Radiological contamination devices

A radiological dispersal device (RDD) explodes, contaminating 10 square miles with radioactive cobalt (Co-60). The highest measured radiation level is about 10 meters from the site of the explosion and it reads about 150 mrem/hr. The average radiation dose through the affected area is 5 mrem/hr, and about 500,000 people live and work in this area. The device itself consisted of 1,000 pounds of explosive, set off near City Hall. 

Fortunately, skin or wound contamination rarely presents a life-threatening risk to either patients or health care personnel (5). The best possible scenario is decontamination in the field before transport however, following an attack with a radiologic dispersion device (ROD), patients suffering trauma will most likely present to emergency departments before undergoing external contamination. 

Sohier, A., and Hardeman, F. (2005). Radiological Dispersion Devices Are we prepared (NKS Conference on Radioactive Contamination in Urban Areas, May 7-9, 2003, Riso, Roskilde, Denmark), J. Envir. Radioact. (In press.)... 

A radiation threat, commonly referred to as a "dirty bomb" or "radiological dispersion device (RDD) , is the use of common explosives to spread radioactive materials over a targeted area. It is not a nuclear blast. The force of the explosion and radioactive contamination will be more localized. While the blast will be immediately obvious, the presence of radiation will not be clearly defined until trained personnel with specialized equipment are on the scene. As with any radiation, you want to try to limit exposure. 

What is more practical, therefore more probable, for a terrorist attack is the use of a radiological dispersion device (RDD), which can either deploy a long-lived radioactive isotope to contaminate a wide area or release a biologically active isotope and affect those exposed more rapidly. Such devices would likely use high explosives to disperse the radioactive material into the atmosphere, causing contamination of a large area. These are referred to as dirty bombs (Figure 5.6). 

Detonation of an improvised or stolen nnclear weapon by terrorists is the worst-case radiological attack scenario (5). Althongh difficnlt to construct, due to requirements for sophisticated engineering and expertise, an improvised nuclear device could produce a yield similar to the Hiroshima bomb, with release or radiation, blast, thermal pulses, and radioactive fallout (1). At a minimum, a small nuclear detonation could cause damage equal or exceeding the September 11 attacks in New York City. Even if the nuclear detonation were unsuccessful, the conventional explosion associated with the device could cause significant environmental contamination with the nuclear weapons material, such as plutonium or uranium (1). 

Because terrorists are unlikely to announce an attack with a simple radiological device or a ROD, there may be no warning that contaminated patients are arriving at an... 

FDA. 1998. Accidental radioactive contamination of human food and animal feeds Recommendations for state and local agencies. U.S. Department of Health and Human Services. Food and Drug Administration. Center for Devices and Radiological Health. Rockville, MD 20850. August 13, 1998. 

Two systems for radiological control are required in the case of membrane plant for radioactive waste processing first, for process control, and second, for securing the staff and for avoiding the spread of contamination. The latter usually exists if the installation is located in nuclear power plant or some other nuclear center. Some security devices have to be applied in rooms where membrane plant will be placed. The lead shielding in places where increased radioactivity is expected should be installed in accordance with precise preliminary measuranents and dose estimations. 

A nuclear terrorist incident can involve the detonation or threatened detonation of a nuclear bomb or the detonation or threatened detonation of an explosive device that includes nuclear materials. Terrorists could also cause a nuclear incident by detonating an explosive device near a nuclear power plant or attacking nuclear cargo during transport. Terrorists could contaminate food or other products with radioactive materials. Simple radiological devices such as an isotope, if placed in public, could spread radiation without the use of an explosive device. 

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