Saskatchewan Canada Northern Saskatchewan Operations Update

Saskatoon

Saskatchewan

Canada

Northern Saskatchewan Operations Update

May 10, 2026

Cameco (TSX: CCO; NYSE: CCJ) today provided an operational update for our northern Saskatchewan sites

amidst flooding in the region, which is impacting roadways.

Our northern Saskatchewan sites are not directly impacted by flood waters. However, flooding has caused the

collapse of the Smoothstone River Bridge, which is on the primary route we use to transport supplies to the

McArthur River and Key Lake sites, and there are restrictions in place on the use of an alternative roadway. We are

in regular contact with the Saskatchewan Ministry of Highways, and we are working with our sites to minimize the

impact of delivery disruptions. However, we have temporarily halted production activities at Key Lake mill and

reduced activity at McArthur River mine until the normal delivery of critical operating materials can resume. The

timeline for the resumption of normal deliveries is currently unknown.

At present, the Cigar Lake mine continues to operate, and our consolidated annual production plan remains

unchanged. Depending on the duration of the road restrictions and our ability to make deliveries of critical

operating materials, there is a risk that our 2026 production outlook for the McArthur River/Key Lake operation

could be impacted.

Profile

Cameco is one of the largest global providers of the uranium fuel needed to power a secure energy future. Our competitive position is based

on our controlling ownership of the world’s largest high-grade reserves and low-cost operations, as well as significant investments across

the nuclear fuel cycle, including ownership interests in Westinghouse Electric Company and Global Laser Enrichment. Utilities around the

world rely on Cameco to provide global nuclear fuel solutions for the generation of safe, reliable, carbon-free nuclear power. Our shares

trade on the Toronto and New York stock exchanges. Our head office is in Saskatoon, Saskatchewan, Canada.

As used in this news release, the terms we, us, our, the Company and Cameco mean Cameco Corporation and its subsidiaries unless

otherwise indicated.

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Investor inquiries Media inquiries

Cory Kos Veronica Baker

306-716-6782 306-385-5541

[email protected] [email protected]

www.cameco.com

NEWS RELEASE

All amounts in Canadian dollars

unless specified otherwise