Radiological Dispersal Devices: Detection, Response, and Remediation

Abstract

Radiological dispersal devices (RDD) use conventional explosives or nonexplosive means such as sprayers to disseminate large amounts of radioactive material into the environment over a short period of time. The isotopes considered most suitable for an RDD are those with high activity, high photon energy, relatively short half-lives, dispersibility, and environmental persistence; most likely candidates are considered to be cesium-137, iridium-192, or cobalt-60. The costs and technological difficulties of constructing an RDD are considerable, as the radioactive materials pose a hazard to the device assemblers and accessing these materials has become increasingly difficult owing to the increase in types, number, and scope of security safeguards at locations with these materials. Tools for detection of the devices prior to detonation or dispersal are becoming more sophisticated, even when the devices are shielded. Although the lethal range of the blast and thermal energies released by the conventional explosives in an RDD would exceed that of the radiation (except in very sophisticated devices), the possibility of immediate panic and later reluctance to enter the areas or use goods or products from these areas could create economic and psychological damages that are disproportionate to the actual risks of injuries created. Recent advances in cleanup procedures (remediation) have been made that would decrease residual radiation in the affected areas more rapidly, allowing for earlier return of occupants and restoration of the economy.