Benchmarking CAPRIX pin behaviour under irradiation with high plutonium content: comparison with experimental data

This paper presents the results of the second phase of the benchmark exercise in the Plutonium Management for More Agility project (PuMMA), which aims to enhance the reliability of fuel performance codes (FPCs) for Mixed Oxide (MOX) fuels with high plutonium content. This phase involved the simulation of the CAPRIX irradiation (45% of Pu) carried out in the PHENIX reactor in France. Thirteen organizations from nine countries participated, using eight different fuel performance codes. In this phase, 7 codes then improved its modelling by optimizing parameters and/or improving the formulation of some models involved in the computation. A comparative analysis was then conducted between the codes and the post-irradiation experimental (PIE) results, with the objective of identifying the improvements made, the discrepancies still observed, and to define future areas for improvement and development. The present paper demonstrates the results for the CAPRIX pin. The main results despite the discrepancies noted between the codes and/or with the experimental data, the work carried out through this benchmark has demonstrated the capacity of the codes to optimise/improve their simulation in order to approximate the PIE. Moreover, the methodology employed yielded a comprehensive and precise analysis, thus facilitating the suggestion of approaches to the development of specific models. This finding thus demonstrates the potential of fuel performance codes modelling pins with high Pu contents.