Development of an Isotopic Depletion Method for Reactor Core Calculations

Abstract

We will discuss in details two methods which can be used to generate the properties of the pseudo-actinides (pseudo-isotopes) for simplified 235U and 238U depletion chains. Using physical considerations, we derive relations for the time and space dependence of the cross sections, decay constants and fission yields for the pseudo-isotopes. The effect of the creation of these pseudo-actinides on the criticality of a thermal power reactor is investigated.