STOCK TITAN
  1. Home
  2. Sec-filings
  3. CCJ
  4. [6-K] CAMECO CORP Current Report (Foreign Issuer)

Cameco (NYSE: CCJ) pauses Cigar Lake mine as McClean Lake mill shuts acid plant

Filing Impact
(Neutral)
Filing Sentiment
(Neutral)
Form Type
6-K

Rhea-AI Filing Summary

Cameco Corporation has temporarily suspended mining at its Cigar Lake uranium mine in northern Saskatchewan because of operational challenges at Orano’s McClean Lake mill, where Cigar Lake ore is processed. The mill’s sulfuric acid plant has shut down for repairs, and Orano is working both on repairs and on alternative acid supply.

Cameco currently expects the McClean Lake mill to resume operations in approximately two weeks and does not expect this disruption to affect its 2026 production outlook for Cigar Lake. However, the company warns that longer-than-expected repairs or difficulties sourcing sulfuric acid could delay the restart and potentially impact the 2026 production outlook.

Positive

  • None.

Negative

  • None.

Insights

Short Cigar Lake shutdown adds operational risk but outlook unchanged for now.

Cameco reports a temporary halt of mining at Cigar Lake after Orano’s McClean Lake mill sulfuric acid plant was shut for repairs. Ore from Cigar Lake is processed exclusively at this mill, so milling cannot continue until sufficient acid supply is restored.

The company indicates McClean Lake is expected to restart in about two weeks and currently maintains its 2026 Cigar Lake production outlook. However, it highlights risks that repairs may take longer or that alternative sulfuric acid supplies may be harder to secure than assumed.

The event introduces near-term operational uncertainty tied to a third-party facility, while long-term production guidance remains intact in management’s view. Investors will likely look to future MD&A and information form updates for any quantified impact on the 2026 Cigar Lake production outlook if delays extend.

Expected disruption duration approximately two weeks Expected return to operation for McClean Lake mill
Production outlook period 2026 Cigar Lake production outlook referenced as unchanged but at risk
Cigar Lake mine financial
"Cameco ... announced our Cigar Lake mine in northern Saskatchewan has temporarily suspended operations"
McClean Lake mill financial
"challenges at Orano’s McClean Lake mill, where Cigar Lake ore is processed"
sulfuric acid plant technical
"McClean Lake mill has encountered operational challenges with its sulfuric acid plant that caused it to shut down"
A sulfuric acid plant is an industrial facility that converts raw materials such as sulfur or sulfide ores into sulfuric acid, a basic chemical ingredient used across fertilizers, mining, metal refining, and many manufacturing processes. Investors care because the plant’s output supports steady-demand industries, but it also requires large upfront investment, steady energy and raw material supplies, and faces strict environmental and safety regulations that can affect costs, permits and long-term profitability.
forward-looking information regulatory
"This news release includes statements and information about our expectations for the future, which we refer to as forward-looking information"
Forward-looking information are predictions, plans, estimates or expectations about a company’s future performance, results or events, such as sales forecasts, project timelines, or anticipated costs. It matters to investors because these statements guide expectations but rely on assumptions and uncertain factors—like a weather forecast for a business—so investors should treat them as informed guesses rather than guarantees and consider the risks and possible changes behind the numbers.
production outlook financial
"we do not expect the disruption to impact our 2026 production outlook for Cigar Lake"

FAQ

Why did Cameco (CCJ) temporarily suspend operations at the Cigar Lake mine?
Cameco suspended Cigar Lake mining because Orano’s McClean Lake mill, which processes Cigar Lake ore, shut its sulfuric acid plant for repairs. With limited ore storage and no milling, Cameco paused mining until sufficient acid is available and the mill resumes operation.

How long does Cameco expect the McClean Lake mill disruption to last?
Cameco currently expects the McClean Lake mill to return to operation in approximately two weeks. This timing depends on successfully repairing the sulfuric acid plant and potentially securing sulfuric acid from an alternative source while awaiting replacement parts.

Will the Cigar Lake suspension affect Cameco’s 2026 production outlook?
Cameco states it does not expect the current disruption to impact its 2026 Cigar Lake production outlook. However, it cautions that longer-than-planned repairs or challenges obtaining sulfuric acid could delay mining resumption and, depending on duration, potentially impact the 2026 outlook.

What operational issue occurred at Orano’s McClean Lake mill affecting Cameco (CCJ)?
Orano’s McClean Lake mill experienced operational challenges with its sulfuric acid plant, requiring a shutdown for repairs. Since this mill processes ore from Cameco’s Cigar Lake mine, the acid plant issue directly limits milling capacity and has led Cameco to temporarily suspend mining activities.

How is Cameco addressing sulfuric acid supply for the McClean Lake mill?
Orano is repairing the sulfuric acid plant and assessing options to obtain sulfuric acid from an alternative source. Cameco’s ability to resume Cigar Lake mining on schedule depends on the mill’s access to sufficient acid for processing ore once operations restart.

What forward-looking risks does Cameco highlight regarding Cigar Lake in this update?
Cameco notes risks of a longer suspension if repairs take more time or sourcing alternative sulfuric acid proves difficult. It also references broader risks in its annual information form and MD&A that could affect the 2026 Cigar Lake production outlook if disruptions extend or recur.

AI-generated analysis. How Rhea-AI works. Not financial advice.

See more from StockTitan in Google Search and AI answers. Adds StockTitan as a preferred source · opens Google
Add on Google
Form 6-K: How Foreign Companies Report to the SEC →
 
 

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, DC 20549

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13A-16 OR 15D-16

UNDER THE SECURITIES EXCHANGE ACT OF 1934

For the month of July, 2026

Commission File Number 1-14228

Cameco Corporation

(Translation of Registrant’s Name into English)

2121-11th Street West

Saskatoon, Saskatchewan, Canada S7M 1J3

(Address of Principal Executive Offices)

Indicate by check mark whether the registrant files or will file annual reports under cover Form 20-F or Form 40-F.

Form 20-F         Form 40-F ✓  

 

 
 

Exhibit Index

 

Exhibit No.       Description
99.1    Press Release dated July 1, 2026

 

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

 

Date: July 2, 2026     Cameco Corporation
        By: /s/ R. Liam Mooney       
    R. Liam Mooney
    Senior Vice-President and Chief Legal Officer

Exhibit 99.1

LOGO

 

NEWS RELEASE

 

All amounts in Canadian dollars

unless specified otherwise

  

www.cameco.com

 

   

Saskatoon

 

Saskatchewan

Canada

 

 

Cigar Lake Operation Update

July 1, 2026

Cameco (TSX: CCO; NYSE: CCJ) today announced our Cigar Lake mine in northern Saskatchewan has temporarily suspended operations due to challenges at Orano’s McClean Lake mill, where Cigar Lake ore is processed.

Orano’s McClean Lake mill has encountered operational challenges with its sulfuric acid plant that caused it to shut down in order to repair the issue. Orano is currently working to bring the acid plant back online and is assessing options to obtain acid supply from an alternative source while it waits for replacement parts to complete the repair. With limited ore storage capacity at Cigar Lake, we have temporarily suspended mining activities until sufficient acid is available to allow milling to resume at McClean Lake.

At present, we expect the McClean Lake mill to return to operation in approximately two weeks, and we do not expect the disruption to impact our 2026 production outlook for Cigar Lake. However, there is a risk that the repairs to the acid plant take longer than planned and that mining at Cigar Lake is unable to resume on the expected schedule. Depending on the duration of any additional delays, our 2026 production outlook could be impacted.

Caution about forward-looking information

This news release includes statements and information about our expectations for the future, which we refer to as forward-looking information. Forward-looking information is based on our current views, which can change significantly, and actual results and events may be significantly different from what we currently expect. Examples of forward-looking information in this news release include the temporary nature of the suspension, our expectations regarding the return to regular operations at the McClean Lake mill, and our expectations regarding the impact on our 2026 production outlook for Cigar Lake. Material risks that could lead to different results include the possibility of a longer suspension of operations, due to the repairs to the acid plant taking longer than expected, difficulties in sourcing sulfuric acid from an alternative source, or for other reasons. In presenting this forward-looking information, we have made assumptions which may prove incorrect, including assumptions regarding the future availability of sulfuric acid and length of the period of disruption. Please also see our most recent annual information form, and our most recent annual and quarterly management’s discussion and analysis, for a discussion of other risks that could impact our Cigar Lake 2026 production outlook. Forward-looking information is designed

to help you understand management’s current views of our near-term and longer-term prospects, and it may not be appropriate for other purposes. We will not necessarily update this information unless we are required to by securities laws.

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.

- End -

 

Investor inquiries       Media inquiries
Cory Kos       Veronica Baker
306-716-6782       306-385-5541
cory_kos@cameco.com       veronica_baker@cameco.com

Source: View Original Filing on SEC EDGAR

Filing Exhibits & Attachments

1 document

Press Releases