Waste

Management of waste rock – Mining requires the excavation of other material (i.e. waste rock) to access the uranium bearing ore. This waste rock is classified based on the uranium content as either mineralized or non-mineralized, with the latter being further classified as potentially acid generating or non-acid generating. All of the waste rock at our sites has to be managed to control leaching of metals and to protect the environment.

Tailings management and storage – At our mill sites in northern Saskatchewan, we produce tailings that are comprised of the residual rock left after the uranium is recovered from the ore. Uranium recovery rates from the ore are very high, however, and a small percentage of the uranium and other radionuclides remain in the tailings. The tailings also include gypsum generated from the use of sulfuric acid and lime in the milling process. Tailings are an inevitable byproduct of milling ore and the volume of tailings we produce is dependent on the ore grade and the production rate.

Safe handling and storage of low-level radioactive and other hazardous waste – The biggest challenge related to managing radioactive and other hazardous wastes is storing and handling them safely, including making sure we prevent spills or other accidental releases that could harm people or the environment.

Waste rock reuse – the amount of waste rock we can reuse depends on the type of rock available and the number of projects we have in progress. We use uneconomical mineralized waste rock as blend material for processing ore and for backfilling in our mines. We also blend clean waste rock into concrete mixtures that we use to build new facilities and maintain roads. This reduces the size of our waste rock piles and the amount of other natural aggregate resources we consume.

Waste rock storage and decommissioning – while most of Cameco’s waste rock is not acid generating, we store any potentially acid generating material on lined pads that provide a barrier between the waste rock and the ground and employ systems to divert or collect runoff water for treatment. We monitor groundwater near the piles regularly to make sure the pads are working as designed.

Clean waste rock piles typically are re-used for other purposes or decommissioned on surface. Piles that are decommissioned on surface are re-graded and re-vegetated to blend them into the surrounding environment. If necessary the piles are covered to reduce infiltration and protect the surrounding surface water.

Recently, we’ve started using store and release covers on our waste rock piles as a protective measure. These engineered soil and plant coverings store water during wet periods and release it back into the atmosphere during dry periods, reducing the amount of precipitation that filters through to the rock pile. We’ve had considerable success with this type of cover at our decommissioned zone B waste rock pile at Rabbit Lake and we plan to use it with other waste rock piles in the future.

Tailings management – we treat our mill tailings to stabilize contaminants before depositing them in our tailings facilities. Surface and groundwater is diverted around tailings and water that comes into contact with tailings is collected and treated to remove contaminants.

We have a strong understanding of the content of our mill tailings and how to manage them. Based on nearly 20 years of research in partnership with the University of Saskatchewan, we’re confident we’re managing our tailings responsibly.

Tailings management facilities – Cameco pioneered in-pit tailings management facilities. These engineered storage facilities are designed to protect the environment for thousands of years. They’re recognized as a best practice in tailings management around the world.

More about our tailing management facilities

Radioactive waste management – we adhere to the terms of our licences, internal policies and procedures, and the CNSC’s radioactive waste policy framework to manage our low-level radioactive waste responsibly.

At our mining and milling operations in northern Saskatchewan, we take a zone control approach. Anything used within a specified area is assumed to have been in contact with ionizing radiation and is treated as radiologically contaminated.

Our fuel services division in Ontario is actively working to reduce the amount of low-level radioactive waste they’re currently storing and to minimize the amount of new waste they generate. To support this effort, all potentially contaminated materials are scanned to determine whether they need to be treated as radioactive waste. Clean waste is reused, recycled or directed to conventional landfill facilities.

More about the radioactive waste policy framework

Byproduct waste recovery – ammonium nitrate and ammonium sulphate are useful byproducts of our milling and conversion operations. We sell these materials to third parties as fertilizer.

The CNSC has granted approval to recover uranium-bearing byproducts from our Ontario refining and conversion operations at Key Lake in northern Saskatchewan. We are undertaking tests at the mill in order to ensure that processing the byproduct doesn’t negatively impact our effluent.

Waste reduction efforts – our operations are always looking for ways to reduce and divert hazardous and non-hazardous waste, including application of incineration/gasification technologies. In 2013, Port Hope was very successful in reducing radiologically contaminated material as the conversion facility recycled as much waste (by volume) as they generated in all of 2013. As well, Blind River has been successfully grit-blasting used yellowcake drums since 2011 to decontaminate them so that the scrap metal can be sold and recycled.