Ontario has completed the refurbishment of its last reactor at the Darlington Nuclear Generating Station, with provincial officials announcing that Unit 4 reached full power late Thursday night: nearly five months ahead of schedule and under budget.
The milestone marks the end of the multi-year overhaul of all four reactors at the facility, a project led by Ontario Power Generation and widely described by the province as the largest nuclear refurbishment project in the world.
According to the Ontario government, the return of Darlington Unit 4 to full output comes 142 days earlier than planned and $150 million below budget. The reactor had originally been scheduled to return to service on Aug. 2, 2026.