Cameco halts Saskatchewan uranium mill after floods

Canadian uranium miner Cameco (TSX: CCO; NYSE: CCJ) has temporarily halted production activities at its Key Lake mill and reduced activity at its McArthur River mine after flooding damaged transport infrastructure in northern Saskatchewan.

Operating sites were not directly affected by flooding, but the collapse of the Smoothstone River Bridge disrupted the primary route used to move supplies to McArthur River and Key Lake, Cameco said Sunday. Restrictions on an alternative road have also limited Cameco’s ability to reroute deliveries.

Full operations won’t resume until normal deliveries of critical operating materials can restart, Cameco said. The timeline remains unknown.

“If the Key Lake mill is down for a full month, McArthur River would almost certainly be forced into a total production halt,” Uranium Equities analysts said. They estimated the direct production impact could be about 1.5 million lb. of uranium.

McArthur River’s slurry tanks and mobile truck containers can hold only about seven to 10 days of full production, the analysts said.

Cameco’s Cigar Lake mine continues to operate and its consolidated annual production plan remains unchanged. Prolonged road restrictions and continued disruption to deliveries of critical operating materials could affect the 2026 production outlook for the McArthur River/Key Lake operation, the company said.

Any production shortfall may force the company to buy or borrow uranium to meet commitments, potentially weighing on free cash flow, BMO analyst Alexander Pearce said in a note. 

Disruptions at McArthur River — one of the world’s largest uranium mines and a major contributor to global supply — could further tighten an already undersupplied uranium market and support spot uranium prices, Pearce added.