ML17229A397

LER 97-004-00:on 970611,discovered Incorrect Original Cable Tray Fire Stop Assembly Installation Was Outside App R Design Basis.Caused by Personnel Error.Hourly Fire Watch Patrols Will Be posted.W/970711 Ltr

ML17229A397
Person / Time
Site:	Saint Lucie
Issue date:	07/11/1997
From:	FREHAFER K W, STALL J A FLORIDA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
L-97-179, LER-97-004-02, LER-97-4-2, NUDOCS 9707150008
Download: ML17229A397 (7)

Text

('A.'l'EQO8.2REGULATIOINFQRMATIQNDIBTRIBUTIor~sTEM(RIDE)!ACCESSIONNBR:9707150008DOC.DATE:97/07/11NOTARIZED:NOFACIL'.50-389St.LuciePlant,Unit2,FloridaPower&LightCo.AUTH.NAMEAUTHORAFFILIATIONFREHA:ER,K.W.FloridaPower&LightCo.STALL,J.A.FloridaPower6LightCo.RECIP.NAMERECIPIENTAFFILIATIONDOCKET¹05000389

SUBJECT:

LER97-004-00:on970611,discoveredincorrectoriginalcabletrayfirestopassemblyinstallationoutsideAppRdesignbasis.Causedpersonnelerror.Postedhourlyfirewatchpatrols.W/970711ltr.DISTRIBUTIONCODE:IE22TCOPIESRECEIVED:LTR'NCLSIZE:TITLE:50.73/50.9LicenseeEventReport(LER),IncidentRpt,etc.NOTES:RECIPIENTIDCODE/NAMEPD2-3PDINTERNAL:ACRSAEOD/SPD/RRABNRR/DE/ECGBNRR/DE/EMEBNRR/DRCH/HICBNRR/DRCH/HQMBNRR/DSSA/SPLBRES/DET/EIBEXTERNAL:LSTLOBBYWARDNOACPOOREFW.NRCPDRCOPIESLTTRENCL111111111111111111111111RECIPIENTIDCODE/NAMEWIENSFL~AEOD/SPD/RABET~KRONENRR/DRCH/HHFBNRR/DRCH/HOLBNRR/DRPM/PECBNRR/DSSA/SRXBRGN2FILE01LITCOBRYCE,JHNOACQUEENERFDSNUDOCSFULLTXTCOPIESLTTR'ENCL112211111111111111111111NOTETOALL"RIDS"RECIPIENTS:PLEASEHELPUSTOREDUCEWASTEICONTACTTHEDOCUMENTCONTROLDESK,ROOMOWFNSD"5(EXT.415-2083)TOELIMINATEYOURNAMEFROMDISTRIBUTIONLISTSFORDOCUMENTSYOUDONTNEEDrFULLTEXTCONVERSIONREQUIREDTOTALNUMBEROFCOPIESREQJIRED:LTTR25ENCL25 FloridaPower&LightCompany,6501SouthOceanDrive,JensenBeach,FL34957July11,1997L-97-17910CFR50.73U.S.NuclearRegulatoryCommissionAttn:DocumentControlDeskWashington,D.C.20555Re:St.LucieUnit2DocketNo.50-389ReportableEvent:97-004DateofEvent:June11,1997IncorrectOriginalCableTrayFireStopP~TheattachedLicenseeEventReportisbeingsubmittedpursuanttotherequirement'sof10CFR50.73toprovidenotificationofthesubjectevent.Verytrulyyours,J.A.StallVicePresidentSt.LuciePlantJAS/KWFAttachmentl/(W)cc:RegionalAdministrator,USNRCRegionIISeniorResidentInspector,USNRC,St.LuciePlant'Ir7071500089707iXPDRADOCK0500038'PSPDRanFPLGroupcompanyiliillllllllllllllllllllllllIllslllllll NRCFORM366(4.95)U.S.NUCLEARREGULATORYCOMMISSIONLZCENSEEEVENTREPORT(LER)(Seereverseforrequirednumberofdigits/charactersforeachblock)APPROVEDSYOMSNo.3160%I04Exp)RES04)3ore6ESTIMATEDBURDENPERRESPONSEToCOMPLYWITHTHISMANDATOINFORMATIONCOLLECTIONREGUEST:60.0HRS.REPORTEDLESSONLEARNEDAREINCORPORATEDINTOTHEUCENSINGPROCESSANDFEBACKTOINDUSTRY.FORWARDCOMMENTSREGARDINGBURDENESTIMATToTHEINFORMATIONANDRECORDSMANAGEMENTBRANCHIT%F33)U.S.NUCLEARREGIAATORYCOMMISSION.WASHINGTON,OC206664KO)ANDTOTHEPAPERWORKREDUCTIONPROJECTI3160<104),OFFICE0MANAGEMENTANDBUDGET,WASHINGTON,DC20603.FACIUTYNAME(1)STLUCIEUNIT2DOCKETNUMBER12)05000389PAGE13I1OF4TITLEI4)IncorrectOriginalCableTrayFireStopAssemblyInstallationOutsideAppendixRDesignBasesMONTHDAYYEAR1197SEQUENTIALREVISIONNUMBERNUMBER97-004-0MONTHDAYYEAR97FACIUTYNAMEFACILITYNAMEDOCKETNUMBER05000DOCKETNUMBER05000OPERATINGMQDE(9)POWERLEVEL(10)10020.2201(b)20.2203(a)(2)(i)20.2203(a)(2)(iii)20.2203(a)(2)(iv)20.2203(a)(2)(v)20.2203(a)(3)(n)50.36(c)(1)50.36(c)(2)50.73(a)(2)(1)50.73(a)(2)(iii)50.73(a)(2)(v)50.73(a)(2)(vii)50.73(a)(2)(viii)73.71OTHERSpecifyinAbstractbeloworinNRCForm3BSANAMEK.W.Frehafer,LicensingEngineerTELEPHONENUMBERSecludeAreeCode)(5611468-4284CAUSESYSTEMCOMPONENTMANUFACTURERREPORTABLETONPRDS,x:,t,;4(..NkÃ"'9):AcAusEsYsTEMcoMpoNENTMANUFACTURERREPORTABLEToNPRDSYEs(Ifyes,completeEXPECTEDSUBMISSIONDATE).XNoEXPECTEDSUBMISSIONDATE(15)MONTHOAYYEARABSTRACT(Limitto1400spaces,i.e.,approximately15single-spacedtypewrittenlines)(16)OnJune11,1997,St,LucieUnit2wasinMode1at100percentpower.Inspectionresultsindicatedthat,generically,twosidedcabletrayfirestopassemblieslackedtheinstallationofceramicfiberbetweencableswithinthefirebarrier.FPLdeterminedthattheas-builtconfigurationoftwosidedcabletrayfirestopassembliesdidnotmeetthetestedconfigurationforathreehourfireratedassembly.AlltheSt.LucieUnit2twosidedcabletrayfirestopassembliesweredeclaredinoperable.Theapparentcauseofthiseventwasduetopersonnelerrorduringtheimplementationofdesigndrawingsorinsufficientdesignguidanceduringinitialinstallation.Correctiveactionsincludethepostingofhourlyfirewatchpatrolsthatwereestablishedtocompensatefortheinoperablefirestopassemblies.Repairsorplantmodificationswillbeimplementedtorestoretheaffectedfirestopassembliestotheirrequiredthreehourfirerating.NACFOAM366(4.95)

NRCFORM366AI4-9SILICENSEEEVENTREPORT(LER)TfXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIOSTLUCIEUNIT205000389YEARSEQUENTIALREVISION97-004-02OF4TEXTIlfmorespaceisrequired,useadditionalcopiesofiVRCForm366Ai(17lOnJune11,1997,St.LucieUnit2wasinMode1at100percentpower.FPLwasinvestigatingdiscrepanciesoftwosidedcabletrayfirestopassembliesidentifiedduringpreviousfieldsurveillances.Intrusiveinspectionsoftheremainingpopulationoffirestopassembliesofthisdesignwereinprogresstodeterminetheextentoftheissue.Preliminaryinspectionresultsindicatedthat,generically,theas-builtconfigurationoftwosidedcabletrayfirestopassemblieslackedtheinstallationofceramicfiberbetweencableswithinthefirebarrier.TheconfigurationdidnotconformtothedesigndrawingsandFPLascertainedthattheidentifiedfieldconditionswerenotpreviouslyevaluatedduringinitialconstruction.Therefore,thetwosidedcabletrayfirestopassembliesdidnotmeetthetestedconfigurationforathreehourfireratedassembly,asrequiredbytheplant10CFR50AppendixRcommitments.Asaconservativemeasure,alltheSt.LucieUnit2twosidedcabletrayfirestopassembliesweredeclaredinoperablebasedonthepreliminaryinspectionresults.Hourlyfirewatchpatrolswereestablishedascompensatorymeasuresasrequiredbyplantadministrativeprocedures.St.LucieUnit1doesnotutilizecabletrayfirestopsofthisdesign,sothisconditionisonlyapplicabletoUnit2.Areviewoftheoriginalinstallationandinspectiondocumentationfortheconstructionofthetwosidedcabletrayfirestopassembliessuggeststhattheapparentcauseofthiseventwasduetopersonnelerrorduringtheimplementationofdesigndrawingsorinsufficientdesignguidanceduringinitialinstallation.Acontributingcausewasthattheinstallationdrawingswerenotclearinspecifyingthatceramicfiberneededtobeinstalledaroundeachcableinthefirestopassembly.Thisconditionwasdiscoveredduringarecentfirestopsurveillance.ConsistentwiththeIndustry,normalfirebarrierinspectioncriterionisavisualinspectionofexposedsurfacescheckingforvoids,gaps,andholes.Nointrusiveinspectionsordisassemblingoffirebarriersareperformed.Oneofthefirestopswaslocatedsuchthatavisualinspectionwasdifficulttoperform,sotheinspectorranhishandaroundthefirestoptocheckforvoids,gaps,'andholes.Theinspectornotedairflowbetweencablesthroughtheassembly.Althoughairflowwasnotedduringthatinspection,routinedetectionofairflowthroughadiscrepantfirestopisproblematicinnatureandhighlydependentontheexistenceofadifferentialpressureacrossthefirebarrier.Evenifpreviousinspectionswereperformedinahandsonmanner,adifferentialpressurecouldnotbeassuredbecauseofReactorAuxiliaryBuildingventilationlineupordoorconfigurationsineffectduringtheinspection.Thisconditionisreportableunder10CFR50.73(a)(2)(ii)(B)becausetheasfoundconditionoftheUnit2twosidedcabletrayfirestopassembliesdonotmeetthreehourfirebarrierrequirements.ThefirebarriersarediscussedintheUnit2.UFSARinchapter9.5A.Theprincipaldesignobjectiveofthefirebarrierandassociatedpenetrationsealsistoprotectpersonnelandredundantequipmentfromtheeffectsofpostulatedfiresinthereactorauxiliarybuilding,toassurethecapabilitytoachievesafeshutdowninaccordancewith10CFR50AppendixRandBTP9.5-1AppendixA.Thebarriersandassociatedpenetrationsealsarepassivedevicesandarepartoftheplantfireprotectionsystem.NRGF0AM366AI4-95I C,4NRCFORM366AI4-9SILICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIOSTLUCIEUNIT205000389YEARSEQUENTIALREVISION97-004-03OF4TEXT/Ifmorespeceisrequired,useedditionelcopiesofNRCForm366AJl17)TheceramicfiberbetweenthecablesisanextensionoftheMariniteboard(ceramicfiberboard)firestopface.Thisceramicfiberservestoresistheat,flame,andsmokepropagationthroughthefirestop.Inconjunctionwiththeflameretardantthisisaneffectivethreehourfireratedassembly.(SeeFigure1fortypicaldesigndetails).However,withouttheceramicfiberbetweenthecablesapathforheatandsmokepropagationisprovided.Thisisasmallandtortuouspathinthatthespacebetweenthecablesistypicallysmall.Theheatwouldstillneedtotravelatleastonefootdownthetraywheretheflameretardantisapplied,thenwouldenteralargeopenspaceinthewall,andwouldthenneedtoexitthroughanotherfootofconfinedspacebetweencablesonthenon-firesideoftheassembly.Localizedhotspotswouldexist.TheIEEE-383cableswillresisttheeffectsoftheincreasedtemperaturesandhelptopreventtheignitionofcableinthenon-firesideoftheassembly.Thetwosidedcabletrayfirestopdeficiencieswereevaluatedanddeterminedtobenotsafetysignificant.Although'theas-foundconditionofthesecabletrayfirestopswasnotinaccordancewiththetestedanddesignconditions,andwouldprobablynotmeetathreehourfireratingwithouttheceramicfiberbetweenthecables,theinstallationdoesprovideresistancetofirepropagation.Inaddition,fireprotectiondefenseindepthprovidesanintegratedmeansformitigatingtheconsequencesofafire,suchastheexistingsmokedetectionsystems,automaticwaterfiresuppressionsystems,hosestations,administrativeprogramsthatcontrolcombustibleloading,andoperatoractions.Basedontheabove,itisconcludedthatthehealthandsafetyofthepublicwerenotadverselyaffectedbytheconditionoftheSt.LucieUnit2twosidedcabletrayfirestopassemblies.Thehourlyfirewatchpatrolswereestablishedtocompensatefortheinoperabletwosidedcabletrayfirestopassembliesasrequiredbyplantadministrativeprocedures.FPLwilleitherreworktheassociatedfirestopassembliestotheiroriginaldesignordevelopandimplementanewdesigntorestorethedegradedbarrierstoathreehourfirebarrierrating.None.

NRCFORM366AI495ILICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIOSTLUCIEUNIT205000389YEARSEQUENTIALREVISION97-004-04OF4TEXT(ifmorespoceisrequired,usoadditionalcopiesofNRCArm3MAlI17)TWO-SIDEDCABLETRAYSEALINFLOOR/WALLOPENINGFIRESTOP2"CERAMICFIBERPLUGSFLAMERETARDANTMARINITE-IBOARDFLAMERETARDANT(MJOWO!eeRotFigure1TypicalTwoSidedCableTrayFireStopAssembly