PNNL

Abstract

The resources devoted to interdicting special nuclear materials have increased considerably over the last several years in step with growing efforts to counter nuclear proliferation and nuclear terrorism. This changing landscape has led to a great deal of current research and development that aims to improve the effectiveness of technology now deployed worldwide. The interdiction of special nuclear materials is most commonly addressed by detecting and characterizing emitted gamma rays, but modest signature emissions can be obscured by attenuating material and must be differentiated from large and highly variable environmental background. While this makes gamma-ray detection of special nuclear materials a daunting technical challenge, a host of new detection technologies are now emerging. We thus review special nuclear material signatures, the physics of detection approaches, and detection performance metrics. The use of benchmark materials aids our discussion and comparison of detection methods.