Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Iwamura, Toko; Nakata, Hisakazu; Maekawa, Keisuke; Sakai, Akihiro; Sakamoto, Yoshiaki
JAEA-Review 2024-032, 39 Pages, 2024/09
Japan Atomic Energy Agency (JAEA) is responsible for the disposal of low-level radioactive waste generated by JAEA itself and research facilities under the revised JAEA Act of 2008 and subsequently developed a "Plan for the Implementation of Disposal Operations" (implementation plan) in 2009. Furthermore, based on the results of the survey on the amount of waste generated by research facilities, the quantity of wastes for the near surface disposal was set at 600,000 in terms of 200L drums, and the results of the consideration on the conceptual design of the disposal facility were summarized in 2012. In 2018 JAEA published its long-term outlook and policy regarding back-end measures in "Back-end Roadmap", and in this "Back-end Roadmap", the amount of waste generated by JAEA was also organized and published. Therefore, the amount of waste materials from waste generators outside JAEA was re-examined, and as a result, the size of the burial facility was changed from 600,000 to 750,000 in terms of 200L drums, and approval was obtained for a change in the implementation plan. In addition, the conceptual design of the disposal facility was revised to accommodate the increased size of the facility. This report summarizes the results of the updated assumptions and disposal facility design from the 2012 conceptual design.
Nishihara, Tetsuo; Sakaki, Akihiro*; Inagaki, Yoshiyuki; Takami, Kazuo*
Nihon Genshiryoku Gakkai Wabun Rombunshi, 3(4), p.381 - 387, 2004/12
JAERI has been carried out research and development on the HTTR hydrogen production system. One of the key components in this system is a high temperature isolation valve (HTIV) installed on the hot helium gas piping penetrating the reactor containment vessel. Angle valve with inner thermal insulator was selected for HTIV and conceptual design was performed. The structural integrity of HTIV was clarified by the stress analyses. Allowable helium leak rate of HTIV was discussed. Helium leak tests using small-scaled valve seat models were performed to decide the seat surface shape and valve closing force. The test results show that the leak rate of wedge shape seat increased in proportion to the number of simulated temperature and stress cycles loaded on the seat models before helium leak test, however that of flat seat did not depend on the number of cycles. So flat seat is adopted for HTIV. It was found that the seat closing force of 30 MPa is reasonable to meet the allowable helium leak rate.
Sakai, Akihiro; Yoshimori, Michiro; Okoshi, Minoru; Yamamoto, Tadatoshi; Abe, Masayoshi
JAERI-Tech 2001-018, 88 Pages, 2001/03
no abstracts in English
Yabuuchi, Noriaki; Takahashi, Masao*; Nakazawa, Toshio; Sato, Kazuo*; Shimazaki, Junya; Ochiai, Masaaki
JAERI-Research 2000-063, 69 Pages, 2001/02
no abstracts in English
Kusunoki, Tsuyoshi; Odano, Naoteru; Nakajima, Nobuya; Fukuhara, Yoshifumi*; Ochiai, Masaaki
Nihon Genshiryoku Gakkai-Shi, 42(11), p.1195 - 1203, 2000/11
Times Cited Count:0 Percentile:0.01(Nuclear Science & Technology)no abstracts in English
Nibe, Nobuaki; Shimakawa, Yoshio; ; Hayafune, Hiroki; ; ;
JNC TN9400 2000-074, 388 Pages, 2000/06
Large sized sodium-cooled fast breeder reactors of large-size are being studied and have been operated in Japan and many countries. ln this feasibility study, evaluation was made on technical feasibinty for design concepts or 1 loop type and 3 pool types, specially from the viewpoint of improvement of economical competence. The design concepts include the ideas of cost reduction measures such as large-scaled components, reduction of loop number and integration of components on the basic of utilization of sodium characteristics. From the results of the evaluation, it may be possible for all the concepts to attain the economical target of 200 thousands yen per kilowatt, though further confirmation should be made for technical feasibility of those concepts. ln addition, the following items were listed up as further cost-reduction measures. (1)Higher temperature cooling system and steam cycle efficiency (2)Shortening of construction term (3)Reduction of safety systems by using measuring instruments with high performmce (4)Adoption of SG-ACS
; ; ;
JNC TN8410 2000-011, 175 Pages, 2000/05
This report describes the neutronic design calculational methods used in Fuel Design and Evaluation Group in order to inform other related sections of FBR core analysis technology and hand down the technology. Especially we show the neutronics calculation procedures used for the conceptual design study of the advanced core with 127 pin bundle for MONJU that has been carried out in our group. The topics include effective cross section preparation calculations, two-dimensional depletion calculations, three-dimensional diffusion calculations, reactivity coefficient calculations, and control rod worth calculations. The calculational methods shown in this report are the standard neutronics calculation methods employed in our group at the moment. However, the improvement of calculation codes, the reduction of correction factors and uncertainties for design using the nuclear data obtained in the start-up test for MONJU and so on, and the update of nuclear data file will be planned in order to improve evaluation accuracies. Those may change the neutronic design calculational methods, but we decided to describe the present standard calculational methods in our group from the viewpoint of sharing information in JNC.
Kofuji, Hirohide; ; ; ;
JNC TN9400 2000-055, 49 Pages, 2000/03
Accompanying with the progress of the "Feasibility study on FBR cycle system; FS" , various kinds of technical information, facility design parameters, and related data will be obtained and they should be stored in data bases and be used as fundamental data for the FS. So the several data bases are going to be set up at each section and controlled by the management system through a local area network. Among above data bases, a prototype of FBR cycle data base that will record data for FBR scenario study and synthetic assessment is to be completed in. Phase l by fiscal year 2000, so the data base system concept has been examined in the current fiscal year, 1999. As the results of the system concept examination, two types of prototypes have been selected, one is to be set up as the data table containing digital data that are extracted from technical papers, another is as image data of papers with index information. Referring to examples of data bases in other companies, it was kept in mind to use a package software for general purpose and to utilize data existing now.
Shinohara, Yoshinori*; Tsujimoto, Keiichi*
JNC TJ1400 2000-002, 280 Pages, 2000/02
no abstracts in English
Shinohara, Yoshinori*; Tsujimoto, Keiichi*
JNC TJ1400 2000-001, 137 Pages, 2000/02
no abstracts in English
; ; Tanai, Kenji
JNC TN8400 99-050, 94 Pages, 1999/11
This paper reports on the evaluations of operational activities for a High Level Radioactive Wastes Disposal Facility, from initial acceptance of vitrified waste at a surface facility to emplacement engineered barriers in underground facilities. The purpose of this analysis is to confirm the technical feasibility of geological disposal. First, the basic design and repository system requirements are identified. Second, operational activities in surface facilities, access facilities and underground facilities are described. The required procedures and equipment, suitable for specific emplacement concepts and configurations for engineered barrier systems are discussed for specific examples. Countermeasures for potential adverse events or conditions are based on extensive civil engineering and mining experiences in Japan and abroad. The time schedule is also evaluated on the basis of these concepts. In addition, the concept of stationary and mobile radiation control areas is studied based on experiences and practice in current nuclear facilities. Finally future research and development items are summarized.
Nishihara, Tetsuo; Iwatsuki, Jin*
JAERI-Tech 99-078, p.55 - 0, 1999/11
no abstracts in English
Aoki, Isao; Seki, Yasushi; ; ; Kim, Y.*
JAERI-Data/Code 99-004, 136 Pages, 1999/02
no abstracts in English
Okubo, Tsutomu; Kugo, Teruhiko; ; Shimada, Shoichiro*; Ochiai, Masaaki
Proc. of Workshop on Advanced Reactors with Innovative Fuels, p.127 - 137, 1998/10
no abstracts in English
Honda, Yoichiro*; Hasegawa, Kazuo; Ouchi, Nobuo; Kusano, Joichi; ; Mizumoto, Motoharu
JAERI-Tech 98-040, 77 Pages, 1998/09
no abstracts in English