• A “dirty bomb” is a device that uses conventional explosives such as TNT or dynamite to disperse radioactive material over a wide area, thereby contaminating it. This is different from nuclear weapons, which rely on a nuclear fission reaction to create an extremely powerful explosive explosion (although the term was originally coined for a nuclear weapon that has caused excessive contamination). The destructiveness of a dirty bomb will depend primarily on the strength of a conventional explosion. However, the resulting radioactive contamination would potentially render the area useless, or at least cause people to panic. Making a dirty bomb is not much more difficult than making a conventional bomb, and many types of radioactive materials can be used. Weapon-grade materials or spent nuclear fuel will cause the most significant contamination, but even medical materials such as radium can be used. Although this type of weapon has few traditional military uses, it can serve well as a weapon of terror.