New Canadian record: Darlington nuclear power plant extends licence until 2045

Canada’s nuclear regulator has announced that Darlington nuclear power plant can continue operating until 2045. Its licence has been extended by twenty years, making Darlington the plant with the longest operating licence in the country.

The Canadian Nuclear Safety Commission (CNSC) issued its decision after reviewing the application from the operator, Ontario Power Generation (OPG), submissions from the commission’s staff and comments from 79 intervenors. The commission said OPG remains qualified to operate the plant safely in accordance with the requirements of the new licence.

The new licence does not change the scope of OPG’s activities, but sets several new conditions. These include a requirement to submit two comprehensive assessments of the plant’s performance and to maintain active dialogue and cooperation with local communities throughout the licence period.

The importance of refurbishing Candu reactors

Candu reactors are pressurised heavy-water reactors with an original design life of usually 30 years. Refurbishment, or a major overhaul of a reactor unit, involves replacing key components such as steam generators, pressure and calandria tubes, and feedwater piping. Before this work begins, all fuel and heavy water must be removed from the reactor, which must be completely disconnected from the rest of the plant.

Thousands of components are then inspected, and the reactor is reassembled so that it can operate safely for another 30 years.

Status of the Darlington project

Of the plant’s four units, three have already been successfully refurbished and returned to service. The fourth unit is expected to be connected to the grid in 2026, completing the plant’s decade-long refurbishment programme. According to OPG, the project has achieved better-than-expected results in safety, quality, schedule and cost.

Significance for Canada’s energy sector

OPG President and CEO Nicolle Butcher said that securing the longest licence for a Canadian nuclear power plant confirms the facility’s top performance and the high level of expertise of its staff. The plant’s current licence expires on 30 November this year.

“Darlington will continue to safely and reliably supply electricity to meet Ontario’s needs for many decades under this licence,” Butcher said.