State of the art of fuel micro-mechanical modelling: From atomic scale to engineering laws in fuel performance codes

International audienceThis paper presents the state-of-the-art knowledge about the micro-mechanical modelling of the fuel behavior under irradiation with normal and off normal operating conditions. Modelling of fundamental processes can provide key insights in the behavior of the material. Such models target specific phenomena due to the limits of computational resources and scope of theory, necessitating a multiscale approach. This work follows a multiscale paradigm building up in spatio-temporal scale. The micro-mechanical modelling studied addresses all the loading conditions encountered in the reactor with elasticity, plasticity, creep and fracture behavior. Atomistic-scale modelling review reveals mechanisms and physical parameters for elasticity of fresh and irradiated fuel, rupture, dislocation gliding and internal stresses induced by pressurized bubble with fission gases. Simulation techniques proposed at this scale are Density Functional Theory, Molecular Dynamic with empirical potential, Dislocation Dynamics and Phase Field Crystal methodology