McArthur River/Key Lake

  • McArthur River/Key Lake, located in northern Saskatchewan, Canada, are the world's largest high-grade uranium mine and mill.
  • 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, 2023)
McArthur River Reserves(As of December 31, 2023)

2023 Q4 Update


McArthur River Production

Cameco's Share (million lbs)

Three months ended
December 31
Year ended
December 31
2023 2022 2023 2022 2023 Plan1

2024 Plan

3.1 0.8 9.4 0.8 up to 9.8


1. During the third quarter, we updated our McArthur River/Key Lake production forecast to 14 million pounds (100% basis) in 2023 (previously 15 million pounds).

The McArthur River and Key Lake operation was in a state of safe care and maintenance from 2018 through 2021 due to weak market conditions. The operation began transitioning back to production through the first three quarters of 2022, with no packaged pounds until the fourth quarter of 2022. Production ramp-up activities continued in 2023.

Total packaged production from McArthur River and Key Lake in 2023 was 13.5 million pounds (9.4 million pounds our share), slightly less than the announced September 3, 2023, forecast of 14 million pounds (9.8 million pounds our share).

The McArthur River mine continued to operate well and achieved its planned mine production for the year. Any ore from McArthur River that was not immediately processed at Key Lake is stored in inventory for future milling. All required mine activities have now resumed at McArthur and the site is now considered to be back in normal mine operations.

At the Key Lake mill, the extended period of time the mill was on care and maintenance, the operational changes made, aging infrastructure, the availability of personnel with the necessary skills and experience, and the impact of supply chain challenges on the availability of materials and reagents combined to impact production in 2023.


In October 2023, the Canadian Nuclear Safety Commission (CNSC) granted 20-year renewals to the licences for both McArthur River and Key Lake. The renewed licences are expected to allow McArthur River and Key Lake to operate until October 2043.


Underground exploration at McArthur River resumed in June 2023 with the resumption of infill drilling of zone B. Infill drilling of zone B will continue in 2024.

Planning for the future


We plan to produce 18 million pounds (100% basis) in 2024. Over the last three months, the mill has been running at a rate that, when annualized, would allow this operation to achieve its 2024 planned production. In 2024, we plan to undertake an evaluation of the work and investment necessary to expand production up to its annual licensed capacity, which we expect will allow us to take advantage of this opportunity when the time is right. We will continue to plan our production to align with our contract portfolio and market opportunities, demonstrating that we continue to be a responsible supplier of uranium fuel.

Managing our risks

The McArthur River deposit presents unique challenges that are not typical of traditional hard or soft rock mines. These challenges are the result of mining in or near high pressure ground water in challenging ground conditions with significant radiation concerns due to the high-grade uranium. We take significant steps and precautions to reduce the risks. Mine designs and mining methods are selected based on their ability to mitigate hydrological, radiological and geotechnical risks. Operational experience gained since the start of production has resulted in a significant reduction in risk. However, there is no guarantee that our efforts to mitigate risk will be successful.

We discuss managing our risks in our Q4 2023 MD&A.

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.