(1) OECD/NEA KRITZ-2 UO2 AND MOX BENCHMARKS

The international Expert Group on Reactor-Based Plutonium Disposition (TFRPD) has been established at the OECD/NEA to facilitate the sharing of existing information and experience in the physics and fuel behavior of MOX fuel as it relates to the disposition of weapons-grade plutonium. One of the many recent activities of this Experts Group is the analysis of several critical configurations of the KRITZ reactor. In total, three core configurations were considered, two with UO2 fuel and one with MOX fuel. Measurements were performed for room temperature as well as elevated temperatures (~245°C). Solutions were obtained from several participants using both deterministic and Monte Carlo methods. The calculational results generally show a slight negative bias in k eff of about 0.2 – 0.6 % for the UO2 configurations and about 0.1 % for the MOX core. The relative fission rate results generally lie within a band of ±2 % for all cases with maximum errors approaching 4 – 6%. 1