Canadian Design and Construction Report staff writer
Ontario has reached a major construction milestone on what it calls the G7’s first small modular reactor (SMR) program, with the installation of a 2.1-million-pound basemat module at the Darlington New Nuclear Project site.
Energy and Mines Minister Stephen Lecce announced the achievement Thursday at the CNA2026 Conference, saying the lift represents the first foundation of a new nuclear reactor built in Ontario in more than 30 years.
The basemat for Unit 1 was installed using one of the world’s largest crawler cranes and lowered into place with millimetre precision. The component weighs the equivalent of more than three Airbus A380 aircraft.
Once complete, the Darlington project’s four SMRs are expected to generate 1,200 megawatts of electricity, enough to power about 1.2 million homes.
“Ontario is building the Western World’s first Small Modular Reactor — creating 18,000 good-paying jobs,” Lecce said. “This is a major achievement as the world turns to Ontario to refurbish and build large scale nuclear on-time and on-budget.”
Supply chain contracts awarded include:
- Walters Group of Hamilton, $44.5 million for structural steel
- Marmon Industrial Water of Toronto, $17.8 million for a condensate purification package
- Tractel of Scarborough, $9.9 million for a reactor building weather enclosure
- Hooper Welding of Oakville, $8.8 million for sampling and collection tanks
About 80 per cent of project spending is expected to remain within Ontario.
“With the foundation of the first Small Modular Reactor at the Darlington New Nuclear Project in place, we are now able to begin building up,” said Nicolle Butcher, OPG president and chief executive officer. “This was a milestone months in the making.”
The lift was completed using a crawler crane with a lifting capacity of up to 2,500 tons and more than 200 metres of reach.
The Darlington New Nuclear Project will include four SMRs with a combined output of 1,200 megawatts.
The Ontario government approved construction of the first unit in 2025 after the Canadian Nuclear Safety Commission issued a licence to construct in April 2025. Site preparation began in December 2022, and Ontario announced plans for a four-unit build in July 2023. An application for a licence to operate Unit 1 was submitted in March 2026.
The province and federal government have committed funding to the project, including $1 billion from Ontario’s Building Ontario Fund and $2 billion from the Canada Growth Fund.
