Leach Characterization of Phosphate-Sulfate Waste Grouts: Fid-Bau Portal

Leach Characterization of Phosphate-Sulfate Waste Grouts

T. V. Rebagay / D. A. Dodd

The Grout Treatment Facility (GTF) at the Hanford Site near Richland, Washington, is the first in the United States to process and dispose of large-scale, low-level, radioactive liquid wastes as solidified cement-based grout. (The GTF is operated by the Westinghouse Hanford Company (Westinghouse Hanford) for the US Department of Energy--Richland Operations Office (DOE-RL).) Grout slurries are emplaced in near-surface concrete vaults, which include double-liner/leachate collection systems in accordance with regulations of the State of Washington and the Resource Conservation and Recovery Act (RCRA). Proper characterization of the grout and a sound understanding of the mechanisms controlling radionuclide/pollutant release and potential migration to the surrounding biosphere is essential to ensure public health and safety. It is the ability to make predictions of the long-term durability of the grout that is central to public acceptance of grout as the final disposal form of low-level, radioactive liquid wastes. Leaching is an important process controlling radionuclide/pollutant release from the grout to the biosphere/geosphere. Leach testing of grout specimens, prepared from the actual wastes for disposal, will provide direct indication of the most likely species that may be released. This investigation serves as support for the safety evaluation of cement-based phosphate-sulfate waste (PSW) grouts. 4 refs., 7 figs., 11 tabs. (ERA citation 14:028075)