Atmospheric discharge and dispersion of radionuclides during the Fukushima Dai-ichi Nuclear Power Plant accident. Part I: Source term estimation and local-scale atmospheric dispersion in early phase of the accident
Atmospheric discharge and dispersion of radionuclides during the Fukushima Dai-ichi Nuclear Power Plant accident. Part I: Source term estimation and local-scale atmospheric dispersion in early phase of the accident
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DOI：
10.1016/j.jenvrad.2012.02.006
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发表时间：
2012-07-01
影响因子：
2.3
通讯作者：
Nagai, Haruyasu
中科院分区：
文献类型：
--
作者：
Katata, Genki;Ota, Masakazu;Nagai, Haruyasu
将环境数据与大气扩散模拟相结合，在单位释放率(1Bqh(-1))的假设下，估算了2011年3月12日至14日福岛第一核电站(FNPP1)事故早期I-131和Cs-137的大气释放量。模拟采用的是WSPEEDI-II计算机核应急系统。在1号机组氢气爆炸后的3月12日下午和3月14日深夜，当FNPP1的空气剂量率增加时，估计了I-131(>；10(15)Bq h(-1))的主要释放。在这两个时期排放的高浓度羽流分别流向FNPP1的西北和西南方向。这些羽状物在沿途的地面上造成了大量的干沉积。总体而言，WSPEEDI-II使用估计的释放率再现了在福岛第一核电站周围监测站观察到的Cs-137的空间模式和空气剂量率的增加。模拟表明，由于3月14日夜间至3月15日上午排放的高浓度烟羽的干燥沉积，福岛第一核电站西南南部地区的空气剂量率显著增加。(C)2012爱思唯尔有限公司。版权所有。
The atmospheric release of I-131 and Cs-137 in the early phase of the Fukushima Dai-ichi Nuclear Power Plant (FNPP1) accident from March 12 to 14, 2011 was estimated by combining environmental data with atmospheric dispersion simulations under the assumption of a unit release rate (1 Bq h(-1)). For the simulation, WSPEEDI-II computer-based nuclear emergency response system was used. Major releases of I-131 (>10(15) Bq h(-1)) were estimated when air dose rates increased in FNPP1 during the afternoon on March 12 after the hydrogen explosion of Unit 1 and late at night on March 14. The high-concentration plumes discharged during these periods flowed to the northwest and south-southwest directions of FNPP1, respectively. These plumes caused a large amount of dry deposition on the ground surface along their routes. Overall, the spatial pattern of Cs-137 and the increases in the air dose rates observed at the monitoring posts around FNPP1 were reproduced by WSPEEDI-II using estimated release rates. The simulation indicated that air dose rates significantly increased in the south-southwest region of FNPP1 by dry deposition of the high-concentration plume discharged from the night of march 14 to the morning of March 15. (C) 2012 Elsevier Ltd. All rights reserved.