ML17219A262

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St Lucie I Steam Generator Allowable Tube Wall Degradation.
ML17219A262
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Site: Saint Lucie NextEra Energy icon.png
Issue date: 10/31/1986
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ABB COMBUSTION ENGINEERING NUCLEAR FUEL (FORMERLY
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CENC-1747, NUDOCS 8612150346
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ST.LUCIEISTEAMGENERATORALLOWABLETUBEWALLDEGRADATIONCENC-1747October19868612~503+50003358gg212pgpggQCK05pgRp TABLEOFCONTENTSPAGESUMMARYANDCONCLUSIONSII.INTRODUCTION......III.GEOMETRY.......IV.DEVELOPMENTOFHYDRAULICLOADS~~~~~~~~~~~~~~123A~IntloductlOn~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~B.Loss-of-CoolantAccident1~Thermal-HydraulicModel2.Assumptions.......3.OperatingConditions.........Results............................................C.MainSteamLineBreak5781.Thermal-HydraulicModel............................92.Assumptions........................................93.OperatingConditions.....................~~~t]OV.4.ResultsDEVELOPMENTOFMECHANICALLOADSA.SafeShutdownEarthquake......B.LOCAandMSLBImpulseResponseC.Piessure......~~~~~~~~~~~~~~~~~~~~~~~10~~~~~~~~~11~~~~~~~~~~~~~~~~~~~~~~~~~12VI.ALLOMABLESTRESSDETERMINATIONA.AllowableStressesforTubes...........................13VII.LOCAPLUSSSESTRUCTURALANALYSISA.FiniteElementModelB.LOCAAnalysis....VIII.MSLBPLUSSSESTRUCTURALANALYSISA.Loadings~~~~~~~~~~~~~~~~~~~~~~~~~14~~~~~~~~~~~~~t~~~151.HydraulicFlowLoads...............................172.SSELoads.....~~~~~~~~~~~~~~~~~~~~~~173.PressureLoads.....................................17 PAGEB.FiniteElementModelC.StressResults1.HydraulicFlow2.SSE..3.Pressure..D.ResultantStressesIX.NRCSTAFFCRITERIAFORMINIMUMACCEPTABLETUBEWALLTHICKNESSX.ALLOWABLETUBEWALLDEGRADATION............................XI.REFERENCES1718181819202122APPENDICESA.STRUCTURALGEOMETRYANDFINITEELEMENTMODEL....-....'..A,O8THERMALHYDRAULICMODELANDRESULTS...-B.OC.LOCA+SSESTRUCTURALANALYSISRESULTS...-.............C;0D.RESULTSFROMEPRI/CEPROJECTS144.E.EVALUATIONPERNRCSTAFFCRITERIA..~~~~~~oD~P~~~~~~~E~OF.FATIGUEEVALUATION..............................F.O11

I.SUMMARYANDCONCLUSIONSThisanalysisestablishestheallowabletubewalldegradationfortheSt.LucieIsteamgeneratorbasedontherequirementsofReg.Guide1.121(Reference1).Theanalysisconsidersthetubeloadingsduetonormaloperation,LossofCoolantAccident(LOCA),MainSteamLineBreak(MSLB)andSafeShutdownEarthquake(SSE).AllowabletubewalldegradationisestablishedinaccordancewiththeASMECodeSectionIIIallowables(ormargins)consistentwiththeprovisionsofReg.Guide1.121.Thefollowingsummarizestheresultsofthisanalysis:A.ThecriteriaonnormaloperatingdifferentialpressureofReg.Guide1.121controlstheallowabletubewalldegradationforallregionsofthetubebundlewiththeexceptionoftheupperre-gions(abovetheuppermostsupportplate)ofTubeRows117through120which.aregovernedbyLOCA+SSEloads.B.Theallowabletubewalldegradationis63KforallregionsexceptfortheregionsabovetheuppermostsupportplateforfollowingTubeRows:a)TubeRow117-59%b)TubeRow118-60Kc)TubeRow119-61%d)TubeRow120-62%C.TheallowabletubewalldegradationdeterminedfromconsiderationofNSLBandSSEisaminimumof66Kandisnotcontrolling.

II.INTRODUCTIONTheanalysispresentedhereinisperformedtoestablishthemaximumallowabletubewalldegradationfortheSt.Lucie1SteamGeneratortubespertherequirementsofNRCReg.Guide1.121.Theresultsofthisstudywillbeusedasthebasesforasteamgeneratortechnicalspecificationchangetothetubepluggingcriteria.ThisreportaddressestherequirementsofNRCReg.Guide1.121formaximumallowabledifferentialpressuresduringnormaloperationandaccidentconditionsaswellastheASMECodeSectionIIIAppendixFrequirementsforfaultedloadconditionsofLossofCoolantAccidents(LOCA)plusSafeShutdownEarthquake(SSE)loadsandMainSteamLineBreak(MSLB)plusSSEloads.Duringtheperformanceofthisanalysis,considerationisgiventothetubesupportplatemodificationswhereintheouterrimsandlugsoftheuppertubesupportplateswereremoved.Thisallowstheupperportionofthetubebundletomovelaterallythroughagapandcon-tacttheshroudduringaLOCAevent.Tuberows87through140areevaluatedinthisanalysiswiththeshorterrowsconsideredtobenon-controllingduetodecreasingLOCAforcesresultingfromshorterhorizontalspansanddecreasingmomentarmlengthsbetweenthepointofloadapplicationandthesupportlocations.

III.'GEOMETRYTheSt.LucieIsteamgeneratortubebundleisconstructedfrom0.75inchO.D.X0.048inchwalltubesandissupportedbygridtype(eggcrate)tubesupportsintheaxialflowregion.(SeeFigureA.1.).Thetubebundleisrestrainedinthecross-flowregionbyseveraldifferenttypesoftubesupports.Theverticalstraightlegportionofthetubesisrestrainedbytwopartialeggcratesandtwodrillplates.Thehorizontaltubespaninsidethe90arc10inchradiibendsissupportedbyslottedverticalstripscontaining.horizontalstripsweldedintoalignedslots.Thissupportarrangementprovidesverticalin-planeandout-of-planemotionrestraintandisaninte-gralpartofthediagonalsupportswhichextendacrossthe10inchradiusbendofalltubes.ThissupportassemblyisuniquetotheCEdesignand,duetoitsfirmattachmenttotherestrainingI-beams,providesexcellentlateralaswellasverticalsupporttothetubes.Pastmodificationstothetwodrillplatesupportsconsistedofre-movingtheirouterrimsandpartoftheattachinglugsleavingagapwherebylateralmotioncanoccur.Theplateswere"staked"byexpandingatubesleeveintothetubeattheplatejunctionatninelocationsonthelowerplateandfiveplacesontheupperplate.

IV.DEVELOPMENTOFHYDRAULICLOADSA.IntroductionALoss-of-CoolantAccident(LOCA)producesararefactionwavewhichpropagatesatthespeedofsoundawayfromthebreaklocation.Astherarefactionwavepassesthroughthetubesinthebendregionofthesteamgenerator,itimpartsalateralpressureloadingonthetubebundle.Thepressureloadingonaparticulartubeispropor-tionaltothepressuredifferenceactingbetweenthemidpointsofthebends.Fluidfrictionandthecentrifugalforcesgeneratedasthefluidnegotiatesthebendsalsocontributetothelateralloadingonrthetubebundle.Thenetforceonaparticulartubeisthealgebraicsumofthepressure,friction,andcentrifugalforces.AMainSteamLineBreak(MSLB)producesatransientpressureloadingonsteamgeneratorinternals.Thepressureloadingresultsfromtherelativeratesatwhichthesecondaryfluidleavesadjacentregions.Ingeneral,theblowdownratefollowingamainsteamlinebreakde-pendsuponthesteamgeneratorgeometry,thesecondarypressure,the.secondarymass,andthenozzlearea.Thethermal-hydraulicresponseoftheprimary(LOCA)andsecondary(MSLB)systemsduringthepostulatedaccidentsisanalyzedusingCombustionEngineering'sCEFLASH-4Acomputercode(Reference4).CEFLASH-4Aisaone-dimensional,two-phase,thermal-hydrauliccodewhichcalculatesthetime-dependentbehaviorofthefluidstatere-sultingfromaflowlineruptureoranoperationaltransient.Thesolutionproceedsbynumericallyintegratingthemomentumequationappliedtotheflowpathswhilemaintainingmassandenergybalancesinthenodes.Heattransferbetweentheprimaryandsecondaryfluidsiscalculated.

Thecodecontainsitsownwaterpropertytablesand'numberofuser-selectedoptions.CriticalflowmodelsincludetheMoody,theHenry-Fauske,andthemodifiedHenry-Fauske/Moodycorrelations.Frictionfactorsmaybeuser-specifiedorcode-calculatedtoconformtoinitialconditions.ThefrictionfactorsmaybeconstantorRey-noldsNumberdependentduringthetransient.Availabletwo-phasemultipliersincludethoseofMartinelli-NelsonandThorn.Themomen-tumfluxterm,whichaccountsforthepressuredropresultingfromspatialchangesindensityandvelocity,maybeselectivelyincludedinthemomentumequation.Finally,bothhomogeneous(mixedphase)andheterogeneous(separatedphase)nodesmaybechosen.In1982,anexperimentalprogram,sponsoredinpartbytheElectricPowerResearchInstitute,wascompletedinwhichthehydraulicload-ingpredictedbytheCEFLASH-4AcodewascomparedwithexperimentalmeasurementsforafivetubemodelofasteamgeneratorexperiencingaLOCA.Thisanalytical/experimentalcomparisonprovidedvalidationofthecode'sthermal-hydraulicmodelingandrecommendedthat-forLOCAeventswhichfocusonthesteamgeneratorinternals-thebreakbemodeledasclosetothesteamgeneratorasisphysicallypossible(Reference5).B.Loss-of-CoolantAccident1.Thermal-HdraulicModelIthasbeenestablishedthatmaximumhydraulicloadingonasteamgeneratortubeinthebendregionisrealizedduringadouble-endedguillotinebreakinthecoldlegpipe.Inthepresentanalysis,thebreakismodeledatasteamgeneratorprimaryoutletnozzle(Refer-ence5).Foracoldlegbreak,thehydraulicforcesonasteamgen-eratortubeinthebendregionareillustratedinFigureB.l.The pressureforceresultingfromtherarefactionwaveisdefinedbythepressuredifferencebetweenthemidpointsofthebends(atthe45positions)actingoverthe-cross-sectionalflowareaofthetube.Thetime-varyingaveragefluidfrictionforceisbasedonthemassflowrateinthecenterofthehorizontalspanandisdefinedby:2fWvL'2~0gwhere,fisthefrictionfactor,dimensionlessMistheflowrateinthetube,ibm/secvisthespecificvolume,ft/ibmDisthetubeinsidediameter,ft.Listhelengthbetweenthemidpointsofthebends,ft.gistheuniversalgravitationalconstant,32.17ft-ibm/lb-sec2fTheresultanthorizontalcomponentofthecentrifugalforcesexertedbythefluidinnegotiatingthebendsisneglectedinthepresentanalysis.Ouringaloss-of-coolantaccident,thesecondarysystemremainsin-tactexceptforheattransferbetweentheprimaryandthesecondaryfluids.Thusrepresentationofthesecondarysystems(twosteamgenerators)intheLOCAthermal-hydraulicmodelisremote.However,thefinitespeedofpropagationandmultiplereflectionsoftherare-factionwavewhichtravelsthroughtheprimarysystemrequireanaccurateandcompleterepresentationoftheprimarysystem.Theentireprimaryflowsystemisdividedintoanetworkofnodesand flowpathsasisshowninFiguresB.2.Inaddition,itisnecessarytoprovidemorerefinedmodelingforthesteamgeneratorthatistheclosesttothebreaklocation(FigureB.3).Thethermal-hydraulicdetailshowninFigure8.3pertainstoeachofthreetuberowsmodeled(tuberows8140,114and88).NodeandflowpathnumbersnotincludedinFigures8.2andB.3arenotutilizedintheLOCAthermal-hydraulicmodel.Thefollowingassumptionsareutilized:a.Allnodesarehomogeneous.b.ThepropertiesofwaterandsteamforestablishinginitialandboundaryconditionsaretakenfromReference6;c.Adouble-endedguillotinebreakopeningtimeof0.020secondsisassumedfortheruptureofone30-inchcoldlegpipeatonepri-maryoutletnozzle.Thisbreakopeningtimeisbasedonareac-torcoolantsystemasymmetricloadanalysis(Reference7).d.Thetwo-phasepressuredropiscalculatedbyfirstspecifyingconstantliquidphasefrictionfactorsbasedontheMoodydiagram(Reference8).ThesefrictionfactorsarethenmultipliedbytheThorntwo-phaseflowfactor(Reference9)storedwithinthecode.e.Themomentumfluxtermisincludedforallinternalflowpaths.f.FlowthroughthebreakismodeledusingthemodifiedHenry-Fauske/Moodycriticalflowcorrelation.

g.Adischargecoefficientof0.7isassumed(Reference10).h.Itisassumedthat15%ofthesteamgeneratortubesareplugged.3.0eratinConditionsTheLOCAeventoccursatfullpowerwiththefollowingplantoperatingconditions(Reference11):~Pr1marPrimaryTemperatureIn,FPrimaryTemperatureOut,FPrimaryFlowRate,ibm/sec.PrimaryPressure,.psia598548193672250~SeconderSaturationPressure,psiaFeedwaterTemperature,FFeedwaterFlowRate,ibm/sec.886430.916414.ResultsThenetforceonatubeineachofthethreetuberowsmodeled(tuberows8140,114and88)asafunctionoftimeispresentedinFigures8.4,8.5and8.6,respectively.Itcanbeseenthat,foreachofthesetuberows,themaximumhydraulicloadingisrealizedatapprox-imately0.015seconds.Thenetforceasafunctionoftimeforeachtuberowisinputintothelineardynamictransientanalysis.ThepressureinthemiddleofthebendsasafunctionoftimeforeachtuberowispresentedinFigures8.7through8.12.TheaverageflowrateinFlowPath42asafunctionoftimeforeachtuberowispresentedinFigures8.13through8.15.

C.MainSteamLineBreak1.Thermal-HdraulicModelPreviousanalysesofamainsteamlinebreakforawiderangeofoperatingconditionsanddifferentsteamgeneratorgeometriesindi-catethatpeakpressureloadsonsteamgeneratorinternalsarereal-izedateitherzeroorlowpoweroperation.Peakpressureloadacrossthetubebendregionisrealizedatzeropercentpower.Our-ingthemainsteamlinebreak,therapiddepressurizationofthesecondaryfluidanditsaccelerationtowardthebreaklocationareunaffectedbytheprimarysystem.Therefore,theMSLBthermal-hydraulicmodelfeaturesonlydetailthatpertainstothesecondarysystem,asisshowninFigure8.16.NodeandflowpathnumbersnotincludedinFigureB.16arenotutilizedintheMSLBthermal-hydraulicmodel.Thefollowingassumptionsareutilized:a.Allcalculationsaremadeassumingnoslipbetweenthesteamandthewater.*b.Propertiesofwaterandsteamforestablishinginitialandbound-aryconditionsaretakenfromReference6.c.Adouble-endedguillotinebreakopeningtimeof0.001secondsisassumedfortheruptureofthe34-inchsteamlineatthesteamoutletnozzle.

d.Thetwo-phasepressuredropiscalculatedbyfirstspecifyingconstantliquidphasefrictionfactorsbasedontheMoodydiagramReference8).ThesefrictionfactorsarethenmultipliedbytheThorntwo-phaseflowfactor(Reference9)storedwithinthecode.e.FlowthroughthebreakismodeledusingtheMoodycriticalflowcorrelation(Reference12).f.Themomentumfluxtermisincludedforallinternalflowpaths.g.Adischargecoefficientof1.0isassumed.3.0eratinConditionsTheMSLBeventoccursatzeropowerwiththefollowingplantoperat-ingconditions(Reference11):~SeconderSaturationPressure,psiaFeedwaterTemperature,FFeedwaterFlowRate,ibm/sec.0%Power37509004.ResultsThepressuredifferenceacrossthetubebendregion(P9-P6)asafunctionoftimeispresentedinFigureB.17.Themaximumpressureloadof28.6psiisrealizedatapproximately0.075seconds.ThepressureinNodes9and6asafunctionoftimeispresentedinFig-uressB.18andB.19.TheflowrateinFlowPath7(inthemiddleofthetubebendregion)asafunctionoftimeispresentedinFigureB.20.10

V.DEVELOPMENTOFMECHANICALLOADSA.SafeShutdownEarthuakeTheprojectspecificationforSt.LucieI,Reference3,statesthatthesteamgeneratorassemblyshallbecapableofwithstandingamaxi-mumseismicloadingequivalentto0.5g'sinbothhorizontalandver-ticaldirectionsappliedsimultaneouslythroughthesteamgeneratorsupports.TheevaluationofthisloadingconditionisaccomplishedwithanANSYS(Reference13)two-dimensionalfiniteelementmodelwhichisdescribedinSectionVIIandisutilizedforbothSSEandLOCAevaluations.SSEstressesareobtainedbytheapplicationofastaticloadequivalenttoa+0.5gaccelerationinthehorizontalandverticaldirectionssimultaneously.TwoverticalloadcasesareconsideredsinceSSE+deadweightloadingsareanalyzedtodeterminetheworstcondition.HoweverLOCAstressesarenormallycontrolling,therefore,SSEstresslocationsareevaluatedattheworstLOCAstresslocation.B.LOCAandMSLBImulseResonseTheLOCAorMSLBaccidentproducesanexternallyappliedimpulsetothesteamgeneratorcausedbythefluidescapingfromitsrespectiveloop.LOCAimpulsestresseshavebeencalculatedforaunitofsimi-lardesignandhavebeenfoundtobeonly+2.0ksi.(Reference14).However,duetoremovalofthedrillsupportplates,lugsandouterrim,gapsarepresentwhichallowimpactingbetweenthedrillplatetubeassemblyandthebafflewhichincreasestubebendingstresses.Avalueof+4.0ksiisusedinthisanalysisbasedontheparametricevaluationofagapconditionpresentedinAppendixC.Mainsteamlinebreakimpulseloadingsareconservativelyestimatedat+6.0ksiforuseinthisanalysisbasedonaworstcaselocation11 inthecrossflowregionforaunitofsimilardesignand0.75"0.0.X0.008"walltubes.C.PressureOuringtheLOCAeventatubeissubjectedtoanetpressureforcewhichproducesanaxialforceintheverticalstraightportionofthetube.WiththesecondarypressureremainingapproximatelyconstantduringtheLOCAeventat815psia,a"blow-off"differentialpressurestressisdetermined-basedonthispressureandtheprimarypressureatthetimeofmaximumLOCAstresses.Theprimarypressure,isob-tainedfromthe"CE-FLASH"programresultsandis1336psiaatthetimeandlocationofmaximumtubestress.ThepressuredifferentialforMSLBisconservativelytakentobe2250ps'hisisbasedontheoperatingprimarypressurewiththeas-sumptionthatthesecondarypressurehasdecayedtozero.12 VI.ALLOWABLESTRESSDETERMINATIONThe'basisfortheallowablestressesusedinthisanalysisisSectionIIIoftheASMECodeforNuclearPowerPlantComponents.ValuesforS,yieldstrengthandultimatestrengthatoperatingtemperaturesaretakendirectlyfromtheappropriatetablesintheCode.A.AllowableStressesforTubesTheultimatestrengthfortheSB-163InconeltubingisS=80.0ksi0u,atthemaximumoperatingtemperatureof600F.AppendixFofSectionIIIgivesthemembranestressallowableforthefaultedconditionsconsideredinthisreportas:orSb=0.7SS=56.0ks>ThemembraneplusbendingallowableisSbf.0.7S+bendMherefisafunctionofcross-sectionalshapeaswellastheratioofmembraneandbendingstressestoyieldstress.Aninteractioncurve,FigureE.4isshowninAppendixEfora63percentdegradedtubeandahealthytube.TheratioofmembranetoyieldstressfortheLOCAanalysisisap-proximately0.2~Therefore,fisequalto1.44andtheallowablestressintensityis:S.I.=S+b=1.44(56)=80.6ksi13

VII.LOCAPLUSSSESTRUCTURALANALYSISA.FiniteElementModelAnANSYSfiniteelementmodelisdevelopedforthetubebundlegeome-trydescribedinSectionIII.FigureA.2givesaschematicoftheportionofthetubebundlethatis-modeledforthisanalysis.Themodelisatwo-dimensionalrepresentationofthetubebundledevel-opedbycombiningthetubesinRows87through140into19lumpedparametricrowsasgiveninTableA.l.Themodelincludesthepor-tionofthetubebundleabovetheuppermostfulleggcratesupportwithallthetubesthatarecapturedbythe.lowerdrillplateplusthefirstthreetuberowsthatareinsidethelowerdrillplate.ThefiniteelementmodelisshowninFigureA.3.Thetubesaremodeledastwo-dimensionalbeam,ANSYSStif3,elements.Themassdistribu-tionofthedrillplatesisrepresentedbylumpedmass,ANSYSStif21,elementsatthenodeswhichareatthedrillplatelocations.Theeffectofthedrillplatesismodeledbycouplingthenodesinthe"x"horizontaldirectionatthedrillplatelocations.Thehori-zontalportionofthetubesarecoupledtotheverticalsupportswithonedimensionalspring,ANSYSStif14,elements.Theverticalsup-portandbatwingareasandmomentsofinertiaareweightedforeachrowbasedonthenumberofverticalsupportsandbatwingsinthatrow.Thefiniteelementmodelhas723elementsofthetypeslistedabove.)Themodelboundary"conditionsareasfollows:Thetubesatthefulleggcratearefixedinthe"x"and"Y"direction.Thetubesarefixedinthe"x"directionatthepartialeggcratelocations.The.7inchgapwhichisdescribedinAppendixCismodeledusingtheANSYSgapmoduledescribedinSection3.2.14ofReference13.

TheanalysisisperformedforhealthyInconeltubes-.75inchO.D.X.048inchwallthickness.Thetubeelementsareattributedanequiv-alentdensity,p,formulatedfrom:P=(1/AT)(PTAT+PSAS+CPfAf)wherep=Densityoftubematerial=.305lbs/inp=Density-offluidintube=.0261lbs/inpf=Density-ofdisplacedfluid=.0045lbs/inAT=Areaoftubematerial=.106inAS=Insideareaoftube=.336inAf=Outsideareaoftube=.442inC=VirtualmasscoefficientAvirtualmasscoefficientofCm=1.7isappliedtothetubes.Theresultingdensitybecomes.4157lbs/inandthecorrespondingmassdensityis.001077,lbs-sec/in.Astructuraldampingof2Xofcriti-caldampingisusedforthesmalldiameterpipinginaccordancewithAECRegulatoryGuide1.61.(Reference14).Themodulusofelasticityis28.8X10psiforthetubesand26.3X10psifortheverticalsupportsandbatwings.ThefluiddynamicloadsversustimeforTubeRows140,114and88aregiveninFiguresB.4,B.5,andB.6.ThesecorrespondwithModelRows19,10,and1.Theloadsgivenintheabovefiguresareforasingletubeineachrow.Therefore,theseloadsmustbescaledandcombined15 forthefiniteelementmodel.Thisisdonebyassumingthattheloadsvarylinearlybetweenthethreerowssothatthetotalloadonanymodelrowisthetotaloftheinterpolatedsingletubeloadmul-tipliedbythenumberoflumpedtubesinthatmodelrow.Themodeltuberowloadsareappliedasconcentratedforcesasafunctionoftimeinthehorizontaldirectionactingatthecenternodesoftherespectivehorizontaltubespans.TheanalysisistheANSYSReducedLinearDynamicAnalysis.Theresultsofthisanalysisaretheele-mentstressesandloadsasafunctionof.time.ThemaximumstressinthestresstimehistoryforeachmodeltuberowisshowninTableC.l.Thelocationofthemaximumstressforeachtuberowisindi-catedinFigureC.l.Atimehistoryplotofthemaximumbendingstressformodelrowsllthrough15isgiveninFigureC.2.ThesestressesareatNodes259,284,309,334and359ofelements184,183,185,187and189,respectivelyasshowninFigureC.3.FigureC.4givesapl'otofthedisplacedgeometryatthetimeofthemaximumLOCAstresses.FigureC.5givesatimehistoryplotofthedis-placementsofNodes19,469and259.ThelocationofNodes19and469areshowninFigureC.1,whileNode259isgiveninFigureC.3.FigureC.6givesatimehistoryplotofthedisplacementsofNodes457and459.ThelocationofNode959isgiveninFigureC.l,while459isshowninFigureC.3..TheSSEseismicloadingisevaluatedusingthesamemodelasfortheLOCAanalysis.TheSSEloadsareappliedasaccelerationsof-1.5Gverticallyand+.5Ghorizontally.TheresultingSSEstressesatthelocationsofmaximumLOCAstressarealsoshowninTableC.l.16 VIII.MSLBPLUS-SSESTRUCTURALANALYSISA.~Loadina1.HdraulicFlowLoadsThetubesinthecross-flowregionaresubjectedtoanexternalflowinducedpressuredropduringtheMSLBevent.DetailsoftheanalysisprocedureandresultsarepresentedinSectionIVandAppendix8,respectively.Themaximumpressuredropacrossthebendregionofthetubebundleis28.6psi.ThispressureloadisfromFigureB.17andisappliedasaconstantloadingwhichisconservative.Theloadingimposedonthehorizontalspanofeachtubeisbasedontheassumptionthattheforceactingisproportionaltotheratioofanindividualtubeprojectedareatothetotalcross-flowtubeareaofthebundle.2.'SELoadsAsdefinedinSectionV.A,0.5gloadswereappliedsimultaneouslyinthehorizontalandverticaldirectionswithdeadweightloadsconsid-eredintheverticaldirection.3.PressureLoadsThetubedifferentialpressureisassumedtobe2250psiandisbasedontheassumptionthatthesecondarypressurehasdecayedtozero.B.FiniteElementModelTheFEMisdescribedinSectionVIIwithdetailedgeometryplotspresentedinAppendixA.Briefly,themodelisplanarwithRows87through140modeledin19lumpedparameterrows.Mostofthemodel17 rowshave-threeactualtuberowswithcombinedmass,stiffness,andloadings.Selectionofverticalstripareasandmomentofinertiasareweightedsothatthedynamiccharacteristicsofthetubebundlearenotaltered.C.StressResultsThemaximumbendingstressesduetoMSLBflowloadsare9.77and9.95ksiatnodelocations212and217,respectively.ThiscorrespondstoTubeRows110,111and112whicharetheshortestrowsattachedtoallthreeverticalstrips(seeFigureA.2).Node217islocatedattheleftverticalstrip/tubepositionwhile212isinthe90degreebendregion.2.SSETheseismicstressesatNodes212and217occurringatthetimeofmaximumNSLBstressesare7.6'and6.3ksi,respectively.Thevalueof7.6ksiisalsothehighestSSEstressforanylocationinthebundle.TabulatedvaluesareincludedinTableC.lforallmodeltuberows.3.PressureThestressesduetoadifferentialpressureof2250psiintheaxial,hoop,andradialdirectionsare:i=7.7ksiPR.2t18 PR.~hoop=i=15.3ksitoradial=P=02D.ResultantStressesTheresultantstressintensityisdeterminedbycombiningNSLBandSSEstressesusingthesquarerootofthesumofthesquares(SRSS)methodplustheadditionofpressurestresses.01[(9.77)+(7.6)]=12.4ksi8Node212<2=[(9.95)+(6.3)]=11.8ksi8Node217Theworstcasestress,a1,isusedtodetermineamaximumallowableTWDof66percent.Theprocedurefordeterminingthisvalueispre-sentedinArticleE.lofAppendixE.1oaxialradial=12.4+7.7-0=20.1<1.44(.7)Su=80.6ksi19 IX.NRCSTAFF.CRITERIAFORMINIMUMACCEPTABLETUBEWALLTHICKNESS1.Tubeswithdetectedacceptabledefectswillnotbestresseddur-ingthefullrangeofnormalreactoroperationbeyondtheelasticrangeoftubematerial.2.Thefactorofsafetyagainstfailurebyburstingundernormaloperatingconditionsisnotlessthanthreeatanytubelocationwheredefectshavebeendetected.3.Crack-typedefects,thatcouldleadtotuberuptureeitherduringnormaloperationorunderpostulatedaccidentconditionswouldnotbeacceptable.ThesecriteriaarefromReference1andareinadditiontothefault-edallowablesofSectionIII.FigureE.lpresentstheminimumre-quiredthicknessesfortubesbasedontheabovecriteria.'20

X.ALLOWABLETUBEWALLDEGRADATIONAstructural-thermalhydraulicanalysisoftheSt.Lucie1SteamGeneratortubebundleindicatesthattheallowableTWDiscontrolled,foramajorityoftuberowsbyNRCReg.Guide1.121criteria.AmaximumallowableTWDof63percentisfoundtobeacceptableforalltuberowswiththeexceptionsof117through120abovethetopdrillplate.ThemaximumallowableTWDfortheserowsiscontrolledbythefaultedcondition,LOCA+SSE,andis59,60,61,and62percent,respectively.TheprocedureforfaultedloadsevaluationispresentedinAppendixE.AtabulationofLOCAandSSEstressesisgiveninTableC.lofAppendixC.Itshouldbenotedthat97.9percentofalltubesmeettherequirementsofReg.Guide1.121for63percentTWDwithonly178tubesor2.1percenthavingallowableTMD'sof59-62percent.AfatigueanalysisofadegradedtubeispresentedinAppendixFwiththemaximumusagefactor,U,fora63percentdegradedtubedeter-mined*tobezero.'21 XI.REFERENCES1.NuclearRegulatoryGuide1.121,"BasesforPluggingDegradedPHRSteamGeneratorTubes".2.ASMEBoilerandPressureVesselCode,SectionIIIforNuclearVessels,1986Edition.3.EngineeringSpecificationforSteamGeneratorAssembliesforSaintLucieNo.1,SpecificationNo.19367-31-2,Revision13.4."CEFLASH-4A,AFortranIVDigitalComputerProgramforReactorBlowdownAnalysis",SA-78-223,J.M.Betancourt,CombustionEngi-neering,Inc.,Department489,June1973.5.EPRINP-2652,"LoadsonSteamGeneratorTubesduringSimulatedLoss-of-CoolantAccidentConditions",ProjectS144-1,FinalRe-port,November1982.6.1977ASMESteamTables,C.A.Meyer,etal.,ThirdEdition,ASME,NewYork,N.Y.,1977.7."ReactorCoolantSystemsAsymmetricLoadEvaluationProgram-FinalReportforCalvertCliffs1and2,Millstone2,PalisadesandFortCalhoun",June30,1980.8.Moody,L.F.,"FrictionFactorsforPipeFlow",Transactions,ASME,Vol.66,1944.9.Thorn,J.R.S.,"PredictionofPressureDropDuringForcedCircu-lationBoilingofMater",Int.J.Heat&MassTransfer,Vol.7,1964.22 10.CombustionEngineeringReportCENPD-252-P-A,"BlowdownAnalysisMethod",July1979.11.FloridaPower5LightCompany,JNS-MCI-86-161,LetterfromJ.E.NoabatoJ.N.Mesthoven,October3,1986.12.Moody,F.J.,"MaximumFlowRateofaSingleComponent,Two-PhaseMixture",ASMETransactions,February1965.13.ANSYSEngineeringAnalysisSystem,FiniteElementComputerPro-gram,Revision4;1,March1,1983,JohnA.Swanson,Ph.D.14.AECRegulatoryGuide1.61..15.CombustionEngineering,Inc.,CENC-1264(Revision2),"AnalysistoDetermineAllowableTubeMallDegradationforPalisadesSteamGenerators",March30,1976.16.CombustionEngineering,Inc.,CENC-1170,"AnalyticalReportforFloridaPower5LightCompanySteamGenerator",December,1971.17.DesininbPhotoelasticit,R.B.Heywood,1952.23 APPENDIXASTRUCTURALGEOMETRYANDFINITEELEMENTMODELFIGUREA.1STEAMGENERATORELEVATIONVIEWFIGUREA.2UPPERTUBEBUNDLEGEOMETRYFIGUREA.3ANSYSFINITEELEMENTMODELTABLEA.1FINITEELEMENTMODELTUBEDATAA.O JQhQj,FIGUREA.1STEAMGENERATOR-ELEVATIONVIEWA.l

BAFFLE.BATWING317510"RADIUS(TYPICAL)ROW14022DRILLPLATETYPICALSLOTS-ROW116ROI1110-tOW9022DRILLPLATEROW66P.EC26.5P.E.C.ROW56OW2825.5TOPFULLEGGCRAITESUPPORTFIGUREA.2UPPERTUBEBUNDLEGEOMETRYA.2 TABLEA.lFINITEELEMENTMODELTUBEDATAMODELROWTUBEROWSROWNO.TOTALNO.OFTUBESMOMENTSOFINERTIA(IN)AREA(IN)687888990919293949596979899100101102103104666564636460~6261626160596059585756571951871851801771701.27731.22491.21181.17901.15941.113520.6719.82219.6119.0818.76218.0210556106.10754165..1.080817.4910108109110ill112113114115116535251505150494847105152194.6878.99561.270711.1316.11220.564A.4 MODELROMROWNO.TUBEROWSTOTALNO.OFTUBESMOMENTSOFINERTIA(IN)AREA(IN)1213141516171819117118119120121122123124125126127128129130131132133134135136137138139140464544434241403938373635343330292827282920171291129120102877449~--=-~9.5960.8450.7860.7271.6681.5699.4847.3210.058959.64613.67412.7211.76610.8129.2227.8445.194.954A.5 APPENDIXBTHERMAL-HYDRAULICMODELSANDRESULTSFIGUREB.1HYDRAULICFORCESONATUBEFIGUREB.2LOCATHERMAL-HYDRAULICMODELFIGUREB.3FIGUREB.4FIGUREB.5LOCATHECAL-HYDRAULICMODEL(STEAMGENERATORDETAIL)CLOCANETFORCEVSTIME(TUBEROW8140)LOCANETFORCEVSTIME(TUBEROW8114)FIGUREB.6LOCANETFORCEVSTIVE(TUBEROW888)FIGUREB.7AVERAGEPRESSUREBETWEENNODES39AND40VSTIME(TUBEROlllj140)FIGUREB.8AVERAGEPRESSUREBETWEENNODES44AND45VS.TDK(TUBEROM8140)FIGUREB.9AVERAGEPRESSUREBETtJEENNODES39AND40VSTIVE(TUBEROW8114)FIGUREB.10AVERAGEPRESSUREBETWEENNODES44AND45VS.TIME(TUBEROWf114)FIGUREB.11AVERAGEPRESSUREBETWEENNODES39AND40VSTIME(TUBEROWII88)FIGUREB.12AVERAGEPRESSUREBETWEENNODES44AND45VSTIME(TUBEROWPP88)B.O

APPENDIXB-(CONTINUED)THERMAL-HYDRAULICYODELSANDRESULTSFIGUREB.13FLOWRATEINFLOtlPATH42VSTIME(TUBERONt'!140)FIGUREB.14FLOWRATEINFLOWPATH42VSTIYE(TUBEROW//114)FIGUREB.15FLONRATEINFLOWPATH42VSTIME(TUBEROWf88)FIGUREB.16Y~LBTHERYAL-HYDRAULICYODELFIGUREB.17PRESSUREDIFFERENCEVSTIME(Pg-P6)FIGUREB.18PRESSUREINNODE9VSTIYEFIGUREB.19PRESSUREINNODE6VSTIYENFIGUREB.20FLOWRATEINFLOt'/PATH7VSTIYE FIGUREB.1HYDRAULICFORCESONATUBEHorizontaFNt=F<<Ff(F-F)epcx1cx2'NeF=hP~APFfncx1BreakLocationB.2 FIGU8.2LOCATHERMAL-HYDRAULICMODEL21222023251917D35Secondary)2D34Secondaryf11261627301533-3433ll12131ll910131215353131262930S.1.TankflS.1.Tankf2S.1.Tankl3FillSystoa5636NHode323229FlerPath 1

FIGUREB.3,LOCATHERMAL-HYDRAULICMODELSTEAMGENERATORDETAIL)PrimarySystem41l24344404142l3453946462547472119184949162417142629B.4

f~,ImIIh,"FIGUREB..TubeRo,'LOCANETFORCEf.~II~I4VSTIMEhIi140I!I80206050i.540O3020llm~WII;'i.!Iflt~Imatm~JW~AI'~=-I~~m~~~mm~W~~j'fI"='-llII~~It,~m--I~~ltIlmIIII~ImIIIIltiWI~Wl!I~IIIltNIII~~m~10II-10I~I-20h0,I~m,IIIIhh[I':"1ijjm~!(IIlltI'082,.0P4)l006!,0;~III~=*[hI,'I;'I0!10,01I120.]40.160.180Time,SecondsI~/mj'I="I'~'mjt!fjj;jt'ljj~Img'tm"I,):I!jlPW,(,mii'!Ž!'IIImI~ml'f,hm IL.~II":~~I>>FIGURE8.5}LOCANETFORCE,VSTINEIIh'>>*[807060~=~(~=h:It~I~~'\m~>>III~',4Il(I>>'}I:.I,~I~ITube'ow8114I~III'11't~>>~~~II'f,I>>~>>~l~I~*,~h->>Itl,h't(~>>t~I'I,lJ5Ig7>>~(I)OSO~~I(IJI50403Q>>II~I>>1-20~:,.',I10h~~ItmIIItt-10I',}-20iI0.020.040.06O.h8(0.I~~110-"0.;(ii}'i}'(0.14,'0.16-.'0;8IO..Time,-SecandgIh~hl(I~~Ii(t)(~-'I}II),;;tI~lhI~I III~8070I~I'IIsII.~Ii~sIII'f~II*I'srjIIIs;IsIf1'TubeRow'888---iI;,I.-tI'FIGURE8.6IOCANETFORCEVSLIME*I~I'~~.I.I...I.:I~;'iI':iiii..':::i"II.al~ratIIIIII+~t+L1sI=~~~~t~=*~IsIII~.It~',l'.t~I~~~IIIIIf~I~I~I6050';~l,lIIIIIIII~.I'IW~~o!II~iQJt40302010II,II~.iI;ttIIII'tI.sIIilI'sIIsII~I~I}IIIiIl.IIIi=.~I~I!Il-10I-20~~"0.020.04'";0.06,*I'0'~~~it~iltl.I~:s'sl30.al~~aIii.:IT.mmeJSecondst12""014'j,0f16i-01,0~~IlIII'IIt~18-s~20~~II.'l.-.!',ll!1iili'.!Ijr'.issjs

(.'~~n(Lli()))1800r117001600.lI1500~II')).I.,--'-!14001I'1300.>>i.,2200I....I..2100I'20001.,I;1900nI<<I~~'I';~I<<-~li~>>>>I'1ln)!,I<<I~~~~I~I~.~~>>'sr~~rn'<<iIi.~n~~s:sslI~~'r>>iI<<IlIs<<~lYls'1Il~.nAG<<I,<<')~>>I>>~~~1'I;,1;n\i~.I>>l,,I<<II',I(Isn;i));~(I'I>>n~If1nlr'VERIl'if.'1~ill))>>sil;isfn~~r'>>II=I'T:"11s,PRESSn>>r~nn~1Il1'IIlllewjI:!~l:sliIsIsIInss~~I1)>>i~~f(Ilr~>>snssIFIGUREB.7.,UREBETWEEN:NODES39ANTubeRod~~<<swn!;i',~~islln>>s~>>~r(<<n~-II1r(>>I'1~n(~Isir~'~<<'i~rl1I.~~II,'(~ll1>>,n'I40VsInI~TIME<<n~~I~1".;I~s)'Isii~~fIs1!i>>I',"'...+I.l..~.;1Is(s',.I'IlsIin)>>1~~nr>>n1.!1IIlnr!jill>>~>>r1InI!I;.~'-,lI-r1':I'Y~I~I~>>II~(I:I.iIIsTr~~Irnll>>II~!l1!nrl1~~I,.n<<IIIre,1.!III~I~>>il'<<.I~~n~>>~.I,(I>>~>>r!iI,-'i(IInIsnl1.jI,:I'I!i~(f~~1~Inn'i":..I..nn,:.1Inln~~li'1)1'I~sl".,Ir~~II),'1I>>!in,'-n!r1I1Inst~rn<<~~r'r>>~~~.'1,.I~=.;I..1~II.0.020;0410.06'.sOo!'0.IIl~~s!-:in~10i0In)((me.!(I1>>iCOlldS,s1r1~(n1I'120.14';160.'18;0.InI20;II~'T>>I~"n<<1s:I':>>~Iis"i<<<<t~n>>I>>sl!<<'

s~s~s,~~tC~t~i~I'1.t.'),Ii.;AVERAG~'isiFIGUREB.:8IUREBETWEEN'NODES~~I!!?~I~~I~~~~~~~III~~!1~!4t44AND45rsil;;s~VTIME~IJTis.stst~~,if,lsI'I~sts~tst'Ii~~Iss'I....I~II22002100I1900.I"1800~~Igl~CLQstgCl.IglIggl~{j)O1700.1600I'500i1400~.,~~2000{sIt~~iIitsIsssI'ts)Is~sJ't~~tIsiII~s~~~gsitte]sIggt{~{s~I'I':i:Ig.'II!IIIll~,Il~sit-~itI~~I?II~.I""=~Isist{Ilst~II",?~"'sgi,'lIIiill<<i<<iI".l!I~I~-gs;IlIIi!:!sgs'lsIL'Isfg,I;I.;I"Ia-.il<<J~+I~.t~lg'g>>I,s,II.it.l:IIJstI~IIs~t~t~I.~~tJ?-Js.IsgsstJlIsItsIts~~I~s.st~tJITub'eRow8140sstsst~sggsP~s~I~asiiIs~~s~IsIIsss~gtt~I{g,jt"ilI!~s~tsIsIsI'.',I,t"J~II~~~s~,,I-~sskit~IliltI',Ii'ltglsss1gI,~.I'~"sli'.il't'Igi,'-I'sI';fig<<s'IIIIII.-jl;'I'll',ill::;I:?Itstt,i~t'l':.sIslsi1300'I~I'.";I~~~ss"II'rt"s~I~.IIsi.-~~I~II'~~Js~ti,I~sIIIIs(sts.~I~~-lII~sI~~I's'lg8~0.1Isr",~iisjil~'liiti;0.020.040.060.000.120.140.160.18'.20:JI;I'I'ime.Sei';on<<-'~~ItI'IrIIII!sl~Iss'!I(!rss~IiillssI!'ll kJ 2200210020001900gl16001600<<~I'II~14001800~I~1700j'-efOg.4!1~~~I~ei.fi!~,~~1"II"I~~II~I4~iIced'.I1'I;,-'II'I~~~rf.lcI.!!Ge,eII<<4ijl",'~~I~"'I'fcjF4'll;4I'4!!IlIil,!leIc"~~4'ii!li~'Iili,I~'I'Ilie~III,:,Ii1.IIII~~~4~vEkn~~~I'Iiil~1'IIIII1~~Ill~~I)II,'-I~I!,4'.II'~1-II.IjclclIIII~~~II!IIIi;,IfPRES4'IGURk8;9UREBETMEEN'ODES39ANITubeRow'If!114~~~Ililt!II~IIII~~11I~Ii!'4'cl~~44clII'IIIItIi'el<<!II.ll4I40V.I'TiNE~~~~1I~~~4I.':I:'elI:fl~I~;I'W,'l~~~~eirlI'~'I4I~1-IIIIiil!llI!II!,IilII~III~I,114,lLlCl'I41~1~I~II*.I~I~\~,I~~II1'ji~'iI~1','llei..-Ice,,I*I*1I"4~~~l4I~4e.I~II'~~~~I~I~IIIlI'.IF.Iei~ii1'r.;il'II~I~~III*'l~I11'"I~'I'.Illci~Iie"II~II,l,eIce~i}I~I~IIII,'leIII,~I-ee'4~4I'I4~'IIIII,II~1i"~4~'~fi~ec1300II0.020.04,0.060.I~1~I~life"1~~80.iI.I~~~I~l.if'tI~I0IO;1el1II'4i~!~!l.160.12.0.14'0Ije.;...Time4I.-:econdI,I~8;0.'I1~Iei~4II1!'.,:Iil~~II,4IIIII'1'!Ic<<,4Ile'IiIcI,"I~1te4IIIIIlI

~~~~~~2200II,es'tI~eI'-!I.,~'.lee~Is'i!;I~~~IsAGVERI~'ITubeRowfj114I(!FIGUREIB.10.PRESSUREBETllEEN'ODES44ANbsI45VfTIflEsI~IleI~,~I;;.s~I,eI.IIe.'.Isrs~I.~ee~~~'"*eeIeI"i.:I"!:sl~~s..l.!.e;s.I:-210020001800ICL~~seIC!IllC!i017001600Is('-150s140I~*130s1900s!II~sset's'.IIItI1IIIIIs'fes}IsI!~',I'llsts.sse~Isc~sssesji'~tseI':III-~I'!'~:le~li'~I~ei.',I:~eseelrI~sf~...!r!;;sjf)j:.i.'i!I',I~~~;".',il.:ei!I}*i,lit,'ll.i.,~lj(se~~se,'sflit,,Ie!,Iee!!lf,hl!i'-iIrstI'e-tei'Ii'I~T,:.Il."I:~use~f;;II~~~s~II~sf~~eI"IhlIelII~IIeII~i~I.I'(,:(,II~lretteess'ffIse-ssIf~.I~.~~~'r~~e~iced~II~~IfI'II':.s':";I'.-';-'ee~~~t,Il;,(if'!III.eII'IeseIIsf~III!e~~'e'~~-II~~IsfisIst~lIii'I',ier,ii'IIe~~~ssl!i;'sl-!-ilI,~s.'1slf~e~s'~,j1".is"I.I~Ise~I~l!'l'.iII,'"'.Istl;Il(r,lIIIIIefIeI'~!Is!!I;I;eij.;lsf~e't~~eIees~I*es~IIIelie~It"'i.I.'I'!..sII~~es~~~~*,esI~~::-,i~~eI~t~teteeeel.~~tIs'fI~I'eslf'!!'eI~sf,ssIeIe,.'iiI:s'j~,li--Is(:"'I:-ets.t0.020.040.060.08.'0.100.120.1'40.160.I'8"0.20esI~Ist!i'Ies!'IIIii;:;:I-sl~~((tsj!,}~sI~u!Ij-.~~I'~I~itfi"IISeeori'~!Tsyj.:IsjIf'eI'ee<<~Ie~Ifl/II!Ill!Ilj'j.

~lt~iIIIIIt4VE'PRESURE'FIGURE8;11BETNEENNODES139'NllAOTheTIHEIIEIVICLCU~4QJMEI/IUlI33EO17001600=15001402200I2100I2000I1900-11300tIlI-Il4~tl4IT~I~~,IIm~I~1*tt~~4E~/44~tl~"~~,1'I"';":.I).4~,Ig44t'.IIII'ubeRowP88IIiII4~4f~t~-~I~hlI~I)t)t444I~*Itl1IT'~Ih~I-I4130jlvIII~I4~Il~~I0.020.040.060.080.1'00.120.140.160.180.2044I~=thllileecon~~'il~j,TT~II~'hIIlE!Wh:jtii~

~Iill'~I>>'II"2200I;.*;~I210020001900IOIIhC7CL~>>illSCJO1800III1700I}.j160I150II140~~>>~I~\'b*I.'li'.'IlII~Il>>II!'IIiI~~iI;I;Iiitlii:lliII~rij'lil>>'~II.ItliltI:i'};I,iI,I'.It,I}"'Ir>>I'I~.~I~~~'II~'.ASPERA.'Ill'I.'~PRESSURE'1'll'ttIb;iiill~>>II'-i!IIIIjfjtIliI1'tII;tllIII!i:IiI::IiilIb'.;.:I.;~I:-'.,:.'1l:~1j'i-,FIGUREB.12:"I',':BETLIEENNODES44.AND45VS~ba'ssl.TubeRow~kvtII}!:I~'I'.I.'Ij"~Ir~1i'.~~*~t~~IIII'biIIIibI~t~I1I~~~IIbk~li~~II~'II>>~IIIII*IITII}ti'~~l~II-~*ITIMEII"',I,~I~~~~~I1III~tII~III:IIt;I.lI~,~~I,~I~I~~'i:,ljl.;,klbI>>vIill:',,}I~1~tI~IIIk~Ii;II<<ll~~Ilt~=I'I!I:tIjI;I>>.llrIb'Il~~ii'"I~~II1I<<'i:"'.IrI>>~,I~I.IIIII'.'riIl'llb~IIII'~I~~b~ll-.I,.'j~II~-Ib~~~I~I}:,::~i>>b~*~~~~~~klbI}b'I.130I~II~I~~I}~iI>>IIIiII}l~"i"~,.I~".I>>~II'l',Jl}~I>>!l':~iI'.lII'IiI~I.I'~~'"':iv'blI0.020.040.060.0o'.1I>>~~0.140.160.18'"0.20*1t~tII'.I:i>>I~~'-"I'l.I~!}"II~b~~tivl~I'I~vlII~I~;i",]lime,.SecoriI~Isj!I~,t'aiI}I>>Ilt~>>Iif~libl)iII,>>II~~1'1~-.

~~~II~I)WIitsI~tI~~s~~~-,~IIsliI~~~'l\Ilgt!I\'ItlliII~Illi'I~IittlIlailIiii'I',llilJlii~sliig,i~~I'ts't~I'~IIIIlI.:;ltieslI~:I.'ll),'llr'FLOWiFIAuRERATEINFLOltB;13,i'ATt):42'Sl,'Jlis"itlIllt'TubeRow8140~IITIl1EII;ItllII::~:;ti:l:~s,~I',~~.;~Igt~I~I--~ttl*ttiIIt1t*'I!lii]f~~~sI~~IJ.'stiII:1I'I~~~ttIt,~~at~~IIillt;I)~Ia-t~I'lt~~~~t'IItil>>JltlI~I~~Ijh'tts~ii!'IIJft.,/lil~I'sIi.IIII~~~t~tllrt=':I~~~I~~I~I-0'.~QII/IEaIgijIOU40000I30000~JsIlii'"sI\I~lisIIII-.IIIItI~II~I'I"~IJ~'ltI~I~~~l~~-.II~t~rIIi~~Ig~Iisf,!t~~~lI.~'g~~~tIil)I*'I~llist)20000~~~J~I~,0.020.040.060.040.1II*I'IIisliiiilI~jŽ-"0I~IIIt0.140.160.10b.20~tsIJI\'.'I~~l~~~"~tt~I.'lI~~~l~tlmej:tec,~IT.Iiltillll"~~

E0, rmIa~'~~*ai:tIii~~aI~i~'I~Ii'lait~~r:laIi~~aaIt:i.FIGUREB.l4FLOW'ATEIf)FLO>fPATHTubeRow8i114mII'I;I\tI.'~iiir~il~,jIi~tt~~42VSI~ITIMEi..iIil'I.'i!tIII~1~'t~III',r~f':itl.,~aI'alma"iIJii'11~Iti)Itl~a~~a.I~I~~tiI0~i,I'ImaI~~~I='at;~f~I'llI~Ia~~~I,Ifii~IIII~,~'!IDQtC/l~~E~Cl'~JOltttlitCC0Lt-~I'al-t.-'..i-,1~IIII60000Il)30000'0000!aIaII1IIIIilI0I1,UI1~~[,liat01:I!'it~~tIIII.,'ail1mfIail..'t-I..II~IiI~',t!t~~~I~II'IiJii',1I~'!-.IaiIIil'III.Uit~,iiI'f~m0al-0~f~If00.020.040.060.08D.IDII~)':im=~-II1iI~0.121~III~I00i~0.140.160.180.20'1~Iilat~~1~~m~IIII~~I~iIITime',Si'":cohdsIaim.t;I~t~I~I'!I1fIf'~IUi:iii~It~ttf~liitl

~-~~~LISIe.II~~r~OIIIV)f:-CZ)CZIs)J+0r5e40000~'II'"II~~~~"'e,I,'I~.I.-:.tI'I...sIeIIe'll+seI~e,Ii;~I'i~jI~~e"IIe~~~II"II;,I'eIlt)'IteIlr~"Sl~ee~~Ielr~~~IlljiiIs~Is~!II-ell~~ee~st'I'eI~I~resI~~IIe~~lis~eIt'1stI".'eIs.jji"I~~LOTubeRow888ieIe-~seIet'FIGURE8.15IRATEiHFLOMRATHi42'VS-~I~ITINEII>I.IjII~e.I.II~~I'~eli~~if>rete~\II'ilIsII~II"',te~eeeSIII'~'.I:'.',I~st'lessst~Isi~I;-~I~t'I'e'e>~I,'II~ete,IlIt~II~"~eI,-~IseII~Iil',1ele)I~.!j,\.1eiI'.jieit~1eeeI,,~e'~I.j~:rl'isliijI(}s~Ie'~I~I1~efs1I~I~I~Ie~030000200000.020.0ItII:.eIIeeII'ttII:I~j~I40.060.080.1ee;e.jllItI~eI~Ie'.:j;III~I','i'-;I";IIIIII~~elet!.'l.teI:I=e~I~I0:0.120.140.160.10-0.20.II~el~I">~II~,e~I~~I'ef'fe~~;I>>I,'ee~~e,r~+,Ief'eII~I~j:tsjlj's,.I.II~~I;a<!I~e.jime,Il'condsi.;Iee~I~Il,!,1st~~teller~I~~~ele'j~Ilj!IIj!'lj.

FIGUREB.16MSLBTHERMAL-HYDRAULICMODELSecondarySystem11IFloePath2424232019191010111213lSB.17

~II~~III4~....j.'."HSLB~4--LBENt)IFIGUREB.r17EGIONPRESSUREDIIIIFEREN~III.-I,E9S~-I~IiIJI4..(..4~I',.jiI4iiI'I~I~4I4IfI"~~'4~~IfrilJII'IllI'*/I'ltI"44IIsfII~ji;"l~ICJOOCQ~$~Q400~IID302520I~*'It~Ii~siilI,i~4~,~~I~~"~44II'IIISr'ii,,I'II~I'IIsl,'I.~~~I~I~II~j-IlltClS-CJS-CL15I10I~5'll'444-10'4I,~O.!20.IIIIf,hlff,tillji"IITjme,reconI4I~!4Ii,llIl~I'i~i'its,4I L14~ee~~~~V~1~1~1~111eIct51~CLlO~IAIll920900QQO860840i~~I~1iII~~1~"!e+Ie~~ilail'ljij)>j~III11~~~1!~ee~'lfit~~;.i!II)j~~',!~ii'Ijl1III1(!'e1e1*~!je.jieelilieie~I'*~~I:i':"'-i"FIGUREB.18,I11PRESSUREINNODE9ItS~*I~'.i!11'1.'!i-~I1lfiljI:11~~~1I,'1TIj1E1~1~~1'ee'Ie:I!~I~If~1"1'~=~11Ie'eI~e~~*i,i:I1t'~'e~i~1j~j.i11~j'I'll~,~'~l1'i~,~~j:1.-l.~1~~IIi1,pieeIlf,1li)1~II'eIji,jji'IIlII~~~I~1'=I~~~1~ilef1lI'I,'~~~'1')1--:I-~1lIel:.e'11:eiejIt~820800I14eee11~.I-"iI'~~~I~11~e~1~i'I1'1ge'i,i;~~~~11.~eei.'111.ijij"I~jI'feejele7801~.l.I;jI,)"jl.l'.2~0.1~1~eII~~tii~i~lIIII~~jj",,*I~'jI1~~11~0.6~~11I1I!I0.8ime',.econ'dI~ItII~'!j1~...I,~11~l111~II,eelI1!l~,!jjjjili.~1Ii~4~1eI1'ej1<<lI~ll~~el~ifeil~~IjI1II I~III~~~I1IiCUgMOgS-Icj6CL--920.900-.8808684}-82I'l."80-78II1II~I~I~I~~1I1,';II*~I~rIf~,.*:I1'I~I,'iIIItI(~-}~ip;.}.'-,IlTTII;'liIII~(II~',PR1IIIII:.ipIiI~!I11)ii'}II~~~~ijII.!IJII~'.1,~~~I~~lar1t!FIGURE0.19ESSUREINRODE(!6VSTINEI~1-I~~I~~I~~I1~*II~*I~~~~I~I~'I,la~!II.~~i".II}':,I~VIIV~~I~I1I~~,'!ii~=I~~Iaal~I~~I~I'avi}"IIltI'I'I~I'III~}~~fIIL;e'I~-I1~'III~VI'I'IllIII~la~~II.I"I(",I,ltI~Il(~I,,I~I~1111~~II,I*llj}.'I}IIIaaI~Iji'II~'I!I!I,IIla~IafI~~I~~~~I~~~I:!3,$!I~!I'II~II~II11I,~I~IItI~ii-}/vaaIIII1~I~IIIVt1'Iii}a~Iliaa-~'II~~~aa!IIII'I0.24:lj0.60.8}'.'0~~~It~II1~ii.'vaa'I~

0000070000~'46000050000CQ~rt444CX3000020000~4110000I"'4'10='=I~44II!40000oE4I'II4III~i:~444I4'I444~\~~~44~s*~IIII~4~",!!';[tI-:(ii4Is.II~~I~4.I:IIi41~IsiIT~I~Iil44!4I44~4II~-I4-lti;4~4"~.4lt44~IFLOWI4I~I~IS44IJT*I4~~~41=I4~,")~II~I*4~'i\~Ii!'4il4~~4444<<4494I4I~I=4I;4>>4li'f.14li.4~~I~'II'ilI4I4II~~II,';;>>Ii't'441IlIIII~}IIiilaI~~~4IFIGUREB.20RATEIttFLOWPATH7VSTItlE!4~4>>~I1'.i44li144~tll4I'";,~tt4~~I~~~I4Ilt~Iilsi~ITII.s'~~4rt~,III,Ii"",I'>>II4Ij444[!IIIit~4~I4.4IsI!lii:,','4~I~I,)1'r4']~4IIh1'"44~~~~It4'4~I44,;"jH~*4'.4i~4I~4l~~II4>>,I~4I.II,.s.11IIstI~~4..It~I4~'I4l>>';.*)IiillI14~~~ill.i:."-is~is'II'lls!ItI4~I,~*I'~Isl44~~+I4~~0.2'.4rr~I4~4\~I1hi.i.>>I,'si~iI,il4ill!IsI'-I~:0.Ij:~stItl4440.84Sego'ri*I,"Time;4,"II]..~~1I!,~IsI~J~itiI~II4~4~*I~l4l:,sl~~4~~~4I444~~~ APPENDIXCRESULTSOFLOCAANDMSLBSTRUCTURALANALYSISARTICLEC.lDISCUSSIONOFTUBESTRESSASAFUNCTIONOFGAPWIDTHTABLEC.lLOCAANDSSESEISMICSTRESSESFIGUREC.1LOCAMAXIMUM-STRESSLOCATIONSFIGUREC.2TIMEHISTORYOFLOCABENDINGSTRESS;NODES259,309,3345350FIGUREC.3GEOMETRYATMAXIMUMSTRESSLOCATIONFIGUREC.4LOCADISPLACEDGEOMETRYFIGUREC.5TIMEHISTORYDISPLACEMENTS;NODES19,2575469FIGUREC.6TIMEHISTORYDISPLACEMENTS;NODES4595759FIGUREC.7MAINSTEAMLINEBREAKDISPLACEDGEOMETRYWITHMAXIMUMSTRESSLOCATIONSFIGUREC.8PARAMETRICEVALUATIONOFBENDINGSTRESSVS.GAPWIDTH ARTICLEC.1DISCUSSIONOFTUBESTRESSASAFUNCTIONOFGAPMIDTHAsdiscussedearlier,amodificationtoSt.Lucie1uppertubesupportplateswasperformedin1978toremovetheouterrimandsupportinglugs.Basedonphotographstakenatthistimeagapconditionforsteamgenera-tors"A"and"B"existedbetweentheouterportionoftheseplatesandtheremainderofthesupportlugwhichisweldedtotheshroud.Thisgapvariedfrom0.7to1.3inchesatthattime.Nofurtherdataisavailablepres-ently,henceaparametricevaluationofthegapconditionforLOCArarefac-tionloadingswasperformedwiththeresultsillustratedinFigureC.8.Themaximumstressoccursforagapconditionof0.70"whichisusedinthisanalysis.Agapofabout1.15inchesappearstoproducethesmalleststress.Inconclusion,onecanstatethatthegapconditionhasthepoten-tialforchangingthemaximumLOCAstressesby25-30percent.ThereforetheLOCAimpulsestressobtainedfromananalysisofasimilarsteamgener-ator.withrigiddrillplatesupportscanbeamplifiedbyafactorof2.0,aswasdoneinthisanalysis,andshouldyieldconservativeresults. TABLEC.1LOCAANDSSESEISMICSTRESSESMODELROWMAXIMUMLOCAREDUCEDLOCASSESTRESSKSINODE123567891011121314151617181925.924.020.819.918.716.816.218.822.223.737.7234.628.721.920.721.922.422.123.019.4318.015;614.9314.0312.612.1514.116.6517.7828.2825.9521.5316.4315.5316.4316.816.5817.252.85.74.94.74.54.33.71.37.46.77.15.34.03.02.41.71.7.74.15053255801051301646822132382592843093348598849099349641TheLOCAStressesarereducedby25'XperAppendixD. I.OIWCNode469SeeFigureG.3.7"GaP-OrillPlateNode954VerticalSupportNode19DrillPlate-P~rtialEggcratepartialEggcrateSatuingFullcerateFIGUREA.3ANSYSFFNITEEI,EMENTMODELA.3 Node469DrillPlate-Node959DrillPlateNode19Partia1Eggorate'sLOCAStressSSEStressFZGUREC.lLOCAHAXIHUHSTRESSLOCATIONSC.3 / .812.825.837.858.862.875.887.188.112.125FIGUREC.2TIHEHISTORYOFLOCARENDINGSTRESSNODES259,284,309,334,and359 i 613686GrillPLate338883.5833888358FIGUREC.3GEOHEXRYATHAXINUNLOCASTRESSLOCATIONC.S R%+~~~wos

3DIP.21969XX59INE.812.825.837.858.862.875.887.188.112.125FIGUREC.5TIMEHISTORYDISPLACEMENTSpNODES19,259,and469C.7 C DI1~'yJj:NE.812.825.837.858.862;875.887.188.1]12.125FIGUREC.6TIHEHISTORYDISPLACEHENTS;NODES459and959C.S

40NODE9643025tA~CAcnC920MCQNODE25915NODE959,101.0GAP(IN)FIGUREC.8PARAMETRICEVALUATIONOFBENDINGSTRESSVS,GAPWIDTH1.5 L APPENDIXD'IMPORTANTFINDINGSFROMEPRI/CEPROJECTS144Abriefdiscussionregardingtheabovetestprogramispresentedinthissection.Theobjectivesoftheprogramare(i)toverifytheCEFLASHCodemodelingofthefluid-dynamicloadsinasteamgeneratortubeduringaLOCAand(ii)toverifythepredictedstructuralresponses.Thetestloopsimulatedtheprimarysidethermal-hydraulicconditionsinanoperationalnuclearsteamgenerator.Theloopconsistedoffivefullsizedouble90bendtubesandsteamgeneratorplena,apressurizer,a0reactorresistancesimulator,aheater,apump,andassociatedpipesandvalvestocompletethesystem.ThetubesusedwereoftypicallengthandthesameoutsidediameterasthoseusedinCfsteamgenerators.Prototypicalsupportswereprovidedforthebundleoffivetubes.SeeFigureD.1whichisaphotographoftheteststand.Coldlegguillotinebreaksweresimulatedusingquickopeningvalveandrupturedisks.Breakopeningtimesrangedfromlessthan1msectoasmuchas67milliseconds.TheloopinstrumentationwasdesignedtomeasurethetransientpressurehistoryatvariouslocationsandmonitorthestructuralresponseofthetubetotheLOCAhydrodynamicloading.Aseriesofblowdowntestswereperformedfordifferentoperatingandboundaryconditions.Theparametervariationsincludedfluidtemperature,pre-blowdownflowrate,breakopeningtime,breakopeningarea,andbreaklocation.Bothuniformandmixedlengthtubebundleswereused.Analyticallypredictedtransientpressurehistoriesandthedifferentialpressurehistoryacrossthetubespanwerecomparedwiththeexperimentaldata.SeeFigureG.2.Predictedstructuralresponsesinthebendregionwerealsocomparedwiththetestdata.ThetransientpressurehistoriesaspredictedbyCEFLASMwereinexcellentagreementwiththetestdata.Thecalculatedstructural'responsesofthetubealsohadgoodoverallagreementwiththetestdata.0.0

Duringthecourseofthetestprogram,mechanicaltestswereconductedtomeasurethestructuraldampingofthehorizontaltubespan.Itwasfoundtobe8Xofthecriticaldamping.Itwasalsoobservedthatthefrictionaland"binding"forcesintheverticalsupportreducedthepredictedbendingstressesanaverage34.3X.SeeTableD,l.AsshowninTableD.1,theanalyticallypredictedbendingstressesinthisreportwerelowered25.1X(34.3X-1standarddeviation9.2X=25.1%)totakeaccountofthefrictionandbinding. 44,~j~Pr,~I4((/~~~~~~~i~~FIGURE0,1EPRI/CEPROGRNIS144-1LOCABLOLJDONNSIMULATIONTESTSTAND0.2 ~I~Ett.A5ltCXPKRIMEHSAI.~!CSiCC:SC.C.S.CIA~VASS.CI~ISO~0C>FOROSV'-tttIKlN5KC00IIIIIII'ACCELERATjONA001CtOitI~9aoCH~IOINIISs0Ctl.tart<iO,ttvSSC,IjIIII~BaselineMeasuredandPredictedPressureDifferentialsBetweenTubeBendsIZ000O.OOO.OV0.00O.CO0.IO0.IZ0.IV0.IOtt~ISCC.IAccelerationatTubeMidspanTestA34I5IOSTRESSSGQQCIIiIOwltSICSICg.tRtingv0SC.35v555IOl5Nlbwgret~CIIUSILM0.0.00O.OV0.000.00O.IOC.llO.IVO.ISll+ISSC.IBendingStressesinTubeNearSupportPlate-TestA34FIGURE0.2COMPARISONBETWEENPREOICTEOANDMEASUREDFLUIDDYNAMICLOADINGANDSTRUCTURALRESPONSE-0.3 TABLED.tPALISADESSTEAMGENERATOR1.0CAANALYSISBATWINCiFRICTION-EPRITESTEPRITESTANSYSANALTestIDDescriptionBreakOpenT(Sec)Reports(ksi)Corrects(ksi)WithFPs(ksi)ReportNoFPs(ksi)XDueFrictA-28SmallerBreakArea(DownstreamOrifice).0175.55.710.712.246.7A-31A-37A-37ShortBreakLengthMixedHeightBundle(L'ongTube)MixedlleightBundle(ShortTube).016.014.0146.45.810.36.66.010.79.89.014.211.210.316.332~733.324.6AverageValueStandardDeviationSelectedValue(Avg-S)34.39.225.1 C APPENDIXEEVALUATIONOFNRCSTAFFCRITERIAARTICLEE.lPROCEDUREFORDETERMININGALLOWABLE,TWDTABLEE.lRELATEDDATAFORALLOWABLETWDDETERMINATIONFIGUREE.lEVALUATIONPERNRCREG.GUIDE1.121FIGUREE~2ALLOWABLETUBEWALLDEGRADATIONBASEDONLOCA+SSESTRESSESFORTUBEROWS117-123FIGUREE.3ALLOWABLETUBEWALLDEGRADATIONFORTOTALTUBEBNUNDLEFIGUREE.4MEMBRANEANDBENDINGINTERACTIONDIAGRAMFORCYLINDRICALTUBEE,O C ARTICLEE.1PROCEDUREFORDETERMININGALLOMABLETMDLOCA+SSEThemaximumallowablestressintensityforadegradedtubeforLOCA+SSEstressisdeterminedfromthefollowingequation:S.I.22.21/2LOCASSELOCAXA+a-e=f(0.7)SuRAREIMPi.'XP'rP=(EquationE.l)TheLOCArarefaction,impulse,andsafeshutdownearthquakestressesareevaluatedbytheSRSSprocedureforahealthytubeandthenamplifiedbythefactorA.whichistheratioofthesectionmodulusofadegradedtubetoahealthyone.Tubestressesduetoadeltapressure,primaryminussecondary,areincludedandcomparedtoanallowable,f(0.7S)wherefisuafunctionofcross-sectionalgeometryandtheratioofmembraneandbend-ingstressestoyieldstress.AninteractiongraphisshowninFigureE.4.Thiswasdevelopedforacylindricaltubecross-sectionformembraneandbendingstresses.TableE.lpresentsdatacalculatedforuseintheaboveequationforS.I.ThethreemodelrowswithmaximumLOCArarefactionstressesarell,12,and13correspondingtosteamgeneratortuberows117-118,119-121and122-124,respectively.ThesevaluesareshowninTableC.l.ModelRow11Evaluation:(UseTMD59%Input)S.I.=[(28.3)+(7.1)+(4)](2.559)+4.3+.82=80.5<Allow.=80.6ksi ModelRow12Evaluation:(UseTWD62%Input)S.I.=[(26)+(5.3)+(4))(2.776)+4.7+.82=79.9<Allow.=80.6ksi2221/2ModelRow13Evaluation:(UseTWD68%Input)S.I.=[(21.5)+(4)+(4)](3.305)+5.2+.82=79.6<Allow.=80.6ksiFiguresE:2andE.3showtheallowableTWDforthelocalizedregionandtheentiretubebundle.NSLB+SSEAllowableTWDisdeterminednormallybyconsideringstressesfromfoursources.1)MSLBflowloads,2)MSLBimpulseloads,3)Safeshutdownearthquakeand4)differentialpressure.Stressesresultingfrom1),3),and4)havebeendetermined.NSLBimpulserelatedmaximumstressisas-sumedtobe+6ksi,basedonananalysisofasteamgeneratorofsimilardesign,andisusedinthisportionoftheevaluation.ItshouldbenotedthatNSLBimpulserelatedstressesaregenerallysmallerthanMSLBflowstressesandwiththecombiningofstressesutilizingtheSRSSprocedure,theeffectofMSLBimpulsestressesontheresultantvalueisfurtherde-creased.TheworstcaseNSLB+SSEstressesaretakenfromSectionVIIIandusedtoevaluatetheallowableTWD.NSLBFlowStress=9.77ksiSSEStress7.6ksiMSLBImpulseStress=6.0ksiResultant=(9.77+7.6+6.0)=13.7ksiE.2

Solvingequation.E.lusinganallowableTWOestimateof66percent,thestressintensity,S.I.forMSLB+SSEis65.3ksi.TheallowableS.I.isf(.7)S=66ksibasedonavalueoff=1.18ob-utainedfromFigureE.4.TheratioofmembranestresstoyieldforInconeltubingis0.81asshownbelowandisrequiredtodeterminef.a=-='22.6ksii2.25.327m2tr=0.81.'.f=1.18fromFigureE.4m22.6Hence,themaximumallowableTWDforMSLB+SSEstressesis66percentwhichisnon-controlling.E.3 TABLEE.lRELATEDDATAFORALLOWABLETWDDETERMINATIONTWD585960616266686970t(IN).0201.0197.0192.0187.0182.0178.0163.0154.0149.0144R(IN).3471.3467.3462.3457.3452.3448.3433.3424.3419.3414ZDIN.006972.006828.006649.006471.006293.006151.005618.005286.005124.004948HIN.017470.017470.017470.017470.017470.017470.017470.017470.017470.017470A.ZH/ZD2.5062.5592.6272.7002.7762.8403.1103.3053.4093.531xP(KSI)4.34.34.44.64.74.85.25.65.75.84PRixP~trP>=1336psiP2=815psiWherehP=Pq-P2=0.521ksicr=0.815ksi((rremb)=g7g=0.18..f=1.44(FigureE.4)5SSE=2.2ksi(HealthyTubeatTimeandLocationofMaximumLOCAStress)0LOCA40ksi(HealthyTube)IMPE.4 4 1.NORMALOPERATION2.NORMALOPERATION3.STEAMLINEBREAKa<S=27.9KSI,600F3a<S=80.0KSI,600Fa<.7S=56.0ksi,600FNORNLOPERATINGPRESSURESrS-.P+P36PR'S+U~PRi07S-.P+PP>=2250psiaPz=815psiahP=1435psiSTEANLINEBREAKPg=0Pi=2250psia1.435.3273.65t=0.0178in.XAllow.Degradation(.048-.0178)X100.0483(1.435.327r8tr=0.0179in,XAllow.Degradation0100.048-,0179=632.25.327rtr=0.0134in.XAllow.Degradation0100='72FIGUREE.1EVALUATIONPERNRCREG.GUIDE1.121 CI I,!eIII'I1aIaa70III~a;aI..I{e~IIaa,I.I{,IIe~~~~I~\IaalII~I~II~~I~aIaIjr~I~eIaI~tI~I{.LOCA+SSE~I~I*~I':{~EIVALUAl'ION1j,I'il~."'IIj'"~IelII~IaIIIIIl~-~IIIj"IIIIIIII~~II~Ia-'--".66.MlC)~ic)6258IaI.I-i".I{I'IjI..~NRC']a~I.IIIIII,j~ACCEPTABLEREGIONSTAFF{leI-~4~-~Ia~~aROWi..NUMBER!I>>7.>>8>>9120'aiI~'{ICRITERIA',',I..I..j{'UBESPERROW46454443.V~a~I~IaIIII-Q5'6IIIALLOWABLETUBEIa1III140Ia'E'ROWS>>73123~"'EI~II1t7';-118,;j{119,120:121122:123aTUBEROMNUMBERII'r'IIli~I',.'FIGUREE.2.lI"WALLDEGRADATIONBASEDON'LOCA+SSEST!{ESSES.FORTUBt-eIIIaI~ el II,~jI~IIIIII',-801,',70-60'~rIIjIr~-II,II~Ii~IiII,iII)~'IIiIHRCSTAFFCRITERIA~~l'i'~"~~IIItrt".rIr'rIlj~II,i1~II~..LOCA+SSE;EVALUATIONh:/Ii-~1ICDI-C)CYC9C)IJJCOCDcC.50=4030I-'.2010I~IIIACCEPTABLEREGIONit.'I.II~!.III!IItIr.)I00~20.";-40ljrIi..=1'~IIl'I~~"ALLOWABLETUBEWALLi,FIGUREE.'3I-DEGRADATIONFORTOTjALTUBPBUNDLE'IIII6080'100ITUBEROMNUMBER120II~Irl~IiI140I r cP"M5-"CAVl,UJs~CY-li4UJCAUJCLI-1.3COC)LVCXl'-'4--:l2.~t~~~~s~~I,.(~63KDEGRADEDTUBE'IIHEALTHYTUBE~1~."'-..-.:-.j'I":00.20.40.60.81.0MEMBRANE"MEMBRANESTRESS/YIELDSTRESSFIGUREE,4ANDBENDINGINTERACTIONDIAGRAMFORCYLINDRICALTUBEI~>~~~IE.8

APPENDIXFFATIGUEANALYSISOFDEGRADEDTUBESThefatigueevaluationofadegradedtubeisbasedupontheconservativeassumptionof15,000cyclesfromambientconditionsto1005power.Theresultingalternatingstressintensityis(Ref.16,PageA-465)Slt=16.8ksiAstressconcentrationfactorforatubethatisdegraded63$isdeterminedbyconsideringastriponthetensionsideofthetubeandtreatingitasashoulderedplateintension.(Ref.17,Page178).DegradedZoneTransitionAreaAfullfilletradiusisassumed0.018"pdTR=.03h=.03d=.036D=.096d=D/dh0.65~h-Y0~6s=1.33Applying.thisstressconcentrationfactoryieldsSalt=(1.33)(16.8)=22.4ksi.Thisalternatingstressisgoodforcyclesinexcessof106(seeFigureI-9.2,Reference2).f/ence,theusagefactorisE.O 4r' ATTACHMENTEDETERMINATIONOFNOSIGNIFICANTHAZARDSCONSIDERATIONThestandardsusedtoarriveatadeterminationthatarequestforamendmentinvolvesnosignificanthazardsconsiderationareincludedintheCommission'sregulations,10CFR50.92,whichstatesthatnosignificanthazardsconsiderationsareinvolvediftheoperationofthefacilityinaccordancewiththeproposedamendmentwouldnot(I)involveasignificantincreaseintheprobabilityorconsequencesofanaccidentpreviouslyevaluated;or(2)createthepossiblityofanewordifferentkindofaccidentfromanyaccidentpreviouslyevaluatedor(3)involveasignificantreductioninamarginofsafety.Eachstandardisdiscussedasfollows:(I)Operationofthefacilityinaccordancewiththeproposedamendmentwouldnotinvolveasignificantincreaseintheprobabilityorconsequencesofanaccidentpreviouslyevaluated.TheproposedsteamgeneratortubewallacceptancecriteriahasbeendeterminedinaccordancewithRegulatoryGuidel.l2I.TheacceptancecriteriaisbasedonmarginsofsafetyconsistentwiththemarginsprovidedinSectionIIIoftheASMEBoilerandPressureVesselCode.Thedemonstratedmarginsofsafetyprovidereasonableassurancethattubefailurewillnotoccurduringoperatingoraccidentconditions.Therefore,theproposedchangewillnotresultinasignificantincreaseintheprobabilityorconsequencesofanaccidentpreviouslyevaluated.(2)Useofthemodifiedspecificationwouldnotcreatethepossibilityofanewordifferentkindofaccidentfromanyaccidentpreviouslyevaluated.Theproposedchangedoesnotchangetheconfigurationoftheplantorthewayinwhichitisoperated.Therefore,thechangedoesnotcreatethepossibilityforanewordifferentkindofaccidentfromanypreviouslyevaluated.(3)'Useofthemodifiedspecificationwouldnotinvolveasignificantreductioninamarginofsafety.ThesupportingsteamgeneratortubestressanalysismeetsthecriteriaofRegulator'yGuideI.I2I.Theproposedacceptancecriteriaisbasedonsafetyfactorsof3fornormaloperatingconditionsandI.Sforaccidentconditions.TheassociatedmarginsofsafetyareequivalenttothemarginsdeterminedbythestresslimitsofSectionIIIoftheASMEBoilerandPressureVesselCode.Thesemarginsofsafetyassurealowprobabilityfortubefailureduringoperatingoraccidentconditions.Therefore,theproposedchangedoesnotresultinasignificantreductioninamarginofsafety.Basedontheabove,wehavedeterminedthattheamendmentrequestdoesnot(I)involveasignificantincreaseintheprobabilityorconsequencesofanaccidentpreviouslyevaluated,(2)createtheprobabilityofanewordifferentkindofaccidentfromanyaccidentpreviouslyevaluated,or(3)involveasignificantreductioninamarginofsafety;andthereforedoesnotinvolveasignificanthazardsconsideration.EJW2/024/5 Vcrl~hvhv+f>>urv(~vv1-~l~4~I,cr'wr44$JI>>riv4>>54th'-4vr'4>>rril,~4ItI>>WW.l4Ili~41I4IvI"~..4vc,l,".>>A4"444Ii~i>>8441~*~4vlt.4~i'l,IIIJ"Ill')MIHltil'.1hvtI11'-/[IIII,4~h1~4bil~'uvlt"II4*Vi,Vuhc"IlhI1v1"II~>>"I,llti44h4t'Jkvlt-lt'hclv*"'1>>llIII4'I'.WII>>vI,4'fv'W~~~t4P,4ItI~I44-II,~4...I,'ll,44ILWIlh>>MI14il4.I,IIIJlIih'llIVWI'>>I'I,,4,IqlI-'I',h."A').;IHl14.,44lttvvc4JW1lrV'WCIVhcl1JVC44~li'h.,I~i'1'1IvhI1til.H<'Itf"i<,.ll'~viIIIIllih~4*~,ukill4Ill;4~1-J'ilHWW(flicI~4444t:~~,ihv,'I>>v".$ttgvuhhiff4IiH'lilhivlhhilvWW41It14~.Ii.~IvHw4I'tvr\IiHCH"I'IiilWI4atilwli,4vvuIHAut,c.>>44~44JIIJ44W4".~4Irc,>>4ilHl,III4I'IllI1VW.~I,j'4*14A~.IIHtlijl'1hl,WtjVC',rI>>441441IIlt4,It~(11>>J44,Illl-4"ICInJl.~1I.I444~4li44hitIhi'I4~I'.~il4 }}

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