McArthur River/Key Lake

McArthur River Production
Cameco's Share (million lbs)

1. During the third quarter, we updated our McArthur River/Key Lake production forecast to 19 million pounds (100% basis) in 2024 (previously 18 million pounds.)

The McArthur River and Key Lake operation continued with production rampup and optimization activities in 2024.
Total packaged production from McArthur River and Key Lake in 2024 was 20.3 million pounds (14.2 million pounds our share), compared to 13.5 million pounds (9.4 million pounds our share) in 2023. Production in 2024 exceeded our annual expectation of 19 million pounds (13.3 million pounds our share).

The McArthur River mine produced 15.8 million pounds, which was less than its plan to mine 18.3 million pounds, primarily due to an unplanned shutdown at the mine to accommodate ventilation repairs in Shaft 2. In addition, the mine’s performance was impacted by the availability of mobile equipment and certain workforce skills.

The Key Lake mill saw notable improvements in its operational performance in 2024, with the site becoming more familiar and experienced with new equipment and control system upgrades. In addition, the systematic understanding of process bottlenecks and efforts to remove or decrease their impacts allowed Key Lake to optimize the mill throughput rates.

Of note, our 2024 packaged production of 20.3 million pounds of U3O8 sets both a new annual production record for the Key Lake mill, as well as a new world record for annual production from any uranium mill. These significant achievements were made possible in part by our off-cycle investments during care and maintenance to improve and optimize the Key Lake mill, and by having sufficient ore feed material available, which included the ore mined at McArthur River in 2024 (which was lower than its plan), supplemented by broken ore inventory at McArthur River and Key Lake that was carried over from prior years.

Underground exploration at McArthur River continued in 2024 with the main focus areas being infill drilling of zones A and B.

We plan to produce 18 million pounds (100% basis) in 2025. Although the performance of the Key Lake mill in 2024 demonstrated production rates and capacities that, when annualized, exceeded 18 million pounds, the operation’s output is currently constrained by the McArthur River mine’s limited ability to increase the production of mined ore to feed the mill, and because the majority of the previously mined, excess broken ore inventory that allowed the mill to exceed production expectations in 2024, has been processed. In 2025, we expect to bring zone 1 into production and advance zone 4 south development while we continue adding to our workforce and replacing mobile equipment. We also plan to expand both underground and surface exploration activities in 2025.

We are addressing aging infrastructure and potential bottlenecks at Key Lake and the advancement of freezing at McArthur River to ensure reliability and sustainability. While these projects are required to support and maintain capacity at current production levels, they have been classified as growth because they also position us for future production flexibility, including to its licensed annual capacity of 25 million pounds, although no decision on changes to future production levels has been made. We will plan our production in line with market opportunities and our contract portfolio, demonstrating that we continue to be a responsible, long-term supplier of uranium fuel.