Dirty bomb
nuclear weapon that generated a significant amount of radioactive waste in the form of nuclear fallout. Due to the inefficiency of early nuclear weapons (as low as 2% or less), they tended to disperse large amounts of unused fissile material. The term does not necessarily refer to a specific nuclear weapon design, but is typically used to contrast with newer, more efficient bombs. Some nuclear weapon designs feature the inclusion of a salting metal which will create large amounts of long-lasting fallout radiation (most commonly cobalt) when radiated by the weapon core.
Another usage of the term is to talk about radiological weapons (see there for details). It refers especially to a weapon which would disperse radioactive material through conventional explosives. The term was put in focus on June 10, 2002, when U.S. officials announced they had captured an al-Qaida terrorist named José Padilla in Chicago's O'Hare International Airport a month earlier who was allegedly planning for such a device.
See also: nuclear weapon, nuclear weapon design, nuclear war, nuclear strategy, nuclear terrorism, doomsday machine, area denial
The term "dirty bomb" has also been used in the popular press to describe improvised explosive devices which are designed to disperse a chemical weapon payload, particularly when used in unconventional warfare.
