Denison Mines Reports Construction Readiness for Phoenix ISR Project

• CNSC public hearing concluded December 2025; awaiting commission decision on environmental assessment and construction licence
• Provincial environmental assessment approved August 2025; initial earthworks authorisation granted
• Updated initial capital cost estimate of C$600 million represents 20% increase from 2023 feasibility study when adjusted for inflation
• Two-year construction timeline maintained with mid-2028 first production target if approvals received by Q1 2026
• Balance sheet holds over C$700 million in cash, physical uranium, and investments as of September 2025

Denison Mines (TSX:DML; NYSE American:DNN) is a uranium development and exploration company with interests in Saskatchewan's Athabasca Basin region. The company holds a 90% operating interest in the Wheeler River project, which hosts the Phoenix and Gryphon uranium deposits. Additional interests include 22.5% ownership in the McClean Lake Joint Venture, which operates a uranium mill currently processing ore from the Cigar Lake mine under a toll milling agreement, plus interests in the Midwest deposits and other properties totalling approximately 457,000 hectares in the Athabasca Basin.

Federal and Provincial Regulatory Approvals and Construction Authorisation

The two-part Canadian Nuclear Safety Commission public hearing concluded on December 11, 2025, considering Denison's application for environmental assessment approval and the licence to prepare site and construct a mine and mill facility. The commission's decision is pending.

Saskatchewan's Ministry of Environment approved the project's environmental assessment in August 2025 under The Environmental Assessment Act. The province recently granted authorisation to conduct certain activities associated with initial earthworks, including vegetation removal and site drainage works.

Denison has signed impact benefit agreements with Métis Nation-Saskatchewan groups as part of its stakeholder engagement process. The company states it is ready to make a final investment decision and commence construction following receipt of federal approval of the environmental assessment and construction licence.

Updated Initial Capital Cost Estimate and Control Budget

Denison has prepared a Class 2 post-final investment decision capital cost estimate of C$600 million, updating the Class 3 estimate from the 2023 Phoenix Feasibility Study. The updated figure reflects inflation adjustments, cost increases, and project refinements based on 87% total engineering completion.

When adjusted for inflation, the updated capital costs represent a 20% increase from the 2023 feasibility study. Approximately 75% of equipment and materials costs are supported by committed contracts or bids under evaluation, whilst 50% of construction costs are backed by bids under evaluation or in final contract negotiation. The estimate includes C$65 million in contingency funds and owners' reserves.

A technical modification from the 2023 study involves installing large diameter wells throughout the Phase 1 mining area, enabling each well to function as either an injection or recovery well. This change increases initial capital costs but is expected to improve operational flexibility and optimise recovery rates. The project maintains a base case adjusted after-tax NPV to initial capital cost factor of 2.6 to 1, with an internal rate of return of 73%.

Construction Readiness and 2028 First Production Timeline

The procurement process for planned 2026 construction contracts is approaching completion, with contract awards pending and expected in early 2026. Following contractor onboarding, Denison expects to achieve a level 4 detailed task-level construction schedule.

Shipment dates for key long-lead items, including electrical distribution infrastructure such as the main site transformer, substation high voltage equipment, switchgear, and substation electrical house, remain on schedule. Detailed design engineering stands at 87% complete, with 92% of primary engineering deliverables issued for construction. Remaining engineering work is forecast for completion by Q2 2026.

If construction approvals are received by the end of Q1 2026, construction can commence as planned, maintaining the mid-2028 target for first production. The project is designed for a two-year construction period.

Next Steps

Denison awaits the CNSC decision on environmental assessment approval and construction licence, expected in Q1 2026. Upon receipt of federal approvals, the company intends to make its final investment decision and begin construction activities. Contract awards for major construction packages will follow, with earthworks activities to commence under recently granted provincial permissions.

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