This study was performed as part of a larger study that involved injecting dissolved hydrogen into a well at a post-leached in-situ recovery (ISR) uranium mining site to stimulate reduction and immobilization of residual dissolved uranium. Pump tests were performed before and after hydrogen injection to determine if there had been a significant decrease in the formation’s hydraulic conductivity as a result of induced precipitation reactions. In addition, a bromide tracer study was performed to estimate the effective dispersivity of the formation. A MODFLOW hydraulic model was developed and calibrated to estimate the hydraulic conductivity, and an MT3D transport model was developed and calibrated to estimate the dispersivity. The best-fit hydraulic conductivity values before and after the hydrogen injection period were determined to be 0.0144 and 0.0059 ft/min, indicating that the formation permeability had decreased by 59% after the hydrogen injection. However, the hydraulic conductivity values before and after the hydrogen injection were in the range cited for clean sand. The best-fit longitudinal dispersivity value was determined at10 ft. This value was used to estimate that the effective zone of influence for the bromide injection – accounting for hydrodynamic dispersion – had a radius of 25 ft. This was 5.69 times greater than when considering advection alone.
January 30, 2015
The right to download or print any of the pages of this thesis (Material) is granted by the copyright owner only for personal or classroom use. The author retains all proprietary rights, including copyright ownership. Any reproduction or editing or other use of this Material by any means requires the express written permission of the copyright owner. Except as provided above, or any use beyond what is allowed by fair use (Title 17 Section 107 U.S.C.), you may not reproduce, republish, post, transmit or distribute any Material from this web site in any physical or digital form without the permission of the copyright owner of the Material. Inquiries regarding any further use of these materials should be addressed to Administration, Jernigan Library, Texas A&M University-Kingsville, 700 University Blvd. Kingsville, Texas 78363-8202, (361)593-3416.