MOx Powders Calculation ImprovementCriticality Calculations in the context of OECD NEA benchmark

International audienceThe use of mixed oxide (MOx) fuels in commercial Light Water Reactors is affecting the criticality-safety evaluation of fuel cycle facilities such as the fuel manufacturing process. Hence, the calculation of plutonium resonant reaction rates in intermediate spectra is still challenging for criticality-safety evaluation of current and future GEN-IV fuel cycle facilities. This paper presents the calculation from experiments keff discrepancies of seven critical configurations from the BFS/MOx experimental program with a 22% weight Pu content. Those experiments, published in the International Handbook of Criticality Safety Experiments, were specifically performed to address needs of damp MOx powders fissile media experiments. Those results as well as the keff-sensitivity coefficients to nuclear data are needed to implement a Representativity/Transposition analysis in the context of the Phase V exercise of the Expert Group on Uncertainty Analysis for Criticality Safety Assessment (EG UACSA) of the OECD NEA Working Party on Nuclear Criticality Safety (WPNCS). The criticality calculations have been performed with the continuous-energy Monte Carlo route TRIPOLI-4 of the French criticality-safety package CRISTAL V2. The keff-sensitivity coefficients to JEFF-3.1.1 cross-sections have been computed with an IFP (Iterated Fission Probability)-based method allowing a rigorous Monte Carlo calculation of cross-sections perturbations