ML17228B368

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Responds to Violations Noted in Insp Repts 50-335/95-20 & 50-389/95-20.Corrective Actions:Multidiscipline Team Established to Perform Comprehensive Review of Nuclear safety-related Relief Valve Lift & Blowdown Settings
ML17228B368
Person / Time
Site: Saint Lucie  NextEra Energy icon.png
Issue date: 12/19/1995
From: GOLDBERG J H
FLORIDA POWER & LIGHT CO.
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
L-95-333, NUDOCS 9512260055
Download: ML17228B368 (7)


See also: IR 05000335/1995020

Text

LXAMAXEA(ACCELERATEDRIDSPROCESSIiCREGULATORYINFORMATIONDISTRIBUTIONSYSTEM(RIDS)CESSIONNBR:9512260055DOC.DATE:95/12/19NOTARIZED:NOFACIL:50-335St.LuciePlant,Unit1,FloridaPower&LightCo.50-389St.LuciePlant,Unit2,FloridaPower&LightCo.AUTH.NAMEAUTHORAFFILIATIONGOLDBERG,J.H.FloridaPower&LightCo.RECIP.NAMERECIPIENTAFFILIATIONDocumentControlBranch(DocumentControlDesk)SUBJECT:Respondstoviolationsnotedininsprepts50-335/95-2050-389/95-20.Correctiveactions:multidisciplineteamestablishedtoperformcomprehensivereviewofnuclearsafety-relatedreliefvalvelift&blowdownsettings.DISTRIEDTIONCODE:IEOIDCOPIESRECEIVED:LTRIENCLgSIZE:TITLE:General(50Dkt)-InspRept/NoticeofVioTationResponseNOTES:DOCKET0500033505000389RECIPIENTIDCODE/NAMEPD2-1PDINTERNAL:ACRSAEOD/SPD/RABDEDRONRR/DISP/PIPBNRR/DRPM/PECBNUDOCS-ABSTRACTOGC/HDS3EXTERNAL:LITCOBRYCE,JH'RCPDRCOPIESLTTRENCL11221111111111111111RECIPIENTIDCODE/NAMENORRIS,JAEOD/DEIBAEOTCLECERNCTP/HHFBNRR/DRPM/PERBOEDIRRGN2FILE01NOACCOPIESLTTRENCL111111111111111111VOTETOALL"RIDS"RECIPIEY'TS:PLEASEHELPUSTOREDUCEiVASTE!COYTACTTHEDOCL'ifEYTCOYTROLDESK.ROOMPl-37(EXT.504.2083)TOELIXIIiATE5'OI.'RiAiIEFROilDISTRIBUTIOYLISTSI'ORDOCI.'MEi'I'SYOUDOi"I'ELIDIOTALNUMBEROFCOPIESREQUIRED:LTTR20ENCL20

FloridaPower5LightCompany,P.O.Box128,FortPierce,FL34954-0128FPLDEC191995L-95-33310CFR2.201U.S.NuclearRegulatoryCommissionAttn:DocumentControlDeskWashington,D.'.20555Re:St.LucieUnits1and2DocketNo.50-335and50-389ReplytoNoticeofViolationIninR-2-EA-222FloridaPowerandLightCompany(FPL)hasreviewedthesubject,noticeofviolationissuedonNovember28,1995.Pursuantto10CFR2.201,theresponseisattached.OnDecember1,1995,theNRCseniorresidentinspectorforSt.LucienotifiedFPLthattheresponsetothisnoticeofviolationwasnotrequiredtobesubmittedunderoathoraffirmationasoriginallyrequested'bythenoticeofviolation.Verytrulyyours,J.H.oldbergPresident-NuclearDivisionJHG/GRMAttachmentcc:StewartD.Ebneter,RegionalAdministrator,USNRCRegionIISeniorResidentInspector,USNRC,St.LuciePlantQf>P;~rVit~r9512260055951219PDRADDCK050003359PDRanFPLGroupcompany

Re:St.LucieUnits1and2DocketNo.50-335and50-389ReplytoNoticeofViolationInsecinRe-20ViolationEA5-22210CFR50,AppendixB,CriterionXVI,"CorrectiveActions,"requires,inpart,thatmeasuresbeestablishedtoassurethatconditionsadversetoqualityarepromptlyidentifiedandcorrected.Contrarytotheabove,conditionsadversetoquality,involvingreliefvalvesetpointandblowdownvalues,identifiedonFebruary20,March2,andMarch10,1995,didnotreceivepromptcorrectiveactionsandledtoarepeatofpreviouslyidentifiedproblemsonAugust10,1995,whenUnit1reliefvalveV-3439liftedandfailedtoreseatwithoutoperatorintervention.Thesubjecteventresultedinapproximately4000gallonsofreactorcoolantaccumulatingintheUnit1pipetunnel.Evaluationsperformedafterthiseventrevealedtheneedtoreplace,orestablishnewsetpointsfor,severalreliefvalvesinsafetysystemsinbothunits.ThisisaSeverityLevelIVviolation(SupplementI).FPLRne1.Thereasonfortheviolation:Theseriesofreliefvalveeventsthatoccurredinearly1995tookplaceindifferentplantsystemsandinvolvedbothSt.LucieUnit1andUnit2.Initialplanteffortstocorrecttheseindividualplanteventswerefocusedonsolvingtheplantsystemcontrolproblemsthatledtothepressuretransientscausingtheseriesofreliefvalveactuation.Briefly,theseeventsarediscussedbelow:ThecausesoftheUnit1andUnit2letdownevents(betweenJanuary23,1995andJuly8,1995)wereassociatedwithletdownpressurecontrolproblems.Thecorrectiveactionswerefocusedontheletdownpressurecontrolvalveperformance.ThecauseoftheUnit2componentcoolingwaterreliefvalveactuationevent(February17,1995)wasatestconfigurationproblem.AtthetimeoftheNRCinspectionforthesubjectinspectionreport,asystemtransienttestwasbeingdevelopedtoevaluatetheconfigurationproblem.

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ThecauseoftheUnit1shutdowncoolingsuctionreliefevent(February27,1995)wasaflowinitiatedpressuretransient.Thecorrectiveactionwastheimplementationofaprocedurechangewhichmitigatesthepotentialforpressuretransientswhileplacingshutdowncoolinginservice.Longtermcorrectiveactionsarediscussedinparagraph2.D.ThecauseoftheUnit1shutdowncoolingdischargerelief(V3439)event(August10,1995)wasidentifiedasadesignliftandblowdownsetpointproblem.Oncetherelieflifted,itdidnotreseatwithoutoperatorinterventiontoisolatetheaffectedportionofthesystem.ThecorrectiveactionsweretoreplacethevalveV3439andtoincreasethereliefvalveliftsetpointandtoreducetheblowdownsettingtherebyprovidingadditionaloperatingmargin.Theseindividualeventsdidnotappeartoshareacommonrootcauseandcorrectiveactionstoresolvetheseindividualproblemswerepromptlyinitiatedbyplantmanagement.AgenericreliefvalvesetpointconcernwasidentifiedbytheOperationsSupervisoronMarch2,1995(followingtheFebruary27,1995event),andwasassignedtoMechanicalMaintenanceforresolution.BetweenMarchandAugustof1995,Maintenancefocusedondevelopingthreecorrectiveactions:1)anewreliefvalvetestbench,2)revisionstovalvetestprocedures,and3)improvedmaintenancetraining.Maintenancehadnotconsideredadesignproblemwithreliefvalvesetpointsand,therefore,effortsweredirectedtowardverifyingthatthereliefvalvescouldbesetinaccordancewithplantdesign.Theunderlyingrootcausefortheseriesofreliefvalveevents-lackofdesignintegrationbetweensystemoperatingpressuresandreliefvalvereseatpressures-wasnotevidentuntiltheSt.LucieUnit1shutdowncoolingdischargereliefevent(August10,1995).Atthattime,theEngineeringDepartmentestablishedamulti-disciplinedteamtoinvestigatesafety-relatedreliefvalveliftandreseatsettings.TheSt.LucieActionRequest(STAR)processwasacontributingfactortothedelayinfindingtheunderlyingrootcauseoftheevents.TheSTARprocessreliedonseriesassignmentsforactionsanddidnotlenditselftoparallelinvestigationsorcorrectiveactions.Thecorrectivestepsthathaveorwillbetakenandtheresultsachieved:A.ThecorrectiveactionstakentoaddressthespecificproblemofsafetyrelatedreliefvalveliftandblowdownsettingsandcontrolofreliefvalvedesigninformationwereprovidedintheUnit1LicenseeEventReport(LED)95-06,andatthepre-decisionalenforcementconferenceonNovember14,1995.

B.InAugust1995,amulti-disciplineteamwasestablishedtoperformacomprehensivereviewoftheSt.LucieUnit1andUnit2nuclearsafetyrelatedreliefvalveliftandblowdownsettings.TheteamwascomposedofpersonnelfromMaintenance,Operations,PlantSystemEcComponentEngineering,andNuclearEngineering.Atotalof114reliefvalveswerereviewed(53forUnit1and61forUnit2)andtheirdesignsettingswereevaluatedrelativetosystemoperatingandtransientpressures.Seventeenofthesevalvesrequiredadditionalanalysis.Correctiveactions,exceptasnotedin2.Dbelow,havebeentakentoincreasethemarginbetweensystemoperatingpressuresandthelift/reseatsetting,whereappropriate.C.Unit1reliefvalvemodifications,withtheexceptionoftheshutdowncoolingsuctionoverpressurereliefvalves,V3468andV3483,wereimplementedpriortotheOctober1995startup,followingtheshutdownrelatedtoHurricaneErin.D.Unit1shutdowncoolingsuctionoverpressurereliefvalves,V3468andV3483,liftsettingswereadjustedtoimprovetheliftmarginpriortotheOctober1995startup.Withtheserevisedliftsettings,shutdowncoolingcanbeinitiatedwithoutchallengingthesereliefvalves.TheliftandblowdownsettingswillbefurthermodifiedduringtheSpring1996refuelingoutage.E.Unit2reliefvalvemodificationswereimplementedduringtheFall1995refuelingoutage.3.Thecorrectivestepstakenorplannedtoavoidfurtherviolations:~A.FPLMaintenanceSpecificationSPEC-M-038,SafetyRelatedReliefValveSetpointsSt.LucieUnits1and2,wasissuedinNovember1995toinstitutionalizetheresultsofthereliefvalvedesignreviewteam.B.TheSTARprocesswasmodifiedtofacilitateparalleldepartmentassignmentsfortheevaluationandcorrectionofdeficiencies.4.Thedatewhenfullcompliancewillbeachieved:A.TheSTARprocessprocedurewasmodifiedinOctober1995.B.FullcomplianceforthereliefvalvesettingswillbeachievedduringtheSpring1996refuelingoutage.