Denison Reports CNSC Hearing Dates for Phoenix ISR Project

Press Release

TORONTO, Feb. 27, 2025 Denison Mines Corp. (“Denison” or the “Company”) (TSX: DML) (NYSE American: DNN) is pleased to announce that the Canadian Nuclear Safety Commission (“CNSC”) Registrar has set the schedule for the CNSC public hearing (“Hearing”) for the Wheeler River Uranium Project (“Wheeler River”, or the “Project”). The Hearing is scheduled to be held in two parts (October 8, 2025, and December 8 to 12, 2025) and represents the final step in the federal approval process for the Project’s Environmental Assessment (“EA”) and Licence to Prepare and Construct a Uranium Mine and Mill (“Licence”). View PDF Version

Based on this schedule, if the CNSC makes a prompt decision to approve the Project following the completion of the Hearing, the Company expects to be able to commence site preparation and construction activities for the Phoenix In-Situ Recovery (“ISR”) project in early 2026.

The announcement of the Hearing schedule follows the successful completion of multiple key regulatory milestones in late 2024, including (i) completion of the technical review phase of the federal EA approval process in November, (ii) acceptance by the CNSC of the Company’s final Environmental Impact Statement (“EIS”) for the Project in December, and (iii) the CNSC’s determination of the sufficiency of Denison’s Licence application, also in November. These accomplishments indicate that the CSNC staff support the advancement of the Project and are transitioning their efforts to prepare an evidence-based summary report for the Commission members that will govern the Hearing and render their decision on the EA and Licence once the Hearing is complete.

David Cates, President and CEO of Denison commented, “The scheduling of the Hearing and acceptance of the final federal EIS by the CNSC represent significant additional achievements for Denison in our efforts to obtain the regulatory approvals necessary to commence construction of the Phoenix ISR uranium mining operation. Importantly, obtaining clarity on the Hearing schedule significantly reduces uncertainty regarding the timeline for Federal project approvals and allows our operations team to finalize our construction planning efforts with greater precision. With the potential to commence construction in early 2026, we expect to be able to maintain our target of achieving first production from Phoenix by the first half of 2028.”

About Denison

Denison is a leading uranium mining, development, and exploration company with interests focused in the Athabasca Basin region of northern Saskatchewan, Canada. Denison has an effective 95% interest in its flagship Wheeler River Uranium Project, which is the largest undeveloped uranium project in the infrastructure rich eastern portion of the Athabasca Basin region of northern Saskatchewan. In mid-2023, the Phoenix feasibility study was completed for the Phoenix deposit as an ISR mining operation, and an update to the previously prepared 2018 Pre-Feasibility Study (‘PFS’) was completed for Wheeler River’s Gryphon deposit as a conventional underground mining operation. Based on the respective studies, both deposits have the potential to be competitive with the lowest cost uranium mining operations in the world. Permitting efforts for the planned Phoenix ISR operation commenced in 2019 and several notable milestones were achieved in 2024 with the submission of federal licensing documents and the acceptance of the final form of the project’s Environmental Impact Statement by the Province of Saskatchewan and the Canadian Nuclear Safety Commission.

Denison’s interests in Saskatchewan also include a 22.5% ownership interest in the McClean Lake Joint Venture (‘MLJV’), which includes unmined uranium deposits (planned for extraction via the MLJV’s SABRE mining method starting in 2025) and the McClean Lake uranium mill (currently utilizing a portion of its licensed capacity to process the ore from the Cigar Lake mine under a toll milling agreement), plus a 25.17% interest in the Midwest Joint Venture (‘MWJV’)’s Midwest Main and Midwest A deposits, and a 69.44% interest in the Tthe Heldeth Túé (‘THT’) and Huskie deposits on the Waterbury Lake Property (‘Waterbury’). The Midwest Main, Midwest A, THT and Huskie deposits are located within 20 kilometres of the McClean Lake mill. Taken together, Denison has direct ownership interests in properties covering ~384,000 hectares in the Athabasca Basin region.

Additionally, through its 50% ownership of JCU (Canada) Exploration Company, Limited (‘JCU’), Denison holds interests in various uranium project joint ventures in Canada, including the Millennium project (JCU, 30.099%), the Kiggavik project (JCU, 33.8118%) and Christie Lake (JCU, 34.4508%).

In 2024, Denison celebrated its 70th year in uranium mining, exploration, and development, which began in 1954 with Denison’s first acquisition of mining claims in the Elliot Lake region of northern Ontario.

Follow Denison on Twitter @DenisonMinesCo

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