SORGENTINA-RF fusion neutron plant: preliminary design of the bio-shielding in compliance with dose constraints for workers exposure

An accelerator-driven 14 MeV neutron source of new concept, denominated SORGENTINA-RF, will be installed in ENEA Brasimone Research Centre, to test the feasibility of producing radionuclides of medical relevance using fusion neutrons. The main goal of the facility is generating ⁹⁹Mo as precursor of ^99mTc, a radionuclide widely used in nuclear medicine diagnostic procedures, using the 14 MeV fusion neutrons produced by the plant. This work describes the study performed for the design of a proper shielding structure that aims at fulfilling the requirement of 0.01 mSv/h dose rate limit on the external surface of the shielding during beam-on operations. The proposed shielding consists of a layered structure composed of 2 m standard concrete and 1 m barytic concrete. The design is still in the preliminary phase to assess the feasibility and the economic issues as well as structural impact of the shielding structure. (authors)