DevelopmentofaccumulatorcomputationalaidfordeterminingRCSinjectionvolume

Reactorcoolantsystem(RCS)injectionusingaccumulatorisanimportantstrategyforbothemergencyoperatingprocedure(EOP)andsevereaccidentmanagementguideline(SAMG)ofpressurizedwaterreactor(PWR)nuclearpowerplant.Onceaccumulatorinjectionstarts,theoperatorisrequestedtoclosetheaccumulatorisolationvalvetoavoidnitrogengasflowintoRCSasthewaterlevelislow.Currentaccumulatorwaterlevelindicationsystemisnotdesignedforthispurpose.Inemergencyoperatingprocedure,itreliesonthesteamgeneratorpressuretoclosetheaccumulatorisolationvalve. ThepurposeofthispaperistodevelopacomputationalaidforestimatingRCSinjectionvolumeofaccumulator.Firstofall,simpleaccumulatormodelisverifiedusingtheplantdataduringastationblackoutincidentofMaanshannuclearpowerplant.Anisentropicexpansionmodelisfoundbetterthanadiabaticexpansionmodel.Then,acomputationalaidisdevelopedbasedonthismodel.Usingthiscomputationalaid,theaccumulatorwaterlevelcanbejudgeddirectlyfromtheaccumulatorpressure.ThiscomputationalaidcanbeappliedfortypicalPWRnuclearpowerplantsinbothemergencyoperatingprocedureandsevereaccidentmanagementguideline.