ML17037C516

Nine Mile Point Nuclear Station, Unit 1 - Letter Submitting Analyses Which Determine Effects of Fuel Densification and Appropriate Changes to Technical Specifications for Fuel to Be Inserted During Spring 1974 Refueling

ML17037C516
Person / Time
Site:	Nine Mile Point
Issue date:	01/22/1974
From:	Raymond P D Niagara Mohawk Power Corp
To:	Ziemann D L US Atomic Energy Commission (AEC)
References
Download: ML17037C516 (32)

Text

AECDXSUTIONFORPART50DOCKETMATER(TEMPORARYFORM)CONTROLNO:FILE:8FROAA1:NiagaraMohawkPowerCorpSyracuse,N;Y.13202P.D.RaymondDATEOFDOC1-22-74DATEREC'D1-23-74LTRMEMORPTOTHERTO:D.L.ZiemannORIG3signedqCCOTHERSENTAECPDRxSENTLOCALPDRXCLASSUNCLASSXXXXPROPINFOINPUTXXXXNOCSREC'D40DOCKETNO:50-220DESCRIPTION:Ltrnotarized1-22-74,transthefollowing:PLANTNAME:NineMilePointUnit$P1ENCLOSURES:ProosedChanetoTechnicalSecifications:DensificationAnalysesandRelatedTechnicalSpecificationsChangesforType5andTypeDONOTREMOVEACKNOWLEDGED(3Orig637cysrec'd)FORACTION/INFORMATION1-23-74GCBUTLER(L)W/CopiesCLARK(L)W/CopiesGOLLER(L)W/CopiesKNIEL(L)W/CopiesSCHWENCER(L)W/CopiesSTOLZ(L)W/CopiesVASSALLO(L)'W/CopiesSCHEMEL(L)W/Copis~ZIEMANN(L)W/9CopiesDICKER(E)W/CopiesKNIGHTOH(E)"'/CopiesYOUNGBLOOD(E)W/CopiesINTERNALDISTRIBUTIONREGAN(E)W/CopiesW/CopiesW/CopiesW/CopiesAECPDR+GCFRSMP-506A~NTZING/STAFFCASEGIAMBUSSOBOYDMOORE(L)(BWR)DEYOUNG(L)(FllR)O'SKOVHOLT(L)P,COLLINSFILE&REGION(d))MORRISSTEELETECHREVIEWHENDRXESCHROEDERMACCARYKNIGHTPAWLXCKISHAOSTELLOHOUSTONNOVAKROSSXPPOLITOTEDESCOLONGLAINASBENAROYAVOLLMERDENTONGRIMESGAMMXLLKASTHERBALLARDSPANGLERENFIROMULLERDXCKERBRIGHTONYOUNGBLOODREGANPROJECTLDRHARLESSLICASSTHIGGS(L)GEARIN(L)GOULBOURNE(L)LEE(L)MAXGRET(L)SERVICE(L)SHEPPARD(E)SMITH(L)TEETS(L)WADE(E)WILLIAMS(E)WXLSON(L)A/TINDBRAITMANSALTZMANB,HURTPLANSMCDONALD~UBEw/XnputINFOC,MILESB.KINGv4.CABELL-LOCALPDROsweoN.Y.-DTXE(ABERNATHY)M-NSIC(BUCHANAN)1-ASLB(YORE/SAYRE/WOODARD/"H"ST.~6-CYSACRSMQDi}MKSENTTO1-23-74EXTERNALDISTRIBUTION(I)(2XIO).NATIONALLAB'SI-ASLBP(E/IlBldg,gm529)1-W.PENNINGTON>RmE"201GT1-CONSULTANT'SLXC~ASST'EWARK/BLUME/AGBABIANDXGGS,1-GERALDULRIKSON...ORNL1-PDR-SAN/LA/NY1-GERALDLELLOUCHEBROOKHAVENHAT.LAB1"AGMED(RuthGussman)RM-B-127,GT.1<<RD..MULLER.,F-309GT ljl~~0PhI'~

t,h'egUlatoryDocketFileNIAGARAMOHAWKPOWERCORPORATIONNIAGARA~MOHAWK300ERIEBOULEVARD,WESTSYRACUSE.N.Y.13202January22,1974Mr.DennisL.Ziemann,ChiefOperatingReactorsBranch82DirectorateofLicensingUnitedStatesAtomicEnergyCommissionWashington,D.C.20545

DearMr.Ziemann:

JAN23)974~'L'InA)EIIpn~It-iiVu~~Re:NineMilePointUnit1AECDocketNo.50-220NiagaraMohawkPowerCorporationhascommittedinitsletterofOctober15,1973tosupplyanalysestodeterminetheeffectsoffueldensi-ficationnandtheappropriatechangestoTechnicalSpecificationsforthefueltobeinsertedduringtheSpring1974refueling.Theanalyseshavebeenperformedusingthe,guidanceprovidedintheenclosuretoyourDecember5,1973letter,"ModifiedGEModelf'rFuelDensification".TheseanalysesandtheproposedTechni:calSpecificationchangesareattachedherewith.Itisanticipatedthatthesechangeswillnotlimitplantpowerlevelbelowitsfulldesignratingof1850megawattsforpowerdistributionsexpectedduringnormaloperation.TheSiteOperationsReviewCommjtteeandtheSafetyReviewand.AuditBoardconcurwiththeseproposedTelchnicalSpecificationchanges.Verytrulyyours,Viceesident-Engineering/sqAttachmentSubscribedandsworntobeforemethis~~ayofJanuary,1974.VALERIEhl.KELLYNoteryPobhcinthe'teteofNewYorkQoeliiledInOnon.Eo..No.3Cn50C729~MyCorernlrrlonfnplret"Merch30rl9rIrr'~,JANP3)ygIEENCE'UqplrQQ,~fyICII)CEERX rI

~.,,,,<<,,RegulatoryDocketFileSpecificationChangesForgoaeraa~e.nnaiadType5andType6FuelI.AnalsesofFuelDensificationEffectsThissectionpresentsresultsoftheeffectsofdensificationinthe8x8reloadfuelasdeterminedfromapplicationofthemodelsdescribedinJRefer'ence1.A.LocalPowerSpikinA'nanalysi'sofpotentiallocalpower.spikesduetoaxialgapsinafuelpelletcolumnforGeneralElectricBMR'semployinqanRx8fuellatticedesignhasbeenperformed.ThisanalysisemploysthesamemethodandbasicassumotionsthatwerereportedinReferencel.Importantasnects.'fthisanalysisarenotedasfo11ows:l.The,equationemployedtocalculatemaximumqapsizeisthatnotedinReference1:dL=~965-+0.0025)L2wheredL=maximumaxialqaolengthL=fuelcolumnlengthPi=meanvalueofmeasuredinitialplletdensity(immersion-.5X)0.0025=allowanceforirradiationinducedcladdinggrowthandaxialstraincausedbyfuel-cladmechanicalinteraction.2.Themagnitudeofthepowerspikeversusgapsizeforfuelrodsofthe8x8desiqnisshowninFigure1fornormaloperatingconditionsandFigure2forcoldzerovoidconditions.

~4 3.Thecorepowerhistogramemployedv>>asfora13.4kl</ftCmaximumdesignlinearheatgenerationrate:.seeFigure3.TheresultsfromthisanalysisareshowninFiaure4withinitialfueldensityasaparameter.Thelineshownforaninitialfueldensityof95%T.D.isconsideredtobemostrepresentativeconsideringcurrntGeneralElectricdataonmanufacturedfuelpelletdensities.ThepowersnikepenaltyshowninFigure4forseveralmeanpelletdensitiesasafunctionofaxialposition,istherequiredmarginwhichmustbemaintaineddurinqnormalooerationbetweentheactualpeakoperatingconditionandtheoeakdesignLHGR;i.e.,13.4kM/ft,Maintainingthismarginwillassure,withbetterthan95%confidence,thatnomorethanonerodwillexceedthedesiqnneakLHGRduetotherandomoccurrenceofpowerspikes-resultingfromaxialfuelcolumngans.ConsistentwithGeneralElectric'spositionondensificationpreviouslydiscussedinReference2anditssupplements,theresultsofthisanalysisareconsideredtoheaveryconservativerepresentationofthepoweroeakinqpenaltyrequiredtoaccommodate4potentialaxialfuelcolumngapsduringnormaloperatingconditionsinGeneralElectricBHR's.SincetheresultsofthepowerspikinqanalysisfornormalonerationwillbeutilizedtolimitbundlepowertoassurethattherandomoccurrenceofpowerspikeswillnotresultinexceedingthedesignpeakLHGR,itisnotbelievednecessarytoseparatelyconsiderpowersnikesintheanalysisoftransientsoraccidentswhichhaveasaninitialconditionsomeformofnormaloneration.Thecontrolroddropaccidentisuniqueintherespectthatitbeginsatthecoldcondition,andisnotaffectedbynormaloperatingpowerlevel.Further,theexistenceoffuelcolumngapscanresultinoowerspikinginthecoldcondition

duringacontrolroddropwhichshouldthusbeconsideredintheevaluationofthisaccident.Forthispurpose,aseparatepowerspikinqanalysishasbeenperformedusingthesameassumptionsasindicatedabove,butemployinaapowerspikeversusgapsizecalculatedtooccurinthecoldconditionwithzerovoWs(Figure2).Thisanalysiswasperformedforaconservativemaximumgapsizecalculatedemployingapelletaverageimmersiondensityof94.5ÃT.D.,andapositionnearthetopofthecoreinordertomaximizetheoowersnikingeffect.Thisanalysisyieldeda99Kprobabil'ityth'atanyqivenfuelrodwouldhaveapowerspikeof45K.B.CladdingCreepCollapseUsingthesameconservativebasespresentedinReferences1and2,thecriticalpressureratio;i.e.,ratioofcollapsepressuretoactualcoolantpressure,wascalculated.Figure5presentsthecladmid-walltemperatureversustimeforthe8x8reloadfuel..Nocreditistakenforinternalqaspressureduetoreleasedfissiongasorvolatiles.Theinternalpressureduetoheliumbackfillat1atmosphereduringfabricationisconsidered.Thefuelcharacteristicsforcreepcollapse'calculationsareasfollows:CladO.D.,in.CladThickness,in.0.4930.034+0:003PeakLHGR,kw/ft13.4FastFluxvlNev.n/cm2-sec4.37x1013Figure6givesthecalculatedcriticalpressureratio.Asevidencedbythecurve,thecalculatedcriticaloressureratioisalwayso1.0.C.IncreasedLinearHeatGenerationRateThefollowingexpressionwasemployedtocalculatethedecreaseinfuelcolumnlengthduetodensificationincalculationofapenaltyinlinearheatgenerationrate:~0.965-5L=2L 0~I WherehL=decreaseinfuelcolumn.lengthL=fuelcolumnlengthp;=meanvalueofmeasuredinitialpelletdensity(immersion-.5/}Thelengthreductionduetodensificationascalculatedbytheaboveequationrequiresknowledgeofthemeanimmersiondensity(p;}obtainedfromthegCdata.Acorrectionof0-.5AT.D.isappliedtoconverttheimmersiondensitytoageometricdensity.ThemeanpelletimmersiondensityforNineMilePoint18xSreloadfuelis95.29/.T.D.Thisresultsin:AL=0.965-0.9529-0.005=0.01709=0.009L22orAL=0.9XLDue=-tothermalexpansion,anSxSpelletnormallyexnandsingoinqfromthecoldtohotcondition,anamountequalto1.25forapelletat13.4kW/ft.Thisincreaseinlengthfromthecoldtohotconditionisnottakencreditforineitherdesigncalculationsorintheprocessofcorenerformanceanalysisduringreactoroperations.Thecoldpelletlengthisassumedfortheseconditions.Therefore,thedecreaseinpelletlengthduetodensificationismorethanoffsetbypelletaxialthermalexpansion.D.DecreasedPellet-CladThermalConductivitFigure7providesplotsofMaximumAveragePlanarLinearHeatGenerationRate(MAPLHGR)versusexposure,forNineMilePointSx8reloadfuel.Them(omega}curveissuitableforincorporationintotheplanttechnicalspecifications.TheLOCAanalyseswereperformedusingtheapprovedInterimAcceotanceCriteriaModelwithgapconductancevaluesascalculatedperthenewGEGAPIIImodelwithAECmodifications.(1}

REFERENCESl.Hinds,J.A.,(GeneralElectric)lettertoY.A.Hoore(USAEC),"PlantEvaluationswithGEGAPIII,"December12,1973.2."GenericDesignInformationforGeneralElectricReloadFuel",NEDO-20103;September1973.3.NEDtl-10735,Supplement6,"FuelDensificationEffectsonGeneralElectricBoilingMaterReactorFuel,"August1973.

,7.0~FIGURE18x8POWERSPIKEVERSUSGAPSIZE-NORMALOPERATION6.05.0hPp4.0(I)3.02.01.00RODRELATIONSHIP(gO2OeO2O3O5O~05gonadjacentPellet-npod59~opg~o~ongo<~9@9dyponRod8apinRogreccdg5onRod81EffectofagapinRoEffecofa9dg4onRodNEffectofa9ap01.02,03.0GAPSIZE(CM)4.05.06.0

FIGURE28x8POWERSPIKEVERSUSGAPSIZE-COLDZEROVOIDCONDITIONRODRELATIONSHIPSOlO2O4020305o~O4O~0~~0o~d>onRod1inRooggaP~"<~g.ectoRod4onRod1EffectofqapinREffectofgapvariRod5onRod]GAPSIZE(Cg)

FIGURE34.01.21.0.8.6A'.0C).2012LHGR(KH/FT=X)13140

FIGURE48x8POMERSPIKEPENALTYYSAXIALPOSITION-NORMALOPERATION1.02.03.096,095.04.04.03.094.02.095.096.056-7DISTANCEFROMBOTTOMOFCORE(FEET)81012

690FIGURE5CLADDINGAVERAGETEMPERATUREATAFUELCOLUMNAXIALGAP6806706606500640UJ63062086'j0a-6005905805705605500IRRADIATIONTIME,YEARS

4.0FIGURE6CLADCRITICALCOLLAPSEPRESSURERATIOVERSUSTIME8x8RELOADFUEL3.01.023IRRADIATIONTIME,YEARS 0

I716FIGURE7MAPLHGRVERSUSEXPOS'MAXIMUMALLOWABLETOSTAYBELOWCURRENTTECHNICALSPECIFICATIONLIMITFORLHGR0MAXIMUMALLOWABLEWITHGEGAPIIIANDAEClODIFICATIONS15~1413~12OC1005,00010,00015,00020,000AVERAGEPLANAREXPOSURE(mWd/t)25,00030,000

II.ProposedChanestoTechnicalSpecificationsChangepages37a,37b,37c,etc.asfollows:~ChaneAAddtheattachedFigure3.1.7etotheTechnicalSpecification.UndertheLimitingConditionforOperation3.1.7,addFigure3.1.7etothelistoffiguresattheendofthelastsentenceinparagrapha.~ChaneBRep'lacethenotes;totheequationinLimitingConditionsforOoeration3.1.7bwiththefollowing:"LHGRd=DesignLHGR=17.5kw/ftfor7x7fuelor13.4kw/ftfor8x8fuelQp/p)~AX=Maximumpowerspikingpenalty'0.040for7x7fuelor0.027forBx8fuel.LT=TotalCorelenath=12ft.L=Axialpositionabovebottonofcore"~ChaneCAddFigure3.1.7etothelistoffiquresinthethirdoaraaranhoftheBases3.1.7a.ReasonsforChanesA,BRCTheresultsofanalysesperformedfor8x8reloadfuelhasindicatedthatlimitsonflAPLHGRandpowersoikingoenaltiesduetodensificationarerequired.TheselimitsastheyapplytoType5andType6fuelarepresentedforincorporationintoNineNilePointUnit1TechnicalSpecifications.Similarlimitsforpreviouslyloaded7x7fuelarealreadynartof-the'echnicalSpecifications.

JIE 17NINEhflLEPOINT-PilIT116~4~14~13~12OC1005,00010,00015,00020,000AVERAGEPLANAREXPOSURE(ml<d/t)25,00030,000FIGURE'.1.7.eftAXIfGAUMALLOWABLEAVERAGEPLANARLHGRAPPLICABLETOFUELTYPE5and6 00A'l