Decommissioning state of Plutonium Fuel Fabrication Facility; Dismantling the Glove Box W-4,W-5,W-6-1,W-6-2 and equipment interior

Nagai, Yuya; Kimura, Yasuhisa ; Takeuchi, Kentaro ; Shuji, Yoshiyuki ; Kawasaki, Takeshi; Hirano, Koji*; Tomiyama, Noboru*; Usui, Yasuhiro*; Nidaira, Seiichiro*; Shinozaki, Tomohiro*; Hirano, Hiroshi*

Japan Atomic Energy Agency (JAEA) manages wide range of nuclear facilities. Many of these facilities are required to be performed adjustment with the aging and complement with the new regulatory standards and the earthquake resistant, since the Great East Japan Earthquake and the Fukushima Daiichi Nuclear Power Station accident. It is therefore desirable to promote decommissioning of facilities that have reached the end of their productive life in order to reduce risk and maintenance costs. However, the progress of facility decommissioning require large amount of money and radioactive waste storage space. In order to address these issues, JAEA has formulated a "The Medium/Long-Term Management Plan of JAEA Facilities" with three pillars: (1) consolidation and prioritization of facilities, (2) assurance of facility safety, and (3) back-end countermeasures. In this plan, Plutonium Fuel Fabrication Facility has been selected as primary decommissioned facility, and dismantling of equipment in the facilities have been underway. The following gloveboxes were dismantled between March 2020 and March 2022: Glovebox No. W-4, which houses the roasting furnace, washing and dewatering tank, and washing waste tank; Glovebox No. W-5, which houses the weighing tank; Glovebox No. W-6-1, which houses the flocculation-sedimentation tank, slurry-receiving tank, neutralization tank, and receiving tank; and Glovebox No. W-6-2, which houses the adjustment tank, adjustment liquid agitator, adsorption tower, discharge tank, discharge tank agitator, and adsorption tower. This report summarizes the results of the work and the findings obtained through the dismantling of these gloveboxes.