Environmental contamination and external radiation dose rates from radionuclides released from the Fukushima nuclear power plant
Environmental contamination and external radiation dose rates from radionuclides released from the Fukushima nuclear power plant
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DOI：
10.1093/rpd/ncs040
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发表时间：
2012-09-01
影响因子：
1
通讯作者：
Takamura, Noboru
中科院分区：
文献类型：
--
作者：
Taira, Yasuyuki;Hayashida, Naomi;Takamura, Noboru
为了评估福岛核电站(FNPP)事故后的环境污染和外照射量，用伽玛能谱分析了各地区土壤样品中人工放射性核素的浓度。在核电站周围土壤样品中检测到6种人工放射性核素(I-131、Cs-134、Cs-137、Te-129M、Nb-95和Cs-136)。2011年3月22日，福岛市福岛核电站周围土壤样品中人工放射性核素污染的外部有效剂量计算为1.92.9 Sv h(1)(8.717.8 mSv y(1))。几个月后，这些计算的外部有效剂量为2011年6月29日福岛市的0.250.88 Sv h(1)(2.27.6 mSv y(1))。目前的研究表明，福岛第一核电站周围探测到的人造放射性核素主要转移到放射性铯(Cs-134和Cs-137)等长寿命放射性核素上，尽管由于I-131、Te-129M、Nb-95和Cs-136等短寿命放射性核素的衰变，目前的水平正在逐渐下降。因此，尽管国家正在努力将年暴露剂量降低到接近公共剂量限值1 mSv，但辐射暴露效力仍然存在。福岛第一核电站周围的长期环境监测有助于辐射安全，减少对居民的不必要接触。
To evaluate the environmental contamination and contributory external exposure after the accident at the Fukushima Nuclear Power Plant (FNPP), the concentrations of artificial radionuclides in soil samples from each area were analysed by gamma spectrometry. Six artificial radionuclides (I-131, Cs-134, Cs-137, Te-129m, Nb-95 and Cs-136) were detected in soil samples around FNPP. Calculated external effective doses from artificial radionuclide contamination in soil samples around FNPP were 1.92.9 Sv h(1) (8.717.8 mSv y(1)) in Fukushima city on 22 March 2011. After several months, these calculated external effective doses were 0.250.88 Sv h(1) (2.27.6 mSv y(1)) in Fukushima city on 29 June 2011. The present study revealed that the detected artificial radionuclides around FNPP mainly shifted to long-lived radionuclides such as radioactive caesium (Cs-134 and Cs-137) even though current levels are decreasing gradually due to the decay of short-lived radionuclides such as I-131, Te-129m, Nb-95 and Cs-136. Thus, radiation exposure potency still exists even though the national efforts are ongoing for reducing the annual exposure dose closer to 1 mSv, the public dose limit. Long-term environmental monitoring around FNPP contributes to radiation safety, with a reduction in unnecessary exposure to the residents.