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Kawabata, Kuniaki; Yashiro, Hiroshi*; Imabuchi, Takashi; Yokomura, Ryota*; Chen, B.*; Fukui, Rui*
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Sasaki, Miyuki; Ochi, Kotaro; Morishita, Yuki; Sanada, Yukihisa
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Hanari, Toshihide; Imabuchi, Takashi; Kawabata, Kuniaki
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This paper proposes to introduce a quantitative image quality assessment of 3D modeling to grasp the internal state of the nuclear reactor for the decommissioning of the Fukushima Daiichi Nuclear Power Station. We attempted to perform a feasibility investigation of a quantitative evaluation of image sequences as an index of 3D reconstruction accuracy. As a result, we confirmed that brightness and contrast parts in quantitative evaluation scores of image sequences were correlated with the reconstruction accuracy of 3D models.
Yamada, Taichi; Suzuki, Soichiro; Ito, Rintaro; Ota, Yua*; Kaneko, Eiichiro*; Ogane, Katsuji*; Kawabata, Kuniaki
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We develop evaluation methods for unmanned aircraft systems (UAS) in a narrow environment to boost industry. It is not easy to discuss what/much UAS users can do by using the UAS; furthermore, environmental influence makes it more complex. The evaluation method in this research aims to indicate UAS performances in an easy-to-understand form for UAS users and to push UAS use. The method evaluates a task's moving performance because moving is a critical function of UAS and is commonly required in many missions. Specifically, this paper introduces the evaluation method for ascending through a narrow aperture. In addition, this paper introduces an experiment to compare UAS performance by the aperture size.
Maekawa, Tomoyuki; Araki, Shohei; Aizawa, Eiju; Ishii, Junichi; Izawa, Kazuhiko
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Nakamura, Keita*; Noguchi, Kia*; Watanobe, Yutaka*; Imabuchi, Takashi; Hanari, Toshihide; Kawabata, Kuniaki
no journal, ,
During decommissioning work, movies are taken during surveys inside the primary containment vessel and the reactor building. By applying photogrammetry, a method of reconstructing 3D models from videos, it will be possible to reconstruct the environment around them in 3D. However, these videos were taken remotely and in dark environments, so they may not be suitable for conventional photogrammetry methods. Therefore, in this study, we compare a photogrammetric method based on a feature extraction method using deep learning that improves the accuracy of feature point matching with a conventional photogrammetric method. In this experiment, we mainly investigate the changes in the results of 3D reconstruction by photogrammetry when the lighting intensity and camera field of view are changed.
Matsueda, Makoto
no journal, ,
Radionuclide analysis by ICP-MS has a wide range of applications in the nuclear field, including nuclear forensics, waste management, health physics, environmental monitoring and radiometric dating. In recent years, with the progress of the decommissioning of the Fukushima Daiichi Nuclear Power Plant, the need for faster, more automated and more sophisticated radionuclide analysis has increased further. In this lecture, the latest analysis technologies under development at the Japan Atomic Energy Agency will be introduced, focusing on examples of automated and rapid systems combining ICP-MS with various separation mechanisms, especially for alpha- and beta-emitting radionuclides, which require time and labour-intensive measurements.
Yanagisawa, Kayo
no journal, ,
no abstracts in English
Araki, Shohei; Yoshikawa, Tomoki; Arakaki, Yu; Kamikawa, Yutaka; Hasegawa, Kenta; Tada, Yuta; Sumiya, Masato; Seki, Masakazu; Aizawa, Eiju; Ishii, Junichi; et al.
no journal, ,
In order to understand the criticality characteristics of the fuel debris generated by the accident at the Fukushima Daiichi Nuclear Power Plant, it is essential to obtain critical experiment data that includes reactor structural materials such as iron and concrete that are considered to be contained in the fuel debris. To gather such critical experiment data, JAEA had conducted a major modification of the critical assembly STACY, and the modified STACY achieved first criticality in March 2024. In this presentation, we will discuss the experiments conducted in the modified STACY, with a particular focus on iron, which is considered to have a significant impact on criticality safety due to its strong neutron absorption effect.
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radiation sources discrimination software using a 2d-imaging radiation detectorLaffolley, H.; Tsubota, Yoichi; Tsuji, Tomoya; Honda, Fumiya; Nitta, Ayako; Kikuchi, Riku
no journal, ,
In support of the decommissioning efforts at the Fukushima Daiichi Nuclear Power Station, the Japan Atomic Energy Agency (JAEA) is developing the TRACE software for the accurate discrimination of alpha, beta, and gamma radiation sources in radioactive samples. This new technology utilizes the MiniPIX, a commercial 2D imaging semiconductor radiation sensor. The MiniPIX provides both a spatial image of radiation interactions within its pixel matrix and quantification of the energy transferred. The TRACE software analyzes the data from the MiniPIX by examining the energy and shape of pixel clusters created by radiation events. It identifies alpha particles primarily through the higher energy transferred in their interactions. For other events, it extracts shape parameters: gamma particles, having a quasi-straight path, create very small pixel clusters, while beta particles, being more deviated, generate snake-like clusters. The software can also provide an energy spectrum split by radiation type to assist in identifying radioisotopes. A core component of TRACE is a machine learning algorithm, trained using data acquired from standard sources such as Cobalt-60, Strontium-90, Cesium-137, and Americium-241, chosen for their relevance to Fukushima samples. Planned future integration with an XYZ motorized stage aims to automate data acquisition, improve efficiency, facilitate handling of radioactive and non-flat samples, and enable real-time adjustment of acquisition duration.
Fujiwara, Takehiro*; Sakairi, Masatoshi*; Otani, Kyohei; Ueno, Fumiyoshi
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no abstracts in English
Hiraki, Yoshihisa; Sato, Junya; Chaerun, R. I.; Niu, X.*; Elakneswaran, Y.*; Yoshida, Yukihiko; Osugi, Takeshi
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Kanno, Ikuo
no journal, ,
no abstracts in English
Taniguchi, Takumi; Kuramochi, Ryo*; Hiraki, Yoshihisa; Shimizu, Koki; Osawa, Norihisa*; Kaneda, Yoshihisa*; Yoshida, Yukihiko; Osugi, Takeshi
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Tatsuno, Takahiro*; Nihei, Naoto*; Yoshimura, Kazuya; Ote, Nobuhito*
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Kawabata, Kuniaki; Okada, Satoshi*; Yoshimi, Takashi*
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