ML17328A930
| ML17328A930 | |
| Person / Time | |
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| Site: | Cook  |
| Issue date: | 11/30/1990 |
| From: | FECTEAU M W, KOVACIK W P, SIGNORELLA T L INDIANA MICHIGAN POWER CO. (FORMERLY INDIANA & MICHIG |
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| NUDOCS 9102250099 | |
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CRITICALITYANALYSISOFTHEDONALDC.COOKNUCLEARPLANTFUELRACKSREGION1CHECKERBOARDOFBURNED&FRESHFUELASSEMBLIESNovember1990M.W.FecteauT.L.SignorellaW.P.KovacikJ.R.SeekerF.K.Torres91022500999i02i5PDRADOCK050003i5PPDR
TABLEOFCONTENTS1.0Introduction1.1DesignDescription1.2DesignCriteria~~~~~~~1~\~~2.0AnalyticalMethods2.1CriticalityCalculationMethodology2.2ReactivityEquivalencingMethodology~~3~~~~~~~~~43.0CriticalityAnalysisofRegion1Checkerboard3.1KENOReactivityCalculations3.2PHOENIXReactivityEquivalencing3.3PostulatedAccidents3.4SensitivityAnalysis4.0SummaryofCriticalityResultsArrangement..........6~~~~~~~~~6I'~~~~~~~r'~9~~~~~9~~~~~~~~~~~~~~~~~10Bibliography25TableofContents LISTOFTABLESTableTableTableTableTable1.FuelParametersEmployedinCriticalityAnalysis2.BenchmarkCriticalExperiments[5,6]3.ComparisonofPHOENIXIsotopicsPredictionstoYankeeMeasurements4.BenchmarkCriticalExperimentsPHOENIXComparison5.DataforUMetalandUO~CriticalExperiments1213Core5141516ListofTables 1p1',I LISTOFILIUSTRATIONSFigureFigureFigureFigureFigureFigureFigure1.DonaldC.CookNuclearPlantSpentFuelPoolStorageCellNominalDimensions~~~1~2.DonaldC.CookNuclearPlantSFPRegion1CheckerboardFuelAssemblyLoadingSchematic3.DonaldC.CookNuclearPlantSchematicforSFPInterfaceBoundaryBetweenRegions1and24.DonaldC.CookNuclearPlantSFPRegion1"Burned"FuelAssemblyMinimumBurnupvs.initialUEnrichmentCurve5.Sensitivityofk~<<toEnrichmentintheDonaldC.CookNuclearPlantSFPRegion1StorageAreawithCheckerboardLoading6.Sensitivityofke<<toCenter-to-CenterSpacingintheDonaldC.CookNuclearPlantSFPRegion1StorageAreawithCheckerboardLoading7.Sensitivityofke<<to8LoadingintheDonaldC.CookNuclearPlantSFPRegion1StorageAreawithCheckerboardLoading18192021222324ListofIllustrations L'CltgS,I5 1.0,INTRODUCTIONThisreportpresentstheresultsofacriticalityanalysisoftheDonaldC.CookNuclearPlantSpentFuelPool(SFP)storagerackforthestorageofWestinghouseandANF(AdvancedNuclearFuel)15x15and17x17fuelassemblies,ThisanalysisconsidersacheckerboardarrangementofburnedandfreshfuelassemblieswithintheSFPRegion1area.IlsTheDonaldC.CookNuclearPlantSFPstoragerackwaspreviouslyanalyzedforthestorageofWestinghouse15x15and17x17fuelastwoseparatespentfuelarraysorregions.Region1wasanalyzedfornominalenrichmentsupto4.95w/oUusingathreeoutoffourfuelassemblystoragearrangement.335Region2wasanalyzedfornominalenrichmentsupto3.95w/oUusingallavailablestoragecells.Enrichmentsgreaterthan3.95w/owerealsoallowed'ntheRegion2area,providedrestrictionsonburnupweremet.ThisreportdescribesanalternatefuelassemblystoragearrangementfortheRegion1areawhichutilizesallavailablestoragelocations.Thisarrangementregainsthetwenty-fivepercentstoragecelllossofthepreviousthreeoutoffourstoragearrangement,bycheckerboardingburnedandfreshfuelassembliestogetherwithinthesameregion.Burnupcredit,whichtakesintoconsiderationthechangesinfuelandfissionproductinventoryresultingfromdepletioninthereactorcore,willbeusedtoestablishtheburnuprequirementsoftheburnedfuelassembliesinthecheckerboard.ThecriticalityandburnupcreditanalysisofthecheckerboardarrangementispresentedinSection3ofthisreport.ThisDonaldC.CookNuclearPlantSFPcriticalityanalysisisbasedonmain-tainingkyar~50.95forstorageofWestinghouse15x15STD(Standard)andOFA(OptimizedFuelAssembly),17x17STD,OFAandVANTAGE5,andANF15x15and17x17fuelassemblies.ThefuelparametersrelevanttothisanalysisaregiveninTable1onpage12.1.1DESIGNDESCRIPTIONTheDonaldC.CookNuclearPlantSFPstoragecelldesignisdepictedsche-maticallyinFigure1onpage18withnominaldimensionsgivenonthefigure.TheRegion1checkerboardarrangementofburnedandfreshfuelassembliesisshowninFigure2onpage19andanexampleoftheinterfaceboundarybe-Introduction
'1sElJ tweentheRegionicheckerboardandexistingRegion2storageareasisgiveninFigure3onpage20.ThetotalnumberofSFPlocationsdesignatedasRegion1or2islefttotheutilitytodetermine.TheboundarybetweenthetworegionscanbedrawnanywherewithintheSFPracks,buttheinterfacemustbeconfiguredsuchthatthereisaonerowcarryoverofthepatternestablishedinRegion1intoRegion'.Thisassuresthatthepatternoffuelassembliesattheinterfacewillnotbemorereactivethanthepatternsallowedoneithersideoftheboundary.Figure3onpage20illustrates.theRegion1to2boundaryinterface.Inthisfigure,thehorizontally-linedboxesrepresentRegion1"fresh"fuelstoragelo-235cationswhicharequalifiedforfreshfuelenrichmentsupto5.0w/oU.Thediagonally-linedboxesrepresentRegion1"burned"fuelstoragelocationswhicharequalifiedforstorageoffuelassemblieswhichsatisfytheRegion1burnup-enrichmentrequirementsofFigure4onpage21.Theblankboxes"rep-resentRegion2fuelassemblystoragelocationswhicharequalifiedforstorageoffuelassemblieswhichsatisfytheRegion2enrichment-burnuprequirementsasreportedinthepreviouscriticalityreport.Inthisfigure,thecheckerboardpatternofRegion1burnedassemblies{diagonally-linedboxes)hasbeencarriedintotheRegion2areabyonerow.TheremainingcellsinthefirstrowofRegion2arethenfilledwithfuelassemblieswhichmeettherequirementsforstorageinRegion2(blankboxes).Inthisway,therequirementsforfuelas-semblystorageinbothregionsaresatisfied,andanygroupingoffourassem-bliesattheinterfaceboundarywillalwaysbelessthanorequalinreactivitytosimilargroupsoffourassembliesallowedoneithersideoftheboundary.1.2DESIGNCRITERIACriticalityoffuelassembliesinafuelstoragerackispreventedbythedesignoftherackwhichlimitsfuelassemblyinteraction.Thisisdonebyfixingtheminimumseparationbetweenfuelassembliesandinsertingneutronpoisonbe-tweenfuelassemblies.Thedesignbasisforpreventingcriticalityoutsidethereactoristhat,includinguncertainties,thereisa95percentprobabilityata95percentconfidencelevelthattheeffectiveneutronmultiplicationfactor,kyar~,ofthefuelassemblyarraywillbelessthan0.95asrecommendedbyANSI.57.2-1983andReference2.Introduction
'IpL 2.0ANALYTICALMETHODS2.1CRITICALITYCALCULATIONMETHODOLOGYThecriticalitycalculationmethodandcross-sectionvaluesareverifiedbycomparisonwithcriticalexperimentdataforfuelassembliessimilartothoseforwhichtheracksaredesigned.Thisbenchmarkingdataissufficientlydiversetoestablishthatthemethodbiasanduncertaintywillapplytorackconditionswhichincludestrongneutronabsorbers,largewatergapsandlowmoderatordensities.ThedesignmethodwhichinsuresthecriticalitysafetyoffuelassembliesinthespentfuelstoragerackusestheAMPX'ystemofcodesforcross-sectiongenerationandKENOIVforreactivitydetermination,The227energygroupcross-sectionlibrarythatisthecommonstartingpointforallcross-sectionsusedforthebenchmarksandthestoragerackisgeneratedfromENDF/B-V'ata.TheNITAWLprogramincludes,inthislibrary,theself-shieldedresonancecross-sectionsthatareappropriateforeachparticulargeometry.TheNordheimIntegralTreatmentisused.Energyandspatialweightingofcross-sectionsisperformedbytheXSDRNPM'rogramwhichisaone-dimensionalS~transporttheorycode.Thesemultigroupcross-sectionsetsarethenusedasinputtoKENOIV'hichisathreedimensionalMonteCarlotheoryprogramdesignedforreactivitycalculations,Asetof33criticalexperimentshasbeenanalyzedusingtheabovemethodtodemonstrateitsapplicabilitytocriticalityanalysisandtoestablishthemethodbiasanduncertainty.Theexperimentsrangefromwatermoderated,oxidefuelarraysseparatedbyvariousmaterials(B4C,steel,water,etc)thatsimulateLWR(LightWaterReactor)fuelshippingandstorageconditionstodry,harderi7ispectrumuraniummetalcylinderarrayswithvariousinterspersedmaterials(Plexiglasandair)thatdemonstratethewiderangeofapplicabilityofthemethod.Table2onpage13summarizestheseexperiments.Theaverageke~tofthebenchmarksis0.992.Thestandarddeviationofthebiasvalueis0.0008bk.The95/95onesidedtolerancelimitfactorfor33valuesis2.19.Thus,thereisa95percentprobabilitywitha95percentconfidencelevelthattheuncertaintyinreactivity,duetothemethod,isnotgreaterthan0.0018Ik.AnalyticalMethods3 1rkAvI"IIII<s'll REACTIVITYEQUIVALENCINGMETHODOLOGYSpentfuelstorage,intheRegion1areaoftheDonaldC.CookNuclearPlantSFP,isachievablebymeansoftheconceptofreactivityequivalencing.Theconceptofreactivityequivalencingispredicateduponthereactivitydecreaseassociatedwithfueldepletion,Aseriesofreactivitycalculationsisperformedtogenerateasetofenrichment-fuelassemblydischargeburnuporderedpairswhichallyieldtheequivalentkatewhenthefuelisstoredintheRegion1racks.Thedatapointsonthereactivityequivalencecurvearegeneratedwithatrans-porttheorycomputercode,PHOENIX.PHOENIXisadepletable,two-dimensional,multigroup,discreteordinates,transporttheorycode.A25energyi'0>groupnucleardatalibrarybasedonamodifiedversionoftheBritishWIMSlibraryisusedwithPHOENIX.Astudywasdonetoexaminefuelreactivityasafunctionoftimefollowingdischargefromthereactor.FissionproductdecaywasaccountedforusingCINDER'CINDERisapoint-depletioncomputercodeusedtodeterminefissionproductactivities.Thefissionproductswerepermittedtodecayfor30yearsafterdischarge.Thefuelreactivitywasfoundtoreachamaximumatapprox-imately100hoursafterdischarge.Atthistime,themajorfissionproductpoison,Xe,hasnearlycompletelydecayedaway.Furthermore.thefuelre-activitywasfoundtodecreasecontinuouslyfrom100hoursto30yearsfol-lowingdischaige.Therefore,the'mostreactivetimeforafuelassemblyafterdischargefromthereactorcanbeconservativelyapproximatedbyremovingtheXThePHOENIXcodehasbeenvalidatedbycomparisonswithexperimentswheretheisotopicfuelcompositionhasbeenexaminedfollowingdischargefromareactor.Inaddition,anextensivesetofbenchmarkcriticalexperimentshasbeenanalyzedwithPHOENIX.ComparisonsbetweenmeasuredandpredicteduraniumandplutoniumisotopicfuelcompositionsareshowninTable3onpage14.ThemeasurementsweremadeonfueldischargedfromYankeeCore5ThedatainTable3onpage14showsthattheagreementbetweenPHOENIXpredictionsandmeasuredisotopiccompositionsisgood.TheagreementbetweenreactivitiescomputedwithPHOENIXandtheresultsof81criticalbenchmarkexperimentsissummarizedinTable4onpage15.Keyparametersdescribingeachofthe81experimentsaregiveninTable5onpage16,Thesereactivitycomparisonsagainshowgoodagreementbetweenexper-imentandPHOENIXcalculations.Sincetheburnuphistoryoffuelassemblieswhichwillbedischargedinthefutureisnotknownexactly,areactivityuncertaintyisappliedtotheburnup-dependentreactivitiescomputedwithPHOENIX.Anuncertaintywhichincreaseslinearlywithburnupto0.014kat30,000MWD/MTUisappliedtothePHOENIXcalculationalresultsinthedevelopmentoftheRegion1burnuprequirements.AnalyticalMethods 1p0 Thisuncertaintyisconsideredtobeveryconservativeandisbasedoncon-siderationofthegoodagreementbetweenPHOENIXpredictionsandmeasure-ments(comparisonresultswiththeYankeeCoreexperimentsandS1benchmarkexperimentsaregiveninTable3onpage14andTable4onpage15)andonconservativeestimatesoffuelassemblyisotopicbuildupvariances.FortheDonaldC.CookNuclearPlantSFPRegion1analysis,thePHOENIXcalculationsforthemaximumburnupof31,000MWD/MTUincludeareactivityuncertaintyof0.0103Dk.AnalyticalMethods5 C3I,l~>V,J(A+
3.0CRITICALITYANALYSISOFREGION1CHECKERBOARDARRANGEMENTThissectiondevelopsanddescribestheanalyticaltechniquesandmodelsem-.ployedtoperformthecriticalityandreactivityequivalencinganalysisforstor-ageoffuelintheDonaldC.CookNuclearPlantSpentFuelPool(SFP)Region1area.ThisanalysisconsidersacheckerboardarrangementofburnedandfreshfuelassemblieswithintheSFPRegion1area.Section3,1describestheKENOreactivitycalculationsforthecheckerboardar-rangementofburnedandfreshfuelassemblies.FortheKENOanalysis,the"burned"fuelassemblieswillberepresentedbyfreshfuelassemblieswithalowenrichment.Section3.2willthendescribethePHOENIXreactivityequiv-alencinganalysiswhichwillestablishtheburnuprequirementsofthe"burned"fuelassembliesinthecheckerboard.Section3.3willdiscusspostulatedacci-dentsandSection3.4willpresenttheresultsofthePHOENIXsensitivitycal-culationsforenrichment,cellcenter-to-centerspacing,andpoisonloading,3.tKENOREACTIVITYCALCULATIONSThefollowingassumptionsareusedtodevelopthenominalcaseKENOmodelforcheckerboardstorageofburnedandfreshfuelassembliesin,theRegion1area(refertoFigure2onpage19forlayout).1.Westinghouse17x17OFAfuelassemblieswithnominalenrichmentsof5.0w/oUare.modelledinthe"fresh"fuelstoragelocationsofthecheck-erboard.Theenrichmentof5.0w/oUwaschosentoconservativelyboundallpresentandfuturefuelassemblyenrichments.EvaluationoftheWestinghouse15x15"and17x17andANF15x15and17xl7fuelassembliesshowsthattheWestinghouse17x17OFAfuelassemblyisthemostreactivefueltypeatthisenrichment.TheWestinghouse17x17VANTAGE5fueldesignparametersrelevanttothecriticalityanalysisarethesameastheOFAparametersandwillyieldequivalentresults.Therefore,onlytheWestinghouse17x17OFA'uelassemblyisanalyzedinthe"fresh"fuelcheckerboardlocations(seeTable1onpage12forfuelparameters).2.Westinghouse17xl7STDfuel'assemblieswithnominalenrichmentsof2.3w/oUaremodelledinthe"burned"fuelstoragelocationsofthecheck-erboard.EvaluationoftheWestinghouse15x15and17x17andANF15xl5CriticalityAnalysisofRegion1CheckerboardArrangement
and17x17fuelassembliesshowsthattheWestinghouse17x17STDfuelassemblyismorereactivethanotherWestinghouse17xl7andANF15x15and17x17fueltypesandapproximatelyequivalent(within0.0015hk)totheWestinghouse15x15fuelassemblyatthisenrichment.Therefore,onlytheWestinghouse17x17STDfuelassemblyisanalyzedinthe"burned"fuelcheckerboardlocations(seeTable1onpage12forfuelparameters).3.Allfuelassembliescontainthehighestauthorizedenrichmentoverthefinite144inchlengthofeachrod,areatthemostreactivepointinlife,andnocreditistakenforanyburnableabsorberinthefuelrodsoranynaturalenrichmentaxialblankets.Theseassumptionsresultinconservativecalcu-lationsofreactivity.4.Thefuelpelletsareassumedtobeat96%oftheoreticaldensity,andnocreditistakenfordishingorchamfering.5.NocreditistakenforanyUorUinthefuel,norisanycredittakenforthebuildupoffissionproductpoisonmaterial.6.Themoderatorispurewateratatemperatureof68'F.A-conservativevalueof1.0gm/cmisusedforthedensityofwater.7.Nocreditistakenforanyspacergridsorspacersleeves.8.Allavailablefuelcellsareutilized.Fuelassembliesarearrangedinacheckerboardpattern,asdepictedinFigure2onpage19.9.Thearrayisinfiniteinlateralextentandfiniteinaxialextentwhichallowsneutronleakagefromonlytheaxialdirection.10.Theminimumpoisonmaterialloadingof0.02grams8persquarecenti-meterisusedthroughoutthearray.TheKENOcalculationforthenominalcaseresultedinake<<of0.8932witha95percentprobability/95percentconfidenceleveluncertaintyof+0.0045.Thenominalcaseresultcanbecomparedtothe'worstcaseresulttodeterminetherelativeimpactofapplyingtheworstcaseassumptions.ThenominalcaseisalsousedasthecenterpointforthesensitivityanalysisdiscussedinSection3.4.Themaximumk~r~undernormalconditionsarisesfromconsiderationofme-chanicalandmaterialthicknesstolerancesresultingfromthemanufacturingprocessinadditiontoasymmetricpositioningoffuelassemblieswithinthestoragecells.Westinghouseinternalstudiesofasymmetricpositioningoffuelassemblieswithinthestoragecellshaveshownthatsymmetricallyplacedfuelassembliesyieldequalorconservativeresultsinrackke<<.ThesheetmetaltolerancesareconsideredalongwithconstructiontolerancesrelatedtothecellI.D.,andcellcenter-to-centerspacing.FortheRegion1racks.thisresultsinthereductionofthenominalcentertocenterspacings.totheirminimumvalues.CriticalityAnalysisotRegion1CheckeiboardArrangement 8t 23sFurthermore,fuelenrichmentsareincreasedby0.05w/oUtoconservativelyaccountforenrichmentvariability.Enrichmentsareassumedtobe5.05w/oUforthe"fresh"fuelcellsand2.35wloUforthe"burned"fuelcells.Thus,the"worstcase"KENOmodeloftheRegion1storagerackscontainsminimumcentertocenterspacings,symmetricallyplacedfuelassemblies,andmaximumfuelassemblyenrichments.Basedontheanalysisdescribedabove,thefollowingequationisusedtode-velopthemaximumkettfortheDonaldC.CookNuclearPlantSFPRegion1racks:kett=kworst~Bmetrtoo~Boert~Besml[(ks)worst~(ks)'metrtoo]where:kwarstworstcaseKENOke<<thatincludesmaterialtolerances,andmechanicaltoleranceswhichcanresultinspacingsbetweenfuelassemblieslessthannominalBmethoo=methodbiasdeterminedfrombenchmarkcriticalcomparisonsBpertBesmbiastoaccountforpoisonparticleself-shielding.Thisstandardtermaccountsfortheincreasedneutrontransmissionthroughthepoisonplateduetotheinherenteffectsofpoisonparticleself-shielding,andhasbeenanalyticallydeterminedforpoisonplatessimilartothoseusedinthisanalysis.biastoaccountforthereactivitydifferencebetweentheRegion1SFP"burned"checkerboardlocationsloadedwithWestinghouse17x17STDfuelassembliesat2.3w/oU'ersusWestinghouse15x15fuelassembliesat2.3w/oUksworst=95/95uncertaintyintheworstcaseKENO.ke<<ksmettoo=95/95uncertaintyinthemethodbiasSubstitutingcalculatedvaluesintheorderlistedabove,theresultis:kett=0.9295+0.0083+0.0014+0.0015+l[(0.0044)i(0.0018)]=0.9455Sinceketfislessthan0.95includinguncertaintiesata95/95probability/confidencelevel,theacceptancecriteriaforcriticalityismetfortheRegion1checkerboardarrangementof"fresh"fuelcellsatanominalenrichmentof5.0w/oUand"burned"fuelcellsatanominalenrichmentof2.3w/oU235CriticalityAnalysisofRegion1CheckerboardArrangement
\IIIIt 3.2PHOENIXREACTIVITYEQUIVALENC!NGSpentfuelstorage.intheRegion1checkerboardarea,isachievablebymeansoftheconceptofreactivityequivalencing.Theconceptofreactivityequiv-alencingispredicateduponthereactivitydecreaseassociatedwithfuelde-pletion.Aseriesofreactivitycalculationsareperformedtogenerateasetofenrichment-fuelassemblydischargeburnuporderedpairswhichallyieldtheequivalentke<<whenthefuelisstoredintheRegion1"burned"fuelstoragecells.Themaximumk~<<forstorageofspentfuelintheRegion1checkerboardareaisdeterminedusingthemethodsdescribedinSection2.Figure4onpage21representscombinationsoffuelenrichmentanddischargeburnupyieldingthesamerackmultiplicationfactor(ki<<)astherackloadedwitha"checkerboardof5.0w/oUfuelinthe"fresh"fuelcellsand2.3w/oUfuel(atzeroburnup)inthe"burned"fuelcells.ThiscurvewasobtainedbyfirstcalculatingtheequivalentreactivitypointsusingPHOENIXandthennormalizingthepointstothenominalKENOcalculationdescribedinSection3.1~Theuncertaintyassoci-atedwiththereactivityequivalencemethodologyisincludedinthedevelopmentoftheburnuprequirements.ThisuncertaintywasdiscussedinSection2.2.Figure4onpage21showstheconstantke<<contourgeneratedfortheDonaldC.CookNuclearPlantRegion1checkerboard.NoteinFigure4onpage21theendpointat0,MWD/MTUwheretheenrichmentis2.3w/o,andat31,000MWD/MTUwheretheenrichmentis5.0w/o.Theinterpretationoftheendpointdataisasfollows:thereactivityoftheRegion1checkerboardrackcontaining5.0w/oUfuelatzeroburnupinthe"fresh"fuelcellsand5.0w/oUfuelat31,000MWD/MTUburnupinthe"burned"fuelcellsisequivalenttothere-235activityoftheRegion1checkerboardrackcontaining5.0w/oUfuelatzeroburnupinthe"fresh"fuelcellsand2.3w/oUfuelatzerobur'nupinthe"burned"fuelcells.ItisimportanttorecognizethatthecurveinFigure4onpage21isbasedonaconstantrackreactivityforthatregionandnotonaconstantfuelassemblyreactivity.Inthisway,theenvironmentofthestoragerackanditsinfluenceonassemblyreactivityisimplicitlyconsidered.3.3POSTULATEDACCIDENTSMostaccidentconditionswillnotresultinanincreaseinke<<oftherack.Ex-amplesarethelossofcoolingsystems(reactivitydecreaseswithdecreasingwaterdensity)anddroppingafuelassemblyontopoftherack(therackstructurepertinentforcriticality'snotexcessivelydeformedandthedroppedfuelassemblyhasmorethantwelveinchesofwaterseparatingitfromtheactivefuelheightofstoredfuelassemblieswhichprecludesinteraction).However,accidentscanbepostulatedwhichwouldincreasereactivity(i.e.,misloadingafuelassemblywithaburnupandenrichmentcombinationoutsideCriticalityAnalysisofRegion1CheckerboardArrangement If oftheacceptableareainFigure4onpage21,ordroppingafuelassemblybetweentherackandpoolwall).Fortheseaccidentconditions,thedoublecontingencyprincipleofANSIN16.1-1975isapplied.Thisstatesthatoneisnotrequiredtoassumetwo-unlikely,independent,con'currenteventstoensureprotectionagainstacriticalityaccident.Thus,foraccidentconditions,thepresenceofsolubleboroninthestoragepoolwatercanbeassumedasare-alisticinitialconditionsincenotassumingitspresencewouldbeasecondun-likelyevent,Thepresenceofapproximately2000ppmboroninthepoolwaterwilldecreasereactivitybyabout0.25Dk.Inperspective,thisisaboutfivetimesmorenegativereactivitythancouldbeaddedifeverycellintheSFPwerefilledwithfresh5.0w/oUfuelassemblies.Thus,forpostulatedaccidents,shouldtherebeareactivityincrease,ki<<wouldbelessthanorequalto0.95duetotheeffectofthedissolvedboron.SincetheDonaldC.'ookNuclearPlantSFPwillbemaintainedataboronconcentrationof2400ppm,additionalmarginwillexisttothe0.95limit.3.4SENSITIVITYANALYSISToshowthedependenceofke<<onfuelandstoragecellsparametersasre-questedbytheNRC,thevariationoftheke<<withrespecttothefollowingparameterswasdevelopedusingthePHOENIXcomputercode:1.Fuelenrichment,witha0.50w/oUdeltaaboutthepominalcaseenrichment.Forthissensitivity,boththe"fresh"and"burned"fuelas-semblyenrichmentswereadjustedsimultaneously.2.Center-to-centerspacingofstoragecells,withahalfinchdeltaaboutthenominalcasecenter-to-centerspacing.3.Poisonloading,witha0.01gm-B/cmdeltaaboutthenominalcasepoisonloading.ResultsofthesensitivityanalysisfortheRegion1checkerboardstoragear-rangementareshowninFigure5onpage22throughFigure7onpage24.CriticalityAnalysisofRegion1CheckerboardArrangement10 oI'VPP0g+
4.0SUMMARYOFCRITICALITYRESULTSTheacceptancecriteriaforcriticalityrequirestheeffectiveneutronmultipli-cationfactor,ka<<,tobelessthanorequalto0.95,includinguncertainties,underallconditionsforthestorageoffuelassembliesintheSpentFuelPool(SFP).ThisreportshowsthattheacceptancecriteriaforcriticalityismetfortheDonaldC.CookNuclearPlantSpentFuelPool(SFP)Region1checkerboardofburnedandfreshfuelassemblies.ThisconclusionisvalidforthestorageofWestinghouse15x15STDandQFA,and17x17STD,QFAandVANTAGE5,andANF15x15and17x17fuelassemblieswiththefollowingnominalenrichmentlimits:SFPRegion1"Fresh"Fuel'5.0wloUSFPRegion1"Burned"Fuel<5.0w/oU,withburnuprestrictionsgivenbyFigure4onpage21ThecheckerboardarrangementtobeusedforthestorageofburnedandfreshfuelassembliesintheRegion1areaisshownonFigure2onpage19.AnexampleoftheinterfaceboundarybetweentheRegion1checkerboardandtheRegion2areaisgivenbyFigure3onpage20.TheanalyticalmethodsemployedhereinconformwithANSIN18.2-1973,"Nu-clearSafetyCriteriafortheDesignofStationaryPressurizedWaterReactorPlants,"Section5,7,FuelHandlingSystem;ANSI57.2-1983,"DesignObjectivesforLWRSpentFuelStorageFacilitiesatNuclearPowerStations,"Section6.4.2;ANSIN16,9-1975,"ValidationofCalculationalMethodsforNuclearCriticalitySafety";andwiththeNRCStandardReviewPlan,Section9.1.2,"SpentFuelStorage."SummaryofCriticalityResults hTable1.fuelParametersEmployedinCriticalityAnalysisPARAMETERWSTO/OFAWOFA/V5WSTD15x1517x1717x17ANF15x15ANF17xl7NumberofFuelRodsperAssemblyRodZirc-4CladO.D,(inch)CladThickness(inch)FuelPei.letO.D.(inch)FuelPelletDensity(%ofTheoretical)2040.4220.02430.3659962640.3600.02250.3088962640,3740.02550.3225962040.4240.03000.3565962640.3600.02500.303096FuelPelletDishingFactor(%)RodPitch(inch)NumberofGuideTubesGuideTubeO.D.(inch)GuideTubeThickness(inch)0.00,563200.5330.0170.00.496240.4740.0160.00.496240.4820.0160.00.563200.5450.0170.00.496240.4800.016NumberofInstrumentTubesInstrumentTubeO.D.(inch)InstrumentTubeThickness(inch)0.5330.0170.4740.0160.48-20.0160.5450.0170.4800.01612
)p4'ltE, Table2.BenchmarkCriticalExperiments[5,6]GeneralOescrIptionSnrIcheentv/oU235Rei'lectorSeparatIngliaterIaISolubI~BoronpixIKeir1.U02rod2.U02rod3.V02rod4.U02rod5.V02rod6.U02rod7.U02rod8.V02rod9.U02rod10.U02rod11.U02rod12.U02rod13.U02rod14.U02rod15.U02rod16.U02rod17.U02rod18.U02rod19.U02rod20.U02rod21.U02rod22.Ueetai23.Umetal24.Uraetal25.Ueetal26.Uaetai27.Ueetal28.Uraetai29.Vrectal30.Uaeta131.Uraetai32.Uoctal33.UraetallatticelettlcelettIcelettIcelattIcelatticelatttcelattice1atticelatticelatticelatticelaitlcelettice1atticelattice1attIcelatticelatticelatticeIattIcecyIinderscylinderscylInderscy1InderscylinderscylinderscylInderscylinderscylinderscylinderscyIinderscy'IInders2.462.462.462.462.462.462.462.462.462.462.462.462.462.462.462.462.462.462'62.462.4693.293.293.293.293.293.293.293.293.293.293.2.93'watervaterwaterwaterwet~Iwaterwaterwaterwa't~rwaterwaterwaterwaterwaterwatervaterwaterwater~sterwa't~rwat~rbarebarebarebar~barebar~bareparerflnbareparaf'fInparaftinpara'lrInvaterwaterwater84Cpins84Cpins84Cpins84Cpins84CpinswaterwaterstainlesssteelstainlesssteelberatedaluNInuaborateda1unlnueboratedaluminumboretedaluxinueboratedaluminumboratedaluoinunboraCedaiueinueboratedaluminumboratedalureinueaIrairairairairairplexig1assplexiglassplexiglasspIexig1assplexigIassplexiglass01037764000000143514217159239512148719763432072000000000000+/-+/-0.98570.99060.98960.99140.98910.99550.98890.99830.99310.99280.99670.9943+/'/-+/>>+/-+/-+/y/>>y/>>+/-+/>>+/>>y/>>+/-+/-+/-+/-+/y/>>+/-+/+/-+/-+/-+/-0.98920.98840.98320.98480.98950.98850.99210.99200.99390.99050.99760.99470.99280.99220.9950+/-0.9941+/-0.9928+/-0.9968+/1.0042+/-0.9963+/-0.9919+/.0028.0018.0015.'0025.0026.0020.0027.0025.0028.0025.0020.0019.0023.0023.0021.0024.0020.0022.0019.0020.0020.0020.0020.0025.00'19.0026.0027.0030.0041.0018.0019.0030.003213 I
Table3.CornparisonofPHOENIXIsotopicsPredictionstoYankeeCore5MeasurementsQuantity(AtomRatio)U235/UU236/UU238/UPu239/UPu2,40/UPu241/UPu242/UPu239/U238Mass(Pu/U)FISS-PU/TOT-PU%Difference-0.67-0.28-0.03~3o27+3.63-7.01,-0.203.24~1.41-0.0214
~~
Table4.BenchmarkCriticalExperimentsPHOENIXComparisonDescriptionofExperimentsNumberofExperimentsPHOENIXketchUsingExperimentSucklingsUOtAIcladSScladBoratedH~OSubtotal1419400.99470.99440.99400.9944U-MetalAlcladTOTAL41811.00120.997815 Table5.pataforIJMetalandUO$CriticalExperiments(PartlOf2)CaaeNuaberCellTypeA/0H20/UU-2'35rlatloFuelOenalty(a/CC)Pellet01aaeter(CM)Mater1~1C1adCladClad00Tlllckneaa(Cli)(CM)LatticeP1tcn(CM)BoronPPM123456789101112131415161718192021222324252627282930313233343837383940414243HexaHexaHexaHexaHexaHexaHexaHexaSquare5quareSquar~SquareSquareSquare5quareSquareSquareSquareSquareSquareSquareSquareSquareSquareSquareSquar~Squar~5quar~5quareSquar~SquareSquareSquareSquar~SquareHexaHexaHexaHexaHexaHexaHexaHexa1.3281.3281.32d1.3281.32S1.32d1.3281.3282.7342.7342.7342.7342.7342.7342.7342.7343.7453.7453.7453.7453.7453.7453.7453.7454.0694.0694.0692.4903.0373.0374.0694.0694.0694.O692.4902.0962.0962.0962.0962.0961.3071.3071.3073.023.954.953.924.892.883.584.832.182.923.867.028.4910.3$2.504.5$2.504.514.514.514.5$4.5$4.514.512.552.552.142.842.648.162.593.538.029.902.842.063.094.128.148.201.011.512.027.537.537'37.527.5210.5310.5310.5310.1$10.1810.1810.1810.1810.1810.1810.1810.2710.3710.3710.37$0.3710.3710.3710.379.469.469.4610.249.289.289.459.459.459.4510.2410.3810.38$0.3810.3$10.3818.9018.90lb.901.52651.52651.5265.9855.9S55.9728.9728.9728.7620.7620.7620.7620.7620.7620.7620.7620.7544.7544.7544.7544,7544.7544.7'544.75441.12781.$2781.12781.02971.12681.12681.12681.12681.12681.12681.02971.52401.52401.52401.52401.52401.52401.52401.5240A1ua1nuhAluh1nuaAluh1nuaAluh1nuaA1uh1nuhAluri1nuaAluh1nuaAIuri1nua55-30455-30455-30455-30455-30455-30455-30455-30455-30455-30455-30455-30455-30455-30455-30455-30455-30455-30455-304A1uh1nuh55-30455-30455-30455-30455-30455-304Aluh1nuaA1uh1nuaA1uh1nuhAlure1nuhAluhlnuaAIuri1nuaAluri1nuaAlualnuaAlua1nua1.69161.69161.69161.$5061.15061.15061.15061.1506".8594.$594.8594.8594.S594.8594.B594.8594:e600.8600:eeoo.$600.8600.8600.8600.86001.20901.20901.20901.20601.17011.27011.27011.27011.27011.270$1.20601.69161.,69$61.69161.69161.69161.69161.6916.1.6916.07110.07110.07110~07110.071$0.07110.07110.07110.04085.04085.04085.04085.04085.04085.04085.04085.04060.04060.04060.04060.04060.04060.04060.04060.04060.04060.04060.08130.07163.07163.07163.07163.07163.07163.08130.07112.07112.07112.07112.071$2.07112.07112.071122'0502.35902.51201~55801.6520'I.55801.65201.80601.02871.10491.19381.45541.56211.68911.06171.25221,.06$71.25221.2522$.25221.25221.25221.25221.2522$.51131.51131.45001.51131.55502.19801.55501.68402.19802.38101.51132.17372.40522.61622.98913.32552.17422.40542.61620.00.00.00.00.00~00.00.00.00.00.00.00.00.00~00,00~00.00.0456.0709.01260.01334~01477.00.03392.00.00.00.00.00.00.00.00.01677.00.00.00.00.00.00.0000.0'6
Table5.DataforUMetalandUO>CriticalExperiments(part20f2)CaseCol)NuraberTypeFue)PelletA/0H20/UDensityDiameterU-235Ratio(6/CC)(CM)CIactMaterialOQClad(CM)CIadLatticeThicknessPitch.Boron(CM)(CM)PPM44454647484950515253545556575859606162636465666768697071727'37475767778798081HexaHexaHexaHexaHexaHexaHexaHexaHexaHexaHexaHexaHexaHexaHexaHexaHexaHexaHexaHexaHexaHexaHexaHexaHexaHexaHexaHexaHexaHexaHexaHexaHexaHexaHexaHexaHexaHexa1.3071.307t.1601.1601.1601.1601.1601.0401.0401.0401.0401.0401.3071.3071.3071.3071.307t.f601.1601.1601.160t.1601.1601.1601.160S.1601.0401.0401.0401.040I.0401.0401.3101.3101.1591.1591.3121.3123.0118.904.0218.901.0118.901.5118.902.02'8.903.0118.904.0218.901.0118.901.5118.902.0218.903.0118.904.0218.901.0018.901.52i8.902.0218.903.02t8.904.0218.90t.5218.902.0218.903.02tS.904.0218.90t.QQ)$.901.5218.902.0218.903.0218.904.02,18.901.3318.901.5S18.901.8318.902.3318.902.8318.903.8318.902.0218.883.0118.882.02f8.883.0118.882.0318.883.0218.881.52401.52401.52401.52401.52401.52401.52401.52401.52401;52401.52401.5240.9830.9830.9830.9830.9830.9830.9830.9830.9830.9830.9830.9830.9830.983019.05019.05019.05019.05019.05019.05Q1.52401.52401.52401.5240'9830.9830AIuraInuraAIumInumAIum1numAIuraInumA)urninurnA)urnInurnAIura1rwmAluraIrwmAturn1rwraAluminumAIum1numAIum1rwraAluminumAIura1numAlum1numAluminurnA)urnInumAIumInurnAIum1numAluminumAlurainurnA)umtnumAIum1numAIum1numAIumInumAIuminumAIura1numAluminumAIurainurnAIuminumAlum1numAIuraInumA'Ium1numAIura1numA)umirwmA)um1numAlum1rwmAIuminum1.69161.69161.69161.69161.69161.69161.69161.69161.69161.69161.69161.69t61.1506t.f5061.1506.t.15061.1506t5061.1506f.15061.1506S.15061.15061.15061.15061.15062.05742.05742.05742.05742.05742.05741.69161.6916f.69161.69161~15061.1506.07112~07112.07112.07112.07112.07112.07112.OT112.07112~OTS12~07112.07112.07112.07112.07112.07)12.07112~07112.07112.07112.071t2.07112.OT112.07112.071t2.07112.07620.07620.07620.07620.07620.07620.07112'07112.07112.07112.07tt2.071122.98963.32492~17422,40542,61622.98963.32492.17422.40542.6I622.98963.32491.4412I.59261.72471.96092~1742I~59261.72471.96092~17421.44121.59261.724796092~17422.86873'0863.1425'.39423.62844'5662.61602.99002~61602'9900I.72501.96100.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.00.0QQ0.00.00.017 lfPr SEEDETAILA8.884"0.196"1.224"CELLCENIERIOCEMIER(10.5"t.03"Stainlesssteel~.Ot"At07l"B,C-AIgPRAL~.otAt075"StainlessSteelDETAILAINSIDEOFCELLFigure1.OonaldC.CookNuclearPlantSpentFuelPoolStorageCellNominalOimensions IPP RegionIFreehFuelRegionIBurnedFuelFigure2.DonaldC,CookNuclearPlantSFPRegion1CheckerboardFuelAs-semblyLoadingSchematic t'I IIII(IIRegion1to2Boundaryon1Region2RegionlFreshFue1Reg1onIBurnedFuelRegion2BurnedFuelFigure3.DonaldC.CookNuclearPlantSchematicforSFPinterfaceBoundaryBetweenRegions1and220
~wj's>IAE 32302826~24C52220DIIIIACCEPTABLEIILI18w16IIIIIIIIIV)o12I1TII~108IIJLINOTACCIIEPTABLEIITI2.32.52.72.93.13.3)53.53.73.94.14.34.54.74.95.1Uc35ENRlCHMENT(I/O)Figure4.DonaldC.CookNuclearPlantSFPRegion1"Burned"FuelAssemblyMinimumBurnupvs.initialUEnrichmentCurve21 1~AI'gI'e
'.92.91.90III.88III.87).554.251.804.502.05'.302.554.755.005.25UENRICHMENT(W/0)2.803.055.505.758ORALHELDAT.02GMB/CMCENTERTOCENTERHELDAT10.50"Figure5.SensitivityofkerftoEnrichmentintheDonaldC.CookNuclearPlantSFPRegion1StorageAreawithCheckerboardLoading22
.92.91IIIIIIII.89.88IIIIIIIIII.8f.8010.010.210.410.610.8CENTER-TO-CENTERSPACING(INCHES)11.011.2BORALHELDAT.02GMB/CMCHECKERBOARDENRICHMENTHELDAT2.3/5.0W/0Figure6.Sensitivityofke<<toCenter-to-CenterSpacingintheDonaldC.CookNuclearPlantSFPRegion1StorageAreawithCheckerboardLoading23 1y'A
.910905II-I-IIIIIIIIIIIIII-+-IIIIII1-III-.900II-I-IIIIIIIItII+III-III-III890II-I-IIt-II-t-III-IIt.885IIIIII880.008.010.012.014.016.018.020.022.924.026POISONLOAD(GM8Iv/CM)028.030.032CENTERTOCENTERHELDAT10.50"CHECKERBOARDENRICHMENTHELDAT2.3/5.0W/0Figure7.SensitivityofkenttoBLoadingintheDonaldC,CookNuclearPlantSFPRegion1StorageAreawithCheckerboardLoading24 4pVSpy1l BIBLIOGRAPHY1.W.A.Boyd,et.al.,CriticalityAnalysisoftheDonaldC.CookNuclearPlant,FuelRacksOctober1989.2.NuclearRegulatoryCommission,LettertoAllPowerReactorLicensees,fromB.K.GrimesOTPositionforReviewandAcceptanceofSpentFuelStorageandHandlingApplicationsApril14,1978.3.W.E,Ford-III,CSRL-V:ProcessedENOFIB-V227-Neutron-GroupandPointwiseCross-SectionLibrariesforCriticalitySafety,ReactorandShieldingStudies,ORNLICSOITM-160,June1982.4,N.M.Greene,AMPX:AModularCodeSystemforGeneratingCoupled~MultigroupNeutron-GammaLibrariesfromENOFIB,ORNL/TM-3706,March1976.5,L.M.PetrieandN.F.Cross,KENOIV--AnImprovedMonteCarloCriticalityProgram,ORNL-4938,November1975.6.M.N.Baldwin,CriticalExperimentsSupportingCloseProximityWaterStorageofPowerReactorFuel,BAW-1484-7,July1979.t7.J.T.Thomas,CriticalThree-DimensionalArraysofU(93.2JMetalCylinders,NuclearScienceandEngineering,Volume52,pages350-359,1973.8.D.E.Mueller.W.A.Boyd,andM.W,Fecteau(WestinghouseNFD),QualificationofKENOCalculationswithENDFIB-VCrossSections,AmericanNuclearSocietyTransactions,Volume56,pages321-323,June1988.9.A.J.Harris,ADescriptionoftheNuclearDesignandAnalysisProgramsforBoilingWaterReactors,WCAP-10106,June1982.10.Askew,J.R.,Fayers,F.J.,andKemshell,P.B.,AGeneralDescriptionoftheLatticeCodeWINS,JournalofBritishNuclearEnergySociety,5,pp.564-584,1966.11.England,T.R.,ClNOER-AOne-PointOepletionandFissionProductProgram,WAPD-TM-334,August1962.12.Melehan,J.B.,YankeeCoreEvaluationProgramFinal'eport,WCAP-3017-6094,January1971.Bibliography25
ATTACHMENT2TOAEP:NRC:1071NDESCRIPTIONOFPROPOSEDT/SsCHANGESAND10CFR50.92SIGNIFICANTHAZARDSCONSIDERATIONANALYSIS
'srtE;~wJP~t Attachment2toAEP:NRC:1071NPage1IntroductionThisletterrequests,T/Sschangesinthestoragepatterninthespentfuelpool.Thechanges'involveSection5(DesignSection)andarebasedoncriticalityandthermal-hydrauli'cconcerns.Asdiscussedlaterinthisattachment,'nalyseshavebeenperformedthatdemonstratetheacceptabilityoftheproposedT/Sschangeswithregardtothecriticalityconcerns.Wehavealsoconcludedthatthecurrentanalysisofrecordforthethermal-hydraulicconcernsremainsbounding.DescritionofChanesTheproposedT/Sschangesareasfollows:1)InUnits1and2T/S5.6.1.1,subparagraphc.lhasbeenmodified,theexistingsubparagraphc.2hasbeenslightlymodifiedandrenumberedasc.3,andanewsubparagraphc.2hasbeenadded.2)Subparagraphc.lidentifies"Region1"ofthespentfuelstorageracksforstorageofWestinghousefueltypeswithmaximumnominalfuelassemblyenrichmentsof3.95weightpercentorgreater.FuelstoredinRegion1mustbestoredinacheckerboardconfigurationalternatingWestinghouseCategory1andCategory2fuel,asshowninFigure5.6-1(seeAttachment1,Figure3).Category1fuelisdefinedasWestinghousefuelshowninFigure5.6-2as"acceptableforstorageasCategory1fuel."Category2fuelisdefinedasWestinghousefuelwithanenrichmentgreaterthan3.95weightpercentU-235andaburnuplessthan5,550MWD/MTUshownontheshadedareaofFigure5.6-2.ThesearethemaximumenrichmentsandminimumburnupsforWestinghousefuelthatcanbestoredinRegion2,asdiscussedinthenextparagraph.3)Thenewsubparagraphc.2identifies"Region2"ofthespentfuelstorageracks.ThisRegion2shallbefor-thestorageofWestinghousefuelwithanenrichment1essthanorequalto3.95weightpercentU-235orwithanenrichmentgreaterthan3.95weightpercentU-235butwithaburnupgreaterthanorequalto5,550MWD/MTU,andExxon/ANFfuelofanenrichmentlessthanorequalto4.23weightpercentU-235fora17x17assemblyorlessthanor,equa'1to3.50weightpercentU-235fora15x15assembly.ThemaximumenrichmentandminimumburnuplimitsforWestinghousefuelthatcanbestoredinRegion2werejustifiedinourprevioussubmittalAEP:NRC:1071F.
0 Attachment2toAEP:NRC:1071NPage24)Theexistingsubparagraphc.2isrenumberedasc.3andisbeingmodifiedslightlytoaddresstheboundaryconditionbetweenRegions1and2.ThisboundaryconditionisthatthecheckerboardpatternrequirementforRegion1mustbecarriedintoRegion2byatleastonerow.Thisboundaryconditionisillustratedintherevisedfigure,Figure5.6-1.5)ThesecondpageofTable5.7-1intheUnit2T/SsisincorrectlylabeledasTable5.9-1.Thishasbeenrevised.Beingpurelyeditorial,thischangeisnotdiscussedinthesignificanthazardsconsiderationportionofthisattachment.SummarofCriticalitAnalsesAttachment1containscriticalityanalysesforRegion1ofthespentfuelpoolandfortheboundarybetweenRegions1and2,preparedforusbyWestinghouse.TheanalyseswereperformedinsuchawaythattheyboundalltypesofWestinghousefuelcurrentlyinuseorplannedforuseintheCookNuclearPlant.InaccordancewiththeacceptancecriteriaofChapter9.1.2(SpentFuelStorage)oftheNRCStandardReviewPlan,theWestinghouseanalysesdemonstratethatthecenter-to-centerspacingbetweenfuelassembliesandanystrong,fixedneutronabsorbersinthestorage,racksaresufficienttomaintainthearray,whenloadedwithfuelassemblieswithamaximumnominalenrichmentof4.95weightpercentU-235andfloodedwithpurewater,inasubcriticalconditionwithkfflessthan0.95.Inordertoachieveacceptableresults,Westinghousehasdeterminedthatfreshfuelassemblieswithnominaleff.enrichmentsabove3.95weightpercentU-235mustbestoredinRegion1ofthespentfuelstorageracksinacheckerboardpatternconfigurationalternatingCategory1andCategory2fuel.Inaddition,thischeckerboardpatternofRegion1mustbecarriedintoRegion2byatleastonerow.Itshouldalsobepointedoutthatonefuelassembly,whichhasanenrichmentlargerthan4.55weightpercentU-235,wouldhaveakfflargerthan0.95whenoutof'hepoisonedracksandwith0ppmofboroninthespentfuelpool.However,itcanbeshownthatwithonly1000ppmofboron,thekofafuelassemblywithanenrichmentof4.95weightpercentU-235wouldbeconservativelylesseffthan0.95.TheboronconcentrationinthespentfuelpoolisrequiredbyT/S3.9.15tobegreaterthan2400ppmbymeasurementwhenfuelassemblieswithenrichmentgreaterthan3.95weightpercentU-235andwithburnuplessthan5,550MWD/MTUareinthefuelstoragepool.
1r4lgP Attachment2toAEP:NRC:1071NPage3Thermal-HdraulicConsiderationsTheCookNuclearPlantUpdatedFSARdiscussesanalysesperformedtodemonstratetheadequacyofthespentfuelpoolcoolingsystemtoremovedecayheat,andalsoan,assessmentofthetimeitwouldtaketoreachbulkboilingintheeventallspentfuelpoolcoolingislost.ThemostrecentanalysisofthistypewasperformedbyANFinsupportofusingassembliescapableof50,000MWD/MTUexposure.TheanalysesweredocumentedinANFReportNo.ANF-88-09.ThisanalysiswassubmittedinourletterAEP:NRC:1071datedAugust19,1988,andsupportedtheAmendments118(Unit3.)and104(Unit2)T/Sschanges.'TheanalysesweremodifiedslightlyasdocumentedinRev.1toANF-88-09tocorrectanerrorindeterminingthepoolheatload.Therevisionresultedinachangeinthetimetoreachbulkboilingfrom8.6hoursto5.5hours.)TheUnit2Vantage5assembliesareintendedforuseuptoanaveragedischargeburnupofonly48,000MWD/MTU.Also,theUnit2powerlevelremainsthesameat3411MWt.Therefore,spentfuelpoolcoolinganalysesdocumentedinANF-88-09,Rev.1,willboundtheVantage5assembliesandnonewanalysesarebeingsubmitted.10CFR50.92SinificantHazardsConsiderationAnalsisPer10CFR50.92,aproposedamendmenttoanoperatinglicensevillnotinvolveasignificanthazardsconsiderationiftheproposedamendmentsatisfiesthefollowingthreecriteria:Doesnotinvolveasignificantincreaseintheprobabilityorconsequencesofanaccidentpreviouslyanalyzed,2)Doesnotcreatethepossibilityofanewordifferentkindofaccidentfromanyaccidentpreviouslyanalyzedorevaluated,orDoesnotinvolveasignificantreductioninamarginofsafety.Criterion1Westinghousehasperformedanalysesthatdemonstratetheacceptabilityoftheproposedchangeswithregardtocriticality.Theanalysesdemonstratethatfuelstoredinthespentfuelpoolwillremainsubcriticalunderdesignbasisconditions.However,accidentsorincidentscantakeplacewhichwouldincreasereactivitysuchasdroppingafuelassemblybetweentherackandpoolwallorinadvertentlyplacingafuelassemblyinthewronglocation.Forthoseconditions,thedoublecontingencyprincipleofANSIN16.1-1975canbeapplied.Thatprinciplestatesthatoneis'notrequiredtoassumetwounlikely,independent,concurrenteventstoensureprotectionagainstcriticality.Thus,thepresenceof A
Attachment2toAEP:NRC:1071NPage4greaterthanorequalto2400ppmofsolubleboroninthespentfuelpoolcanbeassumedasarealisticinitialcondition,sincenotassumingitwouldbeasecondunlikelyevent.Thereactivityofthefuelstoredinthespentfuelpoolwouldbedecreasedbyabout0.25delta-k,withapproximately2000ppmofboron;thatis,foranaccidentoranincidentresultinginanincreaseinreactivity,keffwouldremainlessthanorequalto0.95duetotheeffectofthedissolvedboron.Inaddition,paragraph2.3oftheSERrelatedtoAmendments118and104forCookNuclearPlantUnits1and2,respectively,statesthat"thereactivityreductionduetotherequiredpoolborationof2400ppmofboronmorethanoffsetsthepotentialreactivity'ncreasesfrompostulatedfuelmishandlingaccidents."ItisconcludedthattheproposedT/Sschangesshouldnotinvolveasignificantincreaseintheprobabilityorconsequencesofapreviouslyanalyzedaccident.Criterion2TheWestinghouseanalysesdemonstratecontinuedacceptabilityofthespentfuelpoolregardingcriticality.TheT/Sschangeswillnotresultinphysicalchangestotheplant(otherthantothefuelassemblies,whichwerethesubjectoftheWestinghouseanalyses).Therefore,webelievetheproposedT/Sschangeswillnotcreatethepossibilityofanewordifferentkindofaccidentfromanypreviouslyevaluated.Criterion3Westinghousehasperformedanalysesthatdemonstratetheacceptabilityoftheproposedchangeswithregardtocriticality.Theanalysesdemonstratethatthefuelstoredinthespentfuelpoolwillremainsubcriticalunderdesignbasisconditions.However,accidentsorincidentscantakeplacewhichwouldincreasereactivitysuchasdroppingafuelassemblybetweentherackandpoolwallorinadvertentlyplacingafuelassemblyinthewronglocation.Forthoseconditions,thedoublecontingencyprincipleofANSIN16.1-1975canbeapplied,Thatprinciplestatesthatoneisnotrequiredtoassumetwounlikely,independent,concurrenteventstoensureprotectionagainstcriticality.Thus,thepresenceofgreaterthanorequalto2400ppmofsolubleboroninthespentfuelpoolcanbeassumedasarealisticinitialcondition,sincenotassumingitwouldbeasecondunlikelyevent.Thereactivityofthefuelstoredinthespentfuelpoolwouldbedecreasedbyabout0.25delta-k,withapproximately2000ppmofboron;thatis,foranaccidentoranincidentresultinginanincreaseinreactivity,keffwouldremainlessthanorequalto0.95duetotheeffectofthedissolvedboron.Inaddition,paragraph2.3oftheSERrelatedtoAmendment118and104forCookNuclearPlantUnits1and2,respectively,statesthat"thereactivityreductionduetotherequiredpoolborationof2400ppmofboronmorethanoffsetsthe e'~0 Attachment2toAEP:NRC:1071NPage5potentialreactivityincreasesfrompostulatedfuelmishandlingaccidents."ItisconcludedthattheproposedT/Sschangesshouldnotinvolveasignificantreductioninamarginofsafety.Lastly,wenotethattheCommissionhasprovidedguidanceconcerningthedeterminationofsignificanthazardsbyprovidingcertainexamples(48FR14870)ofamendmentsconsiderednotlikelytoinvolvesignificanthazardsconsideration.Thesixthoftheseexamplesreferstochangeswhichmayresultinsomeincreaseintheprobabilityofoccurrenceorintheconsequencesofapreviouslyanalyzedaccident,buttheresultsofwhicharewithinlimitsestablishedasacceptable.TheWestinghouseanalysesdemonstrateacceptableresultsfromacriticalityperspectiveusingtheacceptancecriteriaoftheNRCStandardReviewPlan.Therefore,webelievetheexamplecitedisapplicableandthattheproposedT/Sschangesdonotinvolveasignificanthazardsconsiderationasdefinedin10CFR50.92.
l ATTACHMENT3TOAEP:NRC:1071NPROPOSED,REVISEDTECHNICALSPECIFICATIONSPAGESFORDONALDC.COOKNUCLEARPLANTUNITS1AND2 C
DESIGNFEATURESInaccordancewiththecoderequirementsspecifiedinSection4.1.6ofFSAR,withallowancefornormaldegradationpursuanttotheapplicableSurveillanceRequirements,b.Forapressureof2485psig,andc.Foratemperatureof650F,exceptforthepressurizerwhichis680F.VOLUME5.4.2Thetotalcontainedvolumeofthereactorcoolantsystemis12,612+100cubicfeetatanominalTof70F.avg5.5EMERGENCYCORECOOLINGSYSTEMS5.5.1Theemergencycorecoolingsystemsaredesignedandshallbemain-tainedinaccordancewiththeoriginaldesignprovisionscontainedinSection6.2oftheFSARwithallowancefornormaldegradationpursuanttotheapplicableSurveillanceRequirements.5.6FUELSTORAGECRITICALITY-SPENTFUEL5.6.1.1Thespentfuelstorageracksaredesignedandshallbemaintainedwith:a.Akfequivalenttolessthan0.95whenfloodedwithunboratedeffwater,b.Anominal10.5inchcenter-to-centerdistancebetweenfuelassembliesplacedinthestorageracks.1.Aseparateregionwithinthespentfuelstorageracks(definedasRegion1)shallbeestablishedforstorageofWestinghousefueltypesofenrichmentsgreaterthan3.95weightpercentU-235andburnuplessthan5,550MWD/MTUinacheckerboardpatternconfigurationalternatingCategory1andCategory2fuelasshowninFigure5.6-1.WestinghouseCategory1andCategory2fueldefinitionsaregiveninFigure5.6-2.COOKNUCLEARPLANT-UNIT15-5AMENDMENTNO.
DESIGNFEATUREScont'd5.6FUELSTORAGECRITICALITY-SPENTFUELcont'd2.Aseparateregionwithinthespentfuelstorageracks,definedasRegion2,shallbeestablishedforstorageofWestinghousefuelofanenrichmentlessthanorequalto3.95weightpercentU-235oranenrichmentgreaterthan3.95weightpercentU-235butwithaburnupgreaterthanorequalto5,550MWD/MTU,andExxon/ANFfuelofanenrichmentlessthanorequalto4.23weightpercentU-235fora17x17assemblyorlessthanorequalto3.50~eightpercentU-235fora15x15assembly.3.TheboundarybetweentheRegions1and2mentionedaboveshallbesuchthatthecheckerboardpatternstoragerequirementofRegion1shallbecarriedintoRegion2byatleastonerowasshowninFigure5.6-1.5.6.1.2Fuelstoredinthespentfuelstorageracksshallhaveamaximumnominalfuelassemblyenrichmentasfollows:DescritionMaximumNominalFuelAssemblyEnrichmentWt.I2351)Westinghouse15x15STD15x15OFA4.952)Exxon/ANF15x153.503)Westinghouse17x17STD17x17OFA17x17V54.954)Exxon/ANF17x174.23CRITICALITY-NEWFUEL5.6.2.1Thenewfuelpitstorageracksaredesignedandshallbemaintainedwithanominal21inchcenter-to-centerdistancebetweennewfuelassembliessuchthatKffwillnotexceed0.98whenfuel,assembliesareplacedintheeffpitandaqueousfoammoderationisassumed.COOKNUCLEARPLANT-UNIT15-6AMENDMENTNO.
~~ctqeS DESIGNFEATUREScont'd5.6.2.2Fuelstoredinthenewfuelstorageracksshallhaveamaximumnominalfuelassemblyenrichmentasfollows:DescritionMaximumNominalFuelAssemblyEnrichmentWt.s2351)Westinghouse15x15STD15x15OFA4.552)Exxon/ANF15x153.503)Westinghouse17x17STD17x17OFA17x17V54.554)Exxon/ANF17x174.23DRAINAGE5.6.3Thespentfuelstoragepoolisdesignedandshallbemaintainedtopreventinadvertentdrainingofthepoolbelowelevation629'".CAPACITY5.6.4Thefuelstoragepoolisdesignedandshallbemaintainedwithastoragecapacitylimitedtonomorethan2050fuelassemblies.5.7SEISMICCLASSIFICATION5.7.1Thosestructures,systemsandcomponentsidentifiedasCategoryIitemsintheFSARshallbedesignedandmaintainedtotheoriginaldesignprovisionscontainedintheFSARwithallowancefornormaldegradationpursuanttotheapplicantSurveillanceRequirements.5.8METEOROLOGICALTOWERLOCATION5.8.1ThemeteorologicaltowershallbelocatedasshowninFigure5.1.1.5.9COMPONENTCYCLICORTRANSIENTLIMIT5.9.1ThecomponentsidentifiedinTable5.9-1aredesignedandshallbemaintainedwithinthecyclicortransientlimitsofTable5.9-1.COOKNUCLEARPLANT-UNIT15-7AMENDMENTNO.
~~0'll'tjl'i-14)I4 IIIIIiI,Region1to2BoundarylReonlRegion2REGZON1,CATEGORY2FUELREGZON1,CATEGORY1FUELREGZON2FUELFIGURE5.6-lDONALDC.COOKNUCLEARPLANTSCHEMATICFORSFPINTERFACEBOUNDARYBETWEENREGIONSIAND2COOKNUCLEARPLANT-UNIT15-8AMENDMENTNO.
+14l-IRegion1StorageRequirementsBurnupvs.1nitialEnrichmentIFuelAssemblyBurnup(GWD/MTU)32-,(4.95~30.45)28-24-ACCEPTABLEFORSTORAGEASCATEGORY1FUEL20-16-12-(3.95,5.55)(4.95,5.55)REQUIREDTOBESTOREDASCATEGORY2FUEL02.2(2.3,0.0)2.6.3.43.8.4.24.6InitialWestinghouseFuelEnrichmentw/oCategory1-Regionaboveandincludinglinethrough2.3w/oCategory2-RegioninlowerrightboxFIGURE5.6-2DONALDC.COOKNUCLEARPLANTSFPREGION1BURNEDFUELASSEMBLYMINIMUM.BURNUPVS.INITIALU-235ENRICHMENTCURVECOOKNUCLEARPLANT-UNIT15-9AMENDMENTNo.
~e TABLE5.9-1COMPONENTReactorCoolantSystemCOMPONENTCYCLICORTRANSIENTLIMITSCYCLICORTRANSIENTLIMIT200heatupcyclesatlessthanorequalto100F/hrand200cooldowncyclesatlessthanorequalto100F/hr(pressurizercooldownat00lessthanorequalto200F/hr).DESIGNCYCLEORTRANSIENTHeatupcycle-TfromlessthanorequaltoBOFto0greaterthanorequalto547F.Cooldowncycle-Tfromave0greaterthanorequarto547F0tolessthanorequalto200F.80lossofloadcycles.Withoutimmediateturbineorreactortrip.40cyclesoflossofoffsiteA.C.electricalpower.LossofoffsiteA.C.electricalpowersourcesupplyingtheonsiteClasslEdistributionsystem.80cyclesoflossofflowinonereactorcoolantloop.Lossofonlyonereactorcoolantpump.400reactortripcycles.100%to0%ofRATEDTHERMALPOWER.200largestepdecreasesinload.100%to5%ofRATEDTHERMALPOWERwithsteamdump.COOKNUCLEARPLANT-UNIT15-10AMENDMENTNO.
TABLE5.9-1COMPONENTCOMPONENTCYCLICORTRANSIENTLIMITSCYCLICORTRANSIENTLIMITDESIGNCYCLEORTRANSIENTReactorCoolantSystem1mainreactorcoolantpipebreak.Breakinareactorcoolantpipegreaterthan6inchesequivalentdiameter.OperatingBasisEarthquakes400cycles-20earthquakesof20cycleseach.SecondarySystem50leaktests.5hydrostaticpressuretests1steamlinebreakPressurizedto2500psiaPressurizedto3107psig.Breakinasteam,linegreaterthan5.5inchesequivalentdiameter.5hydrostaticpressuretestsPressurizedto1356psig.COOKNUCLEARPLANT-UNIT15-11AMENDMENTNO.
'\VCl VOLUME5.4.2Thetotalwaterandsteamvolumeofthereactorcoolantsystemis012,612+100cubicfeetasanominalTavgof70F.5.5METEOROLOGICALTOWERLOCATION5.5.1ThemeteorologicaltowershallbelocatedasshownonFigure5.1-1.5.6FUELSTORAGECRITICALITY-SPENTFUEL5.6.1.1Thespentfuelstorageracksaredesignedandshallbemaintainedwith:a.AKequivalenttolessthan0.95whenfloodedwithunboratedeffwater,b.Anominal10.5-inchcenter-to-centerdistancebetweenfuelassemblies,placedinthestorageracks.1.Aseparateregionwithinthespentfuelstorageracks(definedasRegion1)shallbeestablishedforstorageofWestinghousefueltypesofenrichmentgreaterthan3.95weightpercentU-235andburnuplessthan5,550MWD/MTUinacheckerboardpatternconfigurationalternatingCategory1fuelandCategory2fuelasshowninFigure5.6-1.WestinghouseCategory1andCategory2fueldefinitionsaregiveninFigure5.6-2.2.Aseparateregionwithinthespentfuelstorageracks,definedasRegi'on2,shallbeestablishedforstorageofWestinghousefuelofanenrichmentlessthanorequalto3.95weightpercentU-235oranenrichmentgreaterthan3.95weightpercentU-235butwithaburnupgreaterthanorequalto5,550MWD/MTU,andExxon/ANFfuelofanenrichmentlessthanorequalto4.23weightpercentU-235fora17x17assemblyorlessthanorequalto3.50weightpercentU-235fora15x15assembly.3.TheboundarybetweentheRegions1and2mentionedaboveshallbesuchthatthecheckerboardpatternstoragerequirementofRegion1shallbecarriedintoRegion2byatleastonerowasshowninFigure5.6-1.COOKNUCLEARPLANT-UNIT25-5AMENDMENTNO.
5.6FUELSTORAGECRITICALITY-SPENTFUELcont'd5.6.1.2Fuelstoredinthespentfuelstorageracksshallhaveamaximumnominalfuelassemblyenrichmentasfollows:DescritionMaximumNominalFuelAssemblyEnrichmentWt.82351)Westinghouse15x15STD15x15OFA4.952).Exxon/ANF15x15-,.3.503)Westinghouse17x17STD17x17OFA17x17V54.954)Exxon/ANF17x174.23CRITICALITY-NEWFUEL5.6.2.1Thenewfuelpitstorageracksaredesignedandshallbemaintainedwithanominal21inchcenter-to-centerdistancebetweennewfuelassembliessuchthatK-'fwillnotexceed0.98whenfuelassembliesareplacedineffthepitandaqueousfoammoderationisassumed.5.6.2.2Fuelstoredinthenewfuelstorageracksshallhaveamaximumnominalfuelassemblyenrichmentasfollows:DescritionMaximumNominalFuelAssemblyEnrichmentWt.%2351)Westinghouse15x15STD15x15OFA4.952)Exxon/ANF15x153.503)Westinghouse17x17STD17x17OFA17x17V54.954)Exxon/ANF17x174.23COOKNUCLEARPLANT-UNIT25-6AMENDMENTNO.
1~
DRAINAGE5.6.3Thespentfuelstoragepoolisdesignedandshallbemaintainedtopreventinadvertentdrainingofthepoolbelowelevation629'4".CAPACITY5.6.4Thespentfuelstoragepoolisdesignedandshallbemaintainedwithastoragecapacitylimitedtonomorethan2050fuelassemblies.5.7COMPONENTCYCLICORTRANSIENTLIMIT5.7.1ThecomponentsidentifiedinTable5.7-1aredesignedandshallbemaintainedwithinthecyclicortransientlimitsofTable5.7-1.COOKNUCLEARPLANT-UNIT25-7AMENDMENTNO.
/4gfr,4I lItll~gfon1to?BoQAd~IRefon2REGION1,CATEGORY2FUELREGION1,CATEGORY1FUELREGION2"UELFIGURE5.6-1DONALDC.COOKNUCLEARPLANTSCHEMATICFORSFPINTERFACEBOUNDARYBETWEENREGIONS1AND2COOKNUCLEARPLANT-UNIT25-8AMENDMENTNO.
CI Region1StorageRequirementsBurnupvs.InitialEnrichmentFuelAssemblyBurnup(GWD/MTU)32--.(4.95~30.45)28-24-ACCEPTABLEFORSTORAGEASCATEGORY1FUEL20-16-12-(3.95~5.55)(4.95,5.55)02.2(2.30.0)2.63.4REQUIREDTOBE"STOREDASCATEGORY2'UEL'.84.24.6InitialWestinghouseFuelEnrichmentw/olICategory1-Regionaboveandincludinglinethrough2.3w/oiCategory2-RegioninlowerrightboxIFIGURE5.6-2DONALDC.COOKNUCLEARPLANTSFPREGION1BURNEDFUELASSEMBLYMINIMUMBURNUPVS.INITIALU-235ENRICHMENTCURVECOOKNUCLEARPLANT-UNIT25-9AMENDMENTNO.
TABLE5.7-1COMPONENTCYCLICORTRANSIENTLIMITSCOMPONENTCYCLICORTRANSIENTLIMITDESIGNCYCLEORTRANSIENTReactorCoolantSystem200heatupcyclesatlessthanorequalto100F/hrand200cooldowncyclesatlessthanorequalto100F/hr(pressurizercooldownat00lessthanorequalto200F/hr).Heatupcycle-Tfromlessthanorequalto550Fto0greaterthanorequalto547F.Cooldowncycle-Tfromave0greaterthanorequalto547F0tolessthanorequalto200F.80lossofloadcycles.Withoutimmediateturbineorreactortrip.40cyclesoflossofoffsiteA.C.electricalpower.LossofoffsiteA.C.electricalpowersourcesupplyingtheonsiteClass1Edistributionsystem.80cyclesoflossofflowinonereactorcoolantloop.Lossofonlyonereactorcoolantpump400reactortripcycles.100%to0%ofRATEDTHERMALPOWER.200largestepdecreasesinload.100%to5%ofRATEDTHERMALPOWERwithsteamdump.COOKNUCLEARPLANT-UNIT25-10AMENDMENTNO.
TABLE5.7-1ContinuedCOMPONENTCYCLICORTRANSIENTLIMITSCOMPONENTReactorCoolantSystemCYCLICORTRANSIENTLIMIT1mainreactorcoolantpipebreak.DESIGNCYCLEORTRANSIENTBreakinareactorcoolantpipegreaterthan6inchesequivalentdiameter.OperatingBasisEarthquakes400cycles-20earthquakesof20cycleseach.SecondarySystem50leaktests.5hydrostaticpressuretests1steamlinebreakPressurizedto2500psia.Pressurizedto3107psig.Breakinasteamlinegreaterthan5.5inchesequivalentdiameter.5hydrostaticpressuretestsPressurizedto1356psig.COOKNUCLEARPLANT-UNIT25-11AMENDMENTNO.
I