ML19246B716

Meeting Between NRC and Exelon Regarding Calvert Cliffs-2 LAR to Use Framatome ATF LTAs

ML19246B716
Person / Time
Site:	Calvert Cliffs
Issue date:	08/29/2019
From:	Gassmann B Exelon Generation Co, Exelon Nuclear
To:	Office of Nuclear Reactor Regulation
Marshall M, NRR/DORL/LPLI, 415-2871
References
EPID L-2019-LRM-0031
Download: ML19246B716 (7)

Text

1 MeetingBetweenNRCandExelonRegarding CalvertCliffs2LARtoUseFramatomeATF LTAs BillGassmann ExelonNuclear August29,2019 NonProprietary Agenda

• Background

• GeneralInformationonLeadTestAssemblies(LTAs)

• FramatomePROtectTM ATF

• LicensingActions

• TechnicalEvaluationSummary

• Summary 2

2 Background

• ExelonhastakenaleadershiproleintheU.S.DOE programtodevelopLWRfuelswithenhancedaccident tolerance

• ExelonhasloadedAccidentTolerantFuel(ATF)Lead TestAssemblies(LTAs)atByron2inApril2019,andwill loadATFLTAsatClintoninSeptember2019

• ExelonplanstoloadtwofullFramatomeLTAsatCalvert Cliffs2inMarch2021tobeoperatedinCycles24 through26 3

CalvertCliffs2ATFLTAs LTAsarebasedontheAdvancedCE14x14HTP/HMPFramatomefueldesign AllfuelrodswillutilizeChromiumcoatedM5cladding FuelpelletswillbeChromiaenhanced,exceptfor BlanketUO2 pellets Gadolinia(UO2Gd2O3)fuelpellets LTAswillbeplacedinnonrodded,noninstrumentedlocations Togainvaluabledata,theLTApowerreductionwillbelimitedto2%lowerin peakpinpowerthanthepeakpinpowerofthecoresidentfuelthroughout eachcycle ThisisthefirstdeploymentoffullATFLTAs 4

3 FramatomePROtectTM ATF 5

CalvertCliffs2ATFLTAs

• ThecurrentNRCapprovedFramatomefueldesignandreload analysismethodsarenotfullyapplicabletotheLTAfueldesign andmaterials Analyticalcodesandmethodswillbemodifiedasnecessary usingconservativeassumptionsandqualitativeassessments ExelonplanstoapplyforaLicenseAmendmentunder 10CFR50.90inordertoimplementthisproposedactivity LARcontentwillbesimilartotheByron2ATFLARandwill containadescriptionoftheapproachesplannedand analyticalexpectations 6

4 LicensingActions TechnicalSpecification2.1.1.2.a Peakfuelcenterlinetemperature InMODES1and2,thepeakfuelcenterlinetemperatureshallbemaintainedat lessthan5081F,decreasingby58Fper10,000MWD/MTUandadjustedfor burnablepoisonperXNNF7956(P)(A),Revision1,Supplement1.

• Chromiaintroductiondecreasesmelttemperature;asaresult,thisTechSpec temperaturelimitwillbecomenonconservativeforChromiaenhancedUO2 fuelpellets

• ExelonwillrevisethisTStoaddthecenterlinetemperaturelimitapplicableto theLTAs ExelonwillalsorequestanadministrativechangetothisTStochangetheword AREVAtoFramatome 7

LicensingActions TechnicalSpecification4.2.1 LTAswillbeloadedincorelocationswhichmaybelimitingundercertain conditionsasdiscussedlaterintheseslides

• ExelonwillrequestanadditiontothisTStodescribeLTA compliance/exceptionstothenonlimitingrequirement LicenseConditionforrodinternalpressureshallremainbelowthesteady statesystempressure ExelonwillrequestanexemptionfromthecurrentAppendixCLicense ConditiononinternalrodpressurefortheLTAs 10CFR50.46Exemption Exelonwillcomplywiththerequirementsof10CFR50.46 8

5 FramatomePROtectTM ATF

• Thethermal,physical,andchemicalpropertiesofthefuelpellets aresufficientlyunderstoodtogiveahighlevelofconfidencein thesafetyoftheproposedactivity

• Themechanical,material,andchemicalpropertiesofthecoated cladaresufficientlyunderstoodtogiveahighlevelofconfidence inthesafetyoftheproposedactivity

• Framatomepreviouslymanufacturedsimilarpelletsandsimilar coatedcladdingthatiscurrentlyinoperationinsometestrods atVogtle.ThemaindifferencebetweentheVogtleandCalvert CliffsprogramsisthatCalvertCliffswillusefullassembliesofATF PROtectTM fuelrods 9

TechnicalEvaluation FuelRodThermalMechanicalDesign

• RODEX2istypicallyusedforCalvertCliffsfuelperformance analyses.COPERNICwaspreviouslymodifiedforLTAswith Chromiaenhancedfueltoproperlymodelthethermal mechanicalbehavioroftheChromiaenhancedfuelpelletsand willbeusedfortheCalvertCliffsLTAs

• TheChromiumcoatedcladdingwillbeexplicitlyaddressedfor eachthermalmechanicalanalysisusingconservative assumptions,andquantitativeassessmentswhenapplicable

• Evaluationoffuelcenterlinemeltandtransientcladdingstrain duringAOOswillutilizeaCOPERNICbasedmethodadapted fromexistingNRCapprovedmethods

• LARwilladdressCOPERNICapprovalforthisCalvertCliffs2 application 10

6 TechnicalEvaluation FuelAssemblyDesign

• Themostsignificantaffectedareaswillbeevaluated,andno adversemechanicaldesignimpactsareanticipated Fuelrodinteractionwithassemblysubcomponents Nochangetofuelassemblysubcomponents,exceptforfuel rods Fuelassemblyweight Spacersorgridtorodfretting Fuelhandlingequipment Fuelshipping,handling,andstorage Lostpartsanalysis 11 LossofCoolantAccidents Thereisapotentialthat,forthesamesystemresponseasthecurrentLOCA licensingbasis,arodintheLTA(withonlya2%peakpinpowerreduction) couldhaveahigherreportedPCTthanastandardfuelrod TheCalvertCliffsplantandECCSdesignresultsinreportedPCTsforthe standardfuelproductthatarebelowthepointofsignificantmetalwater reaction,whichistheprimaryLOCAbenefitfromcoatedcladding Achangeinaproductinherentlychangessomepropertiesinbeneficialways andothersindetrimentalways Slightdetrimentstoproperties,suchasreducedemissivityandreducedfuel thermalconductivity,cannotbeoffsetduethisplantslowLOCAtemperature regime Additionally,theuncertaintyintheLTApropertiesmustbeboundedandthat willalsocontributetohigherreportedLOCAresults 12

7 CoreLoadingPattern

• TheLTAswillbeplacedincorelocationswheresufficientduty anddatacanbeobtainedtoadvancetheFramatomeATF program

• TheLTAswillbeatleast2%lowerinpeakpinpowerthanthe peakpinpowerofthecoresidentfuelthroughouteachcycle

• Theselectionof2%isconsistentwiththerecentNRCapprovalof theByron2ATFLTAprogram 13 Summary

• ExelondesirestoinserttwoPROtectTM LTAsinCalvertCliffs2 duringtheMarch2021refuelingoutage

• LicensingActionsneeded TechSpec2.1.1.2.awillbecomenonconservativefor ChromiaenhancedUO2fuelpellets TechSpec4.2.1 LTAsmaybelimitingundercertain conditions LicenseConditiononrodinternalpressure(COPERNIC)

• Exelonwillcomplywiththerequirementsof10CFR50.46

• CurrentgoalisLARsubmittalinearly4th quarter2019 14