ML17228B499

Nonproprietary Version of Application of Reactor Vessel Surveillance Data for Embrittlement Mgt.

ML17228B499
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Site:	Saint Lucie
Issue date:	07/31/1993
From:	ABB COMBUSTION ENGINEERING NUCLEAR FUEL (FORMERLY, ASEA BROWN BOVERI, INC.
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CEN-405-NP, NUDOCS 9605210540
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L-96-112Enclosure2COMBUSTlONENGINEERlNGOWNERSGROUPCEN-405-NPAPPLICATIONOFREACTORVESSELSURVEILLANCEDATAFOREMBRITTLEMENTlVRMAGEMENTPreparedfortheC-EOWNERSGROUPJuly1993ABBCombustionEngineeringNuclearPower96052105409605i4PDRADQCK05000335PPDRIQdaI555P'L115NASEABROWNBOVERI WINDSOR,CONNECTICUTTABLEFET~ecinNo.~PeSUMMARYINTRODUCTIONBACKGROUNDIV.RATIONALE12'I.INTEGRATEDSURVEILLANCEAPPROACHMARGINREDUCTIONAPPROACH2029VII.CONCLUSIONS37VIII.REFERENCES39APPENDIXASTATISTICALANALYSIS,PLATEDATABASEANDRESULTSA-1APPENDIXBSTATISTICALANALYSIS,WELDDATABASEANDRESULTSB-1APPENDIXCEFFECTOFWELDFLUXLOTONWELDCHEMICALCONTENTC-1 LITFFI+i~mrT~ilDecisionTreeforSelectionofIntegratedSurveillanceApproach(ISA)orMarginReductionApproach(MRA)PredictedversusMeasuredWeldRTNO~ShiftResults16TrendCurveforA533BReferenceMaterial24MarginReductionApproach36ITFTABLSummaryofBasicStatisticsforCharpyShiftsDifferenceSampleSets19 i.MMARYThesurveillanceprogramforCombustionEngineering(C-E)designedreactorvesselsprovidesforthemonitoringofirradiationdamageinaccordancewith10CFR50,AppendixH."'anyofthoseprograms,however,donotincludethecontrollingvesselmaterialaspresentlydefinedusingRegulatoryGuide1.99,Revision02.+OneconsequenceisthatdatafromanapprovedAppendixHprogramcannotbeusedforevaluationofvesselintegrityissues.Morespecifically,directapplicationofRegulatoryGuide1.99,Position2.1torefineembrittlementpredictionsisnotavailableformanyvessels.ThisreportpresentstwoapproachesforC-EownerstoapplyRegulatoryPosition2.1inthespecificcasewhereasubjectplant'ssurveillancedataarecredibleinallrespectsexceptthatthecontrollingmaterialinthevesselgsnotoneofthesurveillanceprogrammaterials.Ifthecontrollingmaterialofonereactorvesselislocatedinthesurveillanceprogramofanothervessel,theIntegratedSurveillanceApproach(ISA)maybeapplied.Whenthecontrollingmaterialofavesselcannotbetracedtoanyothervessel'ssurveillanceprogram,theIntegratedSurveillanceApproachcannotbeusedandtheMarginReductionApproach(MRA)isapplicable.Figure1givesadecisiontreedefiningunderwhatcircumstancestheISAorMRAistobeused.IntheIntegratedSurveillanceApproach,controllingmaterialdataforthesubjectvesselisavailablefromanotherC-Efabricatedvessel(the"host"vessel)surveillanceprogram(e.g.,fromaWestinghousevessel).['Oncetheprecedinghavebeenestablished,thechemistryfactorandmarginaredeterminedforthesubjectvesselfollowingRegulatoryPosition2.1.IntheMarginReductionApproach,plant-specificsurveillancedataareusedtoreducethemargintoheaddedtothepredictedshift.P Rationaleisprovidedtosupportuseofthetwoapproaches.[

Figure'IDecisionTreeforSelect.ionofIntegratedSurvetIIanceApproach(ISA)orMarginReduct.ionApproach(MBA)LimitingMateriaIinSurveiIIanceCapsuIeYESFollowRegulatoryPoslt.lon2.1ApproachLimit.ingMat.erialinSist.erVesselSurveillanceProgramYESFoIlowISAperCEN-405P,SectionVNOFollowMRAperCEN-405P,SectionVI Thereactorpressurevesselisdesignedsuchthatitsfracturetoughnesswillbesufficienttoprovideadequatemarginsofsafetyagainstbrittlefractureduringitsservicelife.Thus,theoriginalconstructionemployedthicksectionlowalloysteelbaseandweldmaterialswhichwereinherentlytough,ascharacterizedbytheinitialreferencetemperature,RT>>Y.Particularattentionwasgiventothereactorvesselbeltline,theregionofthereactorvesselthatsurroundstheeffectiveheightoftheactivecore.Thisregionisexposedtoarelativelyhighlevelofneutronirradiationwhich,overtime,willreducethetoughnessof(i.e.,embrittle)thebaseandweldmaterials.Eachoperatingplantisrequiredtohaveareactorvesselsurveillanceprogramwhichmonitorsthoseirradiationinducedchangesinthetoughnesspropertiesofthebeltlinematerials.Neutronirradiationembrittlementofthereactorvesselbeltlineisaddressedforbothnormaloperationandfordesignbaseaccidents.Heat-upandcool-downlimitsonpressureandtemperatureareadjustedtoaccountforthepredictedirradiationinducedelevationofRT~Y.Accidentanalysesascertainthatvesselintegritywillbemaintainedintheeventofapostulatedtransient,suchaspressurizedthermalshock<'",despitepredictedembrittlementofthevessel.Ineithercase,predictionsofirradiationembrittlementarebasedonRegulatoryGuide1.99<".Insituationswhere"credible"surveillanceprogramresultsareavailable,thosepredictionsforestablishingoperatinglimitscanbeadjustedbasedonthesurveillancedata.Thisreportaddressesthespecificcasewhereaplant'ssurveillancedataarecredibleinallrespectsexceptthatthecontrollingmaterialinthevesselisnotoneofthesurveillanceprogrammaterials.Twoprescriptiveapproachesaredevelopedinordertomaximizethevaluefromplantspecificsurveillancemeasurements.IntheIntegratedSurveillanceApproach,thechemistryfactorandmarginisadjustedusingsurveillancedatafromanotherCombustionEngineering(CE)fabricatedreactorvesselofCEorWestinghousedesign.IntheMarginReductionApproach,plant-specificsurveillancedataareusedtoreducethemargintobeaddedtothepredictedshift,RationaleisprovidedtosupportuseofRegulatory Position2.1ofRegulatoryGuide1.99"'nthesespecificcases.Supplementalcriteriaareprovidedfordemonstratingtheviabilityofeachapproach.

Surveillanceprogramsweredesignedtoprovideameansof~itinirradiationbehaviorofreactorvesselbeltlinematerials.Theconceptinthe1960'swastomeasuretheextentofembrittlementtoverifytheoriginaldesignestimates.Surveillancecapsulescontainedmonitorstomeasurepeaktemperatureandneutronflux,andtestspecimenstomeasurechangesinstrengthandtoughness.Thetestspecimenswerefrommaterialsselectedto~rereenthebeltlinematerials,whereselectioncriteriareflectedthethencurrentunderstandingofradiationembrittlementtrends.Presently,surveillanceprogramrequirementsaregivenby10CFR50,AppendixH+and,byreference,ASTME185-82~'.Thestatedpurposeisstilltomonitorpropertychangeswiththeadditionthattheresultantdataaretobeusedinsupportof10CFR50,AppendixGanalysis.RegulatoryGuide1.99<"providesameansforpredictingRT>>~shiftbasedonthe~~~~~chemicalcontentofthevesselmaterialandtheneutronfluence.TheGuidealsopresentsamethod,RegulatoryPosition2.1,bywhichcrediblesurveillancedatacanbeusedtorefinetheshiftpredictionandtoreducetheuncertaintyfactor(margin)whichmustbeaddedtothemeanpredictedshift.Adichotomyexistsgivensurveillanceprogramsdesignedinthe1960'sandearly1970'sandthecurrentRegulatoryGuide1.99"'.ThemeansbywhichsurveillancematerialswereselectedforencapsulationdifferssubstantiallyfromthemethodcurrentlyprescribedintheGuide.Forexample,forthePalisadesreactorvessel,thebeltlineplateswerecomparedonthebasisofdropweightNDTTandtheCharpyimpacttestresults;+theplatewiththehighestNDLTandthehighesttemperatureatthe30ft-lbCharpyimpactvaluewasselectedforinclusioninthesurveillanceprogram.Theassumptionwasthatdifferencesintheinitialtoughnesswouldberetainedafterirradiationforplatespurchasedtothesamespecification.Itwasnotrecognizedatthetimethatsmalldifferencesinresidualchemistrycontentcouldresultinalargedifferenceinirradiationsensitivity(NDTTshift).IfthesameplateswereevaluatedusingthecurrentRegulatoryGuide1.99"',amorerigorousanalysiswouldbeperformedonthebasisofRTNpyandirradiationinducedchangesinthetransition temperature(shift)anduppershelfenergy.Theplateselectedonthisbasisforthesurveillanceprogramwouldverylikelybedifferentfromtheoneoriginallyselected.Therefore,thepost-irradiationsurveillanceplatedatawouldnotbecrediblebecauseitwouldnotmeetthefirstRegulatoryGuide1.99credibilitycriterion:"Materialsinthecapsulesshouldbethosejudgedmostlikelytobecontrollingwithregardtoradiationembrittlementaccordingtotherecommendationsofthisguide.""'ence,thedichotomyexists;thenon-crediblereactorvesselsurveillancedatacannotbeusedtocomputethebest-fitchemistryfactor,andanyfurtheruseofthesurveillancedatamustbejustifiedtotheNRCeventhoughthesurveillanceprogramcomplieswiththeversionofASTME185ineffectatthetimetheprogramwasdesigned.~~~~~Thissituationexistsformanyreactorvesselsbecauseofdifferencesinmethodstodefineinitialtoughnessandtopredictshift.RT~~wasusedinthesurveillancematerialselectionprocessforthosevesselsbuilttotheSummer1972AddendatotheASMEBoilerandPressureVesselCode."@Forearliervessels,NDTl'raCharpyindextemperaturewasusedtodifferentiateinitialtoughnesspropertiesofthecandidatematerials.Shiftpredictionsformaterialselectionwerebasedonrangesofcoppercontent;separatetrendcurveswereusedfor0to0.10%Cu,0.11to0.15%Cu,andgreaterthan0.15%Cu.Typically,thebeltlineplatesfromonevesselwouldallfallwithinonerangeofcoppercontentand,therefore,bepredictedtoexhibitthesameshift.Thebeltlineweldswouldhaveasimilarsituation.Incontrast,RegulatoryGuide1.99"'redictionsarebasedonexplicitvaluesofcopperandnickelcontentsuchthateachbeltlineplateandweldwouldhaveauniquepredictedshift.Giventhemajordifferencesinmethodsusedtoselectthesurveillancematerialandpresentdaycriteria"'oridentifyingthecontrollingmaterial,theprobabilityofhavingtheprecisecontrollingmaterialinthesurveillancecapsuleislow.Asaconsequence,presentruleswillseverelylimitthenumberofreactorvesselstowhichRegulatoryPosition2.1tucanbeapplied.

ReactorvesselsdesignedandbuiltbyBabcock&Wilcoxencounteredaproblemwiththesurveillanceprogramwhichpromptedtheestablishmentofanintegratedsurveillanceprogram(seeforexampleReference6).Theprobleminvolvedboththeforcedremovalofsurveillancecapsulesfromseveralreactorvesselsandtheneedforcontinuedsurveillanceofthebeltlinematerialsfromthosevessels.TheB&WsituationwastheimpetusforSectionII.Cof10CFR50,AppendixH@whichdetailedrequirementsandacceptancecriteriaforestablishinganintegratedsurveillanceprogram.Thebasicapproachentailsirradiationofrepresentativematerialinahostreactorforusebyotherreactorshavingsimilardesignandoperatingfeatures.Presumably,thatdatacouldalsobeusedinaccordancewithRegulatoryPosition2.1<uforAppendixG"'nalyses.IntheB&Wsituation,numerousvesselswerefabricatedusingsimilarmaterialsandprocesses,includingthosevesselsmadeforuseinWestinghousedesignedPWRs.SimilartoB&W,CombustionEngineeringalsofabricatedvesselsforWestinghouse.Therefore,surveillancematerialsfromWestinghousedesignedvesselsrepresentapotentialsourceofdataonspecificheatsandtypesofvesselbeltlinematerials.Establishmentofanintegratedsurveillanceprogrambetweentwovesselssuppliedbythesamefabricatorcould,innumerouscases,providesurveillancedataonthecontrollingvesselmaterialforoneorbothofthosevessels.IncontrasttotheB&Wsituation,wheresomevesselshadtohavethesurveillancecapsulesremoved,alloftheC-EdesignedPWRsstillhavesurveillancecapsules.Therefore,measurementsofneutronflux,irradiationtemperature,andsurveillancematerialirradiationsensitivitycanbeobtainedforeachC-Evessel.ThisprovidesforthemonitoringrequiredbyAppendixH,"'ndimplementationofanintegratedsurveillanceprogramcouldprovidethedataonthecontrollingmaterialasinputforanalysesrequiredbyAppendixG"'nd10CFR50.61.""

TheobjectiveofthisreportistoestablishtwoapproachesforimplementingRegulatoryPosition2.1"'orC-EdesignedPWRsforwhichthesurveillanceprogramiscredibleinallrespectsexceptthatthecontrollingmaterialinthevesselisnotinthesurveillanceprogram.IntheIntegratedSurveillanceApproach,dataforthecontrollingmaterialisobtainedfromanotherreactorvesselsurveillanceprogram.IntheMarginReductionApproach,theplant-specificdataareusedwhendataonthecontrollingmaterialareunavailable.BothapproachesareintendedtoaddresstheRegulatoryPosition2.1"'aseinwhich"...surveillancedataarecredibleinallrespectsexceptthatthe(surveillance)materialdoesnotrepresentthecriticalmaterialinthevessel..."Theprimarypurposeistorealizeasfullyasreasonablethebenefitsfromthesurveillanceprogramoncecertaincriteriahavebeensatisfied.ThosecriteriaincludethesurveillancedatacredibilityfactorsgiveninRegulatoryGuide1.99<"and,whereapplicable,thecriteriagivenin10CFR50,AppendixH+foranintegratedsurveillanceprogram.TheaddedcertaintyobtainedthroughsurveillancecapsulemeasurementsjustifiesrealizationofthebenefitsfromapplicationofRegulatoryPosition10)ThepurposeofthissectionistodescribetherationaleusedinestablishingtheIntegratedSurveillanceandMarginReductionApproaches.'.(NotethatthesecondandthirdrationaleelementsaredirectedprimarilyattheIntegratedSurveillanceApproach.)Thethreeelementsaredetailedbelow.

PREDICTEDVERSUSMEASUREDWELDRTNDTSHIFTRESULTS4003503002502000z1501000SURVEILLANCEDATAPEXERIMENTALDATA(WELD-1,LCP)orr~rrQPOSITIOH2.1.RG'I.99REY.2CURVEFITTOSURVEILLANCEWELDDATAWITHlrr=28FBOUNDS500.10.20.40.60.81.02.04.06.08.010.0~FLUENCE(E>1MeV).10n/cm Table1 V.IERATEDREILLAEAPPRAHThepurposeofthissectionistoestablishthecriteriawhichneedtobeaddressedandtheproceduretobefollowedinordertoutilizesurveillancedatafromanotherreactorvesselinsupportofaRegulatoryPosition2.1<"analysis.TheapproachcombinesthecredibilitycriteriaofRegulatoryGuide1.99tuwiththeconceptofintegratedsurveillanceprogramsdefinedin10CFR50,AppendixH.o'riortoapplyingRegulatoryPosition2.1perthisapproachasshowninSectionV.E.,thefollowingmustbeestablished:traceabilityofthecontrollingmaterial(SectionV.A.),thecredibilityofthesubjectvessel(SectionV.B.)andhostvesselsurveillancedata(SectionV.C.),andthesimilarityoftheirradiationenvironmentofbothvessels(SectionV.D.).-A'<<h'dihhprogramisequivalenttothecontrollingmaterialinthesubjectvessel.

'ecVelrvillnDrediili-Thesurveillancedatafromthesubjectreactorvesselmustbecredibleinallrespectsexceptthatthesurveillancematerialdoesnotrepresentthecriticalmaterialinthevessel.ThisisestablishedbysatisfyingthefollowingfivecriteriawhicharetakenfromReference1withmodificationstoitems1and5:1.Materialsinthecapsuleshallberepresentativeofthe,,reactorvesselbeltlinematerials,includingbothbasemetalandweldmetal.[

2.Determinationofthe30ft-lbindextemperatureandtheupper-shelfenergyshallbedoneunambiguouslyforboththeirradiatedandunirradiatedCharpydata'.Twoormoresetsofpost-irradiationsurveillancedataforbothbaseandweldmetalshallbeavailablefromthesubjectreactorvessel,andaRegulatoryPosition2.1analysisshallbeperformed.Themeasurementsshallbewithin+lo~ofthemeancurveoftheactualsurveillancedata,wherea~is17'Fforbasemetaland28'Fforweldmetal."'fthefluencerangeistwoordersofmagnitudeorgreater,themeasurementsmustbewithin+2r~.<'>4.TheirradiationtemperatureoftheCharpyspecimensshallbewithinJ25'Fofthevesselwalltemperatureatthecladding/basemetalsurface."TheCharpyspecimentemperatureshallbeestimatedbasedonevaluationofthetemperaturemonitorsincludedinthesurveillancecapsulesorfromheattransfercalculations.Thevesselwalltemperatureshallbebasedoncoldlegorvesselwallmeasurements.5.OneofthesurveillancecapsulesusedintheevaluationshouldincludeCharpyspecimensfromastandardreferencematerial.(CEOGvesselsurveillanceprogramsuseHSST01forreferencematerial.)Themeasuredshiftforthestandardreferencematerialshallfallwithinthescatterband(J2ogofthedatabaseforthatmaterialasgiveninFigure3.""C.HstReacrurveillanceDataribili-Theprincipalinterestinthehostreactordataistheonesurveillanceplateorweldrepresentingthesubjectreactor'scontrollingmaterial.ThefollowingcriteriaarebasedonthefivecriteriafromReference1,withmodificationstoitems1,4and5.Eachofthefollowingcriteriaaretobesatisfiedtoestablishthecredibilityofdataforthatonematerial:

1.ThetraceabilitybetweenthecontrollingmaterialfromthesubjectreactorandsurveillancematerialfromthehostreactoristohavebeenestablishedasdetailedinV.A.2.Determinationofthe30ft-lbindextemperatureandtheupper-shelfenergyshallbedoneunambiguouslyforboththeirradiatedandunirradiatedCharpydata.<u3.Twoormoresetsofpost-irradiationsurveillancedataforthecontrollingmaterialshallbeavailablefromthehostreactorvessel,andaRegulatoryPosition2.1analysisshallbeperformed.Themeasurementsshallbewithin+la~ofthemeancurveoftheactualsurveillancedata,whereo~is17'Fforbasemetaland28'Fforweldmetal."'fthefluencerangeistwoordersofmagnitudeorgreater,themeasurementsmustbewithin+2a~.<'>4,TheirradiationtemperatureoftheCharpyspecimensshallbewithinJ25'Fofthevesselwalltemperatureatthecladding/basemetalsurface."'heCharpyspecimentemperatureshallbeestimatedbasedonevaluationofthe.temperaturemonitorsincludedinthesurveillancecapsulesifavailable.Thevesselwalltemperatureshallbebasedoncoldlegorvesselwallmeasurements.5.Standardreferencematerial(SRM)isnotavailableinsomehostreactorvesselsurveillanceprograms.rHowever,ifSRMisavailableforoneormorehostreactorcapsules,themeasuredshiftfortheSRMshallfallwithinthescatterband(J2rgofthedatabaseforthatmaterialasgiveninFigure3.""

i25200IO7i50mta.aaouO100illI-CIlIcc50vv/'e/vv%SurvoillancoCapoulooHSSTOZ0SurvolllancoCapauloaHSST01h8SRXrradiationa(HSSTO?)VORR-PSFXrradlatlone(HSST03)i0075o50250.000.50i.00i.50Z.OO2.50"'3.003.504.004.505.00<Ei9Fluanco(6>i.0Hov)FIGURE3TRENDCURVEFORA533BREFERENCEMATERIALEmbrittlementoftheA533BreferencematerialrelativetothedraftReg.Guide1.99,Revision2.ThevaluesforHSST01andHSST03plates-areadjustedrelativetoHSST02platetoaccountfordifferencesinchemistry.Theupperandlowercurvesarethe34oFuncertaintybounds(20)specifiedbyReg.Guide1.99.(Source:Reference15)

D.IditinEnvirnmenmrin-AscertainthattheirradiationenvironmentforthehostreactorsurveillancecapsuleiscomparabletothatforthesubjectreactorsurveillancecapsuleusingthefollowingfactorsandprovideaqualitativerankingofthetwocapsulesintermsofthesignificanceofanydifferencesonRTNprshift.1.ReactorCoolantInletTemperature2.NeutronFlux(E.liinfReulPiin21-Oncethefourprecedingitemshavebeensatisfactorilyaddressed,thehostreactorsurveillancedataforthecontrollingmaterialmaybeusedtodeterminetheadjustedreferencetemperatureforthatmaterialinaccordancewithRegulatoryPosition2.1"'sfollows:

Theoverallequivalenceofthesubjectreactorvessel'scontrollingmaterialandthehostreactorvessel'ssurveillancematerialwasestablishedinSectionV.A.Ifthereportedcopperandnickelcontentofbothmaterialsisidentical,thenproceedtostep2.If,however,theyarenotidentical,thenthemeasuredvaluesofshift,ART>>T,shallbeadjustedbymultiplyingthembytheratioofthechemistryfactorforthevesselmaterialtothatofthesurveillancematerialinaccordancewithRegulatoryPosition2.1.2.FitthesurveillancedatatoobtaintherelationshipofART>>Ttofluenceusingthefollowingequation:Azr=(t"z)s<'-'""g'~NDTwhere:CF=chemistryfactorf=neutronfluence(10"n/cm',E)1Mev)Todoso,calculatethechemistryfactor,CF,forthebestfltbymultiplyingeachART>>T(ortheadjustedvaluesfromstep1)byitscorrespondingfluencefactor,summingtheproducts,anddividingbythesumofthesquaresofthefluencefactors.TheresultantvalueofCFisthentobeenteredintoequation1forcalculatingART>>T.Note:Ifthehostreactorsurveillancedataarelessthanpredicted,butthesubjectreactorsurveillancedataaregreaterthanpredicted,thenapplicationoftheCFderivedfromthehostreactorcouldbenon-conservativeforthesubjectreactor.Inthissituation,thehostreactorcalculatedchemistryfactorcanbeadjustedasfollows;CF(H)xQFF'~=AdjustedCFCF(S,P) where:CF(H)isthecalculatedCFforthehostreactorfromstep2CF(S,C)isthecalculatedCFforthecorrespondingplateorweldforthesubjectreactorfollowingstep2CF(S,P)isthepredictedCFforthesamesubjectreactormaterialbasedonTable1or2ofReference1Thelargerofthetwovalues,AdjustedCForCF(H)shouldthenbeenteredintoequation1.3.Calculatemarginasfollows:Margin=2or+a~22(2)where:0;=standarddeviationfortheinitialRT>>T0~=standarddeviationford,RTNDT)gncaseswhereagenericvalueisassumedforSA533BClass1orSA302B(Modified)plates,0;istobedeterminedbasedonthevarianceofthedatausedtoderivethegenericvalue.)

Thestandarddeviationforshift,0~,canbereducedto8.5'Fforbasemetaland14'FforweldsifthesurveillancedatacredibilityhasbeenestablishedinaccordancewithsectionsV.BandV.CperRegulatoryPosition2.1"'ndtheirradiationenvironmentshavebeenestablishedtobecomparableinaccordancewithSectionV.D.4.CalculateadjustedRT~(ART)asfollows:ART=RT~+hRT~~+Marginwhere:RTNDvinitialRTN~,measuredorgenericvalueb,RTND~=shift,usingrevisedchemistryfactorinequation1Margin=valueusingequation2includingvaluesof0;and0~fromstep35.DocumentresultsoftheevaluationfollowingSectionV.AthroughV.E,includingassumptionsemployedandconclusionsreached.

VI.MARIREDTINAPPRAHTheprevioussectionaddressedthespecialcaseinwhichanintegratedsurveillanceprogramapproachcouldbeusedtoaugmentplant-specificsurveillancedata.Thepurposeofthissectionistoaddressthecaseinwhichsurveillancedataonthecontrollingmaterialisnotavailablefromeithertheplant-specificprogramoranotherreactorvessel,butthesurveillancedataarecredibleinallotherrespects.AnapproachisgivenfordetermininghowmuchthestandarddeviationfordRTND~,0~,canbereducedbasedonthedegreeofcredibilityofthesurveillancecapsulemeasurementsor,asphrasedinRegulatoryPosition2.1<","dependingonwherethemeasuredvaluesfallrelativetothemeancalculatedforthesurveillancematerials".ThefollowingprocedurepresentsarecommendedapproachforsatisfyingRegulatoryPosition2.1"'nordertoreducethevalueof0~.Theprocedurewhichfollowsaddressestwoissues,representativematerialsandpredictabilityofthesurveillancemeasurements,asthebasisforreducingthevalueof0~.A,rnivM'EachsurveillanceprogramforaC-EdesignedreactorvesselincludesencapsulatedCharpyspecimensfromaplate,weld,heat-affected-zone,andstandardreferencematerial(SRM).InaccordancewiththeeditionofASTME185ineffectatthetime,thesurveillancematerials(exclusiveofSRM)wereselectedtorepresentthereactorvesselbeltline.Thesurveillanceplatewasselectedfromoneofthesix(typical)beitiineplates.[

ThesurveillanceweldwasfabricatedusingportionsoftwobeltlineplatesfollowingthesameprocedureandweldconsumablesasoneofthebeltlineweldsInsummary911-RglGdjd199"'911*1jdgjggcredibilityofsurveillancedata.ThefourRegulatoryGuidecriteriadealingwithI)scatteroftheCharpydata,2)scatteraboutthedRTN~versusneutronfluencebestfitcurve,3)capsuleirradiationtemperature,and4)SRMtestresultsshallbeevaluated.Oncethosecriteriaaresatisfieddatapredictabilityneedstobeevaluatedtoprovidethebasisforreducingthevalueof0~.

C.AlicainfRelPiin11withMarinReduction-Oncethetwoprecedingitemshavebeensatisfactorilyaddressed,theknowninformationonthecontrollingmaterialmaybeusedtodeterminetheadjustedreferencetemperatureforthatmaterialinaccordancewithRegulatoryPosition1.1"'sfollows:l.Obtainthevalueofd,RT>>~basedonthechemistryfactorofthecontrollingmaterialandthefluenceusingthefollowingequation:(peP0.28-0.10logj)(1) where:CF=chemistryfactorf=neutronfluence(10"n/cm',E)1Mev)Todoso,calculatethechemistryfactor,CF,forthecontrollingmaterialusingtheknownchemicalcompositionasprescribedinRegulatoryPosition1.1ofReference1.Iftheexactchemicalcompositionisnotknown,usetheguidelinesofReference1todeterminetheappropriatechemistryfactor.2.Calculatemarginasfollows:Margin=2ol+(RFa~)(2)where:0;=standarddeviationfortheinitialRTiT0~=standarddeviationforhRTNDTRF=reductionfactorfromSectionVI.Bandasdescribedbelow(IncaseswhereagenericvalueisassumedforSA533BClass1orSA302B(Modified)plates,0;istobedeterminedbasedonthevarianceofthedatausedtoderivethegenericvalue.)

ThestandarddeviationindRT>>Y,0~,asdefinedinRegulatoryGuide1.99is:0~=28'Fforweldsando~=17'Fforbasemetal.TheMarginReductionApproachmaythenbeappliedtothecontrollingmaterialbasedontheresultsoftestingoftheavailablecrediblesurveillancedatatoreducetherequiredvalueof0~asfollows:where:P=predictedshiftbasedonEquation2ofRegulatoryGuide1.99+M=measuredshiftforbasemetal(longitudinalortransverseorientation)andweld0~=standarddeviationforART>>Ywhichis17'Fforplatesand28'Fforwelds<n3.CalculateadjustedRT>>Y(ART)asfollows:ART=RTNDz+B,RT>Dr+Marginwhere:RTNDART>>YMargininitialRT>>Y,measuredorgenericvalueshift,usingequation1valueusingequation2includingvaluesof0;and0~fromstep2 Th*Ifhp&igdibd&.TMshouldincludedemonstrationthatthesurveillancematerialsarerepresentativeofthereactorvesselbeltlinematerialsasdescribedinSectionVI.A.ThesurveillancedatacredibilityshallbeestablishedusingdatasetsfromtwoormoresurveillancecapsulesandthefourRegulatoryGuide1.99criteriaidentifiedinVI.B.Finally,thesurveillancematerialpredictabilityandtheresultant0~reductionfactorshallbeestablishedfollowingtheproceduregiveninSectionVI.C.

rrcuRE4MARnxREnVCYrOxA.ppROA.eH NLIAdvancementsintechnologyforpredictingtheextentofneutronirradiationembrittlementinpressurevesselsteelshavecausedsignificantchangesinthedefinitionofthe"controlling"vesselbeltlinematerial.Oneconsequenceisthesurveillancecapsulesdonotcontainthatcontrollingmaterial.RegulatoryPosition2.1ofRegulatoryGuide1.99"'ermitstheuseofdatafromthereactorvesselsurveillanceprogramtorefineshiftpredictionsbutonlyforthoseprogramswhichincludethecontrollingvesselmaterial.Thisreportprovidesthejustificationforemployingsurveillancedatainsupportofvesselembrittlementanalyseswhenthesurveillancedataarecredibleinallrespectsexceptthecontrollingmaterialisnotoneofthesurveillanceprogrammaterials.ApproachesareprovidedforIntegratedSurveillanceandMarginReductiontomaximizethevaluegainedfromplant-specificsurveillancemeasurements.IntheIntegratedSurveillanceApproach,dataforthecontrollingmaterialfromahostreactor~~~vesselsurveillanceprogramisusedinconjunctionwithplant-specificdatatoadjustthechemistryfactorandreducetherequiredstandarddeviationforshift.ThisdatasharingbetweenWestinghouseandCombustionEngineeringreactorvesselsurveillanceprogramsisjustifiedbasedonthefollowingrationale:

~~~TheIntegratedSurveillanceApproachidentifiescriteriatobeaddressedandaproceduretofollowinordertoutilizethehostreactorsurveillancedatainsupportofaRegulatoryPosition2.1<'>analysisforaC-Evessel.IntheMarginReductionApproach,theplant-specificsurveillancedataareusedtoreducethemarginforpredictedshiftofthecontrollingmaterialbasedonthepredictabilityofthesurveillancemeasurements.ThetwoapproachespresentedinthisreportareapplicabletosurveillanceprogramsforC-Edesignedreactorvessels,TheiruseisnotintendedforothervesseldesignsandsurveillanceprogramsbecausetheapproacheswerebasedinpartonpracticesanddesigncharacteristicsuniquetoC-E.~~

VILl.USNRCRegulatoryGuide1.99,Revision2,"RadiationEmbrittlementofReactorVesselMaterials,"May1988.2.AmericanSocietyforTestingandMaterials,"StandardPracticeforConductingSurveillanceTestsforLight-WaterCooledNuclearPowerReactorVessels"ASTME185-82,July1982.3.10CFRPart50,AppendixH,"ReactorVesselMaterialsSurveillanceProgramRequirements,"FederalRegister,Vol.48,No.104,May27,1983.4,10CFRPart50,AppendixG,"FractureToughnessRequirements,"Ibid.5."SummaryReportonManufactureofTestSpecimensandAssemblyofCapsulesfor~~~~IrradiationSurveillanceofPalisadesReactorVesselMaterials,"CombustionEngineeringReportP-NLM-019,April1971.6."Babcock&WilcoxOwnersGroupProgramforEvaluationofReactorVesselProperties,"BAW-1474,Rev.4,December1986.7.AmericanSocietyforTestingandMaterials,"StandardPracticeforCharacterizingNeutronExposuresinFerriticSteelsinTermsofDisplacementsperAtom(DPA),"ASTME693-79,August1979.8.W.N.McElroy,"LWRPressureVesselSurveillanceDosimetryImprovementProgram:LWRPowerReactorSurveillancePhysic-DosimetryDataBaseCompendium,"NUREG/CR-3319,preparedbyHanfordEngineeringDevelopmentLaboratory,HEDL-TME85-3,August1985.

9.R.K.Nanstad,et.al,"Effectsof50'CSurveillanceandTestReactorIrradiationsonFerriticPressureVesselSteelEmbrittlement,"presentedatthe14thInternationalASTMSymposiumontheEffectsofRadiationonMaterials,Andover,Massachusetts,June1988.10."EvaluationoftheFirstMaineYankeeAcceleratedSurveillanceCapsule,"EffectsTechnology,Inc.,ReportCR75-317,August15,1975.11."MaineYankeeNuclearPlantReactorPressureVesselSurveillanceProgram-Capsule263,"BattelleColumbusLaboratoriesReportBCL-385-21,December12,1980.12."AnalysisoftheMaineYankeeReactorVesselSecondAcceleratedSurveillanceCapsule,"WestinghouseReportWCAP-9875,March1981.J.R.Hawthorne,J.J.Koziol,andS.T.Byrne,"EvaluationofCommercialProductionA533-BSteelPlatesandWeldDepositswithExtra-LowCopperContentforRadiationResistance,"NRLReport8136,October21,1977.14.J.R.Hawthorne,"NotchDuctilityDegradationofLowAlloySteelswithLow-to-IntermediateNeutronFluenceExposures,"NRLReport8357(NUREG/CR-1053),January14,1980.15.F.W.Stallman,"AnalysisoftheSA302BandSA533BStandardReferenceMaterialsinSurveillanceCapsulesofCommercialPowerReactors,"NUREG/CR-4947,preparedbyOakRidgeNationalLaboratory,ORNL/TM-10459,January1988.16.AmericanSocietyofMechanicalEngineering,SectionIII,"NuclearPowerPlantComponents,"ofMEBilerndPrerV1e,NewYork.

"EvaluationofPressurizedThermalShockEffectsDuetoSmallBreakLOCA'swithLossofFeedwaterfortheCombustionEngineeringNSSS,"CombustionEngineeringReportCEN-189,December1981.18.F.W.Stallman,et.al.,"PR-EDB:PowerReactorEmbrittlementDataBase,Version1,"NUREG/CR-4816,preparedbyOakRidgeNationalLaboratory,ORNL/TM-10328,June1990.19.10CFRPart50,Section50.61,"FractureToughnessRequirementsforProtectionAgainstPressurizedThermalShockEvents,"FederalRegister,Vol.56,No.94,May15,1991.

0 APPENDIXASTATISTICALANALYSISPLATEDATABASEANDRESULTS A.1DATABASEAPPENDIXAThereactorvesselsurveillanceplatedatabaseusedinthestatisticalanalysisislistedinTablesA-1andA-2forCombustionEngineeringandWestinghouseNSSSs,respectively.-A Thelattertwotests(candd)wereperformedasanovercheckonthemoretraditionalFandttests.-A TablREACTORVESSELPLATESURVEILLANCEDATACOMBUSTIONENGINEERINGNSSS

TableA-1(contin Table-2REACTORVESSELPLATESURVEILLANCEDATAWESTINGHOUSENSSS TableA-tinued) 0 TableA-tinued)I00I TableA-ntinued) tinued)

TableA-3A302BPLATENICKELCONTENT~VeelYankeeRoweN/ABigRockH.B.RobinsonMri1IifiinUpperShellPlateTestMaterialYA9HSSTPlateSurveillancePlateW-9807-3W-9807-5W-9807-9W-10201-1W-10201-2W-10201-3W-10201-4W-10201-5W-10201-6iklnno0.210.190.180.180.100.100.150.110.2S0.080.090.120.09MeanValue:0.14%NiRange:0.08to0.25%NiStandardDeviation:0.055%Ni FIGUREA-I(PRED-ACT)CVTSHIFT:vaCUCONTENTC-E8Meat,inghouaePlacteaCuContent.(%)-A-12-oC-E+Meatinghnuse 0

HiGURKA-2(PRED-ACT)CVTSHIFTusNXCONTENTC-EaNest.3.nghouseelatesNiCuntent'.(%)C-E+Mestinghnuse

'lGUREA-3(PRED-ACT)CVTSHIFTvaFASTFLUENCEC-E8Mant'.inghouaaPlatenFaatFluence(x18".18n/cm"2)-A-14-oCF+Meetinghouae FIGUREA-4(PRED-ACT)CVTSHIFTvsNEUTRONFLUXC-E8Masts.nghuusaPlatesFlux(xi.8"18/cm"2sec)oC-E+Mastinghouse FIGUREA-5(PRED-ACT)CVTSHIFTFORC-EPLATESFv.aquanautHiat'.ngramGVTShif'tDif'f'erenae(Deg.F)-A FIGUREA-6(PRED-AGT)GVTSHXFTFORMEST.PLATESFrequenc:gHint'ogramCVTShit'0Di,f'f'arant"a(Dag.F)

FIGUREA-7(PRED-ACT)CVTSHIFTFORALLPLATESFrequenc:gHi@tagl"amCVTShif'tDif'f'erent"e(Deg.F)

FIGUREA-8(PRED-ACT)CVTSHIFTFOPPLATESC-E8Meat.NormalPrub.DeneitgFane<xe.eel>CVTShit'tDif'f'aranc:mCDag.F)C-EMeatinghouae FIGUREA-9(PRED-ACT)CVTSHXFTFORPLATESNarmalProbabi1ityDenaityFunctinn(xe.eel)CVTShif'tDif'f'erence(Deg.F)-A APPENDIXBSTATISTICALANALYSISWELDDATABASEANDRESULTS B.1DATABASEAPPENDIXBThereactorvesselsurveillancewelddatabaseusedinthestatisticalanalysisislistedinTablesB-1andB-2forCombustionEngineeringandWestinghouseNSSSs,respectively.-B Thelattertwotests(candd)wereperformedasanovercheckonthemoretraditionalFandttests.-B REACTORVESSELWELDSURVEILLANCEDATACOMBUSTIONENGINEERINGNSSS TableB-1(continu TableB-2REACTORVESSELSURVEILLANCEDATAWESTINGHOUSENSSS TableB-2(continuItxfOOI TableB-2(continu FIGUREB-1(PRED-ACT)CVTSHIFTvsCUCONTENTC-E8WestinghouseWeldsCuContent(%)-B-10-0C-E+Westinghouse FIGUREB-2'C(PRED-ACT)CVTSHXFTvsNXCONTENTC-E8Mestinghouse4le1dsNiContent.(%)-B-11-C-E+Meat.inghuuae FIGUREB-3(PRED-ACT)CVTSHXFTvsFASTFLUENCEC-E8Mest.inghuuseMe1dsFast'.Fluenc:e(xi,8"18n/t"m2)-B-12-oC-E+Mestinghouse FIGUREB-4(PRED-ACT)CUTSHXFTvaNEUTRONFLUXC-E8MeetinghouseMeldsFlux(xi8"i,8n/am"2sec)-B-13-0QP+Meetinghouse FIGUREB-5(PRED-ACT)CUTSHIFTFORC-EMELDSFrequencyHistogram.CUTShit't'.Dif'f'erence(Deg.F3-B FIGUREB-6(PRED-ACT)CVTSHIFTFORMEST.MELDSFrequencLIHj.at'.ogramCVTShif't.Dif'terence(Deg.F)-B FIGUREB-7(PRED-ACT)CUTSHIFTFORALLMELDSFraquanc:LIHiatngramCUTShit't'.Dif'f'erenae(Deg.F)

IFIGUREB-8(PRED-ACT)SHXFTFORWELDSC-E8Wast.NurmalProb.Dansi<gFncs~Q0L50II~lg0Q.CVTShif'tDif'f'erence(Deg.F)-B-17--C-EWestinghouse FIGUREB-9(PRED-ACTiSHXFTFOR4lELDSNormalPI"ah@bi1itgDensityFunction<xe.eel>CVTShit'tDif'f'erence(Deg.F)-B APPENDIXCEFFECTOFWELDFLUXLOTONWELDCHEMICALCONTENT APPENDIXCC.IINTRODUCTION]C.2WELDFLUXTYPE-C C.3WELDFLUXLOT-C TABLEC-1ExpectedEffectofFluxTypeontheAs-DepositedWeldPropertiesUsingtheSameWeldWire TABLEC-2As-DepositedWeldChemistriesasaFunctionofFluxTyye-C As-DepositedWeldChemistriesasaFunctionofFluxLot(WeldWireHeat¹4P7869)-C llte0e-