ML18040B150

Forwards Application for Proposed Amend 39 to License NPF-22,revising Tech Specs to Support Cycle 2 Reload.Fee Paid

ML18040B150
Person / Time
Site:	Susquehanna
Issue date:	06/19/1986
From:	KENYON B D PENNSYLVANIA POWER & LIGHT CO.
To:	ADENSAM E Office of Nuclear Reactor Regulation
Shared Package
ML17146A415	List: ML17146A414 ML17146A416 ML17146A417 ML17146A419 ML17146A421 ML17146A422 ML17146A423 ML18040B150
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PLA-2661, NUDOCS 8606240301
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REQULATYINFORMATIONDISTRIBUTIQNYSTEI'l(RIDS)ACCESSIQNNBR:8606240301DOC.DATE:Sb/06/19NOTARIZED:YESFACIL:50-388SusquehannaSteamElectricStationsUnit2.PennsglvaAUTH.NAt'tEAUTHORAFFILIATIONKENYON'.D.PennsylvaniaPotoer5LightCo.RECIP.NANERECIPIENTAFFILIATIONADENSAI'1pE.BWRProspectDirectorate3[)g

SUBJECT:

ForwardsapplicationforproposedAmend39toLicenseNPF-22'evisingTechSpecstosupportCycle2reload.Feepaid.DISTRIBUTIONCODE:ACOIDCOPIESRECEIVED:LTR8ENCLRSIZE:TITLE:OR,Submittal:l'eneralDistributionNOTES:icyNNSS/FCAF/PN.LPDR2cgsTranscripts.DOCKET¹0500038805000388RECIPIENTIDCODE/NANEBWREBBWRFOBBWRPD3PD01BWRPSB09INTERNAL:ACRSELD/HDS4NRR/ORASRONDCOPIESLTTRENCLSSlyRECIPIENTIDCODE/NANEBWREICSBBWRPD3LACANPAQNONEBWRRSBADN/LFNBNRR/T/TSCB04COPIESLTTRE'CL2EXTERNAL:EQ8(QBRUSKE>SNRCPDR02NOTES:33LPDRNSIC03050/>1TOTALNUNBEROFCOPIESREQUIRED:LTTR33ENCL

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PennsylvaniaPower8LightCompanyTwoNorthNinthStreet~Allentown,PA18101~215i770.5151BruceD.KenyonSeniorVicePresident-Nuclear215/770-41S4JUN$91986DirectorofNuclearReactorRegulationAttention:Ms.E.Adensam,ProjectDirectorBWRPro)ectDirectorateNo.3DivisionofBWRLicensingU.S.NuclearRegulatoryCommissionWashington,D.C.20555SUSQUEHANNASTEAMELECTRICSTATIONPROPOSEDAMENDMENT39TOLICENSENO.NPF-22PLA-2661FILESR41-2,A7-8CDocketNo.50-388

DearMs.Adensam:

ThepurposeofthisletteristoproposechangestotheSusquehannaSESUnit2TechnicalSpecificationsinsupportoftheensuingCycle2reload.ChangestothefollowingTechnicalSpecificationsarerequested:1.03/4.1.23/4.2.13/4.2.23/4.2.33/4.2.43/4.3.4.23/4.4.1.1.23/4.7.85.3.1B2.1B3/4.1.1B3/4.1.2B3/4.1.3B3/4.1.4B3/4.2.1B3/4.2.2B3/4.2.3B3/4.2.4B3/4.4.1B3/4.7..8IndexDefinitionsReactivityAnomaliesAveragePlanarLinearHeatGenerationRateAPRMSetpointsMinimumCriticalPowerRatioLinearHeatGenerationRateEnd-of-CycleRecirculationPumpTripSystemInstrumentationRecirculationLoops-SingleLoopOperationMainTurbineBypassSystemFuelAssembliesSafetyLimitsShutdownMarginReactivityAnomaliesControlRodsControlRodProgramControlsAveragePlanarLinearHeatGenerationRateAPRMSetpointsMinimumCriticalPowerRatio~e0LinearHeatGenerationRateRecirculat:ionSystemMainTurbineBypassSystem,p>i8606240301860619PDRADOCK05000388PPDR 1~NKCrt,ptprplt1'I~hIII;IPh~i..'pP.P',t4I'<<PI~14ItI1I~rh44I!II4~4h)4*~.,~$

Page2SSESPLA-2661FilesR41-2,A7-8CMs.E.AdensamAsdiscussedina'teleconhei'dwithyourstaffonJune16,1986,andintheattached'reloadsummaryreport,thissubmittaldoesnotcontainMinimumCriticalPowerRatio(MCPR)TechnicalSpecificationLimits.Themethodologywhichwillbeusedtoderivetheselimitsisbeingprovidedatthistimeforyourreview;theactualvalueswillbesuppliedinmid-July.Thefollowingattachmentstothisletterareprovidedtoillustrateandtechnicallysupporteachofthechanges:Marked-upTechnicalSpecificationChangesNoSignificantHazardsConsiderationsSusquehannaSESUnit2Cycle2ReloadSummaryReportXN-NF-86-60,"SusquehannaUnit2Cycle2ReloadAnalysis,"May,1986XN-NF-86-55,"SusquehannaUnit2Cycle2PlantTransientAnalysis,"May,1986XN-NF-86-65,"SusquehannaLOCA-ECCSAnalysisMAPLHGRResultsfor9X9fuel,"May,1986SusquehannaSESUnit2Cycle2ProposedStartupPhysicsTestsSummaryDescription,May,1986PleasenotethatwithrespecttothermalhydraulicstabilityoftheExxonNuclearCompany9X9fuelbeinginsertedduringthisreload,PP&Lhasalreadysubmitted(PLA-2637,datedApril30,1986)astabilitytestprogramwhichwillsupplementtheresultspresentedinthepertinentanalysesattached.CertainothersupplementarydatawillalsobesubmittedtotheNRCattheirrequestinaccordancewithourdiscussionsonMay30,1986.Itisnotourintenttotreatanyofthissupplementaryinformationasrevisionstothisproposal.Also,sufficientanalysishasnotbeencompletedtosupportSingleLoopOperation(SLO)withthe9X9fueldesign.TheTechnicalSpecificationshavebeenalteredaccordingly,andwewillprovideaseparatesubmittalonthisissuebasedonappropriateanalysiswhenitisavailable.Again,thissubmittalisnottobeconsideredarevisiontothisproposedamendment.SusquehannaSESUnit2iscurrentlyscheduledtobeshutdownforrefuelingandinspectiononAugust2,1986andtorestartasearlyasOctober3,1986.Werequestthatyourapprovalbeconditionedtobecomeeffectiveuponstartupafterthisoutage,andwillkeepyouinformedofanyschedulechanges.

~IhIeeeIe~4)P,l,4'lte4h(h>>CepIe'feehP~'Ie~>"Ita4I4I~II4'"'heII',I'P'I'4It4eVI Page3SSESPLA-2661FilesR41-2,A7-SCMs.E.AdensamAnyquestionswithrespecttothisproposedamendmentshouldbedirectedtoMr.R.Sgarroat(215)770-7855.Pursuantto10CFR170,theappropriatefeeisenclosed.Verytrulyyours,B.D.KenySeniorVicePresident-NuclearAttachmentscc:M.J.Campagnone-USNRCR.H.Jacobs-USNRCT.M.GeruskyBureauofRadiationProtectionPennsylvaniaDepartmentofEnvironmentalResourcesP.O.Box2063Harrisburg,PA17120

(.~p~I~hR'q~t)v'>>.1f't1'elW0t,n XN-NF-86-55IssueDate:5/]5/86SUSQUEHANNAUNIT2CYCLE2PLANTTRANSIENTANALYSISPreparedby:T.H.Keheley,TeamLeaderBWRSafetyAnalysisConcur:R.EDollingh,ManagerBWRSafetyAlysisConcur:J.N.Horgan,HagerCustomerServicesEngineeringConcur:G.N.Ward,ManagerReloadLicensingApprove:H.E.Williamson,ManagerLicensing&SafetyEngineeringApprove:G.L.Ritter,ManagerfuelEngineering&TechnicalServicesthk/mlnEQONNUCLEARCOMPANY,INC.,860624030>

NUCLEARREGULATORYCOMMISSIONDISCLAIMERIMPORTANTNOTICEREGARDINGCONTENTSANDUSEOFTHISDOCUMENTPLEASEREADCAREFULLYThistechnicalreportwasderivedthroughresearchanddevelopmentprogramssponsoredbyExxonNuclearCompany,Inc.Itisbeingsub.mittedbyExxonNucleartotheUSNRCaspartofatechnicalcontri-butiontofacilitatesafetyanalysesbylicenseesoftheUSNRCwhichutilizeExxonNudear.fabricatedreloadfuelorothertechnicalservicesprovidedbyExxonNuclearforlichtwaterpowerreactorsanditistrueandcorrecttothebestofExxonNuclear'sknowledge,informaaon,andbegef.TheinformationcontainedhereinmaybeusedbytheUSNRCinitsreviewofthisreport,andbylicenseesorapplicantsbeforetheUSNRCwhicharecustomersofExxonNuclearintheirdemonstradonofcompliancewiththeUSNRC'sreguladons.Withoutderogatingfromtheforegoing,neitherExxonNuclearnoranypersonactingnnitsbehalf:A.Makesanywarranty,expressorimplied,withrespecttotheaccuracy,completeness,orusefulnessoftheinfor.mationcontainedinthisdocument,orthattheuseofanyinformation,apparatus,method,orprocessdisclosedinthisdocumentwillnotinfringeprivatelyownedrights;orB.Assumesanyliabilitieswithrespecttotheuseof,orfordan'agesresultingfromtheuseof,anyinformation,ap.paratus,method,orprocessdisclosedinthisdocument.XN.NF-FOO,7BB XN-NF-86-55TABLEOFCONTENTSSectionPacae

1.0INTRODUCTION

..........................................12.0UHMARY'~~~~~~~~~~~~~~~~~~~~~~o~~o~o~~~~~~~~~~~~~~~~2S3.0TRANSIENTANALYSISFORTHERMALMARGIN..................43.1DesignBasist~~~~~~~~~0~~~~~~~~~~~~~~~43.2AnticipatedTransients................................53.2.13.2.23.2.3LoadRejectionWithoutBypass........~~~~~~~~~~5LossofFeedwaterHeating.............................7FeedwaterControllerFailure..........................63.3CalculationalModel....................................83.4afetyLimit..........................................8S4.0ANALYSESFORINCREASEDCOREFLOW(ICF)ANDFINALFEEDWATERTEMPERATUREREDUCTION(FFTR)...........195.0MAXIMUMOVERPRESSURIZATION............................225.1D0esignBasis.....................................225.2PressurizationTransients.............................225.3ClosureofAllHainSteamIsolationValves.............236.0RECIRCULATIONPUMPRUN-UP.."............................2

47.0REFERENCES

............................................26APPENDIXA...:.............~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

XN-NF-86-55ListofTablesTablePacae2.1TransientAnalysisResultsatDesignBasisConditions........................................33.13.23.33.4ReactorDesignandPlantConditionsSusquehannaUnit2...................SignificantParameterValuesUsedinSusquehannaUnit2Analysis..........ResultsofPlantTransientAnalysis..FWCFResultsat100%Flow............~~~~~~~~~~~~~t~~~09~~~~~~~~~~~~~.10~~~~~~~~~~~~~~~~~~13144.14.2ResultsofSystemPlantTransientAnalysisatICFandFFTR................................20FeedwaterControllerFailureDeltaCPRResultsofICFandFFTRAnalyses..............21

}4~~~

XN-NF-86-55ListofFiuresFiciurePa(ac3.13.23.33.4LoadRejectionWithoutBypass..........................15LoadRejectionWithoutBypass...........16FeedwaterControllerFailure......................17FeedwaterControllerFailure...........................186.1ReducedFlowHCPROperatingLimit.....................25A-3.1A-3.2A-3.3DesignBasisRadialPowerHistogram.....................A-4DesignBasisLocalPowerDistribution(ENCXN-19x9Fuel)..................................A-5DesignBasisLocalPowerDistribution(GESx8Fuel)

XN-NF-86-5

51.0INTRODUCTION

ThisreportpresentstheresultsofExxonNuclearCompany's(ENC's)evaluationofsystemtransienteventsforSusquehannaUnit,2duringCycle2operationwithareloadofENC9x9BWRfuel.Thisevaluationtogetherwithanevaluationofcoretransienteventsdeterminesthenecessarythermalmargin(HCPRlimits)toprotectagainsttheoccurrenceofboilingtransitionduringthemostlimitinganticipatedtransient.Thermalmarginsarecalculatedforoperationwithintheallowedregionsofthepower/flowoperatingmapuptothefullpower/fullflowoperatingcondition.ResultingThermalmarginanalysesarealsopresentedforoperationintheIncreasedCoreFlow(ICF)regionofthepower/flowoperatingmapandforoperationwithaFinalFeedwaterTemperatureReduction(FFTR).AnalysesarealsoreportedforoperationwiththeRecirculationPumpTrip(RPT)outofserviceandwiththeturbinebypasscapabilityinoperable.Anevaluationisalsomadetodemonstratethevesselintegrityforthemostlimitingpressurizationevent.ThebasesfortheseanalyseshavebeenprovidedinReferencel.

l5g XN-NF-86-552.0SUMMARYUsingENCmethodologyandconsideringCycle2fuels,themostlimitingplantsystemtransientwithregardtothermalmarginatratedpowerandflowconditionswasdeterminedtobethegeneratorLoadRejectionWithoutBypass(LRWB).TheMinimumCriticalPowerRatio(HCPR)limitsforpotentiallylimitingplantsystemtransienteventsareshowninTable2.1forcomparison.ThevaluesinTable2.1weredeterminedassumingboundingconditionsintheanalyses.Thesetransientswereevaluatedwithallco-residentfueltypesmodeledandthemostlimitingconditionwasusedtodeterminethereportedMCPRs.TheControlRodWithdrawalError(CRWE)analysisandCycle2HCPRoperatinglimitarereportedinReference2.Maximumsystempressurehasbeencalculatedforthecontainmentisolationevent,whichisarapidclosureofallmainsteamisolationvalves,usingthescenarioasspecifiedbytheASMEPressureVesselCode.ThisanalysisshowsthatduringCycle2thesafetyvalvesofSusquehannaUnit2havesufficientcapacityandperformancetopreventthepressurefromreachingtheestablishedtransientpressuresafetylimitof110%ofdesignpressure(1.1x1250=1375psig).Theanalysisalsoassumedsixsafetyreliefvalvesoutofservice.ThemaximumsystempressurespredictedduringtheeventareshowninTable2.1.ResultsforRPToutof'ervicearereportedinSection3.2.1,andresultsforoperationatICFandFFTRarereportedinSection4.

XN-NF-86-55Table2.1TransientAnalysisResultsatDesignBasisConditions*TransientCPRMCPRENC9x9GEBx8LoadRejectionWithoutBypass0.17/1.230.16/1.22FeedwaterControllerFailureLossofFeedwaterHeating0.15/1.21NA/1.140.14/1.20NA/1.14MaximumPressuresiTransientVesselDomeVesselLowerPlenumSteamLineMSIVClosure130113151305*104%power/100%flow.**BasedonasafetylimitMCPRof1.06.

XN-NF-86-553.0TRANSIENTANALYSISFORTHERMALMARGIN3.1DesinBasisConsistentwiththeFSARplanttransientanalysis,thermalmarginoperatingMCPRlimitsaredeterminedbasedonthe104%power/100%flowoperatingpoint.ThisthermalmarginoperatingMCPRlimitisthenmodifiedasafunctionofpowerandflowasrequiredtoprotectagainstboilingtransitionresultingfromtransientsoccurringfromallowedconditionsonthepower/flowoperatingmap.Theplantconditionsforthe104%power/100%flowpointareasshowninTable3.1.ThemostlimitingpointinCycle2hasbeendeterminedtobeatendoffullpowercapabilitywhencontrolrodsarefullywithdrawnfromthecore.Thethermalmarginlimitestablishedforendoffullpowerconditionsisconservativeforcaseswherecontrolrodsarepartiallyinserted.Follow-ingrequirementsestablishedinthePlant.OperatingLicenseandassociatedTechnicalSpecifications,observanceofaMCPRlimitof1.23for9x9fueland1.22for8x8fuelorgreaterconservativelyprotectsagainstboilingtransi-tionduringanticipatedplantsystemstransientsfromdesignbasisconditionsforSusquehannaUnit2Cycle2.ThecalculationalmodelsusedtodeterminethermalmarginincludeENC'splanttransientandcorethermal-hydrauliccodesasdescribedinprevious(1,4-7)documentation'Fuelpellet-to-cladgapconductancesusedintheanalysesarebasedoncalculationswithRODEX2).Table3.2summarizesthevaluesusedforimportantparameterstoprovideaboundinganalysis.RecirculationPumpTrip(RPT)coastdownwasinputbasedonmeasuredSusquehannaUnit2startuptestdata.Toconfirmtheneutronicsas'requiredbytheSERissuedforthesupplementsofReferenceItheSusquehannasystemtransientmodelwasbenchmarkedtoappropriateSusquehannaUnit2startuptestdata.AlltransientswereanalyzedonaboundingbasisusingtheCOTRANSAhotchanneldeltaCPRmodelasdescribedinReference9.

XN-NF-86-553.2nticiatedTransientsENCconsiderseightcategoriesofpotentialsystemtransientoccurrencesforJetPumpBWRsinXN-NF-79-71('.Thelossoffeedwaterheating(g)transienthasbeenanalyzedonagenericbasisasreportedinReference10.ResultsshownforthistransientarefromtheENCgenericanalysis.Thetwomostlimitingtransientsaredescribedherein.detailtoshowthethermalmarginforCycle2ofSusquehannaUnit2.Thesetransientsare:LoadRejectionWithoutBypass(LRWB)FeedwaterControllerFailure(FWCF)AsummaryofthetransientanalysesisshowninTable3.3.Otherplanttransienteventsareinherentlynonlimitingorclearlyboundedbyoneoftheaboveevents.3.2.1LoadRejectionWithoutBypassThiseventisthemostlimitingoftheclassoftransientscharacterizedbyrapidvesselpressurization.Thegeneratorloadrejectioncausesaturbinecontrolvalvetrip,whichinitiatesareactorscramandRPT.Thecompressionwaveproducedbythefastcontrolvalveclosuretravelsthroughthesteamlinesintothevesselandcreatesthevesselpressurization.Turbinebypassflow,whichcouldmitigatethepressurizationeffect,isnotallowed.TheexcursionofcorepowerduetovoidcollapseisprimarilyterminatedbyreactorscramandvoidgrowthduetoRPT.Figures3.1and3.2depictthetimevarianceofcriticalreactorandplantparametersduringtheloadrejectiontransientcalculationwithboundingassumptions.TheboundingassumptionsareconsistentwithENC'sCOTRANSAcodeuncertaintiesanalysismethodologyasreportedinXN-NF-79-71(P)Rev.2,Supplements1-3andapprovedbyNRC.Theboundingassumptionsinclude:

XN-NF-86-55TechnicalSpecificationminimumcontrolrodspeedTechnicalSpecificationmaximumscramdelaytimeintegralpowerincreasedby10%Atdesignbasisconditions(104%power/100%flow)thisresultsinadeltaCPRof0.17fortheloadrejectionwithoutbypasswhenRPTisoperableforENC9x9fuel.ThecorrespondingdeltaCPRforGE8x8fuelis0.16.Theloadrejectionwasthenanalyzedassumingthesameboundingconditionsbut.withbothRPTand.bypassinoperable.ThisresultedindeltaCPRsof0.31forbothENC9x9andGE8x8fuel.3.2.2FeedwaterControllerFailureFailureofthefeedwatercontrolsystemispostulatedtoleadtoamaximumincreaseinfeedwaterflowintothevessel.Astheexcessivefeedwaterflowsubcoolstherecirculatingwaterreturningtothereactorcore,thecorepowerwillriseandattainanewequilibriumifnootheractionistaken.Eventually,theinventoryofwaterinthedowncomerwillriseuntilthehighlevelvesseltripsettingisexceeded.Toprotectagainstspilloverofsubcooledwatertotheturbine,theturbinetrips,closingtheturbinestopvalvesandinitiatingareactorscram.Thecompressionwavethatiscreated,thoughmitigatedbybypassflow,pressurizesthecoreandcausesapowerexcursion.Thepowerincreaseisterminatedbyreactorscram,RPT,andpressurerelieffromthebypassvalvesopening.TheevaluationofthefloweventatdesignbasisconditionswasperformedwithboundingvaluesandresultedinadeltaCPRof0.15forENC9x9fueland0.14forGE8x8fuel.Figures3.3and3.4presentkeyvariablesforthisfeedwatercontrollerfailureevent.Thiseventwasalsoexaminedforreducedpowerconditionsatfullflow.TheresultsfortheFWCFtransients XN-NF-86-55fromreducedpowerconditionsareshowninTable3.4.ThecalculatedresultsshowthatFWCFdeltaCPRsvarywithdecreasingpoweratfullflowconditions.ThehighestdeltaCPRswerecalculatedatthe40%power/100%flowconditions.Thistransienteventatfullpowerandfullflowconditionswasalsoanalyzedassumingboundingconditionsandfailureofthebypassvalvestoopen.Thisresulted'inadeltaCPRof0.18forENC9x9fueland0.17forGE8x8fuel.3.2.3LossofFeedwaterHeatingThelossoffeedwaterheatingleadstoagradualincreaseinthesubcoolingofthewaterinthereactorlowerplenum.Reactorpowerslowlyrisestothethermalpowermonitorsystemtripsetpoint.Thegradualpowerchangeallowsfuelthermalresponsetomaintainpacewiththeincreaseinneutronflux.ENChasanalyzedthelossoffeedwaterheatingeventonagenericbasisasdescribedinReference10.BasedonthegenericanalysisandtheCycle2safetylimitof1.06,theMCPRlimit.forSusquehannaUnit2Cycle2willbe1.14forboththeENC9x9fuelandtheGE8x8fuelforthelossoffeedwaterheatingevent.Thebypassvalvesdo'otsignificantlyaffectthelossoffeedwater.heatingresults.Thus,thisMCPRlimitisapplicablewhetherthebypassvalvesareoperableornot.3.3CalculationalModelTheplanttransientcodeusedtoevaluatethegeneratorloadrejectionandfeedwaterflowincreasewasENC'scodeCOTRANSA~~.Theaxialone-dimensionalneutronicsmodelpredictedreactorpowershiftstowardthecoremiddleandtopaspressurizationoccurred.Thiswasaccountedforexplicitlyindeterminingthermalmarginchangesinthetransient.Thelossoffeedwaterheatingevent XN-NF-86-55wasevaluatedgenericallybecauserapidpressurizationandvoidcollapsedonotoccurinthisevent.AppendixAoftheSusquehannaUnit1Cycle2analysisdelineatesthechangesmadetoCOTRANSAtomergethePTSBWR3codewiththeCOTRANSAcode,torefinenumericaltechniquesandtoimproveinput.AppendixAofReferen'ce9describestherefinementmadetothehotchannelmodeltocalculatethedeltaCPR'sduringthetransient.AppendixBofReference3delineatestheplantrelatedchangesmadetothesecodesfortheSusquehannaUnits1and2analyses.3.4SafetLimitThesafetylimitistheminimumvalueofthecriticalpowerratio(CPR)atwhichthefuelcouldbeoperatedwheretheexpectednumberofrodsinboilingtransitionwouldnotexceed0.1%ofthefuelrodsinthecore.ThesafetylimitistheHCPRwhichwouldbepermittedtooccurduringthelimitinganticipatedoperationaloccurrenc'e.Thesafetylimitforallfueltypesin'usquehannaUnit2Cycle2wasdeterminedbythemethodologypresentedinReference4tohaveavalueof1.06.TheinputparametersanduncertaintiesusedtoestablishthesafetylimitarepresentedinAppendixAofthisreport.

XN-NF-86-55Table3.1ReactorDesignandPlantCo'nditionsSusquehannaUnit2ReactorThermalPower(104%)TotalCoreFlow(100%)CoreIn-ChannelFlowCoreBypassFlowCoreInletEnthalpyVesselPressuresSteamDomeUpperPlenumCoreLowerPlenumTurbinePressureFeedwater/SteamFlowFeedwaterEnthalpyRecirculationPumpFlow(perpump)3439HWt100.0Hlb/hr89.7Mlb/hr10.3Hlb/hr518.0Btu/ibm1031psia1049psia1058psia1067psia974.7psia14.15Hlb/hr360.8Btu/ibm15.7Hlb/hr 10XN-NF-86-55Table3.2SignificantParameterValuesUsedinAnalysisSusquehannaUnit2HighNeutronFluxTripControlRodInsertionTimeControlRodWorthVoidReactivityFeedbackTimetoDeenergizedPilotScramSolenoidValvesTimetoSenseFastTurbineControlValveClosureTimefromHighNeutronFluxTimetoControlRodNotionTurbineStopValveStrokeTimeTurbineStopValvePositionTripTurbineControlValveStrokeTime(Total)Fuel/CladdingGapConductanceCoreAverage(Constant)Safety/ReliefValvePerformanceSettingsReliefValveCapacityPilotOperatedValveDelay/Stroke125.3%3.5sec/90%insertednominalnominal200msec(maximum)30msec290msec100msec90%open70msec443.8Btu/hr-ft2-FTechnicalSpecifications225.4ibm/sec(1110psig)400/150msec XN-NF-86-55Table3.2SignificantParameterValuesUsedinAnalysis(Cont.)SusquehannaUnit2HSIVStrokeTimeHSIVPositionTripSetpointTurbineBypassValvePerformanceTotalCapacityDelaytoOpening(80%open)FractionofEnergyGeneratedinFuelVesselWaterLevel(aboveSeparatorSkirt)HighLevelTripNormalLowLevel.TripHaximumFeedwaterRunoutFlowThreePumpsRecirculationPumpTripSetpoint3.0sec90%open936.11ibm/sec300msec0.96558.7in36.5in8in4118ibm/sec1170psigVesselPressure 12XN-NF-86-55Table3.2SignificantParameterValuesUsedinAnalysis(Cont.)SusquehannaUnit2ControlCharacteristicsSensorTimeConstantsPressureOthersFeedwaterControlModeFeedwaterMasterControllerProportionalGainResetRateFeedwater100%MismatchWaterLevelErrorSteamFlowEquiv.FlowControlModePressureRegulatorSettings'eadLagGain500msec250msecThree-Element50.0(%/%)(%/ft)1.70(%/sec/ft)48in100%Manual3.0sec7.0sec3.33%/psid 13XN-NF-86-55Table3.3ResultsofSystemPlantTransientAnalysesEventMaximumNeutronFlux%RatedMaximumMaximumCoreAverageSystemHeatFluxPressure%Rated~sia6CPRLoadRejectionWithout8ypass274114.31213.17FeedwaterControllerFailure245114.71180.15MSIVClosurewithFluxScram368130.71330Note:Alleventsareboundingcaseat104%power/100%flow.

14XN-NF-86-55Table3.4FeedwaterControllerFailureAnalysisResultsat100%Flow%PowerDeltaCPRCESx8ENC9x9100.14.15.80.22.2465.23.2540.26.29 30252HEA3.RECVESFLUXRCULATIELSTENFLOWFLOW20124512~g350'8.00.20.50'1'1'1'1'TINE.SEC2.02.22'Figure3.1LoadRejectionWithoutBypass 172.VESELWATLEVEL(TN)12106COlr~<g750)OlEA5VlQJ54cLR500)Ol))250'0.20.50.71'1'1'TINE.SEC1~72'2'2'Figure3.2LoadRejectionWithoutBypass 30252HEAFLUX3.RECRCULATIHFLOW4.VESELSTEFLOW20~15o105012820TINE.SECFigure3.3FeedwaterContro1lerfai1ure28 2.VESELMhTLEVEL(IN)121080rQlQlQla60Qlrt$0I00Ialal40~~N2010p12162024TIME.SEC2836>CIICOCJlICJl4PcJlFigure3.4FeedwaterControllerFailure l'

19XN-NF-86-554.0ANALYSESWITHINCREASEDCOREFLOWICFANDFINALFEEDWATERTEMPERATUREREDUCTIONFFTRAspartoftheSusquehannaUnit2licensinganalysis,ENCevaluatedtransientsforoperationintheIncreasedCoreFlow(ICF)operatingregionupto108%ofratedflow.Transientanalyseswerealsoperformedforafeedwatertemperaturereductionofupto65degreesFatbothnominalflowandincreasedcoreflowconditionsattheendoftheoperatingcycle.This65degreeFtemperaturereductionwasconservativelyheldconstantatallpowerlevelsevaluated.AsummaryofthetransientanalysesisshowninTable4.1.ComparisonoftheresultsinTable2.1and4.1indicatethatICFhadnosignificanteffectontheLRWBdeltaCPRresultsandFFTRconditionslightlyreducedtheimpactofthisdocument.ThecorrespondingmaximumoverpressurizationeventisdiscussedinSection5.0andthepumprun-upanalysisisreportedinSection6.0.TheeffectsofthefinalfeedwatertemperaturereductionwereevaluatedbyanalyzingtheFWCFtransientovertheallowedpowerrangeforbothnominalfeedwatertemperatureanda65degreeFfinalfeedwatertemperaturereduction.Calculationswereperformedforboththe100%coreflowandforthe108%coreflowconditions.TheresultsofthesecalculationsareshowninTable4.2.ThecalculatedFWCFtransientdeltaCPRgenerallyincreaseswithdecreasingpoweratbothflowconditions,andanincreasedMCPRlimitisindicatedforlowpoweroperatingconditions.Thus,forincreasedcoreflowoperation,increasedMCPRlimitsareindicated.Afurther,butsmall,deltaCPRincreaseisgenerallyindicatedtooperatewithreducedfeedwatertemperatureforbothratedcoreflowandincreasedcoreflow.

20XN-NF-86-55Table4.1ResultsofSystemPlantTransientAnalysisatICFandatFFTRLoadRe'ectionWithoutBass104/100(FFTR)104/108104/108(FFTR)MaximumNeutronicFlux(%rated)253241222MinimumCoreAverage(%rated)112.9112.1110.8MaximumSystemPressure(psia)119112101187DeltaCPR0.150.170.15ASMEOverressureMSIVClosuresiVesselDomeVesselLowerPlenumSteamLine104/100(FFTR)104/108104/108(FFTR)1264'12901257127913071274126512961259 21XN-NF-86-55Table4.2FeedwaterControllerFailureDeltaCPRResultsofICFandFFTRAnalysesNominalFeedwaterTem.FFTR~/'E,ENC9x9GE8XSENC9X9100/10080/10065/10040/100100/10880/10865/10840/1080.140.220.230.260.150.200.230.270.150.240.250.290.160.220.250.300.160.200.240.260.160.200.240.260.170.220.260.290.170.220.260.30*65'FreductioninFeedwaterTemperature.

lI 22XN-NF-86-555.0MAXIMUMOVERPRESSURIZATIONMaximumsystempressurehasbeencalculatedforthecontainmentisolationevent(rapidclosureofallmainsteamisolationvalves)withanadversescenarioasspecifiedbytheASHEPressureVesselCode.ThisanalysisshowedthatthesafetyvalvesofSusquehannaUnit2havesufficientcapacityandperformancetopreventpressurefromreachingtheestablishedtransientpressuresafetylimitof110%ofthedesignpressure.ThemaximumsystempressurespredictedduringtheeventareshowninTable2.1.Thisanalysisalsoassumedsixsafetyreliefvalvesoutofservice.5.1DesinBasisThereactorconditionsusedintheevaluationofthemaximumpressurizationeventarethoseshowninTable3.1.Themostcriticalactivecomponent(scramonHSIVclosure)wasassumedtofailduringthetransient.ThecalculationwasperformedwithENC'sadvancedplantsimulatorcodeCOTRANSA,whichincludesanaxialone-dimensionalneutronicsmodel.5.2PressurizationTransientsENChasevaluatedseveralpressurizationeventsandhasdeterminedthatclosureofallHainSteamIsolationValves(MSIVs)withoutdirectscramisthemostlimiting.ThoughtheclosurerateoftheHSIVsissubstantiallyslowerthantheturbinestopvalvesorturbinecontrolvalves,thecompressibilityoftheadditionalfluidinthesteamlinescausestheseverityofthesefasterclosurestobeless.Essentially,therateofsteamvelocityreductionisconcentratedtowardtheendofthevalvestroke,generatingasubstantialcompressionwave.Oncethecontainmentisisolatedthesubsequentcorepowerproductionmustbeabsorbedinasmallervolumethanifaturbineisolationhadoccurred.Calculationshavedeterminedthattheoverallresultistocauseisolation(MSIVclosures)tobemorelimitingforsystempressurethanturbineisolations.

23XN-NF-86-555.3ClosureofAllMainSteamIsolationValvesThiscalculationassumedthatsixreliefvalveswereoutofserviceandthatallfoursteamisolationvalveswereisolatedatthecontainmentboundarywithin3seconds.Atabout5.5seconds,thereactorscramisinitiatedbyreaching'thehighfluxtripsetpoints.SincescramperformancewasdegradedtoitsTechnicalSpecificationlimit,effectivepowershutdownisdelayeduntilafter7.1seconds.Substantialthermalpowerproductionenhancespressurization.Pressuresreachtherecirculationpumptripsetpoint(1170psig)beforethepressurizationhasbeenreversed.Lossofcoolantflowleadstoenhancedsteamproductionaslesssubcooledwaterisavailableto'absorbcorethermalpower.Themaximumpressurecalculatedinthesteamlineswas1305psigoccurringnearthevesselatabout10.1seconds.Themaximumvesselpressurewas1315psigoccurringinthelowerplenumatabout10.0seconds.TheanalysiswasrepeatedforICFandFFTRconditionsandtheresultsaresummarizedinTable4.1.CompaisonoftheresultsinTable2.1andTable4.1showthatthedesignbasisconditionsaremorelimitingthanICForFFTRconditions.Atabout5.5seconds,thereactorscramisinitiatedbyreachingthehighfluxtripsetpoints.SincescramperformancewasdegradedtoitsTechnicalSpecificationlimit,effectivepowershutdownisdelayeduntilafter6.5seconds.Substantialthermalpowerproductionenhancespressuriza-tion.Pressuresreachtherecirculationpumptripsetpoint(1170psig)beforethepressurizationhasbeenreversed.Lossofcoolantflowleadstoenhancedsteamproductionaslesssubcooledwaterisavailabletoabsorbcorethermalpower.Themaximumpressurecalculatedinthesteamlineswas1296psigoccurringnearthevesselatabout10.2seconds.Themaximumvesselpressurewas1307psigoccurringinthelowerplenumatabout9.8seconds.

XN-NF-86-556.0RECIRCULATIONPUMPRUN-UPAnalysisofpumprun-upeventsforoperationatlessthanratedrecirculationpumpcapacitydemonstratestheneedforanaugmentationofthefullflowHCPRoperatinglimitforlowerflowconditions.Thisisduetothepotentialforlargereactorpowerincreasesshouldanuncontrolledpumpflowincreaseoccur.Thissectiondiscussespumpexcursionswhentheplantisinmanualflowcontroloperationmode.Basedontheresultsobtainedfrompreviousanalyseswhichshowedtwopumpexcursionswerethelimitingpumprun-upevent,onlytwopumpexcursionsareevaluatedforSusquehannaUnit2Cycle2.TheseresultsindicatethatMCPRwoulddecreasebelowthesafetylimitifthefullflowreferenceMCPRwasobservedatinitialconditions.Thus,anaugmentedHCPRisneededforpartialflowoperationtoprotectthetwopumpexcursionevent.TheevaluationofthetworecirculationpumpflowexcursionforSusquehannaUnit2showedthatestablishmentofHCPRlimitsforthiseventwhichpreventsboilingtransitionwillalsoboundsinglepumprunups.Theanalysisofthetwopumpflowexcursionindicatesthatthelimitingeventscenarioisagradualquasi-steadyrun-upduetotheinletenthalpylagassociatedwithamorerapidrun-up.TheSusquehannaUnit2Cycle2analysisconservativelyassumedtherun-upeventinitiatedat57%power/40%flowandreached111%ratedpowerat110%ratedflow.110%flowisconsistentwithincreasedcoreflowanalysis;ThispowertoflowrelationshipboundsthatcalculatedbyXTGBWRfortheconstantXenonassumption.Theresultsofthetwopumprun-upanalysesformanual,flowcontrolarepresentedinFigure6.1.ThecyclespecificHCPRlimitforSusquehannaUnit2Cycle2shallbethemaximumofthereducedflowMCPRoperatinglimitandthefullflowHCPRoperatinglimit.

1.4R1.3KCl1.21.11.04Figure6.1TotalCoreRecirculatingFlow(IRated)ReducedFlowMdPROperatingLimitl,OCITlICX)ChICJlCJl 26XN-NF-86-5

57.0REFERENCES

2.3.5.6.7.8.9.10.R.H.Kelley,"ExxonNuclearPlantTransientMethodologyforBoilingWRt,"X~,R1*12(ppid),ENuclearCo.,Inc.,Richland,WA99352,November1981.T.H.Keheley,"SusquehannaUnit2Cycle2ReloadAnalysis,DesignandSafetyAnalyses,"XN-NF-86-60,ExxonNuclearCo.,Inc.,Richland,WA99352,April1986.T.H.Keheley,"SusquehannaUnit1Cycle2PlantTransientAnalyses,"XN-NF-84-118includingSupplement1,ExxonNuclearCompany,Richland,WA99352,December1984.T.L.KrysinskiandJ.C.Chandler,"ExxonNuclearMethodologyforBoilingWaterReactors;THERMEXThermalLimitsMethodology;SummaryPIi,"~,EE,R11(,ENIC.,Inc.,Richland,WA99352,April1981.T.W.Patten,"ExxonNuclearCriticalPowerMethodologyforBoilingWR,"X~,11,ENI2Richland,WA99352,November1979.R.H.Kelley,"DresdenUnit3Cycle8PlantTransientAnalysis2,"('--,III,ENI.,I.,Rihld,IIA99352,December1981.R.H.KelleyandN.F.Fausz,"PlantTransientAnalysisforDresden2,1,"~X---,(21.,1.,(tihid,llA99352,October1982.K.R.Merckx,"RODEX2FuelRodMechanicalResponseEvaluationModel,"~X---,RI1,EIII.,I.,IWhld,IIA99352,March1984.T.H.Keheley,"SusquehannaUnit1Cycle3PlantTransientAnalysis,"XN-NF-85-130,ExxonNuclearCompany,Richland,WA99352,November1985.R.G.Grummer,"AGenericLossofFeedwaterHeatingTransientForW<<,"~X-->>,dI,,Ihid,WA99352,February1986.

E A-IXN-NF-86-55APPENDIXAHCPRSAFETYLIHITA.lINTRODUCTIONTheHCPRfuelcladdingintegritysafetylimitwascalculatedusingthemethodologyanduncertaintiesdescribedinReferenceA.l.Inthismethodology,aHonteCarloprocedureisusedtoevaluateplantmeasurementandpowerpredictionsuncertaintiessuchthatduringsustainedoperationattheHCPRCladdingIntegritySafetyLimit,atleast99.9%ofthefuelrodsinthecorewouldbeexpectedtoavoidboilingtransition.Thisappendixdescribesthecalculationandpresentstheanalyticalresults A-2XN-NF-86-55A.2CONCLUSIONSDuringsustainedoperationataHCPRof1.06withthedesignbasispowerdistributiondescribedbelow,atleast99.9%ofthefuelrodsinthecoreareexpectedtoavoidboilingtransitionataconfidencelevelof95%.

A-3XN-NF-86-55'.3DESIGNBASISPOWERDISTRIBUTIONPredictedpowerdistributionswereextractedfromthefuelmanagementanalysisforSusquehannaUnit2Cycle2.Theseradialpowerdistributionswereevaluatedforperformanceasthedesignbasisradialpowermap,andthedistributionat10,500MWD/HTcycleexposurewasselectedasthemostsevereexpecteddistributionforthecycle.ThedistributionwasskewedtowardhigherpowerfactorsbytheadditionofbundleswitharadialpeakingfactorapproximatinganoperatingHCPRlevelof1.26atfullpower.TheresultingdesignbasisradialpowerdistributionisshowninFigureA.3-1.ThefuelmanagementanalysisindicatedthatthemaximumpowerENCbundleinthecoreatthisstatepointwaspredictedtobeoperatingatanexposurelevelof12,600HWD/HT,soalocalpowerdistributiontypicalofanodalexposureofl5,000MWD/MT'asselectedasthedesignbasislocalpowerdistribution.ThisdistributionisshowninFigureA.3-2.Aboundinglyflatlocalpowerdistributionwasselectedfortheco-residentG.E.Fuel.ThisdistributionisshowninFigureA.3-3.Becausethepredictedpowerdistributionsduringthecyclewerenotallcharacterizedbybottompeakedaxialdistributions,representativesafetylimitevaluationswereperformedatseveralrepresentativecycleburnupstatepointsthroughoutthecycle,includingallpointsatwhichthepowerwasskewedtowardtheupperhalfofthecore.TheseanalysesconfirmedthethatmostseverepowerdistributionconditionswerethosewhicharepredictedtoexistattheendofCycle2.The1.06safetylimitwasconfirmedatallthepointsevaluated.

90807060V)SOC)403020100.20.40.60.81.2RRDIRLPERKINGF'RCTORFigureA.3-lDesignBasisRadialPowerHistogram A-5XN-NF-86-55:0.97:1.01:0.97:1.04:1.04:1.05:0.97:1.02:0.97:1.01:0.94:0.97:1.07:1.06:0.95:1.00:0.95:1.020.97:0.99:1.04:1.05:1.05:1.02:1.06:1.00:0.971,04:0.93:1.05:1.01:0.97:0.00:1.02:0'5:1.05:1.03:1.05:1.03:1.00:0:00:0.97:1.05:1.06:1.04:1.04:0.94:1.04:1.00:1.00:1.01:1.05:1.07:1.04::0'7:0.98:0.90:1.04:1.03:1.05:1.04:0.97:0.97::0.91:0.94:0.98:0.94:1.05:0.93:0.99:0.94:1.01:0.88:0.91:0.97:1.04:1.03:1.04:0'7:1.01:0.97:FiaureA.3-2DESIGNBASISLOCALPOWERDISTRIBUTIONENCXN-19X9FUEL*Rodadjacenttocontrolbladecornerlocation A-6XN-Nf-86-551.03:1.00:0.99:0,99:0.99:0.99:1.00:1.031.00:0.99:1.03:1.02:0.99:0.99:0,97:1.000.99:1.03:0.91:1'2:1,01:0.98:0.99:0.990.991.031.020.00:1.02:1.01:0.99:0.990.99:1.02:1.01:0.91:0.00:1.02:1.02:0.9900.99:0.99:1.02:1.01:1.02:0.91:1.03:0.990~~~41.00:0.970.99:1.02:1.03:1.03:0.99:1.0001.03:1.00:0.99:0.99:0.99:0.99:1.00:1.03~*FigureA.3-3DESIGNBASISLOCALPOWERDISTRIBUTIONG.E.8X8FUEL*Rodadjacenttocontrolbladecornerlocation A-7XN-NF-86-55A.4CALCULATIONOFTHENUHBEROFRODSINBOILINGTRANSITIONTheSAFTLIHcomputercodewasusedtoanalyzethenumberoffuelrodsinboilingtransition.TheXN-3correlationwasusedtopredictcriticalheatfluxphenomena.FivehundredHonteCarlotrialswereperformedtosupporttheHCPRsafetylimit.Non-parametrictolerancelimitswereusedinlieuofPearsoncurvefitting.TheuncertaintiesusedintheanalysisfornormalconditionswerethoseidentifiedinReferenceA-1.Atleast99.9%ofthefuelrodsinthecorewereexpectedtoavoidboilingtransitionwithaconfidencelevelof95%.'

A-8XN-NF-86-55A.5A-l.A-2.A-3.REFERENCES"ExxonNuclearCriticalPowerMethodologyforBoilingWaterR",R111,~X--,XN1CPRichland,WA(November1983)."TRXN-1111CExxonNuclearCompany,Richland,WA(March1981).PaulN.Somerville,"TablesforObtainingNon-ParametricToleranceLimits",AnnalsofMathematicalStatistics,Vol.29,No.2(June1958),pp.599-601.

XN-NF-86-55IssueDate:5/15/86SUS(UEHANNAUNIT2CYCLE2PLANTTRANSIENTANALYSISDistributionD.J.J.C.R.E.S.F.R.G.K.D.S.E.T.H.J.E.T.L.J.N.L.A.T.W.G.L.H.G.D.R.G.N.H.E.BraunChandlerCollinghamGainesGrummerHartleyJensenKeheleyKrajicekKrysinskiMorganNielsonPattenRitterShaw/PP&L(40)SwopeWardWilliamsonDocumentControl(5)

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