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Izumo, Sari; Hayashi, Hirokazu; Nakata, Hisakazu; Amazawa, Hiroya; Motoyama, Mitsushi*; Sakai, Akihiro
JAEA-Technology 2018-018, 39 Pages, 2019/03
JAEA-Technology-2018-018.pdf:2.8MB
JAEA has planed the near surface disposal of LLW generated from research, industrial, and medical facilities. Maximum radioactivity concentration of each waste and total radioactivity of disposed wastes are needed to be less than the permitted values in the license of disposal facility. Thus, it is important not to evaluate the radioactivity of each waste in unduly conservative ways so as to dispose of the total amount of the waste that is originally planned. Accordingly, the detection limit is required to be as low as the clearance level for the very low level radioactive waste planned to be disposed of trench-type. In this report, the feasibility of the non-destructive assay method is studied by model calculations for gamma emitters. It is confirmed that the detection limit less than the clearance level can be achieved as regards the box type metal container that is difficult to measure. This report summarizes the requirements for the non-destructive measuring equipment.
Nakata, Hisakazu; Takao, Hajime*; Chijimatsu, Masakazu*; Noma, Yasutaka*; Amazawa, Hiroya; Sakai, Akihiro
JAEA-Technology 2018-014, 43 Pages, 2019/03
JAEA-Technology-2018-014.pdf:5.91MB
Japan Atomic Energy Agency plans to install disposal facilities for radioactive waste arising from research institutes. One relevant technical standard by the safety regulation is that the disposal facility shall be performance so as not to be left with harmful voids after backfilling with soil. Additionally no harmful void needs to exist in the waste packed in metal containers. The harmful void is supposed to result in the collapse of the disposal facility after structural materials of the container deteriorate and then become a state that can not retain the structure on its own. That leads to have an adverse impact on the facility such that the shape of cover soil deforms the way in which stagnant water is likely to occure. For which reason, a waste acceptance criteria relating to the quantity of voidage in a waste package needs to be defined quantitatively, which is preliminary less than 20% in a volum ratio based on this study.
Nakata, Hisakazu; Amazawa, Hiroya; Izumo, Sari; Okada, Shota; Sakai, Akihiro
Dekomisshoningu Giho, (58), p.10 - 23, 2018/09
Low level radioactive wastes are generated in the research and development of the nuclear energy, medical and industrial use of radioisotope except NPP in Japan. The disposal of wastes arising from NPP has already been implemented while not the one for wastes from research institutes etc. Japan Atomic Energy Agency therefore has been assigned an implementing organization for the disposal legally in 2008 in order to promote the disposal program as quickly and firmly as possible. Since then, JAEA has conducted their activity relating to the disposal facility design on generic site conditions and developing Waste Acceptance Criteria for LLW from research institutes. This report summarizes the WAC and current challenges.
Waste Technical Standards Working Group
JAEA-Review 2017-017, 112 Pages, 2017/11
JAEA-Review-2017-017.pdf:2.87MB
In Japan Atomic Energy Agency, JAEA, a Waste Technical Standards Working Group has established since FY2015. The Working Group is composed of the members from waste management sections in each site in JAEA and from Radioactive Waste Management and Disposal Project Department. In this Working Group, we discussed quality management on conditioning waste packages, methodologies to evaluate the radioactivity concentration and measures for dismantling waste. This annual report summarizes the results of discussion in FY2016.
Waste Technical Standards Working Group
JAEA-Review 2016-020, 61 Pages, 2016/09
JAEA-Review-2016-020.pdf:1.55MB
Radioactive Waste Management and Disposal Project Department has set up a Working Group for the purpose of sharing information within the Sector of Decommissioning and Radioactive Wastes Management of Japan Atomic Energy Agency, heading towards implementation of disposal of low level radioactive waste generated from research, medical and industrial facilities. Waste package quantities and its radioactivity inventory which are needed for disposal project planning and facility design, as well as methods for corresponding to the technical standards on confirmation related to waste disposal, radioactivity evaluation techniques and quality control methods have been addressed in the Working Group. This annual report summarizes the activities of the Working Group in the FY 2015 regarding quality management system related to the manufacturing of the waste packages, standard manual for radioactivity data acquisition of JAEA and future issues on the basis of the results by 2014.
Saito, Tatsuo; Nakata, Hisakazu; Kamei, Gento
no journal, ,
Research on nuclear power and radiation is utilized in various fields such as medicine, industry and agriculture, in addition to the energy field, and supports our daily life. In order to make these efforts sustainable in the future, JAEA is working toward the establishment of a burial facility as an implementing entity of the domestic LLW generated in research, medical and industrial facilities, in accordance with the JAEA Law and the national basic policy (2008) based on this law. JAEA is committed to the following basic policies (1) Ensure safety, (2) Ensure transparency and confidence in the project, (3) Promote understanding and coexistence with the local community, (4) Ensure reasonable burden and cooperation from the waste generators, and (5) Implement reasonable disposal practices.