Denison Announces Final Investment Decision for the Phoenix In-Situ Recovery Uranium Mine and Plans to Start Construction in March 2026

Rhea-AI Summary

Denison (NYSE: DNN) announced a Final Investment Decision to build the Phoenix in-situ recovery uranium mine with site preparation and construction planned to start in March 2026. The company expects construction to take ~two years and targets first production by mid-2028. Phoenix is part of the Wheeler River joint venture where Denison is the operator with 90% JV interest and an effective 95% interest in Wheeler River. Provincial and federal environmental approvals and a licence to prepare site & construct were received in July 2025 and February 2026.

Positive

• Final Investment Decision made to proceed with Phoenix construction (Feb 24, 2026)
• Site preparation and construction planned to begin in March 2026
• Targeted first production by mid-2028 after ~two-year construction
• Received provincial EA approval (July 2025) and federal EA/licence (Feb 2026)
• Denison holds 90% operator JV interest in Phoenix and effective 95% interest in Wheeler River

Negative

• Approximately two-year construction schedule exposes project to execution and timing risk
• Updated initial capital cost disclosed (Jan 2, 2026) creates potential capital-cost uncertainty for investors

Key Figures

Share price: $4.30 Construction duration: approximately two years First production target: mid-2028 +5 more

8 metrics

Share price $4.30 Pre-news close around FID announcement

Construction duration approximately two years Phoenix ISR mine build timeline

First production target mid-2028 Phoenix ISR uranium mine objective

Wheeler River interest 90% Denison / 10% JCU Joint venture ownership of Wheeler River

McClean Lake JV interest 22.5% Denison ownership in McClean Lake Joint Venture

Midwest JV interest 25.17% Denison interest in Midwest Main and Midwest A deposits

THT & Huskie interest 70.55% Denison ownership on Waterbury Lake Property

Land package ~457,000 hectares Direct ownership in Athabasca Basin region

Market Reality Check

Price: $4.30 Vol: Volume 38,295,653 is belo...

normal vol

$4.30 Last Close

Volume Volume 38,295,653 is below the 20-day average of 50,016,691, suggesting a moderate rather than extreme reaction. normal

Technical Shares at $4.30 are trading above the 200-day MA of $2.55 and sit 2.93% below the 52-week high of $4.43.

Peers on Argus

DNN gained 2.63% as uranium peers also moved higher: UUUU +8.53%, NXE +4.56%, UE...

1 Down

DNN gained 2.63% as uranium peers also moved higher: UUUU +8.53%, NXE +4.56%, UEC +3.32%, LEU +4.95%, URG +4.27%. The move aligns with broader uranium strength.

Common Catalyst Broader uranium sector strength rather than company-specific news alone appears to be supporting gains.

Historical Context

5 past events · Latest: Feb 19 (Positive)

Pattern 5 events

Date	Event	Sentiment	Move	Catalyst
Feb 19	Regulatory approval	Positive	+1.1%	Final federal approval and construction licence for Phoenix ISR mine.
Feb 17	Construction contract	Positive	+0.8%	Award of construction management contract for Phoenix mine build-out.
Jan 28	JV drilling start	Positive	+9.4%	Start of winter 2026 drilling on Darby and MLN joint ventures.
Jan 21	JV drilling plans	Positive	+1.6%	Announcement of winter 2026 drill programs at Darby and MLN JVs.
Jan 08	Infrastructure power	Positive	+0.0%	Completion of SaskPower transmission line supplying grid power to Phoenix.

Pattern Detected

Recent news around Phoenix and joint ventures has generally seen modestly positive or flat price reactions following announcements.

Recent Company History

Over the last several weeks, Denison reported multiple milestones at Wheeler River and its joint ventures. Federal approval and a construction licence for Phoenix on Feb 19, 2026, and a construction management contract on Feb 17, 2026, both saw small positive moves. Joint-venture drilling updates in late January produced stronger upside on Jan 28, 2026. Grid power completion in early January had a flat reaction. Today’s FID decision follows this steady de-risking of Phoenix toward first production by mid-2028.

Market Pulse Summary

This announcement formalizes Denison’s transition from permitting to construction at the Phoenix ISR...

Analysis

This announcement formalizes Denison’s transition from permitting to construction at the Phoenix ISR uranium mine, with work expected to take approximately two years and targeting first production by mid-2028. It follows recent federal approvals and infrastructure build-out, reinforcing a de-risking trend at Wheeler River. Investors may focus on execution against the construction schedule, capital discipline, and how Phoenix fits alongside Denison’s broader Athabasca Basin portfolio and joint-venture interests.

Key Terms

in-situ recovery, isr, environmental assessment, ni 43-101, +1 more

5 terms

in-situ recovery technical

"Final Investment Decision ("FID") to proceed with the construction of the Phoenix In-Situ Recovery ("ISR") uranium mine"

In-situ recovery is a mining method that extracts a valuable material by dissolving it underground and pumping the solution to the surface instead of digging or blasting rock. For investors, it matters because this approach often lowers upfront construction costs, shortens development time and reduces visible land disturbance, but it also brings regulatory, environmental and groundwater risks that can affect project timelines, operating costs and valuation.

isr technical

"Phoenix In-Situ Recovery ("ISR") uranium mine ("Phoenix" or the "Project")"

ISR stands for socially responsible investing (from the French phrase Investissement Socialement Responsable) and means choosing stocks, bonds or funds based on environmental, social and governance criteria in addition to financial return. Like picking a brand that matches your values, ISR matters to investors because it helps align portfolios with personal or institutional priorities, can reduce exposure to companies with regulatory or reputational risks, and can influence demand and valuation for firms deemed more sustainable.

environmental assessment regulatory

"approval of the Project's Environmental Assessment ("EA") by the Province of Saskatchewan"

An environmental assessment is a process that evaluates how a project or activity might impact the natural surroundings, such as air, water, land, and wildlife. It helps identify potential environmental risks and ensures that any negative effects are managed or minimized. For investors, this assessment provides insight into the sustainability and long-term viability of projects, which can influence their financial decisions and risk management.

ni 43-101 regulatory

"technical report titled "NI 43-101 Technical Report on the Wheeler River Project Athabasca Basin, Saskatchewan, Canada""

A Canadian regulatory standard that sets the rules for how mining and exploration companies must report mineral resources and reserves, requiring technical reports prepared or signed off by an independent, certified expert. It matters to investors because it creates a consistent, transparent “inspection report” for mining projects, making it easier to compare prospects, judge the reliability of claims, and assess geological and financial risk before investing.

joint venture financial

"and is a joint venture between Denison (90% and operator) and JCU (Canada) Exploration Company Limited ("JCU", 10%)"

A joint venture is when two or more companies team up to work on a specific project or business idea, sharing both the risks and the rewards. It’s like friends starting a lemonade stand together—each contributes resources and they split the profits, making it easier to succeed than going alone.

AI-generated analysis. Not financial advice.

TORONTO, Feb. 24, 2026 /PRNewswire/ - Denison Mines Corp. ("Denison" or the "Company") (TSX: DML) (NYSE American: DNN) is pleased to announce that its Board of Directors has made a Final Investment Decision ("FID") to proceed with the construction of the Phoenix In-Situ Recovery ("ISR") uranium mine ("Phoenix" or the "Project"), and that site preparation and construction activities for Phoenix are planned to commence in March 2026. PDF Version 

David Cates, President and CEO of Denison commented, "Making a Final Investment Decision and the upcoming initiation of construction activities at Phoenix mark the beginning of a new era in Denison's history and the Canadian uranium mining sector.

Our teams have worked diligently over the last several years to bring Phoenix to a construction-ready state, obtain provincial and federal approvals, procure long-lead materials, and secure financing to be in a position to make this landmark decision and commence construction of the first new large-scale Canadian uranium mine in over two decades.  With construction anticipated to take approximately two years, commencing construction in March is expected to allow us to maintain our objective to achieve first production from Phoenix by mid-2028 and ultimately position Denison as one of the few uranium suppliers globally who will be able to provide a sizeable new source of uranium production before the end of the decade." 

About Wheeler River 

Wheeler River is the largest undeveloped uranium project in the infrastructure-rich eastern portion of the Athabasca Basin region, in northern Saskatchewan. The project is host to the high-grade Phoenix and Gryphon uranium deposits, discovered by Denison in 2008 and 2014, respectively, and is a joint venture between Denison (90% and operator) and JCU (Canada) Exploration Company Limited ("JCU", 10%). In August 2023, Denison filed a technical report (the "Wheeler River Report") summarizing the results of (i) Phoenix FS; and (ii) a cost update to the 2018 Pre-Feasibility Study for conventional underground mining of the basement-hosted Gryphon uranium deposit. 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, culminating in the July 2025 approval of the Project's Environmental Assessment ("EA") by the Province of Saskatchewan and the February 2026 approval of the Project's EA and the grant of the Licence to Prepare Site & Construct by the Canadian Nuclear Safety Commission. More information is available in the technical report titled "NI 43-101 Technical Report on the Wheeler River Project Athabasca Basin, Saskatchewan, Canada" dated August 8, 2023 with an effective date of June 23, 2023, and an update to estimated Phoenix initial capital costs disclosed by press release dated January 2, 2026, copies of which are available on Denison's website and under its profile on SEDAR+ at www.sedarplus.ca and on EDGAR at www.sec.gov/edgar.

About Denison

Denison is a leading uranium exploration and development company with interests focused in the Athabasca Basin region of northern Saskatchewan, Canada. In addition to Denison's effective 95% interest in its flagship Wheeler River Project, Denison's interests in Saskatchewan include a 22.5% ownership interest in the McClean Lake Joint Venture ("MLJV"), which includes unmined uranium deposits (with mining at McClean North deposit via the MLJV's SABRE mining method having commenced 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's Midwest Main and Midwest A deposits, and a 70.55% interest in the Tthe Heldeth Túé ("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. Taken together, Denison has direct ownership interests in properties covering ~457,000 hectares in the Athabasca Basin region.

Additionally, through its 50% ownership of 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

CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS

Certain information contained in this news release constitutes 'forward-looking information', within the meaning of the applicable United States and Canadian legislation, concerning the business, operations and financial performance and condition of Denison. Generally, these forward-looking statements can be identified by the use of forward-looking terminology such as 'potential', 'plans', 'expects', 'budget', 'scheduled', 'estimates', 'forecasts', 'intends', 'anticipates', or 'believes', or the negatives and/or variations of such words and phrases, or state that certain actions, events or results 'may', 'could', 'would', 'might' or 'will' 'be taken', 'occur' or 'be achieved'.

In particular, this news release contains forward-looking information pertaining to Denison's current expectations, intentions and objectives with respect to Wheeler River and Phoenix, including the Company's outlook generally with respect to ISR mine development and operations on the Wheeler River property; the status of a final investment decision; timing, readiness and mobilization for site clearing and construction, and construction planning; current outlook for the achievement of first production; the results of, and estimates, assumptions and projections provided in, the technical report for Wheeler River and the interpretations and expectations with respect thereto, including the updated initial capital cost estimate; and expectations regarding its joint venture ownership interests and the continuity of its agreements with its partners and third parties.

Forward looking statements are based on the opinions and estimates of management as of the date such statements are made, and they are subject to known and unknown risks, uncertainties and other factors that may cause the actual results, level of activity, performance or achievements of Denison to be materially different from those expressed or implied by such forward-looking statements. For example, the results and underlying assumptions and interpretations of its technical studies and cost forecasting may not be maintained after further testing, procurement, or operations, or be representative of actual conditions at the Project or within the applicable deposits. In addition, Denison may decide or otherwise be required to discontinue work if it is unable to maintain or otherwise secure the necessary resources (such as testing facilities, capital funding, joint venture approvals, regulatory approvals, etc.). Denison believes that the expectations reflected in this forward-looking information are reasonable but no assurance can be given that these expectations will prove to be accurate and results may differ materially from those anticipated in this forward-looking information. For a discussion in respect of risks and other factors that could influence forward-looking events, please refer to the factors discussed in Denison's Annual Information Form dated March 28, 2025 under the heading 'Risk Factors' or in subsequent quarterly financial reports. These factors are not, and should not be construed as being, exhaustive.

Accordingly, readers should not place undue reliance on forward-looking statements. The forward-looking information contained in this news release is expressly qualified by this cautionary statement. Any forward-looking information and the assumptions made with respect thereto speaks only as of the date of this news release. Denison does not undertake any obligation to publicly update or revise any forward-looking information after the date of this news release to conform such information to actual results or to changes in Denison's expectations except as otherwise required by applicable legislation.

View original content to download multimedia:https://www.prnewswire.com/news-releases/denison-announces-final-investment-decision-for-the-phoenix-in-situ-recovery-uranium-mine-and-plans-to-start-construction-in-march-2026-302696327.html

SOURCE Denison Mines Corp.

FAQ

When will Denison (DNN) begin construction of the Phoenix uranium mine?

Construction is planned to commence in March 2026. According to the company, site preparation and construction activities are scheduled to start that month and progress over an approximately two-year timeline.

What is Denison's (DNN) expected timeline to first production at Phoenix?

Denison expects first production by mid-2028. According to the company, a roughly two-year construction period beginning March 2026 supports the mid-2028 production objective.

What approvals has Denison (DNN) received for the Phoenix ISR project?

Phoenix received provincial EA approval in July 2025 and a federal EA plus licence in February 2026. According to the company, these approvals permit site preparation and construction to proceed.

What ownership stake does Denison (DNN) hold in the Wheeler River Phoenix project?

Denison is the project operator with a 90% joint-venture interest and an effective 95% interest in Wheeler River. According to the company, the JV structure places Denison in operational control.

How long is construction expected to take for Denison's (DNN) Phoenix mine?

Construction is anticipated to take approximately two years. According to the company, this schedule supports targeting first production by mid-2028 if activities begin in March 2026.

Did Denison (DNN) update Phoenix capital costs and what does that mean for investors?

Denison disclosed an update to estimated initial capital costs on Jan 2, 2026. According to the company, the update provides revised project cost information and may affect financing considerations.