Burnup Credit Implementation for PWR UOX Used Fuel Assemblies in France: From Study to Practical Experience

AbstractBurnup credit for used fuel assemblies, in particular, pressurized water reactor uranium oxide, has been a major focus of research in France for more than 30 years. As a result, a wealth of knowledge and experience has been gained. The first implementation of burnup credit in France used the “50-leastirradiated-cm” method approved by the French safety authority in the early 1980s. However, because of the continuous increase in fuel enrichment, the industry is interested in reducing the conservatisms of this method by taking into consideration more realistic hypotheses, such as the introduction of fission products and a nonuniform axial burnup profile. To address this concern, a working group, bringing together several French nuclear companies and institutions [AREVA, CEA (Commissariat a l’Energie Atomique et aux Energies Alternatives), EDF (Electricite de France), and IRSN (Institut de Radioprotection et de Surete Nucleaire)], was created in 1997. This paper presents the results of the working gro...