This fact sheet explains the steps that the government and private sector take to protect our nation from the use of radiological dispersion devices, also called “dirty bombs.”
September 2011
Key Facts- The use of radiological dispersion devices, also called “dirty bombs,” is one scenario that the government and private sector consider in protecting our nation. A dirty bomb is not a nuclear weapon that creates a large blast. Rather, it is a combination of an explosive and radioactive material designed to spread radioactive material and contaminate a small area.
- Sources of radioactive material are used worldwide in a number of diverse applications. Radioactive sources are used to diagnose and treat disease; explore for petroleum and mineral resources; ensure the strength, integrity and quality of materials; sterilize medical products and consumer goods; improve food safety and abundance; create fresh water supplies from sea water; and provide power in diverse applications ranging from nanotechnologies to space exploration. Very small radioactive sources are even found in common everyday items such as smoke detectors, wrist watches and exit signs.
- Used nuclear power plant fuel is large, heavy and highly radioactive, which makes it extremely impractical for a dirty bomb. The average fuel assembly is 14 feet long and weighs up to 1,600 pounds. Handling the material under any circumstances requires special equipment. The used fuel is protected by the same security force and electronic surveillance equipment as the rest of the plant.
- Among the millions of radioactive sources that are used globally, only a small fraction would pose any appreciable radiation risk if used in a dirty bomb. Such sources are, as a rule, highly regulated by government agencies, which impose strict safety and security requirements. Since the Sept. 11, 2001, terrorist attacks, government and industry have implemented additional measures to provide security against intentional misuse of radioactive sources.
- Being near the site where a dirty bomb is exploded does not guarantee exposure to the radioactive material. An examination by a physician using sensitive radiation detection devices is necessary to determine if a person has been exposed to radiation.
Frequently Asked Questions
What is a dirty bomb?
A dirty bomb is a device that consists of a conventional explosive attached to radioactive material. The conventional explosive is used as a means to spread radioactive material to create an area of contamination. It is not a nuclear bomb and does not involve a nuclear explosion. Individuals in the vicinity of a dirty bomb could be harmed by the detonation of the conventional explosive, but it is unlikely that any serious health effects would result from the radiation.
How dangerous is a dirty bomb?
At the radiation levels created by most probable sources of radiation, there would not be enough radiation in the bomb to cause severe illness from exposure to radiation. The primary danger from the use of a dirty bomb is the explosive blast itself, even if the bomb uses a low-level radioactive source. Estimating exactly how much radiation might be at the site of the explosion would be difficult if the source of the radiation is unknown, but first responders would be able to determine the severity of any incident with their radiation detection equipment.
What should people do following an explosion of a dirty bomb?
People at the scene of an explosion would not know whether radioactive materials were involved at the time of the blast. If people are not seriously injured by the initial explosion, they should:
- Leave the immediate area on foot—do not take public transportation.
- Go inside the nearest building. Seeking immediate shelter will reduce exposure to any radioactive material at the scene of the explosion.
- Remove clothing as soon as possible and seal it inside a plastic bag. Save the clothing so that emergency response personnel can test it. Removing clothing will eliminate 90 percent of the radioactive contamination, according to the Centers for Disease Control and Prevention.
- Take a shower or wash yourself as completely as possible. This will reduce the amount of radioactive contamination.
- Seek more information from emergency response personnel who respond to the explosion.
What are the most important actions to take to reduce radiation exposure?
- Decrease the amount of time you spend near the radioactive source.
- Increase your distance from the radioactive source.
- Increase the shielding (by using a building or a vehicle) between you and the radioactive source.
Is evacuation or sheltering the better means of maintaining safety in the event of a radiological emergency?
In the event of a dirty bomb explosion, people who live nearby, but not in the immediate area of the blast, may be asked to stay home and take shelter rather than evacuate. This is called “sheltering in place” by emergency response organizations. Staying in your home or office may be the best safety measure because many radioactive materials decay rapidly and dissipate. The thick walls of your home or office will block much of the harmful radiation.
If you are outside when an alert of a dirty bomb is announced, try to remove clothing and shoes and place them in a plastic bag before entering your home or office. In severe weather, simply remove the outside layer of clothing.
In the case of sheltering or evacuation, keep your radio tuned to an emergency response network at all times for updates on the situation.
What happens when a person is exposed to radiation?
All of us are continuously exposed to radiation in everyday life because radiation is a natural part of our environment—in the rocks and soil of the earth, in our air, water and food, and even in the cells of our own bodies. Many people also receive exposure to radiation when they receive X-rays or undergo medical tests or treatments for disease.
With regard to dirty bombs, the question is whether there is a possibility of receiving radiation exposure far in excess of the amount that all of us receive every day. Excessive radiation can affect the body in a number of ways—ranging from mild effects such as skin reddening to fatal cancer—depending on the amount of radiation absorbed by the body, the type of radiation and the length of time a person is exposed. Although the detonation of a dirty bomb could cause serious injury from the explosion, it most likely would not have enough radioactive material in a form that would cause serious radiation sickness among a large number of people.
What are the experts saying?
U.S. Nuclear Regulatory Commission:
“Most [dirty bombs] would not release enough radiation to kill people or cause severe illness—the conventional explosive itself would be more harmful to people than the radioactive material. However, depending on the scenario, [a dirty bomb] explosion could create fear and panic, contaminate property and require potentially costly cleanup. … A dirty bomb is not a ‘Weapon of Mass Destruction’ but a ‘Weapon of Mass Disruption,’ where contamination and anxiety are the terrorists’ major objectives.”
Centers for Disease Control and Prevention:
“A dirty bomb uses dynamite or other explosives to scatter radioactive dust, smoke or other material. … The main danger from a dirty bomb is from the explosion, which can cause serious injuries and property damage. The radioactive materials used in a dirty bomb would probably not create enough radiation exposure to cause immediate serious illness, except to those who are very close to the blast site.”
Center for Nonproliferation Studies at the Monterey Institute of International Studies:
“To cause a large amount of radioactive contamination, [terrorists] would be drawn toward very high-activity sources. However, in order to prepare the source for effective dispersal by removing the shielding, terrorists would risk exposing themselves to lethal doses. … If they tried to protect themselves by shielding the source, the weight of the radiological dispersal device could significantly increase, thereby increasing the difficulty of delivering the device and causing successful dispersion of the radioactive material” (Commercial Radioactive Sources: Surveying the Security Risk, January 2003).