Dams and Frozen Core Dams
Frozen core dam technology has proven to be a successful, cost-effective method of earth dam construction that utilizes the most abundant natural resource in the Arctic: cold weather. Structurally and environmentally sound, frozen core dams provide the most efficient and reliable control of tailings and other materials in a region where cohesive materials such as clay are not available.
Nuna constructed the CEA award–winning 800-metre Leslie Long Lake frozen core dam (Ekati Diamond Mine) for the containment of 100 million cubic metres of processed kimberlite. We increased construction productivity by designing and assembling our own frozen core plant from a modified asphalt plant.
The frozen core plant produces thawed, saturated sand and gravel used for the dam core. Thermosyphons are installed throughout the core into the underlying talik (unfrozen zone), and thermistors are installed to monitor the dam and foundation temperatures. The plant is designed to accurately monitor the moisture content and temperature of core granular material prior to placement. It can produce up to 3,000 tonnes per 24-hour shift.