Correlating the evolution of atomic-scale microstructure with deterioration of mechanical properties in T91 steel samples from the BOR60 reactor

T91 steel is a promising candidate material for high-dose structural components in both fusion and fission nuclear reactors. However, a better understanding of how the atomic-scale microstructure evolves under the extreme temperature and irradiation conditions within the reactor and correlating this to the deterioration of mechanical properties, is still needed to predict safe operating lifetimes of the component. Many such investigations rely upon the use of ion beam irradiation as a surrogate for neutrons to facilitate a wider range of dose and temperature effects. By eliminating issues around the radioactivity, this route also enables safe handling, access to a broader range characterisation equipment and significantly reduces costs.

However, in many cases it remains unclear how well ion irradiation can actually simulate the effects of neutron irradiation, and moreover, how it can be more precisely refined to reproduce damage induced by specific reactor doses and temperatures. This project will combine the 3D atomic-scale microscopy provided by atom probe tomography with advanced micro-mechanical testing techniques to investigate the effects of irradiation exposure in a set of samples from the BOR60 fast reactor in Russia. Complementary characterisation will be undertaken on a sets of systematically dual ion beam irradiated samples to test their effectiveness to mimic the irradiation induced in the BOR-60 reactor. The research will be undertaken in collaboration with partners at the UKAEA, University of Michigan and Oak Ridge National Laboratory.

This project falls within the EPSRC Energy research area.