ML17157A338
| ML17157A338 | |
| Person / Time | |
|---|---|
| Site: | Susquehanna  |
| Issue date: | 09/30/1990 |
| From: | EMMETT J H PENNSYLVANIA POWER & LIGHT CO. |
| To: | |
| Shared Package | |
| ML17157A336 | List: |
| References | |
| PL-NF-90-005, PL-NF-90-5, NUDOCS 9010010145 | |
| Download: ML17157A338 (51) | |
Text
PL-NF-90-005SusquehannaSESUnit2Cycle5RELOADSUMMARYREPORTNuclearFuelsEngineering~~~September1990PennsylvaniaPower&.LightCompany90100i0145900924=PDRAGOCK050003SSPPDC
SUSQUEHANNASESUnit2Cycle5RELOADSUMMARYREPORTPreparedby:.H.Emmett/SSESUnit2GroupLeader-NuclearFuelsEngineeringc.ZC.R.Lehmann/SeniorScientist-ConsultingNuclearFuelsEngineeringA.J.oscioli/SeniorProjectEngineer-Nuclear'uelsEngineeringConcurwith:+gR.McKeon/upervisor-NuclearFuelsEngineeringApprovedby:J..tfako/Manager-clearFls&SystemsEngineeringPENNSYLVANIAPOWER&LIGHTCOMPANY
~,0W NOTICEThistechnicalreportwasderivedfrominformationdevelopedduringPPLL'snucleardesignandlicensinganalysisactivitiesandfromsafetyandlicensinginformationprovidedtoPPLLbyAdvancedNuclearFuelsCorporation.ThisreportisbeingsubmittedbyPPELtotheU.S.NuclearRegulatoryCommissionspecificallyinsupportoftheSusquehannaSteamElectricStationUnit2Cycle5reloadlicenseamendment.IndemonstratingcompliancewiththeU.S.NuclearRegulatoryCommission'sregulations,theinformationcontainedhereinistrueandcorrecttothebestofPP8L'sknowledge,information,andbelief.
I TABLEOFCONTENTSPa<acINTRODUCTION.1.02.03.04.05.06.07.0GENERALDESCRIPTIONOFRELOADSUBMITTALSCOPESSESUNIT2CYCLE4COREOPERATINGHISTORY.RELOADCOREDESCRIPTION.CONTROLBLADES.FUELMECHANICALDESIGN.THERMALHYDRAULICDESIGN.7.1HydraulicCompatibility.....7.2MCPRSafetyLimitTypeAnalyses.7.3CoreBypassFlow........7.4CoreStability.NUCLEARDESIGN.8.08.1FuelBundleNuclearDesign8.2CoreReactivity.8.3ContrastofCycle5CorewithCycle4.8.4NewFuelStorageVault/SpentFuelPool8.4.1NewFuelStorageVault.8.4.2SpentFuelPool........COREMONITORINGSYSTEM.9.0ANTICIPATEDOPERATIONALOCCURRENCES.10.1Core-WideTransients.........10.2LocalTransients.10.3ASMEOverpressurizationAnalysis..'.POSTULATEDACCIDENTS.11.1Loss-of-CoolantAccident.11.2ControlRodDropAccident.......11.3FuelandEquipmentHandlingAccidents.SINGLELOOPOPERATION.10.011.0
12.0REFERENCES
.~~~Criticality.~~~~1234591010111212141415161717181819202121222223242527
'~FiereTitleLISTOFFIGURES~PaeSSESUnit2,Cycle5CoreLoadingPattern..U2C5ANF-43.54wt%U235LatticeEnrichmentDistribution3132
LISTOFTABLESTitleUnit2Cycle5HCPRSafetyLimitTypeAnalysesNominalSSESOperatingConditions.U2C5CalculatedHCPROperatingLimits-GeneratorLoadRejectionw/oBypass..U2C5CalculatedHCPROperatingLimits-FeedwaterControllerFailureU2C5CalculatedHCPROperatingLimits-RecirculationFlowControllerFailure.U2C5CalculatedHCPROperatingLimits-LocalTransientsUnit2Cycle5LOCAHeatupResultsFuelandEquipmentHandlingAccidentResultsPa<ac33353637383940 I
INTRODUCTIONDuringCycle5operation,SusquehannaSteamElectricStation(SSES)Unit2willcontainthefourthreloadofAdvancedNuclearFuelsCorporation9x9fuelinSSESUnit2andthesecondfuelandcorenucleardesigndevelopedbyPP8LforUnit2.This-reportprovidesageneraldiscussionandsummaryoftheresultsofthereloadanalysesperformedbyPP&LandAdvancedNuclearFuelsCorporation(ANF)insupportofSSESUnit2Cycle5(U2C5)operation.PP&Ldevelopedthefuelandcorenucleardesignandperformedrelatedanalyses(e.g.,ShutdownMargin,HotExcessReactivity,andcyclelengthdetermination).PP&Lalsoperformedmostofthelicensinganalysesusingmethodsdescribed,benchmarked,anddemonstratedinReferences'1,2,and3.ThelicensinganalysesthatPP&Lperformedare:ShutdownMargin;StandbyLiquidControlSystemcapability;ControlRodDropAccident;LossofFeedwaterHeating;RodWithdrawalError;FuelLoadingError(bothRotatedandMislocated);GeneratorLoadRejectionwithoutBypass;FeedwaterControllerFailure;RecirculationFlowControllerFailure;and,ASMEOverpressurecompliance.ANFprovidedresultsfortheU2C5stability,LOCA,MCPRSafetyLimittypeanalyses,FuelStorageCriticality,SingleLoopOperationandFuelandEquipmentHandlingAccidents.ThePP&Lanalyses,evaluations,andresultspresentedinthisreportaresimilartothosesubmittedinReference3.TheANFanalyses,evaluations,andresultspresentedinthisreportandthereportsreferencedhereinaresimilartothosesubmittedinsupportofbothSSESUnit2Cycle4operation(Reference4)whichwereapprovedbytheNRC(Reference5)andSSESUnit1Cycle6operation(Reference7).AlsoincludedareadescriptionoftheU2C5reloadfuelandcoredesign,adescriptionanddiscussionofcontrolbladereplacementsforU2C5,andabriefdiscussionofthelicenseamendment(i.e.,proposedTechnicalSpecificationchanges).Theissue'fcorestabilityhasbeenaddressedforU2C5throughseveralcalculations,previousstartuptests(Section7.4ofthisreport),andimplementationoftheinterimoperatingguidelinespresentedinNRC Bulletin88-07Supplement1viaTechnicalSpecifications.ThisapproachisconsistentwiththecurrentUnit2Cycle4methodforaddressingcorestabi.lity.PP&LwillevaluatelongtermsolutionsdevelopedbytheBWROwner'sGroupStabilityCommitteewhentheyarecomplete.ThisU2C5ReloadSummaryReportalongwiththeproposedchangestotheSSESTechnicalSpecificationsserveasthebasicframeworkforthereloadlicensingsubmittal.Whereappropriate,referenceismadetoapplicablesupportingdocumentscontainingmoredetailedinformationand/orspecificsoftheapplicableanalysis.TheanalysesperformedbyANF,aslistedabove,weregeneratedincompliancewithANFtopicalreportXN-NF-80-19(P)(A),Vol.4Rev.1,"ApplicationofENCMethodologytoBWRReloads"(Reference6).Reference6describesinmoredetailtheanalysesperformedinsupportofthereloadandidentifiesthemethodologyusedforthoseanalyses.Thelistofreferencesprovidedattheendofthisdocumentcontainsthespecificreloaddocumentsa'ndtheapplicablegenericreloaddocuments(methodologypreviouslyapprovedorcurrentlyunderreview)whicharebeingusedinsupportoftheU2C5reloadcoresubmittal.2.0GENERALDESCRIPTIONOFRELOADSUBMITTALSCOPEDuringthefourthrefuelingandinspectionoutageatSSESUnit2,PP&Lwillreplace232irradiatedANF9x9fuelassemblies(approximately30percentofthepreviousCycle4core)with232freshANF-49x9fuelassemblies.TheANF-49x9fuelhassimilaroperatingcharacteristics(thermal-hydraulicandnuclear)totheANF-39x9designwhichwaspreviouslyapproved(Reference5).TheCycle5reloadcorerequiredtheperformanceofawiderangeofanalysestosupportU2CScoreoperation.Theseincludedanalysesforanticipatedoperationaloccurrencesandpostulatedaccidents.Inaddition,thegenericPumpSeizureAccidentanalysissubmittedforSSESUnit1Cycle6(Reference7)isbeingusedtosupportSingleLoopOperation(SLO)forUnit2Cycle5.Analysesfornormaloperationofthereactorconsistedoffuelevaluationsintheareasofmechanical,thermal-hydraulic,andnucleardesign.
BasedonPP&L'sdesignandanalysesandANF'sanalysesoftheCycle5reloadcore,anumberofproposedchangestotheSSESUnit2TechnicalSpecificationshaveresulted.ProposedchangesalsoexisttoincorporatePP&L'sReloadLicensingAnalysismethodology(Reference3).Therationaleusedtoarriveattheseproposedchangesiscontainedinthisdocument.AlistofthoseTechnicalSpecifications,applicableBases,andDesignFeaturesPP&Lproposestochangeisgivenbelow:ProosedChanestoTechnicalSecifications2.1-SafetyLimits3/4.2.3-MinimumCriticalPowerRatio3/4.4.1-RecirculationSystemProosedChan'stoTechnicalSecificationBases2.13/4.1.33/4.1.43/4.2.33/4.4.1-SafetyLimits-ControlRods-ControlRodProgramControls-MinimumCriticalPowerRatio-RecirculationSystemProosedChanestoDesinFeatures5.3-ReactorCore3.0SSESUNIT2CYCLE4COREOPERATINGHISTORYTodate,theCycle4corehasoperatedwithpowerdistributionsthatwillyieldend-of-cyclepowerandexposureshapesconsistentwiththeplannedoperatingstrategy.Actualcorefollowoperatingdataatthetimeofthereloadcoredesignanalysiswasused,togetherwithprojectedplantoperation,asabasisfortheCycle5coredesignandasinputtothe reloadlicensinganalyses.TheCycle4coreisexpectedtooperate,withintheassumptionsoftheCycle5reloadlicensinganalyses;therefore,theremainderofCycle4coreoperationwillnotaffectthelicensingbasisoftheCycle5reloadcore.IfCycle4doesnotoperatewithintheassumptionsoftheCycle5reloadlicensinganalyses,theeffectsonthereloadlicensinganalyseswillbeevaluated.4.0RELOADCOREDESCRIPTIONTheU2C5coredesignedbyPP&Lwillconsistof764fuelassemblies,including232freshANF9x9assemblies(ANF-4),204onceburnedANF9x9assemblies(ANF-3),236twiceburnedANF9x9assemblies(XN-2),and92XN-19x9assemblies.Ofthe92XN-19x9assemblies,85arethriceburned,6aretwiceburned,andoneisarepairedtwiceburnedassembly.TherepairedassemblywasdescribedinReference4,forU2C4operationandU2C4operationwasapprovedbyReference5.Thesixtwiceburnedassembliesmissedonecycleofirradiationbecausetheyweresymmetrictofailedfuelassemblies.TherepairedfuelassemblyfailedduringU2C2.ThefailedassemblywasrepairedduringU2C3,andtherepairedassemblyanditsthreesymmetricassemblieswerereturnedtouseinU2C4.AdifferentfuelassemblyfailedduringU2C3,andafterinspectionPP&Ldecidednottoreuseit;howeveritsthreesymmetricassembliesarebeingreturnedforuseduringU2C5.TheANF-4reloadfuelconsistsof232bundleswhichcontainnineburnablepoisonrodswith5.0wt%Gd~0~(9Gd5)atabundleaverageenrichmentof3.43wt%U-235.Abreakdownbybundletype/bundleaverageenrichmentisprovidedinthefollowingtable:NumberofBundlesBundleTe2321001041409685ANF9x9/3.43wt%ANF9x9/3.17wt%ANF9x9/3.33wt%ANF9x9/3.33wt%ANF9x9/3.33wt%ANF9x9/3.31wt%U235freshANF-4(9Gd5)U235onceburnedANF-3(9Gd4)U235onceburnedANF-3(9Gd5)U235twiceburnedXN-2(9Gd4)U235twiceburnedXN-2(10Gd5)U235thriceburnedXN-1(7Gd4)
ANF9x9/3.31wt%U235twiceburnedXN-1(7Gd4)ANF9x9/3.31wt%U235repairedtwiceburnedXN-1(7Gd4)raintson5.0CONTROLBLADESTheanticipatedCycle5coreloadingconfigurationalongwithadditionalcoredesigndetailsispresentedinFigure1.Thecoreisaconventionalscatterloadingwiththelowestreactivitybundlesplacedintheperipheralregionofthecore.AminorasymmetryexistsontheperipheryofthecorewherethreeofthetwiceburnedXN-1assembliesareloadedquartercoresymmetricallywithathriceburnedXN-1assembly.ThisisduetoPP&L'sdecisionnottoreuseafuelassemblythatfailedduringU2C3.PP&Lanalyzedthisasymmetryanddeterminedthatnosignificanteffectwouldresultonthesafetyanalyses,coreoperation,orcoremonitoringwhicharebased.onquartercoresymmetriccalculations.Inaddition,threeothertwiceburnedXN-1assembliesareloadedsymmetricallywiththerepairedtwiceburnedXN-1assembly.Theloadingpatternwasdesignedtoobtaintherequiredenergywhilemeetingtheconstshutdownmargin,hotexcessreactivity,andpowerpeaking.InresponsetoIEBulletin79-26,Rev.1,PP&Lcommittedtoreplacingcontrolbladespriortoexceedingalimitof34percentB"depletionaveragedovertheupperone-fourthofthecontrolblade(Reference8).ToensurethatthislimitisnotexceededduringSusquehannaSESUnit2Cycle5operationaswellasforotheroperationalobjectives,PP&Lplanstoreplaceupto50oftheoriginalequipmentcontrolbladesbeforeU2C5operation.TheoriginalequipmentcontrolbladeswillbereplacedwithGEDuralife160Ccontrolblades.TheDuralife160CcontrolbladeisdesignedtoeliminatetheB~Ctubecrackingproblemandincreasethecontrolbladeassemblylife.ThemaindifferencesbetweentheDuralife160Ccontrolbladesandtheoriginalequipmentcontrolbladesare:
a)theDuralife160CcontrolbladesutilizethreesolidhafniumrodsateachedgeofthecruciformtoreplacethethreeB<Crodsthataremostsusceptibletocrackingand,toincreasecontrolbladelife;,b)theDuralife160CcontrolbladesutilizeimprovedB~Ctubematerial(i.e.highpuritystainlesssteelvs.commercialpuritystainlesssteel)toeliminatecrackingintheremainingB~Crodsduringthelifetimeofthecontrolblade;c)theDuralife160CcontrolbladesutilizeGE'screvice-freestructuredesign,whichincludesadditionalBCtubesinplaceofthestiffeners,anincreasedsheaththickness,afulllengthweldtoattachthehandleandvelocitylimiter,andadditionalcoolantholesatthetopandbottomofthesheath;d)theDuralife160Ccontrolbladesutilizelowcobalt-bearingpinandrollermaterialsinplaceofstellitewhichwaspreviouslyutilized;e)theDuralife160Ccontrolbladehandlesarelongerbyapproximately3.1inchesinordertofacilitatefuelmoveswithinthereactorvesselduringrefuelingoutagesatSusquehannaSES;andf)theDuralife160Ccontrolbladesareapproximately16poundsheavierasaresultofthedesignchangesdescribedabove.TheDuralife160Ccontrolbladehasbeenevaluatedtoassureithas.adequatestructuralmarginunderloadingduetohandling,andnormal,emergency,andfaultedoperatingmodes.Theloadsevaluatedincludethoseduetonormaloperatingtransients(scramandjogging),pressuredifferentials,thermalgradients,seismicdeflection,irradiationgrowth,andallotherlateralandverticalloadsexpectedforeachcondition.TheDuralife160Ccontrolbladestresses,strains,andcumulativefatiguehavebeenevaluatedandresultinanacceptablemargintosafety.Thecontrolbladeinsertioncapabilityhasbeenevaluatedandfoundtobeacceptableduringallmodesofplantoperationwithinthelimitsofplant analyses.TheDuralife160Ccontrolbladecouplingmechanismisequivalenttotheoriginalequipmentcouplingmechanism,andisthereforefullycompatiblewiththeexistingcontrolroddrivesintheplant.Inaddition,thematerialsusedintheDuralife160Care'compatiblewiththe.reactorenvironment.Theimpactoftheincreasedweightofthecontrolbladesontheseismicandhydrody'namicloadevaluationofthereactorvesselandinternalshasbeenevaluatedandfoundtobenegligible.Withtheexceptionofthecrevice-,freestructureandtheextendedhandle,theDuralife160Ccontrol,bladesare.equivalenttotheNRCapprovedHybridIControlBladeAssembly(Reference9).Themechanicalaspectsofthecrevice-freestructurewereapprovedbytheNRCforallcontrolbladedesignsinReference10.Aneutronicsevaluationofthecrevice-freestructurefortheDuralife.160CdesignwasperformedbyGEusingthesamemethodologyaswasused,fortheHybridIcontrolbladesinReference9.ThesecalculationswereperformedfortheoriginalequipmentcontrolbladesandtheDuralife160CcontrolbladesdescribedaboveassuminganinfinitearrayofANF9x9fuel.TheDuralife160Ccontrolbladehasaslightlyhigherworththantheoriginalequipmentdesign,buttheincreaseinworthiswithinthecriterionfornuclearinterchangeability.TheincreaseinbladeworthhasbeentakenintoaccountintheappropriateU2C5analyses.However,asstated,inReference9,thecurrentpracticeinthelatticephysicsmethodsistomodeltheoriginalequipmentallB~Ccontrolbladeasnon-depleted.Theeffectsofcontrolbladedepletiononcoreneutronicsduringacyclearesmallandareinherentlytakenintoaccountbythegenerationofatargetk-effectiveforeachcycle.Asdiscussedabove,theneutronicscalculationsofthecrevice-freestructureshowthatthenon-depletedDuralife160Ccontrolbladehasdirectnuclearinterchangeabilitywiththenon-depletedoriginalequipmentallB~Cdesign.TheDuralife160Calsohasthesameend-of-lifereactivityworthreductionlimitastheallBCdesign.Therefore,theDuralife160CcanbeusedwithoutchangingthecurrentlatticephysicsmodelsaspreviouslyapprovedfortheHybridIcontrolblades(Reference9).
Theextendedhandleandthecrevice-freestructurefeaturesoftheDuralife160CcontrolbladesresultinaonepoundincreaseinthecontrolbladeweightoverthatoftheHybridIblades,andasixteenpoundincreaseovertheSusquehannaSESoriginalequipmentcontrolblades.InReference9,theNRCapprovedtheHybridIcontrolbladewhichweighsless(bymorethanonepound)thantheDlatticecontrolblade.ThebasisoftheControlRodDropAccidentanalysiscontinuestobeconservativewithrespecttocontrolroddropspeedsincetheDuralife160CcontrolbladeweighslessthantheDlatticecontrolblade,andtheheavierDlatticecontrolbladespeedisusedintheanalysis.Inaddition,GEperformedscramtimeanalysesanddeterminedthattheDuralife160Ccontrolbladescramtimesarenotsignificantlydifferentthantheoriginalequipmentcontrolbladescramtimes.ThecurrentSusquehannaSESmeasuredscramtimesalsohaveconsiderablemargintotheTechnicalSpecificationlimits.SincetheincreaseinweightoftheDuralife160Ccontrolbladesdoesnotsignificantlyincreasethemeasuredscramspeedsandthesafetyanalyseswhichinvolvereactorscramsutilizee'ithertheTechnicalSpecificationlimitscramtimesorarangeofscramtimesuptoaridincludingtheTechnicalSpecificationscramtimes,theoperatinglimitsareapplicabletoU2C5withDuralife160Ccontrolblades.SincetheDuralife160CcontrolbladescontainsolidhafniumrodsinlocationswheretheBCtubeshavefailed,andtheremainingB~Crodsaremanufacturedwithanimprovedtubingmaterial(highpuritystainlesssteelvs.commercialpuritystainlesssteel),boronlossduetocrackingisnotexpected.Therefore,therequirementsofIEBulletin79-26,Revision1donotapplytotheDuralife160Ccontrolblades.However,PP8Lplanstocontinuetrackingthedepletionofeachcontrolbladeanddischargeanycontrolbladepriortoatenpercentlossinreactivityworth.
6.0FUELMECKANICALDESIGNThemechanicaldesignandsupportinganalysesoftheU2C5ANF-4fuelarethesameasthosefortheSSESUnit2Cycle4ANF-3fuelandaredescribedinXN-NF-85-67(P)(A),Revision1(Reference11),XN-NF-84-97(Reference12),PLA-2728(Reference13),XN-NF-82-06(P)(A),Supplement1,Revision2(Reference14).EachANF-4reloadfuelassemblycontains79fueledrodsandtwowaterrodsina9x9rodarray.Oneofthewaterrodsfunctionsasaspacercapturerod.Sevenspacersmaintainfuelrodspacing.Genericmechanicaldesignanalyseswereperformedtoevaluatethesteadystatestrain,transientstrain,claddingfatigue,creepcollapse,claddingcorrosion,hydrogenabsorption,differentialfuelrodgrowth,and,gridspacerspringdesignfortheANF9x9fueldesign.TheRODEX2,RODEX2A,RAHPEXandCOLAPXcodeswereusedinthegenericmechanicaldesignanalyses.AllparametersmeettheirrespectivedesignlimitsasdescribedinReferencell.Thegenericanalysesforthe9x9design(Reference11)areapplicabletotheXN-1,XN-2,ANF-3,andANF-4fueldesignsandsupportamaximum9x9assemblydischargeexposureof40,000HWD/HTU.Basedoncalculations,U2C5operationisprojectedtoresultinapeak9x9assemblyexposurelessthan40,000HWD/MTU.fFortheANF9x9fuel,thedesignissuchthatadequatemarginstofuelmechanicaldesignlimits(e.g.,centerlinemeltingtemperature,transientstrain,etc.)areassuredforallanticipatedoperationaloccurrencesthroughoutthelifeofthefuelasdemonstratedbythefueldesignanalyses(Reference11),providedthatthefuelrodpowerhistoryremainswithinthepowerhistoriesassumedintheanalyses.ThesteadystatedesignpowerprofilefortheANF9x9fuelisshowninFigure3.3ofReferencell.ThispowerprofileisincorporatedintotheTechnicalSpecificationsasanoperatinglimit.Inaddition,aTechnicalSpecificatiohprovisionforreducingtheAPRMscramandrodblocksettingsbyFractionofRatedThermalPowerdividedbyMaximumFractionofLimitingPowerDensity(FRTP/MFLPD)wasincorporated.Thisensures thatANFfueldoesnotexceeddesignlimitsduringanoverpowerconditionfortransientsinitiatedfrompartialpower.TheLHGRcurveusedforcalculatingMFLPDforANF9x9fuelisbasedonANF'sProtectionAgainstFuelFailure(PAFF)lineasshowninFigure3.4ofReference11andisincorporatedintotheTechnicalSpecifications.TheTechnicalSpecificationcurverepresentstheLHGRcorrespondingtotheratioofPAFF/1.2,underwhichcladdingandfuelintegrity(i.e.,1%cladstrainandfuelcenterlinemelting)isprotectedduringAOOs.TheoverallstructuralresponseoftheANF9x9assemblydesignduringSeismic-LOCAeventsisessentiallythesameastheresponseoftheGESxSRassemblydesignthatcomprisedtheinitialSusquehannaSESUnit1core.Thesimilarphysicalpropertiesandbundlenaturalfrequenciesresultinnearlyidentical.structuralresponsesasdiscussedinprevioussubmittals(Reference4).Inaddition,ReferencellpresentstheANF9x9fuelassemblycomponentSeismic-LOCAanalysiswhichshowedlargedesignmarginstothefueldesignlimits.Additionaljustification(Reference13)wasalsoprovidedtotheNRCbyPP8LduringtheUnit2Cycle2reloadlicensingprocess.7.0THERMALHYDRAULICDESIGNXN-NF-80-19(P)(A),Volume4Revision1(Reference6)presentstheprimarythermalhydraulicdesigncriteriawhichrequireanalysestodetermine:(1)hydrauliccomp'atibilityoftheassembliesinthecore,(2)MCPRSafetyLimittypeanalyses,(3)bypassflowcharacteristics,and(4)thermal-hydraulicstability.Theanalysesperformedtodetermineeachoftheseparametersarediscussedinthissection.7.1HdraulicComatibilitComponenthydraulicresistancesforallUnit2Cycle5fuelarethesameforallreloadfuelandhavebeendeterminedinsinglephaseflowtestsoffullscaleassemblies.Thermalhydraulic compatibilityisassuredbecausetheUnit2Cycle5cor'eloadingisentirelyANF9x9fuel.7.2HCPRSafetLimitteanalsisThePP8LStatisticalCombinationofUncertainties(SCU)methodsaredescribedinReference3.WhenusingtheSCUmethodology,thetransienthCPRandtraditionalHCPRsafetylimitanalysesarecombinedintoasingleunifiedanalysis.Asaresult,thehighpressure,highflowsafetylimitisnotrepresentedasasingleHCPRvalue,butratherasaconditionsuchthatatleast99.9%ofthefuelrodsinthecoreareexpectedtoavoidboilingtransition.AsdescribedinAppendixBofReference3,asetof"HCPRSafetyLimittype"analysesareperformedforseveralvaluesofHCPR.TheHCPRSafetyLimittypeanalyseswereperformedbyANFusingthesamemethodsandassumptionsasthetraditionalHCPRSafetyLimitanalysis.AsshowninTablel,.aHCPRvalueof1.06intwoloopoperationassuresthatlessthan0.1%ofthefuelrodsareexpectedtoexperienceboilingtransition.ThemethodologyandgenericuncertaintiesusedintheHCPRSafetyLimittypecalculationsareprovidedinXN-NF-80-19(P)(A),Volume4Revision1(Reference6).TheuncertaintiesusedfortheSSESU2C5HCPRSafetyLimitTypecalculationsarethesameasforU2C4andarepresentedinReference18.TheresultsarepresentedinTable1.DuringU2C5,asinthepreviouscycle,theANF9x9fuelwillbemonitoredusingtheXN-3criticalpowercorrelation.ANFhasdeterminedthatthiscorrelationprovidessufficientconservatismtoprecludetheneedforanypenaltyduetochannelbowduringU2C5.SusquehannaSESisaC-latticeplantanduseschannelsforonlyonefuelbundlelifetime.TheconservatismhasbeenevaluatedbyANFtobegreaterthanthemaximumexpectedhCPR(0.02)duetochannelbowinC-latticeplantsusingchannelsforonlyonefuelbundle 1ifetime.Therefore,themonitoringoftheHCPR1imitisconservativewithrespecttochannelbowandaddressestheconcernsofNRCBulletinNo.90-02(Reference16).ThedetailsoftheevaluationperformedbyANFhavebeenreportedgenericallytotheNRC(Reference17).7.3CoreBassFlowCorebypassflowiscalculatedusingthemethodologydescribedinPL-NF-87-001-A(Reference1).Thecorebypassflowfraction(includingwaterrodflow)forU2C5is8.7%oftotalcoreflowwhichisthesameastheCycle4bypassflowvalueof8.7%.ThebypassflowfractionisusedintheHCPRSafetyLimittypecalculationsandasinputtothecycle.specifictransientanalyses.7.4CoreStabilitCOTRANcorestabilitycalculationswereperformedforUnit2Cycle5todeterminethedecayratiosatpredeterminedpower/flowconditions.TheresultingdecayratioswereusedtodefineoperatingregionswhichcomplywiththeinterimrequirementsofNRCBulletinNo.88-07,Supplement1"PowerOscillationsinBoilingWaterReactors,"(Reference19).Asinthepreviouscycle,RegionsBandCoftheNRCBulletinhavebeencombinedintoasingleregion(i.e.,RegionII),andRegionAoftheNRCBulletincorrespondstoRegionI.RegionIhasbeendefinedsuchthatthedecayratiofor,allallowablepower/flowconditionsoutsideoftheregionislessthan0.90.Tomitigateorpreventtheconsequencesofinstability,entryintothisregionrequiresamanualreactorscram.RegionIforUnit2Cycle5hasbeencalculatedtobeslightlydifferentthanRegionIforthepreviouscycle.
RegionIIhasbeendefinedsuchthatthedecayratioforallallowablepower/flowconditionsoutsideoftheregion(excludingRegionI)islessthan0.75.ForUnit2Cycle5,RegionIImustbeimmediatelyexitedifitisinadvertentlyentered.SimilartoRegionI,RegionIIisslightlydifferentthaninthepreviouscycle.Inadditiontotheregiondefinitions,PPLLhasperformedstabilitytestsinSSESUnit2duringinitialstartupofCycles2,3and4todemonstratestablereactoroperationwithANF9x9fuel.ThetestresultsforU2C2(Reference20)showverylowdecayratioswithacorecontaining324ANF9x9fuelassemblies.AnalysisofdatatakenduringU2C2TwoLoopOperationat60%powerand47%flowresultedina"measured"decayratioof0.33andaCOTRANcalculateddecayratioof0.33.InSingleLoopOperationat55%powerand44%flowthe"measured"decayratiowas0.30andtheCOTRANcalculatedvaluewas0.29.Inaddition,theuseoftheANF"ANNA"softwaretoanalyzeAPRHsignalsfromtheU2C3startupproduceda"measured"decayratioofapproximately0.37at60%powerand46%flow.TheU2C3corecontained556ANF9x9assemblies.TheU2C4corecontains764(fullcore)ANF9x9assemblies.TwoloopstabilitytestssimilartothosedescribedabovewereperformedatBOC4andthetestdatahasbeensenttotheNRC(Reference21).StabilitytestsarenotplannedforU2C5.PPLLbelievesthattheuseofTechnicalSpecificationsthatcomplywithNRCBulletin'88-07Supplement1,andthetestsandanalysesdescribedabove,willprovideassurancethatSSESUnit2Cycle5willcomplywithGeneralDesignCriteria12,SuppressionofReactorPowerOscillations.ThisapproachisconsistentwiththeSSESUnit2Cycle4methodforaddressingcorestability(References4and5).
8.0NUCLEARDESIGNTheneutronicmethodsforthedesignandanalysisoftheU2C5reloadaredescribedinPPELtopicalreportsPL-NF-87-001-A,PL-NF-89-005,andPL-NF-90-001(References1,2,and3),ANFtopicalrep'ortsXN-NF-80-19(A),Vol.1,andVol.1Supplements1and2(Reference22),andANFletterRAC:058:88(Reference23).ThesereportshavebeenreviewedandapprovedbytheNuclearRegulatoryCommissionforapplicationtotheSusquehannaSESreloads,exceptforPL-NF-89-005andPL-NF-90-001whicharebeingreviewedbytheNRC.8.1FuelBundleNuclearDesinTheANF-4fuelbundle.designisa9x9latticewithtwo(2)inert(water)rodsand79fuelrodscontaining150inchesofactivefuel.Thetopsix(6)inchesofeachfuelrodcontainnaturaluraniumandthelower144inches(enrichedzone)ofeachrodcontainenricheduraniumatoneofeightdifferentenrichments.TheANF-4reloadbatchconsistsof232bundleswhichcontainnineburnablepoisonrodswith5.0wt%Gdz0s(9Gd5)blendedwithUOzenrichedto3.40wt%U-235.TheGdz0s-UOzrodsareutilizedtoreducetheinitialreactivityofthebundle.Theaverageenrichmentoftheenrichedzoneis3.54wt%U235forthelatticecontaining9Gd5.Thecorrespondingbundleaverageenrichment(includingthetopnaturaluraniumblanket)is3.43wt%U235.Thenumberoffuelrodsateachenrichmentisgivenbelow:3.54wt%U235Latticewith9Gd5RodEnrichmentwt%U235¹ofRods2.002.202.402.7013215 3.503.944.703.402113159(5wt%GDz0s)TheneutronicdesignparametersandpinenrichmentdistributionarepresentedinTable2andFigure2,respectively.8.2CoreReactivitShutdownMarginforUZC5wasanalyzedusingPP&L'scorephysicsmethods(References1and3)andalowCycle4exposureof9,601HWD/HTU,whichresultsinaconservativelyhighcoldcorereactivityconditionduringCycle5.ShutdownMarginisdefinedasthecorereactivitywithallcontrolrodsfullyinserted,exceptforthestrongestworthcontrolrod,at68'Fandxenon-freeconditions.TheminimumvalueofShutdownMarginoccursat10,125HWD/HTUandis1.093%hk/k.Thecoldall-rods-incorek-effectiveat10,125HWD/HTUis0.96038.ThevalueofR,whichisthedifferencebetweentheBOCShutdownMarginandtheminimumShutdownMarginduringthecycle,is0.036%hk/k.ThecalculatedShutdownMarginatanypointinthecycleiswellinexcessoftheminimum0.38%hk/kTechnicalSpecificationrequirement,andsufficientShutdownMarginwillbeverifiedbytestatBOC5.TheStandbyLiquidControlSystem,whichisdesignedtoinjectaquantityofsodiumpentaboratesolutionthatproducesaboronconcentrationofnolessthan660ppminthereactorcorewithinapproximately90to120minutesafterinitiation,wascalculatedbyPP8Ltoprovideamarginofshutdownofatleast2.7%hk/kwiththereactorinacold,xenonfreestate,andallcontrolrodsattheircriticalfullpowerpositions.ThiscalculationprocessisdescribedinReference3..Thisassuresthatthereactorcanbebroughtfromfullpowertoacold,xenon-freeshutdown,assumingthatnoneofthewithdrawncontrolrodscanbeinserted.Thusfor theCycle5reloadcorethebasisoftheTechnicalSpecificationrequirementismet.8.3ContrastofCcle5CorewithCcle4ThecoreloadingstrategiesforCycles4and5areverysimilarinnature.Cycle4utilizedaconventionalscatterloadingwiththelowestreactivitybundlesplacedintheperipheralregionofthecore.:Cycle5willalsobebasedonthisscatterloadingprinciple.Freshreloadbundleswillbescatterloadedincontrolcellsthroughoutthecoreexceptonthecoreperiphery.ThriceburnedXN-1bundlesandtwiceburnedXN-2bundleswillbeutilizedonthecoreperiphery.TwiceburnedXN-2bundleswillalsobeusedtoconstrainreactivityininteriorcontrolcells.TheonceburnedANF-3andfreshANF-4bundleswillbedistribut'edthroughoutthecoreinamannerwhichyieldsacceptableradialpeakingandprovidesadequatecoldshutdownmarginthroughoutthecycle.BrieflyreviewingthepreviousreloadfuelbundledesignsthatwillremaininthecoreforU2C5(whichareallANF9x9),theCycle2XN-1fuelinitiallycontained4wt%Gdz0~distributeduniformlyovertheenrichedzonesofsevendesignatedrods.TheCycle3XN-2andCycle4ANF-3fuelinitiallycontainedboth4and5wt%Gd,0~distributeduniformlyovertheenrichedzonesofdesignatedrodsinselectedsubbatches.TheCycle5ANF-4fuelbundledesignhasa3.43wt%U235bundleaverageenrichmentandcontains9gadoliniabearingrodsat5wt%Gdz0~.Forreloadcycles,theaxialexposureprofileoftheexposedbundlesprovidesanaxialshapingeffectanddecreasestheneedforaxialvaryinggadoliniainU2C5.Thus,aswasthecasefortheXN-l,XN-2,andANF-3fueldesigns,itisnotnecessarytoincludeaxialvaryinggadoliniaintheANF-4fuelforthepurposesofhotoperatingpowershapecontrol.TheANF-4fuelutilizesanenrichmentdistributiontoyieldalatticeinternalpowerdistributionwhichresultsinabalancedandacceptabledesign relativetoHCPR,HAPLHGR,andLHGRLimits.Inaddition,theXN-l,XN-2,ANF-3,andANF-4fueldesignscontainasix(6)inchnaturaluraniumsectionatthetopofthefuelbundlesinordertoincreaseneutroneconomybydecreasingleakageatthetopoftheactivecore.8.4NewFuelStoraeVaultSentFuelPoolCriticalit8.4.1NewFuelStorageVaultTheoriginalneutronicsanalysisofthecurrentlyinstalledSSESnewfuelstoragevaultwasperformedbyGeneralElectricCompany(GE).GEdidnotlimitthestoredfueltoaspecificenrichmentdistributionorburnablepoisoncontent,butinsteadlimitedthekofthefuellattice(i.e.themaximumenrichedzoneofthebundle)toc1.30.Thisinsuresthat,underdryorfloodedconditions,thenewfuelvaultk-effectiveremainsbelow0.95asspecifiedintheSSESFSAR.SincetheGEanalysiswasforan8x8lattice,ANFperformedcalculationsforthenewfuelvaultassuminga9x9lattice.Theresultsshowthat9x9fuelwithalatticeaverageenrichments3.95wt%U235andanANFcalculatedk~1.388willyieldanewfuelvaultk-effective~.95underdryorfloodedconditions(Reference24).Theabovementionedkiscalculatedforacold(68'F),moderated,uncontrolledfuelassemblylatticeinreactorgeometryatbeginning-of-life(BOL).Themaximumcold,uncontrolled,BOLkoftheANF-4fuelassemblyenrichedzone,ascalculatedbyPPELis1.112.ThisvalueiswellbelowtheANFanalysiscriterionof1.388.ThusfortheANF-4fuelitisconcludedthatadequatemargintopreventnewfuelvaultcriticalityunderdryorfloodedconditionsexists.
'lthoughthenewfuelvaulthasnotbeendesignedtoprecludecriticalityatoptimummoderationconditions(betweendryandflooded),watertightcoversareused,administrativeproceduresareinplacetopreventthiscondition,andcriticalitymonitorshavebeeninstalledasanaddedprecaution.8.4.2SpentFuelPoolTheoriginalneutronics.analysisforthespentfuelpoolaspresentedintheFSARwasperformedbyUtilityAssociatesInternational(UAI).Thebasisoftheanalysisassumedthespentfuelpoolwasloadedwithaninfihitearrayoffresh8x8fuelassembliesatauniformaverageenrichmentof3.25wt%U235containingnoburnablepoison.TheabsenceofburnablepoisonsensuresthatpeakassemblyreactivityoccursatBOL.ANFperformedananalysistodeterminecriteriaforANF9x9fuelthatwillensurethattheSSESSpentFuelPoolk-effectivewillbes.95(Reference25).Theresultingcriterionisthattheaverageenrichmentofthemaximumenrichedzoneofa9x9assemblybes3.95wt%U235.TheenrichmentoftheenrichedzoneoftheANF-49x9fueldesignis3.54wt%U235.Thisenrichmentislessthanthe3.95wt%U235requirement,andthusitisconcludedthatadequatemarginexiststopreventspentfuelpoolcriticalitythroughouttheANF-4fuelassemblylifetime.9.0COREMONITORINGSYSTEMkThePOWERPLEXcoremonitoringsystemwillbeutilizedtomonitorreactorparametersduringCycle5.POWERPLEXincorporatesANF'scoresimulationmethodologyandisusedforbothon-linecoremonitoringandasanoff-linepredictiveandbackuptool.POWERPLEXinputwillbebasedonthe CPH-2/PPLmethodology(Reference3).ThismethodologyhasbeensubmittedtotheNRCbyPPEL.assumptionsintheHCPRSafetyLimi10.0ANTICIPATEOOPERATIONALOCCURRENCESThePOWERPLEXsystemhasbeenoperationalatSSESandutilizedtomonitorreactorparametersduringUnit1Cycles2,3,4,and5andUnit2Cycles2,3,and4.ThePOWERPLEXroutinesarefullyconsistentwithANF'snuclearanalysismethodology(withtheexceptionofCPH-2/PPLinput)asdescribedinXN-NF-80-19(A)Volume1andVolume1Supplement2(Reference22)andsupplementedwiththeVHIST13voidhistorycorrelation(Reference23).Inaddition,themeasuredpowerdistributionandmonitoringrelateduncertaintiesareincorporatedintotheHCPRSafetyLimittypecalculationsasdescribedinANF'sNuclearCritical.PowerMethodologyReportXN-NF-524(A)(Reference18).TheuseofCPH-2/PPLtogenerateinputtothePOWERPLEXroutinesrequiredPP8LtoevaluatethemonitoringrelateduncertaintiesbasedontheuseofCPM-2/PPL.Theseuncertaintiesweredeterminedtobelessthanorequaltothecurrentmonitoringrelateduncertaintiesinordertomaintainthe.validityofthettypecalculations.TheMCPRoperatinglimitsforU2C5weregeneratedwiththePP&LreactoranalysismethodsdescribedinPL-NF-90-001(Reference3).TheU2C5HCPRoperatinglimitsarepresentedasHCPRversusPercentofRatedCoreFlowandHCPRversusPercentCoreThermalPower.Theselimitscovertheallowedoperatingrangeofpowerandflow.AsspecifiedinPL-NF-90-001,sixmajoreventswereanalyzed.Theseeventscanbedividedintotwocategories:corewidetransientsandlocaltransients.Thecorewidetransienteventsanalyzedwere:1)GeneratorLoadRejectionWithoutBypass(GLRWOB),2)FeedwaterControllerFailure(FWCF),k3)RecirculationFlowControllerFailure-IncreasingFlow(RFCF),and 4)LossofFeedwaterHeating(LOFWH)AsdiscussedinPL-NF-90-001,theothercorewidetransientsarenon-limiting(i.e.,wouldproducelowercalculatedhCPRsthanoneofthefoureventsanalyzed).Thelocaltransienteventsanalyzedwere:1)RodWithdrawalError(RWE),and2)FuelLoadingError(FLE).Thefuelloadingerrorevaluationincludesanalysisofbothrotatedandmislocatedfuelassemblies.SufficientanalyseswereperformedtodefinetheMCPRoperatinglimitsasafunctionofcorepowerandcoreflow.AnalyseswerealsoperformedtodetermineMCPRoperatinglimitsforthreeplantequipmentavailabilityconditions:1)TurbineBypassandEOC-RPToperable,2)TurbineBypassinoperable,and3)EOC-RPTinoperable.10.1Core-WideTransientsThePPELRETRANmodelandmethodsdescribedinPL-NF-89-005andPL-NF-90-001(References2and3)wereusedtoanalyzetheGLRWOB,FWCF,andRFCFevents.ThehCPRswereevaluatedusingtheXN-3CriticalPowerCorrelation(Reference26)andthemethodologydescribedinPL-NF-90-001(Reference3).TheGLRWOBandFWCFwereanalyzedintwodifferentways(asdescribedinPL-NF-90-001):1)DeterministicanalysesusingtheTechnicalSpecificationscramspeed(minimumallowed);2)StatisticalCombinationofUncertainty(SCU)analysesatanaveragescramspeedof4.2feet/second.Thus,theTechnicalSpecificationMCPRoperatinglimitscalculatedforU2C5willbeafunctionofscramspeed.
TheLOFWHwasconservativelyanalyzedbyPP&LusingthesteadystatecorephysicsmethodsandprocessdescribedinPL-NF-90-001,andtheLOFWHresultswerefoundtobeboundedbyresultsoftheotherthreecorewidetransients.TheminimumHCPRoperatinglimitrequiredfortheU2C5LOFWHeventis1.17.ResultsoftheGLRWOB,FWCF,andRFCFeventsarepresentedinTables3,4,and5,respectively.10.2LocalTransientsThefuelloadingerror(rotatedandmislocatedbundle)andtheRodWithdrawalError(RWE)wereanalyzedusingthemethodologydescribedinPL-NF-90-001(Reference3).TheresultsoftheseanalysesapplytoallthreeplantequipmentavailabilityconditionspreviouslydescribedinSection10,andtheresultsareindependentofscramspeed.TheRWEanalysissupportstheuseofboththeDuralife160CcontrolbladesandaRodBlockHonitorsetpointof108%.TheHCPRoperatinglimitsthatresultfromtheanalysesoftheseeventsarepresentedinTable6.Theseeventsarenon-limitingforU2C5.10.3ASHEOverressurizationAnalsisInordertodemonstratecompliancewiththeASHECodeoverpressurizationcriterionof110%ofdesignpressure,theHSIVclosurewithfailureoftheHSIVpositionswitchscramwasanalyzedbyPPSLusingthemethodsdescribedinPL-NF-90-001.TheU2C5analysisassumedthatsixsafetyreliefvalveswereoutofserviceandtheHSIVclosuretimewas2.0seconds,whichisconservativecomparedtothecurrentTechnicalSpecificationminimumclosuretimeof3.0seconds.Thereactorvesselcomponentswhosedesignpressureis1250psigshowedtheclosestapproachtothe110%ASHECodecriterion(i.e.,1375psig).Themaximumcalculatedpressureinthiscategorywas 1325.3psig,whichcorrespondstoamarginof49.7psitothelimit.11.0POSTULATEDACCIDENTSThreetypesofaccidentswereevaluatedduringtheUnit2Cycle5analysiseffort:theLossofCoolantAccident(LOCA),theControlRodDropAccident(CRDA),andtheFuelandEquipmentHandlingAccidents.ANFhasanalyzedtheLoss-of-CoolantAccidenttodeterminetheMAPLHGRlimitsfortheANF9x9fuelthatwillcomprisetheUnit2Cycle5core.PPELgeneratedandverifiedtheappropriateLOCAanalysisinputsasdescribedinPL-NF-90-001(Reference3).ANF'smethodologyfortheLOCAanalysisisprovidedinReferences27through29.PP&LperformedtheControlRodDropAccidentanalysistodemonstratecompliancewiththe280cal/gmDesignLimitasdescribedinPL-NF-90-001(Reference3)-usingANF'smethodologyfortheCRDAanalysisasdescribedinXN-NF-80-19(A)Vol.1(Reference22).ANFperformedanevaluationoftheFuelandEquipmentHandlingAccidentswhicharediscussedinSection11.3.11.1Loss-of-CoolantAccidentXN-NF-84-117(P)(Reference30)describesANF'sgenericjetpumpBWR-4LOCAbreakspectrumanalysis.ThisanalysisdeterminedthelimitingbreakforBWR-4'swithmodifiedLowPressureCoolantInjectionlogictobeadouble-endedguillotinebreakintherecirculationpipingonthedischargesideofthepump..Thedischargecoefficientassumedwas0.4,whichisequivalenttoatotalbreakareaof2.8ft.TheanalysisofthiseventforSSES9x9fuelisprovidedinXN-NF-86-65(Reference31).ThelimitingoperatingconditionwasidentifiedinXN-NF-86-65asthehighestpowerandhighestflowpermittedbytheoperatingmap.TheresultsgeneratedbyANFareboundingforreactoroperatingconditionsupto100%ratedpowerand100%ratedflowandassureacceptablepeakcladdingtemperaturesforallANF9x9fuelduringapostulatedLOCAevent.TheLOCAanalysisofXN-NF-86-65(Reference31)was performedforanentirecoreof9x9fuelandthereforeprovidesMAPLHGRlimitsforANF9x9fuelonly.ThegenerationofthelocalpowerdistributioninputtotheheatupcalculationsandverificationofparametersimportanttotheblowdowncalculationwereperformedforU2C5byPP8LinaccordancewiththemethodologydescribedinPL-NF-90-001(Reference3).ThisverificationdeterminedthattheblowdowncalculationresultsareconservativeforU2C5.ANFconfirmedthattheMAPLHGRlimitsinXN-NF-86-65ensurethatthePeakCladdingTemperature(PCT)fortheU2C5ANF-4fuelremainsbelow2200'F,localZr-Hz0reactionremainsbelow17%,andcore-widehydrogenproductionremainsbelow1%forthelimitingLOCAeventasrequiredby10CFR50.TheMAPLHGRsandPCTsforfuelresidentinthe'2C5corearepresentedinTable7.11.2ControlRodDroAccidentANF'smethodologyforanalyzingtheControlRodDropAccident(CRDA)isdescribedinXN-NF-80-19(A)Vol.1(Reference22)andutilizesagenericparametricanalysiswhichcalculatesthefuelenthalpyriseduringpostulatedCRDAsoverawiderangeofreactoroperatingconditions.PP8LgeneratedtheparametersusedintheCRDAanalysisasdescribedinPL-NF-90-001(Reference3).TheU2C5analysiswasperformedusingboundingassumptionssimilartothoseusedintheU2C4analysispresentedinReference4.TheU2C5analysisalsosupportedtheuseoftheDuralife160Ccontrolblades.ForU2C5,theCRDAanalysisresultedinavalueof209cal/gmforthemaximumfuelrodenthalpyandlessthan640fuelrodsexceeding170cal/gmduringtheworstcasepostulatedCRDA.The209cal/gmvalueiswellbelowthedesignlimitof280cal/gmandlessthan640fuelrodsexceeding170cal/gmisboundedbythe770rodsassumedinSection15.4.9oftheSSESFSAR(Reference32).ToensurecompliancewiththeCRDAanalysisassumptions,controlrodsequencingbelow20%corethermalpowermustcomplywithGE'sBankedPositionWithdrawalSequenceconstraints(Reference33).
11.3FuelandEuimentHandlinAccidentsTwoaccidentanalyseswereperformedtodeterminetheoffsitedose'othewholebodyandthyroidatthesiteboundaryresultingfromthedroppingofanobjectontothecore.IntheFuelHandlingAccident,thedroppedobjectisanirradiatedfuelassemblypluschannel,grappleheadandmastweighingatotalof1000poundswhichfallsfromaheightof32.95feetabovethecore.IntheEquipmentHandlingAccident,thedroppedobjectisamassweighing1100poundswhichfallsfromaheightof150feetabovethecore.The32.95feetrepresentsthehighestthatanirradiatedfuelassemblycanbecarriedoverthecore;the1100poundmassisthelargestobjectthatisnotspecificallyevaluatedasaheavyload;andthe150feetrepresentsthemaximumheightthattheoverheadcranecancarryanobjectoverthecore.Foreachofthetwoaccidentsanalyzed,thenumberoffailedfuelrodswasdeterminedandthesubsequentradiologicalreleasesandoffsitedoseswerecalculated.Thenumberoffailedfuelrodsforthetwocasesisdeterminedfromtheenergyofthedroppedassemblageandtheenergyrequiredtofailafuelrod.Theenergyrequiredtofailafuelrodisbaseduponauniform1%plasticdeformationofthecladding.Forconservatism,theminimummaterialpropertiesforzircaloy-2areused.FortheFuelHandlingAccidentanalysis,allfuelrodsinthedroppedassemblyareassumedtofail.Forthefuelassemblieshitbythedroppedassemblageinbothanalyses,thestandardfuelrodsandthetierodsareassumedtohavethesamefailurethreshold.Theenergyofthedroppedassemblagefallingfromtheverticalpositiontoitssidepositionisincludedinthecalculation.Onehalfoftheenergyisassumedtobeabsorbedbythefallingfuelassemblyandnoenergyisassumedtobeabsorbedbythe1100poundobject.forconservatism,noenergyisassumedtobeabsorbedbythefuelpellets.ThenumberoffailedfuelrodsfortheFuelHandlingAccidenteventis121andfortheEquipmentHandlingAccidenteventthenumberoffailedfuelrodsis318.
Theoffsitedosecalculationswereperformedassuming(1)thefissionproductinventoriescalculatedbytheORIGENcomputercode(Reference37)increasedbyafactorof1.5,(2)theaccidentoccurs24hoursafterreactor.shutdown,(3)thefissiongasreleasefractionsareobtainedfromRegulatoryGuide1.25,(4)thefuelpooldecontaminationfactoris100foriodineand1fornoblegases,(5)thestandbygastreatmentsystemremovalefficiencyis99%foriodine,and(6)theatmosphericdispersionfactor,breathingratefactor,anddoseconversionfactorsareequaltothoseusedinChapter15.7.4oftheSusquehannaSESFSAR.Foreachofthetwohandlingaccidentsanalyzed,theresultsareshowninTable8.AsshowninTable8theFuelandEquipmentHandlingAccidentcalculateddosesaremuchlessthan25%ofthe10CFR100limits.12.0SINGLELOOPOPERATIONTosupportsingleloopoperationforU2C5,ANFperformedHCPRSafetyLimitcalculationsconsideringsingleloopoperationpower/flowconditionsandassociatedsingleloopoperationuncertainties.TheresultsshowthattheNCPROperatingLimitmustbeincreasedby0.01wheninsingleloopoperation.The0.01increaseintheOperatingLimitisaresultoftheincreasedmeasurementuncertaintiesassociatedwithsingleloopoperation.ANFperformedareviewofthetwoloopoperationlimitinganticipatedoperationaloccurrencesconsideringsingleloopoperation.Previousanalyses(References34and35)indicatedthatothereventswhichcouldbeaffectedbysingleloopoperationwerenon-limitingwhenanalyzedundersingleloopoperatingconditions.Undersingleloopoperatingconditions,steadystateoperationcannotexceedapproximately76%powerand60%coreflowbecauseofthecapabilityoftheoperatingrecirculationpump.Thus,itwasdeterminedthatwhenoperatingatlowpower/flowconditions,thetwoloopoperationanticipatedoperationaloccurrencesremainlimiting.ThetwoloopHCPRoperatinglimitsplus 0.01conservativelyprotectthefuelfromanytransientinsingleloopoperation.ItwasdeterminedthatthesingleloopoperationLOCAanalysispresentedinXN-NF-86-125(Reference36)isboundedbythetwoloopLOCAanalysis.Inaddition,ANFanalyzedthepumpseizureaccidentfromsingleloopoperatingconditionsonagenericbasisfortheSusquehannaUnits(Reference7).TheresultsofthegenericanalysisshowthatsingleloopoperationoftheSusquehannaUnitswithsingleloopHCPRoperatinglimitsprotectsagainsttheeffectsofthe,pumpseizureaccident.Thatis,foroperationatthesingleloopoperatingHCPRlimit,theradiologicalcons'equencesofapumpseizureaccidentfromsingleloopoperatingconditionsarebutasmallfractionofthe10CFR100guidelines.Previousanalyses(Reference34)haveshownthatotheraccidentswhichcouldbeaffectedbysingleloopoperationwerenon-limitingwhenanalyzedundersingleloopoperatingconditions.BasedonthevesselinternalvibrationanalysisperformedbyGE,the80%recirculationpumpspeedrestriction,previouslydiscussedinReference34,willbemaintainedforU2CSsingleloopoperation.TheresultsdiscussedpreviouslyinSection7.4oncorestabilityalsoapplyundersingleloopoperatingconditions.OneofthestabilitytestsperformedduringthestartupofSusquehannaSESUnit2Cycle2wasperformedundersingleloopoperatingconditions.Themeasureddecayratiowas0.30(a=0.064)at55%power/44%flow.ANFperformedananalysisofthesetestswiththeirCOTRANcomputercodeandcalculatedadecayratioof0.29.Thistestdata,thestabilitycalculationresultsforU2C5,andtheU2C5TechnicalSpecificationswhichcomplywithNRCBulletin88-07,Supplement1supportsingleloopoperationduringU2C5.
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11.XN-NF-85-67(P)(A),Revision1,"GenericMechanicalDesignforExxonNuclearJetPumpBWRReloadFuel,"ExxonNuclearCompany,Inc.,September,,1986.12.XN-NF-84-97,Revision0,"LOCA-SeismicStructuralResponseofanENC9x9JetPumpFuelAssembly,"ExxonNuclearCompany,Inc.,December1984.13.PLA-2728,"ResponsetoNRCguestion:Seismic/LOCAAnalysisofU2C2Reload,"LetterfromH.W.Keiser(PP&L)toE.Adensam(NRC),September25,1986.14.XN-NF-82-06(P)(A),Supplement1,Revision2,"gualificationofExxonNuclearFuelforExtendedBurnupSupplement1ExtendedBurnupgualificationofENC9x9Fuel,"May1988.15.PLA-2585,"ProposedAmendment78toLicenseNo.NPF-14,"LetterfromH.W.Keiser(PP&L),toE.Adensam(NRC),January16,1986.16.NRCBulletinNo.90-02,"LossofThermalMarginCausedbyChannelBoxBow,"March20,1990.17.RAC:030:90,"LossofThermalMarginCausedbyChannelBoxBow,"LetterfromR.A.Copeland(ANF)toR.C.Jones(NRC),April9,1990.18.XN-NF-524(A),Revision1,"ExxonNuclearCriticalPowerMethodologyforBoilingWaterReactors,"ExxonNuclearCompany,Inc.,November1983.19.NRCB88-07,Supplement1,"PowerOscillationsinBoilingWaterReactors(BWRs)"USNRCBulletin,December30,1988.20.XN-NF-86-90,Supplement1,"SusquehannaUnit2Cycle2StabilityTestResults,"ExxonNuclearCompany,Inc.,January1987.21.PLA-3344,"Unit2/Cycle4Stability,Data,"LetterfromH.W.Keiser(PP&L)toW.R.Butler(NRC),February28,1990.
22.XN-NF-80-19(A),Volume1,andVolume1Supplements1and2,"ExxonNuclearMethodologyforBoilingWaterReactors:NeutronicMethodsforDesignandAnalysis,"ExxonNuclearCompany,Inc.,March1983.23.RAC:058:88,"VoidHistoryCorrelation,"LetterfromR.A.Copeland(ANF)toH.W.Hodges(NRC),September13,1988.24.XN-NF-86-44,Revision1,"CriticalitySafetyAnalysisSusquehannaNewFuelStorageVaultwithExxonNuclearCompany,Inc.9x9ReloadFuel,"ExxonNuclearCompany,Inc.,Hay1986.25.XN-NF-86-45,Revision1,"CriticalitySafetyAnalysisSusquehannaSpentFuelStoragePoolwithExxonNuclearCompany,Inc.9x9ReloadFuel,"ExxonNuclearCompany,Inc.,Hayl986.26.XN-NF-512-P-A,Revision1andSupplement1,Revision1,"XN-3CriticalPowerCorrelation,"October,1982.27.XN-NF-80-19(A),Volumes.2,2A,2B,and2C,"ExxonNuclea'rMethodologyforBoilingWaterReactors:EXEHBWRECCSEvaluationModel,"ExxonNuclear,Company,Inc.,September1982.28.XN-NF-CC-33(A),Revision1,"HUXY:AGeneralizedHultirodHeatupCodewith10CFR50AppendixKHeatupOption,"ExxonNuclearCompany,Inc.,November1975.29.XN-NF-82-07(A),Revision1,"ExxonNuclearCompanyECCSCladdingSwellingandRuptureHodel,"ExxonNuclearCompany,Inc.,November1982.30.XN-NF-84-117(P),"GenericLOCABreakSpectrumAnalysis:BWR3and4withModifiedLowPressureCoolantInjectionLogic,"ExxonNuclearCompany,Inc.,December1984.31.XN-NF-86-65,"SusquehannaLOCA-ECCSAnalysisMAPLHGRResultsfor9x9Fuel,"ExxonNuclearCompany,Inc.,Hay1986.
32.SusquehannaSteamElectricStation,Units1and2,FinalSafetyAnalysisReport.33.NED0-21231,"BankedPositionWithdrawalSequence,".GeneralElectricCompany,January1977.034.PLA-2885,"ProposedAmendment52toLicenseNo.NPF-22,"LetterfromH.W.Keiser(PP&L)toW.R.,Butler(NRC),June30,1987.35.PLA-2935,"AdditionalInformationon.ProposedAmendment52toLicenseNo.NPF-22,"October30,1987.36.XN-NF-86-125,"SusquehannaLOCAAnalysisforSingleLoopOperation.Analysis,"ExxonNuclearCompany,Inc.,November1986.37.N.J.Bell,"ORIGEN-TheORNLIsotopeGenerationandDepletionCode,"ORNL-4628,OakRidgeNationalLaboratory,Hay1973.rp0192i.jhe:el FIGURE1SSESUNIT2,CYCLE5CORELOADINGPATTERN61595755535149474543413937"312927252321191715137531%+00+0+%+0%yx6+%go%ykX%"K+%go%gB%goKX%0%XOKgx%gx%+X%+00%0%X%Kg0+%+0Og&0%0%X%%+X%+XK+X%+0%+%+O%+~%+O6+%+0%+6O+%+O%OgkWOO~+%O+O%+6%+X6X0%%+0X%D%%+xK~k6+0&+06060%+O~+~DyxOy%6+%0+0%X0+%6+%%0+%0+%KyK%yKX%+00+0X%%0KKX+%0+0%+X0+00%66S+%O+O6+X%+%X%6600%+60+0X+%6X%%6+%0+0X+%0+00%66%+X0+0X+%0+0%0%XK%+00~0X%+%%+%%+%%+KXX0%%+X%+00+%0+%%X%X%X%%+00+0D%X%%+X%+0%+6%+6X~66+%%X%6+%Ogd6%06%X%x+~~+%%+X%goQ%X%%+0OgOXXX%XRQ0+%0+%%iX%0Ot%+%XX++%>++aX+6XjKKOOK%+o%+~+0%00%+6%+0%+%+XK%+XO+X%+O%+X+%X+%Oy%X+%Xy%Xg%%0%0OgdDyo0+%go%6%X%0%0X+%O+X+%X+%X+i0+%0+%6+%0+%+%X6%~+%~+%O+%+~Kg6%+0%+K0%0%+0%+6+0KKX+6X40GE~00020406081012141618202224262830323436384042444648505254565860XEIANF9X9/XN-1(3.31/7GD4)-85EIANF9X9/ANF-3(3.17/9GD4)-100INQANF9X9/XN-2(3.33/9GD4)-1406ANF9X9/XN-1REINSERT(3.31/7GD4)-3EIANF9X9/XN-2(3.33/10GD5)-96KIANF9X9/ANF-4(3.43/9GD5)-232CIANF9X9/ANF-3(3.33/9GD5)-104ANF9X9/XN-1REINSERT(3.31/7GD4)-4REPAIRED-1gSYMMETRICS-3Q-31 FIGURE2MhKHHMhKHHHHHHHM'MHHHMHHHMHMhKMILLRODS(1)LLRODS(3)LRODS(2)MLRODS(15)MRODS(21)MHRODS(13)HRODS(15)M~RODS(9)WRODS(2)2.00w/oU-2352.20w/oU-2352.40w/oU-2352.70w/oU-2353.50w/oU-2353.94w/oU-2354.70w/oU-2353.40w/oU-235+5.0w/oGd203InertWaterRod,U2C5ANF-43.54wtXU235LatticeEnrichmentDistribution eTABLE1UNIT2CYCLE5HCPRSAFETYLIMITTYPEANALYSESMCPRVALUEPERCENTOFRODSINBOILINGTRANSITIONTWO-LOOPOPERATIONSINGLE-LOOPOPERATION0.960.991.021.061.101.071.405%0.748%0.313%0.097%0.024%0.079%e TABLE2NOMINALSSESOPERATINGCONDITIONSCoreThermalPowerTotalCoreFlowReactorPressureCoreInletSubcoolingNumberofFuelAssembliesNumberofControlRods3293NWt100Hlb/hr1020psia24.0Btu/ibm764185 TABLE3U2C5CALCULATEDHCPROPERATINGLIHITSGENERATORLOADREJECTIONW/0BYPASSHodeofOperationDeterministicAnalysisTechnicalSpecificationScramSeedSCUAnalysis4.2ft/secScramSpeedBypass&EOC-RPTOperableBypassInoperableEOC-RPTInoperable1.471.471.541.321.321.35 TABLE4U2C5CALCULATEDHCPROPERATINGLIHITSFEEDWATERCONTROLLERFAILUREHodeof0erationBypass8EOC-RPTOperableBypassInoperableEOC-RPTInoperablePower%rated100846540100846540100846540DeterministicAnalysisTechnicalSpecificationScramSeed1.311,371.501.731.561.641.771.911.381.411.531.76SCUAnalysis4.2ft/secScramSeed<I31'"'.321.411.551.381.431.541.631.251.311.421.57(I)NotanSCUanalysis,valueusedfromdeterministicanalysisatTechnicalSpecificationScramspeed.
TABLE5U2C5CALCULATEDMCPROPERATINGLIMITSRECIRCULATIONFLOWCONTROLLERFAILURECoreFlow%Rated30,37456074.9CalculatedMCPR"'eratinLimit1.831.691.571.431.32(1)ConservativelyanalyzedatTechnicalSpecificationscramspeed.Resultsapplytoall3modesofoperation(i.e.,BypassandEOC-RPToperable,Bypassinoperable,andEOC-RPTinoperable).
TABLE6U2C5CALCULATEDHCPROPERATINGLIHITSLOCALTRANSIENTSEventRodWithdrawalErrorHislocatedBundleRotatedBundleCalculatedHCPR0eratinLimit1.271.221.28 TABLE7UNIT2CYCLE5LOCAHEATUPRESULTS'JLimitingBreak:Double-endedguillotinepipebreak,Recirculationpumpdischargeline,0.4dischargecoefficient.AssemblyAverageExposure(GWd/HTU)HAPLHGR'KW/FT)XN-152PeakCladTemperatureDereeFANF-3ANF-4XN-152ANF-3ANF-4PeakLocalHWR"Percent1015202530354010.210.210.210.210.29.68.98.27.520602069212121402173201618391752167619981937207921262161199618311744167021023.93.73.74.85.22.71.00.70.52.61.43.15.02.51.00.70.54.03'etalwaterreaction.Peakcladtemperaturesandmetalwaterreactor(HWR)shownareboundingforANF-9x9XN-1andXN-2fuelinSusquehannaUnit2.TheANF-4fueltypeissimilartotheANF-3fueltypeloadedinCycle4exceptthatitisslightlymoreedgepeakedatthelimitingexposurepointforPCTandHWR.ThisexposurepointwasanalyzedfortheANF-4fueltypetoconfirmthattheANF-3fuelpeakcladdingtemperaturesarebounding.
TABLE8FUELANDEQUIPMENTHANDLINGACCIDENTRESULTSTwo-HourSiteBoundaryRadiologicalDoseWholeBodyDoseThyroidDose10CFR100LimitsRem2530025%of10CFR100LimitsRem75FuelHandlingAccidentResults(Rem1.311.81EquipmentHandlingAccidentResultsRem3.404.74