OVERVIEW OF CURRENT REMEDIATION TECHNOLOGIES FOR URANIUM CONTAMINATED GROUNDWATER AQUIFERS

Uranium contamination in the subsurface is widespread at nuclear fuel cycle processing facilities where it occurs in a variety of biogeochemical environments. Current remediation technologies focus on in situ immobilization of uranium using a variety of biogeochemical processes including acid neutralization, chemical reduction and sequestration, aerobic and anaerobic bioimmobilization with various amendments, enhanced sorption, and others, tailored to reduce aqueous solubility and mobility of aqueous uranium. Technical challenges include the frequent occurrence of a wide range of organic and inorganic co-contaminants with different chemical characteristics (e.g., redox or sorption behavior) and the difficulty in creating and sustaining targeted biogeochemical conditions in large, heterogeneous aquifers. Nevertheless, simple models can adequately predict uranium behavior in the subsurface and can be useful for exploring various remediation alternatives using well known biogeochemical principles.