What is "radiological weapon"

n. A weapon, often a bomb, designed to achieve injury or contamination of a target by dispersing harmful radioisotopes.

A radiological weapon or radiological dispersion device (RDD) is any weapon that is designed to spread radioactive material with the intent to kill and cause disruption. According to the U.S. Department of Defense, an RDD is "any device, including any weapon or equipment, other than a nuclear explosive device, specifically designed to employ radioactive material by disseminating it to cause destruction, damage, or injury by means of the radiation produced by the decay of such material”.

One type of RDD is a "conventional explosive combined with some type of radiological material", also known as a dirty bomb. It is not a true nuclear weapon and does not yield the same explosive power. It uses conventional explosives to spread radioactive material, most commonly the spent fuels from nuclear power plants or radioactive medical waste. "It is not a Weapon of Mass Destruction (WMD), but rather, as researcher Peter Probst calls it, a “weapon of mass disruption” (Hughes, 2002). In fact, effective dispersal ranges are rather limited. Most deaths (if any) would come from the initial explosion (non-nuclear), but it does depend on the type of radiological material used. (Department of Homeland Security [DHS], 2003)."

Another version is the salted bomb, a true nuclear weapon designed to produce larger amounts of nuclear fallout than a regular nuclear weapon.