Discrimination of high-Z materials using muon scattering tomography

Legacy nuclear waste can contain anything from parts of fuel rods to coveralls worn by the workers, stored inside large concrete containers. It is important to identify the materials present in these containers with techniques that are non-invasive and scalable, in order to be applied for a considerable amount of large volumes. Using muon scattering tomography, we show that it is possible to discriminate uranium blocks from lead, tungsten and plutonium, inside a concrete filled cylinder, by selecting the muon tracks that pass through the volumes of interest. There is very good discrimination between uranium and lead or tungsten for block sizes upwards of 2 × 2 × 2 cm
³
. We even show that we can discriminate between lumps of uranium and plutonium.