VALMOX: Validation of Nuclear Data for High Burn-up MOX Fuels

VALMOX is one of the projects of the cluster EVOL (Evolutionary Fuel Concepts: High Burn-up and MOX Fuels), which is part of the research programme on Nuclear Energy, Safety of the Existing Installations. Four companies are engaged in this work. Entirely devoted to MOX assemblies in Light Water Reactors, VALMOX comprises the evaluation of the actinide and fission product inventory of MOX fuel at high burn-up (typically 60 GWd/t), with special attention to the helium production. Calculated values for the spent fuel isotopic masses are to be compared to the measured ones, with sensitivity analyses made in support. JEF-2.2 nuclear data is taken as a basis for the calculations. The resulting recommendations on nuclear data should be employed in the preparation and testing of the next JEFF-3.1 file. The VALMOX work is based on the best available analyses of spent, commercial MOX fuel, for burn-up of 60 GWd/t and higher. It includes MOX irradiations data from Saint-Laurent-des-Eaux and Dampierre (CEA) and data from the ARIANE programme (BN and SCK-CEN). SCK-CEN is responsible for the MC calculation of the ARIANE irradiation experiments which took place from 1990 to 1996 in the 400-MWe PWR of Beznau-1