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.
To:
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ML17157C139	List: ML17157C138 ML17157C140 ML17157C141 ML17157C142 ML18026A248
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NUDOCS 9301050141
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SAFETYCONSEQUENCES OFABOILINGSPENTFUELPOOLATTHESUSQUEHANNA STEAMELECTRICSTATIONJUlp21g1992Preparedhy:Davd.LochbaumDonaldC.Prevatte930i0501%i 92if27'PDRADOCK050003878PDR I}f'IfI,'(p EXECUTIVE SUMMARYEngineering Discrepancy Report(EDR)G20020waswritteninApril1992afterninepotential problemsassociated withtheboilingspentfuel-pool eventwereidentified duringsystemevaluations tosupportthepoweruprateprojectforPP&L'sSusquehanna SteamElectricStation.ThemajorconcernsraisedinEDRG20020are:1~Regulations requirethatinstrumentation shallbeprovidedforthefuelstoragesystemstodetectconditions thatmayresultinlossofheatremovalcapability andtoinitiateappropriate safetyactions.Contrarytothisrequirement, thewaterlevelandtemperature instrumentation forthespentfuelpoolsdonotsatisfyClass1Ecriteriaandarenotincludedintheequipment qualification program.Theseinstruments willfailfollowing alossofoffsitepowerandmayfailfollowing alossofcoolantaccident.

Theultimateconsequence ofsuchfailurecouldbe'nirradiated fuelmeltdownoutsideprimarycontainment.

2~Regulations requirethatnuclearpowerplantdesignslimitpersonnel radiation exposures to<5Remperindividual forcontrolroomoccupation andactionsrequiredtomitigateorrecoverfromanaccident.

3~Contrarytothisrequirement, themanualESWvalvemanipulations requiredtoprovidemakeuptoaboilingspentfuelpoolfollowing alossofcoolantaccidentcouldrequirearadiation exposuresignificantly higherthan5Rem.Theultimateconsequence couldbesignificant radiation overexposure orinability toprovideESWmakeupandanirradiated fuelmeltdownoutsideprimarycontainment.

Regulations requirethatstructures, systemsandcomponents important tosafetybedesignedtoaccommodate theeffectsoftheenvironmental conditions associated withpostulated accidents.

4~Contrarytothisrequirement, theeffectsofESWmakeupwatertoaboilingspentfuelpoolhavenotbeenconsidered intheSSESdesign.Theeffectsincludeflooding, hightemperature, andhighhumidity.

Theultimateconsequences couldincludefailureofmultipleECCSandothersafetyrelatedsystems.Regulations requirethatelectrical equipment bequalified tothetemperature forthemostseveredesignbasisaccidents.

Contrarytothisrequirement, theSSESreactorbuildingtemperature analysesusedinequipment qualification evaluations donotaccountfortheheatloadfromaboilingspentfuelpool.Theultimateconsequences couldincludefailureofmultipleECCSandothersafetyrelatedsystems.

-SafetyConsequences ofaBoilingSpentFuelPoolSYSTEMDESCRIPTION Eachofthetwooperating nuclearpowerplantsatthePennsylvania PowerandLight(PP&L)Company's Susquehanna SteamElectricStation(SSES)hasaspentfuelpool.Eachspentfuelpoolisdesignedtostoreupto2,840irradiated fuelbundlesdischarged fromthereactorcoreafterapproximately fourandahalfyearsofoperation.

AsofJuly1992,theUnit1spentfuelpoolcontained 1400irradiated fuelbundlesandtheUnit2spentfuelpoolheld1004irradiated fuelbundles.Theirradiated fuelbundlesstoredinthespentfuelpoolsgenerateheatfromthenucleardecayoffissionproducts.

Theamountofheatgeneration exponentially decreases withtimeasafunctionofthehalflifeofthefissionproducts.

Thespentfuelpoolsarelocatedinacommonrefueling areawithinthesecondary containment structure.

Eachspentfuelpoolisconnected toareactorcavityandtotheotherspentfuelpool.Thereactorcavityistheareaabovethereactorpressurevesselwhichisfloodedduringarefueling outageafterremovingthedrywellshieldblocks,drywellheadandreactorpressurevesselheadtopermitfueltransferbetweenthereactorcoreandthespentfuelpool.Theseconnections arenormallyisolated, exceptduringrefueling outages,usinggates.Unit1ReactorCavityUnit1SpentFuelPoolCaskPitUnit2SpentFuelPoolUnit2ReactorCavityEachspentfuelpoolhasafuelpoolcoolingandcleanupsystem(FPCCS)whichcirculates waterfromthefuelpoolthroughaheatexchanger anddemineralizer tomaintainproperfuelpoolwaterchemistry andtokeepitstemperature

<125oF.-TheFPCCShasadesigncapacityof13.2x106BTU/hr.AsofJuly1992,thedecayheatloadintheUnit2spentfuelpoolwas=2.1x106BTU/hrwhilethedecayheatloadintheUnit2spentfuelpoolwas=2.97x106 BTU/hr.HeatfromtheFPCCSheat,exchangers istransferred totheservicewater(SW)systemwhichinturndissipates theenergytotheatmosphere viathecoolingtower.TheFPCCSandtheSWsystemarenon-safety relatedsystemswhicharenotdesignedtosatisfyseismic,Class1Epower,equipment qualification andsinglefailurecriteria.

TheFPCCSisdesignedsuchthatitcannotfailinawaywhichdrainswaterfromthespentfuelpool.July27,1992Page2 SafetyConsequences ofaBoilingSpentFuelPoolIftheFPCCSisunavailable, thefuelpoolcoolingassistmodeoftheresidualheatremoval(RHR)systemisdesignedtocirculate waterfromthespentfuelpoolthroughaheatexchanger tokeepthefuelpoolfromboiling.ThefuelpoolcoolingassistmodeofRHRismanuallyinitiated byopeningvalvesinthereactorbuilding.

ThefuelpoolcoolingassistmodeofRHRhasacapacityof32.6x106BTU/hr.HeatfromtheRHRheatexchanger istransferred totheRHRservicewater(RHRSW)whichinturndissipates theenergytotheatmosphere viathespraypond.ThefuelpoolcoolingassistmodeofRHRisanon-safety.

relatedfunctionwhichisnotdesignedtosatisfyseismic,Class1Epower,andsinglefailurecriteria.

ThefuelpoolcoolingassistmodeofRHRisdesignedsuchthatitcannotfailinawaywhichdrainswaterfromthespentfuelpool.IfboththeFPCCSandthefuelpoolcoolingassistmodeofRHRareunavailable, thespentfuelpoolwaterwillboilunlesscoolingisre-established.

Thetimerequiredtoreachboilingisafunctionofthedecayheatloadinthespentfuelpool,theinitialtemperature ofthewater,andthevolumeofwateravailable.

Thevolumeofwateravailable isprimarily dependent uponthepresenceorabsenceofthegatesbetweenthespentfuelpoolsandthereactorcavity.Theemergency servicewater(ESW)systemisdesignedtoprovidemakeuptotheboilingspentfuelpooltocompensate forwaterlostthroughboil-offandevaporation.

TheESWmakeupsupplyismanuallyinitiated byopeningthreevalvesinthereactorbuilding.

TheESWsystemuseswaterfromthespraypond.TheESWsystemandthespraypondaresafetyrelatedsystemswhicharedesignedtosatisfyseismic,Class1Epower,andsinglefailurecriteriaasapplicable.

Thedesignprovision atSSESisfortheESWsystemtoprovideadequatemakeuptoaboilingspentfuelpoolifcoolingislost.Thereactor.buildingheating,ventilating andairconditioning (RB-HVAC)systemcirculates temperedairthrougheachreactorbuildingandtherefueling zoneduringnormaloperation.

TheRB-HVACsystemmaintains theseareasataslightnegativepressurerelativetotheoutsideenvironment toprevent.leakage.

ofpotentially airborneradioactivity totheatmosphere.

Theexhaustfromthepotentially contaminated areasisfilteredtoremoveradioactive materials.

Inanemergency, thesupplyandexhaustlinesareisolatedandtheRB-HVACsystemrecirculates airthroughout thereactorbuildingaffectedbytheemergency andtherefueling zone.Duringalossofoffsitepower(LOOP),thesupplyandexhaustlinesareisolatedandtheRB-HVACsystemrecirculates airthroughout thebothreactorbuildings andtherefueling zone.TheRB-HVACsysteminrecirculation modedoesnotprovideanycoolingfunction, sothereactorbuildingandrefueling zoneairtemperatures increasebaseduponpiping,lighting, transmission andequipment heatloads.July27,1992Page3 SafetyConsequences ofaBoilingSpentFuelPoolThestandbygastreatment system(SGTS)isdesignedtomaintainthesecondary

.containment atanegativepressurerelativetotheoutsideenvironment inanemergency.

TheSGTStakessuctionontherecirculation plenumoftheRB-HVACsystemandprocesses thisairthroughafiltertraintoremoveradioactive materials.

TheSGTSisnormallyinstandbyexceptduringtesting.TheSGTSisdesignedtosatisfyseismic,Class1Epower,andsinglefailurecriteria.

Theemergency corecoolingsystems(ECCS),and thereactorcoreisolation cooling(RCZC)systemarelocatedinthelowerelevations ofeachreactorbuilding.

Thesesystemsprovidewaterto.thereactorpressurevesselduringtransients andaccidents.

Thesesystemsarenormallyinstandbyexceptduringtesting.TheECCSaredesignedtosatisfyseismic,Class1Epower,andsinglefailurecriteria.

BOILINGSPENTFUELPOOLDESIGNANALYSISSSESFinalSafetyAnalysisReport(FSAR)Appendix9Areportstheresultsofananalysisperformed toquantifytheradiological consequences ofalossofspentfuelpoolcoolingevent.Theanalysisassumedtheinitiating eventwasanearthquake whichresultedinthefailureoftheFPCCSonbothunits.Theanalysisconcluded thatthesecondary containment designwithSGTSoperation keptoffsitedosestoasmallfractionof10CFR100limitsevenwithconservative assumptions ofinitialfuelfailuresinthespentfuelpools.CONTAINMENT DESIGNANALYSESSSESFinalSafetyAnalysisReport(FSAR)Chapter6reportstheresultsofanalysesperformed todemonstrate thecapability ofthesafetyrelatedsystemstomitigatetheconsequences ofpostulated accidents suchthatthecontainment designparameters arenotexceeded.

Thepostulated accidents includedmainsteamlinebreaksandloss-of-coolant accidents (LOCAs)withandwithoutconcurrent lossofoffsitepower.Adesignbasisaccident(DBA)forSSESisdefinedasaLOCAwithasimultaneous LOOPandsafeshutdownearthquake andtheworstcasesinglefailurewhichresultsinthemaximumcontainment pressureandtemperature conditions.

SSESFSARChapter6indicates margintocontainment designparameters fortheanalyzedpostulated accidents.

Reactorbuildingroomtemperatures following postulated accidents wereanalyzedforequipment qualification.

Aprocedure tomanuallyshedallthenon-Class 1Epowerloadsinthereactorbuilding=24hoursafteraLOCAwithoutaLOOPwasdeveloped topreventroomtemperatures fromexceeding equipment qualification limitations.

July27,1992Page4

~~SafetyConsequences ofaBoilingSpentPuelPoolCONCERNSOVERBOZLZNGSPENTFUELPOOLEVENTEngineering Discrepancy Report(EDR)G20020waswritteninApril1992afterninepotential problemsassociated withtheboilingspentfuelpooleventwereidentified duringsystemevaluations tosupportthepoweruprateproject.ThefourmajorconcernsraisedinEDRG20020are:Znadequate Znstrumentation A.ReuaorReu'ets10CFR50AppendixAGeneralDesignCriterion 63statesthat"appropriate systemsshallbeprovidedinfuelstorageandradioactive wastesystemsandassociated handlingareas(l)todetectconditions thatmayresultinlossofresidualheatremovalcapability andexcessive radiation levelsand(2)toinitiateappropriate

'safetyactions."

Regulatory

'uide1.97definesaccident-monitoring instrumentation toinclude"thosevariables tobemonitored thatprovidetheprimaryinformation requfredtopermitthecontrolroomoperators totakethespecified manuallycontrolled actionsforwhichnoautomatfc controlisprovidedandthatarerequiredforsafetysystemstoaccomplish theirsafetyfunctionfordesignbasisaccidentevents."StandardReviewPlan(NUREG-0800) 9.1.3statesthatthereviewofthespentfuelpoolcoolingandcleanupsystemdesignincludes"theinstrumentati onprovidedforinitiatingappropriate safetyactions."

StandardReviewPlan(NUREG-0800) 9.1.3forthespentfuelpoolcoolingandcleanupsystemstatesthatthe"safetyfunctiontobeperformed bythesysteminallcasesremainsthesame;thatis,thespentfuelassemblies mustbecooledandmustremaincoveredwithwaterduringallstorageconditions."

StandardReviewPlan(NUREG-0800) 7.1statesthat"fnformation systemsimportant tosafetyincludethosesystemswhichprovideinformationformanualinitfationandcontrolofsafetysystems,toindicate'hat plantsafetyfunctions arebeingaccomplished, andtoprovideinformation fromwhichappropriate actionscanbetakentomitigatetheconsequences ofanticipated operational occurrences andaccfdents."

July27,1992Page5 SafetyConsequences ofaBoilingSpentFuelPoolB.~Co~ce~sTheESWsystemisrequiredtoprovidemakeupwatertothespentfuelpoolsfollowing lossoffuelpoolcoolingtokeeptheirradiated fuelcoveredthuspreventing fueldamagefromoverheating.

AlossofoffsitepowerorLOCAcanresultinlossoffuelpoolcoolingsincetheFPCCSandtheSWsystemarenotnormallysuppliedbyClass1Epower.Thelossofoffsitepowerwillalsodisablethespentfuelpooltemperature andlevelinstruments monitored bytheoperatorandusedtoinitiatethesafety'ction ofproviding ESWmakeuptotheboilingspentfuelpool.Thepost-LOCA environment inthereactorbuildingmaydisablethespentfuelpooltemperature andlevelinstruments sincetheyarenotcoveredundertheequipment qualification program.Therefore, theexistingspentfuelpooltemperature andlevelinstrumentation isinadequate toensuretherequiredsafetyactionofproviding adequatemakeupto.aboilingspentfuelpoolisproperlyinitiated andmonitored underallpostulated accidentconditions.

Zfthespentfuelpoolispermitted toboilwithoutadequatemakeup,itswaterlevelwilldrop.AstudybythePP&LNuclearSafetyAssurance Group(NSAGReport13-84,December1984)reportedthatwaterlevelinthespentfuelpooldroppingtowithinfiveinchesofthetopoftheirradiated fuel"wouldcauseradiation levelsonthe818'levation ofthereactorbuildinginexcessof200,000rem/hour."

Atthatdoserate,anindividual ontherefueling floorwouldreceivealethalradiation exposureinapproximately 16seconds.Thisseverecondition isjustthebeginning oftheadverseconsequences ofspentfuelpoolboilingwithoutadequatemakeup.Atthispoint,theradiation sourcetermresultsinoffsitedosesexceeding 10CFR100limitsandindoserateswithinthereactorbuildingthatpreventanypersonnel access..-Thesituation progresses ultimately touncovering irradiated fuelbundlesinthespentfuelpoolandfueldamagefromoverheating.

Thesituation hasthepotential forasubstantial meltdownofirradiated fueloutsidetheprimarycontainment.

July27,1992Page6 SafetyConsequences ofaBoilingSpentFuelPool2~ManualESRValveOperation A.etoReuiremetsandLices'o'tments10CFR20.1requireslicensees to"makeeveryreasonable efforttomaintainradiation exposures

...aslowasisreasonably achievable."

10CFR50AppendixAGeneralDesignCriterion 19requiressuitabledesignfeaturestolimitcontrolroomradiation exposureto5rem.GDC19alsorequiresdesignfeaturesforequipment outsidethecontxolroomtopermitoperation inaccordance withsuitableprocedures.

10CFR50.47(b)(11) statesthatlicensees assurethat"meansforcontrolling radiological exposures, inanemergency, areestablished foremergency workers.Themeansforcontrolling radiologicalexposures shallincludeexposureguidelines consistent withEPAEmergency 8'orkerandLifesaving ActivityProtective ActionGuides."SSESFSAR18.1.20inresponsetoNUREG-0737 ItemIZ.B.2statesthat"eachlicenseeshallprovideforadequateaccesstovitalareasandprotection ofsafetyequipment bydesignchanges,increased permanent ortemporary shielding, orpostaccident procedural controls.

Thedesignreviewshalldetermine whichtypesofcorrecti,ve actionsareneededforvitalareasthroughout thefacility."

SSESFSAR18.1.20.3.3.4.1 definesvitalareasasthose"whichwillormayrequireoccupancy topermitanoperatortoaidinthemitigation oforrecoveryfromanaccident."

SSESFSAR18.1.20.3.2.1statesthat"areviewwasmadetodetermine whichsystemscouldberequiredtooperateand/orbeexpectedtocontainhighlyradioactive materials following apostulated accidentwheresubstantial coredamagehasoccurred."JulySSESFSAR18.1.20.3.2.5 states="exposures forareasnotcontinuously occupied(frequent andinfrequent occupancy) mustbedetermined casebycase,thatis,multiplythetaskdurationbytheareadoserateatthetimeofexposure."

SSESFSAR18.1.20.3.3.3 statesthat"GDC19isalsousedtogoverndesignbasesforthemaximumpermissibledosagetopersonnel performing anytaskrequiredpost-accident.

Theserequirements translate roughlyintotheob)ectives tobemetinthepost-accident reviewasgivenbelow.27I1992Page7 SafetyConsequences ofaBoilingSpentFuelPoolRadiation ExposureGuidelines Occupancy DoseRateObjectives Continuous l5mR/hrFrequent200mR/hrInfrecprent 500mR/hrAccessway 5R/hrDoseObjective 5Remforduration5Rem-allactivities 5RemperactivityInclinabovedoses"SSESFSAR18.1.20.3.4.3 statesthatthereviewresults"showthatthereactorbuildingwillbegenerally inaccessible forseveraldaysaftertheaccidentduetocontained radiation sources."

SSESFSARFigure18.1-4showsRoomI-105whereESWvalves153500/153501 arelocatedtobeinRadZoneVIIIwithdoseratesover5000R/hr.SSESFSARFigure18.1-6showsRoomI-514whereESWvalves153090A&B and153091A&B arelocatedtobeinRadZoneVwithdoseratesbetween5and50R/hr.ThesevalvesmustbemanuallyopenedtoinitiateESWmakeupto.thespentfuelpoolsinthelossoffuelpoolcoolingevent.PP&Ladministrative procedure NDI-6.4.3 specifies thatthewholebodydoseforlifesavingactions"shallnotexceed75rem"andthewholebodydoseforentryintoahazardous areatoprotectfacilities orequipment "shallnotexceed25rem."10CFR20'sALARAprovision requiresplantdesigntominimizeradiation exposure.

Application oftheemergency doseguidelines toadesignwhichrequiresmanualvalveoperation iscontrarytotheintentof10CFR20.1and10CFR50AppAGDC19.B.ConcernsTheESWsystemisrequiredtoprovidemakeuptothespentfuelpoolsfollowing lossoffuelpoolcooling.Eitheraseismiceventorlossofoffsitepowercanleadtolossoffuelpoolcooling.Bothconditions areassumedtooccurconcurrent withaLOCAintheDBAforcontainment analyses.

However,thepost-LOCA doseratesinthereactorbuildingareaswherethemanualvalvesarelocatedare5to5,000+R/hrandwillpreventthesevalvesfrombeing'ccessed withoutexcessive radiation exposuretotheoperator.

Inaddition, thereactorbuildingtemperature, humidityandemergency lightingconditions wouldnotbeconducive tothelocationandmanipulation ofmanualvalveswhichareusedinfrequently.

Therefore, themanualESWvalvemanipulations requiredformakeuptoboilingspentfuelpoolsmaynotbeaccomplished forallpostulated accidentconditions.

,July27I1992Page8 SafetyConsequences ofaBoilingSpentFuelPool3~Znaddition, sincetheboilingspentfuelpoolanalysisreportedinSSESFSARAppendix9Aassumedaseismiceventinitiated thelossoffuelpoolcooling,theintentional sheddingofnon-Class 1Epowerloadsinthereactorbuildingfollowing aLOCAwithoutaLOOPrepresents eitherthecreationofanevkindofaccidentortheincreased probability ofapreviously analyzedaccident.

EffectsofESWMakeupWateronReactorBuildingSystemsA.ReuatorReuireents'cesnCommtmetsandDesiBases10CFR50AppendixAGeneralDesignCriterion 4statesthat"structures, systems,andcomponents important tosafetyshallbedesignedtoaccommodate theeffectsofandtobecompatible withtheenvironmental conditions associated withnormaloperation, maintenance, testing,andpostulatedaccidents, including loss-of-coolant accidents."

StandardReviewPlan{NUREG-0800) 3.4.1statesthatthereviewof"plantfloodprotection includesallstructures, systemsandcomponents (SSC)whosefailurecouldpreventsafeshutdownoftheplantorresultonuncontrolled releaseofsignificant radioactivity..."andthatthisreview"alsoincludesconsideration offloodingfrominternalsources."

SSESFSAR6.3.1.1.3 statesthat,separation barriersforECCS"shallbeconstructed betweenthefunctional groupsasrequiredtoassurethatenvironmental disturbances suchasfire,piperupture,fallingobjects,etc.,affecting onefunctional groupswillnotaffecttheremaining groups.Inaddition, separation barriersshallbeprovidedasrequiredtoassurethatsuchdisturbances donotaffectbothRCICandHPCI."JulySSESFSAR9.1.3.3statesthat"thedesignmakeupratefromeachESWloop.isbasedonreplenishing theboil-offfromtheMNHLineachfuelpoolfor30daysfollowing thelossofFPCCScapacity."

MinutesfromBechtelmeetingonHVACsystems(February 1980)statesthatoriginalrequirement forSGTSwas"tohandlefumesfromaboilingfuelpool,"butthatSGTSwillnotbeabletohandlethismixturesincetheroomwillbecometoohot."Thisrequirement willbedeletedfromtheFSAR."AninternalPPELengineering workrequest{EWR830658,March1983)noted"condensation maybeexpectedfromthis27,1992Page9 SafetyConsequences ofaBoilingSpentFuelPoolevaporation whichvillrundovntoloverlevelsoftheR.B.Villthiscause'ossofessentialequipment, particularly electrical?

'asanevaluation beenperformed?"

Theresponsetothesequestions was"Thisisaninappropriate formattoaskquestions.

Commentsvererequested andnonereceived.

Furthermore, nobudgetexistsvithvhichtofundtheengineering timerequiredtorespondtothesequestions."

B.Concerns4oTheultimateheatsinkandESWaredesignedtoprovide1.5milliongallonsofwatertoeachspentfuelpooloverthe30dayperiod.IntheLOCA-LOOP condition, thereactorbuildingHVACsysteminZoneI,IIandIIIisolation moderecirculates refueling floorairthroughout allthreezones.Thewateraddedtothespentfuelpoolsendsupinthereactorbuildingfollowing boil-offandoverflow.

Theeffectsofthiswateronthesafety-related structures, systemsandcomponents inthereactorbuildings havenotbeenincludedindesignanalyses.

TheECCSandRCICroomcoolersareknownnottobedesignedforlatentheateffects.DampersintheSGTSandRB-HVACsystemclosewhentheenteringairtemperature exceeds165'F,whiletheboilingspentfuelpoolwascalculated toproduceairtemperatures of=1804F,Thepotential forcommonmodefailuresofmultipleECCSandsafety-related systemssuchasthestandbygastreatment systemexists.Failureofoneormoreofthesesafety-related systemscouldincreasetheconsequences ofpostulated accidents.

ReactorBuildingHeatLoadsA.ReulatorReuiementsLicensinCommitments andDesinBases10CFR50.49requiresthatelectrical equipment mustbequalified tothetemperature "forthemostseveredesignbasisaccidents.

"10CFR50AppendixAGeneralDesignCriterion 4statesthat"structures, systems,andcomponents important tosafetyshallbedesignedtoaccommodate theeffectsofandtobecompatible withtheenvironmental conditions associated withnormaloperation, maintenance, testing,andpostulatedaccidents, including loss-of-coolant accidents."

AninternalPP&Lengineering workrequest(EWR830658,March1983)noted"theinitialboilingratecorresponds to=3000cfmof2004vatervaporatoneatm.Istheequipment whichvillbeexposedtothisatmosphere qualified forit?"TheresponseJuly27,1992Page10 SafetyConsequences ofaBoilingSpentFuelPooltothisquestionwas"This,isaninappropriate formattoaskquestions.

Commentswererequested andnonereceived.

Furthermore, nobudgetexistswithwhichtofundtheengineering timerequiredtorespondtothesequestions."

APP&Lengineering report(SEA-ME-099, December1987)analyzedreactorbuildingtemperatures forLOCA,LOCA/LOOP andLOCA/false LOCAcasesassumingspentfueltemperatures remainedat125'F,butlistedasanonconservatism thatfuelpoolheatupintheLOCA/LOOP casewouldresultinhigherheatloadsfromtheRHRsystems,fuelpoolwallsandfuelpoolsurface.B.~CocerSecondary containment designanalysesarerequiredtoaccountforallheatloadsinthereactorbuildingincluding fromtheboilingspentfuelpool.Theexistingdesignreactorbuildingheatloadcalcsconsidersensibleheatfromtheboilingpool,butneglectlatentheat.Thesecalcsindicatelittlemargintoequipment qualification temperature limitsinmanyroomsforamaximumheatloadinthereactorbuildingofapproximately 5.5x106BTU/hr.Thetotaldesignheatloadfromthespentfuelpoolsis26.4x10BTU/hr,whichwouldaddatleastapproximately 20.9x106BTU/hrtotheexistingmaximumheatload.Eventhecurrentheatloadsinthespentfuelpoolscouldincreasethemaximumheatloadinthereactorbuildingby=504.=-Theremaining fiveconcernsraisedinEDRG20020involvednonconservatisms inanalysesfortheboilingspentfuelpoolevent.DZSCUSSZON OFOPPOSINGVIEWPOINT Thediscussions andmeetingswhichhaveoccurredsinceEDRG20020wasinitiated haveyieldedoneprimaryargumentagainsttheissuesraisedinEDRG20020havingnuclearsafetysignificance.

Thisargumentisthatthelicensing basesLOCA/LOOP accidentforSSESdoesnotassumeaboilingspentfuelpoolresulting fromtheevent.Inorderforthisassumption tobevalid,spentfuelpoolcoolingmusteithernotbelostormustberestoredpriortoboiling.Thereareseveralfaultsinthisassumption:

1)SincetheFPCCSandtheSWsystemarenon-safety relatedsystems,theircomponents arenotincludedintheequipment qualification programandmaynotsurvivethepressure, temperature, humidityandradiation environment inthereactoxbuildingfollowing apostulated accident.

Therefore, theJuly27,1992Page11

SafetyConsequences ofaBoil.ingSpentFuelPoolFPCCSwhichisdefinitely lostfollowing aLOCA/LOOP mayalsobelostfollowing aLOCAwithoutaLOOP.2)SincethefuelpoolcoolingassistmodeofRHRisanon-safety relatedfunction, itscomponents arenotincludedintheequipment qualification programandtherefore maynotsurvivethepressure, temperature, humidityandradiation environment inthereactorbuildingfollowing apostulated accident.

Inaddition, thefuelpoolcoolingassistmodeofRHRhasnotbeenutilizedsincetheinitialstartuptestingprogramanditsvalveswereremovedfromtheinservice inspection programseveralyearsagoandthevalvesmayhaveexperienced failureswhichhavenotyetbeendetectedwhichwouldpreventtheirsuccessful operation.

Therefore, thefuelpoolcoolingassistmodeofRHRmaybelostfollowingaLOCA/LOOP andaLOCAwithoutaLOOP.3)ThefuelpoolcoolingassistmodeofRHRrequiresthemanualopeningofvalvesinthereactorbuildingwhichmaybeinaccessible following apostulated accidentduetoradiation levels.4)FortheLOCA/LOOP case,ithasbeenarguedthattheSSESdesignimplicitly assumesrestoration ofoffsitepowertypically within24hoursandessentia.ally alwayswithin48hoursaftereventinitiation.

SSESFSARChapter8reportsPP&Lgridexperience insupportoftheserestoration times.However,nodocumentation wasfoundwhichstatesthatPP&LhasdefinedtheLOOPdurationfordesignbasesevents.AsEDRG20020andEDRG00005bothaddress,thespentfuelpoolmaybeginboilinginlessthan24hours.Inanycase,thereactorbuildingtemperature analysesforequipment qualification purposespresently counteranysuchcreditforrestoration ofoffsitepowersincenon-Class 1Epowerloadsinthereactorbuildingmaybeshed=24hoursafteroffsitepowerisrestoredinordertosatisfyroomtemperature limitations.

EDRG20020identified concernswiththeSSESdesignprovisions fortheboilingspentfuelpoolevent.TheSSESdesign,coupledwithcurrentoperating procedures, wouldhavesignificant nuclearsafetyconsequences ifalossofspentfuelpoolcoolingoccurred.

Therefore, theseconcernsmustberesolvedforSSES.Inaddition, manyoftheseconcernsareapplicable tootherBWRsandpossiblyevenPWRsintheUnitedStates.Therefore, theseconcernsmustbereportedtoINFO/NRCinorderfortheadversecondition toberemediedthroughout theindustry.

July27,1992Page12

Attachaent 9PPSLMemofromG.D.MillertoG.T.Jones,"FuelPoolCoolingDeficiencies",

Augustl8,1992(ET-0586)

Kote:ThismemobythePPSLSupervisor, Engineering Projectsprovidesanindication ofhowPP&Lnarrowedtheirscopeofevaluation fortheconcernsinEDRG20020tojustthedesignofthefuelpoolcoolingandcleanupsystem.Withtheexception oftheinstrumentation forthefuelpools,the.designofthefuelpoolcoolingandcleanupsystemhasnotbeenchallenged inEDRG20020and'tssubsequent supporting documents.

Theconcernsarethattheeffectsofboi1ingspentfue1poolson~h~esystemsandcomponents inthereactorbuildinghavenotbeenadequately

.analyzed.

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

SUBJECT:

FuelPoolCoolingDeficiencies Thefollowing actionsarebeingtakeninresponsetoconcernsraisedabouttheEORprogramandthefuelpoolcoolingissuesdescribed inEDRG20020andEORG00005.ERProcessChanesTheEDRprocessgoverning procedure, EPH-gA-122, willberevisedasfollows:2.Theappealprocessdescribed inparagraph 5.4willberevisedwiththefirststepoftheappealchangedtotheEngineering ReviewCommittee.

Subsequent appealmaybe.toeithertheHanager-NuclearEngineering, Superintendent

-SSES,orHanager-NSAG.Themanagement reviewdescribed inparagraph 5.14willberevisedtoinclude:a~b.PeriodicreviewofallinvalidEDRsbytheEngineering ReviewCommittee, andPeriodicreviewofallEDRsopengreaterthansixmonthsbytheEngineering ReviewCommittee.

FuelPoolCoolinOeficienc Resolution Engineering Technology hasresponsibility toresolvebothEDRs(EORG00005waspreviously assignedtoSystemEngineering).

TheseEDRsareassignedtoHarkHjaatvedt andarebeingworkedfulltimebyHichaelCrowthers.

TheEDREPH-101B, Rev.1 NEN0RANDUN(CONTINUATION SHEET)evaluations (safetysignificance, operability/reportability) arebeingdonebyJimAgnewandJoeZola.Ourinitialevaluation oftheseEDRshasconcluded thatthesafetysignificance isminimal.Thisisbasedprimarily onourunderstanding thatthedesignofthefuelpoolcoolingsystemwasspecifically reviewedandapprovedbytheNRCwithfullknowledge ofthefactthattheFPCCSwasnotasafety'elated systemandthatfuelpoolboilingcouldbeexpectedtooccurunderaspecificcombination ofhypothetical conditions.

However,itisnotyetcleartowhatextenttheNRC{ortheindustry) considered thelong-term effectsofthefuelpoolboilingcondition.

Therecordonthissubjectisconfusing andfurthercomplicated bychangestothefueldesignandactualoutagepractices whichhave'notbeenaccounted forintheFSARanalysis.

Mebelievethatthedesignandprocedural featureswhichexisttodayprovideareasonable levelofassurance thattheactualsafetyconsequences areminimized.

However,procedure enhancements andadditional operatortrainingareclearlyrequiredaspartoftheresolution oftheseconcerns.

Thisevaluation willbefullydocumented aspartoftherevisedEDRpackage.Afinalevaluation ofthisconcernispredicated oncompletion ofahistorical reviewofallavailable documentation.

Thus,ourplanforresolution includes:

I.Completeinvestigation ofhistorical designandlicensing information, including requestsforinformation fromtheoriginaldesignorganizations (GEandBechtel),

2.Establish thefuelpoolandfuelpoolcoolingsystemdesignbasisbasedonthederiveddesignbasisandcurrentoperating

practice, 3.4,5.7.8.Reviewfuelpooldesignsofotherboilingwaterreactors, Completeanewanalysisofthefuelpoolandfuelpoolcoolingsystembasedontheestablished designbasis,Prepareapoint-by-point comparative description ofourcurrentoperating practiceanddesignbasisagainsttheoriginalFSARanalysis{including theindividual issuesidentified intheEDR),Listandassesseachdeviation fromtheoriginalanalysisasdescribed initem5,Prepareanoperability evaluation accounting foreachdeviation asadditional information becomesavailable, Re-evaluate allissuesforreportability

{ongoing),

Preparerecommendations to,resolve eachissuedesc}ibedinitem4.EPN-IOIC, Rev.I{51)

Page3EN0RANDU(CONTINUATION SHEET)Weplantokeeptheoriginators oftheseconcernsinformedofourprogressasweworkourwaythroughthiseffort.Aformalplanincluding schedulefortheaboveactivities isunderdevelopment.

IndeendentReviewbSstemsAnalsisSystemsAnalysis(KevinBrinckman) isintheprocessofconducting anindependent, designreviewoftheseissues.Additionally, Ihaverequested theirreviewofthisissuefromanIPEperspective whenresources becomeavailable.

Assessment ofEDRProcessAsafollowupactivityIplantorequestanassessment oftheEDRprocessfromanindependent organization.

Thisassessment willfocusspecifically onthevalidation andverification stepsoftheprocess.Thisshouldbeconducted byNSAG.NgAhasonceinthepastconducted anauditoftheprocess.Theydonotgthtd~iitiiydf'lli.Thydfi.ydiscrepancy tobeacondition adversetoquality,whereasourprogramrecognizes thepotential fordiscrepancies indocumentation whichdonotconstitute actualdeficient conditions.

Otherprogrammatic auditshavetakenplaceontheEDRprocess,butnonehaveexaminedthephilosophy orcriteriausedtodetermine thevalidityofengineering issues.EPN-101C, Rev.1(51)

Attachaent 10PP&LMemofromO.C.PrevattetoG.T.Jones,"FuelPoolCoolingOeficiencies",

August20,1992(ET-0587)

MEMORANDUM TO:FROMJOB:NUMBER

SUBJECT:

G.T.JonesA6-2D.C.PrevatteA6-3Engineering Technology ET-0587REPLY:FuelPoolCoolingDeficiencies DATE:August20,1992FILE:A45-1Acc:Distribution Corres.FileA6-2ETFileA6-3ThismemoiswritteninresponsetoMr.G.D.Miller'smemoET-0586of8/18/92concerning

+hedis"epanciesassociated w-'ththefuelpoolcoolingsystemdescribed inEDRsG20020andG00005.Mr.Miller'smemostatesthat,"Ourinitialevaluation oftheEDRshasconcluded thatthesafetysignificance isminimal."

Istronglydisagreewiththisevaluation andIherebyrequestthatthesafetysignificance oftheseEDRs,particularly EDRG20020bereevaluated forthefollowing reasons:1.Theprimarybasisgivenfor'hisconclusion isthat"...thedesignofthefuelpoolcoolingsystemwasspecifically reviewedandapprovedbytheNRCwithfullknowledge ofthefactthattheFPCCSwasnotasafetyrelatedsystemandthat'uelpoolboilingcouldbeexpectedtooccurunderaspecificcombination ofhypothetical, conditions."

Iconsiderthisbasistobeinvalidforthefollowing reasons:a~b.ThisbasisappearstomissmostofthemainpointsofEDRG20020.Itfocusesonthenon-safety relatedFPCCSwhichisnottheconcern.TheprimaryconcernsarewiththeNRCmandated(Reg.Guide1.13),safety-related backupcoolingschemeofallowingthefuelpooltoboilandproviding makeupwaterfromthesafety-related ESWsystem.Theconcernisthepotential inability oftheoperators toputthisschemeintoeffectbecauseofinaccessibility totheassociated valvesduetopost-LOCA radiation levelsinthereactorbuilding, andthepotential negativeeffectsofaboilingspentfuelpoolonvirtually allofthesafety-related systemsinthereactorbuilding, effectswhichhavenotbeenanalyzed.

The"...specificcombination ofhypothetical conditions

..."referredtointhememoisLOCA/LOOP.

Thisisnotsomeoff-the-wall accidentscenarioastheresponseseemstoimply.Thisisthestandard, universally recognized, NRCmandateddesignbasisaccident(DBA).

G.T.JonesFuelPoolCoolingDeficiencies August20,1992Page22.Theconditions ofconcernarenotpostulated.

Theyaremechanistic consequences ofthatDBA.Thememoalsocitesasanotherbasis,confusion concerning whatwasoriginally considered inthedesign,thechangestothefueldesign,andoutagepractices whichhavenotbeenaccounted forintheFSARanalysis.

ThisbasiswouldseemtosupporttheEDRscontentions, notrefutethem.Ifindeedthereisconfusion onthesesubjects, then,atbest,thecondition isunanalyzed andtherefore bydefinition inNRCregulations andourprocedures, asafetyconcern.Althoughthisinformation iscertainly pertinent toahistorical perspective oftheseconcerns, todetermination ofthemagnitude oftheheatloadsinvolved, andtoformulation ofthecorrective actionsthatmaybeeffected, itisnotpertinent totheabilityoftheplanttoperformasrequiredfortheDBAconditions.

Theinformation tomakethisdetermination isclearandavailable today.3~Anotherbasiscitedisthat"...thedesignandprocedural featureswhichexisttodayprovide.areasonable levelofassurance thattheactualsafetyconsequences areminimal."

Thereisnoelaboration onwhatthesedesignandprocedural featuresare.Inconversations withMr.MillerandotherswhoseemtoconsidertheEDRsashavingverylowsafetysignificance, nodesignorprocedural featureshavebeencited.Theonlyfeaturesthathavebeencitedare"heroicaction"oftheoperators, theEOPs,anEOCstaffwhowillunderstand theconcernanddowhateverneedstobedone,andalowprobability ofoccurrence.

Thesearenotvalidfeatures.

Heroicoperatoractionisnotavalidbasisforthedesignofaplant,noraretheEOPs(even'ftheywerecorrectinthisarea)whichaddressmanyconditions potentially outsidetheplantlicensing and/ordesignbases.And,contrarytothememo'scontention, theEOPsastheystandtodayarenotcorrect.Theycurrently telltheoperatorhehasaminimumof25hoursuntilthefuelpoolboils.Underworstcaseconditions, itmaybelessthanhalfthattime;andwiththeLOOP'conditions, hehasnoinstrumentation totellhimthecondition ofthefuelpool.UnderDBAconditions, theoperatorisflyingblindusingnonconservative information.

Additionally, currentEOPsmovetheplanttowardtheconditions ofconcern,notawayfromthem.ThecurrentEOPsrequiredeenergizing thenon-1Eloadsinthereactorbuilding

~~G.T.JonesFuelPoolCoolingDeficiencies August20,1992Page3att=24hoursifreactorbuildingtemperatures areasanalyzed.

This,ineffect,imposesaLOOPonthereactorbuilding, thusinitiating theconditions ofconcern.Theknowledge oftheEOCstaffisalsonotavalidfeatureiftheconditions of.concernarenotformallyaddressed inanyofficialdesignand/orprocedural documents.

-Although itisclaimedthattoday'sstaffwouldunderstand theconcerns, thereisnoreasontobelievethisistruesincetheconcernsaren'tdocumented outsidetheEDRsandthereisnotrainingonthiseventuality.

Andtenyearsfromnow,iftheconcernsarenotformalized inwriting,theywillbeevenlessunderstood.

Additionally, evenifthestaffdoesunderstand, iftheconditions arenotanalyzed, whichtheyarenot,theplantcouldbebroughttoacondition whererecoveryisnotpossibleinspiteoftheirfullunderstanding.

Lowprobability isalsonotavalidfeature.discussed indetailfurtherinthismemo.Thisis4~5.Thestatement inthememoregarding theNRC's"...fullknowledge ofthefactthattheFPCCSwasnotasafety-related systemandthatfuelpoolboilingcouldbeexpectedtooccurseemstoimplythatiftheNRCapproveditasis',thatmakesitacceptable evenifwediscoverdiscrepancies thatmaynot,havebeenoriginally considered.

Iamawareofnoevidencethatindicates theNRCapprovedofourdesignwiththeunderstanding that:(a)theoperatorwouldbeexposedtounacceptable radiation levelsunderdesignbasisconditions ineffecting theFSARdescribed fuelpoolboilschemeforalternate cooling;and(b)thattheboilingfuelpoolmightcreateamyriadofunanalyzed conditions inthereactorbuildingthatcouldthreatentheoperability ofmanyofthesafety-related systemsinthebuilding.

Thememoconcludes thatthesafetysignificance is"minimal."

Perprocedure EPM-703,Rev.0,Section5.3,"...a'minimal'lassification generally signifies adocumentation typeofdiscrepancy."

Znotherwords,notarealengineering concern,but'ather adocumentation errorthatcanberesolvedbymakingeditorial changestothedocuments.

Perthisprocedure, ifanEDR'ssafetysignificance isclassified as"minimal",

itdoesnotevenhavetobeevaluated foroperability andreportability.

TheseEDRsarenotinanyreasonable evaluation justadocumentation discrepancy.

Theyarefundamental engineering concernsraisedbytwoengineers intimately familiarwiththesystemsafterexhaustive research.

Todismisstheseconcerns G.T.JonesFuelPoolCoolingDeficiencies August20,1992Page4byclassifying themasjustadocumentation discrepancy isludicrous.

Ifconcernssuchasthesedon'tevengettothestageintheprocesswheretheyarerequiredtobeevaluated foroperability andreportability, concernswhichinvolvethesafetyoftheoperators andpotential threattovirtually everysafety-related systeminthereactorbuilding, thenwhatdoesittaketotriggeroperability andreportability evaluations?

Thethreshold appearstobemuchtoohigh.6.Thememo'sreference to"...aspecificcombination ofhypothetical conditions

..."impliesaprobabalistic argumentastowhythesafetysignificance is"minimal."

Indeed,inconversations withMr.Millerandothersthisargumenthasbeenexplicitly raised.Thisargumentisnotvalidwithregardtodesignbasesforseveralreasons.First,ourdesignbasisconditions ofLOCA/LOOP whichproducetheconditions ofconcernaremandatedbyregulation.

That,fordesignpurposes, dictatesaprobability of1.Second,evenforLOCAwithoutaLOOP,ourcurrentEOPsdictateaself-imposed LOOPonthereactorbuildingat24hours,againmakingtheprobability forLOCA/LOOP equall.Third,evenforaLOOPorFPCCSsystemfailurewithoutaLOCA,theconsequences offuelpoolboilareunanalyzed.

Fourth,EDRprocedure EPM-703,Rev.0,Section5.3,hasasacaution,capitalized, boldlettersandunderlined asfollows,"TheEDMGEvaluator mustnotputheavyemphasisontheperceived smallprobability ofoccurrence ortheexpectedsatisfactory outcomeofanalysisorreanalysis tojustifycontinued operation withtheexistingdiscrepancy."

Section5.4goesontosay,"SAFETYSIGNIFICANCE mustbebasedonthepotential adverseconsequences offailures, eventhoseofverylowprobability."

Thus,byourprocedures, potential consequences shouldbethedominantfactorinevaluating safetysignificance, notprobability.

Thepotential consequences oftheconcernsraisedintheseEDRs,andsubsequent documentation generated byMr.Lochbaumandmyself,areverygrave.TheEDRprocessatPP&Lwasdeveloped inresponsetoa1990SALPinspection findingthatsafetysignificant issueswerenotbeinghandledinatimelymanner.OurEDRprocedures arefilledwithwordsthatreflectthisconcern;wordslikequickly,expeditiously, immediately, early,timely.Forthestepwherewearetoday,the"screening" step,theprocedures'EPM-703, Rev.0,Section5.2)

G.T.JonesFuelPoolCoolingDeficiencies August20,1992Page5intentisthatEDRsbe"quickly" screenedafteradiscrepancy enterstheEDRprocess.Asoftoday,theofficialscreening stillhasnotbeencompleted fourmonthsaftertheEDRenteredtheprocess,andapproximately onemonthafterMr.LochbaumandIpersonally broughttheseconcernstoyourattention.

Neithertheintentoftheprocedure northeintentoftheNRCarebeingfulfilled.

TheplanoutlinedinMr.Miller'smemoforthe"finalevaluation" wouldappeartofurtherdelaytherequiredactions.Althoughalloftheactivities intheplanareimportant tounderstanding theproblemsmorecompletely andeffecting themosteffective

olutions, noneofthemareprerequisites forperforming avalid"screening",

and.mostofthemarenotrequiredtodetermine operability andreportability.

Tomaketheseactivities prerequisites forafinal"screening" evaluation andthenfortheoperability andreportability determinations, istofurtherdelaytheprocessunnecessarily.

Theinformation isavailable tomakethesedeterminations today,andtheyshouldbemadeimmediately ifwearetodowhat'slegitimately requiredofus.Ihavemademyownoperability andreportability determinations basedonextensive researchontheseconcerns.

Atbest,theoperability ofthefuelpoolcoolingintheboilandfeedmode,thefuelpoolinstrumentation, andmuchofthesafety-related equipment inthereactorbuildingisunanalyzed withregardtotheeffectsoftheboilingfuelpoolonthisequipment, withstrongindications that,analysiswouldshowit.asinoperable.

Ifthisisthecase,per10CFR50.72 and50.73,itisreportable.

Iwouldwelcomeanyhard,definitive, documentary information indicating thatmyconclusions arewrong.BothMr.LochbaumandI,andforthatmatter,manyotherswhowouldliketoseedifferent conclusions, havesearchedforcontraryevidence.

Tothebestofmyknowledge, nonehasbeenfound.kThisisnottosaythattheplantshouldnecessarily beshutdown.Ibelievethatverycrediblearguments canbe,madeforaJ.I.O.Itherefore don'tunderstand whythereissuchanapparentreluctance intheorganization toacknowledge theseconcernsandmoveaheadwithresolution expeditiously.

Althoughresolution willhaveacost,certainly, thatcostdoesnotnecessarily havetoincludeplantshutdown.

Itherefore stronglyurgethattheformalscreening evaluation andtheevaluations oftheoperability andreportability oftheseconcernsproceedwithout,furtherdelaywithpriorityoverallotheractivities inMr.Millersplan,andthatweexpeditiously getonwiththeprocessofr'esolving theseconcerns.

G.T.JonesFuelPoolCoolingDeficiencies August20,1992Page6I.sincerely appreciate yourcontinued personalattention inthesematters,andIamatyourserviceinaddressing theseconcerns.

DISTRIBUTION:

J.E.F.G.R.G.M.H.G.D.G.J.D.A.AgnewButlerByramCrowthers GogatesKuczynski LochbaumA6-3A6-3A6-1A6-3SSESSSES,S&AEnerconG.D.MillerJ.R.Mittenberger M.R.Mjaatvedt C.A.MyersJ.G.ReflingJ.S.StefankoT.J.SweeneyJ.A.ZolaA6-3A6-1A6-3A2-4A6-3A9-3SSESA6-3FUELPOOL.DCP/kbw Attachaent 11PP8LMemofromA.DyszeltoT.C.Dalpiaz,"U2RI05FuelPoolDecayHeatEvaluation",

August21,1992(PLI-72230)Note:Thislettertransmits interimguidancetotheSSESsitepersonnel foruseduringanupcomingrefueling outage.Thisguidanceisnecessary becauseEDRG00005,initiated inSeptember 1990,hasnotyetbeendispositioned andtheapplicable discussions inFSARSection9.1andAppendix9Aareno-longeraccurate.

18-22-1992 15:57P.82z84'UegestZ3g3992T.t.OalpfazSSES...-g<>~.!>rl'~sg'gqhlily>(breSUSgUEHNNA STGNELECTRICSTATION02RI05FUELPOOLDECA'IHEATBALNTIOHCCH741687FILEeAI~"w7

References:

I}PLI-8?533, "FuelPoolCoolingHeatLoads-KOR600005,'prfl IZ,1991.2)PLI-70395,

'Ul8106FuelPoolDecayHeatEvaluation,"

February7,1992.3}ET-0585,"FuelpoolCaalfngOeffciencfes,"

8/18/92.ThismemoprovidesshorttarerelieffortheopenEOR,600005,{Ref<<rence 1}withrespecttoCheupcoofngNSRIObyproviding NFK'sevaluation aftheresultfna Ciseconstraints forperforaance afcoaaoaRHRsystemoutagework,similar4theU1RI05evaluation Neference 2}.Alongtemsolutianto.thisEORisrequiredtoensurefuturesuccessful, Cfeelyauiages.fnshort,theU25RIDevaluatian showsnachangeinihecurrentoutageschedule(f.~.,Sept.28forcoamonRHRsysteiwork}fornafuelfailuresinQnft8Cycl~S.However,futureevaluations, whichwillinvolvehigherheatloadsandaddressChepotential forfuelfailure(s),

willlikelyaffecttheoutageschedule.

Reference 3providesadescr)ptian ofthelongCeresolutfantothisproblem.3QLXFSARSectionS.Adescribes theradiological releaseresultsfroaalossaffuelpoalcoolingevent.111'ssuaptfons usedforCheFSNlanalysisinclude4carereloads,incarefuelshuffling, andaaaxfeuafuelexpasureof28,500ND/NTM.Thecurrentaperation atSusquehanna SESincludesafuelreloadbatchsizeotaaoroxfiately Wofihecore,amaxfeulfueldischarge expasureafl0,001i%8/OU,andafullcoreoffloadforeachoutage.Ifonearmorefuelfeflureseresuspected iohaveoccurredduringthepperating cyclejustprfartaanoutageordurinofuelhandlingaft<<rshutdown, analyses-oust b<<performed toassuretheradio'logical releasefreethepastulated lassoffuelpoolcoalfngeventarelessthanthosepresented inCheFSAR.TheFSARanalysesareboundingprovidedthatcateeonRHRsysteeoutageworkisnotstarteduntilthedecayheatlave'lislowenoughtopreventfuelpoolhailingfnlessthan25hours.Ifnafuelfailuresaresuspected tohaveoccurredduringiheop<<retina cyclejustpriortoanoutageorduringfuelhandlingaftershutdown, analyseserstbeperformed toassurethefuelpoolwaterievelcanbeaafntafned duringalassoffuelpoolcoolingevent.Thefuelpool iO-22-iGQ2 i5:58P.03r84waterlevelCaaheeaiatatae4 previdedthate~NOSgatmeugeneWrhiahOCStartersutilQe-CNmelee'lot patetethespehtfueipeeltle.o40CPll)isgreaterthanthespentfuelpoolboilingratederringthelossoffuelpoolcoo'lingevent.Toaddressthisissuefortheupcomingoutage.NuclearFuelsEngineering hascalculated thetotaldecayheatofthefuelinthespentfue)poolsfortheU25RIQconsistent withtheapproachinReference 2.Thisdecayheatleva)includesatotalofthedecayheatfroothefuelintheUIpool,U2pool,andthefullcoreoffload.F)gurelshowsthecalculated spentfue)pooldecayheatasafunctionoftimeaftershutdown.

Thecurvelabelled'nominal's acalculation ofthedecayheatbasedonthemethodolag'y inNlRKG-OSQO.

Thismethodology hasbeenshowntoproducehigherdecayheatlevelsthanthemorerigorousmethodology intheAHSS.S-I919decayheatstandard.

Thecurvelabelled"maximum's alsobasedonthemethodo'logy inNUREG-0800 butaccountsforuncertainty inthereactorpowerlevel(lo}anduncertainty inthedecayheatmethodology.

NuclearFuelsEng1neerino hasalsoperformed acalculation todetermine.

CheCfmeaftertheU2t3shutdownthatthespentfuelpoolboilingrateduringapostulated lossofspentfuelgalcoolingevent1slessthanthe60GNENmakeupflowrate.BasedonChe"aaximum" decayheatcurveinf1gureI.aspraypondteeperature ofSO'F,andopenfuelpoolgates.thefuelpoolboil1ngrateduringapostulated lossoffuelpoolcoolingeventislessthanthe60OPNESMmakeupraCesubsequent to)4daysafterreactorshutdown.

Therefore, HFE'sevaluation indicates thatprovididfuelfa11uredoesnotoccurduringtheremaining V2C5operation orduringfuelhandlingaftershutdown, coslonRHRsystemoutageworkshouldnotstartunC11atleast14daysafterreactorshutdown.

[fafuelfa1lureoccurs,acalcu1ation shouldbeperformed todetermine iffurCheroutagerestrict1ons arenecessary.

Notethattheabovecalculations havebeendocumented 1nNFE-B-NA-OhS.

Rev.2andindependently reviewedinaccordance withqAprocedures EN-N-301.

The)4darestr1ction oncottisencement ofcoamonRHRsystemworkdoesnotimpactthecurrentURIRKEDoutageschedule.

A.DysxelNuclearfuelmanagement Pro)octEngineerNuclearFuelsEngineering AD/elmel311a.ad cc: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 AttachIIent 12PP8LMemofromJ.M.KennytoG.T.JonesandC.A.Myers,"EDRonFuelPoolCooling",

August25,1992Note:.This'confidential'emo isthefirstdocumented indication thattheNRChadbeeninformally notifiedoftheconcernsraisedinEDRG20020.

~~~QQNF1QQQTIAL August25,1992G.T.JonesC.A.MyersA6-2A2-4EDRONFUELPOOLCOOLINGOnAugust24,1992IbriefedbothScottBarberandJimRaleighoftheNRConthestatusofourreviewofcontractor originated fuelpoolcoolingconcernsdocumented onanEDR.Inotedthatourcurrentpositionwastherewerenoimmediate concernswithsystemoperability orneedforreportability underregulations identified butthatoureffortswerecontinuing toaddresstheidentified issues.IalsonotedthatGeorgeJoneshaddiscussed theconcernswiththecontractors andwaspersonally involvedinresolving theissues.Ihadpreviously briefedJimRaleighinJulyofthefuelpoolconcernsandreviewsbeingperformed; Scottdidbringtomyattention anopeninspector findingconcerning theHaddam¹ckfuelpooldraindown eventandsubsequent effortsbyNSAGonfuelpoolissues.Henotedtherewere28openitemsandthatweshouldreviewtheseissuesforstatus.Iindicated itwasmyunderstanding Engineering wouldbeaddressing theNSAGopenissuesonthefuelpoolaspartoftheirefforttoresolvetheopenEDR.k%.M.KennyCC:J.E.AgnewA6-3G.D.MillerA6-3J.R.Miltenberger A6-1R.R.SgarroA2-4H.G.StanleySSESJMK:tahFuelPool.

EDR

Attachment 13PP8LMemofromGeorgeT.JonestoGlennD.Miller,"FuelPoolCoolingEDR's620020,G00005",August27,1992(PLI-72267)

~~~ppp<<y<<pp;.,0p<<{RAugust27,1992GlennD.MillerA6-3SUSQUEHANNA STEAMELECTRICSTATIONFUELPOOLCOOLINGEDR'SG20020,G00005PLI-72267 FILE'45-I A

Reference:

ET-0587,ET-0586Thereference lettersshowmethattherestillisadifference ofprofessional opinionrelativetothesignificance ofthesubjectEDR's.Thisdifference istoberesolved.

Thisissueistobeworkedexpeditiously untilwehaveresolvedtheoutstanding questions.

IwishtopointoutthatourbeliefthatadesignhasbeenreviewedandapprovedbyNRC,isnotadequatejustification forclassification ofthesignificance ofanissue.Theissuemuststandonit'sownmerits.Iamfurtherconcerned thatouractualconfiguration andmethodofoperation apparently differsfromthatdescribed intheFSAR..TheFSARisourlicensedbasesandanydeviation fromthatdescription isrequiredtohaveathoroughandcompletedocumented evaluation onfile.Thereweretwenty-eight openitemsresulting fromNSAGReviewofFuelPoolCooling.Theseneedtobeincludedinthisrevie'w.Iwishtohavethescheduleforresolution ofthisissueaccelerated andtheclassification ofthesignificance ofthisissuereevaluated.

Iamexpecting atleastdailyupdatesofourprogress.

Ifyouhavequestions, pleasecallme.>AMGeorge.onesAttachment CC:J.E.F.G.R.G.M.H.G.D.G.J.D.A.S.M.AgnewButlerByramCrowthers GogatesKuczynski LochbaumHausemanA6-3w/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.PrevatteMiltenberger Hjaatvedt MeyersRef1ingSweeneyZolaRec.FilesA6-3w/aA6-Iw/aA6-3w/aA2-4w/aA9-3w/aSSESw/aA6-3w/aA6-2w/oc:Xvp51%docs%2002M5.sgt 8/26/92 Attachaent 14PP8LMemofromGlenn0.MillertoGeorgeT.Jones,"FuelPoolCoolingEDRs620020,G00005",August.31,1992(PLI-72297)

~~August31,1992GeorgeT.JonesA6-2SUSQUEHANNA STEAHELECTRICSTATIONFUELPOOLCOOLINGEDRsG20020,G00005PLI-72297FILEA45-I

Reference:

PLI-72267, ET-0587,ET-0586InresponsetoyourletterPLI-72267 wearecontinuing toworktoresolvetheissuesinthereferenced EDRs.AsIexplained toyoupreviously ImetwithHr.Prevatteanddiscussed hisconcernsatlengthonAugust21.Weacknowledged ourdifferences andagreedtocontinueworkingtowardresolution.

Iwanttoreemphasize toyouthatwearenotusingthepriorreviewandapprovalofoursystemdesignbytheNRCasabasisfortheclassification ofthesafetysignificance ofthisissue.Statements whichImadeinET-0586relativetothesafetysignificance wereintendedtosummarize theEDMGpositiononscreening.

Thereference totheNRCisonlyastatement ofthefactthatourdesignchilosophy atthetimeoflicensing wasreviewedandapprovedbytheNRC.Thispositioninfactconstitutes ourlicensing basis.TheFSARcontainsreferences toanalysesregarding theFuelPoolCoolingandCleanupSystemandtheFuelPool.Itdoesnotdescribetheexactmannerinwhichweoperate'the plant.OurcurrentfueldesignandfuelcycledeviatesfromtheFSARdescription.

ThisisthesubjectofG00005.Ouroutagepractices differfromthedescription intheFSAR.ThecurrentoutagepracticeisthesubjectofaperiodicanalysisdonebyNuclearFuelsforeachrefueling outage.Wehavereviewedthetwenty-eight "openitems"fromtheNSAGreview.Twenty-six ofthetwenty-eight itemswereresolvedtothesatisfaction ofNSAG.Theremaining twoitemsrefertotheneedforthelevelandtemperature indication tobeavailable inthecontrolroomviaaPHS(computer display)formatandtoaddreflashcapability foralarmsfrompanelOC211.Thesemodifications areonthebooksbutnotbeingactivelyworkedtothebestofmyknowledge.

EDMGcompleted arevisiontotheEDRscreening forG20020onFridayAugust28,1992andrequested comments.

Thesignificance wasevaluated asminimal.Basedonmyreviewofthisscreening documentitisunacceptable aswrittenandIhaverequested itberevised.Weareproceeding toreviewtheissueforreportability regardless ofthefinalsignificance levelfromthescreening review.Workonresolving theissueisassignedtoHarkHjaatvedt.

MichaelCrowthers hasbeenworkingonthisissuesinceJuly20,1992.IhavealsoassignedDaveKostelnik asoftoday.WeareplanningtoinvolveBechtelandGE.Ascheduleisunderdevelopment.

August31,1992PLI-72297FILEA45-1ASystemsAnalysis'ndependent evaluation willbecompleted thisweek.Wewillfactortheirevaluation intoourongoingwork.Iwillreportontheirresultswhenavailable.

Iwillcontinuetokeepyouapprisedofourprogressonadailybasis.GlennD.Millercc:J.E.AgnewF.G.ButlerR.G.ByramM.H.Crowthers G.D.GogatesG.J.Kuczynski 58@RZcdg~ayyp

'.-S.M.HausemanA6-3A6-3A6-IA6-3SSESSSES~4'a'.~U~

• ~":iS45con'6-2 D.C.PrevatteJ.R.Miltenberger M.R.Mjaatvedt C.A.MyersJ.G.ReflingJ.S.StefankoT.J.SweeneyJ.A.ZolaNuclearRecordsA6-3A6-1A6-3A2-4A6-3A9-3SSESA6-2 Attachment 15PP8LMemofromKevinM.Brinckman toGeorgeT.Jones,"ReviewofFuelPoolCooling",

September 1,1992(PLI-72288)

Note:Thisengineering reportwaspreparedbyaPPALengineerpreviously notassociated withEORG20Q20attherequestofthePP8LManagerofNuclearPlantEngineering toprovidehimwithanindependent appraisal oftheconcernsraisedintheEOR.Thisindependent evaluation basically concludes thataLOCAwithalossofnormalfuelpoolcoolingwouldputtheoperators "inapositionwheretheywouldberequiredtomakedecisions onremovingECCSequipment fromcontainment/core coolingservicetocoolthefuelpool"andpointsoutthatitwouldinvolveunanalyzed conditions.

Thisreportalsoraises,forthefirsttime,theconcernthatthehydrodynamic loadsoftheLOCAmightdamagethenon-seismic, non-safety relatedfuelpoolcoolingsystempiping.