APPLICATIONS OF GEOCHEMICAL MODELING TO REMEDIATION OF URANIUM CONTAMINATION AND URANIUM ORE DEPOSIT FORMATION

In this presentation, I will first give a brief review of the current status of geochemical modeling and then give a few examples of applications and potential applications. Geochemical modeling is a useful and sometimes indispensable tool because (1) we need predictions for various scenarios and future performances; (2) quantitative test of our conceptual models; and (3) help in understanding the complex feedback loops of various processes and reactions. For some uranium mill tailings sites, uranium fate and transport is a result of coupled groundwater flow and a complex network of geochemical reactions. An example will be shown for using a coupled multi-component reactive mass transport model to predict the natural attenuation of a ground water plume at a uranium mill tailings site in western USA. A second example will show bioremediation of uranium contaminated soil and groundwater site. We will show that the progress on the computer code developments and our understanding of biogeochemical reactions, but the lack of thermodynamic, kinetics, and microbiological parameters makes it difficult to define unique models. Finally, potential applications of geochemical modeling to the studies of uranium ore deposits will be discussed.