Influence of chromium addition in UO2 nuclear fuel on cesium speciation in case of severe accident

Cr-doped UO2 nuclear fuel (E-ATF) is studied for its improved behaviour in case of accident. Nevertheless, experimental data are necessary to understand the influence of Cr addition on fission products behaviour in case of severe accident. Indeed, chromium is likely to react with some fission products and form volatile species that will not be found in an undoped UO2 fuel. In this proposal, we propose to study cesium speciation in a Cr-doped UO2 simulated fuel after thermal treatments with thermodynamic conditions representative of a severe accident. The XAS results acquired on FAME-UHD (BM16) beamline will allow us i) to understand the influence of chromium doping on the speciation of cesium in UO2 fuel in different thermodynamic conditions, ii) to complete the knowledge on the U-Cr-Cs-O quaternary system.