Predict and Manage Terrorist Events

US federal agencies ability to predict and manage terrorist events

Us Federal Agencies Ability To Predict And Manage Terrorist Events

Many fear a terrorist attack with a radiological dispersal device (RDD). RDDs may scatter radioactive material with an explosive (a "dirty bomb") or other means. Radioactive atoms are unstable; as they decay? they emit electromagnetic radiation or subatomic particles that can damage cells. Many legitimate activities worldwide use such material. Dealing with RDDs involves controlling sources? detecting radiation? and preparing for and responding to an attack. This report will be updated. "Nuclear and Radiological Terrorism?" in the CRS electronic briefing book on terrorism? tracks developments.

This report does not address nuclear power-related issues; see CRS Report RS21131? Nuclear Powerplants: Vulnerability to Terrorist Attack Sources of Radioactive Material. (U.S. Department of Homeland Security? 2004) Radioactive sources have many beneficial uses; millions are used worldwide. Sources with a tiny fraction of a Curie? such as household smoke detectors? do not pose a terrorist threat? but a source with even a few Curies may be of use for an RDD. While hundreds of radioactive isotopes exist? only a few isotopes? all produced in nuclear reactors? are of concern for RDDs. Isotopes of special concern? typical sources? and Curies per source? include cesium-137 (half-life 30. years)? used in external beam radiation devices to treat cancers (13?500 Ci) and equipment to monitor wells for oil (0.-2. Ci); and cobalt-60 (half-life 5. years)? used in industrial radiography (3-250 Ci) and cancer therapy (0.-0. Ci). Such sources often have little security because they are small? have modest amounts of shielding so they can be used in the field? and do not have enough radiation to be self-protected. They are sometimes abandoned.

In contrast? terrorists would find isotopes with very short half lives (hours or less) of little use because the radiation could decay to low levels before the material could be used? while those with long half-lives (millions of years) emit radiation very slowly and would do little damage unless inhaled. There is legitimate global commerce in radioactive materials of concern? but also potential for fraudulent purchases and theft during shipment or use? and problems of disposing of sources no longer wanted. (U.S. Department of Homeland Security? 2004)

Alternative Designs. The term "dirty bomb" may have led the media to focus on a device in which powdered radioisotope surrounds chemical explosive. Many terrorist groups would have the skill and materials to make the explosive part of the device; it would be somewhat harder for them to obtain the radioactive material and convert it to powdered form. Terrorists could also scatter radioactive material without an explosive.

Effectiveness. An RDD's effectiveness depends on many factors. (1) Some isotopes do more harm than others? and some elements (including their radioisotopes)? such as cesium? bond strongly to concrete and asphalt. (2) Smaller particles disperse more easily and are more readily inhaled? but may be harder to make. (3) Using more material increases physical ...