Kirihara, Yoichi; Nakashima, Hiroshi; Sanami, Toshiya*; Namito, Yoshihito*; Itoga, Toshiro*; Miyamoto, Shuji*; Takemoto, Akinori*; Yamaguchi, Masashi*; Asano, Yoshihiro*
Journal of Nuclear Science and Technology, 57(4), p.444 - 456, 2020/04
no abstracts in English
Deguchi, Akira*; Umeki, Hiroyuki*; Ueda, Hiroyoshi*; Miyamoto, Yoichi; Shibata, Masahiro; Naito, Morimasa; Tanaka, Toshihiko*
LBNL-1006984 (Internet), p.12_1 - 12_22, 2016/12
The H12 report demonstrated the feasibility of safe and technically reliable geological disposal in 1999. The Government of Japan re-evaluated the geological disposal program in terms of technical feasibility based on state-of-the-art geosciences and implementation process, because more than 10 years have passed from H12 and the Great Earthquake and nuclear accident have increased public concern regarding nuclear issues and natural hazards to cause accidents at nuclear facilities. Following the re-evaluation, the Government concluded further to promote geological disposal program, and thus the Basic Policy for Final Disposal was revised in 2015 including a new approach to siting process with identification of "Scientifically Preferable Areas". NUMO and relevant research organizations such as JAEA have been carrying out R and D activities to increase technical reliability for geological disposal. NUMO has started to develop a generic safety case.
Koide, Kaoru; Osawa, Hideaki; Ito, Hiroaki; Tanai, Kenji; Semba, Takeshi; Naito, Morimasa; Sugihara, Kozo; Miyamoto, Yoichi
Annual Waste Management Symposium (WM 2015), Vol.5, p.3631 - 3645, 2015/00
JAEA has promoted R&D on HLW geological disposal technology. JAEA launched the Mizunami and the Horonobe URL Projects to cover the diversity of geological environments in Japan. The Mizunami URL Project is a geoscientific research project in the crystalline rock environment. The Horonobe URL Project consists of geoscientific studies and R&D on geological disposal technology in the sedimentary rock environment. Both URL projects have been planned to proceed in three overlapping phases, Surface-based investigation Phase, Construction Phase and Operation Phase. Currently, the construction of research galleries in both of the Mizunami and the Horonobe URLs has been completed to 500 m and 350 m depths, respectively. JAEA will promote R&D activities in Phase III including study of the long-term evolution of the geological environment, and contribute to international cooperation, development of human resources and communication amongst stakeholders through both URL projects.
Dekomisshoningu Giho, (47), p.10 - 28, 2013/03
no abstracts in English
Sugihara, Shinji*; Tanaka, Masahiro*; Tamari, Toshiya*; Shimada, Jun*; Takahashi, Tomoyuki*; Momoshima, Noriyuki*; Fukutani, Satoshi*; Atarashi-Andoh, Mariko; Sakuma, Yoichi*; Yokoyama, Sumi*; et al.
Fusion Science and Technology, 60(4), p.1300 - 1303, 2011/11
The purpose of this study is to develop the technique to evaluate the environmental tritium behavior of the nuclear facility origin. Tritium concentrations of river water, precipitation and ground water around the NIFS site were determined by low background liquid scintillation measurement system combined with the electrolysis using solid polymer electrolyte. The electric conductivity and flow rate of the river and isotopic ratio of oxygen and hydrogen of water samples were also measured. The tritium concentrations in precipitation showed the seasonal variation and the range were 0.09-0.78 Bq/L. The tritium concentrations of river water and ground water were almost constant, 0.34 and 0.24 Bq/L respectively. The simple dynamic model for the site around the NIFS facilities was developed using measured data, and the behavior of tritium was simulated.
Ito, Hideaki; Maeda, Shigetaka; Naito, Hiroyuki; Akiyama, Yoichi; Miyamoto, Kazuyuki; Ashida, Takashi; Noguchi, Koichi; Ito, Chikara; Aoyama, Takafumi
JAEA-Technology 2010-049, 129 Pages, 2011/03
The in-vessel gamma dose rate was measured in the experimental fast reactor Joyo to evaluate the activation of reactor structural components and the radiation exposure of the fiber scope used for in-vessel visual inspection. The measurement system, which requires a wide sensitivity range and high durability in a high-temperature environment, was specifically developed for use in the sodium cooled fast reactor. Using this system, the in-vessel gamma dose rate with cooling times of 450 and 720 days after reactor shutdown was measured in Joyo, which has been operated for 71,000 hours over approximately 30 years. The gamma dose rate was calculated using QAD-CGGP2 code with the gamma source intensity obtained by the ORIGEN2 code. The neutron flux used as input to the ORIGEN2 was evaluated by the Joyo dosimetry method. The ratio between the calculated and experimental values ranged from 1.1 to 2.4, confirming the accuracy of gamma dose rate and component activation calculation.
Yui, Mikazu; Ishikawa, Hirohisa; Watanabe, Atsuo*; Yoshino, Kyoji*; Umeki, Hiroyuki; Hioki, Kazumasa; Naito, Morimasa; Seo, Toshihiro; Makino, Hitoshi; Oda, Chie; et al.
JAEA-Research 2010-015, 106 Pages, 2010/05
This report summarizes the activity of Phase I of Waste Management Working Group of the United States - Japan Joint Nuclear Energy Action Plan started in 2007. The working group focused on consolidation of the existing technical basis between the U.S. and Japan and the joint development of a plan for future collaborative activities. Firstly, the political/regulatory frameworks related to nuclear fuel cycles in both countries were reviewed. The various advanced fuel cycle scenarios in both countries were surveyed and summarized. Secondly, the waste management/disposal system optimization was discussed. Repository system concepts for the various classifications of nuclear waste were reviewed and summarized, then disposal system optimization processes and techniques were reviewed, and factors to consider in future repository design optimization activities were also discussed. Finally the potential collaboration areas and activities related to the optimization problem were extracted.
Usuda, Shigekazu; Shinohara, Nobuo; Sakurai, Satoshi; Magara, Masaaki; Miyamoto, Yutaka; Esaka, Fumitaka; Yasuda, Kenichiro; Kokubu, Yoko; Hirayama, Fumio; Lee, C. G.; et al.
KEK Proceedings 2007-16, p.13 - 22, 2008/02
For the purpose of controlling and monitoring radiations and radioactive materials emitted from nuclear facilities to the environment and also evaluating their effects, various R&D on environmental radioactivity has been carried out at Japan Atomic Energy Agency (JAEA). Especially, for the abolition of nuclear weapons and for peaceful uses nuclear energy, ultra-trace analysis of environmental samples for safeguards and ultra-high sensitive monitoring of radionuclides for the CTBT verification, which have been scheduled in the middle of 1990s, have been promotted under the auspices of the Japanese Government at JAERI, the former of JAEA. In this presentation, the outline of R&D on environmental radioactivity for nuclear non-proliferation is introduced. In addition, applications of the developed techniques and future perspectives will be discussed.
Umeki, Hiroyuki; Naito, Morimasa; Makino, Hitoshi; Osawa, Hideaki; Nakano, Katsushi; Miyamoto, Yoichi; McKinley, I. G.*
Proceedings of 15th International Conference on Nuclear Engineering (ICONE-15) (CD-ROM), 8 Pages, 2007/04
no abstracts in English
Miyamoto, Yoichi; Umeki, Hiroyuki; Osawa, Hideaki; Naito, Morimasa; Nakano, Katsushi; Makino, Hitoshi; Shimizu, Kazuhiko; Seo, Toshihiro
Nuclear Engineering and Technology, 38(6), p.505 - 534, 2006/08
Ensuring sufficient supplies of clean, economic and acceptable energy is a critical global challenge for the 21st century. There seems little alternative to a greatly expanded role for nuclear power, but implementation of this option will depend on ensuring that all resulting wastes can be disposed of safely. Although there is a consensus on the fundamental feasibility of such disposal by experts in the field, concepts have to be developed to make them more practical to implement and, in particular, more acceptable to key stakeholders. By considering global trends and using illustrative examples from Japan, key areas for future R&D are identified and potential areas where the synergies of international collaboration would be beneficial are highlighted.
Umeki, Hiroyuki; Osawa, Hideaki; Sonobe, Hitoshi; Miyamoto, Yoichi
Dai-5-Kai Anzen Kenkyu Seika Hokokukai Koenrokushu; Hoshasei Haikibutsu No Chiso Shobun Ni Tsuite, p.5 - 29, 2006/03
no abstracts in English
Hirota, Naoki*; Hokida, Takanori; Inoue, Yoji; Kumata, Masahiro; Kurosawa, Yoshiaki; Miyamoto, Yutaka; Nakahara, Yoshinori; Oda, Tetsuzo; Shinohara, Nobuo; Uchikoshi, Takako*; et al.
JAERI-Review 2003-021, 68 Pages, 2003/08
This report describes research activities of the R & D Group for Non-Proliferation Technology related to the Comprehensive Nuclear-Test-Ban Treaty (CTBT) verification regime. The main subjects of this report are (1) an overview of the CTBT verification regime, (2) preparation of the National Data Center for radionuclide data, (3) construction and operation of the radionuclide monitoring stations at Takasaki and Okinawa and the certified rarionuclide laboratory at Tokai in Japan. We have participated in an intercomparison test internationally organized for the certified laboratories and the test results are given here. Scientific application of the CTBT-related technologies to environmental researches is also depicted.
Hanzawa, Yukiko; Magara, Masaaki; Watanabe, Kazuo; Esaka, Fumitaka; Miyamoto, Yutaka; Yasuda, Kenichiro; Gunji, Katsubumi*; Yamamoto, Yoichi; Takahashi, Tsukasa; Sakurai, Satoshi; et al.
JAERI-Tech 2002-103, 141 Pages, 2003/02
The JAERI has established a facility with a cleanroom: the Clean Laboratory for Environmental Analysis and Research (CLEAR). This report is an overview of the design, construction and performance evaluation of the CLEAR in the initial stage of the laboratory operation in June 2001. The CLEAR is a facility to be used for ultra trace analyses of nuclear materials in environmental samples for the safeguards, for the CTBT verification and for researches on environmental sciences. The CLEAR meets double requirements of a cleanroom and for handling of nuclear materials. Much attention was paid to the construction materials of the cleanroom for trace analysis of metal elements using corrosive acids. The air conditioning and purification system, experimental equipment, utilities and safety systems are also demonstrated. The potential contamination from the completed cleanroom atmosphere during the analytical procedure was evaluated. It can be concluded that the CLEAR has provided a suitable condition for reliable analysis of ultra trace amounts of nuclear materials in environmental samples.
Ogo, Takeo; Miyamoto, Yoichi; Kawagoshi, Hiroshi
Saikuru Kiko Giho, (20), p.23 - 30, 2003/00
Kumata, Masahiro; Oda, Tetsuzo; Miyamoto, Yutaka; Uchikoshi, Takako*; Nakahara, Yoshinori; Yamamoto, Yoichi; Hokida, Takanori; Hirota, Naoki*; Inoue, Yoji; Shinohara, Nobuo
Dai-23-Kai Kaku Busshitsu Kanri Gakkai Nihon Shibu Nenji Taikai Rombunshu, p.39 - 44, 2002/12
The International Monitoring System (IMS) will be established across the world to verify compliance with the Comprehensive Test Ban Treaty (CTBT). The IMS will be capable of detecting and identifying nuclear explosions of detonated within the atmosphere, underwater and underground. 321 monitoring stations will be set around the world as a monitoring network of the IMS. The four technologies of seismology, hydroacoustic, infrasound, and radionuclide will be used for monitoring purposes. In order to build the radionuclide monitoring network, 80 radionuclide stations were chosen. Particles in the atmosphere are collected on a filter at each station to measure radioactivity by a HP-Ge detector. Further, 40 out of these 80 stations will be equipped with an automatic radioactive noble gas sampler/analyzer. The JAERI is establishing infrastructure to host radionuclide air monitoring equipment for two raionuclide stations in Japan. This paper presents the current status of the establishment and promising performance of the stations in Japan.
Kawamura, Kazuhiro; Miyamoto, Yoichi; Ouchi, Jin
Glass Technology, 39(4), p.142 - 148, 2002/00
Kawamura, Kazuhiro; Miyamoto, Yoichi
High Temperature Materials and Processes, 16(3), p.169 - 172, 2002/00
Hokida, Takanori; Oda, Tetsuzo; Yamamoto, Yoichi; Miyamoto, Yutaka; Adachi, Takeo
Dai-21-Kai Kaku Busshitsu kanri Gakkai (INMM) Nihon Shibu Nenji Taikai Rombunshu, p.17 - 24, 2000/00
no abstracts in English
Iwase, Masanori*; Kawamura, Kazuhiro; Miyamoto, Yoichi; Ouchi, Jin
Glass Technology, 39(4), p.142 - 146, 1998/08
Miyamoto, Yoichi; Kawamura, Kazuhiro; Yoneya, Masayuki; Kobayashi, Aoi
PNC TN8410 98-119, 79 Pages, 1998/07