Intense volume reduction of mixed and low-level waste, solidification in sulphur polymer concrete, and excellent disposal at minimum cost

Progressive changes in regulations governing the disposal of the nation's radioactive and hazardous waste demand the development of more advanced treatment and disposal systems. The US Department of Energy's Radioactive Waste Technology Support Program was given the task of demonstrating the degree of excellence that could be achieved at reasonable cost using existing technology. The resulting concept is a Waste Treatment and Disposal Complex that will fully treat contact-handled mixed and low-level radioactive waste to a disposal product that is totally liquid-free and approximately 98% inorganic. An excellent volume reduction factor is achieved through sorting, sizing, incineration, vitrification, and final grouting. Inorganic waste items larger than 1/4 in. will be placed in inexpensive, uniform-sized, smooth-sides, thin-walled steel boxes. The smaller particles will be mixed with sulfur polymer concrete and pumped into the boxes, filling most voids. The appendage-free boxes measuring 1 x 1 x 1 m will be stacked tightly in an abovegrade, earth-mounded, concrete disposal vault where a temporary roof will protect them from rain and snow. A concrete roof poured directly on top of the dense, essentially voidless waste stack will be topped by an engineered, water-shedding earth cover. Total cost for design, construction, testing, 30 years of treatment and disposal, administration, decontamination and decommissioning, site closure, and postclosure monitoring and maintenance will cost less per cubic foot than is currently expended for subsurface disposal. A radiological performance assessment shows this concept will exceed the nation's existing disposal systems and governmental performance objectives for the protection of the general public by a factor of 30,000