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Iketani, Shotaro; Suzuki, Takeshi; Yokobori, Tomohiko; Sugawara, Satoshi; Yokota, Akira; Kikuchi, Genta; Muraguchi, Yoshinori; Kitahara, Masaru; Seya, Manato; Kurosawa, Tsuyoshi; et al.
JAEA-Technology 2025-001, 169 Pages, 2025/08
JAEA-Technology-2025-001.pdf:14.22MB
The radioactive waste treatment facilities at the Nuclear Science Research Institute includes the Radioactive Waste Treatment Facility No. 3, Waste Size Reduction and Storage Facility, and Waste Volume Reduction Facility. These three facilities come under the purview of the Act on the Regulation of Nuclear Source Material, Nuclear Fuel Material and Reactors, and are included under Class C of the act based on the seismic requirements specified in the Act. We assessed the seismic capacity of these three radioactive waste treatment facilities based on the current Building Standards Act, to verify whether they comply with the new regulatory requirements enforced by the Nuclear Regulation Authority (NRA) in the aftermath of the 2011 nuclear accident at the Fukushima Daiichi Nuclear Power Station operated by the Tokyo Electric Power Company. We found that the allowable stress of a few structural members used in the construction of the facilities did not meet the regulatory requirements. After studying the approval granted by the NRA for the construction plans, including the design and construction methods (design and construction plans) of the three facilities on March 5, 2021, we made aseismic reinforcement at these facilities between 2021 and 2022. This report presents an overview of the seismic design of these facilities and an outline of the aseismic reinforcement conducted, management system existing, safety measures adopted, and the preoperational inspections conducted at these facilities.
Kawai, Keito*; Nemoto, Yoshiyuki; Fujimura, Yuki; Kondo, Keietsu; Abe, Yosuke; Mohamad, A. B.; Pham, V. H.; Ishikawa, Norito; Ishijima, Yasuhiro; Ioka, Ikuo; et al.
Nihon Genshiryoku Gakkai Wabun Rombunshi (Internet), 24(3), p.82 - 98, 2025/08
An accident tolerant fuel (ATF) cladding, which is more resistant to accidents than the conventional Zircaloy cladding, is under development. One of these claddings is a chromium (Cr)-coated cladding with an outer surface coated with Cr, which is expected to improve the resistance to high-temperature steam oxidation. In this study, electrochemical plating was applied to coat a Cr layer on the cladding outer surface, and its properties under accidental conditions were evaluated. In a loss-of-coolant accident (LOCA), the cladding will burst and both the outer and inner surfaces of the cladding will be oxidized. Thus, as-received Zircaloy-4 and Cr-coated claddings were tested for oxidation in high-temperature steam to investigate differences in oxidation behavior, hydrogen absorption behavior, and mechanical properties after oxidation. Oxidation tests were conducted using a thermobalance. The amount of oxidation of coated samples decreased by half compared with that of uncoated samples, indicating that the coating was effective in inhibiting oxidation. However, the hydrogen absorption of coated samples was found to be higher than that of uncoated samples. In this paper, we discuss the mechanism behind this difference in hydrogen absorption and its effect on mechanical properties.
Yamamoto, Keisuke; Nakagawa, Takuya; Shimojo, Hiroto; Kijima, Jun; Miura, Daiya; Onose, Yoshihiko*; Namba, Koji*; Uchida, Hiroaki*; Sakamoto, Kazuhiko*; Ono, Chika*; et al.
JAEA-Technology 2024-019, 211 Pages, 2025/02
JAEA-Technology-2024-019.pdf:35.35MB
The uranium enrichment facilities at the Nuclear Fuel Cycle Engineering Laboratories of Japan Atomic Energy Agency (JAEA) were constructed sequentially to develop uranium enrichment technology with centrifugal separation method. The developed technologies were transferred to Japan Nuclear Fuel Limited until 2001. And the original purpose has been achieved. Wastewater Treatment Facility, one of the uranium enrichment facilities, was constructed in 1976 to treat radioactive liquid waste generated at the facilities, and it finished the role in 2008. In accordance with the Medium/Long-Term Management Plan of JAEA Facilities, interior equipment installed in this facility had been dismantled and removed since November 2021 to August 2023. This report summarizes the findings obtained through the work related to the contamination inspection methods cancellation the controlled area of Wastewater Treatment Facility from September 2023 to March 2024.
Nozaki, Yukio*; Sukegawa, Hiroaki*; Watanabe, Shinichi*; Yunoki, Seiji*; Horaguchi, Taisuke*; Nakayama, Hayato*; Yamanoi, Kazuto*; Wen, Z.*; He, C.*; Song, J.*; et al.
Science and Technology of Advanced Materials, 26(1), p.2428153_1 - 2428153_39, 2025/02
Times Cited Count：0 Percentile：0.00(Materials Science, Multidisciplinary)Imatomi, Daisuke*; Ishikawa, Ryosuke*; Nakata, Akira*; Ito, Tatsuya; Han, K.*; Nagasako, Makoto*; Xu, X.*; Omori, Toshihiro*; Kainuma, Ryosuke*
Journal of Phase Equilibria and Diffusion, 45(1), p.3 - 17, 2024/02
Times Cited Count：4 Percentile：24.83(Chemistry, Physical)Phase equilibria in the Mn-Zn binary system were experimentally determined by chemical composition examination, crystal structure determination, and thermal analysis. Major changes were detected for the 
, 
, and 
phases. The -B2 single-phase region could not be confirmed in the studied system because a disordered body-centered cubic structure, which is identical to the Mn phase, was confirmed in a quenched sample from the previously proposed region of phase. The phase has been controversial whether the phase is separated into , 
, and 
phases or not. By studying a diffusion couple and several alloy compositions, it was established that the , , and phases are not separate and comprise a single phase. Furthermore, the phase is not present in the Zn-rich region of the system because the corresponding invariant reactions were not detected via thermal analysis.
atoms (J-PARC E03, E07 and future)Yamamoto, Takeshi; Fujita, Manami; Gogami, Toshiyuki*; Harada, Takeshi*; Hayakawa, Shuhei*; Hosomi, Kenji; Ichikawa, Yudai; Ishikawa, Yuji*; Kamata, K.*; Kanauchi, H.*; et al.
EPJ Web of Conferences, 271, p.03001_1 - 03001_5, 2022/11
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.
Tanaka, Kosuke; Sato, Isamu*; Onishi, Takashi; Ishikawa, Takashi; Hirosawa, Takashi; Katsuyama, Kozo; Seino, Hiroshi; Ohno, Shuji; Hamada, Hirotsugu; Tokoro, Daishiro*; et al.
Journal of Nuclear Materials, 536, p.152119_1 - 152119_8, 2020/08
Times Cited Count：0 Percentile：0.00(Materials Science, Multidisciplinary)In order to obtain the release rate coefficients from fuels for fast reactors (FRs), heating tests and the subsequent analyses of the fission products (FPs) and actinides that are released were carried out using samples of uranium-plutonium mixed oxide (MOX) fuel pellets irradiated at the experimental fast reactor Joyo. Three heating tests targeting temperatures of 2773, 2973 and 3173 K were conducted using an FP release behavior test apparatus equipped with a high-frequency induction furnace and solid FP sampling systems consisting of a thermal gradient tube (TGT) and filters. Irradiated fuel pellets were placed into a tungsten crucible, then loaded into the induction furnace. The temperature was raised continuously at a heating rate of 10 K/s to the targeted temperature and maintained for 500 s in a flowing argon gas atmosphere. The FPs and actinides released from the MOX fuels and deposited in the TGT and filters were quantified by gamma-ray spectrometry and inductively coupled plasma mass spectrometry (ICP-MS) analysis. Based on the analysis, the release rates of radionuclides from MOX fuels for FR were obtained and compared with literature data for light water reactor (LWR) fuels. The release rate coefficients of FPs obtained in this study were found to be similar to or lower than the literature values for LWR fuels. It was also found that the release rate coefficient data for actinides were within the range of variation of literature values for LWR fuels.
O
Yoshioka, Satoru*; Tsuruta, Konosuke*; Yamamoto, Tomokazu*; Yasuda, Kazuhiro*; Matsumura, Sho*; Sugiyama, Takeharu*; Oba, Yojiro; Ishikawa, Norito; Kobayashi, Eiichi*; Okudaira, Koji*
Journal of the American Ceramic Society, 103(8), p.4654 - 4663, 2020/08
Times Cited Count：8 Percentile：28.27(Materials Science, Ceramics)X-ray absorption near edge structure (XANES) and small-angle X-ray scattering (SAXS) reveal the damaged structures in MgAlO spinel induced by swift heavy ions. SAXS indicates the formation of ion tracks with cylindrical shape with a diameter of 5 nm. XANES indicates the cationic disordering between tetrahedral and octahedral sites by the irradiation. Quantitative analysis of XANES also reveals that cations preferably occupy the octahedral sites at high fluence.
and 200 MeV Xe ion irradiationLi, R.*; Narumi, Kazumasa*; Chiba, Atsuya*; Hirano, Yu*; Tsuya, Daiju*; Yamamoto, Shunya*; Saito, Yuichi*; Okubo, Nariaki; Ishikawa, Norito; Pang, C.*; et al.
Nanotechnology, 31(26), p.265606_1 - 265606_9, 2020/06
Times Cited Count：8 Percentile：32.86(Nanoscience & Nanotechnology)We report the elongation of embedded Au nanoparticles (NPs) in three different matrices under irradiations of 4 MeV C ions and 200 MeV Xe ions. Large elongation of Au NPs was observed for crystalline indium tin oxide (ITO) under both 4 MeV C and 200 MeV Xe irradiation. The ITO layer preserved the crystallinity even after large elongation was induced. This is the first report of the elongation of metal NPs in a crystalline matrix.
CoFe
O
Komabuchi, Mai*; Urushihara, Daisuke*; Asaka, Toru*; Fukuda, Koichiro*; Ohara, Takashi; Munakata, Koji*; Ishikawa, Yoshihisa*
Journal of the Physical Society of Japan, 89(3), p.034601_1 - 034601_5, 2020/03
Times Cited Count：3 Percentile：15.46(Physics, Multidisciplinary)Kusumoto, Tamon*; Matsuya, Yusuke; Baba, Kentaro*; Ogawara, Ryo*; Akselrod, M. S.*; Harrison, J.*; Fomenko, V.*; Kai, Takeshi; Ishikawa, Masayori*; Hasegawa, Sumitaka*; et al.
Radiation Measurements, 132, p.106256_1 - 106256_4, 2020/03
Times Cited Count：11 Percentile：64.34(Nuclear Science & Technology)Internal radiation therapy with Cu-64 concentrates energy deposition in tumor cells by virtue of released Auger electrons with low energy. In our previous study, we have attached the solutions at the surface of Fluorescent Nuclear Track Detector (FNTD) and succeeded in measuring the absorbed doses of Auger electrons registered in FNTD. However, because there are several types of radiation emitted from the source, i.e., beta rays, positron etc., the contribution degree of Auger electron to energy concentration remain uncertain. In this study, we quantitatively analyzed the spatial dose distribution in the FNTD based on Monte Carlo simulation with PHITS and GEANT4, and evaluated high dose deposited by Auger electrons. The dose distribution calculated by the PHITS code is exactly equivalent to that by Geant4. Also, the simulations are well agreement with experimental results. If the contribution of Auger electrons is ignored, the significantly high absorbed dose proximal to the source is not properly reduced. These findings demonstrate that Auger electrons work very effectively to kill cancer cells proximal to Cu-64 source while minimizing damage effects on normal cells distal to the source.
Zhang, Z,*; Wang, H.*; Yoshikawa, Hirofumi*; Matsumura, Daiju; Hatao, Shuya*; Ishikawa, Satoshi*; Ueda, Wataru*
ACS Applied Materials & Interfaces, 12(5), p.6056 - 6063, 2020/02
Times Cited Count：8 Percentile：25.48(Nanoscience & Nanotechnology)Murai, Naoki; Fukuda, Tatsuo; Nakajima, Masamichi*; Kawamura, Mitsuaki*; Ishikawa, Daisuke*; Tajima, Setsuko*; Baron, A. Q. R.*
Physical Review B, 101(3), p.035126_1 - 035126_6, 2020/01
Times Cited Count：7 Percentile：29.13(Materials Science, Multidisciplinary)We report an inelastic X-ray scattering investigation of phonons in FeSe superconductor. Comparing the experimental phonon dispersion with density functional theory (DFT) calculations in the non-magnetic state, we found a significant disagreement between them. A better overall agreement was obtained by allowing for spin-polarization in DFT calculations, despite the absence of magnetic order in FeSe. This calculation gives a realistic approximation, at DFT level, of the disordered paramagnetic state of FeSe, in which strong spin fluctuations are present.
gamma spectrometry intercomparison based on the information obtained through five intercomparisons during the Fukushima mapping projectMikami, Satoshi; Ishikawa, Daisuke*; Matsuda, Hideo*; Hoshide, Yoshifumi*; Okuda, Naotoshi*; Sakamoto, Ryuichi*; Saito, Kimiaki
Journal of Environmental Radioactivity, 210, p.105938_1 - 105938_7, 2019/12
Times Cited Count：5 Percentile：14.06(Environmental Sciences)Five intercomparisons of in situ 
spectrometry by 6-7 participating teams have been conducted between December 2011 and August 2015 at sites in Fukushima prefecture which affected by the fallout of FDNPS accident occurred in March 2011. The evaluated deposition densities agreed within 5-6% in terms of coefficient of variation (CV) for radiocesium (
Cs and 
Cs), by our best achievement, and the ratio of Cs/Cs in deposition density agreed within 1-2% in CV, through five intercomparisons. These results guarantee the accuracy of the measurements of the mapping project. Two different methods for intercomparison were conducted: (1) sequential measurements at an identical point; and (2) simultaneous measurements in a narrow area within 3 m radius. In a comparison between the two methods at a site, no significant difference was observed between the results. The standard protocols for the two different intercomparison methods were proposed based on our experience.
O(
He,
)F reaction; Identification of the low-energy "super" -Gamow-Teller stateFujita, Hirohiko*; Fujita, Yoshitaka*; Utsuno, Yutaka; Yoshida, Kenichi*; Adachi, Tatsuya*; Algora, A.*; Csatl
s, M.*; Deaven, J. M.*; Estevez-Aguado, E.*; Guess, C. J.*; et al.
Physical Review C, 100(3), p.034618_1 - 034618_13, 2019/09
Times Cited Count：18 Percentile：78.04(Physics, Nuclear)no abstracts in English
mesons as a probe of Casimir effect for chiral symmetry breakingIshikawa, Tsutomu*; Nakayama, Katsumasa*; Suenaga, Daiki*; Suzuki, Kei
Physical Review D, 100(3), p.034016_1 - 034016_14, 2019/08
Times Cited Count：8 Percentile：31.32(Astronomy & Astrophysics)We propose mesons as probes to investigate finite-volume effects for chiral symmetry breaking at zero and finite temperatures. By using the 2+1-flavor linear sigma model with constituent light quarks, we analyze the Casimir effects for the 
mean fields; the chiral symmetry is rapidly restored by the antiperiodic boundary for light quarks, and the chiral symmetry breaking is catalyzed by the periodic boundary. We also show the phase diagram of the mean fields on the volume and temperature plane. For mesons, we employ an effective model based on the chiral-partner structure, in which the volume dependence of mesons is induced by the mean fields. We find that 
mesons are less sensitive to finite volume than mesons, which is caused by the insensitivity of 
mean fields. An anomalous mass shift of mesons at high temperature with the periodic boundary will be useful in examinations with lattice QCD simulations. The dependence on the number of compactified spatial dimensions is also studied.
Nakajima, Kenji; Kawakita, Yukinobu; Ito, Shinichi*; Abe, Jun*; Aizawa, Kazuya; Aoki, Hiroyuki; Endo, Hitoshi*; Fujita, Masaki*; Funakoshi, Kenichi*; Gong, W.*; et al.
Quantum Beam Science (Internet), 1(3), p.9_1 - 9_59, 2017/12
The neutron instruments suite, installed at the spallation neutron source of the Materials and Life Science Experimental Facility (MLF) at the Japan Proton Accelerator Research Complex (J-PARC), is reviewed. MLF has 23 neutron beam ports and 21 instruments are in operation for user programs or are under commissioning. A unique and challenging instrumental suite in MLF has been realized via combination of a high-performance neutron source, optimized for neutron scattering, and unique instruments using cutting-edge technologies. All instruments are/will serve in world-leading investigations in a broad range of fields, from fundamental physics to industrial applications. In this review, overviews, characteristic features, and typical applications of the individual instruments are mentioned.
As using high-resolution inelastic X-ray scatteringMurai, Naoki*; Fukuda, Tatsuo; Kobayashi, Tatsuya*; Nakajima, Masamichi*; Uchiyama, Hiroshi*; Ishikawa, Daisuke*; Tsutsui, Satoshi*; Nakamura, Hiroki; Machida, Masahiko; Miyasaka, Shigeki*; et al.
Physical Review B, 93(2), p.020301_1 - 020301_5, 2016/01
Times Cited Count：7 Percentile：29.53(Materials Science, Multidisciplinary)Uematsu, Daisuke*; Sagayama, Hajime*; Arima, Takahisa*; Ishikawa, Jun*; Nakatsuji, Satoru*; Takagi, Hidenori*; Yoshida, Masahiro*; Mizuki, Junichiro; Ishii, Kenji
Physical Review B, 92(9), p.094405_1 - 094405_6, 2015/09
Times Cited Count：27 Percentile：67.90(Materials Science, Multidisciplinary)