"Nuclear radiation, invisible and detectable only with special instruments, has the power to terrify-in part because of its association with nuclear weapons-and to become an instrument of terrorists. Radioactive isotopes can be spread widely with or without high explosives by a radiological dispersion device (RDD) or so-called dirty bomb. This paper provides a general overview of the nature of RDDs and sources of material for them and estimates the effects of an assault, including casualties and economic consequences. Many experts believe that an RDD is an economic weapon capable of inflicting devastating damage on the United States. This paper is in full agreement with that assessment and makes some quantitative estimates of the magnitude of economic disruption that can be produced by various levels of attack. It is also generally believed that even a very large RDD is unlikely to cause many human casualties, either immediately or over the long term. A careful examination of the consequences of the tragic accident in Goiânia, Brazil, however, shows that some forms of radiological attack could kill tens or hundreds of people and sicken hundreds or thousands. Nevertheless, contrary to popular belief, RDDs are not weapons of mass destruction. The authors recommend several policies and actions to reduce the threat of RDD attack and increase the ability of the Federal Government to cope with the consequences of one. With improved public awareness and ability to respond, it should be possible to strip RDDs of their power to terrorize."
Defense Horizons No. 38
National Defense University. Center for Technology and National Security Policy: http://www.ndu.edu/inss/press/DefHor.html