NuFuel & MMSNF 2015

First Workshop on Research into Nuclear Fuel in Europe
and Materials Modeling and Simulation for Nuclear Fuels Workshop
Karlsruhe, Germany, November 16th to 18th, 2015

Updated: Tue 08 Dec 2015, 14:27

Talk 5.2: Mechanical behaviour of UO2 under irradiation: a molecular dynamics study

Laurent Van Brutzel, A. Chartier
  • CEA, DEN, DPC/SCCME, Centre de Saclay, 91191 Gif-sur-Yvettre, France
  • E-mail: laurent.vanbrutzel@cea.fr

Abstract

Mechanical properties of nuclear fuel are a complex problem, involving many coupled mechanisms occurring at different length scales. Most of our knowledge regarding this mechanical behaviour is obtained by experiments on unirradiated fuel, or post-mortem analysis on spent fuel. Atomistic models can alternatively provide insight on the behaviour of the fuel in conditions inaccessible to current experiments, which are used as input parameter for models at larger length-scales. The present investigation considers recent studies on the evolution of the mechanical properties of UO2 after irradiation damage by means of atomistic simulations with molecular dynamics method using empirical potentials.

Firstly, we will describe the mechanical behaviour under tensile and compressive load in pristine UO2 single-crystal. Secondly, mechanical properties and crack propagation mode will be investigated in large UO2 single-crystal including point defects distribution arising from irradiation events. The influence of the crystallographic orientations, temperature, and dose will be discussed.

Finally, we will present the influence of gas fission nanobubble distribution in the UO2 matrix on the mechanical properties.