ML17228B235

Fm Analysis of St Lucie Pressurizer Instrument Nozzle.

ML17228B235
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Site:	Saint Lucie
Issue date:	07/11/1995
From:	NANA A D, YOON K K BABCOCK & WILCOX CO.
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Shared Package
ML17228B236	List: L-95-220, Forwards Suppl to ISI Plan Second ten-yr Interval Revised Stress & Fracture Mechanics Evaluations Pressurizer Instrument Nozzles ML17228B235 ML17228B237
References
32-1235128-02, 32-1235128-2, NUDOCS 9508100179
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BNT-20697-2 (11/B9)(BNHP.20697.1)

IljBBMINUCI.EAR%MSERll!CECOMPANYCALCULATION"SUMMARY SHEET(CSS)DOCUHENTIDENTIFIER 32-1235128-02 FMAna1sisofStLuciePressurizer Instrument Nozz1ePREPAREDBY:AshokD.NanaCOSTCENTER41020REFTPAGE(S)SIGNATURE TITLEPrincialEnineerREVIENEOBY:KennethK.Yoon'IGNATURE

/A/01$7//F95TTTRETechnical nenltant01$7II'HSTATEHENT:

REVIENERINDEPENDENCE PURPOSEANDSUHHARYOFRESULTS:PurposeToprovideaboundingflawevaluation forthesix1"instrument nozzleslocatedinthespherical headsofthepressurizer.

Theevaluation willconsideraconservative flawsizeandwilldetermine theacceptability ofthepostulated boundingflawforthefortyyeardesignlifeoftheplant(30futureyears).Thisflawevaluation willbeperformed inaccordance withIWB-3612ofSectionXI,ASMEBoilerandPressureVesselCode.SummaryofResultsThepostulated flawsizeof0.875inchesintheinstrument nozzles(6)ofthespherical headsoftheSt.LucieUnit2pressurizer wasfoundtobeacceptable forthedesignlifeoftheplant,perIWB-3612oftheASMECodeSectionXI.***BWNTNON-PROPRIETARY

• • • THEFOLLOJING COHPUTERCODESHAVEBEENUSEDINTNISDOCUMENT:

CODE/VERSION/REVCODE/VERSION/REVTHISDOCUHENTCONTAINSASSUHPTIONS THATHUSTBEVERIFIEDPRIORTOUSEONSAFETY-RELATED IIORK"-'P508100179-950802 PDRADOCK05000389

9PDRYES()NO(X)PAGE1GF29 B&WNuclearTechnologies 1***BWNTNON-PROPRIETARY

• • • 32-1235128-02 RECORDOFREVISIONS Revision000102DescritionofRevisionOriginalReleaseIssueof"Non-Proprietary" VersionRe-analysis considering onlytheinstrument nozzles(6)locatedinthespherical headsand.usingfracturetoughness valueof200ksiVinDateReleased12/947/95Preparedby:A.D.NanaReviewedby:K.K.YoonD:~JI995D':~JI1995Page2of29 BA&NuclearTechnologies

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• • • 32-1235128-02 TABLEOFCONTENTSPageEXECUTIVE SUMMARY

1.0INTRODUCTION

1.1Assumptions 2.0DESIGNINPUTS~~~~I73.0GEOMETRY, FLAWSIZEANDORIENTATION..........

3.1GeometryofBoundingPressurizer NozzlePenetration...

3.2FlawSizeandOrientation

.......94.0MATERIALTOUGHNESS

...135.0LOADINGCONDITIONS/STRESSES

~~5.1NormalandUpsetLoadingConditions

~~~~~~0~~~~14~~~~~~~~145.2Emergency andFaultedLoadingConditions...........

166.0FLAWEVALUATION.....................

'.~..'...............

176.1FlawEvaluation forNormalandUpsetLoadingCondition Loads6.2FlawEvaluation forEmergency andFaultedCondition Loads.....

182

07.0CONCLUSION

S 2

78.0REFERENCES

28Preparedby:A.D.NanaReviewedby:K.K.YoonDate:June1995Date:June1995Page3of29 B&WNuclearTechnologies

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• • • 32-1235128-02 EXECUTIVE SUMMARYDuringthe1994refueling outageexternalleakagewasidentified atthepressurizer instrument nozzle"C"ofFloridaPower&LightCompany's St.LucieUnit2.Subsequent NDEidentified indications ontheJ-weldsforthreeoffoursteamspaceinstrument nozzles.Modifications weremadeandjustifications perforined todetermine thepotential forcrackgrowthduringplantoperation.

Theevaluation performed atthetimewasconservatively limitedtoonefuelcycle.Thepurposeofthisevaluation wastojustifyacceptability ofindications intheJ-weldforthesix1"instrument nozzlesinthepressurizer for30futureyearsofplantlife.Thesixnozzlesarelocatedinvariousregionsofthepressurizer andarehorizontally andvertically oriented.

Fouroftheinstrument nozzlesarehorizotally orientedandcontained inthepressurizer headsteam-spaceregion.Theremaining twonozzlesarevertically orientedandlocatedinthelowerheadofthepressurizer.

Adetailedfiniteelementstressanalysiswasperformed thataccounted forallsixnozzlepenetration regions.Thestressanalysisconsidered andevaluated allsignificant designtransients intheevaluation.

Themostsignificant transient producedmaximumtensilestressesintheinsideofthepressurizer shellatthenozzlepenetration region(J-weldlocation)

~Forthenormalandupsetcondition

category, themaximumtensilestress(hoop)wasdeveloped duringanupsetcondition reactortriptransient (lossofloadtransient).

Thistransient wasconservatively evaluated for375cyclestoboundallfuturecyclesofplantheatup/cooldown.

Fortheemergency andfaultedcondition, thelossofsecondary pressuretransient wasevaluated sincethesignificant cooldownduringthistransient producedmaximumtensilestressesattheJ-weldlocation.

Thefracturemechanics analysispostulated anozzlecornerflawwithaconservative flawsizeanddetermined itsacceptability forthirtyfutureyearsofplantlife.Anozzlecornerflawwithaninitialflawsizeof0.875incheswaspostulated intheanalysis.

Theflawsizeisconsidered toboundthestructural andbuttering welddeptharoundthenozzlearea.AfatigueflawgrowthPreparedby:A.D.NanaReviewedby:K.K.YoonDate:June1995Date:June1995Page4of29 B&WNuclearTechnologies

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• • • 32-1235128-02 analysiswasperformed forthenormalandupsetcondition loads.Considering alltheapplicable designtransients, theinitialpostulated flawsizeof0.875inchesintheinstrument nozzleoftheSt.Luciepressurizer wasdetermined toreachafinalflawsize(af)of0.966inchesattheendofthedesignlifeoftheplant.Themaximumappliedstressintensity factoratthefinalflawsizeis46.42ksiVinandresultsinasafetyfactorof4.31.Thissafetyfactorisgreaterthantherequiredsafetyfactorof410(3.16)perIWB-3612(a) ofASMECodeSectionXI.Fortheemergency andfaultedcondition, themaximumappliedstressintensity factoratthefinalflawsizeis84.6ksiVinandresultsinasafetyfactorof2.36.ThissafetyfactorisgreaterthantherequiredsafetyfactorofV2(1.414)perIWB-3612(b) ofASMECodeSectionXI.Therefore, itisconcluded thatthepostulated flawsizeintheinstrument nozzleoftheSt.Luciepressurizer isacceptable forthedesignlifeoftheplant(thirtyfutureyears)perIWB-3612oftheASMECodeSectionXI.Preparedby:A.D.NanaReviewedby:K.K.YoonDate:June1995Date:June1995Page5of29 B&WNuclearTechnologies

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1.0INTRODUCTION

Thepurposeofthisanalysisistoprovideaboundingflawevaluation.

forsixoftheseveninstrument/temperature 1"nozzlesinthepressurizer.

Allthesixnozzlesarelocatedinthespherical headsofthepressurizer.

Theevaluation willconsideraconservative flawsizeandwilldetermine theacceptability ofthepostulated boundingflawforthirtyfutureyearsofplantlife.Thisflawevaluation willbeperformed inaccordance withIWB-3612ofSectionXI,ASMEBoilerandPressureVesselCode.1.1Assumptions a.Anozzlecornerflawwithaninitialfiawsizeof0.875inchispostulated'n thisanalysis.

Thisflawsizeisconsidered toboundthestructural andbuttering welddeptharoundthenozzlearea.b.Itisassumedthatthepostulated flawcoverstheentireSMAWI-182weldregionsothatprimarywaterstresscorrosion cracking(PWSCC)isnolongeractiveforthepressurizer.

c.Threehundredandseventyfivefuturecyclesofheatup/cooldown areconservatively assumedfortheremaining designlifeoftheplant.d.Eightfuturecyclesofpressuretestsat10%oftheoperating pressure(2475psia)areassumedoverthenext30years.Preparedby:A.D.NanaReviewedby:K.K.YoonDate:June1995Date:June1995Page6of29 BAWNuclearTechnologies I***BWNTNON-PROPRIETARY

• • • 32-1235128-02 2.0DESIGNINPUTSa)GeometryofPressurizer NozzlePenetrations Thepenetration configuration ofthepressurizer upperheadsteamspaceinstrument nozzles(four)withthemodifiednozzledesigniscontained inDrawing2998-19321 ofReference 1.Thepenetration configuration ofthepressurizer bottomhead(two)instrument nozzlesiscontained inDrawing2998-18709 ofReference 2.minimumpressurizer headthickness

=3.875inb)DesignTransients/Number ofCyclesThefollowing information wastakenfromReference 3,withthetransient specificinformation fromReference 4(forthefortyyeardesignlifeoftheplant).i)500cyclesofnormalheatup/cooldown forthedesignlifeofthecomponent.

Thenormaloperating pressureperTable5.4-6ofReference 3is2250psia.ii)Atotalof480cyclesofupsetcondition transients.

Themaximumpressurerangeduringupsetcondition transient is660psiandoccursbetween2400psia(abnormal lossofturbinegenerator load)and1740psia(reactortriptransient) withassociated temperature difference of50'Fduringlossofloadtransient (Reference 4).iii)200cyclesofleaktestat2250psia(Reference 4)iv)Theremainder ofthenormaloperating transients i.e.15,000cyclesofpowerchangecyclesfrom15%to100%power,2,000cyclesofsteppowerchangesof10%ofthefullloadand1x10'yclesofnormalvariations of100psiandtemperature differences oflessthan20'F(Reference 4).v)5cyclesofemergency condition transient (complete lossofsecondary pressuretransient),

giveninReference 4.Sincetheanalysiswasperformed for30futureyears,only75%oftheabovenumberofcyclesforagiventransient wereconsidered intheevaluation.

Preparedby:A.D.NanaReviewedby:K.K.YoonDate:June1995Date:June1995Page7of29

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• • • 32-1235128-02 c)Materials Thepressurizer headandshellmaterialismadeofSA-533GradeBClass1perReference 1andAddendum2ofReference 4.PerTable5.2-9ofReference 5,theRTpyofthepressurizer shellmaterialis10'F.d)Applicable ASMESectionXICodePerReference 6,theapplicable ASMESectionXIcodeis1989Edition.Preparedby:A.D.NanaReviewedby:K.K.YoonDate:June1995Date:June1995Page8of29 7I B&WNuclearTechnologies

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• • • 32-1235128-02 3.0GEOMETRY, FLAWSIZEANDORIENTATION 3.1GeometryofBoundingPressurizer NozzlePenetration Therearesix1"instrument nozzlesinthepressurizer ofSt.LucieUnit2asdepictedbythedrawingofReference 2.Fouroftheinstrument nozzlearecontained inthepressurizer upperheadsteamspaceregion.Thesenozzlesarehorizontally orientedinthelowerspherical partoftheupperheadasillustrated inFigure1.Theremaining twoinstrument nozzlesarelocatedinthelowerregionofthepressurizer asillustrated inFigure2.Thesenozzlesarevertically orientedandlocatedinthelowerheadofthepressurizer.

Theminimumwallthickness oftheupperandthelowerspherical headsis3.875inches.ThestressanalysisofReference 7tookeachofthesixnozzlepenetration regionsinthespherical headsintoconsideration andconstructed anozzlepenetration finiteelementmodeltoboundallsixinstrument nozzlelocations.

Foradditional detailsrefertoSection3.3ofReference 7.3.2FlawSizeandOrientation Itispostulated thatthereexistsanozzlecornerflaw(asdepictedinFigure3)withaninitialdepthequaltothestructural andbuttering welddeptharoundthenozzlearea.Therefore, aflawsizeof0.875inchesisassumed.Theorientation ofthisflawwasassumedtobeinthex,yplane(seeFigure3)whichisnormaltothehoopdirection.

Thisistheworsecaseflaworientation sincethemaximumstressisprimarily duetopressureinducedhoopstressascanbeseenfromtheresultsofthestressesalongtheflawplaneinSection6.0ofReference 7.Theanalysiswillevaluatemaximumstressintensity factorandperformfatigueflawgrowthanalysisbasedonconsideration ofallcrackfrontanglesi.e.from6equalto0degrees(vesselside)tothe45degreeflawplaneto90degrees(nozzleboreside).Preparedby:A.D.NanaReviewedby:K.K.YoonDate:June1995Date:June1995Page9of29

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• • • 32-1235128-02 Figure1:UpperPressurizer RegionUlQvZIEhr~~~mm>r4gP>>/gxmSE'he.R.(65 C~Preparedby:A.D.NanaReviewedby:K.K.YoonDate:June1995Date:June1995Page10of29 IIII~~I~~~~IPEI~'~.~I'~~~~~.~.~~~~~~

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• • • 32-1235128-02 Figure3:NozzleCornerFlawQpter)n/RL Nozzt.6PgasSua<<~~HGRbe-'/IPOSg~gAl6'DNozzleCoRNEP,FLAWZhl$7gUPTON!4Thlozz~E.C,Io.ld~wgx,ycoordinates intheplaneofthecrack845degreesPreparedby:A.D.NanaReviewedby:K.K.YoonDate:June1995Date:June1995Page12of29 BdkWNuclearTechnologies

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• • • 32-1235128-02

4.0 MATERIALTOUGHNESS

Thepressurizer shellandheadisSA-533,gradeB,class1perReference 1andAddendum2ofReference 4.TheRT>>ofthismaterialis10'F.According toIWB-3612, thearresttoughness curve,KI,inAppendixA,SectionXIofASMEBoiler&PressureVesselCode(Reference 6)wasusedforthisevaluation.

SincetheRTN>>ofthepressurizer is10'F,thematerialisconsidered tobeattheuppershelfregionfortemperatures above192'F.Becausethemaximumstressisprimarily duetopressure, thecorresponding temperatures duringthetransient whenthemaximumstressesoccurinthepressurizer shell/head areabove500'F.Anuppershelfvalueof200ksiVinwasconservatively usedintheanalysis.

Itisnotedthatanyshiftduetoirradiation isnegligible, i.e.nochangesinRT>>valueofthepressurizer withincreases inEffective FullPowerYears(EFPYs').

Preparedby:A.D.NanaReviewedby:K.K.YoonDate:June1995Date:June1995Page13of29 B&WNuclearTechnologies

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• • • 32-1235128-02 5.0LOADINGCONDITIONS/STRESSES 5.1NormalandUpsetLoadingConditions Thestressesduetonormalandupsetconditions arecontained inSection6.0ofReference 7.Thecomposite transient evaluated intheanalysisconsisted of100'F/hrheatup,100%powersteadystatecondition, aboundingupsetcondition transient (represented asa53'Fstep-down topressureof1740psiaanda53'Fstepupwithapressureof2400psia)anda200'F/hrcooldownrateasdescribed inSection5.0ofReference 7.Thenormalandupsetcondition transient casesaresummarized inTable1.TheresultsoftheanalysisinReference 7showedthatthemaximumstressesoccurduringanupsetcondition stepdowntransient (transient case2casgiveninTable1).Thenextlargeststressstateoccursduringsteadystateconditions whenthepressureis2400psia(transient case2a).Thesemaximumstressstatesoccursattemperatures wellabove500'Fwhenthematerialisatupper-shelf.

Transient case2cwasconservatively evaluated for375cycles(fromaninitialstress-free statetothemaximumupsetcondition),

inSection6.1,toboundthe360cyclesassociated withalltheupsetcondition transients aswellasthe375cyclesofplantstartupandshutdownand150cyclesofleaktests.Inaddition, 8cyclesofpressuretests(case3,Table1)wereevaluated.

Duringnormalcooldownthemaximumstressoccursat595'F(transient case1casgiveninTable1)whenthematerialisatupper-shelf.

Toensurethatthefracturetoughness margin(factorofsafetyos10perIWB-3612) ismaintained, throughout theentirecooldowntransient, thetimeattheendofthe200'F/hrcooldownisalsoevaluated (transient case1dasgiveninTable1).Atthistime,thebulkfluidtemperature isat70'Fandmaximumthermalstressesaredeveloped inthepressurizer shell/head.

Also,thefracturetoughness islow.However,thecomponent isdepressurized sothattheresulting stressesarenotsignificant ascanbeseeninSection6.0ofReference 7forthistransient case.Adequatefracturetoughness marginduringtheentireheatup/cooldown wasdemonstrated inSection6.1.Preparedby:A.D.NanaReviewedby:K.K.YoonDate:June1995Date:June1995Page14of29 B&WNuclearTechnologies

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• • • 32-1235128-02 Table1:NormalandUpsetCondition Transient CasesTransient

Category, CaseNormal,laNormal,lbNormal,lcNormal,ldDescription ofTransient TimeEndof100'F/hrheatup(max.stressduringheatup)100%powersteadystateCooldownat560'F(max.stressduringcooldown)

Cooldownat70'F(max.thermalstressduringcooldown)

Pressure(psia)225022501472Temperature

('F)65365359570NumberofCycles'75 Normal,lePressureandtemperature fluctuations duringoperation d,P5100b,T<20765,000Upset,2aUpset,2bUpset,2cTest,3Atmax.pressure(lossofturbinegenerator load)53'Fstepup53'Fstepdown110%ofoperating pressure2400240017402475653600-653653-6006533604Associated with30futureyearsofplantlife.Basedonconsidering 75%ofthedesigncyclesgiveninReferences 3and4.Thiscaseisnotspecifically evaluated inReference 7.Conservatively assumedtobeone-halfthestressesduetothetransient cases2band2c.11,250cyclesofplantloading/unloading, 1,500cyclesof10%steploadincrease/decrease and750,000cyclesofnormalpressurevariation areconservatively groupedbythistransient case.Thereareonly30cyclesoflossofturbinegenerator load,however,300cyclesofreactortriptransient and30cyclesoflossofprimaryflowtransient areconservatively groupedbythistransient case.Preparedby:A.D.NanaReviewedby:K.K.YoonDate:June1995Date:June1995Page15of29 BOWNuclearTechnologies

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• • • 32-1235128-02 Inadditiontothe375cyclesofplantstartup/shutdown (includes 360cyclesofupsetcondition transients) and8cyclesofpressureteststhereare11,250cyclesofplantloading/unloading, 1,500cyclesof10%steploadincrease/decrease and750,000cyclesofnormalpressurevariation

(+/-100psi,+/-7'F)asgiveninReferences 3and4.Reviewofthesetransients showthatthesetransients canbegroupedasasingletransient with765,000associated cyclesofmaximumpressurevariation of100psiandtemperature variation oflessthan20'F(transient caseleasdefinedinTable1).Theassociated stressrangeduetothistransient isgiveninTables6-14and6-15ofReference 7.5.2Emergency andFaultedLoadingConditions Theonlyemergency andfaultedcondition designtransient (pressurizer pressureandtemperature versustime)providedinReferences 3and4isthelossofsecondary pressuretransient (anemergency condition transient).

Thefaultedcondition transients described inReferenc'es 3and4are;i)thoseduetosafeshutdownearthquake withnormaloperation atfullpowerandwithandwithoutpiperupturecondition andii)thoseduetoLOCA.However,perTable3.9-3BofReference 3,therearenoassociated cyclesforthefaultedcondition transients.

Therefore, theonlytransient evaluated (in.Reference 7)forthisloadingcondition isthelossofsecondary pressuretransient.

Duringthistransient thepressurizer experiences asignificant cooldownrate.Asaresultofthiscooldownrate,hightensilestressesattheinsidesurfaceofthenozzlecornerregioncanbeproduced.

Thisisreflected inthestressresultsgiveninSection6.0ofReference 7whichproducedthemaximumhoopsurfacestressamongstallthetransients analyzed.

Thistransient casewillbeevaluated inSection6.2.Thereare4cyclesassociated withthistransient case.Preparedby:A.D.NanaReviewedby:K.K.YoonDate:June1995Date:June1995Page16of29 B&WNuclearTechnologies

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6.0 FLAWEVALUATION

Athreedimensional nozzlecornercrackispostulated forthisanalysis.

Thestressintensity factor,KforthisflawgeometryisgiveninReference 8andreportedbelow:K,=~iia[0.706A

+0.537(2a/m)A,

+OA48(a/2)A+0.393(4a/3n)A]whereAAAand A,arethepolynomial coefficients ofthestressprofileexpressed as:o(r)=+A,r+A~r+A,r'hethreedimensional nozzlecornerflawsolutiongivenaboveisutilizedtoevaluatethepostulated flawintheoneinchpressurizer instrument/temperature nozzlesofSt.Lucieunit2.Thesolutiongivenaboveisapplicable forthe45degreeflawplaneasillustrated inFigure3.Hence,thestressesareobtainedalongthisflawplaneasillustrated inFigure6.2ofReference 7.Toaddressthestressintensity factorsatothercrackfrontangles,theinformation contained inReference 9isutilized.

Reference 9hasevaluated thestressintensity factorsduetopressureinducedhoopstressesinanozzlecornerwithaquartercircularcrackgeometry.

Threenozzlecornerflawsizeswithflawsizetothickness ratiosof0.15,0.26and0.34wereinvestigated inthisstudy.Thisstudyprovidedthenon-dimensional stressintensity factorsasafunctionofthecrackfrontangle,eforeachofthethreeflawsizesasillustrated inFigure11ofReference 9.Fromthisfigureitisclearthatthestressintensity factornearthesurfacesofboththevesselandthenozzleboresideisslightlygreaterthanthestressintensity factoralongthe45degreeplane.Forthetwolargerflawsizes(flawsizetothickness ratiocomparable tothisevaluation),

thestressintensity factornearthesurfacesisabout5to10percenthigherthanalongthe45degreeplane.Therefore, todetermine maximumflawgrowthwithconsideration ofallcrackfrontangles,thestressintensity factorsobtainedusingtheaboveequations willbeincreased by10percent.Thisisaconservative practice.

Aninitialflawdepthof0.875inchesisassumedtoboundthestructural andbuttering welddeptharoundthenozzlearea(J-welds).

Thepostulated flawintheinstrument nozzleisevaluated fornormal/upset condition andemergency/faulted condition asgivenbelow.Preparedby:A.D.NanaReviewedby:K.K.YoonDate:June1995Date:June1995Page17of29 B&WNuclearTechnologies

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• • • 32-1235128-02 r6.1FlawEvaluation forNormalandUpsetLoadingCondition LoadsAsdiscussed inSection5.1,thefollowing boundingtransient casewasanalyzedforthenormalandupsetcondition loading.Transient case2c(reactortriptransient) wasevaluated for375cycles.Themaximumtensilestressstatealongtheflawplaneoccursduringthiscondition whenthepressurizer isassumedtocyclefromanintialstress-free state(0psiat70'F)toareactortriptransient.

Thisstressstatewillbeconservatively assumedtooccurforall375cyclesofnormalheatup/cooldown.

Asafirststep,athirdorderpolynomial equationtothestressesfromthefiniteelementanalysisresultswasmade.Thecoefficients forthepolynomial equationwereobtainedusingaleastsquareflit.Theresulting stressesusingthepolynomial equationagreeverywellwiththefiniteelementmodel(FEM)stressesasillustrated inFigure4.TheFEMstressesareforthemaximumupsetcondition pressurestressat2400psiaasgiveninTable6.4ofReference 7.Thestressintensity factor,Kfortheinitialflawsizeof0.875inchesis:K,(a;)=44.89ksiVinAfatigueflawgrowthanalysiswasperformed for375cyclesusingtheabovemaximumupsetcondition stressesasgiveninTable2a.Thefatiguecrackgrowthrateis:da/dN=C,(b,K,)"

whereda/dNisthecrackgrowthrateinmicro-inch percycle,b,K,isthemaximumK,minusminimumK,(inthiscasetheminimumK,iszero),C,andnarematerialconstants andareobtainedfromthefatiguecrackgrowthratecurvewhichisgiveninFigureA-4300-1ofReference 6.Fromthisfigure,itcanbeseenthatforasurfaceflaw(waterreactorenvironment) withanRratio50.25andb,K,219ksiVin,theapplicable materialconstants areC,=1.01x10'in/cycle andn=1.95.Theflawsizeattheendof375cycles,is0.94inchesandthemaximumappliedK,=46.00ksiVin.Also,8cyclesofpressuretestsat2475psiawerePreparedby:A.D.NanaReviewedby:K.K.YoonDate:June1995Date:June1995Page18of29 B&WNuclearTechnologies

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• • • 32-1235128-02 Figure4:FEMthroughwall stressesversuspolynomial fitstresses45000ForUpsetCondition StepDoomTransient FEMstressesPolyriomial-Fit-stresses--

3500030000COD.00250001500000.51.5Distance(s),along45degreeflawplanePreparedby:A.D.NanaReviewedby:K.K.YoonDate:Jurie1995Date:June1995Page19of29 1

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• • • .32-1235128-02 considered intheanalysis.

Theflawsizeattheendof8cyclesofpressuretests,is0.942incheswithamaximumappliedK,=43.26ksiVin.Inaddition, thereare765,000cyclesofpressureandtemperature variations (transient caseleofTable1).TheRratio(K,;JK,~forthiscaseis0.92andsinceb,K,islessthan2.9ksiVin,theapplicable materialconstants areC,=1.2x10"in/cycleandn=5.95.Thefatigueflawgrowthdueto765,000cyclesoftheabovetransient iscomputedusingtheflawsizeafter375cyclesofheatup/cooldown and8cyclesofpressuretests(0.942inches)astheinitialflawsize.TheresultsaregiveninTable2bwhichshowsthatafterconsideration of765,000cyclestheflawsizeis0.964inches.Inaddition, afterconsideration of4cyclesoflossofsecondary pressuretransient asgiveninTable4thefinalflawsize(af)is0.966inches.Themaximumappliedstressintensity factoratthefinalflawsizeis:K,(af)=46.42ksiVin.Sincetheuppershelftoughness is200ksiVin,thisresultsinasafetyfactorof4.31(asgiveninTable3)whichisgreaterthantherequiredsafetyfactorofv10(3.16)perIWB-3612(a) ofReference 6.Also,asdiscussed inSection5.1,toensurethatthefracturetoughness marginismaintained, throughtheentirecooldowntransient, thetimeattheendofthe200'F/hrcooldownisevaluated (transient case1dofTable1).ThemaximumappliedK,attheendofcooldown(70'F)wasdetermined tobe8.69ksiVin.Theassociated fracturetoughness, K,~,wasobtainedfromtheequationgivenonPageC-18ofReference 8.Usingthisequation, thefracturetoughness at(TRTNpr)=70'F-10'For60'Fis56.5ksiVin.Therefore, thereisasafetyfactorof6.50forthiscondition whichissignificantly greaterthantherequiredsafetyfactorofV'10perIWB-3612(a) ofReference 6.6.2FlawEvaluation forEmergency andFaultedCondition LoadsAsdiscussed inSection5.2,theonlyemergency andfaultedcondition transient requiring evaluation isthelossofsecondary pressuretransient whichhas4cyclesassociated withit.TheresultsoftheanalysisareprovidedinTable4.Thistransient occursfollowing asteadystatecondition.

Thed,K,associated withthistransient is44.84ksiVin.Theflawgrowthassociated Preparedby:A.D.NanaReviewedby:K.K.YoonDate:June1995Date:June1995Page20of29 B&WNuclearTechnologies

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• • • 32-1235128-02 withthistransient is2mils.Themaximumappliedstressintensity factoratthefinalflawsize(a,)of0.966inchesfortheemergency andfaultedcondition is:K~(a,)=84.6ksiVin.Aspreviously notedinSection5.2,thematerialremainsatuppershelfduringthistransient (K<<=200ksiVin).Therefore, thisresultsinasafetyfactorof2.36fortheemergency andfaultedcondition whichisgreaterthantherequiredsafetyfactorofV'2perIWB-3612(b)ofReference 6.Preparedby:A.D.NanaReviewedby:K.K.YoonDate:June1995Date:June1995Page21of29 B&WNuclearTechnologies

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• • • 32-1235128-02 Table2a:FatigueFlawGrowthAnalysisfor375cyclesofnormalheatup/cooldown FatigueFlawGrowthAnalysisofPostulated NozzleCornerCrackai0.875inincrement=

0.0 05inGEOMETRIC

FACTORSGO=1.251G1=0.606G2~0.397G3~0.296FordK>STRESSAOA1A2A3FACTORS40.21-12.22-1.531.26dN=C1m=R=Kmin=Kmax=KI=GO*AO*a(1/2)+G1*A1*a" (3/2)+G2*A2+a" (5/2)+G3*A3*a (7/2)Factorforworsecaseflawangle=1.119ksidin375cycles1.01E-07in/cycle1.9500.00ksi*in"0.544.98ksi*in"0.5 KIA=Safetyfactor=200ksi*in"0.53'6ai(in)aj(in)FatigueGroup1KI(~a)C1(dKI)"mdNksidinin/cyclecyclesTotaldNcyclesCheckKIA/KIAccept70.8750.8800.8850.8900.8950.9000.9050.9100.9150.9200.9250.9300.9350.8750.8800.8850.8900.8950.9000.9050.9100.9150.9200.9250.9300.9350.9400.9544.8944.9845.0745.1545.2445.3345.4145.5045.5845.6745.7545.8445.9246.0046.161.69E-041.70E-041.70E-041.71E-041.71E"041.72E-041.73E-041.73E-041.74E-041.75E"041.75E-041.76E-041.76E-041.78E-0429.629.529.429.329.229.028.928.828.728.628.528.428.329.659.188.5117.7146.9175.9204.9233.7262.4291.1319.6348.0376.4continuecontinuecontinuecontinuecontinuecontinuecontinuecontinuecontinuecontinuecontinuecontinuestop4.454'44.434.424.414.404.404.394.384.374.364.364.354.33OKOKOKOKOKOKOKOKOKOKOKOKOKOKPreparedby:A.D.NanaDn'ltl&'l%>Drl hvKK'OOnDate:June1995Date;June1995Page22of29 BOWNuclearTechnologies

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• • • 32-1235128-02 Table2b:FatigueFlawGrowthAnalysis(cont'd)forremaining normaloperating transients For8cyclesofpressuretestsat110%-ofoperating pressureor2475psigStressFactorsfor2400psiareratioedby(2475/2400) 1.031STRESSFACTORSFordK>19ksi~inAO=34.00dN=8Al-1.98Cl~1.01E-07A2-3.51m1.95A31.37R0Kmin=0.00Kmax43.24KZ=Go*AO*a"(1/2)+G1*A1*a"(3/2)+G2*A2+a"(5/2)+G3*A3*a"(7/2)

Factorforworsecaseflawangle=1.1increment 0.001inai(in)aj(in)FatigueGroup2KE(aj)C1(dKE)"mdNksiginin/cyclecyclesTotaldNCheckcyclesKlA/KXAccept70.9400.9410.9410.94243.2443.261.56E-041.57E-046.396.396.4continue12.8stop4.634.62OKOKPreparedby:A.D.NanaReviewedby:K.K.YoonDate:June1995Date:June1995Page23of29 8'NuclearTechnologies

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• • • 32-1235128-02 Table2b:FatigueFlawGrowthAnalysis(cont'd)forremaining normaloperating transients For765,000cyclesofremaining normalcondition transients GOGlG2G31.2510.6060.3970.296GEOMETRIC FACTORSSTRESSAOAlA2A3FACTORSGroup132.54<<12.426.41-1.17-Group242.80-26.4213.41-2.70dN=Cl7650001.20E-115.95andR>0.650.92FordK<19ksiginKI~GO*AO*a"(1/2)+Gl*A1*a(3/2)+G2*A2*a(5/2)+G3*A3*a(7/2)Factorforflawangle~increment 0.002in1.1Kmin=43.88ksi*in"0.5 Stepuptransient-Kmax=47.95ksi*in"0.5 Stepdowntransient Factor=0.5ai(in)aj(in)Group1MinKI(aj)ksi<finnFatigueGroup3Group2MaxKI(aj)ksiJinDeltadKI(aj)Cl(dKI)"Mksiginin/cycledNcyclesTotaldNcyclesCheck0.9420.9440.9460.9480.9500.9520.9540.9560.9580.9600.9620.9440.9460.9480.9500.9520.9540.9560.9580.9600.9620.96438.0438.0738.1138.1438.1738.2038.2338.2738.3038.3338.3645.4445.4745.5045.5345.5645.5945.6245.6545.6845.7145.743.703.703.703.703.703.693.693.693.693.693.692.88E-OB2.87E-OB2.87E-OB2.87E-OB2.86E-OB2.86E-OB2.85E-OB2.85E-OB2.85E-OB2.84E-OB2.84E-OB69502.069596.269691.469787.769885.069983.370082.770183.070284.470386.970490.369502.0continue139098.1continue208789.6continue278577.3continue348462.2continue418445.6continue488528.2continue558711.2continue628995.7continue699382.5continue769872.8stopPreparedby:A.D.NanaPsvi<w<rlhv'KYnnnDate:June1995Date:June1995Pace24of29 B&WNuclearTechnologies

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• • • 32-1235128-02 Table3:Summaryofflawsizesancheckwithacceptance criteriafornormalandupsetcondition KIA200ksidinLumpedTransients:

Considers 375cyclesofworstupsetloads(coversfuturenormalheatupandcooldown) 8cyclesof2475psigpressuretestsaswellas765,000cyclesofremaining normalcondition transient cyclesai(in)aj(in)KI(aj)KIA/KI(aj) ksiPinTransient GroupASMEACCEPTCODE0.8750.9350.9410.9620.8800.9400.9420.9640.96644.9846.0043.2638.2046.424.454.354.625.244.31Beginning-1 endof1endof2endof3endofall3.163.163.163.163.16OKOKOKOKOKPreparedby:A.D.NanaDate:June1995Reviewedby:K.K.Yoon...Date:June19)5Page25of29

B&WNuclearTechnologies

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• • • 32-1235128-02 Table4:Summaryofflawgrowthanalysisandcheckwithacceptance criteriaforemergency andfaultedcondition For4cyclesoflossofsecondary pressuretransient GO~GlG2G3.~-1.2510.6060.3970.296GEOMETRIC FACTORSAoA3STRESSFACTORSGroup130.91A1-1.80A2"3.191.25Group2101.23-113.1456.99-12.44dN~Cl41.84E-071.950.471.82FordKv15ksidinKI~GO*AO*a"(1/2)+Gl*A1*a" (3/2)+G2*A2~a" (5/2)+G3*A3*a" (7/2)Kmin=Kmax39.76ksi*in"0.5 steadystateat2250psia84.60ksi+in"0.5 lossofsecondary pressureFactorincrement ai(in)forworsecaseflaw0.002inGroup1MinajKI(aj)(in)ksifinangleGroup2MaxKI(aj)ksiPinDeltadKI(aj)'l(dKI)"Mksi~inin/cyclecyclesTotaldNcyclesCheck0.96400.966039.7684.6044.843.06E-046.5'.5stop'Summaryoffinalflawsizesandcheckwithacceptance criteriaKIC200ksiSinForEmergency andFaultedCondition:

ai(in)af(in)KI(af)KIC/KI(af)ksidinASMEACCEPTCODE0.96400.966084.602.361.41OKPreparedby:A.D.NanaReviewedby:K.K.YoonDate:June1995Date:June1995Page26of29 Ol>"d B&WNuclearTechnologies

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• • • 32-1235128-02

7.0CONCLUSION

S Considering alltheapplicable designtransients, theinitialpostulated flawsizeof0.875inchesintheinstrument nozzleoftheSt.Luciepressurizer wasdetermined toreachafinalflawsize(a,)of0.966inchesafter30futureyearsplantlife.Forthenormalandupsetcondition themaximumappliedstressintensity factoratthefinalflawsizeis46.42ksiVinandresultsinasafetyfactorof4.31.Thissafetyfactorisgreaterthantherequiredsafetyfactorof410(3.16)perIWB-3612(a)ofReference 6.Theanalysisconsidered allcrackfrontanglestodetermine themaximumappliedstressintesityfactorandensureboundingfatigueflawgrowth.Fortheemergency andfaultedcondition, themaximumappliedstressintensity factoratthefinalflawsizeis84.6ksiVinandresultsinasafetyfactorof2.36.Thissafetyfactorisgreaterthantherequiredsafetyfactoros2perIWB-3612(b) ofReference 6.Therefore, itisconcluded thatthepostulated flawsizeintheinstrument nozzleoftheSt.Luciepressurizer isacceptable forthethirtyfutureyearsofplantlifeperIWB-3612oftheASMECodeSectionXI.Preparedby:A.D.NanaReviewedby:K.K.YoonDate:June1995Date:June1995Page27of29 B&WNuclearTechnologies I***BWNTNON-PROPRIETARY

• • • 32-1235128-02

8.0REFERENCES

1~'loridaPower&LightDrawingNo.2998-19321, Rev.0,"TopHeadInstrument NozzlesRepair".2.FloridaPower&LightDrawingNo.2998-18709, Rev.1,"Pressurizer GeneralArrangement".

3.BWNTDocument38-1210589-00, "Pressurizer Instrument Nozzles,FMDesignInput,"forSt.LucieUnit2,dated11/11/94(FP&LNumberJPN-PSLP-94-603, File:PSL-100-14).4.BWNTDocument38-1210588-00, "Pressurizer Instrument Nozzles,FMDesignInput,"forSt.LucieUnit2,dated11/11/94(FP&LNumberJPN-PSLP-94-631, File:PSL-100-14).5.'t.LucieUnit2UpdatedFinalSafetyAnalysisReport,throughAmendment No.9,datedOctober1994.6.ASMEBoilerandPressureVesselCode,SectionXI,1989Edition.7.BWNTDocument32-1235127-02, "Stresses forSt.LucieUnit2,Pressurizer LEFM,"byT.M.Wiger,datedJune1995.8.EPRIReportNumberNP-719-SR, "FlawEvaluation Procedures,"

witherrataforsubjectreportdatedApril14,1980,preparedbyASMETaskGrouponFlawEvaluation, ElectricPowerResearchInstitute, PaloAltoCalifornia, August1978.9."Solution ofThreeDimensional CrackProblemsusingtheBoundaryIntegralEquationMethod,"byJ.Heliot,R.LabbensandA.Pellissier-Tanon, presented attheSecondPreparedby:A.D.NanaReviewedby:K.K.YoonDate:June1995Date:June1995Page28of29 B&WNuclearTechnologies

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• • • 32-1235128-02 International Conference onNumerical MethodsinFractureMechanics, Swansea,GreatBritain,July1980.References markedwithan"asterisk" areretrievable fromtheUtilities RecordSystem.Authorized ProjectManager's Signature Preparedby:A.D.NanaReviewedby:K.K.YoonDate:June1995'ate:

June1995Page29of29 NUCLEARENGINEERING DEPARTMENT CoMPoNENT, SUPPoRTANDINsPEcTIoNs P.O.Box14000JUNoBEAcHgFLoRIDA33408St.LucieNuclearPowerPlantUnit2ATTACHMENT BSTRESSESFORS7;LUCIEUNIT2PRESSURIZER LEFMPreparedbyB&WNUCLEARTECHNOLOGIES ForSt.LucieNuclearPowerPlant10MilesSouthofFf.PierceonA1AFt.Pierce,Florida33034NRCDocketNumber:DocumentNumber:RevisionNumber:2Date:Commercial ServiceDate:August8,198350-38932-1235127-02 July14,1995