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Department of Decommissioning and Waste Management
JAEA-Review 2023-001, 136 Pages, 2023/06
JAEA-Review-2023-001.pdf:10.65MB
This report describes the activities of Department of Decommissioning and Waste Management (DDWM) in Nuclear Science Research Institute (NSRI) in the period from April 1, 2021 to March 31, 2022. The report covers organization and missions of DDWM, outline and operation/maintenance of facilities which belong to DDWM, treatment and management of radioactive wastes, decommissioning activities, and related research and development activities which were conducted in DDWM. In FY2021 radioactive wastes generated from R&D activities in NSRI were treated safely. They were about 206 m
of combustible solid wastes and 155 m of noncombustible solid wastes and 113 m of liquid wastes. After adequate treatment, 760 waste packages (in 200 L-drum equivalent) were generated. The total amounts of accumulated waste packages were 126,827 as of the end of FY2021 due to efforts of the restitution of waste packages to the Japan Radioisotope Association and volume reduction treatments of the stored waste packages. Decommissioning activities were carried out for the JAEA's Reprocessing Test Facility (JRTF), the Liquid Waste Treatment Facilities, the Compaction Facilities, and Fusion Neutronics Source (FNS) facilities. As for the R&D activities, studies on radiochemical analyses of wastes for disposal were continued. In order to pass the conformity review on the New Regulatory Requirements for waste management facilities, the Approval of the design and construction method was applied sequentially for the Nuclear Regulation Authority. The ministry of the Environment and Tokai-mura office requested JAEA to dispose of the contaminated soil generated by the accident of the Fukushima Daiichi Nuclear Power Station. The monitoring work at the playground was conducted during this period.
Department of Decommissioning and Waste Management
JAEA-Review 2022-001, 112 Pages, 2022/06
JAEA-Review-2022-001.pdf:6.51MB
This report describes the activities of Department of Decommissioning and Waste Management (DDWM) in Nuclear Science Research Institute (NSRI) in the period from April 1, 2020 to March 31, 2021. The report covers organization and missions of DDWM, outline and operation/maintenance of facilities which belong to DDWM, treatment and management of radioactive wastes, decommissioning activities, and related research and development activities which were conducted in DDWM. In FY2020 radioactive wastes generated from R&D activities in NSRI were treated safely. They were about 267 m of combustible solid wastes and 233 m of noncombustible solid wastes and 78 m of liquid wastes. After adequate treatment, 1,448 waste packages (in 200 L-drum equivalent) were generated. The total amounts of accumulated waste packages were 130,604 as of the end of FY2020 due to efforts of the restitution of waste packages to the Japan Radioisotope Association and volume reduction treatments of the stored waste packages. Decommissioning activities were carried out for the JAEA's Reprocessing Test Facility (JRTF), the Liquid Waste Treatment Facilities, the Compaction Facilities, and Fusion Neutronics Source (FNS) facilities. As for the R&D activities, studies on radiochemical analyses of wastes for disposal were continued. In order to pass the conformity review on the New Regulatory Requirements for waste management facilities, the Approval of the design and construction method was applied sequentially for the Nuclear Regulation Authority. The ministry of the Environment and Tokai-mura office requested JAEA to dispose of the contaminated soil generated by the accident of the Fukushima Daiichi Nuclear Power Station. The monitoring work at the playground was conducted during this period.
Tsuchimochi, Akari; Suda, Shoya; Fujikura, Toshiki; Kawahara, Takahiro; Hoshi, Akiko
JAEA-Technology 2021-018, 37 Pages, 2021/10
JAEA-Technology-2021-018.pdf:2.87MB
A large amount of radioactive waste has been generated in the process of research and development in Nuclear Science Research Institute. We store the equivalent of 130,604 drums (200L) of that in our storage facilities (as of March 31, 2021) and have been developing "Radioactive Waste Information Management System" to manage them for disposal. The system started designing in FY2007 and has been in operation since FY2012. After the start of operation, it has been repaired as appropriate. In this report, we summarized the development and improvement of the system.
Department of Decommissioning and Waste Management
JAEA-Review 2021-002, 105 Pages, 2021/05
JAEA-Review-2021-002.pdf:9.68MB
This report describes the activities of Department of Decommissioning and Waste Management (DDWM) in Nuclear Science Research Institute (NSRI) in the period from April 1, 2019 to March 31, 2020. The report covers organization and missions of DDWM, outline and operation/maintenance of facilities which belong to DDWM, treatment and management of radioactive wastes, decommissioning activities, and related research and development activities which were conducted in DDWM. In FY2019 radioactive wastes generated from R&D activities in NSRI were treated safely. They were about 323 m of noncombustible solid wastes and 111 m of liquid wastes. After adequate treatment, 2,588 waste packages (in 200 L-drum equivalent) were generated. The total amounts of accumulated waste packages were 130,223 as of the end of FY2019 due to efforts of the restitution of waste packages to the Japan Radioisotope Association and volume reduction treatments of the stored waste packages. Decommissioning activities were carried out for the JAEA's Reprocessing Test Facility (JRTF), the Liquid Waste Treatment Facilities, the Decontamination Facilities, and Fusion Neutronics Source (FNS) facilities. As for the R&D activities, studies on radiochemical analyses of wastes for disposal were continued. In order to pass the conformity review on the New Regulatory Requirements for waste management facilities, the Approval of the design and construction method was applied sequentially for the Nuclear Regulation Authority. The ministry of the Environment and Tokai-mura office requested JAEA to dispose of the contaminated soil generated by the accident of the Fukushima Daiichi Nuclear Power Plant. The monitoring work at the playground was conducted during this period.
Department of Decommissioning and Waste Management
JAEA-Review 2020-012, 103 Pages, 2020/08
JAEA-Review-2020-012.pdf:8.17MB
This report describes the activities of Department of Decommissioning and Waste Management (DDWM) in Nuclear Science Research Institute (NSRI) in the period from April 1, 2018 to March 31, 2019. The report covers organization and missions of DDWM, outline and operation/maintenance of facilities which belong to DDWM, treatment and management of radioactive wastes, decommissioning activities, and related research and development activities which were conducted in DDWM.
Department of Decommissioning and Waste Management
JAEA-Review 2019-011, 91 Pages, 2019/10
JAEA-Review-2019-011.pdf:5.25MB
This report describes the activities of Department of Decommissioning and Waste Management (DDWM) in Nuclear Science Research Institute (NSRI) in the period from April 1, 2017 to March 31, 2018. The report covers organization and missions of DDWM, outline and operation/maintenance of facilities which belong to DDWM, treatment and management of radioactive wastes, decommissioning activities, and related research and development activities which were conducted in DDWM.
Department of Decommissioning and Waste Management
JAEA-Review 2018-008, 87 Pages, 2018/07
JAEA-Review-2018-008.pdf:2.67MB
This report describes the activities of Department of Decommissioning and Waste Management (DDWM) in Nuclear Science Research Institute (NSRI) in the period from April 1, 2016 to March 31, 2017. The report covers organization and missions of DDWM, outline and operation/maintenance of facilities which belong to DDWM, treatment and management of radioactive wastes, decommissioning activities, and related research and development activities which were conducted in DDWM.
Ishihara, Keisuke; Kanazawa, Shingo; Kozawa, Masachiyo; Mori, Masakazu; Kawahara, Takahiro
JAEA-Technology 2017-002, 27 Pages, 2017/03
JAEA-Technology-2017-002.pdf:21.88MB
At radioactive waste management facilities in the Nuclear Science Research Institute, solid radioactive wastes are stored by using containers such as 200L drums and pallets to tier containers in 2 to 4 stacks in the height direction in waste storage facilities (Waste Storage Facility No.1, Waste Storage Facility No.2 and Waste Size Reduction and Storage Facility). On March 11, 2011, the Great East Japan Earthquake was happened, and some waste packages dropped from their pallets and large number of waste packages moved from their original position and inclined due to the influence of the earthquake in the waste storage facilities. There was no experience of rearrangement works to set those dropped and unbalanced waste packages in their original position and it was necessary to prepare detailed work procedures and progress for this task to prevent the occurrence of industrial accidents. Therefore, we prepared detailed work manual and repeatedly carried out mock-up test. And then, we started rearrangement work from April 2011 after confirmation of workers skill and adequacy of the work manual. Finally, all rearrangement works for stored waste packages took about four and half years and were completed in September 2015 without any accident and shutdown of storage function. This report summarizes the countermeasures to reduce exposure doses of workers and to prevent the occurrence of industrial accidents during the rearrangement works.
Satoyama, Tomonori; Nanri, Tomohiro; Kishimoto, Katsumi
Hoken Butsuri, 49(4), p.180 - 189, 2014/12
JAEA planned to apply the clearance system to slightly contaminated concrete debris with radionuclides, which was generated from the modification of the JRR-3. The modification work was conducted from 1985 to 1990 and the generated concrete debris has been stored as radioactive waste in interim storage facilities. JAEA established procedures for measuring and evaluating the radioactivity concentration of sored concrete debris. In 2008, the authority approved these procedures for clearance. Since 2009, JAEA have been measuring and evaluating the radioactivity concentration of concrete debris, using the approved procedures. By the end of 2012, the authority had confirmed the correctness of our measurement and evaluation results on about 2,600 tons of concrete debris. About 1,800 tons of those cleared concrete were recycled to flat surface subsidence in the NSRI caused by the Great East Japan Earthquake, and also used as base material to construct new buildings and parking lots.
Department of Decommissioning and Waste Management
JAEA-Review 2009-007, 99 Pages, 2009/06
JAEA-Review-2009-007.pdf:12.4MB
This reports described the activities of Department of Decommissioning and Waste Management (DDWM) in the period from April 1, 2007 to March 31, 2008. In FY2007 radioactive wastes generated from R&D activities were about 371 m of combustible solid wastes, 152 m of noncombustible solid wastes and 510 m of liquid wastes. After adequate treatment 2,111 waste packages were generated. Two new approaches were conducted for radioactive waste management: development of record keeping system for land burial and a new management system for mid-level radioactive waste packages. Decommissioning activities were carried out as planned for the JAEA's Reprocessing Test Facility, the Ceramic Fuel Laboratory, the Plutonium Laboratory No.2 and the Metallurgical Laboratory. As for the R&D activities, studies were conducted on radiochemical analyses of wastes for land burial, and decommissioning. As for the clearance was applied for approval of nuclide measureing.
Nankawa, Takuya; Ogoshi, Yurie
no journal, ,
Removal of cesium by porous materials from various environments has recently attracted much attention because of the Fukushima crisis. Among the porous materials, Prussian-blue has so high Cs selectivity that they can be used even in the sea water. But because they had a possibility to generate HCN gas by the radioactive decomposition, they were not used in Fukushima. We synthesized novel rare earth organic framework with the formula of Re(NH
)(C
O)(HO) (Re = Y, Eu, Tb, Dy, Ho, Er) by modifying the pores of Prussian blue. We used single crystal X-ray diffraction analysis to determine the molecular structures of Tb(NH)(CO)(HO). The diameter of the pore around NH4 is about the same size with the pores of Prussian blue. And it was revealed that the structures of MOFs are isostructural and their pore sizes of are precisely controlled by changing lanthanide ions. We demonstrated Cs uptake experiment in water solution and revealed that Cs was uptaken by the MOFs.
Kishimoto, Katsumi; Satoyama, Tomonori; Takaizumi, Hirohide; Kanno, Tomoyuki; Maruyama, Tatsuya; Yoshimori, Michiro
no journal, ,
We have been storing about 4000 tons of very low-level radioactive concrete debris as radioactive wastes generated from the modification of JRR-3 between 1985 and 1990. At that time, the clearance system was not a part of our regulatory law. We conducted a preliminary survey of contamination levels, and then established procedures for measuring and evaluating the radioactivity concentration. In 2008, the government authorized our procedures for clearance. Since FY 2009, we have measured the radioactivity concentration of concrete debris, using the government-authorized procedures. By the end of FY 2012, the government had confirmed the correctness of our measurements and evaluation results on about 1900 tons of concrete debris. We processed the concrete debris that was approved by the government for recycling. By the end of FY 2012, we had reused about 600 tons of concrete debris as backfilling material in depressed areas around buildings in the Nuclear Science Research Institute.
Kuwahara, Akira; Nankawa, Takuya; Matsui, Makoto*
no journal, ,
In this research, we propose a novel laser absorption spectroscopy (LAS) system combined with high enthalpy wind tunnel to measure the isotope ratio of radioactive elements in nuclear fuel and radioactive waste. In detecting the isotope ratio of radioactive elements, spectroscopic technique with high wavelength selectivity would be effective, but no established method is available due to the small differences in energy levels of isotopes. We use the supersonic nozzle in high enthalpy wind tunnel and applied LAS to the downstream flow to enhance the wavelength resolution by decreasing the spectral width attribute to the flow temperature. In this paper, first the measurable range of atomic species was discussed. Next, we demonstrated measurements of the isotope ratio by using xenon gas. As a result, isotope shifts of xenon atoms were detected and the spectral width was evaluated for a variation of the gas temperature.
Kuwahara, Akira; Osugi, Takeshi; Hanawa, Ritsu; Ito, Keisuke; Nakashio, Nobuyuki; Kozawa, Kazushige; Meguro, Yoshihiro; Akabori, Mitsuo; Okamoto, Yoshihiro; Nakashima, Kunihiko*; et al.
no journal, ,
In order to obtain the knowledge about cesium accumulations into the refractory in ash melting of decontamination waste, the immersion test was worked by immersing the refractory into melting slug including cesium, and cesium chemical forms in the refractory were analyzed.
Furutani, Misa; Aoyagi, Hiroyuki*; Shirato, Yoshihiro; Nojima, Shun; Nakagawa, Masahiro; Otsuka, Yoshikazu; Niinuma, Shinichi*; Sakai, Toshiya; Muto, Yasushi; Nanri, Tomohiro; et al.
no journal, ,
no abstracts in English
Suda, Shoya; Masai, Seita; Kawahara, Takahiro; Fujikura, Toshiki; Hoshi, Akiko; Wakai, Eiichi; Kondo, Keietsu; Nishimura, Akihiko; Minehara, Eisuke*
no journal, ,
no abstracts in English
Suda, Shoya; Kosuge, Atsushi; Kisohara, Naoyuki; Fujii, Mitsuki; Masai, Seita; Iseda, Hirokatsu; Minehara, Eisuke*
no journal, ,