Radiation imaging using an integrated Radiation Imaging System based on a compact Compton camera under unit 1/2 exhaust stack of Fukushima Daiichi Nuclear Power Station

The Fukushima Daiichi Nuclear Power Station (FDNPS) went into meltdown after being hit by a large tsunami caused the Great East Japan Earthquake on 11 March 2011. Measuring and understanding distribution of radioactive contamination inside FDNPS is essential for decommissioning work, reducing exposure to workers, ensuring decontamination. This paper reports visualization tests in Unit 1/2 exhaust stack using compact Compton camera. Fixed-point measurements were conducted only camera moving an integrated radiation imaging system (iRIS) that combines with simultaneous localization mapping device. For measurements, operator carrying iRIS acquires data continuously while walking passage near stack. With both types high-intensity was detected at base stack, detailed three-dimensional (3D) obtained from measurement. fixed-point estimated source intensity reconstructed image acquired Furthermore, workers can experience work environment before actual importing 3D structure model virtual reality displaying image.