McArthur River/Key Lake

  • McArthur River/Key Lake, located in northern Saskatchewan, Canada is the world's largest high-grade uranium operation.
  • In July, 2018, due to prolonged market weakness, the operation was placed into safe and sustainable care and maintenance.
  • In service since 1999 and 1983 respectively, Cameco operates the ISO 14001 certified locations, which have collectively produced 535 million lbs using a variety of mining methods.
Operation(As of December 31, 2020)
McArthur River Reserves(As of December 31, 2020)

2020 Q4 Update

Production Suspension

The facilities remained in a state of safe and sustainable care and maintenance throughout 2020.

Approximately 185 Cameco employees remain employed at the McArthur River and Key Lake sites. Care and maintenance activities include mine dewatering, water treatment, freeze wall maintenance, and environmental monitoring. In addition, preservation maintenance and monitoring of the critical facilities continues.

Our objective is that the McArthur River and Key Lake operations are available to return to production in a timely manner once a decision is made to end the production suspension.


As a result of the production suspension, there was no exploration activity in 2020.

Planning for the future


Due to continued uranium price weakness, we have suspended production for an indeterminate duration. A restart of the mine and mill is a commercial decision that will be based on our ability to commit our share of production from this operation under acceptable long-term contracts and to benefit from the favourable life-of-mine economics it provides.

As a result of the suspension, and the time required to restart the mine and mill, we do not expect the operation to produce any uranium in 2021. Our share of the cash and non-cash costs to maintain both operations during the suspension is expected to range between $8 million and $10 million per month.


In 2020, we began a program to advance the assessment of innovation opportunities at the McArthur River mine and Key Lake mill.

We established a team of internal experts who have been tasked with assessing, designing and implementing opportunities to improve operating efficiency. During the year, the team advanced a portfolio of 43 projects focused on improvement of the mine and mill through application of automation, digitization and optimization.

The initial assessment of the majority of the projects was completed, which will allow us to complete the pre-feasibility work and to define the business case. We expect projects that meet our investment criteria will be advanced to implementation in 2021.

Optimizing production

The technical report dated March of 2019 is based on a production rate of 18 million pounds per year, however, once a restart decision is made, we plan to optimize the production rate to respond to market signals. We expect that this paced approach will allow us to extract maximum value from the operation as the market transitions.

See full Quarterly Report

Environment & Safety

Worker safety, environmental monitoring and proper decommissioning, after mining is completed, are of the utmost importance to Cameco.

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Reserves & Resources

Our mineral reserves and resources are the foundation of our company and fundamental to our success.

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Caution about forward-looking information

This page may contain forward-looking information that is based upon the assumptions and subject to the material risks discussed on page 2 of Cameco's most recent Quarterly MD&A.