Portable radiation-detection instruments for distinguishing nuclear from non-nuclear munitions

The emission of gamma rays and fast neutrons by nuclear materials provides a simple means for distinguishing between real nuclear munitions and other assemblies that are nonnuclear, such as nuclear-explosive-like test assemblies (NELAs) and conventional munitions. The presence or absence of significant numbers of neutrons and characteristic plutonium, gamma rays is a distinguishing attribute for plutonium munitions. The presence of energetic gamma rays from /sup 232/U daughters, if present in sufficient number, is a distinguishing attribute for highly enriched uranium munitions. Some portable instruments are being developed for verifying that munitions are or are not nuclear, and others are already commercially available. The commercial ones have been evaluated for preflight non-nuclear verification of NELAs in Air Force flight tests.<>