ML18026A537

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Forwards FSAR Change Delineating Use of RHR Fuel Pool Cooling Mode of Operation to Mitigate Loss of Normal Spent Fuel Pool Cooling Sys in Response to Seismic Event,Per Commitment Made Via 941228 Ltr
ML18026A537
Person / Time
Site: Susquehanna  Talen Energy icon.png
Issue date: 02/21/1995
From: BYRAM R G
PENNSYLVANIA POWER & LIGHT CO.
To:
NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
PLA-4273, NUDOCS 9502270258
Download: ML18026A537 (56)
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PR.I(3RIEY1(ACCELERATEDRIDSPROCESSIXREGULATORYINFORMATIONDISTRIBUTIONSYSTEM(RIDS)ACCESSIONNBR:9502270258DOC.DATE:95/02/21NOTARIZED:NOFACIL:50-387SusquehannaSteamElectricStation,Unit1,Pennsylva50-388SusquehannaSteamElectricStation,Unit2,PennsylvaAUTH.NAMEAUTHORAFFILIATIONBYRAM,R.G.PennsylvaniaPower&LightCo.RECIP.NAMERECIPIENTAFFILIATIONDocumentControlBranch(DocumentControlDesk)

SUBJECT:

ForwardsFSARchangedelineatinguseofRHRfuelpoolcoolingmodeofoperationtomitigatelossofnormalspentfuelpoolcoolingsysinresponsetoseismicevent,percommitmentmadevia941228ltr.DISTRIBUTIONCODE:AOOIDCOPIESRECEIVED:LTRlENCL3SIZE:5TITLE:ORSubmittal:GeneralDistributionNOTES:DOCKETN050003870500038805000387RECIPIENTIDCODE/NAMEPDl-2LAPOSLUSNY,CINTERNAL:ACRSNRR/DRCH/HICBNRR/DSSA/SRXBOGC/HDS2EXTERNAL:NOACNOTES:COPIESLTTRENCL11116611111011RECIPIENTIDCODE/NAMEPD1-2PD/D/NUDOCS-ABSTRACTNRCPDRCOPIESLTTRENCL1111111111NOTETOALL"RIDS"RECIPIENTS:PLEASEHELPUSTOREDUCEO'ASTE!CONTACTTIIEDOCL'ifENTCONTROLDESk,ROOAIPI-37(EXT.504-0033)TOELIXIINiATEYOURNAiILFROifDISTRIBUTIONLISTSI'ORDOCI.'4IEN'I'SYOL'ON"I'L'I'.D!TOTALNUMBEROFCOPIESREQUIRED:LTTR18ENCL17

~0PennsylvaniaPower8LightCompanyTwoNorthNinthStreet~Allentown,PA18101-1179~610/774-5151FEB211995RobertG.ByramSeniorVicePresident-Nuclear610/774-7502Fax:610/774-5019U.S.NuclearRegulatoryCommissionAttn.:DocumentContr'olDeskMailStationP1-137Washington,D.C.20555SUSQUEHANNASTEAMELECTRICSTATIONFSARCHANGE:RHRFUELPOOLCOOLINGDocketNos.50-387and50-388

Reference:

PLA-4230,RG.ByramtoUShfRC,"LossofSpentFuelPoolCoolingfromSeismicEvent/UseofRHRFuelPoolCoolingMode",datedDecember28,1994.

DearSir:

Viathereferencedletter,PP&LcommittedtoprovideanFSARchangedelineatingtheuseoftheRHRFuelPoolCoolingmodeofoperationtomitigatethelossofnormalspentfuelpoolcoolingsysteminresponsetoaseismicevent.AcopyoftheFSARchangeisattachedforyouruseandinformation.Althoughthischangehasbeenreviewedandapprovedinternally,PP&ListreatingthischangeaspreliminarypendingissuanceofthefinalNRCSafetyEvaluationonSpentFuelPoolCoolingissues.Uponissuanceofthatdocument,wewillresolveanydiscrepanciesandformallyissuetheFSARchangeperournormalprocedures.Ifyouhaveanyquestionsontheattachment,pleasecontactMr.J.M.Kennyat(610)774-7904.Verytrulyyours,iR.G.yraAttachmentCC:NRCRegionIMs.M.Banerjee,NRCSr.ResidentInspector-SSESMr.C.Poslusny,Jr.,NRCSr.ProjectManager-OWFNMr.J.Shea,NRCProjectManager-OWFNIDR950227ADOCK05000>8PDP NOTE:Pagenumbersinparenthesis(Iindicateaspill-overfrompreviouspages.TheydonotcoincidewiththetextonthatpageintheFSAR....9502270258 SSES-FSARaveragelifeexpectancymanytimestheresidencetimeofafuelloading.1.2.2.3.2ReactorVesselandInternalsThereactorvesselcontainsthecoreandsupportingstructure;thesteamseparatorsanddryers;thejetpumps;thecontrolrod,guidetubes;distributionlinesforthefeedwater,corespray,andstandbyliquidcontrol;theincoreinstrumentation;andothercomponents.Themainconnectionstothevesselincludethesteamlines,thecoolantrecirculationlines,thefeedwaterlines,thecontrolroddrivehousings,andtheECCSlines.Thereactorvesselisdesignedandfabricatedinaccordancewithapplicablecodesforapressureof1250psig.Thenominaloperatingpressureis1020psiainthesteamspaceabovetheseparators.Thevesselisfabricatedofcarbonsteelandiscladinternallywithstainlesssteel(exceptforthetopheadwhichisnotclad).Thereactorcoreiscooledbydemineralizedwaterthatentersthelowerportionofthecoreandboilsasitflowsupwardaroundthefuelrods.Thesteamleavingthecoreisdriedbysteamseparatorsanddryers,locatedintheupperportionofthereactorvessel.Thesteamisthendirectedtotheturbinethroughfourmainsteamlines.Eachsteamlineisprovidedwithtwoisolationvalvesinseries,oneoneachsideoftheprimarycontainmentbarrier.1.2.2.3.3ReactorRecirculationSstemTheReactorRecirculationSystempumpsreactorcoolantthroughthecoretoremovetheenergygeneratedinthefuel.Thisisaccomplishedbytworecirculationloopsexternaltothereactorvesselbutinsidetheprimarycontainment.Eachloophasonemotor-drivenrecirculationpump.Recirculationpumpspeedcanbevariedtoallowsomecontrolofreactorpowerlevelthroughtheeffectsofcoolantflowrateonmoderatorvoidcontent.1.2.2.3.4ResidualHeatRemovalSstemTheResidualHeatRemovalSystem(RHRS)consistsofpumps,heatexchangersandpipingthatfulfillthefollowingfunctions:a~b.Removalofdecayheatduringandafterplantshutdown.Rapidinjectionofwaterintothereactorvesselfollowingalossofcoolantaccident,ataratesufficienttorefloodthecoremaintainfuelcladdingbelowthelimitscontainedin10CFR50.46.ThisisdiscussedinSubsection1.2.2.4.Rev.47,06/941.2-14 SSES-FSARc~Removalofheatfromtheprimarycontainmentfollowingaloss-of-coolantaccident(LOCA)tolimittheincreaseinprimarycontainmentpressure.Thisisaccomplishedbycoolingandrecirculatingthewaterinsidetheprimarycontainment.TheredundancyoftheequipmentprovidedforthecontainmentisfurtherextendedbyaseparatepartoftheRHRSwhichsprayscoolingwaterintothedrywell.,ThislattercapabilityisdiscussedinSubsection1.2.2.4.12.d.Provideforcoolingofthespentfuelpool(s)followingaseismiceventwhichresultsinalossofnormalspentfuelpoolcooling,inconjunctionwithnormalshutdownofbothunits.1.2.2.3.5ReactorWaterCleanuSstemRWCUAReactorWaterCleanupSystem,whichincludesafilterdemineralizer,isprovidedtocleanupthereactorcoolingwater,toreducetheamountsofactivatedcorrosionproductsinthewater,andtoremovereactorcoolantfromthenuclearsystemundercontrolledconditions.1.2.2.4SafetRelatedSstemsSafetyrelatedsystemsprovideactionsnecessarytoassuresafeshutdown,toprotecttheintegrityofradioactivematerialbarriers,and/ortopreventthereleaseofradioactivematerialinexcessallowabledoselimits.Thesesystemsmaybecomponents,groupsofcomponents,systems,orgroupsofsystems.EngineeredSafetyFeature(ESF)systemsareincludedinthiscategory.ESFsystemshaveasolefunctionofmitigatingtheconsequencesofdesignbasisaccidents.1.2.2.4.1ReactorProtectionSstemTheReactorProtectionSysteminitiatesarapid,automaticshutdown(scram)ofthereactor.Thisactionistakenintimetopreventexcessivefuelcladdingtemperaturesandanynuclearsystemprocessbarrierdamagefollowingabnormaloperationaltransients.TheReactorProtectionSystemoverridesalloperatoractionsandprocesscontrols.Rev.46,06/931.2-15 SSES-FSAR1.2.2.4.2Neutron-MonitorinSstemNotalloftheNeutronMonitoringSystemqualifiesasanuclearsafetysystem;onlythoseportionsthatprovidehighneutronfluxsignalstotheReactorProtectionSystemaresafetyrelated.Theintermediaterangemonitors(XRM)andaveragepowerrangemonitors(APRM),whichmonitorneutronfluxviain-coredetectors,signaltheReactorProtectionSystemtoscramintimetopreventexcessivefuelcladtemperaturesasaresultofabnormaloperationaltransients.Rev.46,06/931.2-(16)

SSES-FSAR3.1.2.1.5SharingofStructures,Systems,andComponentsCriterion5CriterionStructures,systems,andcomponentsimportanttosafetyshallnotbesharedamongnuclearpowerunitsunlessitcanbeshownthatsuchsharingwillnotsignificantlyimpairtheirabilitytoperformtheirsafetyfunctions,including,intheeventofanaccidentinoneunit,anorderlyshutdownandcooldownoftheremainingunits.DesinConformanceAlthoughSusquehannaSESUnits1and2sharecertainstructures,systems,andcomponents,sharingthemdoesnotsignificantlyimpairperformanceoftheirsafetyfunctions.Thefollowingsafetyrelatedstructuresaresharedbetweenbothunits:ControlStructureDieselGeneratorBuildingsESSWPumphouseSprayPondSpentFuelPoolsThesafetyrelatedstructuresaredesignedtoremainfunctionalduringand,followingthemostseverenaturalphenomena.Thereforesharingthesestructureswillnotimpairtheirabilitytoperformtheirsafetyfunctions.SeismicCategoryI'tructureswhichhousesafetyrelatedsystemsandequipmentarediscussedinSection3.8.Thesharedsystemswhichareimportant.tosafetyarediscussedbelow;amoredetaileddiscussion-maybefoundinthereferencedSubsections:a)b)c)d)e)f)EmergencyServiceWaterSystemDieselGeneratorsUltimateHeatSink'(SprayPond)OffsitePowerSuppliesUnit1ACDistributionSystemResidualHeatRemoval(FuelPoolCoolingMode)(ESWS)9.2.58.3.1.49.2.5SE9.2.68.28.3.15.4.7.1.1'Rev.47,06/943.1-6

,~1SSES-FSAREmerencServiceWaterSstemESWSTheESWSisdesignedtoa)SupplycoolingwatertotheRHRpumpsandtheirassociatedroomcoolersduringtheseveralnon-emergencymodesofRHRpumpoperationsuchasnormalshutdown,andhotstandby.b)Supplycoolingwatertothevariousdieselgeneratorheatexchangers,RHRpumps,roomcoolers,RBCCWandTBCCWheatexchangersduringemergencyshutdownconditionssuchasaLOCA.c)SupplycoolingwatertotheRHRpumpsandtheirassociatedroomcoolersduringaseismiceventthatresultsinalossofthenon-seismicCategoryIFuelPoolCoolingSystem.Duringthisevent,ESWSwouldalsosupplywatertothespentfuelpoolstomake-upforevaporativelossesandfillthespentfuelpoolstotheproperlevelneededtosupporttheRHRFPCmodeshouldthenormalmake-upsourcebeunavailable.TheESWSpumpsarelocatedintheESWSpumphousewiththeRHRSWpumps.TheESWSpumphouseisdesignedasSeismicCategoryIandtheESWSconsistsoftworedundantloops(denotedAandB)eachcapableofproviding100percentofthecoolingwaterrequiredbyalltheESFequipmentofbothUnits1and2simultaneously.Thesystemisdesignedsothatnosingleactiveorpassivecomponentfailurewillpreventitfromachievingitssafetyrelatedobjective.Thesystemstartsautomaticallyonadieselstartsignal.Foradditionaldiscussion,seeSubsection9.2.5.DieselGeneratorsDieselGeneratorsA,B,CandDarehousedinaSeismicCategoryIstructure.Theyareseparatedfromeachotherbyconcretewallswhichprovidemissileprotection.Additionally,asparedieselgenerator(DieselGenerator'E')isprovidedwhichcanbemanuallyrealignedasareplacementforanyoneoftheotherfourdieselgenerators.Thus,anyoneoftheotherdieselgenerators(A,B,CorD)canberemovedfromserviceforextendedmaintenanceandtheDieselGenerator'E'anbesubstitutedsothattherearefouroperabledieselgenerators.DieselGenerator'E'shousedinitsownSeismicCategoryIstructurewhichalsoprovidesmissileprotection.Lossofoneofthefouraligneddieselgeneratorswillnotimpairthecapabilitytosafelyshutdownbothunits,sincethiscanbeRev.47,06/943017 SSES-FSARdonewiththreedieselgenerators.Foradditionaldiscussion,seeSubsection8.3.1.4.FordescriptionsoftheDieselGeneratorFuelOilSystem,CoolingWaterSystem,AirStartingSystem,LubeOilSystem,andtheIntakeandExhaustSystemsseeSubsections9.5.4,9.5.5,9'.6,9.5.7,and9.5.8respectively.FormissileprotectionseeSubsection3.5.SeparationisdiscussedinSections3.12and8.3.UltimateHeatSinkSraPondThespraypondprovidesthewaterforboththeESWSsystemandtheRHRSWsystems.ItistheultimateheatsinkforbothUnits1and2.ThereturnlinesfromtheESWSandtheRHRSWarecombinedandthetotalquantityofwaterfromboththesesystemsisdischargedthroughspraynetworks,whichdissipatetheheatbacktothepond.Therearetworedundantreturnloops(AandB);eitheroneiscapableofhandlingthefullflowfromtheESWSandRHRSWwhenshuttingdowntwounitssimultaneously.Eachreturnloopsuppliesaseparatespraynetworkandeach,ofthesenetworksisdividedintoalargeonecapableofdissipatingtheheatfromtheESWSandtheRHRSWfromtheRHRheatexchangerononeunit,andasmalleronecapableofdissipatingtheheatfromtheRHRheatexchangeronthesecondunit.Thespraypondcontainssufficientwatertomeettherequirementsforshuttingdownoneunitintheeventofanaccidentandtopermitthesafeshutdownofthesecondunitforaperiodofthirtydayswithoutmakeup.ForadditionaldiscussionseeSubsections9.2.5and9.2.6.OffsitePowerSuliesThetwopreferredoffsitepowersuppliesaresharedbybothunits.Thecapacityofeachoffsitepowersupplyissufficienttooperatetheengineeredsafetyfeaturesofoneunitandsafeshutdownloadsoftheotherunit.Foradditionaldiscussion,seeSection8.2.Unit1ACDistributionSstemTheUnit1ACDistributionSystemisasharedsystembetweenbothunits,sincethecommonequipment(EmergencyServiceWater,StandbyGasTreatmentSystem,ControlStructureHVAC,etc.)isenergizedonlyfromtheUnit1ACDistributionSystem.Rev.47,06/943.1-8 SSES-FSARTherearenoUnit2specificloadsenergizedfromtheUnit1ACDistributionSystem.ThecapacityoftheUnit1ACDistributionSystemissufficienttooperatetheengineeredsafetyfeaturesononeunitandthesafeshutdownloadsoftheotherunit.ResidualHeatRemovalFuelPoolCoolinMode)WiththeSpentFuelPoolscrosstied,oneunit'sRHRsystemcanbeusedtocoolstoredspentfuelinbothspentfuelpools.Inthecrosstiedconfiguration,theRHRFPCmodeofoneunitwilldrawsuctionfromthatunit'sskimmersurgetankandreturnthecooledflowtothebottomoftheunit'sfuelpool.Nodirectflowtoorfromtheoppositeunit'sfuelpoolwillbeaccomplished.WiththepoolscrosstiedandRHRFPCinoperationononeoftheunitsadequatecoolingofbothpoolswillbeachieved.ForfurtherdiscussionsseeSubsections5.4.7.1.1.6,5.7.2.1,c,9.1.3.1c,and9.1.3.3.3.1.2.2ProtectionbyMultipleFissionProductBarriersQrouII3.1.2.2.1ReactorDesinCriterion10CriterionThereactorcoreandassociatedcoolant,control,andprotectionsystemsshallbedesignedwithappropriatemargintoassurethatspecifiedacceptablefueldesignlimitsarenotRev.47,06/94 SSES-FSAR3)In-serviceInspection4)ReactorVesselandAppurtenances5)ReactorRecirculationSystem5.25.45.43.1.2.4.4ReactorCoolantMakeupCriterion33CriterionAsystemtosupplyreactorcoolantmakeupforprotectionagainstsmallbreaksinthereactorcoolantpressureboundaryshallbeprovided.Thesystemsafetyfunctionshallbetoassurethatspecifiedacceptablefueldesignlimitsarenotexceededasaresultofreactorcoolantlossduetoleakagefromthereactorcoolantpressureboundaryandruptureofsmallpipingorothersmallcomponentswhicharepartoftheboundary.Thesystemshallbedesignedtoassurethatforonsiteelectricpowersystemoperation(assumingoffsitepowerisnotavailable)andforoffsiteelectricpowersystemoperation(assumingonsitepowerisnotavailable)thesystemsafetyfunctioncanbeaccomplishedusingthepiping,pumps,,andvalvesusedtomaintaincoolantinventoryduringnormalreactoroperation.DesinConformanceTheplantisdesignedtoprovideamplereactorcoolantmakeupforprotectionagainstsmallleaksintheRCPBforanticipatedoperationaloccurrencesandpostulatedaccidentconditions.ThedesignofthesesystemsmeetstherequirementsofCriterion33.Forfurtherdiscussion,seethefollowingsections:2)3)4)5)6)ReactorCoolantPressureBoundaryLeakageDetectionSystems5.2ReactorCoreIsolationCoolingSystem5.4EmergencyCoreCoolingSystem6.3ReactorVessel-InstrumentationandControl7.6MakeupDemineralizerSystem9.2CondensateStorageandTransferSystem9'3.1.2.4.5ResidualHeatRemovalCriterion34CriterionAsystemtoremoveresidualheatshallbeprovided.Thesystemsafetyfunctionshallbetotransferfissionproductdecayheatandotherresidualheatfromthereactorcoreataratesuchthatspecifiedacceptablefueldesignlimitsandthedesignconditionsofthereactorcoolantpressureboundaryarenotexceeded.Rev.46,06/933.1-39 SSES-FSARSuitableredundancyincomponentsandfeatures,andsuitableinterconnections,leakdetection,andisolationcapabilitiesshallbeprovidedtoassurethatforonsiteelectricpowersystemoperation(assumingoffsitepowerisnotavailable)andforoffsiteelectricpowersystemoperation(assumingonsitepowerisnotavailable)thesystemsafetyfunctioncanbeaccomplished,assumingasinglefailure.DesinConformanceRHRsystemprovidesthemeanstoremovedecayheatandresidualheatfromthenuclearsystemsothatrefuelingandnuclearsystemservicingcanbeperformed.MajorRHRsystemequipmentconsistsoftwoheatfourmainsystempumps.Theequipmentisassociatedvalvesandpiping,andtheinstrumentationareprovidedforpropersystemexchangersandconnectedbycontrolsandoperation.Twoindependentloopsarelocatedinseparateprotectedareas.TheRHRsystemisdesignedforfourmodesofoperation:a)Shutdowncoolingb)Suppressionpoolcooling(alsocontainmentspray)c)Lowpressurecoolantinjection.d)FuelPoolCoolingBothnormalacpowerandtheauxiliaryonsitepowersystemprovideadequatepowertooperatealltheauxiliaryloadsnecessaryfor,plantoperation.Thepowersourcesfortheplantauxiliarypowersystemaresufficientinnumber,andofsuchelectricalandphysicalindependencethatnosingleprobableeventcouldinterruptallauxiliarypoweratonetime.Theplantauxiliarybusessupplyingpowertoengineeredsafetyfeaturesandreactorprotectionsystemsandauxiliariesrequiredforsafeshutdownareconnectedbyappropriateswitchingtothefouralignedstandbydiesel-drivengeneratorslocatedintheplant.Eachpowersource,uptothepointofitsconnectiontotheauxiliarypowerbuses,iscapableofcompleteandrapidisolationfromanyothersource.Loadsimportanttoplantoperationandsafetyaresplitanddiversifiedbetweenswitchgearsections,andmeansareprovidedfordetectionandisolationofsystemfaults.Theplantlayoutisdesignedtoeffectphysicalseparationofessentialbussections,standbygenerators,switchgear,interconnections,feeders,powercenters,motorcontrolRev.46,06/933.1-40 SSES-FSARcenters,andothersystemcomponents.Fourstandbydieselgenerators(A,B,C,andD)andasparedieselgenerator(E),whichcanbemanuallyrealignedasareplacementforanyoneoftheotherfourdieselgeneratorsareprovided.Thesedieselgeneratorssupplyasourceofelectricalpowerwhichisself-containedwithintheplantandisnotdependentonexternalsourcesofsupply.Thestandbygeneratorsproduceacpoweratavoltageandfrequencycompatiblewiththenormalbusrequirementsforessentialequipmentwithintheplant.Thestandbydieselgeneratorsystemishighlyreliable.Anythreeofthefivegeneratorsareadequatetostartandcarrytheessentialloadsrequiredforasafeandorderlyshutdown.TheRHRsystemisadequatetoremoveresidualheatfromthereactorcoretoensurefuelandRCPBdesignlimitsarenotexceeded.RedundantreactorcoolantcirculationpathsareavailabletoandfromthevesselandRHRsystem.UseofRHRintheFuelPoolCoolingmodewillnotadverselyimpacttheabilityofRHRtoperformReactorCoreCoolingfunctionsasdiscussedinSubsections5.4.7.1.1.6,5.4.7.2.6c,9.1.3.1c,and9.1.3.3.Redundantonsiteelectricpowersystemsareprovided.ThedesignoftheRHRsystem,includingitspowersupply,meetstherequirementsofCriterion34.Forfurtherdiscussion,seethefollowingsections:1)2)3)4)5)6)7)ResidualHeatRemovalSystemEmergencyCoreCoolingSystemsEmergencyCoreCoolingSystemsInstrumentationandControlAuxiliaryPowerSystemStandbyacPowerSupplyandDistributionStationServiceWaterAccidentAnalysis5.46.37'8.38.39.215.03.1.2.4.6EmergencyCoreCoolingCriterion35CriterionAsystemtoprovideabundantemergencycorecoolingshallbeprovided.Thesystemsafetyfunctionshallbetotransferheatfromthereactorcorefollowinganylossofreactorcoolantataratesuchthat(1)fuelandcladdamagethatcouldinterferewithcontinuedeffectivecorecoolingispreventedand(2)cladmetal-waterreactionislimitedtonegligibleamounts.Rev.46,06/933.1-41 SSES-FSARSuitableredundancyincomponentsandfeatures,andsuitableinterconnections,leakdetection,isolation,andcontainmentcapabilitiesshallbeprovidedtoassurethatforonsiteelectricpowersystemoperation(assumingoffsitepowerisnotavailable)andforoffsiteelectricpowersystemoperation(assumingonsitepowerisnotavailable)thesystemsafetyfunctioncanbeaccomplished,assumingasinglefailure.Rev.46,06/933.X-(42)

SSES-FSARDesinConformanceTheemergencysafeguardservicewatersystem,whichcomprisesboththeEmergencyServiceWatersystemandtheResidualHeatRemovalServiceWatersystem,providescoolingwaterfortheremovalofexcessheatfromallstructures,systems,andcomponentswhicharenecessarytomaintainsafetyduringallabnormalandaccidentconditions.Theseincludethestandbydieselgenerators,theRHRpumpoilcoolersandsealwatercoolers,thecorespraypumproomunitcoolers,RCICpumproomunitcoolers,theHPCIpumproomunitcoolers,theRHRheatexchangers,RHRpumproomunitcoolers,emergencyswitchgearandloadcenterroomcoolersandthecontrolstructurechiller.ItalsoprovideswatertotheRHRpumpsandabovementionedroomunitcoolersduringaseismiceventtosupportoperationoftheRHRFuelPoolCooling(RHRFPC)mode.Make-upwatertotheSpentFuelPool(SFP)isprovidedduringaseismiceventinordertomake-upforevaporativelossesandfillingoftheSFPinsupportofRHRFPC.RHRSWprovidesthecoolingwatertotheRHRheatexchangersfortheRHRFPCmode.TheengineeredsafeguardservicewatersystemisdesignedtoSeismicCategoryIrequirements.Redundantsafetyrelatedcomponentsservedbytheengineeredsafeguardservicewatersystemaresuppliedthroughredundantsupplyheadersandreturnedthroughredundantdischargeorreturnlines.Electricpowerforoperationofredundantsafetyrelatedcomponentsofthissystemissuppliedfromseparateindependentoffsiteandredundantonsitestandbypowersources.Nosinglefailurerendersthesesystemsincapableofperformingtheirsafetyfunctions.ReferencedSubsectionsareasfollows:1)2)3)4)5)acPowerSystemsServiceWaterSystemEngineeredServiceWaterSystemRHRServiceWaterSystemUltimateHeatSink8.3.19.2.19.2.59.2.69.2.73.1.2.4.16InspectionofCoolingWaterSystemCriterion45CriterionThecoolingwatersystemshallbedesignedtopermitappropriateperiodicinspectionofimportantcomponents,suchasheatexchangersandpiping,toassuretheintegrityandcapabilityofthesystem.Rev.46,06/933.1-51 SSES-FSARDesinConformanceTheengineeredsafeguardservicewaterandtheRBCCWsystemsaredesignedtopermitappropriateperiodicinspectioninordertoensuretheintegrityofsystemcomponents.Rev.46,06/933.1-(52)

SSES-FSARDesinConformanceNewFuelStoraeNewfuelisplacedindrystorageinthenewfuelstoragevaultthatislocatedinsidethereactorbuilding.Thestoragevaultwithinthereactorbuildingprovides*adequateshieldingforradiationprotection.Storageracksprecludeaccidentalcriticality(seeSubsection3.1.2.6.3).Thenewfuelstorageracksdonotrequireanyspecialinspectionandtestingfornuclearsafetypurposes.However,theracksareaccessibleforperiodicinspection.SentFuelHandlinandStoraeIrradiatedfuelisstoredsubmergedinthespentfuelstoragepoollocatedinthereactorbuilding.Fuelpoolwateriscirculatedthroughthefuelpoolcoolingandcleanupsystemtomaintainfuelpoolwatertemperature,purity,waterclarity,andwaterlevel.Storageracksprecludeaccidentalcriticality(seeSubsection3.1.2.6.3).Reliabledecayheatremovalisprovidedbythefuelpoolcoolingandcleanupsystem.Thepoolwateriscirculatedthroughthesystemwithsuctiontakenfromthepoolandisdischargedthroughdiffusersatthebottomofthefuelpool.Poolwatertemperatureismaintainedbelow125'Fwhenremovingthemaximumnormalheatload(MNHL)fromthepoolwiththeservicewatertemperatureatitsmaximumdesignvalue.TheRHRsystemwithitssubstantiallylargerheatremoval"capacitycanbeusedasabackupforfuelpoolcoolingwhenheatloadslargerthanthecapabilityofthefuelpoolcoolingsystemsareinthespentfuelpools.RHRalsoprovidesreliabledecayheatremovaltothespentfuelpoolsifthenormalfuelpoolcoolingsystemislostduetoaSeismicevent.OperationoftheRHRFuelPoolCooling(RHRFPC)modewillprovideseismicCategoryI,Class1Ecoolingtothespentfuelpoolssothatboilingofthespentfuelpoolsdoesnotoccurasaresultofaseismicevent.ESWprovidesSeismicCategoryI,Class1Emake-upinsupportofRHRFPC.Highandlowlevelswitchesindicatepoolwaterlevelchangesinthemaincontrolroom.Fissionproductconcentrationinthepoolwaterisminimizedbyuseofthefiltersanddemineralizer.Thisminimizesthereleasefromthepooltothereactorbuilding.Rev.46,06/933.1-60 SSES-FSARThereactorbuildingventilationsystemandthesecondarycontainmentaredesignedtolimitthereleaseofradioactivematerialstotheenvironsandensurethatoffsitedosesarelessthanthelimitingvaluesspecifiedin10CFR100duringoperationandallaccidentconditions.Nospecialtestsarerequired,becauseatleastonepumpandheatexchangerarecontinuouslyinoperationwhilefuelisstoredinthepool.Duplicateunitsareoperatedperiodicallytohandlehighheatloadsortoreplaceaunitforservicing.Routinevisualinspectionofthesystemcomponents,instrumentation,andtroublealarmsareadequatetoverifysystemoperability.TestingoftheRHRFPCmodeisaccomplishedthroughroutinetestingofthepumpsandheatexchangersinsupportofothermodesofRHR.ThevalvessupportingtheRHRFPCmodeareroutinelystrokedtoconfirmproperoperationofthevalvesfortheirRHRFPCmission.Rev.46,06/933.1-(61)

SSES-FSARfuel.Theseinterlocksprecludeanyloadsuspendedfromthiscranefromtippingoveronthestoredfuelintheeventofacranefailure.The5tonauxiliaryhooksuspendedfromthesamecranetrolleyispreventedfrompassingoverstoredfuelwhenfuelhandlingisnotinprogressbyadministrativecontrols'herearenoplannedtransfe'rsofloadsheavierthananewfuelelementoverthestoredfuel.(3)

Reference:

PositionC.8.ASeismicCategoryImakeupwatersupplyfromeachemergencyservicewaterloopispermanentlyconnectedto,eachspentfuelpoolbytwoindependentSeismicCategoryIpipingroutes.Themake-upisprovidedforfillingthe-spentfuelpooltotheproperleveltosupportoperationoftheRHRfuelpoolcoolingmode,andtoprovideformake-upfromevaporativelossesduringcoolingbyRHR.Themake-uprateissizedbasedonboilingsoastobeconservative.ThenormalmakeupsystemtothefuelpoolisnotSeismicCategoryI.ReulatoGuide1.14REACTORCOOLANTPUMPFLY-WHEELINTEGRITYRevision1Auust1975Notapplicable.ReulatorGuide1.15-TESTINGOFREINFORCINGBARSFORCATEGORYICONCRETESTRUCTURESRevision1December281972TestingofreinforcingbarsforCategoryIconcretestructuresisincompliancewiththisregulatoryguide.ReulatorGuide1.16-REPORTINGOFOPERATINGINFORMATION-APPENDIXATECHNICALSPECIFICATIONSRevision4Auust1975InlieuofthepositionsstatedinthisRegulatoryGuide,thereportingofoperatinginformationfortheSusquehannaSEScomplieswithTechnicalSpecificationsand10CFR50.73.ReulatorGuide1.17PROTECTIONOFNUCLEARPOWERPLANTSAGAINSTINDUSTRIALSABOTAGEJune1973Inlieuofthepositionsstatedinthisregulatoryguide,theprotectionofSusquehannaSESagainstindustrialsabotagecomplieswith10CFR73.Rev.46,06/933.13-6 SSES-FSAR

Reference:

PositionC.l.dandC.l.g.Thenormalspentfuelpoolcoolingsystemisnon-seismicCategoryI.IfaseismiceventwouldoccurcoolingofthespentfuelisachievedbyuseoftheRHRFuelPoolCooling(RHRFPC)modeasdescribedinsections5.4.7.1.1',5.4.7.2.6c,9.1.3.1,and9.1.3.3.EitherorbothoftwoSeismicCategoryIESWmakeupwatersuppliestoeachpoolcanprovidemake-upinsupportoftheRHRFPCmode.Additionally,ESWiscapableofsupplyingmake-upfortheboilingspentfuelpoolanalysisasdescribedinAppendix9A.

Reference:

PositionC.l.e.TheMainSteamSystem(MSS)beyondtheouterisolationvalvesuptoandincludingtheturbinestopvalvesandallbranchlines21/2in.indiameterandlarger,uptoandincludingthefirstvalve(includingtheirrestraints)arenotclassifiedSeismicCategoryI;becauseportionsofthepipeareroutedinanon-SeismicCategoryIbuilding(theTurbineBuilding).However,theturbinebuildinghasbeendesignedtowithstandanSSEasstatedinSubsection3.7b.2'.FurtherdescriptionoftheturbinebuildingisgiveninSubsection3.8.4.1;applicableloadcombinationsaregiveninTable3.8-10.ThesubjectpipingisdesignedinaccordancewithASMESectionIII,Class2requirementsfortheOBEandSSEasdescribedinSubsection10.3.3.

Reference:

PositionC.l.h.ThecomponentcoolingwaterportionsofthereactorrecirculationpumpsarenotSeismicClassIsincetheydonotinvolveasafetyfunction.

Reference:

ParagraphC.2oftheRegulatoryGuide.Itemswhichwouldotherwisebeclassifiednon-seismiccategoryI,"butwhosefailurecouldreducethefunctioning"ofitemsimportanttosafety"toanunacceptablesafetylevel"aretobe"designedandconstructedsothattheSSEwouldnotcausesuchfailure."Inaddition,ParagraphC.4oftheguiderequiresthatthe"pertinentqualityassurancerequirementofAppendixBto10CFRPart50shouldbeappliedtothesafetyrequirements"ofsuchitems.Bothof'hesepositionsareconsideredtobeadequatelymetbyapplyingthefollowingpracticestosuchitems:06/933.13-10 SSES-FSAR(a)Designanddesigncontrolforsuchitemsarecarriedoutinthesamemannerasthatforitemsdirectlyimportanttosafety.Thisincludestheperformanceofappropriatedesignreviews.Rev.46,06/933.13-(11)

SSES-FSARTABLE3.2-1Continued)Page9.PrincipalComponents(34*)FSARSectionSourceof~Su1(1)*Loca-tion(2)*QualityGroupClassi-fication(3)*SafetyClass(4)*PrincipalConstruc-tionCodesandStandards(5)*SeismicCategonr(6)*QualityAssuranceReenirementCmmmnte(7)**UnderReactorVesselServiceEuintEquipmenthandlingplatformCRDhandlingequipmentFuelPoolCooli5CleanuSstemHeatexchangersPumpsSkimaersurgetanksFilterdemineralizervesselsResinandprecoattanksCoolinglooppipingandvalvesdownstreamofvalve1-53-001.2-53-001RHRintertiepipingandvalvesEmergencyservicewatermakeuppipingandvalvesOtherpipingandvalvesCoolinlooipinustreamofvalvel-53-Ii0(.2-5-II01fromskirmersurgetankRadioactiveWasteManaementLiuidWasteNanaementSstemsCentrifugalpumpsAtmosphericTanks9.1.49.1.311.2GEGER/RW/T0RW/T0OtherXOtherXOtherIII-3.TB1ACOtherIII-3,OtherIII-3OtherVIII-1OtherAPI-650OtherIII-3OtherII1-3OtherIII-3OtherB31.1.0OtherIII-3OtherIII-3OtherVIII-1/III-3INA19.3146,5519.31.56I31.2231.22Rev.47,06/94*RefertotheGeneralNotesattheendofthistable.

SSES-FSARTABLE3.2-1SSESDESIGNCRITERIASUMMARY(Continued)Page5254)Thedieselgeneratorjacketwatercoolers(OE507BandOE507D)utilizeanASMESectionVIIIreplacementtubebundleinaccordancewiththeguidanceofNRCGenericLetter89-09.55)ThefollowingmanuallyoperatedvalvesprovideafillablevolumeforuseoftheRHRFPCmode.Thefollowingmanuallyoperatedvalves,whichareintheseismicallyanalyzedsectionsofpipe,requireacapabilitytobeclosedfollowingaseismicevent.Thesevalveshavebeenanalyzedtodemonstratethattheywillbecapableofclosurefollowingaseismicevent:SpentFuelPoolto153018A/B(253018A/B),FuelPoolGateDrainto153038(253038),andReactorWellDiffuserto153030A/B(25303OA/B).Thefollowingmanuallyoperatedvalves,whichareinseismicallyanalyzedsectionsofpipe,haveapostseismiceventfunctiontoremainintheclosedposition:ReactorWellDrainto153031(253031),ReactorWellDrainto153032(253032),ReactorWellDrainto153062(253062),DryerSeparatorPoolDrainto153040(253040),DryerSeparatorPoolDrainto153041(253041),CaskPitGateDrainto153050(253050),CaskPitDrainto153054(253054),CaskPitDrainto053084&,253800,andCaskPitDiffuserto053025.56)TheportionsofpipingbetweenthesurgetankuptoandincludingvalvesHV15308(25308),153076(253076),and153064A/B(253064A/B)'havebeenanalyzedtoshowthattheywillremainintactfollowingaseismicevent.Thesevalveshavebeenanalyzedtodemonstratethattheywillbecapableofclosure(orremainingclosed)followingaseismicevent.ClosureofthesevalvesisnecessarytoprovideafillablevolumeforuseoftheRHRFPCmode.TheSkimmerSurgeTankdrainlinevalves,153065A(253065A),arenormallyclosedandassumedtoremainclosedduringaseismicevent.Rev.47,06/94 SSES-FSARthecapacityofasingleRHRheatexchangerandrelatedservicewatercapability.Figure5.4-12showstheminimumtimerequiredtoreducevesselcoolanttemperatureto212'FusingoneRHRheatexchangerandallowing2hoursforflushing.5.4.7.1.1.2LowPressureCoolantIn'ectionLPCIModeThe,functionaldesignbasesforthe,LPCImodeistopumpatotalof21,300gpmofwaterperloopusingtheseparatepumploopsfromthesuppressionpoolintothecoreregionofthevessel,whenthevesselpressureis20psidoverdrywellpressure.Injectionflowcommencesat280psidvesselpressureabovedrywellpressure.Theinitiatingsignalsare:vessellevel1.0feetabovetheactivecoreordrywellpressuregreaterthanorequalto1.69psigcoincidentwithalowreactorpressure.Thepumpswillattainratedspeedin27secondsandinjectionvalvesfullyopenin40seconds'.4.7.1.1.3SuressionPoolCoolinModeThefunctionaldesignbasisforthesuppressionpoolcoolingmodeisthatitshallhavethecapacitytoensurethatthebulksuppressionpooltemperatureimmediatelyafterablowdownshallnotexceed207'F.5.4.7.1.1.4ContainmentSraCoolinModeThefunctionaldesignbasisforthecontainmentspraycoolingmodeisthatthereshouldbetworedundantmeanstosprayintothedrywellandsuppressionpoolvaporspacetoreduceinternalpressuretobelowdesignlimits.5.4.7.1.1.5ReactorSteamCondensinModeThissectionhasbeenintentionallydeleted.5.4.7.1.1.6FuelPoolCoolinModeThefunctionaldesignbasisforthefuelpoolcoolingmodeisasfollows:a)TheRHRFPCmodeisdesignedandoperatedtoprovidecoolingsuchthatthefuelpoolwillbemaintainedatorbelow125FwhentheEmergencyHeatLoad(EHL)isRev.46,06/935.4-33 SSES-FSARresidentinanisolatedfuelpool.TheEHLcanberemovedwithaRHRSWinlettemperatureof91'FwithonlyoneRHRpumpandheatexchange.Forcrosstiedfuelpools,oneRHRpumpandheatexchangerinoneunitincombinationwiththenormalFuelPoolCoolingsystemfromtheadjacentunitissufficienttomaintainthefuelpoolsatorbelow125'FwiththeEHLresidentinonefuelpoolandfuelatthescheduledoffloadrateintheotherfuelpool.ThisfunctionisdescribedinSections9.1.3.band9.1.3.2.b)TheRHRFPCmodeisdesignedandoperatedtoprovidesufficientcoolingtopreventfuelpoolboilingintheeventthataseismiceventcausesanextendedlossofbothunits'ormalfuelpoolcoolingsystems.Thiscapabilityexistsforbothcrosstiedandisolatedfuelpools.WhenoneRHRpumpisoperatedintheRHRFPCmode,thespentfuelpoollevelmustberaisedtoaminimumlevelabovetheweirsinordertosupportthedesignflowrateforthismode.AdditionaldetailsdescribingthismodeofRHRarecontainedinSections5.4.7.2.6c,9.1.3.1c,9.1.3.2,and9.1.3.3.5.4.7.1.2DesignBasisforIsolationofRHRSystemfromReactorCoolantSstemThelowpressureportions,oftheRHRsystem,areisolatedfromfullreactorpressurewhenevertheprimarysystempressureisabovetheRHRsystemdesignpressure.SeeSubsection5.4.7.1.3forfurtherdetails.Inaddition,automaticisolationmayoccurforreasonsofvesselwaterinventoryretentionwhichisunrelatedtolinepressurerates.(SeeSubsection5.2.5foranexplanationoftheLeakDetectionSystemandtheisolationsignals.)ReactorCoolantpressureboundaryvalvesaresubjecttoinserviceinspectionleakagetestingrequirementsasprovidedin10CFR50.55a(seeSubsection3.9.6).TheRHRpumpsareprotectedagainstdamagefromacloseddischargevalvebymeansofautomaticminimumflowvalves,whichopenonlowmainlineflowandcloseonhighmainlineflow.5.4.7.1.3DesinBasisForPressureReliefCaacitThereliefvalvesintheRHRsystemaresizedononeofthreebases:(1)ThermalreliefonlyRev.46,06/935.4-34 SSES-FSAR(2)Valvebypassleakageonly(3)Controlvalvefailureandthesubsequentuncontrolledflowwhichresults.Transientsaretreatedbyitems(1)and(3);item(2)abovehasresultedfromanexcessiveleakpast'isolationvalves.F055ARBshallbesizedtomaintainupstreampipingat450psigand10percentaccumulationwithF051andF052fullyopenandareactorpressureequaltothelowestNuclearBoilersafety/reliefvalvespringsetpoint.F097shallbesizedtomaintainupstreampressureat180psigand10percentaccumulationwithbothPCVF053A&Bfailedopen.F030A,B,C,andD,F025AandB,F029,F126,andF087shallbesetatthedesignpressurespecifiedintheprocessdatadrawingplus10percentaccumulation.Redundantinterlockspreventopeningvalvestothelowpressuresuctionpipingwhenthereactorpressureisabovetheshutdownrange.Thesesameinterlocksinitiatevalveclosureonincreasingreactorpressure.Inadditionahighpressurecheckvalvewillclosetopreventreverseflowfromthereactorifthepressureshouldincrease.Reliefvalvesinthedischargepipingaresizedtoaccountforleakagepastthecheckvalve.5.4.7.1.4DesignBasisWithRespecttoGeneralDesinCriteria5TheRHRsystemforeachunitdoesnotshareequipmentorstructureswiththeothernuclearunitexceptfortheSpentFuelPoolsasdiscussedinSubsection9.1.3.3.TheyalsosharethecommonEmergencyServiceWaterSystem.SharingofthissystemwithrespecttoGeneralDesignCriteria5isdiscussedinSection3.1.2.1.5.Rev.46,06/935.4-(35)

SSES-FSARperformflushingwillcauseinjectionofnon-reactorgradewaterintothereactorpressurevesselbutwillnotaffectperformanceoftheRHRshutdowncoolingsystem.Attheendofthisnominalflush,thetestablecheckbypassvalvemaybeopenedintheshutdownreturnlineandvesselwateris-permittedtoentertheupperportion'.,ofthechosenlooptoprewarmi'ffluentisdirectedtoradwasteandatemperatureelementisusedtocontroleffluenttemperature.Thetestablecheckbypassvalveisclosedandvesselsuctionvalvesareopenedtoallowprewarmingofthelowerhalfoftheshutdownloopwitheffluentdirectedtoradwasteasbefore.Theradwasteeffluentvalvesareclosed,theheatexchangerbypassvalvesopened(theexchangervalveswereclosedaftertheinitialcoldwaterflush),thenthepumpstartsataregulatedflowthroughreturnvalveF017.Afterwaitingseveralminutestopermitloopinternalstabilitytobeestablishedtheservicewaterpumpisstarted,theservicewatervalvesareopened,theheatexchangerinletandoutletvalvesareopenedandcooldownofthevesselisinprogress.CooldownrateissubsequentlycontrolledviavalvesF017(totalflow)andF048(heatexchangerbypassflow).Alloperationsareperformedfromthecontrolroomexceptforopeningandclosingoflocalflushwatervalves.ThemanualactionsrequiredforthemostlimitingfailurearediscussedinSubsection5.4.7.1.5.b.SteamCondensinC.Thissectionhasbeenintentionallydeleted.FuelPoolCoolinModeOperationofRHRinthefuelpoolcoolingmoderequiresmanualactionstobeperformedbothinthecontrolroomandlocally.Thesystemwillalsoberequiredtobefilledandvented,whichwillrequirethemanipulationofvarioussmallmanualvalves.ThefillingoperationmayalsoincludeoperationoftheESWsystemintheeventthenormalfillsystemsareunavailable.Theseactionsaredescribedinandcontrolledbyplantprocedures.5.4.7.3PerformanceEvaluationThermalperformanceoftheRHRheatexchangersisbasedontheresidualheatgeneratedat20hoursafterrodinsertion,a125'Fvesseloutlet(exchangerinlet)temperature,andtheflowoftwoloopsinoperation.Becauseshutdownisusuallyacontrolledoperation,maximumservicewatertemperaturelessRev.46,06/935.4-39 SSES-FSAR10'Fisusedastheservicewaterinlettemperature.Thesearenominaldesignconditions;iftheservicewatertemperatureishigher,theexchangercapabilitiesarereducedandtheshutdowntimemaybelongerandviceversa.5.4.7.3.1ShutdownWithAllComonentsAvailableNotypicalcurveisincludedheretoshowvesselcooldowntemperaturesversustimeduetotheinfinitevarietyofsuchcurvesthatmaybedueto:(1)cleansteamsystemsthatmayallowthemaincondensertobeusedastheheatsinkwhennuclearRev.46,06/935.4-(40)

SSES-FSARf)Theplateswillbewashedinamildabrasiveanddetergentsolution,thenrinsedincleanwaterand/oracetone.Theplateswillbedriedina175'Fovenfora4hours,followedby4hoursina300'Fovenand4additionalhoursina500'Foven.Theplateweightwillbedetermined,atroomtemperature,followingeachdryingi.'nterval.Dryingmaybediscontinuedwhennofurtherweightlossoccurs.g)Eachplatewillbeweighedanddetermineweightchange.h)Reperformstepge.i)Alldatawillberecorded,includingpHvalues,forfuturecomparison.9.1.3SPENTFUELPOOLCOOLINQANDCLEANUPSYSTEM9.1.3.1DesinBasesTheFuelPoolCoolingandCleanupSystem(FPCCS)isdesignedandoperatedwiththefollowingconsiderations:a)Maintainingthefuelpoolwatertemperaturebelow125'F.TheheatloadwhichservedasthebasisfortheFPCCSdesignisbaseduponfillingthepoolwith2840fuelassembliesfromnormalrefuelingdischargesandtransferredtothefuelpoolwithin160hoursaftershutdown.Tables9.1-2aand9.1-2bshowtheoriginallyassumeddischargescheduleandheatload.Table9.1-2eshowsanupdateddischargeschedule.b)Duringanemergencyheatload(EHL)condition,oneRHRpumpandheatexchangerareavailableforfuelpoolcooling.TheEHLconditionoccurswhenthespentfuelracksofonespentfuelpoolcontain2850fuelassembliesincludingafullcoredischargedtothepoolwithin250hoursaftershutdown(controlrodsinserted).Tables9.1-2cand9.1-2dshowthedischargescheduleandheatloadthatwasassumedforthesystem'sdesignforthisconditionforUnits1and2.Table9.1-2fshowsanupdateddischargeschedule.TheRHRFuelPoolCooling(RHRFPC)Modewillmaintaintheisolatedfuelpoolwatertemperature,(withtheheatloadof3.39x10'TU/hr)atorbelow125'FwithorwithoutassistancefromtheFPCCSundernormalrefuelingconditions.WhenthedecayheatloadofthespentfueldropstothelevelforwhichtheFPCCSisdesigned,theRHRsystemmaybedisengaged.Forcrosstiedspentfuelpools,theRHRFPCmodeinoneunitincombinationwiththenormalFuelPoolCoolingSystemoftheotherunitwillmaintainthecrosstiedfuelRev.48,12/949.1-21 SSES-FSARpoolsatorbelow125'FwiththeEHLinonepoolandfuelatthenormalscheduledoffloadrateintheotherpool.c)Followingaseismicevent,thenormalFuelPoolCoolingsystemispostulatedtobeunavailableduetoitsNon-SeismicCategoryI,Non-Class1Epowerdesign.IfsuchaneventweretooccurtheRHRFuelPoolCooling(RHRFPC)modewouldbeusedtoprovidecoolingtothespentfuelpoolstopreventboiling.AllpipingandcomponentsoftheRHRFPCmodeareSeismicCategory1,QualityGroupBorCconstructedtoASMESectionIIIstandards.TheRHRsystemisClass1Epoweredandbothloopshaveseparatepowersupplies.TheRHRFPCsystemishardpipedandrequiresoperationofseveralmanualvalves.(whichareaccessiblefollowingaseismicevent)toestablishtheflowpath.Inaddition,othermanualandmotoroperatedvalvesmustbeoperatedinordertoassureproperoperationoftheRHRFPCmode.ProperoperationofallactivecomponentsintheRHRFPCmodeisconfirmedonaperiodicbasisinaccordancewithplantprocedures.TheRHRpumpsuctionpathfortheFuelPoolCoolingmodeissharedwiththeShutdownCoolingmodeofRHR.Consequently,ShutdownCoolingandFuelPoolCoolingcannotbeperformedconcurrentlyonagivenunit.However,AlternateShutdownCoolingandFuelPoolCoolingcanbeperformedconcurrentlysincedifferentsuctionsourcesareused.Appendix9AcontainsanevaluationofaboilingspentfuelpoolforaNon-SeismicCategoryIFuelPoolCoolingsystem.Boilingofthespentfuelpool(s)wouldnotoccurduringaseismiceventduetouseoftheRHRFuelPoolCoolingsystemasabackupSeismicCategoryIFuelPoolCoolingsystem.TheRHRFPCmodecanbeplacedintoservicewellinadvanceofthepostulatedtimetoboilof25hours(seeSubsection9.1.3.3).d)Tomaintainthewaterclarityandqualityinthepoolsasfollowstofacilitateunderwaterhandlingoffuelassembliesandtominimizefissionandcorrosionproductbuildupthatposearadiologicalhazardtooperatingpersonnel:ConductivitypHChloride(asCl)3mircromho/cmat25'C5.3-7.5at25'C0.5ppmRev.48,12/949.1-22 SSES-FSARHeavyelements(Fe,Cu,Hg,Ni)0.1ppmTotalinsolubles1ppm9.1.3.2SstemDescritionEachreactorunitisprovidedwithitsownFPCCSasshownonFigures9.1-7and9.1-8.Thesystemcoolsthefuelstoragepoolwaterbytransferringthedecayheatoftheirradiatedfuelthroughheatexchangerstotheservicewatersystem.Waterclarityandqualityinthefuelstoragepools,transfercanals,reactorwells,dryer-separatorpools,andshippingcaskpitaremaintainedbyfilteringanddemineralizing.TheFPCCSconsistsoffuelpoolcooling'umps,heatexchangers,skimmersurgetanks,filterdemineralizers,associatedpiping,valves,andinstrumentation.EuimentDescritionTable9.1-1showsthedesignparametersoftheFPCCSequipment.'heseismicandqualitygroupclassificationsoftheFPCCScomponentsarelistedinSection3.2.Oneskimmersurgetankforeachunitcollectsoverflowwaterfromskimmerdrainopeningswithadjustableweirsatthewatersurfaceelevationofeachpoolandwell.Thecommonshippingcaskpitwateroverflowstobothunits'kimmersurgetanks.Wavesuppressionscuppersalongtheworkingsideofthefuelpoolsalsodraintotheskimmersurgetanks.Theskimmeropeningsinthepoollinersareprotectedwithawiremeshscreentopreventfloatingobjectssuchasthesurfacebreakerviewingaidsfromenteringthesurgetanks.Theadjustableweirplatesaresetaccordingtotherequiredcoolingflow,desiredflowpattern,andwatershieldingneeds.TheskimmersurgetankprovidesasuctionheadforthefuelpoolcoolingpumpsandabuffervolumeduringtransientflowsinthenormallyclosedloopFPCCS.Itprovidessufficientlivecapacityforthreedays'ormalevaporativelossfromthefuelpoolwithoutmakeupfromthecondensatetransfersystem.Aremovableobjectretentionscreeninthetankisaccessiblethroughtheflangedtanktop.Tanklevelindicationandalarmsonacontrolpanelontherefuelingfloorand/orthevicinityofthefuelpoolcoolingpumpsannouncewhentheremotemanualmakeupvalvesmustbeopenedorwaterdrainedfromthesystem.Rev.46,06/939.1-23

)

SSES-FSARThefuelpoolcoolingpumpsarestoppeduponalowtanklevelsignalsThreefuelpoolheatexchangerspipedinparallelarelocatedinthereactorbuildingbelowthesurgetankbottomelevation.Theshellsideissubjectedtothestaticheadoftheskimmersurgetanklevelonly.Thisisaminimumof5psilowerthanthetubesideservicewaterpressure,thusminimizingthepossibilityofradioactivecontaminationoftheservicewatersystem(seeSubsection9.2.1)fromatubeleak.Thenumberofheatexchangersinservicedependsonthedecayheatloadfromirradiatedfuelinthespentfuelpool.Thecommoninletandeachheatexchangeroutlettemperaturearerecordedandhightemperaturealarmedonalocalcontrolpanel.Threefuelpoolcoolingpumpspipedinparallelareplacedinserviceinconjunctionwiththeheatexchangers.Theytakesuctionfromtheheatexchangersanddevelopsufficientheadtoprocessapartialsystemflowthroughthefilterdemineralizersandtransferitcombinedwiththebypassflowtothediffuserpipesatthebottomofthepools.Thepumpcontrols,dischargepressureindicators,flowindicator,andalarmsforlowflowandlowdischargepressureareprovidedonalocalcontrolpanel.ThepumpstripindividuallyuponlowNPSH.Threefuelpoolfilterdemineralizersarepipedinparallel.OnefuelpoolfilterdemineralizerisnormallyassociatedwitheachFPCCSwiththethirdoneinstandby.Thedesignflowperfilterdemineralizerislessthanthetotalsystemflow.Partofthecooledwateristhereforebypassingatamanuallyadjustablerate.Rev.46,06/939.X-(24)

SSES-FSARskimmersurgetanks'uringperiodswhentheheatinthepoolisgreaterthanthecapacityofthefuelpoolcoolingsystem(suchthatacceptablefuelpooltemperaturescannotbemaintained),eg,storingofafullcoreofirradiatedfuelshortlyaftershutdown,theRHRsystemcanbeusedtodissipatethedecayheat.OneRHRpumptakessuctionfromanintertielinetotheskimmersurgetankanddischargesthroughoneRHRheatexchangertotwoindependentdiffusersatthefuelpoolbottom.Withthespentfuelpool(s)filledtoaheightapproximately7.5inchesabovetheweirs,theskimmersurgetankprovidessufficientsuctionheadtoanRHRpumpintheRHRFuelPoolCooling(RHRFPC)mode.Makeupwatertoreplenishevaporativeandsmallleakagelossesfromthepoolsisprovidedfromthecondensatetransferstoragetankintotheskimmersurgetankbyopeningaremotemanualvalve.ASeismicCategoryIlinefromeachofthetwoemergencyservicewaterloopsisconnectedtotheRHRintertiediffuserlinesofeachfuelpool,allowingforemergencymakeupinsupportofRHRFPCorduringpostulatedboilingofthepoolwaterasdescribedinAppendix9A.Themanualsupplyvalvesintheseemergencymakeuplinesareaccessiblefromelevationsbelowtherefuelingfloor.9.1.3.3SafetEvaluationAtFPCCSdesignconditionswherethepoolheatloadis12.6MBTU/HRandservicewatertemperatureis95'FtheFPCCSwillmaintainthefuelpoolwaterlessthan125'F.Atimprovedservicewatertemperatureconditions,theFPCCScanmaintainthefuelpoolwaterlessthan125'Fwithlargerheatloadsinthepool.Thisconditionoccursduringrefuelingoutages.WhenthisconditionexiststhepoolismonitoredtoassureadequateFPCCScapacityexists.WhentheFPCCScannotmaintainthepooltemperaturelessthan125'F,theRHRsystemintheFuelPoolCoolingMode(RHRFPC)canbeconnectedtothepoolstomaintainpooltemperaturesbelow125'FbytheRHRFPCmode.ATEHLconditions(33.9MBTU/HR),RHRFPCcanmaintainthepooltemperaturebelow125'FwithspraypondwatertemperaturesbelowTechnicalSpecificationlimits.Poolconfigurationwillbemaintainedduringtheoutagesequencesothatthecalculatedtimetoboilisgreaterthan25hours.ASeismicCategoryImakeupisprovidedbya2in.linefromeachemergencyservicewater(ESW)looptotheRHRfuelpooldiffusers,thusprovidingredundantflowpathsfromareliableRev.46,06/939.1-27 SSES-FSARsourceofwater.ThedesignmakeupratefromeachESWloopisbasedonreplenishingthepostulatedboil-offfromtheMNHLineachfuelpoolfor30daysfollowingthelossoftheFPCCScapacity.ThisprovidesacapacityfarinexcessofwhatwouldberequiredbytheRHRFPCmodeinresponsetoalossofnormalfuelpoolcoolingduetoaseismicevent.AllpipingandequipmentsharedwithorconnectingtotheRHRintertieloopareSeismicCategoryI,QualityGroupC,orequivalent,andcanbeisolatedfromanypipingassociatedwiththenon-SeismicCategoryIQualityGroupCfuelpoolcoolingsystem.DuetoitsNon-SeismicCategoryI,Non-ClasslEpowerdesign,theconsequencesofaseismiceventarerequiredtobeanalyzedfortheFPCsystem.Inresponsetothisevent,theRHRFPCmodewillbeusedtopreventboilingfromoccurring;however,anon-mechanisticevaluationofboilingofbothspentfuelpoolsiscontainedinAppendix9Ainordertoconservativelyboundtheradiologicalconsequences.Thespentfuelpoolsarenormallymaintainedinacrosstiedconfigurationduringdualunitoperationandrefuelingoutages.Thisassuresthatthetimetoboilfollowingalossofnormalfuelpoolcoolingisaminimumof25hours;however,inthisconfigurationthetimetoboilistypicallymuchgreaterthantheminimum25hours.The25hourtimetoboilminimumwouldonlybeapproachedshortlyafteraunitisshutdownforrefueling.Aftercompletionofarefuelingoutage,whenbothunitsareatpower,thetimetoboilistypicallyontheorderof50hours.Thecrosstiedconfigurationallowsuseofeitherunit'ssystems(normalSFPCoolingorRHRFPC)tocoolthepools,thusprovidingfuelpoolcoolingredundancy.Crosstiedspentfuelpoolsalsoprovideredundancyforthelevelinstrumentationinthecontrolroom.ThisinstrumentationisdesignedtooperatefollowinganOperatingBasisEarthquakeandunderboilingspentfuelpoolconditionsandisexpectedtoremainfunctional.WhilenotclassifiedasClass1Eequipment,theinstrumentsreceivepowerfromindependentClass1EpowersuppliesthatareDieselGeneratorbacked.Shouldaseismiceventoccurduringdualunitpoweroperationwithcrosstiedpools,adequatereactorcorecoolingwillbeprovidedandspentfuelpoolboilingwillbeprevented.OnlyoneloopofRHRisnecessarytoprovidelongtermdecayheatremovalperreactorvessel.Similarly,onlyoneloopofRHRisnecessarytoprovidelongtermdecayheatremovaltocrosstiedspentfuelpools.Sinceeitherunit'sRHRsystemcanprovidecoolingtobothunitsspentfuelpoolswiththepoolscrosstied,afailureofoneloopofRHRinoneoftheunitswouldstillallowasufficientnumberofloopstocoolbothRev.46,06/939.1-28 JI SSES-FSARreactorsandthespentfuelpools.Inthiscase,theunitprovidingspentfuelpoolcoolingwouldutilizeAlternateShutdownCoolingforlong-termdecayheatremovalfromthereactor.TheotherunitwouldutilizethenormalShutdownCoolingmode.Duringspecificplantevolutions,suchastransferoffuelintofuelcasks,thepoolswillnotbecrosstied.Theseevolutionswillbeprocedurallycontrolledtoensurethatsufficientcoolingsystemsareavailablegiventheplantconfigurationatthetimeoftheevolution.AnevaluationoftheimpactsofoperatingtheRHRFPCmodeontheUltimateHeatSink(UHS)wasperformedasaseparateevaluationoftheminimumheattransfercasediscussedinSubsections9.2.7.3.1and9.2.7.3.6.Theresultsofthisevaluationindicatethatthespraypond(UHS)willbemaintainedbelowthedesignmaximumtemperatureunderworstcaseaccidentconditions.AdditionaldetailsonthedesignoftheRHRFPCmodeareprovidedinSections5.4.7.1.1.6,5.4.7.2.6C,and9.1.3.1C.ProvisionstominimizeandmonitorleakagefromthefuelpoolaredescribedinSubsection9.1.2.3.Makeupforevaporativeandsmallleakagelossesfromthefuelpoolisnormallysuppliedfromthecondensatetransfersystemtotheskimmersurgetanksofeachunit.Theintermittentflowrateisapproximately50gpmtoeachsurgetank.Thewaterlevelinthespentfuelstoragepoolismaintainedataheightwhichissufficienttoprovideshieldingforrequiredbuildingoccupancy.Radioactiveparticulatesremovedfromthefuelpoolarecollectedinfilterdemineralizerunitsinshieldedcells.Forthesereasons,,theexposureofstationpersonneltoradiationfromthespentfuelpoolcoolingandcleanupsystemisnormallyminimal.FurtherdetailsofradiologicalconsiderationsaredescribedinChapter12.AnevaluationoftheradiologicaleffectofaboilingfuelpoolispresentedinAppendix9A.9.1.3.4InsectionandTestinReuirementsNospecialtestsarerequiredbecauseatleastonepump,heatexchanger,andfilterdemineralizerarecontinuouslyinoperationwhilefuelisstoredinthepool.Theremainingcomponentsareperiodicallyoperatedtohandleincreasedheatloadsduringrefueling.Rev.46,06/939.1-(29)

SSES-FSARThepoollinerleakdetectiondrainvalvesareperiodicallyopenedandtheleakrateestimatedbythevolumetricmethod.Gasordyepressuretestingfrombehindthelinerplatemaybeperformedtolocatealinerplateleak.Routinevisualinspectionofthe-systemcomponents,instrumentation,andtroublealarmsisprovidedtoverifysystemoperability.ComponentsandpipingoftheFPCCSdesignedperASMEBoilerandPressureVesselCode,SectionIII,Class3arein-serviceinspectedasdescribedinSection6.6.ThesystemwillbepreoperationallytestedinaccordancewiththerequirementsofChapter14.Rev.46,06/939.j.-(30)

SSES-FSARswitchgearandloadcenterroomcoolers,whicharenormallysuppliedbythecontrolstructurechilledwatersysteminUnit1orthedirectexpansion(DX)coolingsysteminUnit2)requiredduringnormalandemergencyconditionsnecessarytosafelyshutdowntheplant.TheESWSisdesignedtotakewaterfromthespraypond(theultimateheatsink),pumpittothevariousheatexchangersandreturnittothespraypondbywayofanetworkofspraysthatdissipatetheheattotheatmosphere,TheESWSisrequiredtosupplycoolingwaterto:a)TheRHRpumproomunitcoolerandthemotorbearingoilcoolerofeachRHRpumpduringallmodesofoperationoftheRHRsystem.b)Alltheheatexchangersassociatedwiththefourdieselgeneratorsalignedtothesystemduringoperationandtestmodes,exceptforthegovernoroilcoolers.c)Theroomcoolersforthecorespray(CS)pumps,thehighpressurecoolantinjection(HPCI)pumps,andreactorcoreisolationcooling(RCIC)pumpsduringtheoperationofthesesystems.d)Thecontrolstructurechiller,theUnit2emergencyswitchgearcoolingcondensingunit,reactorbuildingclosedcoolingwater(RBCCW)heatexchangers,andtheturbinebuildingclosedcoolingwaterheatexchanger(TBCCW)duringemergencyoperation.e)Thespentfuelpoolstoprovidemake-upforevaporativelossesduringoperationofthenormalfuelpoolcoolingsystemorRHRFuelPoolCooling(RHRFPC)mode,aswellas,fillingthespentfuelpoolsinsupportofRHRFPC.TheESWSisalsocapableofsupplyingmake-upforpostulatedboilingconditionsasdescribedinAppendix9AforaSeismicEvent.TheESWSstartsautomaticallywithinapprox.40-100secondsafterthedieselgeneratorsreceivetheirstartinitiationsignal.TheESWScanalsobestartedmanuallyfromeitherthemaincontrolroomorfromoneofthetworemoteshutdownpanels.(i.e~,ESWloopAcanonlybestartedfromtheUnit2remoteshutdownpanelandESWloopBcanonlybestartedfromtheUnit1remoteshutdownpanel.)Rev.47,06/949.2-13

~o

~~~~~~SSES-FSARInordertoavoidhavingunacceptablevoltagesduetotheRHRorCSpumpsstartingsimultaneouslywiththeESWpumps,theESWloadsequencetimerisreinitialized,butonlyiftheESWpumpshavenotstartedbeforetheRHRorCSpumps.TheESWSisdesignedtooperateduringanyofthefollowingconditions:a)LossofoffsitepowerRev.47,06/949.2-(14) a~

~tI~~~SSES-FSARTABLE9.2-3DEFINITIONOFESWFLOWSFORUNITS1842Page1of2ComponentNo.ofUsersPerLoopU1U2Min.Req'dESWFlowPerUser(GPM)Min.Req'd.ESWLoopFlowForDBAand1LoopFailedTypicalMin.ESWLoopF)owNon.Accidentw/1LoopOperatingandServiceWaterAvailableTypicalMin.'"ESWSafeShutdownFlow-2LoopsOperatingandBothUnitsServiceWaterNotAvailableA(B)B(A)1)Standby'"DieselGeneratorHeatExchangers4commontotal1210(A,B,C,D)1254(E)'"4840(4884)'"4840(4SS4)'"4840(4884)'"2)RHRPumpRoomUnitCoolers4003)RHRPumpMotorBearingOilCooler4)CoreSprayPumpRoomUnitCoolers1442414424144241445)HPCIPumpRoomUnitCoolers10202020206)RCICPumpRoomUnitCoolers10202020207)ControlStructureChiller1commonperloop7407407408)EmergencySwitchgearCoolingCondensingUnit7272729)RBCCWheatexchangeru'400280010)TBCCWheatexchanger"'4549011)MakeuptoFuelPools'"60120120TOTALLoopFlow(GPM)6380(6424)'"5448(5492)'"6380(6424)'"3898Rev.47,06/94 t~>.a.~-'

SSES-FSARPage2of2TABLE9.2-3(Continued)DEFINITIONOFESWFLOWSFORUNITS1BE21)Ononelooponly.2)Valveinparenthesisiswithanythree(3)ofA,B,C5Dunitsinserviceinconjunctionwith"E"unit.3)TheDieselGenerator"E"flowrateshownonthistableisbasedonthecontinuousdutyratingofthedieselgenerator(5000kw)~4)BothloopsofESWarealignedtotheD/G's.Itispreferredthatonepumpperloopberunduringnormaloperations.However,intheeventofaDBAandasinglefailureinESW,oneloopwillbeavailabletosupplythedesignflowtotheDieselGenerator.5)ThiscolumnillustratestheESWsystemsabilitytosupplyDBAflowsinadditiontosupplyingTBCCWandRBCCWwithbothloopsoperating.Theactualflowratesineachloopwillvaryslightlybecauseofthecrosstieatthediesels(i.e.the"B"loopwillpasssomeflowtotheD/G's).I6)Themake-uprateshownhereisconservativelybasedonanon-mechanisticboilingspentfuelpool(seeSubsection9.1.3.1).Theflowrateformake-upofevaporativelossesduringRHRFPCoperationwouldbesignificantlyless.Rev.47,06/94 c>0)~~

SSES-FSARwhichisinthecontrolroom,andeachpumpchamberisprovidedwithalowlevelsubmergenceswitchwhichalarmsinthecontrolroom.9.2.5.6PieCrackLeakaeDetectionLeakagefromtheESWScanbedetectedbyoneofseveralmethodsdependingonlocation.LeakagefrompipingwithintheESSWPumphousedrainsintoapitwhichisequippedwithalevelswitchtoalarmonhighwater.Theyard.pipingfromtheESSWpumphousetothepumpdischargeflowelementsiscontainedinaguardpipewhichdrainsbacktotheESSWPumphouseandintothesamepitasdescribedabove.Theremainingyardpipingislocatedinahightrafficareaandthepresenceofasignificantleakwillbevisuallyapparent.LeakdetectionwithintheReactorBuildings,ControlStructureandDieselGeneratorBuildingsdiffersdependingonthelocation.Seismicallyanalyzedroomflooddetectorsareusedinthelowestelevations,suchas,theRHR,CoreSpray,HPCI,RCICandTBCCWHeatExchangerrooms.FlooddetectionfortheroomscontainingESWlinessupplyingtheRBCCWheatexchangers,ControlStructureChillers,Unit2DxunitsandFuelPoolMakeupisnotfeasiblenordesirable,sincethelinesarelocatedinupperelevationsoftheReactorBuildingandControlStructure.Intheseareas,floordrainsroutetheleakagetoradwasteviaeithertheReactorBuildingorTurbineBuildingsumps.Theexcessiveinfluentintotheradwastesystemwillalertoperatorstoapipeleak.9.2.6RHRSERVICEWATERSYSTEM9.2.6.1DesinBasesTheResidualHeatRemovalServiceWaterSystem(RHRSWS)hasasafetyrelatedfunctionandisanengineeredsafeguardsystemdesignedtosupplycoolingwatertotheresidualheatremoval(RHR)heatexchangersofbothunits.TheRHRSWSisdesignedtotakewaterfromthespraypond(theultimateheatsink),pumpitthroughtheRHRheatexchanger,andreturnittothespraypondbywayofaspraynetworkthatdissipatestheheattotheatmosphere.TheRHRSWSisdesignedtoprovideareliablesourceofcoolingwaterforalloperatingmodesoftheRHRsystemincludingheatremovalunderpost-accidentconditions,RHRFuelPoolCooling(RHRFPC)followingaseismicevent,andalsotoprovidewatertofloodthereactorcoreortheprimarycontainmentafteranaccident,shoulditbenecessary.Rev.47,06/949.2-19 I~(~SSES-FSAR9.2.7ULTIMATEHEATSINKTheultimateheatsinkhassafetyrelatedfunctionsandprovidescoolingwaterforuseintheEngineeredSafeguardServiceWatersystem,describedinSubsections9.2.5and9.2.6,duringESSWtesting,normalshutdown,andaccidentconditions.9.2.7.1DesinBasesTheultimateheatsinkiscapableofprovidingsufficientcoolingwaterwithoutmakeuptothespraypondforatleast30daysto(a)permitsimultaneoussafeshutdownandcooldownofbothnuclearreactorunitsandmaintaintheminasafeshutdowncondition,(b)mitigatetheeffectsofanaccidentinoneunit,permitsafecontrolandcooldownoftheotherunit,andmaintainitinasafeshutdownconditionor(c)permitsimultaneoussafeshutdownandcooldownofbothunitsandmaintaintheminsafeshutdownwhileprovidingadequatecoolingtobothspentfuelpoolsfollowingaseismicevent.Continuedcoolingbeyond30daysisensuredbyuseofthemakeuppumpstokeepthepondatnormalwaterlevel.ThemakeuppumpsaredesignedtooperatebelowthehistoricminimumwaterleveloftheSusquehannaRiver.Intheeventthatmakeupwaterfromthemakeuppumpsisnotavailable,additionalprovisionswillbemadeinthe30daysavailabletoassurecontinuedcoolingoftheemergencyequipmentbeyond30days.Theseprovisionsincludebutarenotlimitedto:re-establishingmakeuppumpflowtothespraypond,emptyingthecoolingtowerbasinsintothespraypond,truckinginwaterfromneighboringwatersources(suchastheSusquehannaRiver),andprovidingtemporarypumpsand/orlinestopumpwaterfromneighboringwatersources(suchastheSusquehannaRiver,onsitestoragetanks,wellwater,etc.)'.ThisisincompliancewithNRCRegulatoryGuide1.27Rev.2asdiscussedinSection3.13.Theultimateheatsinkisalsocapableofprovidingenoughcoolingwaterwithoutmakeup,foradesignbasisLOCAinoneunitwiththesimultaneousshutdownoftheotherunit,for30dayswhileassumingaconcurrentSSE,singlefailure,and.lossofoffsitepower.ThiseventisevaluatedinSubsection9.2.7.3.1.Theultimateheatsinkconsistsofatleastonehighlyreliablewatersourcewithacapabilitytoperformthesafetyfunctionrequiredaboveduringandafteranyoneofthefollowingpostulateddesignbasisevents:a)Themostseverenaturalphenomena,includingthesafeshutdownearthquake,tornado,flood,ordroughttakenindividuallyRev.47,06/949.2-25

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SSES-FSARPage1of1TABLE9.2-8SUSQUEHANNAPONDWATERALLOWANCESLossDescriptionWaterAllowance(x10'al)a)Evaporationduetoheatdissipationdutyformaximumwaterlosscase7.95b)Driftfromwindformaximumwaterlosscase1.15c)Percolationthroughthepondlining0.3d)SystemchargingvolumeNegligiblee)Maximumsolarevaporationlosses1.85f)Lossesresultingfromwaveactionul0g)Lossesresultingfromsedimentation'"1.0h)Fuelpoolmakeup'"5.0i)Acontingencyforwaterqualityconsiderations2.7TotalPondVolumeRequired19.95TotalPondVolumeProvided25.0Basedondesignprovisionsforprotectionfromthisloss.(2)Negligiblesedimentationisanticipated.Thevaluegivencorrespondsto6in.ofponddepth,whichisaconservativeallowancebetweencleaningperiods.(3)Foradditionalconservatism,thisvalueassumesboilingofthefuelpoolsconsistentwiththenon-mechanisticboilingpoolanalysisinAppendix9A.Rev.35,07/84 SSES-FSARAPPENDIX9AANALYSISFORNONSEISMICSPENTFUELPOOLCOOLINGSYSTEMSAsdescribedinSubsection9.1.3theSpentFuelPool(SFP)CoolingSystemsaredesignedasnon-sei'smicCategoryI,QualityGroupCsystems.Consequently,theradiologicalconsequencesofalossofspentfuelpoolcoolingduetoaseismiceventareevaluated.InordertoperformthisanalysisitisnecessarytoassumetheSFPwillboileventhoughSection9.1.3.3establishesthatthedesignbasisoftheplantforthiseventistopreventboilingthroughtheuseoftheRHRFPCmode.Sincethecoolingsystemsforbothunitsarecross-connectedandincloseproximityitwasassumedthataseismiceventcausesthelossofcoolingtobothspentfuelpools.Inaddition,inordertomaximizeboth'heheatloadsandtheiodineinventoriesinthepools,refuelingswithin135dayswerepostulated.(Periodoftimebetweenoutagesisnominally180days,thususeof135daysisconservative.)Thelossofcoolingwasassumedduringthesecondrefueling,justafterisolationofthepools(i.e.,refuelingandcaskpitgatesinstalled).TheRHRsystemisassumedtonotbeavailableforcoolingtheSFPeventhoughitwouldbeabletoprovidecoolinginresponsetothisevent.Thus,itisassumedthatthepoolswillboil.Theanalysisinvolvedanevaluationofthetimetopoolboiling,theabilitytomaintainwaterlevelifthepoolboils,andthethyroiddoseconsequencesattheLPZboundaryduetoiodinereleasesfromtheboilingpools.TheassumptionsusedinthisanalysiswereconsistentlychosentobeconservativeandboundingsimilartothoseinRegulatoryGuidesfordesignbasisaccidents(e.g.,RegulatoryGuides1.3,1.25,etc.).Thecombinationofallofthesedesignbasisassumptionsoccurringatthesametimewouldbeextremelyunlikely,makingthisaccidentasanalyzed,oneofverylowprobability.Manyoftheassumptionsareconsideredtobeoverlyconservative.Forexample,operatingexperiencewithpresentBWRfuels(Reference9A-1)indicatesthattheassumptionof700pCi/sec(fullpowerdesignbasisleakagerate)isconservativefordeterminingreactorcoolantconcentrationsduringoperatingconditions.ThissameleakageratewillbeassumedforthefuelintheSFP,whichisevenmoreconservative.EventhoughspikingfactorshaveyettobeobservedforatemperatureriseinSFPs,spikingfactorshavebeenutilized.Amorerealisticevaluationofthisaccidentwouldresultinreleasesofradioactivity,ifany,manyordersofmagnitudebelowthecalculatedvalues.Therealisticreleaseswouldbewellbelowthe10CFR50AppendixIrelatedTechnicalSpecifications,indicatingthatsuchanincidentisoflittleornoconsequence.Rev.46,06/939A-1 SSES-FSARThepoolswillbeoperatedinamannerwhichwillensurethattheywillnotboiluntilatleast25hoursafterthelossofcooling.Sincecoolingisassumednottoberestoredbeforethepoolboils,makeupwaterfromtheCategoryIEmergencyServiceWaterSystemisassumedtobeaddedtothepoolatarateequaltotheboilofftokeepthefuelcoveredwith23feetofwateratalltimes.AsshowninTable9A-1,thethyroiddoseconsequencesoftheboilingpool,withoutoperationoftheStandbyGasTreatmentSystem,arewellbelowtheguidelinevaluesof10CFR100andthe1.5REMthyroidguidelineofRegulatoryGuide1.29.Thefollowingassumptionswereusedtocalculatetheheatgenerationandboilingrate.l.Eachfuelpoolisfullwith2850fuelassemblies.Themaximumexpecteddischargebatchsizeof280assemblieswasusedforthemostrecentoffloadineachpool.Theearlieroffloadswerebasedon256assemblybatchsizes.Todeterminetheheatloadandthusboilingevaporationrate,sequentialrefuelings129daysapartareassumed.Theeventisassumedtooccur6daysafterthesecondunitis,shutdown.Sixdaysisconservativelychosenastheminimumtimetounload280assembliesandreinstallthefuelpoolgates(thusisolatingthepool).Therefore,oneunit'sfuelpoolinventoryisassumedtohavedecayedfor6days.Actualsequentialrefuelingsoccurapproximately180daysapart.Thenormaltimetodefuel280assembliesis8days.Theseassumptionsmaximizetheheatloadintherecentlydefueledpoolandthustheboilingevaporationrate.Theanalyseswereperformedforpoweruprateconditions.2.ThedecayheatwascalculatedusingtheANSI/ANS-5.1-1979decayheatstandard.Thisstandardincludesmethodologyforcalculatingthedecayuncertainty.Allvaluesofthedecayheatinthissectionareequaltothenominalvalueplustwostandarddeviations.3.Todetermineaconservativeboilingevaporationrateforpurposesofthisradiologicalevaluation,allheatgeneratedbythefuelisassumedtobeabsorbedbythewaterinordertominimizethetimetoboiling.Noheatislosttothesurroundingsbyconductionthroughtheconcreteandsteel,orbyevaporation.Thetemperaturegradientsfromthefuelatthebottomofthepooltothecoolerwateratthetopwillcreateconvectivewaterandheatcurrentswhichwillthoroughlymixthewater,andpromoteanevendistributionofheatratherthanlocalizedpointsofsurfaceboiling.Rev.46,06/939A-2 SSES-FSAR4.Theactivityreleaseratefromthepooldependsontheevaporationrateandtheiodinecarryoverfractionatthepoolsurface.Theevaporationratepriortoboilingisboundedbytheevaporationrateatinitiationofboiling.Itisconservativelyassumedthattheevaporationratepriortoboilingisthesameasthatduringboiling.Rev.46,06/93 rQl0$~'l'.'

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