Research and development of radiation-resistant sensor for fuel debris by integrating advanced measurement technologies (Contract research); FY2020 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; High Energy Accelerator Research Organization*

JAEA-Review 2021-042, 115 Pages, 2022/01

JAEA-Review-2021-042.pdf:5.18MB

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 FY2018, this report summarizes the research results of the "Research and development of radiation-resistant sensor for fuel debris by integrating advanced measurement technologies" conducted from FY2018 to FY2020. Since the final year of this proposal was FY2020, the results for three fiscal years were summarized. The present study aims to in-situ measure and analyze the distribution status and criticality of flooded fuel debris. For this purpose, we construct a neutron measurement system by developing compact diamond neutron sensor and integrated circuit whose radiation resistance was improved by circuit design.

Research and development of radiation-resistant sensor for fuel debris by integrating advanced measurement technologies (Contract research); FY2018 Center of World Intelligence Project for Nuclear Science/Technology and Human Resource Development

Collaborative Laboratories for Advanced Decommissioning Science; High Energy Accelerator Research Organization*

JAEA-Review 2019-040, 77 Pages, 2020/03

JAEA-Review-2019-040.pdf:4.61MB

JAEA/CLADS, had been conducting the Center of World Intelligence Project for Nuclear Science/Technology and Human Resource Development (hereafter referred to "the Project") in FY2018. The Project aims to contribute to solving problems in nuclear energy field represented by the decommissioning of the Fukushima Daiichi Nuclear Power Station, Tokyo Electric Power Company Holdings, Inc. 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 FY2018, this report summarizes the research results of the "Research and Development of Radiation-resistant Sensor for Fuel Debris by Integrating Advanced Measurement Technologies". The present study aims to in-situ measure and analyze the distribution status and criticality of flooded fuel debris. For this purpose, we construct a neutron measurement system by developing compact diamond neutron sensor (200 m 510 m thickness) and integrated circuit whose radiation resistance was improved by circuit design. Along with the multi-phased array sonar and the acoustic sub-bottom profiling (SBP) system, the neutron measurement system will be installed in the ROV (developed by Japan-UK collaboration) and its demonstration tests will be conducted in a PCV mock-up water tank.

Energetic deuterium and helium irradiation effects on chemical structure of CVD diamond

Sasaki, Masayoshi*; Morimoto, Yasutomi*; Kimura, Hiromi*; Takahashi, Koji; Sakamoto, Keishi; Imai, Tsuyoshi; Okuno, Kenji*

Journal of Nuclear Materials, 329-333(Part1), p.899 - 903, 2004/08

https://doi.org/10.1016/j.jnucmat.2004.04.275

A CVD diamond has been the reference material of a torus widow for a rf heating system in a fusion reactor. Since the window is in the circumstance of tritium, helium and radio activated dust, it is important to elucidate the effect of ions on chemical structure of the diamond, existing states of tritium and tritium inventory. Polycrystalline CVD diamond disks(=10.0mm, t=0.21mm) used in this study are the same grade as rf windows. After sputtering the surface with 1.0 keV Ar to remove oxygen impurity, the sample was irradiated with deuterium (D) or helium ions (He) at an angle of 0 degrees to the surface normal. The irradiation energies of deuterium and helium are 0.25 keV D and 0.45 keV He, respectively. The structural change of the irradiated sample was measured by X-ray Photoelectron Spectroscopy (XPS) technique. The C1s peak shift toward lower binding energy side was observed when deuterium ions irradiated. This result indicates that the diamond changes to amorphous carbon due to formation of C-D bond.

The Toughness of free-standing CVD diamond

Davies, A. R.*; Field, J. E.*; Takahashi, Koji; Hada, Kazuhiko

Journal of Materials Science, 39(5), p.1571 - 1574, 2004/03

https://doi.org/10.1023/B:JMSC.0000016153.90600.a6

A four-point bend test was used to determine the fracture toughness of mechanical grade and di-electric (optical) grade chemical vapour deposited (CVD) diamond. The validity of the test was first confirmed by measuring the toughness of alumina and confirming the results with literature values. The toughnesses of both types of CVD were similar; 8.51.0 and 8.30.4 MPa () respectively. This is higher than the value of 3.40.5 MPa () measured for diamond by Field and Freeman, 1981 using an indentation technique. It is suggested that this is primarily due to differences in surface roughness. There were enough samples to make a preliminary study of the effect of temperature and these data are reported.

Plan to development of ZrC-TRISO coated fuel particle and construction of ZrC coater

Ueta, Shohei; Tobita, Tsutomu*; Ino, Hiroichi*; Takahashi, Masashi*; Sawa, Kazuhiro

JAERI-Tech 2002-085, 41 Pages, 2002/11

JAERI-Tech-2002-085.pdf:2.66MB

no abstracts in English

Stress analysis of CVD diamond window for ECH system

Takahashi, Koji; Komatsuzaki, Manabu*

JAERI-Research 2000-054, 23 Pages, 2001/03

JAERI-Research-2000-054.pdf:1.37MB

no abstracts in English

Chemical vapor deposition diamond window as vacuum and tritium confinement barrier for fusion application

Takahashi, Koji; Sakamoto, Keishi; Kasugai, Atsushi; Imai, Tsuyoshi; Brandon, J. R.*; Sussmann, R. S.*

Review of Scientific Instruments, 71(11), p.4139 - 4143, 2000/11

https://doi.org/10.1063/1.1313799

no abstracts in English

A Crystalline hydrogenated carbon film obtained by plasma enhanced chemical vapor deposition

Zhang, Z.*; Narumi, Kazumasa; Naramoto, Hiroshi; Wu, Z.*; Yamamoto, Shunya; Miyashita, Atsumi; Tamada, Masao

Journal of Applied Physics, 86(3), p.1317 - 1321, 1999/08

https://doi.org/10.1063/1.370888

no abstracts in English

High power operation of Gaussian beam gyrotron with CVD diamond window for JT-60U

Kasugai, Atsushi; Takahashi, Koji; Sakamoto, Keishi; *; Mitsunaka, Yoshika*; ; Ikeda, Yoshitaka; Tsuneoka, Masaki; Imai, Tsuyoshi

Proc. of 13th Topical Conf. on Applications of Radio Frequency Power to Plasmas, p.449 - 452, 1999/00

no abstracts in English

Development of radiation detectors using synthetic diamond crystals

Kaneko, Junichi; Katagiri, Masaki; Ikeda, Yujiro; Nishitani, Takeo

Advanced Materials'98;Advanced Materials Research Utilizing Extreme Conditions, p.257 - 260, 1998/00

no abstracts in English