Radiation Terrorism Weapon Types 

Air blasts cause little fallout

Atomic bomb survivors: some mental retardation from in-utero exposure,
some increase in cancer. Not great studies.

 - Radiation Exposure Device (RED) - A radiation exposure device is a
simple radiologic source, or radiation-generating device that is set up
to expose the public. Examples of such sources would be nuclear medicine
isotopes, radiography sources, brachytherapy sources, and teletherapy
sources. REDs typically do not involve a contamination mechanism. 

 - Radiation Contamination - Terrorists may use contamination as the
primary mode of terrorism without an intrinsic explosive mechanism used
for dispersion. 
 + Food / Water sources - Food and water sources could be contaminated by a terrorist. 
 + Dispersion would occur via typical food and water distribution mechanism. 
 + Transportation system - A terrorist could attempt to breach a
   radioactive transportation shipment causing dispersion of its contents. 
 + Nuclear Reactor-Terrorists could attempt to breach nuclear reactor security with the 
   intent of 
  1) disruption electrical power, 
  2) breaching containment mechanisms, or 
  3) to attempt to cause a loss-of-coolant accident (LOCA) leading to a core meltdown. 

 - Radionuclide Dispersal Device or Weapon (RDD or RDW) - A radionuclide
dispersal device is also known as a "dirty bomb." Such a device consists
of a radioactive source combined with an explosive to facilitate
dispersion of the radioactive material. Fission does not occur with a
RDD. The greatest chance for radiation exposure is in the event of
discovering and attempting to safe the device. 

 - Improvised Nuclear Device (IND) - Low yield (low efficiency) nuclear
devices could be constructed by non-state organizations. These devices
may fail as a nuclear device, functio as a RDD instead. 

 - State Tactical Nuclear Weapon - These weapons are created by a state,
and hence more likely to be a higher-efficiency weapon, usually in the
kiloton range. Nationwide standards require local planners to consider
response consequences of a 10 kiloton (kT) detonation. 

 - The former Soviet Union "suitcase" nuke is the most common example of
a state-created tactical weapon. A "suitcase nuke." a 1 kT device, is
actually a small fusion weapon, utilizing tritium as the fusion
material. With the rapid deterioration of tritium, such weapons require
maintenance and refurbishing of tritium every 5-8 years. 

 - Strategic Nuclear Weapon - Strategic Nuclear weapons are state-created
nuclear weapons the megaton (MT) range. The largest former Soviet
warhead was reputed to be 50 MT in size.