Study of irradiation effects in China low activation martensitic steel CLAM

Abstract Reduced activation ferritic/martensitic steels (RAFM steels) are presently considered as the primary structural materials for a demonstration (DEMO) fusion plant and the first fusion power reactors because of their attractive properties. Studies on various properties of China low activation martensitic steel (CLAM) are underway. The activation level of CLAM steel was calculated with the widely used inventory code FISPACT with the latest data library FENDL/A-2 based on the first wall (FW) neutron spectrum of the fusion-driven subcritical system (FDS) from the Monte Carlo transport code MCNP/4C calculation with FENDL-2 data library. The results were compared with the activation levels of other RAFM steels, such as EUROFER97, F82H, JLF-1 and 9Cr–2WVTa etc., under the same irradiation conditions. Furthermore, the dominant nuclides to γ-ray dose rate of CLAM steel were analyzed. The required control levels of impurities in CLAM steel will soon be implemented based on the hands-on and remote recycling dose rate limits.