E-02 6.525E-02 8.407E-02 1.025E-01 0.002009 6.449E-02 4.172E-02 4.857E-02 6.201 E-02 7.988E-02 9.692E-02 0.002310 6.093E-02 3.91 BE-02 4.583E-02 5.878E-02 7.574E-02 9.149E-02 99 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure PSA Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile [g] AFE AFE AFE AFE AFE AFE 0.002656 5.706E-02 3.645E-02 4.281 E-02 5.518E-02 7.116E-02 8.570E-02 0.003054 5.266E-02 3.338E-02 3.933E-02 5.097E-02 6.588E-02 7.923E-02 0.003511 4.819E-02 3.028E-02 3.579E-02 4.665E-02 6.046E-02 7.269E-02 0.004037 4.402E-02 2.742E-02 3.251 E-02 4.262E-02 5.539E-02 6.660E-02 0.004642 4.020E-02 2.483E-02 2.952E-02 3.892E-02 5.074E-02 6.100E-02 0.005337 3.671 E-02 2.248E-02 2.680E-02 3.555E-02 4.648E-02 5.587E-02 0.006136 3.351 E-02 2.034E-02 2.433E-02 3.245E-02 4.255E-02 5.116E-02 0.007055 3.052E-02 1.836E-02 2.203E-02 2.955E-02 3.887E-02 4.676E-02 0.008111 2.755E-02 1.644E-02 1.981 E-02 2.666E-02 3.521 E-02 4.245E-02 0.009326 2.457E-02 1.453E-02 1.760E-02 2.373E-02 3.151E-02 3.817E-02 0.010723 2.173E-02 1.274E-02 1.552E-02 2.095E-02 2.799E-02 3.409E-02 0.012328 1.914E-02 1.111 E-02 1.361 E-02 1.841 E-02 2.474E-02 3.032E-02 0.014175 1.672E-02 9.574E-03 1.180E-02 1.606E-02 2.170E-02 2.674E-02 0.016298 1.451 E-02 8.159E-03 1.01 OE-02 1.391 E-02 1.888E-02 2.338E-02 0.018738 1.253E-02 6.911 E-03 8.598E-03 1.199E-02 1.636E-02 2.036E-02 0.021544 1.080E-02 5.838E-03 7.298E-03 1.033E-02 1.416E-02 1.771 E-02 0.024771 9.281 E-03 4.895E-03 6.158E-03 8.850E-03 1.223E-02 1.536E-02 0.028480 7.908E-03 4.043E-03 5.132E-03 7.512E-03 1.053E-02 1.328E-02 0.032745 6.686E-03 3.287E-03 4.222E-03 6.315E-03 9.026E-03 1.144E-02 0.037649 5.630E-03 2.650E-03 3.452E-03 5.284E-03 7.728E-03 9.842E-03 0.043288 4.732E-03 2.131 E-03 2.815E-03 4.410E-03 6.606E-03 8.461 E-03 0.049770 3.963E-03 1.706E-03 2.283E-03 3.662E-03 5.625E-03 7.267E-03 0.057224 3.294E-03 1.355E-03 1.832E-03 3.009E-03 4.754E-03 6.234E-03 0.065793 2.715E-03 1.065E-03 1.454E-03 2.445E-03 3.982E-03 5.329E-03 0.075646 2.219E-03 8.330E-04 1.146E-03 1.966E-03 3.301 E-03 4.510E-03 0.086975 1.794E-03 6.481 E-04 8.981 E-04 1.563E-03 2.699E-03 3.754E-03 0.100000 1.438E-03 5.023E-04 7.009E-04 1.231 E-03 2.184E-03 3.080E-03 0.114976 1.144E-03 3.871 E-04 5.444E-04 9.629E-04 1.750E-03 2.500E-03 0.132194 8.982E-04 2.944E-04 4.185E-04 7.458E-04 1.380E-03 1.995E-03 0.151991 6.933E-04 2.199E-04 3.175E-04 5.707E-04 1.067E-03 1.559E-03 0.174753 5.293E-04 1.623E-04 2.387E-04 4.331 E-04 8.147E-04 1.202E-03 0.200923 4.016E-04 1.189E-04 1.782E-04 3.268E-04 6.182E-04 9.205E-04 0.231013 3.019E-04 8.603E-05 1.315E-04 2.444E-04 4.654E-04 6.996E-04 0.265609 2.236E-04 6.084E-05 9.494E-05 1.800E-04 3.462E-04 5.252E-04 0.305386 1.633E-04 4.200E-05 6.706E-05 1.305E-04 2.547E-04 3.899E-04 0.351119 1.185E-04 2.864E-05 4.686E-05 9.415E-05 1.867E-04 2.884E-04 0.403702 8.606E-05 1.950E-05 3.268E-05 6.782E-05 1.370E-04 2.134E-04 0.464159 6.239E-05 1.325E-05 2.274E-05 4.870E-05 1.003E-04 1.577E-04 0.533670 4.490E-05 8.926E-06 1.567E-05 3.462E-05 7.286E-05 1.157E-04 0.613591 3.181E-05 5.896E-06 1.060E-05 2.415E-05 5.207E-05 8.363E-05 0.705481 2.202E-05 3.785E-06 6.973E-06 1.640E-05 3.635E-05 5.915E-05 0.811131 1.483E-05 2.345E-06 4.435E-06 1.079E-05 2.467E-05 4.078E-05 1 oo of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure PSA Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile [g] AFE AFE AFE AFE AFE AFE 0.932604 9.702E-06 1.398E-06 2.720E-06 6.873E-06 1.624E-05 2.735E-05 1.072268 6.171E-06 8.023E-07 1.611 E-06 4.241 E-06 1.040E-05 1.788E-05 1.232847 3.831 E-06 4.452E-07 9.253E-07 2.547E-06 6.486E-06 1.142E-05 1.417475 2.328E-06 2.404E-07 5.183E-07 1.494E-06 3.956E-06 7.143E-06 1.629751 1.386E-06 1.271 E-07 2.843E-07 8.582E-07 2.361 E-06 4.370E-06 1.873819 8.065E-07 6.589E-08 1.526E-07 4.814E-07 1.374E-06 2.607E-06 2.154435 4.562E-07 3.338E-08 7.980E-08 2.624E-07 7.766E-07 1.510E-06 2.477078 2.500E-07 1.641 E-08 4.040E-08 1.383E-07 4.244E-07 8.466E-07 2.848037 1.324E-07 7.773E-09 1.967E-08 7.003E-08 2.237E-07 4.588E-07 3.274549 6.794E-08 3.525E-09 9.169E-09 3.407E-08 1.138E-07 2.410E-07 3.764938 3.393E-08 1.526E-09 4.088E-09 1.594E-08 5.619E-08 1.234E-07 4.328762 1.662E-08 6.309E-10 1.746E-09 7.207E-09 2.708E-08 6.213E-08 4.977026 8.067E-09 2.498E-10 7.182E-10 3.172E-09 1.286E-08 3.100E-08 5.722369 3.914E-09 9.512E-11 2.861E-10 1.370E-09 6.068E-09 1.545E-08 6.579331 1.912E-09 3.507E-11 1.113E-10 5.863E-10 2.866E-09 7.734E-09 7.564636 9.431 E-10 1.260E-11 4.256E-11 2.502E-10 1.360E-09 3.893E-09 8.697490 4.693E-10 4.441E-12 1.613E-11 1.071E-10 6.492E-10 1.969E-09 10.000005 2.350E-10 1.543E-12 6.090E-12 4.606E-11 3.112E-10 9.969E-10 101 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 2.3.7-7: The 5% Damped SA at 0.5 Hz Control Point Hazard Curves for the CGS Site PSA Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile [g] AFE AFE AFE AFE AFE AFE 0.000010 9.476E-02 6.178E-02 7.093E-02 8.727E-02 1.124E-01 1.555E-01 0.000011 9.476E-02 6.178E-02 7.093E-02 8.727E-02 1.124E-01 1.555E-01 0.000013 9.476E-02 6.178E-02 7.093E-02 8.727E-02 1.124E-01 1.555E-01 0.000015 9.476E-02 6.178E-02 7.093E-02 8.727E-02 1.124E-01 1.555E-01 0.000017 9.472E-02 6.176E-02 7.090E-02 8.724E-02 1.124E-01 1.554E-01 0.000020 9.460E-02 6.169E-02 7.082E-02 8.714E-02 1.122E-01 1.550E-01 0.000023 9.443E-02 6.158E-02 7.069E-02 8.698E-02 1.120E-01 1.545E-01 0.000027 9.423E-02 6.146E-02 7.056E-02 8.681 E-02 1.118E-01 1.539E-01 0.000031 9.403E-02 6.133E-02 7.042E-02 8.664E-02 1.116E-01 1.533E-01 0.000035 9.383E-02 6.121 E-02 7.028E-02 8.646E-02 1.114E-01 1.526E-01 0.000040 9.363E-02 6.109E-02 7.014E-02 8.629E-02 1.111E-01 1.520E-01 0.000046 9.344E-02 6.097E-02 7.000E-02 8.612E-02 1.109E-01 1.514E-01 0.000053 9.324E-02 6.085E-02 6.986E-02 8.595E-02 1.107E-01 1.508E-01 0.000061 9.304E-02 6.073E-02 6.972E-02 8.577E-02 1.105E-01 1.502E-01 0.000071 9.284E-02 6.061 E-02 6.958E-02 8.560E-02 1.102E-01 1.496E-01 0.000081 9.263E-02 6.047E-02 6.943E-02 8.542E-02 1.100E-01 1.490E-01 0.000093 9.231 E-02 6.028E-02 6.920E-02 8.518E-02 1.096E-01 1.481 E-01 0.000107 9.169E-02 5.989E-02 6.876E-02 8.479E-02 1.089E-01 1.465E-01 0.000123 9.067E-02 5.926E-02 6.804E-02 8.418E-02 1.078E-01 1.439E-01 0.000142 8.942E-02 5.849E-02 6.71 SE-02 8.343E-02 1.064E-01 1.408E-01 0.000163 8.807E-02 5.765E-02 6.620E-02 8.262E-02 1.049E-01 1.375E-01 0.000187 8.646E-02 5.660E-02 6.502E-02 8.150E-02 1.031 E-01 1.339E-01 0.000215 8.408E-02 5.495E-02 6.322E-02 7.953E-02 1.00SE-01 1.296E-01 0.000248 8.077E-02 5.259E-02 6.067E-02 7.653E-02 9.682E-02 1.242E-01 0.000285 7.701 E-02 4.986E-02 5.775E-02 7.300E-02 9.268E-02 1.184E-01 0.000327 7.326E-02 4.717E-02 5.484E-02 6.947E-02 8.854E-02 1.127E-01 0.000376 6.969E-02 4.461 E-02 5.207E-02 6.609E-02 8.457E-02 1.072E-01 0.000433 6.628E-02 4.21 SE-02 4.943E-02 6.287E-02 8.078E-02 1.020E-01 0.000498 6.304E-02 3.989E-02 4.693E-02 5.981 E-02 7.715E-02 9.699E-02 0.000572 5.996E-02 3.772E-02 4.456E-02 5.690E-02 7.369E-02 9.227E-02 0.000658 5.703E-02 3.567E-02 4.231 E-02 5.413E-02 7.039E-02 8.778E-02 0.000756 5.424E-02 3.373E-02 4.016E-02 5.149E-02 6.723E-02 8.350E-02 0.000870 5.155E-02 3.187E-02 3.81 OE-02 4.895E-02 6.415E-02 7.937E-02 0.001000 4.875E-02 2.997E-02 3.595E-02 4.629E-02 6.088E-02 7.508E-02 0.001150 4.554E-02 2.786E-02 3.348E-02 4.326E-02 5.700E-02 7.017E-02 0.001322 4.207E-02 2.563E-02 3.081 E-02 3.998E-02 5.271 E-02 6.485E-02 0.001520 3.870E-02 2.348E-02 2.823E-02 3.681 E-02 4.852E-02 5.969E-02 0.001748 3.556E-02 2.149E-02 2.584E-02 3.384E-02 4.462E-02 5.489E-02 0.002009 3.257E-02 1.961 E-02 2.359E-02 3.102E-02 4.091 E-02 5.031 E-02 0.002310 2.960E-02 1.777E-02 2.137E-02 2.820E-02 3.726E-02 4.575E-02 102 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure PSA Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile [g] AFE AFE AFE AFE AFE AFE 0.002656 2.670E-02 1.599E-02 1.923E-02 2.546E-02 3.372E-02 4.129E-02 0.003054 2.402E-02 1.435E-02 1.726E-02 2.292E-02 3.045E-02 3.718E-02 0.003511 2.160E-02 1.288E-02 1.549E-02 2.063E-02 2.748E-02 3.346E-02 0.004037 1.943E-02 1.156E-02 1.390E-02 1.857E-02 2.481 E-02 3.012E-02 0.004642 1.747E-02 1.037E-02 1.247E-02 1.671 E-02 2.239E-02 2.711 E-02 0.005337 1.570E-02 9.294E-03 1.118E-02 1.502E-02 2.019E-02 2.438E-02 0.006136 1.404E-02 8.268E-03 9.971 E-03 1.345E-02 1.811 E-02 2.185E-02 0.007055 1.244E-02 7.244E-03 8.797E-03 1.192E-02 1.607E-02 1.944E-02 0.008111 1.092E-02 6.257E-03 7.683E-03 1.047E-02 1.413E-02 1.718E-02 0.009326 9.545E-03 5.358E-03 6.661 E-03 9.155E-03 1.238E-02 1.514E-02 0.010723 8.295E-03 4.528E-03 5.701 E-03 7.940E-03 1.083E-02 1.332E-02 0.012328 7.154E-03 3.755E-03 4.791 E-03 6.812E-03 9.471 E-03 1.171 E-02 0.014175 6.136E-03 3.073E-03 3.975E-03 5.800E-03 8.274E-03 1.028E-02 0.016298 5.255E-03 2.503E-03 3.284E-03 4.926E-03 7.226E-03 9.020E-03 0.018738 4.491 E-03 2.033E-03 2.704E-03 4.171 E-03 6.301 E-03 7.918E-03 0.021544 3.813E-03 1.636E-03 2.202E-03 3.495E-03 5.460E-03 6.947E-03 0.024771 3.205E-03 1.296E-03 1.763E-03 2.885E-03 4.689E-03 6.089E-03 0.028480 2.678E-03 1.01 SE-03 1.397E-03 2.358E-03 4.005E-03 5.335E-03 0.032745 2.233E-03 7.966E-04 1.104E-03 1.922E-03 3.415E-03 4.673E-03 0.037649 1.858E-03 6.229E-04 8.708E-04 1.562E-03 2.900E-03 4.078E-03 0.043288 1.534E-03 4.848E-04 6.835E-04 1.256E-03 2.432E-03 3.516E-03 0.049770 1.250E-03 3.741 E-04 5.31 SE-04 9.932E-04 2.001 E-03 2.977E-03 0.057224 1.006E-03 2.862E-04 4.102E-04 7.749E-04 1.618E-03 2.480E-03 0.065793 8.000E-04 2.166E-04 3.136E-04 5.991 E-04 1.289E-03 2.034E-03 0.075646 6.277E-04 1.617E-04 2.374E-04 4.597E-04 1.011 E-03 1.643E-03 0.086975 4.873E-04 1.195E-04 1.782E-04 3.507E-04 7.830E-04 1.309E-03 0.100000 3.753E-04 8.750E-05 1.329E-04 2.662E-04 6.014E-04 1.034E-03 0.114976 2.853E-04 6.312E-05 9.778E-05 1.999E-04 4.559E-04 8.010E-04 0.132194 2.128E-04 4.445E-05 7.050E-05 1.476E-04 3.389E-04 6.050E-04 0.151991 1.562E-04 3.068E-05 4.998E-05 1.075E-04 2.481 E-04 4.477E-04 0.174753 1.140E-04 2.098E-05 3.517E-05 7.786E-05 1.805E-04 3.286E-04 0.200923 8.287E-05 1.428E-05 2.464E-05 5.618E-05 1.31 OE-04 2.403E-04 0.231013 5.964E-05 9.580E-06 1.705E-05 4.007E-05 9.424E-05 1.742E-04 0.265609 4.205E-05 6.238E-06 1.147E-05 2.791 E-05 6.672E-05 1.241 E-04 0.305386 2.904E-05 3.924E-06 7.499E-06 1.897E-05 4.649E-05 8.695E-05 0.351119 1.991 E-05 2.426E-06 4.835E-06 1.276E-05 3.226E-05 6.060E-05 0.403702 1.373E-05 1.509E-06 3.135E-06 8.635E-06 2.252E-05 4.249E-05 0.464159 9.500E-06 9.477E-07 2.046E-06 5.864E-06 1.576E-05 2.988E-05 0.533670 6.508E-06 5.924E-07 1.325E-06 3.942E-06 1.090E-05 2.079E-05 0.613591 4.354E-06 3.616E-07 8.357E-07 2.583E-06 7.347E-06 1.414E-05 0.705481 2.818E-06 2.126E-07 5.078E-07 1.633E-06 4.785E-06 9.314E-06 0.811131 1.762E-06 1.197E-07 2.956E-07 9.927E-07 3.00SE-06 5.937E-06 103 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure PSA Mean 5m Fractile 16m Fractile 50m Fractile 84m Fractile 95m Fractile [g] AFE AFE AFE AFE AFE AFE 0.932604 1.068E-06 6.462E-08 1.653E-07 5.821 E-07 1.827E-06 3.675E-06 1.072268 6.321 E-07 3.367E-08 8.946E-08 3.314E-07 1.082E-06 2.223E-06 1.232847 3.675E-07 1.707E-08 4.717E-08 1.844E-07 6.286E-07 1.322E-06 1.417475 2.110E-07 8.481 E-09 2.440E-08 1.008E-07 3.600E-07 7.760E-07 1.629751 1.199E-07 4.146E-09 1.243E-08 5.430E-08 2.036E-07 4.507E-07 1.873819 6.752E-08 1.996E-09 6.241 E-09 2.884E-08 1.138E-07 2.590E-07 2.154435 3.763E-08 9.463E-10 3.085E-09 1.509E-08 6.278E-08 1.472E-07 2.477078 2.072E-08 4.407E-10 1.498E-09 7.771 E-09 3.412E-08 8.254E-08 2.848037 1.125E-08 2.007E-10 7.122E-10 3.925E-09 1.824E-08 4.562E-08 3.274549 6.021 E-09 8.91 OE-11 3.305E-10 1.942E-09 9.570E-09 2.481 E-08 3.764938 3.173E-09 3.844E-11 1.494E-10 9.397E-10 4.926E-09 1.326E-08 4.328762 1.646E-09 1.608E-11 6.570E-11 4.443E-10 2.486E-09 6.969E-09 4.977026 8.407E-10 6.521 E-12 2.809E-11 2.053E-10 1.230E-09 3.597E-09 5.722369 4.226E-10 2.561 E-12 1.168E-11 9.265E-11 5.961E-10 1.823E-09 6.579331 2.092E-10 9.745E-13 4.721 E-12 4.084E-11 2.833E-10 9.073E-10 7.564636 1.020E-10 3.592E-13 1.855E-12 1.759E-11 1.319E-10 4.433E-10 8.697490 4.903E-11 1.282E-13 7.088E-13 7.391 E-12 6.027E-11 2.128E-10 10.000005 2.323E-11 4.438E-14 2.634E-13 3.036E-12 2.701E-11 1.003E-10 104 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 10:: 02 .... 10:: LO:: 01 10:: 08 0.01 CGS: Fractile Hazard Curves, 100 Hz ** . .. **** ... * .. ****** ... ' ' ' \ ' \ 0.1 ' \ \ \ \ \ \ . \ . \ \ \ \ \ \ \ \ \ \ \ \ \ PGA(g) ****** L' Figure 2.3.7-1: Control Point Mean and 5th, 16th, soth, s4th, and 95th Percentile Fractile Hazard Curves for Spectral Frequency 5% Damped SA at 100 Hz (PGA) at the CGS Site 105 of 136 10 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure CJ u c "" "CS CJ CJ u )( ..... 0 > u c CJ :J ... ;::; :J c c <t c ... CJ CGS: Fractile Hazard Curves, 25 Hz LO:: 02 ..... .. ..... '** .. ........... . ,** ... --\.1C'.:t* .. **. '**. ' ' . -* :it" "**:,ct c . !Gt" "":*Ct LO:: ' ' . c ' . . --"":*Ct c ' ' . -* 8*'.t" "":tCt c ' . ' ' . ' . ...... t c LO:: Ot. ' . ' . . \ ' ' . \ \ ' *. !Ci:: Cb \ \ \ *. \ \ \ . ' !.(;:_ (it> \ ' ' ' \ ' LO:: 01 ' \ ' \ \ \ \ LO:: 08 . 0.01 0.1 SA (g) Figure 2.3.7-2: Control Point Mean and s'h, 161h, so'h, 841h, and 95*h Percentile Fractile Hazard Curves for the Spectral Frequency 5% Damped SA at 25 Hz at the CGS Site 106 of 136 10 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure LO:: 02 LO:: LO:: 01 LO:: 08 0.01 CGS: Fractile Hazard Curves, 10 Hz 0.1 ' ** . . ,** ... . ..:** ... ' . ,** .. ' . * .. '* .. ' . * .. ' '* .. ' . ,** ... \ \ \ SA (g) . . '** .. . . \ ' .... . . . \ ** .. \ . * .. \ \ *. \ \ \ --\.1C'O:t ... ' ' Figure 2.3.7-3: Control Point Mean and 51h, 161h, 501h, 841h, and 95th Percentile Fractile Hazard Curves for the Spectral Frequency 5% Damped SA at 10 Hz at the CGS Site 107 of 136 10 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 10:: 02 lO:: 10:: 01 10:: 08 0.1 CGS: Fractile Hazard Curves, 5 Hz . ._::* .... .. , .... . :.: .... . . ........ . . ... 'ii: * * ** ' " ' ... " . .. .... ' "\ * .. . .. \.. " . * .. "' ' \ * .. ' . *. \ \ '\. \ , ... \ .... \ \ \ \ \ . ,** .. . \ . \ \. ,\. \ .... '*. \ ' . *. ' \ ... ' .... \ ' ' ... .. ' '\ \ . *. \ \ \ .... SA (g) -\ .. ... Figure 2.3.7-4: Control Point Mean and 51h, 161h, 501h, 841h, and 95th Percentile Fractile Hazard Curves for the Spectral Frequency 5% Damped SA at 5 Hz at the CGS Site 108 of 136 100 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure CJ u c ... "C CJ CJ .., x ..... 0 > .., c CJ :J l: ... ;:;; :J c c <r c ... CJ :2; CGS: Fractile Hazard Curves, 2.5 Hz 10:: 02 --\ .. ... 10:: ' --.. e 10:: 01. !Ci:: (i) l.O:: Cit> LO:: 01 10:: 08 SA(g) Figure 2.3.7-5: Control Point Mean and s'h, 161h, so'h, 841h, and 95*h Percentile Fractile Hazard Curves for the Spectral Frequency 5% Damped SA at 2.5 Hz at the CGS Site 109 of 136 100 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 10:: 02 10:: LO:: 01 10:: 08 CGS: Fractile Hazard Curves, 1 Hz '* ... .... . * .. " ' **. " . ,** .. . ' . **. ' ' '** .. 0.1 . ' . ,** .. '-' . "*. ' ' ' *. . . ' . .. '\. ' . * .. ' '* .. ' . * .. '\. ' '* .. ' . , .... ' ' . * .. ' ' '** .. ' .... \ .\ ' \ * .. \ . *. \ ' ' ... \ . ,** ... ' .... \ ' '\ ' *, \ \ \ .... ' ' ... ' . \. * .. l SA(g) --\1c;,*' --.. e *****
• L' Figure 2.3.7-6: Control Point Mean and 5th, 16th, soth, s4th, and 95th Percentile Fractile Hazard Curves for the Spectral Frequency 5% Damped SA at 1 Hz at the CGS Site 110 of 136 100 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure ., .... c 1.0E-01. 1 1.0E-04 :: .... x w -0 c 1.0E-05 g-ol: ii :I c c <( 1 OE-06 ., ::E 1.0E-07 1.0E-08 0.01 CGS: Fractile Hazard Curves, 0.5 Hz . ..:..*** . .. . . ... --Me;m ..... . .. 'ii; ..... ,** .... . '** ... -*5th Fi.utile . ,*** .. *. le.th f1"Htile ' * ... --F1<11tile 01 . '* .... *. ' ** .. . .. ' ' * .... ' ' ... ' . * .. ' ' ' ** .. ' '* ... ' . * .. ' ' ... -*
• 84th flil( tile ****** 95d1 F1<1ctile ' . ,** ... \ ' . *. \ SA (g) ' * .. ' .... \ ' '. * .... \ 1 ' ... \ .... ' \ ** .. \ . \ * ... ' . * .. \ ' ... \ .... \ *. \ .... \ *._ Figure 2.3.7-7: Control Point Mean and 51h, 161h, 501h, 841h, and 951h Percentile Fractile Hazard Curves for the Spectral Frequency 5% Damped SA at 0.5 Hz at the CGS Site 111 of 136 10 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 2.4 Control Point Response Spectra The control point hazard curves described above have been used to develop uniform hazard response spectra (UHRS) and the ground motion response spectrum (GMRS). The UHAS were obtained through linear interpolation in log-log space to estimate the spectral acceleration at each of the 20 oscillator frequencies for the 10-4 and 10-5 per year hazard levels. The control point UHRS for 10*4 and 10"5 hazard levels, along with a design factor (OF) are used to compute the GMRS at the control point using the criteria in Regulatory Guide 1.208 (USNRC, 2007). Table 2.4-1 shows the UHRS and GMRS spectral accelerations and these spectra which are also plotted in Figure 2.4-1 . Table 2.4-1: 5% Damped UHAS for 10*4 and 10"5 Hazard Levels and GMRS at Control Point for the CGS Site Frequency Mean UHRS [g] Mean UHRS [g] GMRS (Hz) (AFE=104} (AFE=10"5) (g] 100.000 0.2484 0.4288 0.2484 50.000 0.2951 0.5057 0.2951 33.333 0.3471 0.6242 0.3471 25.000 0.3916 0.7238 0.3916 20.000 0.3595 0.6537 0.3595 13.333 0.4341 0.8088 0.4341 10.000 0.4978 0.9638 0.5067 6.667 0.7427 1.4240 0.7501 5.000 1.2160 2.4340 1.2711 3.333 1.3236 2.8030 1.4474 2.500 0.7958 1.7767 0.9078 2.000 0.7360 1.7620 0.8878 1.333 0.5313 1.3565 0.6748 1.000 0.3781 0.9234 0.4634 0.667 0.3089 0.7104 0.3609 0.500 0.1851 0.4552 0.2281 0.333 0.0837 0.1917 0.0974 0.200 0.0435 0.0912 0.0472 0.133 0.0262 0.0540 0.0280 0.100 0.0196 0.0397 0.0207 112 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 3 2.5 2 tiO -c: c '.w IV 1.5 u <( -a. II) 1 0.5 0 0.1 GMRS: CGS, Approach 3, Mean (No Min) ,, ' \ ' \ ' \i I l ' ' ' ' I l , ' ' ' ' I l I l I I \ I \ I \ I \ 3 (10-5) 3 GMRS 3 (10-4) I ', , c:: .. ,-' I I n , , , 1 10 Frequency {Hz) Figure 2.4-1: Control Point UHAS for 10*4 and 10*5 Hazard Levels and GMRS at Control Point for the CGS Site 113 of 136 100 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 3.0 Plant Design Basis and Beyond Design Basis Evaluation Ground Motion The seismic design basis for CGS is identified in Section 3.7 of the Final Safely Analysis Report (EN, 2013b) and other pertinent documents (EN, 1993, 2003. & 2011 ). 3. 1 SSE Description of Spectral Shape The SSE was developed in accordance with Appendix A of 10 CFR Part 100 through an evaluation of the maximum earthquake potential for the region surrounding the site. The original investigation of historical seismic activity in the region is described in the FSAR (EN, 1998 and 2013b). The design response spectrum is based on Newmark-Hall spectrum shape, and hence similar but not identical to Regulatory Guide (RG) 1.60 (NRC. 1973) generic response spectra. However, after the RG 1.60 response spectrum became available, a confirmatory seismic analysis was performed using the RG 1.60 response spectrum scaled to 0.25 g peak ground acceleration to verify that the the structural responses from use of the two spectra were within 10% of each other at almost all locations (see FSAR Section 3.7.1.1 ). Additionally, Section 3.7.2.5 of the FSAR notes that, for primary metal containment, the RPV, the RPV pedestal, and the sacrificial shield wall, the RG spectrum was used for determination of seismic demands and development of in-structure response spectra. The original 5% damped horizontal response spectrum and the RG 1.60 response spectrum are shown in Figure 3.1-1 and tabulated in Table 3.1-1. For analysis of the structures, a set of synthetic time histories was generated and used in the seismic analysis. The response spectra from the time histories enveloped the Operating Basis Earthquake (OBE) response spectra (half of SSE) by a large margin. A typical comparison of the time history response spectrum with SSE spectrum is shown in Figure 3.1-2 (Figure 3. 7-8 of the updated FSAR). The response spectrum method of analysis was used for seismic analysis of the Seismic Category I structures. However, time history analyses of the structures were also performed to develop in-structure response spectra for Seismic Category I systems and components in these structures. 114 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Table 3.1-1: The 5% Damped Horizontal SSE for CGS and the RG 1.60 with PGA of 0.25 g SSE RG 1.60 Frequency [Hz] SA (g] Frequency [Hz] SA [g] 0.40 0.12 0.10 0.019 2.05 0.60 0.25 0.118 6.10 0.60 2.50 0.783 18.9 0.25 9.00 0.653 100.0 0.25 33.00 0.250 115 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 0.9 0.8 0.7 s 0.6 Cl) u -0.5 u [ en_ 0.4 "C E Ill c 0.3 . . . . . .. . .. . * . **. : **. . . . . .. ... .. /,---\ *** . . . . ' . . . . . . . /1 \ ./°I \ ... .// \ . * .. . . . ...... 1 \ ... *. * * *** RG 1.60 -SSE It) ...... / \ *. . 02 0.1 .... 0 0.1 .. .. .** .* ... ** / .... ** / ... ** / ... **. 10 Frequency (Hz) Figure 3.1-1: The 5% Damped Horizontal SSE for CGS and RG 1.60 with PGA 0.25 g (Source: FSAR Figure 3.7-3; EN, 2013b) 100 Note: RG 1.60 spectrum was used for design of SSCs associated with the primary containment structure. 116 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Ope*at 19 Bass Her zontal Corrpc'le'lt Darrping=0.050 0.56 ....---------------------------------. 0.48 040 0.32 5 !ii ] 0.24 " <I: 0.16 0.08 Synt1et c H story Respc'lse Spect' Jm Desgn Res:Xl'lse SpectrJm 0.00 .....__ ____________________________ ___. o.oo 0.20 o.40 o so o so 100 uo 1.40 uo 1ao 2 oo 220 2 40 NatJral Pe *iod
• Seccnds Figure 3.1-2: The 5% Damped SA of the Time Series Used for Analysis (Source: FSAR Figure 3.7-8; EN, 2013b) 117 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 3.2 Control Point Elevation The CGS site is a soil site with a thickness of about 525 ft. All Seismic Category I structures are supported by a soil layer with embedment depth ranging from 4 ft to 21.5 ft {FSAR Table 3.7-2, EN, 2013b). For seismic analyses of the structures, the SSE control point elevation is defined at the basemat level of the structures attached to soil springs for SSI analysis. Given the previous analysis and the recommendations of the SPID document (EPRI, 2013a) for soil sites, the control point elevation is considered to be at the surface of the finished grade (El. 441 ft). This location has therefore been used to compute the GMRS. 3.3 IPEEE Description and Capacity Response Spectrum Section 5.0 summarizes the Individual Plant Examination of External Events (IPEEE) and IPEEE seismic PAA assessment and provides the plant-level high-confidence low-probability of failure (HCLPF) capacity spectrum for the CGS. 118 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 4.0 Screening Evaluation In accordance with SPID (EPRI, 2013a) Section 3, a screening evaluation was performed as described below. 4. 1 Risk Evaluation Screening (1 to 10 Hz) In the 1 to 10 Hz part of the response spectrum, the GMRS exceeds the SSE. Therefore, CGS screens in for a risk evaluation. 4.2 High Frequency Screening(> 10 Hz) For the range above 1 O Hz, the GMRS exceeds the SSE. The high frequency exceedances will be addressed in the risk evaluation discussed in 4.1 above. 4.3 Spent Fuel Pool Evaluation Screening (1 to 10 Hz) In the 1 to 10 Hz part of the response spectrum, the GMRS exceeds the SSE. Therefore, CGS screens in tor a spent fuel pool evaluation. 119 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 5.0 Interim Actions Based on the screening evaluation, the expedited seismic evaluation described in EPRI (2013b) is planned. Consistent with NRC letter dated February 20, 2014, (NRC, 2014a) the seismic hazard reevaluations presented herein are distinct from the current design and licensing bases of CGS. Therefore, the results do not call into question the operability or functionality of SSCs and are not reportable pursuant to10 CFR 50.72, "Immediate notification requirements for operating nuclear power reactors," and 10 CFR 50.73, "Licensee event report system" .. The NRC letter also requests that licensees provide an interim evaluation or actions to demonstrate that the plant can cope with the reevaluated hazard while the expedited approach and risk evaluations are conducted. In response to that request, NEI letter dated March 12, 2014 (NEI, 2014), provides seismic core damage risk estimates using the updated seismic hazards tor the operating nuclear plants in the Central and Eastern United States. These risk estimates continue to support the following conclusions of the N RC Gl-199 Safety/Risk Assessment (NRC, 201 Ob): Overall seismic core damage risk estimates are consistent with the Commission's Safety Goal Policy Statement because they are within the subsidiary objective of 10*4/year for core damage frequency. The Gl-199 Safety/Risk Assessment, based in part on information from the U.S. Nuclear Regulatory Commission's (NRC's) Individual Plant Examination of External Events {IPEEE) program. indicates that no concern exists regarding adequate protection and that the current seismic design of operating reactors provides a safety margin to withstand potential earthquakes exceeding the original design basis. CGS is a western plant, and hence it was not included in the March 12, 2014 risk estimates (NEI, 2014). In any case, using the Gl-199 Appendix A methodology and based on CGS's most recently reported SCDF value of 4.9x 10-6/year. the CGS's plant-level HCLPF capacity is estimated to be 0.395 g (PGA value). It is noted that the 4.9x 10-6/year SCDF value is the third SCDF update since the original IPEEE Seismic PAA; one SCDF update because of Seismic PRA update in 2004, and two more SCDF updates due to revision of plant models for internal events (EN, 2011 ). Integration of the plant-level fragility (corresponding to 0.395 g PGA HCLPF capacity) with the latest PGA seismic hazard results in revised SCDF estimate as 8.5x 10-7 per year, which is about two orders of magnitude smaller than the 10*4 per year maximum seismic risk threshold considered in Gl-199 (see further discussion below under the heading '"/PEEE and Post-IPEEE Seismic PRA Assessments'}. 120 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Additional information is provided below about the recent 2.3 Seismic Walkdowns. and historical Seismic PRA assessments to demonstrate that: (a) CGS' plant-level HCLPF capacity spectrum well exceeds its seismic design basis spectrum; and (b) CGS plant continues to have a very low seismic risk when the latest PSHA results are factored in. 2.3 Seismic Walkdowns and IPEEE Information The 2.3 Seismic Walkdowns were performed at CGS during 2013 for a broad range of safety related equipment and the walkdown summary is documented in CGS' final walkdown report (EN, 2013a). The NRC, in letter dated March 11, 2014 (NRC, 2014b), determined that sufficient information was provided to be responsive to Enclosure 3 of the 50.54(f) letter. This concluded the NRC's efforts associated with 2.3 Seismic for CGS. The letter reported that CGS had no significant degraded, non-conforming or unanalyzed conditions that warranted any modification[s] to the plant. CGS had no as-found conditions that would prevent SSCs from performing their required safety functions. CGS' 2.3 Seismic Walkdown report also noted that all the IPEEE identified issues have been resolved. Based on the NRC staff's review of the report, the staff concluded that the licensee's identification of plant-specific vulnerabilities (including anomalies, outliers and other findings) identified by the IPEEE program, as well as actions taken to eliminate or reduce them, meets the intent of Section 7 (IPEEE vulnerabilities) of the walkdown guidance. Expedited Seismic Evaluation Process The Expedited Seismic Evaluation Process (ESEP) walkdowns and seismic margin evaluations for CGS will be initiated later in 2015. The seismic demand used in the ESEP will be 2 x CGS SSE in-structure response spectra (ISRS). It is noted that the plant-level HCLPF capacity spectrum well exceeds the plant SSE spectrum (by a factor of approximately 1.5 to 1.7), and the new PGA hazard curve is enveloped by the PGA hazard curve used in the past Seismic PRA assessments. The combination of these two factors suggests that very few expedited seismic equipment list (ESEL) items, if any, will require upgrade/modifications to achieve seismic margin of at least 2 x SSE. IPEEE and Post-IPEEE Seismic PRA Assessments As part of the response to IPEEE-Seismic. CGS performed a full scope seismic PAA assessment in the mid 1990's (EN, 1995). This assessment was performed using the 10,000-year uniform hazard spectrum shape, scaled up to 0.50 g PGA, for use as the RLE spectrum. This ground motion is two times the CGS SSE. In its IPEEE-Seismic report, CGS reported an SCDF value of 2.1x10-5 per year using the PGA hazard curve that was developed in 1994. The IPEEE report was reviewed by the NRG and the identified vulnerabilities were resolved. 121 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure During CGS' license amendment application for license renewal, three subsequent updates were performed on the original IPEEE Seismic PRA. In 2004, several fragility calculations were updated, resulting in a revised SCDF value of 6.67x10"6 per year {the PGA hazard curve from 1994 was the same, albeit extended to cover low annual probabilities of exceedance) (NRC, 201 Oa). In 2007 and 2010, the plant systems models for Seismic PRA and internal events were successively updated, which led to further reduction of SCDF to 5.24x 10-6/year and 4.9x 10-6 per year, respectively {NRC, 2010a; EN, 2011). Section 5.3.2 of NUREG-1437, Supplement No. 47 (NRC. 2012b), documents NRC's review and acceptance of this decreasing trend in SCDF values. It was also noted in this section that the plant-specific PGA hazard curve based on USGS 2008 work was more benign than the PGA hazard curve that was used for CGS' Seismic PRA studies, thus indicating that the SCDF would be even lower than 4.9x 1 o*6 per year if the USGS hazard results were to be used. The Gl-199 methodology was used to estimate the plant-level PGA HCLPF capacity based on the most recently reported SCDF value of 4.9x10"6 per year. The HCLPF capacity was determined to be 0.395 g (about 1.6-times higher than the SSE PGA value), and the corresponding HCLPF Capacity Spectrum is provided in Table 5-1 and shown in Figure 5-1. Table 5-1: CGS Plant-Level HCLPF Capacity Spectrum Calculated Using the 2010 Seismic PAA Results 5% Damped, Frequency Spectral rHzl Acceleration rol 0.500 0.283 0.980 0.608 1.937 0.881 3.214 1.007 4.770 1.034 6.861 0.963 9.720 0.810 19.985 0.522 29.709 0.396 49.765 0.395 122 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 1.2 ........ C) ...... 1.0 c 0 +:i cu L.. Q) 0.8 Q) u u <C cu 0.6 '-.... u Q) c.. "' "C 0.4 Q) c.. E cu c 0.2 .. It) 0.0 0.1 10 Frequency [Hz] Figure 5-1: CGS Plant-Level HCLPF Capacity Spectrum Calculated Using the 2010 Seismic PRA Results 100 As seen in Figure 5-2, the latest PGA hazard curve is lower than the PGA hazard curve considered for CGS's earlier Seismic PRA studies (this is similar to how the old hazard curve exceeded the 2008 USGS hazard curve as well). Using the calculated 0.395 g plant-level (PGA) HCLPF capacity based on the 2010 Seismic PRA and the latest PGA hazard curve developed for this report, the revised SCDF tor CGS is estimated to be about 8.Sx 10-7 per year. As a result of being "screened in" in this report (see Section 4), the new SCDF value will, however, be more rigorously determined by carrying out new Seismic PRA that will be based on new seismic analyses and fragility analyses considering GMRS as the RLE spectrum. In any case, the (rather low) estimated value of 8.5x 10-7 per year is indicative of the plant's low seismic risk profile {and suggests that very few, if any, seismic upgrades will be needed as a result of the new Seismic PRA). 123 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Cll u c C1l 'C QI Cll u >< w .... 0 >-u c QI ::I C" LL ;;; ::I c c <( 1.E-02 1.E-03 1.E-04 1.E-05 1.E-06 1.E-07 1.E-08 0.01 -Old PSHA (NRC, 2010a) -New PSHA (Bechtel, 2015b) 0, 10 Ac:c:e leration (g) Figure 5-2: Comparison of New PGA Hazard Curve with that Used in Earlier CGS Seismic PRAs 124 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 6.0 Conclusions In accordance with the 50.54(f) request for information, a seismic hazard and screening evaluation was performed for CGS. A GMRS was developed solely for the purpose of screening for additional evaluations in accordance with the SPID (EPRI, 2013a). Based on the results of the screening evaluation, CGS screens in for a risk evaluation, a Spent Fuel Pool evaluation, and a High Frequency evaluation as part of the risk evaluation. As discussed in Section 5, previous Seismic PRA evaluations have already shown that the seismic core damage risk is low for CGS, and is expected remain low when new Seismic PRA evaluation is completed. 125 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure 7 .0 References Baker, J. W. (2010). Conditional mean spectrum: Tool for ground-motion selection, Journal of Structural Engineering, 137(3), 322-331. Bazzurro, P. and C. Allin Cornell (2004). Nonlinear Soil-Site Effects in Probabilistic Hazard Analysis, Bulletin Seismological Society of America, Vol. 94, No. 6, pp. 2110-2123. Boore, D. M., Joyner, W. B .. & Fumal. T. E. (1997). Equations for estimating horizontal response spectra and peak acceleration from western North American earthquakes: a summary of recent work. Seismological Research Letters, 68(1), 128-153. Darendeli, M.B. (2001 ). Development of a New Family of Normalized Modulus Reduction and Material Damping Curves, PhD Dissertation, University of Texas at Austin. Electric Power Research Institute [EPRI] (1993). Guidelines for Determining Design Basis Ground Motions: methods and guidelines for Estimating Earthquake Ground Motions in Eastern North America, Vols. 1-5, EPRI TR-102293. Electric Power Research Institute [EPRI] (2013a, February 28). Seismic Evaluation Guidance, Screening, Prioritization and Implementation Details (SPID) for the Resolution of Fukushima Near-Term Task Force Recommendation 2.1: Seismic, Report No. 1025287. Electric Power Research Institute [EPRI] (2013b, May 31 ). Seismic Evaluation Guidance: Augmented Approach for the Resolution of Fukushima Near-Term Task Force Recommendation 2.1 -Seismic, Report No. 3002000704. Energy Northwest [EN] (1993). CIVES-1: Seismic/Dynamic Analysis of Structural Components, Richland, WA. Energy Northwest [EN] (1995, June). Individual Plant Examination of External Events -Washington Nuclear Plant 2, Washington Public Power Supply System. Richland. WA. Energy Northwest. [EN] (1998, November). Geology, Seismology, and Geotechnical Engineering Report, Technical Memorandum, TM-2143, Richland, WA. Energy Northwest [EN] (2003, April). Design Specification for Division 202 -Structural and Seismic Design Requirements, Revision 1, Richland, WA. Energy Northwest [EN] (2011, January 28). Letter to U.S. NRC, Columbia Generating Station, Docket No. 50-397, Response to Request tor Additional Information tor the Review of the Columbia Generating Station, License Renewal Application. ADAMS Accession No. ML110330395, Richland, WA. Energy Northwest [EN] (2013a). Columbia Generating Station -Final Seismic Walkdown Summary Report, ADAMS Accession No. ML 13241 A278. 126 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Energy Northwest [EN] (2013b). Columbia Generating Station Final Safety Analysis Report, Amendment 62, Richland, WA. Idriss, I. M., and Sun. J. I. (1992). SHAKE91: A Computer Program for Conducting Equivalent Linear Seismic Response Analyses of Horizontally Layered Soil Deposits, Dept. of Civil and Environmental Engineering, Center for Geotechnical Modeling, Univ. of California, Davis. McGuire, R.K., W. J. Silva, and C. J. Costantino (2001). Technical Basis for Revision of Regulatory Guidance on Design Ground Motions, Hazard-and Risk-Consistent Ground Motion Spectra Guidelines, Prepared for Nuclear Regulatory Commission, NUREG/CR-6728. McGuire, R.K. (2004). Seismic Hazard and Risk Analysis, Earthquake Engineering Research Institute, Monograph MN0-10. Nuclear Energy Institute [NEI] (2014, March 12). Letter to U.S. NRG, Seismic Risk Evaluations for Plants in the Central and Eastern United States, ADAMS Accession No. ML 14083A584. Nuclear Regulatory Commission [NRG] (1973). Design Response Spectra for Seismic Design of Nuclear Plants. Regulatory Guide 1.60, Revision 1. ADAMS Accession No. ML003740207. Nuclear Regulatory Commission [NRG] (2007). A Performance-based Approach to Define the Site-Specific Earthquake Ground Motion, Office of Nuclear Regulatory Research, Regulatory Guide 1.208. ADAMS Accession No. ML070310619. Nuclear Regulatory Commission [NRG] (201 Oa, January). Appendix E to Environmental Report for Operating License Renewal Application, Columbia Generating Station Energy Northwest, Docket No. 50-397 License No. NPF-21, ADAMS Accession No. ML 100250666. Nuclear Regulatory Commission [NRG] (201 Ob, September 2). Safety/Risk Analysis for Gl-199, ADAMS Accession No. ML 100270582. Nuclear Regulatory Commission [NRG] (2012a, March 12). Letter to All Power Reactor Licensees et al., Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Recommendations 2.1, 2.3 and 9.3 of the Near-Term Task Force Review of Insights from the Fukushima Dai-lchi Accident. ADAMS Accession No. ML 12053A340. Nuclear Regulatory Commission [NRG] (2012b. April). NUREG-1437 Supplement 47, Generic Environmental Impact Statement for License Renewal of Nuclear Plants Regarding Columbia Generating Station, Final Report, ADAMS Accession No. ML 12096A334. Nuclear Regulatory Commission [NRG] (2014a, February). Letter to All Power Reactor Licensees et al., Supplemental Information Related to Request for Information Pursuant 127 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure to Title 10 of the Code of Federal Regulations 50.54(f) regarding Seismic Hazard Reevaluations for Recommendation 2.1 of the Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accident, ADAMS Accession No. ML 14030A046. Nuclear Regulatory Commission [NRG] (2014b, March 11 ). Letter to Energy Northwest, Columbia Generating Station -Staff Assessment of the Seismic Walkdown Report Supporting Implementation of Near-Term Task Force Recommendation 2.3 Related to the Fukushima Dai-ichi Nuclear Power Plant Accident (TAC No. MF0109), ADAMS Accession No. ML 14064A311. Pacific Northwest National Laboratory [PNNL], 2014, '"Hanford Sitewide Probabilistic Seismic Hazard Analysis", Report# PNNL-23361, Pacific Northwest National Laboratory, Richland, Washington, November 2014. Silva, W. J., N. A. Abrahamson, G. R. Toro, and C. J. Constantino (1997). Description and Validation of the Stochastic Ground Motion Model, Contract 770573, Report to Brookhaven National Laboratory, Associated Universities, Inc., Upton, New York. 128 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Appendix 2.2A Hanford Sitewide Probabilistic Seismic Hazard Analysis Analytical Process: SSHAC Level 3 The Hanford Probabilistic Seismic Hazard Analysis (PSHA) was conducted using processes that are appropriate for a Study Level 3, as presented in the guidance advanced by the SSHAC in NUREG/CR-6372, Recommendations for Probabilistic Seismic Hazard Analysis: Guidance on Uncertainty and Use of Experts-known informally as the Senior Seismic Hazard Analysis Committee (SSHAC) Guidelines-as well as the detailed implementation guidance provided in NUREG-2117, Practical Implementation Guidelines for SSHAC Level 3 and 4 Hazard Studies. The input to the PSHA to calculate the hazard at the baserock horizon consists of a seismic source characterization (SSC) model and a ground motion characterization (GMC) model. The SSC model defines the location and average rates of all potential future earthquakes of different magnitudes up to the maximum considered physically possible within each source. The GMC model predicts the expected distribution (defined by a logarithmic mean value and an associated logarithmic standard deviation) of spectral accelerations at a site due to a particular earthquake scenario. The PSHA calculations calculate the resulting ground motions from all possible earthquake scenarios and from sampling the full distribution of ground motion amplitudes, to obtain estimates of the total rate at which each level of acceleration is expected to be exceeded at the site. The quantity of data available regarding earthquake occurrence and ground motion generation in any region is never sufficient to unambiguously define the SSC and GMC models. One reason for this is that the completeness of the data, and sometimes its quality as well, are such that different experts assessing the data arrive at diverse interpretations, all of which may be technically defensible. Another reason is that the PSHA calculations will always consider earthquake scenarios for which no data at all are available, such as large-magnitude earthquakes at short distances from the site. These are examples of what is referred to as epistemic uncertainty, which reflects lack of knowledge regarding earthquake processes in general and in the study region in particular. This uncertainty is incorporated in the PSHA calculations. The SSHAC Level 3 process as given in current regulatory guidance defines clear roles and responsibilities for all participants. All technical assessments including the final hazard model and documentation are developed by Technical Integration (Tl) Teams that perform this work in two stages: evaluation and integration. In the evaluation stage, the Tl Teams assess available data, methods, and models both for their inherent quality and reliability, and specifically for their applicability to the region and site under consideration. In the integration phase, the Tl Teams construct logic trees that capture the center, the body, and the range of technically defensible interpretations. The work is conducted under the continuous observation of the Participatory 129 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Peer Review Panel (PPRP), which is charged with performing both technical and process reviews. The PPRP is responsible for reviewing the activities of the Tl Teams to ensure that the project satisfactorily considers available data, methods, and models; captures the center, body, and range of technically defensible interpretations; and adequately documents the technical bases of all decisions. PPRP concurrence that these goals have been met is the key indicator of successful compliance with the requirements of a SSHAC Level 3 process. The Hanford PSHA was conducted from April 2012 to October 2014. The project included a kick-off meeting in April 2012 conducted at PNNL facilities in Richland, Washington, and a tour of the Hanford region. Three workshops were held in Walnut Creek, California. Workshop 1 identified significant seismic hazard issues and data available to address those issues. Workshop 2 reviewed the databases assembled by the teams and discussed alternative models that related to the seismic source or ground motion models for the project. Workshop 3 provided an opportunity for the technical integration teams to present their preliminary SSC and GMC models to the PPRP and receive feedback. Hazard feedback based on hazard calculations using the preliminary models was also provided at Workshop 3. Seven working meetings (four for seismic source characterization and three for ground motion characterization) were held in Oakland, California, over the course of the project to facilitate interaction between the team members; due to family circumstance preventing travel, the first GMC Working Meeting was conducted as a conference call. As is typical of SSHAC Level 3 projects, the total number of participants entailed a large group of about 50 individuals. 130 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure Appendix 2.28 Hanford Sitewide Probabilistic Seismic Hazard Analysis PPRP Closure Letter 131 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure November 15. 2014 Mr. Robert W. Bryce Hanford PSHA Project Manager Pacific Northwest National Laboratory 902 Battelle Boulevard P.O. Box 999, MSIN K6-75 Richland, WA 99352

Subject:

Hanford Site-Wide Probabilistic Seismic Hazard Analysis Participatory Peer Review Panel Closure Letter

Dear Mr. Bryce:

Consistent with the requirements for a SSHAC1 Level 3 study, the Hanford Site-Wide (HSW) Probabilistic Seismic Hazard Analysis (PSHA) Participatory Peer Review Panel (hereafter "PPRP" and "Panel") is pleased to issue this PPRP Closure Letter containing our findings with respect to the HSW PSHA SSHAC Level 3 project. The Panel participated in the study following implementation guidance for a SSHAC Level 32 study. The Panel was actively engaged in all phases and activities of the Project's implementation, including final development of the Project Plan and planning of the evaluation and integration activities, which are the core of the SSHAC assessment process. Consistent with regulatory guidance for SSHAC projects, the role of the PPRP is to conduct a review of both the process followed and the technical assessments made by the Technical Integration (Tl) Teams. Accordingly, this letter documents the activities that the PPRP has undertaken in its review of the PSHA, its review of the adequacy of the process followed, and its findings relative to the technical adequacy of the PSHA. PPRP Activities for the PSHA Review The notion of a participatory peer review process entails the continual review of a project from its start to its completion. Thus, proper implementation requires adequate opportunities during the conduct of the study for the PPRP to understand the data being used, the analyses performed for the study, the Tl Team's evaluations and integration of the technical bases for its assessments, and the completeness and clarity of the 1Budnitz, R.J., G. Apostolakis, D.M. Boore, LS. Cluff, K.L. Coppersmith, CA Cornell, and P.A. Morris (1997). Recommendations for Probabilistic Seismic Hazard Analysis: Guidance on Uncertainty and the Use of Experts (known as the .. Senior Seismic Hazard Analysis Committee Report': or "SSHAC Guideline'), NUREG/CR-6372, U.S. Nuclear Regulatory Commission, TIC; 235076, Washington, D.C. 2USN RC (2012). Practical Implementation Guidelines for SSHAC Level 3 and 4 Hazard Studies. NUREG-2117, U.S. Nuclear Regulatory Commission, Washington, D.C. HSW PSHA PPRP C.lo.sure Letter 132 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure documentation. Participatory review also involves opportunities for the PPRP to provide its reviews and comments in written form during the conduct of the project, such that the suggestions and recommendations made by the Panel can be considered by the Tl Teams in a timely fashion prior to completion of the work. Written comments by the PPR P serve to document the review process and provide a vehicle for ensuring that all aspects of the SSHAC process have been adequately conducted. The activities of the PPRP for the HSW PSHA are summarized in the table below, which include written reviews during various stages of the project. Date PPRP Activity April 23, 2012 Kick-off Meeting and Site Tour: All PPRP members attended in person May 25, 2012 Submittal of PPRP written review comments on Kick-off Meeting July 23-27. 2012 SSHAC Workshop No. 1: All PPRP members attended in person as observers August 11, 2012 Submittal of PPRP written review comments on SSHAC Workshop No. 1 September 11, 2012 GMC Working Meeting No. 1a: PPRP representative attended via as an observer September 17-19, 2012 SSC Working Meeting No. 1: PPRP representatives attended in person as observers October 24, 2012 GMC Working Meeting No. 1b: PPRP representatives attended via eleconference as observers December 3-8, 2012 SSHAC Workshop No. 2: All PPRP members attended in person as observers January 3, 2013 Submittal of PPRP written review comments on SSHAC Workshop No. 2 February 18-21, 2013 GMC Working Meeting No. 2: PPRP representatives attended in person as observers February 25-28, 2013 SSC Working Meeting No. 2: PPRP representatives attended in person as observers August 13-16, 2013 GMC and SSC Working Meetings No. 3: PPRP representatives 3ttcndcd via teleconference and in person as observers September 17, 2013 Quaternary Geologic Studies Field Trip: PPRP representative attended n person as an observer November 11-15, 2013 SSHAC Workshop No. 3: All PPRP members attended in person as active participants December 7, 2014 Submittal of PPRP written review comments on SSHAC Workshop No. 3 January 13-16, 2014 SSC Working Meeting No. 4: PPRP representatives attended via eleconference and in oerson as observers January 13-17, 2014 3MC Working Meeting No. 4: PPRP representative attended in person as an observer March 6-7. 2014 PPRP Briefing Meeting on changes made to the GMC and SSC models Workshop No. 3 and on the PPRP written review comments on Workshop No. 3: All PRPP members attended in person as active :>articioants June 16, 2014 Submittal of PPRP written review comments on HSW PSHA Draft Report No. 1 June 18, 2014 Teleconference with Tl Teams to discuss PPRP written review comments on partially complete HSW PSHA draft report: All PRPP members attended HSW PSHA PP RP f.losure I .etter Page2 133 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure June 30, 2014 Submittal of PPRP written review comments on HSW PSHA Draft Repo11 No. 2 and on Tl Teams' responses to PPRP vvritten review comments on PSHA Draft Report No. 1 October 23, 2014 Submittal of PPRP written review comments on HSW PSHA Draft Repol1 No. 3 and on Tl Teams' responses to PPRP vvritten review comments on PSHA Draft Report No. 2 November 11, 2014 Submittal of PPRP written review comments on HSW PSHA Draft Repol1 No. 4 and on Tl Teams' responses to PPRP vvritten review comments on PSHA Draft Report No. 3 November 16, 2014 Submittal of HSW PSHA PPRP Closure Letter The activities listed above are those that were related directly to the conduct of the HSW PSHA and the development of the HSW PSHA report. Prior to the HSW PSHA work activities. the Panel was provided with the Mid-Columbia Project PSHA report and other documents related to Hanford Site seismic hazards. Although those documents provided a useful background for the Panel, this letter does not address these activities, because they lie outside of the SSHAC Level 3 process for the new HSW PSHA. The Panel concludes that its ongoing review and feedback interactions with the Tl Teams during the conduct the HSW PSHA project activities Fully met the expectations for a SSHAC Level 3 study. From the presentation of the plans for conducting the HSW PSHA at the outset of the project to the completion of the HSW PSHA report, the Tl Teams provided multiple and effective communications to the PPRP. Conference calls and written communications allowed the PPRP to fully understand the technical support for the Tl Teams' assessments. The Tl Teams provided written responses to PPRP comments documenting that all comments had been adequately considered during the conduct of the work and its documentation. SSHAC Process Review As explained in NUREG-2117 (USNRC, 2012), the SSHAC process consists of two important activities, described as follows: "The fundamental goal of a SSHAC process is to carry out properly and document completely the activities of evaluation and integration, defined as:

• Evaluation: The consideration of the complete set of data, models, and methods proposed by the larger technical community that are relevant to the hazard analysis.
• Jntegration: Representing the center, body, and range of technically defensible interpretations in light of the evaluation process (i.e., informed by the assessment of existing data, models, and methods)." These activities are essential to any SSHAC Level study and to both refinements to existing studies as well as new PSHAs (such as the HSW PSHA). HSW PSHA PPRP Letter 134 of 136 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure During the Evaluation phase of the HSW PSHA, the Tl Teams considered new data, models, and methods that have become available in the technical community since the previous HSW PSHA project was completed in 1995. Importantly, the Tl Teams also evaluated new site-specific data and methods for conducting site-response analysis, which is included as part of the HWS PSHA project as guidelines that ensure that there is a proper interface between the reference-rock hazard and the site-response analyses that will be conducted by the engineering consultants. The Panel concludes that the Tl Teams conducted an adequate evaluation process and that this process has been sufficiently documented in the PSHA report. During the Integration phase of the project, SSC and GMC models and site-response methodological guidance were developed for purposes of the HSW-specific PSHA. SSHAC guidelines require that the technical bases for the PSHA model be documented thoroughly in the PSHA report. The PSHA document demonstrates the consideration by the Tl Teams of the existence of seismic-source and ground-motion data and models that have become available since the previous HSW PSHA model was developed. The site-response guidelines entailed developing shear-wave velocity profiles for the Saddle Mountain Basalts and conducting a site-response analysis in light of models and methods that have been identified by the U.S. Nuclear Regulatory Agency and used in recent analyses for nuclear facilities. Documentation in the PSHA report confirms that the GMC Tl Team was aware of the applicable site-specific data, as well as models and methods for building the profiles, accounting for uncertainties, and carrying out the site-response analysis in order to develop these guidelines. Based on the review of the Evaluation and Integration activities conducted by the Tl Teams, as well as the documentation of these activities in the PSHA report. the PPRP concludes that the SSHAC process has been adequately conducted. SSHAC Technical Review The role of the PPRP in the review of the technical aspects of the project is specified in NUREG-2117 (USNRC, 2012) as follows: "The PPRP fulfills two parallel roles, the first being technical review. This means that the PPRP is charged with ensuring that the full range of data, models, and methods have been duly considered in the assessment and also that all technical decisions are adequately justified and documented. The responsibility of the PPRP is to provide clear and timely feedback to the Tl/TFI and project manager to ensure that any technical or process deficiencies are identified at the earliest possible stage so that they can be corrected. More commonly, the PPRP provides its perspectives and advice regarding the manner in which ongoing activities can be improved or carried out more effectively. In terms of technical review, a key responsibility of the PPRP is to highlight any data, models or proponents that have not been HSW PSHA ?PRP C:losure J .etter 135 of 136 Page 4 RESPONSE TO NRC REQUEST FOR INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(F) REGARDING RECOMMENDATION 2.1 OF THE NEAR-TERM TASK FORCE RECOMMENDATION 2.1: SEISMIC FOR SEISMIC HAZARD REEVALUATION AND SCREENING FOR RISK EVALUATION Enclosure considered. Beyond completeness, it is not within the remit of the PPRP to judge the weighting of the logic-trees in detail but rather to judge the justification provided for the models included or excluded, and for the weights applied to the logic-tree branches." Consistent with this USNRC guidance, the PPRP reviewed at multiple times during the project the Tl Teams' analyses and evaluations of data, models, and methods. These reviews included conference calls, post-workshop meetings, written comments, and the review of drafts of the PSHA report. Through these reviews, the PPRP communicated feedback to the Tl T earns regarding data and approaches that did not appear to have been considered, suggestions for methods being used within the technical community, and recommendations for ways that the documentation could be improved to include more discussion of the technical bases for the assessments. Examples of PPRP feedback regarding the technical aspects of the project can be found in the written comments provided at various times to the Tl Teams. The Tl Teams were responsive to the questions, comments, and suggestions made by the PPRP relative to the technical aspects of the project. Therefore, the Panel concludes that the technical aspects of the projects have been adequately addressed. Conclusion On the basis of the PPRP's review of the HSW PSHA, the Panel concludes that both the process and technical aspects of the assessment fully meet accepted guidance and current expectations for a SSHAC Level 3 study. We appreciate the opportunity to provide our review of the project. Sincerely, HSW PSHA PPRP Members Kenneth W. Campbell Chair William U. Savage HSW PSHA PPRP Closure Letter ... Brian S.-J. Chiou rfadLfar J. Carl Stepp 136 of 136 William R. Lettis Page 5 Focus Area Ouestions!T opics for DCPP Public Meeting 4128 In addition to providing a general overview of the SSC and GMC SSHAC Reports and March 2015 50.54(f) response for DCPP, please provide additional clarification on the following topics. Seismic Source Characterization 1. Summarize the key data used to constrain the slip rate of the Hosgri fault, including associated uncertainties. 2. Clarify how elements of the thrust/reverse interpretation for the San Luis Range Thrust are incorporated into the SSC. 3. Clarify how the rupture models are derived from the fault source geometry models. 4. Summarize the methodology used to define the equivalent Poisson rates. Ground Motion Characterization 1. Provide additional detail on the criteria used for the selection of the candidate ground motion prediction equations (GMPEs) for development of the common form median ground motion models for DCPP. Specifically, please elaborate on the basis for including GMPEs based on datasets other than NGA-West2. 2. Provide additional detail on development of the common functional form used to fit the candidate GMPEs. Specifically, please discuss how model parameters such as depth to Vs=1 kmls and 2.5 km/s (which are present in some of the candidate GMPEs) are accounted for in the functional form. 3. Provide additional detail on the approach for weighting the selected common form models as well as the criteria used to verify the physicality of the final models. 4. Provide additional detail on how the continuous distribution for total sigma (ass) was developed by combining the between-event and within-event aleatory variabilities. Site Response 1. Section 2.3.2.1 of the 50.54(f) submittal states that shear modulus and damping curves are not directly applicable to DCPP since analytical modeling is not used and that linear site effects are implicitly included in the empirical GMPEs for Vs30=760 mis. However, the NGA-West2 database has a limited amount of data for sites with Vs30 near 760 mis and for earthquakes with magnitudes and source-to-site distances similar to those dominating the hazard for DCPP. Please provide additional information on how these limitations in the NGA-West2 database are accounted for in the site response model for DCPP. 2. Section 2.3.6 of the 50.54(f) submittal describes the development of the site term for DCPP. For the calculations of between-event residuals, provide additional information on the criteria used to determine the appropriate distance range(+ and -Rrup) to the sample station. Please discuss the sensitivity of this distance range on between-event residual values. Please provide an example calculation that uses site-specific values to determine the values for including the epistemic uncertainty in the source term.

Focus Area Topics for CGS Public Meeting 6/2 In addition to providing a general overview of the SSC and GMC SSHAC Reports and March 2015 50.54(f) response for CGS. please provide additional clarification on the following topics. Seismic Source Characterization 1. Summarize the information used to constrain the slip rates on the YFTB faults, including: a. Methodology used to evaluate fault slip from topography including associated uncertainties in the ages and offsets. b. Rationale for excluding thin skinned seismo-tectonic models. c. How potential effects of surficial erosion were accounted for in the use of an average topographic profile to represent structural relief in individual faults. d. Bases for excluding listric fault geometries or potential for backthrust structures in structural relief model. 2. Summarize the information use to define the areal seismic source zones, including: a. Bases for zone boundaries b. Seismicity rate calculations. smoothing, and how uncertainty was captured as part of logic tree. c. Bases for Mmax distributions Ground Motion Characterization 1. Provide additional detail on the process used to define the target site kappa values and their uncertainties, including the rationale for logic tree weightings. 2. Provide additional detail on the Vs-Kappa corrections applied to the scaled backbone GMPEs, including: a. Rational for not applying a kappa correction for the subduction zone GM Ms b. Comparison of the Vs-kappa scaled median GMPEs and NGA-West 2 models c. Whether any observational data from the region was used to assess the kappa corrected GMPEs 3. Provide additional discussion regarding bases tor bump seen at T =0.1 sec in the mean tau values for the NGA-West2 models and the decision for smoothing through this peak in developing single-station sigma. Site Response 1. Provide additional detail regarding the characterization of the uncertainty in the site response analyses. specifically: a. Bases for only a single profile for the upper 525 ft b. Bases for two Vs profiles and their associated weights for the SMB stack c. Thickness of the interbed deposits including their lateral extent d. Adequacy of EPRI and Peninsular curves for covering range of nonlinear behavior for the Pasco Gravel e. Bases for randomizing the small strain damping for the basalt layers in the SMB stack in view of the uncertainty already incorporated into the determination of the site kappa 2. In view of the relatively high shear wave velocities(> 760 mis) and high confining stresses in the interbed layers, provide the rationale for not considering linear behavior of these materials and instead using a single sand curve which demonstrates significant non-linear behavior. 3. Provide additional detail regarding the decision not to implement a minimum site amplification value and the effect of this decision on the development of the uncertainty in the site amplification function as well as on the final hazard curves for the site. Focus Area Ouestions!T opics for DCPP Public Meeting 4128 In addition to providing a general overview of the SSC and GMC SSHAC Reports and March 2015 50.54(f) response for DCPP, please provide additional clarification on the following topics. Seismic Source Characterization 1. Summarize the key data used to constrain the slip rate of the Hosgri fault, including associated uncertainties. 2. Clarify how elements of the thrust/reverse interpretation for the San Luis Range Thrust are incorporated into the SSC. 3. Clarify how the rupture models are derived from the fault source geometry models. 4. Summarize the methodology used to define the equivalent Poisson rates. Ground Motion Characterization 1. Provide additional detail on the criteria used for the selection of the candidate ground motion prediction equations (GMPEs) for development of the common form median ground motion models for DCPP. Specifically, please elaborate on the basis for including GMPEs based on datasets other than NGA-West2. 2. Provide additional detail on development of the common functional form used to fit the candidate GMPEs. Specifically, please discuss how model parameters such as depth to Vs=1 kmls and 2.5 km/s (which are present in some of the candidate GMPEs) are accounted for in the functional form. 3. Provide additional detail on the approach for weighting the selected common form models as well as the criteria used to verify the physicality of the final models. 4. Provide additional detail on how the continuous distribution for total sigma (ass) was developed by combining the between-event and within-event aleatory variabilities. Site Response 1. Section 2.3.2.1 of the 50.54(f) submittal states that shear modulus and damping curves are not directly applicable to DCPP since analytical modeling is not used and that linear site effects are implicitly included in the empirical GMPEs for Vs30=760 mis. However, the NGA-West2 database has a limited amount of data for sites with Vs30 near 760 mis and for earthquakes with magnitudes and source-to-site distances similar to those dominating the hazard for DCPP. Please provide additional information on how these limitations in the NGA-West2 database are accounted for in the site response model for DCPP. 2. Section 2.3.6 of the 50.54(f) submittal describes the development of the site term for DCPP. For the calculations of between-event residuals, provide additional information on the criteria used to determine the appropriate distance range(+ and -Rrup) to the sample station. Please discuss the sensitivity of this distance range on between-event residual values. Please provide an example calculation that uses site-specific values to determine the values for including the epistemic uncertainty in the source term. Focus Area Topics for CGS Public Meeting 6/2 In addition to providing a general overview of the SSC and GMC SSHAC Reports and March 2015 50.54(f) response for CGS. please provide additional clarification on the following topics. Seismic Source Characterization 1. Summarize the information used to constrain the slip rates on the YFTB faults, including: a. Methodology used to evaluate fault slip from topography including associated uncertainties in the ages and offsets. b. Rationale for excluding thin skinned seismo-tectonic models. c. How potential effects of surficial erosion were accounted for in the use of an average topographic profile to represent structural relief in individual faults. d. Bases for excluding listric fault geometries or potential for backthrust structures in structural relief model. 2. Summarize the information use to define the areal seismic source zones, including: a. Bases for zone boundaries b. Seismicity rate calculations. smoothing, and how uncertainty was captured as part of logic tree. c. Bases for Mmax distributions Ground Motion Characterization 1. Provide additional detail on the process used to define the target site kappa values and their uncertainties, including the rationale for logic tree weightings. 2. Provide additional detail on the Vs-Kappa corrections applied to the scaled backbone GMPEs, including: a. Rational for not applying a kappa correction for the subduction zone GM Ms b. Comparison of the Vs-kappa scaled median GMPEs and NGA-West 2 models c. Whether any observational data from the region was used to assess the kappa corrected GMPEs 3. Provide additional discussion regarding bases tor bump seen at T =0.1 sec in the mean tau values for the NGA-West2 models and the decision for smoothing through this peak in developing single-station sigma. Site Response 1. Provide additional detail regarding the characterization of the uncertainty in the site response analyses. specifically: a. Bases for only a single profile for the upper 525 ft b. Bases for two Vs profiles and their associated weights for the SMB stack c. Thickness of the interbed deposits including their lateral extent d. Adequacy of EPRI and Peninsular curves for covering range of nonlinear behavior for the Pasco Gravel e. Bases for randomizing the small strain damping for the basalt layers in the SMB stack in view of the uncertainty already incorporated into the determination of the site kappa 2. In view of the relatively high shear wave velocities(> 760 mis) and high confining stresses in the interbed layers, provide the rationale for not considering linear behavior of these materials and instead using a single sand curve which demonstrates significant non-linear behavior. 3. Provide additional detail regarding the decision not to implement a minimum site amplification value and the effect of this decision on the development of the uncertainty in the site amplification function as well as on the final hazard curves for the site. Jackson, Diane From:Jackson, Diane Sent:22 May 2015 09:03:37 -0400 To:Akc, Jon;John Stamatakos;Miriam Juckett (mjuckett@swri.org);Sticvc, Alice;Plaza-Tolcdo, Meralis;Stova11, Scott;Weaver, Thomas;Munson, Clifford;Hil1, Brittain;Li, Yong;Giacinco, Joseph;Stirewalt, Gerry;Graizer, Vladimir;Devlin-Gill, Stephanie;Heeszel, David;Walsh, Lisa Cc:Kock, Andrea;Burke, John

Subject:

FY I Focus Arca Topics for Columbia Public Meeting (draft 2) Attachments: Focus Area Questions for DCPP Public Meeting 4-17 DSEA.docx, Focus Area Topics for CGS Public Meeting (draft 2).doc.:x

Dear R2.1 WUS reviewers:

Columbia is the next public meeting. It is scheduled for June 4 in the afternoon. Just as we did with Diablo focus areas, I want to share the Columbia focus areas with all of the team for information and consistency. Please take a look at them. I have re-included Diablo focus areas for completeness and convenience. Palo Verde focus areas are coming along and are next. Public meeting June 9. After the public meetings, our next milestone is Questions by the end of summer. Please target mid-August. The SRB will be reviewing the questions for consistency and level of detail. This system worked well for CEUS and in the ESEP interim evaluation reviews which are on-going. For a data point comparison, of the CEUS plants, about seven received questions. I would not be surprised if all 3 WUS sites have questions due to the complexity of the review. However, keep in mind, these are 50.54(f) reviews. We will use softer wording in the questions. Our goal is to make sure we understand what they did and have sufficient information to make a judgment if they adequately characterized the site and that the hazard is suitable to develop the SPRA. I understand this is still not a small task; it is a large task. However, as we discussed, the level of review should not be to the depth of a licensing review. Regards -Diane g)Uuie Jacll,jon, Chief Geosciences and Geotechnical Engineering Branch 2 (RGS2) Division of Site Safety and Environmental Analysis ( DSEA), Office of New Reactors ( N RO) US Nuclear Regulatory Commission +1301-415-5641; office: T-7 D3; mail stop: T-7 F3 NRC -One Team -One Mission 1 5 ---------.-------------.-----------, I Columbia r .. ! 1.2 .. GMRS, Tbl 2.4-1 1.1 ; SSE, Tbl 3.1-1 / __ -\-.,....-------1_0 -*RG 1.60, 0.25g * -;-\ .,_ ___ _ c; ***** HCLPF, Tbl 5.1 I .*. *. \ -0.9 . ----.---,-----O.B 1 -*IPEEE, 2x SSE / _ __ _ cu ** l . ' *' I... 0 7 .:* ** I-. --------;-. 8 0.6 -----' J 0.5 :*.*------* " 'ta:: , -1: ---i 0.4 -:-. ----* 0.3 :-: ----* 0.2 ----* 0 1 J ,,., . .,,.' ,)_...,. ---0.0 :.--0.1 ------....... ::mr:: ******* ______ ...,. ------1.0 10.0 100.0 Frequency (Hz) l'rotecting l>eople and the r:uvirou1ncnt Near-term Task Force Recommendation 2.1 (R2.1) Seismic Hazard Evaluation Energy Northwest Columbia Generating Station Public Meeting References and Protecli**g People and the Enviromnent Logistics

• Public Meeting Agenda -ML 15142A452
• NRC Presentation Slides -MLXXXXXXXX
• Licensee Presentation Slides -MLXXXXXX
• Licensee Hazard Report -ML 15078A243
• Screening and prioritization results -ML 151138344
• Meeting Feedback Form (request from njd2@nrc.gov)
• Meeting Summary to be issued within 30-day 2

\-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent Meeting Purposes

• Gather additional information based on early identification of areas where additional technical information will support the staff's review
• Gain a better understanding of how the licensee conducted their evaluation 3

\-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent Outline

• Overview of Recommendation 2.1 -Response to NRC 50.54(f) letter
• Screening and Prioritization results
• N RC approach to seismic hazard characterization reviews for Western US (WUS) sites
• Review schedules and timeline 4

\-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent Seismic R2.1 Process Ensures Clarity, Consistency, and Informed Regulatory Decisions PHASE 1 INFORMATION GATHERING STAGE 1 Interact with Industry on Hazard and Risk Evaluation Guidance CELIS Licensees submit Site Response (9/2013 & 3/2014) Screened-in plants complete Expedited Interim Evaluation (CEUS:12/31/2014;WUS:1 /2016) and Risk Evaluation (Group 1: 6/2017) NRC reviews Risk Evaluation -----------------------------* ,----------------PHASE 2 DECISION-MAKING N RC makes Regulatory Decisions as Needed *Safety Enhancements

• Backfit Analysis *Modify Plant License -----------------5 Seismic Screening and -. .. m, ... ,,. ... ..... ro._., Prioritization resu Its
• NRG Letter issued for WUS sites on May 13, 2015 (ML 151138344)
• Columbia has screened-in for seismic risk evaluation and limited scope evaluations -Review Group 1 plant
• No immediate safety issues identified
• Information supports safety assurance allowing additional time to complete the seismic risk evaluation 6 NRC Review of SSHAC -. .. m, ... ,,. ... ..... ro._., Studies for WUS Sites
• Did SSHAC process follow NRC guidance?
• How effective was the peer review panel?
• Have all applicable data been considered?
• Were data uncertainties identified and considered?
• Was an appropriate range of applicable models considered?
• How were models selected and weighted in the analysis?
• How were models assembled into the PSHA? 7

\-* U.S.NRC NRC Review of Source Mode Is for WUS Sites

• How were seismic sources identified? -Geologic mapping -Geophysical observations -Earthquake catalog
• How were seismic sources characterized? -Geometry (location, length, dip) -Range of magnitudes -Faulting style (normal, reverse, strike-slip) -Slip rate and recurrence models -Complex rupture scenarios 8

\-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent NRC Review of Ground Motion Models and Site Response for WUS Sites

• Do final ground motion models capture a reasonable range of alternative models?
• How were sources of uncertainty captured in model development?
• How were ground motion models adjusted for local site geology?
• Does site response analysis cover a reasonable range of alternative soil/rock properties?
• How was uncertainty in site response analysis incorporated into final probabilistic hazard curves? 9 Timeline * '1 March 2015: WUS Hazard Submittals * '1 May: Screening and prioritization letter * '1 May/June: Public meetings
• Late summer/early fall: Staff questions
• December: GMRS suitability Letter
• January 2016: ESEP Interim Evaluation
• April 2016: ESEP review response
• Summer 2016: Document Hazard review
• June 2017: Risk Evaluation submittal (Grp 1) 10

\-* U.S.NRC Break for NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent Staff Alignment

• 15 -20 minute planned break for NRC staff alignment to support meeting wrap-up
• Meeting to resume at 3:00pm (Eastern) or 12:00pm (Western) 11 Opportunity for Public Protecli**g People and the Enviromnent Questions or Comments
• Additional Questions? Please ask us at: JLD _PublicResource@nrc.gov 12

\-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent List of Acronyms

• CEUS -Central and Eastern United States
• ESEP -Expedited Seismic Evaluation Process (for Interim Evaluation)
• GMRS-Ground Motion Response Spectrum
• NRC-U.S. Nuclear Regulatory Commission
• NPP-Nuclear Power Plant
• NTIF -Near-Term Task Force
• PSHA -Probabilistic Seismic Hazard Analysis
• SFP -Spent Fuel Pool
• SMA -Seismic Margins Analysis
• SPID -Screening, Prioritization, and Implementation Details SPID
• SPRA -Seismic Probabilistic Risk Assessment
• SSC -Structures, Systems and Components
• SSHAC -Senior Seismic Hazard Analysis Committee
• SSE -Safe Shutdown Earthquake
• SPID -Screening, Prioritization, and Implementation Details
• WUS -Western United States 13

\-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent Backup Slides 14 Additional WUS Protecli**g People and the Enviromnent Seismic Hazard Reports Public SSHAC Report

• Hanford Sitewide (PSHA including Columbia Generating Station) http://www.hanford.gov/page .cfm/Official Do cuments/HSPSHA 15

\-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent Guidance Documents

• Two main guidance documents proposed by industry and endorsed by the N RC
• Screening, Prioritization, and Implementation Details (SPID) -Submitted by EPRI on November 2012 -Endorsed by NRC on February 15, 2013 -EPRl-1025287 (ML12333A170)
• Seismic Evaluation Guidance: Augmented Approach (aka Expedited Approach) -Submitted by EPRI on April 9, 2013 -Endorsed by NRC on May 7, 2013 -EPRl-3002000704 (ML 13102A 142) 16

\-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent Hazard Development Expedited Interim Evaluations Risk Evaluations Higher Priority Lower Priority Hazard Analyses Expedited Interim Evaluations 2012 I I Schedule for Seismic Hazard and Risk Evaluations 2013 2014 2015 2016 2017 2018 2019 2020 CEUS '1

• wus '1
• All plants I CEUS I mods I
• 1 wus mods Only plants I with new
• I Group 1 I I Risk Evaluations '1 Staff acknowledgement to use GMRS for risk evaluation seismic hazard exceeding design basis Group 2 Group 3 (as needed) e Staff Assessment or response -17 Summary of Recent Seismic Hazard Investigations at Diablo Canyon Power Plant The 2015 seismic hazard analysis is different from analyses in 2014 and earlier -Considers likelihoods that ground motions will occur (earlier assumed will occur) -Uses new approach to model how energy moves from source to beneath site -Uses more site-specific information to calculate ground accelerations at surface The 2015 seismic hazard is higher than calculated in 2011 and 2014 analyses -Better understanding of site-specific conditions -Consideration of earthquakes from linked faults (e.g., Shoreline+San Simeon+Hosgri) -Improved models for how energy travels from source to site New data from site-specific investigations is used extensively in 2015 seismic analysis -Studies directed by CA Assembly Bill 1632 -Results presented in PG&E Central Coastal California Seismic Imaging Project Report -Reviewed by the Independent Peer Review Panel and recent SSHAC program Diablo Canyon is safe to operate while additional risk investigations are completed in June 2017 -New GMRS does not exceed the well-documented safety margins for Diablo's design -Safety margin analyses from Long-term Seismic Program reviewed by NRC in 1991 -Sufficient detail to provide NRC assurance that Diablo Canyon can operate safely Chronology of Key Seismic Hazard Issues at Diabfo Canyon 1969 Construction Permit for Unit 1, design basis 0.4g Double Design Earthquake 1971-77 Characterization of Hosgri Fault offshore DCPP 1973 N RC issues Apdx A to 1 O C FR Part 100 (SSE-G DC2), and RG 1 . 61 (damping) 1977 PG&E applies for Operating License, includes Hosgri evaluation in design 1984 NRG issues SSER 7, grants OL w/ Lie Condition for Long-Term Seismic Program 1988 PG&E issues LTSP report, includes seismic PRA and margins assessment 1991 NRC extensively review L TSP report, no change to design basis, issues SSER 34 1992-2006 Cooperative seismic research program with USGS 2008 Shoreline fault identified from offshore earthquake alignment 2008 PG&E uses LTSP methods to show Shoreline bounded by previous analyses 2009 NRG RIL-09-01 deterministic analyses confirm PG&E conclusions 2011 PG&E issues detailed Shoreline fault report, ground motions bounded previously 2011-12 Two nonconcurrences on Inspection Reports for seismic hazard analyses Feb 2012 NRG RIL-12-01, additional deterministic analyses confirm PG&E conclusions March 2012 NRC issues 50.54(f) letter to all licensees. DCPP compare DDE to GMRS 2013-14 D PO on DCPP seismic hazard issues: N RC refutes conclusions Sept 2014 PG&E issues updated Shoreline report, conducts operability evaluation Dec 2014 NRC inspects PG&E operability evaluation, confirms seismic safety at DCPP Mar 2015 PG&E submits 50.54{f) response Tl Team I PM notes Hazard Sensitivity
• Make the tornado plots consistent for DCPP and PVNGS Directivity
• Directivity -Hazard sensitivity
• Currently only for the original distribution of hypocenters
• Justify the use of a single directivity model -Show the hazard sensitivity with the new hypocenter distribution that is more concentrated on unilateral -Apparent sharp changes in the contours
• Check the maps of the parameterized model -Does it still have the sharp edges?
• Demonstrate the the contours are appropriate Median Models
• Common form The break point in the mag scaling may be related to an important seismological parameter and could be treated as a random variable
• Demonstrate that the current approach adequately captures the range of models that would be found if the break point was treated as a random parameter DCPP
• Justify the mag range (MS-m8) used for fitting the GMPEs with a common model
• Would adding a point at M4.5 make a difference to the covariance? PVNGS
• Demonstrate that the upper mag range (M7) used for fitting to the common form is adequate if SSC has magnitudes up to M7.4?
• May be alternative ways to capture the ZTOR dependence without introducing a 0,1 indicator variable, but getting a better fit on the FW side Median Models
• Generating common form models -Improve documentation
• Document that the COV was doubled to broaden the distribution for generating the 15,000 models
• But used interpolated models which are correlated
• The doubling of the variance approximates the effect of the correlation on the covariance. -Justify not adding the additional epistemic uncertainty to the COV for generating the 15,000 models
• Show a PSA histogram (slice at one scenario) with COV and 2 times the COV -Compare to the distribution that would result using the COV (not doubled) but adding the AV epistemic uncertainty. -Does the doubling of the COV capture that range?

Median Modes

• CDF checks -Justify the use of the representative model rather than the suite of models in a region.
• Check if the CDF sensitive to the use of the representative model rather than all of the models that fall into a region
• 5-95 range plots -Show the range from the original GMPEs, in addition to full range from GMPEs with +-2sigma -Show insensitivity to cell boundaries Logic tree weights
• Justify (explain) why the three point distribution has weights of 0.2, 0.6, 0.2 rather than 0.185, 0.63, 0.185 as given in referenced paper.

Weights on approach for sammon's maps weights

• Document what was being checked in CDF plots for constraining the 60-40 weights on resid approach and likelihood approach -Is it the slope, the 5% and 95% or other metrics? -Show the fractiles of the original GMPEs (w/o unc)
• Improve justification for the weights on the data sets and prior. -More important for PVNGS -Think about likelihood for European data using fixed sigma but with more variable data -DCPP hazard is not very sensitive to these weights Tau model
• What is the justification for using the smoothed CV14 tau in computing the average rather than using the raw unsmoothed values?
• Explain how the effect of the bump in tau will be captured somewhere in the process of getting the site-specific ground motions -Add examples showing how the bump moves to site terms if RE for both site and event are included -Document how this should be addressed in the site response Phi Models
• Justify not using the PEGASOS phiSS models -Why are they only used for comparisons?
• Documentation of phi -Make clear that all data is used to get the site terms, but a subset of the deltaWs is used for the PHISS (based on M,R)
• Justify why there should be a reduction (change in slope) in PHISS from 5-10 sec -Consider smoothing through this.

PhiSS and PhiSP-R

• Justify using a constant phiSS with mag when the 5 NGA models used for this region all have mag dependent phi Limited mag range and dominated by larger magnitudes for this source. Some NGA models have constant phi for M>5.5 for M>6
• Address SSC changes Changes to the SSC zonation affect the classification of one event used for the path This revision is now final
• Expand documentation for how the COV of phiSP-R is computed Justify why only four periods between 0.2 and 2 sec were used and not more as used for phiSS The values at T=0.2 and 0.5 are different and the fit from 0.5 to 1. sec is influenced by the value at T=0.2 sec. Justify why this captures the period dependence in the main range of interest {T>0.5 sec)

PhiSS (greater AZ)

• Revise terms on logic tree -"constant" should be "mag independent"
• Revise phiSS versus mag plots to drop the M4 to MS points as these were not used
• Justify why the apparent mag dependence from MS to M6 is not considered as evidence for a mag dependent phiSS
• For the comparison to PhiSS from Swiss study, document that the Swiss study did not address the bias due to sample size Spatial correlation effects on tau and phi
• Not currently included in documentation -Model is not fully developed -Will not be formally included as a branch, but consider putting extra weight on the upper branch of total sigma Sigma Sensitivity
• DCPP -Modify plots to use symbol size to represent weights consistent with PVNGS plots
• PVNGS -Sensitivity to tau for regions 1, 2,3 need to be checked -Make sure the numerator has the hazard from all source (include the mean hazard from the other region)

Phi logic tree

• Greater AZ phi -Justify why the European data is given lower weight for phi, but higher weight for the median -Justify the mag-independent phiSS for full range of magnitudes M>S.
• If there is a mag dependence, this approach may underestimate the phi for MS.

Other Issues Missed?

• If PPRP has noted other deficiencies (unclear documentation or inadequate justification), provide short letter to Tl team by Friday Jul 25, or it will not be addressed for the Aug 11 draft report
• Lumpy, discretized, hazard sensitivity results for Palo Verde median models Evaluation of Alternative Directivity Models for DCPP Introduction The simplified directivity model by Watson-Lamprey (2015) was used to conduct the hazard sensitivity studies. The Watson-Lamprey model is intended to be a simplified version of the Chiou and Youngs (2014) directivity model that is part of their GMPE (called CY14). To incorporate directivity into hazard calculations, the direct method is to integrate over the hypocenter location for each rupture and add the directivity effects on the median ground motion for each hypocenter location. This leads to a range of median ground motion values for a given rupture (magnitude, dimension, location) but with different hypocenters on the rupture plane. The Watson-Lamprey model simplifies the application to hazard by pre-computing the range of median ground motions for the distribution of hypocenter for a given rupture and site location. The range of directivity factors for the median is parameterized by a mean value and the standard deviation. This allows for a faster implementation in the hazard code because there is no need to include the integration over hypocenter location in the hazard code. The cost of this simplification is that is may not capture all of the features of the CYl 4 model for the specific site/source geometry for DCPP. This sensitivity study compares the hazard at DCPP using the full CY14 directivity model and the simplified Watson-Lamprey directivity model. Hypocenter distribution The distributions of the along-strike and down-dip locations of the hypocenter are based on the distributions shown in Figures 1 and 2 shown below. For this sensitivity study, the following hypocenter distributions are used: For strike-slip earthquakes, the "Appendix D" distribution is used for the strike distribution and the CY2008 distribution is used for the down-dip distribution. For reverse earthquakes, the uniform distribution is used for the along-strike distribution and the CY2008 distribution is used for the down-dip distribution. For both strike-slip and reverse earthquakes, the hypocenters are restricted to be at least 10% of the rupture length from the ends of the rupture as recommended by Chiou and Spudich (2013) (Sec 6.3, page 90). In the hazard code, these distributions are discretized into 10 locations along strike and 3 locations down dip. The discrete probabilities for these locations are given in Table 1.

Hazard code implementation The CY14 directivity model was implemented into PG&E hazard code (Haz43b). This hazard code was previously set up to include directivity by including integration over the hypocenter location along strike and down dip. In general, implementing the CY14 directivity model into haz43b is straight-forward with one exception: computing the mean OPP parameter for a given rupture. The CY14 directivity model uses the difference in the OPP at the site of interest from the mean OPP for sites located at the same RRuP for a given rupture. This requires finding a set of sites that are at the same RRuP and represent uniform sampling of the locations. There was not an obvious simple way to find a uniform sample of sites at a given RRuP from an arbitrary rupture. Therefore, a brute force method was used to implement this into Haz43b. For each rupture, a uniform grid of sites was generated along the rupture (sampling both sides) with a grid step size of 0.5 km. The RRur was computed for each site and those sites with an RRuP that was within 1 km of the RRuP for the DCPP site were selected for averaging the OPP. There is probably a faster way to do this, but this method was the easiest to implement at the cost of computation time. Sensitivity results The CY14 directivity model was developed for the CY14 GMPE. Therefore, the hazard was computed using the CY14 GMPE. Three alternative directivity models are used to compute the hazard: 1) No site-specific directivity added (e.g. !:illPP = 0) 2) The CYl 4 directivity model is added using the hypocenter distributions listed in Tables 1 and 2. 3) The simplified Watson-Lamprey directivity model is added The hazard was computed for a period of T=3 sec. At a period of 3 sec, the Hosgri is the main contributor to the hazard: the Hosgri contributes 60% of the hazard at 1 E-4 and 75% of the hazard at lE-5. Therefore, the first sensitivity study is based on the impacts on the hazard from the Hosgri fault source. A second sensitivity study that includes the directivity effects using the CY14 model for all sources could not be completed in time for inclusion in this report, but it will be included in the final version of this sensitivity study. To show the effect of two directivity models, the ratio of the hazard with directivity to the hazard without directivity is shown in Figure 3. In the lE-3 to lE-4 hazard level range, the CY14 model and the Watson-Lamprey model give similar factors of 1.00 to 1.10. At lower hazard levels (lE-6), the models become more different with the CYl 4 model showing increasing directivity effects at lower hazard levels while the Watson-Lamprey model show a decrease to back to unity. From this comparison, the TI team concludes that the directivity effects based on the simplified Watson-Lamprey model will give reasonable results in the lE-4 to lE-5 range, but it underestimates the directivity effects at the lE-6 hazard level. The decision to exclude directivity effects based on the small effect on the hazard based on the sensitivity studies that used the Watson-Lamprey simplified model is justified for hazard above the lE-5 level, but it should be checked further for the lower hazard levels. The hazard results are used to generate the ground motion response spectra (GMRS) which uses the lE-4 and lE-5 UHS. For this application, the Watson-Lamprey simplified model gives reasonable results. References Chiou, B.S.-J., Spudich P. (2013). The Chiou and Spudich NGA-West2 directivity predictor DPP, PEER Report 2013/09, Pacific Earthquake Engineering Research Center, University of California, Berkeley, CA. Chiou, B.S.-J., and Youngs, R.R. (2014). Update of the Chiou and Youngs NGA Model for the Average Horizontal Component of Peak Ground Motion and Response Spectra, Earthquake Spectra, Vol. 30(3), 1117-1153, DOI: 10.1193/072813EQ5219M. Watson-Lamprey, J. (2015). Capturing Directivity Effects in the Mean and Aleatory Variability of the NGA-West 2 Ground Motion Prediction Equations, Pacific Earthquake Engineering Research Center PEER Report (in preparation). Table 1. Discrete distribution used for hypocenter location along strike Hypocenter Probability for Probability for location along Strike-slip Reverse strike (ratio to ruptures ruptures rupture length) 0.10 0.13 0.1 0.19 0.10 0.1 0.28 0.09 0.1 0.37 0.09 0.1 0.46 0.09 0.1 0.54 0.09 0.1 0.63 0.09 0.1 0.72 0.09 0.1 0.81 0.10 0.1 0.90 0.13 0.1 Table 2. Discrete distribution used for hypocenter location down dip Hypocenter Probability for Probability for location down Strike-slip Reverse dip (ratio to ruptures ruptures rupture width) 0.25 0.15 0.15 0.50 0.35 0.35 0.25 0.50 0.50 1.4 1.2 0.4 a.z 0'------------' 0 0 1 0 2 0 3 0.4 0.5 0 6 0 7 0 8 0 9 I Hypoccniral X Rati() -CY2008 -Appendi* D -Uni1orrn Figure 4.1 Hypocenter distributions along strike for strlke*slip ruptures. 1.8 1.6 1.4 1.2 E 1 .. '50.8 G. 0.6 0.4 0.2 o.._ ________ __, 0 0.1 0.2 0.3 0.4 0.5 0.6 0 7 08 0.9 1 0()wn Dip Ratio -CY2008 -Uniform Figure 4.2 Hypocenter distributions down dip for strike-slip ruptures. Figure 1. Alternative hypocenter distribution models for strike-slip earthquakes given in Watson-Lamprey (2015). The top frame gives the distribution along strike and the bottom frame gives the distribution down dip. (Figure from Lamprey, 2015) 1.4 1.2 1 ..... ii .li 08 e (I_ 0.6 0.4 0.2 O'------------' 0 0.1 0.2 0.3 0.4 0.5 0.5 0 7 08 0.9 1 Hypucenlr*I X R*lio -CY200B -umrmm Figure 4.3 Hypocenter distributions along strike for reverse ruptures. 1.8 1.6 1,4 1.2 ,., 1 z £as 0.6 0.4 0.2 o..__ ________ _... 0 0. 1 0.2 0.3 0.4 0.5 0.6 0. 7 0.8 0.9 1 Down Dip Ral*O -CY20CJB -umro1m Figure 4.4 Hypocenter distributions down dip for reverse ruptures. Figure 2. Alternative hypocenter distribution models for reverse earthquakes given in Watson-Lamprey (2015). The top frame gives the distribution along strike and the bottom frame gives the distribution down dip. (Figure from Watson-Lamprey, 2015) 2 (.) 1.8 7i 1.6 I-..... 0 -1.4 *5 1.2 ..... 0 ..... 1 0 -..... 0 t5 0.8 <'1 LL Q) <'1 0.6 (.) Cl) -e 0.4 <'1 J: 0.2 0 1 E-2 ---------WL Dir I no Dir (CY14 GMPE) CY14 Dir I no Dir (CY14 GMPE) 1E-3 1E-4 Annual Hazard 1E-5 _/ 1 E-6 Figure 3. Hazard ratio for directivity effects for the Hosgri fault (using the full Hosgri SSC model) with the CY14 GMPE for both the median and the standard deviation. Comment Response Table Comment Location in Text PPRP Comments Tl Team Responses Number 1. General comments The report lacks terminological and stylistic consistency. This deficiency A comprehensive check of the terminology and style was affects its readability and sometimes renders meanings ambiguous. Just done for all chapters and all appendices. as examples: the report uses inconsistent abbreviations for the NGA West2. inconsistent symbols for some variables (e.g. tau, Tau.<), inconsistent names to refer to data sets. Please edit for overall consistency of style, terminology and notation throughout the report, including main chapters and appendices. 2. General comments Acronyms, technical terms, and individual variables are not consistently A check was made that the acronyms are all defined at defined when they are first used. Please provide a list of acronyms, a list the first use and that they are consistently used of variables. and a list of terms that the reader can refer to when throughout the chapters and appendices needed. Please also define these acronyms, parameters. and terms the first time that they are used in the report, after which they need not be defined again as long as the reader can refer to a list as necessary. For example, ASK14. BSSA14, CB14, and CY14 are used throughout the report and are defined by their full references sometimes and only their acronyms at other times. Please provide the full references the first time they are used, include them in the list of acronyms, then only reference them by their acronyms after that. 3. General comments There is very inadequate cross-referencing between chapters and Detailed cross referencing is added between chapters. and between the main chapters and the appendices. While there is no between chapters and appendices objection to putting technical detail in the appendices. each report chapter must be coherent and self-contained in and of itself in the sense that any appendices that it relies on must be incorporated by explicit references, with sufficient connective text to be readable and understandable. When results from such an appendix are referenced, please cite the relevant section and/or figure or table number within the appendix. 4. General comments Please consider streamlining the presentation by absorbing some The following appendices have been absorbed into the of the short appendices with few figures, or that are redundant with main report Appendix L, M. and N. other report chapters or appendices. into the appropriate main chapters. In that case, only those appendices that are lengthy, present complex methods or analysis, or contain a large number of figures or tables, could be retained as separate entities. 5. General comments There are many places throughout the report where there are The text is reviewed to identify this type of statements, and statements of what was done but not why it was done. It is a additional text explaining why it was done is added. requirement of the SSHAC process that the justification and basis for each decision by the Tl Team be fully documented. Please provide a description of the Tl Team's assessment and evaluation that was done to arrive at the methods, models, and decisions that form the bases for the statements and models presented in the report and appendices. 6. General comments Because the 3-point discretization scheme for representing a continuous A new Appendix has been added that provides the distribution was frequently used in the report, please provide a brief background and references for three point distributions used discussion of its origin. properties. and accuracy, so that that discussion by the Tl Team This appendix include the three point can be used as a reference throughout the report. distributions for both normal and chi-squared distributions.

7. General comments Please consider providing a special treatment of the scaled Chi-square Same as response to General comment 6 distribution in the report. It is invoked frequently, and such a treatment could serve as a reference throughout the report, and also could make related chapters more accessible to the full range of readers. As noted later in this review. the presentation of the topic in Chapter 13 is unmotivated, lacks clarity. and its equations are made impenetrable by numerous notational errors. 8. General comments The term "proponent moder is used a number of times in the report in The confusion occurs because we have used the term ways that seem to be inconsistent with the term's usual meaning in a "proponent model" for both the existing models and new SSHAC study. In the SSHAC context, the term is usually reserved for models developed by the Tl Team or under the direct models presented by proponent experts, for subsequent evaluation by direction of the Tl Team. The text has been revised to only the Tl Team. In each instance, if the intended usage corresponds to the use "proponent model" for previously existing models that SSHAC standard, please ensure that it is clear why. If it does not, it is are evaluated by the Tl Team. New models developed by important to avoid the term, as it is misleading. the Tl Team or under the direction of the Tl Team are called "Tl Team models 9. General comments It is appropriate to discuss the center, low and high values of variables All Tl T earn evaluations of weights were moved to the when a model is first discussed, but please consider consistently chapters describing the logic trees. deferring discussion of the weights to the chapter that discusses the related logic tree. The current draft is inconsistent in this regard. CHAPTER 7 GMC Models for the Sigma 10. Section 7 .1 , Page 7-Please note that Anderson and Brune (1999) was cited but not included The missing references have been added 1, Paragraph 1. Line 4 in the references section of this chapter 11. Section 7.1, Page 7-Please clarify that q>ss and q>so-R are alternative (mutually exclusive) Text revised to better explain the relation between PhiSS 1, Paragraph 1. Line 6 models for PVNGS (associated with non-path-specific median and path-and PhiSP-R specific median models, respectively, and also please reference appropriate sections from chapter(s) on median motion. 12. Section 7. 1 , Page 7-Please replace "/" with "and" to avoid any confusion that q>ss I 'l>s*-R is a Text revised as recommended 1, Paragraph 1, Line 7 ratio of these two terms. 13. Section 7. 1 , Page 7-For uniformity of coverage, please include in the outline in this section a Reference to chapter 13 added to chapter 7 to explain how 1, Paragraph 1, Line reference to chapter 13 where the combining and resampling of tau and the phi and tau models are simplified to a total sigma logic 8-9 phi is discussed. tree 14. Section 7.1, Page 7-Please consider whether Miller and Rice (1983) is correc11y cited here. New Appendix P addresses 1he use of a 1hree poin1 sample 1, Paragraph 1. Line 9 Miller and Rice propose moment-preserving sampling of continuous of the distribution and clarify if the quotation is appropriate or distributions at Gaussian points. Is this reference relevant to the not. approach actually used in this report? 15. Section 7. 1 , Page 7-It is not clear whether the term "sigma is meant to represent a generic The text was modified to avoid the use of generic "sigma". 1, Line 10 term for all standard deviations or to represent a specific standard Sigma will only be used for the total standard deviation (e.g. deviation. Please define the term "sigma" the first time it is used and Chap 13) include it in the list of terms 16. Section 7.1, Page 7-It would be helpful to also give a guide here to the relevant appendices The key appendices (L, M, N) for the phi and tau are 1, End of first covering sigma topics that are referenced in 1his chapter. Please note in incorporated into chap 7 (see General comment 4) paragraph particular that the division of the (jlss and (jls*-R details between two different appendices (N and L, respectively) tends to obscure their close relationship, and any such confusion would be mitigated by an overview discussion of the sigma appendices at this point in the report. 17. Section 7.1.1, Page Please explain that the site-to-site variability that is removed in order to This is addressed in the chapter dealing with the application 7-1, 1st Paragraph of estimate single-station sigma needs to be included as uncertainty in the guideline. A reference to this guideline added to Chap 7. Section, Line 4 site-specific site-response analyses, whether they are empirical or analytical.

18. Section 7.1.1, Page Please include citable references to the PSHA studies mentioned in this Missing references were added 7-1, 1st Paragraph of sentence (PEGASOS Refinement Project, Thyspunt Nuclear Siting Section, Last Project. BC Hydro PSHA Project. and Hanford PSHA Project) sentence 19. Section 7. 1 . 1 . Page Please justify your criterion of using "a minimum of 3 recordings". Why is The difference in the min number of recordings is based on 7-2, First Paragraph, a higher number of recordings not needed (especially given the use of a the use of the terms (for the variance or for the estimate). Line 6 minimum of 5 recordings per station in the Cjlso*R analysis for PVNGS The basis for the selection of the min number is addressed in described in Appendix L)? Chap5 20. Section 7.2.1, Page Please define the term 'central value' (is it mean. median, or something The text was revised to replace "central" value will a more 7-2, First paragraph, else?). precise term Line 1 21. Section 7.2.1, Page Please cite appropriate references for ASK14, BSSA14, CB14 and Missing references were added 7-2, Paragraph 1, Line CY 14, as well as for the errata of the Akkar et al. (2014) and Bindi et al. 2-3 (2014) papers. 22. Section 7.2.1, Page Please explain whether there was an attempt to obtain the residuals or This was not done because applying a mixed effect would 7-2, Paragraph 1, Line databases, from which residuals could be calculated, for the Graizer require changing other parts of their model that affect the 4 (2014) and Idriss (2014) GMPEs in order that estimates of phi and tau median (and the authors judgments), thus requiring the could be derived before these models were rejected. authors to re-evaluate their model. The reason for not using these two models to estimate the standard deviations have been added to the Chao 7 text 23. Section 7.2.1, Page Please provide a reference to the section where plots of the magnitude The recommended cross referencing is added to the text 7-2, Paragraph 1, Line distribution of the Akkar et al. (2014) and Bindi el al. (2014) databases 5 are shown. 24. Section 7.2.1, Page Regarding the expression "it was assessed," please indicate who did the The text revised to clearly indicate that this is a Tl T earn 7-2, Paragraph 1, Line assessment (i.e., the Tl Team) in order to avoid confusion Please also evaluation. 9 ensure that similar references to the writers of the report are replaced with references to the Tl T earn throughout the report and appendices, unless someone else did the assessment, in which case they should be clearly identified. Moreover. use of the word "may" implies that it is not known and not assessed. If such an assessment was done, please delete the word "may" to indicate that the Tl T earn knows this to be the case. 25. Section 7.2.1, Page Some studies have developed separate sigma and median models. in The two models were not rejected for the median values. but 7-2, Paragraph 1, Line which case the model-specific sigma model of each GMPE is not they were rejected for the tau and phi values based on less 9 important. Please explain why the Akkar et al. (2014) and Bindi el al. reliable metadata. The point was clarified in the text. (2014) GMPEs were rejected on the basis of their sigma models and why the Tl T earn decided to use model-specific sigma models instead of a sigma model that is independent of the median model. 26. Section 7.22 1. Page Introducing the term "bump" is stylistically questionable (as The text was revised to refer to the narrow band increase in 7-2, Section title (and acknowledged by the use of quotes) and not as clear as simply calling the tau values at high frequencies. general comment on the feature a peak (which is unambiguously a feature with a local section) maximum). and leads lo inconsistency, as sometimes it is called a peak later in the report (e.g .. first line of next paragraph). Please consider whether a more conventional term such as "peak" (without quotes). used consistently in the subsection heading and thereafter, would be suitable here. 27. Section 7.2.2.1, Page Please explain why ASK14 and CY14 "chose to smooth through these Sections rewritten to better discuss the evaluations and the 7-2, Paragraph 1, Line variations" in the period-dependence of tau technical bases for the assessments 7 28. Section 7.22 1. Page Please provide a citable reference to the point-source simulation A reference to the approach used by Youngs was added. 7-3, Paragraph 1, Line methodology used by Bob Youngs. Because this work forms the 1 theoretical justification for removing the peak in tau around 10 Hz, please consider adding a more in-depth description of this work either to this section or as an appendix.

29. Section 7.2.2.1, Page Please explain why the particular values of median stress parameter (50 The results are not sensitive to these values. The text is 7-3, Paragraph 1, Line bars) and its logarithmic standard deviation (0.5) were selected and why revised to explain how the values were selected and the 2 the stress parameter is modeled with a lognormal distribution. Please sensitivity to the assumed values. also indicate whether the results are sensitive to the selection of these particular values. 30. Section 7.22 1. Page Please explain what logarithmic standard deviation is. The logarithmic standard deviation refers to the standard 7-3, Paragraph 1, Line deviation of the log values. The text is revised to make this 3 clear. 31. Section 7.22 1. Page Please ensure that the term "site kappa" has been defined in the report The term "site kappa" is replaced with" kappa at the 7-3, Paragraph 1, Line prior to its use in Chapter 7 and included in the list of terms. individual sites" 4 32. Section 7.2.2.1, Page Please explain why the particular values of median site kappa (0.035 See response to comment 29 7-3, Paragraph 1, Line sec) and its logarithmic standard deviation (0.3) were selected and why 5 site kappa is modeled with a lognormal distribution. Please also indicate whether the results are sensitive to the selection of these particular values. 33. Section 7.22 1. Page Please add text to explain what the "WUS amplification factor is and The text is revised to include a definition of the amplification 7-3, Paragraph 1, Line what effect it is supposed to model (also ensure that the acronym WUS factor as it is used in this simulation method 5 has been defined when it is first used and included in the list of acronvmsl. 34. Section 7.22 1. Page This sentence implies that the site amplification from the Boore and The frequency independence referred to the random 7-3, Paragraph 1, Line Joyner (1997) site profile is frequency independent; whereas, it is highly adjustment from the frequency depended site amplification 5-7 frequency dependent. Please clarify whether it is the site factor itself or factor. Text revised to make this clear the variability in this site factor that is frequency-independent. Please explain why the particular values for median site amplification variability (0) and its logarithmic standard deviation (0.4) were selected and why site amplification is modeled with a lognormal distribution. 35. Section 7.22 1. Page Please describe how you obtain the residual standard deviations from The simulated data are fit to a simple form using random 7-3, Paragraph 1, simulation data. effects. The text revised to explain the regression process Line 7 used to compute the phi and tau from the simulations 36. Section 7.2.2.1, Page Please also state that this methodology does not explain the "dip" in tau Text revised to discuss the dip at T=0.4 sec and that this is 7-3, Paragraph 1, at around T = 0.4 sec. not explained by the simulations Line 8 37. Section 7.2.2.1, Page Please describe the frequency-dependent site factor that was used. Text modified 7-3, Paragraph 1, Line 9 38. Section 7.2.2.1, Page Please consider providing a clear statement of what variable was Text modified 7-3, Paragraph 2, Line correlated with kappa, and how this correlation was determined. in the 1 2nd set of simulations 39. Section 7.2.2.1, Page Please consider whether the phrase "tau is a measure of the average The text was revised to clarify that tau is the standard 7-3, Paragraph 2, differences in ground motion from earthquake to earthquake" should be deviation of the event terms Line 4 more precisely formulated to reflect the fact that tau is a parameter that measures the dispersion of deviation (from average). 40. Section 7.2.2.1, Page Please revise this sentence to make ii clear that the total variance in The text was revised to explain the partitioning of the kappa 7-3, Paragraph 2, kappa is partitioned into two components: the event-to-event variation of variance Line 7 median site kappa of an event and the within-event variation of site kappa at 50 sites. 41. Section 7.22 1. Page Please clarify whether you mean "average" or "median". The term "average" is appropriate here. It does not depend 7-3, Paragraph 2, Line on median versus mean. 11

42. Section 7.2.2.2, Page Please rewrite paragraph for greater precision and clarity. The first two First sentence rewritten 7-4, Paragraph 1, sentences of this section read as though the previous section of the Lines 1and2 report was not there. Furthermore, they are imprecise. NGA-West2 analyses (not models) found the tau peak cited. The second sentence can be read as implying that the NGA-West2 studies attributed the peak to the kappa correlation, which they did not 43. Section 7.222. Page Please provide a reference to the section where the removal of the 10 A cross reference was added 7-4, Paragraph 1, Line Hz peak is discussed and the outcome presented 3 44. Section 7.2.2.2, Page Please further articulate this recommendation to include, for example, This is part of the site response -hazard inference Chapter. 7-4, Paragraph 1, Line how site response should be conducted in order to be consistent with the A reference to this interface added in the Chap 7 4 decision to remove the 10 Hz peak. 45. Section 7.23, Page Please use consistent language throughout the report and appendices to The text was revised to use consistent terminology for the 7-4, Paragraph 1, 2nd refer to the set of GMPEs selected for the tau study (currently they are set of selected GMPEs and 3rd Lines: called, e.g., "considered models," "five considered GMPEs," "the 5 GMPEs," "the underlying five models" elsewhere in Chapter 7). 46. Section 7.2.3, Page The cited figures, 7.2.3-2 and 7.2.3-3, are missing. Numbering has been fixed (it referred to the figures in the 7-4, second to last subsequent Section) line of section 47. Section 7.2.4, Page The word "significantly" represents a subjective judgment by the Tl sentence has been removed 7-5, Paragraph 2, 2nd Team. Please replace "significantly" with a more quantitative description Line of the change of tau with period and discuss why this change is not considered to be significant. 48. Section 7.2.5, Page On the right hand side, the subscript "w" is incorrectly included. Typo corrected 7-5, First Paragraph of section, Equation 7.2.5-1 49. Section 7.2.5, Page Please justify why the within-model variability of tau from CY14 can be This is addressed in the new appendix P (see general 7-5, 1st Paragraph of considered representative of the other four selected models. Also comment 6) Section, 2nd provide a citable reference to the result from Bob Youngs referred to Sentence here, if one is available. Otherwise provide documentation of that analysis and its results in the chapter or an appendix. 50. Section 7.2.5, Page The phrase "smoothed using a constant across all periods" is misleading sentence replaced 7-5, Paragraph 1 of if the intent was that the average over all periods was done to produce a section, 5th line after period-independent model. Please clarify. eqn 7 2 5-t 51. Section 7.25, Page The averaging process doesn't "account" for the slated fact, but rather sentence replaced 7-5, Paragraph 1, Line makes it irrelevant, since the Tl Team elected to use a period-6 after eqn 7.2.5-1 independent model. Please clarify this point. 52. Section 7.2.5, Page Please provide lexl to explain clearly why the distribution is "scaled, addressed in the new appendix P (see general comment 6) 7-5, Paragraph 2, Line how the scale factor c and degree of freedom k are derived (e.g., are 5 they set to obtain a simultaneous match to mean and variance of tau squared?). and why this distribution is appropriate for modeling the uncertainly in tau squared. 53. Section 7.25, Page Please describe what value of tau squared should be entered into the addressed in the new appendix P (see general comment 6) 7-5, Paragraph 2, equations for c and k. This special value of tau characterizing the Second 10 Last Line distribution should be given a distinct notation to differentiate ii from the random variable tau whose distribution is being characterized.

54. Section 7.2.5, Page Please provide additional justification and basis for the magnitude-The mag-dependent tau is based on the mean tau shown in 7-6, Paragraph 1, dependent tau model shown in Figure 7.2.5-5. Figure 7.2.3-1. A cross reference to this figure is added lo Sentence 3 this section of the text 55. Section 7.3 1, Page The hazard sensitivity studies from elsewhere in the report that support The deaggregations have been added to Chap 4 to indentify 7-6, Paragraph 1, the specific magnitude and distance ranges selected as "important" for the mag & dist ranges that are important to DCPP. A cross Lines 4-5 DCPP should be referenced here, with section and figure numbers cited. reference to these chap 4 plots is added to this section. Please also provide a more quantitative description of what is meant by "important", since this term represents a subjective judgment of the Tl Team. 56. Section 7.3 1, Page Please rewrite this sentence to clarify its meaning, and also provide a A Reference to the PEGASOS study is added. The text was 7-6, Paragraph 1, reference for the results cited from an external project. revised to explain why the PEGASOS models are not used Final sentence directly. 57. Section 7.3 1, Page Please add references to parts of the report where results of the Tl A cross reference to the Tl Team evaluations is added. A 7-6, Paragraph 2 Team's evaluations are presented (including a reference to a figure figure is added to the report to show that the phiSS values supporting the statement that "the calculated <i'ss values were consistent are similar among the 4 NGA-West2 models. among the 4 NGA-West2 models"). 58. Section 7.3.1, Page Please add precise references to the report and/or appendix section(s) Cross references to the new appendix P is added to this 7-6, Paragraph 3 of where the coefficient of variation estimate of 0.12 is derived (for section section, Line 4-7 example. "Appendix M, Section M 3 and Figure M.7"). where use of chi-squared distribution of <pss is explained and justified, and where the details of model derivation and assessment are available. The general catchall referral to Appendix M in the last sentence of the paragraph is insufficient in this regard. 59. Section 7.3.1, Page Regarding the statement that " ... values were smoothed over period: The smoothing is a fit to a bilinear model. An explanation of 7-7, Paragraph 2 on please clarify nature of smoothing or provide reference to section of how the smoothing is done is added to the text page, Line 1 report that does so. 60. Section 7.3.1, Page Please provide the justification and basis for the proposed high and low The high and low values are from the confidence bounds of 7-7, Last paragraph of values of q>ss and provide missing Table 7.3.1-3. the estimates. A cross reference to the new App P is added. section, last sentence The missing table is added 61. Section 7.3 1 1. Page Please add text to describe the findings regarding dependence on included as NEW appendix K 7-7, Paragraph 1, Line distance, style-of-faulting, and Vs30. Please also add text (here or in 1 Chapters 1tand12) to justify the Tl Team's decision to not model such dependence in the logic tree for sigma. 62. Section 7.3.1.1, Page A reference to Workshop 3 (Appendix G) is not sufficient. If this work See comment 61 7-7, Paragraph 1, Line was done outside the SWUS project, please provide references to 2 publications or peer-reviewed reports. If this work was done within the SWUS project, then please add more documentation or cite sections of the report where such documentation is included. 63. Section 7.3 1 1. Page Please also summarize where in Chapter 7 the models for <Pss and their The table with the results was missing. This table is added 7-7, Paragraph 2 coefficients can be found. (see comment 60) 64. Section 7.3 1 1. Page Please further justify the inclusion of the magnitude-independent (jlss Done -the M -independent CA model has been replaced by 7-7. Paragraph 2 branch (with the CA data set) in light of the clearly observed magnitude-a M dependent model with break at MS.5 dependence shown in Figure M.4. 65. Section 7.32, Page The part of the sentence after the comma that starts with "a subsets of We have removed "a subsets of' from the text 7-7, 1st Paragraph of the single-station seems to be disconnected from the first part of the Section, 2nd sentence. Please restructure this sentence to clarify its meaning. Sentence 66. Section 7.3.2, Page Please indicate that Figure 7.3.2-t shows <pss values for the European Entire sentence has been restructured 7-7, 2nd Paragraph of dataset, which is not obvious from the text. Section, 1st Sentence

67. Section 7.3.2, Page Please provide reference to specific section(s) or appendices of the A reference to the new appendix P which addresses this 7-8, 1*1 paragraph on report where this figure for COV(<pss) is derived. including explanation topic is added this the text page, Line 2-4 on and justification of the method based on chi-square distribution. page 68. Section 7.3.2, Page Please explain why data for only five spectral periods are shown in Only 5 periods are used because the Taiwan data available 7-8, 1 paragraph on Figure 7.3.2-2. to the project was limited to these five periods. The figure is page, Line 4 revised to also show the phiSS at other periods without the Taiwan data 69. Section 7.321. Page Please explain why the CA dataset was not used to develop a Addressed in Chapters 11 and t2. The logic trees show all 7-8, 1st Paragraph of magnitude-dependent <pss model for PVNGS as it was for DCPP. the branches. also associated to models not used (in this Section, 1st Sentence case zero weight). Same nodes are provided in the figures for DPP and PVNGS, but different weights are applied as appropriate 70. Section 7.3 3, Page Please provide further explanation and basis of the statement "No data The text is revised to explain the treatment of the CB 14 data. 7-8, 2nd Paragraph of in the distance range of 200 to 400 km is available in the CB14 dataset". The residuals are computed using the event terms provided Section, 1st Sentence CB 14 did use data from distances of 80-500 km to fit average anelastic by the developers. The CB14 model events terms are only attenuation terms, but did not include these data in the derivation of for the short distances. These event terms may not be event terms and within-event standard deviations. applicable to 200-400 km. Therefore. the CB14 residuals were not used for this step 71. Section 7.3.3, Page Please provide reference to specific section(s) or appendices of the A reference to the new appendix P which addresses this 7-8, 3rd Paragraph of report where this figure for COV(</lss) is derived, including explanation topic is added this the text Section, 2nd and justification of the method based on chi-square distribution. Sentence 72. Section 7.3.3, Page Please consider deferring any discussion of logic-tree weights and their The discussions on logic tree weights is removed from this 7-9 1st Paragraph, 1st justification until the report sections that present the logic-trees. Other chapter and placed into the appropriate logic tree chapter Line parts of Chapter 7 present the models and their uncertainty and not the assessment of logic-tree branch weights, which requires additional justification; so introduction of weights in this section appears somewhat inconsistent with the rest of the chapter. 73. Section 7.4.1, Page Please explain why all four NGA-West2 GMPEs can be used for the The PhiSP-R is estimated from the GMPEs and the AZ data 7-9 1st Paragraph of assessment of (jlsP-R. whereas CB 14 was excluded from the assessment (new residuals computed), whereas for the PHISS, the Section, 1st sentence of <Pss. within-event residuals provided by the developers are used. Because we compute the residuals for PhiSP-R, we can use all four of the models. The text is revised to explain this point. 74. Section 7.4 1, Page Please justify why only three spectral periods are sufficient to define the Due to the bandwidth of the oscillator. the change of PHISP-7-9 1st Paragraph of period-dependence of single-path term (/)sP-R. given that the observed R for nearby periods is small. From the hazard calculations Section, 2nd dependence of this standard deviation for other spectral periods might from previous studies (chap 4), the dist CNMEX sources Sentence deviate from that shown in Figure 7.4.1-1. contribute significantly to the hazard at T>1 sec. For this evaluation, we captured the range of periods using T=0.5. T=1. and T=2 sec. (Note, the T=0.2 sec point was removed in the figure as this is not important to hazard and does not help the understanding) 75. Section 7.4 1 . Page Please provide a discussion of why the 0.2 s result is unstable. The T=0.2 sec value is not needed and was removed 7-9, 1st Paragraph of Section, 3'" sentence 76. Section 7.4.1, Page Please provide justification for the use of a chi-square distribution and A reference to the new appendix P which addresses this 7-9 1st Paragraph of provide a reference to this distribution and the related equations. Please topic is added this the text Section, 4rd Sentence also provide a reference (Le., the section in Appendix M) for the selection of a COV of 0.17; the explanation in the 4th Sentence requires additional *ustification.

77. Section 7.4.1, Page The related materials provided in Appendix Lare little more than a The phi_sp-r model is an empirical derived standard 7-9, 1st Paragraph of repeat of these sentences. The required technical details and basis for deviation whose mathematical framework is described in Section, 4*h sentence the proposed models for 4>sP-R are lacking. Please provide sufficient section 7.4.1. We disagree that there in inadequate technical and remainder of documentation so report satisfies SSHAC Level 3's requirement of being bases for this approach. paragraph clear, transparent, and complete. Any references to the appendix should be specific with respect to sections, tables, figures. 78. Section 7.5, Page 7-In addition to presenting the comparison, please discuss the important Additional discussion of these plots and how they show that 9, Paragraph 1 findings and how they agree (or disagree) with the logic-tree models range of the models is added to the text proposed by the Tl T earn 79. Section 7.5, Page 7-Please supply a reference for the Hanford project magnitude-dependent The reference to the Hanford project is added 9, Paragraph 1. Line 8 <pss. 80. References, Page 7-Please update Abrahamson et al. (2014) with journal volume and pages. Reference was corrected 10, Item 3 81. References, Page 7-Please add reference for published erratum to Akkar et al. (2014) and Reference was corrected 10, Item 4 cite both original paper and erratum in text. 82. References. Page 7-Ang and Tang (2007) is not cited in text. Please remove from references Reference was removed 10, Item 7 unless a citation is added to text. If it is cited, please cite by page number, and also include publisher location in the reference section entry. 83. References. Page 7-Please include an additional reference to the published erratum to Bindi Reference was added 10. Item 9 et al. (2014) and cite both references in the text. 84. References, Page 7-Please update the Boore et al. (2014) and Campbell and Bozorgnia Reference was corrected 10, Items 11 and 12 (2014) references to include the specific journal volume and pages. 85. References. Page 7-Please update the Chiou and Youngs (2014) reference to include the Reference was corrected 10. Item 14 specific journal volume and pages. 86. References. Page 7 -Please provide the page numbers or paper number for the Graizer Reference was corrected 11. Item 1 (2013) reference. 87. References, Page 7 -Please update the Idriss (2014) reference to include the specific journal Reference was corrected 1 t, Item 2 volume and pages. 88. References, Page 7-Please list the publisher's name and location for the Rodriguez-Marek Reference was corrected 11 and Cotton (2011) reference. 89. Tables 7.3.1-1, 7.3.1-These three tables are missing Missing tables with the PhiSS models were added 2, and 7.3.1-3 90. Figures 7.2.3-2 and These figures are missing. Missing figures were added 7.2.3-3 91. Figure 7.3.2-3, Page Please indicate in the cap1ion which panel is PGA and which is 1 s PSA Figures were modified to use consistent terms for the PGA 7-33 (the panel headers do this, but the information needs to be clearer, especially as the header uses T0.000 while the caption refers to PGA) 92. Figure 7.5-5 Please replace "/"with "and" so that the term "hiss/PhisP*R" will not be Text was revised as recommend confused as being a ratio. Also note that the figure is mislabeled (as 7 5-6) 93. Figure 7.5-7 To maintain consistency, please describe the three Italian datasets We are discussing three Italian models and not datasets. A referred to as .. Italy, PhiSS t -Italy, PhiSS2 -ltaly-PhiSS3" in the text. description of the Italian PhiSS models is included in Chapter 5. Section 5 5 We modified caption to say "models" instead than "data sets" CHAPTER 10 Tau Model Logic Tree for Both DCPP and PVNGS 94. General The chapter is tersely written. often with insufficient background The text was mildly expanded to make this chapter more self infonnation provided. and insufficiently thorough documentation of the contained and complete. logic tree and the assessment and evaluation that went into determining its branches and weights. Please ensure that the chapter is self-contained, with an adequate summary that references back to Chapter 7 (sigma overview chapter), and other chapters and appendices as needed. 95. Section 10.0 This paragraph has little substance. Please consider providing a done somewhat more complete outline of the chapter. 96. Section 10.1, Page Please point out the meaning of red versus green coding of the weights Figure caption is modified to explain the colors. This has 10-1, Paragraph 1. in Figure 10-1 (and in the caption of that figure) been explained in the text in the chapters on the median Line 2 logic tree so it is not needed again in the text of chap 10 97. Section 10.1, Page Please list or provide a reference to the parameter values of the scaled A reference to the new appendix P which addresses this 10-1, Paragraph t. Chi-square distribution that were used to compute the quantiles. Also, topic is added in the text. Mean value is the correct word Line 2 please confirm that it is the mean, not the 50th percentile, that was used for the central branch. 98. Section 10.2, Page Please consider replacing "observations" with "assessment" to indicate Text is revised as recommended 10-1, 1st Paragraph of that at this stage of the evaluation and integration that the Tl Team has Section, 2nd Line made its assessments of the proposed model. 99. Section 10.2, Page Please reference the appropriate sections of the chapter or appendix Initial hazard sensitivities are added to chapter 4. A cross 10-1, Item No. 1 where the hazard sensitivity analysis is presented that justifies the reference is added to the text in this section. specified magnitude and distances ranges of interest. 100. Section 10.2, Page Please also cite the published errata to Akkar et al. (2014) and Bindi et fixed 10-1, Item No. 2, 1st al. (2014) and include these errata in the list of references. Line 101. Section 10.2, Page The statement that The Zhao et al. (2006) magnitude-independent This statement is moved to later in the text where it fits into 10-1, Item No. 2, Last proponent model is judged to be applicable because their database is the modeling of the tau Sentence almost entirely composed of recordings from earthquakes with M 5" could be understood to be a counter argument to the adoption of a weight of 1.0 for the magnitude-dependent tau model mentioned in the beginning of this section. Please explain how the magnitude-independent tau model of Zhao et al. (2006) was incorporated into the magnitude-dependent tau model or remove this statement and discuss it later in the text 102. Section 10.2, Page Please either provide the full references to the acronyms BSSA 14, These acronyms have been defined in earlier chapters and 10-1, Item No. 3, 3rd CB14, CY14, and ASK14 the firsttime they are mentioned in Chapter 10 are also given in the list of acronyms and abbreviations. We and 4th Lines or ensure that they are defined the first lime they are mentioned in the do not see the need to define them in each chapter. report and that they are included in the list of acronyms. 103. Section 10.2, Page Please explain why it is proper to use the word "proponent" in this We deleted the word "proponent", because it is a model we 10-2, Paragraph t. sentence. derive. Proponent should be used for published models. We Line 4 will use the term "Tl-Team models for models developed by the Tl Team or under the direction of the Tl Team. 104. Section 10.3, Page Please avoid using the word "assuming" in this context, but rather We changed the word "assuming" to "using" 10-2, 1st Paragraph of replace it with a phrase that indicates that the logic-tree branches were Section, 1st Line developed by evaluating and assessing available data and results, referencing other sections of the report for supporting analysis if appropriate.

105. Section 10.3, Page Please provide a reference to sections/pages in Chapter 7 where the A reference to the new appendix P which addresses this 10-2, Sentence 2 evaluation of 0,2 is described. topic is added this the text 106. Section 10.3, Page Please either provide a reference that supports the specified A reference to the new Appendix P which addresses this 10-2, Sentence 2 approximation of a three-point discretization of a chi-square distribution, topic is added this the text including the specified weights, or explain the evaluation and basis for this approximation. 107. Section 10.3, Page In light of the discussions in Section 13.2, please clarify if the central, The logic trees for tau are not used directly in the hazard 10-2, general low, and high 1 branches described in this section are directly used in calculation. Rather, they are inputs to the simplified total comment on section the Hazard Input. lfnot, please explain the reasons for having this sigma models. The text is revised to make this clear. section. 108. Section 10.4, A large number of references contained in this section are not cited by fixed References this chapter. Please clean up the reference list 109. Figure 10-1. Page 10-Please add an explanation of the color scheme for the branch weights. Figure caption is modified to explain the colors. 4 110. Figure 10-2, Page 10-Please modify Figure 10-2 to show the final magnitude-dependent tau We believe it is valuable to see the underlying models and 5 model without all of the various models that were used to derive it and show that our range is broader than the range of the explain that this model is independent of frequency (the figure. being for proponent models, but this should be in Chap 7. We have T = 1 sec, implies that the model might be frequency-dependent). The swapped figure 7.2.5-5 (which just shows the final three other models shown in this figure were evaluated in a previous chapter models) with Figure 10-2. and need not be included in the final logic-tree model. CHAPTER 11 Phi Model Logic Tree: DCPP 111. Title Please add a subscript 'SS' to 'PHI' Text is revised as recommended 112. General The chapter is tersely written. often with insufficient background The text is expanded to make this chapter more self information provided. and insufficiently thorough documentation of the contained and complete. logic tree and the assessment and evaluation that went into determining its branches and weights. Please ensure that the chapter is self-contained, with an adequate summary that references back to Chapter 7 (sigma overview chapter), and other chapters and appendices as needed. 113. Section 11.1, Page Although the analysis of the aleatory variability is performed on the This is not the distribution of PHiSS. We are changing the 11-1, 2nd Paragraph within-event residuals, the distribution is on Phiss. Please remove form of the pdf of the residuals to allow for heavy tails. It is of Section, 5th "residual" to indicate that the distribution is for Phiss. not a change in the value of PhiSS. So it is not on the Sentence distribution of the phi SS but rather on the distribution of the residuals. See sketch below. /t;.) )hi SS -pdf x ows 114. Section 11.1, Page Please clarify if the phrase involving aleatory variability" is consistent The header in the figure was changed so to substitute 1 t-1, Paragraph 2. with the 'Epistemic Uncertainly' branch heading on Figure 11-1. "epistemic uncertainty" with "PhiSS estimate". Similar Line 6 changes were applied to figures 12-1 and 12-2 115. Section 11.2, Page Please provide references for the acronyms ASK 14. BSSA 14, CB 14. See response to comment 102 11-1, 1st Paragraph of and CY14 the first time they are mentioned in Chapter 11 or ensure that Section, 3rd Line they are defined the first time they are mentioned in the report and in nf 116. Section 11.3, Page Please further justify the assignment of equal (0.5) weight to the We have modified the CA models so that there are two M-11-2, Paragraph 1. magnitude-independent branch even though Figure M.4 suggests a clear dependent branches with break at M5.5 and M7. The text is Line 2 magnitude dependence in the California subset. Appendix references revised and additional justification is provided. should be specific, citing sections, pages, tables, and/or figures. 117. Section 11.3, Page Please provide a clear reference to where in Appendix M the absence of Appendix Mis incorporated into Chap 7. A cross reference 11-2, Paragraph 2. M-independence in the global dataset is illustrated. to the figure showing absence of mag dependence in the Line 1-2 global dataset (in chap 7) is added. 118. Section 11.4, Page This explanation is pretty cryptic until one studies Appendix M. Please The suggested change in wording is applied 11-2, Paragraph 2, consider whether clarity would be improved by an explicit statement that Sentences 1 and 2 the sampling distribution of (jlss at each site adds an upward bias on top of the true site-to-site variability of (jlss. Also consider whether the second sentence would be more precisely rendered if "removed 1he bias using" were replaced by "the bias was estimated assuming a chi-squared sampling distribution of (jlss 2 ",with reference to the place in the report where this assumption is justified. 119. Section 11.4, Page Coefficient of variation is abbreviated as CV here, but COV elsewhere. CV is used throughout the report. Changes have not been 11-2, Paragraph 2, Please make the notation consistent throughout the report. marked because occurred in several instances Sentences 3 and 4 120. Section 11.4, Page The assessment of the low and higher values of <Psss was not well A reference to the new Appendix P which addresses this 11-2, 2nd Paragraph documented in Appendix Mand in Chapter 7 (see previous comments). topic is added this the text of Section, Last Therefore, the statement that high and low epistemic uncertainty Sentence branches are computed corresponding to the 5th and 95th percentile of <Pss.s" does not have a well-documented basis at this point in the report. Also, the use of present tense infers that the calculations are discussed and included in Chapter 11 rather than in a previous chapter. Please revise Appendix M and Chapter 7 to fully support the assessment that the high and low values of <Pss.s can be represented as the 5th and 95th percentiles of the epistemic distribution. 121. Section 11.4, Page Please provide the mathematical basis for characterizing the central, 5th, Refer to the new Appendix P. We define the central estimate 11-2, 3rd Paragraph and 95th percentile values with weights of 0.6, 0.2, and 0.2, respectively. as the median. of Section Please also be more specific when referring to the "central" value as being the median. mean. or another statistical value of the distribution 122. Section 1.5, Page 11-Please provide a reference to the section (and pages, tables, and/or The directivity adjustment affects both the median and the 3, Paragraph 1, Line 2 figures, if appropriate) where directivity adjustment of <i'ss is discussed. aleatory terms. Both adjustments are described in Section 6.5 and shown in the figures herein We referenced back to that section. 123. Section 11.6, Page Please provide a brief description and reference of the "quantile plot (Q-A reference to a statistics text book is added to define Q-Q 11-3, 1st Paragraph of Q plot)" for clarity. plots, and we also added a short description of Q-0 plots Section, 3rd Line 124. Section 11.6, Page Please define what epsilon is the first time it is mentioned in Chapter 11, A definition of epsilon is added to the text 11-3, Paragraph 1. or ensure that it is defined the first time it is mentioned in the report and Line 4 that it is included in the list of terms. 125. Section 11.6, Page Because the concept of a mixture model is relatively new, all available We are now showing our own results 11-3, 2nd Paragraph sets of GMPE within-event residuals should be used to demonstrate that of Section, 1st the single mixture model proposed by the Tl Team can be used to Sentence characterize all of them. Please provide the analysis of residuals that was performed for ASK14 for the other three NGA-West2 GMPEs and demonstrate that the proposed normal distribution and mixture model is appropriate for all four GMPEs 126. Section 11.6, Page Please describe the "statistical tests" that were performed and provide a The statistical tests are test of the observed 0-Q plot being 11-3, 2nd Paragraph reference for these tests. above the 1-to-1 line for a given confidence level. Add of Section, 2nd Line explanation of confidence bounds in the figures. In addition. Anderson-Darling tests were applied and the reference is cited 127. Section 11.6, Page Please clarify who conducted the tests on KiK-net data. If it was outside The tests on Kik-net data were conducted under the Hanford 11-3, Paragraph 2, the SWUS project, please provide a reference. If it was within the SWUS PSHA project. However, now we are showing our own Line 6 project, please give more technical material so there is sufficient results and we do not need to reference Hanford anymore technical basis to support the conclusions derived from the KiK-net data. 128. Section 11.6, Page Please rewrite this paragraph to give a more rigorous presentation of The text is modified to expand the description of the mixture 11-3, Paragraph 3 mixture model, including appropriate references. The phrase "a sum of model. multiple normal distribution" could easily be misunderstood by those who are not familiar with the concept of mixture model 129. Section 11.6, Page Please describe the technical evaluations that lead to the selection of The sum of the two normal distributions was assessed using 11-3, Paragraph 3. mixture of two normal distributions with equal mean. a statistical package designed to identify mixtures in data. Line 3 The selected mixture was checked using Q-0 plots of the ASK 14 data and found to produce results consistent with distribution of the data. Text is expanded to explain this point 130. Section 11.6, Page Please describe the technical evaluations/calibrations that lead to the See response to comment 129 11-4, Paragraph 2. (0.5, 0.5) mixture weight and the (1.2, 0.8) scale factors, and that justify Line 4 the application of the model to all of relevant GMPEs (even though the model was calibrated using ASK14 residuals). Were parameters obtained by trial and error or by methods of statistical inference? 131. Section 11.6, Page Note also that the parenthetical epsilon range should be written with a Text was modified as recommended 11-4, Paragraph 2. minus sign, i.e."(<= -3)" Sentence 6 132. Section 11.6, Page The upper case phi in this equation appears to be the cumulative Correct, we defined the notation for the GDF 11-4, Equation 11-2 distribution function. Please check that the notation has been introduced and defined prior to its use at this point. 133. Section 11.6, Page Please explain what a composite normal distribution is. The word "composite" is deleted. 11-4, Paragraph 4, Line 1 134. Section 11.6, Page Please provide the technical justification for allowing a normal The mixture model is new and. while we strongly favor it, we 11-4, Paragraph 4. distribution with non-zero weight. given that you report that your analysis maintain the traditional normal distribution with small weight. Line 2 consistently showed heavy tails. 135. References

• General Please remove those references that are not cited in the text. References were removed comment 136. References, Page 11-Please update the Dawood et al. (2014) reference to include the volume Reference was corrected 5, Item 2 and page numbers of the published version, if available. 137. Figure 11-1, Page 11-Caption should explain the meaning of the color scheme used for the Figure caption is modified to explain the colors 6 weights 138. Figure 11-2, Page 11-Please explain what "Studentized Residual" is in the y-axis label, and Studentized residual is a normalized residual. This plot is 7 correct the caption by replacing "T=2 sec" with "T=0.5 sec" part of the build-in statistic package used in the analyses. We have now inserted more QQ figures 139. Figure 11-3, Page 11-Please replace "ASK" with "ASK14" in the caption Text was modified as recommended .!!

CHAPTER 12 Phi Model Logic Tree: PVNGS 140. General The chapter is tersely written. often with insufficient background The text was expanded to make this chapter more self information provided. and insufficiently thorough documentation of the contained and complete. logic tree and the assessment and evaluation that went into determining its branches and weights. Please ensure that the chapter is self-contained, with an adequate summary that references back to Chapter 7 (sigma overview chapter), and other chapters and appendices as needed. 141. Section 12, Page 12-Please replace "I" with "and" here and elsewhere in Chapter 12 to avoid Text was modified as recommended 1, 1st Paragraph, 1st confusion that the term "<pss I q>sr-R." refers to a ratio. Line 142. Page 12-1, Paragraph Please clarify whether the first motivation implies there is a significant No. this does not imply a significant dependence on mag, 1, Line 5 dependence on magnitude, distance, and style of faulting. dist, or SOF. Paragraph is rewritten to clarify the question. More figures provided in a NEW Appendix K 143. Section 12.1.1, Page Please remove "residual" to clarify that the aleatory distribution is for q>ss. The statement is correct. This is a distribution of residual and 12-1, 2nd Paragraph not the value of phiSS of Section, 4th Line 144. Section 12.1.1, Page Please consider moving this sentence to the beginning of this section. Done 12-1, Paragraph 2. Lines 4 to 6 145. Section 12.1.2, Page Please provide a reference to the section where the necessity to use The need for both data sets is discussed in Chapter 7. A 12-1, Paragraph t. both datasets is discussed. cross reference is added to the text Sentence 1. Line 1 146. Section 12.1.2, Page Please also reference the published erratum to Akkar et al. (2014 ), in fixed 12-1, 1st Paragraph of which case the reference becomes Akkar et al (2014a,b). Section, 2nd Line 147. Section 12.1.2, Page Please specify the magnitude and distance range. Also, please confirm The mag-dist range (M >=5, R <=50 km) is added to the text. 12-2, Paragraph 1. that the developers mentioned in this sentence are the NGA GMPE The "developers" are the NGA developers. The text is Lines 4 and 5 developers. modified to make this clear 148. Section 12.1.2, Page Please consider summarizing these data statistics in a table. Also, This text is repetitive and is moved in Chapter 7 which 12-2, Paragraph. 1 please clarify if these statistics are based on a data subset in which includes these tables. Lines 3to 9 each station recorded at least 3 earthquakes. 149. Section 12.1.2, Page Please provide a reference to the sensitivity analyses that show that Initial hazard sensitivities are added to chapter 4. A cross 12-2, 2nd Paragraph, large (M > 6) magnitudes are important for the hazard calculations at reference is added to the text in this section, (reference to 2nd Line PVNGS the deaggregation from previous studies) 150. Section 12.1.2, Page Only one limitation of the European dataset is listed as justification for Yes, all of the limitations were considered. 12-2, 3rd Paragraph the smaller weight given to the European dataset; whereas, several limitations are mentioned in the previous paragraph. Please clarify whether these other limitations contributed lo the Tl Team's assessment to give the European dataset less weight. 151. Section 12.1.4, Page Please justify the use of weights of 0.2, 0.6, and 0.2 to define the A reference to the new Appendix P which addresses this 12-2, 1st Paragraph of central, 5th, and 95th percentiles of the epistemic distribution of q>55. topic is added this the text Section, 2nd Please also be specific whether the central value represents the mean Sentence or median. 152. Section 12.2.1, Page The phrase "are added to" could be misleading (suggesting We removed the word "added" and slated that is used to 12-3, 2nd Paragraph mathematical addition of unspecified quantities), so please consider modify the GMPE of Section, 3rd Line using another wording. 153. Section 12.2.1, Page Please remove "residual" to clarify that the aleatory distribution is for See response to comment 143 12-3, 3rd Paragraph IPss. of Section, 4th Line 154. Section 12.2.2, Page Please summarize why a single dataset is appropriate for each branch We only have one set of Arizona data for the path term 12-3, 1st Paragraph of of the logic tree. branch. For the no-path term branch, the California model is Section, 4th Line not used because the site is not in California and the global model is judged to be more appropriate. This discussion and basis is added in the text. 155. Section 12.2.3, Page Please provide a reference to specific sections, pages, tables, and/or Appendix N is incorporated in the main report. Cross 12-4, 1st Paragraph of figures to Appendix N. references is provided Section, 1st Line 156. Section 12.2.4, Page Please provide the basis for the increased CV (i.e., COV) from 0.14 to The difference occurs because the CV for the Arizona data 12-4, Paragraph 1. 0. 17 (and please ensure that terminology for coefficient of variation is set is higher. The terminology is made consistent to use CV. Line 2 consistent throughout the report and appendices). 157. Section 12.2.4, Page Please justify using weights of 0.2, 0.6, and 0.2 to represent the 5th, A reference to the new Appendix P which addresses this 12-4, 1st Paragraph of central, and 95th percentiles of the epistemic distribution of the Phi topic is added this the text Section, Last terms. Please also be specific whether the central value represents the Sentence mean or median. 158. Section 12.2.5, Page Please clarify who made the judgment and describe the basis for the This is a Tl Team judgment and text was modified to make 12-4, Paragraph 1. judgment. this clear Line 3: 159. Section 12.2.5, Page Please provide the technical justification for allowing a normal see response to comment 134 12-4, Paragraph 1. distribution with non-zero weight. given that your analysis consistently Line 4 showed heavy tails. 160. Section 12.3, Page Please revise the date to "2014a" to reflect the published manuscript and fixed 12-4, 1st Item the fact that the erratum was published in the same year. 161. Section 12.3, Page Please update Akkar et al. (2014) to Akkar et al. (2014b) and provide the fixed 12-4, Item 2 volume and page numbers of the published erratum. 162. Section 12.3, Page Please remove the Abrahamson et al. (2014) reference or cite ii in the fixed 12-4, Item 3 text. 163. Figure 12-2 Figure is incorrectly numbered ("Figure 1") Figure label for fig 12-2 was corrected CHAPTER 13 Total Sigma Model 164. The chapter is tersely written, often with insufficient background The text is expanded to make this chapter more self information provided, and insufficiently thorough documentation of the contained and complete. logic tree and the assessment and evaluation that went into determining its branches and weights. Please ensure that the chapter is self-contained, with an adequate summary that references back to Chapter 7 (sigma overview chapter), and other chapters and appendices as needed. 165. Section 13.1 Please provide an overview of the methodology used in other recent An overview is added to the text SSHAC Level 3 PSHA studies to construct total sigma models. 166. Section 13. 1 This methodology can significantly benefit from an extensive rewrite Sections is rewritten to better explain how the total sigma (including related parts in Chapters 7, 10, 11, and 12) to improve model is a more efficient version of the combination of the readability and understandability. Please provide a clear and easy-to-separate phi and tau models understand presentation of the basic principles and ideas behind the methodology, which should also serve to connect the various pieces presented across Chapters 7. 10, 11, 12, and 13. 167. Section 13.1, Page Please verify and, if found incorrect, provide the proper references The text is modified to refer to the logic tree branches in 13-1, Paragraph 1. where logic-tree branches are presented. Chap 10, 11, and 12. Line 1 168. Section 13.1, Page Please check whether this report section actually applies the Miller and The new Appendix P addresses this topic. We are using the 13-1, Paragraph 1. Rice (1983) methodology. Otherwise the reference to that paper here is 5th. 50th, and 95th fractiles as the three point distribution. Line 2 misleading and should be dropped. Consider whether Keefer and Bodily Also, the Miller and Rice reference was not correct and was is an appropriate reference for the type of distribution resampling applied removed here. 169. Section 13.1, Page The reference to the book by Ang and Tang (2007) is too general. The new Appendix P addresses this topic. The specific 13-1, Paragraph 1. Please confirm that this reference is the appropriate one for the discrete sections of Ang and Tang (2007) is cited in the appendix Line 3 representation of scaled Chi-squared distributions, and if so, please cite page number(s). 170. Section 13.2, Page Theo here appears to be the same as Oss in Eq 5.4.1-1 on page 6-20 The text is modified to indicate the fact that the type of total 13-1, Paragraph 1. (October 2014 draft), and in Section 13.4, second to last line on page sigma depends on the type of phi Lines 5-6 and Eq. 13-13-3. If that is correct, please replace cr with crss throughout the chapter 1 for consistency with terminology used elsewhere in the report. 171. Section 13.2, Page Please discuss or reference the "resul1s" being referred to in the The results are from the NGA-West2 regression studies. but 13-1, 1st Paragraph of statement "results that show a very weak negative correlation between ' these were not published. We will add the correlations from Section, 10th Line and cp". the ASK14 and CY14 studies to show the size of the correlation. 172. Section 13.2, Page Section 7.3.1 does not provide the definitions of the scaled chi-squared A reference to the new appendix P which addresses this 13-2, Paragraph 1. distribution as claimed. Please provide a correct reference. topic is added this the text Line 1: 173. Section 13.2, Page The first equality is nawed: no non-constan1 function of xis equal to the The equation is correct. As sigma is always non negative. 13-2, Paragraph 1. same function of x2. This abuse of notation is confusing. If it is necessary there is a monotonic one-to-one relationship between o and Equation 13-3 to introduce the first equality, please clarify its meaning. o2. As a result the probability that a is less than or equal to x is equal to the probability that a2 is less than or equal to x2 for all non negative x 174. Section 13.2, Page In equation 13-4, c is defined as a function of sigma-squared, treated as This is described in the new appendix P 13-2, Paragraph 1. a deterministic variable, but sigma is a random variable in Equation 13-3. Equations 13-4, 13-5. The same applies to the definition of constant k in Equation 13-5. The substitution of Equations 13-4 and 13-5 into 13-3 leads to incomprehensible results. Please define and use notation that clearly distinguishes between the random variable and the deterministic variable 1hat represents a distribution model parameter. This should be done in a manner that maintains consistency with the rest of the report notation. 175. Section 13.2, Page Please indicate what typical numerical values of c and k are. This is described in the new appendix P 13-2, Paragraph 1. following Eqn 13-5 176. Section 13.2, Page Please provide an explanation of what a "weighted composite CDF" is The term "weighted composite CDF" refers to the 13-2, Paragraph 2, and how it was computed. Also, please confirm that the composite CDF combination of the phi and tau (composite) using the weights Lines 5-6 is for (j)ss only (as indicated in the legend of Figure 13-4). Finally. please from the phi and tau logic trees. Fig 13-4 is for the total, not explain why composite CDF for <Pss is created and presented in this only for PhiSS. The legend shows the PhiSS part with the chapter, not in Chapters t 1. 12. Also note that the sentence beginning same tau models added in each case. Text revised and on line 5 ("Using weights ... ) is garbled-please revise to clarify its augmented to provide additional details explaining how the meaning. models were derived. Garbled sentence rewritten. 177. Section 13.2, Page Please add text to explain how the weigh1ed composi1e CDF for 4>ss was See response to comment 176 13-2, Paragraph 2, used to form the composite distribution of total sigma given in Table 13-Line 5-7 1. 178. Section 13.2, Page Please provide a reference for the statement made in this sentence. If it A Table has been added to support the statement. More 13-2, Paragraph 2, is based on SWUS's own investigation, then please include, at a verbiage provided Sentence 6 minimum, a supporting figure for this conclusion. 179. Section 13.2, Page Please confirm that variance, not standard error, was the quantity that The fractiles are developed on variance; we simply take the 13-2, Paragraph 1. was used in the analysis throughout this report. Also. please explain square root of the sample point for the standard deviation Last Line (Eq. 13-6) how you go from a model of variance to a model (Eq. 13-6) of standard The fractiles are not affected by the square root operation. deviation. Text was modified to explain this. 180. Section 13.2, Page Also please reference where in the report the basis for Equation 13-6 In the text. we will note that a bilinear model was used based 13-2, Paragraph 1. can be found. on the bilinear model for PhiSS. Last Line (Eq. 13-6) 181. Section 13.3, Page Please briefly summarize the three uncertainty models being referred to The three models are the PHISS models for greater AZ 13-2, 1st Paragraph of in this sentence. and clarify that the models for PVNGS are (or <Pss-r) sources, the PHISS for the CNMEX sources, ad the PHISP-Section models (as opposed R for the CNMEX sources. The text is revised to make this clear 182. Section 13.3.1, Page Please add text to discuss the need for two alternative models. The need for the two alternative models is that there are two 13-3, Paragraph 1. branches in the logic tree for data sets in Chapter 12. We will Line 2 revise the text to reference back to Chapter 12. The total sigma model is just a parameterization of the tau and phi models from Chapters 10 and 12. 183. Section 13.3.1, Page In addition to Table 13-2, please also provide a figure similar to Figure The requested figure is added. 13-3, 1st Paragraph of 13.4 to show how well the composite distribution fits the original Section, Last distribution. Sentence 184. Section 13.3.2, Page In addition to Tables 13-3 and 13-4, please also provide a figure similar The figures are not needed because there is only one phi 13-3, 1st Paragraph of to Figure 13.4 to show how well the com po site distribution fits the model being used Section, Last original distribution. Sentence 185. Section 13.4, Page Please provide a reference (such as Jayaram and Baker, 2010) for the We added "They found that" at the beginning of the second 13-3, 1st Paragraph of statement "it leads to an increase in the .p estimates and decrease in the sentence. Section, 3rd Line t estimates". or provide another basis for this statement. 186. Section 13.4, Page According to Appendix R, the analysis was done on the model of CY14 The text is modified to make this consistent with the current 13-3, 1st Paragraph of (Chiou and Youngs, 2014). Please remove "preliminary" and revise the Attachment D Section, 5th Line date from "2013" to "2014" in the statement "preliminary CY14 (Chiou and Youngs, 2013)" to conform to the discussion in Appendix R. 187. Section 13.4, Page Please change the reference to Shahi (2014), here and at other The work by Shahi and Colleagues is packaged as a "Report 13-3, Paragraph 1. locations. to reflect the multiple authors of Appendix R. Also, please use to GeoPentech for the SWUS GMC Study", and properly Line 5 some alternative style for the citation, as the author/year form of citation referenced in the Reference. It is documented in the report is only appropriate for an article or report that appears in the reference as an Attachment (thus not as an Appendix anymore) list, not for an internal reference to an appendix, which is an integral part of the report. 188. Section 13.4, Page Please clarify what the terms "homoscedastic" and "heteroscedastic" Homoscedastic refers to the magnitude-independent model 13-3, 1st Paragraph of refer to in this context. and heteroscedastic refers to the magnitude-dependent Section, 6th and 7th models. Clarifying text is added. Lines 189. Section 13.4, Page Please clarify who conducted the semivariogram analysis (was it the Tl This analysis was done by Linda under the direction of the Tl 13-3, Paragraph 1. Team or Shahi et al., Appendix R). and provide a reference that Team. Proper reference is provided. Line 9 describes the semivariogram analysis methodogy. 190. Section 13.4, Page Please explain what normalization factor was used for the normalized The variogram is normalized by the variance of selected 13-3, Paragraph 1. variogram. Please also change the figure caption and the y-axis label of subset of the data. This is explained in the text Line 12 Figure 13-6 to reflect the use of normalized variogram. 191. Section 13.4, Page Please specify the amount of reduction in tau that was used to obtain the The reduction in tau is ranges from 0 to 7% (see Figure 13-5. 13-3, Paragraph 1. 4% increase in total sigma. This is added to the text. Thi rd to Last Line 192. Section 13.4, Page Please justify why it is appropriate to change the weights for all spectral The results from 2010 and 2014 show very different period 13-4, 1st Paragraph, periods when the analyses of Jayaram and Baker (2010) and Appendix dependence. This is a small effect and we choose to model it 3rd Sentence R indicate that they are period-dependent. Please also explain how what as a constant to all periods. The average of the 2010 and appears to be a relatively large degree of epistemic uncertainly 2014 models is close lo be period-independent. Clarifying depending on the dataset that is used to perform the analyses is taken text is added. into account. when results are available for only two datasets. 193. Section 13.4, Page Please discuss whether the modified weights (which constitute a skewed No. we are not capturing the true shape but this is a 13-4, Paragraph 1. discrete distribution) adequately capture the true shape of the sigma relatively new work with inconsistent results between 2010 Last Sentence distribution that accounts for spatial correlation in residuals. Please also and 2014. So we are using a simpler approach by discuss if the 3-4% increase in mean sigma is justified and if the introducing skewed weights on the branches from the variance of total sigma is unaffected by the consideration of spatial standard approach (i.e. ignoring the spatial correlation correlation in residuals. effect). We think this a reasonable approach at this state of development of the analysis. Text is modified lo explain this justification. 194. Section 13.5, Page In previous discussions of these distributions, they were described as Inconsistent terminology is cleaned up 13-4, 1st Paragraph of normal and a mixture of normal without "log" in front of them. It was Section, 1st Sentence relatively clear that this was because the distributions were developed from the within-event residuals, which have natural log units. The use of "log" now can be confusing given these previous discussions. Please explain why "log" is now being used to describe these normal distributions for additional clarity or remove "log" and describe that the distribution is on a parameter that has units of natural log. 195. Section 13.5, Page Since not cl>. was used in Eq 13-1, please justify the decision to apply Justification is provided 13-4, Paragraph 1. the same factors and weights for .p lo .Pss. Line 4 196. Section 13.5, Page Please replace "event-to-event" with "between-event" to be consistent The term is changed, and consistent terminology is used. 13-4, 1st Paragraph of with terminology used elsewhere in lhe report. Section, 6th Line 197. Section 13.5, Page Since <Pss. was used in Eq. 13-1, please rewrite this sentence in The term is changed, and consistent terminology is used. 13-4, Last Sentence terms of 198. Section 13.6, Page Please update the Abrahamson et al. (2014) reference to include the fixed 13-4, Item 1 page numbers of the published manuscript. 199. Section 13.6, Page Please provide the location of publisherfor the Ang and Tang (2007) fixed 13-4, Item 2 reference. 200. Section 13.6, Page The date is incorrect. This report is actually Chiou and Youngs, 2013. fixed 13-4, fourth entry But please remove it from references, since the citation in Appendix R is actually of the published paper, Chiou and Youngs (2014) 201. Section 13.6, Page Please update the Chiou and Youngs (2014) reference lo include the Reference was updated 13-5, Item 1 page numbers of the published manuscript. 202. Section 13.6, Page As noted in an earlier comment, it is questionable whether this article Reference was checked and text was updated as applicable 13-5, Last item was correctly cited. If the citation is deleted, please also delete this reference section entry and replace with the correct reference. 203. Table 13-4, Page 13-Sigma listed in other tables show an increasing trend with period. Please The observation is correct. For the large distance data set 9 provide explanation for the decreasing trend shown in this table. Also, at (200-400 km). the standard deviation decreases with period. T>= 5 sec, the central branch in Table 13-3 is higher than the central The other comparisons were for shorter distances. There are branch in Table 13-4. Please clarify whether <lisP-R is supposed to be no inconsistencies between these two sets of results. On always lower than <liss for all periods (because of the removal of average, PhiSP-R is lower than PhiSS for large numbers of systematic path effect) and whether the above-mentioned reversal is data set However, for an individual path. PhiSP-R may be expected. larger ifthe crustal structure is more variable than average. This was explained in the text. 204. Figure 13-6, Page 13-Please note that the legends are erroneous in both the upper and lower Legend is corrected 6 panels: the exponential functions are incorrectly identified with the blue asterisk symbols instead of with the red curves. 205. Figure 13-7. Page 13-The caption refers lo preliminary CY14 model and cites Chiou and See response to comment 200 14 Youngs (2013). But Appendix R says that the Shahi et al. analysis is for the published work, not the preliminary model, and cites the published paper Chiou and Youngs (2014). Please correct. and use an appropriate reference to Appendix R rather than the author/date citation of Shahi APPENDIX L Path Terms for PVNG and Associated Phi _sp-r Model 206. Section L.1, Page L-1, 1st Please explain why path-specific effects are used and why they are Appendix is absorbed into the report (Chapter 7). Text is Paragraph, 1st Sentence appropriate for modeling the ground motion from California and Mexico added to Chapter 7. See also response to comment 1 t earthquakes. It would also be helpful to clarify in this introductory paragraph that .PsP-R is an alternative model to <liss for representing site-specific within-event standard deviation (that they are mutually exclusive alternative models for PVNGS). 207. Section L.1, Page L-1, Line The notation <lisP-R is used here without introduction. Please ensure that Because Appendix N is absorbed into Chapter 7, the term is 3 notation is defined at the time it is introduced. introduced the first time it is used in the chapter 208. Section L.2, Page L-1, 1st Please reference the specific dataset(s) from Chapter 5, and explain why Specific data set is referenced. The deaggregation shows paragraph of section only four spectral periods are available and why these four periods are that the contribution to the hazard from the sources is only at sufficient to conduct the analysis of path terms. long periods, so we are focusing on the long periods. 209. Section L.2, Page L-1, 1st Please provide full references or previously defined acronyms for the 4 Because Appendix N is absorbed into Chapter 7, the Paragraph of Section, 3rd NGA-West2 GMPES" the first time they are mentioned in the appendix. references are properly provided Line 210. Section L.2, Page L-1, First Please clarify whether every AZ station recorded the same set of CA The current equations were meant to be easy to understand Paragraph, Line 7 events. If not. please add text to comment how this situation is addressed but they do not capture the unequal sampling. We in Equations (L-3) through (L-8). reformatted the equations to show the unequal sampling (even if leading to more complex notation ..... ). Appropriate notation is introduced with the modified formulas. 211. Section L.2, Page L-1, 2nd Consider saying "for sources in regions" instead of "for regions", to avoid Verbiage is changed as suggested Paragraph of Section, first any misinterpretation that within-region paths are being characterized line rather than region-to-PVNGS paths. 212. Section L.2, Page L-1, 2nd Please give specific reference to the chapter, section, and figure Proper cross-reference to Section 4.2 is provided Paragraph of Section, first number(s) where the three regions are defined line 213. Section L.2, Page L-1, Please justify Eq. (L-2) as representing the average path term. This is a mean residual for a given path. Formulas are Second Paragraph, Line 4 reformatted to make it easier to understand. 214. Section L.2, Page L-1, Please define Nc;MPE* See response to comment 210 Equation L-2 215. Section L.2, Page L-1, 2nd Please replace "eq(x)" with the correct equation reference. Proper Equation reference is provided Paragraph of Section, 6th Line 216. Section L.2, Page L-1, 2nd This sentence is redundant (as the same info1111ation is conveyed by the Sentence is removed Paragraph of Section, 7th parenthetical remark two sentences earlier). If retained, please change Line "NGA-W-2" to a consistent abbreviation used throughout report. 217. Section L.2, Page L-2, Please define NSTA;. and NEQK *. See response lo comment 210 Equation L-3 218. Section L.2, Page L-2, 1st Please explain the need to preserve the range of the medians obtained Our goal is to capture the range for large magnitudes sentence after Eqn L-4 from the 4 GMPEs, and be specific about the medians being referred to. whereas the available data are for small M: accordingly, we Note also that this and the following sentence mix references to "median want to retain the range of M scaling from the GMPEs -and "mean". If this distinction is intended, please clarify; otherwise, please Clarifying text was added. The distinction between use te1111inology that consistently treats either amplitudes or log median and mean terminology is intended Median refers to amplitudes as the principal variate. PSA (arithmetic units), whereas mean refers to the log of the path term. Clarifying text was added 219. Section L.2, Page L-2, 2"c Please be specific about the "residuals" referred to in this sentence. See answer for comment 218 sentence after Eqn L-4 220. Section L.2, Page L-2, 2nd Please justify why a minimum of 5 recordings for each station is adequate The reason for requiring 5 recordings is that these estimates Paragraph on page, 1st in this analysis and explain why this number is larger than the minimum of are used to correct to GMPEs, whereas the other were used Line 3 recordings used in other analyses conducted for the project. Please also to adjust the distribution. Fewer recordings are needed to explain if those earthquakes with less than 5 recordings were discarded or estimate the standard deviation of the distribution of used in other parts of the analysis. residuals than are needed to estimate the median path effect. The selection of number of recordings is a pragmatic selection based on the number of available recordings. If we choose too large of the number, we would not have sufficient data to work with. The limitations of the selected number of recordings are discussed in the text. Additional comments are provided in Chapter 5 221. Section L.2, Pages L-2, Please discuss the possibility of mapping the path te1111 into the site term The site terms are used to correct to CA GMPES to AZ on Second Paragraph on and the consequences of such miss-mapping, if significant. average, whereas the path terms are used to distinguish page, Line 3 between path effect for regions 1 and 2&3. The net effect is the sum of the two terms. Path effect that applies to both regions could be mapped in site term but it does not matter. Clarifying text is added to the report 222. Section L.2, Page L-3, 1st Please consider using a font for the "lower-case L" subscript that is less Text is changed as suggested Paragraph on page, 1*1 line apt to be mistaken for a "one", and please write "region 1" with a font that after Eqn L-8 is less apt to be mistaken for "lower-case L". 223. Section L.2, Page L-3, 1st For completeness, please provide the equation for the standard error of Equation is added Paragraph, first 2 lines afte1 he mean path terms. Eqn L-9 224. Section L.2, Page L-3, 2nd Please explain why the value for T = 0.2 sec was not used in deriving the See response to comment 7 4 Paragraph on page, seconc central path te1111 when Figure L.5 shows that it is similar to the other line after Eqn L-10 periods, and also why the average of the few available periods is an appropriate representation for all periods. 225. Section L.2, Page L-3, 2nd Please consider removing the discussion of logic-tree branches and Discussions on weights is moved to the appropriate chapter Paragraph, 3rd Sentence weights and reserve this discussion instead for the report section on the appropriate logic-tree models. It would seem appropriate to discuss the high and low uncertainty bounds, but the evaluation of the central, low. and high values should be presented in the discussion of the logic-tree models. 226. Section L.2, Page L-3, 2nd Please explain why T = 0.2 sec was not used for the shorter periods and See response to comment 74 for T = 0.2 sec. The Paragraph, 4th Sentence why T = 2 sec was not used for the mid-periods, given that additional uncertainty is based on the number of recordings at each uncertainty was added for periods greater than 2 sec. It appears that the period, not on the difference in average values between two entire uncertainty model is based primarily on only two spectral periods. periods. Accordingly, this is not just two data points. The T = Please explain the justification and basis for the path terms, given that 2 sec period is modeled separately because additional essentially only two spectral periods are used in the assessment. epistemic uncertainty is added to T > 2 sec. Clarifying text is added to describe this. 227. Section L.2, Page L-3. Please provide rationale for the need for additional epistemic uncertainty The range from the 5 NGA GMPEs captures the epistemic Second Paragraph, 2"" to T > 2 sec, and for the approach by which that additional epistemic uncertainty below 2 seconds. but additional epistemic last sentence of section uncertainty is determined. Also, please explain why it is not needed for T uncertainty is needed at period > 2 seconds. Clarifying text is < 2 sec. added. 228. Section L.2, Page L-3. Please clarify if the uncertainty in the path term due to the small sample Because the data are from small magnitudes. we maintain general size and small magnitude range (all but 2 data point are from M<5.2 the range of the medians from the 5 NGA GMPEs to capture events) of AZ. data needs to be incorporated. the uncertainty in the large magnitude scaling. Additional text is provided. 229. Section L.3, Page L-4, 1st Please reference Figure L.8 for the statement "The 4>sr*R. (T) at a period of Figure is now properly referenced Paragraph, last Sentence 0.2 sec was not used in deriving the central model due to the large variability in the values obtained for the 4 GMPEs at this period and because sources in regions 1 , 2. and 3 do not contribute significantly to he hazard at short periods". 230. Section L.3, Page L-4. 1st Please explain why the mean estimate, including the 0.2 sec value. is not The 0.2 sec value is not relevant to the hazard and was Paragraph, last Sentence appropriate to use (even though the variability might be larger). If indeed removed from the plots to avoid any confusion. In general. he hazard is not impacted at T = 0.2 period from the California/Mexico below 0.5 sec is not relevant to the hazard, so a constant earthquakes, then that should be sufficient to ignore it. but then that value is acceptable as it does not matter. The long period leaves only three periods (all defining a slope) to describe what happens extrapolation of PhiSP-R was re-evaluated, and found that at T < 0.5 sec and T > 2 sec. Please explain the justification for assuming there are not enough data points to constraint the estimate a constant value of beyond the limits of the observations. when all above 2 sec hree of the observations defines a frequency-dependent slope. 231. Section L.3, Page L-4, 1st Please cite the specific section and figure( s) of the report where it is Proper reference is provided. pointing at Chapter 4 (planned Paragraph, last Sentence demonstrated that hazard at 0.2 sec is not impacted by sources in regions addition therein of the deaggregation from previous PSHA 1, 2, and 3. studies) 232. Section L.3, Page L-4, 2nd Please justify why a scaled chi-square distribution is appropriate and New Appendix P will address with point. Proper reference is Paragraph, 1st Sentence provide a reference for this distribution and the related equations (or provided. reference a section of the report where the issue is treated). Although the discussion of low and high values is appropriate, please consider removing any discussion of logic-tree branches and reserve this assessment for the discussion of the logic-tree models. 233. Section L.3, Page L-4, 2nd Please expand the discussion of the GOV with equations or additional text Clarifying text is provided, and CV instead than COV is used Paragraph, 2nd and 3rd (and rewrite for better clarity) to show how the COV of 0.17 was throughout the report Sentences estimated. Also please ensure that a consistent notation for coefficient of variation is used throughout the report. 234. Section L.4, Page L-4 Please provide missing references. not needed because Appendix is absorbed in main report APPENDIX M Phi SS Models for DCPP - 235. General Section 11.3 refers to Appendix M for the Tl Team's technical basis of Appendix is absorbed into main report, and technical bases giving 0 weight lo the magnitude-dependent branch. However. such are incorporated in the main report, as applicable. basis is not yet provided in this Appendix. Please add details of the technical evaluations that support 1he selection of 0 branch weight for the magnitude-dependent-cl>ss branch. 236. Section M.1. Page M-Please confirm that the acronyms ASK14, BSSA14, CB14, and CY14 See response to comment 102 1, 1st Paragraph, 2nd are defined by their full citations the first time they are used and verify Line that they are included in the list of acronyms. 237. Section M.1. Pate M-"CA" should be spelled out as "California", and should be accompanied Text is modified as suggested, and proper reference to the 1, 1 *1 paragraph. line 3 by the name of a specific dataset that has already been defined and data set is provided. listed in a table of data sets elsewhere in the report (and that table should be referenced here). The specific dataset name should be used consistently throughout the report. 238. Section M.1. Page M-Please explain why non-NGA data from regions other than Taiwan (such The Japanese residuals were not available to us at the time 1, First Paragraph, as the Japanese data set used in the PAGASUS project) are not of this project. Rather than using the Japanese data, we Line 3 considered in this project. compared the SWUS PhiSS model to the PEGASOS model. 239. Section M.1. Page M-Please indicate whether the terms "site terms and single-station within-Appendix is absorbed into main report, and terminology is 1, 1st Paragraph, 5th event residuals" have been defined in the main report prior to being included in the main report, as applicable. Line mentioned in Appendix M. If not, these terms require a specific reference to a section in the report or another appendix for their definition or they should be defined when first used in Appendix M. 240. Section M.1. Page M-Please indicate how the site terms and single-station within-event See response to comment 70 1, 2nd Paragraph, 1st residuals were calculated from the entire database for CB t4. which only and 2nd Lines fit an average anelastic attenuation term with data from distances of 80-500 km (i.e., the more distant data was not used to develop all of 1he parameters in the GMPE and, therefore, do not necessarily have unbiased between-event or within-event residuals beyond 80 km). 241. Section M. t, Page M-Please provide the justification and basis for the specific magnitude and Reference to deaggregation from previous results shown in 1, 3rd Paragragh, 1st distance ranges that were selected. Chapter 4 is provided. Sentence 242. Section M 1. Page M-Please describe the specific ,Pss terms that are referred to in this Terms are described. See reply to Comment 64 1, 3rd Paragraph, Last sentence, and explain why this sentence does not contradict the Sentence statement made in Section 11.3 (Page 11-2, Second Paragraph) that "For the global data set, a magnitude-dependence in the cl>ss is not seen" 243. Section M. t. Page M-Does this wording mean that the Lin et al dataset has been The data labeled "Taiwan refers lo both NGA-West2 and Lin 1, 4'" paragraph, 1*1 superimposed on each of the NGA-West2 datasets? Are the red circles et al (2011). Text to clarify this point has been added to sentence to denote "Taiwan" representing part of the NGA-West2 datasets, or are Chapter 5 these from Lin et al., or both? Please clarify. 244. Section M 1. page M-Please replace the lower right plot with the data distribution plot for Plot now shows the CY14 data distribution instead than the 1, paragraph, and CY14. Also, please check all the plots for accuracy; it seems odd, for duplicate of BSSA 14 data distribution. In chapter 5 Page M-5, Figure M.1 example, that the CB 14 plot shows only a handful of Italy data and no Japan data at all. 245. Section M2. Page M-This sentence seems to have a missing word. Please rewrite to make its Sentence is rewritten 2, 1"' sentence meaning clear. 246. Section M.2. Page M-Please provide plots similar to those in Figure M.4 for a wider range of Additional plots are provided 2, 1st Paragraph, 3rd spectral periods to more thoroughly document the magnitude-dependent Sentence cl>ss model. 247. Section M.2. Page M-Please consider changing the word "variances" to for clarity. Text was modified as suggested 2, 1st Paragraph, end of 3rd Sentence 248. Section M 2. Page M-2, 1"' Paragraph. Please consider a rewrite of this sentence for accuracy and clarity. Sentence was rewritten Lines 4 and 5 249. Section M 2. Page M-Please describe how the estimated was smoothed over periods A description of the smoothing algorithm is provided 2, First Paragraph, given estimates at only 5 periods. Lines 6 and 7, Figure M.3 250. Section M.2. Page M-Please provide a justification and basis for using only a magnitude-The distance dependence seen in the Rodriguez-Marek 2, 2nd Paragraph, 1st dependent <l>ss model and not a model that is dependent on both model only applied to smaller magnitudes, and disappears at Line magnitude and distance. M > 5. Therefore we have not developed a distance dependent PhiSS model. Clarifying text is provided 251. Section M2. Page M-Please correct "M.4" to "M.5. Figure number was corrected 2, 2nd Paragraph, Line 5 252. Section M.2. Page M-Please also reference Table M.2 for the a and b coefficients in Equation done 2, 2nd Paragraph, ( M-1) and explain how the "high" and "low" values in Table M.2 were Last Sentence determined. Although Table M.2 is referenced in the next section. because the a and b coefficients are presented here, their tabulated values should be referenced. 253. Section M.3. Page M-Please carefully review this sentence for accuracy and reword for clari1y. done 3, First Paragraph. Lines 1and2 Dr. Carola Di Section M.3. Page M-Please provide the technical basis for selecting 0.12 as being See new Appendix P for the CV value. We had also Alessandro 3, Second Paragraph. representative. Please also clarify whether hazard is sensitive to the performed sensitivities to CV which are describes now in Line 4 COV value and if there is significant uncertainty in selecting the value. Chapter 7. 255. Section M.3. Page M-Please add text to discuss the evidence and implica1ion of the The M-dependence of the CV has not been evalua1ed. Text 3, Second Paragraph. magnitude-independence of COV, particularly for evaluating the was revised to include this discussion. Line 4 epistemic uncertainty in the magnitude-dependent ,Pss 256. Section M.3. Page M-Please provide justification for the use of a chi-square distribution and See new Appendix P 3, 2nd Paragraph, provide a reference to this distribution and the related equations. Last Sentence 257. Section M.3. Page M-Please add text to provide a source of or derivation for the relationship See new Appendix P 3, Second Paragraph, = 2

• last sentence 258. Section M.4. Page M-Please provide the missing references. Appendix is absorbed into main report, and references are 3, References incorporated in the main report, as applicable. 259. Table M. 1. Page M-4 Please provide another table that lists the number of earthquakes and Table is provided, and text was revised to clarify that the recordings for the M5.5 and greater database. Please also indicate that statistics are for sites with at least 3 recordings. these statistics are for sites with at least 3 recordings. 260. Figure M.2, Page M-6 Please explain why not all of the common spectral periods included in This subset of periods was considered to be representative the NGA-West2 GMPEs are included in Figure M.2. of the period dependence. Clarifying text is provided 261. Figure M.3, Page M-7 Please explain why the values for the models and their averages are The averages are for the global data. For the Lin et al (2011) shown for only five spectral periods in Figure M.3. data set we only have five periods. Text is added to clarify this point.

262. Figure M.5, Page M-8 Please explain why only a subset of the available spectral periods for the The values are not stable at 10 seconds as shown in Figure NGA-West2 GMPEs are used and why there is no value at 10 sec M.2. This value at 10 seconds is not used for the smoothing. period; whereas, this period is shown in other figures. Clarifying text has been added 263. Figure M.8, Page M-Please explain why not all of the common spectral periods included in See reply to comment 260 11 the NGA-West2 GMPEs are included in Figure M.8. 264. Figure M.9, Page M-Please explain why the values for the models and their averages are Those are the periods for which the Lin et al (2011) data 12 shown for only five spectral periods in Figure M.9. was available. Clarifying text is added 265. Figure M.10, Page M-Please explain why not all of the common spectral periods included in See reply to comment 260 13 the NGA-West2 GMPEs are included in Figure M.13. 266. Figure M.10, page M-Because there are two global datasets employed in Chapter 11 and New notation is being used to clearly identify each data set, 13 Appendix M, the caption, if it alludes to "the global dataset," the text including the two versions of the global data set should make it clear that the "global dataset" referenced here is the one specifically used to derive the epistemic uncertainty in 4>ss (which is distinct from the other global dataset specifically used lo derive the central 4>ss model, for which the magnitude-dependent branch does not exist). APPENDIX N Phi _ss Models for PVNGS 267. Section N. 1, general It is potentially confusing that 4>ss and 4>sP-R are discussed in separate Appendix N is absorbed into the main report. comment appendices (N and L. respectively), even though they seem to be mutually exclusive alternative branches of the same logic-tree node. Please provide some connective discussion to clarify this relationship. 268. Section N.1. Page N-Please reconsider the use of the term "proponent" in this context. as it See answer to General comment 8 1, 1st Paragraph of may cause confusion as to whether the proponent is an outside expert or Section, 1st Line is the Tl Team. 269. Section N.2. Page N-Please quantify what is meant by "important" and provide a specific The term "important" was replaced by the quantitative 1, 1"' paragraph, line 2 (section, figure number) reference to the part of 1he report where 1hese estima1e of the fractional contribution to the hazard. Text was deaggregation results are documented. Also note the misplaced word revised accordingly. "consideration". 270. Section N.2, page N-Please reference the precise dataset names established and tabulated New notation is being used to clearly identify each data se1, 21 1 paragraph, line earlier in the report. and the section number where they were defined. and is properly referenced herein. 4 271. Section N 2. Page N-Please explain why the California database used for DCPP is not also a See answer to comment 69.Now we have a unique global 1, 1st Paragraph of viable dataset for regional Arizona sources. PhiSS -RSO model Section, Last Sentence 272. Section N.2.1, Page N-1. Please explain why the use of 3 recordings per station is sufficient to See answer to comment 220 1st Paragraph of Section, define a site term (especially since 5 recordings were used for other 1st Line aspects of the study as reported elsewhere in 1he report). 273. Section N.2.1, Page N-1. Please replace Lin et al. (2010) with Lin et al. (2011 ). Typo is corrected 1st Paragraph of Section, 2nd Line 274. Section N 2. 1. Page Judging from the identical values of N.1andM1. the global dataset Text is revised to clearly identify the unique data set. N-1 , 1" Paragraph, used in this Appendix is the same as the dataset used in Appendix M. Is Lines 6 and 7 it necessary to repeat the same plots and table here (an issue because of the two appendices instead of one)? It will also help if each dataset is precisely defined and given a unique identifier early in the report and referred to consistently by that identifier thereafter. 275. Section N.2.1, Page The language "on average of 1,200-1, 700 recordings 1,460 recordings Text is revised to remove the verbiage "1.460 recordings" N-1 , 1 '1 paragraph, from 72-106 earthquakes" is incomprehensible as written. Please clarify. Lines 5 and 6 276. Section N 2.1. Page Same comments about Figure M-1 are also applicable to Figure N.1 Agree. See answer to comment 244 N-1 , 1 *1 Paragraph, Lines 7 (Figure N.1) 277. Section N 2.2. Page Please reference the precise dataset names established and tabulated Proper reference to univoquely identified data sets is N-1 , 1 *1 paragraph, earlier in the report, and the section number where they were defined. provided lines 3-4 278. Section N 3.1. Page There appears to be a trend with magnitude when the entire magnitude The M dependence is not significant, in that is much smaller N-2, 1st Paragraph of range is taken as a whole. Please provide a quantitative definition of than the uncertainty in the constant shown in Figure N.4. All Section, 3rd Sentence what is meant by "significant" and how this definition supports the Tl of the points in figure N.3 are accommodated in the Team's assessment of assuming magnitude-independence of uncertainty range shown in Figure N.4 279. Section N 3.2. Page Please see previous comments regarding justification of the use of a chi-See comments for the new Appendix P N-2. 1st Paragraph of square distribution and the specific value for the GOV. Please also Section, 2nd and 3rd provide a basis for the "assumption" that the GOV for the European data Sentences is the same as for the global data. 280. Section N.3.3, Page Please explain the difference in the cl>ss model (derived from the same Now we have only one Phi_global_r50 applicable to both N-2, First Paragraph global dataset using the same methodology) between the greater AZ sites (Table N.3) and the DCPP (Table M.2). Please also explain the use of different assumption about period dependence for smoothing across periods (there is no period dependence for AZ). 281. Section N 3.3. Page Please see previous comments regarding use of the chi-square See comments for the new Appendix P N-2, 1 *1 paragraph of distribution and the specific value for the COV. Please also clarify section, line 2-4 whether hazard is sensitive to the COV value and whether there is significant uncertainty in selecting the value. 282. Please provide a reference to the sensitivity studies that show the References to new deaggregation plots inserted in Chapter 4 Section N 4. Page N-magnitude and distance ranges that control the hazard. are provided 2, 1st Paragraph of Section, 1st Sentence 283. Section N.4, Page N-2, Please reference Figure N-6 for a definition of regions 1, 2, and 3. Proper reference to a figure defining the Regionalization is 1st Paragraph of Section. provided. It is included in Chapter 4. 3rd Line 284. Section N.4. Page N-Appendix L refers to records in the distance range 200-500 km (section The selected distance ranges reflects the available data 2, 1"' paragraph of L.2). Please explain why a different range is used here. Same comment ranges. We needed a big enough range to have sufficient section, line 4 applies to Line 3 on next page, and Line 3 of section N.5. data to constrain the path effects while keeping our focus on the applicable range. For the global PhiSS model. the GMPEs are less reliable beyond 400 km. Clarifying text is added. 285. Section N.4. Page N-Please explain why this renders the CB 14 model unusable at large See reply to comment 70 2, 1st Paragraph of distances. Section, 2nd Sentence 286. Section N 5. Page N-Please see previous comments on justification of the chi-square See comments for the new Appendix P 3, 1st Paragraph of distribution and use of the specific value of the GOV, and the Section, 3rd and 4th presentation of logic-tree branch weights. Sentences 287. Section N.5, Page N-Please discuss the cause of the decreasing trend of cl>ss with period at The decrease trend is an empirical observation. We do not 3, First Paragraph. large distances (ie., for sources in Regions 1, 2. and 3), as shown in have an explanation for this trend Lines 7 and 8 Figure N.8. 288. Section N.6, Page N-Please correct the date of this publication to 2014a to agree with the Reference was corrected 3, 2nd Reference published date of the manuscript 289. Section N.6, Page N-Please correct the date of this publication to 2014b and include the Reference was corrected 3, 3rd Reference volume and page numbers of the published version. 290. Table N 3. Page N-6 Please correct the heading of the second column from 'CA data' to Table heading is corrected 'European data'. 291. Table N.1, Page N-5, Please clarify whether this table also includes the Taiwanese recordings Yes, that includes the Lin et al (2011) data. Text is provided Caption from the Lin et al. (2011) study. in the caption 292. Figure N.5, Page N-Please explain why only five periods are shown in this figure. These are the periods available for the Lin et al. (2011) data 10 set 293. Figure N.7, Page N-Please check the accuracy of these plots. Plots were checked for accuracy 12 294. Figure N.8, Page N-Please correct the caption to indicate that the figure is for sources in Caption was corrected 13, caption Regions 1, 2, and 3 (not 4 ). APPENDIX R Spatial Correlation 295. General Please consider formatting this appendix for consistency and visual This appendix documents work by Shahi to update his uniformity with the rest of the report (font: section. equation and page previous evaluation of the effect of the spatial correlation on numbering style, etc) the phi and tau It is an independent deliverable that is not part of the Tl Team report. Therefore. it is not up to the Tl Team to rewrite the deliverable. To make this difference clear, it is changed from an appendix to an attachment. The detailed comments (296 to 320) have been provided to Shahi for consideration in revising the deliverable 296. Abstract, Page 1, Line Please consider revising this sentence to reflect the fact that only the Done 7 model of aleatory variability was refitted. the coefficients of the median relation were fixed to the values estimated by Chiou and Youngs (as stated in Section 3, Page 4, First Paragraph). 297. Section 1, Page 1, Please consider changing the word "prediction" to "modeling". Done First Paragraph, Last Line 298. Section R. 1, Page 2, ?e appears to be the same as what is elsewhere in the report called '* The reviewer is correct in noting that \phi_e and \tau 1** paragraph, Line 8 Please make changes here. and elsewhere in the appendix. to ensure represent the same thing. We have included the following in that the notation is consistent throughout the report. the text to help the readers "traditionally $\phi_{e}S is also represented by the symbol $\tau$". We decided against changing the notation everywhere in the report because we strongly feel that using the same greek letter to denote standard deviation component is a more consistent notation. 299. Section R. 1, Page 2, Please clarify the importance of these two sentences in the context of We have added the explanation that regions refer to data 1st Paragraph, last 2 the present study. and clarify whether "regions" refers to spatial regions sparse regions in parameter space. We use the fact that sentences (e.g., California or Japan) or regions in ground-motion parameter space these median model coefficients are not pure statistical fits, (e.g., ranges of magnitude and distance). and the result from Jayaram and Baker (2010) to justify our assumption of not letting the median model coefficients to change. 300. Section R. 1. Page 2, This sentence is confusingly worded because it does not indicate for Thanks for pointing out the confusing sentence. The revised 2"' paragraph, 2"rl what pairs of things correlations are being modeled. Please reword for sentence reads "Though spatial correlation of ground-motion sentence clarity (for example. "models the correlation of ground motion intensity intensity at two sites is not explicitly considered, the between sites ... "). between-event residual $\delta_ es is shared by every recording from an event and thus implicitly models the correlation between the intensity of motion due to common eventfsource effects." 301. Section R. 1, Page 2, Please quantitatively define what is meant by "significantly". We have added the explanation that (Jayaram and Baker, 2nd Paragraph, 14th 2010, showed that the standard deviation components Line chanae bv over 10%). 302. Section R. 1. Page 2, Please replace "NGA West 2" with NGA-West2" to be consistent with Done 2nd Paragraph, 17th the acronym used by the NGA project and used elsewhere in the report Line and aooendices. 303. Section R. 1. Page 2, Please change this citation to "(Ancheta et al .. 2014)" to be consistent Thanks. We have changed the citation. 2nd Paragraph, Last with the published journal article. or alternatively reference both the Line PEER report and the journal article. 304. Section 2, Page 3, The statement that a magnitude-dependent model is "closer" to the truth The motivation behind this statement comes from the fact First Paragraph, 1"' than the magnitude-independent model seems to contradict the Tl that several NGA-West2 models use a magnitude dependent sentence Team's assessed branch weights in the GMC logic tree (equally functional form for their aleatoric uncertainly models (e.g., weighted in Fig 11.1, 12.1, 12.2, and binary weighted in Fig 10.1 ). ASK, CY, CB). Our statement is made in the context of Please revise or explain how this sentence is consistent with the Tl ground motion models in general, whereas the Team's assessment of these two alternatives. Please also provide a recommendation of the Tl team may be appropriate for this reference to publications by the cited "ground-motion modelers" that particular project. suggest magnitude dependence. 305. Section R.2, Page 3. Please describe what simplifications were made to the Chiou and We do not include the effects of soil non-linearity on 2nd Paragraph, 1st Youngs (2014) variance model for the present study. variance. The text is updated to note this simplification. Sentence 306. Section R.2. Page 3, Please define what the symbols "s" and "t" refer to in Equations (3) and We have updated the text to include that s_ 1, s_2. t_ 1, and 2nd Paragraph, 3rd (4). t_2 are model coefficient fitted from data. Sentence 307. Section R.2. Page 3, It might be useful to clarify parenthetically that "s" and "s prime" Done 3rd Paragraph, 4th mentioned here is not the same as "s" in Eq. (4). Line 308. Section R.2. Page 3, Please justify why the equations for "r" given by Jayaram and Baker In their report Baker and Jayaram studied the spatial 3rd Paragraph. 9th (2009) are also appropriate for the within-event residuals of CY14. correlations computed for several well-recorded Line earthquakes. Their results show that the value of the range parameter (r) has similar value across earthquakes if the Vs30 values are not clustered together. 309. Section R.3, Page 4, Please explain why the results of Jayaram and Baker (2010) and Hong Baker and Jayaram explain how including spatial correlation 1st Paragraph, 2nd et al. (2009) are robust enough to permit assuming that the CY14 changes the values of the values of the inter and intra event Sentence coefficients will not change. standard deviation without changing the total standard deviation. Since the total standard deviation does not change significantly, we do not expect large changes in the total residuals. Thus. we should not expect large changes in the median model coefficients. 310. Section 3, Page 4, This equation (Eq. 8) seems to be a duplicate of Eq. 2. Please review it The reviewer is correct in noting that equations 2 and 8 are First Paragraph, Line and make clarifications as needed. duplicates. These equations serve different purpose in the 8 two places. Equation 2 represents the relationship between the total residual, the within event residual, and the between event residual. Whereas equation 8 shows how assuming that the coefficients of CY14 model do not change simplifies regression the problem into a residual splitting problem. 311. Section 3, Page 4, Please review whether "I)_." in these equations should really be "i:.s, and Thanks for catching the typo. The \delta_{ es} should have Second Paragraph, consider clarifying the intent of these equations. been \epsilon_{es}. We have added text to explain how these Lines 3 to 5 (Eq. 9 to equations are used to fit model coefficients Eq 10) 312. Section R.3. Page 4, Please provide a published statistical reference for Eqs. (9). (10), and Equations 9, 10 and 11 are mathematical truth derived from 2nd Paragraph, (11 ). assumptions stated in the report (after we fixed the typo). Equations (9) to (11) They stand without any need for citations. 313. Section 3, Page 4, Please justify the assumption of non-correlation in light of the presence The assumption is made to make the computation tractable Third Paragraph. of a site-specific term, which could induce correlation between residuals This is an assumption used in all ground motion models that Lines 3 and 4 across different events recorded at the same site. do not include the site term. This includes CY14 models. 314. Section R.4, Page 5, The standard deviations derived without considering spatial correlation We agree with the reviewer that the comparison of standard 2nd Paragraph, 1st should have been similar to those obtained by CY14. Please show that deviations without correlation with the standard deviations Sentence this is the case or, if not, why not. from CY14 model can be a good validation test, and including this will improve the quality of the report. This comparison is difficult to make here because we use a simplified form of the standard deviation model. For example, the CY14 standard deviation models include the effects of soil nonlinearity, which is completely ignored in this report. Any comparison without adjusting for the effects of simplification will not be meaningful and may end up confusing the reader. These adjustments are non-trivial and are outside the scope of this mini report. We will try to derive a good scheme to adjust for the model simplifications and include the suggested comparison in a future publication. 315. Section R.4. Page 5, Please clarity whether "these results" refers to the homoskedastic or The results refer to both homo-and heteroskedaslic models. 3rd Paragraph, 1st heteroskedastic results, or both. Line 316. References, page 5. 4'" reference Please provide a volume number for this reference. Done 317. References. Page 6, Please update this reference to include volume and page numbers Done 3rd Reference 318. References, Page 6, Please provide a more complete reference (e.g .* conference dale, Done 6th Reference conference proceedings title, publisher, etc.). 319. Table 1, Page 7, Please clarify that these are "standard deviation model" coefficients, and Adding the word "standard deviation" with model coefficients Caption not median model coefficients. is slightly confusing, as model coefficients are estimates and have their own errors and standard deviations. The report is focused on standard deviation models, and it is the only model we fit. It is clear from context that the coefficients are for the standard deviation model and not any median model. We did not change the table title to avoid any potential confusion. 320. Table 2, Page 8, 5th The value "0.367" appears to be a typo. Please verify this value and Thanks for catching the typo. We have corrected it to 1.008 Row, 3rd Column revise accordingly. Comment Response Table Comment Location in PPRP Comment Summary of Revisions to Report Number Text CHAPTER 6 GMC Models for the Median 321. Section 6.1, Page 6-1, The "base-model GMPEs" are called by other names-e.g., "proponent Done mostly throughout the report (Rev.1) and completed (Rev. First Paragraph, First Line GMPES", or "selected candidate GMPEs (as in the next paragraph of 2) this section) -in other parts of the report. Please select an appropriate name for these GMPEs and consistently use this name throughout the report and appendices. If "base model" is intended to mean something else in this context, please define this term the first time it is used and include it in the list of terms. 322. Section 6.1, page 6-1, Please explain the concept of a "space of GMPEs," or make it clear that We refer to the Draft PEER report on epistemic uncertainty paragraph 2, line 2 this is a concept that is going to be fully explained later in the chapter, (Attachment E for Rev.1. Introduction to Appendix H for Rev.2) and reference the section where the explanation is given. It would also for a comprehensive overview of the Sammon's map approach be advisable to develop a terminology that distinguishes actual GMPEs and reasoning from the virtual GMPEs constructed from the common form, as the lack of consistent, distinct terms for these entities is a frequent source of ambiguity in the rest of the chapter. 323. Section 6.2.1, Page 6-1, Please replace "Akkar et al. (2013, 2014 )"with "Akkar et al. (2014a,b)" Citations in text/tables/figures and references list are fixed 2nd Bullet here and elsewhere throughout the chapter to indicate that both the throughout the report original manuscript and the erratum were published in the same year. 324. Section 62.1. page 6-1. Idriss (2014) is referred to here as 114, whereas it is ld14 in the figures Done 6'" bulleted item and elsewhere in the text. Please make these acronyms consistent. 325. Section 6.2.1, Page 6-1, Zhao and Lu (2011) is not a GMPE, but a method for accounting for Done 8th Bullet saturation of magnitude scaling. Please summarize how this magnitude scaling is used to construct a GMPE for purposes of 1he Tl Team's evaluation and provide a more meaningful description and acronym for this model. 326. Section 6.2.1, page 6-2, Please indicate quantitatively what is meant by "large magnitude" in this Done 1st paragraph on page, context. line4 327. Section 62.1. Page 6-2, Please provide a reference for the finite-fault simulations (e.g .. Appendix Done 2nd Paragraph on page, J as well as citations to references in the list of references). 2nd Sentence 328. Section 6.2.1, Page 6-2, Please provide a more complete citation to "Idriss". Fixed: now reads "Idriss (2014)" 3rd Paragraph on page. 10th Line 329. Section 6.2.1. page 6-2, Please provide additional justification for the exclusion of 114 at Done 3'" paragraph on page, distances less than 3 km, beyond its status as an outlier relative to other last sentence GMPEs and simulated data. 330. Section 6 2. 1. page 6-2. Please check the magnitude of the Kocaeli earthquake. which is given Done 4*h paragraph on page, as 7.51 in the NGA-West 2 flatfile. line 2 331. Section 6.2.1, page 6-2. Please include a reference to the report section (and figure number if Done S"' paragraph in section appropriate) where the sensitivity result cited here is demonstrated. (last on paQe), Line 1 332. Section 6.2.1, page 6-2. The figure is for a relatively long period (0.5 Hz), so it would be helpful We refer to the previous hazard deaggregation results shown in 5"' paragraph in section, here to complete the argument by recalling that the long periods are the Chapter4 Line 4 worst case for hazard sensitivity at this distance range (and to reference the report section and figure(s) where that is demonstrated). 333. Section 6 2. 1. page 6-2. Please provide a more precise statement of what is meant by "the Done last paragraph of page, candidate GMPEs is reasonable for application to DCPP" and provide last line the justification for this judgment, or a reference to the report section where this justification is given. 334. Section 62.2. Page 6-3, Please replace "Bindi et al. (2014)" with "Bindi et al. (2014a,b)" here and citations in text/tables/figures and references list are fixed 3rd Bullet elsewhere throughout the chapter to indicate that both the original throughout the report manuscript and the erratum were both published in the same year. 335. Section 62.2. page 6-3. Please explain more fully the justification for excluding the Bindi et al. The text seems clear -reference to figure 6.6.2-1 is provided 1*1 paragraph of section, (2014) model, or provide specific reference(s) to the section(s) where lines following bullets that justification is fully explained, and explain whether ASB 14 has similar limitations. 336. Section 6.2.3, page 6-3, Please reference more specifically-section number, and figure number Done 1** paragraph of section, if appropriate-where the sensitivity result cited here is demonstrated. Line 2 337. Section 6.2.3. page 6-3. Please state quantitatively what is meant by "large magnitude" in this Done 1** paragraph of section, context. Line 3 338. Section 6.2.3, page 6-3. The structure of the final sentence of the paragraph is a little awkward Done paragraph 1 of section, (particularly its formulation as a rhetorical question), and the expression lines 4,5 "large distance attenuation" is ambiguous in meaning. Please consider rewriting the sentence to improve its clarity and precision. 339. Section 6.2.3, Page 6-3, Please replace "Kashida et al. (2014a)" with "Kashida et al. (2014)" here citations in text/tables/figures and references list are fixed 2nd Paragraph of and elsewhere in the chapter to reflect the fact that there is only one throughout the report Section, 3rd Line such reference listed in the references. 340. Section 6.2.3. Page 6-3, Please explain how the California event terms were calculated, or The event terms were provided by NGA modelers. Clarifying 3rd Paragraph of Section. provide a reference to the report section where the explanation is given. text was added Last Sentence on page 341. Section 6.2.3, page 6-4. Here and elsewhere, "California/Mexico" should read "California and Edits applied paragraph 4 of section Mexico" for clarity. Same in the next paragraph where "southern/central" (2"d on page), last line should read "southern and central " 342. Section 6.2.3. Page 6-4, Please include the Phillips et al. (2013) reference in the list of this reference has been added (which is Phillips, 2014)--text last paragraph of section, references. changed accordingly 2nd Line 343. Section 62.3, page 6-4. The strong frequency dependence of Q evident in Figures 6.2.3-2 and Clarification added 5"' (last) paragraph of 6.2.3-3 increases the differences between California and Arizona Q at 5 section, last sentence Hz (upper left panel of each figure), so please reference the sensitivity studies that demonstrate the absence of hazard significance at 5 Hz for California sources. 344. Section 6.3, general The relegation of part of the hanging wall discussion to Appendix K is Appendix K was integrated into Chapter 6 somewhat awkward and inefficient. Please consider integration of the material from that appendix into the various subsections of 6.3. 345. Section 6.3, Page 6-5. 1st Please include the Abrahamson and Silva (2008) and Campbell and References added Line on page Bozorgnia (2008) references in the list of references. 346. Section 6.3, page 6-5. The statement that Rjb implicitly accounts for the hanging wall effect Sentence revised to clarify this point last paragraph of section, could be seen as contradicting the result noted later that the Rjb last sentence distance metric alone does not account for the dip-dependence of the hanging wall effect. Please modify this statement to note that Rjb does not agree with simulations for shallow-dipping scenarios and reference the sections of the report where this is discussed. 347. Section 6 3.1. page 6-5. Please consider whether "moderate" is a better descriptor than Done 1** paragraph, Line 3 "average", in order to avoid the suggestion that this is a rigorous statistical measure. 348. Section 6.3. t, Page 6-5, Please explain why the Rjb-based ASB14 GMPE was not used to Clarification added 1st Paragraph of Section, evaluate HW effects, given that the Rbj-based BSSA14 GMPE was 4th Sentence found to be suitable. 349. Section 6 3.1. Page 6-5, Please provide a specific reference to the report section that describes Done 2nd Paragraph of the "additional simulations" that were done for the SWUS project. Section, 1st Sentence 350. Section 6.3.1, page 6-6. The phrase "Moves off of the hanging wall" is ambiguous, as it does not Sentence revised 3*d paragraph of section make it clear whether the reference is to distant points still on the (1'1 on page), line 3 of hanging wall side of the surface projection of the top of the rupture, to paragraph points on the footwall side of the surface projection of the top of the rupture. or to both. Please clarify. 351. Section 6.3. t, page 6-6, The phrase "Moderate magnitude scaling" is ambiguous. Please clarify; Done 3'" paragraph of section for example, if the intent is to refer to scaling at moderate magnitudes, (1 on page), line 5 of please hyphenate as in the phrase "moderate-magnitude scaling." paragraph 352. Section 6 3.1. page 6-6. The notion of "magnitude taper" has not been defined. and by itself is Sentence revised to clarify this point 3*d paragraph of section ambiguous. Please clarify. ( 1 "1 on page), 2*** to last sentence 353. Section 6.3.1, page 6-6. The discussions in Appendix J (Pages J-41 and J-42) and Appendix K Sentence revised 3*d paragraph of section (Section K.1.2) suggest that the magnitude tapers of ASK14 and CB14, ( 1 *1 on page), second to but not CY14, are too strong compared to the magnitude scaling of the last sentence HW effect revealed by the simulated data Please revise this sentence to reflect the conclusions described in Appendix J and Appendix K. 354. Section 6 3.2. Page 6-6. At this point in the chapter the Rjb-based models have not been Reference to "Donahue and Abrahamson" provided 1st Paragraph of Section. eliminated as being inappropriate. Please explain why the Rjb-based 2nd Sentence models are not used in developing the HW model. 355. Section 6 3.2. page 6-6. The scaled-backbone approach has not been defined nor is a reference Reference provided 1** paragraph of section, cited. Please correct this. Line 4 356. Section 6.3.2, Page 6 -6, To avoid misinterpretation, please include text to note that, although a Text included First Paragraph, Last magnitude taper was not explicitly included, Eqs. (6.3-1) and (6.3-2) still Sentence provide a magnitude scaling of the HW effect, as was explained in Appendix J (Page J-42). 357. Section 6.3.2, Page 6-6, Please clarify how the total hanging wall effect is to be modeled by the 3 they are multiplicative factors, formula is now fixed 2"c paragraph of section, equations (e.g., is it the product of the three factors defined in these Eqns 6.3-1.2,3 equations?), and also define the variable "W". 358. Section 6.3.2, Page 6-6, Comprehension of this sentence depends upon familiarity with Appendix Not a problem anymore because the Appendix K is now 3rd paragraph of section, K. For example, it does not make sense to say "Five equally weighted integrated with Chapter 6 line 1 alternative HW factor models were developed ... ",because, logically. models have to be developed before they can be assigned weights. Nor is it clear what is meant by equal probability of the C 1 coefficient. Please rewrite and expand the text to make this section sufficiently self-contained to be understandable. 359. Section 6.3.2, Page 6-6, The terminology "weighted factors" in Lines 2 and 3, is a source of Not a problem anymore because the Appendix K is now 3rd paragraph of section, confusion, and without familiarity with Appendix K, the sentence is integrated with Chapter 6 2"" sentence incomprehensible. Please reword and expand for clarity, and give a more specific reference to the relevant appendix subsection(s). Please note that this is a place where the division of the material between the chapter and the related appendix seems especially inefficient. 360. Section 6.3.3, Page 6-7, Please indicate that additional comparison plots similar to Figure 6.3.3-1 Not a problem anymore because the Appendix K is now 1st Paragraph, 4th are given in Appendix K. integrated with Chapter 6 Sentence 361. Section 6.3.3, Page 6-7, The assessment that Rjb-based HW models are not appropriate for Discussion added 2nd Paragraph shallow dips is important. Please provide an example plot to show that these models are not appropriate and that Rrup-based models adequately model HW effects. and reference where in the report or appendices the discussion of this topic can be found. 362. Section 6.4, Page 6-7, Please explain the following: What does "mutually exclusive" mean? Are Discussion added First Paragraph, Third the candidate GMPEs mutually exclusive? Why is it important to use Line mutually exclusive GMPEs for the characterization of the CBR of median amplitude? What are the impacts on hazard if GMPEs are not mutually exclusive? 363. Section 6.4. page 6-7. 1" "Sammon's mapping" is called "Sammon's map" in Section 6.1. If there Consistent terminology used throughout the report paragraph of section, is no distinction between these. please use a consistent terminology. 11 364. Section 6.4. Page 6-7. The term "base model" has not been defined at this point in the chapter. Definition provided 2nd Paragraph of Please define the term "base model" the first time it is used and include Section, 1st Line it in the list of tenms. 365. Section 6 4. 1. Page 6-8, Please expand this sentence to explain why a common functional form Discussion added 1st Paragraph of Section, for all of the candidate models is needed or reference appropriate 1st Sentence sections in an appendix where this information can be found. 366. Section 6 4. 1. Page 6-8, Please indicate what is meant by the phrase "induces a distribution of Discussion added 1st Paragraph of Section, GMPEs", and indicate where in the chapter this concept will be 3rd Line expanded upon. 367. Section 6 4. 1. Page 6-8, There could be confusion when the term "models" is used between Consistent terminology used throughout the report 1st Paragraph of Section, whether this refers to the candidate GMPEs or to the simulated GMPEs. 7th Line Please select a common terminology for these two types of models and use this terminology consistently throughout the report and appendices in order to avoid confusion. 368. Section 6.4. 1. Page 6-8, Please be more specific by what is meant by "scaling". If it refers to the Clarification provided 2nd Paragraph of scaling terms in the GMPEs, please consider replacing "scaling" with Section, 3rd Line "scaling terms" here and elsewhere in the report and appendices. Please also qualify what type of scaling is meant when the term is used elsewhere throughout the report and appendices. 369. Section 6.4. 1, page 6-8, Please define NML as an acronym for "normal" here if this is the first Done 2"c paragraph of section, 4"' line after Ean 6.4-1 time it is used and include it in the list of terms. 370. Section 6.4.1, page 6-8. Please define the acronym "SS" (implying strike slip) the first time it is Done 2"" paragraph of section. used and include it in the list of terms. 8111 line after Eqn 6.4-1 371. Section 6 4. 1. page 6-8. Please clarify what SS NML and SS REV mean and replace "based on Sentence rewritten to improve clarity 2"' paragraph of section, the scaling in the eight candidate GMPEs" with more precise language. last 2 sentences Also explain why the specific scenarios for estimating SS:REV and SS:NML factors are appropriate and if the results are sensitive to the choice of the selected scenario. Please also explain why the same scenario is appropriate for both DCPP and PVNGS, considering that their hazard is impacted by potentially different magnitudes and distances. 372. Section 6.4.1, page 6-9. Please indicate what function is being referred to in the statement '"this New figures have been inserted showing filling of common-form 3*d paragraph of section, function," and by whom it is considered to have the stated flexibility. If GMPEs to candidate GMPEs, and Mand R residuals for the ( 1 *1 on page) lines 2 and this is the assessment of the Tl Team, please say so, and provide the scenarios used for the fitting 3. basis for this judgment by demonstrating that Eqs. (6.4-1) and (6.4-2) are flexible enough to capture the full range of scaling of the selected candidate GMPEs. That might entail, for example, showing the misfits to the original GMPEs as a function of magnitude and distance. Also, please discuss whether the misfits to the original GMPEs significantly affect the hazards, or reference the report section where such a discussion is provided. 373. Section 6 4. 1. Page 6-9, Please explain why this transformation of coefficients is necessary and Explanation added 3'" paragraph of section how it leads to squared coefficient terms in Eq. (6.4-2). (1st on page), 3rd Sentence 374. Section 6 4.1. page 6-9. Please check the equation. Shouldn't a6(7) be squared? Yes, it should be squared 3'd paragraph of section (1 on page), Eqn 6.4-2 375. Section 6.4.1, Page 6-9, Please clarify what the phrase "the square" refers to with respect to Eq. Clarification added 3*d paragraph of section (6.4-2) and/or the definition of the model coefficients. (1st on page), 13th Line 376. Section 6.4. t, Page 6-9, The intended point of this sentence is unclear. Please revise to make it Sentence rewritten to improve clarity 4*h paragraph of section clear. (1" paragraph after Eqn 6.4-2). 1*1 sentence 377. Section 6 4. 1. Page 6-9, Please justify that the Ztor effects of the ASK14, CB14, and CY14 Ztor is not used in Rjb-based models, but the effect is captured 4'" paragraph of section GMPEs are adequately captured by the common-form models with a8 = in the Rrup-based models (1 paragraph after Eqn 0. 6.4-2), znc sentence 378. Section 6.4.1. Page 6-9, Please describe what the three Ztor values are supposed to represent Weights for the Ztor values given 4'" paragraph of section and how they were used in the regression analysis (e.g., were they ( 1 "1 paragraph after Eqn equally weighted or weighted by some other probability distribution). 6.4-2), last sentence Also please revise the reference to the Ztor model of CY14 to be more specific (e.g., "the Ztor-M relationship developed by CY14"). 379. Section 6.4.1.1, page 6-9, The explanation in this section is incomplete, in that it is never explicitly Section restructured to improve clarity general comment stated that numerical log(Sa) predictions of each GMPE, for the given M and Rx set. are used as data to determine a best-fitting coefficient vecto1 for the common form to that GMPE, nor what fitting criterion is applied. Please make the explanation more complete. This same comment applies to Section 6.4.1.2. 380. Section 6.4.1.1, Page 6-9, Please explain what is meant by the phrase "for comparison of the Sentence and section went through major reconstruction -the 1st Paragraph of Section. GMPEs". specific verbiage in the comment has been modified 3rd Line 381. Section 6.4. 1. 1, Page 6-9, Please explain how predictor variables Rrup and Rjb were determined, We added a clarification on how the geometry was construc1ed 1" Paragraph, first 2 lines given M and Rx, and clarify who the '"developers" are (e.g., the NGA-given M and Rx after the bullets West2 developers or the candidate GMPE developers meaning the Tl Team) 382. Section 6 4. 1. 1, Page 6-The phrase" ... is only included to constrain the fitted models at large Clarification added 10, 1" paragraph, 1" line distances ... " has the connotation that the large-distance scenarios are on page used in a limited fashion in the fitting process. Please clarify and revise this paragraph as needed. 383. Section 6.4. 1. 1, Page 6-Please provide a reference in the report or appendices where the Done 10, 1st Paragraph, 3rd definition and calcula1ion of "hazard-relevant" scenarios can be found. Line 384. Section 6.4. 1.2, Page 6-Please clarify who the "developers" are (e.g., the NGA-West2 Done 10. 1st Paragraph of Section, 2"" line after the developers or 1he candidate GMPE developers meaning the Tl Team). bullets 385. Section 6.4.1.2, Page 6-Please explain the basis for "assuming" a 50-degree dip and indicate 50 degrees is a value consistent with the SSC models. 10. 1st Paragraph of Section, 2"" line after the whether the results are sensitive to this assumption Sensitivity on that assumption was not evaluated bullets 386. Section 6 4.2. General To provide more complete documentation. please list the covariance The covariance matrices are provided as electronic attachment matrices in Appendix H. to Appendix H 387. Sections 6.4.2 and 6.4.3, The method used to generate the simulated GMPEs and project them See answer to 387. Also, the methodology is described in the General comment onto Sammon's maps is new and requires detailed documentation to report (Attachment E for Rev.1; Introduction to Appendix H for fully understand the methodology. Please provide more detailed Rev.2) documentation on the generation of the covariance matrices, the simulated GMPEs, and the Sammon's maps. including all related equations, either in Chapter 6 or in an appendix. 388. Section 64.2. page 6-tO, This short section is mainly devoted lo describing the use of Title changed section title interpolation to facilitate the estimation of the coefficient correlations. It is not clear what the title "generation of models" refers to. In the subsequent section (6.4.3), model generation seems to refer to the sampling of the coefficient space to create sample GMPEs. so the use of "model generation** as the title of Section 6.4.2 seems confusing. Please consider changes to remedy this confusion. 389. Section 64.2. page 6-tO, Please explain the difficulties encountered in estimating the correlations The Kullback-Leibler-divergence approach was used to respond 1** paragraph of section, of the coefficients using the original GMPEs alone. and justify how it is to this question. Text added to the report. sentences 2,3, and line 5 mathematically possible with the addition of the interpolated GMPEs to better capture the correlations. Also provide the rationale for the interpolation weights selected, and clarify whether the interpolation was done by interpolating the coefficients or by interpolating the ground motion vectors and refitting to the common form 390. Section 64.2. page 6-tO, The last set of weights (2/3, 1/2) do not add to 1, while the other two It was a typo and it has been changed 1" paragraph of section, sets do add to 1. Please review and revise as needed. line 5 391. Section 6.4.2, Page 6-11, Is this approach (for treating the case T>3 sec) mentioned for the first Reference added at the beginning of Chapter 6 2"" Paragraph of section time here? If so, please add a paragraph in Section 6.1 so the readers ( 1 *1 on page). Last are aware of it from the very beginning. Sentence 392. Section 6 4.3. page 6-11, Please add an explanation of what is meant by model generation and Section rewritten to improve clarity 1** paragraph of section how it is done At this point, for example. there has been no explicit (1 on page), 1" sentence explanation that models in this section are generated by sampling the on page common-form coefficient distribution estimated in the previous step, nor have any necessary assumptions about the joint distribution of the coefficient distribution been explicitly stated. 393. Section 6.4.3, page 6-11, Please clarify what is meant by "for a few scenarios. Doesn't Figure Scenario clarified in text and labeling 1" paragraph of section, 6.4.3-1 apply to just a single set of predictor variables (i.e., a single 3'd sentence value each for magnitude, distance, and style of faulting)? In addition. please state what predictor values were used (that information should be in the figure caption as well). 394. Section 6 4.3. page 6-11, Please indicate by whom the judgment was made. and on what basis. Clarifications added 1" paragraph of section, and consider whether "range" is the appropriate term here, as opposed last sentence of to, e.g., "distribution" or "center, body, and range" (there are other paragraph instances throughout the report where the usage of "range" should also be reviewed and revised where appropriate). 395. Section 6.4.3, page 6-11, Please clarify whether the good agreement seen in the example We show a new figure where we plot the standard deviation 1 paragraph of section, scenario was also observed in all other scenarios important to the from 7500 and 2000 models for all scenarios in the vector. last sentence of hazards at DCPP and PVNGS. paragraph 396. Section 6.4.3. page 6-11, Some explanation of the nature of the Sammon's map should precede The structure has been reorganized 3'd paragraph of section, this instance of its application. Please consider doing some 1** sentence reorganization of this section to put the developments in a more logical order. 397. Section 6 4.3. page 6-11, The range of values of the Sammon's map coordinates in Figure 6.4.3-2, Changes applied to Chapter 6, 8 and 9, as applicable 3'" paragraph of section, for the original GMPEs, is roughly plus/minus 10. This is more than an 1" sentence order of magnitude greater than the range shown in, e.g., Fig. 9.1-3b of Chapter 9. Please explain the reason for the difference. Also please explain the reason for the difference in axis labels in different parts of the report, i.e .. "C1 ,C2" is used here and in Chapter 9. versus the axis labels "In units" shown for seemingly analogous plots in Chapter 8 and Annendix H. 398. Section 6.4.3, Page 6-11, Please explain why there is a trade-off between the "likelihood and an Explanation has been provided, and entire sentence is now in 4th Paragraph, Last 2 optimized standard deviation", what the sensitivity of the results is to Chapters sentences using a fixed standard deviation, and what the rationale is for selecting that value from BSSA 14 over the other GMPEs. 399. Section 6.4.3, Page 6-11, Please describe the Tl Team's reasons for including the simulated data Explana1ion has been provided, and entire sen1ence is now in 5'h Paragraph, 1" in the model evaluation, or point to the section where those reasons are Chapters Sentence described. 400. Section 6.4.3, Page 6-12, Please provide a reference for 1he "80% and 20%" proportions of relative Explanation has been provided, and entire sentence is now in 2nd Line on page rates of normal and strike-slip mechanisms for the Arizona sources. Chapters 401. Section 6.4.3, page 6-12, Please rewrite this sen1ence to improve clarity. It is not clear wha1 part of Sentence rewritten to improve clarity 7'h paragraph of section the analysis was done using the central HW term, nor at what stage the (2" on page), 2°d and 3*c random HW models are introduced instead, nor why this two-stage sentences analysis method was chosen. 402. Section 6.4.3, Page 6-12, Please provide citations for principal component analysis and Sammon's They are provided in the beginning, in Section 6.4. We do not 9th Paragraph of section (41h on page), 1 *1 maps if they haven't been provided previously in the chapter. see reasons to repeat them Sentence 403. Section 64.3. Page 6-12. Please describe the Tl Team's motivation to base the selection of the Goal is to capture the range in hazard. Also look at the scatted 9th Paragraph of section representative model on the resulting hazards, and to select the model hazard from a cell. Figure inserted (4'h on page), 2"d with hazard closest to the mean hazard (as opposed to. e.g .. the median Sentence or another quantile hazard level). Please also describe the scatter in the hazard from models in the same cell. 404. Section 64.3. Page 6-12. Please verify that the simplified SSC models for DCPP and PVNGS No, they are not consistent but they are representative of the 9th Paragraph of section being used are consistent with the final SSC models for these sites. type of sources -We are not meaning to reproduce the same (4th on page), 3'° final hazard as if we were using the final SSHAC L.3 SSC Sentence models. Also, the simplified models were derived before the final SSC models are done. The general features are however comparable 405. Section 6.4.3, Page 6-12, Please explain the basis for selecting the "one specific HW model". Clarification provided 9th Paragraph of section (4th on page), 6111 line 406. Section 6 4.3. page 6-12, The concept of using random HW models in the development of the We have re-written the sentence to explain and justify the two 9'" paragraph of section Sammon's maps for PVNGS and a random HW model assigned after different approaches for OPP and PVNGS (41" on page), last the selection of a GMPE for each cell for DCPP is unclear. Please sentence provide additional explanation of how this method is applied and why it is needed in order to help the reader better understand the methodology. 407. Section 6.4.3, page 6-12, Please clarify what is meant by an approximately uniform distribution of Such statement is made in Section 6.3. The factors are normally 9th paragraph of section hanging wall factors (e.g., according to Appendix K, the HW factors were distributed, but the models are sampling. (41h on page), last developed under the assumption of a normal distribution). and why it is sentence important. 408. Section 6.4.3, page 6-12, Please describe how the outputs of principal component analysis No further explanation will be added in the text, because it has 10'h paragraph of section (presumably, a set of 2-D coordinates) are used as inputs for the been already mentioned before that the methodology is well (5th on page), 1*t sentence construction of Sammon's maps, and provide a reference for the described in the report (Attachment E for Rev.1; Introduction to "principal component analysis and Sammon's maps" methodology that is Appendix H for Rev.2) being used 409. Section 64.3. page 6-12, Please indicate whether the model vector concatenates a set of periods, Section rewritten to improve clarity 101h paragraph of section or a separate model vector is constructed for each of a set of periods. In ( 51h on page), 2"d either case, please indicate what set of periods was used. Also please sentence consider changes to emphasize even more explicitly that the vector space is a space of ground motion valued n-tuples, and to draw a clear distinction between this vector space and the space of common-form coefficient vectors used in the model generation stage. 410. Section 6.4.3, page 6-13, Please rewrite this sentence (and perhaps add additional text) to make Section rewritten to improve clarity 10'h paragraph of section its meaning clear. The explanation should clarify that each vector (1" on page), 1*t full component is a In( Sa) value for a particular combination of predictor sentence on page variables. The lists of predictor values (for DCPP and PVNGS, respectively) should also be given at this point (e.g .. are they the values listed later on this page and called "deaggregation bins" or values listed on Pages 6-9 and 6-10?) Presumably one of those sets was used in the fitting and the other in model generation, but it is difficult for the reader to figure this out. The explanation should also clarify that the analysis is done independently at each period. if that is the case. 411. Section 6.4.3, page 6-13, Please be precise and consislenl in the use of terminology. The symbol Done 101" paragraph of section "w" in this line is defined as the importance of the scenario, bul in lhe (1st on page). 1 *1 line after next sentence it is call the "weight," and later something called Eqn 64-4 "deaggregation weight" is referenced. If these all mean the same thing, the terminology should be consistent; if they do not, their distinction should be clarified. 412. Section 64.3. page 6-13, This line states that the weights are computed from "the deaggregation." Plots showing weights have been added Section has been re-101" paragraph of section But this is the first time "deaggregation" has been mentioned in the written. Approach described in greater details for both PVNGS ( 1 on page), 2nrl line afte1 chapter, so the use of the definite article (indicating something already and DCPP applications. Return periods and a table showing Eqn 6.4-4 introduced) is very confusing. Please rewrite this statement to make it ground motion levels have been added to the texl. clear that a new element is being introduced into the analysis. Please also be more specific than just referring generically to "deaggregation" by saying, e g , "hazard deaggregation matrix" and by specifying what return periods and spectral periods are used to perform the deaggregation. 413. Section 6.4.3, page 6-13, Please clarify what GMPE distribution is referred lo here, and what is Clarification added 10t* paragraph of section meant by "mean model." For example, is this distribution that of the eight (1st on page). 2r.d line afte1 original GMPEs, or of the 2000 virtual GMPEs in the constructed Eqn 6.4-4 ensemble, and is the "mean model" the virtual GMPE that occupies the position in Sammon's map space that represents the geometrical centroid of the original GMPEs? 414. Section 64.3. page 6-13, The term "deaggregation weight" has not been defined. Please explain Entire description of the weights has been redone 101" paragraph of section how ii is related to the deaggregated hazard (e.g., is it some function of (1 on page), 3"' and 4'" the probability of exceedance value at a given ground motion level, or line after Eqn 6.4-4 simply the probability value itself, normalized in some way?). Please also state precisely and quantitatively what was done. and include the defining equation for the deaggregation weighl. 415. Section 6.4.3, page 6-t3, The sta1ement that the mean of the "deaggregation weights" is "used as Formulas corrected for consistency 101" paragraph of section w" in Eq. (6.4-4) is inconsistent with the subsequent explanation in which (1" on page), line after this mean is given a differenl symbol, w_bar, and is used in Eq. (6.4-4 ), Eqn 6.4-4 in combination with the number 1/N, to give w. Please rewrite this statement to provide a precise and consistent explanation. 416. Section 6.4.3, page 6-t3, Please clarify if the "renormalized weights" are used with Eq. (6.4-4) Sentence rewritten to improve clarity 11 t* paragraph of section inslead of the mean of the 10 deaggregation weighls referred lo in lhe (2s1 on page). 3'0 line previous paragraph. 417. Section 64.3. page 6-13, Please explain how it was determined that the defined "deaggregation 1 t'" paragraph of section bins" are sufficient for the purpose of determining the scenario weights. (2" on page), 3rd line afler Equation 6.4-5 418. Section 64.3. Page 6-14 Please explain why only a mean + 3 km increment was used as an Clarification added 141" paragraph of section alternative value for Ztor and not also a mean -3 km increment. Please ( 1 on page), First Line also explain why 3 km was chosen for the increment and whether the alternative value was given a different weight than the mean. 419. Section 64.3. page 6-14, The juxtaposition of the statement that "only one Ztor value is used" for Clarifying text was added to this section 14'" paragraph of section the Rjb-based models, with 1he statement "these models do not include (lop paragraph on page), Zlor scaling," seems illogical. If Ztor does not occur as a predictor 1*1 full sentence variable in a GMPE, it is confusing to suggest that "only one value" of that variable was used. Please rewrite this statement for clarity and nr<>r.i.:inn. 420. Section 6.4.3, Page 6-14, It's not clear how the number 384 is obtained. Based on the information The correct dimensions are: 288 for DCPP; 384 for PVNGS 14th Paragraph (1st given in this paragraph. there are 6 magnitudes, 13 distances, 2 styles Model A; 192 for PVNGS Model B paragraph on page), Line of faulting, and 2 Ztor values; 6 x 13 x 2 x 2 = 312. Please clarify. 7 421. Section 6.4.3, page 6-14, This sentence seems redundant with the content of the previous Spelling corrected. Redundant text removed 15th paragraph of section paragraph, except that the cited dimension of 284 for PVNGS is (2"0 paragraph on page), inconsistent with the dimension of 384 in the bulleted list in the 1** sentence preceding paragraph and with the dimension cited in the subsequent sentences (also note that PVNGS is misspelled in both of its occurrences). Please clarify and correct. 422. Section 64.3. page 6-14, Please explain the reason for the extra step of first projecting the space Explanation provided 15'h paragraph of section using principal component analysis. (2"d paragraph on page), line4 423. Section 6.4.3. page 6-14, To avoid confusion, please consider rewriting to avoid the ambiguous Done 151h paragraph of section "2881384/192" notation (here, and elsewhere In the report). For example, (2"d paragraph on page), consider the alternative phrase '"each model corresponds to a point in N-2"' sentence dimensional space, where N has values of 288. 384, and 192 for the DCPP, PVNGS Model A, and PVNGA Model B cases, respectively." 424. Section 6.4.3, page 6-14, Please provide the basis or reference for the statement '"the first two No further explanation will be added in the text, because it has 15th paragraph of section principal components. however, typically account for about 85-90% of been already mentioned before that 1he methodology is well (2"d paragraph on page), the variance". described in the report (Attachment E for Rev.1; Introduction to 3'0 sentence Appendix H for Rev.2) 425. Section 6.4.3, page 6-14, This sentence appears to misrepresent what is presented above. Please Sentence and section has been rearranged. The logic of the 15th paragraph of section consider restructuring the sentence to begin "As described above, the discussions in now improved (2"" paragraph on page), contributions to the difference in the squared Euclidean distances .. ". 4*h sentence 426. Section 6.4.3. page 6-14, Please show the values of deaggregation weight for some example M-Plots included in text See also answers to 412 151h paragraph of section distance bins and periods. (2"d paragraph on page), last line 427. Section 6.4.3. page 6-14, Please check the definition of u.. Should the second entry in the set be 2 The correct value is 2; typo corrected 16th paragraph of section (not 0.2)? (3'd paragraph on page). first line after Eqn 6.4-6 428. Section 6.4.4, page 6-14, Please explain why an ellipse was chosen, in what sense the ellipse is The reason is that the x axes is the direction of the epistemic 1 paragraph of section, best fitting, and why the best fitting ellipse is always horizontally uncertainty scaling-explanation added here and also inserted in 2"c sentence oriented. Chaoter 8 429. Section 6.4.4. page 6-14, The correct expression here is "convex hull" (not "complex"). Please We added a plot showing the convex hull, corrected the 1"' paragraph of section, make that correction, define what it is, and consider whether the ellipse verbiage and provided explanation 2** sentence is fit to the boundary curve of the convex hull. 430. Section 6.4.4, page 6-14, The acronym "GMPE" is used indiscriminately in this chapter, Done throughout the report 1** paragraph of section, sometimes to mean specifically the original set of eight published 2"" sentence GMPEs, other times to refer to members of the ensemble of constructed virtual GMPEs. Please clarify the meaning of GMPE used here and be consistent in uniquely describing which definition of GMPE is meant when it is used elsewhere in the chapter. 431. Section 6.4.4, page 6-14, The expression uncertainty models" is used here without definition and Terms rewritten for clarity 1 paragraph of section, the resulting text is ambiguous and confusing. Please rewrite for clarity. 2"" sentence If the set of GMPEs formed from the original GMPEs with added epistemic uncertainty is going to be used repeatedly. please introduce an unambiguous terminology and use it consistently. 432. Section 64.4. page 6-t4, Since it has not been explained how the ellipse is going to be used, the Sentence rewritten to improve clarity 1" paragraph of section, significance of scaling it up is not clear at this point in the narrative. Nor 3'" sentence is the parenthetical comment comprehensible (e.g., capture the full range of what?). Please rewrite this discussion to clarify the reasoning behind centering and scaling the ellipses this way. including the reasoning behind the choice of the factors 1.5 and 0.5. 433. Section 6.4.4. page 6-14, 1 paragraph of section, This sentence is incomprehensible. Please rewrite it for clarity. Done last sentence 434. Section 6.4.4, page 6-15, Please state what data set(s) the residuals are calculated for. and clarify Clarifications added 2"c paragraph of section whether the between-event residuals are also weighted by (1" paragraph on page), deaggregation weight to emphasize the magnitudes that are more line 1 important for hazard and, if they are not weighted, please explain why. 435. Section 64.4. page 6-t5. Please provide additional discussion of the method for producing the Additional discussion provided 2"c paragraph of section ellipses and justify the 5 selected residual values used to define the (1 paragraph on page), intersection points between the residual contours and the ellipses. line 2 436. Section 64.4. page 6-t5. Please clarify the meaning of uncertainty models" (see earlier comment Verbiage replaced as "additional epistemic uncertainty" 2"' paragraph of section suggesting use of a consistent, unambiguous expression for those throughout most of the section (1" paragraph on page), 3'0 sentence models) 437. Section 64.4. page 6-t5. What is meant by the phrase broadened lo capture this range"? That is, We meant that we increased the multiplication factor of the 2"' paragraph of section please state which new contours are then selected in that case. ellipse. We added more info on the "broadening" approach (1" paragraph on page), 3'0 sentence 438. Section 6.4.4, page 6-15, Please explain what is meant by the ambiguous phrase "center of the Clarification added 2"c paragraph of section original GMPEs." If this refers to the centroid point in Sammon's map (1" paragraph on page), coordinates, please say so. line 6. 439. Section 6.4.4. page 6-15, Please give the final number of selected representative points. A table with the info has been added 2"' paragraph of section (1" paragraph on page), last line 440. Section 6.4.4, page 6-Please be specific about the quantity to which the term "range Done 15, 3*d paragraph of refers. Please also explain how the range in the location of points on section (2"d paragraph the Sammon's map relates to the range of this quantity. In addition. on page) please explain why the range of Sammon's map coordinates in Figure 6.4.3-2 is larger by more than an order of magnitude than the range of Sammon's map coordinates in Figure 6.4.4-1 and all the other Sammon*s map figures in the report. 441. Section 64.4. page 6-t5. This is the first time the expression "epistemic models" has been used See answer to comment 436 3'" paragraph of section Please clarify what is meant by this expression (in contrast to previous (2" paragraph on page), references simply to "models" or "GMPEs"). znc sentence 442. Section 6.4.4, page 6-15, Please be specific and quantitative about this procedure. For example, 3rd paragraph of section how are the rescaled ellipses defined in the case noted? (2" paragraph on page). 211* sentence 443. Section 64.4. page 6-15, Please be clear that reference is being made to the original GMPEs and We added the qualifiers throughout the report to the best of our 3'" paragraph of section to those GMPEs with the added epistemic uncertainty terms. ability. (2" paragraph on page), 3** sentence 444. Section 6.4.4, page 6-15, Please explain how the model screening was done and what models A figure was added to show example of models that were 3'" paragraph of section were removed during the screening process. removed. (2" paragraph on page), 4"' sentence 445. Section 6.4.4, page 6-15, Please explain the basis for the assumption that "The selected points They are representative of the hazard by definition, because 4th paragraph of section are assumed to be representative of their neighborhood in ground-they produce the same GM. The differences in the standard (3 paragraph on page), motion space". deviation are less than . 1 . Not sure the text has been changed Line 1 to say so. 446. Section 6.4.4, page 6-15, Please clarify whether the word "boundaries" means boundaries of the We stated what is the scale factor for 4th ellipse (it is 2) 4"' paragraph of section outer Voronoi polygons, and state the scale factor used to define the (3 paragraph on page), fourth ellipse. Line 3 447. Section 6.4.4, page 6-15, Please explain the reason for not simply using the selected point to 4th paragraph of section represent the models in a Voronoi cell. (J't paragraph on page), line4 448. Section 6.4.4, page 6-15, The meaning of the phrase "closeness in hazard space for each cell" is See response to 449. 4"' paragraph of section not clear. For example, closeness of what to what? Please consider (3'd paragraph on page), whether this sentence can be deleted and the word "therefore" deleted 4'" sentence from the following sentence 449. Section 6.4.4, page 6-15, Please explain in what sense the hazard curve for the selected model is We defined "closeness" and provided explanation on how it is 4th paragraph of section "closest" to the mean. computed (3" paragraph on page), 6'" sentence 450. Section 64.4. page 6-15, Please explain why selection of this "closest" point as a representative ol same as above 4'" paragraph of section the cell does not contradict the first sentence of the paragraph. which (3 paragraph on page), appears to say that the points on the ellipses "selected" in the previous 5th sentence paragraphs "are assumed to be representative of 1heir neighborhood." 451. Section 6.4.4. page 6-15, Please explain how to interpret the x-and y-axis scale of the Sammon's Explanation provided (in the attachment E for Rev1, and in the 4'" paragraph of section map, as was requested by many workshop participants during introduction to Appendix H for Rev.2). (3 paragraph on page), Workshops 2 and 3 and recommended by the PPRP in its comment last line letters on the workshops. 452. Section 64.4. page 6-15, The phrase "distribution of HW branches for the selected representative Done 5'h paragraph (4'h branches" is awkward. Please consider rewri1ing this phrase to improve paragraph on page), 1" its clarity. line 453. Section 6.4.4, page 6-15, Please explain why this distribu1ion of HW terms does no1 contradict the The two steps for the HW approach for DCPP are better 5th paragraph of section statement in Section 6.4.3 that "the central hanging wall branch is described in Section 6.4.3 (4'" paragraph on page). applied for the Sammon's maps." That section also notes that "later the 2"" sentence DCPP base models are assigned a random HW models[sic]," but there appears to be no mention of that addition in the intervening text. The treatment of the HW terms requires clarification. 454. Section 6.4.4, page 6-15, Please state the rationale for the assessment given in this sentence. Justification added as of why HW effects are not important for S"' paragraph of section PVNGS. (41" paragraph on page). last line 455. Section 6.4.5, page 6-15, Please explain the need to assign a weight to each selected model. Also Further text added to explain what the rationale for not assigning 1 paragraph of section, note that the sentence refers ambiguously to "representative models for equal weights is. Concept also addressed in Appendix 0 line 1 each cell." Please use the singular "model" to avoid the implication that there could be multiple models selected for a cell, unless that is the intent. 456. Section 6.4.5, page 6-15, Please indicate what data set(s) the statistics are calculated for, and The word "mean" has been dropped. Verbiage change has been 1" paragraph of section, clarify what is meant by "mean statistic" in this context (e.g., why is it applied to say "metric" throughout the section. Same verbiage 1 sentence appropriate to call the likelihood a mean statistic?). modification applied to chapters 8 and 9 for consistency 457. Section 64.5. page 6-t6, The same notation, "w", was used for the weights defining the Eqn 6.4-7 Sammon's distance metric. This is potentially confusing, especially since the term "weight" is used for both. Note also that "L is used in this equation to represent a generic statistic, but the same symbol is defined as the likelihood in the subsequent bulleted list Please make corrections to ensure that notation throughout the chapter is consistent and unambiguous. 458. Section 6.4.5, page 6-16, Please replace the typo "combing cell with "combined cell", or perhaps Done paragraph 1 on page, 2"d even better by "merged cell" to be consistent with the previous sentence. to last line 459. Section 6.4.5. Page 6-16. Please define "M" and D". Notation removed Second Paragraph on page, Last Bullet 460. Section 6 4.5 t, page 6-Please explain the basis for assuming that the cited properties of the The verbiage "Equal weights" refers to assignment of equal 17, 2"' paragraph of original GMPEs are also applicable to the constructed GMPEs. weights to the models used to generate the covariance matrix. section (1'1 paragraph on Once generated, the prior weights reflects how often page), line 6 generated ground motion models appear in a particular location. The prior weight incorporates the notion that the covariance is correct and represents the uncertainty fully. 461. 6.4.5.1, page 6-17. This sentence is imprecise about the definition of the norms referred to. Sentence deleted paragraph 2 of section as well as what space they are defined on. The sentence could be (1"1 paragraph on page), interpreted to suggest that the mean residual is an L 1 norm, which it is last sentence not, nor is it even a norm at all, nor is its absolute value (neither one is positive definite). The sentence should be rewritten to make it clear what norms it refers to, and what vector space the norms apply to. Alternatively, if the sentence is not essential to subsequent arguments, please consider deleting it 462. Section 6.4.6, General Please summarize the Tl Team's assessment of the appropriateness of The Tl Team's assessment is contained in Chapters 8 and 9. the selected models and model weights in capturing the center. body. and range of the median amplitude. If such assessments are discussed in Chapters 8 and 9, please provide references to the relevant section(s). 463. Section 6 4.6. General Please discuss the following observation: For M 7 5 and short periods An explanation has been added (PGA and T=0.2s), the ground-motion distribution at larger distance (Rx > 30 km) is broader than at shorter distances (Rx< 10 km); see, for example, Figure 2.178 of Appendix H. Please explain the cause of this behavior. Given that empirical data are sparser at shorter distances. intuitively. shouldn't the epistemic uncertainty be larger at shorter distances than at larger distances? 464. Section 6.4.6, General Please discuss the following observation: For PGA and T=0.2s, ground-An explanation has been added motion distributions at Rx=-1 and -5 exhibit a large negative skewness at M > 6 5: see for example, Fig. 2.236 of Appendix H. In contrast, the distribution based on the candidate GMPEs shows much less skewness Please explain the cause of the negative skewness and justify the appropriateness of the model distribution. Also. please discuss whether the negative skewness may yield more conservative (or less conservative) hazard in comparison to the use of a less skewed distribution (such as the one from the candidate GMPEs). 465. Section 6.4.6, page 6-17, Please correct the section reference. Done Line 1 466. Section 6.4.6, page 6-17, Please specify the section number in the statement "in the section for Done Line 5 PVNGS" 467. Section 6.4.6. 1, page 6-Please clarify what the "total weights" case represents, since it has not Done 17, 2"c paragraph in been defined at this point in the text. This expression is also used section, Lines 3 and 4 without definition in Chapter 8-please make necessary edits lo ensure claritv 468. Section 6.4.6.1, page 6-Please clarify whether reference is being made to the original empirical Done 17. 2"" paragraph in GMPEs or to the constructed virtual GMPEs. section, Lines 4 and 5 469. Section 6.4.6.1, page 6-Please justify the weights 80%110%110%, given that the plus/minus 17, 2"' paragraph in models are two limes the standard error away from the mean. section, Lines 5 470. Section 6.4.6. 1, page 6-The expression "plus/minus uncertainty model" is imprecise and Done throughout the report 17, 2"' paragraph in ambiguous. Please use a clear, unambiguous terminology for this set of section, Lines 6 and 7 models consistently throughout the chapter. 471. Section 6.4.6.1, page 6-The residual-based weighting case for the NGA dataset is indicated as We added the "usually" qualifier, and added few examples 18. 3rd paragraph of being the blue curve in Figure 6.4.6-1. That curve appears to define a rather than only one (from Appendix H). Typo corrected. section ( 1 '1 paragraph on relatively narrow distribution (probably the second narrowest after the page), 1"' 2 sentences likelihood case for the EU dataset), apparently narrower than that of the black curve representing the GMPEs. But the text here says the opposite ("using the residual-based weights yields to[sic) ground motion distribution broader than the one associated to the candidate GMPEs". Furthermore. the prior-based case (brown curve) appears to be one of the broadest. yet the text says . ._ .. prior-based weights lead[s) to narrow distributions." Please provide clarification as to what the conclusion actually is, and then further clarify whether the stated conclusion applies to the majority of scenarios examined in Appendix H (also note the typo, "yields to instead of "yields a"). 472. Section 6.4.6.1, page 6-The total weighted distribution of the simulated weighted GMPEs is very 18. 3'd paragraph of similar to the distribution for the GMPEs themselves. Please indicate if section ( 1 '1 paragraph on this is true in general and if the weights were chosen to closely match page), 3'" sentence the GMPE distribution on average. 473. Section 6.4.6.2, Page 6-Please clarify if the term "quantile" is the same as the term percentile" The terms are the same, but have not been unified in the report 18. 1st Paragraph of used elsewhere in the report and appendices and, if it is, please Section, 2nd Line consider consistently using only one of these terms in order to avoid confusion. 474. Section 6.4.6.2, page 6-The phrase "Widthlrange" is vague (e.g .. is there a distinction between The two terms have been separated. 18. 1st paragraph, last line width and range, and if so what is it?). Please use language that is precise about what specific attribute(s) will be compared. 475. Section 6.4.6.2, Page 6-Please explain the significance of the comparisons shown in Figures A sentence indicating that the distributions are similar has been 18. 2nd Paragraph of 6.4.6-2 through 6 4 6-4. It appears that the two distributions are added Section generally similar. 476. Section 6.4.6.3, Page 6-Please explain the significance of the quantile ratio plots shown in It is a way to summarize width of distribution. Clarifying text was 18. 2nd Paragraph of Figure 6.4.6-5. added. Section 477. Section 6.4.6.4, Page 6-Please reconcile the "broader distribution" shown in Figures 6 4 6-6 and Partially answered 19, 2nd Paragraph of 6.4.6-7 with the previous figures that show similar 0.05, 0.5, and 0.95 Section, 4th Sentence auantiles for the simulated models and the GMPEs. 478. Section 6 5. 1. General There is insufficient discussion of directivity models for the dip-slip The model applies to both strike slip and dip slip ruptures. earthquake sources. Please enhance the text to address this deficiency. Directivity has no hazard significance (As shown in Chapter 14). so we feel that the discussions are adeauate 479. Section 6.5.1, Page 6-19, Please replace "Somerville et al. (1999)" with "Somerville el al. (1997)". Done 1st Paragraph of Section, 2nd Line 480. Section 6 5.1. Page 6-19. There is no mention of magnitude in Figure 6.5.1-1, although it can be Done 3rd Paragraph of Section. presumed that the different rupture lengths shown in this figure 2nd Line represent different magnitudes. Please include the magnitude in addition to the rupture length in Figure 6. 5.1-1 for com ple1eness and lo tie the figure to the MS magnitude mentioned in this sentence. 481. Section 6 5. 1. Page 6-20. Please also reference Spudich and others (2014; Earthquake Spectra, Verbiage inserted into the main text. References polished 4*h Paragraph of section vol 3., no. 3, page 1199-1221) and Spudich and Chiou (2013; Chapter 5 (2"d on page), First of PEE R's directivity working group report). since both gave an in-depth Sentence discussion on the issue of centering. 482. Section 6 5. 1. Page 6-20. The NGA-West2 developers had originally concluded that the Chiou and Clarification provided 4'" Paragraph of section Youngs (2014) directivity model could not be used with other GMPEs (2"d on page), 2"" because of the centering issue. Please explain the basis or provide a sentence reference for assuming that the CY14 directivity model can now be used with other GMPEs. 483. Section 6 5.1. Page 6-20. Chiou and Youngs (2014) addressed the effect of directivity on only Explanation added 4'" Paragraph of section median amplitude. Please explain the basis for concluding that there is (2"d on page), line 6 variation of sigma along strike, and explain what sigma is referred being referred to. 484. Section 6 5.1. Page 6-20. Please explain the need for simplifying the application of the directivity We have to simplify to speed up the calculation so we do not 5"' Paragraph of section model. Also ensure that Watson-Lamprey (2014) (still listed as being in integrate over the hypocenter distribution in the hazard 3'" on page), Line 1 preparation) will be published (or at least be in press) prior to finalizing computations. The issue of the draft report timeline for the PSHA report if the results of the study are to be used by the Tl Team publication is out of our control, but we have included what was as part of their evaluation. used so the documentation is complete. We are using the draft report and the SSHAC guideline allows us to use unpublished results. This issue is further addressed in Rev.2 report. 485. Section 6.5.1, Page 6-20, Please provide a definition and a brief description of the variable "DPP." A reference is already provided. No further actions needed S"' Paragraph of section 3'd on page), Line 6 486. Section 6.5.1, Page 6-20, Please indicate if Attachment C passes peer review or the Tl Team's The Tl Team reviewed the resulting model and its applicability to 6"' Paragraph of section evaluation. Please describe the Tl Team's basis for accepting the DCPP conditions. The PEER report is in draft stage. but it was 4'" on page). Line 1 simplified models in Attachment C for use in the hazard calculation. not our job to edit the report for completeness 487. Section 6 5.1. Page 6-20. Please clarify who developed the parametric model, and indicate We used two different hypocenters along strike but only a single 7"' Paragraph of section whether rupture depth (which is not mentioned here) was considered as model for hypocenter depth. For the DCPP application, 5"' on page). 1** 2 a parameter and found to be insignificant. directivity effects due to rupture depth are not important. sentences Sensitivity analysis in Chapter 14 shows no significant sensitivity to the directivity. therefore we did not develop more models for depth distribution. No change in the text. This issue is further addressed in Rev.2 report. 488. Section 6.5.1, page 6-20, If the phrase " ... at the ends of the large strike-slip faults." is meant to Clarification added 8"' paragraph of section indicate "at the ends of large strike-slip ruptures, please make that (61" on page), 2"d to last correction. In any case, please clarify the meaning of the phrase line. 489. Section 6.5.1, page 6-20, To avoid potential misunderstanding, please revise the text to note that Done 8111 paragraph of section this statement refers to the case of treating the hypocenter position as (61" on page), line 5 random along the fault, not the case where the hypocenter is deterministically specified. 490. Section 6.5.2, Page 6-21, The first sentence is ambiguous (e.g., "a small impact" could be Done First Paragraph interpreted to mean a significant one), and the Workshop 3 reference is incorrect (Section 4 does not exist). In any case, please cite the Chapter 14 sensitivity studies here to provide an adequate technical justification for the simplified treatment of directivity. Once the Chapter 14 sensitivities are referenced, consider whether also citing the workshop proceedings is redundant. 491. Section 6.5.2, Page 6-21, Please provide a discussion of other directivity models published since First Paragraph, Last 2008, including why Chiou and Youngs was selected but not alternative Sentence models 492. Section 6 6.1. Page 6-21. In order to avoid confusion, please reserve the term "proponent models" Agree. Clarification and consistent nomenclature added. General and "proponent methods" to refer to models or methods proposed by Proponent Experts as defined in the SSHAC guidelines. Please use a different name to refer to models proposed by the Tl T earn here and elsewhere throughout the report and appendices. 493. Section 6.6.1, Page 6-21, Please define what is meant by "path terms" the first time it is used, so Done 2nd Paragraph of the reader need not have to read Appendix L to understand what the Section, 1st Line term means. 494. Section 6.6.1, Page 6-21, Please provide a reference to the specific report sections, tables and/or Done 3rd Paragraph, Line 3 figures where the description is provided. 495. Section 6.6.2, Page 6-2t. Please clarify what the units (and sign) of the path term mean, and The units are log ground motions. A possible explanation is that First Paragraph, Line 1 explain whether the large negative path term (about -0.5) for regions 2 those ray paths travel a zone with higher heat flow. and 3 appears reasonable on geological and geophysical grounds, such as known differences in crustal structure. Also. please comment on the size of the path term compared to those estimated for other regions by previous studies. 496. Section 6.6.2, Page 6-21, Please comment as to whether additional epistemic uncertainty in the The uncertainty reflects the sample size and we also have First Paragraph, Line 1 path term is warranted, given that a sparse dataset was used in its considered the additional uncertainty related to the large M estimation. scaling 497. Section 6. 7.1, Page 6-22, Please define what is meant by "R here. Definition added First Paragraph, Line 5 498. Section 6 7. t. Page 6-22. The term "PSA" is used on line 7, and "Sa" is used in Eq. (6.7-1 ). Please Consistent term is used throughout the report First Paragraph, Line 7 select and use a consistent term for this parameter. and Eqn 6.7-1 499. Section 6. 7.1, Page 6-22, Please provide a short description of the motivation behind Method 1. Done First Paragraph, Line 10 500. Section 6. 7.1, Page 6-22, Please consider revising the phrase '"single representative rupture" so Clarification added First Paragraph, Last that it will not be misconstrued as a new rupture geometry modified from Sentence the rupture geometry specified in the SSC model. For example, doesn't the method create a single representative set of predictor variables? 501. Section 6.7.1, Page 6-22, Please define the term 'WidthDD" here and include it in the list of terms. substituted with "Down-dip width" Second Paragraph, First Sentence 502. Section 6 7. 1. Page 6-22. Please check whether the second sentence is redundant-given that it Done Second Paragraph appears to just repeat the content of the first sentence-and revise if appropriate. 503. Section 6 7.1. Page 6-23. Please define the distance metric "R", and consider changing the phrase Done 3'" Paragraph of section "based on distance" to something like '"based on inverse-squared (2"" paragraph on page), distance". Line 3 504. Section 6.7.2, General There are empirical ground-motion data from historical earthquakes that Reference to Somerville et al (2011) presentation added to the exhibited complex rupture or splay fault rupture, including those in the text. NGA-West2 database and the 2011 Fukushima-Hamadori, Japan. earthquake. Please indicate whether these empirical data were used by the Tl Team to evaluate the four proponent methods. If so, please describe the main results of the evaluations; if not, please explain why not. 505. Section 6.7.2.1, Page 6-Please explain what is meant by the term '"main rupture'" or rewrite the We use the term "primary" and '"secondary rupture 23, 1st Paragraph of section in a form that does not depend upon making that distinction. Section, Last Line 506. Section 6. 7.2.1, page 6-Please rewrite this sentence to improve its syntax and clarity. Done 23. paragraph 3 of section, t" sentence 507. Section 6 7.2. t, Page 6-Please brieffy summarize the discussion from Appendix J explaining the We analyze only representative cases, not covering the full 23. Second Paragraph. extent to which these complex scenarios cover the full range present in range of scenarios in the SSC model Line 2 the SSC model. Also please provide specific (subsection number) reference(s) to that discussion to justify the sufficiency of these scenarios. Also, Figure 6.7.2-1 does not provide a clear annotation of the associated geometry for the main rupture. the combined rupture, and the location of the site mentioned on Line 2. Please revise the text and the figure to correct these deficiencies. 508. Section 6.7.2.1, page 6-Please explain more clearly and precisely what the term Done 23, 3*d paragraph of "complex/simple LN (ratios) means. Also, please use conventional section, lines 3-5 notation such as ln(x) for the natural log of x (here and elsewhere in the report). 509. Section 6.7.2.2, Page 6-Please brieffy summarize the discussion from Appendix J explaining that see answer to 507 24, Second Paragraph these splay scenarios cover the full range present in the SSC model. Also please provide specific (subsection number) reference(s) to that discussion to justify the sufficiency of these scenarios. 510. Section 6.7.2.2, page 6-Please rewrite this sentence to clarify its meaning. sentence rewritten 24. paragraph 3 of section, 1*1 sentence 511. Section 6.7.2.2, page 6-The text states that "The site is assumed to be located near the splay Parenthetical comment removed 24. 2"" paragraph of rupture (otherwise the effect of the splay can be ignored)." If in the upper section, last line right diagram of Figure 6.7.2-1 the site were moved from "near the splay" to near the part of the main fault southeast of the junction. what would be different? Please explain the origin of the asymmetry; that is, please explain why the splay can be ignored if the site is near the main fault (the part of the main fault that is SE of the junction, just like the splay is), but the SE part of the main fault cannot be ignored if the site is near the splay. Alternatively, consider deleting the parenthetical comment if it is irrelevant to the ground motion model 512. Section 6 8. Page 6-25, Please provide a more complete description of the Abrahamson (2000) Done 4th Reference reference (e.g., dates and location of the conference, paper number, proceedings pages, etc.) 513. Section 6 8. Page 6-25, Please update the Abrahamson et al. (2014) reference with page Reference fixed 6th Reference numbers from the published manuscript. 514. Section 6.8. Page 6-25, Please replace the date "2013" with "2014a" in the Akkar et al. (2013) Reference fixed 7th Reference reference to renect the actual date of publication. Note that the "a" should be added because the referenced erratum was published in the same year. 515. Section 6.8, Page 6-25, Please update the Akkar et al. (2014) reference with the volume and Reference fixed 8th Reference page numbers of the published manuscript. Please also replace the date "2014" with "2014b" to renect the fact that the original manuscript was published in the same year as the erratum. 516. Section 6.8, Page 6-25, Please update the Al Atik and Youngs (2014) reference to include the Reference fixed 9th Reference page numbers of the published manuscript. 517. Section 6 8. Page 6-25, Please replace the date "2013" with "2014a" in the Bindi et al (2013) Reference fixed 11th Reference reference to renect the date the manuscript was published and the fact that the erratum was published in the same year. 518. Section 6.8, Page 6-25, Please replace the date "2014" with "2014a in the Bindi et al. (2014) Reference fixed 12th Reference reference to renect the fact that the original manuscript was published in the same year. 519. Section 6.8, Page 6-25, Please update the reference Bommer et al. (2014) to include volume Reference fixed (it is now Atkinson et al. 2014) 13th Reference and page numbers of the published manuscript, if available. 520. Section 6.8, Page 6-25, Please update the Boore et al. (2014) reference to include the page Reference fixed 15th Reference numbers of the published manuscript. 521. Section 6.8. Page 6-26, Please update the Campbell and Bozorgnia (2014) reference to include Reference fixed 1st Reference the page numbers of the published manuscript 522. Section 6 8. Page 6-26, Please provide the organization that the Chiou et al. (2000) report was 2nd Reference submitted to 523. Section 6 8. Page 6-26, Please update the Chiou and Youngs (2014) reference to include the Reference fixed 4th Reference page numbers of the published manuscript. 524. Section 6.8, Page 6-26, The Graizer (2014) reference is not cited in the text. Please either cite The model is referred in various occasions. Proper reference 7th Reference this reference or remove it from the list of references. inserted 525. Section 6 8. Page 6-26, The Graves and Pitarka (2014) reference is not cited in the text, but is References to the FFS methods GP. SDSU and EXSIM are 8th Reference probably the reference to the acronym "G&P (also cited as "GP") used provided. to identify one of the simulation methods in some of the figure captions. Please cite this reference the first time that the acronym "G&P" is used and use a consistent acronym for this reference. 526. Section 6.8, Page 6-26, Please update the Idriss (2014) reference to include the page numbers Reference fixed 9th Reference of the published manuscript. 527. Section 6 8. Page 6-26, Please replace the date "2014a" with "2014" in the Kashida et al (2014) Reference fixed 12th Reference reference. 528. Section 6.8, Page 6-26, The Olsen and Takedatsu (2014) reference is not cited in the text. but is See answer to 525 14th Reference probably the reference to the acronym "SDSU" used to identify one of the simulation methods in some of the figure captions. Please cite this reference the first time the acronym "SDSU" is used. 529. Section 6 8. Page 6-26, Please provide a more complete description of the Somerville and Done to the best of ability 17th Reference Abrahamson (1995) reference (i.e .. report number, organization, etc.). 530. Section 6.8, Page 6-27, Please update the Watson-Lamprey (2014) reference with the report The draft PEER report is associated to the 2015 date (and not 2nd Reference number, publisher, etc .* if available. If the report is not published or in 2014 as correctly noted by the PPRP). press al the lime the SWUS report is finalized, any reference to the We disagree that the PEER report should be considered a Tl PEER report should be removed from the report and characterized as Team's product. but the Tl Team's evaluation of the candidate an analysis performed for the Tl Team and included as an appendix. directivity model is part of the SWUS report. 531. Table 6.6-t, Page 6-29 The values given in Table 6. 6-1 do not appear to be consistent with the The table is correct: Regions 2 and 3 are combined in the table proposed models shown in Figure 6.6.1-2. Please explain why this is the case, or if in error. correct the table or figure. 532. Table 6 7-1. Page 6-30 Please define the term "DDWidth" the first time it is used Changed to Down-dip Width 533. Figure 6.2.1-1, page 6-31 In the explanation, the acronym "ld14" is used, whereas in the text, ii is Abbreviations are now consistent given as "114". Please choose one and be consistent. This same comment applies to the corresponding figures. 534. Figure 6.2.1-2, Page 6-32 Please explain what the term "ZH06 = ZL 11" means in the legend and Explanation on ZH06 = ZL 11 is provided in caption. correct "ZH06" to "Z06 and "ASB 13 to "ASB 14" to be consistent with Abbreviations are consistent. the terminology used in the text. 535. Figure 6.2.3-1, page 6-34 The caption refers to periods al 0.2, 0.5, 1.0 and 2.0 seconds, but is not Period labels added. Consistent abbreviation provided. clear as to which panel is which. Please label the individual panels for clarity. Please also remove mention of a specific period in the legend, since period varies from panel lo panel. Also correct the legend to refer to the NGA-West2 models by the acronyms used in the text (e.g., "ASK14"). 536. Figure 6.2.3-2, Page 6-Please explain the meaning of the phrase "over frequency" in the figure 35, and Figure 6.2.3-3, caption. Page 6-36 537. Figure 6.3.1-2, page 6-38 The solid (5 km) and dashed (10 km) curves should be belier explained Consistent abbreviation provided. in the caption. Also, please refer to the GMPEs in the legend by the acronyms used in the text (i e., "ASK14" instead of "ASK") 538. Figure 6.3.3-1, page 6-39 Please add an explanation of the black curves to the caption. Please Done also define the terms EXSIM, G&P. and SDSU and provide citations to references in the list of references. The apparent references to these models in the list of references are incomplete and should be updated to "in press or published when possible. Please note that the reference to EXSIM is missing from the list of references. 539. Figure 6.4.3-1, page 6-40 Please provide in the caption the predictor variable values for which the See answer to 393. Labels and scenario clarified. Description of plot was generated. Also please consider explaining more explicitly that red curves enhanced. the red curves represent the distribution of the median (mean of natural log) for each GMPE based on the Al-Atik and Youngs (2014) analysis of epistemic uncertainty. 540. Figure 6.4.3-2, page 6-40 Please explain in the caption how to distinguish the Model A and Model Done. B samples, and also give the meaning of the solid dots and their colors. Please also define the axis labels. The plot of "sampled models" is for 15,000 samples, but 2,000 samples were used. Please replace this plot with one for 2,000 samples to better represent what was used in the evaluation. 541. Figure 6.4.4-1, page 6-41 Please correct the caption to read "mean between-event residuals," add Done an explanation of the black dots, and identify the "contours" as the gray lines in the plot. 542. Figures 6.4.6-2, 3 and 4, Please add explanatory text to the caption indicating that the solid lines Done pages 6-43, 6-44, and 6-are the 0.5 quantiles, whereas the dashed lines represent the 0.05 and 45 0.95 quantiles 543. Figures 6.4.6-2, 3, 4 and Please explain the meaning of the term "total weights" in the figure Done 5, pages 6-43, 6-44, and caption. 6-45 544. Figure 6.5.1-5, Page 6-47 Please replace the date "1999" with "1997" in the Somerville el al. Done (t999) reference in the figure caption. 545. Figure 6.6.1-1, page 6-49 Please correct the mislabeling of the figure in its caption. Also, in the Done caption, please specify which colors are referred to for the "colored lines" that represent faults, as there are also colored lines that separate regions. Also please add the location of PVNGS to the map. Note also that 5 earthquakes appear to be located in Region 1. whereas the text seems to indicate that there are 3 (first line on Page 6-22). Please review and revise this caption as needed 546. Figure 6.6.1-2, page 6-50 Please correct the mislabeling of the figure in its caption, and provide Done the units for the oath terms aiven in the olots. 547. Figure 6.7.2-2, page 6-52 Please label the vertical axis. The simulation model acronyms in the GP is used throughout the report. The figures with axis label are figure caption have not been defined in the text at this point. Please available in Appendix J and are provided in Chapter 6 in a make sure they are defined and cited prior to being used the first time consistent manner. and that they are included in the list of references. Nole also that the acronym "GP" is referred to as "G&P" elsewhere in the chapter. Please use a consistent acronym for "G&P" throughout the report and appendices. 548. Figure 6.7.2-2,3,4, pages Captions for these figures are inadequate. Please write captions that Done 6-52, 6-53, and 6-54 indicate the scenarios for which results are depicted and, in the case of Figure 6.7.2-3, indicate what the respective colors represent. Also label and provide units for they axis in Figure 6.7.2-4, and check that all references to the simulation models use acronyms that have previously been defined and are consistent with usage in the rest of the report. CHAPTER 8 Median GMC Models: DCPP Sources 549. Section 8.1, page 8-1, Please consider writing a more precise statement of the procedure. Clarification added numbered item 4 For example, would ii be better described as sampling from the multivariate normal distribution defined by the coefficient covariance matrix? 550. Section 8.1, page 8-1, This statement is impossible to parse. Please consider rewriting to Paragraph rewritten to improve clarity item 5 improve its clarity. One option to consider is breaking it into 3 items, the first stating the formation of high-dimensional vectors. each representing the ground motion predictions of a given model for a representative range of predictor variables, the second stating that a metric is defined on that high-dimensional space based on the differences in hazard level between model pairs. and the third staling that the vectors are represented in two dimensions via a (nearly) metric-preserving mapping procedure by means of a Sarnrnon's map. If the term "deaggregation" is retained in the revision of this passage, please indicate what it means in this context (i.e .. what was deaggregated and for what set of parameters). 551. Section 8.1, page 8-1, Please specify that it is the two-dimensional space (i.e., after the Done item6 Sammon's mapping procedure is applied) that is discretized. 552. Section 8.2, page 8-1, The statement that weights associated with statistical sampling are Done 1" paragrafh of shown in green seems a little odd, since none of the weights in the section, 2° sentence figure are actually shown in green (and in fact there are no green weights in any of the figures in the entire chapter). Please consider revising this and other related statements to avoid confusion. 553. Section 8.2, page 8-1, Weights of the base models are not provided on Figure 8.2-1. Done 1** paragraph of Please provide the missing weights and indicate the nature of these section, 2"d sentence weights (i.e. are they subjective weights or weights associated with statistical sampling). 554. Section 8.2, Page 8-The definition of "base model is given after it is first mentioned on Done 1, Second Paragraph Line 1 of Page 8-1 . Please move this definition to where it was first of section. Line 2 mentioned. 555. Section 8.2, Page 8-2, 4m line on page Please explain how a HW model was assigned to each base model. Done 556. Section 8.2, Page 8-Please clarify if the hazard for spectral periods longer than 3 sec are Clarification added 2, 3'd of part of the deliverable and, if yes, please provide a reference to the section (2" on page). sections where median models for these long period spectra are Line 2 evaluated and integrated into logic trees. 557. Section 8.2, Page 8-Please summarize the meaning of the different branches in the logic Done. Also. we changed colors to branches (all red entries) 2, 3"' of tree in Figure 8.2-2, similarly lo what was done for Figure 8.2-1. section (2° on page). 2nd Sentence 558. Section 8.2, Page 8-The discussion in Section 8.3 suggests that the Tl Team's focus is Clarification added 2, 3'0 Paragraph of on capturing the CBR of median-amplitude predictions. Please section (2" on page). provide text to clarify that "median ground motion models" is a Last Sentence shorthand for "median amplitude predicted by alternative GMPEs." 559. Section 8.3, Page 8-Please clarify whether the comment on the Rjb-based formulation is The problem is for both the GMPEs and the common-form 2, First Paragraph of directed toward the GMPEs (such as BSSA14) or toward the choice models section, Line 4 of the distance metric used in the common-form models. 560. Section 8.3, Page 8-Please specify the (lower) bound of the HW effect and how "being 2, First Paragraph of log-normally distributed" is unable to satisfy such a bound section, Line 6 561. Section 8.3, Page 8-Please refer to the specific branch in the Figure 8.2-1 logic tree Done 2, 1st Paragraph of Section, 4'" Sentence when describing weights. 562. Section 8.41, Page Please revise the text to be specific about the quantity to which the Done 8-2, 1 *1 Paragraph of term "range" refers. For example, is it the median amplitude section, First Line predicted by the GMPEs or the GMPEs themselves? 563. Section 8.4.1, Page The terms "common-form models" and "candidate GMPEs" are Consistent terminology applied throughout the report 8-2, 1st Paragraph of referred to by different names throughout the report and appendices. Section, 1st Sentence Please define a common set of terms for these models and use them consistently throughout the report and appendices and include them in the list of terms. 564. Section 8.4 1, Page The statistical uncertainty analyzed and parametrized by Al-Atik and Justification and discussion added 8-2, 1 Paragraph of Youngs (2014) was for the NGA-West2 GMPEs and associated section, Lines 4 and 5 datasets. Please comment on whether their results were also applied to non-NGA-West2 GMPEs and, if so, please justify that decision, given that a non-NGA GMPE may use a dataset different from those used by NGA-West2 GMPEs. 565. Section 8.4.1, Page Please revise the text to make it clear that the **+-2 sigma range" is Done 8-3, 2"d Paragraph of relative to the original candidate GMPEs. section (1'1 on page), Line 2 566. Section 8.4.1, Page Please reference the relevant sections of the report and/or Done 8-3, 2"0 Paragraph of appendices where the process of reducing the range in the common-section (t'1 on page). form models is reduced based on comparison with ground-motion 2"c sentence data. 567. Section 8.4 1, page 8-Please consider rewording this paragraph to indicate that the check Done 3, 2"" paragraph of is done to determine whether the resulting reduced range (not the section (1'1 on page), method) is appropriately wide. last sentence 568. Section 8.4 1, Page Please explain the phrase "weighted standard deviation between Clarifications provided 8-3, 4'" Paragraph of ground motions predicted by two different models ... **, and explain section (3" on page), (or provide a reference for) how it can be approximated by the Third Line distance between two points on a Sammon's map. 569. Section 8.41, Page Please indicate what the term "deaggregation means in this context A plot with the weights has been added to Chapter 6 8-3, 4'" Paragraph of (i.e .* what was deaggregated and for what set of parameters). section (3'* on page), 5'" line 570. Section 8.4.1, Page It appears that only seven red dots are plotted on Figures 8.4-1 and The plots are correct. we realize it is hard to see the dots but 8-3, S'" Paragraph of Figure 8.4-2. Please check and correct the text or figures as needed. they are there. section (41" on page), Line 2 571. Section 8.4.1, Page Please consider adding, parenthetically, a brief description of the Done 8-3, 61" Paragraph of NGAW2oc: database. section (51" on page). 4'h line 572. Section 8.4. 1, Page In setting the regions from which GMPEs are selected based on the Clarification added 8-3, 61" Paragraph of mean residual, please comment if the use of a horizon1al ellipse is section (5'" on page). compatible to the roughly 45-degree inclined pattern of the mean Last Sentence residuals. 573. Section 8.4.1, Page For the upper left plot, please label the contours of 1, 0.3, 0, -0.3, The contours for these values are now clearly marked 8-3, 61" Paragraph of and-1. (Rev.2) section (51" on page). Last Sentence. Figures 8.4-1 and 8.4-? 574. Section 8.4. 1, Page Please comment on the causes of the numerous small patches Done 8-3, 61" Paragraph of inside the horizontal ellipse. section (51" on page). Last Sentence. Figures 8.4-1 and 8.4-2 575. Section 8.4. 1, Page Please explain what "likelihood" is shown in the figures (i.e., the Clarification added 8-4, 91" Paragraph of likelihood with respect to what). section (2"" on page), 1" line 576. Section 8.4.1, Page Please explain why a fixed sigma value of 0.65 was used and what Clarification added 8-4, g1" Paragraph of impact it has on the results. Please also indicate whether "sigma" in section (2"" on page). this case is the between-event. within-event, or total standard 211* line deviation. 577. Section 8.4.1, Page Please explain the significance of a relatively low versus a relative Discussions provided 8-4, gt* Paragraph of high likelihood. section (2"" on page). 4'h line 578. Section 8.4.1, Page Please add additional contour levels to Figures 8.4-1 and 8.4-2 to Not possible at this time 8-4, 91" Paragraph of help show the likelihood value of each GMPE. section (2°d on page). Line 5 579. Section 8.41, Page In this section. the utility of using both the mean residual and the Clarifying text was added 8-4, 111"' (last) likelihood in setting the ranges was discussed. Please give a clear Paragraph of section and explicit summary of the roles played by each one in setting the final range. The boundaries shown in Figures 8.4-1 and 8.4-2 seem to suggest an unimportant role of the likelihood. 580. Section 8.4 1, Page There seems to be a large overlap in information and discussions Paragraphs consolidated 8-4, 11 u. (last) between this paragraph and the sixth paragraph on Page 8-3 (7'" Paragraph of section paragraph of Section 8.4.1 ). Please consolidate these two paragraphs where appropriate. 581. Section 8.4. 1, page 8-Please replace "epistemic" with "epistemic uncertainties. Please Done 4, 11th (last) also indicate the number of standard deviations used to represent paragraph of section, those uncertainties in the cited figure. line 3 582. Section 8.4. 1, page 8-Please explain why an extrapolation of the candidate GMPEs is Done 4, 11th (last) found in some cases and not in others. paragraph of section, last sentence 583. Section 8.4.2, Page Please be more specific about the parameter that is being referred Done 8-4, First Paragraph to of section, Line 2 584. Section 8.4.2, Page Please give a reference to where a summary of the datasets used in Done 8-4, 2"d Paragraph of this section is provided. section, Line 2 585. Section 8.4.2, Page Please provide a figure similar to Figure 8.4-4 for the simulated Done 8-5, 2"d paragraph of ground-motion data. section (1" on page), 1** line on page 586. Section 8.4.2, Page Please provide references to the sections where such definitions are Done 8-5, 3'd Paragraph of given. section (2"" on page). Lines 1and2 587. Section 8.4.2, Page Please provide the technical basis for the Tl Team's selection of the Done 8-5, 3'd Paragraph of (60, 40) mixing between the residual-based and likelihood-based section (2"d on page), weights. Line 4 588. Section 8.4.2, Page Please explain how the "judgments by the GMPE developers" are Done 8-5, 5'" Paragraph of transmitted and maintained by the selected GMPEs. section (41" on page), Item 3, Line 1 589. Section 8.4.2, Page The concern of non-independent model development has been Done both here and in Chapter 9 8-5, 61" Paragraph of brought up numerous times in this report. In this section, it is used as section (5'" on page), a critical factor in the Tl Team's evaluation of weights assigned to 1" sentence GMPEs. It is thus both helpful and important to have a clear discussion of this concern. including its causes, the magnitude-distance ranges where it is a prevalent issue, and an assessment of the extent of the resulting "redundancy." Please provide such a discussion, either here or in Chapter 6. 590. Section 8.4.2, Page Please indicate what actual weights the decision of a "3 to 1 Done 8-5, last paragraph on preference leads to for the empirical and the simulated data sets. page, last sentence 59t. Section 8.4.2, page 8-Please replace "cumulative density function" with "cumulative Done 6, (last) paragraph distribution function." in section, line 2 592. Section 8.4.2, Page Please clarify the meaning of "range" as used in this sentence. The Done 8-6, 7'" (last) likelihood approach seems to render a narrower "shape" (body) than Paragraph in section, other approaches but its range (the difference between the largest Line 5 and the smallest value) is comparable to others. Please be precise when the concept of the center and body of a distribution is invoked. 593. Section 8.4.2, Page Please provide the criteria against which reasonableness is Done 8-6, 7'" (last) assessed. Paragraph in section, Line 7 594. Section 8.4.2, Page Please clarify whether this is generally the case for different Done 8-6, 7'" (last) scenarios and spectral periods. paragraph in section, 2"" to last Sentence 595. Section 8.4.3, page 8-Please clarify that the CDF associated with the selected weights (not Done 6, 1"' paragraph of the weights themselves) has the property indicated Also indicate section, line 4 that "median" refers to CDF=0.5 on Figures 8.4-5 and 8.4-6. 596. Section 8.4 3, page 8-Please check the values given here for the offset of the medians in Done 6, 1" paragraph of Figure 8.4-5. For example, are the red (selected weights) and brown section, lines 4 & 5 (GMPEs) 50'h percentile values offset by about 0.1 natural log units (rather than 0 05 as stated), and is the purple (simulations) curve offset from the red by at least 0.15 log units (not 0.1 as stated)? 597. Section 8.4.3, Page Please clarify what is meant by the phrase "slope of the CDF" and Done 8-6, 1 "1 Paragraph of how this slope defines the body of the distribution. section, Last Sentence 598. Section 8.4.3, Page Please explain why curves representing the statistical uncertainties Reply to first part: Hazard curves for candidate GMPES with 8-6, 3'" Paragraph of of each original GMPE are not included in these plots (whereas they additional epistemic uncertainty are added to separate plot. section, Line 2 are included in previous figures for evaluation of the CBR of the ground motion distribution), and explain the odd shape of the 0.05 quantile curve for M7.5 in Figure 8.4-7. 599. Section 8.4.3, Page Please explain why the 50% value does not always track the median Explanation added 8-6, 3'° Paragraph of of the predictions of the original GMPE (e.g .. see the upper right plot section, Line 2 in Figure 8.4-9). 600. Section 8.4.3, page 8-In Figure 8.4-7, it appears that the selected models do not quite Explanation added 6, 3'" paragraph of envelope the original GMPEs for M 7.5 (e.g., at distance Rx<2), as section, 3'" sentence categorically claimed in the text. In fact, the figure gives the impression that M 7.5 is at least as much as exception (to the models enveloping the GMPEs) as is M 5.5, and the text does note the latter exception. Irrespective of whether the exceptions are significant, the apparent inconsistency between the text and the figure is confusing. Please clarify. 60t. Section 8.4.3, page 8-Although the reason for the selected M5.5 models not enveloping Explanation added 6, 3r<1 paragraph of the original GMPEs is given, please also explain why it is acceptable section, 4'" sentence to allow this underestimate of the range in GMPEs in the model. 602. Section 8.4 3, page 8-Please state the rationale for the Tl Team judgment cited here. Done 6, 3'" parawaph of section, 2" to last line on page 603. Section 8.4.3, Page Curves from the models with additional epistemic uncertainty are not The curves are included 8-7, 3'" Paragraph of shown in Figure 8.4-10. Please correct this oversight. section (1" on page), Line 1 604. Section 8.4.3, page 8-The phrase "all of the models are not enveloped" reads as if none of Sentence rewritten 7, 3'" of the models are enveloped. Please rephrase to state" ... not all of the section (1' on page), models are enveloped due to the sharp ... " last 2 lines 605. Section 8.4 3, page 8-Please indicate what "lower and "higher" center for the simulations Clarification added 7, 6"' of is with respect to (e.g., the GMPEs, the Tl Team's weighted average section (4' on page). model, etc), and whether it refers to ground-motion amplitude or 3*d sentence probability. 606. Section 8.4.3, page 8-Please explain the meaning of "the upper tail of the distribution in Clarification added 7, 6'" parawaph of section (41' on page). this context, and consider whether it is appropriate terminology to refer to the "center and body" of the upper tail distribution, or whether last sentence this may be an oxymoron. In any case, please define clearly what is meant in this context. 607. Section 8.4 3, Page Please improve the text so it is clear and easier to understand. The Done 8-7, ?'to Paragraph of revision should also indicate that CDF=0.5 refers to the median of section (5'" on page). the distribution and state what specific "statistics" are computed. Lines 1 to 5: 608. Section 8.4.3, Page Please explain what the "zero residual" is with respect to. Done 8-7, 7'" Paragraph of section (51" on page). Line 8 609. Section 8.4.3, page 8-Please note that the phrase "distance scaling" is repeated. Duplicate verbiage removed 8, of section (1' on page), line 2 610. Section 8.4.3, Page Please clarify which curve in Figure 8 4-17 corresponds to the mean Clarification was added in the caption, following the example 8-8, 11 paragraph of hazard. Also, please revise the categorical statement "larger than the in Figure 8.4-18 section (41" on page). hazard from GMPEs" (which appears to be true atlow probability but Second Sentence not necessarily at high probability). 611. Section 8.4.3, Page The original GMPEs with statistical uncertainties are an essential See reply to 598 8-8, 11 tt. paragraph of part of the overall epistemic uncertainty in the median motion, and section (41" on page). they are used extensively by the Tl Team in Section 8.4 to set the Third Sentence ranges from which representative GMPEs are selected. Given this, please justify why the hazard based on these GMPEs is not included in the checking exercise. 612. Section 8.4 3, Page The average hazard from the GMPEs is not shown in Figure 8.4-17. We disagree with this request 8-8, 11 *** paragraph of Please revise this statement to refer to "hazard" instead of "mean section (4'" on page), hazard". 5'" line 613. Section 8.4 3, page 8-Here the acronym "ID14" is used. whereas in Chapter 6, it was "114". Consistent acronyms are used. Clarification added 8, 11'" paragraph of In many of the figures, it is denoted "ld14." Please choose one section (4'" on page). acronym and be consistent throughout the text and figures. Also note line 7 that there is no separate GMPE for ZL 11 (it represents a method for characterizing magnitude saturation). Please describe how ZL 11 was used to create a GMPE where the empirical GMPEs are first discussed and assign it a unique acronym to use here and elsewhere throughout the report and appendices. 614. Section 8.5, page 8-9, This section seems to imply that HW effects are not involved in the See reply to 598 general model generation and representative model selection of Chapter 6. It is not clear how this is consistent with the second to last paragraph of Section 6.4.4. where HW effects appear to have been assigned by some form of sampling during the selection of representative models. Please clarify. 615. Section 8.5, Page 8-Please explain what the term "HW3" means. Explanation of terms and process to assign HW branch has 9, First Paragraph, been expanded Second Line 616. Section 8.5, Page 8-Please review the suitability of using the word "range" in the context Explanation added 9, First Paragraph. of this sentence. Please also indicate whether the center and body is Last Sentence also captured. 617. Section 8.6, Page 8-The workshop summary (near the bottom of Page G-17) suggests More exhaustive documentation and evaluation of directivity 9, First Paragraph. that directivity has a significant effect on hazard. opposite to what is models is added in Chapter 6 First sentence stated in this sentence. Furthermore. there is insufficient technical material in the workshop summary to allow for a review by the PPRP. Instead of citing the workshop summary. please provide a complete documentation of the hazard sensitivity analysis that supports the conclusion given in this sentence. or provide a reference to the section of the report that does so 618. Section 8.6, Page 8-Please explain how directivity effects were taken into account or Clarification added 9, 1st Paragraph of provide a specific (chapter, subsection) reference for that Section, Last explanation. Sentence 619. Section 8.7, Page 8-There is insufficient technical material in the workshop summary to More hazard sensitivities were not run for paucity of time, 10. First Paragraph, allow for a review by the PPRP. Please provide a complete but we expect the effect not to be significant given the low Last Sentence documentation of the hazard sensitivity analysis that supports the probability of occurrence. conclusion given in this sentence or provide a reference to the section of the report that does so. 620. Section 8.8, page 8-Please see previous comments regarding the list of references for Done 10 other chapters and appendices for guidance on revising the list of references in this chapter. 621. Table 8.4-1, page 8-Please indicate in the caption what is meant by the term SOF." Done 11 622. Figure 8.2-2, Page 8-Please indicate in the caption the meaning of the various branches Done 13, caption (e.g., what is meant by the terms "SIM", "NGAW2DC-MED" etc.). 623. Figure 8.4.1, Page 8-Please define the units for the color bar and explain the "In" in the Consistent labels and units are provided for plots in 14 and Figure 8.4.2, axis labels. Also please explain why these two plots label the axes Chapters 6, 8 and 9. Page 15 "In units" whereas what seem to be corresponding plots in Chapter 9 (Figures 9.1-2a,b and 9.1-3a,b) have their axes labeled "C1" and "C2". If there is no reason for a distinction. please make changes so lh"'f lhPV " 624. Figure 8.4-3, page 8-Please indicate in the caption andlor legend the number of standard Done 16 deviations that have been used to represent the uncertainties 625. Figures 8 4-5. 8.4-6, In the captions of these figures, "cumulative density function" is Done page 8-18; and & 8.4-incorrect terminology. Please replace by "cumulative distribution 11, page 8-23 function." 626. Figure 8.4-7, page 8-Please explain the meaning of the term "total weights in the figure Done 19 caption of this and other similar figure captions. 627. Figure 8.4-12, 8.4-13, Please make the titles on the figure subplots legible. Done page 8-24; and 8.4-14. page 8-25 CHAPTER 9 Median GMC Models: PVNGS Sources 628. Sections 9.1 Through These sections are very similar to those discussing the DCPP Done 9.1.3 median GMC models. Please review those Chapter 8 comments and apply the relevant ones to the PVGNS discussion in these sections. Nole that some, but not all, of these comments are repeated below. 629. Section 9 .1 , page 9-1 , Please consider writing a more precise statement of the procedure. Done numbered item 4 For example, would it be better described as sampling from the multivariate normal distribution defined by the coefficient covariance matrix? 630. Section 9 .1 , page 9-1 , This statement is impossible to parse. Please consider rewriting to Done item 5 improve its clarity. One option to consider is breaking it into 3 items, the first stating the formation of high-dimensional vectors, each representing the ground motion predictions of a given model for a representative range of predictor variables. the second stating that a metric is defined on that high-dimensional space based on the difference in hazard level between model pairs, and the third stating that the vectors are represented in two dimensions via a (nearly) metric-oreservino maooina orocedure. 631. Section 9.1, page 9-1, Please specify that it is the two-dimensional space (i.e., after the Done item6 Sammon's mapping procedure is applied) that is discretized. 632. Section 9.1.1, page 9-To avoid confusion, having introduced the convention about red and Now there is more than one figure with the color code 2, last paragraph of green weights in connection with Figure 9.1-1, please consider red/green. section noting that Figure 9.1-1 itself does not actually show any statistical-sampling (green) weights. Also, since only one additional figure in the chapter, Figure 9.2-1, actually uses the red/green convention, it would be clearer to simply name that figure. rather than saying In Figure 9.1-1 and subsequent" 633. Section 9.1.2, Page Please describe and show the misfits to the predictions from the The misfits have nothing to do with the weights. It does not 9-2. First Paragraph, original GMPEs by the RRuP*based and RJa-based common forms. matter because they give almost same hazard results Line 8 Please discuss whether the weights (0.7, 0.3) assigned to the RRuP-based and RJa-based branches, respectively, are consistent with the misfits. 634. Section 9.1.3.1, Page Please review whether using a term like "distribution" or "center. Clarification added 9-2. First Paragraph, body. and range" would be more appropriate here than using just the Line 1 tem "range. There are other instances throughout Chapter 9 where the term "range" is used. Please also review those instances and revise where appropriate. 635. Section 9.1.3.2, Page Please explain why the Tl Team limits the dataset to events with at The justifications are given in Chapter 5 9-5. 2"0 paragraph of least 3 recordings per earthquake and whether such a limit is also section (1 used in the DCPP evaluation. Paragraph on page), 1" line on page 636. Section 9.1 32. Page In Figure 9.1-7, the M 6.6 event appears to have just one recording. The plot has been removed, instead we point at the plots in 9-5. 2"0 paragraph of Please check whether this is an error and revise if needed. Chapter 5 section (1 paragraph on page), 1 sentence on page 637. Section 9.1 32. Page In the preliminary draft of Chapter 5 (noting that we have not yet Same as above 9-5. 2"0 paragraph of seen Rev.O for that chapter), in Figure 5.1.3-2, there are a large section (1 paragraph number of recordings that appear to come from a single M 6 9 on page), t" sentence normal-faulting event. These data are not included in Figure 9.1-7. on page Please explain why they are not included in Figure 9.1-7 and are not used for PVNGS. 638. Section 9.1.3.2, Page Please verify that the 2009 M 6.3 L'Aquila earthquake is included in Clarification added. We used the datasets are provided and 9-5, 2"0 paragraph of the EURPV-Meo data set. If not. please explain why not. Also. please did not evaluate if the same events were included in the section (1"' paragraph discuss whether all European events in the PEER NGA-West2 altemative datasets on page), last database satisfying the minimum of 3 recordings-per-event sentence requirement are captured in EURPv*MED* If not, please explain (preferable in Chapter 5) why they were excluded. Conversely, please discuss if all EURPv-Meo events are included in PEER's NGA-West2 database. If not, please explain whey they were excluded. 639. Section 9.1 32. page Since weighting is used in several different senses in the chapter, Clarification added 9-5, 4th paragraph of please consider adding a phrase to clarify that there is no section (3'0 on page), reweighting of different style-of-faulting cases in the calculation of the last line mean-residual and likelihood. if that is the meaning that is intended here. 640. Section 9.1 32. Page Please explain what "differences in mean residuals" mean. The Clarification added 9-5, 5tto Paragraph of definition given in Section 6.4.5 does not mention the word section (4'h on page). "difference". Line 3 641. Section 9.1 3 2. Page Please clarify whether the phrase "range of underlying GMPEs" Clarification added 9-5, s*h paragraph of means the range of predictions of the median amplitude by the section (4'h on page). underlying GMPEs. Also, please clarify whether the epistemic-Last Sentence uncertainty versions are also used in the evaluation of mixing weights. 642. Section 9.1.3.2, Page Please discuss the Tl Team's assessment of the quality of the No further evaluations provided 9-6, 7'h paragraph of EURPv-Meo dataset, such as issues related to record screening (for section (1"' Paragraph example, removal of low signal-to-noise ratio records and non-free on page), Line 4 field records), record processing. and accuracy of magnitude estimates. Also please clarify whether both data quality and data coverage in the key magnitude range are considered in the Tl Team's assessment of relative weights. If the answer is yes, please document Tl Team's evaluations and conclusions. If the answer is no, please provide further justification of the ratio of 3: 1, accounting for these two additional considerations. 643. Section 9.1.3.3, page Please correct this term to the correct term "cumulative distribution Done 9-6, 1" paragraph of function. section, line 2 644. Section 9.1.3.3, page For the NGA dataset. the residual approach (blue curve) seems to Clarification added 9-6, 1" paragraph of give a narrower distribution than does the likelihood (orange curve). section, 2°d to last If this is true, it contrasts with the categorical statement to the sentence contrary in the text, which is confusing (even though it doesn't vitiate your main point about the advantages of the weighted model). Please clarify. 645. Section 9.1.3.3, page As in Chapter 8. please correct the phrase "distance scaling and Sen1ence corrected 9-7, ih paragraph of distance scaling". section (4111 on page). line 2 646. Section 9.1 3 3. page 9-8, g*h paragraph of section (2°d on page). Please substitute "and" for the slash between California and Mexico Done throughout the report line4 647. Section 9.1.3.3, Page Please explain why the uncertainty in hazard shown in Figure 9.1-Done 9-8, gth paragraph of 19a (for Model A) is much larger than the hazard uncertainty shown section (2"" on page). in Figure 9.1-19b (for Model B). _ Lines 5 to 7 648. Section 9.1.3.3, Page Please clarify whether the mean hazard is weighted by the branch That's the definition of the mean hazard, which has the 9-8, 1 O'" paragraph of section (3'" Paragraph weights. branch weights in it. No change in text. on page), Line 1 649. Section 9.1.3.3, Page Please include in Figures 9.1-19 and 9.1-20 a curve representing the See answer to 649 9-8, 1 O'" paragraph of average hazard from the original GMPEs. section (3'0 Paragraph on oaae}. Line 2 650. Section 9.1.3.3. Page Please explain why the epistemic versions of the original GMPEs We added a new figure with the mean hazard from the 9-8, Last Paragraph of are not included in Figures 9.1-19 and 9.1-20 to help judge the candidate GMPEs, and from the candidate GMPEs with section appropriateness of the selected common-form models in capturing additional epistemic uncertainty, in the same way we did in the CBR of the median motion. Chapter 8 651. Section 9.1.4, page 9-Please express quantitatively what is meant by "nearby" (where Done 8, 1 *1 paragraph of there are no known faults), and give the justification for neglecting section, line 1 directivity effects for identified faults outside that region (or specific reference to a report section that provides the justification). 652. Section 9.14, Page Please further clarify the statement 'The GMPEs capture this Clarification added 9-8, Line 6 random case" and how it supports the Tl Team's decision to give zero weight to the directivity adjustment branch. 653. Section 9.1.5, Page Please indicate that the tectonic regime of the Wells earthquake is Done 9-9, 1st Paragraph, the same as for the PVNGS site region. but that the tectonic regime 2nd Sentence for the Japan earthquake is not. 654. Section 9.15 1. Page Without plotting residuals against the directivity parameter, it is Discussion on directivity has been removed 9-9, 2"" Paragraph, difficult to form a definite conclusion regarding the existence or the Second Sentence level of the directivity effect. Please either add a plot to support the conclusion or revise the sentence to be less definite. 655. Section 9 .1 5 1. page 9-9, 2"d paragraph, Please replace "with respect the" with "with respect to." Done line 5 656. Section 9 .1 5 1. page PGV residuals are not shown in Figures 1-15 and 1-16. According to The text "In contrast, the PGV data are much lower than 9-9, paragraph 2, line Appendix I (Section 1.3.2, Second Paragraph). residuals in Figure I-GMPEs with an average residual of -0.74 natural log units." 5 15 are with respect to CY14 only, not to the four NGA-West2 has been removed GMPEs. Also. residuals shown in Figure 1-16 are averages over six candidate GMPEs. Please revise this paragraph to be consistent with Appendix I. 657. Section 9.151. Page Because the Wells earthquake occurred in the same tectonic regime Residuals wrt Bi14 and ASB14 were evaluated in Figure 1-9-9, 2nd Paragraph of as the PVNGS site, its ground motion is very relevant to 17. Residuals for various periods were evaluated with Section, Last understanding the ground motions that might occur at PVNGS from respect of CY14 in Figure 1-16. Evaluation of the data is Sentence normal-faulting events. Please state what conclusions were drawn included in Chapter 9 from the observations regarding the validity of the NGA-West2 GMPEs to estimate normal-faulting ground motions at the site. Please also indicate why neither the Bindi et al. (2014) GMPE nor response-spectral values in addition to PGA and PGV were evaluated. 658. Section 9.1.5.2. Page Please clarify whether the definition of a complex rupture adopted by Clarification provided 9-9, First Paragraph, the Tl Team is applicable to the case of disjoint ruptures as seen in Line 1 the Fukushima-Hamadori earthquake. 659. Section 9.1.5.2, Page Please justify that the SSRS method is the preferred method for Discussion added 9-9, First Paragraph, computing ground motion from the Fukushima-Hamadori Line 5 earthquake, given that the evaluation of alternative methods for complex ruptures (Section 6.7 and Sections J.2.2 and J.3.2) does not include disjoint rupture scenarios as seen in the Fukushima-Hamadori earthquake. 660. Section 9.1 52. Page Please explain why the Bindi et al. (2014) GMPE was not evaluated, Yes, the Japanese factors were used for the GMPEs that 9-9, First Paragraph, given that it was one of the candidate GMPEs. Please also indicate if include those. Bindi et al. (2014) and Akkar et al. (2014) do 4'" sentence the Japan regional factors in the NGA-West2 GMPES were used to not have Japan-specific terms and were not evaluated evaluate the Fukushima-Hamadori, Japan earthquake. 661. Section 9.1 5 2. Page Please provide a figure similar to Figure 9.1-21 for the Wells Not done at this time 9-9, 1st Paragraph of earthquake. Section, 7th Line 662. Section 9.1.5.2, page Please consider whether an accessible document can be cited Tl T earn evaluation is now provided 9-9, 3r0 paragraph of instead of personal communication, and if not, consider whether the section, line 2 observation cited is of real significance to the assessment. 663. Section 9.1.5.2, page The personal communication cited here entails a claim of local See answer to 662 9-10, 3r<1 paragraph of stress heterogeneities. without reference to a data source. and a section ( 1 *1 on page), "suggestion" about rupture behavior that is difficult to distinguish from lines 9-14 simply an offhand speculation. Please consider first whether this passage is essential to the Tl Team's assessment. If so, please consider whether there is a documentary source for the observation of stress heterogeneity. Also consider whether stating a Tl Team judgment (based on review of the available evidence) that the event cannot be discounted (as an Arizona proxy) might be as authoritative, and more direct, than citing Dr. Stein's undocumented suggestion. 664. Section 9.1.5.2, page Please reference where in the report and/or appendices the Comment inserted into Chapter 9 9-10, 4"' paragraph of additional variability gleaned from the evaluation of the Wells and section (2"" on page), Fukushima-Hamadori earthquakes is taken into account. 665. Section 9.2, Page 9-Please explain why the Sammon's mapping approach was not used A new plot is now available, showing PSA scaling versus 10, General to develop the set of models used to estimate ground motions from distance, for the NGA-W2 models corrected for the median the distant California and Mexico sources in Regions 1, 2, and 3. path terms and their uncertainty (15 curves) -separate plots Please also include figures to demonstrate the distribution of ground are provided for each region (Region 1 and combined motion values that are implied by the logic-tree model that Regions 2&3) represents these sources. 666. Section 9.2.1, page 9-The phrases "California/Mexico" and "California -Mexico" should Done 10. paragraph 1 read "California and Mexico." 667. Section 9.24, Page Please specify the applicable distance range of Al-Atik and Youngs Clarification added 9-11, First Paragraph. (2014) and comment on its applicability to the distant California and Line 4: Mexico sources. 668. Section 9.24 1. Page First Paragraph of Section 9.2.4 indicates that this section is about Clarifications added 9-11, 1 "' Paragraph of epistemic uncertainty in median prediction by the NGA-West2 section, Line 4 GMPEs, whereas this sentence and the remainder of this subsection indicate ifs about uncertainty in the path effect. This is very confusing. Please clarify or reorganize as needed. 669. Section 9.2.4.1, page Please cite the relevant appendix section(s) and figure(s) where the Done 9-11, 1"' paragraph of details are given. section, lines 6-9 670. Section 9.2.4.1, page Please provide a reference and clear explanation for the equation. Done 9-12, Eqn 9.2-1 671. Section 9.2.5, Page A description of the standard deviation used by the Tl T earn to Reference to Appendix P added 9-12, Second compute the 5'" and 95'" values is missing. Please provide such a Paragraph, Line 1 description along with Tl Team's justification for the value used. That description should also clarify why the weights stated at the end of Section 9.2.4.2 and elsewhere in the report differ (slightly) from the 0.185, 0 63 and 0.185 weights used by Al Atik and Youngs (2014) and recommended by Keefer and Bodily. 672. Section 9.2.6, Page Please provide a reference for 1he sta1ement that "The distant Clarification added 9-12, 1st Paragraph of California strike slip sources are located at distances well beyond Section, 1st Line where directivity effects are observed in the empirical data. 673. Section 9.3, page 9-Please see previous comments regarding the list of references for Common issues fixed (e.g., citation volume/issue/pages, 13, General comment other chapters and appendices for guidance on revising the list of 2014a vs. 2014, etc.) references in this chapter. 674. Figure 9.1-1, page 9-The caption should include the information on the meaning of the Done 15 red and green weights (as discussed in the text), while noting that 1here are no statistical (green) weights presen1 in this case. 675. Figure 9. 1-2a, Page Please indicate the type of residuals (i.e., between-event, within-Done 9-16, 5th Line of event, total) here and elsewhere throughout the chapter when the Caption term "residuals" is used. 676. Figure 9. 1-2 & 3, Please provide a label giving the color bar units, or provide that Done pages 9-16 to 9-19 information in the caption 677. Figure 9. 1-5, page 9-Please rewrite the caption to correct typographical errors and make Done 21 it more informative. 678. Figures 9.1-8, page 9-The caption in each of these figures should be corrected to read Captions corrected 24: and 9.1-9, page 9-"cumulative distribution function." Please also improve the readability 25 and resolu1ion of 1hese figures and several subsequent ones-they are fuzzy and the numbering is nearly illegible. 679. Figure 9.1-14a-e. All of the influence plots are fuzzy and need improved resolution. Captions improved pages 9-30 through 9-Plus, the lettering is too small and illegible. The captions could be 34 improved with better explanations of the plots. CHAPTER 14 Hazard Sensitivity 680. General comment Subjective sta1ements such as "main contributing, controlling, Done to the best of ability significant, small, little impact", etc. are used throughout the chapter to describe results. Please provide a quantitative description of such statements in order to avoid ambiguity. 681. Section 14.1, Page Please provide specific references (i.e., documents or presentations) A new table has been inserted 14-1, 1st Paragraph, to the hazard sensitivity studies that were provided throughout the 1st Sentence project. 682. Section 14.1, page The sensitivity estimates have been invoked at many points in the Goal is to capture the type of sources that are contributing, 14-1, 1"' paragraph report as a rationale for various model simplifications. Therefore, so that's ok for us please consider adding a short discussion to further justify the validity of using the earlier SSC models for DCPP and PVNGS as the base case for this purpose (and emphasizing that the older models are used only for that purpose). 683. Section 14.1, page Has the acronym "NPP" been defined. or even used at all elsewhere Done 14-1, 2°d paragraph of in the report? Please consider whether it is worth introducing this section, line 3 acronym and defining it here, in lieu of just writing out what it means. 684. Section 14.1, page If the term tornado plot" has not been defined earlier in the report, Description provided 14-1, paragraph 3 of please provide a brief description of its form and construction. If section, 3*c sentence there was an earlier definition given, please provide a specific section reference. Please also clarify that the y-axis value alluded to at the end of the sentence is that of the hazard curve, not that of the tornado plot itself. And since not all of the sensitivity studies are summarized in Tornado plots (e.g., the source contributions are shown as graphs and deaggregation histograms) please indicate that these other results are shown in other formats 685. Section 14. 1, page Please clarify the meaning of "weighted mean" in this context (e.g., Done 14-1, 3rd paragraph of how are the individual ratio values weighted?). section, line 6 686. Section 14.1, Page This statement implies that the results could be different enough to Our sensitivity analysis is not representative of final hazard 14-2, last paragraph be of concern. In this case, please justify why it is sufficient to use level, but is representative of the contribution from the of section (1st on the older SSC models for the hazard sensitivity studies. Please also different branches. A clarification has been provided page), Last Sentence consider moving this caveat and its discussion and justification to Section 14.1 at the beginning of the chapter as recommended in an earlier comment. 687. Section 14.2, page Here. and elsewhere in the report (e.g .. Section 14.2, Page 14-4). Done 14-2, paragraph 1. please add "fault" after Shoreline. Los Osos, San Luis Bay. etc. lines 2 & 6 These are formal names and should be spelled out in full. 688. Section 14.2, Page Please indicate how the fractional contribution of the different Clarification provided 14-2, 1st Paragraph of seismic sources to the total mean hazard was determined. If ii was Section, 2nd done using deaggregation, please indicate that this is the case and Sentence define what deaggregation is and how it is done prior to discussing the results. 689. Section 14.2, Page Please indicate that the deaggregation is done on the mean hazard Clarification provided. That's the only way it is done. 14-4, 1st Paragraph here and elsewhere thought the chapter and appendices. on page, 1st Line 690. Section 14.2, Page Please also show the 10*0 hazard deaggregation histograms for Done 14-4, 1st Paragraph completeness. on page, 1st Line 691. Section 14.2, Page Please explain how the deaggregation histograms show that the Clarification added 14-4, 1st Paragraph hazard at DCPP is controlled by the four local faults when no on page, Last sources are identified in these plots. Sentence 692. Figures 14.2-3 and The entire report addresses hazard on a reference site condition Done 14.2-4, Pages 14-5 corresponding to Vs30 = 760 m/sec. Because of this. ii is confusing and 14-6, Figure to describe the hazard as being for "rock". Please delete the word Captions rock to avoid confusion. 693. Section 14.2.1, Page Please change 14.3-6b to t4 2-6b Done 14-6, First Paragraph, Last Line 694. Section 14.2, Page Please consider revising the x-axis title in this figure and other Additional explanation of the tornado plots addresses this 14-8, Figure 14.2-Sa similar figures in Chapter 14 to reflect the no1111alization of ground-question See comment 684 motion ratio discussed in Paragraph 3, Page 14-1. 695. Section 14.2.2, page This sentence would benefit from minor rewording to avoid Done 14-11, paragraph 2, ambiguity. Please consider whether its meaning could be correctly last line on page rendered by ..... with the weighted average of the phi ** models, including only the central aleatory-variability branch on phi." 696. Section 14.2.2, page Please refer to specific figures when referring to "the fifth line ... ". Done 14-12. 4th paragraph This needs to be done throughout this section (next several of section (3'd on paragraphs) and the remainder oflhe chapter, as the absence of page). line 3 and specific references leaves some ambiguity as to which tornado plot elsewhere is being cited. 697. Section 14.2.2, Page The sensitivity oflhe mixture high model appears to be as great as Done 14-12. 7'" paragraph many of the other parameters. Please consider revising this of section (6th on statement to better reflect the results shown in the tornado plots. page) 7th Sentence 698. Section 14.3, page Please check lo ensure that all of the names and abbreviations that CP and CP-F corrected. The nomenclature is consistent 14-21, abbreviation are listed here are used consistently throughout the report. For with the LCI 2013 PVNGS SSHAC level 2 SSC zonation. lists instance, is Gulf of California referred to as GZ consistently (and not Note that the PVNGS L2 report mixes between GF and GC) and why is the -F added to CP for Colorado Plateau? This is GULF. We have chosen GULF now to be consistent with potentially confusing, because CP is listed here for the Cerro Prieto most of the figures and their Level 2 HID fault (and ii would seem more logical to have the F identifying a fault). Please also reference this list back to a figure. 699. Section 14.3, page Please revise this statement to make it clear whether the 99% Done 14-2 t. 1 ** sentence contribution to the total hazard is from the background (area?) after bullet 11 sources, the fault sources, or the combination of both. 700. Section 14.3, page Please specify which faults are the distant fault sources. Done 14-22, 1"' paragraph after bullet 26, 1" line 701. Section 14.3, page Please clarify which modeling choices were made by LCI (2013) and Clarification added 14-22. 1st paragraph which ones were made by the Tl Team. Regarding those made by after bullet 26, and the Tl Team, please justify the choices made with respect to their 3'd sentences implications in identifying hazard-sensitive models and parameters. 702. Section 14.3, page Please be specific and precise about the meaning oflhe phrase " ... a Done 14-22. 1** paragraph pure characteristic earthquake magnitude distribution ... " as used in after bullet 26, line 7 this context 703. Section 14.3, page 14-22. 2"" paragraph Please explain how the source contributions were calculated. Done of page after bulleted items, t sentence 704. Section 14.3, page Please justify the use of the specific sigma value of 0. 65. The correct sigma value is the one from BSSA14. 14-22. 2"" paragraph Clarification added of page after bulleted items, 4'" line 705. Section 14.3, page Please add the missing word "greater before "than in the phrase Done 14-22. 211* paragraph "For ground motion values than 0.1 g. of page after bulleted items, line 7 706. Section 14.3, page If this paragraph is intended to be a summary of the results in The corresponding hazard level is provided to clarify the 14-24, 1" paragraph Figures 14.3-1 and 14.3-2, please explain how one reconciles the statement. on page categorical statements in this paragraph with the period-dependent results in the figures. For example, Figure 14.3-2 appears to indicate that SBR sources dominate 0.5 Hz hazard at levels exceeding about 0.15 g, which appears to contradict the categorical statement that "distant fault sources are the dominant contributor to hazard at lower spectral frequencies." Shouldn't the statements in this paragraph be conditional on something (e.g., the probability of exceedance range of interest)? Please also indicate whether this apparent contradiction is related to the observation made later in Section 14.3, Page 14-25, top 2 lines on page. 707. Section 14.3, page Please quantify what is meant by "local small" and "distant large" in Clarification added 14-24, 2"' paragraph this context. on page, 2"d and 3r<1 sentence 708. Section 14.3, Page Please also show the 10-0 mean annual hazard deaggregation Done 14-24, 2nd Paragraph histograms for completeness. on page, 4th Sentence 709. Section 14.3, page This observation may be related to the above comment made about Addressed in response to 706 14-25. top 2 lines on Section 14.3, Page 14-24, t" paragraph on page. page 710. Section 14.3.1, page The phrase "there are not known active faults" is at best an awkward Done 14-27. 2"" paragraph construction, and potentially ambiguous. Please reword for clarity. of section ( 1 *1 on page). line 1 at top of page. 711. Section 14.3.1, page Please provide reference to the report section where the neglect of Done 14-27, 2"' paragraph directivity effects was justified. of section (1"' on page), top 2 lines on page 712. Section 14.3.1, page Please indicate what the statement "little impact" is compared to. Done 14-27. 3rd paragraph of section (2"" on page). 713. Section 14.3.1, page Please refer to specific figures that are related to this discussion. Done 14-27. 4"' paragraph of section (3'd on page) 714. Section 14.3.1, page The explanation of the greater range at lower hazard level in terms Further explanations provided 14-27. 4*h paragraph of depth scaling requires some amplification. Please provide some of section (3'd on further explanatory remarks. page). lines 9 and 10 715. Section 14.3.1, page Please add the missing word "for in the phrase " ... lo the hazard and Done 14-27, 4*h paragraph produce a noor the hazard estimate ... " of section (3rd on page), line 15 716. Section 14.3.1, page Please revise this statement to clarify its meaning (i.e., are the Yes they are fractional contributions. We think the 14-27. 41h paragraph values shown really fractional" contributions?) sentences are clear of section (3'd on page). last sentence 717. Section 14.3.1, page Please refer to specific figures that are related to this discussion. Done 14-27. S"' paragraph of section (411' on page), general comment 718. Section 14.3.1, page Please consider rewording this sentence so as not to categorize the Done 14-27. 5"' paragraph GMPE prior estimate as a "dataset." The subject here is really of section (41"' on sensitivity to elements of the weighting scheme for the median base page), 1" sentence models (Figure 9.1-5), only some of which are datasets. 719. Section 14.3.2, page Please provide a reference to the report section where the neglect of Done 14-31. 1 *1 paragraph directivity effects was justified. of section. 2*** sentence 720. Section 14.3.2, page Please refer to specific figures that are related to this discussion Done 14-32, first 3 paragraphs on page 72t. Section 14.3.2, page Please clarify where in the report the additional epistemic cross reference provided in page 14-33 14-32, 4*h paragraph uncertainty in the magnitude scaling is discussed and which node in of section (3rd on Figure 9.2-1 models this uncertainty. oaoel, line 1 722. Section 14.3.2, page It should be clear at this point that the different model sensitivities We do have a changing base but normalized to be 1. 14-32, 4'" paragraph are with respect to a common base case (ie .. the denominator) and; Clarification added of section (3"' on therefore, all represent changes in the numerator. Please remove page). line 3 this reference to the numerator in order to avoid confusion that these results are somehow different than the previous ones. 723. Section 14.3.2, page This sentence is poorly written (including seemingly redundant Sentence rewritten 14-32, 4*h paragraph constructions such as "approach application and "in with"). Please of section (3rd on rewrite this sentence for clarity and precision. Also, please check page). lines 7 & 8 whether the "i.e." in the parenthetical note correctly conveys the intended meaning (i.e .. the i.e" implies some sort of equivalence between the preceding clause and the parenthetical observation, which mav not be intendedl. 724. Section 14.3.3, Page Please do not use a slash (e.g., in the term the Phiss/PhisP*R) unless Done throughout the report 14-36, 1st Paragraph, it is intended to represent a ratio here and throughout the chapter. 2nd Line 725. Section 14.3.3, Page Please explain why the BSSA 14 GMPE was used for the sigma Explanation added 14-36. 1st Paragraph, sensitivity studies and the CB14 GMPE was used for the median 6th Line sensitivity studies. 726. Section 14.3.3, Page Please provide, in the text, the spectral frequencies that are Done 14-36. 2nd associated with Figures 14.3-9 and 14.3-10. Paragraph, 1st Line 727. Section 14.3.3, Page This is the first time that the values of ratios are given. Please be The ratios values are removed 14-36, 2nd consistent in either providing such ratios or not providing them Paragraph, 41h Line 1hroughout the chapter. If the ratios are not provided, the subjective statements describing these ratios should be quantified (see General Comment on this chapter). 728. Section 14.3.4 page 14-41. 3*d paragraph Please reference specific figures related lo this discussion. Done of section ( 1 *1 on oaael 729. Section 14.3.5, page Please check whether "0.5 Hz should be "5.0 Hz." Checked 14-46. 3rd paragraph of section ( 1 "' on page). line 1 730. Section 14.3.5, page Please describe the three models that are shown for the "with path Done 14-46, 4'h paragraph and 'without path" rows in Figures 14.3-13a, 14.3-13b, 14.3-14a, and of section (2nd on 14.3-14b. page), 1*1 sentence 731. Section 14.3.5, page Please consider whether the intended meaning of this sentence Done 14-46, 4'h paragraph would be better conveyed by "because of' rather than "based on" of section (2"d on page). line 4 732. Section 14.3.5, page This statement does not seem to be consistent with the figures. Done 14-46. S"' paragraph Please revise this statement to better reHect the results shown in the of section (31d on tornado plots. page). 6'" sentence 733. Figure 14.3-13b, page The caption reads correctly that this plot is for 5 hz (as stated in the The correct figure is now inserted 14-48 tex1) but the header of the figure reads 0.5 Hz. Furthermore, the plot looks identical to Figure 14.3-14b. Please make sure this is the correct plot and either correct the header or replace it with the correct plot. 734. Section 14.3.7, Page Use of the term distribution is confusing. Please consider replacing Done 14-54, 1st Paragraph, "distribution" with "sensitivity". 9th Line 735. Section 14.3.7, Page The NGA-West2 models only show significant sensitivity at 0.5 Hz, Done 14-54. 1st Paragraph, so this general statement is confusing. Please consider deleting this 101" Line sentence and making statements regarding the impact of these models separately for 1he two frequencies. 736. Section 14.3.7, Page Use of the term uncertainty is confusing. Please consider replacing Done 14-55, (1st "uncertainty" with "sensitivity". Paragraph, 3rd Line 737. Section 14.4, Page Please see previous comments regarding the list of references for Common issues like volume/issue/page numbers fixed, not 14-58. General other chapters and appendices for guidance on revising the list of cited references removed references in this chapter. APPENDIX H Evaluation of Common Form Models 738. General The format of the appendix is different from that of the report and The format and content of Appendix H was not modified in other appendices. Please reformat the appendix to be consistent Rev.1 with the rest of the report. In Rev.2 instead, the introductory material of Appendix H was a summary of Attachment E (not provided anymore), and included also the explanation of the plots. All the other information on dataset and candidate GMPEs is already provided in the main report, and were removed from the Appendix H. In both versions of Appendix H in Rev1 and Rev.2, we were not in control of the formatting of the material. 739. Chapter 1, General The text is very cryptic and contains a myriad of terms and See answer to comment 738 acronyms, making it comprehensible to only those that have a good understanding of the topic. Please expand the text to be more descriptive and ensure that all of the used terms and acronyms have been clearly defined in the main report prior to referencing the appendix or. if not, that they are defined in the appendix the first time they are used. 740. Chapter 1. Tables 1 . 1 The table captions should specify units for the ground motion levels. See answer to comment 738 and 1.2, page 2 741. Chapter t. Section Please indicate what the GMPEs are used for. See also 1st Line of See answer to comment 738 1.1, Page 1, 4th 5th Paragraph. Paragraph, 1st Line 742. Chapter t. Section Please replace "(2014)" with "(2014a,b)" in the Akkar et al. (2014) See answer to comment 738 1.1, Page 1. 4th reference to indicate that both the original manuscript and the Paragraph, 2nd Bullet erratum were published in the same year and add the reference to the erratum in the list of references. See also 3rd Bullet in 5th Paragraph. 743. Chapter 1, Section Zhao and Lu (2011) do not present a GMPE, but rather an approach See answer to comment 738 1.1, Page 1, 4th to magnitude-scaling at large magnitudes. Please define a new Paragraph, 8th Bullet GMPE that incorporates the proposed magnitude-scaling in Zhao and Lu (2011) and identify it by a unique acronym. 744. Chapter t. Section Please replace "(2014)" with "(2014a,b)" in the Bindi et al. (2014) See answer to comment 738 1.1, Page 1, 5th reference to indicate that both the original manuscript and the Paragraph, 3rd Bullet erratum were published in the same year and add the reference to the erratum in the list of references. 745. Chapter 1, Section Please add the missing word "not" in the phrase "but do See answer to comment 738 1.1.1, page 3, paragraph 1 , 2"" to incorporate". last line 746. Chapter t. Section Please justify the basis for the weights assigned to the median and See answer to comment 738 1.1.1, Page 3, 2nd plus/minus uncertainty of the GMPEs. Paragraph, 7th Line 747. Chapter t. Section Please define the meaning of the term "total weights". See answer to comment 738 1.1.1, Page 3, 3rd Paragraph, 1st Line 748. Chapter t. Section Please avoid the use of slashes (e.g., in width/range) unless it is See answer to comment 738 1.1.1, Page 3, 3rd intended to represent a ratio. Paragraph, 3rd Line 749. Chapter 1, Section Please define the meaning of the term "all weights" and how it differs See answer to comment 738 1.1.1, Page 3, 7th from the term total weights". Paragraph, 2nd Line 750. Chapter 1. Section Please reference the logic tree that documents the weights that are See answer to comment 738 1.1.1, Page 3, 8th assigned to Models A and B for PVNGS. Paragraph, 2nd Line 751. Chapter 1. Section Please update the references to the various datasets to use the See answer to comment 738 1.1.1, page 3. 8"' terminology introduced in Chapter 5, and reference the appropriate paragraph, line 5 section and table from that chapter. If the term "weighted NGA dataset" is not explained in Chapter 5, please explain that term here. 752. Chapter t, Section Please clarify what those" refers to in what appears to be part of an See answer lo comment 738 1.2, Page 5, 1st incomplete phrase. Paragraph, 1st Line 753. Chapter 1, Section Please provide references to the simulation methods of EXSIM, See answer lo comment 738 1.2, Page 5, 1st Graves and Pitarka (i.e., G&P), and SDSU. Paragraph, 3rd Line 754. Chapter 1, Section Please clarify what "models" are being referred to. See answer to comment 738 1.2, Page 5, 1st Paragraph, 5th Sentence 755. Chapter 1. Page 7. Please ensure that all of the references are cited in the text and are See answer to comment 738 Bibliography complete, and add missing references identified in the text. 756. Chapter 2. General Please provide a short introduction to the figures that are presented See answer to comment 738 in the report. 757. Chapter 2, Section Please provide units for the legend bars in the figures showing the See answer lo comment 738 2.1.2 Sammon's maps. 758. Chapter 2. Section Please explain why the distribution of hazard curves for the selected For discussion on the main chapters. not in the appendix 2.1.4 models covers a smaller range of hazard than that for the 2000 curves and what impact that has on the final results 759. Section 2.1.4, Page To help visually compare the hazard distribution from the selected For discussion on the main chapters. not in the appendix 53, Figure 2.69 model to the distribution from all 2000 sampled models, please add the 5%, 50%, and 95% curves of the latter distribution to bo1h plots. Also please increase the size of each plo1 for ease of viewing. 760. Chapter 2. Section Please define the acronyms in the legend that are used to describe Done 2.1.5 the GDF curves in the figures. Also please change "cumulative density function" to "cumula1ive distribution function" in all captions, here and throughout the report. 761. Section 2.1 6, Page Please explain what causes the ramp-up of the lower black curve on For discussion on the main chapters. not in the appendix 106, Figure 2.202 this figure and other figures. 762. Section 2.1 . 7, Page Please explain what causes the ramp-up of the lower red curve on For discussion on the main chapters. not in the appendix 107, Figure 2.208 this and other figures. 763. Section 2.1.81.4.7, Please explain why, at Rx= -1, the GMPE distribu1ion is much more For discussion on the main chapters, not in the appendix Pages 137 and 140, sensitive to the value of F (style-of-faulting flag) than the Model A Figure 2.272 vs. distribution is. Figure 2.281 764. Chapter 3. General Please see comments for Chapter 2. Ok 765. Chapter 4, General Please see comments for Chapter 2. Ok 766. Chapter 5. General Please see comments for Chapter 2. Ok APPENDIX I Wells (NV) Earthquake 767. Section 1.1, Page 1-1. Please provide a reference for the statement that "The tectonic Added reference to Chapter 4 where the the topic is 2nd Paragraph, 1st setting, magnitude, and focal mechanism of this earthquake are all discussed Sentence consistent with the seismic sources in the Southern Basin and Range that contribute significantly to the hazard at high frequencies at the Palo Verde Nuclear Generating Station (PVNGS)". 768. Section 1.1, page 1-1, The acronym" NGA-W2" was given as "NGA-West2" elsewhere in Done throughout the Appendix 2"' paragraph, line 5 the report. Please standardize the terminology and acronyms throughout the report. 769. Section 1.2.1, Page 1-Please provide a summary of instrument response, sampling time Information such as 40 samples per second, broadband 1, 1 *1 Paragraph of interval, and possible limitations of the USTA recordings for use in seismometer, flat response in the 0.01 -16 Hz frequency section, Line 7 the comparison with GMPEs described in Section 1.3. range, etc were added to the text Limitation is that PSAs below 0.075 sec are not reliable due to sensor response. Specs and limitations described in the text 770. Section 1.2.1, page 1-US Transportable Array is abbreviated "USTA" here, while TA used everywhere in the Appendix 1, 1 *1 paragraph. line 7 elsewhere it is referred to as "Transportable Array" and abbreviated as "TA". Please standardize the terminology and acronyms throughout the report. 771. Section 1.2.1, page 1-Please clarify the meaning of the term "temporary stations. If these We clarified that those are TA temporary stations. 1, 1"' paragraph, line 8 temporary stations are the USTA stations, please indicate such in the text. 772. Section 1.2.1, page 1-1, 1 *1 paragraph. last 2 Please add either a period or semicolon following "100km". Period added lines 773. Section 1.2.2, Page 1-Please clarify that the Wills and Clahan (2006) relationships A discussion on the regional dependence of VS30/geology 2, 2nd Paragraph, 1st between geologic units and Vs30 are based on California data and proxy has been added. The estimated impact of a Vs30 Line geology and might not be appropriate for Nevada. Please also uncertainty of about +-0.15 (LN units) on the total residual discuss the potential significance of this assumption on the results. has also been addressed. 774. Section 1.2.2, Page 1-Please provide units for the Vs30 values of 600 and 750 mis. Done 2, 2nd Paragraph, tst Sentence 775. Section 1.2.2, Page 1-Please explain why there is no proxy Vs30 value for Station M12A Done 2, 2nd Paragraph, 2nd shown in Figure 1-2. Later in the text it is noted that this station Sentence clipped and was not used. but that information is not available at the point in the appendix where this figure is referenced. 776. Section 1.2.3, page 1-The record for station N12A also looks clipped in Figure 1-3. Please Record for station N12A is not clipped. No change in the text 2, 1"' paragraph of consider whether that is the case, and if so, whether ii is appropriate section, line 7 to comment on that record as well, in order to be consistent. 777. Section 1.2.3, Page 1-Please explain why a focal mechanism from UCB was used rather The focal mechanism is provided as reference, but the finite-2, 1st Paragraph of than one from a more local source (e.g., the UNR Seismological fault inversion from Dreger et al (2011) was indeed used for Section, Last Laboratory). or from the study of Dreger et al (2011) or the USGS computing the finite-fault distances in a compatible manner. Sentence NEIC. Clarifying text provided. 778. Section 1.3.2, Page 1-Please add the references for Abrahamson et al. (2014), Boore et al. References added 3, 1st Paragraph of (2014), Campbell and Bozorgnia (2014), Chiou and Youngs (2014). Section, 2nd and Idriss (2014) to the list of references Sentence 779. Section 1.3.2, Page I-Please replace "2013 (ASB 13 )" with "2014a ,b (ASB 14 )" and add the References enhanced as suggested 3, 1st Paragraph of Akkar et al. (2014a.b) original manuscript and erratum to the list of Section, 2nd references. Sentence 780. Section 1.3.2, Page I-Please replace "2013 (BIN13)" with "2014a,b (Bi14)" and add the References enhanced as suggested 3, 1st Paragraph of Bindi et al (2014a,b) original manuscript and erratum to the list of Section, 2nd references. Sentence 781. Section 1.3.2, Page I-The statement that the NGA models are a better short-period fit than More precise evaluation is provided. 3, 3'0 paragraph, last the Euro models does not seem correct without a more specific line statement of the period range (e.g., it appears that the absolute value of the average residual is similar between NGA and European datasets up to a period of -0.05 seconds). Please fonmulate the conclusion more precisely. 782. Section 1.3.2, Page 1-This paragraph summarizes the observations of the analysis given in The evaluations are given in Chapter 9, not in this Appendix. 3, 4th Paragraph of Appendix I, but does not provide conclusions whether the Wells No change in the text. Section earthquake data indicate that there is a potential issue with the applicability of the NGA-West2 or European GMPES to the greater Arizona region. Please provide conclusions based on the observed comparison shown in this appendix and demonstrate, perhaps statistically, whether the Wells ground-motion data is consistent with the empirical GMPEs over the period range of interest. 783. Section 1.4, Page 1-3 Please revise the list of references to include missing references Done and to update those references that have incomplete information. 784. Figures I. 1 to I. 14 Please provide missing or more meaningful figure captions. Done for figures 1-1 to 1-14 785. Figure 1.15, Page I-Please indicate that these residuals were calculated with respect to The residuals are now shown for all the candidate GMPEs 19, Caption the CY14 GMPE. 786. Figures 1.16, Page I-Please indicate that the mean residuals are calculated with respect Accurate caption provided 20, Caption to all 7 sites in the upper plot and provide a description of what is shown in the lower plot. APPENDIX J Forward Finite Fault Simulations for SWUS 787. General There are a lot of analyses being described in this appendix. some Issue resolved in Rev.2 of which are attributed to unspecified authors or by the pronouns "I". "we", "our", etc. Please indicate who performed the analyses (e.g., the Tl Team or some other Resource or Proponent Expert) and avoid the use of pronouns, which refer to unspecified authors of the appendix. 788. General comment This appendix deviates stylistically from others, in that some Issue resolved in Rev.2 subsections are given headers but left unnumbered. For example, within Section J.2.2, on Page J-10 there is a heading "Scenario 1: Hosgri that is unnumbered, whereas following convention established in other chapters this should have become Section J.2.2.1. Please edit the chapter for uniformity of style with the rest of the report. 789. Section J.1, page J-1. Please include a reference describing the SCEC Broadband Done. The Dreger et al. (2015) citation was also added Line 1 Platform. For example, a suitable paper would be that published (SRL early online publication for Jan 2015 issue), by Maechling et al Also please define acronyms (such as SCEC) the first time they are used, here and throughout the appendix. 790. Section j. 1, page J-1, For the sake of parallelism of construction, "and extending GMPE" Done Line 4 should read "and to extend GMPE" 791. Section J. 1 , Page J-1 , Please include additional text in this sentence lo reflect the use of Text has been added discussing the use of simulations for Line 5 simulated data by the Tl Team in Chapter 8 to select and assign analyzing ground motion Sammon's space and assigning weights to the selected models for DCPP (Figure 8.2-2). Also, please logic tree weights. A reference to Table 8.4-1 that defines add a summary. including tables, of the fault paramelers used to lhe parameters of the simulations used has been added. obtain the Chapter 8 simulated data, or reference the section where such a summary is provided. 792. Section J.1.1, Please explain whether the validation process uses a performance Text was added that explains the Tl Team's basis for using General measure that specifically evaluates the capability of simulation a HW factor derived from simulations methods in modeling hanging wall effects. If not, please explain the Tl Team's basis for trusting the HW factor derived from the simulations. 793. Section J.1.1, page J-The acronym "G&P" is given as "GP" elsewhere. Please use a Changed to GP throughout 1, 1"' paragraph of consistent acronym throughout the report. section, line 7 794. Section J.1.1, page J-In addition to the cited report, there is a peer-reviewed publication in The SRL special issue papers for all of the 5 simulation 1, 1"' paragraph of (SRL early online publication for Jan 2015 issue) by Dreger et al, methods have been referenced. The citation to Dreger et al.. section line 8 describing the BBP methods review, which could usefully be 2013, 2015 was moved to the following paragraph describing referenced here. The individual BBP methods each have individual the charge of the validation panel. peer-reviewed papers in the same SRL issue, and these should be cited as well. 795. Section J.1.1, Page J-There were issues attempting to open the URL from the link given in The link was removed since it would not be useful in print 1, 1st Paragraph of the appendix, although it worked when pasted into Microsoft Internet versions of the report. Section, Last Explorer. Please correct this link or indicate that it should be pasted Sentence into a web browser. 796. Section J.1.1, Page J-The pseudo spectral acceleration (PSA) referred to here is also The connection between PSA and RotD50, and a reference 1, 2nd Paragraph of referred to as RotD50 spectra elsewhere in the appendix. Please to Boore (2010) has been added. Section, 2nd Line choose a single term for PSA and use it consistently throughout the appendix and. preferably, the report and other appendices for consistencv. 797. Section J.1.1, Page J-Please provide references for the NGA-West1 project and the A citation to Goulet et al. (2015) was added since that paper 1, 2nd Paragraph of specific NGA-West1 GMPEs lhal were used for the Part B validation. describes the framework of the validation process. and the Section, 3rd Line definitions of the Part A and Part B validation tests, including how the NGA-West1 and NGA-West2 GMPEs were used. 798. Section J.1.1, Page J-Please provide a reference and/or link to the SCEC BBP workshop There is no proceedings, only the panel report and SRL 2, 1 "' Paragraph on proceedings. paper, which have been referenced page, 1st Line 799. Section J.1.1, Page J-Please indicate the specific appendix" that is referred to Done 2, 1" Paragraph on page, last line 800. Section J.1.1, Page J-This excerpt from the panel report needs clarification as indicated in Done 2, 2°d paragraph on subsequent comments, even if that requires a format different from a page, general verbatim quote. If one or more direct excerpts are nonetheless comment retained, please use quotation marks and indentation to distinguish paragraph-length quotations from the main text, and quotation marks to distinguish brief ones. 801. Section J.1.1, Page J-Please clarify this statement by replacing "residual" with "value of the Done 2, 2nd Paragraph on residual". page, 2nd Line 802. Section J.1.1, Page J-Please clarify the specific meaning of "performance" here and in Done 2, 2nd Paragraph on ltem4. page, 7th Line 803. Section J.1.1, Page J-Please clarify the meaning of the phrase "equally combining the The text was simplified by indicating the second assessment 2, 2nd Paragraph on absolute value of mean bias with the mean of the absolute value of criteria was the existence or lack of trends in bias within page, 2nd Numbered the bias". which is somewhat confusing as stated. discrete period bins. Item 804. Section J.1.1, Page J-Please explain why the period range 0.01 to 3 sec is deemed Text was added to remark that bias was observed to 2, 2nd Paragraph on acceptable for validating the finite-fault simulation methods. increase at periods greater than 3 seconds for most of the page, Last Line methods 805. Section J.1.1, page J-Please consider whether the parenthetical comment is necessary, Text has been clarified, and the parenthetical comment was 2, 3rd paragraph on and if so, whether the point being made could be clarified. The point removed as it is unnecessary. page, line 3 of the corresponding comment in the SCEC report was only to place the 0.35 natural log unit threshold in context, by comparing ii to the amplitude effect of a 0.1 unit magnitude shift in the limit of large distance and long period. 806. Section J.1.1, Page J-Please provide a reference for the "SCEC review report. Done 2, 3rd Paragraph on page, 6th Line 807. Section J.1.1, Page J-Please explain why the specific ranges of distances and magnitudes It was done to facilitate comparison. The text was modified 2, 4th Paragraph on were selected for the Part B validation. make that point. page, 2nd Line 808. Section J.1.1, page J-Please replace NGS-West 1" with "NGA-West1". Done 2, 4th paragraph on page, sentence 809. Section J.1.1, Page J-Please define these acronyms the first time they are used and Done 2, 4th Paragraph, 2nd replace the year with only the last two letters of the year to be Sentence consistent with how these acronyms are defined elsewhere throughout the report and appendices. 810. Section J.1.1, page J-The description of the upper and lower acceptance thresholds is The description was made more precise, and Goulet et al. 2, 41" paragraph on ambiguous. Please provide a more precise description. (2015) was cited. page, 3"' and 4'h sentences 811. Section J.1.1, Page J-Please indicate what "appendix" is being referred to. Done 3, 1st Paragraph on page, Last Line 812. Section J.1.1, Page J-Please provide the numerical values of the validation magnitude Done 3, 2nd Paragraph on range. page, 3rd Line 813. Figure J.1.1-1:, Page The bias threshold of 0.69 In units is not discussed in the text at this Text was that states it was the judgment of the SCEC J-4, Caption, 3rd Line point in the appendix. Please define why this threshold was selected validation panel that failure criterion for the simulation and how it is used when the figure is first discussed in the text. methods should be a bias threshold of 0.69 In units 814. Figure J.1. t-2:, Page The stated factor of 1. 15 applies to extending the maximum value Done J-5, Caption, 4th Line but not the minimum value. Please indicate what factor (less than one) was used to extend the minimum value. 815. Section J.2.1, Page J-Please define the terms and units in the magnitude-area scaling Done 6, 1st Paragraph of relationship of Leonard (2010). section, Last Line 816. Section J.2.1, Page J-Please replace "Graves and Pitarl<a" with "G&P" to be consistent Done 6, 2nd Paragraph of with the use of this acronym elsewhere throughout the report and section, 2nd Line appendices and use it consistently throughout the appendix. which also sometimes refers to G&P as GP. 817. Section J.2.1. page J-Please correct the extraneous words "A of' at the beginning of the Done 6, paragraph 2 of last sentence of the section. section, line 4 818. Figure J.2. t-1, Page Please also show the M7 scenario on this plot and indicate what dip The dip was added to the caption. The M7 case used J-7 angle is used to make the plot. different stations and cannot easily be added. 819. Section J.2.1, Page J-Please explain why there is no dip variation for the M 7 scenario. Text was added for the reason the number of M7 scenarios 8, Table J.2.1-1 was limited. 820. Section J.2.2, page J-Please provide a reference to the report section where the precise Done 9, paragraph 1. line 1 definition of a "complex" rupture scenario. as used in this project, is given. 821. Section J.2.2, page J-Please consider whether the reference to personal communication is Done 9, paragraph t, line 2 appropriate in this context. or whether it would be sufficient to note that the simplified scenarios were developed by the SSC project. 822. Section J.22, page J-The first sentence of the paragraph states that two complex Done 9, paragraph 1. line 4 scenarios were considered, but the list on this line contains three. including a Hosgri-Shoreline scenario that appears to be a splay scenario. Please check and make any appropriate corrections. 823. Section J.2.2, Page J-Please define the parameters "L" and "W" the first time they are Done 9, 1"' Paragraph, 6th used. Line 824. Section J.22, page J-The final sentence of the paragraph cites a personal communication Done 9, paragraph 1. last 2 for the approach to scaling the simulation parameters. Please rewrite lines this sentence to make it clearer that the Tl Team made the judgment to follow this approach. in light of its technical assessment of the alternatives and its consideration of the specific ways in which the simulations are used. 825. Section J.22, page J-Please add the missing word "that" in the phrase "except for." Done 9, 2n* of section, 2" line after equations 826. Section J.22, page J-Please clarify the intended meaning of the phrase "shortening a Done 9, 2" paragraph of fault". If, for example. it means shortening it relative to the length section, s'" and 6'" assigned in the SSC. that should be made explicit. Also clarify the lines after the intended meaning of the word "lowered" with respect to the northern equations endpoint [of the fault]. 827. Section J.2.2, page J-This sentence has several issues that should be corrected. ( 1) Done 10, 3'" paragraph of Please revise the awkward and ungrammatical (in this context) section (1" on page), construction "instead of attempting to predict realistic ground 1 sentence on page motion." (2) Please consider whether "realistic ground motion" is the right contrast to draw with "relative" ground motion (e.g., would "absolute" ground motion level be more appropriate?). (3) The caution against using the simulations for absolute ground motion levels appears to contradict the use of simulated ground motions in Chapter 8 to evaluate the common-form models Please rewrite this sentence to clarify the intended meaning and resolve the apparent contradiction. 828. Section J.2.2, page J-Later in this section, when splay scenarios are discussed, the Done 10. heading of 41" corresponding headings start with "Splay Scenario." The structure of paragraph of section the discussion would be more parallel and clearer if this heading (line 4 on page) were changed to "Complex Scenario 1: Hosgri-Los Osos." Please also include a section number for this and other similar subsection headings in the appendix, for easy reference and stylistic consistency with the other sections of the report. 829. Figure 2.2-1, Page J-Please show the surface projection of the inferred rupture plane of Done 10 the dipping reverse fault(s) in this and similar figures in the appendix. 830. Section J.2.2, page J-Please indicate (e.g., in the table caption) which (Hosgri or Los Done 10, Table J.2.2-1 Osos) is segment 1 and which is segment 2. 831. Section J.2.2, page J-Later in this section, when splay scenarios are discussed, the Done 11. heading at top of equivalent headings start with "Splay Scenario." The structure of the page discussion would be more parallel and clearer if this heading were changed to "Complex Scenario 2: Shoreline-San Luis Bay." 832. Section J.2.2, Page J-The length of the Shoreline fault plotted in this figure seems to be Done 11. Figure J.2.2-2 and much shorter than the length listed in Table J.2.2-2. Please check Table J2.2.-2 and revise as needed. 833. Section J.22, page J-Please indicate (e.g., in the table caption) which (Shoreline or San Done 11. Table J.2.2-2 Luis Bay) is segment 1 and which is segment 2. 834. Section J.2.3, page J-If the rupture scenarios were defined by the DCPP SSC Tl Team, Done 11. 1 ** paragraph, 1 *1 2 please indicate that explicitly. lines 835. Section J.2 3, page J-Please justify why the Tl Team made the judgment to select Text was added indicating that as validated the simulation 12. 211* paragraph of scenarios consistent with the Leonard relationships (e.g., is there a methods used source generators based on Leonard (2010), section (t'1 on page), connection with the way the models were validated?). and based on extensive discussions on the topics with lines 4 & 5 developers the Tl team made the judgment to select scenarios consistent with the Leonard relationships 836. Section J.2.3, page J-Please clarify which research goals were facilitated by the The research goal of how to mix GMPEs for complex and 12. 211* paragraph of modifications described and how the results ultimately feed into the splay cases was stated. section (t'1 on page), GMCmodel. Last 2 sentences of paragraph 837. Section J.2.3, page J-Please check whether the intended meaning would be better Done 12. 4'h paragraph of conveyed by using "each case" in place of "both cases." section, line 1 838. Section J.2 3, page J-Please explain the meaning of the phrase "scaled that slip by 30%," Done 12. 4'h paragraph of and give the justification for selecting the vaue 30% . section (3" on page), 3*d and sentences 839. Section J.2.3, page J-Please clarify whether "this slip" refers to the slip on the secondary Done 12. 4th paragraph of fault. section (3'" on page), 5*h line 840. Section J.2.3, page J-Please check whether this line should read "Los Osos-San Luis Bay Done 12. 5th paragraph of splay scenario" and correct if appropriate. section (3'* on page), Linet 841. Section J.2.3, page J-This sentence is confusing because of the ambiguity of the word Done 12. 5"' paragraph of "meet" in this context (i.e .. the word does not indicate which fault is section (3'" on page), cut off by the "meeting"). Please consider whether the intended Line 5 meaning would be better indicated if "meet" were replaced by "abut". 842. Section J.2.3, Page J-Please explain how exactly the process described in this sentence Done 13. 1st Paragraph. was done, which is somewhat confusing as stated. 2nd Sentence 843. Section J.2.3, page J-This sentence repeats nearly verbatim that of Section J.2.2, Page J-Done 13. paragraph 8 of 10, 3m paragraph of section. and the same comment applies and is section (41h on page) repeated here. This sentence has several issues that should be corrected. (1) Please revise the awkward and ungrammatical (in this context) construction "instead of a1tempting to predict realistic ground motion. (2) Please consider whether "realistic ground motion" is the right contrast to draw with "relative" ground motion (e.g., would "absolute" ground motion level be more appropriate?). (3) The caution against using the simulations for absolute ground motion levels appears to contradict the use of simulated ground motions in Chapter 8 to evaluate the common-form models Please rewrite this sentence to clarify the intended meaning and resolve the apparent contradiction. 844. Section J.2 3, page J-The phrase "Complex Scenario 2" should read "Splay Scenario 2". Done 14, heading following Table J.2.3-1 845. Section J.2.3, page J-"Shoreline-San Luis Bay splay" should read "Los Osos-San Luis Bay Done 14. 1 *1 line after the splay". Please correct. heading 846. Section J.3, Page J-Please indicate if "spectra" refers to Fourier amplitude spectra or Done 15, 1st Paragraph, 4th PSA spectra or both and whether the RotD50 component applies to Bullet Item, Last Line PSA here and elsewhere throughout the appendix. Nole a previous comment to use a consistent definition for the PSA spectral values referenced throughout the appendix and to define the term "RotD50" the first time it is used. 847. Section J.3.2, Page J-Please explain what an SRF file is the first time the term is used. Done 16,Second Paragraph, Line 3 (Item 2) 848. Section J.3 2, Page J-Please explain what each of the "two pieces" of the SRF file Done 16, 3rd Numbered represents. Item 849. Section J.3.2, page J-Please use some alternative language in place of the personal Done 16, paragraph 3 of pronoun "I" in order to better reflect the Tl Team's collective section ( 1 *1 paragraph intellectual ownership of the model and maintain stylistic consistency after the list), Line 2 throughout the report. 850. Section J.3.2, page J-The meaning of this sentence is not clear. Please rewrite it to clarify Done 16, S'h paragraph of how ExSim solutions for the component segments were combined. If section (last the GP and SDSU simulations were applied in some way as part of paragraph on page). the ExSim procedure, the explanation should clarify what "properties" 211* sentence GP and SDSU provided. and how those properties were matched by the ExSim procedure. 851. Section J.3.2, page J-The time delay appears to represent the delay between initial Done 16 51" paragraph of rupture on the initial segment and arrival of that rupture at the section (last on page). junction of the fault segments. If that is the case. the relevant velocity last sentence would be the rupture velocity, not the S wave velocity Vs. If this reasoning is correct, please modify the notation "Vs" to be more appropriate for representing a rupture velocity instead of the wavespeed If it is not, please clarify. In either event, please rewrite this sentence to be explicit about what was done. That is, instead of using the ambiguous qualifier "based off', state explicitly what was calculated to obtain the delay time. 852. Figure J.3.2-1, Page Please describe the meaning of the colored shading on these and Done J-17 similar plots in the appendix. 853. Section J.3.2, page J-The use of quotation marks on "factors" is not appropriate (it is not a Done 17. 6"' paragraph of meta-reference to the word "factors"), and because the quantities section (1"1 on page), defined here are used repeatedly in an important role in this section, line4 the clarity would be significantly improved if they were given a distinctive name, with the name then used consistently throughout the discussion that follows. 854. Section J.3.2, page J-The factors obtained from rules for defining GMPE input parameters Done 17. 6'" paragraph of appear to be different quantities than the factors defined earlier in the section (1'1 paragraph paragraph, and the use of the same term "factor" for both (especially on page), line 9 since the term "factor" is not distinctive to begin with) is a source of confusion. Please clarify the discussion later in the chapter by giving the ratios obtained from these GMPE rules a distinctive name, different from that used for the simulation ratios. 855. Section J.3.2, page J-The characterization of the process as "already quite convoluted" is Done 18, 7'h paragraph of redundant. Please consider deleting that phrase In fact, the entire section (1'1 on page), sentence could be replaced by beginning the subsequent sentence 1 sentence with "For complex scenarios with both a strike-slip and reverse component, it was required." 856. Section J.3.2, page J-Please elaborate on what "separated" means in this context and how Done 18, 7'h paragraph of this separation is conducted and the results verified section (1"1 on page), last sentence 857. Section J.3.2, page J-Please explain what this paragraph contributes to the description or Done 18. 8"' paragraph (2r.d evaluation of the GMC model or delete it. on page) 858. Figure J.3.3-1, Page Please define the acronyms used in the legend of the plot. Done J-19, Caption 859. Section J.3.3, page J-This sentence is similar to that of Section J.3.2, Page J-16 5'" Done 20. 3rd paragraph of paragraph of section (last on page), last sentence. and the same section (1"1 on page), comment is repeated here. The time delay appears to represent the line 6 delay between initial rupture on the initial segment and arrival of that rupture at the junction of the fault segments. If that is the case, the relevant velocity would be the rupture velocity, not the S wave velocity Vs. If this reasoning is correct. please modify the notation "Vs" to be more appropriate for representing a rupture velocity instead of the wavespeed. If it is not, please clarify. In either event, please rewrite this sentence to be explicit about what was done That is, instead of using the ambiguous qualifier "based off', state explicitly what was calculated to obtain the delay time. 860. Section J.3.3, page J-Please remove the inappropriate quotes from "factors" (but see Done 21. 4'" paragraph of previous comment recommending use of a more distinctive section (t'1 on page), terminology), and correct the redundancy in the phrase "we 1" and z*d lines on computed factors computed for." oaae 861. Section J.3 2, Page J-If "plant site" refers to the "DCPP site". please replace the former Done 2t. 1st Paragraph. with the latter. If the intended meaning of the phrase is different, 2nd Line please supply the intended meaning. 862. Section J.4, Page J-Please avoid the use of the term "proponent models" here and Done 21. Section Heading elsewhere throughout the appendix. which can be confused with the term proponent models and/or methods proposed by Proponent Experts, as defined in the SSHAC guidelines. 863. Section J.4, Page J-Since much of the text in this section is virtually the same as the text Done 21, General in Section 6.7, please refer to the comments on Section 6.7 for revising the similar text and figure captions in this section. 864. Section J.4, Page J-Please clarify whether this always leads to an increase in ground Done 22. 211* Paragraph of motion. section, Line 2 865. Section J.4.1, page J-Please consider whether the intent of this line would be better Done 23. 1 paragraph, line conveyed by the phrase "Four methods were evaluated for 1 computing" in place of the phrase "four methods were used to comoute." 866. Section J.4 1, page J-Please define the variables used in the equation. and. for Done 23, 2"' paragraph of consistency with other parts of the report, change "Sa" to "PSA." section, unnumbered equation 867. Section J.4.1, page J-The quotation marks on "average" are inappropriate. If the word Done 23. znc paragraph of "average" without quotes doesn't communicate the intended section, 3'" line after meaning. please use a word that does (e.g., "representative"). the equation 868. Section J.4.1, page J-24. 4'" paragraph of section (t'1 on page), Please define the variable "R." Done line 2 869. Section J.4.1, page J-Please define the variables used in the equation and clarify the Done 24, 4*h paragraph of nature of the summation. section ( 1 *1 on page), unnumbered equation 870. Section J.4.1, page J-Please consider whether the intent of this sentence would be better Done 24. 1 line after the conveyed by the phrase "The GMPEs are then applied using" equation instead of the phrase "The GMPEs use the", since the latter could be misinterpreted to imply that the subsequent part of the sentence is a defining feature of the GMPEs. 871. Section J.41, page J-The meaning of this line would be clearer if the sentence began by Done 24, last paragraph of indicating explicitly that the method applies the GMPEs with the section, 1*1 line predictor variables as defined in the balance of the sentence. Please clarifv this line. 872. Section J.42, Page J-Please revise the sentence so that it is clear that "50 degree" refers Done 24. 2"" paragraph of to the fault dip. section, line 1 873. Section J.4.2, page J-Please specify that "method refers to "ground motion simulation Done 25, paragraph 4 of method." The distinction is necessary because four methods for section (last on page). assigning GMPE predictors are also discussed and need to be line 1 differentiated from the numerical ground motion simulation methods. 874. Section J.4.2, page J-Please clarify this line by specifying that the spectra are obtained Done 25, paragraph 4 of from the GMPEs using each of the four different methods for section (last on page), assigning predictor variables. line 2 875. Figure J.4.2-1, Page Please correct the acronyms in the plot legends to confolTl'l with Done J-26 those used elsewhere throughout the report and appendices (i.e., "ASK14" instead of "ASK'13). Also, please check the accuracy of the "grey" curve that has a nearly "flat" zone from 0.5 to 1 Hz and. if correct. explain why this GMPE is used given such strange behavior. 876. Section J.4.2, page J-There are no gray lines in Figure J.4.2-3, nor are the colors of the Done 26. paragraph 5 of section (1"1 on page), dots explained. Please correct. line 2 877. Section J.4 2, page J-As noted in an earlier comment, the discussion of complex and splay Done 26, paragraph 5 of adjustments would be easier to follow if the simulation factors and section (t'1 on page), GMPE factors had different, distinctive names used consistently line 2 throughout the chapter. Furthermore, the GMPE factors have not been explicitly defined, and although the meaning can be inferred from the context pretty well, it would be clearer if they were explicitly defined when the concept was first introduced. Please consider introducing better terminology and more explicit definitions for these "factors". 878. Section J.4.2, page J-Figure J.4.2-3 does not appear to show what is claimed, maybe Done 26. paragraph 6 of because the gray lines mentioned in the text and caption are not section (2"d on page). visible. line 2 879. Figure J.4.2-3, Page There are four GMPE methods but six differently colored dots. Done J-28 Please indicate what the different colored dots represent both here and in similar plots in the appendix. 880. Section J.4.2, page J-The statement that the magnitude is based only on the area of the Done 29. 9"' paragraph of Los Osos fault in Method 1 for the Hosgri-Los Osos scenario is section (1"1 on page), confusing. The problem is that the statement can be misinterpreted last sentence to suggest that the magnitude of the scenario changes depending upon the method of ground motion calculation. However, what actually changes is just the predictor variable M that is input to the GMPE. Please keep this distinction clear in the discussion. 881. Section J.4.2, page J-Please revise this sentence so that it is clear "70 degree" refers to Done 29, 10'" paragraph of the fault dip section (2"d on page). Line 1 882. Section J.4.2, page J-This figure citation appears to be in error. as this is no Figure J.2.2-Done 29, 10'" paragraph of 3. Please check whether the citation should be to Figure J.2.2-2 and section (2"d on page). make the appropriate correction. Line 2 883. Section J.4.2, page J-Please check whether the cited table should be J.2.2-2 instead of Done 29. 10111 paragraph of J.2.2-3. section (2"d on page). Line 3 884. Section J.4.2, page J-The word "one" just before the comma is ambiguous. Please clarify Done 29, 11'" paragraph of whether the meaning is "all periods except for one period" (in which section (last on page), case indicate which one), or if ii is "all periods except for T= 1 last line on page second." 885. Section J.4.2, page J-The gray lines are not visible in Figure J.4.2-6, nor are the symbols Done 30. 13111 paragraph of explained. Please correct this. section (2"d on page). Line 1 886. Section J.4 2, Page J-If this sentence is intended to refer only to Methods 2. 3, and 4, but Done 32, 2nd Paragraph, not Method 1, please replace the phrase "each of these methods Last Sentence with "each of Methods 2, 3, and 4." 887. Section J.4 2, Page J-Please expand this paragraph to summarize quantitatively the Done 33. 1st Paragraph on justification for accepting Method 1 for the complex scenarios. page, 1st Sentence 888. Section J.4.3, page J-Please cite a published report or journal article for the observation Issue resolved in Rev.2 34. 4'" paragraph of that the GMPEs have stronger distance saturation than the ExSim section (1'1 on page), model. Then the result mentioned here (regarding ExSim peak line 5 amplitudes) can be stated as a consequence of that fact (perhaps one pointed out by Dr. Atkinson to the Tl Team), rather than something to be taken purely on the authority of an unpublished comment by Dr. Atkinson. 889. Section J.4.3, Page J-Please reference the figure where the comparison referred to in this Done 35, 2nd Paragraph on sentence is shown. page, 1st Line 890. Section J.4.3, Page J-Please explain quantitatively the basis for the statement that Done 37. 2nd Paragraph on "Overall, GMPE Method 1 RotD50 spectra provide the best page, Last Sentence agreement with the simulation results". 891. Section J.4.3, page J-Please reference the figure where the comparison referred to in this Done 39. 1 paragraph on sentence is shown. page, 1*1 line 892. Section J.4.3, page J-In Figure J.4.3-6, the colors are not explained nor are the panels Done 39, 1" paragraph on labeled nor explained in the caption Please correct this. page, last line 893. Section J.5.1, Page J-The magnitude ranges specified in this sentence disagree with those The magnitude ranges have been corrected. Simulations 41. Last Sentence of specified elsewhere in the report and also disagree with those were used to a minim um magnitude of 6.0. ASK 14 and section described in the publications of ASK14 and CB14 Please revise as CB14 both use magnitude tapers from M<6 5, which tapers needed. to no effect for M <= 5.5. 894. Section J.5.2, Page J-Please clarify that only the NGA-West2 HW terms are used and that Yes this is true 41, 3rd Paragraph of these terms are applied to the footwall model developed from the Section, 1st Line simulations. 895. Section J.5.2, page J-Please distinguish whether the processing described in this Clarified that the processing was on the simulation PSA. 41. 3'0 paragraph of sentence refers to the GMPE estimates or the simulation estimates. section, 2"d sentence Also clarify that the phrase "extent of the rupture plane" means extent of the surface projection of the rupture plane. 896. Section J.5 2, page J-Please either provide the functional form used or a reference to the An equation was added. 41. 3'" paragraph of report section or publica1ion where it is provided. section, 3'" sentence 897. Section J.5.2, Page J-Instead of stating that the comparisons are similar, please include Since this figure is just demonstrating that we can reproduce 41. 3rd Paragraph of the comparisons with CB14 and CY14 on Figure J.5.2-2 to show the the GMPE with the approach used to analyze the simulated Section, Last robustness of the NGA-West2 GMPE HW terms. motions it is not really necessary to show all of the model-to-Sentence model comparisons. Instead we removed the sentence regarding CB14 and CY14. 898. Section J.52, Page J-The SDSU simulations do not show a HW effect at M5.5 and M6.0. Text has been added discussing that while it is true the 41. 4th Paragraph of This would imply 1hat there is some uncertainty in whether there is a SDSU method shows lower HW amplification for the shown Section, 2nd HW effect at small magnitudes. Please discuss how this uncertainty scenario, other fault dip and ztor cases indicate that HW Sentence is factored into the HW model or reference where in the report such amplification is seen in all three simulation methods. a discussion is provided. 899. Section J.5.2.3. Page Instead of stating that the results are similar, please include the Figure J.5.2-4 was added to shows the comparison between J-42. 1st Paragraph. results from CB 14 to show that the results are similar. CB14 and the simulations 2nd Sentence 900. Section J.5 2, page J-The statement that the distance taper is small is ambiguous and Poor choice of words. Small was referring to the lack of 42, 5*h paragraph of confusing. It appears, in fact, that the distance tapering factor is near tapering, but as you point out that term is in fact larger section (2"" on page). unity, not near zero. Please clarify. valued. The text has been clarified. znc lo last sentence 901. Section J.5.2.3, Page Please also clarify that the development of the HW term for the GMC The development of the HW model has been now moved to J-42. 3rd Paragraph, model is given in Appendix K Chapter6 Last Sentence 902. Section J.5.2, page J-Please reconsider the categorical statement made here that the M The statement regarding the severity of the magnitude 42. 6'h paragraph of taper of the NGA-West2 GMPEs is too severe. There are several tapers was removed and the focus changed to reiterating section (3'c on page), such GMPEs. Do you mean to refer to all of them, to all that use that the simulations show that hanging wall effects may be 2"" sentence Rrup as the distance predictor, or to just ASK 14 and CB 14? Why important to magnitude as low as 5.5 would CY14 be judged as too severely tapered, given the results in Figure J.5.2-4? Please clarify. 903. Figure J.5.2-2, Page Please expand this figure caption to better describe the plots that The caption has been expanded. J-44 are shown in the figure. 904. Figure J.5.2-3, Page Please indicate that the colors refer to the plus symbols shown on Done J-44 this and similar plots in the appendix. 905. Section J.6.1, page J-The language used here could imply that 1 D models are not yet fully The sentence has been changed stating that Green's 47. 1*1 paragraph of implemented. Please clarify by revising this line functions for 1D models are being used by the BBP. section, line 1 906. Section J.6.1, Page J-Stochastic simulation methods often employ a set of site-Text has been added clarifying the velocity model 47. 1st Paragraph, 4th amplification factors that are developed from a 1D velocity and constraints on the BBP methods. A minimum Vs=863 mis is Sentence density crustal structure, typically using the Quarter-Wavelength used EXSIM does use calibrated geometrical spreading and Method. Please clarify whether or not that is the case with the attenuation operators. As implemented the methods are versions of EXSIM, G&P and SDSU that are available on the BBP, simulating rock motions and they are not subsequently all of which use a stochastic method (though only for the adjusted for site effects. computation of ground motion at frequencies above 1 Hz in the case of SDSU and G&P). If it is. please indicate what crustal structure is used and how similar it is to the velocity models described in this section. 907. Section J.61, Page J-Please indicate the referenced features on the velocity profiles Done 47, 2nd Paragraph, shown in Figure J.6.1-1. 1st and 2nd Numbered Items 908. Section J.6.1, page J-Please indicate whether the recording at PKD was affected by any Done 47. 3*d paragraph of significant, known 3D wave propagation effects. section, line 2 909. Section J.6.1, Page J-Please provide units for the values 286, 93, and 62. Done 47. 3rd Paragraph. 3rd Line 910. Section J.61, page J-The cited figure shows synthetic ground motion, not velocity models, Done 47, 3'" paragraph of so "GIL7 velocity model" should read "synthetics calculated with the section, line 7 1D GIL? velocity model." 911. Section J.6.1, page J-Please provide a reference (either to a publication or to a report Done 47. 3*d paragraph of section) supporting the asserted appropriateness of the GIL7 velocity section, line 8 model for the central coast ranges. 912. Section J.61, Page J-Please define the term "PL type wave" the first time it is used, or cite Deleted since this level of detail is not needed. Long-period 48, 1st Paragraph on a reference where the term is defined. P-wave suffices. page, 2nd Sentence 913. Section J.61, page J-This paragraph (and to some extent the preceding one as well) Fair comment GIL7 is considered more appropriate for two 48. 211* paragraph on seems rather awkward and its purpose unclear. The discussion reasons: 1) it is based on modeling of seismic waveforms page appears to be treating GIL7-based synthetics as targets for the BBP and not just P-wave arrival times, thus it includes direct Norcal-based simulations to match, giving the GIL7-based synthetics information regarding shear wave velocities, and 2) it is now similar status to that of the observed waveforms. Why would not all commonly used by the BSL in routine analysis. which has of the models deserve comparison with the observations on an equal proven effective in source parameter recovery. footing? Please consider whether it would be less confusing, and Nevertheless, the suggested rephrasing more clearly makes more to the point, to simply state that, on balance, simulated in the intended point and the text has been modified. waveforms based on the BBP Norcal profile agree with the key features of the observed waveforms at least as well as those based on alternative available 1 D models. 914. Section J.6.1, Page J-Please avoid the use of the subjective term "very good agreement Done 48. 2nd Paragraph, and instead provide a quantitative measure of the agreement and 4th Line why that measure of agreement is acceptable. For example, it appears from Figure J.6.1-3 that the synthetic seismogram amplitudes are as much as a factor of 2 higher than the observations. 915. Section J.6.1, page J-The clause beginning with "although" confuses the issue, making it The point that the use of the 1 D velocity model in the 48. 3'd paragraph on harder to understand the point being made. The use of the 1 D model simulations is justified is made clearer. Future page, 1*1 sentence is either justified by the tests cited or it is not. The fact that there improvements in methods including 3D structures will likely could be an even better option for future use is interesting and worth improve the simulations, but that issue is not immediately mentioning as a final comment, but it does not address the question relevant to this report and has been deleted. of whether the current use of the 1 D models is justified. Please rewrite this sentence to summarize the Tl Team evaluation of the model actually being applied. Ideas (like 3D modeling) for future improvement may be offered, but in a way that makes it clear that the evaluation is not contingent on those improvements. 916. Section J.6 2, page J-Please provide a specific reference to the discussion or presentation Done 50, 1" paragraph of where the stated "remark" from Workshop 2 can be found, and section, line 1 indicate the period range implied by "long-period" in this context. 917. Section J.62, Page J-Please clarify if the comparison is between simulated ground The comparison is between simulated motions and fault slip 50, 1st Paragraph, motions or between simulated and observed ground motions. only. There is no comparison with observations. 2nd Sentence 918. Section J.6 2, page J-The line described parenthetically as red appears as a black line in Corrected 50, 1" paragraph of Figure J.6.2-1. Please correct this description so that the text and section, line 7 figure are consistent. 919. Section J.6.2, page J-Please clarify that the comparison is between simulated ground This is the correct interpretation, and the text has been 51. 3rd paragraph of motion and synthetic slip models used to compute those ground clarified. section (2"" on page) motions, if that is the case. If that is not the correct interpretation, please explain. 920. Section J.62, page J-51, 3'" paragraph of section (2"" on page), Please explain what the word "maximum" refers to. Done Line 2 921. Section J.6.2, page J-This paragraph and some of the subsequent discussion is difficult to The first paragraph has been rewritten to clarify the 51, 4th paragraph of follow. Please consider prefacing ii with some clear statement of the motivation of the section. section (3'" on page) purpose of the analysis, and following it with a clear summary statement. For example, if the purpose is to assess (using numerical simulations) whether near-fault. long-period ground motion amplitudes mirror the empirically-observed high variability of static slip values. ii would help if that were stated explicitly. If the conclusion is that ground motions do not mirror that high variability, because they are better correlated with broader spatial averages of slip (which are less variable than point values) than they are with nearest-point slip values, it would be useful to summarize that conclusion in explicit terms. 922. Section J.6 2, page J-Please consider whether the intended meaning of this line would be Done 51, 4*h paragraph of clearer if the phrase "from nearby shallow regions of the fault" were section (3'c on page), restated as "from slip on shallow portions of the fault that are nearby. line 3 but not necessarily nearest. to the site," or some similar phrase that highlights the essential idea that the nearest point on the fault does not necessarily dominate the ground motion amplitude. 923. Section J.6.2, Page J-Please explain the meaning of the term "radiation sensitivity" and Done 51. 3rd Paragraph on define the tenns "FP" and FN" the first lime they are used. page, 7th Line 924. Section J.6.2, Page J-Please clarify that the "given site is the location of LCN. Done. This was meant to be general so the phrase ". in this 51, 3rd Paragraph on case LCN" was added. page, Last 2 Lines 925. Section J.6.2, page J-This paragraph is difficult to parse and its purpose is not very clear. Changed to added. The point is that in the validation LCN is 51. 511' paragraph of Please rewrite to make that purpose clearer, and also please state an actual stations that was used where we have simulation section (4111 on page). what is meant by the phrase "pseudo station." results, and the other 13 are simply used to compare different measures of the slip model to document both along strike, and source realization variability in slip. 926. Section J.6.2, page J-Please include plots of variation of static displacement, peak FP and Done. Also the plots for radiation pattern averaged slip were 51, 7'h paragraph of FN displacement, and SD with the nearest surface slip incorporated in a new composite figure J.6.2-5 and the section (61h on page), original figures J.6.2-5 -7 have been deleted. Line 1 927. Section J.6.2, Page J-Please clarify what "correlations" are being referred to in this We added "simulated" to clarify that the comparisons or 51, 6th Paragraph on statement. correlations are between the simulated ground motions and page, 3rd Line the various measures of fault slip. 928. Section J.6.2, Page J-Please avoid the use of the subjective statement quite good" and See answer below 51, 6th Paragraph on page, 5'h line replace it with a quantitative measure of the goodness. 929. Section J.6.2, page J-This sentence is ambiguous. One possible interpretation is that the Section and sentence has been rewritten 51, 7'h paragraph of static displacement and FP peak displacement correlate better with section (6'h on page). local fault slip than does the FN peak displacement. An alternative 3*d sentence interpretation is to replace "than does" with "than with". Please make changes to resolve this ambiguity. 930. Section J.6.2, page J-There is a reference here to "local fault slip." Please distinguish. Done 51. 7111 paragraph of here and elsewhere in this section. between point-wise (or nearest-section (6111 on page). point) values of local fault slip versus localized averages. The last line on page distinction is important because there is no real question that some sort of local average is going to correlate with low-frequency ground motion. The point of the section appears to be to indicate just how localized that control is, and therefore how much variability it introduces. 931. Section J.6.2, Page J-Please clarify what the "geometric mean" is taken with respect to. Done 60. 1st Paragraph on page, 1st Line 932. Section J.6.2, Page J-Please delete the subjective word well". Done 60, 1st Paragraph on page, 4th Line 933. Section J.6.2, Page J-Please complete the phrase "and that the range of the simulated Done. " ... motions spans that of the individual GMPEs." 60. 1st Paragraph on motions". page, Last Line 934. Section J.6.2, page J-Please resolve the ambiguity of the phrase "10s of source Done 60. B"' paragraph of realizations," which can be read as "1 O's of source realizations" or section (1"1 on page), "10 seconds of source realizations." last line on page 935. Section J.6.2, Page J-Please explain why the capture of the variability along the fault by Expectation is not the right word. The analysis shows that 61, 2nd Paragraph, the 50 realizations is expected. this is the case and the text has been modified to make that Last Sentence point 936. Section J.7, page J-Please ensure that all of the references that are cited are in the list Done 61 & J-62 of references and that all of the references are complete with up-to-date infonmation. For example, please update reference items 2. 8, 10 & 13 with complete publication information, and the missing references for Goulet et al. (2014) and Dreger et al. (2014) that were cited at the end of Section J. 1. 1. 937. Figure J.2.2-2, page Please add to the caption that "Shoreline" and "San Luis Bay" label Done J-1 t the rupture segments modeled in the simulation, and indicate their relationships to the Shoreline Fault and San Luis Bay Faull, respectively (e.g .. that they are simplified representations inspired by the Hosgri-Shoreline splay scenario?). 938. Figure J.4.2-2, Page Please add a label to the y-axis and indicate in the figure caption y-axis label provided J-26 that this figure is for complex rupture Scenario 1. This request also applies to Figures J.4.2-5, J.4.3-2, and J.4.3-5 939. Figure J.4.2-3, page The gray lines in this plot are not visible, and the meanings of the Done J-28 colors are not indicated (the latter also applies to Figure J.4.2-6, J.4.3-3, and J.4.3-6). Please correct. 940. Figure J.4.2-6, page The gray lines in this plot are not visible, and meanings of the colors Done J-32 are not explained. Please correct. 941. Figure J.5.2-3 & These figures use a different color scheme for the 3 simulations than Done Figure J.5.2-4, pages do earlier figures, which is confusing. Please use the same color J-45 & J-46 scheme for all figures for clarity. 942. Figure J.4.3-2, page Please label the plot axes. Done J-35; Figure J.4.3-5, Page J-39; and Figure J.6.1-1, page J-48 943. Figures J.6.1-2 and Please indicate the recording station in the caption. Done J.6.1-3 944. Figures J.6.2-5 Please explain the use of the factor Y:., and why it is absent in Done. These figures have been incorporated into the new Figures J.6.2-6 and J.6.2-7. Also please define the symbols and lines composite Figure J.6.2-5. in the plot and reword the caption to be more meaningful in this and similar figures in the appendix. APPENDIX K Hanging Wall Model 945. General There are many parameters, terms, and acronyms used throughout The appendix is now integrated into the Chapter 6, so the appendix without first being defined As a reiteration of previous several of the acronyms are defined already comments on various chapters and appendices in this report. please ensure that all of the parameters, terms, and acronyms used in this appendix are defined in a list prior to their use. Otherwise, they will need to be defined the first time they are used in each chapter and appendix. 946. General All of the figure captions are short and cryptic. Please expand the Done figure captions to completely describe all of the curves shown on the plot and the values of any variables that were used to plot them. 947. Section K.1, Page K-Please explain the meaning of the term "HW factor" the first time it is Done 1, 1st Paragraph of used (e.g., indicate how is it calculated from each GMPE). Please Section, 1st Line also indicate who derived the HW factor model in place of the statement "The HW factor model was derived". 948. Page K-1, First Please include a brief summary of the ranges of magnitude and Ztor Paragraph and site locations (Rx) for which HW effects are of importance to the GMCmodel. 949. Section K.1, Page K-The dip of the rupture plane is a fifth aspect of the ASK14 and CB14 Done 1, 1st Paragraph of HW terms that has been overlooked. Please mention the dip of the Section, 2nd Line rupture plane as an additional aspect of the ASK 14 and CB 14 HW terms. 950. Section K.1, page K-Please replace "rupture place" with "rupture plane." or, perhaps Done 1, 1 "' paragraph. line 3 more precisely, with "rupture surface." 951. Section K.1, Page K-Please define the term "taper," as it applies in this context, the first Done 1, 1st Paragraph of time it is used. Section, 5th Line 952. Section K.1, Page K-Please indicate which of the five aspects of the HW terms of ASK14 Done 1, 1st Paragraph of and CB14 are also present in the CY14 HW term before describing Section, 7th Line the differences in this latter term. 953. Section K.1, Page K-Please insert the missing comma after the word "magnitude" al the Done 1, 1" Paragraph, Line end of line 7. 7 954. Section K 11. Page Please avoid the use oflhe subjective term "significant" and instead K-1, 1st Paragraph of provide a quantitative metric to describe these differences. Please Section, 6th Sentence also summarize the observed differences among the HW terms of the NGA-West2 GMPEs 955. Section K 11. Page Please indicate ifthe HW factors given by Eq. (K-1) are arithmetic or Done K-1, Eq. (K-1) logarithmic and exercise care when referring to this factor elsewhere throughout the appendix by indicating if it is the multiplicative factor or the log factor that is being referenced. 956. Section K.1.1, Page Please justify the assumption that the HW effect is largely geometric Discussion added in Chapter 6 K-2, 1st Paragraph on and show why, based on this assumption, that the surface projection page, 2nd Sentence of the rupture plane is directly related to the cosine of the dip. 957. Section K 11. page Please add a comment noting that the formulation alluded to was That's not correct. K-2, 1 "1 paragraph of introduced to fit numerical simulations, if that is the case. section (t" on page), 3*d sentence on page 958. Section K. 1.1, Page Please briefly describe the HW study and model developed by Out of the SWUS GMC scope K-2, 1st Paragraph, Donahue and Abrahamson (2014). 5th Line 959. Section K 11. page Please clarify the purpose of the expression "with the effect based Entire section absorbed in Chapter 6, with greater K-2, 1 "1 paragraph of on the GMPE." It seems to be covered already by the text in the consistency among all the parts section (1" on page), beginning of this sentence. Line 7 960. Section K.1.1, page Please justify the Tl Team's decision to neglect HW effects at Based on GMPEs scale K-2, 1" paragraph of periods longer than 3 seconds, in light of the interpretation of Chang section (1"' on page), et al. (2004, BSSA, vol 94, p. 2186) that there are large HW effects 2"" to last sentence at long period (T = 2s and 4s) for the 1999 Chi Chi earthquake. This may entail showing plots of long-period (T>3s) residuals for the ChiChi earthquake computed with respect to the candidate GMPEs. 961. Section K. 1.1, Page Please define the meaning of "central model" (e.g., is it the median Clarification added in Chapter 6, in the appropriate section K-2, 1st Paragraph on or mean HW factor. which depends on whether the model is on the page, 12th Line factor itself or the log of the factor). 962. Section K. 1.1, page Please check whether this line should say "K-1 through K-4," and Based on GMPEs scale K-2, 1" paragraph of section (1"' on page), correct if appropriate. last line 963. Section K 11. Page Please define the term "base moder the first time it is used. Done in Chapter 6, where Appendix K was integrated K-2, 2nd Paragraph, 1st Line 964. Section K 11. Page Please further explain (here or preferably in Chapter 6) the necessity Explanation added (so we can randomly pick one HW K-2, Second for equal-probability sampling of the HW factor models, in lieu of branch) Paragraph of section other variance-preserving sampling schemes (un-equally weighted) (and 2"C on page) such as those widely used to represent the epistemic uncertainty of other PSHA inputs. 965. Section K 11. Page Please clarify whether it is the arithmetic HW factor or the log HW Clarification added in Chapter 6, in the appropriate section K-2, 2nd Paragraph. factor that is assumed to be normally distributed. 3rd Line 966. Section K.1.1, Page Please explain the meaning of "fitted model" Explained in chapter 6 K-2, 2nd Paragraph, 5th Line 967. Section K 11. page Please define the term "epsilon" the first time it is used. Done K-2, 2"d paragraph of section and page, line 7 968. Section K 11. Page Please explain how the "probability weighted mean epsilons" were Done K-2, 2nd Paragraph. calculated. 7th Line 969. Section K. 1.1, Page Please explain why "equally weighted factors" were used when they Done K-2, 2nd Paragraph. were derived from different probability ranges of a normal 12th Line distribution. 970. Section K. 1.1, page Please check whether this sentence should say "K-1 through K-4, Done K-2, 2"0 paragraph of section (2"d on page). and correct if necessary. 211* to last sentence 971. Section K.1.1, Page Please avoid the use of the subjective term "good" and provide a Explained in chapter 6 K-2, 2nd Paragraph, quantitative metric for describing the goodness of the observed 14th Line comparison. This applies to this instance and several other instances throughout the appendix where "good" is used to describe the goodness of a comparison. 972. Section K.1.1, Page Please explain why it is acceptable for some of the GMPE HW Explained in chapter 6 K-2, 2nd Paragraph, factors to fall outside the bounds of the five proposed HW models. 14th Line 973. Section K. 1.2, Page Please summarize the analysis from Appendix J to the extent Explained in chapter 6 K-2 necessary to form a readable and understandable review of the Tl Team's treatment of the magnitude taper issue. If, in that treatment. the magnitude-dependence carried implicitly by Eq K-1 is deemed reasonable based on the good agreement with simulated HW effects at M 5.5, please state this explicitly. 974. Section K 1 2. Page Other reasons why the ASK14 and CB14 HW models applied a Done K-2, 1st Paragraph of magnitude taper to make the HW factor go to zero at M5.5 was the Section, 2nd Line lack of any empirical data or numerical simulations to support a HW effect at smaller magnitudes. Please include these reasons in support the NGA-West2 developers "judgment" that is stated as the reason for the taper. 975. Section K.1.2, page Please give a specific magnitude range for the phrase "moderate Done (chapter 6) K-2, 1 paragraph, magnitudes". Line 3 976. Section K 1 2. Page The ground motion simulations described in Appendix J showed that K-2, 1st Paragraph of one of the three simulation models (SDSU) did not predict strong HW Section, 2nd effects at small magnitudes. except at relatively small depths (e.g., Sentence Ztor = 2 5 km) or relatively small dips (e.g .. dip= 30 degrees). Please indicate how this uncertainty is incorporated in the HW factor model presented in this appendix. 977. Section K.1.3, page Please indicate that the site angles of 90 and 0 degrees mentioned Done K-3, 3"' and 4*h in these sentences are measured relative to fault strike. sentences of section 978. Section K.1 3. page Please explain how the assertion that CB14 and CY14 "allow for a Figure corrected, and discussion modified accordingly K-3, lines 4-6 on page smoother transition as a function of location around the rupture" is consistent with the fact that (according to Figure K-5) CB14 has a step as Rjb approaches zero along the strike direction This step behavior actually appears to be a sharper transition than that of any of the other HW models in Figure K-5, and would seem inconsistent with this assertion. 979. Section K.1.3, Page Please avoid the use of the subjective term "well," which in this case Explained in chapter 6 K-3, 1st Paragraph, can be deleted without impacting the statement. 6th Line 980. Section K.1.3, Page Please indicate that the proposed Rjb taper model given by Eq. (K-Done K-3, 1st Paragraph, 2) is shown in Figure K-5. Eq. (K-2) 981. Section K.1.4, Page Please avoid the use of the subjective term "significant" and instead Explained in chapter 6 K-3, 1st Paragraph of provide a quantitative metric to describe the observed differences in Section, 3rd Line the trends. 982. Section K.1.4, Page Please indicate that the proposed Ztor taper model given by Eq. (K-Done K-3, 1st Paragraph of 3) is shown in Figure K-6. Please also show the equation for the Section, Eq (K-3) complete HW factor model that combines all three equations for completeness (also note whether the complete model is the arithmetic or log value of the HW factor 983. Section K 2, page K-Please provide a specific reference to the section(s) of Appendix J Not needed anymore because Appendix K was incorporated 3, 1 "' paragraph of where the hanging wall analysis is presented. in the main report section, 1"' sentence 984. Section K.2, Page K-Please provide and discuss the development of the equation that Done 3, 1st Paragraph of was used to define the footwall simulations. Section, 3rd Line 985. Section K.2, Page K-Please clarify who did the simulations described as "were Done 3, 1st Paragraph of simulated". Section, 5th Sentence 986. Section K.2, Page K-Please provide similar plots to those in Figure (K-1 t) for a range of Three new figures were added to show Ztor and dip 4, 1st Paragraph, 2nd magnitudes, dips, and depths to fully document the comparison with sensitivity for the M 5.5 and MG.O cases. The original figures Sentence the simulations, or revise Figures (K-1) to (K-10) to show all five HW in Appendix Kare now in Chapter 6 factor models instead of only the central model. 987. Section K 2, Page K-4 Please ensure that all of the references cited in the text are included Done in the list of references and that all of the references provide a complete description of the publication (e.g., volume and page numbers). 988. Table K-1. Page K-4 Please include all five of the C1 values that represent the five HW Done (Chapter 6) factor models in Table K-1. 989. Table K-1, Page K-4 The "Central" and "Range of Models" shown in this figure have not Done been discussed the first time this figure is referenced in the text. Please provide an explanation of these curves as well as an explanation that the curves and GMPE estimates are for Ztor = 0 in the figure caption of this figure and in Figures (K-2) through (K-4). 990. Figures K-t. K-2, K-3, Please make changes to the legend to reflect that the dashed lines Done and K-4 do not show the "range" of the models, but rather are the five individual models used to approximate the distribution of the modeled HW factors 991. Figure K-5, Page K-Please check the CB14 HW factor for the increasing Ry curve, which Figure fixed 10 for Rx = 0 should have a positive HW factor that decays with distance (i.e., it is only for Rx< 0 that CB14 predicts no HW effects). 992. Figures K-5 and K-6 Please change "rx" in the figure legend to "Rx" to be consistent with Done the main text. 993. Figure K-7 Please explain in the caption the meaning of the solid black curve in Done each plot and provide references to the three simulation models that are defined by their acronyms in this and similar figures in the appendix. Please also indicate that the SWUS HW tenn (called HW factor model in the text) that is plotted in this and all similar figures as the red line is the central model. APPENDIX 0 Comparison of Hazard: Original GMPEs versus Common Functional Forms 994. General Although the plots shown in this appendix show that the range of Plots added hazard is captured, it would be useful to show a comparison of the hazard curves from the GMPEs with the 5th, 50th. and 95th percentile hazard curves from the common-form models in order to also show that the body and not just the range of the hazard is also captured. Please provide such plots in addition to those that are already shown for the DCPP and PVNGS models. 995. Section 0. 1. page 0-The reference to a simplified" seismic source model is confusing. Chapter 14 was modified to indicate a simplified SSC model 1, 2M of This sentence refers to it as the DCPP SSC model used in Chapter is used for DCPP. This resolves the inconsistency. No section, 2° sentence 14, and the First Paragraph on Page 14-1 states that "the previously change to Appendix 0 text. published Seismic Source Characterization (SSC) models for the two sites were used", without reference to any simplification. Please review and revise the entire paragraph as needed to clarify. 996. Section 0.1, page 0-Without a comma after the words "closest sources, this sentence is Done 1, 2r.d of (almost) ambiguous as written. It could mean that the source model section, 2" sentence comprises the closest sources, inasmuch as those are the significant contributors. But it could easily be misread to mean that, among all sources that are significant contributors. the model singles out only the closest ones. If the former interpretation is intended, please clarify that by means of a comma. 997. Section 0.2. General Except for the addition of the hazard curve from GK 14, Section 0.2 Appendix 0 was modified to show additional periods and appears to provide the same information as provided in Section 8.4.3 fractiles (and Figures 8.4-17 and 8.4-18). Please clarify what is new in Section 0.2, compared to Section 8.4.3. 998. Section 0.2. Page 0-Please see comments given in other chapters and appendices Akkar's references fixed 1, 1st Paragraph of regarding suggested revisions to the bullet list of references to these Section, 3rd Line eight GMPEs. 999. Section 0.2. Page 0-Please provide the reference to sections of the report where the Done 2, 2r.d paragraph on common-form models are described. page ( t sentence after the bulleted list) 1000 Section 0.2. Page 0-Please indicate who calculated the common-fonn model hazard Done 2, 3rd Paragraph, 1st curves (i.e., the Tl Team, a hazard analyst, etc.) and the hazard Line code that was used. 1001. Section 0.2. Page 0-Please describe in more detail the modification that was made to the Clarification added 2, 3rd Paragraph, 5th ASK14 model. Line 1002 Section 0.2. page 0-Similar to the earlier comment, a comma after the words "hanging-Sentence has been rewritten 2, zn* paragraph of wall model" would help insure a correct interpretation of the section, line 6 sentence. 1003. Section 0.2, page 0-Please consider adding the qualifier that the mean hazard from the Done 2, 3'0 paragraph of section, 3'" sentence common-form models plots near the upper limit of the GMPE range at the relevant hazard levels (e.g., 10* and less) and that this does not seem lo be so clearly the case at higher hazard levels. 1004 Figure 0.2-1a, Page In this and all similar figures in this appendix, please use the same Done 0-3 acronyms for the models listed in the legend that are used elsewhere throughout the report and appendices (e.g., use "ASK14" instead of "ASK") 1005. Section 0.3. General Except for showing hazard curves from Model A and Model B See answer to question 997 together on the same plot, Section 0.3 appears to provide the same information as provided in Section 9.1.1.3 (and Figures 9.1-19 and 91-20). Please clarify what is new in Section 0.3. compared to Section 9.1.1.3. 1006 Section 0.3. Page 0-Please see comments given in other chapters and appendices References fixed (Akkar & Bindi); Consistent acronyms used 7, 2nd Paragraph regarding suggested revisions to the bullet list of references to these six GMPEs. 1007. Section 0.3, Page 0-Please avoid the use of the subjective term "significant" and instead Sentence has been rewritten 7, 3rd Paragraph, 9th provide a quantitative metric to describe the contribution to the Line hazard of the distant seismic sources 1008. Section 0.3. page 0-Please add a comma after the word "strong, to signal that the Done 8, last line subsequent "as" is being used as a conjunction to introduce a clause (not to express similarity). 1009 Figure 0.2-1a, Page It is difficult lo tell the difference between the two blue dashed Not done at this lime 0-9 curves in this plot. Please use a different color andlor symbol so that these two curves can be more easily distinguished in this and similar figures in this appendix. 1010. Section 0.4. Page 0-Please ensure that all of the references cited in the text are included Done 13 in the list of references and that all of the references provide a complete description of the publication (e.g., volume and page numbers). APPENDIX Q Host Kappa 1011. General comment A list of references is missing from the appendix. Please include a This Appendix is now renamed "M. complete list of references in a separate section of the appendix. References are now inserted 1012. General comment There are a lot of parameters. terms, and acronyms used throughout Done everywhere in Appendix Mas applicable the appendix without first being defined. As a reiteration of previous comments on various chapters and appendices in this report. please ensure that all of the parameters. terms. and acronyms used in this appendix are defined in a list prior to their use. Otherwise, they will need to be defined the first time they are used in each chapter and appendix. 1013. General comment Please check, in this appendix and throughout the report. to ensure Clarification on the meaning of Host Kappa has been that geographical terminology and acronyms are consistent with provided. II is not related to the host region from the SSC usage in the DCPP and PVNGS SSC projects. One example worth perspective. checking is whether "Sonoran Basin and Range" is the name for the PVNGS host region (please confirm that it is not "southern Basin and Range" in the PVNGS SSC, or if it is, make changes to ensure consistency). 1014. General comment Please make the notation consistent throughout the chapter (and Changed kappa(O) to Ko consistent with the rest of the report). For example, the decay exponent is sometimes spelled out in roman letters as "kappa", sometimes given by 1he Greek letter i-:, and k, and k1 seem to be used in1erchangeably (and k(O) is used in lieu of i-:o, even though the latter seems to be advocated by Ktenidou et al., 2014). In the process of clarifying, please also give consideration to the merits of following as strictly as possible the published taxonomy of Ktenidou et al. (2014). 1015. General comment Please define kappa and provide the foundational references that A new section ("Kappa Components and Terminology") was established the empirical basis for this concept added to provide a description of kappa, its componen1s and the adopted terminology. 1016. Page Q-1 , first The term "Host kappa" is jargon that only insiders will understand, Host kappa is defined in Chapter 5.5.3. Cross reference paragraph particularly since "host" is used in multiple, seemingly quite different added, and definition repeated senses in the report (e.g., in Chapter 14, "host" refers to the Sonora Basin and Range region in which PVNGS is situated). Please begin by explaining precisely what is meant by the term in the current chapter and how the host kappa estimates are then used in the GMC model. Please also cross-reference those places in the report where the resulting kappa estimates are used. 1017. Section Q. 1. Page 0-Please revise the Akkar et al. Bindi et al.. and Zhao references to Fixed in Appendix M (formerly Appendix Q). Completed on 1, 1st Paragraph of show the correct publication dates and acronyms (as used figure labels. Section elsewhere throughout the report and appendices) and to include the published errata for the first two references. Please also ensure that the correct acronyms for the GMPEs that are used throughout the report and appendices are used here and elsewhere throughout the appendix, including in figure legends and figure captions. 1018 Section 0. 1. page 0-Please provide the meaning of IRVT upon its first occurrence, and Reference included in response to comment #1020 1, 2M paragraph of provide a reference to the method (not just to the computer section, 1*1 sentence program). 1019 Section 0. 1. page 0-Please rewrite the sentence with parallel construction to improve Done 1, 3r<1 paragraph of clarity (e.g., "for spectra with higher host kappa than for those with section, last sentence lower host kappa," if that is the intended meaning). 1020. Section Q.2, Page Q-Please provide a reference for 1he IRVT approach that is used, (e.g., See answer to 1018 1, 1st Paragraph of if it is that published by Al Atik et al., 2013, please indicate that). Section, 1st Line 1021. Section Q.2. page Q-This comment refers to the phrase "while also limiting the a Sentence removed to avoid confusion and this point is 1, 1"' paragraph of attenuation effects" The kappa effect is itself most likely, at least in clarified in the added section "kappa Components and section, Line 4 part, a Q effect (which would be better described as an "anelastic Terminology". effect"). but just one that is so localized that it is more practical to treat it as a separate site-associated parameter. To avoid feeding confusion on this point, please state more precisely what is meant by this phrase. If the Tl Team chose close stations in order to isolate that part of the attenuation that persists in the limit of short propagation paths and is therefore suited to modeling as a site-associated attenua1ion factor exp(-pi"kappa"f), please indicate that 1022. Section Q.2, Page Q-Because of its common use in stochastic simula1ion, please also The Boore and Joyner (1997) Vs profile and corresponding 2, 2nd Paragraph on provide and plot the Vs profile for the WUS crustal model of Boore site amplification factors were not used in the derivation of page, 1st Sentence and Joyner ( 1997) in Figure Q-1 . Likewise, please plot the related the host kappa values. Therefore, Figures M-1 and M-2 only site-amplification factors for the WUS crustal model of Boore and show plots for the profile that is relevant for this study. Joyner (1997) in Figure (0-2). 1023. Section Q.2, Page Q-Please describe and reference the "OWL program" that was used to We added reference to Boore (2005). Also, added reference 2, 2nd Paragraph, 6th obtain the Vs-density relationships and summarize those to Boore's write up on the Vs-density relation Line relationships for completeness. 1024. Section Q.2. Page 0-Please explain what an angle of incidence of zero means and why it A discussion on the impact of using a different angle of 2, 2nd Paragraph, 5th was assumed to be zero and what impact this assumption has on the incidence on the results is added. Sentence final results. 1025. Section Q.2. page 0-Please consider referring to "the nine selected scenarios" to clarify Done 3, 3rd paragraph of that the reference is to the selections made in the earlier paragraph section (1" on page), for the reasons stated there. The current language given by the 1" sentence phrase "the nine scenarios considered," could be misunderstood as part of an evaluation process (i e , that some were considered and rejected, for example). 1026. Section Q.2. page 0-This sentence asserts that the kappa derived using the IRVT Refer to the added section "Kappa Components and 3, 3m paragraph of approach (k1) is not equal to kappa(O). This categorical statement Terminology" which elaborates on this point. section (1" on page), could imply that k1 is in principle not able to capture kappa(O). Is that line 8 &9 really the meaning intended? If so. please explain. and reconcile this assertion with the fact that Ktenidou et al (2014) classify the IRVT-derived method as a k(O) estimator in their Table 1. Otherwise, please reword these lines. 1027. Section Q.2, page Q-As noted in an earlier comment, the reference here to "anelastic This is now better described in the added section "Kappa 3, 3'0 of attenuation" implies that the kappa decay factor is not a Components and Terminology" section (1" on page), consequence of anelastic attenuation. whereas the scientific 2"c to last sentence consensus is that it is (at least in part). Please reword this sentence to express the intended meaning more precisely. 1028 Section 0.2. page 0-Please explain the distinction being made here between k(O) and This is explained in the added section "Kappa Components 3, 3'° paragraph ( 1 ** k,;, ** and justify the assumption that there is no source contribution to and Terminology" with appropriate references added. on page), last line kappa. 1029. Section Q.2. page 0-Please explain what is meant by "best picks. On what criteria was "best picks" is replaced with "best visual picks" 3, 4'"' paragraph of the selection made? section (2"" on page), Line 5 1030 Section 0.2. Page 0-Because this appendix is intended to present the details of the host Plots are added for all 9 scenarios for all seven GMPEs 3, 2nd Paragraph on kappa calculations. please provide plots for all nine scenarios for all page, 5th Sentence seven GMPEs for completeness. 1031. Section Q.2, Page Q-For completeness, please provide the standard deviations of the Evaluating the uncertainty of the host kappa values to the 3, 2nd Paragraph, 6th host kappa values shown in Table Q-1 that account for uncertainty in selection of f1 and f2 and to the use of different host Vs Sentence the f1 and f2 picks, the nine different scenarios, and the two different profiles is outside the scope of this Chapter. The goal here is crustal models. to provide best estimates for the host kappa values. The standard deviations of the host kappa values for the nine scenarios used are added to Table M1. 1032. Section Q.2. page 0-The phrase "best estimate" seems to be used in two different senses This sentence is rephrased. 3, 4"' paragraph of in its two occurrences in this sentence. Please clarify. Also note that section (2"" on page), there appears to be a missing word or words after "GMPE." last sentence Comment Response Table Comment Location in PPRP Comment Summary of Revisions to Report Number Text CHAPTER 1 Introduction Lines 51-55 Suggest this sentence be broken into 2 sentences for clarity done Line 62 Comma after "site-specific rock condition" done Line 91 Suggest putting Q in parentheses done Line 149 Fix margins Done, use justified margins CHAPTER 2 Project Organization Line 13 Suggest comma after "(U.S. NRC, 1997)" done Line 35 Set should be plural done Line 99 Product should be plural done Line 146 Estimated should be estimates done Line 155 Suggest comma after Arizona done Line 238 Suggest comma after comments Done Line 240 Suggest insertion of "the" after reviewing Done Line 252 "shows the dates of the main .. " change "of' to "that" done CHAPTER 3 Work Plan Line 9 Suggest insertion of "the" belween "as" and "kick-off' done Line 120 Station should be plural done Line 125 Suggest comma after "conducted" done Line 159 Questions should be plural Done Line 187 Include should be included Done Line 224 Suggest insertion of "the" between "In terms of' and "sigma models" Done Line 238 Insert "to after "prior done Line 291 Insert "to" after "pertaining" done CHAPTER 4 Seismotectonic Setting Line 60 Ranges should be singular done Line 112 and 116 Capi1alize Southern consistently, or use lower case consistently for Done. Capitalized notation is used Southern Basin and Range. Suggest caps. as we have formalized the term SBR Chapter 5 Ground motion Databases Line 37 Suggesl comma after residuals done Line 140 Suggest insertion of the" between "For" and "objective" done Lines 140, 141 Suggest period after "al" in Lin et al. (here and elsewhere) done Line 186 Suggest changing containing to contains. done Line 313 Suggest comma after (Pasyanos et al., 1996) done Line 385 Ruptures should be plural. done Line 422 "using for?? should this be used for? done Line 451 "The subsets of the subset of... is confusing. Is this correct? Please Done. consider rewording. Line 484, 485 Was selected is repeated as selected was This is a confusing done sentence -consider rephrasing. Line 498 "study" should be studies done Line 501 "and by the distant" should be "and from the distant" done Line 579-580 There is no verb in this sentence done Line 586 Figures should be singular done Line 623 The citation to Table 5.4.4-1 has an extra period "4.-1" done Line 654 Function from? Do you mean functional form? done Line 695 Insert "and" between "another" and "should" done Line 699 A comma is needed after "selected" done Line 703 Change rejection to rejecting. or place "of' after rejection done Line 703 "ad" should be "and" done Line 752 Suggest a comma after is used" done Line 754 Suggest set be pluralized done Line 777 Suggest a comma after data" done Line 787 Change "as" to "at" done Chapter 6 GMC Models For the Median Line 16 Delete up" fixed Line 42 Delete the extra ) after T akedatsu, 2015 fixed Line 57 Insert "to" between "leads" and a model" fixed Line 58 Add "because" after **and furthermore." fixed Line 67 Magnitude should be plural fixed Line 71 Add a comma after "50 km) fixed Line 143 Replace "in" with "on" -Based on ... fixed Line 155 Insert "a between "explained as" and "geometric" fixed Line 238 This would read better as " ... Model to account for the HW ... fixed Line 274 Was calculated or were calculated? Line 362 Place a comma after GMPE. Also. magnitudes should be plural. fixed Line 439 Place a comma after (Model B) fixed Line 466 Insert "and" after M>7.5, fixed Line 496 Place a comma after "used" fixed Line 542 HW models" -models should be singular. fixed Line 548 Change applies to applied fixed Line 569 Set off wi with commas fixed Line 594 In is given" should read "It is given" fixed Line 615 "the difference is scaling" -is should be "in" fixed Line 801 Reflects should be singular fixed Lines 802/803 Move "fully" to before "represents fixed Line 830 Example should be plural fixed Line 882 Figures should be lower case fixed Line 892 "These two model" -model should be plural fixed Line 902 Insert "to the between similar and Spudich fixed Line 936 Insert a comma after (20t4) fixed Line 954 Insert "a between "for" and "strike-slip" fixed Line 1019 Insert "a between ruptures of' and splay fault" fixed Line 1029 Insert an "a" between Approximate a" and "Single Fault". Same with fixed next two lines. Chapter 7 GMC Models for the Sigma Line 12 The closing parentheses should not be subcase fixed Line 100 Insert a comma after "used" fixed Line 101 Insert a comma after "data" fixed Line 107 Insert a comma after "used" fixed Line 108 Insert a comma after "residuals" fixed Line 194 Delete the extra "for" near the end of this line. fixed Line 290 Insert "of' between "distances" and "200-300". Also, Section should fixed be lower case. Line 291 Indicated should be indicates fixed Line 301 Insert "a" between "of' and "few" fixed Line 318 "explanation or this trend change "or" to "for" fixed Line 382 with respect of distance" should be "with respect to distance" fixed Line 499 Provide should be plural Fixed: the figure is now singular, so the verb is written as "provides" Line 518 Insert a comma between branches" and "is developed" fixed Chapter 8 Median GMC Models: DCPP Line 36 Suggest a comma after figures" fixed Line 42 Consider changing random to randomly fixed Line 55 Fault should be plural fixed Line 60 "to the five" should be "for the five" fixed Line 86 "DCPP has made .. . should be "DCPP was made" fixed Line 167 model this penalizes" should read "model that penalizes" Sentence restructured Line 293 Insert "and" before "as noted" Sentence restructured Line 377 Insert a comma after "removed" fixed Lines 395-396 Place a comma after magnitudes and delete the and" before fixed distances Chapter9 Median GMC Models: PVNPP Line 11 Tl Team should read Tl Team's. Also. weighed should be weighted. fixed Line 25 Capture should be plural It is plural (associated to "weights") Line 40 Insert a comma after "considered". Also. (NGAW2-pv.MEov fixed needs an end-parenthesis Line 41 Remove end-parenthesis after Section 5.3.2 fixed Line 82 Insert a comma after "respectively" fixed Line 86 Under laying?? Underlying? fixed Line 119 There is an extra period after "is used" fixed Line 185 Magnitude should be plural fixed Line 182 Insert comma after "Figure 9. 1-2 fixed Line 219 This sentence would read better if "and that" was replaced by fixed "whereas'" Line 226 "right and side"?? You mean right hand side, correct? Line 254 "is referred to as "influence diagram" -insert "an after "as" fixed Line 278 Insert "to" after "respect" fixed Line 356 Remove the comma after "Section 5. 1.5.2" -it is not needed. Also, Inserted "rupture" after "each" "(M6.5 for each ... " Each what? Lines 412-416 Break this into 2 sentences. Start the 2"" sentence at 'Therefore, ... ** fixed Line 424 Sentence ends with a comma. fixed Chapter 10 Tau Model Logic Trees Line 4 Sectrion should be Section. Line 7 Insert "a" between "develop" and "single" fixed Line 34 Insert "that" after "2014 )" ok Chapter 11 Phi Model Logic Tree: DCPP Line 23 Place a comma after Taiwan. fixed Line 53 Place a comma after "Appendix R fixed Line 59 Place a comma after "respectively" fixed Line 79 Delete "a" between "as" and "heavy-tailed" fixed Line 127 Insert a space after phi Cannot find instance Line 132 Delete "the" between "because and "most" Chapter 12 Phi Model Logic Tree: PVNPP Line 10 Insert comma after PVNGS fixed Line 12 There should be the. Plus insert "are" after "the" "there" changed to these" Line 13 Need a) at the end of the sentence. fixed Line 28 Delete the extra space before the period. fixed Line 29 Insert "which are" after "events" fixed Line 30 Toe should be to. fixed Line 46 Number should be plural fixed Line 50 Time should be plural fixed Line 52 Insert "the" before Tl Team fixed Line 72 Insert a comma after "respectively" fixed Line 102 "dataset contains should read "datasets contain". Also, insert a fixed comma after "records" Line 123 Magnitudes should be singular fixed Line 132 Insert a comma after "respectively" fixed Line 137 Insert a comma after "respectively" fixed Chapter 13 Total Sigma Model Line 32 Approached should be approaches fixed Line 39 Represent should be plural It is singular and now reads as "represents" Line 42 Insert a space between "the" and "greater fixed Line 52 Change the period to a comma after Appendix P fixed Line 54 scaled" is repeated -delete one. fixed Line 74 One to one -correct the zero to a lower case o fixed Line 76 Point should be plural fixed Line 82 "uses" should be "used". Also. "numerical" should be "numerically" fixed Line 109 "Greater Arizona source" -source should be plural. fixed Line 125 Insert "as to after "designated" fixed Line 132 Delete "for" between "of the" and "single" fixed Line 135 indicated" should be "indicate". Also, insert "with" between that" Sentence slightly modified to fix issue and "the Line 176 Insert "affects" after "path" fixed Line 182 The title should read "Implementation of the Mixture Model fixed Chapter 14 Hazard Sensitivity Line 15 Insert comma after "plant sites" fixed Line 164 Insert comma after "several nodes" fixed Line 351 "show should be plural fixed Line 403 Change "that" to than fixed Line 461 Insert a comma after "approach" fixed Line 473 Delete "in" (presented in with the next case) fixed Chapter 15 Application Guidelines and Limitations Line 34 "then" should be "the" fixed Line 45 Insert "a" between "at" and distance" fixed Line 56 Available" is misspelled. constraint" should be constrain". fixed Line 57 "comprising is misspelled fixed Comment Response Table Comment Location PPRP Comment Summary of Revisions to Number in Text Report Tier 2 Comments (by chapter) General 1041. NIA Please carefully review the references for completeness and to ensure that all cited references are Mostly done in Rev. 1. Completed in Rev.2 listed. For example, some of the same references in different chapters are listed slightly differently (i.e., one might be missing a volume number or page numbers while another might not). 1042. NIA The report is written primarily in third person. which implies that the writers of the report. chapter, An author list is now included in the TOC andfor section performed the work or made the decisions and assumptions that are being described. (second page). However, there are no specific authors listed on the report. which is only identified by the publisher. GeoPentech, and a list of participants in the project. Please make ii clear who the writers of the report A comprehensive check was made to are either on the Title Page (ideally) or in the introduction so that there is clear ownership of the work ensure that the personnel performing the that is being described in the third person. When the description refers to someone else's work, evaluations or assessments are clearly decision. or assumptions, please make it clear that this is the case. There are also still sporadic uses defined. of the pronouns "we" and "us" throughout the report, which is even more ambiguous. Please consider replacing these pronouns with the person or group that the pronoun refers to (e.g., the Tl Team or a specific Resource Expert) or change the sentence to third person to refer to the identified writers of the report. CHAPTER 0.-Table of Contents 1043. NIA The Section No. 5 21. t appears twice. The second one should be 5.2.2. t. Fixed 1044. NIA In the title of Section No. 5.5 3, Vs should be Fixed 1045. NIA The Section No. 6 4 5 3 appears twice. The first occurrence should be 6.4.5.2. Fixed CHAPTER 1-Introduction 1046. Lines The description of Vs'¥! as "shear-wave velocity" should be more accurately described as "travel-time-Done in both locations 57-58 averaged shear-wave velocity." This change also applies to the definition of Vs30 in the list of terms and acronvms. 1047. Line 63 Please define "kappa," since this is the first time that this term is used in the report. Please also add Done in both locations the definition of kappa to the list of terms and acronyms, which only contains the specific symbols used to characterize the different ways kappa can be estimated and no definition of the generic term kappa itself. 1048. Line 80 Please define "sigma, since this is the first time that this term is used in the report. Please also add Term sigma is now introduced in Section the definition of sigma to the list of terms and acronyms, which only contains the specific symbols used 1. 1. and defined in abbreviation list to characterize the different types of standard deviations and no definition of the generic term sigma itself. 1049. Line Please consider replacing the phrase "suites of models" with "representative suite of models" here and Done 109 elsewhere in the report to conform with terminology used in "Atkinson. G.M., Bommer, J.J.. and Abrahamson, N .A. (2014 ). Alternative approaches to modeling epistemic uncertainty in ground motions in probabilistic seismic-hazard analysis, Seismological Research Letters, Vol. 86, pp. 1141-1144." CHAPTER 2-Project Organization 1050. Line 52 The description of the workshops is incomplete and does not list all of the purposes of the workshops. Sentence modifies to add the qualifier Please qualify the sentence to indicate that this is only one of the purposes of the workshops or "among other purposes. the Workshops .. " .. exoand it to list all of the ourvoses. 1051. Line 53 Since this is the first time that peer review is mentioned in the report, please introduce the peer review PPRP is already introduced in Section panel and the acronym PPRP. Please also add the definition of PPRP to the list of terms and 2.1.2. and is already included in the list of acronyms. acronyms 1052. Line 75 The use of the phrase "Appendix A of Appendix A" is awkward. Please consider calling the appendix oJ Done in Chapter 2, cannot make the an appendix something different in order to avoid confusion (e.g .. "annex"). change in Appendix A because that is an executed document 1053. Line 81 Please correct the name of the power plant, i.e., "Saint Onofre" should be "San Onofre. Done 1054. Line Please correct the grammar in this passage, e.g., "preliminary estimate of the kappa sensitivity .. . Fixed 146 1055. Line The large magnitude earthquakes in California cited here appear to be the same events referred to "and Mexico" added 157 elsewhere in the report as large earthquakes in California and Mexico (appropriately, since the 2010 El Mavor-Cucaoah event is included). Please clarifv or correct for consistencv. 1056. Line Please provide a reference to the PEER report that is mentioned in this sentence. Section mildly rearranged to provide the 162 requested citation (Kishida et al.. 2014) 1057. Lines Please provide references for the PEER projects that are referred to in this paragraph. NGA-Subduction effort is now referred to 167-(reference provided by Yousef Bozorgnia) 171 1058. Line Please reference the report or appendix where the PE&A study can be found it is not a report, but the material was 187 presented in the Workshop #1 presentations 1059. Line Please consider replacing the word "sensibly" with one that better conveys what the writer intended to Changed to "significantly" 189 mean. 1060. Line Please explain what "anticipated" means in this context. Changed to "preceded" 253 CHAPTER 3-SWUS GMC Work Plan and Key Study Tasks 1061. Line 97 Please confirm that the distance range "30-100 km" is correct and should not be "less than tOO km." Changed lo "less than tOO km" 1062. Line In Table 3.4-1, "Ken Campbell Consulting" should be "Kenneth W Campbell Consulting." fixed 152 1063. Line Please clarify that "the second meeting" refers to the January 2014 Special Working Meeting. Clarification added 244 1064. Line In Table 3.7-1, "Ken Campbell Consulting" should be "Kenneth W Campbell Consulting." fixed 340 CHAPTER 4-Seismotectonic Setting 1065. Line Please explain the difference between "layered faults" and "individual faults." Definition of "layered fault added to text 160 1066. Lines These lines refer to two categories, namely "the California and Mexico faults (referred to as Regions 1 Entries in the table are now aligned with the 163-and 2&3 in this Report)," and "other faults (AZ,NM, NV, and Mexico)." Table 4.2-2 has rows for "CA text in the chapter 164 Faults" and "AZ, NV, & Mex Faults. Do the rows of the table correspond to the two categories of faults described in the text? If so, please align the te1TT1inology; if not, please clarify 1067. Lines The legends of Figures 4-8a and 4-8b are not well correlated with the text. For example, "NSHMP Clarifying text is provided in the chapter 172-faults" are noted in the legends but are defined neither there nor in the text And the text calls attention body. Also, a new set of figures showing the 179 to the dominance of distant fault sources for low frequency at 1 O"" AFE, but the figures do not identify contribution from individual faults has been the curves associated with "distant fault sources." Please reconcile the figure legends and the text. added: this supports the conclusions on the distant sources being the main contributors at low frequency 1068. Line In Figure 4-8a, please explain the meaning of "coarse" and "fine" areal sources. The meaning has been introduced in 289 Section 4.2 3 and is not repeated in the fiaure caption 1069. Line In Figure 4-Sb, please explain the meaning of "coarse" and fine" areal sources. The meaning has been introduced in 293 Section 4.2 3 and is not repeated in the figure caption 1070. Tables Please identify the pertinent site (i.e., DCPP or PVNGS) in the title of each of these tables. Done 4.1-4, 4 2-1. 4.2-2 1071. Figure The two line colors for the SAF are not well distinguished in the figure. Please consider making Done 4-t improvements to remedy this. 1072. Figure Please identify the site (DCPP) in the figure caption. Done 4-2 1073. Figure The arrow for the Cerro Prieto fault points to the Imperial fault (CPF is the next bold red line to the Done 4-6 SW). Please correct this. CHAPTER 5-Ground Motion Databases and Candidate Models 1074. Genera Two references for Kishida et al. 2014a and 2014b, appear in the reference list However. many of the Fixed Now the two separate references are I citations in this chapter refer only to Kishida et al. (2014) without distinguishing 2014a from 2014b. appointed to as 2014a and 2014b Please check and correct this omission. 1075. Genera The figure numbering scheme seems to be inconsistent in this chapter. For example, Figure 5.2.2-2 is Done. Now the figure and table numbers I called in Section 5.2.2.1, indicating the convention that only the chapter number and first two section reflect the two section level levels prefix the sequence number. But a Figure 5.2.3.4-1 is called in Section 5.2.3.4, so in that case the chapter number and all three section levels prefix the sequence number. There are some other anomalies as well. Please check carefullv and ensure that numberina is done consistentlv throuahout. 1076. Line 11 Use of the term "proponent models" is confusing, especially given that the report is written in third Word "proponent substituted with SWUS person with no identified authors. The term is usually reserved for describing a model or method GMC proposed by a Proponent Expert (PE). If this is not the meaning of the term in this context or in similar contexts elsewhere in the report. please consider using another term to describe the models or identify who the proponents are (e.g., "Tl Team proponent models") when the term is used. 1077. Line 27 The intended meaning of the sentence is ambiguous. If the intent is to say that the Wells earthquake Done was in the southern Basin and Range, please review for accuracy (e.g., was it in the northern or southern Basin and Range?). If the intent is that the Wells earthquake provides control for a normal faulting earthquake, if one should occur in the Southern Basin and Range, please clarify and correct, as needed. 1078. Line 31 Since this is the first time that the term "PSA" is used in the report, please define it Done 1079. Line 47 Please add that the bottom frames also show the number of recordings per site class. Verbiage added to address that the frame addressed the number of recordings per site conditions (VS30) 1080. Line 85 There is no evidence in Figure 5. t.2-1 of "Station Z14A, shown by the open star". Please clarify. Sentence restructured and reference to star removed (it was old text associated to a previous version of the figure) 1081. Line 87 Please complete the citation of Kishida" (ie., Kishida et al. 2014a or 2014b?). Done 1082. Line Please correct the figure number on this line, which should be Figure 5.1.5-1. Done 158 1083. Lines The spelling of the fault names differs between the text and Figure 5.1.5-2 ("ltozawa" in the figure Done 173-becomes "ldozawa" in the text, and "Yunodake" in the figure becomes "Yunotake" in the text). Please 174 edit for consistency. 1084. Lines The total moment given here and attributed to personal communication is inconsistent with the Paper of Tanaka et al is now quoted as a 175-moment magnitude of 6.7 given for this event on Line 164 (the sum of the moments on Line 175 imply reference of almost equal moment 176 M 6.56). Please resolve the inconsistency. In doing so, please consider whether it would be partitioning (Rev.2) appropriate to cite published moment estimates (e.g .. Tanaka et al., 2014, report a moment consistent with M 6.7 and approximately equally partitioned between the two faults) instead of those reported from oersonal communication. 1085. Line Please supply the missing Table 5.1.7-1. The correct citation is the table 5.1.2-2 202 1086. Line The symbols referring to the different types of kappa used in this sentence are slightly different from Done in this Section, a final check is 209 those listed in the terms and acronyms. Please use a consistent set of symbols for kappa throughout pending throughout the report the report and appendices. 1087. Line "co is undefined at this point in the text. Please correct this. Term introduced 216 1088. Line Please consider whether a more appropriate characterization than "upper bound" can be used here Done 223 (e.g., is that categorical statement even consistent with the one standard deviation ranges cited for the other methods?). 1089. Line Please include a reference to a publication describing the SCEC BBP (e.g., the paper by Maechling et Reference added 228 al. in the JanfFeb 2015 SRL may be appropriate). 1090. Line Please consider citing the published paper by Dreger et al. (2015) in the Jan/Feb 2015 SRL. Done 242 1091. Lines It is appropriate for the Tl Team to rely on the SCEC Validation Review Panel for the technical analysis Done 264-of the simulations, and to rely upon the judgment of that panel to determine which methods met the 266 acceptance criteria established in that review. However. the Tl Team itself needs to justify that meeting those acceptance criteria makes the methods suitable for the specific purposes for which the simulations are to be employed. Those purposes are staled on Lines 227-233. Please augment the summary statement on Lines 264-266 by explaining how meeting the SCEC review panel's acceptance criteria makes the simulation methods suitable for addressing the problems laid out on Lines 8-14. 1092. Lines This passage needs rewriting because: (1) the BSL model is not identified as GIL7 on Line 309, but Done 306-seems to be the same as what is called GIL7 in the legend of Figure 5.2.2-1 and then on Line 312; and 315 (2) the passage is repetitive (e.g., the verbiage about routine estimation of moment tensors on Line 309 is repeated on Line 314-315; the basis of the GIL7 model in broadband waveform modeling is staled repetitively on Line 308 and then on Line 314} 1093. Line "Frequency wave-number" is written differently on this I ine than it was on Lines 304 and 311 Frequency-wavenumber used in the section 322 ("frequency-wave number"). Please review the hyphenation convention and apply one consistently consistently (note also that both "wave number" and "wavenumber** are in common use, so the easier-to-read form "frequency-wavenumber" is also an option). 1094. Line "Area" is used to signify rupture area in Equation 52 3-1. but "A" is defined as rupture area on Line Done 361, 364. Please edit for consistency. 364 1095. Lines Please indicate whether this statement is an assumption or is based on an evaluation of data, models, Done 374-etc., by the Tl Team. 375 1096. Line Please correct the figure number. It is called out as Figure 5.3.2.1-1 on this line, but the figure itself is Done 383 labeled as Figure 5.2.3.1-1. Moreover, the numbering scheme used elsewhere in the report appears to call it Figure 5.2.3-1, since it occurs in a subsection of Section 5.2.3 (e.g., by analogy with the fact that Fiaures 5.2.2-1 and 5.2.2-2 occur in Section 5.2.2. n 1097. Line The figure number 5.2.3.2-1 is inconsistent wi1h the fact 1hat it is 1he second figure in the subsection. Done 392 Please check the figure numbering convention and make it consistent with the rest of the chapter and report. 1098. Line Please indicate that CB 14 also used the functional form of the hanging-wall term developed by Done 396 Donahue and Abrahamson (2014). 1099. Line Please consider replacing "we" (first person) with third-person to be consistent with the remainder of Done 411 the report. 1100. Lines The figure citations do not correspond to the figure numbering. Please check the figure numbering Done 427, against the figure citations and correct as needed. 431, and 433 1101. Line The table called Table 5.1.1-2 on this line appears to be the table labeled Table 5.1-2 (and called by Corrected 452, those numbers elsewhere in the report). Please correct here and in subsequent occurrences. 458 1102. Line Line 464 gives the distance criterion for NGA-W2_DC-MED as abs(Rx)<70km, whereas the lines 475 Done 464, and 481 give it as R<70 km, which is more restrictive. Please clarify how the various distance metrics 475, are used together to screen records for NGA-W2_DC-MED. 481 1103. Line Please quantify what "similar enough" means in regards to the value of (e.g., in terms of the Done 492 percent difference in site-amplification factors). 1104. Line Previously, Akkar et al. (2014c) was cited as the database reference. Please check whether the Clarification added -it is a subset of the 506 citation given on this line is correct in the present context. dataset used to derive the ASB 14 model, which in turn is a subset of the RESORCE database (Akkar et al 2014 c) 1105. Lines The criterion abs(Rx)<70 km leaves the total distance unconstrained. Please provide a complete Disagree, the abs(Rx)<70 corresponds to 508 statement of the distance selection criterion. Rx values less than 70 km on footfall and and Rx <70 on the hanging wall. It is not 517 unconstrained. No chanae in text. 1106. Line Please consider whether this might be a good place to introduce the symbol *** so that it will be Done 548 defined prior to its use on Line 553. 1107. Line Disaggregation" is used on this line, whereas "deaggregation" is used elsewhere in the report. Please Done 558 edit for consistency. 1108. Lines The selection criteria (distance. magnitude. number of recordings per event and site) do not seem to Sentence added 565-be given. Please check and correct if necessary. 572 1109. Line "NGA-W2 is "NGA-West2" elsewhere. Please edit for consistency. Done everywhere 566 1110. Line Please check whether "for use in" should be "is used in". As is, the sentence lacks a verb. Changed to "to be used in" 579 1111. Line Please add the missing parenthesis closure. Done 585 1112. Lines Please indicate whether the 3 events per station requirement was also applied. Yes, clarifying sentence added 592-593 1113. Line Section 5.41 does not contain the discussion of the Idriss 2014 model that is referenced here ("As Section 5.41 has now a sentence 601 noted in Section 5 4 1 "), nor does there appear to be any prior reference to the Idriss model in the describing how Idriss (2014) treats the chapter. Please make the necessary corrections. residuals 1114. Line Please replace "200-30 km" with 30-200 km." Done 610 1115. Lines CB 14 used mixed-effects regression to derive the anelastic attenuation term from data with RRuP > 80 Requested clarification added 614-km, but allowed the source terms to vary from those for RRuP < 80 km. Although this does not 615 necessarily impact the decision not to use CB14, the description of what CB14 did should be correctly stated in the text. 1116. Line Please indicate what range that "this magnitude-distance range" refers to. (M;:: 5.5. distance 200-400 km) added lo 619 the text 1117. Lines Line 619 has the statement that "the global dataset in this magnitude and distance range consists of Second sentence has been removed 619 264-415 recordings from 4 to 23 earthquakes." Line 625 states 'Within this magnitude and distance because it added confusion without and range, the global dataset contains four earthquakes and 280 records." Please clarify why these additional information 626 statements are not contradictory. 1118. Line The cited figures do not exist. Please add them. Figures existed but were misnumbered. 627 Figure number has been corrected 1119. Line Please correct the figure references (they should be to Figures 5.5.1-1 and 5.5.1-2). Done 669-670 1120. Line Please correct the figure reference (it should be to Figure 5.5.1-3). Done 673 1121. Line Please correct the table reference (the intended reference appears to be to Table 5.5.1-1). Done 683 1122. Line Please clarify why specific scenarios had to be specified. given that kappa is not being explicitly Kappa depends on the spectral shape 724 modeled as a source effect. which depends to the scenario. Clarifying text has been added 1123. Line Please explain why only footwall scenarios were used. Done 725 1124. Line Please consider rewording the reference to "Q attenuation." to avoid the implication that the kappa Done 727 effect is necessarily physically distinct from effects ordinarily parameterized in terms of 0. Isn't the point that the kappa parameter (or at least Ko) is intended to capture attenuation effects that are so localized that in a practical sense they are better parameterized as site terms than as path-dependent attenuation terms, and that therefore isolation of kaooa effects reouires short-distance scenarios? 1125. Line Please be more specific about which profile was used. Is it one of those in Figure 2.6 of Kamai et al. 760 m/s is correct. The profile referenced is 730 (one is listed as having Vs30 of 750 mis, none has exactly 760 mis)? the one in Appendix M 1126. Line Figure 5.5.3-1 appears to be labeled incorrectly. Please correct this. Done 735 1127. Line Rodriguez-Marek (2013) actually developed four single-station sigma models: one with neither M nor Text expanded to clarify the confusion 778 R dependence, one each with Mand R dependencies, respectively, and a fourth with both Mand R dependence. Please clarify which three have been chosen, and why. Note also that there is a perception of ambiguity introduced by mixing "dependent" and "independent" in listing the attributes of the selected models; i.e., is the "magnitude-independent" model alluded to also R independent (in which case it would be clearer to say "magnitude and distance independent). or is there a typo such that "magnitude-dependent" is what is actually intended? If one of the figures were not missing, this ambiauitv would be cleared uo. but it would be better to also do so in the text. 1128. Lines Please check whether the first of the three models alluded to should be "magnitude-dependent" (rather Text clarified to say that is magnitude-779 than magnitude-independent", which would appear to be inconsistent with the figures). Alternatively, if dependent and "magnitude-independent" is correct as written. please clarify whether it is paired with a distance 781 dependence or not. 1129. Lines Only the R-dependent and MR-dependent models are shown. and these are in Figures 5.6.2-3 and Done 780-5.6.2-4, respectively (not 5.6.2-4 and 5.6.2-5 as called in the text). The other model (called 782 "maanitude-independent" in the text} is not shown, nor is there anv Fiaure 5.6-5. Please correct this. 1130. Line Please cite a reference for the assertions about the small-magnitude limitations of GMPEs at short Atkinson 2015. Reference added in Rev.2 789 distance. 1131. Line Table 5.5.1-1 indicates that the Graizer (2014) GMPE was used for the DCPP GMC model. but the Table corrected. A reason to exclude the 1122 Graizer GMPE is not listed as being one of the models that was used in Chapter 6. Please either GK14 model has been added. In Chapter 6 correct the table or the text in Chapter 6. If this GMPE was used, please justify its use in view of the , we justify why using the GK1 model to fact that it is only published as a conference paper and has not been peer reviewed or vetted by the check the hazard. larger scientific community. 1132. Figure The caption cites Akkar et al. (2014a and 2014b). whereas the text (Line 121) cites Akkar et al. Clarification added 5.1.3-1 (2014c), apparently in the same context. Please check whether this difference is intentional and make a correction if appropriate. 1133. Figures These figures are mislabeled (as 5.2.3.3-1 and 5.2.3.3-2, respectively). Please correct. Fixed 5.2.3.4-1 and 52 34-2 1134. Figures Please correct these figures. In each of these figures, the second row repeats the first with a scale Fixed 5.3.2-1 change, and the remaining plots (recordings per site, recordings per event, etc.) are absent. and 5.3.2-2 1135. Line In Figure 5.4.1-2, please explain why there is a triangular symbol plotted at slightly over 100 km or, if Fixed in Rev.2 1258 this is an error, please remove the symbol. 1136. Line In Figure 5.4.1-3, please explain why there is a triangular symbol plotted at slightly over 100 km or, if Fixed in Rev.2 1263 this is an error, please remove the symbol. 1137. Line In Figure 5.5.1-1, please define the meaning of the solid black symbols and the color and black trend Done 1322 lines 1138. Line In Figure 5.5.1-2, please define the meaning of the solid black symbols and the color and black trend Done 1326 lines 1139. Figure Please correct the figure number. It is called Figure 5.5.3-1, but labeled 5 5 3-2. Fixed 5.5.3-1 1140. Figure Please improve the figure caption by including some basic contextual information Done 5.6.2-2 1141. Figure Please add the dataset identifiers given in Lines 805-808 of the text (Blea. Blea2. and ABR) to the Names added to the captions 5.6.4-1 figure caption. or else delete them from the text, as the inconsistency is confusing. CHAPTER 6-GMC Models for the Median 1142. Lines Table 5.5.1-1 indicates that the Graizer (2014) GMPE was used for the DCPP GMC model, resulting in Table 5.5.1-1 was corrected and some 23-24 the use of 9 models. The text indicates that 8 models, excluding the Graizer GMPE, were used. Please discussion added to Section 6.2.1 correct either the table or the text. 1143. Line Please hyphenate "large-distance attenuation" to resolve the otherwise ambiguous meaning. Done 105 1144. Lines Not all of the simulations show that hanging-wall effects persist down to magnitudes of 5.5 and 6.0 for Most of the simulations showed HW effects 209-all fault geometries. This suggests that there is some uncertainty in whether such effects exist. Please and the hazard sensitivities (Figure 0.2-3a) 210 discuss this apparent uncertainty and justify the decision to extend hanging-wall effects to smaller displayed that the effect is small, so we magnitudes, explaining whether this uncertainty is accounted for elsewhere. always included the HW adjustments. Discussion added. 1145. Lines Please explain why, if hanging-wall effects are geometric, the cosine term is more appropriate than the Discussion added 256-arithmetic angle to model these effects 257 1146. Line The statement that the hanging-wall models are "equally likely" and "normally distributed" is still Done 269 confusing on its face. However, the discussion that follows clarifies this apparent contradiction vis-a-vis the use of equal probability slices of the distribution. Perhaps, a statement like "as explained below" after introducing this apparent contradiction would provide less confusion for the reader. 1147. Line Figure 6.3.2-5 shows CB14 having a step-like change in its HW factor as Rjb approaches zero along Figure has been corrected and now shows 303 the strike direction. Please clarify how this is consistent with the claim that CB14 allows "a smoother the non-linear transition is smooth. but transition" around the rupture compared with some other models rapid. 1148. Lines In reviewing all of the figures comparing the HW adjustment model with the simulations, all except There were redundant figures. The figures 341-Figure 6.3.2-14 compare the simulations only with the central HW model In order to show that the five showing only the central model 343 HW models adequately capture the uncertainty in the simulations, please show all five HW models in comparisons were removed and the figures all of the figures and discuss any cases in which the five models to not appear to capture the showing the 5 equal probability models uncertainty. were retained. The text was modified accordingly. Also the figure numbering was not consistent with the section and the figure numbers were updated to 6 3.3-etc. It is pointed out that the HW model does not capture the simulations for points located off of the surface projection of the dipping fault (Rjb>O) and that the HWRjbTaper was designed to be consistent with the empirical data captured by the similar terms in the published GMPEs. Figures 6 3 2-7 (M5.5D45Ztor2.5-7-12) redundant with 11 Figure 6.3.2-8 (M6D45Ztor2.5-7-12) redundant with 12 Figure 6.3.2-9(M6.5D45Ztor0-7) redundant with 14 Figures 6.3.2-10(M6Ztor7D30-45-60) redundant with 13 Figure 6.3.2-11(M5.5D45Ztor2.5-7-12) 5 models Figure 6.3.2-12 (M6D45Ztor2.5-7-12) 5 models Figure 6.3.2-13 (M6Ztor7D30-45-60) 5 models Figure 6.3.2-14 (M6.5 D45Ztor0-7) 5 models 1149. Line The term "scaled-backbone approach" is never used by Atkinson et al. (2014). These authors do Sentence rephrased: "Atkinson et al. (2014) 363 mention the concept of selecting a single "central or backbone GMPE" and scaling it up and down, but introduced the concept of selecting a single do not specifically call this a scaled-backbone approach. Please consider replacing the term "scaled-"central or backbone GMPE" and scaling it backbone approach" wi1h a simple description of the approach instead. up and down. This concept is here referred to as the "scaled-backbone approach, which provides a method to develop a set of.. .. 1150. Line The term "generated models" is used in this sentence to refer to ground motion models derived from Done throughout report and Appendices 384 the visualization (Sammon's mapping) technique Terms such as "large suite of models" and (partially in Rev.1, completely in Rev 2) "representative models" were used earlier in the section to refer to similar models. The concept of using visualization techniques to produce a distribution of models that sample the full model space is difficult enough to understand without being confused further by the use of different terms to describe the same technique or products thereof. In order to avoid such confusion, please consider using a consistent and strict set of terminology to refer to these models. For example, the term "candidate models" has been generally used to describe the GMPEs that are used in conjunction with the visualization method, since this term is used elsewhere in the report to describe such models: the term "suite of models" might be used to refer to the entire set of models that are generated using the visualization technique (e.g., the 2000 common-form models); and the term "representative suite of models" might be used to refer to the final set of models that are used in the GMC logic tree (e.g., the 25 or so common-form models). This latter term is also consistent with the general term used by Atkinson et al. (2014) to describe the method of generating models that sample the model space, whether it be by simple methods (i.e., scaling up and down) or by more complex models, such as those sampled from the Sammon's map. 1151. Line It is possible that this is the first time that the term "Joyner-Boore distance" is used in the report. If so. Disagree. First occurrence of "Joyner-Boore 402 please note that this term refers to the distance metric RJa distance (RJa)" is in Section 6.3 1152. Lines Please delete "0,0" and replace "(fork= 7,8,9, 10)" with "(fork= 7,8,9)" since there is no k = 10 Fixed now (See general comment 1040) 412-coefficient in the model. 413 1153. Line Please replace "(fork= 7,8,9, 10)" with "(fork= 7,8.9)" since there is no k = 10 coefficient in the model. Fixed now (See general comment 1040) 429 1154. Line Please replace fork= 7,8,9, 10" with "fork= 7,8,9" since there is no k = 10 coefficient in the model. Fixed now (See general comment 1040) 433 1155. Line Please replace fork= 7,8,9 and 10 with "fork= 7,8 and 9" since there is no k = 10 coefficient in the Fixed now (See general comment 1040) 444 model. 1156. Line Please justify the selection of :::3 km to represent the uncertainly around the mean value of ZroR-Discussion added 449 1157. Lines In order for RJB to equal IRxl, the footwall site must be located at a source-to-site azimuth of -90 Done 463-degrees (i.e., perpendicular to the fault within the bounds of the ends of the rupture). Please indicate 464 that this is the case in order to justify the given distance equalities. 1158. Lines The term total residual" is usually reserved to mean the addition of the between-event and within-Fixed 472 event residuals in the aleatory variability model. Please consider calling this the total fitted residual" or and something like that to distinguish it from the true total residual. 493 1159. Lines The entire discussion of using candidate GMPEs and interpolated versions of the GMPEs and the A formula has been inserted to clarify the 502-generation and simplification of the coefficient covariance matrices is confusing to a non-statistician. concept 513 For example, what exactly are the sets of weights applied to and why can the covariance matrices be simplified in the manner discussed? Please consider expanding this discussion to better explain and justify exactly what was done. 1160. Lines Please justify how it is mathematically possible with the addition of the interpolated GMPE ground We demonstrate numerically that using the 506-motions to better capture the correlations? interpolation leads to a more stable 513 estimate of the covariance matrix. New paragraph inserted 116!. Line Please be precise about what types of standard deviations" are plotted in Figure 6 4 3-1. Plotted are the standard deviations for each 524 scenario in the vector that goes into the calculation the Sammon's maps (Vectors in Section 6.4.3). Clarifying text has been added to text and figure caption 1162. Lines This explanation needs to be set out more clearly. The sentence beginning on Line 536 states that "for Done 536-the DCPP application ... the central HW branch is applied to all common-form models." The rest of 548 the passage, although rather difficult to read, appears to indicate the following: (1) HW effects are omitted from the 2000 models used for the Sammon's map, (2) the central HW model is appended to those footwall models, solely for the purpose of the simplified hazard calculations used in the selection of representative common-form (footwall) models from the original 2000, and (3) randomly selected HW models (from the equal-probability set developed in Section 6.3.2) are appended to the selected representative set of footwall models, to give the final set of common-form models for application to DCPP. If this is a correct interpretation, then the last item seems to contradict the sentence from Line 536 (and if this is not a correct interpretation, some clarification is needed). Please rewrite for clarity and consistency. This paragraph would be less confusing if a strict use of terminology to identify all of the different types of models were used, as suggested in an earlier comment. Please be more specific in identifying what set of models are being described in each case. such as candidate models (i.e., the original published GMPES), common-form models (i.e .. the mean and interpreted GMPEs and presumably the 2000 or 7500 count versions as well), representative model (i.e., the common-form model that best matches the mean hazard in a given cell), and the suite of representative models (i.e., the ones that are eventually used in the logic tree). 1163. Line Please be explicit as to whether this paragraph is discussing the development of representative Fixed (refers to both sites) 552 models for both sites or just PVNGS. 1164. Line Please replace "magnitude/distance" with "magnitude-distance." Done 564 1165. Line Please review the appropriateness of subscript kin NG *. given that there is already a sum over k. Subscript removed (in Rev.2) 602 1166. Lines Please justify why uncertainty in Ztor is represented by adding 3 km to Ztor and not also subtracting 3 As noted in the previous comment# 1156, 614-km and why the value of 3 km was chosen to represent this uncertainty (see previous comment). this is not uncertainty in the mean Ztor for a 615 given magnitude. Two values are used so that the regression can determine the Ztor dependence. Because the scaling is linear with respect to Ztor, only two values are needed. No text added. 1167. Lines Please explain why a value for Ztor is needed in the RJa-based models when it was not used as a term The term "RJs-based models" refers to the 616-in these models, i.e .. how can "one Ztor value" be used if the models do not include Zlor at all? common-form models. not lo the candidate 618 GMPEs. The process is to generate ground motions from the candidate GMPEs and then refit them with a common-form model. To generate the GM from the candidate GMPES that use RRuP, a ZTOR value needs lo be defined When we fit the common-form models using RJB, there is no ZTOR term. Clarifying text added 1168. Line Please correct the spelling of the second occurrence of "PVNGS." Done 629 1169. Line Please check whether the intent of this sentence would be more clearly expressed if the final clause Done 632 were included inside the parentheses. 1170. Line It appears from Eq. 6.4-4 that it is the contributions to the Euclidean distance squared that are Done 633 weighted by the weights from Eq. 6.4-7 (not the contributions to the Euclidean distance itself. as stated). Please correct or clarify. 1171. Lines The phrase " ... then the point that corresponds to the position of the candidate GMPEs is selected" is Done 689-confusing. Please rewrite this phrase to make its meaning clearer. 690 1172. Line Please correct the typo. Le. "two week" should be "too weak." Fixed 704 1173. Line Please provide a brief statement. or reference. that describes a "Voronoi-diagram" or the section(s) of Reference added 706 an appendix where such a reference or definition can be found 1174. Lines Is it true that all of the models within a given Voronoi cell do not really represent the same level of The cells are small enough (range less that 719-probability on the ground-motion distribution? If this is true. the use of equal weights is an assumption. 0. t In units in the Sammon's map) that we 720 Please justify the use of equal weights to determine the weighted mean hazard in each cell. can use equal weight. To assign probabilities would require that we use the prior and in some cases we set weights not based on the prior. 1175. Line Please discuss the common form model that corresponds to the highest hazard curve in Figure 6.4.4-4 Discussion added 726 and explain why it falls so far above the cluster defined by the rest of the models in the same cell. 1176. Lines Although the distribution of HW models is nearly uniform for the DCPP representative models, the Discussion added 735-distribution of the hazard might not be, depending on what Voronoi cells received the higher HW 736 models (i.e., the high-hazard cells or the low-hazard cells). Please justify that the mean hazard is not biased by the random selection of HW models. 1177. Lines Please clarify what "results" are not sensitive to the discretization size of the Voronoi cells (i.e .. the Text revised to define "results". 762-weights or the hazard). It is possible that the hazard will be sensitive to the size of the cells (e.g .. what If only one cell was used, then, by our 763 if only one cell were used?). approach the selected model would correspond to the mean hazard for eaual weights (because we selected the model closest to the mean hazard). We note that, with very large cells (or just one big cell), equal weights would not be appropriate. We used equal weights because our cell size was small enough as described in Comment #1174. 1178. Lines Please show an example contour plot in Chapter 6 for those readers that do not care to read Appendix Reference Chapters 8 and 9 that include 804-H. example of those figures, in addition to 807 Appendix H 1179. Lines Please show an example distribution plot in Chapter 6 for those readers that do not care to read Sentence removed -the figures and 808-Appendix H. reference to appendix Hare included in the 809 sections that follow 1180. Line Two consecutive figures are called "6.4.5-8." Please check and renumber as needed. Fixed 879 1181. Lines The sentence starting with "Randomizing" appears to be unconnected to the rest of the paragraph. Sentence removed. 927-Please expand or rewrite this sentence to better convey is meaning. 928 1182. Line Please see the general comment regarding the documentation of the directivity model evaluation. See our answers above 929 1183. Lines If the standard deviation represents the variability in the hypocenter location, please explain what the Clarification added 937-median (or should it be the mean) represents (e.g .. the bias?). 939 1184. Lines Please justify why it is not necessary to include Ztor as a directivity parameter for those events that do Watson-Lamprey did not find the need to 951-not rupture to the surface (e.g., the directivity effects for M5.5-6.5 events that the GMPEs were include Ztor in her formulation of the 953 evaluated for). simplified model. Because we are not incorporating this model, we have not looked at more refined scaling of directivity effects with depth. No chanae in the text. 1185. Lines Please include sufficient details of the Tl Team's evaluations of the technical merits and limitations of Addressed in Tier 1 comments 962-the simplified directivity mode I in support of the decision to adopt this model for use in hazard 964 calculations (as also requested in one of the general comments). 1186. Lines Please explain the basis for the evaluation that the simplified directivity model is a reasonable Addressed in Norm's write up "Evaluation of 965-approach for capturing directivity effects (e.g., was the hazard using the CY14 directivity model and alternative directivity models for DCPP" 967 random hvoocenters comoared to that usino the simolified model?). dated march 9, 2015 1187. Lines Please identify which event NGA EQID 1017 represents and why it is justified to remove this event I* PGA. EOID 1017 I 981-because the event-terms of the GMPEs are not consistent. 01 982 001 " § 0.001 .... .. {. .. .,, *! 0 ... : :ff;#; c.. 0.0001 .. ... -0.00001 ;':' .-.j :) 0 0.000001 1 10 100 1000 Auptute Distance \kH1j The data from event 1017 are primarily at large distance. As a result the event term caoture the difference in distance scalino. This leads to an inconsistency for the event term correction of the within-event residuals of the BSSA model. It's not a problem for CY14 because of their fitting procedure. The BSSA within residuals are outliers, leading the path PhiSP-r to be larger than the ergodic standard deviation. The Ti Team judged that the trade off may be unreliable and removed for the path-effects evaluations 1188. Lines Please explain why there is a difference in plotted values between Figure 6.6.1-2 and Figure 7.4.1-6. The figure in Chapter 7 was the correct one. 990-Figure 6.6.1-2 is now corrected (Rev.2) 991 1189. Lines There seem to be two sets of LN values being given in this section. The -0.5 and +0.1 LN units listed Clarifications added 1008-in the previous paragraph appear to be biases in the log PSA values, whereas, the 0.32 and 0.35 LN 1009 units given in this paragraph appear to be standard deviations. Please make the distinction between these two sets of values clear in the text. Please also be more specific about what "numbers" (the biases or the standard deviations) the Tl Team considers to be "reasonable." 1190. Lines The use of the telTl'l "proponent model" or "proponent method" is confusing. since it can be interpreted Word "proponent" removed. In some 1015 as a model or method being proposed by a Proponent Expert (PE). If these models and methods are instances. it has been substituted with proposed by the Tl Team. please replace "proponent" with Tl Team" in this line and elsewhere in alternative" Section 6.7 where the term is used. 1191. Line Please delete the phrase "with similar rake, dip, width," which is incorrect based on the contradictory This refers to what constituted an individual 1036 and apparently correct description given on Line 1039. rupture. Clarifying text added 1192. Line Please note that this statement appears to contradict the phrase on Line 1036. which has been Done 1039 interpreted to be a typo in a previous comment. 1193. Lines The sentence "The ground motions from the 2011 Fukushima-Hamadori earthquake are evaluated Sentence deleted 1064-using the SRSS method in Section 9.1.5.2." appears to be disconnected from the sentences before 1065 and after it. It is also ambiguous what the "Therefore ... " at the beginning of the next sentence is referrino to. Please rewrite these sentences to better convev their intended meanino. 1194. Line Please explain which complex rupture "Complex Scenario 18" represents. Done 1076 1195. Line Please explain which splay rupture "Splay Scenario 1C" represents. Done 1096 1196. Line Please confirm whether "Model A should be included in the title to Table 6.4-2. Done 1300 1197. Line Please confirm that the CB14 GMPE is plotted correctly in the lower plot (M6.6. SS, PGA). PSA is correct. This reflects the difference 1343 in high-frequency spectral shape in CB 14 for Vs30 = 760. This is seen clearly in the response spectral shape comparisons. No change in text. 1198. Line Please confirm that the GMPEs are plotted correctly in this plot. For example, CB14 appears to have a This reflects the coarse sampling of the 1354 hinge or kink at M7, but its magnitude scaling term does not. magnitude. A finer sampling would show a smoother M-dependence. Caption auomented 1199. Line Please identify the models listed in the legend to Figure 6.2.3-1 by their correct acronyms (i.e., ASK14 Not done, original figure not available to us 1359 instead of ASK). at this time 1200. Line Please identify the models listed in the legend to Figure 6.3.1-2 by their correct acronyms (i.e., ASK 14 Done 1380 instead of ASK). 1201. Line Please identify the models listed in the legend to Figure 6.3.2-1 by their correct acronyms (i.e., ASK14 Done 1386 instead of ASK2014). Please also justify in the text why it is acceptable for the predictions from the proposed HW models to not encompass the predictions from all of the GMPEs. 1202. Line Please identify the models listed in the legend to Figure 6.3.2-2 by their correct acronyms (i.e., ASK14 Done 1391 instead of ASK2014 ). Please also justify in the text why it is acceptable for the predictions from the proposed HW models to not encompass the predictions from all of the GMPEs. 1203. Line Please identify the models listed in the legend to Figure 6.3.2-3 by their correct acronyms (i.e., ASK14 Done 1396 instead of ASK2014 ). Please also justify in the text why it is acceptable for the predictions from the proposed HW models to not encompass the predictions from all of the GMPEs. 1204. Line Please identify the models listed in the legend to Figure 6.3.2-4 by their correct acronyms (i.e., ASK 14 Done 1401 instead of ASK2014). Please also justify in the text why it is acceptable for the predictions from the proposed HW models to not encompass the predictions from all of the GMPEs 1205. Line Please identify the models listed in the legend to Figure 6.3 2-5 by their correct acronyms (i.e .. ASK 14 Done 1406 instead of ASK2014). 1206. Line Please identify the models listed in the legend to Figure 6.3 2-6 by their correct acronyms (i.e .. ASK 14 Done 1409 instead of ASK2014). 1207. Line In Figure 6.3.2-11, please justify in the text why it is acceptable for the predictions from the HW models Pointed out that for sites over the surface 1432 to not encompass all of the predictions from the simulations. projection of the fault plane the models to encompass the majority of predictions from simulations, but for sites located off the surface projection (Rjb>O) the simulations produce values larger than the model. The HWRjbTaper is based on the empirical constraints captured in the published GMPEs in which the HW effect 1208. Line In Figure 6.3.2-12, please justify in the text why it is acceptable for the predictions from the HW models See 1207 1438 to not encompass all of the predictions from the simulations. 1209. Line In Figure 6.3.2-13, please justify in the text why it is acceptable for the predictions from the HW models See 1207 1444 to not encompass all of the predictions from the simulations. 1210. Line In Figure 6.3.2-14, please justify in the text why it is acceptable for the predictions from the HW models See 1207 1448 to not encompass all of the predictions from the simulations. 121 t. Lines The plot for the Idriss model is labeled "114," inconsistent with "ld14" elsewhere in the chapter. Please done 1472 modify for consistency. (Figure 6.4.1-4a). 1475 (Figure 6.4.1-4b). 1478 (Figure 6.4.1-Sa), and Line 1481 (Figure 6.S.1-Sb) 1212. Line In Figure 6.4.3-3, please explain the meaning of "NGAW2PV-MED MODEL A" in the upper-left corner of Label removed from plot 1S29 the plot. 1213. Line In Figure 6.4.4-1, please explain the meaning of "NGAW2oc-MEo" in the upper-left corner of the plot. Label removed from plot 1SS2 Please also explain what the different colors for the solid circles representing the GMPEs and their epistemic uncertainty refer to and what the orey circles represenl. 1214. Line In Figure 6.4.4-2, please provide a legend for the color contours and explain the meaning of the grey Done 1557 ellipses and circles. 1215. Line In Figure 6.4.4-4, please define the axes labels and explain the meaning of "T001 DCCP4 MODELA" Done 1567 in the upper-right corner of the bottom plot. 1216. Line The caption states that the GMPEs are in black, but the legend indicates a different color. Moreover, Done 1586 the color assignments differ from those in Figure 6.4.5-2a. Please modify for consistency between (Figure caption and legend, and between the a and b parts of the figure. 64 5-2bl 1217. Line In Figure 6.4.5-7, please justify why it is acceptable for the predictions from the proposed model to not Sentence added to expand on the 1623 encompass all of the predictions from the candidate GMPEs. The inference is that there is less than discussion 5% confidence in those GMPE predictions that fall outside of the limits of the model. 1218. Line In Figure 6.4.5-8, please justify why it is acceptable for the predictions from the proposed model to not Sentence added to expand on the 1630 encompass all of the predictions from the candidate GMPEs. The inference is that there is less than discussion 5% confidence in those GMPE predictions that fall outside of the limits of the model. 1219. Line In Figure 6.5.1-3, please explain what directivity model is used to make the plot and where the Done 1666 epicenter and/or hypocenter is located on the fault. 1220. Figure Please label the vertical axis and explain the meaning of the term "ground motion factors" in the Done 6.7.2-2 caption. 1221. Figure Please identify the GMPEs associated with the respective colors. and the meanings of the different Done 6.7.2-3 styles of grey lines, and make improvements to the legibility of the figure (note also that the figure did not appear in its entirety in the supplied PDF version). Also please explain the meaning of the term "Qround motion factors" in the caption. 1222. Figure Please label the vertical axis and explain the meaning of the term "ground motion factors" in the Done 6.7.2-5 caption. 1223. Figure Please identify the GMPEs associated with the respective colors. and explain the meaning of the term Done 6.7.2-6 "ground motion factors" in the caption. CHAPTER 7-GMC Models for the Sigma: Overview and Methodology 1224. Lines Please note that by the sigma terminology of Al Atik et al. (2010) "single-station within-event" standard Notation changed throughout the report and 8-9 deviation should be "single-site within-event standard deviation. Please consider consistently using appendices the terminology of Al Atik et al. (2010). 1225. Line 74 Please consider assigning the Zhao et al. (2006) model the acronym used in Chapter 6 (i.e .. ZH06) as Done shorthand in the remainder of the chapter. 1226. Line 84 Please add the missing words in this sentence (which currently reads "and chose through the"). "to smooth" added before "through" 1227. Line 87 Please consider revising "smooth" to "constant." "Smooth" changed with period-independent" 1228. Line Please consider using a different word than "proponent" on this line and elsewhere in the chapter to Proponent changed to "candidate" 155 explain the different Tau and Phi models so as not to confuse them with models that have been proposed by Proponent Experts (PEs). 1229. Line Please rewrite the sentence beginning with "The values .. " to better convey its meaning. The Sentence is modified now (see answer to 177 second half of this sentence appears to be incomplete. comment 197 1230. Line Please correct the figure citation. which should be to Figures 7.2.3-2 and 7.2.3-3 (not "7.2.3-3 and Fixed 183 7.2.3-3"). 123t. Line Please replace the term "proponent" with the term "candidate" to be consistent with terminology used Done, see comment t 55 191 elsewhere in the report. 1232. Line Please replace the term "proponent" with the term "candidate" to be consistent with terminology used Done, see comment t 55 195 elsewhere in the report. 1233. Line Please rewrite the final sentence of the paragraph to clarify its meaning (i.e., a "value" cannot be Sentence rewritten as "The standard 197 similar to a "model," so it is not clear what point the sentence is trying to convey). deviation of r2 was fitted to a constant, period-independent function. The period-independent constant estimate is similar to the central model" 1234. Line Please change crss to cr,. Done 202 1235. Line Please replace the term proponent" with the term "candidate" to be consistent with terminology used Done, see comment 155 207 elsewhere in the report. 1236. Line Please describe the type of distribution used in the simulation. Normal distribution. Sentence added 232 1237. Line Please indicate whether "Dawood et al. (2015 )" should be replaced with "Dawood et al .. 2014 -in The correct citation is (2014) and is already 269 press" and, if not. please provide the reference to the former. included in the reference list. The notation "in press" has been removed from the text 1238. Lines This paragraph appears to be contradictory and the Tl Team decision to use a magnitude-independent Sentence introduced to state that, upon 271-Phi_ss is not well supported by the first sentence in the paragraph and the results in Figures 7.3.2-1. visual examination of the M-binned PhiSS . 275 Please expand this paragraph to better discuss and justify the decision to use a magnitude-the Tl T earn judged that is no significant M-independent model for Phi_ss. dependence seen consistently at most of the available periods 1239. Line Please correct the inconsistency between the phrase "shown .. for four spectral periods" and the list Done 273 "(PGA, 0.1,0.5, 1.0,3.0 sec)," which (like the figure itself) includes five periods (PGA in addition to the four aiven spectral periods). 1240. Line Please explain why the Phi_ss values of the GLOBAL datasets for each GMPE are only shown for five The reasons are described in Chapter 5. 276 periods in the figures and indicate, if only five values were used in the analysis. why Phi_ss values for The Lin et al. dataset in our possession had the other periods are not used. only those five periods. 1241. Line Please describe how CV(4>ss) = 0. 12 was derived. It is explained in Section 7 .3.1. A cross 320 reference has been added 1242. Line Please avoid the use of the first person us." Done 388 1243. Line The statement that the between-event residuals were provided by the NGA-West2 developers is Sentence modified to clarify the difference 396 contradictory lo the statement on Lines 404-405 that the Tl Team calculated the residuals. Please in the approach between PhiSS (NGA rewrite the text to remove this contradiction. residuals) and PhiSP-R(new residuals from data recorded at Arizona stations not included in NGA-West2) 1244. Line Please avoid the use of the first person "we." Since the use of first person has appeared several times Done 404 in this chapter, please search the entire chapter for other uses of first person and convert them to third oerson. 1245. Line This statement is confusing and again suggests that the between-event residuals provided by the See answer to 1243 407 developers are perhaps being used. Please consider rewriting or expanding this entire section to make the orocess of develooina the LD sinale-path standard deviations less confusina. 1246. Line Please change oW;i to oW;1k Done 415 1247. Line In the Figure 7.2.4-4 caption, please consider replacing the word "proponent" with candidate" to be Done 730 consistent with how these models are referred to elsewhere in the report. 1248. Line In the Figure 7 2 5-1 caption, please consider replacing the word "proponent" with candidate" to be Done 744 consistent with how these models are referred to elsewhere in the report. 1249. Line Please explain what is the first issue. Verbiage modified to "An issue associated 469 to" There is no first issue in the text. 1250. Line In Figure 7.3.2-3, please consider showing the periods with average "no-Lin et al. Data" to show that Done 784 these values are also bracketed by the low and high proposed values. 1251. Line In the Figure 7.3.3-1a caption, please describe what the black solid and dashed lines represent. Also. Done 812 in this and many other figures there are error bars on the symbols, but no mention of them in the legend or the caption. Please define the meaning of the error bars in this and other figures in this chapter and for similar fioures elsewhere in the report where thev mioht appear 1252. Line In the Figure 7.3.3-1b caption, please describe what the black solid and dashed lines represent. Done 821 1253. Line In Figure 7.4.2-1, this figure clearly demonstrates that the assumption that the standard deviation is An expanded discussion on lack of data to 898 constant at low and high periods is totally unsupported by the data (note that the values at 0.2 sec derive Phi SP-R above 2 seconds has were not used because of reliability issues). Please further justify in the text why it is appropriate to been added extrapolate the first and last values as constant values to lower and higher periods and why the uncertainty should not become larger at low and high periods given this added uncertainty. Discussion expanded. CHAPTER 8-Median GMC Models: DCPP Sources 1254. Section There does not appear to be a reference to Figure 8.2-3 Please check and add a reference lo this Fixed, now is quoted in Section 8.2.2 8.2.2, figure if one is missing. general com me nt 1255. Lines Please explain the bases for the values used to define the three branches and their weights included Sentence expanded 60-61 in the second node of Figure 8.2-3. 1256. Line This is not necessarily true for the Akkar et al (2014a,b) and Bindi et al. (2014a,b) GMPEs that were Bindi 2014 is not a candidate GMPE for 100 developed using subsets of the RESORCE database and with at least some interaction between them DCPP, therefore the issue is not pertinent under the auspices of the SIGMA project. Please clarify this statement. to Chapter 8. Some clarifying text has been added. 1257. Line Please add the missing word "models" after "common-form". Fixed ("models" added) 125 1258. Line Please improve clarity by adding a sentence break after the word "model." Fixed 167 1259. Lines Please reference where in the report the evaluation of Id 14 was done to determine that it was Reference to Section 6.2.1 is already cited. 293-unreliable for RRuP < 3 km at large magnitudes. Text revised to make this point clearer. 295 1260. Line Please indicate what models are being compared in Figure 8.4-8. The discussion references both the Description added 302 common-form models and the candidate GMPEs and it is not clear which is being referred to when not exolicitlv stated in the text. 1261. Line Contrary to this sentence. curves corresponding to the epistemic uncertainty are not included in Figure Same issue applied lo Figure 8.4-8 which 310 8.4-9. Please add the curves or modify this sentence to remove reference to epistemic uncertainty. has been changed so lo show the candidate GMPEs with the epistemic uncertainty. Sentence is now consistent with figure 8.4-8. Figure 8.4-9 has been fixed and now the epistemic uncertainty curves are shown for M 6.5 and 7.5 in addition to M5.5 1262. Line Please provide evaluations or provide a cross reference in support of the conclusion that "differences Change "will to "may to make this less 355 in the magnitude and distance scaling wil I also impact the range of the hazard." definitive. No evaluations are provided. 1263. Lines Please explain what will need to be done if in the future the hazard model is changed. For example, Text revised (also added to Chapter 15, 360-will an evaluation of the GMC model need to be redone because its validity was based, in part. on the section on DCPP application) 361 hazard calculated from a specific hazard model (i.e., hazard-calibrated)? If that is the case. it is important that such a caveat be clearly communicated in the report. Please note that there are other instances in this and other chapters where hazard was invoked as demonstrating that the range in the models is adequate, which should also be included as part of this comment. 1264. Lines Please explain why the versions of the candidate GM PEs with added epistemic uncertainty are not That's already shown in Figures 8.4-18 and 367-considered in the comparison. 19. No change in the text. 370 1265. Line Figure 8.4-7 is missing or skipped over. Please correct this oversight. Done 388 1266. Figure Please correct the weight for "Sim_DC-MED, (i.e., shouldn't it be 0.25?). Done 82-2 1267. Line In Figure 8.4-1, please provide labels for the color legend bars and define what the light grey ellipses Done (besides for bar labels) 522 and points represent. 1268. Line In Figure 8.4-2, please provide labels for the color legend bars and define what the light grey ellipses Done (besides for bar labels) 533 and points represent. 1269. Line In Figure 8.4-3, please explain what DCPP Model A is, given that there appears to be only one DCPP Caption augmented to clarify the meaning 547 model 1270. Line In Figure 8.4-6, there does not appear to be any "dashed black" lines. Please revise the caption to Dashed black lines are already in the figure. 569 refer to the actual color scheme used in the figure. No change applied 1271. Line In Figure 8.4-8, there does not appear to be any "dashed black" lines. Please revise the caption to Dashed black lines are already in the figure. 580 refer to the actual color scheme used in the figure. No change applied 1272. Line In Figure 8.4-9, there does not appear to be any "dashed black" lines. Please revise the caption to Dashed black lines are already in the figure. 594 refer to the actual color scheme used in the figure. No change applied 1273. Line In the Figure 8 4-14 caption, please describe what models the phrase "individual models" refer to Qualifier "representative suite of common-645 form models" used instead than "individual models" 1274. Line In the Figure 8.4-15 caption, please describe what models the phrase "individual models" refer to. Qualifier "representative suite of common-651 form models" used instead 1han "individual models" 1275. Line In the Figure 8.4-16 legend, please refer to the various models by the acronyms used throughout the Done 656 report (e.g., ASK14 instead of ASK). 1276. Line In the Figure 8.4-17 legend, please refer to the various models by the acronyms used throughout the Done 662 report (e.g., ASK14 instead of ASK). 1277. Line In Figure 8.4-18, please define what the light grey lines represent in the legend or the caption. Explanation is in the caption 665 1278. Line In Figure 8.4-19, please define what the light grey lines represent in the legend or the caption. Explanation is in the caption 670 CHAPTER 9-Median GMC Models: PVNGS Sources 1279. Line 38 Please follow the standard practice of numbering figures in the order in which they are first called in Figure 9. 1-2 is correctly called on line 37 in the text, which is not the case with the figure called on this line. the Draft Rev1 documents. No change in the text 1280. Line 54 Chapter 6 of this report and the report on the SSC model use the term "virtual faul1". rather then Fixed "pseudo fault." Please revise for consistency with those other usages. 1281. Lines The Akkar et al. (2014a,b) and Bindi et al. (2014a,b) GMPEs were developed using subsets of the Paragraph added to clarify this point 74-75 RESORCE strong-mo1ion database under the auspices of the SIGMA project. Please indicate that these two models are likely correlated, although perhaps not to the extent of the NGA-West2 models. Please also note that this is not an issue, since epistemic uncertainty was applied to these models as well as to the NGA-West2 models. 1282. Line Please specify the type of "residual" (i.e .. between-event). A qualifier was already applied to each 108 "residual" entry in the Draft Rev1 document. No chanae in the text 1283. Lines The sentence beginning "The limitation .. " is confusing. Please reword it or expand it to make its We assume this is line 149 Sentence 173-meaning clearer. reworded. 174 1284. Line Please make it clear which mechanism each of the weights refers to. We assume this is line 163. Sentence 187 reworded. 1285. Line Please correct the figure reference; the reference to Figure 9.1-10 should actually be to Figure 9.1-9. We assume this is line 232. Figure 256 reference fixed. 1286. Line Please correct the figure reference on this line (it should be 9.1-19). The comment does not match the line 371 number in Draft Rev1 Chapter 9. We do not understand comment 1287. Lines Please indicate where the technical justification and bases for these statistical weights are given (i.e .. The comment does not match the line 475-Appendix P). number in Draft Rev1 Chapter 9. 476 We highlighted references to Appendix P already in the text 1288. Lines The stated justification seems weak; there are few recordings at 200 to 400km distance range in the Paragraph expanded to clarify this 478-ground-motion database. On the other hand. it would appear that there is no need to consider comment 481 directivity because its effect, as modeled in CY14, is zero at such large distances. Please revise to clarify the justification for the Tl Team's judgment. 1289. Line In the heading of the last column in Table 9.1-1, please replace the term "SFO" with "SOF" to Done in Chapter 8 and 9 545 represent style of faulting. 1290. Line In Figure 9.1-2a, please label the color legend bars and describe whal the light grey ellipses and Done (besides for bar labels) 557 circles are on the plots. 1291. Line In Figure 9.1-2b, please label the color legend bars and describe whal the light grey ellipses and Done (besides for bar labels) 567 circles are on the plots. 1292. Line In Figure 9.1-3a, please label the color legend bars and describe whal the light grey ellipses and Done (besides for bar labels) 577 circles are on the plots. 1293. Line Figure 9.1-3b. please label the color legend bars and describe what the light grey ellipses and circles Done (besides for bar labels) 587 are on the plots. 1294. Line Please provide a specific reference to "Akkar et al." Unique subset ID is used (EUR*v Meo) 607 1295. Line In Figure 9.1-8, the plots do not appear to have any "dashed black lines. Please revise the text to Dashed black lines are already in the figure. 637 better describe the lines. No change applied 1296. Line In Figure 9.1-9, the plots do not appear to have any "dashed black" lines. Please revise the text to Dashed black lines are already in the figure. 645 better describe the lines. No change applied 1297. Line In Figure 9.1-10, the plots do not appear to have any "dashed black" lines. Please revise the text to Dashed black lines are already in the figure. 653 better describe the lines. No change applied 1298. Line In Figure 9.1-11, the plots do not appear to have any "dashed black" lines. Please revise the text to Second part of the question is now 661 better describe the lines. Please also further justify in the text why it is acceptable for some of the addressed in Chapter 6 in response to Tier predictions from the GMPEs to fall outside of the range of the representative models at some periods. t comments. Note the concern in previous comments of using only the hazard distribution alone to justify the range in the representative suite of models. Dashed black lines are already in the figure. No chanae aaalied 1299. Line In the Figure 9 1-13 caption, please describe what is meant by "individual models," and consider First part clarified, 709 making changes such that the upper and lower parts of the figure have the same vertical scale. Second part will not be done for this revision 1300. Line In the Figure 9.1-14 caption, please describe what is meant by "individual models." Done 714 NOTE: in this and other similar cases, the exact figure matching the comment line was not found, but corrections have been applied to all figures captions where applicable 1301. Line In the Figure 9 1-15 caption, please describe what is meant by "individual models." Done 718 1302. Line In the Figure 9.1-16 caption, please describe what is meant by "individual models." Done 724 1303. Line In the Figure 9.1-17a caption, please describe what is meant by "selected models." Please consider Done 729 using a consistent set of tenninology for the different types of models that are described throughout the report to make it less confusing to the reader. Please also use a consistent set of acronyms in the leoend (e o, ASK14 instead of ASK). 1304. Line In the Figure 9.1-17b caption, please describe what is meant by "selected models." Please also use a Done 738 consistent set of acronyms in the legend (e.g., ASK14 instead of ASK). 1305. Line In the Figure 9.1-18a caption, please describe what is meant by "selected models." Please also use a Done 742 consistent set of acronyms in the legend (e.g., ASK14 instead of ASK). 1306. Line In the Figure 9.1-18b caption, please describe what is meant by "selected models." Please also use a Done 748 consistent set of acronyms in the legend (e.g., ASK14 instead of ASK). 1307. Line In Figure 9.1-19, please use a consistent set of acronyms in the legend (e.g., ASK 14 instead of ASK). Assuming it refers to Figures 9.1-17 or 9.1-759 18 Done 1308. Figure Please correct the abbreviation for the Idriss (2014) model to be consistent with usage elsewhere in Fixed 9 2-t the report. CHAPTER 10-r Model Logic Tree for both DCPP and PVNGS 1309. Lines Please also mention that the standard deviations of ASB 14 and Bi14 are independent of magnitude. Done 25-26 which was an important property of the models that the Tl Team used to reject them. 1310. Line 38 Although the use of the term "proponent" in this context is technically correct, it is inconsistent with the Done term **candidate" used throughout the report to identify such proponent models Please consider replacing "proponent" with "candidate" to be consistent with the description of such models throughout the report. 1311. Line 47 Please add the term "scaled" before "Chi-square distribution." Done 1312. Lines The three-point approximation scheme (as described in Appendix P) applies (0.2, 0.6. 0.2) weighs to Discussion added in Appendix P 51-53 the (5th, 50th, 95th) percentiles. Please explain the appropriateness (or point to a place where such explanation was given) of giving a 0.6 weight to the central branch representing the mean (which may not be the 501" percentile of a Chi-square distribution} CHAPTER 11-cj> Model Logic Tree: DCPP 1313. Line 27 Please clarify if interpolation and extrapolation were also needed for the California-only data subset, Done. The issues does not exist for the which includes data at the full set of spectral periods. California data 1314. Line 53 Statistical evaluation of the standard error of .Pss was not given in Appendix P. Please verify and correct Reference to Appendix P is now removed the cross reference as needed. 1315. Lines Please refine this paragraph to give a clear and accurate summary of the approach described in Entire paragraph rewritten 53-58 Section 7.3.1. 1316. Line 64 Please qualify the term "correlated" in a way that is similar to Lines 4-5 of Chapter 12. Done 1317. Line 71 Please consider revising the term "intra-event" to "within-event" to be consistent with the terminology Done throughout the chapter generally used throughout the report. 1318. Lines Please define the level of significance for the presumed departure from normality. It might be obvious Sentence added to clarify this point 78-79 to the Tl Team, but not necessarily to the reader, that a point falling outside the 95% confidence and 88-interval can be considered to depart from normality at the 5% level of significance. Besides, others 89 mioht consider "sionificant" to be at the 10% level of sionificance 1319. Line Please be specific whether the same weights of the mixture models that were found to be appropriate Discussion expanded to clarify this point. 105 for CY14 are "similar" or the "same" as found for ASK t4. The same weights are adequately fit the data. 1320. Lines Please provide a context for this paragraph. Paragraph deleted 108-112 1321. Line Please insert a space after 4'-Done 127 1322. Line Please consider revising the term "intra-event" to "within-event" to be consistent with the terminology Done (See reply to 1317) 133 used throughout the report. 1323. Line In the Figure 11-2 caption, please consider revising the term "intra-event" to "within-event" to be Done 188 consistent with the terminology used throughout the report and define the meaning of the term "normalized." Please also define the solid and dashed red curves. In addition. note that panel b) is stated as being for T=2 sec, but the y-axis label indicates it is for T=0.5 sec. Please correct this inconsistency. 1324. Line In the Figure 11-3 caption, please describe what type of "residuals" are referred to in this figure. Done 191 Please also define the solid and dashed red curves. 1325. Line In the Figure 11-4 caption, please describe what type of "residuals" are referred to in this figure. Figures not revised due to paucity of time 194 Please also define the solid and dashed red curves and provide the missing red curves on the right plot. 1326. Line In Figure 11-5, both of these plots appear to be incomplete and the left plot is not consistent with the Figures not revised due to paucity of time 201 right plot. Please correct these plots to be consistent with other similar plots in the chapter. 1327. Line In Figure 11-6, both of these plots appear to be incomplete and the left plot is not consistent with the Figures not revised due to paucity of time 212 right plot. Please correct these plots to be consistent with other similar plots in the chapter. 1328. Line In Figure 11-7, both of these plots appear to be incomplete and the left plot is not consistent with the Figures not revised due to paucity of time 218 right plot. Please correct these plots to be consistent with other similar plots in the chapter. CHAPTER Models Logic Tree: PVNGS 1329. Lines The first paragraph appears to be awkwardly placed. Please consider placing this paragraph in a more Paragraph moved to second position. 3-5 appropriate place in the chapter. 1330. Line 45 Please remove the reference to DCPP, since this chapter addresses the Phi model for PVNGS. Done 133t. Line 69 Please correct "biased-corrected" to "bias-corrected." Done 1332. Line 90 Lines 486 and 487 on Page 7-16: CV=0.17 of .PsP-* was based on the variability and the mean of Paragraph rewritten for clarity estimates for the four individual GMPEs. Please clarify or correct the statement "based on sample size" in the case of <J>_. .*. 1333. Line Please replace "02" with "0.2." Done 146 CHAPTER 13-Total Sigma Model 1334. Genera The use of the term "total sigma" instead of the more accurate "total single-site sigma" tends to neglect The term is intentionally used generically as I the fact that only a single-site sigma model was adopted. Please consider replacing the term "total two types of total sigma values are in fact sigma" with "total single-site sigma" to emphasize this point. generated, one for the single station sigma and one for the similar path to a region. These are indicated by the appropriate subscripts on o. No chanoe needed 1335. Line 7 Although the Greek letter "1p" and the Greek symbol "fj>"both represent Phi, it is common in engineering q> was replaced with ¢ seismology to use the latter, which has also been used elsewhere in this report to represent Phi. Please select one of these lettersfsymbols to represent Phi and use it consistently throughout the report in order to avoid confusion. 1336. Line 10 Eq ( 13-1) is very generic and does not represent the actual aleatory variabi lily models that are The equation is intentionally generic as proposed. Please consider replacing this equation with two equations: one that represents the total described in the subsequent paragraphs. sinole-site sioma without path terms and one that reoresents the total sinole-site sioma with path (see response to 1334} terms, as discussed in the text that follows the equation. 1337. Lines Although the use of only a total [single-site) standard deviation epistemic logic tree is conceptually fine. They would use the phi and tau models 30-31 it appears to prevent the ability to test the sensitivity of the hazard results to the individual between-given in chap 10, 11, and 12 event and single-site within-event epistemic uncenainty models. Since sensitivity to each type of model is provided in Chapter 14, please explain how someone else can test this sensitivity given that the final model presents only a sinqle total [sinqle-sitel siqma model 1338. Line 55 Please replace the term "cumulative distribution" with the more accurate term "'cumulative distribution Done function" 1339. Line 57 Please add a sentence to explain the utility of Eq (13-3). The sentence below has been added The cumulative distribution function is used to develop the discrete approximation used in the logic tree formulation to represent the uncertainty in the variance parameter 1340. Line 61 Please correct the missing factor of two in Eq ( 13-5) (this typographical error is noted here just as a Done reminder; it has already been noted by the Tl Team). 1341. Lines Please further describe these analyses or provide a reference where the results of these analyses can Appendix P. Section P.3 62-63 be found. 1342. Line 66 Please correct a possible typo: should oss be changed to Corrected 1343. Line 75 Please correct a possible typo: should be changed to oss? Corrected 1344. Line 77 Please correct the typo ("bi-linear") and add the missing word (i.e., missing "to" in "leads to"). Done 1345. Line 79 The Tl Team responded to PPRP's Comment 175 by adding the sentence "Appendix P presents They are provided at the bottom of page P-typical exam pies of the calculations." However, such exam pie calculations were not given in Appendix 1 P. Please provide these missing calculations. 1346. Lines To be consistent with the usage in the embedded table on Line 93, please consider adding subscript Subscript and consistent notation is used 89 and "SS" to symbol o. 90 1347. Line 90 Please assign the embedded table a number and a title so that it can be referenced by table number if Fixed throughout the Chapter needed, and correct any subsequent table numbering as necessary. 1348. Lines Please explain why directly computed CT" at magnitudes between M 5 and M 7 at 0.1 units were not The tri-linearfolTn for sigma is linear 98, 99 and used in fitting Eq (13-8)? interpolation. 100 1349. Lines Please provide a reference for the statement beginning "Minimization of the difference ... ". Reference provided (Appendix I of EPRI, 102-2004) 103 1350. Line Please check the correctness of the reference to Section 13.1; should it be Section 13.2? Yes. Corrected 118 1351. Line Please clarify whether "the method refers to the semivariogram analysis method (Le .. the current Done 154 sentence construction leaves some ambiguity). 1352. Line The Tl T earn presented its evaluation and decision on the modeling of the effects of spatial correlation Paragraph inserted to address the Tl 160 on cr" for the magnitude-independent cr" model only. Please also provide discussions for the Team's evaluation of the magnitude-magnitude-dependent ass models. independent model. 1353. Line Please repair the typos on this line. Done 184 1354. Lines Please indicate in each figure which branch includes the spatial-correlation effect on oss. The spatial correlation effect is not applied 267, on a branch or branched, but by skewing 270 the weights towards the upper branch. Text and added 273 CHAPTER 14--Hazard Sensitivity 1355. Lines It appears awkward to state that the hazard sensitivity analyses for the final GMC model was done on Caveat integrated with the edits done in 7-8 preliminary versions of the SSC models without providing some sort of caveat. This can be avoided by response to previous comment 682 stating that it is the responsibility of the individual NPPs to conduct thorough sensitivity analyses for their individual sites and that the sensitivity results provided herein are for demonstration purposes and for purposes of making hazard-informed decisions. 1356. Line 60 There is no mention of deaggregation in the introduction to this chapter. Please introduce this concept Sentence inserted in the general and discuss what it is used for in the introduction to the chapter prior to presenting the deaggregation introduction results. 1357. Line 81 Please add the term "mean" before "hazard level" to be clear that the results represent the mean and Done, clarification added in the general not some other fractile (e.g., the median) hazard. Hazard is used without prefacing it by mean many introduction times throughout the chapter. If mean is not added to all of the instances where the hazard level is mentioned, then please state that this is the case for the remainder of the chapter in order to avoid confusion. 1358. Line 88 Please consider rewriting the caption (i.e., the "hazard at hazard" juxtaposition somewhat obscures the Captions changed. Now they read meaning). "Deaggregation of reference site condition (Vs30 of760 mis) hazard at mean annual. .... " 1359. Line Please define the term "sensitivity case" and be as specific as possible about what figure(s) are being Done 103 referenced in the discussion. 1360. Line The text on this line states that HW Models 5, 11 and 21 were selected for the 0.5 Hz tornado plots, but Fixed 116 the figure legends for the 0.5 Hz cases indicate that Models 5, 13 and 23 were used. Please check and correct as necessarv. 1361. Line Although the sigma model started as separate Tau and Phi_ss models. in the end a single total single-Done 151 site sigma model was used. Please acknowledge that here and describe that the individual Tau and Phi_ss models were used for purposes of the sensitivity analyses. Also describe how the user of the model can conduct a similar sensitivity analysis usinQ their own hazard code 1362. Line This statement implies that "Model 1" is always the central model of the representative suite of models Done 152 lfthere is some numbering convention for these models. please describe that convention. 1363. Line It is awkward that the first sensitivity analysis appears on the fifth line of the tornado plot. Please The discussion follows the order of the 168 consider here and elsewhere in the chapter discussing the sensitivity cases starting with the top line of nodes in the logic tree. The tornado plots the tornado plot and descending down the plot to make the discussion less confusing. are organized with the main effect at the top. 1364. Line The terminology used here is confusing, at best, and doesn't seem to have a useful purpose. The First comment fixed. 247 dichotomy "seismogenic sources" versus "tectonic sources" does not seem meaningful. Why are the Seismic source input is what gets fed into the former not simply called areal sources, since the other type -tectonic sources -are also seismogenic hazard code, so the term has not been sources? Further, in the next line, "Seismic source input" is used; what is the difference between changed. seismic source and seismogenic source? Finally, in Line 251, "areal seismic source" is used. This rrhird comment fixed paragraph needs to be rewritten with consistent. conventional terminology. 1365. Line There is some confusion as lo the use of the term "Sonora Basin and Range. The SSC model uses Done, a footnote was inserted (Rev.2) 266 the term "Southern Basin and Range". Here. you seem to indicate that the "Sonora component of this term is derived from the Lettis (2013) SSHAC2 report. This needs to be made clearer, and ii would also help if it were made clear that this region is now referred to as the Southern Basin and Range, especially as the Mexican Highland Basin and Range is in Sonora. Mexico 1366. Line Baja is not the name of the Mexican State that occupies the northern half of the Baja California Done 270 peninsula. It is Baja California. If this term is in reference to that used in Lettis (2013). please make that more clear by also referencing its current usage as Baja California in the SSC report. 1367. Lines Some of the faults have "fault" in their listed name, whereas others do not. Is there a reason for this, Done 274-and if so, please explain. Alternatively, make them consistent. 302 1368. Line Please describe what is meant by the term "wider tail" in this context. Done 401 1369. Line Here it states that the discussion will only address the 0.5 Hz SA sensitivities. whereas in the following References to the 5 Hz figures are removed 449 text, the figures addressing the 5 Hz sensitivities are also cited (Lines 462-463, 466 and 477). Please clarify. 1370. Lines Please be as specific as possible about what figure(s) are being referenced in the discussion. Please Care applied to address this request 451-also be more specific when describing the sensitivity cases. For example, the first sentence mentions throughout the chapter. 452 "the first sensitivity analysis" and the second sentence mentions "these sensitivity cases," without indicating how these two descriptions are related. Since there are a lot of repetitive statements in the text describing the sensitivity analyses and/or sensitivity cases. this comment applies throughout the chapter; please make it clear what sensitivity analysis and/or case is being discussed at any given time and where that analvsis andfor case can be found on the tornado clot. 1371. Line Section 7.4.1 does not include a discussion of additional epistemic uncertainty at large magnitude. Correct section provided 465 Please provide the correct cross-reference. 1372. Line Please add "types" between "two" and common form models" in order to avoid confusion. Done 468 1373. Line Please clarify what "Model 1" refers to on this Ii ne. That is the same approach followed in 506 Section 14.2.1. Model 1 is the central model in the ellipse. A qualifier has been added 1374. Line Please consider replacing the term "average" with the term "central" so as not to imply that it is Sentence edited 510 intended to represent the mean (average) hazard. 1375. Line Figure t4.3-tOa is cited on this line, but the discussion appears to refer to the case shown in Figure Done 511 14.3-9. Please check and correct as appropriate. 1376. Line Figure 14.3-9b is cited on this line, but the discussion appears to refer to the case shown in Figure 14-Done 517 10a. Please check and correct as appropriate. 1377. Lines Please add "types" between "two" and "common form models" in order to avoid confusion. Done 594-595 1378. Lines Figures 14.3 (a and b) are cited, but in Line 605, it is stated these would not be discussed further. Fixed in both instances 609 Please clarify. and 617 CHAPTER 15-Application Guidelines and Limitations 1379. Line 5 Please provide a cross reference to the adopted kappa value of 0.041s. Reference added to Section 5.3.3 and Appendix M 1380. Lines Please provide a cross reference to the section where evaluations are presented to support the claim Discussion added 5-8 that epistemic uncertainty in kappa is captured by the variation in high-frequency spectral shape within the SWUS GMC common-form models. 1381. Lines Please give the purpose for providing a representative Vs and density profile and what they can or Discussion added 12-14 should be used for, or delete this discussion from the report. Without such a statement of purpose, it is ambiguous why these profiles are presented. For example, if they are provided for purposes of documentina what was used to estimate the host kappa values for the NGA-West2 GMPEs, then their discussion should be part of the appendix that discusses the host kappa value determination. If they are meant to be representative of the site response predicted by the site terms in the NGA-West2 GMPEs, that has not been shown to be the case for these GMPES and is certainly not the case for the Eurooean or Jaoan GMPEs, which are likelv reoresented bv totallv different Vs and densitv orofiles CHAPTER 16-References 1382. Please carefully review these references for completeness and accuracy and for consistency with the Done (partially in Rev.1. completely in references provided in each chapter Rev2) Comment Response Table Comment Location in Text PPRP Comment Summary of Revisions to Report Number CHAPTER 1-xxxx CHAPTER 2-xxxx CHAPTER 3-xxxx CHAPTER 4-Seismotectonic Setting Lines 163-164 These lines refer to two categories, namely "the California and Mexico faults (referred to as Regions 1 and 2&3 in this Report)," and "other faults (AZ.NM, NV, and Mexico)" Table 4.2-2 has rows for "CA Faults" and "AZ., NV, & Mex Faults." Do the rows of the table correspond to the two categories of faults described in the text? If so, please align the teminology; if not, please clarify Lines 172-179 The legends of Figures 4-8a and 4-8b are not well correlated with the text. For example. "NSHMP faults" are noted in the legends but are defined neither there nor in the text. And the text calls attention to the dominance of distant fault sources for low frequency at 1 o** AFE, but the Figures do not identify the curves associated with "distant fault sources." Please reconcile the figure legends and text. CHAPTER 5-Ground Motion Databases and Candidate Models General Two references for Kishida et al.. 2014a and 2014b. appear in the reference list. However, many of the citations in this chapter refer only to Kishida et al (2014) without distinguishing 2014a from 2014b. Please check and correct this omission. General The figure numbering scheme seems to be inconsistent in this chapter. For example, Figure 5.2.2-2 is called in Section 5.2.2.1, indicating the convention that only the chapter number and first two section levels prefix the sequence number. But a Figure 5.2. 3.4-1 is called in Section 52 3.4. so in that case all three section levels prefix the sequence number. There are some other anomalies as well. Please check carefully and ensure that numberinQ is done consistently throuQhout. Line 47 Please add that the bottom frames also show the number of recordings per site class. Line 85 There is no sign in Figure 5.1.2-1 of "Station Z14A, shown by the open star". Please clarify. Line 87 Please complete the citation of "Kishida" (i.e .. Kishida et al. 2014a or 2014b?). Line 158 Please correct the figure number on this line, which should be Figure 5 1 5-1. Lines 173-174 The spelling of the fault names differs between the text and Figure 51.5-2 ("ltozawa" in the figure becomes to "ldozawa" in the text, and "Yunodake" in the figure becomes "Yunotake" in the text). Please edit for consistency. Lines 175-176 The total moment given here and attributed to personal communication is inconsistent with the moment magnitude of 6.7 given for this event on Line 164 (the sum of the moments on Line 175 imply M 6.56). Please resolve the inconsistency. In doing so. please consider whether it would be appropriate to cite published moment estimates (e.g., Tanaka et al. 2014, report a moment consistent with M 6.7 and approximately equally partitioned between the two faults) instead those reported from personal communication. Line 202 Please supply the missing Table 5.1.7-1. Line 216 Ku is undefined at this point in the text. Please correct this. Line 223 Please consider whether a more appropriate characterization than "upper bound" can be used here (e.g .. is that categorical statement even consistent with the one standard deviation ranges cited for the other methods?). Line 228 Please include a reference to a publication describing the SCEC BBP (e.g., the paper by Maechling et al. in the Jan/Feb 2015 SRL may be aporooriate ). Line 242 Please consider citing the published paper by Dreger et al. (2015) in the Jan/Feb 2015 SRL Lines 264-266 It is appropriate for the Tl Team to rely on the SCEC Validation Review Panel for the technical analysis of the simulations. and to rely upon the judgment of that panel to determine which methods met the acceptance criteria established in that review. However, the Tl itself needs to justify that meeting those acceptance criteria makes the methods suitable for the specific purposes for which the simulations are to be employed. Those purposes are stated on Lines 227-233. Please augment the summary statement on Lines 264-266 explaining how meeting the SCEC review panel's acceptance criteria makes the simulation methods suitable for addressing the problems laid out on Lines 8-14. Lines 306-315 This passage needs rewriting because: 1) the BSL model is not identified as GIL7 on Line 309, but seems to be the same as what is called GIL7 in the legend of Figure 5.2.2-1 and then on Line 312; and 2) the passage is repetitive (e.g., the verbiage about routine estimation of moment tensors on Line 309 is repeated on Line 314-315; the basis of the GIL? model in broadband waveform modeling is stated repetitively on Line 308 and then on Line 314). Line 322 "Frequency wave-number" is written differently on this line than it was on Line2 304 and 311 ("frequency-wave number"). Please review the hyphenation convention and apply one consistently (note also that both "wave number" and "wavenumber" are in common use, so the easier-to-read form "frequency-wavenumber" is also an option). Line 361

• 364 "Area" is used to signify rupture area in Equation 5.2.3-1, but 'A" is defined as rupture area on Line 364. Please edit for consistency. Line 383 Please correct the figure number. It is called out as Figure 5.3.2.1-1 on this line, but the figure itself is labeled as Figure 5.2.3.1-1. Moreover. the numbering scheme used elsewhere in the report seems to call forit to be called Figure 5.2 3-1. since it occurs in a subsection of Section 5.2.3 (e.g., by analogy with the fact that Figures 5.2.2-t and 5.2.2-2 occur in Section 5.2.2.1 ). Line 392 The figure number 5.2.3.2-1 is inconsistent with fact that it is the second figure in the subsection. Please check the figure numbering convention and make it consistent with the rest of the chapter and report. Line 452 The table called Table 5.1.1-2 on this line appears to be the table labeled Table 5.1-2 (and called by those numbers elsewhere in the reoortl. Please correct here and in subseauent occurrences. Line 464, 475, 481 Line 464 gives the distance criterion for NGA-W2_DC-MED as abs(Rx)<70km. whereas the lines 475 and 481 give R<70 km, which is more restrictive. Please clarify how the various distance metrics are used toqether to screen records for NGA-W2 DC-MED. Line 506 Previously. Akkar et al. (2014c) was cited as the database reference. Please check whether the citation given on this line is correct in the present context. Lines 508 and 517 The criterion abs(Rx)<70 km leaves the total distance unconstrained. Please provide a complete statement of the distance selection criterion.

Line 548 Please consider whether this might be a good place to introduce the symbol .Pss. so that it will be defined prior to its use on Line 553. Line 558 "Disaggregation" is used on this line, whereas "deaggregation" is used elsewhere in the report. Please edit for consistency. Lines 565-572 The selection criteria (distance. magnitude, number of recordings per event and site) do not seem to be given. Please check and correct if necessary. Line 566 "NGA-W2" is "NGA-West2" elsewhere. Please edit for consistency. Line 579 Please check whether "for use in should be "is used in". As is. the sentence lacks a verb. Line 585 Please add the missing parenthesis closure. Line 601 Section 5.4.1 does not contain the discussion of the Idriss 2014 model that is referenced here ("As noted in Section 5.4.1"), nor does there appear to be any prior reference to the Idriss model in the chapter. Please make the necessarv corrections. Lines 619 and 626 Line 619 has the statement that "the global dataset in this magnitude and distance range consists of 264-415 recordings from 4 to 23 earthquakes." Line 625 states "Within this magnitude and distance range, the global dataset contains four earthquake and 280 records." Please clarify why these statements are not contradictory. Line 627 The cited figures do not exist. Please add them. Line 669-670 Please correct the figure references (they should be to Figures 5.5.1-1 and 5.5.1-2). Line 673 Please correct the figure reference (it should be to Figure 5.5.1-3). Line 683 Please correct the table reference (the intended reference appears to be to Table 5.5.1-1). Line 724 Please clarify why specific scenarios had to be specified. given that kappa is not being explicitly modeled as a source effect. Line 727 Please consider rewording the reference to "Q attenuation." to avoid the implication that the kappa effect is necessarily physically distinct from effects ordinarily parameterized in terms of Q. Isn't the point that the kappa parameter (or at least Ku) is intended to capture attenuation effects that are so localized that in a practical sense they are better parameterized as site terms than as path-dependent attenuation terms. and that therefore isolation of kappa effects requires short-distance scenarios? Line 730 Please be more specific about which profile was used. Is it one of those in Figure 2.6 of Kamai et al (one is listed as having Vs30 of 750 mis. none has exactly 760 m/s )? Line 735 Figure 5.5.3-1 appears to be labeled incorrectly. Please correct this. Line 778 Rodriguez-Marek (2013) actually developed four single-station sigma models: one with neither M nor R dependence, one each with M and R dependencies, respectively, and a fourth with both M and R dependence. Please clarify which three have been chosen. and why. Note also that there is a perception of ambiguity introduced by mixing "dependent" and "independent" in listing the attributes of the selected models; i.e .. Is the "maqnitude-independent" model alluded to also R independent (in which case it would be clearer to say "magnitude and distance independent), or is there a typo such that "magnitude-dependent" is what is actually intended? If one of the figures were not missing, this ambiguity would be cleared up, but it would be better to also do so in the text. Lines 779 and 781 Please check whether the first of the three models alluded to should be "magnitude-dependent" (rather than "magnitude-independent", which would appear to be inconsistent with the figures). Alternatively, if "magnitude-independent" is correct as written, please clarify whether it is paired with a distance dependence or Lines 780-782 Only the R-dependent and MR-dependent models are shown. and these are in Figures 5.6.2-3 and 5.6.2-4, respectively (not 5.6.2-4 and 5.6.2-5 as called in the text). The other model (called "magnitude-independent" in the text) is not shown, nor is there any Figure 5.6-5. Please correct this. Line 789 Please cite a reference for the assertions about the small-magnitude limitations of GMPEs at short distance. Figure 5.1.3-1 The caption cites Akkar et al. (2014a and 2014b), whereas the text (Line 121) cites Akkar et al. (2014c), apparently in the same context. Please check whether this difference is intentional and make a correction if aooropriate. Figures 5.2.3.4-1 and These figures are mislabeled (as 5.2.3.3-1 and 5.2.3.3-2, respectively). 5.2.3.4-2 Please correct. Figures 5.3.2-1 and Please correct these figures: in each of these figures. the second row 5.3.2-2 repeats the first with a scale change, and the remaining plots (recordings per site, recordings per event, etc) are absent. Figure 5.5.3-1 Please correct the figure number. It is called as Figure 5.5.3-1, but labeled 5.5.3-2. Figure 5.6.4-1 Please add the dataset identifiers given in Line 805-808 of the text (Blea, Blea2, and ABR) to the figure caption, or else delete them from the text, as the inconsistency is confusing. CHAPTER 6-GMC Models for the Median Line 40-41 Please reconcile the statement that the finite-fault simulations "all show saturation at short distances" with the statement on Line 697 of Appendix J (and evidence in Figure J.4.3-1) that "the GMPEs have stronger saturation than the EXSIM model at very close distances." If it is correct that EXSIM has less saturation at short distances, please explain why this should not be interpreted as support for the Id 14 model (e.g., is the formulation of EXSIM such that it is not intended by its developers for use at the shortest distances? Or does the Tl Team argue on physical grounds that EXSIM is not reliable at short distances?). Line 105 Please hyphenate "large-distance attenuation" to resolve the otherwise ambiguous meaning. Line 303 Figure 6.3.2-5 shows CB 14 having a step-like change in its HW factor as Rjb approaches zero along the strike direction. As already requested in comment 978, please clarify how this is consistent with the claim that CB14 allows "a smoother transition" around the rupture compared with some other models. Lines 506-513 Please justify (as requested previously, Comment 389) how it is mathematically possible with the addition of the interpolated GMPE qround motions to better capture the correlations. Line 524 Please be precise about what "standard deviations" are plotted in Figure 6.4.3-1. Lines 536-543 This explanation needs to be set out more clearly. The sentence beginning on Line 536 says "for the DCPP application ... the central HW branch is applied to all common-form models." The rest of the passage, although rather difficult to read, appears to indicate the following: ( 1) HW effects are omitted from the 2000 models used for the Sammon's map, (2) the central HW model is appended to those footwall models, solely for the purpose of the simplified hazard calculations used in the selection of representative common-form (footwall) models from the original 2000, and (3) randomly selected HW models (from the equal-probability set developed in Section 6.3.2) are appended to the selected representative set of footwall models, to give the final set of common-form models for application to DCPP If this is a correct interpretation, then the last item seems to contradict the sentence from Line 536 (and if this is not a correct interpretation, some clarification is needed). Please rewrite for clarity and consistency. Lines 616-618 How can one Ztor value be used if the models do not include Ztor at all? Line 629 Please correct the spelling of second occurrence of "PVNGS." Line 632 Please check whether the intent of this sentence would be more clearly expressed if the final clause were included inside the parentheses. Line 633 It appears from Eq. 6.4-4 that it is the contributions to the Euclidean distance squared that are weighted by the weights from Eq. 6.4-7 (not the contributions to the Euclidean distance itself. as stated). Please correct or clarifv. Line 704 Please correct the typo, i.e., "two week" should be "loo weak." Line 879 Two consecutive figures are called "6 4 5-8." Please check and renumber as needed. Figure 6.7.2-2 Please label the vertical axis. Figure 6.7.2-3 Please identify the GMPEs associated with the respective colors, and make improvements to the legibility of the figure (note also that the figure did not appear in its entirety in the supplied pdf version). Figure 6.7.2-5 Please label the vertical axis. Figure 6.7.2-6 Please identify the GMPEs associated with the respective colors. CHAPTER 7-GMC Models for the Sigma: Overview and Methodology Line 84 Please add the missing words in this sentence (which currently reads "and chose through the"). Line 197 Please rewrite the final sentence of the paragraph to clarify its meaning (i e . a "value" cannot be similar to a "model," so it is not clear what point the sentence is trvino to convevl. Line 273 Please correct the inconsistency between the phrase "shown . . . for four spectral periods" and the list "(PGA, 0.1,0.5, 1.0.3.0 sec)," which (like the figure itself) includes five periods (PGA in addition to the four given spectral periods). CHAPTER 8-xxxx Section 8.2.2, There does not appear to be a reference to Figure 8.2-3 Please check general comment and add a reference lo this figure if one is missing. Line 167 Please improve clarity by adding a sentence break after the word "model." Figure 8.2-2 Please correct the weight for "Sim_DC-MED," (i.e., shouldn't it be 0.25?). CHAPTER 9-xxxx Line 38 Please follow the standard practice of numbering figures in the order in which they are first called in the text, which is not the case with the figure called on this line. Line 54 Chapter 6 of this report and the report on SSC model use the te1111 "virtual fault", rather then "pseudo fault." Please make a change for consistencv with those other usaaes. Line 371 Please correct the figure reference on this line (it should be 91-19). CHAPTER 10-xxxx NO COMMENTS CHAPTER 11-xxxx NO COMMENTS CHAPTER 12-xxxx NO COMMENTS CHAPTER 13-xxxx Line 61 Please correct the missing factor of two in Eq 13-5 (this typographical error is noted here just as a reminder: it has already been noted by the Tl Teaml. Line 77 Please correct the typographical error {"bi-linear). CHAPTER 15-xxxx NO COMMENTS CHAPTER 16-xxxx NO COMMENTS APPENDIX A-xxxx NO COMMENTS (REVIEWED AT BEGINNING OF PROJECT) APPENDIX B-xxxx NO COMMENTS APPENDIX C-xxxx APPENDIX D-xxxx APPENDIX E-xxxx APPENDIX F-xxxx APPENDIX G-xxxx APPENDIX H-xxxx APPENDIX 1-xxxx APPENDIX J-xxxx General Comment 788 on Rev.O requested editing of the appendix to conform lo the heading/subheading structure of the rest of the report (that is, the request was to number all subsections set off by headers, as in the rest of the report). This was not done consistently; the specific examples given to illustrate the intent of the comment were rectified, but the generality of the comment was not addressed To reiterate that comment: please edit the appendix for uniformity of style (specifically the treatment of subsection numbering) with the rest of the report. Line 50 Please distinguish this lengthy quotation by indenting the entire paragraph. Line 110 It is appropriate that the Tl Team relies on the SCEC Validation Review Panel for the technical analysis of the simulations, and that they rely upon the judgment of that panel to determine which methods met the acceptance criteria established in that review. However, the Tl itself needs to justify that meeting those acceptance criteria makes the methods suitable for the specific purposes for which the simulations are to be employed. Those purposes are stated on Lines 8-13. Please add a paragraph at the end of Section J.1.1 explaining how meeting the SCEC review panel's acceptance criteria makes the simulation methods suitable for addressing the problems laid out on Lines 8-13. Line 499 "PSA here symbolizes "pseudo-spectral acceleration" rather than "peak spectral acceleration." Please correct. and specify that the relevant values are the RotDSO spectra Line 520 The resultant of the summation is called Dip.,.,, in the equation, but is not a root-mean-squared quantity, but rather just a linear average. Please avoid confusion by using a more appropriate symbol for the sum, and also add the explanation that the summation is over the discrete fault elements. Line 526 There should not be a sentence break in this paragraph (the second part is not a complete sentence). Please correct (e.g., by merging the two parts into a single sentence). Line 537 The Figure and Table references on this line appear to be incorrect. Please check and correct them (it appears that they should be Figure J.2.2-1 and Table J.2.2-1 l. Line 538 The Figure and Table references on this line appear to be incorrect. Please check and correct them (it appears that they should be Figure J.22-2 and Table J.2.2-2). Line 543 Please check and correct the Table reference (it appears that it should be Table J.2.2-1) Line 553 Please check the accuracy of the gray curve in Figure J.4 2-1 that has a nearly flat zone from 0.5 to 1 Hz and, if it is correct as plotted, explain why this GMPE is used given this strange behavior. This request was also made as part of Comment 875 on Rev.O. Line 582 The dot colors in Figure J.4.2-3 are not explained (i.e., there is no explanation in the caption or legend of which color represents which GMPE). Please add the missing information, as was already explicitly requested in Comment 876 on Rev.O. Line 591 The comment that Method 2 "produces the lowest factors" appears to be true only at frequencies above about 1 Hz. If that is a correct interpretation of Figure J.4.2-3, please qualify the statement aoorooriatelv. Line 601 The statement that "the magnitude used in the GMPE is computed based only on the area of the closest segment" does not seem to be a correct representation of Method t. Doesn't Method t make two separate GMPE evaluations, using the respective magnitudes of the two segments for the respective GMPE evaluations? Please provide a more precise explanation for the relativelv low around motion factor from Method 1. Line 641 The dot colors in Figure J.4.2-6 are not explained (i.e., there is no explanation in the caption or legend of which color represents which GMPE). Please add the missing information. Lines 696-697 To repeat Comment 888 from the review of Rev.O: Please cite a published report or journal article for the observation that the GMPEs have stronger distance saturation than the ExSim model. Then the result mentioned here (regarding ExSim peak amplitudes) can be stated as a consequence of that fact (perhaps one pointed out by Dr. Atkinson to the Tl Team), rather than something to be taken purely on the authority of an unpublished comment bv Dr. Atkinson. Line 720 Please give the figure number corresponding to the description that begins on this line. Line 730 The dot colors in Figure J.4.3-3 are not explained (i e , there is no explanation in the caption or legend of which color represents which GMPEJ. Please add the missina information Line 909 The clause beginning after the parenthesis is a bit redundant (see Lines 893-894). Please consider deleting it to streamline the text. APPENDIX K-xxxx General comment on Please add a discussion of Figure K.1-6, which is not mentioned in the Section K.1 current text. Lines 6-8 If these are the same datasets defined in Chapter 5 and Table 5.1-4 (as the caption of Figure K .1-1 seems to indicate), please reference that table and aive the corresoondina dataset names here. General comment on Please cite the figures by number and state what is plotted in each Section K.2 Line 54 (Figure K.2-The vertical axis labels do not appear properly (at least in the PDF 1) distribution). Please correct. APPENDIX L-xxxx NO COMMENTS APPENDIX M-xxxx APPENDIX N-xxxx Line 32 Please explain why Figure N-1 seems to show a break in slope at M 7 in the dashed black curve for T=5, given that Equation N-2 only allows slooe breaks at M 5.5 and M 6 5 APPENDIX 0-xxxx APPENDIX P-xxxx Line 7 Please provide a page reference for the cited information in Ang and Tang (2007). Lines 8 and 9 The same symbol is used here for the variate ("-r2 follows a scaled chi-squared distribution") and a parameter of its distribution function ("with mean given by T2) Please remedy this source of confusion (this notational issue was also noted in Comment 174 on Rev OJ. Line 17 The notation does not properly distinguish the variate from its expected value. Please correct this (as was done for, e.g., Eq 13-4 and 13-5). Line 19 "0.6" should probably be "0.63." Please check and correct if necessary. Lines 25 and 26 The same symbol is used here for the variate (<!>1,,/ follows a scaled chi-squared distribution") and a parameter of its distribution function ("with mean given by .P:..i,-R2"). Please remedy this source of confusion (this notational issue was also noted in Comment 174 on Rev.O). Lines 36 and 37 The same symbol is used here for the variate (T2 follows a scaled chi-squared distribution") and a parameter of its distribution function ("with mean given by Please remedy this source of confusion (this notational issue was also noted in Comment 17 4 on Rev 0). Comment Response Table Comment Location in PPRP Comment Summary of Revisions to Report Number Text CHAPTER 1 Introduction Line 4 October? This project extends into February, 2015 Line 10 Should read .. Western U.S. sites. three Western ... " Line 115 " ... central Arizona compared and the path ... " Change and to with CHAPTER 2 Project Organization Line 81 Saint Onofre should be San Onofre Line 200 Change thought to through Line 207 Correct were generally are" -delete one of the verbs Line 241 Correct spelling of draft (drat) Line 260 Correct "tee" to "tree" CHAPTER 3 Work Plan Line 3 Correct spelling of fulfill CHAPTER 4 Seismotectonic Setting Line 77 Delete "of range after "and the range" Table 4.1-4 Include DCPP in the table title Table 4.2-1 Include PVNPP in the table title Table 4.2-2 Include PVNPP in the table title Figure 4-1 The two line colors for the SAF are not clearly distinguished in the figure Figure 4-2 Include "of DCPP" in the figure caption Figures 4-5 and 4-6 Consider combining these figures Figure 4-6 The arrow for Cerro Prieto fault points to the Imperial fault. The CPF is the next bold red line to the SW. Please correct. Chapter 5 Ground motion Databases Line 27 Wasn't the Wells earthquake in the "Northern Basin and Range. Or do you mean that the Wells earthquake provides control for a normal faulting earthquake. if one should occur in the Southern Basin and Range? Please clarify and correct, as needed. Line 85 The "open star is not evident on figure 5. 1 .2-1. And this figure is the "data distribution", not "attributes". Is this the correct figure attribution? Line 276 "were compared to the a suite" Please correct this error. Section 5.2.3.1 Need to cite figure 5.2.3.1-1 in this section -currently not referred to Line 383 Figure should be referenced as Figure 5.2.3.2-1. Please correct. Line413 These figure citations appear correct but the cited figures appear to be mislabeled as Figs. 5.2.3.3-1 and -2. Please check and correct. Lines 427, 431, and These figure citations appear correct but the cited figures appear to 433 be mislabeled as Figs. 5.2.3.4-1, -2 and -3. Please check and correct. Line 452 Table 5.1.1-2 is not provided, or this citation is incorrect. Please check and correct. Line 458 Table 5.1.1-2 is not provided, or this citation is incorrect. Please check and correct. Line 490 Okay. Figure 5.2 3 1-t is finally cited -this needs to be cited earlier, or the figure number needs to be corrected for inclusion in this sec1ion. Line 610 Is "200-30 km" correct, or should it be 200-300 km? Line 627 The figure citations here are incorrect -these apparently refer to Figures 5.4.4-1 through 5.4.4-3 Lines 669 and 670 The figures cited do not appear to be the correct citations -please check and correct. (appear lo be referring to Figures 5.5.1-1 and -2) Line 673 The figure cited does not appear to be the correct citations -please check and correct. (appears lo be referring to Figure 5.5.1-3) Line 683 Table 5.5.2-1 was not provided. Please check this table citation and correct. Line 712 Table 5.5.2-1 was not provided. Please check this table citation and correct. Line 735 Figure citation is incorrect -should this be Figure 5 5.3-2? Or is the figure mislabeled. Lines 780 and 781 Please check that the figure citations correspond to the correct figures, as there appear to be discrepancies between the text, figure captions and figures. Figure 5.2.2-2 The caption should indicate that this is for an M4.7 aftershock to the SS earthquake, as discussed in the text. Figure 5.2.3.1-1 Not cited in the correct location in the text Figure 5.2.3.3-1 and -Check figure numbers 2 Figure 5.2.3.4-1 and -Check figure numbers 2 Figure 5.5.1-1 and-2 The red and dashed lines should be explained in the caption Line 1337 Check if this figure number is correct Line 1344 This caption should be improved to better fit the text Chapter 6 GMC Models For the Median Line116 Remove the extra "D" in ld14 Line 234 Magnitude depth?? Do you mean rupture depth? Line 298 "RO" is RxO in the figures -please correct. Line 487 The phrase in the areal sources in the as shown in ... " is not clear. Please correct. Line 494 "are shown in figures" is repeated twice -please correct. Line 495 Please correct "thought" to "though" Line 704 Correct week lo weak Line 879 Figure 6.4.5-8 should be 6.4.5-9. Also change 9 to 10. Correct both citations in this paragraph. Line 1093 Correct dip-sip to dip-slip (2 cases) Table 6.7-1 Is a 22 km down-dip width consistent with the 15 km max. depth for Hosgri rupture widths? Figures 64 1-4a, 4b, Is the 3*c panel down on the right from Idriss (2014)? If so, correct Sa. and Sb 114 to ld14 for consistency Figure 6.4.4-1 Caption should define what the colored points are. Figure 6.4.5-2b Caption states that the GMPEs are in black. However, the key shows this as a different color. Please correct. Also, make the color schemes the same between 2a and 2b. Line 1637 This should be Figure 64.5-9 Line 1646 This should be Figure 6.4.5-10 Figure 6.6.1-1 This figure should include the DCPP site Chapter 7 GMC Models for the Sigma Line 59 "of the events from events" is unclear -please correct. Line 121 Delete "of' between "distributions" and "kappa" (repeated) Line 183 Figures 7.2.3-3 and 7.2.3-3 should be corrected to 7.2.3-2 and 7.2.3-3 Line 216 "they generally fall within the uncertainty range." Generally? It looks like they mostly do Lines 266-269 This sentence is difficult to understand -please clarify. Chapter 8 Median GMC Models: DCPP Line 125 2000 common form ???? Models? Not clear. Line 257 Weight is stated as 0.25. On figure 8.2-2, both are 0.75. Please check -the figure appears to have an error. Line 285 Figure 8.4-7 not provided. (???) Line 388 Is there a 7 missing? 8.4-7 Please correct. Figure 8.2-2 Under the Data Set node, both have a 0.75 weight -one should be 0.25 Figure 8.2-3 Figure does not appear to be cited in the text. Please check. Chapter 9 Median GMC Models: PVNPP Line 232 Figure 9.1-10? Do you mean 9.1-9?? Lines 342-347 This section seems to just hang, as if not complete. Please add a closure statement on its significance. such as -Consequently, .... Figure 9.1-13 These 2 figures would be easier to compare if they had the same vertical scale. Figure 9.2-1 Idriss 2014 is referred to as 114 -please make consistent with the text. Chapter 10 Tau Model Logic Trees No comments Chapter 11 Phi Model Logic Tree: DCPP No comments Chapter 12 Phi Model Logic Tree: PVNPP Line 146 *'weight of 02 because .. " 02? Please correct this value Chapter 13 Total Sigma Model Line 77 "leads potential"?? Please clarify. Line 90 "the following table"??? What table -this "following table" needs to be assigned a Table ##consistent and in order with the rest of the tables-ie., Table 13-1. Please correct and also correct the numberina in the subseauent tables. Line 154 "using the method" is not clear. Please specify the method. Line 184 Define lnormal or correct this Log normal? Also. correct og to of Chapter 14 Hazard Sensitivity Line 88 Caption of figure 14.2-3 hazard for hazard" is confusing. Do you mean "hazard vs. the hazard at.."? This also applies to the next figure (14.2-4). Line116 States that models 5. 11. and 21 are used for the 0.5 hz case, but figures indicate that models 5. 13, and 23 were used. Please clarify or correct. Line 121 even thought the logic tree .. " Do you mean "even though the logic tree ... "? Line 172 Ration? Do you mean ratio? Line 247 1) "consists of seismogenic sources" Are these not the areal sources, as indicated in the parentheses? Why are these not simply called out as areal sources, as the other type -tectonic sources -are also seismogenic sources. This makes it confusing. 2) Further, in the next line. "Seismic source input" is used -what is the difference between seismic source and seismogenic source? 3) Finally, in line 251, "areal seismic source" is used. This paragraph needs to be clarified in terms of usage of the terms "areal sources", seismogenic sources", seismic sources", versus tectonic sources (which I assume you are referring to specified fault sources) Line 266 There is some confusion as to the use of the term "Sonora Basin and Range. The SSC model uses the term "Southern Basin and Range". Here, you state (I think) that the "Sonora" aspect of this term is derived from the Lettis (2013) SSHAC2 report. This needs to be made clearer, and it would also help if it was made clear that this region is now referred to as the Southern Basin and Range, especially as the Mexican Highland Basin and Range is in Sonora, Mexico. Line 270 Similar comment as above. Baja is not the name of the Mexican State that occupies the northern half of the Baja California peninsula. It is Baja California. If this term is in reference to that used in Lettis (2013), please make that more clear by also referencing its current usage as Baja California in the SSC report. Lines 274-302 Some of the faults have "fault" in their listed name. whereas others do not. Is there a reason for this. aand if so, please explain. Alternatively, make them consistent. Line 449 Here it states that the discussion will only address the 0.5 hz SA sensitivities, whereas in the following text, the figures addressing the 5 hz sensitivities are also cited (lines 462-463, 466, 477). Please clarify. Line 472 1' "sensitivity" of the line -should this be followed by analysis? Preceded by "determination of'? Line 506 What does Model 1 refer to? Not Model A or Model B. Please clarify (label in figure??) Line 511 Figures 14.3-9a and 14.3-1 Oa are cited, but it is figures 14.3-9a and b that you are referring to Please correct the text. unless the figures are mislabeled. Line 517 Same comment as above, but for figure 14.3-9b and 1 Ob -should be 14.3-10a and bat 0.5 hz Line 609 and 617 Figures 14.3 (a and b) are cited, but in line 605, it is stated these would not be discussed further. Why are they cited here? Chapter 15 Application Guidelines and Limitations No substantial comments Comment Response Table Comment Location in PPRP Comment Summary of Revisions to Report Number Text CHAPTER 1 Introduction Lines 51-55 Suggest this sentence be broken into 2 sentences for clarity Line 62 Comma after "site-specific rock condition" Line 91 Suggest putting Q in parentheses Line 149 Fix margins CHAPTER 2 Project Organization Line 13 Suggest comma after "(U.S. NRC, 1997)" Line 35 Set should be plural Line 99 Product should be plural Line 146 Estimated should be estimates Line 155 Suggest comma after Arizona Line 238 Suggest comma after comments Line 240 Suggest insertion of "the" after reviewing Line 252 "shows the dates of the main .. " change "of' to "that" CHAPTER 3 Work Plan Line 9 Suggest insertion of "the" belween "as" and "kick-off' Line 120 Station should be plural Line 125 Suggest comma after "conducted" Line 159 Questions should be plural Line 187 Include should be included Line 224 Suggest insertion of "the" between "In terms of' and "sigma models" Line 238 Insert "to after "prior Line 291 Insert "to" after "pertaining" CHAPTER 4 Seismotectonic Setting Line 60 Ranges should be singular Line 112 and 116 Capi1alize Southern consistently, or use lower case consistently for Southern Basin and Range. Suggest caps. as we have formalized the term SBR Chapter 5 Ground motion Databases Line 37 Suggesl comma after residuals Line 140 Suggest insertion of "the" between "For" and "objective" Lines 140, 141 Suggest period after "al" in Lin et al. (here and elsewhere) Line 186 Suggest changing containing to contains. Line 313 Suggest comma after (Pasyanos et al., 1996) Line 385 Ruptures should be plural. Line 422 "using for?? should this be used for? Line 451 "The subsets of the subset of... is confusing. Is this correct? Please consider rewording. Line 484, 485 Was selected is repeated as selected was This is a confusing sentence -consider rephrasing. Line 498 "study" should be studies Line 501 "and by the distant" should be "and from the distant" Line 579-580 There is no verb in this sentence Line 586 Figures should be singular Line 623 The citation to Table 5.4.4-1 has an extra period "4.-1" Line 654 Function from? Do you mean functional form? Line 695 Insert "and" between "another" and "should" Line 699 A comma is needed after "selected" Line 703 Change rejection to rejecting. or place "of' after rejection Line 703 "ad" should be "and" Line 752 Suggest a comma after is used" Line 754 Suggest set be pluralized Line 777 Suggest a comma after data" Line 787 Change "as" to "at" Chapter 6 GMC Models For the Median Line 16 Delete up" Line 42 Delete the extra ) after T akedatsu, 2015 Line 57 Insert "to" between "leads" and a model" Line 58 Add "because" after **and furthermore." Line 67 Magnitude should be plural Line 71 Add a comma after "50 km) Line 143 Replace "in" with "on" -Based on ... Line 155 Insert "a between "explained as" and "geometric" Line 238 This would read better as " ... Model to account for the HW ... Line 274 Was calculated or were calculated? Line 362 Place a comma after GMPE. Also. magnitudes should be plural. Line 439 Place a comma after (Model B) Line 466 Insert "and" after M>7.5, Line 496 Place a comma after "used" Line 542 HW models" -models should be singular. Line 548 Change applies to applied Line 569 Set off wi with commas Line 594 In is given" should read "It is given" Line 615 "the difference is scaling" -is should be "in" Line 801 Reflects should be singular Lines 802/803 Move "fully" to before "represents Line 830 Example should be plural Line 882 Figures should be lower case Line 892 "These two model" -model should be plural Line 902 Insert "to the between similar and Spudich Line 936 Insert a comma after (20t4) Line 954 Insert "a between "for" and "strike-slip" Line 1019 Insert "a between ruptures of' and splay fault" Line 1029 Insert an "a" between Approximate a" and "Single Fault". Same with next two lines. Chapter 7 GMC Models for the Sigma Line 12 The closing parentheses should not be subcase Line 100 Insert a comma after "used" Line 101 Insert a comma after "data" Line 107 Insert a comma after "used" Line 108 Insert a comma after "residuals" Line 194 Delete the extra "for" near the end of this line. Line 290 Insert "of' between "distances" and "200-300". Also, Section should be lower case. Line 291 Indicated should be indicates Line 301 Insert "a" between "of' and "few" Line 318 "explanation or this trend change "or" to "for" Line 382 with respect of distance" should be "with respect to distance" Line 499 Provide should be plural Line 518 Insert a comma between branches" and "is developed" Chapter 8 Median GMC Models: DCPP Line 36 Suggest a comma after figures" Line 42 Consider changing random to randomly Line 55 Fault should be plural Line 60 "to the five" should be "for the five" Line 86 "DCPP has made .. . should be "DCPP was made" Line 167 model this penalizes" should read "model that penalizes" Line 293 Insert "and" before "as noted" Line 377 Insert a comma after "removed" Lines 395-396 Place a comma after magnitudes and delete the and" before distances Chapter9 Median GMC Models: PVNPP Line 11 Tl Team should read Tl Team's. Also. weighed should be weighted. Line 25 Capture should be plural Line 40 Insert a comma after "considered". Also. (NGAW2-pv.MEov needs an end-parenthesis Line 41 Remove end-parenthesis after Section 5.3.2 Line 82 Insert a comma after "respectively" Line 86 Under laying?? Underlying? Line 119 There is an extra period after "is used" Line 185 Magnitude should be plural Line 182 Insert comma after "Figure 9. 1-2 Line 219 This sentence would read better if "and that" was replaced by "whereas'" Line 226 "right and side"?? You mean right hand side, correct? Line 254 "is referred to as "influence diagram" -insert "an after "as" Line 278 Insert "to" after "respect" Line 356 Remove the comma after "Section 5. 1.5.2" -it is not needed. Also, "(M6.5 for each ... " Each what? Lines 412-416 Break this into 2 sentences. Start the 2"" sentence at 'Therefore, ... ** Line 424 Sentence ends with a comma. Chapter 10 Tau Model Logic Trees Line 4 Sectrion should be Section. Line 7 Insert "a" between "develop" and "single" Line 34 Insert "that" after "2014 )" Chapter 11 Phi Model Logic Tree: DCPP Line 23 Place a comma after Taiwan. Line 53 Place a comma after "Appendix R Line 59 Place a comma after "respectively" Line 79 Delete "a" between "as" and "heavy-tailed" Line 127 Insert a space after phi Line 132 Delete "the" between "because and "most" Chapter 12 Phi Model Logic Tree: PVNPP Line 10 Insert comma after PVNGS Line 12 There should be the. Plus insert "are" after "the" Line 13 Need a) at the end of the sentence. Line 28 Delete the extra space before the period. Line 29 Insert "which are" after "events" Line 30 Toe should be to. Line 46 Number should be plural Line 50 Time should be plural Line 52 Insert "the" before Tl Team Line 72 Insert a comma after "respectively" Line 102 "dataset contains should read "datasets contain". Also, insert a comma after "records" Line 123 Magnitudes should be singular Line 132 Insert a comma after "respectively" Line 137 Insert a comma after "respectively" Chapter 13 Total Sigma Model Line 32 Approached should be approaches Line 39 Represent should be plural Line 42 Insert a space between "the" and "greater Line 52 Change the period to a comma after Appendix P Line 54 scaled" is repeated -delete one. Line 74 One to one -correct the zero to a lower case o Line 76 Point should be plural Line 82 "uses" should be "used". Also. "numerical" should be "numerically" Line 109 "Greater Arizona source" -source should be plural. Line 125 Insert "as to after "designated" Line 132 Delete "for" between "of the" and "single" Line 135 indicated" should be "indicate". Also, insert "with" between that" and "the Line 176 Insert "affects" after "path" Line 182 The title should read "Implementation of the Mixture Model Chapter 14 Hazard Sensitivity Line 15 Insert comma after "plant sites" Line 164 Insert comma after "several nodes" Line 351 "show should be plural Line 403 Change "that" to than Line 461 Insert a comma after "approach" Line 473 Delete "in" (presented in with the next case) Chapter 15 Application Guidelines and Limitations Line 34 "then" should be "the" Line 45 Insert "a" between "at" and distance" Line 56 Available" is misspelled. constraint" should be constrain". Line 57 "comprising is misspelled Section 6.5 Are Eq. 6.5-8 and Eq. 6.5-18 identical? If so, please remove Eq 6.5-18 and associated text. The same comment applies to 6.5-9 and 6.5-19, 6.5-10 and 6.5-20. Lines 1164 and 1165, variable clcHANGE was not defined. Line 2051, please explain which sigma is plotted in Figure 6.5.1-3. Is it fo1R_s1G_ss (Eq 6.5-10) or cro1R_ss? Line 1197 to Line 1199, please clarify if the inputs the Tl Team used to produce Figure 6.5.1-3 are meant to represent the dominant scenarios for DCPP and PVNGS? Which of the two Rys is representative of DCPP? November 3, 2012 Carola Di Alessandro, Ph.D. Project Manager for the SWUS GMC SSHAC GeoPentech, Inc. 525 N. Cabrillo Park Drive, Suite 280 Santa Ana, CA 9270 I

Dear Dr. Di Alessandro:

The Participatory Peer Review Panel (PPRP) has reviewed the Project Plan (dated October 3, 2012) for the Southwestern U.S. Ground Motion Characterization (SWUS-GMC) SSHAC Level 3 study. The Project Plan document is well prepared, explains the SSHAC Level 3 guidelines well, and provides a framework for successful implementation of those guidelines. The Plan calls for an additional member, not yet named, to be appointed to the Technical Integration (TI) team to provide expertise in numerical ground motion simulation. That appointee should be knowledgeable with respect to the techniques employed in such studies, as well as knowledgeable in the appropriate selection of model parameters for those studies. We look forward to seeing that position filled by an experienced scientist or engineer with a well-established professional or academic reputation, so that this appointment will also bring the TI team an appropriate balance between experienced experts and more junior members. The PPRP requests that some clarifying language be added to the plan, as noted in an attachment to this letter. The panel believes that, with these clarifications, together with the augmentation of the TI team described above, the Project Plan has the elements required for meeting the SSHAC Level 3 objectives. We thank the project team for its efforts in developing the plan and look forward to its implementation. Sincerely, Steven M. Day Chair, PPRP Brian Chiou Member, PPRP Kenneth Campbell Member, PPRP Thomas Rockwell Member, PPRP

Attachment:

Requested clarifications and edits Attachment to PPRP letter of November 3, 2012 Requested clarifications to SWUS GMC Project Plan 1. It still does not appear to us that the project plan spells out clearly that comparison tests will be m<1de of the different h<1zard codes used by the three utilities, as discussed in our initial review1, <1nd we request that this be addressed. 2. The Project Pl<1n stipulates that the PPRP will meet for a half day after Workshops 1 <1nd 2, and we reaffirm our requestz for a modification of the language to note that the PPRP will have the flexibility to complete its post-workshop deliberations by teleconference and/or email. We feel that occasionally, due to scheduling or personal difficulties, those other arrangements may be the optimal way to insure full participation of the panel. 3. The project pl<1n notes that documentation of the numerical simul<1tion methods will be part of the project database, but does not address our concern that the documentation be available to the PPRP in advance of the time when the models are evaluated3. For models like these being developed via university research, it is reasonable to be concerned that insufficient documentation may be available at the time of model evaluation. Hence, it is important that the Project Plan be clear about the documentation ground rules and the consequences of insufficient documentation. Minor editorial notes (i) Page 18, row 5 (Compile Regional GM data for Arizona): Although this work has been discussed during the working meetings and it is clearly important, it was not mentioned in the main text of the Project Plan, so we suggest removing it from Figure 2 or adding some discussion to the Project Plan. (ii) It would be helpful to have the TI Te<1m briefly describe how the simulated dat<1 will be used in the GMC study, in particular in the construction of the logic tree (e.g., will there be branches based on the simulation results?). (iii) Page 12, 2nd paragraph --typo 'Wworkshop' (iv) P<1ge 12, 7th bullet --'as distances' should be 'at distances' 1 PPRP review memo dated 9 /17 /2012, see Note 4 2 Ibid, Note 10 Note 2 From: Carola DiAlessandro Sent: Monday, July 28, 2014 10:23 AM To: Steven Day; ken.w.campbell@comcast.net; brian_chiou@comcast.net; Tom Rockwell Cc: norman abrahamson; Katie Wooddell; Douglas Dreger; Bob.Youngs@amec.com; Linda Al Atik; Nicolas Kuehn; Jennie Watson-Lamprey; Nick Gregor; Melanie Walling; Gabriel Toro; mcguire@lettisci.com; John Barneich

Subject:

Follow up after PPRP Briefing: please provide your feedback at your convenience

Dear Steve and PPRP Colleagues,

We would like to follow up with you after the concluded PPRP Briefing held on July 17 and 18 @ UC Berkeley. We have not received any further feedback from you so far, besides for the verbal comments received during the meeting and summarized in the notes shared with you soon after the event (https ://www .dropbox.com/s/ .... omlssis ... ./Jul 17-18 PPRP notes.pptx) As a reminder, the notes and the presentations were collected under the DropBox link https://www .dropbox.com/ .... omissis .... / , which is in turn accessible from the PPRP Transmittal Folder at https://www.dropbox.com/. ... omissis ... ./ Please let us know as soon as possible if those notes are comprehensive, and if you have any further feedback on the presentation material and/or on the Preliminary Draft Report. We are revising the GMPE selection approach via visualization and addressing other concerns as emerged during the discussions. We also look forward to revising the Draft Report to encompass the changes in the GMC model while capturing your requests, so please provide your feedback at your earliest convenience. Should you have any question or concern, do not hesitate to contact us. With best regards, Carola Di Alessa11dro, Ph.D. Project Manager.for the SWUS GMC SSHAC GcoPcntcch, Inc. 525 N. Cabrillo Park Drive. Suite 280 Santa Ana. CA 92701 Mobile: 510-491-6713 Fax: 714-796-9191 Office Phone: 714-796-9100 Email: carola dialessandro(a;geopentech.com February 23, 2015 Steven M. Day Chair, Participatory Peer Review Panel Department of Geological Sciences San Diego State University 5500 Campanile Drive San Diego, California 92182

Dear Prof. Day:

The Tl Team and PM appreciated the valuable comments and suggestions received from the Participatory Peer Review Panel (PPRP) during the report preparation. This communication serves to provide the PPRP with updates on the Tl Team and PM replies to the Comments included in the Participatory Peer Review Panel Letter No. 3: Draft Rev.1 Report, Southwest United States Ground Motion Characterization Level 3 SSHAC Project, dated Feb. 20, 2015. Each of the Tier 1 Comment is addressed in detail by means of a Tl Team-PM reply, and by providing an excerpt of the report where the edits were incorporated. We are aware of a documentation limitation associated to the directivity model which we expect being included in the planned PPRP Closure Letter. We are already preparing a response to address such limitation, to be incorporated in the Rev.1 Report publication (Feb. 26, 2015). In the case of the Tier 2 Comments, the provided format of the Comment Response Table was used to fill the column entitled "Summary of Revisions to Report". We want to clarify that the edits associated to the Tier 2 Comments are still ongoing, and we expect to address the majority for the Rev.1 Report publication. There are however some comments that will remain not addressed for paucity of time. For clarification, the open items not yet addressed are associated to all three installments received from the PPRP. The Tl Team and PM plan to address those left-over comments in the following week, and to issue a Rev.2 Report by March 10, 2015. We'll follow up with the PPRP on a mutually amenable logistic for completing such task. We hope you will find this document useful for resolving the Tier 1 Comments, and for evaluating the Tl Team's progress on addressing the Tier 2 Comments. Sincerely, --Carola Di Alessandro (also in behalf of the Tl Team) TIER 1 COMMENTS Comment Number 1033 -Directivity Model: General PPRP Comment: The Tl team has not provided sufficient information detailing their evaluation of the directivity model. It is necessary that the explanation of the Tl Team's evaluation include sufficient detail to clarify (1) what the model is, (2) what its limitations are, and (3) what analysis was done to demonstrate that it is justifiable (in light of any model limitations) to use it for the purpose it is being used for here. Please provide an explanation meeting those criteria in the report. Tl TEAM -PM Reply: 1) The text in section 6.5 was revised to fully describe the Watson-Lamprey directivity model. The equations and coefficients describing the model, currently included in the DCPP HID (Appendix C -Part II), were included in the main report. (2) The text in section 6.5 was expanded to describe the limitations that we see with the Watson-Lamprey directivity model: (i) it is only for straight faults, (ii) it applies the CY14 directivity to other GMPEs, (iii) it uses the changes to the standard deviation in the CY14 model to scale the standard deviations from the other GMPEs (3) Analyses done to demonstrate that the model is justifiable were added to the text of section 6.5. We included simple checks to show that the results from the model are reasonable in that they are consistent with the range of directivity effects from other directivity models. The PPRP has provided feedback that such simple checks are inadequate, but the Tl team's judgment is that, given the small effect on the hazard at DCPP (less than 2%), using simple checks is justified because even if the Watson-Lamprey model is off by a factor of 2, there would still be only a small effect on the hazard (less than 4%). This conclusion that the directivity effect on the DCPP hazard is small is based on using the Watson-Lamprey model to do the hazard runs. So if the Watson-Lamprey model is wrong, it is not a valid check. Our simple checks provide us confidence that the Walson-Lamprey model is reasonable for the cases that control the hazard at DCPP. An alternative would be to run a full comparison of the hazard run with the CY14 methodology for directivity; however, we do not expect to be able to complete this comparison by Feb. 23, 2015, as requested. A place-holder has been inserted in the text to accommodate the discussion on the comparison, if time allows. We recognize this will remain as a limitation of the Tl Team model, but due to the small effect of directivity on the hazard at DCPP, the Tl Team judged that this limitation is mainly of scientific interest and not a significant issue for the hazard for DCPP or PVNGS. Because (1) the Watson-Lamprey model is still under review a PEER and (2) the effect on the hazard at DCPP is small, (3) questions about the applicability of the CY14 centering and directivity models to other GMPEs, and (4) large increase in hazard run times with little expected effect if the CY 14 directivity model is implemented in the hazard integral, the Tl Team judged that it would be better to remove the directivity model from the DCPP model. Comment Number 1034-Directivity Model: Chapter 6, Lines 914-922 PPRP Comment: There are two major assumptions that are made in applying the CY14 centered directivity model to the GMPEs used in the DCPP GMC model: (1) that the large-magnitude distribution is similar amongst the NGA-West2 GMPEs so that similar directivity effects can be expected, and (2) that the centered CY14 model can be applied to the NGA-West2 GMPEs to model these effects. These are both potentially important assumptions. Please provide justification for these assumptions or indicate that the impact of these assumptions is not critical to the hazard. Tl TEAM -PM Reply: Based on the CY14 centered model and using the Watson-Lamprey simplified model, the directivity effect on the hazard is small (2% or less) as shown by sensitivity analyses documented in Chapter 14. Considering the similarities of the large-magnitude short-distance data used by the various modelers, the Tl Team's judgment is that the directivity effects will not become significant to hazard if separate centering models were developed for each GMPEs. PEER plans to develop GMPEs including directivity effects that are centered for each individual GMPE. This work is currently scheduled to be completed in 2017. It is beyond the scope of SWUS to develop these models. Comment Number 1035-Directivity Model: Chapter 9, Lines 317-320 PPRP Comment: Please further justify the zero weight given to the directivity adjustment branch by providing evaluations in support of the claim that directivity effects are adequately captured by the standard deviation from the GMPEs. Also, if this claim is justifiable, please explain why the same justification was not applied to DCPP to assign a zero weight to its directivity branch. Tl TEAM -PM Reply: The text of Section 6.5 (not Chapter 9) was revised to include the discussion outlined below. The standard deviation of GMPEs is due to the simplification of the source, path, and site effects. (We use the single-station sigma approach which removes the simplification for site effects, so all that remains is the source and path) A key assumption in using the single-station standard deviation from empirical GMPEs for hazard calculations is that the data used to develop the GMPEs are a representative range of other aspects of the source and path that are not captured in the simple parameters used in the GMPEs. This would include the location of the hypocenter (e.g. directivity), slip distribution, rupture velocity, rise time (or complete slip time function), and 3-D crustal path effects. Directivity is just one of the parameters that is assumed to be representatively sampled in the empirical data. In magnitude-distance ranges for which there are large numbers of recordings, forward, neutral and backward directivity conditions are all sampled. We assume that the sampled distribution is representative of the distribution of future earthquakes. In magnitude-distance ranges for which there are fewer data (e.g large magnitudes at short distance), it is less likely that the distribution of directivity effects in available empirical data set is representative of the distribution of directivity effects for a future earthquake at a specific site. For this reason, we used the Watson-Lamprey simplified model to check this for DCPP, which has nearby faults. The hazard results showed for that for DCPP site, the impact of using the distribution of directivity effects based on the CY14 parameterization (as simplified by Watson-Lamprey), was almost the same (less than 2% difference) as using the distribution in the data used by the GMPEs. For directivity, we will add a plot that shows the distribution of the IDP directivity parameter in the NGA-West2 data set for various magnitude and distance ranges. As stated in response to comment 1033, the Tl team decided to change the logic tree for DCPP to put full weight on the no directivity branch. This will avoid the inconsistency in the application of directivity between DCPP and PVNGS. Excerpt of Chapter 61 Section 6.5 and associated figures/tables follows in the following pages. Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 956 of ground-motion predictions for different two different magnitudes and distances, and calculating their 957 ratios. 958 Figure 6.4.5-15 and Figure 6.4.5-16 show an el(ample of the epistemic uncertainty in distance and 959 magnitude scaling, respectively, for PVNGS (Model A), normal style of faulting, for T" 0.01 sec. Figure 960 6.4.5-15 shows the PSA ratio histogram for distance scaling for a M6 scenario. Figure 6.4.5-16 shows the 961 PSA ratio histogram for magnitude scaling for a Rx distance of -15 km. These figures show that the range 962 of magnitude and distance scaling in the selected models is broader than the range of the candidate 963 GMPEs. 964 Appendix H includes several plots showing epistemic uncertainty in distance and magnitude scaling for 965 various periods for DCPP and PVNGS, respectively, in Sections 2.1.11, 2.1.12, 3.1.11, 3.1.12, 4.1.11 and 966 4.1.12. 967 968 6.5 Directivity Scaling Models 969 6.5.1 Candidate Models for Directivity Scaling 970 The most widely used models for incorporating directivity effects into ground motions are the 971 Somerville et al. (1997) model and Abrahamson (2000) modification to this model. These two models 972 parameterize the directivity effect for strike-slip faults using X cos(theta) as the predictive parameter, 973 where X=s/L is the ratio of the rupture length between the epicenter and the site (s), to the total rupture 974 length (L), and theta is the azimuth between the fault strike and the site azimuth from the epicenter. 975 In 2008, updated directivity models were developed as part of the PEER NGA-Westl ground motion 976 study. The el(panded empirical data sets and numerical simulations for directivity from the 2008 studies 977 showed that the directivity effect depends on the length sand not the normalized length X (Spudich and 978 Chiou (2008). As an example comparison of using normalized versus un-normalized rupture lengths for a 979 MS earthquake, the directivity from the Spudich and Chiou (2008) directivity model is compared to the 980 Abrahamson (2000) directivity model for T"3 seconds in Figure 6.5.1-1. The directivity effects from the 981 Abrahamson (2000) model are similar to the Spudich and Chiou (2008) for the 100 km rupture length for 982 X Cos(theta)>0.2. The Abrahamson (2000) model was based on numerical simulations for M7.5 strike-983 slip earthquakes. This figure shows that for longer or shorter rupture lengths, the older model based on 984 the normalized rupture lengths is not similar to the Spudich and Chiou (2008) model. 985 In addition to the effect of using un-normalized rupture lengths, Figure 6.5.1-1 also highlights the issue 986 of centering of the directivity. For MS, the Spudich and Chiou (2008) directivity model leads to positive 987 directivity effects for almost all rupture locations (all values of X cos(theta)); however, the GMPE models Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-31 Comment [alext74): 0479 "Comment [CDA175): 480 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 988 are developed to have near zero mean residual for large magnitudes. This indicates that the 2008 989 directivity models are not directly applicable to the GMPEs without centering the directivity model. 990 Chiou and Youngs (2014) addressed the issue of centering the directivity model by considering the 991 sampling of the directivity for stations in the empirical data set compared to the distribution of 992 993 994 995 996 directivity parameters for randomly located stations. In-depth discussions on the issue of centering can be also found in Spudich et al. (2014) and in Spudich and Chiou (2013). Because the candidate GMPEs tend to fit the same limited large magnitude data, the centering of the directivity model for the Chiou and Youngs (2014) dataset can be assumed to also represent the centering for the other NGA-West2 candidate GMPEs. For the non-NGA-West2 GMPEs used at DCPP (ASB14, ZH06 and ZLll), there are no 997 available evaluations of the centering of the datasets for directivity parameters. The Tl Team judged that 998 directivity effects should be considered in all the models, for application to DCPP, given the short 999 distances and large magnitudes of the controlling events; therefore, the Tl Team models apply the Chiou 1000 and Youngs (2014) directivity centering to all the common-form models even though they were 1001 developed from a combination of NGA-West2 and non-NGA-West2 proponent models. 1002 The key outcome of using this directivity model is that, for sites at the same closest distance, the median 1003 of the ground motion will vary for different locations along strike. That is, the GMPEs do not fully 1004 capture the scaling of the ground motion for sites located along the rupture (different directivity). 1005 Depending on the rupture and the site location, the directivity effect may increase or decrease the 1006 ground motion. Randomizing over the hypocenter location for the directivity implies variability in the 1007 median ground motions, which impacts the standard deviation. 1008 To simplify the application of the directivity model, Watson-Lamprey (2015) developed scale factors that 1009 describe the change in the median and total standard deviation as a function of the position along strike 1010 (Rv) and the distance perpendicular to the strike of the rupture (R,). The Chiou and Youngs (2014) 1011 directivity model could be used. but randomizing over the hypocenter would increase the hazard 1012 calculation time, while the Watson-Lamprey's models, which pre-calculated the effect of hypocenter 1013 randomization, expedites the calculation. In the Watson-Lamprey (2015) approach, the location of the 1014 hypocenter was randomized along the rupture, and the median and variability for the range of 1015 hypocenter locations was computed using the directivity effect predicted by Chiou and Youngs (2014), 1016 which is based on the directivity parameter OPP described in Chiou and Spudich (2013). The standard 1017 deviation reflects the variability of the random hypocenter on the rupture plane. This simplified model is 1018 applicable to both strike slip and dip slip earthquakes. 1019 A simplified method for directivity effects is described in Attachment C. and summarized in the following 1020 section. The equations for the preferred directivity model are also provided in the following section. 1021 6.5.l.l Watson-Lamprey (2015) Directivity Effects Model Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-32 .. Comment [CDA176): 481 .. Comment [CDA177): 482 .. Comment [CDA178]: 483 Comment [CDA179): 484 Comment [CDA180]: 478 ,. .. Comment [CDA181): 48& Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 1022 The Watson-Lamprey (2014) simplified implementation of directivity is documented in a PEER draft 1023 report that will be published in 2015. The basic steps followed by Watson-Lamprey {2015) do develop 1024 her model are described here. First, a suite of rupture geometries for strike-slip ruptures up to a 1025 moment magnitude of 8 and reverse ruptures up to a moment magnitude of 7.5 was created. Next, the 1026 mean and standard deviation of the change in the 5% damped pseudo-spectral acceleration at sites due 1027 to directivity by randomizing over hypocenters was calculated for a suite of sites out to a rupture 1028 distance of 70 km. The hypocenter randomization model for strike-slip ruptures was from Chiou and 1029 Youngs (2008b). For reverse ruptures, a new hypocenter distribution model was developed based on the 1030 hypocenters from large magnitude reverse events world-wide (see Attachment C, Section 4). 1031 Using the set of computed directivity factors, the mean and standard deviation of the change in the 5%-1032 damped pseudo-spectral acceleration was used to develop models for both strike-slip and reverse 1033 ruptures. The resulting factors for the median and standard deviation were fit to simple parametric 1034 models: for strike-slip earthquakes, the model parameters are rupture length, Rx and R,; for reverse 1035 earthquakes, the model parameters are rupture width, rupture length, dip, Rx and R,. Figure 6.5.1-2 1036 shows a schematic representation of the parameters utilized by the directivity model. 1037 An example of the scaling for a strike-slip fault with 80 km rupture length (M7) and a site located at an 1038 Rx value of 3 km is shown in Figure 6.5.1-3. For a site located at the center of the rupture {Rv=O), the 1039 median is slightly reduced and the additional variance term is slightly increased. For a site located at the 1040 end of the rupture (R,=40 km) both the median and variance are increased. This shows that the 1041 1042 1043 1044 1045 directivity effects will be strongest for sites located at the ends of large strike-slip ruptures in the case of treating the hypocenter position as random along the rupture. Attachment C has additional example cases. The functional form of the directivity adjustment for strike-slip earthquakes is given by: J;>IR_ss(M ,R111,,,R,,R,, l)= Factor,s(A1 ,R,,11.,R,,R,, *(M -c.,(T) y) xc. ,.,,,,..(T)T/)/I( R(RR/'P)T/)11< .\f(M) 1046 (Eq. 6.5-1) 1047 and the functional form for reverse earthquakes is given by: 1048 fmn_*i (114.RR{P*R,.R,.,W.l,Dip)= Factor.1.(.A.1,R111,.,R,.R., .. *(M -c.1,(T))') X Cg_rurw(T)T,)JR_l<(Rnr:P )T/)11<_.11 (M) 1049 (Eq. 6.5-2) 1050 where Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-33 Comment [CDA182]: 488 .. Comment [CDA183): 489 1051 1052 1053 1054 1055 1056 . (max(M-5.5,0) T01R .lf(M)= mml O.S ,l) Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 {Eq. 6.5-3) {Eq. 6.5-4) ,RRLr*R,,R,.L) = a0 +a1 (max( RyRatio *cos28,-0.5) )+ a2 (max ( J(vRatio

• cos20, -0.5) r + a_1 (max (Ry Ratio"' cos20, -0.5) r (Eq. 6.5-5) ----2 --1 --Fac:torw,(M .RRur* Rx, R,.W,L,Dip) = b0 +b1 cos2tP + b2cos2tP + bJcos2tP + b4cos28+ --2 ' b5cos20 + + b7RyRatio + (Eq. 6.5*6) Ri*Ra1io = min(fl.1) . l/2 {Eq. 6.5*7) 1057 For strike-slip sources, cos20 is the average value of ws20 evaluated over the length of the surface 1058 projection of the top of rupture and where (}is the angle between the ray from a point on the surface 1059 of rupture to the site and the ray from the same point along strike. This is calculated using the following 1060 equation: ( [R. + L/2)) __ R,.+Ll2-2IRxl*ArcTange/1f 'IR,I cos20 = * -L 1061 ( I I ( R. + U 2 )J R,. -LI 2-2 R, "'ArcTangent 'IR,I (Eq. 6.5-8) L 1062 For reverse sources, cos2¢' is the average value of cos2; evaluated in the plane perpendicular to 1063 rupture over the width of the rupture and where ,P is the angle between the ray from a point on the Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-34 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 1064 rupture to the site and the ray from the same point up dip. This is calculated using the following 106S equation: lr H .. + U 2 -2IH, cos( l)ip )I"' Arcfo11ge111( I H,. +. (U 2 ll )) __ , R., cos Dip cos2<1> = 1066 I. {Eq. 6.5-9) ( R, -LI 2-21Rxcos(Dip)I* )1)) L 1067 For reverse sources, cos2() is the average value of cos20 evaluated over the length of the surface 1068 projection of the top of rupture and where (}is the angle between the ray from a point on the surface 1069 of rupture to the site and the ray from the same point along strike. This is calculated using the following 1070 equation: r/C + l !2-2IR,sin(Dip)I* ArcTangem(1 R .. _+ __ R,sm Dip cos20 = l {Eq. 6.5*10) 1071 lt ( R, + U2 l) R:. -I. ! 2 -21 R., (Dip )I* A re Tange/11 IR., (Dip ll J I. 1072 The coefficients for the directivity effects for the median ground motion are listed in Table 6.5*1. 1073 1074 Table 6.5-1: Coefficients for directivity effect adjustments to the media for SS and REV earthquakes. Median for SS earthquakes Median for REV earthquakes Period* Period-Dependent Period* Period-Dependent Independent Coefficients Independent Coefficients Coefficients Coefficients ao *0.078101 Period (sec) Cs Csb bo *0.13414 Period {sec) Cs ratio Csb a1 *0.033923 O.ot 0.000 0.483 b1 0.022371 0,01 0.000 0.483 a2 0.20067 0.02 0.000 1.214 b2 0.047363 0.02 0.000 1.214 a1 0.149361 0.03 0.000 1.642 b1 0.02078 0.03 0.000 1.642 a"' -0.3004 0.05 0.000 2.181 b. 0.1042 0.05 0.000 2.181 0.075 0.000 2.609 bs 0.00716 O.D75 0.000 2.609 ---------*--*--0.1 0.000 2.912 b6 *0.1239 0.1 0.000 2.912 Chapter 6: GMC Models for the Median: Overview and Methodology Page 6*35 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 0.15 0.000 3.340 b1 0.069512 0.15 o.ooo 3.340 I 0.2 0.000 3.643 ba 0.076094 0.2 0.000 3.643 0.25 0.000 3.879 b .. -0.26717 0.25 0.000 3.879 0.3 0.000 4.071 0.3 0.000 4.071 0.4 0.000 4.375 0.4 0.000 4.375 0.5 0.460 4.610 0.5 0.460 4.610 ------*--*--0.75 0.920 5.038 0.75 0.920 5.038 1 1.000 5.341 1 1.000 5.341 1.5 1.000 5.769 1.5 1.000 5.769 2 1.000 6.072 2 1.000 6.072 3 1.000 6.500 3 1.000 6.500 4 1.000 6.804 4 1.000 6.804 5 1.000 7.039 5 1.000 7.039 7.5 1.000 7.467 7.5 1.000 7.467 10 1.000 7.770 10 1.000 7.770 The functional form of the directivity sigma adjustment for strike-slip earthquakes is given by: ,Rm., Rx, R,..L)-= Factor,,,\(M ,Rm., Rx, *(\rt -c.,,(T) Y) x )T,,,R_JJ (M) and the functional form for reverse earthquakes is given by: {Eq. 6.5-11) .1;>11, $/(; Rr(M, R/Ul"R" R_, .W,1., Dip)= Factorl,,.(M, R/U/>>R,, R_, .w, /.,Dip)cxpel" *(M -c\,(T) :Y) x c"-""'"(T)T,,,,,_"(Rm. )T,,,,,_ 1.1 (M) {Eq. 6.5-12) where {Eq. 6.5-13) . (max(M-5.5,0) l TmR_ii(M)= mml 0.8 ,lj {Eq. 6.5-14) Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-36 I 108S 1086 1087 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 ,R11,,P.Rx,R,,L) = a0 + a1 {max ( RyRatio *cos2{},-0.5)) + a2 (max ( RyRatio
• cos211,-0.5))2 + a1 (max( RyRaiio
• cos28,-0.5) r FactorR,*:I' (.1\1,R/(..,,,R,,R,.,W,L, Dip)= h0 + h1cos2,P + cos2/ + h_icos21/J' + + RvRatio = min(fu.1) . L/2 {Eq. 6.5-15) {Eq. 6.5-16) {Eq. 6.5-17) 1088 For strike-slip sources, ros2() is the average value of cos20 evaluated over the length of the surface 1089 projection of the top of rupture and where (}is the angle between the ray from a point on the surface 1090 of rupture to the site and the ray from the same point along strike. This is calculated using the following 1091 equation: __ (R, +Li 2-21Rxl
• ArcTangefll( cos20 = * -L 1092 ( I I ( R. + U 2 )) R,. -LI 2 -2 R,
• ArcTa11gent 'IR,I {Eq. 6.5-18) L 1093 1094 For reverse sources, cos2¢> is the average value of cos2; evaluated in the plane perpendicular to 1095 rupture over the width of the rupture and where ,P is the angle between the ray from a point on the 1096 rupture to the site and the ray from the same point up dip. This is calculated using the following 1097 equation: Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-37 1098 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 ( . I ( . )I ( R, +L/2 )) R, +Li 2-2 R, cos Dip
• ArcTnngent I * ( . )I __ . R, cos /)ip cos2ct> = L {Eq. 6.5-19) (R, -li2-2IR, cos(Dip)I* R, )1)J Rxcos Dip L 1099 For Reverse sources, cos20 is the average value of ws20 evaluated over the length of the surface 1100 projection of the top of rupture and where 0 is the angle between the ray from a point on the surface 1101 of rupture to the site and the ray from the same point along strike. This is calculated using the following 1102 equation: 1103 1104 1105 1106 1107 l( R., + l i 2-21R, sin (Dip )I* ArcTm1ge11/ r I R, )1)) __ * \ R,sm(D1p cos2(} = l ( R .. -li2-2IR, sin(Dip)I .. An:Tu11ge111(1 R, _+(l/.21)1 I\ R, sm Dip) , l {Eq. 6.5-20) {Eq. 6.5-21) {Eq. 6.5-22) 1108 The coefficients for the directivity effects for the sigma are listed in Table 6.5-2 (a and b). 1109 1110 1111 Table 6.5-2a: Coefficients for Directivity Adjustment Model for the Sigma Sigma for SS earthquakes Sigma for REV earthquakes Period-Period-Dependent Period-Period-Dependent Independent Coefficients Independent Coefficients Coefficients Coefficients Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-38 1112 ao 0.029001 Period (sec) Cs r,;itio 31 0.21112 O.ot 0.000 0.483 a, 0.53116 0.02 0.000 1.214 a3 -0.60145 0.03 0.000 1.642 aM -0.16960 0.05 0.000 2.181 O.Q75 0.000 2.609 -----0.1 0.000 2.912 0.15 0.000 3.340 0.2 0.000 3.643 0.25 0.000 3.879 0.3 0.000 4.071 0.4 0.000 4.375 0.5 0.460 4.610 0.75 0.920 5.038 1 1.000 5.341 1.5 1.000 5.769 2 1.000 6.072 3 1.000 6.500 4 1.000 6.804 5 1.000 7.039 7.5 1.000 7.467 10 1.000 7.770 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 bo 0.044478 Period (sec) Csrot;o b1 -0.021982 O.Ql 0.000 0.483 b, -0.025129 0.02 0.000 1.214 b3 0.020343 0.03 0.000 1.642 b. -0.022130 0.05 0.000 2.181 bs 0.030626 0.075 0.000 2.609 ---*--*--bM 0 0.1 0.000 2.912 0.15 0.000 3.340 0.2 0.000 3.643 0.25 0.000 3.879 0.3 0.000 4.071 0.4 0.000 4.375 I 0.5 0.460 4.610 0.75 0.920 5.038 1 1.000 5.341 1.5 1.000 5.769 2 1.000 6.072 3 1.000 6.500 4 1.000 6.804 5 1.000 7.039 7.5 1.000 7.467 10 1.000 7.770 Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-39 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 1113 Table 6.5-Zb: Coefficients for Directivity Adjustment Model for the Sigma Period (sec) ()C/1.1.\Wi 0.0. 2.0 0 3 0.1205 4 0.1535 5 0.1913 -*--7.5 0.2285 10 0.2478 1114 *Comment [CDA184]: 1033part1 1115 6.5.2 Tl Team's Evaluation of Directivity Scaling Models 1116 The Tl Team evaluated the simplified approach to directivity described in Section 6.5.1.1 and the 1117 evaluations are summarized below. 1118 The advantage of the Watson-Lamprey (2015) model is that it evaluates the net effect of variability in 1119 hypocenters on the directivity parameter rather than requiring a direct integration over hypocenter 1120 location for the hazard calculation. It has also estimates the impact on the standard deviation of other 1121 GMPEs in addition to the CY14 model. The model represents in average effects of directivity over the 1122 four NGA-West2 models. 1123 Limitations of the Watson-Lamprey (2015) model are that: 1124 1. It is only for straight faults; 1125 2. It applies the CY14 directivity to other GMPEs; 1126 3. It uses the changes to the standard deviation in the CY14 model to scale the standard 1127 1128 1129 deviations from the other GMPEs, and 4. The review of the Watson-Lamprey (2015) model for publication as PEER report is not complete and the model in still draft. 1130 There are two major assumptions that are made in applying the CY14 centered directivity model to the 1131 GMPEs used in the DCPP GMC model: (1) that the large-magnitude distribution is similar amongst the 1132 NGA-West2 GMPEs so that similar directivity effects can be expected, and (2) that the centered CY14 1133 model can be applied to the NGA-West2 GMPEs to model these effects. Considering the similarities of 1134 the large-magnitude short-distance data used by the various modelers, the Tl Team's judgment is that 1135 the directivity effects will not become significant to hazard if separate centering models were developed 1136 for each GMPEs. PEER plans to develop GMPEs including directivity effects which are centered for each Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-40 *Comment [CDA185]: 486 Comment [CDA186): 1033 patt 2 1137 1138 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 individual GMPE. This work is currently scheduled to be completed in 2017. It is beyond the scope of SWUS to develop these models. 1139 Because the Watson-Lamprey model is still in a draft report, the Tl team conducted simple checks to 1140 show that the results from the recommended model are reasonable in that they are consistent with the 1141 range of directivity effects from other directivity models, such as those shown in Figure 6.5.1-1. Because 1142 the long-period hazard at DCPP is controlled by the Hosgri fault (Section 4.1.4), the main concern for 1143 application of the directivity models is for strike-slip earthquakes. The DCPP site is not located up-dip 1144 from the Los Osos fault, so directivity effects from the dip-slip Los Osos fault would not be large. 1145 Figure 6.5.1-3 shows the Watson-Lamprey model for M7 earthquakes with an 80 km rupture on a strike-1146 slip fault for two sites at an Rx distance of 3 km: a site located at the end of the rupture (Rv=40) and a 1147 site located at the center of the rupture (R,=O). At a period of 3 seconds, the median directivity term for 1148 a site located at the end of the rupture is 0.18 (or a factor 1.2). At the center of the rupture, the 1149 directivity factor is -0.07 (factor of 0.93). Using the previous directivity models shown in Figure 6.5.1-1. 1150 for a 100 km long fault, the Spudich and Chiou (2008) model has a maximum directivity factor for T=3 1151 sec of 1.5 and a minimum factor of 0.9. If the Spudich and Chiou (2008) model was centered so that 1152 the mean factor was about 1.0, then the range would be about 0.7 to 1.3. 1153 The Spudich and Chiou (2008) model is for a specified hypocenter location, while the Watson-Lamprey 1154 model is the average for a randomized hypocenter. The average directivity factor of 1.2 from the 1155 Watson-Lamprey model for sites located at the end of the rupture is in the upper range of the Spudich 1156 and Chiou model. At the center of the rupture, the Watson-Lamprey model has an average directivity 1157 factor of 0.93, which is consistent with sites near the center of the rupture having slightly below average 1158 because the ruptures will, on average, be away from the center. The standard deviation of the 1159 directivity factor is 0.15 for the site at the end of the rupture. This is consistent with a range of+/- 30 % {+/- 1160 0.28 in In units) if we take the full range to be about+/- 2 standard deviations. 1161 Based on this simple comparison, the Tl Team judged that the directivity scaling in the Watson-Lamprey 1162 simplified implementation are consistent with previous models and are reasonable for application even 1163 though the documentation of the model has not been finalized in a final PEER report. This model has a 1164 1165 1166 large advantage in terms of the required computation time for hazard calculations because the randomization of the hypocenters is done outside of the hazard calculation. The hazard sensitivity results in Section 14.2.1 showed that including or not including the directivity 1167 effect had a small impact on the hazard. 1168 The Tl Team's judgment is that, given the small effect on the hazard at DCPP (less than 2%), using simple 1169 checks is justified because even if the Watson-Lamprey model is off by a factor of 2, there would still be 1170 only a small effect on the hazard (less than 4%). Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-41 .. Comment [CDA187): 1034 Comment [CDA188): 1033 pan 3 Comment [CDA189]: 49Q Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 1171 This conclusion that the directivity effect on the DCPP hazard is small is based on using the Watson-1172 Lamprey model to do the hazard runs. So if the Watson-Lamprey model is wrong, it is not a valid check. 1173 The Tl Team's simple checks provide confidence that the Watson-Lamprey model is reasonable for the 1174 cases that control the hazard at DCPP. 1175 Because (1) the Watson-Lamprey model is still under review a PEER, (2) the effect on the hazard at DCPP 1176 is small, (3) questions about the applicability of the CY14 centering and directivity models to other 1177 GMPEs, and (4) large increase in hazard run times with little expected effect if the CY14 directivity model 1178 is implemented in the hazard integral, the Tl Team judged that it would be better to remove the 1179 directivity model from the DCP P model. 1180 By excluding the directivity adjustment model in the logic trees for both sites has an implicit assumption 1181 that the median directivity effect is zero and the variability of the ground motion due to directivity is 1182 captured by the standard deviation by the GMPEs for the two sites. The basis for this assumption is 1183 discussed below. 1184 The standard deviation of GMPEs is due to the simplification of the source, path, and site effects (the 1185 single-station sigma approach is used which removes the simplification for site effects, so all that 1186 remains is the source and path). A l<ey assumption in using the single-station standard deviation from 1187 empirical GMPEs for hazard calculations is that the data used to develop the GMPEs are a representative 1188 range of other aspects of the source and path that are not captured in the simple parameters used in 1189 the GMPEs. This would include the location of the hypocenter (e.g. directivity), slip distribution, rupture 1190 velocity, rise time (or complete slip time function), and 3-D crustal path effects. Directivity is just one of 1191 the parameters that is assumed to be representatively sampled in the empirical data. 1192 In magnitude-distance ranges for which there are large numbers of recordings, forward, neutral and 1193 backward directivity conditions are all sampled. The Tl Team assumes that the sampled distribution is 1194 representative of the distribution of future earthquakes. 1195 In magnitude-distance ranges for which there are fewer data (e.g. large magnitudes at short distance), it 1196 is less likely that the distribution of directivity effects in available empirical data set is representative of 1197 1198 1199 the distribution of directivity effects for a future earthquake at a specific site. For this reason, the Tl Team used the Watson-Lamprey simplified model to check this for DCPP site, which has nearby faults. The hazard results showed for that for DCPP site, the impact of using the distribution of directivity 1200 effects based on the CY14 parameterization (as simplified by Watson-Lamprey), was almost the same 1201 (less than 2% difference) as using the distribution in the data used by the GMPEs. 1202 1203 1204 Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-42 . Comment [CDA190): 1035 1945 >. ....... *::;: u 2.5 2 0 0.5 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 Somerville et al (1997) Abrahamson (2000) Spudich and Chiou (2008) -400 km rupture Spudich and Chiou (2008) -100 km rupture Spudich and Chiou (2008) -30 km rupture .... . -. . .... .. .. 0 0 0.1 0.2 0.3 0.4 0.5 0.6 X cos(theta) 0.7 0.8 0.9 1946 Figure 6.5.1-1: Comparison of directivity from the normalized rupture length models (Somerville et al., 1947 1997; Abrahamson, 2000) and the un-normalized rupture length model of Spudich and Chiou (2008). 1948 1949 1950 1951 1952 Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-123 a) Plan view *Rx +Rx Length Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 bJ Cross sec11on 1953 ----1954 1955 Figure 6.5.1*2; Parameters for the directivity models. 1956 1957 1958 1959 1960 1961 -0.2 en -'E ::J 0. 1 5 +-----I c:: -Ay=O. M7 (med_fac) Ay=O. M7 (sigma_fac} Ay=40, M7 (med_fac) Ay=40, M7 (sigma_fac) E ... 0.05-+--------------+*+--------< >. -*::; :;:::: (,) 0 -0.05 -0.1 0.01 0.1 .......... 1 10 Period (sec) Figure 6.5.1-3: Example of the directivity model scaling for an 80 km long strike*slip fault and a site located at Rx" 3 km. The effects on median ground motion and sigma are shown for two sites located at the center of the rupture (R," O km) and at the end of the rupture (R," 40 km). Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-124 Comment Number 1036 -Evaluation of Common-form suite: Chapter 8, Lines 305-308 PPRP Comment: Please revise this passage to emphasize that these simplified hazard comparisons are not the primary basis for evaluating the common-form suite of representative models (which, though it should be hazard informed, should not be hazard calibrated, i.e., it is required to cover the CBR of the TDI of ground motion, not hazard). It appears that the simplified hazard comparisons are actually being used as a final check to ensure that occasional small excursions of the candidate GMPE estimates (with added epistemic uncertainty) do no carry unexpectedly high leverage with respect to hazard. If that is the case, please reframe the discussion to clarify that. The additional discussion should emphasize this point by summarizing the non-hazard-based justification for accepting a suite of common-form models that does not fully envelop the predictions of the candidate GMPEs (all of which were considered to be credible--i.e., they passed the test by the Tl Team of being technically defensible interpretations). Tl TEAM -PM Reply: We agree that the justification in terms of CBR of the TDI should be provided, with the added qualifier that the CBR of the TDI needs to be captured for the range of scenarios (magnitude and distance) that contribute significantly to the hazard. We evaluate if we captured the CBR of the TDI for the hazard relevant sources by using hazard calculations based on representative SSC models. Text in Chapter 8 was modified to discuss that the smoother common-form models are adequate because they cover the CBR of the TDI (i.e. candidate GMPEs) for scenarios that are relevant to the hazard. In some magnitude-distance combinations, the suite of common-form models do not fully envelop the prediction of the candidate GMPEs with added epistemic uncertainty, as discussed in the next paragraph. To check that these small exeedances are not at scenarios that control the hazard, the hazard is evaluated using a representative SSC model. These representative hazard results show that the common-form models have an appropriate range (shown later in this section)." Excerpt of Chapter 8, Section 8.4.3 follows in the following pages.

Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 272 8.4.3 Evaluation of Center and Body of the Selected Models 273 The center and body of the distribution of the medians is evaluated by comparing the COFs using the 274 weights described in Section 8.4.2 with the CDF from the candidate GMPEs with epistemic uncertainty 275 (see Figures 8.4-4 and 8.4-5 as examples). Figure 8.4-4 shows CDF for PGA for an M6.5 strike-slip 276 earthquake for a site at Rx"-5 km (on FW). The selected weights (red curve) has a center (CDF "0.5) that 277 is about 0.2 In units greater than the center of the CDF from the finite-fault simulations, about 0.12 units 278 above the GMPEs, and is similar to the CDFs based on the mean residual, prior and likelihood 279 approaches. The average slope of the CDF between CDF"0.1 and CDF"0.9 defines the body of the 280 distribution and, overall, is consistent with the slopes from the other methods eKcept for the GMPE and 281 likelihood approaches which are steeper for this example. These comparisons of the center and body of 282 the distribution change for different scenarios and spectral periods. 283 In addition to the CDF plots, the center and body of the distribution can be evaluated using distance 284 scaling, magnitude scaling, and spectra plots. Figures 8.4-6 and 8.4-7 compare the distance scaling for 285 the 51", so11** and 95'11 fractiles from the logic tree weights with the distance scaling for the candidate 286 GMPEs for PGA and PSA (T"l sec), respectively. The 501h percentile for the selected common-from 287 models is not the same as the so1* percentile of the candidate GMPEs. One reason for this difference is 288 289 that the common-form model weights were partly based on finite-fault simulations that were not part of the dataset used in the candidate GMPEs' derivation. 290 As seen in these figures, the selected models envelope the candidate GMPEs for the larger magnitudes 291 (M6.5 and M7.5) other than at distances less than 3 km. The GMPE that is above the selected model 292 envelope is the ld14 model. As noted in Section 6.2.1, the Tl Team judged the short distance scaling in 293 the ld14 model to be unreliable for large magnitudes and removed the ld14 model at distances less than 294 3 km from the development of the common form models. This apparent inconsistency between the 295 range of GMPEs and the range of the selected common form models reflects the Tl Team's judgment 296 with regard to the ld14 GMPE. The shape of the 5% fractiles for M7.5 shown in Figure 8.4-6 is not 297 smooth due to the relatively small number of common-form models selected (less than 31). 298 At smaller magnitudes (MS.5), the selected common form models do not envelope all of the candidate 299 GMPEs for M5.5 as shown in Figure 8.4-7 (top panel). The differences at M5.5 are related to the sharp 300 breaks in the magnitude scaling for the short period ground motion for some of the candidate GMPEs. 301 Figure 8.4-8 shows the magnitude scaling for strike-slip earthquakes for an Rx distance of 5 km for PGA, 302 T=0.2, T=l, and T=3 seconds. The sharp breaks in the magnitude scaling at MS.5 for one of the GMPEs 303 can be seen in this figure. The selected common form models include breaks in the magnitude scaling at 304 M5.5 and M6.S, but the break is not as sharp and leads to a smoother set of models. The Tl Team judged 305 that the smoother common-form models are adequate because they cover the CBR of the TDI (i.e. 306 candidate GMPEs) for scenarios that are relevant to the hazard. In some magnitude-distance 307 combinations, the suite of common-form models do not fully envelop the prediction of the candidate Chapter 8: Median GMC Models: DCPP Sources Page 8-9 Comment [CDA42): 595 Comment [CDA43]: 596 Comment (CDA44): S97 " Comment [CDA45): 599 Comment [CDA46]: 600 "Comment [CDA47): 593 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 308 GMPEs with added epistemic uncertainty, as discussed in the next paragraph. To check that these small 309 exeedances are not at scenarios that control the hazard, the hazard is evaluated using a representative 310 SSC model. These representative hazard results show that the common-form models have an 311 appropriate range (shown later in this section). 312 Examples of the spectra for M5.S, MG.5, and M7.5 strike-slip earthquakes at a distance of S km are 313 314 315 compared to the range of the candidate GMPEs plus additional epistemic uncertainty in Figure 8.4-9. For M6.5 and M7.5, the selected models envelop the range of the candidate GMPEs plus additional epistemic uncertainty, but at M5.5, not all of the models are enveloped due to the sharp breaks in the 316 magnitude scaling at MS.Sin one of the GMPE models. This issue of adequate range is evaluated later at 317 the end of Section 8.4.3, using hazard curves as the metric of interest. 318 An example of the CDF with a broad distribution of the GMPEs is shown in Figure 8.4-10 for a M5.5 319 earthquake at a distance of 1 km. For the spectral acceleration at T=l sec, the GMPE distribution is 320 much broader than the distribution for the selected models due to the kink in the magnitude scaling at 321 M5.5 for one of the candidate GMPEs. In contrast for PGA, for this same scenario, the GMPE 322 distribution is similar to the selected models as the range of the selected models captures the kink in the 323 magnitude scaling. 324 The centering of the models can also be evaluated in terms of the influence of the different metrics used 325 for computing the weights for the common-form models. Because the simulations are also used to 326 constrain the center and body of the distribution, differences between the center of the simulations and 327 the center of the candidate GMPEs will affect the centering of the selected models. 328 A set of CDF plots and ground motion scaling plots for the scenarios listed in Table 8.4-1 and for a range 329 of spectral periods are shown in Appendix H. The CDFs of the ground motions were reviewed to check 330 the center and body of the distributions. A general result is that the simulations lead to a lower center 331 (PSA at CDF=0.5) for short periods and a higher center for long periods. The center of the full 332 distribution and the body of the upper tail distribution of the selected common-form models are 333 consistent with the distribution of the GMPEs except at an R, distance of 1 km from M5.5 earthquakes. 334 The lower tail has more variability in the shape of the CDF, but it is not as important to the hazard as the 335 upper tail. (The mean hazard is driven by the upper tail because the distribution is skewed. 336 To summarize the evaluation of the centering of the models based on the CDF plots, the changes in the 337 PSA at CDF=0.5 for the different metrics and datasets are computed. Specifically, for each scenario listed 338 in Table 8.4-1, the difference in the ground motion for a single metric and the weighted average model 339 is computed. The distribution of the differences of the In PSA for the 18 scenarios is referred to as an 340 "influence histogram", and is plotted for each statistic and each spectral period. Examples for the R,.,.-341 based models (A models) are shown in Figures 8.4-11, 8.4-12, and 8.4-13 for PGA, and spectral 342 accelerations at T=l sec and T=3 sec, respectively. These plots show the influence of the different Chapter 8: Median GMC Models: DCPP Sources Page 8-10 .. Comment [CDA48): 1036 .. Comment [CDA49): 604 Comment [CDASO]: 601 Comment [CDAS1]: 605

• Comment [CDAS2]: 606 .. Comment [CDA53): 607 Comment Number 1037 -Evaluation of Common-form suite: Chapter 9, Lines 301-313 PPRP Comment: Although it is reasonable to use the hazard as a guide in determining whether the representative models produce a wide enough hazard distribution, it seems appropriate that the distribution of the ground motion models should also be wide enough to encompass the candidate models and their epistemic uncertainty. Please explain that both of these distributions were checked and that the hazard distribution alone is not being used to judge whether the representative suite of models represents the CBR (especially the range) of the ground motion distribution, which should be the intent of a SSHAC Level 3 ground motion study. Tl TEAM -PM Reply: The goal of the SSHAC evaluation is develop a set of ground motion models that capture the CBR of TOI for scenarios that are relevant to the hazard. If the GM models capture the CBR for all scenarios. then it will also capture the range of the hazard. If the range of the GM models does not fully capture the range for all scenarios, then the range of hazard may or may not be captured. Because our model does not capture the full range of the ground motion from the candidate GMPEs with additional (2 sigma) for every scenario, we needed to check that the range of hazard was captured. The main evaluation was in the ground motion space. In developing our weights for the alternative weights approaches (prior, residual, likelihood, data sets), we explicitly evaluated the GM-based CDF and chose a weighting scheme for the weighting approaches that lead to a CDF with an appropriate shape of the CDF (body of the distribution) in addition to the 5th and 95th fractiles (range of the CDF). We then evaluated the range of the hazard as a check that the range of the hazard-significant scenarios is captured. The hazard evaluation is just a check that the approach used to set the weights for weighting approaches, which control the full distribution (CBR), does not miss the range of a key contributor to the hazard. To summarize the comparison of the range from the common-form models and the range from the GMPEs, we added new plots showing the histogram of PSA ratios between the 95th percentile from common-form models and the 95th percentile from the candidate GMPEs (plus epistemic uncertainty). A similar set of plots was prepared for the 5th percentile. Augmented discussion is incorporated in Chapter 6, Section 6.4.5.4. Excerpt of Chapter 6, Section 6.4.5.4 and associated figures follows in the following pages.

Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 892 From the CDF of the ground-motion distribution based on the total weights, the 0.05, 0.5 and 0.95 893 quantiles are calculated, as well as for the candidate GMPE distribution. The candidate GMPEs are 894 equally weighted (as described above). while the common-form model distribution is based on the 895 selected models and total weights. This allows comparing the width and range of the distribution of the 896 selected common-form models and the candidate GMPEs. 897 Figure 6.4.5-3 shows the 0.05, 0.5 and 0.95 quantiles distributions for Model A and for the PVNGS 898 application, for M6.0, normal faulting cases, at T = 0.01 sec, plotted against distance. Figure 6.4.5*4 899 shows the quantiles for the PVNGS (Model A) normal faulting cases, at T = 0.01 sec, plotted against 900 moment magnitude. Figure 6.4.5-5 shows the PSA 0.05, 0.5 and 0.95 quantiles distributions for PVNGS 901 (Model A), for M6.0, strike*slip cases, at R, = *15 km, plotted against periods. The range of the 0.05 to 902 0.95 quantiles from the common*form models is similar to the range from the candidate GMPEs. For 903 some cases, the 0.05 quantile is less stable, leading to a distribution that is skewed to lower values. This 904 905 is not significant for the hazard because the mean hazard is controlled by the upper tail of the motion distribution. 906 AppendiJC H includes several plots showing the 0.05, 0.5 and 0.95 quantiles distributions versus distance 907 and magnitude, for several magnitude and distance values, respectively, in Sections 2.1.6 and 2.1.8 for 908 DCPP (Model A), in 3.1.6 and 3.1.8 for PVNGS (Model A), and 4.1.6 and 4.1.8 for PVNGS (Model B). In 909 addition, the 0.05, 0.5, 0.95 quantiles are plotted against periods, for several scenarios, in Sections 2.1.9, 910 3.1.9 and 4.1.9 of AppendiJC H. 911 6.4.5.4 Range of Distribution 912 To assess the width of the common-form model distribution, the ratios of the 0.05/0.5 and 0.95/0.5 913 quantiles are plotted against distance, for several magnitudes. This is an indicator of possible skewness 914 of the model distribution. 915 Figure 6.4.5-6 shows an el<ample of the 0.05/0.5 and 0.95/0.5 quantiles ratios for Model A and for 916 PVNGS, Rx=-15 km, normal style of faulting, for all periods, and MS (top), M6 (center), and M7 (bottom). 917 The quantile ratios show a broadening of the uncertainty as distance increases from 1 to 50 km, which is 918 counter-intuitive as there is more data in the 30-50 km range than the 1-5 km range for constraining 919 GMPEs. The reason for this increase is that the suite of candidate GMPEs has different distance scaling, 920 as discussed in Section 6.4.5.5. 921 Appendix H includes several plots showing ratios of the 0.05/0.5 and 0.95/0.5 quantiles versus distance 922 for various periods for PVNGS and DCPP, respectively, in Sections 2.1.10, 3.1.10 and 4.1.10. Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-29 Comment [CDA170]: 47S "Comment [CDA171): 464 .. Comment [CDA172]: 463 aod 477 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 923 Although the ranges from the common-form models do not bound the ranges from the GMPEs with 924 additional epistemic uncertainty for all scenarios. the ranges of the st* and 95111 fractiles for the 925 common-form models are, on average, wider than the ranges of the 5th and 95111 fractiles for the GMPEs. 926 The fractiles for the common-form models are based on the weights from the logic trees. The fractiles 927 for the GMPEs with additional epistemic uncertainty are based on using equal weight for each candidate 928 GMPE and using weights of 0.8, 0.1, and 0.1 for the original GMPE and the plus and minus 2 sigma levels 929 for the additional epistemic uncertainty. 930 The histogram of the ratios of the 95** fractiles from the common-form models to the 95** fractiles of 931 the GMPEs for DCPP for strike-slip earthquakes is shown in the top frames of Figure 6.4.5-7. All of the 932 spectral periods are included in the histogram. The lower frame shows the ratios of the 5th fractiles. 933 The histograms for the 95** fractiles are centered on values greater than 0, indicating that the 95** 934 fractiles for the common-form models are, on average, higher than the 95** fractile for the GMPEs. The 935 histograms for the 5'11 fractile are centered on values less than 0, indicating that the 51" fractiles for the 936 common-form models are, on average, lower than the 5** fractile for the GMPEs. This indicates that the 937 common-form models are, on average, yielding a wider range than the candidate GMPEs, but they are 938 not broader for every scenario. 939 Similar histograms of the ratios of the 95** fractiles and 5t* fractiles are shown in Figure 6.4.5-8 for DCPP 940 for reverse earthquakes. The histograms for PVNGS are shown in Figures 6.4.5-9 and 6.4.5-10 for RRuP-941 based models for strike-slip and normal earthquakes, and in Figures 6.4.5-11 and 6.4.5-12 for R18-based 942 models for strike-slip and normal earthquakes. In all of the plots, the histograms are shifted to wider 943 distributions for the common-form models, but for the R,A-based models, the shift is small. 944 There are some scenarios for which the GMPEs give a wider range than the common-form models in all 945 of the plots. Part of the Tl Team's evaluation is to set weights for the common-from models which are 946 not just based on equal weight to each GMPE. Using different weights, the s** and 95*h fractiles for the 947 GMPEs are expected to be different from the fractiles for the common-form models. Also, the shapes of 948 CDFs of the common-form models (e.g. Figures 6.4.5*2 a through c), tend to be smoother than the 949 shapes of the CDFS for the common-form models. The less smooth CDFs of the GMPEs leads to some 950 cases for which the GMPE fractiles are broader than the common-form model fractiles. 951 6.4.5.5 Epistemic Uncertainty in Distance and Magnitude Scaling 952 Figures 6.4.5-13 and 6.4.5-14 show range of distance and magnitude scaling in the selected common-953 form models for PVNGS (Model A), normal style of faulting, and T = 0.01 sec, compared to the scaling of 954 the candidate GMPEs and the candidate GMPEs with epistemic uncertainty. The epistemic uncertainty 955 of magnitude and distance scaling which is contained in the models is assessed by calculating the ratios Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-30 .. Comment [CDA173]: 1037 3C* T =ALL sof = o DCPP4 ModelA 2C t..: *c C* -0.2 -0.1 1861 T =ALL 2C* sof = o DCPP4 ModelA t..: *c C* 1862 0.0 0.1 -0 2 C.O Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 i::*.3 C.-1 02 lnnatio 1863 Figure 6.4.5-7: Ln ratio of the s'" and 95'" fractile of the median spectral acceleration from the common 1864 for models to the 51* and 951" fractile of the median spectral acceleration from the GMPEs with 1865 additional epistemic uncertainty (assuming equal weight to each GMPE). Top frame is for the histogram 1866 of the In ratios of the 95'" fractile for DCPP for strike-slip earthquakes. Bottom frame is for the histogram 1867 of the In ratios of the 511' fractile for DCPP for strike-slip earthquakes. Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-114 T =ALL *IC sof = 1 DCPP4 3C* ModelA t..: 2C *c C* -C.3 -0 2 1868 3C T =ALL sof = 1 DCPP4 2C ModelA t..: *:: *c* C* -C.5 -0 4 1869 -:: , Q.{l i::0.1 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 0.2 C.3 Int ratio 1 -0 3 -0.2 -0 1 c*.O C. 1 02 lnnatio 1870 Figure 6.4.5-8: Ln ratio of the s'" and 95'" fractile of the median spectral acceleration from the common 1871 for models to the 511' and 951" fractile of the median spectral acceleration from the GMPEs with 1872 additional epistemic uncertainty (assuming equal weight to each GMPE). Top frame is for the histogram 1873 of the In ratios of the 95"* fractile for DCPP from reverse earthquakes. Bottom frame is for the histogram 1874 of the In ratios of the s'" fractile for DCPP for reverse earthquakes. Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-115 T =ALL sof = o PVNGS2 *IC ModelA t..: j() 2C *c* C* -C.2 1875 f1C T =ALL sof = o *IC PVNGS2 ModelA j() t..: 2C* 'C* C* -C.f> 1876 0.0 0 00 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 0 *! Int ratio 1 -02 C.O lnnatio 1877 Figure 6.4.5-9: Ln ratio of the s'" and 95'" fractile of the median spectral acceleration from the common 1878 for models to the 511' and 951" fractile of the median spectral acceleration from the GMPEs with 1879 additional epistemic uncertainty (assuming equal weight to each GMPE). Top frame is for the histogram 1880 of the In ratios of the 95'" fractile for PVNGS for strike-slip earthquakes, RRup-based models. Bottom 1881 frame is for the histogram of the In ratios of the s'" fractile for PVNGS for strike-slip earthquakes, R<u,-1882 based models. Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-116 1883 1884 1885 1886 1887 1888 1889 1890 1891 GC* *IC t..: )C 2() *c* C* *IC* 3C* t..: 2C* 'C* C* T =ALL sot= 1 PVNGS2 ModelA -0 3 -C-.2 T =ALL sot= 1 PVNGS2 ModelA -:: , 0.0 0.1 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 02 OJ C.-1 -OG 0 2 C.O 0 2 CA lnnatio Figure 6.4.5-10: Ln ratio of the s'" and 95'" fractile of the median spectral acceleration from the common for models to the 511' and 951" fractile of the median spectral acceleration from the GMPEs with additional epistemic uncertainty (assuming equal weight to each GMPE). Top frame is for the histogram of the In ratios of the 95'" fractile for PVNGS for normal earthquakes, R*ur-based models. Bottom frame is for the histogram of the In ratios of the s'" fractile for PVNGS for normal earthquakes, R1,up*based models. Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-117 7C* GC 5C* *IC t..: 3C* 2C* *c C* -C.2 1892 GC* *IC* t..: 3C* 2C *c C* -C.6 1893 T =ALL sof = o PVNGS2 ModelB -C .* T =ALL sof = o PVNGS2 ModelB -C.*1 -0 2 c*.O Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 ().\ C.5 C.2 lnnatio 1894 Figure 6.4.5-11: Ln ratio of the s'" and 95'" fractile of the median spectral acceleration from the common 189S for models to the 511' and 951" fractile of the median spectral acceleration from the GMPEs with 1896 additional epistemic uncertainty (assuming equal weight to each GMPE). Top frame is for the histogram 1897 of the In ratios of the 95'" fractile for PVNGS for strike-slip earthquakes, R18-based models. Bottom frame 1898 is for the histogram of the In ratios of the 511, fractile for PVNGS for strike*slip earthquakes, R1,.-ba.sed 1899 models. 1900 Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-118 T =ALL 6C* sot= 1 5C* PVNGS2 ModelB -IC t..: '.>C 2C *c* C* -'::0.2 1901 T =ALL 4C sot= 1 PVNGS2 3C* ModelB t..: 2C* *c C* -'J 6 1902 -JC Q/ Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 0.-1 Int ratio 1 -0 .; --:*. 2 0 0 2 lnnatio 1903 Figure 6.4.5-12: Ln ratio of the s'" and 95'" fractile of the median spectral acceleration from the common 1904 for models to the to the 51" and 951" fractile of the median spectral acceleration from the GMPEs with 1905 additional epistemic uncertainty (assuming equal weight to each GMPE). Top frame is for the histogram 1906 of the In ratios of the 95'" fractile for PVNGS tor normal earthquakes, R,8*based models. Bottom frame is 1907 for the histogram of the In ratios of the s'" fractile for PVNGS for normal earthquakes, Rw*based models. 1908 1909 1910 Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-119 Comment Number 1038 -Short-range saturation: Chapter 6, Lines 40-41 PPRP Comment: Please reconcile the statement that the finite-fault simulations "all show saturation at short distances" with the statement on Line 697 of Appendix J (and evidence in Figure J.4.3-1) that "the GMPEs have stronger saturation than the EXSIM model at very close distances." If it is correct that EXSIM has less saturation at short distances, please explain why this should not be interpreted as support for the ld14 model (e.g., is the formulation of EXSIM such that it is not intended by its developers for use at the shortest distances? Or does the Tl Team argue on physical grounds that EXSIM is not reliable at short distances?). Tl TEAM -PM Reply: The first part of the question points at an internal inconsistency between Chapter 6 and Appendix J, which the Tl Team also acknowledges. Edits were provided to Chapter 6 to improve clarity. The Tl Team notes that there is no specific mention of saturation issues with EXSIM at distances less than 5 km in Assatourians and Atkinson (2015), Venier and Atkinson (2014), nor the earlier papers. Thus the only citation appears to be her comments at our special working meeting, and a recent email communication: Since Gail Atkinson has indicated at the January 28-29, 2014 special working meeting, and also in subsequent email correspondence that the method does not saturate as strongly as observations for distances less than 5 km. the method is deemed less reliable in this distance range and therefore cannot be used as an argument for ld14 and very near distances. Lastly, the Tl Team remarks that EXSIM is not used in the Sammon's map approach to generate a suite of common-form models, instead is used for residuals (together with the other two validated FFS simulations methods) in the weighting scheme. As a result, its behavior to short distance and high frequency does not impact the residuals too much. On the contrary, the ld14 model is used in the generation of the base model via Sammon's map, so the Tl Team's assessment of the unreliable M-R range has important downstream effects in the generation of reliable suite of the common-form models. Comment Number 1039 -Short-range saturation: Chapter 6, Lines 47-61 and Figure 6.2.1-2 PPRP Comment: The 1014 model was deemed unreliable by the Tl Team in the range of M 7.5 and Rs 3km. The description of the Tl Team's justification is based mainly on the interpretation that 1014's predicted median PGA is an outlier (it is higher by about 40% than the predictions of other candidate GMPEs). However, the predicted median at Rs 3km for T = 2s from the ZL 11 and the ZH06 GMPEs are also much higher than the other GMPEs (by more than 50%), but neither were rejected (Figure 6.2.1-2). Please justify the seemingly inconsistent assessments. Tl TEAM -PM Reply: The reason for rejecting ld14 and not ZH06 and ZL 11 is the following: ZH06 and ZL 11 are much higher than the other GMPEs over a wide distance range, whereas the ld14 model is much higher only at short distance range. Because the 1014 model is based on a much smaller number of near-fault data (due to restricting the data to VS30>450 m/s), there is much less constraint on the short-distance scaling. The Tl team judged that the distance scaling for large magnitudes is not as well constrained in the 1014 model as it is in the other NGA-E2 GMPEs which had the advantage of using the much larger data set that included soil data at short distances. The Tl team judged that the overall higher level of ground motion in the ZH06 and ZL 11 represented credible alternative scaling models that should be included. Explanatory text was added to Chapter 6. Excerpt of Chapter 6, Section 6.2.1 and associated figures follows in the following pages. Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 1 6 GMC MODELS FOR THE MEDIAN: OVERVIEW AND 2 METHODOLOGY 3 4 6.1 Introduction S This Chapter describes the evaluations of the candidate GMPEs selected for the median ground motion 6 compiled in Section 5.5. In addition, the alternative adjustment factors to account for hanging-wall 7 effects, directivity effects, and path effects on the median are described and evaluated. The evaluations 8 of the weights for the logic trees for the median for DCPP and PVNGS are described in Chapters 8 and 9, 9 respectively. 10 A new methodology is used to develop the suite of alternative median models based on the Sammon'.s 11 map representation of the alternative magnitude and distance scaling of the GMPEs. The Sammon's 12 map method is described in Attachment E. In this approach, the selected candidate GMPEs are 13 expanded to develop continuous distributions of the median GMPEs which can then be discretized into 14 representative models that are mutually exclusive and collectively exhaustive. This new method, 15 described in Section 6.4, allows the Tl Team evaluations to better capture the center, body and range of 16 median GMPE predictions. The application of the Sammon's map is limited to 17 periods ranging 17 between 0.01 (PGA) and 3 seconds, listed in Table 6.1-1. The spectral accelerations for the suite of 18 median models for periods above 3 seconds are based on the period scaling of NGA-West2 GMPEs 19 beyond 3 seconds, as described in Appendix N. 20 21 6.2 Evaluation of Candidate GMPEs for the Median 22 6.2.1 Evaluation of Candidate GMPEs for DCPP 23 Section 5.5 de.scribed the selection of the candidate GMPEs for the median ground motion. The eight 24 candidate GMPEs selected for application to DCPP are listed below: 25

• Abrahamson et al. (2014), referred to as ASK14 26
• Akkar et al. (2014a, 2014b), referred to as ASB14 Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-1 Comment [CDAl]: 321 "Comment [CDA2]: 322 "Comment [CDA3): 391 , Comment [alex4): #323 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 27
• Boore et al. (2014), referred to as BSSA14 28
• Campbell and Bozorgnia (2014), referred to as CB14 29
• Chiou and Youngs (2014), referred to as CY14 30
• Idriss (2014), referred to as ld14 31
• Zhao et al. (2006), referred to as ZH06 32
• Tl Team implementation of Zhao and Lu (2011), referred to as Zlll (Section 5.5.1.1) 33 Based on the discussions in Section 5.5, the eight candidate GMPEs are all considered to be applicable to 34 35 36 OCPP for magnitudes 5.0-8.0, distances of 0-30 km, and periods of 0-3 sec for strike-slip and reverse earthquakes for sites on the footwall side with the following exceptions: the ld14 model is not considered applicable for distances less than 3 km for large magnitudes (M > 7.5) and the ASB14 model 37 is not considered applicable to magnitudes greater than 7.5. The technical justification for these 38 exceptions is given below. 39 For the ld14 model, there is a strong distance slope of the short-periods spectral values for large 40 magnitudes for distances less than S km. The other candidate GMPEs and two of the finite-fault 41 simulations (GP -Graves and Pitarka, 2015; and SDSU -Olsen and Takedatsu, 2015; see Section 5.2 and 42 Appendix J and references therein for more information) show saturation at short distances for short 43 periods. While the EXSIM method (Atkinson and Assatourians, 2015) in the SCEC validation of 44 broadband simulation methods also showed acceptable saturation with the limited data set, SWUS 45 scenario simulations indicate that it does not saturate as strongly as the other two simulation 46 approaches used nor as strongly as the GMPEs. The developer Gail Atkinson noted at the January 28-47 29, 2014 Special Working Meeting that, at distances less than 5 km, there may be additional 48 unmodeled saturation effects. Since Gail Atkinson has indicated at the January 28-29, 2014 special 49 working meeting, and also in subsequent email correspondence that the method does not saturate as 50 strongly as observations for distances less than 5 km, the Tl Team judges the EXSIM method to be 51 deemed less reliable in this distance range and therefore cannot be used as an argument for accepting 52 ld14 and very near distances. Lastly, EXSIM is not used in the Sammon's map approach to generate a 53 suite of common-form models. Instead, it is used for residuals (together with the other two validated 54 FFS simulations methods) in the weighting scheme. As a result, its behavior to short distance and high SS frequency does not impact the residuals too much. On the contrary, the ld14 model is used in the 56 generation of the base model via Sammon's map, so the Tl Team's assessment of the unreliable M-R 57 58 range has important downstream effects in the generation of reliable suite of the common-form models. 59 Figure 6.2.1-1 shows the median spectra for an M7.S strike-slip earthquake. At 5 km distance, all five 60 models are in a similar range in the short periods, but at 1 km, the Idriss (2014) model is outside the 61 range of the other candidate GMPEs due to the stronger distance scaling in this short distance range. Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-2 Comment [CDAS): 325 "Comment [CDA6): 326 Comment [CDA7]: "Comment [CDAS): 327 ,. . Comment [CDA!>): 1038 , Comment [alexlO): #328 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 62 There is very little empirical data to constrain the short-distance large-magnitude scaling. For M 7.2, 63 R<JP 5 10 km, Rx < 0 km (excludes HW sites), Vs30 > 450 m/s (subset of Vs30 used by ld14), and requiring 64 more than one recording from an earthquake to constrain the distance scaling, the NGA-West2 data set 65 contains only 19 recordings, all of which are from the Chi-Chi earthquake. If the V530 range is expanded 66 to include soil sites (as used by the other four NGA-West2 modelers), then the short distance, large 67 magnitude data set on the footwall (FW) increases to 35 recordings of which 30 are from Chi-Chi, 3 are 68 from Kocaeli, and 2 are from Landers. While the short-distance scaling in the ld14 model at M6.6 is 69 slightly steeper than any other candidate GMPE models (Figure 6.2.1-1 lower panel), it is still in the 70 overall range of the other models and the finite-fault simulations; however, at large magnitudes (M7.5, 71 shown in Figure 6.2.1-1 upper panel), the short-distance slope is even steeper than M6.6 and does not 72 show saturation. Because the short-distance scaling in the ld14 model leads to a model that is an outlier 73 from the other GMPEs and from the finite-fault simulations, and furthermore, because the ld14 short-74 distance large-magnitude scaling is based on a more limited data set due to the narrower range of V530 75 values used by Idriss, the Tl Team judged that the ld14 model is not reliable in the short distance range 76 (53 km) for larger magnitudes (M 7.5). 77 For the ASB14 GMPE model, the scaling above M7.5 is not well constrained by the empirical data used 78 to derive the model: the only earthquake above M7.5 in the ASB14 data is the M7.51 Kocaeli 79 earthquake (magnitude from the PEER NGA-West2 database). Because the M > 7.5 scaling in the ASB14 80 model is based on only one earthquake and this earthquake is part of the larger NGA-West2 data set, 81 the ASB14 model does not add information on the large magnitude scaling. Therefore, the Tl Team 82 judged that the ASB14 model should not be applied for magnitudes greater than 7.5. 83 84 85 86 Although previous hazard sensitivity studies (Section 4.1.4) showed that sources at large distances (30-300 km) do not contribute significantly to the hazard at DCPP for hazard levels less than 10*3 {the deaggregation for 1 Hz shown in Figure 4.1-4b indicated that there is no contribution to the hazard for distances greater than 50 km), the GMPEs still need to scale in a reasonable way to the large distance 87 for all sources. As long as the large-distance scaling is not unreasonable, then the GMPEs can be used 88 for the distant sources. A comparison of the distance scaling for 0.5 Hz is shown in Figure 6.2.1-2: the 89 ASB14 GMPE model has the weakest attenuation with distance but there is still not a significant effect 90 on the hazard. Figure 6.2.1-2 also shows that the predicted median by ZH06 and Zlll are much higher 91 than the predicted median by ld14 at short distance. In general, the predicted median by ZH06 and Zlll 92 are higher than the other GMPEs over a wide distance range, whereas the ld14 model is much higher 93 only at short distance range. The Tl Team judged that the overall higher level of ground motion in the 94 ZH06 and Zlll represented credible alternative scaling models that should be included. As mentioned 95 above, because the ld14 model is based on a much smaller number of near-fault data {due to restricting 96 the data to Vslo > 450 m/s), there is much less constraint on the short-distance scaling. The Tl Team 97 judged that the short-distance scaling for large magnitudes is not as well constrained in the ld14 model 98 as it is in the other NGA-West2 GMPEs which had the advantage of using the much larger data set that Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-3 Comment [CDA11]: #329 " Comment [CDA12): 330 Comment [CDA13): 331 r "Comment [CDA14): 332 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 99 included soil data at short distances. 100 The Tl Team judged that the large distance scaling in the candidate GMPEs is reasonable for application 101 to DCPP because there is no significant contribution (less than 3% contribution as shown in Figure 4.1-3 102 for 1 Hz} to the hazard for hazard levels less than 10*3 for any of the GMPEs. 103 6.2.2 Evaluation of Candidate GMPEs for PVNGS for Greater Arizona Sources 104 Section 5.5 described the selection of the candidate GMPEs for the median ground motion. The six 105 candidate GMPEs selected for application to PVNGS for Greater Arizona sources are listed below: 106 107 108
• Abrahamson et al. (2014), referred to as ASK14
• Akkar et al. (2014a, 2014b), referred to as ASB14
• Bindi et al. (2014a, 2014b), referred to as Bi14 109
• Boore et al. (2014), referred to as BSSA14 110
• Campbell and Bozorgnia (2014), referred to as CB14 111
• Chiou and Youngs (2014), referred to as CY14 112 Based on the data sets used to derive the models, the Tl Team judged that the six candidate GMPEs are 113 applicable to normal and strike-slip earthquakes with magnitudes 5 to 7.5 at distances of 0 to 200 km 114 with the exception that the Bi14 model is not considered to be applicable to magnitude greater than 7.0 115 based on the strong change in the magnitude scaling for S Hz. The magnitude scaling of the candidate 116 GMPEs for 5 Hz for strike-slip earthquakes at an Rx distance of 5 km is shown in Figure 6.2.2-1. As 117 evident from the Figure 6.2.2-1, the Bi14 model shows an increase in the magnitude scaling above M7, 118 whereas the other candidate GMPEs for DCPP show magnitude saturation. Based on this trend, the Tl 119 Team judged that the Bi14 model is not applicable for M > 7 for 5 Hz. This feature of the Bi14 model is 120 not seen for all spectral frequencies, but for simplicity of application, the Tl Team decided not to use the 121 Bi14 model for M > 7 for all spectral frequencies. 122 6.2.3 Evaluation of Candidate GMPEs for PVNGS for Distant California and Mexico 123 124 125 126 Sources Previous hazard sensitivity studies (Section 4.2.3) showed that distant California and Mexico earthquakes could have a significant contribution to the low frequency hazard at PVNGS. The relevant sources are mainly large magnitude (M7 to M8.5) strike-slip earthquakes. The issue of the 127 application of the GMPEs to these sources is the large-distance attenuation from California to central 128 Arizona, and, in particular, whether the attenuation from California to central Arizona is different from 129 the attenuation within California. Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-4 Comment [CDA15]: , Comment [CDA16): B3 , Comment [alex17): , Comment [alex18): 034 Comment [CDA19): 335 .. Comment [CDA20]: ns Comment [alex21]: 041 Comment [CDA22): 336 , Comment [alex23): , Comment [CDA24]: n1 Comment [CDA25): 338 0.1 1 1575 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 Distance Scaling (M7.5 SS, PGA) ..... __ .... _______ _ o.: -AS*:l4 ---A.$814 ce:4 ('j -Zlll -1)!4 Rupture Distan<e I krnl Distance Scaling (M6.6 SS, PGA) -B>SA14 CB14 (y 14 -*L: land -1)14 Mioain F S 1mLI a ti -Rupture D*st;once lkm I 10 10 1576 Figure 6.2.1-1: Distance scaling of the 5%-damped response spectra (PSA) at PGA for the candidate 1577 GMPEs for a M7.S strike-slip event (top panel) and MG.6 strike-slip event (bottom panel). The mean of 1578 the finite fault (FF) simulations available for M6.6 is also shown in the bottom panel. The Zlll and ZH06 1579 PSA are identical at M6.6. Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-58 1S80 v ... .. N II I-@J B cf "' Q, 1581 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 Distance Scaling (M7 SS, 0.5 Hz) 1 0.01 --ASK14 --BSSA14 CB14 CY14 0.001 --ld14 A5B14 --ZH06 and Zll 1 Bi14 0.0001 1 10 100 R*u* Distance (km) 1582 Figure 6.2.1-2: Distance scaling of the candidate GMPEs at 0.5 Hz for a M7.0 strike-slip event. The Zll 1 1583 and ZH06 PSA are identical at M7.0. 1584 1585 Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-59 1586 T=0.2 1.00 SS 0.70 _..., C> .......... <( 0.50 (/) CL 0.30 0.20 Rx=5 5.0 5.5 6.0 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 .... ;** *_, .. 6.5 M .,-* ... ,,-** .::*-.-:: :: ... _:::..:.-7.0 *ASK14 *ASB14 *Bi14 1 BSSA14 oCB14 CY14 7.5 8.0 1587 Figure 6.2.2-1 Magnitude scaling of the candidate GMPEs at 5.0 Hz for strike-slip event with Rx distance 1588 5 km. 1589 Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-60 Comment Number 1040 -Consistency of Key Equations: Chapter 6, Lines 409,410 PPRP Comment: The parameters FREv and FNML defined on these lines do not appear in Eq (6.4-1 ). On the other hand, F in Eq 6.4-1 is not defined. Furthermore, this equation differs from what would seem to be intended to be its equivalent in Appendix C, Part II, Line 33, where FREv and FNML appear, but not F, and an additional coefficient a10 appears that is absent in 6.4-1. Also, coefficient a9 is squared in 6.4-1, but not in the Appendix C counterpart. It would be beneficial and less confusing to many readers if the same terminology for predictor variables used in the West1 and NGA-West2 projects were used throughout the report. For example, please consider replacing "FREv" and "FNML" with "FRv" and "FNM" (and note, as mentioned above, that these terms are not actually used in Eqs (6.4-1) and (6.4-2) and instead only a single "F" indicator variable is used in these equations). Please replace "F" in these equations with the mechanism-specific predictor variables or modify the text accordingly, and in any case make changes to ensure consistency with Appendix C. It is likely that the inclusion of a tenth coefficient in the text that follows refers to the inclusion of two predictor variables to represent the style-of-faulting. If this is the case, and the equations are corrected, then please ignore those comments that refer to the missing tenth coefficient elsewhere in the list of comments. Tl TEAM -PM Reply: The PPRP is correct. The two formulas were corrected to insert the missing style-of-faulting factors and coefficients. Corrections applied to Chapter 6 and Appendix C -Part 11 No change was applied to the FREv and FNML notation to be consistent with the notation used throughout the report and in the HID Excerpt of Chapter 6, Section 6.4. 1 and Appendix C -Part II follows in the following pages.

Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 427 based on the comparisons with hazard relevant data sets (empirical and/or simulated) and with the 428 density of the suite of representative models within each cell, to represent the center, body and range 429 of median predictions. The representative model for each cell is defined as the model leading to a 430 hazard curve that is the closest to the mean of the hazard curves from all the models within a given cell. 431 In particular, the model is selected by minimizing the variance of the difference in the log hazard for the 432 model and the log of the mean hazard for the cell measured over a range of ground motion levels. The 433 mean hazard is used because the primary use of the SWUS GMC models will be to develop mean hazard 434 curves for the NPP sites. 435 The use of the visualization technique for the sampling of the suite of common-form models is applied 436 to the DCPP sources and to the Greater Arizona sources for PVNGS. The ground-motion models 437 addressing the ground motion for PVNGS from sources located in central and southern California and 438 Mexico is treated with a different approach based on as-published GMPEs with path-specific adjustment 439 factor to take advantage of the available ground motion data in Arizona from these sources (see Section 440 6.2.3 for details on the approach, and Section 9.2 for the technical justification). 441 6.4.1 Fitting Candidate GMPEs to a Common Functional Form 442 In the first step, the candidate GMPEs are fit to a common functional form, which allows an evaluation 443 of the distributions of the coefficients. This step is necessary because the GMPEs use different functional 444 forms and the coefficients cannot be directly compared between GMPEs. By using the common form, 445 the mean and covariance of the resulting sets of coefficients can be estimated. This gives a distribution 446 of the set of coefficients, which can be sampled to generate a large suite of new common-form models. 447 These new models lead to a continuous distribution of median models which fill in between the 448 candidate GMPEs as well as broadening the range of models beyond the range of candidate GMPEs. 449 Based on the evaluation of these new common.form models, which is done by comparing them to data 450 and simulations. a subset of common-form models is selected and weighted appropriately to capture 451 the center, body and range of median PSA predictions. 452 Two functional forms were used for the common-form models: one based on rupture distance (called 453 Model A) and one based on Joyner-Boore distance (called Model B). The common form for Model A is 454 given in Equation 6.4-1 and was selected based on the magnitude, distance, depth, and style-of-faulting 455 dependence in the candidate GMPEs. Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-14 , Comment [CDA81]: 403 >Comment [CDA82]: 365 Comment [CDA83): 367 "Comment [CDA84): 366 Comment [CDA8S]: 367 Comment [CDA86]: 367 Comment [CDA87]: 367 Comment [CDA88): 367 Comment [CDA89): 368 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 L11(SA11,s1:<M .R1/(1,,Zm1<*F. T)) = t{)(T)-exp(B, (T))R11t:f' + exp(B, (T))Z70" + exp(8rn(T))F,11w 456 +( 04(T)+ + 06(T)2 )-cxp(0.>(T))t:v,1n + 16\(T)(S.5-6.5) + 82(T)(M -5.5) }hr M < 5.5 Ol(T)(M -6.5) .for5.5 M 6.5 0;( T)( M -6.S) for M > 6.5 457 (Eq. 6.4-1) 458 459 where SAllAsF refers to the model without HW effects (called the base model), M is moment magnitude, 460 RRuP is rupture distance in km, Zro* is the depth to the top of rupture in km. F*ev is a flag for the reverse 461 (REV) style-of-faulting (i.e. F*ev = 1 for REV sources, and is zero otherwise), and FNML is a flag for the 462 normal {NML) style-of-faulting (i.e. F * .,L = 1 for NML sources, and is zero otherwise). The coefficients for 463 the linear distance, style of faulting, and rupture depth in the common-form model ( 87, 8.) and 8,., J 464 are fit using the exp( O{) (fork = 7. 8, 9, I 0) to ensure that the terms are positive for all four 46S coefficients. A similar form is used for Model B, but with R,J* replaced by R1". There is no site term (e.g. 466 in the common form because the application is for a single reference site condition with 467 = 760 m/s. 468 To focus the common form on the most important sources, the fitting of the common form used 469 different faulting styles for the two sites: for DCPP, the common form is derived for strike-slip (SS) and 470 REV earthquakes only and a single NML factor is added at the end; for PVNGS, the common form is 471 derived for SS and NML earthquakes only and a single REV factor is added at the end. For adding the 472 style-of-faulting (SOFJ factors at the end, smoothed average NML factors for DCPP are computed based 473 on the mean style-of-faulting factor for NML earthquakes in the eight candidate GMPEs for M6.5, z10* = 474 0 km, Rx = -30 km. Because the NML faulting events do not contribute significantly to the haz.ard at 475 DCPP (as discussed in Section 4.1), only a single scenario was used to evaluate the NML style-of-faulting 476 factor. For PVNGS, the same approach is used to compute the average REV style*of-faulting factor based 477 on the six candidate GMPEs. Similar to DCPP, only a single scenario was used to evaluate the REV style of 478 faulting factor because the REV faulting events do not contribute significantly to the hazard at PVNGS (as 479 discussed in Section 4.2.2). 480 For the regression, the exp( Bk) terms (fork = 7, 8, 9, t 0) are replaced by a;. Thus, the following 481 function is used for the prediction of PSA values using the sampled functions (Eq. 6.4-2): Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-15 .. " Comment [CDA!>O]: 364 Comment [CDA!>l]: 369 Comment [CDA!>2]: 3n Comment [CDA!>3): 1040 Comment [CDA!>4): 370 Comment [CDA!>S): #371 Comment [CDA!>6): 37S Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT-Rev.1 l11(SA11,s1(i\4 ,R,11:"'Z11111, F, T)) = a11(T)-a;(T)R,11:" + 482 +(a4(T)+a5(T)(,o\rl + f-a1(T)(5.5-6.5)+a2(T)(,o\.1-5.5) forM <5.5 l a,(T)(M-6.5) jilr5.5::S,M::S,6.5 a)(T)(M-6.5) fc>rM>6.5 483 (Eq. 6.4-2) 484 where ak = B, for k = 0, 1.. .. 6 and ak Ok fork= 7,8, 9, IO. Using the square of the aA terms 485 fork= 7, 8, 9 and 10 ensures a positive value for these parameters. 486 To evaluate the suitability of the common form in Eq. 6.4-2 to fit the candidate GMPEs, the Tl Team 487 inspected the comparisons of the scaling in the original candidate GMPEs with the scaling in the fitted 488 common-form models. Examples comparing the distance scaling of the candidate GMPEs for DCPP and 489 PVNGS with the fitted common form models for PGA and T = 1.0 sec are shown in Figures 6.4.1*1 to 490 6.4.1-3 for the DCPP, PVNGS (Model A) and PVNGS (Model B), respectively. Based on inspections of the 491 fits, the Tl Team judged that the function in Eq. 6.4-2 is flexible enough to capture the full range of 492 scaling in the selected candidate GMPEs. 493 The Zro< term is included for the R,J,-based common-form models, but not for the R18*based common* 494 form models, because the candidate GMPEs which use Rm as their primary distance metric (ASB14, 495 BSSA14, Bil4) do not include Zm* depth-scaling. Therefore, for the common-form models. 496 a,= 0. For the R10-based common-form models fit to the candidate GMPEs with z,0* effects (e.g. 497 ASK14, CB14 and CY14), the Zro* scaling is not maintained. This is a feature of the Rie metric which does 498 not include depth effects. For the R*up*based common-form models, the candidate GMPEs are evaluated 499 at three z10* values per magnitude, centered on the mean z,0* from the Z,0.-M relationship developed 500 by CY14. The high and low values are +/- 3 km from the mean Zro*-M relationship of CY14, with the 501 constraint that Zro* is greater or equal to 0 km. 502 6.4.l.l DCPP Fitted Models 503 For each of the eight selected candidate GMPEs for DCPP listed in Section 6.2.1, median predictions (in 504 In units) are calculated for MS to MS, Rx-= -2 to -200 km, V530-= 760m/s, and strike-slip and reverse 505 faulting mechanisms are included. The magnitudes and distances used to define the scenarios for fitting 506 the candidate GMPEs for DCPP are listed below: 507

• M:: 5.0, 5.2, 5.4, 5.5, 5.6, 5.8, 6.0, 6.2, 6.4, 6.5, 6.6, 6.8, 7.0, 7.2, 7.4, 7.5, 7.6, 7.8, 8.0 Chapter 6: GMC Models for the Median: Overview and Methodology Page 6-16 ,. Comment [CDA97): 374 Comment (CDA!IS): 375 and 376 Comment (CDA99): 1040 .. Comment [CDAtOOJ: 732 Comment (CDAlOl): 377 Comment (CDA102): 378 Southwestern United States Ground Motion Characterization SSHAC Level 3 TECHNICAL REPORT -Draft Rev. 1 27 GMPE 0.2 ASK14 0.2 BSSA14 0.2 CB14 0.2 CY14 0.2 1014 28 29 Figure 1-2: Logic Tree for Median at DCPP 30 Additional Epistemic Uncertainty 1.6 sigmaMu (M=8) 0 -1.6 sigmaMu (M=8) 31 2.2 Common Functional Form for Base Model 32 The functional form of the DCPP base model GMPEs is given in Eq. 2-1: Ln ( SAHr.w*(A1, RIWI" zlOR' F, T)) = ao(T)-a;(T)RIWI' + a;(T)ZroR + 33 +( a4(T) + a5(T)(M -5) )ln( + + forM<5.5 I a1(T)(M-6.5) for5.5sMs6.5 . a3(T)(M-6.5) forM>6.5 34 (Eq. 2-1) 35 The coefficients for 17 spectral periods and up to 31 models are listed in excel files named 36 "Coefficients_Weights_DCPP _TX.csv", where Xis the period, which are collected under the folder 37 "DCPP _Coefficients_Weights-11262014", which is provided as an electronic attachment to the HID. 38 The list of the included excels files and their contents are described in section 4. There may be less Appendix C: Final SWUS GMC Models Hazard Input Documents (HIDs) Part II: DCPP, Rev.1 Page C Part II -3 TIER 2 COMMENTS Comment Location in Text PPRP Comment Summary of Revisions to Report Number Tier 2 Comments (by chapter) General 1033. NIA Please carefully review the references for completeness and to ensure that all cited references are listed. For example, some of the same references in different chapters are listed slightly differently (i.e., one might be missing a volume number or page numbers while another miaht not). 1034. NIA The report is written primarily in third person, which implies that the An author list is now included in the TOC (third page). writers of the report, chapter, and/or section performed the work or made the decisions and assumptions that are being described. However. there A comprehensive check will be made to ensure that the are no specific authors listed on the report, which is only identified by the personnel performing the evaluations or assessments are clearly publisher, GeoPentech, and a list of participants in the project Please defined. make it clear who the writers of the report are either on the Title Page (ideally) or in the introduction so that there is clear ownership of the work that is being described in the third person. When the description refers to someone else's work, decision. or assumptions, please make it clear that this is the case. There are also still sporadic uses of the pronouns *'we" and "us" throughout the report, which is even more ambiguous. Please consider replacing these pronouns with the person or group that the pronoun refers to (e.g., the Tl Team or a specific Resource Expert) or change the sentence to third person to refer to the identified writers of the reoort. CHAPTER 0-Table of Contents 1035. NIA The Section No. 5.2.1.1 appears twice. The second one should be fixed 5.2.2.1. 1036. NIA In the title of Section No. 5.5.3, Vs should be Vs30. fixed 1037. NIA The Section No. 6.4.5.3 appears twice. The first occurrence should be fixed 6.4.5.2. CHAPTER 1-Introduction 1038. Lines 57-58 The description of Vs3c as "shear-wave velocity" should be more done in both locations accurately described as "travel-time-averaged shear-wave velocity." This change also applies to the definition of Vs3n in the list of terms and acronvms. 1039. Line 63 Please define "kappa," since this is the first time that this term is used in done in both locations the report. Please also add the definition of kappa to the list of terms and acronyms, which only contains the specific symbols used to characterize the different ways kappa can be estimaled and no definition of the generic term kappa itself. 1040. Line 80 Please define "sigma," since this is the firsl time that lhis term is used in Term sigma is now introduced in Section 1 . 1. and defined in the report. Please also add the definition of sigma to lhe list of terms and abbreviation list acronyms, which only contains the specific symbols used lo characterize the different tvoes of standard deviations and no definition of the aeneric term sigma itself. 1041. Line 109 Please consider replacing the phrase '"suites of models'* with done "representative suite of models** here and elsewhere in the report to conform with terminology used in "Atkinson, G.M., Bommer, J.J., and Abrahamson, N.A. (2014). Alternative approaches to modeling epistemic uncertainty in ground motions in probabilistic seismic-hazard analysis, Seismo/oaical Research Letters, Vol. 86, DD. 1141-1144." CHAPTER 2-Project Organization 1042. Line 52 The description of the workshops is incomplete and does not list all of Sentence modifies to add the qualifier "among other purposes. the purposes of the workshops. Please qualify the sentence to indicate the Workshops ..... ** that this is only one of the purposes of the workshops or expand it to list all of the purposes. 1043. Line 53 Since this is the first time that peer review is mentioned in the report, PPRP is already introduced in Section 2.1.2, and is already please introduce the peer review panel and the acronym PPRP. Please included in the list of acronyms also add the definition of PPRP to the list of terms and acronyms. 1044. Line 75 The use of the phrase "Appendix A of Appendix A" is awkward. Please Done in Chapter 2, pending in Appendix A consider calling the appendix of an appendix something different in order to avoid confusion (e.g., "'annex"). 1045. Line 81 Please correct the name of the power plant, i.e., "Saint Onofre" should aone be San Onofre " 1046. Line 146 Please correct the grammar in 1his passage, e.g., "preliminary estimate of the kappa sensitivity ... " 1047. Line 157 The large magnitude earthquakes in California cited here appear lo be "and Mexico" added the same events referred to elsewhere in the report as large earthquakes in California and Mexico (appropriately, since the 2010 El Mayor-Cucapah event is included). Please clarify or correct for consistency. 1048. Line 162 Please provide a reference to the PEER report that is mentioned in this Section mildly rearranged to provide the requested citation sentence. (Kishida et al.. 2014) 1049. Lines 167-171 Please provide references for the PEER projects that are referred to in NGA-Subduction effort is not referred to this paragraph. 1050. Line 187 Please reference the report or appendix where the PE&A study can be found. 1051. Line 189 Please consider replacing the word sensibly" with one that better Changed to "significantly" conveys what the writer intended to mean. 1052. Line 253 Please explain what anticipated" means in this context. Changed to "preceded" CHAPTER 3-SWUS GMC Work Plan and Key Study Tasks 1053. Line 97 Please confirm that the distance range "30-100 km" is correct and should Changed to "less than 100 km" not be "less than 100 km." 1054. Line 152 In Table 34-1. "Ken Campbell Consulting" should be "Kenneth W fixed Campbell Consulting." 1055. Line 244 Please clarify that "the second meeting" refers to the January 2014 Clarification added Special Working Meeting. 1056. Line 340 In Table 3 7-1. "Ken Campbell Consulting" should be "Kenneth W fixed Campbell Consulting." CHAPTER 4-Seismotectonic Setting 1057. Line 160 Please explain the difference between "layered faults" and "individual Definition of "layered fault" added to text faults." 1058. Lines 163-164 These lines refer to two categories, namely "the California and Mexico Entries in the table are now aligned with the text in the chapter faults (referred to as Regions 1 and 2&3 in this Report)," and "other faults (AZ,NM, NV, and Mexico)." Table 4.2-2 has rows for "CA Faults" and "AZ, NV, & Mex Faults." Do the rows of the table correspond to the two categories of faults described in the text? If so, please align the terminoloov; if not, olease clarifv 1059. Lines 172-179 The legends of Figures 4-8a and 4-Sb are not well correlated with the Clarifying text is provided in the chapter body. Also. a new set of text. For example. "NSHMP faults" are noted in the legends but are figures showing the contribution from individual faults has been defined neither there nor in the text. And the text calls attention to the added: this supports the conclusions on the distant sources dominance of distant fault sources for low frequency at 10*4 AFE, but the being the main contributors at low frequency figures do not identify the curves associated with "distant fault sources." Please reconcile the fiaure leaends and the text. 1060. Line 289 In Figure 4-8a. please explain the meaning of "coarse" and "fine" areal The meaning has been introduced in Section 4.2.3 and is not sources. repeated in the figure caption 1061. Line 293 In Figure 4-8b, please explain the meaning of "coarse" and "fine" areal The meaning has been introduced in Section 4.2.3 and is not sources. repeated in the figure caption 1062. Tables 4.1-4, 4.2-1, Please identify the pertinent site (Le., DCPP or PVNGS) in the title of done 4.2-2 each of these tables. 1063. Figure 4-1 The two line colors for the SAF are not well distinguished in the figure. done Please consider making improvements lo remedy this. 1064. Figure 4-2 Please identify the site (DCPP) in the figure caption. done 1065. Figure 4-6 The arrow for the Cerro Prieto fault points to the Imperial fault (CPF is done the next bold red line to the SW). Please correct this. CHAPTER 5-Ground Motion Databases and Candidate Models 1066. General Two references for Kishida et al.. 2014a and 2014b. appear in the Fixed. Now the two separate references are appointed as 2014a reference list. However. many of the citations in this chapter refer only to and 2014b Kishida et al. (2014) without distinguishing 2014a from 2014b. Please check and correct this omission. 1067. General The figure numbering scheme seems lo be inconsistent in this chapter. Done. Now the figure and table numbers renect the two section For example, Figure 5.2.2-2 is called in Section 5.2.2.1, indicating the level convention that only the chapter number and first two section levels prefix the sequence number. But a Figure 5.2.3.4-1 is called in Section 5 2 3 4. so in that case the chapter number and all three section levels prefix the sequence number. There are some other anomalies as well. Please check carefully and ensure that numbering is done consistently throuahout. 1068. Line 11 Use of the term "proponent models" is confusing, especially given that Word "proponent" removed the report is written in third person with no identified authors. The term is usually reserved for describing a model or method proposed by a Proponent Expert (PE). If this is not the meaning of the term in this context or in similar contexts elsewhere in the report, please consider using another term to describe the models or identify who the proponents are (e.g .. "Tl Team proponent models") when the term is used. 1069. Line 27 The intended meaning of the sentence is ambiguous. If the intent is to done say that the Wells earthquake was in the southern Basin and Range, please review for accuracy (e.g., was it in the northern or southern Basin and Range?). If the intent is that the Wells earthquake provides control for a normal faultina earthauake, if one should occur in the Southern Basin and Range. please clarify and correct, as needed. 1070. Line 31 Since this is the first time that the term "PSA" is used in the report, done please define it. 1071. Line 47 Please add that the bottom frames also show the number of recordings Verbiage added to address that the frame addressed the per site class. number of recordings per site conditions (VS30) 1072. Line 85 There is no evidence in Figure 5.1.2-1 of "Station Z14A, shown by the Sentence restructured and reference to star removed (it was old open star". Please clarify. text associated to a previous version of the figure) 1073. Line 87 Please complete the citation of "Kishida (i.e .* Kishida et al. 2014a or done 2014b?). 1074. Line 158 Please correct the figure number on this line. which should be Figure done 5.1.5-1. 1075. Lines 173-174 The spelling of the fault names differs between the text and Figure 5.1.5-done 2 ("ltozawa" in the figure becomes "ldozawa" in the text, and "Yunodake" in the figure becomes "Yunotake" in the text). Please edit for consistencv. 1076. Lines 175-176 The total moment given here and attributed to personal communication is inconsistent with the moment magnitude of 6.7 given for this event on Line 164 (the sum of the moments on Line 175 imply M 6.56). Please resolve the inconsistency. In doing so, please consider whether it would be appropriate to cite published moment estimates (e.g., Tanaka et al., 2014, report a moment consistent with M 6.7 and approximately equally partitioned between the two faults) instead of those reported from oersonal communication. 1077. Line 202 Please supply the missing Table 5. 1. 7-1. The correct citation is the table 5. 1.2-2 1078. Line 209 The symbols referring to the different types of kappa used in this sentence are slightly different from those listed in the terms and acronyms. Please use a consistent set of symbols for kappa throughout the report and appendices. 1079. Line 216 K,, is undefined at this point in the text. Please correct this. 1080. Line 223 Please consider whether a more appropriate characterization than "upper bound can be used here (e.g .* is that categorical statement even consistent with the one standard deviation ranges cited for the other methods?). 1081. Line 228 Please include a reference to a publication describing the SCEC BBP Reference added (e.g., the paper by Maechling et al. in the Jan/Feb 2015 SRL may be aooropriate ). 1082. Line 242 Please consider citing the published paper by Dreger et al. (2015) in the done Jan/Feb 2015 SRL 1083. Lines 264-266 It is appropriate for the Tl Team to rely on the SCEC Validation Review done Panel for the technical analysis of the simulations. and to rely upon the judgment of that panel to determine which methods met the acceptance criteria established in that review. However, 1he Tl T earn itself needs to justify that meeting those acceptance criteria makes the methods suitable for the specific purposes for which the simulations are to be employed. Those purposes are stated on Lines 227-233. Please augment the summary statement on Lines 264-266 by explaining how meeting the SCEC review panel's acceptance criteria makes the simulation methods suitable for addressing the problems laid out on Lines 8-14.

1084. Lines 306-315 This passage needs rewriting because: (1) the BSL model is not done identified as GIL7 on Line 309, but seems to be the same as what is called GIL7 in the legend of Figure 5.2.2-1 and then on Line 312; and (2) the passage is repetitive (e.g., the verbiage about routine estimation of moment tensors on Line 309 is repeated on Line 314-315; the basis of the GIL? model in broadband waveform modeling is slated repetitively on Line 308 and then on Line 314). 1085. Line 322 "Frequency wave-number" is written differently on this line than it was on done Lines 304 and 3 t 1 ("frequency-wave number"). Please review the hyphenation convention and apply one consistently (note also that both "wave number" and "wavenumber" are in common use, so the easier-to-read form "freauencv-wavenumber" is also an ootionl. 1086. Line 361, 364 "Area" is used to signify rupture area in Equation 5.2.3-1, but "A" is done defined as rupture area on Line 364. Please edit for consistency. 1087. Lines 37 4-375 Please indicate whether this statement is an assumption or is based on an evaluation of data, models, etc., by the Tl Team. Under internal revision 1088. Line 383 Please correct the figure number. It is called out as Figure 5.3.2.1-1 on done this line, but the figure itself is labeled as Figure 5.2.3.1-1. Moreover. the numbering scheme used elsewhere in the report appears to call it Figure 5 2 3-t. since it occurs in a subsection of Section 5.2 3 (e.g .. by analogy with the fact that Figures 5.2.2-1 and 5.2.2-2 occur in Section 5.2.2. t). 1089. Line 392 The figure number 5.2.3.2-1 is inconsistent with the fact that it is the ok second figure in the subsection. Please check the figure numbering convention and make ii consistent with the rest of the chapter and reoort. 1090. Line 396 Please indicate that CB14 also used the functional form of the hanging-wall term developed by Donahue and Abrahamson (2014). 1091. Line 411 Please consider replacing "we" (first person) with third-person to be done consistent with the remainder of the report. 1092. Lines 427. 431. and The figure citations do not correspond to the figure numbering. Please 433 check the figure numbering against the figure citations and correct as needed. 1093. Line 452, 458 The table called Table 5.1.1-2 on this line appears to be the table corrected labeled Table 5.1-2 (and called by those numbers elsewhere in the reoortl. Please correct here and in subseauent occurrences. 1094. Line 464, 475, 481 Line 464 gives the distance criterion for NGA-W2_DC-MED as abs(Rx)<70km. whereas the lines 475 and 481 give it as R<70 km, which is more restrictive. Please clarify how the various distance metrics are used together to screen records for NGA-W2 DC-MED. 1095. Line 492 Please quantify what "similar enough" means in regards to the value of Vs3-0 (e.g., in terms of the percent difference in site-amplification factors). 1096. Line 506 Previously, Akkar et al. (2014c) was cited as the database reference. Clarification added -it is a subset of the dataset used to derive Please check whether the citation given on this line is correct in the the ASB14 model, which in tum is a subset of the RESORCE present context. database (Akkar et al 2014 cl 1097. Lines 508 and 517 The criterion abs(Rx)<70 km leaves the total distance unconstrained. Please provide a complete statement of the distance selection criterion. 1098. Line 548 Please consider whether this might be a good place to introduce the done symbol 41> ** , so that it will be defined prior to its use on Line 553. 1099. Line 558 "Disaggregation" is used on this line, whereas "deaggregation" is used done elsewhere in the report. Please edit for consistency. 1100. Lines 565-572 The selection criteria (distance, magnitude, number of recordings per Sentence added event and site) do not seem to be given. Please check and correct if necessarv. 1101. Line 566 "NGA-W2" is "NGA-West2" elsewhere. Please edit for consistency. We found one case saying "-west2 which has been corrected to "-West2" 1102. Line 579 Please check whether "for use in" should be "is used in". As is, the Changed to "to be used in" sentence lacks a verb. 1103. Line 585 Please add the missing parenthesis closure. ok 1104. Lines 592-593 Please indicate whether the 3 events per station requirement was also applied. 1105. Line 601 Section 5.4.1 does not contain the discussion of the Idriss 2014 model Section 5.4.1 has now a small sentence on how Idriss (2014) that is referenced here ("As noted in Section 5.4.1"), nor does there treats the residuals appear to be any prior reference to the Idriss model in the chapter. Please make the necessary corrections. 1106. Line 610 Please replace "200-30 km" with "30-200 km." done 1107. Lines 614-615 CB 14 used mixed-effects regression to derive the anelastic attenuation tenn from data with RR11P > 80 km, but allowed the source terms to vary from those for RRuP < 80 km. Although this does not necessarily impact the decision not to use CB14, the descrip1ion of what CB14 did should be correctly stated in the text. 1108. Line 619 Please indicate what range that "1his magnitude-distance range" refers to. 1109. Lines 619 and 626 Line 619 has the statement that 'the global dataset in this magnitude Second sentence has been removed because added confusion and distance range consists of 264-415 recordings from 4 to 23 without additional information earthquakes." Line 625 states "Within this magnitude and distance range, the global dataset contains four earthquakes and 280 records. Please clarify why these statements are not contradictory. 1110. Line 627 The cited figures do not exist Please add them. Figures are there 1111. Line 669-670 Please correct the figure references (they shou Id be to Figures 5 5 1-1 done and 5.5.1-2). 1112. Line 673 Please correct the figure reference (it should be to Figure 5 51-3). done 1113. Line 683 Please correct the table reference (the intended reference appears to be done to Table 5 51-1). 1114. Line 724 Please clarify why specific scenarios had to be specified. given that kappa is not being explicitly modeled as a source effect. 1115. Line 725 Please explain why only footwall scenarios were used. 1116. Line 727 Please consider rewording the reference to "Q attenuation." to avoid the implication that 1he kappa effect is necessarily physically distinct from effects ordinarily parameterized in terms of a. Isn't the point that the kappa parameter (or at least Kc) is intended to capture attenuation effects that are so localized that in a practical sense they are better parameterized as site terms than as pa1h-dependent attenuation tenns, and that therefore isolation of kappa effects requires short-distance scenarios? 1117. Line 730 Please be more specific about which profile was used. Is ii one of those in Figure 2.6 of Kamai et al. (one is listed as having Vs30 of 750 m/s, none has exactly 760 m/s )? 1118. Line 735 Figure 5.5.3-1 appears to be labeled incorrectly. Please correct this. done 1119. Line 778 Rodriguez-Marek (2013) actually developed four single-station sigma Text expanded to clarify the confusion models: one with neither M nor R dependence, one each with Mand R dependencies, respectively, and a fourth with both M and R dependence. Please clarify which three have been chosen. and why. Note also that there is a perception of ambiguity introduced by mixing "dependent" and "independent" in listing the attributes of the selected models; i.e., is the "magnitude-independent" model alluded to also R independent (in which case it would be clearer to say "magnitude and distance independent), or is there a typo such that "magnitude-dependent" is what is actually intended? If one of the figures were not missing, this ambiguity would be cleared up, but it would be better to also do so in the text. 1120. Lines 779 and 781 Please check whether the first of the three models alluded to should be Text clarified to say that is magnitude-dependent "magnitude-dependent" (rather than magnitude-independent". which would appear to be inconsistent with the figures). Alternatively, if "magnitude-independent" is correct as written, please clarify whether it is paired with a distance dependence or not. 1121. Lines 780-782 Only the R-dependent and MR-dependent models are shown. and these done are in Figures 5.6.2-3 and 5.6.2-4, respectively (not 5.6.2-4 and 5.6.2-5 as called in the text). The other model (called "magnitude-independent" in the text) is not shown. nor is there any Figure 5.6-5. Please correct this 1122. Line 789 Please cite a reference for the assertions about the small-magnitude limitations of GMPEs at short distance. 1123. Line t122 Table 5.5.1-1 indicates that the Graizer (2014) GMPE was used for the DCPP GMC model. but the Graizer GMPE is not listed as being one of the models that was used in Chapter 6. Please either correct the table or the text in Chapter 6. If this GMPE was used, please justify its use in view of the fact that it is only published as a conference paper and has not been oeer reviewed or vetted bv the laraer scientific communitv. 1124. Figure 5.1.3-1 The caption cites Akkar et al. (2014a and 2014b), whereas the text (Line Clarification added 121) cites Akkar et al. (2014c), apparently in the same context. Please check whether this difference is intentional and make a correction if aooropriate. 1125. Figures 5.2.3.4-1 and These figures are mislabeled (as 5.2.3.3-1 and 5.2.3.3-2, respectively). Fixed 5.2.3.4-2 Please correct. 1126. Figures 5.3.2-1 and Please correct these figures. In each of these figures. the second row fixed 5.3.2-2 repeats the first with a scale change, and the remaining plots (recordings per site, recordings per event, etc.) are absent. 1127. Line 1258 In Figure 5.4.1-2, please explain why there is a triangular symbol plotted at slightly over 100 km or, if this is an error, please remove the symbol. 1128. Line 1263 In Figure 5.4.1-3, please explain why there is a triangular symbol plotted at slightly over 100 km or, if this is an error, please remove the symbol. 1129. Line 1322 In Figure 5.5.1-1, please define the meaning of the solid black symbols and the color and black trend lines. 1130. Line 1326 In Figure 5.5.1-2, please define the meaning of the solid black symbols and the color and black trend lines. 1131. Figure 5.5.3-1 Please correct the figure number. It is called Figure 5.5.3-1, but labeled fixed 5.5.3-2. 1132. Figure 5.6.2-2 Please improve the figure caption by including some basic contextual information. 1133. Figure 5.6.4-1 Please add the dataset identifiers given in Lines 805-808 of the text Names added to the captions (Blea, Blea2, and ABR) to the figure caption, or else delete them from the text, as the inconsistency is confusing. CHAPTER 6-GMC Models for the Median 1134. Lines 23-24 Table 5.5.1-1 indicates that the Graizer (2014) GMPE was used for the DCPP GMC model. resulting in the use of 9 models. The text indicates that 8 models, excluding the Graizer GMPE, were used. Please correct either the table or the text. 1135. Line 105 Please hyphenate "large-distance attenuation" to resolve the otherwise fixed ambiguous meaning. 1136. Lines 209-210 Not all of the simulations show that hanging-wall effects persist down to magnitudes of 5.5 and 6.0 for all fault geometries. This suggests that there is some uncertainty in whether such effects exist. Please discuss this apparent uncertainty and justify the decision to extend hanging-wall effects to smaller magnitudes. explaining whether this uncertainty is accounted for elsewhere. 1137. Lines 256-257 Please explain why, if hanging-wall effects are geometric, the cosine term is more appropriate than the arithmetic angle to model these effects. 1138. Line 269 The statement that the hanging-wall models are "equally likely" and "normally distributed" is still confusing on its face. However, the discussion that follows clarifies this apparent contradiction vis-a-vis the use of equal probability slices of the distribution. Perhaps, a statement like "as explained below" after introducing this apparent contradiction would provide less confusion for the reader. 1139. Line 303 Figure 6.3.2-5 shows CB14 having a step-like change in its HW factor as Sentence and figure replaced Rjb approaches zero along the strike direction. Please clarify how this is consistent with the claim that CB14 allows "a smoother transition" around the rupture compared with some other models. 1140. Lines 341-343 In reviewing all of the figures comparing the HW adjustment model with the simulations, all except Figure 6.3.2-14 compare the simulations only with the central HW model. In order to show that the five HW models adequately capture the uncertainty in the simulations, please show all five HW models in all of the figures and discuss any cases in which the five models to not appear to caoture the uncertaintv. 1141. Line 363 The term "scaled-backbone approach" is never used by Atkinson et al. Sentence rephrased: "Atkinson et al. (2014) introduced the (2014). These authors do mention the concept of selecting a single concept of selecting a single "central or backbone GMPE" and "central or backbone GMPE" and scaling it up and down. but do not scaling it up and down. This concept is here referred to as the specifically call this a scaled-backbone approach. Please consider "scaled-backbone approach", which provides a method to replacing the term "scaled-backbone approach" with a simple description develop a set of.. .. of the approach instead. 1142. Line 384 The term "generated models" is used in this sentence to refer to ground Done in section. Search ongoing in the rest of the report. motion models derived from the visualization (Sammon's mapping) technique. Terms such as "large suite of models" and "representative models" were used earlier in the section to refer to similar models. The concept of using visualization techniques to produce a distribution of models that sample the full model space is difficult enough to understand without being confused further by the use of different terms to describe the same technique or products thereof. In order to avoid such confusion, please consider using a consistent and strict set of terminology to refer to these models. For example, the term "candidate models" has been generally used to describe the GMPEs that are used in conjunction with the visualization method, since this term is used elsewhere in the report to describe such models; the term "suite of models" might be used to refer to the entire set of models that are generated using the visualization technique (e.g., the 2000 common-form models); and the term "representative suite of models" might be used to refer to the final set of models that are used in the GMC logic tree (e.g., the 25 or so common-form models). This latter term is also consistent with the general term used by Atkinson et al. (2014) to describe the method of generating models that sample the model space. whether it be by simple methods (i.e., scaling up and down) or by more complex models, such as those sampled from the Sammon's map. 1143. Line 402 It is possible that this is the first time that the term "Joyner-Boore Disagree. First occurrence of "Joyner-Boore distance (R,a)" is in distance is used in the report. If so, please note that this term refers to Section 6.3 the distance metric RJa. 1144. Lines 412-4t3 Please delete "010" and replace "(fork = 7.8.9. tO)" with "(fork = 7.8,9)" Fixed now (See general comment 1040) since there is no k = 10 coefficient in the model. 1145. Line 429 Please replace "(fork = 7,8,9, 10)" with "(for k = 7,8,9)" since there is no k Fixed now (See general comment 1040) = 10 coefficient in the model 1146. Line 433 Please replace "fork= 7.8.9. 10" with "fork= 7,8,9" since there is no k = Fixed now (See general comment 1040) 10 coefficient in the model. 1147. Line 444 Please replace "fork = 7.8.9 and 1 O" with "fork = 7.8 and 9" since there Fixed now (See general comment 1040) is no k = 10 coefficient in the model. 1148. Line 449 Please justify the selection of +/-3 km to represent the uncertainty around the mean value of ZroR-1149. Lines 463-464 In order for R.1a to equal IRxl. the footwall site must be located at a source-to-site azimuth of -90 degrees (ie., perpendicular to the fault within the bounds of the ends of the rupture). Please indicate that this is the case in order to justify the given distance equalities. 1150. Lines 472 and 493 The term "total residual" is usually reserved to mean the addition of the fixed between-event and within-event residuals in the aleatory variability model. Please consider calling this the "total fitted residual" or something like that to distinouish it from the true total residual. 1151. Lines 502-5t3 The entire discussion of using candidate GMPEs and interpolated A numerical evaluation was conducted to address this question versions of the GMPEs and the generation and simplification of the and will be included in the Rev.1 Report coefficient covariance matrices is confusing to a non-statistician. For example. what exactly are the sets of weights applied to and why can the covariance matrices be simplified in the manner discussed? Please consider expanding this discussion to better explain and justify exactly what was done. 1152. Lines 506-513 Please justify how it is mathematically possible with the addition of the See above interpolated GMPE ground motions to better capture the correlations? 1153. Line 524 Please be precise about what types of "standard deviations" are plotted in Figure 6.4.3-1. 1154. Lines 536-548 This explanation needs to be set out more clearly. The sentence beginning on Line 536 states that "for the DCPP application ... the central HW branch is applied to all common-form models." The rest of the passage. although rather difficult to read, appears to indicate the following: ( 1) HW effects are omitted from the 2000 models used for the Sammon's map, (2) the central HW model is appended to those footwall models, solely for the purpose of the simplified hazard calculations used in the selection of representative common-form (footwall) models from the original 2000, and (3) randomly selected HW models (from the equal-probability set developed in Section 6.3.2) are appended to the selected representative set of footwall models, to give the final set of common-form models for application to DCPP. If this is a correct interpretation, then the last item seems to contradict the sentence from Line 536 (and if this is not a correct interoretation, some clarification is needed). Please rewrite for clarity and consistency. This paragraph would be less confusing if a strict use of terminology to identify all of the different types of models were used, as suggested in an earlier comment. Please be more specific in identifying what sel of models are being described in each case, such as candidate models (ie .. the original published GMPES). common-form models (Le .. the mean and interpreted GMPEs and presumably the 2000 or 7500 count versions as well). representative model (i.e., the common-form model that best matches the mean hazard in a given cell), and the suite of representative models (i.e., the ones that are eventually used in the logic tree) 1155. Line 552 Please be explicit as to whether this paragraph is discussing the Fixed (refers to both sites) development of representative models for both sites or just PVNGS. 1156. Line 564 Please replace **magnitudefdistance" with "magnitude-distance." fixed 1157. Line 602 Please review the appropriateness of subscript k in NGk. given that there is already a sum over k. 1158. Lines 614-615 Please justify why uncertainty in Ztor is represented by adding 3 km to Ztor and not also subtracting 3 km and why the value of 3 km was chosen to represent this uncertainty (see previous comment). 1159. Lines 616-618 Please explain why a value for Zlor is needed in the R.1s*based models A qualifier has been added saying that "only one ZrnR value is when it was not used as a term in these models. ie., how can one Ztor used lo develop geometries for compatible distance metrics" value" be used if the models do not include Ztor at all? 1160. Line 629 Please correct the spelling of the second occurrence of "PVNGS" 'ixed 1161. Line 632 Please check whether the intent of this sentence would be more clearly fixed expressed if the final clause were included inside the parentheses. 1162. Line 633 It appears from Eq. 6.4-4 that it is the contributions to the Euclidean distance squared that are weighted by the weights from Eq. 6.4-7 (not the contributions to the Euclidean distance itself, as stated). Please correct or clarify. 1163. Lines 689-690 The phrase " ... then the point that corresponds lo the position of the candidate GMPEs is selected" is confusing. Please rewrite this phrase to make its meaning clearer. 1164. Line 704 Please correct the typo, i.e .. "two week" should be **too weak." fixed 1165. Line 706 Please provide a brief statement. or reference. that describes a "Voronoi-diagram" or the section(s) of an appendix where such a reference or definition can be found 1166. Lines 719-720 Is it true that all of the models within a given Voronoi cell do not really represent the same level of probability on the ground-motion distribution? If this is true, the use of equal weights is an assumption. Please justify the use of equal weights to determine the weighted mean hazard in each cell. 1167. Line 726 Please discuss the common form model that corresponds to the highest hazard curve in Figure 6.4.4-4 and explain why it falls so far above the cluster defined bv the rest of the models in the same cell. 1168. Lines 735-736 Although the distribution of HW models is nearly uniform for the DCPP representative models. the distribution of the hazard might not be. depending on what Voronoi cells received the higher HW models (i.e., the high-hazard cells or the low-hazard cells). Please justify that the mean hazard is not biased by the random selection of HW models. 1169. Lines 762-763 Please clarify what "results" are not sensitive to the discretization size of the Voronoi cells (i.e., the weights or the hazard). It is possible that the hazard will be sensitive to the size of the cells (e.g., what if only one cell were used?). 1170. Lines 804-807 Please show an example contour plot in Chapter 6 for those readers that do not care to read Appendix H. 1171. Lines 808-809 Please show an example distribution plot in Chapter 6 for those readers that do not care to read Appendix H. 1172. Line 879 Two consecutive figures are called "6.4.5-8." Please check and fixed renumber as needed. 1173. Lines 927-928 The sentence starting with "Randomizing" appears to be unconnected to the rest of the paragraph. Please expand or rewrite this sentence to better convev is meanina. 1174. Line 929 Please see the general comment regarding the documentation of the directivity model evaluation 1175. Lines 937-939 If the standard deviation represents the variability in the hypocenter location, please explain what the median (or should it be the mean) represents (e.g., the bias?). 1176. Lines 951-953 Please justify why it is not necessary to include Ztor as a directivity parameter for those events that do not rupture to the surface (e.g., the directivity effects for M5.5-6.5 events that the GMPEs were evaluated for). 1177. Lines 962 -964 Please include sufficient details of the Tl Team's evaluations of the technical merits and limitations of the simplified directivity model in support of the decision to adopt this model for use in hazard calculations (as also reQuested in one of the Qeneral comments). 1178. Lines 965-967 Please explain the basis for the evaluation that the simplified directivity model is a reasonable approach for capturing directivity effects (e.g .. was the hazard using the CY 14 directivity model and random hypocenters compared to that using the simplified model?). 1179. Lines 981-982 Please identify which event NGA EOI D 1017 represents and why it is justified to remove this event because the event-terms of the GMPEs are not consistent. 1180. Lines 990-991 Please explain why there is a difference in plotted values between Figure 6.6.1-2 and Figure 7.4.1-6. 1181. Lines 1008-1009 There seem to be two sets of LN values being given in this section. The -0.5 and +0.1 LN units listed in the previous paragraph appear to be biases in the log PSA values, whereas, the 0.32 and 0.35 LN units given in this paragraph appear to be standard deviations. Please make the distinction between these two sets of values clear in the text. Please also be more specific about what "numbers" (the biases or the standard deviations) the Tl Team considers to be "reasonable." 1182. Lines 1015 The use of the term "proponent model" or "proponent method" is confusing, since it can be interpreted as a model or method being proposed by a Proponent Expert (PE). If these models and methods are proposed by the Tl Team, please replace "proponent with "Tl Team" in this line and elsewhere in Section 6.7 where the term is used. 1183. Line 1036 Please delete the phrase "with similar rake, dip, width," which is incorrect based on the contradictory and apparently correct description given on Line 1039. 1184. Line 1039 Please note that this statement appears to contradict the phrase on Line 1036. which has been interpreted to be a typo in a previous comment. 1185. Lines 1064-1065 The sentence "The ground motions from the 2011 Fukushima-Hamadori earthquake are evalua1ed using the SRSS method in Section 9.1.5.2." appears to be disconnected from the sen1ences before and after it. It is also ambiguous what the "Therefore ... " at the beginning of the next sentence is referring to. Please rewrite these sentences to better convey their intended meanina. 1186. Line 1076 Please explain which complex rupture "Complex Scenario 18" represents. 1187. Line 1096 Please explain which splay rupture Splay Scenario 1 C" represents. 1188. Line 1300 Please confirm whether "Model A" should be included in the title to Table 6 4-2. 1189. Line 1343 Please confirm that the CB14 GMPE is plotted correctly in the lower plot (M6.6, SS, PGA). 1190. Line 1354 Please confirm that the GMPEs are plotted correctly in 1his plot. For example, CB14 appears to have a hinge or kink at M7, but its magnitude scaling term does not. 1191. Line 1359 Please identify the models listed in the legend to Figure 6.2.3-1 by their correct acronyms (i.e .. ASK14 instead of ASK). 1192. Line 1380 Please identify the models listed in the legend to Figure 6.3.1-2 by their correct acronyms (i.e .. ASK14 instead of ASK). 1193. Line 1386 Please identify the models listed in the legend to Figure 6.3.2-1 by their correct acronyms (i.e., ASK14 instead of ASK2014). Please also justify in the text why it is acceptable for the predictions from the proposed HW models to not encompass the predictions from all of the GMPEs. 1194. Line 1391 Please identify the models listed in the legend to Figure 6.3.2-2 by their correct acronyms (i.e .. ASK14 instead of ASK2014). Please also justify in the text why it is acceptable for the predictions from the proposed HW models to not encompass the predictions from all of the GMPEs. 1195. Line 1396 Please identify the models listed in the legend to Figure 6.3.2-3 by their correct acronyms (i.e .. ASK14 instead of ASK2014). Please also justify in the text why it is acceptable for the predictions from the proposed HW models to not encompass the predictions from all of the GMPEs. 1196. Line 1401 Please identify the models listed in the legend to Figure 6.3.2-4 by their correct acronyms (i.e., ASK14 instead of ASK2014). Please also justify in the text why it is acceptable for the predictions from the proposed HW models to not encompass the predictions from all of the GMPEs. 1197. Line 1406 Please identify the models listed in the legend to Figure 6.3.2-5 by their correct acronyms (i.e .. ASK14 instead of ASK2014). 1198. Line 1409 Please identify the models listed in the legend to Figure 6.3.2-6 by their correct acronyms (i.e .. ASK14 instead of ASK2014). 1199. Line 1432 In Figure 6.3.2-11, please justify in the text why it is acceptable for the predictions from the HW models to not encompass all of the predictions from the simulations 1200. Line 1438 In Figure 6.3.2-12, please justify in the text why it is acceptable for the predictions from the HW models lo not encompass all of the predictions from 1he simulations. 1201. Line 1444 In Figure 6.3.2-13, please justify in the text why it is acceptable for 1he predictions from the HW models to not encompass all of the predictions from the simulations. 1202. Line 1448 In Figure 6.3.2-14, please justify in the text why it is acceptable for the predictions from the HW models to not encompass all of the predictions from the simulations. 1203. Lines 1472 (Figure The plot for the Idriss model is labeled "114," inconsistent with "ld14" 6.4.1-4a), 1475 elsewhere in the chapter. Please modify for consistency. (Figure 6.4.1-4b), 1478 (Figure 6.4. t-Sa), and Line 1481 (Figure 6.5.1-Sb) 1204. Line 1529 In Figure 6.4.3-3, please explain the meaning of "NGAW2Pv-MED MODEL A" in the upper-left corner of the plot. 1205. Line 1552 In Figure 6.4.4-1, please explain the meaning of "NGAW2oc-MEo" in the upper-left corner of the plot. Please also explain what the different colors for the solid circles representing the GMPEs and their epistemic uncertainty refer to and what the grey circles represent. 1206. Line 1557 In Figure 6.4.4-2, please provide a legend for the color contours and explain the meaning of the grey ellipses and circles. 1207. Line 1567 In Figure 6.4.4-4, please define the axes labels and explain the meaning of "T001 DCCP4 MODELA" in the upper-right corner of the bottom plot. 1208. Line t 586 (Figure The caption states that the GMPEs are in black, but the legend indicates 6.4.5-2b) a different color. Moreover, the color assignments differ from those in Figure 6 4 5-2a Please modify for consistency between caption and leqend, and between the a and b parts of the figure 1209. Line 1623 In Figure 6.4.5-7, please justify why it is acceptable for the predictions from the proposed model to not encompass all of the predictions from the candidate GMPEs. The inference is that there is less than 5% confidence in those GMPE predictions that fall outside of the limits of the model. 1210. Line 1630 In Figure 6.4.5-8, please justify why it is acceptable for the predictions from the proposed model to not encompass all of the predictions from the candidate GMPEs. The inference is that there is less than 5% confidence in those GMPE predictions that fall outside of the limits of the model. 121 t. Line 1666 In Figure 6.5.1-3, please explain what directivity model is used to make the plot and where the epicenter andfor hypocenter is located on the fault. 1212. Figure 6.7.2-2 Please label the vertical axis and explain the meaning of the term fixed "ground motion factors" in the caption. 1213. Figure 6.7.2-3 Please identify the GMPEs associated with the respective colors, and fixed the meanings of the different styles of grey lines. and make improvements to the legibility of the figure (note also that the figure did not appear in its entirety in the supplied PDF version). Also please explain the meaning of the te1TT1 "ground motion factors" in the caption 1214. Figure 6.7.2-5 Please label the vertical axis and explain the meaning of the term fixed "ground motion factors" in the caption. 1215. Figure 6.7.2-6 Please identify the GMPEs associated with the respective colors, and fixed explain the meaning of the te1TT1 "ground motion factors in the caption CHAPTER 7-GMC Models for the Sigma: Overview and Methodology 1216. Lines 8-9 Please note that by the sigma terminology of Al Atik et al (2010) "single-Notation changed throughout the report and appendices station within-event" standard deviation should be "single-site within-(pending on Chapter 5) event" standard deviation. Please consider consistently using the terminoloav of Al Atik et al. (2010). 1217. Line 74 Please consider assigning the Zhao et al. (2006) model the acronym done used in Chapter 6 (i.e., ZH06) as shorthand in the remainder of the chapter. 1218. Line 84 Please add the missing words in this sentence (which currently reads ..to smooth" added before .. through" "and chose through the"). 1219. Line 87 Please consider revising "smooth" to "constant." "Smooth changed with "period-independent 1220. Line 155 Please consider using a different word than "proponent" on this line and Proponent changed to candidate" elsewhere in the chapter to explain the different Tau and Phi models so as not to confuse them with models that have been proposed by Proponent Experts (PEs). 1221. Line t77 Please rewrite the sentence beginning with "The mean 1 values .. " to Sentence is modified now (see answer to comment 197 better convey its meaning. The second half of this sentence appears to be incomplete. 1222. Line 183 Please correct the figure citation, which should be to Figures 7.2.3-2 and nxea 7 2 3-3 (not 7.2.3-3 and 7.2.3-3"). 1223. Line t91 Please replace the term "proponent" with the term "candidate" to be Done, see comment 155 consistent with terminology used elsewhere in the report. 1224. Line t95 Please replace the term "proponent" with the term "candidate" to be Done, see comment 155 consistent with terminology used elsewhere in the report. 1225. Line t97 Please rewrite the final sentence of the paragraph to clarify its meaning , (ie .. a "value" cannot be similar to a "model," so it is not clear what point Sentence rewritten as "The standard deviation of r was fitted the sentence is trying to convey). to a constant, period-independent function. The period-independent constant estimate is similar to the central model" 1226. Line 202 Please change Ci>6 to u,. done 1227. Line 207 Please replace the term "proponent" with the term "candidate" to be Done, see comment 155 consistent with terminology used elsewhere in the report. 1228. Line 232 Please describe the type of distribution used in the simulation. 1229. Line 269 Please indicate whether "Dawood et al. (2015 )" should be replaced with The correct citation is (2014) and is already included in the "Dawood et al., 2014 -in press" and, if not, please provide the reference reference list. The notation in press" has been removed from to the former. the text 1230. Lines 271-275 This paragraph appears to be contradictory and the Tl Team decision to use a magnitude-independent Phi_ ss is not well supported by the first sentence in the paragraph and the results in Figures 7.3.2-1. Please expand this paragraph to better discuss and justify the decision to use a maanitude-independent model for Phi ss. 1231. Line 273 Please correct the inconsistency between the phrase shown . . . for fixed four spectral periods and the list "(PGA, 0.1,0.5, 1.0,3.0 sec)," which (like the figure itself) includes five periods (PGA in addition to the four given spectral periods) 1232. Line 276 Please explain why the Phi_ss values of the GLOBAL datasets for each The reasons are described in Chapter 5. The Lin et al. dataset in GMPE are only shown for five periods in the figures and indicate, if only our possession had only those five periods. five values were used in the analysis, why Phi_ss values for the other oeriods are not used. 1233. Line 320 Please describe how 0.12 was derived. It is explained in Section 7.3.1. A cross reference has been added 1234. Line 388 Please avoid the use of the first person .. us." Verbiage changed to "makes it possible" 1235. Line 396 The statement that the between-event residuals were provided by the Sentence mildly modified to clarify the difference in the approach NGA-West2 developers is contradictory to the statement on Lines 404-between PhiSS (NGA residuals) and PhiSP-R(new residuals 405 that the Tl Team calculated the residuals. Please rewrite the text to from data recorded at Arizona stations not included in NGA-remove this contradiction. West2l 1236. Line 404 Please avoid the use of the first person "we." Since the use of first done person has appeared several times in this chapter, please search the entire chapter for other uses of first person and convert them to third person. 1237. Line 407 This statement is confusing and again suggests that the between-event See answer to 396 residuals provided by the developers are perhaps being used Please consider rewriting or expanding this entire section to make the process of developing the LD single-path standard deviations less confusing. 1238. Line 415 Please change 0W1; to fiW,,, Tl Team to evaluate if the formula is correct or not 1239. Line 730 In the Figure 7.2.4-4 caption, please consider replacing the word done "proponent" with "candidate" to be consistent with how these models are referred to elsewhere in the report. 1240. Line 744 In the Figure 7.2.5-1 caption, please consider replacing the word done "proponent" with "candidate" to be consistent with how these models are referred to elsewhere in the report. 1241. Line 469 Please explain what is the first issue. Verbiage modified to **An issue associated to" 1242. Line 784 In Figure 7.3.2-3, please consider showing the periods with average "no-Lin et al. Data" to show that these values are also bracketed by the low and hiah proposed values. 1243. Line 812 In the Figure 7.3.3-1a caption. please describe what the black solid and dashed lines represent. Also, in this and many other figures there are error bars on the symbols, but no mention of them in the legend or the caption. Please define the meaning of the error bars in this and other figures in this chapter and for similar figures elsewhere in the report where they might appear. 1244. Line 821 In the Figure 7.3.3-1 b caption. please describe what the black solid and dashed lines represent. 1245. Line 898 In Figure 7.4.2-1, this figure clearly demonstrates that the assumption An expanded discussion on lack of data to derive Phi_SP-R that the standard deviation is constant at low and high periods is totally above 2 seconds has been added unsupported by the data (note that the values at 0.2 sec were not used because of reliability issues). Please further justify in the text why it is Answer lo second part of the question is pending appropriate to extrapolate the first and last values as constant values to lower and higher periods and why the uncertainly should not become laroer at low and hiah periods oiven this added uncertaintv. CHAPTER 8-Median GMC Models: DCPP Sources 1246. Section 8.2.2, There does not appear to be a reference to Figure 8.2-3 Please check Fixed, now is quoted in Section 8.2.2 general comment and add a reference to this figure if one is missing. 1247. Lines 60-61 Please explain the bases for the values used to define the three branches and their weights included in the second node of Figure 8.2-3. 1248. Line 100 This is not necessarily true for the Akkar et al. (2014a,b) and Bindi et al. (2014a,b) GMPEs that were developed using subsets of the RESORCE database and with al least some interaction between them under the auspices of the SIGMA project. Please clarify this statement. 1249. Line 125 Please add the missing word "models" after "common-form". Fixed ("models" added) 1250. Line 167 Please improve clarity by adding a sentence break after the word Fixed "model." 1251. Lines 293-295 Please reference where in the report the evaluation of ld14 was done to determine that it was unreliable for RRuP < 3 km at large magnitudes. 1252. Line 302 Please indicate what models are being compared in Figure 8.4-8. The discussion references both the common-form models and the candidate GMPEs and it is not clear which is being referred to when not explicitly stated in the text 1253. Line 310 Contrary to this sentence, curves corresponding to the epistemic uncertainty are not included in Figure 8.4-9. Please add the curves or modifv this sentence to remove reference to eoistemic uncertaintv. 1254. Line 355 Please provide evaluations or provide a cross reference in support of the conclusion that "differences in the magnitude and distance scaling will also imoact the ranae of the hazard." 1255. Lines 360-361 Please explain what will need to be done if in the future the hazard model is changed. For example, will an evaluation of the GMC model need to be redone because its validity was based, in part, on the hazard calculated from a specific hazard model (i.e., hazard-calibrated)? If that is the case, it is important that such a caveat be clearly communicated in the report. Please note that there are other instances in this and other chapters where hazard was invoked as demonstrating that the range in the models is adequate, which should also be included as part of this comment. 1256. Lines 367-370 Please explain why the versions of the candidate GMPEs with added epistemic uncertainty are not considered in the comparison. 1257. Line 388 Figure 8.4-7 is missing or skipped over. Please correct this oversight. fixed 1258. Figure 8.2-2 Please correct the weight for "Sim_DC-MED," (i.e., shouldn't it be 0.25?). fixed 1259. Line 522 In Figure 8.4-1, please provide labels for the color legend bars and define what the light grey ellipses and points represent. 1260. Line 533 In Figure 8.4-2, please provide labels for the color legend bars and define what the light grey ellipses and points represent. 1261. Line 547 In Figure 8.4-3, please explain what DCPP Model A is, given that there appears to be only one DCPP model. 1262. Line 569 In Figure 8.4-6, there does not appear to be any "dashed black" lines. Please revise the caption to refer to the actual color scheme used in the fiaure. 1263. Line 580 In Figure 8.4-8, there does not appear to be any "dashed black" lines. Please revise the caption to refer to the actual color scheme used in the fiaure. 1264. Line 594 In Figure 8.4-9, there does not appear to be any "dashed black" lines. Please revise the caption to refer to the actual color scheme used in the fiaure. 1265. Line 645 In the Figure 8.4-14 caption, please describe what models the phrase "individual models" refer to. 1266. Line 651 In the Figure 8.4-15 caption, please describe what models the phrase "individual models" refer to. 1267. Line 656 In the Figure 8.4-16 legend, please refer to the various models by the acronyms used throughout the report (e.g., ASK14 instead of ASK). 1268. Line 662 In the Figure 8.4-17 legend, please refer to the various models by the acronyms used throughout the report (e.g., ASK14 instead of ASK). 1269. Line 665 In Figure 8.4-18, please define what the light grey lines represent in the legend or the caption. 1270. Line 670 In Figure 8.4-19, please define what the light grey lines represent in the legend or the caption. CHAPTER 9-Median GMC Models: PVNGS Sources 1271. Line 38 Please follow the standard practice of numbering figures in the order in The instance seems fixed, needs second check which they are first called in the text, which is not the case with the figure called on this line. 1272. Line 54 Chapter 6 of this report and the report on the SSC model use the term fixed "virtual fault", rather then "pseudo fault." Please revise for consistency with those other usages. 1273. Lines 74-75 The Akkar et al. (2014a,b) and Bindi et al. (2014a,b) GMPEs were developed using subsets of the RESORCE strong-motion database under the auspices of the SIGMA project. Please indicate that these two models are likely correlated. although perhaps not to the extent of the NGA-West2 models. Please also note that this is not an issue. since epistemic uncertainty was applied to these models as well as to the NGA-West2 models. 1274. Line 108 Please specify the type of "residual" (i.e., between-event). 1275. Lines 173-174 The sentence beginning "The limitation ... " is confusing. Please reword it or expand it to make its meaning clearer. 1276. Line 187 Please make it clear which mechanism each of the weights refers to. 1277. Line 256 Please correct the figure reference; the reference to Figure 9 .1-10 should actually be to Figure 9.1-9. 1278. Line 371 Please correct the figure reference on this line (it should be 9.1-19). The instance seems fixed, needs second check 1279. Lines 475-476 Please indicate where the technical justification and bases for these statistical weights are given (i.e., Appendix P). 1280. Lines 478-481 The stated justification seems weak; there are few recordings at 200 to 400km distance range in the ground-motion database. On the other hand. it would appear that there is no need to consider directivity because its effect, as modeled in CY14, is zero at such large distances. Please revise to clarifv the iustification for the Tl Team's iudament. 1281. Line 545 In the heading of the last column in Table 9.1-1, please replace the term "SFO" with "SOF' to represent style of faulting. 1282. Line 557 In Figure 9.1-2a, please label the color legend bars and describe what the light grey ellipses and circles are on the plots. 1283. Line 567 In Figure 9.1-2b, please label the color legend bars and describe what the light grey ellipses and circles are on the plots. 1284. Line 577 In Figure 9.1-3a, please label the color legend bars and describe what the light grey ellipses and circles are on the plots. 1285. Line 587 Figure 91-3b, please label the color legend bars and describe what the ligh1 grey ellipses and circles are on the plots. 1286. Line 607 Please provide a specific reference 1o "Akkar et al." 1287. Line 637 In Figure 9.1-8, the plots do not appear to have any "dashed black" lines. Please revise the text to better describe the lines. 1288. Line 645 In Figure 9.1-9, the plots do not appear to have any "dashed black" lines. Please revise the text to better describe the lines. 1289. Line 653 In Figure 9.1-10, the plots do not appear to have any "dashed black" lines. Please revise the text to better describe the lines. 1290. Line 661 In Figure 9.1-11, the plots do not appear to have any dashed black" lines. Please revise the text to better describe the lines. Please also further justify in the text why it is acceptable for some of the predictions from the GMPEs to fall outside of the range of the representative models at some periods. Note the concern in previous comments of using only the hazard distribution alone to justify the range in the representative suite of models. 1291. Line 709 In the Figure 9.1-13 caption, please describe what is meant by "individual models," and consider making changes such that the upper and lower parts of the fiaure have the same vertical scale. 1292. Line 714 In the Figure 9.1-14 caption. please describe what is meant by individual models. 1293. Line 718 In the Figure 9.1-15 caption. please describe what is meant by individual models. 1294. Line 724 In the Figure 9.1-16 caption. please describe what is meant by individual models. 1295. Line 729 In the Figure 9.1-17a caption, please describe what is meant by selected models." Please consider using a consistent set of terminology for the different types of models that are described throughout the report to make it less confusing to the reader. Please also use a consistent set of acronvms in the leaend Ce.a, ASK14 instead of ASKJ. 1296. Line 738 In the Figure 9.1-17b caption, please describe what is meant by "selected models " Please also use a consistent set of acronyms in the legend (e.g., ASK14 instead of ASK). 1297. Line 742 In the Figure 9.1-18a caption, please describe what is meant by "selected models." Please also use a consistent set of acronyms in the legend (e.g., ASK14 instead of ASK). 1298. Line 748 In the Figure 9.1-18b caption, please describe what is meant by "selected models." Please also use a consistent set of acronyms in the legend (e.g., ASK14 instead of ASK). 1299. Line 759 In Figure 9.1-19, please use a consistent set of acronyms in the legend (e.g., ASK14 instead of ASK). 1300. Figure 9.2-1 Please correct the abbreviation for the Idriss (2014) model to be fixed consistent with usage elsewhere in the report. CHAPTER 10--.. Model Logic Tree for both DCPP and PVNGS 1301. Lines 25-26 Please also mention that the standard deviations of ASB14 and Bi14 are independent of magnitude. which was an important property of the models that the Tl Team used to reiect them. 1302. Line 38 Although the use of the term "proponent" in this context is technically fixed correct, it is inconsistent with the term "candidate" used throughout the report to identify such proponent models. Please consider replacing proponent" with candidate" lo be consislenl wilh the descriplion of such models throughout the report 1303. Line 47 Please add the term "scaled" before "Chi-square distribulion." fixed 1304. Lines 51-53 The three-point approximation scheme (as described in Appendix P) applies (0.2, 0.6, 0 2) weighs to the (5th, SOth, 95th) percentiles. Please explain the appropriateness (or point to a place where such explanation was given) of giving a 0.6 weight to the central branch representing the mean (which may not be the SO"' percentile of a Chi-square distribution). CHAPTER Model Logic Tree: DCPP 1305. Line 27 Please clarify if interpolation and extrapolation were also needed for the Done. The issues does not exist for the California data California-only data subset, which includes data at the full set of spectral oeriods. 1306. Line 53 Statistical evaluation of the standard error of ?ss was not given in Reference to Appendix P is now removed Appendix P. Please verify and correct the cross reference as needed. 1307. Lines 53-58 Please refine this paragraph to give a clear and accurate summary of the approach described in Section 7.3.1. 1308. Line 64 Please qualify the term "correlated" in a way that is similar to Lines 4-5 done of Chapter t2. 1309. Line 71 Please consider revising the term "intra-event" to "within-event" to be Done throughout the chapter consistent with the terminology generally used throughout the report. 1310. Lines 78-79 and 88-Please define the level of significance for the presumed departure from 89 normality. It might be obvious to the Tl Team, but not necessarily to the reader, that a point falling outside the 95% confidence interval can be considered to depart from normality at the 5% level of significance. Besides, others might consider "significant" to be at the 10% level of sianificance 131 t. Line t05 Please be specific whether the same weights of the mixture models that were found to be appropriate for CY14 are "similar" or the "same" as found for ASK14. 1312. Lines 108-112 Please provide a context for this paragraph. 1313. Line 127 Please insert a space after ok 1314. Line 133 Please consider revising the term "intra-event" to "within-event" to be Done (See reply to 71) consistent with the terminology used throughout the report. 1315. Line 188 In the Figure 1 t-2 caption, please consider revising the term "intra-done event" to "within-event" to be consistent with the terminology used throughout the report and define the meaning of the term "normalized." Please also define the solid and dashed red curves. In addition, note that panel b) is stated as being for T=2 sec, but the y-axis label indicates it is for T=0.5 sec. Please correct this inconsistencv. 1316. Line t91 In the Figure 1 t-3 caption. please describe what type of "residuals" are done referred to in this figure. Please also define the solid and dashed red curves. 1317. Line t94 In the Figure 1 t-4 caption. please describe what type of "residuals" are referred to in this figure. Please also define the solid and dashed red curves and provide the missing red curves on the right plot. 1318. Line 201 In Figure t 1-5, both of these plots appear to be incomplete and the left plot is not consistent with the right plot. Please correct these plots to be consistent with other similar plots in the chapter. 1319. Line 212 In Figure 11-6, both of these plots appear to be incomplete and the left plot is not consistent with the right plot. Please correct these plots to be consistent with other similar plots in the chapter. 1320. Line 218 In Figure 11-7. both of these plots appear to be incomplete and the left plot is not consistent with the right plot. Please correct these plots to be consistent with other similar plots in the chapter. CHAPTER 12-<j> Models Logic Tree: PVNGS 1321. Lines 3-5 The first paragraph appears to be awkwardly placed. Please consider Paragraph moved to second position. placing this paragraph in a more appropriate place in the chapter. 1322. Line 45 Please remove the reference to DCPP, since this chapter addresses the done Phi model for PVNGS 1323. Line 69 Please correct "biased-corrected" to "bias-corrected." fixed 1324. Line 90 Lines 486 and 487 on Page 7-16: CV=0.17 of (h*. was based on the variability and the mean of estimates for the four individual GMPEs. Please clarify or correct the statement "based on sample size" in the case of 1325. Line 146 Please replace "02 with "0.2. fixed CHAPTER 13-Total Sigma Model 1326. General The use of the term "total sigma" instead of the more accurate "total The term is intentionally used generically as two types of total single-site sigma" tends to neglect the fact that only a single-site sigma sigma values are in fact generated, one for the single station model was adopted. Please consider replacing the term "total sigma" sigma and one for the similar path to a region. These are with "total single-site sigma" to emphasize this point. indicated by the appropriate subscripts on o. No change needed 1327. Line 7 Although the Greek letter "1p" and the Greek symbol "4'"both represent q> was replaced with ¢ Phi, it is common in engineering seismology lo use the latter. which has also been used elsewhere in this report to represent Phi. Please select one of these letters/symbols to represent Phi and use it consistently throughout the report in order to avoid confusion. 1328. Line 10 Eq (13-1) is very generic and does not represent the actual aleatory The equation is intentionally generic as described in the variability models that are proposed. Please consider replacing this subsequent paragraphs. (see response to 1 334) equation with two equations: one that represents the total single-site sigma without path terms and one that represents the total single-site siama with oath terms, as discussed in the text that follows the eauation. 1329. Lines 30-31 Although the use of only a total [single-site) standard deviation epistemic The person would have to construct individual models for tau logic tree is conceptually fine. it appears to prevent the ability lo test the and phi. The necessary information is provided. sensitivity of the hazard results to the individual between-event and single-site within-event epistemic uncertainty models. Since sensitivity to each type of model is provided in Chapter 14, please explain how someone else can test this sensitivity given that the final model presents only a single total [single-site) sigma model. 1330. Line 55 Please replace the term "cumulative distribution" with the more accurate term "cumulative distribution function. 1331. Line 57 Please add a sentence to explain the utility of Eq (13-3). Will add the sentence The cumulative distribution function is used to develop the discrete approximation used in the logic tree formulation to represent the uncertainty in the variance parameter 1332. Line 61 Please correct the missing factor of two in Eq ( 13-5) (this typographical fixed error is noted here just as a reminder: it has already been noted by the Tl Team). 1333. Lines 62-63 Please further describe these analyses or provide a reference where the results of these analyses can be found. 1334. Line 66 Please correct a possible typo: should oss be changed to 4';s? 1335. Line 75 Please correct a possible typo: should <l>ss be changed to ass? 1336. Line 77 Please correct the typo ("bi-linear") and add the missing word (i.e., fixed missing "to" in "leads to"). 1337. Line 79 The Tl Team responded to PPRP's Comment 175 by adding the sentence "Appendix P presents typical examples of the calculations." However, such example calculations were not given in Appendix P. Please orovide these missina calculations. 1338. Lines 89 and 90 To be consistent with the usage in the embedded table on Line 93, please consider adding subscript "SS" to symbol c;. 1339. Line 90 Please assign the embedded table a number and a title so that it can be Fixed throughout the Chapter referenced by table number if needed, and correct any subsequent table numberino as necessarv. 1340. Lines 98, 99 and too Please explain why directly computed ass at magnitudes between M 5 and M 7 at 0.1 units were not used in fitting Eq (13-8)? 1341. Lines 102-103 Please provide a reference for the statement beginning "Minimization of the difference .. " 1342. Line t18 Please check the correctness of the reference to Section 13.1: should it be Section 13.2? 1343. Line t54 Please clarify whether "the method" refers to the semivariogram analysis fixed method (i.e., the current sentence construction leaves some ambiguity). 1344. Line t60 The Tl Team presented its evaluation and decision on the modeling of the effects of spatial correlation on crss for the magnitude-independent crss model only. Please also provide discussions for the magnitude-dependent cr" models. 1345. Line 184 Please repair the typos on this line. fixed 1346. Lines 267. 270 and Please indicate in each figure which branch includes the spatial-273 correlation effect on cr". CHAPTER 14-Hazard Sensitivity 1347. Lines 7-8 It appears awkward to state that the hazard sensitivity analyses for the final GMC model was done on preliminary versions of the SSC models without providing some sort of caveat. This can be avoided by stating that it is the responsibility of the individual NPPs to conduct thorough sensitivity analyses for their individual sites and that the sensitivity results provided herein are for demonstration purposes and for purposes of makina hazard-informed decisions. 1348. Line 60 There is no mention of deaggregation in the introduction to this chapter. Please introduce this concept and discuss what it is used for in the introduction to the chapter prior to presenting the deaggregation results. 1349. Line 81 Please add the term "mean" before "hazard level" to be clear that the results represent the mean and not some other fractile (e.g., the median) hazard. Hazard is used without prefacing it by mean many times throughout the chapter. If mean is not added to all of the instances where the hazard level is mentioned, then please state that this is the case for the remainder of the chaoter in order to avoid confusion 1350. Line 88 Please consider rewriting the caption (ie., the "hazard at hazard" Captions changed. Now they read "Deaggregation juxtaposition somewhat obscures the meaning). of reference site condition (V530 of 760 m/s) hazard at mean annual. .... " 1351. Line 103 Please define the term "sensitivity case" and be as specific as possible about what figure(s) are being referenced in the discussion. 1352. Line 116 The text on this line states that HW Models 5, 11 and 21 were selected Fixed for the 0.5 Hz tornado plots, but the figure legends for the 0.5 Hz cases indicate that Models 5, 13 and 23 were used. Please check and correct as necessarv. 1353. Line t51 Although the sigma model started as separate Tau and Phi_ss models. in the end a single total single-site sigma model was used. Please acknowledge that here and describe that the individual Tau and Phi_ss models were used for purposes of the sensitivity analyses. Also describe how the user of the model can conduct a similar sensitivity analysis usina their own hazard code. 1354. Line 152 This statement implies that "Model 1" is always the central model of the representative suite of models. If there is some numbering convention for these models, please describe that convention. 1355. Line 168 It is awkward that the first sensitivity analysis appears on the fifth line of the tornado plot. Please consider here and elsewhere in the chapter discussing the sensitivity cases starting with the top line of the tornado plot and descending down the plot to make the discussion less confusina. 1356. Line 247 The terminology used here is confusing, at best. and doesn't seem to First comment fixed. have a useful purpose. The dichotomy "seismogenic sources versus Seismic source input is what gets fed into the hazard code. so the "tectonic sources" does not seem meaningful. Why are the former not tell'Tl has not been changed. simply called areal sources. since the other type -tectonic sources -are Third comment fixed also seismogenic sources? Further, in the next line, "Seismic source input" is used; what is the difference between seismic source and seismogenic source? Finally, in Line 251, "areal seismic source" is used. This paragraph needs to be rewritten with consistent. conventional tenninology. 1357. Line 266 There is some confusion as to the use of the term "Sonora Basin and We think that the qualifier at the beginning of the paragraph is Range. The SSC model uses the term "Southern Basin and Range". sufficient to state that these names are from the SSHAC L.2 Here, you seem to indicate that the "Sonora" component of this tenn is PVNGS effort. derived from the Lettis (20t3) SSHAC2 report This needs to be made clearer. and it would also help if it were made clear that this region is Needs double checking now referred to as the Southern Basin and Range, especially as the Mexican Highland Basin and Range is in Sonora, Mexico. 1358. Line 270 Baja is not the name of the Mexican State that occupies the northern hal1 We think that the qualifier at the beginning of the paragraph is of the Baja California peninsula. It is Baja California. If this term is in sufficient to state that these names are from the SSHAC L.2 reference to that used in Lettis (2013), please make that more clear by PVNGS effort. also referencing its current usage as Baja California in the SSC report Needs double checking 1359. Lines 27 4-302 Some of the faults have "fault" in their listed name. whereas others do Fixed not. Is there a reason for this. and if so. please explain. Alternatively. make them consistent. 1360. Line 401 Please describe what is meant by the term "wider tail" in this context. 1361. Line 449 Here it states that the discussion will only address the 0.5 Hz SA Fixed sensitivities. whereas in the following text, the figures addressing the 5 Hz sensitivities are also cited (Lines 462-463, 466 and 477). Please clarify. 1362. Lines 451-452 Please be as specific as possible about what figure(s) are being referenced in the discussion. Please also be more specific when describing the sensitivity cases. For example, the first sentence mentions "the first sensitivity analysis" and the second sentence mentions "these sensitivity cases," without indicating how these two descriptions are related. Since there are a lot of repetitive statements in the text describing the sensitivity analyses and/or sensitivity cases. this comment applies throughout the chapter: please make it clear what sensitivity analysis and/or case is being discussed at any given time and where that analysis and/or case can be found on the tornado plot. 1363. Line 465 Section 7.4 .1 does not include a discussion of additional epistemic uncertainty at large magnitude. Please provide the correct cross-reference. 1364. Line 468 Please add "types" between '"two" and "common form models" in order to avoid confusion. 1365. Line 506 Please clarify what "Model 1" refers to on this line. That is the same approach followed in Section 14.2.1. Model 1 is the central model in the ellipse. A qualifier has been added 1366. Line 510 Please consider replacing the term "average" with the term "central" so as not to imply that it is intended to represent the mean (average) hazard. 1367. Line 511 Figure 14.3-10a is cited on this line, but the discussion appears to refer fixed to the case shown in Figure 14.3-9. Please check and correct as aporooriate 1368. Line 517 Figure 14.3-9b is cited on this line, but the discussion appears to refer to the case shown in Figure 14-10a. Please check and correct as aooropriate. 1369. Lines 594-595 Please add "types" between "two" and "common form models" in order to avoid confusion. 1370. Lines 609 and 617 Figures 14.3 (a and b) are cited, but in Line 605, it is stated these would Fixed in both instances not be discussed further Please clarify. CHAPTER 15-Application Guidelines and Limitations 1371. Line 5 Please provide a cross reference to the adopted kappa value of 0.041 s. Reference added to Section 5.3.3 and Appendix M 1372. Lines 5-8 Please provide a cross reference to the section where evaluations are presented to support the claim that epistemic uncertainty in kappa is captured by the variation in high-frequency spectral shape within the SWUS GMC common-form models. 1373. Lines 12-14 Please give the purpose for providing a representative Vs and density profile and what they can or should be used for, or delete this discussion from the report. Without such a statement of purpose. it is ambiguous why these profiles are presented. For example, if they are provided for purposes of documenting what was used to estimate the host kappa values for the NGA-West2 GMPEs, then their discussion should be part of the appendix that discusses the host kappa value determination. If they are meant to be representative of the site response predicted by the site terms in the NGA-West2 GMPEs, that has not been shown to be the case for these GMPES and is certainly not the case for the European or Japan GMPEs, which are likely represented by totally different Vs and density profiles CHAPTER 16-References 1374. Please carefully review these references for completeness and accuracy Ongoing and for consistency with the references provided in each chapter. From: Carola DiAlessandro Sent: Monday, March 09, 201511:44 AM To: Steven Day; Kenneth Campbell; Brian Chiou; Thomas Rockwell

Subject:

FW: directivity sensitivty study

Dear PPRP,

Please find enclosed the document that shows the similarities in hazard results between the Lamprey and the CY14 approaches for directivity. We hope this document satisfies your concerns, and can be assessed by the Panel in view of the Closure Letter. We are planning to insert this document in our report, integrating the text as appropriate in the Section 6.5. Thanks, Carola Di Alessandro, Ph.D. Project Manager for the SWUS GMC SSHAC GeoPentech, Inc. 525 N. Cabrillo Park Drive, Suite 280 Santa Ana, CA 92701 Mobile: 510-491-6713 Fax: 714-796-9191 Office Phone: 714-796-9100 Emai I: ca rola_dia lessandro@geopentech.com To: John Barneich and Norm Abrahamson From: Steven Day, PPRP Chair, SWUS GMC SSHAC Project Date: September 17, 2012

Subject:

Draft Comments on the SWUS GMC Project Plan The following is the review by the Participatory Peer Review Panel (PPRP) of the draft Project Plan (draft dated August 2, 2012) for the Southwestern U.S. Ground Motion Characterization (SWUS-GMC) SSHAC Level 3 study. Overall, the Project Plan document is well prepared, explains the SSHAC Level 3 guidelines well, and provides a framework for successful implementation of those guidelines. The panel recommendations fall into two categories. First. we recommend an augmentation of the Technical Integration (TI) team to better represent the mix of technical methods to be employed. Second, we recommend additions and clarifications to make some aspects of the plan more explicit and improve its internal consistency. Technical Integration (TI) team A substantial component of the project entails evaluation of the validity and limitations of numerical simulation methods. In the current Project Plan draft, the project relies heavily on an anticipated Southern California Earthquake Center (SCEC) numerical simulation validation report as a basis for evaluation. The panel agrees that the SCEC study may provide a valuable resource for the TI team, but also believes that the Tl team needs to have its own expertise in this area if it is to undertake the comprehensive evaluation of proponent models required in the context of a SSHAC study. The Project should therefore add another member to the TI team to bring additional expertise in methods and application of numerical modeling for ground motion estimation. It is also important that the added TI team member be an experienced scientist or engineer with a well-established professional or academic reputation, in order to bring the team a more appropriate balance between experienced experts and more junior members. Additions and Clarifications 1. The draft plan includes a brief summary of the NGA-West2 GMPEs, but that summary does not include enough detail to provide understanding of all its purposes and products. It would be useful to include a short appendix that does so. 2. The Project Plan should provide for comprehensive documentation of the numerical simulation methods. That documentation should be completed and made available to the evaluation team and PPRP in advance of the assessment of the simulation results. This document should reference previously published papers to supply supporting technical description and/or analysis and should clearly note the subsequent changes to the simulation methods that were introduced prior to their application to the SWUS project.

3. (Page 4) On other projects, the terminology distinguishes the roles of "TI Team Evaluator Experts," and "TI Team Support Technical Staff' or "TI Team Resource Experts." We believe that the term "Evaluator Expert" should be used only lo describe the Tl Team members who will have ownership of the results. 4. (Page 5) A potential concern is how differences in code implementation (particularly, for complex fault geometry, such as bending and branching faults) might influence the hazard analysis results. If the three hazard analysts plan to use different hazard analysis codes, will the project address this issue (if it is not already addressed in PEER's hazard code verification project)? 5. (Page 8) The project plan should briefly describe the mechanism for storing and disseminating various documents. 6. Task 2 (page 9) gives some examples of GMPEs developed outside of PEER that may be applicable. Since PVNGS is in an extensional tectonic environment. it would be appropriate to also explicitly note one or more examples from such an environment (e.g., Italy). 7. Project plan (page 9, 3rd paragraph, line 5) indicates that both traditional ergodic sigma and single-station sigma are included in the new PEER GMPEs. This contradicts the statement in the kickoff meeting that single-station sigma will not be part of the new GMPEs. If the latter is correct, this should be corrected in the project plan document. 8. Several other non-PEER tasks (page 9) were mentioned in the kickoff meeting, and, if these are to be part of the SWUS GMC project, there should be some discussion of these tasks in the plan. 9. The Project Plan should include a discussion of the contingency plan for the possibility that SCEC is unable to finish its validation of the numerical models (and provide a recommendation and associated documentation) by an appropriate cutoff date. 10. In the discussion of each workshop (e.g., Task 3, page 10), there is a description of a process for PPRP caucusing and reporting. (i) Post-workshop caucus. This function would better be described as PPRP deliberations, and the language should preserve the PPRP' s option of completing them later via phone and/ or email (e.g., in the event that schedule conflicts prevent the full panel convening immediately after workshop completion). (ii) Written comments. There is reference to written comments and feedback to the PTI and TI team at the time of the half-day workshop deliberations. But there is also a reference later on to the PPRP submitting a letter providing observations on the workshop. The Project Plan should be edited to clarify that the PPRP will provide only verbal comments and feedback to the PTI and TI team at the conclusion of each workshop. with the written version of the PPRP comments provided at a later date (so that they can be carefully edited and a PPRP consensus built and confirmed). 11. Under "Topics to be addressed at Workshop 1" (page 11 ), there are a few points that might benefit from some clarification. First, we suggest that there be an item explicitly mentioning the identification of data needs or gaps, as that is one of the essential purposes of the first workshop. Also, because specific mention is made of reviewing GMPEs from PEER, it might be appropriate to also explicitly mention the review of non-PEER GMPEs in this list. There is also a reference to "moderate (M 5.5-6.5) earthquakes occurring 30-100 km from a site." What is the basis for selecting this distance range? Does this M-R range matter to DCPP and SONGS? Finally, on the same page, there is a reference to selecting "a representative reference VS30 that is applicable to all three sites." Have all three PTis agreed to this? 12. Since the hazard analysts have been named in the Project Plan, it would be good, in the interests of consistency, to outline their qualifications in the appendix (and note this at the appropriate point in the main text), just as you have for all the other named participants (it may seem odd if they are singled out for omission). Minor editorial notes and comments. Page i (Table of Contents): Page numbers should be updated to be consistent with the current version 'INTRODUCTION AND CONTEXT OF TllE STUDY' should be included. 'APPENDIX A, should be included. Page 1: First paragraph notes a SSHAC level 3 requirement for all operating nuclear power plants. Is this true for CEUS plants (or are they allowed to perform Level 2 study)? Figure 2 could be improved by showing the schedule in a chart. similar to the one shown by John Barneich at the kickoff meeting. It would be helpful if this chart also shows the schedules of the 3 SSC studies, as was done in John's chart. Page 2: L12, should be NRC, 2012 (not 2011). Page 3:

First line of Project Sponsor description, should say "provide" (not "provides"). Page 4: "Evaluator Expert (EE)" is not shown in the organization chart (Figure l ). Line 6, typo "and" (delete "s") 3rd paragraph, "The REs provide their specialized knows to ... ", knows should be changed to "knowledge". Page 5: 1. 5 lines from bottom, with reference to "applicability of NGA-West2 .. to the SWUS region." Perhaps the issue should be stated as applicability to the three SWUS sites of interest, since each might require its own adjustment to the ground motion model(s). Page 6: 8th line of the SWUS GMC WORK PLAN ... section, I think you mean "By receiving feedback ... ", rather than "by providing feedback ... " Second line from bottom, end of sentence, delete extra period Page 7: 4*h paragraph, line 3 -"There may also be site-specific versions of the GMC logic tress to address site-specific issues .. ". We suggest changing "versions" to "modifications". Page 8: I 0 lines from bottom, "database" should be one word. 5 lines from bottom, "outlines" (not outlining) Page 9: First line of last sentence, "a major" (not "an") Line 4, "subsequent to the kickoff meeting" (the PPRP letter will not be prepared until after the Kickoff Meeting) I st paragraph, line 3 -"Training on the SSHAC process will also take place at the off meeting." This training was not listed in the kick-off meeting agenda. Terms "ergodic sigma" and "single-station sigma" should be (briefly) defined. First line, last paragraph, "a major" (not "an") Page 10: Final paragraph, first line, delete extraneous "the" (before "Workshop 1") and "as" (before the word "mainly") Second line of Task 3 section, " ... list of RE' s will be provided to the PPRP ... " (the words "will be" are missing) Page 11: Fourth item in topics list, extraneous word "the" (before "PEER") Correct the subscript formatting in item 8, and eliminate period (for parallelism with other list items) Page 12: Line 3, "Vl" (rather than "VO") In Task 5, state that the latest version of the SSC model will be implemented in the hazard sensitivity analysis. Second to last line, typo: "identify" (not "indentify") Page 13: Line 4, "Database Manager" is not shown in the organization chart. Does the SWUS GMC study have a database manager? Third line from bottom "the Final Report" (missing "the") Page 14: Line 2, extraneous "the" (before "Workshop") Page A-1: Second line, second paragraph, extra space in "internationally recognized" Third paragraph: technically, the 1996-1998 Yucca Mountain project was not a SSHAC study, since the SSHAC process had not been finalized yet-perhaps a qualifier is in order here. Three lines above Table la, delete "as" Page A-2: Table lb, line 2, you probably mean "GMC issues" rather than "SSC issues" 6 lines from bottom, there is a typo in NGA-East Page A-4: Dr. Campbell's bio is not up to date, especially with respect to his experience in SSHAC projects. His bio should be updated as follows: "Dr. Kenneth Campbell is a recognized expert in ground motion and seismic hazard. He has over 30 years experience in developing empirically based GMPEs. He was one of the GMPE developers in the 2008 NGA project and is a developer of updated GMPEs in the ongoing NGA-west2 project. Dr. Campbell also has extensive experience with the SSHAC process. He participated as an expert evaluator in the 1998 Yucca Mountain SSHAC level 4 GMC and is currently an expert evaluator in the ongoing SSHAC level 4 GMC study for the PEGASOS refinement project and Chair of the PPRP in the ongoing SSHAC level 3 GMC study for the Hanford PSHA. In addition, Dr. Campbell has served as a PPRP member for the 2011 BCHydro SSHAC level 3 SSC and GMC studies, was a resource expert in the 2004 EPRI CEUS SSHAC level 3 GMC study, and was a proponent expert for the hybrid empirical method of modifying GMPEs for regional factors in the Blue Castle and Thyspunt SSHAC level 3 GMC studies." Third paragraph, third line, "his key expertise" (rather than "he"): fifth line, "resource expert" (rather than "participant"); sixth line, "Blue Castle" (spelling). Page A-6: Line 1, "PM" (rather than "PPRP") Table 3A, row 2, change "QA" to "QA Staff' Table 3A, Line 3, "development of and adherence to" November 3, 2012 Carola Di Alessandro, Ph.D. Project Manager for the SWUS GMC SSHAC GeoPentech, Inc. 525 N. Cabrillo Park Drive, Suite 280 Santa Ana, CA 9270 I

Dear Dr. Di Alessandro:

The Participatory Peer Review Panel (PPRP) has reviewed the Project Plan (dated October 3, 2012) for the Southwestern U.S. Ground Motion Characterization (SWUS-GMC) SSHAC Level 3 study. The Project Plan document is well prepared, explains the SSHAC Level 3 guidelines well, and provides a framework for successful implementation of those guidelines. The Plan calls for an additional member, not yet named, to be appointed to the Technical Integration (TI) team to provide expertise in numerical ground motion simulation. That appointee should be knowledgeable with respect to the techniques employed in such studies, as well as knowledgeable in the appropriate selection of model parameters for those studies. We look forward to seeing that position filled by an experienced scientist or engineer with a well-established professional or academic reputation, so that this appointment will also bring the TI team an appropriate balance between experienced experts and more junior members. The PPRP requests that some clarifying language be added to the plan, as noted in an attachment to this letter. The panel believes that, with these clarifications, together with the augmentation of the TI team described above, the Project Plan has the elements required for meeting the SSHAC Level 3 objectives. We thank the project team for its efforts in developing the plan and look forward to its implementation. Sincerely, Steven M. Day Chair, PPRP Brian Chiou Member, PPRP Kenneth Campbell Member, PPRP Thomas Rockwell Member, PPRP

Attachment:

Requested clarifications and edits Attachment to PPRP letter of November 3, 2012 Requested clarifications to SWUS GMC Project Plan 1. It still does not appear to us that the project plan spells out clearly that comparison tests will be m<1de of the different h<1zard codes used by the three utilities, as discussed in our initial review1, <1nd we request that this be addressed. 2. The Project Pl<1n stipulates that the PPRP will meet for a half day after Workshops 1 <1nd 2, and we reaffirm our requestz for a modification of the language to note that the PPRP will have the flexibility to complete its post-workshop deliberations by teleconference and/or email. We feel that occasionally, due to scheduling or personal difficulties, those other arrangements may be the optimal way to insure full participation of the panel. 3. The project pl<1n notes that documentation of the numerical simul<1tion methods will be part of the project database, but does not address our concern that the documentation be available to the PPRP in advance of the time when the models are evaluated3. For models like these being developed via university research, it is reasonable to be concerned that insufficient documentation may be available at the time of model evaluation. Hence, it is important that the Project Plan be clear about the documentation ground rules and the consequences of insufficient documentation. Minor editorial notes (i) Page 18, row 5 (Compile Regional GM data for Arizona): Although this work has been discussed during the working meetings and it is clearly important, it was not mentioned in the main text of the Project Plan, so we suggest removing it from Figure 2 or adding some discussion to the Project Plan. (ii) It would be helpful to have the TI Te<1m briefly describe how the simulated dat<1 will be used in the GMC study, in particular in the construction of the logic tree (e.g., will there be branches based on the simulation results?). (iii) Page 12, 2nd paragraph --typo 'Wworkshop' (iv) P<1ge 12, 7th bullet --'as distances' should be 'at distances' 1 PPRP review memo dated 9 /17 /2012, see Note 4 2 Ibid, Note 10 Note 2 November 29, 2012 Carola Di Alessandro, Ph.D. Project Manager for the SWUS GMC SSllAC GeoPentech, Inc. 525 N. Cabrillo Park Drive, Suite 280 Santa Ana, CA 9270 I

Dear Dr. Di Alessandro:

The Participatory Peer Review Panel (PPRP) has reviewed the Project Plan (dated November 12, 2012) for the Southwestern U.S. Ground Motion Characterization GMC) SSHAC Level 3 study. The Project Plan document is well prepared, explains the SSHAC Level 3 guidelines well, and provides a framework for successful implementation of those guidelines. It is responsive to earlier PPRP's rernmmendations, as detailed in our memoranda dated September 17 and November 3, 2012, respectively. The Plan includes a Technical Integration lTI) team that brings the project an appropriate balance between experienced experts and more junior members, and includes high-level expertise in both empirical and simulation-based ground motion estimation. The PPRP believes that the Project Plan has the elements required for meeting the SSHAC Level 3 objectives. We thank the project team for its efforts in developing the plan and look forward to its implementation. Sincerely, Steven M. Day Chair, PPRP Brian Chiou Member, PPRP Kenneth Campbell Member, PPRP .. , .,,,-.. /.. ': ; \. .;;,;t/ --' :/* .,,, / .1 ,A-" ..* $') ....... Thomas Rockwell Member, PPRP April 21, 2013 Carola Di Alessandro, Ph.D. Project Manager for the SWUS GMC SSHAC GcoPentcch, Inc. 525 N. Cabrillo Park Drive, Suite 280 Santa Ana, CA 92701

Dear Dr. Di Alessandro:

This letter provides comments from the Participalory Peer Review Panel (PPRP) on Workshop No. 1 (Significant Issues and Available Data) of the Soulhwestern U.S. Ground Motion Characterization (SWUS GMC) project. The PPRP wishes to thank the management team for the opportunity to participate in the workshop, which was held on March 19-21 in Oakland, California. The PPRP participated as observers, in order to be informed and lo provide a review of both the process and the technical developments. All four members of the PPRP (K. Campbell, B. Chiou, S. Day, and T. Rockwell) attended, and the panel observed all aspects of the workshop. The workshop was organized in a very professional and effective manner, and we appreciate the hospitality shown to us by lhe project team. Summary Comments The technical program was organized and conducted with the highest level of professionalism. As appropriate for the first workshop of a SSllAC Level 3 study, the focus was on framing the hazard issues, identifying available data, and identifying key data needs. The workshop began with a summary of the project, including clear statements of its objectives and scope. The SWUS GMC project inlerfaces with the lhree separate Seismic Source Characterization (SSC) studies supported by the respective sponsoring utilities. A series of presentations on the first day of the workshop outlined lhe principal seismic source issues for each sile, expressed in terms of hazard sensilivity. This introduction was very useful in setting the broader context for the GMC study and in enabling subsequent discussions to focus on data that arc most relevant to hazard. The resource-expert presentations that followed were well chosen, well structured, and comprehensive, and each included a list of references. All five members of lhe Technical Integration (TI) Team were fully engaged in the discussions of these presentations and each played a valuable role in interrogating the presenters. The PPRP is unaware of any relevant avenues that were not explored. The Tl Team did a commendable job of keeping the workshop focus on the data issues, as is appropriate for the first workshop of a SSllAC Level 3 study. Maintaining the right focus was challenging, because the line between data and interprelalions or models is nol a sharp one, but the team found the right balance. A clear separation of roles was mainlained. For example, when occasionally a TI or PPRP Team member was required to comment in the role of a resource expert, that role was always clearly stated. In summary, with respect to process, as well as with respect to technical quality and completeness, lhe workshop met all standards for a SSHAC Level 3 data workshop. A good foundation has been set for the exploration of proponent models in Workshop No. 2. Specific comments and recommendations are given below. Those specific comments, suggestions, or recommendations that require a written response are underlined. Recommendations 1. Site Kappa and Single-Station Sigma Terminology. Several resource experts presented very interesting and insightful information on the data needed to estimate the site attenuation parameter kappa and the ground motion standard deviation parameter site sigma. However, this material is quite technical and some of it is quite new. Not all parlicipanls and observers seemed lo have a shared underslanding of the terminologies being employed or how the estimated quantities can be applied in a self-consistent manner at each of the nuclear power plant sites where they wil1 be used. Our concern comes partly from the lack of probing questions of the kappa and single-site sigma resource experts from the TI Team, partly from a lack of significant questions from the audience, and partly from questions expressed by members of the PPRP. Therefore, the PPRP suggests that the Tl Team write White Papers, i.e., authoritative technical notes, on site kappa and single-station sigma, respectively, that define the terms, indicate how they are going lo be estimaled, and how they are to be used in the seismic hazard analysis of each of the NPPs. These documents would provide a common language and reference frame for future discussions and help allay concerns about possible double counting or other inconsistencies in lhese two parameters. 2. Splay Fault Modeling. The workshop included some discussion of dynamic rupture modeling of splay faulting, especially models leading to possible concurrent rupture of the Hosgri and Shoreline faults. Our understanding is that SCEC has been tasked with performing such modeling. We are concerned that this effort may not be as well interfaced with the relevant SSllAC projects (the DCPP and SONGS SSC studies and the SWUS GMC study) as it could be. In particular, the occurrence and extent of concurrent rupture on a splay depends quile slrongly on the orientation of the maximum principal stress direction. It is likely also to be sensitive lo rupture velocity. The SCEC team tasked for this work has been principa11y focused on canonical test problems for the purpose of code verification; it should not simply be assumed that the SCEC group has sufficient expertise and experience in the specific rupture dynamics questions being posed by the SSHAC projects to operate independenlly. The presentation al the workshop did not suggest that the SCEC team recognizes the importance of the principal stress orientations, nor the importance of exploring conditions conducive to a range of rupture velocities. We recommend that the SWUS GMC project and the other relevant SSHAC projects devise a plan to provide ongoing guidance and foedback to the SCEC modeling team.

3. DCPP-SSC inte1face issue: Slab Earthquakes. During the workshop, the possibility of earthquakes within a relic subducted slab beneath DCPP was broached during the presentation overviewing the DCPP SSC project. To our knowledge, this possibility of slab sources had not been mentioned at previous DCPP SSC workshops, and from the discussion at the workshop, it was not clear which project takes responsibility for assessing its technical defensibility and implications. Slab earthquakes arc known to excite ground motion with systematically distinct characteristics relative to crustal sources. We recommend that the two projects clarify the lines of responsibility and establish effective communication on this subject so that the Tl Team is not taken by surprise if slab events arc characterized in the DCPP SSC. 4. DCPP-SSC and SONGS-SSC intef:face issue: Afaximum depth qf' rupture in crustal earthquakes. During the DCPP-SSC overview presented at the workshop, the possibility was raised of deep rnpturc penetration, i.e., rnpture extending to greater than I 5-20 km depth, on some crustal faults in California. The SWUS-GMC TI Team seemed unaware that this was a possibility in the DCPP SSC project and it was not clear to us which project takes responsibility for the technical assessment of deep rnpturc. Furthcnnorc, although this issue was not raised in the SONGS-SSC overview, similar depth-of-rnpturc considerations may pertain to both California sites. We recommend that the SWUS-GMC project work with the DCPP-SSC and SONGS-SSC projects, respectively, to clarify ownership of the depth-of-rupture problem and begin to communicate effectively and regularly about the status and implications of those ideas. 5. Path-Spec(/ic Attenuation.for Palo Verde. The attenuation of ground motion between distant earthquakes and PVNPS may be quite strongly dependent upon the source location and might not be well represented by a single function of distance. The Tl Team clearly recognizes this likelihood and has taken it into consideration in their plan to empirically estimate attenuation from distant sources to PVNPS using existing recordings from relevant source regions. We consider this a sound approach. llowcver, the PPRP would suggest that the empirical approach be carefully applied in the light of a geological understanding of both the source and path regions (for example, it might be observed that paths crossing the Salton Trough are highly attenuative and geologic understanding might dictate that the same empirical correction not be applied to nearby sources that do not cross that province). 6. Iland-o.fl to Site-Spec(/ic Site-Response Team. The GMC TI Team is proposing to characterize ground motions for a common reference rock condition with Ys'.lo = 760 m/s and to adjust the base case GMC model to incorporate utility-specific differences in site characteristics and modeling approach. We understand that each utility will adjust the resulting rock hazards to the local site condition at each NPP site when deriving the I lazard-Consistcnt Ground Motion Response Spectra (GMRS). The Tl Team have acknowledged the need for interaction between these two efforts and emphasized the importance of proper handoff of the GMC model to the team responsible for specific site-response analysis. Still, we want to further emphasize it here by cautioning that lack of clarity and precision in the communication between the GMC Tl Team and lhe site response analysis team may make both vulnerable to misunderstandings and claims of inconsistency or double counting of effects. We recommend that the TI Team and the individual site projects collaborate to generate as soon as possible a reference document that describes the respective a(ljustments and procedures to be used at each site, and thal explains the technical rationale in each case. As with the documenls on kappa and single-site sigma recommended in Item I above, such a document would serve to guide future discussions, prevent misunderstandings, and ensure that no relevant data or models are neglected due to uncertainties about which project is responsible. Please feel free to contact us if you would like to discuss further our comments or recommendations. Sincerely, Steven M. Day Chair, PPRP Brian Chiou Member, PPRP Kenneth Campbell Member, PPRP I , f // /-* .. *'" Thomas Rockwell Member, PPRP December 3, 2013 Carola Di Alessandro, Ph.D. Project Manager for the SWUS GMC Project GeoPentech, Inc. 525 N. Cabrillo Park Drive, Suite 280 Santa Ana, CA 92701

Dear Dr. Di Alessandro:

This letter comprises the comments of the Participatory Peer Review Panel (PPRP) on Workshop #2 (Proponent Models and Alternative Interpretations) of the Southwestern U.S. Ground Motion Characterization (SWUS GMC) project. Workshop #2 was held on October 22-24, 2013, in Berkeley, California. The PPRP participated as observers, to monitor the progress of the SWUS GMC project and provide a review of both the process and the technical developments. All four members of the PPRP (K. Campbell, B. Chiou, S. Day, and T. Rockwell) were present for the full workshop and observed all workshop sessions. The panel also met at regular intervals during the workshop to assess its effectiveness in probing the proponent models and in adhering to SSI IAC Level 3 procedural guidelines. The workshop was very well planned and conducted. We appreciate the organizational efforts of the Project Management team, and, in particular their hospitality and attention to our requirements as a review panel. The location and facilities were excellent, and most proponent and resource experts were able to participate for the full three days. The presence throughout the workshop of a critical mass of experts resulted in very focused and thorough discussion of proponent models, key technical issues, and progress on ongoing studies. Summary Comments The technical program was very well prepared by the Technical Integration (TI) team to address appropriate Workshop #2 goals in depth. Those goals are to present, discuss, and debate alternative technical viewpoints, identify alternative hypotheses and their uncertainties, and provide a basis for development of hazard models that consider the full range of alternative technically defensible interpretations. The team made this large task tractable within the confines of a three-day workshop through several devices that maintained focus without sacrificing depth and completeness of the discussions. First, the workshop began with a series of hazard sensitivity presentations that were well designed to provide workshop participants a shared understanding of the key issues. These presentations were very effective in directing subsequent discussions. Second, the TI team prepared well thought-out questions for each proponent expert and submitted these to the experts in advance. Those questions provided good direction to the presenters and guidance to the discussions. At the same time, the format was kept open enough to ensure that potentially relevant issues, concerns, and models not anticipated by the TI team could be proposed and explored, and several such examples received valuable discussion. 1 Each resource-expert or proponent-expert presentation was well chosen and each provided thorough coverage of a relevant study or model and included a list of references. The TI team interrogated all presenters effectively and led general discussions that successfully engaged the wider audience of ground motion experts. As we nole in our recommendations below, most of the questioning during the first part of the workshop came from just a few of the Tl team members. The PPRP encouraged all five members of the TI Team to bring their voices to bear in this process, and by the end of the workshop we were pleased to see progress toward a more balanced engagement of all team members. The overall process was successful in revealing the strengths, weaknesses, and uncertainties of the competing models, and, except as noted in the recommendations listed below, Lhe PPRP is unaware of relevanl issues that were not explored. With respect to adherence to procedural guidelines, as well as with respect to technical quality, the workshop confom1ed well to standards for a SSllAC Level 3 workshop on alternative models and interpretations. There are some remaining issues of completeness Lhat should be considered prior to Workshop #3, and these are noted, along wilh other issues to consider, in the comments and recommendations below. Those specific comments or recommendations that require a written response arc underlined. Recommendations I. Bala11ced participatio11 by the Tl team members. During the first two days of the workshop, a disproportionate amount of the interrogation of the proponent experts was done by Lhe TI lead, with some conlributions from other senior members of the team. Other members were not significantly engaged in the discussions on those days. This imbalance is a concern, because SSI IAC guidelines for a Level 3 study explicitly call for TI Leam members to be prepared Lo voice independent views and technical challenges. The PPRP was pleased to see more balanced participation on the third day and recommends that the Tl team take concrete steps to ensure that this progress continues during the remainder of the project. The importance of full TI team participation is emphasized in the NRC SSHAC guidance document (NUREG-2117), which states, for example (p. 36) "membership in the Tl team automatically implies sharing the ownership qf the component models developed by that team," and (p. 38), while discussing the distinction of a Level 3 SSI IAC study in contrast to lower level SSI IAC studies, "The Tl must now be a team rather than an individual or small group .... at Level 3. this is essential both because no individual has the breadth o,/expertise required and because o.l the necessityfor technical challenge and defense among the evaluators. " 2. Selecti<m criteria and dedsion date for G1°"1PEs. Some of the ground motion prediction equations (GMPEs) presented and discussed al the workshop appeared to the PPRP to be at a less mature stage of development than the others. For example, one has not yet been fully described and documented in a formal publication. We recommend that the TI team formulate and document, as soon as possible, dear criteria to be employed to detennine which GMPEs will be used in hazard model developmenl, and thal documentation of the acceptance criteria include a justification, and that it specify a firm 2 cutoff date for achievement of the criteria, based on a realistic assessment of schedule requirements. The selection criteria should be applied on a consistent basis to all candidate GMPEs. 3. Completeness of proponent-model analysis in Workshop #1. The project team made a thorough effort to identify, select, and invite proponents of alternative interpretations. Not all invited proponents were able to attend the workshop. In the absence of a proponent to support the GMPE and magnitude-scaling recommendations of Dr. Zhao and his colleagues, their viewpoints on magnitude scaling of ground motion were solicited and presented by the TI Team; therefore an opportunity existed at the workshop to discuss and challenge them. This approach was fully consistent with guidance in the NRC SSHAC guidance document (NUREG-2117) (p. 70), which states, for example: "Because not all proponents ql alternative viewpoints may be able to attend the workshop, interpretations made by individuals who may not be present should be ident{fied and discussed." On the other hand, Dr. Idriss (author of the Idriss NGA-West2 GMPE) and Ors. Atkinson and Assatourians (developers of the finite-fault stochastic simulation method, EXSIM) also were absent, yet no representatives were designated to represent their models. As a result, discussion and debate of the merits of these two models were largely incomplete. The PPRP recommends that the TI team make an additional effort to complete the evaluation of these two proponent models at a level equal to that of the other models being evaluated. It should take place before the development of preliminary hazard models, and in a setting consistent with NUREG 2117, which stipulates (p. 39) that in a Level 3 study, the interactions with proponent experts should be "conducted openly in the presence qlobservers including the PPRP." 4. Completion of Workshop #2 objectives. The PPRP noted that there were many ongoing tasks that could not be evaluated in Workshop #2 because they were either incomplete or had just begun. The TI lead pointed out during the workshop that these tasks will need to be fully discussed and evaluated in order for the TI team to obtain feedback from the resource and proponent experts to factor into their evaluation. The PPRP agrees that there is the need for an additional meeting with resource and proponent experts, including the PPRP as observers, to cover these ongoing and incomplete tasks. The PPRP emphasizes, moreover, that sufficient time should be allowed between such a meeting and Workshop #3 to enable the Tl Team to fully evaluate and discuss the feedback from the meeting and incorporate that feedback into the preliminary ground motion logic tree and the related sensitivity studies that will be presented and discussed in Workshop #3. This concept is embodied in the NRC SSHAC guidance document (NUREG-2 I 17) that states (p. 67) "Any new data collection activities should be ident(fied early in the project, evaluated for their potential impact on the hazard results and associated uncertainties, and completed in a timely manner .for use in the technical evaluations. this would mean that the activities should be completed prior to Workshop #3 on Feedback and certainly no later than the time that the models are .finalized; (p. 68) Each workshop has a 5pec(fic focus and goal, and each requires that particular work activities have been conducted prior to its occurrence a11d certain work activities will occur and (p. 73) "Following Workshop #2 and prior to Workshop #3 Feedback. multiple l*vorking meetings will be necessary to develop a 3 preliminary model that can be used for purposes o,f sensitivity to provide the necessa1yfeedback to the Tl Team." Tl Team should consider scheduling this additional meeting such that there is sufficient time between it and Workshop #3 to prepare and revise the preliminary ground motion logic tree and to perform related sensitivity studies. 5. Schedule a11d prioritization. Over the course of the workshop, numerous technical issues that arc currently under investigation were identified as requiring substantial further work before certain modeling procedures can be included in a hazard model. The PPRP is very pleased that the project has initiated important investigations that are likely to have a big impact over the longer tcnn, and the fact that some will not reach full practical implementation during this project is understandable and inevitable in an effort such as this one. As the TI lead noted, in the short term, incomplete resolution of these technical issues can be accommodated in the hazard model through appropriate expansion of epistemic uncertainty estimates. The PPRP urges, however, that the TI team reach a prompt decision on which efforts to prioritize for inclusion in the hazard model. That decision should consider hazard sensitivities, and should be made early enough to realistically account for project schedule requirements. For example, by Workshop #3, which is scheduled for March 2014, a preliminary hazard model should have sufficient maturity that the PPRP and others can meaningfully probe its technical basis and understand the manner in which it incorporates the views of the larger technical community. We also note that a preliminary report is due for PPRP review within just a couple of months following Workshop #3. Please feel free to contact us if you would like to discuss further our comments or recommendations. Sincerely, Steven M. Day Chair, PPRP Brian Chiou Member, PPRP Kenneth W. Campbell Member, PPRP * Thomas Rock well Member, PPRP 4 April 21, 2014 Carola Di Alessandro, Ph.D. Project Manager for the SWUS GMC Project GeoPentech, Inc. 525 N. Cabrillo Park Drive, Suite 280 Santa Ana, CA 92701

Dear Dr. Di Alessandro:

This letter comprises the comments of the Participatory Peer Review Panel (PPRP) for Workshop #3 of the Southwestern U.S. Ground Motion Characterization (SWUS GMC) project. Workshop #3 was held on March 10-12, 2014, in Berkeley, California. The PPRP observed both the process and the technical developments. Fo11owing the guidelines of NUREG-2117, the PPRP also actively participated in the discussion and questioning of the preliminary models. The four members of the PPRP (K. Campbell, B. Chiou, S. Day, and T. Rockwell) were present for the full workshop and observed all workshop sessions. The PPRP met at regular intervals during the workshop to assess its effectiveness in providing feedback to the model evaluators, as we11 as its adherence to SSI IAC Level 3 procedural guidelines. The PPRP congratulates the TI and Project Management teams for carrying out a very successful workshop in conformity with SSI IAC Level 3 guidelines. The Tl team organized the workshop fonnat and presentations effectively, and we appreciate the efforts they and the Project Management team made to provide the PPRP with ample opportunity to interrogate the presenters. Summary Comments The goals of Workshop #3 are (1) to present the preliminary models, with emphasis on how alternative interpretations and uncertainties have been incorporated, (2) present sensitivity analyses and hazard calculations that provide insight into the preliminary models, and (3) address questions, including those from the PPRP, to provide an understanding of the technical bases for the model components and weights, and the manner in which the center, body and range (CBR) of tcchnica11y defensible interpretations (TOI) have been included in the models. The Tl team designed a set of presentations and discussions that was very successful in describing and exploring the overall structure for the GMC model. This enabled the PPRP to gain a good understanding of how the model is being framed. Several components of the model are very advanced and innovative. The use of Sammon mapping to visualize relationships among ground motion predictions (and to compare them with data and numerical simulations) is an especially noteworthy development. Also noteworthy is the exploration of possible non-Gaussian upper tails lo ground motion distributions, and their incorporation into the characterization of aleatory uncertainty via a mixture of two Gaussian distributions. Likewise, non-ergodic aleatory uncertainty is being addressed with exceptional rigor in this project, and path-specific terms arc being developed and applied where available data permit. We commend the TI team on their continuing efforts to bring these technical advances to fruition. 1 With respect to adherence to procedural guidelines, as well as with respect lo technical quality, the workshop confcmncd well to standards for a SSI IAC Level 3 workshop on model feedback. The entire Tl team was fu11y engaged in presenting the model clements and addressing questions. The TI team and the project manager were attentive to the role of the PPRP. During the presentation and discussion of each model element, the TI team allocated sufficient time for the PPRP to ask detailed questions about the model fommlation, its technical justifications, the basis for incorporation or rejection of alternative models, and the manner in which uncertainty is characterized. The TI lead, Project Manager, and in some cases the TI Team members met with the PPRP at the end of each day of the workshop to obtain immediate feedback. A number of requests for program adjustments were made at these meetings, and the Tl team was fully responsive to al1 such requests. Parts of the model evaluation process arc stil1 in progress, and a complete preliminary model was not available at the time of the workshop. However, the presentations and discussions of the model framework and the key individual model elements were sufficient to enable the PPR P to provide substantial feedback to the Tl team. In the comments and recommendations below, we endorse the Tl team's plans to obtain further model feedback from the PPRP once a complete preliminary model is available. Comments and Recommendations (underlining indicates those requiring a written response) J. Do£*umentation. As noted in the summary comments, the ground motion model contains a number of advanced clements aimed at providing improved confidence that the CBR of the TOI is being captured. The scientific development and validation of these advanced clements has been driven in large part by this project. The technical bases for these elements appear to be sound, and they represent significant advances in hazard assessment. However, because they are tcchnica11y advanced and relatively complex, they will have to be carefully and fully documented in the project report. Careful and clear documentation of complex procedures and concepts (for example, the construction of a multidimensional GMPE space, its visualization via Sammon mapping, and its final characterization from representative points on that map, in light of disparate data sets and simulation results) may be critical to project success. The PPRP recommends that Tl team members pay close attention to the documentation of these advanced model elements to ensure that the final report is not only complete and scientifically sound, but also as transparent and persuasive as possible to the PPRP and a broader technical audience. 2. Site effects interface issue. During the workshop, it became clear that the project had not yet produced a comprehensive reference document describing the adjustments and procedures to be used to modify the reference ground motions for use al each site (i.e., at PVNGS and DCPP). The PPRP previously recommended that such a document be developed in a letter to the Project Manager dated April 21, 2013 (Recommendation #6) following Workshop #1, and this recommendation is repeated here. As noted previously, any lack of clarity and precision in the communication between the TI team and a site response analysis team may make both vulnerable to misunderstandings and claims of inconsistency or double counting of effects. A comprehensive written document would serve to guide discussions, prevent misunderstandings, and ensure that no relevant data or models are neglected due to confusion about which project is responsible for which elements of the ground motion model. 2

3. SSC interface issue. The workshop revealed some apparent gaps in coordinalion between lhe Tl team and the respective SSC Tl teams for the DCPP and PVNGS SSllAC Level 3 projects. For example, the Tl team appeared to be unaware of the inclusion of strike-slip sources in the local-source component of the SSC model for PVNGS, and only presented GMC models relevanl to nonnal faulting. As a second example, the TI team discussed the PVNGS sourcc component in tenns of random fault orientations, whereas the PVNGS SSC TI team wil1 provide preferred orientations in the final SSC model. A further concern is that the DCPP SSC model might include a large range of rakes on dipping faults, and some coordination between that project and the GMC project may be required to ensure that those sources are appropriately categorized for use in the GMC model (e.g., the treatment of oblique slip sources was not discussed by the TI team). The PPRP recommends that the Tl team improve coordination with the TI teams of each of the SSC projecls to ensure that the GMC approach is fully compalible with the respective SSC approaches, so that last-minute issues will not arise that could delay project completion. 4. Feedha£*k on a complete preliminary model. The workshop provided a very good exposition of lhe conceptual framework of the ground molion logic lrees to be employed, as well as their technical bases. In most cases, the specific branches were identified, and there was extensive technical questioning and discussion from the PPRP and other experts, meeting most of the workshop objeclives. Nonetheless, the model feedback process was not quile completed at Workshop #3, because a complete preliminary model populated with weights was not available to be interrogated by the PPRP at that time. As noted in NUREG 2117 (p. 71 ), "In the discussions of the preliminary models, the technical bases for the assessments and weights should be described to allow for a discussion of the implications and constraints provided by the available dala." The PPRP supports the TI team's preliminary decision to hold one or more briefing meetings to present a full preliminary model to the PPRP for feedback when it becomes available, in advance of their development of the final model. 5. Geologic consistency of models for ground motion simulation. The numerical simulation of specific sources at DCPP employed fault geometrical parameters (in particular, down-dip fault widths) that arc not consistent with the SSC model. The PPRP recognizes that this may be largely an artifact of the way the numerical models are parameterized, together with the understandable project requirement to hold that parameterization fixed in the form it had when the numerical models were calibrated and validated. The PPRP also recognizes that the principal application of the simulations to date has been to test methods for combining empirical relalionships so as to approximate special conditions not represented well in the database, such as the simultaneous rupture on a main fault and a secondary splay. In thal type of application, lhe PPRP agrees that the results may be insensitive to the precise simulation geometry relative to the SSC model. Ilowcver, the appearance of discordance between the simulation parameters and actual fault parameters developed by the DCPP SSC is a potential source of confusion. The PPRP recommends lhat project documenlalion give careful auention to any apparent inconsistency between the ground motion simulation parameters and the actual fault parameters developed by the DCPP SSC team. Where simulations arc used only to test methods for applying empirical methods to special situations, the TI team might evaluate whether to simply treat the simulated faults as represenlatives of generic faull lypes, rather than associaling lhem wilh specific faults from the SSC model. On the other hand, if simulated ground motions arc 3 employed more directly, it will be necessary to document with care their actual relationship to the SSC model. 6. Representation CBR of liypocenter location.ti. In the development of the model of additional standard deviation to account for rupture directivity, the TI team assumed a model of hypocenter locations in which strike-slip earthquake epicenters had a tendency to concentrate near the center of the rupture trace. The team cited empirical results of Mai and others in support of this assumption. However, other relevant data are available (e.g., global compilations such as that of McGuire et al. in BSSA, 2002, as well as data from detailed studies of individual earthquakes in California and elsewhere). If the form of the hypocenter distribution is significant to the conclusions of the directivity study, the PPRP recommends that the Tl team further evaluate the hypocenter distribution model to ensure adoption of a final version that adequately captures the CBR of the TDI. 7. Frequency shift of between-eve11t standard deviation. The Tl team showed at the workshop that, if not removed by smoothing (as was done by some NGA-West2 developers), the event standard deviation tau has a so-called "bump" at short periods that is not as visible in the within-earthquake standard deviation phi. The Tl team showed evidence from a simple stochastic analysis that this bump is likely due to systematic variability in site effects, presumably due to variability in kappa, that is being transferred to tau and should, therefore, be included as part of the within-earthquake variability. Based on this conclusion, the TI team has adopted as part of their logic tree a smoothed short-period tau model with no bump and instead is transferring this aleatory variability to the site-response model. One of the interesting features of the bump in tau, which is often described as being at O. l sec ( l 0 Hz), is that it occurs at a shorter period for small earthquakes than for large earthquakes and has a pronounced dip near 0.3-0.5 sec, which also changes with magnitude. The PPRP recommends that the Tl team seek an explanation of the apparent frequency shift of the bump and dip in tau with magnitude and assess whether it is consistent with the proposed hypothesis that these effocts represent variability in site effects rather than source effects. 8. Epistemic uncertainty iii median predictio11. The epistemic uncertainty in predicted median ground motion includes two components the within-GMPE uncertainty of estimated GMPE coefficients and the between-GMPE variability. At the workshop, the TI team's proposed approach for evaluating the latter component of uncertainty (via the construction of GMPE space) received substantial discussion and helpful feedback. There was, however, not as much discussion of the within-GMPE uncertainty. Since uncertainty in median motion is an important contributor to the uncertainty in calculated hazard, the PPRP recommends that both bet G M PE and within-GMPE components of epistemic uncertainty be evaluated with comparable rigor and that each be represented in the logic tree with an appropriate level of detail. A potential means to capture within-GMPE uncertainty in a manner comparable to the treatment of between-GMPE uncertainty was noted by the Tl lead during the workshop. The suggestion was that the within-GMPE covariance matrix of a training GMPE be used to generate more training GMPEs for the purpose of constructing GMPE space. The PPRP will be interested in any update of the TI team's views of this approach and any plans that they have to further evaluate it. 4 Please feel free to contact us if you would like to discuss further our comments or recommendations. Sincerely, Steven M. Day Chair, PPRP Brian Chiou Member, PPRP Kenneth W. Campbell Member, PPRP I , f // /-... * Thomas K. Rockwell Member, PPR 5 Decemberl3, 2014 Dr. Carola Di Alessandro SWUS Project Manager GeoPentech, Inc. 525 N. Cabril1o Park Drive, Suite 280 Santa Ana, CA 92701

Subject:

Participatory Peer Review Panel Letter No. I: Rev.O Report, Southwest United States Ground Motion Characterization Level 3 SSI IAC Project

Dear Dr. Di Alessandro:

This letter provides comments and recommendations of the Participatory Peer Review Panel (PPRP) for the SWUS Project Report, Rev.O. llerc we address Chapters 7, 10, 11, 12, and 13, and Appendices L, M, N, and R. We have not yet had the opportunity to lhoroughly review the remainder of the report, some of which is nol yet available to us at this time. It should be appreciated, therefore, that the portions of the report considered in this letter may be subject to further comment once the PPRP has reviewed the remainder of lhe report. The review comments arc tabulated by chapter and identified by section, page, paragraph, sentence or line number, and table or figure number where appropriate. Each comment is assigned a unique number for reference, and the table includes an additional column in which the responses of the TI T earn may be recorded. The review is not intended to be editorial, but we do cal1 attention to stylistic or grammatical concerns in instances where they substantia11y affect clarity or may introduce ambiguities. The Rev .0 report covers the full scope of the evaluation and integration efforts of the TI Team. The review comments from the PPRP arc intended to help the Tl Team clarify and expand as necessary the technical basis and justifications for the models and weights used in the final GMC logic trees. Sincerely, Steven M. Day Chair, PPRP Brian Chiou Member, PPRP Kenneth W. Campbell Member, PPRP I , f // /-* .. *'" Thomas K. Rockwell Member, PPRP Comment Response Table Comment Location in Text PPRP Comments Tl Team Responses Number 1. General comments The report lacks terminological and stylistic consistency. This deficiency affects its readability and sometimes renders meanings ambiguous. Just as examples: the report uses inconsistent abbreviations for the NGA West2. inconsistent symbols for some variables (e.g. tau.Tau. r). inconsistent names to refer to data sets. Please edit for overall consistency of style, terminology and notation throughout the report, including main chapters and appendices. 2. General comments Acronyms. technical terms, and individual variables are not consistently defined when they are first used. Please provide a list of acronyms. a list of variables. and a list of terms that the reader can refer to when needed. Please also define these acronyms, parameters, and terms the first time that they are used in the report, after which they need not be defined again as long as the reader can refer to a list as necessary. For example. ASK14. BSSA 14, CB 14, and CY14 are used throughout the report and are defined by their full references sometimes and only their acronyms at other times. Please provide the full references the first time they are used. include them in the list of acronyms, then only reference them by their acronyms after that. 3. General comments There is very inadequate cross-referencing between chapters and between the main chapters and the appendices. While there is no objection to putting technical detail in the appendices, each report chapter must be coherent and self-contained in and of itself in the sense that any appendices that it relies on must be incorporated by explicit references. with sufficient connective text to be readable and understandable. When results from such an appendix are referenced, please cite the relevant section and/or figure or table number within the appendix. 4. General comments Please consider streamlining the presentation by absorbing some of the short appendices with few figures. or that are redundant with other report chapters or appendices. into the appropriate main chapters. In that case, only those appendices that are lengthy, present complex methods or analysis, or contain a large number of figures or tables. could be retained as separate entities. 5. General comments There are many places throughout the report where there are statements of what was done but not why it was done. It is a requirement of the SSHAC process that the justification and basis for each decision by the Tl Team be fully documented Please provide a description of the Tl Team's assessment and evaluation that was done to arrive at the methods, models, and decisions that form the bases for the statements and models presented in the report and appendices. 6. General comments Because the 3-point discretization scheme for representing a continuous distribution was frequently used in the report. please provide a brief discussion of its origin. properties. and accuracy. so that that discussion can be used as a reference throughout the report.

7. General comments Please consider providing a special treatment of the scaled Chi-square distribution in the report. It is invoked frequently, and such a treatment could serve as a reference throughout the report, and also could make related chapters more accessible to the full range of readers As noted later in this review. the presentation of the topic in Chapter 13 is unmotivated, lacks clarity, and its equations are made impenetrable by numerous notational errors. 8. General comments The term proponent model" is used a number of times in the report in ways that seem to be inconsistent with the term's usual meaning in a SSHAC study. In the SSHAC context. the term is usually reserved for models presented by proponent experts. for subsequent evaluation by the Tl Team. In each instance, if the intended usage corresponds to the SSHAC standard, please ensure that it is clear why. If it does not, it is important to avoid the term. as it is misleading. 9. General comments It is appropriate to discuss the center. low and high values of variables when a model is first discussed. but please consider consistently deferring discussion of the weights to the chapter that discusses the related logic tree. The current draft is inconsistent in this regard. CHAPTER 7 GMC Models for the Sigma 10 Section 7 .1 , Page 7 -Please note that Anderson and Brune (1999) was cited but not included 1, Paragraph 1, Line 4 in the references section of this chapter 11. Section 7.1, Page 7-Please clarify that Cj)ss and <ps,,.R are alternative (mutually exclusive) 1, Paragraph 1, Line 6 models for PVNGS (associated with non-path-specific median and path-specific median models, respectively, and also please reference appropriate sections from chapter(s) on median motion. 12. Section 7. 1 , Page 7 -Please replace "!" with "and" to avoid any confusion that <Pss I <f'sP-R is a 1, Paragraph 1, Line 7 ratio of these two terms. 13. Section 7. 1 , Page 7 -For uniformity of coverage, please include in the outline in this section a 1, Paragraph 1, Line reference to chapter 13 where the combining and resam piing of tau and 8-9 phi is discussed. 14. Section 7 .1 , Page 7 -Please consider whether Miller and Rice (1983) is correctly cited here. 1, Paragraph 1, Line 9 Miller and Rice propose moment-preserving sampling of continuous distributions at Gaussian points. Is this reference relevant to the approach actually used in this report? 15. Section 7. 1 , Page 7 -It is not clear whether the term "sigma" is meant to represent a generic 1, Line 10 term for all standard deviations or to represent a specific standard deviation. Please define the term "sigma" the first time it is used and include it in the list of terms. 16. Section 7. 1 , Page 7 -It would be helpful to also give a guide here to the relevant appendices 1. End offirst covering sigma topics that are referenced in this chapter. Please note in paragraph particular that the division of the <pss and s"*" details between two different appendices (N and L, respectively) tends to obscure their close relationship, and any such confusion would be mitigated by an overview discussion of the sigma appendices at this point in the report. 17. Section 7 .1 . 1 , Page Please explain that the site-to-site variability that is removed in order to 7-1. 1st Paragraph of estimate single-station sigma needs to be included as uncertainty in the Section, Line 4 site-specific site-response analyses. whether they are empirical or analytical.

18. Section 7. 1 . 1 , Page Please include citable references to the PSHA studies mentioned in this 7-1. 1st Paragraph of sentence (PEGASOS Refinement Project. Thyspunt Nuclear Siting Section, Last Project. BC Hydro PSHA Project. and Hanford PSHA Project} sentence 19 Section 7 .1 . 1 , Page Please justify your criterion of using "a minimum of 3 recordings. Why is 7-2, First Paragraph, a higher number of recordings not needed (especially given the use of a Line 6 minimum of 5 recordings per station in the <llsP-R analysis for PVNGS described in Appendix L)? 20. Section 7 .2.1, Page Please define the term 'central value' (is it mean, median, or something 7-2, First paragraph, else?). Line 1 21. Section 7.2.1, Page Please cite appropriate references for ASK14, BSSA14, CB14 and 7-2, Paragraph 1, Line CY14, as well as for the errata of the Akkar et al. (2014) and Bindi et al. 2-3 (2014) papers. 22. Section 7 .2.1, Page Please explain whether there was an attempt to obtain the residuals or 7-2, Paragraph 1, Line databases, from which residuals could be calculated, for the Graizer 4 (2014) and Idriss (2014) GMPEs in order that estimates of phi and tau could be derived before these models were rejected. 23. Section 7 .2.1, Page Please provide a reference to the section where plots of the magnitude 7-2. Paragraph 1. Line distribution of the Akkar et al (2014) and Bindi et al. (2014) databases 5 are shown. 24. Section 7 .2.1, Page Regarding the expression "it was assessed." please indicate who did the 7-2, Paragraph 1, Line assessment (i.e., the Tl Team) in order to avoid confusion. Please also 9 ensure that similar references to the writers of the report are replaced with references to the Tl Team throughout the report and appendices. unless someone else did the assessment. in which case they should be clearly identified. Moreover, use of the word "may" implies that it is not known and not assessed. If such an assessment was done, please delete the word "may" to indicate that the Tl Team knows this to be the case. 25. Section 7 .2.1, Page Some studies have developed separate sigma and median models, in 7-2. Paragraph 1. Line which case the model-specific sigma model of each GMPE is not 9 important. Please explain why the Akkar et al (2014} and Bindi et al (2014) GMPEs were rejected on the basis of their sigma models and why the Tl Team decided to use model-specific sigma models instead of a sigma model that is independent of the median model. 26. Section 7.2.2.1, Page Introducing the term "bump" is stylistically questionable (as 7-2, Section title (and acknowledged by the use of quotes) and not as clear as simply calling general comment on the feature a peak (which is unambiguously a feature with a local section) maximum). and leads to inconsistency. as sometimes it is called a peak later in the report (e.g., first line of next paragraph). Please consider whether a more conventional term such as "peak" (without quotes), used consistently in the subsection heading and thereafter. would be suitable here. 27. Section 7 .2 2 1. Page Please explain why ASK14 and CY14 "chose to smooth through these 7-2. Paragraph 1. Line variations" in the period-dependence of tau. 7 28. Section 7.2.2.1, Page Please provide a citable reference to the point-source simulation 7-3. Paragraph 1. Line methodology used by Bob Youngs. Because this work forms the 1 theoretical justification for removing the peak in tau around 10 Hz. please consider adding a more in-depth description of this work either to this section or as an appendix.

29. Section 7.2.2.1, Page Please explain why the particular values of median stress parameter (50 7-3. Paragraph 1. Line bars) and its logarithmic standard deviation (0.5) were selected and why 2 the stress parameter is modeled with a lognormal distribution Please also indicate whether the results are sensitive to the selection of these particular values. 30 Section 7 .2 2 t. Page Please explain what logarithmic standard deviation is. 7-3, Paragraph 1, Line 3 31. Section 7.2.2.1, Page Please ensure that the term "site kappa" has been defined in the report 7-3, Paragraph 1, Line prior to its use in Chapter 7 and included in the list of terms. 4 32. Section 7.2.2.1, Page Please explain why the particular values of median site kappa (0.035 7-3. Paragraph 1. Line sec) and its logarithmic standard deviation (0.3) were selected and why 5 site kappa is modeled with a lognormal distribution Please also indicate whether the results are sensitive to the selection of these particular values. 33. Section 7.2.2.1, Page Please add text to explain what the "WUS amplification factor" is and 7-3, Paragraph 1, Line what effect it is supposed to model (also ensure that the acronym WUS 5 has been defined when it is first used and included in the list of acronvms). 34 Section 7.2.2. t. Page This sentence implies that the site amplification from the Boore and 7-3, Paragraph 1, Line Joyner (1997) site profile is frequency independent; whereas, it is highly 5-7 frequency dependent. Please clarify whether ii is the site factor itself or the variability in this site factor that is frequency-independent. Please explain why the particular values for median site amplification variability (0) and its logarithmic standard deviation (0.4) were selected and why site amplification is modeled with a lognormal distribution. 35 Section 7 .2 2 1. Page Please describe how you obtain the residual standard deviations from 7-3. Paragraph simulation data. 1, Line 7 36. Section 7.2.2.1, Page Please also state that this methodology does not explain the "dip" in tau 7-3. Paragraph at around T = 0.4 sec. t. Line 8 37. Section 7.2.2.1, Page Please describe the frequency-dependent site factor that was used. 7-3, Paragraph 1. Line 9 38. Section 7.2.2.1, Page Please consider providing a clear statement of what variable was 7-3, Paragraph 2, Line correlated with kappa, and how this correlation was determined, in the t 2nd set of simulations. 39. Section 7.2.2.1, Page Please consider whether the phrase "tau is a measure of the average 7-3, Paragraph differences in ground motion from earthquake to earthquake" should be 2. Line 4 more precisely formulated to reflect the fact that tau is a parameter that measures the dispersion of deviation (from average). 40. Section 7.2.2.1, Page Please revise this sentence to make it clear that the total variance in 7-3. Paragraph kappa is partitioned into two components: the event-to-event variation of 2. Line 7 median site kappa of an event and the within-event variation of site kappa at 50 sites. 41. Section 7.2.2. t. Page Please clarify whether you mean "average" or "median". 7-3. Paragraph 2. Line 11

42. Section 7.2.2.2, Page Please rewrite paragraph for greater precision and clarity. The first two 7-4. Paragraph 1. sentences of this section read as though the previous section of the Lines 1 and 2 report was not there. Furthermore. they are imprecise. NGA-West2 analyses (not models) found the tau peak cited. The second sentence can be read as implying that the NGA-West2 studies attributed the peak to the kappa correlation. which they did not. 43 Section 7.222. Page Please provide a reference to the section where the removal of the 10 7-4, Paragraph 1, Line Hz peak is discussed and the outcome presented. 3 44. Section 7.222. Page Please further articulate this recommendation to include, for example. 7-4. Paragraph 1. Line how site response should be conducted in order to be consistent with the 4 decision to remove the 10 Hz peak. 45 Section 7.2 3, Page Please use consistent language throughout the report and appendices to 7-4. Paragraph 1. 2nd refer to the set of GMPEs selected for the tau study (currently they are and 3rd Lines: called, e.g., "considered models," "five considered GMPEs," "the 5 GMPEs," "the underlying five models" elsewhere in Chapter 7). 46 Section 7.2 3, Page The cited figures. 7.2.3-2 and 7.2.3-3, are missing. 7-4, second to last line of section 47. Section 7.24, Page The word "significantly represents a subjective judgment by the Tl 7-5. Paragraph 2. 2nd Team. Please replace "significantly" with a more quantitative description Line of the change of tau with period and discuss why 1his change is not considered to be significant. 48 Section 7.2 5, Page On the right hand side. the subscript "w" is incorrectly included 7-5, First Paragraph of section, Equation 7.2.5-1 49. Section 7.2.5, Page Please justify why the within-model variability of tau from CY14 can be 7-5, 1st Paragraph of considered representative of the other four selected models. Also Section, 2nd provide a citable reference to the result from Bob Youngs referred to Sentence here, if one is available. Otherwise provide documentation of that analysis and its results in the chapter or an appendix. 50. Section 7.2.5, Page The phrase "smoothed using a constant across all periods" is misleading 7-5, Paragraph 1 of if the intent was that the average over all periods was done to produce a section. 5th line after period-independent model. Please clarify. eqn 7.2 5-1 51 Section 7.2 5, Page The averaging process doesn't "account" for the stated fact, but rather 7-5. Paragraph 1. Line makes it irrelevant, since the Tl Team elected to use a period-6 after eqn 7.2.5-1 independent model. Please clarify this point. 52. Section 7.2.5, Page Please provide text to explain clearly why the distribution is "scaled", 7-5, Paragraph 2, Line how the scale factor c and degree of freedom k are derived (e.g., are 5 they set to obtain a simultaneous match to mean and variance of tau squared?), and why this distribution is appropriate for modeling the uncertainty in tau squared. 53 Section 7.2 5, Page Please describe what value of tau squared should be entered into the 7-5, Paragraph 2, equations for c and k. This special value of tau characterizing the Second to Last Line distribution should be given a distinct notation to differentiate it from the random variable tau whose distribution is being characterized.

54. Section 7.2.5, Page Please provide additional justification and basis for the magnitude-7-6. Paragraph 1. dependent tau model shown in Figure 7.2.5-5 Sentence 3 55 Section 7 .3.1, Page The hazard sensitivity studies from elsewhere in the report that support 7-6, Paragraph 1, the specific magnitude and distance ranges selected as "important" for Lines 4-5 DCPP should be referenced here, with section and figure numbers cited. Please also provide a more quantitative description of what is meant by "important". since this term represents a subjective judgment of the Tl Team. 56 Section 7 .3.1, Page Please rewrite this sentence to clarify its meaning. and also provide a 7-6, Paragraph 1, reference for the results cited from an external project. Final sentence 57 Section 7 .3.1, Page Please add references to parts of the report where results of the Tl 7-6, Paragraph 2 Team's evaluations are presented (including a reference to a figure supporting the statement that "the calculated <Pss values were consistent among the 4 NGA-West2 models"). 58. Section 7 .3.1, Page Please add precise references to the report and/or appendix section(s) 7-6, Paragraph 3 of where the coefficient of variation estimate of 0.12 is derived (for section. Line 4-7 example. "Appendix M. Section M.3 and Figure M.7"). where use of chi-squared distribution of <Pss is explained and justified. and where the details of model derivation and assessment are available. The general catchall referral to Appendix M in the last sentence of the paragraph is insufficient in this regard. 59. Section 7 .3.1, Page Regarding the statement that " ... values were smoothed over period; 7-7. Paragraph 2 on please clarify nature of smoothing or provide reference to section of page. Line 1 report that does so. 60. Section 7 .3.1, Page Please provide the justification and basis for the proposed high and low 7-7, Last paragraph of values of <Pss and provide missing Table 7.3.1-3. section. last sentence 61. Section 7 .3.1.1, Page Please add text to describe the findings regarding dependence on 7-7, Paragraph 1, Line distance, style-of-faulting, and Vs30. Please also add text (here or in 1 Chapters 11 and 12} to justify the Tl Team's decision to not model such dependence in the logic tree for sigma. 62. Section 7.3.1.1, Page A reference to Workshop 3 (Appendix G) is not sufficient. If this work 7-7, Paragraph 1, Line was done outside the SWUS project, please provide references to 2 publications or peer-reviewed reports. If this work was done within the SWUS project. then please add more documentation or cite sections of the report where such documentation is included. 63 Section 7.3.1.1. Page Please also summarize where in Chapter 7 the models for <Pss and their 7-7, Paragraph 2 coefficients can be found. 64 Section 7 .3.1.1. Page Please further justify the inclusion of the magnitude-independent <pss 7-7. Paragraph 2 branch (with the CA data set) in light of the clearly observed magnitude-dependence shown in Figure M.4. 65 Section 7.3.2, Page The part of the sentence after the comma that starts with "a subsets of 7-7, 1st Paragraph of the single-station" seems to be disconnected from the first part of the Section, 2nd sentence. Please restructure this sentence to clarify its meaning. Sentence 66. Section 7.3.2, Page Please indicate that Figure 7.3.2-1 shows <Pss values for the European 7-7. 2nd Paragraph of dataset. which is not obvious from the text Section, 1st Sentence

67. Section 7.3.2, Page Please provide reference to specific section(s) or appendices of the 7-8. 1*' paragraph on report where this figure for COV(q>ss) is derived. including explanation page. Line 2-4 on and justification of the method based on chi-square distribution page 68. Section 7.3.2, Page Please explain why data for only five spectral periods are shown in 7-8, 1" paragraph on Figure 7.3.2-2. page. Line 4 69 Section 7 .3 2 1. Page Please explain why the CA dataset was not used to develop a 7-8, 1st Paragraph of magnitude-dependent model for PVNGS as it was for DCPP. Section, 1st Sentence 70. Section 7.3 3, Page Please provide further explanation and basis of the statement "No data 7-8. 2nd Paragraph of in the distance range of 200 to 400 km is available in the CB14 dataset". Section, 1st Sentence CB 14 did use data from distances of 80-500 km to fit average anelastic attenuation terms, but did not include these data in the derivation of event terms and within-event standard deviations. 71. Section 7.3.3, Page Please provide reference to specific section(s) or appendices of the 7-8, 3rd Paragraph of report where this figure for COV(q>ss) is derived, including explanation Section, 2nd and justification of the method based on chi-square distribution Sentence 72. Section 7.3.3, Page Please consider deferring any discussion of logic-tree weights and their 7-9 1st Paragraph. 1st justification until the report sections that present the logic-trees. Other Line parts of Chapter 7 present the models and their uncertainty and not the assessment of logic-tree branch weights, which requires additional justification; so introduction of weights in this section appears somewhat inconsistent with the rest of the chapter. 73 Section 7 .4.1, Page Please explain why all four NGA-West2 GMPEs can be used for the 7-9 1st Paragraph of assessment of q>sP-R. whereas CB14 was excluded from the assessment Section, 1st sentence of <Pss. 74. Section 7.4.1, Page Please justify why only three spectral periods are sufficient to define the 7-9 1st Paragraph of period-dependence of single-path term <p:;p.I{, given that the observed Section, 2nd dependence of this standard deviation for other spectral periods might Sentence deviate from that shown in Figure 7 .4. 1-1. 75. Section 7 .4. 1, Page Please provide a discussion of why the 0.2 s result is unstable. 7-9. 1st Paragraph of Section, 3*d sentence 76 Section 7 .4.1, Page Please provide justification for the use of a chi-square distribution and 7-9 1st Paragraph of provide a reference to this distribution and the related equations. Please Section, 4rd Sentence also provide a reference (i.e., the section in Appendix M) for the selection of a COV of 0.17; the explanation in the 4th Sentence requires additional *ustification. 77. Section 7 .4.1, Page The related materials provided in Appendix Lare little more than a 7-9, 1st Paragraph of repeat of these sentences. The required technical details and basis for Section, 4:* sentence the proposed models for ills*-K are lacking. Please provide sufficient and remainder of documentation so report satisfies SSHAC Level 3's requirement of being paragraph clear. transparent. and complete. Any references to the appendix should be specific with respect to sections, tables, figures. 78. Section 7.5, Page 7-In addition to presenting the comparison, please discuss the important 9, Paragraph 1 findings and how they agree (or disagree) with the logic-tree models proposed by the the Tl T earn

79. Section 7.5, Page 7-Please supply a reference for the Hanford project magnitude-dependent 9. Paragraph 1. Line 8 <pss-80. References, Page 7-Please update Abrahamson et al. (2014) with journal volume and pages. 10, Item 3 81. References, Page 7 -Please add reference for published erratum to Akkar et al. (2014) and 10, Item 4 cite both original paper and erratum in text. 82. References, Page 7-Ang and Tang (2007) is not cited in text. Please remove from references 10, Item 7 unless a citation is added to text. If ii is cited, please cite by page number. and also include publisher location in the reference section entry. 83 References. Page 7-Please include an additional reference to the published erratum to Bindi 10, Item 9 et al. (2014) and cite both references in the text. 84. References, Page 7-Please update the Boore et al. (2014) and Campbell and Bozorgnia 10, Items 11 and 12 (2014) references to include the specific journal volume and pages. 85 References. Page 7-Please update the Chiou and Youngs (2014} reference to include the 10, Item 14 specific journal volume and pages. 86 References. Page 7-Please provide the page numbers or paper number for the Graizer 11, Item 1 (2013) reference. 87. References, Page 7-Please update the Idriss (2014) reference to include the specific journal 11, Item 2 volume and pages. 88 References. Page 7-Please list the publisher's name and location for the Rodriguez-Marek 11 and Cotton (2011) reference 89 Tables 7.3.1-1. 7.3.1-These three tables are missing 2. and 7.3.1-3 90. Figures 7.2.3-2 and These figures are missing. 7.2.3-3 91. Figure 7.3.2-3, Page Please indicate in the caption which panel is PGA and which is 1s PSA 7-33 (the panel headers do this. but the information needs to be clearer. especially as the header uses T0.000 while the caption refers to PGA) 92. Figure 7.5-5 Please replace"/" with "and" so that the term "hisslPhisp.f<" will not be confused as being a ratio. Also note that the figure is mislabeled (as 7.5-6) 93. Figure 7.5-7 To maintain consistency, please describe the three Italian datasets referred to as "Italy, PhiSS1 -Italy, PhiSS2 -ltaly-PhiSS3" in the text. CHAPTER 10 Tau Model Logic Tree for Both DCPP and PVNGS 94. General The chapter is tersely written, often with insufficient background information provided, and insufficiently thorough documentation of the logic tree and the assessment and evaluation that went into determining its branches and weights. Please ensure that the chapter is self-contained, with an adequate summary that references back to Chapter 7 (sigma overview chapter), and other chapters and appendices as needed.

95. Section 10.0 This paragraph has little substance. Please consider providing a somewhat more complete outline of the chapter. 96 Section 10.1. Page Please point out the meaning of red versus green coding of the weights 10-1, Paragraph 1, in Figure 10-1 (and in the caption of that figure) Line 2 97. Section 10.1, Page Please list or provide a reference to the parameter values of the scaled 10-1. Paragraph 1. Chi-square distribution that were used to compute the quantiles. Also. Line 2 please confirm that it is the mean. not the 50th percentile. that was used for the central branch. 98. Section 10.2, Page Please consider replacing "observations" with "assessment" to indicate 10-1, 1st Paragraph of that at this stage of the evaluation and integration that the Tl Team has Section, 2nd Line made its assessments of the proposed model. 99. Section 10.2, Page Please reference the appropriate sections of the chapter or appendix 10-1 , Item No. 1 where the hazard sensitivity analysis is presented that justifies the specified magnitude and distances ranges of interest. 100. Section 10.2, Page Please also cite the published errata to Akkar et al. (2014) and Bindi et 10-1, Item No. 2, 1st al. (2014) and include these errata in the list of references. Line 101. Section 10.2. Page The statement that 'The Zhao et al. (2006) magnitude-independent 10-1, Item No. 2, Last proponent 1 model is judged to be applicable because their database is Sentence almost entirely composed of recordings from earthquakes with M 2 5" could be understood to be a counter argument to the adoption of a weight of 1.0 for the magnitude-dependent tau model mentioned in the beginning of this section. Please explain how the magnitude-independent tau model of Zhao et al. (2006) was incorporated into the magnitude-dependent tau model or remove this statement and discuss it later in the text. 102. Section 10.2, Page Please either provide the full references to the acronyms BSSA 14, 10-1. Item No. 3, 3rd CB14. CY14. and ASK14 the first time they are mentioned in Chapter 10 and 4th Lines or ensure that they are defined the first time they are mentioned in the report and that they are included in the list of acronyms. 103. Section 10.2, Page Please explain why it is proper to use the word proponent" in this 10-2, Paragraph 1. sentence. Line 4 104. Section 10.3, Page Please avoid using the word "assuming" in this context, but rather 10-2, 1st Paragraph of replace it with a phrase that indicates that the logic-tree branches were Section, 1st Line developed by evaluating and assessing available data and results. referencing other sections of the report for supporting analysis if appropriate. 105. Section 10.3, Page Please provide a reference to sectionsfpages in Chapter 7 where the 10-2, Sentence 2 evaluation of 012 is described. 106. Section 10.3. Page Please either provide a reference that supports the specified 10-2. Sentence 2 approximation of a three-point discretization of a chi-square distribution, including the specified weights, or explain the evaluation and basis for this approximation. 107. Section 10.3. Page In light of the discussions in Section 13.2. please clarify if the central. 10-2, general low. and high 't branches described in this section are directly used in comment on section the Hazard Input. If not, please explain the reasons for having this section.

108. Section 10.4, A large number of references contained in this section are not cited by References this chapter. Please clean up the reference list. 109. Figure 10-1. Page 10-Please add an explanation of the color scheme for the branch weights. 4 110. Figure 10-2, Page 10-Please modify Figure 10-2 to show the final magnitude-dependent tau 5 model without all of the various models that were used to derive it and explain that this model is independent of frequency (the figure. being for T = 1 sec, implies that the model might be frequency-dependent). The other models shown in this figure were evaluated in a previous chapter and need not be included in the final logic-tree model. CHAPTER 11 Phi Model Logic Tree: DCPP 111. Title Please add a subscript 'SS' to 'PHI' 112. General The chapter is tersely written. often with insufficient background information provided. and insufficiently thorough documentation of the logic tree and the assessment and evaluation that went into determining its branches and weights. Please ensure that the chapter is self-contained, with an adequate summary that references back to Chapter 7 (sigma overview chapter). and other chapters and appendices as needed. 113. Section 11.1. Page Although the analysis of the aleatory variability is performed on the 11-1, 2nd Paragraph within-event residuals, the distribution is on Phbs. Please remove of Section, 5th "residual" to indicate that the distribution is for Phiss. Sentence 114. Section 11. 1 , Page Please clarify if the phrase involving "aleatory variability" is consistent 11-1, Paragraph 2, with the 'Epistemic Uncertainty' branch heading on Figure 11-1 . Line 6 115. Section 11.2. Page Please provide references for the acronyms ASK14, BSSA14, CB14, 11-1, 1st Paragraph of and CY14 the first time they are mentioned in Chapter 11 or ensure that Section, 3rd Line they are defined the first time they are mentioned in the report and i in *h= I id nf 116. Section 11.3, Page Please further justify the assignment of equal (0.5) weight to the 11-2, Paragraph 1. magnitude-independent branch even though Figure M.4 suggests a clear Line 2 magnitude dependence in the California subset. Appendix references should be specific. citing sections, pages. tables. and/or figures. 117. Section 11.3. Page Please provide a clear reference to where in Appendix M the absence of 11-2. Paragraph 2, M-independence in the global dataset is illustrated. Line 1-2 118. Section 11.4, Page This explanation is pretty cryptic until one studies Appendix M. Please 11-2. Paragraph 2. consider whether clarity would be improved by an explicit statement that Sentences 1 and 2 the sampling distribution of <pss at each site adds an upward bias on top of the true site-to-site variability of Also consider whether the second sentence would be more precisely rendered if removed the bias using" were replaced by "the bias was estimated assuming a chi-squared sampling distribution of Qlss 2 ", with reference to the place in the report where this assumption is justified. 119. Section 11.4. Page Coefficient of variation is abbreviated as CV here. but COV elsewhere. 11-2. Paragraph 2. Please make the notation consistent throughout the report. Sentences 3 and 4 120. Section 11.4, Page The assessment of the low and higher values of <Pss.s was not well 11-2. 2nd Paragraph documented in Appendix Mand in Chapter 7 (see previous comments). of Section. Last Therefore. the statement that "high and low epistemic uncertainty Sentence branches are computed corresponding to the 5th and 95th percentile of <llss.s .. does not have a well-documented basis at this point in the report. Also. the use of present tense infers that the calculations are discussed and included in Chapter 11 rather than in a previous chapter. Please revise Appendix M and Chapter 7 to fully support the assessment that the high and low values of 'Pss.s can be represented as the 5th and 95th percentiles of the epistemic distribution. 121. Section 11.4, Page Please provide the mathematical basis for characterizing the central. 5th, 11-2. 3rd Paragraph and 95th percentile values with weights of 0.6, 0.2. and 0.2. respectively. of Section Please also be more specific when referring to the "central" value as being the median, mean, or another statistical value of the distribution. 122. Section 1.5, Page 11-Please provide a reference to the section (and pages. tables. and/or 3. Paragraph 1. Line 2 figures. if appropriate) where directivity adjustment of <pss is discussed. 123. Section 11.6. Page Please provide a brief description and reference of the "quantile plot (Q-11-3, 1st Paragraph of Q plot)" for clarity. Section, 3rd Line 124. Section 11.6. Page Please define what epsilon is the first time it is mentioned in Chapter 11. 11-3, Paragraph 1. or ensure that ii is defined the first time it is mentioned in the report and Line 4 that it is included in the list of terms. 125. Section 11.6. Page Because the concept of a mixture model is relatively new. all available 11-3, 2nd Paragraph sets of GMPE within-event residuals should be used to demonstrate that of Section, 1st the single mixture model proposed by the Tl Team can be used to Sentence characterize all of them. Please provide the analysis of residuals that was performed for ASK14 for the other three NGA-West2 GMPEs and demonstrate that the proposed normal distribution and mixture model is appropriate for all four GMPEs. 126. Section 11.6. Page Please describe the "statistical tests" that were performed and provide a 11-3, 2nd Paragraph reference for these tests. of Section, 2nd Line 127. Section 11.6. Page Please clarify who conducted the tests on KiK-net data. If it was outside 11-3. Paragraph 2. the SWUS project, please provide a reference. If it was within the SWUS Line 6 project, please give more technical material so there is sufficient technical basis to support the conclusions derived from the KiK-net data. 128. Section 11.6, Page Please rewrite this paragraph to give a more rigorous presentation of 11-3. Paragraph 3 mixture model. including appropriate references. The phrase "a sum of multiple normal distribution" could easily be misunderstood by those who are not familiar with the concept of mixture model. 129. Section 11.6, Page Please describe the technical evaluations that lead to the selection of 11-3. Paragraph 3. mixture of two normal distributions with equal mean. Line 3 130. Section 11.6. Page Please describe the technical evaluations/calibrations that lead to the 11-4, Paragraph 2. (0.5, 0.5) mixture weight and the (1.2, 0.8) scale factors, and that justify Line 4 the application of the model to all of relevant GMPEs (even though the model was calibrated using ASK 14 residuals). Were parameters obtained by trial and error or by methods of statistical inference? 131. Section 11.6. Page Note also that the parenthetical epsilon range should be written with a 11-4. Paragraph 2. minus sign. i.e."(<= -3)" Sentence 6 132. Section 11.6, Page The upper case phi in this equation appears to be the cumulative 11-4. Equation 11-2 distribution function. Please check that the notation has been introduced and defined prior to its use at this point. 133. Section 11.6, Page Please explain what a composite normal distribution is. 11-4, Paragraph 4, Line 1 134. Section 11.6, Page Please provide the technical justification for allowing a normal 11-4, Paragraph 4, distribution with non-zero weight, given that you report that your analysis Line 2 consistently showed heavy tails. 135. References , General Please remove those references that are not cited in the text. comment 136. References, Page 11-Please update the Dawood et al. (2014) reference to include the volume 5. Item 2 and page numbers of the published version. if available. 137. Figure 11-1, Page 11-Caption should explain the meaning of the color scheme used for the 6 weights 138. Figure 11-2, Page 11-Please explain what "Studentized Residual" is in the y-axis label, and 7 correct the caption by replacing "T=2 sec" with 'T=0.5 sec" 139. Figure 11-3, Page 11-Please replace "ASK" with "ASK14" in the cap1ion 8 CHAPTER 12 Phi Model Logic Tree: PVNGS 140. General The chapter is tersely written, often with insufficient background information provided, and insufficiently thorough documentation of the logic tree and the assessment and evaluation that went into determining its branches and weights. Please ensure that the chapter is self-contained, with an adequate summary that references back to Chapter 7 (sigma overview chapter), and other chapters and appendices as needed. 141. Section 12. Page 12-Please replace"/" with "and" here and elsewhere in Chapter 12 to avoid 1, 1st Paragraph, 1st confusion that the term "q>ss I q>s*-f<" refers to a ratio. Line 142. Page 12-1. Paragraph Please clarify whether the first motivation implies there is a significant 1. Line 5 dependence of oon magnitude. distance. and style of faulting. 143. Section 12.1.1. Page Please remove "residual" to clarify that the aleatory distribution is for (j)ss. 12-1, 2nd Paragraph of Section, 4th Line 144. Section 12. 1 . 1 , Page Please consider moving this sentence to the beginning of this section. 12-1, Paragraph 2, Lines 4 to 6 145. Section 12.1.2, Page Please provide a reference to the section where the necessity to use 12-1. Paragraph 1. both datasets is discussed. Sentence 1. Line 1 146. Section 12.1.2. Page Please also reference the published erratum to Akkar et al. (2014 ), in 12-1. 1st Paragraph of which case the reference becomes Akkar et al. (2014a.b). Section, 2nd Line 147. Section 12. 1 . 2, Page Please specify the magnitude and distance range. Also, please confirm 12-2. Paragraph t. that the developers mentioned in this sentence are the NGA GMPE Lines 4 and 5 developers. 148. Section 12.1.2, Page Please consider summarizing these data statistics in a table. Also. t2-2. Paragraph, 1 please clarify if these statistics are based on a data subset in which Lines 3 to 9 each station recorded at least 3 earthquakes. t49. Section 12.1.2. Page Please provide a reference to the sensitivity analyses that show that 12-2, 2nd Paragraph, large (M > 6) magnitudes are important for the hazard calculations at 2nd Line PVNGS. t50. Section 12.1.2. Page Only one limitation of the European dataset is listed as justification for 12-2. 3rd Paragraph the smaller weight given to the European dataset; whereas, several limitations are mentioned in the previous paragraph. Please clarify whether these other limitations contributed to the Tl Team's assessment to give the European dataset less weight. t51. Section 12.1.4. Page Please justify the use of weights of 0.2, 0.6, and 0.2 to define the t2-2. 1st Paragraph of central, 5th, and 95th percentiles of the epistemic distribution of 'Pss. Section, 2nd Please also be specific whether the central value represents the mean Sentence or median. 152. Section 12.2.1, Page The phrase "are added to" could be misleading (suggesting t2-3. 2nd Paragraph mathematical addition of unspecified quantities). so please consider of Section. 3rd Line using another wording. t53. Section 12.2.1. Page Please remove "residual" to clarify that the aleatory distribution is for 12-3. 3rd Paragraph <t>ss. of Section, 4th Line t54. Section 12.2.2. Page Please summarize why a single dataset is appropriate for each branch t2-3. 1st Paragraph of of the logic tree. Section, 4th Line t55. Section 12.2.3. Page Please provide a reference to specific sections, pages. tables, and/or 12-4. 1st Paragraph of figures to Appendix N. Section, 1st Line t56. Section 12.2.4. Page Please provide the basis for the increased CV (i.e .. COV) from 0.14 to t2-4. Paragraph t. 0. t 7 (and please ensure that terminology for coefficient of variation is Line 2 consistent throughout the report and appendices). t57. Section 12.2.4. Page Please justify using weights of 0.2. 0.6. and 0.2 to represent the 5th. t2-4. 1st Paragraph of central. and 95th percentiles of the epistemic distribution of the Phi Section, Last terms. Please also be specific whether the central value represents the Sentence mean or median. 158. Section 12.2.5, Page Please clarify who made the judgment and describe the basis for the 12-4, Paragraph 1. judgment. Line 3: 159. Section 12.2.5, Page Please provide the technical justification for allowing a normal 12-4. Paragraph t. distribution with non-zero weight. given that your analysis consistently Line 4 showed heavy tails. t60. Section 12.3. Page Please revise the date to "2014a" to reflect the published manuscript and t2-4. 1st Item the fact that the erratum was published in the same year. t61. Section 12.3. Page Please update Akkar et al. (2014) to Akkar et al. (2014b} and provide the 12-4, Item 2 volume and page numbers of the published erratum. 162. Section 12.3. Page Please remove the Abrahamson et al. (2014) reference or cite it in the 12-4. Item 3 text. 163. Figure 12-2 Figure is incorrectly numbered ('"Figure 1") CHAPTER 13 Total Sigma Model 164. The chapter is tersely written. often with insufficient background information provided, and insufficiently thorough documentation of the logic tree and the assessment and evaluation that went into determining its branches and weights. Please ensure that the chapter is self-contained, with an adequate summary that references back to Chapter 7 (sigma overview chapter). and other chapters and appendices as needed. 165. Section 13.1 Please provide an overview of the methodology used in other recent SSHAC Level 3 PSHA studies to construct total sigma models. 166. Section 13.1 This methodology can significantly benefit from an extensive rewrite (including related parts in Chapters 7, 10, 11, and 12) to improve readability and understandability. Please provide a clear and easy-to-understand presentation of the basic principles and ideas behind the methodology. which should also serve to connect the various pieces presented across Chapters 7, 10, 11, 12, and 13. 167. Section 13.1. Page Please verify and. if found incorrect, provide the proper references 13-1, Paragraph 1. where logic-tree branches are presented. Line 1 168. Section 13.1. Page Please check whether this report section actually applies the Miller and 13-1, Paragraph 1, Rice (1983) methodology. Otherwise the reference to that paper here is Line 2 misleading and should be dropped. Consider whether Keefer and Bodily is an appropriate reference for the type of distribution resampling applied here. 169. Section 13.1. Page The reference to the book by Ang and Tang (2007) is too general. 13-1. Paragraph 1. Please confirm that this reference is the appropriate one for the discrete Line 3 representation of scaled Chi-squared distributions, and if so, please cite page number(s). 170. Section 13.2, Page Theo here appears to be the same as in Eq 5.4.1-1 on page 6-20 13-1, Paragraph 1. (October 2014 draft), and in Section 13.4, second to last line on page Lines 5-6 and Eq. 13-13-3 If that is correct. please replace cr with crss throughout the chapter 1 for consistency with terminology used elsewhere in the report. 171. Section 13.2. Page Please discuss or reference the "results" being referred to in the 13-1, 1st Paragraph of statement "results that show a very weak negative correlation between t Section, 10th Line and 1!J". 172. Section 13.2, Page Section 7 .3.1 does not provide the definitions of the scaled chi-squared 13-2. Paragraph 1. distribution as claimed. Please provide a correct reference. Line 1: 173. Section 13.2, Page The first equality is flawed: no non-constant function of xis equal to the 13-2, Paragraph 1, same function of x'. This abuse of notation is confusing. If it is necessary Equation 13-3 to introduce the first equality, please clarify its meaning. 174. Section 13.2, Page In equation 13-4, c is defined as a function of sigma-squared, treated as 13-2. Paragraph 1. a deterministic variable, but sigma is a random variable in Equation 13-3. Equations 13-4. 13-5. The same applies to the definition of constant kin Equation 13-5 The substitution of Equations 13-4 and 13-5 into 13-3 leads to incomprehensible results. Please define and use notation that clearly distinguishes between the random variable and the deterministic variable that represents a distribution model parameter. This should be done in a manner that maintains consistency with the rest of the report notation. 175. Section 13.2, Page Please indicate what typical numerical values of c and k are. 13-2. Paragraph 1. following Eqn 13-5 176. Section 13.2. Page Please provide an explanation of what a "weighted composite CDF" is 13-2, Paragraph 2, and how it was computed. Also, please confirm that the composite CDF Lines 5-6 is for lflss only (as indicated in the legend of Figure 13-4). Finally, please explain why composite CDF for Cj)ss is created and presented in this chapter. not in Chapters 11. 12. Also note that the sentence beginning on line 5 ("Using weights ... ) is garbled-please revise to clarify its meaning. 177. Section 13.2. Page Please add text to explain how the weighted composite CDF for cJ>ss was 13-2, Paragraph 2, used to form the composite distribution of total sigma given in Table 13-Line 5-7 1. 178. Section 13.2, Page Please provide a reference for the statement made in this sentence. If it 13-2, Paragraph 2, is based on SWUS's own investigation, then please include, at a Sentence 6 minimum. a supporting figure for this conclusion. 179. Section 13.2, Page Please confirm that variance, not standard error, was the quantity that 13-2, Paragraph 1. was used in the analysis throughout this report. Also, please explain Last Line ( Eq. 13-6) how you go from a model of variance to a model (Eq. 13-6) of standard deviation. 180. Section 13.2, Page Also please reference where in the report the basis for Equation 13-6 13-2. Paragraph 1. can be found Last Line ( Eq. 13-6) 181. Section 13.3. Page Please briefly summarize the three uncertainty models being referred to 13-2. 1st Paragraph of in this sentence. and clarify that the models for PVNGS are Oss (or <Jlss.,) Section models (as opposed to 4>) 182. Section 13.3.1. Page Please add text to discuss the need for two alternative models. 13-3. Paragraph 1. Line 2 183. Section 13.3.1, Page In addition to Table 13-2, please also provide a figure similar to Figure 13-3, 1st Paragraph of 13.4 to show how well the composite distribution fits the original Section, Last distribution. c:.,,ntence 184. Section 13.3.2. Page In addition to Tables 13-3 and 13-4. please also provide a figure similar 13-3. 1st Paragraph of to Figure 13.4 to show how well the composite distribution fits the Section, Last original distribu1ion. Sentence 185. Section 13.4. Page Please provide a reference (such as Jayaram and Baker. 2010) for the 13-3, 1st Paragraph of statement "it leads to an increase in the 4> estimates and decrease in the Section, 3rd Line 'estimates", or provide another basis for this statement. 186. Section 13.4, Page According to Appendix R, the analysis was done on the model of CY14 13-3. 1st Paragraph of (Chiou and Youngs. 2014). Please remove "preliminary" and revise the Section, 5th Line date from "2013" to "2014" in the statement "preliminary CY14 (Chiou and Youngs, 2013)" to conform to the discussion in Appendix R. 187. Section 13.4. Page Please change the reference to Shahi (2014 ). here and at other 13-3. Paragraph 1. locations. to reflect the multiple authors of Appendix R Also. please use Line 5 some alternative style for the citation, as the author/year form of citation is only appropriate for an article or report that appears in the reference list, not for an internal reference to an appendix, which is an integral part of the report. 188. Section 13.4, Page Please clarify what the terms "homoscedastic" and "heteroscedastic 13-3. 1st Paragraph of refer to in this context. Section, 6th and 7th Lines 189. Section 13.4, Page Please clarify who conducted the semivariogram analysis (was it the Tl 13-3, Paragraph 1. Team or Shahi et al., Appendix R), and provide a reference that Line 9 describes the semivariogram analysis methodogy. 190. Section 13.4, Page Please explain what normalization factor was used for the normalized 13-3, Paragraph 1, variogram. Please also change the figure caption and the y-axis label of Line 12 Figure 13-6 to reflect the use of normalized variogram. 191. Section 13.4. Page Please specify the amount of reduction in tau that was used to obtain the 13-3. Paragraph 1. 4% increase in total sigma. Third to Last Line 192. Section 13.4. Page Please justify why it is appropriate to change the weights for all spectral 13-4. 1st Paragraph. periods when the analyses of Jayaram and Baker (2010} and Appendix 3rd Sentence R indicate that they are period-dependent. Please also explain how what appears to be a relatively large degree of epistemic uncertainty depending on the dataset that is used to perform the analyses is taken into account. when results are available for only two datasets. 193. Section 13.4. Page Please discuss whether the modified weights (which constitute a skewed 13-4, Paragraph 1. discrete distribution) adequately capture the true shape of the sigma Last Sentence distribution that accounts for spatial correlation in residuals. Please also discuss if the 3-4% increase in mean sigma is justified and if the variance of total sigma is unaffected by the consideration of spatial ,., 194. Section 13.5. Page In previous discussions of these distributions. they were described as 13-4. 1st Paragraph of normal and a mixture of normal without "log" in front of them. It was Section, 1st Sentence relatively clear that this was because the distributions were developed from the within-event residuals, which have natural log units. The use of "log" now can be confusing given these previous discussions. Please explain why "log" is now being used to describe these normal distributions for additional clarity or remove log" and describe that the distribution is on a parameter that has units of natural log. 195. Section 13.5. Page Since <J>ss. not o. was used in Eq 13-1. please justify the decision to apply 13-4. Paragraph 1. the same factors and weights for cp to <J>ss-Line 4 196. Section 13.5. Page Please replace "event-to-event" with "between-event" to be consistent 13-4, 1st Paragraph of with terminology used elsewhere in the report. Section, 6th Line 197. Section 13.5. Page Since <J>ss. not o. was used in Eq. 13-1. please rewrite this sentence in 13-4, Last Sentence terms of 198. Section 13.6, Page Please update the Abrahamson et al. (2014) reference to include the 13-4. Item 1 page numbers of the published manuscript. 199. Section 13.6. Page Please provide the location of publisher for the Ang and Tang (2007) 13-4, Item 2 reference. 200. Section 13.6, Page The date is incorrect. This report is actually Chiou and Youngs, 2013. 13-4, fourth entry But please remove it from references, since the citation in Appendix R is actually of the published paper. Chiou and Youngs (2014) 201. Section 13.6. Page Please update the Chiou and Youngs (2014) reference to include the 13-5. Item 1 page numbers of the published manuscript. 202. Section 13.6, Page As noted in an earlier comment, it is questionable whether this article 13-5, Last item was correctly cited. If the citation is deleted, please also delete this reference section entry and replace with the correct reference. 203. Table 13-4, Page 13-Sigma listed in other tables show an increasing trend with period. Please 9 provide explanation for the decreasing trend shown in this table. Also. at T>= 5 sec. the central branch in Table 13-3 is higher than the central branch in Table 13-4. Please clarify whether cl>s*-f< is supposed to be always lower than <l>ss for all periods (because of the removal of systematic path effect) and whether the above-mentioned reversal is expected. 204. Figure 13-6, Page 13-Please note that the legends are erroneous in both the upper and lower 6 panels: the exponential functions are incorrectly identified with the blue asterisk symbols instead of with the red curves. 205. Figure 13-7. Page 13-The caption refers to "preliminary CY14 model and cites Chiou and 14 Youngs (2013). But Append ix R says that the Shahi et al. analysis is for the published work, not the preliminary model, and cites the published paper Chiou and Youngs (2014). Please correct, and use an appropriate reference to Appendix R rather than the author/date citation of Shahi. APPENDIX L Path Terms for PVNG and Associated Phi _sp-r Model 206. Section L.1, Page L-1, 1st Please explain why path-specific effects are used and why they are Paragraph, 1st Sentence appropriate for modeling the ground motion from California and Mexico earthquakes. It would also be helpful to clarify in this introductory paragraph that cl>sP-R is an alternative model to Oss for representing site-specific within-event standard deviation (that they are mutually exclusive alternative models for PVNGS). 207. Section L.1, Page L-1, Line The notation 4!>sro-* is used here without introduction. Please ensure that 3 notation is defined at the time it is introduced. 208. Section L.2, Page L-1, 1st Please reference the specific dataset(s) from Chapter 5, and explain why paragraph of section only four spectral periods are available and why these four periods are sufficient to conduct the analysis of path terms 209. Section L.2, Page L-1, 1st Please provide full references or previously defined acronyms for the "4 Paragraph of Section. 3rd NGA-West2 GMPES" the first time they are mentioned in the appendix. Line 210. Section L.2, Page L-1, First Please clarify whether every AZ station recorded the same set of CA Paragraph, Line 7 events. If not. please add text to comment how this situation is addressed in Equations (L-3) through (L-8). 211. Section L.2, Page L-1, 2nd Consider saying "for sources in regions" instead of "for regions", to avoid Paragraph of Section. first any misinterpretation that within-region paths are being characterized line rather than region-to-PVNGS paths. 212. Section L.2, Page L-1, 2nd Please give specific reference to the chapter. section. and figure Paragraph of Section, first number(s) where the three regions are defined. line 213. Section L.2, Page L-1, Please justify Eq. (L-2) as representing the average path term. Second Paragraph, Line 4 214. Section L.2, Page L-1, Please define NGMr*-Equation L-2 215. Section L.2, Page L-1, 2nd Please replace "eq(x}" with the correct equation reference. Paragraph of Section. 6th Line 216. Section L.2, Page L-1, 2nd This sentence is redundant (as the same information is conveyed by the Paragraph of Section, 7th parenthetical remark two sentences earlier). If retained, please change Line NGA-W-2 to a consistent abbreviation used throughout report. 217. Section L.2, Page L-2, Please define NSTA;. and NEQKk. Equation L-3 218. Section L.2, Page L-2, 1st Please explain the need to preserve the range of the medians obtained sentence after Eqn L-4 'rom the 4 GMPEs. and be specific about the medians being referred to. Note also that this and the following sentence mix references to "median" and "mean". If this distinction is intended, please clarify; otherwise, please use terminology that consistently treats either amplitudes or log amplitudes as the principal variate. 219. Section L.2, Page L-2, 2°0 Please be specific about the "residuals" referred to in this sentence. sentence after Eqn L-4 220. Section L.2, Page L-2, 2nd Please justify why a minimum of 5 recordings for each station is adequate Paragraph on page. 1st in this analysis and explain why this number is larger than the minimum of Line 3 recordings used in other analyses conducted for the project. Please also explain if those earthquakes with less than 5 recordings were discarded or used in other parts of the analysis. 221. Section L.2, Pages L-2. Please discuss the possibility of mapping the path term into the site term Second Paragraph on and the consequences of such miss-mapping, if significant. page, Line 3 222. Section L.2, Page L-3, 1st Please consider using a font for the lower-case L" subscript that is less Paragraph on page, 1" line apt to be mistaken for a "one", and please write region 1 with a font that after Eqn L-8 is less apt to be mistaken for "lower-case L". 223. Section L.2, Page L-3, 1st For completeness, please provide the equation for the standard error of Paragraph, first 2 lines after he mean path terms. Eqn L-9 224. Section L.2, Page L-3. 2nd Please explain why the value for T = 0.2 sec was not used in deriving the Paragraph on page. second central path term when Figure L.5 shows that it is similar to the other line after Eqn L-10 periods. and also why the average of the few available periods is an appropriate representation for all periods. 225. Section L.2, Page L-3. 2nd Please consider removing the discussion of logic-tree branches and Paragraph. 3rd Sentence weights and reserve this discussion instead for the report section on the appropriate logic-tree models. It would seem appropriate to discuss the high and low uncertainty bounds, but the evaluation of the central, low, and high values should be presented in the discussion of the logic-tree models 226. Section L.2, Page L-3. 2nd Please explain why T = 02 sec was not used for the shorter periods and Paragraph, 4th Sentence why T = 2 sec was not used for the mid-periods, given that additional uncertainty was added for periods greater than 2 sec. It appears that the entire uncertainty model is based primarily on only two spectral periods. Please explain the justification and basis for the path terms. given that essentially only two spectral periods are used in the assessment 227. Section L.2, Page L-3. Please provide rationale for the need for additional epistemic uncertainty Second Paragraph. 2"d to 'or T > 2 sec. and for the approach by which that additional epistemic last sentence of section uncertainty is determined. Also, please explain why it is not needed for T < 2 sec. 228. Section L.2, Page L-3. Please clarify if the uncertainty in the path term due to the small sample general size and small magnitude range (all but 2 data point are from M<5.2 events) of AZ data needs to be incorporated. 229. Section L.3, Page L-4, 1st Please reference Figure L.8 for the statement 'The ci>sr-R (T) at a period of Paragraph, last Sentence 0.2 sec was not used in deriving the central model due to the large variability in the values obtained for the 4 GMPEs at this period and because sources in regions 1, 2. and 3 do not contribute significantly to he hazard at short periods. 230. Section L.3, Page L-4, 1st Please explain why the mean estimate. including the 0.2 sec value. is not Paragraph, last Sentence appropriate to use (even though the variability might be larger). If indeed he hazard is not impacted at T = 0.2 period from the California/Mexico earthquakes, then that should be sufficient to ignore it, but then that leaves only three periods (all defining a slope) to describe what happens at T < 0.5 sec and T > 2 sec. Please explain the justification for assuming a constant value of <JlsP-R beyond the limits of the observations. when all hree of the observations defines a frequency-dependent slope. 231. Section L.3, Page L-4, 1st Please cite the specific section and figure(s) of the report where it is Paragraph, last Sentence demonstrated that hazard at 0.2 sec is not impacted by sources in regions 1, 2, and 3. 232. Section L.3, Page L-4, 2nd Please justify why a scaled chi-square distribution is appropriate and Paragraph. 1st Sentence provide a reference for this distribution and the related equations (or reference a section of the report where the issue is treated). Although the discussion of low and high values is appropriate. please consider removing any discussion of logic-tree branches and reserve this assessment for the discussion of the logic-tree models. 233. Section L.3, Page L-4, 2nd Please expand the discussion of the COV with equations or additional text Paragraph. 2nd and 3rd (and rewrite for better clarity) to show how the COV of 0.17 was Sentences estimated. Also please ensure that a consistent notation for coefficient of variation is used throughout the report. 234. Section L.4, Page L-4 Please provide missing references APPENDIX M Phi_ss Models for DCPP 235. General Section 11.3 refers to Appendix M for the Tl Team's technical basis of giving 0 weight to the magnitude-dependent Oss branch. However, such basis is not yet provided in this Appendix. Please add details of the technical evaluations that support the selection of O branch weight for the magnitude-dependent-IJ>ss branch. 236. Section M .1, Page M-Please confirm that the acronyms ASK14, BSSA14, CB14, and CY14 1, 1st Paragraph, 2nd are defined by their full citations the first time they are used and verify Line that they are included in the list of acronyms. 237. Section M.1, Pate M-"CA" should be spelled out as "California", and should be accompanied t. 1"' paragraph, line 3 by the name of a specific dataset that has already been defined and listed in a table of data sets elsewhere in the report (and that table should be referenced here). The specific dataset name should be used consistently throughout the report. 238. Section M .1, Page M-Please explain why non-NGA data from regions other than Taiwan (such 1, First Paragraph, as the Japanese data set used in the PAGASUS project) are not Line 3 considered in this project. 239. Section M.1, Page M-Please indicate whether the terms "site terms and single-station within-t. 1st Paragraph. 5th event residuals" have been defined in the main report prior to being Line mentioned in Appendix M. If not. these terms require a specific reference to a section in the report or another appendix for their definition or they should be defined when first used in Appendix M. 240. Section M .1, Page M-Please indicate how the site terms and single-station within-event 1. 2nd Paragraph, 1st residuals were calculated from the entire database for CB14. which only and 2nd Lines fit an average anelastic attenuation term with data from distances of 80-500 km (i.e .. the more distant data was not used to develop all of the parameters in the GMPE and, therefore, do not necessarily have unbiased between-event or within-event residuals beyond 80 km}. 241. Section M. t. Page M-Please provide the justification and basis for the specific magnitude and 1. 3rd Paragraph. 1st distance ranges that were selected. Sentence 242. Section M. t. Page M-Please describe the specific <Jlss terms that are referred to in this 1, 3rd Paragraph, Last sentence, and explain why this sentence does not contradict the Sentence statement made in Section 11.3 (Page 11-2, Second Paragraph) that "For the global data set, a magnitude-dependence in the Oss is not seen". 243. Section M .1, Page M-Does this wording mean that the Lin et al dataset has been 1. 4 lh paragraph. 1 sl superimposed on each of the NGA-West2 datasets? Are the red circles sentence to denote "Taiwan" representing part of the NGA-West2 datasets. or are these from Lin et al., or both? Please clarify. 244. Section M. t. page M-Please replace the lower right plot with the data distribution plot for t. 41to paragraph. and CY14. Also. please check all the plots for accuracy: it seems odd. for Page M-5, Figure M.1 example, that the CB14 plot shows only a handful of Italy data and no Japan data at all. 245. Section M.2. Page M-This sentence seems to have a missing word. Please rewrite to make its 2. 1 "' sentence meaning clear. 246. Section M .2, Page M-Please provide plots similar to those in Figure M.4 for a wider range of 2. 1st Paragraph. 3rd spectral periods to more thoroughly document the magnitude-dependent Sentence Oss model. 247. Section M.2. Page M-Please consider changing the word "variances" to "<Jl<ss" for clarity. 2. 1st Paragraph. end of 3rd Sentence 248. Section M.2. Page M-2, 1" Paragraph, Please consider a rewrite of this sentence for accuracy and clarity. Lines 4 and 5 249. Section M .2, Page M-Please describe how the estimated <Pss was smoothed over periods 2, First Paragraph, given estimates at only 5 periods. Lines 6 and 7, Figure M.3 250. Section M.2. Page M-Please provide a justification and basis for using only a magnitude-2. 2nd Paragraph, tst dependent <Jlss model and not a model that is dependent on both Line magnitude and distance. 251. Section M.2. Page M-Please correct "M.4" to "M.5". 2, 2nd Paragraph, Line 5 252. Section M.2, Page M-Please also reference Table M.2 for the a and b coefficients in Equation 2, 2nd Paragraph, (M-1) and explain how the "high" and "low" values in Table M.2 were Last Sentence determined Although Table M.2 is referenced in the next section. because the a and b coefficients are presented here. their tabulated values should be referenced. 253. Section M.3, Page M-Please carefully review this sentence for accuracy and reword for clarity. 3. First Paragraph. Lines 1 and 2 Dr. Carola Di Section M.3, Page M-Please provide the technical basis for selecting 0.12 as being Alessandro 3. Second Paragraph, representative. Please also clarify whether hazard is sensitive to the Line 4 COV value and if there is significant uncertainty in selecting the value 1 .. 255. Section M.3, Page M-Please add text to discuss the evidence and implication of the 3, Second Paragraph, magnitude-independence of COV, particularly for evaluating the Line 4 epistemic uncertainty in the magnitude-dependent <Jlss-256. Section M.3, Page M-Please provide justification for the use of a chi-square distribution and 3, 2nd Paragraph, provide a reference to this distribution and the related equations. Last Sentence 257. Section M.3, Page M-Please add text to provide a source of or derivation for the relationship 3, Second Paragraph, = 2

• COV(<llsss). last sentence 258. Section M.4. Page M-Please provide the missing references. 3, References 259. Table M.1, Page M-4 Please provide another table that lists the number of earthquakes and recordings for the M5.5 and greater database. Please also indicate that these statistics are for sites with at least 3 recordings. 260. Figure M.2, Page M-6 Please explain why not all of the common spectral periods included in the NGA-West2 GMPEs are included in Figure M.2.

261. Figure M.3, Page M-7 Please explain why the values for the models and their averages are shown for only five spectral periods in Figure M.3. 262. Figure M.5. Page M-8 Please explain why only a subset of the available spectral periods for the NGA-West2 GMPEs are used and why there is no value at 10 sec period; whereas, this period is shown in other figures. 263. Figure M.8. Page M-Please explain why not all of the common spectral periods included in 11 the NGA-West2 GMPEs are included in Figure M.8. 264. Figure M.9, Page M-Please explain why the values for the models and their averages are 12 shown for only five spectral periods in Figure M.9. 265. Figure M.10, Page M-Please explain why not all of the common spectral periods included in 13 the NGA-West2 GMPEs are included in Figure M.13 266. Figure M.10. page M-Because there are two global datasets employed in Chapter 11 and 13 Appendix M, the caption, if it alludes to "the global dataset," the text should make it clear that the "global dataset" referenced here is the one specifically used to derive the epistemic uncertainty in Oss (which is distinct from the other global dataset specifically used to derive the central oss model, for which the magnitude-dependent branch does not exist). APPENDIX N Phi_ss Models for PVNGS 267. Section N. 1. general It is potentially confusing that ci>ss and <J>sr.R are discussed in separate comment appendices (N and L, respectively), even though they seem to be mutually exclusive alternative branches of the same logic-tree node. Please provide some connective discussion to clarify this relationship. 268. Section N. 1, Page N-Please reconsider the use of the term "proponent" in this context, as it 1, 1st Paragraph of may cause confusion as to whether the proponent is an outside expert or Section, 1st Line is the Tl Team. 269. Section N.2. Page N-Please quantify what is meant by "important" and provide a specific 1. 1"' paragraph, line 2 (section, figure number} reference to the part of the report where these deaggregation results are documented. Also note the misplaced word "consideration". 270. Section N.2. page N-Please reference the precise dataset names established and tabulated 21 1 sl paragraph, line earlier in the report. and the section number where they were defined. 4 271. Section N.2, Page N-Please explain why the California database used for DCPP is not also a 1, 1st Paragraph of viable dataset for regional Arizona sources. Section, Last Sentence 272. Section N.2.1, Page N-1, Please explain why the use of 3 recordings per station is sufficient to 1st Paragraph of Section, define a site term (especially since 5 recordings were used for other 1st Line aspects of the study as reported elsewhere in the report). 273. Section N.2.1, Page N-1, Please replace Lin et al. (2010) with Lin et al. (2011 ). 1st Paragraph of Section, 2nd Line 274. Section N.2.1, Page Judging from the identical values of N.1 and M.1, the global dataset N-1. 1*1 Paragraph, used in this Appendix is the same as the dataset used in Appendix M. Is Lines 6 and 7 it necessary to repeat the same plots and table here (an issue because of the two appendices instead of one)? It will also help if each dataset is precisely defined and given a unique identifier early in the report and referred to consistently by that identifier thereafter. 275. Section N.2.1, Page The language on average of 1,200-1 , 700 recordings 1,460 recordings N-1 . 1 ,, paragraph. from 72-106 earthquakes" is incomprehensible as written. Please clarify. Lines 5 and 6 276. Section N.2.1, Page Same comments about Figure M-1 are also applicable to Figure N.1 N-1 , 1" Paragraph, Lines 7 (Figure N.1) 277. Section N.2.2, Page Please reference the precise dataset names established and tabulated N-1 , 1" paragraph, earlier in the report, and the section number where they were defined. lines 3-4 278. Section N.3.1, Page There appears to be a trend with magnitude when the entire magnitude N-2, 1st Paragraph of range is taken as a whole. Please provide a quantitative definition of Section, 3rd Sentence what is meant by "significant" and how this definition supports the Tl Team's assessment of assuming magnitude-independence of Oss. 279. Section N.3.2. Page Please see previous comments regarding justification of the use of a chi-N-2. 1st Paragraph of square distribution and the specific value for the COV. Please also Section, 2nd and 3rd provide a basis for the "assumption" that the COV for the European data Sentences is the same as for the global data. 280. Section N.3.3, Page Please explain the difference in the oss model (derived from the same N-2. First Paragraph global dataset using the same methodology) between the greater AZ (Table N.3) and the DCPP (Table M.2). Please also explain the use of different assumption about period dependence for smoothing across periods (there is no period dependence for AZ). 281. Section N.3.3. Page Please see previous comments regarding use of the chi-square N-2. 1st paragraph of distribution and the specific value for the COV. Please also clarify section, line 2-4 whether hazard is sensitive to the GOV value and whether there is significant uncertainty in selecting the value. 282. Please provide a reference to the sensitivity studies that show the Section N.4, Page N-magnitude and distance ranges that control the hazard. 2. 1st Paragraph of Section, 1st Sentence 283. Section N.4, Page N-2. Please reference Figure N-6 for a definition of regions 1, 2, and 3. 1st Paragraph of Section, 3rd Line 284. Section N.4, Page N-Appendix L refers to records in the distance range 200-500 km (section 2, 1" paragraph of L.2). Please explain why a different range is used here. Same comment section, line 4 applies to Line 3 on next page, and Line 3 of section N.5. 285. Section N.4, Page N-Please explain why this renders the CB14 model unusable at large 2. 1st Paragraph of distances Section, 2nd Sentence 286. Section N.5, Page N-Please see previous comments on justification of the chi-square 3, 1st Paragraph of distribution and use of the specific value of the COV, and the Section, 3rd and 4th presentation of logic-tree branch weights. Sentences 287. Section N.5, Page N-Please discuss the cause of the decreasing trend of i!lss with period at 3. First Paragraph. large distances (i.e .. for sources in Regions 1, 2. and 3), as shown in Lines 7 and 8 Figure N.8. 288. Section N.6, Page N-Please correct the date of this publication to 2014a to agree with the 3. 2nd Reference published date of the manuscript 289. Section N.6. Page N-Please correct the date of this publication to 2014b and include the 3, 3rd Reference volume and page numbers of the published version. 290. Table N.3. Page N-6 Please correct the heading of the second column from 'CA data' to 'European data'. 291. Table N.1, Page N-5, Please clarify whether this table also includes the Taiwanese recordings Caption from the Lin et al. (2011) study. 292. Figure N.5, Page N-Please explain why only five periods are shown in this figure. 10 293. Figure N.7, Page N-Please check the accuracy of these plots. 12 294. Figure N.8, Page N-Please correct the caption to indicate that the figure is for sources in 13, caption Regions 1, 2, and 3 (not 4). APPENDIX R Spatial Correlation 295. General Please consider formatting this appendix for consistency and visual uniformity with the rest of the report (font: section. equation and page numbering style, etc) 296. Abstract. Page 1. Line Please consider revising this sentence to reflect the fact that only the 7 model of aleatory variability was refitted. the coefficients of the median relation were fixed to the values estimated by Chiou and Youngs (as stated in Section 3, Page 4, First Paragraph). 297. Section 1 . Page 1 . Please consider changing the word "prediction" to "modeling. First Paragraph. Last Line 298. Section R. 1. Page 2. o, appears to be the same as what is elsewhere in the report called r. 1 *1 paragraph. Line 8 Please make changes here. and elsewhere in the appendix. to ensure that the notation is consistent throughout the report. 299. Section R. 1. Page 2. Please clarify the importance of these two sentences in the context of 1st Paragraph. last 2 the present study. and clarify whether "regions" refers to spatial regions sentences (e.g .. California or Japan) or regions in ground-motion parameter space (e.g., ranges of magnitude and distance). 300. Section R. 1. Page 2. This sentence is confusingly worded because it does not indicate for 2"c paragraph, 2rd what pairs of things correlations are being modeled. Please reword for sentence clarity (for example. "models the correlation of ground motion intensity between sites ... "). 301. Section R. 1. Page 2. Please quantitatively define what is meant by "significantly". 2nd Paragraph. 14th Line 302. Section R.1, Page 2, Please replace "NGA West 2" with "NGA-West2" to be consistent with 2nd Paragraph, 17th the acronym used by the NGA project and used elsewhere in the report Line and appendices. 303. Section R.1, Page 2, Please change this citation to "(Ancheta et al., 2014)" to be consistent 2nd Paragraph. Last with the published journal article. or alternatively reference both the Line PEER reoort and the iournal article. 304. Section 2. Page 3. The statement that a magnitude-dependent model is "closer" to the truth First Paragraph, 1" than the magnitude-independent model seems to contradict the Tl sentence Team's assessed branch weights in the GMC logic tree (equally weighted in Fig 11.1. 12.1. 12.2, and binary weighted in Fig 10.1 ). Please revise or explain how this sentence is consistent with the Tl Team's assessment of these two alternatives. Please also provide a reference to publications by the cited "ground-motion modelers" that suggest magnitude dependence. 305. Section R.2, Page 3, Please describe what simplifications were made to the Chiou and 2nd Paragraph, 1st Youngs (2014) variance model for the present study. Sentence 306. Section R.2, Page 3, Please define what the symbols "s" and "t" refer to in Equations (3) and 2nd Paragraph. 3rd (4). Sentence 307. Section R.2. Page 3. It might be useful to clarify parenthetically that "s" and "s prime" 3rd Paragraph, 4th mentioned here is not the same as "s" in Eq. (4). Line 308. Section R.2, Page 3, Please justify why the equations for "r" given by Jayaram and Baker 3rd Paragraph, 9th (2009) are also appropriate for the within-event residuals of CY14. Line 309. Section R.3, Page 4. Please explain why the results of Jayaram and Baker (2010) and Hong 1st Paragraph. 2nd et al. (2009) are robust enough to permit assuming that the CY14 Sentence coefficients will not chance. 310. Section 3. Page 4. This equation (Eq. 8) seems to be a duplicate of Eq. 2. Please review it First Paragraph. Line and make clarifications as needed. 8 311. Section 3, Page 4, Please review whether "o ** " in these equations should really be i::as", and Second Paragraph, consider clarifying the intent of these equations. Lines 3 to 5 (Eq. 9 to Eq. 10) 312. Section R.3. Page 4. Please provide a published statistical reference for Eqs. (9), (10), and 2nd Paragraph. (11 ). Equations (9) to ( 11) 313. Section 3. Page 4. Please justify the assumption of non-correlation in light of the presence Third Paragraph. of a site-specific term, which could induce correlation between residuals Lines 3 and 4 across different events recorded at the same site. 314. Section R.4. Page 5. The standard deviations derived without considering spatial correlation 2nd Paragraph. 1st should have been similar to those obtained by CY14 Please show that Sentence this is the case or, if not, why not. 315. Section R.4, Page 5, Please clarify whether "these results" refers to the homoskedastic or 3rd Paragraph, 1st heteroskedastic results, or both. Line 316. References, page 5, 4'h reference Please provide a volume number for this reference. 317. References. Page 6. Please update this reference to include volume and page numbers. 3rd Reference 318. References, Page 6, Please provide a more complete reference (e.g., conference date, 6th Reference conference proceedings title, publisher, etc.). 319. Table 1, Page 7, Please clarify that these are "standard deviation model" coefficients, and Caption not median model coefficients. 320. Table 2. Page 8. 5th The value "0.367" appears to be a typo. Please verify this value and Row, 3rd Column revise accordingly. January 5, 2015 Dr. Carola Di J\ lessandro SWUS Project Manager GeoPentech, Inc. 525 N. Cabrillo Park Drive, Suite 280 Santa Ana, CA 9270 I

Subject:

Participatory Peer Review Panel Letter No. 2: Rev.0 Report, Southwest United States Ground Motion Characterization Level 3 SSHAC Project

Dear Dr. Di Alessandro:

This letter provides comments and recommendations of the Participatory Peer Review Panel (PPRP) for the SWUS Project Report, Rev.0. Here we address Chapters 6, 8, 9, and 14, and Appendices H. I, J, K, 0, and Q. Our Letter No. I (dated December 13, 2014) already provided comments on Chapters 7, 10. 11, 12, and 13. and Appendices L. M, N, and R. We have not yet had the opportunity to thoroughly review the remainder of the report, some of which is not yet available to us at this time. It should be appreciated, therefore, that the portions of the report considered in this letter may be subject to further comment once the PPRP has reviewed the remainder of the report. The review comments are tabulated by chapter and identified by section. page, paragraph, sentence or line number, and table or figure number where appropriate. Each comment in the review is assigned a unique number for reference. Comments transmitted with Letter No. I were numbered 1-320, and the numbering of comments transmitted with the current letter start with 321. The table includes an additional column in which the responses of the TI Team may be recorded. The review is not intended to be editorial, but we do call attention to stylistic or grammatical concerns in instances where they substantially affect clarity or may introduce ambiguities. The Rev .0 report covers the full scope of the evaluation and integration efforts of the Tl Team. The review comments from the PPRP are intended to help the Tl Team clarify and expand as necessary the technical basis and justifications for the models and weights used in the final GMC logic trees. Sincerely, Steven M. Day Chair, PPRP Brian Chiou Member, PPRP Kenneth W. Campbell Member, PPRP I , f // /-* .. *'" Thomas K. Rockwell Member, PPRP Comment Response Table Comment Location in PPRP Comment Summary of Revisions to Report Number Text CHAPTER 6 GMC Models for the Median 321. Section 6. 1 , Page 6-1 , The "base-model GMPEs" are called by other names-e.g., "proponent First Paragraph, First Line GMPES", or "selected candidate GMPEs" (as in the next paragraph of th is section) -in other parts of the report. Please select an appropriate name for these GMPEs and consistently use this name throughout the report and appendices. If "base model" is intended to mean something else in this context, please define this term the first time it is used and include it in the list of terms. 322. Section 6. 1, page 6-1 , Please explain the concept of a "space of GMPEs, or make it clear that paragraph 2, line 2 this is a concept that is going to be fully explained later in the chapter, and reference the section where the explanation is given. It would also be advisable to develop a terminology that distinguishes actual GMPEs from the virtual GMPEs constructed from the common form. as the lack of consistent, distinct terms for these entities is a frequent source of ambiguity in the rest of the chapter. 323. Section 6.2.1, Page 6-1. Please replace "Akkar et al. (2013, 2014)" with "Akkar et al. (2014a,b)" 2nd Bullet here and elsewhere throughout the chapter to indicate that both the original manuscript and the erratum were published in the same year. 324 Section 6 2. 1. page 6-1. Idriss (2014) is referred to here as 114. whereas it is ld14 in the figures 6'h bulleted item and elsewhere in the text. Please make these acronyms consistent. 325. Section 6.2.1, Page 6-1. Zhao and Lu (2011) is not a GMPE, but a method for accounting for 8th Bullet saturation of magnitude scaling. Please summarize how this magnitude scaling is used to construct a GMPE for purposes of the Tl Team's evaluation and provide a more meaningful description and acronym for this model. 326. Section 6.2.1, page 6-2. Please indicate quantitatively what is meant by "large magnitude" in this 1" paragraph on page, context. line4 327 Section 62.1. Page 6-2. Please provide a reference for the finite-fault simulations (e.g .. Appendix 2nd Paragraph on page, J as well as citations to references in the list of references). 2nd Sentence 328 Section 62.1. Page 6-2. Please provide a more complete citation to "Idriss 3rd Paragraph on page, 10th Line 329. Section 6.2.1, page 6-2, Please provide additional justification for the exclusion of 114 at 3'" paragraph on page, distances less than 3 km, beyond its status as an outlier relative to other last sentence GMPEs and simulated data. 330. Section 6.2.1, page 6-2. Please check the magnitude of the Kocaeli earthquake, which is given 4'" paragraph on page, as 7.51 in the NGA-West 2 flatfile. line 2 331 Section 6.2.1. page 6-2. Please include a reference to the report section (and figure number if 5 paragraph in section appropriate) where the sensitivity result cited here is demonstrated. (last on paQe ). Line 1 332 Section 6.2.1. page 6-2. The figure is for a relatively long period (0.5 Hz). so it would be helpful 5'h paragraph in section. here to complete the argument by recalling that the long periods are the Line 4 worst case for hazard sensitivity at this distance range (and to reference the report section and figure(s) where that is demonstrated). 333. Section 6.2.1, page 6-2, Please provide a more precise statement of what is meant by "the last paragraph of page, candidate GMPEs is reasonable for application to DCPP" and provide last line the justification for this judgment, or a reference to the report section where this justification is given. 334 Section 6.2.2. Page 6-3. Please replace "Bindi et al (2014)" with .. Bindi et al. (2014a.b)" here and 3rd Bullet elsewhere throughout the chapter to indicate that both the original manuscript and the erratum were both published in the same year. 335 Section 6.2.2. page 6-3. Please explain more fully the justification for excluding the Bindi et al. 1*1 paragraph of section. (2014) model. or provide specific reference(s) to the section(s) where lines following bullets that justification is fully explained. and explain whether ASB 14 has similar limitations. 336. Section 6.2.3, page 6-3. Please reference more specifically-section number, and figure number 1" paragraph of section, if appropriate-where the sensitivity result cited here is demonstrated. Line 2 337 Section 6 2.3. page 6-3. Please state quantitatively what is meant by "large magnitude" in this 1" paragraph of section, context. Line 3 338. Section 6.2.3, page 6-3, The structure of the final sentence of the paragraph is a little awkward paragraph 1 of section. (particularly its formulation as a rhetorical question). and the expression lines 4.5 "large distance attenuation" is ambiguous in meaning. Please consider rewriting the sentence to improve its clarity and precision. 339. Section 6.2.3, Page 6-3. Please replace "Kashida et al. (2014a)" with "Kashida et al. (2014)" here 2nd Paragraph of and elsewhere in the chapter to reflect the fact that there is only one Section, 3rd Line such reference listed in the references. 340 Section 6 2.3. Page 6-3. Please explain how the California event terms were calculated. or 3rd Paragraph of Section, provide a reference to the report section where the explanation is given. Last Sentence on page 341 Section 6 2 3. page 6-4. Here and elsewhere ... California/Mexico should read "California and paragraph 4 of section Mexico" for clarity. Same in the next paragraph where "southernfcentral" (2'" on page). last line should read "southern and central." 342 Section 6.2.3. Page 6-4. Please include the Phillips et al. (2013) reference in the list of last paragraph of section, references. 2nd Line 343 Section 6 2.3. page 6-4. The strong frequency dependence of Q evident in Figures 6.2 3-2 and 5'h (last) paragraph of 6.2.3-3 increases the differences between California and Arizona Q at 5 section, last sentence Hz (upper left panel of each figure), so please reference the sensitivity studies that demonstrate the absence of hazard significance at 5 Hz for California sources. 344 Section 6 3. general The relegation of part of the hanging wall discussion to Appendix K is somewhat awkward and inefficient. Please consider integration of the material from that appendix into the various subsections of 6 3. 345. Section 6.3, Page 6-5. 1st Please include the Abrahamson and Silva (2008) and Campbell and Line on page Bozorgnia (2008) references in the list of references. 346 Section 6 3. page 6-5, The statement that Rjb implicitly accounts for the hanging wall effect last paragraph of section, could be seen as contradicting the result noted later that the Rjb last sen1ence distance metric alone does not account for the dip-dependence of the hanging wall effect Please modify this sta1ement to note that Rjb does not agree with simulations for shallow-dipping scenarios and reference the sections of the report where this is discussed. 347 Sec1ion 6 3. 1. page 6-5. Please consider whether "moderate" is a better descriptor than 1 sl paragraph' Line 3 "average". in order to avoid the suggestion that this is a rigorous statistical measure. 348. Section 6.3.1, Page 6-5. Please explain why the Rjb-based ASB14 GMPE was not used to 1st Paragraph of Section, evaluate HW effects, given that the Rbj-based BSSA14 GMPE was 4th Sen1ence found to be suitable. 349 Section 6 31. Page 6-5. Please provide a specific reference 1o the report section that describes 2nd Paragraph of the "additional simulations" that were done for the SWUS project. Section, 1st Sentence 350. Section 6.3.1, page 6-6. The phrase "Moves off of the hanging wall" is ambiguous, as it does not 3*d paragraph of section make it clear whether the reference is to distant points still on the (1" on page). line 3 of hanging wall side of the surface projection of the top of the rupture. to paragraph points on the footwall side of the surface projection of the top of the rupture, or to both. Please clarify. 351. Section 6.3.1, page 6-6, The phrase "Moderate magnitude scaling" is ambiguous. Please clarify; 3'" paragraph of section for example, if the intent is to refer to scaling at moderate magnitudes, (1" on page). line 5 of please hyphenate as in the phrase "moderate-magnitude scaling." paragraph 352 Section 6 3. 1. page 6-6. The notion of "magnitude taper" has not been defined. and by itself is 3'" paragraph of section ambiguous. Please clarify. ( 1" on page). 2rd to last sentence 353. Section 6.3.1, page 6-6. The discussions in Appendix J (Pages J-41 and J-42) and Appendix K 3*d paragraph of section (Section K.1.2) suggest that the magnitude tapers of ASK 14 and CB14, (1" on page). second to but not CY14, are too strong compared to the magnitude scaling of the last sen1ence HW effect revealed by the simulated data. Please revise this sentence to reflect the conclusions described in Appendix J and Appendix K. 354 Section 6.3.2. Page 6-6. At this point in the chapter the Rjb-based models have not been 1st Paragraph of Section, eliminated as being inappropriate. Please explain why the Rjb-based 2nd Sentence models are not used in developing the HW model. 355 Section 6.3.2. page 6-6. The scaled-backbone approach has not been defined nor is a reference 1" paragraph of section, cited. Please correct this. Line 4 356. Section 6.3.2, Page 6 -6, To avoid misinterpretation. please include text to note that, although a First Paragraph. Last magnitude taper was not explicitly included, Eqs. (6.3-1) and (6.3-2) still Sentence provide a magnitude scaling of the HW effect. as was explained in Appendix J (Page J-42). 357. Section 6.3.2, Page 6-6. Please clarify how the total hanging wall effect is to be modeled by the 3 2"" paragraph of section, equations (e.g .. is it the product of the three factors defined in these Eqns 6.3-1.2,3 equations?). and also define the variable "W". 358 Section 6 3.2. Page 6-6. Comprehension of this sentence depends upon familiarity with Appendix 3'" paragraph of section. K. For example, it does not make sense to say "Five equally weighted line 1 alternative HW factor models were developed .... ",because. logically. models have to be developed before they can be assigned weights. Nor is it clear what is meant by equal probability of the C1 coefficient. Please rewrite and expand the text to make this section sufficiently self-contained to be understandable. 359 Section 6 3.2. Page 6-6. The terminology "weighted factors" in Lines 2 and 3, is a source of paragraph of section. confusion. and without familiarity with Appendix K, the sentence is sentence incomprehensible. Please reword and expand for clarity. and give a more specific reference to the relevant appendix subsection(s). Please note that this is a place where the division of the material between the chapter and the related appendix seems especially inefficient. 360 Section 6 3.3. Page 6-7. Please indicate that additional comparison plots similar to Figure 6.3 3-1 1st Paragraph. 4th are given in Appendix K. Sentence 361. Section 6.3.3, Page 6-7. The assessment that Rjb-based HW models are not appropriate for 2nd Paragraph shallow dips is important Please provide an example plot to show that these models are not appropriate and that Rrup-based models adequately model HW effects. and reference where in the report or appendices the discussion of this topic can be found. 362. Section 6.4, Page 6-7. Please explain the following: What does mutually exclusive" mean? Are First Paragraph, Third the candidate GMPEs mutually exclusive? Why is it important to use Line mutually exclusive GMPEs for the characterization of the CBR of median amplitude? What are the impacts on hazard if GMPEs are not mutually exclusive? 363 Section 6.4. page 6-7, 1*' "Sammon's mapping" is called "Sammon's map" in Section 6.1. If there paragraph of section, Line is no distinction between these, please use a consistent terminology. 11 364 Section 6.4. Page 6-7. The term "base model" has not been defined at this point in the chapter. 2nd Paragraph of Please define the term "base model" the first time it is used and include Section, 1st Line it in the list of terms. 365. Section 6.4.1, Page 6-8. Please expand this sentence to explain why a common functional form 1st Paragraph of Section, for all of the candidate models is needed or reference appropriate 1st Sentence sections in an appendix where this information can be found. 366. Section 6.4.1, Page 6-8, Please indicate what is meant by the phrase "induces a distribution of 1st Paragraph of Section, GMPEs", and indicate where in the chapter this concept will be 3rd Line expanded upon. 367. Section 6.4.1, Page 6-8. There could be confusion when the term "models" is used between 1st Paragraph of Section, whether this refers to the candidate GMPEs or to the simulated GMPEs. 7th Line Please select a common terminology for these two types of models and use this terminology consistently throughout the report and appendices in order to avoid confusion. 368. Section 6.4.1, Page 6-8. Please be more specific by what is meant by "scaling". If it refers to the 2nd Paragraph of scaling terms in the GMPEs, please consider replacing "scaling" with Section, 3rd Line "scaling terms" here and elsewhere in the report and appendices. Please also qualify what type of scaling is meant when the term is used elsewhere throughout the report and appendices. 369. Section 6.4.1, page 6-8. Please define NML as an acronym for "normal" here if this is the first 2"" paragraph of section, time it is used and include it in the list of terms. 4 line after Ean 6.4-1 370 Section 6.4.1. page 6-8. Please define the acronym "SS" (implying strike slip) the first time it is 2"d paragraph of section, used and include it in the list of terms. 81h line after Eqn 6.4-1 371. Section 6.4. 1, page 6-8, Please clarify what SS:NML and SS:REV mean and replace "based on 2"" paragraph of section, the scaling in the eight candidate GMPEs" with more precise language. last 2 sentences Also explain why the specific scenarios for estimating SS:REV and SS:NML factors are appropriate and if the results are sensitive to the choice of the selected scenario. Please also explain why the same scenario is appropriate for both DCPP and PVNGS. considering that their hazard is impacted by potentially different magnitudes and distances. 372. Section 6.4. 1, page 6-9, Please indicate what function is being referred to in the statement "this 3*d paragraph of section. function." and by whom it is considered to have the stated flexibility. If (1" on page) lines 2 and this is the assessment of the Tl Team, please say so. and provide the 3. basis for this judgment by demonstrating that Eqs. (6.4-1) and (6.4-2) are flexible enough to capture the full range of scaling of the selected candidate GMPEs. That might entail, for example, showing the misfits to the original GMPEs as a function of magnitude and distance. Also, please discuss whether the misfits to the original GMPEs significantly affect the hazards. or reference the report section where such a discussion is provided. 373. Section 6.4.1, Page 6-9. Please explain why this transformation of coefficients is necessary and 3'" paragraph of section how it leads to squared coerticient terms in Eq. (6.4-2). (1st on page). 3rd Sentence 374 Section 6 4. 1. page 6-9. 3'" paragraph of section Please check the equation. Shouldn't as(7) be squared? (1" on page), Eqn 6.4-2 375. Section 6.4.1, Page 6-9. Please clarify what the phrase the square" refers to with respect to Eq. 3*d paragraph of section (6.4-2) and/or the definition of the model coefficients. (1st on page). 13th Line 376. Section 6.4. 1, Page 6-9, The intended point of this sentence is unclear. Please revise to make it 4'" paragraph of section clear. (1" paragraph after Eqn 6.4-2), 1*1 sentence 377 Section 6 4. 1. Page 6-9. Please justify that the Ztor effects of the ASK14. CB14. and CY14 4'" paragraph of section GMPEs are adequately captured by the common-form models with a8 = ( 1" paragraph after Eqn 0. 6.4-2), 2°0 sentence 378 Section 6 4. 1. Page 6-9. Please describe what the three Ztor values are supposed to represent 4 paragraph of section and how they were used in the regression analysis (e.g .. were they (1" paragraph after Eqn equally weighted or weighted by some other probability distribution). 6.4-2), last sentence Also please revise the reference to the Ztor model of CY 14 to be more specific (e.g., "the Ztor-M relationship developed by CY14"). 379 Section 6 4. 1. 1. page 6-9. The explanation in this section is incomplete. in that it is never explicitly general comment stated that numerical log(Sa) predictions of each GMPE, for the given M and Rx set, are used as data to determine a best-fitting coefficient vecto1 for the common form to that GMPE, nor what fitting criterion is applied. Please make the explanation more complete. This same comment applies to Section 6.4.1.2. 380 Section 6 4. 1. 1. Page 6-9, Please explain what is meant by the phrase "for comparison of the 1st Paragraph of Section, GMPEs" 3rd Line 381. Section 6.4.1.1, Page 6-9, Please explain how predictor variables Rrup and Rjb were determined, 1" Paragraph, first 2 lines given Mand Rx. and clarify who the developers" are (e.g., the NGA-after the bullets West2 developers or the candidate GMPE developers meaning the Tl Team) 382 Section 6 4. 1. 1. Page 6-The phrase " . is only included to constrain the fitted models at large 10, 1"' paragraph, 1" line distances ... " has the connotation that the large-distance scenarios are on page used in a limited fashion in the fitting process. Please clarify and revise this paragraph as needed. 383. Section 6.4.1.1, Page 6-Please provide a reference in the report or appendices where the 10, 1st Paragraph, 3rd definition and calculation of "hazard-relevant" scenarios can be found. Line 384. Section 6.4. 1.2, Page 6-Please clarify who the "developers" are (e.g., the NGA-West2 10, 1st Paragraph of developers or the candidate GMPE developers meaning the Tl Team). Section, 2"* line after the bullets 385. Section 6.4. 1.2, Page 6-Please explain the basis for "assuming" a SO-degree dip and indicate 10, 1st Paragraph of whether the results are sensitive to this assumption. Section, 2"* line after the bullets 386 Section 6.4.2, General To provide more complete documentation. please list the covariance matrices in Appendix H. 387. Sections 6.4.2 and 6.4.3, The method used to generate the simulated GMPEs and project them General comment onto Sammon's maps is new and requires detailed documentation to fully understand the methodology. Please provide more detailed documentation on the generation of the covariance matrices, the simulated GMPEs. and the Sammon's maps, including all related equations, either in Chapter 6 or in an appendix. 388 Section 6.4.2, page 6-10. This short section is mainly devoted to describing the use of section title interpolation to facilitate the estimation of the coefficient correlations. It is not clear what the title "generation of models" refers to. In the subsequent section (6.4.3), model generation seems to refer to the sampling of the coefficient space to create sample GMPEs. so the use of "model generation" as the title of Section 6.4.2 seems confusing. Please consider changes to remedy this confusion. 389 Section 64.2. page 6-10. Please explain the difficulties encountered in estimating the correlations 1" paragraph of section, of the coefficients using the original GMPEs alone, and justify how it is sentences 2,3, and line 5 mathematically possible with the addition of the interpolated GMPEs to better capture the correlations. Also provide the rationale for the interpolation weights selected. and clarify whether the interpolation was done by interpolating the coefficients or by interpolating the ground motion vectors and refitting to the common form. 390. Section 6.4.2, page 6-10, The last set of weights (2/3, 1/2) do not add to 1, while the other two 1" paragraph of section, sets do add to 1. Please review and revise as needed. line 5 391 Section 6 4.2. Page 6-11, Is this approach (for treating the case T>3 sec) mentioned for the first 2"d Paragraph of section time here? If so. please add a paragraph in Section 6.1 so the reader (1" on page). Last are aware of it from the very beginning. Sentence 392 Section 6 4.3. page 6-11. Please add an explanation of what is meant by model generation and 1" paragraph of section how it is done. At this point, for example, there has been no explicit (1" on page), 1" sentence explanation that models in this section are generated by sampling the on page common-form coefficient distribution estimated in the previous step, nor have any necessary assumptions about the joint distribution of the coefficient distribution been explicitly stated. 393. Section 6.4.3, page 6-11, Please clarify what is meant by "for a few scenarios." Doesn't Figure 1*1 paragraph of section. 6.4.3-1 apply to just a single set of predictor variables (i.e .. a single 3*d sentence value each for magnitude. distance. and style of faulting)? In addition. please state what predictor values were used (that information should be in the figure caption as well). 394. Section 6.4.3, page 6-11, Please indicate by whom the judgment was made, and on what basis, 1" paragraph of section, and consider whether "range" is the appropriate term here, as opposed last sentence of to, e.g., distribution" or "center, body, and range" (there are other paragraph instances throughout the report where the usage of "'range" should also be reviewed and revised where appropriate). 395 Section 6 4.3. page 6-11. Please clarify whether the good agreement seen in the example 1*1 paragraph of section. scenario was also observed in all other scenarios important to the last sentence of hazards at DCPP and PVNGS. paragraph 396 Section 6 4.3. page 6-11. Some explanation of the nature of the Sammon's map should precede 3'" paragraph of section. this instance of its application. Please consider doing some 1" sentence reorganization of this section to put the developments in a more logical order. 397. Section 6.4.3, page 6-11, The range of values of the Sammon's map coordinates in Figure 6.4.3-2, 3'" paragraph of sec1ion, for the original GMPEs, is roughly plus/minus 10. This is more than an 1" sentence order of magnitude greater than the range shown in, e.g., Fig. 9.1-3b of Chapter 9. Please explain the reason for the difference Also please explain the reason for the difference in axis labels in different parts of the report. i.e .. "C 1,C2" is used here and in Chapter 9. versus the axis labels In units" shown for seemingly analogous plots in Chapter 8 and Annendix H. 398. Section 6.4.3, Page 6-11, Please explain why there is a trade-off between the "likelihood and an 4'" Paragraph, Last 2 optimized standard deviation", what the sensitivity of the results is to sentences using a fixed standard deviation. and what the rationale is for selecting that value from BSSA 14 over the other GMPEs. 399. Section 6.4.3, Page 6-11, Please describe the Tl Team's reasons for including the simulated data 5'" Paragraph, 1" in the model evaluation, or point to the section where those reasons are Sentence described. 400. Section 6.4.3, Page 6-12, Please provide a reference for the "80% and 20%" proportions of relative 2nd Line on page rates of normal and strike-slip mechanisms for the Arizona sources. 401. Section 6.4.3, page 6-12, Please rewrite this sentence to improve clarity. It is not clear what part of 7'" paragraph of section the analysis was done using the central HW term, nor at what stage the (2'" on page). 2"d and 3'" random HW models are introduced instead. nor why this two-stage sentences analysis method was chosen. 402 Section 6 4.3. Page 6-12, Please provide citations for principal component analysis and Sammon's 9th Paragraph of section (4'" on page). 1*1 maps if they haven't been provided previously in the chapter. Sentence 403 Section 6 4.3. Page 6-12, Please describe the Tl Team's motivation to base the selection of the 9th Paragraph of section representative model on the resulting hazards, and to select the model (41" on page), 2"" with hazard closest to the mean hazard (as opposed to, e.g., the median Sentence or another quantile hazard level). Please also describe the scatter in the hazard from models in the same cell. 404. Section 6.4.3, Page 6-12, Please verify that the simplified SSC models for DCPP and PVNGS 9th Paragraph of section (41" on page), 3" being used are consistent with the final SSC models for these sites. Sentence 405 Section 6 4.3. Page 6-12, Please explain the basis for selecting the "one specific HW model". 9th Paragraph of section (4'" on page). 6'" line 406. Section 6.4.3, page 6-12, The concept of using random HW models in the development of the 9'" paragraph of section Sammon's maps for PVNGS and a random HW model assigned arter (4'" on page), last the selection of a GMPE for each cell for DCPP is unclear. Please sentence provide additional explanation of how this method is applied and why it is needed in order to help the reader better understand the methodology. 407 Section 64.3. page 6-12. Please clarify what is meant by an approximately uniform distribution of 9 paragraph of section hanging wall factors (e.g .. according to Appendix K. the HW factors were (4'" on page), last developed under the assumption of a normal distribution), and why it is sentence important. 408 Section 64.3. page 6-12. Please describe how the outputs of principal component analysis 1 o'" paragraph of section (presumably. a set of 2-D coordinates) are used as inputs for the (5'" on page). 1*1 construction of Sammon's maps. and provide a reference for the "principal component analysis and Sammon's maps" methodology that is being used 409. Section 6.4.3, page 6-12, Please indicate whether the model vector concatenates a set of periods, 1 o'" paragraph of section or a separate model vector is constructed for each of a set of periods. In (5"' on page). 2"d either case. please indicate what set of periods was used. Also please sentence consider changes to emphasize even more explicitly that the vector space is a space of ground motion valued n-tuples. and to draw a clear distinction between this vector space and the space of common-form coefficient vectors used in the model generation stage. 410 Section 64.3. page 6-13. Please rewrite this sentence (and perhaps add additional text) to make 1011' paragraph of section its meaning clear The explanation should clarify that each vector (1" on page). 1" full component is a In( Sa) value for a particular combination of predictor sentence on page variables. The lists of predictor values (for DCPP and PVNGS, respectively) should also be given at this point (e.g., are they the values listed later on 1his page and called "deaggregation bins" or values listed on Pages 6-9 and 6-1 O?) Presumably one of those sets was used in the fitting and the other in model generation. but it is difficult for the reader to figure this out The explanation should also clarify that the analysis is done independently at each period, if that is the case. 411. Section 64.3. page 6-13. Please be precise and consistent in the use of terminology. The symbol 101" paragraph of section "w" in this line is defined as the importance of the scenario. but in the (1" on page). 1" line after next sentence it is call the weight," and later something called Eqn 6.4-4 deaggregation weight" is referenced. If these all mean the same thing, the terminology should be consistent; if they do not, their distinction should be clarified. 412. Section 64.3. page 6-13. This line states that the weights are computed from "the deaggregation." 10'" paragraph of section But this is the first time "deaggregation" has been mentioned in the (1" on page), 2"" line afte1 chapter, so the use of the definite article (indicating something already Eqn 6.4-4 introduced) is very confusing. Please rewrite this statement to make it clear that a new element is being introduced into the analysis. Please also be more specific than just referring generically to "deaggregation" by saying. e.g .. "hazard deaggregation matrix" and by specifying what return periods and spectral periods are used to perform the deaggregation. 413. Section 6.4.3, page 6-13, Please clarify what GMPE distribution is referred to here, and what is 10111 paragraph of section meant by "mean model." For example, is this distribution that of the eight (1" on page). 2*d line afte1 original GMPEs. or of the 2000 virtual GMPEs in the constructed Eqn 64-4 ensemble. and is the "mean model" the virtual GMPE that occupies the position in Sammon's map space that represents the geometrical centroid of the original GMPEs? 414. Section 64.3. page 6-13. The term "deaggregation weight" has not been defined. Please explain 1 o'" paragraph of section how it is related to the deaggregated hazard (e.g., is it some function of (1" on page), 3'd and 4'" the probability of exceedance value at a given ground motion level, or line after Eqn 6.4-4 simply the probability value itself, normalized in some way?). Please also state precisely and quantitatively what was done, and include the defining equation for the deaggregation weight. 415. Section 6.4.3, page 6-13, The statement that the mean of the deaggregation weights" is "used as 10'" paragraph of section w in Eq. (6.4-4) is inconsistent with the subsequent explanation in which (1" on page). 4"' line after this mean is given a different symbol. w_bar. and is used in Eq. (6.4-4). Eqn 64-4 in combination with the number 1/N. to give w. Please rewrite this statement to provide a precise and consistent explanation. 416. Section 6.4.3, page 6-13, Please clarify if the renormalized weights" are used with Eq. (6.4-4) 11 '" paragraph of section instead of the mean of the 10 deaggregation weights referred to in the (2" on page). 3*d line previous paragraph. 417. Section 6.4.3, page 6-13, Please explain how it was determined that the defined deaggregation 11 '" paragraph of section bins" are sufficient for the purpose of determining the scenario weights. (2" on page), 3*d line after Equation 6.4-5 418 Section 6 4.3. Page 6-14 Please explain why only a mean + 3 km increment was used as an 14'" paragraph of section alternative value for Ztor and not also a mean -3 km increment. Please (1" on page), First Line also explain why 3 km was chosen for the increment and whether the alternative value was given a different weight than the mean. 419. Section 6.4.3, page 6-14, The juxtaposition of the statement that "only one Ztor value is used for 14'" paragraph of section the Rjb-based models, with the statement "these models do not include (top paragraph on page), Ztor scaling," seems illogical. If Ztor does not occur as a predictor 1st fu II sentence variable in a GMPE. it is confusing to suggest that "only one value" of that variable was used. Please rewrite this statement for clarity and nrF>r.i<<inn. 420 Section 6 4.3. Page 6-14, It's not clear how the number 384 is obtained. Based on the information 14th Paragraph (1"' given in this paragraph. there are 6 magnitudes. 13 distances. 2 styles paragraph on page), Line of faulting. and 2 Ztor values: 6 x 13 x 2 x 2 = 312. Please clarify. 7 421. Section 6.4.3, page 6-14, This sentence seems redundant with the content of the previous 15th paragraph of section paragraph, except that the cited dimension of 284 for PVNGS is (2r* paragraph on page), inconsistent with the dimension of 384 in the bulleted list in the 1st sentence preceding paragraph and with the dimension cited in the subsequent sentences (also note that PVNGS is misspelled in both of its occurrences). Please clarify and correct. 422. Section 6.4.3, page 6-14, Please explain the reason for the extra step of first projecting the space 15*h paragraph of section using principal component analysis. (2"" paragraph on page), line4 423 Section 64.3. page 6-14. To avoid confusion, please consider rewriting to avoid the ambiguous 15*h paragraph of section "28813841192 .. notation (here, and elsewhere In the report). For example, (2"" paragraph on page), consider the alternative phrase "each model corresponds to a point in N-2"" sentence dimensional space, where N has values of 288, 384, and 192 for the DCPP. PVNGS Model A. and PVNGA Model B cases. respectively. 424. Section 6.4.3, page 6-14, Please provide the basis or reference for the statement "the first two 15*h paragraph of section principal components, however. typically account for about 85-90% of (2r* paragraph on page), the variance". 3*d sentence 425 Section 6 4.3. page 6-14. This sentence appears to misrepresent what is presented above. Please 15th paragraph of section consider restructuring the sentence to begin "As described above. the (2r* paragraph on page), contributions to the difference in the squared Euclidean distances .. ". 41" sentence 426 Section 6 4.3. page 6-14. Please show the values of deaggregation weight for some example M-15*h paragraph of section distance bins and periods. (2"" paragraph on page), last line 427. Section 64.3. page 6-14. Please check the definition of ex Should the second entry in the set be 2 16t11 paragraph of section (not 0.2)? (3'd paragraph on page}. first line after Eqn 6.4-6 428 Section 6.4.4. page 6-14. Please explain why an ellipse was chosen. in what sense the ellipse is 1*t paragraph of section. best fitting, and why the best fitting ellipse is always horizontally 2"d sentence oriented. 429. Section 6.4.4, page 6-14, The correct expression here is "convex hull" (not "complex"). Please 1" paragraph of section, make that correction, define what it is, and consider whether the ellipse 2"" sentence is fit to the boundary curve of the convex hull. 430. Section 6.4.4, page 6-14, The acronym "GMPE" is used indiscriminately in this chapter, 1*t paragraph of section. sometimes to mean specifically the original set of eight published 2"d sentence GMPEs. other times to refer to members of the ensemble of constructed virtual GMPEs. Please clarify the meaning of GMPE used here and be consistent in uniquely describing which definition of GMPE is meant when it is used elsewhere in the chapter. 431 Section 6.4.4. page 6-14. The expression "uncertainty models" is used here without definition and 1*1 paragraph of section. the resulting text is ambiguous and confusing. Please rewrite for clarity. 2"d sentence If the set of GMPEs formed from the original GMPEs with added epistemic uncertainty is going to be used repeatedly, please introduce an unambiguous terminology and use it consistently. 432. Section 6.4.4, page 6-14, Since it has not been explained how the ellipse is going to be used, the 1" paragraph of section, significance of scaling it up is not clear at this point in the narrative. Nor 3'" sentence is the parenthetical comment comprehensible (e.g., capture the full range of what?). Please rewrite this discussion to clarify the reasoning behind centering and scaling the ellipses this way. including the reasoning behind the choice of the factors 1.5 and 0.5. 433 Section 6.4.4. page 6-14. This sentence is incomprehensible. Please rewrite it for clarity. 1*1 paragraph of section. last sentence 434. Section 6.4.4, page 6-15, Please state what data set(s) the residuals are calculated for, and clarify 2"" paragraph of section whether the between-event residuals are also weighted by (1" paragraph on page). deaggregation weight to emphasize the magnitudes that are more line 1 important for hazard and. if they are not weighted, please explain why. 435 Section 6.4.4. page 6-15. Please provide additional discussion of the method for producing the 2"" paragraph of section ellipses and justify the 5 selected residual values used to define the (1" paragraph on page), intersection points between the residual contours and the ellipses. line 2 436. Section 6.4.4, page 6-15, Please clarify the meaning of "uncertainty models" (see earlier comment 2"" paragraph of section suggesting use of a consistent, unambiguous expression for those (1" paragraph on page), 3*d sentence models) 437. Section 6.4.4, page 6-15, What is meant by the phrase "broadened to capture this range"? That is, 2"" paragraph of section please state which new contours are then selected in that case. (1" paragraph on page), 3'" sentence 438. Section 6.4.4, page 6-15, Please explain what is meant by the ambiguous phrase "center of the 2"" paragraph of section original GMPEs." If this refers to the centroid point in Sammon's map (1" paragraph on page). coordinates. please say so. line 6. 439. Section 6.4.4, page 6-15, 2"" paragraph of section Please give the final number of selected representative points. (1" paragraph on page). last line 440. Section 6.4.4, page 6-Please be specific about the quantity to which the term "range" 15, 3'" paragraph of refers. Please also explain how the range in the location of points on section (2"" paragraph the Sammon's map relates to the range of this quantity. In addition. on page) please explain why the range of Sammon's map coordinates in Figure 6.4.3-2 is larger by more than an order of magnitude than the range of Sammon's map coordinates in Figure 6.4 4-1 and all the other Sammon's map figures in the report. 441. Section 6.4.4. page 6-15. This is the first time the expression "epistemic models" has been used. 3'" paragraph of section Please clarify what is meant by this expression (in contrast to previous (2" paragraph on page), references simply to "models or "GMPEs"). 2"" sentence 442. Section 6.4.4. page 6-15. Please be specific and quantitative about this procedure. For example. 3'" paragraph of section how are the rescaled ellipses defined in the case noted? (2r paragraph on page), 2"" sentence 443. Section 6.4.4, page 6-15, Please be clear that reference is being made to the original GMPEs and 3'" paragraph of section to those GMPEs with the added epistemic uncertainty terms. (2" paragraph on page), sentence 444. Section 6.4.4, page 6-15, Please explain how the model screening was done and what models 3'" paragraph of section were removed during the screening process. paragraph on page), 4'h sentence 445. Section 6.4.4, page 6-15, Please explain the basis for the assumption that "The selected points 4 paragraph of section are assumed to be representative of their neighborhood in ground-(3" paragraph on page). motion space". Line 1 446 Section 6.4.4. page 6-15. Please clarify whether the word "boundaries" means boundaries of the 4'h paragraph of section outer Voronoi polygons. and state the scale factor used to define the (3" paragraph on page). fourth ellipse. Line 3 447. Section 6.4.4, page 6-15, Please explain the reason for not simply using the selected point to 4'h paragraph of section represent the models in a Voronoi cell. (3" paragraph on page). line4 448 Section 6.4.4. page 6-15. The meaning of the phrase "closeness in hazard space for each cell" is 4 paragraph of section not clear. For example, closeness of what to what? Please consider (3r>:1 paragraph on page). whether this sentence can be deleted and the word "therefore" deleted 4'" sentence from the following sentence. 449. Section 6.4.4, page 6-15, Please explain in what sense the hazard curve for the selected model is 4 paragraph of section "closest" to the mean. (3" paragraph on page). 6'h sentence 450 Section 6.4.4. page 6-15. Please explain why selection of this "closest" point as a representative ol 4'" paragraph of section the cell does not contradict the first sentence of the paragraph, which (3" paragraph on page), appears to say that the points on the ellipses selected" in the previous 61" sentence paragraphs "are assumed to be representative of their neighborhood." 451 Section 6.4.4. page 6-15. Please explain how to interpret the x-and y-axis scale of the Sammon's 4*h paragraph of section map. as was requested by many workshop participants during (3" paragraph on page), Workshops 2 and 3 and recommended by the PPRP in its comment last line letters on the workshops. 452. Section 6.4.4, page 6-15, The phrase "distribution of HW branches for the selected representative 5'" paragraph (4:* branches" is awkward. Please consider rewriting this phrase to improve paragraph on page), 1" its clarity. line 453. Section 6.4.4, page 6-15, Please explain why this distribution of HW terms does not contradict the 5'" paragraph of section statement in Section 6.4.3 that "the central hanging wall branch is (4"' paragraph on page), applied for the Sammon's maps." That section also notes that "later the sentence DCPP base models are assigned a random HW models[sic)," but there appears to be no mention of that addition in the intervening text The treatment of the HW terms requires clarification. 454 Section 6.4.4. page 6-15. 5'h paragraph of section (4'" paragraph on page), Please state the rationale for the assessment given in this sentence last line 455 Section 64.5. page 6-15. Please explain the need to assign a weight to each selected model Also 1*1 paragraph of section. note that the sentence refers ambiguously to "representative models for line 1 each cell." Please use the singular "model" to avoid the implication that there could be multiple models selected for a cell, unless that is the intent. 456. Section 6.4.5, page 6-15, Please indicate what data set(s) the statistics are calculated for, and 1" paragraph of section, clarify what is meant by "mean statistic" in this context (e.g., why is it 1 sl sentence appropriate to call the likelihood a mean statistic?). 457 Section 64.5. page 6-16. The same notation. "w". was used for the weights defining the Eqn 6.4-7 Sammon's distance metric. This is potentially confusing, especially since the term "weight" is used for both. Note also that "L" is used in this equation to represent a generic statistic, but the same symbol is defined as the likelihood in the subsequent bulleted list. Please make corrections to ensure that notation throughout the chapter is consistent and unambiguous. 458 Section 64.5. page 6-16. Please replace the typo "combing cell" with "combined cell", or perhaps paragraph 1 on page. even better by "merged cell" to be consistent with the previous sentence. to last line 459 Section 6 4.5. Page 6-16, Please define "M" and "D". Second Paragraph on page, Last Bullet 460. Section 6.4.5.1, page 6-Please explain the basis for assuming that the cited properties of 1he 17, 2°0 paragraph of section (1" paragraph on original GMPEs are also applicable to the constructed GMPEs. page). line 6 461. 6.4.5.1, page 6-17, This sentence is imprecise about the definition of the norms referred to, paragraph 2 of section as well as what space they are defined on. The sentence could be (1" paragraph on page}. interpreted to suggestthat the mean residual is an L1 norm. which it is last sentence not. nor is it even a norm at all. nor is its absolute value (neither one is positive definite). The sentence should be rewritten to make it clear what norms it refers to, and what vector space the norms apply to. Alternatively, if the sentence is not essential to subsequent arguments, please consider deleting it. 462. Section 6.4.6, General Please summarize the Tl Team's assessment of the appropriateness of the selected models and model weights in capturing the center, body, and range of the median amplitude. If such assessments are discussed in Chapters 8 and 9. please provide references to the relevant section( s ). 463 Section 6 4.6. General Please discuss the following observation: For M 7 5 and short periods (PGA and T=0.2s). the ground-motion distribution at larger distance (Rx > 30 km) is broader than at shorter distances (Rx< 10 km); see, for example, Figure 2.178 of Appendix H. Please explain the cause of this behavior. Given that empirical data are sparser at shorter distances, intuitively, shouldn't the epistemic uncertainty be larger at shorter distances than at larger distances? 464 Section 6 4.6. General Please discuss the following observation: For PGA and T=0.2s. ground-motion distributions at Rx=-1 and -5 exhibit a large negative skewness at M > 6.5: see for example. Fig. 2.236 of Appendix H. In contrast, the distribution based on the candidate GMPEs shows much less skewness. Please explain the cause of the negative skewness and justify the appropriateness of the model distribution. Also, please discuss whether the negative skewness may yield more conservative (or less conservative) hazard in comparison to the use of a less skewed distribution (such as the one from the candidate GMPEs). 465. Section 6.4.6, page 6-17, Please correct the section reference. Line 1 466 Section 6 4.6. page 6-17. Please specify the section number in the statement .. in the section for Line 5 PVNGS" 467. Section 6.4.6.1, page 6-Please clarify what the "total weights" case represents, since ii has not 17, 2°0 paragraph in been defined at this point in the text. This expression is also used section. Lines 3 and 4 without definition in Chapter 8-please make necessary edits to ensure claritv. 468 Section 6.4.6.1. page 6-Please clarify whether reference is being made to the original empirical 17, 2"" paragraph in GMPEs or to the constructed virtual GMPEs. section, Lines 4 and 5 469. Section 6.4.6.1, page 6-Please justify the weights 80%110%110%, given that the pluslminus 17, 2°0 paragraph in models are two times the standard error away from the mean. section. Lines 5 470. Section 6.4.6.1, page 6-The expression "pluslminus uncertainty model is imprecise and 17, 2°0 paragraph in ambiguous. Please use a clear, unambiguous terminology for this set of section, Lines 6 and 7 models consistently throughout the chapter. 471. Section 6.4.6.1. page 6-The residual-based weighting case for the NGA dataset is indicated as 18, 3'" paragraph of being the blue curve in Figure 6.4.6-1. That curve appears to define a section ( 1" paragraph on relatively narrow distribution (probably the second narrowest after the page), 1"' 2 sentences likelihood case for the EU dataset), apparently narrower than that of the black curve representing the GMPEs. But the text here says the opposite ("using the residual-based weights yields to[sic] ground motion distribution broader than the one associated to the candidate GMPEs". Furthermore. the prior-based case (brown curve) appears to be one of the broadest, yet the text says" ... prior-based weights lead[s) to narrow distributions." Please provide clarification as to what the conclusion actually is, and then further clarify whether the stated conclusion applies to the majority of scenarios examined in Appendix H (also note the typo. "yields to" instead of "yields a"). 472. Section 6 4.6. 1. page 6-The total weighted distribution of the simulated weighted GMPEs is very 18, 3*d paragraph of similar to the distribution for the GMPEs themselves. Please indicate if section (1" paragraph on this is true in general and if the weights were chosen to closely match page), 3'" sentence the GMPE distribution on average. 473 Section 6.4.6.2. Page 6-Please clarify if the term "quantile is the same as the term "percentile" 18, 1st Paragraph of used elsewhere in the report and appendices and, if it is. please Section, 2nd Line consider consistently using only one of these terms in order to avoid confusion. 474. Section 6.4.6.2, page 6-The phrase "Widthlrange" is vague (e.g., is there a distinction between 18, 1"' paragraph, last line width and range, and if so what is it?). Please use language that is precise about what soecific attribute(s) will be comoared. 475 Section 6 4.6.2. Page 6-Please explain the significance of the comparisons shown in Figures 18, 2nd Paragraph of 6.4.6-2 through 6.4.6-4. It appears that the two distributions are Section aenerallv similar. 476 Section 6 4.6.3. Page 6-Please explain the significance of the quantile ratio plots shown in 18, 2nd Paragraph of Figure 6.4 6-5. Section 477. Section 6.4.6.4, Page 6-Please reconcile the "broader distribution" shown in Figures 6.4.6-6 and 19, 2nd Paragraph of 6.4.6-7 with the previous figures that show similar 0.05, 0.5, and 0.95 Section, 4th Sentence quantiles for the simulated models and the GMPEs. 478 Section 6 5. 1. General There is insufficient discussion of directivity models for the dip-slip earthquake sources. Please enhance the text to address this deficiency. 479. Section 6.5.1, Page 6-19, Please replace "Somerville et al. (1999)" with Somerville et al. (1997)". 1st Paragraph of Section, 2nd Line 480 Section 6.5.1. Page 6-19, There is no mention of magnitude in Figure 6.5.1-1. although it can be 3rd Paragraph of Section. presumed that the different rupture lengths shown in this figure 2nd Line represent different magnitudes. Please include the magnitude in addition to the rupture length in Figure 6.5.1-1 for completeness and to tie the figure to the M8 magnitude mentioned in this sentence. 481. Section 6.5.1, Page 6-20, Please also reference Spudich and others (2014; Earthquake Spectra, 4'" Paragraph of section vol 3., no. 3, page 1199-1221) and Spudich and Chiou (2013; Chapter 5 (2"" on page), First of PEER's directivity working group report), since both gave an in-depth Sentence discussion on the issue of centering. 482 Section 6 5.1. Page 6-20, The NGA-West2 developers had originally concluded that the Chiou and 4'" Paragraph of section Youngs (2014) directivity model could not be used with other GMPEs (2"" on page), 2"" because of the centering issue. Please explain the basis or provide a sentence reference for assuming that the CY14 directivity model can now be used with other GMPEs. 483 Section 6 5.1. Page 6-20, Chiou and Youngs (2014) addressed the effect of directivity on only 4 Paragraph of section median amplitude. Please explain the basis for concluding that there is (2"" on page), line 6 variation of sigma along strike, and explain what sigma is referred being referred to. 484 Section 6 5.1. Page 6-20, Please explain the need for simplifying the application of the directivity 5'" Paragraph of section model. Also ensure that Watson-Lamprey (2014} (still listed as being in 3'" on page}. Line 1 preparation) will be published (or at least be in press) prior to finalizing the PSHA report if the results of the study are to be used by the Tl Team as part of their evaluation. 485 Section 6 5.1. Page 6-20, 5'" Paragraph of section Please provide a definition and a brief description of the variable "OPP." 3'" on page), Line 6 486 Section 6 5.1. Page 6-20, Please indicate if Attachment C passes peer review or the Tl Team's 61" Paragraph of section evaluation. Please describe the Tl Team's basis for accepting the 4'" on page), Line 1 simplified models in Attachment C for use in the hazard calculation. 487. Section 6.5.1, Page 6-20, Please clarify who developed the parametric model, and indicate 7'" Paragraph of section whether rupture depth (which is not mentioned here) was considered as 5'" on page). 1" 2 a parameter and found to be insignificant. sentences 488. Section 6.5.1, page 6-20, If the phrase ... at the ends of the large strike-slip faults," is meant to 81" paragraph of section indicate "at the ends of large strike-slip ruptures," please make that (61" on page), 2*d to last correction. In any case, please clarify the meaning of the phrase. line. 489 Section 6.5.1. page 6-20. To avoid potential misunderstanding. please revise the text to note that a'h paragraph of section this statement refers to the case of treating the hypocenter position as (6'h on page). line 5 random along the fault. not the case where the hypocenter is deterministically specified. 490 Section 6 5.2. Page 6-21, The first sentence is ambiguous (e.g .. "a small impact" could be First Paragraph interpreted to mean a significant one), and the Workshop 3 reference is incorrect (Section 4 does not exist). In any case. please cite the Chapter 14 sensitivity studies here to provide an adequate technical justification for the simplified treatment of directivity. Once the Chapter 14 sensitivities are referenced, consider whether also citing the workshop proceedings is redundant. 491 Section 6 5.2. Page 6-21, Please provide a discussion of other directivity models published since First Paragraph. Last 2008, including why Chiou and Youngs was selected but not alternative Sentence models. 492 Section 6 6.1. Page 6-21, In order to avoid confusion. please reserve the term "proponent models General and "proponent methods" to refer to models or methods proposed by Proponent Experts as defined in the SSHAC guidelines. Please use a different name to refer to models proposed by the Tl Team here and elsewhere throughout the report and appendices. 493. Section 6.6.1, Page 6-21, Please define what is meant by "path terms" the first time it is used, so 2nd Paragraph of the reader need not have to read Appendix L to understand what the Section, 1st Line term means. 494. Section 6.6.1, Page 6-21, Please provide a reference to the specific report sections, tables and/or 3rd Paragraph, Line 3 figures where the description is provided. 495 Section 6 6.2. Page 6-21, Please clarify what the units (and sign) of the path term mean, and First Paragraph, Line 1 explain whether the large negative path term (about-0.5) for regions 2 and 3 appears reasonable on geological and geophysical grounds, such as known differences in crustal structure. Also, please comment on the size of the path term compared to those estimated for other regions by previous studies. 496. Section 6.6.2, Page 6-21, Please comment as to whether additional epistemic uncertainty in the First Paragraph, Line 1 path term is warranted, given that a sparse dataset was used in its estimation. 497 Section 6 7.1. Page 6-22, Please define what is meant by "R" here. First Paragraph. Line 5 498 Section 6 7.1. Page 6-22, The term "PSA" is used on line 7. and "Sa" is used in Eq. (6.7-1). Please First Paragraph, Line 7 select and use a consistent term for this parameter. and Eqn 6.7-1 499. Section 6.7.1, Page 6-22, Please provide a short description of the motivation behind Method 1. First Paragraph. Line 10 500 Section 6 7.1. Page 6-22, Please consider revising the phrase "single representative rupture" so First Paragraph. Last that it will not be misconstrued as a new rupture geometry modified from Sentence the rupture geometry specified in the SSC model. For example, doesn't the method create a single representative set of predictor variables? 501 Section 6 7.1. Page 6-22, Please define the term "WidthDD" here and include it in the list of terms. Second Paragraph, First Sentence 502 Section 6 7.1. Page 6-22, Please check whether the second sentence is redundant-given that it Second Paragraph appears to just repeat the content of the first sentence-and revise if appropriate. 503. Section 6.7.1, Page 6-23, Please define the distance metric R", and consider changing the phrase Paragraph of section "based on distance" to something like "based on inverse-squared paragraph on page), distance". Line 3 504 Section 6.7.2. General There are empirical ground-motion data from historical earthquakes that exhibited complex rupture or splay fault rupture. including those in the NGA-West2 database and the 2011 Fukushima-Hamadori, Japan, earthquake. Please indicate whether these empirical data were used by the Tl Team to evaluate the four proponent methods. If so, please describe the main results of the evaluations: if not, please explain why not. 505 Section 6 7.2.1. Page 6-Please explain what is meant by the term "main rupture" or rewrite the 23, 1st Paragraph of section in a form that does not depend upon making that distinction. Section, Last Line 506. Section 6. 7 .2. 1 , page 6-Please rewrite this sentence to improve its syntax and clarity. 23, paragraph 3 of section. 1*1 sentence 507. Section 6. 7.2.1, Page 6-Please briefly summarize the discussion from Appendix J explaining the 23, Second Paragraph, extent to which these complex scenarios cover the full range present in Line 2 the SSC model. Also please provide specific (subsection number) reference(s) to that discussion to justify the sufficiency of these scenarios. Also, Figure 6.7.2-1 does not provide a clear annotation of the associated geometry for the main rupture, the combined rupture, and the location of the site mentioned on Line 2. Please revise the text and the figure to correct these deficiencies. 508 Section 6 7.2.1. page 6-Please explain more clearly and precisely what the term 23, 3'" paragraph of "complex/simple LN (ratios)" means Also. please use conventional section. lines 3-5 notation such as ln(x) for the natural log of x (here and elsewhere in the report). 509 Section 6.7.2.2. Page 6-Please briefly summarize the discussion from Appendix J explaining that 24, Second Paragraph these splay scenarios cover the full range present in the SSC model. Also please provide specific (subsection number) reference(s) to that discussion to justify the sufficiency of these scenarios. 510 Section 6 7.2.2. page 6-Please rewrite this sentence to clarify its meaning. 24, paragraph 3 of section. 1*1 sentence 511 Section 6 7.2.2. page 6-The text stales lhat "The site is assumed to be localed near the splay 24, 2"* paragraph of rupture (otherwise lhe effect of the splay can be ignored}." If in the upper section. last line right diagram of Figure 6.7.2-1 the site were moved from "near the splay to near the part of the main fault southeast of the junction, what would be different? Please explain the origin of the asymmetry; that is, please explain why the splay can be ignored if the site is near the main fault (the part of the main fault that is SE of the junction. just like the splay is). but the SE part of the main fault cannot be ignored if the site is nearthe splay. Alternatively. consider deleting the parenthetical comment if it is irrelevant to the ground motion model. 512. Section 6.8, Page 6-25, Please provide a more complete description of the Abrahamson (2000) 4th Reference reference (e.g., dates and location of the conference, paper number, proceedings pages, etc.) 513 Section 6 8. Page 6-25, Please update the Abrahamson et al. (2014) reference with page 6th Reference numbers from the published manuscript. 514 Section 6 8. Page 6-25, Please replace the date "2013 with "2014a" in the Akkar et al (2013) 7th Reference reference to reflect the actual date of publication. Note that the "a" should be added because the referenced erratum was published in the same year. 515. Section 6.8, Page 6-25, Please update the Akkar et al. (2014) reference with the volume and 8th Reference page numbers of the published manuscript. Please also replace the date "2014" with "2014b" to reflect the fact that the original manuscript was published in the same year as the erratum. 516. Section 6.8, Page 6-25, Please update the Al Atik and Youngs (2014) reference to include the 9th Reference page numbers of the published manuscript. 517. Section 6.8, Page 6-25, Please replace the date "2013" with "2014a" in the Bindi et al. (2013) 11th Reference reference to reflect the date the manuscript was published and the fact that the erratum was published in the same year. 518. Section 6.8, Page 6-25, Please replace the date "2014" with "2014a" in the Bindi et al. (2014) 12th Reference reference to reflect the fact that the original manuscript was published in the same year. 519. Section 6.8, Page 6-25, Please update the reference Bommer et al. (2014) to include volume 13th Reference and page numbers of the published manuscript. if available. 520 Section 6 8. Page 6-25, Please update the Boore et al. (2014) reference to include the page 15th Reference numbers of the published manuscript. 521 Section 6 8. Page 6-26, Please update the Campbell and Bozorgnia (2014) reference to include 1st Reference the page numbers of the published manuscript. 522 Section 6 8. Page 6-26, Please provide the organization that the Chiou et al. (2000) report was 2nd Reference submitted to. 523. Section 6.8, Page 6-26, Please update the Chiou and Youngs (2014) reference to include the 4th Reference page numbers of the published manuscript. 524. Section 6.8, Page 6-26, The Graizer (2014) reference is not cited in the text. Please either cite 7th Reference this reference or remove it from the list of references. 525 Section 6 8. Page 6-26, The Graves and Pitarka (2014) reference is not cited in the text. but is 8th Reference probably the reference to the acronym "G&P" (also cited as "GP") used to identify one of the simulation methods in some of the figure captions. Please cite this reference the first time that the acronym G&P" is used and use a consistent acronym for this reference. 526. Section 6.8, Page 6-26, Please update the Idriss (2014) reference to include the page numbers 9th Reference of the published manuscript. 527 Section 6 8. Page 6-26, Please replace the date "2014a" with "2014" in the Kashida et al. (2014) 12th Reference reference. 528 Section 6 8. Page 6-26, The Olsen and Takedatsu (2014) reference is not cited in the text. but is 14th Reference probably the reference to the acronym "SDSU" used to identify one of the simulation methods in some of the figure captions. Please cite this reference the first time the acronym "SDSU" is used. 529 Section 6 8. Page 6-26, Please provide a more complete description of the Somerville and 17th Reference Abrahamson (1995) reference (i.e., report number, organization, etc.). 530. Section 6.8, Page 6-27, Please update the Watson-Lamprey (2014) reference with the report 2nd Reference number, publisher, etc., if available. If the report is not published or in press at the time the SWUS report is finalized. any reference to the PEER report should be removed from the report and characterized as an analysis performed for the Tl Team and included as an appendix. 531. Table 6.6-1, Page 6-29 The values given in Table 6.6-1 do not appear to be consistent with the proposed models shown in Figure 6.6.1-2. Please explain why this is the case, or if in error, correct the table or figure. 532 Table 6.7-1. Page 6-30 Please define the term "DDWidth" the first time it is used 533 Figure 6.2.1-1. page 6-31 In the explanation. the acronym "ld14" is used. whereas in the text. it is given as "114. Please choose one and be consistent. This same comment applies to the corresoondina fiaures. 534. Figure 6.2.1-2, Page 6-32 Please explain what the term ZH06 = ZL 11 means in the legend and correct "ZH06" to "Z06" and "ASB13" to "ASB14" to be consistent with the terminology used in the text. 535 Figure 6.2.3-1. page 6-34 The caption refers to periods at 0.2. 0 5, 1.0 and 2.0 seconds. but is not clear as to which panel is which. Please label the individual panels for clarity. Please also remove mention of a specific period in the legend, since period varies from panel to panel. Also correct the legend to refer to the NGA-West2 models by the acronyms used in the text (e.g., "ASK14). 536. Figure 6.2.3-2, Page 6-Please explain the meaning of the phrase "over frequency" in the figure 35, and Figure 6.2.3-3, caption. Page 6-36 537 Figure 6.3.1-2. page 6-38 The solid (5 km) and dashed (10 km) curves should be better explained in the caption. Also. please refer to the GMPEs in the legend by the acronyms used in the 1ext (i.e .. "ASK 14" instead of "ASK") 538 Figure 6.3.3-1. page 6-39 Please add an explanation of the black curves to the caption. Please also define the terms EXSIM, G&P, and SDSU and provide citations to references in the list of references. The apparent references to these models in the list of references are incomplete and should be updated to .. in press" or published when possible. Please note that the reference to EXSIM is missing from the list of references. 539 Figure 6.4.3-1. page 6-40 Please provide in the caption the predictor variable values for which the plot was generated. Also please consider explaining more explicitly that the red curves represent the distribution of the median (mean of natural log) for each GMPE based on the Al-Atik and Youngs (2014) analysis of epistemic uncertainty. 540. Figure 6.4.3-2, page 6-40 Please explain in the caption how to distinguish the Model A and Model B samples. and also give the meaning of the solid dots and their colors. Please also define the axis labels. The plot of sampled models" is for 15.000 samples. but 2,000 samples were used. Please replace this plot with one for 2,000 samples to better represent what was used in the evaluation. 541. Figure 6.4.4-1, page 6-41 Please correct the caption to read "mean between-event residuals," add an explanation of the black dots. and identify the "contours" as the gray lines in the plot. 542. Figures 6.4.6-2, 3 and 4, Please add explanatory text to the caption indicating that the solid lines pages 6-43, 6-44, and 6-are the 0.5 quantiles, whereas the dashed lines represent the 0.05 and 45 0.95 quantiles 543. Figures 6.4.6-2, 3, 4 and Please explain the meaning of the term "total weights" in the figure 5, pages 6-43, 6-44, and caption. 6-45 544. Figure 6.5.1-5, Page 6-47 Please replace the date "1999" with "1997" in the Somerville et al. (1999) reference in the figure caption. 545. Figure 6.6.1-1, page 6-49 Please correct the mislabeling of the figure in its caption. Also, in the caption, please specify which colors are referred to for the "colored lines" that represent faults, as there are also colored lines that separate regions. Also please add the location of PVNGS to the map. Note also that 5 earthquakes appear to be located in Region 1. whereas the text seems to indicate that there are 3 (first line on Page 6-22). Please review and revise this caption as needed. 546 Figure 6.6.1-2. page 6-50 Please correct the mislabeling of the figure in its caption. and provide the units for the oath terms aiven in the clots 547 Figure 6.7.2-2. page 6-52 Please label the vertical axis. The simulation model acronyms in the figure caption have not been defined in the text at this point. Please make sure they are defined and cited prior to being used the first time and that they are included in the list of references. Note also that the acronym "GP" is referred to as "G&P" elsewhere in the chapter. Please use a consistent acronym for "G&P" throughout the report and appendices. 548 Figure 6.7.2-2.3.4, pages Captions for these figures are inadequate. Please write captions that 6-52. 6-53. and 6-54 indicate the scenarios for which results are depicted and, in the case of Figure 6.7 2-3. indicate what the respective colors represent. Also label and provide units for they axis in Figure 6.7.2-4, and check that all references to the simulation models use acronyms that have previously been defined and are consistent with usage in the rest oflhe report. CHAPTER 8 Median GMC Models: DCPP Sources 549. Section 8.1, page 8-1, Please consider writing a more precise statement of the procedure. numbered item 4 For example, would it be better described as sampling from the multivariate normal distribution defined by the coefficient covariance matrix? 550. Section 8.1, page 8-1, This statement is impossible to parse. Please consider rewriting to item 5 improve its clarity. One option to consider is breaking it into 3 items, the first stating the formation of high-dimensional vectors. each representing the ground motion predictions of a given model for a representative range of predictor variables, the second stating that a metric is defined on that high-dimensional space based on the differences in hazard level between model pairs. and the third stating that the vectors are represented in two dimensions via a (nearly) metric-preserving mapping procedure by means of a Sammon's map. If the term "deaggregation" is retained in the revision of this passage. please indicate what it means in this context (ie .. what was deaggregated and for what set of parameters). 551. Section 8 .1 , page 8-1 , Please specify that it is the two-dimensional space (i.e .* after the item 6 Sammon's mapping procedure is applied) that is discretized. 552. Section 8.2, page 8-1, The statement that weights associated with statistical sampling are 1"' paragraph of shown in green seems a little odd, since none of the weights in the section. 2"" sentence figure are actually shown in green (and in fact there are no green weights in any of the figures in the entire chapter). Please consider revising this and other related statements to avoid confusion. 553. Section 8.2, page 8-1, Weights of the base models are not provided on Figure 8.2-1. 1"' paragraph of Please provide the missing weights and indicate the nature of these section. 2"" sentence weights (i.e. are they subjective weights or weights associated with statistical sampling). 554. Section 8.2, Page 8-The definition of "base model" is given after it is first mentioned on 1. Second Paragraph Line 1 of Page 8-1 . Please move this definition to where it was first of section, Line 2 mentioned. 555. Section 8.2, Page 8-2. 4th line on page Please explain how a HW model was assigned to each base model. 556. Section 8.2, Page 8-Please clarify if the hazard for spectral periods longer than 3 sec are 2. 3rd Paragraph of part of the deliverable and. if yes. please provide a reference to the section (2"c on page). sections where median models for these long period spectra are Line 2 evaluated and integrated into logic trees. 557. Section 8.2, Page 8-Please summarize the meaning of the different branches in the logic 2, 3"' Paragraph of tree in Figure 8.2-2, similarly to what was done for Figure 8.2-1. section (2"" on page), 2nd Sentence 558. Section 8.2, Page 8-The discussion in Section 8.3 suggests that the Tl Team's focus is 2. 3rd Paragraph of on capturing the CBR of median-amplitude predictions. Please section (2"c on page). provide text to clarify that "median ground motion models" is a Last Sentence shorthand for "median amplitude predicted by alternative GMPEs:* 559. Section 8.3, Page 8-Please clarify whether the comment on the Rjb-based formulation is 2, First Paragraph of directed toward the GMPEs (such as BSSA14) or toward the choice section, Line 4 of the distance metric used in the common-form models. 560. Section 8.3, Page 8-Please specify the (lower) bound of the HW effect and how "being 2. First Paragraph of log-normally distributed" is unable to satisfy such a bound section. Line 6 561. Section 8.3, Page 8-Please refer to the specific branch in the Figure 8.2-1 logic tree 2. 1st Paragraph of Section, Sentence when describing weights. 562. Section 8.41, Page Please revise the text to be specific about the quantity to which the 8-2, 1" Paragraph of term range" refers. For example, is it the median amplitude section, First Line predicted by the GMPEs or the GMPEs themselves? 563. Section 8.4.1, Page The terms "common-form models" and "candidate GMPEs" are 8-2, 1st Paragraph of referred to by different names throughout the report and appendices. Section, 1st Sentence Please define a common set of terms for these models and use them consistently throughout the report and appendices and include them in the list of terms. 564. Section 8.4.1, Page The statistical uncertainty analyzed and parametrized by Al-Atik and 8-2, 1" Paragraph of Youngs (2014) was for the NGA-West2 GMPEs and associated section, Lines 4 and 5 datasets. Please comment on whether their results were also applied to non-NGA-West2 GMPEs and, if so. please justify that decision. given that a non-NGA GMPE may use a dataset different from those used by NGA-West2 GMPEs. 565. Section 8.4.1, Page Please revise the text to make it clear that the "+-2 sigma range" is 8-3, 2"" Paragraph of relative to the original candidate GMPEs. section ( 1*1 on page). Line 2 566. Section 8.41, Page Please reference the relevant sections of the report andlor 8-3. 2"d Paragraph of appendices where the process of reducing the range in the common-section ( 1*1 on page). form models is reduced based on comparison with ground-motion 2°0 sentence data. 567. Section 8.4.1, page 8-Please consider rewording this paragraph to indicate that the check 3, paragraph of is done to determine whether the resulting reduced range (not the section (1"' on page), method) is appropriately wide. last sentence 568. Section 8.4.1, Page Please explain the phrase "weighted standard deviation between 8-3, 4** Paragraph of ground motions predicted by two different models .. :*, and explain section (3'" on page), (or provide a reference for) how it can be approximated by the Third Line distance between two points on a Sammon's map. 569. Section 8.4.1, Page Please indicate what the term "deaggregation" means in this context 8-3, 4** Paragraph of (i.e., what was deaggregated and for what set of parameters). section (3'" on page), 5"' line 570. Section 8.4.1, Page It appears that only seven red dots are plotted on Figures 8.4-1 and 8-3, 5** Paragraph of Figure 8.4-2. Please check and correct the text or figures as needed. section (4:" on page). Line 2 571. Section 8.4.1, Page Please consider adding, parenthetically, a brief descrip1ion of 1he 8-3. 61" Paragraph of NGAW2nc database section (5'" on page). 4'" line 572. Section 8.4.1, Page In setting the regions from which GMPEs are selected based on the 8-3. 6111 Paragraph of mean residual, please comment if the use of a horizontal ellipse is section (5'" on page), compatible to the roughly 45-degree inclined pattern of the mean Last Sentence residuals. 573. Section 8.4.1, Page For the upper left plot, please label the contours of 1, 0.3, 0, -0.3, 8-3. 6111 Paragraph of and -1. section (5'" on page). Last Sentence, Figures 8.4-1 and 8.4-? 574. Section 8.41, Page Please comment on the causes of the numerous small patches 8-3. 6111 Paragraph of inside the horizontal ellipse. section (5'" on page). Last Sentence, Figures 8.4-1 and 8.4-2 575. Section 8.4.1, Page Please explain what "likelihood" is shown in the figures (i.e., the 8-4. 91" Paragraph of likelihood with respect to what). section (2"" on page). 1"' line 576. Section 8.41, Page Please explain why a fixed sigma value of 0.65 was used and what 8-4. 91" Paragraph of impact it has on the results. Please also indicate whether .. sigma" in section (2"c on page). this case is the between-event. within-event, or total standard 2°0 line deviation. 577. Section 8.4.1, Page Please explain the significance of a relatively low versus a relative 8-4. 91" Paragraph of high likelihood. section (2"" on page). 4"' line 578. Section 8.4.1, Page Please add additional contour levels to Figures 8.4-1 and 8.4-2 to 8-4, 9'" Paragraph of help show the likelihood value of each GMPE. section (2"" on page). Line 5 579. Section 8.41, Page In this section, the utility of using both the mean residual and the 8-4, 11 '" (last) likelihood in setting the ranges was discussed. Please give a clear Paragraph of section and explicit summary of the roles played by each one in setting the final range. The boundaries shown in Figures 8 4-1 and 8.4-2 seem to suggest an unimportant role of the likelihood. 580. Section 8.4.1, Page 8-4, 11 '" (last) There seems to be a large overlap in information and discussions between this paragraph and the sixth paragraph on Page 8-3 (7'" Paragraph of section paragraph of Section 8.4.1 ). Please consolidate these two paragraphs where appropriate. 581. Section 8.41, page 8-Please replace epistemic" with "epistemic uncertainties." Please 4, 11" (last) also indicate the number of standard deviations used to represent paragraph of section, those uncertainties in the cited figure. line 3 582. Section 8.41, page 8-Please explain why an extrapolation of the candidate GMPEs is 4, 11" (last) found in some cases and not in others. paragraph of section, last sentence 583. Section 8.4.2, Page Please be more specific about the parameter that is being referred 8-4. First Paragraph to. of section. Line 2 584. Section 8.4.2, Page Please give a reference to where a summary of the datasets used in 8-4. 2"1 Paragraph of this section is provided. section, Line 2 585. Section 8.4.2, Page Please provide a figure similar to Figure 8.4-4 for the simulated 8-5, 2"" paragraph of ground-motion data. section (1"1 on page), 1"' line on page 586. Section 8.4.2, Page Please provide references to the sections where such definitions are 8-5. 3'd Paragraph of given. section (2"" on page). Lines 1 and 2 587. Section 8.4.2, Page Please provide the technical basis for the Tl Team's selection of the 8-5, 3'0 Paragraph of (60, 40) mixing between the residual-based and likelihood-based section (2"" on page), weights. Line 4 588. Section 8.4.2, Page Please explain how the "judgments by the GMPE developers" are 8-5, s'* Paragraph of transmitted and maintained by the selected GMPEs. section (4:" on page), Item 3. Line 1 589. Section 8.4.2, Page The concern of non-independent model development has been 8-5, 5** Paragraph of brought up numerous times in this report. In this section, it is used as section (5:" on page), a critical factor in the Tl Team's evaluation of weights assigned to 1"' sentence GMPEs It is thus both helpful and important to have a clear discussion of this concern, including its causes, the magnitude-distance ranges where it is a prevalent issue, and an assessment of the extent of the resulting .. redundancy." Please provide such a discussion. either here or in Chapter 6. 590. Section 8.4.2, Page Please indicate what actual weights the decision of a 3 to 1" 8-5. last paragraph on preference leads to for the empirical and the simulated data sets. page, last sentence 591. Section 8.4.2, page 8-Please replace "cumulative density function .. with "cumulative 6, t* (last) paragraph distribution function." in section. line 2 592. Section 8.4.2, Page Please clarify the meaning of .. range" as used in this sentence. The 8-6. i* (last) likelihood approach seems to render a narrower "shape" (body) than Paragraph in section. other approaches but its range (the difference between the largest Line 5 and the smallest value) is comparable to others. Please be precise when the concept of the center and body of a distribution is invoked. 593. Section 8.4.2, Page Please provide the criteria against which reasonableness is 8-6. i* (last) assessed. Paragraph in section. Line 7 594. Section 8.4.2, Page Please clarify whether this is generally the case for different 8-6, t* (last) scenarios and spectral periods. paragraph in section. 2** to last Sentence 595. Section 8.4.3, page 8-Please clarify that the CDF associated with the selected weights 6. 1"' paragraph of (not the weights themselves) has the property indicated Also section. line 4 indicate that "median" refers to CDF=0.5 on Figures 8.4-5 and 8.4-6. 596. Section 8.4.3, page 8-Please check the values given here for the offset of the medians in 6, 1" paragraph of Figure 8.4-5. For example, are the red (selected weights) and brown section, lines 4 & 5 (GMPEs) 50'" percentile values offset by about 0.1 natural log units (rather than 0.05 as stated). and is the purple (simulations) curve offset from the red by at least 0.15 log units (not 0.1 as stated)? 597. Section 8.4.3, Page Please clarify what is meant by the phrase slope of the CDF" and 8-6, 1" Paragraph of how this slope defines the body of the distribution. section, Last Sentence 598. Section 8.4.3, Page Please explain why curves representing the statistical uncertainties 8-6. 3'd Paragraph of of each original GMPE are not included in these plots (whereas they section. Line 2 are included in previous figures for evaluation of the CBR of the ground motion distribution), and explain the odd shape of the 0.05 quantile curve for M7.5 in Figure 8.4-7. 599. Section 8.4.3, Page Please explain why the 50% value does not always track the median 8-6. 3'd Paragraph of of the predictions of the original GMPE (e.g., see the upper right plot section. Line 2 in Figure 8.4-9). 600. Section 8.4.3, page 8-In Figure 8.4-7, it appears that the selected models do not quite 6, 3"' of envelope the original GMPEs for M 7.5 (e.g., at distance Rx<2), as section, 3' sentence categorically claimed in the text. In fact. the figure gives the impression that M 7 5 is at least as much as exception (to the models enveloping the GMPEs) as is M 5.5, and the text does note the latter exception. Irrespective of whether the exceptions are significant. the apparent inconsistency between the text and the figure is confusing. Please clarify. 601. Section 8.4.3, page 8-Although the reason for the selected M5.5 models not enveloping 6. 3rd paragraph of the original GMPEs is given. please also explain why it is acceptable section. 4'" sentence to allow this underestimate of the range in GMPEs in the model. 602. Section 8.4.3, page 8-6, 3"' paragraph of section, 2"" to last line Please state the rationale for the Tl Team judgment cited here. on page 603. Section 8.4.3, Page Curves from the models with additional epistemic uncertainty are not 8-7. 3'd Paragraph of shown in Figure 8.4-10. Please correct this oversight. section (1"' on page), Line 1 604. Section 8.4.3, page 8-The phrase "all of the models are not enveloped" reads as if none of 7, 3'd paragraph of the models are enveloped. Please rephrase to state" ... not all of the section (1"' on page), models are enveloped due to the sharp ... last 2 lines 605. Section 8.4.3, page 8-Please indicate what "lower" and "higher" center for the simulations 7, 6'" paragraph of is with respect to (e.g., the GMPEs, the Tl Team's weighted average section (4:" on page), model, etc), and whether it refers to ground-motion amplitude or 3'" sentence probability. 606. Section 8.4.3, page 8-Please explain the meaning of "the upper tail of the distribution" in 7, 6'" paragraph of this con1ext, and consider whether i1 is appropriate terminology to section (4'" on page). refer to 1he "center and body" of the upper tail distribution, or whether last sentence this may be an oxymoron. In any case, please define clearly what is meant in this context. 607. Section 8.4.3, Page Please improve the text so it is clear and easier to understand. The 8-7, 7'" Paragraph of revision should also indicate that CDF=0.5 refers to the median of section (5'" on page), the distribution and state what specific "statistics" are computed. Lines 1 to 5: 608. Section 8.4 3. Page 8-7. i" Paragraph of section (5"' on page). Please explain what the "zero residual" is with respect to. Line 8 609. Section 8.4.3, page 8-8, 8'" paragraph of Please no1e that the phrase "distance scaling" is repeated. section ( 1"' on page). line 2 610. Section 8.4.3, Page Please clarify which curve in Figure 8 4-17 corresponds 1o the mean 8-8, 11 '" paragraph of hazard. Also. please revise the categorical statemen1 "larger than the section (4'" on page). hazard from GMPEs" (which appears to be true at low probability but Second Sentence not necessarily at high probability). 611. Section 8.4.3, Page The original GMPEs with statistical uncertainties are an essential 8-8. 11 "' paragraph of part of the overall epistemic uncertainty in the median motion, and section (4'" on page), they are used extensively by the Tl Team in Section 8.4 to set 1he Third Sentence ranges from which representative GMPEs are selected. Given this, please justify why the hazard based on these GMPEs is not included in the checking exercise. 612. Section 8.4.3, Page The average hazard from the GMPEs is not shown in Figure 8.4-17. 8-8, 11 '" paragraph of Please revise this statement to refer to "hazard" instead of mean section (4'" on page), 5"' line hazard. 613. Section 8.4.3, page 8-Here the acronym "1014" is used, whereas in Chapter 6, it was "114". 8, 11'" paragraph of In many of the figures, it is denoted ld14." Please choose one section (4'" on page), acronym and be consis1ent throughout the text and figures. Also note line 7 that 1here is no separate GMPE for ZL 11 (it represents a method for characterizing magnitude saturation). Please describe how ZL11 was used to create a GMPE where the empirical GMPEs are first discussed and assign it a unique acronym to use here and elsewhere throughout the report and appendices. 614. Section 8.5, page 8-9, This section seems to imply that HW effects are no1 involved in the general model generation and representative model selection of Chapter 6. 11 is not clear how this is consistent with the second to last paragraph of Section 6.4.4, where HW effects appear to have been assigned by some form of sampling during the selection of representative models. Please clarify. 615. Section 8.5, Page 8-Please explain what the term "HW3" means. 9, First Paragraph, Second Line 616. Section 8.5, Page 8-Please review the suitability of using the word "range" in the context 9. First Paragraph. of this sentence. Please also indica1e whe1her 1he cen1er and body is Las1 Sentence also captured. 617. Section 8.6, Page 8-The workshop summary (near the bottom of Page G-17) suggests 9, First Paragraph, that directivity has a significant effect on hazard, opposite to what is First sentence stated in this sentence. Furthermore, there is insufficient technical material in the workshop summary 1o allow for a review by the PPRP. Instead of citing the workshop summary, please provide a complete documentation of the hazard sensitivity analysis that supports the conclusion given in this sentence. or provide a reference to the section of the report 1hat does so. 618. Section 8.6, Page 8-Please explain how directivity effects were taken in1o account or 9, 1st Paragraph of provide a specific (chapter. subsection) reference for that Section, Last explanation. Sen1ence 619. Section 8.7, Page 8-There is insufficient technical material in the workshop summary to 10, Firs! Paragraph. allow for a review by the PPRP. Please provide a complete Last Sentence documenta1ion of the hazard sensitivity analysis that supports the conclusion given in this sentence or provide a reference to the section of the report that does so. 620. Section 8.8, page 8-Please see previous comments regarding the list of references for 10 other chapters and appendices for guidance on revising the list of references in this chapter. 621. Table 8.4-1, page 8-Please indica1e in the caption what is meant by the term "SOF." 11 622. Figure 8.2-2, Page 8-Please indicate in 1he caption the meaning of the various branches 13, caption (e.g., what is meant by 1he terms "SIM". "NGAW2DC-MED" etc.). 623. Figure 8.4. 1. Page 8-Please define the units for the color bar and explain the "In" in the 14 and Figure 8.4.2, axis labels. Also please explain why these two plots label the axes Page 15 "In uni1s" whereas what seem 1o be corresponding plo1s in Chapter 9 (Figures 9.1-2a,b and 9.1-3a,b) have their axes labeled "C 1" and C2". If there is no reason for a distinction, please make changes so th;it 1hPv ::irP ronn***'nl. 624. Figure 8.4-3. page 8-Please indicate in the caption and/or legend the number of standard 16 deviations that have been used 1o represent the uncertainties 625. Figures 8 4-5. 8.4-6, In the captions of these figures, "cumulative density function" is page 8-18; and & 8.4-incorrect terminology. Please replace by "cumulative distribution 11, page 8-23 function" 626. Figure 8.4-7, page 8-Please explain the meaning of the term "to1al weights" in the figure 19 caption of this and other similar figure captions. 627. Figure 8.4-12, 8.4-13, Please make the titles on the figure subplots legible. page 8-24; and 8.4-14, page 8-25 CHAPTER 9 Median GMC Models: PVNGS Sources 628. Sections 9.1 Through These sections are very similar to those discussing the DCPP 9.1.3 median GMC models. Please review those Chap1er 8 comments and apply 1he relevant ones to the PVGNS discussion in these sections. Note that some, but not all, of 1hese comments are repeated below. 629. Section 9. 1 , page 9-1 , Please consider writing a more precise s1a1ement of the procedure. numbered item 4 For example, would it be better described as sampling from the multivariate normal distribution defined by the coefficient covariance matrix? 630. Section 9. 1 , page 9-1 , This statement is impossible to parse. Please consider rewriting to item 5 improve its clarity. One option to consider is breaking it into 3 items, the first stating the formation of high-dimensional vectors, each representing the ground motion predictions of a given model for a representative range of predic1or variables. 1he second stating that a metric is defined on that high-dimensional space based on the difference in hazard level between model pairs, and the third stating that the vectors are represented in two dimensions via a (nearly) metric-oreservina maooina orocedure. 631. Section 9. 1 , page 9-1 , Please specify that it is the two-dimensional space (i.e .. after the item 6 Sammon's mapping procedure is applied) that is discretized. 632. Section 9.1.1, page 9-To avoid confusion. having introduced the convention about red and 2. last paragraph of green weights in connection with Figure 9 .1-1 , please consider section noting that Figure 9.1-1 itself does not actually show any statistical-sampling (green) weights. Also, since only one additional figure in the chapter, Figure 9.2-1. actually uses the redfgreen convention. it would be clearer to simply name that figure. rather than saying "In Figure 9.1-1 and subsequent." 633. Section 9.1.2, Page Please describe and show the misfits to the predictions from the 9-2. First Paragraph. original GMPEs by the RR11ro*based and R.iR*based common forms. Line 8 Please discuss whether the weights (0.7, 0.3) assigned 1o the RRuro* based and RJa-based branches, respec1ively, are consistent with 1he misfits. 634. Section 9.1.3.1. Page Please review whether using a term like "distribution" or "center. 9-2. First Paragraph. body. and range" would be more appropriate here than using just the Line 1 term .. range". There are other instances throughout Chapter 9 where the term "range is used. Please also review those instances and revise where appropriate. 635. Section 9.1 3 2. Page Please explain why the Tl Team limits the dataset to events with at 9-5. 2"" paragraph of least 3 recordings per earthquake and whether such a limit is also section ( 1 *1 used in the DCPP evaluation. Paragraph on page), 1"' line on paqe 636. Section 9.1 3 2. Page In Figure 9.1-7, the M 6.6 event appears to have just one recording. 9-5. 2"" paragraph of Please check whether this is an error and revise if needed. section ( 1*1 paragraph on page), 1" sentence on oaae 637. Section 9.1 3 2. Page In the preliminary draft of Chapter 5 (noting that we have not yet 9-5. 2"0 paragraph of seen Rev O for that chapter). in Figure 5.1.3-2. there are a large section ( 1*1 paragraph number of recordings that appear to come from a single M 6.9 on page), 1" sentence normal-faulting event. These data are not included in Figure 9.1-7. on page Please explain why they a re not included in Figure 9. 1-7 and are not used for PVNGS. 638. Section 9.1 3 2. Page Please verify that the 2009 M 6.3 L'Aquila earthquake is included in 9-5. 2"0 paragraph of the EURrv-r.<Fn data set If not. please explain why not. Also. please section ( t*1 paragraph discuss whether all European events in the PEER NGA-West2 on page), last database satisfying the minimum of 3 recordings-per-event sentence requirement are captured in EURpv .... eo-If not, please explain (preferable in Chapter 5) why they were excluded. Conversely. please discuss if all EURrv-MFn events are included in PEER's NGA-West2 database. If not, please explain whey they were excluded. 639. Section 9.1 3.2. page Since weighting is used in several different senses in the chapter. 9-5. 41" paragraph of please consider adding a phrase to clarify that there is no section (3'" on page), reweighting of different style-of-faulting cases in the calculation of the last line mean-residual and likelihood, if that is the meaning that is intended here. 640. Section 9.1 32. Page Please explain what differences in mean residuals mean. The 9-5, 5'" Paragraph of definition given in Section 6.4.5 does not mention the word section (4:" on page), "difference .. Line 3 641. Section 9.1.3.2, Page Please clarify whether the phrase "range of underlying GMPEs" 9-5, 5'" paragraph of means the range of predictions of the median amplitude by the section (4:" on page), underlying GMPEs. Also, please clarify whether the epistemic-Last Sentence uncertainty versions are also used in the evaluation of mixing weights. 642. Section 9.1.3.2, Page Please discuss the Tl Team's assessment of the quality of the 9-6, 7'" paragraph of EURrv-Mm dataset. such as issues related to record screening (for section ( t*1 Paragraph example, removal of low signal-to-noise ratio records and non-free on page). Line 4 field records), record processing, and accuracy of magnitude estimates Also please clarify whether both data quality and data coverage in the key magnitude range are considered in the Tl Team's assessment of relative weights. If the answer is yes, please document Tl Team's evaluations and conclusions. If the answer is no. please provide further justification of the ratio of 3:1. accounting for these two additional considerations. 643. Section 9.1.3.3, page Please correct this term to the correct term .. cumulative distribution 9-6, 1" paragraph of function." section. line 2 644. Section 9.1.3.3, page For the NGA dataset. the residual approach (blue curve) seems to 9-6, 1" paragraph of give a narrower distribution than does the likelihood (orange curve). section. 2"d to last If this is true, it contrasts with the categorical statement to the sentence contrary in the text, which is confusing (even though it doesn't vitiate your main point about the advantages of the weighted model). Please clarify. 645. Section 9.1 3 3. page As in Chapter 8, please correct the phrase "distance scaling and 9-7. i" paragraph of distance scaling". section (4"' on page). line 2 646. Section 9.1.3.3, page 9-8, 9'" paragraph of Please substitute .. and" for the slash between California and Mexico section (2"" on page), line 4 647. Section 9.1.3.3, Page Please explain why the uncertainty in hazard shown in Figure 9. t-9-8. 91" paragraph of t 9a (for Model A) is much larger than the hazard uncertainty shown section (2"" on page). in Figure 9.1-19b (for Model B). _ Lines 5 to 7 648. Section 9.1 3 3. Page Please clarify whether the mean hazard is weighted by the branch 9-8. 1 o'" paragraph of weights. section (3'd Paragraph on page), Line 1 649. Section 9.1 3 3. Page Please include in Figures 9.1-19 and 9.1-20 a curve representing the 9-8. 1 o'" paragraph of average hazard from the original GMPEs. section (3'" Paragraph on oaaet Line 2 650. Section 9. 1.3.3, Page Please explain why the epistemic versions of the original GMPEs 9-8, Last Paragraph of are not included in Figures 9.1-19 and 9.1-20 to help judge the section appropriateness of the selected common-form models in capturing the CBR of the median motion 651. Section 9.1.4, page 9-Please express quantitatively what is meant by "nearby" (where 8. 1" paragraph of there are no known faults). and give the justification forneglecting section. line 1 directivity effects for identified faults outside that region (or specific reference to a report section that provides the justification). 652. Section 9.1 4, Page Please further clarify the statement "The GMPEs capture this 9-8. Line 6 random case" and how it supports the Tl Team's decision to give zero weight to the directivity adjustment branch 653. Section 9.1 5, Page Please indicate that the tectonic regime of the Wells earthquake is 9-9. 1st Paragraph, the same as for the PVNGS site region. but that the tectonic regime 2nd Sentence for the Japan earthquake is not. 654. Section 9.1.5.1. Page Without plotting residuals against the directivity parameter, it is 9-9. 2"0 Paragraph. difficult to form a definite conclusion regarding the existence or the Second Sentence level of the directivity effect. Please either add a plot to support the conclusion or revise the sentence to be less definite. 655. Section 9.1.5.1, page 9-9, 2"" paragraph, Please replace "with respect the" with "with respect to." line 5 656. Section 9.1.5.1, page PGV residuals are not shown in Figures 1-15 and 1-16. According to 9-9, paragraph 2, line Appendix I (Section 1.3.2, Second Paragraph), residuals in Figure I-5 15 are with respect to CY14 only, not to the four NGA-West2 GMPEs Also. residuals shown in Figure 1-16 are averages over six candidate GMPEs Please revise this paragraph to be consistent with Appendix I. 657. Section 9.1.5.1, Page Because the Wells earthquake occurred in the same tectonic regime 9-9, 2nd Paragraph of as the PVNGS site, its ground motion is very relevant to Section, Last understanding the ground motions that might occur at PVNGS from Sentence normal-faulting events. Please state what conclusions were drawn from the observations regarding the validity of the NGA-West2 GMPEs to estimate normal-faulting ground motions at the site. Please also indicate why neither the Bindi et al. (2014) GMPE nor response-spectral values in addition to PGA and PGV were evaluated 658. Section 9.1.5.2. Page Please clarify whether the definition of a complex rupture adopted by 9-9, First Paragraph, the Tl Team is applicable to the case of disjoint ruptures as seen in Line 1 the Fukushima-Hamadori earthquake. 659. Section 9.1 5 2. Page Please justify that the SSRS method is the preferred method for 9-9. First Paragraph. computing ground motion from the Fukushima-Hamadori Line 5 earthquake, given that the evaluation of alternative methods for complex ruptures (Section 6.7 and Sections J.2.2 and J.3.2) does not include disjoint rupture scenarios as seen in the Fukushima-Hamadori earthquake. 660. Section 9.1 52. Page Please explain why the Bindi et al. (2014) GMPE was not evaluated, 9-9. First Paragraph. given that it was one of the candidate GMPEs. Please also indicate if 4:n sentence the Japan regional factors in the NGA-West2 GMPES were used to evaluate the Fukushima-Hamadori. Japan earthquake. 661. Section 9.1 52. Page Please provide a figure similar to Figure 9.1-21 for the Wells 9-9, 1st Paragraph of earthquake. Section, 7th Line 662. Section 9.1.5.2, page Please consider whether an accessible document can be cited 9-9. 3'd paragraph of instead of personal communication, and if not. consider whether the section. line 2 observation cited is of real significance to the assessment. 663. Section 9.1.5.2, page The personal communication cited here entails a claim of local 9-10. 3'd paragraph of stress heterogeneities. without reference to a data source. and a section ( 1*1 on page). "suggestion" about rupture behavior that is difficult to distinguish from lines 9-14 simply an offhand speculation. Please consider first whether this passage is essential to the Tl Team's assessment. If so. please consider whether there is a documentary source for the observation of stress heterogeneity. Also consider whether stating a Tl Team judgment (based on review of the available evidence) that the event cannot be discounted (as an Arizona proxy) might be as authoritative. and more direct. than citing Dr. Stein's undocumented suggestion. 664. Section 9.1 5 2. page Please reference where in the report and/or appendices the 9-10, 4'" paragraph of additional variability gleaned from the evaluation of the Wells and section (2"" on page), Fukushima-Hamadori earthquakes is taken into account. 665. Section 9.2, Page 9-Please explain why the Sammon's mapping approach was not used 10, General to develop the set of models used to estimate ground motions from the distant California and Mexico sources in Regions 1, 2, and 3. Please also include figures to demonstrate the distribution of ground motion values that are implied by the logic-tree model that represents these sources. 666. Section 9.2.1, page 9-The phrases "California/Mexico" and "California -Mexico" should 10, paragraph 1 read "California and Mexico." 667. Section 9.2.4, Page Please specify the applicable distance range of Al-Atik and Youngs 9-11. First Paragraph, (2014) and comment on its applicability to 1he distant California and Line 4: Mexico sources. 668. Section 9.2 41. Page First Paragraph of Section 9.2.4 indicates that this section is about 9-11, 1" Paragraph of epistemic uncertainty in median prediction by the NGA-West2 section, Line 4 GMPEs, whereas this sentence and the remainder of this subsection indicate it's about uncertainty in the path effect. This is very confusing. Please clarify or reorganize as needed. 669. Section 9.2.4.1, page Please cite the relevant appendix section(s) and figure(s) where the 9-11 , 1" paragraph of details are given. section. lines 6-9 670. Section 9.2.4.1, page Please provide a reference and clear explanation for the equation. 9-12, Eqn 9.2-1 671. Section 9.2.5, Page A description of the standard deviation used by the Tl Team to 9-12. Second compute the 51to and 95" values is missing. Please provide such a Paragraph. Line 1 description along with Tl Team's justification for the value used. That description should also clarify why the weights stated at the end of Section 9.2.4.2 and elsewhere in the report differ (slightly) from the 0. 185. 0.63 and 0.185 weights used by Al Atik and Youngs (2014) and recommended by Keefer and Bodily. 672. Section 9.2.6, Page Please provide a reference for the statement that "The distant 9-12. 1st Paragraph of California strike slip sources are located at distances well beyond Section, 1st Line where directivity effects are observed in the empirical data". 673. Section 9.3, page 9-Please see previous comments regarding the list of references for 13, General comment other chapters and appendices for guidance on revising the list of references in this chapter. 674. Figure 9.1-1, page 9-The caption should include the information on the meaning of the 15 red and green weights (as discussed in the text), while noting that there are no statistical (green) weights present in this case. 675. Figure 9.1-2a, Page Please indicate the type of residuals (i.e., between-event, within-9-16, 5th Line of event, total) here and elsewhere throughout the chapter when the Caption term residuals" is used. 676. Figure 9.1-2 & 3, Please provide a label giving the color bar units. or provide that pages 9-16 to 9-19 information in the caption. 677. Figure 9.1-5, page 9-Please rewrite the caption to correct typographical errors and make 21 it more informative. 678. Figures 9.1-8, page 9-The caption in each of these figures should be corrected to read 24; and 9.1-9, page 9-..cumulative distribution function" Please also improve the readability 25 and resolution of these figures and several subsequent ones-they are fuzzy and the numbering is nearly illegible. 679. Figure 9.1-14a-e. All of the influence plots are fuzzy and need improved resolution. pages 9-30 through 9-Plus, the lettering is too small and illegible. The captions could be 34 improved with better explanations of the plots. CHAPTER 14 Hazard Sensitivity 680. General comment Subjective statements such as "main contributing, controlling, significant. small, little impact", etc. are used throughout the chapter to describe results. Please provide a quantitative description of such statements in order to avoid ambiguity. 681. Section 14.1, Page Please provide specific references (i.e., documents or presentations) 14-1, 1st Paragraph, to the hazard sensitivity studies that were provided throughout the 1st Sentence project. 682. Section 14 .1 . page The sensitivity estimates have been invoked at many points in the 14-1. 1"' paragraph report as a rationale for various model simplifications. Therefore. please consider adding a short discussion to further justify the validity of using the earlier SSC models for DCPP and PVNGS as the base case for this purpose (and emphasizing that the older models are used only for that purpose). 683. Section 14.1, page Has the acronym .. NPP" been defined. or even used at all elsewhere 14-1, 2,." paragraph of in the report? Please consider whether it is worth introducing this section. line 3 acronym and defining it here, in lieu of just writing out what it means. 684. Section 14.1, page If the term .. 1ornado plot" has not been defined earlier in 1he report. 14-1 , paragraph 3 of please provide a brief description of i1s form and construction If section. 3'" sentence there was an earlier definition given. please provide a specific section reference. Please also clarify that the y-axis value alluded to at the end of the sentence is that of the hazard curve. not tha1 of the tornado plot i1self. And since not all of the sensi1ivity studies are summarized in Tornado plots (e.g., the source contributions are shown as graphs and deaggregation histograms) please indicate that these other results are shown in other formats. 685. Section 14 .1 . page Please clarify the meaning of "weighted mean" in this context (e.g., 14-1, 3*d paragraph of how are the individual ratio values weighted?). section, line 6 686. Section 14.1. Page This statement implies that the results could be different enough to 14-2. last paragraph be of concern. In this case, please justify why it is sufficient to use of section (1st on the older SSC models for the hazard sensitivi1y studies. Please also page), Last Sentence consider moving this caveat and i1s discussion and justification to Section 14.1 at the beginning of the chapter as recommended in an earlier comment. 687. Section 14.2, page Here, and elsewhere in the report (e.g., Section 14.2, Page 14-4). 14-2, paragraph 1, please add "fault" after Shoreline. Los Osos. San Luis Bay. etc lines 2 & 6 These are formal names and should be spelled out in full. 688. Section 14.2, Page Please indica1e how the fractional contribu1ion of 1he different 14-2, 1st Paragraph of seismic sources to the total mean hazard was determined. If it was Section, 2nd done using deaggregation, please indicate that this is the case and Sen1ence define what deaggregation is and how it is done prior to discussing the results. 689. Section 14.2. Page Please indicate that the deaggregation is done on the mean hazard 14-4, 1st Paragraph here and elsewhere thought the chapter and appendices. on page, 1st Line 690. Section 14.2. Page Please also show the 10'" hazard deaggregation histograms for 14-4. 1st Paragraph completeness. on page, 1st Line 691. Section 14.2. Page Please explain how the deaggregation histograms show that the 14-4. 1st Paragraph hazard at DCPP is controlled by the four local faults when no on page. Last sources are identified in these plots. Sentence 692. Figures 14.2-3 and The entire report addresses hazard on a reference site condition 14.2-4, Pages 14-5 corresponding to Vs30 = 760 m/sec. Because of this. it is confusing and 14-6. Figure to describe the hazard as being for "rock". Please delete the word Captions rock to avoid confusion. 693. Section 14.2.1, Page Please change 14.3-6b to 14.2-6b 14-6, First Paragraph, Last Line 694. Section 14.2, Page Please consider revising the x-axis title in this figure and other 14-8, Figure 14.2-Sa similar figures in Chapter 14 to reflect the normalization of ground-motion ratio discussed in Paragraph 3, Page 14-1. 695. Section 14.2.2, page This sentence would benefit from minor rewording to avoid 14-11, paragraph 2, ambiguity. Please consider whether its meaning could be correctly last line on page rendered by " ... with the weighted average of the phi,, models, including only the central aleatory-variability branch on phi." 696. Section 14.2.2, page Please refer to specific figures when referring to .. the fifth line .. ". 14-12, 4'" paragraph This needs to be done throughout this section (next several of section (3"' on paragraphs) and the remainder of the chapter, as the absence of page). line 3 and specific references leaves some ambiguity as to which tornado plot elsewhere is being cited. 697. Section 14.2.2. Page The sensitivity of the mixture high model appears to be as great as 14-12, t' paragraph many of the other parameters. Please consider revising this of section (6th on statement to better reflect the results shown in the tornado plots. page) 7th Sentence 698. Section 14.3, page Please check to ensure that all of the names and abbreviations that 14-21, abbreviation are listed here are used consistently throughout the report. For lists instance, is Gulf of California referred to as GZ consistently (and not GC) and why is the -F added to CP for Colorado Plateau? This is potentially confusing. because CP is listed here for the Cerro Prieto fault (and it would seem more logical to have the F identifying a fault). Please also reference this list back to a figure. 699. Section 14.3. page Please revise this statement to make it clear whether the 99% 14-21, 1"' sentence contribution to the total hazard is from the background (area?) after bullet 11 sources. the fault sources. or the combination of both. 700. Section 14.3, page 14-22, 1"' paragraph after bullet 26, 1" line Please specify which faults are the distant fault sources. 701. Section 14.3, page Please clarify which modeling choices were made by LCI (2013) and 14-22, 1"' paragraph which ones were made by the Tl Team. Regarding those made by after bullet 26. 2"d and the Tl Team, please justify the choices made with respect to their 3'" sentences implications in identifying hazard-sensitive models and parameters. 702. Section 14.3. page Please be specific and precise about the meaning of the phrase ... a 14-22, 1*1 paragraph pure characteristic earthquake magnitude distribution .. :* as used in after bullet 26, line 7 this context 703. Section 14.3. page Please explain how the source contributions were calculated. 14-22, 2"* paragraph of page after bulle1ed items, 1" sentence 704. Section 14.3. page Please justify the use of the specific sigma value of 0.65. 14-22, 2"* paragraph of page after bulleted items, 4'" line 705. Section 14.3. page Please add the missing word greater" before than" in the phrase 14-22, 2"' paragraph "For ground motion values than 0.1 g." of page after bulleted items, line 7 706. Section 14.3, page If this paragraph is intended 1o be a summary of the results in 14-24, 1"' paragraph Figures 14.3-1 and 14.3-2, please explain how one reconciles the on page categorical statements in this paragraph with the period-dependent resul1s in 1he figures. For example, Figure 14.3-2 appears to indicate that $BR sources dominate 0.5 Hz hazard at levels exceeding about 0. 15 g, which appears to contradict the categorical statement that "distant fault sources are the dominant contributor to hazard at lower spectral frequencies:' Shouldn't the statements in this paragraph be conditional on something (e.g., the probability of exceedance range of interest)? Please also indicate whether this apparent contradiction is related to the observation made later in Section 14.3, Page 14-25, top 2 lines on page. 707. Section 14.3, page Please quantify what is meant by "local small"' and .. distant large** in 14-24, 2"' paragraph on page, 2"d and 3*d this context. sentence 708. Section 14.3. Page Please also show the 1ff" mean annual hazard deaggregation 14-24, 2nd Paragraph histograms for completeness. on page, 4th Sentence 709. Section 14.3. page This observation may be related to the above comment made about 14-25, top 2 lines on Section 14.3, Page 14-24, 1" paragraph on page. page 710. Section 14.3.1. page The phrase "there are not known active faults .. is at best an awkward 14-27, 2"* paragraph construction. and potentially ambiguous. Please reword for clarity. of section ( 1 ** on page), line 1 at top of page. 711. Section 14.3. 1, page Please provide reference to the report section where the neglect of 14-27, 2"' paragraph directivity effects was justified. of section ( 1" on page), top 2 lines on page 712. Section 14.3.1. page Please indicate what the statement "'little impact" is compared to. 14-27, 3*d paragraph of section (2"0 on page), 713. Section 14.3.1. page t4-27, 4'" paragraph of section (3"' on Please refer to specific figures that are related to this discussion. page) 714. Section 14.3.1, page The explanation of the greater range at lower hazard level in terms 14-27, 4'" paragraph of depth scaling requires some amplification. Please provide some of section (3'" on further explanatory remarks. page), lines 9 and to 715. Section 14.3. 1, page Please add the missing word *ior" in the phrase** .. to the hazard and 14-27, 4'" paragraph produce a floor the hazard estimate ... " of section (3"' on page), line 15 716. Section 14.3. 1, page Please revise this statement to clarify its meaning (i.e .. are the t4-27, 4" paragraph of section (3'" on values shown really "fractional" contributions?) page), last sentence 717. Section 14.3.1. page t4-27, 5" paragraph of section (4'" on Please refer to specific figures that are related to this discussion. page), general comment 718. Section 14.3.1. page Please consider rewording this sentence so as not to categorize the 14-27, 5'" paragraph GMPE prior estimate as a "dataset." The subject here is really of section (4'" on sensitivity to elements of the weighting scheme for the median base page), 1"' sentence models (Figure 9.1-5), only some of which are datasets. 719. Section 14.3.2. page Please provide a reference to the report section where the neglect of 14-31 , 1 *1 paragraph directivity effects was justified. of section. 2"0 sentence 720. Section 14.3.2, page Please refer to specific figures that are related to this discussion t 4-32, first 3 paragraphs on page 721. Section 14.3.2, page Please clarify where in the report the additional epistemic 14-32, 4'" paragraph uncertainty in the magnitude scaling is discussed and which node in of section (3"' on Figure 9.2-1 models this uncertainty. aaae), line 1 722. Section 14.3.2. page It should be clear at this point that the different model sensitivities 14-32, 4" paragraph are with respect to a common base case (i.e .. the denominator) and: of section (3'" on therefore. all represent changes in the numerator. Please remove page), line 3 this reference to the numerator in order to avoid confusion that these results are somehow different than the previous ones. 723. Section 14.3.2, page This sentence is poorly written (including seemingly redundant 14-32, 4'" paragraph constructions such as "approach application" and "in with"). Please of section (3"' on rewrite this sentence for clarity and precision. Also, please check page), lines 7 & 8 whether the "i.e." in the parenthetical note correctly conveys the intended meaning (ie .. the "i.e." implies some sort of equivalence between the preceding clause and the parenthetical observation. which mav not be intended). 724. Section 14.3.3, Page Please do not use a slash (e.g .. in the term the PhisslPhisr-R) unless 14-36, 1st Paragraph, it is intended to represent a ratio here and throughout the chapter. 2nd Line 725. Section 14.3.3. Page Please explain why the BSSA 14 GM PE was used for the sigma 14-36, 1st Paragraph, sensitivity studies and the CB14 GMPE was used for the median 6th Line sensitivity studies. 726. Section 14.3.3. Page Please provide, in the text, the spectral frequencies that are 14-36, 2nd associated with Figures 14.3-9 and 14.3-10. Paragraph, 1st Line 727. Section 14.3.3, Page This is the first time that the values of ratios are given. Please be 14-36, 2nd consistent in either providing such ratios or not providing them Paragraph, 4th Line throughout the chapter. If the ratios are not provided, the subjective statements describing these ratios should be quantified (see General Comment on this chapter). 728. Section 14.3.4 page Please reference specific figures related to this discussion. 14-41 , 3'" paragraph of section (1"' on aaae) 729. Section 14.3.5. page Please check whether "0.5 Hz .. should be "5.0 Hz." 14-46, 3*d paragraph of section ( 1" on page), line 1 730. Section 14.3.5, page Please describe the three models that are shown for the "with path" 14-46, 4:* paragraph and without path" rows in Figures 14.3-13a, 14.3-13b, 14.3-14a, and of section (2"" on 14.3-14b. page), 1*1 sentence 731. Section 14.3.5, page Please consider whether the intended meaning of this sentence 14-46, 4:* paragraph of section (2"" on would be better conveyed by .. because of' rather than "based on " page), line 4 732. Section 14.3.5. page This statement does not seem to be consistent with the figures. 14-46, 5:* paragraph Please revise this statement to better reflect the results shown in the of section (3"' on tornado plots. page), 6:* sentence 733. Figure 14 3-13b. page The caption reads correctly that this plot is for 5 hz (as stated in the 14-48 text) but the header of the figure reads O 5 Hz. Furthermore, the plot looks identical to Figure 14.3-14b. Please make sure this is the correct plot and either correct the header or replace it with the correct plot. 734. Section 14.3.7, Page Use of the term distribution is confusing. Please consider replacing 14-54, 1st Paragraph, "distribution" with sensitivity. 9th Line 735. Section 14.3.7. Page The NGA-West2 models only show significant sensitivity at 0.5 Hz, 14-54, 1st Paragraph, so this general statement is confusing. Please consider deleting this 101" Line sentence and making statements regarding the impact of these models separately for the two frequencies. 736. Section 14.3.7, Page Use of the term uncertainty is confusing. Please consider replacing 14-55, (1st uncertainty" with sensitivity". Paragraph, 3rd Line 737. Section 14.4, Page Please see previous comments regarding the list of references for 14-58, General other chapters and appendices for guidance on revising the list of references in this chapter. APPENDIX H Evaluation of Common Form Models 738. General The format of the appendix is different from that of the report and other appendices. Please reformat the appendix to be consistent with the rest of the report. 739. Chapter 1. General The text is very cryptic and contains a myriad of terms and acronyms. making it comprehensible to only those that have a good understanding of the topic. Please expand the text to be more descriptive and ensure that all of the used terms and acronyms have been clearly defined in the main report prior to referencing the appendix or. if not. that they are defined in the appendix the first time they are used. 740. Chapter 1. Tables 1.1 The table captions should specify units for the ground motion levels. and 1.2, page 2 741. Chapter 1, Section Please indicate what the GMPEs are used for See also 1st Line of 1.1, Page 1, 4th 5th Paragraph. Paragraph, 1st Line 742. Chapter 1, Section Please replace "(2014)" with "(2014a.b)" in the Akkar et al (2014) 1.1, Page 1, 4th reference to indicate that both the original manuscript and the Paragraph, 2nd Bullet erratum were published in the same year and add the reference to the erratum in the list of references. See also 3rd Bullet in 5th Paragraph. 743. Chapter 1 , Section Zhao and Lu (2011) do not present a GMPE, but rather an approach 1.1, Page 1, 4th to magnitude-scaling at large magnitudes. Please define a new Paragraph, 8th Bullet GMPE that incorporates the proposed magnitude-scaling in Zhao and Lu (2011) and identify it by a unique acronym. 744. Chapter 1, Section Please replace "(2014)" with "(2014a.b)" in the Bindi et al. (2014) 1.1, Page 1, 5th reference to indicate that both the original manuscript and the Paragraph, 3rd Bullet erratum were published in the same year and add the reference to the erratum in the list of references. 745. Chapter 1. Section Please add the missing word not" in the phrase "but do 1. 1.1, page 3. paragraph 1 . 2"d to incorporate". last line 746. Chapter 1. Section Please justify the basis for the weights assigned to the median and 1. 1. 1, Page 3, 2nd plustminus uncertainty of the GMPEs. Paragraph, 7th Line 747. Chapter 1, Section Please define the meaning of the term "total weights". 1. 1. 1, Page 3, 3rd Paragraph, 1st Line 748. Chapter 1, Section Please avoid the use of slashes (e.g .. in widthlrange) unless it is 1.1.1, Page 3, 3rd intended to represent a ratio. Paragraph, 3rd Line 749. Chapter 1, Section Please define the meaning of the term "all weights" and how it differs 1.1.1. Page 3. 7th from the term "total weights". Paragraph, 2nd Line 750. Chapter 1. Section Please reference the logic tree that documents the weights that are 1. 1. 1, Page 3, 8th assigned to Models A and B for PVNGS. Paragraph, 2nd Line 751. Chapter 1. Section Please update the references to the various datasets to use the 1. 1.1, page 3. 81" terminology introduced in Chapter 5. and reference the appropriate paragraph. line 5 section and table from that chapter. If the term "weighted NGA dataser is not explained in Chapter 5, please explain that term here. 752. Chapter 1, Section Please clarify what "those" refers to in what appears to be part of an 1.2, Page 5, 1st incomplete phrase. Paragraph, 1st Line 753. Chapter 1 , Section Please provide references to the simulation methods of EXSIM, 1.2, Page 5, 1st Graves and Pitarka (i.e., G&P), and SDSU. Paragraph, 3rd Line 754. Chapter 1 , Section Please clarify what "models" are being referred to 1.2, Page 5, 1st Paragraph. 5th Sentence 755. Chapter 1. Page 7. Please ensure that all of the references are cited in the text and are Bibliography complete. and add missing references identified in the text. 756. Chapter 2. General Please provide a short introduction to the figures that are presented in the report. 757. Chapter 2, Section Please provide uni1s for the legend bars in the figures showing the 2.1.2 Sammon's maps. 758. Chapter 2. Section Please explain why the distribution of hazard curves for the selected 2.1.4 models covers a smaller range of hazard than that for 1he 2000 curves and what impac1 that has on the final results. 759. Section 2.1.4. Page To help visually compare the hazard distribution from the selected 53, Figure 2.69 model to the distribution from all 2000 sampled models. please add the 5%. 50%. and 95% curves of 1he latter distribution to both plots. Also please increase the size of each plot for ease of viewing. 760. Chapter 2. Section Please define the acronyms in the legend that are used to describe 2.1.5 the GDF curves in the figures. Also please change "cumulative density function** to "cumulative distribution function" in all captions. here and 1hroughout the report. 761. Section 2.1 6, Page Please explain what causes the ramp-up of the lower black curve on 106. Figure 2.202 this figure and other figures. 762. Section 2 .1 . 7, Page Please explain what causes the ramp-up of the lower red curve on 107, Figure 2.208 this and other figures. 763. Section 2.1.81.4.7, Please explain why, a1 Rx= -1, the GMPE distribution is much more Pages 137 and 140, sensitive 1o the value of F (s1yle-of-faulting flag) than the Model A Figure 2.272 vs. distribution is. Figure 2.281 764. Chapter 3. General Please see comments for Chapter 2. 765. Chapter 4, General Please see comments for Chapter 2. 766. Chapter 5. General Please see comments for Chap1er 2. APPENDIX I Wells (NV) Earthquake 767. Section 1.1, Page 1-1. Please provide a reference for 1he statement that "The tectonic 2nd Paragraph. 1st setting. magnitude. and focal mechanism of this earthquake are all Sentence consistent with the seismic sources in the Southern Basin and Range that contribute significantly to the hazard at high frequencies at the Palo Verde Nuclear Generating Station (PVNGS)"'. 768. Section 1.1, page 1-1. The acronym" NGA-W2" was given as "NGA-West2 .. elsewhere in 2"' paragraph, line 5 the report. Please standardize the terminology and acronyms throughout the report. 769. Section 1.2.1. Page 1-Please provide a summary of instrument response, sampling lime 1. 1" Paragraph of interval. and possible limitations of the USTA recordings for use in section. Line 7 the comparison with GMPEs described in Section 13. 770. Section 1.2.1, page I-US Transportable Array is abbreviated "USTA" here. while 1. 1"' paragraph, line 7 elsewhere it is referred to as 'Transportable Array" and abbreviated as "TA". Please standardize the terminology and acronyms throughout the report. 771. Section 1.2.1, page I-Please clarify the meaning of the term "temporary stations". If these 1. 1" paragraph, line 8 temporary stations are the USTA stations. please indicate such in the text. 772. Section 1.2.1, page I-Please add either a period or semicolon following "100km". 1. 1"' paragraph, last 2 lines 773. Section 1.2.2, Page I-Please clarify that the Wills and Clahan (2006) relationships 2, 2nd Paragraph, 1st between geologic units and Vs30 are based on California data and Line geology and might not be appropriate for Nevada. Please also discuss the potential significance of this assumption on the results 774. Section 1.2.2, Page I-Please provide units for the Vs30 values of 600 and 750 m/s. 2. 2nd Paragraph. 1st Sentence 775. Section 1.2.2, Page I-Please explain why there is no proxy Vs30 value for Station M 12A 2, 2nd Paragraph, 2nd shown in Figure 1-2. Later in the text it is noted that this station Sentence clipped and was not used, but that information is not available at the point in the appendix where this figure is referenced. 776. Section 1.2.3, page I-The record for station N12A also looks clipped in Figure 1-3. Please 2. 1 "' paragraph of consider whether that is the case. and if so. whether it is appropriate section. line 7 to comment on that record as well, in order to be consistent. 777. Section 1.2.3, Page I-Please explain why a focal mechanism from UCB was used rather 2, 1st Paragraph of than one from a more local source (e.g., 1he UNR Seismological Section, Last Laboratory), or from the study of Dreger et al. (2011) or the USGS Sentence NEIC. 778. Section 1.3.2, Page I-Please add the references for Abrahamson et al. (2014), Boore et al 3, 1st Paragraph of (2014), Campbell and Bozorgnia (2014), Chiou and Youngs (2014), Section, 2nd and Idriss (2014) to the list of references. Sentence 779. Section 1.3.2, Page I-Please replace "2013 (ASB13)" with "2014a,b (ASB14)" and add the 3, 1st Paragraph of Akkar et al. (2014a,b) original manuscript and erratum to the list of Section, 2nd references. Sentence 780. Section 1.3.2. Page 1-Please replace "2013 (BIN13)" with "2014a,b (Bi14)" and add the 3. 1st Paragraph of Bindi et al. (2014a.b) original manuscript and erratum 1o the list of Section, 2nd references. Sentence 781. Sec1ion 1.3.2, Page 1-The statement that the NGA models are a better short-period fit than 3. 3*d paragraph. last the Euro models does not seem correct without a more specific line s1atement of 1he period range (e.g .. it appears that the absolute value of the average residual is similar between NGA and European datasets up to a period of -0.05 seconds). Please formulate the conclusion more precisely. 782. Section 1.3.2. Page 1-This paragraph summarizes the observations of the analysis given in 3, 4th Paragraph of Appendix I, but does not provide conclusions whether the Wells Section earthquake data indicate tha1 there is a po1ential issue with 1he applicability of 1he NGA-West2 or European GMPES to the greater Arizona region. Please provide conclusions based on the observed comparison shown in this appendix and demonstrate, perhaps statistically. whether the Wells ground-motion data is consistent with the empirical GMPEs over the period range of interest 783. Section 1.4, Page 1-3 Please revise the list of references to include missing references and 1o update those references 1hat have incomple1e informa1ion 784. Figures 1.1 1o 1.14 Please provide missing or more meaningful figure captions. 785. Figure 1.15, Page I-Please indicate that these residuals were calculated with respect to 19, Caption the CY14 GMPE. 786. Figures 1.16, Page I-Please indica1e that the mean residuals are calcula1ed with respect 20, Caption to all 7 sites in the upper plot and provide a description of what is shown in the lower plot. APPENDIX J Forward Finite Fault Simulations for SWUS 787. General There are a lot of analyses being described in this appendix, some of which are attributed to unspecified authors or by the pronouns "I", "we", "our", etc. Please indicate who performed the analyses (e.g., the Tl Team or some o1her Resource or Proponen1 Expert) and avoid the use of pronouns, which refer to unspecified authors of the appendix. 788. General comment This appendix deviates stylistically from others, in that some subsections are given headers but left unnumbered. For example, within Section J.2.2. on Page J-10 there is a heading .. Scenario 1: Hosgri that is unnumbered, whereas following convention established in other chapters this should have become Section J.2.2.1. Please edit the chapter for uniformity of style with the rest of the reoort 789. Section J .1 , page J-1 . Please include a reference describing the SCEC Broadband Line 1 Platform. For example. a suitable paper would be that published (SRL early online publication for Jan 2015 issue). by Maechling et al. Also please define acronyms (such as SCEC) the first lime they are used, here and throughout the appendix. 790. Section j. 1, page J-1, For the sake of parallelism of construction. "and extending GMPE" Line 4 should read "and to extend GMPE." 791. Section J.1, Page J-1, Please include additional text in this sentence to reflect the use of Line 5 simulated data by the Tl Team in Chapter 8 to select and assign weights to the selec1ed models for DCPP (Figure 8.2-2). Also. please add a summary, including tables, of the fault parameters used to obtain the Chapter 8 simulated data, or reference the section where such a summary is provided. 792. Section J.1.1, Please explain whether the validation process uses a performance General measure that specifically evaluates the capabili1y of simulation methods in modeling hanging wall effects. If not, please explain the Tl Team's basis for trusting the HW factor derived from the simulations. 793. Section J.1.1, page J-The acronym "G&P" is given as "GP" elsewhere. Please use a 1. 1 "' paragraph of consisten1 acronym throughout the report. section, line 7 794. Section J.1.1, page J-In addition to the cited report, there is a peer-reviewed publication in 1, 1" paragraph of (SRL early online publication for Jan 2015 issue) by Dreger et al, section line 8 describing the BBP methods review, which could usefully be referenced here. The individual BBP methods each have individual peer-reviewed papers in the same SRL issue, and these should be cited as well. 795. Section J.1.1, Page J-There were issues attempting to open the URL from the link given in 1. 1st Paragraph of the appendix, although it worked when pasted into Microsoft ln1erne1 Section, Last Explorer. Please correct this link or indicate that it should be pasted Sen1ence into a web browser. 796. Section J.1.1, Page J-The pseudo spectral acceleration (PSA) referred to here is also 1. 2nd Paragraph of referred to as RotD50 spectra elsewhere in the appendix. Please Section, 2nd Line choose a single 1erm for PSA and use it consistently throughout 1he appendix and, preferably, the report and other appendices for con sistencv. 797. Section J.1.1, Page J-Please provide references for the NGA-West1 project and the 1. 2nd Paragraph of specific NGA-West1 GMPEs that were used for the Part B validation. Section, 3rd Line 798. Section J.1.1, Page J-Please provide a reference and/or link to the SCEC BBP workshop 2. 1"' Paragraph on proceedings. page, 1st Line 799. Section J.1.1, Page J-Please indicate the specific "appendix" that is referred to. 2, 1" Paragraph on page, last line 800. Section J.1.1, Page J-This excerp1 from the panel report needs clarification as indicated in 2, 2"" paragraph on subsequent comments, even if that requires a format different from a page, general verbatim quote. If one or more direct excerpts are nonetheless comment retained. please use quota1ion marks and indentation 1o distinguish paragraph-length quotations from the main text, and quotation marks to distinguish brief ones. 801. Section J.1.1, Page J-Please clarify this statement by replacing .. residual .. with "value of the 2, 2nd Paragraph on residual". page, 2nd Line 802. Section J.1.1, Page J-Please clarify the specific meaning of "performance" here and in 2. 2nd Paragraph on Item 4. page, 7th Line 803. Section J.1.1, Page J-Please clarify the meaning of the phrase "equally combining the 2. 2nd Paragraph on absolute value of mean bias with the mean of the absolute value of page. 2nd Numbered the bias". which is somewhat confusing as stated Item 804. Section J.1.1, Page J-Please explain why the period range 0.01 to 3 sec is deemed 2. 2nd Paragraph on acceptable for validating the finite-fault simulation methods. page, Last Line 805. Section J.1.1, page J-Please consider whether the parenthetical comment is necessary, 2, 3*d paragraph on and if so. whether the point being made could be clarified. The point page, line 3 of the corresponding comment in the SCEC report was only to place the 0.35 natural log unit threshold in context, by comparing it to the amplitude effect of a 0.1 unit magnitude shift in the limit of large distance and long period. 806. Section J.1.1, Page J-Please provide a reference for the SCEC review report." 2, 3rd Paragraph on page, 6th Line 807. Section J.1.1, Page J-Please explain why the specific ranges of distances and magnitudes 2. 4th Paragraph on were selected for the Part B validation. page, 2nd Line 808. Section J.1.1, page J-2, 4'" paragraph on page, 2"d sentence Please replace "NGS-West 1" with "NGA-West1". 809. Section J.1.1, Page J-Please define these acronyms the first time they are used and 2, 4th Paragraph, 2nd replace the year with only the last two letters of the year to be Sentence consistent with how these acronyms are defined elsewhere throughout the report and appendices. 810. Section J.1.1, page J-The description of the upper and lower acceptance thresholds is 2, 4'" paragraph on ambiguous. Please provide a more precise description. page, 3'" and 4:n sentences 811. Section J.1.1, Page J-Please indicate what "appendix" is being referred to. 3, 1st Paragraph on page, Last Line 812. Section J.1.1, Page J-Please provide the numerical values of the validation magnitude 3. 2nd Paragraph on range. page, 3rd Line 813. Figure J.1.1-1:, Page The bias threshold of 0.69 In units is not discussed in the text at this J-4. Caption. 3rd Line point in the appendix. Please define why this threshold was selected and how it is used when the figure is first discussed in the text. 814. Figure J. 1. 1-2:, Page The stated factor of 1.15 applies to extending the maximum value J-5, Caption, 4th Line but not the minimum value. Please indicate what factor (less than one) was used to extend the minimum value. 815. Section J.21, Page J-Please define the terms and units in the magnitude-area scaling 6, 1st Paragraph of relationship of Leonard (2010). section, Last Line 816. Section J.21, Page J-Please replace "Graves and Pitarka" with "G&P .. to be consistent 6. 2nd Paragraph of with the use of this acronym elsewhere throughout the report and section. 2nd Line appendices and use it consistently throughout the appendix, which also sometimes refers to G&P as GP. 817. Section J.21. page J-Please correct the extraneous words "A of' at the beginning of the 6. paragraph 2 of last sentence of the section. section. line 4 818. Figure J.2.1-1, Page Please also show the M7 scenario on this plot and indicate what dip J-7 angle is used to make the plot. 819. Section J.21, Page J-Please explain why there is no dip variation for the M 7 scenario. 8. Table J.2.1-1 820. Section J.2.2, page J-Please provide a reference to the report section where the precise 9. paragraph 1. line 1 definition of a "complex" rupture scenario, as used in this project, is given. 821. Section J.2.2, page J-Please consider whether the reference to personal communication is 9, paragraph 1, line 2 appropriate in this context, or whether ii would be sufficient to note that the simplified scenarios were developed by the SSC project. 822. Section J.2.2, page J-The first sentence of the paragraph states that two complex 9. paragraph 1. line 4 scenarios were considered. but the list on this line contains three. including a Hosgri-Shoreline scenario that appears to be a splay scenario. Please check and make any appropriate corrections. 823. Section J.2.2, Page J-Please define the parameters "L" and .. W" the first time they are 9, 1" Paragraph, 6th used. Line 824. Section J.2.2, page J-The final sentence of the paragraph cites a personal communication 9. paragraph 1. last 2 for the approach to scaling the simulation parameters. Please rewrite lines this sentence to make it clearer that the Tl Team made the judgment to follow this approach. in light of its technical assessment of the alternatives and its consideration of the specific ways in which the simulations are used. 825. Section J.2.2, page J-Please add the missing word .. that" in the phrase .. except for." 9, of section, 2" line after equations 826. Section J.2.2, page J-Please clarify the intended meaning of the phrase "shortening a 9. 2"d paragraph of fault". If, for example, it means shortening it relative to the length section, 5'" and 6:" assigned in the SSC. that should be made explicit. Also clarify the lines after the intended meaning of the word "lowered" with respect to the northern equations endpoint [of the fault]. 827. Section J.2.2, page J-This sentence has several issues that should be corrected. (1) 10, paragraph of Please revise the awkward and ungrammatical (in this context) section (1*1 on page). construction "instead of attempting to predict realistic ground 1*1 sentence on page motion." (2) Please consider whether .. realistic ground motion" is the right contrast to draw with "relative" ground motion (e.g., would "absolute .. ground motion level be more appropriate?). (3) The caution against using the simulations for absolute ground motion levels appears to contradict the use of simulated ground motions in Chapter 8 to evaluate the common-form models. Please rewrite this sentence to clarify the intended meaning and resolve the apparent contradiction. 828. Section J.2.2, page J-Later in this section, when splay scenarios are discussed, the 10, heading of 41h corresponding headings start with .. Splay Scenario " The structure of paragraph of section the discussion would be more parallel and clearer if this heading (line 4 on page) were changed to "Complex Scenario 1 : Hosgri-Los Osos:* Please also include a section number for this and other similar subsection headings in the appendix, for easy reference and stylistic consistency with the other sections of the report. 829. Figure 2.2-1. Page J-Please show the surface projection of the inferred rupture plane of 10 the dipping reverse fault(s) in this and similar figures in the appendix. 830. Section J.2.2, page J-Please indicate (e.g .. in the table caption) which (Hosgri or Los 10, Table J.2.2-1 Osos) is segment 1 and which is segment 2. 831. Section J.2.2, page J-Later in this section. when splay scenarios are discussed. the 11, heading at top of equivalent headings start with "Splay Scenario." The structure of the page discussion would be more parallel and clearer if this heading were changed to "Complex Scenario 2: Shoreline-San Luis Bay." 832. Section J.2.2, Page J-The length of the Shoreline fault plotted in this figure seems to be 11, Figure J.2.2-2 and much shorter than the length listed in Table J.22-2. Please check Table J2.2.-2 and revise as needed. 833. Section J.2.2, page J-Please indicate (e.g., in the table caption) which (Shoreline or San 11, Table J.2.2-2 Luis Bay) is segment 1 and which is segment 2. 834. Section J.2.3, page J-If the rupture scenarios were defined by the DCPP SSC Tl Team. 11, 1'1 paragraph, 1sl2 please indicate that explicitly. lines 835. Section J.2.3, page J-Please justify why the Tl Team made the judgment to select 12, 2,." paragraph of scenarios consistent with the Leonard relationships (e.g., is there a section (1"1 on page), connection with the way the models were validated?). lines 4 & 5 836. Section J.2.3, page J-Please clarify which research goals were facilitated by the 12, paragraph of modifications described and how the results ultimately feed into the section (1"' on page), GMC model. Last 2 sentences of paragraph 837. Section J.2.3, page J-Please check whether the intended meaning would be better 12, 4'" paragraph of conveyed by using "each case" in place of "both cases." section. line 1 838. Section J.2.3, page J-Please explain the meaning of1he phrase scaled that slip by 30%," 12, 4'" paragraph of and give the justification for selecting the vaue 30%. section (3'" on page), 3'" and 4*h sentences 839. Section J.2.3, page J-Please clarify whether .. this slip" refers to the slip on the secondary 12, 4'" paragraph of fault. section (3'd on page). 5'h line 840. Section J.2.3, page J-Please check whether this line should read "Los Osos-San Luis Bay 12, 5'" paragraph of splay scenario" and correct if appropriate. section on page). Line 1 841. Section J.2.3, page J-This sentence is confusing because of the ambiguity of the word 12, 5'" paragraph of "meet" in this context (i.e .. the word does not indicate which fault is section (3'd on page). cut off by the "meeting"). Please consider whether the intended Line 5 meaning would be better indicated if meet" were replaced by "abut". 842. Section J.2.3, Page J-Please explain how exactly the process described in this sentence 13, 1st Paragraph, was done, which is somewhat confusing as stated. 2nd Sentence 843. Section J.2.3, page J-This sentence repeats nearly verbatim that of Section J.2.2, Page J-13, paragraph 8 of 10. 3*d paragraph of section. and the same comment applies and is section (4"' on page) repeated here. This sentence has several issues that should be corrected. (1) Please revise the awkward and ungrammatical (in 1his context) construction "instead of attempting to predict realistic ground motion." (2) Please consider whether "realistic ground motion" is the right contrast to draw with "relative" ground motion (e.g., would "absolute" ground motion level be more appropriate?). (3) The caution against using the simulations for absolute ground motion levels appears to contradict the use of simulated ground motions in Chapter 8 to evaluate the common-form models. Please rewrite this sentence to clarify the intended meaning and resolve the apparent contradiction. 844. Section J.2.3, page J-The phrase "Complex Scenario Z' should read "Splay Scenario 2". 14, heading following Table J.2.3-1 845. Section J.2.3, page J-"Shoreline-San Luis Bay splay" should read "Los Osos-San Luis Bay 14, 1 *1 line after the splay". Please correct. heading 846. Section J.3, Page J-Please indicate if "spectra" refers to Fourier amplitude spectra or 15, 1st Paragraph, 4th PSA spectra or both and whether the RotD50 component applies to Bullet Item, Last Line PSA here and elsewhere throughout the appendix. Note a previous comment to use a consistent definition for the PSA spectral values referenced throughout the appendix and to define the term "RotD50" the first time it is used. 847. Section J.3.2, Page J-Please explain what an SRF file is the first time the term is used. 16, Second Paragraph. Line 3 (Item 2) 848. Section J.3.2, Page J-Please explain what each of the "two pieces" of the $RF file 16, 3rd Numbered represents. Item 849. Section J.3.2, page J-Please use some alternative language in place of the personal 16, paragraph 3 of pronoun "I" in order to better reflect the Tl Team's collective section ( 1*1 paragraph intellectual ownership of the model and maintain stylistic consistency after the list), Line 2 throughout the report. 850. Section J.3.2, page J-The meaning of this sentence is not clear. Please rewrite it to clarify 16, 5'" paragraph of how ExSim solutions for the component segments were combined. If section (last the GP and SDSU simulations were applied in some way as part of paragraph on page). the ExSim procedure. the explanation should clarify what "properties" 2"* sentence GP and SDSU provided. and how those properties were matched by the ExSim procedure. 851. Section J.3.2, page J-The time delay appears to represent the delay between initial 16 5'" paragraph of rupture on the initial segment and arrival of that rupture at the section (last on page). junction of the fault segments. If that is the case. the relevant velocity last sentence would be the rupture velocity, not the S wave velocity Vs. If this reasoning is correct, please modify the notation "Vs" to be more appropriate for representing a rupture velocity instead of the wavespeed. If it is not. please clarify. In either event, please rewrite this sentence to be explicit about what was done. That is, instead of using the ambiguous qualifier based off', state explicitly what was calculated to obtain the delay time. 852. Figure J.3.2-1. Page Please describe the meaning of the colored shading on these and J-17 similar plots in 1he appendix. 853. Section J.3.2, page J-The use of quotation marks on factors" is not appropriate (it is not a 17, 6'" paragraph of meta-reference to the word "factors"), and because the quantities section ( 1*1 on page). defined here are used repeatedly in an important role in this section. line4 the clarity would be significantly improved if they were given a distinctive name, with the name then used consistently throughout the discussion that follows. 854. Section J.3.2, page J-The factors obtained from rules for defining GMPE input parameters 17, 6'" paragraph of appear to be different quantities than the factors defined earlier in the section ( 1*1 paragraph paragraph. and the use of the same term "factor" for both (especially on page), line 9 since the term "factor" is not distinctive to begin with) is a source of confusion. Please clarify the discussion later in the chapter by giving the ratios obtained from these GMPE rules a distinctive name. different from that used for the simulation ratios 855. Section J.3.2, page J-The characterization of the process as "already quite convoluted" is 18, 7'" paragraph of redundant. Please consider deleting that phrase. In fact, the entire section (1*' on page). sentence could be replaced by beginning the subsequent sentence 1 *1 sentence with "For complex scenarios with both a strike-slip and reverse component. it was required." 856. Section J.3.2, page J-Please elaborate on what "separated" means in this context and how 18, 7'" paragraph of section (1*' on page). this separation is conducted and the results verified last sentence 857. Section J.3.2, page J-Please explain what this paragraph contributes to the description or 18, 8'" paragraph evaluation of the GMC model or delete it. on page) 858. Figure J.3.3-1, Page Please define the acronyms used in the legend of the plot. J-19, Caption 859. Section J.3.3, page J-This sentence is similar to that of Section J.3.2, Page J-16 5:" 20, 3'" paragraph of paragraph of section (last on page). last sentence. and the same section (1*1 on page). comment is repeated here. The time delay appears to represent the line 6 delay between initial rupture on the initial segment and arrival of that rupture at the junction of the fault segments. If that is the case, the relevant velocity would be the rupture velocity. not the S wave velocity Vs. If this reasoning is correct. please modify the notation "Vs" to be more appropriate for representing a rupture velocity instead of the wavespeed. If it is not, please clarify. In either event, please rewrite this sentence to be explicit about what was done. That is. instead of using the ambiguous qualifier "based off'. state explicitly what was calculated to obtain the delay time. 860. Section J.3.3, page J-Please remove the inappropriate quotes from "factors" (but see 21, 4" paragraph of previous comment recommending use of a more distinctive section ( 1*1 on page). terminology). and correct the redundancy in the phrase "we 1"' and lines on computed factors computed for." oaae 861. Section J.3.2, Page J-If "plant site" refers to the "DCPP site", please replace the former 21 , 1st Paragraph, with the latter. If the intended meaning of the phrase is different. 2nd Line please supply the intended meaning. 862. Section J.4, Page J-Please avoid the use of the term "proponent models" here and 21, Section Heading elsewhere throughout the appendix, which can be confused with the term proponent models and/or methods proposed by Proponent Experts, as defined in the SSHAC guidelines. 863. Section J.4, Page J-Since much of the text in this section is virtually the same as the text 21, General in Section 6.7, please refer to the comments on Section 6.7 for revising the similar text and figure captions in this section. 864. Section J.4, Page J-Please clarify whether this always leads to an increase in ground 22, 2,." Paragraph of motion. section, Line 2 865. Section J.41, page J-Please consider whether the intent of this line would be better 23, 1*1 paragraph. line conveyed by the phrase "Four methods were evaluated for 1 computing" in place of the phrase "four methods were used to comoute." 866. Section J.4.1, page J-Please define the variables used in the equation. and, for 23, 2,." paragraph of consistency with other parts of the report, change "Sa" to "PSA." section, unnumbered equation 867. Section J.41, page J-The quotation marks on average" are inappropriate. If the word 23, paragraph of "average" without quotes doesn't communicate the intended section, 3'" line after meaning, please use a word that does (e.g .. "representative"). the equation 868. Section J.41, page J-24, 4" paragraph of section (1*1 on page). Please define the variable 'R" line 2 869. Section J.4.1, page J-Please define the variables used in the equation and clarify the 24, 4'" paragraph of nature of the summation. section (1*1 on page). unnumbered equation 870. Section J.41, page J-Please consider whether the intent of this sentence would be better 24, 1 *1 line after the conveyed by the phrase "The GMPEs are then applied using" equation instead of the phrase 'The GMPEs use the .. , since the latter could be misinterpreted to imply that the subsequent part of the sentence is a defining feature of the GMPEs. 871. Section J.4.1, page J-The meaning of this line would be clearer if the sentence began by 24, last paragraph of indicating explicitly that the method applies the GMPEs with the section, 1" line predictor variables as defined in the balance of the sentence. Please clarifv this line. 872. Section J.4.2, Page J-Please revise the sentence so that it is clear that **so degree" refers 24, 2r* paragraph of to the fault dip. section. line 1 873. Section J.4.2, page J-Please specify that "method., refers to "ground motion simulation 25, paragraph 4 of method." The distinction is necessary because four methods for section (last on page). assigning GMPE predictors are also discussed and need to be line 1 differentiated from the numerical ground motion simulation methods. 874. Section J.4.2, page J-Please clarify this line by specifying that the spectra are obtained 25, paragraph 4 of from the GMPEs using each of the four different methods for section (last on page). assigning predictor variables. line 2 875. Figure J.4.2-1. Page Please correct the acronyms in the plot legends to conform with J-26 those used elsewhere throughout the report and appendices (i.e., "ASK 14" instead of .. ASK'13"). Also, please check the accuracy of the "grey., curve that has a nearly "flat" zone from 0.5 to 1 Hz and. if correct, explain why this GMPE is used given such strange behavior. 876. Section J.4.2, page J-There are no gray lines in Figure J.4.2-3, nor are the colors of the 26, paragraph 5 of section (1*1 on page). dots explained. Please correct line 2 877. Section J.4.2, page J-As noted in an earlier comment. the discussion of complex and splay 26, paragraph 5 of adjustments would be easier to follow if the simulation factors and section (1"1 on page), GMPE factors had different, distinctive names used consistently line 2 throughout the chapter. Furthermore. the GMPE factors have not been explicitly defined. and although the meaning can be inferred from the context pretty well, ii would be clearer if they were explicitly defined when the concept was first introduced. Please consider introducing better terminology and more explicit definitions for these "factors". 878. Section J.4.2, page J-Figure J 4 2-3 does not appear to show what is claimed. maybe 26, paragraph 6 of because the gray lines mentioned in the text and caption are not section (2"c on page). visible. line 2 879. Figure J.4.2-3, Page There are four GMPE methods but six differently colored dots J-28 Please indicate what the different colored dots represent both here and in similar plots in the appendix. 880. Section J.4.2, page J-The statement that the magnitude is based only on the area of the 29, 9'" paragraph of Los Osos fault in Method 1 for the Hosgri-Los Osos scenario is section (t*1 on page). confusing. The problem is that the statement can be misinterpreted last sentence to suggest that the magnitude of the scenario changes depending upon the method of ground motion calculation. However, what actually changes is just the predictor variable M that is input to the GMPE. Please keep this distinction clear in the discussion. 881. Section J.4.2, page J-Please revise this sentence so that it is clear "70 degree" refers to 29, 10'" paragraph of the fault dip. section (2"' on page), Line 1 882. Section J.4.2, page J-This figure citation appears to be in error, as this is no Figure J.22-29, 10'" paragraph of 3. Please check whether the citation should be to Figure J.2.2-2 and section (2"c on page), make the appropriate correction. Line 2 883. Section J.4.2, page J-Please check whether the cited table should be J.2.2-2 instead of 29, 10 paragraph of J 2.2-3. section (2"" on page), Line 3 884. Section J.4.2, page J-The word "one" just before the comma is ambiguous. Please clarify 29, 11'" paragraph of whether the meaning is all periods except for one period" (in which section (last on page), case indicate which one), or if it is "all periods except for T= 1 last line on page second." 885. Section J.42, page J-The gray lines are not visible in Figure J.4.2-6, nor are the symbols 30, 13'" paragraph of explained. Please correct this. section (2"" on page). Line 1 886. Section J.4.2, Page J-If this sentence is intended to refer only to Methods 2. 3. and 4, but 32, 2nd Paragraph, not Method 1, please replace the phrase each of these methods" Last Sentence with "each of Methods 2, 3, and 4." 887. Section J.4.2, Page J-Please expand this paragraph to summarize quantitatively the 33, 1st Paragraph on justification for accepting Method 1 for the complex scenarios. page, 1st Sentence 888. Section J.4.3, page J-Please cite a published report or journal article for the observation 34, 4** paragraph of that the GMPEs have stronger distance saturation than the ExSim section (t*' on page). model Then the result mentioned here (regarding ExSim peak line 5 amplitudes) can be stated as a consequence of that fact (perhaps one pointed out by Dr. Atkinson to the Tl Team), rather than something to be taken purely on the authority of an unpublished comment by Dr. Atkinson. 889. Section J.4.3, Page J-Please reference the figure where the comparison referred to in this 35, 2nd Paragraph on sentence is shown. page, 1st Line 890. Section J.4.3, Page J-Please explain quantitatively the basis for the statement that 37, 2nd Paragraph on "Overall, GMPE Method 1 RotD50 spectra provide the best page, Last Sentence agreement with the simulation results". 891. Section J.4.3, page J-Please reference the figure where the comparison referred to in this 39, 1*1 paragraph on sentence is shown. page, 1*1 line 892. Section J.4.3, page J-In Figure J.4.3-6. the colors are not explained nor are the panels 39, 1*1 paragraph on labeled nor explained in the caption. Please correct this. page, last line 893. Section J.51, Page J-The magnitude ranges specified in this sentence disagree with those 41, Last Sentence of specified elsewhere in the report and also disagree with those section described in the publications of ASK 14 and CB14. Please revise as needed. 894. Section J.5.2, Page J-Please clarify that only the NGA-West2 HW terms are used and that 41, 3rd Paragraph of these terms are applied to the footwall model developed from the Section, 1st Line simulations. 895. Section J.5.2, page J-Please distinguish whether the processing described in this 41 , 3'" paragraph of sentence refers to the GMPE estimates or the simulation estimates. section. 2"d sentence Also clarify that the phrase "extent of the rupture plane" means extent of the surface projection of the rupture plane. 896. Section J.5.2, page J-Please either provide the functional form used or a reference to the 41 , 3'" paragraph of report section or publication where ii is provided. section, 3'" sentence 897. Section J.5.2, Page J-Instead of stating that the comparisons are similar, please include 41, 3rd Paragraph of the comparisons with CB14 and CY14 on Figure J.5.2-2 to show the Section, Last robustness of the NGA-West2 GMPE HW terms. Sentence 898. Section J.5.2, Page J-The SDSU simulations do not show a HW effect at M5.5 and M6.0. 41, 4th Paragraph of This would imply that there is some uncertainty in whether there is a Section, 2nd HW effect at small magnitudes. Please discuss how this uncertainty Sentence is factored into the HW model or reference where in the report such a discussion is provided. 899. Section J.5.2.3, Page Instead of stating that the results are similar. please include the J-42, 1st Paragraph, results from CB14 to show that the results are similar. 2nd Sentence 900. Section J.5.2, page J-The statement that the distance taper is small is ambiguous and 42, 5'" paragraph of confusing. It appears, in fact, that the distance tapering factor is near section (2"" on page), unity, not near zero. Please clarify. 2** to last sentence 901. Section J.5 2 3. Page Please also clarify that the development of the HW term for the GMC J-42, 3rd Paragraph, model is given in Appendix K. Last Sentence 902. Section J.5.2, page J-Please reconsider the categorical statement made here that the M 42, 6" paragraph of taper of the NGA-West2 GMPEs is too severe. There are several section (3'" on page). such GMPEs Do you mean to refer to all of them. to all that use 2"" sentence Rrup as the distance predictor, or to just ASK14 and CB14? Why would CY 14 be judged as too severely tapered, given the results in Figure J.5.2-4? Please clarify. 903. Figure J.5.2-2, Page Please expand this figure caption to better describe the plots that J-44 are shown in the figure. 904. Figure J.5.2-3. Page Please indicate that the colors refer to the plus symbols shown on J-44 this and similar plots in the appendix. 905. Section J.6.1, page J-The language used here could imply that 1D models are not yet fully 47, 1*1 paragraph of implemented. Please clarify by revising this line. section. line 1 906. Section J.6 t, Page J-Stochastic simulation methods often employ a set of site-47, 1st Paragraph, 4th amplification factors that are developed from a 1 D velocity and Sentence density crustal structure. typically using the Quarter-Wavelength Method. Please clarify whether or not that is the case with the versions of EXSIM, G&P and SDSU that are available on the BBP, all of which use a stochastic method (though only for the computation of ground motion at frequencies above 1 Hz in the case of SDSU and G&P). If it is, please indicate what crustal structure is used and how similar it is to the velocity models described in this section. 907. Section J.6.1, Page J-Please indicate the referenced features on the velocity profiles 47, 2nd Paragraph, shown in Figure J.6.1-1. 1st and 2nd Numbered Items 908. Section J.6.1, page J-Please indicate whether the recording at PKO was affected by any 47, 3'" paragraph of significant. known 30 wave propagation effects section. line 2 909. Section J.6 t, Page J-Please provide units for the values 286, 93, and 62. 47, 3rd Paragraph, 3rd Line 910. Section J.6 t, page J-The cited figure shows synthetic ground motion, not velocity models, 4 7, 3'" paragraph of so "GIL7 velocity model" should read "synthetics calculated with the section, line 7 1D GIL? velocity model" 911. Section J.6.1, page J-Please provide a reference (either to a publication or to a report 47, 3'" paragraph of section) supporting the asserted appropriateness of the GIL 7 velocity section. line 8 model for the central coast ranges. 912. Section J.6.1, Page J-Please define the term "PL type wave" the first time it is used. or cite 48, 1st Paragraph on a reference where the term is defined. page, 2nd Sentence 913. Section J.6 t, page J-This paragraph (and to some extent the preceding one as well) 48, 2,." paragraph on seems rather awkward and its purpose unclear. The discussion page appears to be treating GIL7-based synthetics as targets for the BBP Norcal-based simulations to match. giving the GIL7-based synthetics similar status to that of the observed waveforms. Why would not all of the models deserve comparison with the observations on an equal footing? Please consider whether it would be less confusing. and more to the point. to simply state that, on balance. simulated waveforms based on the BBP Norcal profile agree with the key features of the observed waveforms at least as well as those based on alternative available 1 D models. 914. Section J.61, Page J-Please avoid 1he use of 1he subjective term very good agreement" 48, 2nd Paragraph, and instead provide a quantitative measure of the agreement and 4th Line why that measure of agreement is acceptable. For example. it appears from Figure J.6.1-3 that the synthetic seismogram amplitudes are as much as a factor of 2 higher than the observations. 915. Section J.61, page J-The clause beginning with "although" confuses the issue, making it 48, 3'" paragraph on harder to understand the point being made. The use of the 1 D model page, 1" sentence is either justified by the tests cited or it is not The fact that there could be an even better option for future use is interesting and worth mentioning as a final comment, but it does not address the question of whether the current use of the 1 D models is justified. Please rewrite this sentence to summarize the Tl Team evaluation of the model actually being applied. Ideas (like 3D modeling) for future improvement may be offered, but in a way that makes it clear that the evaluation is not contingent on those improvements. 916. Section J.6.2, page J-Please provide a specific reference to the discussion or presentation 50, 1" paragraph of where the stated "remark" from Workshop 2 can be found, and section, line 1 indicate the period range implied by long-period" in this context. 917. Section J.6.2, Page J-Please clarify if the comparison is between simulated ground 50, 1st Paragraph, motions or between simulated and observed ground motions. 2nd Sentence 918. Section J.6.2, page J-The line described parenthetically as red appears as a black line in 50, 1" paragraph of Figure J.6.2-1. Please correct this description so that the text and section, line 7 figure are consistent. 919. Section J.6.2, page J-Please clarify that the comparison is between simulated ground 51, 3'" paragraph of motion and synthetic slip models used to compute those ground section (2"" on page) motions, if that is the case. If that is not the correct interpretation, please explain. 920. Section J.6.2, page J-51 , 3'" paragraph of Please explain what the word "maximum" refers to. section (2"' on page). Line 2 921. Section J.6.2, page J-This paragraph and some of the subsequent discussion is difficult to 51, 4" paragraph of follow. Please consider prefacing it with some clear statement of the section on page) purpose of the analysis, and following it with a clear summary statement. For example, if the purpose is to assess (using numerical simulations} whether near-fault. long-period ground motion amplitudes mirror the empirically-observed high variability of static slip values, it would help if that were stated explicitly. If the conclusion is that ground motions do not mirror that high variability, because they are better correlated with broader spatial averages of slip (which are less variable than point values} than they are with nearest-point slip values, it would be useful to summarize that conclusion in explicit terms. 922. Section J.6.2, page J-Please consider whether the intended meaning of this line would be 51, 4'" paragraph of clearer if the phrase "from nearby shallow regions of the fault" were section (3'" on page), restated as "from slip on shallow portions of the fault that are nearby, line 3 but not necessarily nearest. to the site." or some similar phrase that highlights the essential idea that the nearest point on the fault does not necessarily dominate the ground motion amplitude. 923. Section J.6.2, Page J-Please explain the meaning of the term "radiation sensitivity" and 51, 3rd Paragraph on define the terms "FP" and "FN" the first time they are used. page, 7th Line 924. Section J.6.2, Page J-Please clarify that the "given site" is the location of LCN. 51, 3rd Paragraph on page, Last 2 Lines 925. Section J.6.2, page J-This paragraph is difficult to parse and its purpose is not very clear. 51, 5" paragraph of Please rewrite to make that purpose clearer, and also please state section (4'h on page). what is meant by the phrase "pseudo station." 926. Section J.6.2, page J-Please include plots of variation of static displacement, peak FP and 51, 7 paragraph of FN displacement, and SD with the nearest surface slip. section (6"' on page). Line 1 927. Section J.6.2, Page J-Please clarify what "correlations" are being referred to in this 51, 6th Paragraph on statement. page, 3rd Line 928. Section J.6.2, Page J-Please avoid the use of the subjective statement "quite good" and 51, 6th Paragraph on page, 51" line replace it with a quantitative measure of the goodness. 929. Section J.6.2, page J-This sentence is ambiguous. One possible interpretation is that the 51 , 7'" paragraph of static displacement and FP peak displacement correlate better with section (6'h on page). local fault slip than does the FN peak displacement. An alternative 3'" sentence interpretation is to replace "than does" with than with". Please make changes to resolve this ambiguity. 930. Section J.6.2, page J-There is a reference here to "local fault slip." Please distinguish, 51 , 7 paragraph of here and elsewhere in this section, between point-wise (or nearest-section (6:" on page), point) values of local fault slip versus localized averages. The last line on page distinction is important because there is no real question that some sort of local average is going to correlate with low-frequency ground motion. The point of the section appears to be to indicate just how localized that control is. and therefore how much variability it introduces. 931. Section J.6.2, Page J-Please clarify what the "geometric mean" is taken with respect to 60, 1st Paragraph on page. 1st Line 932. Section J.6.2, Page J-Please delete the subjective word "well". 60, 1st Paragraph on page. 4th Line 933. Section J.6.2, Page J-Please complete the phrase "and that the range of the simulated 60, 1st Paragraph on motions". page, Last Line 934. Section J.6.2, page J-Please resolve the ambiguity of the phrase "1 Os of source 60, s** paragraph of realizations," which can be read as "tO's of source realizations" or section (t*1 on page). "10 seconds of source realizations." last line on page 935. Section J.6.2, Page J-Please explain why the capture of the variability along the fault by 61, 2nd Paragraph, the 50 realizations is expected. Last Sentence 936. Section J.7, page J-Please ensure that all of the references that are cited are in the list 61 & J-62 of references and that all of the references are complete with up-to-date information. For example, please update reference items 2, 8, 10 & t3 with complete publication information, and the missing references for Goulet et al. (20t4} and Dreger et al. (2014) that were cited at the end of Section J.1.1. 937. Figure J.2.2-2, page Please add to the caption that "Shoreline" and "San Luis Bay" label J-11 the rupture segments modeled in the simulation, and indicate their relationships to the Shoreline Fault and San Luis Bay Fault, respectively (e.g .. that they are simplified representations inspired by the Hosgri-Shoreline splay scenario?). 938. Figure J.4.2-2. Page Please add a label to the y-axis and indicate in the figure caption J-26 that this figure is for complex rupture Scenario 1. This request also applies to Figures J.4 2-5. J.4.3-2, and J 4 3-5. 939. Figure J.4.2-3, page The gray lines in this plot are not visible. and the meanings of the J-28 colors are not indicated (the latter also applies to Figure J.4.2-6, J.4.3-3, and J.4.3-6). Please correct. 940. Figure J.4.2-6, page The gray lines in this plot are not visible. and meanings of the colors J-32 are not explained. Please correct. 941. Figure J.5.2-3 & These figures use a different color scheme for the 3 simulations than Figure J.5.2-4, pages do earlier figures, which is confusing. Please use the same color J-45 & J-46 scheme for all figures for clarity. 942. Figure J.4.3-2, page Please label the plot axes. J-35: Figure J.4.3-5, Page J-39; and Figure J.6.1-1. page J-48 943. Figures J.6.1-2 and Please indicate the recording station in the caption. J.6.1-3 944. Figures J.6 2-5 Please explain the use of the factor Y:i, and why it is absent in Figures J.6 2-6 and J.6 2-7. Also please define the symbols and lines in the plot and reword the caption lo be more meaningful in this and similar figures in the appendix. APPENDIX K Hanging Wall Model 945. General There are many parameters, terms, and acronyms used throughout the appendix without first being defined. As a reiteration of previous comments on various chapters and appendices in this report. please ensure that all of the parameters, terms, and acronyms used in this appendix are defined in a list prior to their use. Otherwise, they will need to be defined the first time they are used in each chapter and appendix. 946. General All of the figure captions are short and cryptic. Please expand the figure captions to comple1ely describe all of 1he curves shown on the plot and the values of any variables that were used to plot them. 947. Sec1ion Kt. Page K-Please explain the meaning of the term "HW facto( the first time it is 1, 1st Paragraph of used (e.g., indicate how is it calculated from each GMPE). Please Section, 1st Line also indicate who derived the HW fac1or model in place of the statement "The HW fac1or model was derived". 948. Page K-1. First Please include a brief summary of the ranges of magnitude and Ztor Paragraph and site locations (Rx) for which HW effects are of importance to the GMC model. 949. Section K.1, Page K-The dip of the rupture plane is a fifth aspect of the ASK14 and CB14 1. 1st Paragraph of HW terms 1hat has been overlooked. Please mention 1he dip of the Sec1ion, 2nd Line rupture plane as an additional aspec1of1he ASK14 and CB14 HW terms. 950. Sec1ion Kt. page K-Please replace "rupture place" with "rupture plane," or, perhaps 1, 1" paragraph, line 3 more precisely, wi1h "rupture surface." 951. Sec1ion Kt. Page K-Please define the term taper," as it applies in this context, the first 1. 1st Paragraph of time it is used. Section, 5th Line 952. Sec1ion Kt. Page K-Please indicate which of the five aspects of 1he HW 1erms of ASK14 1. 1st Paragraph of and CB14 are also present in 1he CY14 HW term before describing Sec1ion, 7th Line the differences in this latter term. 953. Section K.1, Page K-Please insert the missing comma after 1he word "magnitude" at the 1, 1" Paragraph, Line end of line 7. 7 954. Sec1ion K. 1.1, Page Please avoid the use of the subjective term "significant" and instead K-1, 1st Paragraph of provide a quantitative metric to describe these differences. Please Section, 6th Sentence also summarize the observed differences among the HW terms of the NGA-West2 GMPEs. 955. Sec1ion K.1.1, Page Please indicate if the HW factors given by Eq. (K-1) are arithmetic or K-1. Eq. (K-t) logarithmic and exercise care when referring to this factor elsewhere throughout the appendix by indicating if it is the multiplicative factor or the log factor that is being referenced. 956. Section K.1.1, Page Please justify the assumption that the HW effec1 is largely geometric K-2, 1st Paragraph on and show why. based on this assumption. that the surface projection page. 2nd Sentence of the rupture plane is directly related to the cosine of the dip. 957. Section K. 1. t. page Please add a comment noting that the formulation alluded to was K-2, 1" paragraph of section (1"1 on page), 3'" sentence on page introduced to fit numerical simulations, if that is the case. 958. Section K 1.1, Page Please briefly describe the HW study and model developed by K-2. 1st Paragraph. Donahue and Abrahamson (2014). 5th Line 959. Section K 1.1, page Please clarify the purpose of the expression "with the effect based K-2, 1" paragraph of on the GMPE." It seems to be covered already by the text in the section ( 1"' on page), beginning of this sentence. Line 7 960. Section K.1.1, page Please justify the Tl Team's decision to neglect HW effects at K-2. 1st paragraph of periods longer than 3 seconds, in light of the interpretation of Chang section ( 1*1 on page). et al. (2004, BSSA, vol 94, p. 2186) that there are large HW effects 2"* to last sentence at long period (T = 2s and 4s) for the 1999 Chi Chi earthquake. This may entail showing plots of long-period (T>3s) residuals for the ChiChi earthquake computed with respect to the candidate GMPEs. 961. Section K 1. 1. Page Please define the meaning of "central model (e.g., is it the median K-2. 1st Paragraph on or mean HW factor. which depends on whether the model is on the page. 12th Line factor itself or the log of the factor). 962. Section K.1.1, page Please check whether this line should say '"K-1 through K-4." and K-2, 1" paragraph of section (1"1 on page). correct if appropriate. last line 963. Section K.1.1, Page Please define the term "base model" the first time it is used. K-2, 2nd Paragraph, 1st Line 964. Section K 1. 1. Page Please further explain (here or preferably in Chapter 6) the necessity K-2, Second for equal-probability sampling of the HW factor models, in lieu of Paragraph of section other variance-preserving sampling schemes (un-equally weighted) (and 2°0 on page) such as those widely used to represent the epistemic uncertainty of other PSHA inputs. 965. Section K 1.1, Page Please clarify whether it is the arithmetic HW factor or the log HW K-2. 2nd Paragraph, factor that is assumed to be normally distributed. 3rd Line 966. Section K.1.1, Page Please explain the meaning of '"fitted model K-2. 2nd Paragraph, 5th Line 967. Section K 1. 1. page Please define the term "epsilon" the first time it is used. K-2, 2"" paragraph of section and page, line 7 968. Section K 1.1, Page Please explain how the "probability weighted mean epsilons" were K-2. 2nd Paragraph, calculated. 7th Line 969. Section K. 1.1, Page Please explain why "equally weighted factors were used when they K-2. 2nd Paragraph, were derived from different probability ranges of a normal 12th Line distribution. 970. Section K 1.1, page Please check whether this sentence should say "K-1 through K-4," K-2. 2"" paragraph of and correct if necessary. section (2"c on page). 2"' to last sentence 971. Section K. 1.1, Page Please avoid the use of the subjective term "good" and provide a K-2, 2nd Paragraph, quantitative metric for describing the goodness of the observed 14th Line comparison. This applies to this instance and several other instances throughout the appendix where "good" is used to describe the goodness of a comparison. 972. Section K. 1.1, Page Please explain why it is acceptable for some of the GMPE HW K-2, 2nd Paragraph, factors to fall outside the bounds of the five proposed HW models. 14th Line 973. Section K1.2. Page Please summarize the analysis from Appendix J to the extent K-2 necessary to form a readable and understandable review of the Tl Team's treatment of the magnitude taper issue. If. in that treatment. the magnitude-dependence carried implicitly by Eq K-1 is deemed reasonable based on the good agreement with simulated HW effects at M 5 5. please state this explicitly. 974. Section K 1.2. Page Other reasons why the ASK14 and CB14 HW models applied a K-2, 1st Paragraph of magnitude taper to make the HW factor go to zero at M5.5 was the Section, 2nd Line lack of any empirical data or numerical simulations to support a HW effect at smaller magnitudes. Please include these reasons in support the NGA-West2 developers "judgment" that is stated as the reason for the taper. 975. Section K. 1.2, page Please give a specific magnitude range for the phrase "moderate K-2, 1" paragraph, magnitudes". Line 3 976. Section K 1.2. Page The ground motion simulations described in Appendix J showed that K-2, 1st Paragraph of one of the three simulation models (SDSU) did not predict strong HW Section, 2nd effects at small magnitudes. except at relatively small depths (e.g., Sentence Ztor = 2.5 km) or relatively small dips (e.g .. dip= 30 degrees). Please indicate how this uncertainty is incorporated in the HW factor model presented in this appendix. 977. Section K.1.3, page Please indicate that the site angles of 90 and 0 degrees mentioned K-3, 3" and 4'" in these sentences are measured relative to fault strike. sentences of section 978. Section K 1.3. page Please explain how the assertion that CB14 and CY14 "allow for a K-3, lines 4-6 on page smoother transition as a function of location around the rupture is consistent with the fact that (according to Figure K-5) CB14 has a step as Rjb approaches zero along the strike direction This step behavior actually appears to be a sharper transition than that of any of the other HW models in Figure K-5, and would seem inconsistent with this assertion 979. Section K.1.3, Page Please avoid the use of the subjective term "well." which in this case K-3. 1st Paragraph. can be deleted without impacting the statement 6th Line 980. Section K.1.3, Page Please indicate that the proposed Rjb taper model given by Eq. (K-K-3, 1st Paragraph, 2) is shown in Figure K-5. Eq. (K-2) 981. Section K.1.4, Page Please avoid the use of the subjective term significant" and instead K-3. t st Paragraph of provide a quantitative metric to describe the observed differences in Section, 3rd Line the trends. 982. Section K. 1.4, Page Please indicate that the proposed Ztor taper model given by Eq. (K-K-3, 1st Paragraph of 3) is shown in Figure K-6 Please also show the equation for the Section, Eq. (K-3) complete HW factor model that combines all three equations for completeness (also note whether the complete model is the arithmetic or log value of the HW factor. 983. Section K.2, page K-Please provide a specific reference to the section(s) of Appendix J 3. 1"' paragraph of where the hanging wall analysis is presented. section, 1" sentence 984. Section K.2, Page K-Please provide and discuss the development of the equation that 3. 1st Paragraph of was used to define the footwall simulations. Section, 3rd Line 985. Section K.2, Page K-Please clarify who did the simulations described as "were 3. 1st Paragraph of simulated". Section, 5th Sentence 986. Section K.2, Page K-Please provide similar plots to those in Figure (K-11) for a range of 4, 1st Paragraph, 2nd magnitudes. dips, and depths to fully document the comparison with Sentence the simulations, or revise Figures (K-1) to (K-10) to show all five HW factor models instead of only the central model. 987. Section K.2, Page K-4 Please ensure that all of the references cited in the text are included in the list of references and that all of the references provide a complete description of the publication (e.g., volume and page numbers). 988. Table K-t. Page K-4 Please include all five of the C1 values that represent the five HW factor models in Table K-1. 989. Table K-t. Page K-4 The "Central" and "Range of Models" shown in this figure have not been discussed the first time this figure is referenced in the text. Please provide an explanation of these curves as well as an explanation that the curves and GMPE estimates are for Ztor = 0 in the figure caption of this figure and in Figures (K-2) through (K-4). 990. Figures K-1. K-2, K-3, Please make changes to the legend to reflect that the dashed lines and K-4 do not show the "range .. of the models, but rather are the five individual models used to approximate the distribution of the modeled HW factors. 991. Figure K-5. Page K-Please check the CB14 HW factor for the increasing Ry curve, which 10 for Rx = O should have a positive HW factor that decays with distance (i.e .. it is only for Rx< O that CB14 predicts no HW effects). 992. Figures K-5 and K-6 Please change "rx" in the figure legend to "Rx" to be consistent with the main text 993. Figure K-7 Please explain in the caption the meaning of the solid black curve in each plot and provide references to the three simulation models that are defined by their acronyms in this and similar figures in the appendix. Please also indicate that the SWUS HW term (called HW factor model in the text) that is plotted in this and all similar figures as the red line is the central model. APPENDIX 0 Comparison of Hazard: Original GMPEs versus Common Functional Forms 994. General Although the plots shown in this appendix show that the range of hazard is captured, ii would be useful to show a comparison of the hazard curves from the GMPEs with the 5th, 50th, and 95th percentile hazard curves from the common-form models in order to also show that the body and not just the range of the hazard is also captured. Please provide such plots in addition to those that are already shown for the DCPP and PVNGS models. 995. Section 0. 1, page 0-The reference to a "simplified" seismic source model is confusing. 1, 2"" of This sentence refers to it as the DCPP SSC model used in Chapter section. 2" sentence 14, and the First Paragraph on Page 14-1 states that "the previously published Seismic Source Characterization (SSC) models for the two sites were used ... without reference to any simplification. Please review and revise the entire paragraph as needed to clarify. 996. Section 0.1. page 0-Without a comma after the words "closest sources", this sentence is 1. 2"d of (almost) ambiguous as written It could mean that the source model section. 2" sentence comprises the closest sources. inasmuch as those are the significant contributors. But it could easily be misread to mean that, among all sources that are significant contributors, the model singles out only the closest ones If the former interpretation is intended. please clarify that by means of a comma. 997. Section 0.2. General Except for the addition of the hazard curve from GK14, Section 0.2 appears to provide the same information as provided in Section 8.4.3 (and Figures 8 4-17 and 8.4-18). Please clarify what is new in Section 0.2. compared to Section 8.4.3. 998. Section 0.2, Page 0-Please see comments given in other chapters and appendices 1, 1st Paragraph of regarding suggested revisions to the bullet list of references to these Section, 3rd Line eight GMPEs. 999. Section 0.2. Page 0-Please provide the reference to sections of the report where the 2. 2"d paragraph on common-form models are described. page (1" sentence after the bulleted list) 1000. Section 0.2, Page 0-Please indicate who calculated the common-form model hazard 2, 3rd Paragraph, 1st curves (i.e., the Tl Team, a hazard analyst, etc.) and the hazard Line code that was used. 1001. Section 0.2. Page 0-Please describe in more detail the modification that was made to the 2. 3rd Paragraph, 5th ASK14 model. Line 1002. Section 0.2, page 0-Similar to the earlier comment, a comma after the words "hanging-2, 2"" paragraph of wall model .. would help insure a correct interpretation of the section, line 6 sentence. 1003. Section 0.2. page 0-Please consider adding the qualifier that the mean hazard from the 2. 3rd of common-form models plots near the up per limit of the GMPE range section. 3' sentence at the relevant hazard levels (e.g., to* and less) and that this does not seem to be so clearly the case at higher hazard levels. t004. Figure 0.2-1a, Page In this and all similar figures in this appendix. please use the same 0-3 acronyms for the models listed in the legend that are used elsewhere throughout the report and appendices (e.g., use "ASK14" instead of "ASK") 1005. Section 0.3. General Except for showing hazard curves from Model A and Model B together on the same plot, Section 0.3 appears to provide the same information as provided in Section 9.1.1.3 (and Figures 9.1-19 and 9. t-20). Please clarify what is new in Section 0.3. compared to Section 9.1.1.3. t006. Section 0.3, Page 0-Please see comments given in other chapters and appendices 7. 2nd Paragraph regarding suggested revisions to the bullet list of references to these six GMPEs. 1007. Section 0.3. Page 0-Please avoid the use of the subjective term "significant" and instead 7. 3rd Paragraph. 9th provide a quantitative metric to describe the contribution to the Line hazard of the distant seismic sources. t008. Section 0.3, page 0-Please add a comma after the word "strong." to signal that the 8, last line subsequent "as" is being used as a conjunction to introduce a clause (not to express similarity). t009. Figure 0.2-1a, Page It is difficult to tell the difference between the two blue dashed 0-9 curves in this plot. Please use a different color and/or symbol so that these two curves can be more easily distinguished in this and similar figures in this appendix. t010. Section 0.4, Page 0-Please ensure that all of the references cited in the text are included 13 in the list of references and that all of the references provide a complete description of the publication (e.g., volume and page numbers). APPENDIX Q Host Kappa 1011. General comment A list of references is missing from the appendix. Please include a complete list of references in a separate section of the appendix. 1012. General comment There are a lot of parameters. terms, and acronyms used throughout the appendix without first being defined. As a reiteration of previous comments on various chapters and appendices in this report. please ensure that all of the parameters. terms. and acronyms used in this appendix are defined in a list prior to their use. Otherwise, they will need to be defined the first time they are used in each chapter and appendix. 1013. General comment Please check, in this appendix and throughout the report, to ensure that geographical terminology and acronyms are consistent with usage in the DCPP and PVNGS SSC projects. One example worth checking is whether "Sonoran Basin and Range" is the name for the PVNGS host region (please confirm that it is not southern Basin and Range" in the PVNGS SSC, or if it is, make changes to ensure consistency). 1014. General comment Please make the notation consistent throughout the chapter (and consistent with the rest of the report). For example, the decay exponent is sometimes spelled out in roman letters as "kappa". sometimes given by the Greek letter K, and k1 and k1 seem to be used interchangeably (and k(O) is used in lieu of Ko, even though the latter seems to be advocated by Ktenidou et al.. 2014 ). In the process of clarifying, please also give consideration to the merits of following as strictly as possible the published taxonomy of Ktenidou et al. (2014). 1015. General comment Please define kappa and provide the foundational references that established the empirical basis for this concept. 1016. Page Q-1 , first The term "Host kappa" is jargon that only insiders will understand. paragraph particularly since "host" is used in multiple, seemingly quite different senses in the report (e.g., in Chapter 14, "host" refers to the Sonora Basin and Range region in which PVNGS is situated}. Please begin by explaining precisely what is meant by the term in the current chapter and how the host kappa estimates are then used in the GMC model. Please also cross-reference those places in the report where the resulting kappa estimates are used 1017. Section Q.1. Page Q-Please revise the Akka r et a I., Bindi et al., and Zhao references to 1. 1st Paragraph of show the correct publication dates and acronyms (as used Section elsewhere throughout the report and appendices) and to include the published errata for the first two references. Please also ensure that the correct acronyms for the GMPEs that are used throughout the report and appendices are used here and elsewhere throughout the appendix. including in figure legends and figure captions. 1018. Section Q.1. page Q-Please provide the meaning of IRVT upon its first occurrence, and 1, paragraph of provide a reference to the method (not just to the computer section, 1" sentence program). 1019. Section Q.1. page Q-Please rewrite the sentence with parallel construction to improve 1, 3"' paragraph of clarity (e.g., "for spectra with higher host kappa than for those with section, last sentence lower host kappa." if that is the intended meaning). 1020. Section Q.2, Page Q-Please provide a reference for the IRVT approach that is used. (e.g .. 1, 1st Paragraph of if it is that published by Al Atik et al., 2013, please indicate that). Section, 1st Line 1021. Section Q.2, page Q-This comment refers to the phrase "while also limiting the Q 1, 1" paragraph of attenuation effects" The kappa effect is itself most likely. at least in section. Line 4 part, a Q effect (which would be better described as an "anelastic effect"), but just one that is so localized that it is more practical to treat it as a separate site-associated parameter. To avoid feeding confusion on this point. please state more precisely what is meant by this phrase. If the Tl Team chose close stations in order to isolate that part of the attenuation that persists in the limit of short propagation paths and is therefore suited to modeling as a site-associated attenuation factor exp(-pi"kappa*n. please indicate that 1022. Section Q.2, Page Q-Because of its common use in stochastic simulation. please also 2, 2nd Paragraph on provide and plot the Vs profile for the WUS crustal model of Boore page. 1st Sentence and Joyner ( 1997) in Figure Q-1 . Likewise, please plot the related site-amplification factors for the WUS crustal model of Boore and Joyner (1997} in Figure (Q-2). 1023. Section Q.2. Page Q-Please describe and reference the "OWL program" that was used to 2. 2nd Paragraph. 6th obtain the Vs-density relationships and summarize those Line relationships for completeness. 1024. Section Q.2. Page Q-Please explain what an angle of incidence of zero means and why it 2. 2nd Paragraph, 5th was assumed to be zero and what impact this assumption has on the Sen1ence final results 1025. Sec1ion Q.2, page Q-Please consider referring to "the nine selected scenarios" 1o clarify 3, 3"' paragraph of that the reference is to the selections made in the earlier paragraph section ( 1*1 on page). for 1he reasons stated there. The current language given by the 1 *1 sentence phrase the nine scenarios considered," could be misunders1ood as part of an evaluation process (i.e., that some were considered and rejected, for example). 1026. Section Q.2. page Q-This sentence asserts that the kappa derived using the IRVT 3. 3rd of approach (kt} is not equal 1o kappa(O). This categorical statement section (16 on page). could imply that k 1 is in principle not able to capture kappa(O). Is that line 8 &9 really the meaning intended? If so, please explain, and reconcile this asser1ion with 1he fact that Ktenidou et al (2014) classify the IRVT-derived method as a k(O) estimator in their Table 1. Otherwise. please reword these lines. 1027. Section Q.2. page Q-As noted in an earlier comment, the reference here to "anelastic 3, 3"' paragraph of attenuation" implies that the kappa decay factor is not a section (1"' on page), consequence of anelastic attenuation. whereas the scientific 2"' to last sentence consensus is that it is (at least in part). Please reword this sentence to express the intended meaning more precisely. 1028. Section Q.2. page Q-Please explain the distinction being made here between k(O) and 3. 3rd paragraph (1*1 k,;,., and justify the assumption that there is no source contribution to on page), last line kappa. 1029. Section Q.2, page Q-Please explain what is mean1 by "bes1 picks." On what criteria was 3. 41to paragraph of the selection made? section (2"" on page). Line 5 1030. Section Q.2. Page Q-Because this appendix is intended to present the details of the host 3. 2nd Paragraph on kappa calculations. please provide plots for all nine scenarios for all page. 5th Sentence seven GMPEs for completeness. 1031. Section Q.2, Page Q-For completeness. please provide the standard deviations of the 3, 2nd Paragraph, 6th host kappa values shown in Table Q-1 that account for uncertainly in Sentence the f1 and f2 picks, the nine different scenarios, and the two different crustal models 1032. Section Q.2, page Q-The phrase "best es1imate seems to be used in two different senses 3, 4'" paragraph of in its two occurrences in this sentence. Please clarify. Also note that section (2"c on page). there appears to be a missing word or words after "GMPE." last sentence From: Steven Day <sday@mail.sdsu.edu>

Subject:

informal comments Date: February 9, 2015 at 4:43:37 PM PST To: Norm Abrahamson <abrahamson@berkeley.edu>, Carola DiAlessandro <carola dialessandro@geopentech.com> Cc: Steven Day <sday@mail.sdsu.edu>, Thomas Rockwell <trockwell@mail.sdsu.edu>, Brian Chiou <brian chiou@comcast.net>, Kenneth Campbell <ken.w.campbell@comcast.net> Attachments: SWUSFinal Rpt CommentsTKR.docx (48 KB); SWUS Final Rpt suggested -1.docx (56 KB); SWUS_Comments_Rev1_smd.docx (71 KB) Carola and Norm, Thanks for a productive meeting this morning. And thanks, Carola, for agreeing to assist us by setting up the PPRP conference call next week. That is a big help. As promised, here are some unedited preliminary comments from Tom and myself. These are not to be understood as formal comments from the PPRP, as they have not been discussed, reconciled, edited or approved by the full panel. However, we are happy to provide them informally, acting as individuals, for your consideration. Tom's comments are complete for the main sections (and he provides a second file with what are more purely editorial comments). Mine are complete for Chapters 3-15, and I also include several of the appendices. Steve February 20, 2015 Dr. Carola Di J\ lessandro SWUS Project Manager GeoPentech, Inc. 525 N. Cabrillo Park Drive, Suite 280 Santa Ana, CA 9270 I

Subject:

Participatory Peer Review Panel Letter No. 3: Draft Rev. I Report, Southwest United States Ground Motion Characterization Level 3 SSHAC Project

Dear Dr. Di Alessandro:

This letter provides comments and recommendations of the Participatory Peer Review Panel (PPRP) for the SWUS Project Report, Draft Rev. I. Here we address Chapters 1 through 16. Our Letter No. I (dated December 13, 2014) already provided comments on Chapters 7, I 0, 11, 12, and 13, and Appendices L, M, N, and R of Rev.O. Our Letter No. 2 addressed Chapters 6, 8, 9, and 14, and Appendices H, I, J, K, 0, and Q of Rev.0. We have not yet had the opportunity to thoroughly review all of the revisions made to the appendices for Draft Rev. I. The review comments are tabulated in two parts. Tier I comments are those that the PPRP considers of the highest relevance to our assessment of the documentation. Those are listed separately at the beginning of the Comment Table, identified by both chapter and line number. Tier 2 comments are additional comments tabulated by chapter and identified by line number (or table or figure number where more appropriate). Each comment in the review is assigned a unique number for reference. Comments transmitted previously with Letter No. I were numbered 1-320, those with letter No. 2 were numbered 321-1032, and the numbering of comments transmitted with the current letter start with l 033. The table includes an additional column in which the responses of the TI Team may be recorded. The review is not intended to be editorial. but we do call attention to stylistic or grammatical concerns in instances where they substantially affect clarity or may introduce ambiguities. The Draft Rev. I report covers the full scope of the evaluation and integration efforts of the Tl Team. These review comments from the PPRP are intended to help the TI Team improve the quality and clarity of its documentation of the technical basis and justifications for the models and weights used in the final GMC logic trees. Sincerely. Steven M. Day Chair, PPRP Brian Chiou Member, PPRP Kenneth W. Campbell Member, PPRP -1 :'.. 1 i. .1 .* s".> -// /-* .. *'" Thomas K. Rockwell Member, PPRP Comment Response Table Comment Location in Text PPRP Comment Summary of Revisions to Report Number Tier 1 Comments 1033. Directivity model: The Tl team has not provided sufficient information detailing their General evaluation of the directivity model. It is necessary that the explanation of the Tl Team's evaluation include sufficient detail to clarify (1) what the model is. (2) what its limitations are, and (3) what analysis was done to demonstrate that it is justifiable (in light of any model limitations) to use it for the purpose it is being used for here. Please provide an explanation meetina those criteria in the reoort. 1034. Directivity model: There are two major assumptions that are made in applying the CY14 Chapter 6, Lines 914-centered directivity model to the GMPEs used in the DCPP GMC model: 922 (1) that the large-magnitude distribution is similar amongst the NGA-West2 GMPEs so that similar directivity effects can be expected. and (2) that the centered CY14 model can be applied to the NGA-West2 GMPEs to model these effects. These are both potentially important assumptions. Please provide justification for these assumptions or indicate that the imoact of these assumotions is not critical to the hazard. 1035. Directivity model: Please further justify the zero weight given to the directivity adjustment Chapter 9, Lines branch by providing evaluations in support of the claim that directivity 317-320 effects are adequately captured by the standard deviation from the GMPEs Also. if this claim is justifiable. please explain why the same justification was not applied to DCPP to assign a zero weight to its directivitv branch. 1036. Evaluation of Please revise this passage to emphasize that these simplified hazard Common-form suite: comparisons are not the primary basis for evaluating the common-form Chapter 8, Lines 305-suite of representative models (which, though it should be hazard 308 informed, should not be hazard calibrated, i.e., it is required to cover the CBR of the TOI of ground motion, not hazard). II appears that the simplified hazard comparisons are actually being used as a final check to ensure that occasional small excursions of the candidate GMPE estimates (with added epistemic uncertainty} do no carry unexpectedly high leverage with respect to hazard. If that is the case, please reframe the discussion to clarify that. The additional discussion should emphasize this point by summarizing the non-hazard-based justification for accepting a suite of common-form models that does not fully envelop the predictions of the candidate GMPEs (all of which were considered to be credible--i e .. they passed the test by the Tl Team of being technically defensible interoretation s ). 1037. Evaluation of Although it is reasonable to use the hazard as a guide in determining Common-form suite: whether the representative models produce a wide enough hazard Chapter 9, Lines 301-distribution, it seems appropriate that the distribution of the ground 313 motion models should also be wide enough to encompass the candidate models and their epistemic uncertainty. Please explain that both of these distributions were checked and that the hazard distribution alone is not being used to judge whether the representative suite of models represents the CBR (especially the range) of the ground motion distribution, which should be the intent of a SSHAC Level 3 ground motion studv. 1038. Short-range Please reconcile the statement that the finite-fault simulations all show saturation: Chapter 6, saturation at short distances" with the statement on Line 697 of Lines 40-41 Appendix J (and evidence in Figure J.4.3-1) that "the GMPEs have stronger saturation than the EXSIM model at very close distances." If it is correct that EXSIM has less saturation at short distances. please explain why this should not be interpreted as support for the ld14 model (e.g., is the formulation of EXSIM such that it is not intended by its developers for use at the shortest distances? Or does the Tl Team argue on physical arounds that EXSIM is not reliable at short distances?). 1039. Short-range The 1014 model was deemed unreliable by the Tl Team in the range of saturation: Chapter 6, M <: 7.5 and R::; 3km The description of the Tl Team's justification is Lines 47-61 and based mainly on the interpretation that 1Dt4's predicted median PGA is Figure 6.2.1-2 an outlier (it is higher by about 40% than the predictions of other candidate GMPEs). However, the predicted median at Rs; 3km for T = 2s from the ZL 11 and the ZH06 GMPEs are also much higher than the other GMPEs (by more than 50%), but neither were rejected (Figure 6.2. t-2) Please iustifv the seeminalv inconsistent assessments. 1040. Consistency of Key The parameters FREv and F.,.L defined on these lines do not appear in Equations: Chapter 6, Eq (6.4-1 ). On the other hand.Fin Eq 6.4-1 is not defined. Furthermore. Lines409.4t0 this equation differs from what would seem to be intended to be its equivalent in Appendix C, Part II, Line 33. where FRFv and F*M1 appear. but not F, and an additional coefficient a1o appears that is absent in 6.4-1. Also, coefficient ag is squared in 6.4-1, but not in the Appendix C counterpart. It would be beneficial and less confusing to many readers if the same terminology for predictor variables used in the NGA-West1 and NGA-West2 projects were used throughout the report. For example, please consider replacing "FF<Ev" and FN"L" with "Ff<*/ and F""" (and note, as mentioned above. that these terms are not actually used in Eqs (6.4-t) and (6.4-2) and instead only a single T' indicator variable is used in these equations). Please replace "F" in these equations with the mechanism-specific predictor variables or modify the text accordingly, and in any case make changes to ensure consistency with Appendix C. It is likely that the inclusion of a tenth coefficient in the text that follows refers to the inclusion of two predictor variables to represent the style-of-faulting. If this is the case. and the equations are corrected. then please ignore those comments that refer to the missing tenth coefficient elsewhere in the list of comments. Tier 2 Comments (by chapter) General 1041. NIA Please carefully review the references for completeness and to ensure that all cited references are listed. For example, some of the same references in different chapters are listed slightly differently (i.e .. one might be missing a volume number or page numbers while another miaht notl. t042. NIA The report is written primarily in third person. which implies that the writers of the report, chapter, and/or section performed the work or made the decisions and assumptions that are being described. However, there are no specific authors listed on the report, which is only identified by the publisher. GeoPentech. and a list of participants in the project. Please make it clear who the writers of the report are either on the Title Page (ideally) or in the introduction so that there is clear ownership of the work that is beina described in the third oerson. When the descriotion refers to someone else's work. decision. or assumptions, please make it clear that this is the case. There are also still sporadic uses of the pronouns "we" and "us" throughout the report, which is even more ambiguous. Please consider replacing these pronouns with the person or group that the pronoun refers to (e.g., the Tl Team or a specific Resource Expert) or change the sentence to third person to refer to the identified writers of the reoort. CHAPTER 0-Table of Contents 1043. NIA The Section No. 5 21.1 appears twice. The second one should be 5.2.2.1. 1044. NIA In the title of Section No. 5 5 3. Vs should be 1045. NIA The Section No. 6 4 5 3 appears twice. The first occurrence should be 6.4.5.2. CHAPTER 1-Introduction 1046. Lines 57-58 The description of Vs*o as shear-wave velocity" should be more accurately described as "travel-time-averaged shear-wave velocity. This change also applies to the definition of in the list of terms and acronvms. 1047. Line 63 Please define "kappa." since this is the first time that this term is used in the report. Please also add the definition of kappa to the list of terms and acronyms. which only contains the specific symbols used to characterize the different ways kappa can be estimated and no definition of the generic term kappa itself. 1048. Line 80 Please define sigma," since this is the first time that this term is used in the report. Please also add the definition of sigma to the list of terms and acronyms. which only contains the specific symbols used to characterize the different types of standard deviations and no definition of the generic term siqma itself 1049. Line 109 Please consider replacing the phrase "suites of models" with "representative suite of models here and elsewhere in the report to conform with terminology used in "Atkinson, G.M., Bommer, J.J., and Abrahamson, N.A. (2014). Alternative approaches to modeling epistemic uncertainty in ground motions in probabilistic seismic-hazard analysis, Seismo/oqical Research Letters, Vol. 86. pp 1141-1144." CHAPTER 2-Project Organization 1050. Line 52 The description of the workshops is incomplete and does not list all of the purposes of the workshops. Please qualify the sentence to indicate that this is only one of the purposes of the workshops or expand it to list all of the purposes. 1051. Line 53 Since this is the first time that peer review is mentioned in the report, please introduce the peer review panel and the acronym PPRP. Please also add the definition of PPRP to the list of terms and acronvms 1052. Line 75 The use of the phrase "Appendix A of Appendix A" is awkward. Please consider calling the appendix of an appendix something different in order to avoid confusion Ce.a., "annex"). 1053. Line 81 Please correct the name of the power plant. i.e., "Saint Onofre" should be "San Onofre." 1054. Line 146 Please correct the grammar in this passage, e.g .. "preliminary estimate of the kappa sensitivity ... " 1055. Line 157 The large magnitude earthquakes in California cited here appear to be the same events referred to elsewhere in the report as large earthquakes in California and Mexico (appropriately, since the 2010 El Mayor-Cucapah event is included). Please clarify or correct for con sistencv. 1056. Line 162 Please provide a reference to the PEER report that is mentioned in this sentence. 1057. Lines 167-171 Please provide references for the PEER projects that are referred to in this paragraph. 1058. Line 187 Please reference the report or appendix where the PE&A study can be found. 1059. Line 189 Please consider replacing the word "sensibly" with one that better conveys what the writer intended to mean. 1060. Line 253 Please explain what "anticipated" means in this context. CHAPTER 3-SWUS GMC Work Plan and Key Study Tasks 1061. Line 97 Please confirm that the distance range 30-100 km is correct and should not be "less than 100 km." 1062. Line 152 In Table 3.4-1, "Ken Campbell Consulting" should be "Kenneth W Campbell Consulting." 1063. Line 244 Please clarify that "the second meeting" refers to the January 2014 Special Working Meeting. 1064. Line 340 In Table 3.7-1, "Ken Campbell Consulting" should be "Kenneth W Campbell Consulting." CHAPTER 4-Seismotectonic Setting 1065. Line 160 Please explain the difference between .. layered faults" and "individual faults. 1066. Lines 163-164 These lines refer to two categories. namely .. the California and Mexico faults (referred to as Regions 1 and 2&3 in this Report)," and "other faults (AZ,NM, NV, and Mexico):* Table 4.2-2 has rows for CA Faults" and "AZ, NV, & Mex Faults. Do the rows of the table correspond to the two categories of faults described in the text? If so. please align the terminoloov; if not. olease clarifv. 1067. Lines 172-179 The legends of Figures 4-8a and 4-8b are not well correlated with the text. For example. "NSHMP faults" are noted in the legends but are defined neither there nor in the text. And the text calls attention to the dominance of distant fault sources for low frequency at 10-* AFE, but the figures do not identify the curves associated with distant fault sources. Please reconcile the figure legends and the text. 1068. Line 289 In Figure 4-8a, please explain the meaning of "coarse" and fine" areal sources. 1069. Line 293 In Figure 4-8b, please explain the meaning of "coarse" and "fine" areal sources. 1070. Tables4.1-4, 4.2-1. Please identify the pertinent site (i.e., DCPP or PVNGS) in the title of 4.2-2 each of these tables. 1071. Figure 4-1 The two line colors for the SAF are not well distinguished in the figure. Please consider making improvements to remedy this. 1072. Figure 4-2 Please identify the site (DCPP) in the figure caption. 1073. Figure 4-6 The arrow for the Cerro Prieto fault points to the Imperial fault (CPF is the next bold red line to the SW). Please correct this. CHAPTER Motion Databases and Candidate Models 1074. General Two references for Kishida et al., 2014a and 2014b, appear in the reference list. However, many of the citations in this chapter refer only to Kishida et al. (2014) without distinguishing 2014a from 2014b. Please check and correct this omission. 1075. General The figure numbering scheme seems to be inconsistent in this chapter. For example. Figure 5.2.2-2 is called in Section 5.2.2.1. indicating the convention that only the chapter number and first two section levels prefix the sequence number. But a Figure 5.2.3.4-1 is called in Section 5.2.3.4, so in that case the chapter number and all three section levels prefix the sequence number. There are some other anomalies as well. Please check carefully and ensure that numbering is done consistently th rouahout. 1076. Line 11 Use of the term "proponent models" is confusing. especially given that the report is written in third person with no identified authors. The term is usually reserved for describing a model or method proposed by a Proponent Expert (PE). If this is not the meaning of the term in this context or in similar contexts elsewhere in the report, please consider using another term to describe the models or identify who the proponents are (e.g .. 'Tl Team proponent models") when the term is used. 1077. Line 27 The intended meaning of the sentence is ambiguous. If the in1ent is to say that the Wells earthquake was in the southern Basin and Range. please review for accuracy (e.g., was it in the northern or southern Basin and Range?). If the intent is that the Wells earthquake provides control for a normal faulting earthquake, if one should occur in the Southern Basin and Ranae, olease clarifv and correct, as needed 1078. Line 31 Since this is the first time that the term "PSA is used in the report, please define it. 1079. Line 47 Please add that the bottom frames also show the number of recordings per site class. 1080. Line 85 There is no evidence in Figure 5.1.2-1 of "Station Z14A, shown by the open star". Please clarify. 1081. Line 87 Please complete the citation of Kishida" (i.e., Kishida et al. 2014a or 2014b?). 1082. Line 158 Please correct the figure number on this line, which should be Figure 5.1.5-1. 1083. Lines 173-174 The spelling of the fault names differs between the text and Figure 5.1.5-2 ("ltozawa" in the figure becomes "ldozawa" in the text. and "Yunodake" in the figure becomes .. Yunotake** in the 1ext). Please edit for con sistencv. 1084. Lines 175-176 The 1otal moment given here and attributed 1o personal communication is inconsistent with the moment magnitude of 6. 7 given for this event on Line 164 (the sum of the moments on Line 175 imply M 6.56). Please resolve the inconsistency. In doing so, please consider whether it would be appropriate to cite published moment estimates (e.g., Tanaka et al.. 2014, report a moment consistent with M 6.7 and approximately equally parti1ioned between the two faul1s} instead of those reported from oersonal communication. 1085. Line 202 Please supply the missing Table 5.1. 7-1. 1086. Line 209 The symbols referring to the different types of kappa used in this sentence are slightly different from those listed in the terms and acronyms. Please use a consistent set of symbols for kappa throughout the reoort and aaoendices. 1087. Line 216 K0 is undefined at this point in the text. Please correct this. 1088. Line 223 Please consider whether a more appropriate characterization than "upper bound" can be used here (e.g .. is that categorical statement even consistent with the one standard deviation ranges cited forthe other methods?). 1089. Line 228 Please include a reference to a publication describing the SCEC BBP (e.g., the paper by Maechling et al. in the Jan/Feb 2015 SRL may be aoorooriate ). 1090. Line 242 Please consider citing the published paper by Dreger et al. (2015) in the Jan/Feb 2015 SRL. 1091. Lines 264-266 It is appropriate for the Tl Team to rely on the SCEC Validation Review Panel for the technical analysis of the simulations, and to rely upon the judgment of that panel to determine which methods met the acceptance criteria established in that review. However. the Tl Team itself needs to justify that meeting those acceptance criteria makes the methods suitable for the specific purposes for which the simulations are to be employed. Those purposes are stated on Lines 227-233. Please augment the summary statement on Lines 264-266 by explaining how meeting the SCEC review panel's acceptance criteria makes the simulation methods suitable for addressing the problems laid out on Lines 8-14. 1092. Lines 306-315 This passage needs rewriting because: (1) the BSL model is not identified as GIL7 on Line 309, but seems to be the same as what is called GIL7 in the legend of Figure 5.2.2-1 and then on Line 312; and (2) the passage is repetitive (e.g., the verbiage about routine estimation of moment tensors on Line 309 is repeated on Line 314-315; the basis of the GIL7 model in broadband waveform modeling is stated repetitively on Line 308 and then on Line 3141. 1093. Line 322 "Frequency wave-number is written differently on this line than it was on Lines 304 and 311 ("frequency-wave number"). Please review the hyphenation convention and apply one consistently (note also that both "wave number" and "wavenumber" are in common use, so the easier-to-read form "freauencv-wavenumbe(' is also an ootion). 1094. Line 361, 364 "Area" is used to signify rupture area in Equation 5.2.3-1. but "A is defined as rupture area on Line 364. Please edit for consistency. 1095. Lines 374-375 Please indicate whether this statement is an assumption or is based on an evaluation of data, models, etc., by the Tl Team. 1096. Line 383 Please correct the figure number. It is called out as Figure 5.3.2.1-1 on this line, but the figure itself is labeled as Figure 5.2.3.1-1. Moreover, the numbering scheme used elsewhere in the report appears to call it Figure 5.2.3-1. since it occurs in a subsection of Section 5.2.3 (e.g .. by analogy with the fact that Fiqures 5 2 2-1 and 5 2 2-2 occur in Section 5.2.2.1) 1097. Line 392 The figure number 5.2.3.2-1 is inconsistent with the fact that it is the second figure in the subsection. Please check the figure numbering convention and make it consistent with the rest of the chapter and report. 1098. Line 396 Please indicate that CB14 also used the functional form of the hanging-wall term developed by Donahue and Abrahamson (2014). 1099. Line411 Please consider replacing "we" (first person) with third-person to be consistent with the remainder of the report. 1100. Lines 427, 431. and The figure citations do not correspond to the figure numbering. Please 433 check the figure numbering against the figure citations and correct as needed. 1101. Line 452. 458 The table called Table 5.1.1-2 on this line appears to be the table labeled Table 5.1-2 (and called by those numbers elsewhere in the report). Please correct here and in subse<1uent occurrences. 1102. Line 464. 475. 481 Line 464 gives the distance criterion for NGA-W2_DC-MED as abs(Rx)<70km. whereas the lines 475 and 481 give it as R<70 km, which is more restrictive. Please clarify how the various distance metrics are used toaether to screen records for NGA-W2 DC-MED. 1103. Line 492 Please quantify what .. similar enough" means in regards to the value of Vs30 (e.g., in terms of the percent difference in site-amplification factors). 1104. Line 506 Previously, Akkar et al. (2014c) was cited as the database reference. Please check whether the citation given on this line is correct in the oresent context. 1105. Lines 508 and 517 The criterion abs(Rx)<70 km leaves the total distance unconstrained. Please provide a complete statement of the distance selection criterion. 1106. Line 548 Please consider whether this might be a good place to introduce the symbol ell,., so that ii will be defined prior to its use on Line 553. 1107. Line 558 "Disaggregation .. is used on this line, whereas "deaggregation" is used elsewhere in the report. Please edit for consistency. 1108. Lines 565-572 The selection criteria (distance, magnitude, number of recordings per event and site) do not seem to be given. Please check and correct if necessary. 1109. Line 566 "NGA-W2" is "NGA-West2 .. elsewhere. Please edit for consistency. 1110. Line 579 Please check whether for use in" should be "is used in". As is, the sentence lacks a verb. 1111. Line 585 Please add the missing parenthesis closure. 1112. Lines 592-593 Please indicate whether the 3 events per station requirement was also applied. 1113. Line 601 Section 5.4.1 does not contain the discussion of the Idriss 2014 model that is referenced here ("As noted in Section 5.4. r). nor does there appear to be any prior reference to the Idriss model in the chapter. Please make the necessarv corrections. 1114. Line610 Please replace "200-30 km" with "30-200 km." 1115. Lines 614-615 CB14 used mixed-effects regression to derive the anelastic attenuation term from data with RKuP > 80 km, but allowed the source terms to vary from those for RRuP < 80 km. Although this does not necessarily impact the decision not to use CB14, the description of what CB 14 did should be correctly stated in the text. 1116. Line 619 Please indicate what range that "this magnitude-distance range" refers to. 1117. Lines 619 and 626 Line 619 has the statement that "the global dataset in this magnitude and distance range consists of 264-415 record in gs from 4 to 2 3 earthquakes." Line 625 states "Within this magnitude and distance range, the global dataset contains four earthquakes and 280 records." Please clarify whv these statements are not contradictory. 1118. Line 627 The cited figures do not exist. Please add them. 1119. Line 669-670 Please correct the figure references (they should be to Figures 5. 5 .1-1 and 5.5.1-2). 1120. Line 673 Please correct the figure reference (it should be to Figure 5.5.1-3). 1121. Line 683 Please correct the table reference (the intended reference appears to be to Table 5.5.1-1 ). 1122. Line 724 Please clarify why specific scenarios had to be specified, given that kappa is not being explicitly modeled as a source effect. 1123. Line 725 Please explain why only footwall scenarios were used. 1124. Line 727 Please consider rewording the reference to "Q attenuation," to avoid the implication that the kappa effect is necessarily physically distinct from effects ordinarily parameterized in terms of Q. Isn't the point that the kappa parameter (or at least K.,1) is intended to capture attenuation effects that are so localized that in a practical sense they are better parameterized as site terms than as path-dependent attenuation terms. and that therefore isolation of kappa effects requires short-distance scenarios? 1125. Line 730 Please be more specific about which profile was used. Is it one of those in Figure 2.6 of Kamai et al. (one is listed as having Vs30 of 750 mis. none has exactlv 760 m/s)? 1126. Line 735 Figure 5.5.3-1 appears to be labeled incorrectly. Please correct this. 1127. Line 778 Rodriguez-Marek (2013) actually developed four single-station sigma models: one with neither M nor R dependence, one each with Mand R dependencies, respectively, and a fourth with both Mand R dependence. Please clarify which three have been chosen, and why. Note also that there is a perception of ambiguity introduced by mixing .. dependent" and .. independent" in listing the attributes of the selected models: i.e .. is the .. magnitude-independent" model alluded to also R independent (in which case it would be clearer to say "magnitude and distance independent), or is there a typo such that "magnitude-dependent" is what is actually intended? If one of the figures were not missing, this ambiguity would be cleared up, but it would be better to also do so in the text. 1128. Lines 779 and 781 Please check whether the first of the three models alluded to should be .. magnitude-dependent" (rather than .. magnitude-independent". which would appear to be inconsistent with the figures). Alternatively, if "magnitude-independenr is correct as written, please clarify whether it is paired with a distance dependence or not. 1129. Lines 780-782 Only the R-dependent and MR-dependent models are shown, and these are in Figures 5.6.2-3 and 5.6.2-4, respectively (not 5.6.2-4 and 5.6.2-5 as called in the text). The other model (called "magnitude-independent" in the text) is not shown. nor is there any Figure 5.6-5. Please correct this. 1130. Line 789 Please cite a reference for the assertions about the small-magnitude limitations of GMPEs at short distance. 1131. Line1122 Table 5.5.1-1 indicates that the Graizer (2014} GMPE was used for the DCPP GMC model. but the Graizer GMPE is not listed as being one of the models that was used in Chapter 6 Please either correct the table or the text in Chapter 6. If this GMPE was used, please justify its use in nf tho it nnl\I nl not been peer reviewed or vetted by the larger scientific community. 1132. Figure 5.1.3-1 The caption cites Akkar et al. (2014a and 2014b), whereas the text (Line 121) cites Akkar et al. (2014c), apparently in the same context. Please check whether this difference is intentional and make a correction if aoarooriate. 1133. Figures 52.3.4-1 and These figures are mislabeled (as 5.2.3.3-1 and 5.2.3.3-2, respectively). 5.2.3.4-2 Please correct. 1134. Figures 5 3.2-1 and Please correct these figures. In each of these figures, the second row 5.3.2-2 repeats the first with a scale change. and the remaining plots (recordings oer site, recordinas per event, etc.) are absent. 1135. Line 1258 In Figure 5.4.1-2, please explain why there is a triangular symbol plotted at slightly over 100 km or, if this is an error. please remove the symbol. 1136. Line 1263 In Figure 5.4.1-3, please explain why there is a triangular symbol plotted at slightly over 100 km or, if this is an error, please remove the symbol. 1137. Line 1322 In Figure 5.5.1-1, please define the meaning of the solid black symbols and the color and black trend lines. 1138. Line 1326 In Figure 5.5.1-2, please define the meaning of the solid black symbols and the color and black trend lines. 1139. Figure 5.5.3-1 Please correct the figure number. It is called Figure 5.5.3-1, but labeled 5.5.3-2. 1140. Figure 5.6.2-2 Please improve the figure caption by including some basic contextual information. 1141. Figure 5.6.4-1 Please add the dataset identifiers given in Lines 805-808 of the text (Blea, Blea2, and ABR) to the figure caption, or else delete them from the text, as the inconsistency is confusing. CHAPTER 6-GMC Models for the Median 1142. Lines 23-24 Table 5.5.1-1 indicates that the Graizer (2014) GMPE was used for the DCPP GMC model. resulting in the use of 9 models. The text indicates that 8 models, excluding the Graizer GMPE, were used. Please correct either the table or the text. 1143. Line 105 Please hyphenate "large-distance attenuation" to resolve the otherwise ambiguous meaning. 1144. Lines 209-210 Not all of the simulations show that hanging-wall effects persist down to magnitudes of 5.5 and 6.0 for all fault geometries. This suggests that there is some uncertainty in whether such effects exist. Please discuss this apparent uncertainty and justify the decision to extend hanging-wall effects to smaller magnitudes. explaining whether this uncertainty is accounted for elsewhere. 1145. Lines 256-257 Please explain why. if hanging-wall effects are geometric. the cosine term is more appropriate than the arithmetic angle to model these effects. 1146. Line 269 The statement that the hanging-wall models are "equally likely" and "normally distributed" is still confusing on its face. However, the discussion that follows clarifies this apparent contradiction vis-a-vis the use of equal probability slices of the distribution Perhaps. a statement like "as explained below" after introducing this apparent contradiction would provide less confusion for the reader. 1147. Line 303 Figure 6.3.2-5 shows CB14 having a step-like change in its HW factor as Rjb approaches zero along the strike direction. Please clarify how this is consistent with the claim that CB14 allows "a smoother transition" around the rupture compared with some other models. 1148. Lines 341-343 In reviewing all of the figures comparing the HW adjustment model with the simulations, all except Figure 6.3.2-14 compare the simulations only with the central HW model In order to show that the five HW models adequately capture the uncertainty in the simulations. please show all five HW models in all of the figures and discuss any cases in which the five models to not aooear to caoture the uncertaintv. 1149. Line 363 The term "scaled-backbone approach" is never used by Atkinson et al. (2014). These authors do mention the concept of selecting a single "central or backbone GMPE" and scaling it up and down, but do not specifically call this a scaled-backbone approach. Please consider replacing the term "scaled-backbone approach" with a simple description of the aaoroach instead. 1150. Line 384 The term "generated models" is used in this sentence to refer to ground motion models derived from the visualization (Sammon's mapping) technique. Terms such as "large suite of models" and "representative models" were used earlier in the section to refer to similar models. The concept of using visualization techniques to produce a distribution of models that sample the full model space is difficult enough to understand without being confused further by the use of different terms to describe the same technique or products thereof. In order to avoid such confusion, please consider using a consistent and strict set of terminology to refer to these models. For example, the term "candidate models" has been generally used to describe the GMPEs that are used in conjunction with the visualization method, since this term is used elsewhere in the report to describe such models: the term "suite of models" might be used to refer to the entire set of models that are generated using the visualization technique (e.g .. the 2000 common-form models); and the term "representative suite of models" might be used to refer to the final set of models that are used in the GMC logic tree (e.g., the 25 or so common-form models). This latter term is also consistent with the general term used by Atkinson et al. (2014) to describe the method of generating models that sample the model space. whether it be by simple methods (i.e., scaling up and down) or by more comolex models, such as those samoled from the Sammon's mao. 1151. Line 402 It is possible that this is the first time that the term "Joyner-Boore distance is used in the report. If so, please note that this term refers to the distance metric R,s. 1152. Lines412-413 Please delete "0,c" and replace "(fork= 7,8,9, 10)" with "(fork= 7,8,9)" since there is no k = 1 O coefficient in the model. 1153. Line 429 Please replace "(fork= 7.8.9, 10)" with "(fork= 7,8,9)" since there is no k = 10 coefficient in the model. 1154. Line 433 Please replace "fork= 7,8,9, 10" with fork= 7,8,9" since there is no k = 10 coefficient in the model. 1155. Line 444 Please replace "fork= 7,8,9 and 10" with "fork= 7,8 and 9 since there is no k = 10 coefficient in the model. 1156. Line 449 Please justify the selection of +/-3 km to represent the uncertainty around the mean value of ZrnR* 1157. Lines 463-464 In order for R,e to equal IRxl. the footwall site must be located at a source-to-site azimuth of -90 degrees (i.e., perpendicular to the fault within the bounds of the ends of the rupture). Please indicate that this is the case in order to iustifv the aiven distance eaualities. 1158. Lines 472 and 493 The term "total residual" is usually reserved to mean the addition of the between-event and within-event residuals in the aleatory variability model Please consider calling this the "total fitted residual" or something like that to distinauish it from the true total residual 1159. Lines 502-513 The entire discussion of using candidate GMPEs and interpolated versions of the GMPEs and the generation and simplification of the coefficient covariance matrices is confusing to a non-statistician. For example, what exactly are the sets of weights applied to and why can the covariance matrices be simplified in the manner discussed? Please consider expanding this discussion to better explain and justify exactly what was done. 1160. Lines 506-513 Please justify how it is mathematically possible with the addition of the interpolated GMPE ground motions to better capture the correlations? 1161. Line 524 Please be precise about what types of "standard deviations" are plotted in Figure 6.4.3-1. 1162. Lines 536-548 This explanation needs to be set out more clearly. The sentence beginning on Line 536 states that "for the DCPP application ... the central HW branch is applied to all common-form models." The rest of the passage. although rather difficult to read. appears to indicate the following: ( 1) HW effects are omitted from the 2000 models used for the Sammon's map, (2) the central HW model is appended to those footwall models, solely for the purpose of the simplified hazard calculations used in the selection of representative common-form (footwall) models from the original 2000. and (3) randomly selected HW models (from the equal-probability set developed in Section 6.3.2) are appended to the selected representative set of footwall models, to give the final set of common-form models for application to DCPP. If this is a correct interpretation, then the last item seems to contradict the sentence from Line 536 (and if this is not a correct interpretation, some clarification is needed). Please rewrite for clarity and consistency. This paragraph would be less confusing if a strict use of terminology to identify all of the different types of models were used. as suggested in an earlier comment. Please be more specific in identifying what set of models are being described in each case. such as candidate models (i.e., the original published GMPES), common-form models (i.e., the mean and interpreted GMPEs and presumably the 2000 or 7500 count versions as well), representative model (i.e., the common-form model that best matches the mean hazard in a given cell), and the suite of representative models (i.e., the ones that are eventually used in the logic tree). 1163. Line 552 Please be explicit as to whether this paragraph is discussing the development of representative models for both sites or just PVNGS. 1164. Line 564 Please replace "magnitude/distance" with "magnitude-distance." 1165. Line 602 Please review the appropriateness of subscript k in NGk. given that there is already a sum over k. 1166. Lines 614-615 Please justify why uncertainty in Ztor is represented by adding 3 km to Ztor and not also subtracting 3 km and why the value of 3 km was chosen to represent this uncertainty (see previous comment). 1167. Lines 616-618 Please explain why a value for Ztor is needed in the R.1A-based models when ii was not used as a term in these models, i.e., how can one Ztor value" be used if the models do not include Ztor at all? 1168. Line 629 Please correct the spelling of the second occurrence of "PVNGs:* 1169. Line 632 Please check whether the intent of this sentence would be more clearly expressed if the final clause were included inside the parentheses. 1170. Line 633 It appears from Eq. 6.4-4 that it is the contributions to the Euclidean distance squared that are weighted by the weights from Eq. 6.4-7 (not the contributions to the Euclidean distance itself. as stated). Please correct or clarifv. 1171. Lines 689-690 The phrase " ... then the point that corresponds to the position of the candidate GMPEs is selected .. is confusing. Please rewrite this phrase to make its meanina clearer. 1172. Line 704 Please correct the typo, ie . "two week" should be "too weak." 1173. Line 706 Please provide a brief statement. or reference. that describes a "Voronoi-diagram" or the section(s) of an appendix where such a reference or definition can be found. 1174. Lines 719-720 Is it true that all of the models within a given Voronoi cell do not really represent the same level of probability on the ground-motion distribution? If this is true, the use of equal weights is an assumption. Please justify the use of equal weights to determine the weighted mean hazard in each cell. 1175. Line 726 Please discuss the common form model that corresponds to the highest hazard curve in Figure 6.4.4-4 and explain why it falls so far above the cluster defined by the rest of the models in the same cell. 1176. Lines 735-736 Although the distribution of HW models is nearly uniform for the DCPP representative models. the distribution of the hazard might not be. depending on what Voronoi cells received the higher HW models (i.e., the high-hazard cells or the low-hazard cells). Please justify that the mean hazard is not biased by the random selection of HW models. 1177. Lines 762-763 Please clarify what results" are not sensitive to the discretization size of the Voronoi cells (i.e., the weights or the hazard). It is possible that the hazard will be sensitive to the size of the cells (e.g., what if only one cell were used?). 1178. Lines 804-807 Please show an example contour plot in Chapter 6 for those readers that do not care to read Appendix H. 1179. Lines 808-809 Please show an example distribution plot in Chapter 6 for those readers that do not care to read Appendix H. 1180. Line 879 Two consecutive figures are called "6.4.5-8." Please check and renumber as needed. 1181. Lines 927-928 The sentence starting with "Randomizing" appears to be unconnected to the rest of the paragraph. Please expand or rewrite this sentence to better convey is meanina. 1182. Line 929 Please see the general comment regarding the documentation of the directivity model evaluation. 1183. Lines 937-939 If the standard deviation represents the variability in the hypocenter location, please explain what the median (or should ii be the mean) represents (e.a., the bias?). 1184. Lines 951-953 Please justify why it is not necessary to include Ztor as a directivity parameter for those events that do not rupture to the surface (e.g., the directivity effects for M5.5-6.5 events that the GMPEs were evaluated for). 1185. Lines 962 -964 Please include sufficient details of the Tl Team's evaluations of the technical merits and limitations of the simplified directivitv model in support of the decision to adopt this model for use in hazard calculations (as also requested in one of the general comments). 1186. Lines 965-967 Please explain the basis for the evaluation that the simplified directivity model is a reasonable approach for capturing directivity effects (e.g., was the hazard using the CY14 directivity model and random hvoocenters comoared to that usina the simplified model?). 1187. Lines 981-982 Please identify which event NGA EQ ID 1017 represents and why it is justified to remove this event because the event-terms of the GMPEs are not consistent. 1188. Lines 990-991 Please explain why there is a difference in plotted values between Figure 6.6.1-2 and Figure 7.4.1-6. 1189. Lines 1008-1009 There seem to be two sets of LN values being given in this section The -0.5 and +0.1 LN units listed in the previous paragraph appear to be biases in the log PSA values, whereas, the 0.32 and 0.35 LN units given in this paragraph appear to be standard deviations. Please make the distinction between these two sets of values clear in the text. Please also be more specific about what "numbers" (the biases or the standard deviations) the Tl Team considers to be "reasonable" 1190. Lines 1015 The use of the term "proponent model" or proponent method is confusing, since it can be interpreted as a model or method being proposed by a Proponent Expert (PE}. If these models and methods are proposed by the Tl Team. please replace "proponent" with "Tl Team" in this line and elsewhere in Section 6.7 where the term is used 1191. Line 1036 Please delete the phrase "with similar rake. dip. width," which is incorrect based on the contradictory and apparently correct description given on Line 1039. 1192. Line 1039 Please note that this statement appears to contradict the phrase on Line 1036, which has been interpreted to be a typo in a previous comment. 1193. Lines 1064-1065 The sentence "The ground motions from the 2011 Fukushima-Hamadori earthquake are evaluated using the SRSS method in Section 9.1.5.2." appears to be disconnected from the sentences before and after it. It is also ambiguous what the "Therefore .. " at the beginning of the next sentence is referring to. Please rewrite these sentences to better convey their intended meanina. 1194. Line 1076 Please explain which complex rupture "Complex Scenario 18" represents. 1195. Line 1096 Please explain which splay rupture "Splay Scenario 1C" represents. 1196. Line 1300 Please confirm whether "Model A" should be included in the title to Table 6.4-2. 1197. Line 1343 Please confirm that the CB14 GMPE is plotted correctly in the lower plot (M6.6, SS, PGA). 1198. Line 1354 Please confirm that the GMPEs are plotted correctly in this plot. For example, CB14 appears to have a hinge or kink at M7, but its magnitude scalina term does not. 1199. Line 1359 Please identify the models listed in the legend to Figure 6.2 3-1 by their correct acronyms (i.e .* ASK14 instead of ASK). 1200. Line 1380 Please identify the models listed in the legend to Figure 6.31-2 by their correct acronyms (i.e .* ASK14 instead of ASK). 1201. Line 1386 Please identify the models listed in the legend to Figure 6.3.2-1 by their correct acronyms (i.e., ASK14 instead of ASK2014). Please also justify in the text why it is acceptable for the predictions from the proposed HW models 1o no1encompass1he predictions from all of the GMPEs. 1202. Line 1391 Please identify the models listed in the legend to Figure 6.3.2-2 by their correct acronyms (i.e., ASK14 instead of ASK2014). Please also justify in the 1ext why it is acceptable for the predictions from the proposed HW models to no1 encomoass the predictions from all of 1he GMPEs. 1203. Line 1396 Please identify the models listed in the legend to Figure 6.3.2-3 by their correc1 acronyms (i.e .. ASK 14 ins1ead of ASK2014 }. Please also justify in the 1ext why it is acceptable for the predictions from the proposed HW models to not encomoass the predictions from all of the GMPEs. 1204. Line 1401 Please identify the models listed in 1he legend to Figure 6.3 2-4 by their correct acronyms (i.e .* ASK14 instead of ASK2014). Please also justify in the text why it is acceptable for the predictions from the proposed HW models to not encompass the predictions from all of the GMPEs. 1205. Line 1406 Please identify the models listed in the legend to Figure 6.3.2-5 by their correct acronyms (i.e .* ASK14 instead of ASK2014). 1206. Line 1409 Please identify the models listed in the legend to Figure 6.3.2-6 by their correct acronyms (i.e., ASK14 instead of ASK2014). 1207. Line 1432 In Figure 6.3.2-11, please justify in the text why it is acceptable for the predic1ions from the HW models to not encompass all of the predictions from the simulations. 1208. Line 1438 In Figure 6.3.2-12, please justify in the text why it is acceptable for the predic1ions from the HW models to not encompass all of the predictions from the simulations. 1209. Line 1444 In Figure 6.3.2-13. please justify in 1he text why it is acceptable for the predic1ions from the HW models to not encompass all of the predictions from the simulations. 1210. Line 1448 In Figure 6.3.2-14. please justify in 1he text why it is acceptable for the predictions from the HW models to not encompass all of the predictions from the simulations. 1211. Lines 1472 (Figure The plot for the Idriss model is labeled "114." inconsistent with "ld14" 6.4.1-4a), 1475 elsewhere in the chapter. Please modify for consistency. (Figure 6.41-4b}. 1478 (Figure 6.4. 1-Sa}. and Line 1481 (Fiaure 6.5.1-Sbl 1212. Line 1529 In Figure 6.4.3-3, please explain the meaning of "NGAW2rv-MFn MODEL A" in the upper-left corner of the plot. 1213. Line 1552 In Figure 6.4.4-1, please explain the meaning of "NGAW2nc-MFn" in the upper-left corner of the plot. Please also explain what the different colors for the solid circles representing the GMPEs and their epistemic uncertainty refer to and what the grey circles represent. 1214. Line 1557 In Figure 6.4.4-2, please provide a legend for the color contours and explain 1he meaning of the grey ellipses and circles. 1215. Line 1567 In Figure 6.4.4-4, please define the axes labels and explain the meaning of "TOO 1 DCCP4 MODELA" in the upper-right corner of 1he bottom plot. 1216. Line 1586 (Figure The caption states that the GMPEs are in black, but the legend indicates 6.4.5-2b) a different color. Moreover. the color assignments differ from those in Figure 6.4.5-2a. Please modify for consistency between caption and leaend, and between 1he a and b oarts of 1he fiaure. 1217. Line 1623 In Figure 6.4.5-7, please justify why it is acceptable for the predictions from the proposed model to not encompass all of the predictions from the candidate GMPEs. The inference is that there is less than 5% confidence in those GMPE predictions that fall outside of the limits of the model. 1218. Line 1630 In Figure 6.4.5-8, please justify why it is acceptable for the predictions from the proposed model to not encompass all of the predictions from the candidate GMPEs. The inference is that there is less than 5% confidence in those GMPE predictions that fall outside of the limits of the model. 1219. Line 1666 In Figure 6.5.1-3, please explain what directivity model is used to make the plot and where the epicenter andfor hypocenter is located on the fault. 1220. Figure 6.7.2-2 Please label the vertical axis and explain the meaning of the term "ground motion factors" in the caption. 1221. Figure 6.7.2-3 Please identify the GMPEs associated with the respective colors, and the meanings of the different styles of grey lines, and make improvements to the legibility of the figure (note also that the figure did not appear in its entirety in the supplied PDF version). Also please exolain the meanina of the term "around motion factors" in the caotion. 1222. Figure 6.7.2-5 Please label the vertical axis and explain the meaning of the term "ground motion factors" in the caption. 1223. Figure 6.7.2-6 Please identify the GMPEs associated with the respective colors, and explain the meaning of the term "ground motion factors" in the caption. CHAPTER 7-GMC Models for the Sigma: Overview and Methodology 1224. Lines 8-9 Please note that by the sigma terminology of Al Atik et al. (201 O) "single-station within-evenf' standard deviation should be "single-site within-event" standard deviation. Please consider consistently using the terminoloav of Al Atik et al. 120101. 1225. Line 74 Please consider assigning the Zhao et al. (2006) model the acronym used in Chapter 6 (i.e., ZH06) as shorthand in the remainder of the chapter. 1226. Line 84 Please add the missing words in this sentence (which currently reads "and chose through the). 1227. Line 87 Please consider revising "smooth" to "constant. 1228. Line 155 Please consider using a different word than "proponent" on this line and elsewhere in the chapter to explain the different Tau and Phi models so as not to confuse them with models that have been proposed by Prooonent Exoerts (PEsl 1229. Line 177 Please rewrite the sentence beginning with The mean ' values ... " to better convey its meaning. The second half of this sentence appears to be incomplete. 1230. Line 183 Please correct the figure citation. which should be to Figures 7.2.3-2 and 7.2.3-3 (not "7.2.3-3 and 7.2.3-3"). 1231. Line 191 Please replace the term "proponent" with the term "candidate" to be consistent with terminology used elsewhere in the report. 1232. Line 195 Please replace the term "proponent" with the term "candidate" to be consistent with terminology used elsewhere in the report. 1233. Line 197 Please rewrite the final sentence of the paragraph to clarify its meaning (i.e .. a "value" cannot be similar to a "model," so it is not clear what point the sentence is trvina to convevl. 1234. Line 202 Please change oss to a,. 1235. Line 207 Please replace the term proponent" with the term candidate" to be consistent with terminology used elsewhere in the report. 1236. Line 232 Please describe the type of distribution used in the simulation. 1237. Line 269 Please indicate whether Dawood et al. (2015)" should be replaced with "Dawood et al., 2014 -in press .. and, if not, please provide the reference to the former. 1238. Lines 271-275 This paragraph appears to be contradictory and the Tl Team decision to use a magnitude-independent Phi_ss is not well supported by the first sentence in the paragraph and the results in Figures 7 3.2-1. Please expand this paragraph to better discuss and justify the decision to use a mac:mitude-independent model for Phi ss. 1239. Line 273 Please correct the inconsistency between the phrase "shown ... for four spectral periods" and the list (PGA, 0.1,0.5, 1.0,3.0 sec), which (like the figure itself) includes five periods (PGA in addition to the four given spectral periods). 1240. Line 276 Please explain why the Phi_ss values of the GLOBAL datasets for each GMPE are only shown for five periods in the figures and indicate, if only five values were used in the analysis. why Phi_ss values for the other oeriods are not used. 1241. Line 320 Please describe how CV(<Jl, * .) = 0.12 was derived. 1242. Line 388 Please avoid the use of the first person "us." 1243. Line 396 The statement that the between-event residuals were provided by the NGA-West2 developers is contradictory to the statement on Lines 404-405 that the Tl Team calculated the residuals. Please rewrite the text to remove this contradiction. 1244. Line 404 Please avoid the use of the first person "we." Since the use of first person has appeared several times in this chapter, please search the entire chapter for other uses of first person and convert them to third oerson. 1245. Line 407 This statement is confusing and again suggests that the between-event residuals provided by the developers are perhaps being used. Please consider rewriting or expanding this entire section to make the process of develooina the LO sinale-oath standard deviations less confusina. 1246. Line415 Please change oW;1 to oW;,. 1247. Line 730 In the Figure 7.2.4-4 caption, please consider replacing the word "proponent" with "candidate" to be consistent with how these models are referred to elsewhere in the reoort. 1248. Line 744 In the Figure 7 2 5-1 caption, please consider replacing the word "proponent" with candidate" to be consistent with how these models are referred to elsewhere in the report. 1249. Line 469 Please explain what is the first issue. 1250. Line 784 In Figure 7.3.2-3, please consider showing the periods with average "no-Lin et al. Data" to show that these values are also bracketed by the low and hiQh proposed values. 1251. Line 812 In the Figure 7.3.3-1a caption, please describe what the black solid and dashed lines represent. Also, in this and many otherfi11ures there are error bars on the symbols. but no mention of them in the legend or the caption. Please define the meaning of the error bars in this and other figures in this chapter and for similar figures elsewhere in the report where thev miaht aooear. 1252. Line 821 In the Figure 7 3 3-1 b caption. please describe what the black solid and dashed lines represent. 1253. Line 898 In Figure 7.4.2-1, this figure clearly demonstrates that the assumption that the standard deviation is constant at low and high periods is totally unsupported by the data (note that the values at 0.2 sec were not used because of reliability issues). Please further justify in the text why it is appropriate to extrapolate the first and last values as constant values to lower and higher periods and why the uncertainty should not become larQer at low and hiqh periods Qiven this added uncertainty. CHAPTER 8-Median GMC Models: DCPP Sources 1254. Section 8.2.2. There does not appear to be a reference to Figure 8.2-3. Please check general comment and add a reference to this figure if one is missing. 1255. Lines 60-61 Please explain the bases for the values used to define the three branches and their weights included in the second node of Figure 8.2-3 1256. Line 100 This is not necessarily true for the Akkar et al. (2014a,b) and Bindi et al. (2014a.b) GMPEs that were developed using subsets of the RESORCE database and with at least some interaction between them under the ausoices of the SIGMA oroiect. Please clarifv this statement. 1257. Line 125 Please add the missing word "models" after "common-form". 1258. Line 167 Please improve clarity by adding a sentence break after the word "model." 1259. Lines 293-295 Please reference where in the report the evaluation of ld14 was done to determine that it was unreliable for R1wP < 3 km at large magnitudes. 1260. Line 302 Please indicate what models are being compared in Figure 8.4-8. The discussion references both the common-form models and the candidate GMPEs and it is not clear which is being referred to when not explicitly stated in the text. 1261. Line 310 Contrary to this sentence, curves corresponding to the epistemic uncertainty are not included in Figure 8.4-9. Please add the curves or modifv this sentence to remove reference to epistemic uncertaintv. 1262. Line 355 Please provide evaluations or provide a cross reference in support of the conclusion that "differences in the magnitude and distance scaling will also imoact the ranae of the hazard. 1263. Lines 360-361 Please explain what will need to be done if in the future the hazard model is changed. For example. will an evaluation of the GMC model need to be redone because its validity was based. in part. on the hazard calculated from a specific hazard model (i.e., hazard-calibrated)? If that is the case, it is important that such a caveat be clearly communicated in the report. Please note that there are other instances in this and other chapters where hazard was invoked as demonstrating that the range in the models is adequate, which should also be included as part of this comment. 1264. Lines 367-370 Please explain why the versions of the candidate GMPEs with added epistemic uncertainty are not considered in the comparison. 1265. Line 388 Figure 8.4-7 is missing or skipped over Please correct this oversight. 1266. Figure 8.2-2 Please correct the weight for "Sim_DC-MED," (i.e., shouldn't it be 0.25?). 1267. Line 522 In Figure 8.4-1, please provide labels for the color legend bars and define what the light grey ellipses and points represent. 1268. Line 533 In Figure 8.4-2, please provide labels for the color legend bars and define what the light grey ellipses and points represent. 1269. Line 547 In Figure 8.4-3, please explain what DCPP Model A is, given that there appears to be only one DCPP model. 1270. Line 569 In Figure 8.4-6, there does not appear to be any dashed black" lines. Please revise the caption to refer to the actual color scheme used in the fiaure. 1271. Line 580 In Figure 8.4-8, there does not appear to be any dashed black" lines. Please revise the caption to refer to the actual color scheme used in the fiaure. 1272. Line 594 In Figure 8.4-9, there does not appear to be any "dashed black" lines. Please revise the caption to refer to the actual color scheme used in the fiaure. 1273. Line 645 In the Figure 8 4-14 caption, please describe what models the phrase "individual models refer to. 1274. Line 651 In the Figure 8 4-15 caption, please describe what models the phrase "individual models refer to. 1275. Line 656 In the Figure 8 4-16 legend, please refer to the various models by the acronyms used throughout the report (e.g., ASK14 instead of ASK). 1276. Line 662 In the Figure 8 4-17 legend, please refer to the various models by the acronyms used throughout the report (e.g., ASK14 instead of ASK). 1277. Line 665 In Figure 8.4-18. please define what the light grey lines represent in the legend or the caption. 1278. Line 670 In Figure 8.4-19. please define what the light grey lines represent in the legend or the caption. CHAPTER 9-Median GMC Models: PVNGS Sources 1279. Line 38 Please follow the standard practice of numbering figures in the order in which they are first called in the text, which is not the case with the figure called on this line. 1280. Line 54 Chapter 6 of this report and the report on the SSC model use the term "virtual fault", rather then "pseudo fault." Please revise for consistency with those other usaaes. 1281. Lines 74-75 The Akkar et al. (2014a,b) and Bindi et al. (2014a.b) GMPEs were developed using subsets of the RESORCE strong-motion database under the auspices of the SIGMA project. Please indicate that these two models are likely correlated. although perhaps not to the extent of the NGA-West2 models Please also note that this is not an issue. since epistemic uncertainty was applied to these models as well as to the NGA-West2 models. 1282. Line 108 Please specify the type of "residual" (i.e., between-event). 1283. Lines 173-174 The sentence beginning "The limitation ... " is confusing. Please reword it or expand it to make its meaning clearer. 1284. Line 187 Please make it clear which mechanism each of the weights refers to. 1285. Line 256 Please correct the figure reference; the reference to Figure 9.1-10 should actually be to Figure 9. 1-9. 1286. Line 371 Please correct the figure reference on this I ine (it should be 9. 1-19 ). 1287. Lines 475-476 Please indicate where the technical justification and bases for these statistical weights are given (i.e., Appendix P). 1288. Lines 478-481 The stated justification seems weak; there are few recordings at 200 to 400km distance range in the ground-motion database. On the other hand. it would appear that there is no need to consider directivity because its effect. as modeled in CY14, is zero at such large distances. Please revise to clarify the justification for the Tl Team's iudament 1289. Line 545 In the heading of the last column in Table 9 .1-1 , please replace the term "SFo** with "SOF" to represent style of faulting. 1290. Line 557 In Figure 9.1-2a. please label the color legend bars and describe what the light grey ellipses and circles are on the plots. 1291. Line 567 In Figure 9.1-2b. please label the color legend bars and describe what the light grey ellipses and circles are on the plots. 1292. Line 577 In Figure 9 .1-3a. please label the color legend bars and describe what the light grey ellipses and circles are on the plots. 1293. Line 587 Figure 9.1-3b. please label the color legend bars and describe what the light grey ellipses and circles are on the plots. 1294. Line 607 Please provide a specific reference to "Akkar et al." 1295. Line 637 In Figure 9.1-8, the plots do not appear to have any "dashed black" lines. Please revise the text to better describe the lines. 1296. Line 645 In Figure 9.1-9, the plots do not appear to have any "dashed black" lines. Please revise the text to better describe the lines. 1297. Line 653 In Figure 9. 1-10, the plots do not appear to have any "dashed black" lines. Please revise the text to better describe the lines. 1298. Line 661 In Figure 9. 1-11, the plots do not appear to have any "dashed black" lines. Please revise the text to better describe the lines. Please also further justify in the text why it is acceptable for some of the predictions from the GMPEs to fall outside of the range of the representative models at some periods. Note the concern in previous comments of using only the hazard distribution alone to justify the range in the representative suite of models. 1299. Line 709 In the Figure 9 1-13 caption. please describe what is meant by "individual models," and consider making changes such that the upper and lower parts of the figure have the same vertical scale. 1300. Line 714 In the Figure 9.1-14 caption, please describe what is meant by "individual models." 1301. Line 718 In the Figure 9.1-15 caption, please describe what is meant by "individual models." 1302. Line 724 In the Figure 9. 1-16 caption, please describe what is meant by "individual models." 1303. Line 729 In the Figure 9.1-17a caption, please describe what is meant by "selected models." Please consider using a consistent set of terminology for the different types of models that are described throughout the report to make it less confusing to the reader. Please also use a consistent set of acronvms in the leaend (e.a., ASK14 instead of ASK). 1304. Line 738 In the Figure 9. 1-17b caption, please describe what is meant by "selected models." Please also use a consistent set of acronyms in the legend (e g. ASK14 instead of ASK) 1305. Line 742 In the Figure 9. 1-18a caption, please describe what is meant by .. selected models." Please also use a consistent set of acronyms in the legend (e q. ASK14 instead of ASK) 1306. Line 748 In the Figure 9. 1-18b caption, please describe what is meant by .. selected models." Please also use a consistent set of acronyms in the legend (e q. ASK14 instead of ASK) 1307. Line 759 In Figure 9 .1-19. please use a consistent set of acronyms in the legend (e.g., ASK 14 instead of ASK). 1308. Figure 9.2-1 Please correct the abbreviation for the Idriss (2014} model to be consistent with usage elsewhere in the report. CHAPTER 10-'t Model Logic Tree for both DCPP and PVNGS 1309. Lines 25-26 Please also mention that the standard deviations of ASB14 and Bi14 are independent of magnitude, which was an important property of the models that the Tl Team used to reject them. 1310. Line 38 Although the use of the term "proponenr in this context is technically correct, it is inconsistent with the term "candidate" used throughout the report to identify such proponent models. Please consider replacing .. proponent" with .. candidate .. to be consistent with the description of such models throughout the report. 1311. Line 47 Please add the term .. scaled" before "Chi-square distribution." 1312. Lines 51-53 The three-point approximation scheme (as described in Appendix P) applies (0.2. 0.6. 0.2) weighs to the (5th. 50th. 95th) percentiles. Please explain the appropriateness (or point to a place where such explanation was given) of giving a 0.6 weight to the central branch representing the mean (which may not be the so** percentile of a Chi-square distribution). CHAPTER 11-4> Model Logic Tree: DCPP 1313. Line 27 Please clarify if interpolation and extrapolation were also needed for the California-only data subset, which includes data at the full set of spectral periods. 1314. Line 53 Statistical evaluation of the standard error of o .. was not given in Appendix P. Please verify and correct the cross reference as needed. 1315. Lines 53-58 Please refine this paragraph to give a clear and accurate summary of the approach described in Section 7.3.1. 1316. Line 64 Please qualify the term "correlated .. in a way that is similar to Lines 4-5 of Chapter 12. 1317. Line 71 Please consider revising the term "intra-event" to "within-event" to be consistent with the terminology generally used throughout the report. 1318. Lines 78-79 and 88-Please define the level of significance for the presumed departure from 89 normality. It might be obvious to the Tl Team, but not necessarily to the reader. that a point falling outside the 95% confidence interval can be considered to depart from normality at the 5% level of significance. Besides. others might consider "significant" to be at the 10% level of significance. 1319. Line 105 Please be specific whether the same weights of the mixture models that were found to be appropriate for CY14 are "similar or the "same" as found for ASK14. 1320. Lines 108-112 Please provide a context for this paragraph. 1321. Line 127 Please insert a space after o. 1322. Line 133 Please consider revising the term "intra-event to "within-event to be consistent with the terminology used throughout the report. 1323. Line 188 In the Figure 11-2 caption, please consider revising the term "intra-event" to within-event" to be consistent with the terminology used throughout the report and define the meaning of the term "normalized " Please also define the solid and dashed red curves. In addition. note that panel b) is stated as being forT=2 sec. but the y-axis label indicates it is for T=0.5 sec. Please correct this inconsistencv. 1324. Line 191 In the Figure 11-3 caption. please describe whattype of "residuals" are referred to in this figure. Please also define the solid and dashed red curves. 1325. Line 194 In the Figure 11-4 caption, please describe what type of "residuals are referred to in this figure. Please also define the solid and dashed red curves and provide the missinq red curves on the riqht plot. 1326. Line 201 In Figure 11-5, both of these plots appear to be incomplete and the left plot is not consistent with the right plot. Please correct these plots to be consistent with other similar plots in the chapter. 1327. Line 212 In Figure 11-6, both of these plots appear to be incomplete and the left plot is not consistent with the right plot. Please correct these plots to be consistent with other similar plots in the chapter. 1328. Line 218 In Figure 11-7. both of these plots appear to be incomplete and the left plot is not consistent with the right plot. Please correct these plots to be consistent with other similar plots in the chapter. CHAPTER 12-qi Models Logic Tree: PVNGS 1329. Lines 3-5 The first paragraph appears to be awkwardly placed. Please consider placing this paragraph in a more appropriate place in the chapter. 1330. Line 45 Please remove the reference to DCPP, since this chapter addresses the Phi model for PVNGS. 1331. Line 69 Please correct "biased-corrected" to bias-corrected. 1332. Line 90 Lines 486 and 487 on Page 7-16: CV=O. 17 of was based on the variability and the mean ofo ... estimates for the four individual GMPEs. Please clarify or correct the statement .. based on sample size" in the case of 1333. Line 146 Please replace "02" with "0.2." CHAPTER 13-Total Sigma Model 1334. General The use of the term "total sigma" instead of the more accurate "total single-site sigma" tends to neglect the fact that only a single-site sigma model was adopted. Please consider replacing the term "total sigma" with "total sinale-site sioma" to emphasize this point. 1335. Line 7 Although the Greek letter "q1** and 1he Greek symbol "o .. both represent Phi. it is common in engineering seismology to use the latter. which has also been used elsewhere in this report to represent Phi. Please select one of these letters/symbols to represent Phi and use it consistently throuahout the reoort in order to avoid confusion. 1336. Line 10 Eq (13-1) is very generic and does not represent the actual aleatory variability models that are proposed. Please consider replacing this equation with two equations: one that represents the total single-site sigma without path terms and one that represents the total single-site siama with path terms, as discussed in the text that follows the equation. 1337. Lines 30-31 Although the use of only a total [single-site) standard deviation epistemic logic tree is conceptually fine. it appears to prevent the ability to test the sensitivity of the hazard results to the individual between-event and single-site within-event epistemic uncertainty models. Since sensitivity to each type of model is provided in Chapter 14, please explain how someone else can test this sensitivity given that the final model presents onlv a sinqle total lsinqle-sitel siqma model. 1338. Line 55 Please replace the term cumulative distribution" with the more accurate term "cumulative distribution function" 1339. Line 57 Please add a sentence to explain the utility of Eq (13-3). 1340. Line 61 Please correct the missing factor of two in Eq (13-5) (this typographical error is noted here just as a reminder: it has already been noted by the Tl Team). 1341. Lines 62-63 Please further describe these analyses or provide a reference where the results of these analyses can be found 1342. Line 66 Please correct a possible typo: should cr .. be changed to<jl,.,? 1343. Line 75 Please correct a possible typo: should qi" be changed to cr,.,? 1344. Line 77 Please correct the typo ("bi-linear") and add the missing word (i.e .. missing "to" in "leads to"). 1345. Line 79 The Tl Team responded to PPRP's Comment 175 by adding the sentence "Appendix P presents typical examples of the calculations." However, such example calculations were not given in Appendix P. Please provide these missing calculations. 1346. Lines 89 and 90 To be consistent with the usage in the embedded table on Line 93, please consider adding subscript SS" to symbol a. 1347. Line 90 Please assign the embedded table a number and a title so that it can be referenced by table number if needed. and correct any subsequent table numberina as necessarv. 1348. Lines 98. 99 and 100 Please explain why directly computed a" at magnitudes between M 5 and M 7 at 0.1 units were not used in fitting Eq (13-8)? 1349. Lines 102-103 Please provide a reference for the statement beginning "Minimization of the difference . ". 1350. Line 118 Please check the correctness of the reference to Section 13. 1; should it be Section 13.2? 1351. Line 154 Please clarify whether "the method" refers to the semivariogram analysis method (ie .. the current sentence construction leaves some ambiguity). 1352. Line 160 The Tl Team presented its evaluation and decision on the modeling of the effects of spatial correlation on cr.,, for the magnitude-independent cr .. model only. Please also provide discussions for the magnitude-dependent a,, models. 1353. Line 184 Please repair the typos on this line. 1354. Lines 267. 270 and Please indicate in each figure which branch includes the spatial-273 correlation effect on o". CHAPTER 14-Hazard Sensitivity 1355. Lines 7-8 It appears awkward to state that the hazard sensitivity analyses for the final GMC model was done on preliminary versions of the SSC models without providing some sort of caveat. This can be avoided by stating that ii is the responsibility of the individual NPPs to conduct thorough sensitivity analyses for their individual sites and that the sensitivity results provided herein are for demonstration purposes and for purposes of makina hazard-informed decisions 1356. Line 60 There is no mention of deaggregation in the introduction to this chapter. Please introduce this concept and discuss what it is used for in the introduction to the chapter prior to presentinq the deaaqreqation results. 1357. Line 81 Please add the term .. mean" before "hazard level" to be clear that the results represent the mean and not some other fractile (e.g., the median) hazard. Hazard is used without prefacing it by mean many times throughout the chapter. If mean is not added to all of the instances where the hazard level is mentioned, then please state that this is the case for the remainder of the chapter in order to avoid confusion. 1358. Line 88 Please consider rewriting the caption (i.e., the "hazard at hazard" juxtaposition somewhat obscures the meaning). 1359. Line 103 Please define the term "sensitivity case and be as specific as possible about what figure(s) are being referenced in the discussion. 1360. Line116 The text on this line states that HW Models 5, 11 and 21 were selected for the 0.5 Hz tornado plots. but the figure legends for the 0 5 Hz cases indicate that Models 5. 13 and 23 were used. Please check and correct as necessarv. 1361. Line 151 Although the sigma model started as separate Tau and Phi_ss models. in the end a single total single-site sigma model was used. Please acknowledge that here and describe that the individual Tau and Phi_ss models were used for purposes of the sensitivity analyses. Also describe how the user of the model can conduct a similar sensitivity analysis usina their own hazard code. 1362. Line 152 This statement implies that "Model 1" is always the central model of the representative suite of models. If there is some numbering convention for these models, please describe that convention. 1363. Line 168 It is awkward that the first sensitivity analysis appears on the fifth line of the tornado plot. Please consider here and elsewhere in the chapter discussing the sensitivity cases starting with the top line of the tornado plot and descending down the plot to make the discussion less confusing. 1364. Line 247 The terminology used here is confusing, at best, and doesn't seem to have a useful purpose. The dichotomy "seismogenic sources" versus "tectonic sources" does not seem meaningful. Why are the former not simply called areal sources. since the other type -tectonic sources -are also seismogenic sources? Further, in the next line, "Seismic source input" is used: what is the difference between seismic source and seismogenic source? Finally, in Line 251. "areal seismic source" is used. This paragraph needs to be rewritten with consistent, conventional terminology. 1365. Line 266 There is some confusion as to the use of the term "Sonora Basin and Range. The SSC model uses the term .. Southern Basin and Range". Here. you seem to indicate that the "Sonora" component of this term is derived from the Lettis (2013) SSHAC2 report. This needs to be made clearer, and it would also help if it were made clear that this region is now referred to as the Southern Basin and Range. especially as the Mexican Highland Basin and Range is in Sonora. Mexico. 1366. Line 270 Baja is not the name of the Mexican State that occupies the northern hal1 of the Baja California peninsula. It is Baja California. If this term is in reference to that used in Lettis (2013}. please make that more clear by also referencing its current usage as Baja California in the SSC report. 1367. Lines 27 4-302 Some of the faults have "fault" in their listed name. whereas others do not. Is there a reason for this. and if so. please explain. Alternatively, make them consistent. 1368. Line 401 Please describe what is meant by the term "wider tail" in this context. 1369. Line 449 Here it states that the discussion will only address the 0.5 Hz SA sensitivities. whereas in the following text. the figures addressing the 5 Hz sensitivities are also cited (Lines 462-463. 466 and 477). Please clarify. 1370. Lines 451-452 Please be as specific as possible about what figure(s) are being referenced in the discussion Please also be more specific when describing the sensitivity cases. For example. the first sentence mentions "the first sensitivity analysis" and the second sentence mentions "these sensitivity cases, without indicating how these two descriptions are related. Since there are a lot of repetitive statements in the text describing the sensitivity analyses and/or sensitivity cases. this comment applies throughout the chapter: please make it clear what sensitivity analysis and/or case is being discussed at any given time and where that analvsis and/or case can be found on the tornado olot. 1371. Line 465 Section 7.4.1 does not include a discussion of additional epistemic uncertainty at large magnitude. Please provide the correct cross-reference. 1372. Line 468 Please add "types" between "two" and "common form models" in order to avoid confusion. 1373. Line 506 Please clarify what "Model 1" refers to on this line. 1374. Line 510 Please consider replacing the term "average" with the term "centrar so as not to imply that it is intended to represent the mean (average) hazard. 1375. Line 511 Figure 14.3-10a is cited on this line, but the discussion appears to refer to the case shown in Figure 14.3-9. Please check and correct as acoropriate. 1376. Line 517 Figure 14.3-9b is cited on this line, but the discussion appears to refer to the case shown in Figure 14-1 Oa. Please check and correct as acoropriate. 1377. Lines 594-595 Please add "types" between "two" and "common form models" in order to avoid confusion. 1378. Lines 609 and 617 Figures 14.3 (a and b} are cited. but in Line 605. it is stated these would not be discussed further. Please clarify. CHAPTER 15-Application Guidelines and Limitations 1379. Line 5 Please provide a cross reference to the adopted kappa value of 0.041 s. 1380. Lines 5-8 Please provide a cross reference to the section where evaluations are presented to support the claim that epistemic uncertainty in kappa is captured by the variation in high-frequency spectral shape within the SWUS GMC common-form models 1381. Lines 12-14 Please give the purpose for providing a representative Vs and density profile and what they can or should be used for. or delete this discussion from the report Without such a statement of purpose. it is ambiguous why these profiles are presented. For example, if they are provided for purposes of documenting what was used to estimate the host kappa values for the NGA-West2 GMPEs, then their discussion should be part of the appendix that discusses the host kappa value determination If they are meant to be representative of the site response predicted by the site terms in the NGA-West2 GMPEs. that has not been shown to be the case for these GMPES and is certainly not the case for the European or Japan GMPEs, which are likely represented by totally different Vs and density profiles. CHAPTER 16-References 1382. Please carefully review these references for completeness and accuracy and for consistency with the references provided in each chapter. February 24, 2015 Dr. Carola Di Alessandro SWUS Project Manager GeoPentech, Inc. 525 N. Cabrillo Park Drive, Suite 280 Santa Ana, CA 92701

Subject:

Participatory Peer Review Panel Closure Letter, Southwest United States Ground Motion Characterization Level 3 SSHAC Project

Dear Dr. Di Alessandro:

The Participatory Peer Review Panel (PPRP, also referred to herein as the "Panel") for the Southwest United States (SWUS) Ground Motion Characterization (GMC) Project is pleased to issue this PPRP Closure Letter. Herein we describe our participation in the SWUS GMC SSHAC Level 3 project and present our findings. Pursuant to the guidelines for a SSHAC Level 3 study (NUREG/CR-6372; NUREG-2117), the PPRP was engaged at all stages of the project, including review of the final Project Plan, Workshop agendas and participant lists; the planning of the evaluation and model integration activities; and review of the project documentation. Throughout the project, the Panel reviewed and provided regular feedback on both the process followed, and the technical assessments made, by the Technical Integrator (Tl) Team. By this letter the Panel documents the activities it has performed in the course of its review, its assessment of the process followed relative to SSHAC Level 3 expectations, and its assessment of the technical rationale underlying the GMC model. PPRP Activities in Support of the SWUS GMC Review In a SSHAC Level 3 study, the PPRP fulfills two roles. The first is that of technical review, in which the Panel ensures that the full range of data, models and methods are considered and that technical decisions and judgments are adequately justified and documented. The second is that of process review, under which the Panel ensures that the study maintains conformity with the SSHAC Level 3 guidelines. To fulfill these roles, the Panel requires adequate opportunities to gain understanding of the data being used, the analyses being performed, the Tl Team's evaluations of data and models, and the technical justifications for the Tl Team's model decisions. The table below summarizes the formal project activities in which the Panel participated. Fulfilling these roles also requires the Panel to provide regular feedback to the Tl Team during the course of the project. In addition to verbal feedback during Working Meetings and Workshops, the Panel provided written comments and recommendations at key stages of the project. Those written submittals are also noted in the table. 1 Date I PPRP Activity June 21, 2012 !Working Meeting #1 (Planning). All PPRP members attended. July 18, 2012 Working Meeting #2 (Planning}. All PPRP members attended. Auqust27, 2012 Kick-off MeetinQ. All PPRP members attended. September 17, 2012 PPRP submittal of written comments on the Project Plan. October 8, 2012 !Working Meeting #3. PPRP representatives attended as observers. November 3, 2012 IPPRP submittal of written comments on revised Project Plan. November 29, 2012 PPRP submittal of PPRP endorsement letter for Project Plan. December 10, 2012 WorkinQ MeetinQ #4. PPRP representatives attended as observers. February 11, 2a 13 Working Meeting #5. PPRP representatives attended as observers. March 19-21, 2013 #1: Critical issues and Data Needs. All PPRP members attended as bservers. The PPRP provided verbal feedback to the Tl Team at the end of ach day of the Workshop April 12, 2013 !Working Meeting #6. PPRP representatives attended as observers. April 21, 2013 PPRP submittal of written comments on Workshop #1. May 23, 2013 WorkinQ MeetinQ #7. PPRP representatives attended as observers. June 24, 2013 Working Meeting #8. PPRP representatives attended as observers. July 16, 2013 !Working Meeting #9. PPRP representatives attended as observers. August 21, 2013 !Working Meeting #10. PPRP representatives attended as observers. October 2, 2013 Working Meeting #11. PPRP representatives attended as observers. October 15, 2013 WorkinQ MeetinQ #12. PPRP representatives attended as observers. October 22-24, 2013 Workshop #2: Proponent Models and Alternative Interpretations. All PPRP members attended as observers. The PPRP provided verbal feedback to the Tl !Team at the end of each day of the Workshop. November 26, 2013 Working Meeting #13. PPRP representatives attended as observers. December 3, 2013 PPRP submittal of written comments on Workshop #2. January 2, 2014 Working Meeting #14. PPRP representatives attended as observers. January 28-29, 2014 Special Workinq MeetinQ. All PPRP members attended as observers. March 3, 2a14 Working Meeting #15. PPRP representatives attended as observers. March 10-12, 2014 #3: Preliminary GMC Models and Hazard Feedback. All PPRP embers attended as participants. The PPRP provided verbal feedback to the Team at the end of each day of the Workshop. March 24, 2014 !Working Meeting #16. PPRP representatives attended as observers. April 21, 2014 PPRP submittal of written comments on Workshop #3. May 14, 2014 PPRP Closure Pre-Briefinq. All PPRP members attended as participants. July 17-18, 2014 PPRP Closure Briefinq. All PPRP members attended as participants. December 13, 2014 Submittal No. 1 of PPRP written review comments on SWUS GMC Report: Comments on SWUS GMC Report Rev.a. Chapters 7, 10, 11, 12, 13, and l/\ppendices L, M, N, and R. December 16, 2014 PPRP and Tl Team, to discuss the PPRP written review omments, Submittal No. 1. January 5, 2015 Submittal No. 2 of PPRP written review comments on SWUS GMC Report: Comments on SWUS GMC Report Rev.a, Chapters 6, 8, 9, 14, and Appendices H, I, J, K, 0, and Q. January 7, 2015 [Teleconference, PPRP and Tl Team, to discuss the PPRP written review comments, Submittal No. 2. January 26, 2015 rTeleconference, PPRP and Tl Team, to discuss the main modifications introduced in SWUS GMC Report Draft Rev.1. February 9, 2015 [Teleconference, PPRP and Tl Team, to discuss observations from PPRP partial review of SWUS GMC Report Draft Rev.1. February 16, 2a15 !Teleconference, PPRP and Project Manager to discuss project completion schedule. February 20, 2a15 Submittal No. 3 of PPRP written review comments on SWUS GMC Report: Comments on SWUS GMC Report Draft Rev.1. 2 The PPRP finds that the level of ongoing review it was able to undertake, and the opportunities afforded the PPRP to provide feedback to the Tl Team, met the expectations for a SSHAC Level 3 study. Interactions with the Tl Team provided ample opportunity for the Panel to gain an understanding of the technical bases for the Tl Team's evaluations. The Panel also was given adequate opportunity to query the Tl Team, especially in Workshop #3 and in the Pre-Closure Briefing and Closure Briefing, to assess the justification provided for their model decisions. The Tl Team provided written responses to each formal PPRP submittal, and in nearly every case the PPRP and Tl Team subsequently discussed the comments and replies in a conference call or Working Meeting. SSHAC Process Review NUREG-2117 describes the goal of a SSHAC process as being "to carry out properly and document completely the activities of evaluation and integration, defined as: Evaluation: The consideration of the complete set of data, models and methods proposed by the larger technical community that are relevant to the hazard analysis. Integration: Representing the center, body, and range of technically defensible interpretations in light of the evaluation process (i.e., informed by the assessment of existing data, models, and methods)." During the Evaluation activities, the Tl Team considered new data, models and methods that have been introduced within the technical community since the previous seismic hazard studies were conducted for nuclear power plants in California and Arizona. The Team evaluated newly available ground motion databases, ground motion prediction equations (GMPEs), and ground motion simulation techniques. Notably, the Tl Team evaluated methods for the representation of non-Gaussian aleatory variability, as well as newly available methods for the visualization and characterization of epistemic uncertainty in ground motion prediction. The PPRP finds that the Tl Team's evaluation was consistent with the expectations for a SSHAC Level 3 study, and, apart from the specific reservation noted at the end of this section, was adequately documented. The Integration phase entails thoroughly documenting the technical bases for all elements of the GMC model, to provide assurance that the center, body and range of technically defensible interpretations have been captured. The Tl Team used a new statistical technique to generate a suite of representative models for median ground motion prediction that collectively represent the epistemic uncertainty in ground motion more broadly than do the published GMPEs alone. This technique is combined with a new method to select and weight the predictions of the expanded suite of models. The Tl Team's method for assigning weights is based on consideration of appropriate data 3 sets and numerical simulations, with adequate justification. The Tl Team's model for aleatory variability and weighting of alternative aleatory models is also adequately justified. The PPRP finds that the Tl Team's GMC model integration is consistent with the expectations of a SSHAC Level 3 project, and, apart from the specific reservation noted in the next paragraph, was adequately documented. The PPRP's reservation with respect to the documentation of the evaluation and integration phases of the study is based on the Tl Team's inability to produce a final report based on the last set of comments from the Panel (Submittal No. 3, February 20, 2015) that were intended to improve the completeness and clarity of the documentation. The Tl Team was unable to revise the report in time for this letter to be issued in order to meet contractual obligations to provide written documentation to the utilities. The Tl Team did provide written responses to the Panel's comments and assured the Panel in writing that the final version of the report would take these comments into account. SSHAC Technical Review NUREG-2117 describes the PPRP's technical review role as follows: "The PPRP fulfills two parallel roles, the first being technical review. This means that the PPRP is charged with ensuring that the full range of data, models, and methods have been duly considered in the assessment and also that all technical decisions are adequately justified and documented. The responsibility of the PPRP is to provide clear and timely feedback to the Tl/TFI and project manager to ensure that any technical or process deficiencies are identified at the earliest possible stage so that they can be corrected. More commonly, the PPRP provides its perspectives and advice regarding the manner in which ongoing activities can be improved or carried out more effectively. In terms of technical review, a key responsibility of the PPRP is to highlight any data, models or proponents that have not been considered. Beyond completeness, it is not within the remit of the PPRP to judge the weighting of the logic-trees in detail but rather to judge the justification provided for the models included or excluded, and for the weights applied to the logic-tree branches." As summarized in the table above, the PPRP reviewed the Tl Team's evaluations of data, models and methods on multiple occasions, and through various means, including written communications, in-person meetings, teleconferences, and review of the project report. The Panel was given adequate opportunity to question the Tl Team concerning details of their analysis, and provided feedback verbally and in writing. The Tl Team was responsive to the technical input from the Panel. The Tl Team's responses included evaluating additional data sets suggested by the Panel, undertaking additional 4 analyses to address specific Panel technical questions or concerns, and examining and assessing alternative technical approaches suggested by the Panel. The PPRP therefore concludes that it has been afforded an adequate basis for technical assessment of the Tl Team's evaluations and model integration and finds that the project meets technical expectations for a SSHAC Level 3 study. Conclusion On the basis of its review of the SWUS GMC project, the PPRP finds that the project meets, with respect to both process and technical standards, the expectations for a SSHAC Level 3 study, with the reservation cited above. That reservation relates only to completeness of the documentation, which the Tl Team has assured in writing will be rectified in the final report. Sincerely, Steven M. Day Chair, PPRP Brian Chiou Member, PPRP Kenneth W. Campbell Member, PPRP . /""' ' -...-'°1 . . . I , *'JI, I / .* *

• f-/i t. ..,_,:.(, 1.(__ 1 i. .1 .* s-:> -// /-... * Thomas K. Rockwell Member, PPRP 5 From: Steven Day <sday@mail.sdsu.edu>

Subject:

non-mandatory comments Date: Monday, March 09, 2015 8:03 AM To: Carola DiAlessandro <carola dialessandro@geopentech.com> Cc: Steven Day <sday@mail.sdsu.edu>, Kenneth Campbell <ken.w.campbell@comcast.net>, Brian Chiou <brian chiou@comcast.net>, Thomas Rockwell <trockwell@mail.sdsu.edu> Attachments: Non-mandatory comments, BC.docx (13 KB) Hi, Carola. Please find attached some non-mandatory comments on SWUS report Rev2 .These are offered by PPRP members acting individually, and I am sending them to you informally in case they might aid your team in its editorial work. There is no obligation on your part to consider them. Steve March 10, 2015 Dr. Carola Di Alessandro SWUS Project Manager GeoPentech, Inc. 525 N. Cabrillo Park Drive, Suite 280 Santa Ana, CA 92701

Subject:

Participatory Peer Review Panel Closure Letter, Southwest United States Ground Motion Characterization Level 3 SSHAC Project

Dear Dr. Di Alessandro:

The Participatory Peer Review Panel (PPRP, also referred to herein as the "Panel") for the Southwest United States (SWUS) Ground Motion Characterization (GMC) Project is pleased to issue this PPRP Closure Letter. Herein we describe our participation in the SWUS GMC SSHAC Level 3 project and present our findings. Pursuant to the guidelines for a SSHAC Level 3 study (NUREG/CR-6372; NUREG-2117), the PPRP was engaged at all stages of the project, including review of the final Project Plan, Workshop agendas and participant lists; the planning of the evaluation and model integration activities; and review of the project documentation. Throughout the project, the Panel reviewed and provided regular feedback on both the process followed, and the technical assessments made, by the Technical Integrator (Tl) Team. By this letter the Panel documents the activities it has performed in the course of its review, its assessment of the process followed relative to SSHAC Level 3 expectations, and its assessment of the technical rationale underlying the GMC model. The PPRP issued a previous letter dated February 24, 2015. In that letter, the Panel noted that there were limitations in the completeness and clarity of the project documentation. Those limitations were noted as exceptions to the Panel's finding that the project successfully met SSHAC Level 3 expectations. Since that time, the Tl Team has produced a final report, designated Rev2, addressing the final set of comments from the Panel (PPRP Submittal No. 3, February 20, 2015). The Panel has reviewed Rev2 (including a short addendum supplied to the PPRP in draft form on March 9 which the Tl Team has assured in writing will be incorporated in the final version) and finds that all material concerns have been adequately addressed and are now closed, apart from one remaining exception that will be described at the end of the SSHAC Process Review section below. Two GMC models were developed for application to Diablo Canyon Power Plant (DCPP) and Palo Verde Nuclear Generating Station (PVNGS), respectively. The exception applies only to the GMC model for DCPP, and is not relevant to the case of PVNGS. 1 PPRP Activities in Support of the SWUS GMC Review In a SSHAC Level 3 study, the PPRP fulfills two roles. The first is that of technical review, in which the Panel ensures that the full range of data, models and methods are considered and that technical decisions and judgments are adequately justified and documented. The second is that of process review, under which the Panel ensures that the study maintains conformity with the SSHAC Level 3 guidelines. To fulfill these roles, the Panel requires adequate opportunities to gain understanding of the data being used, the analyses being performed, the Tl Team's evaluations of data and models, and the technical justifications for the Tl Team's model decisions. The table below summarizes the formal project activities in which the Panel participated. Fulfilling these roles also requires the Panel to provide regular feedback to the Tl Team during the course of the project. In addition to verbal feedback during Working Meetings and Workshops, the Panel provided written comments and recommendations at key stages of the project. Those written submittals are also noted in the table. Date PPRP Activity June 21. 2012 Working Meeting #1 (Planning). All PPRP members attended. July 18, 2012 Working Meeting #2 (Planning). All PPRP members attended. August27, 2012 Kick-off Meeting. All PPRP members attended. September 17, 2012 PPRP submittal of written comments on the Project Plan. October 8, 2012 Workinq Meetinq #3. PPRP representatives attended as observers. November 3, 2012 PPRP submittal of written comments on revised Project Plan. November 29, 2012 IPPRP submittal of PPRP endorsement letter for Project Plan. December 10, 2012 Working Meeting #4. PPRP representatives attended as observers. February 11, 2013 WorkinQ MeetinQ #5. PPRP representatives attended as observers. March 19-21. 2013 Workshop #1: Critical issues and Data Needs. All PPRP members attended as observers. The PPRP provided verbal feedback to the Tl Team at the end of each day of the Workshop April 12, 2013 Working Meeting #6. PPRP representatives attended as observers. April 21, 2013 PPRP submittal of written comments on Workshop #1. May 23, 2013 Working Meeting #7. PPRP representatives attended as observers. June 24, 2013 WorkinQ MeetinQ #8. PPRP representatives attended as observers. July 16, 2013 Working Meeting #9. PPRP representatives attended as observers. August 21, 2013 Working Meeting #10. PPRP representatives attended as observers. October 2, 2013 !Working Meeting #11. PPRP representatives attended as observers. October 15, 2013 Working Meeting #12. PPRP representatives attended as observers. October 22-24, 2013 Workshop #2: Proponent Models and Alternative Interpretations. All PPRP members attended as observers. The PPRP provided verbal feedback to the Tl [Team at the end of each dav of the Workshop. November 26, 2013 Working Meeting #13. PPRP representatives attended as observers. December 3, 2013 PPRP submittal of written comments on Workshop #2. January 2, 2014 Working Meeting #14. PPRP representatives attended as observers. January 28-29, 2014 Special Working Meeting. All PPRP members attended as observers. March 3, 2014 WorkinQ MeetinQ #15. PPRP representatives attended as observers. March 10-12, 2014 Workshop #3: Preliminary GMC Models and Hazard Feedback. All PPRP members attended as participants. The PPRP provided verbal feedback to the rTI Team at the end of each day of the Workshop. March 24, 2014 Working Meeting #16. PPRP representatives attended as observers. April 21, 2014 PPRP submittal of written comments on Workshop #3. 2 May 14, 2014 IPPRP Closure Pre-Briefing. All PPRP members attended as participants. July 17-18, 2014 PPRP Closure Briefinq. All PPRP members attended as participants. December 13, 2014 Submittal No. 1 of PPRP written review comments on SWUS GMC Report: Comments on SWUS GMC Report Rev .0, Chapters 7, 10, 11, 12, 13, and L, M, N, and R. December 16. 2014 rTeleconference, PPRP and Tl Team, to discuss the PPRP written review comments, Submittal No. 1. January 5, 2015 Submittal No. 2 of PPRP written review comments on SWUS GMC Report: Comments on SWUS GMC Report Rev.O. Chapters 6, 8, 9, 14, and Appendices H, I, J, K, 0, and Q. January 7, 2015 rTeleconference, PPRP and Tl Team, to discuss the PPRP written review comments. Submittal No. 2. January 26, 2015 !Teleconference, PPRP and Tl Team, to discuss the main modifications introduced in SWUS GMC Report Draft Rev.1. February 9, 2015 rTeleconference, PPRP and Tl Team, to discuss observations from PPRP partial review of SWUS GMC Report Draft Rev.1. February 16, 2015 rTeleconference, PPRP and Project Manager to discuss project completion schedule. February 20, 2015 Submittal No. 3 of PPRP written review comments on SWUS GMC Report: Comments on SWUS GMC Report Draft Rev.1. February 24. 2015 Submittal of Closure Letter based on Draft Rev.1 The PPRP finds that the level of ongoing review it was able to undertake, and the opportunities afforded the PPRP to provide feedback to the Tl Team, met the expectations for a SSHAC Level 3 study. Interactions with the Tl Team provided ample opportunity for the Panel to gain an understanding of the technical bases for the Tl Team's evaluations. The Panel also was given adequate opportunity to query the Tl Team, especially in Workshop #3 and in the Pre-Closure Briefing and Closure Briefing, to assess the justification provided for their model decisions. The Tl Team provided written responses to each formal PPRP submittal, and in nearly every case the PPRP and Tl Team subsequently discussed the comments and replies in a conference call or Working Meeting. SSHAC Process Review NUREG-2117 describes the goal of a SSHAC process as being "to carry out properly and document completely the activities of evaluation and integration, defined as: Evaluation: The consideration of the complete set of data, models and methods proposed by the larger technical community that are relevant to the hazard analysis. Integration: Representing the center, body, and range of technically defensible interpretations in light of the evaluation process (i.e., informed by the assessment of existing data, models, and methods)." During the Evaluation activities, the Tl T earn considered new data, models and methods that have been introduced within the technical community since the previous seismic hazard studies were conducted for nuclear power plants in California and Arizona. The 3 Team evaluated newly available ground motion databases, ground motion prediction equations (GMPEs), and ground motion simulation techniques. Notably, the Tl Team evaluated methods for the representation of non-Gaussian aleatory variability, as well as newly available methods for the visualization and characterization of epistemic uncertainty in ground motion prediction. The PPRP finds that the Tl Team's evaluation and the documentation thereof are consistent with the expectations for a SSHAC Level 3 study, apart from the specific reservation noted at the end of this section. The Integration phase entails thoroughly documenting the technical bases for all elements of the GMC model, to provide assurance that the center, body and range of technically defensible interpretations have been captured. The Tl Team used a new statistical technique to generate a suite of representative models for median ground motion prediction that collectively represent the epistemic uncertainty in ground motion more broadly than do the published GMPEs alone. This technique is combined with a new method to select and weight the predictions of the expanded suite of models. The Tl Team's method for assigning weights is based on consideration of appropriate data sets and numerical simulations, with adequate justification. The Tl Team's model for aleatory variability and weighting of alternative aleatory models is also adequately justified. The PPRP finds that the Tl Team's GMC model integration and the documentation thereof are consistent with the expectations of a SSHAC Level 3 project, apart from the specific reservation noted in the next paragraph. The Panel finds that the Tl Team's evaluation of directivity models has limitations. The Tl Team make use of a simplified directivity model to save computational time, and the final report adequately describes that model, how it is used, and some of its limitations. However, because the simplified model is unpublished, it is also necessary for the Tl Team to document that the simplified model is appropriate for the purpose for which it is applied, in the sense that it gives results that are essentially consistent with the published and peer-reviewed model that it is intended to approximate. The final report (in the March 9 addendum) documents the performance of the simplified model through comparison with results from a hazard calculation that uses the full, published directivity model. At hazard levels of 10-4 and above, the full model calculation confirms the conclusion obtained using the simplified model. At hazard levels below 10-4, however, the difference in calculated hazard between the full model and the simplified model increases with decreasing hazard level. This increasing trend has not been satisfactorily explained, has not been explored beyond the single fault case provided in the March 9 addendum, and has not been quantified in terms of impact on equal-hazard spectra at hazard levels of 10-5 and lower. Because the key rationale for the zero weighting of the directivity branch in the GMC model for periods longer than 0.5 s (the period range where the directivity effect applies) is the weak sensitivity of hazard to the directivity effect calculated using the simplified model, the PPRP finds that this weighting lacks sufficient technical justification. 4 SSHAC Technical Review NUREG-2117 describes the PPRP's technical review role as follows: "The PPRP fulfills two parallel roles, the first being technical review. This means that the PPRP is charged with ensuring that the full range of data, models, and methods have been duly considered in the assessment and also that all technical decisions are adequately justified and documented. The responsibility of the PPRP is to provide clear and timely feedback to the Tl/TFI and project manager to ensure that any technical or process deficiencies are identified at the earliest possible stage so that they can be corrected. More commonly, the PPRP provides its perspectives and advice regarding the manner in which ongoing activities can be improved or carried out more effectively. In terms of technical review, a key responsibility of the PPRP is to highlight any data, models or proponents that have not been considered. Beyond completeness, it is not within the remit of the PPRP to judge the weighting of the logic-trees in detail but rather to judge the justification provided for the models included or excluded, and for the weights applied to the logic-tree branches." As summarized in the table above, the PPRP reviewed the Tl Team's evaluations of data, models and methods on multiple occasions, and through various means, including written communications, in-person meetings, teleconferences, and review of the project report. The Panel was given adequate opportunity to question the Tl Team concerning details of their analysis, and provided feedback verbally and in writing. The Tl Team was responsive to the technical input from the Panel. The Tl Team's responses included evaluating additional data sets suggested by the Panel, undertaking additional analyses to address specific Panel technical questions or concerns, and examining and assessing alternative technical approaches suggested by the Panel. The PPRP therefore concludes that it has been afforded an adequate basis for technical assessment of the Tl Team's evaluations and model integration. As noted above in the final paragraph of the SSHAC Process Review section, the evaluation of directivity effects has been inadequate and may constitute a technical limitation of the study. Apart from that reservation, the PPRP finds that the project meets technical expectations for a SSHAC Level 3 study. Conclusion On the basis of its review of the SWUS GMC project, the PPRP finds that the project meets, with respect to both process and technical standards, the expectations for a 5 SSHAC Level 3 study, with the reservation cited above. That reservation pertains specifically to application of the directivity component of the GMC model to the DCPP site. Sincerely, Steven M. Day Chair, PPRP Brian Chiou Member, PPRP Kenneth W. Campbell Member, PPRP * Thomas K. Rockwell Member, PPRP 6 SWUS GMC SSHAC -PPRP INTERACTION Participatory Peer Review Panel (PPRP) Letters PPRP-la) Letter dated September 17, 2012, to Mr. Barneich and Dr. Abrahamson: Draft Comments on the SWUS GMC Project Plan Results of the Participatory Peer Review Panel (PPRP} review of the draft Project Plan (draft dated August 2, 2012} for the Southwestern U.S. Ground Motion Characterization (SWUS GMC) SSHAC Level 3 study. PPRP-lb) Letter dated November 3, 2012, to Dr. Di Alessandro: Requested Clarifications to the SWUS GMC Project Plan Request for clarifications by the Participatory Peer Review Panel (PPRP) relating to the updated version of the draft Project Plan (draft dated October 3, 2012} for the Southwestern U.S. Ground Motion Characterization (SWUS GMC) SSHAC Level 3 study. PPRP-lc) Letter dated November 29, 2012, to Dr. Di Alessandro: Participatory Peer Review Panel Review of the SWUS GMC Project Plan Results of the Participatory Peer Review Panel (PPRP) review of the consolidated Project Plan (dated November 12, 2012) for the Southwestern U.S. Ground Motion Characterization (SWUS GMC} SSHAC Level 3 study. PPRP-2) Letter dated April 21, 2013, to Dr. Di Alessandro: Participatory Peer Review Panel Comments on Workshop No. l Participatory Peer Review Panel (PPRP) comments on the SWUS GMC SSHAC Level 3 Workshop #1 (Significant Issues and Available Data). PPRP-3) Letter dated December 3, 2013, to Dr. Di Alessandro: Participatory Peer Review Panel Comments on Workshop No. 2 Participatory Peer Review Panel (PPRP) comments on the SWUS GMC SSHAC Level 3 Workshop #2 (Proponent Models and Alternative Interpretations). PPRP-4) Letter dated April 21, 2014, to Dr. Di Alessandro: Participatory Peer Review Panel Comments on Workshop No. 3 Participatory Peer Review Panel (PPRP) comments on the SWUS GMC SSHAC Level 3 Workshop #3 (Pre I imi nary G MC Models and Haza rd Feed back}. Page 1of4 SWUS GMC SSHAC -PPRP INTERACTION PP RP-Sa) Letter dated December 13, 2014, to Dr. Di Alessandro: Participatory Peer Review Panel Letter No. 1: Rev.O Report, Southwest United States Ground Motion Characterization Level 3 SSHAC Project Participatory Peer Review Panel (PPRP} comments and recommendations on the SWUS Project Report, Rev.a (Chapters 7, 10, 11, 12, and 13, and Appendices L, M, N, and R). PPRP-Sb) Letter dated January 5, 2015, to Dr. Di Alessandro: Participatory Peer Review Panel Letter No. 2: Rev.O Report, Southwest United States Ground Motion Characterization Level 3 SSHAC Project Participatory Peer Review Panel (PPRP) comments and recommendations on the SWUS Project Report, Rev.a (Chapters 6, 8, 9, and 14, and Appendices H, I, J, K, O, and Q). PPRP-Sc) Email dated February 9, 2015, to Dr. Abrahamson and Dr. Di Alessandro: Preliminary PPRP comments on Draft Rev.1 SWUS GMC Report (PPRP Informal Communication) Informal transmittal of unedited preliminary comments from Dr. Day and Dr. Rockwell. Attachment PPR P-5 b-A: Preliminary comments from Dr. Day. Attachment PPRP-Sb*B: Preliminary comments from Dr. Rockwell. Attachment PPRP-Sb-C: Suggested minor editorial corrections from Dr. Rockwell. PPRP-5d) Letter dated February 20, 2015, to Dr. Di Alessandro: Participatory Peer Review Panel Letter No. 3: Draft Rev.1 Report, Southwest United States Ground Motion Characterization Level 3 SSHAC Project Provides Participatory Peer Review Panel (PPRP} consolidated comments and rec om mendatio ns for the SWUS Project Report, Draft Rev.1 (Chapters 1 th rough 16}. PPRP*6) Letter dated February 24, 2015, to Dr. Di Alessandro: Participatory Peer Review Panel Closure Letter, Southwest United States Ground Motion Characterization Level 3 SSHAC Project Participatory Peer Review Panel (PPRP) Closure Letter regarding the SWUS GMC SSHAC Level 3 Report, Rev. 1. PPRP*7) Email dated March 9, 2015, to Dr. Di Alessandro: Non-mandatory PPRP comments on Draft Rev. 2 SWUS GMC Report (PPRP Informal Communication) Informal transmittal of non-mandatory comments from Dr. Chiou. Attachment PPRP-7: Non-mandatory comments from Dr. Chiou. PPRP-8) Letter dated March 10, 2015, to Dr. Di Alessandro: Participatory Peer Review Panel Closure Letter, Southwest United States Ground Motion Characterization Level 3 SSHAC Project Participatory Peer Review Panel (PPRP} Closure Letter regarding the SWUS GMC SSHAC Level 3 Report, Rev. 2. Page 2 of 4 SWUS GMC SSHAC -PPRP INTERACTION Technical Integration (Tl) Team and Project Manager (PM) Response to PPRP Letters Tl_Team_PM-1) Email dated November 13, 2012, to Dr. Day: Tl Team and PM responses to PPRP request for clarification on Draft Project Plan, dated November 3, 2012 Participatory Peer Review Panel (PPRP} questions provided with their November 3, 2012 letter. Replies are provided as digital sticky notes superimposed on the PPRP November 3, 2012 letter. Attachment Tl Team PM-1: Responses to PPRP request for clarification. Tl_Team_PM-2) letter dated May S, 2013, to Dr. Day: Tl Team and PM responses to Participatory Peer Review Panel Comments on Workshop No. 1, dated April 21, 2013 Provides the Tl Team and Project Manager's responses to the Participatory Peer Review Panel (PPRP} comments on the SWUS GMC SSHAC Level 3 Workshop #1 (Significant Issues and Available Data). Tl_Team_PM-3) Letter dated January 6, 2014, to Dr. Day: Tl Team and PM responses to Participatory Peer Review Panel Comments on Workshop No. 2, dated December 3, 2013 Provides the Tl Team and Project Manager's responses to the Participatory Peer Review Panel (PPRP} comments on the SWUS GMC SSHAC Level 3 Workshop #2 (Proponent Models and Alternative Interpretations). Tl_Team_PM-4) letter dated May 23, 2014, to Dr. Day: Tl Team and PM responses to Participatory Peer Review Panel Comments on Workshop No. 3, dated April 21, 2014 Provides the Tl Team and Project Manager's responses to the Participatory Peer Review Panel (PPRP} comments on the SWUS GMC SSHAC Level 3 Workshop #3 (Preliminary GMC Models and Hazard Feedback). Other Technical Integration (Tl) Team and Project Manager (PM) Relevant Documentation in Response to PPRP Comments Other-1) Email dated July 28, 2014, to Dr. Day, Dr. Campbell, Dr. Chiou, and Dr. Rockwell: Follow up after the PPRP Briefing Meeting, occurring on July 17-18, 1014 Exhorts further comments by the PPRP after the Briefing Meeting held on July 17-18, 2015 at UC Berkeley, in addition to what was collected in the Meeting Notes. Attachment Other-1: Summary of discussions and PPRP verbal feedback obtained during the July 17-18, 2015 Briefing Meeting. Page 3 of 4 SWUS GMC SSHAC -PPRP INTERACTION Other-2) Letter dated February 23, 2015, to Dr. Day: Replies to Tier 1 and Tier Z comments contained in the Participatory Peer Review Panel Letter No. 3, dated February ZO, 2015 Responses to the Tier 1 comments transmitted via PPRP Letter No. 3. Provides excerpts of the Rev.1 report showing where the comments were accommodated (via comment dialog boxes). It also provides resolution to Tier 2 comments, including summary of the changes applied to the Rev. 1 report (where applicable}. Other-3) Email dated March 9, 2015, to Dr. Day, Dr. Campbell, Dr. Chiou, and Dr. Rockwell: Evaluation of Alternative Directivity Models for DCPP Attachment Other-3: Stand-alone write-up provided by Dr. Abrahamson on March 9, 2015, addressing the PPR P's request to augment the Tl Team's evaluation of the alternative directivity models for application to DCPP. Other-4) Internal project records: Consolidated Comment-Resolution log in response to Participatory Peer Review Panel Letters No. l, Z and 3. Attachment Other-4-A: Consolidated Comment-Resolution log in response to Participatory Peer Review Panel Letter No. 1. The modifications in the text were incorporated in the SWUS GMC Rev.1 and Rev.2 reports, unless diversely stated. Attachment Other-4-B: Consolidated Comment-Resolution log in response to Participatory Peer Review Panel Letter No. 2. The modifications in the text were incorporated in the SWUS GMC Rev.1 and Rev.2 reports, unless diversely stated. Attachment Other-4-C: Con so I idated Comment-Resolution log in response to m a ndato ry ed itoria I comments from Tom Rockwel I dated February 9, 2015. Attachment Other-4-0: Consolidated Comment-Resolution log in response to Participatory Peer Review Panel Letter No. 3. The modifications in the text were incorporated in the SWUS GMC Rev.1 and Rev.2 reports, unless diversely stated. Page 4 of 4 From: Carola DiAlessandro Sent: Tuesday, November 13, 2012 2:47 PM To: Steve Day Cc: John Barneich; norman abrahamson

Subject:

Responses to PPRP Comments and resulting Rev2 Project Plan

Dear Steve,

We have gone over the PPRP comments (PPRP Project Plan Letter dated 11/3/2012) and have accommodated or responded to them as appropriate. We are attaching two versions for Rev2 of the Project Plan. One includes tracked changes and comments referring to which question or minor editorial note is accommodated through the revision. Another document is a clean version of the same Project Plan without comments and change tracking. We are also attaching a copy of your letter with sticky notes indicating a cross reference as to what page each of your comments is accommodated by the plan modifications (Rev 2 Plan attached); such sticky notes address as well PPRP questions or comments in those cases where a change to the plan did not occur. We hope that our modified Project Plan and enclosed responses will satisfy the PPRP panel. Should that be the case, we would appreciate receiving a reviewed letter as appropriate. Thanks, --Carola, John and Norm Carola Di Alessandro, Ph.D. Project Managerfor the SWUS GMC SSHAC GeoPentech, Inc. 525 N. Cabrillo Park Drive, Suite 280 Santa Ana. CA 9270 I Mobile: 510-491-6713 Fax: 714-796-9191 Office Phone: 714-796-9100 Email: carola dialessandro(t1)geopentech.com May 5, 2013 Sleven M. Day Chair, Participatory Peer Review Panel Department of Geological Sciences San Diego State University 5500 Campanile Drive San Diego, California 92182

Dear Prof Day:

The Tl Team and PM appreciate the valuable comments and suggestions received from the Participatory Peer Review Panel (PPRP), both during the Workshop No. I execution and in Lheir fonnal letter commentary daled April 21, 2013. The present document serves to provide written responses to specific comments, suggestions, or recommendations that the PPRP identified (by underlining). 1. Site Kappa and Single-Station Sigma Terminology Several resource experls presenled very interesting and insighlful information on Lhe data needed to estimale the site attenuation parameler kappa and the ground motion standard deviation parameter single-site sigma. However, this material is quite technical and some of it is quite new. Not all participants and observers seemed to have a shared understanding of the terminologies being employed or how the estimated quantities can be applied in a self-consistent manner at each of the nuclear power plant sites where they will be used. Our concern comes partly from the lack of probing questions of the kappa and single-site sigma resource experts from the Tl Team, partly from a lack of significant questions from the audience, and partly from questions expressed by members of the PPRP. Therefore. the PPRP suggests that the Tl Team write White Papers. i.e .. authoritative technical notes. on site kappa and single-station sigma. respectively, that define the tenns. indicate how they are going to be estimated. and how they are to be used in the seismic hazard analysis of each of the NPPs. These documents would provide a common language and reference frame for future discussions and help allay concerns about possible double counting or other inconsislencies in these two paramelers. We agree. Our plan is to coordinate the preparation of the requested White Papers with the effort already initiated by Dr. Linda Al-Atik (a member of the Tl Team Support group) for the Hanford site SSHAC project In this way, in addition to providing a common understanding of the issues and terminology for the SWUS GMC project, we will address consistency with the other ongoing SSllAC projects conducted in the Western US region.

2. Splay Faull Modeling The workshop included some discussion of dynamic rupture modeling of splay faulting, especially models leading to possible concurrent rupture of the Hosgri and Shoreline faults. Our understanding is that SCEC has been tasked with pcrfom1ing such modeling. We arc concerned that this effort may not be as well interfaced with the relevant SSllAC projects (the DCPP and SONGS SSC studies and the SWUS GMC study) as it could be. In particular, the occurrence and extent of concurrent rupture on a splay depends quite strongly on the orientation of the maximum principal stress direction. It is likely also to be sensitive to rupture velocity. The SCEC team tasked for this work has been principally focused on canonical test problems for the purpose of code verification; it should not simply be assumed that the SCEC group has sufficient expertise and experience in the specific rupture dynamics questions being posed by the SSHAC projects to operate independently. The presentation at the workshop did not suggest that the SCEC team recognizes the importance of the principal stress orientations, nor the importance of exploring conditions conducive to a range of rupture velocities. W c recommend that the SWUS GMC project and the other relevant SSHAC projects devise a plan to provide ongoing guidance and feedback to the SCEC modeling team. We note that SCEC has not been tasked with conducting dynamic rupture calculation for splay faulting for SWUS GMC. The activities at SCEC have focused only on code verification (i.e. to make sure codes arc working as intended) for splay fault geometrics that arc relevant to DCPP and SONGS. Based on the results of the verification, we will identify potential groups for conducting dynamic rupture simulations for SWUS GMC Project. However, the decision on the extent of use of dynamic rupture simulations has not yet been made. Our plan is for the TI Team (in particular Prof. Doug Dreger) to work in close contact with the SCEC dynamic rupture verification coordinator (Dr. Ruth Harris of USGS) to understand the role played by stress orientation and rupture velocity in the validation exercise. In addition, we will recommend that representatives from the SSC Teams meet with Ruth Harris to discuss the use of dynamic ruptures for constraining characteristics and frequencies of splay fault ruptures. This infonnation can be used to constrain the source characterization for splay faulting. 3. DCPP-SSC inte1:face issue: Slab Earthquakes During the workshop, the possibility of earthquakes within a relic subducted slab beneath DCPP was broached during the presentation overviewing the DCPP SSC project. To our knowledge, this possibility of slab sources had not been mentioned at previous DCPP SSC workshops, and from the discussion at the workshop, it was not clear which project takes responsibility for assessing its technical defensibility and implications. Slab earthquakes are known to excite ground motion with systematically distinct characteristics relative to crustal sources. We recommend that the two projects clarify the lines of responsibility and establish effective communication on this subject so that the TI Team is not taken by surprise if slab events are characterized in the DCPP SSC. We agree and will engage the DCPP SSC Project Team to address the potential for slab earthquakes in the DCPP region. The final decision for inclusion or exclusion of slab earthquakes lies with the SCC Team but information from ground motion experts that maybe relevant to the SSC Team evaluation will be provided by the SWUS GMC project. 4. DCPP-SSC and SONGS-SSC inte1.face issue: Maximum depth of rupture in crustal earthquakes During the DCPP SSC overview presented at the workshop, the possibility was raised of deep cmstal earthquakes, i.e., greater than 15-20 km deep, on some cmstal faults in California. The SWUS GMC TI Team seemed unaware that this was a possibility in the DCPP SSC project and it was not clear to us which project takes responsibility for the technical assessment of deep cmstal earthquake modeling. We recommend that the two projects clarify ownership of the depth-ot:. faulting problem and begin to communicate effectively and regularly about the status and implications of those ideas. We agree. Information on the maximum depth of mpture may be available from source inversions commonly used in ground motion studies that arc not yet being considered by the DCPP and SONGS SSC TI Teams. Ensuring that this interface issue is addressed is the responsibility of the Project Technical Integrators (PTls) for the SSC and GMC efforts for each site. We will provide examples of ground motion inversion studies to demonstrate the range of depth-of-ruptures implied by these studies so that the SSC TI Teams arc fully informed. The final decision for the distribution of rupture depths lies with the individual SSC Teams. 5. Attenuation for Palo Verde The attenuation of ground motion between distant earthquakes and PVNPS may be quite strongly dependent upon the source location and might not be well represented by a single function of distance. The TI Team clearly recognizes this likelihood and has taken it into consideration in their plan to empirically estimate attenuation from distant sources to PVNPS using existing recordings from relevant source regions. We consider this a sound approach. However, the PPRP would suggest that the empirical approach be carefully applied in the light of a geological understanding of both the source and path regions (for example, it might be observed that paths crossing the Salton Trough are highly attenuative and geologic understanding might dictate that the same empirical correction not be applied to nearby sources that do not cross thal province). We agree. The SWUS GMC TI Team will consider different regions (one being the Salton Trough region) when evaluating the residuals to derive empirical correction factors applicable to PYNGS. In order to preserve the statistical robustness of the analysis, we are expanding our ground motion dataset so to include more earthquakes generaled in central California (up to 400 km from the Arizona border) and recorded by stations in Arizona located up to I 00 km away from PYNGS, but still within the Sonoran Basin and Range zone as prescribed/mapped by the associated SSC effort. These additional earthquakes will allow us to evaluate Lhe need for diflerent path effecls through the Salton Trough versus other path effects. 6. Hand-r?[f to Site-Spec(fic Site-Response Analysis Team The GMC Tl Team is proposing to characterize ground motions for a common reference rock condition with Ys30 = 760 mis and to adjust the base case GMC model to incorporate utility-specific differences in site characteristics and modeling approach. We understand that each utility will adjust the resulting rock hazards to the local site condition at each NPP site when deriving the Consistent Ground Motion Response Spectra (GMRS). The TI Team have acknowledged need for interaction between these two efforts and emphasized the importance of proper handoff of the GMC model to the team responsible for specific site-response analysis. Slill we want to further emphasize it here by cautioning that lack of clarity and precision in the communication between the GMC TI Team and the site response analysis team may make both vulnerable to misunderstandings and claims of inconsistency or double counting of effects. We recommend that the TI Team and the individual site projects collaborate to generate as soon as possible a reference document that describes the respective adjustments and procedures to be used at each site and that explains the technical rationale in each case. As with the documents on kappa and single-site sigma recommended in Item I above, such a document would serve to guide future discussions, prevent misunderstandings, and ensure that no relevant data or models arc neglected due to uncertainties about which project is responsible. We agree. Although site response is not part of the deliverable for SWUS GMC, the approaches being used for site response at the three NPP sites need to be underslood and clearly documented to ensure a consistent interface between the base case ground motion and site response. The final decision on site response approaches lies with the individual NPP siles.

We plan on issuing a White Paper describing the site-response approaches being used at each of the Lhree sites; this document will include the Lechnical base for the seleclion of the reference rock conditions. We hope this letter clarifies the queslions and comments stated in the April 21, 2013 PPRP Commentary Letter. We wish to express our gratitude to the PPRP again for their efforts and cooperation, and for making this project a success. Sincerely, .. . ,..., l:;j_? . _j ** ,

• 0 . .cc0-.,*(...o Carola Di Alessandro, SWUS GMC Project Manager CC: PPRP Panel, TI Team, PTis Norman A. Abrahamson, SWUS GMC Tl Team Lead January 6, 2014 Steven M. Day Chair, Participatory Peer Review Panel Department of Geological Sciences San Diego State University 5500 Campanile Drive San Diego, California 92182

Dear Prof. Day:

The Tl Team and PM appreciate the valuable comments and suggestions received from the Participatory Peer Review Panel (PPRP}, both during the Workshop No. 2 execution and in their formal letter commentary dated December 3, 2013. The present document serves to provide written responses to specific comments, suggestions, or recommendations that the PPRP identified (by underlining). 1. Balanced participation by the Tl team members. During the first two days of the workshop, a disproportionate amount of the interrogation of the proponent experts was done by the Tl lead, with some contributions from other senior members of the team. Other members were not significantly engaged in the discussions on those days. This imbalance is a concern, because SSHAC guidelines for a Level 3 study explicitly call for Tl team members to be prepared to voice independent views and technical challenges. The PPRP was pleased to see more balanced participation on the third day and recommends that the Tl team take concrete steps to ensure that this progress continues during the remainder of the project. The importance of full Tl team participation is emphasized in the NRC SSHAC guidance document (NUREG-2117), which states, for example (p. 36) "membership in the Tl team automatically implies sharing the ownership of the component models developed by that team" and (p. 38}, while discussing the distinction of a Level 3 SSHAC study in contrast to lower level SSHAC studies, "The Tl must now be a team rather than an individual or small group, ... at Level 3, this is essential both because no individual has the breadth of expertise required and because of the necessity for technical challenge and defence among the evaluators." REPLY: We agree with the PPRP about the need of a full Tl Team participation. The Tl Lead will take responsibility to ensure that all members of the Tl Team participate fully and, if necessary, actively asking each Tl Team member to make comments or ask questions during the Workshops. 2. Selection criteria and decision date for GMPEs. Some of the ground motion prediction equations (GMPEs) presented and discussed at the workshop appeared to the PPRP to be at a less mature stage of development than the others. For example, one has not yet been fully described and documented in a formal publication. We recommend that the Tl team formulate and document, as soon as possible, clear criteria to be employed to determine which GMPEs will be used in hazard model development, and that documentation of the acceptance criteria Reply to PPRP Commentary Letter on SWUS Workshop #2 -Jan. 6th 2014 Page 1 include a justification, and that it specify a firm cutoff date for achievement of the criteria, based on a realistic assessment of schedule requirements. The selection criteria should be applied on a consistent basis to all candidate GMPEs. REPLY: Agree. We are currently planning on accepting GMPEs finalized (stable) and adequately documented by the end of 2013. GMPEs selection criteria will be clearly documented in the final project report, together with evaluation on applicability of the models for the project. 3. Completeness of proponent-model analysis in Workshop #2. The project team made a thorough effort to identify, select, and invite proponents of alternative interpretations. Not all invited proponents were able to attend the workshop. In the absence of a proponent to support the GMPE and magnitude-scaling recommendations of Dr. Zhao and his colleagues, their viewpoints on magnitude scaling of ground motion were solicited and presented by the Tl Team; therefore an opportunity existed at the workshop to discuss and challenge them. This approach was fully consistent with guidance in the NRC SSHAC guidance document (NUREG-2117) ( p. 70), which states, for example: "Because not all proponents of alternative viewpoints may be able to attend the workshop, interpretations made by individuals who may not be present should be identified and discussed." On the other hand, Dr. Idriss (author of the Idriss NGA-West2 GMPE} and Drs. Atkinson and Assatourians (developers of the finite-fault stochastic simulation method, EXSIM) also were absent, yet no representatives were designated to represent their models. As a result, discussion and debate of the merits of these two models were largely incomplete. The PPRP recommends that the Tl team make an additional effort to complete the evaluation of these two proponent models at a level equal to that of the other models being evaluated. It should take place before the development of preliminary hazard models, and in a setting consistent with NUREG 2117, which stipulates (p. 39} that in a Level 3 study, the interactions with proponent experts should be "conducted openly in the presence of observers including the PPRP." REPLY: Agree. We plan on evaluating the two aforementioned proponent models during a special working meeting (January 28 and 29, 2014) in the presence of PPRP, while also inviting relevant Proponent Experts and Resource Experts who attended the Workshop #2. Back up plans have also been discussed to make sure the Tl Team has a chance to discuss the proponent model with the experts if the authors cannot attend the meeting. These discussions will be summarized at the special working meeting. 4. Completion of Workshop #2 objectives. The PPRP noted that there were many ongoing tasks that could not be evaluated in Workshop #2 because they were either incomplete or had just begun. The Tl lead pointed out during the workshop that these tasks will need to be fully discussed and evaluated in order for the Tl team to obtain feedback from the resource and proponent experts to factor into their evaluation. The PPRP agrees that there is the need for an additional meeting with resource and proponent experts, including the PPRP as observers, to cover these ongoing and incomplete tasks. The PPRP emphasizes, moreover, that sufficient time should be allowed between such a meeting and Workshop #3 to enable the Tl Team to fully evaluate and discuss the feedback from the meeting and incorporate that feedback into the preliminary ground motion logic tree and the related sensitivity studies that will be presented and discussed in Workshop #3. This concept is embodied in the NRC SSHAC guidance document (NUREG-2117) that states (p. 67) "Any new data collection activities should be identified early in the project, evaluated for their potential impact on the hazard results and associated Reply to PPRP Commentary Letter on SWUS Workshop #2 -Jan. 6th 2014 Page2 uncertainties, and completed in a timely manner for use in the technical evaluations. Typically, this would mean that the activities should be completed prior to Workshop #3 on Feedback and certainly no later than the time that the models are finalized; (p. 68) Each workshop has a specific focus and goal, and each requires that particular work activities have been conducted prior to its occurrence and certain work activities will occur following;" and (p. 73) "Following Workshop #2 and prior to Workshop #3 Feedback, multiple working meetings will be necessary to develop a preliminary model that can be used for purposes of sensitivity analyses to provide the necessary feedback to the Tl Team." Tl Team should consider scheduling this additional meeting such that there is sufficient time between it and Workshop #3 to prepare and revise the preliminary ground motion logic tree and to perform related sensitivity studies. REPLY: Agree. The special working meeting planned at the end of January 2014. This provides adequate time for the Tl Team to incorporate the information from the working meeting into the initial GM model to e presented at Workshop #3 5. Schedule and prioritization. Over the course of the workshop, numerous technical issues that are currently under investigation were identified as requiring substantial further work before certain modeling procedures can be included in a hazard model. The PPRP is very pleased that the project has initiated important investigations that are likely to have a big impact over the longer term, and the fact that some will not reach full practical implementation during this project is understandable and inevitable in an effort such as this one. As the Tl lead noted, in the short term, incomplete resolution of these technical issues can be accommodated in the hazard model through appropriate expansion of epistemic uncertainty estimates. The PPRP urges, however. that the Tl team reach a prompt decision on which efforts to prioritize for inclusion in the hazard model. That decision should consider hazard sensitivities, and should be made early enough to realistically account for project schedule requirements. For example, by Workshop #3, which is scheduled for March 2014, a preliminary hazard model should have sufficient maturity that the PPRP and others can meaningfully probe its technical basis and understand the manner in which it incorporates the views of the larger technical community. We also note that a preliminary report is due for PPRP review within just a couple of months following Workshop #3. REPLY: Agree. We are using hazard sensitivity to identify the critical technical issues. Sincerely, Carola Di Alessandro, SWUS GMC Project Manager CC: PPRP Panel, Tl Team, PTls Norman A. Abrahamson, SWUS GMC Tl Team Lead Reply to PPRP Commentary Letter on SWUS Workshop #2 -Jan. 6th 2014 Page 3 May 23, 2014 Steven M. Day Chair, Participatory Peer Review Panel Department of Geological Sciences San Diego State University 5500 Campanile Drive San Diego, California 92182

Dear Prof. Day:

The Tl Team and PM appreciate the valuable comments and suggestions received from the Participatory Peer Review Panel (PPRP), both during the Workshop No. 3 execution and in their formal letter commentary dated April 21, 2014. The present document serves to provide written responses to specific comments, suggestions, or recommendations that the PPRP identified (by underlining). 1. Documentation. As noted in the summary comments, the ground motion model contains a number of advanced elements aimed at providing improved confidence that the CBR of the TOI is being captured. The scientific development and validation of these advanced elements has been driven in large part by this project. The technical bases for these elements appear to be sound, and they represent significant advances in hazard assessment. However, because they are technically advanced and relatively complex, they will have to be carefully and fully documented in the project report. Careful and clear documentation of complex procedures and concepts (for example, the construction of a multidimensional GMPE space, its visualization via Sammon mapping, and its final characterization from representative points on that map, in light of disparate data sets and simulation results) may be critical to project success. The PPRP recommends that Tl team members pay close attention to the documentation of these advanced model elements to ensure that the final report is not only complete and scientifically sound. but also as transparent and persuasive as possible to the PPRP and a broader technical audience. ?EP:Y: We agree Lhe 81 ::.he nat*;, 1". ciraft j:::ur:-1al paper*,.,, .. be :::::::T1p.eted r*:-.e ,.:;-u*y Griefing 2. Site effects interface issue. During the workshop, it became clear that the project had not yet produced a comprehensive reference document describing the adjustments and procedures to be used to modify the reference ground motions for use at each site (i.e., at PVNGS and DCPP). The PPRP previously recommended that such a document be developed in a letter to the Project Manager dated April 21. 2013 (Recommendation #6) following Workshop #1. and this recommendation is repeated here. As noted previously, any lack of clarity and precision in the communication between the Tl team and a site response analysis team may make both vulnerable to misunderstandings and claims of inconsistency or double counting of effects. A comprehensive 1 written document would serve to guide discussions, prevent misunderstandings, and ensure that no relevant data or models are neglected due to confusion about which project is responsible for which elements of the ground motion model. ?RP:.Y: We agree. A will be co:rpleted si:-e respcnse *,rnrY.: it; !>ti\r:-.ed. 3. SSC interface issue. The workshop revealed some apparent gaps in coordination between the Tl team and the respective SSC Tl teams for the DCPP and PVNGS SSHAC Level 3 projects. For example, the Tl team appeared to be unaware of the inclusion of strike-slip sources in the source component of the SSC model for PVNGS, and only presented GMC models relevant to normal faulting. As a second example, the Tl team discussed the PVNGS local-source component in terms of random fault orientations, whereas the PVNGS SSC Tl team will provide preferred orientations in the final SSC model. A further concern is that the DCPP SSC model might include a large range of rakes on dipping faults, and some coordination between that project and the GMC project may be required to ensure that those sources are appropriately categorized for use in the GMC model (e.g., the treatment of oblique slip sources was not discussed by the Tl team). The PPRP recommends that the Tl team improve coordination with the Tl teams of each of the SSC projects to ensure that the GMC approach is fully compatible with the respective SSC approaches, so that last-minute issues will not arise that could delay project completion. ?fo.P: Y: ;.".ie a.qree. ': .. !e :-::.-.ve a -:-e:.:i::Jv i :rp:-cveci :-.'.-:e : :r:e:-:.ict o:-: with :-.:-:e for :i::d PVt\C:-;. 'i*!e :;ee ilr:y tiona.:_ al Lhls L.:_nc. 4. Feedback on a complete preliminary model. The workshop provided a very good exposition of the conceptual framework of the ground motion logic trees to be employed, as well as their technical bases. In most cases, the specific branches were identified, and there was extensive technical questioning and discussion from the PPRP and other experts, meeting most of the workshop objectives. Nonetheless, the model feedback process was not quite completed at Workshop #3, because a complete preliminary model populated with weights was not available to be interrogated by the PPRP at that time. As noted in NUREG 2117 (p. 71), "In the discussions of the preliminary models, the technical bases for the assessments and weights should be described to allow for a discussion of the implications and constraints provided by the available data." The PPRP supports the Tl team's preliminary decision to hold one or more briefing meetings to present a full preliminary model to the PPRP for feedback when it becomes available, in advance of their development of the final model. 'f'!e *:_,,;: :1d:Lt.io:::1.:_ ::i\Ve beer: *,::_th the :::*PRF: :..he ..'..l.:-sl 0:1c on Eay -_t;, l_hc scco:1c:. cr:c Ju-_y 17--_8, 5. Geologic consistency of models for ground motion simulation. The numerical simulation of specific sources at DCPP employed fault geometrical parameters (in particular, down-dip fault widths) that are not consistent with the SSC model. The PPRP recognizes that this may be largely an artifact of the way the numerical models are parameterized, together with the understandable project requirement to hold that parameterization fixed in the form it had when the numerical models were calibrated and validated. The PPRP also recognizes that the principal application of the simulations to date has been to test methods for combining empirical relationships so as to approximate special conditions not represented well in the database, such 2 as the simultaneous rupture on a main fault and a secondary splay. In that type of application, the PPRP agrees that the results may be insensitive to the precise simulation geometry relative to the SSC model. However, the appearance of discordance between the simulation parameters and actual fault parameters developed by the DCPP SSC is a potential source of confusion. The PPRP recommends that project documentation give careful attention to any apparent inconsistency between the ground motion simulation parameters and the actual fault parameters developed by the DCPP SSC team. Where simulations are used only to test methods for applying empirical methods to special situations, the Tl team might evaluate whether to simply treat the simulated faults as representatives of generic fault types, rather than associating them with specific faults from the SSC model. On the other hand, if simulated ground motions are employed more directly, it will be necessary to document with care their actual relationship to the SSC model. 'i*!e :...he Broad 3an..:;. L .. a:...lo.rr.1 exn the : 'n'::a::icn t::P. lin:_ :-.a::i :r:!> ::::P. c<.,p:ibil:_ tie<; o.: (B::H'J .i.n Lcrr.1::; ol .s::;urcc c:ha.:-ac1 .. cr.i..sL.i.c::;, a:1c:. cf the ::a the SSC 6. Representation of CBR of hypocenter locations. In the development of the model of additional standard deviation to account for rupture directivity, the Tl team assumed a model of hypocenter locations in which strike-slip earthquake epicenters had a tendency to concentrate near the center of the rupture trace. The team cited empirical results of Mai and others in support of this assumption. However, other relevant data are available (e.g., global compilations such as that of McGuire et al. in BSSA, 2002, as well as data from detailed studies of individual earthquakes in California and elsewhere). If the form of the hypocenter distribution is significant to the conclusions of the directivity study, the PPRP recommends that the Tl team further evaluate the hypocenter distribution model to ensure adoption of a final version that adequately captures the CBR of the TOI. ?Rr-v: agree. for ::he eva. * .. w:-.ed. 7. Frequency shift of between-event standard deviation. The Tl team showed at the workshop that, if not removed by smoothing (as was done by some NGA-West2 developers), the event standard deviation tau has a so-called "bump" at short periods that is not as visible in the within-earthquake standard deviation phi. The Tl team showed evidence from a simple stochastic analysis that this bump is likely due to systematic variability in site effects, presumably due to variability in kappa, that is being transferred to tau and should, therefore, be included as part of the within-earthquake variability. Based on this conclusion, the Tl team has adopted as part of their logic tree a smoothed short-period tau model with no bump and instead is transferring this aleatory variability to the site-response model. One of the interesting features of the bump in tau, which is often described as being at 0.1 sec (10 Hz), is that it occurs at a shorter period for small earthquakes than for large earthquakes and has a pronounced dip near 0.3-0.5 sec, which also changes with magnitude. The PPRP recommends that the Tl team seek an explanation of the apparent frequency shift of the bump and dip in tau with magnitude and assess whether it is consistent with the proposed hypothesis that these effects represent variability in site effects rather than source effects. p::-,:-,r.v: The apparent o-:' the t* .. ::r::-; anci ciip ::.at: "':'::h is a. 2f the of :egio:-:s for :i::d L1 rqe 1:1<H.:pi 'i*!e * .. ev:1l 1:iltP. th:_;; :_;;;;-.:e by :_nq the 3 ta*_: f:::r sr1a--larqe f:--:::T1 a :--eg'o:-1 as see if the is no cbserved as 8. Epistemic uncertainty in median prediction. The epistemic uncertainty in predicted median ground motion includes two components -the within-GMPE uncertainty of estimated GMPE coefficients and the between-GMPE variability. At the workshop, the Tl team's proposed approach for evaluating the latter component of uncertainty (via the construction of GMPE space) received substantial discussion and helpful feedback. There was, however, not as much discussion of the within-GMPE uncertainty. Since uncertainty in median motion is an important contributor to the uncertainty in calculated hazard, the PPRP recommends that both GMPE and within-GMPE components of epistemic uncertainty be evaluated with comparable rigor and that each be represented in the logic tree with an appropriate level of detail. K: .. :::' L:: A!> !> ho,:;:1 i:1 :-.::e .J <HF Ji.\ r*; 2 Cl 11 Y.: :.-:1q i nq by X . ::.:*.1e:: r:, the *,.;i *; 'l!> by A.:_ -.r-.:::.-Y.: a:1d :ou:1q<; pc.;::..c<, n.:;r)or:-. 0:1 cp.i.s:..cn.:_c: u:1c:e::::La.:_n:_y .i::; 1r....;ch :::;ria.:_.:_c::: L:*:c :oc:..*:.:e:e:r:-r.1oc:.c.:_ epi.ster1'::: ar:::I is bei:-1g ::::aptureci *:::y :::vera--rar:.:;*e 'n the node:s develcced. We we be able to thi<; to be ::::2 c<Lie :-.he fine.\.:_ :r.:::d2.:_ a:1d, thP.ref:::::::2, 0:1 :::* .. ::::: o.:_ unccr:..a.ir:Ly :..8 dcvc.:_8p Lhc o.:_ X8dc:s. We hope this letter clarifies the questions and comments stated in the April 21, 2014 PPRP Commentary Letter. We wish to express our gratitude to the PPRP again for their insightful questions, and for their continuous review of this project. Sincerely, / -.. Norman A. Abrahamson, Carola Di Alessandro, SWUS GMC Tl Team Lead SWUS GMC Project Manager CC: PPRP Panel, Tl Team, PTls 4 The following documents may be grouped as follows: I. Source Characterization PPRP A) Completed PPRP Comment Response Log PPRP Comment-Response Log_Appendix C_2015_03_04.pdf "5-; PPRP Comment-Respome Log_Appendix 0_2015_02_27.pdf PPRP Comment-Response Log_Appendix E_2015_02_27.pdf PPRP Comment-Response Log_Appendix F _2015_02_27.pdf PPRP Comment-Re'.;ponse Log_Appe:nclix G_2015_03_05.pdf PPRP Comment-Response Log_Appendix H_2015_02_27.pdf "5-; PPRP Comment-Respome Log_Ch l-4_2015_02_14.pdf "5:: PPRP Comment-Response Log_Ch 5_2015_02_16.pdf PPRP Comment-Response Log_Ch6_2015_02_20.pdf PPRP Comment-Re!:ponse Log_Ch7_2015_02_23.pdf PPRP Comment-Response Log_Ch8_2015_02_27.pdf "5-; PPRP Comment-Respome Log_Ch9_2015_02_20.pdf PPRP Comment-Response Log_Ch10_2015_02_27.pdf PPRP Comment-Response Log_Chlla_2015_02_23.pdf '5-:: PPRP Comment-Re!:ponse Log_Chllb_2015_02_23.pdf PPRP Comment-Response Log_Ch12_2015_02_18.pdf PPRP Comment-Response Log_Chl3_2015_03_04.pdf "5-; PPRP Comment-Respome Log_Ch14_2015_03_03.pdf B) PPRP Draft Report Comments *'

• J I 0:: -,:_ PPRP Comments Installment 1_2014_12_14.pdf -,:_ PPRP Comments Installment 2_2015_01_10.pdf PPRP Comments Installment .3_2015_01_21.pdf PPRP Comments Installment 4_2015_02_12.pdf PPRP Comments Installment 5_2015_02_20.pdf ,_Trans Ltr PPRP Installment 2_2015_01_09.pdf Ltr PPRP Installment 3_2015_01_21.pdf "l:._ Tram Ltr PPRP Installment 4_2015_02_12.pdf Ltr PPRP Comments Installment 5_2015_02_20.pdf C) PPRP Non-Mandatory Comments Non-mandatCr)' Ccmmi:nts 1st Round Re'.-01.pdf PPRP Non-Mandatory Ccmmi:nts_2015_Q2_28.pdf PPRP Non-Mandatory Ccmmi:nts_2015_Q3_Q6.pdf D} PPRP Workshop Letters and Responses -,.__ PPRP _Letter_',*VSl.pdf PPRP _Letter_',*'/S2.pclf -,.:_ PPRP _Letter_'NS3.pclf -,.__ P.esponse_to_PPRP _WS2.pdf -,.:_ Response_to_PPRP _1NS3.pdf II GROUND MOTION CHARACTERIZATION -,..:.. Attachment_ Other-1.p df -,..:. Attachment_ Other-3 .p df Attachment_Other-4-A.pdf Attachment_Other-4-8.pdf Attachment_Other-4-C.pdf Attachment_Other-4-D.pdf Attachment_PPRP-5b-A.pdf Attachment_PPRP-5b-B.pdf .,.., Attachment_PPRP-5b-C.pdf .,.., Attachment_PPRP-7.pdf .,.., Attachment_ ll_ T eam_PM-1.pdf II GROUND MOTION CHARACTERIZATION -,...:: Othe:r-1.pdf -,...:: Othe:r-2.pdf -,...:: Othe:r-3.pdf -,...:: PPRP-la.pdf -,...:: PPP,P-lb.pdf -,...:: PPRP-lc.pdf -,...:: PPRP-2.pdf -,...:: PPP.P-3.pdf -,...:: PP RP-4. p df -,...:: PPRP-5a.pdf -,...:: PPRP-5b.pdf -,...:: PPRP-5c.pdf -,...:: PPP,P-5d.pdf -,...:: PPP.P-6.pdf -,...:: PPRP-7.pdf -,...:: PPP,P-8.pdf PPRP-INTEP...A.CTION_S.\o'iUS._9Apr2015.docx -,...:: PP RP-INT E P...A.CTIO N_SViU 5_9Ap r2015. p df -,...:: TI_Te:am_PM-1.pdf -,...:: TI_Te:am_PM-2.pdf -,...:: TI_Team_PM-3.pdf -,...:: TI_Team_PM-4.pdf Comment Location in Text Number Line 152 Line 154 Line 235 Line 273 Line 307 Line 455 Line 207 Line 224 Line 292 Line 300,301 Line 315 Line 322 Line 545 Line 821 Line 948 Line 44 PPRP Comment Response Table Final Review PPRP Comment CHAPTER4 "This database has been supplemented" -"been" Describe should be past tense Add a comma after "study area", and another after "data set" Add a space between Central and California Add two commas -" ... sand spit and, based on detailed analysis of the relict shoreface, estimate ... ,, Delete *'for the" after **rates" CHAPTERS " ... stepping of the proto-transform fault 5 Ma to the ... " Is there a missing word here? "at 5 Ma"? Insert "at" between beginning and approximately(?) Insert "At" before approximately -"At approximately 12-10 Ma," ** . current location at the San Andreas fault between approximately 5 Ma. Between 5 Ma and when? Or, at approximately 5 Ma? Move the comma to outside of the quotation mark around "benched" This would read more clearly as "Dextral rates of slip ... " "include" should be singular This would read more clearly as The Lompoc earthquake of 1927, estimated at M7, is the largest event recorded ..... "sympathetic" or antithetic?? CHAPTER6 Typo in **seismogenic". Summary of Revisions to Report Table 6-1 In Table 6-1, 199 Hector Mine Earthquake: "The complex northward rupture initiated on an unknown north-trending structure (a splay to a previously mapped but unnamed fault, which is now referred to as the Lavic Lake fault) and propagated north on both branches of the Lavic Lake fault and propagated southward onto the Buillion fault (rupturing both the East and West strands of the Buillion fault." Details of this statement are incorrect. Actually, based on mapping of the surface rupture (Treiman et al., 2002), the rupture propagated bilaterally on the Lavic Lake fault (as the earthquake nucleated in the middle of that fault) and then southwestward onto the Bullion fault. Also, there is only one branch of the Lavic Lake fault north of the epicenter, unless you consider the splay fault a branch. Note the rupture is correctly described in ch 9 (lines 455-460}. CHAPTER7 Line 463 Need a space between " ... (Figure 7-Sb)." and "The alternative ... " Figure 7-18a The caption still has the apparent inconsistency pointed out in Comment 385 (the Response Log says it was "revised as suggested," but that does not appear to be the case). That is, shouldn't the reference to "sinistral ranspression" on the third line actually be "sinistral transtension .. ? There is no phase of **sinistral transpression" represented in the figure, so certainlv somethina is inconsistent. CHAPTERS Line 123 Need a space between ", .. therefore," and "the probability weights ... " Lines 339 & 340 Eolian is spelled 2 different ways -be consistent. Line 385 Delete space before period at end of sentence. CHAPTER9 Comment 551, This discussion is a good step forward, but it is not as explicit as it could as addressed be about how aleatory variability and epistemic uncertainty are in Chapter 9, accommodated, and distinguished, in the rupture-source framework. A Section 9.1. full reading of the report seems to indicate, roughly, that (1) the OV, SW and NE Rupture Models represent different logic-tree branches that (together with branches for the various magnitude pdf models and rupture-source slip rates) collectively sample and represent the range of epistemic uncertainty in the slip budget and the way that slip budget is distributed spatially and with respect to magnitude and style of faulting: and (2) the collection of rupture sources (and their respective magnitude pdfs) within each Rupture Model is designed to capture the corresponding aleatory variability in magnitude (and rupture dimensions). This is probably not quite the right formulation, but certainly some precise statement of this sort that is similarly compact and explicit would be valuable introduction to ouide the reader forward. Comment 566 Comment 566, Chapter 9, noted that the Los Osos-San Luis Bay splay occurs at an acute-angle fault intersection, and is therefore an exception to the stated rule that faults "that intersect at acute angles are not part of the same rupture source." The Tl Team response is that this exception doesn't need to be noted because the intersection is at depth, not at the surface. This is a non-sequitur the stated rule has no stipulation as to whether the acute intersection is in the surface trace or fault plane in general. This is a minor point to be sure, but it remains an inconsistency that leaves the careful reader confused and affects readability, and seems trivial to clear up. 641 The response given by the Tl Team appears to be a paragraph that is intended to be included in the text. Is this the case? Line 428 Correct spelling of Kickapoo CHAPTER11 543-546 Figures 11-11 through 11-15 are not included in the figures provided and the comments made by the Tl Team are unclear with respect to exactly what actions were taken to address the PPRP comments.

COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT PPRP COMMENTS AND Tl TEAM RESPONSES, APPENDIX C (HAZARD INPUT DOCUMENT) Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision APPENDIX C -Final SSC Model Hazard Input Document 869 Line 10 Model-building is restricted to the Tl Team. Suggest changing to "to Line 10 Text revised as suggested. implement" the SSC model. 870 Line 25 Are areal sources and areal source zones the same thing? Suggest Line 26 Text revised to list three areal source zones in the consistent use. model. 871 Line 30 Source-site? Source to site would be clearer. Line 30 Text revised as suggested. 872 Line Rupture sources for Hosgri Table H.2-4 lists 7 sources (all three FGMs): Table C.2-4 Table corrected to show 8 rupture sources. Rupture H-104 however. in Table H.2-6 there are 8 rupture sources for the Hosgri 08 is not on the Hosgri fault zone, but is grouped with Table the Hosgri ruptures to provide an alternative rupture H.2-4 7 source involvina the PB. 873 Line Should 7 ruptures be 8 ruptures? Line 131 Text revised to show 8 rupture sources 130 874 Line Please add the missing parenthesis at the end of the sentence. Line 185 Text revised as suggested. 184 875 Line Why are some "sub" rupture in italics? Line 190 Text revised to eliminate the italicized 'sub' 189 876 Table Standard deviation is zero?? Please clarify (e.g .. would it be more Table C.2-15 Text revised as suggested to use NIA. H.2-15 appropriate to say "n/a", as is done for truncation factor on the next line). Line 244 877 Line Might consider changing figure so it parallels text (a) maximum magnitude Figure C-7 and Figure C-7 and Text in Section C.2.5 reordered for 246 (b) Y-C characteristic (c) exponential (d) WAACY text consistency with Chapter 10 and between figure and Figure text, as suggested. H-7. 878 Line Delete "is" between "term" and "in" for clarity. Line 290 Text revised as suggested. 288 879 Line Why is OV-09 linked and Characteristic -why is it not Category B? Line 304 It is a linked rupture source because its longest length is 299 (LP+FS+FN+ON+OF) not capable of hosting an Mmax that differs meaningfully Table from an alternative Mchar. H.2-22. Please check other tables with linked faults H.2-24, H.2-26 880 Line Table H.6-1 has NE and SW dipping reverse faults; logic tree Figure H-13 FigureC-13 Figure edited to be consistent. Only NE and SW shown. 399 has N or NE and S and SW for the reverse faults -please make consistent. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT PPRP COMMENTS AND Tl TEAM RESPONSES, APPENDIX D Location in Comment Location in Text PPRP Comment Text for Summary of Revisions to Report Number Comment Revision APPENDIX D -Workshop Summaries 881 Line 21 "A GMC model -"A should be lower case Line 21 Text revised as suggested. 882 Line 24 Change are" to '"is" as the verb refers to Each workshop presentation" Line 24 Text revised as suggested. 883 Line 34 Consider spelling out RE at first usage in the appendix. Line 36 Text revised as suggested. 884 Line 53 You should not leave the reader with the impression that the master list Line 55 Text revised as suggested of data collection activities coming from the workshop was. in fact, funded. 885 Line 56 Delete "but." Line 57 Sentence revised for clarity. Conjunction needed for accuracy. 886 Line 56 Insert '"are" after "presentations" for clarity Line 55 Text revised as suggested. 887 Line 101 Typically, the term "hazard" is used to specify the annual frequency of Line 102 Added text after the word '"hazard" to clarify that exceedance (y-axis of the hazard curve). rather than the ground motion hazard is being used here as AFE (x-axis of the hazard curve) for a given AFE. Please clarify if this is the way that '"hazard" is used here and subsequently when talking about percent contribution to the hazard (i.e., is it the AFE or the ground motion at a aiven AFE?) 888 Lines 107 -108 '"none of the more distant faults contributes> 1 % to hazard ... " Is this per Lines 107-112 Text added to clarify that none of the distant fault fault? In which case, because there are a lot of faults, could sum to sources (with the exception of the SAF) significant hazard, or does this mean that these distant faults individually contributed> 1% to total hazard, cumulatively amount to < 1 % of total hazard? Please clarify. though cumulatively (with the SAF), they contributed -5%. In considering fault sources individually, the Hosgri. Los Osos, SLB. and Shoreline are still the most important for hazard. 889 Line 113 Delete 2nd '"that." Line 117 Text revised as suggested. 890 Line 113 The tornado diagrams actually show the sensitivity to hazard uncertainty, Lines 116-122 Text revised to describe tornado diagrams as rather than to hazard itself. Suggest stating that they show the range in depicting sensitivity to hazard uncertainty: "In hazard results for the range in values of an input parameter in the logic addition, Ms. Wooddell examined the ranges in tree. Thus, they show how much uncertainty in a parameter leads to hazard results for the range in values of various uncertainty in the hazard result. If no uncertainty is included for a given input source parameters associated with the four parameter. it shows no contribution to hazard uncertainty. nearby faults, including slip rate. fault dip/geometry, crustal thickness, and fault length (including joint ruptures). The resulting ranges in hazard results, or sensitivity to hazard uncertainty, are presented in "tornado" diagrams that rank the source parameters in order of "most significant" to '"least significant" to hazard uncertaintv at Diablo Canvon. As shown on COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT the tornado diagrams (for PGA. T=0.2 sec. and T=2.0 sec) provided by Ms. Wooddell. the source parameters that are most significant to hazard uncertainty at Diablo Canyon are, in order of significance ... ** 891 Line 114 Delete the extra "that" Line 117 Text revised as suggested. 892 Line 186 Insert "USGS" in front of ".CRADA Line 190 Text revised as suggested. 893 Lines 261-271 Change all "Mr. Thatcher citations to "Dr. Thatcher" -use is inconsistent Line 271, 274 Text revised as suggested. here. 894 Line 283 Insert "for" art er "rotation" for clarity Line 287 Text revised as suggested. 895 Line 329 "Rate" should be singular(?) Line 334 Text revised as suggested. 896 Lines 330-333 Is the maximum unaccounted for plate motion parallel or normal to the Lines 338-348 Text added to clarify that the trend of the SAF? Please clarify. unaccounted plate motion is a function of the assumed SAF slip rate. where an assumed SAF slip rate of 28 mmlyr results in -6.5 mmlyr of unaccounted plate motion distributed with a trend of N27°W and an assumed SAF slip rate of 32 mm/yr results in -3.5 mm/yr of unaccounted plate motion distributed with a trend of N12*w 897 Line 442 Check spelling of "Mohorovic." Line 453 Text revised as suggested. 898 Line 469 Please change "daps" to "gaps." Line 480 Text revised as suggested. 899 Line 500 Heave is not associated with the presence of a shallow/hard bottom -Line 513 Text revised to state that "seafloor reverberation rather it is related to sea state that may result from the presence of a shallow/hard bottom and heave (vertical motion) of data acauisition vessel" 900 Line 523 Insert "depth" -so ii reads "10 to 15 km depth." Line 537 Text revised as suggested. 901 Line 567 "Investigations" is lower case Line 579 Text revised as suggested. 902 Line 637 Should PPRP comments and Tl team responses be inserted here for Lines 31-32 Statement added to the end of the introduction that Workshop #1 and likewise for WS#2 and WS#3? If not, then please point the PPRP comments and Tl Team responses are the reader to where thev can be found. included in the oroiect files. 903 Line 672 Consider deleting first "sensitivity." Line 655 First "sensitivity" in sentence was replaced with "SSC framework" 904 Lines 822-824 Did Hamilton conclude or present this or is this inferred by the Lines 836-839 Tl Team inference of his model removed from the relationships he reported -if the latter might want to consider deleting. discussion. 905 Line 889 Clark reference? Line 902 Text revised to state "Clark et al.. 1984" instead of "e.g., J. Clark"; reference added to reference list 906 Line 981 Replace "or" with "to" Line 994 Text revised as suggested. 907 Line 988 In the near "shore," i.e .. add "shore" Line t001 Text revised as suggested. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT 908 Lines 1077-1078 This might be stated more accurately as incorporating the additional Lines 1089-Text added to clarify this statement: ... beyond the uncertainty that would result from considering non-Poissonian temporal 1092 traditional Poisson recurrence distribution by models, such as a renewal model. considering non-Poissonian recurrence models (e.g., Brownian Passage Time or other renewal models). 909 Line 1116 Replace "N." with "Dr." Line 1130 Text revised as suggested. 910 Line 1131 Should PPRP comments and Tl Team responses for WS#2 go here? Lines 31-32 Statement added the the indroduction section. 911 Line 1225 Insert "then" -so it reads "then replaced." Line 1239 Text revised as suggested. 912 Lines 1259, 1262, "Mr. Abrahamson" should probably be replaced by "Mr. AbramsonWard". Line 1273, Text revised as suggested. 1277 Please check and correct if necessary. 1276, 1291 913 Line 1289 Spell out "HIV" ("horizontal to vertical") for clarity Line 1284, Text revised as suggested. Line 1295 914 Line 1290, 1291 Replace "Mr." with "Dr." Line 1305, Text revised as suggested. 1307 915 Line 1291 'These data yield". Actually, these are not data, but rather. Line 1297, Text revised as suggested. interpretations. 1314, 1471, 1476 916 Line 1312 Please replace "frequency" with function" to reflect the correct Line 1327 Text revised as suggested. interpretation of "CDF." 917 Line 1385 "and is it ready ... " would read more clearly if written "and questions Lines 1391-Text revised as suggested. whether it is ready ... " 1392 918 Line 1393 Replace "The" with the" Line 1408 Text revised as suggested. Also add period at end of sentence. Check the other PPRP sentences like this one as thev also are missino periods at the end of the sentence. 919 Line 1400 Replace *'generals with **general." Line 1415 Text revised as suggested. 920 Line 1608 Replace period with a question mark. Line 1623 Text revised as suggested. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT PPRP COMMENTS AND Tl TEAM RESPONSES, APPENDIX E Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision APPENDIX E -Data Summary and Geospatial Databases 921 Line 3 Data is plural, so change "was" to "were" Line 3 Text revised as suggested. 922 Line 40 Insert "the" between "as .. and "Shoreline" Line 47 Text revised as suggested. 923 Page Y-Replace "maps .. with map Page E-2-3 of Text revised as suggested. 8 Attachment E-2, Folder Folder name name .. \Geographic_fe .. \Geogr atures aphic_f eatures 924 Page Y-(198") year? Page E-2-15 of ..... had been listed because the exact date was 20 Attachment E-2, unknown. Text revised to state that the date is unknown. Folder Folder name .. \ name Other_ data\Core .. \other_ hole _locations data\Div er_geol ogy COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT PPRP COMMENTS AND Tl TEAM RESPONSES, APPENDIX F Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision APPENDIX F -Earthquake Catalogs 863 Line 28-Please consider whether there is actual support for the claim of "better -Lines 32-35 Comparative statement deleted as suggested. Text 29 quality relocations than other available methods." Inserting this claim does describing the important tomoDD attributes (improved not appear to add any useful information, and an option would be to absolute and relative earthquake locations by delete the comparative statement and instead to state what specific incorporating ray tracing in a 30 velocity model and attributes tomoDD provides that proved important to the outcome. differential travel-time data, respectively) was added. 864 Lines States that focal mechanisms were assigned a quality rating of A through Lines 117-125 Text revised as suggested. Quality criteria of Hardebeck 104-108 C, but the lower-quality D rating was introduced. It would be clearer to and Shearer (2002: quality of A -C) are defined, as well state that they were assigned a quality rating of A through D, and then as well as quality D (Hardebeck's examination of polarity qualify the various ratings. data and visual inspection of solutions that did not meet at least one of the Hardebeck and Shearer (2002) criteria). 865 Lines These two sentences sound contradictory, ie., there is "no material Lines 178-182 Text revised to state that there are few differences 143-147 difference," yet there is a "difference of note." Please reword to avoid the between the datasets. Reference to Chapter 12 of the appearance of inconsistency. report is made for discussion of the location of the Given the differences in locations, what was done? Either state the Lompoc earthquake. decision here or point to where it is discussed in the report. 866 Line Refers to attachment X-3, but this was not provided. Same with Lines 145, These are provided as separate text documents. 161 attachment X-4 on line 173. 146, 149, 166, and 197 867 Citation These are electronic files provided to S. Thompson, but where are they Attachment F-Included as Attachments F-3 and F-4 to this appendix. sPG&E now? If someone wants to look at these files, how would they acquire 3 and 2014a them? Is there a URL that can be referenced? Attachment F-and 4 2014b 868 Figs. X-The explanations of these figures have the same spelling errors noted in Figs. F-1, F-3, Figures revised as suggested. 1, X-3, figs. 13.3. 13.4 and 13.5. and F-4 and X-4 COMMENT-RESPONSE LOG DIABLO CANYON SSC STUDY DRAFT REPORT PPRP COMMENTS AND Tl TEAM RESPONSES, APPENDIX G (WAACY MAGNITUDE PDF) Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision APPENDIX G -WAACY Model 785 Line 27 Might want to use another word than characterize as ii might introduce Line 5 Text revised as recommended. "describe" chosen instead confusion with "characteristic model" 786 Line 34 Is this the motivation that the authors of the model had for developing Line 13 Text revised to past tense as recommended it in the first place? If so, this should be past tense. 787 Line 44 Any recurrence curve, by definition, permits a broad aleatory variability Line 25 Broad aleatory variability was not described as a constraint It in magnitude. Not clear that this is an actual constraint. Isn't the real was described as a need. The real constraints are exactly as constraint that large Mmax*s are allowed (more than the characteristic stated in this comment (large Mmax's and small CVs), and are earthquake model) and small CVs are met (unlike the exponential described in the previous sentences. model)? The text has been revised to emphasize that the need was for aleatory variability in magnitude above Mchar. 788 Line 47 Note the missing")". Line 34 The descriptor "hump" has been removed 789 Lines Please clarify what the distinction is between "fits a doubly-truncated Line 39 Text changed to read " ... is a doubly truncated ... " 52-53 exponential" and "is a doubly-truncated exponential". 790 Line 68 Mmin of 5 is used for hazard integration, but is not common practice Table G1 Table entry revised to clarify that Mmin of 5 is a standard of for purposes of earthquake recurrence, especially when fitting practice for PSHA recurrence curves to observed seismicitv. 791 Line 68 "Values larger than 3 yield results that are indistinguishable from 3 for Table G1 Text revised as recommended Table the DCPP." This is a bit confusing. Why not state that "values of 3 and W-1, larger yield results that are indistinguishable at DCPP" bh;gh box 792 Lines What units are used in Dave? Centimeters? Meters? Lines 70-72 Not critical to the appendix. The equations have been removed 78-79 from the body of Appendix G, and are included instead in Attachment G1. 793 Line 92 Replace S08, 13 with S09, 13 Line 81 Text revised as recommended. 794 Line Please check whether this is the first reference in the text (apart from Line 84 Text revised as recommended 104 Table W-1) to the 0.55 value of the displacement CV threshold. If so, please indicate here that you refer to the 0.55 threshold estimated by Hecker et al. (2013). 795 Line Suggested should maybe be "suggest". as it still applies. If accepted, Line 88 Text revised to present tense. Suggests is used to agree with 139 change "included" in line 140 to "include" inspection. Include is used to agree with parameters. COMMENT-RESPONSE LOG DIABLO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 796 Line II appears that instead of "values and weights of the fixed parameters Lines 95-96 *weights" is deleted to clarify. 142 being shown in Table W-2, it is actually parameter name and fixed value. Please clarify. 797 Lines "We note that for Group B cases, the parameter combination of 12% Figure G-4 The logic is as follows. 209-moment and b,,,9,, = 1 exceeded the CV threshold value of 0.55 (Figure On figure G-4c, the three points above the CV threshold are all 211 W-5)." btail = 1. Since btail = 1 is given a weight of 0 for group C, all other values are under the CV threshold. For group B, which Please discuss weighting for Group B versus Group C for 12% has low weight on btail = 1, half of the group B points are moment in Figure W-7. Based on Figure W-6, It appears that Group C above the line. Thus, for non-zero weighted alternatives. group should have an equal or lower weight than Group B for the 12% B performs more poorly for F1 = 0.12 than group C. moment? We note that, since the revised parameters, the groupings have less distinction. The review comment is noted and the Tl Team judges that the difference in weights across the groups has negligible impact on hazard. especially given the sensitivities in Chapter 14. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT PPRP COMMENTS AND Tl TEAM RESPONSES, APPENDIX H Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision APPENDIX H-Method For Estimating Time Dependent Fault Hazard in the Absence of an Earthquake Recurrence Record 499 Line 45 "Poisson probability distribution of ground rupturing earthquakes is Distribution of what? And, in fact, the Poisson distribution itself (probability of exactly n occurrences in a given time interval. as a function n) is never used in the report. Please consider changing to a more Lines 47-48 precise statement (e.g., "the model of ground rupturing earthquakes as a reworded Poisson process assumes that events occur randomly in time"). 500 Line 47 rrhis would be clearer if "to occur" is inserted between "more likely" and 'when the energy Line 49 done 501 Lines 58-60 PSHA also initially did not consider the faults that gave rise to earthquakes; seismic sources were source zones, each of which likely included Rewritten to open the paragraph with this point. faults. The point should be made early in this section that the whole Lines 59-60 Historical reference for PSHA was distracting, and ime-dependent recurrence concept is for fault-specific recurrence removed. behavior. 502 Line 66 rrhe word "be" seems to be missing between cannot" and "rigorously". Line 65 Yes, fixed. 503 Lines 67-68 Consider indicating that an additional reason for the use of the Poisson model is that regulatory design criteria are expressed as target annual of exceedance (e.g., 10-4) without consideration of any time klependence. Lines 66-69 Good, added. 504 Lines 70-71 Bui. as you discuss below. the use of an equivalent Poisson rate does NOT require a change in the hazard code, just inclusion of the concept in the Lines 71-75 This section has been rewritten and hopefully clearer. SSC model. Please clarify. 505 Line 97 'Cumulative density function" is incorrect; please rewrite as cumulative klistribution function." Line 99 yes, changed. 506 Line 162 rrhe phrase "before reaching the long-term mean" could be misinterpreted o mean that the CP ratio is asymptotic to the long-term mean. which isn't Lines 148-150 Text has been reworded. The asymptotic value depends l)enerally the case. Please consider rephrasing to avoid ambiguity on this on the recurrence model width parameter. ooint. 507 Lines 166-Are you saying that we have absolutely no idea what the value of these 167 parameters might be? Or that we have no direct data upon which to base Lines 151-153 No, not the intent. Reworded. hem. but they can be estimated with considerable uncertainty? 508 Line 180 rrhe phrase "although it coincides numerically with the data estimate of the Reworded along the lines suggested in the comment. more familiar coefficient of variation" seems unnecessarily cryptic. Since. in Matthews et al. (2002) prefer the term aperiodicity as a its role as a parameter in a PDF (Eqn 10), alpha is equal numerically to the Lines 161-162 more general description, and their paper defines BPT in CV, please clarify why it cannot simply be said to be the CV. seismological use, so mention of aperiodicity is to respect their more mathematically informed preference. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 509 Lines 205-statement is not always true for faults having good paleoseismic data. The sentence starts "Individual values for Dare not 206 Please qualify that this information is assumed to not be known for the Line 185 normally known,", and explains what we do when Dis *aulls in this exercise. not known. 510 Line 210-211 'The distribution conveys a relative agnosticism among choices in lclisplacement per event (DPE) from 1.5 meter to 3.5 " Line 191 Fixed in text. Figure EPR-3 shows DPE from 1.5 -3. 511 Line 213 Up to 5.0 m in the text of the report (line 258, page 14 of chapter 11 ). Please check and rectify if different. Line 192 5.5 m was intended. 512 Lines 214-Please consider changing to the following (less fragmented) -216 In California. for example, the largest measured average slips per event on he San Andreas fault are 4.45 and 4.3 mlevent for the 1857 and 1906 earthquakes, respectively (Biasi et al., 2013). Lines 194-196 Changed as recommended. 513 Lines 218-22 reference to an upper bound of 5 mlevent in the text appears to conflict lwith values up to 5.5 mlevent given by the solid curve in Figure 3 (there is a Plots have been modified to end at ranges shown in the break in slope at 5.5 min the plot, indicating a non-zero probability point at text. The DPE is implemented as a list with non-zero hat value of sliplevent). Likewise, reference to an upper bound of 4 Figure H-3 entries for the Hosgri from 0.5 to 5.5 in 0.5 m mlevent in the text appears to conflict with values up to 4.5 mlevent for the increments, but the plot incorrectly implies weight above lclashed curve in the plot. Please check and make any changes required for 5.5 m. The same shape considerations affect plots of lconsistency. other OPE curves. 514 Line 227 If L TM is displacement per event divided by fault slip rate, then L TM must be an inverse rupture rate (or mean recurrence time), not a rupture rate as Line 206 LTM does have units of mean recurrence time. Text in stated. Please check the text for consistency and correct as necessary. the affected area has been modified accordingly. 515 Line 247 Please replace "to" with "do" Line 225 done 516 Line 265 If the reference to Philibosian et al. is the same article listed in the references section, then it should be cited as 2011 (rather than 2012). Line 243 Revised to 2011. Please check and make a correction if necessary. 517 Line 268 lsince the EPR is a dimensionless ratio, not a rate, it would be clearer and less subject to confusion to call it something else. Later the EPR is The EPR is a ratio, as noted by the reviewer. The text estimated from the distribution of "conditional probability ratio (CPR)", nla erminology that explicitly indicates the dimensionless character, so calling (and several figures) have been modified accordingly. EPR a rate and CPR a ratio is a source of confusion Please consider this point. 518 Line 275 Please replace "complimentary" with "complementary." Line 266 Yes, fixed. 519 Line 283 IA comma is needed after "renewal" to set off the first part of this sentence Line 275 Done 520 Line 284 tThe tl TM" appears to be a typo-please check whether this should be Line 276 Fixed as suggested, and the word "small" removed 'LTM". because it conflicted with the direction of the sentence. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 521 Line 286 It will cause confusion to say that the CPR is elevated relative to the Poisson rate, because the former is a dimensionless ratio and the later is Wording has been changed to distinguish between the l'ln absolute rate (events/unit time). Please rephrase this to be more Lines 278-279 ratio and the corresponding rate. precise. 522 Line 286 rrhe distinction between CPR and EPR is never stated explicitly, and this l'.;auses confusion later on. The eventual impression is that CPR is treated The first paragraph under "Estimating Equivalent 11s a random variable and EPR its estimated value: if so. please consider Lines 245-259 Poisson Ratios" is largely new and dedicated to clarifying making this explicit, and if not, please add text to clarify the the relationship between CPR and EPR. The second mathematical/conceptual distinction between them. paragraph covering Figure 5 has also been rewritten. 523 Line 288 rrhe phrase "declines to approach the Poisson rate at the upper probable range of tMRE" may be misleading. First of all, since EPR is a ratio, it approach unity if the CP approaches the Poisson probability? If This section has been reworded and the explanation please rephrase to make that clear. Secondly, the phrasing can be Lines 279-286 interpreted to imply that the approach to the Poisson rate is an asymptotic extended. behavior. As that is in general not the case, please rewrite to avoid that impression. 524 Line 297 rrhe peak appears to occur below the diagonal in Figure 6. not above the kliagonal as stated. Please add clarification or correct the statement or Lines 296-300 Rewritten. "igure as necessary. 525 Line 303 rrhe term "joint probability surface" appears to be used here to denote a 'oint probability density. However, this is not made explicit. and doubt is raised by Figure 7, in which it is obvious that the integral under the surface The explanation of the joint probability surface used for is much greater than 1. ruling out its interpretation as a joint PDF. Further Lines 301-311 weighting has been extended and clarified. The fact that arises from Equation 13, as discussed in a subsequent comment. Figure 7 was normalized by its maximum value has been Please be explicit and precise about what is meant by "joint probability stated in the text. 526 Line 303 rrhe joint probability appears to depend upon slip rate. If that is a correct interpretation, please indicate (in the text and caption) what slip rate was used to generate the probability function in Figure 7, and confirm that that Remarks on the relationship of slip rate to individual EPR rate plus the Hosgri OPE model of Figure 3 was the basis for the Lines 301-311 estimates were added in a new paragraph inserted to marginal distribution p(L TM) used to generate that figure (or if, that is introduce the "Estimating Equivalent Poisson Ratios" incorrect, give the correct explanation). If the joint probability does not section. k!epend upon slip rate, please improve the description to make clear why not. 527 Line 308 rrhe survivor function S(tMREIL TM) integrated over tMRE (for fixed L TM) is not generally unity. p(L TM), being a PDF, does integrate to unity. So W integrated over the tMRE,L TM plane is not generally unity. Therefore Wis not a joint probability density, yet the text gives the impression that it is The survivor function actually does have unit area, by intended to be just that (though that interpretation is also cast in doubt by construction. This was obliquely the point of the Figure 7. as noted in a previous comment} If W is something other than a Lines 313-320 sentence in former lines 313-315. The discussion of oint PDF. please explain clearly what it is. If W is a joint PDF. but the weighting, area of the S. and the mathematics have reasoning in this comment to the contrary is incorrect. please clarify in the been rewritten. ext why there is no contradiction. Otherwise make necessary corrections that W can be properly considered to be a joint PDF. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 528 Lines 313-15 sentence seems correct, but it is confusing because its intended purpose is unclear. Is it simply intended to point out that the variates tMRE l'ln d LT M are not independent (because the factor S in Eqn 13 depends not ust on tMRE, but also on L TM), so that (by definition) the joint PDF is not Lines 313-320 Rewritten to move the point earlier in the paragraph. the product of the marginal PDFs? Please rewrite or amplify to K::larify the intended meaning. 529 Line 320-321 horizonal axis in Figure 8 is labeled "Equivalent Poisson Rate" (and EPR is indicated in the caption), but the text seems to indicate that this axis represents the random variable CPR, not the estimated value EPR. and his interpretation is reinforced by the fact that the plot is presumably the GDF of a random variable (i.e., CPR). Please review and Line 327 The use of "Rate" has been revised to "Ratio". modify as necessary to make the text and Figure 8 consistent, and to make K::lear the conceptual distinction between CPR and EPR. The same K:;omment applies to Figure 9. 530 Line 320-321 apparently the curve in Figure 8 is a CDF (or the complement of its maximum value should be 1. This is not clear in Figure 8. If in fact he curve does rise rapidly to intersect 1 at zero CPR (and from looking at Figure is slightly modified to clarify the location of the Figure 9 it becomes clear that it does), to avoid any confusion, please Figure H-8 curve as it approaches 1.0, and notes are added in indicate that fact with a modification to the figure or a note in the caption figure EXPLANATION box. 531 Line 335-336 Please explain the meaning of the vertical dashed lines in Figure 9. Lines 344-345 Description added. 532 Line 343 Please review the use of the term "marginal distribution" here. Wouldn't The intended meaning is as the reviewer indicates, a marginalizing on tMRE mean integrating over it. whereas what is proposed delta function on tMRE=t_eqk. Because the weighting is is concentrating the tMRE dependence in a delta function delta(tMRE-done on narrow discrete values for tMRE, a single _eqk) to begin with. so W=p(l TM) x delta(tMRE-t_eqk)? In what sense is it Lines 352-354 column remains across the range of L TM. The reduction rue that "the equality constraint is a form of marginal distribution"? shares in common the idea of reducing a range on L TM-tMRE to a range on L TM alone, but it is not done by integrating, and thus is not a true marginal distribution. The relevant wording has been revised. 533 Line 396 It is a little recursive to say that values of parameters used for Figure 12 Confusion was introduced by the author because of an were fixed to the values used in Figures 9-12. Please consider revising this. Lines 401-404 incomplete editing of the draft. Back reference to Figures 9-12 is removed and the sentence has been reworded 534 Line 407 Figure 13 has not been cited prior to this citation of Figure 14. Please check whether the figure currently labeled 13 should be deleted and figures The former Figure 14 (Weibull) has been moved to K:;urrenlly labeled 14 and 15 should be relabeled t 3 and 14. If so. then the Line 413 Figure 13. A new Figure 14 is added that more directly K;itation at this point in the text should be Figure 13 (and subsequent figure compares the three time-dependent models. This K::itations are already correct). comparison is promised in Chapter t t text. 535 Line 426 would be useful between "principle" and "slip rate". Line 444 Done COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 536 Line 456-457 Please explain the connection between the weighting method implemented The maximum likelihood approach underlies our EPR here and a maximum likelihood perspective. estimation because weighted solutions are extracted using joint L TM-tMRE probabilities. However. we Lines 4 7 4-4 76 reworded to replace the ML mention with a more important observation that the action of the survivor function to cut off right probability space leads to stability of the EPR estimate across recurrence model functional forms. 537 Line 466-467 Please provide references for the cited MFD functional forms. Lines 483-485 Reworded 538 Figure 5 Please correct the following deficiencies in the figure: 1. The caption is inadequate. It shou Id provide additional information, including at least the CV used to generate the plots, the meaning of the circles in the upper right panel, and the meaning of the curve cutoffs in the lower panels. It should also properly indicate the nature of the Figure H-5, Line are not all lognormal distributions, as the caption would 261 Revised. even though they are all quantities derived from lognormal ktistributions. panels are called out by letter (e.g., "Figure 5d") in the text, but they not labeled with those letters. 539 Figure 7 Please indicate in the caption what slip rate was used to generate this l:!xample. what OPE model was used ( Hosgri OPE model of Figure 3?), Figure H-7 Revised what CV was assumed. 540 Figure 8 Please indicate in the caption the meaning of the red stars. Figure H-8 Revised 541 Figure 9 Please define the symbols, either in the legend or the caption or both, as well as stating the meaning of the vertical dashed lines (which do not seem o be mentioned in the text either). Please also improve the figure title, Which is rather cryptic (what does "Four Tmin,LN", mean, for example?). Figure H-9 Revised please review the use of EPR for the title and horizontal axis, and make changes as necessary to ensure consistency with the discussion in he text and with any intended distinction between EPR and CPR. 542 Figure 10 Please write a more complete caption for this figure. Is it based on the Hosgri OPE model? What are the dotted lines in the upper panel? Tmin is in the legend. but not clearly identified there, so it also should probably be given in the caption. Figure H-10 Revised 543 Figure 12 Please improve the caption. At the least, the meaning of the colors should be explained. H-12 Revised 544 Figure 13 rrhis figure may be redundant. Please check whether that is the case and This Figure 13 became Figure H-14. It shows the BPT ktelete if appropriate. H-14 results. 545 Figure 14 Please check whether this figure should be relabeled "Figure 13". H-13 Yes, this figure has become Figure H-13. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 546 Figure 15 Please check whether this figure should be relabeled "Figure 14" and write informative caption (which should include deciphering "BWM"). H-15 Revised, Figure H-15 is correct. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT PPRP COMMENTS AND Tl TEAM RESPONSES, CHAPTERS 1 TO 4 Location Comment Location in Text Number inText1 PPRP Comment for Summary of Revisions to Report Comment Revision General Comments The report is generally well written and comprehensive. Comment acknowledged. The entire The entire text would benefit from a thorough technical report, figures and appendices are edit. This edit would ensure the consistent use of tense being edited by a professional Text throughout the text, maintain the consistent use of the Editor. 1 third person, ensure the consistent use of terminology, remove redundancies from section to section, and correct typographic errors. We have not attempted to provide such a technical edit in this review but have focused on technical justification and clarity. In some cases, where errors are obvious to us, we have noted those. In several instances, the absence of figure captions Figures are produced using the PG&E detracts from the usefulness of the figures. Figure titles Report Style Guide, which requires a are important, but they do not provide the link from the title block. The title block limits the image to the technical arguments being made in the text. length of the figure caption. Where We strongly urge that figure captions be developed for all possible, we have added "Notes" to the of the figures that provide a summary of the salient body of the figure to provide additional elements of the figures that are being presented, and the explanation. key technical conclusions that the authors would like to 2 portray. The fundamental technical arguments and detail will still reside in the main text, but the figures will carry additional meaning when they are accompanied by captions that highlight those arguments. Further, the captions will provide an opportunity for the various panels of a figure to be defined and discussed, without forcing the reader to flip back and forth between the main text discussions and the figure. Figure captioning of the type requested is standard for a report of this kind. 3 We recognize that the SSHAC process allows for the Comment acknowledged. Text has 1 Unless otherwise indicated, paragraphs identified are for the section, rather than on the page cited. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location Comment Location in Text Number inText1 PPRP Comment for Summary of Revisions to Report Comment Revision consideration by the Tl Team of all data, models, and been revised to more explicitly identify methods that exist within the larger technical community, Tl Team judgments and to eliminate all including those that have been developed within a QA "personal communications". environment, the peer-reviewed literature. unpublished reports, or otherwise. A vitally important part of the documentation process is the attribution of those data, models, and methods by exhaustive referencing throughout the report. Thus, many of our comments call for more complete referencing of the technical conclusions and assertions made in the text. It is particularly important to indicate which technical assessments have been taken from other sources (with proper referencing) and which have come from the Tl Team itself. In the hierarchy of sources of information, we consider personal communications to be the least defensible, due to the general inability of the report reader to verify their accuracy. We therefore urge the authors to avoid reference to personal communications if at all possible. If any cited source can be made (e.g., reference to abstracts for presentations at professional conferences, reference to presentations made at the workshops and documented in the workshop summaries, papers that have been accepted for publication but not yet published), that would be preferable to a personal communication. If there is no other reference to cite. please consider whether the technical conclusion being made is vital to the SSC model and whether it can be removed from the report. If the conclusion is vital and a personal communication is the only source of information, please consider adding documentation to the report in the form of an appendix. We recognize the need to develop the report in Comment acknowledged. More explicit 4 installments in order to meet the project schedules; cross-referencing to specific sections however, this precludes our ability at this staoe to provide and subsections of the report is COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location Comment Location in Text Number inText1 PPRP Comment for Summary of Revisions to Report Comment Revision intelligent comments on the accuracy of cross-references. provided. We urge the authors to provide the most specific cross-referencing possible to assist the reader in understanding the technical arguments being made. For example, given the scale of this report and the complexity of the technical issues, cross-referencing is essential to guide the reader in seeing how the evaluation of data has led to the development of the SSC model. As the arguments are developed, links within the text will be needed to refer to the specific sections and subsections of the report where the information lies. Simple reference to an entire chapter is not helpful, but reference to specific subsections will be most useful. Hence, once all sections have been written, it is strongly recommended that a single author read through and edit the document with the appropriate detailed cross-references. Reviewing a report in installments is not ideal but required Comment acknowledged. We in this case. Without seeing how the sections in this understand the need for a final review installment interface with other sections, there is a certain upon completion of the entire report. amount of faith that we must have that the technical data and arguments made in other sections will support the 5 positions taken in this installment. Although the comments made in this round of PPRP review provide a comprehensive review at this point in time. we reserve the right to provide additional commentary on the sections of Installment #1 in the future after we have reviewed later sections of the report. Chapter 1 Section 1.0. Suggest adding " ... ground motion at the site as a Line 41 Text revised as suggested. p. 17, 1st function ... " 6 paragraph, last sentence 7 Section 1.0, Please specify if this SSC report will also be an Line 52 The SSC model and SWUS GMC COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location Comment Location in Text Number inText1 PPRP Comment for Summary of Revisions to Report Comment Revision p. 17, pt attachment to PG&E 2015. model reports will be stand-alone paragraph. reports. 4th sentence Section 1.0, Will PG&E documents (e.g., 2015 and others referred to Line 110 Documents related to the SSC study page 17, in text} be accessible on PG&E/LCI share drive? are available on PG&E website 8 2nd {address provided). paragraph 7th line down Section 1, ." ... was conducted from June 2011 to January 2015. Line 54 Text revised to March 2015 9 Page 17, Please change to February 2015, as this date is more Paragraph realistic. 2, line 8 Section 1, Please include the specific date of the kick-off meeting. Line 54 Text revised as requested. 10 Page 17, Paragraph 2, line 9 Section 1.0, 35 working meetings are identified on page 28 and Table Line 56 Text and Table 3-1 have been revised 11 p. 17, 2nd 3-1. Please clarify. to reflect 36 working meetings. paragraph, line 10 Section 1.1, A careful reading of Chapter 6 of NUREG-2117 shows Lines 72-73, Text revised as requested to show 12 p. 18, pt that the options are accept, refine, or replace. There is no 84,98 "accept, refine or replace". paragraph. "revise." Please clarify that the decision here is to replace. 1st line Section 1.1. Please define ISFSI with first usage. Line 79 Text revised as requested. Page 18, 13 Paragraph 2. Line 3 Section 1.1. Will (in prep) documents be made available-Wooddell et Line 92 The Wooddell et al study will be 14 page 18, al. (in prep); please see General Comments regarding provided in Appendix G to the report. 2nd such citations. paragraph COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location Comment Location in Text Number inText1 PPRP Comment for Summary of Revisions to Report Comment Revision 141h line down Section 1.1, " ... regional GPS data. and several offshore studies and Line 87 Text revised as requested. Page 18, seismicity studies ... " Please indicate what types of 15 Paragraph offshore studies were conducted. Geologic? Seismic? 2, line 10 Section 1.1, Please cite published report(s) and/or journal article(s) for Lines 90-92 Text revised as requested to add 16 Page 18, UCERF 3, and update the Wooddell et al. citation if report reference to Field et al (2013) and the paragraph 2, or paper is published (and if not, cite the section of the Wooddell et al Appendix. Line 12: report where that work is presented). Section 1.1, The presence of new data, models, and methods requires Line 97 Text revised as requested to show that p. 18, 2"d that they be evaluated, as defined in NUREG-2117. They "new data, methods, and models will 17 paragraph, do not necessarily need to be incorporated into the SSC be evaluated and integrated, as last model, particularly if they are not found to be technically appropriate, ... ' sentence defensible. Section This is actually an existing regulation pertaining to license Lines 112-115 Text revised as requested. 1.1.1, 151 conditions. The NRG therefore did not "issue" 50.54(f). 18 paragraph, They issued a request for information pursuant to the p.18, first regulation and related to NTTF recommendations. sentence Section " ... site specific earthquake ground motion" addresses Line 130 The term "addresses" has been 1.1.1. Page should use ... " This statement is unclear. Please clarify replaced by "licensees". 19 19, what is meant by "addresses". Paragraph 2. line 7 Section Coppersmith and Bommer (2012) is not listed in the Chapter 2, Reference in text removed from 1.1.1. Page chapter references section lines 75-76 chapter 1, added to chapter 2, and 20 19, 3rd and 512 cited in chapter 2 references paragraph of section, Line 4: COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location Comment Location in Text Number inText1 PPRP Comment for Summary of Revisions to Report Comment Revision Section Please consider referencing the report chapter that Line 154-156 Text revised as requested. 1.1.2, Page presents the sensitivity studies. 21 19, 1st paragraph of section, 2nd sentence: Section Consider whether "complete is the right word here. Line 152 Text revised. The word "complete" is 1.1.2, Page deleted. 22 19, 1st paragraph of section, line 5: Section In the first bulleted line, are location and geometry the Lines 159-178 Text is okay as shown. The 1.1.2, Page only foci in the identification and characterization of active subsequent bullets describe the 23 19, faults near the site? Consider also kinematics, rates, and additional source parameters Paragraph 1 recency of motion. considered. Section The use of the term "explore implies that some things Lines 161-178 Text revised. The word "explore" is 1.1.2, p. 19, were looked at (explored), but weren't necessary replaced by "capture". 24 second included. For example, exploratory studies are a type of bullet sensitivity analysis. If the intent here is to say that the range of uncertainty was "defined" and/or "included", then consider changing the terminology. Section Please consider the suggestion to reference the report Lines 159-178 Text revised as requested. 25 1.1.2. Page section(s) appropriate to each bulleted item. 19-20, bulleted list: Section "Development of fault "fault rupture models" that... " Line 165 Text revised as requested. 1.1.2. Page Please delete fault. 26 20, 1st bulleted line on paqe 27 Section If this is the first reference to "linked ruptures. complex n/a Terms removed from bulleted item. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location Comment Location in Text Number inText1 PPRP Comment for Summary of Revisions to Report Comment Revision 1.1.2, Page ruptures, and splay ruptures", please define or include a 20, 1st reference to report section or other source where they are bulleted line defined. on page Section Please rephrase, as this is a run-on sentence. Line 171-173 Text revised as requested. 1.1.2, Page 28 20, 3rd bulleted line on page Section Please change "incorporates" to "incorporate" as this Line 174 Text revised as requested. 1.1.2, Page refers to "models" (plural) 20, 4th 29 bulleted line on page Section 1.2, Please correct "strike-slip" Line 209 Text revised as requested. Page 20, 30 Paragraph 1 of section, line9. Section 1.2. Please note typo and clarify number of Tl Team Line 229-231 Text revised as requested. Page 21. members. 31 last paragraph of section, Lines 7-8: Section 1.2. Three of six members four of five members not affiliated -Lines 229-231 Text revised as requested. page 21, 3rd unclear which one? 32 paragraph, 7th line down COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location Comment Location in Text Number inText1 PPRP Comment for Summary of Revisions to Report Comment Revision Section 1.2, The 3rd subphrase "(3) ... new methods and ... " Are you Line 233 Text is okay as shown. New methods Page 21. referring to new data? What new methods were used? include the WAACY model and 33 Paragraph 3D seismic is not a new method, although it is newly "rupture source" modeling approach. 3, line 10. applied to the SSC for DCPP. Please clarify what "fundamentally new methods" were aoolied. Section 1.3, "provides our evaluation" -please specify who "our" Line 244 Text revised to show "Tl Team". Page 21, 1st refers to-the Tl Team? 34 numbered paragraph Section 1.5, The references need to be correctly formatted. For Lines 343-352 Reference list has been edited and 35 pages 23-24 instance, there is a U.S. NRC, 2012 and U.S. Nuclear correctly formatted. Regulatory Commission 2012a, 2012b, and 2012c. Please correct these references here and in the text Chapter 2 Section An opinion is a belief that does not require facts or Lines 82-83 Text revised as requested. 2.1.1, p. 25, evidence. Judgment is the evaluation of evidence to make 36 211d a decision. Suggest replacing "opinion" with "judgment." paragraph, 211d sentence Section 2.2, " ... provided for bringing all members of the project Line 157 Text revised as requested. Page 27, team ... " This is awkward. Please rewrite for clarity 37 3rd paragraph, line 3 Section Please note word repetition. Lines 142-145 Text revised as requested. 2.2.1. Page 38 27, last sentence of section: Section "uncertainty" Consider pluralizing this word. Line 194 Text revised as requested. 39 2.2.3. Page 28, Paragraph COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location Comment Location in Text Number inText1 PPRP Comment for Summary of Revisions to Report Comment Revision 2, line 7 Section Please clarify or correct the apparent conflict between this Line 198 Text revised and updated to show 36 2.2.3, page line ("35 working meetings"} and Section 1.0, paragraph working meetings. 40 28, 3rd 2, Line 11. ("53 Working Meetings"). paragraph of section, Line 2: Section In reference to UCERF, are you referring to UCERF3? If Line 267 Text revised as requested. 2.2.3, Page so, please state. 41 29, Paragraph 8, line 18 Section It would be clearer if Dr. Lettis were included in this list, Line 250 Text revised to add Dr. Lettis. 2.2.3, page e.g.," .. consisted, in addition to Dr. Lettis, of Dr .... " 42 29, last paragraph on page, Line 2: Section Please resolve the conflict between this statement that Line 256 Text revised to show Ms. Hanson 2.2.3, page Ms. Hanson was added after Workshop 2, with the joining the Tl Team following 43 29, last statement in Section 1.4, page 23, line 8-9 on page, that Workshop 2. paragraph says that Ms. Hanson was added "Following Workshop on page, 3". Line 8: Section Please check whether the sentence (stating that the Tl Line 256 Text is okay. Ms. Hanson joined the Tl 2.2.3. page Team remained stable throughout the data integration Team following Workshop 2. 44 29, last and model building process) is strictly correct given that paragraph Kathryn Hanson joined the Tl Team after Workshop 3 (if on page, that is the case}. Lines 11-12: Section Inasmuch as "Mr. AbramsonWard and Dr. Thompson Lines 278 Mr. AbramsonWard and Dr. Thompson 45 2.2.3. page were younger scientists," please clarify whether the use of willfully revised the text as suggested. 30, Line 2: past tense here means they are now elderly scientists. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location Comment Location in Text Number inText1 PPRP Comment for Summary of Revisions to Report Comment Revision Section You might also mention that Dr. Rockwell worked on the Line 307 Text revised as suggested. 2.2.4, Page L TSP in the 1980's 46 30, Paragraph 2, line 14 Section Please consider whether this statement is correctly Line 309 The statement is correct as written. We 2.2.4, page phrased, given that Dr. Day's only other SSHAC Level 3 do not say "ALL individuals". 47 30, experience is concurrent with this SSC study. Paragraph 2 of section, Line 10: Section Should read: "For Workshop 3, the members of the Line 318 Text revised as requested. 2.2.4, Page PPRP ... " 48 30, Paragraph 3, line 6 Section Professor of Geology and Geophysics at Scripps Lines 295 Text revised as requested. 2.2.4, page 49 30, 2nd paragraph, 5 lines down Section For completeness. please also note the PPRP's Line 326 Text revised as requested. 2.2.4. page responsibility to review the Project Plan. 50 31, listed items in 4th paragraph of section: Section Inconsistent usage of periods at the end of each bullet. Line 326-337 Text revised as requested. 51 2.2.4. Page Please make them all the same. 31,bulleted items 52 Section In Figure 2-1, SSC Tl Team Staff Support is indicated by NIA Yes, all of the Tl Team support staff COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location Comment Location in Text Number inText1 PPRP Comment for Summary of Revisions to Report Comment Revision 2.2.5, p. 31, an asterisk as being EEs. Is this correct? shown are considered Evaluator last Experts. sentence Section Of course. the REs did not present "raw" data without Line 363 Text revised as requested. 2.2.6, p. 31, interpretation. The important point is that the REs avoid 53 1st providing their interpretations of the data relative to SSC paragraph, issues. That is the puiview of the Tl Team. line6 Section Please replace "several" with "some." Line 369 Text revised as requested. 2.2.6, page 54 32 1st paragraph 2nd to last line Section Please make Analyst was to "Analysts were Line 388 Text is okay. The project utilized only 2.2.8, page one hazard analyst, Nick Gregor. 55 32, 1st paragraph 2nd line Section Ms. Wooddell is identified as one of the Hazard Analysts, Lines 394 Text revised to remove reference to 56 2.2.8, page but her name does not appear in Figure 2-1 (the project Ms. Wooddell as a hazard analyst. 32, 3rd to organizational chart). Figure 2-1 is okay. last line: Section To avoid confusion of roles. consider adding a statement Lines 371-372 Text revised as requested. 2.2. 7. p. 32. that all participants were made aware of the fact that Lines 383-385 57 last members of the Tl Team were assuming the role of PE for sentence purposes of the workshop. and they would then return to their roles as EE and Els. Section Affiliations were given for the people identified above; Line 394 Affiliations and titles have been added 58 2.2.8. p. 32. consider if they should be provided here as well. Likewise (also line 405) for all participants on the project. line? for Serkan Bozkurt in the next paragraph. Section 2.3. Please consider changing the title to emphasize the Line 417 Title of section changed to "Database 59 Section title: studies rather than the contractors (i.e .. the section is Development and New Studies". about the studies, the contractors being important but COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location Comment Location in Text Number inText1 PPRP Comment for Summary of Revisions to Report Comment Revision subordinate information). Section 2.3, It may be useful to explain either in this paragraph or in Lines 456 Text revised as requested. p.33 Section 2.3.2 what the relationship is between the focus of the CRADA and the studies conducted specifically for 60 Diablo Canyon. It may be important to distinguish the role of the USGS, which conducts research for non-site specific applications, versus 1632 studies that are aimed at reducing uncertainties for the DCPP PSHA. Section 2.3, Please consider rewording this to reflect the fact that you Lines 431-433 Text revised as requested. page 33, are summarizing focused studies done by contractors to 61 2nd to last PG&E (you mention the contractors as part of that sentence: summary, but you aren't merely compiling a list of contractors here). Section Is the Diablo Cove fault considered "potentially active? Lines 443-444 Text revised to delete the Diablo Cove 2.3.1, Page Please refer to subsequent discussion of evidence of fault as potentially active. The intent of 33, line 9 Quaternary activity on this fault. In line 14, is the the text in this section is to be agnostic Shoreline-Diablo Cove fault interaction actually as to whether a fault is active or not, considered in this SSC? but to indicate that these faults were 62 considered and evaluated as part of the SSHAC process. Yes, the Diablo Cove fault and potential intersection with the Shoreline fault was considered, evaluated and judged to be not technically defensible. Section " ... and to evaluate slip rate on the Hosgri fault zone." Line 459 Text revised as requested. 63 2.3.2. Page Didn't Sam Johnson actually "develop new slip rate data 34, line 5 on the Hosgri fault zone."?? Section "lineaments in Estero Bay." What type of lineaments? Line 461-462 Text revised to indicate "seismicity 64 2.3.2. Page Topographic? lineaments". 34, line 8 65 Section "San Francisco State" should read "San Francisco State Line 477 Sentence deleted. 2.3.3, Page University" COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location Comment Location in Text Number inText1 PPRP Comment for Summary of Revisions to Report Comment Revision 34, line 9. Section "San Francisco State" should read "San Francisco State Line 481 Text revised as requested. 66 2.3.4, Page University" Redundancy eliminated by deleting 34, line 3. Also, the second line of this paragraph seems redundant sentence in Section 2.3.3. with the previous paragraph/section. Section It is not clear how the listed studies by Tl Team members Line 484-488 Last sentence is revised to provide 2.3.4, page are to be distinguished from "independent new detailed additional clarification on the use of the 67 34, last studies." If the intent of the sentence is to clarify the scope field reviews performed by the Tl sentence of of Tl Team efforts, please reword. Team. section: Table 2-1, Jan Rietman is stated as being affiliated with FUGRO in Line 477 Rietman is shown as being an Page 35 the text and as a consultant in the table-please make independent consultant, per his 68 consistent. Also, please consider ordering the names request. Tables merged and modified alphabetically-this will eliminate the double naming of and moved to Appendix D -workshop participants, as with Phil Hogan in Workshop #2 (listed summaries. twice). Section The Tl Team members in a SSHAC process are expected Line 500 Paragraph revised as requested. 2.3.5, p. 35, to evaluate ALL forms of data, models, and methods. This 2nd includes data gathered under a QA program, data paragraph provided in peer reviewed publications, and data gathered for other purposes. This is because the experts on the 69 Team are capable of evaluating the quality and applicability of those data. models, and methods. This does not mean that the data are "accepted into the SSHAC process" but that the data have been evaluated according to the SSHAC process. Suggest revising the wording in this sentence. Chapter 3 Section 3.1. In Figure 3-1, there are called "essential steps." To avoid Figure 3-1 Figure modified as requested. 70 p. 38, 2nd confusion with the "essential steps" identified in Chapter 4 paragraph of NUREG-2117. suggest calling these four "components" as done in the text. 71 Section To avoid any perception that the PPRP was actually Line 53-54 Text revised as requested. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location Comment Location in Text Number inText1 PPRP Comment for Summary of Revisions to Report Comment Revision 3.1.1, p. 39, involved in the technical integration process, suggest 4th substituting the term "reviewed," or something similar, for paragraph. "involved." last sentence Section 3.2, Where do these Working Meeting summaries" reside in Line 119-126 There are no formal "working meeting 72 p. 40, last the project records? summaries". This clause is deleted sentence from the sentence. Section Please consider reserving the term "Workshop" for those Lines 130-132 Text clarifies that workshop 0 is an 3.2.1, activities specifically defined as workshops in the SSHAC informal workshop. 73 general NUREG documents (for example, Workshops 1,2, and 3 comment: are structured quite formally and documented thoroughly, including a PPRP feedback letter; this was not the case for the kickoff meetinQ). Section Here and elsewhere, please do not use "etc. List out any Line 158-189 Text revised as requested. 3.2.2, Page other items. 74 41, Paragraph 2, line 9 Section significant parameters and features." Please clarify what Line 199 Text revised to say "seismic source 75 3.2.3, Page is meant and implied here. Issues? Data? characteristics". 42, line 9 Interpretations? What are parameters and features?? " Section Consider changing " ... and input into ... " to " ... and added Line 216 Text revised as requested. 3.2.4. Page to .. " 76 42, Paragraph 1. line 4 Section "overlapping day with the GMC to discuss ... " Do you Lines 233-235 Text revised to clarify the 3rd day of the 3.2.5. Page mean GMC Tl Team? Please clarify. workshop. 77 43, Paragraph 1, line 6 78 Section Please delete "etc." and list out any other items. Line 246 Text revised as requested. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location Comment Location in Text Number inText1 PPRP Comment for Summary of Revisions to Report Comment Revision 3.2.5, Page 43, Paragraph 2. line 10 Section "Several of the working meetings were observed ... " This Line 300 Sentence deleted. 3.2.6, Page is redundant with the previous paragraph -already 79 44, stated. Paragraph 3, line 13/14 Section " ... used to form the basis development of ... .. This Lines 322-325 Sentence clarified as requested. 3.2.7, Page statement is unclear. Please clarify 80 45, Paragraph 3, line 5 Section Please indicate where the summary and PPRP letter are Line 310 Reference is given to the workshop 3.2.7, Page located. Appendix D. PPRP letter and response 81 45, are kept in the project files, and are not Paragraph planned to be part of the submittal. 4. last line Section Are these the same as the WM Summaries identified on Lines 355-359 There are no formal working meeting 3.2.8. p. 46. page 40? summaries. This sentence is deleted. 82 1st paragraph, last sentence Section Please delete "etc." and list out any other items. Line 392 Sentence revised as requested. 3.2.9. Page 83 47, Paragraph 2, line 9 84 Section " ... the final model in light of the ... " Consider changing Lines 427-429 Sentence is clarified as requested. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location Comment Location in Text Number inText1 PPRP Comment for Summary of Revisions to Report Comment Revision 3.2.10, Page "in light of" to "using" to improve clarity. 48, Paragraph 1, line 6 Section Please add "fault" after "Hosgri", as it is a formal name. Line 434-437 "Hosgri" text removed from the revised 3.2.10, Page sentence. 85 48, Paragraph 2, line 7 Chapter 4 Section 4.1, Please define FSAR if this is the first usage of this term. Line 39 Modified as suggested. 86 Page 51, Paragraph 4, line 2 Section "proposed Diablo Cove fault" -Is it a fault, or not? Line 68-69 The term 'proposed' has been deleted 4.2.1, Page Please clarify "proposed" 87 51, last line and sentence revised. Section The bulleted items do not have a parallel sentence Line 72-73 Text revised to correct sentence 88 4.2.2, Page structure with the intro. Each should read correctly after structure as suggested. 52, bulleted " ... .included:" items Section University of Berkeley-University of California, Line 100 Revised to clarify 4.2.2, page Berkeley? 89 52, 2nd paragraph, last line Section The first bulleted paragraph is confusing. Please rewrite Lines 108-119 Text revised to clarify. 90 4.2.3, Page for clarity. 52, 1st bulleted item Section If this is the first occurrence of the acronym LESS, please Lines 176-181 Text revised and reference to LESS 91 4.2.4, page define (it may be used freely thereafter, since it does deleted from this paragraph. 53, 1st COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location Comment Location in Text Number inText1 PPRP Comment for Summary of Revisions to Report Comment Revision paragraph of appear in the acronym table). Also, suggest putting "New" section, Line 4: prior to Offshore Section "Report" is repeated, but the acronym does not have an Line 215-216 The extra "report" has been removed. 4.3.1, Page R. Is report part of the official title? Not clear. 92 54, Paragraph 1, line 6. Section "Low-Energy Seismic Survey" and "Onshore Seismic Lines 235-237 Capitalization in the revised sentence 4.3.1, page Interpretation Project" should be written with initial capital was recommended by technicial editor. 55, 3rd letters. 93 paragraph of section, last 3 lines of section, Section If this is the first occurrence of the acronym HFZ, please Line 259-260 Revised as suggested 4.3.1.1, define (It appears in the acronym table, so it may be used 94 page 55, 1st freely thereafter). paragraph, Line 4: Section Non-parallel structure and confusing. Suggest" ... to the Lines 335-338 Agreed. Sentence was revised 4.3.2.1, Hosgri fault zone, were spaced -800 m apart (locally 400 (subdivided into two sentences) to 95 Page 56, m) along an -94 km-long portion of the Hosgri fault zone, clarify and correct. Paragraph and crossed the fault zone 121 times." 2. lines4 and 5 Section Check spelling of "transect" Line 353 Spelling corrected. 4.3.2.1, 96 Page 57, Paragraph 3, line4 COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location Comment Location in Text Number inText1 PPRP Comment for Summary of Revisions to Report Comment Revision Section "available at CSUMB (2010)." Is this a published source? Line 358 Reference added. The site was 4.3.2.1, It is not in the listed references. Please include. Page 57, accessed in December 2014 to confirm Paragraph that there were no newer updates. Text 4, line4 was modified to reflect 2014 reference citation. 97 California State University, Monterey Bay, Sea Floor Mapping Lab (CSUMB), 2012. Multibeam echosounder (MBES) data for the California Central Coast. Available at http://seafloor.csumb.edu/SFMLweb DATA_c.htm (accessed December 2014). Section Sentence is incomplete; please check and correct. Lines 355-356 Sentence corrected 4.3.2.1, 98 Page 57, 5th paragraph of section, 1st sentence: Section "tomoDD velocity model" is very specialized jargon. in the Line 381-382 Sentence revised as suggested 4.3.2.2, sense that "tomoDD" is the name of the computer page 57, 1st program that implements a particular analytical method. 99 paragraph of Please consider rewording, either simplifying to "seismic section, Line velocity model", or to something that references the 3 underlying analytical method, e.g., "seismic velocity model based on double-difference tomoaraohv". Section Suggest moving "by" after (1) to be consistent with rest of Lines 404-408 Sentence revised to provide 100 4.3.2.3, paragraph. consistency in list Page 58, COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location Comment Location in Text Number inText1 PPRP Comment for Summary of Revisions to Report Comment Revision Paragraph 1 Section This sentence is confusing. " ... are incorporated into the Lines 431-432 Sentence was corrected to clarify and 4.3.2.4, characterization of the Irish Hills-Estero Bay Local Areal remove extraneous text. 101 Page 58, Source Zone Irish Hills-that includes the Irish Hills." Paragraph 2 Please clarify. Section Reference section gives author name as Murray-Line 450 Text modified to cite name as shown 4.3.2.5.1, Moraleda, which is not consistent with the citation in this on the report (Murray-Moraleda). Later 102 page 59, 1st paragraph. Workshop presentation correctly cited paragraph, as "Murray" Line 1: Section Rinconada fault2??? Are there two Rinconada faults? Is Line 470-471 Typo corrected in revised text. 4.3.2.5.3, this a typo? Please clarify. 103 Page 59, Paragraph 1, line 6 Section The citation is consistent with the reference section entry, Line 450 Text and reference citation were 4.3.2.5.1, but not with the citation at the beginning of the paragraph. modified (see response to #102) to be 104 page 59, 1st consistent. paragraph, Last line: Section "San Luis/Pismo" is written "San Lui-Pismo" in the list of Lines 623-624 The term has been changed to San 4.3.2.8, abbreviations and acronyms. Luis-Pismo in the revised text 105 page 61, 1st bulleted item: Section Please rewrite this paragraph for clarity. Lines 653-658 Section 4.3.2.9 was modified 4.3.2.9, throughout to clarify the objectives of 106 Page 62, the research and to cross reference Paragraph 1 more specifically to where the new data and information used to evaluate seismic sources was discussed. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT PPRP COMMENTS AND Tl TEAM RESPONSES, CHAPTER 5 Location PPRP Comment Location Summary of Revisions to Report inText1 in Text Comment for Number Comment Revision Chapter 5 Section 5.2, Both SYRF and SYF labeled on Figure for Santa Ynez No change Figure 5-1 is correct. The Santa Ynez 107 page 69 River Fault. Please make consistent. required River fault and Santa Ynez fault are Figure 5-1 two different faults. Section 5.2, States that the contemporary plate boundary is a zone of Lines 95-96. No change; text is correct. Both strike Page 67, strike slip faults and transpressional deformation, but slip and reverse/thrust faults may occur paragraph 1 , wasn't the San Simeon earthquake purely thrust? Plus, Please note in a transpressional tectonic setting. lines 4-5 two of the structural models have the San Luis Bay and that the Los Osos as thrust faults. Is this statement correct? subheading of 108 Please clarify. 5.1 for Introduction was removed and Section 5.2 in previous draft is now Section 5.1 Section 5.2, In the preceding section, the region is referred to as The preceding sentence states "at the Page 68, " ... zone of right-lateral strike-slip faults ... ", whereas many Lines 96-97 latitude of Diablo Canyon" and is not Paragraph of the faults shown in Figure 5.1 are left-lateral or oblique referring to faults within the Western 109 2. line 1 left lateral (Santa Ynez. Lion's Head, Casmalia. etc.). No change Transverse Ranges. Also, the Lion's Please clarify. required Head and Casmalia faults are either reverse or right reverse faults (e.g .. the 1980 Casmalia earthquake). Section Please add a reference for these ages: "(approximately Line 126 The ages shown refer to the age of the 5.2.1. Page 200 to 66 Ma)". 66 Ma may be a bit young for the Jurassic and Cretaceous Period, 110 68, cessation of subduction-related volcanism. as Sierran because this is the time interval Paragraph volcanism and pluton emplacement shut down by about discussed. For clarity, we have deleted 1, line 1 80 Ma, and it was even earlier in the southern California reference to the age. 1 Unless otherwise indicated, paragraphs identified are for the section, rather than on the page cited. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location PPRP Comment Location Summary of Revisions to Report in Text1 in Text Comment for Number Comment Revision Peninsular Ranges (95 Ma). Are you suggesting that Cessation of volcanism in the subduction ceased at 66 Ma? Clearly, as stated earlier, Cretaceous is not considered relevant the spreading ridge intersected the trench at about 28 Ma to the tectonic setting at Diablo and flat-slab subduction was occurring after-80 Ma Canyon. Subduction of the Farallon (hence, the cessation of Sierran volcanism}. This section Plate beneath North American plate would benefit from additional supporting discussion and continued well into the Cenozoic. improved referencinQ. Section Would it be helpful to mention the seismicity that is also Lines 175-176 Text revised as requested. 5.2.2, p. 69, projected on to the cross section in Figure 5-4? 111 3rd paragraph, line8 Section Please provide more information or reference to support Lines 176-178 Text revised to state "top of the imaged 5.2.2, page "surface slab does not appear to be disrupted by crustal slab appears continuous and does not 69 faults". Is this based on microseismity?? appear to be vertically offset or 112 3nd disrupted ... " paragraph 10 lines down Section Please provide the basis for this interpretation or make Lines 178-179 Reference is made to Sections 5.1.5 5.2.2, p. 69, reference to a section of the report where the issue of the and 7.2.1 for assessment of 3rd top of the slab relative to the Hosgri fault is discussed seismogenic thickness. 113 paragraph. further. second to last sentence Section Onderdonk (2007) is cited but does not appear in the Line 1203 Onderdonk (2007) is added to the 5.2.3. page references section. reference list. 114 70, 2nd paragraph of section, Line 7: 115 Section It is stated here that subduction ceased 22-20 Ma at the Lines 135-209 Text revised to clarify timing. and 5.2.2, Paoe latitude of DCPP, but it is earlier stated that the spreadinq location of subduction. Reference to COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location PPRP Comment Location Summary of Revisions to Report in Text1 in Text Comment for Number Comment Revision 69, 3rd ridge contacted the subduction zone "directly south" of specific age is deleted. Paragraph, DCPP. which would imply a timing close to 28 Ma. In line7 contrast. figure 5-3 suggests that contact occurred near present-day Los Angeles. Please clarify or correct. Section There is a lot of detail with no referencing, and alternative Lines 135-209 Text modified to provide additional 5.2.2, Page interpretations have been proposed in the literature. For clarity. The reference to Gulf of 69, 2nd, instance, the notion that the main plate boundary jumped California is deleted. Much of the 3rd and 4th inland at 5 Ma is contradicted by many studies. There discussion in these paragraphs is from Paragraphs was clearly part of the main plate boundary already inland Atwater and Stock ( 1998). 116 by 12 Ma -hence the Miocene activity of the San Gabriel fault and the development of Ridge Basin (Crowell refs). Oskin and Stock argue for an earlier opening of the Gulf, as does Fletcher, and that the "proto-Gulf" is really no different than the modern Gulf of California, except where the locus of extension occurred. Please provide complete referencing in these paragraphs. Section "full plate motion of 30 to 35 mm/yr during the late Lines 286-314 The change in plate rate and 5.2.2, Page Miocene." According to many references, the full plate orientation is directly from Atwater and 70, 5th motion during the late Miocene was no different than it is Stock (1998). The change in rate 117 Paragraph, today --52 mm/yr. Please provide additional justification occurred about 12 Ma; the change in line2 and references, and specify the timing of the increase in plate orientation occurred about 8 Ma. rate ( 12 Ma?) Additional text has been added for clarification. Section Please complete the citation for Atwater (2011) or provide Line 138 URL has been added to the reference; 5.2.3. page an online URL. and sentence has been moved to the 118 71, 4th introduction paragraph of Section paragraph. 5.1.2. line4 Section If the San Miguelita and Edna faults were active at this Initial As discussed further in this Section. 5.2.3. page time with lateral slip. the model requires them to be left-comment in the sense of lateral slip on these faults 119 71, 4th lateral. Is this model consistent with observations? not changed. is poorly constrained by data. The text paragraph, Please elaborate. Discussion of describes two "models"; the model by line8 models in Luyendyk (1991) which shows these lines 272-285 faults as dextral slip, and the model by COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location PPRP Comment Location Summary of Revisions to Report in Text1 in Text Comment for Number Comment Revision Wilson et al (2005) which shows these faults as first left lateral. followed by right lateral. Section Please consider whether the topic of "early sinistral Lines 272-285 The paper by Wilson et al (2005) 5.2.3, page transtension between blocks and later dextral presents a palinspastic reconstruction 71, 5th transpression" is discussed in Wilson et al., 2005. The of the WTR and Los Osos domain area paragraph, paper is focused on the correlation of volcanism and slab in Figure 8. This figure shows an initial 120 last windows and does not appear to address the topic period of left lateral faulting followed by sentence. identified. If it does not, please provide a proper citation right lateral faulting as described in the for this concept. Also, please explain why many of the E text. to NE-striking faults (Santa Ynez, Lions Head, etc.) continue to have late Quaternary left lateral or oblique LL motion. Section Here it is stated 6.3 to 4.7 Ma. Earlier 5 Ma is used. Line 299 Text revised to say 5 Ma, consistent 5.2.3, page Please be consistent and provide a reference for this with the model from Atwater and Stock. 72, 6th timing. 121 paragraph, line 9 from top of page COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location PPRP Comment Location Summary of Revisions to Report in Text1 in Text Comment for Number Comment Revision Section Please provide a reference for the statement that rotation Lines 327-332 The text is modified to show a Tl Team 5.2.4, Page in the WTR has stopped. This is a key issue as it affects assessment that the rotation has 72, expected motion on W-NW striking faults in the Santa slowed, in part supported by Marshall Paragraph Maria basin province (Los Osos domain) -should see et al. (2013). 1, line 3 continued left-lateral oblique slip if rotation continues. At least some faults remain active, and Holocene left-lateral has been demonstrated on the Santa Ynez fault. 122 COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location PPRP Comment Location Summary of Revisions to Report in Text1 in Text Comment for Number Comment Revision Section Please replace Carreaga with Careaga Line 325 Text revised as requested. 5.2.4, page 123 72, 1st paragraph 3rd to last line Section What sense of strike-slip? -please indicate. Within the Lines 348; As defined by Lettis et al (2004), the 5.2.5, Page Los Osos domain, the Shoreline fault is presumed to be lines 334-362 Santa Ynez fault is within the WTR, 73, right-lateral based on seismicity and obseived offsets, and is not part of the Los Osos domain. Paragraph whereas the San Ynez fault is left-lateral in the Holocene. Furthermore, the fault strikes east-2, line 4 Other faults, such as Casmalia, Lions Head, Santa Ynez northeast, in contrast to the northwest-River faults, may be left oblique in terms of overall striking faults of the Los Osos domain. 124 displacement, but Holocene slip and kinematics is not The text is revised to indicate faults well-documented. Please explain the inter-relationship of within the domain accommodate these structures and how they can be right-lateral near "dextral" slip and to provide additional the Hosgri and left-lateral farther inland. clarification. The Tl Team judges the Casmalia, Lion's Head and Santa Maria River faults to be either reverse or right-reverse faults. Section Here it is stated that faults in the Los Osos domain are Lines 363-368 The text states that the eastern and 5.2.5, Page dextral or oblique. Does this include the Santa Ynez and western boundaries of the domain are 73, other sinistral faults? These relationships should be marked by dextral faulting. The text of Paragraph explained. It is stated later that the San Luis Bay fault is the previous paragraph is modified to 3, line 2 reverse to left oblique based on kinematic indicators. clarify that faults within the domain are 125 Please provide clarification. interpreted to accommodate reverse, right-oblique, or dextral slip. The rake of the San Luis Bay fault is assessed to be dominantly reverse with minor uncertainty in either direction {Section 8.6). Section Here the concept is introduced of continued clockwise Lines 379-381 In all alternative models, the 126 5.2.5, Page rotation of the WTR. If correct, this could cause a contemporary sense of slip on faults in 74, component of left slip on all of the faults in the Los Osos the Los Osos domain would be reverse Paraoraph domain, as thev are beino extruded to the NW. How does or dextral-reverse slip. Text is modified COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location PPRP Comment Location Summary of Revisions to Report in Text1 in Text Comment for Number Comment Revision 3, 3rd this work -please explain. to provide additional clarification. bulleted item Section Please provide a reference to support the last line of this Line 394-395 Reference added {Lettis and Hanson, 5.2.5, Page paragraph, which starts: "Evidence for downdropped or 1992) 74, static ... " 127 Paragraph 4, last line Section Please provide a reference for the statement that the San Lines 409-415 References provided {Lettis et al, 1994; 5.2.5, Page Miguelito, Edna, and Pismo faults do not deform 2004 ). Additional text added to clarify 128 74, Quaternary deposits. Also, please specify where -the location. Paragraph Edna may not be active in the Irish Hills, but may be 6, line 2,3 active to the east. Section If the Los Osos domain is undergoing transpressional No change The Tl Team considered this issue and 5.2.6, Page dextral shear, consider whether this would preclude judges that continued rotation of the 75, opening shortening due to continued rotation of the WTR. WTR, if occurring, would impose a 129 paragraph northeast-directed strain superimposed on the more regional plate margin strain, which has a similar shortening direction. The two do not seem incompatible. Section Please explain why only two solutions are shown for the Figure 5-11 Notes are added to Figure to provide 130 5.2.6. Figure HASH data. Are there sufficient data for more solutions? additional information {criteria for 5-11 minimum events per cell). Section This appears to be a minimum rate based on data (red Lines 514-522 A new reference is added {DeMets et 131 5.2.6 Figure dashed line). Please provide more explanation on how the al, 2014) which refines the slip rate 5-13 budget was determined. budgets and further describes how the geodetic rate was determined. Section Please check spelling of Zheng (isn't this Yuehua Zeng?) Line 469 Text revised as requested. 132 5.2.6. page 75, 2nd bullet COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location PPRP Comment Location Summary of Revisions to Report in Text1 in Text Comment for Number Comment Revision Section Lewandowski and Unruh (2014) is not in the references. Lines 465 and This is a workshop presentation, not a 5.2.6, page 1142 published reference. Text revised for 133 76, 2nd clarity and citation added. paragraph of section, Line 1: Section DeMets (2012) is not in the references. Lines 476, Clarification of 2012a, 2012b added to 5.2.6, page 481, 1021-text; references added. 134 76, 2nd 1027 paragraph of section, Line 4: Section d3/s1 could be mistaken for a ratio, so please consider Line 510 Text revised to say d3 or s1. 5.2.6, page stating this differently. 76, 2nd 135 paragraph of section, 4 lines from end: Section Please indicate how the cited results differ from published Lines 514-522 The results are modified to be 5.2.6, page work of DeMets (2012), and state the basis for those consistent with published results and 76, 3rd differences (or reference the relevant part of the report). the DeMets et al. 2014 reference has 136 paragraph of been added section, 2nd and 3rd sentences: Section Annotations need to be rotated. also OWH has a p = 1.1 Figure 5-15 Figure modified as requested. Yes, 137 5.2.6 Figure mm/yr? NeoKinema results show a shortening 5-15 rate of 1.1mm/yr on the OWH. Section 5.3. Since the sensitivity results are being used to limit the Lines 563-565 Reference is made to sensitivity 138 Page 77. 1st selection of faults for discussion. please provide a analyses in the Shoreline fault report sentence: reference to somewhere in the report where those (PG&E, 2011 ), Workshop 1 (Wooddell, sensitivitv studies are documented. 2011 ), and Chapter 14 of report. 139 Section 5.3, Consider whether it would worthwhile in this introduction Lines 574-580 Text is modified as requested to COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location PPRP Comment Location Summary of Revisions to Report in Text1 in Text Comment for Number Comment Revision p. 77, pt to discuss the concept of defining each fault according to indicate that this is a site-specific paragraph its characteristics along the reach closest to the site. It study. could be important to remind the reader that this is NOT a regional fault characterization {e.g., UCERF3), but a site soecific SSC model. Section "The model results showed more evidence for northeast-Lines 546-551 NeoKinema discussion remains brief. 5.2.6, page southwest directed contraction between the Los Osos Important element for hazard is to 77, 4th domain (east of the Oceanic-West Huasna fault) and the provide the Hosgri slip rate estimate. Tl paragraph, 9 San Andreas fault than within the Los Osos domain itself. Team considers that exploring deeper 140 lines down "Please provide additional discussion about the model as into NeoKinema (e.g., how faults are it appears to be different from other models. constrained to slip; how they are initially parameterized) would be distracting to the streamlined presentation of results. Section 5.3, "active and potentially active" Please provide Line 576 Text modified to delete "active and page 77, 1st criteria/definitions for these terms. potentially active". 141 paragraph, 11 lines down Section Two alternative models are presented, but the wording is Lines 595-605 Text modified as requested. 5.3.1, Page highly asymmetric. The first-cited references "interpret 142 78, 1st recently acquired offshore seismic reflection data to show, paragraph of ... "whereas the latter-cited references "show" the section, Line contrary. Please reword to be consistent with the 7 to 13: statement that these are alternative models. Section "Possible Hosgri fault zone dip angles are shown on Figure 5-17 Figure corrected as requested (please 143 5.3.1. figure BB'." BB' should be AA'. note that this is Figure 5-17) 5-16 Section "San Luis/Pismo block" is written as "San Luis-Pismo Line 618 Text revised as requested. 5.3.1. page Block" in the list of abbreviations and acronyms and in 144(a) 78, 2nd many other places in the report. paragraph of section, Line 10: COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location PPRP Comment Location Summary of Revisions to Report in Text1 in Text Comment for Number Comment Revision Section 'These intersecting faults include the Los Osos, Lines 648-656 All of these faults do, in fact, intersect 5.3.1, Page Shoreline, Casmalia and Lion's Head faults." This seems with or merge with the Hosgri fault 79, to imply that all of these faults exhibit similar kinematics, zone, and thus in some way will Paragraph but that is certainly not the case. The Casmalia and influence slip rate on the Hosgri fault 4, line4. Lion's Head faults are similar to the Los Osos in that they zone. The Casmalia fault is not a left exhibit a large reverse component, but their sense of oblique slip fault. Chapter 8 will be 144(b) lateral motion is unknown, and in section 8, the Casmalia modified to eliminate this mis-fault is inferred to be left oblique to reverse. Please clarify representation. As described in the known sense of slip on these faults, as their sense of Chapter 7, depending on the slip may control the validity of tectonic models, and alternative fault geometry model whether the current transpression I shortening is the (FGM), sense of slip on the Los Osos result of continued rotation of the Transverse Ranges, or fault varies. In all models the Shoreline some other mechanism. fault is strike slip and the San Luis Bay fault is reverse. Section Refers to the Casmalia and Lion's Head faults as reverse Line 648-664 Paragraph removed, as subject matter 5.3.1, Page to reverse oblique. Please indicate the sense of oblique was intruding on Chapter 8. Summary 80, slip, if known (LL or RL) and provide references. statement that changes in Hosgri slip 145 paragraph 7, rate at fault intersections is sufficient line 3 for Chapter 5 scope. Reverse slip of the Casmalia fault is documented in Lettis et al., (2004) Section "southeast" should be southwest. Line 685 Text modified as requested. 5.3.2, page 146 80, 1st paragraph, 6 line from bottom Section Consider breaking up this very long paragraph. Line 717 Text modified as requested. 147 5.3.3. p. 81. znd oaraaraoh Section San Miguelita fault not labeled on figure. Figure 5-16 Figure modified as requested. 148 5.3.3 Figure 5-16 COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location PPRP Comment Location Summary of Revisions to Report in Text1 in Text Comment for Number Comment Revision Section Provides the inferred dip of the SLB fault of-75 degrees Line 737 This comment is removed from 5.3.3, Page and refers to Chs 8 and 9. It is difficult here, and Chapter 5 (Seismotectonic setting). 149 81, last elsewhere, to confirm critical cross-referenced material The PG&E (2014) interpretations of the paragraph of without it in hand. Please provide referencing to specific dip of the San Luis Bay fault will be section, last sections of the report when they are available. assessed in Chapter 7 line Section Elsewhere "catalog" rather than "catalogue" is used. Line 790; This section has been removed from 150 5.4.1, p. 83, Please be consistent. Appendix F Chapter 5. This comment will be noted title during review of Appendix F Section The terminology for the areal zones does not seem to Figure The figure in question has been 5.4.1., page agree with Figure 5-20. In the latter, the innermost zone is removed removed from Chapter 5. This is 151 83, 1st labeled "Areal Source Zone," not "Local Source Zone. discussed in Chapter 13. The paragraph, Please clarify and intended distinction, or make them terminology has evolved; current is 1st consistent. "Local areal source zone" sentence: Section Consider adding a short phrase (or a specific reference to Chapter 13 This section has been removed from 5.4.1, page another section of the report) to define what is meant by Chapter 5. The comment is addressed 152 83, 1st "gridded seismicity rates." in Chapter 13 paragraph, Line 4, Section Please provide a reference to the report section where the Chapter 13 This section has been removed from 5.4.1, page cited sensitivity analyses are documented. Chapter 5. The comment is addressed 153 83, 1st in Chapter 13 paragraph of section, last sentence: Section Please specify that this is "structural" frequency (and not Chapter 13 This section has been removed from 5.4.1. p. 83. annual frequency). Chapter 5. The comment is addressed 154 1st in Chapter 13 paragraph, last sentence 155 Section If this is the first use of the acronym. please define it (it Appendix F This section has been removed from 5.4.1, page may be used freely thereafter, as it does appear in the Chapter 5. This comment will be COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location PPRP Comment Location Summary of Revisions to Report in Text1 in Text Comment for Number Comment Revision 83, 2nd acronym table). addressed in Appendix F paragraph of section, Line 2: Section It would be helpful for references to other parts of the Chapter 13 This section has been removed from 5.4.1, page report to be specific as to section number. Chapter 5. Chapter 13 provides all the 83, 2nd required information on seismicity rates 156 paragraph of in aerial sources so no internal section, first references are necessary. listed item, last line: Section To avoid confusion for the reader unfamiliar with the Line 811-814 Text modified as requested. Please 5.4.2, page region, you might consider noting parenthetically that, note that the subheading has been 157 84, 1st while similarly trending to the Los Osos, has an opposite removed, and this is now just Section paragraph of dip direction. 5.3. section, last sentence: Section The wording leaves the confusing initial impression that Line 815 Text modified as requested. 5.4.2, page the topic of the paragraph will continue to be the San 158 84, 2nd Simeon Earthquake rather than the Lompoc Earthquake paragraph. ("San Simeon" is the sentence subject, whereas "Lompoc" 1st appears in a prepositional phrase). Please consider sentence: rewording this. Section The meaning of "is considered in terms of' is not clear in Lines 831-838 Text modified as requested. 5.4.2. page this context. If you mean. for example, that the available 159 85, 2nd mission records (etc) place some bounds on the timing of paragraph of the most recent event (as the subsequent sentence section, Line indicates). please consider using some more direct 2, wording. Section The phrase" ... more northwesterly compared to the Lines 866-87 4 Text revised to clarify that although the 5.4.2. page more northwesterly ... "may have a typo in it. Please Hosgri focal mechanisms strike north-160 86, 1st check and correct or clarify. northwesterly, they strike "more sentence on northerly than the northwest-striking the paoe focal mechanisms directly east ... ". COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location PPRP Comment Location Summary of Revisions to Report in Text1 in Text Comment for Number Comment Revision Section 5.5, Please include in observation 2 a brief indication of how Lines 886-888 Text modified as requested. 161 page 86, 3rd the San Simeon Earthquake supports the transpressional line after the model (as you already do in the cases of observations 1, list: 3 and 4). Section 5.5, The sigma_1/d_3 could be confused for a ratio, so please Line 889 Text modified as requested. 162 page 86, 4th restate to remove the ambiguity. line after the list Section 5.5, What is the red star shown in panel (a) of the figure? Figure 5-25 Figure is simplified to show only one 163 p. 86, 2"d Consider re-sequencing the discussion here to be sketch of the transpressional shear paragraph consistent with panels (a) then (b) of the figure, or reverse tectonic model. Red star clearly labeled the panels in the fiQure. and in explanation as the DCPP site. Section 5.5, These paragraphs describe two models on the styles of Lines 893-918 Text is modified to provide more clarity Page 86,last active deformation in the DCPP region, but both appear to and distinction between the two two be essentially the same in that the Hardeback models. paragraphs transpression model shows pure shortening on the on page Oceanic, Los Osos, San Luis Bay, Casmalia and Lion's Heads faults (in her figure), but so does the NE-SW-164 directed crustal shortening model of Lettis et al. (1994, 2004). How these models are distinguished is not clearly presented. Please clarify. Presumably the transpression model includes lateral slip on some or all of these faults, but if so, please explain why the Los Osos fault in the OV model is RL oblique reverse. whereas the San Luis Bay. Casmalia and Lion's heads faults are believed to be LL oblique reverse to reverse. Figure 5-2 The model works until about 80 Ma, after which the slab Figure 5-2 is a schematic flattened due to subduction of buoyant crust, producing representation to show how rocks of the Laramide Orogeny. More relevant to DCPP is the the Franciscan and Great Valley 165 configuration that was frozen in place in the late sequence were deposited, and has not Oligocene I early Miocene, presumably with a relatively been modified. The text is modified to flat subducting slab. Please provide a discussion of this provide additional explanation and configuration. clarity of the Cenozoic plate configuration. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location PPRP Comment Location Summary of Revisions to Report in Text1 in Text Comment for Number Comment Revision Figure 5-18: The orientation of the various cross-sections is not clearly Figure 5-18 Note added to figure to hopefully clarify 166 explained in the figure or caption. tie between maps {a to c) and sections {d to f) Figure 5-21: Legends are very difficult to read, especially in panel (b). Figure 5-20 Figure modified as requested. 167 {note change in Figure# COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT PPRP COMMENTS AND Tl TEAM RESPONSES, INSTALLMENT #2

GENERAL COMMENT

S AND CHAPTER 6 Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision General Comments 259 Overall, the chapters that comprise Installment #2 are well written and Comment acknowledged. We have been working with a provide the necessary documentation for several elements of the SSC technical editor and are striving for consistent, specific model. As noted in Installment #1, the text would benefit from a internal referencing. comprehensive technical edit to ensure consistency in the usage of various terms, tense, third person, etc. Such an edit would also allow for more specific internal referencing to other sections of the report. Suggested edits are provided in these comments, but they are not exhaustive. 259 As noted in the PPRP comments for Installment #1, it is strongly We are committed to using the PG&E title block. Each recommended that figure captions be developed for every figure to assist figure has a title. Additional explanation (i.e., the the reader in understanding the salient points of each figure. Title blocks information that would be presented in captions for a and notes are helpful, but they often do not adequately convey the publication) will be presented in notes on the figure. The messages that the figure is intended to convey. notes can be elaborated into more explanatory descriptions where necessary. 260 Throughout the text, the terms "SSC" and "SSC model" are used Comment acknowledged: use of these terms will be interchangeably. Common usage would dictate that the elements of the checked throughout the report. SSC model should be indicated as such, and that the activity of characterizing seismic sources should be termed SSC. Editing the text for consistent usage is recommended. CHAPTER 6-Seismic Source Characterization Overview 261 Line 14 Please check whether "piecewise planar" would better convey the Lines 14 and 37 Edit made as suggested. intended meaning here and on Line 33. 262 Line 20 Please state, in some quantitative terms, the threshold to be considered to Lines 20-21 Defined approximately as contributing a few percent or "contribute significantly." more to total hazard at relevant frequencies and hazard levels. 263 Line 28 If this is the first usage in the report of the terms **maximum earthquake" Lines 30-32 This is first usage of terms. Definitions provided as and "floating earthquakes", please define or indicate the subsequent requested. section of chapter 6 in which the definition will be given (they are defined on Lines 177-179, for example). Otherwise provide a reference to the previous report section where they were defined. 264 Lines Please explain difference between seismogenic or potentially Lines 38 to 44 Potentially seismogenic distinction removed; 34-35 seismogenic. seismogenic fault is defined. 265 Line 36 Please provide more detail regarding sufficiently active. Presumably this Lines 38 to 44 The sentence in which the term 'sufficiently active' was relates to recurrence rates. used has been replaced by more detailed discussion of criteria used to idenitify seismogenic faults. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 266 Line 38 References to depth here, and in several other places in the chapter, are Revised to be 'depth extent' ambiguous. Please establish, in each case in which it matters, whether Line 61 the reference is to depth to top, depth to bottom, or some other quantity (e.g .. depth extent). 267 Lines Please consider rephrasing to the following -Key data from the DCPP Addressed in Chapter 11 comment 43-44 region are needed for fault slip rates and the lime since the most recent Chapter 11 earthquake 268 Line 46 Non-specific or non-specified? Line 70 Revised to non-specified 269 Lines Please cross reference where hazard sensitivity studies show that the Chapter 11 comment 53-55 SAF has only a small effect on hazard. 270 Line 62 Please provide a more specific reference (section number and figure Chapter 11 comment number(s)). 271 Line 63 "fault" should be plural Line 86 Text revised as suggested 272 Line 63 Please show/reference lngley site on a figure. Chapter 11 comment 273 Line 68 "Recent historical" seems redundant, especially for California as we have Line 91 "Recent" has been deleted such a short historical record. Are you implying there are "older historical" earthquakes? 274 Lines It is recognized that the conclusions presented in these paragraphs Chapter 11 comment 57-88 regarding recency, displacement per event, and recurrence intervals are summaries of the conclusions drawn elsewhere. However, the reader would benefit from specific references to the locations in the report andfor the primary references where the data have been evaluated and the conclusions and uncertainties have been developed. 275 Lines "Selected historical ruptures that we considered in developing both Fault Lines 101-102 Text revised as suggested 76-79 Geometry Models and rupture sources for these fault sources (discussed below in Sections 6.3.1and6.3.3, respectively) are listed in Table 6-1." Please move parenthetical phrase to end of sentence. This occurs many places in the text and ii would make the document flow better if they were at the end of the sentence where possible -see below 276 Table 6-One other well-studied earthquake to consider in this table is the 1999 Line 106 (Table The Hector Mine earthquakes has been added as an 1 Hector Mine earthquake, as it nucleated on a splay fault and then ruptured 6-1) analog earthquake to Table 6-1 bilaterally. It also produced secondary rupture on a number of small faults. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 277 Table 6-The source faults in the 2010 El Mayor-Cucapah rupture were not Table 6-1 (near This statement. which was taken from Fletcher et al., 1 previously unidentified, as stated. These were all mapped by Barnard as Line 107) has been modified to stress that the existence of an part of his PhD thesis, and have been shown in a number of published 'integrated' fault system was not previously recognized. sources. All were named faults prior to the earthquake. What was not Additionally, text was added to state that the fault known is how all of these faults work together to accommodate oblique system consists of seven 'previously mapped' major strain. faults 278 Lines Please flesh out this line of reasoning out-Chapter 11 comment 104-105 The founding of the mission at SLO in 1772 together with the lack of reported earthquakes in mission documents provides a rationale for settina Tmin=242 vr. 279 Line "Missions were sensitive to strong ground motions" Chapter 11 comment 107 Please expand. 280 Line Please consider rephrasing -Chapter 11 comment 118-120 In summary, the lack of any damage reports in documents from the San Luis Obispo mission make it unlikely an earthquake of M6.5 or larger on DCPP Primary and Connected faults since 1772. 281 Line Figures 6-2 through 6-7. Consider presenting Table 7-2. Primary and Line 165 Revised as suggested. Table 6-5 provides the codes. 131 Connected Fault Section Codes and Descriptions here in Chapter 6 where References in Figures 6-2 to 6-7 updated. figures are first presented. 282 Line Please provide a more specific reference, i.e., number of section and Line 171 Revision made to cite the preliminary sensitivity results 137 figure(s). where the relevant sensitivity studies are described. presented at Workshop 1 283 Line Please note the typo: should be Figure 6-7 (rather than 6.7). Line 206 Corrected as suggested. 17') 284 Line Figure 6-7. Should a rupture source S4+S5+S6+S9+S10 be listed? Figure 6-7 No change. The list on Figure 6-7 is not intended to be 174 exhaustive but sufficiently detailed to explain the conceot. 285 Line This is one example of the usage of "SSC" where "SSC model" is Line 214 Text revised as suggested 180 recommended. Please ensure proper terminology throughout the text. 286 Line Please remove is" Chapter 11 comment 185 287 Lines "over the forward-modeling rupture model approach taken for the Diablo Lines 238-239 Text revised as suggested 204-205 Canyon SSC model" Model seems to be over-used in this sentence .. 288 Line Please remove "wide" Chapter 11 comment 212 289 Line Would the Hosgri fault be considered low slip rate and "within the noise?" Lines 247-250 Text revised as suggested. 215 Might want to temper this a bit by clarifying that the DCPP SSC model needs to deal with lesser faults and detailed characteristics of Hosgri fault. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 290 Line Consider adding a sentence noting that a forward modeling approach Lines 283-286 Text modified as suggested. 246 does not imply that there are no overall constraints in the SSC model on such things as cumulative slip rate and deformation rate. Rather, it just means that those constraints are not formally imposed within the framework of an inverse modeling approach. 291 Line Please change displacement to displacements. Chapter 11 comment 248 292 Line PDF is used to indicate a probability density function. Line 303 Text revised as suggested 264 293 Line Please consider whether the meaning would be clearer if the passage Line 327-328 Text revised as suggested 289 were rewritten as "such that, when the contributions from all rupture sources that include a particular fault are summed.". 294 Lines Are the slip rates uniform over the entire rupture source for the main fault Lines 332-333 Text revised to clarify. 294-296 (larger slip rate) and uniform over the entire rupture source for the secondary fault (smaller slip rate)? Please explain. 295 Line Please give an indication of what magnitudes would be considered Lines 360-361 Text revised to add magnitude range. 321 '"moderate to large." 296 Lines The last line of the paragraph is unclear as to its meaning. "'the number of Line 369 Text revised to change the word 'distinguish' to *assess' 330-331 events captured is very few or is difficult to distinguish." The first part makes sense -the number of events is very few. The second part is unclear -the number of events is difficult to distinguish." Distinguish from what? To count? To determine? 297 Lines Long sentence. please consider breaking it up. Lines 372-373 Text revised as suggested. 332-338 298 Line '"understood to accurately model" -please change to -understood to Lines 378-379 No revision. Split infinitive judged to more clearly convey 340 model accurately the central idea of the sentence. 299 Line '"but few are sufficiently large to preclude throughgoing fault rupture." Lines 383-384 Text revised as suggested. 343-345 Please consider adding to end of sentence -based on observations from other segmented strike-slip fault systems (Wesnousky, 2006). 300 Line Please define '"behavioral." Line 385 Text revised to clarify that "behavioral' refers to size and 346 timing 301 Line Figure 11-8 should be Figure 11-9. Chapter 11 comment 350 302 Line Please note the typo: "'MDF" should be "'MFD". Line 398 Typo corrected. 358 303 Line '"by maximum rupture source size" would read better as '"by the maximum Line 401 Text revised. 361 rupture ... 304 Line It is not clear how this sentence relates to the previous sentence. Does Lines 402-403 Text revised to better relate the sentences. 361-362 the maximum rupture source size relate to the characteristic earthquake rupture dimensions? COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 305 Line Please consider expressing this differently. Do you mean that the absence Lines 403-406 Yes; Text revised accordingly. 363-364 of that information is not a rationale for precluding characteristic-model behavior as part of the technically defensible range of models? 306 Line Please consider using a more descriptive term such as "exponential MDF" Line 408 Text modified as suggested. 367 here, since another exponential distribution (i.e., for recurrence times in a Poisson process) comes into the discussion elsewhere in the report. 307 Lines Is this saying that faults and portions of fault networks that have been Line 416 Word also added to sentence to clarify that, in many 370-375 modeled with characteristic earthquakes can ALSO be modeled with cases, either characteristic earthquake or truncated exponential distributions? Or that faults and portions of fault networks that exponential magnitude PDFs are arguably consistent are modeled individually with characteristic earthquakes can be with data. represented in aggregate with exponential distributions? 308 Line What is an historical limit? Is this the observed maximum for the fault? For Lines 421-423 Text revised to clarify. 379 any fault of the same slip type? Please clarify. 309 Line Consider replacing accidently with coincidentally. Chapter 11 comment 379 310 Line "equally durable scrutiny" Please consider replacing with -much scrutiny Line 435 Text revised as suggested 393 311 Line Please consider whether there is a published article or report that could Line 438 Text revised to cite Table 6-1 (several citations) in 396 be cited instead of the unpublished powerpoint presentation addition to Hardebeck presentation. 312 Line Please provide the justification for the sole selection of this relationship in Lines 453-463 Text revised to better explain rationale for the sole use 410-413 light of these issues. For example, why is this relationship preferred in of the Hanks and Bakun relationship. light of the "dimensions and style of faulting"? the tectonic setting? The "application of magnitudes in the PSHA"? 313 Line Please consider whether "end-member" is the optimal characterization of Line 464 Text revised to eliminate the 'end-member' terminology. 414 the set of proposed magnitude PDFs (i.e., what distribution are they end members of? Does that distribution have four endpoints?), or whether instead the set actually includes samples from throughout the distribution of proponent models. 314 Line Please delete the citation of an article that is "in preparation," or update Line 472 Text revised to cite Appendix G, which includes the draft 420 the citation to a published article. If that manuscript is unpublished but WAACY manuscript contains elements essential to this report, please include those elements in Appendix W AACY. 315 Line Please provide the rationale for the selection of these magnitude PDFs for Lines 479-480 The text has been revised to provide a cross reference 426 each rupture source type. Also, please provide the justification for the to Section t 0.2.3 for discussion of the rationale for branch weights cited here, or provide a reference to the report section selection and weighting of the various magnitude PDFs where that justification is given. for each rupture source type. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 316 Line 6.3.6 Time Dependency Model. Please consider moving this section up in Line 482 No change. 428 the chapter so that the sections mirror the order of the logic tree shown in It was noted in the initial discussion of the logic tree (see Figure 6-1: Time Dependency Model, FGM, Rupture model, Slip rate Lines 127-133) that the order of the logic tree is Allocation model, MOM organized to facilitate the implementation in the hazard code (i.e., global parameters that apply to all or a group of sources are listed first) followed by more specific assessments that pertain to individual sources. Terminology explained in the preceding sections is used in the discussion of the Time Dependency Model. Therefore the Tl Team feels that moving this section forward is not warranted. 317 Line Suggest clarifying that the theory relates to individual faults. PSHA began Line 491 Text revised as suggested 435-437 with the representation of seismic sources as zones that likely included multiple faults and. as a result. these behave more like a Poisson process. 318 Line This line refers to "coefficient of variation in the long-term mean rate." That Line 497 Text corrected to state, coefficient of variation in the 443 would be an epistemic uncertainty. However. please check whether that is recurrence model" the actual intent on this line, or whether the intended reference is to the coefficient of variation in the recurrence model (and which represents aleatory variability in recurrence time associated with a given long-term mean rate)? 319 Line What is meant by a "global parameter?" Lines 502-503 Text revised to include explanation. 448 320 Line "many tens of active faults". Please consider removing -tens of Line 506 Text revised as suggested. 452 321 Line Please replace "to" with " do" Chapter 11 comment 453 322 Line Please give a more specific reference to the sensitivity analyses that Lines 509-512 Text revised to clarify where results of sensitivity 456 support this statement about the hazard contribution from regional analyses were presented or described. sources (i.e .. by citing section number(s) and figure or table number(s) where the relevant analyses are presented). 323 Line "included as a fault sources". Either drop the "a" or change sources to Line 523 Text revised to drop the 'a' 466 singular. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 324 Line Why is a conservative characterization used? How do you know that it is Lines 538-540 Text revised; adjective describing the characterization 466-467 conservative? removed, and discussion of justification of rates used moved to Chapter 12. 325 Line Please indicate who is doing the judging in this and the next sentence. Lines 531-534 Text revised to specify that these are Tl Team 475 judgments. 326 Line Please explain what is meant by a point source" in this context. Text revised -set of point sources on regularly spaced 508 grid. Cross reference provided to Sections 13.3, 13.4 327 Figure Please replace loger with longer. Figure 6-1 Figure corrected 6-1 caption ATTACHMENT PPRP COMMENTS ON DCPP SSC DRAFT REPORT PPRP COMMENTS AND Tl TEAM RESPONSES,

GENERAL COMMENT

S AND CHAPTER 7 Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision General Comments 259 Overall, the chapters that comprise Installment #2 are well written and A technical edit has been performed provide the necessary documentation for several elements of the SSC model. As noted in Installment #1, the text would benefit from a comprehensive technical edit to ensure consistency in the usage of various terms, tense, third person, etc. Such an edit would also allow for more specific internal referencing to other sections of the report. Suggested edits are provided in these comments, but they are not exhaustive. 259 As noted in the PPRP comments for Installment #1, it is strongly We are committed to using the PG&E title block. Each recommended that figure captions be developed for every figure to assist figure has a title. Where appropriate. additional the reader in understanding the salient points of each figure. Title blocks explanatory notes have been added. and notes are helpful, but they often do not adequately convey the messages that the figure is intended to convey. 260 Throughout the text. the terms SSC" and SSC model" are used Usage of the acronym SSC has been standardized to interchangeably. Common usage would dictate that the elements of the strictly mean "seismic source characterization". SSC model should be indicated as such, and that the activity of characterizing seismic sources should be termed SSC. Editing the text for consistent usage is recommended. CHAPTER 7 -Fault Geometry Models 328 General Please make references to other parts of the report as specific as possible, Cross references have been checked and more specific i.e., by providing section number(s), and figure or table number(s) where subsections added where appropriate appropriate. Some instances where this is required are noted in specific comments. but please review the chapter for other instances and make appropriate changes. 329 Line 5-6 Common usage would call this a seismic source characterization model." Line 5 Text revised to add *model' as suggested. 330 Line 10 Figures 6-2 to 6-5 are maps showing Primary and connected fault sections Figures 6-5 and 6-6 are regional figures that show the not "Figures 6-5 to 6-6" as listed No change full extent of all of the Primary and Connected fault needed sections. 331 Line 18 Suggest making reference to the logic tree that shows these alternatives Text revised as suggested. and weights. Line 18 Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 332 Line 81 Please provide a more specific reference to the section(s) of Chapter 13 A discussion of seismogenic depth is not included in where the discussion cited here is presented. Chapter 13. More detail is provided here regarding the Lines 81-92 subset of the Hardebeck 2014 catalog used to calculate 090 and 095. and the resulting depths. 333 Line 83-84 Please provide a more specific reference to the section(s) of Chapter 14 Text revised to cite Workshop 1 sensitivity results that substantiate the claim made on these lines. Line 93 334 Line 96-97 You may also want to cite the deepening of seismicity after the 1999 lzmit Text revised to cite Ben-Zion and Lyakhovsky, 2006) earthquake. Seismicity deepened by-3 km, and recover over the following Line 109-112 modeling results that show transient deepening of 6 months (BenZion et al) aftershocks following a main shock. 335 Line 107-113 Please provide references to articles or the report section(s) that present Instead of referencing other parts of the report, the the observations and interpretation cited here. Lines 121-146 observations and interpretations that bear on the depth to the top of rupture are summarized here in this section. 336 Line118 Terminology is odd. Suggest changing "allowed to" to "assessed to." Text revised as suggested. Line 151 337 Line 131 Are these spatial patterns of epicenters and hypocenters? Does this Text revised to clarify include focal mechanisms and their associated geometries? 165-167 338 Plate 7-1 Plate 7-1. Why are the names of rivers and creeks highlighted by blue boxes? Please remove blue boxes around names of rivers and creeks. This appears to have been a problem with the pdf No change download. The final version does not show blue boxes needed around names of drainages. 339 Line 164 The wording on this line is ambiguous. Please rephrase this passage to Text revised to clarify. clarify whether it is the simplified representations" or the "actual faults" that Line 201-202 are shown in the cited figures. 340 Line 172 Please specify by whom it is considered to be insufficiently wide to be a Text revised to provide reference to Wesnousky (2008) barrier, and on what basis. Unclear what is meant by universal" in this and to clarify that the Tl Team assesses this complexity to context. It sounds like the Team made an assessment that the basin is not be useful for defining rupture sources and MFOs, but sufficiently wide to represent a barrier to ANY future ruptures? Lines 210-217 does not consider it sufficiently pronounced to prohibit 'oint rupture of the onshore and offshore Los Osos fault. 341 Line 174 "single fault connected fault source" The first "fault" could be deleted Agreed. Text revised to eliminate the first 'fault'. without losing anything. Line 218 342 Table 7-2 In reference to the Wilmar Avenue fault. it would be best to spell out Agreed. Table text revised accordingly. "Avenue" as it is a proper name. Table6-5 Please note that the table has been moved into Chapter 6. Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 343 Lines 188-Please consider rephrasing to the following Text revised for clarification 190 Two boundaries between fault sections that are not intersections between Lines 229-232 Primary or Connected fault sources are discussed below. 344 Line 217 Please specify by whom (e.g., the Tl Team) such geometries are assessed Text modified as follows: to be the only valid ones, and consider whether the intent of this line would Fault geometries for the Primary and Connected fault be better conveyed by the phrase "technically defensible" in place of sources were considered by the Tl Team to be "technically valid. permissible only if slip on the faults will produce this general pattern of vertical deformation. The Tl Team recognizes that other mapped faults (and possibly other Lines 256-263 blind faults) in the SLPB area may be capable of producing moderate to large earthquakes. However. the Tl Team judges that the slip rates of these other faults must be sufficiently low so as not to affect the observed uplift rate pattern. This category of other possible faults are considered as part of the areal source zones in the Diablo Canyon SSC model (Section 6.5 and Chapter 13). 345 Line 218 Please explain in the caption of Figure 7-4 the meaning of the additional The caption is expanded to define these interpretations of annotations such as "<0.05 m/kyr," that appear away from the dashed approximate uplift rates. contour curves (e.g., are these point constraints based on specific Figure 7-4 observations; or are they regional generalizations, and, if so, how wide an area do they apply to?). 346 Lines 242-Please provide a reference to the specific report section(s) where this Reference to Section 13.5.2 added. 246 assessment is justified. Lines 291-293 347 Line 245 "convincing evidence of unique fault geometry". Please consider changing Text revised as suggested. "of unique" to -for well defined Line 292 348 Line 292 Please define the rake ranges that distinguish the "reverse" sense of slip Text revised to clarify that the lateral component of slip from the "reverse oblique" sense of slip, since this distinction was not given varies among the three models, but is always secondary on Lines 259-264. Lines 338-342. to the reverse component. Because they use the same GMC models, the precise boundary between reverse and reverse oblique is not meaningful. 349 Line 307 A comma is required after "bathymetry data" for clarity Line 353 Text revised as suggested. 350 Line 308 Figure 7-5 is a good example of how figure captions would greatly help the Per general request, figures have been reviewed and reader interpret the panels of the figure. Figure 7-5 and explanatory text added where needed. others 351 Line 309 "DCPP that were compared to evaluate". Please consider replacing Text revised as suggested. "compared" with -examined Line 355 352 Line 338 "The HFZ is the best imaged, most continuous, and complex fault zone" Text revised to delete *complex* "complex" -scale dependent. thus level of complexity is dependent on imaging resolution -some of the faults in the Irish Hills could be equally or Line 384 more complex than the H FZ?? Please clarify. Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 353 Lines 341-"Locally, strands of the fault zone exhibit seafloor expression. either as Text revised to clarify that the fault-line erosional features 343 erosional fault-line scarps. or possibly also as tectonic scarps within young are generally observed in bedrock in contrast to scarps in sediment." Lines 387-390 young sediment inferred to represent youthful tectonic surface rupture. Please expand to explain differences between the two. 354 Line 343 Some explanation is needed either here andlor as a figure caption Caption added explaining what the ages of the MIS tracts and unconformities are in the Figure 7-6 figure. 355 Lines 351-Please explain how "aleatory uncertainty" can be captured by modeling Revised text to change 'uncertainty' to 'variability' and 352 "alternative near-surface traces." That is, doesn't the word "alternative" deleted the word 'alternative'. The point of this discussion imply epistemic uncertainty. and that the options for the trace location are is to describe aleatory variability. All three surface traces mutually exclusive (and isn't that the thrust of the discussion on Lines 390-have ruptured in the Quaternary and will likely rupture 404), which would preclude them acting in concert to produce aleatory Lines 399-400 again. variability? In contrast, the alternatives discussed in lines 390-404 (now 456-476) describe alternative (and mutually exclusive) interpretations of the down-dip geometry of the three surface traces. 356 Line 356 Please check whether there is a peer-reviewed report or article The 2012 citation is the Workshop 2 presentation and a documenting the study of Hardebeck cited on this line. and if there is, comma has been added to clarify that. The 2013 please cite that in preference to the unpublished Workshop 2 presentation. reference is a published paper. The Tl Team considers Line 405 citing both to be appropriate to indicate that the information was presented as part of the SSHAC Level 3 process and also confirmed by later publication. 357 Line 363 Please consider replacing "apparently" to -interpreted to be Line 416 Text revised as suggested. 358 Line 369 Consider replacing "and also" with "along with" Text revised to delete the phrase 'and also' and which 423 catalogs were used. 359 Line 376 The seismicity is projected onto a plane that is perpendicular to the strike of Text modified to clarify that seismicity is projected onto a the Hosgri fault. Also, it is very difficult to see the plus signs and dots on Figure 7-9 and plane perpendicular to the strike of the Hosgri fault. the figure. Can they be enlarged? Line 431 Plus signs are enlarged to distinguish them from dots. Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 360 Lines 379-Please explain the basis for the proposed associations of hypocenters to The text has been modified to provide further explanation 382 faults. and note any other analyses that were undertaken to try to resolve of how the seismicity was separated spatially, and provide the apparent ambiguity in those associations (as seen in Figure 7-9). For citation to the analyses considered in this separation. example, can the association of hypocenters to the Hosgri fault be improved by restricting the cross-sectional projection to events located The figure is also modified to incorporate more southeast of DCPP (avoiding interference from the northernmost part of the hypocenters into the category of uncertain association. Shoreline Fault and Estero Bay seismicity)? The Tl Team also considered the following analyses, but did not include them in this figure (or Figure 7-10) Lines 434-445 because they were judged to be less informative regarding the fault dip along the reach adjacent to the DCPP, or impractical to include in a static image: . Classification by Hardebeck (2013) of first motion polarities that are consistent with either Hosgri or Shoreline fault orientations, . Projection of narrower window within the San Luis Bay reach of the fault. . Visualization of hypocenters and focal mechanisms in 30 space. 361 Line 382 According to the legend. the plus symbols represent "uncertain Legend was updated to state 'intermediate location' association." Figure 7-9 consistent with the text. 362 Line 393 Please explain in what sense model H85 is the best fit to the seismicity. Text revised to note that the H85 provides a reasonable fit to the seismicity data and that it is most consistent with Lines 459-463 Hardebeck (2010. 2013) tomoDD focal mechanism OADC mean planar solution. 363 Line 398 Figure 7-11 indicates "systematic offset which could be better defined as Figure is updated as recommended. Discussion of possible systematic offset of hypocenter locations from the fault. Also, Figure 7-11 and "possible future data" is moved from the figure into the "possible future data" is cited in the figure text but is not discussed in the Line 468-470 text text. 364 Lines 400-"The H90 model fits the seismicity data, but is less consistent with fold The text is updated to cite the interpretation from 401 deformation that appears to indicate a flower structure on the reach Willingham et al. (2013) that the fault dips steeply to the adjacent to the DCPP. " Lines 474-477 east, and that the Hosgri fault is typically expressed as a There are many fault segments offshore, could the fold deformation and flower structure instead of parallel faults that do not flower structures be explained by constraining bends along a vertical strike-merge. slip fault -H90? 365 Line 452 "North" Please replace with -Northwest Line 534 Text revised as suggested. 366 Lines 464-"The concept of the outward-vergent (OV) model is that uplift of the SLPB The pattern of uplift inferred by the connection off the 466 is produced by transpressional right-reverse faulting along the northeastern Shoreline fault to the San Luis Bay fault is described in and southwestern block boundaries (Figure 7-13)." paragraph 5 of this section Please explainfdiscuss. The Shoreline is a vertical strike-slip fault. Reverse Lines 608-61 3 slip is occurring toward the southeast on BE, WA and OF fault segments. Such a configuration would predict uplift rates to increase toward the southeast-in contrast to the observations? Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 367 Line 469 Figure 7-14. Please discuss constraints on Los Osos dip from segment LE Additional explanation has been added to the introduction (80') to LO (60') of fault models, Section 7.4. to emphasize that very few definitive constraints are available on the dip of faults beneath the San Luis Range. To account for that, our approach is to interpret that uplift of the range is driven by Note added to fault slip. The SSC model includes a range of fault dips Figure 7-15. such that the entire uplifting range overlies at least one Lines 542-548 dipping fault plane. The difference in dip is explained by and 601-603 the difference in the width of the uplifting range. A second reason for the steep dip of LE is a speculative link to the Edna fault within the Irish Hills shown on Figure 7-17. Please note. Figure 7-14 has been renumbered to Figure 7-15 368 Lines 475-Junction with dextral-reverse Oceanic-West Huasna fault is not shown in Text revised to cite Plate 7-1, which does show 476 Figure 7-13 Line 576 intersection. 369 Line 476 Figure 7-13. Please discuss intersection of OF and SF -does the reverse No change to Reverse deformation west of the Shoreline fault is slip die toward the northwest? Why is there no reverse motion along text of Chapter interpreted as distributed deformation. This is discussed segment SF? 7 in Section 8.4. 370 Line 488 If the phrase *'seismic source zone" on this line means the same thing that Text revised to use consistent term -Local areal source "areal source zone" or Local Source Zone" means in Chapter 6, please zone use the appropriate one of those previously defined terms to provide a Line 589 consistent terminology throughout the report. If is means something else, olease define it. 371 Line 494 Please explain further the kinematics between shoreline fault and San Luis Uplift in the hanging wall of the San Luis Bay fault west of Bay fault in transect C-C' the Shoreline fault is interpreted to be caused by one of Lines 608-613 three factors: additional faults in the SWBZ, distributed deformation up-dip of the San Luis Bay fault, or a restraining bend in the Hosgri fault 372 Line 497 Figure 7-16. Why does ancestral Shoreline Fault have a dip? Please Figure replaced with an unrestored cross section, and the explain relationship with vertical Shoreline Fault. Figure 7-17 number is changed to 7 -17. 373 Line 497 Figure 7-16 legend states faults are solid where well located -Are Edna C Figure replaced with an unrestored cross section, and the and Los Osos faults well located down to -30,000 feet? Figure 7-17 number is changed to 7 -17. 374 Line 497 Figure 7-16. Please discuss constraints on dip between the range-The cross section shown in the figure (now 7-17) was bounding reverse faults and steeper strike-slip faults within the range for developed by PG&E. 2014, Chapter 7 based on the structural model shown in Figure 7-16 as well as uncertainties. Figure 7-17 interpretation of surficial geologic mapping, seismic-reflection data, and correlation to borings and wells. A note has been added to the figure stating this. 375 Line 508 Presumably, the sensitivity analyses only include a range of depths that are This paragraph has been moved to the section on depth considered to be credible. Other values could have an impact on the to top of rupture. hazard. Consider adding the phrase, " ... not a hazard-sensitive parameter Lines 142-t46 Instead of citing sensitivity analyses, the text is revised to given the range of technically-defensible depths." describe the the Tl Team judges that a simplification of using a single value of 1 km depth to represent a range of 0-2 km is justified. Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 376 Line 511-513 This sentence is confusing. Perhaps it could be broken into parts or set off Line 606 This sentence is not necessary in Chapter 7, so it was with commas. deleted. Uplift rates are covered in Section 8.2.2. 377 Line 515 "in" is repeated -please delete one. Lines 128-133 The pertinent text has been modified and moved. 378 Line 530 Please place a comma between "formations" and "which" for clarity. Text revised to change 'which' to that to indicate that the Line 620 following phrase is a key conclusion--not just an optional descriptor. No comma is needed after 'that'. 379 Lines 531-"Uplift of the continental shelf region west of the Shoreline fault as indicated The ages of the submerged marine terraces on the 532 by the presence of submerged marine terraces " continental shelf west of the Irish Hills are characterized Lines 608-610 in Section 8.4. What is germane to Chapter 7 is that the Please provide any age information (e.g., MIS3?) shelf in that region is uplifting in that region. The text is modified to reference the original work (PG&E. 20t 1, Appendix I) 380 Line 536 Please explain further how the kinematics in the Southwest Boundary Zone Uplift of the Irish Hills is driven by slip on the San Luis to the northwest of segments BR and BE engender the uplift rates and Bay fault. West of the Shoreline fault, uplift of the patterns shown in figure 7-4. continental shelf occurs as distributed deformation up-dip Lines 608-616 of the San Luis Bay fault. It is not clear whether this deformation is driven by a seismogenic fault (as in the SW model) or is more distributed, and therefore better modeled as an areal source zone (as in the NE and OV models). 381 Line 538 If the phrase "local seismic source zone" on this line means the same thing Text revised to be consistent with term 'Local areal that "areal source zone" or "Local Source Zone" means in Chapter 6, source zone* as described in Section 13.5. please use the appropriate one of those previously defined terms to Lines 615-616 provide a consistent terminology throughout the report. If is means something else. please define it. 382 Line 540-541 Please discuss the constraints on the Wilmar Avenue fault being rooted There are no good constraints on the dip of the Wilmar into the steeper Los Osos East (LE) fault. Avenue fault at depth. The OV FGM allows for a relatively No change to steeply dipping fault that could intersect the Edna fault at text depth. The Tl Team judges this to be a technically defensible interpretation given the overall width of the range. 383 Lines 542-How well are the fault intersections at depth known? Is it important to There is little available data to constrain the geometry of 543 GMC? Please provide any insights possible. faults within the Southwestern Boundary zone al depth. The alternative FGMs are used to capture what the Tl Team judges to be a technically defensible set of alternative dips and depths of intersection of faults beneath the San Luis Range. Text was added in the introductory text of Section 7.4 to note the lack of Lines 542-560 available data that could be constrain these fault intersections. In order to capture the range of technically defensible interpretations. the Primary faults that are the main drivers of uplift in each model (e.g., the San Luis Bay fault in the SW Model and the Los Osos fault in the NE model) have been modeled to extend to the full seismogenic depth. and are not considered to be truncated by otherfaults Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 384 Line 543 A comma between "fault" and "assuming" would make this line clearer. Line 626 Text revised as suggested. 385 Line 567 Please check the caption of Figure 7-17a. On the third line of the caption, Caption revised as suggested. Note that the figure has shouldn't sinestral transpression" be changed to sinistral transtension"? been moved to 7-18. Also please mention in the caption of Figure 7-17b the reference number Figure 7-18 for the transpressional reverse splay feature that is noted there. 386 Line 568 Figure 7-18. Southward dipping fault that intersects the Shoreline Fault at This figure has been deleted. depth is Dashed in Figure 7-18 and solid in Figure 7-16. Please make Figure deleted consistent. 387 Lines 622-Why does the SLB fault increase to 50' on cross section D -D'? Any As noted in the text added in introductory part of Section 623 constraints? 7.4, the dip of the fault inferred to accommodate uplift of Figure 7-23 the range may vary along strike depending on the width of the range. The uplifting range is narrower along cross Lines 542-548 section D-D* compared to cross sections B-B* and C-C'. A note was added to the figure to indicate this. 388 Lines 641-"The Los Osos East fault (LE) is characterized as an axial surface that dips We have chosen to honor our approach of modeling the 642 steeply to the southwest. " primary faults to a depth of 12 km more strictly than our approach of restricting the spatial limits of the fault planes In panel B-B', the Los Osos axial surface is not controlled by the change in to approximate the scale of the uplifting range. A note dip of the controlling detachment and intersection of the San Luis Bay fault has been added to Figure 7-22 explaining that we -please explain location and driver of the "zone of deformation" for the Los recognize that the geometry of the Los Osos fault Osos axial surface. Figure 7-22 intersection with the San Luis Bay fault in panel b (Section B-B') does not clearly fit the expected geometry of an axial surface with a change in dip of the underlying reverse fault. The geometry of the San Luis Bay fault has been simplified to better represent an end member model as a moderately dipping fault (45°) that extends to a seismogenic depth of 12 km. 389 Line 642 The terminology "fold hinge" is used in the figure, but "axial surface" is used Figures 7-21 The figures have been updated to read "axial surface" in the text. Please clarify. through 7-23 and 7-25 through 7-27 390 Line 657 This would read more clearly as "San Luis Bay, Wilmar Avenue and The most significant potential lateral ramp would be Oceano faults). There is also an extra comma at the end, but inside the between the SLBF and the faults underlying the Edna parentheses. Lines 741-743 sub-block (the WAF and OF). The text has been revised to clarify and to correct typo as suggested. 391 Line 668 Should this be fold" axis? Lines 710-712 Text revised to read axial surface or backthrust 392 Line 682 Should "OV" model be SW model? Lines 763-764 Yes. Text revised to correct. 393 Line 684-689 This sentence is too long and could be improved for clarity. Lines 765-772 Text revised to break the sentence up for clarity. Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 394 Lines 729-Please move lines 773 -776 right after 734 so the reader knows why the Text revised as suggested. 734 dips of the faults are different for the Edna block in A-A* in Figure 7-22 and Lines 819-822 Figure 7-26. 395 Line 747 Granularity? Do you mean resolution? Regional constraints? Please Text revised to use the term 'sufficient coverage' clarify. Line 835 396 Line 752 "The dip of the Los Osos fault is shown as 500 throughout the entire The cross sections are corrected to show the Los Osos seismogenic crust beneath the Irish Hills." Figures 7-26 fault consistently with a 50 degree dip. II is shown as 60" in profile B-B' in Figure 7-26. and 7-27 397 Line 780-781 Sierra Pampeanas is the Spanish spelling, Pampean Ranges is the English Text revised to use consistent terminology. spelling -you have mixed the two. Please choose one. Line 866 398 Line 797-802 This statement is not germane to DCPP and is an incorrect interpretation. Agreed. Text from lines 807-812, and the note about They based this on a leveling line at the south end of the range where shortening rate in the following sentence were deleted. topography is actually low, and then apply the 1977 observed deformation Line 882 to the highest part of the range. This results in a shortening rate that is an order of magnitude higher than actually exists. It would be preferable to delete this sentence as it adds nothing. 399 Line 824 This 1st sentence would read better if a couple words were added: Agreed. We made the recommended changes. " ... subsequently been reactivated in the contemporary tectonic setting as _g Line 903 transpressional system." 400 Lines 834-Uplift patterns in the SW portion of the Irish Hills (Figure 7-4) northwest of Text revised to discuss how th is region of uplift is handled 837 segments BR and BE (Figure 7-13) are difficult to explain in the OV model Lines 915-924 in the OV Model. -please expand the section to clarify the uplift boundary. 401 Figure 7-20 The massif names are lh Bogd and Baga Bogd (Big Bogd and Little Bogd). Figure modified as requested. This spelling is different than in the text (see line 584). which uses the correct spelling. Please correct this figure to be consistent with the text. Figure 7-20 COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT PPRP COMMENTS AND Tl TEAM RESPONSES, CHAPTER 8 Location in Comment Location in PPRP Comment Text for Summary of Revisions to Report Number Text1 Comment Revision Chapter 8 Section 8.2, Please reference the section (and table or figure number Lines 18-19 Reference to appropriate Section has page 94. 1st if appropriate) where this sensitivity analysis is been added. 168 paragraph, documented. 2nd to last sentence: Section 8.2, Please replace "initial" with "completed" or just delete. Line 18 The word' initial' has been deleted. page 94. 1st 169 paragraph, 2 lines up from bottom Section 8.2, Please explain why the assertion here that the No change No change to text. page 94, 3rd environment is one of transpression doesn't contradict the paragraph of approach introduced in Section 5.5 of considering both The transpressional setting of the section, 1st transpressional and NE-SW crustal shortening models of Hosgri fault, particularly along its reach sentence: active deformation. adjacent to the DCPP, is largely inferred from the orientation of the fault within the present tectonic stress regime and evidence for a small component of 170 vertical slip indicated by positive flower structures and up-to-the east vertical offsets of the ELP unconformity. The two 'end member' models described in Section 5.4 are primarily addressing more regional conditions within the Los Osos Domain to the east of the Hosgri fault 1 Unless otherwise indicated, paragraphs identified are for the section, rather than on the page cited. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location in PPRP Comment Text for Summary of Revisions to Report Number Text1 Comment Revision Section 8.2, Please indicate whether the transpressional strain Lines 36-39 The following text has been added: Page 94, referred to here is dextral or sinistral, and how these paragraph 3 might change as the fault systems trend to the east and Within this strain regime, faults that line 3/4 become more easterly in strike. strike northwest are favorably oriented 171 to accommodate dextral slip, and more easterly-striking faults (approximately perpendicular to the direction of maximum compression) are favorably oriented to accommodate reverse slip (Fiqure 5-12). Section 8.2, Note that this is a sentence fragment. Please rewrite. Line 41 Corrected typo; sentence fragment page 94, 3rd should have been included with 172 paragraph of preceding sentence. section, last 2 lines on page: Section 8.2, If this is the first occurrence of this fault name, please Line 65 Definition of acronym added. page 95, define its acronym at this point. 173 2nd to last paragraph of section, Line 4 Section 8.2, : Please note the typo: CDF means "cumulative Line 69 Corrected page 95, distribution function" {not "continuous"). 174 last paragraph of section. line 2 Section This presentation of new models would benefit from a Note: Chapter has been reorganized to 8.2.1, Page more complete discussion of the older models. Lines 160-make Geologic Slip Rate CDFs Section 95 188 8.2.1 and Quaternary Uplift Rate 175 (Section 8.2.2). The text has been modified to summarize key observations and COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location in PPRP Comment Text for Summary of Revisions to Report Number Text1 Comment Revision conclusions of older models. Section "Are judged" by whom? Please specify. If this is to be Line 215 Text has been modified to clarify that 8.2.1.1, presented as a judgment by the Tl Team on the basis of this is a judgment of the Tl T earn page 96, 3rd the comment made about hydro-isostatic adjustment, Lines 225-176 bulleted please say so, otherwise cite reference. 229 Note that the discussion of uplift rate item: PDFs for the Irish Hills block (and associated figures 8-5 and 8-6} have been moved forward from previous location in Section 8.5) Section The bimodal ages from Point Loma are not on the lowest Line 242; The text has been clarified to note that 8.2.1.2, terrace, they are from the 2nd emergent terrace, the Lines 247-the bimodal ages are from the Nestor Page 97, Nestor terrace. Please correct. Also, the last line states 252 terrace. A statement also has been 177 Paragraph 1 that unlike San Nicholas Island, Point Loma and Cayucos added to note that remnants of a slightly do not have fragments of the older -120 ka terrace at higher terrace are present, but are slightly higher elevation Actually, there is a slightly correlated to MIS 7 by Kern and higher terrace in the San Diego sequence but it is inferred Rockwell (1992) to be the MIS 7 terrace (Kern and Rockwell, 1992). Section It is difficult to follow the logic in this paragraph -is the Lines 253-Text has been added to clarify age 8.2.1.2, preferred interpretation that the 13 m terrace at Cayucos 293 preference (MIS Se} for the 13 +/- 1 m 178 page 97, 4th formed during MIS Se? Please clarify. terrace. paragraph Section Figure is incorrectly labeled "San Nicolas Island. Figure 8-9 Figure title changed to 179 8.2.1.2 Figure 8.2. 1-Marine Terrace Observations, Ellysly 5 Creek Section Mentions a flight of 4-5 possible marine terraces, but lists Lines 295-The text has been modified as follows 8.2.1.3. the elevations of only 4 terraces. Please clarify. 297 Page 98, Recent work identified remnants of 180 paragraph 1. surfaces underlain by marine deposits line 1 within the Edna Valley (PG&E, 2013b). Terrace remnants are mapped at elevations of 40 m, 55 m. 70 m. and 80 m. 181 Section Refers to a personal communication from John Caskey. Lines 299-The discussion has been modified to COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location in PPRP Comment Text for Summary of Revisions to Report Number Text1 Comment Revision 8.2.1.3, The discussion appears to be quite speculative and need 316 reference only the observations in the Page 98, additional support. PG&E (2013b) report and those paragraph 2, presented more clearly in this report. It line2 is acknowledged that the inference regarding correlation to the late Pliocene warm interval (-3.3 -3.0 Ma, paleosea level of-22 m (+/- 10 m) is speculative Section "strongly developed soil" -is this documented? What are Lines 368-A description of the soil profile 8.2.1.3, its characteristics? Please provide a reference 385 described by Chea and Caskey and 182 Page 98, clay profile based on laboratory paragraph 3, Attachment analyses has been added to support the line 11 E-4 of Tl Team assessment regarding the age Appendix E of the Memorial Park terrace. Section "pedimentation" is the wrong word here. Pediments form Line 343 Agreed. Text modified accordingly to 8.2.1.3, in regions of vertical tectonic stability over long periods of replace 'pedimentation' with 'lateral Page 99, time. In this case, a flat surface can only result from fluvial erosion' 183 paragraph 4, marine planation of fluvial planation, neither of which line2 would be considered pedimentation in this context. Please consider replacing "pedimentation" with "lateral fluvial erosion". Section There seems to be a lot of conjecture in this paragraph, Lines 317-The discussion of the geomorphology, 8.2.1.3, most of which is not well documented except as a 392 stratigraphy, and soil profile Page 99, personal communication. Please provide better development has been expanded to paragraph 4. documentation. explain and defend the statements in this better document and support the 184 paragraph, and include references. For instance, "it is estimated age of the Memorial Park unlikely that the Memorial Park terrace surface is younger surface. than about 400 ka" -please provide better documentation and discussion on this key age parameter, as it implies very low rates of uplift of Los Osos Valley. Section Should this be equation 5.1. There are other "equation Line 76 Text modified to label this equation as 185 8.2.2, Page (1 )"usages in the report (c.f. page 133) 8-1 following the overall numbering 99, equation system for equations in this report--( 1) numbered sequentially by Chapter. 186 Section Is there a parentheses missing here? No change No--parentheses appear to be COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location in PPRP Comment Text for Summary of Revisions to Report Number Text1 Comment Revision 8.2.2, Page appropriate. 99, paragraph 3, line4 Section The abbreviation CDF means "cumulative distribution Line 102 Text has been corrected to ref er to 8.2.2, page function" (not "continuous" distribution function, nor 'cumulative distribution function' 187 100, 3rd cumulative "density" function). If you intend to say paragraph, "cumulative distribution function" (as appears to be the Line 4: case from the context), please reword appropriately. Section Please be clear about how the CDFs may be combined Lines 105-The text has been modified to clarify 8.2.2, page (for example, perhaps you mean by forming a weighted 110 that PDFs are combined different ways 100, 3rd sum with weights summing to 1.0?), or reference the for different types of uncertainty. For 188 paragraph, report section where that explanation is given. PDFs describing uncertainty in parts of Line 8 the total offsets, offsets are summed using Monte Carlo methods. For PDFs describing epistemic uncertainty in a value, the PDFs are weiQhted. Section Please replace "correct" with robust or has high Line 130 The term 'correct' was replaced by 8.2.2, p. confidence. 'robust' as suggested. 189 100, 5th paragraph, 5 lines down Section If there is not a single correct (but unknown) slip rate for a Lines 135-The text has been modified to clarify 8.2.2, p. given section of a fault, then there must be some 136 that slip rate CDFs represent epistemic 100, 5th variability in slip rate along that section. Typically, the slip Lines 146-uncertainty in the actual slip rate of the paragraph, rate CDF would be assumed to represent epistemic 149 fault. They do not incorporate aleatory last uncertainty in what the "true" slip rate actually is for a variability in slip rate over time or 190 sentence particular section of fault of interest. If the distribution also distance. includes aleatory variability. as implied in this sentence, there should be a discussion of how that variability is estimated and distinguished from the epistemic uncertainty. Also. if that variability is dependent on the location along a fault, then that should be indicated and discussed as well. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location in PPRP Comment Text for Summary of Revisions to Report Number Text1 Comment Revision Section 8.3, The discussion would be easier to follow if the location of Figure 8-13 The location of the Piedras Blancas page 101, the Piedras Blancas anticlinorium were shown on Figure anticlinorium has been added to Figure 191 paragraph 4, 8.3.1 (at a minimum, some appropriate figure locating that 8.3.1 Line 4: feature should be referenced). Section 8.3, Are the seismic reflection data used to constrain slip rates No change The sentence states that 'Interpretation 192 Page 101. or interpret them? of offset channels ... constrains .. .'. The Paragraph term constrains is appropriate --4, line 7 therefore, no change needed. Section Please expand the discussion on the preferred offset. as Figure 8-14 Figure and text modified to provide 8.3.1, page the figure only shows Oso terrace offset as a minimum at Lines 497-more explanation of the preferred offset 193 102, Figure 150 m. Figure 8.3-3 mentions piercing points across the 509 (and constraints on range of values) as 8.3-2 HFZ as the basis for preferred offset; consider labeling on described in the text. Fiqure 8.3-2. Section The discussion of Figure 8.3-3 would be easier to follow if Figures 8-16 We agree. The text and figure are 8.3.1 page the panels were labeled (i.e., a,b,c) and cited specifically Lines 497-updated to reflect this change. 103, 2nd (e.g., Figure 8.3-3(a)). This comment applies to many of 509 194 paragraph the composite figures in the chapter. (and following paragraphs): Section Traverse Range?? Do you mean Transverse Ranges, or Line 213 Text modified to read ... in the western 8.3.1, Page WTR?? Transverse Ranges ... 195 103, 3rd bulleted paragraph Section "require reversal in uplift for the lower terraces" Please Figure 8-15 We have added a new figure to illustrate 8.3.1 , page provide more clarification why the Muhs et al.. 2012 this better. and revised the text 196 103. 3rd studies on San Nicolas Island would require that. Line 496 accordingly paragraph, 3rd bullet 2 lines up 197 Section The CDF curve does not plot exceedance probability, but Lines Text corrected. 8.3.1, page rather its complement. Please correct this, and check the 519-523, COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location in PPRP Comment Text for Summary of Revisions to Report Number Text1 Comment Revision 104, 2nd use of the word "exceedance throughout the chapter, as it 605-607, paragraph seems to be used repeatedly in this same erroneous 1434-1436, on page, sense. 1533-1534, Lines 2 and 1732-1734, 3: 1839-1840, 2133-2135 Section "hence broader, are not inconsistent with ... " This is a Lines 528-Text modified to remove double 8.3.1, Page double negative. Is it possible to make this more straight 531 negative. 104, forward to "are consistent with"? 198 paragraph 7 (last of section), line 2,3 Section "Cumulative density function" is incorrect. You may mean Lines 590-Text corrected 8.3.2, page either "probability density function" or "cumulative 594 199 105, 3rd distribution function" (probably the latter, since that is paragraph, what appears in the last panel of the figure under Line 3: discussion, FiQure 8.3-5). Please clarify. Section Please consider rewording to avoid ambiguity, since the Lines 606-Text corrected 8.3.2, page tabulated probabilities are not exceedance probabilities, 608 200 105, last but their complements. paragraph on page, Line 2: Section Figure 5-9 does not seem to show the Piedras Blancas Figure 8-13 Call out to Figure 5-9 has been changed 8.3.3, page anticlinorium. as the text implies. If it does not, please to be Figure 8.3-1 (now Figure 8-13). A 201 106, 1st remedy this inconsistency. label has been added to Figure 8-13 to paragraph of show location of the PB anticlinorium section. line 2: Section Please elaborate on the implications of "the western Lines 657-Text has been added to better explain 8.3.3, Page branch of the Hosgri is not the current locus of 661 the constraints of possible slip that may 202 107, deformation." Does this imply that this fault strand does be added to the Hosgri fault source to paragraph 4. not increase the Hosgri rate to the south? Please provide the south based on the observation of last line an explanation of the significance of this observation. no offset of datums inferred to be 135-COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location in PPRP Comment Text for Summary of Revisions to Report Number Text1 Comment Revision 125 ka. The constraints on slip rate emphasize that the 0.2 mm/yr modeled for Piedras Blancas is conservative. Section Please rephrase this sentence as it is not clear. Lines 771-This sentence and preceding sentence 8.3.4.2, 775 were modified to clarify statements. 203 Page 109, Paragraph 4, line 7 Section "at least five glacial terminations" Are you referring to Line 826 Text modified to add the word 'major' 8.3.4.3, major (100 ka) glacial phases, as appears to be the case? before glacial terminations. 204 Page 110, If so, please indicate that these are major glacial Paragraph terminations. 4, line4 Section "Paleo slope breaks associated with unconformities H10 Lines 656-Additional discussion has been added. 8.3.4.3, and H30 occur more than 1 km west of the paleo slope 601 page 111, break associated with unconformity H40 (PG&E, 2014, Lines 871-7th Chapter 3 Figure 6-3, and Figure 8.3-6) suggesting that 890 paragraph, 5 the lowstands preceding H10 and H30 reached 205 lines down significantly greater depths than the lowstand preceding H40. This relationship strongly supports the preferred unconformity age model and contradicts the relationships that would be predicted by the alternative model (Figure 8.3-7)." This argument is important and would benefit from additional discussion. Section Could the relatively high amplitudes from the channel Bottom of A footnote has been added speculating 8.3.5, page thalweg be gas? Please consider whether gas might give page 8-32 of that the higher amplitudes may result 113, 5th rise to some of the observed changes in acoustic 8-74 below from gas trapped within channel 206 paragraph, 7 reflectivity. Line 1004 sediment. We wanted to avoid lines down discussing this in the body of the text because it distracts from the main message, which is that channels are difficult to distinguish on these data. 207 Section "Due to this uncertainty, the Tl team assessment of offset Lines The full range of Channel F offset 8.3.6, page across the fault does not rely directly on channel Fe." How 1078-1081 considered by the Tl Team exceeds all COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location in PPRP Comment Text for Summary of Revisions to Report Number Text1 Comment Revision 115, 2nd does this affect overall slip rate estimates? What were the of the uncertainty estimates reported in paragraph, estimates from the PG&E 2014 CH3 report? PG&E, 2014 Ch. 3, but the mean last estimates are the same. Text has been sentence added to this section to clarify that point. Three alternative correlations for Channel Complex F and associated offsets were presented in PG&E 2014 Ch. 3. Correlations and offsets were reported as follows: Preferred, entire HFZ: Fe3/Fw3 min. 550 Max. 700 Pref. 600-650 Alternate, entire HFZ: Fe1/Fw3 min. 450 max. 600 pref. 500-550 Western Strand: Fc1/Fw3: min. 376 max. 490 pref. 435 Eastern Strand: Fe3/Fc1: min. 150 max. 250 pref. 200 PG&E (2014, Ch. 3) calculated slip rates for the preferred and alternate correlation across the entire HFZ. No attempt was made to sum the offsets across individual strands and use those to estimate a slip rate. Section Fe1 and FW1 are not shown in Figure 8.3-16 Figure 8-29 Channel thalwegs for Fw1 and Fw2 208 8.3.6 page were added to the figure, and a callout 116, Figure was added to the boundary of Fe1. 8.3-16 Section As stated later, the slip rates to the north are expected to Lines The single GDF describes epistemic 209 8.3.7, Page be higher than at DCPP, whereas the southern slip rate is 1106-1118 uncertainty in the part of the HFZ 116, expected to be lower due to pulling slip I deformation off directly offshore of the DCPP. The Tl Paragraph 1 onto the Los Osos, San Luis Bay and other faults. Please team considers it likely that slip rate COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location in PPRP Comment Text for Summary of Revisions to Report Number Text1 Comment Revision discuss the implications of combining all of the rates into a increases to the north, and has single CDF. incorporated that judgment into the SSC model through the use of additional rupture sources on the HFZ to the north of the DCPP. A discussion of this issue has been added to the text. Section This statement would appear to imply that the slip rate Lines Yes the slip rate assessments at each 8.3.7, p. estimates at each site are epistemic assessments of the 1136-1140 site represent the epistemic uncertainty 116, 1st true rate at each site, but the weights assigned to each of in the SR at that site. The weights paragraph, the sites represents the degree of belief that any given assigned to the alternative reflect the Tl last site is an indicator of the rate along the fault near the plant Team judgment as to the likelihood that 210 sentence site. This is all epistemic uncertainty. However, as stated the individual site assessments are below in the last sentence of this paragraph, the representative of the rate along the fault integrated distribution might also have an aleatory near the DCPP (based on quality of component in it, implying that there is true variability in the data and proximity to the site) (i.e., slip rate opposite the plant. Please explain if this is the epistemic uncertainty in the SR for the case. fault closest to the DCPP). The text is modified to clarify this point. Section Does this imply that there is aleatory variability in the -see above-No: see response to 209 and 210. 8.3.7, p. integrated distribution across all sites? because any correction 211 for tectonic uplift/subsid ence rate to these terrs Section Please note that the first column heading should be Line 1255 Corrected as suggested. 212 8.3.8.3. "Zeng" (not "Zheng"). page 120, Table 8-1, Section The CDF table may have a typo, as the first two entries Figure 8-39 This is not a typo. These numbers are 213 8.4.1, Figure give different cumulative probability, but at the same slip the same when rounded to two decimal 8.4-6: rate. places. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location in PPRP Comment Text for Summary of Revisions to Report Number Text1 Comment Revision Section Refers to the "lateral slip is a good approximation of the No change Text not changed. 8.4.1, Page net slip rate." But that hasn't been presented yet. It may 123, be better to state that it "will be" a good ... The slip rate doesn't change whether 214 paragraph 3, we have presented it or not. The ratios line3 of horizontal to vertical offset demonstrate that the lateral slip rate (whatever it is) is a good approximation of net slio rate. Section It is important to determine if the terrace riser is older or Figure 8-37 The profile in Figure 8-37 is the best 8.4.1, page younger that H40 -Are there any seismic data, that would one to use for evaluate this relationship. 123, 4th allow the Tl team to trace H40 from the west? The Tl Team has explored the available paragraph, data and has concluded that the H40 215 10 lines unconformity cannot be traced down continuously into the San Luis Obispo Bay area with high confidence, but it is likely that the unconformity continues. The plausible extension of H40 was added to the figure. Section The last 10 or so lines of this paragraph are somewhat Lines 1390-The text in question was clarified. 8.4.1, Page confusing. Could this be made clearer I simpler? 1395 216 123, paragraph 4, Figure 8.4-5 Lower part of figure has an arrow to the right with 630 ka, Line 1418 The age quoted in the text was 217 which refers to the possible upper end of the age range of corrected. The slip rate is calculated the terrace sequence. In the text on page 124, 1st using a maximum age of 630. paragraph, 625 ka is stated. Please be consistent. Section Please reference Figure 8.4-2 providing the map showing Line 1442 Added as suggested 8.4.2, Page location of channel I, which the subsequent discussion in 218 124, 1st this paragraph relies upon. paragraph of section. 1st line: 219 Section Please reference Figure 8.4-2. which provides the map Line 1541 Added as suggested 8.4.3 Page showing location of channel A that the subsequent COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location in PPRP Comment Text for Summary of Revisions to Report Number Text1 Comment Revision 127, 1st discussion in this paragraph relies upon. paragraph of section, 1st line: Section Please explain what observation or analysis led the Tl Lines New text was added to explain why the 8.4.3, Page Team's interpretation to differ from the previous PG&E 1556-1558 Tl team did not accept the PG&E 127, 3rd interpretation. 1576-1594 interpretation, and chose to re-interpret paragraph, the data. 220 second to last sentence and last sentence: Section The assumption here is that lithology and stream power Lines The paragraph has been modified to 8.4.3, Page are similar over time, which is likely the case as these 1656-1663 clarify the assumptions 128, 6th three "streams" likely originate from the same drainage 221 paragraph, source. This should be made clear that they all have the lines 9-10 same source, and that the drainage area has not likely evolved much to its present state over the expected age range of these three channels. Otherwise, the rest of the an::iuments in this section fail. Section Should the reference be to Figure 8.4-13? Figure 8-38 No. The cited figure (8.4-5) shows the 8.4.3, Page range of possible ages relative to the 222 129, 2nd sea level curve paragraph on page, Line 7: Section Please summarize what specific observations and/or Lines The section was re-organized to better 8.4.3, Page analysis led the Tl Team's age model to differ from the 1600-1647 describe the previous PG&E age model 129, 2nd previous PG&E model. 1727-1730 and describe why the Tl Team's age 223 paragraph model is different. on page, last sentence: 224 Section Might want to rephrase the sentence below so it is clear Line 1702 We have rephrased the sentence to COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location in PPRP Comment Text for Summary of Revisions to Report Number Text1 Comment Revision 8.4.3, page that Channel A is older than Channel C -"The MIS 6 age eliminate the erroneous statement that 129, 9th alternative is preferred and assigned a weight of [O. 7] channel C was older than Channel A. paragraph, 3 based on the observation that Channel A is crosscut by lines down Channels Band C, and therefore must be older than them (Figure 8.4-11) and the greater depth of incision of Channel C, suggesting it is likely a full sea-level cycle older than Channel A (as described above and illustrated in Fioure 8.4-12)." Section The San Luis Bay "kinematic indicators of strain No change The observation of reverse to reverse-8.4.4.2, (slickenlines) are compatible with reverse or reverse left oblique slickenlines on a trace of the Page 131, oblique slip" This is the first time that the possibility of left San Luis Bay fault is one of the reasons 2nd bulleted oblique slip has been raised. Is this congruent with the that the OV model is not weighted point OV model, which implies right oblique slip on the parallel higher than it is. This observation is Los Osos fault? essentially a strike against the OV model, but it does not completely invalidate the model. These slickenlines are observed on just one 225 trace within a zone of surface faults that we interpret to be secondary to the primary fault at depth. It is possible that this particular trace last deformed in a reverse or reverse-left oblique sense, but the fault zone as a whole generally accommodates dextral oblique reverse motion. No change to text Section "Based on this assessment. the uplift rate of the Irish Hills Lines The chapter has been reorganized to 8.4.4.2. Slip ranges from 0.15 mm/yr to 0.35 mm/yr, but most likely is 1814-1820 provide the assessment of Irish Hills rate of between approximately 0.18 and 0.23 mm/yr." Please uplift rate in the approach, Section 226 SWBZ, page expand on why is it most likely? 8.2.2. A reference to that section has 132, 1st been added as explanation of why uplift paragraph 7 rates between 0.18 and 0.23 mm/yr are lines down most likely. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location in PPRP Comment Text for Summary of Revisions to Report Number Text1 Comment Revision Section The input parameters for the resolved slip calculation are Figure 8-48 This figure has been divided into two 8.4.4.2, in Figure 8.4-15 (not 8.4-16). separate figures (8-48 and 8-49) to Page 133, clarify the slip rate calculations. The 227 3nd figure references have been updated. paragraph on page, Line 1: 8.4.4.2, This discussion seems to indicate that the vertical rate on Lines An introduction and conclusion to this Page 134 the Shoreline fault is possibly on par with the horizontal 1782-1796 section have been added to explain that and 135 rate (up to 0.11 mm/yr vertical, with a best estimate of this simple kinematic model is used to 0.07 mm/yr horizontal). Is this consistent with other Lines justify an increase in slip rate on the interpretations that the Shoreline fault is mostly strike-1953-1955 northern Shoreline fault relative to the slip? (focal mechanisms, offset channels and shoreline 1966-1995 southern Shoreline fault, a difference features, vertical dip, etc.). Please clarify the support for that the Tl Team interprets to be likely. this interpretation. The Tl team acknowledges that vertical separation predicted by the model is not 228 consistent with the other observations pointed out in this comment, and therefore does not include that component of slip into the net slip rate assessment for the Shoreline fault. Given the small differences in slip rate, the Tl team judges that use of this simple model is appropriate in lieu of a more complicated model that better fits all observations. Section "The second age model is called the post-LGM age Lines Text has been added that elaborates on 8.4.4.2. model. This model, which is assigned a weight of [0.4), 1941-1944 processes that may have led to Constraints accounting for the possibility that the wave cut platforms development of wave-cut platforms on Vertical mapped by PG&E (2011) do not represent long-lived during the last transgression. 229 Separation stillstands. and may instead be erosional surfaces Rate developed during the last transgression." Please provide Lines We have also modified the justification Offshore of additional justification for this weight, given the Tl's 1924-1935 for our weight on the MIS 3-5 model by Irish Hills, assessment that the MIS 3 -5 age is likely to be "correct". stating it is "more likely to be correct page 135, than the alternative model." COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location in PPRP Comment Text for Summary of Revisions to Report Number Text1 Comment Revision 3rd paragraph, 15 lines down Section 8.5, Please consider referencing the section of the report Line 2049 Cross reference to Section 7.4 added page 136, where the concept of "fault models" was defined and the as suggested. 230 2nd NE, SW and OV cases introduced. paragraph of section, 2nd to last line: Section Hanging wall uplift-rate PDFs (Figure 8.5-2) and footwall Figure 8-55 The CDFs shown in Figure 8-55 were 8.5.1, page uplift-rate PDFs are all bounded density functions. Please calculated using the Monte Carlo 138, explain how bounded PDFs (as opposed to discrete method described in Section 8.2.1. The 231 probability mass distributions) can combine to give the steps in the CDF result from the bin size discontinuous CDF's shown in Figure 8.5-6 (hint: they of Monte Carlo sampling. A note has can't), or clarify how the CDF's in Figure 8.5-6 were been added to this and other figures to actually calculated, or correct the plot (and subsequent describe this. ones) if it is erroneous. Section "The maximum value considered is -0.21 mm/yr based Lines Text is modified to indicate that the 8.5.1, page on the assumption that the magnitude of hanging wall 2092-2097 maximum subsidence rate is set at 0.2 138, 4th uplift (preferred uplift rate of the Irish Hills) is the upper mm/yr based on Tl Team judgment that paragraph, limit on footwall subsidence as predicted by various the subsidence rate of this small crustal last structural models (e.g .. King et al., 1988; Stein et al .. depression does not exceed the uplift sentence 1988)." rate of the Irish Hills, a much larger crustal block. 232 Please provide clarification here as hanging wall uplift Reference to the Stein and King models causes rock to displace air-large density contrast: has been removed. whereas foot wall subsidence causes crustal rocks to displaces mantle -small density contrast -it is the density contrast and associated buoyancy that controls magnitude of subsidence. Thus subsidence is larger than associated uplift for both extensional and compressional environments. 233 Section Please state the rationale that the selected fault dips Line 2121 Cross reference to appropriate sections 8.5.1, page adequately represent the full technically defensible range, of Chapter 7 have been added. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location in PPRP Comment Text for Summary of Revisions to Report Number Text1 Comment Revision 138, last or reference the section of the report that does so. paragraph, 1st sentence: Section Please state the technical justification for the range of Lines Additional text and a cross reference to 8.5.1, page rakes employed. 2123-2131 Section 7.2.4 was added to explain 138, last range of rakes assigned to different 234 paragraph of styles of faulting. section, 2nd to last sentence: Section The terminology used in Figure 8.5-7 is ambiguous. What Figure 8-56 The figure has been modified to show 8.5.1, page does "deviation from vertical mean there? Unless the the rake angles. 138, last fault has a dip of 90 degrees, then there is no vertical 235 paragraph of reference direction within the fault plane. If you mean the section, 2nd complement of the rake angle, please say so (or to last "deviation from the up-dip direction"). sentence: Section Here, the Memorial Park terrace is potentially correlated Line 2111 Revised text in Section 8.2.2.3 8.5.1, Page to the -400 m (should read -400 ka); ... Earlier, 400 ka discussing the estimated age of the 138, was suggested as a minimum age for this terrace. Which Memorial Park surface shows that paragraph 6, is it, and what is the likelihood that it is younger, as this correlation of the surface to MIS 11 236 line 14 discussion was not very clear earlier in the report. (-400 ka) is a reasonable interpretation, not a maximum age. A cross reference has been added to Section 8.2.2.3. Section In discussing Figures 8.5-8 through 8.5-10, please explain Figures 8-57 The apparent steps in the vertical rate 8.5.2 page how the net slip rate can have a continuous CDF to 8-59 CDFs result from the sampling bins 237 138, 1st (implying a bounded PDF), while vertical rate has a used in the Monte Carlo calculations. A paragraph of discontinuous CDF (implying a discrete probability mass note has been added to the figures to section. Line distribution). state this. 2-3 238 Section The expression "the center of the range" is used here Lines The description has been updated to 8.5.3, Page without definition. It seems to correspond to the 21st to 2155-2162 provide the range and weighted mean COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location in PPRP Comment Text for Summary of Revisions to Report Number Text1 Comment Revision 139, 1st 79th percentile values in Figure 8.5.11, but similar 2257-2264 values for each of the three fault paragraph of expressions (e.g .. "center of the PDF") have been used models. section: previously in the report for intervals defined differently. Please make the intended meaning clearer here. Section 8.6, Note the extra ". )" at end of paragraph. Line 2215 The parenthesis has been removed. 239 Page 1, 1st paragraph, last line: Section Please reference the section of the report where the Line 2214 A reference to Section 7.4 has been 8.6.1, page alternative age models were evaluated and the weights added to the end of the previous section 240 1, 1st cited here were justified. (when the three models are first paragraph of mentioned). section, last line: Section If this statement refers back to an assessment from an Lines References to Section 8.2.2.1 and the 8.6.1 page earlier part of the report, that section should be 2224-2225 pertinent figures have been added. 241 1, 2nd referenced. In not, please provide a more complete paragraph of statement of the technical justification here. section, 2nd sentence: Section "Deviation from vertical is not an acceptable terminology, Lines The figures and descriptions have been 8.6.2, page because it is ambiguous (there is no vertical reference 2252-2253 modified to show the rake angles. 242 1, 1st direction in the fault plane unless dip is 90 degrees). paragraph of Please use a conventional and unambiguous terminology. Figures 8-56 section. 1st and others line. Section Please explain why the GDF for the vertical rate appears Figures 8-62, A note has been added to the figures 8.6.2, page to be discontinuous (stepped) in Figures 8.6-2. 3. and 4 8-63, and 8-explaining that the apparent steps in the 1, 1st (which would imply a discrete probability mass function). 64 GDF result from the bin size for 243 paragraph of or correct the figure. sampling in the Monte Carlo section. last calculations. line on page: 244 Section Please state the technical justification that the selected Line 2250 A reference to Section 7-4 has been 8.6.2, page fault dips adequately represent the full technically added. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location in PPRP Comment Text for Summary of Revisions to Report Number Text1 Comment Revision 2, last defensible range, or reference the section of the report paragraph of that does so. section, Line 2: Section The sentence refers to a PDF for fault rake, but the range Line 2253 The angles have been changed to 8.6.2, page of angles cited seems to apply to the complement of the describe uncertainty in the rake. 2, last rake. Please check and make a correction if needed. 245 paragraph of section, last sentence: Section Please clarify the meaning of the "plus or minus 1 degree" Line 2253 The text has been revised to clarify that 8.6.2, page in the description of the distribution. a uniform distribution is used. 246 2, last paragraph of section, last sentence: Section Please state the technical justification that this rake angle Lines A paragraph has been added at the end 8.6.2, page distribution adequately represents the full technically 2231-2242 of 8.6.1 describing the justification for 247 2, last defensible range, or reference the section of the report the rake angles considered. paragraph of that does so. section, last sentence: Section Please indicate left or right oblique. If right oblique, Lines Text has been added to explain that the 8.6.3, Page please explain why it is different from earlier statements 2231-2242 rake is interpreted to be dominantly 248 2, 3rd bullet that kinematic data suggest left oblique to reverse. If right reverse with uncertainty in both oblique, please explain (somewhere) how the SLB and directions. Los Osos faults, which are nearly parallel. can have the opposite sense of oblique slip, if that is the case. Lines Added discussion of UCERF3 rates. 2291-2296 Section 8. 7, "San LuisPismo" is written "San Luis-Pismo" in the list of Line 2298 Text has been through technical edit to 249 page 1, 1st abbreviations and acronyms, and in most occurrences correct to San Luis-Pismo. paragraph, elsewhere in the report. line 1: COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location in PPRP Comment Text for Summary of Revisions to Report Number Text1 Comment Revision Section Please indicate whether the oblique slip is left or right Line 2322 "right-" has been added before oblique. 8.7.1, Page oblique. 250 1, Paragraph 2, last line Section Please provide a reference to a report, or to a section Lines Sensitivity analyses presented in 8.7.1, page (and figure) of this report, that documents the sensitivity 2315-2316 Chapter 6 of the Shoreline fault report 1, 2nd analysis cited here. (PG&E, 2011) and in Workshop 1 251 paragraph, (documented in Appendix D of this Line 1: report) both support the statement made here. Reference to that documentation has been added. Section Please check whether "Wilmar Avenue fault" should be Line 2375 The fault name has been corrected 8.7.2, page "Oceana fault" instead. 252 2, last paragraph on page, Line 1: Figures in The discussions of total slip and age PDFs and the Figures 8-6, These references have been added to Chapter 8, associated slip-rate CDFs in the chapter would be easier 16, 18, 28, the figures 253 general to follow if the multi-panel figures such as Figure 8.3-3, 32, 39, 42, comment: 8.3-5, and many others. had panel labels (i.e., "a", "b", "c", 46, 49, 52, etc), and if the individual panels were referred to by letter 55, 56, 61 in the text (e.g .. "Figure 8.3-3a"). 254 Figure 8.5-5: Is the location of the D-D' cross-section shown in Figure Figure 8-53 The cross section location has been 8.5-5? added Figure 8.5-7: "Deviation from vertical" is ambiguous: please correct Figure 8-56 "Deviation from vertical" has been 255 this. removed, and the figures are updated to show rake of the faults. Figures 8.5-"Deviation from vertical distribution" (footnote to the table Figures 8-57, "Deviation from vertical" has been 256 8, 9 & 10: on right of figure) is ambiguous; please replace with 8-58, 8-59 removed, and the figures are updated to standard, unambiguous terminology. show rake of the faults. 257 Figures 8.6-"Deviation from vertical distribution" (footnote to the table Figures 8-62, "Deviation from vertical" has been 2, 3. &4: on right of figure) is ambiguous; please replace with 8-63, and 8-removed, and the figures are updated to COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location in PPRP Comment Text for Summary of Revisions to Report Number Text1 Comment Revision standard, unambiguous terminology. 64 show rake of the faults. Figures 8.6-In the footnote to the table on right of each of these Figures 8-62, The note has been updated to more 258 2, 3, &4: figures, the meaning of "1-19 degrees plus or minus 1 8-63, and 8-clearly describe that uncertainty in rake degree" is unclear. 64 is represented by a uniform distribution from 70 to 110 degrees. COMMENT-RESPONSE LOG DIABLO CANYON SSC STUDY DRAFT REPORT PPRP COMMENTS AND Tl TEAM RESPONSES, CHAPTER 9 Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision CHAPTER 9-Rupture Models 547 Line 5 "Historical ruptures have involved .. . Some historical ruptures? Many Line 5 Text revised to clarify historical ruptures? Please clarify. 548 Line 6 "single fault zone" is referenced to the 1992 Landers earthquake, Line 6 Text revised to clarify which actually involved 5 separate faults. Please clarify or correct. 549 Line 8 Using a colon after "styles of faulting" is change in style from earlier in Line 8 Text revised for consistency the paragraph where the earthquake was in parentheses. Please make consistent for clarity of readinci. 550 Line 13 "define fault rupture lengths" Do you mean to define potential rupture Lines 13-20 Text revised to clarify lengths? Define the potential for future rupture lengths? Define future potential rupture lenciths? Please clarify. 551 Lines Please state more explicitly the technical rationale for the choice to Lines 27-42 Text revised to better explain the concepts behind the 28-30 treat the rupture sources as aleatory variability. How is it different from development of the Rupture Model with respect to aleatory a recurrence curve that expresses the aleatory variability in the variability and epistemic uncertainty magnitudes (and rupture dimensions) of possible earthquakes that occur on a fault source? Additional explanation is needed to understand the concept, the technical basis, and the implications to the SSC model. Also, there is an implication that epistemic uncertainties have not been included. It is recommended that the manner in which epistemic uncertainties were captured be identified here in juxtaposition with the statement that epistemic uncertainties are not included in the modeling of rupture sources. 552 Line 37 Plate 9-1. Please explain why the surface projection of dipping rupture Plate 9-1 No Revision. North of the DCPP, all Hosgri FGMs have a source changes along strike for 75* dip, but appears more constant for vertical trace. This is for simplicity with linked and complex 85" ruptures involving northern Hosgri and SLPB faults. It is not important to hazard as the difference in fault width is small, and the difference in source-site distance, etc. is likewise small 553 Lines There is epistemic uncertainty regarding the slip rates, but how is slip Lines 65-68 Text revised to clarify 45-46 rate itself treated as epistemic uncertainty. Please clarify your mean in a. 554 Line 49 "A demonstration" or "demonstrations" ?? Line 71 Text corrected. 555 Lines The fault names should all be followed by fault for clarity (i.e., Hosgri Lines 79-80 Text revised as suggested. 57-58 fault, Shoreline fault, etc.) 556 Line Please clarify that the historical examples from Chapter 7 were Line 85 Text revised to clarify. 62-63 possible analogues for each FGM. taken from other regions. COMMENT-RESPONSE LOG DIABLO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision 557 Lines Both here and Line 231, the declaration is made, without much Lines 81-91 Text revised to clarify. 65-68 technical basis, that the suite of rupture sources "captures the range of viable ruptures." How is this consistent with the SSHAC imperative to capture the CBR of the TOI? What is the basis for judging that the range is captured, especially since the approach of identifying specific rupture sources is different from the classic approach of defining recurrence curves for each fault source? It is noted that the range is considered adequate to capture the sources that contribute significantly to the hazard. Were there hazard sensitivity analyses conducted to support this assertion? 558 Line 81 The descriptions of the respective rupture source types in Figure 9-1 Figure 9-1 Figure modified. differ significantly from the definitions given in Table 9-2. If the figure and table are intended to convey different types of information, please make that clear in the text and figure caption. In any event, please make sure that it is clear which characteristics are the defining characteristics of the rupture source types, and which just represent typical examples. 559 Line 84 Explain what defines the length of a characteristic rupture as being Lines 105-111 Text revised to clarify the terminology and to avoid confusion <100 km. There are many worldwide examples of longer with regard to criteria !Of defining a characteristic-type rupture. characteristic' ruptures. Are you saying the Hosgri fault only produces characteristic ruptures that are less than 100 km in length (-M7.2). Clearly later in the report, this is not the case. There needs to be some explanation as to why you broke out characteristic behavior to be limited to relatively short rupture seqments. 560 Line 96 Please replace comma with a semicolon after GMC model, Line 121 Text revised as suggested 561 Line Please consider some alternative way to describe "splay" rupture Lines 130-132 Text revised as suggested to better define splay type of 105 source type, because "overlapping source planes" is ambiguous (i.e .. rupture. in what sense do the planes overlap?). Branching of the rupture surface seems to be an important element. 562 Line "Based on empirical observations" implies that there is a direct linkage Lines 143-149 Text revised as suggested 117 between the observations and the topologies, and little judgment required by the Tl Team. Isn't it more accurate to say that the topologies are developed by the Tl Team based on a consideration of historical earthquake ruptures that may be analogous to the ruptures in the reaion? 563 Lines Isn't down-dip hyphenated? No change No hyphen. downdip" is designated as one word in the PG&E 119 Style Guide word list. The technical editor has checked and numerous times on Google Ngram Viewer for its spelling in the 130 literature. The results consistently show that the one-word spelling is more common than the hyphenated spelling. The Schlumberger Oilfield Glossary also lists it as one. COMMENT-RESPONSE LOG DIABLO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision 564 Line The description of slip rates for complex and splay rupture sources is Lines 150-152 Text revised to clarify 123-ambiguous. For example, if the intended meaning is that the primary 125 part of a rupture source (complex or splay) has a uniform slip rate and the secondary part of the same rupture source has a different uniform slip rate, please make that clear. 565 Line This sentence seems to be missing a verb. Please correct for clarity. Line 160 Text revised to add missing verb 132 566 Line The only stated exception to the obtuse angle requirement is the Because the intersection angle between the Los Osos and San 138-Hosgri-Shoreline splay. Please explain how the Los Osos-San Luis Luis Bay is at depth, and there ii is acute. 141 Bay splay is consistent with this taxonomy (i.e., why isn't ii also considered an exception to the obtuse anqle requirement?). 567 Line The three types of features" does not seem to include major steps or Lines 175-179 Text explains that this was considered for one of the rules to 143 bends, although the majority of historical ruptures had endpoints at develop the rupture source. but was not needed as an explicit steps or bends. Was this intended? rule for the DCPP rupture sources. 568 Lines Please include references to the corresponding figures from Chapter 6 No change required. 156-on which the segment locations are shown. Plates 9-1 and 9-2. which are referenced in the first sentence 162 of this statement, define each seqment location and name 569 Line This sentence is confusingly written, because the subject is ruptures Lines 197-199 Text revised as suggested 164-[across branch points)" and the direct object is also "ruptures." Please 166 rewrite to make it clear that it is the branch points themselves that may be the sites of rupture arrest more frequently than are generic fault ooints. 570 Lines This seems to imply that more ruptures will include both the Hosgri Lines 208-210 Statement added to clarify that the boundary is used to assess 170-and San Andreas faults, versus the Hosgri-San Gregorio fault where it Mmax lengths, which should remind reader that these rupture 174 meets the San Andreas fault. Is this what you intended to mean? source total lengths are for the largest Mmax earthquakes. Please clarify. 571 Lines In defending this conclusion. perhaps the point should be made that Lines 266 to 276 Text revised as suggested. 231-the CBR is supported by the careful review of analogies and the fact 234 that the salient elements of the rupture topologies are supported by observations that they have occurred elsewhere during actual earthquakes. Are there hazard sensitivity cases that show this? 572 Line Please consider replacing "in which" to where Lines 306-308 Text revised to clean up sentence structure. 266 573 Line Please consider replacing "Although this result was considered by the Lines 315-317 Text revised as suggested 275 Tl Team in developing the rupture sources," with -Although the Tl Team considered this result when developing the rupture sources," 574 Line Please spell out RO and LH on figure Figure9-2 Figure revised as requested to include explanations of 281 abbreviations Figure 9-2 575 Line Approximately 6 km in which direction? Line 324-325 The 6 km refers to the length of surface rupture on the 284 Kawafune fault as shown on Figure 9-2 COMMENT-RESPONSE LOG DIABLO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision 576 Line Kawafune? Is this a fault name? Please specify "fault" Line 325 Text revised to add the word 'fault' 285 577 Line If both were reverse displacements, it would be clearer to say Line 326 Text revised as suggested 286 "opposite sense of vertical slip" 578 Line General dip angle? Do you mean average dip angle? The general Lines 345-346 Text revised to clarify. 305 direction of dip? Please clarify. 579 Line Stretches? Do you mean extends? Line 349 Text revised to use the term extends instead of stretches. 309 580 Line Is M6.5 a large earthquake? Most seismologists would consider this a Line 350 Text revised as suggested 310 moderate event. Rather than using "large", you could say "surface-ruoturina earthauakes 581 Lines No fault section has been defined to indicate what "that section of the Line 356 Text revised to clarify. 315, fault" refers to. Please clarify. 318 582 Line You should also reference Sieh, 1996. as this was one of his Line 365 Reference added 325 examples to argue for the slip patch model. 583 Line Subsurface rupture? Line 378 Text revised to correct to 'subsurface' 336 584 Line "bordered the flank Do you mean bordered" orflanked". This Line 381-385 Text revised to clarify. 341 statement is unclear, as written. 585 Lines Are you referring to rupture of the Brawley fault? Please clarify this Line 384-385 Yes. Text clarified. 341-342 586 Line Please consider deleting "instruments". Line 387 Text revised as suggested. 344 587 Line Please change "Displacement on" to displacement in Line 402 Text revised as suggested 359 588 Line "several major and many right-lateral faults"? Consider deleting "and Line 408 Text revised to add *minor' as an adjective 365 many" or qualify as "many minor" 589 Line Geodetic strain needs more clarity of meaning. Wasn't the geodetic Line 410 Text revised to add the modifier 'historical' before strain as 367 strain fairly localized? described in the source reference (Sieh et al. t993). The description is of the ECSZ as a whole, not the Landers rupture. 590 Line Does a 30 degree change in strike count as sub-parallel?? Line 412 Text revised to delete the term 'subparallel' 369 591 Lines This is somewhat misleading and semantic. The Landers/Kickapoo Lines 415-421 Text revised 372-fault is essentially co-I inear with the southern section of the Johnson 373 Valley fault (which wasn't recognized prior to the 1992 earthquake). Basically, the Landers and southern JVF are the same fault. The rupture stalled for 7 seconds at the intersection with the Homestead Valley fault, and then re-nucleated on the HVF to continue the rupture. Two maior sub-events. See fiaure below. Comment Location Number in Text 592 593 594 595 596 597 598 Lines 375-376 Lines 378-380 Line 385 Line 386 Line 395, Figure 9-6 Lines 407-408 Lines 412-413 COMMENT-RESPONSE LOG DIABLO CANYON SSC STUDY DRAFT REPORT PPRP Comment Location in Textfor Comment Revision The step from the Emerson fault to the Camp Rock fault is not Line 420 contractional -it is also a releasing step. Please provide references for estimates of stress drop and the Lines 425-433 relationship between stress drop and recurrence intervals (e.g., Rockwell et al., 2000). Please add year (2012) to Madden and Pollard. Line 438 Please change "to better resolve" to to resolve better. Line 439 Please explain "culled measurements" Figure 9-6 Angle of the prestress? Or just the fact that the main Denali was Lines 490-495 stressed whereas the eastern Denali was not. probably due to a recent failure. Please clarifv What is meant here? Most faults were previously mapped and named Lines 497-509 (Barnard. 1965). Are you just saying that it wasn't known that they would rupture together? In the same sense, the 1992 Landers earthquake identified a previously unknown fault system, and the southern Johnson Valley fault was not known in the literature. Please clarifv. Summary of Revisions to Report Text revised to correct statement. Additional text added as requested. Text revised as suggested. Text revised as suggested. No change. Reader is directed to Wesnousky (2008) for explanation. This is not germane to the SSC model Additional text added to discuss this concept. Text revised to clarify. COMMENT-RESPONSE LOG DIABLO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision "Previously unidentified fault system" is an accurate quote from the study of Fletcher et al. However, many of the individual faults involved in that rupture were known and mapped beforehand. Please consider adding a few words to clarify this point. 599 Line Check this. There was a foreshock on a north-striking normal fault. but Line 505 Fletcher et al. (2014) state that the rupture intiated on a north 417 the mainshock initiated on a northwest-striking fault-the Laguna trending fault (see opening sentence of conclusion); their Salada fault. Please consider, given the uncertainties, whether a less Figure 3 shoes a smaller M 5.7 event at the north end of the categorical statement would be more appropriate. rupture as well. The text is revised to note the central location of the fault on the rupture near a north-trendinQ fault. 600 Lines Please clarify reversal in slip. This could mean normal to reverse. Lines 513-514 The sentence indicated that the reversal was with respect to 424-Right-lateral to left-lateral. What you mean is that the dip direction the sense of vertical slip. The text has been revised to further 425 switched from SW in the southern half to NE in the northern half of the clarify. rupture? 601 Line Series of several?? Please clarify. Lines 518-520 Text revised to delete 'series of' 429 602 Line Is HB vertical? If so, the surface projection of dipping rupture source Plate 9-1 The Hosgri fault from sections HB to the north is modeled as a 447, (pink) stops south of HB. If correct, please state on plate 9-1 or in text. vertical fault. Additional text will be added to Chapter 7 (after Plate 9-the original line 404) and as a note on Plate 9-t to clarify this. 1 603 Line The phrase "uncertainty in the distance" could be understood to Line 545 Text revised to make it clear that it is aleatory variability that is 456 suggest that it represents epistemic uncertainty. The way the model is being discussed in this sentence. employed, that does not appear to be the case, but rather that all of the Hosgri rupture sources occur on any one branch of the logic tree, so that the rupture sources collectively define aleatory variability. If the latter is the correct interpretation, please consider adding some clarification that it is actually aleatory variability in future rupture distances that is modeled bv the device described here. 604 Lines Please add -with different dips -to the end of the sentence below Line 548 Text revised as suggested. 457-459 "These sources are identical in length, extending from the south end of the Hosgri fault to the MT J, but they occupy different strands of the fault zone directly west of the DCPP." 605 Line Please consider adding subscript to H-01 (75), H-02 (85), and H03 (90) Table 9-3 No change to table. Text is clear above that all three 471, in the table geometries use the same rupture model. Adding subscripts Table would add unnecessary clutter 9-3 606 Line How about just a section of the Hosgri fault as a characteristic rupture? Line 560, Table 9-Text added to Section 9.2. t.1 to clarify that characteristic 471 Is this scenario accounted for in one of the models? Please clarify how 3 earthquakes are included in the Magnitude Distribution Models Table shorter Hosgri fault ruptures are accommodated by this model as this (MD Ms) for the longer linked and splay ruptures. 9-3 seems to be the most likely scenario and it is not clearly presented. 607 Lines Models H-01, H-02, and H-03 are essentially the same except for the Scenario is not in the model. Scenario would not meaningfully 476-site to source distance. In reality, they may all fail together as a broad add to variability. uncertainty in ground motions 486 zone -is that scenario in the model?? COMMENT-RESPONSE LOG DIABLO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision 608 Line Consider changing analogy to analogous. Line 588 Text revised as suggested. 499 609 Line "recent 20 dynamic .. . Define "recent. 2003 is 12 years old. Please Line 591 Text revised to delete the word 'recent' 502 clarify. 610 Lines Please consider shortening sentence or breaking into parts. Line 591-597. Text revised to split into two sentences 502-507 611 Line Please explain why SH is secondary and BE+ BR are primary in OV-Line 627, Table 9-This was a typo. SH is primary. Table fixed to show SH as 538, 03 -this makes sense for the SW model but not for the OV -is it 4 primary. Table driven by slip rate? 9-4 612 Line Consider rephrasing -"The south end the rupture source is the south Lines 635-637 Text revised as suggested. 546 end of the Shoreline fault source-the intersection with the Casmalia fault." to The sooth end of the Shoreline fault source at the intersection with the Casmalia fault is the south end of the rupture source. 613 Line Figure 7-2 should be Figure 7-4? Line 675 Agree. Text revised as suggested. 582 614 Line This would read more clearly if "an" was placed before "oppositely" Line 679 Text revised as suggested 596 (shoo Id have been 586) 615 Line Please explain why some ruptures continue to the MT J and some end The linked rupture sources. which can accept floating 605 at the north end of the San Gregorio fault. earthquakes, extent to MT J and have epistemic uncertainty in Mmax. The complex and splay sources, or just the more northern ones that don't contribute to hazard, stop at the north end of the San Gregorio fault for simplicity. The complex and splay ones cannot have floating earthquakes, and this is such a low probability event that we don't include it. 616 Lines It is stated here that SW-01 through SW-03 "acknowledge uncertainty" Lines 721-726 Text revised to remove ambiguity regarding all rupture sources 630, in whetherthe set of faults rupture together, but that SW-04 through representing aleatory variability. 634 SW-07 "describe variability" in ruptures on another set of faults. This contrast in language could leave the impression that one treatment is epistemic and the other aleatory, whereas it appears that the SSC model is set up to treat both as aleatory variability. If that is the correct interpretation, please consider using more consistent language to highlights that fact. If that is not the correct interpretation, please clarifv. 617 Line Recent work has shown a strong strike-slip component on the Little No change. This component was from the Miocene per 661 Pine fault (Cannon. 2012) Onderdonk, pers. comm .. and Cannon's thesis. Recent slip apoears to be reverse COMMENT-RESPONSE LOG DIABLO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision 618 Line Figure 7-2 should be Figure 7-4? Line 767 Text revised to correct Figure number. 673 and 684 619 Line This is word-for-word the same as in the previous section -needs an Line 782 Text revised to insert *an 689 "an" before "oppositely for clarity. 620 Line No comma is needed after California Line 783, 784 No change. Response from Technical Editor: 690 Re the comma after "California': that is absolutely correct. The rule is that you use commas in pairs when the phrase or sentence continues beyond the element being set off. The same is true for the year when you give a full date. (Ex.: September 10, 2001, was the fast day of its kind in the United States.) 621 Line This would read more clearly with "that" between SWBZ" and "could" Line 790 Text revised as suggested. 697 622 Line You need a period at the end of the sentence Line 796 Text revised as suggested. 703 623 Lines Commas are not needed after "California" or "Japan". Lines 825, 826 No change. Response from Technical Editor 729. Re the comma after "California': that is absolutely correct. The 730 rule is that you use commas in pairs when the phrase or sentence continues beyond the element being set off. The same is true for the year when you give a full date. (Ex.: September 10, 2001. was the last day of its kind in the United Stales.) 624 Line This would read more clearly if you replaced "Like" with "As with" Line 830 Text revised as suggested 734 625 Table Please spell out Avenue for Wilmar Avenue fault, as it is a formal Line 846; Table 9-Text revised as suggested. 9-6 name. 6 626 Lines This is another case where the switch in language from "uncertainty" to Lines 836-839 Text revised to clarify. 740-variability" is a potential point of confusion. Please consider using 749 consistent language to keep it clear that the range of rupture sources Table (within a given Rupture Model) represents aleatory variability. 9-61Plate 9-2. 627 Line Please explain -LB and LE dip south -why is surface projection of No change As shown on Figure 7-26a, the main fault in this rupture is the 750 rupture to the north? Wilmar Avenue fault, which extends at a shallower dip beneath the Edna Valley. The LB and LE form a secondary backthrust (splay} that branches from the underlying ramp at the point of dip chanae. COMMENT-RESPONSE LOG DIABLO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision 628 Line If rupture source NE-11 models "the possibility that the Morro Bay Lines 896-904 Text revised to clarify and correct misrepresentations of what 806 basin does not represent a step-over," doesn't this represent at least might be interpreted to be epistemic uncertainty rather than some conflation of epistemic and aleatory elements in the SSC model? aleatory variablity. That is, "represents a stepover and does not represent a step-over are, on the face of it, mutually exclusive alternatives. so represent epistemic uncertainty. Yet they appear to occur concurrently in the NE loaic tree branch. Please exolain whv this is not a contradiction. 629 Line Please explain surface projection change along segments NL and FN Lines 661-664, Text included to explain the geometry of the rupture model 818 in NE-07 (Splay) 791-794, 920-923 explicitly for OV-04, SW-07, and NE-07 630 Line This results in faults that do not intersect at depth unless the Hosgri No Change. The fault sections. as drawn, do intersect. The 834 ruptures south of the intersection. proximity of the mapped traces is such that joint rupture would not be orecluded. 631 Line Please remind the reader of what the first piece was. Line 951 Text revised to clarify. 851 632 Line It would help the reader to remind them that the slip rate allocation will Line 953 Text revised as suggested. 852 ultimately provide information related to earthquake recurrence rates. 633 Line If this feature (greater slip rate) is merely the definition of "primary," Lines 982-983 Text revised to avoid the implication that the amount of slip is 880 please make that clear (otherwise it is ambiguous, because there is the criteria used to define the *primary' part of the rupture the alternative that "primary" has been defined on some other criteria source. and then this sentence becomes a rule about assigning relative slip rates). 634 Line The slip rate should be greater by an amount proportional to the ratio Line 984 Text revised to correct mistake 881-momentfarea of each part (not the moment alone). Please correct this 882 statement (although it is cleared up in the subseguent eauationsl. 635 Line Units should be specified here (e.g., the seismic moment given by Eq. Line 992 Text revised to specify units. 891 9-4 is in dyne-cm) 636 Line This sentence is confusing. The first clause appears to be just a partial Lines 1077-1080 Text revised to clarify the steps in the approach 974-restatement of a more precise statement in the second clause. Please 977 rewrite to improve clarity. 637 Line Please state the criteria that were used to conclude that the fits were Line 1109 Text added to state they were evaluated based on visual 1006 satisfactory. inspection. 638 Line As 89% of the rate is on the H-01, H-02, and H-03 models, does this Line 1125 Earthquakes on the rupture sources are modeled based on 1022 imply that these ruptures extend all of the way to the MT J? This is not magnitude PDFs presented in Chapter 10. The allocated slip Table entirely clear, as presented. rate is for the entire rupture source, including all the way to 9-8 MT J, but it is used up mostly with floating earthquakes that are distant from the DCPP. 639 Line There are eight Hosgri rupture sources. If the reference on this line to Lines 1149-1150 Text revised to clarify that the five rupture sources described 1046 "the five Hosgri rupture sources" is meant to refer only to those that involve the section of the fault adjacent to the DCPP rupture the Hosgri Fault Source, please indicate that, and in any event olease clarify the statement. 640 Line It is 54% not 65% as stated in Explanation column Line 1153 (Table Text has been added to clarify that H-04 and H-05 are also on 1048 9-9) the Central strand and contribute (0.06 +0.5 = 0.11 ). Thus the Table 054 + 0.11=0.65. COMMENT-RESPONSE LOG DIABLO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision 9-9. H-01 (Centra I strandl 641 Lines If the location is aleatory, then the relative frequency of each location Line 1164-1175 The following paragraph outlines the geologic and geomorphic 1055-must be defined by the Tl Team. Please inform the reader how the data used to inform the values selected by the Tl T earn to 1058 relative frequencies (fractions) were assessed by the Tl Team. What represent the aleatory variability in the location of future types of data were considered? What was the role of different types of ruptures. Aleatory variability is expressed as the slip rate data (e.g., geomorphic expression, analogs, indications of vertical allocated to each rupture source (i.e .* the percentage, or component of slip)? The reader needs to know that this is an expert fraction of the entire slip rate). assessment process (i.e., the numbers don't just fall out of the calculations), but the expert judgments are informed by a variety of data constraints. 642 Line Please consider replacing "not as continuous a trace" with -a Line 1166 Text revised as suggested. 1062 discontinuous trace 643 Lines What if one or more strands were more strongly strike-slip (ie., Line 1168-1169 No change to text. Review has a good point. but the 1064-different horizlvert ratios)? How does this compare with the offset assumption is stated that we use the vertical separation as a 1067 channel data from LESS Lines 1215-1216? proxy. The range in slip rate values for each source (low, middle, high) covers the possibility that our proxy is misleading. 644 Line "The plant" is elsewhere called "the DCPP." Please consider keeping Line 1181 Text revised to replace 'planf with 'DCPP' 1077 the terminology consistent. 645 Line Please consider adding two letter segment after "western reach of the Lines 1181-1183 Text revised to include two-letter codes to clarify the segments 1077 Hosgri fault source' (HB) so it not confused with HW involved in the rupture. 646 Line If "relative merits of this configuration compared to others" means Lines 1192-1194 Text revised to better explain 1087 compared to other options for filling in the limited Shoreline Fault slip budget. please add that clarification. Otherwise, add some explanation of what the phrase means in this context. 647 Line It would be useful to explain the difference between the 54% allocation Table 9-9 and Text added to Table 9-9 (see response to Comment 640 and to 1090 and the approximately 65% estimated based on vertical separation. lines 1196-1199. last sentence of Section 9.2.3.1 to explain why the 54% and Please explain whv these values are not in conflict with each other. 65% values are not in conflict with each other.. 648 Line The Hosgri slip rate CDF seems to have been presented in Section Line 1209 and Minor edits made to check Section and figure references. 1097 8.3.7 (not 8.3.3). Please check and correct if necessary. Also please Figure 9-10 Discrete" removed from the figures. The black lines are indeed explain why the Hosgri slip rate CDF shown as a solid black curve in discrete distributions, but the large sample size (10,000) and Figure 9-9 is called a "discrete Hosgri CDF' when it appears in the the GDF makes them look continuous. In text, discrete only figure to be a continuous function, and seems to be presented as a used for the logic tree combinations. continuous CDF in Section 8.3.7 (e.g., Figure 8.3-20). In what sense is it "discrete" (that term would seem more appropriate for the logic-tree CDF. and the term is used in that sense on Line 1101)? 649 Line Please replace "it is a satisfactory" with "it provided a satisfactory." Line 1207 Text revised as suggested. 1099 COMMENT-RESPONSE LOG DIABLO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision 650 Lines The phrase "discrete CDF of all logic tree branch combinations and Lines 1209-1210 Text revised to clarify meaning. 1101-their weights" is not clear. Please clarify (e.g., it would be clearer to Line 1286 1102, say something like '"discrete CDF of all weighted logic tree branch Lines 1 3 76-1377 Lines combinations" if that is the intended meaning). 1165-1166. and Lines 1243-1244 651 Line It is understood that the '"preferences'" identified in this paragraph and Lines 1239-1272 Text added to state judgments behind the allocation amounts. 1130 the next two paragraphs are implementing the two principal bases for the allocation discussed in the paragraph starting with Line 936. However. the reader needs to have a better idea of how the application of the bases is applied in each case discussed in these three paragraphs. For example, why does the Tl Team have a preference that the Shoreline fault slips either along or as part of the Hosgri fault? Is it the least complex topology for accommodating slip? More consistent with analogs? Likewise, in the next paragraph. why is 92% allocated to reverse-only rupture sources? The technical bases for the allocation amounts need to be given, especially because they are based on expert judgments. It is comparable to providing technical justification for the weights assigned to logic tree branches: there needs to be some basis given in the text or the decision will look arbitrarv. 652 Lines Please consider changing sentence to: The remaining slip rate is Lines 1261-1264 Text revised as suggested. 1134-allocated approximately evenly between the shorter (OV-03) and 1136 longer (OV-04) complex ruptures whereby the Shoreline fault source ruptures as part of multi-fault complex rupture involving both strike-slip motion and reverse or reverse obliaue motion. 653 Line Why is OV-05 at the top of the list in the legend? Figure 9-11 This is a typo in the figure. Explanation changed to correctly 1161 state H-05 for the top of the list. Figure 9-10 654 Line For clarity, spell out numbers in this paragraph as the get lost with the Lines 1215-1221 Text revised to list in bullets for clarify 1173 other numbers. Lines 1294-1301 655 Line H-05 -This should be 23% of Shoreline fault slip budget and then table Line 1307, Table Text revised to correct a typo (23% is correct value for H-05. 1185 for the SW model will sum to 100% 9-13 656 Line Please explain -SW-06 source of 0.086 is 100% of total budget for Line 1307, Table Footnote added to table to explain that the Los Osos is a 1185 Los Osos source. but is listed at 45% 9-13 backthrust in the SW model and is not fully seismically coupled. Thus the 45% total signifies 45% of the total slip rate is released seismoaenicallv; the rest bv other mechanisms. 657 Lines 0.09 mm/yr is not 45% of 1.9 mmlyr, it is 4.5%. Is there a typo here? Lines 1 340-1342 Text revised to correct a typo (1.9 mm/yr was corrected to 0.19 1215-Please clarify. mm/yr) 1216 COMMENT-RESPONSE LOG DIABLO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision 658 Line "The total slip rate of less than 0.09 mm/yr is approximately 45% of the Lines 1340-1342 See responses to comment numbers 656 and 657; text and 1215 geologic rate of slip of 1.9 mm/yr attributed to the Los Osos fault in the and Table 9-13 table modified for clarity. SW Model (Section 8.5)." Total is listed as 0.09 for Los Osos in Table 9-13 -please make consistent 659 Line Please expand the technical argument supporting the 0.45 coupling Lines 1345-1359 Text added to provide the rationale for the coupling values. 1217-coefficient for the Los Osos Fault in the SW model, and the 0.57 Lines 1435-1447 Examples of structures where structural growth probably 1220, coefficient for the San Luis Bay Fault in the NE model. especially any occurred seismically similar to what the Tl T earn en vis ions for and empirical support. For example, if there are geologic analogues that these backthrusts. 1290-favor decoupling of approximately this magnitude, please cite. If this 1297 value is a source of significant hazard sensitivity, please explain how the SSC model accounts for uncertainties in the coupling coefficient. If it is not a source of significant hazard sensitivity, please state that and cite the hazard sensitivity analvsis that establishes that fact. 660 Line Field et al.,2014, does not appear in the list of references. Line 1345 Citation changed to Field et al. 2013. 1220 661 Lines Spell out numbers in this paragraph as well, for clarity. Lines 1384-1391 Text revised to show as bulleted list. 1251-1256 662 Line "Combined, these rupture sources accommodate approximately 0.09 Line 1397. Table Footnote added to table with explanation for discrepancy 1290 mm/yr of seismogenic slip rate on the fault, or approximately 57% of 9-15 between total slip rate allocated to rupture sources and the total 0. 16 mm/yr slip rate attributed to the San Luis Bay fault in the geologic slip rate on the fault source. NE Model (Table 9-15: Section 8.6)." Allocated 0.092 total slip for San Luis Bay Fault in Table 9-15 not 0.16 mm/vr -please make consistent. 663 Lines Consider including the slip rate CDF information in a caption or the Figures 9-10 to 9-See Comment 671. Edits made to figures. 1313-notes for each of these types of figures. 15 1314 664 Line Hosgri +SW Models and Hosgri +NE models do not add up to 100% Line 1484. Table Typo corrected. 91 % of total now shown for top row on all 1333 as shown in Table 9-17. 9-17 three models. Table 9-17. 665 Line Might want to add supporting arguments why this higher-than-target Lines 1510-1514 Text added to cite Workshop 1 and chapter 14. 1356 slip rate on the Hosgri fault north of the DCPP will not meaningfully affect the hazard results for the DCPP. 666 Lines Please complete these citations. Lines 1518 and Citations checked and are complete 1406, below 1473, and 1477 667 Table Please clarify why the western reach of the Hosgri fault has a negative Lines 1497-1500 It shows slip rate transferring westward from the main Hosgri-9-17 slip rate. Cross-check this with lines t 344-1345 and clarify what/how it San Simeon fault zone to the Piedras Blancas via the western COMMENT-RESPONSE LOG DIABLO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision was done. reach. Text provided and cross-reference to section 5.2.1. 668 Figure Is it really negative vertical offset? Subsidence? Plus, technically, Figure 9-2 Points taken, but no change. Figure is directly from Wesnousky 9-2 offset is a strike-slip term. (2008); no reason to extensively modify this other citation, as it's not germane to this study 669 Figure The arrow showing the northern extent of rupture in Yeats' figure is Figure 9-3 No change. The arrow is meant to point to the thicker black line 9-3 misleading, as both the 1940 and 1979 ruptures extended north of this that shows the extent of the 1979 rupture. It is not meant to point. show the northern extent of the rupture. 670 Figure The note on the figure states that two dominant fault zones are shown Figure 9-8 The phrase '(thick black lines)' has been deleted from the note. 9-7 by thick black lines. It is confusing that, for the most part, these black The following sentence names the two dominant fault zones. lines are covered by green or yellow lines showing other attributes (also true in Fletcher et al.'s published version). Please clarify this issue in the fiaure note. 671 Figure An explanation is needed with the figure that the individual rupture Figures 9-10 to 9-Note added to figures as suggested 9-11 source CDFs sum to the Lognormal SLB CDF 15 672 Figure The Hosgri slip rate CDF (solid black curve) in panels a and c of Figures 9-10 to 9-Word Discrete removed, even though this is technically correct 9-9 Figure 9-9 is labeled "Discrete Hosgri GDF." But it appears to be a 15 (discrete CDFs from the Monte-Carlo simulations -10,000 through continuous CDF, and that is also the impression left by Section 8.3.7. make a smooth GDF) 9-14 Please clarify or correct the figure label. Same comment applies to the CDF plots for other faults in Figures 9-10. 9-11, 9-12, 9-13, and 9-14. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT PPRP COMMENTS AND Tl TEAM RESPONSES, CHAPTER 10 Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision CHAPTER 10-Magnitude Distribution Models 673 Line 7 Isn't the shape actually defined by the magnitude PDF. while the MFD Lines 14-15 and We are using the magnitude PDF as generic shape. Shape is actually incorporates the seismic moment rate? 27-28 modified based on Mchar, etc. values. The term MDM, which was incorrectly used in this paragraph and latter sections of the report has been corrected to *maonitude PDF(sJ' 674 Line 40 Might qualify this statement to indicate "earthquake magnitudes that Line 47 Text revised to add qualifying statement as suggested. give rise to significant ground motions." It might be argued that the historical/instrumental record provides a pretty good basis for assessino the rates of M3 earthouakes. 675 Line 50 Within the WAACY box, doubly-tuncated should read doubly-Line 57 Text revised to correct spelling of 'truncated'. According to Table truncated. Technical Editor. a hyphen is not needed where adjective ends 10-1 in .. ly. 676 Line Please state what lengths would typically be hypothesized to be Line 66 This sentence has been deleted. The discussion is reserved 61-62 characteristic, and provide justification or a reference that does so. Or, for later in the chapter (Section 10.2.3) if that discussion is provided elsewhere in the report. please provide a specific {chapter, section number) reference. 677 Line 79 This sentence appears to be a direct contradiction of sentence Lines 83-85 You are correct. They are aleatory in the model beginning on line 520. Please rectify this apparent contradiction or The text was revised to clarify this. explain why it is not actually contradictory. 678 Line 84 Here and elsewhere in the text. this should be termed the Lines 91, 98, Text revised as suggested. "characteristic earthquake model'". 109,444, 483, 524, 656 Tables 10-2 and 10-4 Figures 10-1 and 10-4 679 Line Please improve this explanation of conditions for use of the Line 103 This sentence has been deleted. The discussion is reserved 97-98 characteristic PDF, because the explanation seems more or less for later in the chapter (Section 10.2.3) circular without a quantitative statement of the rupture-source length criterion. 680 Line The word "bur is a source of confusion, because it suggests that the Line 109 Text revised as suggested. 104 second clause is going to qualify the first, whereas the second clause actually seems to directly reinforce the first. Please check whether the intent of the sentence would be more efficiently communicated if the word were chanoed to and."' 681 Line And what are the disadvantages? (Difficulties in assessing the various Lines 128-t 33 Text revised to clarify that the possible disadvantages are that 127 parameters?) the W AACY model contains many parameters and has not yet been implemented in previous PSHAs. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 682 Line The phrase "the logic tree of W AACY parameters values and weights Lines 156-158 Text revised to clarify. 150-are correlated with" is unclear (e.g., does it mean "the parameters 151 values and weights in the logic tree are correlated with"?). Please rewrite the sentence to clarify its intended meaning. 683 Line Suggest a section title that is more specific to Mchar and Mmax. Line 159 Text revised as suggested. 154 Otherwise. the section could refer to the selection of the particular type of maanitude to be used (Mw, Ms, etc.). 684 Line Check spelling on paleoseismic. Line 186 Spelling corrected. 183 685 Line Please consider rephrasing -This prediction is supported to an extent Line 192 Text revised . 197 by empirical data. which include no step-overs wider than 4 km (Wesnousky. 2008) or 5 km (Lettis et al., 2002), but not in detail, as Wesnousky (2008) found that among step-overs less than 4 km wide. there was no relationship between step-over width and likelihood of arresting rupture. 686 Line The phrase "energy in rupture momentum" is not physically Line 207 The phrase *energy in rupture momentum' has been change to 204 meaningful. In fact. at least in the limit of a very narrow process zone, 'kinetic energy during rupture* a rupture front does not carry any momentum at all. in the sense that rupture speed can respond instantaneously to changes in stress. frictional resistance, etc. Please substitute more aoorooriate lanauaae. 687 Line Soften -replace indicate with suggest Line 210 Text revised as suggested. 208 688 Line This would read more clearly with a comma after "lengths". Line 210 Text revised as suggested. 208 689 Line "where fault traces more abruptly bend" would read more clearly as Line 214 Text revised as suggested. 212 "bend more abruptly". 690 Line Please consider replacing "than where they are less pronounced" with Lines 211-216 Text revised to clarify. 214 "where offsets or bends are more pronounced" 691 Line "The maximum M ... , value for all Primary fault sources bypasses Lines 228-231 Text revised to clarify that all Rupture Models include rupture 222-essentially all proposed segment boundaries." Are these wall to wall sources that involve Primary faults that link with Hosgri, San 223 ruptures? Please explain. Gregorio, and San Andreas faults to MT J .. 692 Line Please change "materially" to substantially -remove any material Line 247 Text revised as suggested. 239 properties confusion 693 Line Replace "Points" with Features Line 255 Text revised as suggested. 247 694 Line Please check for missing verb on this line. Lines 293-297 Text revised to address verb issue 286 695 Line Delete "and" between intersection and had for clarity Line 294 Text revised as suggested 287 696 Line consider replacing "considered lesser in degree" with Line 304 Text revised as suggested. 296 "less well develooed" COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 697 Line This line is unclear. What are alternates? Please check whether the Line 328-331 Text revised to clarify. 300 word "alternatives" (rather than "alternates") better corresponds to the intended meanina on this line. Or is it alternative traces? 698 Line Faults joining? The activity of faults that intersect the main trace is Line 313-314 Text revised to clarify 303 low?? Please clarify. 699 Line Replace "short" with finite Line 318 Text revised as suggested. 307 700 Line Please make it clearer what is meant by "to define the limits of soft Lines 323-328 This sentence was changed to emphasize that the purpose of 314 segment boundaries along fault sources." allowing ruptures to float is to account for uncertainty in precise locations and sizes of potential segment boundaries. This simplification is justified because this is a site-specific SSC model. 701 Line Please insert capture in front of magnitude Line 340 Text revised as suggested. 330 702 Line Please check whether the word "given" (rather than provided") would Line 341 Text revised as suggested. 330 better convey the intended meaning. 703 Lines The range of magnitudes predicted by the alternative rupture lengths Lines 344-347 Sentence rearranged as follows to clarify the meaning 333-considered using any single magnitude-scaling relation is much The range of magnitudes predicted by any single magnitude-336 greater than the range of magnitudes predicted for any single rupture scaling relation for the alternative rupture lengths considered in length (or area) from a suite of magnitude-scaling relations. This the Diablo Canyon SSC model is much greater than the range sentence is difficult to parse. Please rewrite and clarify this statement. of magnitudes predicted for any single rupture length (or area) from a suite of maanitude-scalina relations. 704 Line Delete extra do" for clarity. Line 344-34 7 Text modified to eliminate typo .. 340 705 Line Please explain why the SSC forward-modeling approach implies Line 347 Reference to the implications of magnitude scaling 340 weaker sensitivity to magnitude-area scaling compared with the relationships for UCERF 3 is removed from this discussion. inversion approach of UCERF3. The UCERF 3 analysis is not what guides our approach to characterizing magnitude uncertainty. 706 Line "This review included other evaluations of alternative scaling relations Line 353 Text revised as suggested to delete sentence. 347 and their relative merits for use in seismic hazard analysis (e.g., WGCEP, 2003; Shaw, 2013a; Stirling et al . 2013)." Redundant -olease remove. 707 Line Use a comma after SSC model, rather than a colon. Line 364 Text revised, but semi-colon used based on recommendations 360 of technical editor 708 Line "strike-slip Hosgri fault, lesser but significant" is unclear. Perhaps Lines 365-367 Text revised 361 insert whereas" before lesser? 709 Lines Abbreviated HB02 -please add "as so it reads "abbreviated as HB02" Line 371-373 Text revised as suggested; other abbreviations added as well 367, 368, 369 710 Line Abbreviated as??? How is this designated? Line 375 Text revised to specify abbreviation as requested. 370 COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 711 Line EB02 should be EB03? Line 381 Text revised to change to EB03. 376 712 Lines HB08 data set looks more comparable with YM11 than NGA-W2 data Lines 383-387 Text revised to clarify that HB08 does look more comparable 378-set? with the YM11 dataset, instead of the NGA-W2 dataset as was 380 previously written. 713 Line EB02 should be EB03? Line 390 Yes. Text revised to correct. 385 714 Line Here you use a 12 km depth for characteristic ruptures, but the implicit Lines 445-448 Text is revised to clarify that characteristic earthquakes are 438 assumption is that these only apply to shorter faults, and not the interpreted to occur on any of the Primary or Connected fault Hosgri. Perhaps it would be good to make this clarification here rather sources, and that the rupture width for all characteristic than below (lines 451-453). earthauakes is 12 km. 715 Line The argument in this sentence appears to be that it is acceptable to Lines 462-468 A reference to sensitivity analyses presented at Workshop 2 447-under-represent aleatory variability of magnitude because epistemic testing fault length is provided. 450 uncertainty is broadly sampled. Please justify quantitatively why this The text is modified to clarify that the Tl Team judges that the tradeoff is acceptable (for example, this might be done by referencing wide range of aleatory variability built into the model through available hazard sensitivity analysis). the use of numerous rupture sources in addition to the epistemic uncertainty incorporated through consideration of alternative estimates of Mmax justify this simplification. 716 Lines Please provide supporting evidence for the stated hypothesis that only Lines 445-448 Text revised to cross reference to Section 7.2.1. where 451-the largest earthquakes rupture with depth greater than the depth Line 453 transient deepening is postulated to be generated by high 455 limits inferred from background microseismicity. strain rates of the main shock strain rate. 717 Line The wording "depth of crust derived from proxies such as the D90 or Line 446-453 Text revised to correct. These concepts are more fully 454 D95 values" implies incorrectly that D90 or 095 can be interpreted as discussed in Section 7.2. 1; the revised text refers the reader to proxies for the depth of the crust. They are proxies for depth of the this section of the report. seismogenic zone, and perhaps for the brittle-ductile transition depth. Please make aonrooriate chanaes. 718 Line Please state the technical justification for selecting M 7.3 as the Lines 452-457 Text revised to clarify the cut-off magnitude (M 74) used (ie. 458 threshold for rupture deeper than 12 km. >the largest Mchar earthquakes included in the model) The Tl Team judges that characteristic earthquakes should adhere to the depth limits indicated by consideration of 090 and D95, and the presence of an apparently unfaulted slab. Only the rare larger events are interpreted to rupture beyond that depth. These analyses are more fully discussed in Section 7.2.1; the revised text refers the reader to this section of the report. 719 Line The figure uses 130 km. Please make consistent. Figure 10-4 The figure is corrected. 468 720 Lines This aleatory variability is considered by the Tl Team to represent a Lines 485-490 Text revised to clarify. 471-combination of magnitude variability given the rupture area and rupture 474 area variability of the characteristic earthquake given the approximate definitions of the soft segmentation points used to define the characteristic ruptures. Please rewrite this with one less "given", as it is difficult to parse. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 721 Line Don't capitalize The Line 496 Sentence modified to eliminate typo .. 480 722 Lines This sentence is confusing -please rewrite for clarity Lines 501-505 Text revised to clarify. 485-489 723 Line Was any consideration given to the manner in which the exponential Lines 507-514 Text revised to cite other studies that showed the exponential 490 relationship would need to be implemented? Studies of other active model does not provide a good fit to seismicity or paleoseismic faults show that the observed seismicity occurring within a narrow data. zone along a fault is not compatible with the exponential shape of the recurrence curve unless a very large Mmax is adopted (e.g., Hecker et al. 2013). Was there any attempt to examine the recurrence distribution along the Hosgri fault or other faults based on seismicity? The same arguments made below between the exponential and WAACY model with respect to repeated slip at a point could be made here to justify the zero weighting of the exponential model for Category A rupture sources. 724 Line 130 km in the figures -please correct to a common value. Figure 10-4 Figures were updated to clarify that all type A rupture sources 500 are less than 100 km. Type B rupture sources are greater than 100 km 725 Line Please consider whether the challenges to the exponential PDF Lines 541-544 Agreed. Good suggestion. UCERF3 tried unsuccessfully to 504 identified by UCERF3 (Field et al., 2014) constitute another factor (in implement GR fault MFDs. They found that the fault system addition to the Hecker et al analysis) in the Tl Team's judgment to give was too characteristic to make them work. that PDF substantially lower weight than given the WAACY PDF. Text has been modified to cite Field et al. (2014) who do acknowledge the Hecker et al. (2013) results and issues with G-R for faults. 726 Line Please insert paleoseismic before data Line 531 Text revised as suggested. 504 727 Line Replace "confidence" with determined Line 533 Text revised as suggested 506 728 Line The inclusion of Figure 10-5 with virtually no accompanying Figure 10-5 An explanation has been added to Figure 10-5 509 explanation in the text or caption is extremely confusing. The figure makes reference to undefined "Group A," "Group B", and "Group C". and the reader naturally associates these with the "Category A." "Category B," and "Category C" magnitude PDF categories that have just been introduced in the text at this point (only to eventually discover that there is no such connection). Please either make some use of the fiaure, with a full explanation, or delete it. 729 Line Please define "available data." There is an implication that these Line 541 These endorsements of the exponential model did not consider 514 endorsements of the exponential distribution for faults were made after the final version of Hecker et al. (2013) because they pre-date giving due consideration of the Hecker et al. data regarding slip per that paper, but they did attempt to reconcile paleoseismic data event. What types of data were considered by these authors and is ii and seismicity data near faults. Parsons and Geist point out possible that they would endorse the W AACY model over the that reconciling the two datasets for the southern San Andreas exponential model if they had considered all "available data" presented fault is achieved by either ( 1) considering seismicity within a by Hecker et al.? volume around a fault 10s of kilometers wide, or (2) considerina temooral chanaes in seismicitv rates, oerhaos due COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision to regional effects such as stress shadows that follow major earthquakes. Text modified to describe the data tvoes considered. 730 Lines A potential criticism of the maximum magnitude model for hazard No change No change required. While we acknowledge that this may be a 516-analysis is that smaller magnitudes are not provided for in the concern in more traditional SSC models where the maximum 517 distribution for each rupture source. It could be noted that the use of magnitude model is given weight as the appropriate model for the model in conjunction with seismic source zones to account for a single fault source. in this model it is being applied to only smaller magnitude seismicity ensures that all magnitudes smaller than certain rupture sources, on a particular fault source. In all the maximum are included. cases, the fault source also produces small magnitude earthquakes as part of other rupture sources. Adding text to explain how smaller magnitude events are accounted for in this section would be more confusing than helpful. 731 Line The statement about Category C rupture sources is that "aleatory Lines 545-556 Text revised to clarify that magnitude variability for Category C 520-magnitude variability is introduced by involving more than one rupture sources is aleatory. 522 scenario" with defined relative frequencies. But Line 79, also in regard to Category C rupture sources, states that "epistemic uncertainty is incorporated by considering alternative scenario earthquakes." Please explain why this is not a contradiction, or make changes to provide a consistent description of the intended treatment of variability in the Category C rupture sources. 732 Line Insert model after UCERF3 Line 570 and 571 This sentence and preceding one were revised accordingly. 536 733 Line "at random" may read better as "randomly" Line 591 Text revised as suggested. 557 734 Line "the left end"?? Left end of what? One end? South or north end? Lines 599-604 Text revised to clarify that left and right are respective of the 568 There is no "left" or right ends of a fault without a reference frame. *observation point' The descriptions 'left' and 'right' are left purposely generic to avoid confusion with faults of any specific direction. 735 Line Same comment. "on the right" could read "towards one end" Lines 599-604 Text revised as noted above. 570 736 Line "of 60 km long" -this would be clearer with a hyphon between km and No change No change required based on following recommendation of 572 long Technical Editor Note that we don't hyphenate this kind of compound when there is an abbreviation-as explained in the Chicago Manual of Style. 737 Line Please write text and one or more equations explaining precisely what Figure 10-6 Equations have been added to clarify what is being plotted, 574 quantity is plotted in Figure 10-6 and how that quantity is applied to the Lines 590-663 and how Figure 10-6 relates to Figure 10-7. Briefly, 10-7 is magnitude PDFs (e.g .. what is a "reduction rate"-the term "rate" logarithmic. The y-axis on Figure 10-6 has been changed to implies it has units, yet from the range of values in the plot, it appears 'Geometric reduction rate' to be dimensionless; assuming it is actually a dimensionless adjustment factor, what quantity does it multiply to implement that adjustment? How do you go from the curve in Figure 10-6 to the results in Figure 10-7; how does the quantity in Figure 10-6 combine with the factor LIL,?)_ COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 738 Line Please give a precise definition of "geometric reduction** and how this Lines 590-610 Edited in the course of reply to comment 737. 584 term is distinguished from, and related to, the terms "rate reduction" labeling the axis in Figure 10-6 and "reduction rate" introduced on Line Figure 10-6 574. 739 Line It is stated on this line that the exponential model leads to a point MFD Lines 638-641 Text revised to clarify that once they reach a certain size, the 592 that has a "gentle upward deflection" for larger magnitudes. There is ruptures cannot float beyond the end of the fault. This no upward deflection on the point MFD (blue) curve in Figure 10-7a effectively decreases the geometric reduction factor. "upward (nor is ii clear why one would be expected). Please clarify deflection" was erroneous. For the exponential model, this effect is a downward deflection. The text has been revised to clarify this. 740 Line Please explain the phrase **arithmetic sum by magnitude Lines 662-663 Revised text to explain the slip rate matching and clarify the 611 next step of summing across rupture sources. 741 Line Please check whether the phrase "alternative earthquake scenario Lines 677-678 Text was revised to delete the word 'alternative' from the 623-magnitudes and frequencies for complex and splay rupture sources" phrase 'alternative earthquake scenario'. As noted in the 624 actually communicates what is intended. If so. please explain how response to Comment 677, the earthquake pairs represent "alternative" scenarios can be reconciled with the sentence beginning aleatory variability (i.e., both occur with some estimated on Line 520 that says "Aleatory magnitude variability is introduced by relative frequency). involving more than one scenario earthquake pair, whereby the relative frequency of the scenario earthquake pair is defined." The scenarios are either "alternatives" or they occur collectively with some "relative frequency," and it is not clear how both statements can be correct. 742 Lines Figure 10-4 shows 130 km as the break between category A and B Line 691 The figure was corrected to show that the break is 100 km. 636-rupture sources. 637 743 Line It is not clear what is meant by "alternative aleatory logic tree branch . Lines 706-712 Text has been revised to clarify . 653 values." Table 10-5 refers to "scenario frequency, suggesting that all of the listed scenarios occur on a single logic-tree branch and represent aleatory variability, not mutually exclusive alternatives. So please explain what the "alternative" logic tree branches are in reference to Table 10-5. The confusion about the status of the Category C rupture sources seems to be systemic in this chapter: Note the related apparent contradiction between sentences beginning on Line 79 and Line 520. and the related issue on Line 689 (with reference to Table 10-81 and Line 722 {with reference to Table 10-11 l. 744 Line Please explain how the assessment of the relative frequency of the Lines 710-712 A very crude magnitude scaling was adopted, in which large 655 scenarios relates to the shapes of the MFDs. What was the thought magnitude scenario events are judged to occur less frequently process used by the Team? than smaller magnitude scenario events. Text modified to clarify 745 Line "favors" instead of "favored? Lines 710-712 Word 'favors' was deleted in revised text in response to 658 Comment 7 44 .. 746 Line Same as comment for Line 623 Please check whether the phrase Lines 723-727 Text was revised to delete the word 'alternative' from the 670-71 "alternative earthquake scenario magnitudes and frequencies for phrase 'alternative earthquake scenario'. As noted in the complex and splay rupture sources" actually communicates what is response to Comment 677, the earthquake pairs represent intended. If so. please explain how "alternative" scenarios can be aleatory variability (i.e

• both occur with some estimated COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision reconciled with the sentence beginning on Line 520 that says "Aleatory relative frequency). magnitude variability is introduced by involving more than one scenario earthquake pair, whereby the relative frequency of the scenario earthquake pair is defined. The scenarios are either "alternatives or they occur collectively with some **relative frequency, and ii is not clear how both statements can be correct. 747 Lines II would be helpful to indicate where on the figures these segment Line 730 Text revised to cross reference to Plate 9-2 for maps showing 672-boundaries can be found. Perhaps add a column to the table what Tables 10-6, 10-9, locations of boundaries. 673 makes reference to the applicable figure. and 10-12 Tables 10-6, 9, and 12 were also modified to reference the fiqures that show how the segment boundaries were used. 748 Line Why is LC, HN, HD not a tier 1 as there is observed a pronounced Table 10-6, LC, This point is a first-tier boundary in the OV Model (although it is 674. difference in sense and rate of slip between the two faults? HN, HD boundary only a second tier boundary in the Hosgri MOM). The table has Table been corrected to reflect this. 10-6. 749 Table "South end of Little Pine fault"?? This fault strikes southeast -please Table 10-6, LP Text revised as requested. 10-6 correct the strike. 750 Table Different slip rate or difference in slip rate?? Please fix. Table 10-6, LO, Text revised as requested 10-6, LE LO, LE box. 751 Line Only double asterisk for SE** Table 10-6, SE Double asterisk was inadvertent. It has been removed 677 752 Line Suggest including "Rupture Source Magnitude PDF Category (rather Tables 10-7, 10-Revised heading to be "Magnitude PDF Category". 687. than just "Category") in this heading to remind the reader. 10, and 10-13 Table 10-7 753 Line Please provide some discussion of how the weights for Mchar and Lines 741-743 A discussion was added to the introductory text that precedes 687. Mmax were assessed. Lines 784-790 the table describing how the weights for Mchar and Mmax Table Lines 828-834 were assessed. 10-7 754 Line Same comment as for Line 653: It is not clear what is meant by Lines 750-755 Text has been revised to clarify. 689 "alternative aleatory logic tree branch values," given that Table 10-8 appears to describe relative frequencies, not mutually exclusive alternative models. Please explain how to interpret Table 10-8 in terms of alternative logic tree branches, and how that is consistent with the aleatory nature of the variability implied by the term "relative freauencv." 755 Line This would read more clearly with a comma after sources". Line 764 Paragraph was modified as part of technical edit 700 756 Line Same as comment for Lines 623 and 670: Please check whether the Lines 769-770 Text was revised to delete the word 'alternative' from the 702-phrase "alternative earthquake scenario magnitudes and frequencies phrase 'alternative earthquake scenario'. As noted in the 703 for complex and splay rupture sources" actually communicates what is response to Comment 677, the earthquake pairs represent intended. If so. please explain how "alternative" scenarios can be aleatory variability (ie .. both occur with some estimated reconciled with the sentence beginning on Line 520 that says "Aleatory relative frequency). maanitude variabilitv is introduced bv involvina more than one scenario COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision earthquake pair, whereby the relative frequency of the scenario earthquake pair is defined." The scenarios are either "alternatives" or they occur collectively with some **relative frequency," and ii is not clear how both statements can be correct. 757 Table "Postulated South end" -south should be lower case. Also, shouldn't SE box in Text revised as requested. 10-9, this be southeast end, as the fault strikes NW-SE?? This comment Tables 10-3, 10-6, SE .. also applies to other tables with identical verbage, such as Table 10-10-9, and 10-12 box 12 758 Table Same comment as above -the Little Pine fault has a NW-SE strike, so LP box in Text revised as requested 10-9, this should read the southeast end. This comment also applies to other Tables 10-6, 10-9, LP box tables that use identical verbage, as in Table 10-12 and 10-12 759 Table SH-HB marked difference in slip rate -Tier one? Tables 10-6, 10-9, Given the significant change in slip rate this property suggests 10-9 and 10-12 SH-HB it may be a first tier boundary. However, evidence for deflection of the primary Hosgri trace, or localized uplift or subsidence around this boundary is weak, suggesting it may be a second tier boundary. or a borderline case. In the SSC model. this boundary is treated both ways: many rupture sources end at this boundary. but some include characteristic rupture lengths that bypass it The tables have been modified to reflect this. 760 Table The hazard implications of the MS scenario that includes the Hosgri No change The hazard implications of this rupture source are considered 10-11. will need to be considered in Chapter 14. In particular, the implications in Chapter 14. Although preliminary sensitivity analyses (e.g .. SW-04 of assigning a 10% relative frequency should be discussed. Gregor, 2012) suggest that considering very large magnitudes box will tend to reduce hazard at the DCPP, the Tl Team judges it to be appropriate to assign a 10% frequency to the MS scenario for this rupture source. Given the low slip rate assigned to SW04, and the amount of moment consumed by a MS event, this event would be extremely rare. No change to the text of Chapter 10. 761 Table Fault is capitalized here, and small case elsewhere. Be consistent Table 10-12, SA Text revised as requested 10-12, box SA box 762 Table Please add fault after Wilmar Avenue, for clarity. Table 10-12, WB, Text revised as requested 10-12, SS, SF box WB,SS, SF box 763 Line There isn't any "description" provided in the table. Line 779 Correct. We have revised the text to state that the table 713 "provides" an assessment. .. 764 Line Please explain surface projection pattern for NL? Figure 10-30 The downdip projection of the Nipomo Lineament was drawn to 717 be truncated by a moderately to steeply east-dipping West Figure Huasna fault. This truncation was not used in Magnitude 10-30. scaling relationships for estimating magnitudes. The faults farther to the southeast are drawn to be more generalized. Given the distance and small hazard contributions of these faults, the Tl Team iudaes that these simolifications are COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision justified. 765 Line Same comment as for Lines 653 and 689: It is not clear what is meant Lines 794-797 Text has been revised to clarify. 722 by "alternative aleatory logic tree branch values," given that Table 10-11 appears to describe relative frequencies, not mutually exclusive alternative models. Please explain how to interpretTable 10-11 in terms of alternative logic tree branches, and how that is consistent with the aleatory nature of the variability implied by the term "relative frequency." 766 Line Same as comment for Lines 623, 670 and 702: Please check whether Lines 810-814 Text was revised to delete the word 'alternative' from the 737-the phrase *'alternative earthquake scenario magnitudes and phrase 'alternative earthquake scenario'. As noted in the 738 frequencies for complex and splay rupture sources" actually response to Comment 677. the earthquake pairs represent communicates what is intended. If so, please explain how "alternative" aleatory variability (i.e., both occur with some estimated scenarios can be reconciled with the sentence beginning on Line 520 relative frequency). that says Aleatory magnitude variability is introduced by involving more than one scenario earthquake pair, whereby the relative frequency of the scenario earthquake pair is defined." The scenarios are either "alternatives" or they occur collectively with some "relative freciuencv:* and it is not clear how both statements can be correct. 767 Line SH-HB Tier one segment boundary? Table 10-12 Same response as above (Comment 759). 742 The text is revised to clarify that this boundary is a borderline Table case and it is treated both ways. 10-12 768 Line No asterisk in Table 10-12 Table 10-12 Comment appears to be in error. 744 There are asterisks after the following table entries: SH,SS, BR NE-03. WB,SS,SF NE-07* LV,LB NE-07* LC, HN, HD NE-08* 769 Line Figure 10-36. Please explain -if the dip of the Los Osos is 60" -why No change The dip of the Los Osos changes along strike. See Figures 7-752 doesn*t the surface projection of the rupture parallel the fault? 26 and 7-27 that show the western part (LM) dips 50° and the eastern LV) dips so*. 770 Line Same comment as for Lines 653, 689:, and 722: It is not clear what is Lines 813-814 The word "Alternative" has been deleted. 756 meant by "alternative aleatory logic tree branch values." given that Lines 838-843 Table 10-14 appears to describe relative frequencies, not mutually exclusive alternative models. Please explain how to interpret Table 10-14 in terms of alternative logic tree branches, and how that is consistent with the aleatory nature of the variability implied by the term "relative frequency." 771 Line Tables 10-14-some descriptions (Faults) have main or splay written Tables 10-8, 10-The tables have been edited to clearly distinguish which fault is 762 in column but not all -please make consistent for all tables 11,10-14 main (or primary) and which is splay (or secondary). 772 780 Please specify (at least on the figure caption or figure notes) the Figures 10-43, Magnitude bins = 0.05 has been added to the notes on figures. magnitude bin size used for the incremental distribution (since the etc. curve does not appear to be normalized to unit magnitude increment),

COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision on this figure and other MFD plots (otherwise the incremental and cumulative plots cannot be reconciled). 773 Line This seems to be the first occurrence of the term "reduced source Lines 882-884 Explanation extended to clarify 798 MFD." Please define it (e.g., is it distinct from the Point MFDs in Figure 43?). 774 Line Figure 10-44 caption. "the rates for both subevents is the same" Figure 10-44 Caption corrected 803 replace is with are 775 Line Please clarify the meaning of "Hosgri source MFD." Line 891 Description updated to clarify that the shows the MFDs for the 805 collection of Hosgri rupture sources. 776 Line Might rephrase to indicate that these sources are characterized using Lines 893-894 Text modified as requested 807 the maximum magnitude PDF. Otherwise, it may be unclear what is meant by "simplified maximum magnitude sources." 777 Line Figure caption -please remove one "at the" in the phrase "at the at the Figure 10-45 Caption has been corrected 829 Hosgri subevent" 778 Line Figure 10-45 appears (based on the slope of left-hand extreme of the Figures 10-45 and The discussion in the text is focused on the general shape of 847 cumulative curve) to have been constructed with a magnitude bin size 10-46 the incremental curves as a means for understanding which of approximately 0.05 magnitude units, whereas uudging by the slope magnitude ranges are emphasized by which model, rather than breaks on the blue curve) Figure t0-46 appears to have been directly comparing rates from one model to another. constructed with a magnitude bin size of approximately 0.1 magnitude Notes have been added to the figures to clarify what units. If ii is the case that they were constructed with different bin magnitude bin sizes were used for each. sizes. please explain what normalizations were done to ensure that these curves are comparable. If the apparent difference in bin sizes is illusorv. please clarifv 779 Figure Correct the spelling of "strike" in the header for the top figure (a). Also, Figure 10-3 Corrections to the spelling are made. 10-3 why not use the same symbols for the models that are in common The only M-A relationships shown on both plots is HB14, and it between the two figure parts (a and b) is shown with the same symbol. The two WC94 relationships are different (strike-slip and reverse). 780 Figure Definitions of the dashed and solid lines in the Explanation are Figure 10-45 The figure has been corrected 10-45 reversed. 781 Line "or some other feature of the inversion solution (Page et al., 2014)." Lines 947 This phrase has been deleted in revised paragraph. 863 ? Please clarify some other feature 846 782 Line Please change is to are "the rates for both subevents is the same." Figures 10-47, 10-The figures have been corrected. 866 Please correct for all odd numbered figures that follow Figure 10-47 in 49, 10-51, 10-53, Figure this section. and 10-55 10-47. 783 Line Whether the ground motions will be higher or not is a GMC and hazard Lines 970-971 Text modified as suggested. 883 issue. It is suggested that the reader just be reminded that other line sources contribute to these scenarios besides just the Shoreline fault 860 oortion. 784 Line Replace is with are ? line number We could not find this typo. but we hope it was corrected by 973 given by PPRP the Tech Editor COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT PPRP COMMENTS AND Tl TEAM RESPONSES, CHAPTER 11 Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision CHAPTER 11 -Time Dependency Model 402 General Please review the chapter for notational consistency with Appendix. T1 for We will be standardizing on T1 he forecast interval seems to be the same thing as Tu in Appendix, for throughout 403 Line 8 rrhe first line is fuzzy in its meaning, Please improve the wording to mean Changed as suggested what you are trying to say: "Recurrence models can be divided into Line 13 categories, those that are time independent and those that are time '1ependent." 404 Line 10 What has been described is not a Poisson distribution (which would Changed as suggested. '1escribe the probability of n events occurring in a given time interval), but rather a Poisson process. Please use the more precise statement. Lines 13-15 405 Line 12 Please consider adding a definition of the hazard function, or referring to In these introductory section of the chapter we seek a Eq. 7 of the appendix for the definition. n/a more qualitative description. and reworded the sentence. rrhe hazard function is presented later in Chapter 11 406 Line 13 rrhis section discusses how time dependent models are considered but not rrhis is described in lines 28-30. We will promote the why. As noted. time independent models are typically used for site-specific paragraph to earlier in the introduction. PSHA purposes. Why is a time-dependent model being considered? Lines 10-12 Please provide additional discussion of the need for the consideration of a ime dependent model for faults and why the use of an equivalent Poisson rate is used, rather than a time-dependent PSHA. 407 Line 14 rrhis would be clearer if "models" was inserted after "most common" Line 21 Done 408 Lines 20-21 rrhe statement "time-dependent recurrence distributions are more Reworded to address the concern raised in the comment. K:;omplicated than the Poisson," implies that "Poisson" means "Poisson '1istribution," which does not make sense. If the intention is to compare the Lines 23-28 ime-dependent recurrence distributions with the exponential recurrence '1istribution (which characterizes the Poisson process). please make that K::lear. 409 Line 24 Might add something like, "particularly if there are other compelling reasons We've modified the description to improve the positive considering it." If there was no physical basis for a time-dependent basis to consider time dependence. The point here is that model and no data upon which to base it, there would be no justification for Lines 2-12 non-Poisson recurrence models should be considered if its use. hey cannot be ruled out, regardless of whether or not here is a physical basis for it. 410 Line 25 rrhe phrase "time-dependent fault recurrence" is incorrect. The occurrence reworded in addressing comments 406, 408 and Pt earthquakes can be time-dependent but faults don't recur over time Lines 2-12 1409 removing "fault" or changing fault to "earthquake" 411 Line 26 'The SSC recognizes ... " The SSC is now sentient? Do you mean the "Tl Reworded with changes responding to c.406-410. rream recognizes ... "? Please clarify what you mean here. Lines 2-12 412 Line 29 r.'ou included time dependent recurrence or recurrence models? Lines 2-12 Corrected with responses to comments 406-411. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 413 Line 35 Might be useful to say that this is done via seismic moment rate to account We added mention of the fault geometry directly, as *or rupture geometries. Lines 36-45 rupture geometries and moment rate are specific derivatives of it. 414 Lines 38-39 rrhe way it is described, the EPR appears to be a dimensionless ratio ("a Changed Rate to ratio. The EPR is a rate correction, and Factor that can be applied to the earthquake rate"). If this is a correct rightly understood as a ratio. understanding, please reconsider whether "Equivalent Poisson Rate" is an term, since the description in the text implies that it is not a rate Lines 43-45 at all, but a ratio of rates to be applied as a correction factor. If this is not a l'.;orrect understanding, please make the actual definition of EPR clearer. 415 Line 42 Unlike other chapters, this chapter is written in the first person. Suggest We wrote ourselves out of Chapter 11. using third person throughout the report. Line 48 416 Lines 42-43 'we review these data, and ranges of possible values where specific data rewritten are not available." Whal does this mean -it is unclear what these data" Lines 47-53 refer to when specific data are not available. Please clarify what you are In 417 Lines 48-49 Here it is stated that there are no data whereas earlier in the paragraph it is reworded from "no data" to "uncertain ranges". "limited data". Please clarify the intended meaning. Line 56 418 Line 55 Is there a hyphen missing in "site-to-source"? Line 63 !Yes. Revised , fixed. 419 Line 57 'available data available" -extra word here? Line 65 removed one. 420 Line 58 'slips per event" -do you mean "slip per event data"? Please clarify. Also Revised the previous sentence. and removed the note that displacement per event" is used in other places in this chapter Lines 65-66 in which the questioned phrase occurred. in Appendix EPR. If the meaning is the same, please consider changes o maintain consistency of terminology. 421 Line 62-63 'A trench at the lngley site shows activity in the late Pleistocene" but then rewritten to clarify. here is discussion of deformation (warping) in the past 2500 years and Line 69-76 1840 year-old deposits are faulted. These statements are incongruent. Please clarify. 422 Line 73-76 is a summary of the interpretations and there needs to be better page references to Lettis and Hall, 1994, have been referencing of the primary sources and/or sections of the report where the Line 70, 79 added. interpretations were developed. 423 Line 75 Please check whether "displacements" should be "displacements per 'displacements" says what we mean -several were and make any necessary correction. Line 83 measured, in the range stated. 424 Line 79 last sentence could be improved for clarity of intended meaning Line 87-89 Rewritten and developed to better give the interpretation. 425 Line 83-84 'recurrence intervals between 265 and 2000 years," sounds like there are to singular to fix the multiple sites reading. The multiple sites with abundant paleoseismic data. Do you really mean the Line 91 RI range is quoted from the paper. A page reference to on the recurrence interval falls in the range of 265-2000 yrs? he estimates has been added. 426 Line 89 'sample only the most recent few events" -do you really have the past few Modified to 'a few recent events'. (i.e., more than 2) earthquakes dated on the San Simeon fault and Los bsos faults? Please verify this statement. Line 99 COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 427 Line 89 Not clear what "both" refers to here, since there were multiple trenching Reworded to clarify the "both" and "sites" references along the Los Osos fault. Likewise, what are the "sites" are that are referred to below in line 91. Lines 98, 99 428 Lines 97-100 Is there a reason for specifying data types that currently don't exist? It It is not clear how this weakens the technical conclusions weakens the technical basis for the conclusions drawn. The conclusions were drawn in the absence of the Lines 107-111 ypes of data described here. The description helps to illustrate the types of data and the depth of investigation hat led to this anlaysis. 429 Line 99 'none of this sort" -are you referring to "this sort of data"? Please clarify Line 110 Reworded to say that for now these data are not 430 Line 108-112 rrhese statements about the effects of early historical earthquakes are fine We reworded including a closing statement of what how but they need context. Your basic argument is that there are early he mission record is understood as a temporal constraint of significant magnitude that damaged some of the Spanish Pn the improbability of a large event on the Primary faults. missions at significant distances. You need a concluding statement that this so that when you segue into the absence of such damage at the San Luis Obispo mission. it strikes home the argument that there have been no moderately large to large earthquakes affecting the region Lines 130-133 1772. Also, note that the location of the 2nd large 1812 earthquake (Dec. 22nd) is debated -Toppozada et al. (1981) place this on the SAF but his is a hotly debated topic among those working on the earthquake and its affects (i.e. tsunami, which has been found in Carpinteria, no direct and evidence found yet in paleoseismic exposures at Frazier Mountain, although they pushed hard to make a case, at first) 431 Line 120 Suggest adding "occurred" after larger. Line 132 432 Line 126 By saying that "it is likely that the local completeness level is actually potentially confusing. Reworded. lower", it sounds like less complete but you likely mean more complete. Line 139 Please clarify. 433 Lines 127-What is the reason for the different weights? Lines 143-145 is added to say that the weights reflect relative 129 h"I Team confidence in the two comoleteness dates. 434 Line 138 Please correct "cumulative density function" to read "cumulative distribution rt'es, done. *unction." Line 154 435 Lines 139-It is not clear that 0 is singular or plural, or what 0 actually signifies. This rrhe references to theta drew from more formal 141 needs more explanation. and a good definition of 0. nla references, and are unnecessary here. Theta has been 436 Line 177 rrhe correct statement is that the variate assumes only non-negative reworded rvalues, i.e., its support is the non-negative real line (the current wording Lines 182-187 implies only that the distribution itself is non-negative, which is true but not informative). 437 Line 185 Remove "is" Line 190 pkay 438 Line 186 Do you mean to say it doesn't depend onµ as a mean parameter, or that it 'mean parameter is correct. "mean parameter" is a depend on the mean of Line 191 for COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 439 Line 192 In reference to the phrase "less than what Poisson rate," please specify that Reworded from Poisson rate to specify the exponential he comparison is with the Poisson process that has the same long-term Line 195 k:listribution of the same long-term rate. mean recurrence rate that the given lognormal model has, if that is the intended meanina. 440 Line 193 Not sure what is meant by "anticipates". Please explain or choose a better is closer to the intended meaning than the word. Line 197 we put in by request. 441 Line 194-195 'we do not know the times of the most recent events for any ... " Earlier, you Reworded. The original state of knowledge was laid out the paleoseismic data and discussed recency of faulting on the Los imprecise. bsos fault (1840 rcYBP, line 72), and you discuss recurrence intervals on he San Simeon fault (lines 84-85), which imply some information on past Lines 197-200 l:!arthquake timing. Perhaps this lack of data needs to be better explained and better summarized as it leaves the reader confused as to what we know and what we don't know. 442 Line 196 If tMRE is treated as a random variable please state that explicitly. Reworded here to describe tMRE as known only as a Line 199 range. A line is added also to point ahead to how tMRE is incorporated. 443 Line 197 'The choice of functional form in time dependence is also unknown." As We removed "choice of'. you are saying the "choice" is unknown. Please restate. Line 201 444 Line 211 'Coincides with the data estimate" is vague as to whether the aperiodicity is Matthews et al. (2002) make the distinction; this wording pr is not the CV. If ii is the CV, please say so explicitly, if it is not. please was to respect their distaste for *'coefficient of variation" in what it means that it "coincides with the data estimate" of the CV Lines 209-214 *avor of "aperiodicity". "data estimate of the CV" was also yet is not the CV and why this distinction needs to be made. computational distinction made by Matthews. The rewording should put the terms on more familiar ground. 445 Line 212 Remove *'wide" Line 212 rrext edited as requested. 446 Line 228 Please justify why the 3 lime-dependent distributions plus the exponential Explanation is added above the definition of the lognormal k:listribution are a reasonable representation of the center, body and range Lines 439-464 k:listribution, above former line 220. Pf recurrence models. 447 Line 259 Please provide the technical justification for the DPE distribution in Figure explanation al paragraph length has been added 11-3, or provide a specific reference(s) (chapter or appendix, and under section 11.3, Logic Tree. Placing the explanation number) to the part of the report where the justification is Lines 439-464 near original line 259 would not be preferred because k:liscussed. parts of the technical justification are developed in the EPR discussion. 448 Line 260 Please state briefly what is meant by "fault distribution point" and give a !Yes, Hosgri slip rate was intended. We reworded to reference to the sub-section of Chapter 8 where it is defined K::larify, and added a reference to the Hosgri rate CDF. (however, a search of chapter 8 returns no match for fault distribution point"). Alternatively, if the meaning is just the 8.5, 50, and 91.5 percentiles Line 260 the GDF for Hosgri slip rate, please say so explicitly. In any event, if here is to be a reference lo Chapter 8 it should be made specific as to (and perhaps figure number). 449 Line 271 It appears that the correct joint probability is that of L TM and tMRE, not Describing the weighting surface as joint in L TM and L TM and S(tll TM) (in fact, the latter is a distribution, isn't it, not a random Line 271 MRE is better. The distributions of tMRE are given by the tvariable?). And joint probability of (L TM,tMRE) would be consistent with S(tMREILTM). Figure 11-5. Please review and correct the text if necessary. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 450 Line 272 Please provide further explanation of Figure 11-5. Are these plots to be Further explanation has been added. The joint probability interpreted as joint probability density plots? If so. why does the area under in Figure 11-5 has been normalized to its peak he function obviously exceed 1? Is each such joint probability density so the contours can be read as relative weights or *unction (if that is the correct interpretation) specific to a particular slip-rate as regions from which more or less of the CPR Some (not all) of this is cleared up after study of the appendix Lines 271-288 weighting has been drawn. material, but the explanation in this chapter needs to be self-contained to be comprehensible without familiarity with the appendix. 451 Line 274 Same comment as for Figure 8 of appendix: The horizontal axis in Figure 5 In Ch. 11 the comment is understood to apply to Figure is labeled "Equivalent Poisson Rate (and EPR is indicated in the caption), 11-6. "Ratio is intended. Text has been added earlier in but the text seems to indicate that this axis represents the random variable he section to explain that the CPR is a mathematical CPR, not the estimated value EPR. and this interpretation is reinforced by and that the EPR is the CPR distribution after he fact that the plot is presumably showing the CDF of a random variable Lines 228-232 weighting across L TM. tMRE. (i.e .. CPR). Please review and modify as necessary to make the text and Figure 5 consistent, and to make clear any conceptual distinction between CPR and EPR. 452 Line 279 Please clarify the meaning of the phrase "relative to a Gaussian rrhis detail was unnecessary for explanation of the EPR approximation" in this context. The Miller and Rice method minimizes and removed. misfits to the low-order moments by applying the moment-preserving Lines 288-289 properties of Gaussian quadrature. In what sense can this be thought of as minimizing "relative to a Gaussian approximation"? 453 Line 286 Please provide discussion and/or references (to external documents or to was added plus an additional figure showing report section(s)) justifying that the proposed CV weighting adequately Lines 289-327 CV values for well-studied paleoseismic sites. represents the center, body and range of technically defensible interoretations. 454 Line 323 rrhe verb "is" refers back to differences, which is plural. Please change to kl one 'are" Line 361 455 Line 333 Please clarify the meaning of "less coherent as a source of hazard." Lines 366-371 Coherent in the sense that they would not rupture as one source as the SAF does. Reworded to a simoler line. 456 Line 336 Scharer et al. (2014) does not appear in the list of references. Line 602 Reference is at original line 569. Perhaps it was missed somehow? 457 Line 347 Please review the appropriateness of the term "marginal distribution" in this Found "marginal distribution" on original line #405. (and consider whether it makes sense to refer to a marginal *conditional distribution" was intended. and the text klistribution-as opposed to a conditional distribution-as being revised. 'conditioned on" a value of one of the variates). The text does not make that any variate has been marginalized, but rather seems to imply that Line 381 he initial joint PDF has been defined as delta(tMRE-To) x p( L TM). If the erm "marginal distribution" is actually the correct one, please explain why .. 458 Line 349 rrhe correct figure reference for displacement per event models appears to Revised. With an added figure the reference becomes be 11-9 (not 11-8). Please check this. Line 383 11-10 459 Line 349 Please indicate (in both the text and figure caption) which recurrence model Lognormal model. References added. (lognormal, BPT, Weibull) is used in the construction of the results in Figure Line 383 11-9. 460 Line 351 Shouldn't observation be plural? Line 386 Pkay. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 461 Line 360-363 rrhe explanation of the averaging is ambiguous and can only be worked out Reworded to clarify that SAF1 weighted mean results hrough reverse engineering from Table 11-3. Please rewrite to make it *rom each recurrence model have been averaged to 1'.:lear whether: (1) only SAF1 is used in the final averaging; (2) a separate l'.lbtain the final SAF EPR estimate. mean is taken for each of the three selected percentile points; and (3) those Lines 394-396 means are weighted by 0.25, 0.5 and 0.25, for the 8.5, 50, and 91.5 percentile cases, respectively, to form a final weighted mean EPR. 462 Line 362 Please give the rationale for the 0.25, 0.5, 0.25 weighting (referring to Miller Removed in the rewriting for Comment 461. Numerically '1nd Rice if that is appropriate). Lines 283-286 weight values were added earlier with the first reference In 463 Lines 368-Please explain how the conditions (other than degree of hazard sensitivity) we simplified the discussion to focus on hazard 371 klescribed here apply differently to the non-SAF regional faults than they do Except for the SAF. regional faults together o the Primary (Hosgri. Los Osos. Shoreline, and San Luis Bay) faults. If a small fraction of one percent of total hazard. here is no difference. justify why ii is technically acceptable to not use an EPR for the regional faults even though it was found to be technically Lines 397-404 required to do so for the Primary faults. If the sole justification is absence of hazard sensitivity, please review this passage and consider whether it be better focused on the one relevant issue. 464 Line 371 Please provide reference(s) to studies that demonstrate the absence of to Chapter 14 was added in dispositioning hazard sensitivity cited here. Lines 403-404 Comment 463. 465 Lines 384 Please clarify the sense in which the San Simeon event is less rrhis section was revised to better reflect our state of mechanically related to the Primary faults than the Landers rupture is to the Lines 417-420 knowledge about the relationship between the San Hector Mine faults. Simeon earthquake and faults around DCPP. 466 Lines 396-Please indicate whether the Tl Team judges that the EPR model captures rrhis section has been modified slightly and clarified to 399 epistemic uncertainty to accommodate the absence of a reliable '3xpress the Tl Team opinion that the EPR captures the model for how large events influence the likelihood of subsequent events. If Lines 432-434 uncertainty of time dependence. provide the justification for that judgment. If not, please explain where hat uncertainty is captured in the SSC model. 467 Line 403 is required between "Farther afield" and "EPRs" for clarity. Done Sentence deleted Lines 436-438 468 Line 408 Please explain precisely (either here or in the paragraph beginning on Line rrhe EPR values for the logic tree were not derived by a 1436) how the final values of EPR for the Hosgri and SLPB cases shown in precise formula. Rather. the values for the logic tree are rrable 11-4 were obtained from the various estimates in Tables 11-1 and intended to represent Table 11-1 without overstating the 11-2 (the corresponding calculation for SAF was explained in Section n/a precision available in the model for time dependence. 11.2.6). There is some explanation in the paragraph beginning on Line 436, but it is neither complete nor precise enough to enable the steps to be reproduced. 469 Line 427-429 rrhe intended meaning of this sentence is not clear. Please clarify. Reworded to better reflect how the EPR values were Lines491-498 selected. 470 Lines 430-rrhere should be some recognition of what this approach means in terms of We reworded the first two paragraphs under section 432 he alternatives that are included in the values that comprise the tables. For Lines 487-510 11.3.2 to better align with how values in tables 11-1, 11-2. what does this imply about relative defensibility of the recurrence 11-3 were summarized for the logic tree. model functional forms? COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 471 Line 432-435 Please explain in what respect the range accounts for the fact that the EPR original wording was an oblique approach to justifying may not fully characterize all contributory factors. The range in the tables is pur rounding the EPR values to a bit more than 1 !Wider than the range of the three branches. Isn't the range derived directly Lines 494-495 figure. The branch values in the logic tree are by discretizing the CDF obtained from the EPR analysis? intended as representative of the range, but are ""' lli<>ir --Tli<> ... 472 Line 438 Please clarify the meaning of "rounded across fault slip rate cases." Reworded. Lines 499-506 473 Line 455 Please clarify if this is seismic hazard. If so, the influence on hazard of any Rewritten to clarify, including some distinction that the given fault is a function not only of the effective (EPR-adjusted) slip rate, as EPR increases hazard relative to the fault to which it noted. but the distance of the fault from the site. So large changes in the Line 528 EPR for distant faults will result in small changes in the hazard. 474 Figure 11-3 bottom panel has the same title as the upper panel. even though it is a Fixed. k:listribution of times, not displacements. Please correct title. Figure 11-3 475 Figure 11-3 box title and in the figure headers indicate displacement per event, but Lower figure title and title block have been revised. in the text. you refer to these as average displacement. Please clarify if Figure 11-3 hese should be indicated as "average" displacements. both in the figure headers and box title. APPENDIX H-Method For Estimating Time Dependent Fault Hazard in the Absence of an Earthquake Recurrence Record 499 Line 45 "Poisson probability distribution of ground rupturing earthquakes" is Distribution of what? And, in fact, the Poisson distribution itself (probability of exactly n occurrences in a given time interval. as a function reworded bf n) is never used in the report. Please consider changing to a more Lines 47-48 precise statement (e.g., "the model of ground rupturing earthquakes as a Poisson process assumes that events occur randomly in time"). 500 Line 47 rrhis would be clearer if "to occur" is inserted between "more likely" and k:lone 'when the energy" Line 49 501 Lines 58-60 PSHA also initially did not consider the faults that gave rise to earthquakes; Rewritten to open the paragraph with this point. Historical seismic sources were source zones, each of which likely included reference for PSHA was distracting, and removed. faults. The point should be made early in this section that the whole Lines 59-60 ime-dependent recurrence concept is for fault-specific recurrence behavior. 502 Line 66 word "be" seems to be missing between "cannot" and "rigorously". Line 65 rt'es, fixed. 503 Lines 67-68 Consider indicating that an additional reason for the use of the Poisson Good, added. model is that regulatory design criteria are expressed as target annual *requencies of exceedance (e.g., 10-4) without consideration of any time Lines 66-69 ktependence. 504 Lines 70-71 But. as you discuss below. the use of an equivalent Poisson rate does NOT section has been rewritten and hopefully clearer. require a change in the hazard code. just inclusion of the concept in the SSC model. Please clarify. Lines 71-75 505 Line 97 *cumulative density function" is incorrect; please rewrite as "cumulative changed. k:listribution function." Line 99 COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 506 Line 162 phrase "before reaching the long-term mean" could be misinterpreted has been reworded. The asymptotic value depends o mean that the CP ratio is asymptotic to the long-term mean. which isn't Lines 148-150 pn the recurrence model width parameter. IJenerally the case. Please consider rephrasing to avoid ambiguity on this looint. 507 Lines 166-you saying that we have absolutely no idea what the value of these No, not the intent. Reworded. 167 parameters might be? Or that we have no direct data upon which to base Lines 151-153 hem. but they can be estimated with considerable uncertainty? 508 Line 180 phrase "although it coincides numerically with the data estimate of the Reworded along the lines suggested in the comment. more familiar coefficient of variation" seems unnecessarily cryptic. Since, in Lines 161-162 Matthews et al. (2002) prefer the term aperiodicity as a its role as a parameter in a PDF (Eqn 10), alpha is equal numerically to the more general description, and their paper defines BPT in CV, please clarify why it cannot simply be said to be the CV. use, so mention of aperiodicity is to respect ........... _ ............... L... .... --. * , 509 Lines 205-statement is not always true for faults having good paleoseismic data. sentence starts "Individual values for Dare not 206 Please qualify that this information is assumed to not be known for the Line 185 normally known,", and explains what we do when Dis not Faults in this exercise. known. 510 Line 210-211 'The distribution conveys a relative agnosticism among choices in Fixed in text. k!isplacement per event (OPE) from 1.5 meter to 3.5 .. Line 191 Figure EPR-3 shows DPE from 1.5 -3. 511 Line 213 Up to 5.0 m in the text of the report (line 258, page 14 of chapter 11 ). m was intended. Please check and rectify if different. Line 192 512 Lines 214-Please consider changing to the following (less fragmented) -Changed as recommended. 216 In California. for example, the largest measured average slips per event on he San Andreas fault are 4.45 and 4.3 m/event for the 1857 and 1906 Lines 194-196 respectively (Biasi et al., 2013). 513 Lines 218-22 reference to an upper bound of 5 m/event in the text appears to conflict Plots have been modified to end at ranges shown in the with values up to 5.5 m/event given by the solid curve in Figure 3 (there is a ext. The OPE is implemented as a list with non-zero break in slope at 5.5 min the plot, indicating a non-zero probability point at for the Hosgri from 0.5 to 5.5 in 0.5 m increments, hat value of sliplevent). Likewise. reference to an upper bound of 4 but the plot incorrectly implies weight above 5.5 m. The m/event in the text appears to conflict with values up to 4.5 mlevent for the Figure H-3 shape considerations affect plots of other OPE k1ashed curve in the plot. Please check and make any changes required for K:urves. K;onsistency. 514 Line 227 If L TM is displacement per event divided by fault slip rate, then L TM must L TM does have units of mean recurrence time. Text in be an inverse rupture rate (or mean recurrence time), not a rupture rate as Line 206 he affected area has been modified accordingly. Please check the text for consistency and correct as necessary. 515 Line 247 Please replace "to" with "do" Line 225 k!one 516 Line 265 If the reference to Philibosian et al. is the same article listed in the Revised to 2011. references section. then it should be cited as 2011 (rather than 2012). Please check and make a correction if necessary. Line 243 COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 517 Line 268 Since the EPR is a dimensionless ratio, not a rate, it would be clearer and rrhe EPR is a ratio, as noted by the reviewer. The text less subject to confusion to call it something else. Later the EPR is (and several figures) have been modified accordingly. from the distribution of **conditional probability ratio (CPR)", nla erminology that explicitly indicates the dimensionless character, so calling EPR a rate and CPR a ratio is a source of confusion. Please consider this point. 518 Line 275 Please replace "complimentary" with "complementary." fixed. Line 266 519 Line 283 is needed arter "renewal" to set off the first part of this sentence. Done 520 Line 284 rrhe "tl TM" appears to be a typo-please check whether this should be Fixed as suggested, and the word "small" removed 'LTM". because it conflicted with the direction of the sentence. 521 Line 286 It will cause confusion to say that the CPR is elevated relative to the Wording has been changed to distinguish between the Poisson rate. because the former is a dimensionless ratio and the later is ratio and the corresponding rate. lln absolute rate (events/unit time). Please rephrase this to be more precise. 522 Line 286 rrhe distinction between CPR and EPR is never stated explicitly, and this rrhe first paragraph under Estimating Equivalent Poisson confusion later on. The eventual impression is that CPR is treated Ratios" is largely new and dedicated to clarifying the lls a random variable and EPR its estimated value: if so. please consider relationship between CPR and EPR. The second making this explicit, and if not, please add text to clarify the paragraph covering Figure 5 has also been rewritten. mathematical/conceptual distinction between them. 523 Line 288 rrhe phrase "declines to approach the Poisson rate at the upper probable rrhis section has been reworded and the explanation range of tMRE" may be misleading. First of all, since EPR is a ratio, it approach unity if the CP approaches the Poisson probability? If please rephrase to make that clear. Secondly, the phrasing can be interpreted to imply that the approach to the Poisson rate is an asymptotic behavior. As that is in general not the case, please rewrite to avoid that impression. 524 Line 297 rrhe peak appears to occur below the diagonal in Figure 6, not above the Rewritten. ktiagonal as stated. Please add clarification or correct the statement or "igure as necessary. 525 Line 303 rrhe term joint probability surface" appears to be used here to denote a rrhe explanation of the joint probability surface used for 'oint probability density. However, this is not made explicit. and doubt is tvveighting has been extended and clarified. The fact that raised by Figure 7, in which it is obvious that the integral under the surface Figure 7 was normalized by its maximum value has been is much greater than 1, ruling out its interpretation as a joint PDF. Further in the text. arises from Equation 13, as discussed in a subsequent comment. Please be explicit and precise about what is meant by "joint probability 526 Line 303 rrhe joint probability appears to depend upon slip rate. If that is a correct Remarks on the relationship of slip rate to individual EPR interpretation. please indicate (in the text and caption) what slip rate was were added in a new paragraph inserted to used to generate the probability function in Figure 7, and confirm that that introduce the "Estimating Equivalent Poisson Ratios" rate plus the Hosgri OPE model of Figure 3 was the basis for the marginal distribution p(L TM) used to generate that figure (or if, that is incorrect. give the correct explanation). If the joint probability does not ktepend upon slip rate. please improve the description to make clear why not. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 527 Line 308 survivor function S(tMREIL TM) integrated over tMRE (for fixed L TM) is survivor function actually does have unit area, by not generally unity. p(L TM), being a PDF, does integrate to unity. So W k:;onstruction. This was obliquely the point of the sentence integrated over the tMRE,L TM plane is not generally unity. Therefore Wis in former lines 313-315. The discussion of weighting, not a joint probability density, yet the text gives the impression that it is '1rea of the S, and the mathematics have been rewritten. intended to be just that (though that interpretation is also cast in doubt by Figure 7, as noted in a previous comment). If W is something other than a oint PDF, please explain clearly what it is. If W is a joint PDF, but the reasoning in this comment to the contrary is incorrect. please clarify in the ext why there is no contradiction. Otherwise make necessary corrections that W can be properly considered to be a joint PDF. 528 Lines 313-15 sentence seems correct, but it is confusing because its intended Rewritten to move the point earlier in the paragraph. purpose is unclear. Is it simply intended to point out that the variates tMRE lln d LT M are not independent (because the factor S in Eqn 13 depends not ust on tMRE, but also on L TM). so that (by definition) the joint PDF is not the product of the marginal PDFs? Please rewrite or amplify to K::larify the intended meaning. 529 Line 320-321 horizonal axis in Figure 8 is labeled "Equivalent Poisson Rate" (and use of "Rate" has been revised to "Ratio". EPR is indicated in the caption), but the text seems to indicate that this axis represents the random variable CPR, not the estimated value EPR, and his interpretation is reinforced by the fact that the plot is presumably the GDF of a random variable (i.e., CPR). Please review and modify as necessary to make the text and Figure 8 consistent, and to make K::lear the conceptual distinction between CPR and EPR. The same K:;omment applies to Figure 9. 530 Line 320-321 apparently the curve in Figure 8 is a CDF (or the complement of Figure is slightly modified to clarify the location of the its maximum value should be 1. This is not clear in Figure 8. If in fact K:;urve as it approaches 1.0, and notes are added in figure he curve does rise rapidly to intersect 1 at zero CPR (and from looking at EXPLANATION box. Figure 9 it becomes clear that ii does), to avoid any confusion, please indicate that fact with a modification to the figure or a note in the caption 531 Line 335-336 Please explain the meaning of the vertical dashed lines in Figure 9. Description added. 532 Line 343 Please review the use of the term "marginal distribution" here. Wouldn't rrhe intended meaning is as the reviewer indicates, a delta marginalizing on IMRE mean integrating over it, whereas what is proposed on tMRE=t_eqk. Because the weighting is done is concentrating the tMRE dependence in a delta function delta(tMRE-pn narrow discrete values for tMRE, a single column _eqk) to begin with, so W=p(L TM) x delta(tMRE-t_eqk)? In what sense is it remains across the range of L TM. The reduction shares rue that "the equality constraint is a form of marginal distribution"? in common the idea of reducing a range on LTM-tMRE to on L TM alone, but it is not done by integrating, thus is not a true marginal distribution. The relevant L ... ,.. .. ....i;,,....,., a....,..,.. h,..,..,,... .. ,.. .. ,;,..,.....,i 533 Line 396 II is a little recursive to say that values of parameters used for Figure 12 was introduced by the author because of an were fixed to the values used in Figures 9-12. Please consider revising this incomplete editing of the draft. Back reference to Figures S-12 is removed and the sentence has been reworded COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 534 Line 407 Figure 13 has not been cited prior to this citation of Figure 14. Please check former Figure 14 (Weibull) has been moved to Figure whether the figure currently labeled 13 should be deleted and figures 13. A new Figure 14 is added that more directly l'.;urrently labeled 14 and 15 should be relabeled 13 and 14. If so, then the l'.;ompares the three time-dependent models. This at this point in the text should be Figure 13 (and subsequent figure is promised in Chapter 11 text. l'.:itations are already correct). 535 Line 426 would be useful between "principle" and "slip rate". Done 536 Line 456-457 Please explain the connection between the weighting method implemented rrhe maximum likelihood approach underlies our EPR here and a maximum likelihood perspective. because weighted solutions are extracted using joint L TM-tMRE probabilities. However, we reworded to replace the ML mention with a more important observation, that the action of the survivor to cut off right probability space leads to stability Pf the EPR estimate across recurrence model functional 537 Line 466-467 Please provide references for the cited MFD functional forms. Need truncated GR and WAACY refs. 538 Figure 5 Please correct the following deficiencies in the figure: 1. The caption is inadequate It should provide additional information. See comments on Figure set. including at least the CV used to generate the plots. the meaning of the circles in the upper right panel, and the meaning of the curve cutoffs K;B: redraw. in the lower panels. It should also properly indicate the nature of the are not all lognormal distributions, as the caption would even though they are all quantities derived from lognormal k:listributions. panels are called out by letter (e.g., "Figure 5d") in the text. but they llre not labeled with those letters. 539 Figure 7 Please indicate in the caption what slip rate was used to generate this See comments in Figure set. what OPE model was used ( Hosgri OPE model of Figure 3?), llnd what CV was assumed. 540 Figure 8 Please indicate in the caption the meaning of the red stars. See comments in Figure set 541 Figure 9 Please define the symbols, either in the legend or the caption or both, as See comments on Figure set wen as stating the meaning of the vertical dashed lines (which do not seem o be mentioned in the text either). Please also improve the figure title. tvvhich is rather cryptic (what does "Four Tmin,LN". mean. for example?). please review the use of EPR for the title and horizontal axis, and make changes as necessary to ensure consistency with the discussion in he text and with any intended distinction between EPR and CPR. 542 Figure 10 Please write a more complete caption for this figure. Is it based on the See comments on Figure set Hosgri OPE model? What are the dotted lines in the upper panel? Tmin is in the legend, but not clearly identified there, so it also should probably be given in the caption. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 543 Figure 12 Please improve the caption. At the least, the meaning of the colors should bkay. notes in file EPR_appendix be explained. Figures_with_notes.pdf. GB followup: redraw Weibull; olors backward. 544 Figure 13 rrhis figure may be redundant. Please check whether that is the case and Current Figure 13 to become Figure 14. It shows the BPT klelete if appropriate. results. The current Figure 14 shows Weibull. 545 Figure 14 Please check whether th is figure shou Id be relabeled "Figure 13". r-.'es, move this figure to become Figure 13. 546 Figure 15 Please check whether this figure should be relabeled "Figure 14" and write Figure 15 is correct after BPT figure is written in. informative caption (which should include deciphering "BWM"). For the caption, maybe the proposed text in the figure markup will do. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT PPRP COMMENTS AND Tl TEAM RESPONSES, CHAPTER 11, part b Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision Chapter 11-Time Dependency Model-Comments originally placed within Chapter 6 267 Lines Please consider rephrasing to the following -Key data from the DCPP Lines 49-50 Text modified as suggested 43-44 region are needed for fault slip rates and the lime since the most recent earthquake 269 Lines Please cross reference where hazard sensitivity studies show that the Line 62 Text added as suggested 53-55 SAF has only a small effect on hazard. 270 Line 62 Please provide a more specific reference (section number and figure Line 68 No change. Reference is to Lettis and Hall (1994) number(s)). 272 Line 63 Please show/reference lngley site on a figure. Line 69 Page reference in Lettis and Hall (1994) added 274 Lines It is recognized that the conclusions presented in these paragraphs Lines 66-96 Specific pages in primary references added 57-88 regarding recency, displacement per event, and recurrence intervals are summaries of the conclusions drawn elsewhere. However, the reader would benefit from specific references to the locations in the report andfor the primary references where the data have been evaluated and the conclusions and uncertainties have been developed 278 Lines Please flesh out this line of reasoning out-Lines 114-116 Text added per suggestion. 104-105 The founding of the mission at SLO in 1772 together with the lack of reported earthquakes in mission documents provides a rationale for settina Tmin=242 vr. 279 Line "Missions were sensitive to strong ground motions" Lines 118-125 Text editing and reviewed to make sure sentences 107 Please expand. following this one adequately support the statement. 280 Line Please consider rephrasing -Lines 130-132 Text modified per suggestion. 118-120 In summary, the lack of any damage reports in documents from the San Luis Obispo mission make it unlikely an earthquake of M6.5 or larger on DCPP Primary and Connected faults since 1772. 286 Line Please remove "is" Line 189 Typo corrected 185 288 Line Please remove wide" Line 211 Typo corrected 212 291 Line Please change displacement to displacements. Line 245 Text edited per suggestion 248 301 Line Figure 11-8 should be Figure 11-9. Line 382 Figure reference checked and updated to t 1-tO 350 COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 309 Line Consider replacing accidently with coincidentally. Line 412 Text modified as suggested 379 321 Line Please replace to with " do" Line 523 No change; text reviewed and to estimate" is correct. 453 COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT PPRP COMMENTS ANO Tl TEAM RESPONSES, CHAPTER 12 Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision CHAPTER 12-Regional Fault Sources 476 Lines 6-8 'Faults capable of producing moderate to large earthquakes that are not Lines 16-18 rrext revised as suggested. included as Regional fault sources are represented by the areal source (Chapter 13)." Please move to end of paragraph after line 13. 477 Line 13 In place of (or in addition to) the word small," please provide a quantitative Ines 11-13 rrext revised to cross reference to preliminary sensitivity of the relative hazard contribution from the regional faults. (Workshop 1.Appendix D) and Chapter 14 results. 478 Lines 28-29 Sounds like a sales pitch rather than an accurate technical statement. If the Lines 31-34 Reworded to be more measured. is "comprehensive" why does it omit many faults? What is meant by 'objective?" How can something be consistent with "all available data" when misfits are allowed to occur? Suggest toning down the description of UCERF3 to be more realistic and to specify that it provides a reasonable basis for characterizing some of the regional faults for the SSC model. 479 Line 34 Please consider citing an authoritative source such as a USGS report in Line 40 Petersen et al. 2014 (see their page 2) of the statement on this line. 480 Line 35 rrext moves back and forth between first person and third person. Suggest Lines 39, 51, 96, rr ext revised to use third person using third person throughout. 115, 119, 159. 181 481 Line 35 and (which implies changing them) or adopting (which does not imply Lines 39, 41 Changed; "adopting" was intended. Idea was preserved 37 hrough a rewrite to accommodate Comment 480. 482 Line 39 rrhe quotation marks suggest that this is a quotation from some source, or Lines 43-45 Puotes removed; the ordinary meaning of the word is hat the word itself, rather than its ordinary meaning, is the object of intended. interest. Please consider whether either of these is the case and edit (or not) accordingly. 483 Line 58 Please specify that this is an assessment made by the Tl Team. Line 62 rrext revised as suggested. 484 Lines 59-60 rrhe first clause of this sentence appears to have some sort of transcription Lines 62-66 Reworded and simplified. Please review and correct it. 485 Line 68 Where does this logic tree exist and who assigned the equal weights? Lines 70-71 Clarifications added. 486 Line 72 'Figure 12-5 shows ruptures common to both" Is the top panel of Figure Lines 74-75 Reworded The figure label is correct. the text has been 12-5 intended to include faults common to both UCERF3.1 and 3.2 The figure is copied from the UCERF3 main report, models? Presently, it is labeled Fault Model 3. 1. not accurately represented in the text. 487 Line 85 'the depiction in this SSC model, while FM3. 1 does not. Line 88 rt'es, done. Please consider deleting "depiction in this" 488 Line 95 Suggest deleting "radial." Line 98 Reworded. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 489 Line113 'come nearer closer to the DCPP than the physical SAF itself." Lines 114-116 Rewording allowed a shorter, clearer construction. Please consider rephrasing to -come closer to the DCPP than the SAF. 490 Line 117 Please replace we" with Tl team, if appropriate. Line 119 rr1 team 491 Line 216 Figure 12-4 indicates Queenie fault". Is there a difference? Figure 12-4 Figure revised to change labels to read Queenie, Purisima, and Lompoc structures to be consistent with ext. 492 Line 244 you suggesting juxtaposition of units of similar age that have Lines 260-261 rrhe text has been revised to be more consistent with different thicknesses? Please clarify. Otherwise, this could be in McCulloch et al. (1980). The concept of interpreted as growth strata. uxtaposition of units of similar age having significantly klifferent thicknesses is likely what the authors intended they cite this as evidence of significant lateral (rather than indicative of predominantly vertical bffset as evidenced by growth strata). However, in that the citation does not specifically state this, we are reluctant to explicitly make this assumption but would that this is implied 493 Lines 252-'Sorlien et al. (1999) note that the large amount of strike-slip inferred is No change No. Sorlien et al (1999) do not provide an estimate of slip. 253 based on a regional tectonic model, and they discount the large offset." rrheir interpretations of the data argue for predominantly klip slip (initially normal: later contractional) movement Do Sorlien et al. ( 1999) provide an estimate of slip? rather than major strike-slip. 494 Line 262 Please consider changing "overlapped" by onlapped or draped Line 280 rrext revised to use the term "onlapped". 495 Line 290 What is the type of magnitude indicating 7.0? Ms? Line 308 rrhe text has been modified to clarify that it is surface wave magnitude (Ms) 7.0. 496 Lines 301-It is understood that the characterization is simplified (i.e., single-valued). Lines 331-355 rr ext has been revised to provide additional justification 302 However, there is insufficient information in this section to understand how description of the simplified source characterization he values in Table 12-5 are derived. For example, the estimated slip rate used for the Non-UCERF3 regional fault sources. wor the Queenie structure is said to be 0.005 mm/yr in section 12.6.1.2, but Kl.1 mmlyr is shown in the table. The slip rates for the Santa Lucia Bank West Basin -Southwest Channel faults are listed here at 1 mm/yr. Earlier, you cite a rate of 0.2 mm/yr since the Pliocene forthe WB_SC fault, Which is likely a maximum as you state that much occurred toward the end the early Pliocene. Slip rates for other faults shown in the table are not kliscussed al all in the text. What approach was used? In the absence of wault-specific information. drawing analogies to other faults is appropriate. but must be indicated as such in the text. Likewise. what was the approach used to assess Mchar? It is not sufficient to merely indicate that sensitivity show these faults aren't important; that conclusion is dependent pn the characteristics that are ascribed to the faults. If one of the faults had rate of 30 mmlyr, the hazard significance might be different. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision 497 Figure 12-3 Consider a way to name the fault sources -not everyone will be familiar No change Faults within approximately 60 km of the site are labeled with the California fault system. pn Figure 12-6. More distant sources are not significant to he hazard at the DCPP. 498 Figure 12-7 What produces the sloping linear trends in seismicity rate between M6.5 No change to We put most of the explanation of the diagonal trend in M7.5. These are interesting and should be explained in a caption figure. Text he text, with a note of referral in the figure itself. The (which needs to be added to this and other figures). added 134-146 rends and the difference in rates between trends are k!iscussed in the text with the figure. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT PPRP COMMENTS AND Tl TEAM RESPONSES, CHAPTER 13 Location in Comment Location PPRP Comment Text for Summary of Revisions to Report Number in Text Comment Revision CHAPTER 13-Areal Source Zones 798 Line 1 Please consider adding some additional introductory information. such as Lines 3-6 Additional text provided as requested. the topics that will be covered in this chapter. 799 Line 2 Delete "of." Line 2 Modified to "away from" 800 Line 12 "but the faults are not sufficiently active to be considered" Consider Line 17 Added the phrase "well constrained" to the sentence. adding *'or well-constrained or studied" as there may be other faults of similar activity to the Shoreline fault that have simply not been identified or studied. 801 Line 17 It would be useful to acknowledge that, although it is recognized that Lines 22-30 Clarification is added on how distance adjustments are moderate-to-large earthquakes rupture finite lengths of faults. at large added to implement the point source characterization, as distances those ruptures can be approximated by ruptures effectively at a recommended. point for purposes of seismic hazard analysis. 802 Line 35 Add "smoothing" after Gaussian. Lines 67-68 The text is modified as recommended. 803 Lines Please give the units for the quantity 1 O" (e.g., is this an annualized rate Lines 72-73 Text has been modified to clarify the a-value is the log of 39-40 for M>O events?). the annualized rate of MO+ earthquakes. 804 Line 42 A factor of 0.1 would appear to be the correction factor for accounting for Lines 77-78 Text modified to more accurately describe the 0.184 the 0.1 magnitude increment, not the factor 0.184 cited on this line. The factor. latter would appear to account for the 0.1 factor multiplied by the additional factor 1.84, which equals bx log.(10), and accounts for the relationship between the exponential density function and the Gutenberg-Richter cumulative distribution. Please check whether this explanation is correct and make anv reauired chanaes in the text. Lines This leaves the reader wondering what the implications are for the n/a Discussion of 2014 model is removed as it is not used. 43-46 research coming out afterthe model was locked down. Please explain how this is relevant -did you use it or not? If so, then consider deleting this sentence, as it is irrelevant. If not, then close with a statement of what was and was not used. As it is, there is no final context to understand the meanina of this sentence. 806 Line 52 Replace "we make" with "the Tl Team makes." n/a Sentence was removed 807 Line 57-This sentence as written seems to say that the given latitude/longitude Lines 182-183 The sentence has been rearranged to clarify that the 59 range is that part of the Regional ASZ that extends beyond the 320 km Regional areal source zone extends beyond the 320 km limits, whereas Figure 13-1 makes it clear that the given latitude/longitude limit. Please note that the sentence has been moved range actually defines the full Regional ASZ (and this full range happens down into the section on the regional source zone to extend beyond the 320 km limits). Please rewrite to clarify the meanina. 808 Line 64 The concept of a "DCPP Site Vicinity" seems to be important enough to Lines 11-13 A definition of Site Vicinity has been added to Section be named and capitalized. yet has not been defined up to this point in t3. t Chapter 13. From Figure 13-t, it seems to be defined by a 40 km radius circle centered at DCPP. but this has not been made explicit. Please make sure this term has been defined prior to its use, and also be consistent with caoitalization re.a., note that the term is caoitalized in the COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision text. but not in the figure legend). 809 Lines II is not clear at this point why two catalogs are being considered, how the Sections The chapter has been reorganized to clarify the purpose 67-68 comparisons with the predicted rate will be done, or what "adjustments to 13.2.1. 13.2.2 of considering catalogs, and a reference has been the baseline gridded seismicity rates" means. Please provide more added to the section where adjustments are assessed. explanation and context. What type of "adjustments" would be made if there are differences? Or reference other parts of the report where these issue are discussed. 810 Line 74 It would help the reader to also indicate that those two catalogs are n/a A reference to the section in which the catalog seismicity discussed below. rates are compared to the gridded seismicity rates is added to the preceding paragraph. and this line is deleted. 811 Line 75 Considered for what? Remind the reader what the catalogs are being Sections The chapter has been reorganized to clarify the purpose considered for and how they will be used. 13.2.1. 13.2.2 of considering catalogs, and a reference has been added to the section where adjustments are assessed. 812 Line 88 This would read more clearly if "the" was placed before "Felzer" Lines 144-145 Term changed to. updated UCERF3 catalog" throughout text and figures. 813 Line 88 This is a methodology section, but it would help the reader if a pointer was Lines 98-99 Reference has been added to Section 13.4 directing the made to the section where the conclusions from exercising the reader to the section where adjustments are assessed methodoloav for the Vicinitv sources are aiven. and the conclusions are drawn. 814 Line Again. a pointer to where the Local sources are described would be Line 109 Reference has been added to Section 13.5. 106 useful. 815 Line Please be specific about what quantity is plotted in Figure 13-2 (e.g., is it Line 75; The values shown on this figure (which is now 13-6) and 117 the annual rate of events in a 0.1 magnitude-unit wide bin centered on Figures 13-6 Figure 13-7 are the gridded seismicity rates. These may MO, per 0.1 x 0.1 dearee soatial bin?J. and 13-7 be converted to a-values using Equation 13-2. 816 Lines Please provide further technical support for the 70%-30% distribution Lines 198-200 References to the hazard sensitivity analyses that show 124-125 (e.g., is it consistent with focal mechanism distributions where those data and 94-97 that the regional areal source does not contribute are available?), or reference sensitivity studies or other evidence that significantly to hazard have been added. indicate that the effect of this distribution is not hazard significant. 817 Line Please consider replacing second "and" in the sentence with *'as well as Line 218 Text modified as recommended 142 818 Line Agreed that it is a less clear association. but Edna and the western portion Lines 225-229 Although there may microseismicity associated with the 149 of the Los Osos show some spatial association with microseismicity -northwest-trending part of the offshore Los Osos fault, in please consider softening by using "less clear association" -rather than our evaluation of seismicity data within the Irish Hills we "no clear association" find no clear association of seismicity with the Edna or Los Osos fault. The text has been revised accordingly. A reference to the discussion of microseismicity in section 13.5.2 and 13.5.3 is added. 819 Line Please consider "higher density" as a replacement for (the slightly Line 233 Text revised as recommended. 154 awkward) "qualitative(ly) greater number" 820 Line This table needs a caption explaining each of the Table elements. Also. Table 13-2, Table is clarified. Scale factor is defined in the opening 189, the implied scale factor is not clearly explained. Lines 247-250 paragraph of section 13.4.2 Table 13-2 821 Line Consider replacing that" with "as to which" for clarity Lines 282-289 Paragraph modified; sentence omitted 207 COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision 822 Line Please state why this 3-point distribution is an adequate representation of Lines 290-300 Revised paragraph provides basis for 3-pt distribution 209-211 the CBR of the TDI. capturing uncertainty. 823 Line Consider changing to a greater extent" Lines 307-308 Text modified as requested. 218 824 Lines Consider breaking up this very long sentence, for clarity. Line 305-312 Text modified as requested 215-223 825 Line "study" should be plural. n/a The chapter has been reorganized and this sentence is 247 deleted 826 Line Please define what is meant by virtual faults, or indicate in the text that Lines 33-35 The concept of virtual faults is described in the revised 248 this term is used in a sense that will be explained later in the chapter. introductory section. 827 Line Please define what is meant by "semi-randomly." or indicate in the text n/a This term is no longer used to describe the spacing of 250 that this term is used in a sense that will be explained later in the chapter, virtual faults. if that is the case. 828 Line Need an introductory sentence that states what this section is about. Lines 332-337 In lieu of an introductory sentence here, we amended 254 the end of the introductory paragraph (Section 13. 5) to provide a *'road map" of the section. 829 Lines Consider using a, b c, etc ratherthan #, x, and y for the 2014 PG&E Line 596 and PG&E (2014) is the CCSIP report, which contains 12 257 and citations. Also. there are 8 PG&E 2014# citations listed in the references Numerous chapters. This chapter has been revised to refer to each numero section. Please rename them all so the reader knows which citation locations CCSIP report chapter independently. which is consistent us other refers to which reference. throughout the with the remainder of the Diablo Canyon SSC report. location text s 830 Line Replace "was" with "were." Line 619 Text modified as requested. 282 831 Line The word inference is pretty weak. How about, "it can reasonably be Line 622 Yes. Text modified to read .... .first-order conclusion 285 concluded"? that... " 832 Line Figure 13-6 should be 13-5. Line 642 Figure references updated to the current figure numbers. 304 833 Line To the extent possible, it would be preferable to replace references to Line 652 The Tl Team has made a point of referring to 315 workshop presentations by references to published reports or papers. For presentations made at the Diablo Canyon SSHAC example, please consider whether the pertinent part of McLaren's workshops to emphasize that we are following the powerpoint presentation could be covered by references to Mclaren & SSHAC process. The presentations are made available Savage (2001) and to the 2011 PG&E Shoreline Fault report. Please to the public, and a website address where the check on the viability of similar substitutions for the other workshop presentation can be found is included with the title of powerpoint presentations cited in this paragraph. each presentation in the reference section. 834 Lines Consider breaking this long sentence into a couple of parts to assist the Lines 665-671 Text modified as recommended. 327-332 reader. 835 Line This sentence would read more clearly if "is more problematic" was placed No change This rearrangement is not adopted. We consider 332 after "Local Source Zone" in line 331 splitting the sentence (as recommended in comment 834 l to be sufficient clarification. 836 Line Please state the basis for the Tl Team judgment that the method and Lines 681-698 Text modified to provide support of this judgment. 341 results are unreliable for identifying laterally continuous fault sources in this context. 837 Line The dips might be consistent; however, the OADC-FM fault plane Lines 684-689 Uncertainly in the directions of dip associated with the 346 solutions dip in the opposite direction lo the dips in the NE and SW OADC-FM solutions is addressed in the new. more vergent models as well as dips interpreted from seismic and well data in thorough discussion of these results. the CCCSIP. Please clarifv. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision 838 Line "Map" should be plural. Line 712 Text modified as recommended. 348 839 Line Please consider deleting "compiled from that effort Line 715 Text modified as recommended. 351 840 Line Insert "shown" (i.e., "is shown on"). Line 723 Sentence rearranged to address this issue. 359 841 Lines Might consider rephrasing -The Tl Team judged that the quality of the Lines 733-736 Text modified as recommended. 365-367 seismic reflection data used to delineate the faults was poor and introduced much uncertainty in mapping fault dip and architecture, a concern expressed bv the authors (PG&E, 2014#, Chapter 7). 842 Lines Also might want to mention that even though the interpretations are Line 739 A note is added that the cross section is consistent with 371-374 uncertain they are constrained/consistent with well data in the region. surface geologic and well data. 843 Line "within the" is repeated -please delete one. Line 749 Text modified as recommended. 384 844 Lines Please explain why the existence of a residual uncertainty as to the Lines 752-754 Text is modified to clearly present the rationale for the 389-392 amount of strike-slip deformation present would justify assigning strike slip aleatory variability in the model (and avoid mixing a higher frequency of occurrence relative to the reverse style (i.e., if I have epistemic uncertainty). a C average on half the class assignments, and don't turn in the other half. there is residual uncertainty about how many A's I would have qotten, but this mav not iustifv raising mv grade to a Bl. 845 Line Remove hyphen in half-way; also please check hyphens throughout text Line 762 Hyphens were checked throughout the report by the 396 (e.g .. line 389. well constrained needs a hyphen). technical editor. This one was removed as part of that process. 846 Line Note typo: "Where" should be lower case. n/a This sentence was removed as an alternative approach 421 to the assessment of rates for the Local areal source zone was used (Section 13.5.1) 847 Line As noted in a previous comment, the factor 0.184 appears to account for Lines 76-78 This factor is described in Section 13.2.1 421 both the magnitude increment and the transformation from the incremental to the cumulative magnitude-frequency relationship. Please check and make appropriate changes in the text. 848 Line Table 13-3 has NE and SW dips for both strike slip and reverse -the logic Figure 13-19 Figure is modified for consistency. Please note that the 452 tree in Figure 13-14 has N or NE and Sand SW for reverse faults -logic tree is now shown on Figure 13-19 please make consistent. 849 Line Please add at this point in the text that "slip rates for the virtual faults" in Lines 826-827 Text modified as recommended. 457 this context will mean the sum of slip rates across all the virtual faults. Currently this is a point of confusion until it is finally explained on Line 491-493 and in the footnote to Table 13-5. 850 Line Might want to add some supporting information as to why less than about Line 836 This sentence has been deleted. 466 4. 851 Line Please check whether Mo on the left side of Equation 13-5 should actually Line 840 A definition of M0.;has been added 472 be Mn.;. If so. please correct. and if not, please explain what Mo.1 means on the right side of Equation 13-6. 852 Lines The s" needs a dot above it to indicate that it is slip rate. Otherwise, this Line 851 Modified as recommended. 479 and equation will be mistaken for the equation for Mo. Use of "s" for slip is 480 standard notation, so using it without the dot for slip rate will be confusing 853 Line Please check and correct this rate. which should probably be "0.07 Line 890 Modified as recommended. 505 mm/yr." COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision 854 Figure Using colors in the explanation is a little problematic as they don't match Figure 13-1 The colors were selected to be readily distinguishable 13-1 the colors in the figure in a consistent way due to overlapping color with from each other. some transparency. For instance, the regional source zone has a different color onshore versus offshore. 855 Figure Please give the units for the rates shown in the legend (e.g .. indicate that Figure 13-6 Please note that the figure has been renumbered as 13-13-2 they are annual rates if that is the case), and be specific (in the text or a 6. The colors shown here are the seismicity rates. They caption or note on the figure) about what quantity is plotted. E.g., does it can be related to a-values using Equation 13-2, as represent the annual rate of events in a 0.1 magnitude-unit wide bin described in Lines 75-78. containing Magnitude 0, as estimated by 0.184 x 1 o* (where a is the annual rate of events of M>O) as Line 42 seems to indicate? We did not add faults to the figure to avoid distracting readers from the main point of the figure. Consider adding the major faults to this figure -would clearly show that the nearest red areas are associated with the San Andreas fault. 856 Figures In the Explanation", where is spelled "wehere" and buried is spelled Figures 13-2, These and other spelling errors were corrected. Please 13-3. -"burried". Please correct the spelling in all such figures. as the error is 13-3, and 13-4 note that the figures have been renumbered. 4, -5 reoeated. 857 Figure Observe 2 colors for the 0.1' grid; however only one color (yellow) shown Figure 13-7 The variations in yellow shown on the 0. 1 Vicinity areal 13-6 in legend source zone grid are due to overlaying the grid scale onto the project basemap, which includes grayscale colors onshore and blue offshore. We find ii useful to consistently use the same project base map for the report, and consider that readers will be able to recognize that the shades of yellow are all meant to represent the same rate (shown in the explanation). Please note the figure has been renumbered as 13-7. 858 Figure Notes state "Figure modified by Hardebeck, 2012; Legend states "From Figure 13-13 Conflicting references have been clarified. 13-8 Hardebeck, 2011" If the distinction is intentional and necessary. please Please note that this figure has been renumbered as 13-add some clarification. If both references are to the same content, please 13. make consistent. 859 Figure The figure has PE as a site. whereas the Abbreviations: lists it as PB for Figure 13-14 Figure has been corrected. 13-9 Point Estero. Please correct the abbreviations to PE so that they are Please note that this figure has been renumbered as 13-consistent. 14. 860 Figure Cites PG&E (2014). Is this 2014x, 2014y or 2014#??? Figure 13-16 The citation has been corrected to PG&E (2014, Chapter 13-11 7). Please note that this figure has been renumbered as 13-16 861 Figure No apparent dip symbols appear to be used in the figure. Either make Figure 13-17 There are numerous apparent dip symbols shown above 13-12 these larger/clearer or delete reference to them in the "Geologic Symbols" the ground surface on the figure. They are already fairly explanation. crowded, and making them larger would cause them to block one another. Please note that this figure has been renumbered as 13-17. 862 Figure Is it reasonable to have virtual faults that cross the Hosgri fault zone? Figure 13-18 The virtual faults are shown on the figure to illustrate 13-13 their geometry and spatial distribution relative to the DCPP. The parts that extend across the Hosgri fault zone do not affect hazard at the DCPP. Because there is not enough information to characterize these as fault sources, the Tl Team considered it appropriate to characterize all the virtual faults the same wav, instead COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision of attempting to distinguish differences in length and Mmax for different parts of the zone. Please note that this figure has been renumbered as 13-18. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT PPRP COMMENTS AND Tl TEAM RESPONSES, CHAPTER 14 Location in Comment Location PPRP Comment Textfor Summary of Revisions to Report Number in Text Comment Revision CHAPTER 14-Hazard Sensitivity 925 General comment: at several locations, only a discussion is given of what Additional text is provided, as appropriate, recognizing the sensitivity analyses show. More discussion is needed of 'tlbY these that the scope of this report is to document the SSC results occur, particularly as related to the particular elements of the SSC model and not to document or defend the final PSHA model. Otherwise. the reader is left to ponder and. given the various results. assumptions that were used to construct the sensitivity cases, may question whether the result is credible. 926 General comment: Figure captions (or "notes" for the PG&E template) are Figures have been improved for clarity. very much needed for this chapter. Without them, the reader is forced to Hip back and forth between the figure and the text in order to gain an understanding of the important messages being portrayed. The captions should draw the basic conclusions-or "take-aways"-for each figure. 927 Lines It is suggested that this sentence be the topic sentence for the chapter. Lines 1-3 Revision accepted 68-71 928 Line 81 Consider putting the sentence from Lines 109-111 at the end of this Lines 19-21 Revision accepted section. 929 Line 95 Please replace "was" with "were". Line 37 Revision accepted 930 Line 99 It is suggested that a description be given of what the tornado plots show Lines 41-43 Additional clarification provided (relative contributions to hazard uncertainty) and why they are called tornado plots (largest contributors to uncertainty are placed at the top of the diagram) 931 Lines The explanation of the construction of the tornado plots is given more Lines 52-55 The cases that are specifically commented on are for 101-103 precisely and clearly here than has been customary (thanks!). But a values not in the logic tree. In these cases. the corollary of the description (specifically, of the normalization) seems to be sensitivity analysis assumes the full 100% weight on the that the values on a given line of a tornado plot (weighted by their branch test case. The tornado ratio value provided to shows weights) should sum to unity. Visually, that appears to be at least roughly what the impact would be on the total hazard if the test true in most cases. Bui there are exceptions, e.g .. "IHEB Areal" in Figures case was used instead of the logic tree values. The text 14-7, 14-8. "synchronous GM" in Figure 14-9. 14-10, "full characteristic" in is clarified to state that both types of sensitivity analyses Figures 14-11. 14-12. "magnitude PDF in Figure 14-12. If this is a are presented on the tornado plots. (See further misunderstanding, please clarify (e.g., perhaps it is mistaken to identify explanation in next comment). each line of a tornado plot with a node of the logic tree?). If this is correct, please refine the explanation of the tornado plots to accommodate the aooarent exceotions to the current definition. 932 Lines What are the "some cases" and please explain why they provide a value Lines 52-55 See previous comment response. Cases not shown in 107-108 that is not in the logic tree. the logic tree, for example, include the use of gridded seismicity for the local areal source zone rat her than virtual faults (which IS in the logic tree), and using only the YC characteristic model for maximum sources. This type of analysis is performed for a variety of reasons, such as to support simplification of the SSC model. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT 933 Lines Does this mean that the conclusion drawn from the sensitivity analyses Lines 19-23 Additional clarification provided. 110-111 are also "not representative"? Perhaps it would be more accurate to say that the levels or amplitudes of ground motions may not be indicative of the final hazard results that are based on the inclusion of the full SWUS GMC model. 934 Line The figures and text refer variously to "annual frequency of exceedance Line 49 and The figures have been edited and updated. 119 (AFE), annual exceedance probability (AEP), and annual exceedance of elsewhere probability." Please make them consistent throughout figures and text. 935 Line There is actually a visible difference in hazard in Figure 14-1a at AFEs Lines 61-69 Although as noted there is a difference in the hazard 121. greater than 10-4. Is there a reason that it is not noted here? If it is not curves for AEPs of 10-4 and greater, the primary focus Figure significant, please so state. for this study is for AEPs in the range of 10** to 10*6* 14-1a 936 Line Please discuss the reasons for the differences in hazard level between Line 66 and Although we do not want to speculate in the text, the 125 the 2015 SSC and 2011 Shoreline models. In particular. why has hazard Figure 14-1 difference in hazard results for low frequency (long dropped systematically for the low ground motion levels. and increased period) motion may result from an increase in systematically (at least in the 05 Hz case) at high ground motion levels? magnitudes considered for the Hosgri fault in the 2015 SSC model relative to the 2011 model. For higher frequencies, the smaller magnitude earthquakes tend to contribute relatively more to the total hazard than the larger magnitude events. Given the location and magnitude distribution of the Local areal source zone, this leads to a relatively larger contribution of this source to the total hazard for the 5 Hz versus 0.5 Hz cases. We prefer that the text focus on documentation of the SSC model and not on discussion of the hazard results 937 Lines It might help the reader by stating something like For example, as shown Lines 77-83 Additional clarification provided. 133-136 in Figure 14-1a. the mean AEP associated with at 5 Hz spectral acceleration of 1 g is about 10-3. 938 Line Replace "past" with "previous" Line 99 Revision accepted 154 939 Line An explanation for the contribution at higher frequencies made by the No change to Once again, we prefer that the text focus on 158 IHEB source zone would be helpful to the reader. text documentation of the SSC model and not on discussion of the hazard results. As stated above, for higher frequencies, the smaller magnitude earthquakes tend to contribute relatively more to the total hazard than the larger magnitude events. Given the location and magnitude distribution of the Local areal source, this leads to a relatively larger contribution of this source to the total hazard for the 5 Hz versus 0.5 Hz cases. 940 Line Please compare the relative hazard from the Local areal source zone with No change to We prefer that the text focus on documentation of the 163-165 the corresponding result from the 2011 Shoreline model and discuss text SSC model and not on discussion of the PSHA results possible explanations for any differences. 941 Lines Any explanation why the SA contributes at the lower ground motions? It is Lines 111-113 We agree. The larger earthquakes at greater distance 165-167 likely related to the relatively high rate of occurrence of large earthquakes on the SA contribute at lower frequency (0.5 Hz) but not on the SA. but the great distance lowers the likelihood of larger ground at higher frequency (5 Hz) motions. 942 Lines Consider noting that such an observation is not unusual for site-specific Lines 126-131 Additional clarification is provided. 182-185 hazard results. 943 Line Please make reference to the specific section of the report that describes Line 134 Section 9.3 describes the allocation of fault slip rate to 188 these logic tree branches and weights. rupture sources. and presents the logic tree branches and weights. Reference has been added to the text. The discussion of slip rate for each fault is given in Chapter COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT 8. 944 Line Please explain why this simplifying assumption is made (these are the Lines 136-139 Yes. Additional clarification is provided. 192 highest weighted FGMs?) 945 Line Please explain why these AEPs are used for the display. Line 147 and These AEPs are used because this is the AEP range of 200 Lines 64-65 interest for nuclear sites. The introduction to Section 14.2 is corrected to reflect this. 946 Lines The weights on Line 231 give the appearance of being rounded No change to The weights shown on line 205 are for slip rate; the 205 and representations of the weights on Line 205. If this is so. please clarify why text weights shown on line 231 are for FGM. They are not 231 one case was rounded and the other not. And, in any event, please clarify rounded from one another. When weights are assigned why the weights on Line 205 are expressed to such high precision while by judgment, they are typically given to the nearest those on 231 are not. tenth; when weights are assigned from a three-point sample of a continuous distribution using Keefer and Bodily ( 1983 l, they are shown with qreater precision. 947 Line Replace "as" with "and" Line 161 Revision accepted. 214 948 Lines Please discuss the factors which may account for the stated differences in No change to Although we do not want to speculate in the text. the 222-225 hazard from the three FGMs. text difference in hazard results may relate to hanging wall effects associated with the more gently dipping faults in the SW and NE models relative to the OV Model. 949 Line Replace "unit" with "unity." Line 174 Revision accepted 224 950 Line Figure 14-8. Please provide figure captions and spell out abbreviations. Figure 14.8 Figures have been improved for clarity. 227 Would be helpful if figures and figure captions were self explanatory. and others 951 Line Replace "done" with "performed" Lines 188 and Revision accepted 238 and 190 240 952 Line This is not the "standard" for host zones any longer (e.g .. CEUS SSC Lines 189 Revision accepted. 239 model, Hanford PSHA. BC Hydro, etc.). Suggest deleting "in a more standard way". 953 Lines One might have speculated that smaller dip would decrease the average No change to We prefer that the text focus on documentation of the 252-259 Rjb distance of DCPP from the virtual faults, and thereby would affect text SSC model and not on discussion of the hazard results. hazard measurably. Please consider whether some simple explanation Although the change in dip angle and associated can be provided for why this is not what is seen in the sensitivity analysis. hanging wall and RJB distances would have an impact on the contribution from the Local areal source individually, its relative contribution to the total hazard reduces the impact on the total ground motion change as shown in the tornado results. 954 Line The section heading, figure captions, and most of the text. describe this Line 209 It could be separated but this would lead to a single plot 260 as a section on time dependency. But the complex and splay mechanism for just the splay/complex case. Section heading is (general sensitivities are tucked away in this section too. Anyone scanning the revised to add Complex and Splay rupture sensitivity for com me chapter or figures for the latter sensitivities will likely not find them. Please transparency. nt on consider making the full purpose of the section and its figures more section transparent. 14.2.61 955 Lines This is not necessarily expected." The contribution to hazard uncertainty Line 214 Text revised to delete "as expected". 265-266 that the EPR branches make could be small if the range of EPR values was small-despite the dominant contribution of the Hosgri fault to the hazard. In other words. the large contribution of the Hosgri fault to the hazard means that the details of the characterization of that source are generally more important than other sources. But that does not mean that any given characteristic of that source will contribute significantly to the hazard. The EPR is one that does. COMMENT-RESPONSE LOG DIAB LO CANYON SSC STUDY DRAFT REPORT 956 Lines The sensitivity to Hosgri EPR appears to be significantly higher for 0.5 Hz No change to We prefer that the text focus on documentation of the 265-269 than for 5.0 Hz. If this is a correct understanding, please comment on it text SSC model and not on discussion of the hazard results. and if possible suggest an explanation. The percent contribution of the Hosgri fault at both AEPs is slightly greater for 0.5 Hz relative to the 5 Hz case, which leads to a larger range in the tornado results. This may be due to the larger magnitudes characterized for the Hosgri fault than for other sources. For lower frequencies, the larger magnitude earthquakes tend to contribute relatively more to the total hazard than the smaller magnitude events. 957 Lines Interesting, in that the SAF is known to be at or near the end of the Lines 214-215 Relative contribution of the SAF to the total hazard is low 269-272 seismic cycle -why doesn't this have more of an effect? compared to the other sources shown here, so changes to this individual hazard curve do not significantly chanoe the total around motion values. 958 Lines Consider adding the phrase to the end of the sentence "'due to the lack of Lines 231-232 Additional clarification is provided. 282-283 including the secondary (or splay) rupture event." 959 Lines Please discuss this a little further. Does this reflect that those ruptures are Lines 234-236 We prefer that the text focus on documentation of the 285-287 very infrequent in the model and therefore contribute very little to hazard SSC model and not on discussion of the hazard results. to begin with? Or does it reflect the dominance of the primary rupture, This result very likely reflects the infrequency of these such that the SSRS is little affected by the secondary rupture? Or both? ruptures in the model 960 Lines More accurately, the inclusion of the complex (or splay) ruptures or not Lines 234-236 These results show the impact on how the 286-287 does not have a significant contribution to the uncertainty in the total splay/complex sources are modeled in terms of their hazard. ground motion compared to ground motions that would result from modeling just the primary (or main) rupture. The text has been modified to reflect this. 961 Line Replace "unit" with "unity" Line 254 Revision accepted 303 962 Lines Please provide an explanation for why this is the case. Lines 263-266 We prefer that the text focus on documentation of the 312-316 SSC model and not on discussion of the hazard result. For 10*6 at 0.5 Hz, the characteristic earthquake magnitude PDF may be lower because of a lack of rare large events that are contained in the WAACY model. For lower frequencies, the larger magnitude earthquakes tend to contribute relatively more to the total hazard than the smaller maonitude events. 963 Lines Please provide an explanation for why this is the result. Lines 282-284 We prefer that the text focus on documentation of the 331-335 SSC model and not on discussion of the hazard result This result suggests that the relatively rare large events represented by the high M * .,, alternative contribute to hazard uncertainty at very low AEP (i.e., 10*6) and low freouency (0.5 Hzl. 964 Line Should *'plots" be singular? Line 293 Text has been clarified 343 965 Lines This explanation needs bolstering. Is it only the proximity of the Hosgri Lines 300-305 Text has been clarified/bolstered 353-354 fault to the site? Both the slip rate and the EPR are directly tied to the recurrence rate, is that why they contribute most to the uncertainty in hazard? The Hosgri fault's slip rate is 1-2 orders of magnitude greater than any other nearby fault AND it is close to the site. Why not spell out why this result is expected, as this is the concludino punch of the chapter. December 14, 2014 Mr. Kent S. Ferre Project Manager Pacific Gas & Electric Company 245 Market St. San Francisco, CA 94177

SUBJECT:

Participatory Peer Review Panel Letter No. 1: DCPP SSC SSHAC Project Draft Report Installment #1

Dear Mr. Ferre,

This letter provides in writing the comments of the Participatory Peer Review Panel (PPRP) on the Diablo Canyon Seismic Source Characterization (SSC) SSHAC Project Draft Report. We (Coppersmith, Day, Rockwell, and Driscoll), the designated PPRP, want to express our appreciation for the opportunity to review Installment #1 of the Draft Report, which consists of Chapters 1 -5, and 8. Our review comments are provided in the attached table and each comment is associated with a unique number. We will consecutively number our comments in future transmittals for clarity. The table includes a column for the Tl Team to summarize the revisions made to the report to respond to each comment. We would request that a completed copy of the table be returned to us with the revised report to expedite our follow-up review. We look forward to answering any questions of clarification regarding these comments during our conference call on Wednesday, December 17, 2014. Sincerely, DCPP SSC PPRP K. Coppersmith, Chair S. Day N. Driscoll T. Rockwell ATIACHMENT PPRP COMMENTS ON DCPP SSC DRAFT REPORT INSTALLMENT #1 Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report General Comments The report is generally well written and comprehensive. The entire text would benefit from a thorough technical edit. This edit would ensure the consistent use of tense throughout the text, maintain the consistent use of the third person, ensure the 1 consistent use of terminology, remove redundancies from section to section, and correct typographic errors. We have not attempted to provide such a technical edit in this review but have focused on technical justification and clarity. In some cases, where errors are obvious to us, we have noted those. In several instances, the absence of figure captions detracts from the usefulness of the figures. Figure titles are important, but they do not provide the link from the image to the technical arguments being made in the text. We strongly urge that figure captions be developed for all of the figures that provide a summary of the salient elements of the figures that are being presented, and the key technical conclusions that the authors 2 would like to portray. The fundamental technical arguments and detail will still reside in the main text, but the figures will carry additional meaning when they are accompanied by captions that highlight those arguments. Further, the captions will provide an opportunity for the various panels of a figure to be defined and discussed, without forcing the reader to flip back and forth between the main text discussions and the figure. Figure captioning of the type requested is standard for a report of this kind. We recognize that the SSHAC process allows for the 3 consideration by the Tl Team of all data, models, and methods that exist within the larger technical community, including those 1 Unless otherwise indicated, paragraphs identified are for the section, rather than on the page cited. Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report that have been developed within a QA environment, the peer-reviewed literature, unpublished reports, or otherwise. A vitally important part of the documentation process is the attribution of those data, models, and methods by exhaustive referencing throughout the report. Thus, many of our comments call for more complete referencing of the technical conclusions and assertions made in the text. It is particularly important to indicate which technical assessments have been taken from other sources (with proper referencing) and which have come from the Tl Team itself. In the hierarchy of sources of information, we consider personal communications to be the least defensible, due to the general inability of the report reader to verify their accuracy. We therefore urge the authors to avoid reference to personal communications if at all possible. If any cited source can be made (e.g., reference to abstracts for presentations at professional conferences, reference to presentations made at the workshops and documented in the workshop summaries, papers that have been accepted for publication but not yet published), that would be preferable to a personal communication. If there is no other reference to cite, please consider whether the technical conclusion being made is vital to the SSC model and whether it can be removed from the report. If the conclusion is vital and a personal communication is the only source of information, please consider adding documentation to the report in the form of an aooendix. We recognize the need to develop the report in installments in order to meet the project schedules; however, this precludes our ability at this stage to provide intelligent comments on the accuracy of cross-references. We urge the authors to provide the most specific cross-referencing possible to assist the reader in understanding the technical arguments being made. For 4 example, given the scale of this report and the complexity of the technical issues, cross-referencing is essential to guide the reader in seeing how the evaluation of data has led to the development of the SSC model. As the arguments are developed, links within the text will be needed to refer to the specific sections and subsections of the report where the information lies. Simple reference to an entire chapter is not Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report helpful, but reference to specific subsections will be most useful. Hence. once all sections have been written, it is strongly recommended that a single author read through and edit the document with the appropriate detailed cross-references. Reviewing a report in installments is not ideal but required in this case. Without seeing how the sections in this installment interface with other sections, there is a certain amount of faith that we must have that the technical data and arguments made 5 in other sections will support the positions taken in this installment. Although the comments made in this round of PPRP review provide a comprehensive review at this point in time, we reserve the right to provide additional commentary on the sections of Installment #1 in the future after we have reviewed later sections of the report. Chapter 1 6 Section 1.0, p. 17, 1st Suggest adding " ... ground motion at the site as a function ... " paragraph, last sentence 7 Section 1.0, p. 17, 1st Please specify if this SSC report will also be an attachment to paragraph, 4th sentence PG&E 2015. 8 Section 1.0, page 17, 2nd Will PG&E documents (e.g., 2015 and others referred to in text) paragraph 7th line down be accessible on PG&E/LCI share drive? 9 Section 1, Page 17, ." ... was conducted from June 2011 to January 2015. Please Paragraph 2, line 8 change to February 2015, as this date is more realistic. 10 Section 1, Page 17, Please include the specific date of the kick-off meeting. Paragraph 2, line 9 11 Section 1.0, p. 17, 2nd 35 working meetings are identified on page 28 and Table 3-1. paragraph, line 10 Please clarify. Section 1.1. p. 18. 1st A careful reading of Chapter 6 of NUREG-2117 shows that the 12 paragraph. 1st line options are accept, refine. or replace. There is no "revise." Please clarify that the decision here is to replace. 13 Section 1.1. Page 18. Please define ISFSI with first usage. Paragraph 2. Line 3 Section 1.1. page 18. 2nd Will (in prep) documents be made available-Wooddell et al. (in 14 paragraph 14th line down prep); please see General Comments regarding such citations. 15 Section 1.1. Page 18. " ... regional GPS data. and several offshore studies and Paragraph 2. line 10 seismicity studies ... " Please indicate what types of offshore Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report studies were conducted. Geologic? Seismic? Section 1.1, Page 18, Please cite published report(s) and/or journal article(s) for 16 paragraph 2, Line 12: UCERF 3, and update the Wooddell et al. citation if report or paper is published (and if not, cite the section of the report where that work is presented). Section 1.1, p. 18, 211d The presence of new data, models, and methods requires that 17 paragraph, last sentence they be evaluated, as defined in NUREG-2117. They do not necessarily need to be incorporated into the SSC model, particularly if they are not found to be technically defensible. Section 1.1.1, 1st This is actually an existing regulation pertaining to license 18 paragraph, p.18, first conditions. The NRG therefore did not "issue" 50.54(f). They sentence issued a request for information pursuant to the regulation and related to NTTF recommendations. Section 1.1.1, Page 19, " ... site specific earthquake ground motion" addresses should 19 Paragraph 2, line 7 use ... " This statement is unclear. Please clarify what is meant by "addresses". Section 1.1.1, Page 19, Coppersmith and Bommer (2012) is not listed in the chapter 20 3rd paragraph of section, references section Line 4: Section 1.1.2, Page 19, Please consider referencing the report chapter that presents the 21 1s1 paragraph of section, sensitivity studies. 2nd sentence: Section 1.1.2, Page 19, Consider whether "complete" is the right word here. 22 1st paragraph of section, line 5: Section 1.1.2, Page 19, In the first bulleted line, are location and geometry the only foci 23 Paragraph 1 in the identification and characterization of active faults near the site? Consider also kinematics, rates. and recency of motion. Section 1.1.2, p. 19, The use of the term "explore" implies that some things were second bullet looked at (explored), but weren't necessary included. For 24 example. exploratory studies are a type of sensitivity analysis. If the intent here is to say that the range of uncertainty was "defined" and/or "included", then consider changing the terminoloav. 25 Section 1.1.2. Page 19-Please consider the suggestion to reference the report 20, bulleted list: section(s) appropriate to each bulleted item. 26 Section 1.1.2, Paoe 20, "Development of fault fault rupture models" that ... " Please Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report 1st bulleted line on page delete fault. Section 1.1.2, Page 20, If this is the first reference to "linked ruptures, complex ruptures, 27 1st bulleted line on page and splay ruptures", please define or include a reference to report section or other source where they are defined. 28 Section 1.1.2, Page 20, Please rephrase, as this is a run-on sentence. 3rd bulleted line on page Section 1.1.2, Page 20, Please change "incorporates" to "incorporate" as this refers to 29 4th bulleted line on page "models" (plural) Section 1.2, Page 20, Please correct "strike-slip" 30 Paragraph 1 of section, line9. Section 1.2, Page 21, last Please note typo and clarify number of Tl Team members. 31 paragraph of section, Lines 7-8: 32 Section 1.2, page 21, 3rd Three of six members four of five members not affiliated -paraqraph, 7th line down unclear which one? Section 1.2, Page 21, The 3rd subphrase "(3) ... new methods and .. . Are you Paragraph 3, line 10. referring to new data? What new methods were used? 30 33 seismic is not a new method, although it is newly applied to the SSC for DCPP. Please clarify what "fundamentally new methods" were applied. 34 Section 1.3, Page 21, 1st "provides our evaluation" -please specify who "our" refers to -numbered paragraph the Tl Team? Section 1.5, pages 23-24 The references need to be correctly formatted. For instance, 35 there is a U.S. NRC, 2012 and U.S. Nuclear Regulatory Commission 2012a. 2012b, and 2012c. Please correct these references here and in the text Chapter 2 Section 2.1. 1, p. 25, 2nd An opinion is a belief that does not require facts or evidence. 36 paragraph. 2nd sentence Judgment is the evaluation of evidence to make a decision. Suggest replacing "opinion" with "judgment." 37 Section 2.2. Page 27. 3rd " ... provided for bringing all members of the project team .. . paragraph, line 3 This is awkward. Please rewrite for clarity 38 Section 2.2.1, Page 27, Please note word repetition. last sentence of section: 39 Section 2.2.3, Page 28, "uncertainty" Consider pluralizing this word. Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report Paragraph 2. line 7 Section 2.2.3, page 28, Please clarify or correct the apparent conflict between this line 40 3rd paragraph of section, ("35 working meetings"} and Section 1.0, paragraph 2, Line 11, Line 2: ("53 Working Meetings"). 41 Section 2.2.3, Page 29, In reference to UCERF, are you referring to UCERF3? If so, Paragraph 8, line 18 please state. Section 2.2.3, page 29, It would be clearer if Dr. Lettis were included in this list, e.g.," .. 42 last paragraph on page, consisted, in addition to Dr. Lettis, of Dr. ... " Line 2: Section 2.2.3, page 29, Please resolve the conflict between this statement that Ms. 43 last paragraph on page, Hanson was added after Workshop 2, with the statement in Line 8: Section 1.4, page 23, line 8-9 on page, that says that Ms. Hanson was added "FollowinQ Workshop 3". Section 2.2.3, page 29, Please check whether the sentence (stating that the Tl Team 44 last paragraph on page, remained stable throughout the data integration and model Lines 11-12: building process} is strictly correct given that Kathryn Hanson joined the Tl Team after Workshop 3 (if that is the case}. Section 2.2.3, page 30, Inasmuch as "Mr. AbramsonWard and Dr. Thompson were 45 Line 2: younger scientists," please clarify whether the use of past tense here means they are now elderly scientists. 46 Section 2.2.4, Page 30, You might also mention that Dr. Rockwell worked on the LTSP Paragraph 2. line 14 in the 1980's Section 2.2.4, page 30, Please consider whether this statement is correctly phrased, 47 Paragraph 2 of section, given that Dr. Day's only other SSHAC Level 3 experience is Line 10: concurrent with this SSC study. Section 2.2.4, Page 30, Should read: "For Workshop 3, the members of the PPRP ... " 48 Paragraph 3. line 6 Section 2.2.4, page 30. Professor of Geology and Geophysics at Scripps 49 2nd paragraph, 5 lines down Section 2.2.4, page 31. For completeness. please also note the PPRP's responsibility to 50 listed items in 4th review the Project Plan. paragraph of section: 51 Section 2.2.4, Page Inconsistent usage of periods at the end of each bullet. Please 31,bulleted items make them all the same. 52 Section 2.2.5, p. 31, last In Figure 2-1, SSC Tl Team Staff Support is indicated by an sentence asterisk as being EEs. Is this correct? Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report Section 2.2.6, p. 31, P1 Of course. the REs did not present "raw" data without 53 paragraph, line 6 interpretation. The important point is that the REs avoid providing their interpretations of the data relative to SSC issues. That is the purview of the Tl Team. Section 2.2.6, page 32 Please replace "several" with "some." 54 1st paragraph 2nd to last line 55 Section 2.2.8, page 32, Please make Analyst was to "Analysts were" 1st paragraph 2nd line Section 2.2.8, page 32, Ms. Wooddell is identified as one of the Hazard Analysts, but 56 3rd to last line: her name does not appear in Figure 2-1 (the project organizational chart). Section 2.2.7, p. 32, last To avoid confusion of roles, consider adding a statement that all sentence participants were made aware of the fact that members of the Tl 57 Team were assuming the role of PE for purposes of the workshop, and they would then return to their roles as EE and Els. Section 2.2.8, p. 32, line Affiliations were given for the people identified above; consider 58 7 if they should be provided here as well. Likewise for Serkan Bozkurt in the next paragraph. Section 2.3, Section title: Please consider changing the title to emphasize the studies 59 rather than the contractors (i.e., the section is about the studies, the contractors being important but subordinate information). Section 2.3, p. 33 It may be useful to explain either in this paragraph or in Section 2.3.2 what the relationship is between the focus of the CRADA and the studies conducted specifically for Diablo Canyon. It may 60 be important to distinguish the role of the USGS, which conducts research for non-site specific applications. versus 1632 studies that are aimed at reducing uncertainties for the DCPP PSHA. Section 2.3. page 33. 2nd Please consider rewording this to reflect the fact that you are 61 to last sentence: summarizing focused studies done by contractors to PG&E (you mention the contractors as part of that summary, but you aren't merely compiling a list of contractors here). Section 2.3. 1, Page 33, Is the Diablo Cove fault considered "potentially active? Please 62 line9 refer to subsequent discussion of evidence of Quaternary activity on this fault. In line 14, is the Shoreline-Diablo Cove Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report fault interaction actually considered in this SSC? Section 2.3.2, Page 34, " ... and to evaluate slip rate on the Hosgri fault zone." Didn't 63 line 5 Sam Johnson actually "develop new slip rate data on the Hosgri fault zone."?? Section 2.3.2, Page 34, "lineaments in Estero Bay." What type of lineaments? 64 line8 Topographic? 65 Section 2.3.3, Page 34, "San Francisco State" should read "San Francisco State line9. University" Section 2.3.4, Page 34, "San Francisco State" should read "San Francisco State 66 line 3. University" Also, the second line of this paragraph seems redundant with the previous paraqraph/section. Section 2.3.4, page 34, It is not clear how the listed studies by Tl Team members are to 67 last sentence of section: be distinguished from "independent new detailed studies." If the intent of the sentence is to clarify the scope of Tl Team efforts, please reword. Table 2-1, Page 35 Jan Rietman is stated as being affiliated with FUGRO in the text and as a consultant in the table-please make consistent. 68 Also, please consider ordering the names alphabetically -this will eliminate the double naming of participants, as with Phil Hogan in Workshop #2 (listed twice). Section 2.3.5, p. 35, 2nd The Tl Team members in a SSHAC process are expected to paragraph evaluate ALL forms of data, models, and methods. This includes data gathered under a QA program, data provided in peer reviewed publications, and data gathered for other 69 purposes. This is because the experts on the Team are capable of evaluating the quality and applicability of those data. models, and methods. This does not mean that the data are "accepted into the SSHAC process" but that the data have been evaluated according to the SSHAC process. Suggest revising the wording in this sentence. Chapter 3 Section 3.1. p. 38, znd In Figure 3-1, there are called "essential steps." To avoid 70 paragraph confusion with the "essential steps" identified in Chapter 4 of NUREG-2117, suggest calling these four "components" as done in the text. Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report Section 3.1. 1, p. 39, 4th To avoid any perception that the PPRP was actually involved in 71 paragraph. last sentence the technical integration process, suggest substituting the term "reviewed," or something similar, for "involved." 72 Section 3.2, p. 40, last Where do these Working Meeting summaries" reside in the sentence project records? Section 3.2.1, general Please consider reserving the term "Workshop" for those comment: activities specifically defined as workshops in the SSHAC 73 NUREG documents (for example, Workshops 1,2, and 3 are structured quite formally and documented thoroughly, including a PPRP feedback letter; this was not the case for the kickoff meetinQ). 74 Section 3.2.2, Page 41, Here and elsewhere, please do not use "etc. List out any other Paragraph 2, line 9 items. Section 3.2.3, Page 42, significant parameters and features. Please clarify what is line9 " meant and implied here. Issues? Data? Interpretations? What 75 are parameters and features?? 76 Section 3.2.4, Page 42, Consider changing " ... and input into ... " to " ... and added to .. " Paragraph 1, line 4 77 Section 3.2.5, Page 43, "overlapping day with the GMC to discuss ... " Do you mean Paragraph 1, line 6 GMC Tl Team? Please clarify. 78 Section 3.2.5, Page 43, Please delete "etc." and list out any other items. Paragraph 2. line 10 79 Section 3.2.6, Page 44, "Several of the working meetings were observed ... " This is Paragraph 3, line 13/14 redundant with the previous paragraph -already stated. 80 Section 3.2.7, Page 45, " ... used to form the basis development of ... " This statement is Paragraph 3, line 5 unclear. Please clarify 81 Section 3.2.7, Page 45, Please indicate where the summary and PPRP letter are Paragraph 4, last line located. 82 Section 3.2.8, p. 46, 1st Are these the same as the WM Summaries identified on page paragraph. last sentence 40? 83 Section 3.2.9, Page 47, Please delete "etc." and list out any other items. Paragraph 2, line 9 84 Section 3.2. 1 O. Page 48. " ... the final model in light of the ... " Consider changing "in light Paragraph 1. line 6 of" to "using" to improve clarity. 85 Section 3.2. 1 O. Page 48. Please add "fault" after "Hosgri". as it is a formal name. Paragraph 2, line 7 Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report Chapter 4 86 Section 4.1, Page 51, Please define FSAR if this is the first usage of this term. Paragraph 4, line 2 87 Section 4.2.1, Page 51, "proposed Diablo Cove fault" -Is it a fault, or not? Please last line clarify "proposed" 88 Section 4.2.2, Page 52, The bulleted items do not have a parallel sentence structure bulleted items with the intro. Each should read correctly after" .... included:" 89 Section 4.2.2, page 52, University of Berkeley-University of California, Berkeley? 2nd paragraph, last line 90 Section 4.2.3, Page 52, The first bulleted paragraph is confusing. Please rewrite for 1st bulleted item clarity. Section 4.2.4, page 53, If this is the first occurrence of the acronym LESS, please define 91 1st paragraph of section, (it may be used freely thereafter, since it does appear in the Line 4: acronym table). Also, suggest putting "New" prior to Offshore 92 Section 4.3.1, Page 54, "Report" is repeated, but the acronym does not have an R. Is Paragraph 1, line 6. report part of the official title? Not clear. Section 4.3.1, page 55, "Low-Energy Seismic Survey" and "Onshore Seismic 93 3rd paragraph of section, Interpretation Project" should be written with initial capital last 3 lines of section, letters. Section 4.3. 1.1, page 55, If this is the first occurrence of the acronym HFZ, please define 94 1st paragraph, Line 4: (It appears in the acronym table, so it may be used freely thereafter). Section 4.3.2.1, Page 56, Non-parallel structure and confusing. Suggest " ... to the Hosgri 95 Paragraph 2. lines 4 and fault zone, were spaced -800 m apart {locally 400 m) along an 5 -94 km-long portion of the Hosgri fault zone, and crossed the fault zone 121 times." 96 Section 4.3.2.1. Page 57. Check spelling of "transect" Paragraph 3, line 4 97 Section 4.3.2.1. Page 57. "available at CSUMB (2010)." Is this a published source? It is Paragraph 4, line 4 not in the listed references. Please include. Section 4.3.2.1. Page 57. Sentence is incomplete; please check and correct. 98 5th paragraph of section, 1st sentence: Section 4.3.2.2. page 57, "tomoDD velocity model" is very specialized jargon. in the sense 99 1st paragraph of section, that "tomoDD" is the name of the computer program that Line 3 implements a particular analytical method. Please consider Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report rewording. either simplifying to "seismic velocity model". or to something that references the underlying analytical method, e.g., "seismic velocity model based on double-difference tomography". 100 Section 4.3.2.3, Page 58, Suggest moving "by" after (1) to be consistent with rest of Paragraph 1 paragraph. Section 4.3.2.4, Page 58, This sentence is confusing. " ... are incorporated into the 101 Paragraph 2 characterization of the Irish Hills-Estero Bay Local Areal Source Zone Irish Hills-that includes the Irish Hills." Please clarify. 102 Section 4.3.2.5. 1, page Reference section gives author name as Murray-Moraleda, 59, 1st paragraph, Line 1: which is not consistent with the citation in this paragraph. 103 Section 4.3.2.5.3, Page Rinconada fault2??? Are there two Rinconada faults? Is this a 59, ParaQraph 1, line 6 typo? Please clarify. Section 4.3.2.5. 1, page The citation is consistent with the reference section entry, but 104 59, 1st paragraph, Last not with the citation at the beginning of the paragraph. line: 105 Section 4.3.2.8, page 61, "San Luis/Pismo" is written "San Lui-Pismo" in the list of 1st bulleted item: abbreviations and acronyms. 106 Section 4.3.2.9, Page 62, Please rewrite this paragraph for clarity. Paragraph 1 Chapter 5 107 Section 5.2, page 69 Both SYRF and SYF labeled on Figure for Santa Ynez River Figure 5-1 Fault. Please make consistent. Section 5.2, Page 67, States that the contemporary plate boundary is a zone of strike paragraph 1, lines 4-5 slip faults and transpressional deformation, but wasn't the San 108 Simeon earthquake purely thrust? Plus, two of the structural models have the San Luis Bay and Los Osos as thrust faults. Is this statement correct? Please clarify. Section 5.2. Page 68. In the preceding section, the region is referred to as " ... zone of 109 Paragraph 2. line 1 right-lateral strike-slip faults ... ", whereas many of the faults shown in Figure 5.1 are left-lateral or oblique left lateral (Santa Ynez, Lion's Head, Casmalia, etc.). Please clarify. Section 5.2. 1, Page 68, Please add a reference for these ages: "(approximately 200 to Paragraph 1. line 1 66 Ma)". 66 Ma may be a bit young for the cessation of 110 subduction-related volcanism. as Sierran volcanism and pluton emplacement shut down by about 80 Ma, and it was even earlier in the southern California Peninsular Ranges (95 Ma). Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report Are you suggesting that subduction ceased at 66 Ma? Clearly, as stated earlier, the spreading ridge intersected the trench at about 28 Ma and flat-slab subduction was occurring after -80 Ma (hence, the cessation of Sierran volcanism). This section would benefit from additional supporting discussion and improved referencing. 111 Section 5.2.2, p. 69, 3rd Would it be helpful to mention the seismicity that is also paragraph, line 8 projected on to the cross section in Figure 5-4? Section 5.2.2, page 69 Please provide more information or reference to support 112 3nd paragraph 10 lines "surface slab does not appear to be disrupted by crustal faults" . down Is this based on microseismitv?? Section 5.2.2, p. 69, 3rd Please provide the basis for this interpretation or make 113 paragraph, second to last reference to a section of the report where the issue of the top of sentence the slab relative to the Hosgri fault is discussed further. Section 5.2.3, page 70, Onderdonk (2007) is cited but does not appear in the references 114 2nd paragraph of section, section. Line 7: Section 5.2.2, Page 69, It is stated here that subduction ceased 22-20 Ma at the latitude 3rd Paragraph, line 7 of DCPP, but it is earlier stated that the spreading ridge 115 contacted the subduction zone "directly south" of DCPP, which would imply a timing close to 28 Ma. In contrast, figure 5-3 suggests that contact occurred near present-day Los Angeles. Please clarify or correct. Section 5.2.2, Page 69, There is a lot of detail with no referencing, and alternative 2nd

• 3rd and 4th interpretations have been proposed in the literature. For Paragraphs instance, the notion that the main plate boundary jumped inland at 5 Ma is contradicted by many studies. There was clearly part of the main plate boundary already inland by 12 Ma -hence the 116 Miocene activity of the San Gabriel fault and the development of Ridge Basin (Crowell refs). Oskin and Stock argue for an earlier opening of the Gulf. as does Fletcher, and that the "proto-Gulf' is really no different than the modern Gulf of California, except where the locus of extension occurred. Please provide complete referencing in these paragraphs. Section 5.2.2, Page 70, "full plate motion of 30 to 35 mm/yr during the late Miocene." 117 5th Paragraph, line 2 According to many references, the full plate motion during the late Miocene was no different than it is today --52 mm/yr.

Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report Please provide additional justification and references, and soecifv the timinq of the increase in rate (12 Ma?) 118 Section 5.2.3, page 71, Please complete the citation for Atwater (2011} or provide an 4th paragraph, line 4 online URL. Section 5.2.3, page 71, If the San Miguelita and Edna faults were active at this time with 119 4th paragraph, line 8 lateral slip, the model requires them to be left-lateral. Is this model consistent with observations? Please elaborate. Section 5.2.3, page 71, Please consider whether the topic of "early sinistral transtension 5th paragraph, last between blocks and later dextral transpression" is discussed in sentence. Wilson et al., 2005. The paper is focused on the correlation of 120 volcanism and slab windows and does not appear to address the topic identified. If it does not, please provide a proper citation for this concept. Also, please explain why many of the E to NE-striking faults (Santa Ynez, Lions Head, etc.} continue to have late Quaternary left lateral or oblique LL motion. Section 5.2.3, page 72, Here it is stated 6.3 to 4.7 Ma. Earlier 5 Ma is used. Please be 121 6th paragraph, line 9 from consistent and provide a reference for this timing. top of page Section 5.2.4, Page 72, Please provide a reference for the statement that rotation in the Paragraph 1. line 3 WTR has stopped. This is a key issue as it affects expected motion on W-NW striking faults in the Santa Maria basin 122 province (Los Osos domain} -should see continued left-lateral oblique slip if rotation continues. At least some faults remain active, and Holocene left-lateral has been demonstrated on the Santa Ynez fault. Section 5.2.4, page 72. Please replace Carreaga with Careaga 123 1st paragraph 3rd to last line Section 5.2.5, Page 73, What sense of strike-slip? -please indicate. Within the Los Paragraph 2. line 4 Osos domain, the Shoreline fault is presumed to be right-lateral based on seismicity and observed offsets. whereas the San 124 Ynez fault is left-lateral in the Holocene. Other faults, such as Casmalia, Lions Head, Santa Ynez River faults, may be left oblique in terms of overall displacement, but Holocene slip and kinematics is not well-documented. Please explain the inter-relationship of these structures and how thev can be riqht-lateral Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report near the Hosgri and left-lateral farther inland. Section 5.2.5, Page 73, Here it is stated that faults in the Los Osos domain are dextral Paragraph 3, line 2 or oblique. Does this include the Santa Ynez and other sinistral 125 faults? These relationships should be explained. It is stated later that the San Luis Bay fault is reverse to left oblique based on kinematic indicators. Please provide clarification. Section 5.2.5, Page 74, Here the concept is introduced of continued clockwise rotation 126 Paragraph 3, 3rd bulleted of the WTR. If correct, this could cause a component of left slip item on all of the faults in the Los Osos domain, as they are being extruded to the NW. How does this work -please explain. 127 Section 5.2.5, Page 74, Please provide a reference to support the last line of this Paragraph 4, last line paragraph, which starts: "Evidence for downdropped or static ... " Section 5.2.5, Page 74, Please provide a reference for the statement that the San 128 Paragraph 6, line 2,3 Miguelita, Edna, and Pismo faults do not deform Quaternary deposits. Also, please specify where -the Edna may not be active in the Irish Hills, but may be active to the east. Section 5.2.6, Page 75, If the Los Osos domain is undergoing transpressional dextral 129 opening paragraph shear, consider whether this would preclude shortening due to continued rotation of the WTR. 130 Section 5.2.6, Figure 5-11 Please explain why only two solutions are shown for the HASH data. Are there sufficient data for more solutions? Section 5.2.6 Figure 5-13 This appears to be a minimum rate based on data (red dashed 131 line). Please provide more explanation on how the budget was determined. 132 Section 5.2.6, page 75, Please check spelling of Zheng (isn't this Yuehua Zeng?) 2nd bullet Section 5.2.6, page 76. Lewandowski and Unruh (2014) is not in the references. 133 2nd paragraph of section. Line 1: Section 5.2.6, page 76. DeMets (2012) is not in the references. 134 2nd paragraph of section. Line 4: Section 5.2.6, page 76. d3/s1 could be mistaken for a ratio, so please consider stating 135 2nd paragraph of section. this differently. 4 lines from end: 136 Section 5.2.6, page 76, Please indicate how the cited results differ from published work Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report 3rd paragraph of section, of DeMets (2012). and state the basis for those differences (or 2nd and 3rd sentences: reference the relevant part of the report). 137 Section 5.2.6 Figure 5-15 Annotations need to be rotated, also OWH has a p = 1.1 mm/yr? Section 5.3, Page 77, 1st Since the sensitivity results are being used to limit the selection 138 sentence: of faults for discussion, please provide a reference to somewhere in the report where those sensitivity studies are documented. Section 5.3, p. 77, pt Consider whether it would worthwhile in this introduction to paragraph discuss the concept of defining each fault according to its 139 characteristics along the reach closest to the site. It could be important to remind the reader that this is NOT a regional fault characterization {e.g., UCERF3), but a site specific SSC model. Section 5.2.6, page 77, "The model results showed more evidence for northeast-4th paragraph, 9 lines southwest directed contraction between the Los Osos domain 140 down (east of the Oceanic-West Huasna fault) and the San Andreas fault than within the Los Osos domain itself." Please provide additional discussion about the model as it appears to be different from other models. 141 Section 5.3, page 77, 1st "active and potentially active" Please provide criteria/definitions paragraph, 11 lines down for these terms. Section 5.3. 1, Page 78, Two alternative models are presented, but the wording is highly 1st paragraph of section, asymmetric. The first-cited references "interpret recently 142 Line 7 to 13: acquired offshore seismic reflection data to show, ... "whereas the latter-cited references "show" the contrary. Please reword to be consistent with the statement that these are alternative models. 143 Section 5.3.1, figure 5-16 "Possible Hosgri fault zone dip angles are shown on BB'." BB' should be AA'. Section 5.3. 1, page 78. "San Luis/Pismo block" is written as "San Luis-Pismo Block" in 144 2nd paragraph of section, the list of abbreviations and acronyms and in many other places Line 10: in the report. Section 5.3. 1, Page 79, 'These intersecting faults include the Los Osos, Shoreline, Paragraph 4, line 4. Casmalia and Lion's Head faults." This seems to imply that all 144 of these faults exhibit similar kinematics, but that is certainly not the case. The Casmalia and Lion's Head faults are similar to the Los Osos in that thev exhibit a laroe reverse component, but Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report their sense of lateral motion is unknown, and in section 8, the Casmalia fault is inferred to be left oblique to reverse. Please clarify the known sense of slip on these faults, as their sense of slip may control the validity of tectonic models, and whether the current transpression I shortening is the result of continued rotation of the Transverse Ranges, or some other mechanism. Section 5.3.1, Page 80, Refers to the Casmalia and Lion's Head faults as reverse to 145 paragraph 7, line 3 reverse oblique. Please indicate the sense of oblique slip, if known (LL or RL) and provide references. Section 5.3.2, page 80, "southeast" should be southwest. 146 1st paragraph, 6 line from bottom 147 Section 5.3.3, p. 81, 2"d Consider breaking up this very long paragraph. paragraph 148 Section 5.3.3 Figure 5-16 San Miguelita fault not labeled on figure. Section 5.3.3, Page 81, Provides the inferred dip of the SLB fault of -75 degrees and last paragraph of section, refers to Chs 8 and 9. It is difficult here, and elsewhere, to 149 last line confirm critical cross-referenced material without it in hand. Please provide referencing to specific sections of the report when they are available. 150 Section 5.4.1, p. 83, title Elsewhere "catalog" rather than "catalogue" is used. Please be consistent. Section 5.4.1., page 83, The terminology for the areal zones does not seem to agree 151 1st paragraph, 1st with Figure 5-20. In the latter, the innermost zone is labeled sentence: "Areal Source Zone," not "Local Source Zone." Please clarify and intended distinction. or make them consistent. Section 5.4. 1, page 83. Consider adding a short phrase (or a specific reference to 152 1st paragraph, Line 4, another section of the report) to define what is meant by "gridded seismicity rates." Section 5.4. 1, page 83. Please provide a reference to the report section where the cited 153 1st paragraph of section, sensitivity analyses are documented. last sentence: 154 Section 5.4. 1, p. 83, 1st Please specify that this is "structural" frequency (and not annual paraqraph, last sentence frequency). 155 Section 5.4. 1, page 83. If this is the first use of the acronym, please define it (it may be 2nd paraqraph of section, used freelv thereafter, as it does aooear in the acronvm table). Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report Line 2: Section 5.4. 1, page 83, It would be helpful for references to other parts of the report to 156 2nd paragraph of section. be specific as to section number. first listed item, last line: Section 5.4.2, page 84, To avoid confusion for the reader unfamiliar with the region, you 157 1st paragraph of section, might consider noting parenthetically that, while similarly last sentence: trending to the Los Osos, has an opposite dip direction. Section 5.4.2, page 84, The wording leaves the confusing initial impression that the 2nd paragraph, 1st topic of the paragraph will continue to be the San Simeon 158 sentence: Earthquake rather than the Lompoc Earthquake ("San Simeon is the sentence subject, whereas "Lompoc appears in a prepositional phrase). Please consider rewording this. Section 5.4.2, page 85, The meaning of "is considered in terms of' is not clear in this 2nd paragraph of section, context. If you mean, for example, that the available mission 159 Line 2, records (etc) place some bounds on the timing of the most recent event (as the subsequent sentence indicates), please consider usinQ some more direct wordinQ. Section 5.4.2, page 86, The phrase" ... more northwesterly compared to the more 160 1st sentence on the page northwesterly .. :*may have a typo in it. Please check and correct or clarify. Section 5.5, page 86, 3rd Please include in observation 2 a brief indication of how the San 161 line after the list: Simeon Earthquake supports the transpressional model (as you already do in the cases of observations 1, 3 and 4). 162 Section 5.5, page 86, 4th The sigma_1/d_3 could be confused for a ratio, so please line after the list restate to remove the ambiguity. Section 5.5, p. 86, znd What is the red star shown in panel (a) of the figure? Consider 163 paragraph re-sequencing the discussion here to be consistent with panels (a) then (b) of the figure. or reverse the panels in the figure. Section 5.5. Page 86.last These paragraphs describe two models on the styles of active two paragraphs on page deformation in the DCPP region, but both appear to be essentially the same in that the Hardeback transpression model shows pure shortening on the Oceanic. Los Osos, San Luis 164 Bay. Casmalia and Lion's Heads faults (in her figure), but so does the NE-SW-directed crustal shortening model of Lettis et al. (1994, 2004). How these models are distinguished is not clearly presented. Please clarify. Presumably the transoression model includes lateral slip on some or all of these Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report faults. but if so, please explain why the Los Osos fault in the OV model is RL oblique reverse, whereas the San Luis Bay, Casmalia and Lion's heads faults are believed to be LL oblique reverse to reverse. Figure 5-2 The model works until about 80 Ma, after which the slab flattened due to subduction of buoyant crust, producing the 165 Laramide Orogeny. More relevant to DCPP is the configuration that was frozen in place in the late Oligocene I early Miocene, presumably with a relatively flat subducting slab. Please provide a discussion of this configuration. 166 Figure 5-18: The orientation of the various cross-sections is not clearly explained in the fiQure or caption. 167 Figure 5-21: Legends are very difficult to read, especially in panel (b). Chapter 8 Section 8.2, page 94, 1st Please reference the section (and table or figure number if 168 paragraph. 2nd to last appropriate) where this sensitivity analysis is documented. sentence: Section 8.2, page 94, 1st Please replace "initial" with "completed" or just delete. 169 paragraph, 2 lines up from bottom Section 8.2, page 94, 3rd Please explain why the assertion here that the environment is 170 paragraph of section, 1st one of transpression doesn't contradict the approach introduced sentence: in Section 5.5 of considering both transpressional and NE-SW crustal shortening models of active deformation. Section 8.2, Page 94, Please indicate whether the transpressional strain referred to 171 paragraph 3 line 3/4 here is dextral or sinistral, and how these might change as the fault systems trend to the east and become more easterly in strike. Section 8.2. page 94. 3rd Note that this is a sentence fragment. Please rewrite. 172 paragraph of section, last 2 lines on page: Section 8.2. page 95. 2nd If this is the first occurrence of this fault name. please define its 173 to last paragraph of acronym at this point. section, Line 4 Section 8.2. page 95. last : Please note the typo: GDF means "cumulative distribution 174 paragraph of section, line function" (not "continuous"). 2 Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report 175 Section 8.2.1, Page 95 This presentation of new models would benefit from a more comolete discussion of the older models. Section 8.2.1.1, page 96, "Are judged" by whom? Please specify. If this is to be 176 3rd bulleted item: presented as a judgment by the Tl Team on the basis of the comment made about hydro-isostatic adjustment, please say so, otherwise cite reference. Section 8.2. 1.2, Page 97, The bimodal ages from Point Loma are not on the lowest Paragraph 1 terrace, they are from the 2nd emergent terrace, the Nestor terrace. Please correct. Also, the last line states that unlike 177 San Nicholas Island, Point Loma and Cayucos do not have fragments of the older -120 ka terrace at slightly higher elevation" Actually, there is a slightly higher terrace in the San Diego sequence but it is inferred to be the MIS 7 terrace (Kern and Rockwell, 1992). Section 8.2.1.2, page 97, It is difficult to follow the logic in this paragraph -is the 178 4th paragraph preferred interpretation that the 13 m terrace at Cayucos formed during MIS Se? Please clarify. 179 Section 8.2.1.2 Figure Figure is incorrectly labeled "San Nicolas Island. 8.2.1-5 180 Section 8.2.1.3, Page 98, Mentions a flight of 4-5 possible marine terraces, but lists the paragraph 1, line 1 elevations of only 4 terraces. Please clarify. Section 8.2.1.3, Page 98, Refers to a personal communication from John Caskey. The 181 paragraph 2, line 2 discussion appears to be quite speculative and need additional support. 182 Section 8.2.1.3, Page 98, "strongly developed soil" -is this documented? What are its paragraph 3, line 11 characteristics? Please provide a reference Section 8.2.1.3. Page 99. "pedimentation" is the wrong word here. Pediments form in paragraph 4, line 2 regions of vertical tectonic stability over long periods of time. In 183 this case. a flat surface can only result from marine planation of fluvial planation. neither of which would be considered pedimentation in this context. Please consider replacing "pedimentation" with "lateral fluvial erosion". Section 8.2. 1.3. Page 99. There seems to be a lot of conjecture in this paragraph, most of paragraph 4, which is not well documented except as a personal 184 communication. Please provide better documentation, explain and defend the statements in this paragraph, and include references. For instance, "it is unlikely that the Memorial Park Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report terrace surface is younger than about 400 ka" -please provide better documentation and discussion on this key age parameter, as it implies very low rates of uplift of Los Osos Valley. 185 Section 8.2.2, Page 99, Should this be equation 5. 1. There are other "equation ( 1 )" equation ( 1 ) usages in the report (c.f. page 133) 186 Section 8.2.2, Page 99, Is there a parentheses missing here? paragraph 3, line 4 Section 8.2.2, page 100, The abbreviation GDF means "cumulative distribution function" 3rd paragraph, Line 4: (not "continuous" distribution function, nor cumulative "density" 187 function). If you intend to say "cumulative distribution function" (as appears to be the case from the context), please reword appropriately. Section 8.2.2, page 100, Please be clear about how the CDFs may be combined (for 188 3rd paragraph, Line 8 example, perhaps you mean by forming a weighted sum with weights summing to 1.0?), or reference the report section where that explanation is qiven. 189 Section 8.2.2, p. 100, 5th Please replace "correct" with robust or has high confidence. paragraph, 5 lines down Section 8.2.2, p. 100, 5th If there is not a single correct (but unknown) slip rate for a given paragraph, last sentence section of a fault, then there must be some variability in slip rate along that section. Typically, the slip rate CDF would be assumed to represent epistemic uncertainty in what the "true" slip rate actually is for a particular section of fault of interest. If 190 the distribution also includes aleatory variability, as implied in this sentence, there should be a discussion of how that variability is estimated and distinguished from the epistemic uncertainty. Also. if that variability is dependent on the location along a fault. then that should be indicated and discussed as well. Section 8.3. page 101, The discussion would be easier to follow if the location of the paragraph 4, Line 4: Piedras Blancas anticlinorium were shown on Figure 8.3.1 (at a 191 minimum. some appropriate figure locating that feature should be referenced). 192 Section 8.3, Page 101, Are the seismic reflection data used to constrain slip rates or Paragraph 4, line 7 interpret them? 193 Section 8.3. 1, paqe 102, Please expand the discussion on the preferred offset, as the Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report Figure 8.3-2 figure only shows Oso terrace offset as a minimum at 150 m. Figure 8.3-3 mentions piercing points across the HFZ as the basis for preferred offset; consider labeling on Figure 8.3-2. Section 8.3.1 page 103, The discussion of Figure 8.3-3 would be easier to follow if the 194 2nd paragraph (and panels were labeled (i.e., a,b,c) and cited specifically (e.g., following paragraphs): Figure 8.3-3{a)). This comment applies to many of the composite figures in the chapter. 195 Section 8.3.1, Page 103, Traverse Range?? Do you mean Transverse Ranges, or 3rd bulleted paragraph WTR?? Section 8.3. 1 , page 103. "require reversal in uplift for the lower terraces" Please provide 196 3rd paragraph, 3rd bullet more clarification why the Muhs et al., 2012 studies on San 2 lines up Nicolas Island would require that. Section 8.3.1, page 104, The CDF curve does not plot exceedance probability, but rather 197 2nd paragraph on page, its complement. Please correct this, and check the use of the Lines 2 and 3: word "exceedance throughout the chapter, as it seems to be used repeatedly in this same erroneous sense. Section 8.3.1, Page 104, "hence broader, are not inconsistent with ... " This is a double 198 paragraph 7 (last of negative. Is it possible to make this more straight forward to section), line 2, 3 "are consistent with"? Section 8.3.2, page 105, "Cumulative density function" is incorrect. You may mean either 199 3rd paragraph. Line 3: "probability density function" or "cumulative distribution function" (probably the latter. since that is what appears in the last panel of the figure under discussion, Figure 8.3-5). Please clarify. Section 8.3.2, page 105, Please consider rewording to avoid ambiguity, since the 200 last paragraph on page, tabulated probabilities are not exceedance probabilities, but Line 2: their complements. Section 8.3.3, page 106, Figure 5-9 does not seem to show the Piedras Blancas 201 1st paragraph of section, anticlinorium. as the text implies. If it does not, please remedy line2: this inconsistency. Section 8.3.3, Page 107. Please elaborate on the implications of "the western branch of paragraph 4, last line the Hosgri is not the current locus of deformation." Does this 202 imply that this fault strand does not increase the Hosgri rate to the south? Please provide an explanation of the significance of this observation. 203 Section 8.3.4.2. Page Please rephrase this sentence as it is not clear. 109, Paragraph 4, line 7 204 Section 8.3.4.3, Paoe "at least five olacial terminations" Are vou referrino to maior Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report 110, Paragraph 4, line 4 (100 ka) glacial phases, as appears to be the case? If so, olease indicate that these are maior alacial terminations. Section 8.3.4.3, page "Paleo slope breaks associated with unconformities H10 and 111, 7th paragraph, 5 H30 occur more than 1 km west of the paleo slope break lines down associated with unconformity H40 (PG&E, 2014, Chapter 3 Figure 6-3, and Figure 8.3-6) suggesting that the lowstands 205 preceding H10 and H30 reached significantly greater depths than the lowstand preceding H40. This relationship strongly supports the preferred unconformity age model and contradicts the relationships that would be predicted by the alternative model (Figure 8.3-7). This argument is important and would benefit from additional discussion. Section 8.3.5, page 113, Could the relatively high amplitudes from the channel thalweg 206 5th paragraph, 7 lines be gas? Please consider whether gas might give rise to some of down the observed chanQes in acoustic reflectivity. Section 8.3.6, page 115, "Due to this uncertainty, the Tl team assessment of offset 207 2nd paragraph, last across the fault does not rely directly on channel Fe. How does sentence this affect overall slip rate estimates? What were the estimates from the PG&E 2014 CH3 report? 208 Section 8.3.6 page 116, Fe1 and FW1 are not shown in Figure 8.3-16 Figure 8.3-16 Section 8.3. 7, Page 116, As stated later, the slip rates to the north are expected to be Paragraph 1 higher than at DCPP, whereas the southern slip rate is 209 expected to be lower due to pulling slip I deformation off onto the Los Osos, San Luis Bay and other faults. Please discuss the implications of combining all of the rates into a single CDF. Section 8.3.7, p. 116. 1st This statement would appear to imply that the slip rate paragraph. last sentence estimates at each site are epistemic assessments of the true rate at each site, but the weights assigned to each of the sites represents the degree of belief that any given site is an indicator 210 of the rate along the fault near the plant site. This is all epistemic uncertainty. However, as stated below in the last sentence of this paragraph, the integrated distribution might also have an aleatory component in it, implying that there is true variability in the slip rate opposite the plant. Please explain if this is the case. 211 Section 8.3.7, p. 117, 2nd Does this imply that there is aleatory variability in the inteorated Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report paragraph. last sentence distribution across all sites? 212 Section 8.3.8.3, page Please note that the first column heading should be "Zeng" (not 120, Table 8-1. "Zheng"). 213 Section 8.4. 1, Figure 8.4-The CDF table may have a typo, as the first two entries give 6: different cumulative probability, but at the same slip rate. Section 8.4.1, Page 123, Refers to the "lateral slip is a good approximation of the net slip 214 paragraph 3, line 3 rate." But that hasn't been presented yet. It may be better to state that it "will be" a good ... Section 8.4. 1, page 123, It is important to determine if the terrace riser is older or 215 4th paragraph, 10 lines younger that H40 -Are there any seismic data, that would allow down the Tl team to trace H40 from the west? 216 Section 8.4.1, Page 123, The last 10 or so lines of this paragraph are somewhat paragraph 4, confusing. Could this be made clearer I simpler? Figure 8.4-5 Lower part of figure has an arrow to the right with 630 ka, which 217 refers to the possible upper end of the age range of the terrace sequence. In the text on page 124, 1st paragraph, 625 ka is stated. Please be consistent. Section 8.4.2, Page 124, Please reference Figure 8.4-2 providing the map showing 218 1st paragraph of section, location of channel I, which the subsequent discussion in this 1st line: paragraph relies upon. Section 8.4.3 Page 127, Please reference Figure 8.4-2, which provides the map showing 219 1st paragraph of section, location of channel A that the subsequent discussion in this 1st line: paragraph relies upon. Section 8.4.3, Page 127, Please explain what observation or analysis led the Tl Team's 220 3rd paragraph. second to interpretation to differ from the previous PG&E interpretation. last sentence and last sentence: Section 8.4.3, Page 128. The assumption here is that lithology and stream power are 6th paragraph. lines 9-10 similar over time. which is likely the case as these three "streams" likely originate from the same drainage source. This 221 should be made clear that they all have the same source. and that the drainage area has not likely evolved much to its present state over the expected age range of these three channels. Otherwise, the rest of the arguments in this section fail. ection 8.4.3, Page 129. Should the reference be to Figure 8.4-13? 222 2nd paragraph on page, Line 7: Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report Section 8.4.3, Page 129, Please summarize what specific observations and/or analysis 223 2nd paragraph on page, led the Tl Team's age model to differ from the previous PG&E last sentence: model. Section 8.4.3, page 129, Might want to rephrase the sentence below so it is clear that 9th paragraph, 3 lines Channel A is older than Channel C -The MIS 6 age alternative down is preferred and assigned a weight of [0.7] based on the 224 observation that Channel A is crosscut by Channels Band C, and therefore must be older than them (Figure 8.4-11) and the greater depth of incision of Channel C, suggesting it is likely a full sea-level cycle older than Channel A (as described above and illustrated in Figure 8.4-12)." Section 8.4.4.2, Page The San Luis Bay "kinematic indicators of strain (slickenlines) 131, 2nd bulleted point are compatible with reverse or reverse left oblique slip" This is 225 the first time that the possibility of left oblique slip has been raised. Is this congruent with the OV model, which implies right oblique slip on the parallel Los Osos fault? Section 8.4.4.2, Slip rate "Based on this assessment, the uplift rate of the Irish Hills 226 of SWBZ, page 132, 1st ranges from 0.15 mm/yr to 0.35 mm/yr, but most likely is paragraph 7 lines down between approximately 0.18 and 0.23 mm/yr." Please expand on why is it most likely? Section 8.4.4.2, Page The input parameters for the resolved slip calculation are in 227 133, 3nd paragraph on Figure 8.4-15 (not 8.4-16). page, Line 1: 8.4.4.2, Page 134 and This discussion seems to indicate that the vertical rate on the 135 Shoreline fault is possibly on par with the horizontal rate (up to 0.11 mm/yr vertical. with a best estimate of 0.07 mm/yr 228 horizontal). Is this consistent with other interpretations that the Shoreline fault is mostly strike-slip? (focal mechanisms, offset channels and shoreline features, vertical dip, etc.). Please clarifv the suooort for this interpretation. Section 8.4.4.2. "The second age model is called the post-LGM age model. This Constraints on Vertical model, which is assigned a weight of [0.4), accounting for the Separation Rate Offshore possibility that the wave cut platforms mapped by PG&E (2011) 229 of Irish Hills, page 135, do not represent long-lived stillstands, and may instead be 3rd paragraph, 15 lines erosional surfaces developed during the last transgression." down Please provide additional justification for this weight, given the Tl's assessment that the MIS 3 -5 age is likely to be "correct". Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report Section 8.5, page 136, Please consider referencing the section of the report where the 230 2nd paragraph of section. concept of "fault models" was defined and the NE, SW and OV 2nd to last line: cases introduced. Section 8.5. 1, page 138, Hanging wall uplift-rate PDFs (Figure 8.5-2) and footwall uplift-rate PDFs are all bounded density functions. Please explain how bounded PDFs (as opposed to discrete probability mass 231 distributions) can combine to give the discontinuous CDF's shown in Figure 8.5-6 (hint: they can't), or clarify how the CDF's in Figure 8.5-6 were actually calculated, or correct the plot (and subsequent ones) if it is erroneous. Section 8.5. 1, page 138, "The maximum value considered is -0.21 mm/yr based on the 4th paragraph, last assumption that the magnitude of hanging wall uplift (preferred sentence uplift rate of the Irish Hills) is the upper limit on footwall subsidence as predicted by various structural models (e.g., King et al., 1988; Stein et al., 1988)." 232 Please provide clarification here as hanging wall uplift causes rock to displace air -large density contrast; whereas foot wall subsidence causes crustal rocks to displaces mantle -small density contrast -it is the density contrast and associated buoyancy that controls magnitude of subsidence. Thus subsidence is larger than associated uplift for both extensional and compressional environments. Section 8.5.1, page 138, Please state the rationale that the selected fault dips adequately 233 last paragraph, 1st represent the full technically defensible range, or reference the sentence: section of the report that does so. Section 8.5. 1, page 138, Please state the technical justification for the range of rakes 234 last paragraph of section. employed. 2nd to last sentence: Section 8.5. 1, page 138, The terminology used in Figure 8.5-7 is ambiguous. What does last paragraph of section, "deviation from vertical" mean there? Unless the fault has a dip 235 2nd to last sentence: of 90 degrees, then there is no vertical reference direction within the fault plane. If you mean the complement of the rake angle, please say so (or "deviation from the up-dip direction"). Section 8.5.1, Page 138, Here, the Memorial Park terrace is potentially correlated to the 236 paragraph 6, line 14 -400 m (should read -400 ka); ... Earlier, 400 ka was suggested as a minimum age for this terrace. Which is it, and Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report what is the likelihood that it is younger, as this discussion was not verv clear earlier in the reoort. Section 8.5.2 page 138, In discussing Figures 8.5-8 through 8.5-10, please explain how 237 1st paragraph of section, the net slip rate can have a continuous CDF {implying a Line 2-3 bounded PDF), while vertical rate has a discontinuous CDF (implying a discrete probability mass distribution). Section 8.5.3, Page 139, The expression "the center of the range" is used here without 1st paragraph of section: definition. It seems to correspond to the 21st to 79th percentile 238 values in Figure 8.5.11, but similar expressions {e.g., "center of the PDF") have been used previously in the report for intervals defined differently. Please make the intended meaning clearer here. 239 Section 8.6, Page 1, 1st Note the extra ".)" at end of paragraph. paragraph, last line: Section 8.6.1, page 1, 1st Please reference the section of the report where the alternative 240 paragraph of section, last age models were evaluated and the weights cited here were line: justified. Section 8.6.1 page 1, 2nd If this statement refers back to an assessment from an earlier 241 paragraph of section, 2nd part of the report, that section should be referenced. In not, sentence: please provide a more complete statement of the technical justification here. Section 8.6.2, page 1, 1st "Deviation from vertical" is not an acceptable terminology, 242 paragraph of section, 1st because it is ambiguous (there is no vertical reference direction line. in the fault plane unless dip is 90 degrees). Please use a conventional and unambiguous terminology. Section 8.6.2, page 1, 1st Please explain why the CDF for the vertical rate appears to be 243 paragraph of section, last discontinuous (stepped) in Figures 8.6-2, 3, and 4 (which would line on page: imply a discrete probability mass function). or correct the figure. Section 8.6.2, page 2, Please state the technical justification that the selected fault 244 last paragraph of section. dips adequately represent the full technically defensible range, Line 2: or reference the section of the report that does so. Section 8.6.2, page 2, The sentence refers to a PDF for fault rake. but the range of 245 last paragraph of section, angles cited seems to apply to the complement of the rake. last sentence: Please check and make a correction if needed. Section 8.6.2, page 2, Please clarify the meaning of the "plus or minus 1 degree" in the 246 last paragraph of section, description of the distribution. last sentence: Comment Location in Text1 PPRP Comment Summary of Revisions Number to Report Section 8.6.2, page 2, Please state the technical justification that this rake angle 247 last paragraph of section, distribution adequately represents the full technically defensible last sentence: range, or reference the section of the report that does so. Section 8.6.3, Page 2, Please indicate left or right oblique. If right oblique, please 3rd bullet explain why it is different from earlier statements that kinematic 248 data suggest left oblique to reverse. If right oblique, please explain (somewhere) how the SLB and Los Osos faults, which are nearly parallel, can have the opposite sense of oblique slip, if that is the case. Section 8. 7, page 1, 1st "San LuisPismo" is written "San Luis-Pismo" in the list of 249 paragraph, line 1: abbreviations and acronyms, and in most occurrences elsewhere in the report. 250 Section 8.7.1, Page 1, Please indicate whether the oblique slip is left or right oblique. Paragraph 2, last line Section 8.7.1, page 1, Please provide a reference to a report, or to a section (and 251 2nd paragraph, Line 1: figure) of this report, that documents the sensitivity analysis cited here. Section 8.7.2, page 2, Please check whether "Wilmar Avenue fault" should be "Oceana 252 last paragraph on page, fault" instead. Line 1: Figures in Chapter 8, The discussions of total slip and age PDFs and the associated general comment: slip-rate CDFs in the chapter would be easier to follow if the 253 multi-panel figures such as Figure 8.3-3, 8.3-5, and many others, had panel labels (i.e .. "a", "b", "c", etc), and if the individual panels were referred to by letter in the text (e.g., "Figure 8.3-3a"). 254 Figure 8.5-5: Is the location of the D-D' cross-section shown in Figure 8.5-5? 255 Figure 8.5-7: "Deviation from vertical" is ambiguous: please correct this. Figures 8.5-8, 9 & 10: "Deviation from vertical distribution" (footnote to the table on 256 right of figure) is ambiguous: please replace with standard, unambiguous terminology. Figures 8.6-2, 3, & 4: "Deviation from vertical distribution" (footnote to the table on 257 right of figure) is ambiguous: please replace with standard, unambiguous terminology. 258 Figures 8.6-2, 3, & 4: In the footnote to the table on right of each of these figures, the meaning of "1-19 degrees plus or minus 1 degree" is unclear. ATTACHMENT PPRP COMMENTS ON DCPP SSC DRAFT REPORT INSTALLMENT #2 Comment Location in Text PPRP Comment Summary of Revisions to Report Number General Comments 259 Overall, the chapters that comprise Installment #2 are well written and provide the necessary documentation for several elements of the SSC model. As noted in Installment #1, the text would benefit from a comprehensive technical edit to ensure consistency in the usage of various terms, tense, third person, etc. Such an edit would also allow for more specific internal referencing to other sections of the report. Suggested edits are provided in these comments, but they are not exhaustive. 259 As noted in the PPRP comments for Installment #1. it is strongly recommended that figure captions be developed for every figure to assist the reader in understanding the salient points of each figure. Title blocks and notes are helpful, but they often do not adequately convey the messages that the figure is intended to convey. 260 Throughout the text, the terms "SSC" and "SSC model" are used interchangeably. Common usage would dictate that the elements of the SSC model should be indicated as such, and that the activity of characterizing seismic sources should be termed SSC. Editing the text for consistent usage is recommended. CHAPTER 6-Seismic Source Characterization Overview 261 Line 14 Please check whether "piecewise planar** would better convey the intended meaning here and on Line 33. 262 Line 20 Please state, in some quantitative terms, the threshold to be considered to "contribute significantly." 263 Line 28 If this is the first usage in the report of the terms "maximum earthquake" and "floating earthquakes", please define or indicate the subsequent section of chapter 6 in which the definition will be given (they are defined on Lines 177-179. for example). Otherwise provide a reference to the previous report section where they were defined. 264 Lines 34-35 Please explain difference between seismogenic or potentially seismogenic. 265 Line 36 Please provide more detail regarding sufficiently active. Presumably this relates to recurrence rates. 266 Line 38 References to depth here. and in several other places in the chapter, are ambiguous. Please establish. in each case in which it matters, whether the reference is to depth to top, depth to bottom, or some other quantity (e.g., depth extent). 267 Lines 43-44 Please consider rephrasing to the following -Key data from the DCPP region are needed for fault slip rates and the time since the most recent earthquake 268 Line 46 Non-specific or non-specified? 269 Lines 53-55 Please cross reference where hazard sensitivity studies show that the SAF has only a small effect on hazard 270 Line 62 Please provide a more specific reference (section number and figure number(s)). 271 Line 63 "fault" should be plural 272 Line 63 Please showfreference lngley site on a figure. 273 Line 68 "Recent historical" seems redundant, especially for California as we have such a short historical record. Are you implying there are "older historical" earthquakes? 274 Lines 57-88 It is recognized that the conclusions presented in these paragraphs regarding recency, displacement per event, and recurrence intervals are summaries of the conclusions drawn elsewhere. However, the reader would benefit from specific references to the locations in the report andfor the primary references where the data have been evaluated and the conclusions and uncertainties have been developed. 275 Lines 76-79 "Selected historical ruptures that we considered in developing both Fault Geometry Models and rupture sources for these fault sources (discussed below in Sections 6.3.1 and 6.3.3, respectively) are listed in Table 6-1 " Please move parenthetical phrase to end of sentence. This occurs many places in the text and it would make the document flow better if they were at the end of the sentence where possible -see below 276 Table 6-1 One other wel I-studied earthquake to consider in this table is the 1999 Hector Mine earthquake, as it nucleated on a splay fault and then ruptured bilaterally. It also produced secondary rupture on a number of small faults. 277 Table 6-1 The source faults in the 2010 El Mayor-Cucapah rupture were not previously unidentified, as stated. These were all mapped by Barnard as part of his PhD thesis, and have been shown in a number of published sources. All were named faults prior to the earthquake. What was not known is how all of these faults work together to accommodate oblique strain. 278 Lines 104-105 Please nesh out this line of reasoning out-The founding of the mission at SLO in 1772 together with the lack of reported earthquakes in mission documents provides a rationale for settina Tmin=242 vr. 279 Line 107 "Missions were sensitive to strong ground motions" Please expand. 280 Line 118-120 Please consider rephrasing -In summary, the lack of any damage reports in documents from the San Luis Obispo mission make it unlikely an earthquake of M6.5 or larger on DCPP Primary and Connected faults since 1772. 281 Line 131 Figures 6-2 through 6-7. Consider presenting Table 7-2. Primary and Connected Fault Section Codes and Descriptions here in Chapter 6 where figures are first presented 282 Line 137 Please provide a more specific reference, i.e., number of section and figure(s), where the relevant sensitivity studies are described. 283 Line 172 Please note the typo: should be Figure 6-7 (rather than 6.7). 284 Line 174 Figure 6-7. Should a rupture source S4+S5+S6+S9+S10 be listed? 285 Line t80 This is one example of the usage of "SSC" where "SSC model" is recommended. Please ensure proper terminology throughout the text. 286 Line t85 Please remove "is" 287 Lines 204-205 "over the forward-modeling rupture model approach taken for the Diablo Canyon SSC model" Model seems to be over-used in this sentence .. 288 Line 212 Please remove "wide" 289 Line 215 Would the Hosgri fault be considered low slip rate and "within the noise?" Might want to temper this a bit by clarifying that the DCPP SSC model needs to deal with lesser faults and detailed characteristics of Hosgri fault. 290 Line 246 Consider adding a sentence noting that a forward modeling approach does not imply that there are no overall constraints in the SSC model on such things as cumulative slip rate and defo1111ation rate. Rather. it just means that those constraints are not formally imposed within the framework of an inverse modeling approach. 291 Line 248 Please change displacement to displacements. 292 Line 264 PDF is used to indicate a probability density function 293 Line 289 Please consider whether the meaning would be clearer if the passage were rewritten as "such that, when the contributions from all rupture sources that include a particular fault are summed,". 294 Lines 294-296 Are the slip rates uniform over the entire rupture source for the main fault (larger slip rate) and uniform over the entire rupture source for the secondary fault (smaller slip rate)? Please explain. 295 Line 321 Please give an indication of what magnitudes would be considered "moderate to large." 296 Lines 330-331 The last line of the paragraph is unclear as to its meaning. "the number of events captured is very few or is difficult to distinguish." The first part makes sense -the number of events is very few. The second part is unclear -"the number of events is difficult to distinguish." Distinguish from what? To count? To dete11T1ine? 297 Lines 332-338 Long sentence, please consider breaking it up. 298 Line 340 "understood to accurately model -please change to -understood to model accurately 299 Line 343-345 "but few are sufficiently large to preclude throughgoing fault rupture." Please consider adding lo end of sentence -based on observations from other segmented strike-slip fault systems (Wesnousky. 2006). 300 Line 346 Please define "behavioral." 301 Line 350 Figure 11-8 should be Figure 11-9. 302 Line 358 Please note the typo: "MDF" should be "MFD". 303 Line 361 "by maximum rupture source size** would read better as "by the maximum rupture ... " 304 Line 361-362 It is not clear how this sentence relates to the previous sentence. Does the maximum rupture source size relate to the characteristic earthquake rupture dimensions? 305 Line 363-364 Please consider expressing this differently. Do you mean that the absence of that information is not a rationale for precluding characteristic-model behavior as part of the technically defensible range of models? 306 Line 367 Please consider using a more descriptive term such as "exponential MDF" here, since another exponential distribution (i.e., for recurrence times in a Poisson process) comes into the discussion elsewhere in the report. 307 Lines 370-375 Is this saying that "faults and portions of fault networks that have been modeled with characteristic earthquakes can ALSO be modeled with exponential distributions? Or that faults and portions of fault networks that are modeled individually with characteristic earthquakes can be represented in aggregate with exponential distributions? 308 Line 379 What is an historical limit? Is this the observed maximum for the fault? For any fault of the same slip type? Please clarify. 309 Line 379 Consider replacing accidently with coincidentally. 310 Line 393 "equally durable scrutiny" Please consider replacing with -much scrutiny 311 Line 396 Please consider whether there is a published article or report that could be cited instead of the unpublished powerpoint presentation 312 Line 410-413 Please provide the justification for the sole selection of this relationship in light of these issues. For example, why is this relationship preferred in light of the "dimensions and style of faulting? the tectonic setting? The "application of magnitudes in the PSHA"? 313 Line 414 Please consider whether "end-member" is the optimal characterization of the set of proposed magnitude PDFs (Le., what distribution are they end members of? Does that distribution have four endpoints?), or whether instead the set actually includes samples from throughout the distribution of proponent models. 314 Line 420 Please delete the citation of an article that is "in preparation," or update the citation to a published article. If that manuscript is unpublished but contains elements essential to this report, please include those elements in Appendix WAACY. 315 Line 426 Please provide the rationale for the selection of these magnitude PDFs for each rupture source type. Also, please provide the justification for the branch weights cited here, or provide a reference to the report section where that justification is given. 316 Line 428 6.3.6 Time Dependency Model. Please consider moving this section up in the chapter so that the sections mirror the order of the logic tree shown in Figure 6-1: Time Dependency Model, FGM, Rupture model, Slip rate Allocation model, MDM 317 Line 435-437 Suggest clarifying that the theory relates to individual faults. PSHA began with the representation of seismic sources as zones that likely included multiple faults and, as a result, these behave more like a Poisson process. 318 Line 443 This line refers to "coefficient of variation in the long-term mean rate." That would be an epistemic uncertainty. However. please check whether that is the actual intent on this line, or whether the intended reference is to the coefficient of variation in the recurrence model (and which represents aleatory variability in recurrence time associated with a given long-term mean rate J? 319 Line 448 What is meant by a "global parameter?" 320 Line 452 "many tens of active faults". Please consider removing -tens of 321 Line 453 Please replace "to" with " do" 322 Line 456 Please give a more specific reference to the sensitivity analyses that support this statement about the hazard contribution from regional sources (i.e., by citing section number(s) and figure or table number(s) where the relevant analyses are presented). 323 Line 466 "included as a fault sources". Either drop the "a" or change sources to singular. 324 Line 466-467 Why is a conservative characterization used? How do you know that it is conservative? 325 Line 475 Please indicate who is doing the judging in this and the next sentence. 326 Line 508 Please explain what is meant by a "point source" in this context. 327 Figure 6-1 caption Please replace loger with longer. CHAPTER 7 -Fault Geometry Models 328 General Please make references to other parts of the report as specific as possible, i.e., by providing section number(s), and figure or table number(s) where appropriate. Some instances where this is required are noted in specific comments, but please review the chapter for other nstances and make appropriate changes. 329 Line 5-6 K;ommon usage would call this a seismic source characterization "model." 330 Line 10 Figures 6-2 to 6-5 are maps showing Primary and connected fault $ections not "Figures 6-5 to 6-6" as listed 331 Line 18 $uggest making reference to the logic tree that shows these alternatives Md weights. 332 Line 81 Please provide a more specific reference to the section(s) of Chapter 13 where the discussion cited here is presented. 333 Line 83-84 Please provide a more specific reference to the section(s) of Chapter 14 hat substantiate the claim made on these lines. 334 Line 96-97 r-.'ou may also want to cite the deepening of seismicity after the 1999 lzmit l:!arthquake. Seismicity deepened by -3 km, and recover over the "allowing 6 months (BenZion et al) 335 Line 107-113 Please provide references to articles or the report section(s) that present he observations and interpretation cited here. 336 Line 118 rre1111inology is odd. Suggest changing "allowed to" to "assessed to." 337 Line 131 these spatial patterns of epicenters and hypocenters? Does this 'nclude focal mechanisms and their associated geometries? 338 Plate 7-1 Plate 7-1 . Why are the names of rivers and creeks highlighted by blue IJoxes? Please remove blue boxes around names of rivers and creeks. 339 Line 164 rrhe wording on this line is ambiguous. Please rephrase this passage to whether it is the "simplified representations" or the "actual faults hat are shown in the cited figures. 340 Line 172 Please specify by whom it is considered to be insufficiently wide to be a IJarrier, and on what basis. Unclear what is meant by *'universal" in this It sounds like the Team made an assessment that the basin is not $ufficiently wide to represent a barrier to ANY future ruptures? 341 Line 174 'single fault connected fault source." The first fault" could be deleted without losing anything. 342 Table 7-2 In reference to the Wilmar Avenue fault, it would be best to spell out 'Avenue" as it is a proper name. 343 Lines 188-190 Please consider rephrasing to the following Two boundaries between fault sections that are not intersections between Primary or Connected fault sources are discussed below 344 Line 217 Please specify by whom (e.g., the Tl Team) such geometries are assessed to be the only valid ones. and consider whether the intent of this ine would be better conveyed by the phrase "technically defensible" in l>lace of "technically valid." 345 Line 218 Please explain in the caption of Figure 7 -4 the meaning of the additional Mnotations such as "<0.05 m/kyr," that appear away from the dashed curves (e.g .. are these point constraints based on specific pbservations; or are they regional generalizations, and, if so, how wide an do they apply to?). 346 Lines 242-246 Please provide a reference to the specific report section(s) where this assessment is justified. 347 Line 245 'convincing evidence of unique fault geometry". Please consider changing 'of unique" to -for well defined 348 Line 292 Please define the rake ranges that distinguish the "reverse" sense of slip *rom the "reverse oblique" sense of slip, since this distinction was not !Jiven on Lines 259-264. 349 Line 307 is required after "bathymetry data" for clarity 350 Line 308 Figure 7-5 is a good example of how figure captions would greatly help he reader interpret the panels of the figure. 351 Line 309 'DCPP that were compared to evaluate. Please consider replacing 'compared with -examined 352 Line 338 'The HFZ is the best imaged, most continuous, and complex fault zone" 'complex" -scale dependent, thus level of complexity is dependent on maging resolution -some of the faults in the Irish Hills could be equally or more complex than the HFZ?? Please clarify. 353 Lines 341-343 'Locally, strands of the fault zone exhibit seafloor expression, either as fault-line scarps, or possibly also as tectonic scarps within young Please expand to explain differences between the two. 354 Line 343 Some explanation is needed either here andlor as a figure caption what the ages of the MIS tracts and unconfonmities are in the 0igure. 355 Lines 351-352 Please explain how "aleatory uncertainty" can be captured by modeling 'alternative near-surface traces." That is, doesn't the word "alternative" mply epistemic uncertainty, and that the options for the trace location are mutually exclusive (and isn't that the thrust of the discussion on Lines 390 1404), which would preclude them acting in concert to produce aleatory 356 Line 356 Please check whether there is a peer-reviewed report or article (locumenting the study of Hardebeck cited on this line, and if there is, please cite that in preference to the unpublished Workshop 2 oresentation. 357 Line 363 Please consider replacing "apparently" to -interpreted to be 358 Line 369 K;onsider replacing "and also" with "along with" 359 Line 376 rThe seismicity is projected onto a plane that is perpendicular to the strike K>f the Hosgri fault. Also. ii is very difficult to see the plus signs and dots on he figure. Can they be enlarged? 360 Lines 379-382 Please explain the basis for the proposed associations of hypocenters to f-aults, and note any other analyses that were undertaken to try to resolve he apparent ambiguity in those associations (as seen in Figure 7-9). For can the association of hypocenters to the Hosgri fault be mproved by restricting the cross-sectional projection to events located of DCPP (avoiding interference from the northernmost part of he Shoreline Fault and Estero Bay seismicity)? 361 Line 382 to the legend, the plus symbols represent "uncertain !association." 362 Line 393 Please explain in what sense model H85 is the best fil to the seismicity. 363 Line 398 Figure 7-11 indicates "systematic offset" which could be better defined as possible systematic offset of hypocenter locations from the fault. Also, 'possible future data" is cited in the figure text but is nol discussed in the ext. 364 Lines 400-401 The H90 model fits the seismicity data, but is less consistent with fold (leformation that appears to indicate a flower structure on the reach !adjacent to the DCPP. " h°here are many fault segments offshore, could the fold deformation and 'lower structures be explained by constraining bends along a vertical fault -H90? 365 Line452 'North" Please replace with -Northwest 366 Lines 464-466 'The concept of the outward-vergent (OV) model is that uplift of the SLPB s produced by transpressional right-reverse faulting along the riortheastern and southwestern block boundaries (Figure 7-13)." Please explain/discuss. The Shoreline is a vertical strike-slip fault. Reverse slip is occurring toward the southeast on BE, WA and OF fault Such a configuration would predict uplift rates to increase oward the southeast -in contrast to the observations? 367 Line 469 Figure 7-14. Please discuss constraints on Los Osos dip from segment LE ::so') to LO (60°) 368 Lines 475-476 Uunction with dexlral-reverse Oceanic-West Huasna fault is not shown in Figure 7-13 369 Line476 Figure 7-13. Please discuss intersection of OF and SF -does lhe reverse die toward the northwest? Why is there no reverse motion along SF? 370 Line488 If the phrase seismic source zone" on this line means the same thing that 'areal source zone" or "Local Source Zone" means in Chapter 6, please the appropriate one of those previously defined te1TT1s to provide a te1TT1inology throughout the report. If is means something else, IJlease define it. 371 Line494 Please explain further the kinematics between shoreline fault and San Luis Bay fault in transect C-C' 372 Line497 Figure 7-16. Why does ancestral Shoreline Fault have a dip? Please relationship with vertical Shoreline Fault. 373 Line 497 Figure 7-16 legend states faults are solid where well located -Are Edna C land Los Osos faults well located down to -30,000 feet? 374 Line 497 Figure 7-16. Please discuss constraints on dip between the range-bounding reverse faults and steeper strike-slip faults within the range for he structural model shown in Figure 7-16 as well as uncertainties. 375 Line 508 Presumably, the sensitivity analyses only include a range of depths that !are considered to be credible. Other values could have an impact on the tiazard. Consider adding the phrase, " ... not a hazard-sensitive parameter given the range of technically-defensible depths." 376 Line 511-513 h°his sentence is confusing. Perhaps it could be broken into parts or set pff with commas. 377 Line 515 'in" is repeated -please delete one. 378 Line 530 Please place a comma between "formations" and "which" for clarity. 379 Lines 531-532 'Uplift of the continental shelf region west of the Shoreline fault as ndicated by the presence of submerged marine terraces " Please provide any age information (e.g., MIS3?) 380 Line 536 Please explain further how the kinematics in the Southwest Boundary to the northwest of segments BR and BE engender the uplift rates land patterns shown in figure 7-4. 381 Line 538 If the phrase local seismic source zone" on this line means the same hing that "areal source zone" or Local Source Zone" means in Chapter 6, please use the appropriate one of those previously defined terms to IJrovide a consistent terminology throughout the report. If is means somethina else olease define it. 382 Line 540-541 Please discuss the constraints on the Wilmar Avenue fault being rooted nto the steeper Los Osos East (LE) fault. 383 Lines 542-543 How well are the fault intersections at depth known? Is it important to GMC? Please provide any insights possible. 384 Line 543 IA comma between "fault" and "assuming" would make this line clearer. 385 Line 567 Please check the caption of Figure 7 -17a. On the third line of the caption. "sinestral transpression" be changed to "sinistral transtension"? !Also please mention in the caption of Figure 7 -t 7b the reference number the transpressional reverse splay feature that is noted there. 386 Line 568 Figure 7-18. Southward dipping fault that intersects the Shoreline Fault at klepth is Dashed in Figure 7-18 and solid in Figure 7 -16 Please make 387 Lines 622-623 Why does the SLB faull increase to so* on cross section D -D'? Any t;onstraints? 388 Lines 641-642 The Los Osos East fault (LE) is characterized as an axial surface that (lips steeply to the southwest. " In panel B-B'. the Los Osos axial surface is not controlled by the change n dip of the controlling detachment and intersection of the San Luis Bay *ault -please explain location and driver of the "zone of defo1TT1ation" for he Los Osos axial surface. 389 Line 642 rrhe lelTTlinology "fold hinge" is used in the figure, but "axial surface" is used in the text. Please clarify. 390 Line 657 rThis would read more clearly as "San Luis Bay, Wilmar Avenue and Pceano faults). There is also an extra comma at the end. but inside the l'.larentheses 391 Line 668 $hould this be "fold" axis? 392 Line 682 $hould "OV" model be SW model? 393 Line 684-689 rrhis sentence is too long and could be improved for clarity. 394 Lines 729-734 Please move lines 773 -776 right after 734 so the reader knows why the kJips of the faults are different for the Edna block in A-A' in Figure 7-22 and Figure 7-26. 395 Line 747 Do you mean resolution? Regional constraints? Please K;larify. 396 Line 752 'The dip of the Los Osos fault is shown as 500 throughout the entire crust beneath the Irish Hills." It is shown as 60" in profile B-B' in Figure 7-26. 397 Line 780-781 Sierra Pampeanas is the Spanish spelling, Pampean Ranges is the English spelling -you have mixed the two. Please choose one. 398 Line 797-802 rThis statement is not germane to DCPP and is an incorrect interpretation. rrhey based this on a leveling line at the south end of the range where opography is actually low. and then apply the 1977 observed deformation o the highest part of the range. This results in a shortening rate that is an prder of magnitude higher than actually exists. It would be preferable to k.lelete this sentence as it adds nothing. 399 Line 824 rThis 1st sentence would read better if a couple words were added: '. .. subsequently been reactivated in the contemporary tectonic setting as transpressional system." 400 Lines 834-837 Uplift patterns in the SW portion of the Irish Hills (Figure 7 -4) northwest of $egments BR and BE (Figure 7-13) are difficult to explain in the OV model >-please expand the section to clarify the uplift boundary. 401 Figure 7-20 rThe massif names are lh Bogd and Baga Bogd (Big Bogd and Little Bogd). This spelling is different than in the text (see line 584). which uses he correct spelling. Please correct this figure to be consistent with the ext. CHAPTER 11 -Time Dependency Model 402 General Please review the chapter for notational consistency with Appendix. T1 for he forecast interval seems to be the same thing as To in Appendix. for 403 Line 8 rrhe first line is fuzzy in its meaning. Please improve the wording to mean what you are trying to say: "Recurrence models can be divided 'nto two categories, those that are time independent and those that are ime dependent. 404 Line 10 What has been described is not a Poisson distribution (which would the probability of n events occurring in a given time interval), but ather a Poisson process. Please use the more precise statement. 405 Line 12 Please consider adding a definition of the hazard function. or referring to Eq. 7 of the appendix for the definition. 406 Line 13 rrhis section discusses how time dependent models are considered but 11ot why. As noted, time independent models are typically used for site-PSHA purposes. Why is a time-dependent model being t;onsidered? Please provide additional discussion of the need for the of a time dependent model for faults and why the use of an Poisson rate is used, rather than a time-dependent PSHA. 407 Line 14 rrhis would be clearer if "models" was inserted after "most common" 408 Lines 20-21 rrhe statement "time-dependent recurrence distributions are more t;omplicated than the Poisson, implies that "Poisson" means "Poisson which does not make sense. If the intention is to compare the ime-dependent recurrence distributions with the exponential recurrence (which characterizes the Poisson process), please make that 409 Line 24 Might add something like. "particularly if there are other compelling easons for considering ii." If there was no physical basis for a time-model and no data upon which to base it. there would be no ustification for its use. 410 Line 25 rrhe phrase time-dependent fault recurrence" is incorrect. The ticcurrence of earthquakes can be time-dependent but faults don't recur pver time. Suggest removing "fault" or changing fault to "earthquake" 411 Line 26 'The SSC recognizes ... " The SSC is now sentient? Do you mean the "Tl h"eam recognizes ... "? Please clarify what you mean here. 412 Line 29 r-.'ou included time dependent recurrence or recurrence models? 413 Line 35 Might be useful to say that this is done via seismic moment rate to for rupture geometries. 414 Lines 38-39 h"he way it is described, the EPR appears to be a dimensionless ratio ("a that can be applied to the earthquake rate"). If this is a correct µnderstanding, please reconsider whether "Equivalent Poisson Rate" is an term, since the description in the text implies that it is not a ate at all, but a ratio of rates to be applied as a correction factor. If this is not a correct understanding, please make the actual definition of EPR 415 Line 42 Unlike other chapters. this chapter is written in the first person. Suggest µsing third person throughout the report. 416 Lines 42-43 'we review these data, and ranges of possible values where specific data 1>re not available." What does this mean -it is unclear what these data efer to when specific data are not available. Please clarify what you are ta. 417 Lines 48-49 Here it is staled that there are no data whereas earlier in the paragraph it s stated "limited data". Please clarify the intended meaning. 418 Line 55 Is there a hyphen missing in "site-to-source? 419 Line 57 'available data available" -extra word here? 420 Line 58 'slips per event" -do you mean "slip per event data"? Please clarify. Also riote that displacement per event" is used in other places in this chapter land in Appendix EPR. If the meaning is the same, please consider to maintain consistency of terminology. 421 Line 62-63 'A trench at the lngley site shows activity in the late Pleistocene" but then here is discussion of deformation (warping) in the past 2500 years and 1840 year-old deposits are faulted. These statements are incongruent. Please clarify. 422 Line 73-76 rThis is a summary of the interpretations and there needs to be better eferencing of the primary sources and/or sections of the report where the nterpretations were developed. 423 Line 75 Please check whether "displacements should be "displacements per and make any necessary correction. 424 Line 79 rThis last sentence could be improved for clarity of intended meaning 425 Line 83-84 'recurrence intervals between 265 and 2000 years, " sounds like there are multiple sites with abundant paleoseismic data. Do you really mean the on the recurrence interval falls in the range of 265-2000 yrs? 426 Line 89 'sample only the most recent few events" -do you really have the past *ew (i.e .* more than 2) earthquakes dated on the San Simeon fault and Los Osos faults? Please verify this statement. 427 Line 89 Not clear what "both" refers lo here. since there were multiple trenching along the Los Osos fault. Likewise. what are the "sites" are that are eferred to below in line 91 428 Lines 97-100 Is there a reason for specifying data types that currently don't exist? It the technical basis for the conclusions drawn 429 Line 99 'none of this sort" -are you referring to "this sort of data"? Please clarify 430 Line 108-112 rThese statements about the effects of early historical earthquakes are fine but they need context. Your basic argument is that there are early of significant magnitude that damaged some of the Spanish missions at significant distances. You need a concluding statement that $ummarizes this so that when you segue into the absence of such at the San Luis Obispo mission. it strikes home the argument that here have been no moderately large to large earthquakes affecting the egion since 1772. Also. note that the location of the 2nd large 1812 l:!arthquake (Dec. 22nd) is debated -Toppozada et al. (1981) place this the SAF but this is a hotly debated topic among those working on the and its affects (i.e. tsunami. which has been found in no direct and solid evidence found yet in paleoseismic at Frazier Mountain, although they pushed hard to make a t;ase, at first) 431 Line 120 Suggest adding "occurred" after larger. 432 Line 126 By saying that "it is likely that the local completeness level is actually ower, it sounds like less complete but you likely mean more complete. Please clarify. 433 Lines 127-129 What is the reason for the different weights? 434 Line 138 Please correct "cumulative density function" to read "cumulative function. 435 Lines 139-141 It is not clear that 0 is singular or plural, or what 0 actually signifies. This more explanation, and a good definition of E+. 436 Line 177 rThe correct statement is that the variate assumes only non-negative i.e., its support is the non-negative real line (the current wording mplies only that the distribution itself is non-negative, which is true but not nformative). 437 Line 185 Remove "is" 438 Line 186 Do you mean to say it doesn't depend on p as a mean parameter, or that 't doesn't depend on the mean of parameter f* '! 439 Line 192 In reference to the phrase "less than what Poisson rate, please specify hat the comparison is with the Poisson process that has the same long-erm mean recurrence rate that the given lognormal model has. if that is he intended meanina. 440 Line 193 Not sure what is meant by "anticipates". Please explain or choose a better word. 441 Line 194-195 'we do not know the times of the most recent events for any ... " Earlier, tyou laid out the paleoseismic data and discussed recency of faulting on he Los Osos fault (1840 rcYBP. line 72). and you discuss recurrence ntervals on the San Simeon fault (lines 84-85), which imply some nformation on past earthquake timing. Perhaps this lack of data needs lo be better explained earlier. and better summarized as it leaves the reader K;onfused as to what we know and what we don't know. 442 Line 196 If tMRE is treated as a random variable please state that explicitly. 443 Line 197 'The choice of functional form in time dependence is also unknown " As $lated, you are saying the "choice" is unknown. Please restate. 444 Line 211 'Coincides with the data estimale" is vague as lo whether the aperiodicity 's or is not the CV. If ii is the CV. please say so explicitly, if it is not, please what it means that it "coincides with the data estimate" of the CV yet is not the CV and why this distinction needs lo be made. 445 Line 212 Remove "wide" 446 Line 228 Please justify why the 3 time-dependent distributions plus the exponential are a reasonable representation of the center. body and range pf recurrence models. 447 Line 259 Please provide the technical justification for the DPE distribution in Figure 11-3, or provide a specific reference(s) (chapter or appendix. and $ubsection number) to the part of the report where the justification is kliscussed. 448 Line 260 Please state brieHy what is meanl by "faull distribution point" and give a reference to the sub-section of Chapter 8 where ii is defined ::however, a search of chapter 8 returns no match for "fault distribution point"). Allematively, if the meaning is just the 8.5, 50, and 91.5 IJercentiles from the CDF for Hosgri slip rate, please say so explicitly. In event, if there is to be a reference to Chapter 8 it should be made as to subsection (and perhaps figure number). 449 Line 271 It appears that the correct joint probability is that of L TM and tMRE. not L TM and S(tll TM) (in fact, the latter is a distribution. isn't it. not a random And joint probability of (l TM,tMRE) would be consistent with Figure 11-5. Please review and correct the text if necessary. 450 Line 272 Please provide further explanation of Figure 11-5. Are these plots to be 'nterpreted as joint probability density plots? If so. why does the area k.mder the function obviously exceed 1? Is each such joint probability ktensity function (if that is the correct interpretation) specific to a particular value? Some (not all) of this is cleared up after study of the !appendix material, but the explanation in this chapter needs to be self-K;ontained enough to be comprehensible without familiarity with the !appendix. 451 Line 274 Same comment as for Figure 8 of appendix: The horizontal axis in Figure labeled "Equivalenl Poisson Rate" (and EPR is indicated in the K;aption ). but the text seems lo indicate that this axis represents the andom variable CPR, not the estimated value EPR, and this nterpretation is reinforced by the fact that the plot is presumably showing he CDF of a random variable (i.e., CPR). Please review and modify as necessary to make the text and Figure 5 consistent, and to make clear lany conceptual distinction between CPR and EPR 452 Line 279 Please clarify the meaning of the phrase "relative to a Gaussian !approximation" in this context The Miller and Rice method minimizes misfits to the low-order moments by applying the moment-preserving IJroperties of Gaussian quadrature. In what sense can this be thought of las minimizing "relative to a Gaussian approximation"? 453 Line 286 Please provide discussion and/or references (to external documents or to eport section(s)) justifying thal the proposed CV weighting adequately epresents the center, body and range of lechnically defensible

• nteroretations. 454 Line 323 h'he verb "is" refers back to differences, which is plural. Please change to 'are" 455 Line 333 Please clarify the meaning of "less coherent as a source of hazard." 456 Line 336 $charer et al. (2014) does not appear in the list of references. 457 Line 347 Please review the appropriateness of the term "marginal distribution" in his context (and consider whether it makes sense to refer to a marginal opposed to a conditional distribution-as being 'conditioned on" a value of one of the variates). The text does not make that any variate has been marginalized, but rather seems to imply hat the initial joint PDF has been defined as delta(tMRE-To) x p(LTM). If he term "marginal distribution** is actually the correct one, please explain why .. 458 Line 349 rThe correct figure reference for displacement per event models appears to be 11-9 (not 11-8). Please check this. 459 Line 349 Please indicate (in both the text and figure caption) which recurrence model (lognormal, BPT. Weibull) is used in the construction of the results n Figure 11-9. 460 Line 351 $houldn't observation be plural? 461 Line 360-363 rThe explanation of the averaging is ambiguous and can only be worked tiut through reverse engineering from Table 11-3. Please rewrite to make t clear whether: ( 1) only SAF 1 is used in the final averaging; (2) a mean is taken for each of the three selected percentile points; Md (3) those means are weighted by 0.25, 0.5 and 0.25, for the 8.5, 50, 91.5 percentile cases, respectively, to form a final weighted mean EPR. 462 Line 362 Please give the rationale for the 0.25. 0.5, 0.25 weighting (referring to Miller and Rice if that is appropriate). 463 Lines 368-371 Please explain how the conditions (other than degree of hazard described here apply differently to the non-SAF regional faults han they do to the Primary (Hosgri. Los Osos, Shoreline, and San Luis Bay) faults. If there is no difference, justify why it is technically acceptable o not use an EPR for the regional faults even though it was found to be echnically required to do so for the Primary faults. If the sole justification s absence of hazard sensitivity, please review this passage and consider whether it could be better focused on the one relevant issue. 464 Line 371 Please provide reference(s) to studies that demonstrate the absence of tiazard sensitivity cited here. 465 Lines 384 Please clarify the sense in which the San Simeon event is less mechanically related to the Primary faults than the Landers rupture is to he Hector Mine faults. 466 Lines 396-399 Please indicate whether the Tl Team judges that the EPR model captures epistemic uncertainty to accommodate the absence of a reliable model for how large events influence the likelihood of subsequent events If so, provide the justification for that judgment. If not. please explain where that uncertainty is captured in the SSC model. 467 Line 403 IA comma is required between "'Farther afield" and '"EPRs" for clarity.

468 Line408 Please explain precisely (either here or in the paragraph beginning on Line 436) how the final values of EPR for the Hosgri and SLPB cases in Table 11-4 were obtained from the various estimates in Tables 11-1 and 11-2 (the corresponding calculation for SAF was explained in $ection 11.2.6). There is some explanation in the paragraph beginning on Line 436, but it is neither complete nor precise enough to enable the steps o be reproduced. 469 Line 427-429 rrhe in1ended meaning of this sen1ence is not clear. Please clarify. 470 Lines 430-432 rThere should be some recognition of what this approach means in terms pf the alternatives that are included in the values that comprise the tables. For example, what does this imply about relative defensibility of the ecurrence model functional forms? 471 Line 432-435 Please explain in what respect the range accounts for the fact that the EPR may not fully characterize all contributory factors. The range in the ables is wider than the range of the three branches. Isn't the range directly by discretizing the CDF obtained from the EPR analysis? 472 Line 438 Please clarify the meaning of "rounded across fault slip rate cases. 473 Line 455 Please clarify if 1his is seismic hazard. If so, the influence on hazard of any fault is a function not only of the effec1ive (EPR-adjusted) slip rate, noted, but the distance of the fault from the site. So large changes in he EPR for distant faults will result in small changes in the hazard. 474 Figure 11-3 rThe bottom panel has the same title as the upper panel, even though it is distribution of times, not displacements. Please correct title. 475 Figure 11-3 rThe box title and in the figure headers indicate displacement per event, l>ul in lhe text, you refer lo these as average displacement. Please clarify 'f these should be indicated as "average" displacements, both in the figure headers and box title. CHAPTER 12 -Regional Fault Sources 476 Lines 6-8 'Faults capable of producing moderate to large earthquakes that are not ncluded as Regional fault sources are represented by the areal source (Chapter 13)." Please move to end of paragraph after line 13. 477 Line 13 In place of (or in addition lo) the word small," please provide a statement of the relative hazard contribution from the regional *aults. 478 Lines 28-29 $ounds like a sales pitch rather than an accurate technical statement If he study is "comprehensive" why does it omit many faults? What is meant IJY "objective?" How can something be consistent with "all available data" when misfits are allowed to occur? Suggest toning down the description of UCERF3 to be more realistic and to specify that it provides a reasonable l>asis for characterizing some of the regional faults for the SSC model. 479 Line 34 Please consider citing an authoritative source such as a USGS report in $upport of the statement on this line 480 Line 35 rrexl moves back and forth belween first person and third person. Suggesl using lhird person throughout 481 Line 35 and 37 !Adapting (which implies changing them) or adopting (which does not imply 482 Line 39 rrhe quotation marks suggest that this is a quotation from some source. or hat the word itself. rather than its ordinary meaning, is the object of nterest. Please consider whether either of these is the case and edit (or riot) accordingly. 483 Line 58 Please specify that this is an assessment made by the Tl Team. 484 Lines 59-60 rrhe first clause of this sentence appears to have some sort of ranscription error. Please review and correct it. 485 Line 68 Where does this logic tree exist and who assigned the equal weights? 486 Line 72 'Figure 12-5 shows ruptures common to both" Is the top panel of Figure 12-5 intended to include faults common to both UCERF3.1 and 3.2 models? Presently, it is labeled Fault Model 3.1. 487 Line 85 'the depiction in this SSC model, while FM3.1 does not." Please consider deleling "depiclion in this" 488 Line 95 Suggest deleling "radial." 489 Line 113 'come nearer closer to the DCPP than the physical SAF itself." Please consider rephrasing to -come closer to the DCPP than the SAF. 490 Line 117 Please replace "we" with Tl team, if appropriate. 491 Line 216 Figure 12-4 indicates "Queenie fault". Is there a difference? 492 Line 244 !Are you suggesting juxtaposition of units of similar age that have different thicknesses? Please clarify. Otherwise, this could be 'nterpreled as growth slrata. 493 Lines 252-253 'Sorlien et al. (1999) note that the large amount of strike-slip inferred is j)ased on a regional tectonic model, and they discount the large offset. " Do Sorlien et al. (1999) provide an estimate of slip? 494 Line 262 Please consider changing "overlapped" by onlapped or draped 495 Line 290 What is the type of magnitude indicating 7.0? Ms? 496 Lines 301-302 It is understood that the characterization is simplified (i.e., single-valued). However. there is insufficient info1TT1ation in this section to understand how he values in Table 12-5 are derived. For example, the estimated slip rate wor the Queenie structure is said to be 0.005 mmfyr in section 12.6.1.2, but 0.1 mmfyr is shown in the table. The slip rates for the Santa Lucia Bank land West Basin -Southwest Channel faults are listed here at 1 mmfyr. Earlier, you cite a rate of 0.2 mmfyr since the Pliocene for the WB_SC *ault, which is likely a maximum as you state that much occurred toward he end of the early Pliocene. Slip rates for other faults shown in the table iare not discussed at all in the text. What approach was used? In the !absence of fault-specific info1TT1ation, drawing analogies to other faults is !appropriate, but must be indicated as such in the text. Likewise, what was he approach used to assess Mchar? It is not sufficient to merely indicate hat sensitivity analyses show these faults aren't important; that is dependent on the characteristics that are ascribed to the waults. If one of the faults had a slip rate of 30 mmfyr, the hazard $ignificance might be different. 497 Figure 12-3 Consider a way to name the fault sources -not everyone will be familiar with the California fault system. 498 Figure 12-7 Whal produces the sloping linear trends in seismicity rate between M6.5 land M7.5. These are interesting and should be explained in a caption ::which needs to be added to this and other figures). APPENDIX-Method For Estimating Time Dependent Fault Hazard in the Absence of an Earthquake Recurrence Record 499 Line 45 "Poisson probability distribution of ground rupturing earthquakes" is !ambiguous. Distribution of what? And, in fact, the Poisson distribution 'tself (probability of exactly n occurrences in a given time interval, as a *unction of n) is never used in the report. Please consider changing to a more precise statement (e.g., "the model of ground rupturing earthquakes las a Poisson process assumes that events occur randomly in time"). 500 Line 47 rrhis would be clearer if "to occur" is inserted between "more likely" and 'when the energy" 501 Lines 58-60 PSHA also initially did not consider the faults that gave rise to all seismic sources were source zones. each of which likely ncluded several faults. The point should be made early in this section that he whole time-dependent recurrence concept is for fault-specific ecurrence behavior. 502 Line 66 rrhe word "be" seems to be missing between "cannot" and "rigorously". 503 Lines 67-68 Consider indicating that an additional reason for the use of the Poisson model is that regulatory design criteria are expressed as target annual of exceedance (e.g., 10-4) without consideration of any lime klependence. 504 Lines 70-71 But, as you discuss below. the use of an equivalent Poisson rate does NOT require a change in the hazard code, just inclusion of the concept in he SSC model. Please clarify. 505 Line 97 'Cumulative density function is incorrect; please rewrite as "cumulative k!istribution function." 506 Line 162 rThe phrase "before reaching the long-term mean could be misinterpreled o mean that the CP ratio is asymptotic to the long-lem mean. which isn't the case. Please consider rephrasing to avoid ambiguity on this ooint. 507 Lines 166-167 you saying that we have absolutely no idea whal the value of these varameters might be? Or that we have no direct data upon which to base hem, but they can be estimated with considerable uncertainty? 508 Line 180 rThe phrase "although it coincides numerically with the data estimate of the more familiar coefficient of variation" seems unnecessarily cryptic. Since, nits role as a parameter in a PDF (Eqn 10). alpha is equal numerically to he CV, please clarify why it cannot simply be said to be the CV. 509 Lines 205-206 rThis statement is not always true for faults having good paleoseismic klata. Please qualify that this information is assumed to not be known for he faults in this exercise. 510 Line 210-211 The distribution conveys a relative agnosticism among choices in (lisplacement per event (DPE) from 1.5 meter to 3.5" Figure EPR-3 shows DPE from 1.5 -3. 511 Line 213 Up to 5.0 m in the text of the report (line 258, page 14 of chapter 11 ). Please check and rectify if different. 512 Lines 214-216 Please consider changing to the following (less fragmented) -In California, for example. the largest measured average slips per event K>n the San Andreas fault are 4.45 and 4.3 mlevent for the 1857 and 1906 respectively (Biasi et al., 2013). 513 Lines 218-22 rThe reference to an upper bound of 5 m/event in the text appears to with values up to 5.5 m/event given by the solid curve in Figure 3 ::there is a break in slope at 5.5 m in the plot, indicating a non-zero l'.lrobability point at that value of slip/event). Likewise. reference to an bound of 4 m/event in the text appears to conflict with values up to m/event for the dashed curve in the plot. Please check and make any required for consistency. 514 Line 227 If L TM is displacement per event divided by fault slip rate. then L TM must J:>e an inverse rupture rate (or mean recurrence time), not a rupture rate as Please check the text for consistency and correct as necessary. 515 Line 247 Please replace "to" with "do" 516 Line 265 If the reference to Philibosian et al is the same article listed in the eferences section, then it should be cited as 2011 (rather than 2012). Please check and make a correction if necessary. 517 Line 268 Since 1he EPR is a dimensionless ratio, not a rate, it would be clearer and ess subjecl to confusion to call it something else. Later the EPR is from the distribution of "conditional probability ratio (CPR)". erminology that explicitly indicates the dimensionless character. so calling EPR a rate and CPR a ratio is a source of confusion Please consider this point. 518 Line 275 Please replace "complimentary with "complementary." 519 Line 283 is needed after "renewal to set off the first part of this sentence. 520 Line 284 rrhe "IL TM" appears to be a typo-please check whether this should be 'LTM". 521 Line 286 It will cause confusion to say that the CPR is elevated relative to the Poisson rate, because the former is a dimensionless ratio and the later is an absolute rate (events/unit time). Please rephrase this to be more precise 522 Line 286 rrhe distinction between CPR and EPR is never stated explicitly, and this confusion later on. The eventual impression is that CPR is treated as a random variable and EPR its estimated value; if so, please consider making this explicit, and if not, please add text to clarify the mathematical/conceptual distinction between them. 523 Line 288 rrhe phrase declines to approach the Poisson rate at the upper probable ange of tMRE" may be misleading. First of all, since EPR is a ratio, $houldn't it approach unity if the CP approaches the Poisson probability? If so, please rephrase to make that clear. Secondly, the phrasing can be nterpreted to imply that the approach to the Poisson rate is an asymptotic l>ehavior. As that is in general not the case, please rewrite to avoid that *mpression. 524 Line 297 rrhe peak appears to occur below the diagonal in Figure 6, not above the kliagonal as stated. Please add clarification or correct the statement or Figure as necessary. 525 Line 303 rrhe term "joint probability surface" appears lo be used here lo denote a 'oint probability density. However. this is not made explicit, and doubt is aised by Figure 7. in which it is obvious that the integral under the surface s much greater than 1, ruling out its interpretation as a joint PDF. Further arises from Equation 13, as discussed in a subsequent K;omment. Please be explicit and precise about what is meant by "joint 1>robability surface." 526 Line 303 rrhe joint probability appears to depend upon slip rate If that is a correct nterpretation, please indicate (in the text and caption) what slip rate was to generate the probability function in Figure 7, and confirm that that rate plus the Hosgri OPE model of Figure 3 was the basis for the marginal distribution p(L TM) used to generate that figure (or if, that is *ncorrect, give the correct explanation). If the joint probability does not upon slip rate, please improve the description to make clear why riot. 527 Line 308 rrhe survivor function S(tMREIL TM) integrated over tMRE (for fixed L TM) snot generally unity. p(L TM), being a PDF, does integrate to unity. So W ntegrated over the tMRE,L TM plane is not generally unity. Therefore Wis not a joint probability density. yet the text gives the impression that it is 'ntended to be just that (though that interpretation is also cast in doubt by Figure 7, as noted in a previous comment). lfW is something other than a oint PDF, please explain clearly what it is. If W is a joint PDF, but the easoning in this comment to the contrary is incorrect, please clarify in the ext why there is no contradiction. Otherwise make necessary corrections that W can be properly considered to be a joint PDF. 528 Lines 313-15 rThis sentence seems correct, but ii is confusing because its intended l'.lurpose is unclear. Is it simply intended lo point oul that the variates IMRE and L TM are not independent (because the factor S in Eqn 13 depends not just on tMRE, but also on L TM). so that (by definition) the joint PDF is not simply the product of the marginal PDFs? Please rewrite or amplify to the intended meaning. 529 Line 320-32 t rThe horizonal axis in Figure 8 is labeled "Equivalent Poisson Rate" (and EPR is indicated in the caption). but the text seems to indicate that this axis represents lhe random variable CPR, nol the estimated value EPR, Md lhis interpretation is reinforced by lhe facl that the plot is presumably the CDF of a random variable (i.e., CPR). Please review and modify as necessary to make the text and Figure 8 consistent, and to make clear the conceptual distinction between CPR and EPR. The same K;omment applies to Figure 9. 530 Line 320-321 Since apparently the curve in Figure 8 is a CDF (or the complement of pne), its maximum value should be 1. This is not clear in Figure 8. If in fac he curve does rise rapidly to inlersect 1 al zero CPR (and from looking at Figure 9 ii becomes clear that it does), to avoid any confusion, please ndicate that fact with a modification to the figure or a note in the caption. 531 Line 335-336 Please explain the meaning of the vertical dashed lines in Figure 9. 532 Line 343 Please review the use of the term "marginal distribution" here. Wouldn't marginalizing on tMRE mean integrating over it, whereas what is l'.lroposed is concenlrating lhe tMRE dependence in a delta function to begin with. so W=p(LTM) x delta(tMRE-t_eqk)? In What sense is it lrue that "the equality constrain! is a form of marginal 533 Line 396 It is a little recursive to say that values of parameters used for Figure 12 were fixed to the values used in Figures 9-12. Please consider revising his. 534 Line407 Figure 13 has not been cited prior to this citation of Figure 14. Please whether the figure currently labeled 13 should be deleted and currently labeled 14 and 15 should be relabeled 13 and 14. If so, hen the citation at this point in the text should be Figure 13 (and figure citations are already correct). 535 Line426 would be useful between "principle" and "slip rale. 536 Line 456-457 Please explain the connection between the weighting method mplemented here and a maximum likelihood perspective. 537 Line 466-467 Please provide references for the cited MFD functional forms. 538 Figure 5 Please correct the following deficiencies in the figure: 1. The caption is inadequate. It should provide additional info1TT1ation, ncluding at least the CV used to generate the plots, the meaning of the circles in the upper right panel, and the meaning of the curve cutoffs n the lower panels. It should also properly indicate the nature of the are not all lognormal distributions. as the caption would even though they are all quantities derived from lognormal panels are called out by letter (e.g., Figure 5d) in the text, but hey are not labeled with those letters. 539 Figure 7 Please indicate in the caption what slip rate was used to generate this what DPE model was used ( Hosgri DPE model of Figure 3?), land what CV was assumed. 540 Figure 8 Please indicate in the caption the meaning of the red stars. 541 Figure 9 Please define the symbols, either in the legend or the caption or both, as well as stating the meaning of the vertical dashed lines (which do not to be mentioned in the text either). Please also improve the figure itle, which is rather cryptic (what does "Four Tmin,LN", mean, for Also please review the use of EPR for the title and horizontal !axis. and make changes as necessary to ensure consistency with the in the text and with any intended distinction between EPR and K;PR. 542 Figure 10 Please write a more complete caption for this figure. Is it based on the Hosgri DPE model? What are the dotted lines in the upper panel? Tmin is given in the legend, but not clearly identified there, so it also should brobably be given in the caption. 543 Figure 12 Please improve the caption. At the least, the meaning of the colors should Ile explained. 544 Figure 13 rThis figure may be redundant. Please check whether that is the case and if appropriate. 545 Figure 14 Please check whether this figure should be relabeled "Figure 13". 546 Figure 15 Please check whether this figure should be relabeled "Figure 14" and write a more informative caption (which should include deciphering "BWM"). Comment Location in Text Number 547 Line 5 548 Line 6 549 Line 8 550 Line 13 551 Lines 28-30 552 Line 37 553 Lines45-46 554 Line 49 555 Lines 57-58 556 Line 62-63 557 Lines 65-68 PPRP Comment Response Table Installment #3 PPRP Comment CHAPTER 9-Rupture Models "Historical ruptures have involved ..... Some historical ruptures? Many historical ruptures? Please clarify. "single fault zone" is referenced to the 1992 Landers earthquake, which actually involved 5 separate faults. Please clarify or correct. Using a colon after "styles of faulting" is change in style from earlier in the paragraph where the earthquake was in parentheses. Please make consistent for clarity of reading. "define fault rupture lengths" Do you mean to define potential rupture lengths? Define the potential for future rupture lengths? Define future potential ruoture lenoths? Please clarifv. Please state more explicitly the technical rationale for the choice to treat the rupture sources as aleatory variability. How is it different from a recurrence curve that expresses the aleatory variability in the magnitudes (and rupture dimensions) of possible earthquakes that occur on a fault source? Additional explanation is needed to understand the concept, the technical basis, and the implications to the SSC model. Also, there is an implication that epistemic uncertainties have not been included. It is recommended that the manner in which epistemic uncertainties were captured be identified here in juxtaposition with the statement that epistemic uncertainties are not included in the modeling of rupture sources. Plate 9-1. Please explain why the surface projection of dipping rupture source changes along strike for 75' dip, but appears more constant for 85' There is epistemic uncertainty regarding the slip rates. but how is slip rate itself treated as epistemic uncertainty. Please clarify your meaning. "A demonstration" or "demonstrations" ?? The fault names should all be followed by fault for clarity (Le .. Hosgri fault, Shoreline fault, etc.) Please clarify that the historical examples from Chapter 7 were possible analogues for each FGM, taken from other regions. Both here and Line 231, the declaration is made, without much technical basis. that the suite of rupture sources "captures the range of viable ruptures." How is this consistent with the SSHAC imperative to capture the CBR of the TDI? What is the basis for judging that the range is captured, especially since the approach of identifying specific rupture sources is different from the classic approach of defining recurrence curves for each fault source? It is noted that the range is considered adequate to capture the sources that contribute significantly to the hazard. Were there hazard sensitivity analyses conducted to support this Summary of Revisions to Report assertion? 558 Line 81 The descriptions of the respective rupture source types in Figure 9-1 differ significantly from the definitions given in Table 9-2. If the figure and table are intended to convey different types of information, please make that clear in the text and figure caption. In any event, please make sure that it is clear which characteristics are the defining characteristics of the rupture source types. and which just represent typical examples. 559 Line 84 Explain what defines the length of a characteristic rupture as being <100 km. There are many worldwide examples of longer "characteristic' ruptures. Are you saying the Hosgri fault only produces characteristic ruptures that are less than 100 km in length (-M7.2). Clearly later in the report, this is not the case. There needs to be some explanation as to why you broke out characteristic behavior to be limited to relatively short rupture seQments. 560 Line 96 Please replace comma with a semicolon after GMC model, 561 Line 105 Please consider some alternative way to describe "splay" rupture source type, because "overlapping source planes" is ambiguous (i.e .. in what sense do the planes overlap?). Branching of the rupture surface seems to be an important element. 562 Line 117 "Based on empirical observations" implies that there is a direct linkage between the observations and the topologies, and little judgment required by the Tl Team. Isn't it more accurate to say that the topologies are developed by the Tl Team based on a consideration of historical earthquake ruptures that may be analogous to the ruptures in the region? 563 Lines 119 and 130 Isn't down-dip hyphenated? 564 Line 123-125 The description of slip rates for complex and splay rupture sources is ambiguous. For example, if the intended meaning is that the primary part of a rupture source (complex or splay) has a uniform slip rate and the secondary part of the same rupture source has a different uniform slip rate, please make that clear. 565 Line 132 This sentence seems to be missing a verb. Please correct for clarity. 566 Line 138-141 The only stated exception to the obtuse angle requirement is the Hosgri-Shoreline splay. Please explain how the Los Osos-San Luis Bay splay is consistent with this taxonomy (i.e., why isn't it also considered an exceotion to the obtuse anale reauirement?}. 567 Line 143 The "three types of features" does not seem to include major steps or bends, although the majority of historical ruptures had endpoints at steps or bends. Was this intended? 568 Lines 156-162 Please include references to the corresponding figures from Chapter 6 on which the segment locations are shown. 569 Line 164-166 This sen1ence is confusingly wri1ten. because the subject is "ruptures [across branch points!" and the direct object is also "ruptures." Please rewrite to make it clear that it is the branch points themselves that may be the sites of rupture arrest more frequently than are generic fault points. 570 Lines 170-174 This seems to imply that more ruptures will include both the Hosgri and San Andreas faults. versus the Hosgri-San Gregorio fault where it meets the San Andreas fault. Is this what you intended to mean? Please clarify. 571 Lines 231-234 In defending this conclusion, perhaps the point should be made that the CBR is supported by the careful review of analogies and the fact that the salient elements of the rupture topologies are supported by observations that they have occurred elsewhere during actual earthquakes. Are there hazard sensitivity cases that show this? 572 Line 266 Please consider replacing "in which to where 573 Line 275 Please consider replacing "Although this result was considered by the Tl Team in developing the rupture sources. ,, with -Although the Tl Team considered this result when developing the ruoture sources," 574 Line 281 Figure 9-2 Please spell out RO and LH on figure 575 Line 284 Approximately 6 km in which direction? 576 Line 285 Kawafune? Is this a fault name? Please specify "fault" 577 Line 286 If both were reverse displacements, it would be clearer to say "opposite sense of vertical slip" 578 Line 305 General dip angle? Do you mean average dip angle? The general direction of dip? Please clarify. 579 Line 309 Stretches? Do you mean extends? 580 Line 310 Is M6.5 a large earthquake? Most seismologists would consider this a moderate event. Rather than using "large", you could say "surface-rupturing earthquakes" 581 Lines 315, 318 No fault section has been defined to indicate what "that section of the fault" refers to. Please clarify. 582 Line 325 You should also reference Sieh, 1996, as this was one of his examples to argue for the slip patch model. 583 Line 336 Subsurface rupture? 584 Line 341 "bordered the flank" Do you mean bordered" or flanked". This statement is unclear, as written. 585 Lines 341-342 Are you referring to rupture of the Brawley fault? Please clarify this 586 Line 344 Please consider deleting "instruments". 587 Line 359 Please change "Displacement on" to displacement in 588 Line 365 "several major and many right-lateral faults"? Consider deleting "and many" or qualify as "many minor" 589 Line 367 Geodetic strain needs more clarity of meaning. Wasn't the geodetic strain fairly localized? 590 Line 369 Does a 30 degree change in strike count as sub-parallel?? 591 Lines 372-373 This is somewhat misleading and semantic. The Landers/Kickapoo fault is essentially co-linear with the southern section of the Johnson Valley fault (which wasn't recognized prior to the 1992 earthquake). Basically, the Landers and southern JVF are the same fault. The rupture stalled 592 Lines 375-376 593 Lines 378-380 594 Line 385 595 Line 386 596 Line 395, Figure 9-6 597 Lines 407 -408 598 Lines 412-413 599 Line 417 600 Lines 424-425 for 7 seconds at the intersection with the Homestead Valley fault, and then re-nucleated on the HVF to continue the rupture. Two major e11ents. See figure below. Valley Fault \ ,/?'tt-. '-:. \ . *iii.*'. Kickaooo fault ..* ,. . ....... ,_. ....,.,,.. --)\ ".'-.. \. *1 \ ... "" * .... ,, * .. HomesteadVaUey Fault -:"":. .,-. The step from the Emerson fault to the Camp Rock fault is not contractional -it is also a releasing step. Please provide references for estimates of stress drop and the relationship between stress drop and recurrence intervals (e.g., Rockwell et al., 2000) Please add year (2012) to Madden and Pollard. Please change "to better resolve" to to resolve better. Please explain "culled measurements" Angle of the prestress? Or just the fact that the main Denali was stressed whereas the eastern Denali was not, probably due to a recent failure. Please clarifv What is meant here? Most faults were previously mapped and named (Barnard, 1965). Are you just saying that it wasn't known that they would rupture together? In the same sense, the 1992 Landers earthquake identified a previously unknown fault system, and the southern Johnson Valley fault was not known in the literature. Please clarify. "Previously unidentified fault system" is an accurate quote from the study of Fletcher et al. However, many of the individual faults involved in that rupture were known and mapped beforehand. Please consider adding a few words to clarifv this point. Check this. There was a foreshock on a north-striking normal fault, but the mainshock initiated on a northwest-striking fault -the Laguna Salada fault. Please consider, given the uncertainties, whether a less categorical statement would be more aooropriate. Please clarify reversal in slip. This could mean normal to reverse. Right-lateral to left-lateral What you mean is that the dip direction switched from SW in the southern half to NE in the northern half of the rupture? 601 Line 429 Series of several?? Please clarify. 602 Line 447, Plale 9-1 Is HB vertical? If so, the surface projection of dipping rupture source (pink) slops south of HB. If correct, please state on plate 9-1 or in text. 603 Line 456 The phrase "uncertainty in the distance" could be understood to suggesl lhat it represents epistemic uncertainty. The way lhe model is employed, lhat does not appear to be the case, but rather that all of lhe Hosgri rupture sources occur on any one branch of the logic tree, so that the rupture sources collectively define aleatory variability. If the latter is the correct interpretation. please consider adding some clarification that it is actually aleatory variability in future rupture distances that is modeled by lhe device described here. 604 Lines 457 -459 Please add -with different dips -to the end of the sentence below "These sources are identical in length. extending from the south end of the Hosgri fault to the MT J, but they occupy different strands of the fault zone directly west of the DCPP. " 605 Line 4 71, Table 9-3 Please consider adding subscript to H-01 (75), H-02 (85), and H03 (90) in he table 606 Line 471 Table 9-3 How about just a section of the Hosgri fault as a characteristic rupture? Is this scenario accounted for in one of the models? Please clarify how shorter Hosgri fault ruptures are accommodated by this model as this seems to be the most likely scenario and it is not clearly presented. 607 Lines 476-486 Models H-01, H-02, and H-03 are essentially the same except for the site to source distance. In reality, they may all fail together as a broad zone -is that scenario in lhe model?? 608 Line 499 Consider changing analogy to analogous. 609 Line 502 "recent 20 dynamic ... " Define recenl". 2003 is 12 years old. Please clarify. 610 Lines 502-507 Please consider shortening sentence or breaking inlo parts. 611 Line 538, Table 9-4 Please explain why SH is secondary and BE+ BR are primary in OV-03 -this makes sense for the SW model but not for the OV -is it driven by slip rate? 612 Line 546 Consider rephrasing -"The south end the rupture source is the south end of the Shoreline fault source-the intersection with the Casmalia fault." to The south end of the Shoreline fault source at the intersection with the Casmalia fault is the south end of the rupture source. 613 Line 582 Figure 7-2 should be Figure 7-4? 614 Line 596 This would read more clearly if "an" was placed before "oppositely" 615 Line 605 Please explain why some ruptures continue to the MT J and some end at the north end of the San Gregorio fault. 616 Lines 630. 634 It is slaled here that SW-01 through SW-03 "acknowledge uncertainty" in whether the set of faults rupture together, but that SW-04 through SW-07 "describe variability" in ruptures on another set of faults. This contrast in language could leave the impression that one treatment is epistemic and the other aleatory, whereas it appears that the SSC model is set up to treat both as aleatory variability. If that is the correct interpretation, please consider using more consistent language to highlights that fact. If lhat is not the correcl interpretation, please clarify. 617 Line 661 Recent work has shown a strong strike-slip component on the Little Pine fault (Cannon, 2012) 618 Line 673 and 684 Figure 7-2 should be Figure 7-4? 619 Line 689 This is word-for-word the same as in the previous section -needs an "an" before "oppositely" for clarity. 620 Line 690 No comma is needed after California 621 Line 697 This would read more clearly with "that between "SWBZ and "could" 622 Line 703 You need a period at the end of the sentence 623 Lines 729. 730 Commas are not needed after "California or "Japan". 624 Line 734 This would read more clearly if you replaced "Like" with "As with" 625 Table 9-6 Please spell out Avenue for Wilmar Avenue fault, as it is a formal name. 626 Lines 740-749 Table This is another case where the switch in language from "uncertainty" to 9-61Plate 9-2. "variability" is a potential point of confusion. Please consider using consistent language to keep it clear that the range of rupture sources (within a given Rupture Model) represents aleatory variability. 627 Line 750 Please explain -LB and LE dip south -why is surface projection of rupture to the north? 628 Line 806 If rupture source NE-11 models "the possibility that the Morro Bay basin does not represent a step-over." doesn't this represent at least some conflation of epistemic and aleatory elements in the SSC model? That is. "represents a stepover" and "does not represent a step-over" are, on the face of it, mutually exclusive alternatives, so represent epistemic uncertainty. Yet they appear to occur concurrently in the NE logic tree branch. Please explain why this is not a contradiction. 629 Line 818 Please explain surface projection change along segments NL and FN in NE-07 (Splay) 630 Line 834 This results in faults that do not intersect at depth unless the Hosgri ruptures south of the intersection. 631 Line 851 Please remind the reader of what the first piece was. 632 Line 852 It would help the reader to remind them that the slip rate allocation will ultimately provide information related to earthquake recurrence rates 633 Line 880 If this feature (greater slip rate) is merely the definition of primary," please make that clear (otherwise it is ambiguous, because there is the alternative that "primary** has been defined on some other criteria and then this sentence becomes a rule about assigning relative slip rates). 634 Line 881-882 The slip rate should be greater by an amount proportional to the ratio momentfarea of each part (not the moment alone). Please correct this statement (although it is cleared up in the subsequent equations) 635 Line 891 Units should be specified here (e.g., the seismic moment given by Eq. 9-4 is in dyne-cm) 636 Line 97 4-977 This sentence is confusing. The first clause appears to be just a partial restatement of a more precise statement in the second clause. Please rewrite to improve clarity. 637 Line 1006 Please state the criteria that were used to conclude that the fits were satisfactory. 638 Line 1022 Table 9-8 As 89% of the rate is on the H-01, H-02, and H-03 models, does this imply that these ruptures extend all of the way to the MTJ? This is not entirely clear, as presented. 639 Line 1046 There are eight Hosgri rupture sources. If the reference on this line to "the five Hosgri rupture sources" is meant to refer only to those that rupture the Hosgri Fault Source, please indicate that, and in any event olease clarifv the statement. 640 Line 1048 Table 9-9. It is 54% not 65% as stated in Explanation column H-01 (Central strand) 641 Lines 1055-1058 If the location is aleatory, then the relative frequency of each location must be defined by the Tl Team. Please inform the reader how the relative frequencies (fractions) were assessed by the Tl Team. What types of data were considered? What was the role of different types of data (e.g., geomorphic expression. analogs, indications of vertical component of slip)? The reader needs to know that this is an expert assessment process (i.e., the numbers don't just fall out of the calculations), but the expert judgments are informed by a variety of data constraints. 642 Line 1062 Please consider replacing "not as continuous a trace" with -a discontinuous trace 643 Lines 1064-1067 What if one or more strands were more strongly strike-slip (i.e., different horiz/vert ratios)? How does this compare with the offset channel data from LESS Lines 1215-1216? 644 Line 1077 'The plant" is elsewhere called "the DCPP." Please consider keeping the terminology consistent. 645 Line 1077 Please consider adding two letter segment after "western reach of the Hosgri fault source' (HB) so ii not confused with HW 646 Line 1087 If "relative merits of this configuration compared to others" means compared to other options for filling in the limited Shoreline Fault slip budget. please add that clarification. Otherwise, add some explanation o1 what the phrase means in this context. 647 Line 1090 It would be useful to explain the difference between the 54% allocation and the approximately 65% estimated based on vertical separation. Please explain why these values are not in conflict with each other. 648 Line 1097 The Hosgri slip rate CDF seems to have been presented in Section 8.3.7 (not 8.3.3). Please check and correct if necessary. Also please explain why the Hosgri slip rate CDF shown as a solid black curve in Figure 9-9 is called a "discrete Hosgri CDF" when it appears in the figure to be a continuous function. and seems to be presented as a continuous CDF in Section 8.3.7 (e.g., Figure 8.3-20). In what sense is it discrete" (that term would seem more appropriate for the logic-tree CDF, and the term is used in that sense on Line 1101 )? 649 Line 1099 Please replace "it is a satisfactory with "it provided a satisfactory." 650 Lines 1101-1102, The phrase "discrete CDF of all logic tree branch combinations and their Lines 1165-1166, and weights" is not clear. Please clarify (e.g., it would be clearer to say Lines 1243-1244 something like "discrete GDF of all weighted logic tree branch combinations" if that is the intended meaning) 651 Line 1130 It is understood that the "preferences" identified in this paragraph and the next two paragraphs are implementing the two principal bases for the allocation discussed in the paragraph starting with Line 936. However. the reader needs to have a better idea of how the application of the bases is applied in each case discussed in these three paragraphs. For example. why does the Tl Team have a preference that the Shoreline fault slips either along or as part of the Hosgri fault? Is it the least complex topology for accommodating slip? More consistent with analogs? Likewise. in the next paragraph, why is 92% allocated to reverse-only rupture sources? The technical bases for the allocation amounts need to be given. especially because they are based on expert judgments. It is comparable to providing technical justification for the weights assigned to logic tree branches: there needs to be some basis given in the text or the decision will look arbitrary. 652 Lines 1134-1136 Please consider changing sentence to: The remaining slip rate is allocated approximately evenly between the shorter (OV-03) and longer (OV-04) complex ruptures whereby the Shoreline fault source ruptures as part of multi-fault complex rupture involving both strike-slip motion and reverse or reverse obliaue motion. 653 Line 1161 Figure 9-Why is OV-05 at the top of the list in the legend? 10 654 Line 1173 For clarity, spell out numbers in this paragraph as the get lost with the other numbers. 655 Line 1185 H-05 -This should be 23% of Shoreline fault slip budget and then table for the SW model will sum to 100% 656 Line 1185 Please explain -SW-06 source of 0. 086 is 100% of total budget for Los Osos source, but is listed at 45% 657 Lines 1215-1216 0.09 mm/yr is not 45% of 1.9 mm/yr. it is 4.5%. Is there a typo here? Please clarify. 658 Line 1215 "The total slip rate of less than 0.09 mm/yr is approximately 45% of the geologic rate of slip of 1.9 mm/yr attributed to the Los Osos fault in the SW Model (Section 8.5)." Total is listed as 0.09 for Los Osos in Table 9-13 -please make consistent 659 Line 1217-1220, and Please expand the technical argument supporting the 0.45 coupling 1290-1297 coefficient for the Los Osos Fault in the SW model, and the 0.57 coefficient for the San Luis Bay Fault in the NE model, especially any empirical support. For example, if there are geologic analogues that favor decoupling of approximately this magnitude. please cite. If this value is a source of significant hazard sensitivity, please explain how the SSC model accounts for uncertainties in the coupling coefficient. If it is not a source of significant hazard sensitivity, please state that and cite the hazard sensitivity analysis that establishes that fact 660 Line 1220 Field el al.,2014, does not appear in the list of references. 661 Lines 1251-1256 Spell out numbers in this paragraph as well, for clarity. 662 Line 1290 "Combined, these rupture sources accommodate approximately 0.09 mm/yr of seismogenic slip rale on the fault, or approximately 57% of the total 0.16 mm/yr slip rate attributed to the San Luis Bay fault in the NE Model (Table 9-15; Section 8.6)." Allocated 0.092 total slip for San Luis Bay Fault in Table 9-15 not 0.16 mm/yr -please make consistent. 663 Lines 1313-1314 Consider including the slip rate CDF information in a caption or the notes for each of these types of figures. 664 Line 1333 Table 9-Hosgri +SW Models and Hosgri +NE models do not add up lo 100% as 17. shown in Table 9-17. 665 Line 1356 Mighl want to add supporting arguments why lhis higher-than-target slip rate on the Hosgri faull north of the DCPP will not meaningfully affect the hazard results for the DCPP. 666 Lines 1406, 1473, Please complete these citalions. and 1477 667 Table 9-t7 Please clarify why the western reach of the Hosgri fault has a negative slip rate. Cross-check lhis with lines 1344-1345 and clarify what/how it was done. 668 Figure 9-2 Is it really negative vertical offse!? Subsidence? Plus. technically, offset is a strike-slip term. 669 Figure 9-3 The arrow showing lhe northern exlent of rupture in Yeats' figure is misleading, as both the 1940 and 1979 ruptures extended north of this point. 670 Figure 9-7 The note on the figure states that two dominant fault zones are shown by thick black lines. It is confusing that, for the most part, these black lines are covered by green or yellow lines showing other attributes (also true in Flelcher et al.'s published version). Please clarify this issue in the fioure note. 671 Figure 9-11 An explanation is needed with lhe figure that the individual rupture source CDFs sum lo the Lognormal SLB GDF 672 Figure 9-9 through 9-The Hosgri slip rate CDF (solid black curve) in panels a and c of Figure 14 9-9 is labeled "Discrete Hosgri CDF." But it appears to be a continuous CDF, and that is also the impression left by Section 8.3.7. Please clarify or correct the figure label. Same comment applies to the CDF plots for other faults in Figures 9-10. 9-11, 9-12, 9-13, and 9-14. CHAPTER 10-Magnitude Distribution Models 673 Line 7 lsn*t the shape actually defined by the magnitude PDF, while the MFD actually incorporates the seismic moment rate? 674 Line 40 Might qualify this statement to indicate "earthquake magnitudes that give rise to significant ground motions." It might be argued that the historical/instrumental record provides a pretty good basis for assessing the rates of M3 earthquakes. 675 Line 50 Table 10-1 Within the WAACY box, doubly-tuncated should read doubly-truncated. 676 Line 61-62 Please state what lengths would typically be hypothesized to be characteristic, and provide justification or a reference that does so. Or, if that discussion is provided elsewhere in the report, please provide a specific (chapter, section number) reference. 677 Line 79 This sentence appears to be a direct contradiction of sentence beginning on line 520. Please rectify this apparent contradiction or explain why it is not actually contradictory. 678 Line 84 Here and elsewhere in the text. this should be termed the "characteristic earthquake model". 679 Line 97-98 Please improve this explanation of conditions for use of the characteristic PDF. because the explanation seems more or less circular without a quantitative statement of the rupture-source length criterion. 680 Line 104 The word .. but" is a source of confusion. because it suggests that the second clause is going to qualify the first, whereas the second clause actually seems to directly reinforce the first. Please check whether the intent of the sentence would be more efficiently communicated if the word were chanqed to "and." 681 Line 127 And what are the disadvantages? (difficulties in assessing the various parameters?) 682 Line 150-151 The phrase "the logic tree ofWAACY parameters values and weights are correlated with" is unclear (e.g., does it mean "the parameters values and weights in the logic tree are correlated with"?). Please rewrite the sentence to clarify its intended meaning. 683 Line 154 Suggest a section title that is more specific to Mchar and Mmax. otherwise, the section could refer to the selection of the particular type of magnitude to be used (Mw, Ms, etc.). 684 Line 183 Check spelling on paleoseismic. 685 Line 197 Please consider rephrasing -This prediction is supported to an extent by empirical data. which include no step-overs wider than 4 km (Wesnousky, 2008) or 5 km (Lettis et al., 2002), but not in detail, as Wesnousky (2008) found that among step-overs less than 4 km wide, there was no relationship between step-over width and likelihood of arresting rupture. 686 Line 204 The phrase "energy in rupture momentum" is not physically meaningful. In fact, at least in the limit of a very narrow process zone, a rupture front does not carry any momentum at all, in the sense that rupture speed can respond instantaneously to changes in stress, frictional resistance, etc. Please substitute more appropriate language. 687 Line 208 Soften -replace indicate with suggest 688 Line 208 This would read more clearly with a comma after "lengths". 689 Line 212 "where fault traces more abruptly bend" would read more clearly as "bend more abruptly". 690 Line 214 Please consider replacing "than where they are less pronounced" with "where offsets or bends are more pronounced" 691 Line 222-223 "The maximum M,.,., value for all Primary fault sources bypasses essentially all proposed segment boundaries." Are these wall to wall ruotures? Please exolain 692 Line 239 Please change "materially" to substantially -remove any material properties confusion 693 Line 247 Replace "Points" with Features 694 Line 286 Please check for missing verb on this line. 695 Line 287 Delete "and" between intersection and had for clarity 696 Line 296 consider replacing "considered lesser in degree" with "less well developed" 697 Line 300 This line is unclear. What are alternates? Please check whether the word "alternatives" (rather than "alternates") better corresponds to the inlended meaning on this line. Or is it allernalive traces? 698 Line 303 Faults joining? The activily of faulls that inlersect the main trace is low?? Please clarify. 699 Line 307 Replace "short" wilh finile 700 Line 314 Please make it clearer whal is meant by "to define the limils of soft segment boundaries along fault sources:* 701 Line 330 Please insert caplure in front of magnitude 702 Line 330 Please check whether the word "given** (rather than "provided") would better convey the intended meaning. 703 Lines 333-336 The range of magnitudes predicted by the allemative rupture lengths considered using any single magnitude-scaling relation is much greater than the range of magnitudes predicted for any single rupture length (or area) from a suite of magnitude-scaling relations. This sentence is difficult to parse. Please rewrite and clarify this statement. 704 Line 340 Delete extra "do" for clarity. 705 Line 340 Please explain why the SSC forward-modeling approach implies weaker sensitivity to magnitude-area scaling compared with the inversion approach of UCERF3. 706 Line 347 "This review included other evaluations of alternative scaling relalions and their relative merits for use in seismic hazard analysis (e.g., WGCEP. 2003; Shaw. 2013a: Stirling et al. 2013)." Redundant -please remove. 707 Line 360 Use a comma after SSC model, rather than a colon. 708 Line 361 "strike-slip Hosgri fault. lesser but significant" is unclear. Perhaps insert "whereas" before lesser? 709 Lines 367, 368, 369 Abbreviated HB02 -please add "as" so it reads "abbreviated as HB02" 710 Line 370 Abbreviated as??? How is this designated? 711 Line 376 EB02 should be EB03? 712 Lines 378-380 HB08 data set looks more comparable with YM11 than NGA-W2 data set? 713 Line 385 EB02 should be EB03? 714 Line 438 Here you use a 12 km depth for characteristic ruptures, but the implicit assumption is that these only apply to shorter faults, and not the Hosgri. Perhaps it would be good to make this clarification here rather than below (lines 451-453) 715 Line 447-450 The argument in this sentence appears to be that it is acceptable to under-represent aleatory variability of magnitude because epistemic uncertainty is broadly sampled. Please justify quantitatively why this tradeoff is acceptable (for example, this might be done by referencing available hazard sensitivity analysis). 716 Lines 451-455 Please provide supporting evidence for the stated hypothesis that only the largest earthquakes rupture with depth greater than the depth limits inferred from background microseismicity. 717 Line 454 The wording "depth of crust derived from proxies such as the D90 or D95 values** implies incorrectly that D90 or D95 can be interpreted as proxies for the depth of the crust. They are proxies for depth of the seismogenic zone, and perhaps for the brittle-ductile transition depth Please make appropriate changes. 718 Line 458 Please state the technical justification for selecting M 7.3 as the threshold for rupture deeper than 12 km. 719 Line 468 The figure uses 130 km. Please make consistent. 720 Lines 471-474 This aleatory variability is considered by the Tl T earn to represent a combination of magnitude variability given the rupture area and rupture area variability of the characteristic earthquake given the approximate definitions of the soft segmentation points used to define the characteristic ruptures. Please rewrite this with one less "given, as it is difficult to parse. 721 Line 480 Don't capitalize "The" 722 Lines 485-489 This sentence is confusing -please rewrite for clarity 723 Line 490 Was any consideration given to the manner in which the exponential relationship would need to be implemented? Studies of other active faults show that the observed seismicity occurring within a narrow zone along a fault is not compatible with the exponential shape of the recurrence curve unless a very large Mmax is adopted (e.g., Hecker et al. 2013). Was there any attempt to examine the recurrence distribution along the Hosgri fault or other faults based on seismicity? The same arguments made below between the exponential and WAACY model with respect to repeated slip at a point could be made here to justify the zero weighting of the exponential model for Category A rupture sources. 724 Line 500 130 km in the figures -please correct to a common value. 725 Line 504 Please consider whether the challenges to the exponential PDF identified by UCERF3 (Field et al., 2014) constitute another factor (in addition to the Hecker et al analysis) in the Tl Team's judgment to give that PDF substantially lower weight than given the WAACY PDF. 726 Line 504 Please insert paleoseismic before data 727 Line 506 Replace "confidence" with determined 728 Line 509 The inclusion of Figure 10-5 with virtually no accompanying explanation in the text or caption is extremely confusing. The figure makes reference to undefined "Group A," Group B". and Group C". and the reader naturally associates these with the "Category A," "Category B," and "Category C" magnitude PDF categories that have just been introduced in the text at this point (only to eventually discover that there is no such connection). Please either make some use of the figure, with a full explanation, or delete it. 729 Line 514 Please define "available data "There is an implication that these endorsements of the exponential distribution for faults were made after giving due consideration of the Hecker et al. data regarding slip per event. What types of data were considered by these authors and is it possible that they would endorse the WAACY model over the exponential model if they had considered all "available data" presented by Hecker et al.? 730 Lines 516-517 A potential criticism of the maximum magnitude model for hazard analysis is that smaller magnitudes are not provided for in the distribution for each rupture source It could be noted that the use of the model in conjunction with seismic source zones to account for smaller magnitude seismicity ensures that all magnitudes smaller than the maximum are included. 731 Line 520-522 The statement about Category C rupture sources is that "aleatory magnitude variability is introduced by involving more than one scenario with defined relative frequencies. But Line 79, also in regard to Category C rupture sources, states that "epistemic uncertainty is incorporated by considering alternative scenario earthquakes." Please explain why this is not a contradiction, or make changes to provide a consistent description of the intended treatment of variability in the Cateaorv C rupture sources. 732 Line 536 Insert model after UCERF3 733 Line 557 "at random" may read better as "randomly" 734 Line 568 "the left end?? Left end of what? One end? South or north end? There is no "left" or right ends of a fault without a reference frame. 735 Line 570 Same comment. "on the right" could read "towards one end" 736 Line 572 "of 60 km long" -this would be clearer with a hyphon between km and long 737 Line 574 Please write text and one or more equations explaining precisely what quantity is plotted in Figure 10-6 and how that quantity is applied to the magnitude PDFs (e.g., what is a "reduction rate-the term "rate" implies it has units, yet from the range of values in the plot, it appears to be dimensionless; assuming it is actually a dimensionless adjustment factor, what quantity does it multiply to implement that adjustment? How do you go from the curve in Figure 10-6 to the results in Figure 10-7; how does the quantity in Fiaure 10-6 combine with the factor LIL.?). 738 Line 584 Please give a precise definition of "geometric reduction" and how this term is distinguished from. and related to, the terms "rate reduction" labeling the axis in Figure 10-6 and reduction rate" introduced on Line 574. 739 Line 592 It is stated on this line that the exponential model leads to a point MFD that has a "gentle upward deflection" for larger magnitudes. There is no upward denection on the point MFD (blue) curve in Figure 10-7a (nor is it clear why one would be expected). Please clarify 740 Line611 Please explain the phrase "arithmetic sum by magnitude" 741 Line 623-624 Please check whether the phrase "alternative earthquake scenario magnitudes and frequencies for complex and splay rupture sources" actually communicates what is intended. If so, please explain how alternative" scenarios can be reconciled with the sentence beginning on Line 520 that says Aleatory magnitude variability is introduced by involving more than one scenario earthquake pair, whereby the relative frequency of the scenario earthquake pair is defined. The scenarios are either "alternatives" or they occur collectively with some "relative freauencv," and it is not clear how both statements can be correct. 742 Lines 636-637 Figure 10-4 shows 130 km as the break between category A and B rupture sources. 743 Line 653 It is not clear what is meant by "alternative aleatory logic tree branch values." Table 10-5 refers to "scenario frequency," suggesting that all of the listed scenarios occur on a single logic-tree branch and represent aleatory variability, not mutually exclusive alternatives. So please explain what the alternative" logic tree branches are in reference to Table 10-5 The confusion about the status of the Category C rupture sources seems to be systemic in this chapter: Note the related apparent contradiction between sentences beginning on Line 79 and Line 520, and the related issue on Line 689 (with reference to Table 10-8) and Line 722 (with reference to Table 10-11) 744 Line 655 Please explain how the assessment of the relative frequency of the scenarios relates to the shapes of the MFDs. What was the thought process used by the Team? 745 Line 658 "favors" instead of "favored"? 746 Line 670-71 Same as comment for Line 623: Please check whether the phrase "alternative earthquake scenario magnitudes and frequencies for complex and splay rupture sources" actually communicates what is intended. If so, please explain how "alternative" scenarios can be reconciled with the sentence beginning on Line 520 that says "Aleatory magnitude variability is introduced by involving more than one scenario earthquake pair. whereby the relative frequency of the scenario earthquake pair is defined." The scenarios are either "alternatives" or they occur collectively with some "relative frequency," and it is not clear how both statements can be correct. 747 Lines 672-673 It would be helpful to indicate where on the figures these segment boundaries can be found. Perhaps add a column to the table what makes reference to the applicable fiaure. 748 Line 674, Table 10-6. Why is LC. HN, HD not a tier 1 as there is observed a pronounced difference in sense and rate of slip between the two faults? 749 Table 10-6 "South end of Little Pine fault"?? This fault strikes southeast -please correct the strike. 750 Table 10-6, LO, LE Different slip rate or difference in slip rate?? Please fix. box. 751 Line 677 Only double asterisk for SE"" 752 Line 687, Table 10-7 Suggest including "Rupture Source Magnitude PDF Category" (rather than just "Category") in this heading to remind the reader. 753 Line 687, Table 10-7 Please provide some discussion of how the weights for Mchar and Mmax were assessed. 754 Line 689 Same comment as for Line 653: It is not clear what is meant by "alternative aleatory logic tree branch values," given that Table 10-8 appears to describe relative frequencies, not mutually exclusive alternative models. Please explain how to interpret Table 10-8 in terms of alternative logic tree branches. and how that is consistent with the aleatorv nature of the variabilitv imolied bv the term "relative freauencv." 755 Line 700 This would read more clearly with a comma after "sources". 756 Line 702-703 Same as comment for Lines 623 and 670: Please check whether the phrase alternative earthquake scenario magnitudes and frequencies for complex and splay rupture sources" actually communicates what is intended. If so, please explain how alternative" scenarios can be reconciled with the sentence beginning on Line 520 that says Aleatory magnitude variability is introduced by involving more than one scenario earthquake pair. whereby the relative frequency of the scenario earthquake pair is defined." The scenarios are either "alternatives" or they occur collectively with some "relative frequency, and it is not clear how both statements can be correct 757 Table 10-9, SE** box "Postulated South end" -south should be lower case. Also, shouldn't this be southeast end, as the fault strikes NW-SE?? This comment also applies to other tables with identical verbaQe, such as Table 10-12 758 Table 10-9, LP box Same comment as above -the Little Pine fault has a NW-SE strike. so this should read the southeast end. This comment also applies to other tables that use identical verbage, as in Table 10-12 759 Table 10-9 SH-HB marked difference in slip rate -Tier one? 760 Table 10-11, SW-04 The hazard implications of the M8 scenario that includes the Hosgri will box need to be considered in Chapter 14. In particular. the implications of assianina a 10% relative freauencv should be discussed. 761 Table 10-12, SA box Fault is capitalized here. and small case elsewhere. Be consistent 762 Table 10-12, WB, SS, Please add fault after Wilmar Avenue, for clarity. SF box 763 Line 713 There isn't any "description" provided in the table. 764 Line 717 Figure 10-Please explain surface projection pattern for NL? 30. 765 Line 722 Same comment as for Lines 653 and 689: It is not clear what is meant by alternative aleatory logic tree branch values," given that Table 10-11 appears to describe relative frequencies, not mutually exclusive alternative models. Please exp la in how to interpret Table 10-11 in terms of alternative logic tree branches, and how that is consistent with the aleatory nature of the variability implied by the term "relative frequency." 766 Line 737-738 Same as comment for Lines 623, 670 and 702: Please check whether the phrase "alternative earthquake scenario magnitudes and frequencies for complex and splay rupture sources" actually communicates what is intended If so, please explain how alternative" scenarios can be reconciled with the sentence beginning on Line 520 that says "Aleatory magnitude variability is introduced by involving more than one scenario earthquake pair, whereby the relative frequency of the scenario earthquake pair is defined." The scenarios are either "alternatives" or they occur collectively with some "relative frequency, and it is not clear how both statements can be correct 767 Line 742 Table 10-12 SH-HB Tier one segment boundary? 768 Line 744 No asterisk in Table 10-12 769 Line 752 Figure 10-36. Please explain -if the dip of the Los Osos is 60. -why doesn't the surface projection of the rupture parallel the fault? 770 Line 756 Same comment as for Lines 653, 689:, and 722: II is not clear what is meant by "alternative aleatory logic tree branch values," given that Table 10-14 appears to describe relative frequencies, not mutually exclusive allernative models. Please explain how to interpret Table 10-14 in terms of alternative logic tree branches. and how that is consistent with the aleatory nature of the variability implied by the term "relative frequency." 771 Line 762 Tables 10-14-some descriptions (Faults) have main or splay written in column but not all -please make consistent for all tables 772 780 Please specify (at least on the figure caption or figure notes) the magnitude bin size used for the incremental distribution (since the curve does not appear to be normalized to unit magnitude increment). on this figure and other MFD plots (otherwise the incremental and cumulative plots cannot be reconciled). 773 Line 798 This seems to be the first occurrence of the term "reduced source MFD." Please define it (e.g., is it distinct from the Point MFDs in Figure 43?). 774 Line 803 Figure 10-44 caption. "the rates for both subevents is the same" replace is with are 775 Line 805 Please clarify the meaning of "Hosgri source MFD." 776 Line 807 Might rephrase to indicate that these sources are characterized using the maximum magnitude PDF. Otherwise, it may be unclear what is meant by "simplified maximum magnitude sources:* 777 Line 829 Figure caption -please remove one "at the" in the phrase "al the at the Hosgri subevent" 778 Line 847 Figure 10-45 appears (based on the slope of left-hand extreme of the cumulative curve) to have been constructed with a magnitude bin size of approximately 0.05 magnitude units, whereas (judging by the slope breaks on the blue curve) Figure 10-46 appears to have been constructed with a magnitude bin size of approximately 0.1 magnitude units. If it is the case that they were constructed with different bin sizes, please explain what normalizations were done to ensure that these curves are comparable. If the apparent difference in bin sizes is illusory, please clarify. 779 Figure 10-3 Correct the spelling of "strike" in the header for the top figure (a). Also, why not use the same symbols for the models that are in common between the two fiQure parts (a and bl 780 Figure 10-45 Definitions of the dashed and solid lines in the Explanation are reversed. 781 Line 863 "or some other feature of the inversion solution (Page et al., 2014 )." Please clarify some other feature 782 Line 866 Figure 10-Please change is to are "the rates for both subevents is the same." 47. Please correct for all odd numbered figures that follow Figure 10-47 in this section. 783 Line 883 Whether the ground motions will be higher or not is a GMC and hazard issue. It is suggested that the reader just be reminded that other sources contribute to these scenarios besides just the Shoreline fault portion. 784 Line 973 Replace is with are APPENDIX -WAACY Model 785 Line 27 Might want to use another word than characterize as it might introduce confusion with "characteristic model" 786 Line 34 Is this the motivation that the authors of the model had for developing it in the first place? If so. this should be past tense. 787 Line 44 Any recurrence curve, by definition, permits a broad aleatory variability in magnitude. Not clear that this is an actual constraint. Isn't the real constraint that large Mmax's are allowed (more than the characteristic earthquake model) and small CVs are met (unlike the exponential model)? 788 Line 47 Note the missing")". 789 Lines 52-53 Please clarify what the distinction is between "fits a doubly-truncated exponential" and "is a doubly-truncated exponential". 790 Line 68 Mmin of 5 is used for hazard integration, but is not common practice for purposes of earthquake recurrence, especially when filling recurrence curves to observed seismicity. 791 Line 68 Table W-1, "Values larger than 3 yield results that are indistinguishable from 3 for bhighbox the DCPP." This is a bit confusing. Why not state that "values of 3 and larger yield results that are indistinguishable at DCPP" 792 Lines 78-79 What units are used in Dave? Centimeters? Meters? 793 Line 92 Replace SOS, 13 with S09, 13 794 Line 104 Please check whether this is the first reference in the text (apart from Table W-1) to the 0.55 value of the displacement CV threshold. If so, please indicate here that you refer to the 0.55 threshold estimated by Hecker et al. (2013). 795 Line 139 Suggested should maybe be "suggest", as it still applies. If accepted, change "included in line 140 to include". 796 Line 142 It appears that instead of "values and weights" of the fixed parameters being shown in Table W-2, it is actually parameter name and fixed value. Please clarify. 797 Lines 209-211 "We note that for Group B cases, the parameter combination of 12% moment and = 1 exceeded the CV threshold value of 0.55 (Figure W-5)." Please discuss weighting for Group B versus Group C for 12% moment in Figure W-7. Based on Figure W-6. It appears that Group C should have an equal or lower weight than Group B for the 12% moment? Comment Location in Text Number 798 Line 1 799 Line 2 800 Line 12 801 Line 17 802 Line 35 803 Lines 39-40 804 Line 42 805 Lines 43-46 806 Line 52 807 Line 57-59 808 Line 64 PPRP Comment Response Table Installment #4 PPRP Comment CHAPTER 13-Areal Source Zones Please consider adding some additional introductory information, such as the topics that will be covered in this chapter. Delete "of." "but the faults are not sufficiently active to be considered" Consider adding "or well-constrained or studied as there may be other faults of similar activity to the Shoreline fault that have simply not been identified or studied. It would be useful to acknowledge that, although it is recognized that moderate-to-large earthquakes rupture finite lengths of faults, at large distances those ruptures can be approximated by ruptures effectively at a point for purposes of seismic hazard analysis. Add "smoothing" after Gaussian. Please give the units for the quantity 1 O" (e.g., is this an annualized rate for M>O events?). A factor of 0.1 would appear to be the correction factor for accounting for the 0. 1 magnitude increment, not the factor 0.184 cited on this line. The latter would appear to account for the 0. 1 factor multiplied by the additional factor 1.84, which equals bx log.(10), and accounts for the relationship between the exponential density function and the Gutenberg-Richter cumulative distribution. Please check whether this explanation is correct and make any required changes in the text. This leaves the reader wondering what the implications are for the research coming out after the model was locked down. Please explain how this is relevant -did you use it or not? If so, then consider deleting this sentence. as it is irrelevant. If not. then close with a statement of what was and was not used. As it is. there is no final context to understand the meaninq of this sentence Replace we make" with "the Tl Team makes." This sentence as written seems to say that the given latitude/longitude range is that part of the Regional ASZ that extends beyond the 320 km limits. whereas Figure 13-1 makes it clear that the given latitude/longitude range actually defines the full Regional ASZ (and this full range happens to extend beyond the 320 km limits). Please rewrite to clarify the meaning. The concept of a "DCPP Site Vicinity seems to be important enough to be named and capitalized. yet has not been defined up to this point in Chapter 13. From Figure 13-1, it seems to be defined by a 40 km radius circle centered at DCPP. but this has not been made explicit. Please make sure this term has been defined prior to its use, and also be Summary of Revisions to Report consistent with capitalization (e.g., note that the term is capitalized in the text, but not in the figure legend). 809 Lines 67-68 It is not clear at this point why two catalogs are being considered, how the comparisons with the predicted rate will be done, or what "adjustments to the baseline gridded seismicity rates means. Please provide more explanation and context. What type of "adjustments" would be made if there are differences? Or reference other parts of the report where these issue are discussed. 810 Line 74 It would help the reader to also indicate that those two catalogs are discussed below 811 Line 75 Considered for what? Remind the reader what the catalogs are being considered for and how they will be used. 812 Line 88 This would read more clearly if "the" was placed before "Felzer" 813 Line 88 This is a methodology section, but it would help the reader if a pointer was made to the section where the conclusions from exercising the methodology for the Vicinity sources are given. 814 Line 106 Again, a pointer to where the Local sources are described would be useful. 815 Line 117 Please be specific about what quantity is plotted in Figure 13-2 (e.g., is it the annual rate of events in a 0.1 magnitude-unit wide bin centered on MO, per 0.1 x 0.1 degree spatial bin?). 816 Lines 124-125 Please provide further technical support for the 70%-30% distribution (e.g., is it consistent with focal mechanism distributions where those data are available?), or reference sensitivity studies or other evidence that indicate that the effect of this distribution is not hazard sianificant. 817 Line 142 Please consider replacing second "and" in the sentence with .. as well as" 818 Line 149 Agreed that it is a less clear association. but Edna and the western portion of the Los Osos show some spatial association with microseismicity -please consider softening by using "less clear association" -rather than "no clear association" 819 Line 154 Please consider "higher density" as a replacement for (the slightly awkward) "qualitative[ly) greater number." 820 Line 189, Table 13-2 This table needs a caption explaining each of the Table elements. Also, the implied scale factor is not clearly explained. 821 Line 207 Consider replacing "that" with "as to which" for clarity 822 Line 209-211 Please state why this 3-point distribution is an adequate representation of the CBR of the TOI. 823 Line 218 Consider changing to a "greater extent" 824 Lines 215-223 Consider breaking up this very long sentence, for clarity. 825 Line 247 "study" should be plural. 826 Line 248 Please define what is meant by virtual faults." or indicate in the text that this term is used in a sense that will be explained later in the chapter. 827 Line 250 Please define what is meant by "semi-randomly," or indicate in the text that this term is used in a sense that will be explained later in the chaoter, if that is the case 828 Line 254 Need an introductory sentence that states what this section is about. 829 Lines 257 and Consider using a. b c, etc rather than#. x, and y for the 2014 PG&E numerous other citations. Also, there are 8 PG&E 2014# citations listed in the references locations section. Please rename them all so the reader knows which citation refers to which reference. 830 Line 282 Replace "was" with "were." 831 Line 285 The word inference is pretty weak. How about. "it can reasonably be concluded? 832 Line 304 Figure 13-6 should be 13-5. 833 Line 315 To the extent possible, it would be preferable to replace references to workshop presentations by references to published reports or papers. For example, please consider whether the pertinent part of McLaren's powerpoint presentation could be covered by references to Mclaren & Savage (2001) and to the 2011 PG&E Shoreline Fault report. Please check on the viability of similar substitutions for the other workshop powerpoint presentations cited in this paragraph 834 Lines 327 -332 Consider breaking this long sentence into a couple of parts to assist the reader. 835 Line 332 This sentence would read more clearly if "is more problematic" was placed after "Local Source Zone" in line 331 . 836 Line 341 Please state the basis for the Tl Team judgment that the method and results are unreliable for identifying laterally continuous fault sources in this context. 837 Line 346 The dips might be consistent: however. the OADC-FM fault plane solutions dip in the opposi1e direction lo the dips in the NE and SW vergent models as well as dips interpre1ed from seismic and well data in 1he CCCSIP. Please clarify. 838 Line 348 "Map" should be plural. 839 Line 351 Please consider deleting "compiled from that effort" 840 Line 359 Insert "shown" (i.e., "is shown on"). 841 Lines 365-367 Might consider rephrasing -The Tl Team judged that the quality of the seismic reflection data used to delineate the faults was poor and introduced much uncertainty in mapping fault dip and architecture, a concern exoressed bv the authors (PG&E, 2014#, Chaoter n 842 Lines 371-37 4 Also might want to mention that even though the interpretations are uncertain they are constrained/consistent with well data in the region. 843 Line 384 "within the" is repeated -please delete one 844 Lines 389-392 Please explain why the existence of a residual uncertainty as to the amount of strike-slip deformation present would justify assigning strike slip a higher frequency of occurrence relative to the reverse style (i.e., if I have a C average on half the class assignments, and don't turn in the other half, there is residual uncertainty about how many A's I would have aotten, but this mav not iustifv raisina mv arade to a Bl 845 Line 396 Remove hyphen in half-way; also please check hyphens throughout text (e.g., line 389, well constrained needs a hyphen). 846 Line 421 Note typo: "Where" should be lower case. 847 Line 421 As noted in a previous comment. the factor 0.184 appears to account for both the magnitude increment and the transfo1TT1ation from the incremental to the cumulative magnitude-frequency relationship. Please check and make aoorooriate chanaes in the text. 848 Line 452 Table 13-3 has NE and SW dips for both strike slip and reverse -the logic tree in Figure 13-14 has Nor NE and Sand SW for reverse faults -olease make consistent. 849 Line 457 Please add at this point in the text that "slip rates for the virtual faults" in this context will mean the sum of slip rates across all the virtual faults Currently this is a point of confusion until it is finally explained on Line 491-493 and in the footnote to Table 13-5. 850 Line 466 Might want to add some supporting info1TT1ation as to why less than about 4. 851 Line 472 Please check whether Mo on the left side of Equation 13-5 should actually be Mc .*. If so, please correct, and if not, please explain what Mo.1 means on the riaht side of Equation 13-6. 852 Lines 479 and 480 The "s" needs a dot above it to indicate that ii is slip rate. Otherwise, this equation will be mistaken for the equation for Mo. Use of "s" for slip is standard notation. so using it without the dot for slip rate will be confusing. 853 Line 505 Please check and correct this rate. which should probably be O 07 mm/yr. 854 Figure 13-1 Using colors in the explanation is a little problematic as they don't match the colors in the figure in a consistent way due to overlapping color with some transparency. For instance, the regional source zone has a different color onshore versus offshore. 855 Figure 13-2 Please give the units for the rates shown in the legend (e.g., indicate that they are annual rates if that is the case), and be specific (in the text or a caption or note on the figure) about what quantity is plotted. E.g., does it represent the annual rate of events in a 0.1 magnitude-unit wide bin containing Magnitude 0, as estimated by 0. 184 x 10" (where a is the annual rate of events of M>O) as Line 42 seems to indicate? Consider adding the majorfaulls to this figure -would clearly show that the nearest red areas are associated with the San Andreas fault. 856 Figures 13-3, -4, -5 In the "Explanation", where is spelled "wehere" and buried is spelled burried". Please correct the spelling in all such figures, as the error is repeated. 857 Figure 13-6 Observe 2 colors for the 0.1* grid; however only one color (yellow) shown in legend 858 Figure 13-8 Notes state "Figure modified by Hardebeck, 2012: Legend states From Hardebeck, 2011" If the distinction is intentional and necessary, please add some clarification. If both references are to the same content, please make consistent. 859 Figure 13-9 The figure has PE as a site. whereas the Abbreviations: lists it as PB for Point Estero. Please correct the abbreviations to PE so that they are consistent. 860 Figure 13-11 Cites PG&E (2014). Is this 2014x. 2014y or 2014#??? 861 Figure 13-12 No apparent dip symbols appear to be used in the figure. Either make these larger/clearer or delete reference to them in the "Geologic Symbols" explanation. 862 Figure 13-13 Is it reasonable to have virtual faults that cross the Hosgri fault zone? APPENDIX -Earthquake Catalog 863 Line 28-29 Please consider whether there is actual support for the claim of "better-quality relocations than other available methods "Inserting this claim does not appear to add any useful information. and an option would be to delete the comparative statement and instead to state what specific attributes tomoDD provides that proved important to the outcome. 864 Lines 104-108 States that focal mechanisms were assigned a quality rating of A through C, but the lower-quality D rating was introduced. It would be clearer to state that they were assigned a quality rating of A through D, and then qualify the various ratinas. 865 Lines 143-147 These two sentences sound contradictory, i.e. there is "no material difference," yet there is a "difference of note." Please reword to avoid the appearance of inconsistency. Given the differences in locations, what was done? Either state the decision here or point to where it is discussed in the report. 866 Line 161 Refers to attachment X-3. but this was not provided. Same with attachment X-4 on line 173. 867 Citations PG&E These are electronic files provided to S. Thompson, but where are they 2014a and 2014b now? If someone wants to look at these files, how would they acquire them? Is there a URL that can be referenced? 868 Figs. X-1. X-3, and X-The explanations of these figures have the same spelling errors noted in 4 figs. 13.3, 13.4 and 13.5. APPENDIX H -Final SSC Model Hazard Input Document (HID) 869 Line tO Model-building is restricted to the Tl Team. Suggest changing to "to implement" the SSC model. 870 Line 25 Are areal sources and areal source zones the same thing? Suggest consistent use. 871 Line 30 Source-site? Source to site would be clearer. 872 Line 104 Table H.2-4 Rupture sources for Hosgri Table H.2-4 lists 7 sources (all three FGMs); 7 however, in Table H.2-6 there are 8 rupture sources for the Hosgri 873 Line 130 Should 7 ruptures be 8 ruptures? 874 Line 184 Please add the missing parenthesis at the end of the sentence. 875 Line 189 Why are some "sub" rupture in italics? 876 Table H.2-15 Standard deviation is zero?? Please clarify (e.g .. would it be more appropriate to say "n/a", as is done for truncation factor on the next line). 877 Line 246 Figure H-7. Might consider changing figure so it parallels text (a) maximum magnitude (bl Y-C characteristic (c) exponential (d) WAACY 878 Line 288 Delete "is" between "term" and "in for clarity. 879 Line 299 Table H.2-Why is OV-09 linked and Characteristic-why is it not Category B? 22. (LP+FS+FN+ON+OF) Please check other tables with linked faults H.2-24, H.2-26 880 Line 399 Table H.6-1 has NE and SW dipping reverse faults; logic tree Figure H-13 has N or NE and S and SW for the reverse faults -please make consistent. APPENDIX S-Workshop Summaries 881 Line 21 "A GMC model -"A" should be lower case 882 Line 24 Change "are" to "is as the verb refers to "Each workshop presentation" 883 Line 34 Consider spelling out RE at first usage in the appendix. 884 Line 53 You should not leave the reader with the impression that the master list of data collection activities coming from the workshop was, in fact, funded. 885 Line 56 Delete "but." 886 Line 56 Insert "are" after "presentations" for clarity 887 Line 101 Typically, the term "hazard" is used to specify the annual frequency of exceedance (y-axis of the hazard curve), rather than the ground motion (x-axis of the hazard curve) for a given AFE. Please clarify if this is the way that "hazard" is used here and subsequently when talking about percent contribution to the hazard (ie. is it the AFE or the ground motion at a given AFE?) 888 Lines 107-108 "none of the more distant faults contributes >1% to hazard ... " Is this per fault? In which case, because there are a lot of faults, could sum to significant hazard, or does this mean that these distant faults cumulatively amount to < 1 % of total hazard? Please clarify. 889 Line 113 Delete 2nd "that." 890 Line 113 The tornado diagrams actually show the sensitivity to hazard uncertainty, rather than to hazard itself. Suggest stating that they show the range in hazard results for the range in values of an input parameter in the logic tree. Thus, they show how much uncertainty in a parameter leads to uncertainty in the hazard result. If no uncertainty is included for a given oarameter, it shows no contribution to hazard uncertaintv. 891 Line t14 Delete the extra "that" 892 Line 186 Insert "USGS" in front of "."CRADA 893 Lines 261-271 Change all "Mr. Thatcher" citations to "Dr. Thatcher" -use is inconsistent here. 894 Line 283 Insert "for" after "rotation" for clarity 895 Line 329 "Rate" should be singular (?) 896 Lines 330-333 Is the maximum unaccounted for plate motion parallel or normal to the SAF? Please clarify. 897 Line 442 Check spelling of "Mohorovic." 898 Line 469 Please change "daps lo "gaps." 899 Line 500 Heave is not associated wilh the presence of a shallow/hard bottom -rather it is related to sea slate 900 Line 523 Insert "depth -so it reads "10 lo 15 km depth." 901 Line 567 "Investigations is lower case 902 Line 637 Should PPRP comments and Tl team responses be inserted here for Workshop #1 and likewise forWS#2 and WS#3? If not, then please point the reader to where they can be found. 903 Line 672 Consider deleting first "sensitivity." 904 Lines 822-824 Did Hamilton conclude or present this or is this inferred by the relationships he reported -if the latter might want to consider deleting. 905 Line 889 Clark reference? 906 Line 981 Replace "or with "to" 907 Line 988 In the near "shore," i.e., add "shore" 908 Lines 1077-1078 This might be stated more accurately as incorporating the additional uncertainty that would result from considering non-Poissonian temporal models, such as a renewal model. 909 Line 1116 Replace "N." with "Dr." 910 Line1131 Should PPRP comments and Tl Team responses for WS#2 go here? 911 Line 1225 Insert "then" -so it reads "then replaced." 912 Lines 1259, 1262, "Mr. Abrahamson" should probably be replaced by "Mr. AbramsonWard". 1277 Please check and correct if necessary. 913 Line 1289 Spell out "HN" ("horizontal to vertical") for clarity 914 Line 1290, 1291 Replace "Mr." with "Dr." 915 Line 1291 'These data yield". Actually, these are not data, but rather, interpretations. 916 Line 1312 Please replace "frequency" with "function" to reflect the correct interpretation of "CDF ." 917 Line 1385 "and is it ready ... " would read more clearly if written "and questions whether it is ready ... " 918 Line 1393 Replace "The" with "the" Also add period at end of sentence. Check the other PPRP sentences like this one as they also are missina periods at lhe end of the sentence. 919 Line 1400 Replace "generals" with "general." 920 Line 1608 Replace period with a question mark. APPENDIX Y -Data Summary and Geospatial Databases 921 Line 3 Data is plural, so change "was" to "were" 922 Line 40 Insert "the" between "as" and "Shoreline" 923 Page Y-8 Replace "maps" with map Folder name .. \Geographic_feature s 924 Page Y-20 (198") year? Folder name .. \other_ data\Diver _g eology Comment Location in Text Number 925 926 927 Lines 68-71 928 Line 81 929 Line 95 930 Line 99 931 Lines 101-103 932 Lines 107-108 933 Lines 110-1t1 PPRP Comment Response Table Installment #5 PPRP Comment CHAPTER 14-Hazard Sensitivity General comment: at several locations, only a discussion is given of what the sensitivity analyses show. More discussion is needed of these results occur. particularly as related to the particular elements of the SSC model. Otherwise, the reader is left to ponder and, given the various assumptions that were used to construct the sensitivity cases, may question whether the result is credible. General comment: Figure captions (or "notes" for the PG&E template) are very much needed for this chapter. Without them, the reader is forced to flip back and forth between the figure and the text in order to gain an understanding of the important messages being portrayed. The captions should draw the basic conclusions-or "take-aways-for each figure. It is suggested that this sentence be the topic sentence for the chapter. Consider putting the sentence from Lines 109-111 at the end of this section. Please replace "was" with "were". It is suggested that a description be given of what the tornado plots show (relative contributions to hazard uncertainty) and why they are called tornado plots (largest contributors to uncertainty are placed at the top of the diagram) The explanation of the construction of the tornado plots is given more precisely and clearly here than has been customary (thanks!). But a corollary of the description (specifically, of the normalization) seems to be that the values on a given line of a tornado plot (weighted by their branch weights) should sum to unity. Visually, that appears to be at least roughly true in most cases. But there are exceptions, e.g .. "IHEB Areal" in Figures 14-7, 14-8. "synchronous GM" in Figure 14-9, 14-10, "full characteristic" in Figures 14-11, 14-12, "magnitude PDF in Figure 14-12. If this is a misunderstanding, please clarify (e.g., perhaps it is mistaken to identify each line of a tornado plot with a node of the logic tree?) If this is correct. please refine the explanation of the tornado plots to accommodate the apparent exceptions to the current definition What are the "some cases" and please explain why they provide a value that is not in the logic tree. Does this mean that the conclusion drawn from the sensitivity analyses are also "not representative"? Perhaps it would be more accurate to say that the levels or amplitudes of ground motions may not be indicative of the final hazard results that are based on the inclusion of the full SWUS GMCmodel. Summary of Revisions to Report 934 Line 119 The figures and text refer variously to "annual frequency of exceedance (AFE), annual exceedance probability (AEP). and annual exceedance of probability." Please make them consistent throughout figures and text. 935 Line 121, Figure 14-There is actually a visible difference in hazard in Figure 14-1a at AFEs 1a greater than 10-4. Is there a reason that it is not noted here? If it is not significant, please so state. 936 Line 125 Please discuss the reasons for the differences in hazard level between the 2015 SSC and 2011 Shoreline models. In particular, why has hazard dropped systematically for the low ground motion levels, and increased systematically (at least in the 05 Hz case) at high ground motion levels? 937 Lines 133-136 It might help the reader by stating something like: For example, as shown in Figure 14-1a. the mean AEP associated with at 5 Hz spectral acceleration of 1 g is about 10-3. 938 Line 154 Replace "past" with "previous" 939 Line 158 An explanation for the contribution at higher frequencies made by the IHEB source zone would be helpful to the reader. 940 Line 163-165 Please compare the relative hazard from the Local areal source zone with the corresponding result from the 2011 Shoreline model and discuss possible explanations for any differences. 941 Lines 165-167 Any explanation why the SA contributes at the lower ground motions? It is likely related to the relatively high rate of occurrence of large earthquakes on the SA, but the great distance lowers the likelihood of lamer around motions. 942 Lines 182-185 Consider noting that such an observation is not unusual for site-specific hazard results. 943 Line 188 Please make reference to the specific section of the report that describes these logic tree branches and weights. 944 Line 192 Please explain why this simplifying assumption is made (these are the highest weighted FGMs?) 945 Line 200 Please explain why these AEPs are used for the display. 946 Lines 205 and 231 The weights on Line 231 give the appearance of being rounded representations of the weights on Line 205. If this is so, please clarify why one case was rounded and the other not. And, in any event, please clarify why the weights on Line 205 are expressed to such high precision while those on 231 are not. 947 Line 214 Replace "as with "and" 948 Lines 222-225 Please discuss the factors which may account for the stated differences in hazard from the three FGMs. 949 Line 224 Replace "unit" with "unity." 950 Line 227 Figure 14-8. Please provide figure captions and spell out abbreviations. Would be helpful if figures and figure captions were self explanatory. 951 Line 238 and 240 Replace "done" with "performed" 952 Line 239 This is not the "standard" for host zones any longer (e.g .. CEUS SSC model, Hanford PSHA. BC Hydro, etc.). Suggest deleting "in a more standard wav". 953 Lines 252-259 One might have speculated that smaller dip would decrease the average Rjb distance of DCPP from the virtual faults, and thereby would affect hazard measurably. Please consider whether some simple explanation can be provided for why this is not what is seen in the sensitivity analysis 954 Line 260 (general The section heading. figure captions. and most of the text, describe this comment on section as a section on time dependency. But the complex and splay 14.2.6) mechanism sensitivities are tucked away in this section too. Anyone scanning the chapter or figures for the latter sensitivities will likely not find them. Please consider making the full purpose of the section and its figures more transparent. 955 Lines 265-266 This is not necessarily "expected. The contribution to hazard uncertainty that the EPR branches make could be small if the range of EPR values was small-despite the dominant contribution of the Hosgri fault to the hazard. In other words. the large contribution of the Hosgri fault to the hazard means that the details of the characterization of that source are generally more important than other sources. But that does not mean that any given characteristic of that source will contribute significantly to the hazard. The EPR is one that does. 956 Lines 265-269 The sensitivity to Hosgri EPR appears to be significantly higher for 0.5 Hz than for 5.0 Hz. If this is a correct understanding, please comment on it and if possible suggest an explanation. 957 Lines 269-272 Interesting. in that the SAF is known to be at or near the end of the seismic cycle -why doesn't this have more of an effect? 958 Lines 282-283 Consider adding the phrase to the end of the sentence "due to the lack of including the secondary (or splay) rupture event" 959 Lines 285-287 Please discuss this a little further. Does this reflect that those ruptures are very infrequent in the model and therefore contribute very little to hazard to begin with? Or does it reflect the dominance of the primary rupture, such that the SSRS is little affected by the secondary rupture? Or both? 960 Lines 286-287 More accurately, the inclusion of the complex (or splay) ruptures or not does not have a significant contribution to the uncertainty in the total hazard. 961 Line 303 Replace "unit" with "unity" 962 Lines 312-316 Please provide an explanation for why this is the case. 963 Lines 331-335 Please provide an explanation for why this is the result 964 Line 343 Should "plots" be singular? 965 Lines 353-354 This explanation needs bolstering. Is it only the proximity of the Hosgri fault to the site? Both the slip rate and the EPR are directly tied to the recurrence rate. is that why they contribute most to the uncertainty in hazard? The Hosgri fault's slip rate is 1-2 orders of magnitude greater than any other nearby fault AND it is close to the site. Why not spell out why this result is expected, as this is the concluding punch of the chapter. From: To: Cc:

Subject:

Date: Attachments: Steve, Kevin Coppersmith Sieve Thompson; William Lettis sday@mail sdsu edu; ndriscoll@ucsd.edu; Thomas Rockwell Non-Mandatory Comments Saturday. February 28, 201 S 4:08:42 PM Non-mandatory Comments 1st Round.docx As I mentioned on the phone, after reviewing the revised draft report Chapters 1-7, 9, 11, and 12, we have identified non-mandatory comments that we are passing along to you. We believe that responding to these comments will improve the report and add clarity, but a formal response from the Tl Team is not required. We will forward our non-mandatory comments, if any, on the remaining chapters after completing our review. Best, Kevin Coppersmith Consulting, Inc. 2121 '.\/.California Blvd, Suite 290 Walnut Creek. CA 94596 P 925 F 925 932-3506 From: To:

Subject:

Date: Hi Steve, Kevin Coppersmich Sieve Thompson Non-Mandatory Comments Friday, March 6, 201 S 11: 10:38 AM As these come in to me from the Panel, I will pass them along to you. All very minor. Chapter 10: The only minor darity issue is on line 62 l -" ... then a rupture 10 km could occur on most of the source without passing X. R 1 = 70 km and ... " This would read more clearly if it read " ... then a rupture of 10 km length could occur ... " Thanks Kevin Coppersmith Consulting. Inc. 2121 N. California Blvd. Suite 290 Walnut Creek. CA 945% p 925 974-3335 F 925 932-3506 November 26, 2012 Mr. Kent Ferre, SE Project Manager Geosciences Department Pacific Gas and Electric Company San Francisco, CA 94177 Via email

Subject:

Participatory Peer Review Panel Report on Workshop #2, Diablo Canyon Seismic Source Characterization Workshop #2

Dear Kent,

This letter constitutes the report of the Participatory Peer Review Panel (PPRP) on Workshop No. 2 (WS2) of the Diablo Canyon Seismic Source Characterization (SSC). The workshop was held November 6 -8, 2012 in San Luis Obispo, California. Following guidance described in the Project Plan1 for the PPRP, and consistent with the expectations of the SSHAC Level 32 process, the PPRP participated in WS2 as observers in order to be informed and to review both procedural and technical aspects of the workshop. All four members of the PPRP (K. Coppersmith, S. Day, N. Driscoll, and T. Rockwell) attended WS2 and, collectively, the Panel observed all aspects of the workshop. The PPRP met each day with the Tl Lead, some Tl Team members, Project Manager, and the PG&E Geosciences Department manager. The purpose of these meetings was for the PPRP to provide their comments and suggestions for "mid-course corrections" to the ongoing workshop. As described in NUREG-2117, the PPRP is responsible for review of both the technical as well as the process aspects of the project. Therefore, the Panel's recommendations relate to certain aspects of the SSC technical evaluations as well as to ways that the process might be implemented to ensure that the goals of a SSHAC process are met. We offer these recommendations in the spirit of our common goal; a successful project that meets the objective of a SSHAC process that successfully captures the center. body, and range of technically defensible interpretations. The Panel's general observations as well as specific comments and recommendations are provided for your consideration below. 1 Diablo Canyon SSC Model Update Using SSHAC Level 3 Methodology, Project Plan for the Diablo Canyon Seismic Source Characterization (SSC) Model Update. dated July 18. 2012. 2 NUREG-2117, 2012, Practical Implementation Guidelines for SSHAC Level 3 and 4 Hazard Studies, NUREG-2117, U.S. Nuclear Regulatory Commission, Office of Nuclear Regulatory Research. Washington, DC 20555-0001. DCPP SSC WS2 PPRP Letter 11-16-12 Page 1 General Observations Workshop #2 of a SSHAC Level 3 process is the second workshop of the evaluation phase of the study, during which the data, models, and methods of the larger technical community are evaluated. The focus is on data presented by resource experts and models and methods presented by proponent experts. After Workshop #2, the project will move into the integration phase, during which the preliminary SSC model will be constructed. The PPRP would like to congratulate the DCPP SSHAC SSC project team for a very informative and useful workshop. Workshop 2 was very successful and the PPRP acknowledges the great amount of work performed by the Tl Team organizing the workshop and preparing the participants. The proponent experts were charged with a series of questions that helped focus their presentations and provided continuity to the workshop. The speakers did an excellent job staying on task and addressing the questions posed by the Tl Team. The meeting was well-coordinated and sequenced with good time management. The interaction amongst the Tl Team was dynamic; the Tl Team did an excellent job probing the proponent experts to evaluate and understand the models presented. The Tl Team was responsive to the suggestions made each day by the PPRP to improve the workshop. A good example was the improvement in the end-of-the-day summary conducted each day by the Tl Lead. The Tl Team also employed a novel approach of inviting resource experts, many of whom gave short "pop-up" presentations during the discussion section that helped clarify issues and raised alternative hypotheses. This proved to be very effective and the Tl Team should be commended. In addition, the Tl team did an outstanding job outlining and enforcing the roles and responsibilities of the Workshop 2 participants. In summary, this was an excellent workshop and it adhered to the requirements outlined in NUREG-2117 for a SSHAC Workshop #2. Specific Comments and Recommendations 1. Project Schedule The PPRP recommends that a detailed schedule for all working meetings, Workshop 3, deliverables, and other key activities be updated and issued by project management in the form of an updated Project Plan. At Workshop 3, the PPRP plays an active role and the preliminary model will be presented. Accordingly, the PPRP requires sufficient time to review the data evaluation and integration process, as well as the details of the SSC model. For the process to be effective, documents that describe the evaluation and integration processes need to be provided to the PPRP in a timely fashion well in advance of the workshop. It is the Panel's understanding that the Tl Team is using data summary and data evaluation sheets to document the data, models, and methods that are being reviewed during the evaluation phase of the project. These data tables need to be completed by the Tl Team when the data are examined prior to the model building process. In addition to the data tables, the PPRP would like to request a copy of the DCPP SSC WS2 PPRP Letter 11-16-12 Page 2 Hazard Input Document (HID, see NUREG-2117, Section 4.7.2) and any other documents that will describe the preliminary SSC model. Up to the present time, the participation of the PPRP in working meetings has been limited due to budget constraints. However, as the project moves into the process of evaluating the extensive data being gathered, as well as into the model-building process, we request that at least one member of the PPRP participates as an observer in the working meetings throughout the model building process leading up to WS3. As discussed in NUREG-2117: "However, provided that the boundaries are maintained and the clear separation of reviewers and evaluators is respected, then one or more representatives of the PPRP may attend the working meetings of the evaluator experts as observers. This could bring benefits of providing information to the entire PPRP via the observer representative at an early stage regarding the manner in which the evaluation and integration processes are being conducted. Such information can assist the PPRP in their later reviews of the bases for the technical assessments and their review of the project conduct and documentation. This is particularly true in Level 3 studies in which technical challenges to various interpretations by evaluators occur in the working meetings, as well as in the workshops." (p. 50) Given the expected large numbers of assessments and possibly complex components to the preliminary SSC model, coupled with the active role that the PPRP will play at WS3, participation as observers will greatly assist the Panel in gaining a first-hand understanding of the technical bases that underpin the preliminary SSC model. 2. Strategy for Recurrence Models Assessment of the impact of using different recurrence models turns out to rank at the top of the tornado diagram in terms of hazard significance. The Tl team needs to develop a clear strategy on how to deal with non-Poissonian models in light of the fact that it is unlikely that well-resolved information on the slip rates and timing of past earthquakes on the fault zones will be available, which are critical to the hazard assessment at DCPP. Specifically, use of renewal models requires information on the recency and rate of activity of a specific fault and these types of data are not likely to be forthcoming in the time between now and when WS3 is conducted. The Tl team will therefore need to develop and defend a model with large uncertainties that may have significant impact on the hazard to DCPP. Alternatively, the Tl team may wish to reconsider the use of non-Poissonian models, as it is clear from long paleoseismic records in California that earthquake recurrence has demonstrably large coefficients of variations and there is not a clear benefit in moving away from the state-of-the-practice of using Poissonian recurrence distributions. 3. Strategy for Consideration of Research Projects The workshop provided an excellent opportunity for the Tl Team to understand the data, models, and methods that the larger technical community is using to characterize seismic sources in California. In most cases, the presentations and discussions involved research-oriented activities and initiatives (e.g., UCERF3) that are designed to (1) push DCPP SSC WS2 PPRP Letter 11-16-12 Page 3 the state of the art and (2) to provide input to regional seismic hazard studies. We suggest that the Tl Team develop a strategy for how they will evaluate these other efforts and what elements of those studies are applicable to the site-specific SSC model and PSHA at the Diablo Canyon site. For example, much of the discussion at the workshop surrounding the concept of segmentation resulted in the general agreement among the participants that the tool is best used when high-quality behavioral data along a fault can be gathered and analyzed. There is little prospect that such data can be gathered for the Hosgri fault, so a strategy will be needed for how the segmentation tool can be used, if at all, for the DCPP SSC model. Similarly, the UCERF3 Grand Inversion attempts to incorporate various types of fault-specific information for the major faults of California and to incorporate a wide variety of rupture scenarios within the constraints provided by issues such as moment and slip balancing. To what extent can the UCERF3 model provide reliable estimates of SSC parameters for the faults in the DCPP area? If the UCERF3 model is not judged to have sufficient resolution to provide direct information on the local faults, should the conceptual models embedded in the UCERF3 model be adopted locally for DCPP? (e.g., local moment balancing, soft segmentation points resulting from slip rate differences). Because the UCERF3 model is regional and has been designed to provide regional seismic hazard, should it be used at all as either a direct input or even to inform the DCPP SSC model? These are all issues that we suggest need to be included and considered in the development of an overall strategy for the SSC model. 4. Full Participation of All Members of the Tl Team At the workshop, four out of the five members of the Tl team were fully engaged in the discussions. All five members need to be fully engaged and up to speed on all issues related to the SSC model as any member may be called upon in WS3 to defend or explain aspects of the model. In other words, all five members need to take complete ownership of all aspects of the model. As noted in NUREG-2117: During the model-building process, the Tl Team may divide the work among subgroups to expedite the evaluation process. However, the full team should thoroughly review, understand, and endorse the decisions made by any subset of the team because the entire team will be expected to assume ownership of the final model. (p. 74) If not all team members possess the attributes required for participation on the Tl Team, the Tl Lead should consider replacing those members that do not. Time is short and all members will need to be fully engaged to make the deadlines laid out in the project plan. Given the nature of the evaluations that lie ahead for the Tl Team, it may be prudent to include a member with expertise in geophysics and seismology. 5. Strategy for Hazard Model Development The workshop did a very good job of reviewing relevant research on fault behavior. There is clearly a growing recognition that a multiplicity of rupture modes is possible on the regional fault system in California. For example, ruptures may link faults in a great number of ways. A rupture may nucleate on one fault and transfer to other faults, even to faults of differing senses of slip. Critical points on faults (e.g., fault intersections and DCPP SSC WS2 PPRP Letter 11-16-12 Page 4 splays, stepovers, etc.) may sometimes become rupture endpoints, sometimes not, with probabilities that are still poorly understood. The project is therefore faced with a number of challenges: (1) Research on rupture modes such as that being conducted under UCERF-3 is at a regional scale, and only indirectly informs model building at the local scale relevant to the SSHAC study. (2) For the most part, the data required to apply those ideas are absent in the central coast region (e.g., reliable slip rates and timing of past ruptures). (3) That research is rapidly evolving. (4) It is possible that these complex multi-fault rupture models may raise significant interface issues when translated into ground motion models. (5) Given the very large number of potential linkages, end points, and segmentation models, a hazard model could quickly become unwieldy and incomprehensible. The PPRP therefore recommends that the Tl team develop, at the outset, a clear strategy for construction of a workable hazard model. Some elements that should be considered: ( 1) Hazard sensitivity may be an important element of that strategy. While all technically defensible models must be evaluated, it will probably be possible to eliminate some model complexities early in the evaluation process by documenting an absence of hazard significance. (2) The team needs to establish a clear cutoff on the consideration of emerging research results. (3) The strategy should consider potential ground motion interface issues. For example, ruptures that link faults with different senses of slip may raise substantial new problems when translated into ground motion modeling. 6. Data Tables All data that have been evaluated by the Tl Team should be documented in data tables such that the Team can represent the center, body, and range of technically defensible interpretations during the model building process. Accordingly, data summary and evaluation tables should to be completed when data are examined and evaluated. Evaluation entails a number of activities including identifying important technical issues and the ability of the data to address those issues, as well as evaluating the data in terms of their quality and relevance to the assessments being made. Integration is model building to arrive at a defensible expression of knowledge and uncertainty of the inputs to the model. giving due consideration to the available data. This includes the full expression of the model elements (logic-tree branches), their relative weights, and the range of credible uncertainties. Documentation of data evaluation and integration is one of the most important parts of the SSHAC process; it should be performed concurrently with model building. The PPRP needs timely access to this documentation throughout the model building process in order to perform independent evaluation. 7. Lexicon of Terms During the course of Workshop 2, it became clear to the PPRP that key proponent experts were using terminology that had a different meaning for different people. As an example, the term "fault segment" was used by one expert to imply that a section or sections of a fault always ruptures together. whereas others used the same term to represent a change in the style or rate of faulting, a change in fault geometry, or some other aspect of the fault as a way to describe different sections of a fault zone. This DCPP SSC WS2 PPRP Letter 11-16-12 Page 5 causes confusion among the project participants, as well as among outside observers, and could be easily corrected by development of a lexicon of key terms that are used in this study. The PPRP recommends that such a lexicon of definitions be developed for key terms that will be used in the models and reports completed for this project, and that this lexicon be distributed to the appropriate experts to assure common understanding of key issues. 8. Site-Specific SSC Model Acknowledging the excellent cross-section of SSC talent brought to the workshop from the larger community, the Panel notes that nearly all of the participants come from the research community and are involved in regional seismic hazard studies that are not intended to be used for site-specific use and certainly not for use in evaluating the seismic design of nuclear power plants at low annual frequencies of exceedance. Although many of the basic seismic source characterization issues are common to both regional and local PSHAs, there are unique issues that come into play for site-specific studies that the Tl Team will face, but could not be addressed by the participants at the workshop specifically. For example. detailed modeling of fault geometries in the vicinity of the plant site will be important and local constraints on potential models of ruptures that entail faults having different senses of slip may need to be considered. Practical ways of deciding upon the fault-specific selection of applicable magnitude frequency distributions, and decisions regarding appropriate ways of incorporating the epistemic uncertainty in recurrence behavior will need to be considered. These are issues that have been addressed to some extent by others who have developed site-specific SSC models for nuclear facilities. It is suggested that the Tl Team consider the models and methods developed by other resource experts having site-specific PSHA experience. That experience may provide the team with additional insights and practical approaches that have been used to address common problems. 9. Aleatory Approach to Segmentation The discussions of fault segmentation at the workshop provided a valuable range of viewpoints on the issue and served to highlight not only the differences in models, but also the potential approaches that the Tl Team might take as they move forward constructing their SSC model. It is clear to the Panel that the community has moved away from considering the alternative segments that might result from a given segmentation model as epistemic alternatives toward a more aleatory model that includes the occurrence of a wide range of rupture scenarios at their applicable relative frequency. For example, the presentation by Glenn Biasi and comments by Steve Wesnousky reinforce the notion that a very wide range of possibilities are observed for possible controls of rupture segments, but it is more fruitful to consider the relative fraction or frequency with which those controls might limit or extend the ruptures. We suggest that the Team consider moving toward this type of aleatory treatment of alternative rupture scenarios-one that might include a number of credible scenarios each with its relative frequency of occurrence. It is also suggested that the Team consider the rupture case histories discussed at the workshop relative to the specific rupture scenarios that might be included in the SSC DCPP SSC WS2 PPRP Letter 11-16-12 Page 6 model. For example, the Denali earthquake appears to have nucleated on a relatively small thrust fault, with rupture then propagating onto the main strike slip Denali fault. This event and others like it might serve as potential analogs for the relationship between the faults that appear to merge with the Hosgri fault. Likewise, the workshop highlighted the value that might come from considering the orientation of principal stresses relative to the orientation of faults as they change trend. There and other case histories could provide a basis for the consideration and selection of credible and defensible rupture scenarios for the SSC model. Please do not hesitate to contact me if you wish to discuss any of our observations, comments, or recommendations. If it would be helpful, we would be happy to schedule a conference call with the PPRP to explain and discuss any of our recommendations. Sincerely, DCPP SSC PPRP Copy: Kevin Coppersmith, Chair Stephen Day Neal Driscoll Tom Rockwell N. Abrahamson, PTI B. Lettis, SSC Tl Lead DCPP SSC WS2 PPRP Letter 11-16-12 Page 7 April 1, 2014 Mr. Kent Ferre, SE Project Manager Geosciences Department Pacific Gas and Electric Company San Francisco, CA 94177 Via email

Subject:

Participatory Peer Review Panel Report on Workshop #3, Diab/o Canyon Seismic Source Characterization Workshop #3

Dear Mr. Ferre. This letter constitutes the report of the Participatory Peer Review Panel (PPRP) on Workshop No. 3 (WS3) of the Diablo Canyon Seismic Source Characterization (SSC). The workshop was held March 25 -27,

2014 in San Luis Obispo, California. Following guidance described in the Project Plan 1 for the PPRP, and consistent with the expectations of the SSHAC Level 3 process2, the PPRP participated in WS3 as active participants in order to be informed and to review both procedural and technical aspects of the workshop. All four members of the PPRP (K. Coppersmith, S. Day, N. Driscoll, and T. Rockwell) attended WS3 and, collectively, the Panel observed all aspects of the workshop. The PPRP met each day with the Tl Leads, Project Manager, and the PG&E Geosciences Department manager. The purpose of these meetings was for the PPRP to provide their comments and suggestions for "mid-course corrections" to the ongoing workshop. As described in NUREG-2117, the PPRP is responsible for review of both the technical as well as the process aspects of the project. Therefore, the Panel's recommendations relate to certain aspects of the SSC technical evaluations as well as to ways that the process might be implemented to ensure that the goals of a SSHAC process are met. We offer these recommendations in the spirit of our common goal; a successful project that meets the objective of a SSHAC process by capturing the center, body, and range of the technically defensible interpretations (CBR of the TDI). The Panel's general observations as well as specific comments and recommendations are provided for your consideration below. 1 Diablo Canyon SSC Model Update Using SSHAC Level 3 Methodology, Project Plan tor the Diablo Canyon Seismic Source Characterization (SSC) Model Update, dated July 18, 2012. 2 NUREG-2117, 2012, Practical Implementation Guidelines tor SSHAC Level 3 and 4 Hazard Studies, NUREG-2117, U.S. Nuclear Regulatory Commission, Office of Nuclear Regulatory Research, Washington. DC 20555-0001. DCPP SSC WS3 PPRP Letter 04-01-14 Page 1 General Observations We would like to thank and congratulate the SSC Tl Team for a successful workshop. It was clear that much work was done prior to and during the workshop to cover the entire SSC model, its detailed implementation, and its technical justification. We also congratulate the PG&E team for making all of the logistical arrangements to ensure a smoothly run workshop. Specific Comments and Recommendations 1 . SSHAC Level 3 Process The goal of Workshop #3 within a SSHAC Level 3 process, as described in NUREG-2117, is to provide the Tl T earn with feedback in two forms: 1) hazard sensitivity analyses that provide insights into the most significant parts of the preliminary SSC model, and 2) feedback from the PPRP regarding the technical support for the model and the degree to which the model captures the CBR of the TDI. Further, NUREG-2117 prescribes the specific roles that various participants should assume during the course of WS3. For example, all members of the Tl Team are expected to participate in the presentation, discussion, and technical justification for the preliminary SSC model. We were pleased to see that this was certainly the case and this led to thought-provoking discussions and insights into details of the SSC model components, as perceived by various Team members. At WS3 the PPRP is free to question members of the Tl Team regarding details of the SSC model and the technical justification for model elements and the treatment of uncertainties. In this regard, the Tl Team encouraged active PPRP participation and was responsive to the questions posed by the Panel. For example, the Team responded to the Panel's request for changes to the workshop agenda, which allowed additional time to discuss the approach to recurrence modeling. Also, in many cases, the Team positively considered the comments posed by the Panel and will use that information during the finalization of the SSC model. Other aspects of the SSHAC Level 3 process were appropriately conducted. Training in the proper roles of the workshop participants was performed daily, and those roles were enforced. For example, the role of observers was identified throughout the workshop and adequate time was provided for observers to comment on the proceedings daily. An additional bonus, for which the PG&E team should be congratulated, was the organization of a special session at the end of each day to allow the general public to ask questions related to the scientific issues surrounding earthquake hazard analysis. Typically, WS3 within a SSHAC Level 3 project occurs after the completion of the evaluation phase of the work such that proponent and resource experts are not present. An unusual aspect of this project is that data collection activities associated with AB 1632 are ongoing and the PSHA project must consider the results of those activities. Accordingly, PEs and REs were present and participated in the workshop to report their findings. However, the Tl Team was careful to define their role in the workshop and to DCPP SSC WS3 PPRP Letter 04-01-14 Page 2 make it clear how the Team would be considering the results of those studies in the future. The preliminary SSC model was not complete at the time that hazard calculations and sensitivity analyses were conducted for the workshop. However, the PPRP concludes that a sufficient framework, and components of the model had been completed to provide a significant amount of useful feedback to the Team to assist them with the completion of the integration phase of the work. In order for the work to be completed according to the schedule, it is recognized that a significant amount of work will need to done-in a properly prioritized manner-to arrive at a final SSC model. Prior to that time, the Panel would like to continue to review the development of the model prior to the review of the draft PSHA report. Suggestions for the elements of that review are described below under "SSC products for PPRP review." Also, the impact on the schedule will be important and we discuss this below in "Need for PSHA Schedule. 2. Need for PSHA Schedule Given that the preliminary SSC model is not yet complete, due primarily to the need to finish the ongoing data collection program, we anticipate the need to carefully schedule and prioritize the effort to first complete the preliminary SSC model, obtain additional SSC products and hazard sensitivity results (see below), finalize the SSC model, and document the PSHA report. Specifically, the elements of the schedule that we would like to see on the calendar are the following:

• Completion of the preliminary SSC model
• Delivery of the preliminary SSC model Hazard Input Document (HID) to the PPRP
• Finalization of the SSC model
• Briefing with the PPRP to review the final SSC model
• Delivery of the Draft PSHA report to the PPRP for review
• Review of the Draft PSHA report by the PPRP (minimum six weeks required)
• Delivery of PPRP comments to the Tl Team
• Delivery of Draft Final PSHA report to PPRP for final review
• Delivery of PPRP Closure Letter to PG&E 3. SSC Products for PPRP Review In order for the Panel to have a full understanding of the SSC model, we would like to request the following products be provided. We understand that all of these products are already part of the planning and deliverables anticipated by the project, but we would like to emphasize their importance to the Panel by listing them below:
• Recurrence curves for rupture sources, particularly for the Hosgri fault
• Implementation of the WAACY model for linked ruptures (Mmax ruptures); how do you arrive at b-tail and tail offset DCPP SSC WS3 PPRP Letter 04-01-14 Page 3
• Approach to the use of non-Poisson recurrence models, the logic tree distribution of equivalent Poisson rates, and their impact on hazard and uncertainty contribution
• Impact of logic tree branches for Mchar and Mmax on hazard
• Impact of categorization of rupture sources as either Mmax and Mchar
• Discussion of what is aleatory and what is epistemic (e.g., Mmax logic tree, versus aleatory rupture sources)
• Hazard sensitivity for all of the above, including running the Shoreline Fault Report model with the new Hosgri rates 4. Tl Team Action Items The Tl team did an excellent job discussing/summarizing each day's results as well as developing a list of action items required to finalize the SSC model. The PPRP endorses such an approach. Here, we review the Tl team's action items according to an overarching theme, not priority. The PPRP is NOT directing the Tl team with regard to which action item or scope of work needs to be completed; such decisions are the responsibility of the Tl team as they finalize the SSC model. It should be noted that some of the actions identified by the Tl Team relate to immediate actions that are needed to finalize the SSC model, other actions relate to documentation that will be provided in the PSHA report. We include both types of actions in our comments below. a. Documentation of Piercing Points. Documentation of piercing points for offshore fault systems and age models is required. Specifically, the Tl team should explain how the piercing points are used to constrain slip distribution along the fault with the full range of interpretations reported. When multiple piercing points yield different offsets and imply different rates, the Tl team should document how the geologic slip rate distribution is characterized along the fault. b. Document Use of ONSIP Results. After the SSC model has been finalized, the Tl Team should document how or if new ONshore Seismic Investigation Project (ONSIP) results are used to constrain fault geometry and locations in the Irish Hills. For example, will the dip of the Los Osos and San Luis Bay faults in the OV, SW, and NE tectonic models be constrained by the ONSIP data? c. Document Definitions of Styles of Faulting. The three proposed tectonic models (OV, SW, NE) entail a rather large range of rakes on some of the individual faults (e.g., the San Luis Bay and Los Osos faults). The style-of-faulting (SOF) categorization of a fault for purposes of applying GMPEs depends upon its rake. We recommend that the SSC Tl team coordinate with the GMC (SWUS) team to ensure that appropriate GMPE SOF classes are assigned to the faults, recognizing the SOF assignment for a given fault may vary depending upon which tectonic model it is participating in. d. Carefully document/compare with UCERF3. The PPRP agrees with the Tl team's action item to compare the slip rate models, linked rupture models and rupture participation rates to the corresponding UCERF3 results. The SSC model is based DCPP SSC WS3 PPRP Letter 04-01-14 Page4 on a more current data set for the local faults than is the UCERF3 model, so agreement is not necessarily to be expected. Rather, the objective should be to document the comparison, pointing out any important differences and explaining why they arise. e. Documentation of Slip Allocation and Budget. It is critical that there be complete documentation on how slip is allocated among the various rupture sources and various models to construct the final slip budget. The allocation of slip budget to various earthquakes in the final model will drive the ultimate shape/form of the MFDs, which are the basic input to the hazard model. f. Explain Differences in Hazard with that of the Shoreline Fault Report. It was clear during multiple/various presentations that the current assessment of hazard is consistently lower than that presented in the Shoreline Report, possibly based on updated information on fault slip rates. This is a significant feedback issue and will need to be understood prior to finalization of the SSC model, and will ultimately need to be completely documented. g. Age Model in the Offshore. The PPRP was pleased to see a coherent age model presented by various PEs and members of the Tl team for use in the assessment of slip rates for the offshore faults illuminated by the LESS studies. This represents an improvement over earlier presentations and indicates a maturation of the offshore age model that is now being applied in the assessment of slip rates. The PPRP has increased confidence that the final slip rates that will be assessed and completely documented by the Tl team in the final report will rely on a mature, defendable age model. h. Documentation of Hazard Sensitivity to Fault Models. The three primary fault models could represent different hazard levels at DCPP. It will be important to document the hazard sensitivity of these various models to establish whether one model represents a substantially higher hazard than others, and to be sure that all assumptions are well-founded and applicable uncertainties incorporated. Please do not hesitate to contact me if you wish to discuss any of our observations, comments, or recommendations. If it would be helpful, we would be happy to schedule a conference call with the PPRP to explain and discuss any of our recommendations. Sincerely, DCPP SSC PPRP Kevin Coppersmith, Chair Steven Day Neal Driscoll Thomas Rockwell DCPP SSC WS3 PPRP Letter 04-01-14 Page 5 Copy: N. Abrahamson, PTI W. Lettis, SSC Tl Lead DCPP SSC WS3 PPRP Letter 04-01-14 Page 6 Participatory Peer Review Panel (PPRP) Review of the Document: "SSHAC Level 3 Methodology, PG&E DCPP SSHAC Study DRAFT -Project Plan for Diablo Canyon Seismic Source and Ground Motion Characterization SSHAC Studies" Dated August 8, 2011 This document provides the PPRP's comments regarding the Project Plan for the DCPP SSHAC Level 3 PSHA. We have focused our comments on items that relate to the manner in which the study will be carried out and on clarifying the activities that will be conducted. We have not focused on editorial revisions that might be made to the document itself. Our comments are divided into General Comments and Specific Comments, given below. General Comments PPRP Participation. The SSHAC level 3 process permits a role for PPRP members beyond the formal workshops, i.e., involvement as observers at working meetings of the Tl groups. The draft project plan is silent on this additional involvement of the PPRP members. Rather than leaving this entirely to the initiative of the PPRP (as suggested at the Kickoff Meeting), perhaps there should be a mechanism for the project leadership and the PPRP to collaboratively identify opportunities for this broader PPRP participation and to add that to the Project Plan. Workshop plans. It is important that the workshops follow the SSHAC structure and numbering conventions more closely than is indicated in the current Project Plan draft, so that participants will have greater clarity as to their roles. In particular, Workshop 1 should be restructured to follow the SSHAC model and therefore focus on ( 1 ) identification of technical issues of highest significance to hazard. and (2) identification of available data and other relevant information. The current Workshop 1ab plan lacks this focus, since it includes proponent presentations and exploration of model alternatives (p.14 ). Workshop 1 should attempt to be inclusive with respect to data, i.e., should provide a thorough data review (including older data if they will used in the PSHA update) to ensure that all participants are "on the same page" prior to discussions of alternative models at subsequent workshops. To go beyond "data" in the narrow sense, to more broadly encompass relevant information, Workshop 1 should also include presentations on the simulation methodologies and their verification and validation. It also seems to us that it is appropriate to include presentations on relevant community models and products (e.g., updated Ground Motion Prediction Equations; regional seismic velocity and/or fault models, if relevant) and updates on ongoing data collection efforts that can be expected to provide relevant data within the life of the study (e.g., offshore seismic network deployment). If multiple workshops are required on these topics, it would be appropriate to designate them Workshop 1 a,b, etc. The subsequent workshops should be restructured to provide a clearer distinction between (1) those filling the SSHAC "Workshop 2" function of presenting alternative models and their technical bases, prior to development of preliminary models by the Tl teams, and (2) those filling the 'Workshop 3" function of presenting preliminary models and hazard calculations and receiving feedback. A clearer distinction is required because the participant roles are different in each case (for example, the PPRP plays an active role in the latter, but an observer role in the former). This would not preclude having multiple workshops of each type and accommodating multiple cycles of feedback, as deemed necessary. Specific Comments p. 1, 1st para.: It would help the reader to understand exactly what "update" means. The SSHAC NU REG (NRC, 2011) uses the term in a general way to mean any replacement, revision, or refinement to an existing PSHA. Based on comments at the Kick-off meeting, it appears that the intent of this study is to "replace" the previous PSHA. p. 2, 2nd para.: The sentence states that the DCPP study "will differ in several important aspects" from a traditional Level 3 study, but the three items identified are common to other similar studies and making a distinction is not necessary. For example. the PSHA, PVHA, and TSPA SSHAC studies for Yucca Mountain were all open to the public and attended by a variety of observers; nearly all hazard studies replace previous such studies and the SSHAC guidance says that assessment of hazard-significance is required for Workshop #1; and most hazard studies take advantage of an ongoing collection or data-analysis program that is conducted in parallel with the hazard study. Therefore, it is incorrect to state that these are important differences with other SSHAC studies; further, drawing such a distinction leaves the reader wondering what the significance of the differences means and whether the approach to be followed (said to be different from "a traditional Level 3 study") would be considered acceptable as a SSHAC Level 3 process. p. 3, 1st para.: Reference is made to a Figure 2, but it is not provided. p. 3, 2nd para.: Table 1 should be revised to reflect the actual time of the Kick-off meeting and any other changes that reflect the current schedule. p. 3, 3rd para.: Here and elsewhere, the NUREG should be referred to as NRC, 2011. Because the document is not a contractor report (i.e., NUREG/CR), it is NRC's intent for the document to represent the NRC staff's positions without attribution to specific authors within the NRC. Once the document is issued a NUREG number. it is suggested that the document identifier be used in the citation. Page 4, Paragraph 2, Last Sentence: I believe "transparent" should be added to the list of items that the seismic hazard study is expected to achieve. p. 5, 2nd para.: Somewhere in this section, describe the process for selecting the participants. What are the criteria and qualifications? Is past DCPP experience part of the consideration? For those participants with previous DCPP experience, indicate how the project leaders will ensure there is no bias or anchoring to previous interpretations and technical positions. For those with no SSHAC experience, how will they be provided with sufficient guidance to understand the essential steps and participant roles? p. 5, 4th para.: It is stated that the Tl Team "may have" a staff of experts, but the organizational chart shows an SSC Tl T earn Staff Support box, so the text should be consistent. It appears from the text that the Staff will not "own" the Tl Team's assessments, which would imply that they will not directly participate in the integration (model-building) process (e.g., identifying logic tree branches and assessing weights). Is this true? If so, that should be made explicit. p. 5, 4th para. (and elsewhere): As noted, NRC (2011) suggests that the term "ITC" be replaced by the two-step process of evaluation and integration, defined as:
• Evaluation: The consideration of the complete set of data, models, and methods proposed by the larger technical community that are relevant to the hazard analysis.
• Integration: Representing the center, body, and range of technically defensible interpretations in light of the evaluation process (i.e., informed by the assessment of existing data. models, and methods). It is therefore suggested that "ITC" and "the informed technical community" be removed throughout the text to help avoid confusion. The sentence in the paragraph should be revised to say: "As such, the Tl Team is responsible for ensuring: (1) that the various data. models, and methods proposed by the larger technical community and relevant to the hazard analysis are considered in the evaluation; and (2) that the final SSC and GMC models represent the center, body, and range of technically defensible interpretations." Page 5, Last Paragraph: To avoid any perception of bias. it should noted that the PTI and GMC Tl Lead is an employee (i.e., Norm Abrahamson) of the Project Sponsor (i.e., PG&E) but that the SSHAC process has sufficient checks and balances to avoid any conflict of interest (e.g., PPRP review of technical assessments and process). This discussion should be part of the suggested discussion regarding the criteria and process for selecting the project participants. p. 6, 2nd para.: Typically, members of the Tl Team are expected to play the role of evaluator experts and well as integrators (see Section 3.6.3 of NRC, 2011 ). As written, it appears that the evaluator experts will be "identified as needed on the project" and are somehow external to the Tl Team. It is suggested that responsibilities of the Tl Team be to assume the role of evaluator experts. p. 7, 3rd para.: There is quite a bit of discussion about observers in NRC (2011 ), including sponsors, regulators. public representatives, PPRP, etc., so reference should be made to that guidance. p. 7, 3rd para.: Consider allowing for observers to make statements or ask questions at the end of each day of the workshop; having to wait until the end of a multi-day workshop can be frustrating.

p. 9, 1st para.: Take care to not raise the issue of PPRP participation in the evaluation and integration process (see also 1st paragraph on p. 10) by saying that the "PPRP is involved" in the evaluation or integration process. The PPRP reviews those processes and maintains its independence throughout. Page 9, Paragraph 2: With respect to item (b), will the hazard sensitivity analyses be conduct for only the "exceedance frequencies of interest" or for all frequencies? Page 9, Paragraph 3: Shouldn't a statement similar to that at the bottom of Paragraph 4 be added to this paragraph? The sentence would read something like "The final logic tree (GMC V5) will be developed based on the feedback from the Resource experts and PPRP members." Page 9, Paragraph 4, Sentence 1: Later in the text there is no mention of an iterative GMC V3. V3 is described as being the final version. Page 10, Paragraphs 1 & 2, Last Sentence: Suggest that "working meetings" be included in the list of meetings in which the PPRP has an opportunity of being informed of project developments. p. 1 O, 4th para.: Is the Figure 2 cited that same as Table 1? Page 11, Paragraph 1, Sentence 2: The project plan is generally written in third person, but in this sentence and several other sentences throughout the text. the first person is used. The text should be consistently written in the third person. p. 11. 2nd para.: It is stated that. "The actual databases formed for the GMC and SSC studies will become part of the SSHAC documentation and will be made publically available." Is this actually what is intended? How will the data be made available? Are there plans for dealing with copyright issues, proprietary data, ownership releases, etc.? Is there a plan for a public portal to retrieve the data (e.g., website)? This was a major activity on the CELIS SSC project and deserves additional discussion in this Project Plan. Page 11, Paragraph 2, Middle: It is not clear whether the reference to "numerical [ground motion] simulations" is with respect to the NGA-west2 project or other ground motion simulations that will be conducted by others. p. 12, 3rd para.: There is no discussion of what the data evaluation process will entail. At the kick-off meeting, there was discussion about the use of Data Summary and Data Evaluation tables for this process, as in the CELIS SSC project. Any differences in the data evaluation process for SSC and GMC should be identified. Page 13, Task 4, Sentence 2: It appears from this sentence that only new data, analyses, and interpretations since the last update of the LTSP seismic hazard program are going to be presented at SSHAC Workshop 1. Since previous data, analyses, and interpretations were not conducted under a SSHAC Level 3 program, any previous data, analyses, and interpretations that will be used in the SSC and GMC logic trees will need to be vetted through the SSHAC Level 3 process in order to establish data needs and allow review by the PPRP and new members of the Tl Teams. p. 13, P' para. (and see General Comments): The title and description of WS1 blurs the lines between the typical WS1 and WS2 for a SSHAC Level 3 process (see descriptions in NRC, 2011 ). It is suggested that the descriptions be revised to more clearly define the purpose and activities of WS1, 2, and 3 to conform with NRC (2011 ). If additional workshops are needed, they can be tied to WS1, 2, and 3 by citing a, b, c, etc. Page 15, Task 4d, Bullet 3: GMC Model V1 should also be evaluated through a sensitivity analysis Page 15, Task 5, Sentence 3: Only "new information" is referred to as being presented at SSHAC Workshops 1 a and 1 b. Any old information that will be used should also be presented. Page 15, Task 5, Last Sentence: This is where it gets confusing regarding which version of the GMC logic tree model is being used. It is not clear whether the GMC logic tree model is being evaluated at the same time as the SSC logic tree models (i.e., there is no mention of the GMC model). Is only the SSC model being evaluated and, if so, why? Page 16, Task Sb, SSC, Bullet 1: There is a question that needs to be resolved for the final version of the Project Plan. Page 16, Task 6: Title and text refers to GMC Model V3 as the final model, whereas previously it was stated that V4 would be the final version. Page 18, Task 7: Under item (1 ), the GMC model should be included along with the SSC model? p. 19. 3rd para.: There is no discussion about developing a Draft Report. I assume that the project will want to received comments from the PPRP on a Draft prior to developing its final comments. Page 20, Paragraph 1: NRC (2011) should be referenced along with Budnitz et al. (1997). p. 23: Please ensure that the dates and topics in this table are consistent with those given in the excel schedule (which should also be made part of the Project Plan). Also, there are random comments in the table that presumably should be deleted.

Page 23: (a) The note identified by the"**" needs to be done. (b) The list needs to be formatted in a consistent manner. (c) The PTI, Tl staff, and Hazard Analyst should also be listed as attendees at all of the workshops. Page 24: The note identified by the"***" needs to be done. Page 25, Workshop 28: Under the list of Attendees, what does "Down" mean? Page 26, Workshop 3: The "SSC & GMC" before "Workshop 3" should be deleted. Pages 27 & 28: Figures 1 and 2 are missing. February 13, 2012 Kevin Coppersmith Chair DCPP PPRP

Subject:

Response to PPRP comments on Workshop #1

Dear Dr. Coppersmith:

Thank you for the comments, dated December 13, 201 l, on Workshop #1 .Our responses to the comments and recommendations are given below. Norm Abrahamson Chief Engineering Seismologist Pacific Gas & Electric Company Response to Comments 1. Update Project Plan The Panel recommends several steps that should be taken by the project and then documented in an update to the Project Plan. These are summarized here: -The Project Plan should clar((v the role deterministic analyses in the sensitivity analyses, in defining the sign(f'icant issues, and ultimately in identffyi11g the data compilation a11d data collectio11 activities. Response: As noted at the workshop, both deterministic and probabilistic approaches will be used in the seismic hazard update for DCPP. This is consistent with the current License Amendment Request that was submitted to the NRC. We agree that the use of the deterministic method in defining hazard sensitive issues needs to be defined. The project plan will be updated to clarify the role of the deterministic analysis. The revised project plan will be submitted to the PPRP by March 31, 2012. -The schedule.for WS2 and working meetings between now and WS2 should he estahlished as soon as possible to ensure that all participants have adequate opportunity to work these dates into their schedules. For example, in discussions with the TI Leads, it was stated that WS2 would not occur in June but rather in November 2012, but that the June date would be held for a working meeting of some sort. We suggest that the June working meeting include the emire PPRP as observers so that an entire year does not pass between now and the next inte1.face with the project. Response: The schedule for WS2 and the working meetings have been set. Workshop #2 is planned for Nov 5-9 (starting Monday afternoon and finishing Friday noon}. A list of working meeting dates was sent to the PPRP in January. They are repeated below: GMC Working Meetings in 2012 March 19 (1-3 pm at PG&E) May 30 (1-3 pm at PG&E) June 19-20 (9-5 pm at PG&E) July 18 (1-3 pm at PG&E) October 8 (1-3 pm at PG&E) SSC Working Meetings in 2012 SSC TI Team Working Meeting 58 6 7 8 9 10 Date 01/11/2012 01125/2012 02/13/2012 03/12/2012 03128/2012 05/14/2012 Venue PG&E SFGO -CR 407 PG&E SFGO -CR 407 LCI -Walnut Creek PG&E SFGO -CR 407 LCI -Walnut Creek PG&E SFGO -CR 407 I I 06/ 19-06/21/2012 PG&E SFGO -CR 407 12 07/09/2012 LCI -Walnut Creek 13 08/13/2012 PG&E SFGO -CR 407 14 09/13/2012 LCI -Walnut Creek 15 10/11/2012 PG&E SFGO -CR 407 16 12/10/2012 LCI -Walnut Creek Workshop #2 Nov 5-9 at Embassy Suites, San Luis Obispo -The project should consider having a representative.from the SSC Tl Team attend GMC working meetings, and vice versa. Response: Agreed. This will be done for future working meetings. -One or more represenlativesfrom the PPRP should he invited lo each f?{fhe working meetings to al/end as ohservers. For this to happen, the PPRP must he in.fhrmed <?[the meetings asfar in advance as possihle. Response: The PPRP is invited to send a member to any of the working meetings. It is up to the PPRP to select which working meetings to attend and which PPRP member should attend. The schedule of working meetings is provided above. We will inform the PPRP of the agenda for each working meeting prior to the meeting. -We recommend that parallel sessions not he used in.future workshops. hut that the SSC and GMC session he held The SSC and GMC participants can attend their own workshop and depart. but the Tl Leads and the PPRP should attend both sessions. Response: Agreed. Workshop #2 will not have parallel sessions. We have extended the workshop to start Monday afternoon and end Friday at noon to allow for the parallel sessions. The relationship between the Tl Staff and the Tl Team need<.; to he clarffled. What is the distinction? Who will he building the models during the integration part <?f the pr<?ject? Response: The Tl team members have ownership of the SSC and GMC logic trees. The Tl team staff provide technical support for the Tl team and will participate in the discussions at the working meetings, but they do not have ownership of the final model. This will be clarified in the updated project plan to be submitted by March 31, 2012. 2. Workshop Attendance and Participation To ensure that the appropriate expertise is present.for workshop discussions, we recommend support.for all participants.for the entire duration q(their respective portion qf'the workshop (i.e., GMC or SSC). Thus, a proponent expert participating in WS2 would be provided support to attend not the day qf their presentation, hut also the remaining days o,ftheir respective portion o,f the workshop. Response: Agreed. The resource experts will be asked to attend the full workshop, with compensation provided for the additional days. 3. Summary at the end o,feach technical session Interaction between TI team and experts during workshop meetings is a key component C!fthe SSHAC Level 3 Process. To.foster more interaction. the PPRP recommends that a session summary he made at the end o,feach session hy the TI Lead with input.fi*om the entire TI Team and all attending experts. {fapplicahle, it is also recommended that prioritization of any potential future project activities (e.g., gathering new data, conducting new analyses) be part C!f the summary so that input.fl-om the TI Teams and workshop participants can be discussed and considered. Response: Agreed. At future workshops, an initial prioritization will be discussed during the workshop to gain from the resource/proponent experts views and to also avoid giving the impression that all the tasks discussed will be funded. 4. Inclusion or Exclusion l!f Interpretations It is important that the Tl Team communicate a clear and consistent policY,for the inclusion o,f SSC and GMC models. At least one statement during Workshop I posited that ff an interpretation cannot he rejected then it will be included in /w::,ard models. The PPRP notes that the SSHAC guidelines, as ampl(/ied by the draft NUREG on SSHAC Level 3 and 4 implementation, stipulate only that "technically defensible'* models be included, and we recommend holding strictly to this concept. Response: Agree. The project plan will be modified to make it clear that only technically defensible interpretations will be included 5. Participation o,f TI Team Members The TI team members are. without exception. highly capable sciemists and engineers who, together, bring the expertise.for a success.fl.ti prl!ject. Notab(v. though. their level is roughly bimodal. with some members having two to three decades o,f experience in seismic hazard studies, and the rest being at much earlier career stages. The involvement o,f the latter cohort is a very positive developmem that we commend. However, this circumstance does place an added responsibility upon the TI leads. It will be incumbent upon them to elicit the .fi1ll and independent voicing C!l views by all team members that is necessary to provide high that no individual cognitive biases dominate the process. Response: As noted, there is a wide range of experience in the Tl teams and one of the goals of this project is to develop younger people that can lead Tl teams in the future. We will encourage the younger members of the Tl team to participate fully in the discussions at both the workshops and the working meetings and to question the recommendations of the more senior Tl team members. The more senior members will actively work to engage the younger members in the discussions and evaluation process. This will be a continuing challenge for the project and should be carefully watched by the PPRP. 6. Data Needs or Gaps Particularly in the SSC element the project, a large number data gaps and data needs were identified, along with a host studies that could be conducted to address data needs. As noted by the SSC TI Lead, the project resources will not he sidficient to conduct all C?f'the studies ident(fied. When identfjjJing additional data needs or data gaps to address sign(ficant issues or uncertainties, we recommend that this he an exhaustive process that allows.for prioritization and decision-making. Speqfically. it is recommended that the process include a.full inventory andjust!flc:ation gaps, realistic costsfor acquiring new data, and design plans.for data acquisition. Furthermore, in areas where data already exist, an explanation should he given for why the existing data fail to address sign(ficant issues and uncertainties. Response: Agreed. The justification for the new studies will be made and documented. In particular, we will continue to ask the question "what are the short-comings of the existing data and what are the uncertainties that are caused by the short-comings?" 7. Data Jnve11t01y and Documemation There is a need to establish a process for identffying those data that were considered and used in each model element for the project. As noted in NRC (2011): It is important to document and inventmy all data that were considered in the course of the project including those data that were not used. For those data that were relied upon, it is important to also document the manner in which those data were used. "Spec(fically, there needs to be complete documentation process of data evaluation, and which data were considered, and ultimately used to construct each element the.final seismic hazard model. Response: Agreed. We plan to use the data table approach developed in the CEUS-SSC study to document which data were used and which were excluded. Data tables will be prepared for both the SSC and GMC. We will include an Attachment to the Project Plan that includes a description of the data evaluation and documentation process with an example of the Data Evaluation Table. 8. Interim documentation and review We recommend that key intermediate products he documented in writing and reviewed hy the PPRP. For example. the PPRP would welcome the opportunity to review.fi!lly documented data collection plans, which should include (1) the relationship efforts to reduction. and (2) the rationale.for their prioritization. Response: The rationale for the prioritization of data needs and descriptions of the planned studies will be provided to the PPRP for their comment.

9. Data Availability We recommend that all data acquired or used to develop a model or imerpretation he made publically available as soon as quality control is Such a policy will allow the public and the scient(fic community to acquire/review the data and develop alternative models in a timely manner. It will also make the SSHAC process accessible and tramparent. For example, during the course of the project, r£ferences used in developing models and interpretations could he collated into a master reference list and made available. Also, a PDF database for all references could he developed a11d made available to the TI Teams a11d StaJJ: as well as the PPRP. Response: We agree that there is value in making the data sets publically available as soon as the QA is completed. The decision regarding how the different data sets will be released has not been decided yet. Data collected under the AB1632 program may have different reporting requirements. Any PG&E data sets that are presented at workshops will be made publically available before the workshop. 10. Imerface issues The Diab lo Canyon SSHA C study has some characteristics that affect the scope required collaboration between the GMC and SSC teams. For example, the SSC team may have to consider logic-tree branches involving a range f?f"single-and multi-segment rupture models.for the Hosgrifault, the possibility Shoreline splay faulting, and a considerable range <?[scenarios.for the Los Ososfauft to accoum.for dip uncertainty. It is important that key scenarios be communicated to the GMC team at an early stage, in order to permit the latter to undertake an adequate integration of data and empirical and numerical models for those scenarios. As another example, the project makes sign(ficant use f?f"dynamic rupture modeling to address DCPP issues such asfault branching and hanging-wall ampl{fication. Dynamic modeling will create new SSCIGA1C inte1.face issues beyond those that customarily arise in kinematic modeling (for example, a critical component of the.fault branching problem is the orientation principal stresses, which are not required.for kinematic modeling). A third example relates to the scale of the seismic velocity and attenuation models, as high-resolution models may provide importam constraints for ground motion studies. While scale structure will be important.few SSC issues (e.g., seismotectonic studies). geologic variations on the scale afew kilometers or fess may carry information relevant to GMC (e.g.. i11formation on the crustal qualityfactor (Q) around the DCPP site that may heljJ to address the question: Could the high DCPP site kappa he due to a low-Q path? In order to ensure that these sorts of inteiface issues are adequately addressed and results communicated, we recommend that SSC working meetings be attended by some member(!l) the GMC group. and vice versa. Response: Agreed. l I. Comprehensive Simulation Validation Plan The GMC Tl team proposes extensive use f?f ground motion simulation, hoth kinematic and dynamic. to help characterize ground motion at DCPP, including the median motion.fl'om nearby/emits, the hanging wall q{fect, the directivity effects, and the near-:.fleldfling velocity pul<>e. Validation is a critical process to assure that a particular simulation method is sound and its results can he trustedfor use at DCPP. Validation o.lsimulation methodology was discussed at WS 1; however, the discussion focused mainly on the near-fault median motion. The PPRP recommends that a comprehensive validation plan and validation rules be established by the project that will cover the full set ojfeatures to be used in the project by the GMC TI Team. This validation plan should cover hoth the kinematic and dynamic modeling. Response:. We agree that the validation plan should cover both kinematic and dynamic modeling, but we do not agree that the validation should not be focused on the near-fault ground motions. These near-fault ground motions dominate the hazard. We do not want to be distracted by issues that may arise for distant earthquakes. For example, ground motions from large magnitude earthquakes at large distances may be dominated by wave propagation effects that are not significant for the hazard at DCPP. 12. Epistemic Uncertainty in Ground Motion Estimates It is important that the epistemic uncertainty in the ground motion estimates adequately represent the center, body, and range the defensible interpretations. Although the PPRP acknowledges the importance the empirical NGA ground motion prediction equations (GMPEs), it is critical that all relevant data and models, 11otjust the NGA models, he considered in developing the median, standard deviations, and epistemic distrihution o,j'ground motion estimates. This should include relevant ground motion data and GMPE'lfimn similar tectonic regions.fl*om around the world as well as ground motion simulations where empirical data and models are insuj.ficient in characterizing all of the representative earthquake scenarios, whether prohahilistically or defined, that will he proposed hy the SSC team. Response: Agreed. Applicable data, GMPEs, and simulation methods from other parts of the world will be considered in developing the range of ground motion models for DCPP.

January 16, 2013 Kevin Coppersmith Chair DCPP PPRP

Subject:

Response to PPRP comments on Workshop #2

Dear Dr. Coppersmith:

Thank you for the comments dated November 11, 2012, on Workshop #2. Our responses to the comments and reconunendations arc given below. 1£,,1"" (}Jvft<<t.A(..-.J Norm Abrahamson Chief Engineering Seismologist Pacific Gas & Electric Company p. 1 Response to Comments Our responses to the PPRP's comments and recommendations are provided below. We have attempted to respond to all of the PPRP comments; the explicit PPRP comment is shown first in italics, followed hy our response. Please do not hesitate to contact us if further clarification is required, or if we have inadvertently overlooked a comment requiring a response. Gene1*al Observations ln swm1U1JJ'* this was a11 excellent workshop and it adhered lo the requirements outlined in NUREG-2117.for a SSHAC Workshop #2. We agree that Workshop #2 was successful and provided important information for the Evaluation phase of the SSHAC process. Specific Comments and Recommendations 1. Project Schedule The PPRP recommends that a detailed schedule.for all working meetings, Workshop 3, deliverables, and other key activities be updated and issued by project management in tlze fonn of an updated Project Plan. As requested, we have updated the Project Schedule and are revising the Project Plan. A copy of the updated Schedule is attached to this response: and a copy of the updated Project Plan will he provided to you upon completion. At Workshop 3, the PPRP plays an active role and the preli111i11c11y model will he presented. Accordingly, Jhe PI'RP requires sufficient time to review the data evaluation and integration process, as well as the details of the SSC model. For the process to be effective, documents that describe the evaluation and integration processes need lo be provided to tlze PPRP in a timely fashion well in culvance of the worhhop. It is the Panel's understanding that the TI Team is i using data summmy and data evaluation sheets to document the data, models, and methods thaf: are being reviewed during the evaluation phase o,f the pro,ject. These data tables need to be completed by the 11 Team when the data are examined prior to lhe model building process. In addition to the data tables, the PPRP would like lo request a copy of the Hazard Input Document (HID, see NUREG-2117, Section 4. 7. 2) and any other documents that will describe the preliminalJ' SSC model. We agree with the need to provide adequate review time prior to Workshop 3. As per the attached schedule, we plan to provide the PPRP with the data evaluation and source sununary sheets and a description of the preliminary model (our logic tree model V2) two months prior to the workshop. As requested, an IIID will be provided to the PPRP prior to the workshop with sufficient time for a review. However, we envision suhmitting the HID of the preliminary model to the PPRP one month prior to the workshop following the submittal of the data evaluation, source summary sheets, and description of the logic tree model V2. p.2' We request that at least one member of the PPRP participates as an observer in the working meetings throughout the model building process leading up to WS3. As discussed in NUREG-2117 We agree. As shown on the project schedule, we plan to convene one formal Working Meeting per qua11er for the duration of the project. We will plan to notify the PPRP in advance so that at least one member of the PPRP can attend all \Vmking Meetings. The PPRP will be notified if additional fo1mal Working Meetings are added to the schedule and we will make every eff01t to make sure a member of the PPRP may attend. 2. Strategy for Recurrence Model Assessmem of the impact of using different recurrence models turns out to rank at the top of the tornado diagram in terms of hazard significance. The 11 team needs to develop a clear strategy on how to deal with non-Poissonian models in light of the fact that it is 1111/ikely that we/1-resolved information 011 the slip rates and timinK of past earthquakes on the fault zones will be available, which are critical to the hazard asse.\*sment at DCPP. Specifically, use of renewal models requires information on the recency and rate of activity of a specific fault and these types of data are not likely to be forthcoming in the time between now ,ind when WS3 is conducted. Tire Tl team will therefore need to develop 'md defend a model with large uncertainNes that 11wy have significant impact on the hazard to DCPJ>. Alternatil'ely, the TI team may wish to reconsider the use of non-Poissonian models, as it is clear.from lonK paleoseismic records in California that earthquake recurrence has demonstrably large coeffidents of variations and there is not a clear benefit in moving away from the srate-of-the-pmclice of using Poissonian recurrence distributions. We agree that the TI team needs to develop a clear strategy for addressing recurrence models as this appears to be one of the larger sources of uncertainty based on the tornado diagrams. However, we do not agree with the PPRP suggestion that there is no clear benefit to moving away from following state-of-the-practice and only using Poisson models for recurrence. Using only Poisson models is not consistent with the objective of capturing unce11ainty in the center, body and range of teclrnically defensible interpretations for source characterization. Lack of data is not a valid reason to reject alternative approaches lo model recu!Tence. Lack of data should lead to larger unce1tainty, not less uncertainty. Assuming a Poisson model because there are not enough data to constrain non-Poisson models is equivalent to saying that there is no uncertainty in the recutrnnce model. This approach will lead to increasing unce1tainty as mOl'c data arc collected. For example, if we only consider Poisson models as alternatives to Poisson models for faults in regions with abundant of data and only use Poisson models for regions with sparse data, then unce11ainty is systematically underestimated for regions with sparse data. The logic tree for regions with sparse data should be broad enough so that additional data collection in the future will lead to a reduction of uncertainty, not an increase in uncertainty. p. 3 If non-Possion models are a technically defensible interpretation for the behavior of fa.ulls or regions, then these models should be captured in the range of models developed by the TI team. The approach (or strategy) discussed in workshop 2 is to address temporal variations in the rate of seismicity due to renewal models or other causes by applying a scaling factor to the Poisson rate. In this case, the Poisson model will be used as the base-mode1, and the non-Poisson models will be captured by the range of scaled Passion models. The lask for lhc TI lcam will be to justify the range and weights for the scale factors that are applied. J. Strategy for Consideration of Research Projects Tire workshop pmvided an excellent opportunity for the Tl Team to understand the data, models, and methods that the larger technical community ;s using to characterize seismic sources in California. Jn most cases, the presentations and discussions involved research-oriented activities and initiatives (e.g., UCER.F3) tlrat are designed to (l) push tile state nf the art and (2) to provide input to regional seismic hazard studies. We suggest that the Tl Team develop a strategy for how they will evaluate these other efforts and what elements of those studies are applicable lo the site-specific SSC model and PSff A at the Diahlo Canyon site. For example, much of the discussion at the workshop surrounding tire concept a/segmentation resulted in the general agreement among the participants that the tool is used when high-quality behavioral data along a fault can be gathered and analyzed. There is Ii/lie prospect that such data can be gathered for the Hosgrifimlt, so a stratem1 will be needed for how the segmentation tool can be usecl, if at all, for tire DCP P SSC model. Similarly, the UCERFJ Grand In11ersion Clllempts to inco111orate various types of fault-specific information for the ma;orfaults of California and to inco1porate a wide variety of rupture scenarios within the constraints provided by issues such as moment and slip balancing. To what extent can the UCER.F3 model provide re/;able estimates of SSC parameters/or thefi111/ls in the DCPP area? Tf the UCRRFJ model is not judged to have suj}icient resolution to provide direct information 011 the local fimlts, should the conceptual models embedded in the UCERF3 model be adopted locally for DCPP? (e.g., local moment balancing, soft segmentation points resultingfi*om slip rate differences). Because the UCERF3 model is regional and has been designed to provide regional seismic hazard, should it be used at all as either a direct inplll or e11en to inform the DCPP SSC mndel? These are all issues that we suggest need to be included and in the development of an o\lerall strategy for the SSC model. We agree that a clear strategy needs to be developed and aiticulated regarding how the stawide UCERF3 model is considered in the site-specific DCPP SSC model. The PPRP commei1I describes some of the concerns with the UCERF3 model and its applicability for a site-specific investigation. We know, for example, that the UCRRF3 model inputs do not adequately capture the uncertainties in fault source geometry and fault slip rate for the four primary faults contributing to hazard at DCPP .. Fm1hermore, we agree that the Grand Inversion is best suited to characterize major California faults with abundant paleoseismic data, and that it may provide less meaningful results to the short, low slip rate, relatively data poor faults of major interest to DCPP. However, many of the concepts and approaches developed by the UCERFJ effort (available as appendix repo1ts to the overall UCERF3 report) contain valuable infom1ation regarding multi-segment and multi-fault mptures, and the solution files to the UCERF3 model contain insights into the possible behavior of mulli-segment and multi-fault ruptures that need to p.4 be evaluated and considered. Thus, our plaru1cd approach is to Jay out the strategy for considering the UCERF3 model for Diablo Canyon in a "white paper" that can be provided to the PPRP as part of the data documentation deliverable prior to workshop 3. Jn summary, the range of uncc11ainty in the final SSC model should capture the aspects of the UCERF3 model that are considered to he applicable to the DCPP region. This may he achieved without directly implementing the UCERF3 model in the final SSC logic tree, but by selectively incorporating philosophies imbedded in the UCER.F3 model oflinked fault rnptures. 4. Full participation of All Members of the Tl Team

• At the workshop, four out of the five members of the TI team were fully engaged in the discussions. All five memhers need to be fully engaged and up lo speed on all issues related to the SSC model as any member may be called upon in J'.fSJ to defend or explain aspects of the model. In other word{j, all .five members need to take complete ownership of all aspects of the model .... If not all team members possess the attributes requiredforparticipC1tion on the Tl Team, the TI Lead should consider replacing those members that do nnt. Time is short and all members will need to he fully engaged to make the deadlines laid out in the project plan. Given the nature of the evaluations that lie ahead for the Tl Team, it may be prudent to include a memher with e.\pertise in geophysics and seismology. We agree that all members of the Tl Team need to be fully engaged in the Evaluation and Integration process, including full participation at each Workshop. The member of the TI Team that was not engaged in the discussions has agreed to step down from the TI Team. A replacement for this person has not yet been identified. Regarding the PPRP recommendation that we consider a membel' with expe11ise in geophysics and seismology, we have discussed adding Glen Biasi as a TI Staff Supp011 person. Dr. Biasi may move into a full TI Team member depending on his time commitments and ability to "catch up" with the current TI Team's progress in the Evaluation process. 5. Strategy for hazard model development The workshop did a ve1J> goodjoh of reviewing relevant research onfimlf behavior. There is clearly a KJ'Oll'ing recognition thaf a m11/tiplicity of rupture modes is possible on the regionC1/ fault system in California. For example, ruptures may linkfiwlts in a great mnnher of-ways. A rupture may nucleate on one fault and transfer to other faults, even to faults of differing senses of slip. Critical points on faults (e.g, fault intersections and splays, stepovers, etc.) may sometimes become rupture endpoints, sometimes not, with probabilities that are still poorly understood. The project is therefore faced wilh a number of chclllenges: (I) Research 011 rupture modes such tis that being conducted under UCRRF-3 is at a regional scale, and only indirectly informs model buildinf{ at the local scale relevant ro the SSHAC study. (2) For the most part, the data required to apply those ideas are absent in the central coast region (e.g., reliable slip rates and timinf{ of pas/ rupture.5.). (3) That research is rapidly evolving. (4) It is possible that these complex multifault rupture models may raise significant i1Ue1face issues when translated into ground motion models. (5) Given the very large numher of potential linkaf{es, end points, and segmentation models, a hazard model could quickly become unwieldy and incomprehensible. p. 5 The PPRP rherefore recommends tltat tlte Tl team develop, al the outset, a clear strategy.for co11str11ction of a workahle hazard model. Some elements that should be considered: (!) llazard sensitivity may be an important element of that sh*ategy. While all technically defensible models must be evaluated, it will prohahly he possible to eliminate some model complexities early in the evaluation pmcess by documenting an absence of hazard significance. (2) The team needs to establish a clew* cut<:?[( on the consideration of emerging research results. (3) The strategy should consider potential ground motion inte1face issues. For example, ruptures that linkfiwlts wUh different senses of slip may raise substantial new problems when translated into ground motion modeling. We agree with the PPRP comment that the complexities of some of the source models discussed at Workshop 2, such as complex multi-fault ruptures, could he difficult to impkment in the PSHA calculation and also may not have a significant effect on the hazard. As recommended by the PPRP, hazard sensitivity sludies will be used to eliminate some model complexities that are not significant lo hazard and to justify simplification of the source modeJ. The Tl Team will evaluate if the standard form of the models can be used to capture the key aspects of the SSC. For example, a hazard sensitivity study will be conducted to dete1mine if using a large number of individual complex multi-fault ruptures leads to significantly different hazard than using a more limited selection of ruptures that captures the range of uncertainty implied by the complex models. As noted by the PPRP, lhe interface between the SSC and GMC Tl Teams will be critical for implementing various issues of complex multi-fault ruptures with mixed mechanisms on different segments. We will start with a simple approach of using bounding cases, such as using pure strike-slip and then pme reverse slip for a multi-fault rupture that involves both strike-slip and reverse-slip segments. If the rates of such complex rnptures are low, then there will not be a significant effecl on hazard and a simplified approach can be used. If thcre is a significant effect on hazard, then other methods, such as using finite-fault simulations will he used to develop an appropriate method to address the interface issue. 6. Data Tables All data that ltave been evaluated by the Tl Team should be documented ;n dara tables such that the Team can represent !he center, body, and range of technically defensible interpretations the model building process. Accordingly, data summary and evaluation tahles should ro be completed when data are examined and evaluated. Evaluatfon entails a mrmber of activities idenf{fying important technical issues cmd tlte ability of the data to address those issues, as well as evaluating the data in terms C?f their quality and relevance to the assessments being made. integration is model building to arrive at a defensible expression of knowledge and uncertainty of the inputs to the model, due consideration to the available data. This includes the full expression of the model elements (logic-tree their relative weights, and tire range C?f credible uncertainties. Docmuenlation of data evaluation and integration is one of the most important parts of the SSHAC process; it should be pe1formed concurrently with model building. The PPR P needs* timely access to this documentation throughout the model building process in order lo pe1form independent evaluation p. 6 We agree thal documentalion of the data evaluation process is an important element of the SSHAC process. The TI Team is prepa.l'ing both Data Evaluation and Seismic Source Summary tables that document the data evaluation process and use of the data in the integration and model building phase of the project. These tables are being prepared concurrent with both the Data Evaluation and Integration Model Building phases of the prqjcct, and will be available to the PPRP for independent review. 7. Lexicon of Terms During the course of Workshop 2, it became clear to the PPRP that key proponent experts were using terminolozy that had a different meaning for different people. As an example, the term fault segment" was used by one expert to imply that a section or sections of a fault alw<1ys ruptures together, whereas others used the same term to represent a change in the style or rate of faulting, a change in fault geomefly, or some other aspect of the fiwlt as a way 10 describe different secrions of a fault zone. This causes confusion among the project participants, as well as among outside observers, and could be easily corrected by development of a lexicon of key terms that are used in this s111dy. The PPR P recommends that such a lexicon of de.fin it ions be developed/or key terms that will be used in the models and reports completed for this project, and that this lexicon be distributed to the appropriate expel'fs lo c1ssure common understanding of key issues. We agree. A lexicon of terms or glossary will he developed for the prqject. 8. Site-Specific SSC Model Acknowledgh1g the excellent cross-section of SSC talent brought to the workshop fiwn the larger community, the Panel notes that nearly all of the participants come.from the research community and are involved in regional seismic hawrd studies that are not intended to be used for site* specific use and certainly not for use in evaluating the seismic design of nuclear power plants al low annuaJ.fi'equencies of exceedance. Although many of the basic seismic source characterization issues are common to both regional and local I'SHAs, there are unique issues that come info play for site-specific studies that the TI Team will face, but could not be culdressed by the participants at the workshop specifically. For example, detailed modeling of fault geometries in the vicinity of the plant site will be important and local constraints on potential models of ruptures that email fiwlts huving different senses may need to be considered. Practical ways of deciding upon the fault-specUlc selection of applirnble magnitude fi*equency distriblllions, and decisions regarding appmpriate ways of the epistemic uncertainty in recurrence behavior *will need to be considered. These are issues that have been addressed to some extent hy others who have developed sife-spec{fic SSC models for nuclear facilities. ft is suggested that the Tl Tewn consider the models and developed by other resource experts having site-fjpecific PSHA e,,perience. That experience nwy provide the ream H1fth additionc1I insights and practical approaches that have been used to address common problems. p. 7 We respect this observation from the PPRP, and \.Viii take your suggestion to consider other specific SSC models for nuclear facilities into consideration. However, we ofter the following response: (1) Development of the SSC model involves both an evaluation of the current status of knowledge within the scientific community on issues related to seismic source characterization (e.g., status of the C,B,R of TOI for segmentation, multi-fault rnptures, recurrence models, geodesy, etc) as well as an evaluation of approaches/methods for implementing this infomiation into an SSC model for input to a PSHA. We designed Workshop #2 and invited Resource and Proponent Experts to explicitly discuss both of the above. (2) In terms of generic site-specific SSC models for nuclear facilities, between the Tl Lead (William Lettis) and TI Support Staff (Kathryn Hanson), the TI Team has the experience of approximately 90% of the SSC models developed for nuclear facilities over the past ten years. In addition, the technical community of individuals with experience developing SSC models for nuclear facilities is relatively small. We also invited Dr. Robert Youngs to attend Workshop #2 to discuss various implementation approaches, but he was unable to participate. In addition, similar to other SSHAC Workshop #2s where the USGS model and approaches were discussed, we fully explored the UCERF3 model, and the TI Team is participating in other working meetings to discuss how the UCERF3 model will be incoiporate<l into the National Seismic Ha7.ard Map as well as how the model may be adapted for site-speci fie use. (3) In tenns of site-specific models of relevance to Diablo Canyon, there is only one -the SSC Model developed for the PG&E J .TSP (PG&E, 1988). This model was fully explored and updated at the meeting by various Proponent Experts involved in the f.TSP model. 9. Aleatory Approach to Segmentation The discussions of fault segmentanrm at rhe workshop provided a valuable range of viewpoints on the issue and served to highlight not 011ly the differences in models, but also the potential approaches that the Tl Team might take as they mnve f01ivard constrncting their SSC model. It is clear to the Panel that the community has moved away from considering the alternative segments that might result fi'om a given segmentation model as epistemic alternatives toward a more aleat01y model that includes the occurrence of a wide range of rupture scenarios at their applicable relative frequenlJ'. For example, the presentation by Glenn Rias; and comments by Sieve Wesnousky reinforce the notion that a ve1y wide range of possibilities are observed/or possible controls of rupture segments, but it is more fi*uitful to consider the relative fraction or frequency with which those controls might limit or extend the ruptures. We suggest that the Team consider moving toward this type of aleat01y tre(lfment of altemarive rupture scenarios-one
• that might include (I number of credible scenarios each with its relative frequency of occurrence. lt is also suggested that the Tecm1 consider the rupture case hislories discussed at the workshop relcttive to the specffic rnpture scenarios that might be included in the SSC model. For example, the Denali earthquake appears lo have 1111cleated on a relatively small thrust fa11lt, with rupture then propagating onto the main strike slip Denali fault. This event and others like it might serve as potential analngs for the relationship between the fiwlts that appear to merge with the Hosgri fault. Likewise, the workshop highlighted the value that might come /mm considering the orientation of principal stresses relative ro the orientation of faults as they change trend. These and other case histories could provide a basis for the consideration and selection of credible and defensible rupture scenarios for the SSC model. p. 8 We agree with the PPRP observation that it may be more appropriate to model earthquake rupture scenarios as an aleatory unce11ainty with an assessment of their applicable relative frequency of occurrence. We wiJl incorporate this concept into our SSC model. The TI Team is developing approaches to inco1vorate the full range of unce11ainty in rupture models into the SSC model. We also agree that earthquake rnptures such as the Denali rupture (also the I 950 Kern County rupture) during which both strike slip and reverse slip occurred may serve as analogs for the Hosgri fault and neighboring faults in the Diablo Canyon region. These past ruptures are being used by the TI Team to inform our assessment of possible rnpturc scenarios for the SSC model. p.9

"'? _. 0 Tm 1: Prop..v.illon of Draft Pl:ln """ ln111.11 Sor>SIUVl!y ANIY'JS Taolc2; W011<$Mp 0 (Kick.off MooUna) J; Ev31uatton Ta*k 4: Workollop 1 -Slgnlftc:.:lnl b!luo11.1 Av41Ual1to Dat.:t, .,n<I D:IQ Nood*: Mod"I VO S<rnSIUvlry 5: O;,t:i Evll!u1>t1on and ntOD,..IOn Jor SSC Son"d*llY I.ogle roe a; Workshop 2 -Pro.,.,,,ent MOClelO, SSC MO<IOI VI Snn>ltlvll)' r .... 7: Dab EvOIU3tlon *r>a ln"'ll""'on for SSC Model V2 T3Sll ll: Wotbllop 3-lbmrd Fo.-!b:lctc WorkshOp :Z.S-27. SSC MO<lct V2 H>brd Ta*k 9; Oa\/olop Fl..,I Model: SSC MOf!ol VJ 31\d R01>0rtln11 T.>*k 10: ,ln*I Pl>lll' !WvloW ... a Sul>mlb:ll 5 Figuro 2 -Olablo Canyon SSC project $Chedule 2011 2012

• I 10 I 11 I u I 1 I ' I 11111 I *: I 1 I : .. * -:_,;I: 2013 'I 1tl u 11211 Ongoing PG&E Program Notes 1 -SWUS GMC 1 2 -seismic SllJ:ly letter re:iort. :>11.-..<;e : I 3 -L TSP Briefing (resulls of on9oin9 SSC studies) 4 -Ottsnore low*energy seismic studies letter repc11 5-SWUS GMC WnooMp2 6 -Ol'ISnore seismic study letter report, phase 2 7 -Prelimioary SSC mot!el V2 to PPRP e -SW..JS GMC WOntshop J 9 -Final Briefing Meeting wilh Hazard Input Oocul:lcnt 1 Ii I l 14 Sj 6 I >-17 :* J: 1 *: I e 2014 2015 1 t, ...,, ,, , ,,. , 9110 I May 16, 2014 Kevin Coppersmith Chair, DCPP SSC PPRP

Subject:

Response to Participatory Peer Review Panel (PPRP) comments on DCPP SSC Workshop #3, Dated April l, 2014

Reference:

Participatory Peer Review Panel Report on Workshop #3, Diablo Canyon Seismic Source Characterization Workshop #3 from Dr. Kevin Coppersmith (Chair), Dr. Steve Day, Dr. Neil Driscoll, and Dr. Tom Rockwell

Dear Dr. Coppersmith:

Thank you for your comments and recommendations on the Diablo Canyon SSC Workshop No. 3 <lated April I, 2014. Our responses to the comments and recommendations arc given below. The PPRP comment is provided in its entirety in italics, followed by the TI Team response. In addition, please find attached an updated schedule through completion of the project. Thank you for your comments, and please do not hesitate to contact me at ( 415) 973-5291 if you would like to discuss the responses. Sincerely William Lettis SSC TI Lead Response to Comments Our responses to the PPRP's comments and recommendations are provided below. We have attempted to respond to all of the PPRP comments; the explicit PPRP comment is shown first in italics, followed by our response. Please do not hesitate to contact us if further clarification is required, or if we have inadvertently overlooked a comment requiring a response. General Observations We would like to thank and congratulate the SSC Tl T earn for a successful workshop. It was clear that much work was done prior to and during the workshop to cover the entire SSC model, its detailed implementation, and its technical justification. We also congratulate the PG&E team for making all of the logistical arrangements to ensure a smoothly run workshop. Thank you. We agree that Workshop #3 was successful and provided important feedback information for the Integration and Model Development phase of the SSH AC process. Specific Comments and Recommendations I. SSHAC Level 3 Process The goal of Workshop #3 within a SSHAC Level 3 process, as described in NUREG-2117, is to provide the Tl Team with feedback in two forms: 1) hazard sensitivity analyses that provide insights into the most significant parts of the preliminary SSC model, and 2) feedback from the PPRP regarding the technical support for the model and the degree to which the model captures the CBR of the TD/. Further, NUREG-2117 prescribes the specific roles that various participants should assume during the course of WS3. For example, all members of the Tl Team are expected to participate in the presentation, discussion, and technical justification for the preliminary SSC model. We were pleased to see that this was certainly the case and this led to provoking discussions and insights into details of the SSC model components, as perceived by various Team members. At WS3 the PPRP is free to question members of the Tl Team regarding details of the SSC model and the technical justification for model elements and the treatment of uncertainties. In this regard, the Tl Team encouraged active PPRP participation and was responsive to the questions posed by the Panel. For example, the Team responded to the Panel's request for changes to the workshop agenda, which allowed additional time to discuss the approach to recurrence modeling. Also, in many cases, the Team positively considered the comments posed by the Panel and will use that information during the finalization of the SSC model. Other aspects of the SSHAC Level 3 process were appropriately conducted. Training in the proper roles of the workshop participants was performed daily, and those roles were enforced. For example, the role of observers was identified throughout the workshop and adequate time was provided for observers to comment on the proceedings daily. An additional bonus, for which the PG&E team should be congratulated, was the organization of a special session at the end of each day to allow the general public to ask questions related to the scientific issues surrounding earthquake hazard analysis. Typically, WS3 within a SSHAC Level 3 project occurs after the completion of the evaluation phase of the work such that proponent and resource experts are not present. An unusual aspect of this project is that data collection activities associated with AB 1632 are ongoing and the PSHA project must consider the results of those activities. Accordingly, PEs and REs were present and participated in the workshop to report their findings. However, the Tl Team was careful to define their role in the workshop and to make it clear how the Team would be considering the results of those studies in the future. The preliminary SSC model was not complete at the time that hazard calculations and sensitivity analyses were conducted for the workshop. However, the PPRP concludes that a sufficient framework, and components of the model had been completed to provide a significant amount of useful feedback to the Team to assist them with the completion of the integration phase of the work. In order for the work to be completed according to the schedule, it is recognized that a significant amount of work will need to done-in a properly prioritized manner-to arrive at a final SSC model. Prior to that time, the Panel would like to continue to review the development of the model prior to the review of the draft PSHA report. Suggestions for the elements of that review are described below under "SSC products for PPRP review." Also, the impact on the schedule will be important and we discuss this below in "Need for PSHA Schedule." We agree that new information has and will become available to the TI Team for evaluation and integration, as appropriate, into the Final SSC Model. We will continue to keep the PPRP appraised of our evaluation and integration of the new data and development of the SSC model. As per the attached schedule, we will convene a Final Briefing to review the model with the PPRP prior to submittal of the draft SSC report. In addition, the TI Team will convene several Working Meetings to finalize development of the Preliminary SSC model, in particular development of the recurrence parameters (effective Poisson rate). We will invite the PPRP to attend these Working Meetings, either in person or via teleconference call or webinar, and to provide feedback to the TI Team. 2. Need for PSHA Schedule Given that the preliminary SSC model is not yet complete, due primarily to the need to finish the ongoing data collection program, we anticipate the need to carefully schedule and prioritize the effort to first complete the preliminary SSC model, obtain additional SSC products and hazard sensitivity results (see below), finalize the SSC model, and document the PSHA report. Specifically, the elements of the schedule that we would like to see on the calendar are the following: *Completion of the preliminary SSC model *Delivery of the preliminary SSC model Hazard Input Document (HID) to the PPRP

• Finalization of the SSC model *Briefing with the PPRP to review the final SSC model
• Delivery of the Draft PSHA report to the PPRP for review
• Review of the Draft PSHA report by the PPRP (minimum six weeks required)
• Delivery of PPRP comments to the Tl T earn *Delivery of Draft Final PSHA report to PPRP for final review *Delivery of PPRP Closure Letter to PG&E We have incorporated these clements of the schedule into the updated Project Schedule, as attached. 3. SSC Products for PPRP Review In order for the Panel to have a full understanding of the SSC model, we would like to request the following products be provided. We understand that all of these products are already part of the planning and deliverables anticipated by the project, but we would like to emphasize their importance to the Panel by listing them below:
• Recurrence curves for rupture sources, particularly for the Hosgri fault *Implementation of the WAACY model for linked ruptures (Mmax ruptures); how do you arrive at b-taif and tail offset? _____________________________ _ *Approach to the use of non-Poisson recurrence models, the logic tree distribution of equivalent Poisson rates, and their impact on hazard and uncertainty contribution
• Impact of logic tree branches for Mchar and Mmax on hazard
• Impact of categorization of rupture sources as either Mmax and Mchar *Discussion of what is aleatory and what is epistemic (e.g., Mmax logic tree, versus aleatory rupture sources) *Hazard sensitivity for all of the above, including running the Shoreline Fault Report model with the new Hosgri rates The documentation will provide the TI Team* s assessment of the above source characteristics, including sensitivity feedback on each of these issues. The TI Team appreciates the feedback from the PPRP at the Workshop on each of these topics, and wil1 address each of these topics at the Final Briefing as well as in the project documentation. 4. Tl Team Action Items The Tl team did an excellent job discussing/summarizing each day's results as well as developing a list of action items required to finalize the SSC model. The PPRP endorses such an approach. Here, we review the Tl team's action items according to an overarching theme, not priority. The PPRP is NOT directing the Tl team with regard to which action item or scope of work needs to be completed; such decisions are the responsibility of the Tl team as they finalize the SSC model. It should be noted that some of the actions identified by the Tl Team relate to immediate actions that are needed to finalize the SSC model, other actions relate to documentation that will be provided in the PSHA report. We include both types of actions in our comments below. a. Documentation of Piercing Points. Documentation of piercing points for offshore fault systems and age models is required. Specifically, the Tl team should explain how the piercing points are used to constrain slip distribution along the fault with the full range of interpretations reported. When multiple piercing points yield different offsets and imply different rates, the Tl team should document how the geologic slip rate distribution is characterized along the fault. We agree. The documentation will include a discussion of how the distribution of slip rate is characterized along each fault, and how various piercing points arc used to constrain fault slip rate, including assessments of data quality, distance along the fault from the DCPP site, age of piercing point, etc. b. Document Use of ONSIP Results. After the SSC model has been finalized, the Tl Team should document how or if new ONshore Seismic Investigation Project (ONSIP) results are used to constrain fault geometry and locations in the Irish Hills. For example, will the dip of the Los Osos and San Luis Bay faults in the OV, SW, and NE tectonic models be constrained by the ONSIP data? Results from the ONSIP study will be evaluated and integrated, as appropriate, into the SSC model. We anticipate that the ONIP data will provide important constraints on the down-dip geometry of some (but not all) faults in the OV, SW and NE tectonic models. The documentation will provide the Tl Team's assessment of the ONSIP data and how the data are used to constrain fault geometry in the three alternative tectonic models. c. Document Definitions of Styles of Faulting. The three proposed tectonic models (OV, SW, NE) entail a rather large range of rakes on some of the individual faults (e.g., the San Luis Bay and Los Osos faults). The style-of-faulting (SOF) categorization of a fault for purposes of applying GMPEs depends upon its rake. We recommend that the SSC Tl team coordinate with the GMC (SWUS) team to ensure that appropriate GMPE SOF classes are assigned to the faults, recognizing the SOF assignment for a given fault may vary depending upon which tectonic model it is participating in. We agree. The Tl Team will coordinate with the GMC (SWUS) Tl Team to ensure that the Final SSC model and HID describe the appropriate rakes for use for each fault in applying the GMPEs. We are aware that the style-of-faulting and rake may vary, both along strike in a particular tectonic model, as well as between models. d. Carefully document/compare with UCERF3. The PPRP agrees with the Tl team's action item to compare the slip rate models, linked rupture models and rupture participation rates to the corresponding UCERF3 results. The SSC model is based on a more current data set for the local faults than is the UCERF3 model, so agreement is not necessarily to be expected. Rather, the objective should be to document the comparison, pointing out any important differences and explaining why they arise. The documentation will include a comparison of the SSC model to the UCERF3 model results, including rupture participation rates for those fault "sections" closest to DCPP. We agree with the PPRP that agreement is not necessarily expected, but our documentation will include an assessment of any differences and an explanation of why they arise. e. Documentation of Slip Allocation and Budget. It is critical that there be complete documentation on how slip is allocated among the various rupture sources and various models to construct the final slip budget. The allocation of slip budget to various earthquakes in the final model will drive the ultimate shape/form of the MFDs, which are the basic input to the hazard model. The documentation wi11 include the Tl Team's assessment of how slip rate is allocated among the various rupture sources within each tectonic model, and how the slip budget for the combined rupture sources adds up to equal each fault slip rate. The TI Team recognizes the impo11ance of this assessment for allocating slip budget to various earthquakes, and significance to the hazard model. f. Explain Differences in Hazard with that of the Shoreline Fault Report. It was clear during multiple/various presentations that the current assessment of hazard is consistently lower than that presented in the Shoreline Report, possibly based on updated information on fault slip rates. This is a significant feedback issue and will need to be understood prior to finalization of the SSC model, and will ultimately need to be completely documented. The documentation will include a comparison of the SSC model hazard results to the Shoreline Fault report hazard results, pointing out any important differences and the TI Team* s assessment of why they arise. The comparison also will be made using the updated SWUS GMPE model for the DCPP site. g. Age Model in the Offshore. The PPRP was pleased to see a coherent age model presented by various PEs and members of the Tl team for use in the assessment of slip rates for the offshore faults illuminated by the LESS studies. This represents an improvement over earlier presentations and indicates a maturation of the offshore age model that is now being applied in the assessment of slip rates. The PPRP has increased confidence that the final slip rates that will be assessed and completely documented by the Tl team in the final report will rely on a mature, defendable age model. The documentation will include the TI Team's assessment of the offshore LESS study for use in constraining the distribution of slip rate along offshore faults. Results from the LESS study will be finalized in June, 2014, and will be evaluated and integrated, as appropriate, into the Final SSC model. We agree that preliminary results from the LESS study have described what appears to be a coherent, well documented age model using sequence-stratigraphy correlation dating methods. The TI Team recognizes the importance of carefully evaluating the LESS study results for assessing and constraining both fault location and distribution of fault slip rate. h. Documentation of Hazard Sensitivity to Fault Models. The three primary fault models could represent different hazard levels at DCPP. It will be important to document the hazard sensitivity of these various models to establish whether one model represents a substantially higher hazard than others, and to be sure that all assumptions are well-founded and applicable uncertainties incorporated. The documentation wi11 include hazard sensitivity analyses comparing each alternative tectonic model, and elements within each model. The assumptions and technical bases for each model will be described in the SSC report. The epistemic weighting given to each model, and elements within each model, however, will be based solely on the technical assessments and not on the level of hazard that each model represents.

January 9, 2015 Mr. Kent S. Ferre Project Manager Pacific Gas & Electric Company 245 Market St. San Francisco, CA 94177

SUBJECT:

Participatory Peer Review Panel Letter No. 2: DCPP SSC SSHAC Project Draft Report Installment #2

Dear Mr. Ferre,

This letter provides in writing the comments of the Participatory Peer Review Panel (PPRP) on the Diablo Canyon Seismic Source Characterization (SSC) SSHAC Project Draft Report. We (Coppersmith, Day, Rockwell, and Driscoll), the designated PPRP, want to express our appreciation for the opportunity to review Installment #2 of the Draft Report, which consists of Chapters 6, 7, 11, and 12, as well as the EPR Appendix. Our review comments are provided in the attached table and each comment is associated with a unique number that continues consecutively from our comments on Installment #1. The table includes a column for the Tl Team to summarize the revisions made to the report to respond to each comment. We would request that a completed copy of the table be returned to us with the revised report to expedite our follow-up review. We look forward to answering any questions of clarification regarding these comments during our conference call on Wednesday, January 14, 2015. Sincerely, DCPP SSC PPRP K. Coppersmith, Chair S. Day N. Driscoll T. Rockwell January 21, 2015 Mr. Kent S. Ferre Project Manager Pacific Gas & Electric Company 245 Market St. San Francisco, CA 94177

SUBJECT:

Participatory Peer Review Panel Letter No. 3: DCPP SSC SSHAC Project Draft Report Installment #3

Dear Mr. Ferre,

This letter provides in writing the comments of the Participatory Peer Review Panel (PPRP) on the Diablo Canyon Seismic Source Characterization (SSC) SSHAC Project Draft Report. We (Coppersmith, Day, Rockwell, and Driscoll), the designated PPRP, want to express our appreciation for the opportunity to review Installment #3 of the Draft Report, which consists of Chapters 9 and 10, as well as the WAACY Appendix. Our review comments are provided in the attached table and each comment is associated with a unique number that continues consecutively from our comments on Installment #2. The table includes a column for the Tl Team to summarize the revisions made to the report to respond to each comment. We would request that a completed copy of the table be returned to us with the revised report to expedite our follow-up review. We look forward to answering any questions of clarification regarding these comments during our conference call on Friday, January 23, 2015. Sincerely, DCPP SSC PPRP K. Coppersmith, Chair S. Day N. Driscoll T. Rockwell February 12, 2015 Mr. Kent S. Ferre Project Manager Pacific Gas & Electric Company 245 Market St. San Francisco, CA 94177

SUBJECT:

Participatory Peer Review Panel Letter No. 3: DCPP SSC SSHAC Project Draft Report Installment #4

Dear Mr. Ferre,

This letter provides in writing the comments of the Participatory Peer Review Panel (PPRP) on the Diablo Canyon Seismic Source Characterization (SSC) SSHAC Project Draft Report. We (Coppersmith, Day, Rockwell, and Driscoll), the designated PPRP, want to express our appreciation for the opportunity to review Installment #3 of the Draft Report, which consists of Chapter 13, Appendices H, S, and Y, and the Earthquake Catalog Appendix. Our review comments are provided in the attached table and each comment is associated with a unique number that continues consecutively from our comments on Installment #3. The table includes a column for the Tl Team to summarize the revisions made to the report to respond to each comment. We would request that a completed copy of the table be returned to us with the revised report to expedite our follow-up review. We look forward to answering any questions of clarification regarding these comments during our conference call on Tuesday, February 17, 2015. Sincerely, DCPP SSC PPRP K. Coppersmith, Chair S. Day N. Driscoll T. Rockwell February 20, 2015 Mr. Kent S. Ferre Project Manager Pacific Gas & Electric Company 245 Market St. San Francisco, CA 94177

SUBJECT:

Participatory Peer Review Panel Comments DCPP SSC SSHAC Project Draft Report Installment #5

Dear Mr. Ferre,

This letter provides in writing the comments of the Participatory Peer Review Panel (PPRP) on the Diablo Canyon Seismic Source Characterization (SSC) SSHAC Project Draft Report. We (Coppersmith, Day, Rockwell, and Driscoll), the designated PPRP, want to express our appreciation for the opportunity to review Installment #5 of the Draft Report, which consists of Chapter 14. Our review comments are provided in the attached table and each comment is associated with a unique number that continues consecutively from our comments on Installment #4. The table includes a column for the Tl Team to summarize the revisions made to the report to respond to each comment. We would request that a completed copy of the table be returned to us with the revised report to expedite our follow-up review. Please feel free to contact Kevin with any questions of clarification regarding these comments. Sincerely, DCPP SSC PPRP K. Coppersmith, Chair S. Day N. Driscoll T. Rockwell ( >/] P<N:iii;: .-w,J I' * * :i --March 11, 2015 PG&E Letter DCL-15-035 Barry S. Allen Vice President. Nuclear Services Oiablo Canyon Power Plan I Mail Code 104/6 P. 0. 56 Avila Beach. CA 93424 805. 545, 4668 Internal: 691.4688 Fal: 805. 545. 6445 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk 11555 Rockville Pike 10 CFR 50.54(f) Rockville, MD 20852 Docket No. 50-275, OL-DPR-80 Docket No. 50-323, OL-DPR-82 Diablo Canyon Units 1and2 Response to NRC Request for Information Pursuant to 1 O CFR 50.54(f) Regarding the Seismic Aspects of Recommendation 2.1 of the Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accident: Seismic Hazard and Screening Report

References:

1. NRC Letter, "Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Recommendations 2.1, 2.3, and 9.3 of the Near-Term Task Force Review of Insights from the Fukushima Dai-lchi Accident," dated March 12, 2012 2. Electric Power Research Institute (EPRI) Report No. 1025287, "Seismic Evaluation Guidance: Screening, Prioritization and Implementation Details (SPID) for the Resolution of Fukushima Near-Term Task Force Recommendation 2.1: Seismic," dated November 2012 3. PG&E Letter DCL-13-044, "Response to NRC Request for Information Pursuant to 1 O CFR 50.54(F) Regarding the Seismic Aspects of Recommendation 2.1 of the Near-Term Task Force Review of Insights from the Fukuhsima Dai-ichi Accident," dated April 29, 2013 4. NRC Letter, "Supplemental Information Related to Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Seismic Hazards Reevaluations for Recommendation 2.1 of the Near-Term Task Force Review of Insights from the Fukushima Dai-lchi Accident," dated February 20, 2014 A member of tlie STARS (Strategic Teaming and Resource Sharing) Alliance Callaway

• Diablo Canyon
• Palo Verde
• Wolf Creek I° -{'-Document Control Desi< !Jfi March 11, 2015 Page2

Dear Commissioners and Staff:

PG&E Letter DCL-15-035 On March 12, 2012, the Nuclear Regulatory Commission (NRC) issued Reference 1 to Pacific Gas and Electric Company (PG&E) directing PG&E to reevaluate the seismic hazards at Diablo Canyon Power Plant (DCPP) using present-day NRC requirements and guidance and to identify actions to address plant specific vulnerabilities associated with the updated seismic hazards. Specific requirements are outlined in Reference 1, Enclosure 1 . In response to Reference 1, and following the guidance provided in Reference 2, PG&E performed a seismic hazard reevaluation for DCPP and developed a specific ground motion response spectrum (GMRS) for screening purposes. Enclosure 1 to this letter provides PG&E's Seismic Hazard and Screening Report. Consistent with Reference 41 the enclosed seismic hazard reevaluations are distinct from the current design and licensing bases of DCPP. Consequently, the results of these analyses -performed using present-day regulatory guidance, methodologies, and information -would not generally be expected to call into question the operability or functionality of structures, systems and components, and were not reportable pursuant to 1 O CFR 50. 72, "Immediate Notification Requirements for Operating Nuclear Power Reactors," and 10 CFR 50.73, "Licensee Event Report System." The GMRS was developed through the performance of a Senior Seismic Hazards Analysis Committee (SSHAC) Level 3 seismic source characterization study and a SSHAC Level 3 ground motion characterization study, in accordance with NUREG 2117, "Practical Implementation Guidelines for SSHAC Level 3 and 4 Hazard Studies," dated April 2012, followed by a site-specific amplification study. A copy of the participatory peer review panels (PPRP) closure letters for seismic source characterization and the ground motion characterization (GMC) is provided in Enclosure 1, Appendix C. The GMC closure letter found that the DCPP SSHAC meets the expectations for a SSHAC Level 3 study but requested that additional technical justification be provided regarding the application of the directivity component of the GMC model to the DCPP site. The SSHAC Technical Integration team provided a response to the PPRP request (see Enclosure 1, Appendix C). PG&E will submit the resolution of the PPRP identified request as soon as it is completed. As discussed in* NRC Letter, "Diablo Canyon Power Plant, Unit Nos. 1 and 2 -NRC Review of Shoreline Fault (TAC Nos. ME5306 and ME5307)," dated October 12, 2012, PG&E's reevaluation used the DCPP double design earthquake (ODE) as the safe shutdown earthquake for screening purposes. PG&E's screening evaluation of the GMRS indicates that the GMRS exceeds the DDE in the 1 to 10 hertz frequency range. Therefore, DCPP screens-in for a seismic risk evaluation A member of the STARS (Strategic Teaming and Resource Sharing) Alliance Callaway

• Diablo Canyon
• Palo Verde
• Wolf Creek j Document Control Desk March 11, 2015 Page 3 PG&E Letter DCL-15-035 in accordance with Reference 2. PG&E will perform the seismic risk evaluation as required in Reference 2. In the interim, PG&E compared the GMRS to the design and licensing basis 1977 Hosgri earthquake spectrum and to the results of the long term seismic program seismic margins assessment. These comparisons demonstrate that there is reasonable assurance that the DCPP structures, systems, and components required for safe shutdown will continue to perform their intended safety function if subjected to the ground motions at the newly developed GMRS levels. PG&E will perform an update of the seismic probabilistic risk assessment (PRA), which will include high-frequency confirmation, and a spent fuel pool integrity evaluation in accordance with Reference 2. PG&E is making a new regulatory commitment (as defined by NEI 99-04). PG&E is revising an existing regulatory commitment as shown in Enclosure 2. PG&E has determined that it is not necessary to perform an expedited seismic evaluation process as PG&E's interim evaluation provides reasonable assurance that it is safe to operate DCPP while the updated/upgraded seismic PRA is developed. Refer to Enclosure 2. If you have any questions, or require additional information, please contact Mr. L. Jearl Strickland at (805) 781-9795. I declare under penalty of perjury that the foregoing is true and correct. Executed on March 11, 2015. Sincerely, 5'". Barry S. Allen Vice President, Nuclear SetVices dmfn/50465913-3 Enclosures cc: Diablo Distribution cc:/enc: Marc L. Dapas, NRC Region IV Administrator Dan H. Dorman, NRC/NRR Director Thomas R. Hipschman, NRC, Senior Resident Inspector Siva P. Lingam, NRR Project Manager A member of the STARS (Strategic Teaming and Resource Sh11ring) Alliance Callaway
• Diablo Canyon
• Palo Verde
• Wolf Creel1 PG&E Letter DCL-15-035 Pacific Gas and Electric Company Seismic Hazard Screening Report Diablo Canyon Power Plant Units 1 and 2 PG&E Letter DCL-15-035 Page 1 of 60 Pacific Gas and Electric Company Seismic Hazard and Screening Report Diablo Canyon Power Plant Units 1 and 2 Table of Contents Enclosure 1 PG&E Letter DCL-15-035 Page 2of60 1.0 Introduction ................................................................................................................ 4 2.0 Seismic Hazard Reevaluation .................................................................................... 8 2.1 Regional and Local Geology ........................................................................... 9 2.1.1 Bedrock Stratigraphy ............................................................................ 9 2.1.2 Tectonic Setting .................................................................................. 10 2.1.3 Significant Faults ................................................................................ 10 2.1.4 Site Geology ....................................................................................... 12 2.2 Probabilistic Seismic Hazard Analysis ........................................................... 15 2.2.1 Probabilistic Seismic Hazard Analysis Results ................................... 15 2.2.2 Base Rock Seismic Hazard Curves .................................................... 17 2. 3 Site Response Evaluation ............................................................................. 20 2.3.1 Description of Subsurface Material ..................................................... 21 2.3.2 Development of Base Case Profiles and Nonlinear Material Properties ........................................................................................... 25 2.3.3 Randomization of Base Case Profiles ................................................ 28 2.3.4 Input Spectra ...................................................................................... 28 2.3.5 Methodology ....................................................................................... 28 2.3.6 Amplification Functions ....................................................................... 29 2.3.7 Control Point Seismic Hazard Curves ................................................. 32 2.4 Control Point Response Spectra ................................................................... 33 3.0 Plant Design, Licensing, and LTSP Evaluation Bases Ground Motions ................... 36 3.1 Description of Response Spectra Shapes ..................................................... 38 3.1.1 Double Design Earthquake Response Spectrum ............................... 38 3.1.2 1977 Hosgri Earthquake Response Spectrum .................................... 40 3.1.3 Long Term Seismic Program Earthquake Spectrum ........................... 42 3.2 Control Point Elevation .................................................................................. 44 4.0 Screening Evaluation ............................................................................................... 46 4.1 Risk Evaluation Screening (1to10 Hz) ......................................................... 46 4.2 High Frequency Screening(> 10 Hz) ............................................................ 46 4.3 Spent Fuel Pool Evaluation Screening (1to10 Hz) ..................................... 47 5.0 Interim Evaluation .................................................................................................... 48 5.1 Expedited Seismic Evaluation Process ......................................................... 51 PG&E Letter OCL-15-035 Page 3of60 5.2 Walkdowns to Address NRC Fukushima NTTF Recommendation 2.3: Seismic .......................................................................................................... 51 6. O Conclusions ............................................................................................................ 53 7.0 References ............................................................................................................... 54 7. 1 Electric Power Research Institute .................................................................. 54 7.2 Pacific Gas and Electric Company ................................................................ 54 7.3 United States Nuclear Regulatory Commission ............................................. 55 7.4 Nuclear Energy Institute ............................................................................... 58 7.5 Other ............................................................................................................. 58 List of Appendices No. of Pages Appendix A-Additional Seismic Hazard Curve Data ......................................................... 13 Appendix B-Long Term Seismic Program Seismic Margin Spectrum ................................ 9 Appendix C-PPRP Endorsements ................................................................................... 18 1.0 Introduction Enclosure 1 PG&E Letter DCL-15-035 Page 4of60 Following the accident at the Fukushima Daiichi nuclear power plant resulting from the March 11, 2011, Great Tohoku Earthquake and subsequent tsunami. the Nuclear Regulatory Commission (NRC) established a Near Term Task Force (NTTF) to conduct a systematic review of NRC processes and regulations and to determine if the agency should make additional improvements to its regulatory system. The NTTF developed a set of recommendations intended to clarify and strengthen the regulatory framework for protection against natural phenomena. Subsequently, on March 12, 2014, the NRC issued a request for information letter under Title 10, "Energy," of the Code of Federal Regulations, Part 50, "Domestic Licensing of Production and Utilization Facilities," Section 50.54, "Conditions of Licenses, Subsection (f), "Request for Information," (March 12, 2012 10 CFR 50.54{f) letter). to assure that these recommendations are addressed by all United States nuclear power plants (NRC 2012). The March 12, 2012 10 CFR 50.54(f) letter requests that licensees and holders of construction permits under 10 CFR 50 reevaluate the seismic hazards at their sites against present-day NRC requirements. Depending on the comparison between the reevaluated seismic hazard and the current design/licensing basis, the result is either no further risk evaluation or the performance of a seismic risk assessment. Risk assessment approaches acceptable to the NRC staff include a seismic probabilistic risk assessment (SPRA), or a seismic margin assessment (SMA). Based upon the risk assessment results, the NRC staff will determine whether additional regulatory actions are necessary. This report provides the information requested in items (1) through (7) of the "Requested Information" section and Attachment 1 of the 10 CFR 50.54(f) letter pertaining to NTTF Recommendation 2.1 (NRC 2012) for Diablo Canyon Power Plant (DCPP), located in San Luis Obispo County, California. In providing this information, Pacific Gas and Electric Company (PG&E) followed the guidance provided in Electric Power Research Institute (EPRI) Technical Report No. 1025287, "Seismic Evaluation Guidance: Screening, Prioritization, and Implementation Details (SPID) for the Resolution of Fukushima Near-Term Task Force Recommendation 2.1: Seismic" (EPRI 2013a). The original geologic and seismic siting investigations for DCPP predate the issuance of Appendix A, "Seismic and Geologic Siting Criteria for Nuclear Power Plants," to 10 CFR 100, "Reactor Site Criteria" (NRC 1973). The double design earthquake (ODE), which the NRC directed PG&E to use for the response to the March 12, 2012 10 CFR 50.54(f) letter1, was originally developed using specific criteria and methods, and is used for the design of Design Class I structures, systems, and components, where Design Class I is DCPP's As stated in the NRC's letter to PG&E dated October 12, 2012 (NRC 2012c), "for the purposes of the response to the March 12, 2012 request for information. the NRC statt expects PG&E to use the DDE for comparison with the reevaluated seismic hazard GMRS."

2 Enclosure 1 PG&E Letter DCL-15-035 Page 5of60 equivalent to Seismic Category I, as defined in NRC Regulator Guide 1.29, "Seismic Design Classification" (NRC 1978). In addition, the seismic design of OCPP includes the 1977 Hosgri earthquake (HE). The 1977 HE, which has significantly larger ground motions than the ODE, is also used for design and evaluation of Design Class I structures, systems, and components. Finally, in response to License Condition 2.C.(7) of the DCPP Unit 1 operating license, the Long Term Seismic Program (L TSP) earthquake (L TSPE) was developed. The L TSPE was used for DCPP's prior SPRA and SMA (1988 L TSP Final Report, PG&E 1988). In response to the NRC's March 12, 2012 10 CFR 50.54(f) letter. and following the guidance provided in the screening, prioritization, and implementation details (SPID)2 (EPRI 2013a) and a Senior Seismic Hazard Analysis Committee (SSHAC) process established by the NRC for western United States plants. a seismic hazard reevaluation was performed for OCPP. This included development of DCPP*specific ground motion response spectrum (GMRS). Consistent with the NRC letter dated February 20, 2014, (NRC 2014) the seismic hazard reevaluations presented herein are being performed to beyond current design/licensing basis requirements for OCPP. Therefore, the results do not call into question the operability or functionality of structures, systems, and components and are not reportable pursuant to 10 CFR 50.72, "Immediate Notification Requirements for Operating Nuclear Power Reactors," or 10 CFR 50.73, "Licensee Event Report System." The GMRS was developed through the performance of a SSHAC Level 3 seismic source characterization study and a SSHAC Level 3 ground motion characterization study, in accordance with NUREG-2117, "Practical Implementation Guidelines for SSHAC Level 3 and 4 Hazard Studies," (NRC 2012b). In addition, a site-specific amplification study was performed. A copy of the participatory peer review panels (PPRP) closure letters for seismic source characterization and the ground motion characterization (GMC) is provided in Appendix C. The GMC closure letter found that the DCPP SSHAC meets the expectations for a SSHAC Level 3 study but requested that additional technical justification be provided regarding the application of the directivity component of the GMC model to the DCPP site. The SSHAC technical integration team provided a response to the PPRP request (see Appendix C). PG&E will submit the resolution of the PPRP identified request as soon as it is completed. Note: It has been recognized. and acknowledged by the NRC in public meetings (NRC 2014c and NRC 2014d), that the guidance provided in the SPID is more aligned with the seismic hazard studies associated with central and eastern United States plants, while SSHAC studies, performed in accordance with NUREG-2117 (NRG 2012b), and site-specific amplification studies, utilizing more up-to-dale, modern day methodologies. are appHcable to western United States plants. PG&E Letter DCL-15-035 Page 6 of 60 OCPP's screening evaluation of the GMRS, performed in accordance with SPID Figure 1-1, indicates that the GMRS exceeds the DOE in the 1to10 Hz frequency range. Therefore, DCPP screens-in for a seismic risk evaluation per the requirements of the SPID. PG&E will perform a SPRA in accordance with the EPRI guidance (EPRI 2013a) and the schedule as defined in NEl's letter to the NRC, dated April 9, 2013 (NEI 2013) and confirmed in NRC's letter, dated May 7, 2013 (NRC 2013). In accordance with the NRC's February 20, 2014 request for supplemental information from plant's that screen-in for a seismic risk evaluation (NRC 2014)! PG&E has performed an interim evaluation to address the seismic safety of DCPP. This interim evaluation compared the GMRS to the design/licensing basis 1977 HE spectrum and to the results of the L TSP seismic margin evaluation. This comparison demonstrated that there is reasonable assurance that DCPP's safety related structures. systems, and components will continue to perform their intended safety function if subjected to the ground motions at the newly developed GMRS levels. PG&E's letter to the NRC dated April 29, 2013 (PG&E 2013d), indicated that the expedited seismic evaluation process (ESEP) would be implemented for DCPP in accordance with EPRI Technical Report No. 3002000704, "Seismic Evaluation Guidance: Augmented Approach for the Resolution of Fukushima Near-Term Task Force Recommendation 2.1: Seismic" (EPRI 2013b). However, as noted above, the interim evaluation already demonstrates DCPP's seismic safety while an updated/upgraded SPRA is being developed. No additional insights will be gained for DCPP from the implementation of the ESEP. PG&E concludes that only a SPRA will be performed, rather than the implementation of an ESEP, such that the critical skilled resources can be devoted towards an update/upgrade of the SPRA. The SPRA. which includes the high-frequency confirmation, will be performed in accordance with the EPRI guidance (EPRI 2013a) and the schedule as defined in NEl's letter to the NRC, dated April 9, 2013 (NEI 2013) and confirmed in NRC's letter, dated May 7, 2013 (NRC 2013). PG&E's spent fuel pool (SFP) screening evaluation indicates that the GMRS exceeds the DCPP ODE in the 1 to 10 Hz frequency range. Therefore, DCPP screens-in for further review of the SFPs as required by the SPID. PG&E also performed an interim evaluation to address the seismic safety of the SFPs, which are located in the fuel handling area of the auxiliary building. Comparing the GMRS with the design/licensing basis 1977 HE spectrum and the L TSP seismic margin shows that the auxiliary building has a significant margin beyond the GMRS. Therefore, there is reasonable assurance that DCPP's SFPs will maintain their structural integrity if subjected to the ground motions at the newly developed GMRS levels. As indicated in PG&E's letter dated April 29. 2013 (PG&E 2013d), PG&E will perform additional evaluations of the SFPs in accordance with the EPRI guidance (EPRI 2013a) and the schedule as defined PG&E Letter DCL-15-035 Page 7of60 by the NEl's letter to the NRC, dated April 9, 2013 (NEI 2013) and confirmed in the NRC's letter dated May 7, 2013 (NRC 2013). 2.0 Seismic Hazard Reevaluation Enclosure 1 PG&E Letter DCL-15-035 Page 8 of 60 DCPP is located on the central California coast, approximately 19 kilometers (km) (12 miles (mi.)) west of San Luis Obispo, California (Figure 2.0-1). The plant is on the southwestern margin of the Irish Hills, an area of moderate relief bordered by Morro Bay on the north, San Luis Obispo Bay on the south, and Los Osos Valley on the east. The Irish Hills are the northwestern part of the San Luis Range, which trends approximately west-northwest/east-southeast and separates the Santa Maria River Valley to the south from the Los Osos and Edna valleys to the north . ...... ... .... _ '*'\* Pacific Ocean EXPlANATION .-.---* -Stginirlcanl faults -Other laults I Ouacernary I Tertiary i-Pie* Tertiary. mostly Mesozoic N O 2 4 A :-S mi. ** 111Af'*v*,o1 >bin Sal'*.d l*.):u;,, 0 Figure 2.0-1: Simplified Geology and Faults in DCPP's Vicinity PG&E Letter DCL-15-035 Page 9of60 DCPP's site region is within the broad boundary between the Pacific and North American tectonic plates. The majority of relative motion between the plates is accommodated by the right-lateral strike-slip San Andreas Fault Zone (SAFZ), located approximately 80 km (50 mi.) northeast of DCPP. Lesser rates of boundary deformation are accommodated by faults and folds in the coastal and offshore areas around the site. Historical earthquakes in the DCPP region have been moderate to large. The largest ground motion recorded at the site is a peak ground acceleration (PGA) (horizontal) of 0.042 g from the 2003 moment magnitude (M) 6.5 San Simeon earthquake. This ground motion is significantly lower than the ground motions from the design, licensing, and evaluation basis earthquakes (see Section 3.0 for definitions: a) Design Earthquake (OE}: An earthquake having a horizontal PGA of 0.20g. b) Double Design Earthquake (DOE): The ODE is defined as twice the DE and is an earthquake having a horizontal PGA of 0.40 g. The NRC staff requested that PG&E use the DOE for the GMRS comparison (NRC 2012c). c) 1977 Hosgri Earthquake (HE): DCPP's highest-level design/licensing basis earthquake having a horizontal PGA of 0.75 g. d) 1991 Long Term Seismic Program Earthquake (L TSPE): OCPP's review level earthquake associated with the SPRA and SMA, having a horizontal PGA of 0.83 g. 2.1 Regional and Local Geology Bedrock in OCPP's vicinity includes highly deformed Mesozoic and Cenozoic sedimentary and volcanic rocks. Foundations of principal plant buildings are founded directly on volcaniclastic rocks of the Miocene Obispo Formation (Fm.). 2.1.1 Bedrock Stratigraphy Basement rocks exposed in the central California coastal region generally consist of Jurassic to Cretaceous Franciscan Complex rocks (primarily melange, metavolcanics, ophiolite, and serpentine) faulted against Cretaceous marine arkosic to lithic sandstone (Figure 2.0-1). Overlying basement rocks in OCPP's vicinity are a sequence of Cenozoic sedimentary and volcanic rocks deposited in fault-bounded, marine to coastal sedimentary basins. Faulted and folded strata of the Pismo basin are located beneath the DCPP site and much of the San Luis Range in the Pismo syncline PG&E Letter DCL-15-035 Page 10of60 (Figure 2. 0-1). The base of the Pismo basin Cenozoic sequence consists of the Oligocene Rincon shale and Vaqueros sandstone, which unconformably overlie the Mesozoic basement rocks. Overlying the Oligocene strata are the Miocene Obispo and Monterey Formations and the Miocene to Pliocene Pismo Fm.. The Obispo Fm. consists of resistant zeolitized tuft, tuffaceous marine sandstone, and diabase, whereas the Monterey and Pismo Formations consist of nonvolcanic marine siltstone, chert, and porcelaneous shale. 2.1.2 Tectonic Setting DCPP is located within a tectonic region of distributed transpressional dextral shear bordering the eastern margin of the Pacific Plate. The SAFZ, located approximately 80 km (50 mi.) northeast of DCPP, accommodates most of the relative motion between the Pacific Plate and the Sierra Nevada-Great Valley microplate. West of the SAFZ, an additional component of relative Pacific-Sierra Nevada plate motion is accommodated by slip on various Quaternary faults bounding crustal blocks and, to a lesser extent, by deformation within the blocks. In DCPP's site vicinity, the San Luis Range and adjacent valleys and ranges are underlain by crustal blocks that together make up a larger tectonic element called the Los Osos domain (Lettis et al 2004). The Los Osos domain is a triangular structural region bounded by three Quaternary faults: the northwest-striking lateral oblique Oceanic-West Huasna fault zone on the east: the left-lateral oblique Santa Ynez River fault on the south; and the striking right-lateral Hosgri-San Simeon fault zone on the west (Figure 2.0-1). Individual blocks within the Los Osos domain are bounded by northwest-striking reverse, oblique, and strike-slip fault zones. Crustal shortening within the Los Osos domain is accommodated primarily by reverse faulting along the block margins, producing alternating uplifted and down-dropped blocks (Lettis et al 1994, Lettis et al 2004). Additional crustal shortening and dextral shear is accommodated by a combination of reverse, oblique, and strike-slip faulting between and within blocks and by block rotation. OCPP is located within the San Luis-Pismo block, which is topographically expressed by the San Luis Range. The San Luis-Pismo block is bounded by the Los Osos fault zone on the north, by the faults of the "southwestern boundary zone" (including the San Luis Bay, Wilmar Avenue, Los Berros, and Oceano fault zones) on the south, and by the Hosgri fault zone on the west (Figure 2.0-1). 2.1.3 Significant Faults Faults that contribute significantly to the seismic hazard at DCPP include the Hosgri fault zone, the Los Osos fault zone, the San Luis Bay fault within the southwestern boundary zone, and the Shoreline fault (Figure 2.0-1 ). 2.1.3.1 Hosgri Fault Zone Enclosure 1 PG&E Letter DCL-15-035 Page 11of60 The Hosgri fault zone is the southern part of the larger 410 km (255 mi.) long San Gregorio-San Simeon-Hosgri fault system (Figure 2.0-1 ). The location of the offshore Hosgri fault zone is known primarily from the interpretation of marine seismic-reflection data. The fault zone consists of multiple vertical to steeply dipping traces in a zone up to 2.5 km (1.6 mi.) wide directly offshore of OCPP and forms the western termination of the offshore bedrock platform associated with uplift of the San Luis-Pismo block (PG&E 1988, PG&E 1990, PG&E 2011; Willingham et al 2013). Focal mechanisms and the distribution of seismicity along the Hosgri fault zone document nearly pure strike slip on a near vertical to steeply east-dipping fault to a depth of 12 km (7.5 mi.) (Mclaren and Savage 2001; Hardebeck 2010, Hardebeck 2013). Slip rate studies provide an estimate of approximately 1 to 3 millimeters per year (mm/year) of right-lateral slip on the Hosgri fault near OCPP (Hanson and Lettis 1994; Johnson et al 2014; PG&E 2014, Chapter 3). These rates are consistent with regional geodetic data showing approximately 1 to 3 mm/year of plate-margin lateral shear in the region west of the West Huasna fault (OeMets et al 2014). 2.1.3.2 Los Osos Fault Zone The Los Osos fault zone borders the northeastern margin of the San Luis Range (Figure 2.0-1). The south to southwest-dipping fault generally separates the uplifting San Luis-Pismo block from the subsiding or southwest-tilting Cambria block to the northeast (lettis et al 1994). As described by Lettis and Hall (Lettis and Hall 1994), the fault zone is a 2 km (1.2 mi.) wide system of discontinuous, sub-parallel and en-echelon fault traces extending from an intersection with the Hosgri fault zone in Estero Bay on the north to an intersection with the West Huasna fault southeast of San Luis Obispo, for a distance of over 55 km (34 mi.). The slip rate of this reverse to reverse-oblique fault is estimated to be approximately 0.2 to 0.4 mm/year (PG&E 2015). 2.1.3.3 San Luis Bay Fault within the Southwestern Boundary Zone The southwestern margin of the San Luis Range is bordered by a complex zone of late Quaternary reverse, oblique-slip and possibly strike-slip faults (Figure 2.0-1). These faults in aggregate separate the San Luis-Pismo block from the subsiding Santa Maria Valley block to the southwest (Lettis et al 1994). The zone of faults is collectively called the southwestern boundary zone, and is 4 to 10 km (2.5 to 6.2 mi.) wide and over 60 km (30 km) long (Lettis et al 1994; Lett1s et al 2004). The faults generally strike west-northwest and dip moderately to steeply to the northeast. Principal structures within this fault zone include the San Luis Bay, Wilmar Avenue, Los Berros, Oceano, and Nipomo faults. The cumulative rate of vertical separation across the fault zone, based primarily on PG&E Letter Page 12 of 60 deformation of the marine terrace sequence along the coast and southwest side of the range onshore, ranges from about 0.1 to 0.3 mm/year with each fault generally having a rate of 0.04 to 0.1 mm/year (Lettis et al 1994). Within the southwestern boundary zone, the north-dipping, reverse-slip San Luis Bay fault lies closest to DCPP. The fault has an estimated slip rate of approximately 0.1 to 0.3 mm/year (PG&E 2015). 2.1.3.4 Shoreline Fault Zone The Shoreline fault was originally identified from a seismicity lineament trending approximately N60°W to N70°W offshore and parallel to the coast in the vicinity of DCPP (Hardebeck 2010) (Figure 2.0-1 ). Mapping of the Shoreline fault zone at and near the seafloor was performed by PG&E (PG&E 2011; PG&E 2014, Chapters 2 and 3). The hypocentral distribution of seismicity forms a nearly vertical alignment that extends to a depth of about 8 to 10 km, and focal mechanisms indicate the fault is right-lateral strike slip (Hardebeck 2013). Hardebeck (Hardebeck 2013) interprets that to the north the Shoreline fault zone likely connects with the Hosgri fault zone, a result that is consistent with PG&E (PG&E 2014, Chapter 2). Within San Luis Obispo Bay and south of the seismicity lineament, high-resolution 30 seismic data show that the Shoreline fault zone displaces sediments of late Quaternary age providing clear geologic evidence of late Quaternary fault activity (PG&E 2014, Chapter 3). The Shoreline fault zone has an estimated slip rate of approximately 0.03 to 0.15 mm/yr (PG&E 2015). 2.1.4 Site Geology The geology of DCPP's site area consists of Tertiary Obispo Fm. resistant tuff, volcaniclastic strata, and later-stage Obispo Fm. diabase that intruded into the Obispo Fm. volcaniclastics, Quaternary surficial deposits, and engineered fill (Figures 2.1.4-1 and 2.1.4-2). Older Cretaceous sandstone and Franciscan basement rocks are mapped on the seafloor approximately 500 meters (m) southwest of DCPP (Figure 2.1.4-1 ), and onshore along the coastline several km to the southeast (Figure 2.0-1; PG&E 2014, Chapter 9). Four map-scale Obispo Fm. sub-units, or lithofacies, are recognized within the DCPP site area. From oldest to youngest, these sub-units are as follows: a) Resistant, bedded to massive tuffaceous rocks. including possible "peperite," a near-source intrusive tuff (Tmor) b) Bedded, shaley siltstone with tuffaceous fine sandstone interbeds (Tmofc) c) Bedded, tuffaceous and dolomitized fine sandstone and siltstone (Tmofb) d) Massive to jointed diabase (Tmod). PG&E Letter DCL-15-035 Page 13 of 60 The diabase sub-unit intrudes all the other lithologies, and thus is the youngest (PG&E 2014, Chapter 9). Figure 2.1.4-1: Geologic Map of DCPP's Site Area from (PG&E 2014, Chapter 9) (Explanation of geologic units and symbols are shown on Figure 2.1.4-2) af 2" Qsw .,, c: ,_ ., Qts ;;;J 0 Qm Ou Ks KJf Geologic Units Artificial fill: fill ma1erial emplaced locally during construction and improvement activities. Shallow fills not shown: bedrock with trenches and excavation for power block shown; filled with al. Sand wave deposits, offshore: unlilhifled sheets of sand that form migrating marine dunes. Landslide deposits: unllthified masses of displaced bedrock and/or soil: may be active or inactive. Marine terrace deposits: unlithified to weakly lithified marine sand and gravel deposited above wave*cut platforms in the Pleistocene and commonly overlain by alluvial fan and cotluvial deposits. Quaternary deposits, undifferentiated: unlitflified silt, sand. and/or gravel; consists of alluvial fan, fluvial terrace. alluvial and colluvial deposits. Tmod Tmofb Tmok -rmor Obispo Formation, diabase: brown, aphanilic to phanetitic. intrus:ve in dikes and sills. Obispo Formation, fine.grained sub-member b: Bedded tuffaceous, dolomitic, fine to medium-bedded siltstone and fine sandstone. Obispo Formation, fine-grained sub-member c: Bedded shale and siltstone. very fine bedded silly shale with medium bedded. dolomitic siltstone intcrbeds. Obispo Formation. resistant member: Bedded to massive zeolitic tuft. tuft breccia, and tuffac:eous sandstone. Cretaceous Sandstone: arkosic to lithic sandstone, brown. bedded, well-lithified, fine-to course-grained. includes minor shale. Franciscan Complex, undifferentiated 0.. ::! (!) -0 c ., m .!i c. c. .,, E ., ::l .Q > c. E e 11. Enclosure 1 PG&E Letter DCL-15-035 Page 14 of 60 Geologic Structures ., Contact: solid where well located. long dash where approximate, short dash where inferred. dotted where concealed, queried where uncertain. -.. H__!vl .* -* * -* * -*

• Boundary (contact) between Obispo diabase and tuffaceous rocks interpreted from helicopter magnetic survey (PG&E. 2C11 ). Line may not follow exact contact of reek at surface. --t----.. --t-----------***';I*** A A. Syncline: dashed where approximate, dotted where concealed. An ow poinls in direction of plunge. Anticline: dashed where approximate, dotted where concealed. Arrow points in direction of plunge. fault: solid where well located. ror.g dash wt'lere approximate, short dash where inferred. dotted where concealed. queried where uncertain. Geographical Features Roads Buildings Coastline (white line) at mean lower low waler (approximate sea level) Vp Cross sections (Figure 2.3.1-3) Figure 2.1.4-2: Explanation of Geologic Units and Symbols for Figure 2.1.4-1 PG&E Letter DCL-15-035 Page 15of60 DCPP is underlain by gently to steeply dipping sub-unit Tmofb, the bedded, tuffaceous and dolomitized fine sandstone and siltstone (Figure 2. 1. 4-1). Directly adjacent to the foundation area, this volcaniclastic sub-unit is locally unconformably overlain by Quaternary surficial units including alluvial fan sediments (mapped as part of undifferentiated Quaternary deposits (Ou)) and marine terrace deposits (Om) (Figure 2.4.1-1 ). Additionally, engineered fill (af) underlies portions of the roadways and infrastructure at the DCPP site. 2.2 Probabilistic Seismic Hazard Analysis 2.2.1 Probabilistic Seismic Hazard Analysis Results In accordance with the March 12, 2012 50.54(f) letter (NRC 2012) a site-specific probabilistic seismic hazard assessment was completed for DCPP's site. The assessment used an updated seismic source characterization (SSC) model and an updated GMC model as basic inputs. The SSC and GMC studies were undertaken to fulfill the NRC requirement that PG&E conduct a probabilistic seismic hazard assessment using SSHAC Level 3 procedures for DCPP. as specified by the NRC (NRC 2012). Thus, the SSC and GMC models were developed using processes that are appropriate for a SSHAC Level 3 study, as described in NUREG/CR-6372 (NRC 1997), and the detailed implementation guidance provided in NUREG-2117 (NRC 2012b). Both the SSC and GMC models represent new or "replacement" models according to the definitions and instructions in NUREG-2117. The SSC model describes the future earthquake potential (e.g., magnitudes, locations, and rates) for the region surrounding the DCPP site, and the GMC model describes the distribution of the ground motion as a function of magnitude, style of faulting, source-to-site geometry and reference site condition. The DCPP SSC model includes fault and areal seismic sources out to and beyond the 320 km (200 mi.) DCPP site region. The SSC model focuses on those sources that contribute most to hazard at DCPP: the Hosgri, Los Osos, San Luis Bay, and Shoreline fault sources, called the primary fault sources, and the local areal source zone, which accounts for earthquakes that occur near DCPP but off the recognized fault sources (PG&E 2015). Uncertainty and variability in earthquake ruptures that are modeled to occur on the primary and adjacent fault sources consider alternative fault geometries and fault slip rates, and include alternative connections of adjacent fault sections across which earthquake ruptures may occur. New elements in the SSC model compared to prior SSC models include fault magnitude probability density functions that allow a fault source to rupture during more common, characteristic earthquakes and rare but permissible multi-fault, maximum earthquakes. The largest earthquake considered in the SSC model is a magnitude M 8.5 on the Hosgri fault source, representing an extremely rare, but plausible, rupture between offshore Point Arguello south of DCPP and the Mendocino Triple Junction offshore Cape Mendocino in northern California. The postulated rupture would include the PG&E Letter DCL-15-035 Page 16 of 60 entire 41 O km (255 mi.) length of the Hosg ri-San Simeon-San Gregorio fault zone and an additional 330 km (205 mi.) of the northern San Andreas fault north of San Francisco. More common characteristic earthquake magnitudes on the fault sources range between M 6 and M 7.3, with strike-slip, reverse, and reverse-oblique slip senses occurring between approximately 1 O and 1 km (6 and 0.6 mi.) from DCPP at closest source-to-site distances. Another new element of the DCPP SSC model is the inclusion of uncertainty in the time-dependent nature of the earthquake occurrence rate. Instructions for implementing the SSC model are in the SSC hazard input document. Full documentation of the DCPP SSC model and the SSHAC Level 3 process is contained in the DCPP SSC Report (PG&E 2015) and is available online at www.pge.com/dcpp-ltsp. The DCPP GMC model is derived as part of a regional study addressing the ground motion characterization for two sites located in the Southwestern United States (SWUS) (DCPP and Palo Verde Nuclear Generating Station in Arizona), for a common reference site condition with Vs303 of 760 meters per second (m/s) and kappa of 0.041 seconds (sec) (GeoPentech 2015). The DCPP GMC model for the median is derived from published ground motion prediction equations wt1ich are then reparameterized into models that use a common functional form. With a set of models based on a common functional form, the covariance structure of the model coefficients can be estimated and sampled to produce a large number of alternative ground motion prediction equations (GMPEs). This large space of ground motion models is then discretized into a smaller number of representative ground motion models. A key advantage of this approach is that the weights on the alternative models represent probabilities of the ground motion models based on the discretization of the ground motion model space. The ground motion models are optimized for large magnitudes (M 5.5 to M 7.5) strike slip and reverse events at short distances(< 10 km) that dominate the hazard at DCPP. The hanging-wall effects are captured from a suite of wall adjustment models derived from the hanging-wall scaling in the existing NGA-West2 RRuP-based GMPEs. In addition to the empirically-based models, finite fault simulations were used for three purposes: (1) to constrain the hanging-wall scaling; (2). to provide an alternative data set of large magnitude near-fault ground motions for use in the evaluation of the weights for the ground motion models; and (3) to constrain the scaling of ground motions for complex and splay ruptures that are not well constrained in the empirical data sets (complex rupture refers to a case with significant (i.e., > 15 degrees) changes in rake and dip along fault strike, and splay rupture refers to a case with two faults rupturing together). The GMC model for the standard deviation for DCPP uses the partially non-ergodic approach (Al Atik et al, 201 O) in which the variability of the average site-specific amplification, not captured in the simple site scaling in the GMPEs, is removed from the within-event standard deviation. This approach provides a consistent V530 is defined as the average shear-wave velocity in the first 30 m of subsoil/rock. PG&E Letter DCL-15-035 Page 17 of 60 method for combining the uncertainty in the site-specific site amplification with the aleatory variability of the ground motion models. Instructions for implementing the GMC model are in the GMC hazard input document. Full documentation of the DCPP GMC model and the SSHAC Level 3 process is contained in the southwestern United States GMC report (GeoPentech 2015) which is available online at www.pge.com/dcpp-ltsp. 2.2.2 Base Rock Seismic Hazard Curves For the central and eastern United States (CEUS) sites, the base rock condition is a hard rock site condition (shear-wave velocity of 2800 m/s) (EPRI 2013c). For the western United States, the ground motion models are not well constrained for hard-rock conditions. Therefore, a reference rock condition for soft-rock (Vs30 = 760 m/s) is used for the base rock hazard calculation. The hazard is computed using a minimum moment magnitude of 5.0. All sources within 320 km (200 mi.) of DCPP are included in the hazard calculation, as required by Regulatory Guide 1.208 (NRC 2007). The aleatory variability is modeled using the single-station sigma approach (Al-Atik et al 2010), which removes the systematic site terms from the traditional total standard deviation. Using the single-station sigma approach requires that the epistemic uncertainty in the site terms be included. The epistemic uncertainty in the site term at each spectral frequency is included through the standard error of the empirical site term. The hazard curves by seismic source are shown in Figures 2.2.2*1 and 2.2.2-2 for 1 and 10 Hz spectral acceleration, respectively. The digital data associated with these figures are listed in Appendix A. The sources that contribute at least 5 percent to the total hazard at 1 x 10*3 hazard level are shown individually. Only the sources that come within 15 km (9 mi.) of DCPP contribute significantly (at least 5 percent) to the total hazard at any spectral period for hazard levels of 1 x 10'3 or less. The total hazard for seven frequencies is shown in Figure 2.2.2-3.

DCPP: 1 Hz 1.E-01 I ---*---* _ __I _____ .-------* I 1.E-02 1.E-03 1.E-05 -f----1.E-06 -1 I I I 1.E-07 -!1---------** ---0.01 0.1 Enclosure 1 PG&E Letter DCL-15-035 Page 18 of 60 -Total --Hosgri fault * ...... San Luis Bay fault -*--Los osos fault -----Shoreline fault --San Andreas fault -* -Other connected faults --*Other regional faults -*

• Local source zone Regional and Vicinity source zones 1 10 Spectral Acceleration (g) Figure 2.2.2-1: Reference Rock Hazard by Source for 1 Hz Spectral Acceleration

.. Ill N Ill ::c (ii ::I c c c:( 1.E-01 1.E-02 1.E-03 1.E-04 1.E-05 . l.E--06 r 1.E-07 *-----------* 0.1 1 DCPP: 10 Hz \ . -\.. Enclosure 1 PG&E Letter DCL-15-035 Page 19of60 -Total --Hoscri fault ......

• San Luis Bay fault ---Los Osos fault ----*Shoreline fault --San Andreas fault -* -Other connected faults -*
• Local source zone
• Regional and Vicinity sourc:e zones *--------------*------------* 10 100 Spectral Acceleration (g) Figure 2.2.2-2: Reference Rock Hazard by Source for 10 Hz Spectral Acceleration "E is ra 1.E-02 1 1.E-03 r-Enclosure 1 PG&E Letter DCL-15-035 Page 20of60 --! -Mean (PGA) I -Mean (20 Hz) Mean (10 Hz) -Mean(SHz) Mean (2.5 Hz) Mean (1 Hz) Mean (O.S Hz) ::c 1.E*04 ra :I c 1.E-05 \ ** .. *---------------1.E*06 ***r----------------0.1 l Spectral Acceleration (g) 10 Figure 2.2.2-3: Reference Rock Mean Hazard for PGA and 20, 10, 5, 2.5, 1, and 0.5 Hz Spectral Acceleration 2.3 Site Response Evaluation 4 The traditional approach for site response is to develop analytical models for the site amplification relative to the reference rock site condition used for computing the hazard. An alternative empirical approach is used for DCPP to account for the recorded ground motion data at DCPP4. This approach relies on the observed ground motions at the site to constrain the site amplification rather than analytical models. When site specific data are available, the empirical approach is preferred over analytical modeling. The epistemic uncertainty due to the limited number of recordings is taken into account. DCPP's seismic instrumentation system, described in Section 3. 7.4 of the DCPP UFSAR (PG&E 2013), includes several free-field recording instruments. Ground motion records from instrument nos. ESTA27 and ESTA28 (see Figure 2.3.2-4 for instrument locations) are used as input to the site response evaluation. PG&E Letter DCL-15-035 Page 21of60 The empirical site term represents the difference from the site amplification expected for a reference Vs30 of 760 m/s and the observed site amplification. It is estimated from recorded data after removing the average source and path terms from the observed ground motions at DCPP. The control point for DCPP is set at one of the free-field recording instruments (ESTA28). This control point is at elevation 26 m (85 feet (ft)). The empirical site response approach estimates the site amplification at the control point. To estimate the ground motions at other locations as part of the soil-structure interaction analyses, a three-dimensional (30) site response will be conducted in a separate study. The 30 site response will be used to compute the factors to scale the control point ground motions to other locations accounting for the lateral differences in the 30 velocity structure across the DCPP site. Equivalent one-dimensional (1 D) profiles will be developed that capture the range of the amplification from the alternative 30 velocity models in order to define the inputs for the soil-structure interaction analyses. 2.3.1 Description of Subsurface Material The volcaniclastic Tmofb subunit of the Tertiary Obispo Fm. is mapped to the bottom of the four deepest boreholes in the DCPP foundation area, as well as two deep boreholes located about 305 m (1000 ft) east-northeast of the northeastern corner of the DCPP foundation. Directly adjacent to the Tmofb subunit are other subunits of the Obispo Fm. as shown on Figure 2.1.4-1. There is considerable rock velocity variability observed in the high-resolution 30 tomographic 5 km by 5 km (3 mi. by 3 mi.) area containing the DCPP structure foundations (PG&E, 2014, Chapter 10). A substantial portion of this variability appears to be related to volcanic intrusion and alteration of the diabase subunit. Characteristics of acoustic (Vp) seismic velocities estimated using 30 tomography from active-source seismic data collected in 2011 and 2012 (PG&E 2014, Chapter 10) are briefly discussed below and then related to first-order geology in the remainder of this section. The 2011-2012 active seismic acoustic-wave (Vp) travel-time and 2013 gravity data were inverted to estimate 30 Vp in a large area containing DCPP (PG&E 2014, Chapter 10). Several additional 30 Vp inversions used successively finer grid spacing and progressively smaller maximum offset arrival time data to estimate more detailed 30 Vp in the 5 km by 5 km (3 mi. by 3 mi.) volume containing DCPP. The active seismic data were also processed to produce prestack depth-migrated 30 seismic velocity volumes containing DCPP. There is a correlation between 30 Vp and geologic units (Table 2.3.1-1). The lowest seismic velocities are associated with Quaternary surficial units and the shallowest weathered regions in Tertiary rocks beneath PG&E Letter DCL-15-035 Page 22of60 surficial units. The highest seismic velocities are associated with massive diabase. Seismic velocities in the top 300 m vary by more than a factor of 13 in DCPP's site area. Less than half this velocity range is represented by about a factor of three range in velocities between the slowest Quaternary surficial units (Vp = 0.5 kilometers per second (km/s)) and the top of competent weathered rock (Vp = 1.5 km/s). The remaining velocity variability of about a factor of four occurs within Tertiary Obispo Fm. rocks that comprise the entire rock portion of the DCPP foundation to about 300 m below sea level or more. Interpretation of 30 seismic-reflection data acquired in 2012 in a 30 migrated volume containing the DCPP foundation indicates that there is an unconformity at elevations deeper than 300 m below sea level that separates shallow Obispo rocks from either deeper older Obispo rocks or Cretaceous sandstone (PG&E, 2014, Chapter 8). Thus the entire rock portion of the 30 DCPP foundation velocity model likely consists entirely of Tertiary Obispo Fm. rocks beneath surficial deposits. PG&E Letter DCL-15-035 Page 23of60 Table 2. 3. 1-1: Generalized Irish H ii Is Vp-Geologic Un it Correlation Bin Color Vp (Figure (km/sec) (ft/sec) Geologic Unit(s) 2.3.1-1) Black 0.560 1,857 Dry soil Dark Blue 1.120 3,675 Dry soil-weathered rock Dark Green 1.676 5,512 Saturated soil-weathered rock Medium Typical Tertiary (all units except diabase), Green 2.235 7,349 weathered Ks and KJf, and KJf of the northern Irish Hills Light Green 2.794 9,186 Typical higher velocity Obispo Fm. except diabase, and KJf of the northern Irish Hills Light Blue 3.353 11,024 Typical Ks, fast Obispo Fm. (except diabase), and KJf of the northern Irish Hills Yellow 3.911 12,861 ] Typical near the top of KJf, zones around thin 1 diabase, and KJf of the northern Irish Hills Near maximum for KJf, low diabase, and Red 4.470 14,698 Monterey and Obispo Fm. in the hanging wall of the Edna fault KJf near large-scale diabase intrusions, thin Dark Red 5.029 16,535 diabase, and Monterey and Obispo Fm. near the Edna fault Purple 5.588 18,373 J Exclusively diabase Notes: Minimum velocity of the bin 1s listed. Ks= Cretaceous sandstone KJf =Franciscan complex . I The 3D Vp values and their correlative geologic units shown in Table 2.3.1-1 were developed by comparing 30 Vp values to observed geologic units throughout the Irish Hills. The table illustrates that, while there probably are unique correlations between velocity and geologic unit for the fastest and slowest velocities in the DCPP foundation area. intermediate velocities can correspond to several different rock types and geologic units of various ages that exist beneath the greater Irish Hills. Thus, seismic velocity does not, in general, uniquely distinguish one rock type or formation from another. For instance, the velocity bin of -2.2 to 2.8 km/sin Table 2.3.1 w1 captures Tertiary Monterey and lower-velocity Obispo Fm. rocks as well as weathered Cretaceous sandstone (Ks) and Franciscan rocks (KJf). Unweathered, massive Obispo diabase is likely the only high-velocity rock unit that has a unique velocity signature over its maximum velocity range of 5.5-6+ km/s (Table 2.3.1-1). Tabular and saucer-shaped high-velocity bodies are evident in east-west oriented Vp cross sections located beneath and to the north DCPP PG&E Letter DCL-15-035 Page 24 of 60 (Figures 2.1.4-1and2.3.1-1) and within the high-resolution 5 km by 5 km (3 mi. by 3 mi.) tomographic model where dense seismic travel-time measurements where obtained (PG&E 2014, Chapter 10). West A 300 200 :[ 100 c. .Q 0 iQ > Q) iii *100 -200 -300 0 0 0 0 0 0 0 0 0 -N .... "t B 300 200 'E 100 DCPP t -200 0 0 0 0 0 0 0 0 0 0 ,., <O .... 00 O> Distance (m) 0 0 0 -East 0 0 0 0 0 0 0 0 0 0 0 0 0 0 :! Vp (km/s; ftls) 0.560; 1857 1.120; 3675 1.676; 5512 2.235; 7349 ..* 2.794; 9186 3.353; 11024 3.911; 12861 4.470; 14698 5.029; 16535 5.588; 18373 Vp (km/s; ftls) 0.560; 1857 1.120; 3675 1.676; 5512 2.235; 7349 2.794; 9186 3.353; 11024 3.911; 12861 4.470; 14698 5.029; 16535 5.588; 18373 -300 +., ........... , ,,,.,..,, ......... ,,.,.., ,.,,..., .. = .. = .... = ................. ***"""* ........ ,,,...,,. **""'** ,.,.,,....,.,. **""'***** ...... , ..... "'"'""'*""'* '"""'",...,.' ,,..,.,,,,., ...... ,,.,...,,, .......... , Distance (m} Figure 2.3.1-1: Vp Cross Sections Showing High-Velocity (yellow to magenta) Saucer-Shaped Bodies (Vertical exaggeration is approximately 2: 1. Velocities listed correspond to the top of each color bin. See Figure 2.1.4-1 for cross-section locations) These high-velocity bodies have 30 shapes that are typically associated with saucer-shaped intrusive sills (PG&E 2014, Chapter 10). The shallow position of the saucer-shaped sills adjacent to, and beneath, some edges of DCPP's foundation area may in part explain observations of the diabase subunit exposed adjacent to the breakwater of intake cove (Figure 2.1.4-1 ), along the coastline southeast of DCPP, and offshore of OCPP (PG&E 2014, Chapter 9). PG&E Letter DCL-15-035 Page 25 of 60 2.3.2 Development of Base Case Profiles and Nonlinear Material Properties The traditional approach uses multiple base profiles and non-linear properties to capture the epistemic uncertainty in the site amplification. For the empirical site term approach used for DCPP, epistemic uncertainty is captured through the epistemic uncertainty of the empirical site terms rather than using uncertainty in the inputs to an analytical site response model. For DCPP, we use alternative 30 models to capture the epistemic uncertainty in the lateral variation of the ground motion across the DCPP site region. The alternative 30 velocity models were selected from a large suite of alternative models such that they appropriately capture the range of the amplification at the key structures. The epistemic uncertainty in the amplification at the control point ground motion is included in the uncertainty of the empirical site factors. To avoid double counting uncertainty, only the uncertainty in the lateral variations of the site amplification due to the alternative 30 velocity is included in the 30 site response evaluation. As an example, three alternative 30 models of the wave velocity are shown in Figures 2.3.2-1, 2.3.2-2, and 2.3.2-3. Figure 2.3.2-4 shows 1 D profiles at the control points based on the 30 models. Figure 2.3.2-1: 30 Perspective of Vs-Depth Cross Section Slices through the Amplification 30 Vs DCPP Site Model (Model 1 ). Location of Cross Section is Shown in Figure 2.3.2-4. PG&E Letter DCL-15-035 Page 26of60 Figure 2.3.2-2: 3D Perspective of Vs-Depth Cross Section Slices through the Amplification 3D Vs DCPP Site Model (Model 2). Location of Cross Section is Shown in Figure 2.3.2-4. Figure 2.3.2-3: 3D Perspective of Vs-Depth Cross Section Slices through the Amplification 3D Vs DCPP Site Model (Model 3). Location of Cross Section is Shown in Figure 2.3.2-4.

20 0 I -20 c 0 -40 llJ w -60 *80 *100 ---------ESTA27: midAmp Model ; -ESTA 28: miclAmp Model *, Turbine *-Unit I Unit l 400 600 800 1000 1200 1400 1600 1800 2000 Vs (m/s) Enclosure 1 PG&E Letter DCL-15-035 Page 27of60 180 160 140 I 120 -ro I : *so g 1 I I: I 1!0 \ I 20 . j i 0 800 -20 Figure 2.3.2-4: 1 D Velocity Model for the Control Point (ESTA 28) and Other Locations in the Plant Area 2.3.2.1 Shear Modulus and Damping Curves Shear-modulus curves and damping curves are not directly applicable to DCPP, since analytical modeling is not used. The non-linear site effects are implicitly included in the empirical GMPEs for Vs30 = 760 m/s. The non-linearity in the NGA-West2 GMPEs is generally consistent with the EPRI Peninsular Range shear-modulus curves and damping curves (Kamai et al 2014). In the Kamai et al 2014 model, there is no dependence of the site amplification on the rock ground motion level (e.g. no non-linearity) for Vs30 > 760 mis. The NGA-West2 GMPEs also have very weak or no rock ground motion level dependence on the sites amplification for V53o > 760 m/s. Therefore, the empirical site factors are applicable to high rock ground motion levels. 2.3.2.2 Kappa The kappa values are implied in the empirical GMPEs used to develop the ground motion model and in the site-specific recordings. The GMPEs used to develop the ground motion model have average (host) kappa of 0.041 sec (Appendix M of GeoPentech 2015). The issue for DCPP's empirical approach is the applicability of this host kappa to DCPP's site. The kappa for DCPP was PG&E Letter DCL-15-035 Page 28of60 evaluated using the spectral shape of the 2003 Deer Canyon earthquake (Appendix L of the 2011 Shoreline fault report (PG&E 2011)) and was found to be consistent with a kappa of 0.04 sec. Empirical evaluations of the kappa scale factors (Ktenidou and Abrahamson 2015) show that the dependence of the frequency ground motion residuals are not strongly correlated with kappa computed from the observed ground motions. They conclude that the estimated site kappa is correlated with other parameters, which limits the observed correlation of residuals and kappa. Therefore. the kappa from the empirical GMPEs used for the ground motion model is consistent with the DCPP site kappa and an adjustment for site-specific kappa or adding additional uncertainty for kappa is not warranted. 2.3.3 Randomization of Base Case Profiles Randomization of the base case profiles is not needed since DCPP is using the empirical site term approach. 2.3.4 Input Spectra An input spectrum is not required since DCPP is using the empirical site term approach. 2.3.5 Methodology The empirical site-term approach is used because site-specific empirical motion data are available at DCPP. These data provide the best information on the site response because they sample the actual conditions at DCPP. In particular. the data provide a better representation of the effects of the deeper structure (top 0.5-1 km) that are important to the kappa and to the low-frequency response. which may not be captured in the analytical modeling. A disadvantage of using site-specific empirical data is the limited number of recordings; however, this limitation is addressed by estimating the epistemic uncertainty in the site response factors based on the number of recordings and the global estimate of the standard deviation of site-specific site terms. The free-field recordings at DCPP (available from the Pacific Earthquake Engineering Research ground motion database) are used to estimate the specific effects on the ground motions relative to the reference-rock GMPEs. The ground motions at a site from a given earthquake reflect the event-specific source and attenuation effects in addition to the site-specific site effects. To isolate the site effects, the differences in the event-specific source and specific attenuation effects from the average effects captured in the GMPEs are removed. This is done by computing the mean residual at each spectral frequency over a subset of recorded ground motions from a representative distance range and then developing a source-specific estimate of the ground motion at DCPP by adding the mean residual to the median ground motion from PG&E Letter DCL-15-035 Page 29of60 each of the GMPEs. The mean residual for the selected data is different from the traditional event term used in developing GMPEs because it is for a limited distance range. This provides an estimate of not just the average source effect, but also the average path effect (difference from the distance scaling in the GMPEs). To avoid having the DCPP site effects influence the correction, the mean residual is computed without the DCPP data. Ground motions from the 2003 San Simeon and 2004 Parkfield earthquakes were selected for use in this evaluation. The 2003 Deer Canyon earthquake did not have enough recordings to constrain the mean event term independent of OCPP's recordings. Therefore, the recording from the 2003 Deer Canyon earthquake is not used in this evaluation. The mean residuals are computed for each of the five NGA-West2 GMPEs. Following the method used in the 2011 Shoreline fault report (PG&E 2011), the residuals are computed for eight recordings in the distance range of Oto 100 km (62 mi.) for the San Simeon earthquake and for 16 recordings in the distance range of 40 to 170 km (25 to 106 mi.) for the Parkfield earthquake to capture the event term in the relevant distance ranges (35 km (22 mi.) for San Simeon and 85 km (53 mi.) for Parkfield). This mean residual is used to adjust the West2 GMPEs to the event and distance specific values (e.g. remove average source and path effects). The residuals of the free-field spectral accelerations recorded at DCPP are computed with respect to the event and distance specific spectral accelerations. The 2003 San Simeon earthquake was recorded at one instrument at DCPP (ESTA27). Following the San Simeon earthquake, additional seismic instrumentation was installed, including an additional free-field instrument (ESTA28). The 2004 Parkfield earthquake was recorded at both free-field instruments (ESTA27 and ESTA28). The velocity profile at the location of instrument no. ESTA28 becomes similar to the power block5 and turbine building profiles at depths of about 100 m (see Figure 2.3.2-4 above). The profile for free-field instrument no. ESTA27 shows a different gradient and does not merge with the power block and turbine building profiles at depth as seen with the profile for ESTA28. Since the profile at instrument no. ESTA28 is more consistent with the power block and turbine building profiles, this site is selected as the control point. 2.3.6 Amplification Functions The residuals for the DCPP free-field recordings were computed (PG&E 2014, Chapter 11) for each of the five event-adjusted NGA-West2 models for a ' The term "power block" herein refers to the combination of the Unit 1 containment structure, the Unit 2 containment structures, and the common auxiliary building. PG&E Letter DCL-15-035 Page 30of60 reference rock with Vs30 = 760 m/s. The average residuals over the five GMPEs are shown on Figure 2.3-1. Overall, the frequency-dependent residuals are consistent between the two recordings over most of the frequency range, but there is a large difference at 0.5 hertz (Hz). In particular, the San Simeon residuals are much larger. The ESTA27 time histories from this earthquake show that the 0.5 Hz ground motion is coming from late-arriving surface waves, indicating different path effects for these two earthquakes. This is not seen in the Parkfield recordings at either ESTA27 or ESTA28. Since the low-frequency residual are not similar for both earthquakes, they are not consistent with a strong site effect. The variability of the low frequency amplification is included in the uncertainty of the site factor. The smoothed model is shown by the heavy black line and represents the OCPP site term relative to the reference free-field instrument no. ESTA28 with Vs30 = 753 m/s. If there was no ground motion data at a given site, then the mean site term would be zero and the epistemic uncertainty in the site term would have a standard deviation of phis2s. which is the standard deviation of the site terms from worldwide data sets. As data is recorded at the site of interest, then the mean site term can be estimated and the epistemic uncertainty reduced from the value of phis2s from global data. The source and path corrected residual at the site given an estimate of the site term. The standard error of the site terms is phis2s divided by JN, where N is the number of recordings. The uncertainty in the estimated of the source and path terms due to the limited number of recordings is added to the standard error of the site term. The standard error of the DCPP site term is listed in Table 2.3.6-1. The upper and lower ranges shown in the figure are based on+/- 1.25 times the standard error and represent the 10th and 90th confidence limits. The epistemic uncertainty in the site term has two components: the uncertainty in the estimated terms for each earthquake and the variability in the single-path within-event residuals (phiO). The uncertainty in the event-path term is given by the standard error of the estimate of the mean residual of the selected subsets of recordings (8 recordings from San Simeon and 16 recordings from Parkfield). The observed ground motion at a site is a sample from a normal distribution with a standard deviation given by the single-path within-event standard deviation (called phiO). The standard deviation of the epistemic uncertainty in the site term is given by sqrt( (SE1 /\2 + phiQA2)/4 + (SE2A2+PhiQA2)/4 ) where SE1 and SE2 are the standard errors of the path terms from San Simeon and Parkfield respectively. The value of phiO is given by Lin et al 2011. The epistemic uncertainty is modeled using a three point distribution based on -1.64. 0, and 1.64 times the standard of the epistemic uncertainty with weights of 0.2, 0.6, and 0.0, respectively. The upper and lower ranges shown in Figure 2.3.6-1 and represent the 5th and 95th confidence limits The central, upper, and lower ranges of DCPP's site-specific site term are listed in Table 2.3.6-1. The median amplification factors and epistemic uncertainty at PG&E Letter DCL-15-035 Page 31 of 60 the control point, using the empirical site response approach, are listed in Appendix A.

• San Simeon residual
• Parkfield residual Average Site-Specific Median Site-Specific -High range 1--Site-Specific -Low range ..... -' _L 0 8 -+-----+------<-*--+--+--+-+-+-+------<----+---+--1--+--<--tt--------,-f--*--+ . ti)' 0 6 . *--* -----i----< ** _ _..; ..., . -------__ .:. __ --!..-;....._ ___ __,_--+----+--+-+--+-+-+* *c: . *
• I I* I r I , ---1--::I 0.4 Pl '... .. z ------>-. + ---*---+--+-i--+f+ ---+---1---+--*-+-l-+-+-I d 0.2 -E -* -*-':--* .;.....
• H+ ..... 0 ., ..... "' _._, , ' * --* -** II :--ia..*-1!-_i. * .2? -0 2 -. -,;* Ii *1 t --I
• I *-* I. -. I (J) -: .. -*i ,i ... '-:'T'* --,.--+ . -. a.. -0. 4 . -' ,__ *-' a.. i.... .. I""": 1--*, --;--*-+----*_+/-* I ! -,-.+-----_; -r-; I ----'*--+-* *-* _,_ -;-{) . .. I ., ___ *-I l .-. I 0 6 . _,., 0 -. ----. -' ! .. -....... -* * * ----r--*j---* ---i-'T--,. -11.--*--.. -*-+---+--1-'Tf-'--i-+--+-f-++ -0.8 . I I I I _.. j ------*--r---.. --!---+--+--11---i-"l-+=l---+--_,._-+-+-+-+-++I . . 0.1 1 10 100 Frequency (Hz) Figure 2.3.6-1: Mean Event-Specific Residuals for DCPP Relative to the ESTA28 Reference Rock Site Condition with V830 = 750 m/s Note: Epistemic uncertainty (10% and 90% confidence levels) is shown by the dashed lines PG&E Letter DCL-15-035 Page 32of60 Table 2.3.6-1. DCPP Site-Specific Site Amplification Terms DCPP Site Term for Control Point (ESTA28) (natural log units) Standard -* Upper J . Lower -Deviation of Frequency DCPP Site (Hz) Term Median _Range_ . 100 -0.20 -0.3 -0.62 0.02 50 -0.20 -0.32 -0.65 0.01 34 -0.20 -0.36 -0.68 -0.04 20 -0.20 -0.52 -0.85 -0.19 13.5 -0.21 -0.52 -0.86 -0.18 10 -0.22 -0.52 -0.88 -0.16 6.7 -0.24 -0.5 -0.89 -0.11 5 -0.22 -0.38 -0.74 -0.02 4 -0.21 -0.24 -0.58 0.1 3.3 -0.21 -0.13 -0.47 0.21 2.5 -0.21 0.19 -0.15 0.53 *---*-* ---* 2 -0.22 0.19 -0.17 0.55 1.3 -0.23 0.19 -0.19 0.57 1 -0.24 0 -0.4 0.4 0.67 -0.26 0 -0.42 0.42 0.5 -0.27 0 -0.44 0.44 0.33 -0.35 0.00 0.58 -0.58 0.2 -0.35 0.00 0.58 -0.58 0.1 -0.35 0.00 0.58 -0.58 2.3.7 Control Point Seismic Hazard Curves The mean hazard for the control point is computed using a method that is consistent with approach 3 of NUREG/CR-6728 (NRC 2001). The site term is added to the median from the ground motion models developed as part of the SSHAC ground motion characterization. Epistemic uncertainty is captured by using a logic tree for the range of the site terms. The mean hazard for the control point for seven frequencies is shown in Figure 2.3.7-1 and listed in Appendix A.

Control Point Enclosure 1 PG&E Letter DCL-15-035 Page 33of60 ---. _::_:-; .. -........ '. : . I '.---+---1--*--1 **- I-! . : I l. ! .. l < I i : *--,II 1* I ' II , ' I'\.. ..... ! 1 X*' 1, I *, 1 x1 o-3 ** , I "-. I ,. ....._' -+--------_.__-+--_.__---+--+--I *-**-.------1----""i,--""*:*'--. :-, __ ;" . i----+---,-----1--f-* -t--', ', 1""-"' ..... " "'"'-_-+-, __ -_-_-_-_ -_ -_J-,_-_-___ 1x10*5-',, . "'-'-I '-i'-1 Spectral Ace (g) I i i : I I J i \ I I Figure 2.3.7-1 Control Point Mean Hazard Curves for PGA and 20, 10, 5, 2.5, 1, and 0_5 Hz Spectral Frequencies 2.4 Control Point Response Spectra 10 The uniform hazard response spectra (UHRS) for 1 x 10-4 and 1 x 10-5 hazard levels at the control point are computed from the mean hazard curves. The UHRS are plotted in Figure 2.4-1 and are listed in Table 2.4-1. The GMRS is computed following the requirements of Regulatory Guide 1.208 (NRC 2007). The GMRS is equal to the 1 x 10-4 UHRS at frequencies greater than or equal to 1 Hz. At lower frequencies, the GMRS is slightly greater than the 1 x 10-4 UHRS. PG&E Letter DCL-15*035 Page 34 of 60 Table 2.4-1 UHRS for 1 E-4 and 1 E-5, and GMRS at Control Point for DCPP -------(5% damping) Frequency Spectral Acceleration (g) (Hz) Control Point 1 E-4 Control Point 1 E-5 GMRS UHRS UHRS -.-...... -100.00 0.812 1.525 0.812 50.00 0.832 1.564 0.832 33.33 0.882 1.659 0.882 20.00 0.983 1.849 0.983 13.33 1.236 2.295 1.236 ....._ .. 10.00 1.405 2.640 1.405 6.67 1.613 3.054 1.613 5.00 1.740 3.305 1.744 4.00 1.785 3.373 1.785 -* --** 3.33 1.714 3.236 1.714 2.50 1.960 3.830 2.010 2.00 1.634 3.186 1.672 1.33 1.200 2.469 1.282 1.00 0.755 1.566 0.812 0.67 0.478 1.017 0.525 0.50 0.318 0.703 0.360 . 0.33 0.188 0.408 0.210 4 3.5 3 .-2.5 Ol -(.) (.) <( 2 ro ..... t5 (]) a. (./) 1.5 1 0.5 0 0.1 *

• Control Point UHAS (AEP=10-4) Control Point UHAS (AEP=10-5) Control Point GMRS , I I I *t . ' ! I I . 1*' 1
• I I ' ' i' .. ' .. I 11, t ' I I l I I I
• I ' ' f1v
• r... I I ' ' I 1, jY I J ' I ' # J ill I , . j I ., I < I ' 1 Frequency (Hz) * ' ' ' Enclosure 1 PG&E Letter DCL-15-035 Page 35of60 I ' I I i I I .. I I I I ! I .. l .. ... .... '"" I ! ! I r i l ' i I I ; I ... 10 100 Figure 2.4-1 UHRS for 1E-4 and 1E-5, and GMRS at Control Point for DCPP PG&E Letter DC L-15-035 Page 36 of 60 3.0 Plant Design, Licensing, and LTSP Evaluation Bases Ground Motions The seismic design, licensing, and LTSP evaluation bases for DCPP are identified in Sections 2.5, 3.1, and 3.7 of the UFSAR, Revision 21 (PG&E 2013) the Hosgri Report (PG&E 1980), the 1988 L TSP Final Report (PG&E 1988), and the 1991 Addendum to the L TSP Final Report (PG&E 1991 ). Since the development of the seismic design/licensing basis for DCPP predates the issuance of Appendix A to 10 CFR 100 (NRC 1973) site-specific criteria and methods were employed in the development of the design/licensing basis ground motions. The seismic design, licensing, and LTSP evaluation of DCPP includes the following earthquakes: 1. Design Earthquake (0.20g PGA) The DE is defined in UFSAR Section 2.5.3.10.1 based on the maximum size earthquakes that can be expected to occur at DCPP during the life of the reactor. Four earthquakes of varying magnitudes and distances were postulated (described as Earthquake A, Earthquake 8, Earthquake C, and Earthquake D in UFSAR Section 2.5.3.9.1 ). The postulated ground motions at DCPP for these four earthquakes were based on empirical data, with certain modifications based on input from the Atomic Energy Commission and their consultants. As described in UFSAR Section 2.5.3.10.1, Earthquakes B and D were found to be governing over Earthquakes A and C. In addition, based on meetings between PG&E, the Atomic Energy Commission, and the Atomic Energy Commission's consultants, the shape of the response spectra associated with Earthquake D was modified and the accelerations associated with Earthquake B were increased by 25 percent. After the incorporation of the modifications, the following two earthquake ground motions were selected to represent the DE for DCPP: (a) Earthquake D-modified, derived by modifying the S80°E component of the 1957 Golden Gate Park. San Francisco earthquake, and then normalizing to a maximum ground acceleration of 0.20 g. The smoothed response spectrum for this earthquake is shown in UFSAR Figure 2.5*21. (b) Earthquake B, derived by normalizing the N69°W component of the 1952 Taft earthquake to a maximum ground acceleration of 0.15 g. The smoothed response spectrum for Earthquake Bis shown in UFSAR Figure 2.5-20. PG&E Letter OCL-15-035 Page 37of60 Seismic design for the DE is based on the envelope of Earthquake B and Earthquake 0-modified. 2. Double Design Earthquake (0.40g PGA) The DOE is defined in UFSAR Section 2.5.3.10.2 as an earthquake having twice the maximum ground acceleration and response spectra as those associated with the DE. 3. 1977 Hosgri Earthquake (0. 75g PGA) The 1977 HE is defined in UFSAR Section 2.5.3.10.3 as the predicted ground motion at DCPP associated with a Richter magnitude 7.5 earthquake on the Hosgri fault at a point nearest to DCPP. There are two ground motion definitions associated with the HE: (a) The Newmark HE, is an earthquake developed by Dr. N. M. Newmark, having an effective maximum horizontal ground acceleration of 0.75 g. The smoothed response spectrum for the Newmark HE is shown in UFSAR Figure 2.5-30. (b) The Blume HE, is an earthquake developed by Dr. J. A. Blume based on empirical data associated with strong-motion time histories recorded on rock close to the epicenters, and normalized to a 0.75 g peak acceleration. The smoothed response spectrum for the Blume HE is shown in UFSAR Figure 2.5-29. The seismic design for the HE is summarized in Supplement No. 5 to the NRC's Safety Evaluation Report (SER) for OCPP (NRC 1976) and is based on the envelope of the loadings associated with the Newmark HE and the Blume HE. The HE is the largest ground motion considered in the seismic design of OCPP. 4. Long Term Seismic Program Earthquake (0.83 g PGA) The L TSPE is associated with license condition 2. C. (7) of the OCPP Unit 1 operating license, that required, in part: "PG&E shall develop and implement a program to reevaluate the seismic design bases used for the OCPP." PG&E's reevaluation effort in response to the license condition was titled the "Long Term Seismic Program." The L TSPE is defined in UFSAR Section 2.5.3.10.4 as the predicted ground motion at OCPP associated with a moment magnitude 7.2 earthquake on the Hosgri fault approximately 4.5 km (3 mi.) from OCPP. PG&E Letter DCL-15-035 Page 38 of 60 The L TSP included both a SPRA and a deterministic SMA. The results of the L TSP are described in the 1988 L TSP Final Report (PG&E 1988) and the 1991 Addend urn to the L TSP Final Report (PG&E 1991 ). The L TSP evaluation concluded that the structures, systems, and components previously qualified for the DE, DOE, and 1977 HE seismic loads remained qualified for the LTSPE. The NRC's review and acceptance of the LTSP evaluations are documented in Supplement No. 34 of the SER for DCPP (NRC 1991). 3.1 Description of Response Spectra Shapes 3.1.1 Double Design Earthquake Response Spectrum The ODE response spectrum, which corresponds to an envelope of the 5 percent damped horizontal Earthquake B (UFSAR Figure 2.5-20) response spectrum and the 5 percent damped Earthquake 0-modified response spectrum (UFSAR Figure2.5-21), multiplied byafactoroftwo, is tabulated in Table3.1.1-1 and illustrated in Figure 3.1.1-1.

I Enclosure 1 PG&E Letter DCL-15-035 Page 39of60 Table 3.1 1-1: DOE Response Spectrum for DCPP (5% DamQing) ----** Period Frequency Spectral Acceleration . __ .Jsec) (Hz) (g) 0.010 100.000 0.400 0.050 20.000 0.400 -* *-0.060 16.667 0.432 0.070 14.286 0.498 0.080 12.500 0.666 0.090 11.111 0.930 0.100 10.000 1.266 0.110 9.091 1.386 .-0.120 8.333 1.434 0.130 7.692 1.464 0.140 7.143 1.476 0.150 6.667 1.473 0.160 6.250 1.467 0.170 5.882 1.443 0.180 5.556 1.413 0.200 5.000 1.338 0.250 4.000 1.182 0.290 3.448 1.047 0.300 3.333 1.005 0.320 3.125 1.009 0.330 3.030 1.005 0.350 2.857 0.993 ****---* 0.380 2.632 0.963 0.500 2.000 0.786 0.580 1.724 0.705 0.660 1.515 0.639 0.740 1.351 0.609 -. 0.880 1.136 0.595 1.000 1.000 0.594 - 1 6 v -..... § L_ Enclosure 1 PG&E Letter DCL-15-035 Page 40of60 -DOE J / LI c 12 .. Oi l u L >--->----* *---/ l 0.8 -04 0.0 I 00 1000 Frequency (Hzl Figure 3.1.1-1: ODE Response Spectrum for DCPP (5% Damping) 3.1.2 1977 Hosgri Earthquake Response Spectrum I 100.00 The 1977 HE response spectrum, which corresponds to an envelope of the 5 percent damped horizontal Newmark HE response spectrum (UFSAR Figure 2.5-30) and the 5 percent damped horizontal Blume HE response spectrum (UFSAR Figure 2.5-29), is tabulated in Table 3.1.2-1 and illustrated in Figure 3.1.2-1. PG&E Letter DCL-15-035 Page 41of60 Table 3.1.2-1: 1977 HE Response Spectrum6 for DCPP (5% Damping) ._ .... ____ , Period Frequency Spectral Acceleration (sec) (Hz) (g) 0.010 100.000 0.750 0.029 34.000 0.750 0.032 31.000 0.784 0.040 25.000 0.912 0.050 20.000 1.067 0.063 16.000 1.248 0.071 14.000 1.371 -... 0.083 12.000 1.528 0.100 10.000 1.737 0.111 9.000 1.870 0.125 8.000 2.032 0.174 5.750 2.032 0.182 5.500 2.044 0.190 5.250 2.061 0.200 5.000 2.080 0.217 4.600 2.106 0.238 4.200 2.128 0.250 4.000 2.125 0.263 3.800 2.118 0.278 3.600 2.111 0.303 3.300 2.075 0.333 3.000 2.032 0.435 2.300 2.032 0.455 ' 2.200 1.975 0.500 2.000 1.795 0.556 1.800 1.616 0.625 1.600 1.436 0.714 1.400 1.257 0.800 1.250 1.124 1.000 1.000 0.898 1.538 0.650 0.586 --* 2.000 0.500 0.411 6 The spectral acceleration values represent the envelope of the Newmark HE (UFSAR Figure 2.5-30) and the Blume HE (UFSAR Figure 2.5-29). Note that the HE response spectra have been extrapolated to a minimum frequency of 0.50 Hz for this application. 2.5 2.0 o.s 0.0 0.10 ----v ..... ' -f J I I/"". I *' , 1.00 Frequency (Hz) ....... ' \ Enclosure 1 PG&E Letter DCL-15-035 Page 42 of 60 -t<E(IJFSAA) 1--*HE ! \. 10.00 100.00 Figure 3.1.2-1: 1977 HE Response Spectrum for DCPP (5% Damping) 3.1.3 Long Term Seismic Program Earthquake Spectrum The 5 percent damped horizontal 84th percentile of non-exceedance 1991 L TSPE response spectrum (UFSAR Figure 2.5-33), is tabulated in Table 3.1.3-1 and illustrated in Figure 3.1.3-1. PG&E Letter DCL-15-035 Page 43of60 Table 3.1.3-1: 1991 L TSPE 84th Percentile Response Spectrum for DCPP (5% Damping) Period Frequency Spectral Acceleration (sec) (Hz) (g) 0.010 100.000 0.830 0.025 40.000 0.830 ---0.030 33.000 0.830 0.040 25.000 0.964 0.050 20.000 1.110 0.070 14.286 1.344 0.085 11.765 1.508 0.100 10.000 1.654 0.120 8.333 1.819 0.140 7.143 1.918 0.150 6.667 1.947 0.170 5.882 1.976 0.200 5.000 2.006 -* --* 0.250 4.000 2.015 0.300 3.333 1.962 0.400 2.500 1.763 0.500 2.000 1.554 0.750 1.333 1.109 1.000 1.000 0.831 1.500 0.667 0.524 2.000 0.500 0.356 2.5 2.0 !.:! 0.5 0.0 D.10 ,; :/;> I ) '.l 1.00 :I ' ... *' l ' / ' *' .> ...... fJeQuency tHz) v ....... i\ \ Enclosure 1 PG&E Letter DCL-15-035 Page 44of60 I -\i19! LTSP I \ .\ . "* ', '** >-oH 10,00 Figure 3.1.3-1: 1991 L TSPE 84th Percentile Response Spectrum for DCPP (5% Damping) 3.2 Control Point Elevation 7 The control point elevation for DCPP's ODE is defined based on the criteria provided in Section 2.4.2 of the SPID (EPRI 2013a). As shown on UFSAR Figures 2.5-15, 2.5-16, and 2.5-17, all original surface materials (soil and rock) were removed from the locations of the major structures7 and their foundations were excavated into the bedrock. Therefore, the major structures are rock-founded. The free-field ground motions, associated with the DOE (described in Section 3.1.1) and the 1977 HE (described in Section 3.1.2), are used as input to all structures at DCPP. The UFSAR does not explicitly define a control point for the ground motions, but it can be derived from the seismic analyses of structures described in UFSAR Section 3.7. Based on a review of the seismic analyses of the major structures, as described in UFSAR Section 3.7.2.1.7. the control point for the seismic analyses is the finished grade level, which corresponds to Major structures at OCPP include the containment structures, the auxiliary building, and the turbine building. PG&E Letter DCL-15-035 Page 45 of 60 26 m (85 ft) mean sea level at the location of the major structures (see UFSAR Figure 2.5-18). This is consistent with the control point elevation associated with the site response evaluation, as described in Section 2.3. Since the site-amplification studies associated with the GMRS (Section 2.4) are developed based on the free-field recordings of historical earthquakes affecting DCPP, the control point is specifically at the location of free-field seismic instrument no. ESTA28 (located in the yard area at elevation 26 m (85 ft). approximately 96 m (316 ft) north of the centerline of the Un it 1 containment structure and 2.4 m (8 ft) east of a north-south line passing through the centerlines of the Unit 1 and Unit 2 containment structures -see Figure 2.3.2-4). See Section 2.3.5 for additional information on the selection of the control point. PG&E Letter DCL-15-035 Page 46of60 4.0 Screening Evaluation In accordance with Section 3 of the SPID, a screening evaluation was performed, as described in the following subsections. As stated in the NRC's letter to PG&E dated October 12, 2012 (NRC 2012c), "for the purposes of the response to the March 12, 2012 request for information, the NRC staff expects PG&E to use the DOE for comparison with the reevaluated seismic hazard GMRS." Therefore, the following screening evaluations are based on the DOE. 4.1 Risk Evaluation Screening (1 to 10 Hz) § c .2 -e .!! .. u "iD .. u .. Q, Cl.I The GMRS exceeds the DOE in the 1 to 10 Hz frequency range, as shown in Figure 4. Therefore DC PP screens-in for a risk evaluation. 30 25 20 1.$ 1.0 o.s 0.0 0.10 y / I I '* I ' : I I ' I-' ' _J *x '1 */ / .,, 1' **"' * ! i 1 I I I l 1.00 Frequency {Hz) 1-Gr.tRS I -oce 'I'-.-. .,. "' ' \ ............. """-........ 10.00 Figure 4.1-1: Comparison of GMRS and DOE Spectrum for DCPP (5% Damping) 100.00 4.2 High Frequency Screening(> 10 Hz) The GMRS exceeds the DOE for frequencies greater than 10 Hz, as shown in Figure 4.1-1. This exceedance will be addressed in the required risk evaluation. 4.3 Spent Fuel Pool Evaluation Screening (1 to 10 Hz) Enclosure 1 PG&E Letter DCL-15-035 Page 47 of 60 The GMRS exceeds the ODE in the 1 to 10 Hz frequency range, as shown in Figure 4. 1-1 . Therefore DC PP screens-in for a SFP evaluation. Note that at DCPP the SFPs are located in the fuel handling area of the auxiliary building. 5.0 Interim Evaluation Enclosure 1 PG&E Letter Page 48 of 60 Consistent with the NRG letter dated February 20, 2014, (NRG 2014) the seismic hazard reevaluations presented herein are distinct from the current design and licensing bases of DCPP. Consequently, the results of these analyses performed using present-day regulatory guidance, methodologies, and information would not generally be expected to call into question the operability or functionality of structures, systems, and components, and are not reportable pursuant to 10 CFR 50.72 or 10 CFR 50.73. The NRC's March 12, 2012 10 CFR 50.54(f) letter (NRC 2012) and February 20, 2014 supplemental letter (NRC 2014) request that Licensees submit an interim evaluation or actions taken or planned to address the reevaluated hazard where it exceeds the current design basis, if necessary prior to completion of the risk evaluation. PG&E's interim evaluation is based on comparisons of the beyond design basis GMRS to the design/licensing basis 1977 HE and the 1988 L TSP evaluations: (a) 1977 HE Evaluation All Design Class I structures. systems, and components at DCPP, including the SFPs8, have been designed/evaluated for the design/licensing basis 1977 HE spectrum and found to meet the HE acceptance criteria (PG&E 1980 and NRC 1978b). A comparison of the GMRS with the design/licensing basis 1977 HE spectrum is shown in Figure 5.0-1. This comparison indicates that, with the exception of an exceedance of approximately 0.09 g (7 percent) at 1.33 Hz, the GMRS is bounded by the design/licensing basis 1977 HE spectrum at all frequencies in the 1 to 10 Hz frequency range (frequency range associated with the risk evaluation screening). The exceedance is insignificant because no structure, system, or component required for safe shutdown is susceptible to the 1.33 Hz frequency (Tables 6-24 and 6-25 of PG&E 1988). The GMRS also exceeds the design/licensing basis 1977 HE spectrum for frequencies> 24 Hz. As stated in Section 3.4 of the SPID (EPRI 2013a): "high-frequency vibratory motions above about 10 Hz are not damaging to the large majority of (nuclear power plant] structures, components, and equipment. An exception to this is the functional performance of vibration sensitive components, such as relays and 6 As indicated in Section 4.3, the SFPs are located in the fuel handling area of the auxiliary building. which is a Design Class I structure. § c 0 .. .. Cl .. u '"' ii .. ... u " a. I/) 9 3.0 2.5 2.0 1.5 10 0.0 0.10 Enclosure 1 PG&E Letter Page 49 of 60 other electrical and instrumentation devices whose output signals could be affected by high-frequency excitations." Therefore, in accordance with Section 3.4 of the SPID (EPRI 2013a), the results of the design/licensing basis 1977 HE evaluation demonstrate that all Design Class I structures, systems, and components are capable of resisting the ground motions associated with the GMRS with exception of the high-frequency sensitive equipment. The impact of the high-frequency exceedance is addressed as part of the L TSP evaluation, discussed below. -GURS -HE(UFS.-'IR) v ........ ---HE ---If' ' -.. ' ) ...... ..... \ I ,( i-.-. lit.. *' 1.00 10.00 100.00 Frequency (Hz) Figure 5.0-1: Comparison of GMRS and 1977 HE Design Spectrum for DCPP (5% Damping) (b) 1988 LTSP Evaluation All structures9, systems, and components required for safe shutdown 10 have been evaluated for the 1988 L TSP spectrum and found to have The auxiliary building. which contains the SFPs, is included in the scope of the LTSP evaluation. 10 The safe shutdown-related structures, systems, and components addressed in the 1988 L TSP are listed in Tables 7 -1 and 7-2 of the 1988 L TSP Final Report {PG&E 1988) 3.0 2.5 2.0 0.5 Enclosure 1 PG&E Letter DCL-15-035 Page 50 of 60 significant seismic margins (see Appendix B for discussion of the LTSP seismic margins). A comparison of the GMRS with the L TSP seismic margin spectrum is shown in Figure 5.0-2. This comparison indicates that the GMRS is bounded by the LTSP seismic margin spectrum at all frequencies, including 1.33 Hz and those > 24 Hz -frequencies where the GMRS exceeds the design/licensing basis 1977 HE spectrum. Therefore, comparing the results of the revised GMRS against the 1988 L TSP evaluation demonstrate that all structures, systems, and components required for safe shutdown, including vibration sensitive components, have a significant seismic design margin beyond the GMRS. -er.IRS -. : ... -LTSP Seismic r.1 argln Spectrum / \ I \ .' /\ \ . I I v ......... ' ,/ J \ ...... , \ // "!'. I\ *\ .. '* ----/ I r-....... .....__ I II / I / *I /" 00 0.10 100 10.0*) 100.00 Frequency (Hz) Figure 5.0-2: Comparison of GMRS and LTSP Seismic Margin Spectrum for DCPP (5% Damping} Based on the above comparisons to the design/licensing basis 1977 HE evaluation and the 1988 L TSP evaluation, there is reasonable assurance that DCPP remains safe to operate without undue risk to the public while an updated risk evaluation is being performed. PG&E Letter DCL-15-035 Page 51 of 60 The consideration of potential loss of the water inventory from the SFPs, as described in Section 7 of the SPID (EPRI 2013a), has been addressed as part of the NTTF Recommendation 2.3: Seismic Walkdowns, as discussed in Section 5.2. The results of these walkdowns demonstrated that the potential for loss of the water inventory from the SFPs (e.g., rapid draindown) has been adequately addressed in the design and construction of DCPP's SFPs. Further evaluatrons of the potential loss of the water inventory from the SFPs will be performed once an NRC-endorsed guidance has been developed. 5. 1 Expedited Seismic Evaluation Process The ESEP, as proposed in the NEl's letter to the NRC, dated April 9, 2013 (NEI 2013) and confirmed in NRC letter dated May 7, 2013 (NRC 2013), is described in EPRI Technical Report No. 3002000704 (EPRI 2013b). The ESEP was intended as an interim measure to provide additional assurance of safety in cases where the GMRS significantly exceeds the plant design/licensing basis while additional risk evaluations (i.e., SMA, or SPRA) were being performed. However, as discussed in Section 5.0, the DCPP GMRS is bounded by other previous seismic evaluations, including the design/licensing basis 1977 HE evaluations and the 1988 LTSP evaluation. Therefore. there are no additional benefits in performing this activity in parallel with the more robust risk evaluation associated with updating/upgrading the SPRA. PG&E will devote the critical skilled resources to expediting the update/upgrade of the SPRA in order to gain additional risk insights in a timely manner. 5.2 Walkdowns to Address NRC Fukushima NTTF Recommendation 2.3: Seismic In response to the NRC's March 12, 2012 50.54(f) letter Fukushima NTTF Recommendation 2.3: Seismic (NRC 2012), PG&E performed walkdowns of the configuration of specific equipment and components in accordance with EPRI Technical Report No. 1025286 (EPRI 2012), as endorsed by the NRC in their letter dated May 31, 2012 (NRC 2012a). The goals of these walkdowns were to (a) verify that the current plant configuration was in accordance with the licensing basis; (b) verify that the current maintenance plans were adequate to maintain the plant configuration in accordance with the licensing basis; and (c) identify any seismic vulnerabilities. The potential for loss of water inventory from the SFPs (e.g., rapid draindown) was included in the scope of these walkdowns. The walkdowns of DCPP, Units 1 and 2, as documented in several PG&E letters to the NRC (PG&E 2012, PG&E 2012a, PG&E 2013b, and PG&E 2014a) identified a number of potentially adverse seismic conditions, which were entered into the DCPP corrective action program. The engineering evaluations of the potentially adverse seismic conditions determined that they did not adversely affect the performance of any required safety functions. including the ability to maintain the water inventory of the SFPs during a seismic event. Therefore, PG&E Letter DCL-15-035 Page 52 of 60 these walkdowns confirmed that the configuration of DCPP is within its seismic design/licensing basis and provided additional assurance of seismic safety. The NRC has reviewed the DCPP NTTF Recommendation 2.3: Seismic walkdown submittal reports and the results of their staff assessment (NRC 2014a) concluded that sufficient information was provided by PG&E to be responsive to the requirements of their March 12, 2012 10 CFR 50.54(f) letter (NRC 2012). 6.0 Conclusions Enclosure 1 PG&E Letter DCL-15-035 Page 53of60 PG&E completed a seismic hazard and screening evaluation for DCPP in accordance with the NRC's Fukushima 10 CFR 50.54(f) request for information letter (NRC 2012), and consistent with the NRC endorsed SPID guidelines (EPRI 2013a). A GMRS was developed solely for the purpose of screening for additional evaluations in accordance with the SPID. The DCPP GMRS exceeds the design and licensing basis DOE spectrum in both the 1 to 10 Hz range and above 10 Hz. Therefore, an updated risk evaluation and a SFP evaluation for potential loss of water inventory, in accordance with the SPID (EPRI 2013a) will be performed. PG&E also compared the GMRS with the L TSP seismic margin spectrum, described in Section 5.0. The comparison shows that DCPP's structures, systems and components required for safe shutdown and the SFPs have significant design margins beyond the GMRS. In addition, the results of the Fukushima NTTF Recommendation 2.3: Seismic walkdowns. described in Section 5.2, show that the potential for loss of water inventory from the SFPs has been adequately addressed. Therefore, DCPP remains safe to operate without undue risk to the public while an updated risk evaluation and detailed SFP evaluation for potential loss of water inventory are being performed. PG&E will perform an update to the SPRA in accordance with the EPRI guidance (EPRI 2013a) in support of the resolution of Fukushima NTTF Recommendation 2.1: Seismic. PG&E believes that since there are no additional insights to be gained from an implementation of an ESEP, PG&E will devote its resources to performing a more robust SPRA. PG&E will perform additional evaluations of the SFPs to address potential loss of water inventory in accordance with the EPRI guidance (EPRI 2013a) and any additional NRC endorsed guidance that may be issued. The completion dates for the SPRA and SFP evaluations will be based on the schedule as defined in NEl's letter to the NRC, dated April 9, 2013 (NEI 2013) and confirmed in NRC's letter, dated May 7. 2013 (NRC 2013). 7.0 References 7.1 Electric Power Research Institute Enclosure 1 PG&E Letter DCL-15-035 Page 54of60 (a) EPRI 2012, "Seismic Walkdown Guidance for the Resolution of Fukushima Near-Term Task Force Recommendation 2.3: Seismic," Technical Report No. 1025286, dated June 2012 (b) EPRI 2013a, "Seismic Evaluation Guidance -Screening, Prioritization and Implementation Details (SPID) for the Resolution of Fukushima Near-Term Task Force Recommendation 2.1: Seismic," Technical Report No. 1025287, dated February 2013 (c) EPRI 2013b, "Seismic Evaluation Guidance: Augmented Approach for the Resolution of Fukushima Near-Term Task Force Recommendation 2.1: Seismic," Technical Report No. 3002000704, dated April 2013 (d) EPRI 2013c, EPRI (2004, 2006) Ground-Motion Model (GMM) Review Project," Technical Report No. 3002000717, 2 Volumes, dated June 2013 7.2 Pacific Gas and Electric Company (a) PG&E 1980, PG&E Report, "Seismic Evaluation for Postulated 7.5M Hosgri Earthquake -Units 1 and 2, Diablo Canyon Site," transmitted to the NRC as Amendment Nos. 50, 53, 54, 56, 59, 60, 62, 64, 66, 68, 70, 72. 75, 76, 77, 79, 82, and 83 to the Operating License Application for Diablo Canyon Power Plants Units 1 and 2," dated June 3, 1977 through June 6, 1980 (b) PG&E 1988, PG&E Report, "Final Report of the Diablo Canyon Long Term Seismic Program for the Diablo Canyon Power Plant," Enclosure to PG&E Letter DCL-88-192, "Long Term Seismic Program Completion," dated July 31, 1988 (c) PG&E 1990, PG&E Report, "Additional Deterministic Evaluations Performed to Assess Seismic Margins of the Diablo Canyon Power Plant. Units 1 and 2," Enclosure to PG&E Letter DCL-90-226, "Long Term Seismic Program Additional Deterministic Evaluations," dated September 18, 1990 (d) PG&E 1991, PG&E Report, "Addendum to the 1988 Final Report of the Diablo Canyon Long Term Seismic Program," Enclosure to PG&E Letter DCL-91-027, "Addendum to Long Term Seismic Program Final Report, dated February 13, 1991 PG&E Letter DCL-15-035 Page 55 of 60 (e) PG&E 2011, PG&E Report, "Report on the Analysis of the Shoreline Fault Zone, Central Coastal California, report to the U.S. Nuclear Regulatory Commission," Enclosure to PG&E Letter DCL-11-005, "Report on the Analysis of the Shoreline Fault Zone, Central Coastal California," dated January 7, 2011 (f) PG&E 2012, PG&E Letter DCL-12-118, "Response to Request for Information Pursuant to 10 CFR 50.54(f) Regarding Recommendation 2.3 Seismic Unit 1," dated November 27, 2012 (g) PG&E 2012a, PG&E Letter DCL-12-119, "Response to Request for Information Pursuant to 10 CFR 50.54(f) Regarding Recommendation 2.3 Seismic Unit 2," dated November 27, 2012 (h) PG&E 2013, "Diablo Canyon Power Plant Units 1 & 2 Final Safety Analysis Report Update," Revision 21, dated September 2013 (i) PG&E 2013b, PG&E Letter DCL-13-054. "Response Amendment to Request for Information Pursuant to 10 CFR 50.54(f) Regarding Recommendation 2.3 Seismic," DCPP Unit 2, dated May 22, 2013 (j) PG&E 2013d, PG&E Letter DCL-13-044, "Response to NRC Request for Information Pursuant to 10 CFR 50.54(f) Regarding the Seismic Aspects of Recommendation 2.1 of the Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accident," dated April 29, 2013 (k) PG&E, 2014, PG&E Report, "Central Coastal California Seismic Imaging Project Report to the California Public Utilities Commission." Enclosure to PG&E Letter DCL-14-081, "Central Coastal California Seismic Imaging Project, Shoreline Fault Commitment," dated September 10, 2014 (I) PG&E 2014a, PG&E Letter DCL-14-041, "Response Update to Request for Information Pursuant to 10 CFR 50.54(f) Regarding Recommendation 2.3 Seismic Unit 1 .dated May 8, 2014 (m) PG&E 2015, "Seismic Source Characterization for Probabilistic Seismic Hazard Analysis for the Diablo Canyon Power Plant, San Luis Obispo County, California," Report on the Results of the SSHAC Level 3 Study in Partial Compliance with NRC Letter 50.54(f). dated March 2015. 7.3 United States Nuclear Regulatory Commission (a) NRC 1973. "Seismic and Geologic Siting Criteria for Nuclear Power Plants," Appendix A to Part 100, "Reactor Site Criteria," of Title 10, "Energy," of the Code of Federal Regulations, dated December 13, 1973 PG&E Letter DCL-15-035 Page 56of60 (b) NRC 1976, "Supplement No. 5 to the Safety Evaluation Report by the Office of Nuclear Reactor Regulation. U.D. Nuclear Regulatory Commission, in the Matter of Pacific Gas and Electric Company, Diablo Canyon Nuclear Power Station, Units 1 and 2, Docket Nos. 50-275 and 50-323," NUREG-0675, Supplement No. 5, dated September 10. 1976 (c) NRC 1978a. "Seismic Design Classification," Regulatory Guide 1.29, Revision 3, dated September 1978 (d) NRC 1978b, "Supplement No. 7 to the Safety Evaluation Report by the Office of Nuclear Reactor Regulation, U.D. Nuclear Regulatory Commission, in the Matter of Pacific Gas and Electric Company, Diablo Canyon Nuclear Power Station, Units 1 and 2, Docket Nos. 50-275 and 50-323," NUREG-0675, Supplement No. 7, dated May 26, 1978 (e) NRC 1991. "Safety Evaluation Report related to the operation of Diablo Canyon Nuclear Power Plant, Units 1 and 2, Docket Nos. 50-275 and 50-323, Pacific Gas and Electric Company," NUREG-0675, Supplement No. 34, dated June 1991 (f) NRC 1997. "Recommendations for Probabilistic Seismic Hazard Analysis: Guidance on Uncertainty and Use of Experts -Main Report," NUREG/CR-6372, Volume 1, dated April 1997 (g) NRC 2001, "Technical Basis for Revision of Regulatory Guidance on Design Ground Motions: Hazard* and Consistent Ground Motion Spectra Guidelines," NUREG/CR-6728, dated November 6, 2001 (h) NRC 2007, "A Performance-Based Approach to Define the Site-Specific Earthquake Ground Motion," Regulatory Guide 1.208, dated March 2007 (i) NRC 2012, letter from Eric J. Leeds (NRC) to All Power Reactor Licensees and Holders of Construction Permits in Active or Deferred Status, "Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Recommendations 2.1, 2.3, and 9.3 of the Near-Term Task Force Review of Insights from the Fukushima Dai-lchi Accident," dated March 12, 2012 (ADAMS Accession No. ML 12056A046) G) NRC 2012a, letter from David L. Skeen (NRC) to Adrian P. Heymer (NEI), "Endorsement of Electric Power Research Institute (EPRI) Draft Report 1025286, 'Seismic Walkdown Guidance', dated May 31, 2012 PG&E Letter DCL-15-035 Page 57of60 (k) NRC 2012b, "Practical Implementation Guidelines for SSHAC Level 3 and 4 Hazard Studies," NUREG-2117, Revision 1, dated April 2012 (I) NRC 2012c, letter from Joseph M. Sebrosky (NRC) to Edward P. Halpin (PG&E), "Diablo Canyon Power Plant, Unit Nos. 1 and 2 -NRC Review of Shoreline Fault (TAC Nos. ME5306 and ME5307)," dated October 12, 2012 (m) NRC 2013, letter from Eric J. Leeds (NRC) to Joseph E. Pollack (NEI}, "Electric Power Research Institutes Final Draft Report XXXXX, 'Seismic Evaluation Guidance: Augmented Approach for the Resolution of Fukushima Near-Term Task Force Recommendation 2.1: Seismic,' As an Acceptable Alternative to the March 12, 2012, Information Request for Seismic Reevaluations," dated May 7, 2013 (ADAMS Accession No. ML 13106A331)11 (n) NRC 2014, letter from Eric J. Leeds (NRC) to All Power Reactor Licensees and Holders of Construction Permits in Active or Deferred Status on the Enclosed List, "Supplemental Information Related to Request for Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Seismic Hazards Reevaluations for Recommendation 2. 1 of the Near-Term Task Force Review of Insights from the Fukushima Dai-lchi Accident," dated February 20, 2014 (ADAMS Accession No. ML 14030A046) (o) NRC 2014a. letter from James Kim (NRC) to Edward 0. Halpin (PG&E). "Diablo Canyon Power Plant, Units 1 and 2 -Staff Assessment of the Seismic Walkdown Reports Supporting Implementation of Near-Term Task Force Recommendation 2.3 Related to the Fukushima Dai-lchi Nuclear Power Plant Accident (TAC Nos. MF0117 and MF0118)," dated March 14, 2014. (p} NRC 2014c, memorandum from Nicholas J. DiFrancesco (Senior Project Manager, Japan Lessons-Learned Division) to Sheena A. Whaley (Chief. Japan Lessons-Learned Division), "Summary of October 27, 2014, Category 2 Public Meeting with the Nuclear Energy Institute to Discuss Seismic Hazard Reevaluations Associated with Implementation of Japan Lessons-Learned Near-Term Task Force Recommendation 2.1, Seismic," dated December 15, 2014 (ADAMS Accession No. ML 143078726) 11 EPRI Draft Report XXXXX referenced in the title of this letter corresponds to EPRI Technical Report No. 3002000704 (EPRI 2013b}. PG&E Letter DCL-15-035 Page 58of60 (q) NRC 2014d, memorandum from Nicholas J. DiFrancesco (Senior Project Manager, Japan Lessons-Learned Division) to Sheena A. Whaley (Chief, Japan Lessons-Learned Division), "Summary of December 4, 2014, Category 2 Public Meeting with the Nuclear Energy Institute to Discuss Seismic Hazard Reevaluations for the Western United States Sites Associated with Implementation of Japan Lessons-Learned Near-Term Task Force Recommendation 2.1, Seismic, dated December 15, 2014 (ADAMS Accession No. ML 14342A901) 7.4 Nuclear Energy Institute (a) NEI 2013, letter from Anthony R. Pietrangelo (NEI) to David L. Skeen (NRC), "Proposed Path Forward for NTTF Recommendation 2.1 Seismic Reevaluations, dated April 9. 2013 (ADAMS Accession No. ML 13101A379) 7.5 Other (a) Al-Atik, L., Abrahamson, N., Bommer, J., Scherbaum, F., Cotton, F .* Kuehn, N. 2010, "The Variability of Ground-Motion Prediction Models and Its Components, Seismological Research Letters, Volume 81, Issue 5, pp. 794-801. (b) DeMets, C., Marquez-Azua, B., and Cabral-Cano, E. 2014, "A new GPS velocity field tor the Pacific Plate -Part 1: constraints on plate motion, intraplate deformation, and the viscosity of Pacific basin asthenosphere" Geophysical Journal International. Volume 199: 1878-1899. (c) GeoPentech 2015, "Southwestern United States Ground Motion Characterization SSHAC Level 3," Technical Report, Revision 1, dated February 2015 (d) Hanson, K.L., and Lettis, W.R. 1994, "Estimated Pleistocene slip rate for the San Simeon fault zone, south-central coastal California: in Alterman, 1.B., McMullen, RB., Cluff, LS., and Slemmons, D.B. (editors), Seismotectonics of the Central California Coast Range, Geological Society of America Special Paper 292, pp. 133-150 (e) Hardebeck, J.L. 2010, "Seismotectonics and fault structure of the California central coast," Bulletin of the Seismological Society of America, Volume 100, Issue 3: pp 1031-1050. (f) Hardebeck. J.L. 2013. "Geometry and earthquake potential of the Shoreline Fault, Central California," Bulletin of the Seismological Society of America Volume 103, Issue 1: pp 447-462 PG&E Letter DCL-15-035 Page 59of60 (g} Johnson, S.Y., Hartwell, S.R., and Dartnell, P. 2014, "Offset of Latest Pleistocene shoreface reveal slip rate on the Hosgri strike-slip fault, offshore central California," Bulletin of the Seismological Society of America, Volume 104, Issue 4, doi:10.1785/012013057. (h) Kamai, R., Abrahamson, N., Silva, W. 2014, "Nonlinear Horizontal Site Amplification for Constraining the NGA-West2 GMPEs," Earthquake Spectra, Volume 30, Issue 3. pp. 1223-1240 (i) Ktenidou, 0. and N. Abrahamson. 2015 "A methodology for the selection of data and the estimation of kappa (K) for hard rock sites in the NGA databases," Pacific Earthquake Engineering Research Center, PEER Report 2015/03. 0) Lin, P., N. Abrahamson, M. Walling, C.-T. Lee, B. Chiou, and C. C., Heng, 2011, "Repeatable path effects on the standard deviation for empirical ground-motion models," Bulletin of the Seismological Society of America, Volume 101, pp. 2281-2295. (k) Lettis, W.R., and Hall, N.T. 1994, "Los Osos fault zone, San Luis Obispo County, California: in Alterman, 1.8., McMullen, R.B., Cluff. LS .. and Slemmons, D.8. (editors), Seismotectonics of the Central California Coast Ranges," Geological Society of America Special Paper 292, pp. 73-102, and Plate 5. (I) Lettis, W.R., Kelson, K.I., Wesling, J.R., Angell, M., Hanson, K.L.. and Hall, N. T. 1994, "Quaternary deformation of the San Luis Range, San Luis Obispo County, California," in Alterman, 1.8., McMullen, R.B., Cluff, LS., and Slemmons, D.B. (editors), Seismotectonics of the Central California Coast Ranges. Geological Society of America Special Paper 292, pp. 111-132. (m) Lettis, W.R., Hanson, K.L, Unruh, J.R., Mclaren, M.K., Savage, W.U. 2004, "Quaternary Tectonic Setting of South-Central Coastal California," U.S. Geological Survey Bulletin, 1995 (AA): pp. 1-21. (n) Mclaren, M.K., and Savage, W.U. 2001, "Seismicity of South-Central Coastal California: October 1987 through January 1997, Bulletin of the Seismological Society of America, Volume 91, Issue 4: 1629-1658. PG&E Letter DCL-15-035 Page 60 of 60 (o) Willingham, C.R., Rietman, J.D., Heck, R.G., and Lettis, W.R. 2013, "Characterization of the Hosgri Fault Zone and adjacent structures in the offshore Santa Maria Basin, south-central California: in Keller, M.A. (editor), Evolution of Sedimentary Basins/Onshore Oil and Gas Investigations-Santa Maria Province," U.S. Geological Survey Bulletin 1995-CC, pp. 105 (revised version of 1995 report). PG&E Letter DCL-15-035 Appendix A Page 1of13 Appendix A -Additional Seismic Hazard Curve Data A 1.0 Hazard for the Reference Rock Site Enclosure 1 PG&E Letter DCL-15-035 Appendix A Page 2 of 13 The mean hazard by source for the reference rock site are listed in Table A 1.0-1 for 10 Hz spectral acceleration and in Table A 1.0-2 for 1 Hz spectral acceleration. The deaggregation of the mean hazard at the 1 x 10-4 hazard level for 10 and 1 Hz are shown in Figures A 1.0-1 and A 1.0-2, respectively. The degregation shows that the hazard at OCPP at the 1 x 10-4 hazard level is controlled by nearby earthquakes(< 10 km) with moment magnitudes (M) in the M6 to MS range. A2.0 Hazard for the Control Point The mean hazard for the control point and the fractiles of the hazard, that capture the epistemic uncertainty, are listed in Tables A2.0-1 through A2.0-7 for the peak acceleration and six spectral frequencies: 20, 10, 5, 2.5, 1, and 0.5 Hz. A3.0 Site Amplification for the Control Point The median amplification (from the reference rock site to the control point) is listed in Table A3.0-1. The epistemic uncertainty in the median amplification is quantified by the logarithmic standard deviation listed in Table A3.0-1. The non-linear effects are captured addressed by the empirical ground motion models used for the reference rock site (Vs30= 760 mis and kappa= 0.041 seconds). The aleatory variability of the site response is captured by the standard deviation of the empirical ground motions. The single-station sigma approach removes the differences in the site-specific site amplification from the traditional ergodic standard deviation, but the single-station sigma approach does not remove the aleatory variability in the site amplification from the empirically-based standard deviations. PG&E Letter DCL-15-035 Appendix A Page 3of13 Table A1 .0-1. Mean Hazard by Source for the Reference Rock Site for 10 Hz -Spectral Acceleration. ViGiffi.t y-San 6'3tlffie-10 Hz Los Luis Local San Other ;;oReOthE r PSA Total Hosgri Shoreline Osos Bay source Andreas connected regional (a) Hazard fault fault fault fault zone fault faults faults 4.4E-8.3E-4.8E-0.01 3.9E-01 2.1 E-02 3.9E-04 04 7.1E-04 04 9.0E-02 2.1E-03 4.1E-8.0E-9.3E-0.05 7.SE-02 1.0E-02 2.7E-04 04 5.8E-04 1.9E-02 1.3E-03 3.4E-7.3E-036,e.E-3.6E-0.1 3.1 E-02 6.5E-03 2.2E-04 04 5.2E-04 G3 5.9E-03 8.5E-04 ... ___ -2 lE-6.2E-031.,..JE-1.1E-0.2 1.2E-02 3.?E-03 1.7E-04 04 4.SE-04 93 1.4E-03 4.6E-04 Q3.1-,2£..Q3 9.4E-4.4E-04.:\-:-&e-2.2E-0.4 4.6E-03 1.SE-03 1.1E-04 04 3.4E-04 04 1.SE-04 1.BE-04 2.8E-2.1E-04.f.,.2E-2.1E-0.8 1.5E-03 6.SE-04 5.9E-05 04 1.9E-04 05 1.0E-05 3.9E-05 0544E--05 6.0E-5.6E-058AE-1.5E-1.5 3.?E-04 1.6E-04 1.SE-05 05 6.SE-05 o+

• 5.5E-07 5.2E-06 06&.+E-Op .. 2.5E-2.5E-052-:2-E-4.1 E-2.0 1.6E-04 6.?E-05 8.2E-06 05 3.1E-05 o+ 1.3E-07 1.7E-06 0 7.(;..-0 *-6.2E-6.6E-062.,9£-5.6E-3.0 4.1E-05 1.6E-05 2.2E-06 06 9.0E-06 08 1.3E-08 3.3E-07 oai,.:le-Ol< 8.5E-' 9.6E-07+.8E-3.5E-5.0 5.?E-06 2.1 E-06 3.1E-07 07 1.4E-06 09 5.9E-10 3.2E-08 093,-lE-O.B --* 4 OE-4.8E-082 . .SE-4.BE-10.0 2.?E-07 8.9E-08 1.5E-08 08 7.4E-08 14 3.1 E-12 9.2E-10 11 9A E -4 P *------Table A1 .0-2: Mean Hazard by Source for the Reference Rock Site for 1 Hz Spectral Acceleration. ViGffii Y-&eUH e-Regiooal WAel 1 Hz Los Local San Other her PSA Total Hosgri Shoreline Osos San Luis source Andreas connected regio1 a (g) Hazard fault fault fault Bay fault zone fault faults I faul s 0.01 1.SE-01 7.BE-03 ! 2.?E-04 7.6E-04 5.6E-04 3.7E-4.BE-02 1.1E-03 3.4E 0.05 1.6E-02 2.SE-03 1.4E-04 5.3E-04 3.BE-04 0.1 5.0E-03 1.3E-03 9.6E-05 3.9E-04 2.9E-04 --*-*-0.2 1.6E-03 6.8E-04 5.7E-05 1.9E-04 1.6E-04 -----*----* 0.4 4.SE-04 2.6E-04 2.1E-05 4.6E-05 5.2E-05 0,8 8.0E-05 5.4E-05 3.9E-06 5.3E-06 9.2E-06 1.5 1.0E-05 7.4E-06 5.2E-07 4.SE-07 1.2E-06 2.0 3.6E-06 2.6E-06 1.BE-07 1.4E-07 4.0E-07 3.0 6.9E-07 5.2E-07 3.6E-08 2.2E-08 7.7E-08 5.0 7.2E-08 5.4E-08 3.9E-09 1.7E-09 7.9E-09 1.2E-5.2E-Q4 1.8E-G5 4 SE-06 Enclosure 1 PG&E Letter DCL-15-035 Appendix A Page 4 of 13 02&.-B-OJ 2.4E 031-,-t-4.2E-03 4.6E-04 Q4 5.0E 04W 9.BE-04 2.1E-04 94 5.9E 053.:-9 1.3E-04 5.4E-05 Q5 4.2E 06d.:+ 9.7E-06 7.1E-06 00 *-*-* 6.SE-1.8E 06-1.1 E-072-.-5 07 4.7E-07 5.SE-07 Q+ 7.2E-7.2E 074.2E-09 1.9E-08 3.7E-08 Qg 2.3E-1.4E 078,.J&-093-. ..g +o 3.9E-09 9.4E-09 09 4.2E-1.2E 087:-2-E-104,.7 1-3.SE-10 1.2E-09 lO 4.0E-3.5E 092-:4E-122.,.7 +2 1.1E-11 7.2E-11 1-1-.... .... t;-.... t;-t;-

"Cl :; 0.18 . :11 I ::c 0.16 *1 s 0.14 lj I 6 0.12 .i j 0.1 i *s I 8 0.08. 0.06 .! QI I r o.o4 *1 c QI :::! QI Cl.. DCPP: 10 Hz, AEP=l0-4 Distance (km) Enclosure 1 PG&E Letter OCL-15-035 Appendix A Page 5of13 -->8.0 Figure A 1.0-1: Deaggregation of the Reference Rock Site Hazard for 10 Hz Spectral Acceleration for the 1 E-4 Hazard Level.

0.25 N "' % s 0.2 -, IS I = 0.15 -

J:t 0.1 ' ., ; i N o.o5 c ., G1 Q,, 0 DCPP: 1 Hz, AEP=l0-4 ! ' Distance (km} Enclosure 1 PG&E Letter DCL-15-035 Appendix A Page 6 of 13 ------------------*-------------------* Figure A 1.0-2: Deaggregation of the Reference Rock Site Hazard for 1 Hz Spectral Acceleration for the 1 E-4 Hazard Level. PG&E Letter OCL-15-035 Appendix A Page 7of13 Table A2. 0-1: Mean and F ractiles of Hazard for the Control Point for Peak Acceleration _ Mean 5'" 16tn som 84tn 95tn 0.02 7.0E-02 4.4E-02 4.9E-02 7.5E-02 I 1.2E-01 1.2E-01 0.05 2.3E-02 1.1E-02 1.4E-02 2.3E-02 3.SE-02 3.SE-02 0.10 8.4E-03 3.5E-03 4.6E-03 8.4E-03 1.4E-02 1.5E-02 0.15 4.6E-03 1.6E-03 2.2E-03 4.3E-03 7.2E-03 I 8.5E-03 0.20 2.SE-03 9.1E-04 1.4E-03 2.?E-03 4.7E-03 5.7E-03 0.25 2.0E-03 5.2E-04 8.3E-04 1.?E-03 3.3E-03 4.2E-03 *-* 0.30 1.4E-03 2.BE-04 4.9E-04 1.2E-03 2.4E-03 3.0E-03 *-0.40 7.3E-04 1.2E-04 2.4E-04 6.5E-04 1.5E-03 2.0E-03 0.50 4.3E-04 5.5E-05 1.2E-04 3.4E-04 8.SE-04 1.3E-03 ,....._ 0.60 2.8E-04 2.4E-05 5.SE-05 2.1E-04 5.5E-04 7.9E-04 0.70 1.7E-04 1.0E-05 2.?E-05 1.1E-04 3.SE-04 5.BE-04 .. 0.85 8.6E-05 4.1E-06 1.2E-05 5.7E-05 2.2E-04 3.5E-04 1.00 4.9E-05 1.BE-06 6.4E-06 3.1E-05 1.2E-04 ! 1.9E-04 1.20 2.6E-05 5.1E-07 2.1E-06 1.SE-05 7.1E-05 1.3E-04 1.40 1.4E-05 2.3E-07 1.0E-06 7.6E-06 3.?E-05 7.1 E-05 1.60 8.2E-06 7.8E-08 4.0E-07 4.0E-06 2.3E-05 4.7E-05 1.80 4.9E-06 3.5E-08 2.0E-07 2.2E-06 1.4E-05 3.1 E-05 2.0 3.2E-06 1.6E-08 9.5E-08 1.3E-06 8.9E-06 2.1 E-05 2.5 1.2E-06 2.1 E-09 1.6E-08 3.5E-07 3.3E-06 8.4E*06 3.0 5.0E-07 5.2E-10 3.4E-09 9.6E-08 1.3E-06 3.5E-06 4.0 1.3E-07 7.0E-11 4.3E-10 1.2E-08 2.3E-07 8.4E-07 5.0 3.8E-08 1.6E-11 1.1E-10 2.9E-09 7.2E-08 3.0E-07 -. - PG&E Letter DCL-15-035 Appendix A Page 8 of 13 Table A2.0-2: Mean and Fractiles of Hazard for the Control Point for 20 Hz Spectral Acceleration 20 Hz Mean 5rn 16tn sotn 841n 95rn PSA (g) 0.02 7.5E-02 4.4E-02 4.8E-02 7.1E-02 1.SE-01 1.6E-01 0.05 2.6E-02 1.3E-02 1.6E-02 2.6E-02 5.1E-02 5.5E-02 --0.10 1.0E-02 4.4E-03 5.7E-03 1.0E-02 2.1E-02 2.4E-02 0.15 5.SE-03 2.1E-03 2.9E-03 5.5E-03 1.2E-02 1.4E-02 >-------0.20 3.6E-03 1.2E-03 1.7E-03 3.6E-03 7.9E-03 9.4E-03 0.25 2.5E-03 7.1 E-04 1.1E-03 2.4E-03 5.8E-03 7.0E-03 0.30 1.8E-03 4.3E-04 7.2E-04 1.8E-03 4.2E-03 5.2E-03 0.40 1.0E-03 2.0E-04 3.6E-04 1.0E-03 2.7E-03 3.5E-03 I 0.50 6.6E-04 7.7E-05 1.6E-04 5.7E-04 1.8E-03 2.5E-03 I 0.60 4.0E-04 3.SE-05 8.7E-05 3.4E-04 1.2E-03 1.SE-03 0.70 2.7E-04 2.0E-05 5.0E-05 2.3E-04 9.3E-04 1.4E-03 0.85 1.6E-04 7.9E-06 2.3E-05 1.3E-04 5.9E-04 9.6E-04 1.00 9.4E-05 3.2E-06 1.1 E-05 6.7E-05 3.4E-04 6.0E-04 1.20 5.1E-05 1.3E-06 4.9E-06 3.7E-05 2.4E-04 4.4E-04 1.40 2.9E-05 4.1 E-07 1.9E-06 1.8E-05 1.4E-04 2.7E-04 1.60 1.7E-05 2.1E-07 1.0E-06 1.1E-05 9.1E-05 1.9E-04 1.80 1.1E-05 7.4E-08 4.5E-07 6.1E-06 6.0E-05 1.3E-04 2.0 7.2E-06 3.8E-08 2.4E-07 3.8E-06 3.9E-05 9.1E-05 2.5 2.8E-06 9.5E-09 6.2E-08 1.3E-06 1.6E-05 4.3E-05 3.0 1.3E-06 2.0E-09 1.SE-08 4.8E-07 7.0E-06 2.0E-05 4.0 3.3E-07 2.SE-10 2.1 E-09 8.5E-08 1.6E-06 5.7E-06 -5.0 1.2E-07 5.9E-11 I I 4.3E-10 2.2E-08 5.SE-07 2.4E PG&E Letter DCL-15-035 Appendix A Page 9of13 Table A2.0-3: Mean and Fractiles of Hazard for the Control Point for 10 Hz Spectral Acceleration ------*--.. ------10 Hz Mean 5th 16th so th a41n 95th PSA (g) --* 0.02 1.1 E-01 6.9E-02 7.SE-02 1.1 E-01 I 2.1 E-01 2.2E-01 -0.05 4.0E-02 2.0E-02 2.3E-02 4.1E-02 7.BE-02 8.4E-02 0.10 1.6E-02 6.9E-03 8.BE-03 1.7E-02 3.3E-02 3.6E-02 0.15 9.3E-03 3.5E-03 4.7E-03 9.2E-03 1.9E-02 2.1E-02 0.20 6.2E-03 2.1E-03 2.9E-03 6.1E-03 1.3E-02 1.5E-02 0.25 4.5E-03 1.4E-03 2.0E-03 4.1E-03 9.7E-03 1.1E-02 -----0.30 3.3E-03 9.3E-04 1.4E-03 3.2E-03 7.1E-03 8.6E-03 0.40 2.1E-03 4.?E-04 7.9E-04 2.0E-03 4.8E-03 5.9E-03 0.50 1.4E-03 2.3E-04 4.2E-04 1.2E-03 3.4E-03 4.3E-03 0.60 9.5E-04 1.6E-04 3.0E-04 8.5E-04 2.4E-03 3.2E-03 0.70 6.7E-04 8.4E-05 1.8E-04 6.0E-04 1.9E-03 2.6E-03 0.85 4.4E-04 3.6E-05 8.5E-05 3.?E-04 1.3E-03 1.9E-03 1.00 2.9E-04 1.?E-05 4.4E-05 2.2E-04 8.SE-04 1.3E-03 1.20 1.?E-04 8.3E-06 2.3E-05 1.3E-04 6.6E-04 9.7E-04 1.40 1.0E-04 3.8E-06 1.2E-05 7.4E-05 4.3E-04 6.SE-04 1.60 6.5E-05 1.6E-06 5.SE-06 4.6E-05 3.1E-04 4.9E-04 1.80 4.4E-05 8.5E-07 3.4E-06 3.1E-05 2.2E-04 3.7E-04 .-2.0 2.9E-05 4.7E-07 2.0E-06 2.0E-05 1.5E-04 2.7E-04 2.5 1.2E-05 7.9E-08 4.6E-07 6.9E-06 7.2E-05 1.4E-04 3.0 6.1E-06 2.9E-08 2.0E-07 3.5E-06 3.4E-05 7.6E-05 4.0 1.?E-06 4.0E-09 3.4E-08 7.2E-07 9.4E-06 2.4E-05 5.0 6.4E-07 5.6E-10 5.3E-09 2.0E-07 3.9E-06 1.1E-05 PG&E Letter DCL-15-035 Appendix A Page 10 of 13 Table A2.0-4: Mean and Fractiles of Hazard for the Control Point for 5 Hz Spectral Acceleration 5 Hz Mean *:rn----5 16111-*--501" g4tn 95m PSA (g) 0.02 1.4E-01 9.6E-02 1.0E-01 1.4E-01 2.4E-01 2.SE-01 0.05 5.4E-02 2.8E-02 3.1E-02 5.6E-02 9.0E-02 9.4E-02 --**----->-------* 0.10 2.1E-02 9.SE-03 1.2E-02 2.2E-02 3.6E-02 3.9E-02 0.15 1.2E-02 4.8E-03 6.1E-03 1.2E-02 2.0E-02 2.3E-02 0.20 7.9E-03 3.0E-03 4.0E-03 7.9E-03 1.4E-02 1.6E-02 0.25 5.7E-03 2.0E-03 2.8E-03 5.3E-03 1.0E-02 1.2E-02 0.30 4.4E-03 1.4E-03 2.0E-03 4.2E-03 7.SE-03 9.0E-03 -0.40 2.BE-03 7.SE-04 1.2E-03 2.7E-03 5.0E-03 6.1E-03 0.50 2.0E-03 4.8E-04 7.8E-04 1.7E-03 3.6E-03 4.5E-03 -0.60 1.4E-03 3.0E-04 5.1E-04 1.3E-03 2.6E-03 3.3E-03 0.70 1.0E-03 1.9E-04 3.3E-04 8.8E-04 2.1E-03 2.7E-03 0.85 6.9E-04 1.0E-04 1.9E-04 5.8E-04 1.SE-03 2.0E-03 1.00 4.9E-04 5.9E-05 1.2E-04 3.7E-04 9.9E-04 1.4E-03 1.20 3.1E-04 2.SE-05 5.6E-05 2.4E-04 7.6E-04 1.1E-03 1.40 2.0E-04 1.SE-05 3.SE-05 1.4E-04 5.1E-04 7.SE-04 1.60 1.3E-04 7.3E-06 1.9E-05 9.4E-05 3.8E-04 5.8E-04 1.80 9.0E-05 4.2E-06 1.2E-05 6.2E-05 2.?E-04 4.3E-04 2.0 6.4E-05 1.8E-06 6.2E-06 4.2E-05 2.0E-04 3.3E-04 2.5 2.8E-05 4.9E-07 2.1E-06 1.7E-05 9.9E-05 1.8E-04 -----** 3.0 1.4E-05 1.9E-07 9.2E-07 8.6E-06 5.1E-05 9.6E-05 4.0 4.SE-06 2.7E-08 1.SE-07 2.1E-06 1.5E-05 3.2E-05 ---. -5.0 1.?E-06 3.BE-09 3.3E-08 6.6E-07 6.4E-06 1.SE-05 ---- PG&E Letter DCL-15-035 Appendix A Page 11of13 Table A2.0-5: Mean and Fractiles of Hazard for the Control Point for 2.5 Hz Spectral Acceleration 0.02 2.0E-01 l 1.SE-01 1.6E-01 1.8E-01 2.2E-01 2.4E-01 -----+ 0.05 7.4E-02 4.5E-02 4.9E-02 5.7E-02 6.9E-02 7.7E-02 ---+----l 0.10 2.9E-02 1.5E-02 1. 7E-02 2.1 E-02 2. ?E-02 3.2E-02 0.15 1.6E-02 7 .2E-03 8.SE-03 1.1 E-02 1.4E-02 1. 7E-02 0.20 1.0E-02 4.4E-03 5.3E-03 7.0E-03 9.2E-03 1.1 E-02 0.25 7.1E-03 3.0E-03 3.7E-03 4.9E-03 6.7E-03 8.1E-03 ---+-------+-----+----t-------+------+-----t 0.30 5.3E-03 2.0E-03 2.5E-03 3.SE-03 4.8E-03 5.9E-03 --4--------l 0.40 3.3E-03 1.1 E-03 1.5E-03 2.2E-03 3.1 E-03 3.8E-03 -----+-----l 0.50 2.3E-03 6.9E-04 9.3E-04 1.4E-03 2.2E-03 2.8E-03 --+-----+----+------I 0.60 1.6E-03 4.2E-04 5.9E-04 9.4E-04 1.SE-03 2.0E-03 0.70 1.2E-03 3.0E-04 4.3E-04 7.1E-04 1.2E-03 1.6E-03 ---1-----+-----+-------+----+-------I 0.85 8.3E-04 1.6E-04 2.4E-04 4.4E-04 8.2E-04 1.1 E-03 1.00 6.1 E-04 8.2E-05 1.3E-04 2.6E-04 5.2E-04 7.8E-04 1.20 3.7E-04 4.3E-05 7.4E-05 1.7E-04 3.7E-04 5.9E-04 1.40 2.SE-04 2.4E-05 4.1 E-05 9.7E-05 2.3E-04 3.9E-04 1.60 1.8E-04 1.4E-05 2.6E-05 6.6E-05 1.7E-04 2.9E-04 l-------+-------1*-1.80 1.3E-04 7.8E-06 1.5E-05 4.2E-05 1.2E-04 2.2E-04 2.0 9.4E-05 4.2E-06 9.1 E-06 2.BE-05 8.3E-05 1.6E-04 -*+------+----+-----;---------+-------t 2.5 4.6E-05 1.3E-06 3.3E-06 1.2E-05 4.0E-05 7.9E-05 3.0 2.4E-05 4.0E-07 1.2E-06 5.0E-06 2.0E-05 4.4E-05 4.0 8.4E-06 5.5E-08 1.9E-07 1.2E-06 5.8E-06 1.5E*05 5.0 3.5E-06 1.4E-08 5.7E-08 3.9E-07 f2.4E-06 6.BE-06 '------'-----'---------'------'-----'-----*- PG&E Letter DCL-15-035 Appendix A Page 12of13 Table A2.0-6: Mean and Fractiles of Hazard for the Control Point for 1 Hz Spectral Acceleration 1.0 Hz Mean 5tn 15tti sotn a4tn ! 95tn PSA (g) 0.02 6.3E-02 3.0E-02 3.2E-02 6.4E-02 I 7.2E-02 7.5E-02 -------* 0.05 1.7E-02 6.6E-03 7.7E-03 1.4E-02 1.7E-02 1.SE-02 I 0.10 5.3E-03 1.7E-03 2.3E-03 4.2E-03 5.6E-03 6.2E-03 0.15 2.7E-03 6.5E-04 1.0E-03 1.9E-03 2.9E-03 I 3.4E-03 0.20 1.7E-03 3.1E-04 5.5E-04 1.2E-03 1.9E-03 2.3E-03 0.25 1.1E-03 1.?E-04 3.4E-04 7.6E-04 1.3E-03 1.7E-03 .. 0.30 8.1E-04 8.2E-05 1.BE-04 4.BE-04 9.5E-04 ! 1.3E-03 0.40 4.8E-04 2.7E-05 7.6E-05 2.5E-04 6.0E-04 8.4E-04 0.50 2.8E-04 1.2E-05 3.6E-05 1.3E-04 3.6E-04 5.4E-04 0.60 1.8E-04 4.7E-06 1.6E-05 7.1E-05 2.2E-04 3.5E-04 0.70 1.2E-04 2.4E-06 9.1E-06 _j.5E-05 J 1.SE-04 2.6E-04 0.85 7.3E-05 9.1E-07 3.BE-06 2.3E-05 8.7E-05 1.6E-04 1.00 4.3E-05 3.4E-07 1.5E-06 1.1E-05 4.6E-05 8.BE-05 I 1.20 2.4E-05 1.2E-07 6.6E-07 5.8E-06 2.9E-05 5.9E-05 1.40 1.4E-05 4.2E-08 2.6E-07 2.7E-06 1.SE-05 3.3E-05 1.60 9.2E-06 1.BE-08 1.3E-07 1.SE-06 9.8E-06 2.2E-05 -1.80 5.9E-06 7.7E-09 6.0E-08 8.5E-07 6.2E-06 1.4E-05 -. .----2.0 4.0E-06 3.3E-09 2.BE-08 4.BE-07 3.9E-06 9.5E-06 2.5 1.7E-06 6.7E-10 6.BE-09 1.SE-07 1.SE-06 4.2E-06 -3.0 7.9E-07 1.4E-10 1.6E-09 5.0E-08 5.9E-07 1.8E-06 4.0 2.2E-07 1.3E-11 1.?E-10 6.2E-09 1.1 E-07 4.4E-07 5.0 8.2E-08 2.6E-12 4.1 E-11 1.5E-09 3.SE-08 1.7E-07 PG&E Letter DCL-15-035 Appendix A Page 13of13 Table A2.0-7: Mean and Fractiles of Hazard for the Control Point for 0.5 Hz Spectral Acceleration -0.5 Hz Mean 5tn 16tn som 84tn 95tn PSA (g} 0.02 2.0E-02 7.8E-03 9.0E-03 1.BE-02 2.2E-02 2.4E-02 ---*-* 0.05 4.5E-03 1.3E-03 1.?E-03 3.SE-03 4.?E-03 5.5E-03 0.10 1.3E-03 2.0E-04 3.4E-04 8.7E-04 1.5E-03 2.0E-03 0.15 5.6E-04 4.9E-05 1.1 E-04 3.0E-04 7.0E-04 1.1E-03 0.20 3.1 E-04 1.6E-05 4.0E-05 1.5E-04 4.2E-04 7.1E-04 0.25 1.8E-04 5.1E-06 1.5E-05 7.0E-05 2.5E-04 4.6E-04 0.30 1.2E-04 2.3E-06 7.5E-06 3.6E-05 1.6E-04 3.0E-04 0.40 5.6E-05 4.8E-07 2.1 E-06 1.4E-05 7.5E-05 1.7E-04 0.50 2.9E-05 9.8E-08 6.2E-07 5.2E-06 3.6E-05 9.2E-05 0.60 1.6E-05 4.1E-08 2.4E-07 2.4E-06 1.9E-05 5.4E-05 0.70 1.0E-05 1.1E-08 9.1 E-08 1.1E-06 1.2E-05 3.4E-05 0.85 5.5E-06 3.1E-09 I 2.9E-08 4.5E-07 5.4E-06 1.8E-05 ----1.00 3.0E-06 1.0E-09 1.1 E-08 1.7E-07 2.4E-06 1.0E-05 1.20 1.SE-06 2.3E-10 3.6E-09 7.5E-08 1.3E-06 5.5E-06 I 1.40 8.7E-07 8.2E-11 1.2E-09 2.8E-08 5.3E-07 2.7E-06 1.60 5.2E-07 3.2E-11 5.2E-10 1.3E-08 3.0E-07 1.7E-06 1.80 3.2E-07 1.3E-11 2.3E-10 6.2E-09 1.7E-07 1.1E-06 2.0 2.1 E-07 4.3E-12 8.3E-11 2.SE-09 8.9E-08 6.5E-07 I 2.5 8.0E-08 6.?E-13 9.3E-12 6.3E-10 2.9E-08 2.SE-07 3.0 3.6E-08 1.1E-13 1.1 E-12 1.4E-10 9.6E-09 9.?E-08 4.0 9.3E-09 3.8E-14 5.4E-12 1.5E-09 2.1E-08 I --5.0 3.2E-09 9.7E"16 2.3E-15 5.3E-13 3.9E-10 6.9E-09 PG&E Letter DC L-15-035 Appendix A Page 14of13 Table A3. 0-1: Median Amplification Factors and Epistemic Uncertainty for the Control Point Using the Empirical Site Response Approach. (Amplification is with respect to f k *t "th V 760 I d k 0 041 onds). a re erence roe s1ew1 S30 = ms an appa = sec logarithmic Median Standard Deviation Freq (Hz) Amplification {LN units) 100.00 0.74 0.20 50.00 0.73 0.20 33.30 0.70 0.20 20.00 0.59 0.20 13.30 0.59 0.21 10.00 0.59 0.22 6.67 0.61 0.22 5.00 0.68 0.22 4.00 0.79 0.22 3.33 0.88 0.22 2.50 1.21 0.22 2.00 1.21 0.22 1.33 1.21 0.23 1.00 1.00 0.24 0.67 1.00 0.26 0.50 1.00 0.27 0.33 1.00 0.35 0.20 1.00 0.35 0.10 1.00 0.35 PG&E Letter DCL-15-035 Appendix B Page 1 of 9 Appendix B-Long Term Seismic Program Seismic Margin Spectrum B 1.0 Introduction Enclosure 1 PG&E letter DCL-15-035 Appendix B Page 2 of 9 The purpose of this Appendix is to document the seismic margins associated with the 1988 Long Term Seismic Program (LTSP) evaluation of Diablo Canyon Power Plant (DCPP) (see the 1988 DCPP LTSP Final Report (PG&E 1988), the 1991 Addendum to the DCPP LTSP Final Report (PG&E 1991 ), and the Supplement No. 34 of the Safety Evaluation Report (SER) for DCPP (NRC 1991 )). The resulting response spectrum, herein, is defined as the LTSP seismic margin spectrum. B2.0 Long Term Seismic Program Background License Condition No. 2.C.(7) of the DCPP Unit 1 operating license, required, in part that: "PG&E shall develop and implement a program to reevaluate the seismic design bases used for the DCPP." Pacific Gas and Electric Company's (PG&E's) seismic reevaluation effort in response to the license condition was titled the "Long Term Seismic Program." The LTSP included a seismic probabilistic risk assessment (SPRA) and a deterministic seismic margin assessment (SMA). The results of the L TSP are described in the 1988 LTSP Final Report (PG&E 1988) and the 1991 Addendum to the L TSP Final Report (PG&E 1991 ). The Nuclear Regulatory Commission's (NRC's) review and acceptance of the L TSP evaluations are documented in DCPP SER Supplement 34 (NRC 1991 ). B2 .1 L TSP Ground Motion Site-specific free-field ground motions were developed by PG&E based on the following (PG&E 1988, Chapters 2 through 4): (a) regional geology, seismology, geophysics, and tectonics investigations (b) characterization of seismic source (c) characterization of ground motions, using both empirical analysis and numerical modeling PG&E's horizontal site-specific 1988 L TSP response spectrum is shown in Figure 82.1-1(PG&E1988, Figure 7-2) and tabulated in Table B2.1-1. Note PG&E Letter DCL-15-035 Appendix B Page 3of9 that the 84th percentile response spectrum was used as input to the deterministic evaluations. Z.5 .5 5%Damplng P* / '\'\ 1977 Hoseri evaluation / \: (Newmark) / 19l'!8 84tn Percentile I \ " .'/ /./ "/ .............. _._ ........................ ........ _,_...._ ..................... ........ ._._ ......... ._ .1 .2 .& 2 5 10 Froquency ltli) 20 50 100 Figure 82. 1-1: Horizontal 1988 L TSP Response Spectrum for DC PP (From LTSP Final Report, Figure 7-2) PG&E Letter DCL-15-035 Appendix B Page 4 of 9 Table 82.1-1: Horizontal 1988 L TSP Response Spectrum for OCPP (5% 0 . ) 0 ampmq Period Frequency 84m Percentile Spectral Acceleration (sec.) (Hz) (g) 0.0250 40.000 0.830 0.0303 33.000 0.830 0.0400 25.000 0.964 0.0500 20.000 1.110 0.0700 14.286 1.344 0.0850 11.765 1.508 -.--0.1000 10.000 1.654 0.1200 8.333 1.819 0.1400 7.143 1.918 0.1500 6.667 1.947 0.1700 5.882 1.976 0.2000 5.000 2.006 0.2500 4.000 2.015 0.3000 3.333 1.962 0.4000 2.500 1.763 0.5000 2.000 1.554 0.7500 1.333 1.109 1.0000 1.000 0.831 1.5000 0.667 0.524 2.0000 0.500 0.356 B2.2 L TSP HCLPF Capacities The high-confidence-low-probability-of-failure (HCLPF) capacities of structures, systems, and components that were found to be governing in the deterministic seismic margin assessment associated with the implementation of the LTSP are described in Chapter 7 of the 1988 LTSP Final Report (PG&E 1988) and updated in Chapter 7 of the 1991 Addendum of the L TSP Final Report (PG&E 1991). The fragilities and HCLPF capacities for DCPP structures, systems, and components are defined based on the 5 percent damped horizontal spectral acceleration value, averaged over the frequency range of 3.0 to 8.5 Hz. This is illustrated in Figure B2.2-1 (based on Figure 7-40 from the 1988 LTSP Final Report -PG&E 1988).

Average spectral acceleration from 3 to 8.5 Hz 3 8.5 Frequency (Hz) Enclosure 1 PG&E Letter DCL-15-035 Appendix 8 Page 5 of 9 Figure 82.2-1: Frequency Range Associated with HCLPF Capacities for DCPP (From PG&E 1988, Figure 7-40) 83.0 Minimum Seismic Margin As indicated m Tables 7-1 and 7-2 of the 1988 LTSP Final Report (PG&E 1988), the turbine building is the structure with the lowest HCLPF capacity and the emergency diesel generator (EOG) control panels are the component whose failure could lead to significant seismic risk to the plant with the lowest HCLPF capacity. The HCLPF capacities of these structures, systems, and components were updated by PG&E using the conservative deterministic failure margins method (PG&E 1990) and summarized in Table A 7-1 of the 1991 Addendum to L TSP Final Report (PG&E 1991). The HCLPF capacities for the turbine building and the EOG control panels are listed in Table 83.0-1. PG&E Letter DCL-15-035 Appendix 8 Page 6 of 9 Table 83.0-1: Limiting HCLPF Capacities for DCPP (PG&E 1988 and PG&E 1991) SSC 841h Percentile HCLPF Capacity (g) Name PG&E 19881 PG&E --Turbine Building 2.21 2.89 EOG Control Panels 2.69 2.62 Since the average 5 percent damped spectral acceleration for the 84th percentile 1988 LTSP horizontal response spectrum is 1.94 g (see Figure 82.2-1) and the HCLPF capacity for the limiting structure. system, and components (EOG control panels) is 2.62 g, the minimum seismic margin is 2.62 g/1.94 g = 1.35. Note that Section 3.8.1.5 of the NRC's SER associated with the 1988 L TSP (NRC 1991) states: "the staff generally agrees with the PG&E's statement that all components whose failure could lead to seismic risk to the plant have at least a margin of 40 percent when their HCLPF capacities are compared with the 84-percent, site-specific, ground-motion demand." Therefore, the use of a minimum seismic margin of 1.35 is conservative relative to the NRC's conclusions for the 1988 LTSP. 84.0 LTSP Seismic Margin Spectrum The resulting LTSP seismic margin spectrum is the product of the 84th percentile 1988 L TSP ground motion response spectrum (Table 82.1-1) and the minimum seismic margin from Section 83.0 (1.35). The LTSP seismic margin spectrum is shown in Figure 84.0-1 and tabulated in Table 84.0-1. 1988 HCLPF capacities are from Tables 7-1 and 7-2 of the 1988 L TSP Final Report (PG&E 1988). 1991 HCLPF capacities are from Table A7-1 of the 1991 Addendum to the l TSP Final Report (PG&E 1991). § c .2 ID 3 u c( u ID a. ..,, 30 2.5 2.0 t.5 1.0 0.5 0.0 0.10 I// .... _ v I v II II l/ I I I 00 Frequency (Hz) !"--. r---1\ \ I'\ Enclosure 1 PG&E Letter DCL-15-035 Appendix B Page 7 of 9 f -L TSP Seismic \ I\ II.. 10.00 100.00 Figure 84.0-1: LTSP Seismic Margin Spectrum for DCPP (5% Damping)

• --Enclosure 1 PG&E Letter DCL-15-035 Appendix B Page 8 of 9 Table 84.0-1: LTSP Seismic Margins Spectrum for DCPP (5% Damping} Period Frequency Spectral Acceleration (sec} (Hz} (g} 0.0100 *I----149£-=0°0°0°0° 1.121 0.0250 1.121 0.0303 I 33.0000 1.121 0.0400 25.0000 1.301 0.0500 20.0000 1.499 0.0700 14.2857 1.814 0.0850 11.7647 2.036 0.1000 10.0000 2.233 0.1200 8.3333 2.456 0.1400 7.1429 2.589 0.1500 6.6667 2.628 0.1700 5.8824 2.668 . ----0.2000 5.0000 2.708 0.2500 4.0000 2.720 0.3000 3.3333 2.649 0.4000 2.5000 2.380 0.5000 2.0000 2.098 -* 0.7500 1.3333 1.497 1.0000 1.0000 1.122 1.5000 0.6667 0.707 2.0000 0.5000 0.481 85.0 References 85.1 Pacific Gas and Electric Company Enclosure 1 PG&E Letter DCL-15-035 Appendix B Page 9 of 9 (a) PG&E 1988, PG&E Report, "Final Report of the Diablo Canyon Long Term Seismic Program for the Diablo Canyon Power Plant," Enclosure to PG&E Letter DCL-88-192, "Long Term Seismic Program Completion," dated July 31, 1988 (b) PG&E 1990, PG&E Report, "Additional Deterministic Evaluations Performed to Assess Seismic Margins of the Diablo Canyon Power Plant, Units 1 and 2," Enclosure to PG&E Letter DCL-90-226, "Long Term Seismic Program Additional Deterministic Evaluations," dated September 18, 1990 (c) PG&E 1991, PG&E Report, "Addendum to the 1988 Final Report of the Diablo Canyon Long Term Seismic Program," Enclosure to PG&E Letter DCL*91-027, "Addendum to Long Tenn Seismic Program Final Report," dated February 13, 1991 85.2 Nuclear Regulatory Commission (a) NRC 1991. "Safety Evaluation Report related to the operation of Diablo Canyon Nuclear Power Plant, Units 1 and 2, Docket Nos. 50-275 and Pacific Gas and Electric Company," NUREG-0675, Supplement No. 34, dated June 1991 PG&E Letter DCL-15-035 Appendix C Page 1of18 Appendix C -PPRP Endorsements PG&E Letter DCL-15-035 Appendix C Page 2 of 18 Diablo Canyon Seismic Source Characterization SSHAC Project Participatory Peer Review Panel Closure Letter March 10, 2015 Mr. Kent S. Ferre Project Manager Pacific Gas & Electric Company 245 Market St. San Francisco, CA 94177 Enclosure 1 PG&E Letter DCL-15-035 Appendix C Page 3 of 18

SUBJECT:

Diablo Canyon Seismic Source Characterization SSHAC Project Participatory Peer Review Panel Closure Letter

Dear Mr. Ferre,

The Participatory Peer Review Panel (PPRP, the "Panel") for the Diablo Canyon Seismic Source Characterization (SSC) SSHAC Project (the "DCPP SSC Project") is pleased to issue this PPRP Closure Letter containing our findings with respect to the project. The four Panel members (Kevin J. Coppersmith, Steven M. Day, Neal W. Driscoll, and Thomas K. Rockwell) participated in the Project in a manner fully consistent with the SSHAC Guidance 1 for a SSHAC Level 3 study. The Panel was actively engaged in all phases and activities of the Project's implementation, including the development of the Project Plan, review of analyses performed by the Technical Integration (Tl) Team to support the evaluation and integration processes, review of interim products, and review of the draft project report and the final project report. Consistent with regulatory guidance for SSHAC projects, the role of the PPRP is to conduct a review of both the process followed and the technical assessments made by the Tl Team. Accordingly, this letter documents the activities that the PPRP has undertaken in its review of the Project, its review of the adequacy of the process followed, and its findings relative to the technical adequacy of the resulting SSC model. Consistent with SSHAC Guidance, the Panel was fully engaged in peer-review interactions with the DCPP SSC Tl Team throughout the entire project from development of the Project Plan through finalization the Project Report. The participatory peer review process entails the continual review of a project from its start to its completion. Thus, proper implementation requires adequate opportunity during the conduct of the study for the PPRP to understand the data, models, and methods being evaluated; the analyses performed for the study; the Tl Team's integration activities that lead to SSC models and uncertainties; and the completeness and clarity of the technical 1 Budnitz, R.J .. G. Apostolakis, D M. Boore, L.S. Cluff, KL Coppersmith, CA Cornell, and P.A. Morris (1997). Recommendations for Probabilistic Seismic Hazard Analysis: Guidance on Uncertainty and me Use of Experts (known as the "Senior Seismic Hazard Analysis Committee Report'", or "SSHAC Guideline"), NUREG/CR-6372, U.S. Nuclear Regulatory Commission, TIC: 235076, Washington, D.C. NRG (2012). Practical Jmpfementation Guidelines for SSHAC Level 3 and 4 Hazard Studies, NUREG-2117, U.S. Nuclear Regulatory Commission, Washington. D.C. DCPP SSC PPRP Closure Letter 3-10-15 Page 1 Enclosure *1 PG&E Letter DCL-15-035 Appendix C Page 4 of 18 justifications given in the documentation. Participatory review also involves opportunities for the PPRP to provide its reviews and comments in written and verbal form during the conduct of the project, such that the suggestions and recommendations made by the Panel can be considered by the Tl Team in a timely fashion prior to completion of the work. The meetings attended and observed by the PPRP for the DCPP SSC project are summarized in the table below. The PPRP assumed an active participant role in Workshop #3 and the PPRP Briefings. . Meeting Type Date(s) Topic(s) Kick off meeting August 25, 2011 Kick off meetinQ Workshop November 29 -Workshop#1 December 1. 2011 WorkinQ Meetinq March 28, 2012 Characteristic earthauake review Working Meeting April 11. 2012 Logic tree and sensitivity for magnitude PDF and earthquake recurrence Working meeting May 14, 2012 SSC work plan review, overall logic tree structure Project and Workshop #2 planning, logic tree Working Meeting June 19-20, 2012 structure, sensitivity analyses, Hosgri, Los Osos, San Luis Bav. and Shoreline looic trees Working Meeting October 25-26, 2012 Workshop #2 planning, logic tree sensitivity review -*-Workshop November 6-8, 2012 Workshop #2 Working Meeting December 11, 2012 Review Workshop 2. 2013 plan. data needs table Working Meeting February 20. 2013 2013 Schedule and Assignments. Offshore seismic stratigrai:ihv project PE presentation Working Meeting September 20, 2013 Alternative fault model evaluation Working Meeting November 5-6, 2013 Presentation of draft SSC Model V2 Working Meeting March 5, 2014 Rupture Models, Sam Johnson PE presentation, Recurrence model Workshop March 25-27, 2014 Workshop #3 Modifications to Preliminary Fault and Working Meeting June 23-24, 2014 Deformation models, open items following Preliminary SSC Model PPRP Briefing July 24-25, 2014 DCPP SSC Model Final PPRP Briefinq, Part 1 PPRP Briefing October 31. 2014 DCPP SSC Model Final PPRP Briefing, Part 2. Time Dependency Model The PPRP, collectively and individually, understood fully the SSHAC Guidance for a structured participatory peer review and the requirements for a SSHAC Level 3 project; had full and frequent access to information and interacted extensively with the Tl Team throughout the project: provided peeMeview comments at multiple stages; and, as documented within the final report, was fully engaged to meet its peer-review obligations in an effective way. The Panel concludes that its ongoing review and DCPP SSC PPRP Closure Letter 3-10-15 Page2 PG&E Letler DCL-15-03S Appendix C Pai;!<! 5 of 18 feedback interactions with the Tl Team during the conduct of the DCPP SSC project activities fully met the expectations for a SSHAC Level 3 study. SSHAC Process Review Fundamentally. the question of whether or not a project follows a proper SSHAC Level 3 process is answered by comparing the process used with the process outlined generally in the SSHAC implementation guidance issued by the NRC. NRC (2012, Table 4-1) identifies the essential steps in a SSHAC Level 3 study that define the minimum required activities: 1. Select SSHAC Level 2. Develop Project Plan 3. Select project participants 4. Develop project database 5. Hold workshops (minimum of three, focused on available data, alternative models. and feedback) 6. Develop preliminary model(s) and Hazard Input Document (HID) 7. Perform preliminary hazard calculations and sensitivity analyses 8. Finalize models in light of feedback 9. Perform final hazard calculations and sensitivity analyses 10. Develop draft.and final project report 11. Participatory peer review of entire process Review of the project documentation, as well as ongoing participatory peer review throughout the project, leads to the conclusion that the essential steps of a SSHAC Level 3 process have been followed in the DCPP SSC Project. For example, a Project Plan was issued at the start of the project that outlined the project activities and the roles and responsibilities of all project participants; a major effort was devoted to developing a project database that was accessible to the Tl Team; three topical workshops were held to identify available data, to discuss alternative methods and models, and to present feedback based on preliminary interpretations; preliminary models were developed and seismic hazard calculations conducted to provide additional feedback to the Tl Team; draft and final reports were developed that documented the process followed and the technical assessments made; and a peer review process was conducted that included both participatory aspects and late-stage reviews (e.g., review of the draft report). In light of due consideration of the essential elements of a SSHAC process and the specific manner in which the DCPP SSC Project was conducted, the Panel concludes that the project performed all essential steps consistent with current state-of-practice guidance for a SSHAC Level 3 process. As explained in NUREG-2117 (NRC, 2012). the SSHAC process consists of two important activities, described as follows: DCPP SSC PPRP Closure Letter 3-10-15 Page3 PG&E Letter DCL-15-035 Appendii< C Page 6of 18 "The fundamental goal of a SSHAC process is to carry out properly and document completely the activities of evaluation and integration, defined as:

• Evaluation: The consideration of the complete set of data, models, and methods proposed by the larger technical community that are relevant to the hazard analysis.
• Integration: Representing the center, body, and range of technically defensible interpretations in light of the evaluation process (i.e., informed by the assessment of existing data, models, and methods)." These activities are essential to any SSHAC study and the Panel has followed the DCPP SSC Project closely to ensure that both activities have been adequately conducted. A third key activity of a SSHAC process is the documentation phase, which ensures that all evaluation and integration activities are properly supported and captured in the written record. During the Evaluation phase of the DCPP SSC Project. the Tl Team considered new data, models, and methods that have become available in the technical community in recent years. Importantly, the Tl Team evaluated the wealth of onshore and offshore data that have recently been collected as part of the AB 1632 studies required by the State of California, as well as numerous data collection activities conducted by federal and state researchers such as the USGS and California Geological Survey. Workshop #1 was devoted to reviewing these disparate datasets and to identifying which data could be used to develop the SSC model. Continuing the evaluation process, Workshop #2 focused on alternative methods and models that pertain to the hazard-significant SSC issues. Significant representation of these alternative viewpoints was made by the participation of resource and proponent experts at the workshop. The Panel concludes that the Tl Team conducted an adequate evaluation process. The Integration phase of the project entails the building of the SSC model to capture current knowledge and uncertainties. Care was given in the model-building process to appropriately distinguish between epistemic uncertainties and aleatory variability. The Tl Team conducted multiple working meetings and other interactions to ensure that the center, body, and range of technically defensible interpretations were included in the SSC model. Importantly, the Team also received appropriate communications from the Project Technical Integrator (PTI) regarding the required elements of the SSC model needed for consistency with the ground motion models being developed in parallel as part of the Southwest United States Ground Motion Characterization Project. A preliminary SSC model was developed prior to Workshop #3 and hazard calculations were conducted for purposes of sensitivity analysis feedback. At Workshop #3, the PPRP was given the opportunity to provide their feedback on the preliminary model and to challenge the Tl Team with respect to the technical justifications for their SSC model assessments and associated uncertainties. The Tl Team used the feedback gained from the hazard calculations and PPRP comments to prioritize their efforts in the final SSC model development process. The tectonic complexity of the DCPP study region requires a complex SSC model to completely and appropriately capture current DCPP SSC PPRP Closure letter 3-10-15 Page 4 PG&E Letter DCL-15-035 Appendix C Page 7 of 18 knowledge and uncertainties. Efforts were made to simplify the models when it could be shown that detailed characterization would not lead to significant differences in the hazard results. The Panel concludes that such simplifications were justified and appropriate. In support of the Documentation phase of the project, the Tl Team developed a comprehensive Draft Report that was provided to the PPRP for detailed review. To ensure that schedule constraints for the project were met, the report was provided to the PPRP in major installments consisting of multiple chapters and appendices. The role of the Panel's review was specifically to ensure that all evaluation and integration activities were described completely, and that the SSC model was adequately justified technically. Written comments were provided by the PPRP to the Tl Team and, after revision of the report in light of those comments, written responses by the Team were provided to the PPRP to ensure proper closure of each comment. Based on the review of the evaluation and integration activities conducted by the Tl Team, as well as the documentation of these activities in the PSHA report. the PPRP concludes that the SSHAC process has been adequately conducted. SSHAC Technical Review The role of the PPRP in the review of the technical aspects of the project is specified in NUREG-2117 (USNRC, 2012) as follows: "The PPRP fulfills two parallel roles. the first being technical review. This means that the PPRP is charged with ensuring that the full range of data. models, and methods have been duly considered in the assessment and also that all technical decisions are adequately and documented. The responsibility of the PPRP is to provide clear and timely feedback to the TlffFI and project manager to ensure that any technical or process deficiencies are identified at the earliest possible stage so that they can be corrected. More commonly, the PPRP provides its perspectives and advice regarding the manner in which ongoing activities can be improved or carried out more effectively. In terms of technical review, a key responsibility of the PPRP is to highlight any data, models or proponents that have not been considered. Beyond completeness, it is not within the remit of the PPRP to judge the weighting of the logic-trees in detail but rather to judge the justification provided for the models included or excluded, and for the weights applied to the logic-tree branches. Consistent with this NRC guidance. the PPRP reviewed at multiple times during the project the Tl Team's evaluations of data, models, and methods, as well as the Team's development and technical justification for the SSC model These reviews DCPP SSC PPRP Closure letter 3-10-15 Page 5 PG&E Letter DCL-15-035 Appendix C Page 8of 18 included conference calls, post-workshop meetings, written comments. and the review of drafts of the PSHA report. Through these reviews, the PPRP communicated feedback to the Tl Team regarding data and approaches that did not appear to have been considered, suggestions for methods being used within the technical community that should be evaluated by the Team, and recommendations for ways that the documentation could be improved to strengthen the discussion of the technical bases for the assessments. Requirements for a successful integrat;on or model-building phase of a SSHAC Level 3 process are that it is informed by a complete evaluation of all relevant data. models, and methods during the evaluation phase of the project, that all assessments are technically defensible, and that the developed models are thoroughly documented so as to be transparent to users. During the course of the integration process, the Tl Team found that the available set of methods or model elements were not sufficient to properly and completely represent current knowledge and uncertainty in some components of the model. In those cases, the Tl Team developed a refined set of model elements or concepts that-although they are not radically different from current practice-provide approaches that the Team concluded were more effective in modeling technical aspects than available tools. For example, the SSC model includes a series of fault geometry models and rupture sources that span the range of credible interpretations of available data. Key aspects of these rupture sources are assessed based on a consideration of constraints from geologic, geomorphic. geophysical, and seismological data. A strong requirement of the SSHAC Guidance is that all elements of the SSC model must be completely documented and adequately justified technically. This is particularly true of new model elements that have not enjoyed the benefit of use on multiple projects or that have not been subject to peer review within the larger technical community. Particularly in those cases, the PPRP must ensure that the model elements are sufficiently justified and adequately defended in the project documentation. This has been the case in the DCPP SSC Project. Examples of new approaches include the use of a slip rate allocation approach to characterizing rupture sources. incorporating new magnitude frequency distributions, and the adoption of a non-Poisson temporal model. To review these concepts and applications to the SSC model, the PPRP was present as observers at workshops where these concepts were presented, provided written comments in response to those workshops. asked questions and provided feedback in a workshop environment regarding the adequacy of the technical justification for the models, participated in briefings and conference calls related to the topics, and provided detailed written comments related to the draft project report. Based on this process of participatory review throughout the course of the project. the PPRP concludes that the bases for the SSC model elements are technically defensible, and that the technical assessments and process for arriving at the model elements are adequately documented. Throughout the course of the PPRP review. the Tl Team was responsive to the questions, comments, and suggestions made by the PPRP relative to the technical aspects of the project. Therefore. the Panel concludes that the technical aspects of the DCPP SSC PPRP Closure Letter 3-10-15 Page 6 PG&E Letter DCL-15-035 Appendix C Page 9 of 18 projects have been adequately addressed and all written comments provided by the Panel, including those made following each workshop and those pertaining to the Draft Report, are hereby considered to be closed. Conclusion Based on our observation of the completeness and professional standard by which the evaluation and integration activities were conducted, the Panel concludes that the data. models, and methods within the larger technical community have been properly evaluated, and that the center, body, and range of technically defensible interpretations have been appropriately represented in the SSC model. Accordingly, the Panel concludes that both the process and technical aspects of the DCPP SSC assessment fully meet accepted guidance and current expectations for a SSHAC Level 3 study. We appreciate the opportunity to provide our review of the project. Sincerely. DCPP PPRP Members Kevin J. Coppersmith, Chair Steven M. Day Neal W. Driscoll Thomas K. Rockwell DCPP SSC PPRP Closure Letter 3-10-15 Page 7 PG&E Letter DCL-15-035 Appendix C Page 10ol18 Participatory Peer Review Panel Closure Letter, Southwest United States Ground Motion Characterization Level 3 SSHAC Project and Tl Team -PM Response to PPRP Closure Letter PG&E Letter DCL* 15-035 Southwestern United States Appendix c Ground Motion Characterization SSHAC Level 3 Page 11of18 TECHNICAL REPORT-Rev. 2 PPRP CLOSURE LETTER March 10, 2015 Dr. Carola Di Alessandro SWUS Project Manager GeoPentech, Inc. 525 N. Cabrillo Park Drive, Suite 280 Santa Ana, CA 92701

Subject:

Participatory Peer Review Panel Closure Letter, Southwest United States Ground Motion Characterization Level 3 SSHAC Project

Dear Dr. Di Alessandro:

The Participatory Peer Review Panel (PPRP, also referred to herein as the "Panel"} for the Southwest United States (SWUS) Ground Motion Characterization (GMC) Project is pleased to issue this PPRP Closure Letter. Herein we describe our participation in the SWUS GMC SSHAC level 3 project and present our findings. Pursuant to the guidelines for a SSHAC Level 3 study (NUREG/CR-6372; NUREG-2117), the PPRP was engaged at all stages of the project, including review of the final Project Plan, Workshop agendas and participant lists; the planning of the evaluation and model integration activities: and review of the project documentation. Throughout the project, the Panel reviewed and provided regular feedback on both the process followed, and the technical assessments made. by the Technical Integrator (Tl) Team. By this letter the Panel documents the activities it has performed in the course of its review, its assessment of the process followed relative to SSHAC Level 3 expectations, and its assessment of the technical rationale underlying the GMC model. The PPRP issued a previous letter dated February 24. 2015. In that letter, the Panel noted that there were limitations in the completeness and clarity of the project documentation. Those limitations were noted as exceptions to the Panel's finding that the project successfully met SSHAC Level 3 expectations. Since that time. the Tl Team has produced a final report, designated Rev2, addressing the final set of comments from the Panel (PPRP Submittal No. 3, February 20. 2015). The Panel has reviewed Rev2 (including a short addendum supplied to the PPRP in draft form on March 9 which the Tl Team has assured in writing will be incorporated in the final version) and finds that all material concerns have been adequately addressed and are now closed. apart from one remaining exception that will be described at the end of the SSHAC Process Review section below. Two GMC models were developed for application to Diablo Canyon Power Plant (OCPP) and Palo Verde Nuclear Generating Station (PVNGS). respectively. The exception applies only to the GMC model for DCPP, and is not relevant to the case of PVNGS. 1 Appendix B -PPRP Closure Letter Page B-1 PG&E Letter DCL**r 5-035 Southwestern United States Appendix c Ground Motion Characterization SSHAC Level 3 Page 12 0118 TECHNICAL REPORT -Rev. 2 PPRP Activities in Support of the SWUS GMC Review In a SSHAC Level 3 study, the PPRP fulfills two roles. The first is that of technical review. in which the Panel ensures that the full range of data, models and methods are considered and that technical decisions and judgments are adequately justified and documented. The second is that of process review, under which the Panel ensures that the study maintains conformity with the SSHAC Level 3 guidelines. To fulfill these roles. the Panel requires adequate opportunities to gain understanding of the data being used, the analyses being performed, the Tl Team's evaluations of data and models, and the technical justifications for the Tl Team's model decisions. The table below summarizes the formal project activities in which the Panel participated. Fulfilling these roles also requires the Panel to provide regular feedback to the Tl Team during the course of the project. Jn addition to verbal feedback during Working Meetings and Workshops, the Panel provided written comments and recommendations at key stages of the project. Those written submittals are also noted in the table. Date PPRP Activitv Clune 21. 2012 Workino Meeting #1 (Planninol AU PPRP members attended. \July 1 B. 2012 Working Meeting #2 (PlaMing) All PPRP members attended. Auaust 27. 2012 Kick-off Meeting. All PPRP members attended. September 17. 2012 P PRP submittal or written oomm en ts on the Project Plan. C>ctobe r B, 2012 Working Meeting #3. PPRP representatives attended as observers. November 3. 2012 PPRP submittal or written comme11ts on revised Project Plan. November 29. 2012 PPRP submittal of PPRP endorsement letter ror Proiecl Plan. December 10, 2012 Workino Meetina #4. PPRP reoresenta1ives attended as observers. February 11, 2013 Working Meeting #5. PPRP representatives attended as observers. March 19-21, 2013 Workshop #1: Critical issues and Data Needs. All PP RP members attended as observers. The PP RP provided verbal feedback to lhe Tr Team a11he end of each da v of the Wori<shoo Amil 12, 2013 Working Meeting #6. PPR P representatives attended as observers. Amil 21, 2013 PPRP submittal of written comments on Workshop #1. Mav23, 2013 Norkina Meelin!l #7. PPRP reoresentalives attended as observers. June 24, 2013 Working Meeting #8. PPRP representatives attended as obseIVers. July 18. 2013 Workina Meeting #9. PPRP representatives attender! as observers. Auaust 21, 2013 Workina Meelina #10. PPRP reoresentatives attended as observe1s. Jclober 2, 2013 Workino Meelina PPRP reoresentalives attended as observers. 15, 2013 Working Meeting #12. PPRP representatives attended as obse1Vers October 22-24. 2013 Workshop #2: Proponent Models and Alternative Interpretations. All PPRP members attenae.d as observers. The PPRP proviaed verbal feedbac1< to tile Tl T earn at the end of each day of lhe Workshop. November 26. 2013 Workino Meeting #13. PPRP representatives :ittended as observers 3, 2013 PPRP submittal of written comments on Workshop #12. Januarv 2. 2014 Workina Meelino #14. PPRP reoresentalives attended as obseivers. January 28-29. 2014 Soecial Working Meelino. All PPRP members attendea as ot>servers March 3, 2014 Working Meelino #15. PPRP rep1ese11tatives attended as obseivers. March 10*12. 201-i Workshop #3; Preliminary GMC Models and Hazard Feedback. All PPRP me.mbers attended as participants. The PPRP provided verbal feedback lo the Tl Team at the end of each d;:iy of tile Workshop. March 24, 2014 Norkina Meetinc #16. PPRP reoresenialives attended as ubservers. April 21. 2014 PPRP submittal of written comments on Workshop #3. 2 Appendix 8

• PPRP Closure Letter Page B-2 PG&E Letter DCL*15-035 Southwestern United States Appendix c Ground Motion Characterization SSHAC Level 3 Page 13 of 18 TECHNICAL REPORT-Rev. 2 Mav 14, 2014 PPRP Closure Pre-Briefinll. All PPRP members attendee as oart1ciDants. Uulv 17*18. 2014 PPRP Closure Briefing_ All PPRP members altenaed as participants. December 13, 2014 Subm iltal No. 1 of PPRP written review com men ts on SWUS G MC Report: en ts on swus G MC Report Rev O, Chapters 7. 1 O, 11, 12, 13, and f!l.ppendices L. M, N, and R. December 16, 2014 rTe!econference, PPRP and Tl Team, to discuss the PPRP written review Submittal No. 1. Januaiy 5, 2015 Submittal No. 2 or PPRP written review commenls on swus GMC Report on SWUS GMC Report Rev.O, Cnapters 6. 8, 9, 14, and Appendices H, I, J, K. 0, andO Uanuaiy 7. 2015 rTeleconference, PPR? and Tl Team. to discuss the PPRP written review Submittal No 2. Uanuary 26, 2015 rTeh:!conference, PPRP and Tl Team, to drscuss the main mudifications introduced in SWUS GMC Report Draft Rev.1. February 9. 2015 rTeleconference, PPRP and Tl Team, to discuss observations from PPRP partial review of SWUS G MC Report Draft Rev 1. F"ebruary 16. 2015 [Teleconference, PPRP and Pmject Manager to discuss project completion ;;chedule. F"ebruary 20, 2015 No. 3 or PPRP written revie.w comments on SWUS GMC Report. Comments 011 SWuS GMC Reoort Draft Rev.1. February 24, 2015 Submittal of Closure Letter based on Draft Rev. t The PPRP finds that the level of ongoing review it was able to undertake. and the opportunities afforded the PPRP to provide feedback to the Tl Team, met the expectations for a SSHAC level 3 study. Interactions with the Tl Team provided ample opportunity for the Panel to gain an understanding of the technical bases for the Tl Team's evaluations. The Panel also was given adequate opportunity to query the Tt Team, especially in Workshop #3 and in the Pre-Closure Briefing and Closure Briefing, to assess the justification provided for their model decisions. The Tl Team provided written responses to each formal PPRP submittal, and in nearly every case the PPRP and Tl Team subsequently discussed the comments and replies in a conference call or Working Meeting. SSHAC Process Review NUREG-2117 describes the goal of a SSHAC process as being "to carry out properly and document completely the activities of evaluation and integration, defined as: Evaluation: The consideration of the complete set of data. models and methods proposed by the larger technical community that are relevant lo the hazard analysis. I nteqra lion: Representing the center. body, and range of technically defensible interpretations in light of the evaluation process (i.e., informed by the assessment of existing data, models, and methods}." During the Evaluation activities, the Tl Team considered new data, models and methods that have been introduced within the technical community since the previous seismic hazard studies were conducted for nuclear power plants in California and Arizona. The 3 Appendix B -PPRP Closure Letter Page B-3 PG&E Letler DCL-15-035 Southwestern United States Appendix c Ground Motion Characterization SSHAC Level 3 Page 14 01 18 TECHNICAL REPORT-Rev. 2 Team evaluated newly available ground motion databases, ground motion prediction equations (GMPEs), and ground motion simulation techniques. Notably, the Tl Team evaluated methods for the representation of non-Gaussian aleatory variability, as well as newly available methods for the visualization and characterization of epistemic uncertainty in ground motion prediction. The PPRP finds that the Tl Team's evaluation and the documentation thereof are consistent with the expectations for a SSHAC Level 3 study, apart from the specific reservation noted at the end of this section. The Integration phase entails thoroughly documenting the technical bases for all elements of the GMC model, to provide assurance that the center, body and range of technically defensible interpretations have been captured. The Tl Team used a new statistlcal technique to generate a suite ot representative models for median ground motion prediction that collectively represent the epistemic uncertainty in ground motion more broadly than do the published GMPEs alone. This technique is combined with a new method to select and weight the predictions of the expanded suite of models. The Tl Team's method for assigning weights is based on consideration of appropriate data sets and numerical simulations, with adequate justification. The Tl Team's model for aleatory variability and weighting of alternative aleatory models is also adequately justified, The PPRP finds that the Tl Team's GMC model integration and the documentation thereof are consistent with the expectations of a SSHAC level 3 project. apart from the specific reservation noted in the next paragraph. The Panel finds that the Tl Team's evaluation of directivity models has limitations. The Tl Team make use of a simplified directivity model to save computational time, and the final report adequately describes that model, how it is used, and some of its limitations. However, because the simplified model is unpublished, it is also necessary for the Tl Team to document that the simplified model is appropriate for the purpose ror which it is applied, in the sense that it gives results that are essentially consistent with the published and peer-reviewed model that it is intended to approximate. The final report (in the March 9 addendum) documents the performance of the simplified model through comparison with results from a hazard calculation that uses the full, publlshed directivity model. At hazard levels of 10*4 and above, the fuU model calculation confirms the conclusion obtained using the simplified model. At hazard levels below 1 o-4* however, the difference in calculated hazard between the full model and the simplified model increases with decreasing hazard level. This increasing trend has not been satisfactorily explained, has not been explored beyond the single fault case provided in the March 9 addendum. and has not been quantified in terms of impact on equal-hazard spectra at hazard levels of 10-5 and lower. Because the key rationale for the zero weighting of the directivity branch in the GMC model for periods longer than 0.5 s (the period range where the directivity effect applies) is the weak sensitivity of hazard to the directivity effect calculated using the simplified model, the PPRP finds that this weighting lacks sufficient technical justification. 4 Appendix B -PPRP Closure letter Page B-4 PG&E Letler DCL-15-035 Southwestern United States Appendix c Ground Motion Characterization SSHAC Level 3 Page 15 or1a TECHNICAL REPORT -Rev. 2 SSHAC Technical Review NUREG*2117 describes the PPRP's technical review role as follows: *'The PPRP fulfills two parallel roles, the first being technical review. This means that the PPRP is charged with ensuring that the full range of data. models, and methods have been duly considered in the assessment and also that all technical decisions are adequately justified and documented. The responsibility of the PPRP is to provide clear and timely feedback to the Tl/TFI and project manager to ensure that any technical or process deficiencies are identified at the earliest possible stage so that they can be corrected. More commonly, the PPRP provides its perspectives and advice regarding the manner in which ongoing activities can be improved or carried out more effectively. In terms of technical review, a key responsibility of the PPRP is to highlight any data. models or proponents that have not been considered. Beyond completeness, it is not within the remit of the PPRP to judge the weighting of the logic-trees in detail but rather to judge the justification provided for the models included or excluded, and for the weights applied to the logic-tree branches." As summarized in the table above, the PPRP reviewed the Tl Team's evaluations of data, models and methods on multiple occasions, and through various means, including written communications, in-person meetings, teleconferences, and review of the project report. The Panel was given adequate opportunity to question the Tl Team concerning details of their analysis, and provided feedback verbally and in writing. The Tl Team was responsive to the technical input from the Panel. The Tl Team's responses included evaluating additional data sets suggested by the Panel, undertaking additional analyses to address specific Panel technical questions or concerns, and examining and assessing alternative technical approaches suggested by the Panel. The PPRP therefore concludes that it has been afforded an adequate basis for technical assessment of the Tl Team's evaluations and model integration. As noted above in the final paragraph of the SSHAC Process Review section, the evaluation of directivity effects has been inadequate and may constitute a technical limitation of the study. Apart from that reservation, the PPRP finds that the project meets technical expectations for a SSHAC Level 3 study. Conclusion On the basis of its review of the SWUS GMC project, the PPRP finds that the project meets, with respect to both process and technical standards, the expectations for a Appendix B -PPRP Closure Letter 5 Page B*S PG&E Letter DCL-15-035 Southwestern United States Appendix c Ground Motion Characterization SSHAC Level 3 Page 16 0118 TECHNICAL REPORT-Rev. 2 SSHAC Level 3 study, with the reservation cited above. That reservation pertains specifically to application of the directivity component of the GMC model to the DCPP site. Sincerely, Steven M. Day Chair, PPRP Brian Chiou Member. PPRP Appendix B -PPRP Closure letter Kenneth W. Campbell Member. PPRP .*1 r') (--...., i , )' ,/,/ ';. J'....' -{7 / c: ,.,_:ii:'"(__ ,r:_ l , .* , ,!'.) * . -::/ Thomas K. Rockwell Member. PPRP 6 Page B-6 PG&E Leller DCL-15-035 Southwestern United States Appendix c Ground Motion Characterization SSH AC Level 3 Page 17 of 18 TECHNICAL REPORT -Rev. 2 Tl TEAM -PM RESPONSE TO PPRP CLOSURE LETTER The PPRP letter identifies a limitation of the study due to the use of the Watson-lamprey directivity model for the sensitivity studies that supported the Tl Team judgment that directivity had only a small effect on the low-frequency ground-motion hazard at DCPP. The Watson-Lamprey model provides a simplified method to include the directivity in the CY14 model in a more efficient manner by randomizing over the hypocenter locations and developing site-specific adjustments to the median and standard deviation of the ground motion for the common-form models. The limitation is related to the differences in the computed hazard if the directivity model from CY14 is applied directly into the hazard rather than using the Watson-Lamprey implementation of the CY14 directivity scaling. This limitation does not apply to PVNGS as there are no faults within 40 km of the site in the PVNGS SSC. The directivity model of CY14 reduces the directivity effects to zero for distances greater than 40 km. so there would be no directivity effects if the CY14 model was applied directly to the hazard calculations for the PVNGS site. For DCPP, the differences between the directivity effects computed using the CY14 model directly and using the Watson-Lamprey model are discussed in Section 6.S of this report. Including directivity for randomized hypocenter locations leads to additional variability of the low-frequency ground motion. This variability is combined with the total standard deviation. The key issue is if the standard deviation, developed from residuals from GMPEs that generally do not include directivity as a predictive parameter, should be reduced to account for the expected improved fit to the data if directivity parameters are included in the model. That is, should the additional aleatory variability be added to the standard deviation from the GMPEs or should it be added to a reduced standard deviation model that accounts for an improved fit if directivity parameters are included in the GMPE rnodeL The Watson-Lamprey model assumes that the standard deviations from the published GMPEs include the effects of variability due to directivity, and therefore, applies a reduction to standard deviation before adding the directivity effect on the standard deviation. If this reduction is not applied, then there will be an increase in the total standard deviation which leads to an increase in the hazard at low hazard levels_ Section 6.5 shows examples of the effect on the hazard for these two alternatives. Developing a directivity model that is consistent with the median and standard deviation of the GMPEs remains an area of research. The directivity sensitivity studies in this report that used the Watson-Lamprey model were for a period of 2 seconds. At this period, the reduction to the standard deviation in the Watson-Lamprey model is zero. Therefore, the conclusions from the hazard sensitivity for directivity are not affected by the approach of using a reduction to the standard deviation before adding the directivity effects. This Appendix B -PPRP Closure Letter Page B-7 PG&E Letter DCL-15-035 Southwestern United States Appendil( c Ground Motion Characterization SSHAC Level 3 Page 18 of 18 TECHNICAL REPORT -Rev. 2 remains an issue for periods longer than 3 seconds, but the Watson-lamprey model is not applied in the final GMC model. At a period of 3 seconds, using either approach leads to a small effect on the hazard at the lE-4 hazard level as shown in Section 6.5. The directivity effect is primarily a standard deviation effect. If the directivity effect is applied to the full standard deviation (without reduction}, then there is a potential increase of 2% to 8% for the ground motion at the lE-4 to lE-6 hazard level for T ::;; 3 seconds. This increase reflects the effect of the increased standard deviation. The range of total standard deviation models developed in Chapter 13 of this report for a period of T = 2 seconds leads to a broad range (15% to 25%} for lE-4 to lE-6, as shown in the hazard sensitivity results in Section 14. The same range of epistemic uncertainty will apply for T = 3 seconds. The Tl Team agrees that implementation of directivity into ground-motion models needs further research and that there is uncertainty in the effect of directivity on the total standard deviation, but, given that the potential range of the directivity effects is well within the range captured by the epistemic uncertainty in the total sigma logic tree, the Tl Team judges that total sigma logic tree adequately captures the potential range of the standard deviation including directivity effects. The limitation noted by the PPRP does not significantly affect the range of the standard deviation of the ground-motion model for application to DCPP. Appendix 8 -PPRP Closure letter Page B-8 Regulatory Commitments Enclosure 2 PG&E Letter DCL-15-035 PG&E is making the following regulatory commitment in this submittal: Commitment Due Date PG&E will submit the resolution of the PPRP identified To be determined request as soon as it is completed. In this submittal, Pacific Gas and Electric Company (PG&E) is revising the regulatory commitment made in PG&E Letter DCL-13-044, "Response to NRC Request for Information Pursuant to 10 CFR 50.54(f) Regarding the Seismic Aspects of Recommendation 2.1 of the Near-Term Task Force Review of Insights from the Fukushima Dai-ichi Accident," dated April 29, 2013. PG&E committed to follow the guidance provided in NEI letter, "Proposed Path Forward for NTTF Recommendation 2.1: Seismic Reevaluations," dated April 9, 2013, with two clarifications. The guidance provided in the NEI letter was to utilize the Electric Power Research Institute Report No. 1025287, "Seismic Evaluation Guidance: Screening, Prioritization, and Implementation Details (SPID) for the Resolution of Fukushima Near-Term Task Force Recommendation 2.1: Seismic," dated November 2012 for the performance of the seismic reevaluations. This commitment indicated that PG&E will perform the ground motion response spectrum comparison. PG&E's interim evaluation in preparation for the seismic probabilistic risk assessment (SPRA), as described in Enclosure 1, provides reasonable assurance that it is safe to operate DCPP while the updated/upgraded SPRA is being developed. As a result, performance of an expedited seismic evaluation process is not necessary.

Focus Area Ouestions!T opics for DCPP Public Meeting 4128 In addition to providing a general overview of the SSC and GMC SSHAC Reports and March 2015 50.54(f) response for DCPP, please provide additional clarification on the following topics. Seismic Source Characterization 1. Summarize the key data used to constrain the slip rate of the Hosgri fault, including associated uncertainties. 2. Clarify how elements of the thrust/reverse interpretation for the San Luis Range Thrust are incorporated into the SSC. 3. Clarify how the rupture models are derived from the fault source geometry models. 4. Summarize the methodology used to define the equivalent Poisson rates. Ground Motion Characterization 1. Provide additional detail on the criteria used for the selection of the candidate ground motion prediction equations (GMPEs) for development of the common form median ground motion models for DCPP. Specifically, please elaborate on the basis for including GMPEs based on datasets other than NGA-West2. 2. Provide additional detail on development of the common functional form used to fit the candidate GMPEs. Specifically, please discuss how model parameters such as depth to Vs=1 kmls and 2.5 km/s (which are present in some of the candidate GMPEs) are accounted for in the functional form. 3. Provide additional detail on the approach for weighting the selected common form models as well as the criteria used to verify the physicality of the final models. 4. Provide additional detail on how the continuous distribution for total sigma (ass) was developed by combining the between-event and within-event aleatory variabilities. Site Response 1. Section 2.3.2.1 of the 50.54(f) submittal states that shear modulus and damping curves are not directly applicable to DCPP since analytical modeling is not used and that linear site effects are implicitly included in the empirical GMPEs for Vs30=760 mis. However, the NGA-West2 database has a limited amount of data for sites with Vs30 near 760 mis and for earthquakes with magnitudes and source-to-site distances similar to those dominating the hazard for DCPP. Please provide additional information on how these limitations in the NGA-West2 database are accounted for in the site response model for DCPP. 2. Section 2.3.6 of the 50.54(f) submittal describes the development of the site term for DCPP. For the calculations of between-event residuals, provide additional information on the criteria used to determine the appropriate distance range(+ and -Rrup) to the sample station. Please discuss the sensitivity of this distance range on between-event residual values. Please provide an example calculation that uses site-specific values to determine the values for including the epistemic uncertainty in the source term. 3.0 I Diablo Canyon I 2.5 n GMRS I -!*ODE -*1 2.0 ]I I HE .2 -j1 I --L TSP 84°/oile '+-' ... *J1 I ---LTSPx1.35 Qi 1 5 *1 '-' . iH , *-.,. 11 SLB Ergo (,J .,. *II I , , 11 SLB SStn C'CS ' J:; .j1 I 14 Sh+HE+SS (,J (1) 1.0 a. "' 0.5 **n------, I I I I . -I --< * , ....

• I .. a -----,/'" , j" :7'*/* ,,_/ ,.;: "---o.o lL . 0.1 1.0 10.0 100.0 Frequency (Hz)

LICENSEE: FACILITY:

SUBJECT:

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, O.C. 20555-0001 May 27. 2015 Pacific Gas and Electric Company Diablo Canyon Power Plant. Unit Nos. 1 and 2 SUMMARY OF APRIL 28. 2015. CATEGORY 1 PUBLIC MEETING WITH PACIFIC GAS AND ELECTRIC COMPANY TO DISCUSS DIABLO CANYON POWER PLANT. UNIT NOS. 1AND2 SEISMIC HAZARD REEVALUATION ASSOCIATED WITH IMPLEMENTATION OF JAPAN LESSONS-LEARNED NEAR-TERM TASK FORCE RECOMMENDATION 2.1. SEISMIC On April 28. 20151* the U. S. Nuclear Regulatory Commission (NRC) staff held a Category 1 public meeting with the Pacific Gas and Electric Company (PG&E, the licensee) at NRC Headquarters, Two White Flint North. 11545 Rockville Pike. Rockville. Maryland. The purpose of this meeting was to discuss Diablo Canyon Power Plant. Unit Nos. 1 and 2 (Diablo Canyon) Seismic Hazard Reevaluation2 associated with the implementation of Near-Term Task Force ( NTTF) Recommendation 2. 1: Seismic of the March 12. 2012. N RC request for information issued pursuant to Title 10 to the Code of Federal Regulations Part 50, Section 50.54(f) (hereafter referred to as the 50.54(f) letter)3. During the meeting. the NRC staff provided an overview of NTTF Recommendation 2.1 "Seismic" including specifics of the review process as it relates to the Western United States (WUS) sites4 Additionally. PG&E representatives provided an overview of Diablo Canyon's seismic hazard reevaluation which included specific discussions of several focus areas identified by the staff and conveyed to PG&E before the public meeting!>. NRC staff and PG&E representatives* discussions included the following meeting highlights:

• NRC staff presented an overview of NTTF Recommendation 2.1 "Seismic" review process which included specifics on how the process would be applied to the review of the WUS submittals.
• NRC staff provided the overall schedules for Recommendation 2. 1 seismic hazard and risk evaluation activities. The staff stated that the screening and prioritization results letter for the WUS reviews would be issued by mid May 2015. Specifically. for Diablo Canyon. the plant has screened-in for further risk evaluation as a higher priority group. Subsequently. by letter dated May 13, 20156, NRC placed Diablo Canyon into the 1 The meeting notice is available via the Agencyw1de Documents Access and Management System (ADAMS) under Access:on No ML 151C5A528 ,. Diab10 Canyon's Seismic Hazard Reevaluation is available via ADAMS under Accession No. ML 1507CA6C7 3 The 50 54(f) letter and Enciosure 1 are available under ADAMS Accession Nos. ML12C53A34C and ML 12056A047, respectively.
• NRC's slide presentat!on ;s available via ADAMS under Accession No ML15117A226 ' PG&Es slide presentation rs available via ADAMS under Accession No. ML151 17 A069 *The screening and prioritization resuits for the WUS sites can be found via ADAMS under Access1on No ML 151136344 highest priority group (Group 1) for the reevaluated seismic hazard review along with 11 other reactor sites.
• The staff described the main differences between the Central and Eastern United States (CEUS) and WUS submittals. The staff emphasized the complexity of the WUS reviews and explained the reasons for anticipating that the WUS reviews may take longer to be completed than those for the CEUS.
• PG&E provided an overview of their seismic hazard reevaluation. Specifically, PG&E responded to a series of potential issues or focus areas that the staff had identified and conveyed to PG&E before the meeting7. These discussions helped the staff better understand PG&E approaches and added clarity to assist in the staff's review.
• PG&E provided additional clarification on Diablo Canyon's seismic design and licensing basis. Specifically, PG&E described their Long-Term Seismic Program margin assessment in order to demonstrate additional seismic margin and ensure plant safety while the updated risk evaluations are in progress.
• PG&E stated that they are moving forward with the seismic probabilistic risk assessment update and are currently coordinating with the Electric Power Research Institute to be one of the first licensees to complete these evaluations.
• The staff asked for clarifications in areas of the seismic reevaluation report where information appeared to be in conflict or incomplete.
• The staff indicated its plan to request from PG&E free field recordings for the Parkfield and San Simeon earthquakes used to develop the ground motion model. PG&E indicated that it will work with the staff to supplement the report with this information. Requests for additional information by the staff are also expected.
• The staff is currently evaluating PG&E's intentions not to perform the Expedited Seismic Evaluation Process and will provide a formal response. No regulatory decisions or commitments were made during the meeting. The public was invited to observe the meeting and was given an opportunity to communicate with the NRC during the public meeting before adjourning. The NRC staff received several public comments, which were addressed during the meeting and no meeting feedback forms were received. The staff received a comment from Dr. Gene Nelson (Physical Sciences professor at Cuesta College and Government Liaison for Californians for Green Nuclear Power) via email during the meeting. The NRC staff inadvertently missed the opportunity to acknowledge Dr. Nelson's comment during the meeting. According to Dr. Nelson, Diablo Canyon has favorable site conditions, which attenuate or dissipate earthquake energy over relatively short distances. Due to these favorable conditions, the primary earthquake forces seen by the plant would be dominated by nearby earthquake sources and energy transmitted to the plant would be 7 NRC Technical Focus Areas for Support of Public Meeting on April 28 can be found via ADAMS under Accession No. ML 151138360 dominated by the small section of the earthquake rupture closest to the plant. Dr. Nelson stated that when considering the information presented at the meeting of overall plant ruggedness and the seismic hazard insights discussed above, Diablo Canyon will continue to operate safely -with generous safety margins -during anticipated earthquakes. The staff received a comment via email from Rochelle Becker (Alliance for Nuclear Responsibility) after the meeting on May 12, 20158. Mrs. Becker summarized several concerns identified by the California Public Utilities Commission's Independent Peer Review Panel (IPRP) and emphasized the need for the staff to consider this information as part of its review process. The IPRP has expressed concerns regarding the modeling assumption used by PG&E to characterize soil conditions beneath the plant. In response to the comment, the staff stated that it is aware and following the IPRP activities and will consider this information as part of its review of the Diablo Canyon Seismic Hazard Screening Report supporting NTTF Recommendation 2. 1: Seismic. Rochelle Becker's (Alliance for Nuclear Responsibility) wrihen concerns can be found via ADAMS under Accession No. ML 15134A25B Please direct any inquiries to me at 301-415-1115 or by e*mail at Nicholas.DiFrancesco@nrc.gov. Docket Nos. 50-275 and 50*323

Enclosure:

List of Attendees cc w/encl: Distribution via Listserv Nicholas J. Difran sea, Senior Project Manager Hazards Management Branch Japan Lessons*Learned Division Office of Nuclear Reactor Regulation List of Attendees U.S. Nuclear Regulatory Commission Public Meeting with Pacific Gas and Electric Company to discuss Diablo Canyon's seismic hazard reevaluation associated with implementation of Japan Lessons-Learned Near-Term Task Force Recommendation 2.1. Seismic April 28. 2015 Name Lisa Walsh Clifford Muns , Diane Jackso on n ----* ! Scott Stoval ancesco Jon Ake Nicholas DiFr Mohamed Sh Vladimir Grai Frankie Vega ams zer ----Toledo . Meralis Plaza Thomas Weaver David Heeszel ---Alice Stieve ----i Nilesh Chokshi -NRC/N NRC/N

• RO RO NAC/N RO _____ 1 NAC/A NRC/R NRC/N NRC/N ... NRC/N ES ES RR RA RO AR RO --NRC/N --. NRC/N NRC/AES .NRC/NRO NAC/NAO NRC/NAO Mike Tschiltz NEI I--1---------1 (continues to next Abbreviations: NEI -Nuclear Energy Institute NMSS -Nuclear Material Safety and Safeguards NAO -Office of New Reactors NRA -Office of Nuclear Reactor Regulation RES -Off ice of Nuclear Regulatory Research Enclosure -------Name i Steve Wyman Richard Rivera-Lugo Siva P. Lingam -1 Organization NRC/NRA NRC/NRO ------NRC/NRA ------Meraj Rahimi NAC/NMSS Mike Markley NRC/NRR Tom Hipschman . NRC/RIV Ryan Alexander NRC/RIV ------Wayne Walker
• NRC/RIV Tom Farnholtz NRC/RIV ---* --------Farhanf Ostadan Bechtel 1 Dennis Damon NRC/NMSS -------* Damon Maslen Friends of the Earth --I---------Norm Abrahamson___ ar Jahangir . PG&E ----*1 ------rl Strick_land --* t PG&E m Jones PG&E ------

Ml15125A186 OFFICE NR R/JLD/JHMB/PM NAME 1 FVega --* DATE 05/15/15 -OFFICE NRR/JLD/JHMB/BC IRA/ Nicholas J. DiFrancesco, Senior Project Manager Hazards Management Branch Japan Lessons*Learned Division Office of Nuclear Reactor Regulation WWalker. A*IV Difrancesco. NRA KManoly, NRA LYong. NRA FVega, NAO MShams. NRA MMarkely. NRA RidsNrrPMDiabloCanyon RidsNrrLASLent ---*-**

• Slent 05i05/15 -....._ ---OGC (NLO) --Rids Rg n 1 Mai I Centc r RidsRgn2MailCenter RidsRgn3MailCenter RidsRgn4MailCentor RidsNrrDorl RidsOpaMail RidsNroDsea RidsNrrDe *concurrence via e-mail =::&O/OSEA/AGSIBC DJackson .. ---*** 05/19/15 I NRR/JLD/PMB/PM ---*-------NAME MShams BHarris NDiF rancesco -*----DATE 05/27115 05120/15 05/27/15 l'rotecting l>eople and the r:uvirou1ncnt Near-term Task Force Recommendation 2.1 Seismic Hazard Evaluation Pacific Gas & Electric Company Public Meeting

\-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent References and Logistics

• Licensee Presentation Slides -ML 15105A528
• NRC Presentation Slides -ML 15XXXX
• Public Meeting Agenda -ML 15XXX
• Licensee Hazard Report -ML 15070A607 and ML 15070A608
• Meeting Feedback Form (request from njd2@nrc.gov)
• Webcast Archive at http://video.nrc.gov
• Meeting Summary to be issued within 30-day 2

\-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent Meeting Purposes

• Gather additional information based on early identification of areas where additional technical information will support the staff's review
• Gain a better understanding of how the licensee conducted their evaluation 3

\-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent Outline

• Background of NRC Near-term Task Force Recommendation 2.1 (NTTF R2.1)
• Current NRC approach to seismic hazard characterization
• Hazard characterization for NTTF R2.1
• Potential outcomes
• Focus questions for NRC review
• Timeline 4 U.S.NRC J 1*srrm .. ..-.n:s SlU.t:AR RF.<a:O.ATOR\" Proleclitig People and the Enviroti>>umt NTTF Report and Recommendations Recommendation 2 The Task Force recommends that the NRC require licensees to reevaluate and upgrade as necessary the design-basis seismic and flooding protection of SS Cs for each operating reactor. The Task Force recommends that the Commi:,:.ion direct the actions to ew,ure aclequate protec:ion fro1r natural phenvnena. con:,i:,tent w1tl1 t*1e curre'lt :.tate of and analyt"cal met*wds. These should be cmdertaken to prevent fuel darnage and to en:,ure con:a1nrnent and :.pent fuel pool integrity: 2.1 Order licensees to reevaluate the seismic and flooding hazards at their sites against current NRG requirements and guidance, and if necessary, update the design basis and SSCs important to safety to protect against the updated hazards. 2.2 Initiate rulemaking to require licensees to confirm seismic hazards and flooding hazards every 10 years and address any new and significant information. If necessary, update the design basis for SSCs important to safety to protect against the updated hazards. 2.3 Order licensees to perform seismic and flood protection walkdowns to identify and address plant-specific vulnerabilities and verify the adequacy of monitoring and maintenance for protection features such as watertight barriers and seals in the interim period until longer term actions are completed to update the design basis for external events. RECOMMENDATIONS FOR ENHANCING REACTOR SAFETY INmE215TCENTU RY 5

\-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent N RC 50.54{f) activities to address NTTF Seismic Recommendations UMITED STATES NUCLEAR RFGULATORY COMMISSION ..:." _ '-t'ns..ees .a11d H*:..1ct:r"$ llf Pt:t*r* Is 1r ;..;. ..... cere1*ed f'fa:..,1JrrfGto-., ac roP. PL;r-ISUO.NI f(; lll_L 10 :.:* 1Hf::. L.:-:;(.>} (J' .f*t !.If i?AJ .1.'l)l\IS 5.i1:4' NG R[f:C"IM,.tft-.DA TIOt\.S; 1 l 3 Al'.(i 9 '* ()F T>--E '-F.Aq.r::ll*.1 RE"JlE".'Y ci: FRG-V THf::. [)AHCHI .. CC [;E"-1 T ... s *!So tr.m;;i '"" ""1r-.. r,( 1(; 1

• c. at the E:ns-r;;i :..:r of r<:;54 .n 3m¥idltll
• 3!"'*::J 1*+ t.. S a1i:ir:f :,-*::;.:>1'1n-::i.:i.1;:w;* **Tire 10 c:f t'le r:.' f;*1:'.J* ... 11( CTR. PJtC 5C P ** ... ;.:f1J*.*<;11Jn5 '- r;r 0'1 ..-(' t.:-: r.-::--... tn f;JX..,,. thf:' *"e1:1on rec.crrTl(""'r:at10'1\ *er :he t.Jear. r 9'"1l t as.1o .. f\ I If' :* re*, <l?w .,),.;:;. . Jr tl'\P F 1..kudun:.l Oa1 u;t11 ".*::luat ':tc ".'J T"it! ,.,,11 t!n;ihlr. :hr. w-r.!hAr rrv r:ur.lr.ear .... .;::<"-*,*::> ... ' '0$.,Y;n;o; tr. T10d1f ro susc-?rall!ld *Jf *evo .. ... or (Ci"[*"'<IM :GOL.1 *::ic>R Pa"! In NTTF 7 :t:;; J 't"\l.,.dlll!J -:.e1:s*111;. <11rtLJ 'l;,:.it.: ".g 1eev.Jh.J.,l:ut*, -'f*IJ dl'f"! y ... ... n1711 r*1 ll'I0*1SJ'es. :.t t:. y 1nf;-.r-n.)!1on .. 3 t:fll.! *l .lrl! n:t ..::r :)": Pt!'11ls 10 Pa1T s.:J 0S:t'!l:O:.I .. 9 ;>:Tlmt .;""t:S\"'" 1{) C*R Pr. 5C b nr , .. ,. .. .,n r{"*: .. ar.::;*rienl iii 1.,t:: 0<t' n * .t:;le'9t -.;<:'\\'f:* .. "!inijl 'flll11 l'IC r.I ., 11. 201 ,
• C*<!>at T -1Clo.u ... a,..e 3nd t-.e-..., RC 1&.'"*to I\ TTf C *e.:t 1 P l.lf*le>Z :!t -'::tf 1 t.asi.:ec t.. Tfr ..,,.. ""-; .:uitJ ur J.r!d :s.,d rf ""ir.**c)' should n<<L"-e .Jdd1I ::*,a i1 .. ,)11 Tlioff?I*; ;t ::-' *'1 *t 'lr. .:a.Ji:-t-:: J., ,. l2 2*: !;[ ;::'* 0 0 *CCq'.'l :..i.genr ,-\\o1c1e On.-.,, ... Ac:r.,..$'\ 01n:j No Ml ;1 OC<°.$in:-1 ::OJ.U :uound :n@ **ri*dnpt .. cc:nc,.=*" ,.. "i'dl nt rirfnn!'l.t' .., 1.t10."'1e***, l.Jlt'vt't'lt ....... , i11: 1Ja:1::i1' C.*1:J *. ., f:;* *h t ,,.. .. .;a'r.1'1 f . .r.:;t r:.n I!""! <1nrt :tit! p101*'! :..:>pao1I !n=s. rtie N f a'".: rre 1-: ii., :..: ful\ .. :s 'o <.;c;i:_r ,,., mt-iU 1 r'"1e "P.C *t-(ft ::{1ne "l1r:1i pl.:t"*t and <;* a-:u .... '3*ct '\Cl .a .. lr'!'T11., .. nt 'i' tn f1ulil i; *ri d11CI 50.54(f) Request for Information Letter issued March 12, 2012 * *
• Enclosure 1 (or R2.1): Seismic hazard and risk reevaluation Enclosure 3 (or R2.3)
• Seismic Walkdowns Other enclosures addressed flooding and emergency response 6

\-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent Tiered-approach to Seismic Activities NTTF 2.3 -Seismic Walkdowns -COMPLETED reviews June 2014 licensees identify and address degraded, nonconforming, or unanalyzed conditions relative to a plant's current licensing and design bases. // NTTF 2.1-Hazard Reevaluations: SUBMITTED CEUS:3/2014; WUS:3/2015 Licensees reevaluate hazard based on present day guidance/methods used to define the design basis for new \-..reactors. \ NTTF 2.1-Interim Evaluation: COMPLETED CEUS: 4/2014; WUS: 4/2015 --, If the design basis does not bound reevaluated hazard: Licensees evaluated the need for interim evaluations using new seismic sources and ground motion with old hazard while the longer-term risk evaluation is '* \ __ perjormed. / ---( \ NTTF 2.1-Interim Expedited Approach {ESEP) CEUS: 12/31/2014; WUS: 1/16 If the design basis does not bound reevaluated hazard: Licensees perform interim evaluation to demonstrate key pieces of equipment for core cooling at a higher hazard using installed FLEX equipment .. up to 2 x SSE. Evaluate need for modifications while longer-term risk evaluation is performed. 1 / NTTF 2.1-Seismic Risk Evaluations: June 2017-2020 -J. If the design basis does not bound reevaluated hazard: Licensees determine perform a seismic risk evaluation. Regulatory Actions NRC staff determines whether additional regulatory actions are necessary to provide additional protection against the updated hazards. 7 \-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent Probabi I istic Approach

• Previous studies such as 2011 Shoreline Fault Report and 2014 Coastal Commission Report were deterministic -Few selected scenario earthquakes -Limited treatment of uncertainty
• NTTF Recommendation 2.1 calls for seismic hazard reevaluations at each nuclear power plant using current NRC regulations
• Current NRC regulations and guidance specify a probabilistic approach for developing design ground motions
• Probabilistic ground motion hazards are characterized by a Ground Motion Response Spectrum or GMRS 8

\-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent Development of Seismic Hazard for R2.1 Reeva I uations

• Licensees perform probabilistic seismic hazard analyses following NRC guidance (Regulatory Guide 1.208) i * -* *** 1. I
• CEUS licensees (96 units/59 sites) ! =** ......... . .,, ... , .. . . '.' , . -Previously approved SSHAC Level 3 Models 1* --*** .. =***** i ...... . -Plant-specific site analyses 1. I
• WUS licensees (6 units/3 sites) . .,:*: ... .. * -Regional source and ground motion models developed by each Licensee using SSHAC Level 3 Studies -Plant-specific site analyses 9

\ -* U.S.NRC Screening Approach for R2.1 Reevaluations

• Screening approach specified in Industry Screening, Prioritization, and Implementation Details (SPID) Guidance
• SPID provides detailed guidance for -Development of GMRS -Seismic Risk Evaluations & Limited Scope Evaluations (high frequency, SFP)
• Plants with GMRS >SSE "Screen In" for -Interim Evaluations (and actions, as needed) -Expedited Interim Evaluations (and actions, as needed) -Seismic Risk Evaluations 10

\-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent Outcome 1 0.1 l lO frequency (Hz) Outcome 2 c 0 --'i"I. (i) O.l ) **:-frequency (Hz) lOC lOC Potential Outcomes for R2.1 Reevaluations No Further Analysis 20 .--------------. Outcome 3 §1.5 c .g -IU -"'* ..... (]) )IJ 0 \ \ I/) ""----00. _____ ___. 0.1 1 -o 1oc frequency (Hz) Industry Testing Program for High Frequency Sensitive components 11 NRC Review of SSHAC -. .. m, ... ,,. ... ..... ro._., Studies for WUS Sites

• Did SSHAC process follow NRC guidance?
• How effective was the peer review panel?
• Have all applicable data been considered?
• Were data uncertainties identified and considered?
• Was an appropriate range of applicable models considered?
• How were models selected and weighted in the analysis?
• How were models assembled into the PSHA? 12

\-* U.S.NRC NRC Review of Source Mode Is for WUS Sites

• How were seismic sources identified? -Geologic mapping -Geophysical observations -Earthquake catalog
• How were seismic sources characterized? -Geometry (location, length, dip) -Range of magnitudes -Faulting style (normal, reverse, strike-slip) -Slip rate and recurrence models -Complex rupture scenarios 13

\-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent NRC Review of Ground Motion Models and Site Response for WUS Sites

• Do final ground motion models capture a reasonable range of alternative models?
• How were sources of uncertainty captured in model development?
• How were ground motion models adjusted for local site geology?
• Does site response analysis cover a reasonable range of alternative soil/rock properties?
• How was uncertainty in site response analysis incorporated into final probabilistic hazard curves? 14

\-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent Hazard Development Expedited Interim Evaluations Risk Evaluations Higher Priority Lower Priority Hazard Analyses Expedited Interim Evaluations 2012 I I Schedule for Seismic Hazard and Risk Evaluations 2013 2014 2015 2016 2017 2018 2019 2020 CEUS '\

• wus '1
• All plants r CEUS I mods
• I 1 wus mods Only plants I with new
• I Group 1 I I Risk Evaluations '1 Staff acknowledgement to use GMRS for risk evaluation seismic hazard exceeding design basis Group 2 Group 3 (as needed) e Staff Assessment or response -15 Forthcoming Seismic Protecli**g People and the Enviromnent Screening Letter
• Issuance of letter for WUS sites in 2 weeks
• Diablo Canyon has screened-in for further risk evaluations and is a review priority
• No immediate safety issues identified
• Information supports safety assurance allowing additional time to complete the seismic risk evaluation 16

\-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent List of Acronyms

• CEUS -Central and Eastern United States
• GMRS-Ground Motion Response Spectrum
• NRC-U.S. Nuclear Regulatory Commission
• NPP -Nuclear Power Plant
• NTTF -Near-Term Task Force
• SFP -Spent Fuel Pool
• SMA-Seismic Margins Analysis
• SPID -Screening, Prioritization, and Implementation Details SPID
• SPRA-Seismic Probabilistic Risk Assessment
• SSC-Structures, Systems and Components
• SSHAC-Senior Seismic Hazard Analysis Committee
• SSE -Safe Shutdown Earthquake
• SPID -Screening, Prioritization, and Implementation Details
• WUS -Western United States 17

\-* U.S.NRC Break for NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent Staff Alignment

• 15 -20 minute planned break for NRC staff alignment to support meeting wrap-up
• Meeting to resume at 4:00pm (Eastern) or 1 :OOpm (Western) 18 Opportunity for Public Protecli**g People and the Enviromnent Questions or Comments
• Additional Questions? Please ask us at: JLD_PublicResource@nrc.gov 19

\-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent Backup Slides 20 Additional WUS Protecli**g People and the Enviromnent Seismic Hazard Reports Public SSHAC Reports

• Diablo Canyon http://www.pge.com/en/safety/systemworks/dcpp/sshac/index.page 21

\ -* u.S.NRC Potential Alternative s I ides 22 \-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent Guidance Documents

• Two main guidance documents proposed by industry and endorsed by the N RC
• Screening, Prioritization, and Implementation Details (SPID) -Submitted by EPRI on November 2012 -Endorsed by NRC on February 15, 2013 -EPRl-1025287 (ML12333A170)
• Seismic Evaluation Guidance: Augmented Approach (aka Expedited Approach) -Submitted by EPRI on April 9, 2013 -Endorsed by NRC on May 7, 2013 -EPRl-3002000704 (ML 13102A 142) 23

\-* U.S.NRC J I *srn:1> *TAn:s SI'( :I.UR RF.<;\'l.AHlR\" ( Protecli**g People and the Enviromnent Seismic 2.1 Process Ensures Clarity, Consistency, and Informed Regulatory Decisions PHASE 1 INFORMATION GATHERING STAGE 1 Interact with Industry on Hazard and Risk Evaluation Guidance CELIS Licensees submit Site Response (9/2013 & 3/2014) Screened-in plants complete Expedited Approach Interim (CEUS:12/31 /2014;WUS:1 /2016) and Risk Evaluation (Group 1 : 2017) NRC reviews Risk Evaluation * ,----------------PHASE 2 DECISION-MAKING NRG makes Regulatory Decisions as Needed *Safety Enhancements

• Backfit Analysis
• Modify Plant License ----------------24 Hill, Brittain From:Hill, Brittain Sent:8 Jun 2015 07:12:15 -0400 To:Kock, Andrca;Munson, Clifford Cc:Jackson, Diane;Ake, Jon

Subject:

RE: FYI: News on Diablo I checked the USGS California Seafloor Mapping Project site http://walrus.wr.usgs.gov/mapping/csmp/index.html, and there are no new (i.e., after Sept 2014) data published for the Diablo area. Surveys for this area are "in progress" The high-res data referred to in the news article are the results of previous offshore mapping, which is in the Sept 2014 PG&E Cal Coastal Commission report (on Shoreline Fault). The offshore data were considered in the SSHAC for Diablo, which includes low likelihoods for earthquakes from connected offshore faults. From: Kock, Andrea Sent: Friday, June 05, 2015 5:48 PM To: Munson, Clifford; Hill, Brittain Cc: Jackson, Diane; Ake, Jon

Subject:

FYI: News on Diablo Was this included in Diablo's recent submittal? USGS Publishes Super-High Resolution Seafloor Maps Near Diablo Canyon Plant. The Point Reyes (CA) Light (6/5, Kimmey) reports that the United States Geological Survey has published "extremely high-resolution maps of the seafloors offshore of Tamales Point, Drakes Bay and San Francisco Bay" as part of a "multi-million dollar, decade-long partnership with other agencies to pin down baseline conditions of the seafloor." According to USGS research geologist Samuel Johnson, the maps "provide a very high-resolution starting point from which you can monitor change." Among other discoveries, Mr. Johnson "said the project has found that offshore faults near Diablo Canyon Nuclear Power Plant, in San Luis Obispo, previously thought to be separated by a gap, are in fact connected." Andrea Kock, Deputy Director Division of Site Safety and Environmental Analysis Office of New Reactors United States Nuclear Regulatory Commission Ph. 301-415-2368 UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 The Power Reactor Licensees on the Enclosed List May 13, 2015

SUBJECT:

SCREENING AND PRIORITIZATION RESULTS FOR THE WESTERN UNITED STATES SITES REGARDING INFORMATION PURSUANT TO TITLE 10 OF THE CODE OF FEDERAL REGULATIONS 50.54(f) REGARDING SEISMIC HAZARD RE-EVALUATIONS FOR RECOMMENDATION 2.1 OF THE TERM TASK FORCE REVIEW OF INSIGHTS FROM THE FUKUSHIMA ICHI ACCIDENT The purpose of this letter is to inform Western United States (WUS) licensees of the results of U.S. Nuclear Regulatory Commission's (NRC's) seismic hazard screening and prioritization for plants to conduct seismic risk evaluations. The NRG staff has reviewed licensee interim evaluations which provide a safety basis supporting continued plant operations. This letter also discusses staff review plans including targets for acceptance of the seismic hazard by the end of 2015 and completion of the staff assessment in 12 to 18 months. BACKGROUND On March 12, 2012, the NRG issued a request for information pursuant to Title 10 of the Code of Federal Regulations, Part 50 (10 CFR). Section 50.54(1) (hereafter referred to as the 50.54(1) letter) (Agencywide Documents Access and Management System (ADAMS) Accession No. ML 12053A340). The purpose of that request was to gather information concerning, in part, the seismic hazards at operating reactor sites and to enable the NRC staff to determine whether licenses should be modified, suspended, or revoked. The "Required Response" section of Enclosure 1 indicated that licensees and construction permit holders should provide a Seismic Hazard Evaluation and Screening report within 3 years from the date of the letter for WUS plants (i.e., Columbia Generating Station (Columbia), Diablo Canyon Power Plant (Diablo Canyon), and Palo Verde Nuclear Generating Station (Palo Verde)). Further, the 50.54(f) letter stated that NAC would provide the results of the screening and prioritization indicating deadlines for individual plants to complete seismic risk evaluations to assess the total plant response to the re-evaluated seismic hazard. Additionally, by letter1 dated February 20, 2014, the NRC provided supplemental information on the content of the seismic re-evaluated hazard submittals including guidance on reportability and operability. The purpose of this letter is to inform WUS licensees of the NAC's screening and prioritization and to allow licensees to appropriately plan the completion of further seismic risk evaluations described in Enclosure 1 of the 50.54(f) letter. To respond to the 50.54(f) letter, all addressees committed to follow the Electric Power Research Institute (EPRI) Report, "Seismic Evaluation Guidance: Screening, Prioritization and Implementation Details (SPID) for the Resolution of Fukushima Near-Term Task Force 'The February 20. 2014, supplemental information letter is available in ADAMS under Accession No. ML 14030A046. Recommendation 2.1: Seismic,"2 as supplemented, by the EPRI Report, "Seismic Evaluation Guidance: Augmented Approach for the Resolution of Fukushima Near-Term Task Force (NTTF) Recommendation 2.1: Seismic"3 (this approach is known as the Expedited Approach). The NRC held multiple public meetings and teleconferences with industry and the public leading to the development of the guidance documents to review the re-evaluated seismic hazards. The WUS licensees submitted seismic hazard and screening reports (SHSRs) by letters dated on or before March 12, 2015 (references are provided in Enclosure 3 of this letter). The SHSRs included interim evaluations that the staff has reviewed as part of this letter. The NRC staff conducted the screening and prioritization review of the submittals by assessing each licensee's screening evaluation and hazard analyses utilizing the endorsed SPID guidance. INTERIM EVALUATIONS4 The 50.54(f) letter requested that licensees provide "interim evaluations and actions taken or planned to address the higher seismic hazard relative to the design-basis, as appropriate, prior to completion of the risk evaluation." For those plants where the re-evaluated seismic hazard exceeds the seismic design-basis, licensees stated they will provide interim evaluations to demonstrate that the plant can cope with the higher re-evaluated seismic hazard while the longer-term seismic risk evaluations are ongoing. In support of the requested interim evaluations for licensees, WUS plants provided information related to seismic margin evaluations or insights from Individual Plant Examination of External Events (IPEEE) evaluations including estimated seismic risk. Additionally, the submittals discussed completing plant seismic walkdowns as part of NTTF Recommendation 2.3 in order to verify that the current plant configuration is consistent with the licensing basis. The NRC staff review of WUS reports found that licensees have demonstrated seismic margins supportive of continued plant operation while additional risk evaluations are conducted. The interim evaluation provided in March 2015 is a first step in assessing the plant's capacity to withstand the re-evaluated hazard. In the near-term, by January 2016, licensees will complete an "Expedited Approach" to evaluate and identify reinforcements, if necessary, for certain equipment to ensure a safe shutdown pathway can withstand seismic ground motion that exceeds the safe shutdown earthquake (SSE). For Diablo Canyon and Palo Verde sites, the licensees stated that the Expedited Approach would not provide additional safety benefit for their plants because existing anaylses already demonstrate the ability to withstand the higher seismic ground motion. The NRC staff is continuing to assess the information provided by the licensees to determine if it meets the intent of the Expedited Approach review and will respond under a separate letter. 2 The SPID guidance document is found.in ADAMS under Accession No. ML 12333A 170. The staff endorsement letter for the SPID guidance is found in ADAMS under Accession No. ML 12319A07 4. 3 The Expedited Approach guidance document is found in ADAMS under Accession No. ML13102A142. 4 Enclosure 1 of this letter provides a Glossary of Seismic Evaluations, explaining each of the evaluations that are part of the overall seismic reevaluation. SCREENING PROCESS As described in the 50.54(f) letter and the SPID guidance, the seismic hazard re-evaluations were to be conducted using current analysis methods and guidance. The licensees' responses to the 50.54(f) letter provided seismic hazard re-evaluation results, which were the focus of the NRC staff's initial screening and prioritization review. Although the SSE is commonly referred to as a single number. this number represents a distribution of ground motions that occur over a range of spectral frequencies. This results in a curve of ground acceleration over frequency. The ability of the equipment and structures in the plant to withstand the effects of ground motions is frequency specific. For the purposes of the licensees' analyses and NRC staff's review, the SPID guidance identifies three frequency ranges that are of particular interest: 1-1 O Hertz (Hz), a low frequency range of <2.5 Hz, and a high frequency range of >10 Hz. The different ranges have been identified due to the different types of structures and equipment that may be impacted by ground motions in that range. For example, large components generally are not affected significantly by high frequencies (i.e.,> 10 Hz). The frequency range 1-10 Hz is the focus for this portion of the risk evaluation. as this range has the greatest potential effect on the performance of equipment and structures important to safety. For other frequency ranges, discussed below, limited-scope evaluations will be conducted, when appropriate. In accordance with the SPID and Expedited Approach guidance, the re-evaluated seismic hazard determines if additional seismic risk evaluations are warranted for a plant (i.e., the plant screens in for further evaluation). Specifically, the re-evaluated ground motion response spectra (GMRS) in the 1-10 Hz frequency range is compared to the existing SSE:

• If the re-evaluated GMRS. in the 1-10 Hz range, is less than the plant's existing SSE, then the plant screens out of conducting further seismic risk evaluations.
• If the GMRS, in the 1-10 Hz range, is greater than the existing SSE. then the plant will complete the Expedited Approach (including the Interim Evaluation). Most plants that meet this criterion also screen in to conduct a seismic risk evaluation and have committed to conduct high frequency and spent fuel pool evaluations. In addition. if the GMRS meets the low hazard threshold, which is described in the SPID, and only exceeds the SSE below 2.5 Hz, the licensee will perform a limited evaluation of equipment potentially susceptible to low frequency motions. Similarly. if the GMRS exceeds the SSE only above 10 Hz, then the licensee will perform an evaluation of the equipment or structures susceptible to that specific range of ground motion. Enclosure 2 provides the staff's determination of priority tor plants that screen-in to conduct a seismic risk evaluation, and identification of plants to complete limited-scope evaluations (i.e., spent fuel pool, high frequency, or low frequency).

. 4. CONDITIONAL SCREENING As discussed in public meetings5, the staff anticipated the possibility of not being able to complete the determination for conducting a seismic risk evaluation for some plants in the 30 to 60 day review period under certain circumstances. For example, if a licensee provided a unique submittal or deviated from the SPID guidance, additional time for the review might be needed. In general, WUS submittals contain extensive site specific information including site specific source models and ground-motion models which could affect the final screening decisions. Accordingly, during the NRC screening and prioritization process, the staff identified that for Palo Verde additional time and interactions will be required to better understand the seismic hazard for the plant. As such, the staff determined that Palo Verde "conditionally screens-in" for the purposes of prioritizing and conducting additional evaluations. After interactions have occurred, the staff will make a final screening and prioritization determination and provide a letter to the licensee. If the plant remains screened-in, the final screening letter will affirm the plant priority for further evaluations and establish schedule for an Expedited Approach, if necessary. If the plant screens out, the final screening letter also will determine if Palo Verde needs to complete limited-scope evaluations (i.e .. spent fuel pool, high frequency, or low frequency). PLANT PRIORITIZATION The NRC grouped the "screened-in" plants into three groups6, which (i) reflects the relative priority for conducting a seismic risk evaluation that compares each plant's current capabilities to the re-evaluated seismic hazard, and (ii) accounts for the appropriate allocation of limited staff and available expertise for reviewing and conducting seismic risk evaluations. During the prioritization review, the staff considered each licensee's re-evaluated hazard submittals, plant specific seismic and risk insights. The WUS plants are included in the same groups as CEUS plants for completion of seismic risk evaluations. To prioritize the plants for completing seismic risk evaluations, staff examined certain key parameters such as ( 1) the maximum ratio of the new re-evaluated hazard (G MRS) to the SSE in the 1*1 O Hz range; (2) the maximum ground motion in the 1-1 0 Hz range; and (3) insights from previous seismic risk evaluations. As such, Group 1 plants are generally those that have the highest re-evaluated hazard relative to the original plant seismic design-basis (GMRS to SSE), as well as ground motions in the 1-10 Hz range that are generally higher in absolute magnitude. Based on these criteria. Columbia and Diablo Canyon are prioritized as Group 1 plants. Group 1 plants, including Columbia and Diablo Canyon are expected to conduct a seismic risk evaluation and submit it by June 30, 2017. Although, WUS have a shorter timeframe to develop a seismic risk evaluation relative to CEUS plants, WUS sites have the benefit of updating existing seismic probabilistic risk assessments (SPRAs) to meet current guidance. Group 3 plants have GMRS to SSE ratios that are greater than 1, but the amount of exceedance in the 1-10 Hz range is relatively small, and the maximum ground motion in the 5 Discussion as part of public meetings dated December 4, 2014, February 11, 2015, and March 30, 2015 (ADAMS Accession Nos. ML 14342A901, ML 15104A065 and ML 15111 A031, respectively}. 6 Central and Eastern licensees seismic hazard screening and priority reviews were completed in 2014. 1*10 Hz range is also not high. As described above, Palo Verde has conditionally screened in; based on current information Palo Verde has been assigned to prioritization Group 3. Given the limited level of exceedance of the Group 3 plants including Palo Verde, staff is evaluating the need for licensees to conduct a seismic risk evaluation in order for the staff to complete its regulatory decision making. After further review, the staff will decide which Group 3 plants need to complete a seismic risk evaluation to inform NRC regulatory decision making. Risk evaluations for Group 3 plants are due by December 31, 2020. NEXT STEPS Based on the staff's screening review. the licensee for Columbia should finalize and submit an Expedited Approach report no later than January 31, 2016. The NRC staff is continuing to review the licensee-provided information for Diablo Canyon and Palo Verde related to the Expedited Approach. In accordance with the endorsed guidance, the staff acknowledges that the January 2016 Expedited Approach submittal will focus on plant equipment (i.e. safe shutdown pathway7) evaluations and modifications, as necessary, prior to submitting the plant seismic risk evaluations. The content of limited-scope evaluations or confirmations and their associated schedule milestones remain under development with NRC staff and stakeholders. The NRC staff has conducted a number of public meetings on the implementation details of these evaluations, including the development of alternatives approaches for conducting these evaluations. The staff expects that implementing guidance should be established by summer 2015 and fall 2015 for high frequency and spent fuel pool evaluations, respectively. It is expected that WUS licensees can complete these evaluations in parallel with completion of SPRAs for Group 1 plants by June 2017. This letter transmits the NRC staff's results of the seismic hazard submittals for the purposes of screening and prioritizing the plants. It does not convey the staff's final determination regarding the adequacy of any plant's calculated hazard. As such, the NRC staff will continue its review of the submitted seismic hazard re-evaluations, and may request additional plant-specific information through the summer of 2015. The staff has placed a high priority on this review for the early identification of issues that might adversely affect each licensee's seismic risk evaluations. Interactions with licensees will occur as soon as practical, including NRC staff plans to acknowledge whether seismic hazard curves are suitable for use in SPRA development by the end of 2015. The NRC staff plans to issue a staff assessment on the re-evaluated seismic hazard once each review is completed in approximately 12 to 18 months. 7 Section 3 of the Expedited Approach guidance (ADAMS Accession No. ML 13102A142), provides a process to identify a single seismically robust success path using a subset of installed plant equipment, FLEX equipment and connection points. If you have any questions regarding this letter, please contact Nicholas Difrancesco at 301-415-1115 or via email at Nicholas.Difrancesco@nrc.gov. Sincerely,

Enclosures:

1. Glossary of Evaluations 2. Screening and Prioritization Results 3. List of Licensees' March 2015 Re-evaluated Seismic Hazard Submittals 4. List of Licensees cc w/encls: Listserv Glossary of Evaluations Associated with Near-Term Task Force Recommendation 2.1 Seismic Hazard Re-evaluations Interim Evaluation or Actions -An immediate licensee and NRC review of the re-evaluated hazard to determine whether actions are needed to assure plant safety while further evaluations are ongoing. The staff has completed its review and concluded that, based on the licensees' interim evaluations and actions, Western United States (WUS) plants are safe for continued operations. Interim evaluations and actions are provided in Section 5.0, "Interim Actions," of the licensee submittals. Expedited Approach -A near-term licensee evaluation to be completed by January 31, 2016. for WUS plants whose re-evaluated hazard exceeds the current design-basis for the safe shutdown earthquake (SSE) hazard level. The evaluation looks at the systems and components that can be used to safely shut down a plant under the conditions of a station blackout (i.e., no alternating current power is available) and loss of ultimate heat sink. The expedited approach will either confirm that a plant has sufficient margin to continue with a longer-term evaluation without any modifications, or confirm the need to enhance the seismic capacity to assure they can withstand seismic ground motion that exceeds the safe shutdown earthquake. The Expedited Approach guidance document is found in the Agencywide Documents Access and Management System under Accession No. ML 13102A142. Seismic Risk Evaluation -Longer-term seismic risk evaluation provides the most comprehensive information to make regulatory decisions, such as whether to amend a plant's design or licensing basis or make additional safety enhancements. These evaluations provide information to make risk-informed decisions. The staff will use this information in conjunction with the existing regulatory tools, such as backfit analyses, to decide on further regulatory actions. The longer-term seismic risk evaluations could be either a Seismic Margins Assessment or a Seismic Probabilistic Risk Assessment, depending on the magnitude of the exceedance. Limited-Scope Evaluations -These include i) Spent Fuel Pool Evaluation, ii) High Frequency Evaluation, and iii) Low Frequency Evaluation. Respectively, these evaluations are focused on the following: i) spent fuel pool components and systems capable of draining water inventory to the level of the spent fuel, ii) a review of components susceptible to high frequency accelerations (e.g. electrical relays). and iii) a review of components susceptible to low frequency accelerations (e.g. water storage tanks). Enclosure 1 Near-Term Task Force Review of Insights from the Fukushima Dai-lchi Accident Seismic Risk Evaluations Screening and Prioritization Results for Western United States <WUS) Reactor Sites Seismic Risk Limited-scope Evaluations Screening Expedited Evaluation High Low Spent Fuel Plant Name Result Approach (Prioritization Frequency Frequency Pool Evaluation Group) Evaluation Evaluation Evaluation Columbia Generating Station In x 1 x x Diablo Canyon Power Plant, Unit In x* 1 x x Nos. 1and2 Palo Verde Nuclear Generating Conditional x* 3 x Station, Units 1, 2, and 3 in x

• NRC staff is evaluating whether information provided meets the intent of the Expedited Approach. The staff's conclusions will be provided in a separate letter. Enclosure 2 March 2015 Re-evaluated Seismic Hazard and Screening Reports for Western United States Reactor Sites Licensee Facility Date of letter (ADAMS Accession Nos.) Columbia Generating Station March 12, 2015(Ml15078A243) Diablo Canyon Power Plant, Unit Nos. 1 and 2 March 11, 2015(Ml15071A046) Palo Verde Nuclear Generating Station, Units March 10, 2015, (ML15076A073) and 1, 2, and 3 April 10, 2015(ML15105A076) Enclosure 3 LIST OF APPLICABLE POWER REACTOR LICENSEES Columbia Generating Station Energy Northwest Docket No. 50-397 License No. NPF-21 Mr. Mark E. Reddemann Chief Executive Officer Energy Northwest MD 1023 76 North Power Plant Loop P.O. Box 968 Richland, WA 99352 Diablo Canyon Power Plant Unit Nos. 1 and 2 Pacific Gas & Electric Company Docket Nos. 50-275 and 50-323 License Nos. DPR-80 and DPR-82 Mr. Edward D. Halpin Senior Vice President and Chief Nuclear Officer Pacific Gas and Electric Company P.O. Box 56 Mail Code 104/6 Avila Beach, CA 93424 Palo Verde Nuclear Generating Station. Units 1. 2. and 3 Arizona Public Service Company Docket Nos. STN 50-528, STN 50-529. and STN 50-530 License Nos. NPF-41. NPF-51 and NPF-74 Mr. Randall K. Edington Executive Vice President Nuctear/CNO Arizona Public Service Company P.O. Box 52034, MS 7602 Phoenix. AZ 85072-2034 Enclosure 4

ML 151138344 *via email . QfFICE ____ NRR/JLD/LA NRR/JLOIHMB/BC NRO/DSEA/RGS2/BC ; NRR/DORUD . .NDiFrancesc9 SLent *-____ --r-5Jackson---*--; LLu-nd _-__ DATE : 04/22/15 04/24/15 04/23/15 05105/15 05108115 .OFFICE-* NROJDSEA/D ---. OGC NRRtJLDID ==--__ ..... ----* NAME SFlanders __ fo.1_ (J\j_hle for) 05104115 05/07/15 05/13115 DiFranccsco, Nicholas From:DiFrancesco, Nicholas Sent:8 Apr2015 16:30:17 +0000 To:Munson, Clifford;Dcvlin-Gill, Stcphanic;Akc, Jon;Sticvc, Alice Cc:Heeszel, David;Rivera-Lugo, Richard

Subject:

Additional Palo Verde Documents Folks, I have place the additional Palo Verde documents in shared location. Please let me know if you have access issues. Documents are about 100 mb. The licensee is still compiling the PPRP comments and TIT resolution. S:\Palo Verde R2.1 Seismic Information\ Thanks, Nick Senior Project Manager -Seismic Reevaluation Activities U.S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Japan Lesson Learned Project Division n icho las.difrancesco@nre.gov I Tel: (301} 415-1115 Sent:2 Apr 20 I 5 15 :28 :25 +0000 To: 'Thomas.N. Weber@aps.com' ;Carl.stephenson@aps.com; Vega, Frankie

Subject:

APS -R2. l Seismic Licensing Call (888-817-9392 PC: 7956336) Past Seismic Public Meeting http://www.nrc.gov/reactors/operatinq/ops-experience/japan/japan*meetinq-briefinq.html Tom, 11 am eastern is open. A couple of items for discussion, coordination, and planning today. Thanks, Nick

• Supplemental Letter Planning
• Staff Reference for Additional References
• SSHAC PPRP and TIT Comments and their resolution
• Example
• Example from CEUS SSHAC Appendix I -ssc.com/Report/ Appendixl.html 11) PPRP Comment Response Table
• HID Attachments
• Attachment A: Areal Source Coordinates (electronic attachment)
• Attachment B: Fault Source Coordinates (electronic attachment)
• Attachment C: UCERF3.3 Rupture Sets (electronic attachment)
• Attachment D: ABSMOOTH Output (electronic attachment)
• Attachment E: SWUS GMC Regions for Fault Sources (electronic attachment)
• Public Meeting Tentative May 20 Agenda Outline 1. NRC a. Introduction of Meeting Agenda Structure b. General Background on 50.54(f) and 2.1 Seismic c. Technical discussion on goals and expected outcome d. Intro of seismic hazard PSHA methods and use for licensing of new plants I SSHAC 2. Licensee e. SSHAC effort f. Sources g. GMM h. Interim Actions i. Technical Issues I Discussions

3. Break [to discuss -separate staff discussion] 4. NRC j. Discussion of Interim actions and approach k. Technical wrap-up-next steps I. Public Questions From: Thomas.N.Weber@aps.com [ mailto: Thomas. N.Weber@aps.com] Sent: Wednesday, April 01, 2015 8:51 PM To: Difrancesco, Nicholas

Subject:

Supplemental Information Letter for the Palo Verde Seismic Hazard Reevaluation Report Nick, Are you available to discuss the supplemental information letter we are writing regarding the seismic reevaluation report we submitted on March 10, 2015. I was hoping to talk to you tomorrow (Thursday April 2} at 8:00 am AZ time (which is 11:00 am EDT). Or if more convenient, you can call me in my office at 623-393-5764. TN Weber ... DiFranccsco, Nicholas From:DiFrancesco, Nicholas Sent:4 Jun 2015 13:23:19 +0000 To:Munson, Clifford;Scbcr, Dogan;Jackson, Diane Cc:Seber, Dogan;Hill, Brittain;Stirewalt, Gerry

Subject:

Attached ---Columbia Missing Slides Attachments: missing pages2. pdf Fyi. -----Original Messnge-----i-;rom: Williams, Lisa L. l mai Ito: llwi 11 iams@energv-northwest.com J Sent: Thursday, June 04, 2015 9:22 AM To: Dihancesco, Nicholas

Subject:

RE: Thanks! RE: Question on Columbia Seismic Public Meeting Slides Nick, We found the missing slides. I have updated our sel of slides but now it is over the 5 MB limit for NRC email. The missing slides arc attached lo this email. Thanks. Lisa from: Difrancesco, Nicholas [Nicholas.Difrancesco@nrc.govl Sent: Wednesday, June 03, 2015 2:45 PM To: Williams, Lisa L. Subject Thanks! RE: Question on Columbia Seismic Public Meeling Slides Thanks. I'll have slaff check lhc slides. Also. NRC slides are still draft, however, they will likely be a short intro version from previously public meetings. -Nick -----Original Message-----From: Williams. Lisa L. [ mai Ito: II w illimus @energ v-north west.com l Sent: Wednesday, June 03, 2015 5:41 PM To: Difrancesco. Nicholas

Subject:

RE: Question on Columbia Seismic Public Meeting Slides Nick, l believe it is covered in the GMM section. Lisa Sent from my Verizon Wireless 4G L TE smartphonc --------Original message--------from: "Difrancesco, Nicholas" <Nicholas.Difranccsco@nrc.gov> Date: 06/03/2015 5:15 PM (GMT-05:00) To: "Williams, Lisa L."<ilwilliams@cncrgy-northwcst.com> Cc: 'Rich Rogalski' <richard@richard.rogalski.name>

Subject:

Question on Columbia Seismic Public Meeting Slides Lisa. Received a question from the staff of whether Topic #2 under the Source Characterization will be covered verbally'! Thanks, Nick Seismic Source Characterization, Focus Area 2 2. Summarize the information use to define the areal seismic source zones, including: a. Bases for zone boundaries b. Seismicity rate calculations, smoothing, and how uncertainty was captured as part of logic tree. c. Bases for Mmax distributions Pertains to these sections of the report Section 8.1.4.2 Seismic Source Zones Section 8.1.5 Structure of the SSC Model Logic Trees Section 8.3.2 Source Zone Characteristics for the SSC Model Seismic Source Zones Seismic sources defined by differences in: Seismogenic probability p[S] Maximum magnitude, Mmax Recurrence (spatial variations in rate) Future earthquake characteristics For Hanford SSC Model, two types of source zones: YFTB background zone that represents non-fault sources Given original deposition of CRB and age, provides a unique marker for any post-10 My deformation or significant faulting Accounts for sources not included as fault sources Zones B, C, and D include all types of sources; fault sources are not identified separately Summary of SSC Model Assessments Seismic Source Zones Geometry Nature of source boundaries to future ruptures: leaky Future earthquake characteristics Style of faulting Strike and dip of ruptures Seismogenic thickness Mm ax Presence or absence of fault sources Largest observed earthquakes Recurrence Uniform M earthquake catalogue Corrected for clustering and incompleteness Spatial variation in rates Criteria for Defining Source Zone Boundaries

• Tectonic environments Columbia River Basin Cascades Craton Palouse Blue Mountains Yakima Fold Belt
• Seismogenic thickness
• Presence or absence of YFB faults
• Geophysical evidence for Pasco Gravity Low
• Changes in seismicity m ** .. ._, .... EIMJ ,_, '* / " ** J 1.85 to2 / .... \ *.,_ 2 to 3 ' *,, 3 to 4 ., ****** ; / .. --', 4 to 5 / ,;'(.*.** ..... ) .... Sto 6 6to 7 >: 7 :*-: .. *; l-..' . <'..:. . .". ,**.</ / .. * -... .* "..... -.1 r '-"'"'* . ,_ Idaho c *C ,*. ,-)'if '-. o* Study Area 0 50 100 --Kilometers -Fault Sources Source Zones . ... :;

Future Earthquake Characteristics

• Style of faulting
• Strike and dip of ruptures
• Dimensions of rupture .. .. :J. G' ... Right Late1al All Events (n = 447) left laleral I Normal I I ** 11i.11i11.111.i1l1ii11 I R('lferse R19ht *St< Late111I I . 111 ' . . .. *.* .......... *.*. : . . . '*' : . . . *,* , . '. .:. . . . . . .. . . *.* .;,* . . ,,. . . . . .. ,. . . . . ........ *, ... * : . : '. Raki' l"I *7c :l c:J Source Zones -J .....
• 0 50 --t Hanford Site Boundary 100 Kilometers 1 *e .,, *Sh Source Zone Mmax 0.4"> 0.4 O . 0.3 0.2'."> O . .l 0.1 O.OS 0 Fault Source Mmax Distributions 11 I
• Aht.rnum-R<ittlesn.lke Ill ( olu111hi<1 CJ Clernan Mount<iin D FH'rltllru.rn 8 HP,Wf'll *Hom F,wa
• Rirlge *RAW
• R;at t IP\.r1.1kP
• Butte *Saddle Mount.iin o roppenish Ridge o Ur11t.inum Ridge D W;illul.-i F<1ult *Y<1kinu RidRC *Arlington 0 L.iurel f .iult El llin<1 Butte o M.iupi11 r .iult Source Zones B C D 6.85 6.95 7.05 ' ' 6.65 6.75 6.5 [0.2] 6.75 [0.5] 7.0 [0.2] 7.25 [0.09] 7.5 [0.01] YFTB Source Zone 6.5 [0.3] 6.75 [0.4] 7.0 [0.3]

Smoothing

• Nearest-neighbor analysis to assess spatial homogeneity
• Uncertainty included in logic tree *Spatial Smoothing of values using adaptive kernel ..... , 40 .. , Oregon o Seismicity .....______.! Source Zones 118 * .,.,. Idaho Study Area 0 50 100 *--=*--=---Kilometers 120W
• Source Zone Logic Tree SEISMOGENIC THICKNESS Thin [0.3) Moderate [0.4] Thick [0.3] ss =source specific SOURCE ZONE YFTB Zone B Zone C Zone D Mmax Mag X [wt SS] MagY [wt ss] Mag Z [wt ss] SPATIAL VARIATION Smoothing [wt ss] Uniform [wt SS) SEISMICITV ASSOCIATION WITH FAULT SOURCES Associated with fault sources [0.2] Not associated with fault sources [0.8]

DiFranccsco, Nicholas From:DiFrancesco, Nicholas Sent:5 May 201521:46:19 +0000 To:Lingam, Siva;Singal, Balwant;Watford, Margaret Cc:Markley, Michael;Orf, Tracy

Subject:

Awareness of Forthcoming Issuance of WUS Seismic Screening and Prioritization Letter Attachments:lnfo POP Western US Screening Letter rev6.docx Siva. Balwant, Maggie, For awareness, JLD is moving forward issuance of the WUS Seismic Screening and Prioritization letter targeted for Mav 12for Columbia, Diablo, and Palo Verde. I am planning to communicate the results to licensee management once the letter is signed. Current Letter: Open ADAMS P8 Document (Screening and Prioritization Results for the Western United States Sites Regarding Information Pursuant to Title 10 of the Code of Federal Regulations 50.54(f) Regarding Seismic Hazard Re-Evaluations for Recommendation 2. 1 of the NTTF Review) A few highlights for awareness:

• WUS Seismic Hazard Review Progress o Screening & prioritization letter -targeting issuance 5/12/15 o All 3 plants screen in tor sPRA; no immediate safety issues o Columbia & Diablo Canyon -Group 1
• sPRA due 06/30/17 (Seismic Probabilistic Risk Assessment)
• Diablo Canyon -Separate letter on ESEP; LTSP provides safety basis
• Public Meetings o Diablo Canyon (04/28/15) o Columbia (06/04/15) o Palo Verde -Group 3
• sPRA due 12/31/20
• Public Meeting 06/09/15 Please let me know if you have any questions or concerns. Thanks. Nick Senior Project Manager -Seismic Reevaluation Activities U.S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Japan Lesson Learned Project Division nicholas.difrancesco@nrc.gov I Tel: (301) 415-1115 OFFICIAL USE ONLY-SENSITIVE INTERNAL INFORMATION INFORMATION POP Western US Seismic Screening and Prioritization Status May 5, 2015 PURPOSE: Brief NRR and NRO Management on the WUS Seismic Screening and Prioritization Review Letter EXPECTED OUTCOME: Understanding of the staff's review approach, conclusions and path forward detailed in the WUS Seismic Screening and Prioritization Review Letter PROCESS: Timeline
• March 2015 -WUS sites submitted their seismic hazard reevaluation (summary) reports including proposed interim action, when applicable. SSHAC reports were also made available
• April -June 2015-The staff plans to conduct individual public meetings with licensees to discuss the reevaluated hazards submittals.
• May 2015 -The staff plans to issue the screening and prioritization results letter for the WUS sites. Screening and Prioritization Letter Content
• Screening and prioritization review letter target for issuance is Tuesday May 12
• Review approach consistent with CEUS sites; WUS sites greater complexity due to unique source characterization and ground motion models
• No immediate safety concerns identified
• NRC targeting release of GMRS curve for SPRA development late 2015 Preliminary NRC screening determinations WUS Sites Seismic Risk Interim Limited Scope ESEP Evaluation Actions Evaluations Columbia Generating Station Group 1 Yes Yes Jan 2016 (acceptable) (SFP/HF) Diablo Canyon Power Plant, Unit Group 1 Yes Yes Jan 2016 Nos. 1and2 (acceptable) (SFP/HF) Palo Verde Nuclear Generating Conditionally in Yes Yes Jan 2016 Station, Units 1, 2, and 3 Group 3 (acceptable) (SFP/HF) Plant safety and interim actions
• Diablo Canyon (DC) screens-in to perform a detailed risk evaluation as a Group 1 plant. For interim action, DC has demonstrated margin above their GMRS by comparing their design basis (Hosgri) and the LTSP earthquakes to the reevaluated GMRS.
• Columbia screens-in to perform a detailed risk evaluation as a Group 1 plant. For their interim action, the licensee referenced their IPEEE seismic PRA results along with recent updates to their models to demonstrate capacity above their GMRS.
• Palo Verde conditionally screens-in to perform a detailed risk evaluation as a Group 3 Plant due to a small exceedance of the SSE. Palo Verde will provide a supplemental letter to provide details regarding their interim action review, their seismic licensing basis and justification for not performing the ESEP review.
• NRG staff has found that WUS sites may continue to operate while additional safety assessment are conducted. OUTCOMES:
• Alignment on seismic screening letter content and preliminary results
• Awareness of plant seismic evaluations and interim actions
• Awareness of communication and review timeline Communication Plan Timeline (ADAMS ML14083A619) Date Activity (responsible organization) Sig_nifjcant Historic Actions Completed (2/20/14) Issued letter to all licensees Re: Operability, Reportability, Interim Evaluation and Actions (ML14030A046) Completed (5/9/14) Issued Central and Eastern US (CEUS) Seismic Screening Letter (ML14111A147) WUS Seismic Hazard Screening Review Completed (3/12/15) NRC Receipt of WUS Hazard Reports (JLD/licensees) Completed (3/30/15) NRC/NEI Seismic Public Meeting w/ Discussion of WUS Review Process Completed (4/15/15) Target for public meeting notice of April 28 Diablo Seismic Meeting (JLD-DiFra ncesco) Completed 4/27 /15 Public availability of NRC and licensee slides for April 28 meeting (JLD -DiFra ncesco) Completed 4/28/15 Diablo Canyon Public Meeting on 2.1 Seismic (NRR/JLD, NRO/DSEA, Licensee) Completed 4/29/15 Complete WUS screening & prioritization technical review (NRO/DSEA) 5/7/2015 Distribute WUS screening & prioritization letter to R-IV, OPA, OCA, OEDO (NRR/JLD liaison team) 5/11/2015 Notice to states, congressional, licensee issuance, and NGOs of pending issuance (RSLO, OCA, JLD) 5/12/2015 Issue WUS screening & prioritization letter licensees including review of interim evaluation and actions (NRR/JLD) Issue Press Release on prioritization review (OPA) 6/4/15 Columbia Public Meeting on Methods (NRR/JLD, NRO/DSEA, Licensee) 6/9/15 Palo Verde Public Meeting on Methods (NRR/JLD, NRO/DSEA, Licensee) 6/23/15 Diablo End of Cycle Meeting and Open House (R-IV) late Summer Columbia End of Cycle Meeting (R-IV) Continuing Staff assessment of the reevaluated seismic hazard (NRO/DSEA, NRR/JLD) Points-of-contact: TBD DiFranccsco, Nicholas From:DiFrancesco, Nicholas Sent:27 Apr 2015 17:33:54 +0000 To:'Jahangir, Nozar';Socncn, Philippe R Cc:Strickland, Jearl

Subject:

Bridgeline and Webcast Information for NRC/PG&E Public Meeting on April 28 Attachments:NRC Slides for DCPP mtg Apr 2015.pdf Folks, A few meeting logistics. NRC Slides Attached. The webcast can be watched at: http://video.nrc.gov/ For awareness, there will be a small delay between the bridgeline and the internet webcast. Bridgeline Information Licensee Lines 888-469-1602 PC: 10973 Public Meeting Lines 888-792-8503 PC: 3081295 Please let me know if you need anything additional. Thanks, Nick Senior Project Manager -Seismic Reevaluation Activities U.S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Japan Lesson Learned Project Division nicholas.difrancesco@nrc.gov I Tel: (301) 415-1115 l'rotecting f:Jeopl.e and the E11viron1nent Near-term Task Force Recommendation 2.1 Seismic Hazard Evaluation Pacific Gas & Electric Company Public Meeting References and Logistics

• Public Meeting Agenda -ML 15105A528
• NRC Presentation Slides -ML 15117 A226
• Licensee Presentation Slides -ML 15117 A069
• Licensee Hazard Report -ML 15070A607 and ML 15070A608
• Meeting Feedback Form (request from njd2@nrc.gov)
• Webcast Archive at http://video.nrc.gov
• Meeting Summary to be issued within 30-day 2

\--U.S.NRC J ,.,_.., '" ou.o;n. rnmr Pratecti>l,r: Pu>/>le and thP. F.nvirmrmeut Meeting Purposes

• Gather additional information based on early identification of areas where additional technical information will support the staff's review
• Gain a better understanding of how the licensee conducted their evaluation 3

\--U.S.NRC J ,.,_.., '" ou.o;n. rnmr Pratecti>l,r: Pu>/>le and thP. F.nvirmrmeut Outline

• Background of NRC Near-term Task Force Recommendation 2.1 (NTTF R2.1)
• Current NRC approach to seismic hazard characterization
• Hazard characterization for NTTF R2.1
• Potential outcomes
• Focus questions for NRC review
• Timeline 4

\--U.S.NRC J ,.,_.., '" ou.o;n. rnmr Pratecti>l,r: Pu>/>le and thP. F.nvirmrmeut NTTF Report and Recommendations Recommendation 2 The Task Force recommends that the NRC require licensees to reevaluate and upgrade as necessary the design-basis seismic and flooding protection of SS Cs for each operating reactor. The Force that the direct the :ollmv1ng action:, to adequate protec:ion frorr natural pheno11ena, consistent with t1e curre1t of knowledge and anatyt cal rnet'1od: .. The:,e :,hould be ,mdertaken to prevent fuel and to erw.1re con:ainrnent and spent fuel pool integrity: 2. 1 Order licensees to reevaluate the seismic and flooding hazards at their sites against current NRC requirements and guidance, and if necessary, update the design basis and SSCs important to safety to protect against the updated hazards. 2.2 Initiate rulemaking to require licensees to confirm seismic hazards and flooding hazards every 10 years and address any new and significant information. If necessary, update the design basis for SSCs important to safety to protect against the updated hazards. 2.3 Order licensees to perform seismic and flood protection walkdowns to identify and address plant-specific vulnerabilities and verify the adequacy of monitoring and maintenance for protection features such as watertight barriers and seals in the interim period until longer term actions are completed to update the design basis for external events. RECOMMENDATIONS FOR ENHANCING REACTOR SAFETY iNrnE2151CENTU RY 5 \--U.S.NRC J ,.,_.., '" ou.o;n. rnmr Pratecti>l,r: Pu>/>le and thP. F.nvirmrmeut NRC 50.54(f} activities to address NTTF Seismic Recommendations uM1rED s r.e.rts NUCL£AR RFGULATORY COMMISSION ,.:.." Reac.:o* _ d111d H*:..1ct:"r'!I: llr Pt:'t*r Is 1r ;..;. '*v1:' .. ,.. ::;141 f'fa:..,1Jirft#to-., ac RE:).Jf::.S' roP. NFOrWAllO" l"l.;r.ISU.O.NI lll_L 10 :.:* 1Hf::. L.:.:;U} u* ,q !.If i?AJ 5-4:4' NG RCCC,,n.*ff\()ATIOf\S; 1 ').) AMi 9 :;. OF Tl-oE RE'JlE'.'* CF FRGA/ lHf::. DAl-ICHI 4\:C [;Et..1 , ... .... .. r,( 1(i1 .;, at the :..:r of t<:;54 .n 3meeidita. 3!"'*'.l t.. S 1 p,.qc ;,-*:: ;.Wur :i.:u::w ;. * ** Tit e 1 Q c:f t'le r:-.' f;*1:r_,* .. 11( CTR. PJH 5C P .. ... to ;,;f1J'*"St1JnS '- r;r 0'1 f¥t tn ,;JX..,,. 'er :he t.Jear. r v-n 'ali. *."-I If' :* re*1 "l?'w .,).;::; . .at rr.p F L.kustun:J Oa1 n.:r11 ".*::luat *ac ".'J T"it! "'II t!n::ahlr. :hr. w-t:!hAr Uv r:w:lr..,r .... 'f::> .. :,;.h:r tc T10d1f ro susc-?rallJd *Jf *evo .. i.:or (-01'[* "'<l?'d . :) C>R Par: In NT TF ; J 't"\l.,.dlll!J ..:1rnJ *l:J:.or.: **.g .mLJ f.",i:rofr..rol! ai! n1711 t*/ lo<::*1SJ'@$ 1 4 :.t le1:e* t:. m1la! y 1nf:Y'Y'l.l!1on .. "Lo::.i*)i--'&i. 3 *1.lrl! n:t :)'°: pt!*1**11s .;*v.:1t* 10 P:"trt s.:J Oj:t'!l:.:.1 *'9 ;>:,Im* 't:..lCtc;; .;'"l:S\"" 1{) C*R Pr. 5C ,..'" mqu*'n-j 't:"'rmrd 1::* .. ,1 nr , ** ,. r{"*: .. c:?1l'S .lr.::;.iienl ail 1.,t; n ... n ... t.:<:'\\'lf!' .. "!in)il *rn111 i*1c rJ ., 11. 201 , . T oriclo.u ... afl.e .lnd "S1.J:'l)t"l*Jon1 ts, .. RC *&*"'("0 "'TTf (* c *e.:t 1 n.e-"* P 1.l:-,1e-z :!t 4::tf 1 I\ Tfr w J ;arid ur .lr'!d :s.,d rf "*'ie**c)' should .Jdd1I ::*,a i1 .. ,)11 Tliofr.I*; ;t ..... ,.. ::' -::nnl.:11*1e.1t *'l *t "'lr. J., ,. ll i*: ;::'* * * *CCq'.1 ""'1c1e On.-.,, .. Ac:r.,..$'\ 01n:j "lo Ml 11 *.-.oi& opr:J U'§. .. ., i1 0C(°.$1!'l:'" ::>J*lt :uound :n@ .. cc:no**=** ,.. '°"'h*r.." IP"'*' nf 1.r10."h::***1 ... ,., 1l*: y3:1::i1' C.*1:J *. & ., f:;* *h L'.::t** r ,,.. .;a'r.1*1 f . .r.::t c:.n I!"<! arpr:-i.-ct-<1nrt :tit! :..:>pao1I rt1e N r a .. c rre the= C011LJi:=nte I<: o::ncl.10(t :l'\811 8., .... :..: lh! ful\ .. :s 'o <.;c;i:_r .,., lht-iU 1 f'"1e "RC "t'(ft ;:4:1n* "l1r:1i pld.t and <;0 llfe")lng ... *te$ ;l1ct "C1 ar-lr"!Tfll""IPnt r fn f1Ulil i; *r: dllO 50.54(f) Request for Information Letter issued March 12, 2012 * *

• Enclosure 1 (or R2.1 ): Seismic hazard and risk reevaluation Enclosure 3 (or R2.3): Seismic Walkdowns Other enclosures addressed flooding and emergency response 6

\--U.S.NRC J ,.,_.., '" ou.o;n. rnmr Pratecti>l,r: Pu>/>le and thP. F.nvirmrmeut Tiered-approach to Seismic Activities NTTF 2.3 -Seismic Walkdowns -COMPLETED reviews June 2014 licensees identify and address degraded, nonconforming, or unanalyzed conditions relative to a plant's current licensing and design bases. l. NTTF 2.1-Hazard Reevaluations: SUBMITTED CEUS:3/2014; WUS:3/2015 licensees reevaluate hazard based on present day guidance/methods used to define the design basis for new reactors. _.,/ NTTF 2.1-Interim Evaluation: COMPLETED CEUS: 4/2014; WUS: 4/2015 -\j If the design basis does not bound reevaluated hazard: licensees evaluated the need for interim evaluations using new seismic sources and ground motion with old hazard while the longer-term risk evaluation is performed. --'\ NTTF 2.1-Interim Expedited Approach (ESEP) CEUS: 12/31/2014; WUS: 1/16 . If the design basis does not bound reevaluated hazard: licensees perform interim evaluation to demonstrate key pieces of equipment for core cooling at a higher hazard using installed FLEX equipment \ up to 2 x SSE. Evaluate need for modifications while longer-term risk evaluation is performed. / NTTF 2.1-Seismic Risk Evaluations: June 2017-2020 l If the design basis does not bound reevaluated hazard: Licensees determine perform a seismic risk evaluation. Regulatory Actions NRC staff determines whether additional regulatory actions are necessary to provide additional protection against the updated hazards. 7 \--U.S.NRC J ,.,_.., '" ou.o;n. rnmr Pratecti>l,r: Pu>/>le and thP. F.nvirmrmeut Probabilistic Approach

• Previous studies such as 2011 Shoreline Fault Report and 2014 Coastal Commission Report were deterministic -Few selected scenario earthquakes -Limited treatment of uncertainty
• NTTF Recommendation 2.1 calls for seismic hazard reevaluations at each nuclear power plant using current NRG regulations
• Current NRG regulations and guidance specify a probabilistic approach for developing design ground motions
• Probabilistic ground motion hazards are characterized by a Ground Motion Response Spectrum or GMRS 8

\--U.S.NRC J ,.,_.., '" ou.o;n. rnmr Pratecti>l,r: Pu>/>le and thP. F.nvirmrmeut Development of Seismic Hazard for R2.1 Reeva I uations

• Licensees perform probabilistic seismic hazard analyses following NRC guidance (Regulatory Guide 1.208) **-*-c::::J ..*.* ... *. . . .. .. .. " .,,,., .. ..,,., ., ....
• CEUS licensees {96 units/59 sites) -Previously approved SSHAC Level 3 Models ...... -Plant-specific site analyses ....
• WUS licensees (6 units/3 sites) .________.,. i'. . . . . .. -Regional source and ground motion models developed by each Licensee using SSHAC Level 3 Studies -Plant-specific site analyses 9

, -U.S.NRC Screening Approach for R2. 1 Reeva I u at ions

• Screening approach specified in Industry Screening, Prioritization, and Implementation Details (SPID) Guidance
• SPID provides detailed guidance for -Development of GMRS -Seismic Risk Evaluations & Limited Scope Evaluations (high frequency, SFP)
• Plants with GMRS >SSE "Screen In" for -Interim Evaluations (and actions, as needed) -Expedited Interim Evaluations (and actions, as needed) -Seismic Risk Evaluations 10

\--U.S.NRC J ,.,_.., '" ou.o;n. rnmr Pratecti>l,r: Pu>/>le and thP. F.nvirmrmeut Outcome 1 ,, ,,,-----=--=-.::::-.::::: ___________ ---------::.,;;==::::*::_ ------0.1 10 frequency (Hz) Outcome 2 _£> c .Q -c;\lk\ (ti -"'I*. (i) t> /_--(/) -----------.-**-"' ____ /><,, "' 0 ------.:.::=--------**-***-*---. . 0.1 10 frequency (Hz) 10-: 10-: Potential Outcomes for R2.1 Reevaluations No Further Analysis Outcome 3 --S:-.1. \ v 0--00 -===------------' 0.1 -o lOC frequency (Hz) Industry Testing Program for High Frequency Sensitive components 11 ,J. NRC Review of SSHAC ...,, .... ... , ... , .. Studies for WUS Sites

• Did SSHAC process follow NRC guidance?
• How effective was the peer review panel?
• Have all applicable data been considered?
• Were data uncertainties identified and considered?
• Was an appropriate range of applicable models considered?
• How were models selected and weighted in the analysis?
• How were models assembled into the PSHA? 12

,-U.S.NRC NRC Review of '""" ,,,," ............ "'""""""" ._,, .. ... , ... , ... Source Models for WUS Sites

• How were seismic sources identified? -Geologic mapping -Geophysical observations -Earthquake catalog
• How were seismic sources characterized? -Geometry (location, length, dip) -Range of magnitudes -Faulting style (normal, reverse, strike-slip) -Slip rate and recurrence models -Complex rupture scenarios 13

\--U.S.NRC J ,.,_.., '" ou.o;n. rnmr Pratecti>l,r: Pu>/>le and thP. F.nvirmrmeut NRC Review of Ground Motion Models and Site Response for WUS Sites

• Do final ground motion models capture a reasonable range of alternative models?
• How were sources of uncertainty captured in model development?
• How were ground motion models adjusted for local site geology?
• Does site response analysis cover a reasonable range of alternative soil/rock properties?
• How was uncertainty in site response analysis incorporated into final probabilistic hazard curves? 14

\--U.S.NRC J ,.,_.., '" ou.o;n. rnmr Pratecti>l,r: Pu>/>le and thP. F.nvirmrmeut Hazard Development Expedited Interim Evaluations Risk Evaluations Higher Priority Lower Priority Hazard Analyses Expedited Interim Evaluations 2012 I Schedule for Seismic Hazard and Risk Evaluations 2013 2014 2015 2016 2017 2018 2019 2020 CEUS '\

• wus
• All plants CEUS 121ant mods I
• mods Only plants wus I with new
• I Group 1 I Risk Evaluations Staff acknowledgement to use GMRS for risk evaluation seismic hazard exceeding design basis Group 2 Group 3 (as needed) e Staff Assessment or response -15 Forthcoming Seismic Screening Letter
• Issuance of letter for WUS sites in ---2 weeks
• Diablo Canyon has screened-in for further risk evaluations and is a review priority
• No immediate safety issues identified
• Information supports safety assurance allowing additional time to complete the seismic risk evaluation 16

\--U.S.NRC J ,.,_.., '" ou.o;n. rnmr Pratecti>l,r: Pu>/>le and thP. F.nvirmrmeut List of Acronyms

• CELIS -Central and Eastern United States
• GMRS -Ground Motion Response Spectrum
• NRC-U.S. Nuclear Regulatory Commission
• NPP -Nuclear Power Plant
• NTTF -Near-Term Task Force
• SFP -Spent Fuel Pool
• SMA-Seismic Margins Analysis
• SPID -Screening, Prioritization, and Implementation Details SPID
• SPRA-Seismic Probabilistic Risk Assessment
• SSC-Structures, Systems and Components
• SSHAC -Senior Seismic Hazard Analysis Committee
• SSE -Safe Shutdown Earthquake
• SPID -Screening, Prioritization, and Implementation Details
• WUS -Western United States 17

,-U.S.NRC Break for NRC J ,.,_.., '" ou.o;n. rnmr Pratecti>l,r: Pu>/>le and thP. F.nvirmrmeut Staff Alignment

• 15 -20 minute planned break for NRC staff alignment to support meeting wrap-up
• Meeting to resume at 4:00pm (Eastern) or 1 :OOpm (Western) 18 Opportunity for Public Questions or Comments
• Additional Questions? Please ask us at: JLD _PublicResource@nrc.gov 19

\--U.S.NRC J ,.,_.., '" ou.o;n. rnmr Pratecti>l,r: Pu>/>le and thP. F.nvirmrmeut Backup Slides 20 , -U.S.NRC Additional WUS J ,.,_.., '" ou.o;n. rnmr Pratecti>l,r: Pu>/>le and thP. F.nvirmrmeut Seismic Hazard Reports Public SSHAC Reports

• Diablo Canyon http://www. pge. com/en/safety/systemworks/ dcpp/sshac/index. page 21

\--U.S.NRC J ,.,_.., '" ou.o;n. rnmr Pratecti>l,r: Pu>/>le and thP. F.nvirmrmeut Guidance Documents

• Two main guidance documents proposed by industry and endorsed by the NRC
• Screening, Prioritization, and Implementation Details (SPID) -Submitted by EPRI on November 2012 -Endorsed by NRC on February 15, 2013 -EPRl-1025287(ML12333A170)
• Seismic Evaluation Guidance: Augmented Approach (aka Expedited Approach) -Submitted by EPRI on April 9, 2013 -Endorsed by NRC on May 7, 2013 -EPRl-3002000704(ML13102A142) 22

\--U.S.NRC J ,.,_.., '" ou.o;n. rnmr Pratecti>l,r: Pu>/>le and thP. F.nvirmrmeut Seismic 2.1 Process Ensures Clarity, Consistency, and Informed Regulatory Decisions ----------------------------, PHASE 1 INFORMATION GATHERING STAGE 1 STAGE 2 Interact with Industry on Hazard and Risk Evaluation Guidance CEUS Licensees submit Site Response (9/2013 & 3/2014) Screened-in plants complete Expedited Approach Interim (CEUS: 12/31/2014;WUS: 1/2016) and Risk Evaluation (Group 1: 2017) N RC reviews Risk Evaluation ----------------1 PHASE 2 DECISION-MAKING N RC makes Regulatory Decisions as Needed *Safety Enhancements

• Backfit Analysis *Modify Plant License '----------------23 DiFranccsco, Nicholas From:DiFrancesco, Nicholas Sent:26 May 2015 17:40:31 +0000 To:Watford, Margaret Cc:Singal, Michael

Subject:

Columbia References for Seismic Hazard Reportability and Operability Reference for beyond design basis seismic hazard information:

• N RC letter to industry with guidance on tt1e content of seismic reevaluation submittals (February 20, 2014) Columbia Safety Basis -Section 5.0 Interim Evaluations contains Seismic GDF estimates and insights into plant capacity.
• http://pbadupws.nrc.gov/docs/ml1507/ML 15078A243.pdf DiFranccsco, Nicholas From:DiFrancesco, Nicholas Sent:2l Apr 2015 17:25:14 +0000 To: Munson, Clifford;Akc, Jon Cc :Jackson, Diane;Shams, Mohamed; Vega, Frankie;Graizer, Vladimir;John Stamatakos <jstam@swri.org> (jstam@swri.org);Hill, Brittain;Seber, Dogan;Vega, Frankie;Stirewalt, Gerry

Subject:

DCPP, Palo Verde, and Columbia Audit Information: SSHAC Documentation from PPRP-IT Team Folks, Please control distribution to the designated review team member for the following references. Following your audit review, please advise if information reviewed should be docketed to support development of the hazard staff assessment or RAls. DC Audit Information S:\Diablo Canyon R2.1 Seismic lnformation\SSHAC Documentation of PPRP-TI Team Palo Verde Audit Information S:\Palo Verde R2.1 Seismic lnformation\SSHAC Documentation of PPRP-TI Team Columbia Information is on ePortal (PM action to work through access controls). Also, licensee plans to work with PNNL to post information on public website. Thanks, Nick From: Soenen, Philippe R [12] Sent: Tuesday, April 21, 2015 10:49 AM To: Difrancesco, Nicholas Cc: Jahangir, Nazar

Subject:

DCPP information on Certrec Nick, We have uploaded the PPRP information onto Certrec IMS and granted access to Vladimir Grazier, John Stamatakos, and yourself. Here is how you get to the PPRP information in Certrec:

• Login to ims.certrec.com
• Click on "Inspections"
• Set status to "In Progress" and Plant to "Diablo Canyon"
• Click "Search" button.
• Click link to "Self-Assessment I Audit-Review of PPRP Comments and TIT Resolution"
• Click on the "NRC Requests" tab
• Click on what you would like to see.

Please let me know if you have any questions. Regards, Philippe Soenen Regulatory Services Office -805.545.6984 Cell -805.459.3701 PG&E is committed to protecting our customers' privacy. To learn more, please visit http://www.pge.com/about/company/privacy/customer/ Sticvc, Alice From:Stieve, Alice Sent:2l Apr 2015 13:45:28 -0400 To:DiFranccsco, Nicholas Cc:Jackson, Diane;Munson, Clifford

Subject:

FW: DCPP, Palo Verde, and Columbia Audit Information: SSHAC Documentation from PPRP-IT Team Nick please include me on future Palo Verde emails. I am the geologist and team lead on PY. Thanks. From: Hill, Brittain Sent: Tuesday, April 21, 2015 1:32 PM To: Stieve, Alice

Subject:

FW: DCPP, Palo Verde, and Columbia Audit Information: SSHAC Documentation from PPRP-IT Team From: Difrancesco, Nicholas Sent: Tuesday, April 21, 2015 1:25 PM To: Munson, Clifford; Ake, Jon Cc: Jackson, Diane; Shams, Mohamed; Vega, Frankie; Graizer, Vladimir; John Stamatakos <jstam@swri.org> (jstam@swri.org); Hill, Brittain; Seber, Dogan; Vega, Frankie; Stirewalt, Gerry

Subject:

DCPP, Palo Verde, and Columbia Audit Information: SSHAC Documentation from PPRP-IT Team Folks, Please control distribution to the designated review team member for the following references. Following your audit review, please advise if information reviewed should be docketed to support development of the hazard staff assessment or RAls. DC Audit Information S:\Diablo Canyon R2.1 Seismic lnformation\SSHAC Documentation of PPRP-TI Team Palo Verde Audit Information S:\Palo Verde R2.1 Seismic lnformation\SSHAC Documentation of PPRP-TI Team Columbia Information is on ePortal (PM action to work through access controls). Also, licensee plans to work with PNNL to post information on public website. Thanks, Nick From: Soenen, Philippe R [13] Sent: Tuesday, April 21, 2015 10:49 AM To: Difrancesco, Nicholas Cc: Jahangir, Nazar

Subject:

DCPP information on Certrec Nick, We have uploaded the PPRP information onto Certrec IMS and granted access to Vladimir Grazier, John Stamatakos, and yourself. Here is how you get to the PPRP information in Certrec:

• Login to ims.certrec.com
• Click on "Inspections"
• Set status to "In Progress" and Plant to "Diablo Canyon"
• Click "Search" button.
• Click link to "Self-Assessment I Audit -Review of PPRP Comments and TIT Resolution"
• Click on the "NRC Requests" tab
• Click on what you would like to see. Please let me know if you have any questions. Regards, Philippe Soenen Regulatory Services Office -805.545.6984 Cell
• 805.459.3701 PG&E is committed to protecting our customers' privacy. To learn more, please visit http://www.pge.com/about/company/privacy/customer/

Wyman, Stephen From:Wyman, Stephen Sent: 17 Mar 2015 20: 16: 12 +0000 To:Jackson, Diane Cc: Dev Ii n-Gi 11, Stephanie;M unson, Clifford

Subject:

FW: Palo Verde FSAR Diane, Palo Verde FSAR latest is Rev 17, ADAMS Accession Package No. ML 13214A057. The referenced sections were 2.5 for SSE and 3. 7 for the design basis. I don't see how they are *'special". Regards. Steve Stephen M. Wyman USNRC/NRRIJLDIHMB Office: 0-13G9 MS: 0-13C5 301-415-3041 (Voice) 301-415-8333 (Fax) Stephen.Wyman@nrc.gov From: Singal, Balwant Sent: Tuesday, March 17, 2015 4:08 PM To: Wyman, Stephen

Subject:

RE: Palo Verde FSAR Latest I know of is Revision 17. ADAMS Accession Package No. ML 13214A057. Thanks. Balwant K. Singal Senior Project Manager (Comanche Peak and Palo Verde) Nuclear Regulatory Commission Division of Operating Reactor Licensing Balwa nt.Singa l@nre.gov Tel: (301) 415-3016 Fax: {301) 415-1222 From: Wyman, Stephen Sent: Tuesday, March 17, 2015 3:52 PM To: Singal, Balwant

Subject:

Palo Verde FSAR Balwant, Can you please confirm for me the latest Rev of the FSAR for Palo Verde? I currently find Rev 16 dated June 2011 on the network. (Y:/CDIMAGES/FSAR) The staff has a question regarding their seismic design basis as it related to the recently submitted seismic hazard report. Thanks, Steve Stephen M. Wyman USNRC/NRRIJLDIHMB Office: 0-13G9 MS: 0-13C5 301-415-3041 (Voice) 301-415-8333 (Fax) Stephen.Wyman@nrc.gov DiFranccsco, Nicholas From:DiFrancesco, Nicholas Sent:25 Mar 2015 14:58:38 +0000 To:Hill, Brittain;Jackson, Dianc;Shams, Mohamed Cc:Wyman, Stephen

Subject:

FW: Palo Verde Pages from Original Plant SER Attachments:Pages from Palo Verde SER.pdf Folks, Spoke with APS, about beginning preps for an interim evaluation and licensing basis clarification letter. The licensee maintains that their history relatively short history is nuanced. Attached is a seismic SER excerpt that they said explained it. I don't think it changes the current understanding. Thanks, Nick From: Weber, Thomas N Sent: Tuesday, March 17, 2015 6:13 PM To: stephen.wyman@nrc.gov

Subject:

Palo Verde Pages from Original Plant SER Stephen, I am sending you some pages from our original plant safety evaluation report for your information and use. You will note the unique wording that the NRC used to described both the seismic site characterization values in section 2.5 as well as the seismic design values in section 3.7. We tried to distinguish the difference in our submittal. We look forward to future discussions on this topic. Thanks, TN Weber ... Department Leader Regulatory Affairs PVNGS 623-393-5764 I I / FOR INFORMATION ONLY NUREG-0057 Safety Evaluation Report_. .. related to the operation of . Palo Verde Nuclear Generating Station:;r Units 1, -2, and 3 Docket Nos. STN 50-528, STN 50-529, and STN 50-530 Arizona Public Service Company, et al. U.S. Nuclear Regulatory Commission Office of Nuc ... r RNctor Regulation November 1981 ., site. This is the largest earthquake which has been reported within 161 km (100 mi) of the PVNGS site. The staff concluded that this earthquake is associated with the Basin and Range Tectonic for the purpose of iaple11enttng Appendix A to 10 CFR Part 100 and found that a .agnitude 5.2 event could occur near the site (CP-SER for PVNGS 4-5, 1979). The other significant seismic zone is the zone containing the epicentral area of the 1887 Sonora Mexico earthquake. The Sonora earthquake was located about 443 km (275 *i) southeast of the PVHGS site. The reported epicentral intensity of the Sonora earthquake was K*KI (Modified Mercalli). The applicant's estimated .. gnitude is approxi*atey 7 3/4 to 8 (M5); the.Dubois and Sbar (1981) esti*ated *agnitude is 7 1/4 (M5). The applicant has assumed that an event similar in size to the 1887 Sonora earthquake of magnitude 8 occurs 116 km (72 mi} northeast of the site. This position corresponds to the closest approach to the site.of a line which coincides with e series of long northwesterly*trending valleys and atsociated Quaternary and capable faults which project ff'Oll the epicentral area to the Grand Canyon region. The Ari2ona Bureau of Geology and Mineral Technology, in eooperat;on with the Department of Geosciences, University of Arizona, is conducting a study of historical seismicity in Arizona, partly funded by the NRC. Early results from the study (Dubois, 1980) summarize previous earthquake investigations, the current attempt to document historical earthquakes in Arizona, and analysis of the location and size of these historic earthquakes. The historical quakes have been tentatively grouped into four basic zones of seismicity. The staff has reviewed the technical progress report (Dubois, 1980) and finds no impact resulting from this study on the seismic risk for the PVNGS site. The applicant has agreed to update the FSAR to include the results of this study when completed. 2.S.2.4 Safe Shutdown Earthquake (SSE) In determining the SSE, the staff has followed the tectonic province approach described in Appendix A to 10 CFR Part 100. The applicant has proposed an SSE acceleration level of O.ZOg which corresponds to an event of magnitude 8 similair in size to the 1887 Sonora earthquake occurring at a distance of 116 km (72 mi) northeast of the site. This acceleration value is used as the high frequency input to a RG 1.60 response spectrum. During the CP review, the USGS agreed with the applicant's conclusion that an acceleration of 0.2g is adequate for use 1t the site (CP*SER for PVNGS 1*3, Supp. No. 2, 1976). The USGS examined the following situations in assessing the adequacy of the proposed SSE. 1. A San Andreas-type event of magnitude 8+ about 200 km (124 mi) from the site. .... 2. A *agnitude 8 Sonora. Mexico-type event 115 km (72 mi) from the site. 3. A random event of magnitude 5.0 within the site province. During the CP review, the staff and the USGS assessed the adequacy of the SS£ for the above situations based on 1) empirical relations among magnitude, Palo Verde SER 2-24 01 o' 11 \ FOR INFORMATION ONLY epicentral distance and accleration, and relations among acceleration, intensity and distance and 2) empirical relations among site intensity, epicentral intensity and distance and relations between acceleration and intensity. The spectra four seismograms from the 1952 Kern County earthquake and two from the 1971 San Fernando earthquake were scaled for distance and magnitude. The applicant showed that the resultant spectra are conservatively enveloped with the RG 1.60 spectrum anchored at 0.2g. The staff and the USGS agreed that for the Palo Verde site, 0.2g is an adequate value to be used as the high-frequency input to RG 1.60 response spectra. In the CP review for Units 4 and 5 at the PVNGS site (CP-SER for PVNGS 4-5, 1979), the staff considered the effects of a magnitude S.2 earthquake similar to the 1976 Prescott event occurring near the site. (Detailed geologic gations in the site area have precluded the existence of any capable *faults within 8 km (5 mi) of the site.) Based again on empirical relationships. the staff concluded that the acceleration from a *agnitude S.2 earthquake assumed to occur 8 km (5 mi) from the site would not be expected to exceed 0.2g. The staff's position is that the following seismic hazards likely to affect the PVNGS site should be considered: 1. A magnitude 8 Sonora. Mexico-type event at a distance of 115 km (72 mi) from the site. 2. A random event of magnitude 5.2 (ML). Since the CP review for Units 4 and S, all available information supports the position that the SSE response spectra are conservative for a Sonora-type event at 115 km (72 mi) from the site. The applicant has further demonstrated the ** conservatism of the 0. 2g SSE design spectrum with respect to a nearby magn tude 5.2 event by comparing the SSE and site-specific spectra generated by Lawrence Livermore Laboratories (LLL) (1979). The SSE spectrum exceeds the 84th percentile LLL spectrum for magnitude 5.3 at soil sites at all periods except for minor exceedance between 0.04 and 0.05 seconds. The SSE spectrum the SOth percentile LLL spectrum at all periods by factors between 2 and 10. The staff and the staff consultant at Los Alamos National Laboratory agree that the proposed acceleration value of O.ZOg, as the high frequency anchor to a RG 1.60 response spectrum, is adequately conservative as the SSE for the PVNGS site. 2.S.2.S Operating Basis Earthquake (OBE) The applicant has proposed O.lOg for the acceleration level corresponding to the OBE. The design vibratory ground acceleration for the OBE is taken to be one-half of the design vibratory ground acceleration for the SSE, consistent with dix A to 10 CFR 100. Considering the low seismicity near the PVNGS site, the staff concludes that the proposed acceleration viHue for the OBE is adequately conservative. 2.5.3 Surface Faulting Post-CP (Units 1, 2, and 3) site and regional subsurface information reinforces the NRC staff finding that there is no known evidence either at the PVNGS 1-3 site or within 8 km (5 mi) of the nuclear plants to indicate surface Palo Verde SER 2-25 I I FOR INFORMATION ONLY 3.7 SEISMIC DESIGN 3.7.1 Seismic Input The input seismic design response spectra based on the Maximum horizontal ground motion of 0.13 g for OBE and 0.25 g for SSE and applied in the design of BOP seismic Category I structures, systems. and components comply with dations of RG l.60, Design Response Spectra for Nuclear Plants.** The specific percentage of critical damping values used in the seismic analysis of Category I structures, systems and components within the balance*of-plant (BOP) scope are in conformance with RG 1.61, "Damping Values for Seismic Analysis of Nuclear Power Plants ... The synthetic time history used for the seismic design of BOP Category I plant structures, systems and components is adjusted in amplitude and frequency content to obtain response spectra that envelope the response spectra specified for the site. Conformance with the reconmendations in RG 1.60 and RG 1.61 provides reasonable assurance that the seismic inputs to BOP Category I structures, systems, and components are adequately defined to assure a conservative basis for the design of such structures, systems and components to withstand the consequent seismic loadings. A discussion of the. conformance of the spectra and damping values used in the design and analysis of NSSS Category I structures, systems. and components with RG 1.60 and RG 1.61 is contained in NUREG-0852. Section 3.7. The staff concludes that the PVNGS response spectra 3re enveloped by the response spectra developed for the NSSS components, and, therefore. the CESSAR interface requirements are satisfied. The staff does have a concern on the use of high damping values in the design of cable trays for PVNGS 1-3. Since these damping values are much higher than those recommended in RG 1.60 for steel structures. the staff requested that the applicant provide the theoretical basis and a further discussion of the experimental data for staff review and evaluation. The resolution of this item is pending receipt, review and acceptance of this information. 3.7.2 Seismic System Analysis and Seismic Subsystem Analysis (Structural) The scope of review of the seismic system and subsystem analys;s for PVNGS 1*3 Category I structures, systems and components included the seismic analysis. It also included a review of procedures for Modeling, seismic soil*structure interact;on, development of floor response spectra. inclusion of torsional effects, evaluation of seismic Category I structures overturning, and determina* tion of composite damping. In addition, the review included design criteria and procedures for evaluation of the interaction of nonseismic Category I struc* tures with seismic Category I structures. effectS""Of parameter variations on floor response spectra, and seismic Category l buried piping outside the ment. A discussion of the review of the seismic analysis of the structural. components of NSSS systems and subsystems is found in NUREG-08S2, Section 3.7. A structural engineering audit was held during the week of August 10. 1981. At the conclusion of that meeting, the staff requested that the applicant furnish justification that the corridor building and a Category I buried pipeline had Palo Verde SER 3*17 V cga, Frankie From: Vega, Frankie Sent:3 Jun 2015 11:07:58-0400 To:DiFranccsco, Nicholas

Subject:

FW: Proposed agenda -Public meeting to discuss Columbia's seismic hazard reevaluation From: Williams, Lisa L. [14] Sent: Thursday, May 21, 2015 3:57 PM To: Vega, Frankie

Subject:

RE: Proposed agenda -Public meeting to discuss Columbia's seismic hazard reevaluation See minor change in red below From: Vega, Frankie [15] Sent: Tuesday, May 19, 2015 1:51 PM To: Williams, Lisa L.

Subject:

RE: Proposed agenda -Public meeting to discuss Columbia's seismic hazard reevaluation Thanks Lisa! From: Williams, Lisa L. [16] Sent: Tuesday, May 19, 2015 4:43 PM To: Vega, Frankie; Rogalski, Richard J. Cc: Difrancesco, Nicholas

Subject:

RE: Proposed agenda -Public meeting to discuss Columbia's seismic hazard reevaluation Frankie. Here are the attendees for Energy Northwest: In person Dave Swank-Assistant Vice President, Engineering and Fukushima Project Leader Mike Kennedy-PSA/Safety Analysis Supervisor Lisa Williams -Licensing Supervisor Greg Lisle -Design Engineer Kevin Coppersmith -consultant Bob Youngs -consultant Via telephone Bob Bryce -consultant Habib Shtaih -PSA Engineer Rich Rogalski -Licensing Engineer From: Vega, Frankie [ mailto: Frankie.Vega@nrc.gov] Sent: Tuesday, May 19, 2015 12:53 PM To: Williams, Lisa L.; Rogalski, Richard J. Cc: DiFrancesco, Nicholas

Subject:

Proposed agenda -Public meeting to discuss Columbia's seismic hazard reevaluation Mrs. Williams and Mr. Rogalski; My name is Frankie Vega and I'm one of the PMs involved with 2.1 Seismic. Please see the agenda below for the upcoming public meeting on Columbia's reevaluated seismic hazard. Feel free to modify the agenda if needed. I would appreciate your comments/edits by COB Thursday since I plan to issue the meeting notice this Friday. Also, please send us a list of your staff and contractor personnel that are planning to participate in the meeting (either attending or calling -in). Feel free to contact either Nick or me with any questions. Time 12:00-12: 15 12:15* 12:30 12:30-2:45 2:45-3:05 3:05-3:20 3:20-4:00 Thanks! Topic Introductions Overview of R2.1 Seismic -Discussion of meeting goals and expected outcome Presentation of Seismic Reevaluation Report SSHAC Activities Seismic Source and Ground Motion Model Technical Focus Areas and Discussions Discussion of licensee next steps Planned Break NRC Meeting Wrap-up Technical Wrap-up, review of focus areas and next steps Public Questions or Comments Speaker NRC/Energy Northwest NRC Energy Northwest NRC Public/NRC ..... Frankie G. Vega, P .E. Project Manager NRR/JLD/JHMB 301-415-1617 Location: 0-13Hl2 DiFranccsco, Nicholas From:DiFrancesco, Nicholas Sent:l4 May 2015 16:07:06 +0000 To:NRR-PMDA-ECapturc Resource Cc:50.54f_Seismic.Resource@nrc.gov

Subject:

FW: Written concerns -April 28th, 2015 webcast meeting with PG&E Attachments:Written concerns -April 28th, 2015 webcast meeting with PG&E Please add to PUBLIC ADAMS, sunsi review complete. A release date of May 21 is preferred. Thanks, Nick Senior Project Manager -Seismic Reevaluation Activities U.S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Japan Lesson Learned Project Division nicholas.difrancesco@nrc.gov I Tel: (301) 415-1115 STATE OF CALIFORNIA EDMUND G. BROWN JR., GOVERNOR Independent Peer Review Panel A pcvl'U!/b ef J-'fJ/1:-J*-m-vo fuvg-a-rd,, ;pe,c.-;,a,Z.,,:-;*tJ* f!/,,,C-a;biv,yft.ed,, try t"M Ca;[,:,f'o-rl'l/ia-pul>-lz,o U t"t/Ut'UJ-* C o-m/Jn/v,1-;1*iorl/ CALIFORNIA GEOLOGICAL SURVEY, CALIFORNIA COASTAL COMMISSION CALIFORNIA PUBLIC UTILITIES COMMISSION, CALIFORNIA ENERGY COMMISSION CALIFORNIA SEISMIC SAFETY COMMISSION, COUNTY OF SAN LUIS OBISPO IPRP Report No. 8, December 17, 2014 Comments on PG&E's Central Coastal California Seismic Imaging Project Report part 2: onshore seismic studies intended to reduce the uncertainty in seismic hazard at Diablo Canyon Power Plant BACKGROUND In 2006, the California Legislature enacted Assembly Bill (AB) 1632, which was codified as Public Resources Code Section 25303. AB 1632 directed the California Energy Commission (CEC) to assess the potential vulnerability of California's largest baseload power plants, which includes Diablo Canyon Power Plant (DCPP), to a major disruption due to a major seismic event and other issues. In response to AB 1632, in November 2008 the CEC issued its findings and recommendations in its AB 1632 Report, which was part of its 2008 Integrated Energy Policy Report Update. In Pacific Gas and Electric Company's (PG&E) 2007 General Rate Case decision D.07-03-044, the California Public Utilities Commission (CPUC) directed PG&E to address and incorporate the recommendations from the AB 1632 Report into its feasibility study to extend the operating licenses of its Diablo Canyon Units 1 and 2 for an additional 20 years. In November 2009, PG&E submitted its formal application with the Nuclear Regulatory Commission to extend the licenses of DCPP Units 1 and 2. In 2010 PG&E filed for cost recovery with the CPUC for expenditures associated with the enhanced seismic studies recommended by the CEC's AB 1632 Report. The motions for cost recovery were subsequently approved in 2010 and 2011 . CPU C Decision D .10-08-003, issued on August 16, 2010, established that the CPUC would convene its own Independent Peer Review Panel (IPRP) and invite the CEC, the California Geological Survey, the California Coastal Commission, and the California Seismic Safety Commission to participate on the panel. Under the auspices of the CPUC, the IPRP is conducting an independent review of PG&E's seismic studies including independently reviewing and commenting on PG&E's study plans and the findings of the studies. The comprehensiveness, completeness, and timeliness of these studies will be critical to the CPUC's ability to assess the cost-effectiveness of Diablo Canyon's proposed license renewal. As noted in the CEC's AB 1632 Report, a major disruption because of an earthquake or plant aging could result in a shutdown of several months or even cause the retirement of one or more of the plants' reactors. A long-term plant shutdown would have economic, environmental and reliability implications for California ratepayers. This report by the IPRP responds to reports released by PG&E on September 10, 2014. Those reports are collectively referred to as the Central Coastal California Seismic Imaging Project (CCCSIP) report. The CCCSIP report is divided into 14 chapters focused on individual studies. This review, and subsequent reviews of the CCCSIP, are divided into sections based on factors that are important to seismic hazard analysis and the studies intended to help constrain those factors. In this organization and emphasis, these reports by the IPRP follow the format of IPRP Reports No. 2 and 3 and refer to investigation "targets" described in a memo report "Response to IPRP Request for Hazard Sensitivity for Targets for the DCPP Geophysical Surveys," that was prepared by the PG&E Geosciences Department and dated August 8, 2011. Due to the large volume of information in the CCCSIP report, the IPRP chose to review it in three parts. The second part includes onshore seismic studies and the hazard parameters that they are designed to study. These studies, Chapters 7, 8, 9 and 12 of the CCCSIP report, were the subject of a public meeting on November 17, 2014 and of this report. At the IPRP meeting on November 17, 2014, PG&E project manager Stuart Nishenko presented an update of the "tornado diagram" from the August 11, 2011 memo report. In the updated "tornado diagram" (Figure 1 ), the distance between points related to a hazard parameter represents the uncertainty in seismic hazard resulting from that parameter. In this type of diagram, parameters that are poorly constrained and have a Hosgri Slip Ra1e . *J Hosgri Dip-+----------",_.------++-----< Shoreline Slip Rate . .J* Hosgn -San Simeon Step Over * *..!I

• Los Osos Dip *..!l*..!1* *_J
• Los Osos Sense of Slip +-------+---1t----1 *J Shoreline and Hosgri Linking . *..!I 2011 2014 Los Osos Slip Rate+-------;,,,. .. _ -+-------+---t Shoreline Segmentation Shoreline Southern End -+--------------+---< 0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 Figure 1. "Tornado diagram" from CCCSIP report. chapter 14, showing seismic hazard parameters and related uncertainty in seismic hazard. Values depicting state of knowledge in 2011 and 2014 show reduction in uncertainty related, in part, to CCCSIP studies.

large effect on hazard are shown as widely separated points at the top of the diagram. Closely spaced points shown near the base of the diagram can be either parameters that are well-constrained or parameters that are poorly-constrained but have slight effect on hazard. As stated by Dr. Nishenko, reducing the uncertainty in the parameters near the top of the "tornado" will have the greatest effect in reducing the uncertainty in hazard. The depiction of uncertainty in 2011 and 2014, particularly the lower uncertainty for the parameters at the top of the "tornado" show PG&E's estimate of how much uncertainty in seismic hazard has decreased due to studies described in the CCCSIP report. The parameter with the greatest impact on seismic hazard, slip rate on the Hosgri fault, was the main subject of IPRP Report No. 7. This report includes discussion of seismic hazard parameters including dip and sense of slip on the Los Osos fault (fourth and fifth from the top of the "tornado"). The IPRP notes that the parameters shown on the "tornado diagram" are the parameters included in the 2011 seismic hazard analysis. As stated in IPRP Reports No. 2 and 3, an important emphasis of on-land seismic surveys should be to determine if there are additional faults that should be considered and an overall "tectonic model" describing the location. sense of slip, and level of activity on faults within the Irish Hills. As in IPRP Report No. 7, the IPRP notes that the parameters shown on the "tornado diagram" are all "seismic source characterization" parameters. Other parameters, especially "site conditions" or "site amplification" parameters can have equal or greater impact on seismic hazard calculations as any shown on Figure 1. Site conditions and seismic amplification factors were the subject of IPRP Report No. 6 and are discussed in other sections of the CCCSIP report. These factors will be addressed in a subsequent IPRP report. Seismic hazard parameters addressed in Chapters 7, 8, 9 and 12 of the CCCSIP report and discussed here are:

• Los Osos dip
• Los Osos sense of slip
• Tectonic model of the Irish Hills
• Evaluation of hazard related to the Diablo Cove fault and the San Luis Range Fault. The major emphasis of this part of the CCCSIP is to develop a complete and consistent tectonic model of the Irish Hills, which includes dip and sense of slip on all faults, including the Los Osos fault. This review, therefore. follows the general organization of the CCCSIP report and presentations at the IPRP meeting on November 17, 2014, beginning with, 1) a discussion of studies intended to develop tectonic models of the Irish Hills, 2) how well those studies constrain seismic hazard parameters, (e.g.,dip of IPRP Report No. 8, Page 3 the Los Osos fault), and 3) use of those models in seismic hazard analysis. A separate section discusses Chapter 12 of the CCCS IP report, which is an evaluation of fau Its and tectonic models proposed by Dr. Douglas Hamilton and presented by Dr. Hamilton at the IPRP meeting on November 17, 2014. Onshore seismic interpretation program (ONSIP) The major data collection efforts described in Chapters 7, 8 and 9 of the CCCSIP report were seismic surveys of the area surrounding the DCPP, including the Irish Hills collectively referred to as the onshore seismic interpretation program (ONSIP). This effort was supplemented by updated geologic mapping, new surveys of gravity and magnetics, and interpretation of available data from previous oil and water wells. Seismic surveys were conducted in 2011 and 2012 and consisted of two types of seismic sources and arrays of receivers. The sources, truck-mounted Accelerated Weight Drop (AWD) and Vibroseis vehicles, were deployed along roads throughout the Irish Hills and receivers were deployed on the roads and in grid arrays where allowed by the terrain and landowners. As described in the CCCSIP report and in the November 17, 2014 IPRP meeting by Dr. Daniel O'Connell of Fugro Consultants, the highly irregular source and receiver layout posed challenges for processing, hence all data were processed with 30 methods. Processed seismic survey data were presented in the CCCSIP report and at the IPRP meeting as 2-dimensional cross sections along the lines where surveys were conducted, mainly along roads across the hills. In general, AWD surveys produced relatively high resolution to shallow depths and Vibroseis surveys produced lower resolution to greater depth. The surveys show "reflections" related to changes in seismic velocity of the materials. The processed seismic reflection data were interpreted by a team from PG&E and their consultants. The CCCSIP report (Chapter 7, page 25) lists assumptions upon which the team's interpretations are based, including: "We assume that variations in the acoustic properties of the rocks that give rise to the seismic reflectors directly or indirectly represent real geologic structure". In practice, observed reflections generally are assumed to represent bedding or other geologic fabric. The reflections further arre assumed to be caused by contrasts in acoustic impedance (the product of acoustic velocity and rock density) between adjacent geologic features. Faults are assumed to truncate or offset otherwise continuous geologic units, and thus are interpreted from related changes in observed reflections. Note also that the interpretation of seismic sections needs to take into account the possibility that some observed events are artifacts. On a given 20 section, observed reflections may come from features that are not in the plane of the cross-section. Observed events may also be artifacts created by assumptions built into the seismic data processing. Use of the sections derived from the IPRP Report No. 8, Page 4 seismic survey data to develop a tectonic model of the Irish Hills is described in Chapter 7 of the CCCSIP report. This chapter and the presentation by Dr. Jeff Unruh at the IPRP meeting on November 17, 2014 describe the evidence for the Los Osos, Edna. San Miguelito, San Luis Bay and additional un-named faults. Chapter 7 and the presentation emphasized the seismic surveys, but also described the use of geologic mapping, surveys of the gravity and magnetic fields, and well data in developing a tectonic model for the Irish Hills. The tectonic model described in Chapter 7 of the CCCSIP report includes a series of faults, generally dipping steeply toward the center of the hills (Figures 5-30, 5-31 and 5-32 of the CCCSIP report). The major faults are interpreted as having formed as extensional faults (normal faults) during Miocene time. Movement on these faults formed a deep basin that was filled with sediment that became the Obispo, Monterey, and Pismo Formations. In this model, faults formed as normal faults, possibly with some lateral displacement, in the Miocene then were reactivated as reverse faults, also possibly with some lateral displacement, in the Quaternary. This model is consistent with 1) potential field (gravity and magnetic) data, 2) the great thickness of Miocene sedimentary rocks encountered in the "Honolulu-Tidewater 1" oil well in the central Irish Hills, and 3) surface geologic mapping. The CCCSIP report does not thoroughly address the extent to which the geologists who developed this model considered alternative models which match the observed data equally well. Neither does the CCCSIP quantify the impact of potential alternative models on the seismic hazard. These issues were the subject of discussion at the IPRP meeting on November 17, 2014, which is summarized below. There are two types of questions about the faults that are included in the tectonic model: How well documented are they? And how much do they contribute to seismic hazard? Some faults, such as the Edna and San Luis Bay faults, are known from surface geologic mapping and can be projected some distance into the subsurface using the seismic reflection data. In some instances, truncated reflections in seismic sections presented in the CCCSIP report can reasonably be attributed to the downward extension of known surface faults. Such correlation of truncated reflections with surface faults can be accomplished with some confidence in the shallow subsurface, but becomes increasingly difficult with depth. The IPRP is not convinced that the interpretations of the down-dip extensions of faults are well constrained, even in the case of well-documented surface faults. Similarly, faults interpreted from the seismic sections, but not corroborated by surface mapping, (e.g. faults interpreted between the San Miguelita and Edna faults) are possible, but are by no means unique interpretations of the data. Overall. the IPRP is not convinced that projections of faults beyond the very shallow subsurface represented unique interpretations of the data. IPRP Report No. 8, Page 5 Projections of faults to depth in "basement" rocks of the Franciscan complex appear to be even more problematic. As discussed at the IPRP meeting on November 17, 2014, the Franciscan complex is known to be a mixture of different rock types pervasively sheared at a variety of scales and is not expected to produce reflectors that are extensive over broad areas. The majority of seismic sections, (e.g. AWD line 150 as presented on Chapter 7, Figure 5-25) show prominent, continuous reflectors at relatively great depths in material that is assumed to be bedrock of the Franciscan complex. Most deep reflectors shown on Figure 5-25, and in many other sections are arranged in groups of concave-upward, gently curved reflectors. These reflectors are interpreted in the CCCSIP report as representing geological structure. The IPRP, however, regards this pattern of concave-upward sets of reflectors as difficult to explain geologically, but not difficult to envision as artifacts from the data processing. If the continuous reflectors in Franciscan complex bedrock are artifacts of data processing, rather than representing geologic structure, then the seismic reflection surveys provide no constraint on the down-dip geometry of faults in the Franciscan Complex. The Los Osos fault, in particular, is entirely within Franciscan Complex rocks from very shallow depths. If the reflection surveys do not show real geologic structure along the down-dip extension of this fault, then dip of the fault remains essentially unconstrained. The question of how important the faults included in the tectonic model of the Irish Hills are in terms of seismic hazard is not addressed in the CCCSIP report, but was partly addressed in a presentation by Dr. Steve Thompson of Lettis Consultants International at the IPRP meeting on November 17, 2014. In that presentation, Dr. Thompson explained how the "Technical Integration (Tl) Team" working within the U.S. Nuclear Regulatory Commission's Senior Seismic Hazard Analysis Committee (SSHAC) process is developing input to the seismic hazard analysis. In contrast to the CCCSIP report, which attempts to present a single tectonic model as a unique result of the geophysical surveys, Dr. Thompson reports that the SSHAC "Tl team" is developing three alternative tectonic models for input into their seismic hazard analysis. One of these models is similar to the model described in the CCCSIP report, with faults that dip steeply toward the center of the Irish Hills, the two others are dominated by more gently dipping faults that dip either to the northeast or to the southwest. All else being equal, a tectonic model with relatively gently dipping thrust faults may result in higher hazard at Diablo Canyon for two reasons: the known vertical uplift of the Irish Hills requires a higher slip rate on a gently dipping reverse fault than on a steeply dipping one and most ground motion prediction equations predict higher ground motion for sites above (on the hanging wall of) thrust faults. IPRP Report No. 8, Page 6 The CCCSIP report describes some of the data to support a tectonic model including thrust faulting in discussion of the Honolulu-Tidewater 1 well (Chapter 7, page 43). It also presents analysis of seismicity that can be used to support a tectonic model that includes thrust faulting, based on the work presented by Dr. Jeanne Hardebeck (SSHAC workshop in San Luis Obispo, March, 2014, see (Chapter 12, Figure 6-47). The CCCSIP report does not, however, present a tectonic model with gently dipping thrust faults. Dr. Thompson's presentation indicates that the SSHAC seismic hazard analysis will consider three alternative tectonic models of the Irish Hills, including two with gently dipping thrust faults. The IPRP supports the concept of including three different tectonic models in seismic hazard analysis and has not seen a compelling reason to favor the model presented in the CCCSIP report over the other two described by Dr. Thompson. CONCLUSIONS IPRP review of the tectonic model is based on the CCCSIP report and presentation. The IPRP has not had time, to review the seismic data processing in detail. In addition, a full auditing of the seismic data acquisition and processing sequence would require the IPRP to retain outside consulting services. Evaluation of the figures showing seismic sections, however, has led to the following general conclusions:
• Seismic imaging of geologic structures deep beneath the Irish Hills was expected to present a significant challenge for both data acquisition and interpretation. The data and interpretations presented in the CCCSIP report increase our knowledge of several faults in the Irish Hills, particularly in the shallow subsurface. With increasing depth, however, there appears to be less support for the assumption that the "reflectors" shown in seismic sections represent "real geologic structure". As noted at the IPRP meeting, the most prominent, continuous reflectors in many sections are from relatively great depth in material that is assumed to be bedrock of the Franciscan complex. Since the Franciscan complex is known to be a mixture of different rock types pervasively sheared at a variety of scales, continuous, gently dipping layers are not expected. The overall arrangement of the gently dipping "reflectors" also raises questions that are not addressed in the report. In several sections, the arrangement of reflectors does not resemble a cross-section of folded or faulted rock. The pattern of concave-upward sets of reflectors seen in many sections does not have an obvious geological explanation, leading the IPRP to question whether they represent real geologic structure.
• Even if all reflectors shown in the seismic sections are images of geologic features, the interpretations of various faults are inconsistent and not unique: 1) In many cases, faults are interpreted based on a series of truncated reflectors, IPRP Report No. 8, Page 7 but are shown to pass through other reflectors that are not truncated: 2) In some seismic sections, it appears that additional faults are permitted by the data. It is not clear how the stated interpretation methodology allowed the interpretation team to draw some faults and not others; and 3) Alternate interpretations of the dip of most faults are possible. This concern applies to the dip of the Los Osos fault. Alternate dips, including relatively low-angle dips, of the Los Osos fault appear to be possible through sections 138-149 and 150 as shown on Figures 5-24 and 5-25 of the CCCSIP report. The reduction in uncertainty in seismic hazard depicted on the "tornado diagram" for dip of the Los Osos fault appears to be based on the CCCSIP report conclusion that the new data precludes low-angle dips. The IPRP does not concur that low-angle dips are precluded by this new data and therefore does not believe that these studies have resulted in reduced uncertainty in seismic hazard related to this parameter.
• Considering significant uncertainties in whether the seismic sections presented in the CCCSIP report represent "real geologic structure" and whether the faults shown on those sections represent preferred interpretations, the IPRP is not confident that the tectonic model described as being developed from these surveys is well constrained.
• The newly acquired seismic data may contain valuable new information that bears on the seismic hazard. However the interpretation process that resulted in a single tectonic model is hampered by significant data quality issues (associated in part with the irregular acquisition geometry) and a lack of significant subsurface control (see Ch. 7, page 70). An alternative approach exploring the full range of models allowed by the uncertainties of the data is preferable.
• The IPRP does not see a strong reason to favor the single tectonic model presented in the CCCSIP report over the two alternative models presented by Dr. Thompson at the IPRP meeting on November 17, 2014. CCCSIP Chapter 12: Response to Administrative Law Judge's Decision D.12-09* 008 Regarding Dr. Douglas Hamilton's Concerns The CCCSIP report's Chapter 12 addresses elements of tectonic models of the Irish Hills advanced by Dr. Douglas Hamilton. We focus on the two elements with clear hazard implications: 1) The San Luis Range Fault (SLRF), originally based on the Inferred Offshore Fault (IOF), as a major seismic source, and 2) The Diablo Cove Fault as a surface rupture hazard. In this review we focus on Dr. Hamilton's presentations at SSHAC and IPRP meetings and other references upon which the CCCSIP report is based. At this point we are not commenting on details of his presentation at the IPRP Report No. 8, Page 8 November 17. 2014 IPRP meeting, as this presentation included a preliminary new model for which no documentation has been provided. The model explaining the tectonic uplift of the Irish Hills hypothesized by Dr. Hamilton consists of a low-angle northeast-dipping thrust fault, the SLRF (Figure 6-12). underlying the Irish Hills with a postulated surface trace almost entirely offshore. This inferred fault, would have a length of 60-80 km extending from an intersection with the Hosgri fault, about 8 km south of Point Estero in the north, to the onshore mapped Wilmar Ave fault to the south (Figure 6-21 ). The SLRF proposed by Dr. Hamilton appears to be a variation of the Inferred Offshore Fault of Nitchman and Slemmons (1994), Figure 6-23 in Chapter 12. Along the central portion this inferred fault is coincident with the mapped Shoreline fault. The SLRF is interpreted by Dr. Hamilton to be a thrust fault dipping to the northeast that intersects the Shoreline fault at a depth of 1 to 2 km. He hypothesizes that this is the main structure accommodating regional northeast to southwest compression, which ultimately results in uplift of the Irish Hills. Uplift Boundary and SLRF Location Dr. Hamilton's proposed SLRF and Irish Hills uplift model are based on uplifted landforms, especially the well-documented series of Quaternary marine terraces (Hanson et al, 1994) and the longer term uplift of the Irish Hills block. Nitchman and Slemmons (1994), proposed the IOF to explain the uplift of the Irish Hills as well as the linear range front and coastline. The discovery of the now well-documented Shoreline fault along this section of the coast provides an explanation for the striking linearity of the coastline. Dr. Hamilton's model requires uplift to be localized at the trace of the SLRF, either at or near the surface. Therefore, because the SLRF is co-located along the central portion of the Shoreline fault, it follows that the Shoreline fault should exhibit signs of vertical movement. The series of uplifted coastal terraces provide vertical uplift rates of approximately 0.2 mm/yr, which should be expressed as vertical uplift located on. or in close proximity to the Shoreline fault. The newly acquired multibeam echosounder (MBES) high resolution bathymetry data. however. show no evidence of any vertical fault slip on the Shoreline fault (Chapter 12, Figure 6-28). Hence, along this section of the inferred SLRF, where the highest vertical fault slip rates are predicted as indicated by the uplifted terraces, the Hamilton model is not consistent with observations. Rather, the relatively straight trace and a level marine shelf strongly suggests that the Shoreline fault is a nearly vertical strike-slip fault. Implications of Seismic Imaging on the SLRF Near-surface faults can be found along the length of much of the proposed the SLRF but do not support the model of a major thrust fault. New high-resolution offshore IPRP Report No. 8, Page 9 seismic data from the Point Buchon area. where the proposed SLRF diverges from the Shoreline fault, confirm the existence of faults shown in Figure 6-21. Along the central portion of the Shoreline fault the SLRF is coincident with the Shoreline fault. In San Luis Obispo Bay, seismic reflection data also confirms the existence of near surface faults. These surface fault traces, however, have been explained in existing models that interpret the Shoreline fault as a near vertical strike-slip fault, secondary eastern splays along its northernmost reach off of Point Buchon, and a series of strike-slip and reverse fault crossing San Luis Obispo Bay. Although surface faults recognized to date appear to be consistent with strike-slip faulting on the Shoreline fault, rather than thrusting on the SLRF, the possibility of thrust faults in the subsurface is not ruled out by on-land seismic survey data. The interpretation of the ONSIP data is far from unique and allows one to interpret a low angle reverse fault at the proposed location, contrary to what is stated in the CCCSIP report (p.70 Figure 6-54). The CCCSIP interpretation criteria are not clearly defined and do not appear consistent in terms of selections made when seismic reflections are truncated. Does Seismicity Support the Existence of the SLRF? Seismicity can be correlated with active faults; however, many active faults have little to no seismicity during the interseismic period. Further complicating the matter of using seismicity to characterize faults is the observation that microseismicity often occurs in a large volume surrounding the fault rather than on a localized fault plane. Despite these complications, the Shoreline fault was discovered by Hardebeck (2010, 2013) based on a seismicity trend and later confirmed by MBES surveys. The assertion by Dr. Hamilton that seismicity beneath the Irish Hills shows an alignment that indicates the SLRF location and activity at depth is not confirmed by the more rigorous seismicity analysis performed by Hardebeck (2010, 2013. 2014a. 2014b). Hardebeck has shown convincingly that these data do not allow a unique interpretation and clearly do not strongly favor any Irish Hills uplift model. However, as previously implied, the interpretation of microseismicity has clear limitations in mapping faults and in this case also cannot be used to rule out the existence of the proposed SLRF. Conclusions Although specific details of the Hamilton SLRF Irish Hills uplift model are inconsistent with several observations, the overall model that explains the uplift of the Irish Hills via a northward-dipping fault underlying the Irish Hills is a viable alternative model given the uncertainties in the existing data sets. As presented by Dr. Steve Thompson at the November 17, 2014 IPRP meeting, the SSHAC process is considering an alternative model that includes northeast-dipping thrust faults to explain the uplift of the Irish Hills which largely encompasses the hazard implications of the SLRF model. IPRP Report No. 8, Page 10 Diablo Cove Fault The Diablo Cove fault has been proposed by Dr. Hamilton as presenting a surface rupture hazard to DCPP. The basis for this proposed fault consists of on-and offshore bedrock mapping (Figure 6-3. 6-4. 6-5. 6-8. 6-9.6-10). The mapped faulting has been shown to be discontinuous (Figure 6-6. 6-17, 6-18) and limited in extent. Specifically, there are four locations where faulting was observed during the original DCPP construction between 1966 and 1973 (Figure 6-5, 6-6, 6-9): 1.) In the sea cliff south of the outlet of Diablo Creek (Figure 6-8, 6-10); 2.) In the turbine building foundation excavation; 3.) In the Unit 1 containment structure excavation; and 4.) In a road cut for the switchyard access road east of the DCPP power block. At the turbine building the faulting consists of a zone of faulting extending 70 m in length. Under the Unit 1 containment structure the faulting consists of two discontinuous zones of faulting 10 to 20 m in length. Between these two areas the bedrock was continuously exposed and there is a 50 m-long area where no faulting in the bedrock was observed. Perhaps the most significant exposure of the Diablo Cove fault exists in the sea cliff and was described in detail by Jahns (1966, 67a, 67b). The faulting was observed in thinly bedded sandstone originally classified as Tertiary-age Monterrey Formation (Jahns, 1967b), and later reclassified as Obispo Formation (Hall, 1973). Jahns noted that the fault planes in the sea cliff and on the adjacent modern wave cut platform project eastward north of the DCPP site. Figs. 6-3, and 6-4 show this fault zone to strike N55°-600E with a steep dip to the north. The original investigation by Jahns ( 1966) notes: "None of the faults observed in the mapped area extends upward from the bedrock section into the overlying terrace deposits, nor have any of the wave-cut benches beneath these deposits been offset by such faults. Since the original investigation and additional studies. this key observation has never been disputed. The age of this marine terrace is firmly established at 120 ka by correlation and nearby directly-dated U-series dating with a back edge at an elevation of 30-32 m (Hanson et al, 1994 ). No support for Dr. Hamilton's age assertion of 80-105 ka has been provided. Furthermore Jahns (1967b) reasonably states that the maximum age of faulting is millions of years. The discontinuous, minor faulting, with on the order of a few meters of total offset has been interpreted by the CCCSIP authors as most likely related to contractional deformation and folding (Figure 6-17), and as such could be late Miocene to Pliocene in age (Luyendyk, 1991 ). Dr. Hamilton provides a cross section that extrapolates the Diablo Cove fault to seismogenic depths below 4 km and attempts to correlate the location with m icroseismicity (Figure 6-12 ). No basis for th is correlation can be found, as the IPRP Report No. 8, Page 11 seismicity appears almost randomly distributed and provides little basis for any preferred fault selection. We refer to rigorous microseismicity analyses by Hardebeck (2010. 2013, 2014a, 2014b), who quantifies a wide range of possible fault orientations. The CCCSIP report makes the reasonable point that simple scaling relationships makes it unlikely that these short, discontinuous near-surface faults, with minor meter-scale displacements can reasonably be extended to depths of kilometers, where seismogenic processes occur. Offshore Dr. Hamilton has mapped the Diablo Cove fault extending to the Shoreline fault on the basis of interpreted bedding disruptions observed in the Kelpfly MBES image (Figure 6-4, 6-11 ). The CCCSIP authors appear to have optimized the MBES imagery to assess NW trends of faults (Figure 6-8, 6-9), and they can only identify a possible lineament that does not extend continuously to the Shoreline fault, but rather is cut by a more northerly trending "Headland fault" (Figure 6-18). Conclusions Based on the characterization of the minor faulting activity as older than 120 thousand years and very possibly in the millions-at-years age range, we find that the CCCSIP has reasonably assessed the Diablo Cove fault as not presenting a seismic hazard in terms of surface faulting or increased ground motions at DCPP. IPRP Report No. 8, Page 12 STATE OF CALIFORNIA EDMUND G. BROWN JR .. GOVERNOR Independent Peer Review Panel A 1'1U{;lrv*a1f*e-n,,cy pa-11/e'b of:J*ev,s-*m;w JfJect/a-bvJf:J' l!/J't'a.C-lt/.f*fi,e,d-b-y t'lw/ Ca,,/,Vf'o-rwvw ltt'vbU-U>.,,f* Ct>-1*1vnvt/J-rio-w CALIFORNIA GEOLOGICAL SURVEY, CALIFORNIA COASTAL COMMISSION CALIFORNIA GOVERNOR'S OFFICE OF EMERGENCY SERVICES CALIFORNIA PUBLIC UTILITIES COMMISSION, CALIFORNIA ENERGY COMMISSION CALIFORNIA SEISMIC SAFETY COMMISSION, COUNTY OF SAN LUIS OBISPO IPRP Report No. 6, August 12, 2013 Site shear wave velocity at Diablo Canyon: summary of available data and comments on analysis by PG&E for Diablo Canyon Power Plant seismic hazard studies BACKGROUND In 2006, the California Legislature enacted Assembly Bill (AB) 1632, which was codified as Public Resources Code Section 25303. AB 1632 directed the California Energy Commission (CEC) to assess the potential vulnerability of California's largest baseload power plants, which includes Diablo Canyon Power Plant (DCPP), to a major disruption due to a major seismic event and other issues. In response to AB 1632, in November 2008 the CEC issued its findings and recommendations in its AB 1632 Report, which was part of its 2008 Integrated Energy Policy Report Update. In Pacific Gas and Electric Company's (PG&E) 2007 General Rate Case decision D.07-03-044, the California Public Utilities Commission (CPUC) directed PG&E to address and incorporate the recommendations from the AB 1632 Report into its feasibility study to extend the operating licenses of its Diablo Canyon Units 1 and 2 for an additional 20 years. In November 2009, PG&E submitted its formal application with the Nuclear Regulatory Commission (NRC) to extend the licenses of DCPP Units 1 and 2. In 2010 PG&E filed for cost recovery with the CPUC for expenditures associated with the enhanced seismic studies recommended by the CEC's AB 1632 Report. The motions for cost recovery were subsequently approved in 2010 and 2011. CPUC Decision D.10-08-003. issued on August 16, 2010, established that the CPUC would convene its own Independent Peer Review Panel (IPRP) and invite the CEC, the California Geological Survey (CGS), the California Coastal Commission, and the California Seismic Safety Commission to participate on the panel. Under the auspices of the CPUC, the IPRP is conducting an independent review of PG&E's seismic studies including independently reviewing and commenting on PG&E's study plans and the findings of the studies.

The comprehensiveness. completeness, and timeliness of these studies will be critical to the CPUC's ability to assess the cost-effectiveness of Diablo Canyon's proposed license renewal. As noted in the CEC's AB 1632 Report, a major disruption because of an earthquake or plant aging could result in a shutdown of several months or even cause the retirement of one or more of the plants' reactors. A long-term plant shutdown would have economic, environmental and reliability implications for California ratepayers. In contrast to previous reports of the IPRP, which commented on studies by PG&E to investigate potential earthquake sources near Diablo Canyon, this report focuses on the site amplification factor -an important factor in the calculation of ground motion from any earthquake. The report summarizes data that are available to constrain the site amplification factor and uncertainties in its value, and then provides comments on analyses performed by PG&E using their preferred method of considering that parameter. We chose to focus on site amplification at the Diablo Canyon site because "site conditions" modify earthquake shaking from any earthquake. In sensitivity studies by CGS for the IPRP, site amplification factor has a large effect on calculated seismic shaking potential at DCPP. INTRODUCTION Estimated ground motion hazards can be altered significantly by site conditions, and different methods used to incorporate the effects of site conditions often result in different ground motion estimates. Three approaches have been used in engineering practice to incorporate the effects of site conditions on estimated ground motion hazards: 1. Scaling based on soil classifications, for example, the National Earthquake Hazards Reduction Program (NEHRP) site classifications used in building codes; 2. Using ground motion prediction equations (GMPEs) that incorporate the average shear wave velocity of the uppermost 30 meters of a site (Vs30) as an approximation for site condition; and 3. Site response analyses using near surface site-specific or generic soil profiles. The NEHRP scaling approach is simple, conservative. and often used only for an approximate estimation of design ground motion values. In most modern GMPEs, such as the Next Generation Attenuation (NGA) relations, V530 is treated as an independent variable along with earthquake magnitude, site-to-source distance, etc.; and ground motions for a specific site are calculated by entering the site-specific Vs30 value directly in the GMPEs. For sites with Vs30 values outside the data range that adequately constrains the GMPEs, however, direct use of Vs30 in GMPEs may not be appropriate. In such cases, other methodologies, such as site response analysis, are utilized. PG&E uses a new method to incorporate site effects based on recorded ground motions at Diablo Canyon. A site amplification term has been developed based on ground motion residuals at the site from two locally recorded earthquakes. Uncertainty in site IPRP Report 6, Page 2 amplification is based on the epistemic uncertainty due to systematic differences in the site amplification between sites with the same Vs30 in a single station sigma approach. Compared to traditional approaches, the PG&E method resulted in lower ground motion hazard estimates, particularly in the spectral period range important to DCPP (3.5 to 8 Hz), as reported in the Shoreline Fault Report (SFR) (PG&E 2011 a). The PG&E method is based on state-of-the-art research and is technically sound. However, additional data, clarification, and documentation are required to justify the applicability of the method to the DCPP site. In this memo, we summarize PG&E's determination of the mean site Vs30 value and discuss variability in near surface shear wave velocity (Vs) illustrated in PG&E data. We demonstrate that a lower Vs30 value is more consistent with other soft rock sites in California and is within the range of uncertainty observed at the DCPP site. A lower V830 brings the estimated ground motion hazards beyond the original design level when used in typical, state-of-the-practice seismic hazard analysis using GMPE's. Given the significant effects of site Vs30 value and uncertainty in near surface Vs on ground motion estimation using a traditional approach, we suggest that PG&E present an evaluation on whether the large uncertainty in near surface Vs is captured adequately in their site amplification approach that is based on two historical earthquakes and the single station sigma concept. DCPP SITE Vs30 VALUES PG&E determined that the DCPP power block foundation has a mean Vs30 value of approximately 1,200 m/s, corresponding to a hard-rock site. This mean Vs30 value was determined based on downhole velocity surveys in four deep boreholes (Figure 1) near the power block conducted in 1978 as part of the PG&E Long Term Seismic Program (L TSP) and two velocity profiles measured in 1998 at the Independent Spent Fuel Storage Installation (ISFSI) site as part of the ISFSI site characterization (Figure 2). The ISFSI site is located approximately 400 m away from IPRP Report 6, Page 3 0 *CO 300ft SCALE. Bo11r.g NU ... locOllonw El**aliO<l Stre pla:: a:-.4 borthofo of *he ir .... es:jgslilm.,o; (rt'f"1rGncc I ():t Ta.tie Figure 1. Location of four downhole velocity survey boreholes near the power block (provided by PG&E). / ,' / g:1: Q "" <!< po>1b *

• llu'. *um b11> 1* ,._., Or * * *w1um **ll*hh i, H1 * * **f\"'
• 1lluv1.1I t,*n (Jh Qt:f Onl;* s,u(tclal *:lepos*:S qret1h:r th.l r. 1hour -r ..... , 11*, r l <, hrw*.n j Op.. . r:l:':')tfJ<-:ont-<.fJllu*. ,ti ! Opt:i1: 1 v* v .. :. ***Ul ,, *. 1.. :nu:i.u .. M1.1. **u .. : :l1.1h.1*.** 111cm*.h'" ,,11-. .. lnd M,* *nb.:*1 tut U I Ill I .. .. ,h tnn-,tf>d ... uu.ht1:**.o:' llll:'*h.nn ,,*: Puc:k h-:ld'"'d Figure 2. Location of ISFSI site (provided by PG&E). The two ISFSI boreholes were located in the highlighted area. the power block. Vs30 values were determined to be 1,212 m/s, 1,228 m/s, and 1,215 m/s for the mean 1978 profile near the power block and the two 1998 profiles at the ISFSI site. PG&E noted that the accuracy of the computed Vs30 values for the ISFSI site is a few percent because the digitization of the ISFSI profiles has a limited accuracy of a few percent. The accuracy of the 1978 profile at the power block is not determined. PG&E also noted that the Vs30 value of 1,200 mis is at the power block embedment depth of 32.4 ft (or approximately 10 m) determined by the lower range of the original surface elevation of 85 ft (from mean sea level) minus the power block foundation elevation of 52.6 ft. We note that according to Figure 5-3 in the DCPP LTSP report (PG&E, 1991) (reproduced as Figure 3 in this memorandum), 52.6 ft represents the deepest part of the power block foundation. A considerable portion of the Turbine Building and Containment Structure is located less than 10 m from the surface and the Auxiliary Building is approximately at the level of the down-slope surface (i.e., elevation of 85 ft). A conservative measure would assume that these structures are located on the IPRP Report 6, Page 4

<;;_ Rnad Turt>ine AuilCing --EL_8.5':..0" * . ---*-l 1 --ri.,__; EL o*-o* J EL 61'-0 S:r*.Jc:;.;ro Figure 3. Cross section of DCPP (Figure 5-3 in DCPP LTSP report, PG&E, 1991). The dashed curve is the original ground surface. ground surface. Vs30 for the ground surface would be lower than at 10 m depth. PG&E indicated during meetings with IPRP that soil structure interaction (SSI) analysis is used to estimate ground motions at different elevations (or embedment levels), and the SSI analyses will incorporate a range of site-specific Vs profiles. Sfl*ar Wave Velocity (Ip.a In 1000s) 2 3 4 5 7 8 100 g c [II c i 0 I 80 -*--:. 396 rn/$ !.. ........ .... -. i : 1,219m/s I : 60 >-: : 40 .... 20 *20 ,. *40 -*60 -*SO -*10D -*120 --140 -*160 ..... -180 ..... *200 792 ml* : i *--'l : : ............. . f i 731n1/si l ! : : I ! : ! : i j 1,646 m/s i ! B I ! I i i : I !............. . .... .:. ........ . : 1,..219 m/$ EXPlA'IATION -BMttioleA*2 -*-* Bor.hvl* B *******Bo<ehol*C ----Be>retioleD A*2 ! l 1.7S3m/s t : ! ! : c : ! i ! Figure 4. Shear wave velocity profiles from 1978 downhole velocity surveys (provided by PG&E). IPRP Report 6, Page 5 In response to our request for additional information on the Vs measurements near the power block, PG&E provided the I PRP with its response to an NRC request for additional information (RAI) made in January 1989 (Question 19) that included shear wave measurements in the four deep boreholes drilled in 1978 near the power block (provided by Richard Klimczak via email dated April 22, 2013). Figure 4 shows these Vs profiles. Considerable variability in measured Vs is observed in this figure. For example, at mean sea level (zero elevation), the measured Vs varies from 731 m/s to 1,646 m/s, a range of over 900 m/s, over a depth range of 80 24 m). According to PG&E's calculation (Excel spreadsheet file provided by Richard Klimczak via email dated April 22. 2013). Vs30 values from these four boreholes are 981 mis. 1,646 mis, 764 mis and 1,347 mis. The shear-wave velocity profile from borehole "B", however, does not include any measurement from within 80 feet of the surface, so is not appropriate for use in calculating V530. Excluding borehole "B", the mean is 1,031 mis and standard deviation is 295 mis, but even this mean is probably higher than the actual V530 at the site. Borehole "C" includes no velocity measurements within 15 feet of the surface and Borehole "A-2" includes no velocity measurements within 30 feet of the surface. Considering that near-surface weathered rock is almost always lower in velocity than deeper unweathered rock, both the mean velocity and range of velocities in the upper 10 mare probably overestimates. In its response to the NRC RAI, PG&E developed a mean Vs profile and lower and upper bounds based on the four 1978 boreholes. Previous soil-structure interaction analyses using this range of uncertainty in Vs profiles found a significant effect of uncertainty in near surface Vs on soil-structure interaction. This effect may have been underestimated because of overestimates of Vs at shallow depths in the average profile by PG&E. Considering the three usable measured profiles, A-2, C, and D, the mean value at 10 m is approximately 800 mis, considerably below PG&E's mean of 1200 mis. A mean value at 5 mis problematic because only profiles C and D measured velocities at that depth. If A-2 had the same velocity as Cat a depth of 5 m, consistent with the relative weathering described in the borehole logs. the mean velocity at that depth would be about 650 mis. also below PG&E's mean value of 1000 mis. The lower bound profile also appears to be overestimated at all depths because it approximates the measured velocities in borehole C. With only three profiles, it is unlikely that one of them represents the lowest velocity material underlying the plant. Some of the variability seen in the 1978 data may reflect poor quality of the Vs measurements made 35 years ago. Interpretations of that data, however, appear to include unconservative assumptions of velocity in boreholes where no velocity was recorded in the upper parts of the soil profile. Alternative interpretations suggest overall lower velocity of the rock underlying the plant and greater variability of velocity across the plant footprint. A complete consideration of site conditions across the plant footprint requires additional Vs measurements using modern technology to constrain the uncertainty and yield more reliable site Vs values. PG&E relied on the two newer profiles at the ISFSI site to justify the use of a mean Vs30 value of 1,200 mis because both the ISFSI and the power block are located on the same geologic unit (the Miocene Obispo Formation, which is composed of tuffaceous and diatomaceous sandstone and silty sandstone). Although the Vs30 values derived from the two Vs profiles at the ISFSI site (1,228 m/s and 1,215 mis) are consistent with a Vs30 of 1,200 mis, these two profiles do not give consistent Vs measurements at given depths. Considerable variability exists at some depth ranges (see Figure 5). Vs30 values from these two boreholes would be 993 mis and 1,214 mis, respectively, if calculated IPRP Report 6, Page 6 from the surface instead offrom 10 m depth. While these two measurements support the high velocity measured in borehole Din 1978, they do not help constrain the lower bound or range of velocity at the plant site. Geological formations elsewhere in California that are similar to the formations at the power block and the ISFSI site show considerable variation in Vs30 values. Tertiary sandstone measured in California have an average Vs30 of 555 m/s and Tertiary volcanic rocks have an average Vs30 of 609 mis (Wills and Clahan, 2006). Since the Obispo Formation at the power plant is relatively well indurated sandstone, above average Vs30 values are expected, but 1 ,200 mis is higher than the expected range of values for this type of rock. Additional Vs measurements near the power block would give better assurance that variability in site Vs30 value as well as near surface Vs profile is adequately captured and the values used in hazard analysis are well constrained, particularly because the rock at the DCPP site is both faulted and folded, leading to greater variability. IPRP Report 6, Page 7 0 10 20 -E -..c 30 -35 0 I I I Shear Wave Velocity (m/s) 500 1000 1500

• I I I I '-1 I I I I I I I I I f I I I I t Mean Profile ---Lower Bound --Upper Bound -ISFSl-1 ISFSl-2 -50 2000 Figure 5. Mean shear wave velocity profile and uncertainty from 1978 downhole velocity surveys and the simplified shear wave velocity profiles from ISFSI borings (plotted using data provided by PG&E).

PG&E APPROACH FOR HARD-ROCK SITE EFFECTS PG&E used an indirect approach to account for hard rock effects. The PG&E approach includes: (1) using the NGA relations to calculate median ground motions and associated standard deviations for a generic "firm rock" condition with Vs30 of 760 mis, and (2) using amplification factors derived by Silva (2008) from generic site response analyses for hard-rock sites to adjust the NGA-predicted median (for a Vs30 of 760 mis) to a generic hard-rock condition (Vs30 of 1,200 mis). PG&E stated that the reason it did not use NGAs to calculate ground motion for Vs30 of 1,200 mis is because this Vs30 value is outside of the range of Vs30 that is well constrained by the empirical data used to derive the NGAs. Silva (2008) derived amplification factors relative to a Vs30 of 1, 100 m/s for 64 cases with different velocity profiles, including rock profiles. PG&E chose two of Silva's 64 cases (Cases 61 and 64 with V530 of 760 m/s and 3, 150 mis, respectively) as relevant to the DCPP site based on similarity in kappa (K) values (approximately 0.04 second, PG&E determined that K for the DCPP site is 0.042 second). It was determined from these two cases that the site amplification is close to a linear function with site Vs30. Therefore, the amplification factors from Vs30 of 760 m/s to 1, 100 m/s were used to extrapolate to the DCPP site ( Vs30 of 1,200 mis). The raw values were smoothed and are shown in Figure 6-6 of the SFR (PG&E, 2011a). Values of hard rock amplification factors (a1) are listed in Table 6-5 of SFR. As indicated in the SFR, K of 0.04 second is the justification for using the Silva (2008) generic amplification factors for the DCPP site. However, in the NGA dataset, K of about 0.04 second is found for generic soft-rock sites in California. For hard-rock sites, the K values can be much smaller (0.01 -0.02 second). There is an inconsistency in the DCPP site condition indicated by the site-specific Vs30 value of 1,200 m/s (hard rock) and by the site-specific K value of 0.042 second (soft rock). This inconsistency makes application of the Silva (2008) scaling factors questionable. Furthermore, the K value for the DCPP site isn't well constrained, as discussed in the next section. However, the Silva (2008) scaling factors were used mainly to compute event-corrected ground motion residuals to derive site-specific site amplification terms using the new site amplification approach, as discussed in a later section. KAPPA AND DCPP KAPPA VALUE K is a seismological parameter that reflects the observable high frequency decay of Fourier amplitude spectra in ground-motion recordings. Although the Fourier amplitude spectra of recorded ground motions are usually jagged, their characteristic shapes can be seen more easily when they are plotted on logarithmic scales. Fourier acceleration amplitudes tend to be largest over an intermediate range of frequencies bounded by the corner frequency on the low side and the cutoff frequency on the high side. The corner frequency is shown theoretically (Brune, 1970) to be inversely proportional to the cube IPRP Report 6, Page 8 root of the seismic moment. Therefore, smaller magnitudes have higher corner frequencies and large earthquakes produce greater low-frequency motions than do smaller earthquakes. Anderson and Hough ( 1984) characterized the shape of the spectrum at high frequencies as exponentially decaying, given by: a(f) = A0 exp(-rrKf) for f > fE where fE is a frequency above which the decay is approximately linear on a plot of log amplitude against linear frequency, Ao is Fourier amplitude, which is dependent on source and propagation path, and K controls the rate of amplitude fall-off with frequency. Although K is accepted as a parameter representing the behavior of Fourier spectra at high frequencies, the mechanism causing this observed fall-off is under debate. Hanks (1982) suggested site effects in near-surface materials; Papageorgiou and Aki (1983) prefer a source-dependency (source does not produce high frequencies due to fault nonelasticity); Anderson and Hough (1984) found that K increases with epicentral distance; and Tsai and Chen (2000) suggested a combined effect of source, distance, and site, with the distance being the least significant of the three. To obtain a more meaningful parameter, the distance dependency can be eliminated by extrapolating the K(r) trend to zero epicentral distance (r = 0). The intercept, Ko, is believed to denote the site attenuation a few kilometers immediately beneath the station (Hough et al., 1988). Ko is a commonly applied high-frequency filter parameter. Silva and Darragh (1995) show that near-source attenuation modeled through K mainly influences response spectra content for frequencies greater than about 5-10 Hz. Average Ko value is 0.037 second for western North America and 0.008 second for eastern North America, demonstrating the difference in rock spectral content in eastern and western North America. Houtte et al. (2011) observed predominant influences of superficial layers of soil on Ko. Although small, a source component of Ko is clearly observable. Ko is often calculated from ground motion recordings as the fitted slope of Fourier amplitude spectra. It can also be estimated from site material properties. An alternate approach was used to determine the K value at the DCPP site. PG&E (2011 a) used the stochastic point source model of Boore (2000) with a K value of 0.042 second and stress drop of 120 bars to simulate ground motions of a 2003 M3.4 Deer Canyon earthquake at a hypocentral distance of 7.8 km. Because the resulting response spectrum compares well with the average horizontal spectrum of the free-field recordings at the DCPP from the 2003 M3.4 Deer Canyon earthquake, K value for the DCPP site is said to be 0.042 second. This K value is not well constrained. It is not clear why K isn't calculated by fitting the Fourier spectrum of the recorded motions or estimated from material properties as noted above. IPRP Report 6, Page 9 PG&E APPROACH TO SITE-SPECIFIC AMPLIFICATION In the SFR, PG&E derives site-specific amplification factors based on recorded ground motion data from two earthquakes: the 2003 M6.5 San Simeon earthquake and the 2004 M6.0 Parkfield earthquake. Site-specific amplification factors are derived for each earthquake event through the following procedure: (1) Determine event terms for a suite of frequencies. For each frequency, the event term is the average of residuals event residuals) from recordings within a chosen distance range that approximately centers on the rupture distance at the DCPP site. The event term is meant to remove source-specific effects; (2) GMPEs are used to calculate median ground motions from the earthquake for the DCPP site rupture distance and a Vs30 of 760 mis. The predicted median ground motions are corrected by the event term from step 1 and scaled to a generic free-field site condition with V830 of 1.100 mis (reference V830), representative of surface V830 value at the DCPP site, using Silva (2008) scaling factors; (3) The average median spectra from all GMPEs (from step 2, event term corrected and Vs30 scaled) are compared with the observed free-field ground motion spectrum at the DCPP site and the differences (i.e., event-term corrected residuals) represent specific amplification compared to a generic site with the reference Vs30 value. Finally, site-specific amplification factors are determined as the mean residuals from the two available earthquakes (averaged period by period and smoothed over a period range). The values of the smoothed mean residuals (i.e., site-specific amplification factors, a2, for reference Vs30 of 1, 100 mis) are listed in Table 6-7 of SFR. Because a2 in Table 6-7 of SFR is derived for reference Vs30 of 1, 100 mis (DCPP surface condition), the overall site amplification factor for NGA medians calculated with Vs30 of 760 mis to DCPP surface condition is the sum of a2 in Table 6-7 plus a1 for Vs30 of 1, 100 mis in Table 6-5 of SFR. The overall amplification factor for NGA medians calculated with Vs30 of 760 mis to the DCPP power block foundation is approximated as a2 in Table 6-7 plus a1 for Vs30 of 1.200 m/s in Table 6-7 of SFR. Note that a1 and a2 in these SFR tables are in natural log units. The overall amplification factor in linear units is the exponential of a1+a2 and is reproduced in Figure 6 (solid curve) of this report. IPRP Report 6, Page 10 2 1.8 -1.6 Ill ' E 0 1.4 U) ,.... 0 .. Qj > 1.2 .i Qj 1 ... -... 0 IQ 0.8 I.I. c 0 .B o.6 Qj ... .. 0 u 0.4 0.2 0 0.1 \ --exp(site_amp) \ ---PG&E+ lo ---PG&E-lo ' 1, I ' ', ' --PG&E+ 2o --PG&E-2o ' . \ ' , ' ,, ', \ --NRC average --Silva Generic 1 ', \ \\ ,, \ ____ ,, ' ' , ' -------' , __ ---------10 100 Frequency (Hz) Figure 6. Site-specific amplification relative to Vs30 of 760 m/s and associated uncertainty (reproduced based on presentation by Norm Abrahamson on June 6, 2013). exp(site_amp) is the exponential of PG&E site amplification term and is used to scale GMPE median predictions, and o is standard deviation applied to PG&E site amplification term. The uncertainty in the mean residual value (i.e., epistemic uncertainty in site-specific amplification factor) has a variance of af25(T)/N, where N is number of observations (i.e., earthquake events) and af25(T), termed site-to-site uncertainty in the single station sigma approach, is the variance of the epistemic uncertainty due to systematic differences in the site amplification between sites with the same Vs30 value. as2s(n is calculated as: af25(T) = Ja2(T,M) -affs(T,M) where a2(T, M) is the standard deviation given by GMPEs. It is a function of earthquake magnitude, M, and is often given as discrete values for a series of spectral periods (n. a55(T, M) is single station sigma, representing a reduced standard deviation for single sites. In the SFR, PG&E used a preliminary model for single station sigma derived for the NGA models (BCHydro, 2010): IPRP Report 6, Page 11 a55(T, M) = (0.87 + 0.0037 ln(T))a(T, M) In the SFR, a525(T) is averaged over M6, M6.5, and M7 to capture standard deviation for the magnitudes relevant for the DCPP site. It also is averaged over the five NGA models used for DCPP ground motion hazard studies. N for the DCPP site is listed in the last column in Table 6-7 of the SFR. In the SFR, this epistemic uncertainty on site amplification is combined with ground motion aleatory uncertainty in the ground motion hazard calculation for computational efficiency. PG&E indicated that in future analyses this epistemic uncertainty will be accounted for using the standard logic-tree approach for epistemic uncertainties, and the range of +/-2 standard deviations will be considered. This uncertainty range also is reproduced in Figure 6 of this report for reference. In the single station sigma approach employed in SFR, ground motion hazards are calculated by integrating a lognormal distribution with single station sigma as the standard deviation instead of the standard deviation from GMPEs. NRC REVIEW OF PG&E SITE EFFECTS In its review of PG&E's SFR, the Nuclear Regulatory Commission (NRC, 2012) concluded that PG&E's site-specific Vs30 value of 1,200 mis is reasonable. This conclusion is based on evaluation of the same three velocity profiles used by PG&E. The NRC agreed that using such a high Vs30 value with the NGAs would not be appropriate. The NRC staff considered PG&E's scaling approach for incorporating site effects appropriate. However, it questioned the applicability of the specific scaling factors and developed an independent set of site correction factors based in its independent site response analyses using PG&E's near surface Vs profile. The NRC site correction factors are plotted in Figure 6 (red curve) for comparison. Also plotted in Figure 6 is Silva's (2008) factor (i.e., a1) for scaling from a generic site with Vs30 of 760 m/s to a generic hard rock site with Vs30 of 1,200 m/s. This figure shows that within the period range important to DCPP, the NRC correction factor is similar to the Silva amplification factor for generic hard rock sites, and DCPP site-specific amplification factor is lower than both the NRC and Silva factors for frequency greater than 4 Hz. IPRP Report 6, Page 12 EFFECTS OF SITE AMPLIFICATION FACTORS ON ESTIMATED DCPP GROUND MOTION HAZARDS To demonstrate the significant effect of site amplification on estimated ground motion hazards at the DCPP site, we reproduced PG&E's deterministic ground motions (dashed curves in Figure 7) for the four main fault sources (the Hosgri fault, Los Osos fault, Shoreline fault, and San Luis Bay fault) and then did the same analysis for other site conditions. For dipping faults, the cases with the lowest estimated dip angles were analyzed. Table 1 lists input parameters for these deterministic calculations. These calculations used the same four NGAs used by PG&E: Boore and Atkinson (2008), Campbell and Bozorgnia (2008), Chiou and Youngs (2008), and Abrahamson and Silva (2008). Figure 7 compares PG&E 84th percentile deterministic ground motions (dashed curves) with those from three sensitivity cases (solid curves in Figures 7a, 7b, and 7c). The PG&E 1991 L TSP/SSER 34, the 1977 HE (Hosgri Earthquake) design spectrum, and the frequency range important to DCPP structures (marked by vertical dark grey lines) are plotted for reference. The PG&E calculation uses PG&E site-specific amplification factors derived from ground motion residuals, epistemic uncertainty in specific amplification factors, and single station sigma. The three sensitivity cases are: (i) a generic site with Vs30 of 1,200 m/s (scaled from GM PE-predicted median for Vs30 of 760 mis using Silva scaling factors, single station sigma); (ii) a generic site with Vs30 of 760 mis (GMPE-predicted median without scaling) using single station sigma; and (iii) a generic site with Vs30 of 760 mis (GMPE-predicted median without scaling) using sigma from GMPEs (i.e., ergotic sigma). This figure shows significant effects of site condition Table 1. PG&E selected deterministic earthquake scenarios (modified from Table 6-8 of the Shoreline Fault Report) Rupture Distance (km)2 Fault Source Magnitude1 Dip (0) Sense of slip3 RR up RJB Rx Hosgri 7.1 80 4.9 2.3 4.9 Strike Slip Los Osos 6.8 45 7.6 0.0 9.9 Reverse/Oblique Shoreline 6.5 90 0.6 0.6 0.6 Strike Slip San Luis Bay 6.3 50 1.9 0.0 2.5 Reverse l ,m .. 90 fractlle of the mean charactenst1c magnitude d1stnbut1on for non-linked cases from source characterization logic tree (see Figure 6-17, PG&E, 2011a) 2RJe is closest horizontal distance to the surface projection of the rupture plane, RRup is closest distance to the rupture plane, and Rx is horizontal distance from the top edge of the rupture, measured perpendicular to the fault strike (it is positive over the hanging wall and negative over the footwall) 3DCPP site is on the hanging wall of Hosgri, Los Osos, and San Luis Bay faults. IPRP Report 6, Page 13 on deterministic ground motions. Compared to a generic rock site with Vs30 of 1,200 m/s, the PG&E site-specific amplification factors shift peak spectral response toward lower frequency. They also lead to slightly lower peak spectral response for all four scenarios (Figure 7a). Compared to a generic site with V530 of 760 m/s, the PG&E site specific ground motions are significantly lower, except for frequencies lower than approximately 2 Hz (Figures 7b and 7c). Comparison of these figures also shows that reducing the aleatory uncertainty in ground motion from GMPE sigma to single station sigma reduces predicted ground motion amplitudes across the spectrum (compare the set of solid curves in Figure 7b with that in Figure 7c). These two figures also show that if DCPP site had a Vs30 value of 760 m/s rather than 1,200 m/s, and if the site behaves more like an average site in ground motion amplification, some deterministic spectra would exceed the 1991 LTSP spectrum. 2.5 2.0 -c .2 1.5 ... QJ "ai u 1.0 ... u QJ a. V'l 0.5 0.0 0.1 -Hosgri 1200o_ss -Los Osos 1200 o ss Shoreline 1200 o_ss -San Luis Bay 1200 o_ss ---Hosgri PG&E ---Los Osos PG&E Shoreline PG&E ---San Luis Bay PG&E ---1977 Spectrum -1991 LTSP Spectrum a 1.0 10.0 100.0 Frequency (Hz) Figure 7. Comparison of deterministic ground motion spectra from PG&E for the DCPP site (dashed color curves; using site amplification term, its uncertainty, and single station sigma) with deterministic spectra of three sensitivity cases (solid curves): (i) a generic site with V530 of 1,200 m/s and single station sigma (Figure 7a); (ii) a generic site with Vs30 of 760 m/s and single station sigma (Figure 7b); and (iii) a generic site with V530 of 760 m/s and sigma from GMPEs (ergotic sigma, Figure 7c). The PG&E 1991 LTSP/SSER 34, the 1977 HE (Hosgri Earthquake) design spectrum, and the frequency range important to DCPP (marked by vertical dark grey lines) are also plotted for reference. (Continued) IPRP Report 6, Page 14 2.5 2.0 s s i 1.5 ... <U .., c( 1.0 ti <U Q. VI 0.5 0.0 2.5 2.0 s s i 1.5 ... <U Qi .., 1.0 ti <U a. VI 0.5 0.0 0.1 0.1 -Hosgri 760 o_ss --Los Osos 760 o ss Shoreline 760 o_ss --San Luis Bay 760 o_ss ---Hosgri PG&E ---LosOsos PG&E Shoreline PG&E ---San Luis Bay PG&E ---1977 Spectrum -1991 LTSP Spectrum b 1.0 --Hosgri 760 Ergotic -Los Osos 760 E rgotic Shoreline 760 Ergotic --San Luis Bay760 Ergotic ---Hosgri PG&E ---Los Osos PG&E Shoreline PG&E ---San Luis Bay PG&E ---1977 Spectrum -1991 LTSP Spectrum c 1.0 Figure 7. Continued. IPRP Report 6, Page 15 Frequency (Hz) Frequency (Hz) 10.0 100.0 ' ,, ,, ,, ,, ' , ', ,,,,, 10.0 ', , ___ -. ........... ' *-' -----100.0 We also calculated probabilistic ground motions using PG&E's probabilistic seismic hazard analysis codes provided by Norm Abrahamson. The calculations were based on an input file (also provided by Norm Abrahamson) that contains the input parameters and the full logic tree of the PG&E base case. We made changes to the input files in order to look at the sensitivity of estimated probabilistic ground motion hazards to site amp I ification. Figure 8 compares the total hazard curve that we reproduced using the PG&E base case input file provided by Norm Abrahamson without modification (solid red curve, using site-specific amplification term, a V530 of 1200 mis scaling, and single station sigma) with two sensitivity hazard curves: (i) for a generic site with Vs30 of 760 mis (dashed red curve, no scaling, single station sigma); and (ii) for a generic site with Vs30 of 1,200 mis (solid green curve, Silva scaling factor, single station sigma). This figure, once again, shows significant increase in ground motion hazards when PG&E specific amplification factors are not used and as Vs30 value is decreased from 1200 m/s to 760 mis. 1.E-02 1.E-03 l.E-05 l.E-06 0.1 Total Hazard Curves at 5 Hz ..... .......... .... -PG&E base case (site term) ---Vs30= 760 m/s, sigma_ss ........ ',, Vs30 = 1,200 m/s (generic), sigma_SS ',, ' ', ' ' ' Spectral Acceleration (g) ' ' ' ' ' ' ' ' ' ' ' \ \ ' ' \ \ ' \ \ \ \ \ \ \ \ \ \ \ 10 Figure 8. Comparison of the total hazard curve at 5 Hz obtained from PG&E base case input file provided by Norm Abrahamson (used site-specific amplification factor) with hazard curves for generic sites with Vs30 of 760 m/s (GMPE-predicted median without scaling) and 1,200 m/s (using Silva scaling factors), respectively. Single station sigma is used in all cases. IPRP Report 6, Page 16 Sensitivity analysis for probabilistic hazards was conducted by PG&E (2011 b) to address an IPRP request to test the main targets of the onshore and offshore geophysical studies. Probabilistic hazard sensitivities to individual targets are demonstrated by comparing hazard curves in Figures 2 through 11 of PG&E's response to IPRP (PG&E, 2011 b). Sensitivity of the 5 Hz hazard at 2 g ground motion level for different sensitivity cases are summarized and ranked in a "tornado plot" shown in Figure 12 of PG&E (2011 b ). The tornado plot is reproduced in this memorandum as Figure 9 for reference. The x-axis value is the ratio of 5 Hz hazard at 2 g spectral acceleration to the reference hazard of 10-4 (i.e., the approximate base case hazard for 5 Hz at 2 g spectral acceleration level). This figure shows that probabilistic hazard is most sensitive to Hosgri slip rate. Uncertainty in Hosgri slip rate may lead to calculated ground motion hazard that varies by a factor of nearly 2. Hosgri Slip-Rate Hosgri Dip (.J u (J Shoreline Slip-Rate o 0 Hosgri -San Simeon Step-Over c Los Osos Dip 00 0 Los Osos Sense of Slip 0 0 Hosgri & Shoreline Rupture 0 Los Osos Slip-Rate () () Shoreline Segmentation () () Shoreline Southern End 0 0 0.25 0.5 0. 75 1 1.25 , .5 1. 75 2 Sensitiivity Hazard I 1 E-4 (at 2 g) Figure 9. PG&E Summary of hazard sensitivity showing effect on 5 Hz hazard for a reference hazard level of 104 (after PG&E, 2011b) IPRP Report 6, Page 17 We constructed a similar "tornado plot" (Figure 10) to put the effect of site condition in the same perspective as source parameters studied by PG&E (2011b). In Figure 10, the horizontal axis is the ratio of 5 Hz sensitivity case hazard to base-case hazard at spectral acceleration of 2g. PG&E base case used site-specific amplification term. its uncertainty, and single station sigma. All other cases used unscaled GMPE medians with Vs30 values indicated in the figure. This figure shows that changing site condition from PG&E characterized DCPP site to a generic site with Vs30 of 760 m/s increases the hazard by more than a factor of 3 (compare hazards for PG&E base case and the 760 m/s case). Changing site condition from PG&E base case to a generic site with Vs300f 1000 m/s increases hazard by a factor of 2. V530= 760 m/s GMPEs 1000 m/s GMPEs V530= 1200 m/s GMPEs PG&E Bse Case 0 0 0 0 0 1 2 3 4 Ratio of Sensitivity Hazard vs. Base-Case Hazard at 2 g Figure 10. Sensitivity shown as the ratio of sensitivity case hazard to PG&E base-case hazard for 5 Hz spectral acceleration at 2 g. IPRP Report 6, Page 18 The fragility used for DCPP is based on the spectral acceleration averaged over the frequency band of 3 -8.5 Hz. Figure 11 shows the significant effect of site condition on this ground motion parameter. Also plotted on this figure is the 1988 L TSP hazard curve for comparison. This figure shows that changing site condition from PG&E characterized DCPP site to a generic site with Vs30 of 760 m/s brings the average ground motion over the frequency band of 3-8.5 Hz above the 1988 L TSP curve (PG&E, 1988) for acceleration greater than about 1.5 g (i.e., hazard level of approximately ?x 10-4 or return period of approximately 1,428 years). <: Cl/ ..... cu 1.E-02 1.E-03 1.E-04 c: cu "'C Cl/ x UJ cu => c: c: <( 1.E-05 1.E-06 0 0.5 1 -Single-Station o. 1200 m/s Single-Station o, 760 m/s -1988LTSP 1.5 2 2.5 3 3.5 Spectral Acceleration (g) Figure 11. Comparison of mean hazard curve for 3-8.5 Hz for Vs30 of 760 m/s with PG&E base case and the 1988 LTSP curves. IPRP Report 6, Page 19 4 DISCUSSION AND RECOMMENDATIONS In summary, PG&E determined that the Vs30 value for DCPP Site is 1,200 mis, similar to a hard rock site. Because NGAs are not well constrained for Vs30 greater than approximately 1,000 mis. NGAs were used to calculate median ground motions for a generic "firm rock" site with V530 of 760 mis. Empirical site-specific amplification terms were developed as mean residuals (event corrected) of ground motions recorded at the site from two locally recorded earthquakes. Site-specific amplification terms (relative to V830 of 760 mis) were then used to scale NGA-predicted median ground motions to the DCPP site condition. Uncertainty in site-specific amplification is characterized by station-to-station uncertainty in the single station sigma concept and is combined with single station sigma and integrated in hazard calculations for computational efficiency. In the frequency range important to DCPP, PG&E site-specific amplification factors are significantly lower than scaling factors for generic sites (Silva. 2008). NRC factors derived from site-response analysis for the DCPP site as part of their independent analysis. and conservative factors in current California and building codes for conventional and critical facilities. So far, PG&E has not captured epistemic uncertainty in available approaches for the effect of site conditions on ground motion hazards. At the I PRP meeting on July 11 , 2013, PG&E indicated it would study site amp I ification analytically and make use of its detailed 3D velocity data for the DCPP site. We conclude that PG&E's state-of-the-art approach to site amplification (based on recorded ground motions) and ground motion variability (single station sigma) is reasonable and makes intuitive sense. However, we conclude that further justifications/clarifications to the PG&E approach are necessary, particularly because the PG&E approach gives lower ground motion hazard estimates in the period range important to DCPP compared to other state-of-the-practice approaches used currently in the U.S. National Seismic Hazard Maps and in International and California building codes. PG&E should demonstrate that the low site amplification seen at the DCPP site is due to site effects. not specific to the azimuths and distances traveled by the recorded ground motions at the site from the two earthquakes used. PG&E should also justify the adequacy of using only two earthquakes to characterize site amplification, particularly because these two earthquakes cover only a small range of the azimuths that seismic waves can travel toward the DCPP site. Near surface Vs data at the DCPP site indicate significant variability/uncertainty (Vs30 ranging from 696 mis to 1 ,646 mis). PG&E should evaluate whether and how this specific variability/uncertainty is captured adequately by its approach that quantifies uncertainty in site amplification based on site-to-site uncertainty (not a site specific parameter) in the single station sigma method. IPRP Report 6, Page 20 PG&E's approach in K estimation is different from approaches that are commonly applied. Usually, K is estimated from the Fourier spectra of recorded ground motions or from subsurface material properties. We would appreciate justifications/explanations to the PG&E's approach. In a public meeting held on July 11, 2013, PG&E indicated that they plan to conduct further studies to improve the quantification of site amplification: 1. PG&E will use new data from recently completed on-land exploration geophysics surveys to develop a new model of Vs beneath the plant site. Initial results of surveys presented by PG&E from one profile suggest that this analysis will result in a well-constrained 3-D model of shear-wave velocity beneath the plant. 2. PG&E will analyze broad band ground motion data to rule out path effects in the current site-specific amplification terms. Since data from two earthquakes are not sufficient to demonstrate that the amplification factors include only modifications of the shaking due to site effects, recorded motion from other earthquakes, particularly earthquakes from the south and west, may help rule out path effects in the amplification terms. 3. PG&E will evaluate site amplification using analytical approaches in which seismic waves are propagated through a velocity model. This approach is more typical of state-of-the-practice for critical facilities and will provide a comparison to the ground shaking evaluation using the site-specific amplification factors. The additional studies by PG&E appear to be well conceived to address the uncertainty in site conditions at DCPP. Considering the large effects on seismic hazard results from different estimates of site conditions and different methods in considering site conditions in seismic hazard analysis, the IPRP will be interested in additional briefings by PG&E on the results of their surveys and analyses. REFERENCES Abrahamson, N.A.. and W. Silva, 2008. Summary of the Abrahamson and Silva NGA ground-motion relations, Earlhquake Spectra, v 24, n 1, p 67 -98. Anderson, J. G., and S. E. Hough. 1984, A model for the shape of the Fourier amplitude spectrum of acceleration at high frequencies, Bulletin of Seismological Society of America, v 74, p 1969-1993. BCHydro (2010). Probabilistic Seismic Hazard Analysis, Volume 3: Ground Motion Report, Draft Nov 3, 2010. Boore, D. M., 2000, SMSIM -Fortran programs for simulating ground motions from earthquakes: version 2.0 -a revision of OFR 96-80-A, U.S. Geological Survey OFR 00-509. IPRP Report 6, Page 21 Boore, D.M., and G.M. Atkinson, 2008, Ground-motion predication equations for the average horizontal component of PGA, PGV, and 5%-damped PSA at spectral periods between 0.01 s and 10.0 s, Earthquake Spectra, v 24, n 1, p 99 -138. Campbell, K.W., and Y. Bozorgnia, 2008, NGA ground motion model for the geometric mean horizontal component of PGA, PGV, PGD and 5% damped linear elastic response spectra for periods ranging from 0.01 s to 10.0 s, Earthquake Spectra, v 24. n 1, p 139-172. Chiou. B.S-J .. and R.R. Youngs, 2008. An NGA model for the average horizontal component of peak ground motion and response spectra, Earthquake Spectra, v 24, n 1, p 173-216. Brune, J. N., 1970, Tectonic stress and the spectra of seismic shear waves from earthquakes, Journal of Geophysical Research, v 75, p 4997 -5009. Hanks, T. C., 1982, fmax. Bulletin of the Seismological Society of America, v 72, p 1867 -1879. Hough, S. E., J. G. Anderson, J. Brune, F. Vernon, J. Berger, and J. Fletcher, 1988, Attenuation near Anza, California, Bulletin of the Seismological Society of America, v 78, p 672 -691. Houtte, C.V., S. Drouet, and F. Cotton, 2011, Analysis of the original of K (Kappa) to compute hazard rock to rock adjustment factors for GMPEs, Bulletin of the Seismological Society of America, v 101, n 6, p 2926 -2941. Nuclear Regulatory Commission, 2012, Confirmatory Analysis of Seismic Hazard at the Diablo Canyon Power Plant from the Shoreline Fault Zone, Research Information Letter 12-01. Pacific Gas and Electric Company (PG&E), 2011a. Report on the Analysis of the Shoreline Fault Zone, Central Coastal California, Report to the U.S. Nuclear Regulatory Commission, January. Pacific Gas and Electric Company (PG&E), 2011 b, Response to IPRP Request for Hazard Sensitivity for Targets for the DCPP Geophysical Surveys, August 8. Pacific Gas and Electric Company (PG&E), 1988, Final report of the Diablo Canyon long-term seismic program, U.S. Nuclear Regulatory Commission Docket No. 50-275 and No. 50-323. Pacific Gas and Electric Company (PG&E), 1991 , Addendum to the 1988 Final Report of the Diablo Canyon Long Term Seismic Program, U.S. Nuclear Regulatory Commission Docket No. 50-275 and No. 50-323. February 1991. Papageorgiou, A. S., and K. Aki, 1983, A specific barrier model for the quantitative description of inhomogeneous faulting and the prediction of strong ground motion, Bulletin of the Seismological Society of America, v 73, p 693 -722. Silva. W., 2008. Site Response Simulations for the NGA Project, Pacific Engineering and Analysis, El Cerrito, CA IPRP Report 6, Page 22 Silva, W., and R. B. Darragh, 1995, Engineering characterization of strong ground motion recorded at rock sites, Technical report, Electric Power Research Institute, El Cerrito, California. EPRI Report TR-102262. Tsai, C.-C. P., and K.-C. Chen, 2000, A model for the high-cut process of strong-motion accelerations in terms of distance, magnitude, and site condition: An example from the SMART 1 Array. Lotung, Taiwan, Bulletin of the Seismological Society of America, v 90, p 1535-1542. Wills, C.J .. and K.B. Clahan. 2006, Developing a map of geologically defined condition categories for California, Bulletin of the Seismological Society of America, v 96, n 4A, p 1483 -1501. IPRP Report 6, Page 23 STATE OF CALIFORNIA EDMUND G. BROWN JR., GOVERNOR Independent Peer Review Panel A m/lvU-v-ag-e,,woy pcvfl/e'b of J*e,,t/;*mio Ju;v;'(;l,/yd-¥peoU:vbt/JCJ* try rluY Ccvb£k,,-nva,,, Pu!J-Uo lirvb1:.TV&J* Co-mmt/Jri&w CALIFORNIA GEOLOGICAL SURVEY, CALIFORNIA COASTAL COMMISSION, CALIFORNIA PUBLIC UTILITIES COMMISSION, CALIFORNIA ENERGY COMMISSION, CALIFORNIA SEISMIC SAFETY COMMISSION, COUNTY OF SAN LUIS OBISPO IPRP Report No. 9, March 6, 2015 Comments on PG&E's Central Coastal California Seismic Imaging Project Report part 3: onshore seismic studies intended to reduce the uncertainty in seismic hazard at Diablo Canyon Power Plant BACKGROUND In 2006, the California Legislature enacted Assembly Bill (AB) 1632, which was codified as Public Resources Code Section 25303. AB 1632 directed the California Energy Commission (CEC) to assess the potential vulnerability of California's largest baseload power plants, which includes Diablo Canyon Power Plant (DCPP), to a major disruption due to a major seismic event and other issues. In response to AB 1632, in November 2008 the CEC issued its findings and recommendations in its AB 1632 Report, which was part of its 2008 Integrated Energy Policy Report Update. As noted in the CEC's AB 1632 Report, a major disruption because of an earthquake or plant aging could result in a shutdown of several months or even cause the retirement of one or more of the plants' reactors. A long-term plant shutdown would have economic, environmental and reliability implications for California ratepayers. In Pacific Gas and Electric Company's (PG&E) 2007 General Rate Case decision D.07-03-044, the California Public Utilities Commission (CPUC) directed PG&E to address and incorporate the recommendations from the AB 1632 Report into its feasibility study to extend the operating licenses of its Diablo Canyon Units 1 and 2 for an additional 20 years. In November 2009, PG&E submitted its formal application with the Nuclear Regulatory Commission (NRC) to extend the licenses of DCPP Units 1 and 2. In 2010 PG&E filed for cost recovery with the CPUC for expenditures associated with the enhanced seismic studies recommended by the CEC's AB 1632 Report. The motions for cost recovery were subsequently approved in 2010 and 2011. CPUC Decision D.10-08-003, issued on August 16, 2010, established that the CPUC would convene its own Independent Peer Review Panel (IPRP) and invite the CEC, the California Geological Survey, the California Coastal Commission, and the California Seismic Safety Commission to participate on the panel. Under the auspices of the CPUC, the IPRP is conducting an independent review of PG&E's seismic studies including independently reviewing and commenting on PG&E's study plans and the findings of the studies. The comprehensiveness. completeness. and timeliness of these studies will be critical to the CPUC's ability to assess the cost-effectiveness of Diablo Canyon's proposed license renewal. IPRP reports 7, 8 and this report respond to studies released by PG&E on September 10, 2014. Those studies are referred to collectively as the Central Coastal California Seismic Imaging Project (CCCSIP) report. The CCCSIP report is divided into 14 chapters focused on individual studies intended to help constrain factors that are important to seismic hazard analysis. Due to the large volume of information presented in the CCCSIP report, IPRP's review of the document was divided into three sections. IPRP Report No. 7, issued November 21, 2014, reviewed offshore seismic surveys as presented in chapters 2 and 3 of the CCCSIP report. IPRP Report No. 8, issued December 17, 2014, reviewed onshore seismic surveys and analysis as presented in chapters 7,8,9 and 12 of the CCCSIP report. This IPRP report is the third part of IPRP's review of the CCCSIP report. It includes onshore seismic studies in the immediate area of the DCPP and the hazard parameters that they are designed to study. These studies. Chapters 10, 11. and 13 of the CCCSIP report, were the subject of a public meeting on January 8, 2015. The focus of chapter 10 is on the shear-wave velocity (Vs) of the geologic material beneath DCPP. Following the public meeting on January 8, 2015, the IPRP had a number of additional questions regarding the velocity model described in Chapter 1 O and requested an additional meeting with PG&E. PG&E declined to meet again with IPRP. As a result, this report only covers aspects of those models described in the CCCSIP report and the public meeting. Chapter 11 describes PG&E's evaluation of such "site conditions" and methods to consider "site response amplification" in seismic hazard calculations. Chapter 13 describes hazard sensitivity by comparing response spectra for selected scenario earthquakes with response spectra previously used for DCPP. SUMMARY OF PREVIOUS RECOMMENDATIONS The IPRP previously reviewed DCPP site conditions and PG&E site amplification approaches documented in the Shoreline Fault Report (PG&E, 2011) and documented its findings and recommendations in IPRP Report No. 6. Important findings and recommendations from that report and PG&E responses are summarized briefly in this section to facilitate discussion. In the 2011 Shoreline Fault Report. PG&E estimated the average shear-wave velocity in the upper 30 m (Vs30), commonly used to represent "site conditions", to be 1200 m/s. IPRP Report No. 6 noted that "Vs data at the DCPP site indicate significant variability /uncertainty" and that PG&E's estimates "appear to include unconservative assumptions IPRP Report No. 9, Page 2 of velocity in boreholes". IPRP recommended additional studies to determine the Vs beneath DCPP and the variability of Vs. While the IPRP found the empirical approach used by PG&E to incorporate site-specific amplification reasonable and intuitive, the panel concluded that further justifications/clarifications are necessary. Specifically, IPRP Report No. 6 recommended that PG&E "demonstrate that the low site amplification seen at the DCPP site is due to site effects, not specific to the azimuths and distances traveled by the recorded ground motions at the site from the two earthquakes used" and "justify the adequacy of using only two earthquakes to characterize site amplification". In response, PG&E confirmed in a letter to CPUC (PG&E, 2013) that it would conduct further studies to improve the quantification of site conditions and amplification. These studies would: (1) use new data from on-land exploration geophysics surveys to develop a 30 model of shear wave velocity beneath the plant site; (2) analyze broad band ground motion data and ground motions from small earthquakes to better quantify site-specific amplification terms; and (3) evaluate site amplification using analytical approaches in which seismic waves are propagated through a velocity model. The CCCSIP report addressed the first study as discussed in detail in the remainder of this IPRP report, but not the second and third studies. DCPP SITE SHEAR WAVE VELOCITY AND SITE CONDITIONS Chapter 1 O of the CCCSIP report presents the "CCCSIP DCPP P-and S-Wave Foundation Velocity Report". Background, methods and conclusions of this study were presented at the IPRP meeting on January 8, 2015 by Dr. Daniel O'Connell of Fugro Consultants. The CCCSIP study consisted of new 3D tomographic imaging of the geologic material beneath DCPP to a depth of about 3000 ft. The tomographic imaging used the same seismic survey sources and receivers as the reflection seismic surveys discussed in IPRP Report No. 8 and used the resulting data, combined with gravity data, to estimate p-wave ands-wave velocities in 3-dimensional cells. Velocity estimates were made for 200x200x200 ft cells underneath the Irish Hills and higher resolution 50x50x10 ft cells in the area around DCPP. The presentation by Dr. O'Connell showed some images of the tomographic model of the Irish Hills. These images show some of the same large-scale features of the geology of the Irish Hills as the seismic reflection studies and geologic mapping described in other chapters of the CCCSIP report, including higher-velocity material consistent with uplifted Franciscan Complex bedrock in the northern Irish Hills, velocity material in the central to southern Irish Hills consistent with the Pismo Syncline, and higher-velocity material along the south edge of the Irish Hills consistent with areas where diabase is mapped at the surface or projected into the subsurface. IPRP Report No. 9, Page 3 The high-resolution tomographic model of the area near DCPP presented in the CCCSIP report shows details of the variation in interpreted velocity. Important elements of this detailed model include: relatively low near-surface velocities in areas with remaining natural soil; relatively high near-surface velocities underlying much of the plant itself; highly variable estimates of Vs30; and irregularly shaped subsurface regions interpreted to have high velocity. While each of these features of the tomographic model may represent improved understanding of the "site conditions" at DCPP and may lead to decreased uncertainty in seismic hazard estimates, PG&E has not confirmed the uncertainties in these velocity estimates. Moreover, the CCCSIP report has an extensive discussion of the difficulty of gaining accurate tomographic results at shallow depths, given the constrained receiver locations. Estimates of seismic shaking are commonly calculated for a "firm rock" site condition with a Vs30 of 760 m/s, then adjusted for the Vs30 of the site. In previous evaluations, PG&E estimated a Vs30 of 1200 m/s for DCPP. IPRP Report No. 6 noted that this value did not reflect the values or variability of Vs measured in 1978. The CCCSIP report presents Vs profiles and estimates of Vs30 of 570 mis and 750 mis for two sites adjacent to DCPP. For additional context, the CCCSIP report provides Vs30 estimates ranging from 429 to 479 m/s for five sites in the DCPP area. The CCCSIP report estimates Vs30 of 980 m/s at the basement elevation of the turbine building and 1260 m/s at the basement elevation of the power block. The variation in Vs30 estimated from the tomographic model support the IPRP interpretation of "overall lower velocity of the rock underlying the plant and greater variability in velocity across the plant footprint" relative to PG&E's previous interpretation. Much of this variation in Vs is expected on a site that has been graded. Low velocities are modeled in soil and deeply-weathered rock. Removal of soil and weathered rock in preparing excavations for construction results in higher Vs3o. The tomographic model depicts the expected variability in shear wave velocity. Vs30 of 750 at seismic station ESTA 28 adjacent to the south side of the turbine building and 570 mis at seismic station ESTA 27 north of the turbine building are consistent with removal of soil and weathered rock from these sites. Simply considering the amount of grading, Vs30 values at DCPP can be expected to be lower than 760 mis at the ground surface around the south, west, and north sides of the turbine building and higher on the east and around the power block. Higher values would be expected at foundation levels, where more weathered rock has been removed and higher-velocity rock is at the surface. The IPRP understands that the purpose of the detailed 3-dimensional velocity model is to replace the simple Vs30 index with detailed amplification estimates that take into account of the velocity structure of the rock underlying the plant. For comparison of IPRP Report No. 9, Page 4 ground motion estimates below, the IPRP is using 760 m/s, the approximate value at the ground surface adjacent to the south side of DCPP, in estimating ground motion at DCPP. In addition to the variation in Vs at the surface due to grading, the CCCSIP report suggests that irregularly shaped diabase bodies in the subsurface lead to large variations in seismic velocity. The centers of some regions interpreted to be diabase bodies are estimated to have p-wave velocities of over 5000 mis, nearly double the velocity of the surrounding sedimentary rock. The presentation by Dr. O'Connell showed that the detailed tomographic model includes modeled diabase bodies to a depth of about 1000 feet below DCPP. The high-resolution tomographic model of the DCPP region is dependent on details of seismic data acquisition and processing. Also, as noted above, PG&E has not provided estimates of the uncertainty in velocity estimates included in the model. One way to check the accuracy of the model is to compare it with other measurements of p-and wave velocity in the same area and with expected velocities in similar materials statewide. Chapter 10 of the CCCSIP report provides profiles of modeled Vs with depth at numerous locations. These can be compared with profiles measured at the DCPP in 1978. Previous Vs measurements were provided to the IPRP as described in IPRP Report No. 6. Comparison of Vs profiles from the tomographic model with profiles measured in 1978 shows broadly similar ranges of Vs and variation of Vs with depth. In detail, however, Vs profiles from the tomographic model do not appear to reproduce the variation in Vs with depth in nearby measured profiles. The most prominent feature in previous profiles is the high-velocity zone centered at approximately 50' elevation in profile DDH-C (Figure 1 ). The tomographic model includes a high-velocity zone near this elevation. but not in any of the profiles near the site of profile DDH-C presented on transects B-B' or D-D'. Below the high-velocity zone, profile DDH-C shows lower velocity (731 m/s) but all nearby profiles from the tomographic model show increasing velocity through this zone, reaching velocities of over 1600 m/s in the profile at 1000 ft on transect B-B' (the closest profile to DDH-C presented in the CCCSIP report). Downhole profile DDH-D shows much less variation of Vs with depth than the nearest profile shown in the CCCSIP report. Differences between Vs profiles measured in 1978 and profiles derived from the tomographic model may reflect poor data or poor resolution in the 1978 profiles. If the 1978 downhole velocity surveys represent "ground truth", however, it appears that the tomographic model does not show some shallow high velocity layers up to 50' thick or low velocity layers up to 100' thick. The lack of correspondence between measured Vs profiles and Vs profiles estimated from the tomographic model suggests significant uncertainty remains in estimates of "site conditions" at DCPP. The IPRP cannot IPRP Report No. 9, Page 5 determine if these differences reflect poor data or analysis in one or both measurements of Vs or if both surveys are essentially correct, but have differing levels of spatial resolution. Certainly, the differences between Vs profiles from the tomographic model and previously measured Vs profiles should have been addressed in the CCCSIP report. Vs (m/sec) 500 1000 1500 2000 200 60 GeoTomo Vs model profiles Site East (ft.) North (ft. I Elev. (ft. I B-1000 5709014.5 2275061.3 87.0 40 0 0 <> D* 700 5709256. 7 2275418 7 1170 100 <> <> 1978 Oownhole Vs profiles <> <> I "ol I DOH*C 20 I DDH-D { 0 0 !, 00 -'E <> < c: <> 0 c: 0 <>o 0 B *20 > /'. o0 Cl) .92 w 0 <> . UJ -100 -40 *200 80 2000 4000 6000 8000 Vs (ft/sec) Figure 1. Comparison of measured Vs profiles from 1978 with the nearest profile from the 30 tomographic survey presented in the CCCSIP report. Site B-1000 is closest to downhole profile DDH-C. Site D-700 is closest to profile DDH-D. Profiles from 30 model from CCCSIP report, Chapter 11, Figures B-2 and B-4. IPRP Report No. 9, Page 6 PG&E SITE RESPONSE METHODOLOGY AND SITE AMPLIFICATION CALCULATION The PG&E methodology to account for site response in its CCCSIP report is essentially the same as the methodology documented in the Shoreline Fault Report. However. the CCCSIP methodology incorporated two new developments: (1) the new Vs30 values at the two free field ground motion recording stations and at the foundation levels of the power block and the turbine building, and (2) four new ground motion prediction equations (GMPEs) developed as part of the 2014 updates of the Next Generation Attenuations for Western United States (NGA West2). The new Vs30 values were developed based on the new shear wave velocity data interpreted from the resolution tomographic model. IPRP review of the new Vs30 values is documented in the previous section of this report. Evaluation of NGA West2 GMPEs is beyond the scope of this review. However, we note PG&E indicated in its CCCSIP report that it would conduct a complete evaluation of the NGA West2 GMPEs as part of the Southwestern United States (SWUS) Senior Seismic Hazard Analysis Committee (SSHAC) ground motion studies required by the NRC. We also note the NGA West2 GMPEs were developed via a multidisciplinary, multi-year research program coordinated by the Pacific Earthquake Engineering Research Center (PEER) (Bozorgnia et al., 2014) and have been adopted in the 2014 updates of the National Seismic Hazard Maps (Petersen et al., 2014). The incorporation of these new developments necessitated recalculation of site amplification parameters. The PG&E methodology consists of two components: (1) an empirical site-specific site term that accounts for differences in observed ground motions at the DCPP site and an average site depicted by the GMPEs for a reference site condition. and (2) a site amplification term that accounts for differences between sites with different Vs30 values reflecting differences in shallow Vs profiles. We refer to these two terms as site-specific term and Vs30 scaling term. respectively. In the CCCSIP report, recording station ESTA28 (Vs30 = 753 mis, approximated as 750 m/s) was selected to be the reference free field site. Ground motions recorded at station ESTA27 (Vs30 = 570 m/s) were adjusted to the reference site condition. Following the procedure described in the Shoreline Fault Report, a site-specific term at each frequency is determined as the mean residuals from the two available earthquakes (averaged period by period and smoothed over a period range) and uncertainty is estimated based on station-to-station variability from a worldwide dataset and number of available earthquakes recorded at the DCPP (2 earthquakes). The values of the smoothed mean residuals (i.e., site specific term for reference Vs30 of 760 m/s) and uncertainty range are listed in Table 3-1 and illustrated in Figure 3-4, Chapter 11 of the CCCSIP report. IPRP Report No. 9, Page 7 In the Shoreline Fault Report, scaling of ground motions for sites with different Vs 30 values was based on the site response analysis results of Silva (2008). In the CCCSIP report, PG&E scaled ground motions at the reference site ( Vs30 = 760 mis) to the power block foundation (Vs30 = 1260 mis, approximated as 1200 mis) using scaling factors derived from site response analysis carried out by the NRC (2012) using a DCPP shear wave velocity profile with Vs30 of 1200 mis. In applying the NRC scaling factors, PG&E made additional corrections to account for difference in basin depth according to the studies of Kamai et al. (2013). Scaling factors from the reference site to the turbine building were interpolated from scaling factors from the reference site to the power block. Amplification factors for Vs30 scaling (i.e., Vs30 scaling term) are listed in Table 3-2 for the foundations at the power block and turbine building and are illustrated in Figure 3-5 (for power block foundation) in Chapter 11 of the CCCSIP report. The total site-specific amplification factor (in natural log scale) for each site with respect to the NGA West2 predictions for a reference rock site of Vs30 = 760 mis is the sum of the site specific term (Table 3-1 in Chapter 11 of the CCCSIP report) and the Vs30 scaling term for that site (Table 3-2 in Chapter 11 of the CCCSIP report). The total 2 1.8 -1.6 Ill -E 1.4 " 0 .. Cll 1.2 .i? 1;j a; 1 ... -... 0 ti ::!. 0.8 c .2 t: 0.6 Cll ... ... 0 v 0.4 0.2 0 0.1 \ \ ' 1, I \ -SiteAmp-CCCSIP * * * *

• Upper Range -CCCSIP * * * *
• Lower Range
• CCCS IP --exp(site_amp)-SFR ---SFR +lo ---SFR -lo ', :** .. ' ' : A **.,\ .. **' .. , ' ., . .._.,, ' :, ' . ' :, \: \: \ \: -SFR +20 --SFR -2o '* --... __ ,, ' ... " ., ..... ----........ \ ' '"" ... , ...... ,,,,.,. ' . \ .. . _..,. _______ _,-:.* . . ** ............. \ '1 ---.-;. ** ** ... **************** 1 10 100 Frequency (Hz) Figure 2. Comparison of site-specific amplification factors (in linear units) and associated uncertainty in the CCCSIP report and the Shoreline Fault Report (SFR) (plotted according data presented in the CCCSIP report, SFR, and presentation by Norm Abrahamson on June 6, 2013, a is standard deviation). IPRP Report No. 9, Page 8 amplification factors for the foundation levels at the power block and the turbine building are listed in Table 3-3, Chapter 11 of the CCCSIP report. Figure 2 compares updated site amplification factors and associated uncertainties in the CCCSIP report with those used in the Shoreline Fault Report. In general, the new factors are slightly lower. However, given large uncertainty in site amplification, the difference should be considered insignificant. HAZARD SENSITIVITY AND IMPACT Impact of the updated fault source and site amplification parameters on ground motion hazards at the DCPP site was evaluated using a simple, deterministic approach in Chapter 13 of the CCCSIP report. Changes in source parameters that have potential impact in estimated ground motion hazards include: increase in Shoreline Fault length (from 23 km to 45 km); coseismic rupture of the Shoreline, Hosgri, and San Simeon Faults with a potential magnitude of 7.3; the longer trace, shallower dip for the Hosgri Fault; coseismic rupture of the Hosgri and San Simeon Faults with a potential magnitude of 7. 3; and increase in the minim um dip angle for the Los Osos Fa ult (by 10 degrees). There is no change to the San Luis Bay Fault. Figure 3 compares deterministic ground motion spectra presented in the CCCSIP report (for the turbine building foundation level, Vs30 = 980 m/s, solid curves) and the Shoreline Fault Report (for the DCPP site with Vs30 = 1200 mis, dashed curves) for the four most important fault sources affecting the DCPP site. The PG&E 1991 L TSP/SSER 34, the 1977 HE (Hosgri Earthquake) design spectrum, and the frequency range important to DCPP structures (marked by vertical dark grey lines) are plotted for reference. Although the CCCSIP updates resulted in different ground motions for individual scenarios, there is little difference in estimated ground motion portrayed by the four scenarios as a group. Ground motion is higher for the linked Hosgri and San Simeon M7.3 scenario compared to the SFR Hosgri M7.1 scenario, except at frequency lower than 1 Hz. The updated Los Osos MS.7 scenario resulted in lower ground motions across the spectrum due to combined effects of the new GMPEs, slightly lower site amplification factors, and steeper minimum dip angle. For the Shoreline and San Luis Bay Fault scenarios, slightly lower ground motions were predicted by the CCCSIP updates for frequency range of 3 to 1 O Hz. All scenario spectra fall below the 1991 L TSP and the 1977 HE design spectra. For each earthquake scenario, the CCCSIP deterministic spectrum for the power block foundation level (Vs30 = 1200 m/s) is slightly lower than the CCCSIP spectra for the turbine building foundation level shown in Figure 3 due to higher Vs30 value at the power block foundation level. To illustrate important aspects of seismic hazard evaluation at the DCPP site, Norm Abrahamson presented an updated "tornado plot" at the January 8, 2015 IPRP meeting. The updated tornado plot is re-produced as Figure 4 in this report to facilitate IPRP Report No. 9, Page 9 2.5 2.0 0.5 0.0 0.1 Comparison of CCCSIP and SFR Spectra --Linked Hosgri7.3_ TB_CCCSIP --Los Osos6. 7 _TB_ CCCSIP Shoreline6.7 _ TB_CCCSIP --San Luis Bay6.4_TB_CCCSIP ---Hosgri7 .l_SFR ---Los Osos6.8_SFR Shoreline6.S_SFR ---San Luis Bay6.3_SFR ---1977 Spectrum --1991 LTSP Spectrum 1.0 10.0 Frequency (Hz) 100.0 Figure 3. Comparison of deterministic ground motion spectra from the CCCSIP update for the turbine building foundation level (Vs30 = 980 m/s, solid curves) and from the Shoreline Fault Report for the DCPP site (Vs30 = 1,200 m/s, dashed curves). The PG&E 1991LTSP/SSER34, the 1977 HE (Hosgri Earthquake) design spectrum, and the frequency range important to DCPP (bracketed by vertical dark grey lines) are also plotted for reference. discussion. The horizontal axis is the ratio of 5 Hz hazard at 2 g spectral acceleration to the reference hazard of 10-4 annual rate of exceedance (i.e., the approximate base case hazard for 5 Hz at 2 g spectral acceleration at the DCPP site). The vertical axis ranks sensitivity of ground motion hazard to various input parameters. The updated tornado plot illustrates the reduction of uncertainties in some source parameters based on information developed by the AB1632 studies as reported in the CCCSIP. We note that uncertainty reductions shown in the updated tornado plot is based on PG&E's updated PSHA analyses as part of the SSHAC process. IPRP has not reviewed these new calculations and cannot comment on whether the reductions seen on the updated tornado plot are reasonable. The most striking feature of this updated tornado plot is the 6 items related to ground motion calculation on the top of the tornado that have considerably greater uncertainty and hazard sensitivity compared to the source parameters (lower part of the tornado starting from Hosgri slip rate). The IPRP previously recognized the importance of ground motion calculation parameters (including site specific amplification and ground IPRP Report No. 9, Page 10 Hazard Sensitivity 5 Hz, PSA::: 2g Nor--Frgod1c Pa:h . ** . . . ******* Non-Eri;od1c Source . . ... . . *** Mec1an from GMPf: Si1e Amplification 1-------* *---***---.. Sigm;iSS Model Time Deper.dent haza-d Hosgri Slip Rate Hosgri Dip S1ore11ne Shp Rate . :"*. Los Osos Dip . L:.is Ow:. Slip Rate Shoreline and Hos!;ri L*nking . ,. ! 1 0.01 0, , 1(1 ti<i..:arrJ Ralio (not GM rcrtioi SS'-?011 SSC 2014
• GMC ?014
• Non-E*goc1c G\llC Figure 4. "Tornado Plot" ranking sensitivity of ground motion hazards to uncertainty in input parameters (presented by Norm Abrahamson at the January 8, 2015 IPRP public meeting). motion uncertainty or sigma model) and illustrated their importance in ground motion estimation using a "half tornado plot" in IPRP Report No. 6 (Figure 10). Figure 5 further illustrates the significant impact of ground motion sigma model and site amplification on estimated ground motions. The sensitivity cases illustrated in Figure 5 are based on earthquake scenarios and site amplification parameters developed in the CCCSIP report and the NGA West2 GMPEs. The two components of the overall site amplification (i.e., site-specific term and Vs30 scaling) are separated to illustrate their relative importance. Figure 5 compares the CCCSIP deterministic spectra for the turbine building foundation (calculated using the single station sigma assumption, site-specific term, its uncertainty, and scaling from Vs30 of 760 mis to 980 m/s) with two sensitivity cases: (a) an average site with Vs30 of 760 m/s using the ergodic assumption (i.e., a4th percentile ground motion calculated directly using GMPEs); and (b) a DCPP site with Vs30 of 760 mis using the single station sigma assumption, the site-specific term and its uncertainty (i.e., IPRP Report No. 9, Page 11 eliminating the scaling from Vs30 of 760 mis to 980 m/s compared to the CCCSIP spectra). Figure 5a shows that the deterministic spectra calculated based on the ergodic assumption exceed the 1977 HE and the 1991 L TSP spectra for all but one scenarios in the period range important to DCPP, which re-illustrates observations made in the IPRP Report No. 6 and depicted in Figure 7c of that report. Scaling of Vs30 from 760 m/s to 980 m/s decreases deterministic ground motion across the spectrum, except for frequencies less than 1 Hz (Figure 5b). Differences between the Vs30 of 760 m/s cases (solid curves) shown in Figures Sa and Sb reflect differences when ergodic assumption is used (Figure Sa) versus when single station sigma with site specific term is used (Figure Sb). For the OCPP site, the use of single station sigma with site-specific term appears to be the key factor that brings the deterministic spectra below the original design spectra. While the single station sigma assumption and especially the site term have a significant effect on hazard, the site term is based on the observations of only two earthquakes. As described in IPRP Report No. 6, the IPRP is not convinced that the "site term" reflects some property of the site that would affect all earthquakes recorded at OCPP. The alternative hypothesis that additional factors related to the particular source or paths of those two earthquakes remains at least as plausible. The CCCSIP report does not include any additional studies to address this issue. The 30 site response analyses proposed by PG&E will not address whether single station sigma model is more reasonable than the ergodic assumption, nor will it reduce uncertainty in the site specific term that is calculated based on two recorded earthquakes. The proposed 30 site response model will address Vs30 scaling and the effect of large variability in Vs30 values at the DCPP site. Figure 6 compares deterministic spectra for the CCCSIP sensitivity scenario assuming linked co-seismic rupture of the Shoreline, Hosgri, and San Simeon Faults (M7.3). It shows that deterministic ground motion increases across the spectrum as magnitude for the Shoreline Fault rupture increases from 6.7 to 7.3. This figure also shows increased ground motion as Vs30 decreases from 1200 mis [at the power block foundation level] to 760 m/s. More significantly, the figure shows, once again, that the most influential factor affecting deterministic ground motion estimates is the single station sigma assumption and the site term. IPRP Report No. 9, Page 12 Comparison of CCCSIP Spectra at Turbine Building with Ergodic Spectra 25 2.0 0.0 0.1 --Hosgri7.3_760_erg --Los Osos6.7_760_erg Shoreline6. 7 _ 760 _erg --San Luis Bay6.4_760_erg ---Linked Hosgri7.3_TB_CCCSIP ---Los Osos6.7_TB_CCCSIP Shoreline6.7 _ TB_CCCSIP ---San Luis Bay6.4_TB_CCCSIP ---1977 Spectrum --1991 l TSP Spect ru rn 1.0 10.0 100.0 Frequency (Hz) Comparison of CCCSIP Spectra at Turbine Building with Single Station a Spectra 2.5 --Hosgri7 .3_760_ss --Los Osos6.7 _760_ss Shoreline6.7 _760_ss --San Luis Bay6.4_760_ss 2.0 ---Linked Hosgri7.3_TB_CCCSIP ---Los0sos6.7_TB_CCCSIP Qj Qj ... 1il a. 11'1 0.5 0.0 0.1 Shoreline6.7 _TB_CCCSIP ---San Luis Bay6.4_TB_CCCSIP ---1977 Spectrum --1991 L TSP Spectrum 1.0 ------10.0 100.0 Frequency (Hz) Figure 5. Comparison of deterministic ground motion spectra from the CCCSIP update for the turbine building foundation level (dashed curves; using single station sigma, site term, site term uncertainty, and scaling from Vs30 of 760 mis to 980 mis) with deterministic spectra of two sensitivity cases: (a) an average site with Vs30 of 760 mis using the ergodic assumption (i.e., calculated from GMPEs directly); and (b) A DCPP site with Vs30 of 760 mis using single station sigma assumption, and site-specific term and its uncertainty. The PG&E 1991 LTSPISSER 34, the 1977 HE (Hosgri Earthquake) design spectrum, and the frequency range important to DCPP (bracketed by vertical dark grey lines) are also plotted for reference. IPRP Report No. 9, Page 13 2.5 2.0 0.5 o.o 0.1 Comparison of Shoreline Spectra --Shoreline7 .3_760_erg --Shoreline? .3_760_ss Shoreline? .3_PB_ss_CCCSIP Sh ore Ii ne6. 7 _ps _SS_ c CCSI p ---1977 Spectrum -1991 LTSPSpectrum 1.0 ,--, I I I , I I I " Frequency (Hz) 10.0 100.0 Figure 6. Comparison of deterministic ground motion spectra for the Shoreline Fault rupture linked with the Hosgri and San Simeon Faults. CONCLUSIONS The CCCSIP report, chapter 10, presents a new high-resolution tomographic model intended to be used to model how seismic waves are modified as they pass through the rocks immediately beneath DCPP. That model shows overall lower Vs and greater variability of Vs than used in the Shoreline Fault Report, as the IPRP anticipated in Report No. 6. Estimates of Vs near the surface approximately reflect the amount of soil and weathered rock removed from the site during grading, as expected. Estimates of Vs30 are 570 m/s and 750 mis at ground level on opposite ends of the turbine building, within the range expected for the type of rock at these locations. Estimates of Vs30 for foundation levels are higher, reflecting removal of more weathered rock. While the estimated Vs values in the tomographic model correspond to expected relationships of Vs with depth, with removal of low-Vs material by grading, and general range of Vs for different geologic units these values do not correspond well to values previously measured in boreholes. PG&E has not reconciled these differences, nor have they provided estimates of uncertainty in the velocity values in the tomographic model. IPRP Report No. 9, Page 14 The PG&E methodology to account for site amplification in the CCCSIP report is essentially the same as in the Shoreline Fault Report. Nevertheless, site amplification factors were updated to incorporate two new developments: the new NGA West2 GMPEs and the updated Vs30 values for the two free field recording stations. The updated site amplification factors are generally lower than those in the Shoreline Fault Report. However, the difference is insignificant given large uncertainty in site amplification. The CCCSIP report states that the new 30 velocity model is to be used in 30 response analysis as part of the SSHAC process. The 30 response analysis may improve the estimate of site amplification from the reference site with Vs30 of 760 mis to the foundation levels of the power block and the turbine building. It could also account for the effect of highly variable Vs30 values at the OCPP site on estimated ground motion. The 30 response analysis cannot, however, address issues associated with the specific term. IPRP previously expressed its concern regarding the adequacy of using only two earthquakes in estimating the site-specific term and made recommendations to gain confidence in the PG&E site-specific approach, including analyzing broad band ground motion data and ground motions from small earthquakes to better quantify the site-specific term. PG&E has not addressed these recommendations. SUMMARY
• The CCCSIP report presents a detailed 30 velocity model that reproduces several expected variations in shear-wave velocity in subsurface, however: o Uncertainties of velocities are not clearly described. o Correspondence with previously measured velocities is poor.
• The single-station sigma approach has significant effects on calculated earthquake shaking. o Calculated ground motions using the 30 tomographic model should reflect uncertainties in that model, which have not been described. o The "site term" based on two recorded earthquakes may represent other factors, rather than site conditions. IPRP is not convinced that this factor is adequately constrained for use in ground motion calculations. IPRP Report No. 9, Page 15 REFERENCES Bozorgnia, Y., Abrahamson, N.A., Al Atik, L., Ancheta, T.D., Atkinson, G.M., Baker, J.W., Baltay, A., Boore, D.M., Campbell, K.W., Chiou, B. S.-J., Darragh, R., Day, S., Donahue, J., Graves, R.W., Gregor, N., Hanks, T., Idriss, l.M., Kamai, R., Kishida. T.. Kottke, A., Mahin, S.A., Rezaeian. S., Rowshandel. B., Seyhan, E .. Shahi, S., Shantz, T., Silva, W., Spudich, P., Stewart, J.P., Watson-Lamprey, J., Wooddell, K., and Youngs, R., 2014, NGA-West2 research project: Earthquake Spectra. v 30, p 973-987. Kamai, R., Abrahamson, N.A., and Silva, W.J., 2013. Nonlinear Horizontal Site Response for the NGA-West2 Project, Pacific Earthquake Engineering Research Center Report PEER 2013/12, May. Nuclear Regulatory Commission, 2012, Confirmatory Analysis of Seismic Hazard at the Diablo Canyon Power Plant from the Shoreline Fault Zone, Research Information Letter 12-01. Pacific Gas and Electric Company (PG&E), 2011, Report on the Analysis of the Shoreline Fault Zone, Central Coastal California, Report to the U.S. Nuclear Regulatory Commission, January. Pacific Gas and Electric Company (PG&E), 2013, PG&E Response to IPRP Report No. 6 Site Shear Wave Velocity at Diablo Canyon: Summary of Available Data and Comments on Analysis by PG&E for Diablo Canyon Power Plant Seismic Hazard Studies, Letter to California Public Utilities Commission, October. Pacific Gas and Electric Company (PG&E), 2014, Central Coastal California Seismic Imaging Project, Report to the California Public Utilities Commission, 3 volumes. 13 chapters, September 2014. Petersen, M.D., Moschetti, M.P., Powers, P.M., Mueller, C.S., Haller, K.M., Frankel, A.O., Zeng, Y .. Rezaeian, S., Harmsen, S.C., Boyd, O.S., Field, N., Chen, R., Rukstales, K.S., Luco, N., Wheeler, R.L., Williams, R.A., and Olsen, A.H., 2014. Documentation for the 2014 Update of the United States National Seismic Hazard Maps, USGS Open-File Report 2014-1091, 243 pp. Silva, W., 2008, Site Response Simulations for the NGA Project, Pacific Engineering and Analysis, El Cerrito, CA. IPRP Report No. 9, Page 16 Rochelle Becker From:Rochelle Becker Sent:l2 May 2015 13:08:44-0700 To:DiFranccsco, Nicholas Cc:Markley, Michael;Plasse, Richard;Wentzel, Michael;Walker, Wayne;Alexander, Ryan;Hipschman, Thomas;Maier, Bill;Li, Yong;Chokshi, Nilesh;Xu, Jim;Manoly, Kamal;P. Y.Chen@nrc.gov;Burke, John;Munson, Clifford;Stirewalt, Gerry;Lupold, Timothy;jstamatakos@swri.org;Lingam, Siva;Millcr, Chris;Dcan, Bill;Holian, Brian;Dapas, Marc;Johnson, Michael;Ake, Jon

Subject:

Written concerns -April 28th, 2015 webcast meeting with PG&E Attachments:IPRP Report No 6-1.pdf, IPRP Report No 8.pdf, IPRP Report No 9-1.pdf, 040315 A4NR Protcst-023.pdf, 051215 Rochelle Beckcr-NRC staff.pdf

Dear Mr DiFrancesco,

Please see attached letter. There are four referenced attachments as pdf files as well. Thank you Rochelle Rochelle Becker, Executive Director Alliance for Nuclear Responsibility PO 1328 San Luis Obispo, CA 93406 WWW .a4nr .On! BEFORE THE PUBLIC UTILITIES COMMISSION OF THE STATE OF CALIFORNIA Application of Pacific Gas and Electric ) Company for Compliance Review of Utility ) Owned Generation Operations, Electric Energy ) Resource Recovery Account Entries, Contract ) Application 15-02-023 (Filed February 27, 2015) Administration, Economic Dispatch of Electric ) Resources, Utility Retained Generation Fuel ) Procurement, and Other Activities for the Period ) January 1 through December 31, 2013. ) (U 39 E) ) ALLIANCE FOR NUCLEAR RESPONSIBILITY'S PROTEST Date: April 3, 2015 JOHN L. GEESMAN DICKSON GEESMAN LLP 1999 Harrison Street, Suite 2000 Oakland, CA 94612 Telephone: (510) 899-4670 Facsimile: (510) 899-4671 E-M ai I: joh n@dicksongeesman.com Attorney for ALLIANCE FOR NUCLEAR RESPONSIBILITY TABLE OF CONTENTS I. INTRODUCTION. 1 II. CHERRY-PEEVEY EMAILS REVEAL POST-FUKUSHIMA PR PLOY. 2 Ill. AB 1632 PROGRAM'S REVIEW SAFEGUARDS WERE BREACHED. 4 IV. PG&E SENT 'FINAL' REPORT TO THE NRC WITH NO IRPR REVIEW. 5 V. PG&E's 2014 'FINAL' REPORT STONEWALLED IPRP 2013 CRITIQUE. 7 VI. DR. BLAKESLEE SPOTLIGHTS PG&E's DECEPTIVE PATTERN. 14 VII. PG&E's POST-CCCSIP CONTEMPTUOUS DISCLOSURE. 16 VIII. TO LIVE OUTSIDE THE LAW YOU MUST BE HONEST. 18 IX. WHY A4NR PROTESTS. 21 APPENDIX A: PG&E SPECTRA CHARTS FROM CCCSIP REPORT A-1 APPENDIX B: PG&E LATE-DISTRIBUTED HAZARD CHART B-1 TABLE OF AUTHORITIES CALIFORNIA STATUTES AB 1632 ...................................................................................................... i, 1, 2, 4, 5, 6, 7, 8, 10, 13, 14, 15, 16, 17, 20 CALIFORNIA PUBLIC UTILITIES COMMISSION RULES Rule 2.6 .......................................................................................................................................................................... 1 CALIFORNIA PUBLIC UTILITIES COMMISSION DECISIONS D.10-08-003 ......................................................................................................................................................... 1, 4, 12 D.12-09-008 ..................................................................................................................................................... 1, 4, 5, 12 D.14-08-032 ................................................................................................................................................................... 1 OTHER AUTHORITIES IPRP Report No. l ........................................................................................................................................................ 12 IPRP Report No. 2 .......................................................................................................................................................... 4 IPRP Report No. 3 ...................................................................................................................................................... 4, 5 IPRP Report No. 6 ........................................................................................................................................ 5, 6, 7, 9, 13 I PRP Report No. 8 ...................................................................................................................................... 10, 11, 12, 16 IPRP Report No. 9 ...................................................................................................................................... 7, 8, 9, 10, 13 ii I. INTRODUCTION. Pursuant to Rule 2.6 of the Rules of Practice and Procedure of the California Public Utilities Commission ("Commission" or "CPUC"), the Alliance for Nuclear Responsibility ("A4NR") files its Protest to a portion of the 2014 Energy Resource Recovery Account Compliance ("ERRA Compliance") application filed by the Pacific Gas and Electric Company ("PG&E"). A4NR objects to PG&E's recovery of certain balances recorded in the Diablo Canyon Seismic Studies Balancing Account ("DCSSBA") for 2014 costs which fail to comply with D.12-09-008 and D.10-08-003 and, consequently, were not reasonably incurred. Additionally, D.14-08-032 directed PG&E to transfer funding for its Long Term Seismic Program ("LTSP"), including the Senior Seismic Hazard Analysis Committee ("SSHAC") process, to the DCSSBA effective January l, 2014, subject to reasonableness review in the ERRA Compliance process.1 A4NR protests recovery of certain LTSP amounts as well. A4NR's Protest focuses on PG&E's continued evasion of the Independent Peer Review Panel ("IPRP") established by the Commission to assist in the oversight of the ratepayer-funded AB 1632 seismic studies. The legal and factual grounds for the 2014 Protest are similar to those cited in A4NR's protest of PG&E's still-pending 2013 ERRA Compliance application, A.14-02-008, broadened to include the LTSP to the extent that non-compliant avoidance of IPRP review has contaminated core assumptions used in PG&E's SSHAC reports. Sadly, the 2013 evidence cited in A4NR's opening and reply briefs in A.14-02-008 has been augmented by increasingly brazen defiance by PG&E of D.12-09-008 and D.10-08-003, as outlined herein. 1 D.14-08-032, OP 29 a. The Commission stated, "We find this disposition to be a reasonable approach to improving oversight of the LTSP costs," (Jd., p. 411) and, "We find this disposition to be a reasonable approach to assure the proper integration of Assembly Bill (AB) 1632 seismic studies with the L TSP and the SSHAC process." (Id., p. 412) 1 II. CHERRY-PEEVEY EMAILS REVEAL POST-FUKUSHIMA PR PLOY. A4NR's Protest coincidentally follows the recent revelation of unreported ex parte communications in 2011 between PG&E Vice President Brian Cherry and Commission President Michael Peevey concerning PG&E's A.10-01-022, which sought ratepayer funding for the relicensing of the Diablo Canyon Nuclear Power Plant ("DCNPP"}. Five days after the Fukushima accident, AU Robert Barnett had taken the A.10-01-022 evidentiary hearing scheduled for April 13, 2011 off calendar. On April 11, 2011-just one month after the Japanese meltdown --PG&E ceremoniously announced it would accelerate completion of the AB 1632 seismic studies and requested the U.S. Nuclear Regulatory Commission ("NRC") "to delay final action on the utility's on-going license renewal application until PG&E submits the findings. "2 That same day, Mr. Cherry and President Peevey had the following exchange:3 From: Cherry, Brian K [17] Sent: Mon 4/11/2011 2:49 PM To: Peevey, Michael R.

Subject:

FW: Diablo Canyon License Renewal Attached is the letter mentioned in the press release. From: Peevey, Michael R. [18] Sent: Monday, April 11, 2011 4:34 PM To: Cherry, Brian K

Subject:

RE: Diablo Canyon License Renewal Very good. Prudent thing to do and should reduce some fears, concerns. 2 "PG&E Commits to Finishing 3-D Seismic Studies Related to Diablo Canyon Before Seeking Final Issuance of Renewed Licenses," news release from PG&E External Communications, April 11, 2011. The release quoted John Conway, Senior Vice President of Energy Supply and Chief Nuclear Officer: "We recognize that many in the public have called for this research to be completed before the NRC renews the plant's licenses," said Conway. "We are being responsive to this concern by seeking to expeditiously complete the 3-D seismic studies and provide those findings to the commission and other interested parties so that they may have added assurance of the plant's seismic integrity. " 3 Accessible at ftp://ftp2.cpuc.ca.gov/PG&E20150130ResponseToA1312012Ruling/2011/04/SB GT&S 0001262.pdf 2 From: Cherry, Brian K [19] Sent: Mon 4/11/2011 4:47 PM To: Peevey, Michael R.

Subject:

RE: Diablo Canyon License Renewal ... and resurrect our application and get it back on track? From: Peevey, Michael R. [mailto:michael.peevey@cpuc.ca.gov) Sent: Monday, April 11, 2011 5:04 PM To: Cherry, Brian K

Subject:

RE: Diablo Canyon License Renewal Yep. I will have Carol talk to Barnett. From: Cherry, Brian K [20] Sent: Mon 4/11/2011 5:05 PM To: Peevey, Michael R.

Subject:

RE: Diablo Canyon License Renewal Thanks. The sooner the better. From: Peevey, Michael R. [21] Sent: Monday, April 11, 2011 5:08 PM To: Cherry, Brian K

Subject:

RE: Diablo Canyon License Renewal May. From: Cherry, Brian K Sent: 4/11/2011 5:09:40 PM To: 'Peevey, Michael R.'(michacl.pccvcy@cpuc.ca.gov) Cc: Bee: Subject RE: Diablo Canyon License Renewal Great. And thanks again. 3 Ill. AB 1632 PROGRAM'S REVIEW SAFEGUARDS WERE BREACHED. A4NR relied upon the establishment of the IPRP by the Commission in D.10-08-003 to ensure that the AB 1632 studies were conducted as robust scientific inquiry and not as a public relations exercise. As AU Barnett made clear in that proceeding: And I say this, and I'll say it on the record, that part of this is because I don't want the Commission to be in a position of just accepting what the utilities tell us without looking at it. We've gotten in that position too many times, and I feel that the way to avoid that problem that we are just taking the utility at its word without the expertise to determine the reasonableness of that. That is why I think the IPRP is valuable, and why they should have an expert witness to review this stuff 4 The protocols for IPRP-PG&E interactions articulated in IPRP Report No. 2, 5 repeated verbatim in IPRP Report No. 3, 6 and reinforced by the admonition in D.12-09-008 ("We expect PG&E to 4 A.10-11-015 Transcript, p. 263. 5 IPRP Report No. 2, September 7, 2011, pp. 8 -9: "The JPRP expects that: *PG&E will provide its study plans and draft completed study findings to the I PRP for review. These include studies summarized in CPUC Decision 10-08-003 including off-shore, on-shore, and ocean bottom studies, and seismic studies recommended in the AB 1632 Report.

• The JPRP, coordinated by the California Geological Survey (CGS}, will review and provide comments on PG&E's study plans. The goal wilf be, if possible, to provide comments within 30 days of receipt.
• The JPRP, coordinated by the CGS, will review and provide comments on PG&E's draft completed study findings to the CPUC. The goal will be to provide comments as promptly as possible.
• PG&E will review and, if possible, within 30 days incorporate the I PR P's recommendations and comments in PG&E's revised study plans and revised completed study findings and prepare for the I PRP a 'Response to Comments' for the IPRP to document scientifically why PG&E accepted or rejected the IPRP's comments.
• PG&E and the JPRP will participate in quarterly meetings/briefings to review the status of PG&E's seismic studies, any changes in the study plans, and any preliminary study findings.
• PG&E and the JPRP will prepare a master schedule incorporating the major milestones for the IPR P's review process and will include these milestones in PG&E's monthly progress reports and schedule to the NRC and the Atomic Safety and Licensing Board.
• The CPUC and CEC will address any major scientific or technical issues that have not been resolved informally between the IPRP and PG&E. CPUC Decision 10-08-003 states that, 'Should a dispute arise it should be resolved informally but if that is not attainable the Commission has authority to halt the associated rate recovery.' In addition, the CEC may report on any seismic issues and updates through its JEPR process. However, we anticipate that any major scientific or technical issue that may arise can be addressed and resolved informally. The quarterly briefings/meetings mentioned above will allow PG&E to report on its progress and help facilitate a productive informal exchange of scientific viewpoints." 4 continue to meet with the IPRP to present and review changes to the seismic study plans, to provide process updates to the IPRP regarding implementation of the studies, and to receive /PRP comments."\ offered at least theoretical protection from the PG&E misconduct which surfaced in 2013 and worsened in 2014. IV. PG&E SENT 'FINAL' REPORT TO THE NRC WITH NO IRPR REVIEW. PG&E submitted what it labeled the "final" AB 1632 report to the NRC on September 10, 2014, six days after the evidentiary hearing in A.14-02-008, and without providing even a draft of the submittal to the IPRP. As the Director of PG&E's Geosciences Department explained at the A.14-02-008 hearing, PG&E had decided that the IPRP was only entitled to receive '1inalized"8 results of the studies after PG&E had issued a '1ina/"9 report to the U.S. Nuclear Regulatory Commission.10 As described in the evidentiary record of A.14-02-008, the extensive criticism of PG&E's ground motion assumptions at the July 11, 2013 IPRP meeting, followed by the eviscerating IPRP Report No. 6, appears to have significantly chilled relations between PG&E and the IPRP. One month after publication of IPRP Report No. 6, PG&E regulatory affairs personnel were complaining to CPUC staff about self-initiated reports by the IPRP and questioning whether the IPRP could be "decommissioned" after submittal of the 'Jina/" report.11 6 IPRP Report No. 3, April 6, 2012, pp. 8 -9. 7 D.12-09-008, p. 16. 8 Richard Klimczak, PG&E, A.14-02-008 Transcript, p. 139, In. 16; p. 141, In. 14. 9 Jd., p. 140, In. 21; p. 141, In. 22.; p. 142, In. 7. 10 Id., p. 140, In. 25. 11 A4NR Opening Brief, A.14-02-008, pp. 27 -29 citing three internal PG&E emails dated September 16, 2013. 5 It had taken more than six months of repeated requests by IPRP chair Chris Wills to obtain PG&E's documentation of its Vs measurements at the OCNPP plant site, and his efforts established that PG&E's Vs assumptions had a 50% greater impact on the seismic hazard calculation than the slip rate on the Hosgri Fault, previously labeled the top uncertainty in the PG&E model. And IPRP Report No. 6 was unsparing in its criticism of PG&E's assumptions:
• To prioritize the main targets of the AB 1632 onshore and offshore geophysical studies, the IPRP earlier asked PG&E for sensitivity analyses of the probabilistic hazards. PG&E's 2011 response ranked uncertainty in the slip rate of the Hosgri Fault as clearly the most significant, with a "calculated ground motion hazard that varies by a factor of nearly 2. "12
• Changing PG&E's base case ground motion characterization of V530 of 1200 m/s to a generic site with a V530 of 760 m/s ("more consistent with other soft rock sites in Califomia"13) "increases the hazard by more than a factor of 3" 14 and changing PG&E's assumed site condition to a generic site with a Vs30 of 1000 m/s "increases hazard by a factor of 2." 15 * "Compared to traditional approaches, the PG&E method resulted in lower ground motion hazard estimates, particularly in the spectral period range important to [Diablo Canyon] ... /1 In contrast, "(a) lower V530 brings the estimated ground motion hazards beyond the original design level when used in typical, state-of-the-practice seismic hazard analysis ... " 16
• The IPRP questioned whether PG&E's approach adequately captured shear wave velocities at different depths beneath the plant: "With only three profiles, it is unlikely that one of them represents the lowest velocity material underlying the plant. Some of the variability seen in the 1978 data may reflect poor quality of the Vs measurements made 35 years ago. Interpretations of that data, however, appear to include unconservative assumptions of velocity in boreholes where no velocity was recorded ... " 17 12 IPRP Report No. 6, p. 17. H Id., p. 3. 14 Id., p. 18. 15 /d. 16 /d., p. 3. 17 Id., p. 6. 6
• Nor was newer data from the ISFSl18 site without problem: "these two profiles do not give consistent Vs measurements at given depths. Considerable variability exists at some depth ranges ... they do not help constrain the lower bound or range of velocity at the plant site." 19 * "A complete consideration of site conditions across the plant footprint requires additional V5 measurements using modern technology to constrain the uncertainty and yield more reliable site V5 values. "20 V. PG&E's 2014 'FINAL' REPORT STONEWALLED IPRP 2013 CRITIQUE. Despite written assurances to the CPUC staff in response to IPRP Report No. 6 that "PG&E understands the scientific findings and will conduct the further studies noted, "21 and internal acknowledgment within PG&E's Geosciences Department that '7he recommended tasks described in the conclusion are reasonable and we plan to address them as part of our own updated site response evaluation,"22 the so-called "final" report submitted to the NRC on September 10, 2014 is willfully unresponsive. As summarized in the IPRP's belated review of the ground motion chapters of the 2014 "final" AB 1632 report:
• IPRP Report No. 6 noted that 'Vs data at the DCPP site indicate significant variability /uncertainty' and that PG&Es estimates "appear to include unconservative assumptions of velocity in boreholes'. IPRP recommended additional studies to determine the V5 beneath DCPP and the variability of V5* 23 (emphasis added) * /PRP Report No. 6 recommended that PG&E 'demonstrate that the low site amplification seen at the DCPP site is due to site effects, not specific to the azimuths and distances traveled by the recorded ground motions at the site from the two earthquakes used' 18 "ISFSI" is an acronym for Independent Spent Fuel Storage Installation. 19 IPRP Report No. 6, pp. 6 -7. 20 Id., p. 6. 21 A4NR Opening Brief, A.14-02-008, p. 30, citing PG&E's October 10, 2013 written response to IPRP Report No. 6. 22 A4NR Opening Brief, A.14-02-008, p. 31, citing September 9, 2013 email from Dr. Norman Abrahamson to Richard Klimczak. 23 IPRP Report No. 9, pp. 2 -3. 7 and 'justify the adequacy of using only two earthquakes to characterize site amplification'. 24 (emphasis added)
• In response, PG&E confirmed in a letter to CPUC (PG&E, 2013) that it would conduct further studies to improve the quantification of site conditions and amplification. These studies would: (1) use new data from on-land exploration geophysics surveys to develop a 30 model of shear wave velocity beneath the plant site; (2) analyze broad band ground motion data and ground motions from small earthquakes to better quantify site-specific amplification terms; and (3) evaluate site amplification using analytical approaches in which seismic waves are propagated through a velocity model. The CCCSIP report addressed the first study as discussed in detail in the remainder of this IPRP report, but not the second and third studies. 25 (emphasis added)
• The high-resolution tomographic model of the area near DCPP presented in the CCCSIP report shows details of the variation in interpreted velocity. Important elements of this detailed model include: relatively low near-surface velocities in areas with remaining natural soil; relatively high near-surface velocities underlying much of the plant itself; highly variable estimates of V530; and irregularly shaped subsurface regions interpreted to have high velocity. 26
• While each of these features of the tomographic model may represent improved understanding of the 'site conditions' at DCPP and may lead to decreased uncertainty in seismic hazard estimates, PG&E has not confirmed the uncertainties in these velocity estimates. Moreover, the CCCSIP report has an extensive discussion of the difficulty of gaining accurate tomographic results at shallow depths, given the constrained receiver locations. 27 (emphasis added)
• Differences between V5 profiles measured in 1978 and profiles derived from the tomographic model may reflect poor data or poor resolution in the 1978 profiles. If the 1978 downhole velocity surveys represent 'ground truth', however, it appears that the tomographic model does not show some shallow high velocity layers up to 50' thick or low velocity layers up to 100' thick. The lack of correspondence between measured Vs 24 Id., p. 3. 2s Id. The "final" AB 1632 Report is also referred to as the "CCCSIP" report, an acronym for Central Coastal California Seismic Imaging Project. 26 /d., p. 4. 27 Id. 8 profiles and Vs profiles estimated from the tomographic model suggests significant uncertainty remains in estimates of "site conditions" at DCPP. 28 (emphasis added)
• The IPRP cannot determine if these differences reflect poor data or analysis in one or both measurements of VS or if both surveys are essentially correct, but have differing levels of spatial resolution. Certainly, the differences between VS profiles from the tomographic model and previouslv measured VS profiles should have been addressed in the CCCSIP report. 29 (emphasis added)
• For the DCPP site, the use of single station sigma with site-specific term appears to be the key factor that brings the deterministic spectra below the original design spectra. 30 (emphasis added)
• While the single station sigma assumption and especially the site term have a significant effect on hazard, the site term is based on the observations of only two earthquakes. 31 As described in IPRP Report No. 6, the IPRP is not convinced that the term' reflects some property of the site that would affect all earthquakes recorded at DCPP. The alternative hypothesis that additional factors related to the particular source or paths of those two earthquakes remains at least as plausible. 32 (emphasis added)
• The CCCSIP report does not include any additional studies to address this issue. The 30 site response analyses proposed by PG&E will not address whether single station sigma model is more reasonable than the ergodic assumption, nor will it reduce uncertainty in the site specific term that is calculated based on two recorded earthquakes. 33 (emphasis added)
• Figure 6 compares deterministic spectra for the CCCS/P sensitivity scenario assuming linked co-seismic rupture of the Shoreline, Hosgri, and San Simeon Faults (M7.3). It shows that deterministic ground motion increases across the spectrum as magnitude for the Shoreline Fault rupture increases from 6. 7 to 7.3. This figure also shows increased ground motion as V530 decreases from 1200 m/s [at the power block foundation level] to 28 Id., p. 5. 29 Id., pp. 5 -6. 30 Id., p. 12. 31 The NRC staff noted this same limitation in its 2012 assessment of PG&E's single-station-sigma adjustment at DCN PP, observing, "Generally a larger number of earthquakes would be needed to develop confidence in the correction factor." RI L 12-01, p. 59. 32 IPRP Report No. 9, p. 12. 33 Id. 9 760 m/s. More significantly, the figure shows, once again, that the most influential factor affecting deterministic ground motion estimates is the single station sigma assumption and the site term. 34 (emphasis added)
• The 30 response analysis cannot, however, address issues associated with the specific term. IPRP previously expressed its concern regarding the adequacy of using only two earthquakes in estimating the site-specific term and made recommendations to gain confidence in the PG&E site-specific approach, including analyzing broad band ground motion data and ground motions from small earthquakes to better quantify the specific term. PG&E has not addressed these recommendations. 35 (emphasis added)
• The "site term" based on two recorded earthquakes may represent other factors, rather than site conditions. IPRP is not convinced that this factor is adequately constrained for use in ground motion calculations.36 (emphasis added) The IPRP, impeded from performing its duties by PG&E's extended embargo from mid-2013 until the AB 1632 report was "finalized" in September 2014, was also critical of certain aspects of PG&E's seismic source characterization when it eventually gained access to the document. IPRP Report No. 8 is particularly pointed in its assessment of PG&E's analysis of onshore faults: 34 Id.
• The IPRP is not convinced that the interpretations of the down-dip extensions of faults are well constrained, even in the case of well-documented surface faults. Similarly, faults interpreted from the seismic sections, but not corroborated by surface mapping, (e.g. faults interpreted between the San Miguelita and Edna faults) are possible, but are by no means unique interpretations of the data. Overall, the IPRP is not convinced that projections of faults beyond the very shallow subsurface represented unique interpretations of the data.37 (emphasis added)}
• Proiections of faults to depth in 'basement' rocks of the Franciscan complex appear to be even more problematic. As discussed at the IPRP meeting on November 17, 2014, the Franciscan complex is known to be a mixture of different rock types pervasively 35 /d., p. 15. 36 /d. 37 IPRP Report No. 8, p. 5. 10 sheared at a variety of scales and is not expected to produce reflectors that are extensive over broad areas. The majority of seismic sections, (e.g. AWD line 150 as presented on Chapter 7, Figure 5-25) show prominent, continuous reflectors at relatively great depths in material that is assumed to be bedrock of the Franciscan complex. 38 (emphasis added)
• Most deep reflectors shown on Figure 5-25, and in many other sections are arranged in groups of concave-upward, gently curved reflectors. These reflectors are interpreted in the CCCSIP report as representing geological structure. The IPRP, however, regards this pattern of concave-upward sets of reflectors as difficult to explain geologically, but not difficult to envision as artifacts from the data processing. If the continuous reflectors in Franciscan complex bedrock are artifacts of data processing, rather than representing geologic structure, then the seismic reflection survevs provide no constraint on the down-dip geometry of faults in the Franciscan Complex. 39 (emphasis added)
• The Los Osos fault, in particular, is entirely within Franciscan Complex rocks from very shallow depths. If the reflection surveys do not show real geologic structure along the down-dip extension of this fault, then dip of the fault remains essentially unconstrained. 40 (emphasis added)
• Since the Franciscan complex is known to be a mixture of different rock types pervasively sheared at a variety of scales, continuous, gently dipping layers are not expected. The overall arrangement of the gently dipping 'reflectors' also raises questions that are not addressed in the report. In several sections, the arrangement of reflectors does not resemble a cross-section of folded or faulted rock. The pattern of concave-upward sets of reflectors seen in many sections does not have an obvious geological explanation, leading the IPRP to question whether they represent real geologic structure.41 (emphasis added}
• Even if all reflectors shown in the seismic sections are images of geologic features, the interpretations of various faults are inconsistent and not unique: 1) In many cases, faults are interpreted based on a series of truncated reflectors, but are shown to pass through other reflectors that are not truncated; 2) In some seismic sections, it appears that additional faults are permitted by the data. It is not clear how the stated interpretation methodology allowed the interpretation team to draw some faults and not others; and 3) Alternate interpretations of the dip of most faults are possible. 42 (emphasis added) 38 Id., p. 6. Jci Id. 40 Id. 41 Id., p. 7. 42 Id., pp. 7 -8. 11
• This concern applies to the dip of the Los Osos fault. Alternate dips, including relatively low-angle dips, of the Los Osos fault appear to be possible through sections 138-149 and 150 as shown on Figures 5-24 and 5-25 of the CCCSIP report. The reduction in uncertainty in seismic hazard depicted on the 'tornado diagram' for dip of the Los Osos fault appears to be based on the CCCSIP report conclusion that the new data precludes low-angle dips. The IPRP does not concur that low-angle dips are precluded by this new data and therefore does not believe that these studies have resulted in reduced uncertainty in seismic hazard related to this parameter. 43(emphasis added)
• Although surface faults recognized to date appear to be consistent with strike-slip faulting on the Shoreline fault, rather than thrusting on the SLRF, the possibility of thrust faults in the subsurface is not ruled out by on-land seismic survey data. The interpretation of the ONSIP data is far from unique and allows one to interpret a low angle reverse fault at the proposed location, contrarv to what is stated in the CCCSIP report (p.70 Figure 6-54}. The CCCSIP interpretation criteria are not clearly defined and do not appear consistent in terms of selections made when seismic reflections are truncated. 44 (emphasis added) IPRP Report No. 8 emphasizes the curtailed nature of its after-the-fact review, 45 and points out that proper evaluation of PG&E's seismic data acquisition and processing would require the retention of outside consulting services-an authority expressly granted to the IPRP by D.10-08-00346 and D.12-09-008,47 and first promised at the IPRP's initial meeting on August 31, 2010, 48 but still unfulfilled as of the date of this Protest. Unsurprisingly, it was the very fear of this predictable IPRP focus on data acquisition and processing that dominated PG&E management's 2013 internal "risk" evaluation of a scenario labeled "IPRP Review": 43 Id., p. 8. 44 Id., p. 10. 45 "IPRP review of the tectonic model is based on the CCCSIP report and presentation. The IPRP has not had time, to review the seismic data processing in detail." IPRP Report No. 8, p. 7. 46 D.10-08-003, p. 11. 47 D.12-09-008, p. 23. 48 IPRP Report No. 1, p. 5. 12 IPRP recommends additional processing of data or interpretations after their review of project results. The project results and conclusions are to be provided to the Independent Peer Review Panel (IPRP) as a condition of authorized CPUC funding for this project. They could recommend additional processing methods be applied or other interpretation techniques be utilized. The IPRP make-up does not have members who are experienced in processing and interpretation, but they could seek an independent review by others. 49 (emphasis added) IPRP Report No. 9 also describes more recent obstruction to its review of PG&E's ground motion assumptions: Following the public meeting on January 8, 2015, the IPRP had a number of additional questions regarding the velocity model described in Chapter 10 and requested an additional meeting with PG&E. PG&E declined to meet again with IPRP. As a result, this report only covers aspects of those models described in the CCCS/P report and the public meeting. 50 (emphasis added) PG&E's successful strategy to circumvent meaningful IPRP review, originally formulated in 2013 and implemented as a reaction to the devastating IPRP Report No. 6, culminated with submittal of a deeply flawed 'Jina/" AB 1632 Report to the NRC in 2014. As of the date of this Protest, A4NR has had insufficient time to determine the degree to which adulterated assumptions from the inadequately reviewed AB 1632 Report have driven the conclusions of the LTSP's recent SSHAC Report. The cynical fashion in which PG&E's recent publicity offensive has invoked the hamstrung IPRP review to promote the rosy conclusions of the SSHAC Report leaves little room for doubt: 49 A4NR Opening Brief, A.14-02-008, p. 4, quoting a March 28, 2013 submittal to PG&E's Executive Project Committee by Ed Halpin, Jeff Summy, and Richard Klimczak. so IPRP Report No. 9, p. 2. 13
• Independent experts also included an evaluation of the advanced seismic studies recently performed near Diablo Canyon, as well as feedback on the research provided from a state-appointed independent peer review panel. 51 (emphasis added}
• Their work also utilized insight gained from the advanced seismic studies recently completed near Diablo Canyon. In addition, input on the advanced seismic studies provided bv the California Public Utilities Commission's Independent Peer Review Panel was considered in the seismic hazard re-evaluation process. 52 (emphasis added} * [Th is] work also included an evaluation of the advanced seismic studies recently performed near Diablo Canyon, as well as feedback on the research provided from a state-appointed independent peer review panel. 53 (emphasis added} VI. DR. BLAKESLEE SPOTLIGHTS PG&E's DECEPTIVE PATTERN. Leave it to the author of AB 1632, Dr. Sam Blakeslee, the former Exxon geophysicist who served as Republican Minority Leader of the California State Assembly, to assess the degree to which the $64.25 million ratepayer-funded seismic studies have been subverted. As Dr. Blakeslee observed in December 3, 2014 testimony to the U.S. Senate Environment and Public Works Committee, over several decades PG&E has discovered more faults in close proximity to the plant, attributed greater capability to the faults which it has acknowledged, yet consistently proclaimed the seismic risk at the plant to be diminishing: "The potential earthquakes affecting the plant have increased with each major study. But what's equally striking is that the shaking 51 "Confirming Diablo Canyon Plant's Safety," Ed Halpin, Lompoc Record, March 14, 2015. 52 "Seismic and tsunami safety a priority for Diablo Canyon," Ed Halpin, San Luis Obispo Tribune, March 19, 2015. sJ "Op/ed: PG&E exec answers critics, says Diablo Canyon is safe, secure," Ed Halpin, Pacific Coast Business Times, March 20, 2015. 14 predicted by PG&E for these increasing threats has systematically decreased as PG&E adopted less and less conservative analytical methodologies ... " 54 Dr. Blakeslee was especially critical of PG&E's debased '1inal" AB 1632 Report: ... in a seeming contradiction, rather than finding that larger or closer faults produce greater shaking and therefore a greater threat, PG&E argues in the Report that ground motion will be lower than the levels previously estimated. In other words, these newly discovered and re-interpreted faults are capable of producing shaking that exceeds the shaking from the Hosgri, yet that shaking threat would be much reduced from prior estimates. Though discussed only in passing in the Report, the reason for this seeming contradiction is quite important when assessing whether or not the plant is safe or whether it is operating within its license conditions. The reason the earthquake threat purportedly went down when new faults were discovered is because the utility adopted significant changes to the methodology utilized for converting earthquakes (which occur at the fault) into ground motion (which occurs at the facility). This new methodology, which is less-conservative than the prior methodology, essentially "de-amplifies" the shaking estimated from any given earthquake relative to the prior methodology used during the licensing process. 55 PG&E's "final" AB 1632 Report artfully avoids an apples-to-apples comparison which would isolate the influence of its continuously evolving ground motion prediction methodology. The charts on pages 13 -15 of the Technical Summary, attached to this Protest as Appendix A, purport to contrast the spectra derived from the AB 1632 studies against the 1977 Hosgri evaluation and the 1991 LTSP analysis. Neglecting to reveal the radically different methods for predicting ground motions between cases has the same power of deception as assembling a financial spreadsheet mixing different vintages of dollars without disclosure. To the extent 54 Written Statement by Sam Blakeslee, Ph.D, to the Senate Committee on Environment and Public Works, December 3, 2014, p. 3. Dr. Blakeslee's complete statement is accessible at http://www. e pw. senate .gov Ip u b Ii c/i nd ex. cf m? Fuse Action= Files. View& Fi leS to re id =4 2 d07 68 2-cad 9-4 9f 4-b bf 1-fc975 7f624c9 55 /d., p. 5. 15 that PG&E intended anyone to rely upon the misrepresentations-by-omission contained in these charts, and such reliance were to occur, the common law uses a certain f-word to describe such conduct. VII. PG&E's POST-CCCSIP CONTEMPTUOUS DISCLOSURE. Having successfully circumvented the IPRP before submitting its "final" report to the NRC, and choosing to absorb the criticism of IPRP Report No. 8 without response, the PG&E Geosciences Department could not resist engaging in its own form of end-zone dance at the January 8, 2015 meeting of the IPRP. With peculiar aplomb, Dr. Norman Abrahamson blithely distributed a new hazard sensitivity chart, attached to this Protest as Appendix B, and acknowledged that the six highest ranked uncertainties (each relating to earthquake-induced ground motions at the plant) had never before been presented to the IPRP. Despite admitting that PG&E's void of site-specific ground motion data dominates Diablo Canyon's probabilistic seismic hazard, Dr. Abrahamson nonchalantly suggested this deficiency be addressed in PG&E's 2025 update. There was no mention of the staggering difference in magnitude between the six newly identified uncertainties and the ones which had been selected for the AB 1632 studies. 56 His unmistakable message: having feasted on a $64.25 million authorization for ratepayer-funded studies, we never addressed the most significant issues or even told you what they were. But now we've run out the clock. Too bad, chumps. 56 Dr. Abrahamson's discussion of the new hazard sensitivity chart runs from 1:51:27 to 2:03:25 in the video of the January 8, 2015 IPRP meeting, accessible at http://youtu.be/hXu vnSgxMU 16 VIII. TO LIVE OUTSIDE THE LAW YOU MUST BE HONEST. The light-handed oversight previously afforded PG&E in the conduct of its AB 1632 studies appears to be a legacy of the Commission's discredited, pre-San Bruno voluntary compliance era. As Executive Director Paul Clanon memorably testified to a California Senate committee, "That can be characterized as 'self-reporting,' but a better way to look at it is creating a safety culture at the utility. "57 He later explained that, in lieu of fines, "a better way to ensure safety is to make sure that a utility sees violations on its own has every incentive to report them. "58 As Mr. Clanon told a post-explosion community meeting in San Bruno, fines might "discourage the utilities to come forward when they see a problem. A utility doesn't want their pipelines to be unsafe. "59 A4NR does not contend that PG&E wants DCNPP to be seismically unsafe. Rather, the accumulated record of PG&E's performance of its AB 1632 seismic studies documents a furtive, thumb-on-the-scale approach designed primarily to quell public apprehension and forestall pressure to close the plant. PG&E has received special dispensation from the NRC since October 12, 2012 to defer application of the Double Design Earthquake ("DOE") standard to the Shoreline Fau It until submittal of the DCN PP SSHAC analysis --despite the N RC' s acknowledgment that "using the DOE as the basis of comparison will most likely result in the Shoreline fault and the Hosgri earthquake being reported as having greater ground motion" 57 "PG&E Hammered Over Safety Issues," San Mateo Times, October 19, 2010. 511 "State's gas pipeline inspections found to lag," San Francisco Chronicle, November 14, 2010. 59 "San Bruno blast victims skeptical of PUC oversight," San Francisco Chronicle, December 8, 2010. 17 than the plant's Safe Shutdown Earthquake. 60 This remarkable prediction was repeated by Dr. Cliff Munson, an NRC seismologist, in testimony to a June 19, 2013 California Energy Commission workshop. 61 The indifference with which California state agencies have, at least publicly, accepted this revelation has been alarming but the financial bottom line is undeniable: significant seismic retrofit requirements seem likely to be required. 62 A4NR does not expect the CPUC to involve itself in questions of the seismic licensing basis of DCNPP or the prudence of the manner in which the NRC has addressed the seismic Ii censi ng basis issue. 63 Instead, A4N R expects the Commission to be d ii igent in its application of traditional ratemaking authority to protect California's economic interest and electricity reliability interest in accurately understanding the seismic challenges facing the plant. The Commission would be derelict in meeting this responsibility by relying exclusively on PG&E's good faith or commitment to scientific objectivity. 50 Letter to Edward D. Halpin from Joseph M. Sebrosky, NRC Senior Project Manager for Plant Licensing Branch IV, Division of Operating Reactor Licensing, Office of Nuclear Reactor Regulation, October 12, 2012, accessible at http://pbadupws.nrc.gov/docs/ML1207 /M L120730106.pdf 61 Lead Commissioner Workshop on California Nuclear Power Plant Issues. Docket No.13-IEP-lJ, June 19, 2013, Transcript. p. 89, accessible at http://www.energy.ca.gov/2013 energypolicy/documents/2013-06-19 workshop/2013-06-19 nuclear workshop tra nscript.pdf 62 The severity of any such requirement is suggested by PG&E's 2012 submittal to the NRC of a 331-page list of DCNPP deviations from the "new plant" criteria Dr. Munson testified will be applied: ""The thing I wont to emphasize is that the hazard evaluations are based on current practices for new reactors." Id., p. 81. PG&E' s 331-page list of deviations is accessible at http://pbadupws.nrc.gov/docs/ML1134/ML11342A238.pdf The Union of Concerned Scientists reported in 2013 that. of the 100 reactors currently operating in the U.S .. the two at Diablo Canyon top the NRC's list as being most likely to experience an earthquake larger than they are designed to withstand, using NRC data to calculate the probability of such an event as more than 10 times greater than the nuclear fleet average. "Seismic Shift: Diablo Canyon Literally and Figuratively on Shaky Ground," Union of Concerned Scientists, November 2013, p. 7, accessible at http://www. u csu sa .o rg/ sites/ d efa ult/files/I ega cy/ assets/ d ocu me nts/ nuclear power Id ia b lo-canyon-ea rthq ua ri sk. p df 18 PG&E is the only NRC power plant licensee in the history of the commercial nuclear power industry to face criminal indictment for safety-related violations by the U.S. Department of Justice. While the 27 safety-related felony counts in PG&E's federal grand jury indictment are focused on the company's gas division, it strains credulity to believe that DCNPP has been somehow immunized from the corporate culture rot that recently prompted Commission President Michael Picker to acknowledge during a California Senate oversight hearing that, "I think there's a very clear case that in some places, the utility did divert dollars that we approved for safety purposes for executive compensation."64 And the obstruction of justice felony count which leads PG&E's federal indictment emphatically addresses management as a whole: "On or about September 10, 2010, and continuing through on or about September 30, 2011, in the Northern District of California, the defendant, PACIFIC GAS AND ELECTRIC COMPANY, did corruptly influence, obstruct, and impede, and did endeavor to influence, obstruct, and impede the due and proper administration of the law under which a pending proceeding was being had before a department and agency of the United States ... "65 (emphasis added) Although perhaps not a matter of familiarity to utility regulators, the term "RAP sheet" is derived from the Federal Bureau of Investigation's Record of Arrests and Prosecutions. Actual conviction is not a prerequisite. A4NR is unaware of any other California electric utility with a RAP sheet. While PG&E is certainly entitled to its day(s) in court to defend itself from the federal charges, its status as a criminal defendant and the nature of its alleged crimes should 64 President Picker's statement is at 36:56 of the video of the March 25, 2015 oversight hearing conducted by the California Senate Committee on Energy, Utilities and Communications, accessible at http://calchannel.granicus.com/Med ia Player.php ?view id= 7&clip id=2682 65 United States of America v. Pacific Gas and Electric Company, United States District Court for the Northern District of California, Case 3:14-cr-00175-THE, Superseding Indictment, July 29, 2014, p. 18. 19 discourage the Commission from extending any presumption of veracity to the representations in PG&E's AB 1632 Report without corroboration by the most rigorous scrutiny. IX. WHY A4NR PROTESTS. Building upon key decisions made and implemented by PG&E in 2013, the utility intensified its efforts in 2014 to subvert what was originally conceived by the Commission as a robust re-evaluation of DCNPP's seismic setting. If PG&E is allowed to recover the costs of such subterfuge, the effect on A4NR and all PG&E customers will be electricity rates rendered both unreasonable and unjust by Commission reward of unmistakable perfidy. The consequences for A4NR members (and others) living in communities near the plant stemming from unknowing acceptance of PG&E's defective seismic analysis could, in some circumstances, be much worse than that -with incalculable financial impact on California. A4NR requests evidentiary hearings and will conduct discovery and sponsor testimony elaborating on the facts contained in this Protest, as well as the extent to which PG&E's LTSP and SSHAC expenditures in 2014 were similarly tainted. Assuming timely responsiveness by PG&E to legitimate discovery requests, A4NR has no objection to the schedule proposed in PG&E' s application. The undersigned will be the A4NR's principal contact in this proceeding, but A4NR also asks that the following two individuals be placed in the "information only" category of the Service List: Rochelle Becker rochel le@a4n r .org 20 David Weisman david@a4nr.org Date: April 3, 2015 21 Respectfully submitted, By: /s/ John L. Geesman JOHN L. GEESMAN DICKSON GEESMAN LLP Attorney for ALLIANCE FOR NUCLEAR RESPONSIBILITY APPENDIX A PG&E SPECTRA CHARTS FROM CCCSIP REPORT A-1
• 1 :i r: .. ;. *J. CJ) -c:: 0 2 1.5 .... Q) Q) (.) (.) <{ 1 u (]) a. CJ) 0.5 1977 HE spectrum 1991 LTSP/SSER34 spectrum Page 13of15 CCCSIP Report Technical Summary PB -Linked Hosgri and San Simeon (M 7.3) PB -Los Osos (M 6.7) PB -San Luis Bay (M 6.4) PB -Shoreline (M 6.7) 1977 HE spectrum extended to 0.5 Hz 0 0.1 10 Frequency (Hz) 100 lhe 84th Pwcenlle Detennlnlstlc Ground Motions ii for Four Fault Scenarios Compared to the 19ll ti ,. Hosgrl Earthquake (HE) and the 1991 L 1SPISSER '= 34 Spectra tor the DCPP Power Block CCCSIP REPORT ;.; ! Figure 1-1 l! u 2 -O'l -c 1.5 .... Q,) 0 <( l'C .... 0 Q,) a. (/) 1 0.5 1977 HE spectrum Page 14ofl5 CCCSIP Report Technical Summary 1991 LTSP/SSER34 spectrum TB* Linked Hosgri and San Simeon (M 7.3) TB
• Los Osos (M 6. 7) TB* San Luis Bay {M 6.4) TB
• Shoreline (M 6. 7) 1977 HE spectrum extended to 0.5 Hz 0 ...._ _____________________________________ --.( 0.1 1 10 100 Frequency {Hz) The 84th Pen:.entle Detennlnlsdc Ground Motions for Four faajt Scenarios COlllpared to the 1977 Hosgri Emttlquake (HE) and the 1991 L TSPISSER 34 Spectra for the DCPP Turbine Buldlng CCCSIP RB'ORT Figure 1-2 ..

.9 c 0 2 1977 HE spectrum 1991 LTSP/SSER34 spectrum Page 15of15 CCCSIP Report Technical Summary PB -Shoreline Linked to Hosgri & San Simeon (M 7.3) TB -Shoreline Linked to Hosgri & San Simeon (M 7.3) 1977 HE spectrum extended to 0.5 Hz ..... CV a; a. CJ) 0.5 0.1 10 Frequency (Hz) 100 lhe Nth Pwcentle Detenoinistic Ground llotions for Joint Shorelne and Hosgd-San Slllleoo Fault Rupblre Cotnpared to the 19n Ho$ild Earthquake and the 1991 L lSPJSSER 34 Spectra for the DCPP PoMr Block and T..t>lne Buldln9s CCCSIP REPORT Padlic Ga *d Bldlic C-.-y Figure 1-3 . . APPENDIX B PG&E LATE-DISTRIBUTED HAZARD CHART B-1 Hazard Sensitivity 5 Hz, PSA = 2g Non-Ergodic Path -+-----*:--+-----------+-Non-Ergodic Source -+------__. _ Median from GMPE Site Amplification _,__ ............. SigmaSS Model -+--------+-___...---------r---*-Time Dependent hazard -+--------+-----Hosgri Slip Rate -i--------1----:::-_...---+-__.-----1 Hosgri Dip -+-------1----___.=..,..'-'-.,..,._--+-=----1 Shoreline Slip Rate Hosgri -San Simeon Step Over Los Osos Dip ............... Los Osos Slip Rate -+-------+-----**+ .. -+-. ------1 -Shoreline and Hosgri Linking ----.-----1 Los Osos Sense of Slip -**------+-------dJ Shoreline Segmentation .... ..:dJ Shoreline Southern End ....... * "-" 0.01 0.1 1 10 Hazard Ratio (not GM ratio) :..J SSC 2011 ., SSC 2014 /;},. GMC 2014 + Non-Ergodic GMC ALLIANCE FOR NUCLEAR RESPONSIBILITY May 12, 2015 Nicholas DiFrancesco Office of Nuclear Reactor Regulation njd2@nrc.gov PO Box 1328 San Luis Obispo, CA 93406 (858) 337-2703 (805) 704-1810 www.a4nr.org transmitted via email Re: April 28, 2015 WEBCAST PUBLIC MEETING TO DISCUSS THE SEISMIC HAZARD REEVAUATION RESPONSE BY PACIFIC GAS AND ELECTRIC COMPANY RELATED TO THE FUKUSHIMA DAl-ICHI NUCLEAR POWER PLANT ACCIDENT Dockets Nos. 05000275 and 05000323

Dear Mr. DiFrancesco:

I regret that schedule conflicts prevented the Alliance for Nuclear Responsibility ("A4NR") from participating in the April 28, 2015 public meeting. Having reviewed the archived video webcast and the reporting of the meeting in the San Luis Obispo Tribune ("NRC reaffirms Diablo Canyon's seismic safety," April 28, 2015). I am submitting the following written concerns pursuant to NRC guidelines for Category 1 public meetings. I firmly hope that the NRC staff will painstakingly review each of the focused criticisms in the attached three formal reports from the California Public Utilities Commission's Independent Peer Review Panel ("IPRP"). The IPRP, chaired by the California Geological Survey, was established to review PG&E's performance of the ratepayer-funded AB 1632 Seismic Studies. As explained in the attached A4NR Protest summarizing the IPRP's most pointed concerns, PG&E has largely evaded such review -but not before being called out by the IPRP for exceptionally dubious modeling assumptions concerning the soil conditions beneath the plant and the sparseness of relevant site-specific data to support its application of GMPEs. I was pleased to see some interest in this area by NRC staff on the webcast, but the ease with which the NRC staff and its consultants have previously been taken in by PG&E bluster (e.g., is there no chagrin over how quickly the AB 1632 data shredded PG&E's reduced length, no-joint-rupture dogma about the Shoreline Fault which had been embraced by RIL-12-01 just months earlier?) does not inspire confidence. PG&E's self-assurance in its ability to repeat this hat-trick with the NRC staff is manifest in its abandonment of a regulatory commitment to perform the expedited interim seismic evaluation otherwise required by its March 12, 2015 submittal. The Union of Concerned Scientists reported in 2013 that, of the 100 reactors then operating in the U.S., the two at Diablo Canyon top the NRC's list as being most likely to experience an earthquake larger than they are designed to withstand, using NRC data to calculate the probability of such an event as more than 10 times greater than the nuclear fleet average. PG&E is also the only NRC power plant licensee in the history of the commercial nuclear power industry to face criminal prosecution for safety-related violations by the U.S. Department of Justice. While 27 of those felony counts relate to the company's gas division, the obstruction of justice count which leads the indictment is emphatically company-wide, alleging that management: "did corruptly influence, obstruct, and impede, and did endeavor to influence, obstruct, and impede the due and proper administration of the law under which a pending proceeding was being had before a department and agency of the United States ... " Those two considerations argue for a heightened level of diligence by the NRC staff in reviewing PG&E's March 12, 2015 submittal. PG&E's braggadocio at the April 28, 2015 public meeting about reducing its Core Damage Frequency estimates from 3.7 down to 2 in the 3-8.5 Hz range carries a whiff of Bernie Madoff. The NRC staff needs to carefully address, point by point, each of the IPRP criticisms (among others) before it can begin to dislodge the rubberstamp image it suffers among many Californians. Sincerely, /s/ Rochelle Becker Executive Director Roche I le@a4n r .org cc: M ieha el.Ma rkley@nre.gov; Rieha rd.PI a sse@nre.gov; M iehael. Wentzel@nre.gov; Wayne.Walker@nre.gov; Ryan.Alexander@nre.gov; Thomas.Hipsehman@nre.gov; Bi 11.Maier@nre.gov; Jon .Ake@nre.gov .; Yong. Li@nre.gov; Ni lesh. Choksh i@nre.gov; Jim .Xu@nre.gov; Kam a I. Ma noly@nre.gov; P .Y.Chen@nre.gov; John. Bu rke@nre.gov; Clifford.Munson@nrc.gov; Gerry.Stirewalt@nrc.gov; Timothy.Lupold@nre.gov; jstamatakos@swri.org; Chris.Miller@nrc.govi Bill.Dean@nre.gov Brian. Holi a n@nre.gov; Marc. Da pas@nre.gov; Michael .Johnso n@nre.gov Attachments: IPRP Reports 6, 8, and 9; A4NR A.15-02-023 Protest, April 3, 2015 Sent:27 Mar 2015 16:5 I :57 +0000 To:Jackson, Diane;Munson, Clifford;Ake, Jon Cc:Hill, Brittain;Shams, Mohamed;Vega, Frankie

Subject:

Inquiry for Comment: Windows for WUS Public Meetings and Draft Agenda Cliff, Jon, Diane, Any thoughts on windows for the WUS public meetings? I need to forecast a guess to R-IV and licensee stakeholders. Working to manage expectations. Also, is an outline of a potential agenda for Diablo. I plan to discuss with licensee and R-IV next week and notice around April 2. Proposal for enhancement Diablo Canyon -April 28 Columbia -mid-May Palo Verde -early June Agenda Diablo Agenda 1. NRC a. General Background on 2.1 Seismic b. Technical discussion on goals and expected outcome c. Intro of seismic hazard PSHA methods and use for licensing of new plants I SSH AC 2. Licensee a. SSHAC effort b. Sources, c. GMM d. Technical Issues e. Discussions f. Interim Actions 3. Break [to discuss] 4. NRC a. Discussion of Interim actions and approach b. Technical wrap-up-next steps c. Public Questions Regards, Nick Project Manager -Seismic Walkdowns and Re-evaluations U.S. Nuclear Regulatory Commission Office of Nuclear Reactor Regulation Japan Lesson Learned Project Directorate n icho las.difrancesco@nre.gov I Tel: (301} 415-1115 Wyman, Stephen From:Wyman, Stephen Sent: 17 Mar 2015 19:52: 17 +0000 To:Singal, Balwant Subjeet:Palo Verde FSAR Balwant, Can you please confirm for me the latest Rev of the FSAR for Palo Verde? I currently find Rev 16 dated June 2011 on the network. (Y:/CDIMAGES/FSAR) The staff has a question regarding their seismic design basis as it related to the recently submitted seismic hazard report. Thanks, Steve Stephen M. Wyman USNRCINRRIJLDIHMB Office: 0-13G9 MS: 0-13C5 301-415-3041 (Voice) 301-415-8333 (Fax) Stephen.Wyman@nrc.gov Sent:24 Apr 2015 14:32:36 +0000 To:Munson, Clifford;Stieve, Alice Cc:Jackson, Diane;Devlin-Gill, Stephanie;Hill, Brittain

Subject:

Palo Verde Source Information for: SSHAC Documentation from PPRP-IT Team Attachments:SSC SSHAC Documentation of PPRP-TI-Team lnteraction.pdf Cliff. Alice, Stephanie, Please let me know if this is the missing piece. They have this one file on the SSC in the reading room. Thanks, Nick From: Munson, Clifford Sent: Tuesday, April 21, 2015 4:14 PM To: Difrancesco, Nicholas; Ake, Jon Cc: Jackson, Diane; Shams, Mohamed; Vega, Frankie; Graizer, Vladimir; John Stamatakos <jstam@swri.org> (jstam@swri.org); Hill, Brittain; Seber, Dogan; Vega, Frankie; Stirewalt, Gerry

Subject:

RE: DCPP, Palo Verde, and Columbia Audit Information: SSHAC Documentation from PPRP-IT Team Importance: High Nick, We took a quick look at the contents of the information for DCPP and PVNGS. The DCPP folder contains the PPRP-TI correspondence and interactions on the source model and ground motion model SSHACs. However, the PVNGS only has the ground motion model SSHAC PPRP-TI team material and not for the Source model. Please let us know when we can get the source model PPRP-TI team documentation. Thanks, Cliff From: Difrancesco, Nicholas Sent: Tuesday, April 21, 2015 1:25 PM To: Munson, Clifford; Ake, Jon Cc: Jackson, Diane; Shams, Mohamed; Vega, Frankie; Graizer, Vladimir; John Stamatakos <jstam@swri.org> (jstam@swri.org); Hill, Brittain; Seber, Dogan; Vega, Frankie; Stirewalt, Gerry

Subject:

DCPP, Palo Verde, and Columbia Audit Information: SSHAC Documentation from PPRP-IT Team Folks, Please control distribution to the designated review team member for the following references. Following your audit review, please advise if information reviewed should be docketed to support development of the hazard staff assessment or RAls. DC Audit Information S:\Diablo Canyon R2.1 Seismic lnformation\SSHAC Documentation of PPRP-TI Team Palo Verde Audit Information S:\Palo Verde R2.1 Seismic lnformation\SSHAC Documentation of PPRP-TI Team Columbia Information is on ePortal (PM action to work through access controls). Also, licensee plans to work with PNNL to post information on public website. Thanks, Nick From: Soenen, Philippe R [22] Sent: Tuesday, April 21, 2015 10:49 AM To: Difrancesco, Nicholas Cc: Jahangir, Nazar

Subject:

DCPP information on Certrec Nick, We have uploaded the PPRP information onto Certrec IMS and granted access to Vladimir Grazier, John Stamatakos, and yourself. Here is how you get to the PPRP information in Certrec:

• Login to ims.certrec.com
• Click on "Inspections"
• Set status to "In Progress" and Plant to "Diablo Canyon"
• Click "Search" button.
• Click link to "Self-Assessment I Audit-Review of PPRP Comments and TIT Resolution"
• Click on the "NRC Requests" tab
• Click on what you would like to see. Please let me know if you have any questions. Regards, Philippe Soenen Regulatory Services Office -805.545.6984 Cell -805.459.3701 PG&E is committed to protecting our customers' privacy. To learn more, please visit http://www.pge.com/about/company/privacy/customer/

LCI Mr. Ronald Gaydos Project Manager Engineered Equipment & Major Projects Westinghouse Electric Company 1000 Westinghouse Drive CWHQ3-41 OM Cranberry Township, PA 16066

Subject:

Additional Documentation for the PVNGS SSC Report Mr. Gaydos, I .l'tlis Consultants I nh*rnational. Im*. 27-1-11 1,.>urn..:y H'.>ad. S11it<.: Vakni:ia. (;\ 91 (li<*l) lax (Md) April 17, 2015 Lettis Consultants International, Inc. (LCI) is pleased to submit this additional documentation associated with the Palo Verde Nuclear Generating Station (PVNGS) Seismic Source Characterization (SSC) Report (Revision 0, dated February 2015). This additional documentation satisfies deliverable requirements for Task 1, as described in Project Impact Notice (PIN) No. 8 for Scope Changes to the Arizona Public Service (APS) 2.1 Seismic Hazards Evaluation (SHE) Project. The U.S. Nuclear Regulatory Commission (NRC) requested that APS provide additional information detailing the interactions between the Participatory Peer Review Panel (PPRP) and the Technical Integrator (Tl) Team. The requested information is provided in the three attachments that accompany this letter:

• Attachment 1: PPRP Comments on the Project Plan and Tl Team Responses.
• Attachment 2: Formal Correspondence Between the Tl Team and the PPRP.
• Attachment 3: PPRP Comments on the Draft SSC Report and Tl T earn Responses. Please do not hesitate to contact us with any questions. Sincerely, Lettis Consultants Inc. \' * \ I I \ ,___,. \) \ . t. v* . i \....( ' J
• J Ross Hartleb Project Manager LCI Project No. 1056.001 April 17, 2015 ATTACHMENT 1 Participatory Peer Review Panel (PPRP) Comments on the Project Plan and Technical Integrator (Tl} Team Responses Senior Seismic Hazard Analysis Committee (SSHAC) Level 3 Seismic Source Characterization Palo Verde Nuclear Generating Station (PVNGS) This attachment contains technical comments made by the PPRP on the initial issue of the Project Plan dated January 17, 2013, and provides a record of the Tl Team response to each comment. Comments were provided to the Tl Team on January 23, 2013. The Plan Plan was revised and reissued on February 19, 2013. April 17, 2015 PVNGS SSC Additional Documentation Attachment 1, Page 1 of 4 COMMENT-RESPONSE LOG PALO VERDE SSHAC LEVEL 3 PROJECT PLAN PPRP COMMENTS AND Tl TEAM RESPONSES No. Date Location in Project PPRP Comment Summary of Revisions to Project Plan Received Plan 1 1/23/2013 "Introduction" paragraph Is this word (i.e., "adequately") used in Text revised to indicate that the term "adequately" 3, page 2. this context in the SSHAC references? I is used in this context by NRC (NUREG 2117). hope so, as it is a soft term that lacks Specifically, text revised to read, "Moreover, the specificity. NRC (2012a, p. 89) indicates that successful implementation of the SSHAC Level 3 process 'implies a complete and well-documented hazard study that contributes to regulatory assurance that the hazard has been robustly evaluated and that the associated uncertainty has been adequately captured."' 2 1/23/2013 "Objective of the Study" CBR and TOI are defined in the previous Text revised as suggested. paragraph 1, page 2. paragraph and so do not need to be defined again. 3 1/23/2013 "Description of SSHAC SSHAC has already been defined; Text revised as suggested. Methodology" paragraph SSHAC didn't publish the methodology, 1, page 2. the NRC did. I suggest reorganizing the sentence along the lines of "In 1997 the SSHAC methodology was published by the NRC as NUREG ... " 4 1/23/2013 "Description of SSHAG Is this phrase (i.e., "reasonable The term "reasonable regulatory assurance" is Methodology" paragraph regulatory assurance") from the NRG? replaced by "increased regulatory assurance", 3, page 3. You might put it in quotes and cite the which is directly quoted from NRG (NUREG reference. 2117). 5 1/23/2013 "Selection of SSHAC As noted in my earlier comment, is this The use of "adequately" here is consistent with Level" paragraph 1, (i.e., "adequately") NRC usage? NRC (NUREG 2117, p. 89). See response to page 3. comment #1. No change to text. 6 1/23/2013 "Palo Verde SSC Project I tried to clarify was seemed to me to be Text revised as suggested. Organization" paragraph somewhat awkward language in the 4 (definition of "Project paragraph. Sponsor"), paqe 5. April 17, 2015 PVNGS SSC Additional Documentation Attachment 1. Page 2 of 4 COMMENT-RESPONSE LOG PALO VERDE SSHAC LEVEL 3 PROJECT PLAN No. Date Location in Project PPRP Comment Summary of Revisions to Project Plan Received Plan 7 1/23/2013 "Palo Verde SSC Project Does this (i.e., "State agencies"} mean Text revised to specify "State of Arizona Organization" paragraph Arizona? Maybe should say so. Might agencies." 16 {definition of "Outside other states be interested in sending Observers"), paqe 7. representatives? 8 1/23/2013 "Palo Verde SSC Project Suggest replacing "progressively" with Text revised as suggested. Work Plan" paragraph 4 "continuously" or delete. {definition of "Evaluation"), page 8. 9 1/23/2013 "Palo Verde SSC Project This phrase (i.e., "participating in working Text revised to read, "The PPRP will be involved Work Plan paragraph 4 meetings, as needed.") is not clear. I in the evaluation process through attending (definition of suggest that at least one PPRP member workshops, reviewing interim project "Evaluation}, page 8. attend each working meeting, with a documentation, and attending selected working responsibility to report back to the other meetings." PPRP members on the meeting. In all likelihood, the written summary of each working meeting prepared by the Tl Team would be sufficient documentation of the meeting for PPRP purposes. This activity should be represented in the budget for the PPRP. 10 1/23/2013 "Palo Verde SSC Project I think this {i.e., the phrase "if needed" in Text revised as suggested. Work Plan" paragraph 9 reference to review by regulatory {definition of officials) could be deleted-regulatory "Documentation"), page review is needed! 9. 11 1/23/2013 "Structure of A written summary should be produced Text revised to read, "A summary session will be Workshops" paragraph for the workshop; would the compilation provided at the conclusion of each day. The intent 1, page 10. of results of the daily summary sessions of the summary sessions is to identify action items constitute the written summary? Does and key findings from the workshop. These action this {i.e., "workshop presentations will be items and key findings will be summarized in documented") mean they will be included slides presented during each summary session. in the project files? All workshop materials and presentations will be included in the project file." 12 1/23/2013 "Kev Proiect Tasks" Instead of "Exploration of kev data," Text revised as suaaested to read, "Presentation April 17, 2015 PVNGS SSC Additional Documentation Attachment 1. Page 3 of 4 COMMENT-RESPONSE LOG PALO VERDE SSHAC LEVEL 3 PROJECT PLAN No. Date Location in Project PPRP Comment Summary of Revisions to Project Plan Received Plan paragraph 7 (under would it be clearer to say "Presentation and discussion of key data, data uncertainties, 'Task 4"). page 12. and discussion"? What is the and appropriate use and limitations of the data "exploration" aspect you were aiming to and their interpretations." emohasize? 13 1/23/2013 "Key Project Tasks" To me, full evaluation must involve Text revised as suggested to read. "SSC logic paragraph 12 (under discussion and clarification with the trees and Source Evaluation sheets will be "Task 7"). page 14. model developers. Do you mean that the provided to the PPRP prior to Workshop 3 so that material provided prior to Workshop 3 the PPRP will be able to fully review in detail the will enable the PPRP to fully evaluate the V3 SSC model before the workshop. model during the workshop, such that evaluative PPRP comments during the workshop and in the written PPRP report would be comprehensive? I agree that receiving the logic trees and source evaluation sheets at the workshop would limit the PPRP evaluation process. 16 1/23/2013 "Project Schedule" Should put in the project completion Text revised as suggested to read, "in order to paragraph 2. page 18. date. comply with the NRG-mandated 50.54(f) completion date of March 2015." April 17, 2015 PVNGS SSC Additional Documentation Attachment 1. Page 4 of 4 ATTACHMENT 2 Formal Correspondence Between the Technical Integrator (Tl) Team and the Participatory Peer Review Panel (PPRP) Senior Seismic Hazard Analysis Committee (SSHAC) Level 3 Seismic Source Characterization Palo Verde Nuclear Generating Station (PVNGS) This attachment provides the signed correspondence between the Tl Team and the PPRP regarding development of the SSHAC Level 3 seismic source characterization for the PVNGS. The table below identifies the subjects and dates for the signed correspondence. Subject Date PPRP letter no. 1: Comments on Project Kickoff Meeting ("Workshop O") April 24, 2013 PPRP letter no. 2: Field trip to PVNGS site and vicinity following Workshop #1 April 29, 2013 Tl Team response to comments from PPRP on Project Kickoff Meeting May 7, 2013 PPRP letter no. 3: Comments on Workshop #1 June 5, 2013 Tl Team response to comments from PPRP on Workshop #1 July 15, 2013 PPRP letter no. 4: Comments on Workshop #2 October 23, 2013 Tl Team response to comments from PPRP on Workshop #2 November 26, 2013 PPRP letter no. 5: Field review of geologic mapping March 26, 2014 Tl Team response to comments from PPRP on field review of geologic mapping March 26, 2014 PPRP letter no. 6: Comments on Workshop #3 May 9, 2014 Tl Team response to comments from PPRP on Workshop #3 May 14, 2014 PPRP closure letter February 26, 2015 April 17, 2015 PVNGS SSC Additional Documentation Attachment 2, Page 1 of 51 April 24. 2013 Dr. Ross D. Hartleb LCI Project Manager. Palo Verde NGS Seismic Ha7.ard Evaluation Project Lettis Consultants International. Inc. 27441 Tourney Road, Suite 220 Valencia. CA 91335 SURJECT: Seismic Source Characterization (SSC) Participatory Peer Review Panel Letter No. I: Palo Verde \luclcar Generating Station Seismic I lazard Evaluation Project Kickoff Meeting (Workshop 0)

Dear Dr. Hartleb:

As the designated SSC Participatory Peer Revicv,* Panel (PPRP) for the Palo Verde Nuclear Generating Station (PV:"JGS) Seismic Hazard Evaluation Project. we (Savage. \1achettc, and Rockwell) wish to express our appreciation for the opportunity to attend the Project Kickoff Meeting (Workshop 0) on January 2L2013. We also thank you for coordinating our travel arrangements and providing a hospitable setting for the meeting in your Walnut Creek office. The Kickoff Meeting was well organized and conducted in a professional manner; it represents a successful start to the Project. The agenda and the conduct or the \1ccting '>Vere thoughtful. thorough, and efficient. We were pleased that the sponsor (PVNGS) was \Vell represented and actively participated in the Meeting. It \.\as useful for the PPRP to become informed by the Project Sponsor about the characteristics of the PV"l\GS at the start of the meeting. The SS! IAC training early in the meeting established the rigor or the SSI IAC Level 3 process, and the subsequent presentations info1med us about the Project Plan (dated January 17, 2013) and the existing PYNGS SSH AC Level 2 seismic source characterization model. The discussion of data requirements led directly to the need to identify resource and proponent experts: we appreciate the planned involvement of the PPRP in identifying these experts. The follov .. *-ing comments arc numbered consecutively for reference in any subsequent communications. We do not include shon technical comments that were provided during the Meeting. Following the practice that was agreed upon during the Meeting. we have underlined comments to which we would appreciate written responses. 1. The PPRP was provided '>-vith the Project Plan (dated January 17. 2013) in advance of the Kickoff Meeting. Although there was no formal discussion during the meeting of our detailed comments on the Project Plan, \VC think that the Project Plan is aligned well v.*ith the SSHAC Level 3 methodology and is comprehensive in its scope. We provided Dr. Ross D Hartleb 2 Final 4/24/13 additional comments after the meeting by email on January 23. 2013. We received a revised version of the Project Plan dated February 19. 20 I 3. The comments we provided appear to have been addressed satisfactorily, and we think the Plan is clearer and thus more effective for its intended use. You indicated that future revisions of the Project Plan could be made as the need for revisions arises. 2. The relationships betv..*een the Lcttis Consultants International (LCI) team and the Project Sponsor (PVNGS) and with Westinghouse Electric Company (the overall Project Manager for the PVNGS Seismic Hazard Evaluation Project) appear to be open and effective. We noted. for example. the care with which the protocol for releasing reports was discussed and established. 3. We concur with the benefits of having a recent SSHAC Level 2 seismic source characterization for the PVNGS site. However, care will need to be taken to avoid the occurrence of anchoring (e.g .. cognitive bias). The Project Plan (p. 2) provides a procedure intended to address this subject using self-evaluations. but docs not clearly include independent perspectives that could identify a condition of bias. We would apprecjale your_informing us of how you plan to obtain independent views of a.ny P9SSible bias on the Team's part. 4. Jc was helpful for the PPRP to have participated via conference call with the Ground Motion Characterization (GMC) team members during the SSC meeting. There was the appearance of a gap in communications regarding G\1C-SSC interface items that came out in Norm Abrahamson' s discussion. l t is advantageous to have Thomas Rock we 11 of the SSC-PPRP also serving on the OMC-PPRP for the Project lo help assure good coordination .. Evt;:_n_s.9..:. appreciate Y9.!l!. i!)formipg µs of how you intend to nu1intain a.n effective interface between the G\lf C and SSC aspects of the PSHJ\. Please contact us if you wish further discussion of any of our observations and comments. Sincerely yours, Dr. William L. Savage (Chair) Mr. Michael t\. Machette Dr. Thomas K. Rockwell PPRP Letter# I: PVNGS SSC WSO April 29, 2013 Dr. Ross D. Hartleb LCI Project Manager, Palo Verde NGS Seismic Hazard Evaluation Project Lettis Consultants International, Inc. 27441 Tourney Road, Suite 220 Valencia, CA 91335

SUBJECT:

Seismic Source Characterization (SSC) Participatory Peer Review Panel Letter No. 2: PPRP Field Trip to the Palo Verde Nuclear Generating Station site and vicinity following Workshop l, April 11, 2013

Dear Dr. I lartleb:

With PVNGS employee Mr. Chris Wandall as our host, the PPRP visited the Palo Verde Nuclear Generating Station (PVNGS) area on the morning of April 11, 2013. We arrived about I 0:45 a.m. and left about 12: 15 p.m., so our visit was a brief 1.5 hours long. Mr Wandall had broughl along a copy of Arizona Geologic Map DGM-47 by Pearthree and others (2006), which is the Geologic Map of the Wintersburg 7 .5-minute Quadrangle, Maricopa County, Arizona. The PYNGS is located in the southwest corner of the quadrangle and minor parts of the adjoining three maps. Our first observation is thal the site is characlerized by low relief and surrounded on at least three sides by small hills comprised of basalt (middle Miocene, ca. 21 m.y.), which is the youngest and only bedrock unit exposed in the area. This basalt is mapped as largely undifferentiated, but locally is split inlo two units on the basis of plagioclase phenocryst conlent (5-10%1 in the upper unit and sparse in the lower unit). Interestingly, small knobs of basalt on the north margin of the PYNGS arc mapped as upper and lower basalt with an inferred (dotted) fault separating outcrops with apparent down-to-the-south motion of tens to a hundred (?) feet. The mapped fault was likely inferred from the outcrop pattern, was probably of small displacement (for a bedrock fault), and was not mapped in adjacent Quaternary deposits as old as unit Qi2 (probably late middle Pleistocene, >I 00'? ka). The entire PVNGS site is mapped as "disturbed ground" owing to the massive amount of excavating and regrading that occurred during construction of the facilities in the late 1970s and early 1980s. We drove onto the site but noticed no exposures of any great depth, so any surficial geologic information would have to be obtained from pre-1976 aerial photography and mapping done for the initial site characterization. We were more successful in a few road cuts to the west and south of the PYNGS entrance (west side, south of reactors and cooling towers). In one bedrock-cored road cut lhere are south to southwest dipping ( 45°?) basalts and sedimenlary interbeds. On the north side of this cut, the colluvial apron of basalt fragments is completely cemented by PPRP Lettcr#2: PVNGS SSC PPRP Site Visit on 4/11/13 Dr. Ross D. Hartleb 2 FINAL 4/29/ 13 calcium carbonate, indicating that the eroded north slope of the hill was very stable for a long time and graded to a lower level (calcrctcs project below the road grade). To the north of this road cut there arc shallow road cuts (ditches) in a Quaternary piedmont deposit that we suspect correlates with Pearthree and others' unit Qi2. Three mapped Qi (intennediate) units are late to middle Pleistocene. The map unit description says units Qi2 and Qi I have stage Ill to IV morphology calcic soils, but all of the Qi I units mapped in the quadrangle arc to the cast, trending parallel to the I lassayampa River. Older Quaternary to Tertiary alluvium (unit QTs) is locally exposed to the north in the quadrangle and this unit may comprise a basin-fill unit since it includes an extensive clay-rich unit (the Palo Verde clay) that is older than 2 Ma. This unit may exist beneath the site, burying eroded basalts that surface in the area. Generally speaking, there arc poor exposures and small rcllcf within the immediate area of the PVNGS. Better exposures for understanding the Quaternary surficial units arc to be found in the eastern half of the Wintersburg quadrangle, so any future field trip to the site should include stops to the east. On further review of the Wintcrsburg geologic map subsequent to the field trip, Mr. Machelle discovered an error in the description of the Quaternary unit Qi I as printed on the map. After consultation with Dr. Philip Pearthree, senior author of the map, Dr. Pcarthrcc corrected the map explanation and offered to have the Arizona Geological Survey reissue the revised map in the near future. This change, although seemingly minor, is important in that the Wintersburg map is the most detailed modern geologic map that includes the PVNGS site. The change in the map explanation is in Appendix I to this letter; the change is highlighted in yellow on page I 0 of the Appendix. We greatly appreciate the time that Mr. Wandall took to provide us with an efficient and comprehensive view of the site and adjacent property. This advance perspective of the site geology, general layout of the facilities, and adjoining land use is already benefiting our understanding of seismic hazard issues for the site. Please contact us if you wish further discussion of any of our observations and comments. Sincerely yours, Dr. William U. Savage (Chair) Mr. Michael N. Machcttc Dr. Thomas K. Rockwell PPRP Letter #2: PVNGS SSC PPRP Site Visit on 4/11/13 Dr. Ross D. Hartleb 3 FINAL 4/29/ 13 Appendix 1: Revised Map Explanation for the Geologic Map of the Wintersburg 7.5' Quadrangle, Maricopa County, Arizona Revised description of unit Qi1 -Middle Pleistocene alluvium is highlighted in yellow on PagelO. Geologic Map of the Wintersburg 7.5' Quadrangle, Maricopa County, Arizona by Philip A. Pearthree, Charles A. Ferguson, and Raymond C. Harris Arizona Geological Survey Digital Geologic Map 47 (DGM-47) January 2006 Scale l :24,000 ( l sheet) Arizona Geological Survey 416 W. Congress St., #100, Tucson, Arizona 85701 Research supported hy the U.S. Geological Survey, National Cooperative Geologic Mapping Program, under USGS award number #04IIQAG0072. The views and conclusions contained in this document are those (!(the authors and should not be i11te11Jreted as necessarily representing the C?/lkial policies, either expressed or implied, ofthe U.S. Government. The Wintersburg 7 Yi' quadrangle is located 40 to 50 miles (70-80 km) west of downtown Phoenix. The map area covers much of the piedmont between the Palo Verde Hills and the llassayampa River and a 7 mile ( 11 km) reach of the llassayampa River. The quadrangle includes a portion of the Palo Verde Nuclear Generating Station (PVNGS) and Interstate Highway l 0. It has experienced some suburban development associated wilh the PVNGS and is currently on the outer fringe of the grealer Phoenix metropolilan area, so more development is likely in the near future. The small bedrock hills in the southwestern quarter of the quadrangle were mapped by Charles Ferguson in the spring of 2005. Surficial deposits that cover most of the quadrangle were mapped by Philip Pearthree using color aerial pholos from 1979, high-resolution digital color orthophotos provided by the Flood Control District of Maricopa County, and topographic infonnation. Field checking was done in the spring, summer and fall of 2005. This mapping was done in conjunction with geologic mapping of the Flatiron Mountain 7 W quadrangle (Spencer el al, 2005) to the north, and this quadrangle map is one of eight 1 :24,000 scale geologic maps covering most of the llassayampa Valley that have been produced in 2004 -2006. PPRP Letter #2: PVNGS SSC PPRP Site Visit on 4/11/13 Dr. Ross D. Hartleb 4 FINAL 4/29/ 13 This mapping was completed under the joint State-Federal ST ATEMAP program, as specified in the National Geologic Mapping Act of 1992. Surficial Geology The Wintcrsburg quadrangle is almost entirely covered with surficial deposits laid down by the Hassayampa River or numerous smaller tributary stream systems. These surficial deposits were mapped primarily using stereo pairs of color aerial photos taken in 1979 for the Bureau of Land Management, high-resolution digital orthophotos provided by the FDCMC, and topographic infonnation obtained from the 7 U.S. Geological Survey quadrangle map. Mapping interpretations were verified by field observations during the spring, summer and fall of 2005; unit characteristics were described and unit boundaries were spot-checked in the field. The physical characteristics of Quaternary alluvial surfaces (channels, alluvial fans, floodplains, stream terraces) evident on aerial photographs and in the field were used to differentiate their associated deposits by age and source. This mapping was compiled over a digital orthophoto base from 2003 provided by the Flood Control District of Maricopa County. Mapping was done in a GIS format and the final lincwork was generated from the digital data. Several characteristics evident on aerial photographs and on the ground were used to differentiate various alluvial surfaces and deposits associated with them by age and source. The color of alluvial surfaces is primarily controlled by soil color, desert pavement development and rock varnish, and vegetation type and density. Significant soil development begins beneath an alluvial surface afier it becomes isolated from active flooding and deposition (Gile ct al., 1981, Birkeland, 1999). I Iolocenc soils typically have relatively subtle horizons and generally arc brown or gray in the field and on aerial photographs. More distinct, relatively obvious soil horizons develop over thousands to tens of thousands of years. Typical soil horizons in Pleistocene alluvial sediments of Arizona arc reddish brown argillic horizons (zones of clay accumulation) and white calcic horizons (zones of calcium carbonate and silica accumulation). In arid areas such as the lower Hassayampa Valley, day accumulation and reddening associated with argillic horizon development tend to be relatively weak even on old alluvial surfaces. On color aerial photographs and on the ground, older alluvial surfaces characteristically appear slightly redder or distinctly whiter (on more eroded surfaces) than younger surfaces. Dark rock varnish and gravel pavements also develop with time on stable alluvial surfaces, so well-preserved older surfaces typically have a dark brown color. Differences in the drainage patterns between surfaces also provide clues to surface age. Young alluvial surfaces commonly display distributary (branching downstream) or anastomosing (branching and rejoining) channel patterns. Areas adjacent to active channels commonly have little channel development because unconfined shallow flooding predominates. Dcndritic tributary (joining downstream) drainage patterns arc characteristic where modem drainages arc incised into older surfaces. Topographic relief between adjacent alluvial surfaces and the depth of entrenchment of channels can be detennined using stereo-paired aerial photographs and topographic maps. Young surfaces arc minimally dissected and arc less than I m above channel bottoms. Active channels PPRP Letter #2: PVNGS SSC PPRP Site Visit on 4/11/13 Dr. Ross D. Hartleb 5 FINAL 4/29/ 13 are entrenched 1 to 5 m below Pleistocene alluvial surfaces, and the older surfaces typically have been moderately to severely rounded by erosion. Ages of various surficial deposits of the map area were roughly estimated based on regional correlations to similar surficial deposits in southern Arizona. Variations in the distribution of surfaces of different ages and sources and concomitant variations in dissection across the quadrangle provide evidence regarding the recent geologic evolution of this area. Generally, areas along the Hassayampa River are moderately to deeply dissected. The highest terrace remnants of the Hassayampa River (unit Qi,r) record the level of the river bed in the early to middle Quaternary. Qi1r terraces cap a several hundred meter thick aggradational sequence that was deposited during late Tertiary to early Quaternary (units QTs and QTsr) (Shoustra et al., 1976). Adjacent piedmont areas to the west and north were aggrading in the late Pliocene and early Quaternary as well (unit QTs). At that time the river was probably was depositing sediment across a fairly broad floodplain in the eastern part of the quadrangle, and distal alluvial fans on both sides of the river were interfingering with the river floodplain. Since then the Hassayampa River has downcut 10 to 15 m, with incision increasing slightly to the north. Preservation of Pleistocene river terraces recording intermediate levels of the I lassayampa River is poor. The valley bottom along the I lassayampa River consists almost entirely of modem channel deposits (unit Oyer) and late Holocene floodplain deposits (Qy2r). Tributary washes immediately west and east of the Hassayampa River have downcut in response to incision of the river, and late Quaternary deposits arc quite limited in extent along these drainages. In the western 2/3 of the quadrangle, piedmont washes drain to the south to the Gila River or Centennial Wash, a sizable tributary of the Gila River. Much of this piedmont is mantled by Pleistocene tributary deposits (units Qi1, Qii, or Qi.;). Older Pleistocene deposits (Qi1 and Qh) have been eroded into broadly rounded or moderately rounded ridges, respectively. The relatively small tributary washes that drain this area are incised less than a few meters below adjacent Pleistocene alluvial surfaces. Even though the amount of net incision is modest, there is enough topographic confinement of active fluvial systems that late Pleistocene deposits typically are found on the fringes of the eroded middle Pleistocene ridges, and Holocene deposits are found on valley bottoms. Agricultural activity, more recent residential development, aggregate pits and the PVNGS have modified the landscape to greater or lesser degrees. Areas arc mapped as "disturbed" where the surficial deposits are profoundly altered (gravel pits, nuclear plant, interstate surficial deposits other areas with less profound disturbance are depicted with concealed (dotted) contacts. Geologic Hazards and Aggregate Resources The geomorphology and surficial geology of the quadrangle provide clues to the extent and character of flood hazards and the availability of aggregate resources. Geologically young fluvial deposits (units Qye, Qy2, and locally Qy1 along tributary washes and units Oyer, Qy2r along the Hassayampa River) record recent fluvial activity. The Hassayampa River is incised and flooding is restricted to the valley bottom. The fact that the valley PPRP Letter #2: PYNGS SSC PPRP Site Visit on 4/11/13 Dr. Ross D. Hartleb 6 FINAL 4/29/ 13 bottom is covered almost entirely by late Holocene deposits strongly suggests that the valley bottom is the floodplain, and all portions of it have been subjected to recent inundation and deposition. Flooding is restricted to relatively narrow corridors along the incised tributary washes that drain directly to the Hassayampa. Flood-prone areas are somewhat more extensive in the western 2/3 of the quadrangle where incision is modest. Valley bottoms covered with young deposits but channels arc quite small, implying that shallow sheet flooding and bank erosion along channels arc the principal flood hazards. Although valley bottoms are fairly wide, there are no major distributary channel networks or active alluvial fans on the piedmont. Aggregate resources were extracted from several small pits in piedmont surficial deposits near Interstate Highway l 0, probably for construction of the highway. Two larger aggregate operations are currently active along the Hassayampa River north ofl-10. These operations arc apparently mining aggregate primarily from I loloccne river deposits, but they may be drawing upon older river deposits as well. The potential for useful aggregate resources in older river deposits that flank the modem floodplain is not known because the thickness of these deposits is uncertain. Both earth fissures (I larris, 200 I) and giant desiccation cracks (I Iarris, 2003) have been recognized in the southwestern portion of the quadrangle. A new earth fissure opened in the summer of 2000 about 3 miles (5 km) southeast of Wintersburg. The fissure trends nearly north-south and is about I, I 50 ft (350 m) long. The fissure is very young, with narrow, steep sides and a highly irregular apparent depth ranging from <l foot to >8 feet over short distances. In two locations the fissure is en echelon, with NW-SE steps. There is no discemable vertical offset across the fissure. The location of the fissure, at the edge of the Palo Verde basin and somewhat in line with the trend of a small hill, suggests that a shallow buried bedrock ridge may extend south of the hill beneath the trace of the fissure. If this scenario is correct, the crack may represent fissuring due to compaction and subsidence on either or both sides of the buried ridge. Adjacent lo the new earth fissure is an area of giant desiccation cracks that opened at the same time as the earth fissure. Alignments of established vegetation in some portions of the polygonal desiccation crack network demonstrate that cracking has occurred periodically in the past. Additional areas of giant desiccation cracks were mapped by Harris (2003) immediately west and south of the Wintcrsburg quadrangle. Bedrock Geology Basalt lava flows cap several hills in the southwest comer of the map area. The basalt is part of an extensive lava field known as the Palo Verde I I ills lava field. The flows were sampled extensively in and around the PVNGS prior to its construction. The lavas range in age from 16.9 to 20.7 Ma (Shoustra el al., 1976; Shafiqullah et al., 1980). In general, the lavas arc gently dipping, but locally, dips of up to 70 degrees have been reported for lavas to the west of this map area (Shafiqullah ct al., 1980). The westernmost hills, which lie directly north of the PVNGS, are divided into two map units. A gently northeast-dipping contact between the units, concealed by colluvium, is PPRP Letter #2: PVNGS SSC PPRP Site Visit on 4/11/13 Dr. Ross D. Hartleb 7 FINAL 4/29/ 13 interpreted to be present on the westernmost hill. The upper lava contains abundant mafic (pyroxene and/or olivine), and plagioclasc phcnocrysts (Tbu). The lower lava contains only mafic phcnocrysts (Tbl). Similar units arc found in the low hills just to the cast. Two interpretations are possible for the vokanic stratigraphy and structure of this area. The simplest interpretation, which is depicted on the map, shows the sequence of upper and lower lavas repeated by a southwest-side-down nonnal fault with modest (50-100 m) displacement. An alternative interpretation is that there is no fault, but that the volcanic stratigraphy is more complex, with intertonguing flows of different composition. The pair of hills lying to the cast of the PVNGS arc composed of amalgamated flows of ma fie phcnocryst-porphyritic basaltic lava (Tb) that appear to dip moderately to the southwest. These lavas were interpreted by Shafiqullah et al. ( l 980) to represent the oldest in the area. This sequence may correlate with the Tbl map unit, but since there are no other types of lava in the area, and since the flows dip in the opposite direction these rocks arc mapped as undifferentiated basalt lava (Tb). The difference in dip between the eastern and western hills implies that an intervening structure may exist. Acknowledgments. The Flood Control District of Maricopa County provided resolution digital orthophotos that were used to accurately locate surficial geologic unit boundaries. References Birkeland, Peter W., 1999, Soils and Geomorphology (3rd Ed.), New York: Oxford University Press, 429 pp. Gile, L.H., Hawley, J.W., and Grossman, R.B., 1981, Soils and geomorphology in the basin and range area of southern New Mexico --guidebook ot the Desert Project: New Mexico Bureau of Mines and Mineral Resources Memoir 39, 222 pp. Harris, R.C., 2001, A new earth fissure near Wintersburg, Maricopa County, Arizona: /\ZGS OFR Ol-10, 23 p. I larris, R.C., 2003, Additional giant desiccation cracks near Wintcrsburg, Maricopa County, Arizona: AZGS OFR 03-07, l 7 p. Machcttc, M.N., 1985, Calcic soils of the southwestern United States: in Weide, D.L., ed., Soils and Quaternary Geology of the Southwestern United States: Geological Society of America Special Paper 203, p. 1-2 l. Shafiqullah, M., Damon, P. E., Lynch, D. J., Reynolds, S. J., Rehrig, W. A., and Raymond, R. 11., 1980, K-Ar geochronology and geologic history of southwestern Arizona and adjacent areas, in Jenney, J.P., Stone, C., (eds.), Studies in western Arizona: Arizona Geological Society Digest 12, p. 201-242. PPRP Letter #2: PVNGS SSC PPRP Site Visit on 4/11/13 Dr. Ross D. Hartleb 8 FINAL 4/29/ 13 Shoustra, J. J., Smith, J. L., Scott, J. D., Strand, R. L., and D., 1976, Geology and scismicity, site lithologic conditions and Appendix 2Q (Radiometric age), in Palco Verde Nuclear Generating Stations I, 2, and 3, Preliminary safety analysis report: Arizona Public Service Commission, v. 2, Section 2.5; v. 8, Appendix 2Q. Spencer, J.E., Youberg, Ann, and Ferguson, C.A., 2005, Geologic map of the Flatiron Mountain 7 Yi' Quadrangle, Maricopa County, Arizona: Arizona Geological Survey Digital Geologic Map DGM-46, scale l :24,000. Surficial Map Units Piedmont Alluvium Quaternary and late Tertiary piedmont deposits from the Belmont Mountains to the north cover the western 2/3 of the Wintersburg quadrangle. This alluvium was deposited primarily by larger tributary streams that head to the north of the quadrangle; these larger streams and smaller streams that in this quadrangle have eroded and reworked some of these deposits. Clast lithologies include basalt and fclsic volcanic rocks with lesser amounts of granite. Deposits range in age from modem to Pliocene. Abbreviations used are ka, thousands of years before present, and Ma, millions of years before present. Qyc -Modern stream channel deposits. Active channel deposits composed of very poorly-sorted sand, pebbles, and cobbles with some boulders to moderately-sorted sand and pebbles. Channels are generally incised 0.5 to 2 m below adjacent I lolocenc terraces and alluvial fans, but may be incised as much as 4 m below adjacent Pleistocene deposits. Channel morphologies generally consist of a single thread, relatively deep channel or multi-threaded smaller, shallower channels with gravel bars. Channels are extremely flood prone and are subject lo deep, high velocity flow in moderate to large flow events. Areas adjacent to Qyc deposits may be prone to lateral bank erosion. Qn -Late Holocene alluvium. Young, typically fine-grained deposits in floodplains, low terraces and small channels. Along the larger drainages, unit Qy2 sediment is generally poorly to very poorly sorted silt, sand, pebbles, and small cobbles; floodplain and terrace surfaces typically are mantled with sand and finer sediment. On lower piedmont areas and in smaller tributary washes young deposits consist predominantly of moderately sorted sand and silt, with some pebbles and cobbles in channels. Soils arc pale brown in color (I 0 YR), and soil development is very weak, consisting of slight carbonate accumulation. Channels generally are incised less than l m below adjacent young surfaces, but locally incision may be as much as 2 m. Channel morphologies generally consist of a single-or multi-threaded channels with gravel bars adjacent to low flow channels. Channels arc flood prone and may be subject to deep, high velocity flows in large flow events. Substantial lateral bank erosion may occur in these deposits, and flood flows may significantly change channel morphology and flow paths. Local relief varies from fairly smooth channel PPRP Letter #2: PVNGS SSC PPRP Site Visit on 4/11/13 Dr. Ross D. Hartleb 9 FINAL 4/29/ 13 bottoms to undulating bar-and-swale topography that is characteristic of coarser deposits. Terraces have planar surfaces, but small channels arc common. Qy1 -Holocene alluvium. Older Holocene terrace deposits found mostly along the margins of incised drainages throughout the map area. Qy1 surfaces are higher and less subject to inundation than adjacent Qy2 surfaces. Qy1 terraces arc generally planar but local surface relief may be up to I m where gravel bars arc present. Qy1 surfaces are < 2 m above adjacent active channels. Surfaces typically are sandy but locally have unvarnished open fine gravel lags or pebble and cobble deposits. Qy1 soils typically arc brown in color (7.5 to 10 YR) with weakly developed stage I calcium carbonate accumulation (sec Machcttc, 1985, for description of stages of calcium carbonate accumulation in soils). Qyf -Fine-grained Holocene alluvium. Thin, fine-grain I loloccnc alluvial deposits fonncd in swales on ridges of mid-Pleistocene fan deposits. These deposits arc very thin, typically less than 0.5 m thick, but locally may be 1 m or more thick. Sediment typically is brown (7 .5YR) mainly silt and sand, with occasional deposits of open, unvarnished, fine gravel lag. Soil development is minimal, with substantial disseminated carbonate but little visible carbonate accumulation. Qy Holocene alluvial deposits, undifferentiated. Qh -Late Pleistocene alluvium. Unit Qi.; is composed of slightly dissected relict alluvial fans and terraces. Active channels are incised up to about 2 m below QiJ surfaces, and Qb fans and terraces generally are lower in elevation than adjacent older surfaces. Qi.; deposits consist of pebbles, cobbles, and finer-grained sediment. Qi.; surfaces commonly arc fairly smooth with weak bar and swale topography and loose to moderately packed pebble and cobble pavements. Surface gravel clasts typically exhibit weak to moderate brown rock varnish but some surfaces in the northern part of the quadrangle that arc mainly composed of fine-grained volcanics arc more darkly varnished. Qi.; soils arc moderately developed, with brown loamy (7 .5 YR) near-surface horizons and stage II calcium carbonate accumulation. Qh -Middle to late Pleistocene alluvium. Unit Qi2 is composed of moderately dissected relict alluvial fans and terraces with moderate soil development. Qi:! surfaces are drained by broad swales and well-developed, moderately incised tributary channel networks; channels are typically 1-2 meters below adjacent Qh surfaces. Well-preserved, planar Qi2 surfaces arc smooth with pebble and cobble pavements; surface color is reddish brown; surface gravel clasts arc moderately to strongly varnished. More eroded, rounded Qi2 surfaces are characterized by strongly varnished, scattered, cobble to pebble lags. Soils associated with planar surface remnants typically contain reddened (5 to 7.5 YR), clay loam argillic horizons, with clay coatings and subangular blocky structure. Underlying soil carbonate development is typically stage III with areas to stage IV, and abundant carbonate through at least 1 m of the soil profile. In more eroded locations, argillic horizons have been removed and soils arc calcic throughout. PPRP Letter #2: PVNGS SSC PPRP Site Visit on 4/11/13 Dr. Ross D. Hartleb lO FINAL 4/29/ 13 Qi1 -Middle Pleistocene alluvium. Unit Qi 1 is composed of deeply dissected relict al1uvial fans. Qi I surfaces form rounded ridges that arc higher than adjacent Qi2 surfaces. Drainage networks include broad swales on the ridge tops and tributary channels incised 3 to 4 m. Underlying eroded QTs deposits are occasionally exposed along some ridge slopes and wash banks. Wcl1-prcscrvcd Qi I surfaces arc limited in extent, but have moderately to tightly packed cobble, boulder, and pebble lag. Surface clasts are strongly to very strongly varnished and commonly have carbonate rinds up to 2 mm thick. More eroded, rounded Qi 1 surfaces are characterized by variably varnished, scattered, cobble and boulder lags with locally exposed laminar carbonate horizons. Where well preserved, Qi 1 soils arc strongly developed with a dark red (5-2.5 YR), heavy clay argillic horizon and subangular blocky to prismatic structure, with underlying petrocalcic stage IV to V. More eroded surfaces have common carbonate fragments and accumulations on gravel clasts arc 1-2 mm thick. This unit approximately correlates to unit M 1 a of Field and Pcarthrcc ( 1991 ). Qi -Middle and late Pleistocene alluvial deposits, undifferentiated. QTs -Early Pleistocene to Pliocene alluvium. Unit QTs is composed of eroded al1uvial fan deposits, locally overlain by younger Quatemary units. QTs deposits typically are poorly exposed on ridge slopes, in wash banks, and in channels as strath terraces. The thickness of QTs deposits is variable, but certainly is at least tens of meters (Shoustra ct al., 1976). In the shal1ow subsurface, unit QTs includes an extensive day-rich unit (the Palo Verde day) that is older than 2 Ma (Shoustra et al., 1976). Surface exposures of QTs include poorly sorted, subangular to subrounded, carbonate cemented, tan, pebble to cobble conglomerates, moderately to well sorted, subangular to subroundcd, moderately induratcd, cross-bedded, red, pebbly sandstones, and buried paleosols. Hassayampa River Alluvium Quaternary and late Tertiary piedmont deposits associated with the I lassayampa cover the eastern margin of the Wintersburg quadrangle. Clast lithologies are quite diverse, but are principally mixed fine-grained volcanic rocks and granite. Clasts range from roundcd to subangular in shape. Deposits range in age from modern to Pliocene. Qycr -Active river channel deposits. Moderately lo poorly sorted sand, gravel and minor silt in recently active channels and lightly vegetated bars of the Hassayampa River. Gravel consists mainly of pebbles with some cobbles; clasts range from subangular to well-rounded. Qy2r -Late Holocene floodplain deposits. Sand, silt, and gravel deposits associated with the floodplain and low terraces along the I lassayampa River. Qy2r surfaces typically arc smooth and arc less than 2 m above the active channel. T crracc surfaces PPRP Letter #2: PVNGS SSC PPRP Site Visit on 4/11/13 Dr. Ross D. Hartleb l l FINAL 4/29/ 13 typically are covered with fine-grained floodplain deposits, but relict gravel bars and lenses arc common. Qy1r -Older Holocene river terrace deposits. Sand, silt, and gravel deposits associated with slightly higher terraces along the Hassayampa River. Terrace surfaces typically arc flat but rounded around their margins and arc less than 3 m above the active channel. Terrace surfaces typically arc covered with a fine gravel lag where preserved but are quite fine-grained where eroded. Qhr -Late Pleistocene river terrace deposits. Deposits associated with low intcnncdiatc terraces inset about 3 m above the I loloccnc floodplain of the Hassayampa River. Deposits consist of sand, silt, and gravel, with weak lo moderate soil carbonate (Stage 1-11) accumulation. Terrace surfaces typically are smooth and arc covered with fine-grained floodplain deposits, but relict gravel bars and lenses arc found locally. Qhr-Middle Pleistocene river terrace deposits. High intennediale terraces about 5 m above the Holocene floodplain of the llassayampa River. Terrace surfaces typically arc dissected by small tributary drainages but arc smooth away from the drainages. Terrace deposits are a mix of river sand, gravel, and silt and clay, but surfaces typically are covered with relict gravel deposits. Soil development is moderately strong, consisting primarily of stage JI to Ill caleic horizons. Qiir -Early to middle Pleistocene river deposits. Deposits associated with the highest terraces along the Hassayampa River that record the maximum aggradation of the river. Terrace surfaces arc broadly rounded, and the deposits arc moderately to deeply dissected by tributary drainages and the river and have been substantia11y modified by erosion. Exposures are poor, but subangular to well-rounded gravel is evident al the surface. Terrace surfaces are also typically covered with litter from underlying induratcd stage IV pctrocalcic soil horizons. Qi1r terrace surfaces arc more extensive than any of the younger Pleistocene terraces. T crrace surfaces range from about l 0 to 15 m above the active river channel, and rise slightly to the north across the quadrangle. QTsr -Pliocene to early Pleistocene river deposits. A sequence of old river deposits of unknown thickness that underlies the Qi1r terrace deposits. These deposits consist of river sand, gravel and sill with a substantial component of tributary sand and gravel. Local zones of substantial carbonate accumulation may represent moderately to strongly developed buried soils. Other Units Qtc -Quaternary hillslope talus and colluvium. Thin, steeply to moderately sloping, weakly bedded hillslope deposits mantling the middle and lower slopes of basalt hills. Deposits are locally derived and very poorly sorted, consisting of angular to subangular basalt cobbles and boulders with a matrix of sand, silt and clay. Older PPRP Letter #2: PVNGS SSC PPRP Site Visit on 4/11/13 Dr. Ross D. Hartleb 12 FINAL 4/29/ 13 hillslope deposits have darkly varnished cobble and boulder mantles and relatively clay-rich soils. d -Disturbed areas. Much of the quadrangle has been disturbed by human activities, particularly agricultural activities. This unit designation is used only in areas of substantial excavation or anthropogenic deposition, for example, major flood-control levees. Bedrock Units Thu -upper basalt. Basalt lava containing 3-7% -2mm ma fie phcnocrysts (pyroxene and/or iddingsite altered olivine), and 5-10% l-4mm plagioclase phenocrysts (samples: CAF-2-10637, 10638, 10639, 10643, 10649, 10650, 11343, 11344, 11345, 11346,and 11348) Thi -lower basalt. Basalt lava containing 3-7%, l-3mm mafic phenocrysts (pyroxene and/or iddingsite altered olivine), and sparse l-2mm plagioclase phenocrysts (samples: CAF-2-10640, 10644, 10646, 10648) Tb -basalt lava, undifferentiated. Basalt lava containing 2-7%, 0.5-3mm mafic phenocrysts (pyroxene and/or iddingsite altered olivine) with sparse plagiodase phcnocrysts <2mm (samples: CAF-2-10622, I 0626, I 0631, and I 0635). Shafiqullah ct al. ( 1980) report a whole rock, Kl Ar age of 20. 7 + 0.6 Ma for this unit, making it the oldest known lava from the Palo Verde lava field. PPRP Letter #2: PVNGS SSC PPRP Site Visit on 4/11/13 To: From:

Subject:

Dear Sirs,

William Savage (Participatory Peer Review Panel (PPRP) chair) Michael Machette (PPRP member) Thomas Rockwell (PPRP member) William Lett is (Project Technical Integrator (PTI)) May 7, 2013 Scott Lindvall (Seismic Source Characterization (SSC) Technical Integrator (Tl) Team Lead) Ross Hartleb (Lettis Consultants International (LCI) Project Manager) Response to comments from the PPRP on Workshop #0 (Project Kickoff Meeting) Palo Verde Nuclear Generating Station (PVNGS) Seismic Hazard Evaluation Project Senior Seismic Hazard Analysis Committee (SSHAC) Level 3 SSC This letter constitutes our response to comments from the PPRP's Letter No. 1 dated April 24, 2013 on the PVNGS SSC Workshop #0 ("Project Kickoff'), which was held on January 21, 2013. We appreciate the PPRP's thoughtful review of both the SSHAC process and the technical issues presented at Workshop #0. The PPRP's Letter No. 1 includes four specific comments on Workshop #0. Two of these comments (comments 3 and 4) contain underlined passages. As requested by the PPRP, we provide in this letter our specific responses to each of the PPRP's underlined comments. For ease of reference, our responses below are numbered in a manner consistent with the numbering of comments in PPRP Letter No. 1. Specific Comments PPRP Comment #3: We concur with the benefits of having a recent SSHAC Level 2 seismic source characterization for the PVNGS site. However, care will need to be taken to avoid the occurrence of anchoring (e.g., cognitive bias). The Project Plan (p. 2) provides a procedure intended to address this subject using self-evaluations, but does not clearly include independent perspectives that could identify a condition of bias. We would appreciate your informing us of how you plan to obtain independent views of any possible bias on the Team's part. Response to PPRP Comment #3: A SSHAC Level 2 SSC for the PVNGS was completed in 2012. The Tl team for that SSHAC Level 2 SSC included Scott Lindvall and Kevin Clahan. Gabriel Toro served as a hazard analyst for the SSHAC Level 2 probabilistic seismic hazard analysis (PSHA). The Tl team for the ongoing SSHAC Level 3 SSC comprises Scott Lindvall, Kevin Clahan, Gabriel Toro, and Ross Hartleb. Because of the partial overlap in personnel between the SSHAC Level 2 and SSHAC Level 3 Tl teams, the PPRP is correct in pointing out the potential for cognitive bias (or "anchoring") to the existing SSHAC Level 2 SSC model. The following steps have been taken to ensure independent views of any possible bias on the Tl team's part and to minimize cognitive bias: Page 1of3 Response to comments from the PPRP on Workshop #0 (Project Kickoff Meeting) -May 7, 2013

• The SSHAC Level 3 Tl team includes members who did not participate in development of the SSHAC Level 2 SSC. Specifically, PTI William Lettis and Tl team member Ross Hartleb did not participate in development of the SSHAC Level 2 SSC and thus bring fresh perspectives to the ongoing SSHAC Level 3 SSC effort. Gabriel Toro acted as a hazard analyst for the SSHAC Level 2 PSHA, but he did not participate in the development of the SSHAC Level 2 SSC. As such, Gabriel Toro also brings his fresh perspective to the SHAC Level 3 SSC Tl team.
• Discussions of cognitive bias will be included at the start of each workshop and working meeting by the PTI or Tl Lead. Moreover, if apparent cognitive bias arises at any point during a workshop or working meeting, the Tl Lead or other Tl team members or staff will be responsible for alerting the Tl team.
• Continual review of SSC development will be performed by the PPRP for the duration of the project. The Tl team expects that the PPRP will alert the Tl team of any perceived cognitive bias at any point during the project. PPRP Comment #4: It was helpful for the PPRP to have participated via conference call with the Ground Motion Characterization (GMC) team members during the SSC meeting. There was the appearance of a gap in communications regarding GMC-SSC interface items that came out in Norm Abrahamson 's discussion. It is advantageous to have Thomas Rockwell of the SSC-PP RP also serving on the GMC-PPRP for the Project to help assure good coordination. Even so, we would appreciate your informing us of how you intend to maintain an effective interface between the GMC and SSC aspects of the PSHA. Response to PPRP Comment #4: The PPRP is correct in noting the importance of, and need for, ongoing technical and logistical communication between the PVNGS SSC Tl team and the Southwestern United States Ground Motion Characterization (SWUS GMC) project. An effective interface between the SSC and GMC efforts will be maintained by the following:
• In addition to his role as PPRP member for the PVNGS SSC project, Thomas Rockwell also serves as a member of the PPRP for the SWUS GMC project. As such, he will be able to provide information and coordination between the SSC and GMC projects.
• The Project Plan defines the role of the PTI as a technical expert responsible for ensuring coordination and compatibility between the SSC and GMC Projects. William Lettis is the PTI for the PVNGS SSC project and, therefore, is responsible for maintaining effective communication between the SSC and GMC projects.
• Members of the PVNGS SSC project also serve as members of the SWUS GMC project. Specifically, PVNGS SSC hazard analyst Robin McGuire is the Palo Verde PTI for the SWUS GMC project. Thus, he will attend all PVNGS SSC and SWUS GMC workshops, be informed of SWUS GMC Tl team deliberations, and provide an important interface between the PVNGS SSC and SWUS GMC projects. Likewise, PVNGS SSC hazard analyst Melanie Walling serves as the Palo Verde hazard analyst for the SWUS GMC project. In this role, she attends all SWUS GMC workshops and working meetings. Thus, Melanie Walling will be able to provide to the PVNGS SSC Tl team her first-hand knowledge of discussions and activities of the SWUS GMC project, and vice versa.
• PTI William Lettis and Tl Team Lead Scott Lindvall attended and presented at SWUS GMC Workshop #1, which was held on March 19-21, 2013. This workshop also was attended by PVNGS SSC hazard analysts Robin McGuire and Melanie Walling.
• Hazard analyst Melanie Walling and Tl team member and Project Manager Ross Hartleb participate in weekly status conference calls for the Palo Verde Seismic Hazard Evaluation Project. These conference calls also include participants from Arizona Public Service (APS) and Page 2 of 3 Response to comments from the PPRP on Workshop #0 (Project Kickoff Meeting) -May 7, 2013 Westinghouse Electric Company. The purpose of these calls is to discuss project progress, schedule, and SSC-GMC interfaces. Closure We appreciate the comments from the PPRP on Workshop #0 and suggestions for improvement to the ongoing Palo Verde Seismic Hazard Evaluation Project. We are incorporating your observations, suggestions, and recommendations into our program to the extent possible. We look forward to seeing you again at Workshop #2 and to sharing with you our additional progress on the project at that time. Sincerely, (v,_fi__ kf1lu William Lettis PTI ,... .... . I I \ \..(-> 1 "1.:: I * \ , .. * * " , \ Ross Hartleb LCI Project Manager Scott Lindvall SSC Tl Team Lead Page 3 of 3 June 5, 2013 Dr. Ross D. Hartleb LCI Project Manager, Palo Verde NGS Seismic Hazard Evaluation Project Lettis Consultants International, Inc. 27441 Tourney Road, Suile 220 Valencia, CA 91335

SUBJECT:

Seismic Source Characterization Participatory Peer Review Panel Letter No. 3: Palo Verde Nuclear Generating Station Seismic Hazard Evaluation Project, Workshop No. I: Significant Issues and Data Needs

Dear Dr. Hartleb:

This letter provides the report of the Seismic Source Characterization (SSC) Participatory Peer Review Panel (PPRP) on the Palo Verde Nuclear Generating Station (PYNGS) Seismic Hazard Evaluation Project Workshop No. 1 (WS 1). The workshop was held on April 9-10, 2013, in Litchfield Park, AZ at the conference facilities of the Wigwam Resort. WS 1 is identified as Task 4 in the current version of the SSC Project Plan, dated February 19, 2013, and is also discussed in Section 4.6. l of NUREG-2117. In accord with these guidance documents, the PPRP attended WS I as observers during the daily proceedings of the two-day workshop to become informed by the presentations and discussions, and to review both lhe technical and procedural aspecls of the workshop. All three members of the PPRP (M. Machette, T. Rockwell, and W. Savage) attended WS 1 and observed all aspects of the workshop. The PPRP met at the end of each day with the TI lead, Tl Team members, and Sponsor representatives to provide verbal comments that could be used during the course of the ongoing workshop and in preparing this letter. The PPRP appreciated the preparations for and conduct of the workshop in terms of the hospitality and professionalism of the Sponsors and the Project Team and their staff. The well-planned and efficiently followed agenda for the technical presentations and discussions led to successfully illuminating both available resources and deficiencies. The comfortable facilities and staff of the Wigwam Resort also contributed to the effectiveness of the workshop. The PPRP' s general observations and as well as specific comments and recommendations arc provided in the remainder of this letter. Those parts of the comments that require a written response are underlined for clarity. PPRP Letter #3: PVNGS SSC WS l Dr. Ross D. Hartlcb 2 FINAL 6/5/13 General Observations Regarding the Workshop Process As described in NUREG-2117 and the SSC Project Plan, the scope and pmvose of WS I is narrowly defined with specific goals and purposes to identify hazard-significant technical issues, and to identify the available data and information need to address the issues. The detailed agenda for WS I laid out the goals and approach for the workshop in a fashion that is fully consistent with the above governing documents for a SSHAC Level 3 study. The PPRP appreciated being contacted with regard to finalizing a list of prospective Resource Experts to be invited to WS l. The initial list was thoughtfully developed and the individual members of the PPRP made additional suggestions and comments as they felt were appropriate. At the start of the Workshop, the PPRP particularly noted the articulate, thorough and energizing summary of the SSHAC methodology, project organization, guidance to the Resource Experts, and intra-project coordination as presented by William Lettis. For the purpose of improving the collegiality and communication during the Workshop, it would have been helpful to have been provided brief bios (name and titles, organization. technical area of interest, role in the project) for each of the meeting participants so that each participant could more quickly establish an intellectual and conversational relationship with his or her peers. It would also be helpful for future meetings to provide name tents for the table for each individual. Name tags should have the preferred nickname of the individual and project role or home organization. The interactions between the Project TI Team members, technical support staff and the invited Resource Experts (REs) were engaging and productive. The prepared questions that were given to each RE in advance of the workshop served to help elicit information and perspectives that were directly relevant to the project. The PPRP observed that all the TI Team members contributed by asking questions and sustaining discussions with the REs. As appropriate, members of the support staff were also directly involved in the discussions. This high level of active participation on the part of the Project personnel is viewed by the PPRP as an important indication of a healthy intellectual interaction within the Project Team. The presentation of the previously developed SSHAC-Levcl-2 "Base Case" SSC model was effectively used to establish a knowledge base upon which the REs contributions could be considered. The sensitivity analyses presented by Melanie Walling were particularly useful during the course of the workshop. For future meetings, it would be useful to check the brightness of the room and the positioning of the projector(s) with respect to the screen(s) to assure that people in the back of the room can see the most detailed slides with reasonable clarity. The PPRP noted that several presenters commented that they had difficulty seeing their own PPRP Letter #3: PVNGS SSC WS l Dr. Ross D. Hartleb 3 FINAL 6/5/13 projected images clearly. It is also the case that some presenters did not have we11-prepared slides regardless of the projection facilities! Specific comments on Significant Issues and Data Needs I. Status or seismicity data for use in the Project. There arc several important uses of seismicity data (the catalog of parameters of located earthquakes) in the SSHAC 3 study for the PVNGS site. including associating earthquakes with geologic structures or zones, and developing statistical models for seismicity within geologically and/or tectonically coherent areas. TI Team Support Staff member John Vlasity summarized the compilation of available scismicity catalogs into a single catalog covering the region within 200 miles of the site for M3 and larger events (M5 and larger in the high-seismicity area west of Arizona). Subsequently, Resource Experts discussed the Northern Arizona Seismic Network (NASN) established in 1986 (David Brumbaugh) and the recent operation of the IR IS Transportable Array (TA) ( 4-2006 to 3-2009) and subsequent transfer of eight TA stations to ongoing operation as the Arizona Broadband Network (ABN) that sparsely covers western and central Arizona (Jeri Young). It was noted that one of the TA stations, which was located several miles west of the PNVGS site, was heavily vandalized and the station has been abandoned. The NASN and ABN are jointly called the Arizona Integrated Seismic Network (AISN). It was clear from the presentations and discussions that earthquake monitoring within Arizona has been given a low funding priority historica11y and is operating in a fragile manner through the dedication of a few individuals. This severe restriction of resources may have led lo operational practices that could have impacted the quality of the data being relied on for catalog development. We suggest that the TI Team consider performing a friendly "quality assurance" review of the earthquake monitoring data analysis procedures used for the ABN and NASN. The national standard for seismic network operations is established by the US Geological Survey's Advanced National Seismic System (ANSS); the seismic networks to the west (California) and north (Nevada and Utah) arc members of ANSS. The PVNGS site is within a part or the Southern Basin and Range Province that is characterized by very low seismicity. For example, within 50 miles of the site, there is only one M3+ event in the current catalog and only one event of M<2 recorded during the three years of the TA operation. We think that it would be useful to further quantify the seismicity rate by searching for recordings of earthquakes that are large enough lo be detected but too small to have enough stations to locate. One could start by looking at the three-year TA database using the nine TA stations roughly centered on the station closest to the PVNGS site. These data could be helpful in providing a more refined subdivision of the seismicity patterns associated with the Southern Basin and Range Province, and thereby used for refining the areal sources used in smoothing seismicity for areal source rates. Some of the initial results for computing rates for area] sources using the base case PPRP Letter #3: PVNGS SSC WS l Dr. Ross D. Hartleb 4 FINAL 6/5/13 model, as discussed by Melanie Walling, were startlingly high given the observed low seismicity within 50 miles of the PNVGS site. In consideration of the limitations of the current earthquake monitoring networks in Arizona, it might be reasonable for Arizona Public Service. on behalf of its PVNGS. to consider installing one or more seismic monitoring stations for specific data targets relating Lo the current project and for future use regarding seismic hazards related to licensing. As noted in the above comments, the paucity of seismic monitoring data in the low-scismicity environment of PVNGS has both positive and negative aspects. Herc arc several possible deployments that could be useful in the short term (the current project) and in the long term (future licensing matters). a. Given the location of surface bedrock within several miles of the PVNGS site, a broadband station comparable to the vandalized TA station could be installed at a reasonably secure location with data telemetered to a central recording site (potentially operated by the AISN). b. Several additional short-period seismographic stations could be installed to form a small array around the central station to improve the detection and location of occurring earthquakes. These data would be used to refine the seismicity model used for areal sources. c. It has been suggested that a strong-motion station be installed within the site perimeter to collect data on kappa for the site. It could be useful to operate similar strong-motion instruments along with the stations described in items (a) and (b) above. These possible seismic monitoring installations would best be considered in the context of both the near-term application of the data for the current project (a few years) and the longer-term interests of APS with regard to the role of seismic issues in future operational considerations at PVNGS. 2. Geologic data on the presence or absence of fault sources within 40 km of the PVNGS site. Although the PPRP has not seen a specific discussion of the site geology. it's clear that the existing geologic database, in terms of published geologic mapping, is variable in quality, scale (i.e., 1 :24,000 to 1 :250.000 scale), and distribution. There is no modern detailed map of the site and surrounding region. such as a 40 km radius. but it would be a valuable addition to the study in that it would help determine the presence or absence of fault sources within 40 km of the PVNGS site. Such a map could be constructed using existing source maps, such as the Wintersburg 7.5' quadrangle, and extending the map units out 40 km from the site. This mapping could be based largely on photogeologic interpretation in areas of low-quality reconnaissance mapping. Google Earth imagery provides a valuable, low-cost resource for such mapping, and such mapping would augment the reconnaissance Quaternary fault mapping that Arizona performed some two decades ago. Without a map showing the detailed Quaternary geology of the region. it will be difficult to preclude the presence or absence of capable fault sources. An example of the value of such mapping is the near-site faults mentioned in the field trip report PPRP Letter #3: PVNGS SSC WS 1 Dr. Ross D. Hartleb 5 FINAL 6/5/13 CPPRP Letter #2). The detailed Quaternary geologic map in the Wintersburg 7.5' quadrangle shows that the mapped bedrock faults, which trend beneath the PVNGS site, do not disturb Quaternary alluvial units of middle Pleistocene age (hundreds of thousands of years old), and thus show no evidence of young activity. Please contact us if you wish further discussion of any of our observations and comments. Sincerely yours, Dr. William U. Savage (Chair) Mr. Michael N. Machette Dr. Thomas K. Rockwell PPRP Letter #3: PVNGS SSC WS I To: From:

Subject:

Dear Sirs,

William Savage (Participatory Peer Review Panel (PPRP) chair) Michael Machette (PPRP member) Thomas Rockwell (PPRP member) William Lett is (Project Technical Integrator (PTI)) July 15, 2013 Scott Lindvall (Seismic Source Characterization (SSC) Technical Integrator (Tl) Team Lead) Ross Hartleb (Lettis Consultants International (LCI) Project Manager) Response to observations and comments from the PPRP on Workshop #1 Palo Verde Nuclear Generating Station (PVNGS) Seismic Hazard Evaluation Project Senior Seismic Hazard Analysis Committee (SSHAC) Level 3 SSC This letter provides our response to observations and comments from the PPRP's Letter No. 3 dated June 5, 2013 on the PVNGS SSC Workshop #1 ("Significant Issues and Data Needs"), which was held on April 9-10, 2013. We appreciate the PPRP's thoughtful review of both the SSHAC process and the technical issues presented at Workshop #1. The PPRP's Letter No. 3 includes both general observations and specific comments on Workshop #1, some of which contain underlined passages. As requested by the PPRP, we provide in this letter our responses to the underlined portions of the PPRP's observations and comments. General Observations PPRP General Observation: "For the purpose of improving the collegiality and communication during the Workshop, it would have been helpful to have been provided brief bios (name and titles, organization, technical area of interest, role in the project) for each of the meeting participants so that each participant could more quickly establish an intellectual and conversational relationship with his or her peers. It would also be helpful for future meetings to provide name tents for the table for each individual. Name tags should have the preferred nickname of the individual and project role or home organization." Response: The Tl Team concurs with this general observation and will implement these helpful suggestions at future workshops. PPRP General Observation: "For future meetings, it would be useful to check the brightness of the room and the positioning of the projector(s) with respect to the screen(s) to assure that people in the back of the room can see the most detailed slides with reasonable clarity. The PPRP noted that several presenters commented that they had difficulty seeing their own projected images clearly." Page 1of4 Response to observations and comments from the PPRP on Workshop #1-July 15, 2013 Response: The Tl Team concurs with this general observation and will take the recommended steps to ensure improved visibility and legibility of presentations at future workshops. Specific Comments PPRP Comment #1.1: "It was clear from the presentations and discussions that earthquake monitoring within Arizona has been given a low funding priority historically and is operating in a fragile manner through the dedication of a few individuals. This severe restriction of resources may have led to operational practices that could have impacted the quality of the data being relied on for catalog development. We suggest that the Tl Team consider performing a friendly "quality assurance" review of the earthquake monitoring data analysis procedures used for the ABN and NASN. The national standard for seismic network operations is established by the US Geological Survey's Advanced National Seismic System {ANSS); the seismic networks to the west {California) and north {Nevada and Utah) are members of ANSS.11 Response to PPRP Comment #1.1: To the extent possible, the Tl Team will perform the recommended "friendly quality assurance review" of the data analysis procedures of the Arizona Broadband Network (ABN) and the Northern Arizona Seismic Network (NASN), which collectively comprise the Arizona Integrated Seismic Network (AISN). To our knowledge, operational procedures for these networks are not published and are not readily available. The Tl Team will contact Jeri Young (Arizona Geological Survey) and David Brumbaugh (Northern Arizona University) to see if such procedures are available for the ABN and NASN, respectively, for Tl Team review. The Tl Team will use this information to evaluate quality and uncertainty of the data to inform our judgment when weighting alternatives in the SSC, but will not evaluate earthquakes in those earthquake catalogs. PPRP Comment #1.2: "We think that it would be useful to further quantify the seismicity rate by searching for recordings of earthquakes that are large enough to be detected but too small to have enough stations to locate. One could start by looking at the three-year TA database using the nine TA stations roughly centered on the station closest to the PVNGS site. These data could be helpful in providing a more refined subdivision of the seismicity patterns associated with the Southern Basin and Range Province, and thereby used for refining the areal sources used in smoothing seismicity for areal source rates." Response to PPRP Comment #1.2: Many of the earthquakes recorded in the PVNGS study region during the three-year window of the Transportable Array (TA) have magnitudes that are below the lower magnitude cutoff (Mw 2.7) for inclusion in the project earthquake catalog. The Tl Team agrees, however, that the TA earthquakes may be useful, in particular for evaluating seismicity rates and patterns within the study region and possibly to provide additional information or insights on seismicity rates. As such, the Tl Team will continue to investigate the TA earthquake data to assess alternate ways to capture uncertainty in the SSC. These investigations likely will include sensitivity analyses intended to assess the impacts of various modeling decisions on seismic hazard at the PVNGS site. PPRP Comment #1.3: "In consideration of the limitations of the current earthquake monitoring networks in Arizona, it might be reasonable for Arizona Public Service, on behalf of its PVNGS, to consider installing one or more seismic monitoring stations for specific data targets relating to the current project and for future use regarding seismic hazards related to licensing. As noted in the above comments, the paucity of seismic monitoring data in the low-seismicity environment of PVNGS has both positive and negative Page 2 of 4 Response to observations and comments from the PPRP on Workshop #1-July 15, 2013 aspects. Here ore several possible deployments that could be useful in the short term (the current project) and in the long term (future licensing matters). a. Given the location of surface bedrock within several miles of the PVNGS site, o broadband station comparable to the vandalized TA station could be installed at o reasonably secure location with data telemetered to a central recording site (potentially operated by the A/SN). b. Several additional short-period seismographic stations could be installed to form a small array around the central station to improve the detection and location of occurring earthquakes. These data would be used to refine the seismicity model used for areal sources. c. It has been suggested that a strong-motion station be installed within the site perimeter to collect data on kappa for the site. It could be useful to operate similar strong-motion instruments along with the stations described in items (a) and {b) above. These possible seismic monitoring installations would best be considered in the context of both the term application of the data for the current project (a few years) and the longer-term interests of APS with regard to the role of seismic issues in future operational considerations at PVNGS. 11 Response to PPRP Comment #1.3: The Tl Team agrees that installation of a seismograph or seismographs at or near the PVNGS site would provide useful data both for the current project and for the longer-term interests of Arizona Public Service (APS). Specifically, these data would provide improved earthquake monitoring and reduction of uncertainty on site kappa and other ground motion parameters. The installation of new instrumentation, however, is beyond the scope of the current project. We are in current discussions with APS and Westinghouse Electric Company (WEC) regarding the possibility of obtaining additional budget to install, operate, and maintain this new instrumentation and to determine who would receive and support interpretation of any new data. To maximize benefits to the current project, the Tl Team understands that any new instrumentation should be installed as soon as possible to maximize the number of earthquakes recorded in this low-seismicity environment. PPRP Comment #2: "Although the PPRP has not seen a specific discussion of the site geology, it's clear that the existing geologic database, in terms of published geologic mapping, is variable in quality, scale (i.e., 1:24,000 to 1:250,000 scale), and distribution. There is no modern detailed map of the site and surrounding region, such as a 40 km radius, but it would be a valuable addition to the study in that it would help determine the presence or absence of fault sources within 40 km of the PVNGS site. Such a map could be constructed using existing source maps, such as the Wintersburg 7.5' quadrangle, and extending the map units out 40 km from the site. This mapping could be based largely on photogeologic interpretation in areas of low-quality reconnaissance mapping. Google Earth imagery provides a valuable, low-cost resource for such mopping, and such mapping would augment the reconnaissance Quaternary fault mopping that Arizona performed some two decades ago. Without a map showing the detailed Quaternary geology of the region, it will be difficult to preclude the presence or absence of capable fault sources. An example of the value of such mopping is the near-site faults mentioned in the field trip report (PPRP Letter #2). The detailed Quaternary geologic mop in the Wintersburg 7.5' quadrangle shows that the mopped bedrock faults, which trend beneath the PVNGS site, do not disturb Quaternary alluvial units of middle Pleistocene age (hundreds of thousands of years old), and thus show no evidence of young activity." Response to PPRP Comment #2: Presentations and discussions at Workshop #1 identified Quaternary geologic mapping of the site vicinity (within 40 km of the site) as a data need. The Tl Team agrees that a Quaternary geologic map of the site vicinity would help reduce uncertainty regarding the presence or absence of near-site fault Page 3 of 4 Response to observations and comments from the PPRP on Workshop #1-July 15, 2013 sources, thus providing benefit to the PVNGS Seismic Hazard Evaluation Project. The development of such a map, however, is beyond the scope of the current project. We will discuss with APS and WEC the possibility of obtaining additional budget to produce a Quaternary geologic map of the site vicinity or key portions of the site vicinity. This map would need to be available to the Tl Team well in advance of Workshop #3 for incorporation in the PVNGS SSC. Regardless of whether additional budget is secured for Quaternary geologic mapping of the site vicinity, the Tl Team will evaluate the degree to which the development of a reconnaissance-level Quaternary geologic map is feasible under the current project scope. Likewise, we will follow-up with Resource Expert Philip Pearthree to establish more clearly the degree to which he and others at the Arizona Geological Survey have systematically and thoroughly investigated the site vicinity for the presence or absence of Quaternary-active faults. Closure We appreciate the comments from the PPRP on Workshop #1 and suggestions for improvement to the ongoing Palo Verde Seismic Hazard Evaluation Project. We are incorporating your observations, suggestions, and recommendations into our program to the extent possible. We look forward to seeing you again at Workshop #2 and to sharing with you our additional progress on the project at that time. Sincerely, (JJ,.fi_ kfL William Lettis PTI ,... .... . I I \ \..(-> 1 "1.:: I * \ , .. * * *. , \ Ross Hartleb LCI Project Manager Scott Lindvall SSC Tl Team Lead Page 4 of 4 October 23, 2013 Dr. Ross D. Hartleb LCI Project Manager, Palo Verde NGS Seismic Hazard Evaluation Project Lettis Consultants International, Inc. 27441 Tourney Road, Suile 220 Valencia, CA 91335

SUBJECT:

Seismic Source Characterization Participalory Peer Review Panel Lener No. 4: Palo Verde Nuclear Generating Station Seismic Hazard Evaluation Project, Workshop No. 2: Alternative Interpretations

Dear Dr. Hartleb:

This letter provides the report of the Seismic Source Characterization (SSC) Participatory Peer Review Panel (PPRP) on the Palo Verde Nuclear Generating Station (PVNGS) Seismic Hazard Evaluation Project Workshop No. 2 (WS2). The workshop was held on September 24-25, 2013, at the conference facilities of the Wigwam Resort in Litchfield Park, AZ. WS2 is identified as Task 6 in the current version of the SSC Project Plan, daled February 19, 2013, and the goals of this workshop are prescribed in Section 4.6.2 of NUREG-2117. In accord with these guidance documents, the PPRP attended WS2 as observers during the daily proceedings of the two-day workshop to become informed by the presentations and discussions, and to review both the technical and procedural aspects of the workshop. All three members of the PPRP (M. Machelle, T. Rockwell, and W. Savage) attended WS2 and observed all aspects of the workshop. The PPRP met at the end of each day with the TI lead, Tl Team members, and Sponsor representative to provide verbal commenls that could be used during the course of the ongoing workshop and in preparing this letter report. The PPRP appreciated the preparations for and conduct of the workshop in terms of the hospilalily and professionalism of the Sponsor and the Project Team and their staff. The well-planned agenda for the technical presentations and discussions was efficiently followed and led to successful execution of the full agenda of the workshop. The comfortable facilities and attentive staff of the Wigwam Resort also contributed to the effectiveness of the workshop. The PPRP noted lhal suggested improvemenls in the logistics of the meeting having to do with the meeting room layout, improving the visibility of the projection screens, and providing table-top name placards and a list containing brief summaries of professional backgrounds of the participants were very satisfactorily accomplished. In the opinion of lhe PPRP, W. Lellis efficienlly and engagingly presented the training on SSHAC methodology and workshop rules using a revised format. PPRP Letter #4: PVNGS SSC WS2 Dr. Ross D. Hartlcb 2 Final 10/23/13 The PPRP's general observations as well as specific comments and recommendations arc provided in the remainder of this letter report. Those parts of the comments that require a wrillen response from the TI Team are underlined for clarity. General Observations Regarding the Workshop Process The agenda for Lhe technical portion of the workshop began with a sel or presentations by the TI Team that focused on the key technical issues of the SSHAC Level 3 Seismic Source Characterization. This information was particularly useful for informing the new Proponent Experts (PEs) attending the workshop. The PPRP was pleased to see well-focused presentations that covered the entire range of alternative views. The Tl team did an excellent job of selecting the PEs to achieve the observed diversity of interpretations. The provision of targeted questions to the PEs worked very well to focus Lheir comments, and the PEs explicitly responded Lo these questions, in some cases by including them in their presentations; this enabled the TI team to have documentation of the responses. There were three excellent talks on geodesy Lhat elucidaled the discrepancy between geologic and geodetic crustal deformation rates, which are an important component of this project. The geodetic model presented by R. Bennett places most or all of the active deformation in the Transition Zone to the east of the southern Basin and Range, whereas the olhers show the geodelic deformation more as a strain gradient. Resolution of current geodetic rates and their rectification with the lack of geologic expression of deformation. and whether the current rates arc a transient feature in the strain field, arc both issues critical to the correct assessment of hazard. Toward that end, the documentation of unfaulted old piedmont surfaces in the sile vicinity ( 40 km radius) will be critical in demonstrating the absence of the potential for faulting in the site vicinity. as discussed below. Specific Comments on Significant Issues and Data Needs The assessment of the potential for surface faulting in the site vicinity can be efficiently addressed by documenting the locations and extents of older geomorphic piedmont remnants in the landscape. Specifically, targeted mapping of paleosurfaces with slrong soil development (Stage III and stronger CaC03 morphology) will demonstrate the significant age (105 years and older) of surfaces that can then be interrogated for the presence of fault scarps and other signs of deformation. Documentation of the absence of fault-relaled features is direct evidence that Lhese ancient surfaces have not suslained surface rupture in at least I 00,000 years and therefore demonstrates the absence of active faults in the site vicinity that could potentially affect the PVNGS in the future. LCI should be complimented on pursuing evidence for large surface faulls within the 400 km site radius that transects northern Mexico. This study using Google Earth is an efficient way to augment sparse data. However, the PPRP recommends that this type of reconnaissance be extended into southern Arizona within the 400-km radius. The existing PPRP Letter #4: PVNGS SSC WS2 Dr. Ross D. Hartlcb 3 Final 10/23/13 fault mapping in this region of Arizona was conducted in the early 1980s using I: 110,000-scale U2 photographs, in which the scale may limit detection of active faults. A modern landscape analysis and search for potentially active seismic sources, using the Google Earth platform, would assure that there are not additional unmapped seismic sources that may potentially affect PVNGS operations. Proposals for Additional Work Although potential additional work was mentioned only briefly during the formal workshop, the PPRP met subsequently with the Tl team to discuss the status of planned proposals to APS for additional work. The PPRP Letter #3 dated 6/5/13 commented on two areas of data needs regarding (1) improving near-regional seismicity monitoring, and (2) collecting field geologic data for constraining the presence of active faults within the site vicinity (a radius of 40 km). In addition, we understand that additional data collection for refining the site response in the sedimentary materials beneath the plant site is being considered for the site ground motion characterization.

• Quaternary geology and mapping: This proposal focuses on improving the detailed geology of the site area (5 miles/8 km radius) and making a reconnaissance map (25 miles/40 km radius) of the old landforms (piedmont surfaces and bedrock pediments) that provide a basis for precluding the presence of faulting in the past l 00,000 years or more. These basic geologic data are critical for determining whether there are faults capable of generating strong ground motion near the site.
• Seismicity monitoring: This proposal focuses on procuring and installing new broadband and strong-motion instrumentation at the PVNGS site in a borehole drilled for this purpose to bedrock, a depth of about 500 feet beneath the site. The purpose of the instrumentation is to collect data for (I) detection and improved location of earthquakes (-Ml and larger events) in the central part of the southern Basin and Range province including near the Palo Verde site, and (2) refining the value of kappa at the site using primarily weak ground motions from local or regional earthquakes. The instrumentation would be operated initia11y as a freestanding system recording in a triggered mode, prior to establishing more permanent power and Internet data communications for longer-term operation.
• Obtaining additional subsurface geotcchnical site-response information on the shallow velocity structure beneath the power plant: This proposal intends to conduct borehole and downhole Vs data collection prior to the installation of earthquake monitoring instrumentation in the borehole. The PPRP endorses and strongly supports the funding and implementation of these work items as soon as possible. APS has indicated that funding may be available for new work if it is well justified. The PPRP urges that a high priority be placed on implementing these work items at the earliest possible dates in order that the data may be obtained in a timely manner. For example, the new geologic mapping should be completed and PPRP Letter #4: PVNGS SSC WS2 Dr. Ross D. Hartlcb 4 Final 10/23/13 reviewed by the PPRP prior to Workshop No. 3, which is scheduled in February 2014. We assume that the GMC PPRP is independently reviewing the site response and other ground-motion aspects of the proposals for additional work. Conclusions The PPRP considers that Workshop No. 2 was a highly successful meeting where alternative SSC views and models were presented and discussed, thus providing the basis to proceed with the SSC model development, as required by the SSHAC process. Please contact us if you wish further discussion of any of our observations and comments. Sincerely yours, ;1* / . -. .,,: J*' . "' -.J.:* "-*/ ,.., _ _..,._,,,, "?--* , .. * '-:,.. * -s--./ Dr. William U. Savage (Chair) Mr. Michael N. Machette Dr. Thomas K. Rockwell (-' PPRP Letter #4: PVNGS SSC WS2 To: From:

Subject:

Dear Sirs,

William Savage (Participatory Peer Review Panel (PPRP) chair) Michael Machette (PPRP member) Thomas Rockwell (PPRP member) William Lett is (Project Technical Integrator (PTI)) November 26, 2013 Scott Lindvall (Seismic Source Characterization (SSC) Technical Integrator (Tl) Team Lead) Ross Hartleb (Lettis Consultants International (LCI) Project Manager) Response to observations and comments from the PPRP on Workshop #2 Palo Verde Nuclear Generating Station (PVNGS) Seismic Hazard Evaluation Project Senior Seismic Hazard Analysis Committee (SSHAC) Level 3 SSC This letter provides our response to observations and comments from the PPRP's Letter No. 4 dated October 23, 2013 on the PVNGS SSC Workshop #2 ("Alternative Interpretations"), which was held on September 24-25, 2013. We appreciate the PPRP's thoughtful review of both the SSHAC process and the technical issues presented at Workshop #2. The PPRP's Letter No. 4 includes both general observations and specific comments on Workshop #2, some of which contain underlined passages. As requested by the PPRP, we provide in this letter our responses to the underlined portions of the PPRP's observations and comments. General Observations PPRP General Observation: "Resolution of current geodetic rates and their rectification with the lack of geologic expression of deformation, and whether the current rates are a transient feature in the strain field, are both issues critical to the correct assessment of hazard. Toward that end, the documentation of unfaulted old piedmont surfaces in the site vicinity (40 km radius) will be critical in demonstrating the absence of the potential for faulting in the site vicinity, as discussed below." Response: The Tl team acknowledges the potential importance of, and the uncertainty associated with, geodetic data for the Palo Verde region. The question of how to incorporate geodetic data into the SSC will be carefully investigated and debated by the Tl team. Additionally, the Tl team will continue to engage Proponent Experts Richard Bennett (University of Arizona), Peter Bird (University of California at Los Angeles), Cornelius Kreemer (University of Nevada at Reno), and others to further explore the utility and limitations of geodetic data from the site region. As described below, newly proposed Quaternary geologic mapping of the site area (8 km radius) and reconnaissance-level Quaternary mapping of the site vicinity (40 km radius) will be used to evaluate the presence or absence of Quaternary surface faulting in the vicinity of the PVNGS. Page 1of3 Response to observations and comments from the PPRP on Workshop #2 -November 26, 2013 Specific Comments PPRP Comment #1: "The PPRP recommends that this type of reconnaissance be extended into southern Arizona within the 400-km radius." Response to PPRP Comment #1: The Tl team agrees that it is important to perform a level fault screening study for Arizona to assess whether there is evidence for capable fault sources in the PVNGS region that are not included in the current base-case SSC model. Thus, the Tl team will perform a screening study for large surface faults within the Arizona portion of the site region. Similar to the fault screening performed for northern Sonora and described at Workshop #2, the Tl team's new fault screening for Arizona largely will be based on Google Earth imagery, but also will utilize other data sets where available (e.g., the limited lidar data available for the Arizona-Mexico border area). Unlike the Sonora fault screening, the new Arizona fault screening will build on available data like the U.S. Geological Survey's Quaternary fault and fold database and the draft update to that database provided to the Tl team by Philip Pearthree (Arizona Geological Survey). A major benefit of this new fault screening is that it will bring the entire SSC model region closer to a common state of knowledge. PPRP Comment #2: "The PPRP endorses and strongly supports the funding and implementation of these work items as soon as possible.11 Response to PPRP Comment #2: Arizona Public Service (APS), LCI, and the Tl team are working together to implement three newly proposed work items, including Quaternary geologic mapping in the site area and site vicinity, installation of a down hole seismograph array at the site, and collection of Spectral Analysis of Surface Waves (SASW) data at the site. In a recent teleconference with LCI, APS indicated their intention to fund the three new proposals. During that call, however, APS indicated that funding for the new work largely will not be available until early in 2014, with the exception that procurement of seismograph instrumentation is underway so that it will be available for installation as early as possible in 2014. PPRP Comment #3: '7he PPRP urges that a high priority be placed on implementing these work items at the earliest possible dates in order that the data may be obtained in a timely manner. For example, the new geologic mapping should be completed and reviewed by the PPRP prior to Workshop No. 3, which is scheduled in February 2014. We assume that the GMC PPRP is independently reviewing the site response and other ground-motion aspects of the proposals for additional work.11 Response to PPRP Comment #3: As described above, APS, LCI and the Tl team are working together to implement the newly proposed work items as soon as possible. Field review by the PPRP of the new geologic mapping activities is planned for early February, 2014. It is anticipated that mapping activities will be ongoing at that time, thus allowing for input from the PPRP to be considered prior to finalization of mapping. Workshop #3 is postponed from February until April to allow additional time for the project team to complete newly proposed activities, especially the geologic mapping, and to incorporate this new information into the SSC. LCI has provided its SASW and seismograph array proposals to Carola DiAlessandro, Project Manager for the Southwestern United States Ground Motion Characterization (SWUS GMC) project, for their information. Closure We appreciate the comments from the PPRP on Workshop #2 and suggestions for improvement to the ongoing Palo Verde Seismic Hazard Evaluation Project. We are incorporating your observations, Page 2 of 3 Response to observations and comments from the PPRP on Workshop #2 -November 26, 2013 suggestions, and recommendations into our program to the extent possible. We look forward to seeing you again at Workshop #3 and to sharing with you our additional progress on the project at that time. Sincerely, k:fk* William Lettis PTISSC , '* . ... '., Ross Hartleb LCI Project Manager Page 3 of 3 Scott Lindvall Tl Team Lead March 26, 2014 Dr. Ross D. Hartleb LCI Project Manager, Palo Verde NGS Seismic Hazard Evaluation Project Lettis Consultants International, Inc. 27441 Tourney Road, Suile 220 Valencia, CA 91335

SUBJECT:

Seismic Source Characterization Participalory Peer Review Panel Lener No. 5: Palo Verde Nuclear Generating Station Seismic Hazard Evaluation Project, Field Review of Geologic Mapping

Dear Dr. Hartleb:

This letter constitutes the report of the Participatory Peer Review Panel (PPRP) on the Palo Verde Nuclear Generaling Station (PVNGS) Seismic Hazard Evaluation Project's 2.5-day Field Review of Geologic Mapping. The Field Review was held on February 4-6, 2014, at the conference facilities of the Wigwam Resort in Litchfield Park, AZ and at selected field localities within about 60 km of the PVNGS site. The work to be reviewed was recommended by the PPRP in our Lener No. 4 daled October 19, 2013. The scope of work suggested by the PPRP was as follows:

• Quaternary geology and mapping: This proposal focuses on improving the detailed geology of the site area (5 miles/8 km radius) and making a reconnaissance map (25 miles/40 km) of the old landforms (piedmont surfaces and bedrock pediments) that provide a basis for precluding the presence of active faulting. These basic geologic data are critical for determining whether there are faults capable of generating strong ground motion near the sile. The scope of work approved by Arizona Public Service is included in the Project Plan for Quaternary Geologic Mapping in the Vicinity of the Palo Verde Nuclear Generating Station, prepared by LCI and daled March 3, 2014. The PPRP received a draft version of this Project Plan for review and discussion during the February 4-6 Field Review. The PPRP finds that the March 3, 2014, Project Plan is a satisfactory response to the PPRP's suggested scope of work. Those parts of these comments that require a written response from the TI Team are underlined for clarity. It was our understanding that the purpose of the Field Review was to provide early feedback to the PVNGS Project management and the personnel performing the field investigations. The decision by PVNGS to proceed with the above scope of work reflects well on their commitment to achieve a robust and state-of-the-art understanding of potential seismic hazards within relatively close proximity to the PVNGS site. PPRP Letter #5: PVNGS SSC Field Review Feb 4-6, 2014 Dr. Ross D. Hartlcb 2 FINAL 3/26/14 The personnel listed in the Project Plan arc experienced and knowledgeable about the regional geology and its faults and their activity. and the PPRP is confident that they possess Lhe skills to carry oul the projecl successfully. These individuals consist of: LCI Project Manager and Senior Geologist Ross Hartleb LCI Senior Principal Geologist Scott Lindvall LCI Senior Project Geologist Richard Ortiz In addition, LCI has engaged consultants that are specifically knowledgeable about the project area, having worked in the region for years. These individuals arc: Philip Pearthree, Arizona Geological Survey, Senior Research Geologist, Jeri Young, Arizona Geological Survey, Senior Research Geologist Results of the Field Review LCI personnel and their consultants conducted a two-day field review that focused on techniques for differentiating ages of Quaternary units and afforded us the opportunity to inspect the project area and visit two key fault localities. During and immediately following the Field Review, the PPRP discussed with the LCI personnel and consultants the various aspects of the procedures to be used to conduct the new work. These comments and discussions were used by LCI to finalize the March 3, 2014, Projecl Plan. Day I (February 4): The focus of this day's field review was the explanation and demonstration of the procedures used to assess the age of Quaternary deposits within the 40-km radius (site vicinity) from the PNVGS site. Geologist Pearthree explained the observational approach and criteria that he and others have been using in the AZGS for detailed mapping in the Phoenix region. We visited a half-dozen sites in the Wintersburg 7.5-minute quadrangle (location of the PVNGS) to familiarize ourselves with soils on these deposits and their characteristic landforms, which will be used in the 8-km-and 40-km-radius mapping efforts. Particularly enlightening were the strong development of calcic soils on older deposits and surfaces. which will be the focus of defining I 00 ka and older landforms. The PPRP members were impressed by the effectiveness of the qualitative criteria used by Pearthree and Young to rapidly and confidently assess the ages of the surfaces at each locality. The PPRP felt that the procedure used and the nomenclature developed to classify the Quaternary deposits at each locality were based on established and defcndablc geomorphic and soil criteria and would be accepted by peers in the greater technical community. Day 2 (February 5, first stop): With the background from the first day, the LCI personnel and consultants escorted the PPRP to two fault localities where faults had been previously identified. At the first locality, about 60 km SSE of the PVNGS sile, the characteristics of the Sand Tank fault were discussed, including discussion of the trenching work that had been carried out previously by Dr. Pearthrcc and others. Procedures and technologies associated with detecting surface fault ruptures at other PPRP Letter #5: PVNGS SSC Field Review Feb 4-6, 2014 Dr. Ross D. Hartlcb 3 FINAL 3/26/14 localities in the site vicinity were discussed, with particular reliance on imagery available on Google Earth. The PPRP felt confident that the strategy of using Google Earth imagery combined with expertise in the kinds of features associated with surface fault rupture (chiefly long-term changes in the pattern of sediment removal or accumulation following the formation of fault scarps) was well understood by the Project personnel and consultants and would provide a high degree of confidence in being able to either demonstrate the existence of previously unidentified surface fault ruptures or demonstrate the absence of such faulting within the study region surrounding the PVNGS site. Day 2 (February 5, second stop): At this stop, the PPRP were taken to the location of the unnamed east-west-trending fault that was mapped by Gilbert (199 l) as a bedrock fault located west of the Gila River valley and suspected of being active. The group hiked along much of the discontinuously exposed trace of the fault and discussed evidence of its location and possible recency of activity. In this brief review, no evidence was found suggesting any recent (Quaternary) activity, but further study using the techniques discussed at the first stop was thought to be applicable to the two ends of the fault trace that trend beneath sediments, and within the 40-km-radius site vicinity. The PPRP considers this procedure to be an appropriate way to assess the potential for future activity by this and other known bedrock faults within the site vicinity. Day 3 (February 6, morning): The PPRP met with the LCJ personnel to briefly discuss the methodology used and the observations made during the Field Review. The PPRP met separately to discuss our observations and conclusions. Conclusions The PPRP is satisfied that the additional fieldwork has been planned in a scientifically sound manner with appropriate investigative procedures and well-qualified individuals performing the work. Because this Field Review was held prior to the completion of the planned field investigations. the PPRP recommends that additional time be allocated just before or during Workshop 3 for a detailed presentation of the results of the completed Quaternary Geologic Mapping as applied to evaluating the possible presence and seismic potential of as-yet unidentified active faults within 40 km of the PVNGS site. We also acknowledge the expertise and experience of all the members of the Field Review team, and expect that the results of the Quaternary Geologic Mapping study will be a valuable contribution to the Probabilistic Seismic Hazard Assessments for the Palo Verde Nuclear Generation Station. Please contact us if you wish further discussion of any of our observations and comments. PPRP Letter #5: PVNGS SSC Field Review Feb 4-6, 2014 Dr. Ross D. Hartlcb Sincerely yours, Dr. William U. Savage (Chair) Mr. Michael N. Machette Dr. Thomas K. Rockwell

Reference:

4 FINAL 3/26/14 Gilbert, W. G. ( 1991). Bedrock Geology of the Eastern Gila Bend Mountains, Maricopa County, Arizona; Arizona Geological Survey, Open-File Report 91-5. PPRP Letter #5: PVNGS SSC Field Review Feb 4-6, 2014 To: From:

Subject:

Dear Sirs,

William Savage (Participatory Peer Review Panel (PPRP) chair) Michael Machette (PPRP member) Thomas Rockwell (PPRP member) Ross Hartleb (Lettis Consultants International (LCI) Project Manager) March 26, 2014 Scott Lindvall (Seismic Source Characterization (SSC) Technical Integrator (Tl) Team Lead) Response to comment from the PPRP on field review of geologic mapping Palo Verde Nuclear Generating Station (PVNGS) Seismic Hazard Evaluation Project Senior Seismic Hazard Analysis Committee (SSHAC) Level 3 SSC This letter provides our response to the PPRP's Letter No. 5 dated March 26, 2014 on their field review of Quaternary geologic mapping in the vicinity of the PVNGS. On February 4-6, 2014, the PPRP joined geologists from Lettis Consultants International, Inc. (LCI) and the Arizona Geological Survey (AZGS) to provide early feedback regarding mapping activities that support development of the PVNGS SSC. We appreciate the PPRP's active participation in the field review and their thoughtful comments. The PPRP requested that we respond to one comment in their Letter No. 5. That comment, along with our response, is provided below. PPRP Comment: "Because this Field Review was held prior to the completion of the planned field investigations, the PPRP recommends that additional time be allocated just before or during Workshop 3 for a detailed presentation of the results of the completed Quaternary Geologic Mapping as applied to evaluating the possible presence and seismic potential of as-yet unidentified active faults within 40 km of the PVNGS site." Response: We agree that a detailed presentation and discussion of the results of the Quaternary geologic mapping is warranted. During Workshop #3, we will present an overview of mapping procedures, results, and incorporation into the SSC. If there is interest on the part of the PPRP, we would be happy to hold a more-detailed discussion of the mapping results in the evening following the first day of the workshop, or at another time that is mutually convenient. We appreciate the comments from the PPRP on our Quaternary geologic mapping activities. We look forward to seeing you again at Workshop #3 and to sharing with you our additional progress on the project at that time. Sincerely, l) 1". \ .. \ L v * .\ \ J I). J Ross Hartleb Scott Lindvall May 9, 2014 Dr. Ross D. Hartleb LCI Project Manager, Palo Verde NGS Seismic Hazard Evaluation Project Lettis Consultants International, Inc. 27441 Tourney Road, Suile 220 Valencia, CA 91335

SUBJECT:

Seismic Source Characterization Participalory Peer Review Panel Lener No. 6: Palo Verde Nuclear Generating Station Seismic Hazard Evaluation Project, Workshop No. 3: Preliminary Model and Hazard Feedback

Dear Dr. Hartleb:

This letter provides the report of the Participatory Peer Review Panel (PPRP) on the Palo Verde Nuclear Generating Station (PVNGS) Seismic Hazard Evaluation Project Workshop No. 3 (WS3). The workshop was held on April 23-24, 2014, at the conference facilities of the Marriott Hotel in Walnut Creek, CA. WS3 is identified as Task 8 in the cun-enl version of lhe SSC Project Plan, dated February 19, 2013, and the goals of this workshop are prescribed in Section 4.6.3 of NUREG-2117. In accord with these guidance documents, the PPRP attended WS3 as participants in the discussion of the preliminary SSC model in order to provide feedback to the evaluator experts regarding the manner in which the views of the larger lechnical community have been considered and the range of technically defensible interpretations included. A draft of the Hazard Identification Document (HID) was provided in advance of the workshop. The three members of the PPRP (M. Machecte, T. Rockwell, and W. Savage) attended both days of WS3 and observed and commented during all aspects of the workshop. The PPRP met at the end of each day with the TI Lead, Tl Team members, and the Sponsor representative to provide verbal comments that could be used during the ongoing workshop and in preparing this letter report. General Observations Regarding the Workshop Process The PPRP appreciated the efforts taken by the Tl Team and LCI personnel to prepare for and conducl WS3 in an efficient and highly professional manner. The agenda was thoughtfully planned and resulted in a comprehensive and on-time meeting. The workshop facilitators, Ross Hartleb and Scott Lindva11, were particularly effective in facilitating the various elements of the agenda to assure opportunities for thorough discussions and lo stay on the planned schedule for the two-day meeting. The PPRP members appreciated the seating an-angement for the meeting that placed the PPRP and TI Team leaders on opposite sides of the conference table and close to the projection screen. This arrangement assured that the PPRP members had a clear view of the PPRP Letter #6: PVNGS WS3 April 23-24, 2014 Dr. Ross D. Hartlcb 2 FINAL 5/9/14 PowerPoint figures and could interact with the TI Team leaders efficiently and directly. The individual speakers from the Tl Team were well prepared in delivering their presentations and were responsive to questions and comments from the PPRP members. Complex elements of the presentations (particularly the smoothing and completeness analyses discussed by G. Toro and the preliminary hazard and sensitivity analyses discussed by M. Walling via teleconference call) led to some extensive Q&A discussions, which the PPRP members found very informative. The PPRP observed that there arc several studies and analyses that may be on completion schedules that could impact the timely completion of the project. The PPRP recommends that the TI team prepare a complete schedule of planned meetings and due dates for all products (including reports. analyses. data catalogs, reviews, etc.). and provide a clear identification of how all the products link together to form the documentation of the HID and the PSHA final report. In this schedule, the PPRP members need to be advised as soon as possible when their future participation would be requested in terms of time windows within which document reviews, meeting attendance, and delivering written responses would be requested. Specific Comments on Significant Issues The PPRP has provided the following specific comments. Of these, the ones for which the PPRP would like to receive written responses are underlined. The PPRP would also appreciate a response regarding the schedule for completion identified in the previous paragraph. l. The PPRP acknowledges the detailed and comprehensive nature of the extensive compilation of "Points of Interest" and "Action Items" recorded for WS3 that was prepared by Scott Lindvall. Addressing these items will significantly improve the source characterization. The following PPRP comments address some of the action items that we feel need additional emphasis or specificity. We assume that all of the Action Items will be addressed by the TI Team during the finalization of the HID and the associated Seismic Source Characterization report preparation and documentation. 2. The incorporation of geodetic data in the hazard analysis appears to be incomplete at present. The PPRP suggests that a written plan be prepared and implemented as soon as possible for identifying (1) the relevant geodetic data set(s) to be considered and (2) how the geodetic data contribute to characterizing seismic hazard. Such contributions may result in changes to the HID. 3. During the meeting, Gabriel Toro discussed the analysis of uncertainty in using seismicity data for expressing seismic hazard in substantial detail, which proved to be quite informative. Preparation of a succinct narrative and more complete documentation of the analytical tool called "smoothing" during the meeting should be considered so that reviews of the analyses can be carried out in an informed and efficient manner. PPRP Letter #6: PVNGS WS3 April 23-24, 2014 Dr. Ross D. Hartleb 3 FINAL 5/9/14 4. Some uncertainty in the nature of the M>4.65 seismic events mapped on the west side of the Southern Basin and Range province just east of the Gulf of California was noted in the meeting. Conducting a review of the earthquakes comprising these events should be considered to determine if they are located on land or are associated with faulting within the Gulf. If they arc pre-instrumental (or otherwise poorly located), efforts could be made to reposition the events. 5. The nature of the observed surface displacements on the Sand Tank fault should be considered to assess the observations in terms of average and/or maximum fault displacement values. Comparisons could he made with historic normal fault ruptures with detailed displacement envelopes (e.g., 1959 Hebgen Lake, 1983 Borah Peak, etc.) to determine an average offset if the maximum is roughly 2 m. In addition, Phil Pearthree could be asked whether the scarp profiles measured across the fault arc long enough to detect far-field deformation. Such information could be gathered easily using modem precision GPS instrumentation. 6. The two-zone model for areal seismic sources may be unrealistic based on the level of geologic data that are available, and thus its usefulness should be reconsidered. The positions of zone boundaries in the seven-zone model could be reexamined to include a possible extension of the transition zone to the west to include faults and seismicity that arc concentrated between the 320-and 400-km radii. Similarly, we sec no reason not to absorb the ETR zone into the SCABA zone as discussed at the Workshop. This would result in a new 6-zone model that would be either the only model or the dominantly weighted model. 7. As part of the detailed Quaternary mapping fault studies for the site vicinity, the potential for Quaternary active faults located within the modern alluvial drainages should be considered. The north-south continuity of many of the surficial deposits provide valuable datums for excluding perpendicular (E-W) faults, but one could argue that significant (I 0-20 km long) N-S oriented faults could lurk beneath major river channels and their adjacent Holocene deposits. Conclusions The PPRP considers Workshop No. 3 to have been a successful forum for presenting the PVNGS Preliminary hazard model and generating useful feedback. Dr. William U. Savage (Chair) Mr. Michael N. Machelle Dr. Thomas K. Rockwell PPRP Letter #6: PVNGS WS3 April 23-24, 2014 To: From:

Subject:

Dear Sirs,

William Savage (Participatory Peer Review Panel (PPRP) chair) Michael Machette (PPRP member) Thomas Rockwell (PPRP member) William Lett is (Project Technical Integrator (PTI)) May 14, 2014 Scott Lindvall (Seismic Source Characterization (SSC) Technical Integrator (Tl) Team Lead) Ross Hartleb (Lettis Consultants International (LCI) Project Manager) Response to observations and comments from the PPRP on Workshop #3 Palo Verde Nuclear Generating Station (PVNGS) Seismic Hazard Evaluation Project Senior Seismic Hazard Analysis Committee (SSHAC) Level 3 SSC This letter provides our response to observations and comments from the PPRP's Letter No. 6 dated May 9, 2014 on the PVNGS SSC Workshop #3 ("Preliminary Model and Hazard Feedback"), which was held on April 23-24, 2014. We appreciate the PPRP's thoughtful review of both the SSHAC process and the technical issues presented at Workshop #3. The PPRP's Letter No. 6 includes both general observations and specific comments on Workshop #3, some of which contain underlined passages. As requested by the PPRP, we provide in this letter our responses to the underlined portions of the PPRP's observations and comments. General Observations PPRP General Observation: "The PPRP observed that there are several studies and analyses that may be on completion schedules that could impact the timely completion of the project. The PPRP recommends that the Tl team prepare a complete schedule of planned meetings and due dates for all products (including reports, analyses, data catalogs, reviews, etc.), and provide a clear identification of how all the products link together to form the documentation of the HID and the PSHA final report." Response: The Tl team will prepare and distribute to the PPRP a detailed project schedule. This schedule will clarify when and how PPRP participation is required for document review, attending meetings, delivering written responses, and other key project activities. Specific Comments PPRP Comment #1: "We assume that all of the Action Items will be addressed by the Tl Team during the finalization of the HID and the associated Seismic Source Characterization report preparation and documentation." Response to PPRP Comment #1: The Tl team records action items and key issues identified at each project workshop. During finalization of the SSC model and report, the Tl team will address the action items identified at Workshop #3 and previous project workshops. Page 1of4 Response to observations and comments from the PPRP on Workshop #3 -May 14, 2014 PPRP Comment #2: "The PPRP suggests that a written plan be prepared and implemented as soon as possible for identifying {1) the relevant geodetic data set(s) to be considered and {2) how the geodetic data contribute to characterizing seismic hazard." Response to PPRP Comment #2: Based on the evaluation of data presented in the published scientific literature and at Workshops #1 and #2, the Tl team excluded from the Preliminary SSC model the use geodetic data in calculating rates and identifying seismic sources. The basis for this decision will be further evaluated and documented in detail in the SSC report. PPRP Comment #3: "Preparation of a succinct narrative and more complete documentation of the analytical tools, called "smoothing" during the meeting, should be considered so that reviews of the analyses can be carried out in an informed and efficient manner." Response to PPRP Comment #3: The Tl team acknowledges the hazard significance of the decision to calculate earthquake recurrence parameters for areal source zones using a smoothed seismicity approach. The Tl team also understands that the soothing approach used in the project is a complex procedure that may not be well understood by all readers of the SSC report. For these reasons, a complete and thorough documentation of the smoothing process and assumptions will be provided in the SSC report. PPRP Comment #4: "Conducting a review of the earthquakes comprising these events should be considered to determine if they are located on land or are associated with faulting within the Gulf If they are pre-instrumental (or otherwise poorly located), efforts could be made to reposition the events." Response to PPRP Comment #4: The Tl Team reviewed the portion of the project earthquake catalog directly east of the Gulf of California, where an approximately triangular wedge of seismicity appears to taper off into the Southern Basin and Range. In order to assess the likelihood that: (1) the project catalog correctly reflects a region of elevated seismicity rate along the western border of the Southern Basin and Range; and (2) the catalog correctly locates Mw > 4.65 earthquakes in this region, the Tl Team reviewed the age, location uncertainty, and magnitude type of these earthquakes. Approximately 62 earthquakes in the project catalog are identified in this area. The majority of these earthquakes occurred recently, such that only eight earthquakes occurred prior to 1950. Furthermore, the majority of these earthquakes are based on instrumental data, such that only two earthquakes are reported with intensity-based (MMI) magnitudes. From these observations, the Tl Team assumes that the project catalog correctly reflects a region of elevated seismicity along the western border of the Southern Basin and Range. Most of the earthquakes in the project catalog for this area are minor to moderate in magnitude. Of the 62 earthquakes in the area, only six have magnitudes Mw > 4.65 (i.e., 1935 Mw 5.0, 1952 Mw 5.1, 1958 Mw 4.9, 1963 Mw 4. 7, 1969 Mw 4.8, and 1981Mw4.9). The location and magnitude for the 1935 earthquake are based on felt intensity reports and therefore may be highly uncertain. The locations and magnitudes of the 1952 and 1958 earthquakes are based on instrumental data but are reported only to the nearest half-degree, reflecting a high degree of uncertainty. The Tl team assumes that the more recent 1963, 1969, and 1981 earthquakes are relatively well located, however, and should not be repositioned. Given this assumption, it is difficult for the Tl team to justify repositioning the 1935, 1952, and 1958 earthquakes. Therefore, the Tl team does not plan to reposition any of the earthquakes in this area. Page 2 of 4 Response to observations and comments from the PPRP on Workshop #3 -May 14, 2014 PPRP Comment #5: "The nature of the observed surface displacements on the Sand Tonk fault should be considered to assess the observations in terms of overage and/or maximum fault displacement values." Response to PPRP Comment #5: The Tl team appreciates the discussions with the PPRP regarding observations of the Sand Tank fault scarp height and characterization of the Sand Tank fault source. Demsey and Pearthree (1990) recognize that the zone of deformation for normal faults commonly extends beyond the immediate location of the scarp and, therefore, their estimate of an approximately 2-m-high scarp for the Sand Tank fault is based on fault-normal topographic profiles that were surveyed over distances of approximately 700 m. In the Preliminary SSC model, greater weight is given to the possibility that this scarp height represents average slip in the most-recent earthquake, as opposed to maximum slip. The Tl team will re-evaluate this modeling decision and determine whether greater weight should be assigned to the possibility that the observed scarp height represents maximum coseismic displacement. PPRP Comment #6: "The two-zone model for areal seismic sources may be unrealistic based on the level of geologic data that are available, and thus its usefulness should be reconsidered. This would result in a new 6-zone model that would be either the only model or the dominantly weighted model. 11 Response to PPRP Comment #6: The Tl Team appreciates discussions with the PPRP regarding areal seismic sources. The Preliminary SSC model includes a seven-zone model alternative and a two-zone model alternative. The seven-zone model incorporates a broad range of geologic data to define unique seismotectonic domains that capture differences in expected future rupture characteristics. The zone model simply distinguishes the highly active plate boundary of California and Baja California from the less active areas to the east. The Tl team generally agrees that the geologic data suggest the zone model may be unrealistic, but this alternative is included to capture the range of technically defensible interpretations. Going forward, the Tl team will further evaluate the need for the two-zone alternative. The Tl team agrees that the Eastern Transverse Ranges (ETR) zone is unnecessary, based on discussions with the PPRP and on hazard sensitivity results presented at Workshop #3. The Tl team likely will combine the ETR zone into the adjacent Southern California and Baja (SCABA) source zone. PPRP Comment #7: "As part of the detailed Quaternary mapping fault studies for the site vicinity, the potential for Quaternary active faults located within the modern alluvial drainages should be considered." Response to PPRP Comment #7: Quaternary geologic mapping of the site vicinity is ongoing, but LCI expects to deliver in the near future its mapping report to the Tl team for evaluation. Given the expected distribution and ages of Quaternary deposits across the site vicinity, the Tl team agrees that it may not be possible to preclude the presence of active faults throughout the entire vicinity, especially beneath major river channels and adjacent Holocene deposits. As part of the integration of the mapping data into the SSC model, the Tl team will be mindful of these data limitations. Closure We appreciate the comments from the PPRP on Workshop #3 and suggestions for improvement to the ongoing Palo Verde Seismic Hazard Evaluation Project. We are incorporating your observations, suggestions, and recommendations into our program to the extent possible. We look forward to seeing Page 3 of 4 Response to observations and comments from the PPRP on Workshop #3 -May 14, 2014 you again at Workshop #4 ("Final Briefing") and to sharing with you our additional progress on the project at that time. Sincerely, I f)jj . William Lettis .::::::.*:--1L---* r:.;:.. /. ,// e:-: '---.t t:'. ' Scott Lindvall / PTI SSC Tl Team Lead J ) \'). \ \ t v* \ \ Ross Hartleb LCI Project Manager Page 4 of 4 February 26, 2015 Dr. Ross Hartleb LCI Project Manager, Palo Verde Nuclear Generating Station (PVNGS) Seismic Hazard Evaluation Project Lettis Consultants International, Inc. 27441 Tourney Road, Suite 220 Valencia, CA 91355

Subject:

PVNGS SSHAC Level 3 Seismic Source Characterization

Dear Dr. Hartleb:

On March 12, 2012, the U.S. Nuclear Regulatory Commission (NRC) issued a request for information pursuant to 10CFR50.54(f), requiring that all operating nuclear plants in the U.S. perform a site-specific Probabilistic Seismic Hazard Analysis (PSHA) and develop a Ground Motion Response Spectrum (GMRS) in accordance with Regulatory Guide 1.208 for comparison to the plant license Safe Shutdown Earthquake (SSE) ground motion. Licensees are required to evaluate the seismic hazard using present-day NRC regulatory criteria and guidance. For plants in the western U.S., including the PVNGS, the directive requires that the site-specific PSHA be performed using the Senior Seismic Hazard Analysis Committee (SSHAC1, 2) Level 3 process to develop the Seismic Source Characterization (SSC) model. In accordance with the requirements for a SSHAC Level 3 study, the PVNGS SSC Participatory Peer Review Panel ("PPRP") is pleased to issue this PPRP Closure Letter containing our findings with respect to the PVNGS SSC Project. The PPRP was actively engaged in the review of all phases and activities of the Project's implementation. These phases included development of the Project Plan, planning and execution of the Technical Integration (TI) Team's evaluation and integration activities, and review of the TI Team's documentation of the SSC model. These phases are at the core of the SSHAC process. In accordance with NRC guidance for SSHAC projects, the role of the PPRP is to conduct a review of both the process followed and the technical assessments made by the TI Team. Accordingly, this letter documents the activities that the PPRP has carried out to perform its review of the adequacy of the process followed, and its findings regarding the technical adequacy of the SSC. 1 Budnitz, R.J., G. Apostolakis, D.M. Boore, L.S. Cluff, K.L. Coppersmith, C.A. Cornell, and P.A. Morris (1997). Recommendations for Probabilistic Seismic Hazard Analysis: Guidance on Uncertainty and the Use of Experts [known as the "Senior Seismic Hazard Analysis Committee Report': or "SSHAC Guideline'], NUREG/CR-6372, U.S. Nuclear Regulatory Commission, TIC; 235076, Washington. D.C. 2 USN RC (2012). Practical Implementation Guidelines for SSHAC level 3 and 4 Hazard Studies, NUREG-2117, U.S. Nuclear Regulatory Commission, Washington, D.C. PVNGS SSC PPRP Closure Letter PPRP Activities for the SSC Peer Review The fundamental idea of a participatory peer review process entails the continual review of a project from its start to its completion. Thus, proper participatory peer review requires adequate opportunities during the conduct of the project for the PPRP to understand the data being used, the analyses performed, the TI Team's evaluations and integration of the technical bases for its assessments, and the completeness and clarity of the documentation. Participatory peer review also involves occasions for the PPRP to provide its reviews and comments in written form during the conduct of the project, such that their observations and recommendations can be considered by the TI Team in a timely manner prior to the completion of the project. Written comments by the PPRP serve to document the review process and provide part of the formal record documenting that all aspects of the SSHAC process have been satisfactorily conducted. The activities of the PPRP for the PVNGS SSC are summarized in the table below, which includes written reviews during the various stages of the project. These activities directly addressed the conduct of the PVNGS SSC and the development of the SSC Report. I Date PPRP Activity January 21. 2013 SSC Kickoff Meeting ("Workshop O"); PPRP members attended in person as observers I January 23, 2013 PPRP submitted review comments on the Project Plan via email I April 9-11, 2013 SSC Workshop No. 1: Significant Issues and Data Needs; PPRP members attended in person as observers April 24, 2013 PPRP submitted written review comments on Kick-off Meeting June 5, 2013 PPRP submitted written review comments on Workshop 1 July 10, 2013 TI working meeting No. 4: PPRP members Savage and Machette attend portion of TI working meeting by phone as observers August 27-28, 2013 TI working meeting No. 5: PPRP member Rockwell attends portion of TI working meeting by phone as observer September 24-26, 2013 SSC Workshop No. 2: Alternative Interpretations; PPRP members attended in person as observers October 23, 2013 PPRP submitted written review comments on Workshop No. 2 February 4-6, 2014 Field Review of Geologic Mapping: PPRP members attended in person as observers March 24, 2014 PPRP submitted written review comments of Field Review of Geologic Mapping April 23-25, 2014 SSC Workshop No. 3: Preliminary Model and Hazard Feedback: PPRP members attended in person as active participants PVNGS SSC PPRP Closure Letter 2 I Date PPRP Activity I May 5, 2014 PPRP submitted written review comments on Workshop 3 I June 18, 2014 Update on SSC Activities: PPRP members attended via webinar as observers I July 10-11, 2014 SSC Final Briefing; PPRP members attended in person August 1, 2014 Update on SSC Activities; PPRP representatives attended via webinar as observers I January 12, 2015 Submittal of review comments on SSC Report, transmittal 1 &2 I January 17, 2015 Submittal of review comments on SSC Report, transmittal 3 January 19-22, 2015 Submittal of PPRP written review comments on SSC Report transmittals 1-3 and on Tl Team's responses to PPRP written review comments February 17-19, 2015 Submittal of PPRP written review comments on PVNGS SSC Draft Report transmittal 4 and on Tl Team's responses to PPRP written review comments February 19-25, 2015 Teleconference call to resolve remaining issues with SSC Draft Report (2/19) and review of Tl Team's responses to teleconference call issues I February 26, 2015 Submittal of PVNGS SSC PPRP Closure Letter The activities listed above are those that directly addressed the conduct of the PVNGS SSC and the development of the PVNGS SSC Report. The PPRP has concluded that its ongoing review and feedback interactions with the TI Team during the conduct of the PVNGS SSC Project activities fully met the expectations for a SSHAC Level 3 study. From the presentation of the plans for conducting the PVNGS SSC at the start of the project to the completion of the PVNGS SSC Report, the TI Team provided multiple and effective communications with the PPRP. Webinars and written communications allowed the PPRP to fully understand the technical support for the Tl Team's assessments. The TI Team provided written responses to PPRP comments documenting that all comments had been adequately considered during the conduct of the work and the compilation of its documentation. SSHAC Technical Review The role of the PPRP in the review of the technical aspects of the project is specified in NUREG-2117 (USNRC, 2012) as follows: "The PPRP fulfills two parallel roles, the first being technical review. This means that the PPRP is charged with ensuring that the full range of data, models, and methods have been duly considered in the assessment and also that all technical decisions are adequately justified and documented. PVNGS SSC PPRP Closure Letter 3 The responsibility of the PPRP is to provide clear and timely feedback to the TI/TFI and project manager to ensure that any technical or process deficiencies are identified at the earliest possible stage so that they can be corrected. More commonly, the PPRP provides its perspectives and advice regarding the manner in which ongoing activities can be improved or carried out more effectively. In terms of technical review, a key responsibility of the PPRP is to highlight any data, models or proponents that have not been considered. Beyond completeness, it is not the responsibility of the PPRP to judge the weighting of the logic trees in detail, but rather to judge the justification provided for the models included or excluded, and for the weights applied to the logic-tree branches." Consistent with this USN RC guidance, the PPRP reviewed at multiple times during the project the TI Team's analyses and evaluations of data, models, and methods. These reviews included conference calls, post-workshop meetings, written comments, and the review of drafts of the SSC Report. Through these reviews, the PPRP communicated feedback to the TI Team regarding data and approaches that did not appear to have been considered, suggestions for methods being used within the technical community, and recommendations for ways that the documentation could be improved to include more discussion of the technical bases for the assessments. Examples of PPRP feedback regarding technical aspects of the project can be found in the written comments provided following workshops and field trips and during the review of the draft final report. The Tl Team was responsive to the questions, comments, and suggestions made by the PPRP relative to the technical aspects of the project. Therefore, the PPRP concludes that the technical aspects of the project have been adequately addressed. SSHAC Process Review As explained in NUREG-2117 (USNRC, 2012), the SSHAC process consists of two important activities, described as follows: "The fundamental goal of a SSH AC process is to carry out properly and document completely the activities of evaluation and integration, defined as:

• Evaluation: The consideration of the complete set of data, models, and methods proposed by the larger technical community that are relevant to the hazard analysis.
• Integration: Representing the center, body, and range of technically defensible interpretations in light of the evaluation process (i.e., informed by the assessment of existing data, models, and methods)." These activities are essential to any SSHAC Level study and to both new models and refinements to existing models (such as the PVNGS SSC). During the Evaluation phase of the PVNGS SSC, the TI Team considered new data, models, and methods that have become available in the technical community since the previous PVNGS PSHA PVNGS SSC PPRP Closure Letter 4 projects were completed in 1993 and 2012. In particular, the TI Team incorporated new earthquake occurrence models and carried out additional geologic mapping. The PPRP concluded that the Tl Team conducted a satisfactory evaluation process and that this process has been sufficiently documented in the SSC report. During the Integration phase of the project, an updated SSC model was developed for purposes of the PVNGS PSHA. SSHAC guidelines require that the technical bases for the SSC model be documented thoroughly in the SSC report. The SSC document demonstrates the consideration by the TI Team of the existence of seismic-source data and models that have become available since the previous PVNGS SSC model was developed. During the entire course of the PVNGS Project, The TI Team maintained close coordination with the SWUS ground-motion characterization project to assure that the PVNGS SSC will connect seamlessly with the GMC model. Based on the review of the Evaluation and Integration activities conducted by the TI Team, as well as the documentation of these activities in the SSC report, the PPRP concludes that the SSHAC level 3 process has been adequately conducted. Conclusion Based on its review of the PVNGS SSC, the PPRP concludes that the process and technical aspects of the analysis fully meet accepted guidance and current expectations for a SSHAC Level 3 study. We appreciate the opportunity to provide our review of the project. Sincerely, PVNGS SSC PPRP Members William U. Savage, Chair Michael N. Machette Thomas K. Rockwell . J' J1 /1 < .:*:,1:i **' .. // ,/ .. PVNGS SSC PPRP Closure Letter 5 ATTACHMENT 3 Participatory Peer Review Panel (PPRP) Comments on the Draft Seismic Source Characterization (SSC) Report and Technical Integrator (Tl) Team Responses Senior Seismic Hazard Analysis Committee (SSHAC) Level 3 SSC Palo Verde Nuclear Generating Station (PVNGS) This attachment contains technical comments made by the PPRP on various drafts of the PVNGS SSC Report, and provides a record of the Tl Team response to each comment. PPRP comments are listed by date received and draft report location (section number and page number). Please note that as text was added and deleted during the revision process, draft report locations of PPRP comments (primarily page numbers) are not necessarily the same as their locations in the final report. April 17, 2015 PVNGS SSC Additional Documentation Attachment 3, Page 1of53 Date Location in No. Received Report1 1 1/13/2015 Section 1. 1 , Page 1-2 2 1/13/2015 Section 1.1.3. Page 1-3 3 1/13/2015 Section 1.2, Page 1-4 4 1/13/2015 Section 1.3, Page 1-4 5 1/13/2015 Section 1.3, Page 1-5 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT PPRP COMMENTS AND Tl TEAM RESPONSES Location of PPRP Comment Comment Revision Chapter 1 Please clarify the new data, methods, and Throughout models since the 1993 study to complement report the 2013 UCERF3 example. It appears that the product of this SSC study will be a replacement for the current SSC model; if it is, please so state. The roles of McGuire and Walling need to be (Same) described. These two sentences effectively define the (Same) common terminology of being "hazard informed"; if desired, this terminology could be defined here because it is used later in the report text (e.g., Section 3.2.9) as a reminder of the usefulness of the hazard sensitivity analyses. Comment A: The logic for the order of the (Same) numbered work products is not clear. Please consider an order that reflects the logical sequence of the work, such as Project Plan, Workshop Summaries, Earthquake Catalog. SSC Model, Hazard Input Document, Reference Evaluation Table, and Database; or use the Table of Contents and Appendix order. Comment B: Please explain which products are not provided in this report and why. Has the PPRP reviewed these Workshop (Same) Summaries in any form yet? Will the PPRP letters on the Workshops be included in the 1 PPRP comment locations refer to draft versions of the SSHAC report. April 17, 2015 PVNGS SSC Additional Documentation Summary of Revisions to Report Text revised as suggested. See also comment #6 and comment #7 for further discussion of this issue. In regard to "replacement" vs. "update", yes, this should be described as an updated SSC model. Report text revised throughout. Text revised to add description of the roles of McGuire and Walling. Text added to summarize the approach as being "hazard informed" and to define that term as it is used throughout report. The ordering of these items is revised as suggested. Report text revised. PPRP correspondence appendix (originally Appendix B) will not be included in the final report, consistent with the Attachment 3, Page 2 of 53 Date Location in No. Received Report1 6 2/17/2015 Section 1. 1 , Page 1-2 7 2/17/2015 Section 1 . 1 , Page 1-2 8 1/13/2015 Section 2.2, Page 2.2 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision summaries? Will the Workshop Summaries be more like a summary of the topics covered, names of the presenters, and copies of presentations? We are concerned about a technical document being prepared that does not have PPRP review. Upon rereading this sentence and the non-(Same) response to Michael's previous comment, the "level" of update is not clearly described. The "new data, methods, and models" are not described, and are not evaluated with respect to the hazard significance. Instead, this discussion should focus on the level of update required by the NRC. What is the date of the current licensing basis? The update should(?) probably be from that date to the present. regardless of the 1993 and 2012 SSC studies. This matter should be clearly discussed. Following up on Michael's comment, the reader (Same) would have a better sense of what areas of data, methods, and models are going to be incorporated in the SSC study if there was a short discussion of key new data and models that will be incorporated in this SSC study. Chapter 2 Is this discussion needed, as level 3 is NIA proscribed for this project? The existence of other levels is irrelevant to the PV project. The discussion of the SSHAC methodology should focus on Level 3, which was specified by the PVNGS SSC Additional Documentation Summary of Revisions to Report Diablo and Hanford reports. The PPRP closure letter will be included as part of the preface material. Workshop Summaries appendix includes only workshop presentations and agendas, which have been reviewed by the PPRP. This appendix does not includes "workshop summaries" per se. Revisions were made to the paragraph to provide an example of new data, model, and method. Very brief descriptions are provided, with details presented in subsequent chapters. Palo Verde's operating license was extended in 2011 for an additional 20 yrs, allowing for operations through 2047. Little new seismic information was provided as part of the extension process, which relied heavily on data developed during the original licensing process. As described in Sect 1.1.1. the current work is required as part of post-Fukushima directives from NRC. which specify the need for SSHAC3 for the current screening of WUS plants. Paragraph revised to provide example of new data, model. and method available since REI (1993). Discussion is minimal. as details are presented in subsequent chapters. This very brief discussion is intended to provide context for the selection of SSHAC levels. No change to text. Attachment 3, Page 3 of 53 Date Location in No. Received Report1 9 1/13/2015 Section 2.3.9, Page 2-7 10 1/13/2015 Section 2.4, Page 2-7 and 2-8 11 2/17/2015 Section 2.3.3, Page 2-4 12 2/17/2015 Section 2.3.3. Page 2-5 13 2/17/2015 Section 2.4, Page 2-7 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision NRC as noted in Section 2.0. This report should not be a SSHAC training document, but should explain how the SSHAC process has been carried out for this project, and at the SSHAC3 level. Should the "database" be described as a (Same) geographic or geospatial database containing geographic or spatial information? Regarding released versus published: Reports (Same) such as the LCI ones are gray literature and best termed released (i.e. made available), not published in the normal sense of a peer-reviewed professional journal article or state-federal publication. The nature of independent technical review of the released reports and maps should be stated. This sentence represents the second part of (Same) the two-step SSHAC process. As such it should be in a paragraph by itself. Could you add more explanation of the integration process to make the new paragraph more parallel with the discussion of evaluation? Please explain this role more clearly so there (Same) isn't a one-paragraph sentence. and remind the reader of the working time between Workshops when the Hazard Analysts input was obtained and used. Is this considered to be an independent {Same) technical review? In general. what was the independent peer review process for the new data collection? This was asked for in a previous PPRP comment. PVNGS SSC Additional Documentation Summary of Revisions to Report Text revised to refer to "spatial database." Text revised as suggested. More detail added to discussion of integration process. Additional sentence added. No, the PPRP's review of the Site Area and Site Vicinity maps should not be considered an independent technical review. No truly independent (3'd party) review of these maps occurred. Consistent with the SSHAC process, the Tl Team and PPRP communicated frequently about the plan for data collection, as well as the Attachment 3, Page 4 of 53 Date Location in No. Received Report1 14 1/13/2015 Section 3. 1 , Page 3-1 15 1/13/2015 Section 3.1.1, Page 3-1 16 1/13/2015 Section 3. 1 . 1, Page 3-2 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision Chapter 3 It would be appropriate to state that the PPRP Section reviewed the Project Plan; here are the details 3.2.1, Page for your consideration: The PPRP was 3-3, 151 provided with a copy of the Project Plan dated paragraph January 17, 2013, in advance of the Kickoff Meeting (Workshop 0) that was held on January 21, 2013. Although there was no discussion of PPRP comments during the Kickoff Meeting, the PPRP provided detailed written comments on the January 17, 2013 version of the Project Plan on January 21, 2013. We received a revised version of the Project Plan on February 19, 2013, and felt that our comments were satisfactorily addressed and that the Plan was made clearer and thus was more effective for its intended use. We suggest that this review process be mentioned in Section 3.1. The "collection of new data as needed" should (Same) be described as an evaluation process that involves identifying how possible new data could impact the overall evaluation; i.e., the "need should be clearly driven by the evaluation process in terms of possible impact on the SSC model. "Logic Tree" is an important element in the (Same) SSC model and should be described in a sentence, in a reference to somewhere else in the report, and augmented by a clear glossary entry. Please consistently refer to this element PVNGS SSC Additional Documentation Summary of Revisions to Report final results. Text changed from "reviewed by" to "presented to" the PPRP. Details of PPRP review and revision of Project Plan added. Text revised as suggested. Definition for logic tree provided. The phrase "logic tree model" has been removed from the report text. Attachment 3, Page 5 of 53 Date Location in No. Received Report1 17 1/13/2015 Section 3.2.2, Page 3-3 18 1/13/2015 Section 3.2.8, Page 3-6 19 1/13/2015 Section 3.2.8. Page 3-8; Figure 3-1 20 2/17/2015 Section 3. 1 . 1, Page 3-1 21 2/17/2015 Section 3.1.2. Page 3-2 22 2/17/2015 Section 3.1.1, Page 3-1 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision either as a "logic tree" or a "logic tree model", but not both. The scope of the REs {and PEs) was much Section broader than significant parameters and 3.1.1, Page features and should include issues of new 3-1, Item 4 data, new models, and proponent views. It seems that the PPRP has not seen this Chapter 3 summary; procedurally, we should review it and provide written comments similar to what we did for the previous workshops. This figure is not cited in the report. Is this Figure 3-1 NU REG figure needed? It does not specifically represent the SSHAC Level 3 process, nor does it include Workshop 0 and the Final Briefing that were part of the PV project. If you want a figure, it should accurately represent the PV Project. This would read more clearly if written: "The {Same) PPRP was involved in the evaluation process through attendance at workshops, review of project interim documentation. and attendance at selected working meetings." This sentence would read more clearly written Section as:" ... integration process through attendance 3.1.3 at workshops, review of interim project documentation, and attendance at selected working meetings." This sentence is also redundant with that on the preceding page. and in the next section -please consider consolidation. Seems like logic tree should be introduced first, {Same) then sensitivity analysis of the tree follows. PVNGS SSC Additional Documentation Summary of Revisions to Report Text revised as suggested. Text revised throughout Chapter 3 to indicate that the workshop "summaries" received by the PPRP included workshop agendas and presentations, as opposed to formal notes or minutes. Figure 3-1 is cited twice on the first page of Chapter 3. This figure represents the elements of the SSHAC process, and is not PVNGS-specific. Text revised as suggested. Agree. Section 3.1.3 simplified to reduce redundancy. We removed discussion of logic tree from this section. Really logic trees are built and revised after evaluating data. Evaluation phase now Attachment 3, Page 6 of 53 Date Location in No. Received Report1 23 2/17/2015 Section 3.2.10, Page 3-7 24 1/13/2015 Section 4.1, Page 4-1 25 1/13/2015 Section 4.1.1, Page 4-1 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision The previous response about the PPRP's {Same) review of workshop summaries is not satisfactory. The term "summary" is not equivalent to "Workshop agenda and copies of presentations." Please make this change for the sake of clarity. Chapter4 The orogenies resulted from subduction of {Same) buoyant crust, resulting in the flattening of the subducting slab and back-arc shortening. In turn, this shut off Sierran volcanism. with eastward migration and then cessation of subduction-related volcanism. The subduction was occurring well before these orogenic phases occurred. Please consider clarifying and correcting this aspect. Regarding the term "thin-skinned," this has {Same) always been a poor term, as it implied no involvement of basement rock in its original usage. All "thin-skinned structures must root into basement, as one cannot shorten the sedimentary cover without shortening the rock beneath. Others use it simply refer to the style of crustal shortening -ramp and flat crumpling in thick sedimentary settings, as opposed to Laramide or Pampean style, basement-cored uplifts that occur where sedimentary cover is thin or already consumed by "thin-skinned" shortening. If you use this term, please define and describe exactly what you mean, as this is PVNGS SSC Additional Documentation Summary of Revisions to Report described as evaluating data. and evaluation of hazard significance of various aspects of the base case model. Text revised to clarify agenda and workshop slides were provided as opposed to a workshop summary. Text added clarifying that orogenesis occurred subsequent to subduction. Sentence deleted, paragraph rewritten to simply describe the fact that thrusts are low-angle structures. Attachment 3, Page 7 of 53 Date Location in No. Received Report1 26 1/13/2015 Section 4.1.1. Page 4-1 27 1/13/2015 Section 4.1.1, Page 4-1 28 1/13/2015 Section 4.1.2, Page 4-2 29 1/13/2015 Section 4.1.2, Page 4-2 30 1/13/2015 Section 4.1.2. Page 4-2 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision a controversial term to some researchers. Attributed to. or a consequence of? Flattening (Same) is a result of subduction of buoyant crust. Arc volcanism is generated at subduction depths of +110 km. As the slab flattens, arc volcanism ceases. or in this case, migrated east to where the subducting slab reached the necessary depth for melting. Please consider adding this discussion. Baja California and Sonora Mexico are not Figure 4-1 shown on the first map, Figure 4.1, which should be extended southward to at least include all the site region. The northern Basin and Range (tectonic {Same) province) should be indicated on Figure 4.1 or Figure 4-1 some other suitable map. There should be a clear definition of Basin and Range as a tectonic province, vis-a-vis the Great Basin as a physiographic region. The Wasatch is not the western margin of the (Same) Great Basin, nor is the central Nevada seismic belt the eastern margin. The western margin is the Sierra Nevada frontal fault zone, whereas the eastern margin is the Wasatch frontal fault zone. Please correct. Please check the accuracy of your statement that the margins accommodate more than half of the extension, once the margins are corrected. This statement doesn't follow with your earlier NIA statement that more than half of the extension PVNGS SSC Additional Documentation Summary of Revisions to Report Connection between trends in magmatism and migrating contact between subducting slab and asthenosphere added. Figure 4-1 has been revised to address this. Text has been revised so that geodetic and geologic transects refer to specific locations within the northern Basin and Range. All subsequent references to the Great Basin are also removed. Figure 4-1 revised to show boundaries of the northern and southern Basin and Ranoe. Specific reference points for these measurements added. More than half of 3 mm/yr (so more than 1.5 mm/yr) is found to be localized to the margins of Attachment 3, Page 8 of 53 Date Location in No. Received Report1 31 1/13/2015 Section 4.1.2, Page 4-2 32 1/13/2015 Section 4.1.3, Page 4-3 33 1/13/2015 Section 4.2, Page 4-3 34 1/13/2015 Section 4.2.1, Page 4-3 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision is accommodated on the margins. Please explain. Please identify what areas are covered by the (Same) Sonoran Desert and how they relate to the southern Great Basin. Most researchers now believe the "proto-Gulf' (Same) was simply earlier southern San Andreas fault transtension. The southern SAF was close to its modern configuration, albeit at a slower rate, by 12 Ma. The San Gabriel fault was active during this phase, resulting in Ridge Basin. So was the Naciemento (and possibly Rinconada) and many other faults of the early SAF system. The Gulf opened prior to 5 Ma -there is much literature on this topic that post-dates Lonsdale, 1989. Should "north" at the end of the sentence be {Same) northwest? Or are you referring to the absolute plate motion. in which case you are referring to relative motion between the Pacific and North American plates. Please clarifv this statement. Are the discontinuous northwest-to northeast-{Same) trending mountain ranges consistent with the Section earlier statement about structural trends being 4.1.2, Page NNE to ENE? 4-2, 4th paragraph PVNGS SSC Additional Documentation Summary of Revisions to Report the region, according to geodetic data. Therefore, less than 1.5 mm/yr is available for the interior of the region. Koehler and Wesnousky find that the long-term extension rate across all faults in the interior of this region is approximately 1 mm/yr, matching the geodetic constraint for the interior. No chanQe to text. In this sentence, Sonoran Desert was simply used as a way to describe southeastern Arizona, or the general location of the PVNGS site. To avoid confusion, text has been edited to indicate that southeastern Arizona hosts less than half of the strain calculated along this transect. Lonsdale cited in regard to the linked system of basins and transforms. Timing of Gulf opening comes from Oskin et al. (2001) and Oskin and Stock (2003), which have been added (text has also been revised to indicate localization at 6 Ma rather than 5 Ma). Also, text has been revised to clarify that we are referring to opening of the northern Gulf of California. Corrected sentence to read "northwest", since we are describing the relative plate motion vector. Earlier statements described NW-striking detachment faulting occurring from 30-15 Ma, as well as (now clarified) N-to ENE-striking block faulting occurring from 15 Ma. So, section 4.2.1, Page 4-3, 2nd paragraph should be Attachment 3, Page 9 of 53 Date Location in No. Received Report1 35 1/13/2015 Section 4.2.1, Page 4-3 36 1/13/2015 Section 4.2.1, Paqe 4-4 37 1/13/2015 Section 4.2.1, Page 4-4 38 1/13/2015 Section 4.2.3, Paqe 4-6 39 1/13/2015 Section 4.2.5, Page 4-7 40 1/13/2015 Section 4.2.5, Page 4-7 41 1/13/2015 Section 4.2.5. Page 4-7 42 1/13/2015 Section 4.2.5, April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision How can extension be more complete? Is it {Same) ever complete? Do you mean a greater magnitude of extension? Does more complete imply that extension is done? Please clarify. Please give quantitative examples of what you {Same) consider to be slow and lonq. The kinematics of the Sand Tank fault are {Same) assumed, as there are no direct kinematic data. Perhaps it is better to state that the Sand Tank fault is assumed to be a normal fault. Is this the same as saying that the known faults {Same) do not exhibit seismicitv? Please elaborate. Is there not continued development of the {Same) Salton Trough in the modern tectonic environment? Please clarify. Please revise as follows. At the workshop, {Same) Rockwell argued for a higher rate based on new paleoseismic data that demonstrated more frequent earthquakes via a longer record. The Thomas and Rockwell record is too short, encompassing only 2 events (one cycle). Is this still part of the Colorado Desert {Same) Province? Please clarify. Is this true? Or are earthquake locations poor? {Same) PVNGS SSC Additional Documentation Summary of Revisions to Report describing this range of azimuths. Corrected to now describe NW-to ENE-trending mountain ranaes. Yes, poor phrasing. Text has been edited to more clearly state that the SBR physiographic reflects extension that has largely ceased. whereas NBR physiography reflects ongoing extension. Included specific numbers from the referenced paper (Pearthree et al., 1983 added). Text revised as suggested. Text revised to clarify that seismicity is diffuse and does not form aliqnments. Replaced "formed" with "initiated. Text deleted. Clarified. The title of this subsection has been edited to simply ready "Colorado Desert Province". and the introduction states that this province extends into the northern Gulf of California. When discussing characteristics of the northern gulf. the text now make it clear that this is one portion of the greater physiographic province. Text revised here and in earlier instances in 4.2.5 Attachment 3, Page 10 of 53 Date Location in No. Received Report1 Page 4-8 43 1/13/2015 Section 4.2.6, Page 4-8 44 1/13/2015 Section 4.2.6, Page 4-8 45 1/13/2015 Section 4.2.6, Page 4-8 46 1/13/2015 Section 4.2.6, Page 4-8 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision Most seismicity should be associated with transform structures and spreading ridges. The rocks were produced in the Mesozoic, but (Same) the Peninsular Ranges themselves are young and a result of rift-shoulder uplift. See Mueller et al., 2009. There is no evidence of topographic relief prior to the middle Miocene, and most uplift may be Pliocene and younger. Should the San Jacinto Mountains be the (Same) Santa Rosa Mountains? Fialko argues for close to 20 mm/yr, but that (Same) includes strain from the Elsinore fault as well. Hudnut and Sieh (1989) suggest 3-6 mm/yr for the Superstition Hills fault. Gurrola and Rockwell (1996) suggest 5-9 mm/yr for the Superstition Mtn fault. Together, a rate of 8-15 mm/yr is consistent with Blisniuk's rate at Anza. as well as Fialko's rate (which includes both Elsinore slip and the deformation associated with NE-striking cross faults. Please fix this. The 1-2 mm/yr slip rate is for the southernmost NIA end of the fault in the Coyote Mtns. The rate increases in the Coyote Mtns to 2 mm/yr only 2-3 km NW from the Fletcher et al. locality (Masana et al., 2012, 2013). The rest of the PVNGS SSC Additional Documentation Summary of Revisions to Report to specify that patterns of faulting and seismicity are less well defined in the northern Gulf of California. For this specific portion of the Colorado Desert Province (the Gulf, north of Isla Angel de la Guarda), Persaud et al. (2003) argue that deformation is distributed across many faults related to the Delfin basin, Consag basin, and Wagner basin. They argue that there is no primary structure defining this portion of the Gulf, and that is reflected in the seismicitv. Yes, timing of the uplift was conflated with age of magmatism. Corrected timing, citing Mueller et al. (2009). Yes, changed to Santa Rosa Mountains. Yes, clear mistake. The intent was to describe the UCERF3 best estimates along the entire fault system, which would be Blisniuk et al. (2013) from the Clark/Coyote Creek overlap to the north, and the sum of the UCERF3 best estimate slip rates for Superstition Mtn and Superstition Hills to the south. These latter slip rates are 7 mm/yr and 4 mm/yr (respectively), summing to 11 mm/yr. The goal of this paragraph is simply to provide a brief, simplified picture of one of the major faults within the Peninsular Ranges province. No change to text. Attachment 3, Page 11 of 53 Date Location in No. Received Report1 47 1/13/2015 Section 4.2.6, Page 4-8 48 1/13/2015 Section 4.2.6, Page 4-8 49 1/13/2015 Figure 4-1 50 1/13/2015 Figure 4-8 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision Elsinore slip rate is transferred to the Earthquake Valley fault via the Palomar Mountain stepover, and then to the southern San Jacinto fault via the Vallecito-Fish Creek Mountain stepover (Rockwell et al., 2013) at a rate of 2.5 mm/yr. Magistrale and Rockwell (1996) referred to this as the eastern strand of the Elsinore fault. Please consider that Fialko (2006) drew his (Same) interpretation because at least half of the Elsinore slip rate had been added to the southern San Jacinto fault rate at the latitude of Fialko's study. The 1910 earthquake produced 25 cm of RL (Same) slip on a circa 1890's concrete flume -see Rockwell et al., 2014 in press. Also, the Laguna Salada and Borrego faults are SE continuations of the Elsinore fault zone and produced the 1892 M7.2 Laguna Salada earthquake and the 2010 M7.3 El Mayor earthquake. Please revise this statement. The map should be extended to the south to (Same) include the entire 400-km-radius study region. The star should be labeled as the PVNGS site. The second paragraph of Section 4.1.1 refers to Baja California and Sonora, Mexico; these locations should be labeled in the expanded area of Fiqure 4-2. Please indicate the magnitude range of the (Same) Lockridge et al. data shown. Why state that the ANSS seismicity shown includes statistically dependent and independent events? If all of the ANSS data within the date and magnitude limits are included, there is no need to point out PVNGS SSC Additional Documentation Summary of Revisions to Report This part of the sentence has been deleted. Text revised to incorporate these points. New figure created to address these issues. Figure revised as suggested. Also, all Lockridge data moved to new figure to improve the clarity of ANSS versus Lockridge data. Attachment 3, Page 12 of 53 Date Location in No. Received Report1 51 2/17/2015 Section 4.1.1, Page 4-1 52 2/17/2015 Section 4.1.3, Page 4-3 53 2/17/2015 Section 4.2.1, Page 4-4 54 2/17/2015 Section 4.2.2. Page 4-5 55 2/17/2015 Section 4.2.4. page 4-7 56 2/17/2015 Section 4.2.4. Page 4-7 57 2/17/2015 Section 4.2.5, Page 4-7 58 2/17/2015 Section 4.2.6, April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision that the catalog includes both statistical types of events. The symbol for the Lockridge clusters is not clear on the map vs. what is in the figure legend. Perhaps a small circle around each cluster could be used as the svmbol. " ... migrated from west to east, tracking the (Same) westward migration ... " If it migrates from west to east, then the tracking should also be west to east, not westward. Is this what you meant?? 25 Ma? Doesn't Atwater say 28 Ma? NIA Isn't the Sand Tank fault to the SE of the site? (Same) "the ISB has produced 3 historical scarp-(Same) forming earthquakes ... " Fig 4-9 shows only 2. Please clarify. " ... and three significant earthquakes ... " But (Same) you list 4 earthquakes(?) Please clarify. Is the Parkfield section really accommodating (Same) 30-mm/yr of creep? Or is that the section NW of Parkfield? If the fault initiated at a specific time, then it {Same) wasn't "Miocene to Pliocene". Was it one or the other? If unclear, specify, "initiated sometime in the Miocene or Pliocene". This seems to refer to only the major faults in {Same) PVNGS SSC Additional Documentation Summary of Revisions to Report Text fixed as suggested. Regarding the initiation of the modern transform plate boundary in California, Atwater (1970) says 28 Ma. As discussed by Stock and Hodges (1989), Atwater (1989) revised this number to 25 Ma. Atwater (1970) is still cited, however, to credit the origination of the plate tectonic reconstruction. No change to text. Text fixed as suggested. The Hebgen Lake earthquake is north of the view extent of the figure. All three earthquakes are now specified in the text. Text referring to seismicity along the creeping section of the San Andreas fault revised list four sianificant earthauakes. Creep is occurring northwest of Parkfield, text fixed as suggested. Text revised to specify late Miocene. Sentence added to name additional faults. Attachment 3, Page 13 of 53 Date Location in No. Received Report1 Page 4-8 59 2/17/2015 Section 4.2.6, Page 4-8 60 2/17/2015 Section 4.2.6, Page 4-8 61 2/17/2015 Section 4.2.6, Page 4-9 62 2/17/2015 Section 4.2.7, Par.ie 4-9 63 2/17/2015 Figure 4-13 64 2/17/2015 Section 4.1, Page 4-1 65 2/17/2015 Section 4.2.3, Page 4-6 66 2/17/2015 Section 4.2.7, Page 4-9 67 2/17/2015 Section 4.3, April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision the peninsular ranges north of the border. To the south, there is also the Agua Blanca, San Miquel, etc. Please clarifv. Superstition Hills earthquake was in 1987 (not (Same) 1986}. 15 large earthquakes? Yes, these would be the (Same) M7.2-7.3 events. However, the "small" events may have been at least as large as the 1918 earthquake -M6.9. Consequently, most would call all 21 events "larqe" Needs citations Mueller and Rockwell, 1995, (Same) Hough and Elliot, 200 , Fletcher et al., 2014} Hough 1994??? Didn't Rymer do the work on (Same) the surface ruptures for these faults?? For historical surface ruptures, this figure (Same) should include the 1910 Glen Ivy earthquake, the 1979 Homestead Valley earthquake, and the November 22, 1800 San Jacinto earthquake. Also, the Christmas Day, 1899 earthquake at Hemet produced some surface rupture. Recent is often used in exchange for (Same) Holocene, but what you really mean here is late Miocene to present Is it a segment or a whole fault on its own? (Same) There are better and more direct citations for (Same) these surface ruptures. Mike Rymer mapped them. References needed here. (Same) PVNGS SSC Additional Documentation Summary of Revisions to Report Text fixed as suggested. Text revised to state "21 moderate to large prehistoric earthquakes" have been interpreted along the northern and central San Jacinto fault in the past 4,000 years. Citations added. Yes, Rymer reference added. 1899 rupture already on figure. Remaining 3 ruptures added. Text revised as suggested. Text changed to "section". This is based on the USGS discussion of various sections of the Hurricane fault, which are defined based differences in structure. expression, and rupture history. This section would not be considered a distinct fault. Rymer (1992) citation added. Added Kreemer Workshop 2 reference, deleted Attachment 3, Page 14 of 53 Date Location in No. Received Report1 Pages 4-9 and 4-10 68 2/18/2015 Figure 4-6 69 2/17/2015 Figure 4-8 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision Figure 4-6 uses an inappropriate catalog for Figure 4-6 comparing the spatial distribution of seismicity Figure 4-8 with the distribution of faults. Please use the Figure 4-9 non-independent compiled catalog including Section events down to MO (described in the next 4.2.1, paragraph). Some categorization of Pages 4-4 earthquakes by size should be used so the and 4-5 smallest events neither get lost nor dominate the figure. There needs to be a discussion in the text regarding the relationship between the patterns of seismicity and the locations of Quaternary faults. It would be necessary for this and the subsequent figures to compile existing earthquake focal mechanisms to illustrate for the reader the current tectonic styles within the site region Figure 4-8a needs to be updated using the Section non-independent compiled project catalog that 4.2.1. includes all seismicity in the in the model Pages 4-4 region (i.e .. the independent catalog with all the and 4-5 excluded events included and magnitudes down to near 0). This figure could be discussed with respect to possible associations with tectonic provinces. The relationship between felt and instrumental seismicity with respect to mapped faults will need to be assessed using a figure that includes both faults and seismicity. Figure 4-8a currently uses two possibly overlapping catalogs (the ANSS catalog and the NASB catalog); the project independent plus non-independent earthquakes down to MO should be used for making this figure and PVNGS SSC Additional Documentation Summary of Revisions to Report comparison to northern Basin and Range. Figure 4-6, earthquakes removed. This figure only ever cited now in reference to the distribution of Quaternary faults in the Site Region. There is no discussion of the association of seismicity with mapped Quaternary faults, since we model all faults from QFDB as active sources. However, we have added or revised several figures to the sequence in Figure 4-8 that allow the detection of UNMAPPED faults based on patterns of seismicity. These new figures are accompanied by new text in Section 4.2.1. New focal mechanism figure also added and is part of this discussion. The project catalog does not include any events that are smaller than M2.7, since it was constructed for PSHA calculations. Instead. in response to this comment. we have used "off the shelf' catalogs from ANSS and AZGS that go down to MO. Associated discussion is added to Section 4.2.1. Attachment 3, Page 15 of 53 Date Location in No. Received Report1 70 2/17/2015 Figure 4-8 71 1/13/2015 Section 5.1.3, Page 5-2 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision discussing what it shows. There is no special benefit to using the ANSS catalog. as it is likely to be less comolete than the compiled cataloq Figure 4-8b uses two other catalogs for a Section comparison of seismicity with tectonic 4.2.1. provinces. The non-independent compiled Pages 4-4 project catalog should be used again. If and 4-5 Quaternary faults were added to this figure. it would be a zoom-in of Figure 4-6. An additional figure is likely needed to zoom in on the region within about 60-100 km of the site, thus including the Sand Tank fault and the region containing the new geologic mapping. The seismicity within this region is known to be sparse. Efforts should be made to obtain focal mechanisms from the better-recorded (and thus the larger) earthquakes within this region. These mechanisms should be compared with available geodetic data to evaluate the degree of consistency Chapter 5 Does the first sentence actually mean that the (Same) number of areal sources considered by the five teams ranged from 10 to 17? Similarly, the second sentence could be recast to say that four of the teams used between 4 and 23 fault sources, with the fifth group defining 94 fault sources. Why is this important enough to discuss here? Do you want the readers to compare these numbers with the number of aerial and fault sources used in the present study or to show how variable a result different teams can generate? Please revise this PVNGS SSC Additional Documentation Summary of Revisions to Report See above. No focal mechanisms are available for southern Arizona. Text revised to clarify the range in number of fault and areal sources defined by the five teams. This information is provided for context and to indicate the relatively small number of fault sources in these earlier SSC models. Attachment 3, Page 16 of 53 Date Location in No. Received Report1 72 1/13/2015 Section 5.3, Page 5-3 73 2/17/2015 Section 5.1.4, Paoe 5-3 74 2/17/2015 Section 5.3, Page 5-4 75 1/13/2015 Section 6.0, Page 6-1 76 1/13/2015 Section 6.1, Page 6-1 77 1/13/2015 Section 6.1, Page 6-1 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision paragraph to clarify why this information is important to the SSHAC process. The term "reference evaluation" is not {Same) explained. Please clarify to what extent there is an evaluation of the references and describe how this evaluation was used in the SSHAC process. Note about anchoring here? {Same) This section is not clear. {Same) Chapter6 You might want to consider some alternatives {Same) to the current title. During the development of the earthquake catalog, the term "Composite Earthquake Catalog" has been used. which is more descriptive of the catalog than "Project Earthquake Catalog". The catalog could also be called "Declustered Earthquake Catalog" or "PSHA Catalog" to focus on its use in PSHA calculations. In consideration of Comment C below, there may be a need for having a "Complete Earthquake Catalog" that contains all the seismicity in the region of interest for use in accessing seismicity associated with geological structures. This paragraph is written in a highly formal and {Same) stilted style, more suited to a legal brief than a scientific report. Please rewrite in a style consistent with the rest of the report. In this paragraph and several earlier {Same) paragraphs, the term "significant earthquakes" is used without clear definition. Based on the PVNGS SSC Additional Documentation Summary of Revisions to Report Text revised to define "reference evaluation" and to provide enumerated list of why and how this is used in the SSHAC process. Text added to address how the Tl Team avoided beino anchored to the base case model. Text revised to improve clarity. CATALOG OF INDEPENDENT EARTHQUAKES FOR PSHA, thus making it clear that this is a catalog of independent events intended to be used for Probabilistic Seismic Hazard Analysis. The paragraph has been re-written. Significant earthquakes are defined as magnitude 2. 7 or higher in the eastern portion of the study region and >4.7 is in the west. This Attachment 3, Page 17 of 53 Date Location in No. Received Report1 78 1/13/2015 Section 6.1, Page 6-1 79 1/13/2015 Section 6.1, Page 6-1 80 1/13/2015 Section 6.2 81 1/13/2015 Section 6.2, Pages 6-2 to 6-3 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision catalog selection criteria. the significant events appear to be those of M2. 7 or larger in the study region (4. 7 in the higher activity part of the study region as shown in Figure 1 }. Please clarify the meaning of "significant earthquakes" with a comprehensive definition including scientific and enqineerinq aspects. The composite catalog that is prepared using N/A the six-step procedure outlined in the fourth paragraph of this section does result in a catalog that is composed of statistically independent earthquakes. What about in the cases where '"aftershocks" are part of a sequence of large earthquakes, where rupture continued or extended along a fault zone {cf. Darfield sequence). There are also cases of a large regional earthquake triggering moderate to large earthquakes on independent faults-how are these cases addressed? The term "study region" was tentatively defined {Same) with an equivalent term "model region," with "study region" used more than "model region." Please explain in more detail why this region was defined, why its radius is 400 km, and provide references to other sections of the report where this term is used. The PPRP expects that Section 6.2 will be {Same) significantly revised and edited to address the PPRP comments on Section 6.2. This section is generally disjointed in terms of {Same) providing a systematic set of information that is needed for vetting the earthquake catalog data. PVNGS SSC Additional Documentation Summary of Revisions to Report explanation has been added to the text. In the Darfield sequence, the large M7.1 earthquake is considered the main shock (independent). The smaller, but still large, earthquakes that followed this event would be considered aftershocks (dependent), regardless of the amount of damage they caused. Moderate earthquakes on independent faults triggered by larger regional earthquakes are also assumed to be dependent. PSHA methodology requires a catalog of independent events. Note that large events specifically identified with a known fault were also removed from the catalog, in order to avoid double counting. No change to text. The 320 km radius comes from Reg. Guide 1.208 recommendations, and the text has been revised to state this. This revised text also presents language from Reg. Guide 1.208 that indicates why an SSC model might want to exceed this radius. The 400 km radius is now consistently called the "model region" throughout. Section 6.2 has been completely rewritten to discuss the features of each network, as obtained from network operators and catalog websites. Section 6.2 was completely rewritten to address this issue. Text revised to state that the final catalog spans Attachment 3, Page 18 of 53 Date Location in No. Received Report1 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision The data from various individual networks and several catalog compilations of data from an unidentified set of networks have been used in previous chapters. It would be important to discuss the features of each network as appropriate for the data to be used from the network. The basic monitoring framework is as follows: The relevant ANSS regional networks are in California, Nevada, and Utah. There is a small university-operated regional network in Northern Arizona. USGS operates the US National Network out of Colorado covering all states with a sparse network, and the Mexican network monitors the area south of the border. In parallel with the regional and national networks. there are organizations that compile reprocessed catalogs of earthquake locations and source characteristics using raw data from the above various sources. It should be carefully noted that this composite catalog is NOT likely suitable for assessing the presence of active faults. Because of the method used to create this catalog, all foreshocks and aftershocks have been removed; yet a catalog that includes all seismicity {and with duplicates removed) could be useful in comparisons with Quaternary fault maps in seeking evidence for fault activity based on clustered seismicity (including foreshocks and aftershocks) along a mapped fault trace or where no mapped faults have been found. Please address this issue as appropriate in this and other sections of the report. PVNGS SSC Additional Documentation Summary of Revisions to Report 160 years, ranging from 1852 -2012. Also, the title of this chapter has been revised to make it clear that this is a catalog of independent events and intended to be used for PSHA. The text now specifically states that the final catalog may not be suitable for assessing the presence of active faults. Attachment 3, Page 19 of 53 Date Location in No. Received Report1 82 1/13/2015 Section 6.8, Page 6-7 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision This section is important and depends on the {Same) definition of catalog completeness. Please clearly define what completeness means and how it is related to the activities of a seismic network operator (see suggestions for reworking Section 6.2). There is a tendency in this section to use sparse explanations and jargon; future readers would appreciate more clear explanations. The second sentence in the first paragraph is, "Unfortunately, several regional networks contributed to the PVNGS catalog and obtaining this type of information for each would be time-consuming." The message this sentence communicates is that nuclear power plant safety is not worth a time-consuming activity-the PPRP is certain that this attitude is not held by the Tl Team and is a misstatement. The lack of compiling data regarding the history and operation of the regional seismic networks surrounding and covering the PVNGS site vicinity and site study area was noted in our comment on Chapter 6.2. We strongly suggest that the basic spatial, instrumentation. and operational data be collected from the relevant network operators and be used to estimate modeled network completeness. We are reasonably confident that you will find that the network personnel have already done the "time-consuming" work that is needed These results can be compared with the composite catalog analyses that you have already carried out to reach a sound conclusion on catalog completeness as a PVNGS SSC Additional Documentation Summary of Revisions to Report The explanation of catalog completeness has been expanded. The second sentence in the first paragraph was poorly worded and could easily be misconstrued and was therefore removed. After the paragraph defining completeness times, the following line was modified to stress that applying statistical procedures such as the Stepp methodology is the preferred way to obtain completeness times. "Fortunately, a much better commonly used alternative approach is to use statistical procedures on the catalog itself." Variations of the Stepp methodology are frequently used to determine completeness times for PSHA. Completeness time data was requested from network operators but mostly inadequate information was received; primarily because many of the regional networks have only existed for a relatively short period of time. The statistical analysis of the catalog suggests that most completeness times for magnitude intervals of interest (above M4.0) extend back prior to the installation of many of the regional networks. In Arizona for instance, the record of >M4.0 events appear to be complete since 1920 but the first USGS instrument wasn't installed at Flagstaff until 1961 and NAU's three station network didn't start monitoring until 1986. The explanation of course is that when Lockridge et al. 2012, compiled the Arizona catalog he used data from other sources such as Dubois (1982) and newspaper accounts of felt reports in order to fill in the pre-instrumental record. In contrast, the Attachment 3, Page 20 of 53 Date Location in No. Received Report1 83 2/17/2015 Chapter6 84 2/17/2015 Section 6.1, April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision function of time. The title and subsequent terminology should Throughout be clearer. The objective is to have a catalog of Chapter 6 events that are statistically independent of each other, thereby not including foreshocks, aftershocks, or swarm-like occurrences. Since there also needs to be a complete seismicity catalog that includes the events excluded from the statistically independent catalog, it needs a meaningful name, such as "historical catalog" or "composite catalog". There are several additional names for the "independent" catalog in Chapter 6, such as "project catalog," "final catalog", "data catalog", "final PVNGS catalog," "comprehensive composite catalog", etc.-please pick two names for the two catalogs used in the SSC study, and don't use any others. It would be helpful to the reader to explain the characteristics of the two catalogs in this introduction, pointing out that the independent catalog is used for evaluating recurrence of future earthquakes for earthquakes magnitude 2.7 and larger, while the "more complete" catalog (name not established yet) contains all reported earthquakes in the region {needs to be specified) including earthquakes smaller than M2.7. In particular it is necessary to have a "complete" seismicity map within the 320-km-radius region around the PV site to support a discussion of the association of seismicity with QeoloQic structure and faults. Was there any explicit consideration of swarm-NIA PVNGS SSC Additional Documentation Summary of Revisions to Report network operator at AZGS maintains that M4.0 are complete since 2007 and M5.0 since 1970. As discussed in the Chapter 4 comments and responses, there is no version of the catalog that includes earthquakes below M2.7. In that case, our "complete" catalog prior to declustering cannot meaningfully be used to search for seismicity lineaments. The pre-declustering catalog also has no utility in terms of PSHA. It is therefore not presented. In chapter 4, ANSS and AZGS catalogs down to MO are used to search for spatial trends in microseismicity. The catalog is now consistently referred to as "the PVNGS catalog" Would have been removed in declustering Attachment 3, Page 21 of 53 Date Location in No. Received Report1 Page 6-2 85 2/17/2015 Section 6.2.1, Page 6.2 86 2/19/2015 Section 6.1, Page 6-1 87 2/19/2015 Section 6.2.1, Page 6-3 88 2/19/2015 Section 6.5, Page 6-8 89 1/19/2015 Section 7.0, Page 7-1 90 1/19/2015 Section 7.0, Page 7-1 91 1/19/2015 Section 7.0, Page 7-1 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision like occurrences, with no distinct main-shock? Or would they be identified by the foreshock-aftershock alqorithm? Please clarifv in the text. The role of the NAU needs to be discussed; is NIA the Northern Arizona Network now formally operated by AZGS personnel? Please clarify. Are quarry blasts confidently and systematically identified and excluded? Please clarify. "significant recorded earthquakes" -does this {Same) include historically reported earthquakes or only those that are instrumentally recorded? Please clarify. Under "Dates of Operation: were the early NIA Tucson seismograph records used? These date back to the first 2-3 decades of the century. Is "unk" a magnitude scale?? (also in Table 6-NIA 2). You mean that the magnitude scale that was used is unknown, but this is treated as a scale in and of itself. Is there a better way to indicate this? Chapter 7 Please remind the reader that Chapter 4 has {Same) substantial background information relevant to this chapter's focus on the Basin and Range province. Is this the same as saying "the general (Same) absence of tectonic landforms"?? What type of non-tectonic landforms are you referring to? Please clarify. The Lake Mead area is contiguous with (Same) northwestern Arizona--are these the same PVNGS SSC Additional Documentation Summary of Revisions to Report process, as described in Section 6.1 {only largest event retained). One of the focuses of Lockridge was swarm identification. No change to text. NAU is integrated into the Arizona network. AEIC is run out of NAU, but is part of AISN. No, NAU not operated by AZGS personnel. But shared data with AZGS. No change to text. "Significant recorded" includes both instrumental and historical earthquakes. Text to this effect has been added. We assume that the AZGS catalog delivered by Jeri Young (1852-2012) includes earthquakes recorded in the early 1900s from Tucson. No change to text. "Unk" means the original magnitude scale is unknown. As shown in Table 6-3, "unk" events are treated as equivalent to Mw (Petersen et al.. 2008). No change to text. Text revised as suggested. "Non-tectonic landforms" removed, we discuss the geomorphology of the landscape instead. Yes, "Lake Mead" has been removed from this sentence as suggested. Attachment 3, Page 22 of 53 Date Location in No. Received Report1 92 1/19/2015 Section 7.0, Page 7-1 93 1/19/2015 Section 7.0, Page 7-1 94 1/19/2015 Section 7.0, Page 7-1 95 1/19/2015 Section 7.0, Paqe 7-2 96 1/19/2015 Section 7.0, Page 7-2 97 1/19/2015 Section 7.0, Page 7-2 98 1/19/2015 Section 7.0, Paqe 7-2 99 1/19/2015 Section 7.0, April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision tectonic area? Isn't this a real discrepancy? Please explain {Same) your point. Could this be an issue of having an incorrect NIA Euler pole? At what rate? {Same) On any maps? Please specify/clarify. {Same) Certainly the late Quaternary. Can you {Same) preclude early Quaternary? Please clarify. There should be a discussion of seismicity in NIA the site region in parallel with the other four topics. What kinds of geologic rates? {Same) Why is seismicity missing from this discussion? NIA PVNGS SSC Additional Documentation Summary of Revisions to Report "Apparent" removed from the sentence describing comparatively low geologic extension rates and higher geodetic extension rates in Arizona. No change to text. Geodetic data are mentioned here to introduce the discrepancy in extension rates and not to offer potential explanations for whv. Cumulative geologic extension rate for the interior of the northern Basin and Range from Koehler and Wesnousky (2011) included for reference. Phrase "or shown on maps" deleted. Text revised to "Are large portions of the southern Basin and Range completely devoid of faults that have ruptured in the middle to late Quaternary?", which is the time range covered by later discussion. Discussion of seismicity in the site region is provided in Chapter 4. In response to comments in Chapter 4, those discussions will be expanded to describe the lack of spatial association between seismicity and mapped faults in Arizona. To clarify. Chapter 7 describes the issues that the Tl Team had to wrestle with before constructing the model. The paucity of seismicity in Arizona meant that seismicity was not something we could use to evaluate Quaternary faulting. No change to text. Text revised to specify "rates of extension". Discussion of seismicity in the site region is Attachment 3, Page 23 of 53 Date Location in No. Received Report1 Page 7-2 100 1/19/2015 Section 7.1.1, Page 7-3 101 1/19/2015 Section 7. 1 . 1, Page 7-3 102 1/19/2015 Section 7.1.1, Page 7-3 103 1/19/2015 Section 7.1.1. Page 7-3 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision What does this mean -please clarify. (Same) The background for this first mention of (Same) seismicity needs to be established earlier in this chapter. The total seismicity catalog needs to be used to look for associations with geological structure. The composite declustered catalog is not suitable for such comparisons as noted in our comments on Chapter Six. The presence or absence of seismicity? Please (Same) clarify. In the PPRP comments on Chapter 6. it was (Same) pointed out several times that the declustered catalog is an improper choice of catalog to search for spatial correlations between seismic activity and possible active-fault-related features. The declustered catalog is missing foreshocks and aftershocks and also is limited to earthquakes larger than M2.7--microearthquakes have been found useful for correlating with active faults--see for example the significance of the location of a small PVNGS SSC Additional Documentation Summary of Revisions to Report provided in Chapter 4. In response to comments in Chapter 4, those discussions will be expanded to describe the lack of spatial association between seismicity and mapped faults in Arizona. To clarify, Chapter 7 describes the issues that the Tl Team had to wrestle with before constructing the model. The paucity of seismicity in Arizona meant that seismicity was not something we could use to evaluate Quaternary faultinQ. No chanQe to text. Text clarified. Text revised to clarify that seismicity was not a determining factor in this analysis. Text revised to clearly state that the analysis of seismicity was not a determining factor in this analysis. Text revised to clarify that sparse seismicity was not a function of the declustered catalog, it is a characteristic of all earthquake catalogs covering the southern Basin and Range. Attachment 3, Page 24 of 53 Date Location in No. Received Report1 104 1/19/2015 Section 7.1.2, Page 7-4 105 1/19/2015 Section 7.2, Page 7-5 106 1/19/2015 Section 7 .2. 1, Page 7-5 107 1/19/2015 Section 7.2.1. Paqe 7-6 108 1/19/2015 Section 7.2.3. Page 7-8 109 1/19/2015 Section 7.2.3, April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision number of microearthquakes along the surface trace of the Shoreline fault offshore of Diablo Canyon. We recommend that a composite earthquake catalog be assembled to cover the 400km-radius study region. This catalog should include all seismicity reported by the cognizant seismic networks down to magnitude zero. The catalog must exclude non-natural seismic events including mining and construction explosions, sonic booms, and any other types of non-natural seismic events that are in the source catalogs. This complete natural seismicity catalog can be used to search for spatial and focal mechanism correlations between mapped geologic features and seismic activity in the Study Region. Such as gravitational collapse? What factors? {Same) Was Google Earth used for some of this?? (Same) Recall that the explanation on this quad had some errors and AGS promised to repair and reissue the map as v. 2 Please explain why this was done. {Same) This phrase may be from the dePolo and {Same) Anderson paper, but is seems misleading to have all the uncertainty on the greater side of the central value; what is likely meant is that there is an uncertainty of half an order-of -magnitude about the values of 0.001, 0.01, and 0.1. Using "or greater" is somewhat misleadino. Please clarifv. Certainly there is a range. Please specify. {Same) PVNGS SSC Additional Documentation Summary of Revisions to Report Sentence deleted. Yes, "Google Earth" added. AZGS has not yet published a revised version of this map. No change to text. Explanatory text describing why LCI conducted field investiqations added. Text has been revised to more explicitly reflect dePolo and Anderson's (2000) interpretations and conclusions. Text has been revised to more explicitly reflect Attachment 3, Page 25 of 53 Date Location in No. Received Report1 Page 7-8 110 1/19/2015 Section 7.2.3, Page 7-8 111 1/19/2015 Section 7.2.3, Page 7-8 112 111912015 Section 7.2.3.2, Page 7-10 113 111912015 Section 7 .2.3.2, Page 7-10 114 111912015 Section 7.2.3.2, Page 7-10 115 111912015 Section 7.2.3.3, Page 7-10 116 111912015 Section 7.2.3.3, Page 7-10 117 111912015 Section 7.2.3.3, Page 7-11 118 1/19/2015 Section 7.2.4, Paqe 7-13 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision Please provide a reference for this -seems too {Same) fast. Plus, are there not 100 ka scarps preserved in eastern Arizona? If you are citing the Machelle constraint of {Same) Hanks, its degradation of a 1 m high scarp in 100 kyr in desert climates of Southern New Mexico, which are comparable to your area. Read and cite the ref. Is this the same as evidence against? Please (Same) clarify. Please comment on the level of uncertainty. (Same) Could a half meter scarp be missed? 1 m? This is not a strong statement. One caveat is that strike-slip motion may not (Same) induce a vertical component and thus not be seen. Can you add that your saw into the deposits and didn't detect any faulting to them. This statement is not clear. What is meant by (Same) "this mapping project?" This chapter has several discussion of lineations; please clarify. Are their rate estimates points or bins? If bins, NIA revise prior citations of rates for dePolo and Anderson. Or it is an intrabasinal fault unrelated to any NIA now inactive fault at the front of bedrock. I don't buy it as an older Bull fault just because its way out there in the basin. How is this addressed in the SSC? {Same) PVNGS SSC Additional Documentation Summary of Revisions to Report dePolo and Anderson's (2000) interpretations and conclusions. 100 ka value comes from analysis described by dePolo and Anderson (2000). Text expanded and revised to mention the Machette constraint and Hanks et al. (1984). Text clarified to indicate "evidence for the absence of' activity. Text has been modified to provide qualitative caveat. We're highly certain that the Qi2 surface is not deformed, but less certain that this surface actually overlies the fault. Paragraph revised to clarify what could be and what could not be observed. Citation to LCI (2014) added to clarify "this mapping project". These slip rates are not bins. as described in revised text describing dePolo and Anderson slip rate categories in Section 7.2.3, Page 7-8. No change to text. We agree. Characterization of the Sand Tank fault in Chapter 10 gives low weight to the 0.001 slip rate that would follow from the interpretation that this is a Type 3 fault of Bull (2007}. No change to text. Section 7.2.4 rewritten to more clearly tie the results of this investiqation to the SSC model. Attachment 3, Page 26 of 53 Date Location in No. Received Report1 119 1/19/2015 Section 7.2.4, Page 7-13 120 1/19/2015 Section 7 .3, Page 7-13 121 1/19/2015 Section 7.3, Page 7-13 122 1/19/2015 Section 7 .3, Page 7-13 123 1/19/2015 Section 7.3, Page 7-13 124 1/19/2015 Section 7.3, Page 7-14 125 1/19/2015 Section 7.3.1. Page 7-14 126 1/19/2015 Section 7.4, Page 7-14 127 1/19/2015 Section 7.4, Page 7-14 128 1/19/2015 Section 7.4, April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision You might include here a statement that if {Same) there are potentially active fault sources within the site vicinity, their rates must be very low and covered by the aerial fault source model. Really. There are lots of slower faults there if {Same) vou look at the Quaternarv fault dataset. For how long? 100 ka? 1 Ma? {Same) You refer to this type of analysis earlier but provide no explanation. Perhaps move this discussion up? This was all stated earlier. Please combine and {Same) delete the redundancy Wasn't this stated earlier? {Same) In hind sight. it may be good to define what is {Same) meant here for the non-expert Most of the discussion in this and the following Figure 7-2 paragraphs refer to the Basin and Range and Figure 7-23 portions thereof. Please use consistent terminology and provide maps that show the locations of the Basin and Range elements. Here, central Nevada is said to have low rates, {Same) whereas in the preceding lines, the Central Nevada seismic belt is said to have relatively hiqh rates. Please clarifv. This will need to be justified. Do you assume (Same) PVNGS SSC Additional Documentation Summary of Revisions to Report Specifically, the first and last bullet points indicate what would have been added to the model if the Site Vicinity mapping had found local Quaternarv faults. Section 7.2.4 rewritten. We would like to avoid discussing the model as much as possible in Chapter 7. Since the point of the Site Vicinity mapping was to determine whether or not a local host source and local Quaternary faults could be defined, this section simply ties the mapping efforts to those two items. Sentence deleted. Text clarified to frame this in terms of interseismic period. No change to text. In these long reports, we are ok with allowing for redundancy. Oftentimes readers skip around to specific sections. Text revised to point reader back to 7.2.3 for more detail. Basics are retained here. Paragraph largely deleted. Definition added. Figures revised to include boundaries of the northern Basin and Range. Text now specifies eastern Nevada to avoid confusion between this part of Nevada versus the Central Nevada seismic belt. Justification added. Attachment 3, Page 27 of 53 Date Location in No. Received Report1 Page 7-15 129 1/19/2015 Section 7.4, Page 7-15 130 1/19/2015 Section 7.4, Page 7-16 131 111912015 Section 7.4, Page 7-16 132 111912015 Section 7.4, Page 7-16 133 111912015 Section 7.4, Page 7-17 134 1/19/2015 Section 7.4. 1, Page 7-18 135 1/19/2015 Table 7-4 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision this rate because all of the faults in this category are very poorly expressed, so based on their morphology, should have rates below this value? Please elucidate. Seems a bit shallow for the state on average NIA The point of this statement is not clear. What is N/A the issue for earthquake recurrence that is significant to PV? It might be also worth discussing that an M7 or (Same) M8 earthquake should rupture the surface and be locked into the geomorphology for tens of thousands of years. Over this timeframe, there should be a significant number of scarps, as are observed in the northern B&R. Thus. there is no evidence of the past occurrence of such events. supporting the low rates inferred from geology. You might mention the distance to the site. Has NIA a sensitivity analysis been conducted to see if this makes a difference? Dip slip? Won't you still see scarps? NIA Are you saying that there are likely numerous NIA unidentified faults in the southern B&R? In comparing tables 7-2, 7-3, and 7-4, different {Same) slip rates are used to calculate the number of PVNGS SSC Additional Documentation Summary of Revisions to Report We agree, but this is the crustal thickness value used by Corne Kreemer in his presentation. which the text is referencing. No change to text. This statement was added to close the interseismic window on events of this size, and show what a more conservative recurrence interval would look like when comparing the geodetic prediction of recurrence versus observed recurrence. No chanqe to text. Good suggestion, text added. No such sensitivity analysis has been performed. No change to text. If creep rates were high. we might see this in the landscape. At low creep rates, we probably wouldn't see them. No change to text. This list is discussing generic problems associated with geodetic rates, not necessarily issues specific to the PVNGS model region. No change to text. Table 7-3 has been revised to match the slip rates used in Table 7-2, and to include the Attachment 3, Page 28 of 53 Date Location in No. Received Report1 136 2117/2015 Chapter 7 137 2117/2015 Figure 7-20 138 2/19/2015 Section 7.2.3.1, Page 7-10 139 2/19/2015 Section 7.2.3.4, Page 7-13 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision expected faults required to satisfy the observed strain rate. It would be nice to have these all the same because it would be easier to then calculate expected versus observed for any given class. Assuming 0.1 mm/yr, 17 normal faults are required, but Table 7-2 skips from 0.05 to 0.2 mm/yr for the percentage of scarps preserved after 25 ka. At 0.05 mm/yr, scarps are preserved after 25 ka. The argument should be made that it would be hard to miss 33 faults if randomly generated in time (Poissonian). Extensive comments on the need for further NIA discussion of seismicity are found on Page 4-14 of the PPRP comments on Chapter 4. A substantial case has not been made that seismicity in the region does not provide information relevant to Quaternary faulting that may be significant to the site. Add Gila River lineament to caption? Sanford (Same) doesn't use the word lineament in the title of his paper. just fracture zone. May want to check this. or put lineament in parentheses with purple arrows. Same comment for fig. 7-21 The lack of deformation on the Palo Verde clay (Same) does not preclude 50-100 m of down-to-the-SW displacement on the inferred fault because they are of different ages. It just means that if such displacement exists, it predates the PV clav. In assessing the actual existence of this (Same) proposed structure, is there any evidence for or against its presence in the bedrock structure? PVNGS SSC Additional Documentation Summary of Revisions to Report correct number significant digits. Table 7-4 has been partially revised to include slip rates of 0.001 and 0.005 from Table 7-2 (as well as to include correct number of significant digits in all places). Other slip rates on the order of 10-2 and 10-1 remain unchanged, as the scarp degradation argument is less applicable here. Specific slip rates instead illustrate order of magnitude changes in slip rate and number of faults, with 0.5 mm/yr included for comparison to ECSZ faults. Text updated as needed to reflect these values. See chapter 4 responses. No change to text. Removed "lineament". Agree. Text revised to state no displacement since 2.8 Ma. Given hypothesized breadth of Soccorro fracture zone and scale of geologic mapping, we cannot definitely state that Tertiary strata are not Attachment 3, Page 29 of 53 Date Location in No. Received Report1 140 2/19/2015 Section 7.2.4, Page 7-13 141 2/19/2015 Section 7.3, Page 7-14 142 2/19/2015 Section 7.4, Paqe 7-17 143 2/19/2015 Section 7.4, Page 7-17 and 7-18 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision Yes, young structures cross-cut it, so clearly not active, but it seems to me that an even stronger statement is if Tertiary strata are not affected, and there must be good mapping of the Mesozoic and tertiary strata in that region. Is there a NE-striking bedrock fault or other structure? Same comment in the next paragraph -absence of scarps is a weak statement. Absence of an actual bedrock fault is strong. In the case of the Gila River, the unnamed fault mapped by Gilbert may constitute such a fault in bedrock, and you showed that old Pleistocene surfaces were not faulted. That is a stronqer statement than lack of scarps. " ... possibility of extremely rare ... " What is the {Same) basis for "extremely rare" when it is young alluvium? Also, the last sentence of this bullet is unclear. Comparing northern and southern B&R fault NIA scarps implies similar k values. This may be valid if the climate between the two regions has been the same throughout the time period over which the scarps are evaluated. Is this defendable? 2 mm/yr?? Do you mean 0.2 mm/yr? Please {Same) confirm. Another aspect of creeping faults is that they {Same) typically have abundant microseismicity because, although creep itself may be aseismic, there are usually numerous minor asperities along all faults and these tend to light up along creeping faults. The absence of microseismicity trends (or microseismicity PVNGS SSC Additional Documentation Summary of Revisions to Report affected. Statement about old Pleistocene surfaces added. "Extremely rare" deleted. Parenthetical added to last sentence to clarify. We weren't aware of any studies that made a strong case for differing climates over the timescale in question. No change to text. Fixed. should be 0.2 mm/yr. Sentence to this effect added. Attachment 3, Page 30 of 53 Date Location in No. Received Report1 144 2/19/2015 Section 7.4.2, Page 7-20 145 2/19/2015 Figure 7-21 146 1/19/2015 Section 8. 1 , Page 8-1 147 1/19/2015 Section 8.1, Page 8-1 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision associate with faults) is a strong argument against the presence of creeping faults. "The arid Arizona landscape ... " Yes, it is NIA currently arid, but what about the late Pleistocene. It may have been less arid although CaC03 was still accumulating. This would be a stronger statement if quantified with the fact that secondary carbonate is a component of sB&R soils throughout the middle to late Pleistocene so climate has always been arid to semi-arid, making the case for slow geomorphic change. An alternative argument or concept to think about is that if the climate has been arid for several hundred thousand years, as appears to be the case, the vegetation has likely always been sparse. In that case, would short-term wet periods have a more dramatic effect on the landscape because of the lack of vegetative cover? Just thoughts ..... not sure you want to even address this in the report. What about the bedrock geology? Is there NIA even a fault mapped in the Tertiary or Mesozoic rocks? The absence of a "bedrock" fault would be even stronger evidence against the activity of this inferred structure. Chapter 8 Perhaps this little explanation would be helpful (Same) at this point. Please consider having two bulleted sup-(Same) paragraphs to describe areal sources and fault sources. PVNGS SSC Additional Documentation Summary of Revisions to Report Thank you for the suggestion. We prefer to not introduce this argument though, as it may be a bit speculative. No change to text. No there are no faults of that orientation (on the state-wide geologic map). Text stating that 'there are no large-scale bedrock faults mapped along the trend of the Socorro fracture zone, but several cross-cut this trend" added. No change to text. Text revised to explain areal sources and their logic tree parameterizations. Instead of bullets, we inserted a hard return to start fresh paragraphs for the introduction of areal sources and fault sources. Attachment 3, Page 31of53 Date Location in No. Received Report1 148 1/19/2015 Section 8. 1 , Page 8-1 149 1/19/2015 Section 8. 1 , Page 8-1 150 1/19/2015 Section 8.2.1, Page 8-2 151 1/19/2015 Section 8.2.4.1 152 1/19/2015 Section 8.2.4.1. Page 8-4 153 1/19/2015 Section 8.2.4.1. Page 8-4 154 1/19/2015 Section 8.2.4.1, Page 8-4 155 1/19/2015 Section 8.2.4.2, Page 8-7 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision Please clarify what "location" means; does in {Same) mean "anywhere within the specified areal source zone"? This is referred to as the Sonoran Basin and Throughout Range elsewhere in the report. report. This term was defined as a 400km circular Throughout region centered on the PVNGS site. However, report. it has been called both "model region" and "study region" or both in various places in the document. Please settle on your single preferred name, use it only, and make the appropriate changes in the entire document includinq the qlossary to achieve consistency. Isn't this similar to fault sources?? NIA Due to scientific advances like seismology. So {Same) is this a global issue or just for our region? Also what do you consider to be the duration of the catalog?? This implies a limited duration for the catalog {Same) for the source region of PVNGS. This sentence is overly complex and I've tried {Same) to simply it. Basically, magnitudes for these events are inferred by their maximum intensities, and may contain considerable error. This could be more explicitly laid out. PVNGS SSC Additional Documentation Summary of Revisions to Report Text revised to remove "location" and insert "geometry". The report text has been revised throughout to only refer either to the northern Basin and Range or the southern Basin and Range. The report text and figures have been revised throughout to only use "model region" when referring to the 400 km radius. Yes, this model for the spatial distribution of seismicity in an areal source is similar to a fault source. This model could also define smaller zones. The key concept is that we don't know where within the zone they are located. No change to text. Rephrased to clarify that this is a project-specific issues. Also, the issues is the limited number of earthquakes. rather than duration of the catalog. Rephrased to clarify that this is a project-specific issue. Also. the issue is the limited number of earthquakes, rather than duration of the cataloa. Accepted and further revised. The problem here is not the uncertainty (which is taken into account with E[M] and N*). it is the lumpy nature of the observed recurrence curve due to each MMI value mapping into a specific ErMl value. No chanoe to text. Attachment 3, Page 32 of 53 Date Location in No. Received Report1 156 1/19/2015 Section 8.2.4.2, Page 8-8, equation 8-7 157 1/19/2015 Section 8.2.4.2, Page 8-12 158 1/19/2015 Section 8.3.5, Page 8-19 159 2/17/2015 Section 8.3.5.2, Page 8-23 160 2/19/2015 Section 8. 1 , Pages 8-1 and 8-2 161 2/19/2015 Section 8.3.5.2, April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision This is true for a b-value of 1. Is it strictly true if NIA the actual b-value falls below 1? That's an interesting bias. Is this a form of NIA anchoring? Up to an Mmax of 8.2 (?) (Same) Is this math correct? Seven earthquakes in {Same) 1100 years, but 6 recurrence intervals. 1100 x 24 = 26.4 m. So is the average displacement (between events) divided by 6 (4.4 m) or 7 (3.8 m)? "relatively low slip-rate ... " relative can be {Same) interpreted as several mm/yr -how about very low slip-rate ... ? The Rockwell, oers. Comm. Citation should be (Same) PVNGS SSC Additional Documentation Summary of Revisions to Report Ab-value not equal to 1 is not a problem in this formulation. Only b<O or b=O are problematic. No chanae to text. The result of equation 8-12 (which favors values near is not really a bias. Also, the term anchoring is generally used to indicate a psychological tendency, not a mathematical one. No change to text. Text revised to clarify focus of paragraph. The inclusions of large magnitudes isn't necessarily a reason for using one approach over another. Instead, the paragraph now describes why the use of UCERF3 rupture sets and certain combined fault sources is a valid alternative to the WAACY approach. There are two internally consistent estimates, 6 events and six intervals ending at -1720 AD, or seven events and approximately 7 intervals, the seventh being approximated by the open period. The closed interval (6 and 6) method leaves out the information on recurrence interval contained in the length of the open interval. The latter 7 and 7 method leads to a less biased estimate of the recurrence interval {e.g., Biasi. 2013. WGCEP Appendix H) and a less biased estimate of average displacement. We used the latter approach. It seems to us inconsistent to use the approximate time for seven events (1100 years and counting) to represent six intervals. Parenthetical explanation added to text. Text describing normal faults of the southern Basin and Range revised as suggested. Onderdonk et al., 2013 cited. Attachment 3, Page 33 of 53 Date Location in No. Received Report1 Page 8-22 162 111912015 Section 9.1.1 Title 163 111912015 Section 9.1.1, Page 9-1 164 111912015 Section 9.1.2. Paae 9-2 165 111912015 Section 9.1.3. Page 9-3 166 1/19/2015 Section 9.2, Page 9-3 167 111912015 Section 9.2.2, Page 9-3 168 111912015 Section 9.2.3, April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision changed to Onderdonk et al., 2013, 2015 in review-I can provide the published paper version and the current new paper version Chapter9 Simply stating "Future earthquakes" implies NIA that they will actually happen, whereas they may never happen. Are we not really talking about the plausibility of future earthquakes? Earthquakes that may possibly happen? Perhaps some citations here? (Same) Are there data to support this opinion? What (Same) does reaional seismicitv tell vou? A normal faulting event of this magnitude (Same) would also have to extend for several hundred kilometers, which would cross-cut a variety of other structural features. This would have to be a very complex, multi-segment, multi-fault earthquake The region really is the 400-km -radius "model Throughout region" As far as I recall. this reason for calling report. this the "model region: has not been explained. Early in the report, the 400-k-radius region was called the model region or study region. I prefer using "study region" because it is a clearly understandable terminology. This implies that they are expressed in bedrock (Same) terrain. In fact, they are mappable as geologic structures but may still have no expression of activity. Please clarify exactly what is meant here. Why an M7.2? Landers, as you mention, was NIA PVNGS SSC Additional Documentation Summary of Revisions to Report Yes, they may or may not happen in reality, but we're describing future earthquake that will happen in the model. No change to text. Text revised to only rely on expert judgment. Text revised to include heat flow and reference that ties the base of seismicitv to isotherms. Text discussing Mmax value of M7.9 revised as suggested. The report text and figures have been revised throughout to only use "model region" when discussing the 400 km radius. We prefer this to "study region" because we studied many things that are more than 400 km from the site, but our model is (mostly) restricted to the area within 400 km of PVNGS. The term model region is defined in the first paraqraph of Chapter 8. Phrase describing faults in the East source changed from "poorly expressed outside of bedrock terrain to "poorly expressed". These were provided as ballpark examples of Attachment 3, Page 34 of 53 Date Location in No. Received Report1 Page 9-4 169 1/19/2015 Section 9.2.4, Page 9-5 170 1/19/2015 Section 9.3.1, Page 9-6 171 1/19/2015 Section 9.3.1, Page 9-6 172 1/19/2015 Section 9.3.1.2, Page 9-6 173 1/19/2015 Section 9.3.3.1, Page 9-8 174 1/19/2015 Section 9.3.3.3, April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision M7.3 so shouldn't the largest future earthquake be possibly larger? Centroid depth? The centroid is the average (Same) depth weighted by slip. How can these represent the deepest events? There is a subtle difference in the usage here, (Same) with southern capitalized as a source, whereas in the next line, it is not capitalized when referring to the southern portion of the Basin and Ranoe. Is this correct? In some chapters (or I am confusing with text Throughout from the SWUS GMC), SBR is defined as the report Sonoran Basin and Range. I need to check on this to make sure I am not cross-wiring ... Why is this done? The discussion in this (Same) section seems uncomfortably ad hoc. Primary fault with an antithetic secondary fault? NIA What are paired normal faults? Need to better define these. I can't think of any NIA PVNGS SSC Additional Documentation Summary of Revisions to Report earthquakes that, at the time they occurred, would have exceeded the characteristic magnitudes of the causative faults. We think that the future occurrence of M7.3 earthquakes in the background of the West source is unlikely, however, we still assign a 0.4 weight to M7.2, and 0.25 weight to M7.5 and larger. No change to text. Text revised to remove comparison to earlier regional centroid depths of Goff, and instead cite the depths determined by Castro in his primary study of the Canal de Ballenas area. Text revised to remove reference to the province, to avoid confusion. But yes, capitalization matters. Report text and figures have been revised throughout to only ever refer to the "southern Basin and Range physiographic province" or the "Southern Basin and Range (SBR) source" Corrected text to state that default weights described in 9.1.3 were adopted. These faults are not thought to constitute the typical combination of primary and antithetic fault, rather, they appear to bound keystone style grabens. This suggests they may be very high angle structures. We do not think or mean to suggest they are strike-slip faults, rather, we simply suggest that their orientation allows the possibility that they could accommodate lateral displacement (but not significant displacement). No chanoe to text. We do not think or mean to suaaest they are Attachment 3, Page 35 of 53 Date Location in No. Received Report1 Page 9-8 175 1/19/2015 Section 9.3.4.2, Page 9-9 176 1/19/2015 Section 9.3.5.3, Page 9-10 177 2/17/2015 Figure 9-34 178 2/19/2015 Section 9.2.6, Page 9-6 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision paired strike-slip faults in California, so perhaps it is more likely that these represent very low angle faults. A better discussion on these interesting faults may be in order -perhaps where they are first mentioned in section 9.3.3.1 Mmax don't represent the expected sizes of N/A earthquakes for a source region, Mmax is the largest earthquake that can be expected from a source region. As this region has already had a M7.5, shouldn't this be the smallest Mmax that is considered?? Except that is includes the San Miguel fault in {Same) Baja California, which is transtensional and the source for the 1956 M6.8 San Miguel earthquake. This may not reflect, then, the CBR of the TDI. Are we supposed to know what the Chapter 13 "realizations" are or refer to Case 2 magnitude weights? Usually realizations mean something like model run number. Insert "minor" between continued and {Same) extension (?) PVNGS SSC Additional Documentation Summary of Revisions to Report strike-slip faults, rather, we simply suggest that their orientation allows the possibility that they could accommodate lateral displacement (but not significant displacement). No change to text. Mmax would begin at M7.5 only if we place a high degree of confidence in the interpretation that an 1887 style earthquake is likely to occur anywhere within the Mexican Highlands in the future (i.e., only if we have high confidence that the Mexican Highlands contains active, unrecognized faults capable of 100-km-long ruptures). Areal source Mmax only needs to account for the largest earthquakes not occurring on modeled faults in that source. The weights of 0.3 and 0.05 at M7.5 and M7.9 allow for the possibility that 1887-sized earthquakes may occur in the background of the Mexican Highlands, whereas lower points in the Mmax distribution represent the interpretation that all such large, active faults are accounted for. No chanae to text. Text revised to clarify that future earthquakes are modeled to reflect the dominance of strike-slip faulting and local transpression in the eastern Transverse Ranges. The definition for the term "realization" has been added to the Glossary (Chapter 13). Text describing extension in the East source revised as suaaested. Attachment 3, Page 36 of 53 Date Location in No. Received Report1 179 2/19/2015 Section 9.3.5.2, Page 9-10 180 1/19/2015 Section 10.0. Page 10-1, 151 paragraph 181 1/19/2015 Section 10.1. Page 10-1 182 1/19/2015 Section 10.1, Page 10-2 183 1/19/2015 Section 10.2, Page 10-3 184 1/19/2015 Section 10.2, April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision What about normal faults in Baja -these don't NIA seem to be covered Chapter 10 The Sand Tank fault on figure 10-1 is NIA disproportionately long -shows it as nearly 30 km in length. whereas the scarp is less than 4 km in lenath. The San Miguel fault is transtensive, whereas (Same) the Agua Blanca fault is purely strike-slip. There are no reverse faults mapped or known in Baja California. Transpression in southern California is limited to the region generally north and east of the Elsinore and San Jacinto fault. How about strike-slip and transpressive? Perhaps don't include transpressive and Mexico in the same sentence. Distant fault sources? Long period only N/A Sections kind of replaced "segments", as there (Same) was considerable push-back on the idea of segmentation. Nevertheless, sections/segments were never boundaries, but the section of faults between boundaries. Perhaps it would be better to state that the fault sections were not delineated by primary boundaries to fault rupture. Or separated? Second time mentioned, what is the problem (Same) PVNGS SSC Additional Documentation Summary of Revisions to Report Text states that this breakdown reflects the dominance of strike-slip and reverse faulting in SCABA. It is also designed to model earthquakes on faults not already mapped. We judge normal faulting in Baja to be covered by the faults that are alreadv maooed. No chanoe to text. The Sand Tank fault source in Figure 10-1 includes the longest extent included in the model, consistent with the way all other fault sources are depicted. No chanae to text. Text revised as suggested. Especially at long period. but these are the most hazard significant fault sources in general. Further specifics provided in Chapter 11. No chanQe to text. Text revised as suggested. Sentence deleted. There is no problem with Attachment 3, Page 37 of 53 Date Location in No. Received Report1 Page 10-3 185 1/19/2015 Section 10.2, Page 10-4 186 1/19/2015 Section 10.2.1.1, Page 10-5 187 1/19/2015 Section 10.2.1.1, Page 10-5 188 1/19/2015 10.2.1.1, Page 10-5 189 1/19/2015 Section 10.2.1.1, Page 10-6 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision with FM3.2 that it wasn't used. Right. Why is Dr. emphasized here whereas Throughout many other proponent and resource experts report. that hold doctoral degrees are not indicated as such? Please include DR. for all doctoral resource and proponent experts. Woody's addendum: Per Tom's comment below, I suggest that the project establish a policy for this document along the lines Tom suggests. All the project personnel who have bios attached to the report should not have titles in the text of the report. Consultants, resource and proponent experts should have their titles included in the text. Why omitted, then you say as a result, it's {Same) modeled separately. Yeah, because you already omitted it. What's the logic driving this? Also, figures 10-12 to 10-14 are hard to explain NIA without ruptures extending from the San Andreas fault onto the Imperial fault-how else can the Imperial fault have so many rupture terminations? Is this really known? 1857 -yes. All earlier {Same) earthquakes are debatable. Just so the Tl team is aware of this, but {Same) Rockwell, Oglesby and Meltzner have a SCEC proposal submitted to test (model) whether this is possible, qiven what we know about the PVNGS SSC Additional Documentation Summary of Revisions to Report FM3.2, we were just being clear and specific about the inputs to our model. But the exclusive dependence on FM3.1 is already stated in the previous oaramaoh. Throughout: "Dr." deleted per suggested rule. Rewritten to more clearly reflect the logic of the layered San Andreas fault model. Figures 10-12 through 10-14 depict the fault as modeled according to the UCERF3 rupture set approach, which is why they are referenced in the preceding paragraph and not this paragraph {which describes the layered approach). No chanae to text. Text revised to add "are interpreted to". This statement is based on 1857 termination combined with interpreted terminations from Fumal et al. (2002). Rewritten to more clearly state that this approach is a low weight alternative to UCERF3. Regarding the defensibility of this interpretation, the fact that it is currently the subiect of Attachment 3, Page 38 of 53 Date Location in No. Received Report1 190 1/19/2015 Section 10.2.1.2, Page 10-6 191 1/19/2015 Section 10.2.1.2, Page 10-6 192 1/19/2015 Section 10.2.1.2, Page 10-6 193 1/19/2015 Section 10.2.1.2, Page 10-6 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision structural configuration and paleoseismic record. The paleoseismic record for the southern San Andreas fault MRE is identical to the ca. 1700 event on the Imperial fault. Thus, this interpretation may not capture the CBR of the TDI. Hmmm -20 from the southern San Andreas (Same) fault and 15 from the southern San Jacinto fault equals 35 mm/yr. Based on what? References here? Bennett Section puts 35 mm/yr on the Imperial fault itself, as do 10.2 most geodetic studies. The Thomas and Rockwell paleoseismic study covered too short of a window (2 events) to represent a long term slip rate, and new paleoseismic data indicate a faster rate. 25 mm/yr. is certainly within the ranqe, but is not the center. This rate was for the northern end of the (Same) Imperial fault. Assuming that the large slip events increase in displacement to the south, as did the 1940 and 1979 earthquakes. then the rate at the border could be as large as 35-40 mm/yr. This will be tested with new trenches in January and February (too late for this SSHAC), but the 10 mm/yr at the north end of the fault should not be used for rate estimates as it is north of the split with the Brawley fault and in an area of distributed strain. Okay, so 25 mm/yr on the Imperial fault, 3 on NIA the southern Elsinore fault. Are you then putting another 11 mm/yr on the Cerro Prieto fault and having it cross the border without adding to the Imperial fault, as in figure 10-17, panel A? This needs to be explained in the PVNGS SSC Additional Documentation Summary of Revisions to Report investigation indicates that this interpretation must lie somewhere in the realm of the CBR. Note that, on the UCERF3 rupture set branch, through-going ruptures between the Imperial and the San Andreas fault are allowed (branch weight of 0.8). Text revised to clarify that the Imperial rate is based on plate boundary transects in Figure 10-17. Section 10-2 revised to include more detailed discussion of how geodetic and geologic data north and south of the border resolve about 40 mm/yr of the 50 mm/yr plate rate on the San Andreas, San Jacinto, and Elsinore faults (north of the border) and the Cerro Prieto and Ballenas faults (south of the border). Text revised to clarify basis for tarqet slip rates. Lines deleted as part of this paragraph's revision. This low slip rate did not influence the Tl Team's determination of a model slip rate. See previous responses about slip rate budget. Also, Figure 10-178 (lower panel) depicts UCERF3 fault geometries and stated geologic best estimates, which presumably apply to those same geometries. UCERF3 Cerro Prieto fault source terminates at the border. Therefore, Attachment 3, Page 39 of 53 Date Location in No. Received Report1 194 1/19/2015 Section 10.2.1.4, Page 10-7 195 1/19/2015 Section 10.2.2.1, Page 10-8 196 1/19/2015 Section 10.2.2.1, Page 10-8 197 1/19/2015 Section 10.2.2.1, Page 10-8 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision text. Also, does UCERF3 really extend the 35 mm/yr on the Cerro Prieto fault across the border? Obviously incorrect. I think I used a date of ca. 1715 in my SCEC NIA annual report last year. A SCEC report is better than an e-mail communication. Is there a better reference? These don't add up to 21,842 terminations. NIA What gives? Explanation please. Additional text to describe how to interpret the NIA rapid changes in term of numbers would be helpful. Okay, but the barrier is really at Mystic Lake, NIA which is in the middle of your combined section. The Casa Loma fault should be treated separately PVNGS SSC Additional Documentation Summary of Revisions to Report assuming that the geologic best estimates are meant to apply to UCERF3 fault source geometries, UCERF3 does not suggest the 35 mm/yr rate crosses the border. We agree that a rate of 35 mm/yr north of the volcano is incorrect. But we're simply depicting what follows from UCERF3 geometries and best estimates (which are not UCERF3 model slip rates). No change to text. This date is based on the range reported by Haaker et al., 2013, who reported 1717-1726. No change to text. Notice that there are several colored circles that overlap, in these cases, only the circle on top has the number of terminations listed. Due to this, the numbers shown add up to 20, 725 ruptures. The rest of the ruptures are there. but contained in the overlapping circles. No change to text. These points on each figure represent the number of rupture terminations at each 7.5-km-long subsection for each magnitude range. These rupture sets come directly from the results of the UCERF3 grand inversion, and are the product of a number of constraints. not all of which explicitly described in the UCERF3 report. Therefore, any attempt to explain variations in the number of rupture terminations along strike would be laraelv coniectural. No chanae to text. As currently constructed, Layer 2 in our model produces a close match to your Clark fault (we produce M7 .3 according to Hanks and Bakun, Rockwell et al., 2014 produce M7.2), and our Layer 4 produces a close match to your northern Attachment 3, Page 40 of 53 Date Location in No. Received Report1 198 1/19/2015 Section 10.2.2.1, Page 10-9 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision There is actually a large body of new data. NIA primarily contained in theses, that can be provided to the Tl Team. However, it is quite late in the game. Bottom line -the Superstition Mountains fault fails with the Coyote Creek fault, but the Coyote Creek fault also fails on its own more frequently. PVNGS SSC Additional Documentation Summary of Revisions to Report Clark fault {our M6.9 v. Rockwell et al. 2014 M6.7). The discrepancy appears to be due to the fact that our Layer 1 combines your Claremont and Casa Loma faults, producing one M7.2 fault rather than a M6.8 fault and a M6.5 fault. The effect is that our model reserves more of the available slip rate along the northern San Jacinto fault for large ruptures, rather than dividing that slip rate into M6.8 and M6.5 earthquakes. A more segmented model, as you suggest, may be supported by the paleoseismic data. In the end, the simplistic layered fault model has to incorporate paleoseismic data while accommodating along-strike variations in slip rate. all while reserving enough moment rate for characteristic magnitudes (i.e .. layer lengths) deemed reasonable by the Tl Team. This can be a real balancing act given the competing interests -for example. creating a large number of layers to honor all variations in slip rate can have the effect of reducing hazard by consuming a lot of moment in small magnitude earthquakes. But given the distance from the site, and the relatively low contribution to site hazard from this fault {based on sensitivity analyses), a relatively simple model is justified. No change to text. We didn't have these theses during model development. As such. they postdate our evaluation and integration phases. Constraints that guided the Tl Team's selection of San Jacinto fault layers described in more detail in response to comment 240. No change to text. Attachment 3, Page 41of53 Date Location in No. Received Report1 199 111912015 Section 10.2.2.1, Page 10-9 200 111912015 Section 10.2.2.1, Page 10-9 201 111912015 Section 10.2.3.1, Page 10-10 202 1/19/2015 Section 10.2.3.2, Page 10-11 203 1/19/2015 Section 10.2.3.2, Page 10-12 204 111912015 Section 10.2.3.4, Page 10-12 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision Not supported by paleoseismic data NIA May be true, but new data indicates a through-NIA going strand between the SHF and the CCF that had small rupture along it in 1968. An unpublished trench (student thesis) shows this as a recurrent Holocene fault. And the Whittier fault??? NIA Actually, what we think is happening is that the {Same) Earthquake Valley fault transfers slip from the northern Elsinore fault to the southern San Jacinto fault zone. so the rate on the southern Elsinore fault is only about 2-3 mm/yr, similar to that along the Laguna Salada fault (3 mm/y) to the south. This is reasonable -it has major restraining {Same) steps at both ends. so ruptures probably terminate in the Palomar Mtn uplift in the north, and the Vallecito-Fish Creek uplift in the south (Rockwell et al., 2013) The MRE on the Julian segment is determined NIA from trenching at Julian and Nenshaw to be about 1,700 years ago (Thorup, MS thesis) PVNGS SSC Additional Documentation Summary of Revisions to Report Is this based on the unpublished trench data mentioned in the previous comment? No change to text. Given that the model was essentially completed in June of 2014, new data available since then cannot be readily evaluated and integrated into the model. No change to text. The rupture-set model includes any rupture in the UCERF3 model in which Elsinore sections from Glen Ivy to Coyote Mountain participate. So, this set of ruptures includes a number of earthquakes that extend onto (or from) the Whittier fault as well. It simply excludes those UCERF3 events that ONLY rupture the Whittier fault. No change to text. Text added to clarify the fact that slip transfers from the Elsinore to the San Jacinto fault. Later discussion of modeled slip rates clearly indicates where the model deviates from reality, and why this approximation is necessary. Tom -did you mean Blisniuk et al., 2013? This ref has been added. This comment would apply to the treatment of the layered model, not the UCERF3 ruptures. For the layered model, we did not assign layer-specific EPR values using layer-specific slip rates and tMREs. This reflects the fact that for most lavers, paleoseismic data are not sufficient Attachment 3, Page 42 of 53 Date Location in No. Received Report1 205 1/19/2015 Section 10.2.4.2, Page 10-14 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision This is confusing. According to UCERF3 on {Same) figure 10-17, 35 mm/yr is assigned to both the Figure 10-northern Cerro Prieto fault and the Imperial 24 fault. The upper panel shows 11 mm/yr. In Figure 10-24. there is 10 mm/yr for layer Band 1 mm/yr for layer C, so it adds up. Does this model mean that the northern and southern Cerro Prieto fault segments usually rupture independently? PVNGS SSC Additional Documentation Summary of Revisions to Report to constrain a prehistoric MRE. And if we can't do it for even one layer, we have to abandon the layer-specific approach and instead apply EPR to the composite hazard of the layered model {the same way we don't apply rupture-specific EPRs to the rupture set model, since we can't get slip rate and tMRE for each rupture). This "composite" treatment of EPR for the layered model was applied to both the Elsinore and the Cerro Prieto. This treatment differs from the way the EPR was applied to the layered models of the San Andreas and San Jacinto. No change to text. Text should call out Figure 10-17 (which shows the Cerro Prieto UCERF3 mean solution rate/PVNGS target slip rate of 11 mm/yr in panel A and the UCERF3 geologic best estimate rate of 35 mm/yr in panel 8) and Figure 10-24. This should help avoid confusion regarding where various target slip rates come from. In addition, revised Figure 10-24 adds target slip rates for our layered model that had previously been missing. Important note: Geologic best estimate slip rates were developed by UCERF3 as a guide for the deformation modelers. These are not assigned to fault sources in the UCERF3 model. In fact, slip rates are not assigned, period. Slip rates are solved for by the grand inversion. The result of the grand inversion is a solution rate for each fault model (FM3.1 and FM3.2). The average of these solution rates for a given fault is the "mean solution rate". In the case of the Cerro Prieto fault, the mean solution rate is 11 mm/vr. Attachment 3, Page 43 of 53 Date Location in No. Received Report1 206 1/19/2015 Section 10.2.4.4, Page 10-15 207 1/19/2015 Section 10.2.4.4, Page April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision How can the MRE be 244 years when it N/A ruptured in 1934? We actually don't know if it didn't rupture to the border. The record is incomplete for the Imperial Valley NIA prior to the late 1800's. The penultimate Cerro PVNGS SSC Additional Documentation Summary of Revisions to Report Regarding the last question, yes, only 1 mm/yr (out of 35 available in the south, and 11 available in the north) is assigned to rupture of the entire source, from just north of the international border to the Waoner Basin. The MRE is based on a resetting event that ruptures the full fault length (or layer length, if we are calculating layer-specific EPR). In the case of the Cerro Prieto, we don't have good paleoseismic constraints on the most recent earthquake that ruptured all of layer 1, versus all of layer 2, versus all of layer 3. 1934 may have ruptured all of Layer 3 (from the Wagner Basin across the international border), but there isn't definitely evidence for this. We also can't confidently assert that 1934 ruptured all the way from the volcano offshore into the Wagner Basin (Layer 2). Given this uncertainty, we look at the entire fault length (in this case, layer 3). assign a defensible average slip rate (in this case. 35 mm/yr), and determine the youngest possible age of full-fault rupture. We consider full rupture of the fault from the international border to the Wagner Basin to be missing from the historical record. If such a rupture has occurred, it must have occurred prior to the beginning of the historic period, which we've defined as 1770. Therefore tMRE must be at least 244 years. This model decision ends up being more conservative than if we assume the 1934 earthquake was a resetting event. No chanoe to text. See response to previous comment. We don't have a sense of rupture length or displacement Attachment 3, Page 44 of 53 Date Location in No. Received Report1 10-15 208 1/19/2015 Section 10.3, Page 10-16 209 1/19/2015 Section 10.3, Page 10-17 210 1/19/2015 Section 10.3, Page 10-17 211 1/19/2015 Section 10.3, Page 10-17 212 1/19/2015 Section 10.3, Page 10-18 213 1/19/2015 Section 10.4. Page 10-19 214 1/19/2015 Section 10.4, Page 10-19 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision Prieto fault large earthquake was likely the 1855 earthquake reported in Yuma -produced mud volcanoes alonq the CPF. The earthquake mainshock nucleated on the {Same) southern Laguna Salada fault, at least as maooed. This is only true south of the Paso Inferior N/A accommodation zone. See Rockwell et al., 2014 in review, for the full slip distribution of this earthquake. Rockwell et al., 2014 in review have extended NIA the surface rupture -it is now 55 km in length. Okay, but the 2010 earthquake produced NIA mountain-side-down displacement, whereas the 1892 uplift the Sierra Caucapah. New paleoseismic results confirm a 1-2 kyr RI on the LSF, and indicate a -20 kyr RI for the Borrego fault. Hence, 2010 was a relatively rare event. In spite of only part of this rupturing with the NIA 1999 M7.1 earthquake? How does this come into play? Does the USGS {Same) have a proxy value for lntermountain West normal fault slip rates? If so I don't know about it. Holocene activity is completely independent of NIA recurrence intervals when you are dealing with such low slip rates. In fact, Holocene movement mioht be a oood deterministic factor PVNGS SSC Additional Documentation Summary of Revisions to Report for the 1855 earthquake, and therefore we can't assume it's a resetting event. Using an MRE of 1770 is more conservative. No chanqe to text. Modified to indicate that Laguna Salada also experienced rupture in 2010. This reference was not available during the Tl Team's evaluation and integration of data. No change to text. This reference was not available during the Tl Team's evaluation and integration of data. Mueller and Rockwell ( 1995) noted that 22 km was a minimum, and we state that. No change to text. We realize 2010 was a rare event, but have chosen to model the imbricate set of faults, including the Laguna Salada, as a single fault zone with a rate of 3 mm/yr. We acknowledge that individual elements. such as the 2010 rupture. have a much lower slip rate and recurrence. No change to text. Yes, this is not done to represent past ruptures, but to incorporate the spirit of UCERF3 and allow for connectivity between geometrical simple fault sections. No chanqe to text. Deleted text. The +100%/-50% uncertainty comes from WSSPC recommendations to USGS for Basin and Range normal faults, as stated in the text. Agree, we're just using the description of dePolo and Anderson (2000). No change to text. Attachment 3, Page 45 of 53 Date Location in No. Received Report1 215 1/19/2015 Section 10.4, Page 10-19 216 1/19/2015 Section 10.4.1, Page 10-19 217 1/19/2015 Section 10.4.1, Page 10-20 218 1/19/2015 Section 10.4.1, Page 10-20 219 1/19/2015 Table 10-3 220 1/19/2015 Table 10-3 221 1/19/2015 Table 10-3 222 1/19/2015 Table 10-3 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision for non-activity in the future with SRs of 0.01 mm/vr This has not been explained Section 8.3.3, Page 8-16 The scarp may degrade, but the fault isn't (Same) going to retreat that far unless its bedrock tip is down that far too. It's more likely a basinward reactivation of a lower angle Neogene range front fault. Why so high on the average? If this was an (Same) average, the scarp should be better preserved for a longer distance. It makes more sense that this was max displacement and that the scarp height was much lower along strike to the N and S. This scarp is so far from the range front that it (Same) doesn't even fit that category. 306 or 360? 4590/15 = 360 N/A How do you get an M8 out of a fault area of NIA 4590 square kms? Using Mw=4+LogA gives an M7.66. If I invert for slip and use 4590 square kms (which implies a 360 km rupture length for 15 km of seismogenic crust}, I need 9 m average displacement for the entire 360 km Using Leonard's equation {or Wells and NIA Coppersmith), I get an M7.9 for this fault area. Typical scaling requires about 10,000 square kms for an M8 Should state here that this is NOT based on Throughout PVNGS SSC Additional Documentation Summary of Revisions to Report Definition of the censored instrumental regression from Stirling et al. (2002) provided now in Chapter 8. We agree, we're just relaying the description of the Sand Tank fault from Demsey and Pearthree (1990). Text also clarified. Yes, in response to earlier discussions with the PPRP, the values of 0.8 and 0.2 had been reversed. This is the way the model was run, but the text had not been updated. Thank you for catching this, text revised. Text added to acknowledge the possibility that the Sand Tank fault may not belong to this cateqorv. 306 km taken from length of UCERF3 section, 15 km taken from central seismogenic thickness value for SCABA. 306"'15 = 4590 sqkm. No change to text. Hanks and Bakun (2008) regression is used, 3.07 + 4/3 LogA. No change to text. Hanks and Bakun (2008) regression is used, 3.07 + 4/3 LogA. No change to text. Text revisions and figure revisions should now Attachment 3, Page 46 of 53 Date Location in No. Received Report1 223 2/17/2015 Section 10.2, Page 10-3 224 2/17/2015 Section 10.2.3.4, Page 10-13 225 2/20/2015 Section 10.2, Page 10-4 226 2/20/2015 Section 10.2, Page 10-4 227 2/20/2015 Section 10.2.1.2, Page 10-7 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision UCERF3, as the rest are. Chapter 10. Grand inversion still not defined or explained. (Same) Comment wasn't addressed in previous round (Same) of revisions. This section says must have therefore occurred before ... 1770, which makes the tMRE a minimum not an average. See line 594 = average minimum tMRE value of 244 years States that there is no dependency of slip rate (Same) branches, whereas the preceding sentences look like there is a dependency. Please clarify. "a weight of 1.0." Will this capture the body and NIA range of the CBR? Please elaborate. 3 mm/yr is less than 10% -not 10-15% as N/A stated PVNGS SSC Additional Documentation Summary of Revisions to Report make it clear that the 11 mm/yr target north of the volcano comes from the solution mean, and that this reduction from the geologic best estimate is based on the overlap of the Cerro Prieto and Imperial faults. A brief definition was provided in the previous round of revisions, but more detail has now been added. ">"was previously added to indicate minimum. This has been deleted and replaced with the word "minimum". "Average minimum used to indicate that this MRE value may not be the minimum for all layers -some layers may have a more recent MRE, but since the MRE for all layers isn't known, a slip rate and MRE representative of the full geometry (on averaoe) is applied. Clarifying text added. Dependency within a given layered fault source (i.e., all layers within the San Andreas are dependent), but not between different layered fault sources (i.e., dependency between San Andreas layers has nothing to do with what the San Jacinto layers are doing). As discussion in Section 8.3.3 and summarized in this paragraph, the range of magnitudes produced by the California strike-slip regressions is less than the aleatory uncertainty applied later in the recurrence calculation. Therefore, the Tl Team felt it was appropriate to make the simplification of using a single regression for these faults sources. No change to text. 3 mm/yr is 9% of 34 mm/yr (total available to the north) and 15% of 20 mm/yr (total available to the south). Therefore, we are takino Attachment 3, Page 47 of 53 Date Location in No. Received Report1 228 2/20/2015 Section 10.2.2.4, Page 10-11 229 2/20/2015 Section 10.2.3.4, Page 10-13 230 2/20/2015 Section 10.2.4.3, Page 10-15 231 2/20/2015 Section 10.2.4.4, Page 10-16 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision Please justify the use of 10 mm/yr in NIA calculation of the EPR distribution. as the slip rate is closer to 13 mm/yr. What effect does this have on hazard? The MRE for the Julian segment was NIA estimated at 1700 years ago (Thorup MS thesis)-will this affect hazard? Also, in the next paragraph, the tMRE is 244 -in actuality, the MRE has been determined for all segments of the Elsinore fault zone. Justify using 14 km-thick crust. The 2010 NIA earthquake ruptured only to about 12 km, and the heat flow is higher along the Cerro Prieto fault. This seems a bit deeo. Didn't the 1934 rupture essentially reset the N/A Cerro Prieto fault? Or is this for a full-fault rupture? PVNGS SSC Additional Documentation Summary of Revisions to Report "approximately" 10-15% of the slip rate budget available and applying it to full fault ruptures. No chanae to text. When we were first experimenting with EPR, we found that the results were only sensitive to order of magnitude changes in slip rate. Since that time, we've further observed that the addition of EPR to our fault sources is not hazard significant (Figure 11-24). No change to text. Regarding the last point-individual section M REs would only be useful if they provided a 1 : 1 geometric match to all fault layers. But since our layers represent both single sections. multiple sections, and the full fault, we would need MRE for each one of those geometries. Lacking those data, we decided to calculate a single EPR distribution based on the average fault slip rate and minimum MRE. and apply that EPR to the hazard of all layers. Regarding the first point -due to the potential for missed events (as discussed in UCERF2, appendix F). we decided to default to our historical records date of 1770. Since the application of EPR has been shown to be insignificant to hazard, and the Elsinore is a low-hazard contributor anyway. this will not affect hazard. No change to text. Every fault is modeled using the median seismogenic thickness of the host areal source. In this case, the median seismogenic thickness of the host GULF is 14 km. No chanoe to text. The 1934 rupture may have reset the fault from the international border to the Wagner basin. But given the uncertainty, we defaulted to an older Attachment 3, Page 48 of 53 Date Location in No. Received Report1 232 2/20/2015 Section 10.3, Page 10-17 233 2/20/2015 Figure 10-5 234 2/20/2015 Figure 10-6 235 2/20/2015 Figure 10-8 236 2/20/2015 Table 10-2 237 2/20/2015 Table 10-3 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision Add the Paso Superior fault to the list of faults {Same) that ruptured in 2010. What does "no" mean for the resetting MRE? NIA 14 mm/yr is used on page 10-2 -I am still not N/A clear as to why the tMRE uses a rate of 10 mm/yr The 35 mm/yr section of the CPR was reset in NIA 1934 -this seems to be an issue for tMRE Doesn't the 1887 rupture source fault have a NIA name? Does it matter whether the strike-slip faults NIA really have a 90 degree dip? The San Andreas fault is not 90 degrees for much of these sections PVNGS SSC Additional Documentation Summary of Revisions to Report MRE, which is more conservative with respect to hazard. No change to text. Text discussing the El Mayor-Cucapah earthquake revised as suggested. It means that the MRE used in the EPR calculation for the San Andreas UCERF3 rupture set did not reset the full length of this fault source (San Bernardino South to Imperial). No change to text. As discussed above, EPR was observed to only be significant to order of magnitude changes in slip rate. In hindsight, we could have made this 14 mm/yr to honor the geologic slip rate data. But we know that application of EPR to all of our layered and UCERF3 rupture set faults is insignificant to hazard. No change to text. The 35 mm/yr section was reset. But the short section to the north, and layer combining these sections, may not have been. As discussed above for the Elsinore fault. when lacking MREs for every layer in a given layered model, a single EPR value using a slip rate and MRE representative of the full geometry is applied to the hazard of all layers. No change to text. Yes. but since it's been called both the Pitaycachi rupture {which is incorrect since there are 2 other faults) and the Sonoran rupture (which is the kind of terminology for fault sources we seek to avoid), we call it the 1887 rupture source. No change to text. Given the distance from the site. fault dip doesn't appreciably affect source to site distance. No change to text. Attachment 3, Page 49 of 53 Date Location in No. Received Report1 238 2/20/2015 Figure 10-10 239 2/20/2015 Figure 10-18 240 2/20/2015 Figure 10-20 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision Does UCERF3 not list the San Gorgonio Pass NIA sites by Yule et al? The Imperial fault sites? Lute Ridge? Is this the Clark Lake site? Did NIA UCERF3 really list this as Lute Ridge? Panel (e) is not supported by any data I know NIA of .... PVNGS SSC Additional Documentation Summary of Revisions to Report There is a Cabazon site by Ramzan and Yule (2011) on "San Gorgonio Pass" listed in UCERF3 Appendix G. However we did not include this fault in our model. It is a dead end that branches off of the San Andreas west of "San Andreas fault -San Gorgonio Pass-Garnet Hill", with nucleation rates that are at least an order of magnitude smaller than the rest of the fault. No change to text. There are no paleoseismic sites for the Imperial fault in UCERF3 Appendix G. Lute Ridge is the name of the only paleoseismic site on the San Jacinto (Clark) fault in UCERF3, coming from Salisbury et al. (2012). No change to text. Panel (e) shows layers 4 and 7 of the layered model of the San Jacinto fault source. Layer 4 is an attempt to model the 1918 Anza-only ruptures. Layer 7 models the UCERF3 Superstition Mountain section as rupturing alone. We assume you are referring to Layer 7. Point taken. This is one of those instances where our layered model was more influenced by changes in slip rate along strike, and less influenced by paleoseismic history. UCERF3 Appendix B provides identical geologic best estimate slip rates for Coyote Creek and Borrego (5 mm/yr). whereas Superstition Mountain has a slip rate of 7 mm/yr. In the end, both our segmented model and the segmentation implied by the paleoseismic record are superseded by the connected ruptures produced by UCERF3 (given a weight of 0.8) in Attachment 3, Page 50 of 53 Date Location in No. Received Report1 241 2/20/2015 Section 11.3, Page 11-2 242 2/20/2015 Section 11.3.1, Paqe 11-3 243 2/20/2015 Section 11.3.1, Page 11-3 244 2/20/2015 Section 11.3.2, Page 11-4 245 2/20/2015 Section 11.3.2, Par.ie 11-4 246 2/20/2015 Section 11.4.3, Page 11-6 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision Chapter 11 Please explain why these simplifications are (Same) used (later in this section the phrase "for expediency" is used. This is far from convincing. Please develop a well-stated strategy for using and defending the use of simplifications. Give a sample distance to set the frame of (Same) reference. Could it be 100 km? Please explain and justify what "minor" NIA means-less than?? This geographical area needs to be defined (Same) with an accompanying map. I don't think this has been defined previously. Later in this paragraph there are references to maps in other sections. I suggest providing a map her that shows "greater AZ." and what seismic sources it includes. Define Rrup (Same) It's one of two, how can it be the host (only) NIA PVNGS SSC Additional Documentation Summary of Revisions to Report our SSC model. No chanae to text. Text added to provide justification from NUREG 2117 for simplifying logic trees. The shortest distance between the site and non-host areal sources specified as ">80 km". We intended to keep this discussion general and not get into percent contributions, since these are preliminary results for reference rock (not site-specific Palo Verde rock or soil conditions). Figure 11-15 shows hazard curves for all areal sources with respect to mean total hazard. This figure is not cited at this point in the text, however, to maintain logical order of presentation of oreliminarv results. No change to text. Text rewritten with bullet points specifying those sources belonging to each SWUS GMC region, with figure callouts. Definition added. In each areal source alternative (Two-zone and Seismotectonic), there is one areal source hosting the PVNGS site. In the Two-zone alternative, it's the East source. In the Seismotectonic alternative, it's the SBR source. Attachment 3, Page 51 of 53 Date Location in No. Received Report1 247 2/20/2015 Section 11.4.10, Page 11-7 248 2/17/2015 Page 13-1, "Active fault" 249 2/17/2015 Page 13-1, "Active fault" 250 Page D-27, ANSS Earthquake Catalog April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision How about a concluding sentence or Section paragraph that synthesized the important 11.5 elements of the analysis of this chapter. As now written, you are closing with a whimper. Chapter 12 (No technical comments from the PPRP) Chapter 13 Wasatch has no clear association with (Same) earthquakes but has a robust Holocene history. I don't agree. Most faults called active in the (Same) US are Holocene. Some people use the terms Quaternary and Quaternary-active. Appendix A (No technical comments from the PPRP) Appendix B (No technical comments from the PPRP) AppendixC (No technical comments from the PPRP) Appendix D This date does not seem consistent with the (Same) download date-please explain/correct. PVNGS SSC Additional Documentation Summary of Revisions to Report These two sources also happen to be the most dominant contributors to hazard from areal sources, which is what this section is stating. No chanae to text. Section 11.5 "Summary" added. Phrase "clear association with earthquakes" removed. Sentence "Quaternary faults are generally considered to be active" removed. The ANSS Earthquake catalog was downloaded at several different dates throughout the course of the project. The documentation in Appendix D is now corrected to reflect the most recent download date. Attachment 3, Page 52 of 53 Date Location in No. Received Report1 April 17, 2015 COMMENT-RESPONSE LOG PALO VERDE SSC REPORT Location of PPRP Comment Comment Revision Appendix E (No technical comments from the PPRP) PVNGS SSC Additional Documentation Summary of Revisions to Report Attachment 3, Page 53 of 53

1* ,* Time 1:00-1:15 1:15-1:45 1 :45 -3:45 3:45 -4:05 4:05 -4:20 4:20 -5:00 Topic Introductions Overview of R2. 1 Seismic -Discussion on meeting goals and expected outcome -General Background on 50.54(1) and NTTF 2.1 Seismic -Introduction of seismic hazard PSHA methods and Senior Seismic Ha7ard Analysis Committee (SSHAC) process Presentation of Seismic Reevaluation Report, Overview -SSHAC Activities -Seismic Sources -Ground Motion Model -Interim Actions or Evaluations -Technical Focus Areas and Discussions Planned Break NRC Meeting Wrap up -Technical wrap-up, review focus area, and next steps Public Questions or Comments Speaker NRC!PG&E Co. NRC Jearl Strickland Norm Abrahamson Norm Abrahamson Norm Abrahamson Nozar Jahangir All NRC Public/NRG 2 Safety is and always will be a core value for PG&E and Diablo Canyon Power Plant.

• New and extensive seismic hazard re-evaluation continues to show plant can safely withstand earthquakes.
• Seismic re-evaluation was performed with independent experts in a transparent and open public process.
• Using new regulatory guidance, the latest scientific methodologies and site-specific information, the analysis demonstrates the plant's earthquake design is appropriate and safe.
• PG&E maintains a Long Term Seismic Program (L TSP) for Diablo Canyon, a unique program in the industry that continually assesses seismic safety.
• Safety commitment will continue to be reflected through ongoing seismic study. 3 LTSP Update I Data Compilation and Collection .-------. .-------. Geophysics Geology, Seismicity (AB 1632) (PG&EJ Interpretation Interpretation SSHAC Process Evaluation Integration PSHAU-1 Ground Motion Studies (PEER, SCEC) Published Reports / 4 *Update the seismic source characterization (SSC) and ground motion characterization (GMC) models for use in an updated specific probabilistic seismic hazard assessment (PSHA) *Develop a methodology for obtaining reproducible, stable estimates of probabilistic seismic hazard at a site, including explicit quantification of uncertainty. *SSHAC guidelines are summarized in NRC documents NUREG/CR-6372 and NUREG-2117. *DCPP incorporated new geophysical data into the SSC model, acquired as part of the State mandated AB1632 studies.

SSC/GMC Workshop 1 -Nov. 29 -Dec. 1, 2011 SWUS GMC Workshop 1 -Mar. 19 -21, 2013

• Significant Issues, Available Data, Data Needs
• Included Resource Expert Presentations
• Following March 12. 2012 50.54(f) letter, split SSC and GMC into separate SSHAC studies. . SSC Workshop 2 -Nov. 6 -8, 2012 SWUS GMC Workshop 2 -Oct 22 -24, 2013
• Alternative Models and Proponent Interpretations
• Included Proponent and Resource Expert Presentations SSC Workshop 3 -Mar. 25 -27, 2014 SWUS GMC Workshop 3 -Mar 10-12, 2014
• Preliminary Model and Hazard Sensitivity
• Included Proponent Expert Presentations 5

. § f. \J t:l "' "' .. . .... , ... '* .. * . . . * . *, ', '*. ocrr o. 6 LEGEN "'008 rHa,oebec D k 201)) ty 1987 10 .. Se1sm1c1 D 8C-99 -* 0 0 -1 :} 10 c -It 9 D Z0-39

• f .
• 120-1).9
• D 40-s3 c. .
• 140. D 6.o. *9 1* ,* CCCSIP Study (PG&E)
• Offshore 2D/3D Seismic-Reflection Data
• Onshore 2D/3D Seismic-Reflection Data
• Updated Geologic Map Data Relocated Seismicity Catalog (J. Hardebeck, USGS) Offshore 20 Seismic-Reflection Data (S. Johnson, USGS) Offshore high-resolution bathymetry data (R. Kvitek, CSUMB and S. Johnson, USGS) GPS Velocity Field (J. Murray, USGS and C. DeMets, UW) 7 8 New Models
• Uniform California Earthquake Rupture Forecast, Version 3 (UCERF3) -USGS, CGS, SCEC
• Offshore Hosgri fault slip rates New Methods
• Rupture Sources: Incorporate earthquake ruptures that involve multiple faults
• Composite earthquake magnitude-frequency distributions (Wooddell et al, 2015)
• Fault geometry models that correlate geometric uncertainty
• Capture time-dependent behavior and uncertainties
• Virtual faults within the host areal source zone 8 1* ,* Primary fault sources
• Contribute most of the hazard
• Hosgri, Los Osos, San Luis Bay, Shoreline faults Connected fault sources
• Can link (rupture with) Primary fault sources
• E.g., San Gregorio, San Simeon, Wilmar Avenue, Oceano faults Regional fault source
• San Andreas
• UCERF3 faults
• Additional non-UCERF3 faults Areal Source Zones
• Regional source zone
• Vicinity source zone
• Local source zone 9 I' .1" '" , Virtual faults capture uncertainty in location, dip, sense of slip for other known and possible faults a 2 a . ,,11.1* \ "11" ""-\ '\ ' ' ' ' " ' Vicinity source zone boundary *121.1" -tit* 10 *12'!.t" -120 ,. \ *1206' . \.' \ '-.... \ 'I \ \ .. \ ;II \ ' '* "* "*.:.: ** ... *120.9" :-.: *120.6' NRG SSC Topic 1: Summarize the key data used to constrain the slip rate of the Hosgri fault, including associated uncertainties.
• Four slip rate sites
• Three new sites offshore
• Uncertainties developed for each site
• Sites are weighted for final uncertainty + ..... ().. t-. \ "' \ I \ \ \ 'f' \ \ \ \I ,,.. \ \ *lll"t' **. *Fr ,'\ncisco " . "W 11 IC' ,, . . . :-J: ..... . ... ! .. . . . ... 20 ... : + . . . . : ... *O . .., :"' . . . . . . . . \ *4 \ De \ \ \ \ \ \ . . . . <:Cayucos LosOsos D DCPP
• San Luis Figure extent EXPLANATION -*** * *
• r .,, 11* *: :. * .-*-,., .. 11 I:" ;J ... 1 ::;, :. *1.:.1 I ,._ ! ... *, 'u : : ' .. : ** :. * * * .... 1;1 ., : ... , , ,, ., , .... 11* ., I *. .-*' .I l,o*l 1'1,1 .-,.-.: ., *:I-*! I' : ** * l ., .' *** '1 ,. * :;,* ., ;.. *-rr ,,. I' Ch*nnel Oepth '**'*lll*IJ * *** *'; .\*.,.**I* '***+* ! '*' ,*.,: :1r*.-; rro I r:ro ;1.*rn'.*. *,h;11):t**. * *r*** * *r .-:* 1 .... ; * , ...** ** ;n ** 11' 1*,1*; ir. *!*r* r11.-*n **1 *' ,* * : ,, ,'.* ; 'r .. , '.l1* : * ,11* ' ;,.* II Lo;**: *:** .* 1h* *11. * ...... ,. " I: .. * -* .. , *,,.,,, :-1* .. , l::*I* .* 1 * .* ,., .. .,.,:I ... I ... , .. 1 ** *.,*J' * *. , ... I ,.* , . ._.,:.*no*.** fn1 1*.o,*11 ':: *:*. *. *. : ..... . ........ 11 ** '.\ ... : .. ..... J '.:It*:, .. :, '*, **. *' ,*' *:. *1 ,.<'!.'*.**.: :1 .. *r: *;*: .. **111. '.,1:,J ;.111: '.*II'.* llf .. **t .. *,:,; :.C:DC ... ,,, soo N A c ..io: Estero Bay: Piercing Point DBw-Ee1-De Separation and Uncertainty OCPP SSC REPORT Pacific Gas and Electric Company Figure 8-25 ... 12 1* ,* (a) Offset PDF 0.12 0.10 0.08 >-ii 0.06 0 ... a.. 0.04 0.02 0.00 0 13 Documentation of Offset Uncertainty (b) Justification for offset PDF West Strand Value Offset (m) Basis South margin or the shallo"N West strand off set Min. 450 channel-like feature and the limits of uncertainty in the projection of Channel Ee1 -East strand offset Preferred 770 Range estimated from direct projection of Channel Ee1 and Preferred 1,050 margins of shallow channel-like feature west of fault 10001 North margin of the deep Max. 1,730 channel-like feature and the limits of uncertainty in the projection of Channel Ee1 East Strand Value Offset (m) Basis Min. 200 Estimated from incorporating uncertainty in projections Preferred 230 Range estimated from the .,,----direct projection of Channel Ee1 .,.,... --and De thalwegs -Preferred 290 .,.,... -; -250 500 750 1.000 1.250 1,500 1,750 Estimated from incorporating Max. 320 uncertainty in projections Offset (m) 1* ,* (c) Age PDF 0.010 0.008 :c 0.006 Ill .Q e A. 0.004 0.002 0000 0 250 14 Documentation of Age Uncertainty (d) Justification for Age PDF Value Age (ka) Basis Min 340 MIS 10: youngest age of overlying unconformity Pref. 535 MIS 14; 2:5 transgressive Low End uncon. in strata above channel Preferred 630 MIS 16: probable end of MPT MIS 20; shelf progradation Preferred 800 deeper sea level during late stage MPT Pref. 1,000 High end of uncertainty in High End shelf progadation Max. age of NTN Max. 2,500 unconformity (PG&E. 2014 Chapter 3) 500 750 1.000 1250 1.500 1.750 2.000 2.250 2,500 Age (ka) 1* ,-15 Slip Rate CDF for Estero Bay Site (e) Slip Rate CDF (f) Summary Statistics 0.9 0.8 Cumulative Slip Rate Probability (mm/yr) :>. 0.7 -0.05 0.8 :c 0.1 1.0 !ti 0.6 .c 0 0.2 1.2 ... a.. Q.) 0.5 0.5 1.7 > :;::::; m 0.8 2.2 ::I 0.4 E 0.9 2.6 ::I u 0.3 0.95 2.9 Minimum 0.3 0.2 Maximum 5.3 0.1 Mean 1.7 0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 Slip Rate (mm/yr) 1* ,-Weighting of Four Study Sites CBR of TOI (in mm/yr): Center: 1.7 (wtd. mean) Body: 0.8 to 2.6 ( 1 0°/o, 90°/o) Range: 0.4 to 3.4 (1°/o, 99°/o) >. ..c C'G ..c a.. QI .!!! :I E :I (.) 0.9 0.8 0.7 0.6 0.5 0.4 0.3 I 0.2 I 0.1 I / 0 0.0 0.5 1.0 1.5 2.0 I Slip Rate CDF I I I 2.5 I I I I I 3.0 Slip Rate (mm/yr) / 16 -San Simeon I Oso Terrace Weight (0.3] --Point Estero Cross-Hosgri slope Weight [0.2] Estero Bay submarine channel Weight (0.3] Point Sal Channel F Weight [0.2] -Weighted Hosgri slip rate 3.5 4.0 4.5 5.0 5.5 17 NRC SSC Topic 2: Clarify how elements of the thrust! reverse interpretation for the San Luis Range Thrust are incorporated into the SSC. *San Luis Range thrust model proposes that the Irish Hills are uplifted by a northeast-dipping thrust fault *SSC model incorporates this model as one of three alternatives of uplifting the Irish Hills 3 for Hosgri; 3 for San Luis-Pismo Block Alternative Fault Models: 18
• Describe the fault geometry for each tectonic model in a correlated way
• Dip variability is achieved through the differences between tectonic models NRC SSC Topic 3: Clarify how the rupture models are derived from the fault source geometry models. Fault Geometry Models (FGMs) describe the fault locations, dips, and senses of slip Rupture Models describe the alternative locations on the FGMs where maximum earthquake ruptures and smaller, floating ruptures occur.
• Represents aleatory variability in how earthquakes rupture the fault network
• Allows single-and multi-fault rupture in a standard, forward model
• Rupture models include sufficient rupture sources such that the range of alternative types of ruptures are sampled for adequate source and ground motion variability 19 I' '" *-Rupture Models Allow multi-fault ruptures New composite frequency distribution (a) "20 (b)M,.., N A 0 10 20 -mo w "" 0 10 20 .,,,., *. -M l""iJi Magnitude I' '" *-NRC SSC Topic 4: Summarize the Methodology Used to Define the Equivalent Poisson Rates. Motivation: Non-Poisson Recurrence Behavior is Likely
• In some cases, paleoseismic recurrence records are inconsistent with a Poisson process
• Renewal process includes intuitive physics (elastic strain accumulation and release)
• Simple models available that simulate renewal-type behavior (a) (b) 08 0.6 04 02 0 0 0.5 . 21 Exponential .* / .. *. ;;;,.. . .*' .*',1' ' .. ** ... * . ,.****.: ...... . 1 2 3 4 Normalized time Lognormal, a= 0.6 2 3 4 Normalized time 22 Methodology: 1. Lognormal model for recurrence (also BPT, Conditional Probability Ratio Weibull) 2. Requires estimates of long-term mean (LTM), coefficient of variation (CV), and time since the 2 .... .. ...... -. most recent event (Tmre)
• CV range from global paleoseismic data (mostly California) *
• Tmin constraint on Tmre from historical record (SLO Mission) LTM from slip rate and simple slip/event model 3. For each CV and slip rate, model considers joint probabilities of correct LTM and Tm re 4. 3-pt. approximation of resulting CDF is used in the logic tree for an EPR c.. ,.:* . z ,...* __ en .* .,_,7-------. -. ----*-.. _ . o ,,, .. _ --2 1 ;< / ./ ..... *:-*.-,._. ..... * ........... . CL , *---. ---* ----() I / ....... : -. *:---*-*-*--*------* ,*' / ... ....... .* 0 2 Normalized time EXPLANATION --c;=Q4 ---o*Ot. --o=CS ---o=l 3 4 IC' ,, Use of survivor function to constrain L TM, Tmre joint probability (CV:0.6 shown) (a) PDF 1:;o i'i 2x10<* --ltm:500 ---ltm: 1.000 1.5x10° * * * * * * --* * --* * ... * * .. * .. *
• ltm: 2.000 2l 1 x1 o*l e a.. 0.5x1 o<* I I .* ...... ... 0 1tc.......:__ __ 0 2,000 4.000 Time since MRE (c) 30-Year Conditional Probability 0.2 a.. 0 015 0.1 0.05 0 0 ,, ' . . . ' . . ' 2.000 --ltm:500 -pois500 ---ltm 1000 -pois 1,000 * * * * * *
• ltm: 2,000 -pois2,000 4.000 Time since MRE (b) Survivor Function .q .0 ro .0 e a.. \ ., .. \ 0.8 .. \. 0.6 ... \ 0.4 ... 0.2 0 0 . *., .. 2.000 4.000 Time since MRE . . '. (d) 30-Year Conditional Probability Ratio to Poisson 2 Q 1ii er :.0 e 0.. (;j 1 . . ,. . I , : ., .'. ..... c 0 :g 0.5 I.; ............................... . c 0 (.) 0 0 I : I : 2.000 4.000 Time to MRE 23

(/) ro Q} 1* ,* 3,000 ..... . 2.000 1.000 . 1,000 CP Ratio, LN RI Model, CV: 0.6 2.000 3,000 4.000 Time since MRE (years) . . . co \. 0.81 0.27 5,000 Note: Contours are the ratio of time-dependent rate to time-independent rate. The long-term mean distribution is uniform on the range shown. 24 Joint L TM-tMRE Weighting Probability 4000 . :::oJ 3.000 4.::co Time since MRE (years; EPR Logic Tree, Hosgri fault 1.9 [0.25] 1.3 [O.S] 0.3 [0.25] Reference rock ground motion model (SSHAC GMC)

• Median ground motion
• Aleatory Variability Site Amplification
• How the ground motion at the control point differs from the reference rock ground motion Capture Uncertainties in each part
• Epistemic uncertainties 25 26 Data
• NGA-W2 strong motion data set (PEER)
• European strong motion data set (RESORSE)
• Finite-fault simulations close to large earthquakes (SCEC) Models
• Median GMPE: NGA-W2 GMPEs
• Median GMPE: European and Japanese GMPEs
• Aleatory variability: Mixture model Methods
• Sammons map approach to develop weights for GMPEs
• Additional epistemic uncertainty added to all GMPEs
• Included comparisons with empirical data and finite-fault simulations (SCEC) as part of the evaluation of the weights
• Single-station sigma approach
• Improved treatment of uncertainty for empirical DCPP site terms 27 ' "'C ..... 0.001 ro N ' ' ro I ro ::::J c:: c:: 0.0001 mean ( 5 Hz) \ \ <( ' 5th 15th \ \ 0.00001 50th ---85th \ l \ 95th l \ l 0.000001 0.01 0.1 1 10 Spectral Ace (g) 1* ,-0.1 DCPP: 10-4, S Hz CDO onxIXIDCIDO 0 0 0 00 GM Ratio (Sens/Bue) 0 0 0 0 0 000 000 en:> 00 0 * *
• 0 0 0 1 *_,Common-Form Models *:*Total Sigma *_;Dataset _*Tau * .' PhiSS Dataset *.*Phi Eps. CA *_*Phi Eps. Global *;Mixture-Low :_-,Mixture-High *:.*Phi SS Mag-Dep.
• _
• HW Models *_*HWModel 13 *
• HW Model 23 *_;Directivity Model S *:1 Directivity Model 13 * ; Directivity Model 23 28 29 NRC GMC Topic 1: Provide additional detail in the criterion used for the selection of candidate Ground Motion Prediction Equations (GMPEs) for development of the common form median ground motion models for DCPP. Specifically, please elaborate on the basis for including GMPEs based on data sets other than NGA West-2.

NGA-W2 NGA-W2 NGA-W2 NGA-W2 NGA-W2 Europe & ME Abrahamson et al. (2014), referred to as ASK14 Boore et al. (2014), referred to as BSSA 14 Campbell and Bozorgnia (2014) , referred to as CB14 Chiou and Youngs (2014), referred to as CY14 Idriss (2014), referred to as ld14 Akkar et al. (2014a, 2014b), referred to as AS B 14 Japan & CA Zhao et al. (2006), referred to as ZH06 Japan & CA Tl Team implementation of Zhao and Lu (2011 ), referred to as ZL 11 30 Consider all modern GMPEs from active crustal regions *Assumes that the magnitude and distance scaling in active crustal regions is similar around the world 31

• Selected GMPEs had to meet 7 criteria (SWUS, section 5.5.2) -Most recent version -Not an adjustment of another model -Functional form extrapolates in a reasonable manner -Do not combine data from active crustal and subduction earthquakes -Not just a research tool -Not developed for a very small region -Peer reviewed
• The objective is to capture the uncertainty
• GMPEs from other regions may provide alternative credible scaling for ground motions in CA
• Early feedback from PPRP recommended that we not limit the GMPEs to NGA models because there models may not capture the full range of uncertainty
• Some of the large magnitude data in the non-NGA GMPEs are contained in the NGA data set, so there is overlap, but also different modeling approaches used
• The weights for the final models are developed considering how well the models fit the NGA data 32 NRC GMC Topic 2: Provide additional detail on the development of the common functional form used to fit the candidate GMPEs. Specifically, please discuss how model parameters such as depth to Vs equals to 1 kmls and 2.5 kmls (which are present in some of the candidate GMPEs) are accounted for in the functional form. 33 The common-form models
• Developed for a single reference rock condition of VS30= 760 mis
• Footwall side only to keep the functional form simple
• Hanging-wall effects added to the common-form model The other site parameters, Z1 .0 and Z2.5, are set to their default values for VS30=760 mis
• Basin depth is not a significant issue for soft-rock sites 34 35 NRC GMC Topic 3: Provide additional detail on the approach for weighting the selected common form models as well as the criteria used to verify the physicality of the final model. 2000 models generated to fill in the space of possible GMPEs
• Sampled the covariance of the coefficients
• Treats the correlations of the coefficients Non-physical models *Tails of distributions of coefficients may lead to sampled models that are "unphysical"
• Defined as models for which the magnitude or distance scaling is not monotonically increasing (M) or decreasing (R)

I' '" *-,........, (\,( Cl) --1 0.5 <( C) a_ 0.2 ./ 5_0

• BSSA14 D CB14 5.5 6_0 Magnitude RJs = 30_ strike-slip V S3D = 760m/S 6.5 7.0 36 Measure the Standard Deviation of Difference in GMPEs for a Range of M,R 1* ,* =! :i .5 10 0.0 -0.5 th .... 5 .5 T = 0_01 NGAW2oc-MED 1.0 -0.5 0 ***95-T = 0.01 SI Moc-MED _._.:::--.., "l ID T = 0.01 NGAW2oc-Me.o 0.$ "' O.D .s 1.ol1-=-o -* In unrts ---1.0 r -1 . 5 0 -0. 5 0 t. 1*0 In units
• 0_5 1.0 1_5 37 -. I ..

APPROACH DATASET 0.75 NGAW2£<*MH* 0.67 Data Comparison 0.25 0.33 ---GMPE Prior WEIGHT STATISTIC 0.60 R .d I es1 ua 0.40 --.... Likelihood 1.0 ------Residuals 0 ---Likelihood 38 0.01 0.001 0.0001 le OS IC' ,, Hazard Curve: 5Hz . . . . . . . . . . . . . . . . . . . . . . ."'**,,, '>**. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ... ... ****. .... ..... ----........ ---....... -. ---: : .... <_*-.... -> ....... -:---MOl M03 MOS M06 M07 M12 M13 Ml4 MlS M16 M17 M18 M20 M22 M23 .................. **********************'\\************* \ 1\\ ........ . '\ \\ M24 . . \\ "* M25 \\ M26 \.\ M27 '* M28 \\ M29 . M30 *\\ M31 . . . . . . . . . . . . . . . . Mean Model ....... '*l A SK : , Al4 *********** <!. CB14

• l \\. CY14 -* ld14 ....... \ \ > ZH06 ********* * ** * -* * * * * * * * * * * * * * * * * *. * * * . \ Zlll *********** : 0.1 PSA{g) 0.01 0.001 0.0001 le OS 0.1 Hazard Curve: 0.5Hz .. \ **-...... . PSA{g) MOl M03 MOS M06 M07 MOS M10 M12 M13 M14 MlS Ml6 M17 M18 M19 M20 M21 M22 M23 M24 M2S M26 M27 M28 M29 M30 M31 39 Meao Model ........ ASB14 ASK14 BSSA14 .......... . CB14
• CY14 ld14 ....... .. ZH06 --***--** ZL11 ......... .. GK14
• 10 NRC GMC Topic 4: Provide additional detail on how the continuous distribution for total sigma was developed by combining the between-event and within-event aleatory variabilities. 40 Model M-Dependent 1.0 M-lndependent 0.0 Aleatory Vari ab i I ity High (95°/o pe1*centile) Oa2 Centl'al O .. fi Low (5°/o pe1*centile) 0 .. 2 41
• -1 * ' 'it 42 Dataset Model I I <t>ss Estimates Directivity Aleatory Adjustment Distribution Form 4>ss-CA*l 0.5 High Califomia {95% percentile) Yes. Central Mixture Model 0.67 ff.2 0.0 0.8 4>ss-cA-2 European Central 0.5 4>ss-GLOBAL* RSO (J. i) 0.0 1.0 Low Global (5% percentile) No Normal 0.33 0.2 1.0 0.2 M-Dependent 0.0 Use Chi-Squared distribution for phiSSJ\2 and TauA2 For each model (branch 2) of phiSS logic tree, sample the three PhiSS values and the three tau values Develop a cumulative distribution function (CDF) 43 Average the CDF using the logic tree weights for the alternative PhiSS models (branch 2) and data sets (branch 1) Sample the total CDF at the 5th, 5Qth, and 95th fractile levels 1* ,* ::-. -:.B ro a. 2 a.. 4l =--ro ::::l E ::::l u 0 ..... (0 0 0 'V 0 N 0 0 0 0.0 44 Usinq California Model 1 Usinq California Model 2 Usinq Globa I Weighted Composite 0.2 0.4 0.6 0.8 1.0 NRC SA Topic 1: Section 2.3.2.1 of 50.54(f) Submittal states that shear modulus and damping curves are not directly applicable to DCPP since analytical modeling is not used and that non-linear site effects are implicitly included in the empirical GM,PEs for Vs30 = 760 m/sec. However the NGA West 2 data base has a limited amount of data for sites with Vs30 near 760 m/sec and for earthquake with magnitude and source to site distance similar to those dominating the hazard for DCPP. Please provide additional information on how these limitations in the NGA West 2 data base are accounted for in site response model for DCPP? 45 Nonlinear Site Response in NGA-W2 GMPEs Some GMPEs used analytical modeling for noninearity. 150 125 If) O'> c :0 100 ..... 0 (..) <1> a: 75 -0 ..... Q) .0 50 E ::J z 25 0 0 0 0 0 C\J (Y) v I 0 0 C\I 46 0 0 0 0 l{) l{) 0 0 ""'" CD ()} ""'" ' ' . ....... 0 0 0 0 I (Y) I.[) I.[) 0 .q-CD 0 O> VS30 (mis) 47 NRC SA Topic 2: Section 2.3.6 of the 50.54(f) Submittal describes the development of the site terms for DCPP. For the calculations of between-event residuals, provide additional information on the criteria used to determine the appropriate distance range(+ and-Rrup) to the sample station. Please discuss the sensitivity of this distance range on between-event residual values. Please provide an example calculation that uses site specific values to determine the values for Phi s2s including the epistemic uncertainty in the site term.

48 Non-ergodic ground-motion model InSA0bs(Mi, Loci,Sitej) ==In GMPE(Mi, Rij, VS30 j) + <5L2L1 + <5S2S1 + <5P2Pu + <5Bi0 +ow,; Estimate the combined source and path terms for each earthquake using observations from other sites (not DCPP) 49 <5S2Sj = InSA0b.JMi,Loci,Site)-InGMPE(Mi,Rij, VS30) -(<5L2L1 + + <5P2Plj )+ Sources of Uncertainty of Site Term

• Uncertainty in the Event-specific source and path term:
• Randomness of the remaining aleatory variability of the event term Two factors
• Distance range that includes the DCPP distance
• Distance range for which the residuals do not have a strong distance slope 50 1 0.5 -(/) 0 :!:: c 0 :::I *
• z ....J -. .., 1.5 1 0 0 0 cg " . . . . . . . Q)o 04 oe n. " . . '-'* -. . . v 't 00 0 0 o '-' 0 0 0 0 0 co " 0 10 100 Rupture Distance (km) 1000 51 o San Simeon * -* * *
• DCPP Mean Path & Source Term plus SE minus SE 2 1. 5 1 (j) 0.5 :!::::: c :::::; 0 z ctS :::::; :0 -1 (/) -1.5 2.5 -3 1 --00(; (fr ,... r. I(!) 0 0 hr. , -v 0 rll 0 0 IV ,.... ..... ( 0 ,..j 1,.... q, 0-_1 c r\) ,...,_ VO vo u 0 9i '-' b 0 * *
• u 0 0 .. *'-'. (ii 0 n 0. ,...... cP () 9:> 0 (} In uo 0o 0 -0 10 100 Rupture Distance (km) 1000 52 o Parkfield e DCPP -* * *
• Mean Path & Source Term plus SE minus SE 53 Computed from the standard deviation and number of recordings used to estimate the term *San Simeon: 8 recordings, Sigma= 0.68 In units
• Parkfield: 16 recordings, Sigma= 0.55 In units Epistemic uncertainty is the standard error of the mean
• Sigma I sqrt(N) 0.25 for San Simeon 0.14 for Parkfield Std Error of JS2S DCPP = NEQK L SE(Source +<Pc; i=] = 0.22 NEQK 1960 54 DCPP Seismic Design/Licensing Basis History 1985 U-1
• March 2011 *
• 1986 U-2 *June 91 Nov. 2008 *Fukushima Event. -. . . . . March 2012 1968 & 1970 83 . In operation SSER 34 AB 1632 NRC NRC Fukushima Construction Permits DVP / IDVP (Accepting L TSP) Hazard Rll 09*01 50.54F NTTF 2.1 Evaluation SFZ Seismic Update I DE/ODE j + Hogri (w/Sig. Mods.} + LTSP Study DE/DOE/ Hos+ LTSP Margin AssessmentC I 1971-1976 Off-Shore Hosgri ID/Validation 7/88 1984 LTSP Report I Submitted 1 LTSP May91 LTSP Program License Condition Committment (Shiffer) Nov. 2008 2015 Oct.2012 Shoreline Fault \Rf RII. 12-01 I SFZ)Discovery Jan 2011 AB 1632 SFZ Final srz Seismic Report to Studies NRC Report !Sep. 2014)

DCPP was licensed prior to App. A to 10 CFR Part 100 (Introduced "OBE& SSE" terms) DE: OBE Equivalent= 0.2 g DOE: SSE equivalent = 0.4 g HE: Largest design ground motion= 0.75 g L TSP: Seismic Margin /L TSP Spectra= 0.83 g 2.5 2.0 -1.5 en -c .2 -f 1.0 (I) (J (J < 0.5 0.0 0.1 -LTSP -DE HE v r... ........ --DDE v " -HE(UFSAR) .15 ----HE (EX1rapolated) \ / I """"'11. \ I j [ 1()1 , v .\ _J /; .... , I * / \ __,/ [I 1.0 10.0 Frequency (Hz) ' " " IJ 55 .83 .75 .40 .20 100.0 GMRS Vs. 1977 HE Design u 0 0. "' 010 ' ' 'J ,lj p -GI.IRS -HE1.rS'.P.; ***HE 1 -) I ' ' --Frequency IHz) 56 GMRS Vs. L TSP Seismic Margin I -LTS' SHmc ... ' I\ I \I ...... \ \ I '\ I\ \ I I r-...... ...... -ll I/ :s :.o : .. 10 1.00 lO:l: 100 :o Frequency IHz) 57 3.0 urs b irn Margin 2.5 19 IE \ l/' ----I\ ' ,\ ) v r-... G MR s 2.0 ,/ I/ ...... \ v I ... J ' / \ "\ I * ........ 11 __/ lo.. I

• I I ,I DOE j '-1.0 0.5 0.0 0.1 1.0 10.0 100.0 Frequency (Hz.)

L TSP Licensing Background

• DCPP License condition No. 2.C.(7) required in part "PG&E shall develop and implement a program to reevaluate the seismic design bases used for the DCPP"
• Seismic reevaluation effort was titled Long Term Seismic Program (LTSP); issued in 1988 with 1991 addendums to address the LC and committed to maintain the program going forward. 58
• L TSP deliverables were Seismic Probabilistic Risk Assessment (SPRA) and Seismic Margin Assessment (SMA)
• NRC's comprehensive assessment and acceptance are documented in Supplement 34 to Safety Evaluation Report (SSER-34)
• Key Points -From SPRA; Mean Seismic Core Damage Frequency (SCDF) was calculated to be 3. 7x 1 0-5 59
• Current SCDF (including updated; data, logic model, HRA) is 2.66x10-5
• SCDF sensitivity review considering updated Hazard (with the original Fragilities) is -2.06x10-5 . The fragilities will be revised to get updated risk values. -The fragilities and HCLPF capacities are based on 5°/o damped horizontal spectral acceleration values, averaged over 3.0-8.5 Hz. (-1.94gs) -From Seismic Margin evaluation; the Lowest, High Confidence Of Low Probability of Failure (HCLPF) of SSCs was determined to be 2.62g resulting in a minimum seismic margin of 1.35. -NRG reviewed and acknowledged the significant seismic margin in SSER-34.

Expedited Seismic Evaluation Program (ESEP):

• The GMRS is recognized as beyond design basis. However there needs to be reasonable assurance of plant safety while new/updated risk evaluations are in-progress
• Developed to address where significant exceedance beyond design basis are identified in the 1-1 OHz. frequency range.
• The GMRS is effectively bounded by the 1977 HE design spectra in 1-10 Hz. Minor high frequency exceedance is well within the L TSP seismic margins and adequately considered in the SPRA analysis. Therefore there is reasonable assurance of plant safety. Spent Fuel Pool Evaluation:
• SFP structure is an integral part of the Auxiliary building, which has been designed and evaluated as a seismic Design Class I structure in accordance with the DE, DOE, HE design criteria, and considered in the SPRA (Building fragility). Therefore, there is reasonable assurance of structural integrity. DCPP will perform rapid drain down evaluation activities, as required per SPID and will reevaluate the fragilities for the Auxiliary building as part of SPRA update. 60 Proceeding with SPRA Update/Upgrade -Updating building models (3D FEA) -Updating SSI models -Developing Building FIRS -Fragility evaluation preparation -Updating/upgrading the SPRA model Next Actions -Determine Risk evaluation Prioritization (NRC) -Obtain agreed upon Hazard (GMRS) to proceed with the SPRA (NRC) -Complete Seismic Risk Assessment (PG&E) 61}}