Bruce Power’s Unit 4 returned to service to play a key role in Ontario’s clean energy future

Bruce Power’s Unit 4 was returned to service Dec. 9 following a successful 98-day planned maintenance outage, which represented a $130 million investment in the life extension of the unit, helping to secure Ontario’s clean-energy future.

The outage, which began on Sept. 2, included fuel channel inspections to ensure the unit will operate safely until its planned Major Component Replacement (MCR) outage, beginning in 2025. Another planned inspection outage in Unit 4 is planned for May 2023.

During this outage, Unit 4 was the first of all eight Bruce Power reactor units to undergo an extensive turbine controls upgrade, a $90 million investment that will contribute to the unit’s reliable operation over the coming decades.

“The completion of the Unit 4 outage marks the end of a busy planned outage year,” said Mike Rencheck, Bruce Power’s President and Chief Executive Officer. “The maintenance, inspection and project work we are completing during our planned outages represents a huge investment into our units to extend their operating lives to secure a clean and reliable source of electricity for the people of Ontario for the long term. Our great employees, suppliers and building trades continue to perform these outages on plan.”

As part of the work during the outage and Bruce Power’s Project 2030, Unit 4 capacity is expected to increase by five megawatts (MW) to a new maximum output of 855 MW.

Project 2030 includes asset optimization, innovation and leveraging new and efficient technologies to achieve incremental upgrades and additional generation output from operating units. Bruce Power is targeting a site net peak capacity of about 7,000 MW for the 2030s in support of Ontario’s climate change targets and future clean energy needs.

Unit 4 was also shut down in May for the Bruce A Vacuum Building outage which saw all four operating units removed from service for planned inspections as per the requirements of the Canadian Nuclear Safety Commission. Vacuum buildings are unique to multi-unit CANDU generating stations and are part of their robust safety systems, providing an additional protective barrier to the release of radioactivity to the environment in the highly unlikely event of a nuclear emergency. All four operating units must be shut down once every 12 years to allow for inspections and maintenance to the vacuum building.

About Bruce Power

Bruce Power is an electricity company based in Bruce County, Ontario. We are powered by our people. Our 4,200 employees are the foundation of our accomplishments and are proud of the role they play in safely delivering clean, reliable nuclear power to families and businesses across the province and life-saving medical isotopes around the world. Bruce Power has worked hard to build strong roots in Ontario and is committed to protecting the environment and supporting the communities in which we live. Formed in 2001, Bruce Power is a Canadian-owned partnership of TC Energy, OMERS, the Power Workers’ Union and The Society of United Professionals. Learn more at and follow us on Facebook, Twitter, LinkedIn, Instagram and YouTube.