Dispersive Devices Subcommittee

Terrorist or other radical organizations may attempt to use radioactive materials to further their social, economic or political goals. The Dispersive Devices Subcommittee's goal is to provide information about these dispersive devices to help education the public and support emergency response organizations.

The Chairperson of the Dispersive Devices Subcommittee is:

James Hardeman

CRCPD's Handbook for Responding to a Radiological Dispersal Device First Responder's Guide

Article by Dr. Robin McFee Homeland Security:Is this 2008 or 2001? Seven Years and Still Playing Catch Up!

Dispersive devices are commonly referred to as RDDs which stands for Radiological Dispersal Devices. How many types of RDDs can be made? The answer lies in the creativity of the deranged mind. Three common types of RDDs are presented below:

1. A high energy radioactive source that's strapped to the bottom of a park bench, or left in a busy public location.
Availability: Significant radioactive sources are not readily available.
Health Impact: Can deliver a significant radiation dose to a relatively small number of people.
Psychosocial Effects: The device is insidious, but the effect on society would probably be low to moderate because: (1) it's likely to expose a small number of individuals and (2) persistent contamination is unlikely.
Discovery and Remediation: High energy sources are generally easy to detect and remediate.

2. A radioactive liquid dispersed from a moving vehicle or into a body of water.
Availability: Significant concentrations of radioactive liquids are not easily attained.
Health Impact: Generally low to moderate. Large numbers of individuals may be exposed if dispersed into a drinking water source but dilution would lower each individual's personal exposure.
Psychosocial Effects: Can be significant. Large numbers of individuals may be exposed and they may overreact to an unfamiliar hazard. Unexposed individuals, concerned about their exposure potential may overwhelm available resources.
Discovery and Remediation: May be difficult to detect. Remediation may involve significant resources.

3. A conventional explosive used to disperse radioactive material across a target area also known as a Dirty Bomb.
Availability: Small sources can be obtained from many commercial sources including consumer products like smoke detectors or exit signs. Significant sources are not as easily attained.
Health Impact: In most instances, the conventional explosive itself would have more immediate lethality than the radioactive material. At the levels created by most probable sources, not enough radiation would be present in a dirty bomb to kill people or cause severe illness.
Psychosocial Effects: Significant. Large numbers of individuals may be exposed and they may overreact to an unfamiliar hazard. Psychosomatic symptoms may be present in the unexposed and their quest for evaluation and treatment may overwhelm existing resources.
Discovery and Remediation: Prompt response and discovery is likely. Remediation, to pre-event background radiation levels (if possible) is likely to involve significant efforts and resources.

Size Does Matter! Small radioactive sources are likely to affect a localized area and cause relatively low doses to members of the pubic, while large sources are more likely to cause widespread contamination and significant radiation doses.

Most injuries from a dirty bomb would probably occur from the heat, debris, radiological dust, and force of the conventional explosion used to disperse the radioactive material, affecting only individuals close to the site of the explosion. At the low radiation levels expected from an RDD, the immediate health effects from radiation exposure would likely be minimal.

Dirty Bombs are not nuclear weapons. A nuclear bomb creates an explosion that is thousands to millions of times more powerful than a conventional explosive that might be used in a dirty bomb. It's been said that nuclear warheads are weapons of mass destruction while dirty bombs are weapons of mass disruption.

So what helps protect us from RDDs?

1. Effective Radioactive Material Security. Federal and State agencies insist that radioactive source owners keep the materials locked up securely - when not in use or under direct surveillance. This level of security helps ensure that sources do not fall into the wrong hands.
2. Routine Use of Radiation Monitoring Equipment will help detect clandestine high energy radioactive sources especially during high profile events and large citizen gatherings.
3. Reporting Suspicious Activities to the appropriate authorities.
4. Good Hygiene. Simple soap and water cleaning and good housekeeping practices can be very effective in reducing and removing radioactive contamination and will significantly reduce radiation exposure from dispersed radioactive materials.

Additional information about RDDs and related emergency response information is available from:

1. The National Academies and the Department of Homeland Security information about radiological terrorism, RDDs and emergency response.

2. The US Department of Homeland Security Information about dirty bombs, nuclear, chemical and biological terrorism.

3. The US Nuclear Regulatory Commission Dirty bomb fact sheet.

4. The New York State Department of Health Dirty bomb information.

5. The Radiation Emergency Assistance Center/Training Site. Radiological emergency response and training.

Individual members of the Society have suggested these websites as useful references for additional information on the subject of RDDs and emergency response to radioactive material incidents.

The Center for Strategic and International Studies (CSIS), a non-partisan group specializing in research on issues affecting domestic and international security, have published two reports on radiological and nuclear terrorism. Wild Atom; Nuclear Terrorism is a report a 1996 war game concerning the detonation of a terrorist nuclear weapon. The Nuclear Black Market reports on the history of the international black market in nuclear and radiological materials.

What is the potential contamination levels and radiation exposures resulting from the dispersal of an explosive RDD. The Lawrence Livermore National Laboratory developed a computer code to model this dispersion. Hotspot is available on the LLNL website. The program RESRAD (developed at the Argonne National Laboratory) can be used to estimate exposures to people who may live in areas contaminated by radioactive materials following an RDD attack.