ML17229B001

Technical Evaluation Rept on 'Submittal-Only' Review of IPEEE at St Lucie Nuclear Plant,Units 1 & 2.

ML17229B001
Person / Time
Site:	Saint Lucie
Issue date:	01/31/1998
From:	KAZARIANS M, MOSLEH A, SEWELL R T ENERGY RESEARCH, INC., External (Affiliation Not Assigned), MARYLAND, UNIV. OF, COLLEGE PARK, MD
To:	NRC OFFICE OF NUCLEAR REGULATORY RESEARCH (RES)
Shared Package
ML17229A999	List: ML17229B000 ML17229B001 ML17229B002
References
CON-NRC-04-94-050, CON-NRC-4-94-50 ERI-NRC-95-504, NUDOCS 9902020322
Download: ML17229B001 (103)

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ERIINRC95-504TCCHNICRLCVRLURTIONRCPORTONTH6"SUBMITTAL-ONLY"86VlGLUOFTH6INDIVIDURLPLRNTCXRMINRTIONOFtXTGRNRLEVENTSRTST.LUCICNUCLGRRPLRNT,UNITS1RND2FINALREPORTCompleted:January1997Final:January1998EnergyResearch,inc.P.O.Box2034Rockville,Maryland20847-2034WorkPerformedUndertheAuspicesoftheUnitedStatesNuclearRegulatoryCommissionOfficeofNuclearRegulatoryResearchWashington,D.C.20555ContractNo.04-94-050r.:."...Vi902020322'~.990g2~awe)C~mm~~;,+PDRADOCV.OSOOOSSSP'PDR ERI/NRC95-504TECHNICALEVALUATIONREPORTONTHE"SUBMITTALQNLY"REVIEWOFTHEINDIVIDUALPLANTEXAMINATIONOFEXTERNALEVENTSATST.LUCIENUCLEARPLANT(UNITSIAND2)FINALREPORTCompleted:January1997Final:January1998M.Khatib-RahbarPrincipalInvestigatorAuthors:R.T.Sewell,M.Kazarians',A.Mosleh-',andA.S.KuritzkyEnergyResearch,Inc.P.O.Box2034Rockville,Maryland20847WorkPerformedUndertheAuspicesofthe..UnitedStatesNuclearRegulatoryCommissionOfficeofNuclearRegula'.oryResearchWashington.D.C.20555ContractNo.04-94-050'azariansandAssociates,425EastColoradoStreet,Suite545.Glendale,CA91205'niversityofMaryland,DeparunentofMaterialsandNuclearEnginceriiig,CollegePark.MD20742 I~ap.%fg,~

TABLEOFCONTENTSEXECUTIVESUMMARYPREFACE...ABBREVIATIONS~~~~~~~~~~~~~~VlXll...XlllINTRODUCTION....1.1PlantCharacterization1.2OverviewoftheLicensee'sIPEEEProcessand1.2.1Seismic1.2.2Fire..1.2.3HFOEvents1.3OverviewofReviewProcessandActivities...1.3.1Seismic.....................1.3.2Fire..1.3.3HFOEventsIinportantInsights....~~~~~~~~~~~~~~234456688~~10101111~~~~~~~~~1314141414151515valuations.....~~~~1616~~~~~~~0~.=..-..-1718181919~~~~~~~~~~~~~~~~~~~~~~~~~~I~~2021~~~~~~~~~~21CONTRACTORREVIEWFINDINGS2.1Seismic.~..2.1.1OverviewandRelevanceoftheSeismicIPEEEProcess.2.1.2SuccessPathsandComponentList..2.1.3Non-SeismicFailuresandHumanActions2.1.4SeismicInput2.1.5StructuralResponsesandComponentDemands2.1.6'creeningCriteria..2.1.7PlantWalkdownProcess2.1.8EvaluationofOutliers2.1.9RelayChatterEvaluation2.1.10SoilFailureAnalysis2.1.11ContainmentPerformanceAnalysis..2.1.12Seismic-FireInteractionandSeismicallyInducedFloodE2.1.13TreatmentofUSIA<52.1.14PeerReviewProcess2.1.15SummaryEvaluationofKeyInsights22Fire.....2.2.1OverviewandRelevanceoftheFireIPEEEProcess...2.2.2ReviewofPlantInformationandWalkdown2.2.3Fire-InducedInitiatingEvents....2.2.4ScreeningofFireZones...2.2.5FireHazardAnalysis2.2.6FireGrowthandPropagation2.2.7EvaluationofComponentFragilitiesandFailureModes2.2.8FireDetectionandSuppression2.2.9AnalysisofPlantSystemsandSequences............EnergyResearch,Inc.fERI/NRC95-504 goI142.32.4~~~~~~~~~~~~~~~~~~~~~~~\~~~\~~~~~N~~~2.2.10CoreDamageFrequencyEvaluation.2.2.11AnalysisofContainmentPerformance....2.2.12TreatmentofFireRiskScopingStudyIssues2.2.13USIA%5IssueHFOEvents2.3.1HighWindsandTornadoes2.3.1.1GeneralMethodology..2.3.1.2Plant-SpecificHazardDataandLicensingBasis2.3.1.3'ignificantChangesSinceIssuanceoftheOperatingLicense2.3.1.4SignificantFindingsandPlant-UniqueFeatures2.3.1.5HazardFrequency2.3.1.6BoundingAnalysis...2.3.2ExternalFlooding...2.3.2.1GeneralMethodology....................2.3.2.2Plant-SpecificHazardDataandLicensingBasis2.3.2.3SignificantChangesSinceIssuanceoftheOperatingLicense2.3.2.4SignificantFindingsandPlant-UniqueFeatures2.3.2.5HazardFrequency2.3.3TransportationandNearbyFacilityAccidents.....2.3.3.1GeneralMethodology....2.3.3.2Plant-SpecificHazardDataandLicensingBasis2.3.3.3SignificantChangesSinceIssuanceoftheOperatingLicense..2.3.3.4SignificantFindingsandPlant-UniqueFeatures2.3.3.5HazardFrequency2.3.4LightningandOthersGenericSafetyIssues(GS1-147,GSI-148andGSI-172).....2.4.1GSI-147,"Fire-InducedAlternateShutdown/ControlPanelInteraction2.4.2GSI-148,"SmokeControlandManualFireFightingEffectiveness".2.4.3GS1-156,"SystematicEvaluationProgram(SEP)"....2.4.4GS1-172,"MultipleSystemResponsesProgram(MSRP)"222222232424242525252526262626272727282828292930303131313135OVERALLEVALUATIONANDCONCLUSIONS....3.1Seismic.3.2Fire...3.3HFOEvents42IPEEEINSIGHTS,IMPROVEMENTS,ANDCOMMITMENTS4.1Seismic.4.2Fire...~~~~~~~~4.3HFOEvents...~~~454547475IPEEEEVALUATIONANDDATASUMMARYSHEETS...........EnergyResearch,Inc.ERI/NRC95-504 1

6REFERENCES................55EnergyResearch,Inc.1VERI/NRC95-504 LISTOFTABLESTable3.1ComparisonofFPL'sSite-SpecificSeismicIPEEEProgramVersusNUREG-1407RecommendedGuidelinesforaReduced-ScopeSeismicEvaluation.40Table5.1ExternalEventsResults49Table5.2SSMSeismicFragility......50Table5.3PWRSuccessPathOverviewTable.........~.....'.51Table5.4PWRSeismicSuccessPaths52Table5.5'WRAccidentSequenceOverviewTable-ForFirePRAOnly..'...........53'Table5.6PWRAccidentSequenceDetailedTable-FirePRAOnly54EnergyResearch,Inc.ERI/NRC95-504 EXECUTIVESUMMARYThistechnicalevaluationreport(TER)documentsa"submittal-only"reviewoftheindividualplantexaminationofexternalevents(IPEEE)conductedfortheSt.LucieNuclearPlant,Units1and2.ThistechnicalevaluationreviewwasperformedbyEnergyResearch,Inc.(ERI)onbehalfoftheU.S.NuclearRegulatoryCommission(NRC).Thesubmittal-onlyreviewprocessconsistsofthefollowing'tasks:Examineandevaluatethelicensee'sIPEEEsubmittaland'irectlyrelevantavailabledocumentation.Developrequestsforadditionalinformation(RAls)tosupplementorclarifythelicensee'sIPEEEsubmittal,asnecessary.Examineandevaluatethelicensee'sresponsestoRAIs.ConductafinalassessmentofthestrengthsandweaknessesoftheIPEEEsubmittal,anddevelopreviewconclusions.ThisTERdocumentsERI'squalitativeassessmentoftheSt.LucieIPEEEsubmittal,particularlywithrespecttotheobjectivesdescribedinGenericLetter(GL)88-20,SupplementNo.4,andtheguidancepresentedinNUREG-1407.FloridaPowerandLightCompany(FPL)isthelicenseeofSt.LucieUnit1(St.Lucie-1)andSt.LucieUnit2(St.Lucie-2).TheSt.LucieIPEEEsubmittalconsidersseismic;fire;andhighwinds,floodsandother(HFO)externalinitiatingevents.TheSt.LucieIPEEEwasperformedandreviewedbylicenseeandcontractorpersonnel.Licensee'sIPEEEProcessWithrespecttotheseismicIPEEE,St.LucieNuclearPlantisassignedtothereduced-scopeseismicreviewcategoryinNUREG-1407.FPLelectedtoimplementasite-specificprogramforconductingtheseismicIPEEEofSt.LucieNuclearPlant.Thesite-specificprogramwasdevelopedprimarilyinresponsetoGL8742forresolutionofUnresolvedShfetyIssue(USI)A-46atTurkeyPoint,Units3and4,andatSt.LucieUnit1.St.LucieUnit2isnotaUSIAA6plant;nonetheless,thesamesite-specificapproachwasproposedforitsseismicIPEEE.Thesite-specificprogramrepresentsa"scaled-back"approachtoUSIA-46resolution.Aftermeetingsandcorrespondence.withFPL,theNRCneverdesignateditsapprovalofthesite-specificprogramforIPEEEresolution.Nonetheless,FPLproceededwithuseofitssite-specificprogramasthebasisforconductingtheseismicIPEEE.Thesite-specificseismicadequacyevaluationsconductedforSt.LucieUnits1and2reliedprimarilyonaplantwalkdownthatfocusedoncomponentanchoragecapabilityandthepotentialforadverseseismic-inducedspatialinteractions..Asafeshutdownequipmentlist(SSEL)wasdevelopedbasedonasuccesspaththatassumeslossofoffsitepower(LQSP).Thesubmittaldoesnotdescribethesuccesspathnordoesitpresentasuccesspathlogicdiagram.Theevaluationapproachdoesnotexplicitlyaddressasmalllossofcoolantaccident(LOCA).AllcomponentsintheSSELthathadnotbeenpreviouslyverifiedashavingadequateseismiccapacitywerewalkeddownbytheseismicreviewteam(SRT)~Theseismicreviewteamuseditsjudgmentinassessingadequacyofseismicanchoragecapacityandinidentifyingspatialinteractionconcerns.Componentswithobviouslyruggedanchoragewerescreenedout;componentswithquestionableseismicanchoragewereEnergyResearch,Inc.viERI/NRC95-504 ra"jg+*<."~"L-E/pl[r.P.'C~w identifiedaspotentialoutliers.Spatialinteractionconcernswerealsoidentifiedaspotentialoutliers.Thepotentialoutlierswereanalyzedinfurtherdetail,inordertomakeafinaloutlierdesignation.Resolutionswereproposedfor,eachdesignatedoutlier.Table3.1ofthisTER'comparesthefeaturesofFPL'ssite-specificIPEEEprogramagainsttheelementsofareduced-scopeevaluationthathavebeenrecommendedinNUREG-1407.ThetableindicatesthatFPL'sprogramaddressesonlyasubsetoftherecommendeditems/guidelines.Themostsignificantdifferencesinthetwoevaluationapproachesarejudgedtobe:alesserscopeofcomponentsintheFPLapproach;alimitedtreatmentofhumanactionsintheSt.Luciestudy;andnotreatmentofcontainmentsystemsintheFPLprogram.Inaddition,theformatfordocumentingtheseismicIPEEEhasnotfollowedtherecommendationsofNUREG-1407.Itisimportanttonotethat-basedonfindingsofasiteaudit(whichinvolvedaninspectionofFPL'sTurkeyPointNuclearPlant),andpendingfollow-upactionbythelicensee-theNRChasreachedclosureonUSIAA6forSt.Lucie-1.Toasignificantdegree,theNRC'sresolutionofUSIA46concernshasservedasdirectbasisforformulatingcorrespondingreviewfindingsinthisTERforsimilarIPEEEconcernsatSt.Lucie,Units1and2.ForthefireIPEEE,thelicenseehasconductedanextensiveanddetailedanalysisoffireeventsatSt.Lucie.AppendixRdocumentationhasbeenusedtoestablishfire-relatedplantfeatures,aswellasfirezonesandareas.InadditiontosafeshutdownequipmentdefinedbyAppendixR,equipmentmodeledintheprobabilisticriskassessment(PRA)wereincludedinthefireanalysis.Tosupportthefireanalysis,thelicenseehasconductedawalkdownofthefacility,usingengineersfamiliarwiththeplantandwithfireanalysis.ThefireIPEEEfreezedateisDecember1993;thisdatehasbeenusedasthecut-offdateforalldocumentationdescribingtheplant.Aconsultingfirmwithe'xperienceinfireriskanalysishasassistedFPLanalystsinthepreparationofthefireanalysis.Thelicenseehasusedfire-inducedvulnerabilityevaluation(FIVE)methodologyandassociatedfirefrequencyandfailuredatatoevaluatethefirerisk.Simplemodelshavebeenusedtoevaluatefiredamageandhumanrecoveryactions.Tokeeptheanalysissimple,noneoftheanalysespresentedtakesintoaccountthespecificfireprotectionfeaturesforagivenarea,northespecificoperatoractionsforafirescenario.Forredundanttrainfailurefrequencyevaluation,thePRAmodelsanddataoftheplanthavebeenused.ThelicenseehassubmittedaplanforAppendixRcomplianceandhasaddressedthemajorityoftheissuesraisedaspartofthatplan,withsupportinganalysis.SomefireareasandredundantcablesandequipmentareprotectedbyThermo-lag.TheeffectivenessofThermo-laganditsimportanceatSt.LucieNuclearPlantarecurrentlyunderinvestigationbythelicensee.FortheHFOIPEEE,thegeneralmethodologyutilizedbythelicenseeconformstothatpresentedinNUREG-1407fortheanalysisofotherexternalevents.Thelicenseehasperformedadetailedanalysisofhighwinds,externalflooding,andtransportationandnearbyfacilityaccidenthazards.Additionally,theotherexternaleventshavebeenevaluatedtoensurethattherearenohazardsuniquetotheplant.Amongtheseotherexternalevents,lightninghasbeenanalyzedingreaterdetail.KeyIPEEEFindingsFromtheseismicIPEEE,theprincipalfindingsconsistofqualitativewalkdowninsights,andfewquantitativefindingshavebeenreported.TheseismicadequacyevaluationforSt.Lucie-1revealedanumberofoutliersforwhichsafetyenhancementshavebeenproposedinresponsetoUSIA-46.Inaddition,thelicenseeisundertakingfollow-upactionstoimplementastrictseismichousekeepingprograminresponsetoconcernsidentifiedbytheNRCinitsUSIA-46reviewprocess.EnhancementsforIPEEE-onlycomponents(i.'e.,componentsoutsidethescopeofUSIAA6,butwithinthescopeofIPEEE)wereEnergyResearch,Inc.viiERI/NRC95-504

It><."pihAM~~~VWF" notaddressed.ForSt.Lucie-2,therewerenoconcernsidentifiedfortheequipment,providedawalkdownofwall-mountedtransformerswouldbeperformed,andthatsuchtransformerswouldbesecuredasnecessary.Again,noenhancementswereaddressedforIPEEEwnlycomponents.Withrespecttofireevents,thelicenseehasreachedtheoverallconclusionthattherearenosignificantfirevulnerabilitiesatSt.Lucie.Withtheexceptionofthecontrolroom,cablespreadingroomandthe"B"switchgearroom,allfirezonesandareaswerescreenedoutbasedona10perreactor-year(ry)coredamagefrequency(CDF)criterion.TheCDFsforcontrolroomfireswereconcludedtobe7.49F10'/ryand5.90x10'/ryforUnits1and2,respectively.Forthecablespreadingrooms,thecoredamagefrequenciesweredeterminedtobe6.95x10'/ryand5.64x10'/ryforUnits1and2,respectively.Forbothareas(i.e.,controlroom'andcablespreadingroom),thelicenseecitesseveralconservativeassumptionsinfireoccurrencerateandfireseverity,andconcludesthatthesetwoareasdonotposeavulnerability.TheCDFforafireinthe"B"switchgeairooaiwasconcludedtobe4.30x10'/ryand4.48x10~/ryforUnits1and2,respectively.Firepropagationmodelinghasbeenperformedforthisarea,andthelicenseehasconcludedthatafirewouldnotpropagatethroughouttheroom.WithrespecttoHFOevents,thesubmittalstatesthattheotherexternaleventsdonotpresentasignificantrisktotheplant.ThisconclusionhasbeenreachedwithoutperformingadetailedPRA,andnoHFOcoredamagefrequencyisreportedfortheplant.Thehazard-specificconclusionsoftheanalysisareasfollows:-Ufdff<<IfdgfdRIPI(SRP)criteria,orthehazardoccurrencefrequencywasdemonstratedtobeacceptablylow.Unit2designwasfoundtoconformtotheSRPcriteria,andassuch,itwasconcludedthathighwinds/tornadoesdonotposeasignificantthreattotheunit.R.IU'dfgdIURRgtGuide(R.G.)1.59andSRPcriteria,andassuch,itwasconcludedthatexternalfloodsposenosignificantriskofasevereaccident.-TheSt.LucieUnits1and2designsweredeterminedtoconformtoSRPcriteria,andassuch,itwasconcludedthattransportationandnearbyfacilityaccidentsposenosignificantriskofasevereaccident.Lucie,andtheimpactoflightningonplantriskisboundedbytheinternaleventsanalysis.NopotentialvulnerabilitieswithrespecttoanyHFOeventwereidentified.GenericIssuesandUnresolvedSafetyIssuesForseismicevents,USIA45("ShutdownDecayHeatRemovalRequirements")isapplicabletoSt.LucieNuclearPlant,butwasnotaddresseddirectlyinthelicensee'sIPEEEsubmittalreport.Thesite-specificseismicadequacyevaluationstudiesperformedforSt.Lucie-1andSt.Lucie-2consideredasuccesspaththatdependsonseismiccapabilitynftheauxiliaryfeedwater(AFW)system;seismiccapabilityofotherdecayheatremovalsystems(feedandbleedcooling,andresidualheatremoval)weren'otspecificallyaddressed.Thecondensatestoragetank(CST)wastheonlycomponentoftheAFWsystemthatwasactuallyincludedintheseismicevaluation;thesubminalnotesthatAFWpumpswerepreviouslyreviewedEnergyResearch,Inc.vniERI/NRC95-504 forseismicadequacyaspartofGL81-14.InresponsetoanRAIissuedbytheNRCaspartoftheUSIAWreviewprocess,thelicenseehasindicatedthattherealsoexistsaseismicallyqualifiedpathforfeed-and-bleedcoolingattheplant.AspartofthefireIPEEE,thelicenseehasaddressedbothSandiafireriskscopingstudyissuesandUSIA45issues.Forbothcases,thelicenseehasdealtwiththeissuesanddoesnotidentifyanyoutstandingproblemareas.However,thepossibilityofanearthquakecausingafirewasnotaddressed.ForareaswithThermo-lag,thelicenseehascheckedwhethertheprotectionintendedbyThermo-lagisnecessarytoreducethefireCDFbelow10~/ry.Forsom'ecompartments,ithasbeenconcludedthatevenwithoutthepresenceofThermo-lag,theCDFcanbebelow10~/ry.WithrespecttoHFOevents,thesubmittaldoesnotdescribeanyformalanalysisofothersafetyissues.EventhoughadirectdiscussionofGenericIssue(GI)-103,"DesignforProbableMaximumPrecipitationPMP),"wasnotprovidedinthesubmittal,FPLnotedthattherearenoconcernsassociatedwiththesitewoodinglevelsandroofpondingthatcouldaccompanyincreased(beyonddesignbasis)PMPlevels.SomeinformationisalsoprovidedintheSt.LucieIPEEEsubmittalwhichpertainstogenericsafetyissue(GSI)-147,GSI-148andGS1-172.VulnerabilitiesandPlantImprovementsThelicenseemakesageneralconclusionintheIPEEEsubmittalthattherearenovulnerabilitiestosevereaccidentriskfromexternalinitiators.However,safetyenhancementsrelatedtospecificexternalinitiatorshavebeenidentifiedandproposedforresolution.Forseismicevents,theplant-specificseismicadequacyevaluationsforSt.LucieNuclearPlant,Units1and2,haverevealedanumberofnoteworthyseismicfindings,includingsomeidentifiedseismicoutliers,andhaveproposedrelevantplantimprovementsasneeded.Thenotedconditionsaresummarizedbelow:St.LucieUnitI:Duringthewalkdowns,fiveanchoragesandthebracingofthecomponentcoolingwatersurgetankplatformwereidentifiedasconcernsbytheSRT.Inadditiontothesefiveanchorageconcerns,sixadditionalanchorageconcernswereidentifiedbyFPLforsimilarcomponentsindifferentequipmenttrains.Plantimprovementswereproposedtodisposeoftheseconcerns.Threeseismicinteractionconcernswereobservedanddocumented,asweresomecasesofpoorseismichousekeeping.InresponsetotheNRC'sUSIA<6reviewprocess,thelicenseeisimplementingaprogramofstrictseismichousekeeping.~Sr.LucieUnit2:Twoseismicinteractionconcernswereobservedanddocumented.Bothoftheseissueswereultimatelyevaluatedandresolved.Aconcernwasalsonotedpertainingtowhetherornotthemountingofsomeinternalcoilsinanenergizedtransformerwasseismicallyadequate.Thisconcern.wasinvestigatedduringanoutage,anditwasfoundthatthemountingwasadequate.EnergyResearch,Inc.ixERI/NRC95-504 J~~I1r Itwasalsostatedintheseismicevaluationthatawalkdownofwalltransformersneededtobeperformed,todeterminewhetherornotthesetransformerswouldneedtobesecured.Forfireevents,eventhoughthelicenseehasconcludedthattherearenofirevulnerabilities;nevertheless,ithasidentifiedseveralcorrectiveactionstoimprovefiresafetyattheplant.Thecorrectiveactionsinclude:Ananalysisofusingthecross-tiebetweenthetwounitstofurtherincreasetheavailabilityofpowertotheaffectedunitundercertainfirescenarios,andarevisionoftheproceduresbasedontheresultsofthisanalysis.Revisethecurrentfireprotectionprocedurestoensurethataroll-updoorbetweennon-safetyswitchgearsiskeptclosedatalltimes.Ananalysisoffirescenariosinthe"B"switchgearroomtoreducetheCDFcontributionforthisareatobelow10~/ry,andarevisionoftheproceduresbasedontheresultsofthisanalysis.WithrespecttoHFOevents,allpotentialhazardsweredismissedasnon-significantriskcontributors,withoutperformingadetailedPRA,andnovulnerabilitiestosevereaccidentswereidentified.ObservationsIntheseismicIPEEE,thesite-specificprogramfors'eismicadequacyevaluationsofSt.LucieUnits1and2addressesonlyasubsetoftheelementsspecifiedinNUREG-1407asrecommendeditemsthatshouldbeconsideredintheseismicIPEEEofareduced-scopeplant.Theevaluationsdo,nonetheless,addresssomemeaningfulIPEEE-relatedconcerns,andhaveresultedinasmallnumberofplantseismicsafetyenhancements.GiventheNRC'sresolutionofrelatedUSIAA6concernsforSt.Lucie-l,thefollowingareconsideredtobethemostsignificantremainingweaknessesoftheseismicIPEEEsubmittal:1.TheSSELisdeficient;r2.Aseismiccontainmentperformanceassessmentwasnotconducted;3.Thetreatmentofhumanactionsisdeficient;4.Thesubmittaldoesnotprovideadequatedocumentationofseismic-fire/floodinteractionconcerns,includingcomponent-specificwalkdownfindings;'.TheseismicIPEEEisincompletewithrespecttoreduced-scopeevaluationrecommendationsfoundinNUREG-1407;and6.TheseismicIPEEEsubmittalisnotdocumentedinaccordancewiththeformatrecommendedinNUREG-1407,AppendixC.InthefireIPEEE,thelicenseehasexpendedaconsiderableeffortinthepreparationofthefireanalysis,andhaspresenteditinasummaryforminitsIPEEEsubmittal.TheIPEEEreportcomplieswiththeconditionssetforthinNUREG-1407.ThelicenseehasemployedapropermethodologyanddatabaseforEnergyResearch,Inc.ERI/NRC95-504 yl conductingthefireanalysis.Basedonthedatapresented,notwithstandingsomeoftheweaknessesofthesubmittal,itcanbeconcludedthatthelicenseehasconductedareasonableanalysis.Theoverallresultsarewithintherangeofconclusionsreachedinotherpressurizedwaterreactor(PWR)fireriskstudies.WithrespecttoHFOevents,thesubmittalreliesmostlyonqualitativereasoningtoscreenoutallsuchevents.Ingeneral,theanalysesareadequatelysupported,andfollowacceptedpracticeandtheoverallNUREG-1407guidelines.Insomecases,however,engineeringjudgmentsaremadewithoutsubstantiation.Themostimportantcasesthatrequireadditionalsupportareintheareaofhighwindsandtornadoes,particularlywithrespecttohazardtoUnit1structures.EnergyResearch,Inc.XiERI/NRC95-504 PREFACETheEnergyResearch,Inc.,teammembersresponsibleforthepresentIPEEEreviewdocumentedherein,include:htnhR.T.SewellM.KazariansA;MoslehM.Khatib-Rahbar,PrincipalInvestigator,ReportReviewA.S.Kuritzky,IPEEEReviewCoordinationandIntegrationR.T.Sewell,ReportIntegrationDr.JohnLambright,ofLambrightTechnicalAssociates,contributedtothepreparationofSection2.4followingthecompletionofthedraftversionofthisTER.ThisworkwasperformedundertheauspicesoftheUnitedStatesNuclearRegulatoryCommission,OfficeofNuclearRegulatoryResearch.ThecontinuedtechnicalguidanceandsupportofvariousNRCstaffisacknowledged.EnergyResearch,Inc.xnERI/NRC95-504 ABBREVIATIONSAFWCCWCDFCECFRCSTDBEDCEPRIERIFCIAFECRFIVEFPLFRSSFSARGlGIPGLGSIHCLPFHFOHVACICWIPE'PEEEIRSLLNLLOCALOSPMCCMFWMLWNRCOLPGAPMHPMPPMSPORVPRAPWRRABRAIAuxiliaryFeedwaterComponentCoolingWaterCoreDamageFrequencyCombustionEngineeringCodeofFederalRegulationsCondensateStorageTankDesignBasisEarthquakeDirectCurrentElectricPowerResearchInstituteEnergyResearch,Inc.FireCompartmentInteractionAnalysisFloridaEastCoastRailwayFireInducedVulnerabilityEvaluationMethodFloridaPowerandLightCompany.FireRiskScopingStudyFinalSafetyAnalysisReportGenericIssueGenericImplementationProcedure(SQUG)-GenericLetterGenericSafetyIssueHighConfidenceofLowProbabilityofFailure(Capacity)HighWinds,FloodsandOtherExternalInitiatorsHeating,VentilationandAirConditioningIntakeCoolingWaterIndividualPlantExaminationIndividualPlantExaminationofExternalEventsIn-StructureResponseSpectrumLawrenceLivermoreNationalLaboratoryLossofCoolantAccidentLossofOffsitePowerMotorControlCenterMainFeedwaterMeanLowWaterNuclearRegulatoryCommissionOperatingLicensePeakGroundAccelerationProbableMaximumHurricaneProbableMaximumPrecipitationProbableMaximumSurgePower-OperatedReliefValveProbabilisticRiskAssessmentPressurizedWaterReactorReactorAuxiliaryBuildingRequestforAdditionalInformationEnergyResearch,Inc.xiiiERI/NRC95-504 RCPRCSRLESERSISMASMMSNLSQUGSRPSRTSSESSELSSRAPSt.Lucie-1St.Lucie-2TERUSIReactorCoolantPump'ReactorCoolantSystemReviewLevelEarthquakeStaffEvaluationReportSafetyInjectionSeismicMarginAssessmentSeismicMarginMethodologySandiaNationalLaboratoriesSeismicQualificationUtilityGroupStandardReviewPlanSeismicReviewTeamSafeShutdownEarthquakeSafeShutdownEquipmentListSeniorSeismicReviewandAdvisoryPanelSt.LucieNuclearPlant,UnitISt.LucieNuclearPlant,Unit2TechnicalEvaluationReportUnresolvedSafetyIssueEnergyResearch,Inc.x]vERI/NRC95-504 004, (5I~~~1INTRODUCTIONThistechnicalevaluationreport(TER)documentstheresultsofthe"submittalwnly"reviewoftheindividualplantexaminationofexternalevents(IPEEE)fortheSt.LucieNuclearPlant,Units1and2[1].Thistechnicalevaluationreview,conductedbyEnergyResearch,Inc.(ERI),hasconsideredvariousexternalinitiators,includingseismicevents;fires;andhighwinds,floods,andother(HFO)externalevents.TheU.S.NuclearRegulatoryCommission(NRC)objectiveforthisreviewistodeterminetheextenttowhichtheIPEEEprocessusedbythelicensee,FloridaPowerandLight(FPL),meetstheintentofGenericLetter(GL)88-20,SupplementNo.4[2].InsightsgainedfromtheERIreviewoftheIPEEEsubmittalareintendedtoprovideareliableperspectivethatassistsinmakingsuchadetermination.Thisreviewinvolvesaqualitativeevaluationofthelicensee'sIPEEEsubmittal,developmentofrequestsforadditionalinformation(RAIs),evaluationofthelicenseeresponsestotheseRAIs,andfinalizationofthisTER.TheemphasisofthisreviewisondescribingthestrengthsandweaknessesoftheIPEEEsubmittal,'articularlyinreferencetotheguidelinesestablishedinNUREG-1407[3].Numericalresultsareverifiedforreasonableness,notforaccuracy;however,whenencountered,numericalinconsistenciesarereported.ThisTERcomplieswiththerequirementsofNRC'scontractortaskorderforanIPEEEsubmittal-onlyreview.TheremainderofthissectionoftheTERdescribestheplantconfigurationandpresentsanoverviewofthelicensee'sIPEEEprocessandinsights,aswellasthereviewprocessemployedforevaluationoftheseismic,fire,andHFO-eventssectionsoftheSt.LucieIPEEE.Sections2.1to2.3ofthisreportpresent.ERI'sfindingsrelatedtotheseismic,fire,andHFOreviews,respectively.Sections3.1to3.3summarizeERI'sconclusionsandrecommendationsfromtheseismic,fire,andHFOreviews,respectively.Section4summarizestheIPEEEinsights,improvements,andlicenseecommitments.Section5includescompletedIPEEEdatasummaryandentrysheets.Finally,Section6providesalistofreferences.St.LucieNuclearPlantisatwo-unitnuclearpowerfacilitylocatedonHutchinsonIsland,abouthalfwaybetweenthetownsofFt.PierceandStuart,ontheeastern(Atlantic)coastofpeninsularFlorida.EachoftheSt.Lucieunitsisatwo-loopCombustionEngineering(CE)pressurizedwaterreactor(PWR),witharatedfull-powercorethermaloutputof2,700MWtandanetelectricaloutputof890MWe.Thecontainmentforeachunitconsistsofasteelvesselsurroundedbyareinforced-concretebiologicalshieldbuilding;anannularspaceexistsbetweenthesteelvesselandtheshieldbuilding.St.LucieUnit1wentintocommercialoperationduringDecember1976,andSt.LucieUnit2begancommercialoperationduringAugust1983.Thetwounitsdonotphysicallyshareanymajorcommonareas.Eachunithasitsownturbinebuilding,~reactorauxiliarybuilding(RAB),andcontainmentbuilding.Thereisonecontrolroomandonecablespreadingroomperunit.ThesetworoomsaresituatedattheupperelevationsoftheRAB.Theauxiliaryshutdownpanelsarelocatedinthe"B"switchgearroom.Fromasystemsstandpoint,thetwounitsdonotshareanymajorfunctional-relatedelements,exceptforoffsitepowerfacilities,across-tieforelectricalpower,andatechnicalsupportcenterwhichislocatednextEnergyResearch,IncERI/NRC95-504 totheUnit1controlroom.Eachunithastwodieselgenerators,anauxiliaryfeedwater(AFW)system,twomotordrivenmainfeedwater(MFW)pumps,highandlowpressuresafetyinjection(SI)systems,acomponentcoolingwater(CCW)system,andanintakecoolingwater(ICW)system.BothCCWandICWsystemsareneededtopreventreactorcoolantpump(RCP)sealfailure.TheAFWsystemincludestwomotordrivenpumps,aswell.asonesteam4rivenpumpthatneedsdirectcurrent(DC)powertostart,andcanbeoperatedinamanualmode.Thedesignbasisearthquake(DBE)peakgro'undacceleration(PGA)forSt.LucieNuclearPlantis0.1g(horizontalandvertical)forthesafeshutdownearthquake(SSE).TheDBEspectralshapesaredifferentforthetwounits;Unit1wasdesignedforaHousnerspectralshape,andUnit2wasdesignedforaRegulatoryGuide(R.G.)1.60spectralshape.CategoryIstructuresforbothunitsarefoundedonCategory-Ifill,underlainbycementedsandsandsandylimestones.FortheIPEEEstudy,acutoffdateofDecember1993wasusedforestablishingplantconfigurationandoperatingconditions.1.2.1SeismicAsdocumentedinNUREG-1407,forseismicIPEEEpurposes,St.Lucieisbinnedintothereduced-scopeevaluationcategory.Ratherthanimplementingareduced-scopeseismicevaluation,FPLhaspursuedtheuseofasite-specificprogramforconductingtheseismicIPEEEofSt.LucieNuclearPlant.Thissite-specificprogramwasdevelopedprimarilyfortreatmentofUnresolvedSafetyIssue(USI)A%6,andrepresentsa"scaled-back"approachtoachievingtheobjectivesofGL8742[4].ThejustificationscitedbyFPLforperformingascaled-backanalysisinclude:(a)verylowprobabilityofhavinganearthquakeattheSSElevelatFPL'splants;and(b)verylowvaluesofpotentialoffsitereleasesandpotentialriskreductionsgiventhepostulatedaccidentscenariosandseismichazards.FPL'sscaled-backsite-specificseismicadequacyprogramwasapproved,inconcept,bytheNRCforthepurposeofaddressingUSIA46.However,onceFPLsubmittedtheactualseismicadequacyevaluationstudy[5],theNRCidentifiedanumberofconcernsandpotentialdeficiencieswiththeapproach.TheNRC'sconcernsaredocumentedinitsstaffevaluationreport(SER)pertainingtoUSIA-46resolution[6].AsiteinvestigationbytheNRCwasheldatFPL'scorporateheadquartersandattheTurkeyPointNuclearPlantduringtheweekofDecember4-8,1995tohelpresolvetheconcernsnotedintheNRC'sSER.ManyoftheNRCconcernswerealleviatedbywayofdiscussionswiththelicenseeanditsconsultants;forotherconcerns,thelicenseehasagreedtoimplementcorrectiveactionsidentifiedbytheNRC.TheseitemsaredocumentedinanNRCsupplementalsafetyevaluationreport(SSER)[7],whereintheNRCstatesthatclosurehasbeenreachedonalloftheSERopenitemsforbothTurkeyPointandSt.Lucie.WithrespecttotheseismicIPEEE,theNRChadconcernswiththeuseoftheFPLsite-specificapproachasabasisforresolvingsevereaccidentvulnerabilityissues.TheNRCnevergaveitsapprovalofFPL'sprogramfortreatmentoftheseismicIPEEE.Nonetheless,FPLproceededwithuseofthesite-specificseismicadequacyevaluationsforUSIA<6asthebasisforconductingtheseismicIPEEE.Sincethelicensee'sseismicIPEEEisessentiallyidenticaltoitsUSIAA6seismicadequacyevaluationstudy,andbecausemanyoftherecommendationsoutlinedinNUREG-1407forareduced-scopeIPEEEEnergyResearch,Inc.ERI/NRC95-504 lj1 areachievedifanacceptableUSIAA6evaluationhasbeenperformed,theNRC'sSERandSSERdetermines(toasignificantdegree)thatacorrespondingreviewconclusionbemadeforsimilarIPEEEconcerns.Hence,thisTERindicateswhereareviewfindinghas'beenbasedonNRC'ssafetyevaluationforUSIA46.ItisimportanttopointoutthatonlySt.Lucie-1isaUSIA46plant.ThedesignbasisandseismicqualificationemployedforSt.Lucie-2aresimilartocurrentNRClicensingrequirements.Therefore,aseismicadequacyevaluationwasnotrequiredforSt.Lucie-2aspartofUSIA46resolution.Still,FPLundertooksuchanevaluationforaddressingtheseismicIPEEE.FPL'sapproachtoseismicevaluationreliesprimarilyonplantwalkdownsandontheuseofseismicreviewteam(SRT)judgment,supplementedwithcalculations,asneeded,forresolvingoutliers.Thewalkdownshaveaddressedthefollowingitems:equipmentseismiccapacityversusdemand,equipmentconstructionadequacy,anchorageadequacy,seismicspatialinteractionconcerns,andseismichousekeepingconcerns.ThemainoverallelementsofFPL'ssite-specificseismicadequacyevaluationinclude:ProjectplanningSelectionoftheseismicreviewteamPreparatoryworkpriortowalkdownSeismiccapabilitywalkdownsLimitedseismicmarginassessment(SMA)calculationworkResolutionofoutliersPeerreviewDocumentationFPL'sapproachtotheseaspectsoftheseismicIPEEEprocessforSt.LucieNuclearPlantisdiscussedinSection2.1.FPLfoundnoseismicvulnerabilitiestopotentialsevereaccidents,butdidreportasmallnumberofoutlierstoberesolved.Additionally,inresponsetotheNRC'sUSIA46reviewprocess,FPLagreedtoresolveanadditionalconcernrelatedtoseismichousekeepingprocedures.1.2.2FireOverall,thelicenseehasconcludedthattherearenosignificantfirevulnerabilitiesatSt.Lucie.Withtheexceptionofthecontrolroom,cablespreadingroomandthe"B"Switchgearroom,allfirezonesandareaswerescreenedoutbasedona10perreactor-year(ry)coredamagefrequency(CDF)criterion.Thelicenseecitesseveralconservativeassumptionsinfireoccurrencerateandfireseverityforthecontrolroomandcablespreadingroom,andconcludesthatthesetwoareasdonotposeavulnerability.Firepropagationmodelinghasbeenperformedforthe"B"switchgearroomtoverifythatthisareadoesnotneedtobeconsideredasavulnerability.ThelicenseehasaddressedtheSandiafireriskscopingstudy(FRSS)issuesandUSIA<5concerns.Forbothcases,thelicenseehasdealtwiththeissuesanddidnotidentifyanyoutstandingproblemareas.However,thepossibilityofanearthquakeleadingtoafirewasnotaddressed.EnergyResearch,Inc.ERI/NRC95-504 ForareaswithThermo-lag,thelicenseehascheckedwhethertheprotectionintendedbyThermo-lagisnecessarytoreducethefireCDFtobelow10~/ry.Forsomecompartments,ithasbeenconcludedthatevenwithoutthepresenceofThermo-lag,theCDFisbelow10/ry.1.2.3HFOEventsThegeneralmethodologyutilizedinthestudyconformstothatpresentedinNUREG-1407fortheanalysisofotherexternalevents.Itconsistsofthefollowingsteps:1.Reviewofplant-specifichazarddataandlicensingbases.2.Determinationofconformanceoftheplantrisksignificantstructurestothe1975StandardReviewPlan(SRP)[8]criteria.3.Screeningofplantstructuresthat'meettheSRPcriteriaforaspecifichazard.4.DeterminationofthehazardfrequencyforthosestructuresthatdonotmeettheSRPcriteria.5.PerformingaboundinganalysisifthehazardfrequencycalculatedinStep4isfoundtobehigh.6.Performaprobabilisticriskassessment(PRA),ifnecessary.Thelicenseehasperformedadetailedanalysisofthehighwinds,externalflooding,andtransportationandnearbyfacilityaccidenthazards.Additionally,thepotentialforexternaleventshasalsobeenevaluatedtoensurethethattherearenohazardsuniquetotheplant.TheobjectivesforthisassessmentareconsistentwiththoseofGL88-20,Supplement4[2].FPLpersonnelhavebeendirectlyinvolvedinallaspectsofthedevelopment,quantification,anddocumentationoftheanalysis.ThemajorfindingoftheanalysisisthattherearenovulnerabilitiestosevereaccidentriskfromHFOevents.InitsqualitativereviewoftheSt.LucieIPEEE,ERIfocusedonthestudy'scompletenessinreferencetoNUREG-1407guidance;itsabilitytoachievetheintentandobjectivesofGL88-20,SupplementNo.4;itsstrengthsandweaknesseswithrespecttothestaff-the-art;andtherobustnessofitsconclusions.Thisreviewdidnotemphasizeconfirmationofnumericalaccuracyofsubmittalresults;however,anynumericalerrorsthatwereobvioustothereviewersarenotedinthereviewfindings.Thereviewprocessincludedthefollowingmajoractivities:CompletelyexaminetheIPEEEsubmittalandrelateddocumentsDevelopapreliminaryTERandRAIsExamineresponsestotheRAIsFinalizethisTERanditsfindingsBecausetheseactivitieswereperformedinthecontextofasubmittal-onlyreview,ERIdidnotperformasitevisitoranauditofeitherplantconfigurationordetailedsupportingIPEEEanalysesanddata.EnergyResearch,Inc.ERI/NRC95-504 4g0 Consequently,itisimportanttonotethattheERIreviewteamdidnotverifywhetherornotthedatapresentedintheIPEEEmatchestheactualconditionsattheplant,andwhetherornottheprogramsorproceduresdescribedbythelicenseehaveindeedbeenimplementedatSt.Lucie.1.3.1SeismicInconductingtheseismicreview,ERIgenerallyfollowedtheemphasisandguidelinesdescribedinthereport,IndividualPlantExaminanonofExternalEvents:ReviewGuidance[9],forreviewofaseismicmarginassessment,andtheguidanceprovidedintheNRCreport,IPEEEStepIReviewGuidanceDocument[10].Inaddition,onthebasisoftheSt.LucieIPEEEsubmittal,ERIcompleteddataentrytablesdevelopedintheLawrenceLivermoreNationalLaboratory(LLNL)documententitled"IPEEEDatabaseDataEntrySheetPackage"[11].InitsSt.LucieIPEEEseismicreview,ERIexaminedthefollowingdocuments:Sections1,2,3,4.8,6,7,and8oftheIPEEEsubmittal[1]~TheUSIA<6seismicadequacyevaluationofSt.LucieUnit1[5]~TheseismicadequacyevaluationstudyofSt.LucieUnit2[12]~Section3.7.7oftheindividualplantexamination(IPE)submittalforSt.LucieUnits1and2[13]~TheNRC'sSER[6]andsupplementalSER(SSER)[7]oftheUSIA-46submittalsforTurkeyPoint,Units3and4,andSt.LucieUnit1~Thelicensee'sresponse[14]totheRAIsgeneratedaspartoftheinitialsubmittalreviewTheIPEEEsubmittal[1]itselfcontainsonlyonepageofdiscussionrelatedtoseismicevaluation.Considerationoftheseismicadequacyevaluationstudies(References[5,12])andtheNRC'sevaluation[6,7]ofthelicensee'sUSIA-46submittalconstitutedthemostsignificantelementofthepresentseismicreview.ThechecklistofitemsidentifiedinReference[9]wasgenerallyconsultedinconductingtheseismicreview.Someoftheprimaryconsiderationsintheseismicreviewhaveincluded(amongothers)thefollowingitems:Wereappropriatewalkdownproceduresimplemented,andwasthewalkdowneffortsufficienttoaccomplishtheobjectivesoftheseismicIPEEE?Wasthedevelopmentofsuccesspathsperformedinamannerconsistenttoprescribedpractices?Wererandomandhumanfailuresproperlyconsideredinsuchdevelopment?Werecomponentdemandsassessedinanappropriatemanner,usingvalidseismicmotioninputandstructuralresponsemodeling,asapplicable?Wasscreeningappropriatelyconducted?Werecapacitycalculationsperformedforameaningfulsetofcomponents,andarethecapacityresultsreasonable?Doesthesubmittal'sdiscussionofqualitativeassessments(e.g.,containmentperformanceanalysis,seismic-fireevaluation)reflectreasonableengineeringjudgment,andhaveallrelevantconcernsbeenaddressed?EnergyResearch,Inc.ERI/NRC95-504

~HastheseismicIPEEEproducedmeaningfulfindings,hasthelicenseeproposedvalidplantimprovements,andhaveallseismicriskoutliersbeenaddressed?Itisimportanttonotethat,inanumberofinstances,IPEEEreviewfindingshavebeenreportedonthebasisofconsistencywithrelatedfindingsinNRC'sSER[6]andSSER[7]forUSIA46,ratherthanonthebasisofaseparatereviewforIPEEE.1.3.2FireDuringthistechnicalevaluation,ERIreviewedthefire-eventsportionoftheIPEEEforcompletenessandconsistencywithpastexperience.ThisreviewwasbasedonconsiderationofSections1,2,4,6,7and8ofReference[1],andSectionIIofReference[14].Inaddition,asetoflayoutdrawings[15,16]pertainingtofireprotectionwereavailableforreview.TheguidanceprovidedinReferences[9,10]wasusedtoformulatethereviewprocessandorganizationofthisdocument.ThedataentrysheetsusedinSection5hav'ebeencompletedinaccordancewithReferencefl1].TheprocessimplementedforERI'sreviewofthefireIPEEEincludedanexaminationofthelicensee'smethodology,data,andresults.ERIreviewedthemethodologyforconsistency'withcurrentlyacceptedandstate-of-the-artmethods.ThedataelementofafireIPEEEincludes,amongothers,suchitemsas:CableroutingFirezone/areapartitioningFireoccurrencefrequenciesEventsequencesFiredetectionandsuppressioncapabilitiesForafewfirezones/areasthatweredeemedimportant,ERIalsoverifiedthelogicaldevelopmentofthescreeningjustifications/arguments(especiallyinthecaseoffire-zonescreening)andthecomputationsforfireoccurrencefrequenciesandCDFs.Ratherthanperformacompletelyindependentsetofcalculations,however,thereviewteamuseditsexperienceandcomparisonsofotherplantsandfireevaluationresults,inordertojudgetheaccuracyandcompletenessoftheinformationprovidedbythelicensee.Specialattentionwasdirectedto:(1)thescreeningmethodology,becauseatrendtoprematurelyscreenoutpotentiallysignificantareasortoinadequatelyjustifyscreeningoutanarea,hasemergedasacommonproblemamongpastfirePRAsandIPEEEanalyses;and(2)thelicensee'sassumptions,becausetheresults'fmanystudiesareundulyinfluencedbyassumptionsmadetosimplifyorintroduceconservatisms.1.3.3HFOEventsThereviewprocessforHFOeventscloselyfollowedtheguidanceprovidedinthereportentitledIPEEEStepIReviewGuidanceDocument[10].Thisprocessinvolvedexaminationsofthemethodology,thedataused,andtheresultsandconclusionsderivedinthesubmittal.Sections1,2,5,6,7and8oftheIPEEEsubmittal[1],andlicenseeresponsestoRAIs[14],wereexaminedinthisHFO-eventsreview.TheIPEEEmethodologywasreviewedforconsistencywithcurrentlyacceptedpracticesandNRCrecommendedprocedures.Specialattentionwasfocusedonevaluatingtheadequacy"ofdatausedtoestimatethefrequencyofHFOevents,'andonconfirmingthatanyanalysisofSRPconformancewasappropriatelyexecuted.Inaddition,thevalidityofthelicensee'sconclusions,inconsiderationoftheresultsreportedintheIPEEEsubmittal,wasassessed.Also,bounding-analysisandPRAresultspertainingtofrequenciesEnergyResearch,Inc.ERI/NRC95-504 Pr' ofoccurrenceofhazardsandestimatesofconditionalprobabilitiesoffailure,werecheckedforreasonableness.Reviewteamexperiencewasreliedupontoassessthevalidityofthelicensee'sevaluation.EnergyResearch,Inc.ERI/NRC95-504 2CONTRACTORREVIEWFINDINGS2.15gismzAsummaryofthelicensee'sseismicIPEEEprocesshasbeendescribedinSection1.2.Here,thelicensee'sseismicevaluationisexaminedindetail,anddiscussionisprovidedregardingsignificantobservationsencounteredinthepresentreview.2.1.1OverviewandRelevanceoftheSeismicIPEEEProcessa.SeismicReviewCaregoryandRevie-LevelEanhquake(RLE)St.LucieNuclearPlantislocatedinanareaoflowseismicity,ontheeasterncoastofpeninsularFlorida.EachofthetwoSt.Lucieunitsisatwo-loopCombustionEngineeringPWR.St.LucieUnit1wentintocommercialoperationduringDecember1976,andisintheseismicqualificationutilitygroup(SQUG)/USIA46program;St.LucieUnit2begancommercialoperationduringAugust1983,andisnotintheUSIAP6program.Thedesignbasisearthquake(DBE)peakgroundacceleration(PGA)forSt.LucieNuclearPlantisO.lg(horizontalandvertical)forthesafeshutdownearthquake(SSE).TheDBEspectralshapesaredifferentforthetwounits;Unit1wasdesignedforaHousnerspectralshape,andUnit2wasdesignedfora,RegulatoryGuide(R.G.)1.60spectralshape.CategoryIstructuresforbothunitsarefoundedonCategory-Ifill,underlainbycementedsandsandsandylimestones.Duetothelowseismichazardatthesite,St.Luciehasbeendesignatedasareduced-scopeplantinNUREG-1407.TheRLEisequivalenttotheSSE.b.SeismicIPEEEProcessThelicenseehasimplementedasite-specificseismicadequacyevaluationprogrambasedonamethodologyithascompiledforexecutingitsUSIA-46resolutionprogramatTurkeyPointUnits3and4,andatSt.LucieUnit1.(TheNRChasdetermined,pendingapprcpriatefollow-upactionbythelicensee,thatUSIAMhasbeenadequatelyresolvedforSt.Lucie-1andTurkeyPoint[6,7].)ThelicenseeclaimsthatitsprocessconformswiththeOptionalMethodologyofParagraph3.3inNUREG-1407.However,theprogramwasneveractuallyapprovedbytheNRC.c.ReviewFindingsTheIPEEEprocessisnotfullyconsistentwiththerecommendedguidelinesofNUREG-1407forSt.Lucie.FPL'sseismicprogramsforSt.LucieUnits1and2addressonlyaportionoftheseismicIPEEEelements/concernsforareduced-scopeplant.TheIPEEEsubmittalforSt.LucieUnit1isessentiallyidenticaltotheUSIAMsubmittal.Hence,theconcerns/findingsdocumentedbytheNRCforUSIA<6areapplicabletoanumberoftheaspectsoftheseismicIPEEE.Nonetheless,thefactthatFPL'sseismicadequacyevaluationprogramdepartsfromacompletereduced-scopeassessmentisviewedtobeasignificantweakness.TheoverallseismicIPEEEmethodologyEnergyResearch,Inc.ERI/NRC95-504 jr 4employedbyFPLhasonlyalimitedpotentialtoachieveIPEEEobjectives,andtoassesssevereaccidentvulnerabilitiesatSt.LucieNuclearPlant.2.1.2SuccessPathsandComponentListSuccesswasdefined,forpurposesofidentifyingasuccesspath,astheabilitytoachieveandmaintainahotshutdownconditionfor8hours.Lossofoffsitepowerwasassumedinchoosingthesuccesspath.Inaddition,adesignbasisearthquakewasassumednottotripthereactor.Theprimaryelementsofthechosensuccesspathinclude:supervisoryandcontrolfunctionrequirements,requirementsofdecayheatremovalviatheAFWsystem,emergencyelectricalpowerrequirements,chemicalandvolumecontrolrequirements,andequipmentcooling(ultimateheatsink)requirementsviatheCCWandICWsystems.Thesubmittalstatesthatallactiveequipmentpertainingtothesuccesspathwereidentifiedindevelopingasafeshutdownequipmentlist(SSEL).Somepassivecomponents,suchastanksandheatexchangers,werealsoincludedintheSSEL.Asignificantnumberofcomponents(e.g.,AFWpumps)wereremovedfromtheSSELbecausetheyhadbeenpreviouslyreviewedforseismicadequacyinanotherprogram.(Similarly,potentialinteractionconcernsthatinvolvedblockwallswereconsideredresolvedifthewallswerepreviouslyaddressedunderIE80-11[17]).TheresultingSSELdefinesthesetofcomponentsconsideredinplantwalkdowns.FPL'sseismicadequacyevaluationdoesnotclearlyidentifythechosensuccesspath,nordoesitpresentasuccesspathlogicdiagram.OnlyonesuccesspathwasinvolvedindevelopingtheSSEL,andonlyalimitedsetofcomponentswereidentifiedforeachmajorsuccess-pathfunction.Thestudydidnotexplicitlyaddressasmall-breaklossofcoolantaccident(LOCA)inthedevelopmentofthesuccesspathandSSEL.TheSSELconsidersactivecomponentsandapartiallistofpassivecomponents.ThesuccesscriterionusedintheFPLstudyistheabilitytoachieveandmaintainhotshutdownforatimeperiodofonly8hours,ratherthantherecommended72hours.However,inresponsetoRAIsraisedbytheNRCinitsUSIAMreviewprocess,FPLindicatedthattheplanthasmultiple(albeitnon-seismicallyqualified)watersourcesthatcouldprovidecoolingfor72hours.Inaddition,FPLindicatedthattheplanthasthe(seismicallyqualified)capabilityo~indefinitelylongfeed-and-bleedcooling.Thus,theequipmentlistdevelopedintheFPLstudyappearstobeconsiderablylimited,andconsidersonlyasubsetofcomponentsthatshouldbeevaluatedinareduced-scopeassessment.2.1.3Non-SeismicFailuresandHumanActionsa.OverallApproach44TheseismicadequacystudiesnotethatareviewofoperatingprocedureswasperformedforSt.LucieNuclearPlanttoverifytheequipmentlistandtoidentifyanyequipmentwhichmightberequiredtobringthereactorfrom100%powertohotshutdown.Additionally,operatingprocedurestoshutdownthereactor,takethereactortohotshutdown,torespondtoreactortrip,andtorespondtolos-of'offsitepowerwerereviewed.Nomentionismadeofspecificnon-seismicfailuresorhumanactionsthatmightlimitthecapabilityofthechosensuccesspath.EnergyResearch,Inc.ERI/NRC95-504 ly b.ScreeningCrireriaRandomandoperatorfailurerateswerenotreported;noscreeningcriteriawereappliedwithrespecttonon-seismicfailuresandhumanactions.c.ReviewFindingsAccordingtoNUREG-1407,candidatesuccesspathsshouldbescreenedtoinsurethatimpactsofnon-seismicfailuresandhumanactionswillnotbecontrollingfactorsinhibitingthelikelihoodofsuccessfulhotshutdown.FPL'sseismicevaluationhasnotidentifiedthespecificrandomfailuresandhumanactionswhichmightcompromisetheintegrityofthechosensuccesspath.Hence,thelicensee'sstudyisinadequateinitstreatmentofnon-seismicfailuresandhumanactions,whichisthusviewedtobeaweaknessofthestudy.2.1.4SeismicInputSeismicinputsforevaluationstudiesofSt.Lucie,Units1and2,weredefinedbySSEspectraandotherplant-specificdesign-basiscommitmentsinthefinalsafetyanalysisreport(FSAR).ForSt.Lucie-l,theSSEisidentifiedbyaHousnerspectralshapeanchoredtoaPGAlevelofO.lg.ForSt.Lucie-2,theSSEisaR.G.1.60[18)shape'anchoredtothesamePGAvalue.NUREG-1407indicatesthattheSSEgroundresponsespectrashouldbeusedtodefineinputtostructures,andforcomputingin-structureresponsespectra.FPL'sseismicadequacyevaluationprogramusestheSSEspectrumorFSARin-structurespectraasthebasisfordefiningseismicinputforcomponents.Hence,thelicensee'sdefinitionanduseofseismicinputisconsistentwiththeguidelinesofNUREG-1407forareduced-scopeplant.2.1.5StructuralResponsesandComponentDemandsSt.LucieUnit1hadexistingfloorresponsespectracurvesforthecontainmentstructureandtheauxiliarybuilding;St.LucieUnit2hadexistingfloor'esponsespectracurvesforallsafety-relatedbuildingsandstructures.Buildingmodelsusedtogeneratefloorresponsespectraincludedtranslationalandrotationalspringstoaccountforsoil-structureinteractioneffects.ThefloorresponsespectrawereusedtodefinedemandsformanyoftheSSELcomponents.Forcomponentswhereexistingfloorresponsespectrawerenotavailableforassessingdemands(whichwasthecaseonlyforSt.LucieUnit1),estimatesofcomponentdemandsweremadebaseddirectlyontheSSEspectrum.Theapproachforassessingsuchdemands(forequipmentlessthan40feetabovegrade)wasto:(a)takethepeakspectralaccelerationfromthe5%dampedSSEspectrum,(b)multiplythispeakvalueby1.5toaccountforbuildingamplification,and(c)multiplyagainbyafactorof1.25forconservatism.NUREG-1407indicatesthatexistingFSARin-structurespectra,basedonSSEinputandFSARlicensingcriteria,maybeusedforevaluatingcomponentdemands.IntheFPLseismicadequacystudies,FSARin-structurespectrawereused,whenavailable,toestablishequipmentdemands.Whenin-structurespectrawerenotavailable(St.LucieUnit1only),agenerallyconservativeprocedurebasedonscalingthepeakSSEspectralaccelerationwasusedtodefinecomponentdemands.Thelicensee'sdevelopmentofcomponentdemandsthusappearsconsistent,toasignificantdegree,withtheguidelinesofNUREG-1407EnergyResearch,Inc.10ERI/NRC95-504

'r0 forareduced-scopeplant.Additionally,theNRChasacceptedthisaspectofthelicensee'sanalysisforUSIA46resolution[7].2.1.6ScreeningCriteriaScreeningfortheSt.Lucieseismicevaluationstudieshasnotfollowedtheformalproceduresdescribedinthegenericimplementationprocedure(GIP)[19]orinElectricPowerResearchInstitute(EPRI)NP-6041[20],asrecommendedinNUREG-1407.Rather,theproceduresdescribedinReference[21],theSeniorSeismicReviewandAdvisoryPanel(SSRAP)document,havegenerallybeenimplemented.WhetherGIP,EPRINP-6041,orotherproceduresareusedforscreening,screeningcaveatsmustbeobserved,anchoragecapacitychecksmustbeperformed,andspatialinteractionissuesmustbeappropriatelyassessed.Additionally,inanyscreeningprocedure,SRTjudgmentplaysthemajorroleincomponentevaluations.FPL'sscreeningapproachhasbeenbasedprimarilyonSRTjudgment,oncomparisonsofestimatedanchoragecapacityversusSSE-consistentdemand,andoninsightsderivedbytheSSRAP.Althoughthelicensee'sapproachtoscreeningdoesnotconformpreciselytotherecommendationsofNUREG-1407forareduced-scopeplant,itisjudgedtobeareasonableprocessthatsubstantiallyachievesthesignificantintentofcomponentscreening.2.1.7PlantWalkdownProcessa.Preparatory8'orkApre-walkdownoftheplantwasperformedtohelptheseismicreviewteam(SRT)membersidentifywhatinformationandassistancewouldbeneededduringtheseismiccapabilitywalkdown.FPLengineersgatheredgenericandequipment-specificdocumentationasdeemednecessarybytheSRT.Inaddition,FPLstafffamiliarwithplantsystemsdevelopedthelistofequipmenttobewalkeddown.b.SeismicCapabilityWalkdownPlantwalkdownswereconductedbyanSRTconsistingofthreehighlyexperiencedwalkdownexperts.Theseismicadequacyevaluationstudieshavereliedheavilyonthejudgmentoftheseengineers.Duringthewalkdown,FPLprovidedstaffengineerstohelpsupporttheSRTmembers,primarilyinobtainingadditionalplantinformationthatwasneededonacase-by-casebasis.Theactualdurationofseismicwalkdownsisnotmentionedinthedocumentation.Fourconsiderationswereaddressedintheplantwalkdownscreeningeffort:(1)equipmentseismiccapacityversusdemand,(2)constructionadequacyofequipment,(3)anchorageadequacy,and(4)seismicspatialinteractionconcerns.Thewalkdownalsomadenoteofconcernsrelatedto:(5)generalseismic"housekeeping"issues.Eachoftheseaspects.ofplantwalkdownsandcomponentscreeningisdescribedbrieflybelow.-Thisscreeningitempertainstoidentificationofseismicadequacyproblemsthatcouldbeinherenttospecifictypesofunqualifiedseismicequipment.Theseencompassthetypesofproblemsthatwouldbefoundinaqualificationtest,EnergyResearch,Inc.ERI/NRC95-504 including:functionalproblems,internallyfragileelements,andinadequateoverallstructuralresistanceofacabinet.TheSt.LucieseismicadequacyevaluationstreatedthisiteminagenericwaybasedonfindingsoftheSSRAP,asdocumentedinReference[21].Itwasdemonstratedintheevaluationstudiesthat(forusewithrespecttoequipmenthavinganaturalfrequencygreaterthan8Hzandlocatedlessthan40feetabovegrade)theSSRAPboundingspectrumenvelopesplantSSEspectraovertheentirefrequencyrange.Itwasalsodemonstratedthat(forusewithrespecttoequipmenthavinganaturalfrequencylessthan8Hzorlocatedmorethan40feetabovegrade)theSSRAPboundingspectrummultipliedby1.5envelopedplantfloorresponsespectra.Sincetheboundingspectrumrepresentsanexperience-basedseismicruggednessthresholdforunqualifiednuclearpowerplantequipment,theFPLstudyconcludesthatseismiccapacityversusdemandwasjudgedacceptableforallplantcomponents.Theplantwalkdowns,therefore,didnotgivemuchattentiontothisscreeningitem,onacomponent-by-componentbasis.-Thisscreeningitempertainstoidentificationofseismicadequacyproblemsthatcouldbeattributedtotheconfigurationormannerofconstruction/installationoftheequipmentattheplant.Generallyspeaking,theas-builtconfigurationofequipmentcanbeconsideredadequate,providedthatcertaincaveatshavebeenconsideredandsatisfied.FPLreasonedthat,duetolowseismicityatFPLplantsites,specificcaveatsdidnotneedtobeaddressedforeachtypeofequipment.TheseismicevaluationstudyfurthernotedthatSRTmembersareexpertsintheareaofseismicadequacyofequipment,andthattheynotedanyequipment-specificdetailsthattheyfeltwereseismicallyvulnerable.I'lIIIIIIII'Ithatareduetonon-existentorweakanchorage.Theconstructedanchorageconfigurationcanbeconsideredasacaveattobeconsideredintheevaluationofallcomponents.Itisaspecialcaveat,however,becauseitstreatmentusuallyrequiresmorethanjustavisualinspection;theexpecteddemandontheanchorageandanumericalestimateofanchoragecapacityareoftenneededtosatisfyanchoragecaveats.Intheseismicadequacyevaluations,SRTjudgmentwasusedtoscreenout"obviouslyrugged"anchorages.Otherwise,anumericalestimateofseismicadequacyofanchoragecomponentswasobtainedandcomparedagainstcomponentanchoragedemand.Anyproblemsnotedwithanchoragecapacityweredesignatedaspotentialoutlierstoberesolved.4.-Thisscreeningitempertainstotheidentificationofphysicaleffectsthatcouldindependentlycompromisetheperformanceofanotherwisewell-installedseismicallyadequatecomponent.Suchphysicaleffectsinclude:objectsimpactingequipmentinanymanner,conduitpull-outduetoinadequateflexibilityoflinesattachedtoequipment,blockwallcollapses,etc.Duringthewalkdowns,SRTmemberslookedfor,andmadenoteof(onwalkdownworksheets),anypotentialseismicspatialinteractionconcerns;identifiedconcernsweredesignatedaspotentialoutliers.EnergyResearch,Inc.12ERI/NRC95-504

~gPI/

5,-Thiswalkdownitempertainstosituationsthat,althoughnotleadingtofailureofanimportantsafety-relatedcomponent,canexacerbateproblemsand/orinhibitoperatoreffectivenessfollowinganearthquake.AnyinstancesofpoorseismichousekeepingobservedbySRTmemberswerenotedandreportedtoFPL.Amongthesefivewalkdownitems,primaryconsiderationwasgiventoassessinganchorageadequacyandtoidentifyingseismicspatialinteractions.c.ReviewFindingsNUREG-1407recommendstheuseofGIPorEPRINP-6041walkdownprocedures.TheSt.Luciewalkdownhasimplementedproceduressubstantiallysimilartothese,perhapsallowingforsomewhatgreaterlatitudeintheuseofexpertjudgment.DueinlargeparttotheexceptionalqualificationsoftheSRTmembers,andtheNRC'sacceptanceoftheseismicwalkdownforUSIA<6resolution,thelicensee'swalkdownprocessis'consideredtobeadequateinidentifyingoutliersamongthosecomponentsthathavebeenincludedinthescopeofwalkdowns.2.1.8EvaluationofOutliersa.OverallApproachTheseismicadequacyevaluationsdonotmakeacleardistinctionbetween"outlier"and"potentialoutlier."AllitemsnotscreenedoutbytheSRTwereaddressedinsomemannerbyFPL.Forpotentialanchorageoutliers(i.e.,thoseanchorageconcernsscreenedinbytheSRTduringplantwalkdowns),more-detailedcalculationswereperformedtobetterdetermineseismicadequacy.Anycomponenthavinginadequate/lowanchoragecapacitywasidentifiedasanoutlierrequiringresolutionbyFPL.b.HighConjfdenceofLowProbabiliryofFailure(HCLPF)CalcularionsForSt.LucieUnit2,HCLPFcalculationswereperformedformanylarge,flat-bottomtanks.NoHCLPFcalcu]ationswereperformedforblockwallsidentifiedtobeapotentialinteractionproblem.(TheseismicadequacyevaluationsrelyonearlierIE80-11calculations.)c.ReviewFindingsForsomecomponentsthatwerescreened-inatSt.LucieNuclearPlant,capacitycalculationswereperformedtodemonstratewhetherornotthecomponentmettheFSARdemand(ortheconservativeapproximationtotheFSARdemand).Forcomponentsidentifiedasfinaloutliers,however,theoutlierassessmentwasoftenreadilymade(withoutcalculation)duetoanobviouslydeficientcondition(e.g.,sealweldononesideof480VMotorControlCenter(MCC)1A6,missingweldsonMCCportionof480VLoadCenter1A3).Foreachfinaloutliernoted,FPLproposedacorrectivemeasureandsubmittednon-conformanceresolutiondocumentation.ERI/NRC95-504Thelicensee'swalkdownprocessisjudgedtobeadequateinidentifyingoutliersamongthose(limitedsetof)componentsthathavebeenincludedinthescopeofwalkdowns.EnergyResearch,Inc.13

2.1.9RelayChatterEvaluationNUREG-1407indicatesthatcompletionoftheUSIA46reviewrequirementsforrelaychatterevaluationwillsatisfytheIPEEEintentforreduced-scopeplantsthatarealsoUSIA-46plants.Forreduced-scopeplantsthatarenotalsoUSIA-46plants,norelaychatterevaluationisnecessary.Thelicensee'sIPEEEsubmittaldoesnotmentionarelaychatterevaluationforSt.Lucie-1~However,duringNRC'sUSIA@6reviewforTurkeyPointandSt.Lucie-l,itwasrevealedthatFPLhadassessedbadactorrelays,verifiedmountingsofrelays,anddemonstratedthattherewerenodeleteriouseffectsofchatterofbadactorrelays.TheNRCacceptedthelicensee'srelayevaluationforUSIA-46resolution,andhence,theNUREG-1407recommendationfortheseismicIPEEEissatisfiedforSt.Lucie-1.NUREG-1407doesnotrequestarelayevaluationforSt.Lucie-2,anon-USIA-46plant.2.1.10SoilFailureAnalysisNUREG-1407statesthatnoevaluationofsoilfailuresisrequiredforareduced-scopeplant.Correspondingly,thelicenseehasnotperformedsuchananalysis.2.1.11ContainmentPerformanceAnalysisForreduced-scopeplants,NUREG-1407requeststhatperformanceofcontainmentandcontainmentsystemsshouldbeaddressed.Componentsnecessarytoachievesuccessfulaccidentmitigationneedtobeincludedinthescopeofseismicwalkdownsandoutlierevaluation.FPLdidnotincludethecontainmentstructuresorcontainmentsystemsinitsseismicadequacyevaluationsofSt.Lucie,Units1and2.Hence,thelicensee'sseismicadequacystudiesofSt.LucieUnitIandSt.LucieUnit2arenotresponsivetotheNUREG-1407requestforacontainmentperformanceanalysis.2.1.12Seismic-FireInteractionandSeismicallyInducedFloodEvaluationsa.EvaluarionofSeismic-FireInreracrionsSection4.8oftheIPEEEsubmittalreportdiscussesseismic-fireinteractions.Thetopicofseismic-fireinteractionsisoneelementoftheSandiafireriskscopingstudy(FRSS)issues.TheIPEEEsubmittalstatesthatallSandiaFRSSissuesaremorethanadequatelycoveredthroughtheSt.LucieFireProtectionProgram.Intermsofdetailsoftheseismic-fireevaluation,however,thesubmittalindicatesonlythat:"Essentially,theII/Icriteriawasappliedtofiresystemswhosefailurecouldaffectoperationofsafety-relatedsystems."Section2.2.12providesadditioncommentsonFPL'sseismic-fireevaluationforSt.Lucie.Nospecificdiscussionsofseismicallyinducedfires,ofseismicinadvertentactuationoffiresuppressionsystems,orofseismicallyinducedfailureoffiresuppressionsystemswereprovidedinthesubmittal.Seismic-FireWalkdownThesubmittaldoesnotindicatethataseismic-firewalkdownevaluationwasconducted.EnergyResearch,Inc.14ERI/NRC95-504 c.SeismicallyInducedFloodEvatuarionNodocumentationpertainingtoevaluationofseismicallyinducedfloodswassubmitted.d.ReviewFindingsTheSt.Lucieseismicadequacyevaluationhasnotfullyaddressedseismic-fireinteractionsorseismicallyinducedfloods.2.1.13TreatmentofUSIA45Areduced-scopeseismicassessmentshouldconsidertheseismiccapabilityofcomponentsnecessaryforsuccessfuldecayheatremoval,inresponsetoUSIA<5(DecayHeatRemovalRequirements).FPL'sseismicIPEEEsubmittalandseismicadequacyevaluationstudiesforSt.LuciedidnotdirectlydocumentfindingsforanyGenericIssues(GIs)lUSIsotherthanUSIA-46(forSt.LucieUnit1).Indirectly,USIAQSwasaddressedowingtothefactthatthesuccesspathneededtoaccomplishonemethodofdecayheatremoval(i.e.,viatheAFWsystem).However,theAFWpumpswereeliminatedfromtheseismicevaluation(becausetheyhadbeenpreviouslyexaminedforseismicadequacyelsewhere),andonlythecondensatestoragetank(CST)wasidentifiedasanecessarycomponentintheSSEL.Thelicensee'sseismicadequacystudydoesnotaddressameaningfulscopeofcomponentsrelatedtodecayheatremovalfunctions.Thisweaknessstemsfromthefact(notedinSection2.1.2ofthisTER)thattheSSELisonlypartiallycomplete.2.1~14PeerReviewProcessAnindependentexternalpeerreviewwasconductedbyDr.PaulSmithfortheseismicadequacyevaluationstudiesofSt.Lucie-1andSt.Lucie-2.Thispeerreviewidentifiedfiveadditionalseismicconcerns.FPLengineersalsoreviewedtheseismicstudies.Ameaningfulpeerreviewappearstohavebeenconductedforthelimited-scopeseismicevaluationstudiesofSt.Lucie-1andSt.Lucie-2.2.1.15SummaryEvaluationofKeyInsightsOnlyasubsetofcomponentsneededtoensuresuccessfulshutdownareconsideredinFPL'sequipmentlist,andhence,theseismicIPEEEprocesshasonlyalimitedpotentialtorevealvulnerabilitiesoroutliers.However,forthosecomponentsthathavebeenincludedinthescopeofFPL'sseismicadequacyevaluationstudies,theprocessimplementedforscreeningoutliers,andforaddressingtheirresolution,isconsideredtobeappropriateandadequate.FPL'sseismicadequacyevaluationstudyhasidentifiedanumberofoutliers(primarilyrelatingtoweakanchorage),andhasproposedrelevantmodificationstoenhancesafety.TheNRChasalreadyreviewedtheseoutliersandmodificationsforSt.LucieUnit1,aspartofUSIA-46resolution.Additionally,theNRChasconductedasiteinvestigationtoidentifyanyvulnerabilitiesthatmayrequirefurtherEnergyResearch,Inc.ERI/NRC95-504 analysis/treatment.Asaresult,FPLisperformingfollow-upactionstoimplementastricthousekeepingprogramatSt.Lucie.NooutliersreportedbythelicenseeappeartorequirefurtheranalysisforseismicIPEEEpurposes.However,additionaloutliersmayhavewellbeenfoundifthe'licenseehadexpandedthescopeofitsseismicadequacyevaluationstoaddressIPEEEwnlycomponentsandissues.Furthermore,thelicenseeelectednottoconductacontainmentperformanceanalysisatSt.LucieNuclearPlant.Thus,novulnerabilitiesaffectingcontainmentperformance,relatedtoseismicbehaviorofcontainmentsystems(e.g.,containmentcooling,containmentisolation,etc.),norpertainingtodirectseismicfailureofthecontainmentstructuresthemselves,wereidentified.TheSt.LucieNuclearPlantseismicadequacyevaluationstudiesarecapableoffindingonlyalimitedsetofseismic-related,severeaccidentvulnerabilities.2.2BzgAsummaryofthelicensee'sfireIPEEEprocesshasbeendescribedinSection1.2.Here,thelicensee'sfireevaluationisdescribedindetail,anddiscussionisprovidedregardingsignificantobservationsencou'nteredinthepresentreview.2.2.1OverviewandRelevanceoftheFireIPEEEProcessa.MethodSelectedforFireIPEEEThefireanalysiswasperformedperfire-inducedvulnerabilityevaluation(FIVE)methodology(Reference[22])intwophases.Thefirstphasewasascreeningstepbasedprimarilyoncontentsofafirezoneorarea.Inthesecondphase,thefrequencyofcoredamagefromafireinaspecificfirezonewasestimatedusingtheformulationsanddataprovidedintheFIVEmethodology.b.KeyAssumptionsUsedinPerformingFireIPEEETheIPEEEdoesnotprovideaseparatelistofassumptions.However,thepresentreviewhasidentifiedthefollowingassumptionswhichcouldhaveasignificantimpactonthefinalresults:Firebarriers/boundariesweretakentobeasgoodasrated.Nodiscussionsareprovidedastowhetheractivesystems(forexampleaselfclosing/normallyopenfiredoor)arepartoffirebarrierdefinition.Noconsiderationisgiventothepossibilityofopendoors,openducts,failureoffiredampers,etc.Thisresultsincross-zonefiresbeingjudgedtohavenegligiblerisk.Thermo-lagwasassumedtobeeffectiveforaselectgroupoffireareas.-.Allfiresinareascontainingsafeshutdownequipmentwereassumedtoleadtoreactortrip.Cont.inmentfireswerenotanalyzedexplicitly.Thisapproachwasbasedonthe'observationthatmostcontainmentfiresarerelatedtoRCPoilfires,whichhavebeenminimizedwiththeimprove-mentsintheoilcollectionsystem.EnergyResearch;Inc.16ERI/NRC95-504

~Allremotelyoperatedvalveswithhand-wheelswereassumedtobeavailableformanualoperation.c.StatusofAppendixRModijicanonsAppendixRmodificationswereassumedtobecompleted.d.NeworExistingPRATheIPEEEisanewstudy.ItusestheresultsofthealreadycompletedIPE[13]andPRA[23]forSt.Lucie.2.2.2ReviewofPlantInformationandWalkdownWalkdownTeamCompositionDifferenttypesofwalkdownshavebeenconducted.Thermo-lagevaluationwalkdownsprovidedinformationforthosecompartmentswherethisinsulatingmaterialwaspresent.Forotherareas,walkdownshavebeenconductedspecificallyforIPEEEfireanalysis.Inallcases,thewalkdownteamshaveincludedFPLengineers,fireprotectionspecialists,andpersonnelfromaconsultingfirm.Thefollowingareashavebeenreviewed:"A"and"B"safety-relatedswitchgear"A"and"B"electricalpenetrationroomsThecablespreadingroomsThe"A"cableloftareaReactorauxiliarybuildingbasementhallwayandhallareasHeating,ventilation,andairconditioning(HVAC)equipmentareaIntakecoolingpumpareasTurbinebuildingsandrelatedareasAuxiliaryfeedwaterpumpareasInverterroomBothunitshavebeenvisitedinthewalkdowns.References[1]and[14]donotprovideanydetailsonhowtheobservationsofthewalkdownhavebeenrecorded,andtheydonotprovidetheformatorasampleoftherecords.ThelicenseecitesotherinspectionsandthegeneralfamiliarityoftheIPEEEfireanalysisteamwiththeplantasadditionalbasisfortheIPEEEfireanalysis.However,itisnotclearwhethertheinformationgatheredfromtheseinspectionswasindeedusedintheIPEEEfireanalysis.b.SignificantWalkdownFindingsTheIPEEEdoesnotindicatethatthewalkdownteamdiscoveredanynewfirevulnerabilityfromtheplantvisit.FromtheIPEEE,itcanbeinferredthatthewalkdownwasusedmainlytoverifyequipmentandcablelocations,tomeasureareadimensions,andtoconfirmcombustibleloadings.c.Signi/cantPlantFeaturesThefollowingisalistofplantfeaturesthataredeemedtobeimportant:EnergyResearch,Inc.17ERI/NRC95-504

1.Themainfeedwaterpumpsareelectricmotordriven.2.Lossofthecomponentcoolingwater(CCW)systemcanleadtoreactorcoolantpump(RCP)sealfailure.3.ThesteamdrivenAFWpumpcanbeoperatedmanually.4.Thermo-lagisusedforseparationofredundanttrainsinsomeareasoftheplant.TheIPEEEfireanalysishastakencreditfortheeffectivenessofthismaterialonlyinaselectgroupoffireareas.2.2.3Fire-InducedInitiatingEventsa.WereIniriaringEventsOtherthanReactorTripConsidered?Reactortrip,lossofoffsitepower,andthepossibilityofaLOCAviareactorcoolantpumpsealfailurehavebeenconsideredintheIPEEE.b.WeretheInitt'aringEventsAnalyzedProperly?Fromtheinformationprovidedbythelicensee[1,14],itcanbeinferredthat,forlossofoffsitepowerandreactorcoolantpumpsealfailure,athoroughanalysishasbeenconducted.However,itisnotclearwhetherthepossibilityofhotshortfailuresincontrolcables,andinadvertentopeningoftheisolationvalvesofreactorcoolantsystem(RCS)highandlowpressureinterfaces,havebeenconsidered.Forexample,thepossibilityofapower-operatedreliefvalve(PORV)openinginadvertentlyhasnotbeenaddressedexplicitly.2.2.4ScreeningofFireZonesa.WasaProperScreeningMethodologyEmployed?Screeningwasproperlyconducted.ScreeningwasperformedperFIVEmethodology.AlistofallfirezonesisprovidedintheIPEEEsubmittal,alongwiththespecificscreeningcriteriaandassumptions.b.HavetheCableSpreadingRoomandControlRoomBeenScreenedOut?Thecablespreadingroomsandcontrolroomsofbothunitshavebeenincludedinadetailedanalysis,andhavenotbeenscreenedout.C.WereThereAnyFireZones/AreasthatHaveBeenImproperlyScreenedOut?TheIPEEEsubmittaldoesnotprovidesufficientinformationforproperevaluationofthescreeningeffort.Fromageneralstandpoint,andwhencomparedwithotherPWRplantsthatareincompliancewithAppendixRrequirements,theresultsseemtobereasonable.Thatis,thefirefrequenciesforeacharea,andfailureprobabilitiesoftheredundanttrains,appeartobereasonable.Manualactionsmayneedtobeundertakentoensureavailabilityofaredundanttrain.Therearenoindicationsastowhethertheeffectsofaspecificfireontheseactionshavebeenconsideredintheanalysis.EnergyResearch,Inc.18ERI/NRC95-504 2.2.5FireHazardAnalysisTheIPEEEhasusedthefireoccurrencedataprovidedinReference[23].Theexactapproach(i.e.,choiceofweightingfactors,ignitionsources,etc.)isnotspecified.Aplant-specificdatabasehasnotbeenused.PerReference[14],St.LucieNuclearPlanthasexperiencedalowernumberoffireeventsthanfortheaverageplant.Therefore,thisomissioncanbeconsideredas,conservative.2.2.6FireGrowthandPropagationFiregrowthandpropagationanalysiswasaccomplishedviatheformulationsprovidedinFIVE.,Thesubmittalprovidesaseparateappendixwheretheformulationsaredescribed.Themostrisk-significantareawherethesemethodshavebeenusedisthe"B"switchgearroom.Reference[14]providesabriefdescriptionofthisarea,butdoesnotprovideanyinformationregardingthesizeandexactlocationofthetransientfuelsthathavebeenconsidered.Thesubmittaldoesnotprovideanydetailsofhowthespecificfirepropagationscenariosweredeveloped,orhowtransientorotherfuelshavebeenpositionedwithinthefireareas.a.TreatmentofCross-ZoneFireSpreadandAssociatedMajorAssumprionsAspartofPhase-Iscreening,thefirecompartmentinteractionanalysis(FCIA)methodologyofFIVEhasbeenused.Compartmentshavebeencombinedtoformalargerfirezonethattakesintoaccountthepossibilityoffirespreadamongcompartments.However,possibilityoffirespreadthroughnormallyopenactivefirebarriers(e.g.,roll-updoorsandfiredampers)hasnotbeenaddressedexplicitly.GiventhediscussionsprovidedinReferences[1]and[14],itmaybeconcluded.that,sincethepossibilityoffirespreadhasbeenconsideredaspartofFCIA,thisphenomenonisofminimalrisksignificance.Thepotentialforfirebarrierfailureresultingfromfirefightingactivitieswasnotaddressed.Anexampleofsuchan'eventmayincludeafireinacompartmentwithtrain"A"equipmentandcables,whileaccesstothisroomisviatheadjacenttrain"B"compartment.b.AssumprionsAssociatedivithDetecrionandSuppressionForthemajorityofthecompartments,thespecificfiredetectionandsuppressioncharacteristicsoftheareawerenotaddressedandanalyzed.TheIPEEEsubmittalclaimsthat,exceptforthecontrolroom,nocreditwastakenformanualfiresuppression.Asimplemodelwasutilizedforsuppressionsystemfailure.Itwasassumedthatthereisaprobabilityof0.1forthefiredetection'andsuppressionsystemstofailtostopafirefromdamagingalargearea.Thisassumptionwasappliedtosixfireareas(bothunitscombined),ofwhichtwoareashavebeenscreenedout;Theotherfourareasconsistofthecablespreadingroomsandcontrolrooms.Thecompetingphenomenonbetweenfirespreadandfiredetection/suppressionwasnotmodeled.Also,therearenoindicationsforthesixfireareasastowhetheradetailedanalysisofthelocationsofthecritical(associatedwithsafeshutdown)cablesandequipmentwithinacompartmentwasconducted.Suchananalysisisimportant,sinceinsomecases,itispossibleforcriticalequipmentandcablestofail,regardlessofsuppressionsystemsuccessorfailure.'Energy'Research,Inc.19ERI/NRC95-504 c.TreatmentofSuppression-InducedDamagetoEquipment,ifApplicableInReference[I]thereisnodiscussion,foranyofthephasesoftheanalysis,ofsuppression-induceddamage(i.e.,damagetocablesandequipmentasaresultoftheactivationofthefiresuppressionsystemtoextinguishasmallfireinthearea).However,aspartofthediscussionsonthefireriskscopingstudyissuesraisedbySandia,itisexplainedthatallsafety-relatedareasareequippedwithpre-actiontypesprinklersystems,whichminimizesthepossibilityofwatersprayontocabinetsandmotors.Additionally,inReference[14[thisissueisfurtherdiscussedforfiresinthecontrolroom.Cablespreadingroomfiredamagecanbemitigatedbyusingthealternateshutdownpanel.Thus,itcanbeconcludedthattheadverseeffectsofwatersprayone1ectricalequipmentareofminimalrisksignificance.ComputerCodesUsed,ifApplicableThefirepropagation,detection,andsuppressionanalysishasbeenperformedusingtheformulationsprovidedinReference[23].TheformulationsaresummarizedintheappendixtotheIPEEEsubmittal.Thelicensee'sanalystshavedevelopedacomputerizedversionoftheformulations,whichhasbeenusedintheanalysis.2.2.7EvaluationofComponentFragilitiesandFailureModesa.DejinitionofFire-InducedFailuresThesubmittalprovidesashortdiscussiononthefire-inducedfailures.Thisdiscussionaddressestheavailabilityofremotelyoperatedvalvesthathaveahand-wheel.Nodiscussionisprovidedastowhetherornotconsiderationwasgiventoinadvertentoperationofequipmentandinstrumentation.b.MethodUsedtoDetermineComponentCapaciriesNocriteriaismentionedregardingsurvivalcapacitiesofcablesandelectricalequipment.GiventhattheFIVEmethodologywasused,AppendixRrequirementshavebeenmet,andthecablesareIEEE383qualified,thelicenseeisexpectedtohaveusedtheproperfailurecriteria.c.GenericFragiliriesThecablesareIEFE383qualified.Therefore,theoverallconclusionsregardingpotentialforfirespreadandfailureare,ingeneral,acceptable.d.Plant-SpecificFragiliriesPlant-specificf'ragilitieshavenotbeenused.e.TechniqueUsedtoTreatOperatorRecoveryAcrionsAsimplemodel(failureprobabilityof0.1)wasemployedforhumanrecoveryactionsinthecaseofacontrolroomfireoracab1espreadingroomfire.Thisapproachandprobabilityvaluehavebeencommonlyusedinotherfireriskstudies,andaredeemedtobesufficientlyconservativeprovidedtheplantEnergyResearch,Inc.20ERI/NRC95-504 employsawrittenprocedureforusingthealternateshutdownsystemandconductstrainingdrillsforthisprocedure.Forfireeventsoutsidethecontrolroomorcablespreadingroom,thehuman,failureprobabilitiesembeddedintheinternaleventsmodeloftheIPEhavebeenusedforconditionalcoredamageprobabilityestimation.Referencef14]providesadiscussionoftheoperatoractionsthatmayneedtobeundertakenfromoutsidethecontrolroom.Inallcases,itisshownthatthefireeventcannotaffecttheeffectivenessoftheoperatorfromreachingtherequiredplantarea,andfromconductingtheactionitself.2.2.8FireDetectionandSuppressionThepossibilityoffiredetectionandsuppressionhasbeentakenintoaccountforsixfireareas(bothunitscombined).AsmentionedinSection2.2.7above,asimplemodelwasused.Aprobabilityof0.1fordetectionandsuppressionfailurewasusedinthemajorityofthecases.Specificcompartmentconditionswerenotmodeledexplicitly.Thisapproachcouldbeoptimisticifthecriticalcablesandequipmentarelocatedwithinasmallpartoftheroom.Inotherwords,regardlessoffailureorsuccessoffiredetectionandsuppression,thecriticalsetofcablesandequipmentmaybesoclosetogether,thatincaseofafirewithinthatspecificarea,theequipmentandcableswouldberenderedfailedbythefirebeforethesuppressionsystemhasanopportunitytostopthedamage.2.2.9AnalysisofPlantSystemsandSequencesa.KeyAssumpnonsIncludingSuccessCriteriaandAssociatedBasesThesuccesscriteriaweredirectlytakenfromtheprobabilisticriskanalysis(PRA)oftheplant.b.EventTrees(FuncnonalorSystemic)TheIPEEEdoesnotprovideanydiscussionastothemodelingmethodsusedinthePRA.c.'ependencyMatrix,ifitIsDifferentfromthatforSeismicEventsNodependencymatrixhasbeenprovided.d.Plant-UniqueSystemDependenciesThesubmittaldoesnotidentifyanyplant-uniquesystemdependenciesofrelevancetofirerisk.e.SharedSystemsforMuln-UnitPlantTheSt.Lucietechnicalsupportcenterissharedbetweenthetwounits.Theeffectofthiscenterinrecoveringfromaspecificfireeventmaybesignificant.However,theoveralleffectonthefireriskanalysisresultsisgenerallyminimal.Thereisapossibilityoffeedingpowerfromoneunittotheother.Across-tiebreakerisavailabletoconnectthedieselgeneratorofoneunittotheotherunit.Thepossibilityofusingthisfeaturehasbeenincludedintherecoveryactionsofatleastsixfirescenarios.Reference[14]indicatesthatthisrecoveryEnergyResearch,Inc.21ERI/NRC95-504 l

actionistakenfromthecontrolroom,whichisisolatedfromtheplantareaswherethefiremaybepresent.Thisrecoveryactionhasnotbeenconsi'deredforthecontrolroomandcablespreadingroomfires.f.MostSigni/cantHumanAnionsTheIPEEEsubmittaldoesnotaddresshumanactionsseparately.Intwoareas,humanactionsarementioned:incontrollingtheplantfromafireinthecablespreadingroomorthecontrolroom;andinusingthecross-'tiebreakertopoweroneunitfromtheotherunit.2.2.10CoreDamageFrequencyEvaluationThelicenseehasprovidedtwoexamplesofcomputeroutputsfromCAFTAthatdemonstratetheconditionalcoredamagefrequencies.Thefirst100minimalcutsetsthatcontributetothecore'damagefrequencyarealsoshown.Itshouldbenotedthat,forthesetwoexamples,evenwiththefirst100cutsets,notmorethan80%oftheoverallfrequencyisaccountedfor.Noconcisesetofscenariosconstitutesthemajorityofthecoredamagefrequency.2.2.11AnalysisofContainmentPerformancea.SignijicantContainmentPerformanceInsightsContainmentfireswereconcludedtobeinsignificantforSt.Lucie.EventhoughSt.LuciehasexperiencedRCPoilfiresinthepast,thelicensee'sconclusionappearstobebasedonthefactthatalargefractionofcontainmentfireswereattributedtoreactorcoolantpumpoilleaks,andthattheplanthassincebeenequippedwithanoilcollectionsystem.ContainmentisolationfailurewasaddressedexplicitlyintheIPEEE.Itwasconcludedthattheprobabilityofisolationfailurefromafireislow.TheanalysisandtheconclusionsaresimilartothosereportedforotherPWRs,andtherefore,theyareconsideredreasonable.b.Plant-UniquePhenomenologyConsideredEventhoughitisnotdiscussedspecificallyinthesubmittal,itisinferredthatthesamephenomenologyhasbeenusedasthatintheIPEandPRA.FiresequencesandassociatedfailedequipmentwereanalyzedusingtheIPEcontainmenteventtrees.2.2.12TreatmentofFireRiskScopingStudyIssuesa.AssumpnonsUsedtoAddressFireRiskScopingStudyIssuesSeismicandfireinteractionwasaddressedthroughthefailureofthefiresuppressionsystemanditseffectsonsafetyequipment.Itisstatedthatfiresuppressiondesignincludesprovisionstominimizeinadvertentactuationfromaseismicevent.ThepossibilityoffireoccurrencefromseismicactivitywasnotaddressedinthefireanalysisportionoftheIPEEE.EnergyResearch,Inc.22ERI/NRC95-504 tg0t0~Il~

2.Firebarrierswereassumedtobequalified,pertheAppendixReffort.Specificprocedureshavebeencitedforinspectionandmaintenanceofthefiredoors,firedampers,firebarriers,andpenetrationsealassemblies.3.TheIPEEEsubmittalstatesthatallplantpersonnelwhohaveunescortedaccessmustundergofirewatchtraining.Inaddition,stricttraininganddrillsarerequiredforthefirebrigade.4.Regardingfiresuppressionsystemimpactonsafetysystems,itwasarguedthatallsprinklersystemsservingsafetyareasarepre-actiontype.Thisfeature,ifthesystemisequippedwithanalarm,wouldminimizethelikelihoodofinadvertentfirewaterimpactonsafetysystems.5.Controlsysteminteractionwasaddressedviatheuseofanalternateshutdownpanelandisolationswitches.Asimplemodelwasusedfortheoperatorsfailingtocontroltheplantfromthispanelincaseofacontrolroomorcablespreadingroomfire.6.SeveralprocedureshavebeencitedthataddressdifferentaspectsoffiresatSt.Lucie.Aspecificprocedureexists(althoughnodetailsareprovided)thataddressesfireemergencies.Anotherprocedureaddressescontrolroomevacuation.b.SignificantFindings1.Damagecausedbysuppressionsystemactuationisnotasignificantissue.2.Thefirebrigadeundergoessufficienttraining,andallpersonnelwhohaveunescortedaccessactasfire-watch.Thesuppressionsystems,insafety-relatedareas,canwithstandseismicevents,andtherefore,seismicallyinducedfailureoffireequipmentisnotaproblem.4.Inadvertentactuationoffiresuppressionisnotaproblembecausechargedsystemsarenotlocatedinsafety-criticalareas.5.Proceduresareavailablethataddressfire-relatedissues.6.Potentialadverseeffects'onplantequipmentbycombustionproductswerenotaddressed.7.Barrierfailureswerebasedonthecombustibleloadingofthearea.Noconsiderationwasgiventothemechanicalfailureofactivebarriers(e.g.,roll-updoors)..2.2.13USIA45IssueSt.LuciewasoneoftheplantsevaluatedbytheNRCfordecayheatremovaladequacy,inthecontextofUSIAA5.EnergyResearch,Inc.23ERI/NRC95-504 a.MethodsofRemovingDecayHearAuxiliaryfeedwater,mainfeedwater,andfeedandbleedcoolingarethemethodsconsideredforheatremovalduringandafterafireevent.b.AbilityofthePlanttoFeedandBleedSt.Luciehasthiscapability.c.CreditTakenforFeedandBleedCredithasbeentakenforfeedandbleedcapability.d.PresenceofThermo-LagSt.LuciecontainsThermo-lag.ThelicenseehastakencreditfortheeffectivenessofThermo-laginalimitednumberofareas.Thisissueisbeingevaluatedbythelicenseeatthistime.2.3HEQFxenh2.3.1HighWindsandTornadoest2.3.1.1GeneralMethodologyTheIPEEEsubmittal1conain[]tsanalysesforbothSt.LucieUnitsIand2.St.Lucie-2begancommercialoperationinAugust1983.AllofSt.Lucie-2'scomponentsandsystemsrequiredforsafeshutdownarelocatedin,orprotectedby,structuresthatmeetthelatestStandardReviewPlan(SRP).Thus,the"highwinds/tornado"-inducedrisktothisunitwasconsideredtobeinsignificantandwasqualitativelyscreenedout.St.Lucie-1begancommercialoperationinDecember1976.Thesubmittalreportsthatthe"highwinds/tornado"-inducedrisktothisunitwasconsideredtobeinsignificantonthebasisthatall"safety-relatedsystemsandcomponents"are:1.'ocatedwithintornadomissileprotectedstructures,2.Providedwithmissilebarriers,3.Havebeenshownnottobesusceptibletomissileimpactdamage,4.Havebeenshownnottoadverselyaffectsafetyifdamagedbyamissile,or5.Havealowprobabilityofmissiledamage.TheaboveconclusionswerereachedbyperformingthefirstfivestepsofthegeneralmethodologypresentedinSection1.1.3.EnergyResearch,Inc.24ERI/NRC95-504 2.3.1.2Plant-SpecificHazardDataandLicensingBasisThesiteisperiodicallya6'ectedbythepassageoftropicalcyclonesofvariousintensities,withthemonthsofSeptemberandOctoberhavingthehighestfrequencyofoccurrence.TornadoesandwaterspoutshavebeenobservedthroughouttheyearinthatpartofFlorida.Theparametersapplicabletothedesign-basistornadoare:tI~Externalwindforcesfromatornadofunnelwithahorizontalrotationalvelocityof300mphandahorizontaltranslationalvelocityof60mph,foratotalwindvelocityof360mph.~Adecreaseinatmosphericpressureofthree(3)psi.~Impactloadsfromatornadogeneratedmissile.Theparametersapplicabletothedesign-basistornado,usedforidentificationofsite-specificmeteorologicalconditions,areinagreementwiththerequirementsofR.G.1.76[24].ASCEPaperNo.3269[25]andANSIA58.1[26]wereusedtotransformthe,windvelocityintopressureloadingsonstructures.TheSt.Lucie-2missilespectrumisbasedonatornadozoneIsite,asidentifiedinR.G.1.76.Identificationofapplicableregionalandsite-specificmeteorologicalconditions,andhurricane/tornadowindloading,wasperformedusingthesameparametersandproceduresasusedforUnit2.TheUnit1design-basistornadomissilespectrumconsistsofa2"x4"x10'oodplanktravelingat360mph,anda4000poundautomobiletravelingat50mph.DuringtheUnit1licensingreview,theNRCstaffrequestedthattheUnit1capabilitytowithstandamoreextensivemissilespectrumbeevaluated.2.3.1.3SignificantChangesSinceIssuanceoftheOperatingLicenseThesubmittaldoesnotcataloganysignificantchangessincethetimetheplantoperatinglicense(OL)wasissued2.3.1.4SignificantFindingsandPlant-UniqueFeaturesNosignificantfindingsarecitedinthesubmittal.Asummaryofthewalkdownproceduresusedbythelicensee,andthequalificationsoftheteammembersperformingthewalkdown,arenotprovidedinthesubmittal.2.3.1.5HazardFrequencyWASH-1300[27];aDamesandMoore(DAM)study,aspresentedintheSt.Lucie-1FSAR,AppendixF;andNUREG/CR<710[28]arereferencedinthesubmittal.However,theNUREG/CRQ710valuesarethosewhichwereusedfortheevaluation.EnergyResearch,Inc.25ERI/NRC95-504 2.3.1.6BoundingAnalysisBoundinganalyseswereperformedforthedieseloilstoragetanks,andtheintakecoolingwater(ICW)systemandcomponentcoolingwater(CCW)systempipes.Nospecificassumptionshavebeenstated.However,thefollowingkeyimplicitassumptionsseemtohavebeenmade:1.Theconditionalmissileimpactprobabilityreported'inNUREG/CR4710isapplicabletothetargetsunderconsiderationinthestudy.2.Threatfromonlyonemissileiscredible.Thesubmittalreportsthatthefrequencyofdamage(tornadostrikefrequencyxmissileimpactprobability)foreachoneofthestructuresunderconsiderationislessthan10~/ry,andscreensoutthecontributionofthe"tornadoes/highwinds"hazardtotheplantoperationalriskatthisstageoftheanalysis.2.3.2ExternalFlooding2.3.2.1GeneralMethodologyThemethodologyconsistedofidentifyingthemajoreventsofconcern,assessingthepotentialthreatpresentedbythehazards,andevaluatingplantdefensesagainstthesehypotheticalevents.2.3.2.2Plant-SpecificHazardDataandLicensingBasisTheprobablemaximumhurricane(PMH)surgeandprobablemaximumprecipitation(PMP)wereconsideredasthemajoreventsofconcerntoSt.Lucie.ThehydrologicconditionsthatwilloptimizethepotentialerosionattheSt.Luciesitewereestablishedbyconductingastudyofhistoricalloopingandstalledhurricanesforthetimeperiodof1900to1973.Duringtheprobablemaximumflood,whichresults'fromthePMHsurge,thehighwaterlevelis17.2ftmeanlowwater(MLW).Theplantgradeisatelevation+18.5ft.MLW,andminimumentranceelevationtoallseismicCategory-Ibuildingsis+19.5ft.MLW.SeismicCategory-Istructuresandsafety-relatedcomponentsareprotectedfromtheeffectsofhighwaterlevelandwaverun-upthatareassociatedwithPMHconditions,by:1.Designingstructuresandcomponentstowithstandsucheffectswherefunctionallyrequired,2.Positioningofthestructuresandcomponentssuchthattheyarelocatedatsufficientgradetoprecludeinoperabilityduetoexternalflooding,and/or3.Housingthemwithinwaterproofstructures.Thedesign-basisprobablemaximumprecipitationfor24hours,usedintheanalysis,was24.1inches,overanareaof10squaremilesorless.EnergyResearch,Inc.26ERI/NRC95-504

~7Lw4 Theroofleadershavebeendesignedforarainfallintensityofsixinchesperhour.Shortperiodsofmoreintenserainfallresultinwaterrunningofftheedgesoftheroofs,withnoadverseeffectstosafety-relatedequipment.Nowaterbuild-upontheroofsinexcessof2"ispossible,exceptfortheshieldbuildingdome,whichissurroundedbya1'-6"highparapet.Thesubmittalstatesthatnoneoftheaboveconditionsadverselyaffectsthestructuresorsafety-relatedequipment.Thethreatofdamagefromtheprobablemaximumfloodonstreamsandriverswasdiscountedonthebasisthattherearenosuchwaterwayslocatedinclosevicinityoftheplant.Theriskfrompotentialdamfailureswasalsodiscounted,sincenodamsarelocatedwithinthehydrologicalinfluenceofHutchinsonIsland.Theriskpresentedbytheprobablemaximumtsunamifloodingwasdiscreditedonthebasisthat:(1)thereisnoevidencetoindicatetheexistenceofpotentialtsunamigeneratorsoffshoreinthesitearea;and(2)anypossibleeffectsatthesitelocationfromtsunamigeneratedfromfar-fielsourceswillbenegligiblecomparedtotheeffectofsurgescausedbythePMH.2.3.2.3SignificantChangesSinceIssuanceoftheOperatingLicenseThesubmittaldoesnotcataloganysignificantchangesthathaveoccurredsincethetimeofOLissuance.Thesubmittaldoesnotethatthelicenseeconsideredtheeffectsoflatest,increasedPMPcriteria,andconcludedthattherearenoconcernsassociatedwiththesitefloodinglevelsorroofpondingthatcouldaccompanyanincreasedPMP.2.3.2.4SignificantFindingsandPlant-UniqueFeaturesForUnit2,thedesign-basiseventsforfloodprotectionofsafety-relatedequipmentandfacilitiesmeettherequirementsofR.G.1.59,exceptthatthePMHpertinenttothesiteisthebasisforthecomputationoftheprobablemaximumsurge(PMS).TheR.G.1.59PMSwouldequal+16.7ft.MLW,whereasthesurgeassumedbytheSt.LucieFSARanalysisis+17.2ft.MLW.ThefloodprotectionrecommendationsofR.G.1.102werefollowed.TheSt.LucieUnit1safetyevaluationreport(SER)wasfinalizedbeforetheSRPwasissued.Thus,evaluationoftheconformanceofUnit1totheSRPcriteriawasmadebycomparingtheUnit1hazardanddesigntothatofUnit2.ThecomparisonindicatesthattheUnit1floodprotectionissimilartoUnit2,andthusmeetstheSRPcriteria.Thesubmittaldoesnotdiscussanywalkdownsthatwereperformedduringtheanalysis.2.3.2.5.HazardFrequencySincetheSt.LucieUnits1and2designsweredeterminedtomeettheR.G.1.59andSRPcriteria,thefloodinghazardwasqualitativelyscreenedout,andnohazardfrequencywasestimated.EnergyResearch,Inc.27ERI/NRC95-504

~4~gk 2.3.3TransportationandNearbyFacilityAccidents2.3.3.1GeneralMethodologyThemethodologyusedforevaluationoftransportationandnearbyfacilityaccidentsconsistsofthefollowingsteps:1.2.3.4.Reviewofplant-specifichazarddataandlicensingbases;Determinationofconformanceoftheplantrisksignificantstructurestothe1975SRPcriteria;Screeningofplantstructures'thatmeettheSRPcriteriaforaspecifichazard;andDeterminationofthehazardfrequencyforthosestructuresthatdonotmeettheSRPcriteria.2.3.3.2Plant-SpecificHazardDataandLicensi.Ba".sa.AirponsandAirwaysTherearenomajorairportswithin10milesoftheplant.Thenearestmajorairportwithcommercialfacilitiesis48milesfromtheplant.However,thereareseveralsmallerairportsinclosevicinitytotheplant.b.WarerivaysTheAtlanticOceanshippinglanesareabout10to15nauticalmileseastoftheplant,thus,noshiporbargeexplosioncanaffecttheplantstructures.BargespassingintheIntracoastalWaterwayaretheothersourceofpotentialhazardtotheplant.c.HighwaysThegoverningexplosiveand/orflammableeventwasjudgedtoariseonStateRouteA1A,whichpassesabout750feeteastofthedieseloilstoragetanks,duetoaliquefiedpropanetruckaccident.Thesubmittalstatesthattheprobabilityofhavingapotentialaccidentwhoseconsequencecanresultinaradionuclidereleaseinexcessof10CFR100guidelinesissignificantlylessthan10'/yr,basedonthecalculationsintheUnit2FSAR.TheresultsintheFSARarereportedtohavebeenvalidatedbasedondiscussionwithlocalauthoritiesandadrive-throughofthearea.However,sincethereportofthediscussionsandthedrive-throughobservationsarenotdocumentedinthesubmittal,theirconclusionscouldnotbeevaluatedforthisTER.d.RailroadsThenearestrailroadis2mileswestoftheplant.Thisdistancewasconsideredtobesufficienttoprecludeadverseeffectstotheplantfromaccidentalexplosionsontherailroad.Chlorineisthemostlikelyhazardousmaterialtobeshippedontherailcars.ThesubmittalreferencestheUnit2FSARwhichprovidesanevaluationdemonstratingthattheprobabilityofachlorinereleaseadverselyaffectingtheplantislessthan10~peryear.TheresultsintheFSARanalysisarereportedtobevalidbasedondiscussionwithlocalauthoritiesandadrive-throughofthearea.However,sincethereportofthediscussionsandEnergyResearch,Inc.28ERI/NRC95-504 thedrive-throughobservationsarenotdocumentedinthesubmittal,theirconclusionscouldnotbeevaluatedforthisTER.e.ToxicChemicalEventsChemicalsthatarenon-volatileorliquids,orthatspontaneouslycombustinair,werenotconsideredtoposeathreattocontrolroomhabitability.Also,chemicalsforwhichtheirpotentialforignitionconstitutesagreaterhazardthantheirtoxicity,wereeliminatedfromconsideration.Thethreattocontrolroomhabitabilityfromthetoxicchemicalswhichwerenoteliminatedonthebasisofthecriteriastatedabove,wereeliminatedbyadetailedassessmentoftheiratmospherictransportandpotentialforinfiltratingintothecontrolroom.Ammoniumhydroxide,whichisstoredonsite;carbondioxide;andchlorine,whichistheprincipaltoxicsubstancetransportedbytheFloridaEastCoastRailway(FECR),arethemajorchemicalsforwhichtheirpotentialimpactoncontrolroomhabitabilitywasanalyzedindetail.Thethreatsposedbyammoniumhydroxideandcarbondioxideweredismissedonthebasisthattheconcentrationofthesechemicalsinsidethecontrolroomremainswellbelowthetoxicitylimit.ThethreatposedbythereleaseofcMorineduetoarailroadaccidentwasdismissedbasedonthefrequencyofthedesign-basisevent.f.Indus(rialFaciliriesTherearenomilitarybases,"missileinstallations,chemicalplants,hazardousmaterialstorageareasordrillingoperationswithin10milesofSt.Lucie.Therearenopipelineswithin5milesoftheplant.2.3.3.3SignificantChangesSinceIssuanceoftheOperatingLicenseThesubmittaldoesnotcataloganysignificantchangessincethetimeofOLissuance.2.3.3.4a.AirwaysSignificantFindingsandPlant-UniqueFeaturesTheestimatednumberofoperationsperyearfromoneofthelocalairportswasfoundtobegreaterthantheSRPscreeningvalueof144,000.b.WaterwaysConsideringthemaximumsizeofbargespassingtheplantsite;Equation1ofR.G.1.91,"EvaluationofExplosionsPostulatedtoOccuronTransportationRoutesNearNuclearPowerPlants"[29];andthedistancebetweenanysafety-relatedstructuresandthenearestIntracoastalWaterwayshippingchannel,theriskofdamagefromabargeexplosionwasdismissed.EnergyResearch,Inc.29ERI/NRC95-504

~g 2.3.3.5HazardFrequencya.AirwaysSincetheestimatednumberofoperationsperyearforalocalairportwasfoundtobegreaterthantheSRPscreeningvalue,theSandiaNationalLaboratories(SNL)[30]andSRPmethodswereusedtoshowthattheaircraftcrashfrequencyisbelow10~/yr.b.ToxI'cChemicalEventsTheaccidentalreleaseoftheentirecontentsofchlorinefromatankcarwasassumedtobeaninitiatingeventforadesign-basisaccident.Thefrequencyofsuchaneventwascalculatedaccordingtothefollowingequation:wherePi=annualprobabilityofdesign-basiseventunderatmosphericstabilityClassI,'nvolvingthei-thchemical;P-probabilityofadesignbasisaccidentforamobilesourceperunitlengthoftravel;M,=D=jannualnumbersoftripsinvolvingthei-thchemical;annualprobabilityofanatmosphericstabilityclass;thelengthofroad,rail,orriverinsectorj;FJIwindfrequencyfromsectorjtooutsideairintakeofthecontrolroomforstabilityClass1;andnumberofwinddirectionsectors.Usingtheaboveformula,theoverallprobabilityofaneventthatmayaffectcontrolroomhabitabilitywasdeterminedtobe1.4x10'/yr.Therefore,theSt.LucieUnit2designwasdeterminedtoeithermeettheSRPcriteria,orhavealowhazardfrequency.DuetotheproximityofUnits1and2,thehazardanalysisforUnit2was.judgedtobeapplicableforUnit1.2.3.4LightningandOthersThesubmittalpresentsadiscussionoftheSt.Lucielightningprotectionsystem.BasedonareviewoftheSt.LucieFSARs,theplant'soperatinghistory,andNUREG/CR-4710findings,thesubmittalconcludesEnergyResearch,Inc.'0ERI/NRC95-504 I

thatthereisnouniqueplantvulnerabilitytolightningatSt.Lucie,andthattheimpactoflightningonplantriskisboundedbytheinternaleventsanalysis.2.42.4.1GSI-147,"Fire-InducedAlternateShutdown/ControlPanelInteraction"GSI-147addressesthescenariooffireoccurringinaplant(e.g.,inthecontrolroom),andconditionswhichcoulddevelopthatmaycreateanumberofpotentialcontrolsystemvulnerabilities.Controlsystemiinteractionscanimpactplantriskinthefollowingways:ElectricalindependenceofremoteshutdowncontrolsystemsLossofcontrolpowerbeforetransferTotallossofsystemfunctionSpuriousactuationofcomponentsAsindicatedintheresponsetoQuestionII-3inReference[14],forthepossibilityofoccurrenceoflossofoffsitepowerandreactorcoolantpumpsealfailurefromafire,"athoroughanalysishasbeenconducted.However,itisnotclearwhetherthisanalysisconsideredthepossibilityofhotshortfailuresincontrolcables,andinadvertentopeningoftheisolationvalvesofreactorcoolantsystemhighandlowpressureinterfaces.SincethesubmittalhasfollowedtheguidanceprovidedinFIVEconcerningcontrolsysteminteractions,allcircuitryassociatedwithremoteshutdownisassumedtohavebeenfoundtobeelectricallyindependentofthecontrolroom.2.4.2GSI-148,"SmokeControlandManualFireFightingEffectiveness"GSI-148addressestheeffectivenessofmanualfire-fightinginthepresenceofsmoke.Smokecanimpactplantriskinthefollowingways:~Byreducingmanualfire-fightingeffectivenessandcausingmisdirectedsuppressionefforts~Bydamagingordegradingelectronicequipment~Byhamperingtheoperator'sabilitytosafelyshutdowntheplant~ByinitiatingautomaticfireprotectionsystemsinareasawayfromthefireReference[31]identifiespossiblereductionofmanualfire-fightingeffectivenessandmisdirectedsuppressioneffortsasthecentralissueinGSI-148.Manualfire-fightingwasnotcreditedintheanalysis.Thus,theissueofmanualfire-fightingeffectivenessisnotaddressedinthisTER.2.4.3GSI-156,"SystematicEvaluationProgram(SEP)"Reference[31]providesthedescriptionofeachSEPissuestatedbelow,anddelineatesthescopeofinformationthatmaybereportedinanIPEEEsubmittalrelevanttoeachsuchissue.TheobjectiveofthissubsectionisonlytoidentifythelocationintheIPEEEsubmittalwhereinformationhavingpotentialrelevancetoGSI-156maybefound.EnergyResearch,Inc.31ERI/NRC95-504

SettlemenrofFoundarionsandBuriedEquipmentIEI:hbjifbiSEPiikfy.systemsandcomponentsareadequatelyprotectedagainstexcessivesettlement.Thescopeofthisissueincludesreviewofsubsurfacematerialsandfoundations,inordertoassessthepotentialstaticandseismicallyinducedsettlementofallsafety-relatedstructuresandburiedequipment.Excessivesettlementorcollapseoffoundationscouldresultinfailuresofstructures,interconnectingpiping,orcontrolsystems,suchthatthecapabilitytosafelyshutdowntheplantormitigatetheconsequencesofanaccidentcouldbecomprised.Thisissue,applicablemainlytosoilsites,involvestwospecificconcerns:~potentialimpactofstaticsettlementsoffoundationsandburiedequipmentwherethesoilmightnothavebeenproperlyprepared,andseismicallyinducedsettlementandpotentialsoilliquefactionfollowingapostulatedseismicevent.Sincestaticsettlementsarenotbelievedtobeaconcern,thefocusofthisissue(whenconsideringrelevantinformationinIPEEEs)shouldbeonseismicallyinducedsettlementsandsoilliquefaction.Itisanticipatedthatfull-scopeseismicIPEEEswilladdresstheseconcerns,followingtheguidanceinEPRINP-6041.St.Lucieisareduced-scopeplant,andCategoryIstructuresforbothunitsarefoundedonCategory-Ifill,underlaidbycementedsandsandsandylimestones.TheIPEEEsubmittalprovidesnodiscussionofthepotentialandeffectsforseismicallyinducedsettlements.orsoilliquefaction.InformationonsitegeologycanbefoundinSection2.2ofReference[5].DamIntegrt'tyandSiteFloodingt31:biifhi'ii0liifpfloodingandtoensureacoolingwatersupply.Thesafetyfunctionswouldnormallyincluderemainingstableunderallconditionsofreservoiroperation,controllingseepagetopreventexcessiveupliftingwaterpressuresorerosionofsoilmaterials,andprovidingsufficientfreeboardandoutletcapacitytopreventovertopping.Therefore,thefocusistoassurethatadequatesafetymarginsareavailableunderallloadingconditions,anduncontrolledreleasesofretainedwaterareprevented.Theconcernofsitefloodingresultingfromnon-seismicfailureofanupstreamdam(i.e.,causedbyhighwinds,flooding,andotherevents)isaddressedaspartoftheSEPissue"sitehydrologyandabilitytowithstandfloods."TheconcernsofsitefloodingresultingfromtheseismicfailureofanupstreamdamandlossoftheultimateheatsinkcausedbytheseismicallyinducedfailureofadownstreamdamshouldbeaddressedintheseismicportionoftheIPEEE.TheguidanceforperformingsuchevaluationsisprovidedinSection7ofEPRINP-6041.AsrequestedinNUREG-1407,thelicensee'sIPEEEsubmittalshouldprovidespecificinformationaddressingthisissue,ifapplicabletoitsplant.InformationincludedforresolutionofUSIA-45isalsoapplicabletothisconcern.TheSt.LucieIPEEEsubmittalstates(onpage79)thatnodamsarelocatedwithinthehydrologicalinfluenceofthesitelocationonHutchinsonIsland.EnergyResearch,Inc.32ERI/NRC95-504 IW'~

~~~~SiteHydrologyandAbilitytoWithstandFloodst3I.'biifUiii<<idifyhihdgihinordertoensurethecapabilityofsafety-relatedstructurestowithstandflooding,toensureadequatecoolingwatersupply,andtoensurein-serviceinspectionofwater-'controlstructures.Thisissueinvolvesassessingthefollowing:Hydrologicconditions-toassurethatplantdesignreflectsappropriatehydrologicconditions.Floodingpotentialandprotection-toassurethattheplantisadequatelyprotectedagainstfloods.JUltimateheatsink-toassureanappropriatesupplyofcoolingwaterduringnormalandemergencyshutdown.AsrequestedinNUREG-1407,thelicensee'sIPEEEsubmittalshouldprovideinformationaddressingtheseconcerns.Theconcernrelatedtoin-serviceinspectionofwater-controlstructures,acomplianceissue,isnotbeingcoveredin.theIPEEE.TheSt.LucieIPEEEsubmittal(Section5.2)hasincludedadiscussionofexternalfloods,includingeffectsofhurricanestormsurge(pages76to78)andprobablemaximumprecipitation(pages78,79,and82).IndustrialHazardsl3'I:hbifui'iU<<hiffstructures,systems,andcomponentswouldnotbejeopardizedduetoaccidenthazardsfromnearbyfacilities.Suchhazardsinclude:shockwavesfromnearbyexplosions,releasesofhazardousgasesorchemicalsresultinginfiresorexplosions,aircraftimpacts,andmissilesresultingfromnearbyexplosions.AsrequestedinNUREG-1407,thelicensee'sIPEEEsubmittalshouldprovideinformationaddressingthis'ssue.TheSt.LucieIPEEEsubmittal(Section5.3)includesthefollowinginformationofrelevancetothisissue:Section5.3.1ofthesubmittalidentifiesnearbytransportationroutes;Section5.3.2discussesnearbyindustrialfacilities;Section5.3.3discussesoffsiteandonsitesourcesofhazardousmaterialsorexplosives;Section5.3.4discusseshazarddataforairportsandairways;Section5.3.5discusseshazarddataforexplosions;andSection5.3.6discussespotentialtoxicchemicalevents.TornadoMissilesbi<<i'i"'i'Ip9>>(SEPplants)areadequatelyprotectedagainsttornadoes.Safety-relatedstructures,systems,andcomponentsneedtobeabletowithstandtheimpactofanappropriatepostulatedspectrumoftornado-generatedmissiles.AsrequestedinNUREG-1407,thelicensee'sIPEEEsubmittalshouldprovideinformationaddressingthisissue.TheSt.LucieIPEEE(Section5.1)hasinvolvedanevaluationoftornadoes,includingtornado-inducedmissiles.Detailedinformationandevaluationoftornado-inducedmissilesisprovidedinSection5.1.1.EnergyResearch,Inc.33ERI/NRC95-504 SevereWeatherEffectsonStructures[31]:Theobjectiveofthisissueistoassurethatsafety-relatedstructures,systems,andcomponentsaredesignedtofunctionunderallsevereweatherconditionstowhichtheymaybeexposed.Meteorologicalphenomenatobeconsideredinclude:straightwindloads,tornadoes,snowandiceloads,andotherphenomenajudgedtobesignificantforaparticularsite.AsrequestedinNUREG-1407,thelicensee'sIPEEEsubmittalshouldprovideinformationspecificallyaddressinghighwindsandfloods.Othersevereweatherconditions(i.e.,snowandiceloads)weredeterminedtohaveinsignificanteffectsonstructures(seeChapter2ofNUREG-1407).,TheSt.LucieIPEEEhasincludedevaluationsofhighwinds(hurricanes,andtornadoes)andexternalfloods.Section5.1ofthesubmittaldiscusseshurricanesandtornadoes,andSection5.2ofthesubmittaldiscussesexternalfloods.Section5.4ofthesubmittalincludesanevaluationforlightning.DesignCodes,Criteria,andLoadCombinarionst3f:Thbii"fhiii<<h<<ipfyshouldbedesigned,fabricated,erected,andtestedtoqualitystandardscommensuratewiththeirsafetyfunction.Allstructures,classifiedasSeismicCategoryI,arerequiredtowithstandtheappropriatedesignconditionswithoutimpairmentofstructuralintegrityortheperformanceofrequiredsafetyfunctions.Duetotheevolutionarynatureofdesigncodesandstandards,operatingplantsmayhavebeendesignedtocodesandcriteriawhichdifferfromthosecurrentlyusedforevaluatingnewplants.Therefore,thefocusofthisissueistoassurethatplantCategoryIstructureswillwithstandtheappropriatedesignconditions(i.e.,againstseismic,highwinds,andfloods)withoutimpairmentofstructuralintegrityortheperforma'nceofrequiredsafetyfunction.AspartoftheIPEEE,licenseesareexpectedtoperformanalysestoidentifypotentialsevereaccidentvulnerabilitiesassociatedwithexternalevents(i.e.,assesstheseismiccapacitiesoftheirplantseitherbyperformingseismicPRAsorSMAs).TheSt.LucieIPEEEhasincludedanevaluationofpotentialvulnerabilitiesassociatedwithexternalevents.Thesubmittaldoesnotsystematicallyidentifycodes,criteria,andloadcombinationsusedindesign.However,Sections2.5,and3.1to3.5ofReference[5]providesomeinformationrelatedtoseismicdesignofstructuresandequipment;Section51oftheIPEEEsubmittalprovidesinformationrelatedtowinddesignofstructures;Section5.2containssomeinformationrelatedtodesignconditionsforwithstandingfloods;andSection5.3ofthesubmittalprovidesinformationondesigncriteriarelatedtotransportationandnearbyfacilityaccidents,includingexplosions.SeismicDesignofStructures,Systems,andComponents[31]:TheobjectiveofthisSEPissueistoreviewandevaluatetheoriginalseismicdesignofsafety-relatedstructures,systems,andcomponents;toensurethecapabilityoftheplanttowithstandtheeffectsofaSafeShutdownEarthquake(SSE).TheSt.LucieIPEEEisbasedontheseismicadequacyevaluationperformedaspartofthelicensee'sresolutionofUSIA-46concerns(Reference[5]).Sections2.5and3ofReference[5]providesomeinformationrelatedtotheseismicdesignofstructuresandcomponents,andSection4ofReference[5]providesadescriptionoftheapproachandfindingsoftheseismicadequacyevaluation.EnergyResearch,Inc.34ERI/NRC95-504 ShutdownSystemsandElectricalInstrumentarionandControlFeaturest3I'.th'l'lh3Ifplreliableshutdownusingsafety-gradeequipment.Theissueonelectricalinstrumentationandcontrolistoassessthefunctionalcapabilitiesofelectricalinstrumentationandcontrolfeaturesofsystemsrequiredforsafeshutdown,includingsupportsystems.Thesesystemsshouldbedesigned,fabricated,installed,andtestedtoqualitystandards,andremainfunctionalfollowingexternalevents.InIPEEEs,licenseeswererequestedtoaddressUSIA45,"ShutdownDecayHeatRemoval(DHR)Requirements,"andtoidentifypotentialvulnerabilitiesassociatedwithDHRsystemsfollowingtheoccurrenceofexternalevents.TheresolutionofUSIA-45shouldaddressthesetwoissues.St.LucieNuclearPlanthadbeenusedasacasestudyplantbySandiaNationalLaboratoriesforprobabilisticevaluationofdecayheatremovaladequacy,inthecontextofUSIA<5.ThisissuewasaddressedaspartoftheIPEEE,ingeneral,andpertinentinformationisprovidedinSections4.9and5.1(page72)ofthesubmittal.Sections2.1.13and2.2.13ofthisTERsummarizereviewfindingsrelatedtoUSIA<5,respectively,forseismiceventsandfireevents.2.4.4GSI-172,"MultipleSystemResponsesProgram(MSRP)"Reference[31]providesthedescriptionofeachMSRPissuestatedbelow,anddelineatesthescopeofinformationthatmaybereportedinanIPEEEsubmittalrelevanttoeachsuchissue.TheobjectiveofthissubsectionisonlytoidentifythelocationintheIPEEEsubmittalwhereinformationhavingpotentialrelevancetoGSI-172maybefound.CommonCauseFailures(CCFs)RelatedtoHumanErrorst33:CCPIIIthII3fomissionthatcouldbeinitiatingevents,orcouldaffectredundantsafety-relatedtrainsneededtomitigatetheevents.OtherhumanerrorsthatcouldinitiateCCFsinclude:manufacturingerrorsincomponentsthataffectredundanttrains;andinstallation,maintenanceortestingerrorsthatarerepeatedonredundanttrains.InIPEEEs,licenseeswererequestedtoaddressonlythehumanerrorsinvolvingoperatorrecoveryactionsfollowingtheoccurrenceofexternalinitiatingevents.Averylimiteddiscussionofoperatorrecoveryactions,followingaseismicevent,isprovidedinSection4.4ofReference[5].Section4.6ofthesubmittalprovidessomediscussiononthetreatmentofhumanrecoveryactionsintheinternalfireanalysis.Non-Safety-RelatedControlSystem/Safety-RelatedProtecrionSystemDependenciesimpactonsafety-relatedprotectionsystems,asaresultofpotentialunrecognizeddependenciesbetweencontrolandprotectionsystems.Theconcernisthatplant-specificimplementationoftheregulationsregardingseparationandindependenceofcontrolandprotectionsystemsmaybeinadequate.Thelicensees'PEprocessshouldprovideaframeworkforsystematicevaluationofinterdependencebetweensafety-relatedandnon-safety-relatedsystems,andshouldidentifypotentialsourcesofvulnerabilities.Thedependenciesbetweensafety-relatedandnon-safety-relatedsystemsresultingfromexternalevents-i.e.,concernsrelatedtospatialandfunctionalinteractions-areaddressedaspartof"fire-inducedalternateEnergyResearch,Inc.35ERI/NRC95-504 shutdownandcontrolroompanelinteractions,"GSI-147,forfireevents,and"seismicallyinducedspatialandfunctionalinteractions"forseismicevents.InformationprovidedintheSt.LucieIPEEEsubmittalpertainingtoseismicallyinducedspatialandfunctionalinteractionsisidentifiedbelow(undertheheadingSeismicallyInducedSparialandFunctionalInteracrions),whereasinformationpertainingtofire-inducedalternateshutdownandcontrolpanelinteractionshasalreadybeenidentifiedinSection2.4.1ofthisTER.Heat/Smoke/WaterPropagarionEffectsPomFirest3I:difIpif*.NIIdtraincouldpotentiallybedamagedinoneoffollowingways:Heat,smoke,andwatermaypropagate(e.g.,throughHVACductsorelectricalconduit)intoasecondfirezone,anddamagearedundanttrainofequipment.Arandomfailure,notrelatedtothefire,coulddamagearedundanttrain.Multiplenon-safety-relatedcontrolsystemscouldbedamagedbythefire,andtheirfailurescouldaffectsafety-relatedprotectionequipmentforaredundanttraininasecondzone.Afirecancauseunintendedoperationofequipmentduetohotshorts,opencircuits,andshortstoground.Consequently,componentscouldbeenergizedorde-energized,valvescouldfailopenorclosed,pumpscouldcontinuetorunorfailtorun,andelectricalbreakerscouldfailopenorclosed.TheconcernofwaterpropagationeffectsresultingfromfireispartiallyaddressedinGI-57,"EffectsofFireProtection.SystemActuationonSafety-RelatedEquipment."TheconcernofsmokepropagationeffectsisaddressedinGSI-148.Theconcernofalternateshutdown/controlroominteractions(i.e.,hotshortsandotheritemsjustmentioned)isaddressedinGSI-147.InformationprovidedintheSt.LucieIPEEEsubmittalpertainingtoGSI-147andGSI-148hasalreadybeenidentifiedinSections2.4.1and2.4.2ofthisTER.Section4.8ofthesubmittalpresentssomelimitedinformationpertinenttothisissue.EjjectsofFireSuppressionSystemActuariononNon-Safety-RelatedandSafety-RelatedEquipment[31]:Firesuppressionsystemactuationeventscanhaveanadverseeffectonsafety-relatedcomponents,eitherthroughdirectcontactwithsuppressionagentsorthroughindirectinteractionwithnon-safetyrelatedcomponents.Items2and5ofSection4.8ofthesubmittalpresentsomelimitedinformationpertinenttothisissuesectsofFloodingand/orMoistureIntrusiononNon-Safety-RelatedandSafety-RelatedEquipment[31]:Floodingandwaterintrusioneventscanaffectsafety-relatedequipmenteitherdirectlyorindirectlythroughfloodingormoistureintrusionofmultipletrainsofnon-safety-relatedequipment.Thistypeofeventcanresultfromexternalfloodingevents,tankandpiperuptures,actuationsoffiresuppressionsystems,orbackflowthroughpartsoftheplantdrainagesystem.TheIPEprocessEnergyResearch,Inc.36ERI/NRC95-504 addressestheconcernsofmoistureintro'tonandinternalflooding(i.e.,tankandpiperupturesorbackflowthroughpartoftheplantdrainagesys!;m).TheguidanceforaddressingtheconcernofexternalfloodingisprovidedinChapter5ofNUREG-I"07,andtheconcernofactuationsoffiresuppressionsystemsisprovidedinChapter4ofNUREG-1407.Thefollowinginformationisprovidedr:l,vanttothisissue:externalfloodingisdiscussedinSection5.2oftheSt.LucieIPEEEsubmittal,andItems2and5ofSection4.8presentsomelimitedinformationconcerninginadvertentactuationoffi;esuppressionsystems.SeismicallyInducedSpatialandFunct'analInteracrions[31]:Seismiceantshavethe.potentialtocausemultiplefailuresofsafety-relatedsystemsthroughspatialandfunctionalin',era:tions.Someparticularsourcesofconcerninclude:rupturesinsmallpipingthatmaydisablee.<<entiai'plantshutdownsystems;directimpactofnon-seismicallyqualifiedstructures,systems,andconponentsthatmaycausesmallpipingfailures;seismicfunctionalinteractionsofcontrolandsafety-reiat";>r>><ectionsystemsviamultiplenon-safety-relatedcontrolsystems'ailures;andindirectimpacts,suchasd~~~'eneration,disablingessentialplantshutdownsystems.AspartoftheIPEEE,itwasspecificallyreque~'..ithatse!smi:allyinducedspatialinteractionsbeaddressedduringplantivalkdowns.TheguidanceforperoiiningsuchwalkdownscanbefoundinEPRINP-6041.TheSt.Lucieseismicadequacyevali:ation{Reference[5])hasincludedaseismicwalkdownwhichinvestigatedthepotentialforadverseIhy~i'alinteractions.RelevantinformationcanbefoundinSection4.7(particularlySection4.7.2.3)ofReference[5].SeismicallyInducedFires~zgjpIign~zJ~~[31]:Sei~~al!yindu'edfiresmaycausemultiplefailuresofsafety-relatedsystems.Theoccurrenceofaseisnii'ventcnuidcreatefiresinmultiplelocations,simultaneouslydegradefiresuppressioncapability,andpreventmitigationoffiredamagetomultiplesafety-relatedsystems.Seismicallyinducedfiresisi>>neaspectofseismic-fireinteractionconcerns,whichisaddressedaspartoftheFireRiskScopingStudy{)=RSS)issues.{IPEEEguidancespecificallyrequestedlicenseestoevaluateFRSSissues.)InIPEEEs,~e~mt."a!l~inducedfiresshouldbeaddressedbymeansofafocusedseismic-fireinteractionswalkdownthatfollowstheguidanceofEPRINP-6041.Section4.8ofthesubmittalverybr!fi~'i~cu<<esseismic-fireinteractions;however,noevaluationofseismicallyinducedfiresisprovided~partoftheSt.LucieIPEEEsubmittal.SeismicallyInducedFireSuppressionSystemActuanon[31]:Seis-">>ceventscanpotentiallycausemultiplefiresuppressionsystemactuationswhich,inturn,maycai'-'-":.iluresofredundanttrainsofsafety-relatedsystems.Analysescurrentlyrequiredbyfireprotectionieg,ilationsgenerallyonlyexamineinadvertentactuationsoffiresuppressionsystemsassingle,independentevents,whereasaseismiceventcouldcausemultipleactuationsoffiresuppressionsystemsinvariousareas.Items2and5ofSection4.8ofthe:-;<<';;i-al;resentsomelimitedinformationpertinenttothisissue.2EnergyResearch,Inc.37ERI/NRC95-504 SeismicallyInducedFloodingtill:WMlyidkfliiillyIiiiiiiofsafety-relatedsystems.Ruptureofsmallpipingcouldprovidefloodsourcesthatcouldpotentiallyaffectmultiplesafety-relatedcomponentssimultaneously.Similarly,non-seismicallyqualifiedtanksareapotentialfloodsourceofconcern.IPEEEguidancespecificallyrequestedlicenseestoaddressthisissue.TheSt.LucieIPEEEsubmittalhasnotincludedadiscussionofseismicallyinducedflooding.SeismicallyInducedRelayChatterWlihW<<ii~qe,ioneofthefollowingconditions:remainfunctional(i.e.,withoutoccurrenceofcontactchattering);~.beseismicallyqualified;or~bechatteracceptable.Itispossiblethatcontactchatterofrelaysnotrequiredtooperateduringseismiceventsmayproducesomeunanalyzedfaultingmodethatmayaffecttheoperabilityofequipmentrequiredtomitigatetheevent.IPEEEguidancespecificallyrequestedlicenseestoaddresstheissueofrelaychatter.AsnotedinSection2.1.9ofthisTER,theSt.LucieIPEEEsubmittaldoesnotmentionrelaychatterevaluation.However,duringNRC'sUSIAWreviewofTurkeyPoint,Units3and4,andSt.Lucie,Unit1,itwasrevealedthatthelicenseehadassessedbadactorrelays,verifiedmountingsofrelays,anddemonstratedthattherewerenodeleteriouseffectsofchatterofbadactorrelays.TheNRCacceptedthelicensee'srelayevaluationforUSIA<6resolution.EvaluanonofEarthquakeMagnitudesGreaterthantheSafeShutdownEarthquake[31]:Theconcernofthisissueisthatadequatemarginmaynothavebeenincludedinthedesignofsomesafety-relatedequipment.AspartoftheIPEEE,alllicenseesareexpectedtoidentifypotentialseismicvulnerabilitiesorassesstheseismiccapacitiesoftheirplantseitherbyperformingseismicPRAsorseismicmarginsassessments(SMAs).Thelicensee'sevaluationforpotentialvulnerabilities(orunusuallylowplantseismiccapacity)duetoseismiceventsshouldaddressthisissue.St.Lucieisdesignatedasareduced-scopeplantinNUREG-1407,andconsistentwiththerelevantguidelinesforareduced-scopeplant,theIPEEEhasconsideredseismicinputequivalenttotheSSElevel.EarthquakeloadsinexcessoftheSSEhavenotbeenconsidered.sectsofHydrogenLineRuptures[31j:Hydrogenisusedinelectricalgeneratorsatnuclearplantstoreducewindagelosses,an'dasaheattransferagent.Itisalsousedinsometanks(e.g.,volumecontroltanks)asacovergas.Leaksorbreaksinhydrogensupplypipingcouldresultintheaccumulationofacombustiblemixtureofairandhydrogeninvitalareas,resultinginafireand/oranexplosionthatcoulddamagevitalsafety-relatedsystemsintheplants.ItshouldbeanticipatedthatthelicenseewilltreatthehydrogenlinesEnergyResearch,Inc38ERI/NRC95-504

,~

~~~1andtanksaspotentialfixedfiresourcesasdescribedinEPRI'sFIVEguide,assesstheeffectsofhydrogenlineandtankruptures,andreporttheresultsinthefireportionoftheIPEEEsubmittal.Section5.3.3oftheSt.LucieIPEEEsubmittalidentifiescompressedhydrogenasapotentialexplosion,source;however,nodiscussionpertainingtohydrogenlinerupturesisprovidedinthesubmittal.EnergyResearch,Inc.39ERI/NRC95-504

~~

3OVERALLEVALUATIONANDCONCLUSIONS3.1SeiSaIlCTheapproachchosenbythelicenseeforrespondingtotheseismicIPEEEdoesnotaddressallrelevantissuesandconcernsforSt.LucieNuclearPlant,areduced-scopesite.AcomparisonofmajorfeaturesoftheFPLseismicadequacyprogramwiththeguidelinesforareduced-scopeseismicevaluation,issummarizedinTable3.1below.Ascanbeseenfromthistable,theprimarydeficienciesoftheFPLapproachare:asignificantlylesserscopeofcomponentsintheFPLapproach;alimitedtreatmentofhumanactionsfortheSt.Luciestudies;andnotreatmentofcontainmentsystemsintheFPLprogram.Table3.1ComparisonofFPL'sSite-SpecificSeismicIPEEEProgramVersusNUREG-1407RecommendedGuidelinesforaReduced-ScoeSeismicEvaluationElementofIPEEEEvaluationWalkdownRelayEvaluauonSoilFailuresScreeningCriteriaSeismicInputEvaluationofOutliersNon-SeismicFailuresandHumanAcuonsContairunentPerformanceAssessmentUSIARSGI-131Reduced-ScopeEvaluationGuidelinesScopeshouldincludeallSSELactivecomponentsandpassivecomponents(structures,raceways,heatexchangers,tanks.piping.etc.)nccdedtoensurecompleteprcferrcdandalternatesuccesspaths.USIAWevaluationforUSIAA6plant;Noevaluationfornon-USIAMplant.Noevaluationisnecessary.SRTjudgment;GIPscreeningguidance;AnchoragecheckbasedonSSEspectmmandFSARin.structureresponsespectrumgRS).SSEspectrumandFSARIRS(ornewmeanplusonc-sigmaIRS).GIPprovisionsforUSIAMItems;FSARrequirementsfornonUSIAMitems.Theseshouldbcqualitativelyaddressed;successpathsarechosentoscreenoutvulnerabilitytotheseitems.Walkdown,screening,andoutlierevaluationofcontainmentstructureandcomponentsofcontainmentsystems.Walkdown,screening,andcvaluauonofdecayheatremovaloutlicrs.Walkdown,screening,andevaluationofseismicadequacyoffluxmappingsystem.FPL'sSite-SpecificSeismicAdequacyProgramScopeincludesSSELactivecomponentsandgt)itspassivecomponents(tanks,heatexchangers);componentlistappearsincomplete;sclectcdsuccesspathsnotidentilicd.USIAA6treatmentofelectricalracewayswasapprovedbytheNRC[7]BadactorevaluationforSt.Lucia-l,approvedbyNRCforUSIAM[71;NoevaluationforSt.Lucie-2.Noevaluation.SRTjudgment;SSRAPboundingspectrum;AnchoragecheckbasedonSSEspectrumandFSARIRS.SSEspectrumandFSARIRS.Conservativecalculationofcapacityversusdcmat;d;demandbasedonconservativeuscofSSEspectrumandFSARIRS;HCLPFcalculationsforlargeQat.bonomedtanksatSt.Lucia-2.Limitedqualitauveevaluationofactionsassociatedwithsuccesspath.Noevaluation.Nospecificevaluation;onlypartiallyaddressedinchosensuccesspath.NotapplicabletoSt.Luci>>.Inaddition,theformatfordocumentingtheseismicIPEEEwasnotwellstructured,anddidnotfollowtherecommendationsofNUREG-1407.EnergyResearch,Inc.40ERI/NRC95-504 Despitethesesignificantdeficiencies,theSt.Lucieseismicevaluationsdo,nonetheless,addresssomemeaningfulIPEEE-relatedconcerns,andhaveresultedinasmallnumberofplantseismicsafetyenhancements.Furthermore,theNRChasalreadyapprovedmanyaspectsofthelicensee'sseismicadequacyevaluationapproachforUSIAWresolution[6,7]thatpertainalsototheseismicIPEEE.Basedonthissubmittal-onlyreview,andinconsiderationoftheNRC'sfindingsforUSIA-46,thefollowingitemsareidentifiedastheprimarystrengthsandweaknessesoftheseismicIPEEEsubmittalforSt.LucieNuclearPlant:1.Thestudyimplementsameaningfulapproachforscreeningandoutlierevaluationofthelimitedsetofcomponentsitaddresses.2.Theuseofhighlyexperiencedseismicwalkdownexpertshasbeenconsistentwiththestudy'sheavyrelianceonSRTjudgments.3.Anumberofoutliershavebeenidentified,andmeaningfulcorrectivesafetyenhancementshavebeenproposed.1.TheSSELisdeficient.2.Aseismiccontainmentperformanceassessmentwasnotconducted.3.Thetreatmentofhumanactionsisdeficient.4.Thesubmittaldoesnotprovideadequatedocumentationofseismic-fire/fioodinteractionconcerns,includingcomponent-specificwalkdownfindings.5.TheseismicIPEEEisincompletewithrespecttoreduced-scopeevaluationrecommendationsfoundinNUREG-1407.6.TheseismicIPEEEsubmittalisnotdocumentedinaccordancewiththeformatrecommendedinNUREG-1407,AppendixC3.2EggThelicenseehasexpendedconsiderableeffortinthepreparationoftheSt.LuciefireIPEEE.TheIPEEEreportcomplieswiththeconditionssetforthinReference[3].Thelicenseehasemployedapropermethodologyanddatabaseforconductingthefireanalysis.TheFIVEmethodologyhasbeenusedforthispurpose.Thefollowingarethestrengthsandweaknessesofthesubmittal:,EnergyResearch,Inc.41ERI/NRC95-504 1.Theoverallpresentationisclearandwell-organized.Therearetaf>lesandfigurestoprovideinformationtosupporttheanalysisandtheconclusions.3.FStatecf-the-artmethodologyandproperdatahavebeenused.Basedonthedatapresented,itcanbeconcludedthatthelicenseehasconductedareasonableanalysis.TheoverallresultsarewithintherangeofconclusionsreachedinotherPWRfireriskstudies.Ecakm~1.ThepossibilityofhotshortsandresultingRCSfailurefromafireeventhasnotbeenaddressedexplicitlyintheIPEEEsubmittal.Firesuppressionsystemfailureprobabilitymaynothavebeenusedproperly.Ifacriticalsetofcablesandequipmentarewithinasmallregionofacompartment,thesuccessfuloperationofthefiresuppressionsystemmaynotmatter.3.Probabilityoffailureoftheredundantequipmentandmodelsusedforarrivingattheconditionalprobabilityofcoredamagegivenafirescenariohavenotbeenexplainedinsufficientdetail.4.Cross-zonefirepropagation,whereactivefirebarriersareemployed,wasnotaddressedexplicitly.Thesubmittaldoesnotprovidesufficientinformationforthereviewerstobeabletoverifysuchaspectsoftheanalysisas:theprobabilityofredundanttrainfailuresgivenafire,fire-inducedinitiatingevents,damagefromfiresuppressionsystemactivation,andfiremodelingandhotshorts.6.Thesubmittaldoesnotaddressthepossibilityofaseismiceventleadingtoafire.7.Thereareseveralcompartmentsforwhichthefrequencyofcoredamageisslightlylessthan10~/ry.Theseareas,althoughmarginallywithinthescreened-outrange,havenotbeenaddressedinanydetail.Certainly,notwithstandingtheaboveobservations,thelicenseehasgainedanimportantexperiencefromtheexerciseofanalyzingtheplantforpotentialfirevulnerabilities.3.3HE~LEzenhIngeneral,theconclusionsofthesubmittalareadequatelysupportedandfollowtheacceptedpracticeandguidelinesofNUREG-1407.ThreecategoriesofHFOeventsareaddressedinsomedetail:highwindsandtornadoes,externalflooding,andtransportationandnearbyfacilityaccidents.Noparticularweaknesseswerefoundinthesubmittalregardingthelasttwocategories.EnergyResearch,Inc.42ERI/NRC95-504 Thefollowingprovidesadescriptionoftheareasinthehigh-winds/tornadoesanalysisthatcontainconclusionswhicharedifficulttoverify:Twooftheintakecoolingwater(ICW)valveoperatorsinthevalvepitwereidentifiedasbeingpotentiallyvulnerabletoverticalmissiles.Ifoneorbothvalvesbecomeinoperable,manualvalvescanbeusedtoensureadequateICWflow.Thereportconcludesthat"sincethevalveoperatorsarelocatedbelowgrade,arephysicallywellseparated,haveanalternatemeansavailabletoisolatethetie-linestotheturbinewatercoolingsystem,andhaveredundantsystemsavailable,"adequatetornadoprotectionhasbeenprovided(page56,lastparagraph).However,thereportdoesnotspecify:(1)whetheraprocedureexists,orsufficienttimewouldbeavailable,forperformingthecited-manualaction;(2)onwhatbasisitisconcludedthatthevalvesare"wellseparated";and(3)wherethealternatecomponentsarelocated.Formanystructures,theinherentcapabilityofthestructurewascreditedtoaccommodateaspecifichazard-forexample,theCCWheatexchangersandpiping(page57,thirdparagraph).Itappearsfromthesubmittalthatifastructureisjudgedtobeabletowithstandasinglemissile,thenithasthecapacitytowithstandsimultaneous(concurrent)impactbyseveralmissiles.Onpage58,lastparagraph,itisstatedthatthedieseloiltanksare"sufficientlyseparatedtoprovideanacceptableleveloftornadoresistancecapability,"withoutprovidingabasisforthisstatement.Onpage59,secondparagraph,itisstatedthat"...acommitmenthasbeenobtainedfromalocalfuelcompany,...,tosupplyfueloilona24-houremergencybasis."However,fromtheexplanationprovidedinthereportitisnotclear:(a)(b)that,intheeventofdieseloilstoragetankunavailability,sufficientonsitefueloilwouldbeavailabletooperatethedieselgeneratorsbeforethearrivaloftheoffsitefueloil;andthattheassumptionthatthelocalfuelcompany'soilsupply,oritsmeansofoildelivery,wouldnotbeaffectedbythesametornadothatispostulatedtohitthesite,isvalid.Inadditiontotheaboveambiguities,determinationofthehazardfrequency(startingfrompage69)issomewhatconfusing,andcontainsthefollowingpotentiallyoptimisticassumptionsandsuppositions:~ThestudyreferencestheNUREG-1407statementthat,iftheoriginaldesigndoesnotmeetthe~bUoriginaldesignbasisissufficientlylow,suchthattheestimatedcoredamagefrequencyislessthan10'/ry(page70).Inthesubmittal,asfaras"tornadoes/highwinds"hazardisconcerned,theabovestatementisinterpretedtomeanthat,ifthecontributiontocoredamagefrequencyasaresultofatornado-induceddamagetoanyonetargetislessthan10~/ry,thenthattargetcanbeexcludedfromfurtherevaluation.Usingthisinterpretation,somepotentialtargetsarescreenedbasedonthelowfrequencyofhazardcriterion,andtheremainingonesbyperformingboundinganalyses(page73).Thisinterpretation,however,isoptimisticandunderestimatesthepotentialrisk.Toscreenahazard,thecumulativeriskinducedbythathazardhastobebelowthescreeningvalue,nottheEnergyResearch,Inc.43ERI/NRC95-504

~~individualrisksfromeachpotentialtarget,since,forexample,atornadocanimpactmorethanonetarget,andwillgeneratemorethanonemissile.Onpage71,thirdparagraph,itisstatedthat,inevaluationoftornadomissiles,inadditiontoweighingtheprobabilityofacertain-intensity-tornadooccurringandgeneratingamissile,thefollowingmustbeconsidered:P4=Probabilitythatamissile,ifgenerated,willimpactthecomponent;P,=Probabilitythat,ifstruck,lossofsystemfunctionoccurs;andP,=Probabilitythatanindependentsinglefailureoccursinthestruckcomponent'sredundantcounterpart.Thesubmittalassumesavalueof10'orP4,byreferencingadocketedShearonHarriscalculationformissileimpactonaservicewaterpump.However,nocomparisonbetweenthecharacteristicsoftheservicewaterpumplocationandthelocationoftheSt.Luciepotentialtargetswasmade.SincetheP,valueishighlylocationspecific,assumingavalueof10'orP,maybeoptimistic.ThesubmittalalsoprovidesascreeningreviewofotherexternaleventsthatmaypresentapotentialsevereaccidentvulnerabilityatSt.LucieUnitsIand2,asummaryofwhichispresentedinTable5-23ofthesubmittal.Basedonthisscreening,forestfiresareclaimedtohaveaminimalpotentialimpactontheplant,andtheimpactisconsideredtobeboundedbylossofoffsitepower.However,thepotentialimpactofsmokegeneratedbythefiresonthecontrolroomhabitability,onequipment,andonlossofcleanairandinstrumentairarenotaddressed.Ingeneral,theapproachappearstobesound.However,acomprehensivescreeningofallpotentialexternalfiresourcesandtheireffectshasnotbeendocumented.EnergyResearch,Inc.ERI/NRC95-504 4IPEEEINSIGHTS,IMPROVEMENTS)ANDCOMMITMENTS4.15ehmzThekeyseismicIPEEEfindingsareprimarilywalkdownrelated;fewquantitativeinsightshavebeenderivedfromtheseismicevaluations.Thus,novaluesforseismiccoredamagefrequency,plant-levelfragilitycapacitynorplant-levelHCLPFcapacityhavebeenestimatedasaresultoftheseismicIPEEE.TheseismicadequacyevaluationforSt.Lucie-Irevealedanumberofoutliersforwhichsafety.enhancementshavebeenproposedorimplementedinresponsetoUSIA46;interactionconcernswerealsonoted.ForSt.Lucie-2,findingsrelatedtointeractionconcerns,butnooutlierswerenoted.EnhancementsforIPEEE-onlycomponents,(i.e.,componentsoutsidethenormalscopeofUSIA46,butwithinthescopeofIPEEE)werenotaddressed.Inaddition,containmentperformanceevaluationandevaluationofhumanactionswerenotincludedaspartofthelicensee'streatmentofseismicIPEEEconcerns.Thenotedconditions,andproposedsafetyenhancements,aresummarizedbelow:Sr.LucieUnitIDuringthewalkdowns,fiveanchoragesandthecomponentcoolingwatersurgetankplatformwereidentifiedasconcernsbytheSRT.Inadditiontothesefiveanchorageconcerns,sixadditionalanchorageconcernswereidentifiedbyFPLforsimilarcomponentsindifferentequipmenttrains.Themodificationsundertakenfortheidentifiedconcernsaredescribedbelow:-Theexistinganchorboltsarecorroded.Therepairmodificationforthetanksinvolvestheremovalofallexistingcorrosion,applicationofprotectivecoatings,installationofcoverplatestoencloseeachanchorboltpocket,andapplicationofafillermaterialtoprotecttheboltsfromfuturecorrosion.IbibibkdTheanchoragemodificationinvolvestheadditionofsupplementaryfilletweldsalongtheinteriorofthecabinetbase.-Thecabinetisburned-throughinareasnearexistingwelds.Themodificationconsistsofscrewingclipanglestothesidesofthecabinetandanchoringtheclipanglestothewallbehindthecabinet,usingexpansionanchorbolts.-Filletweldsaremissingbecausetheexistingembeddedsupportchannelsarenotproperlylocated.Themodificationconsistsofinstallingplatestoconnectthebaseofthecabinetstotheembeddedchannels.-Severalbracingmembersrequiredbytheoriginalplatformdesignaremissing.Themodificationrequiresinstallationofadditionalstructuralmembers,toincreaselateralstiffness,andrelocationofaninstrumentairlineandthreetankdrainlines.j-Thisloadcenterisforthepressurizerheater,anditconsistsof.threecabinetswithweakanchorage.Themodificationsinclude:(a)insuringthatthecabinetsareEnergyResearch,Inc.45ERI/NRC95-504

~ft adequatelyconnected,sotheywillactasasingleunitunderseismicloading;and(b)addingfilletweldsattheinteriorbaseofloadcentercabinetstoanchorthemtotheembeddedchannels.ThefollowingseismicinteractionconcernsatUnit1werealsonoted:Potentialinteractioninvolvingtheglasssitetubeforthecomponentcoolingwatersurgetank.2.Potentialinteractioninvolvingablockwalladjacenttothecomponentcoolingwatersurgetank.3.Anoverheadcraneadjacenttotheintakecoolingwaterpumpshouldbesecuredawayfromthepump.Inaddition,somecasesofpoorseismic"housekeeping"wereobservedanddocumented.InresponsetotheNRC'sUSIA46reviewprocess,thelicenseeisimplementingaprogramofstrictseismichousekeeping.St.LucieUnit2Twoseismicinteractionconcernswerenoted:1~Possibletippingofacabinetnearsafety-relatedequipment;and2.Questionablesupportofacomponentmountedabovesafety-relatedequipment.Bothoftheseissueswereultimatelyevaluatedandresolved.HCLPFcalculationswereperformedforanumberoflargestoragetanksatUnit2;thesecalculationsdemonstratedthecapacitiestobebeyondthedesignbasis.'concernwasalsonotedpertainingtowhether'ornotthemountingofsomeinternalcoilsinanenergizedtransformerwasseismicallyadequate.Thisconcernwasinvestigatedduringanoutage,anditwasfound'hatthemountingwasadequate.Itwasalsostatedintheseismicevaluationthatawalkdownofwalltransformersneededtobeperformed,todeterminewhetherornotthesetransformerswouldneedtobesecured.Inaddition,thepeerreviewresultedinthefollowingadditionalfindingswhichhavebeenaddressed:Secureloadcenterover-cabinetcrane/winches,andverifythattoolboxcartintheswitchgearroomiseitherremovedorproperlysecured.Secureorremovel&Clockerfromcontrolroom.Reducebatteryrackendgapsonthe2Aand2Bbatteries.Implementcontrol-roomhousekeepingimprovementsregardingstorageofScottAirPacksandimmobilizinganunsecuredlocker.EnergyResearch,Inc.-46ERI/NRC95-504 4.2Overall,thelicenseehasconcludedthattherearenosignificantfirevulnerabilitiesatSt.Lucie.Withtheexceptionofthecontrolroom,cablespreadingroom,andthe"B"Switchgearroom,allfirezonesandareaswerescreenedoutbasedon10~/rycoredamagefrequencycriterion.Thecoredamagefrequenciesforfiresinthecontrolroomswereconcludedtobe7.49x10'/ryand5.90x10'/ryforUnitsIand2,respectively.Forthecablespreadingrooms,thecoredamagefrequencieswereevaluatedtobe6.95x10'/ryand5.64x10'/ryforUnits1and2,respectively.Forbothareas(i.e.,controlroomandcablespreadingroom),thelicenseehascitedseveralconservativeassumptionsinfireoccurrencerateandfireseverity,andconcludedthatthesetwoareasdonotposeavulnerability:Thecoredamagefrequencyofafireinthe"B"switchgearroomwasconcludedtobe4.30x10'/ryand4.48x10~/ryforUnits1and2,respectively.Firepropagationmodelinghasbeenperformedforthisarea,andthelicenseehasconcludedthatfirewillnotpropagatethroughouttheroom.TheentirefireIPEEEeffort,ofcourse,hasprovidedanexcellentopportunityforthelicensee'sengineerstobetterlearnaboutthecharacteristicsoftheplant,theplantbehaviorunderdifferentfireconditions,andtheimpactofhumanactionsthatarenecessarytoprotectthereactorfromanyadverseeffects.4.3HEQXmdsTheIPEEE'soverallconclusionregardingthiscategoryofexternaleventsisthatanypotentialcoredamagescenariohasanextremelylowfrequencyincomparisonwiththefrequencyofcoredamagefromotherinitiators.Asaresult,nosafetyenhancementshavebeenidentified,andconsequently,nocommitmentsaremadethatwouldrequiretrackingbytheNRC.EnergyResearch,Inc.47ERI/NRC95-504 5IPEEEEVALUATIONANDDATASUMMAI(YSHEETSCompleteddataentrysheetsfortheSt.LucieNuclearPlantIPEEEareprovidedinTables5.1to5.6.ThesetableshavebeencompletedinaccordancewiththedescriptionsinReference[11].Table5.1liststheoverallexternaleventsresults.Table5.2summarizesgeneralseismicdatapertainingtotheevaluation.Tables5.3providestheSeismicSuccessPathsOverviewTable,andTable5.4summarizessequenceinformationforPWRSeismicSuccessPaths.AccidentsequenceinformationprovidedinTables5.5and5.6forfireeventsareonlypartiallycompletedduetolackofsufficientinformationprovidedinthesubmittal[1]andReference[14].AccidentsequencetablesarenotprovidedforHFOevents,sincenoPRAanalyseswereperformedfortheseevents.EnergyResearch,Inc.48ERI/NRC95-504 Tahle5.1ExternalEventsResultsPlantName:EventExternalFireScreening0CDFPlantHCLPF(g)NotesExternalFlooding0ExtrcmeWinds0InternalFireNearbyFacilityAccidents0SeismicActivityTransportationAccidents0Others0HazardouschemicalsandlightningScrccning:S=Plantspecificanalysis;0=Screenedout;SO=BoundinganalysisEnergyResearch,Inc.49ERI/NRC95-504 1

Table5.2SSMSeismicFragilityPlantName:~MphReviewLevelEarthquake(g):SpectralShape:'ig'NUREG4098,NRCGuide1.60,10,000yearLLNLmedianUHS,SiteSpecific,orother)ListcomponentsandequipmentswhichdonotmeetRLE(allcomponents)orwithlowestHCLPF(lessthan10):Component'ondensateStorageTank(Unit2)RWST(Unit2)DieselOilStorageTank(Unit2)BoricAcidMakeupTanks(Units1and2)HCLPF(g)>0.3g(but(0.49g)>0.3g(hut(0.64g)1.47gSeismicSequenceDescriptionSeismicSuccessPathDescriptionNotalllowestHCLPFswerereported;reduced-scopeevaluation.EnergyResearch,Inc.50ERI/NRC95-504 Table59PWRSuccessPathOverviewTablePlantName:~+ggjiSequenceSuccessPathPDSHCLPF(L)'nitEventT-LOOPSuccessSupportsEAC,CCW,ESWNon-FailedFunctionsAttributesjttjLatssLjjttjtjsxtn:oneoftbe(oasis)nstsi,S2.s3,A,v[.ss),T.Loot',T-Rx,T-Tf,T-hlvrs,T.UHs,T-RcP.T.LNMv.T.LMptv,T.Expttr.TQBoc.T<LBIc,T~T~Rvlloav,TWCI,T-(other),orT-(SupportSystem)(.xs)referstooptionalsuppkmentatymater(al.QSISI~sSISBthtmostteooftbefoaesdeS:AC.ACBUI.ACSV2,ACBU3,AUXC~AVXC3.AUXGI.CCIVIDC,EAC,EDC,ESASI,ESAS2,ESttr,HVACI,HVAC2.HVAC3,IA.NIT,OA3,OA4,SA,SIM,StV2,SNr3,S)Vd,VAC(p)aidmaybeblast).tt~tjjDLK)ttt(3jst)tthtmostthreeofthefoaosrbtftsINT,sDEp,ssMU,RcssoR.Rcs!NT.RcsDEp,Hpl,HPR,LPI.LpR,cpsi,cpsRclp.YENT(lfs4thand/or3thsieneoessary,usetheNotesrield)iBBjj3autAtmosttbseeoftbefoaotshtftATWS,SYPASS,11L,IND4GIR,SBO,ORHUM(Valdmsybebien))Redused-SeepsPlanenoHCLPPrapash)etispotted.EnergyResearch,Inc.51ERI/NRC95-504 Tahle5.4PWRSeismicSuccessPathsPlantName:CHALLENGESTRATF.GYSUCCESPA'rHPRIMARYINTEGRITYPPRAACDDPI2SRBPPPIPSS0RRVVCHLAIiprcPIICIAIIPRIMARYINVENTORY-INJECllONAI2CHPRHLAPPRRRIAR2PRIMARYINVENTORY-.RECIRCSECONDARYINTHiRITYSSTGGTSAMSIVSECONDARYINVENTORYTSMBGiFWNISPAAAFMMWI2M3CCFSSCI2IFC2ICCCIII2CONTAINMENTI(INRFNOTEST.LoopggggggOneofthcfolkstgSl.S2.S3.A.V(xx).TLOOPTRX,TTr.TA1WS.TUHS.TRCP.T.LNMII.TMFWTEXFWT-SUIOC,TCUIIC.T.SOT)AT-SORY/IORV,T~l.T-(Other).ORT.(SupportSystem).(.xx)referstooptionalsuppkmcntarymaterial.AcronymofSupportSystems:AC,ACBUI,ACB'II2,ACBU3.AUXC2.AUXC3.AUXC4,CCW.DC.EAC,EDC,ESASI,ESAS2.ESW.IIVACI.HVAC2,HVAC3.IA.NIT,OA3,OA4,SA,STM.SW2,SW3.SW4,VACI,2,3...HowmanyneededtooperateHwHumanactknrequiredT=MustbcthmttkdlcontrollcdForCoreDamagePreventionChallenges,showonlyhanlwarewhosefailureismodckdascontributingtocoredamage.EnergyResearch,Inc.I52ERI/NRC95-504 C.Table5.5PWRAccidentSequenceOverviewTablePlantName:iniiForFirePRAOnlyIhfSequenceUnitI-ControlRoomPDSCDF7.49x10-s/Init.EventLostSupportsFailedFunctionsAttributesUnitI-CableSpreadingRoom6:96x10'/ryUnitI-BSwitchgcarRoom4.30x10's/ryT-RX(inferred)SSMUUnit2-ControlRoom5.90x10s/ryHUMUnit2-CableSpreadingRoom5.64x10'/ryUnit2-BSwitchgcarRoom448x10s/ryT-RX(inferred)SSMU,HPIHUM,TIL(infcrrcd)FA-121/51W2.67x10'/ryT-RX(infcrrcd)SSMUHUM,TIL(infcrrcd).FAW1.34x10s/ryT-RX(inferred)EPSSMUHUM,TIL(inferred)TQO!her),orTgsupportSystem)(-xx)referstooptionalsupplementaryinataiat.rIdtstSutltRxt<AtmosttwooFthefollowing:AC,ACBU1,ACBU2,ACBU3,AUXC2.AUXC3,AUXC4,CCW,DC,EAC,EDC,ESAS1,ESAS2,ESW,HVACI,HVAC2,HVAC3,IA.NIT,OA3,OA4,SA,STM,SW2,SW3,SW4,VAC(Fieldmaybeblank).~aikdutldsistn:Atmostthfeeofthefollowing:SINT,SDEP,Sshfu,RC<BOR,RCS-INT,RCS-DEP,HPI,HPR.LPI,LPR.CPSI,CPSR,CIF,VENT(lfa4thand/or5tharenecessary,usethe"Notes"Iield)~luilI:AlatadlhrflhfllaaiaSATASS,BYPASS,TIIRI~GTR.SBO,ORIIIMIFiidaaayhahla&IEnergyResearch,Inc.53ERI/NRC95-504 tqt Table5.6PWRAccidentSequenceDetailedTablePlantName:ForFirePRAOnlyPRIMARYINTEGRITYPRIMARYINVENTORY-INJECTIONPRlhIARYINVENTORY-RFXIRCSECONDARYINTEGRITYSECONDARYINVENTORYCONTAINMENTSEQUENCEUnitI-ControlRoomUnitI-CableSprctalinaRoomUnitI~8SwitchgcarRoom.Unit2-ControlRoomUnit2-CableSprcralinaRoomRPSPPPPSA0RDRVIV122112PRCHACHPDPI'2SI?1LPIAACICAI2CHHPPRR172272AASRRG2SSGATMTTS8IVSGMNAFIFWSWPXXXXXXXXAMIAACMMS23ICS2FFICCCI2CIICIRIGF2NHflMXNOTESlinit'2-8SwitchacarRoom7FA.I2IISIWFA.OXXIEnergyResearch,Inc.54ERI/NRC95-504 6REFERENCES"IndividualPlantExaminationofExternalEventsforSt.LucieUnits1and2,"FloridaPowerandLightCompany,December1994.2."IndividualPlantExaminationofExternalEvents(IPEEE)forSevereAccidentVulnerabilities-10CFR50.54(f),"U.S.NuclearRegulatoryCommissionGenericLetter88-20,Supplement4,June28,1991.3.J.T.Chen,etal.,"ProcedureandSubmittalGuidancefortheIndividualPlantExaminationofExternalEvents(IPEEE)forSevereAccidentVulnerabilities,"U.S.NuclearRegulatoryCommission,NUREG-1407,June1991.'."VerificationofSeismicAdequacyofMechanicalandElectricalEquipmentinOperatingReactors,"U.S.NuclearRegulatoryCommissionGenericLetter87-02,February1987.5."PlantSpecificSeismicAdequacyEvaluationofSt.LucieUnit1toResolveUnresolvedSafetyIssue(USI)AMandGenericLetter8742,"preparedforFloridaPowerandLightCompanybyStevensonandAssociates,February18,1992.6."EvaluationofSt.LucieUnit1,andTurkeyPointUnits3and4,ResolutionofUnresolvedSafetyIssue(USI)AA6,SupplementNumber1toGenericLetter87-02,"U.S.NuclearRegulatoryCommission,StaffEvaluationReport,June20,1995.7."SupplementalSafetyEvaluationReportofSt.LucieUnit1andTurkeyPointUnits3and4,ResolutionofUnresolvedSafetyIssue(USI)A-46,"U.S.NuclearRegulatoryCommissioninternalmemorandumfromRichardH.Wessman,ChiefoftheMechanicalEngineeringBranch,toHerbertN.Berkow,DirectorforProjectDirectorateII-2,September19,1996.8."StandardReviewPlanfortheReviewofSafetyAnalysisReportforNuclearPowerPlants,LWREdition,"U.S.NuclearRegulatoryCommission,NUREG-0800(formerlyissuedasNUREG-75/087),June1987.9.R.T.Sewell,etal.,"IndividualPlantExaminationforExternalEvents:ReviewGuidance,"ERI/NRC94-501(Draft),May1994.10."IPEEEStep1ReviewGuidanceDocument,"U.S.NuclearRegulatoryCommission,June18,1992.11.S.C.LuandA.Boissonnade,"IPEEEDatabaseDataEntrySheetPackage,"LawrenceLivermoreNationalLaboratory,December14,1993.12."plantSpecificSeismicAdequacyEvaluationofSt.LucieUnit2toResolveGenericLetter88-20,Supplement4,"preparedforFloridaPowerandLightCompanybyStevensonandAssociates,January31,1995.II"IndividualPlantExaminationReportforSt.LucieUnits1and2,"FloridaPowerandLightCompany,April1992.EnergyResearch,Inc..55ERI/NRC95-504 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30."IndividualPlantExaminationofExternalEventsforTurkeyPointUnits3and4,"FloridaPowerandLightCompany,June1994.31."Sta6'GuidanceofIPEEESubmittalReviewonResolutionofGenericorUnresolvedSafetyIssues(GSI/USI),"U.S.NuclearRegulatoryCommission,August21,1997.EnergyResearch,Inc.57ERI/NRC95-504