Radiation imaging of a highly contaminated filter train inside Fukushima Daiichi Nuclear Power Station Unit 2 using an integrated Radiation Imaging System based on a Compton camera

Sato, Yuki; Terasaka, Yuta

Journal of Nuclear Science and Technology, 60(8), p.1013 - 1026, 2023/08

https://doi.org/10.1080/00223131.2022.2159894

Radiation imaging using an integrated radiation imaging system based on a compact Compton camera under Unit 1/2 exhaust stack of Fukushima Daiichi Nuclear Power Station

Sato, Yuki; Terasaka, Yuta

Journal of Nuclear Science and Technology, 59(6), p.677 - 687, 2022/06

https://doi.org/10.1080/00223131.2021.2001391

Quantitative analysis of radioactivity distribution by imaging of high radiation field environment using gamma-ray imaging spectroscopy (Contract research); FY2019 Nuclear Energy Science & Technology and Human Resource Development Project

Collaborative Laboratories for Advanced Decommissioning Science; Kyoto University*

JAEA-Review 2020-044, 79 Pages, 2021/01

JAEA-Review-2020-044.pdf:4.39MB

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 "Quantitative analysis of radioactivity distribution by imaging of high radiation field environment using gamma-ray imaging spectroscopy" Conducted in FY2019. In this study, a gamma-ray imaging detector, ETCC, will be improved to operate under high dose conditions, and a portable system will be constructed to be installed in the Fukushima Daiichi Nuclear PowerStation (1F). In addition, the development and combination of ETCC-based quantitative radioactivity distribution analysis methods will lead to innovative advances in the six key issues to be solved for the decommissioning of the 1F. This system will enable us to quantitatively visualize the three-dimensional radiation distribution and its origin.

Remote detection of radioactive hotspot using a Compton camera mounted on a moving multi-copter drone above a contaminated area in Fukushima

Sato, Yuki; Ozawa, Shingo*; Terasaka, Yuta; Minemoto, Kojiro*; Tamura, Satoshi*; Shingu, Kazutoshi*; Nemoto, Makoto*; Torii, Tatsuo

Journal of Nuclear Science and Technology, 57(6), p.734 - 744, 2020/06

https://doi.org/10.1080/00223131.2020.1720845

Quantitative analysis method for radiation distribution in high radiation environment by gamma-ray image spectroscopy (Contract research); FY2018 Center of World Intelligence Project for Nuclear Science/Technology and Human Resource Development

Collaborative Laboratories for Advanced Decommissioning Science; Kyoto University*

JAEA-Review 2019-036, 65 Pages, 2020/03

JAEA-Review-2019-036.pdf:4.46MB

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 "Quantitative Analysis Method for Radiation Distribution in High Radiation Environment by Gamma-ray Image Spectroscopy". Electron-tracking Compton camera (ETCC) has been developed originally for nuclear gamma-ray astronomy, and also applied to medical use as a technology that greatly improves the resolution of conventional Compton camera by measuring three-dimensional tracking of electrons using a gaseous 3-dimensional position detector (so called Time Projection Chamber) in the first stage. In the present study, based on the ETCC that has been developed for medical use, we produce a prototype of light weight ETCC with the emphasis on the operability at the site, and evaluate its practicability by field tests.

Electron-tracking Compton camera imaging of technetium-95m

Hatsukawa, Yuichi*; Hayakawa, Takehito*; Tsukada, Kazuaki; Hashimoto, Kazuyuki*; Sato, Tetsuya; Asai, Masato; Toyoshima, Atsushi; Tanimori, Toru*; Sonoda, Shinya*; Kabuki, Shigeto*; et al.

PLOS ONE (Internet), 13(12), p.e0208909_1 - e0208909_12, 2018/12

AA2018-0639.pdf:2.39MB

https://doi.org/10.1371/journal.pone.0208909

Imaging of Tc radioisotope was conducted using an electron tracking-Compton camera (ETCC). Tc emits 204, 582, and 835 keV rays, and was produced in the Mo(p,n)Tc reaction with a Mo-enriched target. The recycling of the Mo-enriched molybdenum trioxide was investigated, and the recycled yield of Mo was achieved to be 70% - 90%. The images were obtained with each of the three rays. Results showed that the spatial resolution increases with increasing -ray energy, and suggested that the ETCC with high-energy -ray emitters such as Tc is useful for the medical imaging of deep tissue and organs in the human body.

Radiation imaging using a compact Compton camera inside the Fukushima Daiichi Nuclear Power Station building

Sato, Yuki; Tanifuji, Yuta; Terasaka, Yuta; Usami, Hiroshi; Kaburagi, Masaaki; Kawabata, Kuniaki; Utsugi, Wataru*; Kikuchi, Hiroyuki*; Takahira, Shiro*; Torii, Tatsuo

Journal of Nuclear Science and Technology, 55(9), p.965 - 970, 2018/09

https://doi.org/10.1080/00223131.2018.1473171

Development of compact Compton camera for 3D image reconstruction of radioactive contamination

Sato, Yuki; Terasaka, Yuta; Ozawa, Shingo*; Miyamura, Hiroko; Kaburagi, Masaaki; Tanifuji, Yuta; Kawabata, Kuniaki; Torii, Tatsuo

Journal of Instrumentation (Internet), 12(11), p.C11007_1 - C11007_8, 2017/11

https://doi.org/10.1088/1748-0221/12/11/C11007

Compact Compton camera for radiation distribution imaging under high dose rate environments

Sato, Yuki; Terasaka, Yuta; Kaburagi, Masaaki; Tanifuji, Yuta; Usami, Hiroshi; Miyamura, Hiroko; Ozawa, Shingo*; Izumi, Ryo*; Kawabata, Kuniaki; Suzuki, Toshikazu*; et al.

no journal, , 

Visualization of radioactive substances on a 3D building model of the Fukushima Daiichi Nuclear Power Station

Sato, Yuki; Terasaka, Yuta; Utsugi, Wataru*; Kikuchi, Hiroyuki*; Takahira, Shiro*; Torii, Tatsuo

no journal, ,