NexGen Breaks Ground on Saskatchewan Uranium Mine That Could Rank Among World's Largest
Construction starting at the Athabasca Basin's Rook I project enters a uranium supply chain where three countries already control three-quarters of global output.
NexGen Energy broke ground on Thursday (2026-08-13) at its Rook I project on the Patterson Lake Peninsula in northern Saskatchewan, officially launching construction on what the company calls the largest development-stage uranium project in Canada and a potential entrant among the world's largest mines.5,6
Global uranium mine production runs between 50,000 and 55,000 tonnes annually according to the latest data, and that output is concentrated in a handful of countries. Kazakhstan, Canada, and Namibia together account for close to three-quarters of world supply, while the top five producers collectively approach 90%. Kazakhstan alone contributes between 40% and 45% of global mine output — a degree of dominance that leaves fuel buyers with limited alternatives when Kazakh supply tightens. Rook I, if it reaches its potential, would expand one of the few geographic alternatives to that concentration.3
NexGen received its final regulatory approval in March, and the groundbreaking brought together Indigenous leaders, federal and provincial representatives, and investors.6 The deposit runs from roughly 300 metres to 700 metres underground and will be reached via two shafts: an 8-metre diameter production shaft and a 5.5-metre diameter exhaust shaft, according to the company's 2021 feasibility study.6
Rook I arrives after a prolonged lull in Canadian mine development. The last uranium mine approved in Canada before the current cycle was Cameco's project; the recent wave of Canadian Nuclear Safety Commission approvals marks a resumption of construction activity the country had largely suspended.2 Analysts say shifting geopolitical conditions are likely to strengthen Saskatchewan's position further as utilities seek supply outside Russian and Kazakh channels.2
Canada's weight in uranium procurement is already substantial. Canada supplied more than 30% of EU uranium imports in 2024, according to available trade data, though that figure covers mined material rather than enrichment services. Replacing Russian enrichment capacity is expected to take years, leaving European buyers exposed even as mine supply grows.4
If Saskatchewan's new developments reach projected capacity alongside other proposed operations, the combined output could hit 39 million pounds of uranium annually, according to analyst projections. Those figures carry standard caveats about mine development timelines: a deep underground operation, shaft-accessed at up to 700 metres, faces execution risk that tends to surface over multi-year build periods rather than in feasibility documents.2,6
The Global X Uranium ETF fell 3.79% in trading recorded as of early Wednesday (2026-08-19), a move that sits alongside a broader volatility uptick — the VIX rose 4.28% on the same session — rather than tracking against Rook I's groundbreaking news. Uranium equity markets and individual project milestones have long moved on different clocks.
Demand fundamentals underlying the project remain intact. The US government has set a target of quadrupling nuclear generating capacity from roughly 100 gigawatts in 2024 to 400 gigawatts by 2050, a scale of ambition that would require sustained fuel supply expansion well beyond current mine capacity.1 Advanced reactor designs add a complication that Rook I cannot directly resolve: many require high-assay low-enriched uranium, or HALEU, not yet commercially available outside Russia. The US has committed up to $2.7 billion to boost domestic HALEU production, but commercial-scale supply remains years away.4
Conventional uranium from Rook I will not address that HALEU gap, which requires additional enrichment steps beyond what standard mine output provides. Utilities planning advanced reactor fuel procurement face that supply problem separately, limiting how directly Saskatchewan's conventional production growth translates to readiness for next-generation reactor fleets.4
For now, the project is at its earliest construction phase. The next concrete signal will be progress on sinking the production shaft against the schedule implied in the 2021 feasibility study. Mine-scale projects at this depth have a habit of revealing their true timelines in the ground, not on paper.6,7