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Terasaka, Yuta; Iimoto, Takeshi*; Saso, Michitaka*; Fujita, Reiko*
Nihon Genshiryoku Gakkai-Shi ATOMO, 66(4), p.203 - 207, 2024/04
no abstracts in English
Terada, Hiroaki; Nagai, Haruyasu; Kadowaki, Masanao; Tsuzuki, Katsunori
Journal of Nuclear Science and Technology, 60(8), p.980 - 1001, 2023/08
Times Cited Count:4 Percentile:97.05(Nuclear Science & Technology)It is essential to establish a method for reconstructing the source term and spatiotemporal distribution of radionuclides released into the atmosphere due to a nuclear accident for emergency countermeasures. We examined the dependency of a source term estimation method based on Bayesian inference using atmospheric dispersion simulation and environmental monitoring data on the availability of various monitoring data. Additionally, we examined the applicability of this method to a real-time estimation conducted immediately after an accident. A sensitivity analysis of the estimated source term during the Fukushima Daiichi Nuclear Power Station (FDNPS) accident for combinations of various monitoring data indicated that using monitoring data with a high temporal and spatial resolution and the concurrent use of air concentration and surface deposition data is effective for accurate estimation. A real-time source term estimation experiment assuming the situation of monitoring data acquisition during the FDNPS accident revealed that this method could provide the necessary source term for grasping the overview of surface contamination in the early phase and evaluating the approximate accident scale. If the immediate online acquisition of monitoring data and regular operation of an atmospheric dispersion simulation are established, this method can provide the source term in near-real time.
Nakano, Masanao
Hoken Butsuri (Internet), 56(1), p.17 - 25, 2021/03
The Tokai Reprocessing Plant is the first reprocessing plant in Japan which started hot test in 1977, and had reprocessed 1140 tons of spent nuclear fuel by May 2007. The gaseous and liquid radioactive wastes has been discharged to the environment. Since iodine-129 (I) is one of the most important nuclides for environmental impact assessment. Therefore, I in the exhaust and effluent has been controlled, and a precise analysis method of I in the environmental samples was developed, and the concentration of 129I in the environment was investigated. This report presents an overview of these activities. Not limited to I on reprocessing facilities, it is essential for nuclear operators to reduce the amount released to the environment in the spirit of ALARA, and to continuously develop the further upgrading environmental monitoring methods and evaluation methods in order to foster a sense of safety and security among residents living in the vicinity of the facilities.
Malins, A.; Ochi, Kotaro; Machida, Masahiko; Sanada, Yukihisa
Proceedings of Joint International Conference on Supercomputing in Nuclear Applications + Monte Carlo 2020 (SNA + MC 2020), p.147 - 154, 2020/10
Nakano, Masanao; Hosomi, Kenji; Nishimura, Shusaku; Matsubara, Natsumi; Okura, Takehisa; Kuramochi, Akihiko; Kawasaki, Masatsugu; Takeuchi, Erina; Fujii, Yutaka*; Jinno, Tsukasa*; et al.
Hoken Butsuri (Internet), 55(2), p.102 - 109, 2020/06
After the Fukushima-Daiichi Nuclear Power Station (1F) Accident in March 2011, the increase was significantly observed in a part of the result of the environmental radiation monitoring in Ibaraki prefecture. "The review meeting of the environmental effect from 1F accident" was established to discuss technically the fluctuation of monitoring data. The review meeting collected the monitoring data from the four nuclear operators, and discussed a fluctuating trend, Cs/Cs activity ratio, and so on. In this report, the results of the dose rate and Cs in fallout, surface soil, flatfish and seabed sediment are introduced. Also the problem solving in the review meeting is introduced.
Saito, Kimiaki; Mikami, Satoshi; Ando, Masaki; Matsuda, Norihiro; Kinase, Sakae; Tsuda, Shuichi; Sato, Tetsuro*; Seki, Akiyuki; Sanada, Yukihisa; Wainwright-Murakami, Haruko*; et al.
Journal of Radiation Protection and Research, 44(4), p.128 - 148, 2019/12
Chino, Masamichi*; Nagai, Haruyasu
Environmental Contamination from the Fukushima Nuclear Disaster; Dispersion, Monitoring, Mitigation and Lessons Learned, p.50 - 61, 2019/00
Times Cited Count:8 Percentile:82.45(Environmental Sciences)Temporal variations in the amount of radionuclides released into the atmosphere during the Fukushima Daiichi Nuclear Power Station accident and their atmospheric dispersion are essential to evaluate the environmental impacts and resultant radiological doses to the public. We have estimated the atmospheric releases during the accident by comparing measurements with calculations by atmospheric deposition model. UNSCEAR compared several estimated source terms and used our source term for estimating levels of radioactive material in the terrestrial environment and doses to the public. To improve our source term, we recently made detailed source term estimation by using additional monitoring data and WSPEEDI including new deposition scheme.
Shobu, Nobuhiro
Enerugi Rebyu, 37(10), p.21 - 22, 2017/10
After the Fukushima-Daiichi Nuclear Power Plant Accident, Japan Atomic Energy Agency (JAEA) has been carrying out research and development activities towards the environmental restoration of Fukushima. This paper describes the following representative activities in Fukushima Environmental Safety Center of JAEA, such as the development of environmental monitoring and mapping technologies, the long-term assessment of transport of radio-cesium in the environment of Fukushima, and the technology development for advancing decontamination and volume reduction technologies.
Hidaka, Akihide; Yokoyama, Hiroya
Proceedings of Symposium on Water Chemistry and Corrosion in Nuclear Power Plants in Asia 2017 (AWC 2017) (USB Flash Drive), p.29 - 42, 2017/09
no abstracts in English
Miyahara, Kaname; Ohara, Toshimasa*
Nihon Genshiryoku Gakkai-Shi ATOMO, 59(5), p.282 - 286, 2017/05
This review highlights JAEA and NIES's challenges for enhancing Fukushima environmental resilience based on carrying out multifaceted research working with many public and private sector organizations and academia.
Ohara, Toshimasa*; Miyahara, Kaname
Global Environmental Research (Internet), 20(1&2), p.3 - 13, 2017/03
Toward the environmental regeneration in Fukushima Prefecture and other areas after the Fukushima Daiichi Nuclear Power Station accidents, JAEA and NIES working with many public and private sector organizations and academia have carried out multifaceted research that will help to restore the environment of affected areas. These challenging efforts need to be further strengthened.
Hirouchi, Jun; Okura, Takehisa; Satoh, Daiki
Nihon Genshiryoku Gakkai-Shi ATOMO, 59(3), p.152 - 155, 2017/03
no abstracts in English
Chino, Masamichi; Terada, Hiroaki; Nagai, Haruyasu; Katata, Genki; Mikami, Satoshi; Torii, Tatsuo; Saito, Kimiaki; Nishizawa, Yukiyasu
Scientific Reports (Internet), 6, p.31376_1 - 31376_14, 2016/08
Times Cited Count:57 Percentile:98.61(Multidisciplinary Sciences)Department of Health Physics; Safety Division, Naka; Safety Division, Takasaki; Radiation Control Division, Oarai; Safety Division, Kansai; Operation Safety Administration Division, Mutsu
JAERI-Review 2005-028, 232 Pages, 2005/08
no abstracts in English
Department of Health Physics; Safety Division, Naka; Safety Division, Takasaki; Radiation Control Division, Oarai; Safety Division, Kansai; Operation Safety Administration Division, Mutsu
JAERI-Review 2004-024, 209 Pages, 2004/11
no abstracts in English
Department of Health Physics; Safety Division, Naka; Safety Division, Takasaki; Radiation Control Division, Oarai; Safety Division, Kansai; Operation Safety Administration Division, Mutsu
JAERI-Review 2003-034, 208 Pages, 2003/11
no abstracts in English
Saito, Yoko; Miyamoto, Yutaka; Magara, Masaaki; Sakurai, Satoshi; Usuda, Shigekazu
Journal of Radioanalytical and Nuclear Chemistry, 255(2), p.341 - 345, 2003/02
Times Cited Count:4 Percentile:31.59(Chemistry, Analytical)no abstracts in English
Department of Health Physics; Safety Division, Naka; Safety Division, Takasaki; Radiation Control Division, Oarai; Safety Division, Kansai; Operation Safety Administration Division, Mutsu
JAERI-Review 2002-036, 219 Pages, 2002/12
no abstracts in English
Department of Health Physics; Safety Division, Naka; Safety Division, Takasaki; Radiation Control Division, Oarai; Safety Division, Kansai; Operation Safety Administration Division, Mutsu
JAERI-Review 2001-041, 221 Pages, 2001/12
no abstracts in English
Department of Health Physics; Safety Division, Naka; Safety Division, Takasaki; Radiation Control Division, Oarai; Safety Division, Kansai; Operation Safety Administration Division, Mutsu
JAERI-Review 2001-007, 213 Pages, 2001/03
no abstracts in English