ML14177A086
| ML14177A086 | |
| Person / Time | |
|---|---|
| Site: | Hatch  |
| Issue date: | 06/26/2014 |
| From: | Office of Nuclear Reactor Regulation |
| To: | |
| Balazik M F, NRR/JLD, 415-2856 | |
| References | |
| Download: ML14177A086 (21) | |
Text
Near-term Task Force Recommendation21SeismicRecommendation 2.1 Seismic Hazard EvaluationSouthern June 26, 2014 ReferencesforMeetingReferences for Meeting*Licensee Presentation Slides -ML14176B239*NRC Presentation Slides -ML14177A086*Public Meeting Agenda -ML14169A437MtiFdbkF(tffb@)*Meeting Feedback Form (request from mfb@nrc.gov) *May 9, 2014, NRC letter regarding Seismic Screening and Prioritization Results for central and eastern US Licensees(ML14111A147)*May 21, 2014, NRC memo providing preliminary staff groundmotionresponsespectraforcentralandground motion response spectra for central and eastern Licensees(ML14136A126)*Meeting Summary to be issued within 30-day MeetingIntroductionMeeting IntroductionPurpose: support information exchange and begin dialog to have ddifhfhidiffcommon understanding of the causes of the primary differences between the preliminary NRC and licensee seismic hazard results
Background:
NRCandlicenseeseismichazardrequireresolution
Background:
NRC and licensee seismic hazard require resolution to support a final seismic screening decision and to support related follow-on submittalsOutcomes: *Begin NRC and licensee resolution to support regulatory decisionsanddevelopmentofseismicriskevaluations,asdecisions and development of seismic risk evaluations, as appropriate*Establish resolution path, including timelines and identification of potential information needs Look-ahead:lPotential Next Steps*NRCwillconsiderthemeetinginformationNRC will consider the meeting information*Potential paths:Libitltliftibd-Licensee submits supplemental information based on public meeting dialogNRCstaffissuesarequestforinformation-NRC staff issues a request for information-Licensee sends a revision or supplement to the seismichazardreportseismic hazard report*NRC completes screening review and issues thfilidtitilttthe final screening determination letter HatchUnitsNuclearPlantHatch Units Nuclear PlantSarah TabatabaiOfficeofResearchOffice of ResearchJune 26, 2014
Screening*Screens in: Expedited Approach, Seismic Risk, High Frequency, SFP EvaluationsPiititiG2*Prioritization Group: 20.6Licensee SSE (Unit 1)Licensee SSE (Unit 2)0.40.5tion (g)()Licensee GMRSNRC GMRS (Updated)020.3ctral Accelera0.10.2Spec00.1110100Frequency (Hz)
StratigraphySite Geologic Column (Source: FSAR Figure 2.5-8, Rev. 19)
ControlPointControl PointNRCSSE Control Point El. 129 ftSubmittalSSE Control Point El. 129 ftSSCooo9SSCooo9 VsProfileDevelopmentVsProfile DevelopmentNRCTemplatevelocityprofileforSubmittalISFSIdatausedtodevelopnearTemplate velocity profile for Vs=400 m/s (1312 ft/sec) from SPID used for entire profile.
Template velocity profile supported ISFSI data used to develop near surface Vs profile (i.e. to a depth of 229 ft). Deeper portions of the profile (i.e. below a depth of 509 ft) by Vs data found in the literature were developed with nearby oil well exploration (Vp) data Epistemic Uncertainty in VsProfilesProfilesNRCApplied a scale factor of 1.2 to the SubmittalApplied a scale factor of 1.57 to the ppedascaeacoooebase case profile for development of the upper and lower case profilesppedascaeacoo5oebase case profile for development of the upper and lower case profiles Vs ProfilesShear-Wave Velocity (ft/sec)0500020004000600080001000012000y()05002000400060008000Shear-Wave Velocity (ft/sec)NRC-BCNRC-LBC10001500t)50100150NRC-UBCLicensee-BCLicensee-LBCLicensee-UBC150020002500ontrol Point (ft150200ntrol Point (ft)25003000epth Below Co250300pth Below Con35004000DeNRC-BCNRC-LBCNRC-UBC350400Dep45005000NRCUBCLicensee-BCLicensee-LBCLicensee-UBC450500 00200040006000800010000Shear-Wave Velocity (ft/sec)Hawthorn Fm.TFVs=2450 +/-200 ft/s in upper 50-100 ft(FSAR)Information from other sites:Saxena(2008) Vs=1500 -1900ft/s(HawthornFm)5001000Tampa Fm.Undifferentiated OligoceneOcala Fm. VogtleCOL: Vs=2650 ft/s Parker (2008) Vs=2296 ft/s (Ocala Fm.)1900 ft/s (Hawthorn Fm.)1500nt (ft)Lisbon Fm. TallahataFm. Wilcox GroupClayton Fm.at 149 ft(Lisbon Fm.)Odumet al (2003): Vs=2805 ft/s at 98 ft(WilcoxGroup)20002500w Control PoinPost Tuscaloosa Deposits(Wilcox Group)30003500Depth BelowTuscaloosa Fm.Odumet al (2003): Vs=2840 ft/s at 98 ft35004000NRC-BCUndifferentiated Early Cretaceous Deposits(Tuscaloosa Fm.)45005000NRC-LBCNRC-UBCLicensee-BCPre-Cretaceous Basement Rock 00200040006000800010000Shear-Wave Velocity (ft/sec)5001000An average Poisson's ratio of 1500nt (ft)Lisbon Fm. g0.43 is reported for the Lisbon Formation at the Farley site20002500w Control PoiNRC-BCNRC-LBC3000 3500Depth BeloNRC-UBCLicensee-BC (v=0.25)Licensee-BC (v=0.33)4000Licensee-BC (v=0.45)45005000 Aleatory Uncertainty in VsProfilesNRCSbittlNRC60 Randomizations Using USGS "B"SiteConditionsSubmittal30 Randomizations Using USGS "B""C"and"D"SiteConditionsfor"B" Site Conditions "B", "C", and "D" Site Conditions for the Upper-Range, Median, and Lower-Range Profiles, Respectively ln= 0.25 Upper 50 ft.ln= 0.15 Below 50 ft.ln= 0.25 Upper 90 ft.ln= 0.15 Below 90 ft.
Epistemic Uncertainty in Shear ModulusandDampingCurvesModulus and Damping CurvesNRCM1SubmittalM1M1EPRI Soil: 0 -276 ftEPRI Rock: 276 -500 ft Linear & No Damping: > 500 ftM1Av. of EPRI 50-120 ft& 120-250 ft:
0 -129 ft Av. of EPRI 120-250 ft& 250-500 ft: pgM2Peninsular: 0 -276 ftLinear&1%Damping:276500ft129 -279 ft Idriss& Boulanger Weathered Rock Curves: 279 to 509 ftLinear&KappaBasedDamping:>Linear & 1% Damping: 276 -500 ftLinear & No Damping: > 500 ftLinear & Kappa-Based Damping: > 500 ft Kappa and Epistemic UncertaintyNRCKappawascalculatedforeachSubmittalCalculatedakappadistribution2forKappa was calculated for each base case profile using Q values from Campbell (2009). A ln=0.2 was applied to determine the range Calculated a kappa distribution2for each base case Vs profile based on a median kappa of 0.04 sec (i.e. a deep soil site) and a ln=0.4 of kappasfor each base case profile.Base Case KappasLBC:00571Kappa DistributionkL:0024LBC: 0.057BC: 0.040UBC: 0.030kL: 0.024kM: 0.040kU: 0.0671Imposed an upper limit of 0.04 sec based on the SPID Guidance2Clarification needed Amplification Functionsp56NRC (Input PGA = 0.01 g)NRC (Input PGA = 0.2 g)NRC (Input PGA = 0.5 g)Licensee (Input PGA = 0.01 g)34ficationLicensee (Input PGA = 0.2 g)Licensee (Input PGA = 0.5 g)NRC Sigma (Input PGA = 0.01 g)NRC Sigma (Input PGA = 0.2 g)NRC Sigma (Input PGA = 0.5 g)Licensee Sigma (Input PGA = 0.01 g)23AmplifLicensee Sigma (Input PGA = 0.2 g)Licensee Sigma (Input PGA = 0.5 g)010.1110100Frequency (Hz)
GMRS Comparison10.1tion (g)ectral AcceleratNRC GMRS0.01SpeLicensee GMRSHatch Unit 2 SSEHatch Unit 1 SSE0.0010.1110100Frequency (Hz)Licensee GMRS (NRC Calc.)
PrimaryDifferencesPrimary Differences*Kappa-Southern considered Hatch to be a deep soil site and used a median kappa of 0.04 sec, while the NRC placed an upper limit of 0.04 sec on kappaClassificationasadeepsoilsiteinconsistentwithVs-Classification as a deep soil site inconsistent with Vs base cases*Largedifferencesinshear-wavevelocitiesLarge differences in shearwave velocities below a depth of approximately 500 ftdue toanassumedPoisson'sratioto an assumed Poissons ratio