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Owada, Mitsuhiro; Nakanishi, Yoshiki; Murokawa, Toshihiro; Togashi, Kota; Saito, Katsunori; Nonaka, Kazuharu; Sasaki, Yu; Omori, Koji; Chinone, Makoto; Yasu, Hideto; et al.
JAEA-Technology 2024-013, 221 Pages, 2025/02
JAEA-Technology-2024-013.pdf:14.98MB
The uranium enrichment facilities at the Nuclear Fuel Cycle Engineering Laboratories of Japan Atomic Energy Agency (JAEA) were constructed sequentially to develop uranium enrichment technology with centrifugal separation method. The developed technologies were transferred to Japan Nuclear Fuel Limited until 2001. And the original purpose has been achieved. Wastewater Treatment Facility, one of the uranium enrichment facilities, was constructed in 1976 to treat radioactive liquid waste generated at the facilities, and it finished the role in 2008. In accordance with the Medium/Long-Term Management Plan of JAEA Facilities, interior equipment installed in this facility had been dismantled and removed since November 2021 to August 2023. This report summarizes the findings obtained through the work related to dismantling and removal of interior equipment for decommissioning of Wastewater Treatment Facility.
Kijima, Jun; Koyama, Hayato; Owada, Mitsuhiro; Hagiwara, Masayoshi; Aoyagi, Yoshitaka
JAEA-Technology 2022-012, 14 Pages, 2022/07
JAEA-Technology-2022-012.pdf:1.51MB
Steam reforming system has been developed for the treatment of organic wastes which are not suitable materials (halogenated oil) for the incineration due to generation of corrosive compounds and plugging materials. The refractory material is cast inside the main reactor, which is a part of the steam reforming system. Since the surface of this refractory material has deteriorated over time, the main reactor was replaced. If the refractory material surface of the used main reactor can be repaired, the used main reactor can be reused as a spare. The refractory material surface was repaired using two types of repair materials ("S" and "P"). Combustion tests were conducted on samples simulating organic wastes to evaluate each repair material. As a result of the combustion test, it was concluded that the repair of the main reactor was possible to use the repair material "P" because no cracks or flakes were observed.
Kijima, Jun; Koyama, Hayato; Owada, Mitsuhiro; Shibata, Atsuhiro
no journal, ,
Japan Atomic Energy Agency (JAEA) has been developing a steam reforming system and equipment for the treatment of difficult-to-treat organic liquid wastes. The main reactor, which is a main component of the treatment system, has a refractory material on the inner surface. Cracks and flakes were observed on the surface of the refractory material due to age-related deterioration. Therefore, we repaired the deteriorated refractory material surfaces using two types of repair materials and conducted combustion tests on simulated samples to evaluate each repair material. After the combustion test, we concluded that the repair of the main reactor using the repair materials was possible, since there were no cracks or flakes of repair materials.
Owada, Mitsuhiro; Koyama, Hayato; Kijima, Jun; Shibata, Atsuhiro
no journal, ,
Japan Atomic Energy Agency (JAEA) has been developing a steam reforming system and equipment for the treatment of difficult-to-treat organic liquid wastes. In the continuous treatment of fluorine oil, soot generated during fluorine oil decomposition clogs the exhaust filter and causes unstable combustion. The influence of soot was evaluated by conducting treatment tests using the mixing ratio of fluorine oil and auxiliary fuel as parameters and checking the effect of decomposition temperature. As a result, the filter was not blocked at fluorine oil concentrations up to 20%, and increasing the decomposition temperature burns off the soot and reduces the blockage of the filter. The effects of equipment corrosion due to long-term continuous processing were also identified as an issue.
Koyama, Hayato; Kijima, Jun; Shimojo, Hiroto; Nakagawa, Takuya; Owada, Mitsuhiro; Sone, Tomoyuki
no journal, ,
Spent tri-n-butyl phosphate/n-dodecane contaminated with uranium and spent fluorine oil are stored in the Japan Atomic Energy Agency (JAEA). The purpose of this study is to reduce the volume of these wastes, convert it into a stable chemical form, and reduce the amount of storage using the steam assisted pyrolysis system we are developing. We report on the results of treatment of several organic liquid wastes and explain the corrosion prevention methods of this system.
Owada, Mitsuhiro; Nakanishi, Yoshiki; Aoyama, Yoshio; Suguro, Toshiyasu
no journal, ,
As a decommissioning measure of the Wastewater Treatment Area, which was constructed treat radioactive liquid waste generated at the uranium enrichment facilities, dismantling and removal of the interior equipment was conducted from November 2021 to August 2023 in preparation for cancellation the controlled area. During the dismantling and removal work, all potentially contaminated equipment and other items were removed in order to perform contamination inspection for cancellation the controlled area. This presentation shows the findings obtained through the work related to dismantling and removal of interior equipment for decommissioning.
Nakanishi, Yoshiki; Owada, Mitsuhiro; Aoyama, Yoshio; Suguro, Toshiyasu
no journal, ,
The uranium enrichment facilities at the Nuclear Fuel Cycle Engineering Laboratories of Japan Atomic Energy Agency (JAEA) were constructed sequentially to develop uranium enrichment technologies with centrifugal separation method and consisted of several facilities for R&D objectives. These developed technologies were transferred to Japan Nuclear Fuel Limited by 2001 and the initial goal was achieved. Wastewater Treatment Area, which was constructed treat radioactive liquid waste generated at the facilities, was to be decommissioned for the role of end and deterioration over time. Decommissioning of the facility included dismantling and removal of interior facilities and radiation measurements from 2003 to 2023 in preparation for cancellation the controlled area. This presentation is summary of the Wastewater Treatment Area decommissioning.