Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Nagao, Fumiya; Niizato, Tadafumi; Sasaki, Yoshito; Ito, Satomi; Watanabe, Takayoshi; Dohi, Terumi; Nakanishi, Takahiro; Sakuma, Kazuyuki; Hagiwara, Hiroki; Funaki, Hironori; et al.
JAEA-Research 2020-007, 249 Pages, 2020/10
JAEA-Research-2020-007.pdf:15.83MB
The accident of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. occurred due to the Great East Japan Earthquake, Sanriku offshore earthquake, of 9.0 magnitude and the accompanying tsunami. As a result, large amount of radioactive materials was released into the environment. Under these circumstances, Japan Atomic Energy Agency (JAEA) has been conducting "Long-term Assessment of Transport of Radioactive Contaminants in the Environment of Fukushima" concerning radioactive materials released in environment, especially migration behavior of radioactive cesium since November 2012. This report is a summary of the research results that have been obtained in environmental dynamics research conducted by JAEA in Fukushima Prefecture.
Nagao, Fumiya; Niizato, Tadafumi; Sasaki, Yoshito; Ito, Satomi; Watanabe, Takayoshi; Dohi, Terumi; Nakanishi, Takahiro; Sakuma, Kazuyuki; Hagiwara, Hiroki; Funaki, Hironori; et al.
JAEA-Research 2019-002, 235 Pages, 2019/08
JAEA-Research-2019-002.pdf:21.04MB
The accident of the Fukushima Daiichi Nuclear Power Station (hereinafter referred to 1F), Tokyo Electric Power Company Holdings, Inc. occurred due to the Great East Japan Earthquake, Sanriku offshore earthquake, of 9.0 magnitude and the accompanying tsunami. As a result, large amount of radioactive materials was released into the environment. Under these circumstances, JAEA has been conducting Long-term Environmental Dynamics Research concerning radioactive materials released in environment, especially migration behavior of radioactive cesium since November 2012. This report is a summary of the research results that have been obtained in environmental dynamics research conducted by JAEA in Fukushima Prefecture.
Kitamura, Akihiro; Kurikami, Hiroshi; Sakuma, Kazuyuki; Malins, A.; Okumura, Masahiko; Machida, Masahiko; Mori, Koji*; Tada, Kazuhiro*; Tawara, Yasuhiro*; Kobayashi, Takamaru*; et al.
Earth Surface Processes and Landforms, 41(12), p.1708 - 1726, 2016/09
Times Cited Count：16 Percentile：52.9(Geography, Physical)Sediment erosion and transport processes that are considered to be important in predicting the future radioactive material distribution through sediment-sorbed form in Fukushima Prefecture are simulated. Since large portion of the sediment is considered to be supplied into the rivers, it is important to trace their migration process in terms of each river basin. We choose five river basins, namely the Odaka, the Ukedo, the Maeda, the Kuma, and the Tomioka, from north to south, because of their importance in contamination aspects and prediction studies. The results are summarized as comprehensive dataset of sediment migration for particular river basins in typical typhoon events that account for the most of annual soil erosion. Detail calculations implemented for the amount of sediment supplied in to the river, deposited on river and dam beds, and exported to the ocean.
C-carbon fiber composite irradiated with low energy deuterium ionsJimbo, Ryutaro*; Nakamura, Kazuyuki; Bandourko, V.*; Dairaku, Masayuki; Okumura, Yoshikazu; Akiba, Masato
Journal of Nuclear Materials, 266-269, p.1103 - 1107, 1999/00
Times Cited Count：5 Percentile：40.64(Materials Science, Multidisciplinary)no abstracts in English
Nakamura, Kazuyuki; ; Dairaku, Masayuki; ; Okumura, Yoshikazu; *; Jimbo, Ryutaro*; Bandourko, V.*; Akiba, Masato
Journal of Nuclear Materials, 258-263, p.828 - 832, 1998/00
Times Cited Count：4 Percentile：38.68(Materials Science, Multidisciplinary)no abstracts in English
Jimbo, Ryutaro*; Nakamura, Kazuyuki; Bandourko, V.*; Okumura, Yoshikazu; Akiba, Masato
Journal of Nuclear Materials, 258-263, p.724 - 728, 1998/00
Times Cited Count：8 Percentile：57.28(Materials Science, Multidisciplinary)no abstracts in English
C doped CFC under high particle flux with low energyNakamura, Kazuyuki; Dairaku, Masayuki; Akiba, Masato; Okumura, Yoshikazu
Journal of Nuclear Materials, 241-243, p.1142 - 1146, 1997/00
Times Cited Count：9 Percentile：60.17(Materials Science, Multidisciplinary)no abstracts in English
Sato, Kazuyoshi; ; Araki, Masanori; Nakamura, Kazuyuki; Watanabe, Kazuhiro; ; Dairaku, Masayuki; Okumura, Yoshikazu; Ohara, Yoshihiro; Akiba, Masato
16th IEEE/NPSS Symp. on Fusion Engineering (SOFE '95), 1, p.220 - 223, 1995/00
no abstracts in English
Nakamura, Kazuyuki; *; Dairaku, Masayuki; Akiba, Masato; Araki, Masanori; Okumura, Yoshikazu
Journal of Nuclear Materials, 220-222, p.890 - 894, 1995/00
Times Cited Count：19 Percentile：84.39(Materials Science, Multidisciplinary)no abstracts in English
*; Nakamura, Kazuyuki; Okumura, Yoshikazu; Shinto, Katsuhiro*
Dai-4-Kai Ryushisen No Sentanteki Oyo Gijutsu Ni Kansuru Shimpojiumu, p.19 - 22, 1993/00
no abstracts in English
Nakamura, Hiroo; Ida, Mizuho; Miyashita, Makoto; Yoshida, Eiichi; Ara, Kuniaki; Nishitani, Takeo; Okumura, Yoshikazu; Horiike, Hiroshi*; Kondo, Hiroo*; Terai, Takayuki*; et al.
no journal, ,
no abstracts in English
Kitamura, Akihiro; Kurikami, Hiroshi; Sakuma, Kazuyuki; Malins, A.; Okumura, Masahiko; Itakura, Mitsuhiro; Yamada, Susumu; Machida, Masahiko
no journal, ,
Radioactive cesium that was deposited over Fukushima after the accident at the FDNPP is one of the major concerns regarding health physics. In order to predict the future distribution of radioactive cesium and resulting air dose rate at any location in Fukushima, we have integrated a number of mathematical models covering different time and scales. We present simulation results of sediment movement and radioactive cesium migration using semi empirical and physics based watershed models, and that of sediment and radioactive cesium behavior in a dam reservoir using one and two dimensional river simulation models. We also present a tool for calculating air dose rates from arbitrary radio cesium depth profiles and spatial distributions. The predicted dose rates were compared against dose rates measured in the field with handheld survey meters and good correlation was found between the two.
Hirooka, Shun; Okumura, Kazuyuki; Makino, Takayoshi
no journal, ,
no abstracts in English
Nishina, Masahiro; Takato, Kiyoto; Nakamichi, Shinya; Segawa, Tomoomi; Kawaguchi, Koichi; Ishii, Katsunori; Makino, Takayoshi; Okumura, Kazuyuki
no journal, ,
no abstracts in English
Hirooka, Shun; Horii, Yuta; Segawa, Tomoomi; Kawaguchi, Koichi; Ishii, Katsunori; Makino, Takayoshi; Okumura, Kazuyuki
no journal, ,
no abstracts in English
Horii, Yuta; Hirooka, Shun; Kato, Masato; Uno, Hiroki*; Ogasawara, Masahiro*; Tamura, Tetsuya*; Yamada, Tadahisa*; Okumura, Kazuyuki
no journal, ,
As part of studies on physical properties of low-decontaminated fuel pellets, simulated FPs (Sm
O
and NdO) and impurities included at such as fuel fabrication process (AlO and SiO) were added to MOX, and their effects on thermal conductivity were evaluated. Addition of SmO and NdO in MOX, that can be solutionized, decreased thermal conductivity whereas addition of AlO and SiO, that don't make a solid solution with MOX, increased thermal conductivity.
Takato, Kiyoto; Nishina, Masahiro; Tsuchimochi, Ryota; Hayashizaki, Kohei; Segawa, Tomoomi; Kawaguchi, Koichi; Ishii, Katsunori; Makino, Takayoshi; Okumura, Kazuyuki
no journal, ,
no abstracts in English
Nakamichi, Shinya; Sunaoshi, Takeo*; Uno, Hiroki*; Yamada, Tadahisa*; Okumura, Kazuyuki
no journal, ,
no abstracts in English
Segawa, Tomoomi; Kawaguchi, Koichi; Ishii, Katsunori; Yamamoto, Kazuya; Makino, Takayoshi; Okumura, Kazuyuki
no journal, ,
In previous studies, although a tendency for voids to form around dry recovered powder particles has been observed from the metallography of sintered pellets, it has been difficult to completely distinguish the areas derived from dry recovered powder particles from those derived from raw powder. In this study, for the purpose of clarifying the mechanism of the control of the pellet sintering density by dry recovered powder, and to identify the area in the sintered pellets derived from simulated dry recovered powder, (Ce,Zr)O sintered pellets with zirconium oxide (ZrO) added as a tracer in CeO was milled and particle size adjusted to obtain (Ce,Zr)O simulated dry recovered powder was used as a parameter for the particle size distribution and the mixing ratio of CeO raw powder and simulated dry recovered powder to form and sintered pellets, and the microstructure of the pellets was evaluated.
Goto, Kenta; Hirooka, Shun; Horii, Yuta; Nakamichi, Shinya; Murakami, Tatsutoshi; Shibanuma, Kimikazu; Ono, Takanori; Yamamoto, Kazuya; Hatanaka, Nobuhiro; Okumura, Kazuyuki
no journal, ,
no abstracts in English
Segawa, Tomoomi; Takashima, Hayato; Yamamoto, Kazuya; Ono, Takanori; Okumura, Kazuyuki; Kawaguchi, Koichi; Ishii, Katsunori
no journal, ,
In the pulverizing process of dry recycled powder on a mass production scale, pulverizing equipment with a classifying function is required to efficiently obtain a dry recycled powder that does not contain particles with excessive particle diameters. Since the maximum particle diameter tends to increase as the feed rate of raw material powder increases, focusing on the classification method, pulverization tests were performed on a mass production scale using collision plate-type jet mill and spiral jet mill with a classifying function. The results of these tests showed that the tendency of the maximum particle diameter to increase with increasing feed rate of the simulated raw material powders was different for each of the jet mill. This is considered to be attributable to differences in the characteristics of the classifying function of each mill.
