Active and passive CT for waste assay using LaBr3(Ce) detector

An active and passive computed tomography system has been developed that localizes and quantifies 239Pu in a waste drum. The active (transmission) measurement uses an external gamma source and LaBr3(Ce) detector to determine the attenuation map of waste drum contents at different selected energies. The passive (emission) measurement uses multiple LaBr3(Ce) detectors to record the spectra of gamma-rays emitted from within the drum. The active and passive data sets are then coupled to quantitatively assay drum contents for 239Pu.