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Hokama, Tomonori; Fujita, Hiroki; Nakano, Masanao; Iimoto, Takeshi*
Radiation Protection Dosimetry, 196(3-4), p.136 - 140, 2021/11
Times Cited Count：0 Percentile：0.01(Environmental Sciences)During the early phase of a nuclear accident, major radioactive materials are released into the environment, necessitating the prompt deployment of various protective actions to avoid or reduce radiation exposure. To implement these actions, the levels of radioactivity in the environment should be determined. However, the radioactivity concentrations of artificial alpha-particle-emitting radionuclides such as plutonium are difficult to measure in airborne samples, because they are interfered with natural radionuclides such as uranium decay products. Therefore, chemical separation is required to measure the concentrations. This study presents a new emergency monitoring system for airborne samples, which performs multiple-pulse time-interval analysis (MTA) without chemical separation. The system is used in conjunction with an alpha/beta-particle survey meter and adopted an analysis method focusing on the detected time interval of each particle. Its features are that a short time to output measurement result, easy handling and nondestructive. The estimated detection limit of the system was 9.5
10
Bq m
. The MTA-based monitoring system could be useful in situations requiring prompt measurement and screening of samples.
Takeishi, Minoru
JAEA-Review 2020-077, 388 Pages, 2021/05
JAEA-Review-2020-077.pdf:18.48MB
Japan Atomic Energy Agency (JAEA) have implemented environmental radiation monitoring since 1960s around different kinds of nuclear facilities such as research reactors, MOX fuel fabrication development facilities and the first spent fuel reprocessing facility for commercial NPPs and so on. I summarize the environmental monitoring methodology from planning to evaluation comprehensively as a guide book based on our experience and referring to the latest information. This guide book contained various basic knowledge about history of environmental radiation surveillances, techniques of radiation measurement and analysis of environmental samples such as airborne materials, precipitation, fallout, soil, sediment in river and lake, drinking water, terrestrial water, vegetables, milk, pasture, sea water, seabed sediment, marine product, index samples, and including with related to fundamental knowledges like an exposure evaluation for the public and quality assurance(QA), and some regulations. In particular, I include the emergency environmental radiation monitoring with response to the accident of Chernobyl Nuclear Power Plant and Tokyo Electric Power Company Fukushima Daiichi Nuclear Power Station. Finally, I note some topics on the environmental impact study that I have experienced.
Fujiwara, Kenso; Yanagisawa, Kayo*; Iijima, Kazuki
Environmental Radiochemical Analysis VI, p.89 - 96, 2019/09
Since Strontium-90 (Sr-90) is one of the high yield and hazardous fission products, accurate and low-level detection of Sr-90 is essential for environmental samples. Especially, in case of nuclear power plant accidents, rapid and precise assessment of Sr-90 for environmental monitoring and health physics is required. In order to evaluate the migration of radionuclides in the environment, not only Sr-90 in water but also those in soil and biological samples should be measured. A new method for rapid quantification of Sr-90 by online solid phase extraction coupled with inductively coupled plasma mass spectrometry (SPE-ICP-MS) has been developed. In this method, it is unavoidable to eliminate the interference by polyatomic ion (e.g., ArCa, Ca
) induced by isotopes and matrices in fishes and soil. In this study, SPE-ICP-MS method was applied to the measurement of Sr-90 in fishes, and the influence of the Sr isotopes and coexisting ions such as Ca was evaluated.
;
Genshiryoku Kogyo, 27(7), p.22 - 26, 1981/00
no abstracts in English
Yamada, Junya; Seya, Natsumi; Haba, Risa; Muto, Yasunobu; Hashimoto, Makoto; Shimizu, Takehiko; Takasaki, Koji; Yokoyama, Sumi*; Shimo, Michikuni*
no journal, ,
no abstracts in English
Yamada, Junya; Seya, Natsumi; Haba, Risa; Muto, Yasunobu; Hashimoto, Makoto; Shimizu, Takehiko; Takasaki, Koji; Yokoyama, Sumi*; Shimo, Michikuni*
no journal, ,
no abstracts in English
Hokama, Tomonori; Fujita, Hiroki; Iimoto, Takeshi*
no journal, ,
It is important to monitor alpha-ray emitting radionuclides in an airborne sample in case of emergency such as nuclear and radiation accidents. However, it was difficult to assess concentrations of their artificial alpha-ray emitting radionuclides because of the abundance of natural radionuclides. In this research, I develop the emergency monitoring system for artificial radionuclides emitting alpha-ray such as plutonium in the air, using survey meter and multiple time interval analysis. The detection limit of this developed monitoring system was 2.510
Bq cm in concentration of artificial radionuclide in the air.
Saito, Kimiaki
no journal, ,
no abstracts in English
Yamada, Ryohei; Hashimoto, Hiroki*; Tamakuma, Yuki*; Hosoda, Masahiro*; Tokonami, Shinji*
no journal, ,
no abstracts in English
Hosoda, Masahiro*; Saito, Kimiaki; Mikami, Satoshi; Sanada, Tetsuya*; Omori, Yasutaka*; Takeda, Hikaru*; Yamada, Takahiro*; Hirao, Shigekazu*; Tani, Kotaro*; Orita, Makiko*; et al.
no journal, ,
no abstracts in English
Hokama, Tomonori
no journal, ,
no abstracts in English
Sasaki, Miyuki
no journal, ,
Since 2011, JAEA has conducted extensive radiation monitoring both inside and outside Fukushima Prefecture. The data obtained from these efforts have been instrumental in various applications, including the lifting of evacuation orders in difficult-to-return zones. However, the initial response immediately after the disaster faced challenges such as the earthquake, subsequent power outages, and communication failures, leading to issues in sharing the results of emergency monitoring. Drawing from these experiences, revisions have been made, including updates to the national guidelines for nuclear disaster response. Building on the expertise gained through environmental monitoring in Fukushima, JAEA has been advancing the development of measurement technologies using unmanned aerial vehicles (UAVs). Leveraging these technologies, we have established a monitoring and analysis system with a focus on emergency response. In this presentation, we will share the results of applying monitoring techniques refined through Fukushima's experiences to enhance nuclear disaster preparedness.
Hokama, Tomonori
no journal, ,
no abstracts in English
