Identification of nuclear fuel materials during decommissioning by short-wave infrared hyperspectral imaging

This paper describes how hyperspectral imaging can be used to distinguish uranium dioxide (UO2) from concrete in-situ, using stand-off measurement methods. This suggests hyperspectral imaging is useful for the decommissioning of nuclear reactors and related facilities, where there is a requirement to identify and remove fissile material rapidly. A short-wave infrared camera is used which captures a light spectrum, between 1000 nm and 2500 nm, at each pixel. Hyperspectral images of 6 concrete samples and 6 simulated fuel debris pellets comprising of uranium dioxide and stainless steel are captured, resulting in 1000’s of spectra. The concrete samples are each heat-treated at temperatures between 200 and 1200 °C and includes sand and stones collected from the Niida river in Fukushima, to create realistic samples. The results show that UO2 pellets have distinctive spectral features not present in the concrete mixture and its components. This enables rapid identification of fuel debris using hyperspectral imaging which has the potential to enhance nuclear decommissioning and clean-up operations.