Interpretation of fission product release observed in VERCORS tests with MFPR computation code
Résumé
This document aims to present the current interpretation of fission product release during VERCORS tests. Release kinetics of Cs, Mo, Ba, Ru and I are deeply analyzed on the basis of several hypotheses mainly laying on thermochemistry considerations. It is shown that the fuel characterization at the end of irradiation, especially concerning the chemical speciation and localization of fission products, is of first importance. Elsewhere, a coupling
between chemically active fission product release and gas release mechanism is to be considered. Finally, a global
interpretation scheme aiming to unify a microscopic interpretation to a macroscopic one is displayed with an adaptation to various cases, namely MOX and high-burnup fuels.