By Scott Stewart
The government of Kazakhstan announced Sept. 2 that it was searching for a container of radioactive cesium-137 that fell off a truck in the western part of the country. Such radioactive sources are commonly used for medical, commercial and industrial purposes, and from time to time are reported lost or stolen. The material was recovered, but the incident highlighted the risks of radioactive material falling into the wrong hands.
Occasionally, the loss or theft of a radioactive source will result in an accidental dispersal of radioactive material. For example, in 1987, a small radiotherapy capsule of cesium chloride salt was accidentally broken open in Goiania, Brazil, after being salvaged from a radiation therapy machine at an abandoned health care facility. Over the course of 15 days, the capsule containing the radioisotope was handled by a number of people who were fascinated by the faint blue glow it emitted. Some victims reportedly smeared the substance on their bodies. These people then further spread the radiation to various parts of the surrounding neighborhood, and some of it was even taken to nearby towns. In all, more than 1,000 people were contaminated during the incident, and some 244 were found to have significant radioactive material in or on their bodies.
In another case, this time in a slum outside New Delhi, India, eight people were admitted to hospitals in 2010 for radiation exposure after a scrap dealer dismantled an object containing cobalt-60. The cleanup operation was easier in the Indian incident because, unlike the cesium in Goiania, the radioactive material was in metallic form and in larger pieces.
Stolen radioactive material is sometimes released accidently, but it could also be used to make dirty bombs or other radiological dispersal devices intended to cause harm. However, this threat is sometimes dramatically hyped, creating unnecessary fear and panic.
Even if the radioactive source lost in Kazakhstan had fallen into the wrong hands, it is highly unlikely that it could have been transported to the United States or Europe for an attack. Nevertheless, this is a good opportunity to once again place the threats -- and very real limits -- of dirty bombs in perspective.
Radiological Dispersal Devices
A dirty bomb is a type of radiological dispersal device (RDD), and RDDs are, as the name implies, devices that disperse a radiological isotope. Depending on the motives of those planning the attack, an RDD could be a low-key weapon that surreptitiously releases aerosolized radioactive material, one that dumps out a finely powdered radioactive material or something that dissolves a radioactive material in water. Such methods are intended to slowly expose as many people as possible to the radiation for as long as possible without becoming detected. Unless large amounts of a very strong radioactive material are used, however, the effects of such exposure are limited. To cause adverse effects, radiation exposure must occur either in a very high dose over a short period of time or in smaller doses sustained over a longer period. This is not to say that radiation is not dangerous, but only that small amounts of radiation exposure do not necessarily cause measurable harm. In fact, people are commonly exposed to heightened levels of radiation during activities such as air travel and mountain climbing.
By their very nature, RDDs are prone to be ineffective. To maximize the harmful effects of radiation, victims must be exposed to the highest possible concentration of a radioisotope. But by definition and design, RDDs dilute the radiation source, spreading smaller amounts of the substance over a larger area. Additionally, the use of an explosion to spread the radioisotope alerts the intended victims, who can then evacuate the affected area and be decontaminated. These factors make it very difficult for an attacker to administer a deadly dose of radiation through a dirty bomb.
It is important to note that a dirty bomb is not a nuclear device, and no nuclear reaction occurs. A dirty bomb will not produce an effect like the nuclear devices dropped on Hiroshima or Nagasaki. A dirty bomb is quite simply an RDD that uses explosives to disperse a radioactive isotope; the only blast effect or damage produced is from conventional explosives and not from the radioactive material itself. In a dirty bomb attack, radioactive material is spread in an obvious manner, causing mass panic. In other words, the RDD is a weapon intended to create fear and terror.
The radioisotopes that can be used to construct an RDD are fairly common. Those materials considered most likely to be used in an RDD, such as cobalt-60 and cesium-137, have legitimate medical, commercial and industrial uses. Organizations such as the International Atomic Energy Agency warn that such radioisotopes are readily available to virtually any country in the world, and they are almost certainly not beyond the reach of even moderately capable non-state actors. Indeed, given the ease of obtaining radiological isotopes and the simplicity of constructing a dirty bomb, it is surprising that we have not yet seen one successfully used in a terror attack, especially considering jihadist groups in Iraq, Syria and Libya have captured cities that likely contain radioactive sources. In light of this, let's examine what effectively employing a dirty bomb would entail.
Creating An Effective Dirty Bomb
Like nonexplosive RDDs, unless a dirty bomb contains a large amount of very strong radioactive material, the radiological effects of the device are not likely to be immediate or dramatic. In fact, the explosive effect of the RDD is likely to kill more people than the device's radiological effect. Moreover, the need for a large quantity of a radioisotope not only creates challenges for obtaining the material but also means the resulting device would be large and unwieldy -- and therefore difficult to smuggle into a target such as a subway or stadium.
In practical terms, a dirty bomb can produce a wide range of effects depending on the size of the improvised explosive device (IED) and the amount and type of radioactive material involved. (Powdered radioisotopes are easier to disperse than materials in solid form.) Environmental factors such as terrain, weather conditions and population density also play an important role in determining the effects of such a device.
Significantly, while the radiological effects of a dirty bomb may not be instantly lethal, the radiological impact of an RDD would likely affect an area larger than the kill radius of the IED itself and persist far longer. The explosion from a conventional IED is over in an instant, but radiation released by an RDD can remain for decades unless the area is decontaminated. While the radiation level may not be strong enough to affect people exposed briefly during the initial explosion, the cumulative effects of such radiation could prove very hazardous. Again, the area contaminated and the ease of decontamination depends on the type and quantity of the radioactive material used. Materials in a fine powdered form are easier to disperse and harder to clean up than solid blocks of material. In any case, it would be necessary to evacuate people from the contaminated area, and people would need to stay out of the area until it could be decontaminated, a process that could prove inconvenient and expensive.
Though dirty bombs are not truly weapons of mass destruction like nuclear devices are, they are frequently referred to as "weapons of mass disruption" or "weapons of mass dislocation" because they can temporarily render areas uninhabitable. The expense of decontaminating a large, densely populated area, such as a section of London or Washington, would be quite high. This cost also makes a dirty bomb a type of economic weapon.
Historical Precedents
The world has not yet witnessed a successful dirty bomb attack by a terrorist or militant group. This does not necessarily mean groups are not interested in using radiological weapons. Chechen militants have perhaps been the most active in the realm of radioactive materials. In November 1995, Chechen militants under the command of Shamil Basayev placed a small quantity of cesium-137 in Moscow's Izmaylovsky Park. Rather than disperse the material, however, the Chechens used the material as a psychological weapon by directing a TV news crew to the location, thus creating a media storm and fostering public fear. It is believed the material in this incident was obtained from a nuclear waste or isotope storage facility in the Chechen capital of Grozny.
In December 1998, the pro-Russian Chechen Security Service announced it had found a dirty bomb consisting of a land mine combined with radioactive materials next to a railway line frequently used to transport Russian troops. It is believed that Chechen militants planted the device. In September 1999, two Chechen militants who stole highly radioactive materials from a chemical plant in Grozny were incapacitated after carrying the container for only a few minutes each; one reportedly died later. This highlights another hurdle to producing an effective dirty bomb: The strongest radioactive material is dangerous to handle, and even a suicide operative might not be able to move and employ it without being disabled first.
Still, none of these Chechen incidents provide a clear example of what a dirty bomb detonation would actually look like. To do this, we need to look at incidents where radiological isotopes were dispersed by accident, such as the Goiania and New Delhi incidents mentioned above. Despite widespread contamination and sustained exposure to the radioactive material in the Goiania case, only four people died from the incident. However, in addition to the human toll, the cleanup operation in Goiania cost more than $100 million. Many houses had to be razed and substantial quantities of contaminated soil had to be removed from the area.
Perhaps the largest radiological dispersal incident in history was the 1986 Chernobyl nuclear disaster in northern Ukraine, in which a 1-gigawatt power reactor exploded. It is estimated that more than one hundred times the radiation of the Hiroshima bomb was released during the accident -- the equivalent of 50 million to 250 million grams of radium (55 to 275 tons). More than 40 different radioisotopes were released, and there was a measurable rise in cesium-137 levels across the entire European continent. No RDD could ever aspire to anything close to such an effect.
Chernobyl wrought untold suffering, and estimates suggest that it may ultimately contribute to the deaths of 9,000 people. But many of those affected by the radiation are still alive more than 20 years after the accident. While Stratfor by no means seeks to downplay the tragic human or environmental consequences of this disaster, the incident is helpful when contemplating the potential effects of a dirty bomb attack. Despite the incredible amounts of radioactive material released at Chernobyl, only 31 people died in the explosion and its immediate aftermath. Today, 5.5 million people live in the contaminated zone. Many are within or near the specified EU dosage limits for people living close to operational nuclear power plants.
It is this type of historic example that makes us so skeptical of claims that a small dirty bomb could cause hundreds or even thousands of deaths. Instead, the most strategic consequences of this sort of destruction are economic. By some estimates, the Chernobyl disaster will ultimately cost well in excess of $100 billion. Again, in our opinion, a dirty bomb should be considered a weapon of disruption -- one that could cause significant economic loss but that would not cause mass casualties or any real mass destruction.
Fighting Panic
Analytically, based on how easily dirty bombs can be manufactured and the historical interest militants have shown in them -- which ironically, may be partly caused by the hype around the RDD threat -- it is only a matter of time before militants successfully employ one. Because the contamination created by such a device can be long-lasting, more rational international actors would probably prefer to detonate such a device against a target outside their own country. In other words, they would lean toward attacking a target within the United States or Europe rather than against an American or European embassy in their home country.
Considering that it is not likely to produce mass casualties, a dirty bomb attack would likely be directed against a highly symbolic target, such as one representing the economy or government of a Western nation, and would be designed to cause the maximum amount of disruption at the target site. The device would not destroy these sites but would limit access to them for as long as it took to decontaminate them.
As noted above, we believe it is possible the panic created by a dirty bomb attack could well kill more people than the device itself. This analysis is necessary because people who understand the limitations of dirty bombs are less likely to panic than those who do not. An important way to avoid panic is to carefully think about such an incident before it happens and to craft a contingency plan for your family and business. Contingency plans are especially important for those who work in close proximity to a potential dirty bomb target, but they are useful in any disaster, whether natural or man-made, and are something that should be practiced by all families and businesses. Such knowledge and planning will enable individuals to conduct an orderly and methodical evacuation of an affected area, allowing them to minimize their exposure to radioactivity while also limiting their risk of injury or death due to mass hysteria. Although a dirty bomb attack could well be messy and disruptive, it does not have to be deadly.
COPYRIGHT: STRATFOR.COM
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