Characterization of Radionuclide Resuspension via Aeolian Processes at a Uranium Mill Tailings Site.

Abstract: A former uranium recovery facility located in northwestern New Mexico currently serves as a uranium mill tailings site undergoing reclamation and decommissioning. High velocity winds are common in the area, causing soil erosion via aeolian processes. Strong winds may carry soil for several kilometers, which is redeposited downwind. This study estimates the potential for impact on remediation efforts caused by downwind contamination from soil-bound 226 Ra resuspension. The study was performed by measuring the mass of soil moving onsite to determine horizontal saltating flux over the period of 3 mo. Previous frameworks relating dimensional flux were used to estimate suspension flux from site-massed saltating flux. Using concentrations of soil-bound radionuclides and meteorological data collected onsite, a modified Gaussian plume model estimating downwind deposition of contaminants was constructed. The highest deposition rate calculated, 6.81 × 10 -15 Bq cm -2 s -1 , suggests approximately 4.3 million years of deposition are required to exceed the criterion for release, a far longer timespan than the expected remediation and release of the site in 2030. Based on the results, estimated impacts of windblown soil contamination were determined to be negligible.