Mr. David Cates reports

ORANO CANADA AND DENISON ANNOUNCE JV APPROVAL TO RESTART MCCLEAN LAKE MINING OPERATIONS

Orano Canada Inc. and Denison Mines Corp.'s McClean Lake joint venture (MLJV) has approved a restart of uranium mining operations using the joint venture's patented surface access borehole resource extraction (SABRE) mining method. Orano Canada owns a 77.5-per-cent interest and is the operator of the MLJV and Denison owns a 22.5-per-cent interest.

Mining is planned to commence at the McClean North deposit in 2025, with 2024 activities expected to focus on preparations necessary to ready the existing SABRE mining site and equipment for continuous commercial operations, as well as the installation of eight pilot holes for the first mining cavities planned for excavation. The approved budget for this work in 2024 is $7-million (100-per-cent basis).

Approximately 800,000 pounds U3O8 (triuranium octoxide) (100-per-cent basis) are targeted for production from McClean North in 2025, with approximately three million lb U3O8 (100-per-cent basis) identified for potential additional production from a combination of the McClean North and Caribou deposits during the years 2026 to 2030.

Jim Corman, Orano Canada's president and chief executive officer, said: "Our current ability to capitalize on the strengthening uranium and nuclear markets is the result of a long-term investment in R&D within Orano and the MLJV to secure continue d activities at the McClean Lake operation well into the future. The groundwork we do over the course of 2024 is expected to put the MLJV in position to see SABRE in action and to commence production in 2025. It is anticipated that the McClean Lake mill will have sufficient capacity to process this ore, while continuing with committed planned production from Cigar Lake. It's an exciting time for employees, partners and the industry as we return to a focus on growth."

David Cates, Denison's president and chief executive officer, commented: "The restart of uranium mining at McClean Lake is a notable milestone for the MLJV and Denison. Mining at McClean Lake was suspended in 2008 in response to declining uranium prices. During the interim 15 years, the MLJV invested in the development of a proprietary mining method designed to selectively extract high-grade Athabasca basin uranium ores from surface. The successful mining test of the SABRE method in 2021 provided the MLJV with important information about the productivity and cost of SABRE operations. This information suggests an incentive price meaningfully lower than current uranium prices, which has provided the JV with a strong basis to make a restart decision for mining at McClean Lake.

"We would like to thank our colleagues at Orano Canada for their efforts to develop the SABRE method to a commercial-ready state, which has allowed for the joint venture to make the decision to resume production at McClean Lake."

About SABRE

SABRE is the culmination of a mining equipment invention and development initiative that began in 2004 and concluded in 2021 with the completion of multiyear mining test program that successfully excavated approximately 1,500 tonnes of high-value ore. It is a non-entry, surface-based mining method that uses a high-pressure water jet placed at the bottom of a drill hole to excavate a mining cavity. The cuttings from the excavation process are then airlifted to surface, separated and stockpiled. SABRE is viewed as an innovative mining method that has the potential to allow for economic access to relatively small high-grade orebodies in the Athabasca basin that are either too small or too deep to be mined economically by conventional open-pit and/or underground mining methods.

SABRE is unique in that the mining method can be selective and scalable, which has the potential to provide superior flexibility when compared with conventional mining methods, and is thus ideally suited to ever-changing uranium market conditions -- with an expected production ramp-up of months instead of years. The SABRE method has environmental advantages when compared with conventional open-pit or underground mining methods as a result of its less intrusive nature and smaller surface footprint. Reduced water usage and power consumption also contribute to important reductions in greenhouse gas emissions and improved sustainability. Additionally, as a non-entry mining method, radiological exposure for mine workers is minimized.

For additional information about the SABRE mining test completed in 2021, please refer to the Orano Canada and the Denison joint news release dated Nov. 3, 2021.

About McClean Lake

The McClean Lake property is located within the eastern part of the Athabasca basin region in Northern Saskatchewan, approximately 750 kilometres north of Saskatoon. The mineral property consists of four mineral leases covering an area of 1,147 hectares and 13 mineral claims covering an area of 3,111 hectares. The right to mine the McClean Lake deposits was acquired under the mineral leases, as renewed from time to time.

Additional information about the McClean North and Caribou deposits can be found in the technical reports entitled "Technical Report on the Mineral Resource Estimate for the McClean North Uranium Deposits, Saskatchewan," dated Jan. 31, 2007, and the "Technical Report on the Denison Mines Inc. Uranium Properties, Saskatchewan, Canada," dated Nov. 21, 2005, as revised Feb. 16, 2006, respectively, copies of which are available under Denison's profile on SEDAR+ and Denison's website.

Qualified persons

For Orano Canada, the technical information in this release has been reviewed and approved by Louis-Pierre Gagnon, PEng, head of mining engineering, Orano Mining, who is a qualified person in accordance with the requirements of Canadian National Instrument 43-101 Standards of Disclosure for Mineral Projects.

For Denison, the technical information contained in this release has been reviewed and approved by Chad Sorba, PGeo, Denison's vice-president, technical services and project evaluation, and Andrew Yackulic, PGeo, Denison's vice-president, exploration, each of whom is a qualified person in accordance with the requirements of NI 43-101.

About Denison Mines Corp.

Denison is a uranium exploration and development company with interests focused in the Athabasca basin region of Northern Saskatchewan, Canada. Denison has an effective 95-per-cent 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, a feasibility study was completed for Wheeler River's Phoenix deposit as an in situ recovery mining operation, and an update to the previously prepared 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 have advanced significantly, with licensing in progress and a draft environmental impact statement submitted for regulatory and public review in October, 2022.

Denison's interests in Saskatchewan also include a 22.5-per-cent ownership interest in the MLJV, which owns several uranium deposits and the McClean Lake uranium mill, contracted to process the ore from the Cigar Lake mine under a toll milling agreement, plus a 25.17-per-cent interest in the Midwest Main and Midwest A deposits, and a 67.41-per-cent interest in the THT and Huskie deposits on the Waterbury Lake property. The Midwest Main, Midwest A, THT and Huskie deposits are located within 20 kilometres of the McClean Lake mill.

Through its 50-per-cent ownership of JCU (Canada) Exploration Company Ltd., Denison holds additional interests in various uranium project joint ventures in Canada, including the Millennium project (JCU, 30.099 per cent), the Kiggavik project (JCU, 33.8118 per cent) and Christie Lake (JCU, 34.4508 per cent).

Denison's exploration portfolio includes further interests in properties covering approximately 285,000 hectares in the Athabasca basin region.

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