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*; et al.

JAEA-Technology 2025-003, 110 Pages, 2025/10

JAEA-Technology-2025-003.pdf:11.5MB

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.

Annual report on the effluent control of low level liquid waste in Nuclear Fuel Cycle Engineering Laboratories FY2022

Kokubun, Yuji; Nakada, Akira; Seya, Natsumi; Nagaoka, Mika; Koike, Yuko; Kubota, Tomohiro; Hirao, Moe; Yoshii, Hideki*; Otani, Kazunori*; Hiyama, Yoshinori*; et al.

JAEA-Review 2023-052, 118 Pages, 2024/03

JAEA-Review-2023-052.pdf:3.67MB

Based on the regulations (the safety regulation of Tokai Reprocessing Plant, the safety regulation of nuclear fuel material usage facilities, the radiation safety rule, the regulation about prevention from radiation hazards due to radioisotopes, which are related with the nuclear regulatory acts, the local agreement concerning with safety and environment conservation around nuclear facilities, the water pollution control law, and by law of Ibaraki Prefecture), the effluent control of liquid waste discharged from the Nuclear Fuel Cycle Engineering Laboratories of Japan Atomic Energy Agency has been performed. This report describes the effluent control results of the liquid waste in the fiscal year 2022. In this period, the concentrations and the quantities of the radioactivity in liquid waste discharged from the reprocessing plant, the plutonium fuel fabrication facilities, and the other nuclear fuel material usage facilities were much lower than the limits authorized by the above regulations.

Annual report on the effluent control of low level liquid waste in Nuclear Fuel Cycle Engineering Laboratories FY2020

Nakano, Masanao; Nakada, Akira; Kanai, Katsuta; Nagaoka, Mika; Koike, Yuko; Yamada, Ryohei; Kubota, Tomohiro; Yoshii, Hideki*; Otani, Kazunori*; Hiyama, Yoshinori*; et al.

JAEA-Review 2021-040, 118 Pages, 2021/12

JAEA-Review-2021-040.pdf:2.48MB

Based on the regulations (the safety regulation of Tokai Reprocessing Plant, the safety regulation of nuclear fuel material usage facilities, the radiation safety rule, the regulation about prevention from radiation hazards due to radioisotopes, which are related with the nuclear regulatory acts, the local agreement concerning with safety and environment conservation around nuclear facilities, the water pollution control law, and by law of Ibaraki Prefecture), the effluent control of liquid waste discharged from the Nuclear Fuel Cycle Engineering Laboratories of Japan Atomic Energy Agency has been performed. This report describes the effluent control results of the liquid waste in the fiscal year 2020. In this period, the concentrations and the quantities of the radioactivity in liquid waste discharged from the reprocessing plant, the plutonium fuel fabrication facilities, and the other nuclear fuel material usage facilities were much lower than the limits authorized by the above regulations.

Extraction of trivalent rare earths and minor actinides from nitric acid with -tetradodecyldiglycolamide (TDdDGA) by using mixer-settler extractors in a hot cell

Ban, Yasutoshi; Suzuki, Hideya; Hotoku, Shinobu; Kawasaki, Tomohiro*; Sagawa, Hiroshi*; Tsutsui, Nao; Matsumura, Tatsuro

Solvent Extraction and Ion Exchange, 37(1), p.27 - 37, 2019/00

https://doi.org/10.1080/07366299.2019.1586347

A continuous counter-current experiment using TDdDGA was performed using mixer-settler extractors installed in a hot cell. Nitric acid containing minor actinides (MAs: Am and Cm), rare earths (REs: Y, La, Nd, and Eu), and other fission products (Sr, Cs, Zr, Mo, Ru, Rh, and Pd) was fed to the extractor. TDdDGA effectively extracted MAs and REs from the feed, while other fission products were barely extracted. The extracted MAs and REs were back-extracted by bringing them in contact with 0.02 mol/dm nitric acid, and they were collected as the MA-RE fraction. The proportions of MA and RE in the MA-RE fraction were 98% and 86%, respectively. These results demonstrated the applicability of TDdDGA as an extractant for MAs and REs.

An Evaluation method for plastic buckling of cantilever type pipes controlled by displacement loads, 2; Verification of proposal method by buckling test

Ando, Masanori; Tezuka, Taiji*; Nakamura, Toshio*; Okawa, Tomohiro*; Enuma, Yasuhiro*; Kawasaki, Nobuchika; Tsukimori, Kazuyuki

Proceedings of 2011 ASME Pressure Vessels and Piping Conference (PVP 2011) (CD-ROM), 8 Pages, 2011/07

アクチノイド及び/又はランタノイドの抽出方法

鈴木 英哉; 松村 達郎; ト部 峻一; 黒澤 達也; 川崎 倫弘

国井 茂*; 吉田 貴昌*; 成田 弘一*; 田中 幹也*

JP, 2014-254092  Patent licensing information  Patent publication (In Japanese)

【課題】原子力分野や鉱工業分野で利用できるアクチノイドやランタノイドの効率的な抽出方法を提供することを目的とする。 【解決手段】アクチノイド及び/又はランタノイドを含む酸性水溶液を、下記一般式(A)(化学式のため省略)で表されるイミノ二酢酸ジアミドの存在下で有機溶媒に接触させることにより、アクチノイド及び/又はランタノイドを有機溶媒に溶解させて、効率良く抽出することができる。

Examination of new extractants for minor actinides separation

Suzuki, Hideya; Tsubata, Yasuhiro; Kurosawa, Tatsuya*; Shibata, Mitsunobu*; Kawasaki, Tomohiro*; Matsumura, Tatsuro

no journal, , 

The Japan Atomic Energy Agency has been studying partitioning and transmutation (P&T) systems. In the P&T, the separation of Am and Cm from the chemically similar lanthanides is the key step. After MAs are separated from high-level waste, the mutual separation of Am and Cm (Am/Cm separation) can be conducted. Therefore, the removal of the pyrogenic Cm nuclide would reduce the difficulties associated with MA-fuel fabrication. However, Am/Cm separation is very challenging because the two elements have similar chemical and physical properties. Highly practical new reagents, called HONTA and ADAAM have been developed. We report the behavior of new extractants for the separation of MA.

Investigation of a new extraction method for americium separation from high-level liquid waste

Suzuki, Hideya*; Ban, Yasutoshi; Tsubata, Yasuhiro; Hotoku, Shinobu; Morita, Keisuke; Toigawa, Tomohiro; Tsutsui, Nao; Kurosawa, Tatsuya*; Shibata, Mitsunobu*; Kawasaki, Tomohiro*; et al.

no journal, , 

The Japan Atomic Energy Agency has been studying partitioning and transmutation (P&T) systems. In the P&T, the separation of minor actinide (MA) from the chemically similar lanthanides is the key step. After MAs are separated from high-level liquid waste (HLLW), the mutual separation of Am and Cm (Am/Cm separation) can be conducted. Therefore, the removal of the pyrogenic Cm nuclide would reduce the difficulties associated with MA-fuel fabrication. However, Am/Cm separation is very challenging because the two elements have similar chemical and physical properties. Highly practical new reagents, called HONTA and ADAAM have been developed. Solvent extraction tests were performed using a mixture of HONTA and ADAAM. As a result, the separation of Am from the simulated HLLW was achieved with high yield.

Development of a new extraction method for americium separation from high-level liquid waste, 2

Suzuki, Hideya*; Ban, Yasutoshi; Hotoku, Shinobu; Morita, Keisuke; Tsutsui, Nao; Kurosawa, Tatsuya*; Shibata, Mitsunobu*; Kawasaki, Tomohiro*; Matsumura, Tatsuro

no journal, , 

The Japan Atomic Energy Agency (JAEA) has been studying partitioning technology. Recently, JAEA proposed a new liquid-liquid extraction technology called SELECT (Solvent Extraction from Liquid-waste using Extractants of CHON-type for Transmutation) process to separate minor actinide (MA) from high-level liquid waste (HLLW) for transmutation. In this process, new extractants (HONTA, ADAAM) with highly practical and high extraction ability for MA was developed. In the present study, a new solvent extraction method using a mixture of HONTA and ADAAM was investigated. In the tests, it was found that the separation of Am from the simulated HLLW was achieved with very high yield.

Extraction behaviors of minor actinides and rare earth elements with four NTA amide extractants

Suzuki, Hideya*; Nakamura, Satoshi; Emori, Tatsuya; Kurosawa, Tatsuya*; Shibata, Mitsunobu*; Kawasaki, Tomohiro*; Ban, Yasutoshi

no journal, , 

The Japan Atomic Energy Agency (JAEA) has been studying partitioning and transmutation systems (P&T). In P&T, JAEA proposed a novel hydrometallurgical process called "SELECT (Solvent Extraction from Liquid waste using Extractants of CHON-type for Transmutation) process". In the SELECT process, HexaOctyl NitriloTriacetAmide (HONTA) with six -octyl side chains is used for the mutual separation of minor actinides (MA) and rare earth elements (RE). In the present study, extraction tests were carried out with HONTA and three nitrilotriacetamides (NTA amides) with different side chains. The results show that the different side chains of NTA amides affect the extraction behaviors of MA and RE.