Trend of 137Cs concentration in river water in the medium term and future following the Fukushima nuclear accident
Trend of 137Cs concentration in river water in the medium term and future following the Fukushima nuclear accident
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DOI：
10.1016/j.chemosphere.2018.10.017
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发表时间：
2019-01-01
期刊：
影响因子：
8.8
通讯作者：
Sakuma, Kazuyuki
中科院分区：
文献类型：
--
作者：
Nakanishi, Takahiro;Sakuma, Kazuyuki
研究福岛第一核电站(FDNPP)事故中放射性铯在河流系统中的迁移行为，对于预测未来的污染状况，提出有效的减少暴露的对策是至关重要的。我们对福岛第一核电站周围两条河流的Cs-137浓度进行了为期三年(2015年4月-2018年3月)的观测。结果表明，福岛第一核电站事故发生后的四到七年间，河水中的溶解和颗粒态Cs-137浓度呈下降趋势。两条河流的溶解Cs-137浓度和颗粒态Cs-137浓度具有相似的时间模式，且随时间呈下降趋势。但溶解态Cs-137浓度的半衰期比颗粒态Cs-137浓度的半衰期要长，且季节变化与水温有关。在事故发生后的三年内，溶解Cs-137浓度的环境半衰期比以往报道的值要长，这表明溶解Cs-137浓度的下降趋势是随着时间的推移逐渐减小的。溶解Cs-137浓度的温度依赖性逐年减弱。根据我们提出的D-10方程，溶解的Cs-137浓度可能会在几十年内保持在相同的水平。本研究的结果促进了我们对福岛核电站事故对河流系统的中期和长期影响的了解。(C)2018年作者。爱思唯尔有限公司出版。
It is a critical to examine the migration behavior of radiocesium derived from the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident in river systems to predict the future contamination status and propose effective countermeasures to reduce exposure. We conducted a three-year-long observation (April 2015-March 2018) of the Cs-137 concentration in two rivers which located surrounding the FDNPP. The result revealed a declining trend for the dissolved and particulate Cs-137 concentration in river water from four to seven years after the FDNPP accident. The dissolved and particulate Cs-137 concentrations for both rivers had similar temporal patterns and showed declining trends with time. However, the dissolved Cs-137 concentration had longer half-life than the particulate Cs-137 concentration and large seasonal variations related to water temperature. The environmental half-life for the dissolved Cs-137 concentration was longer than previous reported values within three years after the accident, suggesting that the declining trend for the dissolved Cs-137 concentration is gradually decreasing with time. The temperature dependency of the dissolved Cs-137 concentration became weaker year by year. From the D-10 equation we proposed, the dissolved Cs-137 concentration will likely remain at the same level for several decades. The results of the present study promote our understanding of both the medium- and long-term impacts of the FDNPP accident on river systems. (C) 2018 The Authors. Published by Elsevier Ltd.