Research and development of the sample-return technique for fuel debris using the unmanned underwater vehicle (Contract research); FY2021 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; National Institute of Maritime, Port and Aviation Technology*

JAEA-Review 2022-070, 70 Pages, 2023/03

JAEA-Review-2022-070.pdf:5.27MB

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 FY2021. 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 FY2020, this report summarizes the research results of the "Research and development of the sample-return technique for fuel debris using the unmanned underwater vehicle" conducted in FY2021. The present study aims to develop a fuel debris sampling device that comprises a neutron detector with radiation resistance and enhanced neutron detection efficiency, an end-effector with powerful cutting and collection capabilities, and a manipulator under the Japan-UK joint research team. We will also develop a fuel debris sampling system that can be mounted on an unmanned vehicle. In addition, we will develop a positioning system to identify the system position, and a technique to project the counting information of optical cameras, sonar, and neutron detectors to be developed ...

Research and development of the sample-return technique for fuel debris using the unmanned underwater vehicle (Contract research); FY2020 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; National Institute of Maritime, Port and Aviation Technology*

JAEA-Review 2021-049, 67 Pages, 2022/01

JAEA-Review-2021-049.pdf:7.54MB

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 FY2020. 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 FY2020, this report summarizes the research results of the "Research and development of the sample-return technique for fuel debris using the unmanned underwater vehicle" conducted in FY2020. The present study aims to develop a fuel debris sampling device that comprises a neutron detector with radiation resistance and enhanced neutron detection efficiency, an end-effector with powerful cutting and collection capabilities, and a manipulator under the Japan-UK joint research team. We will also develop a fuel debris sampling system that can be mounted on an unmanned vehicle. In addition, we will develop a positioning system to identify the system position, and a technique to project the counting information of optical cameras, sonar, …

Development of radiation hard diamond image sensing devices (Contract research); FY2019 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; National Institute of Advanced Industrial Science and Technology*

JAEA-Review 2020-027, 27 Pages, 2021/01

JAEA-Review-2020-027.pdf:2.98MB

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 FY2019. 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 radiation hard diamond image sensing devices". The research objective of this project is to develop image sensing devices which work under the high radiation condition. The devices will be realized using radiation hard diamond semiconductor devices as charge transfer devices and photodetectors. The research project has mainly two targets such as to confirm charge coupled devices operation on diamond unipolar devices and to characterize photo conductivity of diamond detectors.

Evaluation of thermal strain induced in components of NbSn strand during cooling

Suwa, Tomone*; Hemmi, Tsutomu*; Saito, Toru*; Takahashi, Yoshikazu*; Koizumi, Norikiyo*; Luzin, V.*; Suzuki, Hiroshi; Harjo, S.

IEEE Transactions on Applied Superconductivity, 28(3), p.6001104_1 - 6001104_4, 2018/04

https://doi.org/10.1109/TASC.2018.2793190

Direct observation of fast lithium-ion diffusion in a superionic conductor; LiPS metastable crystal

Mori, Kazuhiro*; Enjuji, Keigo*; Murata, Shun*; Shibata, Kaoru; Kawakita, Yukinobu; Yonemura, Masao*; Onodera, Yohei*; Fukunaga, Toshiharu*

Physical Review Applied (Internet), 4(5), p.054008_1 - 054008_6, 2015/11

https://doi.org/10.1103/PhysRevApplied.4.054008

no abstracts in English

Overview of national centralized tokamak program; Mission, design and strategy to contribute ITER and DEMO

Ninomiya, Hiromasa; Akiba, Masato; Fujii, Tsuneyuki; Fujita, Takaaki; Fujiwara, Masami*; Hamamatsu, Kiyotaka; Hayashi, Nobuhiko; Hosogane, Nobuyuki; Ikeda, Yoshitaka; Inoue, Nobuyuki; et al.

Journal of the Korean Physical Society, 49, p.S428 - S432, 2006/12

To contribute DEMO and ITER, the design to modify the present JT-60U into superconducting coil machine, named National Centralized Tokamak (NCT), is being progressed under nationwide collaborations in Japan. Mission, design and strategy of this NCT program is summarized.

Doping Momentum dependence of charge dynamics in NdCeCuO (x=0, 0.075, and 0.15) studied by Resonant inelastic X-ray scattering

Ishii, Kenji; Tsutsui, Kenji*; Endo, Yasuo*; Toyama, Takami*; Maekawa, Sadamichi*; Hoesch, M.; Kuzushita, Kaori; Inami, Toshiya; Tsubota, Masami; Yamada, Kazuyoshi*; et al.

AIP Conference Proceedings 850, p.403 - 404, 2006/09

https://doi.org/10.1063/1.2354756

We report a resonant inelastic X-ray scattering (RIXS) study of charge excitations in the electron-doped high- superconductor NdCeCuO. The intraband and interband excitations across the Fermi energy are separated for the first time by tuning the experimental conditions properly to measure charge excitations at low energy. A dispersion relation with -dependent width emerges clearly in the intraband excitation, while the intensity of the interband excitation is concentrated around 2 eV near the zone center. The experimental results are consistent with theoretical calculation of the RIXS spectra based on the Hubbard model.

Design study of a neutral beam injector for fusion DEMO plant at JAERI

Inoue, Takashi; Hanada, Masaya; Kashiwagi, Mieko; Nishio, Satoshi; Sakamoto, Keishi; Sato, Masayasu; Taniguchi, Masaki; Tobita, Kenji; Watanabe, Kazuhiro; DEMO Plant Design Team

Fusion Engineering and Design, 81(8-14), p.1291 - 1297, 2006/02

https://doi.org/10.1016/j.fusengdes.2005.08.074

Requirement and technical issues of the neutral beam inejctor (NBI) is discussed for fusion DEMO plant. The NBI for the fusion DEMO plant should be high efficiency, high energy and high reliability with long life. From the view point of high efficiency, use of conventional electrostatic accelerator is realistic. Due to operation under radiation environment, vacuum insulation is essential in the accelerator. According to the insulation design guideline, it was clarified that the beam energy of 1.52 MeV is possible in the accelerator. Development of filamentless, and cesium free ion source is required, based on the existing high current/high current density negative ion production technology. The gas neutralization is not applicable due to its low efficiency (60%). R&D on an advanced neutralization scheme such as plasma neutralization (efficiency: 80%) is required. Recently, development of cw high power semiconductor laser is in progress. The paper shows a conceptual design of a high efficiency laser neutralizer utilizing the new semiconductor laser array.

Effective bending strain estimated from test results of a D-shaped NbAl CICC coil fabricated with a react-and-wind process for the National Centralized Tokamak

Ando, Toshinari*; Kizu, Kaname; Miura, Yushi*; Tsuchiya, Katsuhiko; Matsukawa, Makoto; Tamai, Hiroshi; Ishida, Shinichi; Koizumi, Norikiyo; Okuno, Kiyoshi

Fusion Engineering and Design, 75-79, p.99 - 103, 2005/11

https://doi.org/10.1016/j.fusengdes.2005.06.264

no abstracts in English

Novel pressure phase diagram of heavy fermion superconductor CePtSi investigated by ac calorimetry

Tateiwa, Naoyuki; Haga, Yoshinori; Matsuda, Tatsuma; Ikeda, Shugo; Yasuda, Takashi*; Takeuchi, Tetsuya*; Settai, Rikio*; Onuki, Yoshichika

Journal of the Physical Society of Japan, 74(7), p.1903 - 1906, 2005/07

https://doi.org/10.1143/JPSJ.74.1903

The pressure dependences of the antiferromagnetic and superconducting transition temperatures have been investigated by ac heat capacity measurement under high pressures for the heavy-fermion superconductor CePtSi without inversion symmetry in the tetragonal structure. The Nel temperature = 2.2 K decreases with increasing pressure and becomes zero at the critical pressure 0.6 GPa. On the other hand, the superconducting phase exists in a wider pressure region from ambient pressure to about 1.5 GPa. The pressure phase diagram of CePtSi is thus very unique and has never been reported before for other heavy fermion superconductors.