Tactical Implications of the 'Smoky Bomb' Threat

By Fred Burton
Jan. 2, 2007
SOURCE: http://www.stratfor.com/products/enhanced/login.php?err=3&prodid=&subid=&url=/products/enhanced/read_article.php?id=282464
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There has been a lot of concern during the past year over the threat posed by radiological dispersion devices, or RDDs. This concern exists not only in the media and among members of the public, but also in law enforcement and intelligence circles. The concept of an RDD, or "dirty bomb," is not new; it has been at the forefront of press coverage of terrorism and security, and of the public consciousness, since the May 2002 arrest of Jose Padilla, the so-called al Qaeda "dirty bomber."

As Stratfor has mentioned in previous analyses, media coverage of the RDD threat runs in cycles that ebb and flow, and it is based on newsworthy incidents. The most recent wave of media interest was generated by the assassination of former KGB officer Alexander Litvinenko, who was killed with radioactive polonium-210.

In an op-ed piece that appeared in The New York Times on Dec. 19, Peter D. Zimmerman, a nuclear physicist and a professor of science and security in the Department of War Studies at King's College London, discussed the terrorist threat posed by polonium and, more specifically, the way polonium-210 (or other radioisotopes that emit alpha radiation) could be used to make what he termed a "smoky bomb."

Studying Zimmerman's thesis in a tactical and historical context allows the smoky bomb threat to be placed in proper perspective and helps to highlight a number of common misconceptions involving RDD weapons: namely, that they are easy to obtain; that they are easy to deploy effectively; and that, when used, they always cause mass casualties.

The Smoky Bomb

An RDD is a device that releases or disperses radiation. This dispersal can be achieved through such means as hiding a highly radioactive source in a public place or by dumping a vial of powdered radioactive material from a tall building. In more complex but still relatively simple devices, material can be scattered by an explosive charge -- a dirty bomb -- or by dissolving it in water.

Zimmerman's smoky bomb concept envisions a device that disperses radiation through smoke that is inhaled into the victims' lungs. In sufficiently high concentrations, this smoke could produce acute radiation poisoning; in smaller doses, it could cause cancer and other long-term health problems. Getting the radioactivity into the victim's body via the lungs would mean that alpha radiation (which does not have much penetration power) could be used in place of more-penetrating gamma radiation -- which can affect people from outside their bodies. Alpha radiation sources are not as tightly controlled as gamma radiation sources, and many standard radiation detectors cannot see alpha radiation, meaning first responders might not recognize the threat.

Such a weapon would be more likely to take the form of an improvised incendiary device (IID) than an improvised explosive device (IED), since the IID would create more smoke to transport the radioactive particles. The force of an explosive device would tend to disperse the smoke and radiation farther and faster. An IID-based weapon would not be literally a smoky "bomb," but rather a smoke-emitting RDD.

At the tactical level, terrorists who want to employ smoke to disperse radioactive particles run into many of the same obstacles as do terrorists seeking to disperse deadly chemicals such as hydrogen cyanide gas. By its very nature, smoke rises and disperses, which could be helpful in spreading radioactive particles. However, it is difficult to achieve concentrations of radioactive smoke lethal enough to cause immediate casualties unless such a device is used in an enclosed area, such as a subway car or a building. Even in enclosed spaces, the historical examples of Aum Shinrikyo's many chemical weapons attacks demonstrate that it is difficult to obtain deadly concentrations of even very lethal substances. Outdoors, factors such as wind, precipitation and terrain could have a dramatic effect on the smoke generated by such a device, as could the ventilation and sprinkler systems found inside buildings -- systems designed to protect occupants from smoke and fire.

One other factor to consider in discussing polonium-210, used in the Litvinenko assassination, is that it has two different properties that can make it deadly -- its radiation and its toxicity. If it is ingested, as it was in the Litvinenko assassination, its toxic properties can be even more deadly than its radioactive properties. Furthermore, even after receiving a massive dose of the substance -- a dose far greater than almost any smoke-emitting RDD could ever deliver to its victims -- Litvinenko lingered on for 23 days; he did not die immediately.

The trail of polonium in the Litvinenko case has led all over Europe, and it appears that Litvinenko himself (and at least one of the suspects in the case) essentially might have functioned as a human RDD, spreading traces of polonium in his wake as he visited hotel rooms, apartments, restaurants, vehicles and airplanes. While this illustrates how readily radioactive substances such as polonium-210 can be dispersed over a large area, it also demonstrates that it is not always lethal.

Chernobyl

In spite of repeated media reports that RDDs are weapons of mass destruction that everyone wants to use, and that the components required to manufacture them are readily available, an RDD device has never been used successfully in a terrorist-type attack. If RDD weapons were truly as easy to produce and as effective as they are portrayed to be, they would be used more frequently. Since an actual smoky bomb has never been used as an RDD, perhaps the best example of a smoking disperser of radioactive material is Ukraine's 1986 Chernobyl disaster.

The explosion and resulting fire at Chernobyl have been called the greatest industrial disaster in the history of humankind. According to international health organizations, the reactor core released 100 times more radiation than the atom bombs dropped on Hiroshima and Nagasaki. In addition to the contamination that occurred in the area immediately around the facility, radiation also was spread over large parts of Scandinavia, Poland and the Baltic states, as well as southern Germany, Switzerland, northern France and England in the days following the accident.

The Chernobyl accident reportedly released between 50 million and 250 million curies of radiation. That radiation was composed of more than 40 different radionuclides, including cesium-137, iodine-131, strontium-90 and plutonium-241 -- much of it carried in the smoke that billowed from the fire that raged in the reactor. One curie is the equivalent of one gram of radium, so the accident resulted in the release of the equivalent of between 50 million and 250 million grams of radium (approximately 110,000 pounds to 551,000 pounds) -- far more than any aspiring dirty bomber could ever hope to incorporate into a device. In total, more than 55,000 square miles were contaminated with more than 1 curie of cesium-137, an especially small, particulate radioisotope.

However, despite this massive release of radiation -- including alpha, beta and gamma emitters -- the accident claimed only about 31 lives due to acute radiation exposure (the numbers are disputed; some sources say 30, others say 32). Many other victims reportedly have died from the long-term effects of radiation exposure, such as various types cancer, but the initial death toll was relatively small. While Chernobyl itself is somewhat isolated, the town of Pripyat, which was built especially for Chernobyl employees, had 45,000 residents at the time of the accident and was located only four kilometers from the reactor. There were a total of 76 settlements within a 30-kilometer radius of the reactor, and more than 350,000 people had to be evacuated and resettled due to radiation contamination. Nevertheless, even Chernobyl did not produce the immediate mass casualties of the 9/11 attack or the Madrid train bombings.

The Bottom Line on RDDs

The Chernobyl accident highlights the fact that, even with a massive release of radiation spread by smoke, an RDD will not always cause mass casualties. In spite of this, however, considering the ease with which a rudimentary RDD can be manufactured, we believe it is only a matter of time before one will be deployed. This will happen for no other reason than the aforementioned misconceptions about RDDs' simplicity and effectiveness, which likely will lead a "lone wolf" terrorist or grassroots jihadist cell to believe that RDDs are highly desirable and useful as weapons.

Because of the difficulty in obtaining the most dangerous radioactive materials (called gamma emitters), and the danger presented in working with materials such as cesium-137, it is likely that a terrorist would build an RDD with easier-to-obtain and less-dangerous materials called alpha and beta emitters. Polonium-210 is one example of an alpha emitter, but others, such as americium-241, are perhaps more common and are therefore more likely to be used. Americium-241 is used in some medical diagnostic devices and in a variety of industrial and commercial devices that measure density and thickness. Very small sources also are present in smoke detectors.

Like a dirty bomb, a smoke-emitting RDD would be a powerful psychological weapon intended to cause panic and a great deal of disruption -- that is, if the radiation is detected. The panic such a device would generate very well could cause more casualties than the device itself. If a serious and sophisticated terrorist group such as al Qaeda used an RDD, it would be to incite panic, capture the attention of press and make an economic impact -- not as an attempt to create mass casualties.

The radiological effects of a smoke-emitting RDD are broader than the killing radius of the device and can persist for a long time, depending on the radioisotope used. While the resulting radiation level might not be strong enough to affect people who are exposed briefly, the cumulative effect of the radiation in the contaminated area could prove very hazardous. (The size of this contaminated area depends on the type and quantity of the radioactive material used and the effect of environmental factors on the smoke.) Due to this contamination, it might be necessary to evacuate people from the contaminated area, and people might need to stay out of the area until it can be decontaminated -- a process that can be lengthy and expensive. This means that an RDD attack qualifies as an "economic attack" as well, and one that would fall squarely within al Qaeda's targeting criteria. Because of this contamination factor, terrorists most likely would employ such a device in the United States, United Kingdom or some other symbolic Western power and not in a Muslim country. Such a choice of targets also would guarantee the most media attention.

The possibility of an RDD attack, smoke-emitting or otherwise, once again underscores the importance of contingency planning -- especially for those who live or work near potential targets or in a symbolic city like New York, London or Washington. In the case of an RDD attack, it will be important to stay calm. Panic, as previously noted, potentially could kill more people than the device.

People caught in close proximity to the detonation site obviously should avoid breathing in the smoke, which can be a killer in any ordinary fire or bombing. Avoiding the smoke can best be accomplished by getting as low as possible and leaving the area as quickly (and as calmly) as possible. A commercially available smoke hood could aid greatly in an escape from the scene of an RDD attack and could literally be the difference between life and death in such a situation. A small flashlight also could prove invaluable.

The three most important things to remember about protecting oneself from radiation are time, distance and shielding. That means minimizing the time of exposure and maximizing the distance and the shielding between oneself and the radiation source.