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Ojima, Hisao
JAEA-Review 2010-064, 27 Pages, 2011/01
This report summarizes the feature of nuclear fuel cycle facilities, such as the process adopted or nominal capacity, in France, according to disclosed materials, basically. It was confirmed that the capacity of French facility is coherent well each other. Recycling aspect of chemical reagent used in the cycle, especially the fluorine, has been investigated, as well as nuclear materials. Based on the known plans about renewal of current facilities, a preliminary study on a possibility of step-up in production has been conducted. As facilities locate all over the land in France, the transportation of nuclear materials is an essential work. Focusing on the uranium and plutonium recovered in the reprocessing plant, the status and supposed subjects of their transportation are mentioned.
Ojima, Hisao
JAEA-Review 2008-020, 28 Pages, 2008/07
The mined uranium ore is refined and becomes a "yellow cake" in which the uranium content is about 60%. Then the yellow cake is converted into UF that is the raw material of uranium enrichment. The content of U is enriched usually by means of the centrifuge separation. The enriched uranium is converted into UO and is used for pellet fabrication. Finally, the uranium is used in the LWR plant as nuclear fuel. The uranium and plutonium are recovered from the spent fuel in the reprocessing plan and they are used as nuclear fuel again. As for the method of the reprocessing, the PUREX process using TBP as extractant is a main stream because of its stability and safety in operation. The preprocessing process consists of a head-end process including a shearing process, a dissolution process, and a clarification process, and a chemical process including a solvent extraction process, a concentration process, a denitration process and mixed conversion process. The nitric acid and the solvent are recycled in the plant and high level liquid waste is vitrified into glass form, finally. In Japan, through the experience of the Tokai Reprocessing Plant, the first commercial reprocessing plant, Rokkasho Reprocessing Plant, will start its operation in 2008. The spent fuel from FBR can be reprocessed by the PUREX method taking into account of its characteristics such as high plutonium content rate, high burn-up, and the structure of fuel assembly. Currently, the adoption of a new technology is examined aiming for further economy improvement and the achievement of the reduction of the waste load. The safeguards is the activity to prevent the diversion of nuclear material.
Ojima, Hisao; Dojiri, Shigeru; Tanaka, Kazuhiko; Takeda, Seiichiro; Nomura, Shigeo
Proceedings of International Conference on Advanced Nuclear Fuel Cycles and Systems (Global 2007) (CD-ROM), p.273 - 282, 2007/09
The Nuclear Fuel Cycle Engineering Laboratories of Japan Atomic Energy Agency (JAEA) was established to take over activities of the Tokai Works of Japan Nuclear Cycle Development Institute (JNC). From 1959, several kinds of technologies (such as uranium refining, centrifuge for uranium enrichment, LWR spent fuel reprocessing and MOX fuel fabrication) have been accomplished. And also, R&Ds on the treatment and disposal of high level waste and the FBR fuel reprocessing have been carried out. Through such activities, control of environmental release of radioactive material and radiation exposure and management of nuclear materials have been done appropriately. The Laboratories will contribute to establish the closed cycle with R&Ds of the reprocessing technology during the transition period from LWR era to FBR era, improved MOX fuel fabrication technology, advanced FBR fuel reprocessing technology and high level waste disposal technology.
Ojima, Hisao; Hayashi, Naoto; Nagai, Toshihisa; Fujita, Yuji; Kawata, Tomio
Proceedings of International Conference on Nuclear Energy System for Future Generation and Global Sustainability (GLOBAL 2005) (CD-ROM), 5 Pages, 2005/10
This paper mentions a preliminary evaluation on the typical LWR-to-FBR transition scenarios. Deployment rate of FBRs is strongly connected with replacement rate of LWRs, however, the transition should be seen as a matter of the optimization of fuel cycle systems. Based on the Pu balance evaluation, it seems definitely necessary to save an adequate amount of LWR spent fuels before beginning the deployment of FBRs. The mission of the second LWR fuel reprocessing plant in Japan will most provably be to feed Pu needed for starting up new FBRs. Along with the Pu utilization, especially as LWR-MOX fuel, the accumulation of minor actinides(MAs) in the high-level radioactive waste will become dominant and finally result in larger number of vitrified HLW because of heat generation from MAs. MA recovery cycle combined with the FBR will gives successful solution on this matter. Requirements on the next generation reprocessing plant, which corresponds to the transition scenario, are studied and innovative concept named
Ojima, Hisao; Nomura, Kazunori; Morimoto, Kyoichi; Harada, Hideo
Proceedings of Technology Forum on Protected Plutonium Utilization for Peace and Sustainable Prosperity, 54 Pages, 2004/00
The application of the fluoride volatility process in the reprocessing of fuel from the fast breeder reactor is regarded as one of the economical methods. Plutonium hexafluoride (PuF6), however, reacting with fluorine (F2) and plutonium dioxide (PuO) as the raw material, is in an unstable condition and tends to remain as a solid compound in the process after decomposing into plutonium tetrafluoride (PuF4). Suitable conditions should be established for the practical use of this process. One of them is to enhance the stability of PuF. The behaviour of plutonium fluorination and relevant chemical reactions were investigated by referring to sundry literature and by thermodynamic calculation. It was then compared with recent data from laboratory scale experiments for this paper. Results from the theoretical analysis agreed with experimental observation that PuF could be formed stably under a high temperature condition (approx.1000 K) with over supply of figher concentration of F2.
Nomura, Shigeo; Yamato, Aiji; Ojima, Hisao
CD-ROM, 5P., 5 Pages, 2003/00
In Japan, the Feasibility study for commercialization of FBR and its fuel cycle system (FS) has been conducted under the collaboration of JNC and the electric utilities since 1999. Through the FS, candidate technology will be selected by 2015.
Ojima, Hisao; Torata, Shinichiro; Nomura, Kazunori; Kato, Hiroshi
Proceedings of 2nd International Workshop on Nuclear Fuel Cycle; Nuclear Fuel Cycle from the Viewpoint of Disposal Site Utilization, p.34 - 35, 2003/00
None
; Nomura, Shigeo; Ojima, Hisao; Funasaka, Hideyuki
Proceedings of International Conference on Advanced Nuclear Energy and Fuel Cycle Systems (GLOBAL 2003) (CD-ROM), p.1290 - 1298, 2003/00
None
Nomura, Shigeo; Ojima, Hisao; Funasaka, Hideyuki
Proceedings of International Conference on Advanced Nuclear Energy and Fuel Cycle Systems (GLOBAL 2003) (CD-ROM), 1290 Pages, 2003/00
Three candidate systems of spent fuel reprocessing integrated with fuel fabrication process,i.e.advanced aqueous,oxide electrowinning and metal electrorefining are studied as the Feasibility Study(FS)Phase-2 for advanced fast reactor fuel cycle.
*; Fujii, Toshiyuki*; Moriyama, Hirotake*; ; ; Myochin, Munetaka; Ojima, Hisao
JNC TY8400 2002-013, 57 Pages, 2002/03
no abstracts in English
Suzuki, Masahiro; ; Ojima, Hisao
CIMTEC2002(2rd International Conference:Computational Modelling and Simulation of Materials), 0 Pages, 2002/00
None
Nagai, Toshihisa; Ojima, Hisao; ;
Proceedings of 10th International Conference on Nuclear Engineering (ICONE-10), 0 Pages, 2002/00
None
Ojima, Hisao; Nagaoki, Yoshihiro
INMM/ESARDA Workshop, 0 Pages, 2000/00
None
; Sugiyama, Kenji; ; ; ; Ojima, Hisao;
PNC TN1430 97-005, 229 Pages, 1997/11
no abstracts in English
Nomura, Shigeo; Kawata, Tomio; ; Ojima, Hisao
Proceedings of International Conference on Future Nuclear Systems (GLOBAL'97), 0 Pages, 1997/10
None
Ojima, Hisao; ; ;
Proceedings of International Conference on Future Nuclear Systems (GLOBAL'97), 0 Pages, 1997/06
From the aspects of economy, waste problems and proliferation resistivity, PNC proposed a drastically improved concept for FBR fuel recycle as advanced fuel recycle system. The reprocessing process in this system, single cycle U/Pu co-extraction flowsheet, is based on the well experienced purex process. The products from it in lower decontamination factor (df) are handled with remote fuel fabrication techniques in cells. The fabrication system consists of gelation and vibro-packing is one of the promising method for remote fabrication process in cells. These remote process are installed in an integrated fuel recycle plant of reprocessing and fabrication, and drastically reduce plant size. this concept contributes to economy and reduction of generation of wastes, and strengthen the fuel rec