Distribution of plutonium among soil phases near a Subsurface Disposal Area in Southeastern Idaho, USA

Abstract

The physicochemical association of plutonium in soil near the Subsurface Disposal Area (SDA) at the Idaho National Engineering and Environmental Laboratory (INEEL) has been determined using selective sequential extraction techniques. Our results suggest that plutonium in surface soils is associated primarily with the hydrous oxide coatings of the soil (37±5.3%). Appreciable amounts of plutonium were also removed with the organic matter (22±2.8%) and carbonates (13±3.1%). On the other hand it appears that plutonium association with the soluble and exchangeable components of the soil is relatively small (>4.0%). The remainder of plutonium (21±4.7%) is tightly bound to the refractory silicate residue of the soil. Relatively little plutonium is available for physicochemical mobilization from the soil under the present prevailing conditions of the INEEL site.