Noblegasbinarymixturesforgas-cooledreactorpowerplantsOriginalResearchArticle

ThispaperexaminestheeffectsofusingnoblegasesandbinarymixturesasreactorcoolantsanddirectclosedBraytoncycle(CBC)workingfluidsontheperformanceofterrestrialnuclearpowerplantsandthesizeoftheturbo-machines.Whilepureheliumhasthebesttransportpropertiesandlowestpumpingpowerrequirementofallnoblegasesandbinarymixtures,itslowmolecularweightincreasesthenumberofstagesoftheturbo-machines.TheheattransfercoefficientforaHe–Xebinarymixturehavingamolecularweightof15g/moleis7%higherthanthatofhelium,andthenumberofstagesintheturbo-machinesis24–30%ofthoseforHeworkingfluid.However,forthesamepipingandheatexchangecomponentsdesign,thelooppressurelosseswithHe–Xeare∼3timesthosewithHe.Consequently,forthesamereactorexittemperatureandpressurelossesinpipingandheatexchangecomponents,thehigherpressurelossesinthenuclearreactordecreasethenetpeakefficiencyoftheplantwithHe–Xeworkingfluid(15g/mole)byalittlemorethan∼2%points,athighercyclecompressionratiothanwithHeworkingfluid.