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Number 136, March 1998

Radiological Dispersal Devices*Assessing the Transnational Threat*
by James L. Ford
Conclusions
- 
The Defense Science Board Summer Study    report recognizes a "new and ominous trend—a transnational threat with a    proclivity towards much greater levels of violence." The report states that    transnational groups have both access to, as well as the motivation to use, weapons of    mass destruction (WMD). Military and civil defense planners are increasingly concerned    about possible state and non-state use of radiological dispersal devices (RDD) against    U.S. forces and population centers abroad and at home.

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Practically any state or non-state    actor can build and detonate RDDs as technological barriers have fallen and radiological    materials have become more plentiful. However, weapons design experts contend that the    physical threat from these RDDs may be overstated.

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The psychological and political    effects of RDD use are not well understood and are potentially more significant than the    lethality effects of such use.

- 
While RDDs may not be well suited as    "military weapons" in the classic sense, the use of RDDs could be powerfully    coercive and could trigger enormous political reactions within host countries or among    allies in a coalition. These reactions could produce major strategic consequences for the    military campaign.

- 
With protective and decontamination    equipment, and training, U.S. forces should be able to withstand the physical effects of    most RDDs. At home, U.S. civil defense planners—including first responders being    trained under the Nunn-Lugar-Dominici initiative—must also be prepared to deal with    the RDD threat.

***"As the newmillennium approaches, the United States faces a heightened prospect that regionalaggressors, third-rate armies, terrorist cells, and even religious cults will wielddisproportionate power by using—or even threatening to use—nuclear, biological,or chemical weapons against our troops in the field and our people at home."**
Statement of Secretary of Defense William S. Cohen in the Preface tothe Defense Science Board’s 1997 Summer Task Force Final Report, October 1997.
**Radiological Dispersal Devices Defined**
The Department of Defense (DOD) defines an RDD as, "any device,including any weapon or equipment, other than a nuclear explosive device, specificallydesigned to employ radioactive material by disseminating it to cause destruction, damage,or injury by means of the radiation produced by the decay of such material." Almostany radioactive material can be used to construct an RDD, including fission products,spent fuel from nuclear reactors, and relatively low-level materials, such as medical,industrial and research waste. Weapons grade materials (i.e., highly enriched uranium orplutonium) are not needed although they could be used. 

An RDD is designed to scatter radioactive debris over a wide area,thereby contaminating it and possibly causing casualties through radiation sickness, aswell as denying its use to military forces or others for some period of time. According toa recent DOD report, the RDD threat is threefold: the blast and fragmentation effects fromthe conventional explosive, the radiation exposure from the radioactive material used, andthe fear and panic that its use would spread among the target group or population. Thispaper examines this threat and differentiates the *physical* from the *psychological*—andtherefore political—impact on a targeted population.
**Background**
The possibility of employing radioactive materials as a weapon wasfirst considered during World War II. In 1941, the National Academy of Sciences proposedradiological warfare as a military application of atomic energy. In its report, theAcademy’s first option was the "production of violently radioactive materials .. . carried by airplanes to be scattered as bombs over enemy territory." AfterBritish physicists demonstrated the technical feasibility of nuclear explosive weapons,attention quickly turned to their development throughout the remainder of the war. In1946, the United States conducted the Operation Crossroads nuclear weapons tests at BikiniAtoll in the Marshall Islands. The widespread contamination of ships used in these testsgave dramatic evidence of the potential of so-called radiological warfare. In 1947, theDefense Department began creating panels of experts to study the offensive and defensiveaspects of what it termed "Rad War." This led to an active test program,including releases of radiation into the atmosphere in the 1940s and 1950s. The results ofthese early experiments showed that while RDDs were not effective as battlefield weapons,such weapons could have a significant psychological effect. Yet, for the next fourdecades, there was little documented interest in developing radiological weapons.

Recent concerns with an RDD threat center on both state and non-stateactors. According to Western press reports in January 1991, Iraq claimed to have"secret" or "unusual" weapons that could kill tens of thousands of itsfoes. U.S. intelligence concluded that it was possible for Iraq to build a functioningRDD. An unclassified CIA report stated that Iraq could have obtained radioactive materialfrom research reactors and that it could disperse this material using a conventionalexplosive. The report concluded that an Iraqi RDD would not be a "militarilysignificant" weapon because it could not cause widespread radiation sickness, even ifused against unprepared and unprotected civilians in a city. However, the report alsoconcluded that any Iraqi use of an RDD would have a substantial psychological impact.
**Public Perceptions of the Threat**
Since the Gulf War, RDDs have received growing attention. Inparticular, a number of experts on international terrorism now believe that the threatfrom radiological weapons is real and growing. Increasingly, observers discount thelong-standing assumption that only states have the resources and expertise to develop oracquire such weapons. According to one report, Iranian agents are known to have tried tobuy nonfissile but radioactive nuclear material originating in the former Soviet Union.Moreover, sub-national and terrorist groups appear to be more likely to use them. The AumShinrykio sarin gas attack in Tokyo provides chilling evidence of terrorist willingness tokill large numbers of people. Indeed, the Aum Shinryko and subnational groups such as theChechens are known to have pursued development of RDDs. In November 1995, Chechen rebelsplaced a 30-pound container of radioactive cesium in a Moscow park—perhaps the mostrecent manifestation of an adversary’s willingness to use an RDD to achieve itsgoals.

Today, popular but sometimes inaccurate characterizations of the RDDthreat focus on the danger of radiation effects from detonation, the relative ease andready availability of radiological materials needed to construct such a device, and thereadiness of potential adversaries to do so. A recent article in *Foreign Policy*notes that, "[Some] have pointed out that if a simple radiological device had beenused in conjunction with the World Trade Center explosive, large areas of lower Manhattanwould still be uninhabitable." This article also underscores the relative ease withwhich the technical know-how, materials, and equipment to make RDDs can be acquired. Anarticle in *American Legion* points out that the danger from RDD terrorism might infact be greater "because of the relative ease with which terrorists could obtainradioactive materials, such as an x-ray machine from a dentist’s office, irradiatedmaterials from a hospital, radioactive matter from medical laboratories or constructionsites, and even linens from a cancer treatment facility." Many such claims are oftenoverstated and could be misleading.**
**How the Experts See It**
Notwithstanding popular perceptions, the physical effects of an RDD aredependent on several factors, but the *type*and the *amount*of radioactivematerial used in any device are especially critical. Current DOD studies underscore thevast difference in lethality produced by different types of radioactive materials. Forinstance, compare the effects of two different RDDs detonated at the Washington Monumentwith 100 pounds of high explosives. One device, a man-pack RDD, contains 5,000 curies ofcobalt-60 (Co-60); the second device, a truck-delivered RDD, carrying 50 kilograms ofbundled, not ground, one-year-old spent fuel rods. 

An RDD constructed using Co-60 would produce a maximum dosage at thepoint of detonation of 12 rem (Roentgen Man Equivalent), resulting in no radiation relateddeaths. In marked contrast, the RDD made from spent reactor fuel would result in a maximumdosage at the point of detonation of 3,064 rem (six times the lethal dosage). Thedetonation could produce a circle of potential lethal dosage extending about a kilometerto the Washington waterfront, and, a significant amount of radioactive material wouldremain at the detonation site. Clearly these two RDDs would produce very different *physical*effects, the second far more lethal than the first.

National laboratory scientists generally hold that construction and useof a physically effective RDD is more difficult than popularly assumed. States andsub-national groups would have to overcome significant technical difficulties to constructand effectively deliver an RDD on target. While it is possible for a state or even asubnational group to acquire materials for an RDD, it is difficult to assemble enoughhighly radioactive material to produce mass casualties or to achieve wide area denial.Even if a sufficient amount of the right material can be acquired, the handling ofgamma-emitting radioactive substances becomes very difficult due in part to the heatgenerated by large quantities of such material and the extreme exposure hazard from theintensity of the radiation. These substances require heavy shielding to protect handlersfrom overexposure and death. For example, the WWII Radioactive Subcommittee estimated thata bomb carrying 10,000 curies (enough to contaminate 250,000 square feet of openfields—approximately 5.7 acres) would require 310 pounds of lead to protect thosehandling the device. In addition, the radioactive material would have to be ground to adust of 5-micron-size particles and then mixed with an inactive solid material to enhancedispersion and increase the inhalation hazard. Lastly, the effects would be highlydependent on local weather conditions and terrain. These early experiments showed thatcities, or build-up areas, would require "something approaching 100 times greaterconcentration" because structures would absorb a large fraction of the radiation. Asa result of these early studies, the U.S. government concluded that RDDs were not a"militarily useful weapon."

In a February 1991 unclassified Defense Intelligence Agency report onpossible Iraqi delivery of radioactive material in a SCUD warhead, the authors concludedthat they could foresee no case in which such an RDD would be "militarilysignificant." They based this assessment on the fact that U.S. forces in the theaterhave equipment and training for operations in a nuclear environment, "an environmentthat an RDD does not even approach." Standard issue NBC gear provides excellentpractical protection, especially when combined with proper radiation monitoring andexposure time limitations. Although it would be impossible to predict the precise degreeof contamination without a detailed knowledge of the Iraqi radioisotope inventory, anyexpected dispersal pattern would produce only small areas of relatively high concentrationand large areas of much weaker concentration. In no circumstances, according to thisanalysis, would an Iraqi RDD be expected to produce an area of immediate lethality hazard.Military forces in the area could carry out an effective cleanup by washdown andscrapedown of contaminated surfaces, thus allowing operations to resume. Permanentcivilian residence in contaminated areas may be precluded, however, by residual activitythat would result in dangerous dosages of accumulated radiation exposure.
**The Threat: Perceptions Versus Reality**
The perception that practically any state or non-state actor can buildand detonate RDDs may well be coming true. However, the perception that all RDDs will havemajor *physical*effects is flawed. Experts contend that public commentators haveoverstated the ease of constructing and deploying an RDD that could cause mass casualtiesand deny an area’s use for a lengthy period of time. Acquiring a sufficient amount ofhighly radioactive material (such as spent reactor fuel), constructing the device withoutoverexposure to radiation in the process, effectively delivering the device on target, andachieving the necessary lethality to kill targeted personnel in the area are tasks beyondthe capability of most non-state actors. U.S. research and experimentation over 50-plusyears indicate that lethal RDDs are not easy to build. Most RDDs that non-state actors arelikely to build would not be effective in producing mass casualties or denying area use.The intelligence community has indicated that this may have been the Iraqi conclusion aswell, and at least one reason why Iraq did not use RDDs in the Gulf War of 1991. Ofcourse, fear of retaliation may also have been a major factor. 

On the other hand, it is true that almost any use of an RDD could havea tremendous psychological—and therefore political—impact. Thus, even crude RDDsmight meet some state’s or terrorist group’s objective, particularly if thatobjective were to create panic, to disrupt (or slow down) military operations, or to bringpublic pressure on political leaders to change a course of action. Imagine the politicalconsequences that could have resulted from the detonation of any RDD in the Saudi port ofAd Damman during the Desert Shield buildup in 1991 and the following news broadcast.
*"We interrupt our regular  programming with news of a radiological weapons attack against U.S. and coalition forces  in Saudi Arabia only hours ago. Early reports indicate that dozens may be incapacitated by  radiation overdose and hundreds or thousands of troops, as well as the local population,  may be at risk."*
What would have been the reactions of U.S. and coalition militaryforces in the target area? The local Saudi population? The American public and that of theother coalition countries? The U.S., Saudi and other coalition country leaders? 

In addition, a partial list of military concerns would certainlyinclude the following: How would troops in the target area have been affected—anyfatalities, radiation exposure or need for evacuation? Would there be special medical orhospitalization requirements? What would have been the decontamination and cleanuprequirements for personnel, facilities and equipment in the area? Could it have been donequickly with local assets, or would there have been delays in getting the proper equipmenton site? Could personnel, facilities and equipment have been put back into serviceimmediately? How long would the Desert Shield military mobilization have been delayed?Were there alternate ports that could have been used? 

At the very least, RDD use will inject the uncertainty of war known as"Clausewitzian friction" into any situation and distract troops from their focuson the mission. Psychologically, such an act could demoralize troops and sap theirfighting spirit and thus reduce their effectiveness in combat. Even more important, RDDuse is a potentially powerful psychological tool and could trigger enormous politicalreactions within any one country or amongst several countries, including allies orcoalition partners. 
**Recommendations**
National leaders recognize that states and terrorist groups may acquirethe wherewithal to construct and deploy weapons of mass destruction, including RDDs. TheDefense Science Board’s 1997 Summer Study concluded that DOD should treattransnational threats as a major Department mission and outlined a response strategy fordealing with them, which includes: 
- Military tasks to protect against RDD use include assuring armed    forces preparedness to conduct operations in a contaminated environment by addressing    training, decontamination requirements, passive defense equipment, safety concerns and    exposure guidelines.  
- Civilian tasks include educating government officials and the public    to promote a better understanding of the threat, and how to respond.
Senior military and civilian officials    should include this topic on international agendas with allied and friendly countries, in    order that planning, education and training in those countries can be coordinated with our    own.

James L. Ford is a Senior Visiting Fellow at National DefenseUniversity’s Center for Counterproliferation Research, on detail from the Departmentof Energy. He can be reached at (202) 685-4207. 

The Strategic Forum provides summaries of work by members and guests of the Institutefor National Strategic Studies and the National Defense University faculty. These includereports of original research, synopses of seminars and conferences,the results ofunclassified war games, and digests of remarks by distinguished speakers.

Editor in Chief - Hans Binnendijk

Editor - Jonathan W. PierceNOTE

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