ML19325D673

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Attachment 2 - Callaway Energy Center Seismic Probabilistic Risk Assessment in Response to 50.54(F) Letter with Regard to NTTF 2.1 Seismic - Supplemental Information
ML19325D673
Person / Time
Site: Callaway Ameren icon.png
Issue date: 11/21/2019
From:
Ameren Missouri, Union Electric Co
To:
Office of Nuclear Reactor Regulation
Shared Package
ML19325D662 List:
References
ULNRC-06551
Download: ML19325D673 (25)


Text

Attachment 2 to ULNRC-0655 1 Page 1 of 25 Callaway Energy Center Seismic Probabilistic Risk Assessment in Response to 50.54(F) Letter with Regard to NTTF 2.1 Seismic Supplemental Information Page 1 of 25 to ULNRC-0655 1 Page 2 of 25 Table of Contents 1 .0 Introduction 3

2.0 Model Refinements 3

2.1 Update to Seismic PRA Relay Database 3

2.2 Updated Component Mapping for Fragility Group SF-SBO12X 3

2.3 Update ofMutually Exclusive Logic 3

2.4 Updated Component Mapping for Fragility Group RelayO.l 8DG 4

2.5 Update of Operator Action OP-XHE-FO-TDPMNL 4

2.6 Fragility Parameter Updates 15 3.0 Model Sensitivities 16 3.1 fragility Groups Sf-AB-SURROG and SF-AXB-MV Sub-Grouping 16 4.0 Updated Model Results 23 Page 2 of 25 to ULNRC-0655 1 Page 3 of 25 1.0 Introduction The purpose of this document is to provide supplemental information to the Callaway Energy Center S-PRA 2.1 Submittal. Following Fact and Observation (F&O) closure for the S-PRA model, model refinements and sensitivities have been performed to refine the CEC S-PRA model, and improve risk metric results based on the insights. The following subsections provide: (1) a description of the changes to the model which was documented and submitted as part of the 2.1 Submittal and the updated risk-metric results, (2) a description ofthe sensitivities performed on the S-PRA model to identify areas of future refinement and potential improvements to risk-metric results, and (3) the top model contributors after performing the changes as described in (1) and as assessed in (2).

2.0 Model Refinements Following the CEC F&O Closure the following model changes have been made:

1 Incorporated an updated version ofthe Seismic PRA Relay Database (Revision 3).

2. Updated component mapping of fragility group SF-SB1O2X based upon plant-specific insights.

3 . Updated mutually exclusive logic for relay groups

4. Updated component mapping for fragility group Relay_O. 1 8DG base upon plant-specific insights.
5. Incorporated updated timing input for operator action to manually operator the turbine-driven pump (OP-XHE-FO-TDPMNL). Performed detailed seismic HRA for bin $H2.
6. Incorporated fragility parameter updates for fragility groups SF-EEGO1X (CCW HXs), SF-IE-S3 (VSLOCA), Sf-RLOXX (Main Control Panels RLO 1 RLOO6 and RLO 1 3 RL026),

SF-ABTNX (N2 Tanks TKAO2 TKAO5), and SF-XPBO5 (AEPS Transformer).

2.1 Update to Seismic PRA Relay Database Following the F&O Closure, a cutset review meeting was held to identify potential areas of refinement for the S-PRA model. Based on this review, Callaway reached out to a supporting vendor to determine if any conservative component mapping was being applied for various fragility groups. Based on this review, it was determined that an older revision of the S-PRA relay database (Revision 2) was still being credited in the S-PRA model. Revision 3 of the S PRA relay database incorporates refinements to various relay mapping.

2.2 Updated Component Mapping for Fragility Group SF-$BO12X Based on review of the S-PRA model it was determined that fragility group SF-SB1O2X was mapped to failing reactor trip, but loss of the cabinet is expected to cause a reactor trip. The cabinet failure is therefore screened from failing the reactor trip function. Removal of this mapping removes fragility group SF-SB1O2X from the model.

2.3 Update of Mutually Exclusive Logic Following the model update to reflect the latest 5-PRA relay database, mutually exclusive logic was reviewed to ensure that all fragility groups were appropriately populating through the model, and were not being excluded based on mutually exclusive logic. Four (4) fragility groups were determined to be impacted by the mutually exclusive logic:

Page 3 of 25 to ULNRC-0655 1 Page 4 of 25

. Fragility group Relay_O.72 This relay group fails basic events BB-M OV-OO-V8000A and BB-MOV-CC-V8000A which are identified as mutually exclus ive events in the internal events model.

. Fragility group Relay_O.81 This relay group fails basic events BB-M OV-OO-V8000B and BB-MOV-CC-V8000B which are identified as mutually exclus ive events in the internal events model.

. fragility group SF-BBRSV This fragility group fails multiple basic events which impact multiple identified mutually exclusive combinations in the interna l events model:

0 BB-PRV-CC-V455A and BB-MOV-OC-V455A 0 BB-PRV-CC-V456A and BB-PRV-OC-V456A 0 BB-MOV-OO-V8000B and BB-MOV-CC-V8000B 0 BB-MOV-OO-V8000A and BB-MOV-CC-V8000A

. Fragility group SF-FR-HEAF-A27 This fragility group fails basic events SA-SIS-TM TRAINA and SA-SIS-TM-TRATNB which are identified as mutually exclus ive events in the internal events model.

To correct the issues with the mutually exclusive logic, logic was added to ensure that mutually exclusive combinations can only propagated as mutually exclusive in the internal events model.

2.4 Updated Component Mapping for Fragility Group Relay_O.18DG Based on insights from review of the components mapped to fragilit y group Relay_O.1 8DG, it was detennined that Relay_O.l 8DG was incorrectly failing NBO1 1 1 and NBO21 1. When the operators go to reset the relay and start the EDGs, they ensure that the EDG output breakers are open or open them manually. Ifthe EDGs fail to start, the act of resettin g the relays now allows AEPS to be loaded on the bus. Based on this justification, the component mapping between fragility group RelayO. 1 8DG and NBO1 1 1 and NBO21 1 were remov ed.

2.5 Update of Operator Action OP-XHE-FO-TDPMNL Timing updates were provided for operator action to manually operato r the turbine-driven pump.

The timing updates and updated HRA analysis for OP-XHE-FO-TDPM NL were put through the EPRI HRA screening criteria. Detailed HRA was performed to refine bin 2 (SH2). Based on the extended Tdelay of 7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br />, the SF12 detailed analysis was determined to be applicable to bin 3

($H3). The resultant HFE updates were determined from this process.

lIFE jIi:

Specific Action REP Description OP-XHE-FO- 1 SH1-OP-XHE-FO- 8.0211-03 FAILURE TO OPERATE TDPMM. TDPMNL TDAFP lAW EC SUPPL.

GLINE, ATTACH. R (SEISMIC)

OP-XHE-FO- 2 SH2-OP-XHE-FO- 1.25E-02 FAILURE TO OPERATE TDPMNL TDPMNL TDAFP JAW EC SUPPL.

GLINE, ATTACH. R (SEISMIC)

OP-XHE-fO- 3 5H3-OP-XHE-FO- 1.25E-02 FAILURE TO OPERATE TDPMNL TDPMNL TDAFP lAW EC SUPPL.

GLINE, ATTACH. R (SEISMIC)

OP-XHE-FO- 4 SH4-OP-XHE-FO- 1.OOE+OO FAILURE TO OPERATE TDPMNL TDPMNL TDAFP lAW EC SUPPL.

GLLNE, ATTACH. R (SEISMIC)

Page 4 of 25 to ULNRC-0655 1 Page 5 of 25 SH2-OP-XffE-fO-TDPMNL, FAILURE TO OPERATE TDAFP IA WECSUPPL GLINE, ATTACH.

R (SEISMIC)

Plant Data File File Size file Date Record Date OP-XHE-FO-TDPMNLhra 1 175552 6:6/2019 6/6/2019 Name Date Analyst Rachel Christian, Westinghouse 6/6/2019 6/6/2019 HEP Summary I I I Pt P2 PCO Pc TnttI IWP Method CBDTM HCRJORE Maximum THERP HEP 3.02E-03 0.OOE+00 3.02E-03 9.SOE-03

-1 -

I.25E-02 Distribution Tvne Beta I Variance I .4lE-04 R:Aw I fV PkL icrnifltnt NA Action is being performed to mitigate a seismic-induced initiating event 1 Initial Conditions: Steady state fufl power operation.

2. Initiating Event:

Complete loss ofboth AC and DC power

3. Accident Sequence (Preceding functional failures and Successes):

Reactortrip successful S3O AC and DC failure

4. Preceding Operator Errors and Successes:

None Nothing is available due to complete loss ofAC and DC Operators alert emergency response center about condition.

5. Success Criteria:

R.3 CLOSE AFP Turb Mech Trip/Throt Hv Using The Manual Handwheel:

R4. CHECK At Least One OfThe Following OPEN -

ABHV0005, TDAFP Strn Sply from MS Loop 2 RI Slowly Crack OPEN, AlP Turb Mech Trip/Throt Hv, To Start Spinning AFW Pump Turbine:

R7. Slowly RAISE TDAFP To 3850 RPM R8. STABILIZE TDAFP Speed AT 3850 RPM R9. CHECK Auxiliary Feedwater Flowmte Indication -

AVAILABLE It is not available since there is a complete loss ofboth AC and DC power R9 RNO INSTALL Local Flowrate Monitoring using Attachment UU, Local Monitoring Auxiliary feedwater Flow Rates

6. Consequence ofFailure: SG dryout

. Procedures -

Cognitive Procedure IC SUPP GUIDE (EMERGENCY COORDINATOR SUPPLEMENTAL GUIDELINE)

Revision:21 Cognitive Step Number 6 Cognitive Instruction Step 6 RNO Page 5 of 25 to ULNRC-0655 1 Page 6 of 25 Attachment R, Starting TDAFP On Loss ofAC and DC Power Execution Procedure Execution: Not Selected Execution Instruction Job Performance Measure JPM: Not Selected Notes Seismic: The same procedures are used to mitigate initiati ng events, regardless of whether they occur as an interna seismically induced. Note that additional workload and distrac l event or are tions posed by the earthquake, for example damage assessm walkdowns, are addressed in the Cognitive Unrecovered ent assessment ofpcb failure of Attention due to worklo ad.

Trainini Classroom Training Simulator Training

. 0.5 per year jO.5 per year Crew Member Included Total Av&ible Required for Execution Shift Manager Notes No 1 Shift Supervisor 0 No STA 0 No 0 Reactoqperators Yes 2 1 Plantoperators Yes 2 2 Mechanics Yes 2 2 Electricians Yes 2 2 tC Technicians Yes 2 0 Health Physics Technicians Yes 2 0 Chernistiy Technicians Yes 0

Notes Manpower required is equivalent whether the action is implemented in response to an internal initiating event or induced event. Note that manpower needed for additional a seismically-workload and distractions posed by the earthquake, for examp assessment walkdowns, are addressed in the Cognitive Unreco le damage vered assessment.

Analyst Notes SPRA Detailed HRA A.4.

The TDAFP is running and is not stopped due to loss of DC power.

The TDAFP has been supplying the SG for 8 to 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> after the reactor trip and loss ofall AC power.

The heat load on the SG is considerably less than at reactor trip. The use of 50 minutes stated in the Supplementar reactor trip is considered to be extremely conservative for y Guide within this HFE.

It is assumed that the operator wilt be aware of the depleti on of the batteries at least an hour before it happens. Theref assumed the batteries deplete in 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> and the operato will ore it is rs take action to prepare for this at least an hour before it happens.

Onerator Interview Insiehts This guideline is entered based on directions from the Emerg ency Coordinator.

Location of equipment required is clearly marked in the TSC.

Step 6 provides several options of restoring injection. The PRA assumption is that the operators will choose to align the In addition to completing attachment R the operators will TDAFW.

also need to obtain SO level indication following attachm there is a complete loss ofboth AC and DC. ent U since The Control Room Staff would more likely stay in ECA-0

.0 (parent procedure) The Control Room Staff would more reset the TDAFP in parallel and implement loss of DC power likely try to The Control Room Staff would more likely start the Non-S Feed Pump. The foldout Page for ECA-0.0 directs operato afety Aux rs to use Attachment A, ALTERNATE LOW PRESSURE FEEDWATER and use FSGs.

Equipment used is clearly marked and locations provid ed. (top drawer of TSC Cabinet). Easy to find and use.

department has conducted training on this several times Operations Training No insights specific to seismic. This action has not been reviewed by an operator for seismic considerations.

Page 6 of 25 to ULNRC-0655 1 Page 7 of 25 Timing Analysis Tsw HOW Tdefay Tcog Texe THorn OU1it ama State I I - I -

1-0 L?S T --

$Hours 7 Hours Minutes TCEC 37.5 Minutes Time available for cognition and recovery 22.5 Minutes Time available for recovery 22.5 Minutes SPAR-H Available time (cognitive) 22.5 Minutes SPAR-H Available time (execution) ratio 1.60 Minutes EPRI Minimum level of dependence for recovery -

MD Notes Tsw= 8hoursforbatterydepletion Tdelay = 7 hours8.101852e-5 days <br />0.00194 hours <br />1.157407e-5 weeks <br />2.6635e-6 months <br /> before the operators start to take action to compensate for the battery depletion. Seismic approach to increase Tdelay by 2 minutes account for additional distractions and confusion following the earthquake is not directly applicable for this action based on long Tdelay.

Tcog = 0 hours0 days <br />0 hours <br />0 weeks <br />0 months <br /> due to the long time before the battery depletion. The operators will be aware that the batteries are depleting and will not need any other indications. Seismic approach to increase Tcog by 25% to account for additional distractions and confusion following the earthquake is not directly applicable for this action based on long Tdelay. Note also that adjustment of Cognitive Unrecovered pcb further degrades the action reliability due to additional distractions and workload.

Texe 30 minutes to perform all ofthe local actions + 7.5 minutes for seismic (25% increase to account for additional distractions

..! confusionfollowing the earthquake)

Cocnitive Analysis Pc Failure Mechanism Branch HEP Pca: Availability of Information a O.OOE+OO Pcb: Failure ofAftention h O.OOE+OO Pcc: Misread/miscommunicate data a O.OOE+OO Pcd: Information misleading a O.OOE+OO

?ce: Skip a step in procedure g 6.OOE-03 Pcf: Misinterpret Instructions a O.OOE+OO Peg: Misinterpret decisionlogic 1 O.OOE+OO Pch: Deliberate vIolation a O.OOE+OO Initial Pc(without recovery credited) 6.OOE-03 Notes Accessibility dunnga seismic event should be confirmed via an operator pathway walkdown.

Page 7 of 25 to ULNRC-0655 1 Page 8 of 25 Pea: Availability of information Notes/Assumptions: Assumed that there is reasoizabte anatog ue instrumentation alternative to the alarm in the event ofsptir atui,ns due to relay chattei ious lntei,zat events response applicable to S-PRA.

md. Avail in CR CR Ind Accurate WarnIAtt in Proc. Training on End. Value

-EE:- . .

No (g) I e+OOO Page 8 of 25 to ULNRC-0655 1 Page 9 of 25 Pcb: Failure of Attention Notes/Assztmptions: Workload is set to highfor at! actions occurring prior to the damage assessment walkdowns (assumed to be eight hoursfollowing the earthquake).

Assunied that there is reasonable analogue instritineutation atternative to the alarm in the event ofspurIous alarms dtte to relay chatter.

Alt other responses based on Internal Events.

Low vs. Hi Workload Check vs. Monitor Front vs. Back PaneI Alarmedvs.tkt Value Front Low Front Check r==

I_____

U (h) 0 Oe+000 (I) O.Oe+000 E___ _1-_----____- O)TSe-004 High ____

r::zz:::z tic) I .5e-002 Monitor (m)iSe.002 8ack[___

Page9of25 to ULNRC-0655 1 Page 10 of25 Pcc: MisreadJmiscoinmunicate data Notes/Assumptions: The CEC seismic NRA ttsed the yes branch for formal Cornmttnicatiol1sfor SH2 where mitigation using conventionalprocethtres andprotocol is expected.

Internal events response applicable to 5-PRA.

Easy md. EatoLoce Good Goodad Indictor FormaIComrnunicon Yes J Vatue (a) 0 Oe+000 (b) 3 Oe-003 Yes aU (c) f Oe-003 (U) 4Oe-003 Yes Good (e) 3Oe-003 Not easy I 1*

Yes (0 6.Oe-003 I Bad () 4.Oe-003 (h) 7.Oe-003 fçJfgnationcis1eadin NotesAssutnptions: Internal events iesponse assumed to be applicable to S-PRA.

Alt Cues asStated Yes f Yes secinciraininJnerairrainino

} Value (a) 0 Oe+000 jNo 0) 3Oe-003 I Yes No (c) I .Oe-002 Yes fP1U (U) I Oe-OO1 I...

(e) I .Oe+000 Page 10 of 25 to ULNRC-0655 1 Page 11 of25 iccSkip a step in procedure NotesMssttrnptions: The CEC S-PRA seismic HRA selects multiple for alt seismic HFEs.

Willie the FOPs wotild be given priority.

some additionalpiocedure implementation is anticipatedfottowing an earthqttokefor example the seismic response procedure.

At! other responses based on Internal Events.

Obvious vs. Hidden Single vs. Multiple GraphicaIy Distinct Placekeeping Aith Vatue Yes Yes I.. (a) 99e-004 SinIe (b) 33e-003 No (C) 3.Oe-003 Obvious L. (U) I Oe-002 Ye fe) 2 Oe-003 Mutipte (0 43e-003 Hidden No

z. Cc;) 6 Oe-003 (h) I ,3e-002 (I) I ,Oe-OO1 Pcf: Misinterpret Instructions NotesAssumptions: Internet events response applicable to 5-PRA.

Standard or Ambpiotis Wording RequiredInformaton Training on Step Value Yes Standard t) U Oe+000 Yes jNO I i_ (b) 3Oe-003 fc) 3Oe-002 Yes Cd) 3Oe-003 AmbIguous fe) 3.Oe-002 1 No (1) 6.Oe-003 (9) 6.Oe-002 Page 11 of25 to ULNRC-0655 1 Page 12 of 25 Pcg: Misinterpret decision 1gjc Notes/Assumptions: Internal events response applicable to SPRA NOT Statement AtIDorOR j

BOTH AND 8 OR Practiced Value Scenariol g2; Y

- fg) I ,Oe-002

._F *

(k) O,Oe+000 S  : (1) 0 Oe+000 Pch: Deliberate violation Notes Assumptions: Internal events response applicable to 5-PRA.

etieflnAdequacy ot Reasonaie Consec!iesxe d PollcyofVerbW Value Yes CL

() 0 Oe+000 (c)1Oe+000 Page 12 of 25 to ULNRC-0655 1 Page 13 of25 I__

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- -- --- - -- -- - 2 Q I Pca n/a 1.OOE+OO 0.0 Pcb n!a I.OOE+00 0.0 Pcc n1a I.OOE+00 0.0 Pcd n/a 1.OOE+00 0.0 Pce 6OOE-03 X HD 5.03E-01 3.02E-03 Pcf n/a 1.OOE+00 0.0 n/a JOOF+00 0.0 Pch n/a I .OOE+00 0.0 Final Pc (with recovery credited) 3.02E-03 Notes Additional distractions created by response to the earthquake (for example the damage assessment walkdowns) would limit time and resources available for these cognitive recoveries. Self-review DF increased to High.

Sigma Table Plant Typ LB__ Sigma BWR CP1 04 0.7 1 CP2 0.2 058 0.96 CP3 0.59 0.75 0.91 PWR CPI 0.26 0.88 CP2 0.07 0.38 0.69 CP3 0.77 Sigma: 5.70E-O1 HEP: O.OOE+O0 Notes/AsmJti9ns.

Execution Prfnrmne hinino Intnr

-.--,:-.---..---..j Lighting Emergency Heat/Humidity Normal Radiation Non Radiation Area Atmosphere Normal Special Requirements Tools Required Soecial Reauirements Tools Adenuate Special Requirements Tools Available Complexity of Response Execution Simple Equipment Accessibility (Cognitive) Main Control Room Accessible Enuinment Accessibility tExecution T-lAf-Accessible Stress jh Plant Response As Expected: Yes Workload: High Performance Shaping Factors: Negative Notes Post-earthquake workload and stress expected to be high. performance shaping factors expected to be negative.

Page 13 of 25 to ULNRC-0655 1 Page 14 of 25 Execution Unrecovered rt;cedure Comment Step No. Instruction/ THERP EfforType Stress factor Override Comment Table Item HE?

Attachment R Check at least EOM 20-7 1 1 .3E-3 Step4 one of the following open: EOC 20-13 2 High 3.80E-03 A3HV0005 or A3HV0006 Location: AFW pump room Total S epEP 2.55E-02 Stabilize EOM 20-7 Attachment R TDARP to EOC 1 I.3E-3 J High Step8 2850RPM 3 1 1 30E 03 Location:

I Total Step HE? 130E-02 Install local EOM 20-7 1 t.3E-3 flowrate monitoring using Attachment U, Attachment R local

- levels.

Location:

Total Step HE? 2.55E-02 Locally operate valves Attachment R as directed by EOM 20-7 1 1 .3E-3 High Step 10 RNO the control roomITSC.

Location:

Total Step HE? 6.50E-03 Execution Recovered Critical Step Recovery Action HE? (Cdt) HE? (Rec) Dep. Cond. HE? Total for Step No. $tepNo.

Attachment R tRee)

Check at least 2.55E-02 Step4 one of the 3.78E-03 following open:

ABHV0005 or ABHV0006 Attachment R Locally operate 6.50E-03 MD l48E-O I Step 10 RNO valves as directed by the control rooinIfSC.

Attacluzient R Stabilize TDARP I 30E-02 Step S to2850 RPM 1 .93E-03 Attachment R Locally operate 6.50E-03 MD l.48E-Ql Step 10 RNO valves as directed by the control rooiulTSC.

Attachment R Install local 2.55E-02 Step 9 RNO flowrate 3.78E-03 monitoring using Attachment U, local monitoring steam generator wide range levels.

Attachment R Locally operate 6.50E-03 MD 1 .48E-Ol Step 10 RNO valves as directed by the control room/TSC.

Total Unrecovered: 6.40E-02

Total Recovered: 9.50E-03 Page 14 of 25

Attachment 2 to ULNRC-0655 1 Page 15 of25 2.6 Fragility Parameter Updates The following parameters for the specified fragility groups have been updated. Note the previous value used in the F&O Closure reviewed SPRA model are also shown.

Fragility PGA_min p p p PGA_med Failure (HCPLF) Mode F&O Sf-EEGO1X 0.25 040 0.24 0.32 0.63 Anchorage Closure Model Updated SF-EEGO1X 0.45 0.40 0.24 0.32 1.14 Anchorage Parameters Fragility PGA_miu PC Pr Pu PGA_med Failure tHCPLF) Mode F&O Sf-IE-S3 0.2 0.32 0.24 0.4 0.51 Bending Closure Model Updated Sf-IE-S3 0.87 0.45 0.24 0.38 2.48 Bending Parameters Fragility PGA_min PC Pr Pu PGA_med Failure (IICPLF) Mode F&O SF-RLOXX 0.22 0.40 0.24 0.32 0.63 Anchorage Closure Model Updated SF-RLOXX 0.31 0.45 0.24 0.38 0.88 Anchorage Parameters fragility PGA_min PC Pr Pu PGA_med Failure (HCPLF) Mode F&O Sf-ABTNX 0.25 045 0.24 0.38 0.56 Anchorage Closure Model Updated SF-ABTNX 1.63 0.35 0.24 0.26 3.71 Anchorage Parameters Fragility PGA_min p r u PGAjned failure (HCPLF) Mode F&O Sf-XPBO5 0.47 0.40 0.24 0.32 1.19 Anchorage Closure Model Updated SF-XPBO5 0.37 0.35 0.24 0.26 0.83 Anchorage Parameters Page 15 of25 to ULNRC-0655 1 Page 16 of25 3.0 Model Sensitivities Following the f&O Closure, the following sensitivities have been performed to identify potential areas of model refinement:

1 . Fragility Groups SF-AB-SURROG and SF-AXB-MV sub-grouping.

3.1 Fragility Groups SF-AB-SURROG and SF-AXB-MV Sub-Grouping The full correlation assumption has the possibility to introduce conservatisms for seismic failures of SSCs which are represented by large surrogate fragility groups that are likely not correlated since the SSCs are located on different elevations. There are two surrogate fragility groups for components the in Auxiliary Building; one group (SF-AB-SURROG) is assigned to all SC-I check valves in the Auxiliary Building and the other (SF-AXB-MV) is assigned to all SC-I MOVs in the Auxiliary Building.

These fragility groups SF-AB-SURROG and SF-AXB-MV were identified for a dedicated sensitivity to understand which components in these large fragility groups are risk significant and to determine if any additional refinement of these groups or specific components in these groups could be performed.

Since the components in both of these fragility groups span multiple elevations of the Auxiliary Building, this sensitivity separated components into sub-groups based on the major elevations ofthe Auxiliary Building (i.e., 1974, 2000, 2026, and 2047). The following table documents the fragility sub-groups by elevation and the associated components. Note that the original fragility parameters calculated for the surrogate groups were applied across all associated sub-groups.

Fragility Group Component MappedBE SF-AB-$URROG-l 974 ALV0003 AL-CKV-CC-ALVOO3 SF-AB-SURROG-1974 BG848 I A BG-CKV-CC-848 1A Sf-AB-SURROG-1974 BG848 lB BG-CKV-CC-848 lB Sf-AB-SURROG- 1974 BG8497 BG-CKV-CC-$497 SF-AB-SURROG- 1974 BG8546A BG-CKV-CC-V8546A SF-AB-SURROG-1974 BG8546A BG-CKV-OO-V8546A SF-AB-SURROG-1974 BG8546B BG-CKV-CC-V8546B SF-AB-SURROG-1974 BG8546B BG-CKV-OO-V8546B Sf-AB-SURROG- 1 974 BGV0589 BG-CKV-CC-V589 Sf-AB-SURROG-1974 BGVO59O BG-CKV-CC-V590 SF-AB-SURROG- I 974 BGVO59 1 BG-CKV-CC-V59 1 Sf-AB-SURROG- I 974 BGVO59 1 BG-CKV-OO-V59 1 Sf-AB-SURROG-1974 BGVO6O5 BG-CKV-CC-V605 Sf-AB-SURROG-1974 BGVO6O6 BG-CKV-CC-V606 Sf-AB-SURROG-1974 BGV0645 BG-CKV-CC-V645 SF-AB-SURROG-1974 EJ8958A EJ-CKV-CC-V8958A SF-AB-SURROG-1974 EJ8958B EJ-CKV-CC-V8958B SF-AB-SURROG-1974 EJ8969B EJ-CKV-CC-V8969B SF-AB-SURROG-1974 EM8922A EM-CKV-CC-V8922A SF-AB-SURROG-l 974 EM8922A EM-CKV-IL-V8922A SF-AB-SURROG-l 974 EM8922A EM-CKV-OO-V8922A SF-AB-SURROG-l 974 EM8922B EM-CKV-CC-V8922B SF-AB-SURROG-1974 EM8922B EM-CKV-IL-V8922B SF-AB-SURROG-1974 EM8922B EM-CKV-OO-V8922B Page 16 of 25 to ULNRC-0655 1 Page 17 of25 Fragility Group Component MappedBE SF-AB-SURROG-1974 EM8926A EM-CKV-CC-V8926A Sf-AB-SURROG-1974 EM8926A EM-CKV-OO-V8926A SF-AB-SURROG-1974 EM8926B EM-CKV-CC-V8926B SF-AB-SURROG-1974 EM8926B EM-CKV-OO-V8926B SF-AB-SURROG-1 974 EMV0005 EM-CKV-CC-V005 SF-AB-SURROG-1974 EMV0007 EM-CKV-CC-V007 SF-AB-SURROG-2000 AEVO 124 AE-CKV-CC-AEV 124 SF-AB-SURROG-2000 kEV0125 AE-CKV-CC-AEVI25 Sf4d3-SURROG-2000 AEVO 126 AE-CKV-CC-AEV1 26 Sf-AB-SURROG-2000 AEVO 127 AE-CKV-CC-AEV 127 Sf-AB-SURROG-2000 ALFVOO3O AL-ARC-CC-ALFV3O SF-AB-SURROG-2000 ALFVOO42 AL-ARC-CC-ALFY42 SF-AB-SURROG-2000 ALV000 1 AL-CKV-CC-ALVOO 1 SF-AB-SURROG-2000 ALV0002 AL-CKV-CC-ALVOO2 Sf-AB-SURROG-2000 ALV0006 AL-CKV-CC-ALVOO6 SF-AB-SURROG-2000 ALV0009 AL-CKV-CC-ALVOO9 SF-AB-SURROG-2000 ALVOO 12 AL-CKV-CC-ALVO 12 Sf-AB-SURROG-2000 ALVOO 1 5 AL-CKV-CC-ALVO 1 S SF-AB-SURROG-2000 ALVOO33 AL-CKV-CC-ALV033 SF-AB-SURROG-2000 ALVOO36 AL-CKV-CC-ALVO36 Sf-AB-SURROG-2000 ALVOO45 AL-CKV-CC-ALVO45 Sf-AB-SURROG-2000 ALVOO48 AL-CKV-CC-ALVO48 SF-AB-SURROG-2000 ALVOO53 AL-CKV-CC-ALVO53 Sf-AB-SURROG-2000 ALVOO54 AL-CKV-CC-ALVO54 Sf-AB-SURROG-2000 ALVOO57 AL-CKV-CC-ALVO57 SF-AB-SURROG-2000 ALVOO62 AL-CKV-CC-ALVO62 Sf-AB-SURROG-2000 ALVOO67 AL-CKV-CC-ALVO67 Sf-AB-SURROG-2000 ALVOO72 AL-CKV-CC-ALVO72 Sf-AB-SURROG-2000 ALVO 14$ AL-CKV-CC-ALV148 SF-AB-SURROG-2000 ALVO 149 AL-CKV-CC-ALV149 SF-AB-SURROG-2000 ALVO1 50 AL-CKV-CC-ALV1 50 SF-AB-SURROG-2000 ALVO15 1 AL-CKV-CC-ALV1 1 SF-AB-SURROG-2000 ALVOI52 AL-CKV-CC-ALV152 Sf-AB-SURROG-2000 ALVO I 53 AL-CKV-CC-ALV1 53 Sf-AB-SURROG-2000 ALVO 1 54 AL-CKV-CC-ALV154 Sf-AB-SURROG-2000 ALVO1 55 AL-CKV-CC-ALV1 55 Sf-AB-SURROG-2000 BG8440 BG-CKV-OO-V8440 SF-AB-SURROG-2000 EJ8730A EJ-CKV-CC-V8730A Sf-AB-SURROG-2000 EJ8730B EJ-CKV-CC-V8730B Sf-AB-SURROG-2000 EJ8969A EJ-CKV-CC-V8969A SF-AB-SURROG-2026 EGV0003 EGCKV-CC-V003 Sf-AB-SURROG-2026 EGV0003 EG-CKV-OO-V003 SF-AB-SURROG-2026 EGV0007 EG-CKV-CC-V007 Page 17 of 25 to ULNRC-0655 1 Page 18 of25 Fragifity Group Component MappedEE Sf-AB-SURROG-2026 EGV0007 EG-CKV-OO-V007 SF-AB-SURROG-2026 EGVOO 12 EG-CKV-CC-VO 12 SF-AB-SURROG-2026 EGVOO 12 EG-CKV-OO-VO 12 Sf-AB-SURROG-2026 EGVOO 1 6 EG-CKV-CC-VO 16 SF-AB-SURROG-2026 EGVOO 1 6 EG-CKV-OO-VO 16 Sf-AB-SURROG-2026 EGVOO36 EG-CKV-CC-V036 SF-AB-SURROG-2026 EGVOO61 EG-CKV-CC-V06 1 SF-AB-SURROG-2026 EGVO 130 EG-CKV-CC-V 130 SF-AB-SURROG-2026 EGVO 1 3 1 EG-CKV-CC-V1 31 SF-AB-SURROG-2026 FCV0001 fC-CKV-CC-fCVOO 1 SF-AB-SURROG-2026 FCV0002 fC-CKV-CC-FCVOO2 SF-AB-SURROG-2026 fCV0024 fC-CKV-CC-FCVO24 SF-AB-SURROG-2026 FCVOO25 FC-CKV-CC-fCV025 SF-AB-SURROG-2047 ABV0345 AB-CKV-CC-PRV1IA SF-AB-SURROG-2047 ABV0346 AB-CKV-CC-PRVIN2 SF-AB-SURROG-2047 ABV0347 AB-CKV-CC-PRV2IA SF-AB-SURROG-2047 ABV0348 ABCKV-CC-PRV2N2 SF-AB-$URROG-2047 ABV0349 AB-CKV-CC-PRV3IA SF-AB-SURROG-2047 ABVO35O AB-CKV-CC-PRV3N2 SF-AB-SURROG-2047 ABVO35 1 AB-CKV-CC-PRV4IA Sf-AB-SURROG-2047 ABV0352 AB-CKV-CC-PRV4N2 Sf-AXB-MV-1974 ALHVOO3O AL-MOV-CC-ALHV3O Sf-AXB-MV-1 974 ALHVOO3 1 AL-MOV-CC-ALHV3 I Sf-AXB-MV-1974 ALHVOO32 AL-MOV-CC-ALHV32 Sf-AXB-MV-1974 ALHVOO33 AL-MOV-CC-ALHV33 SF-AXB-MV-1974 ALHVOO34 AL-MOV-OC-ALHV34 SF-AXB-MV- 1974 ALHVOO35 AL-MOV-OC-ALHV35 SF-AXB-MV-1 974 ALHVOO36 AL-MOV-OC-ALHV36 Sf-AXB-MV-I 974 BGFCVO12 1 BG-AOV-OC-FCV12 I SF-AXB-MV- 1 974 BGFCVO 124 BG-AOV-OC-FCV 124 SF-AXB-MV-1974 BGHV8 1 10 BG-MOV-OO-HV8 110 Sf-AXB-MV-1974 BGHV8 1 1 1 BG-MOV-OO-HV8 111 Sf-AXB-MV-1974 BGHV8357A BG-MOV-CC-8357A Sf-AXB-MV-1974 BGHV8357B BG-MOV-CC-8357B SF-AXB-MV-1 974 BNHV8806A BN-MOV-OO-V8806A SF-AXB-MV- 1 974 BNHV88O6B BN-MOV-OO-V8806B SF-AXB-MV-1974 BNHV88 12A BN-MOV-OO-V88 12A Sf-AXB-MV-1974 BMIV88 12B BN-MOV-OO-V8$ 1 2B SF-AXB-MV-1974 BN}1V88 1 3 BN-LSW-OO-88 13 SF-AXB-MV-1974 BN}1V88 13 BN-LSW-OO-88 131 SF-AXB-MV-1974 BNNV88 13 BN-LSW-OO-HV88 13 Sf-AXB-MV-1 974 BNHV88 13 BN-MOV-OO-HV88 13

$F-AXB--MV-1974 BNLCVO1 12D BN-MOV-CC-V1 12D Page 18 of25 to ULNRC-0655 1 Page 19 of25 Fragility Group Component MappedBE Sf-AXB-MV-1974 BNLCVO1 12D BN-MOV-OO-V1 12D SF-AXB-MV- I 974 BNLCVO 1 12E BN-MOV-CC-V1 12E Sf-AXB-MV-1974 BNLCVO1 12E BN-MOV-OO-V1 12E SF-AXB-MV- 1974 EJFCVO6 10 EJMOV-OC-fCV61O SF-AXB-MV-1974 EJFCVO61 1 EJ-MOV-OC-FCV61 1 SF-AXB-MV- 1974 EJHV88O4B EJ-MOV-CC-V8804B SF-AXB-MV- 1 974 EJHV88 1 1A EJ-MOV-CC-V88 1 1A Sf-AXB-MV-1974 EJHV881 lB EJ-MOV-CC-V8$ I lB SF-AXB-MV- 1974 EMHV88O3A EM-MOV-CC-V8$03A Sf-AXB-MV- 1974 EMHV88O3A EM-MOV-PG-V8803A SF-AXB-MV- 1974 EMHV88O3B EM-MOV-CC-V8803B SF-AXB-MV- 1974 EMHV88O3B EM-MOV-PG-V8803B SF-AXB-MV-1 974 EMHV88O7A EM-MOV-CC-V8807A SF-AXB-MV- 1 974 EMHV88O7B EM-MOV-CC-V8807B SF-AXB-MV- 1974 EMHV88 14A EM-LSW-OO-V88 14A Sf-AXB-MV-1974 EMHV88 14A EM-MOV-OO-V88 14A SF-AXB-MV-1974 EMHV88I4B EM-LSW-OO-V88 14B SF-AXB-MV- 1 974 EMHV$8 14B EM-MOV-OO-V88 14B SF-AXB-MV-1 974 EMVOO4 1 EM-XVM-PG-V04 1 SF-AXB-MV- 1974 EMVOO42 EM-XVM-PG-V042 Sf-AXB-MV-1974 EMV0244 EM-XVM-PG-V244 Sf-AXB-MV-1974 EMV0245 EM-XVM-PG-V245 Sf-AXB-MV-2000 ALHV0005 AL-MOV-OC-ALHVO5 Sf-AXB-MV-2000 ALHV0006 AL-AOV-OC-ALHVO6 Sf-AXB-MV-2000 ALHV0007 AL-MOV-OC-ALHVO7 Sf-AXB-MV-2000 ALHV000$ AL-AOV-OC-ALHVO8 Sf-AXB-MV-2000 ALHV0009 AL-MOV-OC-ALHVO9 SF-AXB-MV-2000 ALHVOO 10 AL-AOV-OC-ALHV1O SF-AXB-MV-2000 ALIIVOO 1 1 AL-MOV-OC-ALHV1 1 SF-AXB-MV-2000 ALHVOO 12 AL-AOV-OC-ALHV12 Sf-AXB-MV-2000 BGHVS I 05 BG-MOV-OO-HV8 105 Sf-AXB-MV-2000 BGHV8 1 06 BG-MOV-OO-HV8 106 SF-AXB-MV-2000 BGLCVO1 12B BG-MOV-OO-1 12B SF-AXB-MV-2000 BGLCVOI 12C BG-MOV-OO-1 12C SF-AXB-MV-2000 EGHVO69A EG-AOV-OO-HV69A SF-AXB-MV-2000 EGHVO69B EG-AOV-OO-HV69B SF-AXB-MV-2000 EGHVO7OA EG-AOV-OO-HV7OA Sf-AXB-MV-2000 EGHVO7OB EG-AOV-OO-HV7OB SF-AXB-MV-2000 EJFCVO6 I 8 EJ-AOV-CO-FCV6 18 Sf-AXB-MV-2000 EJFCVO6 19 EJ-AOV-CO-FCV6 19 SF-AXB-MV-2000 EJHCVO6O6 EJ-AOV-OC-11CV606 Sf-AXB-MV-2000 EJHCVO6O7 EJ-AOV-OC-HCV6O7 SF-AXB-MV-2000 EJHV87 16A EJ-MOV-OC-V87 I 6A Page 19 of25

Attachment 2 to ULNRC-0655 1 Page 20 of 25 Fragility Group Component MappedBE Sf-AXB-MV-2000 EJHV87 1 6A EJ-MOV-OO-V871 CA SF-AXB-MV-2000 EJHV87 163 EJ-MOV-OC-V87 16B SF-AXB-MV-2000 EJ}{V87 1 6B EJ-MOV-OO-V87 16B Sf-AXB-MY-2000 EJNV88O4A EJ-MOV-CC-V8804A Sf-AXB-MV-2000 EJHV88O9A EJ-MOV-OC-V8809A SF-AXB-MV-2000 EfflV88O9B EJ-MOV-OC-V8809B Sf-AXB-MV-2000 EJHV884O EJ-MOV-FH-HV8840 SF-AXB-MV-2000 EJHV884O EJ-MOV-IR-HV8840 Sf-AXB-MV-2000 E1HV8840 EJMOV-SO-HV884O Sf-AXB-MV-2000 EMHV88O 1A EM-MOV-CC-V8$O 1A Sf-AXB-MV-2000 EMHV88O IA EM-MOV-PG-V8801A SF-AXB-MV-2000 EMHV88O lB EM-MOV-CC-V880 lB Sf-AXB-MV-2000 EMHV88O lB EM-MOV-PG-V8$O lB SF-AXB-MV-2000 EMHV88O2A EM-MOV-FH-8802A SF-AXB-MV-2000 EMHV88O2A EM-MOV-IR-8802A SF-AXB-MV-2000 EMHV88O2A EM-MOV-SO-8802A Sf-AXB-MV-2000 EMHV88O2B EM-MOV-F H-8802B SF-AXB-MV-2000 EMHV88O2B EM-MOV-IR-8802B SF-AXB-MV-2000 EMHV88O2B EM-MOV-SO-$802B SF-AXB-MV-2000 EMHV8835 EM-MOV-OC-HV8835 SF-AXB-MV-2026 EGHVOO 1 5 EG-MOV-CC-HV1 5 SF-AXB-MV-2026 EGHVOO 1 5 EG-MOV-OO-HV1 5 SF-AXB-MV-2026 EGHVOO 1 6 EG-MOV-CC-HV1 6 Sf-AXB-MV-2026 EGHVOO 16 EG-MOV-OO-HV16 SF-AXB-MV-2026 EGHVOO54 EG-MOV-CC-HV54 The fragility ranking tool was ran on both the CDF and LERF results ofthe sensitivity model were compared to the original model for reason . The results ableness and are shown in the tables below.

fragility sub-groups Sf-AXBMV-2000, $F-AX Note that the B-MV-1974, and SF-AB-SURROG-2000 as risk significant contributors; suggesting that are showing up the components in these elevation groups can for refinements to help gain additional seismi be targeted c margin. Note that a review of the quanti shows that with the addition ofthese sub-groups, fication results the S-PRA CDF and S-PRA LERF risk metric to increase. This is attributed to the additional results start number of cutsets being generated.

Page 20 of 25

Attachment 2 to ULNRC-0655 1 Page2l of25 Fragility Group Sub-Grouping Sensitivity CD!? Results Hazard HRA Earthquake Scenario ACUBE ACUBE ACUBE Bin Frequency Truncation CDF Range Cutsets CCDP COF

%GO1 O.lg to O2g 1 8.02E-04 1.OOE-1O 1000 929E05 7A5E-08 0.18%

%G02 0.2g to 0.3g 2 l.80E-04 5.OOE-09 1000 3.61E-03 6.50E-07 1.6%

%G03 0.3g to 0.4g 2 6.4$E-05 5.OOE-09 1 000 E-02 3.05E-06 7.3%

%G04 0.4g to 0.45g 2 1.67E-05 5.OOE-09 1000 2.OOE-0I 3.35E-06 8.0%

%G05 0.45g to0.5g 2 1.16E-05 1.OOE-08 1000 382E01 4.43E-06 10.6%

%G06 0.5gto0.55g 3 8.13E-06 5.OOE-08 1000 7.05E-01 5.73E-06 13.7%

%G07 0.55g to 0.6g 3 5.87E-06 2.OOE-07 1000 7.41E-01 4.35E-06 10.4%

%G08 0.6g to 0.7g 4 7,60E-06 5.OOE-07 1000 934E01 71OE-06 17.0%

%G09 0.7g to 0.8g 4 4.45E-06 5.OOE-07 1000 9.63E-01 4.28E-06 10.3%

%G10 > 0.8g 4 8.85E-06 2.OOE-06 1000 985E..0I 8.71E-06 20.9%

Total SCDF 4J7E-05 TotaISCDf (w/PAf) 3.75E-05 fragility Group Sub-Grouping Sensitivity LERF Results Scenario Hazard IERA Earthquake ACUBE ACUBE ACUBE  %

Truncation Bin Frequency Cutsets CLERP LERF LERF

%G01 0.lg to 0.2g 1 8.02E-04 l.OOE-l0 7100 8.OE-07 6.39E-10 0.02%

%G02 0.2g to 0.5g 2 2.73E-04 IOOE-09 7100 55E05 1.49E-08 0.40%

%G03 0.5g to O.6g 3 1.40E-05 1.OOE-09 7100 9.4E-03 1.31E-07 3.53%

%G04 0.6g to 0.8g 4 1.21 E-05 2.OOE-09 7100 3.5E-02 4.28E-07 I 1.50%

%G05 0.8g to lg 4 4.49E-06 5.OOE-09 7100 14E01 6.35E-07 17.06%

%G06 lgto 1.2g 4 1.89E-06 1.20E-08 7100 35E01 6.56E-07 17.63%

%G07 1.2g to 1.4g 4 1.0113-06 4.OOE-08 7100 6.OE-01 6.08E-07 16.33%

%G08 l.4g to 1.6g 4 5.68E-07 6.OOE-08 7100 74E01 4.22E-07 I 1.35%

%G09 1 .6g to 2g 5.29E-07 2.OOE-t)7 7 1 00 8.9E-0 1 4.70E-07 12.63%

%G10 2g 4 3.63E-07 2.OOE-07 7100 98E01 3.55E-07 9.55%

Total SLERF 3.72E-06 Total SLERF (WPAF) 3.35E-06 Page2l of25 to ULNRC-0655 1 Page 22 of 25 fraiitv Groun Sub-Grouning Sensitivity CDF Fragili ty Ranking Fragility Group . .

Description Percent SF-IE-T1 Reduction Seismic induced loss ofoffsite power 70.1%

SF-NN ox Seismic Induced Failure of 120 VAC Distribution Panels NNO1 NNO2, NNO3 and NNO4 Relay_0.18DG 4.3%

Relay Fragility Group 4.0%

SF-AXB-MV-2000 Seismic Induced failure of the Aux Building Motor Operat ed Valves Elevation 2000 3.3%

SF-AXB-MV-1974 Seismic Induced Failure ofthe Aux Building Motor Operated Valves Elevation 1974 SF-NSCI 3.0%

Seismic Induced failure ofNon-SC-I SSCs SF-RLOXX 2.9%

Seismic Induced Failure ofthe Main Control Room Board(

s) 2.7%

Sf-AB-SURROG- Auxiliary Building Surrogate Element for Check Valves Elevat 2000

- ion 2000 SF-NSSSSIT 2.5%

Seismic Induced Failure ofthe Accumulator Safety Injection Tanks SF-SCI-PMP 2.0%

Seismic Induced Failure ofthe Class I Safety Pumps 1.9%

SF-FR-YDXFR Seismic rupture of the yard transformer housings, oil leakag e, and subsequent ignition SF-IE-SW 1 .7 /o Seismic Induced failure of service water (NSCI)

Sf-AB-SURROG- 1.6%

Auxiliary Building Surrogate Element for Check Valves Elevat 2026

- ion 2026 1.5%

SF-SBOXX-2 Seismic Induced Failure ofRP Cabinet SB037, SB038, SBO41 SB042 SF-IE-S3 1.5%

Seismic induced very small break LOCA SF-SB 102X <0.1%

Seismic Failure ofW Cabinet for reactor trip switchgear train A/B <0.1%

Relay_0.33 Relay Fragility Group

<0.1%

Page 22 of 25

Attachment 2 to ULNRC-0655 1 Page 23 of 25 4.0 Updated Model Results following all the changes described in Section 2.0, the current S-PRA CDF and LERF risk metric results, and the CDF and LERF fragility rankings are shown below. Note that the risk metric evolution (from peer review, to f&O Closure) are also shown.

SCDF °° Difference  % Difference SLERF (SCDF) (SLERF)

Peçi Review Model 1 .14E-04 5.33E-06 -

f&O Closure Model 4.86E-05 3.4lE-06 57.4% (Decrease) 36.0% (Decrease)

Model Refinements (Post F&O 356E05 3.35E-06 26.8% (Decrease) 1 .8% (Decrease)

Closure)

Model Refinements (Post F&O Closure) CDF Results Hazard HB.A Earthquake Scenario Truncation

. ACUBE ACUBE ACUBE Range Bin Frequency Cutsets CCDP CDF 3/4 CDF

%GO1 0. Ig to O.2g I 8.02E-04 1.OOE-1O 1000 5.60E-05 4.49E-08 0. 1 1%

%G02 O.2g to O.3g 2 1 .80E-04 5.OOE-09 1 000 3. I 3E-03 563E-07 I 42%

%G03 O.3g to O.4g 2 6.48E-05 5.OOE-09 I 000 4.02E-02 2.6 1 E-06 6.59%

%G04 O.4g to O.45g 2 1 .67E-05 5.OOE-09 I 000 1 .70E-O1 2.$3E-06 7.16%

%G05 O.45g to O.5g 2 I 16E-05 1 .OOE-08 I 000 3.32E-O1 3.85E-06 9.74%

%G06 O.5g to O.55g 3 8.13E-06 5.OOE-08 1000 6.72E-O1 5.46E-06 13.83%

%G07 O.55g to O.6g 3 5.87E-06 2.OOE-07 1000 6.95E-O1 4.08E-06 10.32%

%G08 0.6g to 0.7g 4 7.60E-06 5.OOE-07 1000 9.33E-01 7.09E-06 17.94%

%G09 0.7g to 0.8g 4 4.45E-06 5.OOE-07 lt)00 9.63E-01 4.28E-06 10.84%

%G10 > 0.8g 4 8.85E-06 2.OOE-06 1000 9.85E-01 8.71E-06 22.05%

Total SCDF 3.95E-05 Total SCDF (w/PAF) 3.56E-05 Page 23 of 25 to ULNRC-0655 1 Page 24 of 25 Model Refinements (Post F&O Closure)LERF Result s

Hazard JIRA Scenario Earthquake ACUBE ACUBE Truncation.

ACUBE Range Bin Frequency Cutsets CLERP  % LERF LERF

%GO1 O.lgtoO.2g I 8.02E-04 1.OOE-1O 7100 7.97E-07 6.39E-tO O.O2°r

%G02 O2g to O5g 2 2.73E-04 1.OOE-09 7100 547E-05 1.49E-08 040%

%G03 05g to 0.6g 3 1.40E-05 1OOE-09 7100 9.38E-03 1.31E-07 353%

%G04 0.6g to 0.8g 4 1.21E-05 2.OOE-09 7100 3.54E-02 4.28E-07 11.50%

%G05 0.8g to Ig 4 4.49E-06 5.OOE-09 7100 1.41E-01 6.35E-07 17.06%

%G06 lgto 1.2g 4 1.89E-06 1.20E-08 7100 3.47E-01 6.56E-07 17.63%

%G07 L2gto 1.4g 4 1.O1E-06 4.OOE-08 7100 6.02E-01 6.08E-07 16.33%

%G08 1.4g to l.6g 4 5.68E-07 6.OOE-08 7100 7.44E-01 4.22E-07 11.35%

%G09 l.6g to 2g 4 5.29E-07 2.OOE-07 7100 8.89E-01 4.70E-07 12.63%

%GI0 >2g 4 3.63E-07 2.OOE-07 7100 9.79E-01 3.55E-07 9.55%

Total SLERF 3.72E-06 Total SLERF (w/Mf) 3.35E-06 CDF Frai1itv Ranking Fragility Group F Description.

Percent S! IE p j Seismiciuced1ossofoffs;te power Reduction F NNOX Seismic Induced Failure of 120 VAC Distnbubion Panels NNO1 INNO4 SF-SBOXX-2 ;2ic Induc E

1.8%

SF-fR-YDXfR Seismic rupture ofthe yard transformer housings, oil leakag ----

e, and SF-IE-SW Seismic Induced failure ofservice water (NSCI)

SF-NKO2 Seismic Induced Failure of 125 V DC Bus NKO2 J 1.5%

1.5%

LSF-ALHV72O Seismic Induced Failure of ALHOV220Air Operat ed Suction Valve fromIICSTtoTUAFWPumps SF-NGXC-1 1 Seismic Induced Failure ofthe MCC NGO5E and NGO6E J 1.0%

SF-IE-S3 Seismic induced very small break LOCA SF SB1O7X Scismic Failure of W Cabinet for reactor trip switchgear train J <0.1% j MB

<0.1%

RayFtyroup z_ r2iL Page 24 of 25 to ULNRC-0655 1 Page 25 of 25 LERF Frai1itv Ranking Fragility Group Description Percent Reduction F-NS _

c:

i;;; :Lk SF P3 PEN S1smic Iiiduce1&iIure fhØactør Buildmg ,

Centainment Peiietrations giL 1c iqduce1Ioss foter 135%

g3%

SF F AB 2041 F Seismic induced Flooding from Fiie proteciaon piping in Aix z___z SF-CC .

Seismic Induced Failure ofthe Communications Corridor 2.7%

_* InducedFai1ureoftheReactorBui1din Seismic Induced Failure of 120 VAC Distribut L6°o SF-NNOX ion Panels NNO1, NNO2, NNO3 and NNO4 Seismic Induced Failure of RP Cabinet SBO29 1.1%

S F -SBO XX 1 - A BC I),

SBO32ABCD Seismic Induced Failure of 120 VAC Distribut 0.8%

SF-SB 0 XX- 2 ion Panels NNO 1 NNO2, NNO3, and NNO4. ,

MLQ!PQ___ 0.5%

SF-IE-S3 Seismic induced very small break LOCA

<0.1%

FraRankingCoIorKey

[4entdled as risk g1li oentnbutoruiM OR remains toj, eont hbutor Identified as non risk si;ficant contributorm L MORremams nonsigmficantcontnbutor Identified as risk-sgnificant contributor in MOR

, dropEed below 2% threshold.

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