Neutron activation and dose rates minimization in Laser Megajoule (LMJ) facility

The Laser Megajoule (LMJ) facility, dedicated to inertial confinement fusion experiments, is under construction at CEA center near Bordeaux since summer 2003. Operation with hundred micrograms of deuterium–tritium will generate high 14 MeV neutron yields that will induce high neutron activation and high doses rates levels in the target chamber area. us calculations [Ph. Joyer, M. Dupont, H.P. Jacquet, Safety issues on Laser Megajoule (LMJ) facility, Nucl. Eng. Des. (2003)] have shown relatively high doses rates and the need to reduce activation in the experimental bay. Paths of activation and doses rates reduction were identified. The present paper gives the last results obtained.