The Darlington Nuclear Generating Station has been granted a record-setting 20-year operating licence by the Canadian Nuclear Safety Commission (CNSC), the longest term ever awarded to a Canadian nuclear facility.
The decision, announced September 25, follows extensive public hearings earlier this year that included submissions from Ontario Power Generation (OPG), CNSC staff, and 79 intervenors. In its ruling, the commission concluded that OPG “remains qualified to carry on the activities that the renewed licence will authorize.”
Under the extension, Darlington’s licensed activities remain unchanged. However, the CNSC has required OPG to provide two comprehensive performance updates over the course of the licence term, as well as to continue its engagement with local First Nations throughout the period.
“This unprecedented 20-year licence is a strong vote of confidence in Darlington’s track record of safety and reliability,” said Nicolle Butcher, President and CEO of OPG. “It reflects the dedication of our highly skilled workers and our commitment to maintaining the highest standards of operational excellence. Under this licence, Darlington will continue delivering clean, reliable electricity to power Ontario’s future.”
Darlington, which consists of four CANDU reactors with a combined capacity of 3,512 megawatts, has undergone one of Canada’s largest energy infrastructure projects. Its multi-year refurbishment, launched in 2016, is expected to conclude in 2026 — ahead of schedule and on budget. The overhaul included replacing major reactor components, completing detailed inspections, and introducing upgrades to enhance safety and efficiency.
The CNSC emphasized its role as an independent regulator, overseeing nuclear facilities to ensure the protection of health, safety, security, and the environment, while fulfilling Canada’s international commitments on the peaceful use of nuclear energy.
Beyond the refurbishment, Darlington is also poised to play a pioneering role in the future of nuclear energy. OPG is constructing the first of four small modular reactors (SMRs) on the site, part of a separate licensing process. Once operational, the SMRs are expected to contribute significantly to Ontario’s transition toward a clean energy grid.
With this historic licence extension, Darlington will remain a cornerstone of Ontario’s electricity system for decades to come, supporting both reliability and the province’s climate goals.