R&D status of digital technology on inverse estimation of radioactive source distributions and related source countermeasures; Fast Digital Twin Tech. in Decommissioning Field: 3D-ADRES-Indoor FrontEnd

Machida, Masahiko; Yamada, Susumu; Kim, M.; Tanaka, Satoshi*; Tobita, Yasuhiro*; Iwata, Ayako*; Aoki, Yuto; Aoki, Kazuhisa; Yanagisawa, Kenichi*; Yamaguchi, Takashi; et al.

RIST News, (70), p.3 - 22, 2024/09

Inside the Fukushima Daiichi Nuclear Power Plant (1F), there are many locations with high radiation levels due to contamination by radioactive materials that leaked from the reactor. These pose a significant obstacle to the smooth progress of decommissioning work. To help solve this issue, the Japan Atomic Energy Agency (JAEA), under a subsidy from the Ministry of Economy, Trade, and Industry's decommissioning and contaminated water management project, is conducting research and development on digital technologies to improve the radiation environment inside the decommissioning site. This project, titled "Development of Technology to Improve the Environment Inside Reactor Buildings (Enhancing Digital Technology for Environment and Source Distribution to Reduce Radiation Exposure)," began in April of FY 2023. In this project, the aim is to develop three interconnected systems: FrontEnd, Pro, and BackEnd. The FrontEnd system, based on the previously developed 3D-ADRES-Indoor (prototype) from FY 2021-2022, will be upgraded to a high-speed digital twin technology usable on-site. The Pro system will carry out detailed analysis in rooms such as the new office building at 1F, while the BackEnd system will serve as a database to centrally manage the collected and analyzed data. This report focuses on the FrontEnd system, which will be used on-site. After point cloud measurement, the system will quickly create a 3D mesh model, estimate the radiation source from dose rate measurements, and refine the position and intensity of the estimated source using recalculation techniques (re-observation instructions and re-estimation). The results of verification tests conducted on Unit 5 are also presented. Furthermore, the report briefly discusses the future research and development plans for this project.

LASSO reconstruction scheme to predict radioactive source distributions inside reactor building rooms; Practical applications

Machida, Masahiko; Shi, W.*; Yamada, Susumu; Miyamura, Hiroko; Yoshida, Toru*; Hasegawa, Yukihiro*; Okamoto, Koji; Aoki, Yuto; Ito, Rintaro; Yamaguchi, Takashi; et al.

Proceedings of Waste Management Symposia 2023 (WM2023) (Internet), 11 Pages, 2023/02

Development of performance evaluation method for small UAV flight in narrow space

Yamada, Taichi; Aoki, Yuto; Suzuki, Soichiro; Ito, Rintaro; Kawabata, Kuniaki

no journal, , 

This paper introduces a development of evaluation methods for flight performance of small unmanned aerial vehicle (UAV) in narrow space environments. Drone use in a narrow space is expected to provide many solutions for society, such as an inspection of plant equipment or house surveying after disaster and so on. While, in a narrow space, drone performance is restricted, for example, there are obstacles, GNSS (Global Navigation Satellite System) is denied, and it is difficult to discuss the performance of drone. Thus, the aim of the evaluation methods is to describe a drone flight performance in an easy-to-understand form, for industrial boosting. This paper explains the approach of our evaluation method and how to proceed with the development while incorporating opinions from drone users and providers. In addition, this paper describes prototypes of evaluation method for observation of obstacles, and a preliminary experiment to discuss the need of evaluation method for observation of obstacles for narrow space drone flight.

LASSO reconstruction scheme to predict radioactive source distributions inside reactor building rooms; Outline of R&D project

Suzuki, Masahiro; Aoki, Yuto; Machida, Masahiko; Ito, Rintaro; Kawabata, Kuniaki; Yamaguchi, Takashi; Okamoto, Koji

no journal, , 

Development of exposure reduction technologies by digitalization of environment and radioactive source distribution, 6; Computational method validation and effectiveness evaluation of an estimation system of radiation sources and dose rates

Aoki, Yuto; Ito, Rintaro; Kitamura, Akihiro; Omori, Takazumi; Taniguchi, Tatsuro; Ide, Hiroshi

no journal, , 

In this report, we present the validation results of the radiation source inverse estimation computation method and the effectiveness evaluation method of the "estimation system of radiation sources and dose rates" developed by JAEA. As for the validation test, the JMTR was used as the evaluation site, and the results of radiation source inverse estimation computations were compared with measured data. As a result, it was confirmed that the hot spot could be estimated approximately well. As for the effectiveness evaluation, the test field to be established at the NARREC and at the JMTR were used as the evaluation sites, and the effectiveness evaluation items such as the functions of each tool and the process of the system were summarized.

Development of test methods for small UAS mobility evaluation in a narrow space

Yamada, Taichi; Aoki, Yuto; Suzuki, Soichiro; Ito, Rintaro; Kawabata, Kuniaki

no journal, , 

We develop test methods for Unmanned Aircraft System (UAS) mobility evaluation in a narrow space. This development aims to provide an easy-to-understand evaluation for people without technical knowledge, such as UAS users, and to boost the UAS industry. To indicate UAS performance in an easy-to-understand, the test methods in this research evaluate how much the UAS can do the task based on actually performing the test task in the test field. In addition, the test methods have variable environmental factors that dominate the task performance to discuss the UAS's environmental applicability for facilitating UAS usage scenario expansion. Because accepting the test methods for UAS users and manufacturers is essential for boosting the industry, this development is proceeding while discussing with UAS users and manufacturers. This paper introduces the development of a test method for evaluating UAS mobility for ascending through an aperture.