Saltstone Disposal Facility (SDF) for Waste Incidental to ReprocessingAiken, South Carolina
Operator: U.S. Department of Energy
General Description of Saltstone Disposal Facility for Waste Incidental to Reprocessing
The 780 square kilometer (300 square mile) DOE SRS, located in south-central South Carolina, began operation in 1951 producing nuclear material for national defense, research, medical, and space programs. Waste produced at the site from spent nuclear fuel reprocessing for defense purposes has been commingled with non-reprocessing waste resulting from the production of targets for nuclear weapons and production of material for space missions. Significant quantities of radioactive waste are currently stored on-site in large underground waste storage tanks, which were placed into operation between 1954 and 1986. The waste stored in the tanks at SRS is a mixture of insoluble metal hydroxide solids, referred to as sludge, and soluble salt supernate. The supernate volume has been reduced by evaporation, which also concentrates the soluble salts to their solubility limits. The resultant solution crystallizes as salts, and the resulting solid is referred to as saltcake. The saltcake and supernate combined are referred to as salt waste. DOE removes the salt waste, treats it to remove highly radioactive radionuclides to the maximum extent practical, and disposes the low activity fraction on site in the SDF. The SDF is located in the Z-area of the SRS approximately 10 km (6.2 mi) from the nearest SRS site boundary on a well-drained local topographic high.
The Saltstone Facility consists of two facility segments, the SPF, which receives and treats salt solution to produce solidified saltstone, and the SDF, which consists of existing vaults and projected FDCs used for the final disposal of the solidified saltstone. The SPF is permitted by the State of South Carolina as a wastewater treatment facility. The SDF is permitted by the State of South Carolina as a Class 3 Landfill.