ML17157C138

Safety Consequences of Boiling Spent Fuel Pool at Susquehanna Steam Electric Station.

ML17157C138
Person / Time
Site:	Susquehanna
Issue date:	07/27/1992
From:	LOCHBAUM D A PENNSYLVANIA POWER & LIGHT CO.
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ML17157C139	List: ML17157C138 ML17157C140 ML17157C141 ML17157C142 ML18026A248
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NUDOCS 9301050141
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SAFETYCONSEQUENCESOFABOILINGSPENTFUELPOOLATTHESUSQUEHANNASTEAMELECTRICSTATIONJUlp21g1992Preparedhy:Davd.LochbaumDonaldC.Prevatte930i0501%i92if27'PDRADOCK050003878PDR I}f'IfI,'(p EXECUTIVESUMMARYEngineeringDiscrepancyReport(EDR)G20020waswritteninApril1992afterninepotentialproblemsassociatedwiththeboilingspentfuel-pooleventwereidentifiedduringsystemevaluationstosupportthepoweruprateprojectforPP&L'sSusquehannaSteamElectricStation.ThemajorconcernsraisedinEDRG20020are:1~Regulationsrequirethatinstrumentationshallbeprovidedforthefuelstoragesystemstodetectconditionsthatmayresultinlossofheatremovalcapabilityandtoinitiateappropriatesafetyactions.Contrarytothisrequirement,thewaterlevelandtemperatureinstrumentationforthespentfuelpoolsdonotsatisfyClass1Ecriteriaandarenotincludedintheequipmentqualificationprogram.Theseinstrumentswillfailfollowingalossofoffsitepowerandmayfailfollowingalossofcoolantaccident.Theultimateconsequenceofsuchfailurecouldbe'nirradiatedfuelmeltdownoutsideprimarycontainment.2~Regulationsrequirethatnuclearpowerplantdesignslimitpersonnelradiationexposuresto<5Remperindividualforcontrolroomoccupationandactionsrequiredtomitigateorrecoverfromanaccident.3~Contrarytothisrequirement,themanualESWvalvemanipulationsrequiredtoprovidemakeuptoaboilingspentfuelpoolfollowingalossofcoolantaccidentcouldrequirearadiationexposuresignificantlyhigherthan5Rem.TheultimateconsequencecouldbesignificantradiationoverexposureorinabilitytoprovideESWmakeupandanirradiatedfuelmeltdownoutsideprimarycontainment.Regulationsrequirethatstructures,systemsandcomponentsimportanttosafetybedesignedtoaccommodatetheeffectsoftheenvironmentalconditionsassociatedwithpostulatedaccidents.4~Contrarytothisrequirement,theeffectsofESWmakeupwatertoaboilingspentfuelpoolhavenotbeenconsideredintheSSESdesign.Theeffectsincludeflooding,hightemperature,andhighhumidity.TheultimateconsequencescouldincludefailureofmultipleECCSandothersafetyrelatedsystems.Regulationsrequirethatelectricalequipmentbequalifiedtothetemperatureforthemostseveredesignbasisaccidents.Contrarytothisrequirement,theSSESreactorbuildingtemperatureanalysesusedinequipmentqualificationevaluationsdonotaccountfortheheatloadfromaboilingspentfuelpool.TheultimateconsequencescouldincludefailureofmultipleECCSandothersafetyrelatedsystems.

-SafetyConsequencesofaBoilingSpentFuelPoolSYSTEMDESCRIPTIONEachofthetwooperatingnuclearpowerplantsatthePennsylvaniaPowerandLight(PP&L)Company'sSusquehannaSteamElectricStation(SSES)hasaspentfuelpool.Eachspentfuelpoolisdesignedtostoreupto2,840irradiatedfuelbundlesdischargedfromthereactorcoreafterapproximatelyfourandahalfyearsofoperation.AsofJuly1992,theUnit1spentfuelpoolcontained1400irradiatedfuelbundlesandtheUnit2spentfuelpoolheld1004irradiatedfuelbundles.Theirradiatedfuelbundlesstoredinthespentfuelpoolsgenerateheatfromthenucleardecayoffissionproducts.Theamountofheatgenerationexponentiallydecreaseswithtimeasafunctionofthehalflifeofthefissionproducts.Thespentfuelpoolsarelocatedinacommonrefuelingareawithinthesecondarycontainmentstructure.Eachspentfuelpoolisconnectedtoareactorcavityandtotheotherspentfuelpool.Thereactorcavityistheareaabovethereactorpressurevesselwhichisfloodedduringarefuelingoutageafterremovingthedrywellshieldblocks,drywellheadandreactorpressurevesselheadtopermitfueltransferbetweenthereactorcoreandthespentfuelpool.Theseconnectionsarenormallyisolated,exceptduringrefuelingoutages,usinggates.Unit1ReactorCavityUnit1SpentFuelPoolCaskPitUnit2SpentFuelPoolUnit2ReactorCavityEachspentfuelpoolhasafuelpoolcoolingandcleanupsystem(FPCCS)whichcirculateswaterfromthefuelpoolthroughaheatexchangeranddemineralizertomaintainproperfuelpoolwaterchemistryandtokeepitstemperature<125oF.-TheFPCCShasadesigncapacityof13.2x106BTU/hr.AsofJuly1992,thedecayheatloadintheUnit2spentfuelpoolwas=2.1x106BTU/hrwhilethedecayheatloadintheUnit2spentfuelpoolwas=2.97x106BTU/hr.HeatfromtheFPCCSheat,exchangersistransferredtotheservicewater(SW)systemwhichinturndissipatestheenergytotheatmosphereviathecoolingtower.TheFPCCSandtheSWsystemarenon-safetyrelatedsystemswhicharenotdesignedtosatisfyseismic,Class1Epower,equipmentqualificationandsinglefailurecriteria.TheFPCCSisdesignedsuchthatitcannotfailinawaywhichdrainswaterfromthespentfuelpool.July27,1992Page2 SafetyConsequencesofaBoilingSpentFuelPoolIftheFPCCSisunavailable,thefuelpoolcoolingassistmodeoftheresidualheatremoval(RHR)systemisdesignedtocirculatewaterfromthespentfuelpoolthroughaheatexchangertokeepthefuelpoolfromboiling.ThefuelpoolcoolingassistmodeofRHRismanuallyinitiatedbyopeningvalvesinthereactorbuilding.ThefuelpoolcoolingassistmodeofRHRhasacapacityof32.6x106BTU/hr.HeatfromtheRHRheatexchangeristransferredtotheRHRservicewater(RHRSW)whichinturndissipatestheenergytotheatmosphereviathespraypond.ThefuelpoolcoolingassistmodeofRHRisanon-safety.relatedfunctionwhichisnotdesignedtosatisfyseismic,Class1Epower,andsinglefailurecriteria.ThefuelpoolcoolingassistmodeofRHRisdesignedsuchthatitcannotfailinawaywhichdrainswaterfromthespentfuelpool.IfboththeFPCCSandthefuelpoolcoolingassistmodeofRHRareunavailable,thespentfuelpoolwaterwillboilunlesscoolingisre-established.Thetimerequiredtoreachboilingisafunctionofthedecayheatloadinthespentfuelpool,theinitialtemperatureofthewater,andthevolumeofwateravailable.Thevolumeofwateravailableisprimarilydependentuponthepresenceorabsenceofthegatesbetweenthespentfuelpoolsandthereactorcavity.Theemergencyservicewater(ESW)systemisdesignedtoprovidemakeuptotheboilingspentfuelpooltocompensateforwaterlostthroughboil-offandevaporation.TheESWmakeupsupplyismanuallyinitiatedbyopeningthreevalvesinthereactorbuilding.TheESWsystemuseswaterfromthespraypond.TheESWsystemandthespraypondaresafetyrelatedsystemswhicharedesignedtosatisfyseismic,Class1Epower,andsinglefailurecriteriaasapplicable.ThedesignprovisionatSSESisfortheESWsystemtoprovideadequatemakeuptoaboilingspentfuelpoolifcoolingislost.Thereactor.buildingheating,ventilatingandairconditioning(RB-HVAC)systemcirculatestemperedairthrougheachreactorbuildingandtherefuelingzoneduringnormaloperation.TheRB-HVACsystemmaintainstheseareasataslightnegativepressurerelativetotheoutsideenvironmenttoprevent.leakage.ofpotentiallyairborneradioactivitytotheatmosphere.Theexhaustfromthepotentiallycontaminatedareasisfilteredtoremoveradioactivematerials.Inanemergency,thesupplyandexhaustlinesareisolatedandtheRB-HVACsystemrecirculatesairthroughoutthereactorbuildingaffectedbytheemergencyandtherefuelingzone.Duringalossofoffsitepower(LOOP),thesupplyandexhaustlinesareisolatedandtheRB-HVACsystemrecirculatesairthroughoutthebothreactorbuildingsandtherefuelingzone.TheRB-HVACsysteminrecirculationmodedoesnotprovideanycoolingfunction,sothereactorbuildingandrefuelingzoneairtemperaturesincreasebaseduponpiping,lighting,transmissionandequipmentheatloads.July27,1992Page3 SafetyConsequencesofaBoilingSpentFuelPoolThestandbygastreatmentsystem(SGTS)isdesignedtomaintainthesecondary.containmentatanegativepressurerelativetotheoutsideenvironmentinanemergency.TheSGTStakessuctionontherecirculationplenumoftheRB-HVACsystemandprocessesthisairthroughafiltertraintoremoveradioactivematerials.TheSGTSisnormallyinstandbyexceptduringtesting.TheSGTSisdesignedtosatisfyseismic,Class1Epower,andsinglefailurecriteria.Theemergencycorecoolingsystems(ECCS),andthereactorcoreisolationcooling(RCZC)systemarelocatedinthelowerelevationsofeachreactorbuilding.Thesesystemsprovidewaterto.thereactorpressurevesselduringtransientsandaccidents.Thesesystemsarenormallyinstandbyexceptduringtesting.TheECCSaredesignedtosatisfyseismic,Class1Epower,andsinglefailurecriteria.BOILINGSPENTFUELPOOLDESIGNANALYSISSSESFinalSafetyAnalysisReport(FSAR)Appendix9Areportstheresultsofananalysisperformedtoquantifytheradiologicalconsequencesofalossofspentfuelpoolcoolingevent.TheanalysisassumedtheinitiatingeventwasanearthquakewhichresultedinthefailureoftheFPCCSonbothunits.TheanalysisconcludedthatthesecondarycontainmentdesignwithSGTSoperationkeptoffsitedosestoasmallfractionof10CFR100limitsevenwithconservativeassumptionsofinitialfuelfailuresinthespentfuelpools.CONTAINMENTDESIGNANALYSESSSESFinalSafetyAnalysisReport(FSAR)Chapter6reportstheresultsofanalysesperformedtodemonstratethecapabilityofthesafetyrelatedsystemstomitigatetheconsequencesofpostulatedaccidentssuchthatthecontainmentdesignparametersarenotexceeded.Thepostulatedaccidentsincludedmainsteamlinebreaksandloss-of-coolantaccidents(LOCAs)withandwithoutconcurrentlossofoffsitepower.Adesignbasisaccident(DBA)forSSESisdefinedasaLOCAwithasimultaneousLOOPandsafeshutdownearthquakeandtheworstcasesinglefailurewhichresultsinthemaximumcontainmentpressureandtemperatureconditions.SSESFSARChapter6indicatesmargintocontainmentdesignparametersfortheanalyzedpostulatedaccidents.Reactorbuildingroomtemperaturesfollowingpostulatedaccidentswereanalyzedforequipmentqualification.Aproceduretomanuallyshedallthenon-Class1Epowerloadsinthereactorbuilding=24hoursafteraLOCAwithoutaLOOPwasdevelopedtopreventroomtemperaturesfromexceedingequipmentqualificationlimitations.July27,1992Page4

~~SafetyConsequencesofaBoilingSpentPuelPoolCONCERNSOVERBOZLZNGSPENTFUELPOOLEVENTEngineeringDiscrepancyReport(EDR)G20020waswritteninApril1992afterninepotentialproblemsassociatedwiththeboilingspentfuelpooleventwereidentifiedduringsystemevaluationstosupportthepoweruprateproject.ThefourmajorconcernsraisedinEDRG20020are:ZnadequateZnstrumentationA.ReuaorReu'ets10CFR50AppendixAGeneralDesignCriterion63statesthat"appropriatesystemsshallbeprovidedinfuelstorageandradioactivewastesystemsandassociatedhandlingareas(l)todetectconditionsthatmayresultinlossofresidualheatremovalcapabilityandexcessiveradiationlevelsand(2)toinitiateappropriate'safetyactions."Regulatory'uide1.97definesaccident-monitoringinstrumentationtoinclude"thosevariablestobemonitoredthatprovidetheprimaryinformationrequfredtopermitthecontrolroomoperatorstotakethespecifiedmanuallycontrolledactionsforwhichnoautomatfccontrolisprovidedandthatarerequiredforsafetysystemstoaccomplishtheirsafetyfunctionfordesignbasisaccidentevents."StandardReviewPlan(NUREG-0800)9.1.3statesthatthereviewofthespentfuelpoolcoolingandcleanupsystemdesignincludes"theinstrumentationprovidedforinitiatingappropriatesafetyactions."StandardReviewPlan(NUREG-0800)9.1.3forthespentfuelpoolcoolingandcleanupsystemstatesthatthe"safetyfunctiontobeperformedbythesysteminallcasesremainsthesame;thatis,thespentfuelassembliesmustbecooledandmustremaincoveredwithwaterduringallstorageconditions."StandardReviewPlan(NUREG-0800)7.1statesthat"fnformationsystemsimportanttosafetyincludethosesystemswhichprovideinformationformanualinitfationandcontrolofsafetysystems,toindicate'hatplantsafetyfunctionsarebeingaccomplished,andtoprovideinformationfromwhichappropriateactionscanbetakentomitigatetheconsequencesofanticipatedoperationaloccurrencesandaccfdents."July27,1992Page5 SafetyConsequencesofaBoilingSpentFuelPoolB.~Co~ce~sTheESWsystemisrequiredtoprovidemakeupwatertothespentfuelpoolsfollowinglossoffuelpoolcoolingtokeeptheirradiatedfuelcoveredthuspreventingfueldamagefromoverheating.AlossofoffsitepowerorLOCAcanresultinlossoffuelpoolcoolingsincetheFPCCSandtheSWsystemarenotnormallysuppliedbyClass1Epower.Thelossofoffsitepowerwillalsodisablethespentfuelpooltemperatureandlevelinstrumentsmonitoredbytheoperatorandusedtoinitiatethesafety'ctionofprovidingESWmakeuptotheboilingspentfuelpool.Thepost-LOCAenvironmentinthereactorbuildingmaydisablethespentfuelpooltemperatureandlevelinstrumentssincetheyarenotcoveredundertheequipmentqualificationprogram.Therefore,theexistingspentfuelpooltemperatureandlevelinstrumentationisinadequatetoensuretherequiredsafetyactionofprovidingadequatemakeupto.aboilingspentfuelpoolisproperlyinitiatedandmonitoredunderallpostulatedaccidentconditions.Zfthespentfuelpoolispermittedtoboilwithoutadequatemakeup,itswaterlevelwilldrop.AstudybythePP&LNuclearSafetyAssuranceGroup(NSAGReport13-84,December1984)reportedthatwaterlevelinthespentfuelpooldroppingtowithinfiveinchesofthetopoftheirradiatedfuel"wouldcauseradiationlevelsonthe818'levationofthereactorbuildinginexcessof200,000rem/hour."Atthatdoserate,anindividualontherefuelingfloorwouldreceivealethalradiationexposureinapproximately16seconds.Thissevereconditionisjustthebeginningoftheadverseconsequencesofspentfuelpoolboilingwithoutadequatemakeup.Atthispoint,theradiationsourcetermresultsinoffsitedosesexceeding10CFR100limitsandindoserateswithinthereactorbuildingthatpreventanypersonnelaccess..-Thesituationprogressesultimatelytouncoveringirradiatedfuelbundlesinthespentfuelpoolandfueldamagefromoverheating.Thesituationhasthepotentialforasubstantialmeltdownofirradiatedfueloutsidetheprimarycontainment.July27,1992Page6 SafetyConsequencesofaBoilingSpentFuelPool2~ManualESRValveOperationA.etoReuiremetsandLices'o'tments10CFR20.1requireslicenseesto"makeeveryreasonableefforttomaintainradiationexposures...aslowasisreasonablyachievable."10CFR50AppendixAGeneralDesignCriterion19requiressuitabledesignfeaturestolimitcontrolroomradiationexposureto5rem.GDC19alsorequiresdesignfeaturesforequipmentoutsidethecontxolroomtopermitoperationinaccordancewithsuitableprocedures.10CFR50.47(b)(11)statesthatlicenseesassurethat"meansforcontrollingradiologicalexposures,inanemergency,areestablishedforemergencyworkers.ThemeansforcontrollingradiologicalexposuresshallincludeexposureguidelinesconsistentwithEPAEmergency8'orkerandLifesavingActivityProtectiveActionGuides."SSESFSAR18.1.20inresponsetoNUREG-0737ItemIZ.B.2statesthat"eachlicenseeshallprovideforadequateaccesstovitalareasandprotectionofsafetyequipmentbydesignchanges,increasedpermanentortemporaryshielding,orpostaccidentproceduralcontrols.Thedesignreviewshalldeterminewhichtypesofcorrecti,veactionsareneededforvitalareasthroughoutthefacility."SSESFSAR18.1.20.3.3.4.1definesvitalareasasthose"whichwillormayrequireoccupancytopermitanoperatortoaidinthemitigationoforrecoveryfromanaccident."SSESFSAR18.1.20.3.2.1statesthat"areviewwasmadetodeterminewhichsystemscouldberequiredtooperateand/orbeexpectedtocontainhighlyradioactivematerialsfollowingapostulatedaccidentwheresubstantialcoredamagehasoccurred."JulySSESFSAR18.1.20.3.2.5states="exposuresforareasnotcontinuouslyoccupied(frequentandinfrequentoccupancy)mustbedeterminedcasebycase,thatis,multiplythetaskdurationbytheareadoserateatthetimeofexposure."SSESFSAR18.1.20.3.3.3statesthat"GDC19isalsousedtogoverndesignbasesforthemaximumpermissibledosagetopersonnelperforminganytaskrequiredpost-accident.Theserequirementstranslateroughlyintotheob)ectivestobemetinthepost-accidentreviewasgivenbelow.27I1992Page7 SafetyConsequencesofaBoilingSpentFuelPoolRadiationExposureGuidelinesOccupancyDoseRateObjectivesContinuousl5mR/hrFrequent200mR/hrInfrecprent500mR/hrAccessway5R/hrDoseObjective5Remforduration5Rem-allactivities5RemperactivityInclinabovedoses"SSESFSAR18.1.20.3.4.3statesthatthereviewresults"showthatthereactorbuildingwillbegenerallyinaccessibleforseveraldaysaftertheaccidentduetocontainedradiationsources."SSESFSARFigure18.1-4showsRoomI-105whereESWvalves153500/153501arelocatedtobeinRadZoneVIIIwithdoseratesover5000R/hr.SSESFSARFigure18.1-6showsRoomI-514whereESWvalves153090A&Band153091A&BarelocatedtobeinRadZoneVwithdoseratesbetween5and50R/hr.ThesevalvesmustbemanuallyopenedtoinitiateESWmakeupto.thespentfuelpoolsinthelossoffuelpoolcoolingevent.PP&LadministrativeprocedureNDI-6.4.3specifiesthatthewholebodydoseforlifesavingactions"shallnotexceed75rem"andthewholebodydoseforentryintoahazardousareatoprotectfacilitiesorequipment"shallnotexceed25rem."10CFR20'sALARAprovisionrequiresplantdesigntominimizeradiationexposure.Applicationoftheemergencydoseguidelinestoadesignwhichrequiresmanualvalveoperationiscontrarytotheintentof10CFR20.1and10CFR50AppAGDC19.B.ConcernsTheESWsystemisrequiredtoprovidemakeuptothespentfuelpoolsfollowinglossoffuelpoolcooling.Eitheraseismiceventorlossofoffsitepowercanleadtolossoffuelpoolcooling.BothconditionsareassumedtooccurconcurrentwithaLOCAintheDBAforcontainmentanalyses.However,thepost-LOCAdoseratesinthereactorbuildingareaswherethemanualvalvesarelocatedare5to5,000+R/hrandwillpreventthesevalvesfrombeing'ccessedwithoutexcessiveradiationexposuretotheoperator.Inaddition,thereactorbuildingtemperature,humidityandemergencylightingconditionswouldnotbeconducivetothelocationandmanipulationofmanualvalveswhichareusedinfrequently.Therefore,themanualESWvalvemanipulationsrequiredformakeuptoboilingspentfuelpoolsmaynotbeaccomplishedforallpostulatedaccidentconditions.,July27I1992Page8 SafetyConsequencesofaBoilingSpentFuelPool3~Znaddition,sincetheboilingspentfuelpoolanalysisreportedinSSESFSARAppendix9Aassumedaseismiceventinitiatedthelossoffuelpoolcooling,theintentionalsheddingofnon-Class1EpowerloadsinthereactorbuildingfollowingaLOCAwithoutaLOOPrepresentseitherthecreationofanevkindofaccidentortheincreasedprobabilityofapreviouslyanalyzedaccident.EffectsofESWMakeupWateronReactorBuildingSystemsA.ReuatorReuireents'cesnCommtmetsandDesiBases10CFR50AppendixAGeneralDesignCriterion4statesthat"structures,systems,andcomponentsimportanttosafetyshallbedesignedtoaccommodatetheeffectsofandtobecompatiblewiththeenvironmentalconditionsassociatedwithnormaloperation,maintenance,testing,andpostulatedaccidents,includingloss-of-coolantaccidents."StandardReviewPlan{NUREG-0800)3.4.1statesthatthereviewof"plantfloodprotectionincludesallstructures,systemsandcomponents(SSC)whosefailurecouldpreventsafeshutdownoftheplantorresultonuncontrolledreleaseofsignificantradioactivity..."andthatthisreview"alsoincludesconsiderationoffloodingfrominternalsources."SSESFSAR6.3.1.1.3statesthat,separationbarriersforECCS"shallbeconstructedbetweenthefunctionalgroupsasrequiredtoassurethatenvironmentaldisturbancessuchasfire,piperupture,fallingobjects,etc.,affectingonefunctionalgroupswillnotaffecttheremaininggroups.Inaddition,separationbarriersshallbeprovidedasrequiredtoassurethatsuchdisturbancesdonotaffectbothRCICandHPCI."JulySSESFSAR9.1.3.3statesthat"thedesignmakeupratefromeachESWloop.isbasedonreplenishingtheboil-offfromtheMNHLineachfuelpoolfor30daysfollowingthelossofFPCCScapacity."MinutesfromBechtelmeetingonHVACsystems(February1980)statesthatoriginalrequirementforSGTSwas"tohandlefumesfromaboilingfuelpool,"butthatSGTSwillnotbeabletohandlethismixturesincetheroomwillbecometoohot."ThisrequirementwillbedeletedfromtheFSAR."AninternalPPELengineeringworkrequest{EWR830658,March1983)noted"condensationmaybeexpectedfromthis27,1992Page9 SafetyConsequencesofaBoilingSpentFuelPoolevaporationwhichvillrundovntoloverlevelsoftheR.B.Villthiscause'ossofessentialequipment,particularlyelectrical?'asanevaluationbeenperformed?"Theresponsetothesequestionswas"Thisisaninappropriateformattoaskquestions.Commentsvererequestedandnonereceived.Furthermore,nobudgetexistsvithvhichtofundtheengineeringtimerequiredtorespondtothesequestions."B.Concerns4oTheultimateheatsinkandESWaredesignedtoprovide1.5milliongallonsofwatertoeachspentfuelpooloverthe30dayperiod.IntheLOCA-LOOPcondition,thereactorbuildingHVACsysteminZoneI,IIandIIIisolationmoderecirculatesrefuelingfloorairthroughoutallthreezones.Thewateraddedtothespentfuelpoolsendsupinthereactorbuildingfollowingboil-offandoverflow.Theeffectsofthiswateronthesafety-relatedstructures,systemsandcomponentsinthereactorbuildingshavenotbeenincludedindesignanalyses.TheECCSandRCICroomcoolersareknownnottobedesignedforlatentheateffects.DampersintheSGTSandRB-HVACsystemclosewhentheenteringairtemperatureexceeds165'F,whiletheboilingspentfuelpoolwascalculatedtoproduceairtemperaturesof=1804F,ThepotentialforcommonmodefailuresofmultipleECCSandsafety-relatedsystemssuchasthestandbygastreatmentsystemexists.Failureofoneormoreofthesesafety-relatedsystemscouldincreasetheconsequencesofpostulatedaccidents.ReactorBuildingHeatLoadsA.ReulatorReuiementsLicensinCommitmentsandDesinBases10CFR50.49requiresthatelectricalequipmentmustbequalifiedtothetemperature"forthemostseveredesignbasisaccidents."10CFR50AppendixAGeneralDesignCriterion4statesthat"structures,systems,andcomponentsimportanttosafetyshallbedesignedtoaccommodatetheeffectsofandtobecompatiblewiththeenvironmentalconditionsassociatedwithnormaloperation,maintenance,testing,andpostulatedaccidents,includingloss-of-coolantaccidents."AninternalPP&Lengineeringworkrequest(EWR830658,March1983)noted"theinitialboilingratecorrespondsto=3000cfmof2004vatervaporatoneatm.Istheequipmentwhichvillbeexposedtothisatmospherequalifiedforit?"TheresponseJuly27,1992Page10 SafetyConsequencesofaBoilingSpentFuelPooltothisquestionwas"This,isaninappropriateformattoaskquestions.Commentswererequestedandnonereceived.Furthermore,nobudgetexistswithwhichtofundtheengineeringtimerequiredtorespondtothesequestions."APP&Lengineeringreport(SEA-ME-099,December1987)analyzedreactorbuildingtemperaturesforLOCA,LOCA/LOOPandLOCA/falseLOCAcasesassumingspentfueltemperaturesremainedat125'F,butlistedasanonconservatismthatfuelpoolheatupintheLOCA/LOOPcasewouldresultinhigherheatloadsfromtheRHRsystems,fuelpoolwallsandfuelpoolsurface.B.~CocerSecondarycontainmentdesignanalysesarerequiredtoaccountforallheatloadsinthereactorbuildingincludingfromtheboilingspentfuelpool.Theexistingdesignreactorbuildingheatloadcalcsconsidersensibleheatfromtheboilingpool,butneglectlatentheat.Thesecalcsindicatelittlemargintoequipmentqualificationtemperaturelimitsinmanyroomsforamaximumheatloadinthereactorbuildingofapproximately5.5x106BTU/hr.Thetotaldesignheatloadfromthespentfuelpoolsis26.4x10BTU/hr,whichwouldaddatleastapproximately20.9x106BTU/hrtotheexistingmaximumheatload.Eventhecurrentheatloadsinthespentfuelpoolscouldincreasethemaximumheatloadinthereactorbuildingby=504.=-TheremainingfiveconcernsraisedinEDRG20020involvednonconservatismsinanalysesfortheboilingspentfuelpoolevent.DZSCUSSZONOFOPPOSINGVIEWPOINTThediscussionsandmeetingswhichhaveoccurredsinceEDRG20020wasinitiatedhaveyieldedoneprimaryargumentagainsttheissuesraisedinEDRG20020havingnuclearsafetysignificance.ThisargumentisthatthelicensingbasesLOCA/LOOPaccidentforSSESdoesnotassumeaboilingspentfuelpoolresultingfromtheevent.Inorderforthisassumptiontobevalid,spentfuelpoolcoolingmusteithernotbelostormustberestoredpriortoboiling.Thereareseveralfaultsinthisassumption:1)SincetheFPCCSandtheSWsystemarenon-safetyrelatedsystems,theircomponentsarenotincludedintheequipmentqualificationprogramandmaynotsurvivethepressure,temperature,humidityandradiationenvironmentinthereactoxbuildingfollowingapostulatedaccident.Therefore,theJuly27,1992Page11

SafetyConsequencesofaBoil.ingSpentFuelPoolFPCCSwhichisdefinitelylostfollowingaLOCA/LOOPmayalsobelostfollowingaLOCAwithoutaLOOP.2)SincethefuelpoolcoolingassistmodeofRHRisanon-safetyrelatedfunction,itscomponentsarenotincludedintheequipmentqualificationprogramandthereforemaynotsurvivethepressure,temperature,humidityandradiationenvironmentinthereactorbuildingfollowingapostulatedaccident.Inaddition,thefuelpoolcoolingassistmodeofRHRhasnotbeenutilizedsincetheinitialstartuptestingprogramanditsvalveswereremovedfromtheinserviceinspectionprogramseveralyearsagoandthevalvesmayhaveexperiencedfailureswhichhavenotyetbeendetectedwhichwouldpreventtheirsuccessfuloperation.Therefore,thefuelpoolcoolingassistmodeofRHRmaybelostfollowingaLOCA/LOOPandaLOCAwithoutaLOOP.3)ThefuelpoolcoolingassistmodeofRHRrequiresthemanualopeningofvalvesinthereactorbuildingwhichmaybeinaccessiblefollowingapostulatedaccidentduetoradiationlevels.4)FortheLOCA/LOOPcase,ithasbeenarguedthattheSSESdesignimplicitlyassumesrestorationofoffsitepowertypicallywithin24hoursandessentia.allyalwayswithin48hoursaftereventinitiation.SSESFSARChapter8reportsPP&Lgridexperienceinsupportoftheserestorationtimes.However,nodocumentationwasfoundwhichstatesthatPP&LhasdefinedtheLOOPdurationfordesignbasesevents.AsEDRG20020andEDRG00005bothaddress,thespentfuelpoolmaybeginboilinginlessthan24hours.Inanycase,thereactorbuildingtemperatureanalysesforequipmentqualificationpurposespresentlycounteranysuchcreditforrestorationofoffsitepowersincenon-Class1Epowerloadsinthereactorbuildingmaybeshed=24hoursafteroffsitepowerisrestoredinordertosatisfyroomtemperaturelimitations.EDRG20020identifiedconcernswiththeSSESdesignprovisionsfortheboilingspentfuelpoolevent.TheSSESdesign,coupledwithcurrentoperatingprocedures,wouldhavesignificantnuclearsafetyconsequencesifalossofspentfuelpoolcoolingoccurred.Therefore,theseconcernsmustberesolvedforSSES.Inaddition,manyoftheseconcernsareapplicabletootherBWRsandpossiblyevenPWRsintheUnitedStates.Therefore,theseconcernsmustbereportedtoINFO/NRCinorderfortheadverseconditiontoberemediedthroughouttheindustry.July27,1992Page12

Attachaent9PPSLMemofromG.D.MillertoG.T.Jones,"FuelPoolCoolingDeficiencies",Augustl8,1992(ET-0586)Kote:ThismemobythePPSLSupervisor,EngineeringProjectsprovidesanindicationofhowPP&LnarrowedtheirscopeofevaluationfortheconcernsinEDRG20020tojustthedesignofthefuelpoolcoolingandcleanupsystem.Withtheexceptionoftheinstrumentationforthefuelpools,the.designofthefuelpoolcoolingandcleanupsystemhasnotbeenchallengedinEDRG20020and'tssubsequentsupportingdocuments.Theconcernsarethattheeffectsofboi1ingspentfue1poolson~h~esystemsandcomponentsinthereactorbuildinghavenotbeenadequately.analyzed.

0RANDUHPage1DATE:8/18/92TO:G.T.JonesFRON:G.D.HillerA6-2A6-3JOB:EngineeringTechnologyNUHBER:ET-0586COPIES:DistributionCorres.FileA6-2EngrTechFileA6-3FILE:A45-1AREPLY:Notapplicable

SUBJECT:

FuelPoolCoolingDeficienciesThefollowingactionsarebeingtakeninresponsetoconcernsraisedabouttheEORprogramandthefuelpoolcoolingissuesdescribedinEDRG20020andEORG00005.ERProcessChanesTheEDRprocessgoverningprocedure,EPH-gA-122,willberevisedasfollows:2.Theappealprocessdescribedinparagraph5.4willberevisedwiththefirststepoftheappealchangedtotheEngineeringReviewCommittee.Subsequentappealmaybe.toeithertheHanager-NuclearEngineering,Superintendent-SSES,orHanager-NSAG.Themanagementreviewdescribedinparagraph5.14willberevisedtoinclude:a~b.PeriodicreviewofallinvalidEDRsbytheEngineeringReviewCommittee,andPeriodicreviewofallEDRsopengreaterthansixmonthsbytheEngineeringReviewCommittee.FuelPoolCoolinOeficiencResolutionEngineeringTechnologyhasresponsibilitytoresolvebothEDRs(EORG00005waspreviouslyassignedtoSystemEngineering).TheseEDRsareassignedtoHarkHjaatvedtandarebeingworkedfulltimebyHichaelCrowthers.TheEDREPH-101B,Rev.1 NEN0RANDUN(CONTINUATIONSHEET)evaluations(safetysignificance,operability/reportability)arebeingdonebyJimAgnewandJoeZola.OurinitialevaluationoftheseEDRshasconcludedthatthesafetysignificanceisminimal.ThisisbasedprimarilyonourunderstandingthatthedesignofthefuelpoolcoolingsystemwasspecificallyreviewedandapprovedbytheNRCwithfullknowledgeofthefactthattheFPCCSwasnotasafety'elatedsystemandthatfuelpoolboilingcouldbeexpectedtooccurunderaspecificcombinationofhypotheticalconditions.However,itisnotyetcleartowhatextenttheNRC{ortheindustry)consideredthelong-termeffectsofthefuelpoolboilingcondition.Therecordonthissubjectisconfusingandfurthercomplicatedbychangestothefueldesignandactualoutagepracticeswhichhave'notbeenaccountedforintheFSARanalysis.Mebelievethatthedesignandproceduralfeatureswhichexisttodayprovideareasonablelevelofassurancethattheactualsafetyconsequencesareminimized.However,procedureenhancementsandadditionaloperatortrainingareclearlyrequiredaspartoftheresolutionoftheseconcerns.ThisevaluationwillbefullydocumentedaspartoftherevisedEDRpackage.Afinalevaluationofthisconcernispredicatedoncompletionofahistoricalreviewofallavailabledocumentation.Thus,ourplanforresolutionincludes:I.Completeinvestigationofhistoricaldesignandlicensinginformation,includingrequestsforinformationfromtheoriginaldesignorganizations(GEandBechtel),2.Establishthefuelpoolandfuelpoolcoolingsystemdesignbasisbasedonthederiveddesignbasisandcurrentoperatingpractice,3.4,5.7.8.Reviewfuelpooldesignsofotherboilingwaterreactors,Completeanewanalysisofthefuelpoolandfuelpoolcoolingsystembasedontheestablisheddesignbasis,Prepareapoint-by-pointcomparativedescriptionofourcurrentoperatingpracticeanddesignbasisagainsttheoriginalFSARanalysis{includingtheindividualissuesidentifiedintheEDR),Listandassesseachdeviationfromtheoriginalanalysisasdescribedinitem5,Prepareanoperabilityevaluationaccountingforeachdeviationasadditionalinformationbecomesavailable,Re-evaluateallissuesforreportability{ongoing),Preparerecommendationsto,resolveeachissuedesc}ibedinitem4.EPN-IOIC,Rev.I{51)

Page3EN0RANDU(CONTINUATIONSHEET)Weplantokeeptheoriginatorsoftheseconcernsinformedofourprogressasweworkourwaythroughthiseffort.Aformalplanincludingschedulefortheaboveactivitiesisunderdevelopment.IndeendentReviewbSstemsAnalsisSystemsAnalysis(KevinBrinckman)isintheprocessofconductinganindependent,designreviewoftheseissues.Additionally,IhaverequestedtheirreviewofthisissuefromanIPEperspectivewhenresourcesbecomeavailable.AssessmentofEDRProcessAsafollowupactivityIplantorequestanassessmentoftheEDRprocessfromanindependentorganization.Thisassessmentwillfocusspecificallyonthevalidationandverificationstepsoftheprocess.ThisshouldbeconductedbyNSAG.NgAhasonceinthepastconductedanauditoftheprocess.Theydonotgthtd~iitiiydf'lli.Thydfi.ydiscrepancytobeaconditionadversetoquality,whereasourprogramrecognizesthepotentialfordiscrepanciesindocumentationwhichdonotconstituteactualdeficientconditions.OtherprogrammaticauditshavetakenplaceontheEDRprocess,butnonehaveexaminedthephilosophyorcriteriausedtodeterminethevalidityofengineeringissues.EPN-101C,Rev.1(51)

Attachaent10PP&LMemofromO.C.PrevattetoG.T.Jones,"FuelPoolCoolingOeficiencies",August20,1992(ET-0587)

MEMORANDUMTO:FROMJOB:NUMBER

SUBJECT:

G.T.JonesA6-2D.C.PrevatteA6-3EngineeringTechnologyET-0587REPLY:FuelPoolCoolingDeficienciesDATE:August20,1992FILE:A45-1Acc:DistributionCorres.FileA6-2ETFileA6-3ThismemoiswritteninresponsetoMr.G.D.Miller'smemoET-0586of8/18/92concerning+hedis"epanciesassociatedw-'ththefuelpoolcoolingsystemdescribedinEDRsG20020andG00005.Mr.Miller'smemostatesthat,"OurinitialevaluationoftheEDRshasconcludedthatthesafetysignificanceisminimal."IstronglydisagreewiththisevaluationandIherebyrequestthatthesafetysignificanceoftheseEDRs,particularlyEDRG20020bereevaluatedforthefollowingreasons:1.Theprimarybasisgivenfor'hisconclusionisthat"...thedesignofthefuelpoolcoolingsystemwasspecificallyreviewedandapprovedbytheNRCwithfullknowledgeofthefactthattheFPCCSwasnotasafetyrelatedsystemandthat'uelpoolboilingcouldbeexpectedtooccurunderaspecificcombinationofhypothetical,conditions."Iconsiderthisbasistobeinvalidforthefollowingreasons:a~b.ThisbasisappearstomissmostofthemainpointsofEDRG20020.Itfocusesonthenon-safetyrelatedFPCCSwhichisnottheconcern.TheprimaryconcernsarewiththeNRCmandated(Reg.Guide1.13),safety-relatedbackupcoolingschemeofallowingthefuelpooltoboilandprovidingmakeupwaterfromthesafety-relatedESWsystem.Theconcernisthepotentialinabilityoftheoperatorstoputthisschemeintoeffectbecauseofinaccessibilitytotheassociatedvalvesduetopost-LOCAradiationlevelsinthereactorbuilding,andthepotentialnegativeeffectsofaboilingspentfuelpoolonvirtuallyallofthesafety-relatedsystemsinthereactorbuilding,effectswhichhavenotbeenanalyzed.The"...specificcombinationofhypotheticalconditions..."referredtointhememoisLOCA/LOOP.Thisisnotsomeoff-the-wallaccidentscenarioastheresponseseemstoimply.Thisisthestandard,universallyrecognized,NRCmandateddesignbasisaccident(DBA).

G.T.JonesFuelPoolCoolingDeficienciesAugust20,1992Page22.Theconditionsofconcernarenotpostulated.TheyaremechanisticconsequencesofthatDBA.Thememoalsocitesasanotherbasis,confusionconcerningwhatwasoriginallyconsideredinthedesign,thechangestothefueldesign,andoutagepracticeswhichhavenotbeenaccountedforintheFSARanalysis.ThisbasiswouldseemtosupporttheEDRscontentions,notrefutethem.Ifindeedthereisconfusiononthesesubjects,then,atbest,theconditionisunanalyzedandthereforebydefinitioninNRCregulationsandourprocedures,asafetyconcern.Althoughthisinformationiscertainlypertinenttoahistoricalperspectiveoftheseconcerns,todeterminationofthemagnitudeoftheheatloadsinvolved,andtoformulationofthecorrectiveactionsthatmaybeeffected,itisnotpertinenttotheabilityoftheplanttoperformasrequiredfortheDBAconditions.Theinformationtomakethisdeterminationisclearandavailabletoday.3~Anotherbasiscitedisthat"...thedesignandproceduralfeatureswhichexisttodayprovide.areasonablelevelofassurancethattheactualsafetyconsequencesareminimal."Thereisnoelaborationonwhatthesedesignandproceduralfeaturesare.InconversationswithMr.MillerandotherswhoseemtoconsidertheEDRsashavingverylowsafetysignificance,nodesignorproceduralfeatureshavebeencited.Theonlyfeaturesthathavebeencitedare"heroicaction"oftheoperators,theEOPs,anEOCstaffwhowillunderstandtheconcernanddowhateverneedstobedone,andalowprobabilityofoccurrence.Thesearenotvalidfeatures.Heroicoperatoractionisnotavalidbasisforthedesignofaplant,noraretheEOPs(even'ftheywerecorrectinthisarea)whichaddressmanyconditionspotentiallyoutsidetheplantlicensingand/ordesignbases.And,contrarytothememo'scontention,theEOPsastheystandtodayarenotcorrect.Theycurrentlytelltheoperatorhehasaminimumof25hoursuntilthefuelpoolboils.Underworstcaseconditions,itmaybelessthanhalfthattime;andwiththeLOOP'conditions,hehasnoinstrumentationtotellhimtheconditionofthefuelpool.UnderDBAconditions,theoperatorisflyingblindusingnonconservativeinformation.Additionally,currentEOPsmovetheplanttowardtheconditionsofconcern,notawayfromthem.ThecurrentEOPsrequiredeenergizingthenon-1Eloadsinthereactorbuilding

~~G.T.JonesFuelPoolCoolingDeficienciesAugust20,1992Page3att=24hoursifreactorbuildingtemperaturesareasanalyzed.This,ineffect,imposesaLOOPonthereactorbuilding,thusinitiatingtheconditionsofconcern.TheknowledgeoftheEOCstaffisalsonotavalidfeatureiftheconditionsof.concernarenotformallyaddressedinanyofficialdesignand/orproceduraldocuments.-Althoughitisclaimedthattoday'sstaffwouldunderstandtheconcerns,thereisnoreasontobelievethisistruesincetheconcernsaren'tdocumentedoutsidetheEDRsandthereisnotrainingonthiseventuality.Andtenyearsfromnow,iftheconcernsarenotformalizedinwriting,theywillbeevenlessunderstood.Additionally,evenifthestaffdoesunderstand,iftheconditionsarenotanalyzed,whichtheyarenot,theplantcouldbebroughttoaconditionwhererecoveryisnotpossibleinspiteoftheirfullunderstanding.Lowprobabilityisalsonotavalidfeature.discussedindetailfurtherinthismemo.Thisis4~5.ThestatementinthememoregardingtheNRC's"...fullknowledgeofthefactthattheFPCCSwasnotasafety-relatedsystemandthatfuelpoolboilingcouldbeexpectedtooccurseemstoimplythatiftheNRCapproveditasis',thatmakesitacceptableevenifwediscoverdiscrepanciesthatmaynot,havebeenoriginallyconsidered.IamawareofnoevidencethatindicatestheNRCapprovedofourdesignwiththeunderstandingthat:(a)theoperatorwouldbeexposedtounacceptableradiationlevelsunderdesignbasisconditionsineffectingtheFSARdescribedfuelpoolboilschemeforalternatecooling;and(b)thattheboilingfuelpoolmightcreateamyriadofunanalyzedconditionsinthereactorbuildingthatcouldthreatentheoperabilityofmanyofthesafety-relatedsystemsinthebuilding.Thememoconcludesthatthesafetysignificanceis"minimal."PerprocedureEPM-703,Rev.0,Section5.3,"...a'minimal'lassificationgenerallysignifiesadocumentationtypeofdiscrepancy."Znotherwords,notarealengineeringconcern,but'atheradocumentationerrorthatcanberesolvedbymakingeditorialchangestothedocuments.Perthisprocedure,ifanEDR'ssafetysignificanceisclassifiedas"minimal",itdoesnotevenhavetobeevaluatedforoperabilityandreportability.TheseEDRsarenotinanyreasonableevaluationjustadocumentationdiscrepancy.Theyarefundamentalengineeringconcernsraisedbytwoengineersintimatelyfamiliarwiththesystemsafterexhaustiveresearch.Todismisstheseconcerns G.T.JonesFuelPoolCoolingDeficienciesAugust20,1992Page4byclassifyingthemasjustadocumentationdiscrepancyisludicrous.Ifconcernssuchasthesedon'tevengettothestageintheprocesswheretheyarerequiredtobeevaluatedforoperabilityandreportability,concernswhichinvolvethesafetyoftheoperatorsandpotentialthreattovirtuallyeverysafety-relatedsysteminthereactorbuilding,thenwhatdoesittaketotriggeroperabilityandreportabilityevaluations?Thethresholdappearstobemuchtoohigh.6.Thememo'sreferenceto"...aspecificcombinationofhypotheticalconditions..."impliesaprobabalisticargumentastowhythesafetysignificanceis"minimal."Indeed,inconversationswithMr.Millerandothersthisargumenthasbeenexplicitlyraised.Thisargumentisnotvalidwithregardtodesignbasesforseveralreasons.First,ourdesignbasisconditionsofLOCA/LOOPwhichproducetheconditionsofconcernaremandatedbyregulation.That,fordesignpurposes,dictatesaprobabilityof1.Second,evenforLOCAwithoutaLOOP,ourcurrentEOPsdictateaself-imposedLOOPonthereactorbuildingat24hours,againmakingtheprobabilityforLOCA/LOOPequall.Third,evenforaLOOPorFPCCSsystemfailurewithoutaLOCA,theconsequencesoffuelpoolboilareunanalyzed.Fourth,EDRprocedureEPM-703,Rev.0,Section5.3,hasasacaution,capitalized,boldlettersandunderlinedasfollows,"TheEDMGEvaluatormustnotputheavyemphasisontheperceivedsmallprobabilityofoccurrenceortheexpectedsatisfactoryoutcomeofanalysisorreanalysistojustifycontinuedoperationwiththeexistingdiscrepancy."Section5.4goesontosay,"SAFETYSIGNIFICANCEmustbebasedonthepotentialadverseconsequencesoffailures,eventhoseofverylowprobability."Thus,byourprocedures,potentialconsequencesshouldbethedominantfactorinevaluatingsafetysignificance,notprobability.ThepotentialconsequencesoftheconcernsraisedintheseEDRs,andsubsequentdocumentationgeneratedbyMr.Lochbaumandmyself,areverygrave.TheEDRprocessatPP&Lwasdevelopedinresponsetoa1990SALPinspectionfindingthatsafetysignificantissueswerenotbeinghandledinatimelymanner.OurEDRproceduresarefilledwithwordsthatreflectthisconcern;wordslikequickly,expeditiously,immediately,early,timely.Forthestepwherewearetoday,the"screening"step,theprocedures'EPM-703,Rev.0,Section5.2)

G.T.JonesFuelPoolCoolingDeficienciesAugust20,1992Page5intentisthatEDRsbe"quickly"screenedafteradiscrepancyenterstheEDRprocess.Asoftoday,theofficialscreeningstillhasnotbeencompletedfourmonthsaftertheEDRenteredtheprocess,andapproximatelyonemonthafterMr.LochbaumandIpersonallybroughttheseconcernstoyourattention.NeithertheintentoftheprocedurenortheintentoftheNRCarebeingfulfilled.TheplanoutlinedinMr.Miller'smemoforthe"finalevaluation"wouldappeartofurtherdelaytherequiredactions.Althoughalloftheactivitiesintheplanareimportanttounderstandingtheproblemsmorecompletelyandeffectingthemosteffectiveolutions,noneofthemareprerequisitesforperformingavalid"screening",and.mostofthemarenotrequiredtodetermineoperabilityandreportability.Tomaketheseactivitiesprerequisitesforafinal"screening"evaluationandthenfortheoperabilityandreportabilitydeterminations,istofurtherdelaytheprocessunnecessarily.Theinformationisavailabletomakethesedeterminationstoday,andtheyshouldbemadeimmediatelyifwearetodowhat'slegitimatelyrequiredofus.Ihavemademyownoperabilityandreportabilitydeterminationsbasedonextensiveresearchontheseconcerns.Atbest,theoperabilityofthefuelpoolcoolingintheboilandfeedmode,thefuelpoolinstrumentation,andmuchofthesafety-relatedequipmentinthereactorbuildingisunanalyzedwithregardtotheeffectsoftheboilingfuelpoolonthisequipment,withstrongindicationsthat,analysiswouldshowit.asinoperable.Ifthisisthecase,per10CFR50.72and50.73,itisreportable.Iwouldwelcomeanyhard,definitive,documentaryinformationindicatingthatmyconclusionsarewrong.BothMr.LochbaumandI,andforthatmatter,manyotherswhowouldliketoseedifferentconclusions,havesearchedforcontraryevidence.Tothebestofmyknowledge,nonehasbeenfound.kThisisnottosaythattheplantshouldnecessarilybeshutdown.Ibelievethatverycredibleargumentscanbe,madeforaJ.I.O.Ithereforedon'tunderstandwhythereissuchanapparentreluctanceintheorganizationtoacknowledgetheseconcernsandmoveaheadwithresolutionexpeditiously.Althoughresolutionwillhaveacost,certainly,thatcostdoesnotnecessarilyhavetoincludeplantshutdown.Ithereforestronglyurgethattheformalscreeningevaluationandtheevaluationsoftheoperabilityandreportabilityoftheseconcernsproceedwithout,furtherdelaywithpriorityoverallotheractivitiesinMr.Millersplan,andthatweexpeditiouslygetonwiththeprocessofr'esolvingtheseconcerns.

G.T.JonesFuelPoolCoolingDeficienciesAugust20,1992Page6I.sincerelyappreciateyourcontinuedpersonalattentioninthesematters,andIamatyourserviceinaddressingtheseconcerns.DISTRIBUTION:J.E.F.G.R.G.M.H.G.D.G.J.D.A.AgnewButlerByramCrowthersGogatesKuczynskiLochbaumA6-3A6-3A6-1A6-3SSESSSES,S&AEnerconG.D.MillerJ.R.MittenbergerM.R.MjaatvedtC.A.MyersJ.G.ReflingJ.S.StefankoT.J.SweeneyJ.A.ZolaA6-3A6-1A6-3A2-4A6-3A9-3SSESA6-3FUELPOOL.DCP/kbw Attachaent11PP8LMemofromA.DyszeltoT.C.Dalpiaz,"U2RI05FuelPoolDecayHeatEvaluation",August21,1992(PLI-72230)Note:ThislettertransmitsinterimguidancetotheSSESsitepersonnelforuseduringanupcomingrefuelingoutage.ThisguidanceisnecessarybecauseEDRG00005,initiatedinSeptember1990,hasnotyetbeendispositionedandtheapplicablediscussionsinFSARSection9.1andAppendix9Aareno-longeraccurate.

18-22-199215:57P.82z84'UegestZ3g3992T.t.OalpfazSSES...-g<>~.!>rl'~sg'gqhlily>(breSUSgUEHNNASTGNELECTRICSTATION02RI05FUELPOOLDECA'IHEATBALNTIOHCCH741687FILEeAI~"w7

References:

I}PLI-8?533,"FuelPoolCoolingHeatLoads-KOR600005,'prflIZ,1991.2)PLI-70395,'Ul8106FuelPoolDecayHeatEvaluation,"February7,1992.3}ET-0585,"FuelpoolCaalfngOeffciencfes,"8/18/92.ThismemoprovidesshorttarerelieffortheopenEOR,600005,{Ref<<rence1}withrespecttoCheupcoofngNSRIObyprovidingNFK'sevaluationaftheresultfnaCiseconstraintsforperforaanceafcoaaoaRHRsystemoutagework,similar4theU1RI05evaluationNeference2}.Alongtemsolutianto.thisEORisrequiredtoensurefuturesuccessful,Cfeelyauiages.fnshort,theU25RIDevaluatianshowsnachangeinihecurrentoutageschedule(f.~.,Sept.28forcoamonRHRsysteiwork}fornafuelfailuresinQnft8Cycl~S.However,futureevaluations,whichwillinvolvehigherheatloadsandaddressChepotentialforfuelfailure(s),willlikelyaffecttheoutageschedule.Reference3providesadescr)ptianofthelongCeresolutfantothisproblem.3QLXFSARSectionS.Adescribestheradiologicalreleaseresultsfroaalossaffuelpoalcoolingevent.111'ssuaptfonsusedforCheFSNlanalysisinclude4carereloads,incarefuelshuffling,andaaaxfeuafuelexpasureof28,500ND/NTM.ThecurrentaperationatSusquehannaSESincludesafuelreloadbatchsizeotaaoroxfiatelyWofihecore,amaxfeulfueldischargeexpasureafl0,001i%8/OU,andafullcoreoffloadforeachoutage.Ifonearmorefuelfeflureseresuspectediohaveoccurredduringthepperatingcyclejustprfartaanoutageordurinofuelhandlingaft<<rshutdown,analyses-oustb<<performedtoassuretheradio'logicalreleasefreethepastulatedlassoffuelpoolcoalfngeventarelessthanthosepresentedinCheFSAR.TheFSARanalysesareboundingprovidedthatcateeonRHRsysteeoutageworkisnotstarteduntilthedecayheatlave'lislowenoughtopreventfuelpoolhailingfnlessthan25hours.Ifnafuelfailuresaresuspectedtohaveoccurredduringiheop<<retinacyclejustpriortoanoutageorduringfuelhandlingaftershutdown,analyseserstbeperformedtoassurethefuelpoolwaterievelcanbeaafntafnedduringalassoffuelpoolcoolingevent.Thefuelpool iO-22-iGQ2i5:58P.03r84waterlevelCaaheeaiatatae4previdedthate~NOSgatmeugeneWrhiahOCStartersutilQe-CNmelee'lotpatetethespehtfueipeeltle.o40CPll)isgreaterthanthespentfuelpoolboilingratederringthelossoffuelpoolcoo'lingevent.Toaddressthisissuefortheupcomingoutage.NuclearFuelsEngineeringhascalculatedthetotaldecayheatofthefuelinthespentfue)poolsfortheU25RIQconsistentwiththeapproachinReference2.Thisdecayheatleva)includesatotalofthedecayheatfroothefuelintheUIpool,U2pool,andthefullcoreoffload.F)gurelshowsthecalculatedspentfue)pooldecayheatasafunctionoftimeaftershutdown.Thecurvelabelled'nominal'sacalculationofthedecayheatbasedonthemethodolag'yinNlRKG-OSQO.ThismethodologyhasbeenshowntoproducehigherdecayheatlevelsthanthemorerigorousmethodologyintheAHSS.S-I919decayheatstandard.Thecurvelabelled"maximum'salsobasedonthemethodo'logyinNUREG-0800butaccountsforuncertaintyinthereactorpowerlevel(lo}anduncertaintyinthedecayheatmethodology.NuclearFuelsEng1neerinohasalsoperformedacalculationtodetermine.CheCfmeaftertheU2t3shutdownthatthespentfuelpoolboilingrateduringapostulatedlossofspentfuelgalcoolingevent1slessthanthe60GNENmakeupflowrate.BasedonChe"aaximum"decayheatcurveinf1gureI.aspraypondteeperatureofSO'F,andopenfuelpoolgates.thefuelpoolboil1ngrateduringapostulatedlossoffuelpoolcoolingeventislessthanthe60OPNESMmakeupraCesubsequentto)4daysafterreactorshutdown.Therefore,HFE'sevaluationindicatesthatprovididfuelfa11uredoesnotoccurduringtheremainingV2C5operationorduringfuelhandlingaftershutdown,coslonRHRsystemoutageworkshouldnotstartunC11atleast14daysafterreactorshutdown.[fafuelfa1lureoccurs,acalcu1ationshouldbeperformedtodetermineiffurCheroutagerestrict1onsarenecessary.Notethattheabovecalculationshavebeendocumented1nNFE-B-NA-OhS.Rev.2andindependentlyreviewedinaccordancewithqAproceduresEN-N-301.The)4darestr1ctiononcottisencementofcoamonRHRsystemworkdoesnotimpactthecurrentURIRKEDoutageschedule.A.DysxelNuclearfuelmanagementPro)octEngineerNuclearFuelsEngineeringAD/elmel311a.adcc:J,E.K.Q.G.T.J.N.C.R.G.DaAgnewHarwankoJonestelickLehmannHillerSSESSSESAS-2AS3Ag-3AS~3A.J.Rosc1oliR.A.SacconeJ.P.SpadaroJ.5.StefankoZolaNRFileA9-3SSESAS3A9-3A5-3A5'2 RGURE1U25RIOSPENTFUELPOOLDEGAYHEATg1PLUSU2}GIIVIVIfUg~~0~~~~Q~lisoDAYSAFTERHOTSHU7DQVW'0~rb~yb AttachIIent12PP8LMemofromJ.M.KennytoG.T.JonesandC.A.Myers,"EDRonFuelPoolCooling",August25,1992Note:.This'confidential'emoisthefirstdocumentedindicationthattheNRChadbeeninformallynotifiedoftheconcernsraisedinEDRG20020.

~~~QQNF1QQQTIALAugust25,1992G.T.JonesC.A.MyersA6-2A2-4EDRONFUELPOOLCOOLINGOnAugust24,1992IbriefedbothScottBarberandJimRaleighoftheNRConthestatusofourreviewofcontractororiginatedfuelpoolcoolingconcernsdocumentedonanEDR.Inotedthatourcurrentpositionwastherewerenoimmediateconcernswithsystemoperabilityorneedforreportabilityunderregulationsidentifiedbutthatoureffortswerecontinuingtoaddresstheidentifiedissues.IalsonotedthatGeorgeJoneshaddiscussedtheconcernswiththecontractorsandwaspersonallyinvolvedinresolvingtheissues.IhadpreviouslybriefedJimRaleighinJulyofthefuelpoolconcernsandreviewsbeingperformed;ScottdidbringtomyattentionanopeninspectorfindingconcerningtheHaddam¹ckfuelpooldraindowneventandsubsequenteffortsbyNSAGonfuelpoolissues.Henotedtherewere28openitemsandthatweshouldreviewtheseissuesforstatus.IindicateditwasmyunderstandingEngineeringwouldbeaddressingtheNSAGopenissuesonthefuelpoolaspartoftheirefforttoresolvetheopenEDR.k%.M.KennyCC:J.E.AgnewA6-3G.D.MillerA6-3J.R.MiltenbergerA6-1R.R.SgarroA2-4H.G.StanleySSESJMK:tahFuelPool.EDR

Attachment13PP8LMemofromGeorgeT.JonestoGlennD.Miller,"FuelPoolCoolingEDR's620020,G00005",August27,1992(PLI-72267)

~~~ppp<<y<<pp;.,0p<<{RAugust27,1992GlennD.MillerA6-3SUSQUEHANNASTEAMELECTRICSTATIONFUELPOOLCOOLINGEDR'SG20020,G00005PLI-72267FILE'45-IA

Reference:

ET-0587,ET-0586ThereferencelettersshowmethattherestillisadifferenceofprofessionalopinionrelativetothesignificanceofthesubjectEDR's.Thisdifferenceistoberesolved.Thisissueistobeworkedexpeditiouslyuntilwehaveresolvedtheoutstandingquestions.IwishtopointoutthatourbeliefthatadesignhasbeenreviewedandapprovedbyNRC,isnotadequatejustificationforclassificationofthesignificanceofanissue.Theissuemuststandonit'sownmerits.IamfurtherconcernedthatouractualconfigurationandmethodofoperationapparentlydiffersfromthatdescribedintheFSAR..TheFSARisourlicensedbasesandanydeviationfromthatdescriptionisrequiredtohaveathoroughandcompletedocumentedevaluationonfile.Thereweretwenty-eightopenitemsresultingfromNSAGReviewofFuelPoolCooling.Theseneedtobeincludedinthisrevie'w.Iwishtohavethescheduleforresolutionofthisissueacceleratedandtheclassificationofthesignificanceofthisissuereevaluated.Iamexpectingatleastdailyupdatesofourprogress.Ifyouhavequestions,pleasecallme.>AMGeorge.onesAttachmentCC:J.E.F.G.R.G.M.H.G.D.G.J.D.A.S.M.AgnewButlerByramCrowthersGogatesKuczynskiLochbaumHausemanA6-3w/aA6-3w/aA6-Iw/aA6-3w/aSSESw/aSSES,SMw/aEnerconw/aA6-2w/aD.C.J.R.M.R.C.A.J.G.T.J.J.A.Nuc.PrevatteMiltenbergerHjaatvedtMeyersRef1ingSweeneyZolaRec.FilesA6-3w/aA6-Iw/aA6-3w/aA2-4w/aA9-3w/aSSESw/aA6-3w/aA6-2w/oc:Xvp51%docs%2002M5.sgt8/26/92 Attachaent14PP8LMemofromGlenn0.MillertoGeorgeT.Jones,"FuelPoolCoolingEDRs620020,G00005",August.31,1992(PLI-72297)

~~August31,1992GeorgeT.JonesA6-2SUSQUEHANNASTEAHELECTRICSTATIONFUELPOOLCOOLINGEDRsG20020,G00005PLI-72297FILEA45-I

Reference:

PLI-72267,ET-0587,ET-0586InresponsetoyourletterPLI-72267wearecontinuingtoworktoresolvetheissuesinthereferencedEDRs.AsIexplainedtoyoupreviouslyImetwithHr.PrevatteanddiscussedhisconcernsatlengthonAugust21.Weacknowledgedourdifferencesandagreedtocontinueworkingtowardresolution.IwanttoreemphasizetoyouthatwearenotusingthepriorreviewandapprovalofoursystemdesignbytheNRCasabasisfortheclassificationofthesafetysignificanceofthisissue.StatementswhichImadeinET-0586relativetothesafetysignificancewereintendedtosummarizetheEDMGpositiononscreening.ThereferencetotheNRCisonlyastatementofthefactthatourdesignchilosophyatthetimeoflicensingwasreviewedandapprovedbytheNRC.Thispositioninfactconstitutesourlicensingbasis.TheFSARcontainsreferencestoanalysesregardingtheFuelPoolCoolingandCleanupSystemandtheFuelPool.Itdoesnotdescribetheexactmannerinwhichweoperate'theplant.OurcurrentfueldesignandfuelcycledeviatesfromtheFSARdescription.ThisisthesubjectofG00005.OuroutagepracticesdifferfromthedescriptionintheFSAR.ThecurrentoutagepracticeisthesubjectofaperiodicanalysisdonebyNuclearFuelsforeachrefuelingoutage.Wehavereviewedthetwenty-eight"openitems"fromtheNSAGreview.Twenty-sixofthetwenty-eightitemswereresolvedtothesatisfactionofNSAG.TheremainingtwoitemsrefertotheneedforthelevelandtemperatureindicationtobeavailableinthecontrolroomviaaPHS(computerdisplay)formatandtoaddreflashcapabilityforalarmsfrompanelOC211.Thesemodificationsareonthebooksbutnotbeingactivelyworkedtothebestofmyknowledge.EDMGcompletedarevisiontotheEDRscreeningforG20020onFridayAugust28,1992andrequestedcomments.Thesignificancewasevaluatedasminimal.BasedonmyreviewofthisscreeningdocumentitisunacceptableaswrittenandIhaverequesteditberevised.Weareproceedingtoreviewtheissueforreportabilityregardlessofthefinalsignificancelevelfromthescreeningreview.WorkonresolvingtheissueisassignedtoHarkHjaatvedt.MichaelCrowthershasbeenworkingonthisissuesinceJuly20,1992.IhavealsoassignedDaveKostelnikasoftoday.WeareplanningtoinvolveBechtelandGE.Ascheduleisunderdevelopment.

August31,1992PLI-72297FILEA45-1ASystemsAnalysis'ndependentevaluationwillbecompletedthisweek.Wewillfactortheirevaluationintoourongoingwork.Iwillreportontheirresultswhenavailable.Iwillcontinuetokeepyouapprisedofourprogressonadailybasis.GlennD.Millercc:J.E.AgnewF.G.ButlerR.G.ByramM.H.CrowthersG.D.GogatesG.J.Kuczynski58@RZcdg~ayyp'.-S.M.HausemanA6-3A6-3A6-IA6-3SSESSSES~4'a'.~U~*~":iS45con'6-2D.C.PrevatteJ.R.MiltenbergerM.R.MjaatvedtC.A.MyersJ.G.ReflingJ.S.StefankoT.J.SweeneyJ.A.ZolaNuclearRecordsA6-3A6-1A6-3A2-4A6-3A9-3SSESA6-2 Attachment15PP8LMemofromKevinM.BrinckmantoGeorgeT.Jones,"ReviewofFuelPoolCooling",September1,1992(PLI-72288)Note:ThisengineeringreportwaspreparedbyaPPALengineerpreviouslynotassociatedwithEORG20Q20attherequestofthePP8LManagerofNuclearPlantEngineeringtoprovidehimwithanindependentappraisaloftheconcernsraisedintheEOR.ThisindependentevaluationbasicallyconcludesthataLOCAwithalossofnormalfuelpoolcoolingwouldputtheoperators"inapositionwheretheywouldberequiredtomakedecisionsonremovingECCSequipmentfromcontainment/corecoolingservicetocoolthefuelpool"andpointsoutthatitwouldinvolveunanalyzedconditions.Thisreportalsoraises,forthefirsttime,theconcernthatthehydrodynamicloadsoftheLOCAmightdamagethenon-seismic,non-safetyrelatedfuelpoolcoolingsystempiping.