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{{#Wiki_filter:CATEGORY1REGULATORYINFORMATIONDISTRIBUTIONSYSTEM(RIDS)ACCESSIONNBR:9811130285DOC.DATE:98/11/04NOTARIZED:NOFACZL:50-335St.LuciePlant,Unit1,FloridaPower6LightCo.AUTH.NAMEAUTHORAFFILIATIONFREK<FER,K.W.FloridaPower&LightCo.STALL,J.A.FloridaPower6LightCo.RECZP.NAME.RECIPIENTAFFILIATIONDOCKET05000335
{{#Wiki_filter:CATEGORY1REGULATORY INFORMATION DISTRIBUTION SYSTEM(RIDS)ACCESSION NBR:9811130285 DOC.DATE:
98/11/04NOTARIZED:
NOFACZL:50-335 St.LuciePlant,Unit1,FloridaPower6LightCo.AUTH.NAMEAUTHORAFFILIATION FREK<FER,K.W.
FloridaPower&LightCo.STALL,J.A.
FloridaPower6LightCo.RECZP.NAME
.RECIPIENT AFFILIATION DOCKET05000335


==SUBJECT:==
==SUBJECT:==
LER98-008-'00:on981008,inadequatereactorprotectionsystripbypassTSwasnoted.CausedbypoorlywordedTS.SubmittedLARtoclarifypowerrequirementsforhighrateofpowertrips.With981104ltr.DISTRIBUTIONCODE:IE22TCOPIESRECEIVED:LTRENCLSIZE:TITLE:50.73/50.9LicenseeEventReport(LER),ncidentRpt,etc.NOTES:ERECIPIENTIDCODE/NAMEPD2-3PDINTERNAL:ACRSAEOD/SPD/RRABNRR/DE/ECGBNRR/DE/EMEBNRR/DRCH/HOHBNRR/DRPM/PECBRES/DET/EIBEXTERNAL:LSTLOBBYWARDNOACPOORE,W.NRCPDRCOPIESLTTRENCL1111111111111111111111RECIPIENTZDCODE/NAMEGLEAVES,WAEOD/SPD/RABCDEEELBNRR/DRCH/HZCBNRR/DRCH/HQMBNRR/DSSA/SPLBRGN2FILE01LZTCOBRYCE,JHNOACQUEENER,DSNUDOCSFULLTXTCOPIESLTTRENCL11221111111111111'1111RD0MI'NOTETOALE"RIDS"RECIPIENTS:PLEASEHELPUSTOREDUCEWASTE.TOHAVEYOURNAMEORORGANIZATIONREMOVEDFROMDISTRIBUTIONLISTSORREDUCETHENUMBEROFCOPIESRECEIVEDBYYOUORYOURORGANIZATION,CONTACTTHEDOCUMENTCONTROLDESK(DCD)ONEXTENSION415-2083FULLTEXTCONVERSIONREQUIREDTOTAL,NUMBEROFCOPIESREQUIRED:LTTR23ENCL23 FloridaPower&LightCompany,6351S.OceanDrive,JensenBeach.FL34957APLNovember4,1998L-98-28010CFRg50.73U.S.NuclearRegulatoryCommissionAttn:DocumentControlDeskWashington,D.C.20555Re:St.LucieUnits1and2DocketNos.50-335/389ReportableEvent:1998-008-00DateofEvent:October8,1998InadequateReactorProtectionemTriBTechni1ificationh.,';",f~.~".;":".+eattachedLic&#x17d;enseeEve.'.,;j~>v>.".p~l0,CFR$50,73toprovideanttotherequirementsofntReport1998-008isbeingsubmittedpursunotificationofthesubjectevent.ia,-P~Verytrulyyours,J.A.StallVicePresidentSt.LucieNuclearPlantJAS/EJW/KWFAttachmentcc:RegionalAdministrator,USNRCRegionIISeniorResidentInspector,USNRC,St.LucieNuclearPlant98ii13028598ii04PDRAMCK05000:335SPDRanFPLGroupcompany
LER98-008-'00:on 981008,inadequate reactorprotection systripbypassTSwasnoted.CausedbypoorlywordedTS.Submitted LARtoclarifypowerrequirements forhighrateofpowertrips.With981104ltr.DISTRIBUTION CODE:IE22TCOPIESRECEIVED:LTR ENCLSIZE:TITLE:50.73/50.9 LicenseeEventReport(LER),ncidentRpt,etc.NOTES:ERECIPIENT IDCODE/NAME PD2-3PDINTERNAL:
ACRSAEOD/SPD/RRABNRR/DE/ECGB NRR/DE/EMEB NRR/DRCH/HOHB NRR/DRPM/PECB RES/DET/EIB EXTERNAL:
LSTLOBBYWARDNOACPOORE,W.NRCPDRCOPIESLTTRENCL1111111111111111111111RECIPIENT ZDCODE/NAME GLEAVES,W AEOD/SPD/RAB CDEEELBNRR/DRCH/HZCB NRR/DRCH/HQMB NRR/DSSA/SPLB RGN2FILE01LZTCOBRYCE,JHNOACQUEENER,DS NUDOCSFULLTXTCOPIESLTTRENCL11221111111111111'1111RD0MI'NOTETOALE"RIDS"RECIPIENTS:
PLEASEHELPUSTOREDUCEWASTE.TOHAVEYOURNAMEORORGANIZATION REMOVEDFROMDISTRIBUTION LISTSORREDUCETHENUMBEROFCOPIESRECEIVEDBYYOUORYOURORGANIZATION, CONTACTTHEDOCUMENTCONTROLDESK(DCD)ONEXTENSION 415-2083FULLTEXTCONVERSION REQUIREDTOTAL,NUMBEROFCOPIESREQUIRED:
LTTR23ENCL23 FloridaPower&LightCompany,6351 S.OceanDrive,JensenBeach.FL34957APLNovember4,1998L-98-28010CFRg50.73U.S.NuclearRegulatory Commission Attn:DocumentControlDeskWashington, D.C.20555Re:St.LucieUnits1and2DocketNos.50-335/389 Reportable Event:1998-008-00 DateofEvent:October8,1998Inadequate ReactorProtection emTriBTechni1ification h.,';",f~.~".;":".+e attachedLic&#x17d;ensee Eve.'.,;j~>v>
.".p~l0,CFR$
50,73toprovideanttotherequirements ofntReport1998-008isbeingsubmitted pursunotification ofthesubjectevent.ia,-P~Verytrulyyours,J.A.StallVicePresident St.LucieNuclearPlantJAS/EJW/KWF Attachment cc:RegionalAdministrator, USNRCRegionIISeniorResidentInspector, USNRC,St.LucieNuclearPlant98ii130285 98ii04PDRAMCK05000:335 SPDRanFPLGroupcompany


NRCFORM366IS-1999)U.S.NUCLEARREGULATORYCOMMISSIONLICENSEEEVENTREPORT(LER){Seereverseforrequirednumberofdigits/charactersforeachblock)APPROVEDBYOMBNO.3150.0104EXPIRES06I30l2001Estimatedburdenperresponsetocomplywiththismandalorybtfcrmagoncollecbonrequesl:50hrs.ReportedlessonslearnedareincorporatedintoIhelicensingprocessandfedbacktoIndusby.FonvardcommentsregardingburdenestimatelotheRecordsManagementBranch(TWF33),US.NudearRegulatoryCommission.Washington.DC205554001~andloIhePapenvrskRedudionProiect(31500104]OlrceofManagementandBudget,Washington.OC20503.IfaninformationcogecgondoesnoldisplayacurrentlyvalidOMBcontrolnumber,theNRCmaynotconductorsponsor,sndapersonisnolrequiredtorespondlo,thehformationcollection.FACIUTYNAME(1)St.LucieUnit1DOCKETNUMBER{2)05000335PAGE(3)Page1of4TITLE(4)InadequateReactorProtectionSystemTripBypassTechnicalSpecificationMONTHDAY10081998EVENTDATE(5LERNUMBER6REPORTDATE7)SEQUENTIALREVISIONMONTHNUMBERNUMBER1998-008-00OAY041998DOCKETNUMatn05000389DOCKETNUMSERFACIUTVNAMESt.LucieUnit2FACIUTVNAMEOTHERFACILITIESINVOLVED6OPERATINGMODE(9)POWERLEVEL{10)10020.2201(b)20.2203(a){I)20.2203(a)(2)(i)20.2203(e)(2)(ii)20.2203(a)(2)(iii)20.2203(a)(2)(iv)20.2203(e){2)(v)20.2203(a)(3)(i)20.2203(e)(3)(Ii)20.2203(a){4)50.36(c)(1)50.36(c)(2)50.73(a)(2)(i)50.73(a)(2)(ii)50.73(a)(2)(iii)50.73(a)(2)(iv)50.73(a)(2)(v)50.73{a)(2)(vii)50.73(a)(2)(viii)50.73(a)(2)(x)73.71OTHERSpecifyInAbstractbeloworInNRCForm3SSAUIREMENTSOF10CFR9:(Checkoneormoro){11)THISREPORTISSUBMITTEDPURSUANTTOTHEREQNAMEUCENSEECONTACTFORTHISLER12TELEPHONENUMBERSncludeAresCocci~K.W.Frehafer,LicensingEngineer(561)467-7748COMPLETEONELINEFOREACHCOMPONENTFAILUREDESCRIBEDINTHISREPORT13CAUSESYSTEMCOMPONENTMANUFACTURERREPORTABLETOEPIXCAUSESYSTEMCOMPONENTMANUFACTURERREPORTABLETOEPIXJCn/aN/ANO6PPTALRORTXPECTED(14)YES(IfYoe,completeEXPECTEDSUBMISSIONDATE).NOEXPECTEDSUBMISSIONDATE(15)ABSTRACT[Limitto1400spaces,ie.,approximately15singlespecedtypewrittenlines/{16)OnOctober8,1998,St.LucieUnits1and2wereinMODE1at100percentreactorpower.FPLdeterminedthattheTechnicalSpecificationgoverningthetripbypasssetpointsforthehighrateofchangeofpowerreactorprotectionsystemtripwasinerror.TheexplicittermTHERMALPOWERusedintheaffectedTechnicalSpecificationtablenotationrelativetothehighrateofchangeofpowertripbypassfunctioncannotbesatisfiedpriortoent'ryintoMODE2fromaMODE3conditionduetothenormallevelofheattransfertothereactorcoolantasaresultofreactorcoredecayheat.Thetermsofthespecificationcannotbeachievedsincedecayheatisnotadirectlymeasurableparameterandthe.operativeparameterforremovalofthebypassisexcoreneutronfluxthatismeasuredbythewiderangelogarithmicneutronfluxmonitors.Duringpastreactorstartups,literalcompliancewiththeTechnicalSpecificationsforthehighrateofchangeofpowertripwasnotmet.ThecauseofthiseventwasapoorlywordedTechnicalSpecificationthatdidnotexplicitlyexcludedecayheatfromthepowerlevelatwhichthehighrateofchangeofpowertripbypassisrequiredtoberemoved.Asacorrectiveaction,St.Luciehasdevelopedandsubmittedanamendmenttothelicensetoclarifythepowerrequirementsforthehighrateofchangeofpowertrip.Therevisionensuresthatthemeaningof'explicittermsusedintheaffectedTechnicalSpecificationsareconsistentwiththeintentofthestatedrequirementsbasedoneachSt.LuciePlantdesign.NACFORM3SSIS.1999)  
NRCFORM366IS-1999)U.S.NUCLEARREGULATORY COMMISSION LICENSEEEVENTREPORT(LER){Seereverseforrequirednumberofdigits/characters foreachblock)APPROVEDBYOMBNO.3150.0104 EXPIRES06I30l2001 Estimated burdenperresponsetocomplywiththismandalory btfcrmagon collecbon requesl:50hrs.Reportedlessonslearnedareincorporated intoIhelicensing processandfedbacktoIndusby.Fonvardcommentsregarding burdenestimatelotheRecordsManagement Branch(TWF33),US.NudearRegulatory Commission.
Washington.
DC205554001
~andloIhePapenvrsk RedudionProiect(31500104
]OlrceofManagement andBudget,Washington.
OC20503.Ifaninformation cogecgondoesnoldisplayacurrently validOMBcontrolnumber,theNRCmaynotconductorsponsor,sndapersonisnolrequiredtorespondlo,thehformation collection.
FACIUTYNAME(1)St.LucieUnit1DOCKETNUMBER{2)05000335PAGE(3)Page1of4TITLE(4)Inadequate ReactorProtection SystemTripBypassTechnical Specification MONTHDAY10081998EVENTDATE(5LERNUMBER6REPORTDATE7)SEQUENTIAL REVISIONMONTHNUMBERNUMBER1998-008-00OAY041998DOCKETNUMatn05000389DOCKETNUMSERFACIUTVNAMESt.LucieUnit2FACIUTVNAMEOTHERFACILITIES INVOLVED6OPERATING MODE(9)POWERLEVEL{10)10020.2201(b)20.2203(a)
{I)20.2203(a)(2)
(i)20.2203(e)(2)(ii)20.2203(a)(2)
(iii)20.2203(a)(2)
(iv)20.2203(e)
{2)(v)20.2203(a)(3)(i)20.2203(e)(3)
(Ii)20.2203(a)
{4)50.36(c)(1) 50.36(c)(2) 50.73(a)(2)(i)50.73(a)(2)(ii)50.73(a)(2)(iii) 50.73(a)(2)(iv)50.73(a)(2)(v)50.73{a)(2)(vii)50.73(a)(2)(viii)50.73(a)(2)(x)73.71OTHERSpecifyInAbstractbeloworInNRCForm3SSAUIREMENTS OF10CFR9:(Checkoneormoro){11)THISREPORTISSUBMITTEDPURSUANTTOTHEREQNAMEUCENSEECONTACTFORTHISLER12TELEPHONE NUMBERSncludeAresCocci~K.W.Frehafer, Licensing Engineer(561)467-7748COMPLETEONELINEFOREACHCOMPONENT FAILUREDESCRIBED INTHISREPORT13CAUSESYSTEMCOMPONENT MANUFACTURER REPORTABLE TOEPIXCAUSESYSTEMCOMPONENT MANUFACTURER REPORTABLE TOEPIXJCn/aN/ANO6PPTALRORTXPECTED(14)YES(IfYoe,completeEXPECTEDSUBMISSION DATE).NOEXPECTEDSUBMISSION DATE(15)ABSTRACT[Limitto1400spaces,ie.,approximately 15singlespeced typewritten lines/{16)OnOctober8,1998,St.LucieUnits1and2wereinMODE1at100percentreactorpower.FPLdetermined thattheTechnical Specification governing thetripbypasssetpoints forthehighrateofchangeofpowerreactorprotection systemtripwasinerror.TheexplicittermTHERMALPOWERusedintheaffectedTechnical Specification tablenotationrelativetothehighrateofchangeofpowertripbypassfunctioncannotbesatisfied priortoent'ryintoMODE2fromaMODE3condition duetothenormallevelofheattransfertothereactorcoolantasaresultofreactorcoredecayheat.Thetermsofthespecification cannotbeachievedsincedecayheatisnotadirectlymeasurable parameter andthe.operative parameter forremovalofthebypassisexcoreneutronfluxthatismeasuredbythewiderangelogarithmic neutronfluxmonitors.
Duringpastreactorstartups, literalcompliance withtheTechnical Specifications forthehighrateofchangeofpowertripwasnotmet.ThecauseofthiseventwasapoorlywordedTechnical Specification thatdidnotexplicitly excludedecayheatfromthepowerlevelatwhichthehighrateofchangeofpowertripbypassisrequiredtoberemoved.Asacorrective action,St.Luciehasdeveloped andsubmitted anamendment tothelicensetoclarifythepowerrequirements forthehighrateofchangeofpowertrip.Therevisionensuresthatthemeaningof'explicit termsusedintheaffectedTechnical Specifications areconsistent withtheintentofthestatedrequirements basedoneachSt.LuciePlantdesign.NACFORM3SSIS.1999)  


INRCFORM366AI8-I888)LICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIONFAGIUTYNAMEI1)St.LucieUnit1DocKETNUMBER205000335LERNUMBER(6)SEQUENTIALREVISIONNUMBERNUMBER1998-008-00PAGEI3)Page2of4TEXT(ffmorespeceisrequired,useedditionelcopiesofNRCForm366A/I17)DescriptionofEventOnOctober8,1998,St.LucieUnits1and2wereinMODE1at100percentreactorpower.FPLdeterminedthattheTechnicalSpecificationgoverningthetripandbypasssetpointsforthehighrateofchangeofpower(HRCP)reactorprotectionsystem(RPS)[BZISIJC]tripbypasswasinerror.Specifically,theTechnicalSpecificationincorrectlydefinestheHRCPtripbypassasafunctionofTHERMALPOWER,insteadofindicatedwiderangelogrithmicpower.Therateofchangeofreactorpowerismeasuredbyfourwiderangelogarithmicchannels.Eachchannelindependentlymonitorstheneutronfluxbyprocessingsignalsfromfissionchamberslocatedexternaltothereactorcoreandcoversatendecaderangefromapproximately10percenttoover100percentoffullpower.Theexcoreneutronfluxinthevicinityofthefissionchambersisproportionaltotheincorenuclearfissionrateandisnotsignificantlyinfluencedbyheattransferfromthecoretothecoolantfromthelong-termdecayofradioactivefissionproducts.Thelogarithmicpowerlevelsignalisdifferentiatedtoproviderateofchangeofpowerinformation.fromapproximately-1to+7decadesperminute(DPM)~TheratesignalisprocessedandinputtoabistablethatactuatestheHRCPtripwhentherateofchangeofreactorpowerexceeds2.49decadesperminute.Areactortripisinitiatedwhenreactorpowerexceedsthesetpointasmeasuredbyanytwowiderangechannels.Eachwiderangelogarithmicneutronfluxmonitoralsooperatesabistabletodisablethistripbelow10percentpowerand,conversely,ensurethatthisbypassisautomaticallyremovedatgreaterthanorequalto10percentpower.Thetripfeaturemayalsobebypassedabove15percentpower,butsettingandremovingthisbypassisaccomplishedbythepowerrangechannels(linear,narrowrangeneutronfluxmonitors)whichalsomonitortheexcoreneutronflux.TheTechnicalSpecificationsdefineTHERMALPOWERasthetotalreactorcoreheattransferratetothereactorcoolant.Inadditiontotheheatgeneratedbytheincorefissionrate,thisdefinitionofTHERMALPOWBRincludesdecayheatwhichisproducedfromtheradioactivedecayofcorefissionproducts.Forapreviouslyoperatedreactor,decayheatcontinuestoexistduringreactorshutdownandwouldtakeseveralyearstodecaytoalevelwherethecoreheattransferratecorrespondsto10percent,orless,ofRATEDTHERMALPOWER.Decay'heatisnotadirectlymeasureableparameter,doesnotreflectthereactivityconditionofthereactor,andisnotavariablenormallyassociatedwiththerateofchangeofreactorpower.Therefore,decayheatisnotsuitableforuseasanoperativeparameterforautomaticprotectiveactionsandthereisnoevidencetoindicatethatdecayheatwasconsideredinthedesignoftheHRCPtripfunction.CauseoftheEventThecauseofthiseventwasapoorlywordedTechnicalSpecificationthatdidnotexplicitlyexcludedecayheatfromthepowerlevelatwhichtheHRCPtripbypassisrequiredtoberemoved.AnalysisoftheEvent,Thiseventisreportableunder10CFR50.73(a)(2)(i)(B)as"anyoperationorconditionprohibitedbytheplant'sTechnicalSpecifications."ThefollowingNRCFORM388A(8.1888)
INRCFORM366AI8-I888)LICENSEEEVENTREPORT(LER)TEXTCONTINUATION U.S.NUCLEARREGULATORY COMMISSION FAGIUTYNAMEI1)St.LucieUnit1DocKETNUMBER205000335LERNUMBER(6)SEQUENTIAL REVISIONNUMBERNUMBER1998-008-00PAGEI3)Page2of4TEXT(ffmorespeceisrequired, useedditionelcopiesofNRCForm366A/I17)Description ofEventOnOctober8,1998,St.LucieUnits1and2wereinMODE1at100percentreactorpower.FPLdetermined thattheTechnical Specification governing thetripandbypasssetpoints forthehighrateofchangeofpower(HRCP)reactorprotection system(RPS)[BZISIJC]
NRCFDRM366A(6-1998)LlCENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIONFACILITYNAME(1)St.LucieUnit1DOCKETNUMBER(2)05000335LERNUMBER(8)SEQUENTIALREVISION'UMBERNUMBER1998-008-00PAGE(3)Page3of4TEXT(ifmorespeceisrequired,useedditionelcopiesofiIfRCForm366AI(17)FTechnicalSpecificationtablenotationsapplytothewiderangelogarithmicneutronfluxmonitorfunctionalunit:ForbothUnits:TS1.25:RATEDTHERMALPOWERshallbeatotalreactorcoreheattransferratetothereactorcoolantof2700MWt.TS1.33:THERMALPOWERshallbethetotalreactorcoreheattransferratetothereactorcoolant.TS1.20,OPERATZOMALMODE:AnOPBRATZOHALMODE(i.e.,MODE)shallcorrespondtoanyoneinclusivecombinationofcorereactivitycondition,powerlevel,andaveragereactorcoolanttemperaturespecifiedinTSTable1'.ZnTABLE1.2,theterm0RATEDTHERMALPOWERismodifiedwithafootnotethatstates,*Excludingdecayheat.Unit1:TABLE2.2-1,NOTE(4):Tripmaybebypassedbelow10%andabove15%ofRATEDTHERMALPOWERTABLE3.3-1,Note(d):Tripmaybebypassedbelow100andabove15%ofRATEDTHERMALPOWER)bypassshallbeautomaticallyremovedwhenTHERMALpowerisabove100orbelow15%ofRATEDTHBRKQPOWBR.Unit2:TABLE2.2-2,NOTE(4)andTABLE3.3-7,NOTE(e):Tripmaybebypassedbelow10andabove15%.ofRATEDTHERMALPOWBR;bypassshallbeautomaticallyremovedwhenTHERMALpowerisabove10%orbelow15%ofRATBDTHERMALPOWER.TheHRCPtripwasprovidedwiththeSt.LucieUnit1andUnit2analogRPSas"backupprotectionagainstpowerexcursioneventsinitiatedfromsubcriticalconditions.Thetripisrequiredtobeoperablei.nModes1and2,butmaybebypassedbelow10percentandabove15percentofreactorpower.Assuch,thetripisbasedonboththeOPBRATZONALMODBofthereactorandonhowfastthemeasuredparameterrepresentingreactorpowerchangesinagiventimeperiod.Thesetpointisspecifiedinunitsofreactorstartuprate,i.e.,indecadesperminute(DPM).Thestartuprateisobtainedfromthewiderangelogarithmicneutronfluxmonitorswhichmonitortheexcoreneutronflux.Theexcoreneutronfluxisproportionaltotheincorefissionrate,andtherefore,isproportionaltothereactorpowerproducedfromtheincorefissionrate.Duringstartupofacommercialnuclearreactorfromsubcriticalconditions,heattransfertothereactorcoolantasaresultofonlythefissionrateistypicallyinsufficienttosignificantlyaffectthereactorcoolanttemperaturewhenlessthanapproximately0.1percentoffullpowerandtherateofchangeofneutronfluxisessentiallytheonlymeasureableparameterthatprovidesrateofchangeofpowerinformation.Table1.2ofthefacilityTechnicalSpecificationsdefinestheOPBRATZOHALMODBSofplantoperationintermsofreactivity,thermalpower,andaveragecoolanttemperature.ThetermpercentRATEDTHERMALPOWERisclearlyannotatedandfootnotedwithanasterisktoclarifythatthenumericalvaluesusedinthetableexcludedecayheat.Thisexclusionappliestothepowerlevelthat,inpart,definesMODE2whereintheHRCPtripisrequiredtobeoperableduringreactorstartup.NAGFOAM386A(6-1998)
tripbypasswasinerror.Specifically, theTechnical Specification incorrectly definestheHRCPtripbypassasafunctionofTHERMALPOWER,insteadofindicated widerangelogrithmic power.Therateofchangeofreactorpowerismeasuredbyfourwiderangelogarithmic channels.
NRCFORM366A18-1998)LICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCUARREGULATORYCOMMlSSlONFACIUTYNAMEt1)0OCKETNUMBER2lt.ERNUMBER(6)PAGE(3)St.LucieUnit1SEQUENTIALREVISIONNUMBERNUMBER050003351998-008-00Page4of4TEXTllfmorespecsisreguired,useedditionelcopiesofNRCFerm36&i/I17)TheuseofexcoreneutronfluxasthemeasuredparametertoimplementtheHRCPtripfunctionisappropriate,andtheRPSnuclearinstrumentationchannelsdesignedtocoverthestartuprangesoftheSt.Luciereactorsarethewiderangelogarithmicneutronfluxmonitors.Similartodesignfeaturesofthetrip,thepowerlevelatwhichthetripfunctionbypassmustberemovedduringareactorstartupisassociatedwiththeOPERATIONALMODBofthereactorandmustbeinarangeofreactorpowerthatwillassuresuccessoftheprotectiveaction.TheonsetofoperabilityfortheHRCPtripinMODE2duringstartupisatanexcoreneutronfluxthatcorrespondstoapproximately10percentoftheincorefull-powerfissionrate.However,thethermalpowerproducedfromthisfissionrateistypicallybelowtheTHEMQPOWERdefinedbyTS1.33which,absentanexplicitmodifiertoindicateotherwise,includesdecayheat.IntheSt.LuciereactorsfollowingshutdownfromextendedpoweroperationstobelowMODE2,thethermalpowerproducedfromdecayheatistypicallyhigherthanthethermalpowerproducedonlybythefi.ssionrate.AlthoughtheexclusionofdecayheatfromtheHRCptripisimpliedbythedefinitionofOPERATIONALMODE,literalcompliancewiththeTechnicalSpecificationrequirementsfordefiningtheHRCPtripbypasssetpointasafunctionofTHERMALPOWERwasnotmet.AnalysisofSafetySignificanceTheTechnicalSpecificationinadequacydoesnotapplyduringshutdownreactoroperationsorMODB1reactoroperationabove15percentpower.Currently,bothSt.LucieunitsareoperatinginMIODE1above15percentpower,sonocurrentTechnicalSpecificationcomplianceissueexists.Duringpastreactorstartups,literalcompliancewiththeTechnicalSpecificationsfortheHRCPtripwasnotmet.However,thedesignoftheHRCPtripfunctionanditsautomaticbypassremovalfeatureareassociatedwiththereactorpowergeneratedonlybythefissionprocessandexcludesconsiderationofdecayheat.Decayheatisnotadirectlymeasureableparameter,doesnotreflectthereactivityconditionofthereactor,andisnotavariablenormallyassociatedwiththerateofchangeofreactorpower.Therefore,thehealthandsafetyofthepublicwerenotaffectedbythisevent.CorrectiveActions1.St.Luciehasdevelopedandsubmittedanamendmenttothelicensestoclarifythepowerrequirementsforthe'HRCPtrip.TheTechni.calSpecificationchangeswillneedtobeapprovedbytheNRCpriortoanysubsequentunitstartup.2.FPLreviewedtheTechnicalSpecificationsgoverningtheautomaticremovalof,andpermissivesfor,otherRPStripbypassesfortheincorrectuseofTHERMALPOWERanddecayheat.Thelicenseamendmentssubmittedinaction(1)abovealsoreplacesthetermTHERMALPOWERwiththepowermeasuredbytheappropriateneutronfluxmonitorforthetripbypassesassociatedwiththeRPSzeropowermodebypass,localpowerdensitytripbypass,andturbinetripbypass.AdditionalInformationNoneNRCFORM3BBA18-1998)}}
Eachchannelindependently monitorstheneutronfluxbyprocessing signalsfromfissionchamberslocatedexternaltothereactorcoreandcoversatendecaderangefromapproximately 10percenttoover100percentoffullpower.Theexcoreneutronfluxinthevicinityofthefissionchambersisproportional totheincorenuclearfissionrateandisnotsignificantly influenced byheattransferfromthecoretothecoolantfromthelong-term decayofradioactive fissionproducts.
Thelogarithmic powerlevelsignalisdifferentiated toproviderateofchangeofpowerinformation.
fromapproximately
-1to+7decadesperminute(DPM)~Theratesignalisprocessed andinputtoabistablethatactuatestheHRCPtripwhentherateofchangeofreactorpowerexceeds2.49decadesperminute.Areactortripisinitiated whenreactorpowerexceedsthesetpointasmeasuredbyanytwowiderangechannels.
Eachwiderangelogarithmic neutronfluxmonitoralsooperatesabistabletodisablethistripbelow10percentpowerand,conversely, ensurethatthisbypassisautomatically removedatgreaterthanorequalto10percentpower.Thetripfeaturemayalsobebypassedabove15percentpower,butsettingandremovingthisbypassisaccomplished bythepowerrangechannels(linear,narrowrangeneutronfluxmonitors) whichalsomonitortheexcoreneutronflux.TheTechnical Specifications defineTHERMALPOWERasthetotalreactorcoreheattransferratetothereactorcoolant.Inadditiontotheheatgenerated bytheincorefissionrate,thisdefinition ofTHERMALPOWBRincludesdecayheatwhichisproducedfromtheradioactive decayofcorefissionproducts.
Forapreviously operatedreactor,decayheatcontinues toexistduringreactorshutdownandwouldtakeseveralyearstodecaytoalevelwherethecoreheattransferratecorresponds to10percent,orless,ofRATEDTHERMALPOWER.Decay'heat isnotadirectlymeasureable parameter, doesnotreflectthereactivity condition ofthereactor,andisnotavariablenormallyassociated withtherateofchangeofreactorpower.Therefore, decayheatisnotsuitableforuseasanoperative parameter forautomatic protective actionsandthereisnoevidencetoindicatethatdecayheatwasconsidered inthedesignoftheHRCPtripfunction.
CauseoftheEventThecauseofthiseventwasapoorlywordedTechnical Specification thatdidnotexplicitly excludedecayheatfromthepowerlevelatwhichtheHRCPtripbypassisrequiredtoberemoved.AnalysisoftheEvent,Thiseventisreportable under10CFR50.73(a)(2)(i)(B) as"anyoperation orcondition prohibited bytheplant'sTechnical Specifications."
Thefollowing NRCFORM388A(8.1888)
NRCFDRM366A(6-1998)LlCENSEEEVENTREPORT(LER)TEXTCONTINUATION U.S.NUCLEARREGULATORY COMMISSION FACILITYNAME(1)St.LucieUnit1DOCKETNUMBER(2)05000335LERNUMBER(8)SEQUENTIAL REVISION'UMBERNUMBER1998-008-00PAGE(3)Page3of4TEXT(ifmorespeceisrequired, useedditionel copiesofiIfRCForm366AI(17)FTechnical Specification tablenotations applytothewiderangelogarithmic neutronfluxmonitorfunctional unit:ForbothUnits:TS1.25:RATEDTHERMALPOWERshallbeatotalreactorcoreheattransferratetothereactorcoolantof2700MWt.TS1.33:THERMALPOWERshallbethetotalreactorcoreheattransferratetothereactorcoolant.TS1.20,OPERATZOMAL MODE:AnOPBRATZOHAL MODE(i.e.,MODE)shallcorrespond toanyoneinclusive combination ofcorereactivity condition, powerlevel,andaveragereactorcoolanttemperature specified inTSTable1'.ZnTABLE1.2,theterm0RATEDTHERMALPOWERismodifiedwithafootnotethatstates,*Excluding decayheat.Unit1:TABLE2.2-1,NOTE(4):Tripmaybebypassedbelow10%andabove15%ofRATEDTHERMALPOWERTABLE3.3-1,Note(d):Tripmaybebypassedbelow100andabove15%ofRATEDTHERMALPOWER)bypassshallbeautomatically removedwhenTHERMALpowerisabove100orbelow15%ofRATEDTHBRKQPOWBR.Unit2:TABLE2.2-2,NOTE(4)andTABLE3.3-7,NOTE(e):Tripmaybebypassedbelow10andabove15%.ofRATEDTHERMALPOWBR;bypassshallbeautomatically removedwhenTHERMALpowerisabove10%orbelow15%ofRATBDTHERMALPOWER.TheHRCPtripwasprovidedwiththeSt.LucieUnit1andUnit2analogRPSas"backupprotection againstpowerexcursion eventsinitiated fromsubcritical conditions.
Thetripisrequiredtobeoperablei.nModes1and2,butmaybebypassedbelow10percentandabove15percentofreactorpower.Assuch,thetripisbasedonboththeOPBRATZONAL MODBofthereactorandonhowfastthemeasuredparameter representing reactorpowerchangesinagiventimeperiod.Thesetpointisspecified inunitsofreactorstartuprate,i.e.,indecadesperminute(DPM).Thestartuprateisobtainedfromthewiderangelogarithmic neutronfluxmonitorswhichmonitortheexcoreneutronflux.Theexcoreneutronfluxisproportional totheincorefissionrate,andtherefore, isproportional tothereactorpowerproducedfromtheincorefissionrate.Duringstartupofacommercial nuclearreactorfromsubcritical conditions, heattransfertothereactorcoolantasaresultofonlythefissionrateistypically insufficient tosignificantly affectthereactorcoolanttemperature whenlessthanapproximately 0.1percentoffullpowerandtherateofchangeofneutronfluxisessentially theonlymeasureable parameter thatprovidesrateofchangeofpowerinformation.
Table1.2ofthefacilityTechnical Specifications definestheOPBRATZOHAL MODBSofplantoperation intermsofreactivity, thermalpower,andaveragecoolanttemperature.
ThetermpercentRATEDTHERMALPOWERisclearlyannotated andfootnoted withanasterisktoclarifythatthenumerical valuesusedinthetableexcludedecayheat.Thisexclusion appliestothepowerlevelthat,inpart,definesMODE2whereintheHRCPtripisrequiredtobeoperableduringreactorstartup.NAGFOAM386A(6-1998)
NRCFORM366A18-1998)LICENSEEEVENTREPORT(LER)TEXTCONTINUATION U.S.NUCUARREGULATORY COMMlSSlON FACIUTYNAMEt1)0OCKETNUMBER2lt.ERNUMBER(6)PAGE(3)St.LucieUnit1SEQUENTIAL REVISIONNUMBERNUMBER050003351998-008-00Page4of4TEXTllfmorespecsisreguired, useedditionel copiesofNRCFerm36&i/I17)Theuseofexcoreneutronfluxasthemeasuredparameter toimplement theHRCPtripfunctionisappropriate, andtheRPSnuclearinstrumentation channelsdesignedtocoverthestartuprangesoftheSt.Luciereactorsarethewiderangelogarithmic neutronfluxmonitors.
Similartodesignfeaturesofthetrip,thepowerlevelatwhichthetripfunctionbypassmustberemovedduringareactorstartupisassociated withtheOPERATIONAL MODBofthereactorandmustbeinarangeofreactorpowerthatwillassuresuccessoftheprotective action.Theonsetofoperability fortheHRCPtripinMODE2duringstartupisatanexcoreneutronfluxthatcorresponds toapproximately 10percentoftheincorefull-power fissionrate.However,thethermalpowerproducedfromthisfissionrateistypically belowtheTHEMQPOWERdefinedbyTS1.33which,absentanexplicitmodifiertoindicateotherwise, includesdecayheat.IntheSt.Luciereactorsfollowing shutdownfromextendedpoweroperations tobelowMODE2,thethermalpowerproducedfromdecayheatistypically higherthanthethermalpowerproducedonlybythefi.ssionrate.Althoughtheexclusion ofdecayheatfromtheHRCptripisimpliedbythedefinition ofOPERATIONAL MODE,literalcompliance withtheTechnical Specification requirements fordefiningtheHRCPtripbypasssetpointasafunctionofTHERMALPOWERwasnotmet.AnalysisofSafetySignificance TheTechnical Specification inadequacy doesnotapplyduringshutdownreactoroperations orMODB1reactoroperation above15percentpower.Currently, bothSt.Lucieunitsareoperating inMIODE1above15percentpower,sonocurrentTechnical Specification compliance issueexists.Duringpastreactorstartups, literalcompliance withtheTechnical Specifications fortheHRCPtripwasnotmet.However,thedesignoftheHRCPtripfunctionanditsautomatic bypassremovalfeatureareassociated withthereactorpowergenerated onlybythefissionprocessandexcludesconsideration ofdecayheat.Decayheatisnotadirectlymeasureable parameter, doesnotreflectthereactivity condition ofthereactor,andisnotavariablenormallyassociated withtherateofchangeofreactorpower.Therefore, thehealthandsafetyofthepublicwerenotaffectedbythisevent.Corrective Actions1.St.Luciehasdeveloped andsubmitted anamendment tothelicensestoclarifythepowerrequirements forthe'HRCPtrip.TheTechni.cal Specification changeswillneedtobeapprovedbytheNRCpriortoanysubsequent unitstartup.2.FPLreviewedtheTechnical Specifications governing theautomatic removalof,andpermissives for,otherRPStripbypassesfortheincorrect useofTHERMALPOWERanddecayheat.Thelicenseamendments submitted inaction(1)abovealsoreplacesthetermTHERMALPOWERwiththepowermeasuredbytheappropriate neutronfluxmonitorforthetripbypassesassociated withtheRPSzeropowermodebypass,localpowerdensitytripbypass,andturbinetripbypass.Additional Information NoneNRCFORM3BBA18-1998)}}

Revision as of 14:34, 29 June 2018

LER 98-008-00:on 981008,inadequate Reactor Protection Sys Trip Bypass TS Was Noted.Caused by Poorly Worded Ts. Submitted LAR to Clarify Power Requirements for High Rate of Power Trips.With 981104 Ltr
ML17229A902
Person / Time
Site: Saint Lucie NextEra Energy icon.png
Issue date: 11/04/1998
From: FREHAFER K W, STALL J A
FLORIDA POWER & LIGHT CO.
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
L-98-280, LER-98-008, LER-98-8, NUDOCS 9811130285
Download: ML17229A902 (8)
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Text

CATEGORY1REGULATORY INFORMATION DISTRIBUTION SYSTEM(RIDS)ACCESSION NBR:9811130285 DOC.DATE:

98/11/04NOTARIZED:

NOFACZL:50-335 St.LuciePlant,Unit1,FloridaPower6LightCo.AUTH.NAMEAUTHORAFFILIATION FREK<FER,K.W.

FloridaPower&LightCo.STALL,J.A.

FloridaPower6LightCo.RECZP.NAME

.RECIPIENT AFFILIATION DOCKET05000335

SUBJECT:

LER98-008-'00:on 981008,inadequate reactorprotection systripbypassTSwasnoted.CausedbypoorlywordedTS.Submitted LARtoclarifypowerrequirements forhighrateofpowertrips.With981104ltr.DISTRIBUTION CODE:IE22TCOPIESRECEIVED:LTR ENCLSIZE:TITLE:50.73/50.9 LicenseeEventReport(LER),ncidentRpt,etc.NOTES:ERECIPIENT IDCODE/NAME PD2-3PDINTERNAL:

ACRSAEOD/SPD/RRABNRR/DE/ECGB NRR/DE/EMEB NRR/DRCH/HOHB NRR/DRPM/PECB RES/DET/EIB EXTERNAL:

LSTLOBBYWARDNOACPOORE,W.NRCPDRCOPIESLTTRENCL1111111111111111111111RECIPIENT ZDCODE/NAME GLEAVES,W AEOD/SPD/RAB CDEEELBNRR/DRCH/HZCB NRR/DRCH/HQMB NRR/DSSA/SPLB RGN2FILE01LZTCOBRYCE,JHNOACQUEENER,DS NUDOCSFULLTXTCOPIESLTTRENCL11221111111111111'1111RD0MI'NOTETOALE"RIDS"RECIPIENTS:

PLEASEHELPUSTOREDUCEWASTE.TOHAVEYOURNAMEORORGANIZATION REMOVEDFROMDISTRIBUTION LISTSORREDUCETHENUMBEROFCOPIESRECEIVEDBYYOUORYOURORGANIZATION, CONTACTTHEDOCUMENTCONTROLDESK(DCD)ONEXTENSION 415-2083FULLTEXTCONVERSION REQUIREDTOTAL,NUMBEROFCOPIESREQUIRED:

LTTR23ENCL23 FloridaPower&LightCompany,6351 S.OceanDrive,JensenBeach.FL34957APLNovember4,1998L-98-28010CFRg50.73U.S.NuclearRegulatory Commission Attn:DocumentControlDeskWashington, D.C.20555Re:St.LucieUnits1and2DocketNos.50-335/389 Reportable Event:1998-008-00 DateofEvent:October8,1998Inadequate ReactorProtection emTriBTechni1ification h.,';",f~.~".;":".+e attachedLicŽensee Eve.'.,;j~>v>

.".p~l0,CFR$

50,73toprovideanttotherequirements ofntReport1998-008isbeingsubmitted pursunotification ofthesubjectevent.ia,-P~Verytrulyyours,J.A.StallVicePresident St.LucieNuclearPlantJAS/EJW/KWF Attachment cc:RegionalAdministrator, USNRCRegionIISeniorResidentInspector, USNRC,St.LucieNuclearPlant98ii130285 98ii04PDRAMCK05000:335 SPDRanFPLGroupcompany

NRCFORM366IS-1999)U.S.NUCLEARREGULATORY COMMISSION LICENSEEEVENTREPORT(LER){Seereverseforrequirednumberofdigits/characters foreachblock)APPROVEDBYOMBNO.3150.0104 EXPIRES06I30l2001 Estimated burdenperresponsetocomplywiththismandalory btfcrmagon collecbon requesl:50hrs.Reportedlessonslearnedareincorporated intoIhelicensing processandfedbacktoIndusby.Fonvardcommentsregarding burdenestimatelotheRecordsManagement Branch(TWF33),US.NudearRegulatory Commission.

Washington.

DC205554001

~andloIhePapenvrsk RedudionProiect(31500104

]OlrceofManagement andBudget,Washington.

OC20503.Ifaninformation cogecgondoesnoldisplayacurrently validOMBcontrolnumber,theNRCmaynotconductorsponsor,sndapersonisnolrequiredtorespondlo,thehformation collection.

FACIUTYNAME(1)St.LucieUnit1DOCKETNUMBER{2)05000335PAGE(3)Page1of4TITLE(4)Inadequate ReactorProtection SystemTripBypassTechnical Specification MONTHDAY10081998EVENTDATE(5LERNUMBER6REPORTDATE7)SEQUENTIAL REVISIONMONTHNUMBERNUMBER1998-008-00OAY041998DOCKETNUMatn05000389DOCKETNUMSERFACIUTVNAMESt.LucieUnit2FACIUTVNAMEOTHERFACILITIES INVOLVED6OPERATING MODE(9)POWERLEVEL{10)10020.2201(b)20.2203(a)

{I)20.2203(a)(2)

(i)20.2203(e)(2)(ii)20.2203(a)(2)

(iii)20.2203(a)(2)

(iv)20.2203(e)

{2)(v)20.2203(a)(3)(i)20.2203(e)(3)

(Ii)20.2203(a)

{4)50.36(c)(1) 50.36(c)(2) 50.73(a)(2)(i)50.73(a)(2)(ii)50.73(a)(2)(iii) 50.73(a)(2)(iv)50.73(a)(2)(v)50.73{a)(2)(vii)50.73(a)(2)(viii)50.73(a)(2)(x)73.71OTHERSpecifyInAbstractbeloworInNRCForm3SSAUIREMENTS OF10CFR9:(Checkoneormoro){11)THISREPORTISSUBMITTEDPURSUANTTOTHEREQNAMEUCENSEECONTACTFORTHISLER12TELEPHONE NUMBERSncludeAresCocci~K.W.Frehafer, Licensing Engineer(561)467-7748COMPLETEONELINEFOREACHCOMPONENT FAILUREDESCRIBED INTHISREPORT13CAUSESYSTEMCOMPONENT MANUFACTURER REPORTABLE TOEPIXCAUSESYSTEMCOMPONENT MANUFACTURER REPORTABLE TOEPIXJCn/aN/ANO6PPTALRORTXPECTED(14)YES(IfYoe,completeEXPECTEDSUBMISSION DATE).NOEXPECTEDSUBMISSION DATE(15)ABSTRACT[Limitto1400spaces,ie.,approximately 15singlespeced typewritten lines/{16)OnOctober8,1998,St.LucieUnits1and2wereinMODE1at100percentreactorpower.FPLdetermined thattheTechnical Specification governing thetripbypasssetpoints forthehighrateofchangeofpowerreactorprotection systemtripwasinerror.TheexplicittermTHERMALPOWERusedintheaffectedTechnical Specification tablenotationrelativetothehighrateofchangeofpowertripbypassfunctioncannotbesatisfied priortoent'ryintoMODE2fromaMODE3condition duetothenormallevelofheattransfertothereactorcoolantasaresultofreactorcoredecayheat.Thetermsofthespecification cannotbeachievedsincedecayheatisnotadirectlymeasurable parameter andthe.operative parameter forremovalofthebypassisexcoreneutronfluxthatismeasuredbythewiderangelogarithmic neutronfluxmonitors.

Duringpastreactorstartups, literalcompliance withtheTechnical Specifications forthehighrateofchangeofpowertripwasnotmet.ThecauseofthiseventwasapoorlywordedTechnical Specification thatdidnotexplicitly excludedecayheatfromthepowerlevelatwhichthehighrateofchangeofpowertripbypassisrequiredtoberemoved.Asacorrective action,St.Luciehasdeveloped andsubmitted anamendment tothelicensetoclarifythepowerrequirements forthehighrateofchangeofpowertrip.Therevisionensuresthatthemeaningof'explicit termsusedintheaffectedTechnical Specifications areconsistent withtheintentofthestatedrequirements basedoneachSt.LuciePlantdesign.NACFORM3SSIS.1999)

INRCFORM366AI8-I888)LICENSEEEVENTREPORT(LER)TEXTCONTINUATION U.S.NUCLEARREGULATORY COMMISSION FAGIUTYNAMEI1)St.LucieUnit1DocKETNUMBER205000335LERNUMBER(6)SEQUENTIAL REVISIONNUMBERNUMBER1998-008-00PAGEI3)Page2of4TEXT(ffmorespeceisrequired, useedditionelcopiesofNRCForm366A/I17)Description ofEventOnOctober8,1998,St.LucieUnits1and2wereinMODE1at100percentreactorpower.FPLdetermined thattheTechnical Specification governing thetripandbypasssetpoints forthehighrateofchangeofpower(HRCP)reactorprotection system(RPS)[BZISIJC]

tripbypasswasinerror.Specifically, theTechnical Specification incorrectly definestheHRCPtripbypassasafunctionofTHERMALPOWER,insteadofindicated widerangelogrithmic power.Therateofchangeofreactorpowerismeasuredbyfourwiderangelogarithmic channels.

Eachchannelindependently monitorstheneutronfluxbyprocessing signalsfromfissionchamberslocatedexternaltothereactorcoreandcoversatendecaderangefromapproximately 10percenttoover100percentoffullpower.Theexcoreneutronfluxinthevicinityofthefissionchambersisproportional totheincorenuclearfissionrateandisnotsignificantly influenced byheattransferfromthecoretothecoolantfromthelong-term decayofradioactive fissionproducts.

Thelogarithmic powerlevelsignalisdifferentiated toproviderateofchangeofpowerinformation.

fromapproximately

-1to+7decadesperminute(DPM)~Theratesignalisprocessed andinputtoabistablethatactuatestheHRCPtripwhentherateofchangeofreactorpowerexceeds2.49decadesperminute.Areactortripisinitiated whenreactorpowerexceedsthesetpointasmeasuredbyanytwowiderangechannels.

Eachwiderangelogarithmic neutronfluxmonitoralsooperatesabistabletodisablethistripbelow10percentpowerand,conversely, ensurethatthisbypassisautomatically removedatgreaterthanorequalto10percentpower.Thetripfeaturemayalsobebypassedabove15percentpower,butsettingandremovingthisbypassisaccomplished bythepowerrangechannels(linear,narrowrangeneutronfluxmonitors) whichalsomonitortheexcoreneutronflux.TheTechnical Specifications defineTHERMALPOWERasthetotalreactorcoreheattransferratetothereactorcoolant.Inadditiontotheheatgenerated bytheincorefissionrate,thisdefinition ofTHERMALPOWBRincludesdecayheatwhichisproducedfromtheradioactive decayofcorefissionproducts.

Forapreviously operatedreactor,decayheatcontinues toexistduringreactorshutdownandwouldtakeseveralyearstodecaytoalevelwherethecoreheattransferratecorresponds to10percent,orless,ofRATEDTHERMALPOWER.Decay'heat isnotadirectlymeasureable parameter, doesnotreflectthereactivity condition ofthereactor,andisnotavariablenormallyassociated withtherateofchangeofreactorpower.Therefore, decayheatisnotsuitableforuseasanoperative parameter forautomatic protective actionsandthereisnoevidencetoindicatethatdecayheatwasconsidered inthedesignoftheHRCPtripfunction.

CauseoftheEventThecauseofthiseventwasapoorlywordedTechnical Specification thatdidnotexplicitly excludedecayheatfromthepowerlevelatwhichtheHRCPtripbypassisrequiredtoberemoved.AnalysisoftheEvent,Thiseventisreportable under10CFR50.73(a)(2)(i)(B) as"anyoperation orcondition prohibited bytheplant'sTechnical Specifications."

Thefollowing NRCFORM388A(8.1888)

NRCFDRM366A(6-1998)LlCENSEEEVENTREPORT(LER)TEXTCONTINUATION U.S.NUCLEARREGULATORY COMMISSION FACILITYNAME(1)St.LucieUnit1DOCKETNUMBER(2)05000335LERNUMBER(8)SEQUENTIAL REVISION'UMBERNUMBER1998-008-00PAGE(3)Page3of4TEXT(ifmorespeceisrequired, useedditionel copiesofiIfRCForm366AI(17)FTechnical Specification tablenotations applytothewiderangelogarithmic neutronfluxmonitorfunctional unit:ForbothUnits:TS1.25:RATEDTHERMALPOWERshallbeatotalreactorcoreheattransferratetothereactorcoolantof2700MWt.TS1.33:THERMALPOWERshallbethetotalreactorcoreheattransferratetothereactorcoolant.TS1.20,OPERATZOMAL MODE:AnOPBRATZOHAL MODE(i.e.,MODE)shallcorrespond toanyoneinclusive combination ofcorereactivity condition, powerlevel,andaveragereactorcoolanttemperature specified inTSTable1'.ZnTABLE1.2,theterm0RATEDTHERMALPOWERismodifiedwithafootnotethatstates,*Excluding decayheat.Unit1:TABLE2.2-1,NOTE(4):Tripmaybebypassedbelow10%andabove15%ofRATEDTHERMALPOWERTABLE3.3-1,Note(d):Tripmaybebypassedbelow100andabove15%ofRATEDTHERMALPOWER)bypassshallbeautomatically removedwhenTHERMALpowerisabove100orbelow15%ofRATEDTHBRKQPOWBR.Unit2:TABLE2.2-2,NOTE(4)andTABLE3.3-7,NOTE(e):Tripmaybebypassedbelow10andabove15%.ofRATEDTHERMALPOWBR;bypassshallbeautomatically removedwhenTHERMALpowerisabove10%orbelow15%ofRATBDTHERMALPOWER.TheHRCPtripwasprovidedwiththeSt.LucieUnit1andUnit2analogRPSas"backupprotection againstpowerexcursion eventsinitiated fromsubcritical conditions.

Thetripisrequiredtobeoperablei.nModes1and2,butmaybebypassedbelow10percentandabove15percentofreactorpower.Assuch,thetripisbasedonboththeOPBRATZONAL MODBofthereactorandonhowfastthemeasuredparameter representing reactorpowerchangesinagiventimeperiod.Thesetpointisspecified inunitsofreactorstartuprate,i.e.,indecadesperminute(DPM).Thestartuprateisobtainedfromthewiderangelogarithmic neutronfluxmonitorswhichmonitortheexcoreneutronflux.Theexcoreneutronfluxisproportional totheincorefissionrate,andtherefore, isproportional tothereactorpowerproducedfromtheincorefissionrate.Duringstartupofacommercial nuclearreactorfromsubcritical conditions, heattransfertothereactorcoolantasaresultofonlythefissionrateistypically insufficient tosignificantly affectthereactorcoolanttemperature whenlessthanapproximately 0.1percentoffullpowerandtherateofchangeofneutronfluxisessentially theonlymeasureable parameter thatprovidesrateofchangeofpowerinformation.

Table1.2ofthefacilityTechnical Specifications definestheOPBRATZOHAL MODBSofplantoperation intermsofreactivity, thermalpower,andaveragecoolanttemperature.

ThetermpercentRATEDTHERMALPOWERisclearlyannotated andfootnoted withanasterisktoclarifythatthenumerical valuesusedinthetableexcludedecayheat.Thisexclusion appliestothepowerlevelthat,inpart,definesMODE2whereintheHRCPtripisrequiredtobeoperableduringreactorstartup.NAGFOAM386A(6-1998)

NRCFORM366A18-1998)LICENSEEEVENTREPORT(LER)TEXTCONTINUATION U.S.NUCUARREGULATORY COMMlSSlON FACIUTYNAMEt1)0OCKETNUMBER2lt.ERNUMBER(6)PAGE(3)St.LucieUnit1SEQUENTIAL REVISIONNUMBERNUMBER050003351998-008-00Page4of4TEXTllfmorespecsisreguired, useedditionel copiesofNRCFerm36&i/I17)Theuseofexcoreneutronfluxasthemeasuredparameter toimplement theHRCPtripfunctionisappropriate, andtheRPSnuclearinstrumentation channelsdesignedtocoverthestartuprangesoftheSt.Luciereactorsarethewiderangelogarithmic neutronfluxmonitors.

Similartodesignfeaturesofthetrip,thepowerlevelatwhichthetripfunctionbypassmustberemovedduringareactorstartupisassociated withtheOPERATIONAL MODBofthereactorandmustbeinarangeofreactorpowerthatwillassuresuccessoftheprotective action.Theonsetofoperability fortheHRCPtripinMODE2duringstartupisatanexcoreneutronfluxthatcorresponds toapproximately 10percentoftheincorefull-power fissionrate.However,thethermalpowerproducedfromthisfissionrateistypically belowtheTHEMQPOWERdefinedbyTS1.33which,absentanexplicitmodifiertoindicateotherwise, includesdecayheat.IntheSt.Luciereactorsfollowing shutdownfromextendedpoweroperations tobelowMODE2,thethermalpowerproducedfromdecayheatistypically higherthanthethermalpowerproducedonlybythefi.ssionrate.Althoughtheexclusion ofdecayheatfromtheHRCptripisimpliedbythedefinition ofOPERATIONAL MODE,literalcompliance withtheTechnical Specification requirements fordefiningtheHRCPtripbypasssetpointasafunctionofTHERMALPOWERwasnotmet.AnalysisofSafetySignificance TheTechnical Specification inadequacy doesnotapplyduringshutdownreactoroperations orMODB1reactoroperation above15percentpower.Currently, bothSt.Lucieunitsareoperating inMIODE1above15percentpower,sonocurrentTechnical Specification compliance issueexists.Duringpastreactorstartups, literalcompliance withtheTechnical Specifications fortheHRCPtripwasnotmet.However,thedesignoftheHRCPtripfunctionanditsautomatic bypassremovalfeatureareassociated withthereactorpowergenerated onlybythefissionprocessandexcludesconsideration ofdecayheat.Decayheatisnotadirectlymeasureable parameter, doesnotreflectthereactivity condition ofthereactor,andisnotavariablenormallyassociated withtherateofchangeofreactorpower.Therefore, thehealthandsafetyofthepublicwerenotaffectedbythisevent.Corrective Actions1.St.Luciehasdeveloped andsubmitted anamendment tothelicensestoclarifythepowerrequirements forthe'HRCPtrip.TheTechni.cal Specification changeswillneedtobeapprovedbytheNRCpriortoanysubsequent unitstartup.2.FPLreviewedtheTechnical Specifications governing theautomatic removalof,andpermissives for,otherRPStripbypassesfortheincorrect useofTHERMALPOWERanddecayheat.Thelicenseamendments submitted inaction(1)abovealsoreplacesthetermTHERMALPOWERwiththepowermeasuredbytheappropriate neutronfluxmonitorforthetripbypassesassociated withtheRPSzeropowermodebypass,localpowerdensitytripbypass,andturbinetripbypass.Additional Information NoneNRCFORM3BBA18-1998)

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