Combination of multiscale and thermo-dynamic modelling, SEE and post-irradiation examinations

Coordinated by Thierry Wiss, JRC-ITU (EU)

The objective of this WP is to make the synthesis of the basic research investigations performed in WP1 to 4 and combine them with results obtained on neutron‐irradiated fuel to get further insight on three of the operational issues considered in INSPYRE: self‐diffusion, behaviour of fission gases and mechanical properties.
Task 5.1 includes high quality diffusion couple experiments and the development of a full thermo‐kinetic model to determine the diffusion constants for U, Pu and O in MOX fuels and to greatly reduce the uncertainty margins in current literature data.
Task 5.2 uses advanced microscopic techniques on irradiated fuels and the combination with the results of the separate effect studies performed in WP2 to determine the models underpinning the laws related to the behaviour of fission gases during irradiation, which give rise to swelling and release.
Tasks 5.3 will pivot on the experimental results obtained in WP 3 to derive and improve models for incorporation in fuel performance codes of WP6. It aims at elucidating the different creep mechanisms (thermal, ion and neutron irradiation) in UO2 and MOX.