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Hatakeyama, Nozomi*; Miura, Ryuji*; Miyamoto, Naoto*; Miyamoto, Akira*; Ara, Kuniaki; Shimoyama, Kazuhito; Kato, Atsushi; Yamamoto, Tomohiko
Journal of Computer Chemistry, Japan, 21(2), p.61 - 62, 2022/00
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.
Hirata, Yosuke*; Nakahara, Katsuhiko*; Sano, Akira*; Sato, Mitsuyoshi*; Aoyama, Yoshio; Miyamoto, Yasuaki; Yamaguchi, Hiromi; Nambu, Kenichi*; Takahashi, Hiroyuki*; Oda, Akinori*
Journal of Power and Energy Systems (Internet), 2(2), p.561 - 572, 2008/00
Aoyama, Yoshio; Miyamoto, Yasuaki; Yamaguchi, Hiromi; Sano, Akira*; Naito, Susumu*; Sumida, Akio*; Izumi, Mikio*; Maekawa, Tatsuyuki*; Sato, Mitsuyoshi*; Nambu, Kenichi*; et al.
Proceedings of 15th International Conference on Nuclear Engineering (ICONE-15) (CD-ROM), 6 Pages, 2007/04
no abstracts in English
Hirata, Yosuke*; Nakahara, Katsuhiko*; Sano, Akira*; Sato, Mitsuyoshi*; Aoyama, Yoshio; Miyamoto, Yasuaki; Yamaguchi, Hiromi; Nambu, Kenichi*; Takahashi, Hiroyuki*; Oda, Akinori*
Proceedings of 15th International Conference on Nuclear Engineering (ICONE-15) (CD-ROM), 6 Pages, 2007/04
no abstracts in English
Naito, Susumu*; Hirata, Yosuke*; Izumi, Mikio*; Sano, Akira*; Miyamoto, Yasuaki; Aoyama, Yoshio; Yamaguchi, Hiromi
Journal of Nuclear Science and Technology, 44(2), p.121 - 128, 2007/02
Times Cited Count：1 Percentile：11.4(Nuclear Science & Technology)A reinforced ion current prediction model in the alpha radioactivity measurement using ionized air transportation was presented. Although our previous model explained a qualitative trend of the measured ion current values, their absolute values were considerably overestimated. In order to explain them quantitatively, the model was reinforced in consideration of columnar recombination. It was found that our new model explains the considerable ion loss in the initial stage of ion diffusion and narrows the gap between the predicted and measured ion current values. This model also indicated a prospective suppression of ion loss due to columnar recombination by spraying a high-speed air flow on the contaminated surface. This suppression was experimentally investigated and confirmed. In conclusion, the theoretical relationship between alpha radioactivity and ion current was clarified quantitatively in laminar flow and turbulent pipe flow.
Sakurai, Satoshi; Magara, Masaaki; Usuda, Shigekazu; Watanabe, Kazuo; Esaka, Fumitaka; Hirayama, Fumio; Lee, C. G.; Yasuda, Kenichiro; Inagawa, Jun; Suzuki, Daisuke; et al.
Kaku Busshitsu Kanri Gakkai (INMM) Nihon Shibu Dai-27-Kai Nenji Taikai Rombunshu (CD-ROM), 9 Pages, 2006/00
no abstracts in English
Naito, Susumu*; Sano, Akira*; Izumi, Mikio*; Noda, Etsuo*; Hayashi, Kazuo*; Sato, Mitsuyoshi*; Suto, Osamu; Miyamoto, Yasuaki; Kondo, Shinichi*; Iinuma, Koichi*; et al.
Nuclear Science Symposium Conference Record, 2005 IEEE, Vol.1, p.495 - 499, 2005/10
An alpha radioactivity monitor (alpha-clearance monitor) is being developed to measure alpha radioactivity of uranium contaminated waste with large and complex surfaces. It uses an alpha radioactivity measurement method by collecting the air ionized by alpha particles using an air stream and by measuring its ion current. One of the major problems of the alpha-clearance monitor is the background ion current mainly by radon in atmosphere (
700 fA), which is much larger than ion current of an alpha particle (several fA). It strongly influences on the detection limit of alpha radioactivity. In order to improve the detection limit, we developed a method to monitor the radon concentration inside the monitor without the additional radon detector. In addition, the influencing factors on the detection limit: ion mobility and ion recombination coefficient were measured and evaluated on various environmental conditions (temperature, humidity and aerosol density).
Sakurai, Satoshi; Magara, Masaaki; Usuda, Shigekazu; Watanabe, Kazuo; Esaka, Fumitaka; Hirayama, Fumio; Lee, C. G.; Yasuda, Kenichiro; Kono, Nobuaki; Inagawa, Jun; et al.
Proceedings of International Conference on Nuclear Energy System for Future Generation and Global Sustainability (GLOBAL 2005) (CD-ROM), 6 Pages, 2005/10
no abstracts in English
Magara, Masaaki; Usuda, Shigekazu; Sakurai, Satoshi; Watanabe, Kazuo; Esaka, Fumitaka; Hirayama, Fumio; Lee, C. G.; Yasuda, Kenichiro; Kono, Nobuaki; Inagawa, Jun; et al.
Dai-26-Kai Kaku Busshitsu Kanri Gakkai (INMM) Nihon Shibu Nenji Taikai Rombunshu, p.157 - 164, 2005/00
JAERI has conducted the analysis of domestic and the IAEA samples. JAERI is developing the analytical techniques to improve the analytical ability for the safeguards environmental samples. For bulk analysis, study is focused on the improvement of reliability of isotope ratio measurements by ICP-MS. New chemical separation techniques are under development and a desolvation module is introduced to reduce the polyatomic interferences. In particle analysis, the sample preparation procedure for SIMS method is modified to measure the 
U/
U and 
U/U ratios for individual particles. We are also developing fission track-TIMS method to measure uranium isotope ratios in particles of sub-micrometer size. A screening instrument of X-ray fluorescent analysis is equipped to measure elemental distribution on a swipe surface.
Magara, Masaaki; Usuda, Shigekazu; Sakurai, Satoshi; Watanabe, Kazuo; Esaka, Fumitaka; Hirayama, Fumio; Lee, C. G.; Yasuda, Kenichiro; Kono, Nobuaki; Inagawa, Jun; et al.
Proceedings of INMM 46th Annual Meeting (CD-ROM), 8 Pages, 2005/00
JAERI has been developing analytical techniques for ultra-trace amounts of nuclear materials in the environmental samples in order to contribute to the strengthened safeguards system. Development of essential techniques for bulk and particle analysis of the environmental swipe sample has been established as an ultra-trace analytical method of uranium and plutonium. In January 2003, JAERI was qualified as a member of the IAEA network analytical laboratories for environmental samples. Since then, JAERI has conducted the analysis of domestic and the IAEA samples. From Japanese fiscal year 2003, the second phase of the project was started for the development of advanced techniques, such as analyzing minor actinides and fission products as well as uranium and plutonium, particle analysis using fission-track technique, more efficient particle analysis using ICP-TOFMS and screening by X-ray fluorescent analysis. This paper deals with the progress in the development of the new techniques, applications and future perspective.
Ogawa, Yuichi*; Takizuka, Tomonori; Miura, Yukitoshi; Toi, Kazuo*; Fukuda, Takeshi; Wakatani, Masahiro*; Ide, Shunsuke; Takase, Yuichi*; Tobita, Kenji; Fukuyama, Atsushi*; et al.
Purazuma, Kaku Yugo Gakkai-Shi, 77(10), p.1042 - 1048, 2001/10
no abstracts in English
Aoyama, Yoshio; Miyamoto, Yasuaki; Yamaguchi, Hiromi; Izumi, Mikio*; Naito, Susumu*; Yamamoto, Shuji*; Sano, Akira*; Nambu, Kenichi*; Takahashi, Hiroyuki*; Oda, Akinori*
no journal, ,
no abstracts in English
Miyamoto, Yasuaki; Yamaguchi, Hiromi; Naito, Susumu*; Sano, Akira*; Hirata, Yosuke*; Noda, Etsuo*; Nambu, Kenichi*; Takahashi, Hiroyuki*; Oda, Akinori*
no journal, ,
no abstracts in English
Miyamoto, Yasuaki; Yamaguchi, Hiromi; Hirata, Yosuke*; Sano, Akira*; Sato, Mitsuyoshi*; Nambu, Kenichi*; Takahashi, Hiroyuki*; Oda, Akinori*
no journal, ,
no abstracts in English
Aoyama, Yoshio; Miyamoto, Yasuaki; Yamaguchi, Hiromi; Sano, Akira*; Naito, Susumu*; Sumida, Akio*; Sato, Mitsuyoshi*; Nambu, Kenichi*; Takahashi, Hiroyuki*; Oda, Akinori*
no journal, ,
no abstracts in English
Aoyama, Yoshio; Miyamoto, Yasuaki; Yamaguchi, Hiromi; Naito, Susumu*; Sano, Akira*; Hirata, Yosuke*; Noda, Etsuo*; Sato, Mitsuyoshi*; Nambu, Kenichi*; Takahashi, Hiroyuki*; et al.
no journal, ,
no abstracts in English
Aoyama, Yoshio; Miyamoto, Yasuaki; Yamaguchi, Hiromi; Hirata, Yosuke*; Naito, Susumu*; Sano, Akira*; Nakahara, Katsuhiko*; Sato, Mitsuyoshi*; Nambu, Kenichi*; Takahashi, Hiroyuki*; et al.
no journal, ,
no abstracts in English
Aoyama, Yoshio; Miyamoto, Yasuaki; Yamaguchi, Hiromi; Naito, Susumu*; Sano, Akira*; Izumi, Mikio*; Sumida, Akio*; Maekawa, Tatsuyuki*; Sato, Mitsuyoshi*; Nambu, Kenichi*; et al.
no journal, ,
Radioactive waste contaminated by Uranium has been accumulated in front-end facilities of the nuclear fuel cycle. The purpose of the present project is to develop the practical and highly efficient measurement system, which solves the above-mentioned requirements based on the innovative concept of indirect alpha radioactivity measurement using ionized air stream transportation. The ionized air by alpha particles near the waste is peeled and transported into the ion sensor by controlling air stream in the measurement system. In order to give the actual solution for this indirect measurement concept, we have to clarify various basic physics concerning with radiation ionizing process in the air, ion reaction process in the air, ion transportation process by the turbulent air flow, and measurement process in the ion sensor. For this purpose, we have to develop various analytical simulation technologies for predicting ion behavior as well as direct measurement technologies of ion spatial distribution. The final target of the project is to establish the practical and verified clearance confirmation technology based on the above-mentioned physical and technological knowledge.
Kato, Atsushi; Negishi, Kazuo; Akiyama, Yo*; Iwasaki, Mikinori*; Miyamoto, Keiichi*; Jodai, Akira*
no journal, ,
Steel plate reinforced concrete structure are adopted as the JSFR containment vessel to shorten a construction period. This reports experimental investigation of shear strength of connecting stud.
