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Tokunaga, Sho; Horiguchi, Hironori; Nakamura, Takemi
JAEA-Technology 2023-001, 37 Pages, 2023/05
The cold neutron source (CNS) of the research reactor JRR-3 converts thermal neutrons generated in the reactor into low-energy cold neutrons by moderating them with liquid hydrogen stored in the moderator cell. Cold neutrons generated by the CNS are transported to experimental instruments using neutron conduits, and are used for many studies of physical properties, mainly in life science, polymer science, environmental science, etc. Improvement of cold neutron intensity is essential to maintain competitiveness with the world's research reactors in neutron science, and we are developing a new CNS that incorporates new knowledge. The current moderator cell for the CNS of JRR-3 is a stainless-steel container which is a canteen bottle type, and the cold neutron intensity can be improved by changing the material and shape. Therefore, the basic specifications of the new moderator cell were changed to aluminum alloy which has a smaller neutron absorption cross section, and the shape was optimized using a Monte Carlo code MCNP. Since these changes in specifications will result in changes in heat generation and heat transfer conditions, the CNS of JRR-3 was re-evaluated in terms of self-regulating characteristic, heat transport limits, heat resistance and pressure resistance, etc., to confirm its feasibility in thermal-hydraulic design. This report summarizes the results of the thermal-hydraulic design evaluation of the new moderator cell.
Tokunaga, Sho; Iguchi, Shintaro; Kawamura, Sho; Hirane, Nobuhiko
JAEA-Technology 2022-004, 74 Pages, 2023/02
In JRR-3, in response to the new regulatory standard for research reactors that is enforced December 2013, we submitted the application document of reactor installation license for the JRR-3 on September 2014, and acquired the permission on November 2018. Thereafter, we carried out impact assessment for internal overflow based on the design principles as described in the application document of reactor installation license for the JRR-3. There are two legal requirements for internal overflow. The first is to ensure that the necessary safety functions are not lost due to internal overflow that occur in the facility. The second is to prevent leakage of liquid containing radioactive materials outside the radiation controlled area in the event of an internal overflow. For these requirements, assuming each overflow source, it was confirmed that the necessary safety functions would not be lost and that liquid containing radioactive materials would not leak outside the controlled area. Regarding these assessments, design and construction plans were submitted in installments, and the approvals were obtained sequentially. This report shows the result that is impact assessment for internal overflow in JRR-3.
Okutani, Akira*; Onishi, Hiroaki; Kimura, Shojiro*; Takeuchi, Tetsuya*; Kida, Takanori*; Mori, Michiyasu; Miyake, Atsushi*; Tokunaga, Masashi*; Kindo, Koichi*; Hagiwara, Masayuki*
Journal of the Physical Society of Japan, 90(4), p.044704_1 - 044704_9, 2021/04
Times Cited Count:1 Percentile:19.03(Physics, Multidisciplinary)Ishizawa, Akihiro*; Idomura, Yasuhiro; Imadera, Kenji*; Kasuya, Naohiro*; Kanno, Ryutaro*; Satake, Shinsuke*; Tatsuno, Tomoya*; Nakata, Motoki*; Nunami, Masanori*; Maeyama, Shinya*; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 92(3), p.157 - 210, 2016/03
The high-performance computer system Helios which is located at The Computational Simulation Centre (CSC) in The International Fusion Energy Research Centre (IFERC) started its operation in January 2012 under the Broader Approach (BA) agreement between Japan and the EU. The Helios system has been used for magnetised fusion related simulation studies in the EU and Japan and has kept high average usage rate. As a result, the Helios system has contributed to many research products in a wide range of research areas from core plasma physics to reactor material and reactor engineering. This project review gives a short catalogue of domestic simulation research projects. First, we outline the IFERC-CSC project. After that, shown are objectives of the research projects, numerical schemes used in simulation codes, obtained results and necessary computations in future.
Nakamura, Kazuo*; Jiang, Y.*; Liu, X.*; Mitarai, Osamu*; Kurihara, Kenichi; Kawamata, Yoichi; Sueoka, Michiharu; Hasegawa, Makoto*; Tokunaga, Kazutoshi*; Zushi, Hideki*; et al.
Fusion Engineering and Design, 86(6-8), p.1080 - 1084, 2011/10
Times Cited Count:4 Percentile:33.04(Nuclear Science & Technology)Namba, Hideki; Hashimoto, Shoji; Tokunaga, Okihiro; *
Radiation Physics and Chemistry, 53(6), p.673 - 681, 1998/00
Times Cited Count:11 Percentile:66.66(Chemistry, Physical)no abstracts in English
Hashimoto, Shoji; Tokunaga, Okihiro
OHM (Sougou Denki Zasshi), 82(9), p.55 - 59, 1995/09
no abstracts in English
*; *; Tokunaga, Okihiro; Hashimoto, Shoji; Namba, Hideki; *; *
Denki Hyoron, 0(8), p.70 - 73, 1995/08
no abstracts in English
Namba, Hideki; Tokunaga, Okihiro; Hashimoto, Shoji; *; *; *; *; *
JAERI-Tech 95-013, 6 Pages, 1995/03
no abstracts in English
Hashimoto, Shoji; Namba, Hideki; Tokunaga, Okihiro; *; *; *; *; *
1995 SO Control Symp., Book 3, 0, 10 Pages, 1995/03
no abstracts in English
*; *; *; *; Namba, Hideki; Tokunaga, Okihiro; Hashimoto, Shoji; *; *
Ebara Jiho, (166), p.56 - 64, 1995/00
no abstracts in English
Namba, Hideki; Tokunaga, Okihiro; Hashimoto, Shoji; *; *; *; *; *
Radiation Physics and Chemistry, 46(4-6), p.1103 - 1106, 1995/00
Times Cited Count:35 Percentile:93.88(Chemistry, Physical)no abstracts in English
Hirota, Koichi; Tokunaga, Okihiro; Miyata, Teijiro; Sato, Shoichi; *; *; *; *; *; *; et al.
Radiation Physics and Chemistry, 46(4-6), p.1089 - 1092, 1995/00
Times Cited Count:10 Percentile:69.34(Chemistry, Physical)no abstracts in English
*; Tokunaga, Okihiro; Arai, Hidehiko; Hashimoto, Shoji
Kankyo Eisei Kogaku Kenkyu, 7(3), p.177 - 182, 1993/07
no abstracts in English
Tokunaga, Okihiro; Aoki, Yasushi; Sato, Shoichi; *; *; *; *
Applications of Isotopes and Radiation in Conservation of the Environment, p.105 - 114, 1992/00
no abstracts in English
*; *; *; Tokunaga, Okihiro; Aoki, Yasushi; Sato, Shoichi; *; *; *
Proceedings of International Conference on Evolution in Beam Applications, p.482 - 485, 1992/00
no abstracts in English
Namba, Hideki; Tokunaga, Okihiro; Sato, Shoichi; *; *; *; *; *
3rd Int. Symp. on Advanced Nuclear Energy Research; Global Environment and Nuclear Energy, 5 Pages, 1991/00
no abstracts in English
Tokunaga, Okihiro; Arai, Hidehiko; Hashimoto, Shoji
Proceedings of International Conference on Evolution in Beam Applications, p.417 - 422, 1991/00
no abstracts in English
Sato, Shoichi; Tokunaga, Okihiro; Arai, Hidehiko; Hashimoto, Shoji
Transactions of the American Nuclear Society, SUPPL.61, p.425 - 430, 1990/00
no abstracts in English
Nakamura, Kazuo*; Matsufuji, Shinji*; Tomoda, Seiji*; Wang, F.*; Mitarai, Osamu*; Kurihara, Kenichi; Kawamata, Yoichi; Sueoka, Michiharu; Hasegawa, Makoto*; Tokunaga, Kazutoshi*; et al.
no journal, ,
no abstracts in English