Rook I site infrastructure and earthworks advancing in Saskatchewan’s Athabasca Basin.
By Sonny Rollins
NexGen Energy has broken ground on its Rook I uranium mine and mill in northern Saskatchewan, moving one of Canada’s largest new uranium projects from permitting into full construction.
The company plans to spend approximately C$2.2 billion over a four-year build. Once operational, Rook I is designed to produce up to 30 million pounds of uranium annually, a volume that CBC and World Nuclear News report could represent roughly one-fifth of current global uranium supply.
The project is located on the Patterson Lake peninsula in the southwestern Athabasca Basin, about 130 to 155 kilometres north of La Loche. It is centred on NexGen’s high-grade Arrow deposit and is expected to become one of the largest single uranium sources under development globally.
The construction milestone comes as utilities and governments seek greater security of nuclear fuel supply. Demand expectations are being supported by reactor restarts, new-build programmes, electrification and rising electricity consumption from data centres and artificial intelligence infrastructure. But Rook I’s effect on the market will depend on execution over the next four years and on NexGen securing a separate licence to operate.
Groundbreaking starts a four-year build
NexGen held a groundbreaking ceremony at the site in August, bringing together company representatives, contractors, Indigenous leaders, federal and provincial officials and community members.
According to World Nuclear News, about 300 people are currently working at the site. Major earthworks and surface infrastructure are advancing, while more than 575,000 tonnes of aggregate have been crushed and stockpiled by a business partnered with Clearwater River Dene Nation.
The early work is focused on establishing the infrastructure required for a remote, deep underground mine. NexGen’s project updates list earthworks, shaft and mill pads, a diffuser road, temporary water treatment and shaft preparation among the activities underway.
The site’s existing 914-metre airstrip is also being expanded to 1,780 metres. World Nuclear News reported that the longer runway is expected to be completed by December, improving access for construction materials, workers and future operations.
Airstrip earthworks are part of Rook I’s remote-site infrastructure build.
Full shaft development is expected to begin in 2027, after the current phase of surface preparation and pad construction. NexGen is targeting first production around 2030, based on the company’s four-year construction schedule.
The timing leaves limited room for delays in shaft sinking, underground development, mill construction, commissioning or regulatory reviews. For operators and suppliers, the project’s transition into construction should create a multi-year procurement and contracting programme across underground mining, hoisting, processing, power, water management, logistics and automation.
What the project licence allows
The Canadian Nuclear Safety Commission issued NexGen a Licence to Prepare Site and Construct on March 4, 2026. The licence is valid until March 31, 2036.
The approval is significant, but it does not authorize uranium production. The licence permits site preparation and construction under Canada’s Nuclear Safety and Control Act. NexGen must apply for a separate operating licence, which would be considered through a future CNSC hearing and decision.
The distinction matters for investors, contractors and policymakers. Rook I has cleared the principal federal construction hurdle, but commercial production remains subject to further regulatory approval. The operating application will need to address the completed facility, operating systems, environmental controls, worker protection and emergency arrangements.
The CNSC’s Rook I facility page lists the project status as “site preparation and construction.” It also identifies a projected production rate of up to 11.5 million kilograms of uranium per year if operation is authorized.
The federal approval followed Saskatchewan’s provincial environmental assessment approval in 2023. World Nuclear News reported that the provincial decision allowed NexGen to advance development after a public and technical review. The federal and provincial processes were conducted separately, although agencies shared information during the assessment process.
The construction licence therefore represents a regulatory transition rather than the end of permitting. NexGen can build the project, but it cannot operate the mine and mill until the CNSC grants the next authorization.
A deep underground uranium project
Rook I will use two vertical shafts to access the Arrow deposit and support underground production.
NexGen’s project information states that the production shaft will extend to approximately 630 metres, while the exhaust shaft will reach about 530 metres. The production shaft will transport workers, equipment and ore. The second shaft will provide ventilation and a separate egress route.
The deposit is planned to be mined using conventional long-hole stoping. Ore will be hoisted to the surface for processing in the project’s mill, while paste tailings are planned to be placed underground in mined-out stopes and chambers rather than stored in a conventional surface tailings facility.
Deep-level shaft infrastructure will be central to the Rook I mine plan.
The project’s feasibility design also incorporates automated and tele-remote equipment. NexGen says this approach is intended to improve safety and productivity in underground areas while allowing ore to be extracted and moved through a controlled operating system.
The Arrow deposit contains measured and indicated resources of approximately 256.7 million pounds of U₃O₈, according to World Nuclear News, including a probable reserve of about 239.6 million pounds at an average grade of 2.37% U₃O₈. The resource figures and mine-plan assumptions may change as development advances, further drilling is completed and operating approvals are reviewed.
Supply implications for uranium markets
Rook I’s planned output is large relative to the current uranium production base. NexGen and media reports have described the project’s 30-million-pound annual capacity as equivalent to around 20% of present global uranium supply and more than half of Western supply.
Those comparisons are best understood as project-scale indicators rather than an immediate change in available fuel. Rook I is still several years from expected production, and the market impact will depend on:
- The pace of shaft sinking and underground mine development.
- Construction and commissioning of the mill and water-treatment systems.
- NexGen’s ability to complete financing and long-lead procurement.
- The timing of the future CNSC operating licence.
- The structure of contracts with utilities and other fuel-cycle participants.
- Production performance during ramp-up.
The project could nevertheless become an important source of new Western uranium. Canada already has an established uranium industry in Saskatchewan, including high-grade operations in the Athabasca Basin. Rook I would add a large development-stage project to that regional base at a time when utilities are extending reactor lifetimes and governments are emphasizing reliable, politically stable fuel supply.
The addition would also increase the importance of infrastructure around northern Saskatchewan. The expanded airstrip, roads, water systems, camp facilities and local contracting network will determine how efficiently the site can be built and operated.
Underground development will require coordinated drilling, ventilation and ground-support systems.
Indigenous partnerships and regional employment
The project is situated on Treaty 8 territory, within the Métis Homeland and areas connected to Denesųłiné, Cree and Métis communities.
CBC reported that NexGen has signed benefit agreements with Clearwater River Dene Nation, Birch Narrows Dene Nation, Buffalo River Dene Nation and Métis Nation–Saskatchewan. The agreements are confidential, but typically cover employment and training, contracting opportunities and financial benefits.
NexGen expects Rook I to create approximately 459 full-time operating jobs over a projected 24-year operating life. The construction period is expected to support additional employment across civil works, logistics, accommodation, equipment maintenance and engineering.
For northern communities, the project’s impact will depend not only on the headline job count but also on whether training, procurement and business participation remain integrated into the construction schedule. The company has also partnered with Clearwater River Dene Nation and Métis Nation–Saskatchewan Local 39 on a 59-bed hotel in La Loche.
What to watch next
The next major milestones are likely to be the completion of surface works, the airstrip expansion, shaft sinking in 2027 and progress on the mill and underground infrastructure.
The most important regulatory milestone will be NexGen’s future application for an operating licence. Until that approval is obtained, Rook I remains a permitted construction project rather than a producing uranium mine.
For the uranium market, the central question is whether NexGen can deliver a project of exceptional scale on its current schedule. If construction progresses as planned, Rook I could become a major addition to global and Western uranium supply near the start of the next decade. If development or licensing slips, the project’s contribution would arrive later: leaving utilities to rely longer on existing mines, secondary supplies and new projects elsewhere.
Sources: CBC News, World Nuclear News, Canadian Nuclear Safety Commission, and NexGen Energy.