Ontario's Nuclear Momentum: Darlington Proves What Canada Can Build
May 1st, 2026
Two milestones at Ontario's Darlington nuclear site, separated by just weeks, tell the same story: Canada knows how to build nuclear, on time and under budget, and it is doing so right now.
In March 2026, Ontario Power Generation completed the Darlington Refurbishment Project after a decade of work. All four CANDU units have been returned to service, with the final unit completed 968 days after going offline – the fastest of four – and the entire project delivered $150 million under its $12.8 billion budget and four months ahead of schedule. The refurbishment extends Darlington's operational life by 30 years, keeping the plant generating clean baseload electricity into the 2050s. OPG President and CEO Nicolle Butcher was direct about what the achievement means: "We have demonstrated to the world that complex nuclear projects can be completed successfully, ahead of schedule and under budget."
Then, in May 2026, the same site marked another first. The Basemat module – a 953-tonne steel and concrete foundation weighing more than three Airbus A380 aircraft – was lowered 35 meters into the ground at the Darlington New Nuclear Project, marking the first foundation of the first small modular reactor to be built in a G7 country. OPG plans to connect the first SMR unit to the grid by the end of 2030, with four BWRX-300 units planned in total. More than 100 Canadian companies are now part of the SMR supply chain, with over $500 million CAD flowing into Ontario's economy.
Together, these two milestones represent something significant for Canada's nuclear sector broadly. The refurbishment demonstrated that Canada can execute complex nuclear programs with discipline and precision. The SMR construction confirms that the next generation of Canadian nuclear is no longer a plan. It is underway.
For CSMC, this is the industrial and institutional backdrop against which the LEUNR program is advancing. Canada has the regulatory experience, the skilled trades, the supply chain depth, and now the demonstrated project execution capability to support a new generation of nuclear technology developers. The country is not starting from scratch. It is building on decades of hard-won nuclear expertise, and CSMC's LEUNR program is part of that continuum; Taking proven Canadian nuclear heritage into the deployable, portable formats that the next era of energy sovereignty demands.