THE US: Industrial and medical grade nuclear materials are in abundant supply and could be used by terrorists to build radioactive 'dirty bombs', writes Tom Clonan
The current arrest and detention of an al-Qaeda suspect in the United States has focused the world's attention on the concept of the radioactive "dirty bomb".
A radioactive "dirty bomb" consists of a conventional explosive device wrapped in radioactive material. Such a device could consist of a car bomb or suitcase bomb for example, containing plastic explosives surrounded by industrial or medical grade nuclear material. The effect of such a bomb on an urban area would be catastrophic - in economic and political terms.
For the assembly of such a weapon, plastic explosives such as Semtex and detonators are easily obtained. The next step for the terrorist would be to acquire radioactive materials. Weapons grade nuclear material would be very difficult for al-Qaeda operatives to obtain and smuggle into the United States or Europe. Such fissile materials are often easy to detect and difficult to transport. On the other hand, industrial grade and medical grade nuclear materials are readily available.
In the United States alone, up to two million industrial devices with a plethora of applications contain radioactive materials such as caesium and iridium. Examples of such industrial grade nuclear materials include the cobalt rods used to irradiate food and the caesium 137 used in moisture density gauges - (employed to measure the setting time of concrete).
In addition to industrial grade materials, there is an abundance of medical grade radioactive material throughout the US and Europe.
An example of this material would include the radioactive isotopes used in the treatment of cancer. Such materials, if packed into a truck or car loaded with plastic explosives could be readily delivered to any number of high profile targets in densely populated urban areas throughout the US and Europe.
Pellets of nuclear material such as caesium and iridium harvested from medical and industrial sources would function as radioactive shrapnel designed to disperse on detonation of the conventional explosives packed into the delivery vehicle.
The detonation of such a device would lead to the widespread radioactive contamination of a large area of a city. A truck bomb similar in size to the one detonated by Timothy McVeigh in Oklahoma, if loaded with radioactive materials, would have enormous consequences in a high rise urban environment such as New York for example.
In the aftermath of such an explosion, there would be an immediate mass evacuation of the civilian population from a wide area of the blast site.
The shock wave and prevailing winds would carry dust and aerosol particles of highly radioactive material over a wide area from the blast site.
It is estimated it would cost approximately €400 to decontaminate every cubic foot of such a contaminated area. In such a scenario the cultural, commercial and financial heart of a city would be contaminated and uninhabitable for several months, if not years. The political and economic cost of such an attack would be staggering.
In human terms, the initial blast might kill hundreds of innocent civilians.
Many more exposed to the radioactive materials released in the explosion would suffer serious health complications and cancers for many years thereafter.
In psychological terms, it is difficult to estimate the damage to the psyche of a nation that would be inflicted by such a terrorist strike.
This would be especially so in the US which heretofore has been relatively invulnerable to attacks on its towns and cities.
Dr Tom Clonan is a retired Army captain. He currently lectures in public relations at the School of Media, DIT.