Bruce Power's Unit 5 nuclear refurbishment approved for 2026 start

The Independent Electricity System Operator (IESO) of Ontario, Canada, has approved Bruce Power – the world’s largest operating nuclear facility – to begin its fourth Major Component Replacement (MCR) project, set to start on Unit 5 next year.

The decision followed after the crown corporation – which operates the province’s electricity market and manages the bulk power system – verified that the leading supplier of medical isotopes has met the terms and conditions to proceed with the project.

“As we stare down President Trump’s tariff threat, I am proud that well over 90 percent of all materials purchased are stamped with ‘Made in Canada,’ creating over 20,000 jobs for Ontario’s skilled workforce,” the province’s Minister of Energy and Mines, Stephen Lecce, says.

“That is why renewing Bruce Power’s Unit 5 MCR alongside nearly all of our nuclear fleets will enable us to secure more clean, reliable, and affordable electricity we need to power our homes and businesses for generations to come,” the minister continues.

Long-term clean energy

The MCR project will see the removal and installation of critical reactor parts, such as steam generators, pressure tubes, calandria tubes and feeder tubes, aimed to extend the reactor’s lifespan by 30 to 35 years.

Unit 5 will be the fourth of six reactors at the site to undergo refurbishment, following Unit 6, which was the first to be completed and returned to commercial service last September.

Meanwhile, Units 3 and 4 are currently undergoing their MCR outages, while Units 5, 7, and 8 are scheduled to follow in overlapping phases through 2033.

The project aims to provide clean, affordable electricity for Ontario and a stable supply of cancer-fighting medical isotopes worldwide.

“Ontario has become a world leader in nuclear power plant refurbishment and, along with our partners and skilled tradespeople, we continue to prove that these complex major projects can be delivered with the highest standards of safety and quality, on time and on budget,” Eric Chassard, Bruce Power president and CEO says.

“Through continued excellence and innovation, we’re helping to drive the economy and produce cancer-fighting medical isotopes,” Chassard continues. “Our nuclear industry is truly a made-in-Ontario and Canadian success story.”

Looking ahead

Lesley Gallinger, IESO president and CEO, emphasizes that the ongoing refurbishment of Bruce Power’s nuclear units supports the long-term reliability, affordability and sustainability of Ontario’s electricity system, while also making a significant contribution to the economic and social well-being of communities across the province.

IESO’s support for Bruce Power’s refurbishment program dates back to 2005, when the two parties signed an agreement enabling the return of Units 1 and 2 and the continued operation of the other units through price contracts. A revised agreement in 2015 backed life-extension investments for Units 3 to 8.

Bruce Power’s Life-Extension Program supports hundreds of local businesses with 90 percent of purchasing done in Canada. The projects generate $10 billion annually, boosting local economies and strengthening Canada’s energy independence. Additionally, the program offers long-term opportunities for Ontario’s construction and trades workforce, supporting 22,000 jobs across the province each year.

“The refurbishment of Bruce Power’s reactors is a vital step in securing a reliable, sustainable energy future and solidifying Ontario’s position as a global leader in clean energy,” Lisa Thompson, member of provincial parliament for Huron-Bruce concludes in a press release. “This project will drive long-term prosperity and ensures that Ontario continues to lead in both innovation and opportunity.”