Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Yokozuka, Yuta; Sunaoshi, Mizuho*; Sakai, Tatsuya; Fujikura, Toshiki; Handa, Yuichi; Muraguchi, Yoshinori; Mimura, Ryuji; Terunuma, Akihiro
JAEA-Technology 2021-037, 44 Pages, 2022/03
JAEA has dismantled equipment and instrument in the JAERI's Reprocessing Test Facility (JRTF) since 1996 as a part of its decommissioning. Starting in JFY 2007, in the annex building B which stored liquid waste generated in wet reprocessing tests, the liquid waste storage tank LV-1 installed in the LV-1 room of the first basement was dismantled with the in-situ dismantling method. The dismantling work is described in this report. Data on manpower, radiation control, and waste in the preparation work were collected, and its work efficiency was analyzed.
Yokozuka, Yuta; Sunaoshi, Mizuho*; Fujikura, Toshiki; Suzuki, Shota; Muraguchi, Yoshinori; Handa, Yuichi; Mimura, Ryuji; Terunuma, Akihiro
JAEA-Technology 2020-017, 56 Pages, 2021/01
JAEA has dismantled equipment and instrument in the JAERI's Reprocessing Test Facility (JRTF) since 1996 as a part of its decommissioning. Starting in JFY 2007, in the annex building B which stored liquid waste generated in wet reprocessing tests, the liquid waste storage tank LV-1 installed in the LV-1 room of the first basement was dismantled with the in situ dismantling method. The dismantling preparation work is described in this report. Data on manpower, radiation control, and waste in the preparation work were collected, and its work efficiency was analyzed.
Kawatsuma, Shinji; Mimura, Ryuji; Asama, Hajime*
ROBOMECH Journal (Internet), 4, p.6_1 - 6_7, 2017/02
It was cleared that portability of emergency response reconnaissance robot had been very important. So, RESQ-A robots, which had been developed by Japan Atomic Energy Research Institute (present Japan Atomic Energy Agency), had been considered from the view point of portability. After Fukushima Daiichi NPPs' accidents occurred, JAEA had modified a RESQ-A robot to JAEA-3 robot in order to meet the anticipated situation of the accidents. However, actual situation was beyond the anticipated situation, and additional modification was required. The actual confused situation was many rubble were scattered and temporary cables and hoses were constructed in the reactor buildings, so that reconnaissance robots should be conveyed by operators through limited route, should be reassembled in short time and should be able to remove cable and tiers for reduce the operators' exposure dose during maintenance. JAEA modified again JAEA-3 robot system, with cooperation of operators from Fukushima Daiichi NPPs. It was lesson learned that emergency response reconnaissance robot needed to be unitized for portability, and "Unitization Policy for emergency response reconnaissance robot" was developed.
Terunuma, Akihiro; Mimura, Ryuji; Nagashima, Hisao; Aoyagi, Yoshitaka; Hirokawa, Katsunori*; Uta, Masato; Ishimori, Yuu; Kuwabara, Jun; Okamoto, Hisato; Kimura, Yasuhisa; et al.
JAEA-Review 2016-008, 98 Pages, 2016/07
Japan Atomic Energy Agency formulated the plan to achieve the medium-term target in the period of April 2010 to March 2015(hereinafter referred to as "the second medium-term plan"). JAEA determined the plan for the business operations of each year (hereinafter referred to as "the year plan"). This report is that the Sector of Decommissioning and Radioactive Waste Management has summarized the results of the decommissioning technology development and decommissioning of nuclear facilities which were carried out in the second medium-term plan.
Mimura, Ryuji; Muraguchi, Yoshinori; Nakashio, Nobuyuki; Nemoto, Koichi; Shiraishi, Kunio
Proceedings of 23rd International Conference on Nuclear Engineering (ICONE-23) (DVD-ROM), 5 Pages, 2015/05
The JAERI's Reprocessing Test Facility (JRTF) was the first engineering-scale reprocessing facility constructed in Japan. The JRTF was operated from 1968 to 1969 to reprocess spent fuels from the Japan Research Reactor No.3 (JRR-3). As a result of the operation (total 3 runs) by PUREX process, 200 g of highly purified plutonium (Pu) were extracted. In this operation, about 70 m of liquid waste was generated and part of this waste, which including Pu, with relatively high radioactivity, was stored in six large tanks. After shutdown of the facility, the JRTF decommissioning program was started in 1990 to develop decommissioning technologies and to obtain experiences and data on dismantling of fuel cycle facilities. Liquid waste in the tanks was treated from 1982 to 1998. Dismantling of tanks started in 2002. The tanks were installed in narrow concrete cells and inside of the cell was high dose area. Dismantling method for the tank is important factor to decide manpower and time for dismantlement. In this paper, in-situ dismantling of the liquid waste storage tank and its preparation work are discussed.
Sudo, Tomoyuki; Mimura, Ryuji; Ishihara, Keisuke; Satomi, Shinichi; Myodo, Masato; Momma, Toshiyuki; Kozawa, Kazushige
JAEA-Technology 2011-015, 24 Pages, 2011/06
The super compactor in the Advanced Volume Reduction Facilities (AVRF) treats metal wastes mainly generated from research reactors in the Nuclear Science Research Institute of JAEA. Those wastes are compacted from one third to one fourth with maximum 2,000-ton force. In the trial operation using simulated wastes, some technical problems were found to be improve for the stable operation. One problem is the motion mechanism for carrying wastes before and after compaction. The other problem is the mechanism for treating the irregular supercompacted products. In this report, we describe the detail and the result of improvement on those problems for the stable operation in the super compactor.
Sudo, Tomoyuki; Nakashio, Nobuyuki; Osugi, Takeshi; Mimura, Ryuji; Ishihara, Keisuke; Satomi, Shinichi; Myodo, Masato; Momma, Toshiyuki; Kozawa, Kazushige
JAEA-Technology 2010-041, 38 Pages, 2011/01
The super compactor in the AVRF treats compactible metal wastes mainly generated from research reactors in the Nuclear Science Research Institute of JAEA. Those wastes are compacted with the maximum about 2,000-ton force. The supercompacted wastes are packed into the container and then immobilized with cementitious materials. The solidified wastes (containing supercompacted wastes) become an object for near surface disposal with artificial barrier. For disposal, the solidified wastes must be satisfied the technical criteria. One of the important indicators is the void ratio in the solidified wastes. In this report, we manufactured the supercompacted wastes with the ordinary treatment method for actual wastes treated in the AVRF and immobilized with a mortar grout. The void ratio of the solidified wastes were evaluated in consideration for concrete vault disposal. As a result, We confirmed the integrity of the solidified wastes from a point of view of void ratio.
Okada, Takashi; Kawatsuma, Shinji; Fukushima, Mineo; Igarashi, Miyuki; Nakai, Koji; Mimura, Ryuji; Kanayama, Fumihiko
no journal, ,
Due to Tohoku Pacific Ocean earthquake and tsunami in 11 March in 2011, Tokyo Electric Power Co. Fukushima Daiichi Nuclear Power Station lost all power and has occurred accidents for failure of core cooling function. In Japan Atomic Energy Agency it was remodeled the nuclear disaster robot, was developed -ray visualization equipment and has been supporting the accident recovery. This paper is described the lessons learned from the supporting with the nuclear disaster robots and the -ray visualization equipment.
Kawatsuma, Shinji; Okada, Takashi; Fukushima, Mineo; Nakai, Koji; Mimura, Ryuji; Kanayama, Fumihiko
no journal, ,
no abstracts in English
Mimura, Ryuji; Kanayama, Fumihiko; Okada, Takashi; Kawatsuma, Shinji
no journal, ,
no abstracts in English
Mimura, Ryuji
no journal, ,
no abstracts in English
Osugi, Takeshi; Nakashio, Nobuyuki; Mimura, Ryuji; Nonaka, Kazuharu; Nakanishi, Yoshiki; Okoshi, Minoru; Tokizawa, Takayuki; Nakayama, Shinichi; Kimura, Takeshi*
no journal, ,
To reduce volume of wastes that consisted of plants and soil generated from decontamination works on farmland, we have produced a pilot-scale pyrolysis furnace by rotary kiln type and had some heat-treatment tests. In this reports, we shows some results of the tests on two kinds of paddy soils in Iitate-village.
Mimura, Ryuji; Okada, Takashi; Igarashi, Miyuki
no journal, ,
Introduce of radiation measurements and remote robot, about JAEA emergency response for Fukushima Dai-ichi Nuclear Power Plant accident.
Muraguchi, Yoshinori; Mimura, Ryuji; Nakashio, Nobuyuki; Nemoto, Koichi; Shiraishi, Kunio; Tachibana, Mitsuo
no journal, ,
For the purpose of the development of technology for dismantling and decontamination at the high dose area, dismantling method is applied for the liquid waste storage tank (LV-1) which is in the concrete cell at the JRTF. This report describes about the outline of preparatory works before dismantling and the data obtained from its works.
Nakashio, Nobuyuki; Mimura, Ryuji; Muraguchi, Yoshinori; Nemoto, Koichi; Shiraishi, Kunio; Tachibana, Mitsuo; Kubota, Shintaro; Kawagoshi, Hiroshi
no journal, ,
For the purpose of the development of technology for dismantling and decontamination at the high dose area, dismantling method is applied for the liquid waste storage tank (LV-1) which is in the concrete cell at the JRTF. This report describes the outline of the program for dismantling of the LV-1.
Kubota, Shintaro; Kawagoshi, Hiroshi; Tachibana, Mitsuo; Muraguchi, Yoshinori; Mimura, Ryuji; Nakashio, Nobuyuki; Nemoto, Koichi; Shiraishi, Kunio
no journal, ,
no abstracts in English
Nakashio, Nobuyuki; Muraguchi, Yoshinori; Mimura, Ryuji; Nemoto, Koichi; Shiraishi, Kunio
no journal, ,
no abstracts in English
Mimura, Ryuji; Muraguchi, Yoshinori; Nakashio, Nobuyuki; Nemoto, Koichi; Shiraishi, Kunio
no journal, ,
no abstracts in English
Arakawa, Yuto; Fujii, Katsutoshi; Mimura, Ryuji; Nakashio, Nobuyuki; Onuma, Isamu; Shishido, Nobuhito; Umehara, Takashi
no journal, ,
no abstracts in English
Kubota, Shintaro; Tachibana, Mitsuo; Mimura, Ryuji; Nemoto, Koichi; Shiraishi, Kunio
no journal, ,
no abstracts in English