Radiation Protection Design and Licensing for an Experimental Fusion Facility: The Italian and European Approaches

SORGENTINA-RF FUSION NEUTRON PLANT: PRELIMINARY DESIGN OF THE BIOSHIELDING 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 baritic 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.

Risk Management of a Fusion Facility: Radiation Protection and Safety Integrated Approach for the Sorgentina-RF Project

The Sorgentina-RF project will use fusion neutrons to produce 99Mo, a precursor of 99mTc, by irradiating natural molybdenum. 99Mo is produced by means of the inelastic reaction 100Mo(n, 2n)99Mo on 100Mo, which is an isotope of natural Mo. From a functional point of view, the project consists of two parts: an irradiation neutron source at 14 MeV and a radiochemistry facility dedicated to the extraction of 99Mo from the solid sample irradiated by the neutron source. Given the degree of complexity of such a facility, the risk management strategy is based on an integrated approach that combines the engineering method of safety with that of radiation protection. Therefore, design issues were studied and systems were planned according to both radiation protection and safety criteria already in the preliminary phase, allowing a general strengthening of the safety of the plant. This work discusses the preventive analysis and the related activities to identify the ways in which potential exposures to radiation may occur. In particular, the preliminary safety analysis is presented for the innovative rotating target, developed for the project, and, accordingly, some specific technical solutions are given to refine the initial design of the facility.