Transport and Redistribution of Radiocesium in Fukushima Fallout through Rivers
Transport and Redistribution of Radiocesium in Fukushima Fallout through Rivers
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DOI：
10.1021/acs.est.9b02890
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发表时间：
2019-11-05
影响因子：
11.4
通讯作者：
Saito, Kimiaki
中科院分区：
文献类型：
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作者：
Taniguchi, Keisuke;Onda, Yuichi;Saito, Kimiaki
福岛第一核电站（FDNPP）事故释放到环境中的放射性铯的最显着的量，在最初的5年详细的测量提供了新的见解放射性铯的河流再分布。我们发现，高初始放射性浓度的Cs-137轴承悬浮沉积物在河流之后，由一个陡峭的指数下降（λ（1）），延长到约1年后的事故，而在水中放射性铯的活性浓度的初始下降率是一个数量级高于切尔诺贝利后测量的速率。2011年6月至2015年8月期间，从阿武熊河向海洋输送的Cs-137总量为12 TBq，几乎所有放射性铯（96.5%）都以颗粒形式输送。Cs-137的主要来源是稻田，农田和城市地区[斑块形成单位（PFU）]，从38%的流域面积排放85%的输出Cs-137。一年后，放射性浓度降低，并表现出更渐进的二次下降（λ（2）），这与PFU地区放射性铯损失减少有关，而森林地区继续代表更稳定的污染物储存。
The Fukushima Daiichi Nuclear Power Plant (FDNPP) accident released the most significant quantity of radiocesium into the environment since Chernobyl, and detailed measurements over the initial 5 years provide new insights into fluvial redistribution of radiocesium. We found that the high initial activity concentration of Cs-137-bearing suspended sediment in rivers was followed by a steep exponential decline (lambda(1)) which extended to approximately 1 year after the accident, while the rate of initial decline in radiocesium activity concentration in water was an order of magnitude higher than rates measured after Chernobyl. Fluvial transport of Cs-137 to the ocean from the Abukuma river totaled 12 TBq between June 2011 and August 2015 and almost all this radiocesium (96.5%) was transported in the particulate form. The primary sources of Cs-137 were paddy fields, farmland, and urban areas [plaque-forming unit (PFU)], discharging 85% of the exported Cs-137 from 38% of the watershed area. After 1 year, activity concentrations were lower and exhibited a more gradual secondary decline (lambda(2)) which was associated with reduced radiocesium losses from PFU areas, while forest areas continue to represent more stable contaminant stores.