The durability of a novel brick wastform for the immobilization of low-level mixed waste

A project has been initiated to determine if a process using a new shale for tile and brickmaking can be developed for the treatment and immobilization of low-level and/or hazardous waste. Two wastes generated by the U.S. Department of Energy nuclear weapons programs were used in order to determine the feasibility of this technology. These include a wastewater treatment sludge from the plutonium recovery operations at the Rocky Flats Plant (RFP) in Colorado and contaminated soil at the Fernald Site in Ohio. In this preliminary study, surrogates of these wastes were mixed with the shale material, formed, and then fired. The final open-quotes bricksclose quotes were then evaluated for chemical and physical durability. Results of the Toxicity Characteristic Leaching Procedure for ceramic wasteforms with 50% waste loading are given; leaching was below applicable limits for cadmium, chromium, nickel, and lead for both wastes. The process was simple in design, had a volume reduction of approximately 50% for the surrogate sludge, and has the potential to rival vitrification in terms of storage and disposal costs of the final wasteforms