Ontario Power Generation completes nuclear refurbishment four months ahead of schedule

Ontario Power Generation is celebrating a milestone a decade in the making this week after Unit 4 at the Darlington nuclear plant was reconnected to the grid – the first time the unit has been supplying power to Ontario residents since it was taken offline for refurbishment in July 2023 and the completion of a project that began in 2016.

Unit 4’s refurbishment wrapped up in 968 days, making it the first Darlington unit to be completed in under 1,000 days, a culmination of “meticulous planning and preparation, millions of hours worked, and the dedication of thousands of people,” said OPG CEO Nicholle Butcher.

“We give our thanks to all who made the Darlington Refurbishment a resounding success – from our employees to our project partners to the province’s robust nuclear supply chain. They have helped set the standard and now we’re ready to keep delivering for Ontario’s future.”

The completion of work on Unit 4 completes Darlington’s four-unit refurbishment, which began in the fall of 2016. The project came in four months ahead of schedule and $150 million under budget.

The renewed station is now set to power Ontario for more than 30 years, while giving OPG’s skilled workers some “8,000 lessons learned” they can use on other projects, such as the refurbishment of Pickering nuclear, the construction of four small modular reactors at Darlington the proposed large-scale CANDU reactor in Wesleyville, just east of Darlington.

“Through this project, we have demonstrated to the world that complex nuclear projects can be completed successfully, ahead of schedule and under budget,” said Butcher. “Our experience on this refurbishment, and the thousands of lessons we have learned, will serve as our foundation as we advance the future of nuclear.”

“Darlington’s refurbishment has given us the confidence, the tools, and the skills to forge ahead.”

Clarington Mayor Adrian Foster was effusive in his praise for the refurbishment, calling it an “extraordinary milestone.”

“Completing the final phase of refurbishment nearly five months early is a remarkable accomplishment, and one that speaks volumes about the skill and dedication of the people behind it,” he said. “Projects of this scale succeed because thousands of individuals bring their best every day. From trades and technical teams to engineers, planners, and Canadian suppliers, the workforce behind Darlington has demonstrated what our community has long known: when the eyes of the world are on Clarington, we deliver. Their effort has helped complete the world’s largest nuclear refurbishment – an achievement that will strengthen our province’s power system for decades.”

Darlington nuclear produces more than 3,500 megawatts of electricity, enough to power 3.5 million homes.