Denison Mines Corp. reported that the Canadian Nuclear Safety Commission (CNSC) has approved an amendment to the uranium mine and mill licence for the McClean Lake Operation to allow for the expansion of the JEB Tailings Management Facility. The public hearing regarding the application for amendment was held on October 4, 2021 and included submissions from Orano Canada Inc. (Orano), as operator of the McClean Lake Joint Venture (MLJV), as well as input from Denison, CNSC staff, Cameco Corporation, the English River First Nation, the Metis Nation of Saskatchewan, and the Athabasca Joint Engagement and Environmental Subcommittee, among others.

The Commission considered the adequacy of the proposed measures for protecting the environment, the health and safety of persons, national security, and other international obligations. The operation's past operating performance, environmental protection, radiation protection, Indigenous consultation and engagement, decommissioning plans, and other safety and control areas were also examined. The TMF is designed in line with the Global Industry Standard on Tailings Management developed by the International Council of Mining and Metals (ICMM).

The McClean Lake Mill: The McClean Lake property is located on the eastern edge of the Athabasca Basin in northern Saskatchewan, approximately 750 kilometres north of Saskatoon, and is home to the McClean Lake uranium mill. The mill has licensed annual production capacity of 24.0 million pounds U3O8 and is currently operating under a 10-year license expiring in 2027. The mill is contracted to process the ore from the Cigar Lake mine under a toll milling agreement (up to 18.0 million pounds U3O8 per year).

The MLJV is an unincorporated contractual arrangement between Orano with a 77.5% interest and Denison with a 22.5% interest. Orano is the operator of the project. Denison has assessed the potential economic benefit of using the McClean Lake mill as a regional milling centre for the future processing of uranium resources extracted from the Gryphon uranium deposit, on Denison's 95% owned Wheeler River property, and the the Heldeth Túé (THT, formerly J Zone) uranium deposit, on Denison's 66.90% owned Waterbury Lake property.