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Nakagawa, Akinori; Oyokawa, Atsushi; Murakami, Masashi; Yoshida, Yukihiko; Sasaki, Toshiki; Okada, Shota; Nakata, Hisakazu; Sugaya, Toshikatsu; Sakai, Akihiro; Sakamoto, Yoshiaki
JAEA-Technology 2021-006, 186 Pages, 2021/06
Radioactive wastes generated from R&D activities have been stored in Japan Atomic Energy Agency. In order to reduce the risk of taking long time to process legacy wastes, countermeasures for acceleration of waste processing and disposal were studied. Work analysis of waste processing showed bottleneck processes, such as evaluation of radioactivity concentration, segregation of hazardous and combustibles materials. Concerning evaluation of radioactivity concentration, a radiological characterization method using a scaling factor and a nondestructive gamma-ray measurement should be developed. The number of radionuclides that are to be selected for the safety assessment of the trench type disposal facility can decrease using artificial barriers. Hazardous materials, will be identified using records and nondestructive inspection. The waste identified as hazardous will be unpacked and segregated. Preliminary calculations of waste acceptance criteria of hazardous material concentrations were conducted based on environmental standards in groundwater. The total volume of the combustibles will be evaluated using nondestructive inspection. The waste that does not comply with the waste acceptance criteria should be mixed with low combustible material waste such as dismantling concrete waste in order to satisfy the waste acceptance criteria on a disposal facility average. It was estimated that segregation throughput of compressed waste should be increased about 5 times more than conventional method by applying the countermeasures. Further study and technology development will be conducted to realize the plan.
Sato, Kazuhiko; Yagi, Naoto; Nakagiri, Toshio
Proceedings of 27th International Conference on Nuclear Engineering (ICONE-27) (Internet), 6 Pages, 2019/05
no abstracts in English
Hagiwara, Shigeru*; Sakamoto, Yoshiaki; Takebe, Shinichi; Ogawa, Hiromichi; Nakayama, Shinichi
JAERI-Review 2002-038, 107 Pages, 2002/12
For the disposal of radioactive waste arising from radioactive utilization facilities and nuclear facilities, it is necessary to establish the disposal system in proportion to half-lives of radionuclides and radioactivity concentration in the waste. It is important to grasp the features of the earth scientific phenomena and geological structure of our country for the disposal system of radioactive waste. Then, for the porpose of the survey of the geological characteristics around the Japanese Islands whole neiborhood, the earth scientific phenomena at present, geological structure and geotectonic history were summarized on the basis of the existing literatures.
5th NUCEF Seminar Working Group
JAERI-Conf 2001-015, 92 Pages, 2001/12
no abstracts in English
4th NUCEF Seminar Working Group
JAERI-Conf 2000-012, 52 Pages, 2000/07
no abstracts in English
JAERI-Conf 98-010, 47 Pages, 1998/06
no abstracts in English
JAERI-Conf 97-002, 28 Pages, 1997/02
no abstracts in English
Nenryo Kyokai-Shi, 54(577), p.306 - 313, 1975/00
no abstracts in English
; ; ; ; ;
JAERI-M 5903, 82 Pages, 1974/11
no abstracts in English
; *
Genshiryoku Kogyo, 20(1), p.25 - 32, 1974/01
no abstracts in English
Meguro, Yoshihiro; Kato, Jun; Kishimoto, Katsumi; Kameo, Yutaka; Ishimori, Kenichiro; Tanaka, Kiwamu; Shibata, Atsuhiro; Koma, Yoshikazu; Ashida, Takashi
no journal, ,
The authors are working in study for radioactive wastes generated in Fukushima Daiichi. Radioactive inventory estimation of wastes is important in the study for the processing and disposal of radioactive waste. And then so many real wastes have to be analyzed for their inventory evaluation. In addition to this waste analysis, there are several needs for analysis. For example a large volume of the contaminated water is being decontaminated, and operational status and ability of this system should be checked by analysis of the treated water. And also groundwater and sea water are analyzing to understand contaminated situation, to estimate a leakage position, and to confirm leakage prevention. In future fuel debris will be analyzed for its material accountancy. In this presentation, actual situation of analyses in Fukushima Daiichi will be explained, mainly focus on analyses for the inventory evaluation of the radioactive waste.
Meguro, Yoshihiro
no journal, ,
Research and development for the processing and disposal of all radioactive wastes that were generated or will be generated in Fukushima Daiichi Nuclear Power Station is promoted. Here characterization of the wastes, safety assessment of long-term storage of the waste, waste stream, conditioning of the waste using existing techniques, evaluation of effect of uncertainty in the waste information on the safety evaluation of waste disposal have been investigated.
Meguro, Yoshihiro; Sato, Junya; Kato, Jun; Nakagawa, Akinori; Koma, Yoshikazu; Ashida, Takashi
no journal, ,
A large quantity of contaminated water is accumulated in nuclear reactor buildings in Fukushima Daiichi Nuclear Power Station. Because various radionuclides are dissolved in the accumulated water, several decontamination devices based on deposition and adsorption are used for the decontamination. Therefore, several sludge and used adsorption materials are generated. These most are different from wastes caused by the operation of commercial nuclear power stations so far in properties, and these have not been disposed of commercially. As then feasibility of conventional solidification techniques to the wastes should be investigated prior to selection of solidification technique of the wastes. In this study as a first step of feasibility study, three types of sludge and three absorbents were solidified using cement materials and solidification behavior and properties of solidified material were investigated, and then feasibility of cementation to these wastes was evaluated.
Saito, Tatsuo
no journal, ,
RI waste (waste from research facilities, etc. contaminated with RI) is collected and processed by the Japan Radioisotope Association, but there are no burial facilities, and it continues to be stored. JAEA is positioned by the JAEA Law as the entity responsible for the disposal of RI waste. Currently, JAEA is developing waste acceptance criteria and technical studies for the basic design of a burial facility, and is promoting activities to promote understanding of wastes from research facilities as a response to the siting of a burial facility. With the cooperation of waste generators, JAEA will continue to develop waste acceptance criteria and study the basic design of the burial facility and promote activities for understanding of the burial of wastes from research facilities.