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{{#Wiki_filter:ACCELERATEDDTRIBUTIONDEMONSTRATIONSYSTEMREGULATORYINFORMATIONDISTRXBUTIONSYSTEM(RIDS)ACCESSIONNBR:9101030143DOC.DATE:90/12/21NOTARIZED:NOFACIL:50-335St.LuciePlant,Unit1,FloridaPower&LightCo.50-389St.LuciePlant,Unit,2,FloridaPower&LightCo.AUTH.NAMEAUTHORAFFILIATIONSAGER,D.A.FloridaPower&LightCo.RECXP.NAMERECIPIENTAFFILIATXONDocumentControlBranch(DocumentControlDesk)DOCKET0500033505000389
{{#Wiki_filter:ACCELERATED DTRIBUTION DEMONSTRATION SYSTEMREGULATORY INFORMATION DISTRXBUTION SYSTEM(RIDS)ACCESSION NBR:9101030143 DOC.DATE:90/12/21NOTARIZED:
NOFACIL:50-335 St.LuciePlant,Unit1,FloridaPower&LightCo.50-389St.LuciePlant,Unit,2,FloridaPower&LightCo.AUTH.NAMEAUTHORAFFILIATION SAGER,D.A.
FloridaPower&LightCo.RECXP.NAME RECIPIENT AFFILIATXON DocumentControlBranch(Document ControlDesk)DOCKET0500033505000389


==SUBJECT:==
==SUBJECT:==
Submitscommentsondraftsafetyevaluationonstationblackoutrule(10CFR50.63),perNRC901121request.DISTRIBUTIONCODE:A050DCOPIESRECEIVED:LTRENCL0SIZE:(0TITLE:ORSubmittal:StationBlackout(USIA-4410CFR5.63,MPAA-22NOTES:RECIPIENTIDCODE/NAMEPD2-2PDXNTERNAL':ACRSNRR/DET/ESGB8DNRR/J39g+SPLB8D1~KEGFILE01EXTERNAL:NRCPDRCOPIESLTTRENCL1111223311RECIPIENT.XDCODE/NAMENORRIS,JNRRPD1-4PMTAMNRR/DST/SELBNRR/DST/SRXB8ENSICCOPIESLTTRENCL1111331111NOTETOALL"RIDS"RECIPIENTS:PLEASEHELPUSTOREDUCEiVASTE!CONTACTTHEDOCUMENTCONTROLDESK,ROOMP1-37(EXT.20079)TOELIMINATEYOURNAMEFROMDISTRIBUTIONLISTSFORDOCUMENTSYOUDON'TNEED!TOTALNUMBEROFCOPIESREQUIRED:LTTR16ENCL16 P.O.Box128,Ft.Pierce,FL34954-0128December21,1990L-90-45210CFR50.63U.S.NuclearRegulatoryCommissionAttn:DocumentControlDeskWashington,D.C.20555Gentlemen:Re:St.LucieUnits1and2DocketNos.50-335and50-389StationBlackoutRule-10CFR50.63ByletterdatedNovember21,1990(J.A.NorristoJ.H.Goldberg),theNRCforwardedtoFloridaPower&LightCompany(FPL),forcomment,adraftSafetyEvaluationontheStationBlackout(SBO)rule(10CFR50.63)forSt.LucieUnit1.FPLstronglydesirestoresolveSBOforSt.LucieUnits1and2inthesamemannernotwithstandingtheexemptionfromtherulerequirementsgrantedforSt.LucieUnit2.Inthislight,FPLprovidesthefollowingcomments.FPL'sapproachtotransientandemergencyeventsatitsnuclearpowerplantsensuresthecontinuedavailabilityofAlternatingCurrent(AC)electricalpower.Thisapproachhasbeenanintegralpartofournuclearplantoperatingstrategy.TheSBOrulepermitslicenseestoimplementthisstrategyinmeetingthecriteriaandrequirementsof10CFR50.63.FPLiscommittedtoresolveSBOforSt.LucieUnits1and2byuseofanalternateAC(AAC)source.FPLproposestomeettherequirementsoftheSBOrulebypreventingaunitblackoutorSBO;inthatrespect,theSt.LucieunitswillnotcopewitheithereventusingDirectCurrent(DC)power,but,ratherwillrecoverfromaLossofOffsitePower(LOOP)withtheassumedmultipleEDGfailuresbymeansofaunittounitACelectricalcrosstie.Thesafetyandnon-safetyrelatedequipmentFPLhasproposedtoloadonthesingleoperatingEmergencyDieselGenerator(EDG)isequipmentwhichisnecessarytoplacebothunitsinsafeshutdown(i.e.,hotstandby).FPL'scommentspresentedintheattachmenttothisletteraddressthefollowingaspectsoftheNRC'sdraftSafetyEvaluation:1)TheresolutionofSBOforSt.LucieUnits1and2usingtheAACsourceapproachincreasessafetymarginsfromthatofaDirectCurrent(DC)copingapproach.2)ElectricalloadingoftheoperatingEDGforthisevent(9i0103014390i22iPDRADOCK05000335PPDRA$~.nonFPLGroupcompany  
Submitscommentsondraftsafetyevaluation onstationblackoutrule(10CFR50.63),per NRC901121request.DISTRIBUTION CODE:A050DCOPIESRECEIVED:LTR ENCL0SIZE:(0TITLE:ORSubmittal:
''tg,44ll~l1 includestheACloadsnecessarytocopewithaLOOPandfailureofthreeEDGsforbothunits,excludingthefollowingloads,asallowedbycriteriaembodiedin10CFR50.63:a)ShutdownCooling(SDC)pumpsb)ACdrivenAuxiliaryFeedwater(AFW)pumps3)ReactorcoolantdepletionviasealleakageattherateassumedintheNRC'sSafetyEvaluationisnotaconsiderationforeitherunit.4)Managementofthesiteoperationsdictatesstandardizedprocedures,training,TechnicalSpecifications,andlicensinganddesignbasesforbothunitsonthesite.SincetheSt.LucieplantoperatorsarelicensedtooperatebothSt.Lucieunits,'ifferentlicensingbases,TechnicalSpecifications,andemergencyoperatingproceduresforrecoveringfromSBOoneitherunitwillpresentunnecessaryhumanfactorsconcerns.Attachedareourdetailedcommentsontheaboveissuesaswellasotheraspectsofthestaff'sdraftSafetyEvaluation.WeappreciatetheopportunitytoreviewandcommentonthisSafetyEvaluation.Verytrulyyours,D.A.aViceeridentSt.LuciePlantDAS/EJW/lefDAS/PSL75312cc:StewartD.Ebneter,RegionalAdministrator,USNRC,RegionIISeniorResidentInspector,USNRC,St.LuciePlant J~'It,1+%A,ph~Q~'
StationBlackout(USIA-4410CFR5.63,MPAA-22NOTES:RECIPIENT IDCODE/NAME PD2-2PDXNTERNAL':
ATTACHMENTFPLcommentsonNRCdraftSafetyEvaluationStationBlackoutRuleSt.LucieUnits1and2.FPLstronglydesirestoresolve10CFR50.63forbothSt.LucieUnits1and2inthesamemanner(i.e.,bymeansofanalternateAC(AAC)source).FPLhasidentifiedseverallicensinganddesignconcernswiththeresolutionof10CFR50.63inthestaff'sdraftSafetyEvaluation(SE),asdetailedbelow.IntroductionFPL'scompliancewith10CFR50.63,"Lossofallalternatingcurrentpower",andtheguidanceprovidedbyRegulatoryGuide1.155andNUMARC87-00areaimedatmeeting10~perreactoryearasanacceptablefrequencyforcoredamagecontributionfromsequencesinitiatedbyastationlossofoffsitepower(LOOP)'sestablishedbytheNRC.ResolutionofStationBlackout(SBO)forSt.LucieUnits1and2consistsofplantenhancementsandmodificationswhichwillresultinreducedfrequencyofcoredamagefromaunitorstationblackouteventtolessthan105perreactoryear.TheAdvisoryCommitteeonReactorSafeguards(ACRS),CommitteetoReviewGenericRequirements(CRGR)andNRCstaffrecognizedthatsomelicenseescouldprovide,ormayactuallyhaveinplace,additionaldiesels,gasturbinesorcross-connectoptionsattwo-unitsitesthatcouldserveasaone-of-fouremergencydieselgenerator(EDG)configurationratherthanone-of-twoEDGconfigurationsforunitblackoutconsiderations'.Thisrecognitionledtothe"10-minute"alternateAC(AAC)sourceatmulti-unitsites.Infact,thestatementsofconsiderationfortheruleidentifiedthisapproachasa"preferredoption"toresolve10CFR50.63.InlettersdatedApril17,1989andMarch7,1990(L-89-145andL-90-58,respectively),FPLproposedtoaddaremotemanualelectricalintertietocross-connectelectricalbusesbetweenSt.LucieUnits1and2suchthatthereliabilityoftheemergencyACpowersystemconfigurationafteraLOOPissignificantlyimproved.ThisconfigurationpermitsanyoneoffourEDGstomitigatetheeffectsofaunitblackoutatthe'NRCstaffresponsestoquestionsfromCommissionersAsselstine,Bernthal,RobertsandZechduringfinalrulemakingdecisionon"StationBlackout"regulationdateNovember10,1985.
ACRSNRR/DET/ESGB 8DNRR/J39g+SPLB8 D1~KEGFILE01EXTERNAL:
site.FPLhasshownthatoneEDGissufficienttoprovideallthenecessaryloadsassociatedwithplacingbothunitsinhotstandbyfrom1004powerfortherequiredblackoutduration.Additionally,FPLhasperformedapreliminaryriskassessmentwhichreflectsthesignificantriskreductiongainedbythemodificationsforapostulatedSBOevent.2)IncreasedSafetyMarginsforAACApproach.FPL'spreliminaryevaluationofriskreductionasaresultoftheAACapproachdemonstratesthatthecoremeltriskfromSBOafteraLOOPeventhasbeenreducedfromapproximately7.6x104to2.9x10~perreactoryear.Thisisdirectlyattributabletotheproposedunit-to-unitcross-tiecapabilityoftheelectricalsystemresultingintheaddedavailabilityoftwoEDGs.Theevaluationresultsinariskreductionfactorinexcessof200.Bycomparison,inNUREG-1032,"EvaluationofStationBlackoutAccidentsofNuclearPowerPlants"andinNUREG-1109,"RegulatoryAnalysisfortheResolutionofUnresolvedSafetyIssueA-44,StationBlackout",theNRCstaffreportsariskreductionfactorofapproximately2.5(i.e.2.1x10to0.8x10~perreactoryear)asthebasisforissuanceoftheSBOruleforunitswitha4hourDCcopingcapabilityandone-out-of-twoEDGconfiguration~.3)AlternateAC(AAC)LoadingFPLhasre-analyzedtheemergencydieselgenerator(EDG)loadingfortheproposedbusintertieforSt.LucieUnits1and2tomeetSBOcriteria.Thisre-analysisresultsinrevisedloadprofilesfromthoseprovidedtotheNRCstaffduringtheOctober1989SBOaudit.TheproposedelectricalloadingsfortheEDGstoaccommodatetheSBOeventareprovidedinattachedTable1forSt.LucieUnit1andTable2forSt.LucieUnit2.TheseloadingsareessentiallythemajorLOOPloadslistedintheUpdatedFinalSafetyAnalysisReport(UFSAR)withthefollowingexceptionstoaccountfortherequirementsof10CFR50.63:a)TheSBOandnon-blackedout(NBO)units'oadingsdonotincludethemotordrivenAuxiliaryFeedwater(AFW)pumps.TheNBOunitassumesfailureofaredundantEDG(i.e.,failureofthreeEDGsafterLOOPeventatthesite)toqualifythefourthEDGasanAACsource.AnassumedfailureoftheturbinedrivenAFWpumponeithertheSBORulemakingIssueAffirmation,SECY-88-22,January21,1988.  
NRCPDRCOPIESLTTRENCL1111223311RECIPIENT.
~~Pegg$vk,t orNBOunitforthiseventgoesbeyondtheassumptionsrequiredbytheregulations;FPLbelievesthatthisassumptionisnewcriterionwhichwasnotconsideredintheregulatoryanalysisfor10CFR50.63norisitincludedinRegulatoryGuide1.155.Theregulatoryanalysisfor10CFR50.63isbasedonasafetygoallimitingtheaveragecontributiontocoredamagefromaSBOtoabout10'erreactoryear.Asacomparison,theNRCstaff,inNUREG/CR-4710,"ShutdownDecayHeatRemovalAnalysisofa.CombustionEngineering2-LOOPPWR"hasanalyzedanumberoffailureprobabilitiesfortheSt.LuciePlant.TheNUREGreportsthatfailureofaturbinedrivenAFWpumpcoupledwithacommonmodefailureof2EDGsafteraLOOPeventresultsinafrequencyofoccurrenceof8.2x10~perreactoryear.ForthepostulatedSBOeventanadditionalEDGfailuremustbeassumed.Thisadditionalfailurewillfurtherreducethecoredamagecontributionbyafactorof5x10~.FPLbelievesthatthisisinconsistentwiththeanalysesusedtosupport10CFR50.63andistherefore,anewregulatorycriterionbeyond10CFR50.63.TheNRC-approvedguidelinesfrom"CombustionEngineeringEmergencyProceduresGuidelines"CEN-152,Rev.03,addressoperatoractionsforLOOPandSBOevents.TheseguidelinesandFPL'sproceduresgeneratedusingtheseguidelinescallforlimitingflowtoanyonesteamgeneratorduringtheseeventsto150gpmtominimizetheprobabilityofotherpostulatedover-coolingevents.TheturbinedrivenAFWpumphasgreatercapacitythanthemotordrivenpumpsandiscapableofsupplyingsufficientAFWflowtobothsteamgeneratorsfordecayheatremoval.FPL'semergencyoperatingprocedures,whichweredevelopedusingtheguidanceofCEN-152,requiretheoperatorstorestrictAFWflowbyplacingthemotordrivenpumpintherecirculationmodeforthepostulatedcasewhereaLOOPeventhasoccurredandthreeofthefourEDGsdonotstart.Procedureswillinstructtheoperatorto:i)verifyflowfromtheturbinedrivenAFWpump,ii)secureflowfromtheNBOunit'smotordrivenpump(inaccordancewithCEN-152guidance),andiii)proceedwiththe10-minutebusintertietopowertheblackedoutunit.SimilaractionswilltakeplaceontheSBOunit.Basedontheabove,theSBOloadevaluationdoesnotrequireincludingthemotordrivenAFWpump.  
XDCODE/NAME NORRIS,JNRRPD1-4PMTAMNRR/DST/SELB NRR/DST/SRXB8E NSICCOPIESLTTRENCL1111331111NOTETOALL"RIDS"RECIPIENTS:
*/Q'al b)Title10CFR50.63andNUMARC87-00definesafeshutdownashotstandbyorhotshutdown,asappropriate.ForEDGevaluationpurposes,FPLintendstomaintainbothunitsathotstandbyfortheeighthourLOOP/SBOduration.Forunitsinhotstandby,operatingpressuresandtemperaturesprohibittheuseandoperationoftheShutdownCooling(SDC)system(i.e.,theLowPressureSafetyInjectionpumpswhichareusedinnon-accidentconditionsforshutdowndecayheatremoval).PursuanttothedesignbasesoftheSt.LucieUnits1and2,theSDCsystemismanuallyplacedintoservicewhentheReactorCoolantSystem(RCS)pressureisapproximately275psig,andtemperatureislessthan325degreesF.TheSt.LucieUnits1and2SBOEDGloadingevaluationswillnotconsidermodechanges(i.e.,tocoldshutdown)duringtheeighthourAACcopingperiod;therefore,theSDCsystemwillnotbeusedduringthistime.Basedontheabove,FPLhasnotincludedtheSDCpumploadsintheEDGloadevaluationforSBO.4)ReactorCoolantInventorySt.LucieUnits1and2useAACforsafeshutdownduringthepostulatedSBOevent.FPLbelievesthegenericReactorCoolantPump(RCP)leakagecriterionof25gpmperpump(forplantswithDCcoping),wasintendedtoaddressunitsthatdonotprovidecoolingtotheRCPseals.AsAACplants,St.LucieUnits1and2willprovidecoolingwatertotheRCPsealsontheSBOunitshortlyafterenergizingtheintertie(i.e.,inapproximately10minutes).Asaresult,nosealdamageispostulatedandonlynormalsealleakoffneedbeassumedfortheRCPs.WithrespecttotheintegrityofSt.LucieUnit.1and2RCPsealsfollowingalossofcomponentcooling,itshouldbenotedthattheintegrityoftheRCPsealsofthetypeusedintheSt.LucieUnit1and2reactorcoolantpumpswasverifiedinaqualificationtestconductedatthepumpmanufacturer'stestfacility.Thisfull-scaletestsimulatedalltheconditionsoftemperature,pressureandfluidflowthatwouldbeexperiencedinaLOOPeventwhensealcoolingisinterruptedandthepump,shaftstopped.ItwasthegoalofthetesttoidentifytheeffectsoflossofcoolingtothesealsoverafourhourperiodwhichwouldrepresentanextendedlossofACpower.Afterfourhourswithoutanycoolingwaterflow,therewasnoobservedincreaseinsealleakagealthoughthesealtemperatureshadrisentoover400'Fwhilethesystempressurewasmaintainedat2500psi.Thetestwascontinuedforover50hoursandatnotimedidseal Y.1if%
PLEASEHELPUSTOREDUCEiVASTE!CONTACTTHEDOCUMENTCONTROLDESK,ROOMP1-37(EXT.20079)TOELIMINATE YOURNAMEFROMDISTRIBUTION LISTSFORDOCUMENTS YOUDON'TNEED!TOTALNUMBEROFCOPIESREQUIRED:
leakageexceed16.1gallonsperhour.ThistestdemonstratedthattheRCPsealswillmaintaintheirintegritythroughanextendedLOOPevent.ThistestwasperformedtoprovideinformationtoresolvetheSt.LucieUnit2lossofACpowerOperatingLicensingreviewandtheinformationisdirectlyapplicabletoSt.LucieUnit1whichutilizesidenticalRCPseals.ThetestreaffirmedthattheRCPsealsusedinSt.LucieUnit1and2willwithstandtheenvironmentassociatedwithasustainedlossofACpowerandwillnotdegradethereactorcoolantpressureboundary.5)OtherCommentsa)StationBlackoutDuration(Section2.1)Withrespecttothecopingassessment,St.LucieUnits1and2shouldbeevaluatedasAACplantswithpoweravailabletotheshutdownbuseswithin10minutesoftheonsetofanSBOevent.Therefore,acopingassessmentdoesnotneedtobeaddressed.b)AlternateACAACSource(Section2.2)ThestrategyforrecoveringfromanSBOeventonbothSt.Lucieunitswillinvolveelectricloadmanagement(i.e.,manualactionsoutsidetheControlRoom).Trainedoperatorsareanimportantandnecessarypartoftheplant's.responsetoanyLOOPandconcurrentunitblackoutrecoveryplan.FPLmaintainsthatoperatorscanandwillperformloadmanagementactionsrequiredtomaintainthenecessaryloadsforsafeshutdownwhileensuringtheEDGremainswithinitsloadrating.InaccordancewiththeSBOrule,atestwillbeperformedtoverifythattheAACpowersourcewillbeavailabletopowertheshutdownbuseswithin10minutesoftheonsetofSBO.c)ComressedAir(Section2.3.3)TheaircompressorshavethecapabilitytobemanuallyloadedontheEDGs.Theseaircompressorsareelectricallydriven,notdieseldriven.Inaddition,thecompressorswilloperateasrequired(notcontinuously)tomaintainpressure.Thisequipmentisnotrequiredtomaintainhotstandbybuthasbeenaddedasanoperatora3.d~
LTTR16ENCL16 P.O.Box128,Ft.Pierce,FL34954-0128 December21,1990L-90-45210CFR50.63U.S.NuclearRegulatory Commission Attn:DocumentControlDeskWashington, D.C.20555Gentlemen:
r'Jt d)EffectsofLossofVentilation(Section2.3.4)AllnecessaryventilationequipmentwillbepoweredbytheAACSourceduringanSBOevent.Therefore,additionalventilationstudiesarenotrequired.e)ScoeofStaffReview(Section2.8)AsdiscussedinthecommentsonSection2.3.4,"EffectsofLossofVentilation",itemf(heatingandventilationcalculations)shouldbedeleted.f)St.LucieUnit2SBOWithstandCaabilit(Section3.0)Asdiscussedabove,theEDGsofeitherUnit1orUnit2arecapableofsupplyingtheSBOloadsofbothunits.Therefore,theEDGsfrombothUnit1and2havethecapabilityandcapacitytobeAACpowersources.g)SummarandConclusions(Section4.0)Basedoncommentsfortheprecedingsections,thissectionshouldberevisedaccordingly.
Re:St.LucieUnits1and2DocketNos.50-335and50-389StationBlackoutRule-10CFR50.63ByletterdatedNovember21,1990(J.A.NorristoJ.H.Goldberg),
theNRCforwarded toFloridaPower&LightCompany(FPL),forcomment,adraftSafetyEvaluation ontheStationBlackout(SBO)rule(10CFR50.63)forSt.LucieUnit1.FPLstronglydesirestoresolveSBOforSt.LucieUnits1and2inthesamemannernotwithstanding theexemption fromtherulerequirements grantedforSt.LucieUnit2.Inthislight,FPLprovidesthefollowing comments.
FPL'sapproachtotransient andemergency eventsatitsnuclearpowerplantsensuresthecontinued availability ofAlternating Current(AC)electrical power.Thisapproachhasbeenanintegralpartofournuclearplantoperating strategy.
TheSBOrulepermitslicensees toimplement thisstrategyinmeetingthecriteriaandrequirements of10CFR50.63.FPLiscommitted toresolveSBOforSt.LucieUnits1and2byuseofanalternate AC(AAC)source.FPLproposestomeettherequirements oftheSBOrulebypreventing aunitblackoutorSBO;inthatrespect,theSt.LucieunitswillnotcopewitheithereventusingDirectCurrent(DC)power,but,ratherwillrecoverfromaLossofOffsitePower(LOOP)withtheassumedmultipleEDGfailuresbymeansofaunittounitACelectrical crosstie.
Thesafetyandnon-safety relatedequipment FPLhasproposedtoloadonthesingleoperating Emergency DieselGenerator (EDG)isequipment whichisnecessary toplacebothunitsinsafeshutdown(i.e.,hotstandby).
FPL'scommentspresented intheattachment tothisletteraddressthefollowing aspectsoftheNRC'sdraftSafetyEvaluation:
1)Theresolution ofSBOforSt.LucieUnits1and2usingtheAACsourceapproachincreases safetymarginsfromthatofaDirectCurrent(DC)copingapproach.
2)Electrical loadingoftheoperating EDGforthisevent(9i01030143 90i22iPDRADOCK05000335PPDRA$~.nonFPLGroupcompany  
''tg,44ll~l1 includestheACloadsnecessary tocopewithaLOOPandfailureofthreeEDGsforbothunits,excluding thefollowing loads,asallowedbycriteriaembodiedin10CFR50.63:a)ShutdownCooling(SDC)pumpsb)ACdrivenAuxiliary Feedwater (AFW)pumps3)Reactorcoolantdepletion viasealleakageattherateassumedintheNRC'sSafetyEvaluation isnotaconsideration foreitherunit.4)Management ofthesiteoperations dictatesstandardized procedures,
: training, Technical Specifications, andlicensing anddesignbasesforbothunitsonthesite.SincetheSt.Lucieplantoperators arelicensedtooperatebothSt.Lucieunits,'ifferent licensing bases,Technical Specifications, andemergency operating procedures forrecovering fromSBOoneitherunitwillpresentunnecessary humanfactorsconcerns.
Attachedareourdetailedcommentsontheaboveissuesaswellasotheraspectsofthestaff'sdraftSafetyEvaluation.
Weappreciate theopportunity toreviewandcommentonthisSafetyEvaluation.
Verytrulyyours,D.A.aViceeridentSt.LuciePlantDAS/EJW/lef DAS/PSL75312cc:StewartD.Ebneter,RegionalAdministrator, USNRC,RegionIISeniorResidentInspector, USNRC,St.LuciePlant J~'It,1+%A,ph~Q~'
ATTACHMENT FPLcommentsonNRCdraftSafetyEvaluation StationBlackoutRuleSt.LucieUnits1and2.FPLstronglydesirestoresolve10CFR50.63forbothSt.LucieUnits1and2inthesamemanner(i.e.,bymeansofanalternate AC(AAC)source).FPLhasidentified severallicensing anddesignconcernswiththeresolution of10CFR50.63inthestaff'sdraftSafetyEvaluation (SE),asdetailedbelow.Introduction FPL'scompliance with10CFR50.63,"Lossofallalternating currentpower",andtheguidanceprovidedbyRegulatory Guide1.155andNUMARC87-00areaimedatmeeting10~perreactoryearasanacceptable frequency forcoredamagecontribution fromsequences initiated byastationlossofoffsitepower(LOOP)'sestablished bytheNRC.Resolution ofStationBlackout(SBO)forSt.LucieUnits1and2consistsofplantenhancements andmodifications whichwillresultinreducedfrequency ofcoredamagefromaunitorstationblackouteventtolessthan105perreactoryear.TheAdvisoryCommittee onReactorSafeguards (ACRS),Committee toReviewGenericRequirements (CRGR)andNRCstaffrecognized thatsomelicensees couldprovide,ormayactuallyhaveinplace,additional diesels,gasturbinesorcross-connect optionsattwo-unitsitesthatcouldserveasaone-of-four emergency dieselgenerator (EDG)configuration ratherthanone-of-two EDGconfigurations forunitblackoutconsiderations'.
Thisrecognition ledtothe"10-minute" alternate AC(AAC)sourceatmulti-unit sites.Infact,thestatements ofconsideration fortheruleidentified thisapproachasa"preferred option"toresolve10CFR50.63.InlettersdatedApril17,1989andMarch7,1990(L-89-145 andL-90-58,respectively),
FPLproposedtoaddaremotemanualelectrical intertietocross-connect electrical busesbetweenSt.LucieUnits1and2suchthatthereliability oftheemergency ACpowersystemconfiguration afteraLOOPissignificantly improved.
Thisconfiguration permitsanyoneoffourEDGstomitigatetheeffectsofaunitblackoutatthe'NRCstaffresponses toquestions fromCommissioners Asselstine,
: Bernthal, RobertsandZechduringfinalrulemakingdecisionon"StationBlackout" regulation dateNovember10,1985.
site.FPLhasshownthatoneEDGissufficient toprovideallthenecessary loadsassociated withplacingbothunitsinhotstandbyfrom1004powerfortherequiredblackoutduration.
Additionally, FPLhasperformed apreliminary riskassessment whichreflectsthesignificant riskreduction gainedbythemodifications forapostulated SBOevent.2)Increased SafetyMarginsforAACApproach.
FPL'spreliminary evaluation ofriskreduction asaresultoftheAACapproachdemonstrates thatthecoremeltriskfromSBOafteraLOOPeventhasbeenreducedfromapproximately 7.6x104to2.9x10~perreactoryear.Thisisdirectlyattributable totheproposedunit-to-unit cross-tie capability oftheelectrical systemresulting intheaddedavailability oftwoEDGs.Theevaluation resultsinariskreduction factorinexcessof200.Bycomparison, inNUREG-1032, "Evaluation ofStationBlackoutAccidents ofNuclearPowerPlants"andinNUREG-1109, "Regulatory AnalysisfortheResolution ofUnresolved SafetyIssueA-44,StationBlackout",
theNRCstaffreportsariskreduction factorofapproximately 2.5(i.e.2.1x10to0.8x10~perreactoryear)asthebasisforissuanceoftheSBOruleforunitswitha4hourDCcopingcapability andone-out-of-two EDGconfiguration~.
3)Alternate AC(AAC)LoadingFPLhasre-analyzed theemergency dieselgenerator (EDG)loadingfortheproposedbusintertieforSt.LucieUnits1and2tomeetSBOcriteria.
Thisre-analysis resultsinrevisedloadprofilesfromthoseprovidedtotheNRCstaffduringtheOctober1989SBOaudit.Theproposedelectrical loadingsfortheEDGstoaccommodate theSBOeventareprovidedinattachedTable1forSt.LucieUnit1andTable2forSt.LucieUnit2.Theseloadingsareessentially themajorLOOPloadslistedintheUpdatedFinalSafetyAnalysisReport(UFSAR)withthefollowing exceptions toaccountfortherequirements of10CFR50.63:a)TheSBOandnon-blacked out(NBO)units'oadings donotincludethemotordrivenAuxiliary Feedwater (AFW)pumps.TheNBOunitassumesfailureofaredundant EDG(i.e.,failureofthreeEDGsafterLOOPeventatthesite)toqualifythefourthEDGasanAACsource.AnassumedfailureoftheturbinedrivenAFWpumponeithertheSBORulemaking IssueAffirmation, SECY-88-22, January21,1988.  
~~Pegg$vk,t orNBOunitforthiseventgoesbeyondtheassumptions requiredbytheregulations; FPLbelievesthatthisassumption isnewcriterion whichwasnotconsidered intheregulatory analysisfor10CFR50.63norisitincludedinRegulatory Guide1.155.Theregulatory analysisfor10CFR50.63isbasedonasafetygoallimitingtheaveragecontribution tocoredamagefromaSBOtoabout10'erreactoryear.Asacomparison, theNRCstaff,inNUREG/CR-4710, "Shutdown DecayHeatRemovalAnalysisofa.Combustion Engineering 2-LOOPPWR"hasanalyzedanumberoffailureprobabilities fortheSt.LuciePlant.TheNUREGreportsthatfailureofaturbinedrivenAFWpumpcoupledwithacommonmodefailureof2EDGsafteraLOOPeventresultsinafrequency ofoccurrence of8.2x10~perreactoryear.Forthepostulated SBOeventanadditional EDGfailuremustbeassumed.Thisadditional failurewillfurtherreducethecoredamagecontribution byafactorof5x10~.FPLbelievesthatthisisinconsistent withtheanalysesusedtosupport10CFR50.63andistherefore, anewregulatory criterion beyond10CFR50.63.TheNRC-approvedguidelines from"Combustion Engineering Emergency Procedures Guidelines" CEN-152,Rev.03,addressoperatoractionsforLOOPandSBOevents.Theseguidelines andFPL'sprocedures generated usingtheseguidelines callforlimitingflowtoanyonesteamgenerator duringtheseeventsto150gpmtominimizetheprobability ofotherpostulated over-cooling events.TheturbinedrivenAFWpumphasgreatercapacitythanthemotordrivenpumpsandiscapableofsupplying sufficient AFWflowtobothsteamgenerators fordecayheatremoval.FPL'semergency operating procedures, whichweredeveloped usingtheguidanceofCEN-152,requiretheoperators torestrictAFWflowbyplacingthemotordrivenpumpintherecirculation modeforthepostulated casewhereaLOOPeventhasoccurredandthreeofthefourEDGsdonotstart.Procedures willinstructtheoperatorto:i)verifyflowfromtheturbinedrivenAFWpump,ii)secureflowfromtheNBOunit'smotordrivenpump(inaccordance withCEN-152guidance),
andiii)proceedwiththe10-minute busintertietopowertheblackedoutunit.SimilaractionswilltakeplaceontheSBOunit.Basedontheabove,theSBOloadevaluation doesnotrequireincluding themotordrivenAFWpump.  
*/Q'al b)Title10CFR50.63andNUMARC87-00definesafeshutdownashotstandbyorhotshutdown, asappropriate.
ForEDGevaluation
: purposes, FPLintendstomaintainbothunitsathotstandbyfortheeighthourLOOP/SBOduration.
Forunitsinhotstandby,operating pressures andtemperatures prohibittheuseandoperation oftheShutdownCooling(SDC)system(i.e.,theLowPressureSafetyInjection pumpswhichareusedinnon-accident conditions forshutdowndecayheatremoval).
PursuanttothedesignbasesoftheSt.LucieUnits1and2,theSDCsystemismanuallyplacedintoservicewhentheReactorCoolantSystem(RCS)pressureisapproximately 275psig,andtemperature islessthan325degreesF.TheSt.LucieUnits1and2SBOEDGloadingevaluations willnotconsidermodechanges(i.e.,tocoldshutdown) duringtheeighthourAACcopingperiod;therefore, theSDCsystemwillnotbeusedduringthistime.Basedontheabove,FPLhasnotincludedtheSDCpumploadsintheEDGloadevaluation forSBO.4)ReactorCoolantInventory St.LucieUnits1and2useAACforsafeshutdownduringthepostulated SBOevent.FPLbelievesthegenericReactorCoolantPump(RCP)leakagecriterion of25gpmperpump(forplantswithDCcoping),wasintendedtoaddressunitsthatdonotprovidecoolingtotheRCPseals.AsAACplants,St.LucieUnits1and2willprovidecoolingwatertotheRCPsealsontheSBOunitshortlyafterenergizing theintertie(i.e.,inapproximately 10minutes).
Asaresult,nosealdamageispostulated andonlynormalsealleakoffneedbeassumedfortheRCPs.Withrespecttotheintegrity ofSt.LucieUnit.1and2RCPsealsfollowing alossofcomponent cooling,itshouldbenotedthattheintegrity oftheRCPsealsofthetypeusedintheSt.LucieUnit1and2reactorcoolantpumpswasverifiedinaqualification testconducted atthepumpmanufacturer's testfacility.
Thisfull-scale testsimulated alltheconditions oftemperature, pressureandfluidflowthatwouldbeexperienced inaLOOPeventwhensealcoolingisinterrupted andthepump,shaftstopped.Itwasthegoalofthetesttoidentifytheeffectsoflossofcoolingtothesealsoverafourhourperiodwhichwouldrepresent anextendedlossofACpower.Afterfourhourswithoutanycoolingwaterflow,therewasnoobservedincreaseinsealleakagealthoughthesealtemperatures hadrisentoover400'Fwhilethesystempressurewasmaintained at2500psi.Thetestwascontinued forover50hoursandatnotimedidseal Y.1if%
leakageexceed16.1gallonsperhour.Thistestdemonstrated thattheRCPsealswillmaintaintheirintegrity throughanextendedLOOPevent.Thistestwasperformed toprovideinformation toresolvetheSt.LucieUnit2lossofACpowerOperating Licensing reviewandtheinformation isdirectlyapplicable toSt.LucieUnit1whichutilizesidentical RCPseals.Thetestreaffirmed thattheRCPsealsusedinSt.LucieUnit1and2willwithstand theenvironment associated withasustained lossofACpowerandwillnotdegradethereactorcoolantpressureboundary.
5)OtherCommentsa)StationBlackoutDuration(Section2.1)Withrespecttothecopingassessment, St.LucieUnits1and2shouldbeevaluated asAACplantswithpoweravailable totheshutdownbuseswithin10minutesoftheonsetofanSBOevent.Therefore, acopingassessment doesnotneedtobeaddressed.
b)Alternate ACAACSource(Section2.2)Thestrategyforrecovering fromanSBOeventonbothSt.Lucieunitswillinvolveelectricloadmanagement (i.e.,manualactionsoutsidetheControlRoom).Trainedoperators areanimportant andnecessary partoftheplant's.response toanyLOOPandconcurrent unitblackoutrecoveryplan.FPLmaintains thatoperators canandwillperformloadmanagement actionsrequiredtomaintainthenecessary loadsforsafeshutdownwhileensuringtheEDGremainswithinitsloadrating.Inaccordance withtheSBOrule,atestwillbeperformed toverifythattheAACpowersourcewillbeavailable topowertheshutdownbuseswithin10minutesoftheonsetofSBO.c)ComressedAir(Section2.3.3)Theaircompressors havethecapability tobemanuallyloadedontheEDGs.Theseaircompressors areelectrically driven,notdieseldriven.Inaddition, thecompressors willoperateasrequired(notcontinuously) tomaintainpressure.
Thisequipment isnotrequiredtomaintainhotstandbybuthasbeenaddedasanoperatora3.d~
r'Jt d)EffectsofLossofVentilation (Section2.3.4)Allnecessary ventilation equipment willbepoweredbytheAACSourceduringanSBOevent.Therefore, additional ventilation studiesarenotrequired.
e)ScoeofStaffReview(Section2.8)Asdiscussed inthecommentsonSection2.3.4,"EffectsofLossofVentilation",
itemf(heatingandventilation calculations) shouldbedeleted.f)St.LucieUnit2SBOWithstand Caabilit(Section3.0)Asdiscussed above,theEDGsofeitherUnit1orUnit2arecapableofsupplying theSBOloadsofbothunits.Therefore, theEDGsfrombothUnit1and2havethecapability andcapacitytobeAACpowersources.g)SummarandConclusions (Section4.0)Basedoncommentsforthepreceding
: sections, thissectionshouldberevisedaccordingly.
44'  
44'  
~~4FloridaPowerandLightTable1St.LucieUnit1ElectricalLoadingsUNIT1DESIGNATIONSPDHDSH~FLAHP/KVAKWEMERGENCYLIGHTINGCLASS1EPOWERPANELSCONTAINHENTFAHCOOLERS(2)COHPOHENTCOOLIHGWATERPUHPSINTAKECOOLINGWATERPUHPSICWBUILDINGCOOLINGFANSCONTROLROOMA/CAUXILIARYBUILDINGSUPPLYFANSECCSAREAEXHAUSTFANSREACTORCAVITYCOOLINGFANSREACTORSUPPORTCOOLINGFANSEEROOMSUPPLYFANSEEROOMEXHAUSTFANSEEROOMROOFVENTSBATTERYROOHEXHAUSTFANSBATTERYCHARGERSUPSINVERTERSPLANTSECURITYINVERTERSPRESSURIZERHTRS.BACKUPBANKINST'IR(IA)COMPRESSORSCOOLINGFORIACOMPRESSORSEDGFUELTRANSFERPUMPSCHARGINGPUHPSMISC.LP'SMISC.PP'S1HVS1A&BORC&01A,18,1C1A,18,1CACC&HVA3A,B,C1HVS4A,481HVE9A,981HVS2A,281HVE3A,381HVS5A,581HVE11,121RV3,1RV41RV1,1RV21A,18INV.UPS.REC.PL.SEC.INV.*82OR85*1A,18AIRCOMPMOTOR*1A,18*1A,18,1C164,54,535,36,4134,3936,4231,3831,3933,3935,4132,415C,5332,394444A1935,43A626216203608154.4/10.67259,49264938102.54.29047.248.6387.5049112111815045060040/7.56050,40204022.17.51.5.2568KVA20KVA20KVA186407.55100125.75149.08123.00369.00451.0042.7044'037.8315.4621.5713.484.391.400.2268.0020.0020F00186.0036.006.704.5082F0086.85109.14123.00369.00451~0042.7044.2032.2015.4621.5713.484.391.400.2268.0020.0020.00186.0036.006.704.5082.00*USEDINTERHITTENTLY-ONLYPRESSURIZERHEATERSINCLUDEDINTOTAL1693.081608.61UNIT1EDGRATINGSREF.FLO8770-305CONTINUOUSDUTY-"3500KW2000HRSRATING=3730KW7DAYRATING=3790KW4HRSRATING=3860KW30HINRATING-"3960KWU1MAXIMUMVALUE=1693.08KWU2MAXIHUHVALUE=1800.11KWCOMBINEDTOTAL=3C93.19KWCOMBINEDTOTAL=100KOFUNIT1,CONT.RATING SWI  
~~4FloridaPowerandLightTable1St.LucieUnit1Electrical LoadingsUNIT1DESIGNATIONS PDHDSH~FLAHP/KVAKWEMERGENCY LIGHTINGCLASS1EPOWERPANELSCONTAINHENT FAHCOOLERS(2)COHPOHENT COOLIHGWATERPUHPSINTAKECOOLINGWATERPUHPSICWBUILDINGCOOLINGFANSCONTROLROOMA/CAUXILIARY BUILDINGSUPPLYFANSECCSAREAEXHAUSTFANSREACTORCAVITYCOOLINGFANSREACTORSUPPORTCOOLINGFANSEEROOMSUPPLYFANSEEROOMEXHAUSTFANSEEROOMROOFVENTSBATTERYROOHEXHAUSTFANSBATTERYCHARGERSUPSINVERTERS PLANTSECURITYINVERTERS PRESSURIZER HTRS.BACKUPBANKINST'IR(IA)COMPRESSORS COOLINGFORIACOMPRESSORS EDGFUELTRANSFERPUMPSCHARGINGPUHPSMISC.LP'SMISC.PP'S1HVS1A&BORC&01A,18,1C1A,18,1CACC&HVA3A,B,C1HVS4A,481HVE9A,981HVS2A,281HVE3A,381HVS5A,581HVE11,121RV3,1RV4 1RV1,1RV2 1A,18INV.UPS.REC.PL.SEC.INV.*82OR85*1A,18AIRCOMPMOTOR*1A,18*1A,18,1C164,54,535,36,4134,3936,4231,3831,3933,3935,4132,415C,5332,394444A1935,43A626216203608154.4/10.6 7259,49264938102.54.29047.248.6387.5049112111815045060040/7.56050,40204022.17.51.5.2568KVA20KVA20KVA186407.55100125.75149.08123.00369.00451.0042.7044'037.8315.4621.5713.484.391.400.2268.0020.0020F00186.0036.006.704.5082F0086.85109.14123.00369.00451~0042.7044.2032.2015.4621.5713.484.391.400.2268.0020.0020.00186.0036.006.704.5082.00*USEDINTERHITTENTLY
-FloridaPowerandLightTable2St.LucieUnit2ElectricalLoadingsUNIT2DESIGNATIONSPDMDSH.FLAHP/KVAKWEMERGENCYLIGHTINGCLASS1EPOWERPAHELSCONTAINMENTFANCOOLERS(2)COMPONENTCOOLINGWATERPUMPSINTAKECOOLINGWATERPUMPSICWBUILDINGCOOLINGFANSCONTROLROOMA/CAUXILIARYBUILDINGSUPPLYFANSECCSAREAEXHAUSTFANSREACTORCAVITYCOOLINGFANSREACTORSUPPORTCOOLINGFANSEEROOMSUPPLYFANSEEROOMEXHAUSTFANSEEROOMROOFVENTSBATTERYROOMEXHAUSTFANSBATTERYCHARGERSUPSINVERTERSPLANTSECURITYINVERTERSPRESSURIZERHTRS~PROPSBANKSINST.AIR(IA)COMPRESSORSCOOLINGFORIACOMPRESSORSEDGFUELTRANSFERPUMPSCHARGINGPUMPSMISC.LP'SMISC.PP'S2HVS1A&BORC&D2A,2B,2C2A,28,2C2HVE41A,B2HVA/ACC-3A,B,C2HVS-4A,4B2HVE9A,982HVS2A,2B2HVE'3A,3B2HVS5A,5B2HVE11,122RV3,2RV42RV1,2RV22A,28INV.UPS.REC.VITALA/CCAB.*P1ORP2*2A,28"AIRCOMPMOTOR*2A,2B*2A,28,2C1024,54,534,3936,4211131,423736,3933,3935,4132,4137A,43832,394444A1935,436262161446082.49.468.1,4916573,652447115596.591.429018,4060312.5751141451254506007.555,4015060'20401005050.7568KVA20KVA30KVA150KW607.5312584.9265.84141.00369.00492.006.7049.40112.9750.8113.6621.7777.1741.744.460.6768.0020F0030.00150.0054.006.802.70102.4769.4354.87141.00369.00492.006.7049.40112.9752.9413.6621.7777.1741.744.460.6768.0020.0030F00150.0054.006.802.70102.47*USEDINTERMITTENTLY-ONLYPRESSURIZERHEATERSINCLUDEDIHTOTAL1800.111775.78UNIT2EDGRATINGSREF.FLO2998-305CONTINUOUSDUl'Y=3685KW2000HRSRATING"-3935KW7DAYRATING=3985KW4HRSRATING<3985KW30MIHRATING-"3985KWU1MAXIMUMVALUE~1693~08KWU2MAXIMUMVALUE=1800~11KWCOMBINEDTOTAL<3493.19KWCOMBINEDTOTAL>95XOFUNIT2,CONT.RATING}}
-ONLYPRESSURIZER HEATERSINCLUDEDINTOTAL1693.081608.61UNIT1EDGRATINGSREF.FLO8770-305CONTINUOUS DUTY-"3500KW2000HRSRATING=3730KW7DAYRATING=3790KW4HRSRATING=3860KW30HINRATING-"3960KWU1MAXIMUMVALUE=1693.08KWU2MAXIHUHVALUE=1800.11KWCOMBINEDTOTAL=3C93.19KWCOMBINEDTOTAL=100KOFUNIT1,CONT.RATING SWI  
-FloridaPowerandLightTable2St.LucieUnit2Electrical LoadingsUNIT2DESIGNATIONSPDMDSH.FLAHP/KVAKWEMERGENCY LIGHTINGCLASS1EPOWERPAHELSCONTAINMENT FANCOOLERS(2)COMPONENT COOLINGWATERPUMPSINTAKECOOLINGWATERPUMPSICWBUILDINGCOOLINGFANSCONTROLROOMA/CAUXILIARY BUILDINGSUPPLYFANSECCSAREAEXHAUSTFANSREACTORCAVITYCOOLINGFANSREACTORSUPPORTCOOLINGFANSEEROOMSUPPLYFANSEEROOMEXHAUSTFANSEEROOMROOFVENTSBATTERYROOMEXHAUSTFANSBATTERYCHARGERSUPSINVERTERS PLANTSECURITYINVERTERS PRESSURIZER HTRS~PROPSBANKSINST.AIR(IA)COMPRESSORS COOLINGFORIACOMPRESSORS EDGFUELTRANSFERPUMPSCHARGINGPUMPSMISC.LP'SMISC.PP'S2HVS1A&BORC&D2A,2B,2C2A,28,2C2HVE41A,B2HVA/ACC-3A,B,C 2HVS-4A,4B 2HVE9A,982HVS2A,2B2HVE'3A,3B 2HVS5A,5B2HVE11,122RV3,2RV4 2RV1,2RV2 2A,28INV.UPS.REC.VITALA/CCAB.*P1ORP2*2A,28"AIRCOMPMOTOR*2A,2B*2A,28,2C1024,54,534,3936,4211131,423736,3933,3935,4132,4137A,43832,394444A1935,436262161446082.49.468.1,4916573,652447115596.591.429018,4060312.5751141451254506007.555,4015060'20401005050.7568KVA20KVA30KVA150KW607.5312584.9265.84141.00369.00492.006.7049.40112.9750.8113.6621.7777.1741.744.460.6768.0020F0030.00150.0054.006.802.70102.4769.4354.87141.00369.00492.006.7049.40112.9752.9413.6621.7777.1741.744.460.6768.0020.0030F00150.0054.006.802.70102.47*USEDINTERMITTENTLY
-ONLYPRESSURIZER HEATERSINCLUDEDIHTOTAL1800.111775.78UNIT2EDGRATINGSREF.FLO2998-305CONTINUOUS DUl'Y=3685KW2000HRSRATING"-3935KW7DAYRATING=3985KW4HRSRATING<3985KW30MIHRATING-"3985KWU1MAXIMUMVALUE~1693~08KWU2MAXIMUMVALUE=1800~11KWCOMBINEDTOTAL<3493.19KWCOMBINEDTOTAL>95XOFUNIT2,CONT.RATING}}

Revision as of 16:28, 29 June 2018

Submits Comments on Draft Safety Evaluation on Station Blackout Rule (10CFR50.63),per NRC 901121 Request
ML17223B040
Person / Time
Site: Saint Lucie  NextEra Energy icon.png
Issue date: 12/21/1990
From: SAGER D A
FLORIDA POWER & LIGHT CO.
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
L-90-452, NUDOCS 9101030143
Download: ML17223B040 (19)
v • d • e


Text

ACCELERATED DTRIBUTION DEMONSTRATION SYSTEMREGULATORY INFORMATION DISTRXBUTION SYSTEM(RIDS)ACCESSION NBR:9101030143 DOC.DATE:90/12/21NOTARIZED:

NOFACIL:50-335 St.LuciePlant,Unit1,FloridaPower&LightCo.50-389St.LuciePlant,Unit,2,FloridaPower&LightCo.AUTH.NAMEAUTHORAFFILIATION SAGER,D.A.

FloridaPower&LightCo.RECXP.NAME RECIPIENT AFFILIATXON DocumentControlBranch(Document ControlDesk)DOCKET0500033505000389

SUBJECT:

Submitscommentsondraftsafetyevaluation onstationblackoutrule(10CFR50.63),per NRC901121request.DISTRIBUTION CODE:A050DCOPIESRECEIVED:LTR ENCL0SIZE:(0TITLE:ORSubmittal:

StationBlackout(USIA-4410CFR5.63,MPAA-22NOTES:RECIPIENT IDCODE/NAME PD2-2PDXNTERNAL':

ACRSNRR/DET/ESGB 8DNRR/J39g+SPLB8 D1~KEGFILE01EXTERNAL:

NRCPDRCOPIESLTTRENCL1111223311RECIPIENT.

XDCODE/NAME NORRIS,JNRRPD1-4PMTAMNRR/DST/SELB NRR/DST/SRXB8E NSICCOPIESLTTRENCL1111331111NOTETOALL"RIDS"RECIPIENTS:

PLEASEHELPUSTOREDUCEiVASTE!CONTACTTHEDOCUMENTCONTROLDESK,ROOMP1-37(EXT.20079)TOELIMINATE YOURNAMEFROMDISTRIBUTION LISTSFORDOCUMENTS YOUDON'TNEED!TOTALNUMBEROFCOPIESREQUIRED:

LTTR16ENCL16 P.O.Box128,Ft.Pierce,FL34954-0128 December21,1990L-90-45210CFR50.63U.S.NuclearRegulatory Commission Attn:DocumentControlDeskWashington, D.C.20555Gentlemen:

Re:St.LucieUnits1and2DocketNos.50-335and50-389StationBlackoutRule-10CFR50.63ByletterdatedNovember21,1990(J.A.NorristoJ.H.Goldberg),

theNRCforwarded toFloridaPower&LightCompany(FPL),forcomment,adraftSafetyEvaluation ontheStationBlackout(SBO)rule(10CFR50.63)forSt.LucieUnit1.FPLstronglydesirestoresolveSBOforSt.LucieUnits1and2inthesamemannernotwithstanding theexemption fromtherulerequirements grantedforSt.LucieUnit2.Inthislight,FPLprovidesthefollowing comments.

FPL'sapproachtotransient andemergency eventsatitsnuclearpowerplantsensuresthecontinued availability ofAlternating Current(AC)electrical power.Thisapproachhasbeenanintegralpartofournuclearplantoperating strategy.

TheSBOrulepermitslicensees toimplement thisstrategyinmeetingthecriteriaandrequirements of10CFR50.63.FPLiscommitted toresolveSBOforSt.LucieUnits1and2byuseofanalternate AC(AAC)source.FPLproposestomeettherequirements oftheSBOrulebypreventing aunitblackoutorSBO;inthatrespect,theSt.LucieunitswillnotcopewitheithereventusingDirectCurrent(DC)power,but,ratherwillrecoverfromaLossofOffsitePower(LOOP)withtheassumedmultipleEDGfailuresbymeansofaunittounitACelectrical crosstie.

Thesafetyandnon-safety relatedequipment FPLhasproposedtoloadonthesingleoperating Emergency DieselGenerator (EDG)isequipment whichisnecessary toplacebothunitsinsafeshutdown(i.e.,hotstandby).

FPL'scommentspresented intheattachment tothisletteraddressthefollowing aspectsoftheNRC'sdraftSafetyEvaluation:

1)Theresolution ofSBOforSt.LucieUnits1and2usingtheAACsourceapproachincreases safetymarginsfromthatofaDirectCurrent(DC)copingapproach.

2)Electrical loadingoftheoperating EDGforthisevent(9i01030143 90i22iPDRADOCK05000335PPDRA$~.nonFPLGroupcompany

tg,44ll~l1 includestheACloadsnecessary tocopewithaLOOPandfailureofthreeEDGsforbothunits,excluding thefollowing loads,asallowedbycriteriaembodiedin10CFR50.63:a)ShutdownCooling(SDC)pumpsb)ACdrivenAuxiliary Feedwater (AFW)pumps3)Reactorcoolantdepletion viasealleakageattherateassumedintheNRC'sSafetyEvaluation isnotaconsideration foreitherunit.4)Management ofthesiteoperations dictatesstandardized procedures,

training, Technical Specifications, andlicensing anddesignbasesforbothunitsonthesite.SincetheSt.Lucieplantoperators arelicensedtooperatebothSt.Lucieunits,'ifferent licensing bases,Technical Specifications, andemergency operating procedures forrecovering fromSBOoneitherunitwillpresentunnecessary humanfactorsconcerns.

Attachedareourdetailedcommentsontheaboveissuesaswellasotheraspectsofthestaff'sdraftSafetyEvaluation.

Weappreciate theopportunity toreviewandcommentonthisSafetyEvaluation.

Verytrulyyours,D.A.aViceeridentSt.LuciePlantDAS/EJW/lef DAS/PSL75312cc:StewartD.Ebneter,RegionalAdministrator, USNRC,RegionIISeniorResidentInspector, USNRC,St.LuciePlant J~'It,1+%A,ph~Q~'

ATTACHMENT FPLcommentsonNRCdraftSafetyEvaluation StationBlackoutRuleSt.LucieUnits1and2.FPLstronglydesirestoresolve10CFR50.63forbothSt.LucieUnits1and2inthesamemanner(i.e.,bymeansofanalternate AC(AAC)source).FPLhasidentified severallicensing anddesignconcernswiththeresolution of10CFR50.63inthestaff'sdraftSafetyEvaluation (SE),asdetailedbelow.Introduction FPL'scompliance with10CFR50.63,"Lossofallalternating currentpower",andtheguidanceprovidedbyRegulatory Guide1.155andNUMARC87-00areaimedatmeeting10~perreactoryearasanacceptable frequency forcoredamagecontribution fromsequences initiated byastationlossofoffsitepower(LOOP)'sestablished bytheNRC.Resolution ofStationBlackout(SBO)forSt.LucieUnits1and2consistsofplantenhancements andmodifications whichwillresultinreducedfrequency ofcoredamagefromaunitorstationblackouteventtolessthan105perreactoryear.TheAdvisoryCommittee onReactorSafeguards (ACRS),Committee toReviewGenericRequirements (CRGR)andNRCstaffrecognized thatsomelicensees couldprovide,ormayactuallyhaveinplace,additional diesels,gasturbinesorcross-connect optionsattwo-unitsitesthatcouldserveasaone-of-four emergency dieselgenerator (EDG)configuration ratherthanone-of-two EDGconfigurations forunitblackoutconsiderations'.

Thisrecognition ledtothe"10-minute" alternate AC(AAC)sourceatmulti-unit sites.Infact,thestatements ofconsideration fortheruleidentified thisapproachasa"preferred option"toresolve10CFR50.63.InlettersdatedApril17,1989andMarch7,1990(L-89-145 andL-90-58,respectively),

FPLproposedtoaddaremotemanualelectrical intertietocross-connect electrical busesbetweenSt.LucieUnits1and2suchthatthereliability oftheemergency ACpowersystemconfiguration afteraLOOPissignificantly improved.

Thisconfiguration permitsanyoneoffourEDGstomitigatetheeffectsofaunitblackoutatthe'NRCstaffresponses toquestions fromCommissioners Asselstine,

Bernthal, RobertsandZechduringfinalrulemakingdecisionon"StationBlackout" regulation dateNovember10,1985.

site.FPLhasshownthatoneEDGissufficient toprovideallthenecessary loadsassociated withplacingbothunitsinhotstandbyfrom1004powerfortherequiredblackoutduration.

Additionally, FPLhasperformed apreliminary riskassessment whichreflectsthesignificant riskreduction gainedbythemodifications forapostulated SBOevent.2)Increased SafetyMarginsforAACApproach.

FPL'spreliminary evaluation ofriskreduction asaresultoftheAACapproachdemonstrates thatthecoremeltriskfromSBOafteraLOOPeventhasbeenreducedfromapproximately 7.6x104to2.9x10~perreactoryear.Thisisdirectlyattributable totheproposedunit-to-unit cross-tie capability oftheelectrical systemresulting intheaddedavailability oftwoEDGs.Theevaluation resultsinariskreduction factorinexcessof200.Bycomparison, inNUREG-1032, "Evaluation ofStationBlackoutAccidents ofNuclearPowerPlants"andinNUREG-1109, "Regulatory AnalysisfortheResolution ofUnresolved SafetyIssueA-44,StationBlackout",

theNRCstaffreportsariskreduction factorofapproximately 2.5(i.e.2.1x10to0.8x10~perreactoryear)asthebasisforissuanceoftheSBOruleforunitswitha4hourDCcopingcapability andone-out-of-two EDGconfiguration~.

3)Alternate AC(AAC)LoadingFPLhasre-analyzed theemergency dieselgenerator (EDG)loadingfortheproposedbusintertieforSt.LucieUnits1and2tomeetSBOcriteria.

Thisre-analysis resultsinrevisedloadprofilesfromthoseprovidedtotheNRCstaffduringtheOctober1989SBOaudit.Theproposedelectrical loadingsfortheEDGstoaccommodate theSBOeventareprovidedinattachedTable1forSt.LucieUnit1andTable2forSt.LucieUnit2.Theseloadingsareessentially themajorLOOPloadslistedintheUpdatedFinalSafetyAnalysisReport(UFSAR)withthefollowing exceptions toaccountfortherequirements of10CFR50.63:a)TheSBOandnon-blacked out(NBO)units'oadings donotincludethemotordrivenAuxiliary Feedwater (AFW)pumps.TheNBOunitassumesfailureofaredundant EDG(i.e.,failureofthreeEDGsafterLOOPeventatthesite)toqualifythefourthEDGasanAACsource.AnassumedfailureoftheturbinedrivenAFWpumponeithertheSBORulemaking IssueAffirmation, SECY-88-22, January21,1988.

~~Pegg$vk,t orNBOunitforthiseventgoesbeyondtheassumptions requiredbytheregulations; FPLbelievesthatthisassumption isnewcriterion whichwasnotconsidered intheregulatory analysisfor10CFR50.63norisitincludedinRegulatory Guide1.155.Theregulatory analysisfor10CFR50.63isbasedonasafetygoallimitingtheaveragecontribution tocoredamagefromaSBOtoabout10'erreactoryear.Asacomparison, theNRCstaff,inNUREG/CR-4710, "Shutdown DecayHeatRemovalAnalysisofa.Combustion Engineering 2-LOOPPWR"hasanalyzedanumberoffailureprobabilities fortheSt.LuciePlant.TheNUREGreportsthatfailureofaturbinedrivenAFWpumpcoupledwithacommonmodefailureof2EDGsafteraLOOPeventresultsinafrequency ofoccurrence of8.2x10~perreactoryear.Forthepostulated SBOeventanadditional EDGfailuremustbeassumed.Thisadditional failurewillfurtherreducethecoredamagecontribution byafactorof5x10~.FPLbelievesthatthisisinconsistent withtheanalysesusedtosupport10CFR50.63andistherefore, anewregulatory criterion beyond10CFR50.63.TheNRC-approvedguidelines from"Combustion Engineering Emergency Procedures Guidelines" CEN-152,Rev.03,addressoperatoractionsforLOOPandSBOevents.Theseguidelines andFPL'sprocedures generated usingtheseguidelines callforlimitingflowtoanyonesteamgenerator duringtheseeventsto150gpmtominimizetheprobability ofotherpostulated over-cooling events.TheturbinedrivenAFWpumphasgreatercapacitythanthemotordrivenpumpsandiscapableofsupplying sufficient AFWflowtobothsteamgenerators fordecayheatremoval.FPL'semergency operating procedures, whichweredeveloped usingtheguidanceofCEN-152,requiretheoperators torestrictAFWflowbyplacingthemotordrivenpumpintherecirculation modeforthepostulated casewhereaLOOPeventhasoccurredandthreeofthefourEDGsdonotstart.Procedures willinstructtheoperatorto:i)verifyflowfromtheturbinedrivenAFWpump,ii)secureflowfromtheNBOunit'smotordrivenpump(inaccordance withCEN-152guidance),

andiii)proceedwiththe10-minute busintertietopowertheblackedoutunit.SimilaractionswilltakeplaceontheSBOunit.Basedontheabove,theSBOloadevaluation doesnotrequireincluding themotordrivenAFWpump.

  • /Q'al b)Title10CFR50.63andNUMARC87-00definesafeshutdownashotstandbyorhotshutdown, asappropriate.

ForEDGevaluation

purposes, FPLintendstomaintainbothunitsathotstandbyfortheeighthourLOOP/SBOduration.

Forunitsinhotstandby,operating pressures andtemperatures prohibittheuseandoperation oftheShutdownCooling(SDC)system(i.e.,theLowPressureSafetyInjection pumpswhichareusedinnon-accident conditions forshutdowndecayheatremoval).

PursuanttothedesignbasesoftheSt.LucieUnits1and2,theSDCsystemismanuallyplacedintoservicewhentheReactorCoolantSystem(RCS)pressureisapproximately 275psig,andtemperature islessthan325degreesF.TheSt.LucieUnits1and2SBOEDGloadingevaluations willnotconsidermodechanges(i.e.,tocoldshutdown) duringtheeighthourAACcopingperiod;therefore, theSDCsystemwillnotbeusedduringthistime.Basedontheabove,FPLhasnotincludedtheSDCpumploadsintheEDGloadevaluation forSBO.4)ReactorCoolantInventory St.LucieUnits1and2useAACforsafeshutdownduringthepostulated SBOevent.FPLbelievesthegenericReactorCoolantPump(RCP)leakagecriterion of25gpmperpump(forplantswithDCcoping),wasintendedtoaddressunitsthatdonotprovidecoolingtotheRCPseals.AsAACplants,St.LucieUnits1and2willprovidecoolingwatertotheRCPsealsontheSBOunitshortlyafterenergizing theintertie(i.e.,inapproximately 10minutes).

Asaresult,nosealdamageispostulated andonlynormalsealleakoffneedbeassumedfortheRCPs.Withrespecttotheintegrity ofSt.LucieUnit.1and2RCPsealsfollowing alossofcomponent cooling,itshouldbenotedthattheintegrity oftheRCPsealsofthetypeusedintheSt.LucieUnit1and2reactorcoolantpumpswasverifiedinaqualification testconducted atthepumpmanufacturer's testfacility.

Thisfull-scale testsimulated alltheconditions oftemperature, pressureandfluidflowthatwouldbeexperienced inaLOOPeventwhensealcoolingisinterrupted andthepump,shaftstopped.Itwasthegoalofthetesttoidentifytheeffectsoflossofcoolingtothesealsoverafourhourperiodwhichwouldrepresent anextendedlossofACpower.Afterfourhourswithoutanycoolingwaterflow,therewasnoobservedincreaseinsealleakagealthoughthesealtemperatures hadrisentoover400'Fwhilethesystempressurewasmaintained at2500psi.Thetestwascontinued forover50hoursandatnotimedidseal Y.1if%

leakageexceed16.1gallonsperhour.Thistestdemonstrated thattheRCPsealswillmaintaintheirintegrity throughanextendedLOOPevent.Thistestwasperformed toprovideinformation toresolvetheSt.LucieUnit2lossofACpowerOperating Licensing reviewandtheinformation isdirectlyapplicable toSt.LucieUnit1whichutilizesidentical RCPseals.Thetestreaffirmed thattheRCPsealsusedinSt.LucieUnit1and2willwithstand theenvironment associated withasustained lossofACpowerandwillnotdegradethereactorcoolantpressureboundary.

5)OtherCommentsa)StationBlackoutDuration(Section2.1)Withrespecttothecopingassessment, St.LucieUnits1and2shouldbeevaluated asAACplantswithpoweravailable totheshutdownbuseswithin10minutesoftheonsetofanSBOevent.Therefore, acopingassessment doesnotneedtobeaddressed.

b)Alternate ACAACSource(Section2.2)Thestrategyforrecovering fromanSBOeventonbothSt.Lucieunitswillinvolveelectricloadmanagement (i.e.,manualactionsoutsidetheControlRoom).Trainedoperators areanimportant andnecessary partoftheplant's.response toanyLOOPandconcurrent unitblackoutrecoveryplan.FPLmaintains thatoperators canandwillperformloadmanagement actionsrequiredtomaintainthenecessary loadsforsafeshutdownwhileensuringtheEDGremainswithinitsloadrating.Inaccordance withtheSBOrule,atestwillbeperformed toverifythattheAACpowersourcewillbeavailable topowertheshutdownbuseswithin10minutesoftheonsetofSBO.c)ComressedAir(Section2.3.3)Theaircompressors havethecapability tobemanuallyloadedontheEDGs.Theseaircompressors areelectrically driven,notdieseldriven.Inaddition, thecompressors willoperateasrequired(notcontinuously) tomaintainpressure.

Thisequipment isnotrequiredtomaintainhotstandbybuthasbeenaddedasanoperatora3.d~

r'Jt d)EffectsofLossofVentilation (Section2.3.4)Allnecessary ventilation equipment willbepoweredbytheAACSourceduringanSBOevent.Therefore, additional ventilation studiesarenotrequired.

e)ScoeofStaffReview(Section2.8)Asdiscussed inthecommentsonSection2.3.4,"EffectsofLossofVentilation",

itemf(heatingandventilation calculations) shouldbedeleted.f)St.LucieUnit2SBOWithstand Caabilit(Section3.0)Asdiscussed above,theEDGsofeitherUnit1orUnit2arecapableofsupplying theSBOloadsofbothunits.Therefore, theEDGsfrombothUnit1and2havethecapability andcapacitytobeAACpowersources.g)SummarandConclusions (Section4.0)Basedoncommentsforthepreceding

sections, thissectionshouldberevisedaccordingly.

44'

~~4FloridaPowerandLightTable1St.LucieUnit1Electrical LoadingsUNIT1DESIGNATIONS PDHDSH~FLAHP/KVAKWEMERGENCY LIGHTINGCLASS1EPOWERPANELSCONTAINHENT FAHCOOLERS(2)COHPOHENT COOLIHGWATERPUHPSINTAKECOOLINGWATERPUHPSICWBUILDINGCOOLINGFANSCONTROLROOMA/CAUXILIARY BUILDINGSUPPLYFANSECCSAREAEXHAUSTFANSREACTORCAVITYCOOLINGFANSREACTORSUPPORTCOOLINGFANSEEROOMSUPPLYFANSEEROOMEXHAUSTFANSEEROOMROOFVENTSBATTERYROOHEXHAUSTFANSBATTERYCHARGERSUPSINVERTERS PLANTSECURITYINVERTERS PRESSURIZER HTRS.BACKUPBANKINST'IR(IA)COMPRESSORS COOLINGFORIACOMPRESSORS EDGFUELTRANSFERPUMPSCHARGINGPUHPSMISC.LP'SMISC.PP'S1HVS1A&BORC&01A,18,1C1A,18,1CACC&HVA3A,B,C1HVS4A,481HVE9A,981HVS2A,281HVE3A,381HVS5A,581HVE11,121RV3,1RV4 1RV1,1RV2 1A,18INV.UPS.REC.PL.SEC.INV.*82OR85*1A,18AIRCOMPMOTOR*1A,18*1A,18,1C164,54,535,36,4134,3936,4231,3831,3933,3935,4132,415C,5332,394444A1935,43A626216203608154.4/10.6 7259,49264938102.54.29047.248.6387.5049112111815045060040/7.56050,40204022.17.51.5.2568KVA20KVA20KVA186407.55100125.75149.08123.00369.00451.0042.7044'037.8315.4621.5713.484.391.400.2268.0020.0020F00186.0036.006.704.5082F0086.85109.14123.00369.00451~0042.7044.2032.2015.4621.5713.484.391.400.2268.0020.0020.00186.0036.006.704.5082.00*USEDINTERHITTENTLY

-ONLYPRESSURIZER HEATERSINCLUDEDINTOTAL1693.081608.61UNIT1EDGRATINGSREF.FLO8770-305CONTINUOUS DUTY-"3500KW2000HRSRATING=3730KW7DAYRATING=3790KW4HRSRATING=3860KW30HINRATING-"3960KWU1MAXIMUMVALUE=1693.08KWU2MAXIHUHVALUE=1800.11KWCOMBINEDTOTAL=3C93.19KWCOMBINEDTOTAL=100KOFUNIT1,CONT.RATING SWI

-FloridaPowerandLightTable2St.LucieUnit2Electrical LoadingsUNIT2DESIGNATIONSPDMDSH.FLAHP/KVAKWEMERGENCY LIGHTINGCLASS1EPOWERPAHELSCONTAINMENT FANCOOLERS(2)COMPONENT COOLINGWATERPUMPSINTAKECOOLINGWATERPUMPSICWBUILDINGCOOLINGFANSCONTROLROOMA/CAUXILIARY BUILDINGSUPPLYFANSECCSAREAEXHAUSTFANSREACTORCAVITYCOOLINGFANSREACTORSUPPORTCOOLINGFANSEEROOMSUPPLYFANSEEROOMEXHAUSTFANSEEROOMROOFVENTSBATTERYROOMEXHAUSTFANSBATTERYCHARGERSUPSINVERTERS PLANTSECURITYINVERTERS PRESSURIZER HTRS~PROPSBANKSINST.AIR(IA)COMPRESSORS COOLINGFORIACOMPRESSORS EDGFUELTRANSFERPUMPSCHARGINGPUMPSMISC.LP'SMISC.PP'S2HVS1A&BORC&D2A,2B,2C2A,28,2C2HVE41A,B2HVA/ACC-3A,B,C 2HVS-4A,4B 2HVE9A,982HVS2A,2B2HVE'3A,3B 2HVS5A,5B2HVE11,122RV3,2RV4 2RV1,2RV2 2A,28INV.UPS.REC.VITALA/CCAB.*P1ORP2*2A,28"AIRCOMPMOTOR*2A,2B*2A,28,2C1024,54,534,3936,4211131,423736,3933,3935,4132,4137A,43832,394444A1935,436262161446082.49.468.1,4916573,652447115596.591.429018,4060312.5751141451254506007.555,4015060'20401005050.7568KVA20KVA30KVA150KW607.5312584.9265.84141.00369.00492.006.7049.40112.9750.8113.6621.7777.1741.744.460.6768.0020F0030.00150.0054.006.802.70102.4769.4354.87141.00369.00492.006.7049.40112.9752.9413.6621.7777.1741.744.460.6768.0020.0030F00150.0054.006.802.70102.47*USEDINTERMITTENTLY

-ONLYPRESSURIZER HEATERSINCLUDEDIHTOTAL1800.111775.78UNIT2EDGRATINGSREF.FLO2998-305CONTINUOUS DUl'Y=3685KW2000HRSRATING"-3935KW7DAYRATING=3985KW4HRSRATING<3985KW30MIHRATING-"3985KWU1MAXIMUMVALUE~1693~08KWU2MAXIMUMVALUE=1800~11KWCOMBINEDTOTAL<3493.19KWCOMBINEDTOTAL>95XOFUNIT2,CONT.RATING

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