A. Alamo, Commissariat a l‘ Energie Atomique, Gif sur Yvette (France)
The development and qualification of structural materials have been recognized as a crucial issue to ensure the
safe and reliable operation of advanced nuclear energy reactors. The design of these advanced systems looks
forward to longer lifetimes, higher in-service and off-normal temperatures and improved resistance to radiation
damage. These requirements are a real challenge for the development of structural materials, in particular for
those destined to heavily irradiated core components where very severe in-service conditions are foreseen.
Several types of materials are investigated at the present time. For the core structures, the main candidates are
the high Chromium steels, of the 9-12%Cr type, as well as some advanced materials like the Oxide Dispersion
Strengthened (ODS) Fe-Cr based alloys. Available data related to the evolution of the microstructure and the
mechanical behaviour under neutron irradiation will be discussed for these materials.