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-96-112Enclosure 2COMBUSTlON ENGINEERlNG OWNERSGROUPCEN-405-NP APPLICATION OFREACTORVESSELSURVEILLANCE DATAFOREMBRITTLEMENT lVRMAGEMENT PreparedfortheC-EOWNERSGROUPJuly1993ABBCombustion Engineering NuclearPower9605210540 9605i4PDRADQCK05000335PPDRIQdaI555P'L115NASEABROWNBOVERI WINDSOR,CONNECTICUT TABLEFET~ecinNo.~PeSUMMARYINTRODUCTION BACKGROUND IV.RATIONALE 12'I.INTEGRATED SURVEILLANCE APPROACHMARGINREDUCTION APPROACH2029VII.CONCLUSIONS 37VIII.REFERENCES 39APPENDIXASTATISTICAL

ANALYSIS, PLATEDATABASEANDRESULTSA-1APPENDIXBSTATISTICAL

ANALYSIS, WELDDATABASEANDRESULTSB-1APPENDIXCEFFECTOFWELDFLUXLOTONWELDCHEMICALCONTENTC-1 LITFFI+i~mrT~ilDecisionTreeforSelection ofIntegrated Surveillance Approach(ISA)orMarginReduction Approach(MRA)Predicted versusMeasuredWeldRTNO~ShiftResults16TrendCurveforA533BReference Material24MarginReduction Approach36ITFTABLSummaryofBasicStatistics forCharpyShiftsDifference SampleSets19 i.MMARYThesurveillance programforCombustion Engineering (C-E)designedreactorvesselsprovidesforthemonitoring ofirradiation damageinaccordance with10CFR50,AppendixH."'anyofthoseprograms, however,donotincludethecontrolling vesselmaterialaspresently definedusingRegulatory Guide1.99,Revision02.+Oneconsequence isthatdatafromanapprovedAppendixHprogramcannotbeusedforevaluation ofvesselintegrity issues.Morespecifically, directapplication ofRegulatory Guide1.99,Position2.1torefineembrittlement predictions isnotavailable formanyvessels.Thisreportpresentstwoapproaches forC-EownerstoapplyRegulatory Position2.1inthespecificcasewhereasubjectplant'ssurveillance dataarecredibleinallrespectsexceptthatthecontrolling materialinthevesselgsnotoneofthesurveillance programmaterials.

Ifthecontrolling materialofonereactorvesselislocatedinthesurveillance programofanothervessel,theIntegrated Surveillance Approach(ISA)maybeapplied.Whenthecontrolling materialofavesselcannotbetracedtoanyothervessel'ssurveillance program,theIntegrated Surveillance ApproachcannotbeusedandtheMarginReduction Approach(MRA)isapplicable.

Figure1givesadecisiontreedefiningunderwhatcircumstances theISAorMRAistobeused.IntheIntegrated Surveillance

Approach, controlling materialdataforthesubjectvesselisavailable fromanotherC-Efabricated vessel(the"host"vessel)surveillance program(e.g.,fromaWestinghouse vessel).['

Oncethepreceding havebeenestablished, thechemistry factorandmarginaredetermined forthesubjectvesselfollowing Regulatory Position2.1.IntheMarginReduction

Approach, plant-specific surveillance dataareusedtoreducethemargintoheaddedtothepredicted shift.P Rationale isprovidedtosupportuseofthetwoapproaches.

[

Figure'IDecisionTreeforSelect.ion ofIntegratedSurvetIIanceApproach(ISA)orMarginReduct.ionApproach(MBA)LimitingMateriaIinSurveiIIanceCapsuIeYESFollowRegulatory Poslt.lon2.1ApproachLimit.ing Mat.erial inSist.erVesselSurveillance ProgramYESFoIlowISAperCEN-405P, SectionVNOFollowMRAperCEN-405P, SectionVI Thereactorpressurevesselisdesignedsuchthatitsfracturetoughness willbesufficient toprovideadequatemarginsofsafetyagainstbrittlefractureduringitsservicelife.Thus,theoriginalconstruction employedthicksectionlowalloysteelbaseandweldmaterials whichwereinherently tough,ascharacterized bytheinitialreference temperature, RT>>Y.Particular attention wasgiventothereactorvesselbeltline, theregionofthereactorvesselthatsurrounds theeffective heightoftheactivecore.Thisregionisexposedtoarelatively highlevelofneutronirradiation which,overtime,willreducethetoughness of(i.e.,embrittle) thebaseandweldmaterials.

Eachoperating plantisrequiredtohaveareactorvesselsurveillance programwhichmonitorsthoseirradiation inducedchangesinthetoughness properties ofthebeltlinematerials.

Neutronirradiation embrittlement ofthereactorvesselbeltlineisaddressed forbothnormaloperation andfordesignbaseaccidents.

Heat-upandcool-down limitsonpressureandtemperature areadjustedtoaccountforthepredicted irradiation inducedelevation ofRT~Y.Accidentanalysesascertain thatvesselintegrity willbemaintained intheeventofapostulated transient, suchaspressurized thermalshock<'",despitepredicted embrittlement ofthevessel.Ineithercase,predictions ofirradiation embrittlement arebasedonRegulatory Guide1.99<".Insituations where"credible" surveillance programresultsareavailable, thosepredictions forestablishing operating limitscanbeadjustedbasedonthesurveillance data.Thisreportaddresses thespecificcasewhereaplant'ssurveillance dataarecredibleinallrespectsexceptthatthecontrolling materialinthevesselisnotoneofthesurveillance programmaterials.

Twoprescriptive approaches aredeveloped inordertomaximizethevaluefromplantspecificsurveillance measurements.

IntheIntegrated Surveillance

Approach, thechemistry factorandmarginisadjustedusingsurveillance datafromanotherCombustion Engineering (CE)fabricated reactorvesselofCEorWestinghouse design.IntheMarginReduction

Approach, plant-specific surveillance dataareusedtoreducethemargintobeaddedtothepredicted shift,Rationale isprovidedtosupportuseofRegulatory Position2.1ofRegulatory Guide1.99"'nthesespecificcases.Supplemental criteriaareprovidedfordemonstrating theviability ofeachapproach.

Surveillance programsweredesignedtoprovideameansof~itinirradiation behaviorofreactorvesselbeltlinematerials.

Theconceptinthe1960'swastomeasuretheextentofembrittlement toverifytheoriginaldesignestimates.

Surveillance capsulescontained monitorstomeasurepeaktemperature andneutronflux,andtestspecimens tomeasurechangesinstrengthandtoughness.

Thetestspecimens werefrommaterials selectedto~rereenthebeltlinematerials, whereselection criteriareflected thethencurrentunderstanding ofradiation embrittlement trends.Presently, surveillance programrequirements aregivenby10CFR50,AppendixH+and,byreference, ASTME185-82~'.

Thestatedpurposeisstilltomonitorpropertychangeswiththeadditionthattheresultant dataaretobeusedinsupportof10CFR50,AppendixGanalysis.

Regulatory Guide1.99<"providesameansforpredicting RT>>~shiftbasedonthe~~~~~chemicalcontentofthevesselmaterialandtheneutronfluence.TheGuidealsopresentsamethod,Regulatory Position2.1,bywhichcrediblesurveillance datacanbeusedtorefinetheshiftprediction andtoreducetheuncertainty factor(margin)whichmustbeaddedtothemeanpredicted shift.Adichotomy existsgivensurveillance programsdesignedinthe1960'sandearly1970'sandthecurrentRegulatory Guide1.99"'.Themeansbywhichsurveillance materials wereselectedforencapsulation differssubstantially fromthemethodcurrently prescribed intheGuide.Forexample,forthePalisades reactorvessel,thebeltlineplateswerecomparedonthebasisofdropweightNDTTandtheCharpyimpacttestresults;+

theplatewiththehighestNDLTandthehighesttemperature atthe30ft-lbCharpyimpactvaluewasselectedforinclusion inthesurveillance program.Theassumption wasthatdifferences intheinitialtoughness wouldberetainedafterirradiation forplatespurchased tothesamespecification.

Itwasnotrecognized atthetimethatsmalldifferences inresidualchemistry contentcouldresultinalargedifference inirradiation sensitivity (NDTTshift).Ifthesameplateswereevaluated usingthecurrentRegulatory Guide1.99"',amorerigorousanalysiswouldbeperformed onthebasisofRTNpyandirradiation inducedchangesinthetransition temperature (shift)anduppershelfenergy.Theplateselectedonthisbasisforthesurveillance programwouldverylikelybedifferent fromtheoneoriginally selected.

Therefore, thepost-irradiation surveillance platedatawouldnotbecrediblebecauseitwouldnotmeetthefirstRegulatory Guide1.99credibility criterion:

"Materials inthecapsulesshouldbethosejudgedmostlikelytobecontrolling withregardtoradiation embrittlement according totherecommendations ofthisguide.""'ence, thedichotomy exists;thenon-credible reactorvesselsurveillance datacannotbeusedtocomputethebest-fitchemistry factor,andanyfurtheruseofthesurveillance datamustbejustified totheNRCeventhoughthesurveillance programcomplieswiththeversionofASTME185ineffectatthetimetheprogramwasdesigned.

~~~~~Thissituation existsformanyreactorvesselsbecauseofdifferences inmethodstodefineinitialtoughness andtopredictshift.RT~~wasusedinthesurveillance materialselection processforthosevesselsbuilttotheSummer1972AddendatotheASMEBoilerandPressureVesselCode."@Forearliervessels,NDTl'raCharpyindextemperature wasusedtodifferentiate initialtoughness properties ofthecandidate materials.

Shiftpredictions formaterialselection werebasedonrangesofcoppercontent;separatetrendcurveswereusedfor0to0.10%Cu,0.11to0.15%Cu,andgreaterthan0.15%Cu.Typically, thebeltlineplatesfromonevesselwouldallfallwithinonerangeofcoppercontentand,therefore, bepredicted toexhibitthesameshift.Thebeltlineweldswouldhaveasimilarsituation.

Incontrast, Regulatory Guide1.99"'redictions arebasedonexplicitvaluesofcopperandnickelcontentsuchthateachbeltlineplateandweldwouldhaveauniquepredicted shift.Giventhemajordifferences inmethodsusedtoselectthesurveillance materialandpresentdaycriteria"'or identifying thecontrolling

material, theprobability ofhavingtheprecisecontrolling materialinthesurveillance capsuleislow.Asaconsequence, presentruleswillseverelylimitthenumberofreactorvesselstowhichRegulatory Position2.1tucanbeapplied.

ReactorvesselsdesignedandbuiltbyBabcock&Wilcoxencountered aproblemwiththesurveillance programwhichpromptedtheestablishment ofanintegrated surveillance program(seeforexampleReference 6).Theprobleminvolvedboththeforcedremovalofsurveillance capsulesfromseveralreactorvesselsandtheneedforcontinued surveillance ofthebeltlinematerials fromthosevessels.TheB&Wsituation wastheimpetusforSectionII.Cof10CFR50,AppendixH@whichdetailedrequirements andacceptance criteriaforestablishing anintegrated surveillance program.Thebasicapproachentailsirradiation ofrepresentative materialinahostreactorforusebyotherreactorshavingsimilardesignandoperating features.

Presumably, thatdatacouldalsobeusedinaccordance withRegulatory Position2.1<uforAppendixG"'nalyses.

IntheB&Wsituation, numerousvesselswerefabricated usingsimilarmaterials andprocesses, including thosevesselsmadeforuseinWestinghouse designedPWRs.SimilartoB&W,Combustion Engineering alsofabricated vesselsforWestinghouse.

Therefore, surveillance materials fromWestinghouse designedvesselsrepresent apotential sourceofdataonspecificheatsandtypesofvesselbeltlinematerials.

Establishment ofanintegrated surveillance programbetweentwovesselssuppliedbythesamefabricator could,innumerouscases,providesurveillance dataonthecontrolling vesselmaterialforoneorbothofthosevessels.IncontrasttotheB&Wsituation, wheresomevesselshadtohavethesurveillance capsulesremoved,alloftheC-EdesignedPWRsstillhavesurveillance capsules.

Therefore, measurements ofneutronflux,irradiation temperature, andsurveillance materialirradiation sensitivity canbeobtainedforeachC-Evessel.Thisprovidesforthemonitoring requiredbyAppendixH,"'ndimplementation ofanintegrated surveillance programcouldprovidethedataonthecontrolling materialasinputforanalysesrequiredbyAppendixG"'nd10CFR50.61.""

Theobjective ofthisreportistoestablish twoapproaches forimplementing Regulatory Position2.1"'orC-EdesignedPWRsforwhichthesurveillance programiscredibleinallrespectsexceptthatthecontrolling materialinthevesselisnotinthesurveillance program.IntheIntegrated Surveillance

Approach, dataforthecontrolling materialisobtainedfromanotherreactorvesselsurveillance program.IntheMarginReduction

Approach, theplant-specificdataareusedwhendataonthecontrolling materialareunavailable.

Bothapproaches areintendedtoaddresstheRegulatory Position2.1"'aseinwhich"...surveillance dataarecredibleinallrespectsexceptthatthe(surveillance) materialdoesnotrepresent thecriticalmaterialinthevessel..."

Theprimarypurposeistorealizeasfullyasreasonable thebenefitsfromthesurveillance programoncecertaincriteriahavebeensatisfied.

Thosecriteriaincludethesurveillance datacredibility factorsgiveninRegulatory Guide1.99<"and,whereapplicable, thecriteriagivenin10CFR50,AppendixH+foranintegrated surveillance program.Theaddedcertainty obtainedthroughsurveillance capsulemeasurements justifies realization ofthebenefitsfromapplication ofRegulatory Position10)Thepurposeofthissectionistodescribetherationale usedinestablishing theIntegrated Surveillance andMarginReduction Approaches.

'.(Notethatthesecondandthirdrationale elementsaredirectedprimarily attheIntegrated Surveillance Approach.)

Thethreeelementsaredetailedbelow.

PREDICTED VERSUSMEASUREDWELDRTNDTSHIFTRESULTS4003503002502000z1501000SURVEILLANCE DATAPEXERIMENTAL DATA(WELD-1,LCP)orr~rrQPOSITIOH2.1.RG'I.99REY.2CURVEFITTOSURVEILLANCE WELDDATAWITHlrr=28FBOUNDS500.10.20.40.60.81.02.04.06.08.010.0~FLUENCE(E>1MeV).10n/cm Table1 V.IERATEDREILLAEAPPRAHThepurposeofthissectionistoestablish thecriteriawhichneedtobeaddressed andtheprocedure tobefollowedinordertoutilizesurveillance datafromanotherreactorvesselinsupportofaRegulatory Position2.1<"analysis.

Theapproachcombinesthecredibility criteriaofRegulatory Guide1.99tuwiththeconceptofintegrated surveillance programsdefinedin10CFR50,AppendixH.o'riortoapplyingRegulatory Position2.1perthisapproachasshowninSectionV.E.,thefollowing mustbeestablished:

traceability ofthecontrolling material(SectionV.A.),thecredibility ofthesubjectvessel(SectionV.B.)andhostvesselsurveillance data(SectionV.C.),andthesimilarity oftheirradiation environment ofbothvessels(SectionV.D.).-A'<<h'dihhprogramisequivalent tothecontrolling materialinthesubjectvessel.

'ecVelrvillnDrediili-Thesurveillance datafromthesubjectreactorvesselmustbecredibleinallrespectsexceptthatthesurveillance materialdoesnotrepresent thecriticalmaterialinthevessel.Thisisestablished bysatisfying thefollowing fivecriteriawhicharetakenfromReference 1withmodifications toitems1and5:1.Materials inthecapsuleshallberepresentative ofthe,,reactor vesselbeltlinematerials, including bothbasemetalandweldmetal.[

2.Determination ofthe30ft-lbindextemperature andtheupper-shelf energyshallbedoneunambiguously forboththeirradiated andunirradiated Charpydata'.Twoormoresetsofpost-irradiation surveillance dataforbothbaseandweldmetalshallbeavailable fromthesubjectreactorvessel,andaRegulatory Position2.1analysisshallbeperformed.

Themeasurements shallbewithin+lo~ofthemeancurveoftheactualsurveillance data,wherea~is17'Fforbasemetaland28'Fforweldmetal."'f thefluencerangeistwoordersofmagnitude orgreater,themeasurements mustbewithin+2r~.<'>4.Theirradiation temperature oftheCharpyspecimens shallbewithinJ25'Fofthevesselwalltemperature atthecladding/base metalsurface."TheCharpyspecimentemperature shallbeestimated basedonevaluation ofthetemperature monitorsincludedinthesurveillance capsulesorfromheattransfercalculations.

Thevesselwalltemperature shallbebasedoncoldlegorvesselwallmeasurements.

5.Oneofthesurveillance capsulesusedintheevaluation shouldincludeCharpyspecimens fromastandardreference material.

(CEOGvesselsurveillance programsuseHSST01forreference material.)

Themeasuredshiftforthestandardreference materialshallfallwithinthescatterband(J2ogofthedatabaseforthatmaterialasgiveninFigure3.""C.HstReacrurveillance Dataribili-Theprincipal interestinthehostreactordataistheonesurveillance plateorweldrepresenting thesubjectreactor's controlling material.

Thefollowing criteriaarebasedonthefivecriteriafromReference 1,withmodifications toitems1,4and5.Eachofthefollowing criteriaaretobesatisfied toestablish thecredibility ofdataforthatonematerial:

1.Thetraceability betweenthecontrolling materialfromthesubjectreactorandsurveillance materialfromthehostreactoristohavebeenestablished asdetailedinV.A.2.Determination ofthe30ft-lbindextemperature andtheupper-shelf energyshallbedoneunambiguously forboththeirradiated andunirradiated Charpydata.<u3.Twoormoresetsofpost-irradiation surveillance dataforthecontrolling materialshallbeavailable fromthehostreactorvessel,andaRegulatory Position2.1analysisshallbeperformed.

Themeasurements shallbewithin+la~ofthemeancurveoftheactualsurveillance data,whereo~is17'Fforbasemetaland28'Fforweldmetal."'f thefluencerangeistwoordersofmagnitude orgreater,themeasurements mustbewithin+2a~.<'>4,Theirradiation temperature oftheCharpyspecimens shallbewithinJ25'Fofthevesselwalltemperature atthecladding/base metalsurface."'he Charpyspecimentemperature shallbeestimated basedonevaluation ofthe.temperature monitorsincludedinthesurveillance capsulesifavailable.

Thevesselwalltemperature shallbebasedoncoldlegorvesselwallmeasurements.

5.Standardreference material(SRM)isnotavailable insomehostreactorvesselsurveillance programs.

rHowever,ifSRMisavailable foroneormorehostreactorcapsules, themeasuredshiftfortheSRMshallfallwithinthescatterband(J2rgofthedatabaseforthatmaterialasgiveninFigure3.""

i25200IO7i50mta.aaouO100illI-CIlIcc50vv/'e/vv%Survoillanco CapoulooHSSTOZ0Survolllanco CapauloaHSST01h8SRXrradiationa(HSSTO?)VORR-PSFXrradlatlone(HSST03)i0075o50250.000.50i.00i.50Z.OO2.50"'3.003.504.004.505.00<Ei9Fluanco(6>i.0Hov)FIGURE3TRENDCURVEFORA533BREFERENCE MATERIALEmbrittlement oftheA533Breference materialrelativetothedraftReg.Guide1.99,Revision2.ThevaluesforHSST01andHSST03plates-are adjustedrelativetoHSST02platetoaccountfordifferences inchemistry.

Theupperandlowercurvesarethe34oFuncertainty bounds(20)specified byReg.Guide1.99.(Source:Reference

15)

D.IditinEnvirnmenmrin-Ascertain thattheirradiation environment forthehostreactorsurveillance capsuleiscomparable tothatforthesubjectreactorsurveillance capsuleusingthefollowing factorsandprovideaqualitative rankingofthetwocapsulesintermsofthesignificance ofanydifferences onRTNprshift.1.ReactorCoolantInletTemperature 2.NeutronFlux(E.liinfReulPiin21-Oncethefourpreceding itemshavebeensatisfactorily addressed, thehostreactorsurveillance dataforthecontrolling materialmaybeusedtodetermine theadjustedreference temperature forthatmaterialinaccordance withRegulatory Position2.1"'sfollows:

Theoverallequivalence ofthesubjectreactorvessel'scontrolling materialandthehostreactorvessel'ssurveillance materialwasestablished inSectionV.A.Ifthereportedcopperandnickelcontentofbothmaterials isidentical, thenproceedtostep2.If,however,theyarenotidentical, thenthemeasuredvaluesofshift,ART>>T,shallbeadjustedbymultiplying thembytheratioofthechemistry factorforthevesselmaterialtothatofthesurveillance materialinaccordance withRegulatory Position2.1.2.Fitthesurveillance datatoobtaintherelationship ofART>>Ttofluenceusingthefollowing equation:

Azr=(t"z)s<'-'""g'~

NDTwhere:CF=chemistry factorf=neutronfluence(10"n/cm',E)1Mev)Todoso,calculate thechemistry factor,CF,forthebestfltbymultiplying eachART>>T(ortheadjustedvaluesfromstep1)byitscorresponding fluencefactor,summingtheproducts, anddividingbythesumofthesquaresofthefluencefactors.Theresultant valueofCFisthentobeenteredintoequation1forcalculating ART>>T.Note:Ifthehostreactorsurveillance dataarelessthanpredicted, butthesubjectreactorsurveillance dataaregreaterthanpredicted, thenapplication oftheCFderivedfromthehostreactorcouldbenon-conservative forthesubjectreactor.Inthissituation, thehostreactorcalculated chemistry factorcanbeadjustedasfollows;CF(H)xQFF'~=AdjustedCFCF(S,P) where:CF(H)isthecalculated CFforthehostreactorfromstep2CF(S,C)isthecalculated CFforthecorresponding plateorweldforthesubjectreactorfollowing step2CF(S,P)isthepredicted CFforthesamesubjectreactormaterialbasedonTable1or2ofReference 1Thelargerofthetwovalues,AdjustedCForCF(H)shouldthenbeenteredintoequation1.3.Calculate marginasfollows:Margin=2or+a~22(2)where:0;=standarddeviation fortheinitialRT>>T0~=standarddeviation ford,RTNDT)gncaseswhereagenericvalueisassumedforSA533BClass1orSA302B(Modified) plates,0;istobedetermined basedonthevarianceofthedatausedtoderivethegenericvalue.)

Thestandarddeviation forshift,0~,canbereducedto8.5'Fforbasemetaland14'Fforweldsifthesurveillance datacredibility hasbeenestablished inaccordance withsectionsV.BandV.CperRegulatory Position2.1"'ndtheirradiation environments havebeenestablished tobecomparable inaccordance withSectionV.D.4.Calculate adjustedRT~(ART)asfollows:ART=RT~+hRT~~+Marginwhere:RTNDvinitialRTN~,measuredorgenericvalueb,RTND~=shift,usingrevisedchemistry factorinequation1Margin=valueusingequation2including valuesof0;and0~fromstep35.Documentresultsoftheevaluation following SectionV.AthroughV.E,including assumptions employedandconclusions reached.

VI.MARIREDTINAPPRAHTheprevioussectionaddressed thespecialcaseinwhichanintegrated surveillance programapproachcouldbeusedtoaugmentplant-specific surveillance data.Thepurposeofthissectionistoaddressthecaseinwhichsurveillance dataonthecontrolling materialisnotavailable fromeithertheplant-specific programoranotherreactorvessel,butthesurveillance dataarecredibleinallotherrespects.

Anapproachisgivenfordetermining howmuchthestandarddeviation fordRTND~,0~,canbereducedbasedonthedegreeofcredibility ofthesurveillance capsulemeasurements or,asphrasedinRegulatory Position2.1<","depending onwherethemeasuredvaluesfallrelativetothemeancalculated forthesurveillance materials".

Thefollowing procedure presentsarecommended approachforsatisfying Regulatory Position2.1"'nordertoreducethevalueof0~.Theprocedure whichfollowsaddresses twoissues,representative materials andpredictability ofthesurveillance measurements, asthebasisforreducingthevalueof0~.A,rnivM'Eachsurveillance programforaC-Edesignedreactorvesselincludesencapsulated Charpyspecimens fromaplate,weld,heat-affected-zone, andstandardreference material(SRM).Inaccordance withtheeditionofASTME185ineffectatthetime,thesurveillance materials (exclusive ofSRM)wereselectedtorepresent thereactorvesselbeltline.

Thesurveillance platewasselectedfromoneofthesix(typical) beitiineplates.[

Thesurveillance weldwasfabricated usingportionsoftwobeltlineplatesfollowing thesameprocedure andweldconsumables asoneofthebeltlineweldsInsummary911-RglGdjd199"'911*1jdgjggcredibility ofsurveillance data.ThefourRegulatory GuidecriteriadealingwithI)scatteroftheCharpydata,2)scatteraboutthedRTN~versusneutronfluencebestfitcurve,3)capsuleirradiation temperature, and4)SRMtestresultsshallbeevaluated.

Oncethosecriteriaaresatisfied datapredictability needstobeevaluated toprovidethebasisforreducingthevalueof0~.

C.AlicainfRelPiin11withMarinReduction

-Oncethetwopreceding itemshavebeensatisfactorily addressed, theknowninformation onthecontrolling materialmaybeusedtodetermine theadjustedreference temperature forthatmaterialinaccordance withRegulatory Position1.1"'sfollows:l.Obtainthevalueofd,RT>>~basedonthechemistry factorofthecontrolling materialandthefluenceusingthefollowing equation:

(peP0.28-0.10 logj)(1) where:CF=chemistry factorf=neutronfluence(10"n/cm',E)1Mev)Todoso,calculate thechemistry factor,CF,forthecontrolling materialusingtheknownchemicalcomposition asprescribed inRegulatory Position1.1ofReference 1.Iftheexactchemicalcomposition isnotknown,usetheguidelines ofReference 1todetermine theappropriate chemistry factor.2.Calculate marginasfollows:Margin=2ol+(RFa~)(2)where:0;=standarddeviation fortheinitialRTiT0~=standarddeviation forhRTNDTRF=reduction factorfromSectionVI.Bandasdescribed below(IncaseswhereagenericvalueisassumedforSA533BClass1orSA302B(Modified) plates,0;istobedetermined basedonthevarianceofthedatausedtoderivethegenericvalue.)

Thestandarddeviation indRT>>Y,0~,asdefinedinRegulatory Guide1.99is:0~=28'Fforweldsando~=17'Fforbasemetal.TheMarginReduction Approachmaythenbeappliedtothecontrolling materialbasedontheresultsoftestingoftheavailable crediblesurveillance datatoreducetherequiredvalueof0~asfollows:where:P=predicted shiftbasedonEquation2ofRegulatory Guide1.99+M=measuredshiftforbasemetal(longitudinalor transverse orientation) andweld0~=standarddeviation forART>>Ywhichis17'Fforplatesand28'Fforwelds<n3.Calculate adjustedRT>>Y(ART) asfollows:ART=RTNDz+B,RT>Dr+Marginwhere:RTNDART>>YMargininitialRT>>Y,measuredorgenericvalueshift,usingequation1valueusingequation2including valuesof0;and0~fromstep2 Th*Ifhp&igdibd&.TMshouldincludedemonstration thatthesurveillance materials arerepresentative ofthereactorvesselbeltlinematerials asdescribed inSectionVI.A.Thesurveillance datacredibility shallbeestablished usingdatasetsfromtwoormoresurveillance capsulesandthefourRegulatory Guide1.99criteriaidentified inVI.B.Finally,thesurveillance materialpredictability andtheresultant 0~reduction factorshallbeestablished following theprocedure giveninSectionVI.C.

rrcuRE4MARnxREnVCYrOx A.ppROA.eH NLIAdvancements intechnology forpredicting theextentofneutronirradiation embrittlement inpressurevesselsteelshavecausedsignificant changesinthedefinition ofthe"controlling" vesselbeltlinematerial.

Oneconsequence isthesurveillance capsulesdonotcontainthatcontrolling material.

Regulatory Position2.1ofRegulatory Guide1.99"'ermits theuseofdatafromthereactorvesselsurveillance programtorefineshiftpredictions butonlyforthoseprogramswhichincludethecontrolling vesselmaterial.

Thisreportprovidesthejustification foremploying surveillance datainsupportofvesselembrittlement analyseswhenthesurveillance dataarecredibleinallrespectsexceptthecontrolling materialisnotoneofthesurveillance programmaterials.

Approaches areprovidedforIntegrated Surveillance andMarginReduction tomaximizethevaluegainedfromplant-specific surveillance measurements.

IntheIntegrated Surveillance

Approach, dataforthecontrolling materialfromahostreactor~~~vesselsurveillance programisusedinconjunction withplant-specific datatoadjustthechemistry factorandreducetherequiredstandarddeviation forshift.ThisdatasharingbetweenWestinghouse andCombustion Engineering reactorvesselsurveillance programsisjustified basedonthefollowing rationale:

~~~TheIntegrated Surveillance Approachidentifies criteriatobeaddressed andaprocedure tofollowinordertoutilizethehostreactorsurveillance datainsupportofaRegulatory Position2.1<'>analysisforaC-Evessel.IntheMarginReduction

Approach, theplant-specific surveillance dataareusedtoreducethemarginforpredicted shiftofthecontrolling materialbasedonthepredictability ofthesurveillance measurements.

Thetwoapproaches presented inthisreportareapplicable tosurveillance programsforC-Edesignedreactorvessels,Theiruseisnotintendedforothervesseldesignsandsurveillance programsbecausetheapproaches werebasedinpartonpractices anddesigncharacteristics uniquetoC-E.~~

VILl.USNRCRegulatory Guide1.99,Revision2,"Radiation Embrittlement ofReactorVesselMaterials,"

May1988.2.AmericanSocietyforTestingandMaterials, "Standard PracticeforConducting Surveillance TestsforLight-Water CooledNuclearPowerReactorVessels" ASTME185-82,July1982.3.10CFRPart50,AppendixH,"ReactorVesselMaterials Surveillance ProgramRequirements,"

FederalRegister, Vol.48,No.104,May27,1983.4,10CFRPart50,AppendixG,"Fracture Toughness Requirements,"

Ibid.5."SummaryReportonManufacture ofTestSpecimens andAssemblyofCapsulesfor~~~~Irradiation Surveillance ofPalisades ReactorVesselMaterials,"

Combustion Engineering ReportP-NLM-019, April1971.6."Babcock&WilcoxOwnersGroupProgramforEvaluation ofReactorVesselProperties,"

BAW-1474, Rev.4,December1986.7.AmericanSocietyforTestingandMaterials, "Standard PracticeforCharacterizing NeutronExposures inFerriticSteelsinTermsofDisplacements perAtom(DPA),"ASTME693-79,August1979.8.W.N.McElroy,"LWRPressureVesselSurveillance Dosimetry Improvement Program:LWRPowerReactorSurveillance Physic-Dosimetry DataBaseCompendium,"

NUREG/CR-3319, preparedbyHanfordEngineering Development Laboratory, HEDL-TME85-3,August1985.

9.R.K.Nanstad,et.al,"Effectsof50'CSurveillance andTestReactorIrradiations onFerriticPressureVesselSteelEmbrittlement,"

presented atthe14thInternational ASTMSymposium ontheEffectsofRadiation onMaterials, Andover,Massachusetts, June1988.10."Evaluation oftheFirstMaineYankeeAccelerated Surveillance Capsule,"

EffectsTechnology, Inc.,ReportCR75-317, August15,1975.11."MaineYankeeNuclearPlantReactorPressureVesselSurveillance Program-Capsule263,"BattelleColumbusLaboratories ReportBCL-385-21, December12,1980.12."Analysis oftheMaineYankeeReactorVesselSecondAccelerated Surveillance Capsule,"

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NRLReport8136,October21,1977.14.J.R.Hawthorne, "NotchDuctility Degradation ofLowAlloySteelswithLow-to-Intermediate NeutronFluenceExposures,"

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January14,1980.15.F.W.Stallman, "Analysis oftheSA302BandSA533BStandardReference Materials inSurveillance CapsulesofCommercial PowerReactors,"

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ofMEBilerndPrerV1e,NewYork.

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0 APPENDIXASTATISTICAL ANALYSISPLATEDATABASEANDRESULTS A.1DATABASEAPPENDIXAThereactorvesselsurveillance platedatabaseusedinthestatistical analysisislistedinTablesA-1andA-2forCombustion Engineering andWestinghouse NSSSs,respectively.

-A Thelattertwotests(candd)wereperformed asanovercheck onthemoretraditional Fandttests.-A TablREACTORVESSELPLATESURVEILLANCE DATACOMBUSTION ENGINEERING NSSS

TableA-1(contin Table-2REACTORVESSELPLATESURVEILLANCE DATAWESTINGHOUSE NSSS TableA-tinued) 0 TableA-tinued)I00I TableA-ntinued) tinued)

TableA-3A302BPLATENICKELCONTENT~VeelYankeeRoweN/ABigRockH.B.RobinsonMri1IifiinUpperShellPlateTestMaterialYA9HSSTPlateSurveillance PlateW-9807-3W-9807-5W-9807-9W-10201-1 W-10201-2 W-10201-3 W-10201-4 W-10201-5 W-10201-6 iklnno0.210.190.180.180.100.100.150.110.2S0.080.090.120.09MeanValue:0.14%NiRange:0.08to0.25%NiStandardDeviation:

0.055%Ni FIGUREA-I(PRED-ACT)

CVTSHIFT:vaCUCONTENTC-E8Meat,inghouae PlacteaCuContent.(%)-A-12-oC-E+Meatinghnuse 0

HiGURKA-2(PRED-ACT)

CVTSHIFTusNXCONTENTC-EaNest.3.nghouse elatesNiCuntent'.(%)C-E+Mestinghnuse

'lGUREA-3(PRED-ACT)

CVTSHIFTvaFASTFLUENCEC-E8Mant'.inghouaa PlatenFaatFluence(x18".18n/cm"2)-A-14-oCF+Meetinghouae FIGUREA-4(PRED-ACT)

CVTSHIFTvsNEUTRONFLUXC-E8Masts.nghuusa PlatesFlux(xi.8"18/cm"2sec)oC-E+Mastinghouse FIGUREA-5(PRED-ACT)

CVTSHIFTFORC-EPLATESFv.aquanaut Hiat'.ngramGVTShif'tDif'f'erenae(Deg.F)-A FIGUREA-6(PRED-AGT)

GVTSHXFTFORMEST.PLATESFrequenc:gHint'ogramCVTShit'0Di,f'f'ar ant"a(Dag.F)

FIGUREA-7(PRED-ACT)

CVTSHIFTFORALLPLATESFrequenc:g Hi@tagl"am CVTShif'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)

CVTSHXFTFORPLATESNarmalProbabi1ity DenaityFunctinn(xe.eel)CVTShif'tDif'f'erence(Deg.F)-A APPENDIXBSTATISTICAL ANALYSISWELDDATABASEANDRESULTS B.1DATABASEAPPENDIXBThereactorvesselsurveillance welddatabaseusedinthestatistical analysisislistedinTablesB-1andB-2forCombustion Engineering andWestinghouse NSSSs,respectively.

-B Thelattertwotests(candd)wereperformed asanovercheck onthemoretraditional Fandttests.-B REACTORVESSELWELDSURVEILLANCE DATACOMBUSTION ENGINEERING NSSS TableB-1(continu TableB-2REACTORVESSELSURVEILLANCE DATAWESTINGHOUSE NSSS TableB-2(continuItxfOOI TableB-2(continu FIGUREB-1(PRED-ACT)

CVTSHIFTvsCUCONTENTC-E8Westinghouse WeldsCuContent(%)-B-10-0C-E+Westinghouse FIGUREB-2'C(PRED-ACT)

CVTSHXFTvsNXCONTENTC-E8Mestinghouse 4le1dsNiContent.(%)-B-11-C-E+Meat.inghuuae FIGUREB-3(PRED-ACT)

CVTSHXFTvsFASTFLUENCEC-E8Mest.inghuuse Me1dsFast'.Fluenc:e(xi,8"18n/t"m2)-B-12-oC-E+Mestinghouse FIGUREB-4(PRED-ACT)

CUTSHXFTvaNEUTRONFLUXC-E8Meetinghouse MeldsFlux(xi8"i,8n/am"2sec)-B-13-0QP+Meetinghouse FIGUREB-5(PRED-ACT)

CUTSHIFTFORC-EMELDSFrequency Histogram.

CUTShit't'.Dif'f'erence (Deg.F3-B FIGUREB-6(PRED-ACT)

CVTSHIFTFORMEST.MELDSFrequencLIHj.at'.ogr amCVTShif't.Dif'terence(Deg.F)-B FIGUREB-7(PRED-ACT)

CUTSHIFTFORALLMELDSFraquanc:LI HiatngramCUTShit'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-ACTi SHXFTFOR4lELDSNormalPI"ah@bi1itgDensityFunction<xe.eel>CVTShit'tDif'f'erence(Deg.F)-B APPENDIXCEFFECTOFWELDFLUXLOTONWELDCHEMICALCONTENT APPENDIXCC.IINTRODUCTION

]C.2WELDFLUXTYPE-C C.3WELDFLUXLOT-C TABLEC-1ExpectedEffectofFluxTypeontheAs-Deposited WeldProperties UsingtheSameWeldWire TABLEC-2As-Deposited WeldChemistries asaFunctionofFluxTyye-C As-Deposited WeldChemistries asaFunctionofFluxLot(WeldWireHeat¹4P7869)-C llte0e-