Leaching from Cementitious Waste Forms in Belowground Vaults
Publication: Journal of Environmental Engineering
Volume 120, Issue 6
Abstract
Solidification and/or stabilization with cementitious materials prior to burial is one option for disposal of liquid hazardous and radioactive wastes. A common design for disposal of cementitious waste forms is to pour the material into large belowground vaults. The leaching performance of partially degraded monolithic vaults is examined quantitatively for facilities located in humid to semiarid climates. Development of perched water on the vault roof leading to fracture flow through the structure is predicted for a wide range of climate and design conditions. Leaching controlled by diffusion in matrix blocks out to fractures is examined parametrically in relation to water flux rate and crack spacing. Depending upon the parameters examined, release rate may be controlled by water flux rate (advection controlled) or diffusion. Under some circumstances, contaminant release rates and exit concentrations are predicted to be inversely related. In this situation, minimization of release does not result in the lowest predicted groundwater concentrations below the vault.
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Copyright © 1994 American Society of Civil Engineers.
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Received: Jan 4, 1993
Published online: Nov 1, 1994
Published in print: Nov 1994
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