Integratedmodularwaterreactor(IMR)designOriginalResearchArticle

Integratedmodularwaterreactor(IMR)hasbeendevelopedasoneoftheadvancedsmall-scalelightwaterreactors,withathermaloutputof1000MW.TheIMRadoptsnaturalcirculationandself-pressurizationintheprimarycoolingsystem,andareactorvesselbuilt-insteamgenerators.Thecoredesignhasbeenperformedusingthecurrentlightwaterreactortechnology.Thermal-hydraulicsensitivityanalyseshavebeendonefromtheviewpointofthedeparturefromnucleateboiling(DNB)limitation.TheIMRcore,with9721×21-typefuelassembliesandnaturalcirculationintheprimarycoolantsystem,showsagoodnuclearandthermal-hydraulicbehaviorandgoodallowablemarginsfortheDNBphenomenon.Thereactivitychangewithburnupisabout1%Δkbyusingburnableabsorbers,andonly12rod-cluster-controlsareusedthroughtheoperatingcycle.The20m-heightreactorvesselenclosessteamgeneratorsinvaporandliquidportions.PlantdynamicanalyseshavebeenalsoperformedinordertoevaluatetheIMRbehaviorfromtheviewpointsofplantoperationandcontrol.ThisstudyshowsthattheIMRwilloperatewithenoughmarginsforthecoresafetyandwillbestablycontrolledforloaddemandchangesexpectedduringnormaloperations.