ML17228B047

Nonproprietary Version of Fracture Mechanics Evaluation of St Lucie Pressurizer Instrument Nozzles.

ML17228B047
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Site:	Saint Lucie
Issue date:	02/13/1995
From:	NANA A D, YOON K K BABCOCK & WILCOX CO.
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ML17228B046	List: ML17228B045 ML17228B047 ML17228B048 ML17228B049
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32-1235128-01, 32-1235128-01-R01, 32-1235128-1, 32-1235128-1-R1, NUDOCS 9503070359
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FLORIDAPOWERANDUGHTCOMPANYNUCLEARENGINEERINGDEPARTMENTP.O.Box14000JunoBeach,Florida33408St.LucieNuclearPowerPlantUnit2ATTACHMENTAFRACTUREMECHANICSEVALUATIONOFST.LUCIEPRESSURIZERINSTRUMENTNOZZLESPreparedbyB&WNUCLEARSERVICECOMPANYForSt.LucieNuclearPowerPlant10MilesSouthofFt.PierceonA1AFt.Pierce,Florida33034CommercialServiceDate:NRCDocketNumber.DocumentNumber.RevisionNumber.0August8,198350-38932-1235128-01Date:February13,1995iI9503070359950302PDR'ADOCK05000389PDR

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BWNT-2D697-2(11/B9)(BWNP-2D697-1)llfBBWNUCLEAR%MSERVICECOMPANYCALCULATIONSUMMARYSHEET(CSS)DOCUHENTIDENTIFIER32-1235128-01FMAna1sisofStLuciePressurizerInstrumentNozz1ePREPAREDBY:AshokD.NanaREVIEWEDBY:KennethK.Yoonnave~~COSTCENTER41020REF.PAGE(S)29SIGNATUREPrincia1EnineerSIGNATURETechnicalCcetantTMSTATEHENT:REVIEWERINDEPENDENCEPURPOSEANDSUHHARYOFRESULTS:Purpose,ToprovideaboundingflawevaluationforallsevenInstrument/temperature1"nozzlesinthepressurizer.Theevaluationwillconsideraconservativeflawsizeandwilldeterminetheacceptabilityofthepostulatedboundingflawforthefortyyeardesignlifeoftheplant.ThisflawevaluationwillbeperformedinaccordancewithIWB-3612ofSectionXI,ASMEBoilerandPressureVesselCode.Rev.1:Purposeofthisrevisionistoissuea"non-proprietary"versionofthedocument.SummaryofResultsThepostulatedflawsizeintheinstrument/temperaturenozzlesofSt.Luciewasfoundtobeacceptableforthedesignlifeoftheplant,perIWB-3612oftheASMECodeSectionXI.**BWNTNON-PROPRIETARY**THEFOLLOWINGCOHPUTERCODESHAVEBEENUSEDINTHISDOCUHENT:CODE/VERSION/REVCODE/VERSION/REVTHISDOCUHENTCONTAINSASSUHPTIONSTHATHUSTBEVERIFIEDPRIORTOUSEONSAFETY-RELATEDWORKYES()NO(X)PAGE"OF30 B&WNuclearTechnologies***BWNTNON-PROPRIETARY***32-1235128-01RECORDOFREVISIONSRevision0001DescritionofRevisionOriginalReleaseIssueof"Non-Proprietary"VersionDateReleased12/942/95Preparedby:A.D.NanaReviewedby:K.K.YoonDate:Feb.1995Date:Feb.1995Page2of30 B&WNuclearTechnologies***BWNTNON-PROPRIETARY***32-1235128-01TABLEOFCONTENTSPageEXECUTIVESUMMARY~~~~~~~~~~~~~~~~

41.0INTRODUCTION

.........................................~..61.1Assumptions~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~a62.0DESIGNINPUTS~~~~~~~0~~~~~~~~~~~~~~~~~~~~~073.0GEOMETRY,FLAWSIZEANDORIENTATION...................~..93.1GeometryofBoundingPressurizerNozzlePenetration...............93.2FlawSizeandOrientation.....~~~~~~~~~~~~~94.0MATERIALTOUGHNESS.................~..~~~~~~~~~~~135.0LOADINGCONDITIONS/STRESSES.............................145.1NormalandUpsetLoadingConditions........................145.2EmergencyandFaultedLoadingConditions.....................166.0FLAWEVALUATION...........,,.~~.................~176.1FlawEvaluationforNormalandUpsetLoadingConditionLoads..~~~.186.2FlawEvaluationforEmergencyandFaultedConditionLoads...~...,.2

27.0CONCLUSION

S~~~~~~~~~~~~~~~~~~~~~~2

88.0REFERENCES

~~~~~~~~~~~~~~~~~~~~~29Preparedby:A.D.NanaReviewedby:K.K.YoonDate:Feb.1995Date:Feb.1995Page3of30 B&WNuclearTechnologies***BWNTNON-PROPRIETARY***32-1235128-01EXECUTIVESUMMARYDuringthe1994refuelingoutageexternalleakagewasidentifiedatthepressurizerinstrumentnozzle"C"ofFloridaPower&LightCompany'sSt.LucieUnit2.SubsequentNDEidentifiedindicationsontheJ-weldsforthreeoffoursteamspaceinstrumentnozzles.Modificationsweremadeandjustificationsperformedtodeterminethepotentialforcrackgrowthduringplantoperation.Theevaluationperformedatthetimewasconservativelylimitedtoonefuelcycle.ThepurposeofthisevaluationwastojustifyacceptabilityofindicationsintheJ-weldforallseven1"'(instrument/temperature)nozzlesinthepressurizerfor30futureyearsofplantlife.Thetsevennozzlesarelocatedinvariousregionsofthepressurizerandarehorizontallyandverticallyoriented.Fouroftheinstrumentnozzlesarecontainedinthepressurizerheadsteam-spaceregion.Theremainingthreenozzlesarelocatedinthelowerregionofthepressurizer.Adetailedfiniteelementstressanalysiswasperformedthataccountedforallsevennozzlepenetrationregions.Thestressanalysisconsideredandevaluatedallsignificantdesigntransientsintheevaluation.Themostsignificanttransientproducedmaximumtensilestressesintheinsideofthepressurizershellatthenozzlepenetrationregion(J-weldlocation).Forthenormalandupsetconditioncategory,themaximumtensilestress(hoop)wasdevelopedwhenthemaximumpressureof2400psiaisreachedduringanupsetconditiontransient(abnormallossofloadtransient).Thistransientwasconservativelyevaluatedfor375cyclestoboundallfuturecyclesofplantheatup/cooldown.Fortheemergencyandfaultedcondition,thelossofsecondarypressuretransientwasevaluatedsincethesignificantcooldownduringthistransientproducedmaximumtensilestressesattheJ-weldlocation.Thefracturemechanicsanalysispostulatedaconservativeflawsizeanddetermineditsacceptabilityforthirtyfutureyearsofplantlife.Afatigueflawgrowthanalysiswasperformedforthenormalandupsetconditionloads.Consideringalltheapplicabledesigntransients,theinitialpostulatedflawsizeintheinstrument/temperaturenozzleoftheSt.LuciepressurizerwasPreparedby:A.D.NanaReviewedby:K.K.YoonDate:Feb.1995Date:Feb.1995Page4of30 BRWNuclearTechnologies***BWNTNON-PROPRIETARY***32-1235128-01determinedtoreachanacceptablefinalflawsize(af)attheendofthedesignlifeoftheplant.Themaximumappliedstressintensityfactoratthefinalflawsizeis78.0ksiVin.ThisresultsinasafetyfactorgreaterthantherequiredsafetyfactorofV10(3.16)perIWB-3612(a)ofASMECodeSectionXI.Fortheemergencyandfaultedcondition,themaximumappliedstressintensityfactoratthefinalflawsizeis76.8ksiVin.TheresultingsafetyfactorisgreaterthantherequiredsafetyfactorofV2(1.414)perIWB-3612(b)ofASMECodeSectionXI.Therefore,itisconcludedthatthepostulatedflawsizeintheinstrument/temperaturenozzleoftheSt.Luciepressurizerisacceptableforthedesignlifeoftheplant(thirtyfutureyears)perIWB-3612oftheASMECodeSectionXI.Preparedby:A.D.NanaReviewedby:K.K.YoonDate:Feb.1995Date:Feb.1995Page5of30 BAWNuclearTechnologies***BWNTNON-PROPRIETARY***32-1235128-0

11.0INTRODUCTION

Thepurposeofthisanalysisistoprovideaboundingflawevaluationforallseveninstrument/temperature1"nozzlesinthepressurizer.Theevaluationwillconsideraconservativeflawsizeandwilldeterminetheacceptabilityofthepostulatedboundingflawforthirtyfutureyearsofplantlife.ThisflawevaluationwillbeperformedinaccordancewithIWB-3612ofSectionXI,ASMEBoilerandPressureVesselCode.1.1Assumptionsa.Theflawtype,orientationandaspecificflawsizethatisconsideredconservativeispostulatedinthisanalysis.b.(Approachtakenforpostulationofflaw-BWNTProprietary)c.Threehundredandseventyfivefuturecyclesofheatup/cooldownareconservativelyassumedfortheremainingdesignlifeoftheplant.d.Eightfuturecyclesofpressuretestsat10%oftheoperatingpressure(2475psia)areassumedoverthenext30years.e.AspecificuppershelfvalueforK,~isusedforthenozzlepenetrationregion.ThistoughnessvalueisassumedfortheSA533GradeBClass1basematerialaboveacertaintemperaturerangewhenthematerialisveryductlie.Preparedby:A.D.NanaReviewedby:K.K.YoonDate:Feb.1995Date:Feb.1995Page6of30 B&WNuclearTechnologies***BWNTNON-PROPRIETARY***32-1235128-012.0DESIGNINPUTSa)GeometryofPressurizerNozzlePenetrationsThepenetrationconfigurationofthepressurizerupperheadsteamspaceinstrumentnozzles(four)withthemodifiednozzledesigniscontainedinDrawing2998-19321ofReference1.Thepenetrationconfigurationofthepressurizerbottomhead(two)instrumentnozzlesandsidetemperaturenozzleiscontainedinDrawing2998-18709ofReference2.minimumpressurizerheadthickness=3.875inminimumpressurizershellthickness=4.875inb)DesignTransients/NumberofCyclesThefollowinginformationwastakenfromReference3,withthetransientspecificinformationfromReference4(forthefortyyeardesignlifeoftheplant).i)500cyclesofnormalheatup/cooldownforthedesignlifeofthecomponent.ThenormaloperatingpressureperTable5.4-6ofReference3is2250psia.Atotalof480cyclesofupsetconditiontransients.Themaximumpressurerangeduringupsetconditiontransientis660psiandoccursbetween2400psia(abnormallossofturbinegeneratorload)and1740psia(reactortriptransient)withassociatedtemperaturedifferenceof50'Fduringlossofloadtransientiv)(Reference4).200cyclesofleaktestat2250psia(Reference4)Theremainderofthenormaloperatingtransientsi.e.15,000cyclesofpowerchangecyclesfrom15%to100%power,2,000cyclesofsteppowerchangesof10%ofthefullloadand1x10'yclesofnormalvariationsof100psiandtemperaturedifferencesoflessthan20'F(Reference4).v)5cyclesofemergencyconditiontransient(completelossofsecondarypressuretransient),giveninReference4.Preparedby:A.D.NanaReviewedby:K.K.YoonDate:Feb.1995Date:Feb.1995Page7of30 B&WNuclearTechnologies***BWNTNON-PROPRIETARY***32-1235128-01Sincetheanalysiswasperformedfor30futureyears,only75%oftheabovenumberofcyclesforagiventransientwereconsideredintheevaluation.c)MaterialsThepressurizerheadandshellmaterialismadeofSA-533GradeBClass1perReference1andAddendum2ofReference4.PerTable5.2-9ofReference5,theRTNDrofthepressurizershellmaterialis10'F.d)ApplicableASMESectionXICodePerReference6,theapplicableASMESectionXIcodeis1989Edition.Preparedby:A.D.NanaReviewedby:K.K.YoonDate:Feb.1995Date:Feb.1995Page8of30 B&WNuclearTechnologies***BWNTNON-PROPRIETARY***32-1235128-013.0GEOMETRY,FLAWSIZEANDORIENTATION3.1GeometryofBoundingPressurizerNozzlePenetrationThereareatotalofseven1"instrument/temperaturenozzlesinthepressurizerofSt.LucieUnit2asdepictedbythedrawingofReference2.Fouroftheinstrumentnozzleare'ontainedinthepressurizerupperheadsteamspaceregion.ThesenozzlesarehorizontallyorientedinthelowersphericalpartoftheupperheadasillustratedinFigure1.TheremainingthreenozzlesarelocatedinthelowerregionofthepressurizerasillustratedinFigure2.Twooftheinstrumentnozzles(verticallyoriented)arelocatedinthelowerheadofthepressurizer.Theseventhnozzleisa1"temperaturenozzlewhichislocatedinthelowercylindricalportionofthepressurizer.Thecylindricalportionofthepressurizerhasaminimumwallthicknessof4.875incheswhereastheminimumwallthicknessoftheupperandthelowerheadsis3.S75inches.ThestressanalysisofReference7tookeachofthesevennozzlepenetrationregionsintoconsiderationandconstructedanozzlepenetrationfiniteelementmodeltoboundallinstrument/temperaturesensingnozzlelocations.ForadditionaldetailsrefertoSection3.3ofReference7.3.2FlawSizeandOrientationItispostulatedthatthereexistsaspecifictypefiaw(asdepictedinFigure3)withaconservativeinitialflawdepth.Theorientationofthisflawwasassumedtobeinax,yplane(seeFigure3).ThisistheworsecaseflaworientationsincethemaximumstressisprimarilyduetopressureinducedstressascanbeseenfromtheresultsofthestressesalongtheflawplaneinSection6.0ofReference7.Theanalysiswillevaluatemaximumstressintensityfactorandperformfatigueflawgrowthanalysis.Preparedby:A.D.NanaReviewedby:K.K.YoonDate:Feb.1995Date:Feb.1995Page9of30 B&WNuclearTechnologies***BWNTNON-PROPRIETARY*"*32-1235128-01Figure1:UpperPressurizerRegion4gP>>~6CAIrn~m~Plgr4o~g4pggF445CThB.E.65Preparedby:A.D.Nana'eviewedby:K.K.YoonDate:Feb.1995Date:Feb.1995Page10of30 IIII~I~~II/~~II~f1I,Ie'e~'I~~.~~~~

BAWNuclearTechnologies***BWNTNON-PROPRIETARY***32-1235128-01Figure3:PostulatedFlaw"IntensionallyLeftBlank--containsBWNTProprietaryInformation"Preparedby:A.D.NanaReviewedby:K.K.YoonDate:Feb.1995Date:Feb.1995Page12of30 B&WNuclearTechnologies***BWNTNON-PROPRIETARY***32-1235128-014.0MATERIAITOUGHNESSThepressurizershellandheadisSA-533,gradeB,class1perReference1andAddendum2ofReference4.TheRT~rofthismaterialis10'F.AccordingtoIWB-3612,thearresttoughnesscurve,KI,inAppendixA,SectionXIofASMEBoiler&PressureVesselCode(Reference6)wasusedforthisevaluation.SincetheRTM,rofthepressurizeris10'F,thematerialisconsideredtobeattheuppershelfregionfortemperaturesabove192'F.Becausethemaximumstressisprimarilyduetopressure,thecorrespondingtemperaturesduringthetransientwhenthemaximumstressesoccurinthepressurizershell/headareabove500'F.Sincetheevaluationisbasedonaflawinthenozzlepenetrationregionofthebasemetalwithirradiationembrittlement,aspecificuppershelfvaluewasused.Itisnotedthatanyshiftduetoirradiationisnegligible,i.e.nochangesinRT>>~valueofthepressurizerwithincreasesinEffectiveFullPowerYears(EFPYs').Preparedby:A.D.NanaReviewedby:K.K.YoonDate:Feb.1995Date:Feb.1995Page13of30 B&WNuclearTechnologies***BWNTNON-PROPRIETARY***32-1235128-015.0LOADINGCONDITIONS/STRESSES5.1NormalandUpsetLoadingConditionsThestressesduetonormalandupsetconditionsarecontainedinSection6.0ofReference7.Thecompositetransientevaluatedintheanalysisconsistedof100'F/hrheatup,100%powersteadystatecondition,aboundingupsetconditiontransientanda200'F/hrcooldownrateasdescribedinSection5.0ofReference7.ThenormalandupsetconditiontransientcasesaresummarizedinTable1.TheresultsoftheanalysisinReference7showedthatthemaximumstressesoccurduringanupsetconditionwhenthepressure.Thenextlargeststressstateoccursduringsteadystateconditionswhenthepressureis2250psia.Thesemaximumstressstatesareprimarilyduetopressureinducedhoopstressandoccursattemperatureswellabove500'Fwhenthematerialisatupper-shelf.Transientcase2awasconservativelyevaluatedfor375cycles,inSection6.1,toboundthe360cyclesassociatedwithalltheupsetconditiontransientsaswellasthe375cyclesofplantstartupandshutdownand150cyclesofleaktests.Inaddition,8cyclesofpressuretestswereevaluated.Duringnormalcooldownthemaximumstressoccursat560'Fwhenthematerialisatupper-shelf.Toensurethatthefracturetoughnessmargin(factorofsafetyof>10perIWB-3612)ismaintained,throughouttheentirecooldowntransient,thetimeattheendof200'F/hrcooldownisalsoevaluated.Atthistime,thebulkfluidtemperatureisat70'Fandmaximumthermalstressesaredevelopedinthepressurizershell/head.Adequatefracturetoughnessmarginduringtheentireheatup/cooldownwasdemonstratedinSection6.1.Preparedby:A.D.NanaReviewedby:K.K.YoonDate:Feb.1995Date:Feb.1995Page14of30 BOWNuclearTechnologies***BWNTNON-PROPRIETARY***32-1235128-01Table1:NormalandUpsetConditionTransientCasesTransientCategory,CaseNormal,laNormal,lbNormal,lcNormal,ldDescriptionofTransientTimeEndof100'F/hrheatup(max.stressduringheatup)100%powersteadystateCooldownat560'F(max.stressduringcooldown)Cooldownat70'F(max.thermalstressduringcooldown)Pressure(psia)225022501133Temperature('F)65365356070NumberofCycles'75Normal,lePressureandtemperaturefluctuationsduringoperationd,P5100h,T520765,000Upset,2aUpset,2bUpset,2cTest,3Atmax.pressure(lossofturbinegeneratorload)53'Fstepup53'Fstepdown110%ofoperatingpressure2400240017402475653600-653653-6006533604Associatedwith30futureyearsofplantlife.Basedonconsidering75%ofthedesigncyclesgiveninReferences3and4.ThiscaseisnotspecificallyevaluatedinReference7.Conservativelyassumedtobeone-halfthestressesduetothetransientcases2band2c.11,250cyclesofplantloading/unloading,1,500cyclesof10%steploadincrease/decreaseand750,000cyclesofnormalpressurevariationareconservativelygroupedbythistransientcase.Thereareonly30cyclesoflossofturbinegeneratorload,however,300cyclesofreactortriptransientand30cyclesoflossofprimaryflowtransientareconservativelygroupedbythistransientcase.Preparedby:A.D.NanaReviewedby:K.K.YoonDate;Feb.1995Date:Feb.1995Page15of30 B&WNuclearTechnologies***BWNTNON-PROPRIETARY***32-1235128-01Inadditiontothe375cyclesofplantstartup/shutdownand8cyclesofpressureteststhereare11,250cyclesofplantloading/unloading,1,500cyclesof10%steploadincrease/decreaseand750,000cyclesofnormalpressurevariation(+/-100psi,+/-7'F)asgiveninReferences3and4.Reviewofthesetransientsshowthatthesetransientscanbegroupedasasingletransientwith765,000associatedcyclesofmaximumpressurevariationof100psiandtemperaturevariationoflessthan20'F.Theassociatedstressrangeduetothistransientshouldbelessthanone-halfthestressrangefortheupsetconditionstepchangetransientgiveninReference7.Thestepchangeconditiontransientconsideredpressurevariationof660psiandtemperaturevariationof53'F.Therefore,itisconservativetouseonehalfthestressrangeofthestepchangeupsetconditiontransient.5.2EmergencyandFaultedLoadingConditionsTheonlyemergencyandfaultedconditiondesigntransient(pressurizerpressureandtemperatureversustime)providedinReferences3and4isthelossofsecondarypressuretransient(anemergencyconditiontransient).ThefaultedconditiontransientsdescribedinReferences3and4are;i)thoseduetosafeshutdownearthquakewithnormaloperationatfullpowerandwithandwithoutpiperuptureconditionandii)thoseduetoLOCA.However,perTable3.9-38ofReference3,therearenoassociatedcyclesforthefaultedconditiontransients.Therefore,theonlytransientevaluated(inReference7)forthisloadingconditionisthelossofsecondarypressuretransient.Duringthistransientthepressurizerexperiencesasignificantcooldownrate.Asaresultofthiscooldownrate,hightensilestressesattheinsidesurfaceofthenozzlepenetrationregioncanbeproduced.ThisisreflectedinthestressresultsgiveninSection6.0ofReference7whichproducedthemaximumhoopsurfacestressamongstallthetransientsanalyzed.However,thestresses(hoop)alongthefiawplaneatthepostulatedflawsizeandbeyondareinfactlowerthanthoseduringsteadystateconditionat2250psia.Also,thematerialremainsatuppershelfsincetheminimumtransienttemperaturereachedduringthistransientis348'F.ThistransientcasewillnonethelessbeevaluatedinSection6.2.Thereare4cyclesassociatedwiththistransientcase.Preparedby:A.D.NanaReviewedby:K.K.YoonDate:Feb.1995Date:Feb.1995Page16of30 B&WNuclearTechnologies***BWNTNON-PROPRIETARY***32-1235128-016.0FLAWEVALUATIONAspecificflawtypeisassumedforthisanalysis.Thestressintensityfactor,KforthisflawgeometryisgiveninReference8.Theflawsolutiongiveninthisreferenceisutilizedtoevaluatethepostulatedflawintheoneinchpressurizerinstrument/temperaturenozzlesofSt.Lucieunit2.ThesolutiongivenaboveisapplicablefortheflawplaneillustratedinFigure3,Hence,thestressesareobtainedalongthisflawplaneasillustratedinFigure6.2ofReference7.Toaddressthestressintensityfactorsalongtheentirecrackfront,theinformationcontainedinReference9isutilized.Reference9hasevaluatedthestressintensityfactorsduetopressureinducedhoopstressesinanozzlecornerwithaquartercircularcrackgeometry.Threeflawsizeswithflawsizetothicknessratiosof0.15,0.26and0.34wereinvestigatedinthisstudy.Thisstudyprovidedthenon-dimensionalstressintensityfactorsasafunctionofthecrackfrontangle,8foreachofthethreeflawsizesasillustratedinFigure11ofReference9.Fromthisfigureitisclearthatthestressintensityfactornearthesurfacesofboththevesselandthenozzleboresideisslightlygreaterthanthestressintensityfactoralongtheflawplaneconsideredinthisanalysis.Forthetwolargerflawsizes(flawsizetothicknessratiocomparabletothisevaluation),thestressintensityfactornearthesurfacesisabout5to10percenthigherthanalongthepostulatedflawplane.Therefore,todeterminemaximumflawgrowthwithconsiderationofallcrackfrontangles,thestressintensityfactorsobtainedusingtheaboveequationswillbeincreasedby10percent.Thisisaconservativepractice.Thepostulatedflawintheinstrumentnozzleisevaluatedfornormal/upsetconditionandemergency/faultedconditionasgivenbelow.Preparedby:A.D.NanaReviewedby:K.K.YoonDate:Feb.1995Date:Feb.1995Page17of30 BAWNuclearTechnologies***BWNTNON-PROPRIETARY***32-1235128-016.1FlawEvaluationforNormalandUpsetLoadingConditionLoadsAsdiscussedinSection5.1,thefollowingboundingtransientcasewasanalyzedforthenormalandupsetconditionloading.Transientcase2awasevaluatedfor375cycles.Themaximumtensilestressstatealongtheflawplaneoccursduringthisconditionwhenthepressurizerisassumedtocyclefromaninitialstress-freestatetoamaximumpressureof2400psiat653'F.Thisstressstatewillbeconservativelyassumedtooccurforall375cyclesofnormalheatup/cooldown.Thisisnotanoverlyconservativeassumptionconsideringthefactthatthehoopstressesarelargelypressureinducedandtheupsetpressureisonlyslightlygreaterthanthesteadystatepressure.Asafirststep,athirdorderpolynomialequationtothestressesfromthefiniteelementanalysisresultswasmade.Theresultingstressesusingthepolynomialequationagreeverywellwiththefiniteelementmodel(FEM)stressesasillustratedinFigure4.ThenumericalvaluesforthesestressesarealsogiveninTable2.TheFEMstressesareforthemaximumupsetconditionpressurestressat2400psiaasgiveninTable6.4ofReference7.Thestressintensityfactor,Kfortheinitialflawsizeisdeterminedfirst.Nextafatigueflawgrowthanalysiswasperformedfor375cyclesusingtheabovemaximumupsetconditionstressesasgiveninTable3a.Thefatiguecrackgrowthrateis:da/dN=C,(hK,)"whereda/dNisthecrackgrowthrateinmicro-inchpercycle,d,K,isthemaximumK,minusminimumK,(inthiscasetheminimumK,iszero),C,andnarematerialconstantsandareobtainedfromthefatiguecrackgrowthratecurvewhichisgiveninFigureA-4300-1ofReference6.Fromthisfigure,itcanbeseenthatforasurfaceflaw(waterreactorenvironment)withanRratio50.25andd,K,219ksiVin,theapplicablematerialconstantsareC,=1.01x10'in/cycleandn=1.95.Theflawsizeattheendof375cycles,wasdeterminedandthemaximumappliedK,wascalculatedtobe75.30ksb/in.Also,8cyclesofpressuretestsat2475psigwereconsideredintheanalysis.Preparedby:A.D.NanaReviewedby:K.K.YoonDate:Feb.1995Date:Feb.1995Page18of30 0B&WNuclearTechnologies***BWNTNON-PROPRIETARY***32-1235128-01Figure4:FEMthroughwallstressesversuspolynomialfitstresses"IntensionallyLeftBlank--containsBWNTProprietaryInformation"Preparedby:A.D.NanaReviewedby:K.K.YoonDate:Feb.1995D*:~F*b.195Page19of30 BAWNuclearTechnologies***BWNTNON-PROPRIETARY***32-1235128-01Table2:SpreadsheetforthirdorderpolynomialequationandcomparisontoFEMstresses"IntensionallyLeftBlank--containsBWNTProprietaryInformation"Preparedby:A.D.NanaReviewedby:K.K.YoonDate:Feb.1995Date:Feb.1995Page20of30 B&WNuclearTechnologies***BWNTNON-PROPRIETARY***32-123512S-01Table2(cont'd)"IntensionallyLeftBlank--containsBWNTProprietaryInformation"Preparedby:A.D.NanaReviewedby:K.K.YoonDate:Feb.1995Date:Feb.1995Page21of30 BAWNuclearTechnologies***BWNTNON-PROPRIETARY***32-1235128-01Attheendof8cyclesofpressuretests,themaximumappliedK,=77.75ksiVin.Inaddition,thereare765,000cyclesofpressureandtemperaturevariations.TheRratio(K,;JK,~forthiscaseis0.95andsinceb,K,islessthan3.3ksiVin,theapplicablematerialconstantsareC,=1.2x10"in/cycleandn=5.95.Thefatigueflawgrowthdueto765,000cyclesoftheabovetransientiscomputedusingtheflawsizeaAer375cyclesofheatup/cooldownand8cyclesofpressuretestsastheinitialflawsize.TheresultsgiveninTable3balsoshowstheconsiderationof765,000cyclesdiscussedabove.Themaximumappliedstressintensityfactoratthefinalflawsizeis:K,(af)=78.0ksiVin.ThisresultsinasafetyfactorgreaterthantherequiredsafetyfactorofV10(3.16)perIWB-3612(a)ofReference6.Also,asdiscussedinSection5.1,toensurethatthefracturetoughnessmarginismaintained,throughtheentirecooldowntransient,thetimeattheendofthe200'F/hrcooldownisevaluated.ThemaximumappliedK,attheendofcooldownwasdeterminedtobe9.0ksiVin.Theassociatedfracturetoughness,K,iwasobtainedfromtheequationgivenonPageC-18ofReference8.Usingthisequation,thefracturetoughnessat60'Fis56.5ksiVin.Therefore,thereisasafetyfactorof6.28forthisconditionwhichissignificantlygreaterthantherequiredsafetyfactorofV'10perIWB-3612(a)ofReference6.6.2FlawEvaluationforEmergencyandFaultedConditionLoadsAsdiscussedinSection5.2,theonlyemergencyandfaultedconditiontransientrequiringevaluationisthelossofsecondarypressuretransientwhichhas4cyclesassociatedwithit.TheresultsoftheanalysisareprovidedinTable5.Sincethistransientoccursfollowingasteadystatecondition,hK,associatedwiththistransientisonly5.68ksiVin.Also,theflawgrowthassociatedwiththistransientisinsignificant.Themaximumappliedstressintensityfactoratthefinalflawsize(af)fortheemergencyandfaultedconditionis:K,(a,)=76.79ksiVin.Preparedby:A.D.NanaReviewedby:K.K.YoonDate:Feb.1995Date:Feb.1995Page22of30 B8rWNuclearTechnologies***BWNTNON-PROPRIETARY***32-1235128-01AspreviouslynotedinSection5.2,thematerialremainsatuppershelfduringthistransientTherefore,thisresultsinasafetyfactorfortheemergencyandfaultedconditionwhichissignificantlygreaterthantherequiredsafetyfactorofV2perIWB-3612(b)ofReference6.Preparedby:A.D.NanaReviewedby:K.K.YoonDate:Feb.1995Date:Feb.1995Page23of30 B&WNuclearTechnologies***BWNTNON-PROPRIETARY***32-123512S-01Table3a:FatigueFlawGrowthAnalysisfor375cyclesofnormalheatup/cooldown"IntensionallyLeftBlank--containsBWNTProprietaryInformation"Preparedby:A.D.NanaReviewedby:K.K.YoonDate:Feb.1995Date:Feb.1995Page24of30 BAWNuclearTechnologies***BWNTNON-PROPRIETARY***32-1235128-01Table3b:FatigueFlawGrowthAnalysis(cont'd)forremainingnormaloperatingtransients"IntensionallyLeftBlank--containsBWNTProprietaryInformation"Preparedby:A.D.NanaReviewedby:K.K.YoonDate:Feb.1995D.'Pb.5Page25of30 B&WNuclearTechnologies***BWNTNON-PROPRIETARY***32-1235128-01Table4:Summaryofflawsizesancheckwithacceptancecriteriafornormalandupsetcondition"IntensionallyLeftBlank--containsBWNTProprietaryInformation"Preparedby:A.D.NanaReviewedby:K.K.YoonDate:Feb.1995D*:~I'*t.Page26of30 B&WNuclearTechnologies***BWNTNON-PROPRIETARY***32-1235128-01Table5:Summaryofflawgrowthanalysisandcheckwithacceptancecriteriaforemergencyandfaultedcondition"IntensionallyLeftBlank--containsBWNTProprietaryInformation"Preparedby:A.D.NanaReviewedby:K.K.YoonDate:Feb.1995D*:~b.95Page27of30 BOWNuclearTechnologies***BWNTNON-PROPRIETARY***32-1235128-0

17.0CONCLUSION

SConsideringalltheapplicabledesigntransients,theinitialpostulatedflawsizeof0.875inchesintheinstrument/temperaturenozzleoftheSt.Luciepressurizerwasdeterminedtoreachafinalflawsize(af)of1.055inchesafter30futureyearsplantlife.Forthenormalandupsetconditionthemaximumappliedstressintensityfactoratthefinalflawsizeis78.00ksiVin.TheresultingsafetyfactorisgreaterthantherequiredsafetyfactorofV10(3.16)perIWB-3612(a)ofReference6.Theanalysisconsideredallcrackfrontanglestodeterminethemaximumappliedstressintesityfactorandensureboundingfatigueflawgrowth.Fortheemergencyandfaultedcondition,themaximumappliedstressintensityfactoratthefinalflawsizeis76.79ksiVin.TheresultingsafetyfactorisgreaterthantherequiredsafetyfactorofV2perIWB-3612(b)ofReference6.Therefore,itisconcludedthatthepostulatedflawsizeintheinstrument/temperaturenozzleoftheSt.LuciepressurizerisacceptableforthethirtyfutureyearssofplantlifeperIWB-3612oftheASMECodeSectionXI.Preparedby:A.D.NanaReviewedby:K.K.YoonDate:Feb.1995Date:Feb.1995Page28of30 BOWNuclearTechnologies***BWNTNON-PROPRIETARY***32-1235128-0

18.0REFERENCES

1.'loridaPower&LightDrawingNo.2998-19321,Rev.0,"TopHeadInstrumentNozzlesRepair".2.'loridaPower&LightDrawingNo.2998-18709,Rev.1,"PressurizerGeneralArrangement".3.BWNTDocument38-1210589-00,"PressurizerInstrumentNozzles,FMDesignInput,"forSt.LucieUnit2,dated11/11/94(FP&LNumberJPN-PSLP-94-603,File:PSL-100-14).4.BWNTDocument38-1210588-00,"PressurizerInstrumentNozzles,FMDesignInput,"forSt.LucieUnit2,dated11/11/94(FP&LNumberJPN-PSLP-94-631,File:PSL-100-14).5.'t.LucieUnit2UpdatedFinalSafetyAnalysisReport,throughAmendmentNo.9,datedOctober1994.6.ASMEBoilerandPressureVesselCode,SectionXI,1989Edition.7.BWNTDocument32-1235127-00,"StressesforSt.LucieUnit2,PressurizerLEFM,"byA.M.Miller,datedNovember1994(BWNTPROPRIETARYDOCUMENT).8.SourceReferenceforFManalysisapproachusedinanalysis.FManalysisapproachconsidered"BWNT-PROPRIETARY".9.SourceReferenceforFManalysisapproachusedinanalysis.FManalysisapproachconsidered"BWNT-PROPRIETARY".Preparedby:A.D.NanaReviewedby:K.K.YoonDate:Feb.1995Date:Feb.1995Page29of30 B&WNuclearTechnologies***BWNTNON-PROPRIETARY***32-123512S-01Referencesmarkedwithan"asterisk"areretrievablefromtheUtilitiesRecordSystem.AuthoridProjectManager'sSignaturePreparedby:A.D.NanaReviewedby:K.K.YoonDate:Feb.1995Date:Feb.1995Page30of30