Visualization of radioactive substances by integrating radiation measurement and 3D optical measurement inside the Fukushima Daiichi Nuclear Power Station

放射線計測と光3次元計測を統合することによる福島第一原子力発電所サイト内における放射性物質の可視化

佐藤 優樹  ; 谷藤 祐太 ; 寺阪 祐太   ; 森下 祐樹   ; 宇佐美 博士; 冠城 雅晃   ; 川端 邦明   ; 鳥居 建男  

Sato, Yuki; Tanifuji, Yuta; Terasaka, Yuta; Morishita, Yuki; Usami, Hiroshi; Kaburagi, Masaaki; Kawabata, Kuniaki; Torii, Tatsuo

The Fukushima Daiichi Nuclear Power Station (FDNPS), operated by Tokyo Electric Power Company Holdings, Inc., went into meltdown after the occurrence of a large tsunami caused by the Great East Japan Earthquake of March 11, 2011. The radiation distribution measurements inside the FDNPS are indispensable to execute decommissioning tasks. We have conducted the radiation imaging experiment inside the FDNPS building using the Compton camera. The high-dose contamination (up to 3.5 mSv/h) was visualized. We also created a three-dimensional (3D) radiation distribution map inside the FDNPS building by integrating the radiation image obtained by the Compton camera into the point cloud data of the experimental environment acquired using the scanning laser range finder. In addition, we introduce the photogrammetry technique to create the 3D structure model of the experimental environment. The radiation image is superimposed on the 3D structure model created using the photogrammetry to visually recognize the radioactive substances. In the presentation, our recent study about the radiation imaging technology for measurements of the distribution of radioactive substances inside the FDNPS is discussed.