Towards a new approach for structural materials of Lead Fast Reactors

The development of Pb and LBE cooled fast reactors represents a unique challenge for the materials that are subject, at the same time, to degradation mechanisms related to neutron radiation damage, exposure to high temperatures and exposure to the HLM. The protection towards HLM corrosion, in the past, has been based on the control of the oxygen concentration in the HLM by keeping high oxygen concentration in the liquid metal and prevent the onset of severe oxidation. The proposed approach bases the protection of structural materials on oxides more stable than chromium oxide in HLM; namely alumina. Two paths are under study to perform stable oxides protections on LFR structures: 1) steel coating by anti-corrosion barriers, 2) alumina forming austenitics based on the optimization of composition to improve the resistance to irradiation swelling and maintain suitable mechanical properties.