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Corrective measures technology for humid sites

Description: The corrective measures technology task for humid sites consists of three subtasks. The first subtask has the objective of demonstrating that grout injection into closed burial trenches can achieve the hydrologic isolation of buried wastes. From laboratory testing of seven grout formulations, two promising grouts, 7.6% sodium silicate and 11.7% acrylamide, were selected for field demonstration by injection into 1:10-scale burial trenches. Both grouts effected a several orders of magnitude reduction in the mean hydraulic conductivity of the trench. The trench chemical treatment subtask has the objective of demonstrating the caustic soda injection into a closed trench's backfill and surrounding soil can achieve a fixation of radiostrontium from further ground water contamination. Monitoring of ground waters in and around the treated trench indicate a continued fixation of radiostrontium from further leaching. Soil samples were taken from the trench and found to contain /sup 90/Sr coprecipitated with calcium carbonate. The final subtask has the objective of demonstrating that the detection and treatment of ground water seeps can achieve a significant reduction in radiostrontium contamination of surface water. The utility of measuring /sup 90/Sr in ground water samples by Cerenkov radiation detection was found to be analytically equivalent to but considerably less expensive and time consuming than the standard radiochemical method.
Date: January 1, 1983
Creator: Spalding, B.P.
Partner: UNT Libraries Government Documents Department

Shallow Land Burial Technology - Humid

Description: The Shallow Land Burial Technology - Humid Project is being conducted for the Department of Energy Low-Level Waste Management Program with the objective of identifying and demonstrating improved technology for disposing of low-level solid waste in humid environments. Two improved disposal techniques are currently being evaluated using nine demonstration trenches at the Engineered Test Facility (ETF). The first is use of a cement-bentonite grout applied as a waste backfill material prior to trench closure and covering. The second is complete hydrologic isolation of waste by emplacement in a trench that is lined on all four sides, top and bottom using synthetic impermeable lining material. An economic analysis of the trench grouting and lining demonstration favored the trench lining operation ($1055/demonstration trench) over trench grouting ($1585/demonstration trench), with the cost differential becoming even greater (as much as a factor of 6 in favor of lining for typical ORNL trenches) as trench dimensions increase and trench volumes exceed those of the demonstration trenches. In addition to the evaluation of trench grouting and lining, major effort has centered on characterization of the ETF site. Though only a part of the overall study, characterization is an extremely important component of the site selection process; it is during these activities that potential problems, which may obviate the site from further consideration, are found. Characterization of the ETF has included studies of regional and site-specific geology, the physical and chemical properties of the soils in which the demonstration trenches are located, and hydrology of the small watershed of which the ETF is a part. 12 references, 6 figures, 2 tables.
Date: January 1, 1983
Creator: Davis, E.C.; Spalding, B.P. & Lee, S.Y.
Partner: UNT Libraries Government Documents Department

Characterization of hydrofracture grouts for radionuclide migration

Description: Detailed characterization of hydrofracture grouts was performed by optical microscopy, scanning electron microscopy, x-ray diffraction, and ..beta..-..gamma.. autoradiography. Laboratory-produced samples containing simulated wastes as well as actual radioactive samples of hydrofracture grout sheets obtained by core drilling were examined in this work. X-ray diffraction results revealed that both laboratory-produced samples and a core-drilled sample consisted primarily of calcium carbonate phases. Both sample types contained very small amounts of strontium or cesium wastes, neither of which could be detected by microscopic techniques. The core-drilled sample contained radioactive /sup 90/Sr, /sup 137/Cs, and /sup 60/Co that could be detected by ..beta..-..gamma.. autoradiography. The autoradiograph revealed that these radionuclides were still present in the 20-year-old grout and that they had not migrated into the trapped shale fragments.
Date: January 1, 1983
Creator: Stinton, D.P.; McDaniel, E.W. & Weeren, H.O.
Partner: UNT Libraries Government Documents Department

ORNL grouting technologies for immobilizing hazardous wastes

Description: The Cement and Concrete Applications Group at the Oak Ridge National Laboratory (ORNL) has developed versatile and inexpensive processes to solidify large quantities of hazardous liquids, sludges, and solids. By using standard off the shelf processing equipment, these batch or continuous processes are compatible with a wide range of disposal methods, such as above-ground storage, shallow-land burial, deep geological disposal, sea-bed dumping, and bulk in-situ solidification. Because of their economic advantages, these latter bulk in-situ disposal scenarios have received the most development. ORNL's experience has shown that tailored cement-based formulas can be developed which tolerate wide fluctuations in waste feed compositions and still maintain mixing properties that are compatible with standard equipment. In addition to cements, these grouts contain pozzolans, clays and other additives to control the flow properties, set-times, phase separations and impacts of waste stream fluctuation. The cements, fly ashes and other grout components are readily available in bulk quantities and the solids-blends typically cost less than $0.05 to 0.15 per waste gallon. Depending on the disposal scenario, total disposal costs (material, capital, and operating) can be as low as $0.10 to 0.50 per gallon.
Date: January 1, 1983
Creator: Dole, L.R. & Trauger, D.B.
Partner: UNT Libraries Government Documents Department

Partitioning of cesium in hydrofracture grouts

Description: Phase characterization of hydrofracture grouts was accomplished with the use of optical microscopy, scanning electron microscopy, x-ray diffraction, and ..beta..-..gamma.. autoradiography. A laboratory-produced sample containing 1 wt % stable cesium and an actual hydrofracture grout sheet obtained by core dirlling were examined during this work. The phases present in these samples were identified and cesium was found to be absorbed almost entirely by illite clay agglomerates. These clay agglomerates were tightly bound within the grout structure by hydrated calcium silicates. The ..beta..-..gamma.. autoradiography of the core-drilled sample verified that cesium and other radionuclides were trapped within the 20-year-old grout and had not migrated into trapped shale fragments. 14 references, 3 figures, 1 table.
Date: August 31, 1983
Creator: Stinton, D.P.; McDaniel, E.W. & Weeren, H.O.
Partner: UNT Libraries Government Documents Department