Current status of decommissioning and waste management at the Ningyo-Toge Environmental Engineering Center

Ohashi, Yusuke ; Shimaike, Masamitsu; Matsumoto, Takashi; Takahashi, Nobuo; Yokoyama, Kaoru; Morimoto, Yasuyuki

At the Ningyo-Toge Center, technical development related to uranium refining conversion and enrichment has been completed, and decommissioning of these facilities has begun. The error between the quantity of dismantled materials estimated from the facility design drawings and the actual quantity of dismantled materials was minimal when averaging over the entire Uranium Refining and Conversion Plant and Uranium Enrichment Engineering Facility, which results indicated that the preliminary estimate of the quantity of dismantled materials for decommissioning was reasonable. Most of the dismantled materials, which have no contamination history and are properly managed were able to be carried out to recyclers as non-radioactive waste (NR). In addition, the possibility of evaluating the uranium concentration of clearance level in dismantled objects was confirmed through gamma-ray measurement tests using mock-up waste.