Wednesday, April 14, 2010: 2:10 p.m.
Continental A (Westin Tabor Center, Denver)
Uranium One plans to conduct in situ recovery (ISR) of uranium at the Moore Ranch Project in the Powder River Basin of Wyoming. The target ore zone is within the water table aquifer across portions of the site. Because ISR mining is commonly conducted in aquifers dominated by confined flow, a detailed hydrologic test was conducted to evaluate hydraulics associated with unconfined flow during projected ISR operations and to further characterize aquifer properties within the production zone aquifer. The hydrologic test was performed on a five-spot well pattern installed in an area of a proposed mine unit where unconfined aquifer conditions are prevalent.
The five-spot well pattern test (which included a centrally located recovery well, four injection wells and several monitor wells) was conducted in two phases. The initial phase included only extraction from the recovery well. The second phase of the test included reinjection of water extracted from the recovery well. Data from the tests allowed detailed characterization of production zone aquifer properties. Results of the extraction/injection test indicate that the production zone aquifer can sustain recovery and injection rates that are anticipated during ISR mining.
Data derived from the five-spot hydrologic test were used to develop a numerical model that is representative of site-specific conditions (including the unconfined nature of the production zone aquifer) on a well-pattern scale. The numerical model was calibrated to measured field data from the test. The calibrated model was used to evaluate impacts of an unconfined system on ISR wellfield design and operations. The results of the initial well-pattern scale model were extrapolated to a wellfield and permit area scale model to evaluate wellfield bleed, operational flare, excursion control, water disposal requirements and restoration operations. Testing and modeling confirmed that fluid movement could be controlled during proposed mining operations using reasonable operating practices.
The five-spot well pattern test (which included a centrally located recovery well, four injection wells and several monitor wells) was conducted in two phases. The initial phase included only extraction from the recovery well. The second phase of the test included reinjection of water extracted from the recovery well. Data from the tests allowed detailed characterization of production zone aquifer properties. Results of the extraction/injection test indicate that the production zone aquifer can sustain recovery and injection rates that are anticipated during ISR mining.
Data derived from the five-spot hydrologic test were used to develop a numerical model that is representative of site-specific conditions (including the unconfined nature of the production zone aquifer) on a well-pattern scale. The numerical model was calibrated to measured field data from the test. The calibrated model was used to evaluate impacts of an unconfined system on ISR wellfield design and operations. The results of the initial well-pattern scale model were extrapolated to a wellfield and permit area scale model to evaluate wellfield bleed, operational flare, excursion control, water disposal requirements and restoration operations. Testing and modeling confirmed that fluid movement could be controlled during proposed mining operations using reasonable operating practices.