Evaluation of the production amount of 225Ac and its uncertainty through the 226Ra(n,2n) reaction in the experimental fast reactor Joyo

Abstract

ABSTRACT 225Ac is a promising nuclide for targeted alpha therapy. At present, the nuclide is mainly extracted from 229Th generators, but its total radioactivity of the world is only 63 GBq/y. Therefore, it is unclear whether this method alone can meet future global medical demand. In this study, we analyzed the production amount of 225Ac and its uncertainty due to the neutron flux and nuclear reaction cross-sections while analyzing the generation process of 225Ac using the experimental fast reactor Joyo operated by the Japan Atomic Energy Agency (JAEA). The analysis showed that irradiating 1 g of 226Ra for 45 d at the core center of Joyo can produce 15.4 ± 6.2 GBq of 225Ac. Therefore, with six irradiations per year (45 d × 6 = 270 d/year), Joyo can produce 55.3 to 129.1 GBq of 225Ac, equivalent to 86 to 200% of the current world supply.