McArthur/Key Lake

  • The title of world's largest uranium producer belongs to the the McArthur River-Key Lake tandem operation located in northern Saskatchewan, Canada.
  • Cameco operates both ISO 14001 certified locations which have been in production since 1999 and 1983 respectively.
  • Combined, these two operations have reliably produced more than 518 million lbs using a variety of mining methods best-suited for the ground conditions.

McArthur River Video

Key Lake Video

Operation(As of December 31, 2016)
Cameco ownership, McArthur River (70%), Key Lake (83%)
1,299 people employed, 54% are from northern Saskatchewan
Production(As of December 31, 2016)
Average grade of 9.6% U3O8
Licenced to 2023
12.6 m lbs U3O8 annual production trend (Cameco's share)

2016 Update


Production from McArthur River/Key Lake was 18.0 million pounds; our share was 12.6 million pounds. This was 6% lower than 2015 and 10% lower than our initial forecast for the year due to our decision to reduce production amid weak market conditions.

McArthur River/Key Lake Production

Cameco's Share (millions lbs)

3 months ended
December 31
Year ended
December 31
2016 2015 2016 2015 2016 Plan 2017 Plan
3.8 3.8 12.6 13.3 12.6 12.6

Key Lake mill upgrades

The Key Lake mill began operating in 1983 and we have continually upgraded circuits with new technology to simplify operations, improve environmental performance, and allow the mill’s nominal annual production rate to closely follow production from the McArthur River mine. As part of the mill upgrades, a new calciner was installed at the Key Lake mill to accommodate an eventual annual production increase to 25 million pounds. However, reliability issues were encountered with the new equipment during commissioning. Since market conditions do not currently support a decision to increase production, and as part of our continuing efforts to reduce costs, in 2016, we suspended the commissioning of and transition to the new calciner. We are assessing the cost to resolve the issues and expect to complete commissioning if we determine that there is financial and operational value in adding new calcining capacity. The existing calciner has sufficient capacity to meet our 2017 production target of 18 million pounds (12.6 million pounds our share).

New mining areas

We must bring on new mining zones to sustain production, and two new areas are currently under active development: the upper central portion of zone 4, and zone 1. In order to support the development of these zones, infrastructure expansions are required related to freeze capacity and ventilation. In 2016, we completed the upgrade of our surface electrical infrastructure as part of our plan to address current and future needs. We also continued construction of the next freeze plant, which is scheduled to begin freezing the south end of the orebody (zone 4) in 2017.

The mine life of McArthur River/Key Lake has been extended from 2033 to 2037 as a result of changes to the annual production assumptions in our mine plan, and the work completed to upgrade resources to reserves in zone A.


In 2016, we began underground infill definition drilling of zone B in order to provide the information required for more detailed mining plans.

See full Quarterly Report

Environment & Safety

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

See more

Reserves & Resources

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

See more

Caution about Forward-Looking Information

Please click here for additional information about the assumptions applied in making the forward-looking statements on this page and the factors that could cause results to differ materially.