ML17212A709
| ML17212A709 | |
| Person / Time | |
|---|---|
| Site: | Saint Lucie  |
| Issue date: | 09/04/1981 |
| From: | UHRIG R E FLORIDA POWER & LIGHT CO. |
| To: | CLARK R A Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML17212A710 | List: |
| References | |
| L-81-388, NUDOCS 8109100207 | |
| Download: ML17212A709 (52) | |
Text
REGULATORNFORMATIONDISTRIBUTIONSTKM(RIDS)ACCESSIONNBR:8109100207DOC~DATE':61/09/04NOTARIZEDINOFACILt;50-335St,LUciePlantEUnit1<FloridaPower8LightCo.AUTH',NAME'UTHORAFFILIATIONUHRIGgR,E,Flor,ida-Power8LightCo,RECIP~NAMElRECIPIENTAFFILSATION-CLARiX"PR~ADOperating,ReactorsBranch3
SUBJECT:
ApplicationforamendtoLicenseDPR-67submittedasresponsetoNRC810728inforequest8proposedamendstoTe'chSpecsreborationcontrolimoderatortempcoefficientireactorcoolantpumps8borondilution8,addition.'ISTRIBUTIONCODE;:AOOIS,.COPIESRECEEVED:l.iTR+ENCL+SIZE'::'lITLEt:-GeneralDistributionforafter>>Issuance~ofOperatingLiicenseiVOTES:OOCKEll'"005000335RECIPlKNTIDCODE/NAMEIACT'ION:"ORB03BC!04"INTKRNALl,D/DIRPHU4lFACOBI8Ei06'RASSESS'R10.L01COPIESLTTRENCL>>13131221011RECIPIENTIOCODE/NAMEDIRiDIVOFLICOELD11RADASMTBRCOPIESLlTTRiENCLI11101KXTERNALi:ACRSNRCPDRNTIS0902i1616LPDR11,NSIC1103051111gp1gqgSETOTALNUMBEROFCOPIESREQUIRED:LTTR41ENCL'l39 llrtkttIII
~+~wc'efP.o.BOX629100,MIAMI,FL33162fkvv<4%FLORIDAPOWER&LIGHTCOMPANYSeptember4,1981L-81-388OfficeofNuclearReactorRegulationU.S.NuclearRegulatoryCommissionWashington,D.C.20555Attention:Mr.RobertA.Clark,ChiefOperatingReactorsBranch$/3
Subject:
St.LucieUnit1DocketNo.50-335StretchPowerProposedAmendmentcS~POg1981IQi%a+~~95
References:
1.Letter,R.A.ClarktoR.E.Uhrig,7/28/812.Letter,R.E.UhrigtoD.G.Eisenhut,L-80-381,11/10/803.Letter,R.E.UhrigtoD.G.Eisenhut,L-81-3067/23/81
DearMr.Clark:
InresponsetotheinformationrequestofyourReference1letter,wehaveenclosedresponsestoyourten(10)questionsinAttachment1tothisletter.InordertoclarifytherelationshipofourReference3submittal(ShutdownMarginandMTCchanges)toourReference2submittal(StretchPower)wehavedescribedtheproposedamendmenttoStretchbelowandhaveenclosedallthepertinentamendedTechnicalSepcificationpagesinAttachment2tothisletter.Paes3/0l-lR3/01-2R3/01-5R3/00-1RB3/0l-lTherequirementsforshutdownmarginwereincreased,andashutdownmargincalculationchangewasadded.Therequirementsforpartloopoperationweresimplifiedandtheshutdownmarginrequirementsdecreasedslightly.Therequirementforthemoderatortemperaturecoefficient(MTC)atratedthermalpowerwaschanged.TheproposedamendmenttoStretchhasbeenpreviouslyreviewedandapprovedbytheSt.LucieFacilityReviewGroupandtheFloridaPower*LightCompanyNuclearReviewBoard.SpecificallythenewrequirementsforshutdownmarginandMTCareboundedinalltheotheranalyseswhichusethemoreconservativevaluesof0.3%Ijhk/kand-2.5x10-<hk/k/OF,respectively.Furtherwewereabletosimplifytherequirementsforpartloopoperation8109100207Bi0904PDRADOCK05000335PORPEOPLE...SERVINGPEOPLE 1'.'-P./CASA~~>>'i:~a','1gf.".J3f;~~tL1\I)l'AJJ4~'VJ<)I~I.)~,-~>'.~'~Ic~J*
becausetherequiredreactorcoolantpump(RCP)tripcausesthefullloopandpartloopeventstobehavewithnosignificantdifferencesinresults.T-WehaveenclosedthesafetyevaluationsfortheExcessLoad(EL)andtheSteamGeneratorTubeRupture(SGTR)eventsinAttachment3tothis.letter.TheseeventsalongwiththeSteamLineRupture(SLB)event(submittedthroughReference3)werereanalyzedforCycle5toincludetheeffectofNRCmandatedTMI-2relatedoperationalanddesignchanges,i.e.automaticinitiationofauxilliaryfeedwaterflowandmanual,tripofallfourRCPs.Otheranalysesarenotsignificantlyaffectedbythesechanges.Thesethreeeventsafetyevaluations(SLB,ELandSGTR)shouldreplacethosesubmittedthroughReference2.NonewTechnicalSpecificationchangestoStretch,otherthanthoseinAttachment2tothisletter,ariseasaresultofthereanalysisoftheseevents.AlsotheresponsestoquestionsonSLBandSGTR(Questions7,8,and9)inAttachment1tothisletterarebasedontheserevisedanalysesinAttachment3andReference3.VerytyoursRobertE.UhrigVicePresidentAdvancedSystems2Technologycc:Mr.J.P.O'Reilly,Director,RegionIIMr.HaroldF.Reis,Esquire ATTACHMENTI 4guestion1Theinverseboron'worthvalueslistedinTable7.1.1-1areincreasedforallmodesofoperation.Increasedinverseboronworthmeansthatmoreboronmustbedilutedforagivenchangeinreactivity,whichislessconservative.Oescribethebasesforandjustifythenewvaluesofinverseboronworthforeachmodeofoperation.~ResenseThenewinverseboronworthsreportedinTable7.1.1-1arebasedonexplicitdiffusiontheoryca1culationsofreactivitywhichspanthe'powerlevelsandtemperaturerangeallowedwithineachoperatingmode.Theseinverseboronworthsareconsistentwiththecriticalboroncon-centrati'onsshowninTable7.1,1-1.Althoughthei'nverseboronworthshaveincreasedwhencomparedtotheReferenceCyclevalues,thenewvaluesreportedinTab'le7,1.1-1aresttlll.owerthantheexplicitCycle4cal-culatedvalues.Sincethenewvaluesboundtheexplicitcalculatedvalues,theirusejnthe,Cycle4borondilutioneventisjustified.
Ouestion211TherefuelingshutdownmarginlistedinTable7.1.1-1hasbeenchangedfrom9.45Ãsubcriticalto6.28Ãsubcritial,whichreducesthedilutiontimetoreachcriticality.Whatistheboronconcentrationthatcorrespondswiththenewshutdownmargin?Comparethiswiththepreviousrefuelingboronconcentration.~ResenseThecriticalboronconcentrationforCycle4is1280PPM,incomparisontothereferencecyclevalueof1200PPH.Theinitialboronconcentra-tionforbothCycle4andthereferencecycleistheminimumrequiredTechnicalSpecificationboronconcentrationof1720PPM.
~Iuestion3TheresultsoftheborondilutioneventsshowninTable7.1.1-2listthetimetoloseprescribedshutdownmarginforeachmode.PleasebeawarethatSPRSection15.4.6specifiesminimumtimesfromwhenanalarmmakestheoperatorawareofanunplanneddilutioneventasacceptancecriteria.Whatalarmsmakestheoperatorawareofborondilutionineachmode?Whatarethesetpoints,timedelays,anderrorsassociatedwithdetectionandalarmsystems,andhowaretheseaccountedforinthetimefortheoperatortoreacttoaborondilutionevent?ResponseTheindicatorsthatareavailabletotheoperatorfordeterminingifanunplanneddilutionisinprogressare:1)thestartupfluxchannels,2)thelowlevelalarmontheVolumeControlTank,3)theboronometerand4periodicsampling.Dependingonthemodeofoperationandontherateofdilution,oneoralloftheseindicatorswouldalerttheoperatorthataninadvertentdilutionisinprogress.Theleastamountoftimetolose'rescribedshutdownmarginisinMode5.TheprimaryindicatorinMode5is.thestartup'luxchannels.TwostartupfluxchannelsarerequiredtobeoperableinMode5bytheTechnicalSpecifications.Procedureswillbedevelopedwhichwillrequiretheoperatorto:a)b)ObservethecountrateuponenteringMode5,Periodicallycheckthatthecountratehasnotincreased(theintervalisdependentonthenumberofchargingpumpsinoperationandtheliquidvolume.intheRCS),c)Takecorrectiveactionwheneverthecountrateexceedsaprescribedvalue(i.e.,effectivelyanalarmlimit)TheseactionsaresufficientbecauseinNode5theboronconcentrationisnormallyhigherthanrequiredbyTechnicalSpecications.ThishigherconcentrationresultsfromnotdilutingfromthehigherrequiredconcentrationsforNodes4and6.ItshouldalsobenotedthatpastexperienceatSt.Luciehasverifiedthequalityofoperatortrainingandoperatoractionduringaborondilutionevent,LER335-80-71reportedaborondilutionatpowerwhichwascorrectlycontrolledbytheSt.Lucieoperators.
Isuestion4TheparametersshowninTable7.1.4-4arestatedtomaximizethecalculatedpeakRCSpressureforalossofloadevent.However,theinitialpressureof2200psiaislowerthanthevaluepreviouslyutilized(2250psia)tomaximizetheRCSpeakpressure.Providefurtherdiscussiononwhyalowerinitialpressureisconservative,orevaluatetheeffectsofahigherinitialpressureonthecal-culatedpeakpressure.~ResenseTheuseofthelowestinitialRCSpressureisconservativesincethisdelaysthetimeofHighPressurizerPressure(HPP)trip.DelayingthetimeofHPPtripmaximizestherateofpressurein-creaseatthetimeoftripandtherebymaximizesthepressureover--shootafterreactortrip.Thisresultsin.thepeakRCSpressureduringtheevent.Therefore,thelowestRCSpressureof2200psiaallowedbytheTechnicalSpecificationwasconservativelyassumedtodetermine.thepeakpressureduringtheLossofLoadev'ent; guestion5TheLossofCoolantFlowanalysishasseveralareaswhicharenotfullyaddressedandmaybenon-conservative.Pleasediscussthefollowing:1)Theinitialcorepowerisat100%ratherthan102ÃasrequiredbySRPSection15.3.1;2)Theassumedscramcharacteristicsdonotdiscussifthemostreactiverodisheldoutofthecore;3)t<obasesareprovidedtojustifythepumpcoastdowncurve.~Resonse1)Reference1documentsC-E'sstatisticalcombinationofuncertaintymethodology.ThemethodsandinitialconditionsusedintheLossofFloweventareconsisteqtwith/hosereportedingeferencq.I,.Inparticular,theuncertaintyininitialpowerleveiisincludedas.,a-t'erminthetotaluncertainty.Therefore,aninitialpowerlevelof100wasassumedintheLossofFloweventanalysis.2)The,:;,-scramworthusedintheanalysiswascalculatedwiththemost",reactiverodheldoutofthecore.3)The'-pumpcoastdowncurveusedintheLossofFloweventiscalculatedusingthecodeCOAST(Reference2).Thiscoastdowncurveis'identicaltotheone.usedandacceptedbytheNRCintheFSARandpreviousreloadsafetyanalysis..References'1.CEH-12(F)-'P,"StatisticalCombinationofUncertainties,Part.3,"March1980.2.CENPD-98,"COASTCodeDescription,"May1973.
1t(}uestion6TheLossofNon-EmergencyACPowereventutilizesthesameDNBanalysisusedfortheLossofCoolantFlowtransient(7.2.2).Theitemsinquestion5mustbesatisfactorilyresolvedbeforetheanalysisforLossofACPowerwillbeconsideredvalid.1n~addition,thevalueof1.15usedforthedopplercoefficientmultipliermustbejustifiedasconservativeconsideringthepreviousvalueof0.85usedintheFSAR.~ResenseAdopplercoeff'icientmultiplierof1.15wasusedintheanalysissincethisresultsinaslowerpowerrampdownfollowingreactortrip.Thisincreasestheresidualheatthatmustberemovedduringplantcooldownandincreasesthesteamreleases.Highersteamreleasesduringthecooldownincreasesthesiteboundarydoses.Thus,itisconservativetouseadopplercoefficientmultiplierof1.15.
uestion7providejustificationforthevaluesoftheinitialcorecoolanttemperatureandpressuretoshowthattheyareconservativefortheSteamLineBreakanalysis.Also,discussthebasisfortheinitial,coreflowratesassumedandthedelayedneutronfraction.~ResenseThemaximuminitialcorecoolanttemperatureallowedbytheTechnicalSpecificationwasusedintheanalysis.Thiscausesthegreatestcoolanttemperaturedecreaseduringtheevent,whichresultsinthemaximumpositivereactivityinsertionduetomoderatorfeedback..ThegreatestamountofpositivereactivityinsertionenhancesthepotentialforReturn-to-Criticality(R-T-C)andReturn-to-Power(R-T-P).TheSLBeventinitiatedwiththe.maximuminitialRCSpressuredelaystheinitiationofSafetyInjectionActuationSignal(SIAS).Thisresultsintheleastamountofnegativereactivityaddedtothecoreduetoboroninjected,viathe,HighPressureSafetyInjection(HPSI)pumps,ThesmalleramountofnegativereactivityinsertedenhancesthepotentialforR>>T-CandR-T-P.0Themaximumvalueforthedelayedneutronfractionatendofcyclewasassumedintheanalysis.ThemaximumvalueincreasesthesubcriticalmultiplicationandthusenhancesthepotentialforR-T-P.Theinitialcoremassflowrateassumedintheanalysisisconsistentwith'heminimumguaranteedTechnicalSpecificationvesselflowrateof370,000GPN.
uestion8NoDNBanalysiswasperformeddespitetherapidsystemdepressurization.WhataretheminimumDNBratioscalculated?~ResenseTheminimumDNBRduringthetransientwascalculatedusingtheMacBethrodclustercorrelation(Reference1)withtheLeenon-uniformheatfluxcorrectionfactor(Reference2).Theminimum.transientDNBRfortheHFPSLBeventoccursat145secondsandisequalto1.27.References1..R.V.MacBeth,"AnappraisalofForcedConvectionBurn-OutData",Proc.Instn.Mech.Engrs.,1965-66,Vol.180,Pt.3C,pp.37-50.2.D.H.Lee,"AnExperimentalInvestigationofForcedConvectionBurnoutinHighPressureMater;PartIV,LargeDiameterTubesatAbout1600psia",AEBl-R479,November,1966.
uestion9',TheSteamGeneratorTubeRuptureEventshows.arapiddropinRCSpressureandtemperatureatabout600secondsinFigures7.3.3-3and7.3.3-4.Pleaseprovidefigureswithfinerdetailinthisregion(approximately550'o650seconds)andevaluatethechancesofandeffectsofsteambubbleformationinthevesselheadorhotlegs.Theeffectsofsteambubbleformationonthe"radiologicalevaluationsshouldalsobeconsidered.~ResenseAsrequested,Figures1and2presentinfinerdetailtheRCSpressureandtemperaturefrom550secondsto650seconds.Thereference,preparedinresponsetopreviousNRCquestionsonupperheadvoiding,confirmsthatthemodelbeing-usedinthisanalysisadequate1yaddressestheeffectsofsteambubbl'eformationinthevesselupperheadandhot'egsduringaSteamGeneratorTubeRuptureevent.Inaddition,the.the.referencecontainsanevaluationoftheradiologicaldoseduetosteambubbleformation.'eference:LetterfromRobertE.UhrigtoDarrellG.Eisenhut,"St.LucieUnit1DocketNo.50-335Natural'irculationCooldown",L-81-43,February9,1981; guestion10TheSeizedRotoranalysisdoesnotincludeacalculatedDNB,MDNBR{accountingforstatisticaluncertaintieswiththenewC-Emethodology)orapeakcladtemperatureasrequiredbySRPSection15.3.3Pleaseprovidethisinformationandconfirmthatthemostreactiverodwasassumedstuckoutofthecore.~ResonseTheminimumONBRforaSeizedRotoreventinitiatedfromTechnicalSpecificationDNBLimitingConditionsforOperationis1.025~AsstatedinSection7.3.4,thepredictednumberoffuelpinfailuresisnotbasedonasingleHDNBRvaluebutisca]'c61atedthroughadistributionofthefractionofpinswithapar'ticularONBRasafunctionofDNBR.Thisdistributionisthen,:,convolutedwithaprobabilityofburnoutvs.DNBRtoobtaintheamount,offuelfailure.Thescramworthusedinanalyzingthis.event'~wascalculatedassumingthatthemostreactiverodisstuckoutofthe,-.core.
II~~I IOXIOTONINCH7Xi0INCHES'ICaICEUEEEL0ESiIIERCO.IIJWIIIUSA461320~k'~I~II!J:IL'Ilijl!IIIijT(IiI~~~I.IlliI;II~ITIi~IIII,IIJ~iljI~IIilI~I~I~~I~~~ililIlt(IIsI~II~Il,:tI~~III~III'I/ISSIl,'I~(Ij;!LI'II~~i~~~~'IlIjlI~~II~l::il!!:ijI(lIIslIii(I~Ili'IP(II~i(II~II~l(ll:I.'.LLhajjjij~II',ililliI~~IiW illX10TO'INCH1XlsiINCIIESfE-~ILKEUFfiLAESSEACO,assisisasisola461320.~iili~IIi'f'.'ij~iI~IIII~i~sl~~I~I!;aia~I~Isi~~~~sl~~i:.~~iIiI~at't,.l~f,Ii~~I)iI~~~7~,lt'jiilII~~~~~~~II~~Is~IEEii~jsl,,Ia~iI~iiiiiis.IREI~I~tlI~$$URii~~I~siil~I~IIaI~I~o4~IIaa'i~~Ii~,~~~~~~~~~~Ii!II~s~~~I~~a~~sIa~I~JI~>>ais.iI~II~I~ala~~IsLII'IIII~~~~~i~.iI:i'IIs:.i'jI,i~I.IIIili.igh.~~III.~~I~~'i:II~I;i~Il~sifl~~Iifljla,IaIII~IaI~~~I~IiIa~I~~~Ii~t~Ii~LaIisisal~~I~~IIa~aliI'lIa~ls ATTACHMENT2 ATTACHMENT3 7.1.3ExcessLoadEventTheExcessLoadEventwasreanalyzedtodeterminethattheDNBRandCTMdesignlimitsarenotexceededduringCycle5.TheanalysesincludedtheeffectsofmanuallytrippingtheRCP'sonSIASduetolowpressurizerpressureandtheinitiationofauxiliaryfeedwaterflow180secondsafterreactortrip.TheHighPowerLeveland.ThermalMargin/LowPressure{TM/LP)tripsprovideprimaryprotectiontopreventexceedingtheDNBRlimitduringthefullpowerExcessLoadevent.Additionalprotectionisprovidedbyothertripsignals.includinghighrateofchangeofpower,lowsteamgeneratorwaterlevel,andlowsteamgeneratorpressure.Theapproachtothe.CTMlimitsisterminatedbyeithertheAxialFluxOffsettrip,theDNBrelatedtriportheHighPowerLeveltrip.In,thisanalysis,creditis,takenonlyfortheactionoftheHighPowerLeveltripinthedeterminationoftheminimumtransientDNBRandmaximumCTM.ForthezeropowerExcessLoadtransient,protectionisprovidedbytheVariableHighPowerLeveltriptopreventviolationoftheDNBRandCTMliririts.AspresentedintheFSAR,themostlimitingloadincreaseeventsatfullpowerandhot.Rempowerconditions"occur'orthe.completeopeningofthe.steamdumpandbypass'valves.Ofthesetwoevents,thefullpowercaseisthe'morelimiting{i.e.,approachesclosertotheacceptableDNBRandCTMlimits)case.Forconservatismintheanalyses,auxiliaryfeedwaterflowratecorrespondingto15.3%offullpowermainfeedwaterflow(i.e.,7.66Koffullpowermainfeedwaterflowpergenerator)wasassumed.Theadditionoftheauxiliaryfeedwatertoeachsteamgeneratorwasinitiatedat180seconds,afterreactortrip.TheadditionofauxiliaryfeedwaterenhancesthecooldownoftheRCSandthepotentialforareturn-to-power{R-T-P)orcriticalityarisingfromreactivityfeedbackmechanisms.>TheExcessLoadeventatfullpowerwasinitiatedattheconditionsgiveninTable7.1.3-.1.A,ModeratorTemperatureCoefficientof-2.5x10-"ap/oFwasassumedintheanalysis.ThisMTC,inconjunctionwiththedecreasingcoolantinlettemperature,enhancestherateofincreaseinthecoreheatfluxatthetfmeofreactortrip.5minimumFuelTemperatureCoefficient(FTC),correspondingtobeginningofcycleconditionswithanuncertaintyof155,wasusedintheanalysissincethisFTCresultsintheleastamountofnegativereactivityadditiontomitigatethetransientincreaseincoreheatflux.TheminimumCEAworthassumedtobeavailableforshutdownatthetjmeofreactortripforfullpoweroperationis4.3Xap.Theanalysisconservativelyassumedthattheworthofboroninjectedbythesafetyinjectionsystemis-1.0Ãapper105PPM.ThepressurizerpressurecontrolsystemwasassumedtobeinoperablebecausethisminimizestheRCSpressureduringtheeventandthereforereducestheca1culatedDNBR.Allothercontrolsystemswereassumedtobeinmanualmodeofoperationandhavenosignificantimpactontheresultsforthisevent.
TheFullPowerExcessLoadeventresultsinaHighPowerLeveltripat8.4seconds.TheminimumDNBRcalculatedfortheeventattheconditionsspeci-.fiedinTable7.1.3-1is1.29comparedtothedesignlimitof1.23.Themaximum.locallinearheatgenerationratefortheeventis18.3KW/ft.FortheExcessLoadeventinitiatedfromHFPconditions,SIASisgenerated't54.0seconds.UpongenerationofanSIAS,theRCP'saremanuallytrippedbythe'perator.ThecoastdownofthepumpsdecreasestherateofdecayheatremovalandmaintainstheRCScoolanttemperaturesandpressureathighervalues.Auxiliaryfeedwaterflowisdeliveredtobothsteamg'eneratorsat188.4seconds.ThesubcooledfeedwaterflowcausesanadditionalcooldownoftheRCS.ThedecreasingRCStemperatures,incombinationwithanegativeMTC,resultinpositivereactivityinsertionwhichenablesthecoretoapproachcriticality.ThenegativereactivityinsertedbytheCEAsandtheboroninjectedviatheHighPressureSafetyInjection(HPSI)pumps,.however,issufficienttomaintainthecoreinasubcriticalcondition.Table7.1.3-2presentsthesequenceofeventsforanExcessLoadeventinitiatedatHFPconditions.Figures7.1.3-1to7-1.3-5showtheNSSSresponseforpower,heatflux,RCStemepratures,RCSpressure,andsteamgeneratorpressureduringthisevent.TheZeroPowerExcessLoadeventwasinitiatedattheconditionsgiveninTable?.1.3-3.Theh)TCandFTCvaluesassumedintheanalysisarethesameasforthefullpowercaseforthereasonspreviouslygiven..TheminimumCEAshutdownworthavailableisconservativelyassumedtobe-4.3Ãap.TheresultsoftheanalysisshowthataVariableHighPowertripoccursat44.6seconds.TheminimumDNBRcalculatedduringtheeventis3..15andthepeaklinearheatgenerationrateis11.59KW/ft.FortheZP'xcessLoadevent,anSIASsignalonlowpressurizerpressureisgeneratedat73.7seconds.At224.6secondsauxiliaryfeedwater'flowisdeliveredtobothsteamgenerators.TheadditionalpositivereactivityresultingfromtheenhancedcooldownoftheRCSismitigatedbythenegativereactivityinsertedduetotheCEAsandtheboroninjectedviatheHPSIpumps.Thenegativereactivityaddedissufficienttomaintainthecoresubcriticalatalltimesafterauxiliaryfeedwaterflowisinitiated.The.sequenceofeventsforthezeropowercaseispresentedinTable7.1.3-4.Figures7.1.3-6to7.1.3-10showtheNSSSresponseforcorepower,coreheatflux,RCStemperature,RCSpressureandsteamgeneratorpressure.ForthefullandzeropowerExcessLoadeventsinitiatedbyafullopeningofthesteamdumpandbypassvalves,theDNBRandCTHlimitsarenotexceeded.Inaddition,thecoreremainssubcriticalfollowingautomaticinitiationoftheauxiliaryfeedwaterflowandmanualtrippingoftheRCP'sonSIASduetolowpressurizerpressure.ThereactivitytransientduringaHFPandHZPExcessLoadeventislesslimitingthanthecorrespondingSteamLineRuptureevents.
~Tab1e7.1.3-1KEYPARAMETERSASSUMEDFORFULLPOWEREXCESSLOADEVENTANALYSISParameterInitialCorePowerLevelCoreInletTemperatureReactorCoolantSystemPressureCoreMassFlowRateModeratorTemperatureCoefficientCEAWorthAvailableatTripDopplerMultiplierInverseBoronWorthAuxiliaryFeedwaterFlowRateHighPowerLevelTripSetpointLowS.G.WaterLevelTripSetpointUnitsMWtOFpsiaxlOibm/hrx10hp/FPPM/Capibm/secX.ofFullPower~Cele327545512200133.7-2.5-4.3e85105125.4/S.G.11229.9Reference.CycleisFSAR.FullPower.ExcessLoadresultswerenotpresentedinFSAR,thereforenocomparisonismade.
Table7.1.3-2SEQUENCEOFEVENTSFORTHEEXCESSLOADEVENTATFULLPOWERTOCALCULATEMINIMUMDNBRTime(sec)0.08.89.39.310.054.054.169.372.573.313P.5188.4600.0EventCompleteOpeningofSteamDumpandBypassValvesatFullPowerHighPowerTripSigna1GeneratedTripBreakersOpenCEAsBegintoDropIntoCoreMaximumPower;MaximumLinearHeatGenerationRateOccursMinimumDNBROccursSafetyInjectionActuationSignalGenerated;ManualTripofRCP'sPressurizerEmptiesRampdownofMainFeedwaterFlowCompletedMainSteamIsolationSignalLowSteamGeneratorLevelTripSetpointReachedIsolationofMainFeedwaterFlowtoBothSteamGeneratorsAuxiliaryFeedwaterFlowOeliveredtoBothSteamGeneratorsOperatorTerminatesAuxiliaryFeedwaterFlowtoBothSteamGeneratorsSetointorValue112Koffullpower114.4Xoffullpower18.3KW(ft1.291578psia5Xoffullmain=feedwaterflow578,psia29.9ft125.4lb/sectoeachsteamgenerator ttKEYPARAMETERSASSUMEDFORHOTSTANDBYEXCESSLOADEVENTANALYSISParameterInitialCorePowerLevelCoreInletTemperatureReactorCoolantSystemPressureCoreMassFlowRateModeratorTemperatureCoefficientCEAWorthAvailableatTripDopplerMultiplierInverseBoronWorthVariableHighPowerTrip'SetpointLowS.G.MaterLevel-TripSetpointAuxiliaryFeedwaterFlowRateUnitsMWt0Fpsiax101bm/hr6x10hp/FXhp"'PM/Sap5of-'-.fullPowerftibm/sec~Cele55322200137.0-2.5-4.3.851004029.9125.4/S.G.ReferenceCycleisFSAR..
'Table'7;l;3-'4SEQUENCEOFEVENTSFOREXCESSLOADEVENTATHOTSTANDBYCONDITIONSTOCALCULATEMINIMUMDNBRTime(sec)0.044.645.0'5.545.6'ventSteamDumpandBypassValvesOpentoMaximumFlowCapacity.VariableHighPowerTripSignalGeneratedTripBreakersOpenCEAsBegintoDropintheCoreMaximumPower;MaximumLinearHeatGenerationRateOccursSetointorValue40Koffullpower41.09Ãof.fullpower11.59KM/ft.46.167.771.173.7131.1MinimumDNBROccurs(CE-.2)PressurizerEmptiesMainSteamIsolationSignalGeneratedSafetyInjectionActuationSignalGenerated;ManualTripofReactorCoolantPumpsIsolationofMainFeedwaterFlowtoBothSteamGenerators"vvIg'3.150578psia1578psia224.6600.0AuxiliaryFeedwaterFlowDeliveredtoBothSteamGeneratorsOperatorTerminatesAuxiliaryFeedwaterFlowtoBothSteamGenerators125.4lb/sectoeachsteamgenerator 12GiGOCDFIJLLPOWERLIJSG'uJQCLi'LJ60CL.ul401GG2003GG400TINE~SECONDSSGOFLORIDAPOWER5LIGHTCOSt.LuciePlantUnit1EXCESSLOADINCIDENTCOREPOMERVSTINEFIGURE7.1.5-1 120I-1GOI-80OCFULLPOMERUJ40201GO20030040GTINE.SECONDS6GOFLORIDAPOWER8LIGHTCOeSt.LuciePlantUnit1EXCESSLOADINCIDENTHEATFLUXYSTINEFIGURE7I1I3-2
'GGFULLPOWERTOUTTAVGCY.'00Z:300TAYG=AVERAGECORECOOLANTTENPERATUREOUTCOREOUTLETTENPERATURETINCOREINLETTENPERATURE10001002003004GOTINESECONDSSO0S00FLORIDAPOWER8tLIGHTCO>St.LucieP1antUnit1EXCESSLOADINCIDENTTPIPERATUREYSTIYiEFIGURE~7.1,3-3 24002GGGFULLPOWER160012GGSGO1GO200300400SGOBGGTIME.SECONDSFLORIDAPONER5LIGHTCO<St.LuciePlantUnitIEXCESSLOADINCIDENTNAINSTEANPRESSUREVSTINEFIGURE7.1,3-0
>2GOFULLPOMER8GGSOO+(y.1p<Pt('D4GG2GO1GO2003GO400TINESECONOSSGO600FLORIDAPOWER5LIGHTCOsSt.Lucie1Unit1EXCESSLOADINCIDENTREACTORCOOLANTSYSTEMPRESSUREVSTIMEFIGURE7.~.3-5
12C100~e80QHOTSTANDBYQJ60CDQCD4020200300400TINE.SECONDSFLORIDAPOWER5LIGHTCOSt.LuciePlantUnit1EXCESSLOADINCIDENTCOREPOMERYSTINEFIGURE7,1,3-6
..120UCDI-UJUJO-iOOtIOTSTANDBY100200300400TIME.SECONDS50CFLORIDAPONERQLIGHTCOISt.LuciePlantUnitI.EXCESSLOADINCIDENTHEATFLUXVSTINEFIGURE7.1.3-7 700HOTSTANDBY5GO40G300200'TAVGTINTAVG=AVERAGECORECOOLANTTEMPERATURETOUT=COREOUTLETTENPERATURE'INCOREINLETTENPERATUREa'C'10G10020030040050G.600TINESECONDSFLORIDAPOWERImtLIGHTCOSt.LuciePlantUnit1EXCESSLOADINCIDENTTENPERATUREYSTINEFIGURE7.1,3-8 24CO2CGCHOTSTANDBY160012008001GG2003GQ400SGQBCGTIVE,SECQNt'5FLORIDAPOWERgLIGH'ICOsSt.LuciePlantUnit1EXCESSLOADINCIDENTREACTORCOOLANTSYSTENPRESSUREYSTINEFIGURE7e1,3-9 12001000HOTSTANDBY8006004GO0100200300400TINESECONDSS00BGGFLORIDAPOWER5'LICHTCOgSt.LucieP'tantUnit1EXCESSLOADINCIDENTNAINSTENRPRESSUREVSTINEFIGURE7,i,3-10 TheSteamGeneratorTubeRupture(SGTR)eventwasreanalyzedforCycle5toverifythatthesiteboundarydoseswillnotexceedtheguidelinesof10CFR100followingpostTMINRCrequirementtomanuallytriptheReactorCoolantPumpsonSIASduetolowpressurizerpressure.ThedesignbasisSGTRisadoubleendedbreakofonesteamgeneratorU-tube.Table3.2.3.3-1liststhekeytransientrelatedparamtersusedinthisanalysis.Intheanalysis,itisassumedthattheinitialRCS-pressureisashighas2300psia.ThisinitialRCSpressuremaximizestheamountofprimarycoolanttransportedtothesecondarysteamsystemsincetheleakrateisdirectlyproportionaltothedifferencebetweentheprimaryandsecondarypressure.Inaddition,thehigherpressurey".;-..-"'elaysthelowpressurizerpressuretripwhichprolongsthetransient.',,andthereforemaximizesthetotalprimarytosecondarymassandacti.vriestransport'ed.Forthisevent,theacceptableDNBRlimitisnotexceededduetothe..actionoftheThermalMargin/LowPressure(TM/LP)tripwhichprovides"-,areactortriptomaintaintheDNBRabove1.30.Thetuberupturetrans'identdoesnotsignificantlyaffectthecorepowerdistribution.'Therefore'">>"thePLHGRSAFDLisnotapproached.TheThermalMargin/LowPressuretrip,withconservativecoefficientswhichaccountforthelimitingradialandaxialpeaks,maximuminlettemper'ature,RCSpressure,corepower,andconservativeCEAscramcharacteristics,wouldbetheprimaryRPStripinterveningduringthecourseofthetran-sient.However,tomaximizethecoo'lanttransportedfromtheprimarytosecondaryandthustheradioactivesteamreleasestotheatmosphere,theanalysiswasperformedassumingthatthereactortripisnotinitiatedun-tiltheminimumsetpoint(floor)oftheThermalMarqin/LowPressuretrip(i.e.,LowPressurierPressureTrip)isreached.Thisprolongsthesteamreleasestotheatmosphereandthusmaximizes,thesiteboundarydoses.TheSteamGeneratorTubeRupture'asanalyzedforapowerlevelof2754M!(t(102/of2700Ml<t)..The'resultswillbeapplicableto2560Miltsincethehigheroperatingpowerleadstomoreconservativesiteboundarydoses.Theanalysisassumesoperationof3HighPressureSafetyInjectionpumps.Thisassumptionleadstofasterrefillingofthepressurizer,thereforeresultinginhigherRCSpressureandthus,increasingtheprimarytosecondaryleak.ThemethodologyfollowedisconsistentwiththemethodspreviouslyusedandapprovedbyNRC.ThesemethodsaredocumentedinReference3.Table3'3'-1showsthekeyparametersassumedintheanalysisoftheevent.ThesequenceofeventsfortheSGTReventwithmanualtripofRCPsispresentedinTable3.2.3.3-2.
Theanalysisconservativelyassumedthatat1800seconds,theoperator'nitiatescooldownbyusingtheAtmosphericDumpValves(ADV).Theanalysisdidnotcredittheuseofsteamdumpandbypasssystemtothecondenser.TheuseofatmosphericdumpvalvesresultsinasubstantialincreaseinthecalculatedsiteboundarydosesincetheADVpartitionfactoris.1comparedto.0005forthecondenserairejectors.Figures3.2.3.3-1through3.2.3.3-5presentthetransientbehaviorofcorepower,heatflux,RCSpressure,RCStemperatures,andsteamgeneratorpressure.I-131activityreleaseisbasedontheTechSpecallowedprimarytosecondaryleakrateof1GPMandonthesteamflowrequiredtocooltheplanttocondi-tionswheretheshutdowncool,ingsystemcanbeinitiated.Thisreleaseiscalculatedastheproductof-:st'earnflow,thetimedependentsteamactivityandthedecontaminationfactorsapplicabletoeachreleasepathway.The0to2hourI-131site;boundarydose,iscalculatedfrom:DDSE(REM)AI-131+BPx>xCFI-131where:AI-131BRx/QCFI-131I-131activityreleased.tositeboundary,Ci,breathingrate,m/sec,dispersioncoefficient,sec/m,I-131doseconversionfactor,Rem/Ci..Indeterminingthewholebodydose,'hemajorassumptionmadeisthatallnoblegasesleakedthroughtherupturedtubewillbereleasedtotheatmosphere.Therefore,thewholebodydoseisproportionaltothetotalprimarytosecondaryleakandiscalculatedusingthefollowingequation.i<holeBodyDose=[.25(K+-E)]*L*A*-.25gRCSg,where:EYERCSg/((averageenergyreleasebygammadecay,averageenergyreleasebybetadecay,totalprimarytosecondarymasstransportnoblegasactivityofprimarycoolantdi".)ii'r'nc'o<'tli<i<'nt.
~~
Theresultsoftheanalysisarethat81540lbs.ofprimarycoolantaretransportedtothesteamgeneratorsecondary.side.BasedonthismasstransportandvaluesinTable3.2.3.3-3,the0-2Hrsiteboundarydosescalculatedare:Thyroid(DEQI-ll):0.32RENWholeBody(DEQXe-133):0.08RENThereactorprotectivesystem(i.e.,TN/LPtrip)intervenestoprotectthecorefromexceedingtheDHBRlimit.Thedo'sesresultingfromtheactivityreleasedasaconsequenceofhdouble-endedruptureofonesteamgeneratortube,assumingthemaximumallowableTechSpecactivityfortheprimaryconcentrationatacorepowerof2754NIlt,aresignificantlybelowtheguidelinesof10CFR100.Thus,theresultsdonote'xceedacceptancecriteria.
TABLE7.3.3-"1KEYPARAMETERSASSUMEDIHTHESTEANGENERATORTUBERUPTUREEYEtlTKEYTRANSIENTRELATEDPARAMETERS:ParameterPowerMTCDopplerCoefficientMultiplierScram1/orthinRCSPressureInitialCoreMassFlowRate(548oF,2200psia)InitialSecondaryPressureUnitsxl0ap/'Fpsiax10.lb/hrDsiaFSAR2611-2.51.154.555442300117,.5841~Cele52754-2.51.15-4.0.2300133.99O2.0 g~~TABLE7.'3;3-2SEQUENCEOFEVENTSFORTHESTEAMGENERATORTUBERUPTUREEVENTWITHRCPCOASTDOllNONSIASTime(sec)0.0577.2577.4578.6579.1584.8587.4588.01395.41800.07859EventTubeRuptureOccursLowPressurizerPressureTripSignalGeneratedDumpValvesOpenCEAsBegintoDropIntoCoreBypassValvesOpenMaximumSteamGeneratorPressurePressurizerEmptiesSafetyInjectionActuationSignalGenerated;RCPsManuallyTrippedIMinimumRCSPressureOperatorIsolatesDamagedSteamGeneratorandBeginsCooldownto325'FOperatorInitiatesShutdownCooling(TAVF)SetpointorValue1853psia949psia1578psia1034psia TABLE7.3.3-3ASSUMPTIONSFORTHERADIOLOGICALEVALUATIONFORTHESTEAMGEhERATORTUBERUPTUREParameterReactorCoolantSystemMaximumAllowableConcentration(DEQI-131)SteamGeneratorMaximumAllowableConcentration(DEQI-131)1ReactorCoolantSystemMaximumAllowableConcentrationof'obleGases(DEQXe-133)1AtmosphericDumpValvePartitionFactorCondenserAirEjectorPartitionFactorAtmosphericDispersionCoefficientBreathingRateDoseConversionFactor(I-131)unitsyCi/gmuCi/gmpCi/gmsec/mm/secREM/CiCcle5Value1.0100/E.00058.55x10.3.47x101.48xlOTechSpeclimits.P0-2houraccidentconditionforSt.LucieUnit1.
,c7C 110998"7755UJgqCD3222020090060080010001200100016001800TIl'lE,SECONDSFLORIDAPOV/ER6LICL<TCO.St.LvciePIont)TEAt"lGEI",ERECTORTUBEFAILUREEVENT~COREPOYiERvsTIk'IEFigure~7.3.3-1
~1~110ag776655220.III02004006008001000120Q1000160Q1800TINE,SECONDSFl.ORIDAt'O'"'L'."",l.t.Ci!TCC.5t.Lv-tef'loci(STEAMGENERATORTUBEFAILLE,iEE'LtEiilTCORfAVFiliXGFflEATFIUi'ivsTIA'iEFlgVfC7~3&32~~~
~~~2403220D200318001603D.140312031000.02000006008001000120014001600.1300TINE,SECONDSFLORIDAPOVCER5LlGt<TCQ.St.LucioPlontS)EAMGEIJERATORTURNEFAILUREEVEi'lTREACTORCOOLAl'JTSYSTEM:lPRESSUREvsTIi~,EFicure7%3&33 65J603550500CD05.0TOtjTLETTAYERAGETINLETIIII0200400600800.1000.1200100016001800TIME,SECONDSFlORIDAPOWER8LIGHTCO.5t,LvcicPIai:ISTEAI';1GENERATORTU~uEFAILUREEVE:~TPEACTPRCPOl.ANTS'(STEMMATEMPERATUREvsTITLEFIgv;c:7.3.3-4 950900850800750c700650600550500II0200000IIII60080010001200100016001800TINE,SECONDSFigurc7.3.3-Qfv,~)I<