The TOPOFF 4 Full-Scale Exercise

The TOPOFF 4 Full-Scale Exercise was based on National Planning Scenario 11 (NPS-11). The scenario began as terrorists, who have been planning attacks in Oregon, Arizona, and the U.S. Territory of Guam, successfully bring radioactive material into the United States. The first of three coordinated attacks occured in Guam, with the simulated detonation of a Radiological Dispersal Device (RDD), or “dirty bomb,” causing casualties and wide-spread contamination in a populous area near a power plant. Similar attacks occured in the hours that follow in Portland and Phoenix.

An RDD is not the same as a nuclear attack. It is a conventional explosive that, upon detonation, releases radioactive material into the surrounding area. Although it does not cause the type of catastrophic damage associated with a nuclear detonation, there are severe rescue, health, and long-term decontamination concerns associated with an RDD. Real weapons were not be used in the scenario, but the response will be mounted as if they had been.