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Yokomura, Ryota*; Goto, Masataka*; Yoshida, Takehito*; Warisawa, Shinichi*; Hanari, Toshihide; Kawabata, Kuniaki; Fukui, Rui*
IEEE Robotics and Automation Letters (Internet), 9(4), p.3275 - 3282, 2024/04
Times Cited Count:0To reduce errors in the remote control of robots during decommissioning, we developed a Rail DRAGON, which enables continuous observation of the work environment. The Rail DRAGON is constructed by assembling and pushing a long rail structure inside the primary containment vessel (PCV), and then repeatedly deploying several monitoring robots on the rails to enable constant observation in a high-radiation environment. In particular, we have developed the following components of Rail DRAGON: bendable rail modules, straight rail modules, a basement unit, and monitoring robots. Concretely, this research proposes and demonstrates a method to realize an ultralong articulated structure with high portability and workability. In addition, it proposes and verifies the feasibility of a method for deploying observation equipment that can be easily deployed and replaced, while considering disposal.
Takeuchi, Ryuji; Kokubu, Yoko; Nishio, Kazuhisa*
JAEA-Data/Code 2023-014, 118 Pages, 2024/02
The Tono Geoscience Center of Japan Atomic Energy Agency (JAEA) has been conducting the groundwater pressure and hydro-chemical monitoring to confirm the restoration process of the surrounding geological environment associated with the backfilling of shafts and tunnels of Mizunami Underground Research Laboratory (MIU). This report summarizes the data of the groundwater pressure and hydro-chemical monitoring from boreholes and forth at and around the MIU conducted in FY2022. In addition, unreported hydro-chemical monitoring data from the boreholes and forth at the MIU conducted in FY2021 were also compiled.
Takeuchi, Ryuji; Nishio, Kazuhisa*; Kokubu, Yoko
JAEA-Data/Code 2023-013, 74 Pages, 2024/01
The Tono Geoscience Center of Japan Atomic Energy Agency (JAEA) has been conducting the environmental monitoring investigation to confirm the environmental impacts associated with the backfilling of shafts and tunnels at the Mizunami Underground Research Laboratory (MIU). This report summarizes the results of the environmental impact investigations conducted as part of the environmental monitoring investigation around the MIU Site in FY2022, which include groundwater level measurement in wells, river flow rate measurement, water analysis of Hazama river, noise and vibration surveys, and soil survey.
Terada, Hiroaki
Ten Hasseigen Karano Mesosukeru Kakusan Shumireshon; Fukushima Daiichi Genshiryoku Hatsudensho Jiko O Fumaete (Kisho Kenkyu Noto Dai-248-Go), p.115 - 121, 2023/09
no abstracts in English
Takeuchi, Ryuji; Nishio, Kazuhisa*; Hanamuro, Takahiro; Kokubu, Yoko
JAEA-Data/Code 2022-010, 110 Pages, 2023/03
The Tono Geoscience Center of Japan Atomic Energy Agency (JAEA) has been conducting the environmental monitoring investigation to confirm the environmental impacts associated with the backfilling of shafts and tunnels at the Mizunami Underground Research Laboratory (MIU). This report summarizes the results of environmental impact investigations conducted as part of the environmental monitoring investigation around the MIU Site from FY2020 to FY2021, which include groundwater level measurement in wells, river flow rate measurement, water analysis of Hazama river, noise and vibration surveys, and soil survey.
Murakami, Hiroaki; Takeuchi, Ryuji; Iwatsuki, Teruki
JAEA-Technology 2022-022, 34 Pages, 2022/10
Japan Atomic Energy Agency (JAEA) has been conducting the hydro-pressure and hydrochemical monitoring for more than two decades to understand the hydrochemical disturbance due to the excavation of tunnels at Mizunami Underground Research Laboratory (MIU). To understand the environmental influence due to the backfilling of research tunnels that started in 2019, environmental monitoring of groundwater has been performed and recovery status of groundwater is being confirmed. In order to observe the deep-groundwater environment from the ground, the groundwater pressure monitoring and sampling, which have been performed in the research tunnel, are to be performed from the ground. However, backfilling of a large-scale underground facilities such as MIU is globally unprecedented, thus it was necessary to develop a new observation system. Accordingly, we developed a new observation network to observe the environment around the research tunnels of the MIU. This system enables monitoring of groundwater pressure and water sampling of the backfilled tunnel from the ground while utilizing the existing-monitoring system installed in the tunnels. Accordingly, we demonstrated its technology through the environmental monitoring of groundwater. The results of the environmental monitoring and the existing groundwater data of MIU indicate that this system is able to monitor the groundwater environment in the backfilled tunnels.
Saito, Kimiaki
Isotope News, (773), p.3 - 6, 2021/02
no abstracts in English
Uezu, Yasuhiro
Iwaki-Shi, Higashi Nihon Daishinsai Fukko Kiokushu, P. 37, 2021/00
This report describes the response to the Great East Japan Earthquake that occurred on March 11, 2011 from the perspectives of environmental monitoring, internal exposure evaluation, radiation education, and human resource development.
Sanada, Yukihisa
Isotope News, (772), p.21 - 25, 2020/12
no abstracts in English
Tamakuma, Yuki*; Yamada, Ryohei; Iwaoka, Kazuki*; Hosoda, Masahiro*; Tokonami, Shinji*
Hoken Butsuri (Internet), 54(1), p.5 - 12, 2019/03
Airborne radioactivity measurements are necessary to know the contamination level and internal doses for residents after a nuclear accident. In addition, measurements of radon progenies in air, which are the risk factor of lung cancer, are also important to evaluate lung dose. In these measurements, a filter sampling is used to collect radioactive aerosols. However, it is well known that results of the measurement using a filter are strongly dependent on characteristics of the used filter. Selection of a suitable filter is important to achieve the high-resolution and long-term measurement. "Surface collection efficiency (SCE)" and "stability of air flow rate" were examined for six types of filter that are commercially available in Japan. In Japan, cellulose-glass fiber filter paper (HE-40T) is used for an environmental monitoring in Japan. In this study, it was found that the SCE of HE-40T was lower than that of mixed cellulose ester type membrane filter by Merck Millipore (DAWP02500). Attenuation ratio of flow rate for DAWP02500 was evaluated to be 2.9% which was lowest in six filters. The results suggest that the DAWP02500 is the most suitable for collecting radioactive aerosols for a long term.
Saito, Hiroshi; Nozawa, Takashi; Takemiya, Hiroshi; Seki, Akiyuki; Matsubara, Takeshi; Saito, Kimiaki; Kitamura, Akihiro
JAEA-Review 2017-040, 34 Pages, 2018/03
The accidents at Fukushima Daiichi Nuclear Power Station on March 11th 2011, released significant amount of radionuclide to the environment. It has migrated to the human habitation and raised concerns of possible effect on human health, and for that a lot of researches have been performed. JAEA created and opened "Database for Radioactive Substance Monitoring Data" for usage of obtained data. For accurate modelling and future forecast using numerical code and the data, "Supporting Environment for Processing Simulation Codes" has been operated. In addition, research results have been opened as Q&A style "Knowledge Base for Environmental Remediation" in JAEA's website. The "Comprehensive Evaluation System" composed of these components, should act more interrelated and integrated as one system. Besides, information dissemination is not enough to the outside. The report summarizes the current status, remaining issues and expected improvement of each component and the system.
Nishimura, Tomohiro; Onuma, Toshimitsu*; Mizutani, Tomoko; Nakano, Masanao
JAEA-Technology 2017-019, 60 Pages, 2017/09
The meteorological observation has been performed since 1969's in the Nuclear Fuel Cycle Engineering Laboratories, JAEA after 1974. The meteorological observation data has been applied for the calculation of the atmospheric diffusion of radioactive wastes since the hot run was started 1977. This report presents statistical results of meteorological observation based on the decadal data from fiscal year 2005 to 2015. The characteristics of atmospheric diffusion related to the meteorological parameter are also discussed in this report.
Nagaoka, Mika; Matsubara, Natsumi; Fujita, Hiroki; Nakano, Masanao
KEK Proceedings 2016-8, p.134 - 138, 2016/10
no abstracts in English
Miyamura, Hiroko; Takemiya, Hiroshi; Wu, H.-Y.*; Takahashi, Shigeo*
Kashika Joho Gakkai-Shi, 36(143), p.152 - 156, 2016/10
Broad survey on the distribution of the air dose rate has been performed after the accident at the Fukushima Daiichi Nuclear Power Plant continuously. The surveyed monitoring datasets are stored in a database and are made available to the public. Recently, the size of the datasets have been significantly increased as more detailed measurements in space and time are available, and effective reduction of the size of the datasets is necessary for visualizing and exploring such large scale datasets. However, if the datasets are not carefully reduced, we often miss a part of important features of the distribution data. Therefore, we develop an effective Level of Detail control (LoD) method for retaining critical features of the distribution. In the method, the global and local features of the distribution are extracted by means of differential topology analyses. Then, the simplified data is created by edge collapse operation with taking into account these features of the data.
Miyahara, Kaname; Iijima, Kazuki; Saito, Kimiaki
Jiban Kogakkai-Shi, 63(11/12), p.62 - 69, 2015/11
This review provides a concise overview of knowledge and experience gained from the activities for environmental remediation after the Fukushima Dai-ichi accident as input for developing a technical knowledge base including remediation technologies which is translated into actions that enable the rapid return of evacuees. It is reflecting JAEA's key role in the research associated with both remediation of contaminated areas and the natural processes influencing contamination migration in non-remediated areas, working together with a number of Japanese and international organisations and research institutes. This review also provides a perspective on the future actions required to remediate areas outside the Fukushima Dai-ichi site.
Nagai, Haruyasu; Terada, Hiroaki; Chino, Masamichi; Katata, Genki; Mikami, Satoshi; Saito, Kimiaki
Proceedings of 16th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-16) (USB Flash Drive), p.4044 - 4052, 2015/08
JAEA has estimated the atmospheric releases of radionuclide during the Fukushima Daiichi Nuclear Power Station (FNPS1) accident by comparing measurements of air concentration of a radionuclide or its dose rate in the environment with the ones calculated by atmospheric transport and deposition model (ATDM). To improve our source term, we are trying to develop more sophisticated estimation method and use new information from severe accident analysis and observation data. As the first step of new trial, we used Cs/Cs ratios of inventories in FNPS1 reactors Unit 1 to 3 and those in surface deposition. By considering temporal change in Cs/Cs ratio of released plume and ATDM simulations, spatial distribution of Cs/Cs ratio in surface deposition was explained. This result can be used to specify from which reactor the dominant release occurred for each time period, and consequently provide useful information to severe accident analysis for the FNPS1 case.
Saito, Kimiaki; Onda, Yuichi*
Journal of Environmental Radioactivity, 139, p.240 - 249, 2015/01
Times Cited Count:53 Percentile:92.59(Environmental Sciences)no abstracts in English
Saito, Yoko
KURRI-KR-129, p.48 - 49, 2007/03
no abstracts in English
Maruo, Yoshihiro; ; Takeishi, Minoru; ; ; Takeyasu, Masanori;
JNC TN8440 2001-011, 146 Pages, 2001/06
Environmental radiation monitoring around the Tokai Reprocessing Plant has been performed since 1975, based on "Safety Regulations for the Tokai Reprocessing Plant, Chapter IV - Environmental Monitoring". This annual report presents the results of the environmental monitoring and the dose estimation to the hypothetical inhabitants due to the radioactivity discharged from the plant during April 2000 to March 2001. Appendices present comprehensive information, such as monitoring program, monitoring results, meteorological data and annual discharges from the plant.
Shinohara, Kunihiko; ; ; ; ; Kano, Yutaka;
JNC TN8440 2001-004, 62 Pages, 2001/02
Concerming about the action for the criticality accident in JCO Co., Ltd. (JCO) occurred at 10:35 on 30 Sept. 1999, Japan Nuclear Cycle Development Institute(JNC) established "JNC's task force" at 12:35 on the same date in conjuction with Head Office and Tokai Works. And JNC's task force had supported the government of Japan, the local governments and JCO humanly, physically and technically until the jobs of the task force was transferred to "Support Assembly for Countermeasure and Research of JCO Criticality Accident" and routine line on 12 Oct. 1999. This report compiled the results of the environmental monitoring performed by JNC based on the request from the government of Japan and the local governments.