ML17207A646

Forwards Evaluation of Design & Performance of Ref Core Configuration Utilizing Higher Enrichment Fuel.Requests NRC Approval by 800114 of Proposed Amend to Revise Max Enrichment Permitted by Tech Specs 5.3.1

ML17207A646
Person / Time
Site:	Saint Lucie
Issue date:	12/12/1979
From:	UHRIG R E FLORIDA POWER & LIGHT CO.
To:	EISENHUT D G Office of Nuclear Reactor Regulation
References
L-79-345, NUDOCS 7912140290
Download: ML17207A646 (57)

Text

ptREGULATORYFORMATIONDISTRIBUTIONSM(RIDS)ASCESSIONNBR07912140290DOCODATE~79/12/12NOTARIZED~NOFACIL:50335St.LuciePlantiUnft1iFloridaPower8LightCo,AUTH~NAME'AUTHORAFFILIATIONUMRIGgR~E~FloridaPower8LightCo,RECIP,NAMERECIPIENTAFFILIATIONEISENHUTrD,G.DivisionofOperatingReactorsDOCKET0'5000335SU8JECT!Forwardsevaluationofdesign8performanceofrefcoteconfigurationutilizinghighetenrichmentfue'I,RequestsNRCapprovalby800114ofproposedemendto,revisemaxenrichmentpermittedbyTechSpecs5,F1'ISTRIBUTIONCOBE:AOQISCOPIESRECEIVES:LTR~ENCL'SIZE:~+TITLE:General*DistributionforafterIssuanceofOperatingLicNOTES'ECIPIENTIDCODE/NAMEACTIONs05BCD/f8WQINTERNALREGF115COREPERFBR18REACSFTYBR20EEB22BRINKMANOELDEXTERNAL:03LPDR23ACRSCOPIESL'TlRENCL7711221111110111616RECIPIENTIDCODE/NAME02NRCPDR14TA/EDO17ENGRBR19PLANTSYSBR21KFLTTRTSYSEPBDOR04NSICCOPIESLTTRENCL>>1111111111111TOTALNUMBEROFCOPIESREQUIRED:LTTR39ENCL38 tM)I0lq'I'I'I'JAMIM~fy>>ltil'$fiiMhf>>i'IMIfM,,gkk)<If.>>IMMM'Ie(lII1IIIII0M'>>f'iieI>>'I'IF1"'IPi'Mt>>a53fh(>,~f>>h,Igys>>q~1M~fhI'Ihh'hII)",I,If.0f5~Ij'h')f,I'Mif>'>>lM)~>>f'i>>i'I'0IllfIMIf'MfII14o>>'A4IllfIMiif1>>hf&~>>C>>*Ifi,W')"'MI,,Mtf,M>>0fMf>>fflMIf>>cIIf4>MI>>*~i~*>>>>c>>ccw>>>>>>>>wc>>l=:.cc>>fFcIa>>>>4>>e~=.cKw>>OE-CC'IIiIII>>IIg,lI>>MYIM OfficeofNuclearReactorRegulationAttention:Mr.DarrellG.EisenhutActingDirectorDivisionof,OperatingReactorsU.S.NuclearRegulatoryCommissionWashington,D.C.20555

DearMr.Eisenhut:

P.O.BOX629100,MIAMI,FL331S2y<1lbgfi~~4xhFLORIDAPOWERSLIGHTCOMPANYDecember12,1979L-79-345Re:St.LucieUnit1DocketNo.50-335ReferenceExtended6cleSubmittalOnOctober4,1979(L-79-282),FloridaPower&LightCompany(FPL)submittedaproposedlicenseamendmenttorevisethemaximumenrichmentpermittedbyTechnicalSpecification5.3.1topermitgreaterflexibilityinassigningfuturecoredesignfeaturesandassociatedoperatingcyclelengthsforSt.LucieUnitl.Inordertocompletethereviewofthatproposedamend-ment,thestaffrequestedthatFPLsubmitanevaluationofthedesignandperformanceofareferencecore'configurationutilizinghigherenrichmentfuel.Inaccordancewiththatrequest,FPLhere-withsubmitssuchanevaluation.ThefourthfuelcycleforSt.LucieUnit1isthefirstcycleforwhichthehigherenrichmentfuelcanbeutilized,consequentlytheattachedevaluationisbasedonahigherenrichment.coreconfigur-ationwhichcouldbeutilizedforcycle4.ThehigherenrichmentcorecharacteristicshavebeenexaminedwithrespecttothesafetyanalysesforSt.LucieUnit1,Cycle3and,inallcases,theCycle3safetyanalysesenvelopethenewconditions.FPLmustreceiveNRCapprovalof'heproposedamendmentbyJanuary14,1980inordertoproceedwiththehigherenrichmentcoredesign.AdecisionaffectingmanufactureofthehighenrichmentfuelforCycle4mustbemadeatthattime.TheattachmenthasbeenreviewedandapprovedbytheFloridaPower&LightCompanyNuclearReviewBoardandtheSt.LucieFacilityReviewGroup.Vertryyours,RoberE.riVicePresidentAdvancedSystems&TechnologyREU/MAS/relAttachmentcc:Mr.JamesP.O'Reilly,RegionIIHaroldF.Reis,Esquire)b')918140QQ(gPEOPLE...SERVINGPEOPLE 0ST.LUCIEUNIT1REFERENCEEXTENDEDCYCLESUBMITTALI.INTRODUCTIONANDSUMMARYThisrepor'tprovidesanevaluationofthedesignandperformancefortheoperationofSt.LucieIduringitsfourthfuelcycleatthefullratedpowerof2560t1WT.Operatingconditionsremainthesameasthosef'rCycle3.Thecorewillconsistof'resentlytCoperatingBatchC,D,andEassembliestogetherwithfreshBatchF=assemblies.SystemrequirementshavecreatedaneedforflexibilityibtheCycle3burnuplengthrangingfrom-7250to8250tND/T.TheCycle4loadingpatterndescribedinthisreporthasbeendesignedtoaccommodatethisrangeofshutdownpoints.Inperforminganalysesofpostulatedaccidents,determininglimitingsafetysystemsettingsandestablishinglimitingcondi'tionsforoperations,valuesofkeyparameterswerechosentoassurethatexpected.conditionsareenvelopedwithintheaboveCycle3burnuprange.ThesleevingofCEAguidetubescausedbywearoftheCEAfingersfollowsthesameprocedureasreportedforCycle3inReference1.ForCycle4operation,onlysleevedassemblieswillbeplacedunderCEAsandall88BatchFass'emblieswillbesleeved.Theevaluationsofthereloadcorecharacteristicshavebeenexamined.-withrespecttothesafetyanalysesdescribingCycle3,(Reference2)hereafterreferredtoasthe"referencecycle".Inallcases,ithasbeenconcludedthatthereferencecycle.safetyanalysesproperlyenvelope1thenewconditions.Theresultofthisevaluationisthat'theoperationofCycle4requiresonlyoneTechnicalSpecificationchangeentailinganincreaseinallowedenrichmentfrom3.1w/oto3.7w/oU-235.

2.OPERATINGHISTORYOFTHEREFERENCECYCLESt.t,ucieUnitIispresentlyoperatinginitsthirdfuelcycleutilizingBatchB,C,D,andEfuelassembliesatalicensedcorepowerlevelof2560t'lAT.OperationofCycle3hascontinuedatornear'icensedpower.ItispresentlyestimatedthatCycle3willterminateduringMarch1980.ToallowforflexibilityintheCycle3terminationdate,arangeofburnupsbetween7250and8250tQD/Thasbeenanticipated.OperationofCycle4isscheduledtocommenceintrayorJune1980.

3.GENERALDESCRIPTIONTheCycle4corewillconsistofthenumbersandtypesofassembliesfromthevariousfuelbatchesasdescribedinTable3-1.TheprimarychangetothecoreforCycle4istheremovaloftheremaining21BatchBassembliesand67ofthe68BatchCassemblies.Theseassemblieswillbereplacedby40BatchF(3.65w/oenrichment)and48BatchF>>(3.03w/oenri'chment)"assemblies.The48lowenrichmentBatchF*assembliescontainburnablepoisonpinswith12pinsperassembly.Thelocationofpoisonpinswithinthelatticeisthesameasthatforpoisonpinassembliespresentinthereferencecycle.ThefuelmanagementpatterndevelopedforCycle4allowsforflexibilityinCycle3burnuplengthbetween7250and8250HWD/T."TheloadingpatternisshowninFigure3-1.TheCycle4coreloadingpatternis90degreesrotationallysymnetric.Thatis,ifonequadrantofthecorewererotated90degreesintoitsneighboringquadrant,eachassemblywouldoverlayasimilarassembly.Thissimilarityincludesbatchtyne,numberoffuelrods,initialenrichmentandbeginningofcycleburnup.Figure3-2showsthebeginningofCycle4assemblyburnupdistributionforaCycle3burnuplengthof7750t<WD/T.Theinitialenrichmentofeachassemblyisalsoshown.

Table'3-1St.LucieUnit1Ccle4CoreLoadinAssemblyDesignationNumberofAssembliesInitialEnrichmentw/oU-235BeginningofCycle4BatchAverageBurnupHHD/HTU(EOC3=7750HWD/T)InitialNumberShimofLoadingShimsw/0B4CTotalShimsTotalFuelRodsff*1402040.2840482.823.032.733.03'.733.653.0324,80015,70017,8006300930000000000123.030000005761767,0403,5207,0404,9287,0407,87221757637,616

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~eg~~~<<II<<IIIl<<IIIIIIIIII<<III~IIIII~II~olIIIII'llIIIIallIIeIII<<II'llIIIIIIIIII'llIIII<<II<<II'll0g8~~g) 4.0FUELDESIGN4.1MechanicalDesignThefuelassemblycomplementforCycle4isgiveninTable3-1.Themechanicaldesignofthereloadfuelassemblies,BatchFisidenticaltoSt.Lucie-1BatchEfuel.C-Ehasperformedanalyticalpredictionsofcladdingcreepcollapse,timeforallSt.Lucie-1fuelbatchesthatwillbeirradiatedduringCycle4andhasconcludedthatthecollapseresistanceof'llfuelrodsissufficienttoprecludecollapseduringtheirdesignlifetime.ThislifetimewillnotbeexceededbytheCycle4duration.TheresultsofthisevaluationareshowninTable4-1.TheanalysesutilizedtheCEPANcomputercode(Reference3)andincludedasinputconservativevaluesofinternalpressure,claddingdimensions,claddingtemperatureandneutronflux.4.2HardwareModificationstoMitigateGuideTubeHear.IIBatchC,D,E,andFfuelassembliestobeinstalledinCEAlocationsinCycle4willhavestainlesssteelsleevesinstalledintheguidetubesinordertomitigateguidetubewear.AdetaileddiscussionofthedesignofthesleevesanditseffectsonreactoroperationiscontainedinReference4.

4.3ThermalDesignUsingtheFATESmodel(Reference5),thethermalperformanceofthevarioustypesoffuelassemblieshasbeenevaluatedwithrespecttotheir'Cycles1,2,and3burnups,proposedburnups'uringCycle4,theirrespectivefuelgeometries,andexpectedfluxlevelsduringCycle4.TheBatchEfuelh'asbeendetermi'nedtobethelimitingfuelbatchwithrespecttostoredenerqy.4.4ChemicalDesignThemetallurgicalrequirementsofthefuelcladdingandthefuelassemblystructuralmembersfortheBatchFfuelhavenotbeenchangedfromtheoriginalCycles1,2,and3designs.Therefore,'hechemicalormetallurgicalperformanceoftheBatchFfuel>>illbeunchangedfromthatoftheoriginalcorefuelanddiscussionsintheFSAR,Reference6arestillvalid.4.5OperatingExperienceFuelassembliesincorporatingthesamedesignfeaturesastheSt.LucieUnit1,BatchFfuelassemblieshavehadoprating"experiencesatCalvert.Cliffs1and2,FortCalhoun1,HillstoneII,Maine-YankeeandpreviousreloadcyclesforSt.Lucie-l.TheoperatingexperiencehasbeensuccessfulexceptfortheCEAguidetubewearprohlenwhichhasbeenaddressedinSection4.2.

'Tamil4-i~PredictedgadCol)apseTiw>Coivpa~iktoI'rebec".edOperatingTir.~0 5.0NUCLEARDESIGN5.1PhysicsCharacteristics5.1.1FuelManagementTheCycle4fuelmanagementemploysamixedcentralregionasdescribed'nSection3,Figure3-1.ThefreshBatchFiscomprisedoftwosetsofassemblies,eachhavingauniqueenrichmentinordertominimizeradialpowerpeaking.Thereare40assemblieswithanenrichmentof3.65wt/U-235and48assemblieswithanenrichmentof3.03wt/U-235and12poisonshimsperassembly.Withthisloading,theCycle4burnupcapacityforfullpowerloperationisexpectedtobebetween14,300MWD/Tand14,900MWD/T,dependingonthefinalCycle3terminationpoint.TheCycle4corecharacteristicshavebeenexaminedforCycle3terminationsbetween7250and8250MWD/Tandlimitingvaluesestablishedforthesafetyanalyses.'heloadingpattern(seeSection3)isapplicabletoanyCycle3termina-tionpointbetweenthestatedextremes.PhysicscharacteristicsincludingreactivitycoefficientsforCycle4arelistedinTable5-1alongwiththecorrespondingvaluesfromthereferencecycle.PleasenotethatthevaluesofparametersactuallyemployedinsafetyanalysesaredifferentthanthosedisplayedinTable5-1andaretypicallychosentoconservativelybound.predictedvalueswithaccommodationforappropriateuncertaintiesandallowances.Table5-2presentsasummaryofCEAshutdownworthsandreactivityallowancesforCycle4withacomparisontoreferencecycledata.Table5-2generallycharacterizesthechangesinreactivitythatoccurduringatripfromfullpowerwithacorrespondingchangeincoreparameterstothezeropowerstate.Itisnotinte'ndedtorepresentanyparticularlimitingA00oraccident,althoughthequantityshownas"ShutdownMargin"representsthenumericalvalueoftheworthwhichisappliedtothehotzeropowersteamlinebreakaccident.FortheanalysisofanyspecificaccidentorAOO, conservativeor"mlimiting"valuesareused.aresultofpreviouslyestablishedconservativelimits,thescramworthscalculatedforCycle4areboundedbythevaluesusedintheCycle3safetyanalysis.Thepowerdependentinsertionlimit(PDIL)curveandCEAgroupidentificationareunchangedfromthereferencecycle(Reference2).,Table5-3showsthereactivityworthsof'ariousCEAgroupscalculatedatfullpowerconditionsforCycle4.5.1.2PowerDistributionFigures5-1through5-3illustratetheallrodsout(ARO)planarradialpowerdistributionsatBOC4,MOC4andEOC4thatarecharacteristicofthehighburnupendoftheCycle3shutdownwindow.These.planarradialpowerpeaksarecharacteristicofthe.majorportionoftheactivecorelengthbetweenabout20and80percentofthefuelheight.Figure5-4illustratestheplanarradialpowerdistributionwithintheuooer15to20oercentofthecoreproducedwiththeinsertionofthefirstCPAregulatinggroup,Bank7.ThispowerdistributioncharacteristicofnearBUC4isbaseauponthelowburnupendoftheCycle3shutdownwindow,providinganillustrationofmaximumpowerpeakingexpectedforthisconfiguration.HigherburnupCycle3shutdownpointstendtoreducepowerpeakinginthisupperregionofthecorewithBank7inserted.ItisacharacteristicofbothAROandBank7insertedconditionsthattheCycle4peaksarehighestatBOC.Theradialpowerdistributionsdescribedinthissectionarecalculateddatawithoutuncertaintesorotherallowances.However,singlerodpowerpeakingvaluesdoincludetheincreasedpeakingthatischaracteristicoffuelrodsadjoiningthewaterholesinthefuelassemblylattice.ForbothDNBandkw/ftsafetyandsetpointanalysesineitherroddedorunroddedconfigurations,thepowerpeakingvaluesactuallyusedarehigherthanthoseexpectedtooccuratanytimeduringCycle4.Theseconservativevalues,whichareusedinSection7ofthisdocument,.establishtheallowablelimitsforpowerpeakingtobeobservedduringoperation.

Therangeofallowableaxialpeakingisdefinedbythelimitingconditionsforoperationoftheaxialshapeindex(ASI).MithintheseASIlimits,thenecessaryDNBRandkw/ftmarginsaremaintainedforawiderangeofpossibleaxialshapes.Themaximumthree-dimensionalortotalpeakingfactoranticipatedinCycle4duringnormalbaseload,allrodsoutoperationatfullpoweris1.85notincludinguncertaintyallowancesandaugmentationfactors.ThisiswellwithintheoperatinglimitsestablishedforCycle3.5.1.3SafetyRelatedData5.1.3.1EjectedCEAThemaximumreactivityworthsandplanarradialpowerpeaksassociatedwithanejectedCEAeventareshowninTable5-4forbothBOCandEOC.Thesevalues-encompasstheworstconditions.anticipatedduringCycle4fortheplannedrangeofCycle3termination.pointsandareboundedbythevaluesusedinthesafetyanalysisforthereferencecycle.5.1.3.2DroppedCEAThelimitingparametersofdroppedCEAreactivityworthandmaximumincreaseinradialpeakingfactorhavebeencalculatedforCycle4.TheresultsindicatethatthevaluesuSedintheCycle3analysisarestillbounding.AcomparisonoftheseparametersforCycles3and4isfoundinTable5-5.

5.l.4AugmentationFactorsAugmentationfactorshavebeencalculatedfortheCycle4corekusingthecalculationalmodeldescribedinReference5.Theinputinformationrequiredforthecalculationofaugmentationfactorsthatisspecifictothecoreunderconsiderationincludesthefueldensificationcharacteristics,theradialpinpowerdistributionandthesinglegappeakingfactors.AugmentationfactorsfortheCycle4corehavebeenconservativelycalculatedbycombiningforinputthelargestsinglegappeakingfactors(calculatednearendofcycle)withthemostconservative(flattest)radialpinpowerdistribution.Thecalculationsyieldnon-collapsedcladaugmentationfactorsshowingamaximumvalueofl.048atthe-topofthecore.AsshowninTable5-6,theaugmentationfactorsforCycle3aremorelimitingthanthevaluescalculatedforCycle4.TheCycle3resultswereusedforthiscycle.8 hy5.2PHYSICSANALYSIStlETHODS5.2.l-UncertaintiesintreasuredPowerDistributionsThepowerdistributionmeasurementuncertaintieswhichareappliedtoCycle.4are:Fq'7.0percent,whereFq=Fxy'Fz,localpowerdensityFr=6.0percent.Thesevaluesaretobeusedformonitoringpowerdistributionparametersduringoperation.5.2.P.NuclearDesignt'jethodology/Theanalyseshavebeenperformedinthesamemannerandwiththesamemethodologiesusedforthereferencecycleanalyses.

~'TABLE5-1St.LucieUnit1Cycle4PhysicsCharacteristicsDissolvedBoronDissolvedBoronContentforCriticalit,CEAsMithdrawnHotfullpower,equilibriumxenon,BOCBoroni<orthHotFullPowerBOCHotFullPowerEOCUnitsPPHPPN/%apPPH/%apReference~Cc1e'509080~Cele4107710483ReactivityCoefficientsCEAsMithdrawnModeratorTemperatureCoeffi-cients,HotFullPowerBeginningofCycle(EquilibriumXe)EndofCycleDolerCoefficientHotBOCZeroPowerHotBOCFull'owerHotEOCFullPowerTotalDelayedNeutronFraction,geffBeginningofCycleEndofCycle10-4ap/'F10-4ap/'F105ap/'F105l4p/'F105ap/'F-0.2-1.8-1.44-1.1.31~22.0060.00510.0-1.9-1.64-1.26-1.39.0063.0051NeutronGenerationTime,a*BOCEOC10-6sec10-6sec28332429~~'

TABLE5-2St.LucieUnit1LimitingValuesofCycle4CEAREACTIVITYVORTHSANDALLOWANCES,/.dpBOCReferenceCycleReloadCycleEOCPeferenceCycleReloadCyclti'orthAvailable*WorthofallCEAsinsertedStuckCEAallowanceWorthofallCEAsless,highestworthCEAstuckout10.52'7.89.72.47.33.18.311.32.98,4i<orthReuiredAllowances)Powerdefect,HFPtoHZP{Doppler,Tavg,redistribution)HoderatorvoidsCEAbite,borondeadbandandmaneuveringbandRequiredshutdownmargin(Xdp)Totalreactivityrequired1.70.00.63.35.61.90.00.53~35.72.20.10.6.3.36.22.50.10.63'6:5Availablei<orthLessAllowancesMarginava-ilable2.2.1.62.11~9ForeveryaccidentorA00consideredinthesafetyanalysis,acalculationaluncertaintyof10Ãis.deductedfromtheworthavailable..

TABLE5-3ST.LUCIEUNITICYCLE4REACTIYITYk'ORTHOFCEAREGULATINGGROUPSATHOTFULLPOHER,%%dDPRegulatingCEAsGroup7Group6Group5BeginningofCycle0.570'10.32EndofCycle0.800.600.44NoteYaluesshownassumesequentialgroupinsertion.

TABLE5-4ST.LUCIEUNITICYCLE4CEAEJECTIONDATALimiting.ValueHaximumRadialPowerPeakFullpowerwithBank7inserted;worstCEAejectedLeropowerwithBanks7+6+5ins'erted;worstCEAejectedReferenceCycleSafetAnalsisValue3.608.34Cycle4CalculatedValue3.026.61MaximumE'ectedCEAWorthKhp)FullpowerwithBank7inserted;worstCEAejectedZeropowerwithBanks746+5inserted;worstCEAejected.29.65.20.50Notes:Uncertaintiesandallowancesareincludedintheabovedata.Referencecycleresultswerethoseusedintransientanalysis.

TABLE5-5St.Lucie-1Cycle4FullLengthCEADropDataLimitingValuesReferenceCcle~Cele4MinimumWorth%lNp.04.10MaximumPercentIncreaseinRadialPeakingFactor17Notes:(1)Houncertaintiesareincludedinabovedata.(2)CEAsareeitherfullywithdrawnorfullyinsertedforradialcalculations.(3)Referencecycleresultswerethoseusedintransientanalysis.

TA8LE5-6St.LucieUnit1AugmentationFactorsandGapSizesforCycle4andReferenceCycleCoreHeight~Percent)CoreHeight~Inches)ReferenceCcleNoncollapsedCladAugmen-tationFactorGapSize~inches)ReloadCcleNoncollapsedCladAugmen-tationFactorGapSize~Inches)98.586.877.966.254.445,633.822.113.21.5134,7118.6106.590.574.462.346,230.218.12.01.0581.0531.0501.0441.0381.0331.0261.0181.0131.0032.041.801.621.381.140.960.720.480.300.061.0481.0441.0411.0361,0311.0271.0211.0151.0101.0011.741.541.381.180.970.820.620.410.260.05Note:ValuesarebasedonapprovedmodeldescribedinReference5.

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lIIoIIIIIoa'olaiaIoIa'o)Io'aI'oIaIaI~I/II'eII05~l4~~J~ye)I'al 6.THERiLAL-HYDRAULICDESIGll6.1Dt(BRAnalysesSteadystateD[BRanalysesofCycle4attheratedpowerlevelof2560tie(thavebeenperformedusingthesamedesigncodesasdescribedintheFSAR,Reference6.AppropriateadjustmentsweremadetotheinputofthesecodestoreflecttheCycle4powerdistribution.Table6-1containsalistofpertinentthermal-hydraulicdesign'arametersusedforbothsafetyanalysesandforgeneratingreactorprotectivesystemsetpointinformation.Theanalyseswereperformedinthesamemannerasforthereferencecycle.6.2InvestigationshavebeenmadetoascertaintheeffectoftheCEAguidetubewearproblemandthesleevingrepaironD:IORmarginsas'stablishedbythistypeofanalysis.ThefindingswerereportedtothellRCinRefrence4whichconcludethatthewearproblemandthesleevingrepairdonotadverselyaffectDtSRmargin.EffectsofFuelRodBowingonDi(BRtlarginEffectsoffuelrodbowingonD'<DRrerginhavebeenincorporatedinthesafety.andsetpointanalysesinthesamemannerasdiscussedinReferencep'.ThisreferencecontainspenaltiesonminimumD/SRdueto.fuelrodbowingasafunctionofburnupgeneratedusingf(RCguidelinescontainedinReference8.

4GeneralCharacteristicsTotalHeatOutput(coreonly)FractionofHeatGeneratedinFuelRodUnitt'lg10BTU/hrReference~Cele3~Cele42560256087378737..975,.975PrimarySystemPressureNominalMinimuminsteadystateMaximuminsteadystateDesignInletTemperature,TotalReactorCoolantFlow(minimumsteadystate)CoolantFlowThroughCoreHydraulicDiameter(nominalchannel)AverageMassVelocityPressureDropAcrossCore(minimumsteadystateflowirreversibleaPoverent',refuelassembly)PSIAPSIAPSIA'FGPN1061b/hr1061b/hrft106lb/hr-ft2PSI225022002300544370,000140.2*135.0*0.0442.53*10.3225022002300544370,000140.2*135.0*0.0442.53*10.3TotalPressureDropAcrossYessel(basedonnominaldimensionsandminimumsteadystateflow)CoreAverageHeatFlux(accountsforabovefractionofheatgeneratedinfuelrodandaxialdensificationfactor)TotalHeatTransferArea(accountsforaxialdensificationfactor)FilmCoefficientatAverageConditionsMaximumCladSurfaceTemperatureAverageFilmTemperatureDifferenceAverageLinearHeatRateofUndensifiedFuelRod(accountsforabovefractionofheatgeneratedinfuelrod).AverageCoreEnthalpyRisePSI33.5BTU/kr-ft2'FoFoFkw/ft48,8605820657315.83BTU/lb65*BTU/h'r-ft2,'F174,40033.5174,310.48,8725820657315.8265**Calculatedatdesigninlettemperature,nominalprimarysystempressure.I TABLE6-1(continued)CalculationalFactorsEngineeringHeatFluxFactor,EngineeringFactoronHotChannelHeatInputInletPlenumNonuniformDistributionRodPitch,BowingandCladDiameterFuelDensificationFactor(axial)FuelRodBowingAugmentationFactoronFrStatisticalComponentofFr995/95ConfidenceLevelReference~C'cle31.031.031.051.0651.011.0181.06~Cele41.031.051.0651.011.018.1.06 7.0ACCIDENTTANDTRAtiSNTANALYSISOTHERTHAr<LOCAThepurposeofthissectionistopresenttheresultsofthesafetyanalysis(otherthanLOCA)forSt.LucieUnit1,Cycle4at2560t~iHTcontainingfuelassemblieswith3.65w/oenrichment.TheeventsconsideredforthisanalysisarelistedinTable7.1.Thesearethedesignbasiseventsfortheplant.Theseeventscanbecategorizedintothefollowinggroups:l.AnticipatedOperationalOccurrencesforwhichtheReactorProtectionSystempreventstheSpecifiedAcceptableFuelDesignLimits(SAFDLs)frombeingexceeded;2.AnticipatedOperationalOccu)rencesforwhichtheinitialsteadystateoverpowermarginmustbemaintainedinordertopreventtheSAFDLsfrombeingexceeded;3.PostulatedAccidents.EachoftheeventslistedinTable7-1hasbeenreviewedforCycle4todetermineifanexplicitreanalysiswasrequired'.Table7-1indicatestheanalysisstatusofeachevent.Table7-2presentsthecoreparametersused.intheCycle4analysisandcomparesthemtothereferencecycle.Thereviewofeachdesignbasisevent(DBE)entailedacomparisonbetweenallthecurrentandreferencecyclekeytransientparamet'ersthatsignificantlyimpacttheresultsofanevent.Thereferenceanalysisforeacheventistheanalysisuponwhich'helicensingofSt.LucieUnit1,Cycle3wasbased.llhenthecurrentcyclevaluesofkeyparametersforaparticulareventareboundedby(conservativewithrespectto)thereferencecycle,noreanalysisisrequiredorperformed.TheresultsofthereviewarethatthekeyparametersforalltheDBEsforCycle4operationarethesameas,ornoworsethan,thespecifiedreferencecycleinputparameters,exceptforthefollowing:1.Highercriticalboronconcentration2.SeizedRotorpincensus3.CEAEjectionpincensusAreanalysis"oftheBoronDilutioneventwasperformedtodeterminetheeffectsofthemoreadverseboronparametersforCycle4.TheseizedrotoreventandCEAejectioneventwerereanalyzedtoevaluate'the,impactofmoreadversepin.censusfor,thesepostulatedevents.ForallDBEsotherthanthosereanalyzed,'theSt.LucieUnit1safetyanalyses-forpreviousrelopdcyclelicensesubmittalsbouncLtheresultsthatwouldb'eobtainedforUnit"1,Cycle4anddemonstratesafeoperationofSt.LucieUnit1Cycle4at2560llWTwiththehigherenrichment.fuel.Insummary,theresultsofthereanalysisdemonstratethattheconclusionsreachedinthereferencecycleanalysisforeacheventremainvalidforCycle4.

TABLE7-1St.LucieUnit1,Cycle4EventsConsideredinTransientandAccidentAnalysisAnticipatedOperationalOccurrencesforwhichtheRPSAssuresnoViolationofSAFDLs:I'lliS<<ControlElementAssemblyWithdrawalBoronDilutionSt~tr)pofanInactiveReactorCoolantPumpExcessLoadLossofLoadLossofFeedwaterFlowExcessHeatRemovalduetoFeedwatertlalfunctionRea'ctorCoolantSystemDepressurizationLossofCoolantFlowLossofACPower'-NotReanalyzedReanalyzedNotReanalyzedHotReanalyzedNotReanalyzedHotReanalyzedNotReanalyzedNotReanalyzedHotReanalyzedNotReanalyzedAnticipatedOperationalOccurrenceswhichareDependentonInitialOverpowerMarginforProtectionAgainstViolationofSAFDLs:LossofCoolantFlowLossofACPowerFullLengthCEADropPartLengthCEADropPartLengthCEANalpositioningTransientsResultingfromMalfunctionofOneSteamGeneratorHotReanalyzedNotReanalyzedNotReanalyzedHotReanalyzedNotReanalyzedNotReanalyzedPostulatedAccidents:CEAEjectionSteamLineRuptureSteamGeneratorTubeRuptureSeizedRotorReanalyzedNotReanalyzedNotReanalyzedReanalyzed1RequiresLowFlowTrip.

TABLE7-2St.Lucie1CoreParametersInputtoSafetyAnalyses'hsicsParametersPlanarRadialPeakingFactorsUnitsReferenceCycle4~C1I1VForDNBMarginAnalyses(Fr)UnroddedRegionBank7Inserted1.591.801.591.80ForPlanarRadialComponentof3-DPeak(Fx)(kw/ftLimitAnalyses)UnroddedRegionBank7InsertedPeakAugmentationFactorModeratorTemperatureCoefficientShutdownMargin(YalueusedinZeroPower)(SLB)(1loop/2loop)1.581.821.0711.581.821.071.10bp/F-2.5~+.5-2.5~+.-4.1/-3.3-4.1/-3.SafetParametersPowerLevelMaximumSteadyStateCoreInletTemperatureMinimumSteadyStateRCSPressureReactorCoolantCoreFlowFullPowerAxialShapeIndexLimitMaximumCEAInsertionatFullPowerMinimumAllowableInitialPeakLinearHeatRatefortransientsotherthanLOCASteadyStateLinearHeatRatetoFuelCenterlineMeltCEADropTimefromRemovalofPowerHolding.Coilsto90%InsertionThreePumpPlenumFactorNHtoFpsia10lb/hrIp%InsertionofGroup7kw/ftkw/ftSec2611'442200134.9"0232516.021,03.11.0926115442200.134.9~2316.021.03.11.09 J

TABLE7.1-1AssumedInputParametersforBoronDilutionAnalysisParameterRef.Cycle~212~Cele4CriticalBoronConcentration,PPt1(AllRodsOut,ZeroXenon)PowerOperationStartupHotStandbyHotShutdownColdShutdownRefueling120013001300130013001200133014201420142014201280InverseBoronWorth,PPt</%apPowerOperationStartupHotStandbyHotShutdownColdShutdownRefueling70655555959070707070 7.1BORON'DILUTIONEVENTTheBoronDilutioneventhas,beenreanalyzedforCycle4duetoincreasesinthecriticalboronconcentrations(SeeTable7.1-1forcomparisonbetweenCycle2andCycle4boronparameters.ThisisthesamereferencecyclethatwascitedintheCycle3licensesubmittal).Thisincreaseincriticalboronconcentrationisoffsetbyacorrespondingincreaseintheminimuminverseboronworth.Thus,thetimetodilutetocriticalityforCycle4isnolessthanthetimecalculatedforthereferencecycle.TheBoronDilutioneventatpowerproducesaslowpowerandtemperatureincreasewhichcausesanapproachtoboththeDNBRandkw/ftSAFDLs.SincetheTtl/LPtripsystemmonitorsthetransientbehaviorofcorepowerlevelandcoreinlettemperature,theTt1/LPtripassuresthattheDNBRSAFDLisnotexceededforpowerincreaseswithinthesettingoftheVariableHighPowerLeveltrip;forpowerexcursionsinexcessoftheVariableHighPowerLeveltrip,areactortripisactuated.Theapproachtothekb/ftSAFDListerminatedbyeithertheLocalPowerDensity-Hightrip,VariableHighPowerLeveltriportheDNBRrequiredtripdiscussedabove.Forborondilutioninitiatedfromhotzeropower,critical,thepowertransientresultingfromtheslowreactivityinsertionratecharacterizingtheborondilutiontransientisterminatedbytheVariableHighPowerLeveltrippriortoapproachingtheSAFDLs.There-evaluationshowsthetimetocriticalityisgreaterthan15minutesforborondilutionsinitiatedfromtheStartup,HotStandby,HotShutdown,andColdShutdownoperationalmodes.Forthere-fuelingmode,thetimetocriticalityisgreaterthan30minutes.Consequently,theconclusionsreachedforCycle2remainvalidforCycle4.

7.2SEIZEDROTOREVENiTheSeizedRotorEventwasreanalyzedforCycle4toevaluatethe'numberoffuelpinspredictedtoexperienceDflBduetoaslightlymoreadversepincensusdistributionforCycle4thanforthereferencecycle.(ReferencecycleforthiseventisCycle3.)Thetransientbehaviorofthiseventisthesameasforthereferencecyclesinceall'hetransientrelatedparametersarethesameas,orconservativewithrespectto,thereferencecycle.Therefore,onlyarecalculationofthenumberoffuelpinspredictedtoexperienceDNBwasperformedusingthecycle4pincensus.Theresultsshowthat,forCycle4,thenumberoffuelpinspredictedtoexperienceDNBis1.05/,ascomparedtothe0.99~reportedforCycle3.Therefore,theconclusionreachedinthereferencecyclethatonlyaverysmallnumberofthefuelpinswouldexperienceDNB'emainsvalidforCycle4.

7.3CEAEJECTIONEVENT0TheCEAEjectionEvent,wasreanalyzedforCycle4toevaluatethenumberof'uelpins.predictedtoexperienceincipientcenterline'eltduetoaslightlymoread'versepincensusdistributionforCycle4thanforthereferencecycle.(ReferencecycleforthiseventisCycle3.)Inthereferencecycle,nopinwaspredictedtoexceedthecriterionforcladdamage(i.e.,averagedepositedenergyof200cal/gm).Thetransientbehaviorofthiseventisthe.sameasforthereferencecyclesinceallthetransientrelatedparametersarethesameas,orconservativewithrespectto,thereferencecycle.Therefore,onl'yarecalculationofthenumber,offuelpinspredictedtoexperienceincipientcenterlinemeltingwasperformedusingthecycle4pincensus.Theresultsshowthat,forCycle4,thepredictedfractionoffuelpinsexpectedtoexperienceincipientcenterlinemeltingforthetransientinitiatedatfullpoweris0.045.Forthereferencecycleanalysis,acalculatedfractionalvalueof0.028ofthefuelpinswerepredictedtoexpelienceinciointcenterlinemeltingatfullpower.However,sincenofuelpinispredictedtoexperiencecladdamage,theconclusionreachedinthereferencecycleremainsvalid.

References(SectionsIthrough7)1.CEN-79-P,"ReactorOperationWithGuideTubeHear",February3,19782.Letter,RobertE.Uhrig(FPSL)toVictorStello(NRC),datedFebruary22,1979,"St.LucieUnit1DocketNo.50-335ProposedAmendmenttoFacilityOperatingLicense-.DPR-67"3.5.6.CENPD-187,"CEPANmethodofAnalyzingCreepCollapseofOvalCladding",June1975CEN-80(N)-P;"MillstoneUnit2.ReactorOperationWithttodifiedCEAGuideTubes",February8,1978CENPD-139,"C-EFuelEvaluationHodelTopicalReport",July1,1974St.LucieNuclearPowerPlant(FormerlyHutchinsonIsland)UnitOne,FinalSafetyAnalysisReport,insupportofDocketNo.50-3357,Supplement3-P(Proprietary)toCENPD225P,"FuelandPoisonRodBowing",June1979LetterfromD.B.Vassallo(NRC)toA.E.Scherer(C-E)datedJune12,1978.

St.LucieICycle4ECCSPerformanceResultsIINTRODUCTIONANOSUt<HARYTheECCSperfora>anceevaluationforSt.LucieICycle4,presentedherein,'emonstratesappropriateconformancewiththeAcceptanceCriteriaforLight-Water-CooledReactorsaspresentedin10CFR50.46.Theevaluation(1)demonstratesacceptableECCSperformanceatapeaklinearheatgenerationrate(PLHGR)of14.8kw/ftandapowerlevelof2611that(102Ãof2560t'lwt).Themethodofanalyisandresultsarepresentedinthefollowingsections.HETHODOFANALYSISThisanalysiswasperformedusingtheapprovedC-ELargeBreakEvaluation(2)tlodel.Themodelwasusedtore-evaluatethelimitinglargebreakLOCAECCSperformance.Theblowdownandrefill-refloodparametersofthepreviouscycleremainunchanged.Therefore,onlySTRIPINII()calculationswerenecessarytoaccountforthedifferentpinconditions.BurnupdependentcalculationswereperformedusingtheFATESand(5)STRIKIN-IIcodestodeterminethelimitingconditionfortheECCSperformanceanalysis.Thebreaksizeandtypeanalyzed,0.8DES/PD*,isthesameaswasanalyzedinpreviouscycles.Forconservatism,thePARCHcodewasnotutilizedintheCycle4evaluation~ThelaterefloodheattransferbenefitfromtheuseofthePARCHsteamcoolingheattransferwouldhavereducedthepeakcladtemperaturereportedherein.*0.9xDoubleEndedSlotBreakintheReactorCoolantPumpDischargeLeg O

8.2RESULTSANDCONCLUSIONSTable1presentstheanalysisresultsforthelimiting0.8DES/PDbreak.AlistofthesignificantparametersdisplayedgraphicallyispresentedinTable2.AsummaryofthefuelandsystemparametersisshowninTable3.Ascanbeseenfromtheresults,theworstbreakanalysisresultsinapeakcladtemperatureof1986'Fwhichiswellbelowtheciiterialimit.Thelocalandcorewid(zirconiumoxidationpercentagesare10.49%and0.60'i,,respectively.Hence,opera-stionatapeaklinearheatgenerationrateof14.8kw/ftandatapowerlevelof2611Hwt(102Kof2560Hwt)willresultinacceptableECCSperformance.3COHPUTERCODEVERSIONIDEHTIFICATIONThefollowingNRC-approvedversionofCombustionEngineeringECCSEvaluationI'1odelcomputercodewasusedinthisanalysis:STRIKIH-II:VersionNo.77036 REFERENCES(Section8)l.AcceptanceCriteriaforEmergencyCoreCoolingSystemsforLight-MaterCooledNuclearPowerReactors,FederalRegister,Vol.39,No.3-Friday,January4,1974.2.CENPD-132,"CalculativeNethodsfortheCELargeBreakLOCAEvaluationModel",August1974(Proprietary).CENPD-132,Supplement1,"CalculationalMethodsfortheCELargeBreakLOCAEvaluationModel",December1974(Proprietary).CENPD-132,Supplement2,"CalculationalmethodsfortheCELargeBreakLOCAEvaluationModel",July1975(Proprietary).3.LetterfromFPSLtollRCtransmittingSt.LucieICycle3ECCSperformanceresults(February22,1979;L-79-45),4.CENPD-135,"STRIKIN-II,ACylindricalGeometryFuelRodHeatTransferProgram",August1974(Proprietary).CENPD-135,Supplement2,"STRIKIN-II,ACylindricalGeometryFuelRodHeatTransferProgram(Modifications),February1975(Proprietary).CENPD-135,Supplement4,"STRIKIN-II,ACylindricalGeometryFuelRodHeatTransferProgram",August1976(Proprietary).CENPD-135,Supplement5,"STRIKIN-II,ACylindricalGeometryFuelRodHeatTransferProgram",April1977(Proprietary).5.CENPD-139,"CEFuelEvaluationl1odel",July1974(Proprietary).6.CENPD-138,"PARCH-AFORTRAN-IVDigitalProgramtoEvaluatePoolBoiling,AxialRodandCoolantHeatup",August1974(Proprietary).CENPD-138,Supplement2,"PARCH-AFORTRAN-IVDigitalProgramtoEvaluatePoolBoiling,AxialRodandCoolantfleatup",January1977(Proprietary).

TABLE1SummaryofResultsforSt.LvcieICycle4ECCSPerformanceResultsBreakPeakClad~TtTimeof~ttTTimeofCladRutureOxidation/LocalCoreBi-de0.8DES/PD1986'F249.Zsec55.32sec10.49-(.60.

St.LucieICycle4VariablesPlottedasaFunctionofTimeVariables~FiureD~esinationPeakCladTemperatureHotSpotGapConductancePeakLocalClad.OxidationCladTemperature,CenterlineFuelTemperature,AverageFuelTemperatureandCoolantTemperatureforHottestNodeHotSpotHeatTransferCoefficientHotRodInternalGasPressure~13 VaTABLE3St.LucieICycle4GeneralSystemParametersQ~uantitValueReactorPowerLevel(102%ofNominal)AverageLinearHeatGenerationRate(102KofNominal)PeakLinearHeatGenerationRateGapConductanceatPLHGRFuelCenterlineTemperatureatPLHGRFuelAverageTemperatureatPLHGRHotRodGasPressureHotRodBurnup26116.093214.815273510.32195.61035.81488Hwtkw/ftkw/ftBTU/hrft'FoFoFpsiat@lD/t)TU IoIIIIIIIllew~~I<<IIatll~ll<<llllII~II 1ollaIlIII'i~'l~~a~IggI1IallallSlIISl~IIIl~II k~I'I'1)IO'I'III'J~tlSl~IIII 0e

~lg0gIIIt~~g~IIjSSSillSISSlSl

~II~IP~II~IiIIlIIIIIIIII I'I'IIIL~)IIoiloilIIIIIIIl 0Pt4]lIr