Rapid three-dimensional visualization of radiation distribution in the environment from the sky
—Development of a drone-mounted camera system—
Monitoring the distribution of radioactive substances scattered and deposited in the environment after the accident at the Fukushima Daiichi Nuclear Power Station is important, particularly in the outdoor environment including the difficult-to-return zone in Fukushima Prefecture, to provide information to decontamination workers and a reference index to home-coming residents. Conventionally, distribution of radioactive substances has been measured with survey meters, but the measurement takes time for a wide area, requires preparation regarding poor terrain to eliminate the risk of injury, and thus creates concerns about increasing operating costs. Against this backdrop, a simpler and easier way to measure the distribution of radioactive substances in a broad area has been sought.
The Japan Atomic Energy Agency (JAEA) and Chiyoda Technol Corporation, in cooperation with Sakae Seisakusho Co., Ltd. and other local companies in the Hamadori region of Fukushima Prefecture, have developed a drone-mount remote radiation imaging system using a compact, lightweight Compton camera, which can detect the locations of radioactive sources. The technology developed at the Collaborative Laboratories for Advanced Decommissioning Science of JAEA (Tomioka Town) and Fukushima Sales Office of Chiyoda Technol (Naraha Town) uses a 3D-LiDAR (Light Detection and Ranging) to measure the distance to the ground surface, creates a 3D topographical model, and visualizes the distribution of radioactive substances through the model. This technology enables aerial measurement, thus providing wider, quicker, and safer measurement.