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Kureta, Masatoshi; Akimoto, Hajime
Nuclear Technology, 143(1), p.89 - 100, 2003/07
Times Cited Count:10 Percentile:56.43(Nuclear Science & Technology)no abstracts in English
Kureta, Masatoshi; Akimoto, Hajime
Nihon Kikai Gakkai Rombunshu, B, 69(682), p.1469 - 1476, 2003/06
no abstracts in English
Nakano, Yoshihiro; Ishikawa, Nobuyuki; Nakatsuka, Toru; Iwamura, Takamichi
JAERI-Conf 2002-012, 219 Pages, 2002/12
no abstracts in English
Kureta, Masatoshi
JAERI-Conf 2002-012, p.47 - 52, 2002/12
no abstracts in English
Okubo, Tsutomu; Suzuki, Motoe; Iwamura, Takamichi; Takeda, Renzo*; Moriya, Kumiaki*; Kanno, Minoru*
Proceedings of International Conference on the New Frontiers of Nuclear Technology; Reactor Physics, Safety and High-Performance Computing (PHYSOR 2002) (CD-ROM), 10 Pages, 2002/10
A small scale around 300 MWe reduced-moderation water reactor (RMWR) concept has been developed. For the core, a BWR type core concept with the tight-lattice fuel rod arrangement and the high void fraction is adopted to attain a high conversion ratio over 1.0. The negative void reactivity coefficients are also required, and the very flat short core concept is adopted to make the natural circulation cooling (NC) possible. The core burn-up of 60 GWd/t and the operation cycle of 24 months are also attained. For the system, simplification of the system with the passive safety features is a basic approach to overcome the scale demerit as well as the NC. For example, the HPCF system is replaced with the passive accumulator system resulting in the expensive emergency DGs reduction. The cost evaluation for concerned NSSS components gives about 20% reduction. Since MOX fuels in the RMWR contains Pu around 30 wt% and is irradiated to a high burn-up, the fuel safety evaluation has been performed and the acceptable results have been obtained from the thermal feasibility point of view.
Okubo, Tsutomu; Iwamura, Takamichi; Yamamoto, Kazuhiko*; Okada, Hiroyuki*
Nihon Kikai Gakkai Dai-8-Kai Doryoku, Enerugi Gijutsu Shimpojiumu Koen Rombunshu, p.571 - 574, 2002/00
Based on the experienced light water reactor technology, conceptual design studies on advanced water-cooled reactors have been performed. They are named “Reduced-Moderation Water Reactor" (RMWR) with the high conversion ratio more than 1.0 and the negative void reactivity coefficients. Several concepts have been successfully established for them based on the neutronics calculations. Based on these concepts, detailed investigations on such as plutonium multiple recycling and control rod planning have been performed as well as improvement on core performances. Through these detailed core design investigation, the feasibility of those designs has been confirmed step by step.
Kureta, Masatoshi; Akimoto, Hajime; Yamamoto, Kazuhiko*; Okada, Hiroyuki*
Proceedings of International Congress on Advanced Nuclear Power Plants (ICAPP) (CD-ROM), 7 Pages, 2002/00
no abstracts in English
Iwamura, Takamichi; Okubo, Tsutomu; Yonomoto, Taisuke; Takeda, Renzo*; Moriya, Kumiaki*; Kanno, Minoru*
Proceedings of International Congress on Advanced Nuclear Power Plants (ICAPP) (CD-ROM), 8 Pages, 2002/00
Research and developments of reduced-moderation water reactor (RMWR) have been performed. The RMWR can attain the favorable characteristics such as high burn-up, long operation cycle, multiple recycling of plutonium and effective utilization of uranium resources, based on the matured LWR technologies. MOX fuel assemblies in the tight-lattice fuel rod arrangement are used to reduce the moderation of neutron, and hence, to increase the conversion ratio. The conceptual design has been accomplished for the small 330MWe RMWR core with the discharge burn-up of 60GWd/t and the operation cycle of 24 months, under the natural circulation cooling of the core. A breeding ratio of 1.01 and the negative void reactivity coefficient are simultaneously realized in the design. In the plant system design, the passive safety features are intended to be utilized mainly to improve the economy. At present, a hybrid one under the combination of the passive and the active components, and a fully passive one are proposed. The former has been evaluated to reduce the cost for the reactor components.
Hibi, Koki*; Shimada, Shoichiro*; Okubo, Tsutomu; Iwamura, Takamichi; Wada, Shigeyuki*
Nuclear Engineering and Design, 210(1-3), p.9 - 19, 2001/12
Times Cited Count:25 Percentile:84.32(Nuclear Science & Technology)no abstracts in English
Okubo, Tsutomu; Takeda, Renzo*; Iwamura, Takamichi
JAERI-Research 2001-021, 84 Pages, 2001/03
no abstracts in English
Iwamura, Takamichi; Ochiai, Masaaki
Proceedings of 1st Asian Specialist Meeting of Future Small-Sized LWR Development, p.7_1 - 7_9, 2001/00
JAERI has developed two types of small and medium size Light Water Reactors to meet the goals of innovative nuclear reactors such as sustainability and diversification of energy utilization. One is the Reduced-Moderation light Water Reactor (RMWR) with passive safety features. The reactor core consists of MOX fuel assemblies with tight lattice arrangement to increase the conversion ratio by reducing the moderation of neutron energy. The core design of 330MWe output with the operational cycle of 26 months was accomplished. A breeding ratio of 1.01, negative void coefficient and natural circulation cooling of the core were realized under the discharged burn-up of 60GWd/t. The other is the Passive Safe small Reactor for Distributed energy systems (PSRD) to diversify the nuclear energy utilization. An innovative advanced marine reactor (MRX) is used to supply the small grid electricity or electricity and heat co-supply by installing it on a barge. A small integral LWR for underground deployment is also studied for exclusive use of heat supply to household or office.
Okubo, Tsutomu; Iwamura, Takamichi; Akimoto, Hajime; Araya, Fumimasa; Onuki, Akira; Yamamoto, Kazuhiko*
Dai-7-Kai Doryoku Enerugi Gijutsu Shimpojiumu Koen Rombunshu (00-11), p.250 - 253, 2000/11
no abstracts in English
Research Group for Advanced Reactor System; Research Group for Reactor Physics; Research Group for Thermal and Fluid Engineering
JAERI-Research 2000-035, 316 Pages, 2000/09
no abstracts in English
Shimada, Shoichiro*; Akie, Hiroshi; Suzaki, Takenori; Okubo, Tsutomu; Usui, Shuji*; Shirakawa, Toshihisa*; Iwamura, Takamichi; Kugo, Teruhiko; Ishikawa, Nobuyuki
JAERI-Research 2000-026, 74 Pages, 2000/06
no abstracts in English
Ishikawa, Nobuyuki; Nakatsuka, Toru; Iwamura, Takamichi
JAERI-Conf 2000-010, 267 Pages, 2000/06
no abstracts in English
Tatematsu, Kenji; Sato, Osamu; Tanaka, Yoji*
JAERI-Research 2000-025, 74 Pages, 2000/05
no abstracts in English
Yoshida, Hiroyuki; Onuki, Akira; Akimoto, Hajime
JAERI-Tech 2000-024, p.31 - 0, 2000/03
no abstracts in English
Iwamura, Takamichi
Genshiryoku eye, 46(1), p.19 - 23, 2000/00
no abstracts in English
Okubo, Tsutomu; Araya, Fumimasa
Proceedings of International Workshop on Current Status and Future Directions in Boiling Heat Transfer and Two-Phase Flow, p.177 - 181, 2000/00
no abstracts in English