Development of radiation field mapping measurement system based on high radiation tolerant solar cells for low-light illumination (Contract research); FY2023 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; Institute of Physical and Chemical Research*

JAEA-Review 2025-031, 124 Pages, 2025/12

JAEA-Review-2025-031.pdf:7.93MB

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 (1F), 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 FY2022, this report summarizes the research results of the "Development of radiation field mapping measurement system based on high radiation tolerant solar cells for low-light illumination" conducted in FY2023. The present study aims to develop a system that can map radiation fields by applying independent and remotely operated sensors to obtain radiation information in the Primary Containment Vessel (PCV) in real time. The system will be implemented in a real environment to ensure the safety of workers and equipment by monitoring the leakage of gamma rays and neutrons, which are highly penetrating and can be a cause of accidents. A solar cell dosimeter is being developed as a compact sensor of the built-in potential drive type that utilizes a device with high radiation tolerance that has been developed as a solar cell for space use. The CIGS solar cell dosimeter is the basis for the development of a system with high functionality and systemization for 1F packaging. In FY2023, we will investigate the conditions for creating a flexible device based on the structure of a CIGS solar cell device, and clarify the initial characteristics of a prototype device using a CIGS device on a glass substrate through irradiation tests using gamma rays, electron beams, and neutron beams. In the neutron detection structure, we will explore the conditions for applying the conversion material boron, investigate the conditions for adjusting the particle size of the powder material by milling, and select the coating method and solvent conditions. In mapping measurements, we will develop a system that can display dose information by measuring multiple sensors.

Development of hydrogels for prevention of radioactive dust dispersion during fuel debris retrieval (Contract research); FY2019 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; Osaka University*

JAEA-Review 2020-030, 55 Pages, 2020/12

JAEA-Review-2020-030.pdf:2.76MB

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 FY2018, this report summarizes the research results of the "Development of hydrogels for prevention of radioactive dust dispersion during fuel debris retrieval" conducted in FY2019. In this study, we propose coating fuel debris with thixotropic gel materials to suppress dust dispersion during debris retrieval. Hectorite clay mineral - borax composite gel was selected based on the viscosity, the transparency and the radiation resistance. Simulated cutting tests confirm that the gel coating effectively suppress the dust dispersion.

Study on Pu-burner high temperature gas-cooled reactor in Japan; Test and characterization for ZrC coating

Ueta, Shohei; Aihara, Jun; Mizuta, Naoki; Goto, Minoru; Fukaya, Yuji; Tachibana, Yukio; Okamoto, Koji*

Proceedings of 9th International Topical Meeting on High Temperature Reactor Technology (HTR 2018) (USB Flash Drive), 7 Pages, 2018/10

The security and safety fuel (3S-TRISO fuel) employs the coated fuel particle with a fuel kernel made of plutonium dioxide (PuO) and yttria stabilized zirconia (YSZ) as an inert matrix. Especially, a zirconium carbide (ZrC) coating is one of key technologies of the 3S-TRISO, which performs as an oxygen getter to reduce the fuel failure due to internal pressure during the irradiation. R&Ds on ZrC coating directly on the dummy CeO-YSZ kernel have been carried in the Japanese fiscal year 2017. As results of ZrC coating tests by the bromide chemical vapor deposition process, stoichiometric ZrC coatings with 3 - 18 microns of thicknesses were obtained with 0.1 kg of particle loading weight.

Development of a dummy load and waveguide components for 1 MW CW gyrotron

Ioki, Kimihiro*; Hiranai, Shinichi; Moriyama, Shinichi; Tanaka, Suguru*

Fusion Engineering and Design, 109-111(Part A), p.951 - 955, 2016/11

https://doi.org/10.1016/j.fusengdes.2016.01.046

A dummy load dissipates the RF power and is required to test and adjust a gyrotron or a transmission line. The most critical issue is long-term reliability in the vacuum and coolant boundary of the rotation mechanism for current large-scale dummy loads. A new design has been developed to use linear movement for the reflector assembly to mitigate the heat deposition concentration. The thickness distribution of the ceramic layer is carefully analyzed and optimized. A prototypical dummy load will be manufactured as the next step.

Investigation of hydrogen isotope permeation through F82H steel with and without a ceramic coating of CrO-SiO including CrPO, Out-of-pile tests

Kulsartov, T. V.*; Hayashi, Kimio; Nakamichi, Masaru*; Afanasyev, S. E.*; Shestakov, V. P.*; Chikhray, Y. V.*; Kenzhin, E. A.*; Kolbaenkov, A. N.*

Fusion Engineering and Design, 81(1-7), p.701 - 705, 2006/02

https://doi.org/10.1016/j.fusengdes.2005.07.019

no abstracts in English

Development of SiC coatings on AlO ceramics from precursor polymers by radiation curing

Wach, R.; Sugimoto, Masaki; Lam, N. D.; Yoshikawa, Masahito

Proceedings of 8th SPSJ International Polymer Conference (IPC 2005) (CD-ROM), 60 Pages, 2005/07

no abstracts in English

Development of cold isostatic pressing graphite module for a heat-resistant lower hybrid current drive antenna

Maebara, Sunao; Goniche, M.*; Kazarian, F.*; Seki, Masami; Ikeda, Yoshitaka; Imai, Tsuyoshi*; Beaumont, B.*

Review of Scientific Instruments, 76(5), p.053501_1 - 053501_7, 2005/05

https://doi.org/10.1063/1.1891465

Development of a plasma facing module using Cold Isostatic Pressing Graphite (CIPG) had been done for a heat-resistant LHCD antenna. A thin stainless film (10m), molybdenum film (10m) and copper film (50m) are laid to overlap each other on the CIPG materials, the CIPG surfaces were successfully coated with copper layer by diffusion bonding method. This module has four waveguides and a water cooling channel, the length is 206 mm. High power long pulse operation was successfully achieved up to 250 kW (125 MW/m)/700s. The module has been successfully tested at a RF power density which is equivalent, in terms of RF electric field (5kV/cm), to the one proposed for the LHCD antenna of ITER-FEAT. The outgassing rate of the copper-coated CIPG is estimated to be 3.2-5.110 Pa.m/s.m at 100C, it is assessed that a pumping system is not required to evacuate the pressure in the LHCD antenna.

R&D of a MW-class solid-target for spallation neutron source

Kawai, Masayoshi*; Furusaka, Michihiro*; Kikuchi, Kenji; Kurishita, Hiroaki*; Watanabe, Ryuzo*; Li, J.*; Sugimoto, Katsuhisa*; Yamamura, Tsutomu*; Hiraoka, Yutaka*; Abe, Katsunori*; et al.

Journal of Nuclear Materials, 318, p.35 - 55, 2003/05

R&D works for MW class solid target composed of tungsten to produce pulsed intense neutron source has been made in order to construct a future scattering facility. Three methods were investigated to prevent corrosion of tungsten from water; those are hipping, brazing and electric coating in molten salt bath. Hipping condition was optimized to be 1500 degree C in the previous work: here small punch test shows highest load for crack initiation of hipped materials at the boundary of W/Ta. The basic techniques for the other two methods were developed. Erosion test showed that uncovered W is susceptible of flowing water velocity. At high velocity w is easy to be eroded. For solid target design slab type and rod type targets were studied. As long as the optimized neutron performance is concerned, 1MW solid target is better than mercury target.

Disruption tests on repaired tungsten by CVD coating

Taniguchi, Masaki; Sato, Kazuyoshi; Ezato, Koichiro; Yokoyama, Kenji; Akiba, Masato

Journal of Nuclear Materials, 307-311(Part1), p.719 - 722, 2002/12

https://doi.org/10.1016/S0022-3115(02)01041-3

no abstracts in English

Coated fuel particle; Small particles for nuclear fuel

Minato, Kazuo

Zusetsu Zoryu; Tsubu No Sekai Arekore, p.131 - 133, 2001/10

no abstracts in English