Long-term ecological behaviour of abandoned uranium mill tailings : 3. Radionuclide concentrations and other characteristics of tailings, surface waters, and vegetation / for Environment Canada

Abstract

Physical and chemical characteristics of abandoned, or inactive, uranium mill tailings are compared with those of the mineralized nontailings environments. Concentrations of radionuclides and heavy metals in uranium tailings, nontailings mineral areas, vegetation, and surface waters have been measured. The differences between wetlands and terrestrial areas of the uranium tailings are described. Concentrations of radionuclides and heavy metals in vegetation and surface waters from uranium mill tailings were generally lower. Uptake of radium-226 and lead-210 in cattail populations and trees (white birch and trembling aspen) appeared to be species-specific. Aerial deposition of tailings on the above-ground leafy matter of trees did not seem to affect their radionuclide concentration. In the wetlands on uranium tailings, radionuclide and heavy metal concentrations in cattail litter suggest that the litter acts as a sink for theses elements. The concentrations of the contaminants in surface waters on uranium tailings are not much different from those in waters on control nontailing areas.