Status of the 226 Ra nuclear data library and its impact on the production amount of 225 Ac via the 226 Ra (n,2n) reaction

225Ac is a promising alpha emitter for targeted alpha therapy. However, the current capability of 225Ac supply is limited to approximately 63 GBq/y, primarily relying on the natural source of 229Th stocked at a few institutes. Therefore, alternative 225Ac production methods are highly desired. The research and development of 225Ac and its parent nuclide production methods using accelerators and reactors to target 226Ra and 232Th are actively pursued worldwide. Hence, the authors focused on the 226Ra(n,2n)225Ra method using fast neutron spectra as an application of the experimental fast reactor Joyo. This study investigated the status of nuclear data libraries for 226Ra, an essential target for 225Ac production, and evaluated the impact of different nuclear data libraries on the amount of 225Ac produced. Consequently, cross-sections with covariance data were stored in TENDL-2021, JEFF-3.3, and EAF-2010 but not in ENDF or JENDL, the major nuclear data libraries. Furthermore, no consistency occurred among the respective nuclear data, and the 225Ra production amount varied.