The fourth generation of nuclear reactors, which tends to be safer and thriftier regarding to the uranium resources is already the subject of numerous research programs through the world. The studies related to dedicated materials (fuels, cladding, waste matrices, …) then should answer to new goals linked to the use of high temperatures and pressures. In these conditions, the design of an original fuel cycle requires to answer to the issues associated to the reprocessing step (through a complete and/or selective dissolution) and to the waste management. One of the main difficulty to consider in these processes lies in the prediction of the long-term behaviour of the materials via the understanding of physico-chemical phenomena located at the solid/liquid interface with or without external constraints (mechanic, thermal, chemical, irradiative, …).
The approach built in the lab aims to establish and understand the correlations between the microstructure of a solid and its capability to be altered. The final goal is then to be able to predict and/or control the physico-chemical parameters responsible for the increase (or the decrease) of the dissolution rate. These studies are thus expected to provide some hints on both elaboration methods, control of the microstructure through sintering step and alteration processes.
Material: Ceramic matrices, combustibles, matrices for confinment
Microstructural control: light chemistry, hydrothermal synthesis, sintering (solid/solid interface)
Solid/liquid interfaces: dissolution, lixiviation, long term behavior, structural et microstructural evolution.
Front-end cycle: thermodynamics associated with uranium phases.