著者
永岡 美佳 藤田 博喜 中野 政尚 渡辺 均 住谷 秀一
出版者
日本保健物理学会
雑誌
保健物理 (ISSN:03676110)
巻号頁・発行日
vol.48, no.2, pp.104-113, 2013 (Released:2014-03-06)
被引用数
1 or 0

Monthly deposition samples were collected at the Nuclear Fuel Cycle Engineering Laboratories located about 115 km south of the Fukushima Daiichi Nuclear Power Plant (NPP), and the radioactive nuclides were analyzed. Although radionuclides such as 131I, 129mTe-129Te and 132Te-132I with 134Cs and 137Cs were observed by gamma spectrometry at the early time of the Fukushima Daiichi NPP accident, only 134Cs and 137Cs were detected as of September 2011. The annual depositions of 134Cs and 137Cs were about 19,000 and 17,000 Bq m-2, respectively in March 2011-February 2012 after the accident. Moreover, 90Sr was detected in some samples. Monthly 90Sr deposition in March 2011 was 5.1 Bq m-2 month-1 and then decreased after that. On the other hand, 239, 240Pu concentration was the same level with the concentration before the accident.
著者
中野 政尚 檜山 佳典 渡辺 均 住谷 秀一
出版者
公益社団法人 日本アイソトープ協会
雑誌
RADIOISOTOPES (ISSN:00338303)
巻号頁・発行日
vol.59, no.5, pp.319-328, 2010 (Released:2010-05-28)

排水中89Sr,90Sr分析を行うにあたって,β線エネルギーの違いを利用して,液体シンチレーションカウンタを用いた迅速分析法について検討した。本法により妨害核種(54Mn,60Co,106Ru,137Cs)を含む模擬排水試料を分析したところ,十分な分析精度と回収率が得られた。また従来法では分析に2~3週間要していたが,本法では3~4日間で分析できることから,排水中89Sr,90Sr分析として,十分に適用可能な優れた方法であることを確認した。
著者
中野 政尚 國分 祐司 武石 稔
出版者
日本保健物理学会
雑誌
保健物理 : hoken buturi (ISSN:03676110)
巻号頁・発行日
vol.44, no.1, pp.60-65, 2009-03

The tritium concentrations in seawater collected around the Tokai Reprpcessing Plant (TRP) were measured for 10,800 samples in 30 years from 1978. The tritium concentration, dillution factor and diffusion situation were investigated. As a result, the tritium was occationaly detected due to the discharge from TRP. But it was considered to be the result of expected diffusion assumed in the safety assessment. It was confirmed that the tritium concentration was much lower than the concentration limit defined in the law and that it was not concern of environmental safety.
著者
中野 政尚 國分 祐司 武石 稔
出版者
日本保健物理学会
雑誌
保健物理 (ISSN:03676110)
巻号頁・発行日
vol.44, no.1, pp.60-65, 2009 (Released:2010-10-08)

The tritium concentrations in seawater collected around the Tokai Reprpcessing Plant (TRP) were measured for 10,800 samples in 30 years from 1978. The tritium concentration, dillution factor and diffusion situation were investigated. As a result, the tritium was occationaly detected due to the discharge from TRP. But it was considered to be the result of expected diffusion assumed in the safety assessment. It was confirmed that the tritium concentration was much lower than the concentration limit defined in the law and that it was not concern of environmental safety.