ABSTRACT
The work of homeland security delves into the nature of risk, whether at airports or busways, public courthouses, or national monuments. Risk constitutes what might happen or what is likely to happen given a certain set of circumstances. Risk is what can go wrong. The Department of Homeland Security (DHS) defines the nature of risk by three principal variables: threat, or the likelihood of a type of attack that might be attempted; vulnerability, or the likelihood that an attacker would succeed with a particular attack method; and consequence, or the potential impact, individually or collectively, of a particular attack. Infrastructure of every variety needs constant vigilance in the matter of threat, from its original construction phase to its maintenance. Most radioactive materials lack sufficient strength to present a significant public health risk once dispersed, and the materials posing the greatest hazard would likely infect the terrorists themselves.
