[SY-B2] Symposium B-2

[SY-B2] Modelling of defect and rare gas transport properties in UO₂ from the atomic to the grain scale

^○Marjorie Bertolus, Michel Freyss, Emerson Vathonne, Emeric Bourasseau, Serge Maillard, Gérald Jomard (CEA, DEN, Département d'Etude des Combustibles, Centre de Cadarache, 13108 Saint-Paul-lez-Durance, France)

One of the challenges for the next generation of nuclear reactors is to increase significantly the efficiency in designing and qualifying innovative fuels. One way of doing this is to develop a more physically-based description of nuclear fuels to enhance the predictive capability of fuel behaviour simulation. This should enable a better selection of promising fuel systems and a reduction of the effort necessary for the design of new fuels. Basic research approaches combining multiscale modelling and separate effect experiments can bring significant insight into key phenomena involved in the evolution of nuclear fuels during their reactor life.

We will describe the multiscale modelling approach developed from the atomic to the mesoscopic scale to investigate the transport properties of defects and rare gases in nuclear fuels. We will show examples of the results obtained at atomic scale on uranium dioxide concerning the data necessary for the mesoscale models and for the interpretation of separate experiments on fuels. We will also present the application of mesoscale models, in particular cluster dynamics.