Performance of an Engineered Cover System for a Uranium Mine Waste Rock Pile in Northern Saskatchewan After Six Years

The Claude waste rock pile at Cluff Lake uranium mine in northern Saskatchewan's Athabasca basin contains ~7.2 million tonnes of waste rock, upon which an engineered enhanced store-and-release cover system was constructed. The primary design objectives of the cover system are to reduce percolation of meteoric waters into the waste rock pile, attenuate radiation emanating from stored waste to acceptable levels, and provide a growth medium for development of a sustainable vegetation cover. Instrumentation was installed during construction of the cover system to evaluate cover performance under site-specific climate conditions. Field data collected was input to water  balances to quantify the volume of net percolation that occurred during the frost-free periods of 2007 to 2012. Based upon these water balances, the Claude waste rock pile cover system is performing as designed based on field monitoring data and observations collected since 2007.