Canada’s Bruce Power has started loading fuel into the unit 3 reactor at the Bruce NPP site in Ontario – a significant milestone in the unit’s Major Component Replacement (MCR) outage and a key step toward returning the unit to service.
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.
With fuel loading now underway, following approval from the Canadian Nuclear Safety Commission (CNSC), unit 3 is moving into the final phase of return‑to‑service activities following the successful completion of major refurbishment and construction work.
“Bruce Power is exceeding milestones and delivering refurbishments that further position Ontario as a global nuclear leader,” said Stephen Lecce, Ontario’s Minister of Energy and Mines. “This achievement reflects the strength of our skilled workforce and our commitment to delivering clean, reliable, made-in-Ontario nuclear power with over 90 per cent of every dollar staying in country.”
Fuel loading is being carried out following approval from the CNSC and under rigorous regulatory oversight. Bruce Power Operations staff will refuel the unit’s 480 fuel channels with 5,760 fuel bundles over the coming weeks, followed by system testing, inspections, and commissioning activities prior to reconnecting the unit to Ontario’s electricity grid. The team is leveraging lessons learned in unit 6 MCR outage to ensure high performance during the fuel load.
“Advancing the unit 3 MCR fuel load safely and efficiently to return the power plant to service on plan and with quality strengthens Ontario’s energy security by ensuring we can meet growing electricity demand with clean, affordable, dependable and made‑in‑Canada power,” said Eric Chassard, Bruce Power President & CEO. “Bruce Power and its amazing partners, supply chain and skilled workforce, as well as the entire nuclear industry, are completing projects to a high standard with disciplined delivery to power Ontario and its economy for decades into the future.”
