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Nakata, Hisakazu
Genkan Senta Topikkusu, (147), p.4 - 11, 2023/10
no abstracts in English
Sakai, Akihiro; Kamei, Gento; Sakamoto, Yoshiaki
Nihon Genshiryoku Gakkai-Shi ATOMO
, 65(1), p.25 - 29, 2023/01
Currently, radioactive waste generated from research institutes, etc. is keeping in storage facilities without being disposed of. In order to solve this problem, the Japan Atomic Energy Agency (JAEA) is proceeding with the project for concrete-pit disposal and trench disposal of these waste. This paper introduces the characteristics of the waste and disposal facilities planned by the JAEA, as well as the status of development of the siting criteria for the disposal facility.
Sakai, Akihiro
Genshiryoku Bakkuendo Kenkyu (CD-ROM), 29(1), p.48 - 54, 2022/06
no abstracts in English
Asakura, Kazuki; Shimomura, Yusuke; Donomae, Yasushi; Abe, Kazuyuki; Kitamura, Ryoichi; Miyakoshi, Hiroyuki; Takamatsu, Misao; Sakamoto, Naoki; Isozaki, Ryosuke; Onishi, Takashi; et al.
JAEA-Review 2021-020, 42 Pages, 2021/10
JAEA-Review-2021-020.pdf:2.95MB
The disposal of radioactive waste from the research facility need to calculate from the radioactivity concentration that based on variously nuclear fuels and materials. In Japan Atomic Energy Agency Oarai Research and Development Institute, the study on considering disposal is being advanced among the facilities which generate radioactive waste as well as the facilities which process radioactive waste. This report summarizes a study result in FY2020 about the evaluation method to determine the radioactivity concentration in radioactive waste on Oarai Research and Development Institute.
Asakura, Kazuki; Shimomura, Yusuke; Donomae, Yasushi; Abe, Kazuyuki; Kitamura, Ryoichi
JAEA-Review 2020-015, 66 Pages, 2020/09
JAEA-Review-2020-015.pdf:4.27MB
The disposal of radioactive waste from the research facility need to calculated from the radioactivity concentration that based on variously nuclear fuels and materials. In Japan Atomic Energy Oarai Research and Development Institute, the study on considering disposal is being advanced among the facilities which generate radioactive waste as well as the facilities which process radioactive waste. This report summarizes a study result in FY2019 about the evaluation method to determine the radioactivity concentration in radioactive waste on Oarai Research and Development Institute.
Sakamoto, Yoshiaki
Genshiryoku Bakkuendo Kenkyu (CD-ROM), 26(2), p.127 - 132, 2019/12
JAEA has promoted near surface disposal project for low-level radioactive wastes generated from research, industrial and medical facilities after receiving project approval from the government in 2009. This kind of low level radioactive wastes which were arising from the 1940s are still keeping in each storage buildings. For immediate treatment and disposal of the wastes, technical issue and commercialization of the disposal project are studied by JAEA. The outline of current status of the disposal project of JAEA and some approach to push forward rational treatment and disposal system are presented.
Sakamoto, Yoshiaki
Genshiryoku Bakkuendo Kenkyu (CD-ROM), 24(2), p.141 - 146, 2017/12
Some research reactors are under decommissioning or preparation for application of decommissioning license for regulation authority in our country. The reasonable treatment and disposal of dismantling waste is important for decommissioning of research reactors. Therefore, in this paper, JAEA's approach of the treatment and disposal of dismantling waste was introduced from the point of view of disposal of low level radioactive waste arising from research, industrial and medical facilities.
Sakai, Akihiro; Nakata, Hisakazu; Amazawa, Hiroya; Kurosawa, Ryohei*; Sato, Makoto*; Kitamura, Yoichi*
no journal, ,
We consider that very low level waste slightly including chemical toxicity material among radioactive waste generated from research, industrial and medical facilities is disposed of in trench disposal facility which is equipped with impermeable layers. We studied the impermeable system which has high performance to prevent the radioactive material from leaching out of waste layer taking into account the combination of geomembrane liners and low permeable materials.
Nakata, Hisakazu; Sakai, Akihiro; Amazawa, Hiroya; Sakamoto, Yoshiaki
no journal, ,
Removed soil except those that may be reusable/recyclable would be finally disposed of. A general view is obtained in regards to a disposal concept of low level radioactive wastes generated from research, industrial and medical facilities, for the purpose of contributing to designing final disposal facilities of removed soil. It is analyzed to investigate the issues related to cost evaluation in order to reasonably carry out that design, referring to a cost evaluation methodology applied to a trench-type disposal facility, which has been planned by JAEA, with impermeable layers.
Shimomura, Yusuke; Kochiyama, Mami; Haraga, Tomoko; Ishimori, Kenichiro; Kameo, Yutaka
no journal, ,
no abstracts in English
Hayashi, Hirokazu; Izumo, Sari; Nakata, Hisakazu; Tsuji, Tomoyuki; Amazawa, Hiroya; Sakai, Akihiro
no journal, ,
no abstracts in English
Nakata, Hisakazu; Hayashi, Hirokazu; Amazawa, Hiroya; Sakai, Akihiro
no journal, ,
no abstracts in English
Izumo, Sari; Hayashi, Hirokazu; Nakata, Hisakazu; Kameo, Yutaka; Amazawa, Hiroya; Sakai, Akihiro
no journal, ,
no abstracts in English
Sakai, Akihiro
no journal, ,
Plan of disposal of LLW generated from research facilities and recent topics of technical development of the disposal are explained. At first, regarding the radioactivity evaluation of waste, a study about the reduction of the number of important nuclides by the method that enhances the safety functions of the trench disposal facility is introduced. The installation of impermeable layers and sorption layers in order to reduce the leaching of nuclides and the installation of a cover structure with resistance to human intrusion into the waste layer are examined as the safety functions. Then, regarding the design and operation of trench disposal facilities, a measure that increase the slope angle of the cover soil beforehand is explained in order to prevent the cover soil from settlement caused by voids in the waste containers at the trench disposal facility. We will continue to study the specific design of trench disposal facilities to realize the measures to these issues.
Nakata, Hisakazu
no journal, ,
Low level radioactive wastes are generated from the research and development of the nuclear energy, medical and industrial use of radioisotope in Japan. Almost all the wastes are still in storage without conditioning and/or treatment suitable for final disposal. The total amount of the waste is estimated approximately 590,000 drums. In order to promote the disposal project for the waste generated from both JAEA and others, JAEA has become its implementing organization in 2008. Since then, JAEA carried out preliminary design of near surface disposal facilities under generic site conditions and estimated the total project cost to accommodate the waste quantity to be required; 750,000 drums. In addition, site selection plans and technical studies in designing disposal facilities are also being discussed. In this report, it explains technical studies relating to Waste Acceptance Criteria for supporting appropriate waste conditioning and its planned implementation by the generators.
Hayashi, Hirokazu
no journal, ,
In the seminar on evaluating the radioactivity of wastes subject to near surface pit and trench disposal, the lecturer will report on the study of a common method for evaluating the radioactivity of wastes from research facilities in JAEA, as one of the method for confirmation related to waste package by the regulator.
Sakai, Akihiro
no journal, ,
no abstracts in English
Saito, Tatsuo
no journal, ,
RI waste is generated from the use of RI in universities, medical care, and research institutes, and from the dismantling of facilities, but it has not yet been finally disposed of for burial. Therefore, JAEA has been acting as an implementing agency for the disposal project of low-level radioactive wastes (wastes from research facilities, etc.), including RI wastes generated from research institutes, universities, and medical institutions, including JAEA. In order to obtain the understanding and cooperation of waste generators toward the early commencement of the disposal project, this report introduces the current status of the disposal of RI waste and the efforts being made for its burial.
Sakai, Akihiro
no journal, ,
no abstracts in English
Nakata, Hisakazu; Izumo, Sari; Amazawa, Hiroya; Sakai, Akihiro
no journal, ,
JAEA is working toward the establishment of disposal facilities for waste from research facilities in Japan, in accordance with the Law and the government's basic policy (2008). For burial disposal, it is necessary to make burial waste that meet the acceptance criteria for safety. This report presents the results of tests conducted to confirm the method meeting the waste acceptance criteria for voids as for trench disposal.
