Terrorist use of Radiological Dispersal Devices (RDD)—often called “dirty nuke” or “dirty bomb”—is considered far more likely than use of a nuclear explosive device.   Radiological Dispersal Devices (RDD) combines a conventional explosive device—such as a bomb—with radioactive material. It is designed to scatter dangerous and sub-lethal amounts of radioactive material over a general area. Such Radiological Dispersal Devices (RDDs) appeal to terrorists because they require limited technical knowledge to build and deploy compared to a nuclear device. Also, the radioactive materials in Radiological Dispersal Devices (RDDs) are widely used in medicine, agriculture, industry, and research, and are easier to obtain than weapons grade uranium or plutonium.

The primary purpose of terrorist use of Radiological Dispersal Devices (RDD) is to cause psychological fear and economic disruption. Some devices could cause fatalities from exposure to radioactive materials. Depending on the speed at which the area of the Radiological Dispersal Devices (RDD) detonation was evacuated or how successful people were at sheltering-in-place, the number of deaths and injuries from an Radiological Dispersal Devices (RDD) might not be substantially greater than from a conventional bomb explosion.

Radiological Dispersion Device preparedness from Federal Emergency Management Agency (FEMA)

Radiological Dispersion Device preparedness from Centers for Disease Control and Prevention (CDC)