Inter-subassemblyheattransferofsodiumcooledfastreactors:ValidationoftheNETFLOWcodeOriginalResearchArticle

ThispaperdescribesthepredictionoftemperatureattheexitofsubassembliesofasodiumcooledfastreactorusingtheNETFLOWcode.Untilpresenttime,thisplantdynamicscalculationcodeisexpectedasatoolofnucleareducation,andhasbeenvalidatedusingdataobtainedatfacilitiesorreactorscooledwithwaterorsodium.Anaturalcirculationtestwasconductedintheexperimentalfastreactor‘Joyo’witha100MWirradiationcore.Alsoaturbinetriptestwasconductedintheprototypefastbreederreactor‘Monju’.Thesetestswerechosentovalidateamodeltocalculateinter-subassemblyheattransferconsistingofheatconductionandheattransferbyinter-wrapperflow.Basedonthecalculationforthenaturalcirculationtestinprimaryandsecondaryloopsof‘Joyo’,themodeltocalculatetheheattransferinradialdirectionoftheinter-subassembliessimulatedreasonablesodiumtemperaturebehaviorsattheexitofsubassemblies.Goodagreementwasalsoobtainedinpredictionoftemperaturesattheexitofthe‘Monju’subassemblies.Throughthesevalidations,itwasshownthattheone-dimensionalplantdynamicscodeNETFLOWcouldtracetemperaturesattheexitofthesubassembliesoffastreactorswiththeinter-subassemblyheattransfermodel.