WWER fuel rod isotopics by MONTEBURNS 1.0 - Influence on the multiplication factor and comparison with the CB3 benchmark data

Burnup credit has taken a great importance during the last years. Hence, a special effort for improving the reliability of current burnup codes and cross-section libraries has been necessary in order to simulate as accurately as possible the behavior of the irradiated fuel in nuclear power plants and/or storage and transport facilities. The aim of the work performed at SEA is to compare the new code MONTEBURNS, developed in Los Alamos Laboratory, with ORIGEN-S for the WWER fuel rod isotopics calculation in an infinite array. MONTEBURNS links the Monte Carlo transport code MCNP with the radioactive decay and burnup code ORIGEN-2.1. The results obtained show that MONTEBURNS may become in the future a very important tool for isotopic studies, though its accuracy depends on the quality of the cross-sections used. (author)