Experimental and numerical study of fracture mechanisms in UO2 nuclear fuel

In this paper we study the brittle behavior of UO2 nuclear fuel. Firstly, we present the interpretation of bending tests with three different approaches to assess rupture parameters (critical stress and surface energy). Secondly, we present Vickers’ indentation tests on fresh UO2 fuel. The comparison between bending and indentation tests on fresh fuel allows us to assess the parameters necessary to derive the critical stress and the surface energy from indentation tests. Vickers’ indentation is then used to evaluate rupture parameters of irradiated fuels. At the end, we present some applications to fuel rod modeling taking into account the different rupture mechanisms.