Canada’s Bruce Power has completed the construction phase of its Unit 3 Major Component Replacement (MCR) project, which remains on budget and ahead of schedule. The refurbished unit is expected to return to service later in 2026. Replacement of all eight steam generators was completed in February 2025, marking a major milestone in the MCR Project, which began in January 2020.
The eight pressurised heavy-water Candu reactor units at the Bruce site in Ontario (Bruce A – units 1-4, and Bruce B – units 4-8) began commercial operation between 1977 and 1987. Bruce Power’s CAD13bn ($10bn) Life Extension Programme, which includes Asset Management and MCR, began in 2016. MCR, which began with unit 6 and also includes units 3-8, will extend the life of the site until 2064.
Unit 6 was taken offline for the refurbishment in January 2020 and was returned to service in 2023. Units 1&2 have already been refurbished and were returned to service in 2012. Work began on unit 3 in March 2023. The unit 4 MCR outage began in February of 2025 and the unit 5 MCR is scheduled to begin in November. The Independent Electricity System Operator (IESO) will also study the possibility of a second refurbishment of units 1&2 in the future. Overlapping MCR outages will continue on the Bruce site until 2033.
Bruce Power Operations staff will begin refuelling the unit with 5,760 fuel bundles later in February, while other lead-out activities and regulatory inspections will be completed to enable reconnection to Ontario’s electricity grid.
Bruce Power and its construction partners including Shoreline Power Group (SPG), Steam Generator Replacement Team (SGRT), BWXT, ES Fox, ATS, Framatome, Kinectrics, Mammoet and many suppliers have worked together safely to successfully deliver this complex Project.
The construction phase of the unit 3 MCR, completed with SPG (a joint venture between Aecon, AtkinsRéalis and United Engineers & Constructors) and a multitude of tradespeople from the Ontario Building Trades, included the removal and replacement of 480 fuel channels and 960 end fittings, as well as the eight hulking steam generators. Steam generator work was completed by SGRT, a 50/50 joint venture between Aecon and SGT (a partnership between Framatome Canada Ltd. and United Canadian Operations Ltd).
“Bruce Power and Building Trades workers are securing the future of the province’s clean energy supply,” said Marc Arsenault, Business Manager and Secretary-Treasurer of the Provincial Building and Construction Trades Council of Ontario. “Together, we’re completing refurbishments safely, with quality, and on schedule, securing good jobs and helping to drive the economy.”
Bruce Power’s Life-Extension Program and MCR Project will extend the operational life of each reactor by 30 to 35 years helping to mitigate the predicted increase in greenhouse gas emissions from the electricity grid. Bruce Power’s MCR and Asset Management investments are closely co-ordinated with Project 2030, a programme that leverages innovation and new efficient technology to increase site capacity, targeting upwards of 7,000 MWe net peak output in the early-2030s, once all units have completed their MCRs. It will also ensure a steady supply of medical isotopes for the world market for decades to come.
“Unit 3’s Major Component Replacement is another powerful example of Ontario’s nuclear advantage in action,” said Stephen Lecce, Minister of Energy & Mines. “Ontario’s skilled trades and nuclear workforce delivered this milestone, strengthening our energy self-reliance. This investment powers 22,000 jobs, adds CAD4bn to our economy, and ensures clean, reliable electricity for decades – a made-in-Canada success story driving Ontario’s future.”
Eric Chassard, Bruce Power’s President and CEO noted: “Completing the construction phase of Unit 3’s Major Component Replacement is a major step forward for Ontario’s clean energy future. Thanks to the safe, high quality and disciplined work of our people, skilled trades and partners – and the innovative tooling that’s delivering step improvements in nuclear refurbishment performance – we’re now focused on returning this renewed unit to service on budget and ahead of schedule.”
Laurent Seigle, Bruce Power Executive Vice-President, Projects said: “Delivering strong performance on a project of this scale is the result of relentless focus on safety, disciplined execution, and the ability to innovate,” said “By applying lessons learned, investing in new tooling, and working as one team with our partners and skilled trades, we continue to raise the bar with each Major Component Replacement, improving schedule certainty, quality, and efficiency while setting the foundation for the units that follow.”
