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Takaku, Yuhi; Kakefuda, Toyokazu*; Yashiro, Shigeo; Kimura, Hideo; Kuno, Tetsuya
JAEA-Testing 2024-006, 31 Pages, 2025/03
JAEA-Testing-2024-006.pdf:2.5MB
The Japan Atomic Energy Agency (JAEA) has a wide variety of servers across its departments, managed by on-site server administrators who are responsible for tasks including security measures. As a result, the workload and operational cost burdens are significant. Additionally, addressing the increasing frequency of security incidents in recent years, both domestically and internationally, is essential for JAEA's operations, which involve handling sensitive information. However, it is difficult for individual server administrators to take proactive measures to mitigate these risks. To address these challenges, we carried out the migration of systems that do not contain sensitive information to an external cloud environment with a focus on cost reduction. As a result, we clarified the conditions necessary for a smooth migration to an external cloud environment while achieving significant cost savings and established a foundation for implementing measures against security incidents.
Terada, Hiroaki; Nagai, Haruyasu; Tsuzuki, Katsunori; Furuno, Akiko; Kadowaki, Masanao; Kakefuda, Toyokazu*
Journal of Environmental Radioactivity, 213, p.106104_1 - 106104_13, 2020/03
Times Cited Count：65 Percentile：92.79(Environmental Sciences)In order to assess the radiological dose to the public resulting from the Fukushima Daiichi Nuclear Power Station accident in Japan, the spatial and temporal distribution of radioactive materials in the environment is necessary to be reconstructed by computer simulations with the atmospheric transport, dispersion and deposition model (ATDM) and source term of radioactive materials discharged into the atmosphere is essential. In this study, we carried out refinement of the source term and improvement of ATDM simulation by using an optimization method based on Bayesian inference with various measurements (air concentration, surface deposition, and fallout). We also constructed the spatiotemporal distribution of some major radionuclides in the air and on the surface (optimized dispersion database) by using the optimized release rates and ATDM simulations which is used for the comprehensive dose assessment by coupling with the behavioral pattern of evacuees from the accident.
Nakanishi, Chika; Sato, Takeshi; Sato, Sohei; Nagai, Haruyasu; Kakefuda, Toyokazu; Katata, Genki; Tsuzuki, Katsunori; Ikeda, Takeshi; Okuno, Hiroshi; Yamamoto, Kazuya; et al.
JAEA-Technology 2013-030, 105 Pages, 2013/10
JAEA-Technology-2013-030.pdf:29.0MB
North Korea carried out the third nuclear test in February 2013. Due to the request of the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Nuclear Emergency Assistance and Training Center (NEAT) and Nuclear Science and Engineering Directorate (NSED) of JAEA predicted the atmospheric dispersion of radionuclide by WSPEEDI-II for the purpose of contributing to the environmental monitoring plan. From February 12 to 22, they provided daily reports on the prediction to the MEXT and the Ministry of Defense. MEXT has published these reports on the website. Since April 2012, NEAT and NSED had prepared to predict by the framework for the prediction around the clock during 10months until February 2013. This report described this experience and pointed issues out on this system.
Terada, Hiroaki; Nagai, Haruyasu; Furuno, Akiko; Kakefuda, Toyokazu; Harayama, Takaya*; Chino, Masamichi
Nihon Genshiryoku Gakkai Wabun Rombunshi, 7(3), p.257 - 267, 2008/09
The second version of WSPEEDI (WSPEEDI-II) which has functions to predict the radiological impact of nuclear accident abroad on Japan by quick calculations of air concentration, surface deposition and radiological doses is developed. WSPEEDI-II has the following functions for practical use. (1) High performance prediction of atmospheric dispersion of radionuclides from local to regional ranges with appropriate resolutions by introducing non-hydrostatic atmospheric dynamic model. (2) Source term estimation by coupling calculation results and monitoring data for the case that no source information is available from abroad. (3) On-line prediction data exchanges with major emergency response systems in the United States and Europe with the similar functions as WSPEEDI-II. (4) Web-based graphical user interface system for easy operation of WSPEEDI-II. (5) Preset East-Asian database for the quick start against a nuclear accident in Eastern Asia. This paper describes these new functions.
Hoshi, Y.*; Miura, Yushi; Ouchi, K.*; Kakefuda, Toyokazu*; Akiba, K.*; ; Kawamata, Yoichi; Kurihara, Kenichi
Heisei-12-Nendo Tohoku Daigaku Gijutsu Kenkyukai Hokoku, p.425 - 427, 2001/03
no abstracts in English
Nagai, Haruyasu; Terada, Hiroaki; Tsuzuki, Katsunori; Furuno, Akiko; Kadowaki, Masanao; Kakefuda, Toyokazu*
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no abstracts in English
Nagai, Haruyasu; Katata, Genki; Ota, Masakazu; Ina, Takuya; Kakefuda, Toyokazu; Endo, Akira
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Nagai, Haruyasu; Katata, Genki; Ota, Masakazu; Ina, Takuya; Kakefuda, Toyokazu; Endo, Akira
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no abstracts in English
