The NEA Expert Group on Multi-scale Modelling Methods (EGM3) aims to provide the global nuclear energy community with an overview of fuels and structural materials models and computer simulation methods of interest at different length and time scales for the description of materials behaviour. The integration of these models provides a logical path to develop predictive understandings of the performance of materials used in the current fleet of nuclear reactors and to design new materials for advanced fission and fusion reactors.
The EGM3 recently published a report presenting a state-of-the-art review of physical multi-scale models rooted in computational physics. The report describes the properties and behaviour of materials of interest for the nuclear community. It also includes an overview of the methods, along with the possibilities and limits of linking different scales. There is considerable potential to link scales by passing relevant parameters from the lower scale or by providing microstructural information from a higher scale to lower scale models. Such multi-scale modelling can overcome the limitations imposed by the current use of empirical models in computer codes, and enable predictive understanding of materials used in nuclear reactors.