Bruce Power has successfully completed the defueling of Unit 4’s Major Component Replacement (MCR) outage ahead of schedule, marking a significant achievement in its Life-Extension Program.
The milestone was reached on February 25, setting a new efficiency record for CANDU reactors and reinforcing the company’s commitment to innovation and continuous improvement.
According to a media release from Bruce Power, the defueling process—removing 5,761 fuel bundles—was completed in just 24 days, making it the fastest defuel in the history of CANDU reactors. This surpasses Bruce Power’s previous records for Unit 6 (46 days) and Unit 3 (29 days).
"We continue to improve our performance in each successive MCR outage with our skilled workforce leveraging innovation and lessons learned," said Bruce A Plant Manager Lucas Van Wieringen. He credited the success to state-of-the-art modifications, workforce proficiency, and a well-planned schedule that ensured efficiency and safety.
Now that defueling is complete, the next major milestone for Unit 4 is the chemical decontamination of its Primary Heat Transport (PHT) system. This step, which was successfully introduced during the Unit 3 MCR, significantly reduces radiation dose rates and enhances safety before major construction begins. The innovative decontamination process has been recognized as a technical breakthrough and is expected to yield excellent results once again.
Following the chemical decontamination, major component disassembly will begin, with the renewed Unit 4 scheduled to be reloaded with fuel ahead of its 2027 restart.
Bruce Power’s Life-Extension Program is a massive undertaking aimed at extending the operational lives of Units 3-8 until 2064. With both Unit 3 and Unit 4 refurbishments underway simultaneously, Bruce Power is executing overlapping MCR outages until 2033, an achievement unmatched by any other utility worldwide.
By ensuring these nuclear units continue operating for decades, Bruce Power remains a key supplier of reliable electricity for Ontario, supporting the province’s energy security and environmental goals.
