An atomistic modelling of the porosity impact on UO2 matrix macroscopic properties

Abstract The porosity impact on the UO 2 matrix thermomechanical properties was investigated using atomistic simulation techniques. The porosity modifies the thermal expansion coefficient and this is attributed to pore surface effects. The elastic moduli at 0 K and at finite temperature decrease with porosity, this variation being well approximated using affine functions. These results agree with other mesoscale model predictions and experimental data, showing the ability of the semiempirical potential atomistic simulations to give an overall good description of the porous UO 2 . However, the surface effects are incompletely described.