Innovative technology summary report: Concrete grinder

The Flex concrete grinder is a lightweight, hand-held concrete and coating removal system used for decontaminating or stripping concrete surfaces. The US Department of Energy has successfully demonstrated it for decontaminating walls and floors for free release surveys prior to demolition work. The grinder is an electric-powered tool with a vacuum port for dust extraction and a diamond grinding wheel. The grinder is suitable for flat or slightly curved surfaces and results in a smooth surface, which makes release surveys more reliable. The grinder is lightweight and produces very little vibration, thus reducing worker fatigue. The grinder is more efficient than traditional baseline, tools at removing contamination from concrete surfaces (more than four times faster than hand-held pneumatic scabbling and scaling tools). Grinder consumables (i.e., replacement diamond grinding wheel) are more expensive than the replacement carbide parts for the scaler and scabbler. However, operating costs are outweighed by the lower purchase price of the grinder (50% of the price of the baseline scaler and 8% of the price of the baseline scabbler). Overall, the concrete grinder is an attractive alternative to traditional scabbling and scaling pneumatic tools. To this end, in July 1998, the outer rod room exposed walls of the Safe Storage Enclosure (SSE), an area measuring approximately 150 m{sup 2}, may be decontaminated with the hand-held grinder. This concrete grinder technology was demonstrated for the first time at the DOE`s Hanford Site. Decontamination of a sample room walls was performed at the C Reactor to free release the walls prior to demolition. The demonstration was conducted by onsite D and D workers, who were instructed by the vendor prior to and during the demonstration