Ontario Begins Construction on G7’s First Small Modular Reactor at Darlington

CLARINGTON — Ontario is making history as the first jurisdiction in the G7 to begin construction on a small modular nuclear reactor (SMR), with the provincial government officially approving Ontario Power Generation’s (OPG) plan to build the first of four SMRs at the Darlington site.

The new BWRX-300 reactor — the first of its kind in the G7 — will generate enough clean electricity to power 300,000 homes, with the entire four-unit buildout expected to produce 1,200 megawatts, enough to power 1.2 million homes. The SMRs are seen as a key solution to meeting the province’s rising energy demands, which are projected to increase by 75 per cent by 2050.

“This is a historic day for Canada as we start construction on the first small modular reactor in the G7,” said Stephen Lecce, Minister of Energy and Mines. “This nation-building project will be led by Canadian workers using Canadian steel, concrete and materials.”

We gave the green light to build the G7’s first Small Modular Reactor, right here in Ontario.

This nation-building project will create 18,000 Canadian jobs, with each SMR being built with Ontario concrete, steel, and components — 80% #MadeInOntario alone.

Because of this… pic.twitter.com/v9m7REKwee

— Stephen Lecce (@Sflecce) May 8, 2025

Jobs, Economic Growth, and Clean Energy Security

The Darlington New Nuclear Project is expected to:

• Create up to 18,000 jobs in construction, operation, and maintenance.

• Add $500 million annually to Ontario’s economy.

• Inject $38.5 billion into Canada’s GDP over the next 65 years.

More than 80 Ontario companies have signed on to deliver the project, positioning the province as a global leader in nuclear innovation. The project’s supply chain is overwhelmingly local, with 80% of spending staying in Ontario.

The government is working with GE Hitachi on additional agreements that will be announced in the coming months and exploring equity partnerships with Williams Treaties First Nations — a first-of-its-kind model in Canadian nuclear energy development.

Why SMRs?

SMRs like the BWRX-300 offer a compact, scalable solution for baseload power, using commercially available uranium to produce stable, emissions-free electricity. The province’s energy grid operator, the Independent Electricity System Operator (IESO), has confirmed that the SMR option offers lower risk and cost than the alternative: building 8,900 MW of wind and solar paired with batteries.

The first unit will cost $6.1 billion, with $1.6 billion allocated to shared infrastructure. Costs are projected to decline for subsequent reactors due to efficiencies — mirroring the cost trajectory seen in the successful Darlington Refurbishment Project.

OPG began site prep in December 2022, secured federal construction licensing in April 2025, and is now moving into full-scale construction.

A Made-in-Ontario Global First

This project makes Ontario the first jurisdiction in the G7 to launch SMR construction and puts Canadian companies at the forefront of the global SMR market. The province is already collaborating with Alberta, Saskatchewan, and New Brunswick to expand SMR deployment nationwide.

The Darlington SMRs are a cornerstone of Ontario’s Affordable Energy Future, the Ford government’s strategy to ensure long-term energy reliability as demand for housing, transit, and electric vehicles continues to grow.

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