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Tamura, Koji; Nakanishi, Ryuzo; Oba, Hironori; Karino, Takahiro; Shibata, Takuya; Taira, Takunori*; Wakaida, Ikuo
Journal of Nuclear Science and Technology, 8 Pages, 2024/00
Times Cited Count：0 Percentile：0.01(Nuclear Science & Technology)Nakanishi, Takumi*; Hori, Yuta*; Shigeta, Yasuteru*; Sato, Hiroyasu*; Kiyanagi, Ryoji; Munakata, Koji*; Ohara, Takashi; Okazawa, Atsushi*; Shimada, Rintaro*; Sakamoto, Akira*; et al.
Journal of the American Chemical Society, 145(35), p.19177 - 19181, 2023/08
Times Cited Count：1 Percentile：0(Chemistry, Multidisciplinary)Nakanishi, Takumi*; Hori, Yuta*; Shigeta, Yasuteru*; Sato, Hiroyasu*; Wu, S.-Q.*; Kiyanagi, Ryoji; Munakata, Koji*; Ohara, Takashi; Sato, Osamu*
Physical Chemistry Chemical Physics, 25(17), p.12394 - 12400, 2023/05
Times Cited Count：1 Percentile：50.66(Chemistry, Physical)Kitamura, Akihisa*; Okazaki, Sota*; Kondo, Mitsuru*; Watanabe, Takahiro; Nakanishi, Toshimichi*; Hori, Rie*; Ikeda, Masayuki*; Ichimura, Koji; Nakagawa, Yuki; Mori, Hideki*
Shizuoka Daigaku Chikyu Kagaku Kenkyu Hokoku, (49), p.73 - 86, 2022/07
On July 3 2021, a debris flow caused by a landslide from a landfill occurred along the Aizome River in the Izusan area of Atami City, Shizuoka. In this study, debris flow deposits and soil samples were characterized in terms of their sedimentology and geochemically analyzed.
Oto, Tsutomu; Asano, Norikazu; Kawamata, Takanori; Yanai, Tomohiro; Nishimura, Arashi; Araki, Daisuke; Otsuka, Kaoru; Takabe, Yugo; Otsuka, Noriaki; Kojima, Keidai; et al.
JAEA-Review 2020-018, 66 Pages, 2020/11
JAEA-Review-2020-018.pdf:8.87MB
A collapse event of the cooling tower of secondary cooling system in the JMTR (Japan Materials Testing Reactor) was caused by the strong wind of Typhoon No.15 on September 9, 2019. The cause of the collapse of the cooling tower was investigated and analyzed. As the result, it was identified that four causes occurred in combination. Thus, the soundness of the cooling tower of Utility Cooling Loop (UCL cooling tower), which is a wooden cooling tower installed at the same period as the cooling tower of secondary cooling system, was investigated. The items of soundness survey are to grasp the operation conditions of the UCL cooling tower, to confirm the degradation of structural materials, the inspection items and inspection status of the UCL cooling tower, and to investigate the past meteorological data. As the results of soundness survey of the UCL cooling tower, the improvement of inspection items of the UCL cooling tower was carried out and the replacement and repair of the structural materials of the UCL cooling tower were planned for safe maintenance and management of this facility. And the renewal plan of new cooling tower was created to replace the existing UCL cooling tower. This report is summarized the soundness survey of the UCL cooling tower.
Shimizu, Takeshi*; Wang, H.*; Tanifuji, Naoki*; Matsumura, Daiju; Yoshimura, Masashi*; Nakanishi, Koji*; Ota, Toshiaki*; Yoshikawa, Hirofumi*
Chemistry Letters, 47(5), p.678 - 681, 2018/05
Times Cited Count：9 Percentile：33.47(Chemistry, Multidisciplinary)
Cs redistribution in the Oginosawa River catchment near the Fukushima Dai-ichi Nuclear Power Plant using integrated watershed modelingSakuma, Kazuyuki; Malins, A.; Funaki, Hironori; Kurikami, Hiroshi; Niizato, Tadafumi; Nakanishi, Takahiro; Mori, Koji*; Tada, Kazuhiro*; Kobayashi, Takamaru*; Kitamura, Akihiro; et al.
Journal of Environmental Radioactivity, 182, p.44 - 51, 2018/02
Times Cited Count：11 Percentile：37.1(Environmental Sciences)The Oginosawa River catchment lies 15 km south-west of the Fukushima Dai-ichi nuclear plant. The General-purpose Terrestrial Fluid-flow Simulator (GETFLOWS) code was used to study sediment and Cs redistribution within the catchment. Cesium-137 input to watercourses came predominantly from land adjacent to river channels and forest gullies. Forested areas far from the channels only made a minor contribution to Cs input to watercourses, total erosion of between 0.001-0.1 mm from May 2011 to December 2015. The 2.3-6.9% y
decrease in the amount of Cs in forest topsoil over the study period can be explained by radioactive decay (approximately 2.3% y), along with a migration downwards into subsoil and a small amount of export. The amount of Cs available for release from land adjacent to rivers is expected to be lower in future than compared to this study period, as the simulations indicate a high depletion of inventory from these areas.
Numata, Naoto*; Asakawa, Tomoyuki*; Sakai, Hiroshi*; Umemori, Kensei*; Furuya, Takaaki*; Shinoe, Kenji*; Enami, Kazuhiro*; Egi, Masato*; Sakanaka, Shogo*; Michizono, Shinichiro*; et al.
Proceedings of 12th Annual Meeting of Particle Accelerator Society of Japan (Internet), p.566 - 570, 2015/09
no abstracts in English
Furuya, Takaaki*; Hara, Kazufumi*; Hosoyama, Kenji*; Kojima, Yuji*; Nakai, Hirotaka*; Nakanishi, Kota*; Sakai, Hiroshi*; Umemori, Kensei*; Sawamura, Masaru; Shinoe, Kenji*
Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.2923 - 2925, 2010/05
A prototype module including a couple of 1.3 GHz superconducting 9-cell cavities has been designed as the main linac of cERL which is the test facility to establish the basic ERL technology at KEK. The shape of 9-cell Nb structure is optimized to accelerate a CW beam of 100 mA with sufficiently damped higher order modes (HOM) which is achieved by adopting an eccentric fluted beam pipe and a cylindrical beam pipe of a large diameter of 120 mm. Extracted HOMs are absorbed by the ferrite cylinders bonded on the copper beam pipes by HIP process. A power coupler with double disk-ceramics has been developed to transfer an RF of 20 kW CW to the cavity in full reflection. The test results of fabrication, cooling and RF performance for these components are integrated as the prototype module of the main linac for cERL facility.
Sakanaka, Shogo*; Akemoto, Mitsuo*; Aoto, Tomohiro*; Arakawa, Dai*; Asaoka, Seiji*; Enomoto, Atsushi*; Fukuda, Shigeki*; Furukawa, Kazuro*; Furuya, Takaaki*; Haga, Kaiichi*; et al.
Proceedings of 1st International Particle Accelerator Conference (IPAC '10) (Internet), p.2338 - 2340, 2010/05
Future synchrotron light source using a 5-GeV energy recovery linac (ERL) is under proposal by our Japanese collaboration team, and we are conducting R&D efforts for that. We are developing high-brightness DC photocathode guns, two types of cryomodules for both injector and main superconducting (SC) linacs, and 1.3 GHz high CW-power RF sources. We are also constructing the Compact ERL (cERL) for demonstrating the recirculation of low-emittance, high-current beams using above-mentioned critical technologies.
Ishikawa, Satoru*; Arao, Tomohito*; Baba, Koji*; Mori, Shinsuke*; Nishizawa, Naoko*; Nakanishi, Hiromi*; Yoshihara, Ryohei; Hase, Yoshihiro
JAEA-Review 2008-055, JAEA Takasaki Annual Report 2007, P. 80, 2008/11
no abstracts in English
Chikazawa, Yoshitaka; Okano, Yasushi; Konomura, Mamoru; Sato, Koji; Sawa, Naoki*; Sumita, Hiroyuki*; Nakanishi, Shigeyuki*; Ando, Masato*
Nuclear Technology, 159(3), p.267 - 278, 2007/09
Times Cited Count：1 Percentile：11.31(Nuclear Science & Technology)A diversified or modular power source is attractive since it requires a low construction cost per unit and can be demonstrated in small scale experimental facilities. In this study, a new metal fuel sodium cooled reactor with 300MW electric has been developed enhancing cost reduction. And economical potential at demonstration stage with first of a kind (FOAK) is emphasized. A minimum configuration with a compact reactor vessel, a one-loop main cooling system and a simple fuel handling system is adopted enhancing cost reduction. For safety evaluation, reliability of the one-loop main cooling system has been shown by pipe-break transient analyses. Besides, construction cost of a demonstration plant with a first reactor and a small reprocessing and fuel fabrication facility is also evaluated. A major feature of the present concept is that the demonstration reactor and facilities can be directly appropriated for first commercial modules and the power plant can easily increase its capacity adding reactor and electrorefiner modules. A fast reactor cycle commercialization scenario using the present concept is thought to give low R&D or investment risk and high cost performance since the total demonstration plant cost is relatively small and the facilities are directly appropriated to commercial use.
Sato, Fuminori; Mizuguchi, Koji; Nakanishi, Shigeyuki; Myochin, Munetaka
Nihon Genshiryoku Gakkai Wabun Rombunshi, 5(4), p.268 - 281, 2006/12
MOX co-deposition process, which is one of the main parts of oxide electrowinning process, was studied by both sides of examination and analysis. Parameter tests using U and Pu were performed as basic examination, and fundamental data of the process such as polarization property of molten salt including U and Pu, current efficiency of electrolysis and PuO
concentration in recovered deposit, etc. were acquired. In addition, to analyze the process behavior, especially polarization property at electrolysis, a reaction model considering Pu
, Pu
, UO
, UO
, PuO and PuOin molten NaCl-2CsCl salt was developed. The validity of this model was confirmed by comparison of the experimental and analytical results. Using this model behavior of chemical species in the process was studied and control factors of MOX co-deposition process were discussed.
Chikazawa, Yoshitaka; Okano, Yasushi; Konomura, Mamoru; Sato, Koji; Ando, Masato*; Nakanishi, Shigeyuki*; Sawa, Naoki*; Shimakawa, Yoshio*
Proceedings of 2006 International Congress on Advances in Nuclear Power Plants (ICAPP '06) (CD-ROM), 8 Pages, 2006/06
A diversified or modular power source is attractive since it requires a low construction cost per unit and can be demonstrated in small scale experimental facilities. In this study, a new metal fuel sodium cooled reactor with 300MW electric has been developed enhancing cost reduction. And economical potential at demonstration stage with first of a kind (FOAK) is emphasized. A minimum configuration with a compact reactor vessel, a one-loop main cooling system and a simple fuel handling system are adopted enhancing cost reduction within safety requirement. Besides, construction cost of a demonstration plant with a first kind of reactor and a small reprocessing and fuel manufacturing facility is also evaluated. A major feature of the present concept is that the demonstration facilities can be appropriated for commercialized ones since they can be easily commercialize by increasing reactor and electrorefiner modules. A FBR cycle commercialization scenario using the present concept is thought to give low risk and high cost performance since the total demonstration plant cost is relatively small and the facilities are directly appropriated to commercial use.
Kotaki, Hideyuki; Nakajima, Kazuhisa*; Kando, Masaki*; Dewa, Hidenori*; Kondo, Shuji; *; Watanabe, Takahiro*; Ueda, Toru*; Nakanishi, Hiroshi*; Yoshii, Koji*; et al.
Inst. Phys. Conf. Ser., (159), p.565 - 567, 1999/00
no abstracts in English
Kando, Masaki; Kotaki, Hideyuki; Dewa, Hidenori; Kondo, Shuji; Yoshii, Koji*; Ueda, Toru*; Watanabe, Takahiro*; Uesaka, Mitsuru*; Sakai, Fumio*; Ogata, Atsushi*; et al.
Proceedings of 24th Linear Accelerator Meeting in Japan, p.128 - 130, 1999/00
no abstracts in English
Nakajima, Kazuhisa; Nakanishi, Hiroshi*; Ogata, Atsushi*; Harano, Hideki*; Ueda, Toru*; Uesaka, Mitsuru*; Watanabe, Takahiro*; Yoshii, Koji*; Dewa, Hidenori; Hosokai, Tomonao; et al.
Proceedings of 6th European Particle Accelerator Conference (EPAC98) (CD-ROM), p.809 - 811, 1998/01
no abstracts in English
Dewa, Hidenori*; H.Ahn*; Harano, Hideki*; Kando, Masaki*; Kinoshita, Kenichi*; Kondo, Shuji; Kotaki, Hideyuki; Nakajima, Kazuhisa*; Nakanishi, Hiroshi*; Ogata, Atsushi*; et al.
Nuclear Instruments and Methods in Physics Research A, 410(3), p.357 - 363, 1998/00
Times Cited Count：40 Percentile：92.81(Instruments & Instrumentation)no abstracts in English
Kotaki, Hideyuki; Nakajima, Kazuhisa*; Kando, Masaki*; H.Ahn*; Dewa, Hidenori*; Kondo, Shuji; *; Watanabe, Takahiro*; Ueda, Toru*; Nakanishi, Hiroshi*; et al.
Proc. of 11th Symp. on Accelerator Sci. and Technol., p.449 - 451, 1997/00
no abstracts in English
*; Kotaki, Hideyuki; Nakajima, Kazuhisa*; Kando, Masaki*; Kondo, Shuji; Dewa, Hidenori*; Watanabe, Takahiro*; Ueda, Toru*; Yoshii, Koji*; Kinoshita, Kenichi*; et al.
Proc. of 11th Symp. on Accelerator Sci. and Technol., p.473 - 475, 1997/00
no abstracts in English
