Multi-Scale Modelling of Defects in Austenitic Steels

The in-core components of light water reactors surround the fuel elements and ensure their positioning and cooling, by supporting them and guiding the coolant ow. They are exposed to intense neutron irradiation, mechanical and thermal stresses and the corrosive action of the high temperature water coolant. This exposure may lead to several degradation mechanisms, limiting the useful life time of the in-core components. Although these components, differently from the reactor pressure vessel, can be replaced, a deeper fundamental understanding of these degradation mechanisms is desirable in order to minimize costly replacement campaigns. In this work an atomistic study regarding the stacking fault energy and dislocation behaviour in austenitic binary model alloys is performed. Such simulations contribute to a better understanding to the mechanisms governing hardening and embrittlement in such steels.