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Negishi, Hitoshi; Kamide, Hideki; Maeda, Seiichiro; Nakamura, Hirofumi; Abe, Tomoyuki
Nihon Genshiryoku Gakkai-Shi ATOMO
, 62(8), p.438 - 441, 2020/08
Prototype Fast Breeder Reactor, Monju, was under decommission since April, 2018. It is the first time for Japan to make a sodium cooled reactor into decommission. It is significant work and will take 30 years. The Monju has provided wide spectrum and huge amount of findings and knowledge, e.g., design, R&D, manufacturing, construction, and operation up to 40% of full power over 50 years of development history. It is significant to utilize such findings and knowledge for the development and commercialization of a fast rector in Japan.
Ieda, Yoshiaki; Ono, Kiyoshi; Negishi, Hitoshi; Shiotani, Hiroki; Nagaoki, Yoshihiro; Namba, Takashi
Proceedings of International Conference on Toward and Over the Fukushima Daiichi Accident (GLOBAL 2011) (CD-ROM), 9 Pages, 2011/12
Since 1999, Japan Atomic Energy Agency (JAEA) has promoted R&D of the Fast Breeder Reactor Cycle in order to build the practical concepts and establish the technical systems, in cooperation with related entities. In the first 5-year of the Fast Reactor Cycle System Technology Development Project (FaCT), namely the FaCT phase1 (JFY2006-2010), the evaluation of the achievement degree to the performance target fixed by the Atomic Energy Commission and the adoption judgment of the innovative technology at present were carried out with "Sodium-cooled Fast Reactor with MOX fuel, advanced aqueous reprocessing process, and simplified MOX pellet fabrication process". FaCT phase1 moved forward almost smoothly and confirmed that the project will be able to enter the next phase to demonstrate the innovative technology by the engineering scale examination. The concrete results of the FaCT phase1 and future direction are introduced in the full paper.
Negishi, Hitoshi; Kotake, Shoji; Niwa, Hajime
Nihon Genshiryoku Gakkai-Shi ATOMO, 50(3), p.174 - 180, 2008/03
Based on the experience of R&D results, such as the developing the prototype FBR, "MONJU," and related fuel cycle, the Japan Atomic Energy Agency carried out the joint study "Feasibility Study on Commercialized Fast Reactor Cycle Systems" with electric utilities, the Central Research Institute of Electric Power Industry and manufacturers. This study has two objectives, presenting "an appropriate concept of the commercial FBR cycle system" and "the R&D programs for commercialization", toward 2015. The "Combined system of sodium-cooled reactor (MOX fuel), advanced aqueous reprocessing and simplified pelletizing fuel fabrication" was selected, as the concept to be developed mainly from now, because it has the greatest potential conformity to the development requirements and has the high technical feasibility because it uses the accumulated results of past R&D, and international cooperation in this is possible.
Negishi, Hitoshi; Chatani, Keiji; Tanigawa, Shingo
Genshiryoku Nenkan 2008, p.53 - 61, 2007/09
The Japanese government assessed the result of "Feasibility Study on Commercialized FR Cycle System 2nd Phase" and a major concept that is the combination of a sodium cooled FBR (oxide fuel), an advanced aqueous reprocessing and a simplified pelletizing was selected. From now on, the JAEA invests the development resource to a major concept intensively, and aims to put it to practical use by new project, "FaCT". In "Monju", the plant improvement construction have been working on schedule, and the various tests for restart are advanced. The R&D results in "Monju" will be applied to FBR development near future. "Joyo" has been operated over 70,000 hours, and has provided the fields to develop FBR fuel & material. In addition, the external utilization of "Joyo" is enhancing now. FBR development is activating worldwide. The international cooperation under GIF, GNEP and INPRO and the research collaboration with America/France are carrying.
Ono, Katsumi; masato, ando; Kotake, Shoji; Nagaoki, Yoshihiro; Namba, Takashi; Kato, Atsushi; Nakai, Ryodai; Negishi, Hitoshi
Nihon Genshiryoku Gakkai-Shi, 46(10), 685 Pages, 2004/10
A panoramic sensitivity analysis approach based on a statistic sampling method has been developed and applied for preliminary analysis on geological disposal of TRU waste considering variety of geological conditions and uncertainty. This approach can identify the parameters with the high importance for safety assessment and can extract the successful conditions for safety geological disposal.
Takei, Akihiko*; Owada, Hitoshi*; Fujita, Hideki*; Negishi, Kumi*; Hibiya, Keisuke*; Yokozeki, Kosuke*; Watanabe, Kenzo*
JNC TJ8400 2003-047, 120 Pages, 2003/02
JNC-TJ8400-2003-047.pdf:4.46MB
We acquired the water permeation properties and also mechanical characteristics of the altered specimen that produced by permeation or immersing as the fundamental data.
Takei, Akihiko*; Owada, Hitoshi*; Fujita, Hideki*; Negishi, Kumi*; Hibiya, Keisuke*; Yokozeki, Kosuke*; Watanabe, Kenzo*
JNC TJ8400 2003-046, 282 Pages, 2003/02
JNC-TJ8400-2003-046.pdf:8.26MB
We acquired the water permeation properties and also mechanical characteristics of the altered specimen that produced by permeation or immersing as the fundamental data.
Takei, Akihiko*; Owada, Hitoshi*; Fujita, Hideki*; Negishi, Kumi*
JNC TJ8400 2003-042, 67 Pages, 2003/02
TRU waste includes various chemical compounds such as nitrates. The influence of the chemical compounds on the performance of the barrier system should be estimated. In this study, we estimated the influence of sodium nitrate and also that of the chemical compounds derived from the sodium nitrate to the degradation of the cementitious material. 1) Evaluation of the influence of nitrate ion on the alteration of the cementitious material Alteration of characteristics of cementitious material was evaluated by the water permeation test using sodium nitrate solution. The calcium concentration of sodium nitrate solution permeated sample was higher than that of blank. The result indicates that sodium nitrate solution will accelerate the alteration of cementitious material. the permeation test was continued by using the ion-exchanged water as the permeation-water. As the results, the chemical and physical characteristics of the samples approached to those of blanks.2) Evaluation of the influence of ammonia on the alteration of the cementitious material Alteration of characteristics of cementitious material in nitrate and ammonia solution was evaluated by the water permeation test using 1mol/liter-sodium-nitrate and 0.5mol/liter-ammonia solution (denoted as NH-solution in the following). The calcium concentration of NH-solution permeated sample was higher than that of blank and the value of the calcium concentration was almost the same as that of the sodium nitrate solution case. The alteration range by the calcium leaching of the solid phase of the NH-solution case shows similar trend to that of the sodium nitrate solution case. The acceleration of the calcium dissolution was considered from this result. And the change of the water-permeability indicated the same trend with sodium-nitrate-solution case. From these results we confirmed that ammonia solution would not influence the alteration of cementitious solution.
Takei, Akihiko*; Owada, Hitoshi*; Fujita, Hideki*; Negishi, Kumi*
JNC TJ8400 2003-041, 152 Pages, 2003/02
JNC-TJ8400-2003-041.pdf:7.93MB
TRU waste includes various chemical compounds such as nitrates. The influence of the chemical compounds on the performance of the barrier system should be estimated. In this study, we estimated the influence of sodium nitrate and also that of the chemical compounds derived from the sodium nitrate to the degradation of the cementitious material. 1) Evaluation of the influence of nitrate ion on the alteration of the cementitious material Alteration of characteristics of cementitious material was evaluated by the water permeation test using sodium nitrate solution. The calcium concentration of sodium nitrate solution permeated sample was higher than that of blank. The result indicates that sodium nitrate solution will accelerate the alteration of cementitious material. the permeation test was continued by using the ion-exchanged water as the permeation-water. As the results, the chemical and physical characteristics of the samples approached to those of blanks. 2) Evaluation of the influence of ammonia on the alteration of the cementitious material Alteration of characteristics of cementitious material in nitrate and ammonia solution was evaluated by the water permeation test using 1mol/liter-sodium-nitrate and 0.5mol/liter-ammonia solution (denoted as NH-solution in the following). The calcium concentration of NH-solution permeated sample was higher than that of blank and the value of the calcium concentration was almost the same as that of the sodium nitrate solution case. The alteration range by the calcium leaching of the solid phase of the NH-solution case shows similar trend to that of the sodium nitrate solution case. The acceleration of the calcium dissolution was considered from this result. And the change of the water-permeability indicated the same trend with sodium-nitrate-solution case. From these results we confirmed that ammonia solution would not influence the alteration of cementitious solution.
Negishi, Hitoshi; Sagayama, Yutaka; Sato, Kazujiro; ; Nakai, Ryodai; Ieda, Yoshiaki
Saikuru Kiko Giho, (20), 0 Pages, 2003/00
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Negishi, Hitoshi; ; ; ; Sato, Kazujiro; Ieda, Yoshiaki
Saikuru Kiko Giho, (16), p.1 - 12, 2002/09
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Tsukimori, Kazuyuki; Negishi, Hitoshi
Nuclear Engineering and Design, 213(2-3), p.141 - 156, 2002/00
Times Cited Count：1 Percentile：9.76(Nuclear Science & Technology)None
Uto, Nariaki; Tsukimori, Kazuyuki; Negishi, Hitoshi; ; Sugaya, Toshio; Sakai, Takaaki
SNS2000, 16 Pages, 2000/00
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Tsukimori, Kazuyuki; Negishi, Hitoshi
Transactions of 15th International Conference on Structural Mechanics in Reactor Technology (SMiRT-15), 4, p.217 - 224, 1999/00
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