Activation of the inner irradiation Snail after long-term operation of the KATANA irradiation facility

The primary coolant in fusion reactors such as ITER is water. In recent years, research has increasingly focused on the irradiation and activation of water, which leads to the formation of ionizing radiation fields. To better understand these phenomena, the KATANA irradiation facility for water activation was commissioned in early 2024 at the Jožef Stefan Institute. Since its initial testing, several upgrades and developments have been implemented. In 2026, the inner irradiation head where the water is irradiated in the reactor, is planned to be removed and replaced with an ITER relevant head design that more accurately replicates ITER’s cooling components. Ahead of this replacement, a comprehensive neutron activation analysis of the current head, has been conducted to support the licensing process and ensure the safe removal. This paper presents the results of activation calculations for the inner head after long-term operation of KATANA, utilising the neutron irradiation field of the JSI TRIGA reactor. These preliminary calculations will aid in ensuring the safe maintenance of the KATANA facility and provide valuable insights for predicting the activation of its internal components.