Transport Properties of Radionuclides and Hazardous Chemical Species in Soils at the Idaho Chemical Processing Plant.

摘要

Near-surface, on-site disposal is being evaluated as a no-action alternative for future environmental documentation for high-level radioactive waste (HLW) stored at the Idaho Chemical Processing Plant (ICPP). As part of this evaluation, a three-dimensional code, TRACR3D, is being used to model potential transport of radioactive and hazardous species from the calcine to the Snake River Plain Aquifer under various water-contact scenarios. Laboratory studies have been completed to provide measured transport parameters for selected radionuclides and hazardous chemical species to allow for the development of accurate solute transport models. Distribution coefficients (Kd) for cadmium, mercury, selenium (as SeO(sub 3)(sup =)), and strontium were measured using batch equilibrium sorption methods. Measured distribution coefficients for the sorption of cadmium and strontium on sedimentary materials were very nearly independent of initial metal concentrations in contrast to mercury and selenium whose Kd values were highly dependent on initial metal concentrations. Distribution coefficient ranges in units of mL/g were as follows: alluvium, Cd 2864-4891, Hg 236-1912, Se 5.8-63, Sr 35-52; interbed sediment, Cd 8622-10,115, Hg 72-673, Se 4.9-17, Sr 110-186; basalt, Cd 785-2319, Hg 9.2-87, Se 0.29-3.4, Sr 1.1-2.7. 22 refs., 9 figs., 8 tabs.