ML17292A336

From kanterella
Revision as of 20:37, 5 July 2018 by StriderTol (talk | contribs) (Created page by program invented by StriderTol)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to navigation Jump to search
LER 96-002-00:on 960504,critical Bus SM-8 Lost Power When Supply Breaker 3-8 Tripped.Caused by Personnel Error. Operators Counselled & Procedures revised.W/960620 Ltr
ML17292A336
Person / Time
Site: Columbia Energy Northwest icon.png
Issue date: 06/20/1996
From: BEMIS P R, PFITZER B
WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
GO2-96-124, LER-96-002, LER-96-2, NUDOCS 9606260184
Download: ML17292A336 (8)


Text

CATEGORYREGULATORY INFORMATION DISTRIBUTION SYSTEM(RIDS)ACCESSIOH NBR:9606260184 DOC.DATE:

96/06/20NOTARIZED:

NODOCKETFACIL:50-397 WPPSSNuclearProject,Unit2,Washington PublicPowe05000397AUTH.NAMEAUTHORAFFILIATION PFITZER,B.

Washington PublicPowerSupplySystemBEMIS,P.R.

Washington PublicPowerSupplySystemRECIP.NAME RECIPIENT AFFILIATION

SUBJECT:

LER96-002-00:on 960504,critical busSM-8lostpowerwhenSupplybreaker3-8tripped.Causedbypersonnel error.Operators counselled sprocedures revised.W/960620 ltr.DISTRIBUTION CODE:IE22TCOPIESRECEIVED:LTR IENCL(SIEE:5TITLE:50.73/50.9 LicenseeEventReport(LER),IncidentRpt,etc.NOTES:TEINTERNAL:

RECIPIENT IDCODE/NAME PD4-2PDACRSAEOD/SPD/RRAB NRR/DE/ECGB NRR/DE/EMEB NRR/DRCH/HICB NRR/DRCH/HQMB NRR/DSSA/SPLB RES/DSIR/EIB COPIESLTTRENCL111111111111111111RECIPIENT IDCODE/NAME COLBURN,T AEODDABECTERR~~BNRR/DRCH/HHFB NRR/DRCH/HOLB NRR/DRPM/PECB NRR/DSSA/SRXB RGN4FILE01COPIESLTTRENCL112211111~11~111111RDEXTERNAL:

LSTLOBBYWARDNOACMURPHY,G.A NRCPDR111111LITCOBRYCE,JHNOACPOOREEW.NUDOCSFULLTXT221111MNNOTETOALL"RIDS"RECIPIENTS:

PLEASEHELPUSTOREDUCEWASTE!CONTACTTHEDOCUMENTCONTROLDESK,ROOMOWFN5D-5(EXT.

415-2083)

TOELIMINATE YOURNAMEFROMDISTRIBUTION LISTSFORDOCUMENTS YOUDON'TNEED'.FULLTEXTCONVERSION REQUIREDTOTALNUMBEROFCOPIESREQUIRED:

LTTR26ENCL26 WASHI.'iGTO.'v PUBLICPOWERSUPPLYSYSTEMPO.Box968~3000George11rrshirrgton 11'ar~Richland, 11raslrington 99352-0968

~(509)372-5000June20,1996G02-96-124 DocketNo.50-397DocumentControlDeskU.S.NuclearRegulatory Commission Washington, D.C.20555Gentlemen:

Subject:

NUCLEARPLANTWNP-2,OPERATING LICENSENPF-21,VOLUNTARY LICENSEEEVENTREPORTNO.96-002-00 Transmitted herewithisvoluntary LicenseeEventReportNo.96-002-00 forWNP-2.Thiseventisnotreportable under10CFR50.72 or10CFR50.73.

Thisreportissubmitted voluntarily forinformation.

Shouldyouhaveanyquestions ordesireadditional information regarding thismatter,pleasecallmeorMs.LourdesFernandez at(509)377-4147.

Restfully,P.RBemis(MailDropPE20)VicePresident, NuclearOperations Enclosure cc:LJCallan,NRCRIVTGColburn,NRRKEPerkins,Jr.,NRCRIV,WCFONSReynolds, Winston&StrawnNRCSr.ResidentInspector, MD927N(2)INPORecordsCenter-Atlanta,GADLWilliams, BPA,MD3999606260i84 960620PDRADOCK050003978PDR 0

LICENSEEEVENTREPORT(LER)TACAITVNAME(IIWashington NuclearPlant-Unit2DocxETMA(TER(I(050003971(4TITLE(e(INADVERTENT LOSSOFPOWERTOCRITICALBUSANDEDGSTARTDUETOCLEARANCE ORDERRESTORATION ACTIVITY(ERNVMSER(el0IIRRTACAITKSe(VOLV(DeeDOCKET(ARISTA(et 0504969600200062096N/A05000500OtERATSICMODE(SItOWERLEV(L(I(e*(20.402(b)

(20.405(s)(l)(i) 20.405(s)

(1)(ii)Q0Q(20.405(e)(l)(iii)

I20.405(s)(l)(iv) 20.405(s)(1)(v)

(20.405c((50.36(c)(l)

)50.36(c)(2)

)(50.73(s)(2)(i)

)(50.73(s)(2)(ii)

II50.73(s)(2)(NI)

Uc(NTEECONTACTSORTiesLERIIt(UeeR(PORTISSUOMI(TEO tVRSVANTTOTHEREOUIR(MENTS Oc'loCIR:IIII(50.73(e)(2)(iv)

)50.73(s)(2)(v)

(50.73(e)(2)(vrl)

)50.73(e)(2)(vii)A 50.73(s)(2)(viii)

B)50.73(SH2)(x)

II73.71(b))73.71(c)(X(OTHER(Specify(nAbstrectbe(owendinText,NRCForm366A)I(((tIIONE NUMI(RBillPfitzer,Licensing EngineerCOMt(ETEOtCLSCIOREACHCOMt(HANT TALVREDESCRR(DINTITSR(toRT((el509377-2419MAIREAD.TURLRR(toRTAS(E TOMVDSMAIREAD.TVR(RR(PORTA(LE TOMV(DSSVttLEMENTAL REtoelEXTEC(m((4(YES(i)yes,completeEXPECTEDSUBM(SSION DATE)ABSTRACI')6)

(X(koEXPECTEDSUBMISSION DATE(15)OnMay4,1996at0142,withthereactordefueled, criticalbusSM-8lostpowerwhensupplybreaker3-8tripped.Asaresult,emergency dieselgenerator (EDG)2autostartedandthebackuptransformer automatically providedpowertoSM-8.Detailedinvestigation intothiseventdetermined thecausetobeaccidental openingofthenon-critical busSM-3potential transformer (PT)fusecompartment byanequipment operator(EO)performing restoration activities foraclearance order.Eventnotification wasmadetotheNRCpursuanttotherequirements of10CFR50.72(b)(2) asanEngineered SafetyFeature(ESF)actuation.

Thisnotification wassubsequently retracted afteradetailedreviewoftheeventandtheactuatedequipment.

TheWNP-2FSARdoesnotspecifytheEDGsasanEngineered SafetyFeature.ThisLERissubmitted onavoluntary basis.*-Defueled LICENSEVENTREPORT(LER)TEXTCOINUATlONTEXT(17)Washington NuclearPlant-Unit20500039796stovcMlalstvMMst002002"4EvenDecriinOnMay4,1996at0142,withthereactordefueled, thecontrolroomreceivedalarmsindicating anundervoltage condition onnon-critical bus[BU]SM-3.Breaker[BKR]3-8trippedduetotheundervoltage condition causingalossofpowertocriticalbusSM-8.Asaresult,EDG-2[DG]autostarted,thebackuptransformer

[XFMR]automatically providedpowertotheSM-8bus,andresidualheatremovalpump2B(RHR-P-2B)

[BO,P],whichwasoperating inthefuelpoolcooling[DA]assistmode,experienced atemporary lossofpower.Plantrestoration activities werecompleted atapproximately 0306.Immediate orrective ActionImmediately aftertheincident, Operations management suspended ongoingclearance orderrestoration activities andsecuredtheareaaroundtheSM-3auxiliary electrical cubicletosupportinvestigation activities.

AProblemEvaluation Request(PER)wasinitiated.

RHR-P-2Bwasreturnedtoserviceinthefuelpoolcoolingassistmodeafterapproximately 45minutes.Plantelectrical lineupandequipment restoration wascompleted atapproximately 0306.FurtherEvaluaionDuringtheIncidentReviewBoard(IRB)investigation, theEOreportedthathehadopenedandclosedthedooroftheSM-3auxiliary electrical cubicleinpreparation forrestoration ofaclearance orderassociated withtransformer TR-S.TheEOstatedthatafterlookinginsidethecubicleheshutthedoorandthenheardrelayschatter.Hespeculated hehadjarredtherelayswhileclosingthecabinetdoor.Eventevaluation, including furtherinterviews oftheEOinvolved, determined thefollowing:

~Momentary openingoftheSM-3busPTfusecompartment, whichisa~d'scent tothecompartment specified bytheclearance, wouldhavecausedalltheautoactionswhichoccurredduringthisevent.Bothfusecompartments arelocatedinsidetheSM-3auxiliary electrical cubiclewhichmustbeopenedtoviewthecompartments.

Thecompartment doorsutilizeaprotective featurewhichdisconnects thefusesasthecompartment doorisopened.

LICENSEEEVENTREPORT(LER)TEXTCONTINUATION SfQUCMNlNUMSOIRKVISKIHHUMORTEXT(l7)Washington NuclearPlant-Unit20500039796002003oF4ThedoorlatchfortheSM-3busPTfusecompartment wasfoundinthe11:30(justclosed)positionratherthanthe9:00(fullyclosed)positionasexpected.

PTfusedisconnects ofthistypecanbeeasilyopenedandre-closed inapproximately 1-2seconds.~Thecontrolroomalarmprinter"SM-3UNDERVOLTAGE" indication tookabout2secondstoreturntonormal.~Inanefforttoreproduce aninadvertent relayoperation, theSM-3auxiliary electrical cubicledoorwasrepeatedly slammed.Nooperation ofSM-3undervoltage relaysduetomechanical jarringorbumpingwasobserved.

~ThemaximumlengthoftimeforanHFAundervoltage relaytotripandreturntonormalduetomechanical jarringorbumpingisapproximately 40to50milliseconds.

Inthiscase,therelaywhichmustactuateaftertheundervoltage relaytoeffectopeningofbreaker3-8requirestheundervoltage signaltobeapproximately 1.0secondinduration.

ThephysicalevidencelistedaboveledtheIRBtopostulate threepossiblecausesfortheSM-3undervoltagb condition.

Thesepotential causeswere:~SlammingtheSM-3auxiliary electrical cubicledoorwhichjarredtheundervoltage relaysofSM-3causingbreaker3-8totrip.~DirtycontactsontheSM-3busPTfusestabswhichcausedpoorcontact,anundervoltage condition andtrippingofbreaker3-8.~OpeningoftheSM-3busPTfusecompartment whichcausedanundervoltage condition andtrippingofbreaker3-8.Aftercarefulconsideration, Operations management concluded thecauseoftheeventwasmomentary openingoftheSM-3busPTfusecompartment bytheEO.Itwasfurtherconcluded thattheEOoperatedtheSM-3busPTfusecompartment and,uponrealizing hiserror,hastilyreclosedthePTcompartment leavingthecompartment intheabnormalcondition foundbytheIRBinvestigators.

Thisconclusion isfurthersupported bytheinformation recordedonthecontrolroomalarmprinterandtheinformation obtainedduringtestingofthecomponents involved.

ThisLERissubmitted onavoluntary basis.

0 LICENSEVENTREPORT(LER)TEXTCOINUATIONTEXTu7)Washington NuclearPlant-Unit20500039796SfOUCMtNL

~MA002ROI5ONNVM80l004o"4RootaueTherootcauseforthiseventispersonnel error.TheSM-3busPTfusecompartment wasinadvertently opened,causinganSM-3undervoltage signal.Acontributing causewasinadequate pre-jobbrief.TheProduction ReactorOperator(RO)andSeniorReactorOperator(SRO)didnotaddressthepotential adverseconsequences ofoperation ofthebusPTfusecompartment.

Anadditional contributing causewasfailuretofollowtheprocedure requirements toidentifyclearance orderstepsforPTfuserestoration asrequiring simultaneous verification.

Furtherorrective ActionPersonnel actionappropriate tothecircumstances wastakenwiththeEO.TheProduction ROandSROwerecounseled concerning thenecessity ofperforming adequatepre-jobbriefspriortoperformance ofcriticalclearance activities.

Theprocedures/instructions governing clearance orderpreparation willberevisedtoensuretheneedforsimultaneous verification isnotedontherequiredclearance ordersteps.Assessment ffeConseuenceThesafetyconsequences ofthiseventareminimal.Thereactorwasdefueledatthetimethiseventoccurred.

Expectedautomatic actionsoccurredincluding autostartingofEDG-2andre-energization ofSM-8fromthebackuptransformer.

RHR-P-2B, whichwasoperating inthefuelpoolcoolingassistmode,trippedasaresultofthelossofpowerbutwasrestoredafterapproximately 45minutes.Estimated timetoboilatthetimeofthiseventwas52hours.PreviousSimilarEventsPreviousLERsdocumenting personnel errorresulting inactuation ofsafety-related equipment areasfollows:LER96-001involvedinadvertent ESFactuations duetotrippingofatemporary powersupplytoIN-3byoutageelectricians.

LER95-002involvedOperations personnel operating thewrongleverduringamainturbinetestresulting inturbinetripandreactorscram.