Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Initialising ...
Hatakeyama, Yuichi; Hirai, Koki; Ikegami, Yuta*; Sano, Naruto; Tomita, Takeshi; Usami, Koji; Tagami, Susumu
JAEA-Technology 2024-020, 33 Pages, 2025/03
The Waste Safety Testing Facility (WASTEF) is a facility that began operation in December 1982 with the aim of conducting safety testing research on the long-term storage and subsequent geological disposal of high-level radioactive waste generated by the reprocessing of spent fuel. This facility is composed of five concrete cells, one lead cell, six glove boxes, and seven hoods, and is a large-scale facility capable of using nuclear fuel materials including uranium and plutonium, as well as radioisotopes such as neptunium and americium. The facility is equipped with an automatic fire alarm system for the entire building in accordance with the Fire Service Act and regulations on technical standards for facilities used. This is an important aspect of safety management, and it is required that the equipment be sufficiently sound and reliable. However, after more than 30 years of use since its installation, the fire receiving panel, one of the components of the automatic fire alarm system, has deteriorated significantly. Furthermore, many of the parts used have been discontinued and are no longer available, making it difficult to procure them, making it difficult to maintain the equipment's performance. Therefore, in order to ensure the safe and stable operation of WASTEF, the fire receiving panel was updated. This report summarizes the update of the fire receiving panel among the automatic fire alarm equipment that was implemented in FY2022.
Miyazaki, Yasunori; Sano, Yuichi; Ishigami, Ryoya*
EPJ Web of Conferences, 317, p.01006_1 - 01006_7, 2025/01
The gamma-ray and He ion beam (which is simulated for alpha-ray from
Am, for example) were irradiated on the TEHDGA adsorbent to evaluate the hydrogen gas production, leaching amount of organics in the immersed 3 M HNO
solution, thermal characteristics and speciation of the degradation products. These were combined to assess the safety of the 1st run of the MA separation process from the raffinate at a dose rate of 1 kGy/h.
Oshima, Masumi*; Goto, Jun*; Hayakawa, Takehito*; Shinohara, Hirofumi*; Suzuki, Katsuyuki*; Sano, Yuichi*; Asai, Masato; Haraga, Tomoko
Journal of Nuclear Science and Technology, 61(7), p.871 - 882, 2024/07
Times Cited Count:1 Percentile:30.19(Nuclear Science & Technology)Previously we reported a simple algorithmic method of spectral determination method (SDM), which is based on the first principle that a -ray spectrum obtained for a sample is a linear superposition of individual spectra of the radioactive nuclides included in the sample and demonstrated that the method is valid for
-ray determination. Here we apply it to the spectra obtained by liquid scintillation counter (LSC). In LSC measurements quenching is generally observed and we at first developed its correction method to standard spectra. The SDM code reported in the previous investigation is used to analyze the LSC spectra. Based on the analyses done by using the measured spectra, we concluded that the SDM method is valid in the LSC spectra similarly to the
-ray spectra studied in the previous investigation.
Mori, Yuichiro*; Kagi, Hiroyuki*; Aoki, Katsutoshi*; Takano, Masahiro*; Kakizawa, Sho*; Sano, Asami; Funakoshi, Kenichi*
Earth and Planetary Science Letters, 634, p.118673_1 - 118673_8, 2024/05
Times Cited Count:1 Percentile:58.96(Geochemistry & Geophysics)To investigate silicon effects on the hydrogen-induced volume expansion of iron, neutron diffraction and X-ray diffraction experiments were conducted to examine hcp-FeSi
under high pressures and high temperatures. Neutron diffraction experiments were performed on the deuterated hcp-Fe
Si
at 13.5 GPa and 900 K, and at 12.1 GPa and 300 K. By combining the P-V-T equation of state of hcp-Fe
Si
, present results indicate that the hydrogen-induced volume expansion of hcp-Fe
Si
is 10% greater than that of pure hcp iron. Using the obtained values, we estimated the hydrogen content that would reproduce the density deficit in the inner core, which was 50% less than that without the effect of silicon. Possible hydrogen content,
, in the inner core and the outer core was calculated to be 0.07 and 0.12-0.15, respectively, when reproducing the density deficit of the inner core with hcp-Fe
Si
Hx.
Hasegawa, Kenta; Goto, Ichiro*; Miyazaki, Yasunori; Ambai, Hiromu; Watanabe, So; Watanabe, Masayuki; Sano, Yuichi; Takeuchi, Masayuki
Mechanical Engineering Journal (Internet), 11(2), p.23-00407_1 - 23-00407_8, 2024/04
Watanabe, So; Takahatake, Yoko; Hasegawa, Kenta; Goto, Ichiro*; Miyazaki, Yasunori; Watanabe, Masayuki; Sano, Yuichi; Takeuchi, Masayuki
Mechanical Engineering Journal (Internet), 11(2), p.23-00461_1 - 23-00461_10, 2024/04
Sano, Naruto; Yamashita, Naoki; Watanabe, Masaya; Tsukada, Manabu*; Hoshino, Kazutoyo*; Hirai, Koki; Ikegami, Yuta*; Tashiro, Shinsuke; Yoshida, Ryoichiro; Hatakeyama, Yuichi; et al.
JAEA-Technology 2023-029, 36 Pages, 2024/03
At the Waste Safety Testing Facility (WASTEF), the gamma ray irradiation device "Gamma Cell 220" was relocated from the 4th Research Building of the Nuclear Science Research Institute in FY2019, and the use of gamma ray irradiation has begun. Initially, Fuel Cycle Safety Research Group, Fuel Cycle Safety Research Division, Nuclear Safety Research Center, Sector of Nuclear Safety Research and Emergency Preparedness, the owner of this device, conducted the tests as the main user, but since 2022, other users, including those outside the organization, have started using it. The gamma ray irradiation device "Gamma Cell 220" is manufactured by Nordion International Inc. in Canada. Since it was purchased in 1989, the built-in Co radiation source has been updated once, and safety research related to nuclear fuel cycles, etc. It is still used for this purpose to this day. This report summarizes the equipment overview of the gamma ray irradiation device "Gamma Cell 220", its permits and licenses at WASTEF, usage status, maintenance and inspection, and future prospects.
Miyagawa, Akihisa*; Hayashi, Naoki*; Iwamoto, Hibiki*; Arai, Tsuyoshi*; Nagatomo, Shigenori*; Miyazaki, Yasunori; Hasegawa, Kenta; Sano, Yuichi; Nakatani, Kiyoharu*
Analytical Sciences, 40(2), p.347 - 352, 2024/02
Times Cited Count:1 Percentile:14.27(Chemistry, Analytical)The Eu(III) distribution mechanism in single extractant-impregnated polymer-layered silica particle in a complex solution containing multiple lanthanide ions was investigated using fluorescence microspectroscopy. The rate-determining step was the reaction of Eu(III) with the two extractant molecules. The obtained mechanism and rate constants agreed with those of the single-ion distribution system, in which Eu(III) was distributed to the particles in the Eu(III) solution.
Takano, Masahiro*; Kagi, Hiroyuki*; Mori, Yuichiro*; Aoki, Katsutoshi*; Kakizawa, Sho*; Sano, Asami; Iizuka-Oku, Riko*; Tsuchiya, Taku*
Journal of Mineralogical and Petrological Sciences (Internet), 119(1), p.240122_1 - 240122_9, 2024/00
Times Cited Count:0 Percentile:0.00(Mineralogy)Hydrogenation of iron sulfide (FeS) under high-pressure and high-temperature conditions has attracted attention because hydrogen and sulfur are promising candidates as light elements in the cores of the Earth and other terrestrial planets. In earlier reports describing the hydrogenation of FeS, the chemical compositions of starting materials were not fully clarified. This study reports in-situ neutron and X-ray diffraction measurements under high-pressure and high-temperature conditions of an Fe-S-H system using a stochiometric Fe1.000S (troilite) as a starting material. The occupancies determined were significantly lower than those reported from earlier studies, indicating that the hydrogenation of FeS can be affected strongly by the stoichiometry of iron sulfide.
Miyagawa, Akihisa*; Takahashi, Takumi*; Kuzure, Yoshiaki*; Iwamoto, Hibiki*; Arai, Tsuyoshi*; Nagatomo, Shigenori*; Watanabe, So; Sano, Yuichi; Nakatani, Kiyoharu*
Analytical Sciences, 39(11), p.1929 - 1936, 2023/11
Times Cited Count:1 Percentile:14.27(Chemistry, Analytical)In this study, we revealed the Eu(III) distribution in a single diglycolamide-derivative extractant (TODGA)-impregnated polymer-coated silica particle. The reaction of Eu(III) with two TODGA molecules in the polymer layer was the rate-limiting process, as evidenced by the absence of any correlation between the rate constants (k and k
) and concentrations of Eu(III) and HNO
.
Miyagawa, Akihisa*; Hayashi, Naoki*; Iwamoto, Hibiki*; Arai, Tsuyoshi*; Nagatomo, Shigenori*; Miyazaki, Yasunori; Hasegawa, Kenta; Sano, Yuichi; Nakatani, Kiyoharu*
Bulletin of the Chemical Society of Japan, 96(9), p.1019 - 1025, 2023/09
Times Cited Count:3 Percentile:38.33(Chemistry, Multidisciplinary)In the present study, we have elucidated the mass transfer mechanism of Eu(III) and Sm(III) in the solution with these ions in single nitrilotriacetamide (NTA) extractant-impregnated polymer-coated silica particle. The rate-limiting process of mass transfer was the reaction process of ions with NTA molecules, in which the NO ions were not involved, which was consistent with that obtained in single ion distribution system.
Sano, Tomokazu*; Matsuda, Tomoki*; Hirose, Akio*; Terai, Tomoyuki*; Kakeshita, Tomoyuki*; Inubushi, Yuichi*; Sato, Takahiro*; Yabashi, Makina*; Shobu, Takahisa; 22 of others*
Scientific Reports (Internet), 13, p.13796_1 - 13796_10, 2023/08
Times Cited Count:1 Percentile:0.00(Multidisciplinary Sciences)Miyagawa, Akihisa*; Hayashi, Naoki*; Kuzure, Yoshiaki*; Takahashi, Takumi*; Iwamoto, Hibiki*; Arai, Tsuyoshi*; Nagatomo, Shigenori*; Miyazaki, Yasunori; Hasegawa, Kenta; Sano, Yuichi; et al.
Bulletin of the Chemical Society of Japan, 96(7), p.671 - 676, 2023/07
Times Cited Count:6 Percentile:62.64(Chemistry, Multidisciplinary)We investigated the distribution mechanism of Eu(III) in a single polymer-coated silica particle including nitrilotriacetamide (NTA) extractants known as HONTA and TOD2EHNTA. The present study provides a valuable approach for the evaluation and enhancement of the functionality of "single extractant-impregnated polymer-coated silica particle".
Hasegawa, Kenta; Goto, Ichiro*; Miyazaki, Yasunori; Ambai, Hiromu; Watanabe, So; Watanabe, Masayuki; Sano, Yuichi; Takeuchi, Masayuki
Proceedings of 30th International Conference on Nuclear Engineering (ICONE30) (Internet), 5 Pages, 2023/05
Watanabe, So; Takahatake, Yoko; Hasegawa, Kenta; Goto, Ichiro*; Miyazaki, Yasunori; Watanabe, Masayuki; Sano, Yuichi; Takeuchi, Masayuki
Proceedings of 30th International Conference on Nuclear Engineering (ICONE30) (Internet), 6 Pages, 2023/05
Akuzawa, Tadashi*; Kim, S.-Y.*; Kubota, Masahiko*; Wu, H.*; Watanabe, So; Sano, Yuichi; Takeuchi, Masayuki; Arai, Tsuyoshi*
Journal of Radioanalytical and Nuclear Chemistry, 331(12), p.5851 - 5858, 2022/12
Times Cited Count:5 Percentile:64.62(Chemistry, Analytical)Miyagawa, Akihisa*; Kusano, Yuka*; Nagatomo, Shigenori*; Sano, Yuichi; Nakatani, Kiyoharu*
Analytical Sciences, 38(7), p.955 - 961, 2022/07
Times Cited Count:1 Percentile:6.52(Chemistry, Analytical)In this study, we reveal an Eu(III) extraction mechanism at the interface between HNO and tributyl phosphate (TBP) solutions using fluorescence microspectroscopy. The mass transfer rate constant at the interface is obtained from the analysis of fluorescence intensity changes during the forward and backward extractions at various HNO
and TBP concentrations to investigate the reaction mechanism. This result indicates that one nitrate ion reacts with Eu(III) at the interface, whereas TBP molecules are not involved in the interfacial reaction, which is different from the results obtained using the NaNO
solution in our previous study. We demonstrate that the chemical species of Eu(III) complex with nitrate ion and TBP in the aqueous solution play an important role for the extraction mechanism.
Sano, Yuichi; Sakamoto, Atsushi; Miyazaki, Yasunori; Watanabe, So; Morita, Keisuke; Emori, Tatsuya; Ban, Yasutoshi; Arai, Tsuyoshi*; Nakatani, Kiyoharu*; Matsuura, Haruaki*; et al.
Proceedings of International Conference on Nuclear Fuel Cycle; Sustainable Energy Beyond the Pandemic (GLOBAL 2022) (Internet), 4 Pages, 2022/07
We developed a hybrid MA(III) recovery process combining MA(III)+Ln(III) co-recovery flowsheet by solvent extraction with TBP and MA(III)/Ln(III) separation flowsheet by simulated moving bed chromatography using HONTA impregnated adsorbents with large particle size porous silica support.
Ohshima, Hiroyuki; Morishita, Masaki*; Aizawa, Kosuke; Ando, Masanori; Ashida, Takashi; Chikazawa, Yoshitaka; Doda, Norihiro; Enuma, Yasuhiro; Ezure, Toshiki; Fukano, Yoshitaka; et al.
Sodium-cooled Fast Reactors; JSME Series in Thermal and Nuclear Power Generation, Vol.3, 631 Pages, 2022/07
This book is a collection of the past experience of design, construction, and operation of two reactors, the latest knowledge and technology for SFR designs, and the future prospects of SFR development in Japan. It is intended to provide the perspective and the relevant knowledge to enable readers to become more familiar with SFR technology.
Miyagawa, Akihisa*; Takeuchi, Masayuki; Arai, Tsuyoshi*; Watanabe, So; Sano, Yuichi; Nakatani, Kiyoharu*
Bulletin of the Chemical Society of Japan, 95(4), p.566 - 568, 2022/04
Times Cited Count:3 Percentile:23.15(Chemistry, Multidisciplinary)We demonstrate that pKa of extractant impregnated in a polymer phase varies with the cross-linking degree and the coexistence of other extractants, which induces a change in the hydrophobicity of the polymer phase. The results presented herein will be beneficial for the development of novel solid-extraction adsorbents.