Name of the Project
Wheeler River uranium project.

Location
Northern Saskatchewan, Canada.

Project Owner/s
Wheeler River Joint Venture (JV), comprising uranium project developer Denison Mines (90%), and exploration and development company JCU (Canada) Exploration Company (10%).

Project Description
Wheeler River is the biggest undeveloped uranium project in the eastern portion of the Athabasca basin. The project hosts two high-grade uranium deposits: Phoenix and Gryphon.

Phoenix
Phoenix is planned to be the first uranium ISR mining operation in the Athabasca basin region. 

The June 2023 feasibility confirmed robust economics and the technical viability of an in situ recovery (ISR) uranium mining operation with low initial capital costs and a high rate of return.

The project has been divided into five phases, with 74 extraction wells, 172 injection wells and 22 monitoring wells.

Mining is planned to occur over a ten-year period, spanning 11 calendar years, with partial years of production occurring in the first and final calendar year of the production plan. Progressive reclamation and decommissioning are planned to start in each phase of the ore zone once production has ceased.

The Phoenix feasibility study calls for the construction of a processing plant on the Wheeler River site, which has been designed to receive uranium-bearing solution (UBS) from the wellfield for processing to a finished yellowcake product that meets industry standards.

Once the UBS is received at the processing plant, removal of impurities, such as iron and radium, will occur through Stage 1 (iron/radium) precipitation. The purified leach solution will feed the Stage 2 yellowcake precipitation circuit, after which the yellowcake product is dried and packaged for shipment. The processing plant has been designed based on an average uranium head grade of the UBS recovered from the wellfield of 22 g/ℓ and is expected to recover 96.5% of the uranium feed contained in the UBS after a six-month ramp-up period of the plant. 

Taken together with planned subsequent recoveries of uranium contained in the Stage 1 (iron/radium) precipitation product, total recovered uranium of 56.2-million pounds uranium is planned to be available for sale – representing a combined 99% recovery rate.

Gryphon
The Gryphon project prefeasibility study update demonstrates that the underground development is a positive potential future use of cash flows generated from Phoenix, as it is able to leverage existing infrastructure to provide an additional source of low-cost production.

Access to the deposit is planned to be through a primary production shaft with a diameter of 6.1 m, installed using a blind boring method to a depth of 550 m below surface. A ventilation shaft, with a diameter of 5.8 m, is also planned to be excavated through blind boring to a depth of 550 m. Both shafts will be lined with a watertight steel/concrete composite liner.

Access from the shaft to the mine workings will be through a single ramp, located on the hanging wall of the deposit. Mining is planned to consist of conventional underground longhole stoping mining methods, with longitudinal retreat expected as the main approach. Mined stopes will be backfilled using a combination of rockfill, cemented rockfill and hydraulic fill.

Overall, 49.7-million pounds of uranium over 1.26-million tonnes grading 1.8% uranium are planned to be extracted from Gryphon over an estimated 6.5-year mine life.

While the proposed Gryphon mine has the potential to exceed this rate of production, the study constrains mine production based on the expected processing capacity of nine-million pounds of uranium a year.

Potential Job Creation
Not stated.

Net Present Value/Internal Rate of Return
Phoenix has a base case pretax net present value (NPV), at an 8% discount rate, of $2.34-billion (100% ownership-basis) and an internal rate of return (IRR) of 105.9%, with a payback of ten months.

Gryphon has a base case pretax NPV, at an 8% discount rate, of $1.43-billion (100% basis) and an IRR of 41.4%, with a payback of 20 months.

Capital Expenditure
Estimated preproduction capital costs for Phoenix are estimated below $419.4-million.

Initial capital costs for Gryphon are estimated at $737.4-million.

Planned Start/End Date
Denison is aiming for first production from the Phoenix ISR operation by 2027/28.

Latest Developments
Denison Mines is advancing engineering and regulatory efforts for its planned Phoenix project, targeting a final investment decision by mid-2025.

The Canadian Nuclear Safety Commission’s review of the Wheeler river draft environmental-impact statement (EIS) is approaching completion, with nearly all outstanding information requests resolved.

“Given the positive progress with the federal review, we have opted to submit a final provincial environmental impact statement to the Saskatchewan Ministry of Environment to move forward with obtaining formal approval from the province,” Denison CEO David Cates has stated.

Denison is also advancing its engineering efforts, having completed 45% of the total engineering work by the end of the third quarter of 2024. The company is ramping up long-lead procurement activities, with C$21-million in milestone payments or commitments already made towards initial project capital expenditures, and several additional procurement packages under way.

Key Contracts, Suppliers and Consultants
Wood Canada, WSP USA Environment and Infrastructure Inc, SRK Consulting (Canada) Inc and Newmans Geotechnique Inc (Phoenix feasibility study); and Engcomp Engineering and Computing Professionals Inc, SLR International Corporation, Stantec Consulting and Hatch (Gryphon prefeasibility study update).

Contact Details for Project Information
Denison Mines, tel +1416 979 1991, fax +1416 979 5893 or email info@denisonmines.com.