Quick answer
Pickering units 1 and 4 retired in 2024. Units 5 to 8 came offline in September 2026 ahead of a $26.8 billion refurbishment that begins in 2027 and runs to the mid-2030s, securing about 2,100 MW for another 30-plus years.12
Timeline
- 2024: units 1 and 4 retire.1
- September 2026: units 5 to 8 are taken offline.2
- Early 2027: refurbishment is set to begin, starting with Unit 5, pending approval.2
- Mid-2030s: refurbishment expected to be complete.2
Why refurbish instead of close
The refurbishment is planned to secure 2,100 MW of low-carbon electricity for another 30-plus years to help meet Ontario's growing demand.2 OPG is also building a large training and mock-up facility to prepare more than 2,800 skilled trades workers.2
What it means for supply
While reactors are offline, they don't produce power. In 2019, as Pickering's closure approached, OPG bought gas plants with nearly 2,700 MW of capacity.3
Common follow-up questions
How much of Ontario's power did Pickering supply?
In 2019 OPG said Pickering accounted for approximately 14% of Ontario's electricity needs.
Are other nuclear plants being rebuilt?
Yes. Darlington's refurbishment finished in early 2026, and Bruce Power is replacing major components on six units.
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Answers are general information as reported by the sources listed on the date shown, not personal financial or technical advice. Programs, prices and rules change. Canadian Energy Standard is an independent company, not affiliated with any government, utility or program named here.
- Ontario Power Generation, Pickering Nuclear Generating Station
- insauga, $26.8 billion nuclear refurbishment to begin in Pickering early next year (August 2026)
- Financial Post, OPG's gas-plant purchases partly prompted by shifting nuclear landscape (August 2019)