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Shi, W.*; Machida, Masahiko; Yamada, Susumu; Okamoto, Koji*
Measurement, 258(Part D), p.119444_1 - 119444_15, 2026/01
Teshigawara, Makoto; Ikeda, Yujiro*; Muramatsu, Kazuo*; Sutani, Koichi*; Kimijima, Koichi*; Fukuzumi, Masafumi*; Noda, Yohei*; Koizumi, Satoshi*; Kawamura, Yuji*; Saruta, Koichi; et al.
Canadian Journal of Physics, 103(12), p.1225 - 1231, 2025/12
Times Cited Count：0 Percentile：0.00Science using neutrons in the nanometer (nm) wavelength region as probes is expanding into a wide range of fields, from basic research in materials and life science to industrial applications. Dramatic increase in the intensity of the beam source is required to drive such research. We have focused on coherent scattering caused by nano-sized particle aggregations to increase the intensity of neutron beams. Nanodiamond is being vigorously researched and developed with the aim of practical application. On the other hand, we have focused on graphene, which has higher van der Waals forces by an order of magnitude and stronger bonding, sp2, between carbons than nanodiamond. This is expected to lead to its processability into a lumped for and to adapt to higher radiation fields. By promoting chemical vapor deposition (CVD), we have established a technique to form nano-sized graphene (called graphene flower) with a shape similar to a sunflower flower. In this talk, we report on the neutron scattering properties that contribute to the coherent scattering of the newly developed graphene flower.
Koizumi, Mitsuo; Yogo, Akifumi*
Isotope News, (802), p.11 - 14, 2025/12
no abstracts in English
Collaborative Laboratories for Advanced Decommissioning Science; Tohoku University*
JAEA-Review 2025-011, 74 Pages, 2025/08
JAEA-Review-2025-011.pdf:5.31MB
The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Nuclear Energy Science &Z Technology and Human Resource Development Project (hereafter referred to "the Project") in FY2023. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. (TEPCO). For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2021, this report summarizes the research results of the "Development of a cooperative operation robot system for radiation source exploration" conducted from FY2021 to FY2023. The present study aims to develop a robot system (CORRASE: Cooperative Operation Robot system for RAdiation Source Exploration), realizing radiation source exploration with wide field of view, rapidity, and low cost. In FY2023, our research efforts focused on verification tests for radiation source exploration by summarizing the results of our previous studies. Polyhedral type gamma-ray directional detectors were fabricated from 8 BGO scintillators and shielding bodies. Radiation source exploration experiments were performed by developing a cooperative operation robot system consisting of 3 multi-legged robots carrying the gamma-ray detectors, IMUs (Inertial Measurement Units), and LiDARs (Light Detection And Ranging). An unknown test environment for the radiation source exploration was constructed by placing obstacles and a 10 MBq 
Cs sealed source as a simulated radioactive contamination source in a room measuring 7.8 
5.3 m
. The developed system was used to create the environmental map, to formulate the exploration plan, to create the heatmap of the radiation counts, and to image the radiation source from the calculated optimal observation position. The localization of the simulated radioactive contamination source was successfully performed with the cooperation of the 3 robot systems by displaying the image of the radiation source fused on the environmental map. It can be concluded that the initial goal of this study has been successfully achieved by developing the robot system realizing radiation source exploration.
Collaborative Laboratories for Advanced Decommissioning Science; Fukushima University*
JAEA-Review 2025-002, 108 Pages, 2025/07
JAEA-Review-2025-002.pdf:5.25MB
The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project (hereafter referred to "the Project") in FY2023. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. (TEPCO). For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2019, this report summarizes the research results of the "Development of methodology combining chemical analysis technology with informatics technology to understand perspectives property of debris and tie-up style human resource development" conducted from FY2019 to FY2023. The present study aims to Goal of this study is to implement a research plan relate to a development of combinational technology of new chemical analysis with informatics, and the aim is to develop new system for whole image estimation system using small quantities of information. Conducting the collaboration study with JAEA researchers (tie-up style) make connect to the development of human resource from master's course student to post-doctoral researchers who are progress in the local-based and/or many academics fields research. We are in progress to grow international-minded human resources.
Haga, Katsuhiro; Naoe, Takashi; Kogawa, Hiroyuki; Wakui, Takashi; Kinoshita, Hidetaka; Harada, Masahide
Proceedings of 16th International Particle Accelerator Conference (IPAC25) (Internet), p.3245 - 3249, 2025/06
In April 2024, the beam power at MLF attained 950 kW for the first time for long term user operation, and the beam power at the 3 GeV rapid cycle synchrotron (RCS) outlet was raised to 1 MW. This accomplishment means that the goal of the stable operation of the neutron source with 1 MW was almost achieved at last, and it's time to go on to the new stage of the neutron source R&D. There are two major challenges for the mercury target in the next stage. One is to attain the long-term operation of a mercury target. The service life of the target vessel is primarily determined by cavitation damage that occurs on the inner surface due to the injection of high-intensity pulsed proton beams. Until now, the vessel has been replaced annually to inspect the extent of the damage. However, based on the damage data obtained during 1 MW high-power operation, it has been determined that the vessel can withstand long-term operation for more than two years. Therefore, a new target vessel, which was replaced in 2024, is scheduled to be used for an extended period through 2027. Furthermore, since there are plans to increase the pulse intensity of the RCS in the future, it will be necessary to develop more effective pitting damage suppression techniques and new target vessels that can withstand even stronger proton beam pulses. In this presentation, the present status of the neutron source of MLF and future operation plans will be shown.
Usami, Hiroshi; Yoshinaga, Kyohei*; Fujikawa, Keigo*
Nihon Genshiryoku Gakkai-Shi ATOMO
, 67(5), p.295 - 299, 2025/05
no abstracts in English
Tanabe, Kosuke*; Komeda, Masao; Toh, Yosuke; Kitamura, Yasunori*; Misawa, Tsuyoshi*
Nihon Genshiryoku Gakkai-Shi ATOMO, 67(3), p.198 - 202, 2025/03
no abstracts in English
Brumm, S.*; Gabrielli, F.*; Sanchez Espinoza, V.*; Stakhanova, A.*; Groudev, P.*; Petrova, P.*; Vryashkova, P.*; Ou, P.*; Zhang, W.*; Malkhasyan, A.*; et al.
Annals of Nuclear Energy, 211, p.110962_1 - 110962_16, 2025/02
Times Cited Count：9 Percentile：95.35(Nuclear Science & Technology)Usami, Hiroshi; Ito, Rintaro; Tagawa, Akihiro
JAEA-Review 2024-045, 49 Pages, 2024/12
JAEA-Review-2024-045.pdf:13.38MB
The decommissioning of the TEPCO's Fukushima Daiichi Nuclear Power Station is a long-term project, and the training of young engineers and researchers who will be responsible for future decommissioning is a necessary and urgent task. Since 2016, Collaborative Laboratories for Advanced Decommissioning Science has been continuously organizing "Conferences for R&D Initiative on Nuclear Decommissioning Technology by the Next Generation (NDEC)" for students who are engaged in research activities for decommissioning. NDEC is a forum for students to present their research for the purpose of human resource development and networking among young researchers, and to increase their motivation for decommissioning research. NDEC-9 was held at "Manabi-no-Mori" in Tomioka-machi, Fukushima Prefecture, from March 21-22, 2024. This proceeding compiles the contents of report papers in the conference.
Wakui, Takashi; Saito, Shigeru; Futakawa, Masatoshi
Jikken Rikigaku, 24(4), p.212 - 218, 2024/12
Irradiation damage is one of the main factors determining the lifetime of the mercury target vessel for spallation neutron source in J-PARC. To understand material degradation of the used vessels, it is planned to conduct an evaluation using inverse analyses with indentation tests on the structural materials of the used vessels and numerical experiments. This evaluation technique was applied to two kinds of ion-irradiated materials with different displacement damage doses, in which the irradiation condition was simulated. It could be confirmed that the ultimate strength increased, and the total elongation decreased with increasing irradiation. These trends are like the material degradation behaviors which have been reported by using small specimen's tensile tests.
Koizumi, Mitsuo; Ito, Fumiaki*; Lee, J.; Hironaka, Kota; Takahashi, Tone; Suzuki, Satoshi*; Arikawa, Yasunobu*; Abe, Yuki*; Wei, T.*; Yogo, Akifumi*; et al.
Dai-45-Kai Nihon Kaku Busshitsu Kanri Gakkai Nenji Taikai Kaigi Rombunshu (Internet), 4 Pages, 2024/11
Teshigawara, Makoto; Ikeda, Yujiro*; Muramatsu, Kazuo*; Sutani, Koichi*; Fukuzumi, Masafumi*; Noda, Yohei*; Koizumi, Satoshi*; Saruta, Koichi; Otake, Yoshie*
Journal of Neutron Research, 26(2-3), p.69 - 74, 2024/09
Slow neutrons, such as cold neutrons, are important non-destructive probes not only for basic physics but also for the structural genomics advancements in the life sciences and the battery technology advancements needed for the transition to a hydrogen society. Neutron-based science is also known as high-neutron-intensity-dependent science. A new unique method focusing on nanosized particle aggregation has been proposed to increase neutron intensity in that energy region. The method is based on intensity enhancement by multiple coherent scatterings with nanosized particle aggregation. The aggregation of nanosized particles matches the wavelength of below cold neutrons, causing a similar effect to coherent scattering, so-called Bragg scattering, leading to neutron intensity enhancement by several orders of magnitude. Nanodiamonds and magnesium hydride have recently been studied numerically and experimentally. The major challenge with nanodiamonds in practical applications is the molding method. Another carbon structure, graphene is focused on to find a solution to this problem. It is hypothesized that nanosized graphene could aid coherent neutron scattering under particle size conditions similar to nanodiamonds. We report the potential of nanosized graphene as a reflector material below cold neutrons, together with experimental results.
Koizumi, Mitsuo; Ito, Fumiaki*; Lee, J.; Hironaka, Kota; Takahashi, Tone; Suzuki, Satoshi*; Arikawa, Yasunobu*; Abe, Yuki*; Lan, Z.*; Wei, T.*; et al.
Scientific Reports (Internet), 14, p.21916_1 - 21916_9, 2024/09
Times Cited Count：2 Percentile：57.51(Multidisciplinary Sciences)Collaborative Laboratories for Advanced Decommissioning Science; Fukushima University*
JAEA-Review 2023-024, 109 Pages, 2024/03
JAEA-Review-2023-024.pdf:5.42MB
The Collaborative Laboratories for Advanced Decommissioning Science (CLADS), Japan Atomic Energy Agency (JAEA), had been conducting the Nuclear Energy Science & Technology and Human Resource Development Project (hereafter referred to "the Project") in FY2022. The Project aims to contribute to solving problems in the nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. (TEPCO). For this purpose, intelligence was collected from all over the world, and basic research and human resource development were promoted by closely integrating/collaborating knowledge and experiences in various fields beyond the barrier of conventional organizations and research fields. The sponsor of the Project was moved from the Ministry of Education, Culture, Sports, Science and Technology to JAEA since the newly adopted proposals in FY2018. On this occasion, JAEA constructed a new research system where JAEA-academia collaboration is reinforced and medium-to-long term research/development and human resource development contributing to the decommissioning are stably and consecutively implemented. Among the adopted proposals in FY2019, this report summarizes the research results of the "Development of methodology combining chemical analysis technology with informatics technology to understand perspectives property of debris and tie-up style human resource development" conducted in FY2022. The present study aims to goal of this study is to implement a research plan relate to a development of combinational technology of new chemical analysis with informatics, and the aim is to develop new system for whole image estimation system using small quantities of information.
Morimoto, Kyoichi; Ono, Takahiro; Kakutani, Satomi; Yoshida, Moeka; Suzuki, Soichiro
Journal of Robotics and Mechatronics, 36(1), p.125 - 133, 2024/02
The Naraha Center for Remote Control Technology Development was established for the purpose of developing and verifying remote control equipment for promoting the decommissioning of the Fukushima Daiichi Nuclear Power Station and the external use of this center was started in 2016. The mission of this center is to contribute to the decommissioning of the Fukushima Daiichi Nuclear Power Station and for the reconstruction of Fukushima Prefecture. In this review, we describe the equipment related to the full-scale mock-up test, the component test for a remote-control device and the virtual reality system in this center. In addition, the case examples for usage of these equipment are introduced.
Sato, Yuki
Applied Radiation and Isotopes, 203, p.111083_1 - 111083_9, 2024/01
Times Cited Count：5 Percentile：68.50(Chemistry, Inorganic & Nuclear)Fukahori, Tokio; Nakayama, Shinsuke; Katabuchi, Tatsuya*; Shigyo, Nobuhiro*
Nihon Genshiryoku Gakkai-Shi ATOMO, 65(12), p.726 - 727, 2023/12
The Investigative Committee on Nuclear Data investigates and observes global trends in nuclear research and development and conducts comprehensive examinations of Japanese nuclear data activities from a broader perspective, as well as cooperation with domestic and foreign academic institutions in a wide range of fields other than the Atomic Energy Society. We aim to establish a system for communication, information exchange, and interdisciplinary cooperation. In this report, we will report on three of the main activities for the 2021-2022 term: a request list site for nuclear data, human resource development, and roadmap production.
Nagai, Haruyasu; Furuta, Yoshihiro*; Nakayama, Hiromasa; Satoh, Daiki
Journal of Nuclear Science and Technology, 60(11), p.1345 - 1360, 2023/11
Times Cited Count：4 Percentile：59.67(Nuclear Science & Technology)A novel monitoring method for the quantitative visualization of 3D distribution of a radioactive plume and source term estimation of released radionuclides is proposed and its feasibility is demonstrated by preliminary test. The proposed method is the combination of gamma-ray imaging spectroscopy with the Electron Tracking Compton Camera (ETCC) and real-time high-resolution atmospheric dispersion simulation based on 3D wind observation with Doppler lidar. The 3D distribution of a specific radionuclide in a target radioactive plume is inversely reconstructed from line gamma-ray images from each radionuclide by several ETCCs located around the target by harmonizing with the air concentration distribution pattern of the plume predicted by real-time atmospheric dispersion simulation. A prototype of the analysis method was developed, showing a sufficient performance in several test cases using hypothetical data generated by numerical simulations of atmospheric dispersion and radiation transport.
Katsumura, Kosuke*; Takagi, Junichi*; Hosomi, Kenji*; Miyahara, Naoya*; Koma, Yoshikazu; Imoto, Jumpei; Karasawa, Hidetoshi; Miwa, Shuhei; Shiotsu, Hiroyuki; Hidaka, Akihide*; et al.
Nihon Genshiryoku Gakkai-Shi ATOMO, 65(11), p.674 - 679, 2023/11
no abstracts in English
