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Machida, Masahiko; Yamada, Susumu; Kim, M.; Okumura, Masahiko; Miyamura, Hiroko; Shikaze, Yoshiaki; Sato, Tomoki*; Numata, Yoshiaki*; Tobita, Yasuhiro*; Yamaguchi, Takashi; et al.
RIST News, (69), p.2 - 18, 2023/09
The contamination of radioactive materials leaked from the reactor has resulted in numerous hot spots in the Fukushima Daiichi Nuclear Power Station (1F) building, posing obstacles to its decommissioning. In order to solve this problem, JAEA has conducted research and development of the digital technique for inverse estimation of radiation source distribution and countermeasures against the estimated source in virtual space for two years from 2021 based on the subsidy program "Project of Decommissioning and Contaminated Water Management" performed by the funds from the Ministry of Economy, Trade and Industry. In this article, we introduce the results of the project and the plan of the renewal project started in April 2023. For the former project, we report the derivative method for LASSO method considering the complex structure inside the building and the character of the source and show the result of the inverse estimation using the method in the real reactor building. Moreover, we explain the platform software "3D-ADRES-Indoor" which integrates these achievements. Finally, we introduce the plan of the latter project.
Yamane, Yuichi; Numata, Yoshiaki*; Tonoike, Kotaro
Proceedings of 11th International Conference on Nuclear Criticality Safety (ICNC 2019) (Internet), 10 Pages, 2019/09
For the criticality safety of the operation treating the fuel debris in Fukushima Daiichi Nuclear Power Plant, the reactivity effect of its geometrical change has been investigated and the developed procedure has been applied to a trial analysis of a postulated scenario for the purpose of its verification.
Torata, Shinichiro; Numata, Yoshiaki; Kawase, Keiichi; Manabe, Tatefumi
JAEA-Review 2009-024, 12 Pages, 2009/09
JAEA-Review-2009-024.pdf:1.26MB
To continue utilizing nuclear energy in the future, a key issue still remains concerned with the public's perception of generating radioactive waste and its subsequent safe disposal. Despite undertaking long term research and development to implement a program of geological disposal of radioactive waste, the social recognition and public understanding is still insufficient. Consequently, JAEA has been trying to extend the public's scientific understanding by showing its research facilities. In this report, the content of more than 1000 answer sheets have been analyzed from members of the public who visited the JAEA research facilities. Several important findings were obtained, in particular, notable differences were found in the answers of those who had also visited an underground tunnel compared with those who had not. This and other findings are significant in promoting the social recognition of the ongoing research and development of the geological disposal of radioactive waste.
Sasaki, Yasuo; Torata, Shinichiro; Numata, Yoshiaki
JAEA-Review 2008-078, 51 Pages, 2009/03
JAEA-Review-2008-078.pdf:5.57MB
JAEA organizes the "Technical Committee for Geological Isolation Research & Development", which consists of specialists in relevant fields at universities and institutes, in order to facilitate planning and conducting of a program of research and development (R&D) for geological disposal of high-level radioactive waste and TRU waste at JAEA-Tokai, through reflecting technical advices and comments made from them into the program. This report presents the minutes of the third meeting held in March 2008.
Sasaki, Yasuo; Numata, Yoshiaki; Torata, Shinichiro
JAEA-Review 2008-068, 23 Pages, 2009/02
JAEA-Review-2008-068.pdf:2.73MB
The nuclear waste disposal is still in discussion as one of the key issue while we continue the sustainable atomic energy use, and it has been taking with much of the viewpoint of the social acceptance. In addition it may be said that it is the problem that the long term necessity to promote the disposal arise the subjects of the security of people who take charge of the disposal project. Also the management of knowledge with technical information between generations would become another subject in the future. To find the way out of these concerns, the practices having been tryed by the researcher group towards the student generation are reviewed in this report. The results of the opinion exchange and scientific communication with the people in the educational institution by the disposal research scientists are reviewed based on the questionnaire and discussion at a practice of schooling and lecture at high schools and universities.
Sasaki, Yasuo; Torata, Shinichiro; Numata, Yoshiaki
JAEA-Review 2008-016, 69 Pages, 2008/03
JAEA-Review-2008-016.pdf:7.79MB
In order to plan and conduct a program of research and development (R&D) for geological disposal of high-level radioactive waste in JAEA-Tokai, JAEA decided to receive technical comments and advices from the Technical Committee for geological isolation R&D. This committee, which is constituted of specialists who do not belong to JAEA, has evaluated the program, taking into account of the status of geological disposal technology in Japan as well as foreign countries. This report compiles the minutes of the second meeting held in March 2007.
Yamada, Susumu; Numata, Yoshiaki*; Sato, Tomoki*; Tobita, Yasuhiro*; Wei, S.*
no journal, ,
no abstracts in English
Miyamura, Hiroko; Sato, Tomoki*; Numata, Yoshiaki*; Tobita, Yasuhiro*; Machida, Masahiko
no journal, ,
We develop interactive visualization engine on a mixed reality device to realize workers' safety and work efficiency during environmental improvement work under the high-dose radiation environment. After the inverse source estimation, the three-dimensional distribution maps of the air dose rate are obtained by simulation. It is necessary to present the maps to decommissioning workers by visualization techniques to help them understand their environment. The latest MR devices can be used to support the work of decommissioning workers by placing virtual visualization primitives in the real space. In this presentation, we report outline the results and future direction of the MR device visualization engine, including features such as immersive experience, interactive operation, and information sharing with remote specialists.
Machida, Masahiko; Shi, W.*; Yamada, Susumu; Miyamura, Hiroko; Numata, Yoshiaki*; Sato, Tomoki*; Tobita, Yasuhiro*; Yoshida, Toru*; Yanagi, Hideaki*; Furutachi, Naoya*; et al.
no journal, ,
no abstracts in English
Miyamura, Hiroko; Sato, Tomoki*; Numata, Yoshiaki*; Tobita, Yasuhiro*; Iwata, Ayako*; Machida, Masahiko
no journal, ,
We propose a prototype of a decommissioning support system using an XR device, considering the system is effective for realizing the safety for the decommissioning workers the efficiency of the work. In this paper, we report the outline of the new function as we have added it with the use of Avatar in cyberspace for evaluating the exposure dose of the decommissioning workers. This function allows to create the work plan which is taken into account the worker's exposure dose rate.
