ML17222A771

Special Rept:On 890315,diesel Tripped on High Crankcase Pressure.Caused by Engine Design.Pressure Trip Reset,But Output Breaker Failed to Close.Faulty Voltage Monitoring Relay Replaced.On 890321,same Diesel Generator Tripped

ML17222A771
Person / Time
Site:	Saint Lucie
Issue date:	04/27/1989
From:	CONWAY W F FLORIDA POWER & LIGHT CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
L-89-167, NUDOCS 8905010241
Download: ML17222A771 (5)

Text

,A.CCELERATEDDlllO'tDEMONSTRE'7SYSTEM(IKRECXPIENTIDCODE/NAMEPD2-2LANORRIS,JXNTERNAL:ACRSMICHELSONACRSWYLIEAEOD/DSP/TPABDEDRONRR/DEST/ADE8HNRR/DEST/CEB8HNRR/DEST/ICSB7NRR/DEST/MTB9HNRR/DEST/RSB8ENHR/DLPQ/HFB10NRR/DOEA/EAB11NR~RDRYSIB9AG'FILE02S/DSRRABCOPIESLTTRENCL11111111111111111111111111"11""-'111RECIPIENTIDCODE/NAMEPD2-2PDACRSMOELLERAEOD/DOAAEOD/ROAB/DSPIRM/DCTS/DABNRR/DEST/ADS7ENRR/DEST/ESB8DNRR/DEST/MEB9HNRR/DEST/PSB8DNRR/DESTJSGB8DNRR/DLPQ/QAB10NRR/DREP/RPB10NUDOCS-ABSTRACTRES/DSIR/EIBRGN2FILE01COPIESLTTRENCL112211221110111111111122111111REGULATORYINFORMATIONDISTRIBUTIONSYSTEM(RIDS)ACCESSIONNBR:8905010241DOC.DATE:89/04/27NOTARIZED:NOFACIL:50-389St.LuciePlant,Unit2,FloridaPower&LightCo.AUTH.NAMEAUTHORAFFILIATIONCONWAY,W.F.FloridaPower&LightCo.RECIP.NAMERECIPIENTAFFILIATIONDocumentControlBranch(DocumentControlDesk)

SUBJECT:

Specialrept:on890315&21,dieselgeneratorfailureoccurred.DISTRIBUTIONCODE:IE22DCOPIESRECEIVED:LTRENCLSIZETITLE:50.73/50.9LicenseeEventReport(LER),ncidentRpt,etc.NOTES:DOCKETI05000389DDDEXTERNAL:EG&GWILLIAMS,SLSTLOBBYWARDNRCPDRNSICMURPHY,G.A44111111FORDBLDGHOY,ALPDRNSICMAYS,G111111RIDShItRXDSIIRECXPIENISPIZASEHELPUS'IQREDUCE%ASTE!~CT~tXICUMEN7CONZROLDESK,RXNPl-37(EXT.20079)XOZXaIKQQZRKKRNMEFETCHDISTRZK)TIGNLISTSPDRDCICUMENZSYOUDON'TNEEDfDSTOTALNUMBEROFCOPIESREQUIRED:LTTR44ENCL43 P.O.Box14000,JunoBeach,FL33408-0420APRlL',71989L-89-167U.S.NuclearRegulatoryCommissionAttn:DocumentControlDeskWashington,D.C.20555Gentlemen:Re:St.LucieUnit2DocketNo.50-389DateofEvents:March15,1989andMarch21,1989SecialReortonDieselGeneratorFailuresTheattachedSpecialReportisbeingtransmittedpursuanttotherecpxirementsofTechnicalSpecification4.8.1.2.2toprovidenotificationof2BEmergencyDieselGeneratorfailures.Verytrulyyours,W.F.ConySeniorViePresident-NuclearWFC/JRH/cmAttachmentcc:StewartD.Ebneter,RegionalAdministrator,RegionII,USNRCSeniorResidentInspector,USNRC,St.LuciePlantg90g0102gl890427PDRADOCK05onFPLGroupcompany SPECIALREPORTDIESELGENERATORFAILURES2BDIESELGENERATORFAILURE:3/15/89InaccordancewithNRCReg.Guide1.108,sectionC.2.e,thise'ventisconsideredanon-validdieselgeneratorfailure,sinceitwascausedbya"malfunctionofequipmentthatisnotoperativeintheemergencyoperatingmode."However,inaccordancewithUnit2TechnicalSpecification4.8.1.2.2,thiseventisbeingsubmittedasaSpecialReport.At1109onMarch15,1989,the2Bdieselgeneratorwasstartedforamonthlysurveillancerun.The2Bdieseltrippedonhighcrankcasepressure.Thehighcrankcasepressuretripwasonthe12cylinderengine.Thistripsignalisbypassedbydesignwhenthedieselgeneratorisintheemergencymode.Thehighcrankcasepressuretripwasresetandthe2Bdieselwassuccessfullyrestartedforthesurveillance.Thecauseofthehighcrankcasepressuretripisinthedesignofthe12cylinderengine.Undercertainconditions,(e.g.,faststartsand/orlowerlubeoiltemperatures),thelubeoilreliefvalvewillrelievelubeoilincloseproximitytothecrankcasepressuredetector,thuscausingahighcrankcasepressuretrip.Thehighcrankcasepressuretripisnotoperativewhenthedieselgeneratorisintheemergencyoperatingmode;therefore,thisisconsideredanon-validfailure.Theimmediatecorrectiveactionstakenweretoresetthehighcrankcasepressuretripandcompletetherequiredsurveillanceforthe2BDieselGenerator.lnaddition,oilsplashguardswere.installedonboththe2Aand2B12cylinderengines.TheseactionswerecompletedbyMarch21,1989.Also,sincetherecentlyissuedAmendmentNo.39totheTechnicalSpecificationsallowsidlestarSs(450rpmvice900rpm),procedurechangesarebeingpreparedinordertoperformidledieselenginestartswhenthesoakbackoilsystemhasbeenoutofserviceforextendedperiods.Additionalinformation:a)Onevalidfailureinthelast100validtestsb)Thedieselwasoutofserviceforabriefperiodtoresetthehighcrankcasepressuretrip.c)Thecurrentsurveillanceintervalisonceevery31days.

SPECIALREPORTDIESELCENERATORFAILURESPageTwo2BDIESELCENERATORFAILURE:3/15/89InaccordancewithNRCReg.Cuide1.108,SectionC.2.e,thiseventisconsideredavaliddieselgeneratorfailuresincethiseventfallsunderthecategoryof"successfulstartsfollowedbyanunsuccessfulloadingattempt".Furthermore,inaccordancewithUnit2TechnicalSpecification4.8.1.2.2,theeventisbeingsubmittedasaSpecialReport.At1119onMarch15,1989,the2Bdieselgeneratorwassuccessfullyrestartedforthemonthlysurveillancerunafterresettingthehighcrankcasepressuretripfromthepreviousstartattempt.Thedieselgeneratoroutputbreakerwouldnotclose.The2Bdieselgeneratorwassecuredanddeclaredoutofservice.ThefailureofthedieselgeneratoroutputbreakertoclosewasduetoafaultyVoltageMonitoringRelay(VMR)intheDieselCeneratorControlPanel.TheVMRisoneofthepermissivecontactsthathastobemadeupbeforetheoutputbreakercanbeclosed.Thisrelaypreventedloadingofthedieselgenerator.ThiseventwasdeterminedtobeavalidfailureinaccordancewithReg.Cuide1.108,SectionC.2.e.CorrectiveactionstakenwerethereplacementoftheVoltageMonitoringRelayandcompletionoftherequiredsurveillancetoreturnthedieselbacktoservice.Additionalinformation:a)ThisfailureisthesecondvalidfailureinthelastI00validtests.b)Thedieselwasoutofserviceforthiseventfor8hrs.and12min.c)Thecurrentsurveillanceintervalisonceevery31days.

SPECIALREPORTDIESELGENERATORFAILURESPageThree2BDIESELGENERATORFAILURE:3/21/89InaccordancewithNRCReg.Guide1.108,SectionC.2.e,thiseventisconsideredanon-validdieselgeneratorfailure,sinceitwascausedbya"malfunctionofequipmentthatisnotoperativeintheemergencyoperatingmode."However,inaccordancewithUnit2TechnicalSpecification4.8.1.2.2,thiseventisbeingsubmittedasaSpecialReport.At0729onMarch21,1989,the2BdieselgeneratorautomaticallystartedduetotheinadvertentactuationoftheContainmentIsolationActuationSignal(seeLER389-89-003).WhentheContainmentIsolationActuationSignalwasreset,the2Bdieselgeneratortrippedonhighcrankcasepressure.Thiseventoccurredpriortotheinstallationoftheoilsplashguardonthe2Bdieselgenerator.The2Bdieselgeneratorwasplacedoutofservicetocorrecttheproblem.Thecauseofthehighcrankcasepressuretripisinthedesignofthe12cylinderengine.Undercertainconditions,(e.g.,faststartsand/orlowerlubeoiltemperatures),thelubeoilreliefvalvewillrelievelubeoilincloseproximitytothe'crankcasepressuredetector,thuscausingahighcrankcasepressuretrip.Thehighcrankcasepressuretripisnotoperativewhenthedieselgeneratorisintheemergencyoperatingmode;therefore,thisisconsideredanon-validfailure.Correctiveactionstakenweretheinstallationofoilsplashguardsonthe2Aand2B12cylinderengines.Also,sincetherecentlyissuedAmendmentNo.39totheTechnicalSpecification-allowsidlestarts(450rpm'ice900rpm),procedurechangesarebeingpreparedinordertoperformidledieselenginestartswhenthesoakbackoilsystemhasbeenoutofserviceforextendedperiods.Additionalinformation:a)Twovalidfailuresinthelast100validtestsb)Thedieselwasoutofserviceforthiseventfor5hrs.and55min.c)Thecurrentsurveillanceintervalisonceevery31days.