Analysis of the First Three Zeus Critical Experiments

The Zeus experiments have been designed to test the adequacy of ²³⁵U cross sections in the intermediate-energy range. Detailed models of the three Zeus critical experiments are developed for the MCNP Monte Carlo code, and calculated results, based on cross sections derived from ENDF/B-V and ENDF/B-VI, are presented and assessed. A series of modeling simplifications then is described that transforms the detailed representations into benchmark configurations, and the reactivity impact of each of those simplifications is assessed.