Small Mammal Soil Burrowing as a Radionuclide Transport Vector at a Radioactive Waste Disposal Area in Southeastern Idaho

Abstract

AbstractDuring 1978 and 1979, small mammals excavated a total mass of 12,450 kg soil to the 36‐ha surface of a solid radioactive waste disposal area in southeastern Idaho. Elevated concentrations of 238Pu, 239,240Pu, and 241Am were detected in excavated and surface soils in the waste disposal area. The inventory of 66 µCi (90Sr, 137Cs, 238Pu, 239,240Pu, and 241Am) transported to the surface of the waste disposal area by small mammal excavations was significantly (P ≤0.05) greater than the 20 µCi estimated to occur in excavated soils at a control area where no radioactive waste was disposed. Seventy‐seven percent of the radioactivity in soil excavated to the surface of the waste disposal area by small mammals was 238Pu, 239,240Pu and 241Am; 98% of the radioactivity in excavated soil in the control area was 90Sr and 137Cs. Small mammal burrowing is a mode of transuranic radionuclide transport to the surface of the waste disposal area; however, the total amount of plutonium in excavated soils was only 0.05% of the amount estimated to occur in waste disposal area surface soils in 1974.