ML17326A065

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LER 98-014-03:on 980310,noted That Response to high-high Containment Pressure Procedure Was Not Consistent with Analysis of Record.Caused by Inadequate Interface with W. FRZ-1 Will Be Revised to Be Consistent with New Analysis
ML17326A065
Person / Time
Site: Cook American Electric Power icon.png
Issue date: 07/22/1999
From: DEPUYDT M B
INDIANA MICHIGAN POWER CO.
To:
Shared Package
ML17326A064 List:
References
LER-98-014, NUDOCS 9907280079
Download: ML17326A065 (3)


Text

NRCForm366U.S.NUCLEARREGULATORY COMMISSION (6-1996)LICENSEEEVENTREPORT(LER)(Seereverseforrequirednumberofdigits/characters foreachblock)APPROVED8YOM8NO.3160%104EXPIRES06/30/2001 ESTBIATED BURDENPERRESPONSETOCOMPLYWITHTHISMANDA'tORY INFORMATION COLLECTION REQUEST:500HRS.REPORTEDLESSONSLEARNEDAREINCORPORATED INTOTHEUCENSUIQPROCESSANDFEDBACKTOINDUStRY.

FORWARDCOLTJENTS REQARINNQ BURDENESTUJATETOTHEINFORMATION ANDRECORDSMANAGEMENT BRANCHrt+F33),U.S.NUCLEARREGULATORY COLBBSSION, WASHINGTON.

DC205554001.

ANDTOTHEPAPERWORK REDUCTION PROJECTI3150oterx OFFICEOFMANAGEMENT ANDBUDGEt.WASHINGTON.

DC20503FACIUTYNAMEII)TITLEI4)CookNuclearPlantUnit1DOCKETNUMBERI2)05000-315 PAGEI3)1of3"Response toHigh-High Containment Pressure" Procedure NotConsistent withAnalysisofRecordEVENTDATE(6)LERNUMBER(6)REPORTDATE(7)OTHERFACILITIES INVOLVED(6)MONTHDAYYEARYEARSEQUENTIAL NUMBERREVISIONNUMBERMONTHDAYFACIUTYNAMDCCook-Unit2DOCKETNUMBER05000-316 0310981998-014-0307221999ACIUNAMDOCKETNUMBOPERATING MODE(9)POWERLEVEL(10)0020.2201(b)20.2203(a)(1) 20.2203(a)(2)(l) 20.2203(a)(2)(v) 20.2203(a)(3)(i) 20.2203(a)(3)(ii) 50.73(a)(2)(i) 50.73(a)(2)(li) 50.73(a)(2)(iii) 50.73(a)(2)(viii) 50.73(a)(2)(x) 73.71THISREPORTISSUBMITTED PURSUANTTOTHEREQUIREMENTS OF10CFRli:(Checkoneormore)(19)20.2203(a)(2)(ii) 20.2203(a)(2)(iii) 20.2203(a)(2)(iv) 20.2203(a)(4) 50.36(c)(1) 50.36(c)(2)

LICENSEECONTACTFORTHISLER(12)50.73(a)(2)(lv) 50.73(a)(2)(v) 50.73(a)(2)(vii)

OTHERSpecfyinAbstractbelowornNRCForm388AMs.M.B.Depuydt,Compliance EngineerTELEPHONE NUMBERtrnc/udeAreaCode)616/465-5901, x1589COMPLETEONELINEFOREACHCOMPONENT FAILUREDESCRIBED INTHISREPORT(13)"CAUSESYSTEMCOMPONENT MANUFACTURER REPORTABLE TOEPIXCAUSEMANUFACTURER REPORTABLE TOEPIXSUPPLEMENTAL REPORTEXPECTED14YESIfYes,cornletsEXPECTEDSUBMISSION DATEXNOEXPECTEDSUBMISSION DATE15YEARAbstract(Umitto1400spaces,l.e.,approximately 15single-spaced typewritten lines)(16)OnMarch10,1998,withUnits1and2inMode5,itwasdetermined thatbothunitshadoperatedinanunanalyzed condition duetoFunctional Restoration Procedure FRZ-1,"Response toHigh-High Containment Pressure",

notbeingconsistent withthecontainment integrity analysisofrecord.Hadtheprocedure beenimplemented, thepotential existedforpost-accident containment pressuretoexceeditsdesignbasislimitof12psig.Inaccordance with10CFR50.72(b)(2)(i),

anENSnotification wasmade.ThisLERistherefore submitted inaccordance with10CFR50.73(a)(2)(ii)(A),

foranunanalyzed condition, and10CFR50.73(a)(2)(ii)(B),

foracondition outsidethedesignbasis.Therootcauseofthiscondition wasinadequate interface withWestinghouse regarding theassumptions usedinthesafetyanalysis.

Theprocedure willberevisedtodirectinitiation ofRHRsprayattheappropriate pointtoensurethatcontainment designpressureisnotexceeded.

Aprogramwillbeestablished toidentify, documentandcontrolkeyaccidentanalysesassumptions, including thoseimpacting theEmergency Operating Procedures.

Additional actionswillbetakentostrengthen thecommunications betweenOperations andEngineering

-SafetyAnalysis, whichmaintains oversight ofvendorsperforming safetyanalysesthatmightimpactactionstakenbytheoperators.

Evaluation ofthiscondition hasbeenperformed.

Ithasbeenconcluded thatcontainment pressurewouldhaveexceededthedesignpressureof12psig,reachingacalculated peakof13.85psig.Thisvalueremainedbelowthepre-operational structural integrity testvalueof16.1psig,therefore, itwasconcluded thatthecontainment wouldhaveremainedfunctional.

'3)'3)07280073) 990722PDRADOCK05000315PDR NRCFORM366AU.S.NUCLEARREGULATORY COMMISSION (6-1998)LICENSEEEVENTREPORT(LER)TEXTCONTINUATION FACIUTYNAME(1)CookNuclearPlantUnit1DOCKETNUMBER(2) 05000-315 YEAR1998LERNUMBER(6)SEQUENTIAL NUMBER014REVISIONNUMBER03PAGE(3)2of3TEXT(ifmorespaceisrequired, useadditional copiesofNRCForm(366A)(17)Conditions PriortoEventUnit1wasinMode5,ColdShutdownUnit2wasinMode5,ColdShutdownDescritionofEventOnMarch10,1998,whileperforming aContainment Sprayselfassessment, itwasdetermined thattheactionsdirectedbyFunctional Restoration Procedure 1,2-4023.OHP.FRZ-1, "Response toHigh-High Containment Pressure",

werenotconsistent withtheassumptions inthecontainment integrity analysisofrecord.ResidualHeatRemoval(RHR)(EIIS:BP) sprayisdesignedtosupplement thepressuremitigation functionofcontainment sprayduringeitheraLossofCoolantAccident(LOCA)orMainSteamLineBreak(MSLB).Inaccordance withcontainment integrity analysisinputassumptions, FRZ-1directsthatRHRspraybemanually, initiated whencontainment pressurereaches8psig.Thesafetyanalysisdidnotmakeallowance forthetimedelaybetweencontainment pressurereaching8psigandthedeliveryofRHRspraytocontainment.

Thistimedelayresultsfromthesummation ofthetimerequiredfortheoperatortorecognize thatcontainment pressurehasreached8psig;fortheRHRsprayvalvestoopenandRHRtoReactorCoolantsystemisolation valvestoclose/throttle; andforRHRflowtofillthespraylineandsprayheaders.Hadtheuseofthisprocedure initscurrentformbeenrequired, containment peakpressuremitigation wouldhavebeenaffected.

CauseofEventThiscondition wastheresultofaninadequate interface withWestinghouse regarding theassumptions usedinthesafetyanalysisandhowtheywereimplemented attheplant.Equipment responsetimesandoperatoractiontimeswerenotincludedbyWestinghouse whenassumptions regarding RHRspraywereincorporated intotheanalysis.

AnalsisofEventThiscondition wasdetermined tobereportable inaccordance with10CFR50.73(a)(2)(ii)(A),

foranunanalyzed condition thatsignificantly compromises plantsafety,and10CFR50.73(a)(2)(ii)(B) foracondition outsidethedesignbasis.TheEmergency CoreCoolingSystem(ECCS)isoneoftheEngineered SafetyFeaturesystems,whichmitigatetheconsequences ofamajorbreachoftheReactorCoolantsystem(RCS),ormainsteamlinesinsidecontainment.

TheRCSlinebreakresultsinaLOCA,duringwhichtheECCSprovidesasignificant volumeofmakeuptotheRCSaswellascorecoolingandreactivity control.TheLOCAhasbeendetermined tobetheboundingaccidentscenarioforpeakcontainment pressure.

InresponsetoaLOCAtheECCSoperatesintwophases.Theinitialphase,knownastheinjection phase,startsatthereceiptofasafetyinjection signalresulting inautomatic startoftheECCSpumps.Thepumpstransfertheboratedwatercontained intheRefueling WaterStorageTank(RWST)totheRCStoprovidemakeupforlostcoolantandcorecooling/reactivity control.AstheRWSTisdepleted, theECCSpumpsuctionsarere-aligned tothecontainment recirculation sumptocommencetherecirculation phase,whichprovideslongtermreactorcoreandcontainment cooling.TheECCSconsistsof6ECCSpumps-2highheadCentrifugal Chargingpumps(EIIS:BQ),

2mediumheadSafetyInjection pumps(EIIS:BQ),

and2lowheadRHRpumps(EIIS:BP)

-plusheatexchangers, accumulator tanks,andtheassociated pipingvalvesandinstrumentation.

TheRHRpumpsstartonasafetyinjection signalandinjectboratedwaterfromtheRWSTatahighrateofflowintotheRCSwhentheRCSpressuredropsbelowtheshutoffheadoftheRHRpumps,asinthecaseofalargebreakLOCA(LBLOCA).NRCFORM366A(6-1998)

NRCFORM366AU.S.NUCLEARREGULATORY COMMISSION (6-1998)LICENSEEEVENTREPORT(LER)TEXTCONTINUATION FACILITYNAME(1)CookNuclearPlantUnit1DOCKETNUMBER(2) 05000-315 YEAR1998LERNUMBER(6)SEQUENTIAL NUMBER014REVISIONNUMBER03PAGE(3)3of3TEXT(ifmorespaceisrequired, useaddilfonal copiesofNRCForm(366A)(17)Theinjection phaseoftheECCSoperation isterminated aftertheleveloftheRWSTleveldropstoapre-determined point.ThesuctionfortheRHRpumpsandContainment Spraypumps(CTS)isthentransferred tothecontainment recirculation sump.Ifrequired, aportionoftheRHRflowcanbedivertedtotheuppercontainment RHRsprayheadersduringtherecirculation phasetosupplement thecontainment coolingoperation oftheCTS.Thiscanbeinitiated shouldthecontainment pressureriseaftertheinitialpressuresuppression following aLOCA.Undertheseconditions, ifcoretemperature issatisfactory, theoperatormaydivertoneorbothtrainsofRHRfrominjection toRHRsprays,therebysupplementing CTSsprayflowwithanadditional 1890gallonsperminutepertrain.Evaluation oftheidentified delayincommencing RHRsprayhasbeenperformed, considering notonlythisparticular condition, butotherconditions whichcouldhaveaneffectonpeakcontainment pressure.

Theresultsofthisevaluation, usingthelicensing basisLOTICcode,indicated thepeakcontainment pressuretobe13.85psig,whichisabovethecurrentdesignbasisof12psigbutbelowitsultimatecapability of36psig.While13.85psigisabovethelicensing andtechnical specification basisof12psig,itislessthanthe16.1psigthattheunitsweresubjected tointheirpre-operational structural integrity testing.Therefore, itwasconcluded thatthecontainment wouldhaveremainedfunctional evenifitwaspotentially subjected topressures ashighas13.85psig.Corrective ActionsThecontainment integrity analysiswillbeusedtodetermine theappropriate pointtoinitiateRHRspraytoensurethatthe12psigcontainment designpressure, following apostulated

accident, isnotexceeded.

Thistaskwillbecompleted byAugust31,1999.TheFunctionRestoration Procedure FRZ-1,"Response toHigh-High Containment Pressure" willberevisedtobeconsistent withthenewanalysisandwillallowtimeforinitiation ofRHRspray,repositioning ofvalves,andfillingofRHRspraylines.AsUnit2willbereturnedtoservicefirst,theUnit2procedure willberevisedandapprovedbyDecember1,1999,withtheprocedure forUnit1scheduled forrevisionandapprovalbyJanuary30,2000.Toalleviate theinterface problemwithWestinghouse, aprogramisbeingdeveloped andimplemented toidentify, documentandcontrolthekeyaccidentanalysesassumptions usedinthesafetyanalyses, including thosethatcanbeimpactedbyoperatoractionintheEOPs,thekeyeventsinvolving operatoractiondurationthatcanimpactthesafetyanalysesandarepartoftheEOPs,andthesetpoints thatwillbesubjecttoengineering controlthatarepartoftheEOPs.Implementation oftheprogramwillbecompletebyAugust31,1999.PreviousSimilarEventsNoneNRCFORM366A(6-1998)