The ENEA TRIGA RC-1 facility inside the SECURE project. Production of medical isotopes by neutron activation

TRIGA (Training, Research, and Isotope production General Atomics) facilities are research reactors extensively used for neutron activation analyses and various neutron-related experiments and applications. Neutron fluxes in TRIGA reactors can be employed for radionuclide production through techniques such as Neutron Activation Analysis (NAA), enabling the generation of radioactive sources for technical applications and the production of medical isotopes. In this process, a nonradioactive material is exposed to neutrons, resulting in the generation of radioactive nuclei. The ENEA TRIGA RC-1 reactor is involved in the EUfunded SECURE Project (HORIZON-EURATOM-2021NRT-01 call, Strengthening the European Chain of sUpply for next generation medical RadionuclidEs, October 2022September 2025), which aims to explore the feasibility of local radionuclide production for medical applications in Europe, including both currently established and innovative ways. Specifically, the ENEA team investigated the potential to produce terbium-161 (161Tb), an isotope that shows promise for targeted radionuclide therapy and may offer advantages over lutetium-177 (177Lu), which is currently used in cancer treatment. 161Tb production exploits the reaction channel 160Gd(n,γ)161Gd(β−)161Tb, involving the neutron activation of a gadolinium (Gd) target that is highly enriched (more than 98%) in gadolinium-160 (160Gd). After the appropriate chemical processes, both 161Tb (the raw radionuclide precursor for radiopharmaceuticals used in cancer therapy) and 160Gd oxide (which can be reused for future irradiation cycles) are extracted and purified.