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Sato, Ikken; Yoshikawa, Shinji; Yamashita, Takuya; Shimomura, Kenta; Cibula, M.*; Mizokami, Shinya*
Nuclear Engineering and Design, 422, p.113088_1 - 113088_24, 2024/06
Shizuma, Toshiyuki*; Omer, M.; Hajima, Ryoichi*; Koizumi, Mitsuo
Physical Review C, 109(5), p.054320_1 - 054320_8, 2024/05
Omokawa, Marina*; Kimura, Hiroyuki*; Hatsukawa, Yuichi*; Kawashima, Hidekazu*; Tsukada, Kazuaki; Yagi, Yusuke*; Naito, Yuki*; Yasui, Hiroyuki*
Bioorganic & Medicinal Chemistry, 97, p.117557_1 - 117557_6, 2024/01
Times Cited Count:0 Percentile:0.01(Biochemistry & Molecular Biology)Kaneda-Nakashima, Kazuko*; Shirakami, Yoshifumi*; Kadonaga, Yuichiro*; Watabe, Tadashi*; Oe, Kazuhiro*; Yin, X.*; Haba, Hiromitsu*; Shirasaki, Kenji*; Kikunaga, Hidetoshi*; Tsukada, Kazuaki; et al.
International Journal of Molecular Sciences (Internet), 25(2), p.933_1 - 933_14, 2024/01
Times Cited Count:1 Percentile:95.46(Biochemistry & Molecular Biology)Katabuchi, Tatsuya*; Sato, Yaoki*; Takebe, Karin*; Igashira, Masayuki*; Umezawa, Seigo*; Fujioka, Ryo*; Saito, Tatsuhiro*; Iwamoto, Nobuyuki
Journal of Nuclear Science and Technology, 6 Pages, 2024/00
Times Cited Count:0 Percentile:0.08(Nuclear Science & Technology)Tatsuno, Takahiro*; Yoshimura, Kazuya; Nihei, Naoto*
Journal of Radioanalytical and Nuclear Chemistry, 8 Pages, 2024/00
Times Cited Count:0 Percentile:0.08(Chemistry, Analytical)Endo, Shunsuke; Kawamura, Shiori*; Okudaira, Takuya*; Yoshikawa, Hiromoto*; Rovira Leveroni, G.; Kimura, Atsushi; Nakamura, Shoji; Iwamoto, Osamu; Iwamoto, Nobuyuki
European Physical Journal A, 59(12), p.288_1 - 288_12, 2023/12
Times Cited Count:0 Percentile:0.02(Physics, Nuclear)no abstracts in English
Toyota, Kodai; Imagawa, Yuya; Onizawa, Takashi; Kato, Shoichi; Furuya, Yoshiyuki*
Nihon Kikai Gakkai Rombunshu (Internet), 89(928), p.23-00206_1 - 23-00206_15, 2023/12
In order to design fast reactors, it is necessary to consider high cycle fatigue of structural materials up to 110 cycles; to evaluate high cycle fatigue at 110 cycles, it is necessary to develop a best-fit fatigue curve applicable up to 110 cycles. In this study, high cycle fatigue tests were conducted under strain-controlled conditions and ultrasonic fatigue tests were also conducted to develop a high cycle fatigue evaluation method for Mod.9Cr-1Mo steel, which is a candidate material for fast reactor structural materials. Based on the test results, the best-fit fatigue curves were extended and the applicability of the JSME best-fit fatigue curves up to 110 cycles was verified.
Machida, Masahiko; Iwata, Ayako; Yamada, Susumu; Otosaka, Shigeyoshi*; Kobayashi, Takuya; Funasaka, Hideyuki*; Morita, Takami*
Nihon Genshiryoku Gakkai Wabun Rombunshi (Internet), 22(4), p.119 - 139, 2023/11
We estimate monthly discharged inventory of Sr from port of Fukushima Daiichi Nuclear Power Plant (1F) from Jun. 2013 to Mar. 2022 by using the Voronoi tessellation method inside the port, following the monitoring of Sr sea water radioactivity concentration inside the port. The results suggest that the closure of sea side impermeable wall is the most effective for the reduction of discharged one. In addition, the results roughly reveal the monthly discharged inventory required to observe visible enhancement of the sea radioactivity concentration from the background level in each area. Such outcome is significant for considering environmental impacts on the planned future releasing of the treated water accumulated in 1F site.
Kim, M.; Malins, A.*; Machida, Masahiko; Yoshimura, Kazuya; Saito, Kimiaki; Yoshida, Hiroko*
Nihon Genshiryoku Gakkai Wabun Rombunshi (Internet), 22(4), p.156 - 169, 2023/11
Dose reduction factor of a Japanese house is important information in the external exposure estimation of returning residents. In 2019, a total of 19 wooden houses were surveyed in Iitate Village and Namie Town using a gamma plotter that can continuously measure the air dose rate. In addition, the characteristics of the reduction factor were investigated from the measured air dose rate. In the vicinity of houses, uncontaminated areas exist underneath houses and, the ratio of paved surfaces such as asphalt roads is relatively high; furthermore, the pavement has a tendency for the radiation source to decay quickly. Therefore, the air dose rate near the house showed a relatively low value in common at all sites. Air dose rates above unpaved surfaces showed higher values and larger variations than those above paved surfaces within a radius of 50 m form the center of a house. The reduction factor was widely distributed even for one house, if the ratio of every air dose rate observed inside and outside the house is considered. It is suggested that a realistic reduction factor may not be obtained when the reduction factor is obtained based on the measured values at a small number of points that do not have the representativeness of the radiation field to be measured.
Furutaka, Kazuyoshi; Ozu, Akira; Toh, Yosuke
Nuclear Engineering and Technology, 55(11), p.4002 - 4018, 2023/11
Times Cited Count:0 Percentile:0.01(Nuclear Science & Technology)Hirano, Tatsumi*; Maeda, Takehiro*; Murata, Tetsuyuki*; Yamamoto, Takahiro*; Matsubara, Eiichiro*; Shobu, Takahisa; Shiro, Ayumi*; Yasuda, Ryo*; Takamatsu, Daiko*
SPring-8/SACLA Riyo Kenkyu Seikashu (Internet), 11(5), p.345 - 353, 2023/10
no abstracts in English
Ikenoue, Tsubasa; Shimadera, Hikari*; Nakanishi, Takahiro; Kondo, Akira*
Water (Internet), 15(15), p.2734_1 - 2734_18, 2023/08
Times Cited Count:0 Percentile:0(Environmental Sciences)The Fukushima Daiichi Nuclear Power Plant accident caused an accumulation of Cs in coastal sediment. The Cs supply from rivers to the ocean can affect the long-term fate of Cs in coastal sediment. Since the Fukushima coastal river basins include large decontaminated and evacuation order areas, considering the decontamination work and resumption of agriculture is important for predicting the Cs supply. We conducted a 30-year prediction of the Cs supply from the Fukushima coastal rivers to the ocean using a distributed radiocesium prediction model, considering the effects of human activities. In river basins with decontaminated and evacuation order areas, human activities reduced the total Cs outflow from agricultural lands, urban lands, and forest areas to the rivers and the Cs supply to the ocean by 5.0% and 6.0%, respectively. These results indicated that human activities slightly impacted the Cs outflow and supply. The Cs supply from rivers impacted by the accident to the coastal sediment was estimated to correspond to 11-36% of the total Cs in the coastal sediment in the early phase of the accident. Therefore, the Cs supply from rivers to the ocean is important for the long-term behavior of Cs in coastal sediment.
Hidaka, Akihide; Kawashima, Shigeto*; Kajino, Mizuo*
Journal of Nuclear Science and Technology, 60(7), p.743 - 758, 2023/07
Times Cited Count:2 Percentile:87.3(Nuclear Science & Technology)An accurate estimation of radionuclides released during the Fukushima accident is essential. Therefore, authors investigated Te release using the Unit emission-regression estimation method, in which the deposition distribution is weighted based on the hourly deposition obtained from mesoscale meteorological model calculations assuming Unit emissions. The previous study focused on confirming the applicability of this method. Subsequent examination revealed that if any part of the time when a release have occurred is missing from the estimated release period, the entire source term calculation will be distorted. Therefore, this study performed the recalculation by extending the estimation period to cover all major releases. Consequently, unspecified release events were clarified, and their correspondence to in-core events was confirmed. The Te release caused by Zr cladding complete oxidation can explain the regional dependence of the Te/Cs ratio in the soil contamination map.
Kimura, Atsushi; Nakamura, Shoji; Endo, Shunsuke; Rovira Leveroni, G.; Iwamoto, Osamu; Iwamoto, Nobuyuki; Harada, Hideo; Katabuchi, Tatsuya*; Terada, Kazushi*; Hori, Junichi*; et al.
Journal of Nuclear Science and Technology, 60(6), p.678 - 696, 2023/06
Times Cited Count:2 Percentile:50.96(Nuclear Science & Technology)Tatsuno, Takahiro*; Nihei, Naoto*; Yoshimura, Kazuya; Ote, Nobuhito*
Journal of Radioanalytical and Nuclear Chemistry, 332(6), p.1677 - 1686, 2023/06
Times Cited Count:1 Percentile:68.31(Chemistry, Analytical)Kokubu, Yoko; Fujita, Natsuko; Watanabe, Takahiro; Matsubara, Akihiro; Ishizaka, Chika; Miyake, Masayasu*; Nishio, Tomohiro*; Kato, Motohisa*; Ogawa, Yumi*; Ishii, Masahiro*; et al.
Nuclear Instruments and Methods in Physics Research B, 539, p.68 - 72, 2023/06
Times Cited Count:0 Percentile:0.02(Instruments & Instrumentation)The JAEA-AMS-TONO facility at the Tono Geoscience Center, JAEA has an accelerator mass spectrometer (JAEA-AMS-TONO-5MV). The spectrometer enabled us to use a multi-nuclide AMS of carbon-14 (C), beryllium-10, aluminium-26 and iodine-129, and we have recently been proceeding test measurement of chlorine-36. In response to an increase of samples, we installed a state-of-the-art multi-nuclide AMS with a 300 kV Tandetron accelerator in 2020. Recently, we are driving the development of techniques of isobar separation in AMS and of sample preparation. Ion channeling is applied to remove isobaric interference and we are building a prototype AMS based on this technique for downsizing of AMS. The small sample graphitization for C has been attempted using an automated graphitization equipment equipped with an elemental analyzer.
Taira, Yoshitaka*; Endo, Shunsuke; Kawamura, Shiori*; Nambu, Taro*; Okuizumi, Mao*; Shizuma, Toshiyuki*; Omer, M.; Zen, H.*; Okano, Yasuaki*; Kitaguchi, Masaaki*
Physical Review A, 107(6), p.063503_1 - 063503_10, 2023/06
Times Cited Count:0 Percentile:0.01(Optics)no abstracts in English
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:44.81(Chemistry, Multidisciplinary)no abstracts in English
Ikenoue, Tsubasa; Shimadera, Hikari*; Nakanishi, Takahiro; Kondo, Akira*
Science of the Total Environment, 876, p.162846_1 - 162846_12, 2023/06
Times Cited Count:2 Percentile:68.68(Environmental Sciences)We conducted 30 years simulation of environmental fate of Cs in the Abukuma River basin considering the characteristics of the Cs behavior in land uses. Overall, in the Abukuma River basin, the Cs transported into the ocean for 30 years was estimated to correspond to 4.6% of the initial deposition in the basin, and the effective half-life of Cs deposited in the basin was estimated to be 3.7 years shorter (by 11.6%) than its physical half-life. These results suggested that Cs deposited from the accident could still remain for decades. Based on the analysis of the Cs behavior in land use, in 2011, the contribution of Cs export to the ocean from urban lands was estimated to correspond to 70% of the total Cs export. Meanwhile, from 2012 to 2040, the contribution of Cs export from agricultural lands was estimated to correspond to 75% of the total Cs export. The reduction ratios excluding radioactive decay of Cs remained in areas with and without human activities for 30 years after the accident, defined as the ratios of the total outflow to the initial deposition, were estimated to be 11.5%-17.7% and 0.4%-1.4%, respectively. These results suggested that human activities enhance the reduction of Cs remaining in land in the past and future.