ML17334B468

Evaluation of PTS for DC Cook Unit 2.

ML17334B468
Person / Time
Site:	Cook
Issue date:	02/28/1993
From:	CHICOTS J M, MEYER T A WESTINGHOUSE ELECTRIC COMPANY, DIV OF CBS CORP.
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ML17331A266	List: ML17331A265 ML17334B468
References
WCAP-13517, NUDOCS 9304150164
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~vvWCAP-13517WESTINGHOUSEPROPRIETARYCLASS3ATTAc//gEwlgEVALUATIONOFPRESSURIZEDTHERMALSHOCKFORD.C.COOKUNIT2J.M.ChicotFebruary199AMERICANELECTRICPOWERSERVICECORPORATIONAPPROVEDINGENERAL0APPROVEDEXCEPTASNOTEDE3NOTAPPROVED0FORREFERENCEONLYBYm'rikd~DATEWorkPerformedUnderShopOrderAFFP-108PreparedbyWestinghouseElectricCorporationfortheIndianaMichiganPowerCompanyApprovedby:T.A.Meyer,ManagerStructuralReliability8PlantLifeOptimizationWESTINGHOUSEELECTRICCORPORATIONNuclearandAdvancedTechnologyDivisionP.O.Box355Pittsburgh,Pennsylvania15230-035541993WestinghouseElectricCorporationAllRightsReserved TableofContentsListofTablesListofFiguresTABLEOFCONTENTS~PaeIntroductionPressurizedThermalShockMethodsofCalculationofRTPTSVerificationofPlant-SpecificMaterialPropertiesNeutronFluenceValuesDeterminationofRTPTSValuesforAllBeltlineRegionMaterialsConclusionsReferences13 TableLISTOFTABLESTitlePacae1.D.C.CookUnit2ReactorVesselBeltlineRegionHaterialProperties2;NeutronExposureProjectionsatKeyLocationsintheD.C.CookUnit2PressureVesselClad/BaseHetalInterfacefor8.65and32EFPY3.CalculationofChemistryFactorsUsingD.C.CookUnit2SurveillanceCapsuleData104.RTPTSValuesforD.C.CookUnit2for8.65EFPY5.RTPTSValuesforD.C.CookUnit2for32EFPY12~iciureLISTOFFIGURESTitle~Pae1.IdentificationandLocationofBeltlineRegionHaterialsfortheD.C.CookUnit2ReactorVesselN2.RTPTSversusFluenceCurvesforD.C.CookUnit2LimitingHaterials-IntermediateShellPlate,C5556-213 INTRODUCTIONAlimitingconditiononreactorvesselintegrityknownasPressurizedThermalShock(PTS)mayoccurduringaseveresystemtransientsuchasaLoss-Of-Coolant-Accident(LOCA)orasteamlinebreak.Suchtransientsmaychallengetheintegrityofareactorvesselunderthefollowingconditions:severeovercoolingoftheinsidesurfaceofthevesselwallfollowedbyhighrepressurization;significantdegradationofvesselmaterialtoughnesscausedbyradiationembrittlement;andthepresenceofacritical-sizedefectinthevesselwall.In1985theNuclearRegulatoryCommission(NRC)issueda=formalrulingonPTS.Itestablishedscreeningcriteriaonpressurizedwaterreactor(PWR)vesselembrittlementasmeasuredbythenil-ductilityreferencetemperature,termedRTPTS.RTPTSscreeningvaluesweresetfor[$1beltlineaxialwelds,forgingsorplatesandforbeltlinecircumferentialweldseamsforend-of-licenseplantoperation.Thescreeningcriteriaweredeterminedusingconservativefracturemechanicsanalysistechniques.AllPWRvesselsintheUnitedStateshavebeenrequiredtoevaluatevesselembrittlementinaccordancewiththecriteriathroughend-of-license.TheNRChasamendeditsregulationsforlightwaternuclearpowerplantstochangetheprocedureforcalculatingradiationembrittlement.TherevisedPTSRulewaspublishedintheFederalRegister,May15,1991withaneffectivedateofJune14,1991~~.ThisamendmentmakestheprocedureforcalculatingRTPTSvaluesconsistentwiththemethodsgiveninRegulatoryGuide1.99,Revision'~~.

ThepurposeofthisreportistodeterminetheRTPTSvaluesforthe0.C.CookUnit2reactorvesseltoaddresstherevisedPTSRule.Section2discussestheRuleanditsrequirements.Section3providesthemethodologyforcalculatingRTPTS.Section4providesthereactorvesselbeltlineregionmaterialpropertiesforthe0.C.CookUnit2reactorvessel.TheneutronfluencevaluesusedinthisanalysisarepresentedinSection5.TheresultsoftheRTPTScalculationsarepresentedinSection6.TheconclusionsandreferencesforthePTSevaluationfollowinSections7and8,respectively.2.PRESSURIZEDTHERMALSHOCKThePTSRulerequiresthatthePTSsubmittalbeupdatedwhenevertherearechangesincoreloadings,surveillancemeasurementsorotherinformationthatindicatesasignificantchangeinprojectedRTPTSvalues.TheRuleoutlinesregulationstoaddressthepotentialforPTSeventsonpressurizedwaterreactorvesselsinnuclearpowerplantsthatareoperatedwithalicensefromtheUnitedStatesNuclearRegulatoryCommission(USNRC).PTSeventshavebeenshownfromoperatingexperiencetobetransientsthatresultinarapidandseverecooldownintheprimarysystemcoincidentwithahighorincreasingprimarysystempressure.ThePTSconcernarisesifoneofthesetransientsactsonthebeltlineregionofareactorvesselwhereareducedfractureresistanceexistsbecauseofneutronirradiation.Suchaneventmayresultinthepropagationofflawspostulatedtoexistneartheinnerwallsurface,therebypotentiallyaffectingtheintegrityofthevessel.TheRuleestablishesthefollowingrequirementsforalldomestic,operatingPMRs:*AllplantsmustsubmitprojectedvaluesofRTpTSforreactorvesselbeltlinematerialsbygivingvaluesfortimeofsubmittal,theexpirationdateoftheoperatinglicense,andtheprojectedexpirationdateifachangeintheoperatinglicenseorrenewalhasbeenrequested.ThisassessmentmustbesubmittedwithinsixmonthsaftertheeffectivedateofthisRuleifthevalueofRTPTSforanymaterialisprojectedtoexceedthescreeningcriteria.

Otherwise,itmustbesubmittedwiththenextupdateofthepressure-temperaturelimits,orthenextreactorvesselsurveillancecapsulereport,orwithin5yearsfromtheeffectivedateofthisRulechange,whichevercomesfirst.Thesevaluesmustbecalculatedbasedonthemethodologyspecifiedinthisrule.Thesubmittalmustincludethefollowing:I)thebasesfortheprojection(includinganyassumptionsregardingcoreloadingpatterns),and2)copperandnickelcontentandfluencevaluesusedinthecalculationsforeachbeltlinematerial.(IfthesevaluesdifferfromthosepreviouslysubmittedtotheNRC,'justificationmustbeprovided.)*TheRTPTS(measureoffractureresistance)screeningcriteria'forthereactorvesselbeltlineregionis270'Ffor,plates,forgings,axialwelds;and,300Fforcircumferentialweldmaterials.*ThefollowingequationsmustbeusedtocalculatetheRTPTSvaluesforeachweld,.plateorforginginthereactorvesselbeltline:EquationI:RTPTSI+H+hRTPTSEquation2:hRTPTS(CF)f(0.28-0.10logf)*AllvaluesofRTPTSmustbeverifiedtobeboundingvaluesforthespecificreactorvessel.Indoingthiseachplantshouldconsiderplant-specificinformationthatcouldaffectthelevelofembrittlement.*Plant-specificPTSsafetyanalysesarerequiredbeforeaplantiswithin3yearsofreachingthescreeningcriteria,including.analyses'falternativestominimizethePTSconcern.*NRCapprovalforoperationbeyondthescreeningcriteriaisrequired.

3~METHODFORCALCULATIONOFRTPTSInthePTSRule,theNRCStaffhasselectedaconservativeanduniformmethodfordeterminingplant-specificvaluesofRTPTSatagiventime.Forthepurposeofcomparisonwiththescreeningcriteria,thevalueofRTPTSforthereactorvesselmustbecalculatedforeachweldandplateorforginginthe.beltlineregionasfollows.RTPTS+H+~PTSwherehRTPTS(CF)f('Initialreferencetemperature(RTNDT)in'FoftheunirradiatedmaterialMMargintobeaddedtocoveruncertaintiesinthevaluesofinitialRTNDT,copperan'dnickelcontents,fluencearidcalculationalprocedures.H-66'Fforweldsand48'FforbasemetalifgenericvaluesofIareused.H=56'Fforweldsand34'FforbasemetalifmeasuredvaluesofIareused.fNeutronfluence,n/cm2(E>1HeVattheclad/basemetalinterface),dividedby10CFChemistryfactorfromtables~2~forweldsandforbasemetal(platesandforgings).Ifplant-specificsurveillancedatahasbeendeemedcredibleperReg.Guide1.99,Rev.2~~,itmaybeconsideredinthecalculationofthechemistryfactor.

VERIFICATIONOFPLANT-SPECIFICHATERIALPROPERTIESBeforeperformingthepressurizedthermalshockevaluation,areviewofthelatestplant-specificmaterialpropertieswasperformed.ThebeltlineregionisdefinedbythePTSRule~2~tobe"theregionofthereactorvessel(shellmaterialincludingwelds,heataffectedzonesandplatesorforgings)thatdirectlysurroundstheeffectiveheightoftheactivecoreandadjacentregionsofthereactorvesselthatarepredictedtoexperiencesufficientneutronirradiationdamagetobe'onsideredintheselectionofthemostlimitingmaterialwithregardtoradiationdamage."FigureIidentifiesandindicatesthelocationofallbeltlineregionmaterialsfortheD.C.CookUnit2reactorvessel.Haterialpropertyvalueswereobtainedfrommaterialtestcertificationsfromtheoriginalfabricationaswellastheadditionalmaterialchemistrytestsperformedaspartofthesurveillancecapsuleprogram~~.Theaveragecopperandnickelvalueswerecalculatedforeachofthebeltlineregionmaterialsusingalltheavailablematerialchemistryinformation.AsummaryofthepertinentchemicalandmechanicalpropertiesofthebeltlineregionplateandweldmaterialsoftheD.C.CookUnit2reactorvesselaregiveninTablel.AlloftheinitialRTNDTvalues(I-RTNDT)arealsopresentedinTablel.

C5521-24JICiVJCZ!LalI27010'8010'0'5556-2CORE0~C5540-2270'0'CC)180'5592-1Figurel.IdentificationandLocationofBeltlineRegionMaterialsfortheD.C.CookUnit2ReactorVessel I

TABLE1D.C.COOKUNIT2REACTORVESSELBELTLINEREGIONMATERIALPROPERTIESMaterialDescriptionCU(>)NI(%%d)I-RTNDT('F)IntermediateShell,C5556-20.15IntermediateShell,C5521-2*0.1250.570.585838LowerShell,C5540-2LowerShell,C5592-1Longitudinal'elds*CircumferentialWeld*0.110.140.0520.0520.640.590.9670.967-20-20-35-35*MeanvaluesofcopperandnickelasindicatedbelowMaterialPlate,C5521-2DataSourceOriginalHillTestReportSurveillanceProgram[5]MeanvalueCopper~wt.t',0.14O.ll0.125Nickel~wt.I0.580.580.58WeldOriginalMillTestReportSurveillanceProgram[5]SurveillanceProgram[5]Meanvalue0.050.0550.050.970.970.960.0520.967 5.NEUTRONFLUENCEVALUESThecalculatedfastneutronfluence(E>1MeV)attheinnersurfaceoftheD.C.CookUnit2reactorvesselisshowninTable2.ThesevalueswereprojectedusingtheresultsoftheCapsuleUradiationsurveillanceprogram~"~.TABLE2NEUTRONEXPOSUREPROJECTIONS*ATKEYLOCATIONSINTHED.C.COOKUNIT2PRESSUREVESSELCLAD/BASEMETALINTERFACEFOR8.65AND32EFPY[IEFPY8.65320~0.1790.66310'.2440.90230'.3091.140.4651.71*F1uencex10n/cm(E>1.0MeV)

6.DETERMINATIONOFRTPTSVALUESFORALL8ELTLINEREGIONMATERIALSUsingtheprescribedPTSRulemethodology,RTPTSvaluesweregeneratedforallbeltlineregionmaterialsofthe0.C.CookUnit2reactorvesselasafunctionofpresenttime(8.65EFPYperCapsuleUanalysis)andend-of-license32EFPY)fluencevalues.Thefluencedataweregeneratedbasedonthemostrecentsutveillancecapsuleprogramresults~"~.ThePTSRulerequiresthateachplantassesstheRTPTSvaluesbasedonplantspecificsurveillancecapsuledataundercertainconditions.Theseconditionsare:PlantspecificsurveillancedatahasbeendeemedcredibleasdefinedinRegulatoryGuide1.99,Revision2,andRTPTSvalueschangesignificantly.(ChangestoRTPTSvaluesareconsideredsignificantifthevaluedeterminedwithRTPTSequations(I)and(2),orthatusingcapsuledata,orboth,exceedthescreeningcriteriapriortotheexpirationoftheoperatinglicense,includinganyrenewedterm,ifapplicable,fortheplant.)ForD.C.CookUnit2,theuseofplantspecificsurveillancecapsuledataarisesfortheintermediateshellplate,C5521-2andtheweldsbecauseofthefollowingreasons:I)Therehavebeenthreecapsulesremovedfromthereactorvessel,andthedataisdeemedcredibleperRegulatoryGuide1.99,Revision2.2)Thesurveillancecapsulematerialsarerepresentativeoftheactualvesselmaterials.Thechemistryfactorsfortheintermediateshellplate,C5521-2andweldswerecalculatedusingthesurveillancecapsuledataasshowninTable3.AllotherchemistryfactorvaluesfortheremainingbeltlinematerialswerecalculatedusingtheTablesIand2fromRegulatoryGuide1.99,Revision2.

TABLE3CALCULATIONOFCHEMISTRYFACTORSUSINGD.C.COOKUNIT2SURVEILLANCECAPSULEDATA~~CarponentCaPsuleFLuenceFFDRTNDTFPDRTNDT(FF)"2IntermediateShellPLateC5521-2(Long.)intermediateShellPlateC5521-2(Trans.)0.2640.6831.061.580.2640.6831.061.580.6380.8931.0161.1260.63S0.8931.0161.126559095958010010313835.07280.37896.548107.00451.01389.309104.679155.4380.4070.7981.0331.2690.4070.7981.0331.269719.4427.012ChemistryFactor~719.442/7.012i102.61MeldMetalT0.2640.638'T0.6830.893X1.061.016U1.581.1264050707525.50744.65571.14184.4770.4070.7981.0331.269225.7793.506ChemistryFactor~225.779/3.506~64.40 Tables4and5provideasummaryoftheRTPTSvaluesforallbeltlineregionmaterialsfor8.65EFPYandend-of-life(32EFPY),respectively,usingthePTSRule.TABLE4RTPTSVALUESFORD.C.COOKUNIT2FOR8.65EFPYHaterialhRTgpT('F)+InitialRTNOT+Ha>ginRTPTS(CFxFF*)('F)('F)(F)IntermediateShellPlate,C5556-2IntermediateShell.Plate,C5521-2LowerShellPlate,C5540-2LowerShellPlate,C5592-1IntermediateShellLongitudinalWeldsLowerShellLongitudinalWeldsCircumferentialMeldSeam108.350.78786.500.787(102.61)0.78774.600.78799.550.78770.80'0.618(64.40)0.61870.800.543(64.40)0.54370.800.787(64.40)0.787583838-20-20-35-35-35-35-35-353434343434565656565656177140(153)7392656160567772()Indicatesnumberswerecalculatedusingsurveillancecapsuledata.*Fluencefactorbaseduponpeakinnersurfaceneutron.fluenceof4.65x10n/cm[4],exceptforthelongitudinalwelds.Fortheintermediateshelllongitudinalwelds,thefluencefactorisbasedona,neutronfluenceof2.44x10n/cm[4]attheinnersurfaceoftheweldatthe10'ocation.Forthelowershelllongitudinalwelds,thefluencefactorisbasedonaneutronfluenceof1.79x10n/cm[4]attheinnersurfaceoftheweldatthe0'ocation.

P0 TABLE5RTPTSVALUESfORD.C.COOKUNIT2FOR32EFPYMaterialhRTNDT('F)'InitialRTNDT+(CFxFF*)('F)MarginRTPTS('F)('F)IntermediateShellPlate,C5556-2IntermediateShellPlate,C5521-2LowerShellPlate,C5540-2LowerShellPlate,C5592-1Intermediate.ShellLongitudinalWelds108.351.14886.501.148(102.61)1.14874.601.14899.551.14870.800.971(64.40)0.971583838-20-20-35-353434345656216171(190)1001289085LowerShellLongitudinalWeldsCircumferentialWeldSeam70.80(64.40)70;80(64.40)0.8850.8851.1481.148-35-35-35-3556565656847810295()Indicatesnumberswerecalculatedusingsurveillancecapsuledata.*Fluencefactorbaseduponpeakinnersurfaceneutronfluenceof1.71x10n/cm[4],exceptforthelongitudinalwelds.Fortheintermediateshelllongitudinalwelds,thefluencefactorisbasedonaneutronfluenceof9.02x10n/cm[4]attheinnersurfaceoftheweldatthe10location.Forthelowershelllongitudinalwelds,thefluencefactorisbasedonaneutronfluenceof6.63x10n/cm[4]attheinnersurfaceoftheweldatthe0'ocation.

gl7.CONCLUSIONSIAsshownsnTables4and5,alltheRTPTSvaluesremainbelowtheNRCscreeningvaluesforPTSusingthefluencevaluesforthepresenttime(8.65EFPY)andtheprojectedfluencevaluesfortheend-of-life(32EFPY).AplotoftheRTPTSvaluesversusthefluenceisshowninFigure2forthemostlimitingmaterial,theintermediateshellplate,C5556-2intheD.C.CookUnit2reactorvesselbeltlineregion.300250200LI0M150t-CLCC100SCREENINGCRITERIA~~~~~~~~~~~~~~~0~~~~~~~....k"~~~~~~~~~~~~~.0'"~~~~~~~~~~~~~~~~508.65EFPY432EFPY1E+182E+'I83E+185E+181E+192E+193E+195E+19FLUENCE(NEUTRONS/CM)INTER.SHELLPIATE,C5556-21E+20Figure2.RTPTSversusFluenceCurvesforD.C.CookUnit2LimitingMaterial-IntermediateShellPlate,C5556-2 eglJ REFERENCES[1]10CFRPart50,"AnalysisofPotentialPressurizedThermalShockEvents,"July23,1985.[2]10CFRPart50,"FractureToughnessRequirementsforProtectionAgainstPressurizedThermalShockEvents,"May15,1991.(PTSRule)[3]RegulatoryGuide1.99,Revision2,"RadiationEmbrittlementofReactorVesselMaterials,"U.S.NuclearRegulatoryCommission,May1988.[4]WCAP-13515,"AnalysisofCapsuleUfromtheIndianaMichiganPowerCompanyD.C.CookUnit2ReactorVesselRadiationSurveillanceProgram,"page6-28,J.M.Chicots,etal.,October1992.(WestinghouseProprietaryClass3)[5]WCAP-8512,"AmericanElectricPowerCompanyDonaldC.CookUnitNo.2ReactorVesselRadiationSurveillanceProgram",J.A.Davidson,etal.,November1975.[6]MT/SMART-090(89),"D.C.CookUnit2ReactorVesselHeatupandCooldownLimitCurvesforNormalOperation",N.K.Ray,April1989,Tablel.

ENCLOSURE2TOAEP:NRC:1173CMARKUPOFPRESSURIZEDTHERMALSHOCKANDUPPERSHELFENERGYSUMMARYTABLES Enclosure.2toAEP:NRCall73"SucTRaryFileforPressurizedTheraalShackPLantNaaa0CCock1EOLa}0/25/2014$eltL}rident.Na-LeShell$445Mat"LeShelL$4405.2Mc-LeShelL$4'053MeetXc.ident.C3$n}0XeutfLuenceat.ER/EFPT1ehkfc&l.lOc181ehhakh0'4'FiLO'E}g~9840-F1I}OE}9XethcdofOetarein.}RTXTEXS-ZXtaS-2NTH5.ZthaaiatryfactorXechadofDeterge}nCFTableTabLeTable0.140.}40.460.'50.4Sint.SheLL~>>-Iint.SheLL$4'06-2int.Shell$4406-3LeverShelL$44071LoverSheLL5447.2LoverSheLL$4407.31.41E191.41E191.41E191.4}E19141E191.41E19SOP33'F40'F'2$'F-1Z'F3S'FPlantSaecificPlantScecificPlantSoecificPlantSpecificPlantSpecificPlantSpecific$1.4104,5102.9495.5TabL~Tabl~CalmlatadTableTab'LeTable0.120.150.150.140120140.520.500.490550.590.50Xa='.eSheL}.AxialVeLda1-4-2A1(.'c-'.e/int.ShelLC}rc.Velds-c'z13Z53and12OCS(T)202918.56'F1.NK15-56'Fi'0'E1$CenericCeneric206,4TableTableD,ZS0.350.7>>O.i>>tpLnttoLoverShellCirc.Veld9-4'21P35711.4}E19'-56'FCeneric219TableQ.7'n.ShelLAxialVe}d2-4'A/CLoverShellAxialVeld3-4'ZA/C13Z53120~&(T)13Z53and12OCS(T)56'FOqor=14~QZ-S&F0clcj,1RCcnericCenericZO&.4206.4TableTableQe278' SumitaryFileforPressurizedTheraalShockPlantNaekeBeltlineIdent.HeatNoIdent.IONeut.FLuenceatEOLIEFPTIRTHethodofOetenafn.IRTChosistryFactorH<<thodofOetanafn.CFC.C.Caak'IALLdataexceptaanotedbelowwrefreretheJulyG,1992LetterfrereE.E.Ffapatrfck:toT.E.Hurley,"OanaLdC.CookNuclearPLantUnits1and2...genericI.atter92-0t,Revfaian1,ReactarVesselgtruceuaLIntegrity."InformationregardingchersfcaLccapoaftfcn,initialRT,andaethodalagyofdetemfnatfanfarthelIJSEfor'hewidearefreretheNovedaer29,1993LetterfreeE.E.FfttpatrfcktoT.E.Hurley,eganaldC.CookNuclearplantUnits1ard2...ResponsetaRequestforNitfanalInfonaatianfargenerfcletter92-OtRevisicnt."NovaluefarICuafveld5-442@aspravided,thereforethedefaultvalueof0.35NasUsed.DatLd, SumaryFileforPressurizedThermalShockPlantXaaaO.C.Cook2EOL:12/23/2017Beltlfneident.int.SheLL10-1int.Shell10-2LrwerShell9-1Lo~erSheLL9-2int.ShelLAxialVeldsL~rShellAxial'MeldsCfrcus.'MeldHeatXo.ident.C5556-205521-2C55402C5592-153986S398610Xeut.FluenceatEOLIEFPY'1.71E191.71E19~~0<iViEl+9.0ZE186.63E18171E1958'F'8'F20'F20'F-35'F.35'F-35'FXethodofOeterain.LRTPlantSoecificPlantSpecificPlantSpecificPlantSpecificPlantSpecificPlantSpecificPlantSoecificChemistryFactor108.910Z.6174.664.464.4methodofOeterain.CFTableCalculatedTableTabl~CalculatedCaLculatedCalculated0.15O.LZ,S0.110.140.050.050.050.$)0.580.640.970.970.97~RAinitiaLRTandchcceicsLccapositicnfortheplatesandarefreetheJuly13,1992letterfrommE.E...Fit~tricktoT.E.Hurley,"OcnaldC.CookXuclearPlantUnits1arxl2...GenericLetter92-01,Revision1,ReactorVesselS'tructuraLintegrity."Updatedflvences,chemicalccaposition,initialRT,andcalculatedchesistryfactorsarefreetheApril12,1993letterfrcceE.E.Fit-patricktoT.E:Hurley,CcnaldC.CookXu=learplantUnitZ...UpdatedReferenceTeeperaureandPressurizedThe~iShockAnalyses."

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~~~i)1l~~%~~C~TC',.'~eL,I,,~~4'C',,~RtWRSl%tI8 SLfmflaryFileforUpperShelfEnergyPLantNateBeltlfneident.HeatNo.Natarial1/4TUSEacEOL1/4TXeutranFluenceatEOLUnirred.USEHethadofDetermfn.Unirrad.USE~RfoneD.C.CaakLAlldata'xŽcaptasnotedbalanuerefrcatheJuly13,1992LetterfreeE.E.FlttpatrfcktaT.E.Hurley,49onaldC.CookNuclearPlantUnits,'1and2...GenericLetter92-0t,Revision1,ReactorVesseLStructuraLintegrity.""InfarnatfonregardfngWSEandeethodalogyofdetersinatfcnfortheLOSEfarthemfdsarefrytheXavier29,1993LetterfrcaE.E.Fit~tricktoT.E.Hurley,DonaldC.CookNuclear'PlantUnits1and2...ResponsetoRequestforAhfftfcnalfnfomatfanforGcnerfcLetter92.01,Revisicn1.5O8~~used'heLJJSEvaluesfarsidst-442,2-442and3442representtheNRCstaffcalculatedaverageofD.C.CaakandSfstarPLantdata<NcGufre,Unit1andDiabloCanyon,Unit2)forveLdufreheatscontainingheatnas.13253andf20'.TheNSEfaruelds9-44ZfsfreeMCAP.12519,"AnalysisoftheNafneYankeeReactorVesselSecondMattCapsulelocatedat253',"Narch1991.TheQJSEforzelda0-442fafreeCAP.10756,theReportforSurvefLlanceCapauf~UfreeNcafreUnitt.

~~III'CI~ItI~aI'tt:..ISII~a'L;~~S'L~RMR55~RR~'I~~~III r.".'J~e-IIPt4'