ML17229A539

LER 97-010-00:on 971027,inadvertant Core Alteration Prohibited by TS Occurred.Caused by CEA Failure to Detach from Ugs.Safety Evaluation Was Performed & Procedural Rev Made to Continue Upper Guide Structure move.W/971126 Ltr

ML17229A539
Person / Time
Site:	Saint Lucie
Issue date:	11/26/1997
From:	REVELL J, STALL J A FLORIDA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
L-97-297, LER-97-010, LER-97-10, NUDOCS 9712030199
Download: ML17229A539 (6)

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CATEGORY1SREGULATEYINFORMATIONDISTRIBUTIONSTEM(RIDS)ACCESSIONNBR:9712030199,DOC.DATE:97/11/26NOTARIZED:NOFACXL:50-335St.LuciePlant,Unit1,FloridaPower&LightCo.AUTH.NAMEAUTHORAFFILIATIONREVELL,J.FloridaPower&LightCo.STALL,J.A.FloridaPower&LightCo.RECIP.NAMERECIPIENTAFFILIATIONDOCKET¹05000335

SUBJECT:

LER97-010-00:on971027,inadvertantcorealterationprohibitedbyTSoccurred.CausedbyCEAfailuretodetachfromUGS.Safetyevaluationwasperformed&proceduralrevmadetocontinueUGSmove.W/971126ltr.DISTRIBUTIONCODE:IE22TCOPIESRECEIVED:LTRiENCLSIZE:l5TITLE:50.73/50.9LicenseeEventReport(LER),IncidentRpt,etc.NOTES:ERECIPIENTIDCODE/NAMEPD2-3PDINTERNAL:ACRSAEOD/SPD/RRABNRR/DE/ECGBNRR/DE/EMEBNRR/DRCH/HICBNRR/DRCH/HQMBNRR/DSSA/SPLBRES/DET/EIBEXTERNAL:LSTLOBBYWARDNOACPOORE,W.NRCPDRCOPIESLTTRENCL111111111111111111111111RECIPIENTIDCODE/NAMEWIENS,L.ILECENTNRRNRR/DRCH/HHFBNRR/DRCH/HOLBNRR/DRPM/PECBNRR/DSSA/SRXBRGN2FXLE01LITCOBRYCE,JHNOACQUEENER,DSNUDOCSFULLTXTCOPIESLTTRENCL1122111111111111'111111110D0UNOTETOALL"RIDS"RECZPZENTSPLEASEHELPUSTOREDUCEWASTE.TOHAVEYOURNAMEORORGANIZATIONREMOVEDFROMDISTRIBUTIONLISTSORREDUCETHENUMBEROFCOPIESRECEIVEDBYYOUORYOURORGANIZATION,CONTACTTHEDOCUMENTCONTROLDESK(DCD)ONEXTENSION415-2083FULLTEXTCONVERSIONREQUIREDTOTALNUMBEROFCOPIESREQUIRED:LTTR25ENCL25 FloridaPower&LightCompany,650tSouthOceanDrive,JensenBeach,FL34957FPLNovember26,1997L-97-29710CFR50.73U.S.NuclearRegulatoryCommissionAttn:DocumentControlDeskWashington,D.C.20555Re:St.LucieUnit1DocketNo.50-335ReportableEvent:97-010DateofEvent:October27,1997InadvertantCoreAlterationProhibitedbyTechnicalSpecificationsDuetoStuckControlElementAssemblCEATheattachedLicenseeEventReportisbeingsubmittedpursuanttotherequirementsof10CFR50.73toprovidenotificationofthesubjectevent.Verytrulyyours,J.A.StallVicePresidentSt.LuciePlantJAS/JWRAttachmentcc:RegionalAdministrator,USNRC,RegionIISeniorResidentInspector,USNRC,St.LuciePlant,ijc4/97i2030i'tt997ii26PDRADQCK050003358PDRlbltttliltjtlllttltajiNIanFPLGroupcompany NRCFORM366(4.95)U.S.NUCLEARREGULATORYCOMMISSIONLICENSEEEVENTREPORT(LER){Seereverseforrequirednumberofdigits/charactersforeachblock)APPROVEDBYOMBNo.31604I104EXRRES04I30/SSESTIMATEDBURDENPERRESPONSETOCOMPLYWITHTHISMANDATORINFORMATIONCOLLECTIONREQUEST:60.0HRS.REPORTEDLESSONLEARNEDAREINCORPORATEDINTOTHEUCENSINGPROCESSANDFEBACKTOINDUSTRY.FORWARDCOMMINTSREGARDINGBURDENESTIMATTOTHEINFORMATIONANDRECORDSMANAGEMENTBRANCHIT.SF33)US.NUCLEARREGIAATORYCOMMISSION.WASHINGTON.DC206664001ANDTOTHEPAPERWORKREDUCTIONPROJECT13160%1041,OFFICEOIMANAGEMENTANDBUDGET.WASHINGTON.DC20603.FACIUTYNAMEHiSTLUCIEUNIT1DOCKETNUMBER12105000335PAGE1311OF4TITLE(41InadvertantCoreAlterationProhibitedbyTechnicalSpecificationsDuetoStuckControlElementAssembly(CEA)MONTHDAY1027OPERATINGMODE(9)POWERLEVEL{10)97000SEQUENTIALREVISIONNUMBERNUMBER97-010-0020.2201(b)20.2203(0)(2)(I)20.2203(a)(2)(iii)20.2203(0)(2)(iv)MONTHOAY112620.2203{a)(2)(v)20.2203(a)(3)(ii)50.36(c)(1)50.36(c)(2)YEAR97FACILIlYNAMEFACILITYNAME50.73(a)(2)(i)50.73(a)(2)(iii)50.73(a)(2)(v)50.73(a)(2)(vii)DOCKETNUMBERDOCKETNUMBER50.73(a)(2)(viii)73.71OTHERSpecifyinAbstractbefoworinNRCForm366ANAMEJackRevell,LicensingEngineerTELEPHONENUMBERSncludeAreaCode)(561)467-7169CAUSESYSTEM.COMPONENTMANUFACTURERREPORTABLETONPRDSCAUSESYSTEMCOMPONENTMANUFACTURERREPORTABLETONPRDSACRCTC490XYES{Ifyes,completeEXPECTEDSUBMISSIONDATE).NoEXPECTEDSUBMISSIONDATE{15)MONTHOAYYEAR020498ABSTRACT(Limitto1400spaces,i.e.,approximately15single-spacedtypewrittenlines){16)OnOctober27,1997,St.LucieUnit1wasinMode6withthereactorheadremovedinpreparationfordefueling.Thecontainmentequipmenthatchandpersonnelaccessairlockwereopen,asallowedbyTechnicalSpecifications.PersonnelcommencedUpperGuideStructure(UGS)withdrawalfromthereactorvesselinaccordancewithprocedures.AstheUGSclearedthealignmentpins,aControlElementAssembly(CEA)wasdiscoveredattachedtotheUGS,andhadbeenunexpectedlywithdrawnfromthecore.ThisconstitutedacorealterationwithoutthecontainmentpenetrationstatusrequiredbyTechnicalSpecifications.Containmentintegritywassetwithinabout20minutesofdiscoveryofthestuckCEA.ThecauseoftheCEAremainingattachedtotheUGScouldnotimmediatelybedetermined.AsafetyevaluationwasperformedandaproceduralrevisionmadetocontinuetheUGSmove.Reactorcavitywaterlevelwasraisedtoincreaseshielding.Anticipatingelevatedcontainmentradiationlevels,theContainmentIsolationSystem(CIS)wasmanuallyactuatedpriortocontinuingthelift.TheUGSliftrecommencedonOctober28.AremotecamerasituatedbeneaththeUGSmonitoredtheprogress,andtheCEAremainedattachedthroughoutthetransit.Oncethetransittotherefuelingcavitywascompleted,theCEAwasrecoveredfromtheUGS.Therootcauseoftheeventisstillunderinvestigation.Furthercorrectiveactionswillbeidentifiedoncetherootcauseisdetermined.NRCFORM366(4-95)

NRCFORM366A(4.95)LICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIOSTLUCIEUNIT105000335YEARSEQUENTIALREVISION97-010-002OF4TEXTilfmorespeceisrequired,useeddnionelcopiesofNRCForm366A/I17IDESCRIPTIONOFTHEEVENTOnOctober27,1997,St.LucieUnit1wasinMode6withthereactorhead[EIIS:AB:RCT]removedinpreparationforreactordefueling.Thecontainmentequipmenthatchandpersonnelaccessairlock[EIIS:NH]wereopen,asallowedbyTechnicalSpecifications.ControlElementAssemblies(CEAs)[EIIS:AA]hadbeenunlatchedbypersonnelinaccordancewithprocedureOP1-0110022,'Coupling'andUncouplingofCEAExtensionShafts'.Atapproximately1510,thereactorcavitywaterlevelwasraisedto55feet6inchestomaintainadequateshieldinginpreparationforliftingtheUpperGuideStructure(UGS)[EIIS:AC].Normallyduringthelift,onlytheUGSliftrigisraisedabovethesurfaceofthewater.Atapproximately1658,contractpersonnelcommencedUGSwithdrawalfromthereactorvesselinaccordancewithprocedure1-M-0015,'ReactorVesselMaintenance-SequenceofOperations'.Duringtheevolution,acameramountedatthereactorvesselflangelevelwasusedtoverifyliftalignmentandclearance.Atapproximately1744,astheUGSclearedthealignmentpins,aCEAwasdiscoveredattachedtotheUGS,andhadbeenunexpectedlywithdrawnfromthecore.Operationsorderedcontainmentintegritytobeset,andthiswasachievedby1805.ThecauseoftheCEAremainingattachedtotheUGScouldnotimmediatelybedetermined.AsafetyevaluationwasperformedwhichconcludedthattherewouldbenoadverseimpactonplantsafetyoroperationshouldtheCEAfallontothecorewhilecompletingtheUGSmove.Procedure1-M-0015,'ReactorVesselMaintenance-SequenceofOperations',wasrevisedtoaccommodatemovementoftheUGSwithaCEAattached.SincetheUGSandliftrigweretobeliftedmuchhigherthannormal,reactorcavitywaterlevelwasadjustedto60feettoincreaseshielding.Thisactionwascompletedatapproximately2222hours.InanticipationofreceivinghighenoughcontainmentradiationlevelstoinitiateaContainmentIsolationActuationSignal(CIAS),unnecessarypersonnelleAcontainmentandtheContainmentIsolationSystem(CIS)[EIIS:JM]wasmanuallyactuatedatapproximately0253onOctober28.ThiswasapreplannedactuationperformedinaccordancewithprocedureOP1-1600023,'RefuelingSequencingGuidelines'.NACFOAM366AI4.95)

NRCFORM366AI4.96)LICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIOSTLUCIEUNIT105000335YEARSEQUENTIALREVISION97-010-003OF4TEXTflfmorespeceisrequired,useedditionelcopiesofNRCForm366A/I17)TheUGSliftrecommencedatapproximately0320withonlyessentialpersonnelincontainment.AremotecamerasituatedbeneaththeUGSmonitoredtheprogress,andtheCEAremainedfirmlyattachedthroughoutthetransit.Atapproximately0324,CIASchannelsindicatedthatcontainmentradiationlevelshadreachedtheCIASinitiationthreshold.ChannelMD,withthemostdirectexposuretotheUGS,registeredanarearadiationrateofapproximately7REMperhour,whiletheotherthreechannelsindicatedapproximately100milliremperhour.CISactuatesautomaticallywithtwochannelsgreaterthanorequalto90milliremperhour.Oncethetransittotherefuelingcavitywascompleted,attemptsweremadetofreetheCEAbutwereinitiallyunsuccessful.Subsequently,theCEAwasdisengagedbyoperatingpersonnel.TheCEAwasretrievedandmovedtothespentfuelpoolforstorage.ItwasidentifiedasCEA24,aType1,fulllengthCEAmanufacturedbyCombustionEngineering.CAUSEOFTHEEVENTThecauseoftheeventwasfailureoftheCEAtodetachfromtheUGS.ItiscurrentlyundeterminedwhethertheCEAwaspartiallylatchedorfrictionfittotheCEAExtensionShaft.Therootcauseisstillunderinvestigation.AsupplementtothisLERwillbeissueddescribingthefindingsofrootcauseevaluationforthestuckCEA.ANALYSISOFTHEEVENTThiseventisreportableunder10CFR50.73(a)(2)(i)(B)as"Anyoperationorconditionprohibitedbytheplant'sTechnicalSpecifications."TheTechnicalSpecificationviolatedisUnit1TechnicalSpecification3.9.4:"Thecontainmentpenetrationsshallbeinthefollowingstatus:a.Theequipmentdoorclosedandheldinplacebyaminimumoffourbolts,b.Aminimumofonedoorineachairlockisclosed,andC.Eachpenetrationprovidingdirectaccessfromthecontainmentatmospheretotheoutsideatmosphereshallbe...(severalconfigurationsgiven).APPLICABILITY:DuringCOREALTERATIONSormovementofirradiatedfuelwithinthecontainment."NRCFORM366AI4.96)

NRCFORM366AI4-95)LICENSEEEVENTREPORT(LER)TEXTCONTINUATIONU.S.NUCLEARREGULATORYCOMMISSIOSTLUCIEUNIT105000335YEARSEQUENTIALREVISION97-010-004OF4TEXTllfmorespaceisrequired,useadditionalcopiesofNRCForm366A/I17ITheTechnicalSpecificationsdefine"corealteration"as"movementormanipulationofanyfuel,sources,reactivitcontrolcomponents,orothercomponentsaffectingreactivitywithinthereactorvesselwiththevesselheadremovedandfuelinthevessel."Normally,liftingaUGSisnotacorealteration,sincetheUGSdoesnotcontainfuel,sources,orcomponentsthatcontroloraffectreactivity.However,sinceareactivitycontrolcomponent(aCEA)wasmovedwiththeUGSinthisevent,acorealterationwasperformed.Moreover,thecorealterationwasperformedwithoutthecontainmentpenetrationstatusrequiredbytheTechnicalSpecification.Penetrationswereplacedintherequiredstatewithinapproximately20minutesofdiscoveryofthestuckCEA.TheCISactuationwasnotreportableunder10CFR50.72,sincetheactuationwaspartofapreplannedsequenceaddressedbyprocedure.TheCISisdesignedtomitigatetheconsequencesofaccidentswhichreleaselargeamountsofenergywithinthecontainmentstructure.Therewasnosuchaccidentinthiscase,andtheCISactuationwasintentionalratherthantheresultofaccidentconditions.WithdrawalofthestuckCEAfromthereactorcoredidnotplacetheplantinanunanalyzedcondition,nordiditplacetheplantinaconditionoutsideitsdesignbasis.PlantproceduresaddressthecaseofasingleCEAnotinsertedinthecore,andsubstantialshutdownmarginwasmaintainedduringthecourseofthisevent.LER97-001-00forSt.LucieUnit2documentedaneventwithradiologicalconditionssimilartothisevent.IntheUnit2event,anexpectedCISactuationoccurredastheUGSwaswithdrawnfromthereactor.Theelevatedradiationlevelswerecausedbyirradiatedincoreinstrumentationsegments[EIIS:IG]whichhadbrokenduringremovalofincores.TheUnit2event,however,wasunlikethiseventinthattherewasnocorealteration.ICORRECTIVEACTIONSImmediatecorrectiveactionsincludedstoppingtheUGSliftandevaluatingdoserates.AconditionreportwasissuedandateamwasdesignatedtodeterminethecauseofthestuckCEA.Theteamreviewedpotentialfailuremodesandrelatedindustryexperience,buthasnothadaccesstotheCEA'sextensionshaftforevaluation.Theunlatchprocedurewasalsoreviewedandverifiedtohavebeenproperlyperformed.FurthercorrectiveactionsforthestuckCEAwillbeidentifiedinasupplementtothisLERoncetherootcausehasbeendetermined.NACFOAM366AI4.95)