First IFMIF/EVEDA Radioprotection Studies for the Preliminary Design of the Accelerator Beam Dump

A preliminary beam dump cartridge design has been proposed recently for the IFMIF-EVEDA accelerator. Copper was the material chosen for the beam stop. In this paper we investigate the possibility of designing a practical shielding for the proposed cartridge so that it can offer an acceptable radioprotection response during both beam-on and beam-off phases. The radioprotection analysis is performed for the whole beam dump component located inside the already designed accelerator vault. A comprehensive methodology has been proposed to deal with the problem. Special attention has been paid to the treatment of the neutron source and a significant effort has been devoted to validation purposes. It is justified that prompt and residual dose rates can be provided with a reasonably conservative margin.

A base line shielding consisting of a 1 m water tank and a concrete shield of 1 m thickness in front of the tank can be a good approach to fulfill the radioprotection requirement assigned to the beam-on phase. This approach will not be acceptable for the beam-off but it is seen that a feasible solution can be reached by adding a plug at the entrance of the beam dump.