ML14182A099

July 1, 2014 Public Meeting Slides TVA - NTTF 2.1 - Seismic Reevaluation - GMRS

ML14182A099
Person / Time
Site:	Watts Bar
Issue date:	07/01/2014
From:	Tennessee Valley Authority
To:	Office of Nuclear Reactor Regulation
Balazik M F, NRR/JLD, 415-2856
References
Download: ML14182A099 (40)

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Information ExchangeWBN Seismic Hazard1 Information ExchangeWBN Seismic Hazard*NRC May 9 Prioritization Letter-Seismic Risk Evaluation *Prioritization Group 1-WBN Acknowledges *Prioritization Group 1*Seismic risk evaluation by June 30, 2017

• ESEP -RLGM -2 x SSE*NRC May 21 Support Document-Preliminary graphical representation*NRC staff GMRS differs from Licensee GMRS2 Information ExchangeWBN Seismic HazardEPRIMaximum:0.77g@15HzNRCMaximum:0.98@30Hz3 Information ExchangeWBN Seismic Hazard*WBNunderstandingofthecausesoftheprimarydifferencesbetweenthepreliminaryNRCandlicenseeresults.*ElementsofNRCstaffpreliminaryassessment*FSARprimarysourceforinformationonsubsurfacematerials-narrowervelocityprofile>>4,500fpslower>>6,500fpsupper-Hardrockat1,000ft.*UseofEPRIrockcurvesandlowstraindampingvalues*KappaValuesandweights4 Information ExchangeWBN Seismic Hazard*WBNadditionaldataforsubsurfacematerials*Expandsitegeologicprofileduetocurrentunderstandingofhardrockcharacteristics-shearwavevelocity>9200fps.*Reduceuncertaintythroughoutprofiletobasement>10,000ft.*SupportEPRIGMRSDevelopment*SupportDevelopmentofSeismicHazardinputforSPRA5 Information ExchangeWBN Seismic Hazard*UtilizedAcademic/IndustryExpertise-AMEC-ProgramManagement;regional/localgeology-Dr.RobertHatcher,ProfessorofGeology,UniversityofTennessee-Knoxville>>Regional/localgeology-Dr.KenStokoe,ProfessorofCivilEngineering,UniversityofTexas-Austin>>SpectraAnalysisSurfaceWave(SASW)Survey>>RockTesting-IvanWong(URS)and>>SeismicHazard&EvaluationofSASW/RockTesting-WaltSilva(PE&A)>>SiteModeling/Characterization-FacilityRiskConsultants>>3rdpartyseismicconsultantreview6 Information ExchangeWBN Seismic HazardSource:AMEC(2013)7 Information ExchangeWBN Seismic Hazard8 InformationExchangeWBN Seismic Hazard9 Information ExchangeWBN Seismic Hazard10 Information ExchangeWBN Seismic Hazard*SASWSurvey(8testsites)-Sites6&7profileddepthsofapprox.1400'and1700'-SASWTeambelievesresultsfromSite8wouldhavebeensimilarhadsufficientlateralspacebeenavailableforalongersurveyline.-Achievingprofiledepthsof14001700'isuncommonlygoodresultsforSASWsurvey!*RockTesting-6IntactRockCores(URCfreefreeunconfinedresonantcolumntests)-PumpkinValleyShale(2),ConsaugaMiddle,PondSpringsFormation,NolichuckyShale,andRomeFormation11 Information ExchangeWBN Seismic HazardSource:AMEC(2013)12 Information ExchangeWBN Seismic Hazard*BenefitsDerivedfromSASWSurvey/RockTesting-Providedshearwavevelocitydataforimportantgeologicformationsbeneaththesite-Capturedthevariabilityinshearwavevelocitybeneaththesite-Providedsitespecificmeasurementswhichreducedtheepistemicuncertaintyintheprofiles(1.25whereappropriate)-Demonstratesthatassumptionsofshearwavevelocitiesfromthetypeofrockwouldhavebeenmisleading.Forexample,itwassurprisingthattheRomesandstonewasasfastasitwasandthedolomiteslowerthanwasthought.Nosubstituteforrealdata!-SASWmeasurementswereperformedtoadepthupto1700ftrightnexttothereactor,someofthedeepestmeasurementstakeninthecentralandeasternUS.13 Information ExchangeWBN Seismic HazardFigure2.3.21ShearwavevelocityprofilesforWattsBarNuclearPlant(EPRI,2014)BaseCase600'LowerBound600'UpperBound592'UpperBound936'LowerBound936'BaseCase936'14 Information ExchangeWBN Seismic Hazard*DevelopmentOfTotalEffectiveKappa-FollowingSPIDGuidelinesForFirmRockProfile<3,000ftDeep-TotalEffectiveKappaBasedonFirmRockDampingof1.25%(QS=40)-PlusHardRockContribution0.006s*UncertaintyInDepthToHardRockAccommodatedWithTwoMeanDepths600ft,900ft-ResultsInSixKappaEstimatesForBaseCase,UpperRange,LowerRangeProfilesandTwoDepthstoHardRock15 Information ExchangeWBN Seismic Hazard*EpistemicUncertaintyInBaseCaseVSProfilesOf1.25ResultsInNarrowRangeOfKappa-FollowingSPIDGuidelines,EpistemicUncertaintyInKappaTakenasln0.4AboutMeanEstimate-ShallowProfile0.012s+/-,range0.007sto0.020s-DeepProfile0.013s+/-,range0.008sto0.022s16 Information ExchangeWBN Seismic Hazard*Summary-WattsBardevelopedasignificantlyenhancedsitegeologicalprofiletosupportsitecharacterization-SupplementedbySASWsurveytoprovideadditionalclarityforstrataaboveTopofHardRock-AccountsforvariationinthetopoftheRomeFormationunderlyingWBN-Rocktestingof6intactcorestodetermineparametersforsitecharacterization-SitecharacterizationandEPRIGMRSperformedinconformancewithSPIDandisappropriatecharacterizationofseismichazardforWattsBarsite.17 Information ExchangeSQN Seismic Hazard1 Information ExchangeSQN Seismic Hazard*NRC May 9 Prioritization Letter-Seismic Risk Evaluation *Prioritization Group 2-SQN Acknowledges *Prioritization Group 2*Seismic risk evaluation by December 31, 2019

• ESEP -RLGM = 2 x SSE*NRC May 21 Support Document-Preliminary graphical representation*NRC staff GMRS differs from Licensee GMRS2 Information ExchangeSQN Seismic HazardEPRIMaximumSA:0.76g@20HzNRCMaximumSA:0.84g@40Hz3 Information ExchangeSQN Seismic Hazard*SQNunderstandingofthecausesoftheprimarydifferencesbetweenthepreliminaryNRCandlicenseeresults.*ElementsofNRCstaffpreliminaryassessment*Velocityprofile*UseofEPRIrockcurvesandlowstraindampingvalues*KappaValuesandweights4 Information ExchangeSQN Seismic Hazard*SQNadditionaldataforsubsurfacematerials*Expandsitegeologicprofileduetocurrentunderstandingofhardrockcharacteristics-shearwavevelocity>9200fps.*FSARhadlimitedrockcharacteristicsdataavailableatdepth(>103ft)*Definitionofrockprofiletobasement12,000ft.*SupportEPRIGMRSDevelopment5 Information ExchangeSQN Seismic Hazard*UtilizedAcademic/IndustryExpertise-AMEC-ProgramManagement;regional/localgeology-Dr.RobertHatcher,ProfessorofGeology,UniversityofTennessee-Knoxville>>Regional/localgeology-Dr.KenStokoe,ProfessorofCivilEngineering,UniversityofTexas-Austin>>SpectraAnalysisSurfaceWave(SASW)Survey@WBN>>RockTesting-IvanWong(URS)>>SiteModeling/Characterization6 Information ExchangeSQN Seismic HazardSource:AMEC(2013)7 Information ExchangeSQN Seismic HazardFigure2.3.21ShearwavevelocityprofilesforSequoyahNuclearPlant(EPRI,2014)0500100015002000250030003500400045005000550060006500010002000300040005000600070008000900010000Depth(ft)Vs(ft/sec)VsprofilesforSequoyahSiteProfile1Profile2Profile3BaseCaseLowerBoundUpperBound8 Information ExchangeSQN Seismic Hazard*DevelopmentofTotalEffectiveKappa*FollowingSPIDGuidelinesForFirmRockProfile>3,000ftDeep-TotalEffectiveKappaBasedonAvg.VSoverTop100ft,SurfaceOutcrop-P16,000ft/s,0.012s-P23,821ft/s,0.020s-P39,285ft/s,0.006sHardRock-LikelyConservative(low),0to40ftSoil,NoWeatheredZone*Range0.006sto0.020sConsideredSufficientExpressionOfEpistemicUncertainty9 Information ExchangeSQN Seismic Hazard*Summary-Sequoyahdevelopedanenhancedsitegeologicalprofile*Supplementedbyregionalgeologymaps,industryexperts,andnearbySASWsurveys-EPRIGMRSandsitecharacterizationperformedinconformancewithSPIDandisappropriatecharacterizationofseismichazardforSequoyahsite.10 Information ExchangeBFN Seismic Hazard11 Information ExchangeBFN Seismic Hazard*NRC May 9 Prioritization Letter-Seismic Risk Evaluation *Prioritization Group 2*NRC May 21 Support Document-Preliminary graphical representation*NRC staff GMRS differs from Licensee GMRS12 Information ExchangeBFN Seismic HazardLicenseeMaximumSA:

0.58g@25HzNRCMaximumSA:0.68g@40Hz13 Information ExchangeBFN Seismic Hazard*BFNunderstandingofthecausesoftheprimarydifferencesbetweenthepreliminaryNRCandlicenseeresults.*ElementsofNRCstaffpreliminaryassessment*Narrowervelocityprofile-7,000fpslowerbound-9,285fpsupperbound(hardrock)*UseofEPRIrockcurvesandlowstraindampingvalues*KappaValuesandweights14 Information ExchangeBFN Seismic Hazard*BFNadditionaldataforsubsurfacematerials*Expandsitegeologicprofileduetocurrentunderstandingofhardrockcharacteristics-shearwavevelocity>9200fps.*FSARhadlimitedrockcharacteristicsdataavailableatdepth(>200ft)*Definitionofrockprofiletobasement5,000ft.*SupportEPRIGMRSDevelopment15 Information ExchangeBFN Seismic Hazard*UtilizedAcademic/IndustryExpertise-AMEC-ProgramManagement;regional/localgeology-Dr.RobertHatcher,ProfessorofGeology,UniversityofTennessee-Knoxville>>Regional/localgeology-Dr.KenStokoe,ProfessorofCivilEngineering,UniversityofTexas-Austin>>SpectraAnalysisSurfaceWave(SASW)Survey@WBN>>RockTesting-IvanWong(URS)>>SiteModeling/Characterization16 Information ExchangeBFN Seismic HazardSource:AMEC(2013)17 Information ExchangeBFN Seismic HazardFigure2.3.21ShearwavevelocityprofilesforBrownsFerryNuclearPlant(EPRI,2014)VsprofilesforBrownsFerrySiteBaseCaseLowerBoundUpperBound18 Information ExchangeBFN Seismic Hazard*DevelopmentofTotalEffectiveKappa*FollowingSPIDGuidelinesForFirmRockProfile>3,000ftDeep-TotalEffectiveKappaBasedonAvg.VsOverTop100ft,surfaceoutcrop-ProfilesP1,P3HardRockNearSurface,=0.006s-ProfileP2Vs(100ft)5,914ft/s,=0.012s-LikelyConservative(low),0to50ftSoil,NoWeatheredZone*Range0.006sto0.012sConsideredSufficientExpressionofEpistemicUncertainty19 Information ExchangeBFN Seismic Hazard*Summary-BrownsFerrydevelopedanenhancedsitegeologicalprofile*Supplementedbyregionalgeologymapsandindustryexperts-EPRIGMRSandsitecharacterizationperformedinconformancewithSPIDandisappropriatecharacterizationofseismichazardforBrownsFerrysite.20 BFN Seismic Risk Evaluation Screening Results21

• BFNunderstandstheIPEEEevaluationdidnotmeetNRCstaffsexpectationforscreeningpurposes-Prerequisite #3-Adequacy Demonstration #3*BFN adequacy review acknowledged the SER identified weakness and provided justification for addressing the weakness as part of the ESEP*BFNhassubsequentlycompletedseismiccapacityevaluationsfortheadditionalRCICcomponents-Minimum HCLPF > 0.50g Information ExchangeBFN Seismic Hazard*Additional information-BFN reevaluated minimum HCLPF SSC (Auxiliary Diesel Generator Transformers)*HCLPF > 0.30g in current configuration and replacement configuration*BFN commitment to complete transformer replacement by Sept 30, 2014 to resolve PCB/IPEEE screening capacity *TVA requests that the NRC staff reconsider the May 9, 2014 screening result that BFN screens in for seismic risk evaluation