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Suzuki, Seiya; Arai, Yoichi; Okamura, Nobuo; Watanabe, Masayuki
Journal of Nuclear Science and Technology, 60(7), p.839 - 848, 2023/07
Times Cited Count:0 Percentile:0.01(Nuclear Science & Technology)The fuel debris, consisting of nuclear fuel materials and reactor structural materials, generated in the accident of Fukushima Daiichi Nuclear Power Plant can become deteriorated like rocks under the changes of environmental temperature. Although the fuel debris have been cooled by water for 10 years, they are affected by seasonal and/or day-and-night temperature changes. Therefore, in evaluating the aging behavior of the fuel debris, it is essential to consider the changes in environmental temperature. Assuming that the fuel debris are deteriorated, radioactive substances that have recently undergone micronization could be eluted into the cooling water, and such condition may affect defueling methods. We focused on the effect of repeated changes in environmental temperature on the occurrence of cracks, and an accelerated test using simulated fuel debris was carried out. The length of the crack increases with increasing number of heat cycle; therefore, the fuel debris become brittle by stress caused by thermal expansion and contraction. In conclusion, it was confirmed that the mechanical deterioration of the fuel debris is similar to that of rocks or minerals, and it became possible to predict changes in the length of the crack in the simulated fuel debris and environmental model.
Watanabe, Yukinobu*; Shigyo, Nobuhiro*; Kin, Tadahiro*; Iwamoto, Osamu
JAEA-Conf 2020-001, 236 Pages, 2020/12
The 2019 Symposium on Nuclear Data was held at Chikushi Campus Cooperation Building (C-Cube), Kyushu University, on November 28 to 30, 2019. The symposium was organized by the Nuclear Data Division of the Atomic Energy Society of Japan (AESJ) in cooperation with Sigma Investigative Advisory Committee of AESJ, Nuclear Science and Engineering Center of Japan Atomic Energy Agency, Kyushu Branch of AESJ, and Center for Accelerator and Beam Applied Science of Kyushu University. In the symposium, there were one tutorial, "From the resonance theory to statistical model", and five sessions, "Study on Nuclear Data and related topics", "Reactor physics", "International Cooperation", "Nuclear Physics", and "High Energy Nuclear Data and their Application". In addition, recent research progress on experiments, nuclear theory, evaluation, benchmark and applications was presented in the poster session. Among 85 participants, all presentations and following discussions were very active and fruitful. This report consists of total 42 papers including 13 oral and 29 poster presentations.
Hirota, Noriaki; Shibata, Hiroshi; Takeuchi, Tomoaki; Otsuka, Noriaki; Tsuchiya, Kunihiko
Journal of Nuclear Science and Technology, 57(12), p.1276 - 1286, 2020/12
Times Cited Count:0 Percentile:0.01(Nuclear Science & Technology)The influence of materials of mineral-insulated (MI) cables on their electrical characteristics upon exposure to high-temperature conditions was examined via a transmission test, in the objective of achieving the stability of the potential distribution along the cable length. Occurrence of a voltage drop along the cable was confirmed for aluminum oxide (AlO) and magnesium oxide (MgO), as insulating materials of the MI cable. A finite-element method (FEM)-based analysis was performed to evaluate the leakage in the potentials, which was found at the terminal end. Voltage drop yields by the transmission test and the analysis were in good agreement for the MI cable of AlO and MgO materials, which suggests the reproducibility of the magnitude relationship of the experimental results via the FEM analysis. To suppress the voltage drop, the same FEM analysis was conducted, the diameter of the core wires () and the distance between them () were varied. Considering the variation of , the potential distribution in the MI cable produced a minimum voltage drop corresponding to a ratio of 0.35, obtained by dividing with that of the insulating material (). In case of varying , a minimum voltage drop was l/ of 0.5.
Fukushima, Masahiro; Tojo, Masayuki*
Journal of Nuclear Science and Technology, 56(12), p.1061 - 1062, 2019/12
Times Cited Count:0 Percentile:0.32(Nuclear Science & Technology)Reactor Physics that treat the essentials of how fission nuclear reactors work fundamentally has important roles on safe operations and design studies of various types of nuclear reactors. From the latest activities in the field of reactor physics, this report summarizes some outstanding researches and developments published in scientific journals including the Journal of Nuclear Science and Technology.
Chiba, Satoshi*; Ishizuka, Chikako*; Tsubakihara, Kosuke*; Iwamoto, Osamu
JAEA-Conf 2019-001, 203 Pages, 2019/11
The 2018 Symposium on Nuclear Data was held at Multi-Purpose Digital Hall and Collaboration Room of Tokyo Institute of Technology, on November 29 and 30, 2018. The symposium was organized by the Nuclear Data Division of the Atomic Energy Society of Japan (AESJ) in cooperation with Sigma Special Committee of AESJ, Nuclear Science and Engineering Center of Japan Atomic Energy Agency, and Laboratory for Advanced Nuclear Energy of Institute of Innovative Research, Tokyo Institute of Technology. In the symposium, there were one tutorial, "Development of nuclear data processing code FRENDY", one special lecture "What the future holds for Nuclear Energy" and seven oral sessions, "Nuclear Data and Future Perspectives", "Current Status and Future Perspectives of Reactor Physics", "Topics", "Nuclear Data Applications", "International Session", "Nuclear Data Measurements and New Technology for Nuclear Reactor Diagnosis", and "Data Needs from New Fields". In addition, recent research progress on experiments, evaluation, benchmark and application was presented in the poster session. Among 82 participants, all presentations and following discussions were very active and fruitful. This report consists of total 35 papers including 13 oral and 22 poster presentations.
Sanami, Toshiya*; Nishio, Katsuhisa; Hagiwara, Masayuki*; Iwase, Hiroshi*; Kunieda, Satoshi; Nakamura, Shoji
JAEA-Conf 2017-001, 222 Pages, 2018/01
The 2016 Symposium on Nuclear Data was held at Kobayashi Hall of High Energy Accelerator Research Organization, on November 17 and 18, 2016. The symposium was organized by the Nuclear Data Division of the Atomic Energy Society of Japan in cooperation with Radiation Science Center, High Energy Accelerator Research Organization, Nuclear Science and Engineering Center of Japan Atomic Energy Agency and North Kanto Branch of Atomic Energy Society of Japan. In the symposium, there were one tutorial, "Historical Evolution of Accelerators" and four oral sessions, "Overview of the ImPACT Program - Reduction and Resource Recycling of High Level Wastes through Nuclear Transmutation", "Facilities and experiments for nuclear data in Japan", "Nuclear data from measurement to application", and "Progress of neutron nuclear data measurement and research for its basics and application". In addition, recent research progress on experiments, evaluation, benchmark and application was presented in the poster session. Among 65 participants, all presentations and following discussions were very active and fruitful. This report consists of total 31 papers including 10 oral and 21 poster presentations.
Ohgama, Kazuya; Ikeda, Kazumi*; Ishikawa, Makoto; Kan, Taro*; Maruyama, Shuhei; Yokoyama, Kenji; Sugino, Kazuteru; Nagaya, Yasunobu; Oki, Shigeo
Proceedings of 2017 International Congress on Advances in Nuclear Power Plants (ICAPP 2017) (CD-ROM), 10 Pages, 2017/04
Yamane, Yuichi; Amano, Yuki; Tashiro, Shinsuke; Abe, Hitoshi; Uchiyama, Gunzo; Yoshida, Kazuo; Ishikawa, Jun
Journal of Nuclear Science and Technology, 53(6), p.783 - 789, 2016/06
Times Cited Count:6 Percentile:43.12(Nuclear Science & Technology)The release behavior of radioactive materials from high active liquid waste (HALW) has been experimentally investigated under boiling accident conditions. In the experiments using HALW obtained through laboratory scale reprocessing, release ratio was measured for the FP nuclides such as Ru, Tc, Cs, Sr, Nd, Y, Mo, Rh and actinides such as Cm, Am. As a result, the release ratio was 0.20 for Ru and 1 for the FP and Ac nuclides. Ru was released into the gas phase in the form of both mist and gas. For its released amount, weak dependency was found to the initial concentration in the test solution. The release ratio decreased with the initial concentration. For other FP nuclides and actinides as non-volatile, released into the gas phase in the form of mist, the released amount increased with the initial concentration. The release ratio of Ru and NOx concentration increased with temperature of the test solutions. They were released almost at the same temperature between 200 and 300C. Size distribution of the mist and other particle was measured.
Verzilov, Y. M.; Sato, Satoshi; Ochiai, Kentaro; Wada, Masayuki*; Klix, A.*; Nishitani, Takeo
Fusion Engineering and Design, 82(1), p.1 - 9, 2007/01
Times Cited Count:10 Percentile:54.79(Nuclear Science & Technology)no abstracts in English
Okumura, Keisuke; Kawasaki, Kenji*; Mori, Takamasa
JAERI-Research 2005-018, 64 Pages, 2005/08
In the KRITZ-2 critical experiments, criticality and pin power distributions were measured at room temperature and high temperature (about 245 degree C) for three different cores loading slightly enriched UO or MOX fuels. For nuclear data testing, benchmark analysis was carried out with a continuous-energy Monte Carlo code MVP and its four nuclear data libraries based on JENDL-3.2, JENDL-3.3, JEF-2.2 and ENDF/B-VI.8. As a result, fairly good agreements with the experimental data were obtained with any libraries for the pin power distributions. However, the JENDL-3.3 and ENDF/B-VI.8 give under-prediction of criticality and too negative isothermal temperature coefficients for slightly enriched UO cores, while the older nuclear data JENDL-3.2 and JEF-2.2 give rather good agreements with the experimental data. From the detailed study with an infinite unit cell model, it was found that the differences among the libraries are mainly due to the different fission cross section of U-235 in the energy rage below 1.0 eV.
Tahara, Yoshihisa*; Fukahori, Tokio
JAERI-Conf 2005-003, 254 Pages, 2005/03
The 2004 Symposium on Nuclear Data was held at Tokai Research Establishment, Japan Atomic Energy Research Institute (JAERI), on 11th and 12th of November 2004. Japanese Nuclear Data Committee and Nuclear Data Center, JAERI organized this symposium. In the oral sessions, presented were 19 papers on topics of nuclear data for LWR and nuclear fuel cycle, nuclear data for ADS development, experiences from use of JENDL-3.3 and requests to JENDL-4, recent cross section measurements, nuclear data for life and material sciences, and nuclear data needs and activities in the World. In the poster session, presented were 21 papers concerning experiments, evaluations, benchmark tests, applications and so on. Those presented papers are compiled in the proceedings.
Nishitani, Takeo; Ochiai, Kentaro; Maekawa, Fujio; Shibata, Keiichi; Wada, Masayuki*; Murata, Isao*
IAEA-CN-116/FT/P1-22 (CD-ROM), 8 Pages, 2004/11
no abstracts in English
Kurihara, Kazuo; Tanaka, Ichiro*; Niimura, Nobuo
Nihon Kessho Gakkai-Shi, 46(3), p.193 - 200, 2004/05
Neutron diffraction provides an experimental method of directly locating hydrogen atoms in proteins and nucleic acids, and the development of the neutron imaging plate (NIP) became a breakthrough event in neutron protein crystallography. A high-resolution neutron diffractometers dedicated to biological macromolecules (BIX-3, BIX-4) with the NIP have been constructed at Japan Atomic Energy Research Institute. The detailed structure of the diffractometer and the systematic procedure of the neutron diffraction experiment from the crystallization of a large single crystal to the data collection and the data processing, and the future prospect of the neutron diffractometry in proteins will be presented.
Osawa, Takaaki*; Fukahori, Tokio
JAERI-Conf 2004-005, 262 Pages, 2004/04
The 2003 Symposium on Nuclear Data was held at Tokai Research Establishment, Japan Atomic Energy Research Institute (JAERI), on 27th and 28th of November 2003. Japanese Nuclear Data Committee and Nuclear Data Center, JAERI organized this symposium. In the oral sessions, presented were 18 papers on topics of ADS development and nuclear data for transmutation, nuclear data needs for next generation reactors and future JENDL plan, frontier of nuclear physics studies and nuclear data measurements, advanced science study and nuclear data, nuclear data needs and activities in Asian region, future of nuclear data study and other subjects. In the poster session, presented were 26 papers concerning experiments, evaluations, benchmark tests and so on. Those presented papers are compiled in the proceedings.
Shiroya, Seiji*; Misawa, Tsuyoshi*; Unesaki, Hironobu*; Ichihara, Chihiro*; Kobayashi, Keiji*; Nakamura, Hiroshi*; Shin, Kazuo*; Imanishi, Nobutsugu*; Kanazawa, Satoshi*; Mori, Takamasa
JAERI-Tech 2004-025, 93 Pages, 2004/03
In view of the future plan of Research Reactor Institute, Kyoto University, the present study consisted of (1) the transmission experiments of high energy neutrons through materials, (2) experimental simulation of ADSR using the Kyoto University Critical Assembly(KUCA), and (3) conceptual neutronics design study on KUR type ADSR using the MCNP-X code. Through the present study, valuable knowledge on the basic nuclear characteristics of ADSR, which is indispensable to promote the study on ADSR, was obtained both theoretically and experimentally. For the realization of ADSR, it is considered to be necessary to accumulate results of research steadily. For this purpose, it is inevitable (1) to compile the more precise nuclear data for the wide energy range, (2) to establish experimental techniques for reactor physics study on ADSR including subcriticality measurement and absolute neutron flux measurement, and (3) to develop neutronics calculation tools which take into account the neutron generation process by the spallation reaction and the delayed neutron behavior.
Nakagawa, Tsuneo
JAERI-Data/Code 2003-016, 89 Pages, 2003/11
The data storage and retrieval system for neutron-induced reaction data NESTOR2 was developed. NESTOR2 was written in Fortran77, and can be used on workstations with UNIX and personal computers with Windows. Input data to NESTOR2 are those in EXFOR which are compiled and maintained under the international collaboration for nuclear data. By using the retrieval code, they can obtain lists of data index, numerical data and comment information and data files of numerical data. The present report explains the system and provides a user's manual of NESTOR2.
Osawa, Takaaki*; Fukahori, Tokio
JAERI-Conf 2003-006, 318 Pages, 2003/06
The 2002 Symposium on Nuclear Data was held at Tokai Research Establishment, Japan Atomic Energy Research Institute (JAERI), on 21st and 22nd of November 2002. Japanese Nuclear Data Committee and Nuclear Data Center, JAERI organized this symposium. In the oral sessions, presented were 18 papers on topics of release of JENDL-3.3, requests from users, status of FP nuclear data, international activities and other subjects. In the poster session, presented were 33 papers concerning experiments, evaluations, benchmark tests and on-line database on nuclear data. Those presented papers are compiled in the proceedings.
Sugimoto, Makoto; Koizumi, Norikiyo; Isono, Takaaki; Matsui, Kunihiro; Nunoya, Yoshihiko; Tsutsumi, Fumiaki*; Oshikiri, Masayuki*; Wakabayashi, Hiroshi*; Okuno, Kiyoshi; Tsuji, Hiroshi
JAERI-Tech 2002-080, 100 Pages, 2002/11
The cool down of CS model coil and NbAl insert was started on March 4, 2002. It took almost one month and immediately started coil charge since April 3, 2002. The charge test of NbAl insert and CS model coil was completed on May 2, 2002. All of the experiments including the warm up was also completed on May 30, 2002.In this campaign, total shot numbers were 102 and the size of the data file in the DAS (Data Acquisition System) was about 5.2 GB. This report is a database that consists of the log list and the log sheets of every shot.
Sugimoto, Makoto; Isono, Takaaki; Matsui, Kunihiro; Nunoya, Yoshihiko; Tsutsumi, Fumiaki*; Tamiya, Tadatoshi*; Oshikiri, Masayuki*; Wakabayashi, Hiroshi*; Okuno, Kiyoshi; Tsuji, Hiroshi
JAERI-Tech 2001-085, 104 Pages, 2001/12
no abstracts in English
Yamano, Naoki*; Fukahori, Tokio
JAERI-Conf 2001-006, 346 Pages, 2001/03
no abstracts in English