Shielding analysis of the SPES targets handling system and storage area using the Monte Carlo code FLUKA

The SPES project (Selective Production of Exotic Species) is currently under advanced construction phase at the INFN-LNL (Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro) for the production of Radioactive Ion Beams. Several typologies of target systems will be used in different SPES production phases. The irradiated target system has a limited lifetime and has to be regularly replaced. As a consequence, the handling and the temporary storage of exhausted radioactive targets are a major concern for the management of the entire facility. Monte Carlo simulation codes as FLUKA and MCNPX are used for shielding design. Results of shielding simulations are here presented, realized using a complete FLUKA model of the system and multi-step simulations. In particular, two case studies are discussed, referring to the management of different phases of the SPES project which require human intervention. The results allow some conclusions about the safe design of shieldings to be drawn.