Pilot-scale treatability testing -- Recycle, reuse, and disposal of materials from decontamination and decommissioning activities: Soda blasting demonstration

The US Department of Energy (DOE) is in the process of defining the nature and magnitude of decontamination and decommissioning (D and D) obligations at its sites. With disposal costs rising and available storage facilities decreasing, DOE is exploring and implementing new waste minimizing D and D techniques. Technology demonstrations are being conducted by LMES at a DOE gaseous diffusion processing plant, the K-25 Site, in Oak Ridge, Tennessee. The gaseous diffusion process employed at Oak Ridge separated uranium-235 from uranium ore for use in atomic weapons and commercial reactors. These activities contaminated concrete and other surfaces within the plant with uranium, technetium, and other constituents. The objective of current K-25 D and D research is to make available cost-effective and energy-efficient techniques to advance remediation and waste management methods at the K-25 Site and other DOE sites. To support this objective, O'Brien and Gere tested a decontamination system on K-25 Site concrete and steel surfaces contaminated with radioactive and hazardous waste. A scouring system has been developed that removes fixed hazardous and radioactive surface contamination and minimizes residual waste. This system utilizes an abrasive sodium bicarbonate medium that is projected at contaminated surfaces. It mechanically removes surface contamination while leaving the surface intact. Blasting residuals are captured and dissolved in water and treated using physical/chemical processes. Pilot-scale testing of this soda blasting system and bench and pilot-scale treatment of the generated residuals were conducted from December 1993 to September 1994