Large hydraulic shears can be employed, but they still only reduce the bulk of the contaminated material, not the level of radioactivity. A method was needed that safely and effectively decontaminated the materials and reduced to an absolute minimum the amount of radioactive waste that would require further transportation, treatment and disposal. Knight Armour Environmental Services, Inc. pioneered a solution that could achieve both these aims. A contaminated piece of equipment is not inherently radioactive. The radioactivity is in the form of particles that are somehow bonded, embedded or adhered to the surface of the equipment.
Carbon dioxide provides an ideal solution.
This literally blasts the contaminant off of the surface into the rebounding flow of CO 2 gas, which is then captured in a smooth laminar flow of air that flushes the suspended radioactive particles into a two stage HEPA filter where they are removed. To keep the amount of suspended particles in the containment area to an absolute minimum the entire atmosphere is completely changed every 20 seconds. Unlike a stream of water or some other flushing fluid, the CO 2 gas is inert and cannot react with the contaminants, therefore the cleaned gas can be simply allowed to pass through the filters. There are no other contaminated solvents or liquids to dispose of. The decontamination is carried out in a negatively pressurized and sealed chamber so that no radioactivity can escape.