Anefficientanalyticalformfortheperiod-reactivityrelationofberylliumandheavy-watermoderatedreactorsOriginalResearchArticle

Anewmathematicalformoftheperiod-reactivityequationforheavy-water-andberyllium-moderatedreactorshasbeendeveloped.ThisformisrepresentedinapolynomialformwithadegreeofG+1forG-thgroupofdelayedneutronsandphotoneutrons.Ageneralformulaforthecoefficientsofsuchpolynomialisderived.Thesecoefficientshavealineardependenceonthestepreactivityinsertion.Therelatedconstantsofthislineardependencearecalculatedforbothtypesofreactors.Inaddition,acomparisonhasbeenmadeforthestablereactorperiodsofaninfiniteU235-fueled,D2O-orBe-moderatedreactors,followingstepreactivityinsertion,withandwithoutdelayedphotoneutronstakenintoconsideration.Also,acomparisonwasmadeforthereactorresponsetoreactivitychangeswhenevaluatedusingfastandthermalfissiondelayedneutrongroupconstantscombinedwithandwithoutD2O-andBe-moderatedreactors.