Analyticaltooldevelopmentforcoarsebreak-upofamoltenjetinadeepwaterpoolOriginalResearchArticle

AcomputercodeJASMINE-prewasdevelopedforthepredictionofpremixingconditionsoffuel–coolantinteractionsanddebrisbedformationbehaviorrelevanttosevereaccidentsoflightwaterreactors.InJASMINE-precode,ameltmodelwhichconsistsofthreecomponentsofsub-modelsformeltjet,meltparticlesandmeltpool,iscoupledwithatwo-phaseflowmodelderivedfromACE-3DcodedevelopedatJAERI.Themeltjetandmeltpoolmodelsareone-dimensionalrepresentationsofamoltencorestreamfallingintoawaterpoolandacontinuousmeltbodyagglomeratedonthebottom,respectively.Themeltparticlesgeneratedbythemeltjetbreak-uparemodeledbasedonaLagrangiangroupedparticleconcept.Additionally,asimplifiedmodelpmjetwasdevelopedwhichconsidersonlysteadystatebreak-upofthemeltjet,coolingandsettlementofparticlesinastationarywaterpool.TheFAROcoriumquenchingexperimentswithasaturationtemperaturewaterpoolandasubcooledwaterpoolweresimulatedwithJASMINE-preandpmjet.JASMINE-prereproducedthepressurizationandfragmentationbehaviorobservedintheexperimentswithareasonableaccuracy.Also,theinfluencesofmodelparametersonthepressurizationandfragmentationwereexamined.Thecalculationresultsshowedaquasi-steadystatephaseofmeltjetbreak-upduringwhichtheamountofmoltenmasscontainedinthepremixturewaskeptalmostconstant,andthesteadystatemoltenpremixedmassesevaluatedbyJASMINE-preandpmjetagreedwell.