Release of Pu Isotopes from the Fukushima Daiichi Nuclear Power Plant Accident to the Marine Environment Was Negligible
Release of Pu Isotopes from the Fukushima Daiichi Nuclear Power Plant Accident to the Marine Environment Was Negligible
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福岛第一核电站事故向海洋环境释放的钚同位素微乎其微
DOI：
10.1021/es502480y
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发表时间：
2014-08-19
影响因子：
11.4
通讯作者：
Yamada, Masatoshi
中科院分区：
文献类型：
--
作者：
Bu, Wenting;Fukuda, Miho;Yamada, Masatoshi
福岛第一核电站（FDNPP）事故产生的钚同位素在大气中的沉积已在FDNPP现场周围的陆地环境中观察到，但尚未研究其在海洋环境中的沉积。钚在海洋环境中的可能污染引起了科学界和公众的极大关注。为了充分了解这种可能的污染钚同位素从FDNPP事故的海洋环境，我们收集了海洋沉积物岩心样品在30公里的区域内的FDNPP网站在西北太平洋约两年后的事故。测定了样品中的钚同位素（Pu-239、Pu-240和Pu-241）和放射性铯同位素（Cs-134和Cs-137）。放射性铯的高放射性和Cs-134/Cs-137放射性比值约为1（衰变校正至2011年3月15日），表明这些样品受到FDNPP事故释放的放射性核素的污染。然而，与FDNPP事故前的背景水平相比，Pu 239 +240和Pu-241的活性较低。Pu-240/Pu-239和Pu-241/Pu-239的比值表明，全球沉降和太平洋试验场（PPG）近场沉降是海洋沉积物中Pu污染的主要来源。由于钚同位素是颗粒反应性的，它们可以很容易地与海洋沉积物结合，我们得出的结论是，从FDNPP事故中释放到海洋环境中的钚同位素可以忽略不计。
Atmospheric deposition of Pu isotopes from the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident has been observed in the terrestrial environment around the FDNPP site; however, their deposition in the marine environment has not been studied. The possible contamination of Pu in the marine environment has attracted great scientific and public concern. To fully understand this possible contamination of Pu isotopes from the FDNPP accident to the marine environment, we collected marine sediment core samples within the 30 km zone around the FDNPP site in the western North Pacific about two years after the accident. Pu isotopes (Pu-239, Pu-240, and Pu-241) and radiocesium isotopes (Cs-134 and Cs-137) in the samples were determined. The high activities of radiocesium and the Cs-134/Cs-137 activity ratios with values around 1 (decay corrected to 15 March 2011) suggested that these samples were contaminated by the FDNPP accident-released radionuclides. However, the activities of Pu239+240 and Pu-241 were low compared with the background level before the FDNPP accident. The Pu atom ratios (Pu-240/Pu-239 and Pu-241/Pu-239) suggested that global fallout and the pacific proving ground (PPG) close-in fallout are the main sources for Pu contamination in the marine sediments. As Pu isotopes are particle-reactive and they can be easily incorporated with the marine sediments, we concluded that the release of Pu isotopes from the FDNPP accident to the marine environment was negligible.