ML17223B393

Special Rept:On 911129,emergency Diesel Generator 1B Started for Weekly Operational Check & Output Voltage Climbed Above Nominal Voltage.Caused by Failed Component in Voltage Regulator Card.Regulator Card Replaced

ML17223B393
Person / Time
Site:	Saint Lucie
Issue date:	12/20/1991
From:	SAGER D A FLORIDA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
L-91-346, NUDOCS 9201020058
Download: ML17223B393 (3)

Text

ACCELERATEDDISTRIBREGULATORYINFORMATIONDISTRIBUTIONSYSTEM(RIDS)DOCKET05000335NOTES:ACCESSIONNBR:9201020058DOC.DATE:91/12/20NOTARIZED:NOFACIL:50-335St.LuciePlant,Unit1,FloridaPower&LightCo.AUTH.NAMEAUTHORAFFILIATIONSAGER,D.A.FloridaPower&LightCo.RECIP.NAMERECIPIENTAFFILIATIONDocumentControlBranch"(DocumentControl'Desk)

SUBJECT:

Specialrept:on911129,emergencydieselgenerator1Bstartedforweeklyoperationalcheck&outputvoltagecl'imbedabovenominalvoltage.Causedbyfailedcomponentznvoltageregulatorcard.Regulatorcardreplaced.DISTRIBUTIONCODE:IE22DCOPIESRECEIVED:LTRENCLSIZE:TITLE:50.73/50.9LicenseeEventReport(LER),IncidentRpt,etc.RECIPIENTIDCODE/NAMEPD2-2LANORRIS,JINTERNAL:ACNWAEOD/DOAAEOD/ROAB/DSPNRR/DET/EMEB7ENRR/DLPQ/LPEB10NRR/DREP/PRPB11NRR/DST/SICB8H3NRR/DST/SRXB8ERES/DSIR/EIBEXTERNAL:EG&GBRYCE,Z.HNRCPDRNSICPOOREIW~COPIESLTTRENCL1111221122111122111111331111RECIPIENTIDCODE/NAMEPD2-2PDACRSAEOD/DSP/TPABNRR/DET/ECMB9HNRR/DLPQ/LHFB10NRR/DOEA/OEABNRR/DST/SELB8DNRR/DSX/SQLBSDlRQG~FIGE~RG=-PIC01LSTLOBBYWARDNSICMURPHY,G.ANUDOCSFULLTXTCOPIESLTTRENCL11221111111111111111111111NOTETOALL"RIDS"RECIPIENTS:PLEASEHELPUSTOREDUCEiVASTE!CONTACTTHEDOCUMENTCONTROLDESK,ROO'klPl-37(EXT.20079)TOELlbIFNATEYOURNANCEFROMDISTRIBUTIONLISTSFORDOCUAIENTSYOUDOiN'TNEED!TOTALNUMBEROFCOPIESREQUIRED:LTTR33ENCL33 P.O.Box1.Pierce,FL34954-0128December20,1991L-91-34610CFR50.36U.SNuclearRegulatoryCommissionAttn:DocumentControlDeskWashington,DC20555Gentlemen:Re:St.LucieUnit1DocketNo.50-335SpecialReportDateofEvent:November29,1991EmerencDieselGeneratorFailureTheattachedSpecialReportisbeingtransmittedpursuanttotherequirementsofSt.LucieUnit1TechnicalSpecifications4.8.1.2.2and6.9.2..Thereportprovidesnotificationofa1BEmergencyDieselGeneratorfailureduringtheweeklyoperationalcheck.Shouldtherebeanyquestionsonthisinformation,pleasecontactus~Verytrulyyours,D.A.VicePSt'geresidentiePlantDAS/JWH/kwAttachmentcc:StewartD.Ebneter,RegionalAdministrator,RegionII,USNRCSeniorResidentInspector,USNRC,St.LuciePlantDAS/PSL0588-91P""A'j02VO~i8<s.',0rj.lrlanFPLGroupcon>panyy/P)

NRCSPECIALREPRTDIESELGENERATORVALIDFAILUREOn29November1991at1101theSt.LucieUnitOne1BEmesgencyDieselGenerator(EDG)wasstartedfortheweeklyoperationalcheck.Operationsnotedthatupongenerator'excitationthe'outputvoltagecontinuedtoclimbabovenominalvoltage.The1BEDGwasshutdownat1105anddeclaredoutofservice.The-1BEDGwasrestartedforcontinued.troubleshooting.Theproblemwasrepeatedforfurthertroubleshootingandthe1BEDGwasshutdownat1649.St.LucieUnitOnewasinarefuelingshutdownandthe1BEDGwasnotrequiredtobeinserviceperTechnicalSpecification3.8.1.2.Theproblemwastracedtothevoltageregulatorcircuit.Thefailedcomponentwastheautovoltageregulatorcard.Thevoltageregulatorcircuitisdesignedtoproducehighgeneratorvoltageintheeventofamalfunctionofthevoltageregulatorcircuit.CorrectiveActions:Theautovoltageregulatorcardwasreplacedandat1817thedieselgeneratorwassuccessfullystarted.Thegeneratoroutputvoltagecontrollednormally.Afterperformingtheoperationalcheckthe1BEDGwasdeclaredbackinserviceat1824.The1BEDGwasunavailableforsevenhoursandnineteenminutes.FailureSummary:Thisisthethirdvalidfailureofthe1BEDGintheprevious20validtests.The1BEDGhasaccumulated22validtestssincetheimplementationoftheTechnicalSpecification3.8.1.1(July,1990).ThecurrentsurveillanceintervalisoncepersevendaysperTechnicalSpecification4.8.1.2.2.