ExperimentalverificationofthefastreactorsafetyanalysiscodeSIMMER-IIIfortransientbubblebehaviorwithcondensationOriginalResearchArticle

Experimentalverificationofareactorsafetyanalysiscode,SIMMER-III,wasundertakenfortransientbehaviorsoflarge-scalebubbleswithcondensation.Thepresentstudyaimedtoverifythecodefornumericalsimulationsofrelativelyshort-time-scalemulti-phase,multi-componenthydraulicproblems.Amongthese,vaporizationandcondensation,orsimultaneousheatandmasstransfer,playimportantroles.Inthisstudy,aseriesoftransientbubblebehaviorexperimentsdedicatedtocondensationphenomenawithnoncondensablegaseswascarriedout.Intheexperiments,apressurizedmixtureofnoncondensablegasandsteamwasdischargedasalarge-scalesinglebubbleintoacylindricalpoolfilledwithstagnantsubcooledwater.Theconcentrationofnoncondensablegaswastakenasanexperimentalparameteraswasthespeciesofnoncondensablegas.Thecharacteristicsoftransientbehavioroflarge-scalebubbleswithcondensationobservedintheexperimentswereestimatedthroughexperimentalanalysesusingSIMMER-III.Intheexperimentswithsteamcondensation,dispersionofthegasmixturedischargedintotheliquidpoolwasaccompaniedbyvaporcondensationatthebubblesurface.SIMMER-IIIsimulationssuggestedthatthenoncondensablegashadalessinhibitingeffectonthecondensationoflarge-scalebubbles.Thisisadifferentcharacteristictothatofthequasi-steadycondensationofsmall-scalebubblesobservedinourpreviousexperiments.