Ontario Delivers Darlington Refurbishment Project Ahead of Schedule and Under Budget

February 2, 2026

World’s largest completed nuclear refurbishment will generate secure, reliable, clean electricity to power 3.5 million homes and support 14,200 workers for the next 30 years

 Today, Minister Stephen Lecce announced a significant milestone in the government’s plan to protect Ontario with the completion of construction on the refurbishment of the Darlington Unit 4 nuclear reactor. The unit is now complete and will be returning to service four months ahead of schedule, the overall refurbishment project coming in $150 million under budget. Originally expected to return to power in August 2026, the unit has received approval from the Canadian Nuclear Safety Commission to enter the initial power testing, which is expected to begin on February 12, and will be at full power shortly after. Refurbishment and continued operations over the next 30 years at Darlington is expected to generate up to $90 billion in economic benefits for Ontario, support approximately 14,200 jobs and produce enough clean electricity to power 3.5 million homes.

“Ontario is proving to the world that we can deliver major nuclear energy projects on-time and on-budget,” said Stephen Lecce, Minister of Energy and Mines. “Last year we returned another refurbished unit at Darlington four months ahead of schedule, and today we’ve done it again. Completing the full Darlington refurbishment on-time and under-budget is a made-in-Canada win for our economy, generating $90 billion in economic benefits and supporting 14,200 good-paying jobs. In a world of uncertainty, our government is doubling down on Canadian nuclear technology and workers, with 96 per cent of investment benefiting Ontario’s supply chain. It is a tremendous industrial advantage that Canada is among only six nations that own civilian nuclear technology, yet we stand alone as number one in building, operating, and refurbishing projects on-time and on-budget.”

The Darlington refurbishment project involved the complete overhaul of all four nuclear reactor units, extending the station’s operating life to at least 2055. With all four units refurbished and ready to be brought back online, this marks the completion of the world’s largest refurbishment project to-date, with the Darlington Nuclear Generating Station ready to deliver more than 3,500 megawatts (MW) of clean, reliable, emission-free electricity — enough to power 3.5 million homes — for at least 30 more years.

The Darlington refurbishment project was completed by over 6,000 Ontario workers, including skilled tradespeople, support services workers and project managers. Refurbishment work included replacing thousands of fuel channels, feeder tubes, calandria tubes, and end fittings, as well as rehabilitating other critical components. The project also included system improvements and plant upgrades to meet current regulatory requirements. During the construction phase, the project contributed an estimated $14.9 billion to Ontario’s GDP, with 96 per cent of project spending retained in the province. For every dollar invested, Ontario’s GDP increased by an average of $1.30, ensuring Ontario dollars continued to support local workers, families, and businesses at home.

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