ExperimentalinvestigationofcoriumquenchingatelevatedpressureOriginalResearchArticle

Thispaperdescribestheresultsofexperimentsdesignedtoquantifythecoolingrateofcoriumbyanoverlyingwaterpool.Theexperimentsareintendedtoprovidefundamentalinformationontheabilityofwatertoingressintocracksandfissuresthatforminthedebrisduringquench,therebyaugmentingtheotherwiseconduction-limitedheattransferprocess.Thisinformationisbeingusedtoassesstheeffectivenessofawaterpoolinthermallystabilizingamolten-core/concreteinteractionandcoolingofex-vesselcoredebris.Theexperimentsinvolvedcoriuminventoriesof75kgwithameltdepthof15cmanddiameterof30cm.ThecoriumwascomposedofUO2/ZrO2/concretetosimulatemixturesofmoltenreactorcorecomponentsandeithersiliceousorlimestone/commonsand(LCS)concrete.Initialmelttemperatureswereoftheorderof2100°C.Theheattransferratefromthecoriumwasdeterminedthroughmeasurementsofthevaporproductionratefromthewaterpool.Themeltwasquenchedatatmosphericpressureforthefirsttwotestsandat4barforthetwosubsequenttests.Preliminarydataanalysisindicatesthattheoverallheattransferrateexceededtheconduction-limitedrateforthethreemeltscontaining8wt.%concrete,butnotforthefourth,whichhad23wt.%concrete.Also,thequenchrateofthe8wt.%concretemeltsdidnotvaryappreciablywithpressure.