Project Emerald : A dirty bomb, or radiological weapon, is a source (Cesium-۱۳۷)

Project Emerald : A dirty bomb, or radiological weapon, is a source (Cesium-137)

A "dirty bomb," or radiological weapon, is a device that combines nuclear materials with conventional explosives. The explosion itself is conventional—it is not a nuclear blast that releases vast amounts of energy through atomic fission—yet it is powerful enough to disperse radioactive material. Since the explosion is not as massive as that of a nuclear bomb, it is unlikely that radioactive material would reach the upper atmosphere or result in radioactive fallout. A dirty bomb is neither a nuclear weapon nor a nuclear explosive device. However, the impact of a dirty bomb in terms of the anxiety and fear it generates can be immense; for this reason, it is also referred to as a weapon of mass disruption.

A Cesium-137 source can be extremely dangerous; if its dust were to disperse across an area and contaminate more than 400 people over the following two weeks, those exposed would lose their lives. Mitigating further harm would require testing over 100,000 people, and the affected region would face long-term social stigma. Another comparison involves examining the disaster. Although this situation differs significantly from a "dirty bomb" scenario, it demonstrates how radioactive materials—specifically cesium—adhere to the urban environment and reveals the consequences for the surrounding population.

Prior to an attack, a radiological source may emit radiation, though such radiation would likely affect only those in the immediate vicinity. In the immediate aftermath of an attack, the injured must be attended to and stabilized before decontamination begins; simultaneously, emergency responders must take necessary personal protection measures.

Since debris can serve as a focal point for radioactive material, the cleanup process must commence as soon as possible. Any cloud generated by the explosion has the potential to carry radioactive particles and disperse materials that adhere to buildings, lawns, and streets. Monitoring of the cloud is essential to identify which areas are contaminated and require decontamination.

Caesium-137 is not widely used for industrial radiography because it is difficult to obtain a material with a very high specific activity and a well-defined (and small) form, as caesium from spent nuclear fuel contains the stable caesium-133 as well as the long-lived caesium-135. Isotope separation is very expensive compared to cheaper alternatives. Also, caesium sources with higher specific activity are usually made from highly soluble caesium chloride (CsCl). As a result, if a radiography source is damaged, the risk of radioactive contamination is high. Water-insoluble caesium sources can be made (e.g. with ferrocyanides), but their specific activity will be lower. Other chemically inert caesium compounds include caesium-aluminosilicate glasses similar to the natural mineral plosite. The latter has been used in the demonstration of chemically stable, water-insoluble forms of nuclear waste for disposal in deep geological repositories. A large amount of emitter damages the image quality in radiography.