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Aono, Ryuji; Goto, Katsunori*; Kinase, Akari; Sato, Yoshiyuki; Haraga, Tomoko; Iseda, Hirokatsu
JAEA-Data/Code 2025-006, 24 Pages, 2025/07
Radioactive wastes generated from nuclear research facilities in Japan Atomic Energy Agency are planned to be buried in the near surface disposal field as trench and pit. Therefore, it is required to establish the method to evaluate the radioactivity concentrations of radioactive wastes until the beginning of disposal. In order to contribute to this work, we collected and analyzed the samples stored at the waste storage facility L. In this report, we summarized the radioactivity concentrations of 12 radionuclides (H,
C,
Co,
Sr,
Nb,
Cs,
Eu,
Eu,
Pu,
Pu,
Pu,
Am) which were obtained from radiochemical analysis of the samples in fiscal year 2020.
Kokubun, Yuji; Hosomi, Kenji; Seya, Natsumi; Nagaoka, Mika; Inoue, Kazumi; Koike, Yuko; Hasegawa, Ryo; Kubota, Tomohiro; Hirao, Moe; Iizawa, Shogo; et al.
JAEA-Review 2024-053, 116 Pages, 2025/03
Based on the regulations (the safety regulation of Tokai Reprocessing Plant, the safety regulation of nuclear fuel material usage facilities, the radiation safety rule, the regulation about prevention from radiation hazards due to radioisotopes, which are related with the nuclear regulatory acts, the local agreement concerning with safety and environment conservation around nuclear facilities, the water pollution prevention act, and by law of Ibaraki Prefecture), the effluent control of liquid waste discharged from the Nuclear Fuel Cycle Engineering Laboratories of Japan Atomic Energy Agency has been performed. This report describes the effluent control results of the liquid waste in the fiscal year 2023. In this period, the concentrations and the quantities of the radioactivity in liquid waste discharged from the reprocessing plant, the plutonium fuel fabrication facilities, and the other nuclear fuel material usage facilities were much lower than the limits authorized by the above regulations.
Song, Y.*; Xu, S.*; Sato, Shunsuke*; Lee, I.*; Xu, X.*; Omori, Toshihiro*; Nagasako, Makoto*; Kawasaki, Takuro; Kiyanagi, Ryoji; Harjo, S.; et al.
Nature, 638, p.965 - 971, 2025/02
Times Cited Count:5 Percentile:94.96(Multidisciplinary Sciences)Sato, Takuto; Goger, B.*; Nakayama, Hiromasa
SOLA (Scientific Online Letters on the Atmosphere) (Internet), 21, p.17 - 23, 2025/01
Times Cited Count:0 Percentile:0.00(Meteorology & Atmospheric Sciences)In this study, we conducted large-eddy simulations of turbulent flows and plume dispersion over idealized two-dimensional double steep hills. In the simulations, we investigated the distribution patterns of the mean plume concentrations, considering various distances between the hills and emission sources. Our objective was to provide information on the area of influence of local hilly terrains on plume dispersion from the viewpoint of accuracy, i.e., determining if the conventional Gaussian plume model can accurately predict plume concentrations. The result showed that the clockwise circulation was dominant in the area between the windward and leeward hills (valley) when the valley width was less than 10 times the hill height (). This circulation makes the flow close to the stack remain in the valley, resulting in the higher concentrations in the valley than in wider-valley (
10
valley) cases. The effect of the leeward hill on the flow field was negligible when the valley width was greater than 10
. In the area beyond 20
from the crest of the windward hill, estimated plume spreads for all cases were similar, indicating that the area of influence of the hills was approximately 20
.
Miura, Taito*; Miyamoto, Shintoro*; Maruyama, Ippei*; Aili, A.*; Sato, Takumi; Nagae, Yuji; Igarashi, Go*
Case Studies in Construction Materials, 21, p.e03571_1 - e03571_14, 2024/12
Times Cited Count:0 Percentile:0.00(Construction & Building Technology)Sato, Hinata; Mori, Amami; Kuno, Sorato; Horigome, Kazushi; Goto, Yuichi; Yamamoto, Masahiko; Taguchi, Shigeo
JAEA-Technology 2024-011, 56 Pages, 2024/10
Flush-out, which recovers remaining nuclear materials in the process and transfer it to a highly radioactive liquid waste storage tank, has been performed at main plant of Tokai Reprocessing Plant. The flush-out has been composed from three steps: first step is to remove of spent fuel sheared powder, second step is to collect plutonium solution stored in the process, and third step is to convert uranium solution into uranium trioxide powder. The first step of flush-out activity has been completed in 2022. Second and third steps of flush-out have been completed from March 2023 to February 2024. Process control analysis has been performed for operation of the facility, and material accountancy analysis has been performed to control the accountancy of nuclear materials. In addition, related analytical work such as pretreatment for transporting inspection samples for safeguards analysis laboratories in IAEA has been also performed. This report describes results of analytical work performed in collections of plutonium and uranium solutions in second and third steps of the flush-out, including calibration of analytical equipment, waste generation, and education and training of analytical operator.
Kinase, Akari; Goto, Katsunori*; Aono, Ryuji; Konda, Miki; Sato, Yoshiyuki; Haraga, Tomoko; Ishimori, Kenichiro; Kameo, Yutaka
JAEA-Data/Code 2024-004, 60 Pages, 2024/07
Radioactive wastes generated from nuclear research facilities in Japan Atomic Energy Agency are planning to be buried in the near surface disposal field as trench and pit. Therefore, it is required to establish the method to evaluate the radioactivity concentrations of radioactive wastes until the beginning of disposal. In order to contribute to this work, we collected and analyzed the samples generated from JRR-2 and JRR-3 and stored at the waste storage facility L. In this report, we summarized the radioactivity concentrations of 20 radionuclides (H,
C,
Cl,
Co,
Ni,
Sr,
Nb,
Tc,
Ag,
I,
Cs,
Eu,
Eu,
U,
U,
Pu,
Pu,
Pu,
Am,
Cm) which were obtained from radiochemical analysis of the samples in fiscal year 2022.
Lan, Z.*; Arikawa, Yasunobu*; Mirfayzi, S. R.*; Morace, A.*; Hayakawa, Takehito*; Sato, Hirotaka*; Kamiyama, Takashi*; Wei, T.*; Tatsumi, Yuta*; Koizumi, Mitsuo; et al.
Nature Communications (Internet), 15, p.5365_1 - 5365_7, 2024/07
Times Cited Count:5 Percentile:75.95(Multidisciplinary Sciences)Ouchi, Kazuki; Haraga, Tomoko; Hirose, Kazuki*; Kurosawa, Yuika*; Sato, Yoshiyuki; Shibukawa, Masami*; Saito, Shingo*
Analytica Chimica Acta, 1298, p.342399_1 - 342399_7, 2024/04
Times Cited Count:1 Percentile:34.56(Chemistry, Analytical)Given that conventional methods of high-dose sample analysis pose substantial exposure risks and generate large amounts of secondary radioactive waste, faster procedures allowing for decreased radiation emission are highly desirable. To address this need, we developed a Sr
quantitation technique that is based on liquid scintillation counting-coupled capillary transient isotachophoresis (ctITP) with two-point detection and relies on the rapid concentration, separation, and fractionation of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)-complexed
Sr
in a single run. This method, which allows for the handling of high-dose radioactive specimens at the microliter level and is substantially faster than conventional ion-exchange protocols, was used to selectively quantify
Sr
in real high-dose waste. The successful concentration-separation in ctITP was ascribed to the inertness of the Sr-DOTA complex to dissociation.
Katsumata, Tetsuhiro*; Suzuki, Ryo*; Sato, Naoto*; Oda, Ryoya*; Motoyama, Shingo*; Suzuki, Shumpei*; Nakashima, Mamoru*; Inaguma, Yoshiyuki*; Mori, Daisuke*; Aimi, Akihisa*; et al.
Chemistry of Materials, 36(8), p.3697 - 3704, 2024/04
Times Cited Count:1 Percentile:30.18(Chemistry, Physical)A perovskite-type oxynitride BaFeOF was prepared by high-pressure synthesis. Since the SHG signal was observed in the obtained material, suggesting the existence of spontaneous polarization, the mechanism of polarization was investigated by synchrotron high-energy X-ray diffraction. The obtained pair distribution functions were fitted, and a local polarization mechanism with different orientations was found. Since BaFeO
F is also a magnetic material, a magnetic domain and a ferroelectric domain are considered to coexist.
Katabuchi, Tatsuya*; Sato, Yaoki*; Takebe, Karin*; Igashira, Masayuki*; Umezawa, Seigo*; Fujioka, Ryo*; Saito, Tatsuhiro*; Iwamoto, Nobuyuki
Journal of Nuclear Science and Technology, 61(2), p.224 - 229, 2024/02
Times Cited Count:0 Percentile:0.00(Nuclear Science & Technology)Braby, L. A.*; Conte, V.*; Dingfelder, M.*; Goodhead, D. T.*; Pinsky, L. S.*; Rosenfeld, A. B.*; Sato, Tatsuhiko; Waker, A. J.*; Guatelli, S.*; Magrin, G.*; et al.
Journal of ICRU, 23(1), p.1 - 168, 2023/12
This report provides a comprehensive description of the basic concepts and theories, computational and experimental procedures, and applications of microdosimetry.
Sato, Tetsuya*; Oue, Daigo*; Matsuo, Mamoru; Kato, Takeo*
Physical Review B, 108(9), p.094428_1 - 094428_10, 2023/09
Times Cited Count:0 Percentile:0.00(Materials Science, Multidisciplinary)Aoya, Juri; Mori, Amami; Sato, Hinata; Kono, Soma; Morokado, Shiori; Horigome, Kazushi; Goto, Yuichi; Yamamoto, Masahiko; Taguchi, Shigeo
JAEA-Technology 2023-008, 34 Pages, 2023/06
Flush-out, by which nuclear materials in the Tokai Reprocessing Plant process are recovered, has been started in June 2022 as the first step of decommissioning. Flush-out consists of removal of spent fuel sheared powder, plutonium solution, uranium solution, and the other nuclear materials. Removal of spent fuel sheared powder has been completed in September 2022. During removal of spent fuel sheared powder, uranium concentration, plutonium concentration, acid concentration, radioactivity concentration, and solution density have been analyzed for process control. For nuclear material accountancy, uranium concentration, plutonium concentration, isotope ratio, and solution density have been analyzed. Analysis work including sample pretreatment before transportation to IAEA analytical facility for safeguards, and the other operations related to Flush-out such as calibration of analytical instruments, education, and training of operators are reported.
Sato, Tetsuya*; Kato, Takeo*; Oue, Daigo*; Matsuo, Mamoru
Physical Review B, 107(18), p.L180406_1 - L180406_6, 2023/05
Times Cited Count:2 Percentile:25.54(Materials Science, Multidisciplinary)Saito, Shingo*; Haraga, Tomoko; Marumo, Kazuki*; Sato, Yoshiyuki; Nakano, Yuta*; Tasaki-Handa, Yuiko*; Shibukawa, Masami*
Bulletin of the Chemical Society of Japan, 96(3), p.223 - 225, 2023/03
Times Cited Count:3 Percentile:32.03(Chemistry, Multidisciplinary)Highly efficient and effective separation between americium (Am) and curium ion (Cm
) was achieved by two simple electrophoresis-based techniques. Am
and Cm
ions were complexed with fluorophore-modified acyclic hexadentate and octadentate polyaminocarboxylates and then were electrophoretically separated and fluorescently detected in free solution with ternary complexation or in gel medium.
Iwamoto, Osamu; Iwamoto, Nobuyuki; Kunieda, Satoshi; Minato, Futoshi; Nakayama, Shinsuke; Abe, Yutaka*; Tsubakihara, Kosuke*; Okumura, Shin*; Ishizuka, Chikako*; Yoshida, Tadashi*; et al.
Journal of Nuclear Science and Technology, 60(1), p.1 - 60, 2023/01
Times Cited Count:213 Percentile:99.99(Nuclear Science & Technology)Gogami, Toshiyuki*; Ebata, Kengo; Fujita, Manami; Harada, Takeshi; Hasegawa, Shoichi; Hosomi, Kenji; Ichikawa, Yudai; Imai, Kenichi*; Kim, S.; Nanamura, Takuya; et al.
EPJ Web of Conferences, 271, p.11002_1 - 11002_7, 2022/11
Ishii, Yui*; Yamamoto, Arisa*; Sato, Naoki*; Nambu, Yusuke*; Kawamura, Seiko; Murai, Naoki; Ohara, Koji*; Kawaguchi, Shogo*; Mori, Takao*; Mori, Shigeo*
Physical Review B, 106(13), p.134111_1 - 134111_7, 2022/10
Times Cited Count:0 Percentile:0.00(Materials Science, Multidisciplinary)Takeuchi, Yusuke*; Tojo, Junji*; Yamanaka, T.*; Nakazawa, Yuga*; Iinuma, Hiromi*; Kondo, Yasuhiro; Kitamura, Ryo; Morishita, Takatoshi; Cicek, E.*; Ego, Hiroyasu*; et al.
Proceedings of 31st International Linear Accelerator Conference (LINAC 2022) (Internet), p.562 - 564, 2022/10
A muon linac is under development for future muon g-2/EDM experiments at J-PARC. The linac provides a 212 MeV muon beam to an MRI-type compact storage ring. After the initial acceleration using the electrostatic field created by mesh and cylindrical electrodes, the muons are accelerated using four types of radio-frequency accelerators. To validate the linac design as a whole, end-to-end simulations were performed using General Particle Tracer. In addition, error studies were performed to investigate the effects on beam and spin dynamics of various errors in the accelerator components and input beam distribution. This paper describes the results of the end-to-end simulations and error studies.