ML18026A537

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
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)

Text

PR.I(3RIEY1(ACCELERATED RIDSPROCESSIXREGULATORY INFORMATION DISTRIBUTION SYSTEM(RIDS)ACCESSION NBR:9502270258 DOC.DATE:

95/02/21NOTARIZED:

NOFACIL:50-387 Susquehanna SteamElectricStation,Unit1,Pennsylva 50-388Susquehanna SteamElectricStation,Unit2,Pennsylva AUTH.NAMEAUTHORAFFILIATION BYRAM,R.G.

Pennsylvania Power&LightCo.RECIP.NAME RECIPIENT AFFILIATION DocumentControlBranch(Document ControlDesk)

SUBJECT:

ForwardsFSARchangedelineating useofRHRfuelpoolcoolingmodeofoperation tomitigatelossofnormalspentfuelpoolcoolingsysinresponsetoseismicevent,per commitment madevia941228ltr.DISTRIBUTION CODE:AOOIDCOPIESRECEIVED:LTR lENCL3SIZE:5TITLE:ORSubmittal:

GeneralDistribution NOTES:DOCKETN050003870500038805000387RECIPIENT IDCODE/NAME PDl-2LAPOSLUSNY,C INTERNAL:

ACRSNRR/DRCH/HICB NRR/DSSA/SRXB OGC/HDS2EXTERNAL:

NOACNOTES:COPIESLTTRENCL11116611111011RECIPIENT IDCODE/NAME PD1-2PD/D/NUDOCS-ABSTRACT NRCPDRCOPIESLTTRENCL1111111111NOTETOALL"RIDS"RECIPIENTS:

PLEASEHELPUSTOREDUCEO'ASTE!CONTACTTIIE DOCL'ifENTCONTROL DESk,ROOAIPI-37(EXT.504-0033)TOELIXIINiATEYOURNAiILFROifDISTRIBUTION LISTSI'ORDOCI.'4IEN'I'SYOL'ON"I'L'I'.D!

TOTALNUMBEROFCOPIESREQUIRED:

LTTR18ENCL17

~0Pennsylvania Power8LightCompanyTwoNorthNinthStreet~Allentown, PA18101-1179

~610/774-5151 FEB211995RobertG.ByramSeniorVicePresident

-Nuclear610/774-7502 Fax:610/774-5019 U.S.NuclearRegulatory Commission Attn.:DocumentContr'olDeskMailStationP1-137Washington, D.C.20555SUSQUEHANNA STEAMELECTRICSTATIONFSARCHANGE:RHRFUELPOOLCOOLINGDocketNos.50-387and50-388

Reference:

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

DearSir:

Viathereferenced letter,PP&Lcommitted toprovideanFSARchangedelineating theuseoftheRHRFuelPoolCoolingmodeofoperation tomitigatethelossofnormalspentfuelpoolcoolingsysteminresponsetoaseismicevent.AcopyoftheFSARchangeisattachedforyouruseandinformation.

Althoughthischangehasbeenreviewedandapprovedinternally, PP&Listreatingthischangeaspreliminary pendingissuanceofthefinalNRCSafetyEvaluation onSpentFuelPoolCoolingissues.Uponissuanceofthatdocument, wewillresolveanydiscrepancies andformallyissuetheFSARchangeperournormalprocedures.

Ifyouhaveanyquestions ontheattachment, pleasecontactMr.J.M.Kennyat(610)774-7904.

Verytrulyyours,iR.G.yraAttachment CC:NRCRegionIMs.M.Banerjee, NRCSr.ResidentInspector

-SSESMr.C.Poslusny, Jr.,NRCSr.ProjectManager-OWFNMr.J.Shea,NRCProjectManager-OWFNIDR950227ADOCK05000>8PDP NOTE:Pagenumbersinparenthesis (Iindicateaspill-over frompreviouspages.TheydonotcoincidewiththetextonthatpageintheFSAR....9502270258 SSES-FSAR averagelifeexpectancy manytimestheresidence timeofafuelloading.1.2.2.3.2 ReactorVesselandInternals Thereactorvesselcontainsthecoreandsupporting structure; thesteamseparators anddryers;thejetpumps;thecontrolrod,guidetubes;distribution linesforthefeedwater, corespray,andstandbyliquidcontrol;theincoreinstrumentation; andothercomponents.

Themainconnections tothevesselincludethesteamlines,thecoolantrecirculation lines,thefeedwater lines,thecontrolroddrivehousings, andtheECCSlines.Thereactorvesselisdesignedandfabricated inaccordance withapplicable codesforapressureof1250psig.Thenominaloperating pressureis1020psiainthesteamspaceabovetheseparators.

Thevesselisfabricated ofcarbonsteelandiscladinternally withstainless steel(exceptforthetopheadwhichisnotclad).Thereactorcoreiscooledbydemineralized waterthatentersthelowerportionofthecoreandboilsasitflowsupwardaroundthefuelrods.Thesteamleavingthecoreisdriedbysteamseparators anddryers,locatedintheupperportionofthereactorvessel.Thesteamisthendirectedtotheturbinethroughfourmainsteamlines.

Eachsteamline isprovidedwithtwoisolation valvesinseries,oneoneachsideoftheprimarycontainment barrier.1.2.2.3.3 ReactorRecirculation SstemTheReactorRecirculation Systempumpsreactorcoolantthroughthecoretoremovetheenergygenerated inthefuel.Thisisaccomplished bytworecirculation loopsexternaltothereactorvesselbutinsidetheprimarycontainment.

Eachloophasonemotor-driven recirculation pump.Recirculation pumpspeedcanbevariedtoallowsomecontrolofreactorpowerlevelthroughtheeffectsofcoolantflowrateonmoderator voidcontent.1.2.2.3.4 ResidualHeatRemovalSstemTheResidualHeatRemovalSystem(RHRS)consistsofpumps,heatexchangers andpipingthatfulfillthefollowingfunctions:

a~b.Removalofdecayheatduringandafterplantshutdown.

Rapidinjection ofwaterintothereactorvesselfollowing alossofcoolantaccident, ataratesufficient torefloodthecoremaintainfuelcladdingbelowthelimitscontained in10CFR50.46.Thisisdiscussed inSubsection 1.2.2.4.Rev.47,06/941.2-14 SSES-FSAR c~Removalofheatfromtheprimarycontainment following aloss-of-coolant accident(LOCA)tolimittheincreaseinprimarycontainment pressure.

Thisisaccomplished bycoolingandrecirculating thewaterinsidetheprimarycontainment.

Theredundancy oftheequipment providedforthecontainment isfurtherextendedbyaseparatepartoftheRHRSwhichsprayscoolingwaterintothedrywell.,Thislattercapability isdiscussed inSubsection 1.2.2.4.12.

d.Provideforcoolingofthespentfuelpool(s)following aseismiceventwhichresultsinalossofnormalspentfuelpoolcooling,inconjunction withnormalshutdownofbothunits.1.2.2.3.5 ReactorWaterCleanuSstemRWCUAReactorWaterCleanupSystem,whichincludesafilterdemineralizer, isprovidedtocleanupthereactorcoolingwater,toreducetheamountsofactivated corrosion productsinthewater,andtoremovereactorcoolantfromthenuclearsystemundercontrolled conditions.

1.2.2.4SafetRelatedSstemsSafetyrelatedsystemsprovideactionsnecessary toassuresafeshutdown, toprotecttheintegrity ofradioactive materialbarriers, and/ortopreventthereleaseofradioactive materialinexcessallowable doselimits.Thesesystemsmaybecomponents, groupsofcomponents, systems,orgroupsofsystems.Engineered SafetyFeature(ESF)systemsareincludedinthiscategory.

ESFsystemshaveasolefunctionofmitigating theconsequences ofdesignbasisaccidents.

1.2.2.4.1 ReactorProtection SstemTheReactorProtection Systeminitiates arapid,automatic shutdown(scram)ofthereactor.Thisactionistakenintimetopreventexcessive fuelcladdingtemperatures andanynuclearsystemprocessbarrierdamagefollowing abnormaloperational transients.

TheReactorProtection Systemoverrides alloperatoractionsandprocesscontrols.

Rev.46,06/931.2-15 SSES-FSAR 1.2.2.4.2 Neutron-Monitorin SstemNotalloftheNeutronMonitoring Systemqualifies asanuclearsafetysystem;onlythoseportionsthatprovidehighneutronfluxsignalstotheReactorProtection Systemaresafetyrelated.Theintermediate rangemonitors(XRM)andaveragepowerrangemonitors(APRM),whichmonitorneutronfluxviain-coredetectors, signaltheReactorProtection Systemtoscramintimetopreventexcessive fuelcladtemperatures asaresultofabnormaloperational transients.

Rev.46,06/931.2-(16)

SSES-FSAR 3.1.2.1.5 SharingofStructures, Systems,andComponents Criterion 5Criterion Structures, systems,andcomponents important tosafetyshallnotbesharedamongnuclearpowerunitsunlessitcanbeshownthatsuchsharingwillnotsignificantly impairtheirabilitytoperformtheirsafetyfunctions, including, intheeventofanaccidentinoneunit,anorderlyshutdownandcooldownoftheremaining units.DesinConformance AlthoughSusquehanna SESUnits1and2sharecertainstructures, systems,andcomponents, sharingthemdoesnotsignificantly impairperformance oftheirsafetyfunctions.

Thefollowing safetyrelatedstructures aresharedbetweenbothunits:ControlStructure DieselGenerator Buildings ESSWPumphouse SprayPondSpentFuelPoolsThesafetyrelatedstructures aredesignedtoremainfunctional duringand,following themostseverenaturalphenomena.

Therefore sharingthesestructures willnotimpairtheirabilitytoperformtheirsafetyfunctions.

SeismicCategoryI'tructures whichhousesafetyrelatedsystemsandequipment arediscussed inSection3.8.Thesharedsystemswhichareimportant.

tosafetyarediscussed below;amoredetaileddiscussion

-maybefoundinthereferenced Subsections:

a)b)c)d)e)f)Emergency ServiceWaterSystemDieselGenerators UltimateHeatSink'(SprayPond)OffsitePowerSuppliesUnit1ACDistribution SystemResidualHeatRemoval(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-FSAR EmerencServiceWaterSstemESWSTheESWSisdesignedtoa)SupplycoolingwatertotheRHRpumpsandtheirassociated roomcoolersduringtheseveralnon-emergency modesofRHRpumpoperation suchasnormalshutdown, andhotstandby.b)Supplycoolingwatertothevariousdieselgenerator heatexchangers, RHRpumps,roomcoolers,RBCCWandTBCCWheatexchangers duringemergency shutdownconditions suchasaLOCA.c)SupplycoolingwatertotheRHRpumpsandtheirassociated roomcoolersduringaseismiceventthatresultsinalossofthenon-seismic CategoryIFuelPoolCoolingSystem.Duringthisevent,ESWSwouldalsosupplywatertothespentfuelpoolstomake-upforevaporative lossesandfillthespentfuelpoolstotheproperlevelneededtosupporttheRHRFPCmodeshouldthenormalmake-upsourcebeunavailable.

TheESWSpumpsarelocatedintheESWSpumphouse withtheRHRSWpumps.TheESWSpumphouse isdesignedasSeismicCategoryIandtheESWSconsistsoftworedundant loops(denotedAandB)eachcapableofproviding 100percentofthecoolingwaterrequiredbyalltheESFequipment ofbothUnits1and2simultaneously.

Thesystemisdesignedsothatnosingleactiveorpassivecomponent failurewillpreventitfromachieving itssafetyrelatedobjective.

Thesystemstartsautomatically onadieselstartsignal.Foradditional discussion, seeSubsection 9.2.5.DieselGenerators DieselGenerators A,B,CandDarehousedinaSeismicCategoryIstructure.

Theyareseparated fromeachotherbyconcretewallswhichprovidemissileprotection.

Additionally, asparedieselgenerator (DieselGenerator

'E')isprovidedwhichcanbemanuallyrealigned asareplacement foranyoneoftheotherfourdieselgenerators.

Thus,anyoneoftheotherdieselgenerators (A,B,CorD)canberemovedfromserviceforextendedmaintenance andtheDieselGenerator

'E'anbesubstituted sothattherearefouroperabledieselgenerators.

DieselGenerator

'E'shousedinitsownSeismicCategoryIstructure whichalsoprovidesmissileprotection.

Lossofoneofthefouraligneddieselgenerators willnotimpairthecapability tosafelyshutdownbothunits,sincethiscanbeRev.47,06/943017 SSES-FSAR donewiththreedieselgenerators.

Foradditional discussion, seeSubsection 8.3.1.4.Fordescriptions oftheDieselGenerator FuelOilSystem,CoolingWaterSystem,AirStartingSystem,LubeOilSystem,andtheIntakeandExhaustSystemsseeSubsections 9.5.4,9.5.5,9'.6,9.5.7,and9.5.8respectively.

Formissileprotection seeSubsection 3.5.Separation isdiscussed inSections3.12and8.3.UltimateHeatSinkSraPondThespraypondprovidesthewaterforboththeESWSsystemandtheRHRSWsystems.ItistheultimateheatsinkforbothUnits1and2.ThereturnlinesfromtheESWSandtheRHRSWarecombinedandthetotalquantityofwaterfromboththesesystemsisdischarged throughspraynetworks, whichdissipate theheatbacktothepond.Therearetworedundant returnloops(AandB);eitheroneiscapableofhandlingthefullflowfromtheESWSandRHRSWwhenshuttingdowntwounitssimultaneously.

Eachreturnloopsuppliesaseparatespraynetworkandeach,ofthesenetworksisdividedintoalargeonecapableofdissipating theheatfromtheESWSandtheRHRSWfromtheRHRheatexchanger ononeunit,andasmalleronecapableofdissipating theheatfromtheRHRheatexchanger onthesecondunit.Thespraypondcontainssufficient watertomeettherequirements forshuttingdownoneunitintheeventofanaccidentandtopermitthesafeshutdownofthesecondunitforaperiodofthirtydayswithoutmakeup.Foradditional discussion seeSubsections 9.2.5and9.2.6.OffsitePowerSuliesThetwopreferred offsitepowersuppliesaresharedbybothunits.Thecapacityofeachoffsitepowersupplyissufficient tooperatetheengineered safetyfeaturesofoneunitandsafeshutdownloadsoftheotherunit.Foradditional discussion, seeSection8.2.Unit1ACDistribution SstemTheUnit1ACDistribution Systemisasharedsystembetweenbothunits,sincethecommonequipment (Emergency ServiceWater,StandbyGasTreatment System,ControlStructure HVAC,etc.)isenergized onlyfromtheUnit1ACDistribution System.Rev.47,06/943.1-8 SSES-FSAR TherearenoUnit2specificloadsenergized fromtheUnit1ACDistribution System.ThecapacityoftheUnit1ACDistribution Systemissufficient tooperatetheengineered safetyfeaturesononeunitandthesafeshutdownloadsoftheotherunit.ResidualHeatRemovalFuelPoolCoolinMode)WiththeSpentFuelPoolscrosstied, oneunit'sRHRsystemcanbeusedtocoolstoredspentfuelinbothspentfuelpools.Inthecrosstied configuration, theRHRFPCmodeofoneunitwilldrawsuctionfromthatunit'sskimmersurgetankandreturnthecooledflowtothebottomoftheunit'sfuelpool.Nodirectflowtoorfromtheoppositeunit'sfuelpoolwillbeaccomplished.

Withthepoolscrosstied andRHRFPCinoperation ononeoftheunitsadequatecoolingofbothpoolswillbeachieved.

Forfurtherdiscussions seeSubsections 5.4.7.1.1.6, 5.7.2.1,c, 9.1.3.1c, and9.1.3.3.3.1.2.2Protection byMultipleFissionProductBarriersQrouII3.1.2.2.1 ReactorDesinCriterion 10Criterion Thereactorcoreandassociated coolant,control,andprotection systemsshallbedesignedwithappropriate margintoassurethatspecified acceptable fueldesignlimitsarenotRev.47,06/94 SSES-FSAR 3)In-service Inspection 4)ReactorVesselandAppurtenances 5)ReactorRecirculation System5.25.45.43.1.2.4.4 ReactorCoolantMakeupCriterion 33Criterion Asystemtosupplyreactorcoolantmakeupforprotection againstsmallbreaksinthereactorcoolantpressureboundaryshallbeprovided.

Thesystemsafetyfunctionshallbetoassurethatspecified acceptable fueldesignlimitsarenotexceededasaresultofreactorcoolantlossduetoleakagefromthereactorcoolantpressureboundaryandruptureofsmallpipingorothersmallcomponents whicharepartoftheboundary.

Thesystemshallbedesignedtoassurethatforonsiteelectricpowersystemoperation (assuming offsitepowerisnotavailable) andforoffsiteelectricpowersystemoperation (assuming onsitepowerisnotavailable) thesystemsafetyfunctioncanbeaccomplished usingthepiping,pumps,,andvalvesusedtomaintaincoolantinventory duringnormalreactoroperation.

DesinConformance Theplantisdesignedtoprovideamplereactorcoolantmakeupforprotection againstsmallleaksintheRCPBforanticipated operational occurrences andpostulated accidentconditions.

Thedesignofthesesystemsmeetstherequirements ofCriterion 33.Forfurtherdiscussion, seethefollowing sections:

2)3)4)5)6)ReactorCoolantPressureBoundaryLeakageDetection Systems5.2ReactorCoreIsolation CoolingSystem5.4Emergency CoreCoolingSystem6.3ReactorVessel-Instrumentation andControl7.6MakeupDemineralizer System9.2Condensate StorageandTransferSystem9'3.1.2.4.5 ResidualHeatRemovalCriterion 34Criterion Asystemtoremoveresidualheatshallbeprovided.

Thesystemsafetyfunctionshallbetotransferfissionproductdecayheatandotherresidualheatfromthereactorcoreataratesuchthatspecified acceptable fueldesignlimitsandthedesignconditions ofthereactorcoolantpressureboundaryarenotexceeded.

Rev.46,06/933.1-39 SSES-FSAR Suitableredundancy incomponents andfeatures, andsuitableinterconnections, leakdetection, andisolation capabilities shallbeprovidedtoassurethatforonsiteelectricpowersystemoperation (assuming offsitepowerisnotavailable) andforoffsiteelectricpowersystemoperation (assuming onsitepowerisnotavailable) thesystemsafetyfunctioncanbeaccomplished, assumingasinglefailure.DesinConformance RHRsystemprovidesthemeanstoremovedecayheatandresidualheatfromthenuclearsystemsothatrefueling andnuclearsystemservicing canbeperformed.

MajorRHRsystemequipment consistsoftwoheatfourmainsystempumps.Theequipment isassociated valvesandpiping,andtheinstrumentation areprovidedforpropersystemexchangers andconnected bycontrolsandoperation.

Twoindependent loopsarelocatedinseparateprotected areas.TheRHRsystemisdesignedforfourmodesofoperation:

a)Shutdowncoolingb)Suppression poolcooling(alsocontainment spray)c)Lowpressurecoolantinjection.

d)FuelPoolCoolingBothnormalacpowerandtheauxiliary onsitepowersystemprovideadequatepowertooperatealltheauxiliary loadsnecessary for,plantoperation.

Thepowersourcesfortheplantauxiliary powersystemaresufficient innumber,andofsuchelectrical andphysicalindependence thatnosingleprobableeventcouldinterrupt allauxiliary poweratonetime.Theplantauxiliary busessupplying powertoengineered safetyfeaturesandreactorprotection systemsandauxiliaries requiredforsafeshutdownareconnected byappropriate switching tothefouralignedstandbydiesel-driven generators locatedintheplant.Eachpowersource,uptothepointofitsconnection totheauxiliary powerbuses,iscapableofcompleteandrapidisolation fromanyothersource.Loadsimportant toplantoperation andsafetyaresplitanddiversified betweenswitchgear

sections, andmeansareprovidedfordetection andisolation ofsystemfaults.Theplantlayoutisdesignedtoeffectphysicalseparation ofessential bussections, standbygenerators, switchgear, interconnections, feeders,powercenters,motorcontrolRev.46,06/933.1-40 SSES-FSAR centers,andothersystemcomponents.

Fourstandbydieselgenerators (A,B,C,andD)andasparedieselgenerator (E),whichcanbemanuallyrealigned asareplacement foranyoneoftheotherfourdieselgenerators areprovided.

Thesedieselgenerators supplyasourceofelectrical powerwhichisself-contained withintheplantandisnotdependent onexternalsourcesofsupply.Thestandbygenerators produceacpoweratavoltageandfrequency compatible withthenormalbusrequirements foressential equipment withintheplant.Thestandbydieselgenerator systemishighlyreliable.

Anythreeofthefivegenerators areadequatetostartandcarrytheessential loadsrequiredforasafeandorderlyshutdown.

TheRHRsystemisadequatetoremoveresidualheatfromthereactorcoretoensurefuelandRCPBdesignlimitsarenotexceeded.

Redundant reactorcoolantcirculation pathsareavailable toandfromthevesselandRHRsystem.UseofRHRintheFuelPoolCoolingmodewillnotadversely impacttheabilityofRHRtoperformReactorCoreCoolingfunctions asdiscussed inSubsections 5.4.7.1.1.6, 5.4.7.2.6c, 9.1.3.1c, and9.1.3.3.Redundant onsiteelectricpowersystemsareprovided.

ThedesignoftheRHRsystem,including itspowersupply,meetstherequirements ofCriterion 34.Forfurtherdiscussion, seethefollowing sections:

1)2)3)4)5)6)7)ResidualHeatRemovalSystemEmergency CoreCoolingSystemsEmergency CoreCoolingSystemsInstrumentation andControlAuxiliary PowerSystemStandbyacPowerSupplyandDistribution StationServiceWaterAccidentAnalysis5.46.37'8.38.39.215.03.1.2.4.6 Emergency CoreCoolingCriterion 35Criterion Asystemtoprovideabundantemergency corecoolingshallbeprovided.

Thesystemsafetyfunctionshallbetotransferheatfromthereactorcorefollowing anylossofreactorcoolantataratesuchthat(1)fuelandcladdamagethatcouldinterfere withcontinued effective corecoolingisprevented and(2)cladmetal-water reactionislimitedtonegligible amounts.Rev.46,06/933.1-41 SSES-FSAR Suitableredundancy incomponents andfeatures, andsuitableinterconnections, leakdetection, isolation, andcontainment capabilities shallbeprovidedtoassurethatforonsiteelectricpowersystemoperation (assuming offsitepowerisnotavailable) andforoffsiteelectricpowersystemoperation (assuming onsitepowerisnotavailable) thesystemsafetyfunctioncanbeaccomplished, assumingasinglefailure.Rev.46,06/933.X-(42)

SSES-FSAR DesinConformance Theemergency safeguard servicewatersystem,whichcomprises boththeEmergency ServiceWatersystemandtheResidualHeatRemovalServiceWatersystem,providescoolingwaterfortheremovalofexcessheatfromallstructures, systems,andcomponents whicharenecessary tomaintainsafetyduringallabnormalandaccidentconditions.

Theseincludethestandbydieselgenerators, theRHRpumpoilcoolersandsealwatercoolers,thecorespraypumproomunitcoolers,RCICpumproomunitcoolers,theHPCIpumproomunitcoolers,theRHRheatexchangers, RHRpumproomunitcoolers,emergency switchgear andloadcenterroomcoolersandthecontrolstructure chiller.ItalsoprovideswatertotheRHRpumpsandabovementioned roomunitcoolersduringaseismiceventtosupportoperation oftheRHRFuelPoolCooling(RHRFPC)mode.Make-upwatertotheSpentFuelPool(SFP)isprovidedduringaseismiceventinordertomake-upforevaporative lossesandfillingoftheSFPinsupportofRHRFPC.RHRSWprovidesthecoolingwatertotheRHRheatexchangers fortheRHRFPCmode.Theengineered safeguard servicewatersystemisdesignedtoSeismicCategoryIrequirements.

Redundant safetyrelatedcomponents servedbytheengineered safeguard servicewatersystemaresuppliedthroughredundant supplyheadersandreturnedthroughredundant discharge orreturnlines.Electricpowerforoperation ofredundant safetyrelatedcomponents ofthissystemissuppliedfromseparateindependent offsiteandredundant onsitestandbypowersources.Nosinglefailurerendersthesesystemsincapable ofperforming theirsafetyfunctions.

Referenced Subsections areasfollows:1)2)3)4)5)acPowerSystemsServiceWaterSystemEngineered ServiceWaterSystemRHRServiceWaterSystemUltimateHeatSink8.3.19.2.19.2.59.2.69.2.73.1.2.4.16 Inspection ofCoolingWaterSystemCriterion 45Criterion Thecoolingwatersystemshallbedesignedtopermitappropriate periodicinspection ofimportant components, suchasheatexchangers andpiping,toassuretheintegrity andcapability ofthesystem.Rev.46,06/933.1-51 SSES-FSAR DesinConformance Theengineered safeguard servicewaterandtheRBCCWsystemsaredesignedtopermitappropriate periodicinspection inordertoensuretheintegrity ofsystemcomponents.

Rev.46,06/933.1-(52)

SSES-FSAR DesinConformance NewFuelStoraeNewfuelisplacedindrystorageinthenewfuelstoragevaultthatislocatedinsidethereactorbuilding.

Thestoragevaultwithinthereactorbuildingprovides*adequate shielding forradiation protection.

Storageracksprecludeaccidental criticality (seeSubsection 3.1.2.6.3).

Thenewfuelstorageracksdonotrequireanyspecialinspection andtestingfornuclearsafetypurposes.

However,theracksareaccessible forperiodicinspection.

SentFuelHandlinandStoraeIrradiated fuelisstoredsubmerged inthespentfuelstoragepoollocatedinthereactorbuilding.

Fuelpoolwateriscirculated throughthefuelpoolcoolingandcleanupsystemtomaintainfuelpoolwatertemperature, purity,waterclarity,andwaterlevel.Storageracksprecludeaccidental criticality (seeSubsection 3.1.2.6.3).

Reliabledecayheatremovalisprovidedbythefuelpoolcoolingandcleanupsystem.Thepoolwateriscirculated throughthesystemwithsuctiontakenfromthepoolandisdischarged throughdiffusers atthebottomofthefuelpool.Poolwatertemperature ismaintained below125'Fwhenremovingthemaximumnormalheatload(MNHL)fromthepoolwiththeservicewatertemperature atitsmaximumdesignvalue.TheRHRsystemwithitssubstantially largerheatremoval"capacitycanbeusedasabackupforfuelpoolcoolingwhenheatloadslargerthanthecapability ofthefuelpoolcoolingsystemsareinthespentfuelpools.RHRalsoprovidesreliabledecayheatremovaltothespentfuelpoolsifthenormalfuelpoolcoolingsystemislostduetoaSeismicevent.Operation oftheRHRFuelPoolCooling(RHRFPC)modewillprovideseismicCategoryI,Class1Ecoolingtothespentfuelpoolssothatboilingofthespentfuelpoolsdoesnotoccurasaresultofaseismicevent.ESWprovidesSeismicCategoryI,Class1Emake-upinsupportofRHRFPC.Highandlowlevelswitchesindicatepoolwaterlevelchangesinthemaincontrolroom.Fissionproductconcentration inthepoolwaterisminimized byuseofthefiltersanddemineralizer.

Thisminimizes thereleasefromthepooltothereactorbuilding.

Rev.46,06/933.1-60 SSES-FSAR Thereactorbuildingventilation systemandthesecondary containment aredesignedtolimitthereleaseofradioactive materials totheenvironsandensurethatoffsitedosesarelessthanthelimitingvaluesspecified in10CFR100duringoperation andallaccidentconditions.

Nospecialtestsarerequired, becauseatleastonepumpandheatexchanger arecontinuously inoperation whilefuelisstoredinthepool.Duplicate unitsareoperatedperiodically tohandlehighheatloadsortoreplaceaunitforservicing.

Routinevisualinspection ofthesystemcomponents, instrumentation, andtroublealarmsareadequatetoverifysystemoperability.

TestingoftheRHRFPCmodeisaccomplished throughroutinetestingofthepumpsandheatexchangers insupportofothermodesofRHR.Thevalvessupporting theRHRFPCmodeareroutinely strokedtoconfirmproperoperation ofthevalvesfortheirRHRFPCmission.Rev.46,06/933.1-(61)

SSES-FSAR fuel.Theseinterlocks precludeanyloadsuspended fromthiscranefromtippingoveronthestoredfuelintheeventofacranefailure.The5tonauxiliary hooksuspended fromthesamecranetrolleyisprevented frompassingoverstoredfuelwhenfuelhandlingisnotinprogressbyadministrative controls'here arenoplannedtransfe'rs ofloadsheavierthananewfuelelementoverthestoredfuel.(3)

Reference:

PositionC.8.ASeismicCategoryImakeupwatersupplyfromeachemergency servicewaterloopispermanently connected to,eachspentfuelpoolbytwoindependent SeismicCategoryIpipingroutes.Themake-upisprovidedforfillingthe-spentfuelpooltotheproperleveltosupportoperation oftheRHRfuelpoolcoolingmode,andtoprovideformake-upfromevaporative lossesduringcoolingbyRHR.Themake-uprateissizedbasedonboilingsoastobeconservative.

ThenormalmakeupsystemtothefuelpoolisnotSeismicCategoryI.ReulatoGuide1.14REACTORCOOLANTPUMPFLY-WHEEL INTEGRITY Revision1Auust1975Notapplicable.

ReulatorGuide1.15-TESTINGOFREINFORCING BARSFORCATEGORYICONCRETESTRUCTURES Revision1December281972Testingofreinforcing barsforCategoryIconcretestructures isincompliance withthisregulatory guide.ReulatorGuide1.16-REPORTING OFOPERATING INFORMATION-APPENDIX ATECHNICAL SPECIFICATIONS Revision4Auust1975Inlieuofthepositions statedinthisRegulatory Guide,thereporting ofoperating information fortheSusquehanna SEScomplieswithTechnical Specifications and10CFR50.73.

ReulatorGuide1.17PROTECTION OFNUCLEARPOWERPLANTSAGAINSTINDUSTRIAL SABOTAGEJune1973Inlieuofthepositions statedinthisregulatory guide,theprotection ofSusquehanna SESagainstindustrial sabotagecomplieswith10CFR73.Rev.46,06/933.13-6 SSES-FSAR

Reference:

PositionC.l.dandC.l.g.Thenormalspentfuelpoolcoolingsystemisnon-seismic CategoryI.IfaseismiceventwouldoccurcoolingofthespentfuelisachievedbyuseoftheRHRFuelPoolCooling(RHRFPC)modeasdescribed insections5.4.7.1.1

',5.4.7.2.6c, 9.1.3.1,and9.1.3.3.EitherorbothoftwoSeismicCategoryIESWmakeupwatersuppliestoeachpoolcanprovidemake-upinsupportoftheRHRFPCmode.Additionally, ESWiscapableofsupplying make-upfortheboilingspentfuelpoolanalysisasdescribed inAppendix9A.

Reference:

PositionC.l.e.TheMainSteamSystem(MSS)beyondtheouterisolation valvesuptoandincluding theturbinestopvalvesandallbranchlines21/2in.indiameterandlarger,uptoandincluding thefirstvalve(including theirrestraints) arenotclassified SeismicCategoryI;becauseportionsofthepipeareroutedinanon-Seismic CategoryIbuilding(theTurbineBuilding).

However,theturbinebuildinghasbeendesignedtowithstand anSSEasstatedinSubsection 3.7b.2'.Furtherdescription oftheturbinebuildingisgiveninSubsection 3.8.4.1;applicable loadcombinations aregiveninTable3.8-10.Thesubjectpipingisdesignedinaccordance withASMESectionIII,Class2requirements fortheOBEandSSEasdescribed inSubsection 10.3.3.

Reference:

PositionC.l.h.Thecomponent coolingwaterportionsofthereactorrecirculation pumpsarenotSeismicClassIsincetheydonotinvolveasafetyfunction.

Reference:

Paragraph C.2oftheRegulatory Guide.Itemswhichwouldotherwise beclassified non-seismic categoryI,"butwhosefailurecouldreducethefunctioning" ofitemsimportant tosafety"toanunacceptable safetylevel"aretobe"designed andconstructed sothattheSSEwouldnotcausesuchfailure."

Inaddition, Paragraph C.4oftheguiderequiresthatthe"pertinent qualityassurance requirement ofAppendixBto10CFRPart50shouldbeappliedtothesafetyrequirements" ofsuchitems.Bothof'hesepositions areconsidered tobeadequately metbyapplyingthefollowing practices tosuchitems:06/933.13-10 SSES-FSAR (a)Designanddesigncontrolforsuchitemsarecarriedoutinthesamemannerasthatforitemsdirectlyimportant tosafety.Thisincludestheperformance ofappropriate designreviews.Rev.46,06/933.13-(11)

SSES-FSAR TABLE3.2-1Continued)

Page9.Principal Components (34*)FSARSectionSourceof~Su1(1)*Loca-tion(2)*QualityGroupClassi-fication(3)*SafetyClass(4)*Principal Construc-tionCodesandStandards (5)*SeismicCategonr(6)*QualityAssurance Reenirement Cmmmnte(7)**UnderReactorVesselServiceEuintEquipment handlingplatformCRDhandlingequipment FuelPoolCooli5CleanuSstemHeatexchangers PumpsSkimaersurgetanksFilterdemineralizer vesselsResinandprecoattanksCoolinglooppipingandvalvesdownstream ofvalve1-53-001.

2-53-001RHRintertiepipingandvalvesEmergency servicewatermakeuppipingandvalvesOtherpipingandvalvesCoolinlooipinustreamofvalvel-53-Ii0(.

2-5-II01fromskirmersurgetankRadioactive WasteManaementLiuidWasteNanaementSstemsCentrifugal pumpsAtmospheric Tanks9.1.49.1.311.2GEGER/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-FSAR TABLE3.2-1SSESDESIGNCRITERIASUMMARY(Continued)

Page5254)Thedieselgenerator jacketwatercoolers(OE507BandOE507D)utilizeanASMESectionVIIIreplacement tubebundleinaccordance withtheguidanceofNRCGenericLetter89-09.55)Thefollowing manuallyoperatedvalvesprovideafillablevolumeforuseoftheRHRFPCmode.Thefollowing manuallyoperatedvalves,whichareintheseismically analyzedsectionsofpipe,requireacapability tobeclosedfollowing aseismicevent.Thesevalveshavebeenanalyzedtodemonstrate thattheywillbecapableofclosurefollowing aseismicevent:SpentFuelPoolto153018A/B (253018A/B),

FuelPoolGateDrainto153038(253038),

andReactorWellDiffuserto153030A/B (25303OA/B).

Thefollowing manuallyoperatedvalves,whichareinseismically analyzedsectionsofpipe,haveapostseismiceventfunctiontoremainintheclosedposition:

ReactorWellDrainto153031(253031),

ReactorWellDrainto153032(253032),

ReactorWellDrainto153062(253062),

DryerSeparator PoolDrainto153040(253040),

DryerSeparator PoolDrainto153041(253041),

CaskPitGateDrainto153050(253050),

CaskPitDrainto153054(253054),

CaskPitDrainto053084&,253800,andCaskPitDiffuserto053025.56)Theportionsofpipingbetweenthesurgetankuptoandincluding valvesHV15308(25308),153076(253076),

and153064A/B (253064A/B)

'havebeenanalyzedtoshowthattheywillremainintactfollowing aseismicevent.Thesevalveshavebeenanalyzedtodemonstrate thattheywillbecapableofclosure(orremaining closed)following aseismicevent.Closureofthesevalvesisnecessary toprovideafillablevolumeforuseoftheRHRFPCmode.TheSkimmerSurgeTankdrainlinevalves,153065A(253065A),

arenormallyclosedandassumedtoremainclosedduringaseismicevent.Rev.47,06/94 SSES-FSAR thecapacityofasingleRHRheatexchanger andrelatedservicewatercapability.

Figure5.4-12showstheminimumtimerequiredtoreducevesselcoolanttemperature to212'FusingoneRHRheatexchanger andallowing2hoursforflushing.

5.4.7.1.1.2 LowPressureCoolantIn'ection LPCIModeThe,functional designbasesforthe,LPCImodeistopumpatotalof21,300gpmofwaterperloopusingtheseparatepumploopsfromthesuppression poolintothecoreregionofthevessel,whenthevesselpressureis20psidoverdrywellpressure.

Injection flowcommences at280psidvesselpressureabovedrywellpressure.

Theinitiating signalsare:vessellevel1.0feetabovetheactivecoreordrywellpressuregreaterthanorequalto1.69psigcoincident withalowreactorpressure.

Thepumpswillattainratedspeedin27secondsandinjection valvesfullyopenin40seconds'.4.7.1.1.3 SuressionPoolCoolinModeThefunctional designbasisforthesuppression poolcoolingmodeisthatitshallhavethecapacitytoensurethatthebulksuppression pooltemperature immediately afterablowdownshallnotexceed207'F.5.4.7.1.1.4 Containment SraCoolinModeThefunctional designbasisforthecontainment spraycoolingmodeisthatthereshouldbetworedundant meanstosprayintothedrywellandsuppression poolvaporspacetoreduceinternalpressuretobelowdesignlimits.5.4.7.1.1.5 ReactorSteamCondensin ModeThissectionhasbeenintentionally deleted.5.4.7.1.1.6 FuelPoolCoolinModeThefunctional designbasisforthefuelpoolcoolingmodeisasfollows:a)TheRHRFPCmodeisdesignedandoperatedtoprovidecoolingsuchthatthefuelpoolwillbemaintained atorbelow125FwhentheEmergency HeatLoad(EHL)isRev.46,06/935.4-33 SSES-FSAR residentinanisolatedfuelpool.TheEHLcanberemovedwithaRHRSWinlettemperature of91'FwithonlyoneRHRpumpandheatexchange.

Forcrosstied fuelpools,oneRHRpumpandheatexchanger inoneunitincombination withthenormalFuelPoolCoolingsystemfromtheadjacentunitissufficient tomaintainthefuelpoolsatorbelow125'FwiththeEHLresidentinonefuelpoolandfuelatthescheduled offloadrateintheotherfuelpool.Thisfunctionisdescribed inSections9.1.3.band9.1.3.2.b)TheRHRFPCmodeisdesignedandoperatedtoprovidesufficient coolingtopreventfuelpoolboilingintheeventthataseismiceventcausesanextendedlossofbothunits'ormal fuelpoolcoolingsystems.Thiscapability existsforbothcrosstied andisolatedfuelpools.WhenoneRHRpumpisoperatedintheRHRFPCmode,thespentfuelpoollevelmustberaisedtoaminimumlevelabovetheweirsinordertosupportthedesignflowrateforthismode.Additional detailsdescribing thismodeofRHRarecontained inSections5.4.7.2.6c, 9.1.3.1c, 9.1.3.2,and9.1.3.3.5.4.7.1.2 DesignBasisforIsolation ofRHRSystemfromReactorCoolantSstemThelowpressureportions, oftheRHRsystem,areisolatedfromfullreactorpressurewhenevertheprimarysystempressureisabovetheRHRsystemdesignpressure.

SeeSubsection 5.4.7.1.3 forfurtherdetails.Inaddition, automatic isolation mayoccurforreasonsofvesselwaterinventory retention whichisunrelated tolinepressurerates.(SeeSubsection 5.2.5foranexplanation oftheLeakDetection Systemandtheisolation signals.)

ReactorCoolantpressureboundaryvalvesaresubjecttoinservice inspection leakagetestingrequirements asprovidedin10CFR50.55a (seeSubsection 3.9.6).TheRHRpumpsareprotected againstdamagefromacloseddischarge valvebymeansofautomatic minimumflowvalves,whichopenonlowmainlineflowandcloseonhighmainlineflow.5.4.7.1.3 DesinBasisForPressureReliefCaacitThereliefvalvesintheRHRsystemaresizedononeofthreebases:(1)ThermalreliefonlyRev.46,06/935.4-34 SSES-FSAR (2)Valvebypassleakageonly(3)Controlvalvefailureandthesubsequent uncontrolled flowwhichresults.Transients aretreatedbyitems(1)and(3);item(2)abovehasresultedfromanexcessive leakpast'isolation valves.F055ARBshallbesizedtomaintainupstreampipingat450psigand10percentaccumulation withF051andF052fullyopenandareactorpressureequaltothelowestNuclearBoilersafety/relief valvespringsetpoint.F097shallbesizedtomaintainupstreampressureat180psigand10percentaccumulation withbothPCVF053A&Bfailedopen.F030A,B,C,andD,F025AandB,F029,F126,andF087shallbesetatthedesignpressurespecified intheprocessdatadrawingplus10percentaccumulation.

Redundant interlocks preventopeningvalvestothelowpressuresuctionpipingwhenthereactorpressureisabovetheshutdownrange.Thesesameinterlocks initiatevalveclosureonincreasing reactorpressure.

Inadditionahighpressurecheckvalvewillclosetopreventreverseflowfromthereactorifthepressureshouldincrease.

Reliefvalvesinthedischarge pipingaresizedtoaccountforleakagepastthecheckvalve.5.4.7.1.4 DesignBasisWithRespecttoGeneralDesinCriteria5TheRHRsystemforeachunitdoesnotshareequipment orstructures withtheothernuclearunitexceptfortheSpentFuelPoolsasdiscussed inSubsection 9.1.3.3.TheyalsosharethecommonEmergency ServiceWaterSystem.SharingofthissystemwithrespecttoGeneralDesignCriteria5isdiscussed inSection3.1.2.1.5.

Rev.46,06/935.4-(35)

SSES-FSAR performflushingwillcauseinjection ofnon-reactor gradewaterintothereactorpressurevesselbutwillnotaffectperformance oftheRHRshutdowncoolingsystem.Attheendofthisnominalflush,thetestablecheckbypassvalvemaybeopenedintheshutdownreturnlineandvesselwateris-permitted toentertheupperportion'.,of thechosenlooptoprewarmi'ffluent isdirectedtoradwasteandatemperature elementisusedtocontroleffluenttemperature.

Thetestablecheckbypassvalveisclosedandvesselsuctionvalvesareopenedtoallowprewarming ofthelowerhalfoftheshutdownloopwitheffluentdirectedtoradwasteasbefore.Theradwasteeffluentvalvesareclosed,theheatexchanger bypassvalvesopened(theexchanger valveswereclosedaftertheinitialcoldwaterflush),thenthepumpstartsataregulated flowthroughreturnvalveF017.Afterwaitingseveralminutestopermitloopinternalstability tobeestablished theservicewaterpumpisstarted,theservicewatervalvesareopened,theheatexchanger inletandoutletvalvesareopenedandcooldownofthevesselisinprogress.

Cooldownrateissubsequently controlled viavalvesF017(totalflow)andF048(heatexchanger bypassflow).Alloperations areperformed fromthecontrolroomexceptforopeningandclosingoflocalflushwatervalves.Themanualactionsrequiredforthemostlimitingfailurearediscussed inSubsection 5.4.7.1.5.

b.SteamCondensin C.Thissectionhasbeenintentionally deleted.FuelPoolCoolinModeOperation ofRHRinthefuelpoolcoolingmoderequiresmanualactionstobeperformed bothinthecontrolroomandlocally.Thesystemwillalsoberequiredtobefilledandvented,whichwillrequirethemanipulation ofvarioussmallmanualvalves.Thefillingoperation mayalsoincludeoperation oftheESWsystemintheeventthenormalfillsystemsareunavailable.

Theseactionsaredescribed inandcontrolled byplantprocedures.

5.4.7.3Performance Evaluation Thermalperformance oftheRHRheatexchangers isbasedontheresidualheatgenerated at20hoursafterrodinsertion, a125'Fvesseloutlet(exchanger inlet)temperature, andtheflowoftwoloopsinoperation.

Becauseshutdownisusuallyacontrolled operation, maximumservicewatertemperature lessRev.46,06/935.4-39 SSES-FSAR 10'Fisusedastheservicewaterinlettemperature.

Thesearenominaldesignconditions; iftheservicewatertemperature ishigher,theexchanger capabilities arereducedandtheshutdowntimemaybelongerandviceversa.5.4.7.3.1 ShutdownWithAllComonentsAvailable Notypicalcurveisincludedheretoshowvesselcooldowntemperatures versustimeduetotheinfinitevarietyofsuchcurvesthatmaybedueto:(1)cleansteamsystemsthatmayallowthemaincondenser tobeusedastheheatsinkwhennuclearRev.46,06/935.4-(40)

SSES-FSAR f)Theplateswillbewashedinamildabrasiveanddetergent

solution, thenrinsedincleanwaterand/oracetone.Theplateswillbedriedina175'Fovenfora4hours,followedby4hoursina300'Fovenand4additional hoursina500'Foven.Theplateweightwillbedetermined, atroomtemperature, following eachdryingi.'nterval.

Dryingmaybediscontinued whennofurtherweightlossoccurs.g)Eachplatewillbeweighedanddetermine weightchange.h)Reperform stepge.i)Alldatawillberecorded, including pHvalues,forfuturecomparison.

9.1.3SPENTFUELPOOLCOOLINQANDCLEANUPSYSTEM9.1.3.1DesinBasesTheFuelPoolCoolingandCleanupSystem(FPCCS)isdesignedandoperatedwiththefollowing considerations:

a)Maintaining thefuelpoolwatertemperature below125'F.TheheatloadwhichservedasthebasisfortheFPCCSdesignisbaseduponfillingthepoolwith2840fuelassemblies fromnormalrefueling discharges andtransferred tothefuelpoolwithin160hoursaftershutdown.

Tables9.1-2aand9.1-2bshowtheoriginally assumeddischarge scheduleandheatload.Table9.1-2eshowsanupdateddischarge schedule.

b)Duringanemergency heatload(EHL)condition, oneRHRpumpandheatexchanger areavailable forfuelpoolcooling.TheEHLcondition occurswhenthespentfuelracksofonespentfuelpoolcontain2850fuelassemblies including afullcoredischarged tothepoolwithin250hoursaftershutdown(controlrodsinserted).

Tables9.1-2cand9.1-2dshowthedischarge scheduleandheatloadthatwasassumedforthesystem'sdesignforthiscondition forUnits1and2.Table9.1-2fshowsanupdateddischarge schedule.

TheRHRFuelPoolCooling(RHRFPC)Modewillmaintaintheisolatedfuelpoolwatertemperature, (withtheheatloadof3.39x10'TU/hr) atorbelow125'Fwithorwithoutassistance fromtheFPCCSundernormalrefueling conditions.

WhenthedecayheatloadofthespentfueldropstothelevelforwhichtheFPCCSisdesigned, theRHRsystemmaybedisengaged.

Forcrosstied spentfuelpools,theRHRFPCmodeinoneunitincombination withthenormalFuelPoolCoolingSystemoftheotherunitwillmaintainthecrosstied fuelRev.48,12/949.1-21 SSES-FSAR poolsatorbelow125'FwiththeEHLinonepoolandfuelatthenormalscheduled offloadrateintheotherpool.c)Following aseismicevent,thenormalFuelPoolCoolingsystemispostulated tobeunavailable duetoitsNon-SeismicCategoryI,Non-Class 1Epowerdesign.IfsuchaneventweretooccurtheRHRFuelPoolCooling(RHRFPC)modewouldbeusedtoprovidecoolingtothespentfuelpoolstopreventboiling.Allpipingandcomponents oftheRHRFPCmodeareSeismicCategory1,QualityGroupBorCconstructed toASMESectionIIIstandards.

TheRHRsystemisClass1Epoweredandbothloopshaveseparatepowersupplies.

TheRHRFPCsystemishardpiped andrequiresoperation ofseveralmanualvalves.(whichareaccessible following aseismicevent)toestablish theflowpath.

Inaddition, othermanualandmotoroperatedvalvesmustbeoperatedinordertoassureproperoperation oftheRHRFPCmode.Properoperation ofallactivecomponents intheRHRFPCmodeisconfirmed onaperiodicbasisinaccordance withplantprocedures.

TheRHRpumpsuctionpathfortheFuelPoolCoolingmodeissharedwiththeShutdownCoolingmodeofRHR.Consequently, ShutdownCoolingandFuelPoolCoolingcannotbeperformed concurrently onagivenunit.However,Alternate ShutdownCoolingandFuelPoolCoolingcanbeperformed concurrently sincedifferent suctionsourcesareused.Appendix9Acontainsanevaluation ofaboilingspentfuelpoolforaNon-Seismic CategoryIFuelPoolCoolingsystem.Boilingofthespentfuelpool(s)wouldnotoccurduringaseismiceventduetouseoftheRHRFuelPoolCoolingsystemasabackupSeismicCategoryIFuelPoolCoolingsystem.TheRHRFPCmodecanbeplacedintoservicewellinadvanceofthepostulated timetoboilof25hours(seeSubsection 9.1.3.3).

d)Tomaintainthewaterclarityandqualityinthepoolsasfollowstofacilitate underwater handlingoffuelassemblies andtominimizefissionandcorrosion productbuildupthatposearadiological hazardtooperating personnel:

Conductivity pHChloride(asCl)3mircromho/cm at25'C5.3-7.5at25'C0.5ppmRev.48,12/949.1-22 SSES-FSAR Heavyelements(Fe,Cu,Hg,Ni) 0.1ppmTotalinsolubles 1ppm9.1.3.2SstemDescritionEachreactorunitisprovidedwithitsownFPCCSasshownonFigures9.1-7and9.1-8.Thesystemcoolsthefuelstoragepoolwaterbytransferring thedecayheatoftheirradiated fuelthroughheatexchangers totheservicewatersystem.Waterclarityandqualityinthefuelstoragepools,transfercanals,reactorwells,dryer-separator pools,andshippingcaskpitaremaintained byfiltering anddemineralizing.

TheFPCCSconsistsoffuelpoolcooling'umps, heatexchangers, skimmersurgetanks,filterdemineralizers, associated piping,valves,andinstrumentation.

EuimentDescritionTable9.1-1showsthedesignparameters oftheFPCCSequipment.

'heseismicandqualitygroupclassifications oftheFPCCScomponents arelistedinSection3.2.Oneskimmersurgetankforeachunitcollectsoverflowwaterfromskimmerdrainopeningswithadjustable weirsatthewatersurfaceelevation ofeachpoolandwell.Thecommonshippingcaskpitwateroverflows tobothunits'kimmer surgetanks.Wavesuppression scuppersalongtheworkingsideofthefuelpoolsalsodraintotheskimmersurgetanks.Theskimmeropeningsinthepoollinersareprotected withawiremeshscreentopreventfloatingobjectssuchasthesurfacebreakerviewingaidsfromenteringthesurgetanks.Theadjustable weirplatesaresetaccording totherequiredcoolingflow,desiredflowpattern,andwatershielding needs.Theskimmersurgetankprovidesasuctionheadforthefuelpoolcoolingpumpsandabuffervolumeduringtransient flowsinthenormallyclosedloopFPCCS.Itprovidessufficient livecapacityforthreedays'ormal evaporative lossfromthefuelpoolwithoutmakeupfromthecondensate transfersystem.Aremovable objectretention screeninthetankisaccessible throughtheflangedtanktop.Tanklevelindication andalarmsonacontrolpanelontherefueling floorand/orthevicinityofthefuelpoolcoolingpumpsannouncewhentheremotemanualmakeupvalvesmustbeopenedorwaterdrainedfromthesystem.Rev.46,06/939.1-23

)

SSES-FSAR ThefuelpoolcoolingpumpsarestoppeduponalowtanklevelsignalsThreefuelpoolheatexchangers pipedinparallelarelocatedinthereactorbuildingbelowthesurgetankbottomelevation.

Theshellsideissubjected tothestaticheadoftheskimmersurgetanklevelonly.Thisisaminimumof5psilowerthanthetubesideservicewaterpressure, thusminimizing thepossibility ofradioactive contamination oftheservicewatersystem(seeSubsection 9.2.1)fromatubeleak.Thenumberofheatexchangers inservicedependsonthedecayheatloadfromirradiated fuelinthespentfuelpool.Thecommoninletandeachheatexchanger outlettemperature arerecordedandhightemperature alarmedonalocalcontrolpanel.Threefuelpoolcoolingpumpspipedinparallelareplacedinserviceinconjunction withtheheatexchangers.

Theytakesuctionfromtheheatexchangers anddevelopsufficient headtoprocessapartialsystemflowthroughthefilterdemineralizers andtransferitcombinedwiththebypassflowtothediffuserpipesatthebottomofthepools.Thepumpcontrols, discharge pressureindicators, flowindicator, andalarmsforlowflowandlowdischarge pressureareprovidedonalocalcontrolpanel.Thepumpstripindividually uponlowNPSH.Threefuelpoolfilterdemineralizers arepipedinparallel.

Onefuelpoolfilterdemineralizer isnormallyassociated witheachFPCCSwiththethirdoneinstandby.Thedesignflowperfilterdemineralizer islessthanthetotalsystemflow.Partofthecooledwateristherefore bypassing atamanuallyadjustable rate.Rev.46,06/939.X-(24)

SSES-FSAR skimmersurgetanks'uring periodswhentheheatinthepoolisgreaterthanthecapacityofthefuelpoolcoolingsystem(suchthatacceptable fuelpooltemperatures cannotbemaintained),

eg,storingofafullcoreofirradiated fuelshortlyaftershutdown, theRHRsystemcanbeusedtodissipate thedecayheat.OneRHRpumptakessuctionfromanintertielinetotheskimmersurgetankanddischarges throughoneRHRheatexchanger totwoindependent diffusers atthefuelpoolbottom.Withthespentfuelpool(s)filledtoaheightapproximately 7.5inchesabovetheweirs,theskimmersurgetankprovidessufficient suctionheadtoanRHRpumpintheRHRFuelPoolCooling(RHRFPC)mode.Makeupwatertoreplenish evaporative andsmallleakagelossesfromthepoolsisprovidedfromthecondensate transferstoragetankintotheskimmersurgetankbyopeningaremotemanualvalve.ASeismicCategoryIlinefromeachofthetwoemergency servicewaterloopsisconnected totheRHRintertiediffuserlinesofeachfuelpool,allowingforemergency makeupinsupportofRHRFPCorduringpostulated boilingofthepoolwaterasdescribed inAppendix9A.Themanualsupplyvalvesintheseemergency makeuplinesareaccessible fromelevations belowtherefueling floor.9.1.3.3SafetEvaluation AtFPCCSdesignconditions wherethepoolheatloadis12.6MBTU/HRandservicewatertemperature is95'FtheFPCCSwillmaintainthefuelpoolwaterlessthan125'F.Atimprovedservicewatertemperature conditions, theFPCCScanmaintainthefuelpoolwaterlessthan125'Fwithlargerheatloadsinthepool.Thiscondition occursduringrefueling outages.Whenthiscondition existsthepoolismonitored toassureadequateFPCCScapacityexists.WhentheFPCCScannotmaintainthepooltemperature lessthan125'F,theRHRsystemintheFuelPoolCoolingMode(RHRFPC)canbeconnected tothepoolstomaintainpooltemperatures below125'FbytheRHRFPCmode.ATEHLconditions (33.9MBTU/HR),

RHRFPCcanmaintainthepooltemperature below125'Fwithspraypondwatertemperatures belowTechnical Specification limits.Poolconfiguration willbemaintained duringtheoutagesequencesothatthecalculated timetoboilisgreaterthan25hours.ASeismicCategoryImakeupisprovidedbya2in.linefromeachemergency servicewater(ESW)looptotheRHRfuelpooldiffusers, thusproviding redundant flowpathsfromareliableRev.46,06/939.1-27 SSES-FSAR sourceofwater.ThedesignmakeupratefromeachESWloopisbasedonreplenishing thepostulated boil-offfromtheMNHLineachfuelpoolfor30daysfollowing thelossoftheFPCCScapacity.

ThisprovidesacapacityfarinexcessofwhatwouldberequiredbytheRHRFPCmodeinresponsetoalossofnormalfuelpoolcoolingduetoaseismicevent.Allpipingandequipment sharedwithorconnecting totheRHRintertieloopareSeismicCategoryI,QualityGroupC,orequivalent, andcanbeisolatedfromanypipingassociated withthenon-Seismic CategoryIQualityGroupCfuelpoolcoolingsystem.DuetoitsNon-Seismic CategoryI,Non-Class lEpowerdesign,theconsequences ofaseismiceventarerequiredtobeanalyzedfortheFPCsystem.Inresponsetothisevent,theRHRFPCmodewillbeusedtopreventboilingfromoccurring; however,anon-mechanistic evaluation ofboilingofbothspentfuelpoolsiscontained inAppendix9Ainordertoconservatively boundtheradiological consequences.

Thespentfuelpoolsarenormallymaintained inacrosstied configuration duringdualunitoperation andrefueling outages.Thisassuresthatthetimetoboilfollowing alossofnormalfuelpoolcoolingisaminimumof25hours;however,inthisconfiguration thetimetoboilistypically muchgreaterthantheminimum25hours.The25hourtimetoboilminimumwouldonlybeapproached shortlyafteraunitisshutdownforrefueling.

Aftercompletion ofarefueling outage,whenbothunitsareatpower,thetimetoboilistypically ontheorderof50hours.Thecrosstied configuration allowsuseofeitherunit'ssystems(normalSFPCoolingorRHRFPC)tocoolthepools,thusproviding fuelpoolcoolingredundancy.

Crosstied spentfuelpoolsalsoprovideredundancy forthelevelinstrumentation inthecontrolroom.Thisinstrumentation isdesignedtooperatefollowing anOperating BasisEarthquake andunderboilingspentfuelpoolconditions andisexpectedtoremainfunctional.

Whilenotclassified asClass1Eequipment, theinstruments receivepowerfromindependent Class1EpowersuppliesthatareDieselGenerator backed.Shouldaseismiceventoccurduringdualunitpoweroperation withcrosstied pools,adequatereactorcorecoolingwillbeprovidedandspentfuelpoolboilingwillbeprevented.

OnlyoneloopofRHRisnecessary toprovidelongtermdecayheatremovalperreactorvessel.Similarly, onlyoneloopofRHRisnecessary toprovidelongtermdecayheatremovaltocrosstied spentfuelpools.Sinceeitherunit'sRHRsystemcanprovidecoolingtobothunitsspentfuelpoolswiththepoolscrosstied, afailureofoneloopofRHRinoneoftheunitswouldstillallowasufficient numberofloopstocoolbothRev.46,06/939.1-28 JI SSES-FSAR reactorsandthespentfuelpools.Inthiscase,theunitproviding spentfuelpoolcoolingwouldutilizeAlternate ShutdownCoolingforlong-term decayheatremovalfromthereactor.TheotherunitwouldutilizethenormalShutdownCoolingmode.Duringspecificplantevolutions, suchastransferoffuelintofuelcasks,thepoolswillnotbecrosstied.

Theseevolutions willbeprocedurally controlled toensurethatsufficient coolingsystemsareavailable giventheplantconfiguration atthetimeoftheevolution.

Anevaluation oftheimpactsofoperating theRHRFPCmodeontheUltimateHeatSink(UHS)wasperformed asaseparateevaluation oftheminimumheattransfercasediscussed inSubsections 9.2.7.3.1 and9.2.7.3.6.

Theresultsofthisevaluation indicatethatthespraypond(UHS)willbemaintained belowthedesignmaximumtemperature underworstcaseaccidentconditions.

Additional detailsonthedesignoftheRHRFPCmodeareprovidedinSections5.4.7.1.1.6, 5.4.7.2.6C, and9.1.3.1C.Provisions tominimizeandmonitorleakagefromthefuelpoolaredescribed inSubsection 9.1.2.3.Makeupforevaporative andsmallleakagelossesfromthefuelpoolisnormallysuppliedfromthecondensate transfersystemtotheskimmersurgetanksofeachunit.Theintermittent flowrateisapproximately 50gpmtoeachsurgetank.Thewaterlevelinthespentfuelstoragepoolismaintained ataheightwhichissufficient toprovideshielding forrequiredbuildingoccupancy.

Radioactive particulates removedfromthefuelpoolarecollected infilterdemineralizer unitsinshieldedcells.Forthesereasons,,the exposureofstationpersonnel toradiation fromthespentfuelpoolcoolingandcleanupsystemisnormallyminimal.Furtherdetailsofradiological considerations aredescribed inChapter12.Anevaluation oftheradiological effectofaboilingfuelpoolispresented inAppendix9A.9.1.3.4InsectionandTestinReuirements Nospecialtestsarerequiredbecauseatleastonepump,heatexchanger, andfilterdemineralizer arecontinuously inoperation whilefuelisstoredinthepool.Theremaining components areperiodically operatedtohandleincreased heatloadsduringrefueling.

Rev.46,06/939.1-(29)

SSES-FSAR Thepoollinerleakdetection drainvalvesareperiodically openedandtheleakrateestimated bythevolumetric method.Gasordyepressuretestingfrombehindthelinerplatemaybeperformed tolocatealinerplateleak.Routinevisualinspection ofthe-systemcomponents, instrumentation, andtroublealarmsisprovidedtoverifysystemoperability.

Components andpipingoftheFPCCSdesignedperASMEBoilerandPressureVesselCode,SectionIII,Class3arein-service inspected asdescribed inSection6.6.Thesystemwillbepreoperationally testedinaccordance withtherequirements ofChapter14.Rev.46,06/939.j.-(30)

SSES-FSAR switchgear andloadcenterroomcoolers,whicharenormallysuppliedbythecontrolstructure chilledwatersysteminUnit1orthedirectexpansion (DX)coolingsysteminUnit2)requiredduringnormalandemergency conditions necessary tosafelyshutdowntheplant.TheESWSisdesignedtotakewaterfromthespraypond(theultimateheatsink),pumpittothevariousheatexchangers andreturnittothespraypondbywayofanetworkofspraysthatdissipate theheattotheatmosphere, TheESWSisrequiredtosupplycoolingwaterto:a)TheRHRpumproomunitcoolerandthemotorbearingoilcoolerofeachRHRpumpduringallmodesofoperation oftheRHRsystem.b)Alltheheatexchangers associated withthefourdieselgenerators alignedtothesystemduringoperation andtestmodes,exceptforthegovernoroilcoolers.c)Theroomcoolersforthecorespray(CS)pumps,thehighpressurecoolantinjection (HPCI)pumps,andreactorcoreisolation cooling(RCIC)pumpsduringtheoperation ofthesesystems.d)Thecontrolstructure chiller,theUnit2emergency switchgear coolingcondensing unit,reactorbuildingclosedcoolingwater(RBCCW)heatexchangers, andtheturbinebuildingclosedcoolingwaterheatexchanger (TBCCW)duringemergency operation.

e)Thespentfuelpoolstoprovidemake-upforevaporative lossesduringoperation ofthenormalfuelpoolcoolingsystemorRHRFuelPoolCooling(RHRFPC)mode,aswellas,fillingthespentfuelpoolsinsupportofRHRFPC.TheESWSisalsocapableofsupplying make-upforpostulated boilingconditions asdescribed inAppendix9AforaSeismicEvent.TheESWSstartsautomatically withinapprox.40-100secondsafterthedieselgenerators receivetheirstartinitiation signal.TheESWScanalsobestartedmanuallyfromeitherthemaincontrolroomorfromoneofthetworemoteshutdownpanels.(i.e~,ESWloopAcanonlybestartedfromtheUnit2remoteshutdownpanelandESWloopBcanonlybestartedfromtheUnit1remoteshutdownpanel.)Rev.47,06/949.2-13

~o

~~~~~~SSES-FSAR Inordertoavoidhavingunacceptable voltagesduetotheRHRorCSpumpsstartingsimultaneously withtheESWpumps,theESWloadsequencetimerisreinitialized, butonlyiftheESWpumpshavenotstartedbeforetheRHRorCSpumps.TheESWSisdesignedtooperateduringanyofthefollowing conditions:

a)LossofoffsitepowerRev.47,06/949.2-(14) a~

~tI~~~SSES-FSAR TABLE9.2-3DEFINITION OFESWFLOWSFORUNITS1842Page1of2Component No.ofUsersPerLoopU1U2Min.Req'dESWFlowPerUser(GPM)Min.Req'd.ESWLoopFlowForDBAand1LoopFailedTypicalMin.ESWLoopF)owNon.Accident w/1LoopOperating andServiceWaterAvailable TypicalMin.'"ESWSafeShutdownFlow-2LoopsOperating andBothUnitsServiceWaterNotAvailable A(B)B(A)1)Standby'"

DieselGenerator HeatExchangers 4commontotal1210(A,B,C,D) 1254(E)'"

4840(4884)'"4840(4SS4)'"4840(4884)'"2)RHRPumpRoomUnitCoolers4003)RHRPumpMotorBearingOilCooler4)CoreSprayPumpRoomUnitCoolers1442414424144241445)HPCIPumpRoomUnitCoolers10202020206)RCICPumpRoomUnitCoolers10202020207)ControlStructure Chiller1commonperloop7407407408)Emergency Switchgear CoolingCondensing Unit7272729)RBCCWheatexchangeru'400 280010)TBCCWheatexchanger

"'4549011)MakeuptoFuelPools'"60120120TOTALLoopFlow(GPM)6380(6424)'"5448(5492)'"6380(6424)'"3898Rev.47,06/94 t~>.a.~-'

SSES-FSAR Page2of2TABLE9.2-3(Continued)

DEFINITION OFESWFLOWSFORUNITS1BE21)Ononelooponly.2)Valveinparenthesis iswithanythree(3)ofA,B,C5Dunitsinserviceinconjunction with"E"unit.3)TheDieselGenerator "E"flowrateshownonthistableisbasedonthecontinuous dutyratingofthedieselgenerator (5000kw)~4)BothloopsofESWarealignedtotheD/G's.Itispreferred thatonepumpperloopberunduringnormaloperations.

However,intheeventofaDBAandasinglefailureinESW,oneloopwillbeavailable tosupplythedesignflowtotheDieselGenerator.

5)Thiscolumnillustrates theESWsystemsabilitytosupplyDBAflowsinadditiontosupplying TBCCWandRBCCWwithbothloopsoperating.

Theactualflowratesineachloopwillvaryslightlybecauseofthecrosstieatthediesels(i.e.the"B"loopwillpasssomeflowtotheD/G's).I6)Themake-uprateshownhereisconservatively basedonanon-mechanistic boilingspentfuelpool(seeSubsection 9.1.3.1).

Theflowrateformake-upofevaporative lossesduringRHRFPCoperation wouldbesignificantly less.Rev.47,06/94 c>0)~~

SSES-FSAR whichisinthecontrolroom,andeachpumpchamberisprovidedwithalowlevelsubmergence switchwhichalarmsinthecontrolroom.9.2.5.6PieCrackLeakaeDetection LeakagefromtheESWScanbedetectedbyoneofseveralmethodsdepending onlocation.

LeakagefrompipingwithintheESSWPumphouse drainsintoapitwhichisequippedwithalevelswitchtoalarmonhighwater.Theyard.pipingfromtheESSWpumphouse tothepumpdischarge flowelementsiscontained inaguardpipewhichdrainsbacktotheESSWPumphouse andintothesamepitasdescribed above.Theremaining yardpipingislocatedinahightrafficareaandthepresenceofasignificant leakwillbevisuallyapparent.

Leakdetection withintheReactorBuildings, ControlStructure andDieselGenerator Buildings differsdepending onthelocation.

Seismically analyzedroomflooddetectors areusedinthelowestelevations, suchas,theRHR,CoreSpray,HPCI,RCICandTBCCWHeatExchanger rooms.Flooddetection fortheroomscontaining ESWlinessupplying theRBCCWheatexchangers, ControlStructure

Chillers, Unit2DxunitsandFuelPoolMakeupisnotfeasiblenordesirable, sincethelinesarelocatedinupperelevations oftheReactorBuildingandControlStructure.

Intheseareas,floordrainsroutetheleakagetoradwasteviaeithertheReactorBuildingorTurbineBuildingsumps.Theexcessive influentintotheradwastesystemwillalertoperators toapipeleak.9.2.6RHRSERVICEWATERSYSTEM9.2.6.1DesinBasesTheResidualHeatRemovalServiceWaterSystem(RHRSWS)hasasafetyrelatedfunctionandisanengineered safeguard systemdesignedtosupplycoolingwatertotheresidualheatremoval(RHR)heatexchangers ofbothunits.TheRHRSWSisdesignedtotakewaterfromthespraypond(theultimateheatsink),pumpitthroughtheRHRheatexchanger,and returnittothespraypondbywayofaspraynetworkthatdissipates theheattotheatmosphere.

TheRHRSWSisdesignedtoprovideareliablesourceofcoolingwaterforalloperating modesoftheRHRsystemincluding heatremovalunderpost-accident conditions, RHRFuelPoolCooling(RHRFPC)following aseismicevent,andalsotoprovidewatertofloodthereactorcoreortheprimarycontainment afteranaccident, shoulditbenecessary.

Rev.47,06/949.2-19 I~(~SSES-FSAR 9.2.7ULTIMATEHEATSINKTheultimateheatsinkhassafetyrelatedfunctions andprovidescoolingwaterforuseintheEngineered Safeguard ServiceWatersystem,described inSubsections 9.2.5and9.2.6,duringESSWtesting,normalshutdown, andaccidentconditions.

9.2.7.1DesinBasesTheultimateheatsinkiscapableofproviding sufficient coolingwaterwithoutmakeuptothespraypondforatleast30daysto(a)permitsimultaneous safeshutdownandcooldownofbothnuclearreactorunitsandmaintaintheminasafeshutdowncondition, (b)mitigatetheeffectsofanaccidentinoneunit,permitsafecontrolandcooldownoftheotherunit,andmaintainitinasafeshutdowncondition or(c)permitsimultaneous safeshutdownandcooldownofbothunitsandmaintaintheminsafeshutdownwhileproviding adequatecoolingtobothspentfuelpoolsfollowing aseismicevent.Continued coolingbeyond30daysisensuredbyuseofthemakeuppumpstokeepthepondatnormalwaterlevel.ThemakeuppumpsaredesignedtooperatebelowthehistoricminimumwaterleveloftheSusquehanna River.Intheeventthatmakeupwaterfromthemakeuppumpsisnotavailable, additional provisions willbemadeinthe30daysavailable toassurecontinued coolingoftheemergency equipment beyond30days.Theseprovisions includebutarenotlimitedto:re-establishing makeuppumpflowtothespraypond,emptyingthecoolingtowerbasinsintothespraypond,truckinginwaterfromneighboring watersources(suchastheSusquehanna River),andproviding temporary pumpsand/orlinestopumpwaterfromneighboring watersources(suchastheSusquehanna River,onsitestoragetanks,wellwater,etc.)'.Thisisincompliance withNRCRegulatory Guide1.27Rev.2asdiscussed inSection3.13.Theultimateheatsinkisalsocapableofproviding enoughcoolingwaterwithoutmakeup,foradesignbasisLOCAinoneunitwiththesimultaneous shutdownoftheotherunit,for30dayswhileassumingaconcurrent SSE,singlefailure,and.lossofoffsitepower.Thiseventisevaluated inSubsection 9.2.7.3.1.

Theultimateheatsinkconsistsofatleastonehighlyreliablewatersourcewithacapability toperformthesafetyfunctionrequiredaboveduringandafteranyoneofthefollowing postulated designbasisevents:a)Themostseverenaturalphenomena, including thesafeshutdownearthquake, tornado,flood,ordroughttakenindividually Rev.47,06/949.2-25

~~~

SSES-FSAR Page1of1TABLE9.2-8SUSQUEHANNA PONDWATERALLOWANCES LossDescription WaterAllowance (x10'al)a)Evaporation duetoheatdissipation dutyformaximumwaterlosscase7.95b)Driftfromwindformaximumwaterlosscase1.15c)Percolation throughthepondlining0.3d)SystemchargingvolumeNegligible e)Maximumsolarevaporation losses1.85f)Lossesresulting fromwaveactionul0g)Lossesresulting fromsedimentation'"

1.0h)Fuelpoolmakeup'"5.0i)Acontingency forwaterqualityconsiderations 2.7TotalPondVolumeRequired19.95TotalPondVolumeProvided25.0Basedondesignprovisions forprotection fromthisloss.(2)Negligible sedimentation isanticipated.

Thevaluegivencorresponds to6in.ofponddepth,whichisaconservative allowance betweencleaningperiods.(3)Foradditional conservatism, thisvalueassumesboilingofthefuelpoolsconsistent withthenon-mechanistic boilingpoolanalysisinAppendix9A.Rev.35,07/84 SSES-FSAR APPENDIX9AANALYSISFORNONSEISMICSPENTFUELPOOLCOOLINGSYSTEMSAsdescribed inSubsection 9.1.3theSpentFuelPool(SFP)CoolingSystemsaredesignedasnon-sei'smic CategoryI,QualityGroupCsystems.Consequently, theradiological consequences ofalossofspentfuelpoolcoolingduetoaseismiceventareevaluated.

Inordertoperformthisanalysisitisnecessary toassumetheSFPwillboileventhoughSection9.1.3.3establishes thatthedesignbasisoftheplantforthiseventistopreventboilingthroughtheuseoftheRHRFPCmode.Sincethecoolingsystemsforbothunitsarecross-connected andincloseproximity itwasassumedthataseismiceventcausesthelossofcoolingtobothspentfuelpools.Inaddition, inordertomaximizeboth'heheatloadsandtheiodineinventories inthepools,refuelings within135dayswerepostulated.

(Periodoftimebetweenoutagesisnominally 180days,thususeof135daysisconservative.)

Thelossofcoolingwasassumedduringthesecondrefueling, justafterisolation ofthepools(i.e.,refueling andcaskpitgatesinstalled).

TheRHRsystemisassumedtonotbeavailable forcoolingtheSFPeventhoughitwouldbeabletoprovidecoolinginresponsetothisevent.Thus,itisassumedthatthepoolswillboil.Theanalysisinvolvedanevaluation ofthetimetopoolboiling,theabilitytomaintainwaterlevelifthepoolboils,andthethyroiddoseconsequences attheLPZboundaryduetoiodinereleasesfromtheboilingpools.Theassumptions usedinthisanalysiswereconsistently chosentobeconservative andboundingsimilartothoseinRegulatory Guidesfordesignbasisaccidents (e.g.,Regulatory Guides1.3,1.25,etc.).Thecombination ofallofthesedesignbasisassumptions occurring atthesametimewouldbeextremely

unlikely, makingthisaccidentasanalyzed, oneofverylowprobability.

Manyoftheassumptions areconsidered tobeoverlyconservative.

Forexample,operating experience withpresentBWRfuels(Reference 9A-1)indicates thattheassumption of700pCi/sec(fullpowerdesignbasisleakagerate)isconservative fordetermining reactorcoolantconcentrations duringoperating conditions.

ThissameleakageratewillbeassumedforthefuelintheSFP,whichisevenmoreconservative.

Eventhoughspikingfactorshaveyettobeobservedforatemperature riseinSFPs,spikingfactorshavebeenutilized.

Amorerealistic evaluation ofthisaccidentwouldresultinreleasesofradioactivity, ifany,manyordersofmagnitude belowthecalculated values.Therealistic releaseswouldbewellbelowthe10CFR50AppendixIrelatedTechnical Specifications, indicating thatsuchanincidentisoflittleornoconsequence.

Rev.46,06/939A-1 SSES-FSAR Thepoolswillbeoperatedinamannerwhichwillensurethattheywillnotboiluntilatleast25hoursafterthelossofcooling.Sincecoolingisassumednottoberestoredbeforethepoolboils,makeupwaterfromtheCategoryIEmergency ServiceWaterSystemisassumedtobeaddedtothepoolatarateequaltotheboilofftokeepthefuelcoveredwith23feetofwateratalltimes.AsshowninTable9A-1,thethyroiddoseconsequences oftheboilingpool,withoutoperation oftheStandbyGasTreatment System,arewellbelowtheguideline valuesof10CFR100andthe1.5REMthyroidguideline ofRegulatory Guide1.29.Thefollowing assumptions wereusedtocalculate theheatgeneration andboilingrate.l.Eachfuelpoolisfullwith2850fuelassemblies.

Themaximumexpecteddischarge batchsizeof280assemblies wasusedforthemostrecentoffloadineachpool.Theearlieroffloadswerebasedon256assemblybatchsizes.Todetermine theheatloadandthusboilingevaporation rate,sequential refuelings 129daysapartareassumed.Theeventisassumedtooccur6daysafterthesecondunitis,shutdown.

Sixdaysisconservatively chosenastheminimumtimetounload280assemblies andreinstall thefuelpoolgates(thusisolating thepool).Therefore, oneunit'sfuelpoolinventory isassumedtohavedecayedfor6days.Actualsequential refuelings occurapproximately 180daysapart.Thenormaltimetodefuel280assemblies is8days.Theseassumptions maximizetheheatloadintherecentlydefueledpoolandthustheboilingevaporation rate.Theanalyseswereperformed forpoweruprateconditions.

2.Thedecayheatwascalculated usingtheANSI/ANS-5.1-1979 decayheatstandard.

Thisstandardincludesmethodology forcalculating thedecayuncertainty.

Allvaluesofthedecayheatinthissectionareequaltothenominalvalueplustwostandarddeviations.

3.Todetermine aconservative boilingevaporation rateforpurposesofthisradiological evaluation, allheatgenerated bythefuelisassumedtobeabsorbedbythewaterinordertominimizethetimetoboiling.Noheatislosttothesurroundings byconduction throughtheconcreteandsteel,orbyevaporation.

Thetemperature gradients fromthefuelatthebottomofthepooltothecoolerwateratthetopwillcreateconvective waterandheatcurrentswhichwillthoroughly mixthewater,andpromoteanevendistribution ofheatratherthanlocalized pointsofsurfaceboiling.Rev.46,06/939A-2 SSES-FSAR 4.Theactivityreleaseratefromthepooldependsontheevaporation rateandtheiodinecarryover fractionatthepoolsurface.Theevaporation ratepriortoboilingisboundedbytheevaporation rateatinitiation ofboiling.Itisconservatively assumedthattheevaporation ratepriortoboilingisthesameasthatduringboiling.Rev.46,06/93 rQl0$~'l'.'