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Sakashita, Satoshi; Okui, Masahiro; Yoshida, Tadayoshi; Uezu, Yasuhiro; Okuda, Eiichi
JAEA-Review 2022-012, 42 Pages, 2022/06
JAEA-Review-2022-012.pdf:2.96MB
In this report, results of investigating fire alarm detectors status in order to understand the actual situation of false alarm occurrence and measures to systematically update of them. Based on results of this investigation, measures to systematically update of detectors were taken in order to reduce false fire alarm reports in a harsh environment and aged detectors. Numbers of detectors, false alarms were investigated. Furthermore, causes of their occurrence were investigated for three years (2018-2020). As a result of this investigation, it was found that most of the 34,400 fire alarm detectors in JAEA have been used for more than 20 years. In the last 3 years, 65 false alarms have been reported, 60% of which were found to have been used where the environment should be improved. It was also found that there are many cases where false alarms are reported from a detector within 14 years after installation. Based on the above, three basic policies were formulated. First of all, database will be built for fire alarm maintenance and inspection, secondly, installation location of fire alarm will be improved, and finally, detectors will be updated with reference to the manufacture's plan. According to the three basic policies, it is considered that the reports of false fire alarms will be able to reduced.
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.
Maeda, Tsuyoshi; Endo, Yuya; Uezu, Yasuhiro
Hoken Butsuri (Internet), 54(3), p.177 - 180, 2019/10
no abstracts in English
Saito, Kimiaki; Takahara, Shogo; Uezu, Yasuhiro
Nihon Genshiryoku Gakkai-Shi ATOMO
, 60(2), p.111 - 115, 2018/02
no abstracts in English
Takeishi, Minoru; Miyagawa, Naoto; Uezu, Yasuhiro; Nakano, Masanao; Koarashi, Jun; Mizutani, Tomoko; Kono, Takahiko; Hiyama, Yoshinori*; Fujii, Yoshiyuki*; Kikuchi, Masaaki*; et al.
JAEA-Review 2006-024, 133 Pages, 2006/09
JAEA-Review-2006-024.pdf:6.69MB
Based on the regulations (the safety regulation of Tokai reprocessing plant, the safety regulation of nuclear fuel usage facilities, radiation safety rule, the regulation about prevention from radiation hazards due to radioisotopes, which are related with the nuclear reguratory acts, and the local agreement concerning with security and environment conservation around nuclear facilities, the water pollution control law, and byelaw of Ibaraki prefecture), this report describes the effluent control results of low level liquid waste discharged from the JAEA's Nuclear Fuel Cycle Engineering Laboratories in the fiscal year 2005, from 1st April 2005 to 31th March 2006. In this period, the concentrations and the quantities of the discharged radioactive materials from the reprocessing plant, the plutonium fuel fabrication facilities, and the other facilities were much lower than the authorized limits of the above regulations.
Takeishi, Minoru; Naoto, Miyagawa,; Hitoshi, Watanabe,; Uezu, Yasuhiro; Mizutani, Tomoko; Hiyama, Yoshinori*; Fujii, Jun*
JNC TN8440 2005-008, 136 Pages, 2005/08
JNC-TN8440-2005-008.pdf:4.14MB
This report was written about the effluent control in JNC Tokai Works from 1st April 2004 to 31th March 2005. In this period, the quantities and concentrations of retroactivities in liquid waste from Tokai Works were under the discharge limits of "Safety Regulations for the Tokai Reprocessing Plant " and regulations of government.
Shinohara, Kunihiko; Takeishi, Minoru; Hitoshi, Watanabe,; Uezu, Yasuhiro; Mizutani, Tomoko; Hiyama, Yoshinori*; Fujii, Jun*
JNC TN8440 2004-015, 138 Pages, 2004/12
JNC-TN8440-2004-015.pdf:7.78MB
This report was written about the effluent control in JNC Tokai Works from 1st April 2003 to 31th March 2004. In this period, the quantities and concentrations of retroactivities in liquid waste from Tokai Works were under the discharge limits of "Safety Regulations for the Tokai Reprocessing Plant" and regulations of government.
Takeishi, Minoru; Naoto, Miyagawa,; Hitoshi, Watanabe,; Uezu, Yasuhiro; Nakano, Masanao; Takeyasu, Masanori; Isozaki, Hisaaki
JNC TN8440 2004-002, 149 Pages, 2004/06
JNC-TN8440-2004-002.pdf:3.78MB
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 inhabitant due to the radioactivity discharged from the plant during April 2003 to March 2004. Appendices present comprehensive information, such as monitoring program, monitoring results, meteorological data and annual discharges from the plant.
Uezu, Yasuhiro; Hashimoto, Tetsuo*
Saikuru Kiko Giho, (24), p.39 - 45, 2004/00
One kind of discrimination with swiftness and precision of artificial long-lived such as plutonium from natural short-lived such as progenies of radon without chemical separation is time interval analysis (TIA) based on difference existences of time intervals of radiation pulses between short and long lived. The probability of extraction of short lived is higher than long lived within optional fixed time.Lower limit of detection applied to a probability theory was examined in this report adding to principle of TIA theory, measuring system and results of trial tests.
Mizutani, Tomoko; Uezu, Yasuhiro; Hitoshi, Watanabe,; Takeishi, Minoru; Shinohara, Kunihiko; Hiyama, Yoshinori*; Kikuchi, Masaaki*
JNC TN8440 2003-024, 144 Pages, 2003/11
JNC-TN8440-2003-024.pdf:7.72MB
This report was written about the effluent control in JNC Tokai Works from 1st April 2002 to 31th March 2003. In this period, the quantities and concentrations of retroactivities in liquid waste from Tokai Works were under the discharge limits of "Safety Regulations for the Tokai Reprocessing Plant" and regulations of government.
Uezu, Yasuhiro; Watanabe, Hitoshi; Takeishi, Minoru; Shinohara, Kunihiko
Saikuru Kiko Giho, (14), 181- Pages, 2002/00
None
Uezu, Yasuhiro; Nakano, Masanao; Fujita, Hiroki; Watanabe, Hitoshi; Maruo, Yoshihiro; Shinohara, Kunihiko
Proceedings of the International Workshop on Distribution and Speciation of Radionuclides in the Environment, p.354 - 357, 2000/00
Iodine-129 is an important radionuclide for environmental assessment, because it has a long half-life. A new analytical technique with Microwave Induced Plasma Mass Spectrometry (MIP-MS) was applied to the determination of iodine-129 (
I) in the environmental samples. Environmental samples contain a large amount of matrices elements. Therefore, the interference elements were eliminated by ashing at 1000
C, and iodine was trapped by activated charcoal and finally extracted by tetramethylammonium hydroxide (TMAH). I-129 in the soil sample was also analyzed by conventional method [neutron activation analysis (NAA)] and MIP-MS method. The analytical data by MIP-MS and NAA methods showed excellent agreement.
Uezu, Yasuhiro; Morita, Shigemitsu; ; ; ;
Health Physics, 0 Pages, 1997/00
None
Uezu, Yasuhiro
no journal, ,
The Great East Japan Earthquake hit on March 11, 2011. The Earthquake and following tsunami struck huge area. The Fukushima Daiichi Power Station run by Tokyo Electric Power Company lost power and reactor cooling failed due to an operative power generator. This presentation shows JAEA's activities such as an environmental emergency monitoring, evaluation personal exposure, decontamination and so on.
Yanagisawa, Kayo*; Kuwata, Haruka*; Hagiwara, Hiroki; Uezu, Yasuhiro
no journal, ,
no abstracts in English
Uezu, Yasuhiro
no journal, ,
This paper was written in JAEA's Activities to Fukushima accident by the eastern Japan great earthquake, risk communication and human resource develops. About 500,000 inhabitants in Fukushima Prefecture, almost all of whom are under a 1-2 mSv of external exposure. This is based on calculation air dose in the residential areas because the residents did not have personal dosimeter. About internal exposure determined using by (WBC), about 300,000 who have screened by WBC, 26 were over 1 mSv of committed effective dose. Using this data, it was able to conclude that 99.9% of inhabitants were below 1 mSv. Because the radioactivity in foodstuffs has been monitored since the earliest stages, and this monitoring has been effective in keeping the food safe to consume.
Uezu, Yasuhiro; Ejiri, Akira; Yoda, Tomoyuki
no journal, ,
The Great East Japan Earthquake occurred on 11th March 2011. The Tsunami attacked the Fukushima Daiichi Nuclear Power Station of Tokyo Electric Power Co. As a result, electric power was lost, furthermore electronic power generators were broken. After failing to restore power, there was an explosion and a large amount of radionuclides were released to the atmosphere. Japan Atomic Energy Agency (JAEA) monitored air dose rates, radionuclides in the air and environmental samples. At that time, there were many problems in the environmental radiation monitoring. The dose was beyond the range of the air dose monitor in monitoring car. The Ge detector's iron and lead shields were contaminated by the air. No standard source as "the phantom" could be obtained for children under 4. The JAEA solved these problems by developing new monitoring techniques. In this presentation, these improvements are shown and proposed as a new generation environmental radiation monitoring technique.
