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Narita, Hirokazu*; Maeda, Motoki*; Tokoro, Chiharu*; Suzuki, Tomoya*; Tanaka, Mikiya*; Shiwaku, Hideaki; Yaita, Tsuyoshi
RSC Advances (Internet), 13(25), p.17001 - 17007, 2023/06
Times Cited Count:1 Percentile:51.1(Chemistry, Multidisciplinary)no abstracts in English
Dong, F.*; Chen, S.*; Demachi, Kazuyuki*; Yoshikawa, Masanori; Seki, Akiyuki; Takaya, Shigeru
Nuclear Engineering and Design, 404, p.112161_1 - 112161_15, 2023/04
Times Cited Count:4 Percentile:90.12(Nuclear Science & Technology)Collaborative Laboratories for Advanced Decommissioning Science; University of Fukui*
JAEA-Review 2022-046, 108 Pages, 2023/01
The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project (hereafter referred to "the Project") in FY2021. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. (TEPCO). For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2021, this report summarizes the research results of the "Clarification of debris formation conditions on the basis of the sampling data and experimental study using simulated fuel debris and reinforcement of the analytical results of severe accident scenario" conducted in FY2021. The research on fuel debris so far is based on TMI-2 accident that is typical PWR accident but resent scenario analysis of sever accident progression and sampling data of the in reactor materials predict that fuel debris is diversity and piled up complicatedly depending on the unit and in reactor position. We are necessary to presume the thermodynamic condition of fuel debris during the accident in order to estimate accumulation state of debris.
Yamaguchi, Tetsuji; Ohira, Saki; Hemmi, Ko; Barr, L.; Shimada, Asako; Maeda, Toshikatsu; Iida, Yoshihisa
Radiochimica Acta, 108(11), p.873 - 877, 2020/11
Times Cited Count:7 Percentile:66.68(Chemistry, Inorganic & Nuclear)Sanada, Yukihisa; Katata, Genki*; Kaneyasu, Naoki*; Nakanishi, Chika*; Urabe, Yoshimi*; Nishizawa, Yukiyasu*
Science of the Total Environment, 618, p.881 - 890, 2018/03
Times Cited Count:22 Percentile:60.8(Environmental Sciences)Although the reconstruction of atmospheric deposition processes of radiocesium during the Fukushima Daiichi Nuclear Power Station (FDNPS) accident is essential, the whole picture of the deposition mechanism in complex topography has not been well understood yet. To understand atmospheric deposition processes of aerosols over the complex mountainous topography, we analyzed altitudinal characteristics of radiocesium released during the accident. At five selected mountainous areas in the eastern Japan, altitudinal characters of air dose rate observed by our high-resolution airborne surveys after the accident was analyzed based on the results of three typical (dry, wet, and cloud water) deposition obtained from the latest atmospheric dispersion.
Yaita, Tsuyoshi
Nihon Genshiryoku Gakkai-Shi ATOMO, 59(8), p.441 - 443, 2017/08
no abstracts in English
Hanawa, Satoshi; Sumita, Junya; Shibata, Taiju; Ishihara, Masahiro; Iyoku, Tatsuo; Sawa, Kazuhiro
Transactions of 18th International Conference on Structural Mechanics in Reactor Technology (SMiRT-18), p.600 - 605, 2005/08
no abstracts in English
Furukawa, Masaru; Tokuda, Shinji
Physical Review Letters, 94(17), p.175001_1 - 175001_4, 2005/05
Times Cited Count:18 Percentile:65.5(Physics, Multidisciplinary)A ballooning perturbation in a toroidally rotating tokamaks is expanded by square-integrable eigenfunctions of an eigenvalue problem associated with ballooning modes in a static plasma. Especially a weight function is chosen such that the eigenvalue problem has only the discrete spectrum. The eigenvalues evolve in time owing to toroidal rotation shear, resulting in countably infinite number of crossings among them. The crossings cause energy transfer from an unstable mode to the infinite number of stable modes; such transfer works as the stabilization mechanism of the ballooning mode.
Tanaka, Tadao; Mukai, Masayuki; Maeda, Toshikatsu; Matsumoto, Junko; Ogawa, Hiromichi; Li, Z.*; Wang, X.*; Fan, Z.*; Guo, L.*; Liu, C.*
Journal of Radioanalytical and Nuclear Chemistry, 256(2), p.205 - 211, 2003/05
Times Cited Count:3 Percentile:25.79(Chemistry, Analytical)Migration experiments of Np(V) and Am(III) have been performed using a column system, to investigate migration behavior of Np and Am through a column packed with loess, taken from Shanxi, China. Adsorption mechanisms of Np and Am on the loess were examined by a chemical extraction method. In the case of the Np, most of Np adsorbed on the influent edge of the column. The Np adsorbed on the loess was mainly controlled by surface complexation. However, the migration of Np in the loess media could be roughly evaluated by using the distribution coefficient. In the case of the Am, particulate Am species was formed in the influent solution and moved in the column. The Am adsorbed on the loess was controlled by irreversible reactions. The migration behavior of particulate Am in the loess media could be expressed by the filtration theory.
Tanaka, Tadao; Mukai, Masayuki; Maeda, Toshikatsu; Matsumoto, Junko; Ogawa, Hiromichi; Li, S.*; Wang, Z.*; Wang, J.*; Guo, Z.*; Zhao, Y.*
JAERI-Research 2002-034, 20 Pages, 2002/12
Adsorption mechanisms and models of Sr(II), Np(V), Pu(IV) and Am(III) on the loess were investigated from their adsorption and desorption properties. The distribution coefficient of Sr and Np was 2 - 3 orders of magnitude smaller than that of Pu and Am. The adsorption of Sr and Np was mainly controlled by the ion exchange reaction. On the other hand, the adsorption of Pu and Am was mostly controlled by the selective chemical reactions with Fe and Mn oxyhydroxide/oxide and humic substances. On the basis of the experimental results, several types of adsorption models of the radionuclides, considering elemental concentrations, adsorption mechanisms and kinetics, were proposed for setting up the analytical systems of radionuclide migration in the loess media.
Sugiyama, Kenichiro*; Iguchi, Kentaro*
JAERI-Tech 2002-010, 67 Pages, 2002/03
no abstracts in English
Yamazaki, Takanori*; Seguchi, Tadao
Journal of Polymer Science, Part A; Polymer Chemistry, 38(17), p.3092 - 3099, 2000/09
no abstracts in English
Wahyuni, S.*; Hirota, Koichi; Hakoda, Teruyuki; Arai, Hidehiko; Hashimoto, Shoji; Kawamoto, Fumio*; Mukunoki, Yasuo*
Bulletin of the Chemical Society of Japan, 73(8), p.1939 - 1943, 2000/08
Times Cited Count:2 Percentile:16.96(Chemistry, Multidisciplinary)no abstracts in English
Minato, Kazuo; ; Tobita, Tsutomu*; Fukuda, Kosaku; Yoshimuta, Shigeharu*; *; *; *; *
JAERI-Research 98-070, 25 Pages, 1998/11
no abstracts in English
Sato, K.*; *; Takayanagi, Toshiyuki; *; Yokoyama, Atsushi
Journal of Chemical Physics, 106(24), p.10123 - 10133, 1997/06
Times Cited Count:31 Percentile:71.53(Chemistry, Physical)no abstracts in English
*; Fukumura, H.*; *
Reza Kenkyu, 25(4), p.288 - 295, 1997/04
no abstracts in English
Nagase, Fumihisa; Uetsuka, Hiroshi
Proc. of Int. Topical Meeting on LWR Fuel Performance, 0, p.677 - 684, 1997/03
no abstracts in English
Murao, Yoshio; Ochiai, Masaaki
Eighth Int. Topical Meeting on Nuclear Reactor Thermal-Hydraulics (NURETH-8), 2, p.1075 - 1085, 1997/00
no abstracts in English
Sugimoto, Masaki; Seguchi, Tadao; *
Proc. of RadTech Asia'97, p.410 - 413, 1997/00
no abstracts in English
Ishijima, Kiyomi; *; Fuketa, Toyoshi; Sasajima, Hideo
NEA/CSNI/R(95)22, 0, p.87 - 105, 1996/00
no abstracts in English