ML17212A709

Application for Amend to License DPR-67 Submitted as Response to NRC 810728 Info Request & Proposed Amends to Tech Specs Re Boration Control,Moderator Temp Coefficient, Reactor Coolant Pumps & Boron Dilution & Addition

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: ML17212A709 ML17212A711
References
L-81-388, NUDOCS 8109100207
Download: ML17212A709 (52)

Text

REGULATOR NFORMATION DISTRIBUTION STKM(RIDS)ACCESSION NBR:8109100207 DOC~DATE':61/09/04NOTARIZED INOFACILt;50-335 St,LUciePlantEUnit1<FloridaPower8LightCo.AUTH',NAME'UTHOR AFFILIATION UHRIGgR,E, Flor,ida-Power8LightCo,RECIP~NAMElRECIPIENTAFFILSATION-CLARiX"PR

~ADOperating, ReactorsBranch3

SUBJECT:

Application foramendtoLicenseDPR-67submitted asresponsetoNRC810728inforequest8proposedamendstoTe'chSpecsreborationcontrolimoderator tempcoefficienti reactorcoolantpumps8borondilution8,addition.'ISTRIBUTION CODE;:AOOIS,.COPIESRECEEVED:l.iTR

+ENCL+SIZE'::'lITLEt:-

GeneralDistributionforafter>>Issuance~

ofOperating LiicenseiVOTES:OOCKEll'"

005000335RECIPlKNT IDCODE/NAMEI ACT'ION:"

ORB03BC!04"INTKRNALl, D/DIRPHU4l FACOBI8Ei06'RASSESS'R10.L01COPIESLTTRENCL>>13131221011RECIPIENT IOCODE/NAME DIRiDIVOFLICOELD11RADASMTBRCOPIESLlTTRiENCLI11101KXTERNALi:

ACRSNRCPDRNTIS0902i1616LPDR11,NSIC1103051111gp1gqgSETOTALNUMBEROFCOPIESREQUIRED:

LTTR41ENCL'l39 llrtkttIII

~+~wc'efP.o.BOX629100,MIAMI,FL33162fkvv<4%FLORIDAPOWER&LIGHTCOMPANYSeptember 4,1981L-81-388OfficeofNuclearReactorRegulation U.S.NuclearRegulatory Commission Washington, D.C.20555Attention:

Mr.RobertA.Clark,ChiefOperating ReactorsBranch$/3

Subject:

St.LucieUnit1DocketNo.50-335StretchPowerProposedAmendment cS~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:

Inresponsetotheinformation requestofyourReference 1letter,wehaveenclosedresponses toyourten(10)questions inAttachment 1tothisletter.Inordertoclarifytherelationship ofourReference 3submittal (Shutdown MarginandMTCchanges)toourReference 2submittal (StretchPower)wehavedescribed theproposedamendment toStretchbelowandhaveenclosedallthepertinent amendedTechnical Sepcification pagesinAttachment 2tothisletter.Paes3/0l-lR3/01-2R3/01-5R3/00-1RB3/0l-lTherequirements forshutdownmarginwereincreased, andashutdownmargincalculation changewasadded.Therequirements forpartloopoperation weresimplified andtheshutdownmarginrequirements decreased slightly.

Therequirement forthemoderator temperature coefficient (MTC)atratedthermalpowerwaschanged.Theproposedamendment toStretchhasbeenpreviously reviewedandapprovedbytheSt.LucieFacilityReviewGroupandtheFloridaPower*LightCompanyNuclearReviewBoard.Specifically thenewrequirements forshutdownmarginandMTCareboundedinalltheotheranalyseswhichusethemoreconservative valuesof0.3%Ijhk/kand-2.5x10-<hk/k/OF,respectively.

Furtherwewereabletosimplifytherequirements forpartloopoperation 8109100207 Bi0904PDRADOCK05000335PORPEOPLE...

SERVINGPEOPLE 1'.'-P./CASA~~>>'i:~a','1gf.".J3f;~~tL1\I)l'AJJ4~'VJ<)I~I.)~,-~>'.~'~Ic~J*

becausetherequiredreactorcoolantpump(RCP)tripcausesthefullloopandpartloopeventstobehavewithnosignificant differences inresults.T-Wehaveenclosedthesafetyevaluations fortheExcessLoad(EL)andtheSteamGenerator TubeRupture(SGTR)eventsinAttachment 3tothis.letter.TheseeventsalongwiththeSteamLineRupture(SLB)event(submitted throughReference 3)werereanalyzed forCycle5toincludetheeffectofNRCmandatedTMI-2relatedoperational anddesignchanges,i.e.automatic initiation ofauxilliary feedwater flowandmanual,tripofallfourRCPs.Otheranalysesarenotsignificantly affectedbythesechanges.Thesethreeeventsafetyevaluations (SLB,ELandSGTR)shouldreplacethosesubmitted throughReference 2.NonewTechnical Specification changestoStretch,otherthanthoseinAttachment 2tothisletter,ariseasaresultofthereanalysis oftheseevents.Alsotheresponses toquestions onSLBandSGTR(Questions 7,8,and9)inAttachment 1tothisletterarebasedontheserevisedanalysesinAttachment 3andReference 3.VerytyoursRobertE.UhrigVicePresident AdvancedSystems2Technology cc:Mr.J.P.O'Reilly,

Director, RegionIIMr.HaroldF.Reis,Esquire ATTACHMENTI 4guestion1Theinverseboron'worth valueslistedinTable7.1.1-1areincreased forallmodesofoperation.

Increased inverseboronworthmeansthatmoreboronmustbedilutedforagivenchangeinreactivity, whichislessconservative.

Oescribethebasesforandjustifythenewvaluesofinverseboronworthforeachmodeofoperation.

~ResenseThenewinverseboronworthsreportedinTable7.1.1-1arebasedonexplicitdiffusion theoryca1culations ofreactivity whichspanthe'powerlevelsandtemperature rangeallowedwithineachoperating mode.Theseinverseboronworthsareconsistent withthecriticalboroncon-centrati'ons showninTable7.1,1-1.Althoughthei'nverseboronworthshaveincreased whencomparedtotheReference Cyclevalues,thenewvaluesreportedinTab'le7,1.1-1aresttlll.owerthantheexplicitCycle4cal-culatedvalues.Sincethenewvaluesboundtheexplicitcalculated values,theirusejnthe,Cycle4borondilutioneventisjustified.

Ouestion211Therefueling shutdownmarginlistedinTable7.1.1-1hasbeenchangedfrom9.45Ãsubcritical to6.28Ãsubcritial, whichreducesthedilutiontimetoreachcriticality

.Whatistheboronconcentration thatcorresponds withthenewshutdownmargin?Comparethiswiththepreviousrefueling boronconcentration.

~ResenseThecriticalboronconcentration forCycle4is1280PPM,incomparison tothereference cyclevalueof1200PPH.Theinitialboronconcentra-tionforbothCycle4andthereference cycleistheminimumrequiredTechnical Specification boronconcentration of1720PPM.

~Iuestion3TheresultsoftheborondilutioneventsshowninTable7.1.1-2listthetimetoloseprescribed shutdownmarginforeachmode.PleasebeawarethatSPRSection15.4.6specifies minimumtimesfromwhenanalarmmakestheoperatorawareofanunplanned dilutioneventasacceptance criteria.

Whatalarmsmakestheoperatorawareofborondilutionineachmode?Whatarethesetpoints, timedelays,anderrorsassociated withdetection andalarmsystems,andhowaretheseaccounted forinthetimefortheoperatortoreacttoaborondilutionevent?ResponseTheindicators thatareavailable totheoperatorfordetermining ifanunplanned dilutionisinprogressare:1)thestartupfluxchannels, 2)thelowlevelalarmontheVolumeControlTank,3)theboronometer and4periodicsampling.

Depending onthemodeofoperation andontherateofdilution, oneoralloftheseindicators wouldalerttheoperatorthataninadvertent dilutionisinprogress.

Theleastamountoftimetolose'rescribed shutdownmarginisinMode5.Theprimaryindicator inMode5is.thestartup'lux channels.

TwostartupfluxchannelsarerequiredtobeoperableinMode5bytheTechnical Specifications.

Procedures willbedeveloped whichwillrequiretheoperatorto:a)b)ObservethecountrateuponenteringMode5,Periodically checkthatthecountratehasnotincreased (theintervalisdependent onthenumberofchargingpumpsinoperation andtheliquidvolume.intheRCS),c)Takecorrective actionwheneverthecountrateexceedsaprescribed value(i.e.,effectively analarmlimit)Theseactionsaresufficient becauseinNode5theboronconcentration isnormallyhigherthanrequiredbyTechnical Specications.

Thishigherconcentration resultsfromnotdilutingfromthehigherrequiredconcentrations forNodes4and6.Itshouldalsobenotedthatpastexperience atSt.Luciehasverifiedthequalityofoperatortrainingandoperatoractionduringaborondilutionevent,LER335-80-71 reportedaborondilutionatpowerwhichwascorrectly controlled bytheSt.Lucieoperators.

Isuestion4Theparameters showninTable7.1.4-4arestatedtomaximizethecalculated peakRCSpressureforalossofloadevent.However,theinitialpressureof2200psiaislowerthanthevaluepreviously utilized(2250psia)tomaximizetheRCSpeakpressure.

Providefurtherdiscussion onwhyalowerinitialpressureisconservative, orevaluatetheeffectsofahigherinitialpressureonthecal-culatedpeakpressure.

~ResenseTheuseofthelowestinitialRCSpressureisconservative sincethisdelaysthetimeofHighPressurizer Pressure(HPP)trip.DelayingthetimeofHPPtripmaximizes therateofpressurein-creaseatthetimeoftripandtherebymaximizes thepressureover--shootafterreactortrip.Thisresultsin.thepeakRCSpressureduringtheevent.

Therefore, thelowestRCSpressureof2200psiaallowedbytheTechnical Specification wasconservatively assumedtodetermine.

thepeakpressureduringtheLossofLoadev'ent; guestion5TheLossofCoolantFlowanalysishasseveralareaswhicharenotfullyaddressed andmaybenon-conservative.

Pleasediscussthefollowing:

1)Theinitialcorepowerisat100%ratherthan102ÃasrequiredbySRPSection15.3.1;2)Theassumedscramcharacteristics donotdiscussifthemostreactiverodisheldoutofthecore;3)t<obasesareprovidedtojustifythepumpcoastdown curve.~Resonse1)Reference 1documents C-E'sstatistical combination ofuncertainty methodology.

Themethodsandinitialconditions usedintheLossofFloweventareconsisteqt with/hosereportedingeferencq

.I,.Inparticular, theuncertainty ininitialpowerleveiisincludedas.,a-t'erm inthetotaluncertainty.

Therefore, aninitialpowerlevelof100wasassumedintheLossofFloweventanalysis.

2)The,:;,-scram worthusedintheanalysiswascalculated withthemost",reactive rodheldoutofthecore.3)The'-pump coastdown curveusedintheLossofFloweventiscalculated usingthecodeCOAST(Reference 2).Thiscoastdown curveis'identical totheone.usedandacceptedbytheNRCintheFSARandpreviousreloadsafetyanalysis..

References

'1.CEH-12(F)-'P, "Statistical Combination ofUncertainties, Part.3,"March1980.2.CENPD-98, "COASTCodeDescription,"

May1973.

1t(}uestion 6TheLossofNon-Emergency ACPowereventutilizesthesameDNBanalysisusedfortheLossofCoolantFlowtransient (7.2.2).Theitemsinquestion5mustbesatisfactorily resolvedbeforetheanalysisforLossofACPowerwillbeconsidered valid.1n~addition, thevalueof1.15usedforthedopplercoefficient multiplier mustbejustified asconservative considering thepreviousvalueof0.85usedintheFSAR.~ResenseAdopplercoeff'icient multiplier of1.15wasusedintheanalysissincethisresultsinaslowerpowerrampdownfollowing reactortrip.Thisincreases theresidualheatthatmustberemovedduringplantcooldownandincreases thesteamreleases.

Highersteamreleasesduringthecooldownincreases thesiteboundarydoses.Thus,itisconservative touseadopplercoefficient multiplier of1.15.

uestion7providejustification forthevaluesoftheinitialcorecoolanttemperature andpressuretoshowthattheyareconservative fortheSteamLineBreakanalysis.

Also,discussthebasisfortheinitial,coreflowratesassumedandthedelayedneutronfraction.

~ResenseThemaximuminitialcorecoolanttemperature allowedbytheTechnical Specification wasusedintheanalysis.

Thiscausesthegreatestcoolanttemperature decreaseduringtheevent,whichresultsinthemaximumpositivereactivity insertion duetomoderator feedback..

Thegreatestamountofpositivereactivity insertion enhancesthepotential forReturn-to-Criticality (R-T-C)andReturn-to-Power (R-T-P).TheSLBeventinitiated withthe.maximuminitialRCSpressuredelaystheinitiation ofSafetyInjection Actuation Signal(SIAS).Thisresultsintheleastamountofnegativereactivity addedtothecoreduetoboroninjected,via the,HighPressureSafetyInjection (HPSI)pumps,Thesmalleramountofnegativereactivity insertedenhancesthepotential forR>>T-CandR-T-P.0Themaximumvalueforthedelayedneutronfractionatendofcyclewasassumedintheanalysis.

Themaximumvalueincreases thesubcritical multiplication andthusenhancesthepotential forR-T-P.Theinitialcoremassflowrateassumedintheanalysisisconsistent with'heminimumguaranteed Technical Specification vesselflowrateof370,000GPN.

uestion8NoDNBanalysiswasperformed despitetherapidsystemdepressurization.

WhataretheminimumDNBratioscalculated?

~ResenseTheminimumDNBRduringthetransient wascalculated usingtheMacBethrodclustercorrelation (Reference 1)withtheLeenon-uniform heatfluxcorrection factor(Reference 2).Theminimum.transient DNBRfortheHFPSLBeventoccursat145secondsandisequalto1.27.References 1..R.V.MacBeth,"Anappraisal ofForcedConvection Burn-OutData",Proc.Instn.Mech.Engrs.,1965-66,Vol.180,Pt.3C,pp.37-50.2.D.H.Lee,"AnExperimental Investigation ofForcedConvection BurnoutinHighPressureMater;PartIV,LargeDiameterTubesatAbout1600psia",AEBl-R479,November, 1966.

uestion9',TheSteamGenerator TubeRuptureEventshows.arapiddropinRCSpressureandtemperature atabout600secondsinFigures7.3.3-3and7.3.3-4.Pleaseprovidefigureswithfinerdetailinthisregion(approximately 550'o650seconds)andevaluatethechancesofandeffectsofsteambubbleformation inthevesselheadorhotlegs.Theeffectsofsteambubbleformation onthe"radiological evaluations shouldalsobeconsidered.

~ResenseAsrequested, Figures1and2presentinfinerdetailtheRCSpressureandtemperature from550secondsto650seconds.Thereference, preparedinresponsetopreviousNRCquestions onupperheadvoiding,confirmsthatthemodelbeing-usedinthisanalysisadequate1y addresses theeffectsofsteambubbl'eformation inthevesselupperheadandhot'egsduringaSteamGenerator TubeRuptureevent.Inaddition, the.the.reference containsanevaluation oftheradiological doseduetosteambubbleformation.

'eference:

LetterfromRobertE.UhrigtoDarrellG.Eisenhut, "St.LucieUnit1DocketNo.50-335Natural'irculation Cooldown",

L-81-43,February9,1981; guestion10TheSeizedRotoranalysisdoesnotincludeacalculated DNB,MDNBR{accounting forstatistical uncertainties withthenewC-Emethodology) orapeakcladtemperature asrequiredbySRPSection15.3.3Pleaseprovidethisinformation andconfirmthatthemostreactiverodwasassumedstuckoutofthecore.~ResonseTheminimumONBRforaSeizedRotoreventinitiated fromTechnical Specification DNBLimitingConditions forOperation is1.025~AsstatedinSection7.3.4,thepredicted numberoffuelpinfailuresisnotbasedonasingleHDNBRvaluebutisca]'c61ated throughadistribution ofthefractionofpinswithapar'ticular ONBRasafunctionofDNBR.Thisdistribution isthen,:,convoluted withaprobability ofburnoutvs.DNBRtoobtaintheamount,offuelfailure.Thescramworthusedinanalyzing this.event'~was calculated assumingthatthemostreactiverodisstuckoutofthe,-.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 ATTACHMENT 2

ATTACHMENT 3

7.1.3ExcessLoadEventTheExcessLoadEventwasreanalyzed todetermine thattheDNBRandCTMdesignlimitsarenotexceededduringCycle5.TheanalysesincludedtheeffectsofmanuallytrippingtheRCP'sonSIASduetolowpressurizer pressureandtheinitiation ofauxiliary feedwater flow180secondsafterreactortrip.TheHighPowerLeveland.ThermalMargin/Low Pressure{TM/LP)tripsprovideprimaryprotection topreventexceeding theDNBRlimitduringthefullpowerExcessLoadevent.Additional protection isprovidedbyothertripsignals.including highrateofchangeofpower,lowsteamgenerator waterlevel,andlowsteamgenerator pressure.

Theapproachtothe.CTMlimitsisterminated byeithertheAxialFluxOffsettrip,theDNBrelatedtriportheHighPowerLeveltrip.In,thisanalysis, creditis,takenonlyfortheactionoftheHighPowerLeveltripinthedetermination oftheminimumtransient DNBRandmaximumCTM.ForthezeropowerExcessLoadtransient, protection isprovidedbytheVariableHighPowerLeveltriptopreventviolation oftheDNBRandCTMliririts.

Aspresented intheFSAR,themostlimitingloadincreaseeventsatfullpowerandhot.Rempowerconditions"occur'or the.completeopeningofthe.steamdumpandbypass'valves.Ofthesetwoevents,thefullpowercaseisthe'morelimiting{i.e.,approaches closertotheacceptable DNBRandCTMlimits)case.Forconservatism intheanalyses, auxiliary feedwater flowratecorresponding to15.3%offullpowermainfeedwater flow(i.e.,7.66Koffullpowermainfeedwater flowpergenerator) wasassumed.Theadditionoftheauxiliary feedwater toeachsteamgeneratorwasinitiated at180seconds,afterreactortrip.Theadditionofauxiliary feedwater enhancesthecooldownoftheRCSandthepotential forareturn-to-power

{R-T-P)orcriticality arisingfromreactivity feedbackmechanisms.

>TheExcessLoadeventatfullpowerwasinitiated attheconditions giveninTable7.1.3-.1.

A,Moderator Temperature Coefficient of-2.5x10-"

ap/oFwasassumedintheanalysis.

ThisMTC,inconjunction withthedecreasing coolantinlettemperature, enhancestherateofincreaseinthecoreheatfluxatthetfmeofreactortrip.5minimumFuelTemperature Coefficient (FTC),corresponding tobeginning ofcycleconditions withanuncertainty of155,wasusedintheanalysissincethisFTCresultsintheleastamountofnegativereactivity additiontomitigatethetransient increaseincoreheatflux.TheminimumCEAworthassumedtobeavailable forshutdownatthetjmeofreactortripforfullpoweroperation is4.3Xap.Theanalysisconservatively assumedthattheworthofboroninjectedbythesafetyinjection systemis-1.0Ãapper105PPM.Thepressurizer pressurecontrolsystemwasassumedtobeinoperable becausethisminimizes theRCSpressureduringtheeventandtherefore reducestheca1culated DNBR.Allothercontrolsystemswereassumedtobeinmanualmodeofoperation andhavenosignificant impactontheresultsforthisevent.

TheFullPowerExcessLoadeventresultsinaHighPowerLeveltripat8.4seconds.TheminimumDNBRcalculated fortheeventattheconditions speci-.fiedinTable7.1.3-1is1.29comparedtothedesignlimitof1.23.Themaximum.locallinearheatgeneration ratefortheeventis18.3KW/ft.FortheExcessLoadeventinitiated fromHFPconditions, SIASisgenerated

't54.0seconds.Upongeneration ofanSIAS,theRCP'saremanuallytrippedbythe'perator.

Thecoastdown ofthepumpsdecreases therateofdecayheatremovalandmaintains theRCScoolanttemperatures andpressureathighervalues.Auxiliary feedwater flowisdelivered tobothsteamg'enerators at188.4seconds.Thesubcooled feedwater flowcausesanadditional cooldownoftheRCS.Thedecreasing RCStemperatures, incombination withanegativeMTC,resultinpositivereactivity insertion whichenablesthecoretoapproachcriticality.

Thenegativereactivity insertedbytheCEAsandtheboroninjectedviatheHighPressureSafetyInjection (HPSI)pumps,.however, issufficient tomaintainthecoreinasubcritical condition.

Table7.1.3-2presentsthesequenceofeventsforanExcessLoadeventinitiated atHFPconditions.

Figures7.1.3-1to7-1.3-5showtheNSSSresponseforpower,heatflux,RCStemepratures, RCSpressure, andsteamgenerator pressureduringthisevent.TheZeroPowerExcessLoadeventwasinitiated attheconditions giveninTable?.1.3-3.Theh)TCandFTCvaluesassumedintheanalysisarethesameasforthefullpowercaseforthereasonspreviously given..TheminimumCEAshutdownworthavailable isconservatively assumedtobe-4.3Ãap.TheresultsoftheanalysisshowthataVariableHighPowertripoccursat44.6seconds.TheminimumDNBRcalculated duringtheeventis3..15andthepeaklinearheatgeneration rateis11.59KW/ft.FortheZP'xcessLoadevent,anSIASsignalonlowpressurizer pressureisgenerated at73.7seconds.At224.6secondsauxiliary feedwater

'flowisdelivered tobothsteamgenerators.

Theadditional positivereactivity resulting fromtheenhancedcooldownoftheRCSismitigated bythenegativereactivity insertedduetotheCEAsandtheboroninjectedviatheHPSIpumps.Thenegativereactivity addedissufficient tomaintainthecoresubcritical atalltimesafterauxiliary feedwater flowisinitiated.

The.sequence ofeventsforthezeropowercaseispresented inTable7.1.3-4.Figures7.1.3-6to7.1.3-10showtheNSSSresponseforcorepower,coreheatflux,RCStemperature, RCSpressureandsteamgenerator pressure.

ForthefullandzeropowerExcessLoadeventsinitiated byafullopeningofthesteamdumpandbypassvalves,theDNBRandCTHlimitsarenotexceeded.

Inaddition, thecoreremainssubcritical following automatic initiation oftheauxiliary feedwater flowandmanualtrippingoftheRCP'sonSIASduetolowpressurizer pressure.

Thereactivity transient duringaHFPandHZPExcessLoadeventislesslimitingthanthecorresponding SteamLineRuptureevents.

~Tab1e7.1.3-1KEYPARAMETERS ASSUMEDFORFULLPOWEREXCESSLOADEVENTANALYSISParameter InitialCorePowerLevelCoreInletTemperature ReactorCoolantSystemPressureCoreMassFlowRateModerator Temperature Coefficient CEAWorthAvailable atTripDopplerMultiplier InverseBoronWorthAuxiliary Feedwater FlowRateHighPowerLevelTripSetpointLowS.G.WaterLevelTripSetpointUnitsMWtOFpsiaxlOibm/hrx10hp/FPPM/Capibm/secX.ofFullPower~Cele327545512200133.7-2.5-4.3e85105125.4/S.G.

11229.9Reference.

CycleisFSAR.FullPower.ExcessLoadresultswerenotpresented inFSAR,therefore nocomparison ismade.

Table7.1.3-2SEQUENCEOFEVENTSFORTHEEXCESSLOADEVENTATFULLPOWERTOCALCULATE MINIMUMDNBRTime(sec)0.08.89.39.310.054.054.169.372.573.313P.5188.4600.0EventCompleteOpeningofSteamDumpandBypassValvesatFullPowerHighPowerTripSigna1Generated TripBreakersOpenCEAsBegintoDropIntoCoreMaximumPower;MaximumLinearHeatGeneration RateOccursMinimumDNBROccursSafetyInjection Actuation SignalGenerated; ManualTripofRCP'sPressurizer EmptiesRampdownofMainFeedwater FlowCompleted MainSteamIsolation SignalLowSteamGenerator LevelTripSetpointReachedIsolation ofMainFeedwater FlowtoBothSteamGenerators Auxiliary Feedwater FlowOelivered toBothSteamGenerators OperatorTerminates Auxiliary Feedwater FlowtoBothSteamGenerators SetointorValue112Koffullpower114.4Xoffullpower18.3KW(ft1.291578psia5Xoffullmain=feedwater flow578,psia29.9ft125.4lb/sectoeachsteamgenerator ttKEYPARAMETERS ASSUMEDFORHOTSTANDBYEXCESSLOADEVENTANALYSISParameter InitialCorePowerLevelCoreInletTemperature ReactorCoolantSystemPressureCoreMassFlowRateModerator Temperature Coefficient CEAWorthAvailable atTripDopplerMultiplier InverseBoronWorthVariableHighPowerTrip'Setpoint LowS.G.MaterLevel-Trip SetpointAuxiliary Feedwater FlowRateUnitsMWt0Fpsiax101bm/hr6x10hp/FXhp"'PM/Sap 5of-'-.full Powerftibm/sec~Cele55322200137.0-2.5-4.3.851004029.9125.4/S.G.

Reference CycleisFSAR..

'Table'7;l;3-'4 SEQUENCEOFEVENTSFOREXCESSLOADEVENTATHOTSTANDBYCONDITIONS TOCALCULATE MINIMUMDNBRTime(sec)0.044.645.0'5.545.6'vent SteamDumpandBypassValvesOpentoMaximumFlowCapacity.Variable HighPowerTripSignalGenerated TripBreakersOpenCEAsBegintoDropintheCoreMaximumPower;MaximumLinearHeatGeneration RateOccursSetointorValue40Koffullpower41.09Ãof.fullpower11.59KM/ft.46.167.771.173.7131.1MinimumDNBROccurs(CE-.2)Pressurizer EmptiesMainSteamIsolation SignalGenerated SafetyInjection Actuation SignalGenerated; ManualTripofReactorCoolantPumpsIsolation ofMainFeedwater FlowtoBothSteamGenerators "vvIg'3.150578psia1578psia224.6600.0Auxiliary Feedwater FlowDelivered toBothSteamGenerators OperatorTerminates Auxiliary Feedwater FlowtoBothSteamGenerators 125.4lb/sectoeachsteamgenerator 12GiGOCDFIJLLPOWERLIJSG'uJQCLi'LJ60CL.ul401GG2003GG400TINE~SECONDSSGOFLORIDAPOWER5LIGHTCOSt.LuciePlantUnit1EXCESSLOADINCIDENTCOREPOMERVSTINEFIGURE7.1.5-1 120I-1GOI-80OCFULLPOMERUJ40201GO20030040GTINE.SECONDS6GOFLORIDAPOWER8LIGHTCOeSt.LuciePlantUnit1EXCESSLOADINCIDENTHEATFLUXYSTINEFIGURE7I1I3-2

'GGFULLPOWERTOUTTAVGCY.'00Z:300TAYG=AVERAGECORECOOLANTTENPERATURE OUTCOREOUTLETTENPERATURE TINCOREINLETTENPERATURE 10001002003004GOTINESECONDSSO0S00FLORIDAPOWER8tLIGHTCO>St.LucieP1antUnit1EXCESSLOADINCIDENTTPIPERATURE YSTIYiEFIGURE~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=AVERAGECORECOOLANTTEMPERATURE TOUT=COREOUTLETTENPERATURE

'INCOREINLETTENPERATURE a'C'10G10020030040050G.600TINESECONDSFLORIDAPOWERImtLIGHTCOSt.LuciePlantUnit1EXCESSLOADINCIDENTTENPERATURE YSTINEFIGURE7.1,3-8 24CO2CGCHOTSTANDBY160012008001GG2003GQ400SGQBCGTIVE,SECQNt'5FLORIDAPOWERgLIGH'ICOsSt.LuciePlantUnit1EXCESSLOADINCIDENTREACTORCOOLANTSYSTENPRESSUREYSTINEFIGURE7e1,3-9 12001000HOTSTANDBY8006004GO0100200300400TINESECONDSS00BGGFLORIDAPOWER5'LICHTCOgSt.LucieP'tantUnit1EXCESSLOADINCIDENTNAINSTENRPRESSUREVSTINEFIGURE7,i,3-10 TheSteamGenerator TubeRupture(SGTR)eventwasreanalyzed forCycle5toverifythatthesiteboundarydoseswillnotexceedtheguidelines of10CFR100following postTMINRCrequirement tomanuallytriptheReactorCoolantPumpsonSIASduetolowpressurizer pressure.

ThedesignbasisSGTRisadoubleendedbreakofonesteamgenerator U-tube.Table3.2.3.3-1 liststhekeytransient relatedparamters usedinthisanalysis.

Intheanalysis, itisassumedthattheinitialRCS-pressureisashighas2300psia.ThisinitialRCSpressuremaximizes theamountofprimarycoolanttransported tothesecondary steamsystemsincetheleakrateisdirectlyproportional tothedifference betweentheprimaryandsecondary pressure.

Inaddition, thehigherpressurey".;-..-"'elays thelowpressurizer pressuretripwhichprolongsthetransient

.',,andtherefore maximizes thetotalprimarytosecondary massandacti.vries transport'ed.

Forthisevent,theacceptable DNBRlimitisnotexceededduetothe..actionoftheThermalMargin/Low Pressure(TM/LP)tripwhichprovides"-,a reactortriptomaintaintheDNBRabove1.30.Thetuberupturetrans'ident doesnotsignificantly affectthecorepowerdistribution.

'Therefore'">>"

thePLHGRSAFDLisnotapproached.

TheThermalMargin/Low Pressuretrip,withconservative coefficients whichaccountforthelimitingradialandaxialpeaks,maximuminlettemper'ature, RCSpressure, corepower,andconservative CEAscramcharacteristics, wouldbetheprimaryRPStripintervening duringthecourseofthetran-sient.However,tomaximizethecoo'lanttransported fromtheprimarytosecondary andthustheradioactive steamreleasestotheatmosphere, theanalysiswasperformed assumingthatthereactortripisnotinitiated un-tiltheminimumsetpoint(floor)oftheThermalMarqin/Low Pressuretrip(i.e.,LowPressurierPressureTrip)isreached.Thisprolongsthesteamreleasestotheatmosphere andthusmaximizes, thesiteboundarydoses.TheSteamGenerator TubeRupture'as analyzedforapowerlevelof2754M!(t(102/of2700Ml<t)..The'results willbeapplicable to2560Miltsincethehigheroperating powerleadstomoreconservative siteboundarydoses.Theanalysisassumesoperation of3HighPressureSafetyInjection pumps.Thisassumption leadstofasterrefilling ofthepressurizer, therefore resulting inhigherRCSpressureandthus,increasing theprimarytosecondary leak.Themethodology followedisconsistent withthemethodspreviously usedandapprovedbyNRC.Thesemethodsaredocumented inReference 3.Table3'3'-1showsthekeyparameters assumedintheanalysisoftheevent.ThesequenceofeventsfortheSGTReventwithmanualtripofRCPsispresented inTable3.2.3.3-2.

Theanalysisconservatively assumedthatat1800seconds,theoperator'nitiates cooldownbyusingtheAtmospheric DumpValves(ADV).Theanalysisdidnotcredittheuseofsteamdumpandbypasssystemtothecondenser.

Theuseofatmospheric dumpvalvesresultsinasubstantial increaseinthecalculated siteboundarydosesincetheADVpartition factoris.1comparedto.0005forthecondenser airejectors.

Figures3.2.3.3-1 through3.2.3.3-5 presentthetransient behaviorofcorepower,heatflux,RCSpressure, RCStemperatures, andsteamgenerator pressure.

I-131activityreleaseisbasedontheTechSpecallowedprimarytosecondary leakrateof1GPMandonthesteamflowrequiredtocooltheplanttocondi-tionswheretheshutdowncool,ingsystemcanbeinitiated.

Thisreleaseiscalculated astheproductof-:st'earn flow,thetimedependent steamactivityandthedecontamination factorsapplicable toeachreleasepathway.The0to2hourI-131site;boundary dose,iscalculated from:DDSE(REM)AI-131+BPx>xCFI-131where:AI-131BRx/QCFI-131I-131activityreleased.tositeboundary, Ci,breathing rate,m/sec,dispersion coefficient, sec/m,I-131doseconversion factor,Rem/Ci..Indetermining thewholebodydose,'hemajorassumption madeisthatallnoblegasesleakedthroughtherupturedtubewillbereleasedtotheatmosphere.

Therefore, thewholebodydoseisproportional tothetotalprimarytosecondary leakandiscalculated usingthefollowing equation.

i<holeBodyDose=[.25(K+-E)]*L*A*-.25gRCSg,where:EYERCSg/((averageenergyreleasebygammadecay,averageenergyreleasebybetadecay,totalprimarytosecondary masstransport noblegasactivityofprimarycoolantdi".)ii'r'n c'o<'tli<i<'nt.

~~

Theresultsoftheanalysisarethat81540lbs.ofprimarycoolantaretransported tothesteamgenerator secondary.

side.Basedonthismasstransport andvaluesinTable3.2.3.3-3, the0-2Hrsiteboundarydosescalculated are:Thyroid(DEQI-ll):0.32RENWholeBody(DEQXe-133):0.08RENThereactorprotective system(i.e.,TN/LPtrip)intervenes toprotectthecorefromexceeding theDHBRlimit.Thedo'sesresulting fromtheactivityreleasedasaconsequence ofhdouble-ended ruptureofonesteamgenerator tube,assumingthemaximumallowable TechSpecactivityfortheprimaryconcentration atacorepowerof2754NIlt,aresignificantly belowtheguidelines of10CFR100.

Thus,theresultsdonote'xceedacceptance criteria.

TABLE7.3.3-"1KEYPARAMETERS ASSUMEDIHTHESTEANGENERATOR TUBERUPTUREEYEtlTKEYTRANSIENT RELATEDPARAMETERS:

Parameter PowerMTCDopplerCoefficient Multiplier Scram1/orthinRCSPressureInitialCoreMassFlowRate(548oF,2200psia)InitialSecondary PressureUnitsxl0ap/'Fpsiax10.lb/hrDsiaFSAR2611-2.51.154.555442300117,.5841~Cele52754-2.51.15-4.0.2300133.99O2.0 g~~TABLE7.'3;3-2SEQUENCEOFEVENTSFORTHESTEAMGENERATOR TUBERUPTUREEVENTWITHRCPCOASTDOllN ONSIASTime(sec)0.0577.2577.4578.6579.1584.8587.4588.01395.41800.07859EventTubeRuptureOccursLowPressurizer PressureTripSignalGenerated DumpValvesOpenCEAsBegintoDropIntoCoreBypassValvesOpenMaximumSteamGenerator PressurePressurizer EmptiesSafetyInjection Actuation SignalGenerated; RCPsManuallyTrippedIMinimumRCSPressureOperatorIsolatesDamagedSteamGenerator andBeginsCooldownto325'FOperatorInitiates ShutdownCooling(TAVF)SetpointorValue1853psia949psia1578psia1034psia TABLE7.3.3-3ASSUMPTIONS FORTHERADIOLOGICAL EVALUATION FORTHESTEAMGEhERATOR TUBERUPTUREParameter ReactorCoolantSystemMaximumAllowable Concentration (DEQI-131)SteamGenerator MaximumAllowable Concentration (DEQI-131)1ReactorCoolantSystemMaximumAllowable Concentration of'obleGases(DEQXe-133)1Atmospheric DumpValvePartition FactorCondenser AirEjectorPartition FactorAtmospheric Dispersion Coefficient Breathing RateDoseConversion Factor(I-131)unitsyCi/gmuCi/gmpCi/gmsec/mm/secREM/CiCcle5Value1.0100/E.00058.55x10.3.47x101.48xlOTechSpeclimits.P0-2houraccidentcondition forSt.LucieUnit1.

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