Detailed deposition density maps constructed by large-scale soil sampling for -ray emitting radioactive nuclides from the Fukushima Dai-ichi Nuclear Power Plant accident
福島第一原子力発電所事故に起因する線放出核種に対する大規模土壌採取に基づく詳細な沈着量マップ
斎藤 公明 ; 谷畑 勇夫*; 藤原 守; 齊藤 敬*; 下浦 享*; 大塚 孝治*; 恩田 裕一*; 星 正治*; 池内 嘉宏*; 高橋 史明 ; 木内 伸幸 ; 三枝 純; 関 暁之 ; 武宮 博; 柴田 徳思*
Saito, Kimiaki; Tanihata, Isao*; Fujiwara, Mamoru; Saito, Takashi*; Shimoura, Susumu*; Otsuka, Takaharu*; Onda, Yuichi*; Hoshi, Masaharu*; Ikeuchi, Yoshihiro*; Takahashi, Fumiaki; Kinouchi, Nobuyuki; Saegusa, Jun; Seki, Akiyuki; Takemiya, Hiroshi; Shibata, Tokushi*
The soil deposition density maps of -ray emitting radioactive nuclides from the Fukushima Daiichi Nuclear Power Plant (NPP) accident were constructed on the basis of the results from large-scale soil sampling. The 10,915 soil samples were collected at 2,168 locations. -rays emitted from the samples were measured by Ge detectors and analyzed using a reliable unified method. The determined radioactivity was corrected to that as of June 14, 2011 by taking into account the intrinsic decay constant of each nuclide. Finally the maps were created for Cs, Cs, I, Te and Ag. The radioactivity ratio of Cs to Cs was almost constant as 0.91 irrelevant to the soil sampling location. Effective doses for 50 years after the accident were evaluated for external and inhalation exposures due to the observed radioactive nuclides. The radiation doses from radioactive cesium were found to be much higher than those from other radioactive nuclides.