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-edge to assess the U(V) electronic structure in FeUO
Yomogida, Takumi; Akiyama, Daisuke*; Ouchi, Kazuki; Kumagai, Yuta; Higashi, Kotaro*; Kitatsuji, Yoshihiro; Kirishima, Akira*; Kawamura, Naomi*; Takahashi, Yoshio*
Inorganic Chemistry, 61(50), p.20206 - 20210, 2022/12
Times Cited Count：2 Percentile：36.89(Chemistry, Inorganic & Nuclear)FeUO was studied to clarify the electronic structure of U(V) in a metal monouranate compound. We obtained the peak splitting of HERFD-XANES spectra utilizing high-energy-resolution fluorescence detection-X-ray absorption near edge structure (HERFD-XANES) spectroscopy at the U L-edge, which is a novel technique in the U(V) compounds. Theoretical calculations revealed that the peak splitting was caused by splitting the 6d orbital of U(V). Such distinctive electronic states are of major interest to researchers and engineers working in various fields, from fundamental physics to the nuclear industry and environmental sciences for actinide elements.
CsUchiyama, Yusuke*; Tokunaga, Natsuki*; Azuma, Kohei*; Kamidaira, Yuki; Tsumune, Daisuke*; Iwasaki, Toshiki*; Yamada, Masatoshi*; Tateda, Yutaka*; Ishimaru, Takashi*; Ito, Yukari*; et al.
Science of the Total Environment, 816, p.151573_1 - 151573_13, 2022/04
Times Cited Count：7 Percentile：68.71(Environmental Sciences)no abstracts in English
Tojo, Masayuki*; Kanazawa, Toru*; Nakashima, Kazuo*; Iwamoto, Tatsuya*; Kobayashi, Kensuke*; Goto, Daisuke*; Nemoto, Yoshiyuki; Kaji, Yoshiyuki
Proceedings of 27th International Conference on Nuclear Engineering (ICONE-27) (Internet), 13 Pages, 2019/05
In this study, fuel loading effects in BWR spent fuel rack accidents are widely investigated using three-dimensional analysis methods from both nuclear and thermal hydraulics viewpoints, including: (a) Decay heat of spent fuel after discharge, (b) The maximum temperature of spent fuel cladding in the spent fuel rack depending on heat transfer phenomena, and (c) Criticality of the spent fuel rack after collapsing of the fuel due to a severe accidents in the BWR spent fuel pool (SFP).
Kaji, Yoshiyuki; Nemoto, Yoshiyuki; Nagatake, Taku; Yoshida, Hiroyuki; Tojo, Masayuki*; Goto, Daisuke*; Nishimura, Satoshi*; Suzuki, Hiroaki*; Yamato, Masaaki*; Watanabe, Satoshi*
Proceedings of 27th International Conference on Nuclear Engineering (ICONE-27) (Internet), 8 Pages, 2019/05
In this research program, cladding oxidation model in SFP accident condition, and numerical simulation method to evaluate capability of spray cooling system which was deployed for spent fuel cooling during SFP accident, have been developed. These were introduced into the severe accident codes such as MAAP and SAMPSON, and SFP accident analyses were conducted. Analyses using Computational Fluid Dynamics (CFD) code were conducted as well for the comparison with SA code analyses and investigation of detail in the SFP accident. In addition, three-dimensional criticality analysis method was developed as well, and safer loading pattern of spent fuels in pool was investigated.
Ino, Kohei*; Hernsdorf, A. W.*; Konno, Yuta*; Kozuka, Mariko*; Yanagawa, Katsunori*; Kato, Shingo*; Sunamura, Michinari*; Hirota, Akinari*; Togo, Yoko*; Ito, Kazumasa*; et al.
ISME Journal, 12(1), p.31 - 47, 2018/01
Times Cited Count：49 Percentile：91.33(Ecology)In this study, we found the dominance ofanaerobic methane-oxidizing archaea in groundwater enriched in sulfate and methane from a 300-m deep underground borehole in granitic rock.
Uchiyama, Yusuke*; Azuma, Kohei*; Odani, Sachika*; Iwasaki, Toshiki*; Tsumune, Daisuke*; Kamidaira, Yuki; Shimizu, Yasuyuki*; Onda, Yuichi*
Doboku Gakkai Rombunshu, B2 (Kaigan Kogaku) (Internet), 73(2), p.I_685 - I_690, 2017/10
no abstracts in English
Kawasaki, Masatsugu; Nakajima, Junya; Yoshida, Keisuke; Kato, Saori; Nishino, Sho; Nozaki, Teo; Nakagawa, Masahiro; Tsunoda, Junichi; Sugaya, Yuki; Hasegawa, Rie; et al.
JAEA-Data/Code 2017-004, 57 Pages, 2017/03
JAEA-Data-Code-2017-004.pdf:2.34MB
In emergency situation of nuclear facilities, we need to estimate the radiation dose due to radiation and radioactivity to grasp the influence range of the accident in the early stage. Therefore, we prepare the case studies of dose assessment for public exposure dose and personal exposure dose and contribute them to emergency procedures. This document covers about accidents of nuclear facilities in Nuclear Science Research Institute and past accident of nuclear power plant, and it can be used for inheritance of techniques of emergency dose assessment.
Nemoto, Yoshiyuki; Kaji, Yoshiyuki; Ogawa, Chihiro; Nakashima, Kazuo*; Tojo, Masayuki*; Goto, Daisuke*
Fushoku Boshoku Kyokai Dai-62-Kai Zairyo To Kankyo Toronkai Koenshu (CD-ROM), p.23 - 24, 2015/11
In order to clarify the air oxidation behavior of the cladding at high temperatures for study on improvement of safety for accident conditions in spent fuel pool, the oxidation tests for both small specimens under constant temperature conditions and long specimens under loss of coolant simulated temperature conditions were carried out, and the knowledge for influence of both temperature gradient and preoxide film on oxidation behavior of the cladding were obtained in this study.
as the origin of volume collapseYu, R.*; Hojo, Hajime*; Watanuki, Tetsu; Mizumaki, Masaichiro*; Mizokawa, Takashi*; Oka, Kengo*; Kim, H.*; Machida, Akihiko; Sakaki, Koji*; Nakamura, Yumiko*; et al.
Journal of the American Chemical Society, 137(39), p.12719 - 12728, 2015/10
Times Cited Count：34 Percentile：70.17(Chemistry, Multidisciplinary)no abstracts in English
Yamada, Katsunori; Fujii, Katsutoshi; Kanda, Hiroshi; Higashi, Daisuke; Kobayashi, Toshiaki; Nakagawa, Masahiro; Fukami, Tomoyo; Yoshida, Keisuke; Ueno, Yumi; Nakajima, Junya; et al.
JAEA-Review 2013-033, 51 Pages, 2013/12
JAEA-Review-2013-033.pdf:2.73MB
After the accident at Fukushima Dai-ichi Nuclear Power Plant, various numerical criteria relevant to radiation protection were defined. We surveyed these criteria through internet. As a result of survey, the following 13 items were identified: (1) criteria for taking stable iodine tablets, (2) criteria for the screening of surface contamination, (3) evacuation area, sheltering area, etc., (4) activity concentrations in food, drinking water, etc., (5) dose limit for radiation workers engaged in emergency work, (6) guideline levels of radioactive substances in bathing areas, (7) criteria for use of school buildings and schoolyards, (8) restriction on planting rice, (9) acceptable activity concentrations in feedstuff, (10) acceptable activity concentrations in compost, (11) criteria for export containers and ships, (12) criteria for contaminated waste, (13) standards for radiation workers engaged in decontamination work. In this report, the basis of and issues on these criteria are summarized.
Shimada, Kenya*; Namatame, Hirofumi*; Taniguchi, Masaki*; Higashiguchi, Mitsuharu*; Fujimori, Shinichi; Saito, Yuji; Fujimori, Atsushi; Kim, M. S.*; Hirata, Daisuke*; Takabatake, Toshiro*
Physica B; Condensed Matter, 378-380, p.791 - 792, 2006/05
Times Cited Count：4 Percentile：22.76(Physics, Condensed Matter)The Ce 4f-derived states in CeRhX (X=Sn and In) were directly examined by means of high-resolution 3d-4f resonance photoemission spectroscopy. Compared with the Kondo metal CePtSn, which has a low Kondo temperature, CeRhX has a strong Ce 4f
weight near the Fermi level (
) and has a weak Ce 4f
peak, indicating a strong valence fluctuation. The Ce 4f spectral features indicate that the c-f hybridization strength in CeRhSn is weaker than that in CeRhIn.
-ray monitoringOkura, Takehisa; Oishi, Tetsuya; Miyauchi, Hideaki; Yoshitomi, Hiroshi; Tachibana, Haruo; Higashi, Daisuke; Suzuki, Akifumi*; Kobayashi, Ikuo*
no journal, ,
no abstracts in English
Higashi, Daisuke; Kawarai, Kunio; Yasu, Katsuji; Kinase, Susumu; Hiraga, Hayato
no journal, ,
no abstracts in English
Sr
CrO
Yu, R.*; Oka, Kengo*; Hojo, Hajime*; Azuma, Masaki*; Mizumaki, Masaichiro*; Agui, Akane; Inaguma, Yoshiyuki*; Mori, Daisuke*
no journal, ,
no abstracts in English
SrCrOYu, R.*; Oka, Kengo*; Hojo, Hajime*; Mizumaki, Masaichiro*; Agui, Akane; Mori, Daisuke*; Inaguma, Yoshiyuki*; Azuma, Masaki*
no journal, ,
no abstracts in English
Terada, Takaya; Kitsunai, Daisuke; Nishimura, Akihiko; Ito, Fuyumi*
no journal, ,
Nemoto, Yoshiyuki; Kaji, Yoshiyuki; Nakashima, Kazuo*; Tojo, Masayuki*; Goto, Daisuke*
no journal, ,
For the upgrading of the severe accident code aiming to analyze the coolant loss accident in spent fuel pool (SFP), it is required to model the air oxidation behavior of the cladding at high temperature. Authors proceeded air oxidation tests using small samples and long samples. For the long samples, temperature distribution simulating the SFP accident condition was given. The results were evaluated for the construction and validation of the air oxidation model. The results of the experiments and the outline of the program will be presented as well.
Kaji, Yoshiyuki; Nemoto, Yoshiyuki; Takase, Kazuyuki; Tojo, Masayuki*; Goto, Daisuke*; Iwata, Yutaka*; Otake, Yukihiko*; Nishimura, Satoshi*; Suzuki, Hiroaki*
no journal, ,
We will make quantitatively clear the phenomenon of fuel air oxidation mechanism, fuel failure mechanism after loss of coolant and criticality risks during and after sever accidents of Spent Fuel Pool(SFP) and clarify the quantitative effects of enhancements of SFP safety such as Spray and fuel loading patterns. We will report the whole plan in this presentation.
Kobayashi, Kensuke*; Goto, Daisuke*; Tojo, Masayuki*; Ikehara, Tadashi*; Kaji, Yoshiyuki; Nemoto, Yoshiyuki
no journal, ,
We evaluate fuel temperature based on the steady state heat transfer analysis with considering accurate fuel history and storage conditions.
Nemoto, Yoshiyuki; Ogawa, Chihiro; Kaji, Yoshiyuki; Nakashima, Kazuo*; Tojo, Masayuki*; Goto, Daisuke*
no journal, ,
To improve the severe accident codes for the analysis of spent fuel pool (SFP) accident with water level decrease, it is necessary to model the air oxidation behavior of the cladding based on experimental data. For the air oxidation modeling, it is necessary to understand the influence of temperature distribution along axial direction of the cladding in SFP accident condition. In addition, it is important to evaluate the influence of oxide film formed on surface of cladding during operation in nuclear power plant. In this study, bare specimens and pre-oxidized specimens of Japanese zircalloy-4 were investigated. Longer specimens of cladding were tested in air with temperature distribution along the axial direction of the cladding simulating the SFP accident condition. Shorter specimens were adopted for tests in thermogravimetry to obtain basic data. Experimental data were compared and the authors discussed on influence of the temperature distribution and oxide film for the air oxidation behavior.
