Clarington: Darlington SMR to miss 2030 target and $7.7B budget, OPG says

Ontario Power Generation says the first small modular reactor being built at the Darlington Nuclear Generating Station in Clarington will not reach commercial operation by its October 2030 target or be completed within its previously disclosed $7.7-billion estimated cost. The company disclosed the change in its third-quarter financial results, released November 10, 2026.

The $7.7-billion figure includes systems and services shared with the other small modular reactors planned for the Darlington site. OPG said the delay reflects ongoing engineering by GE Vernova Hitachi Nuclear Energy on the first-of-a-kind BWRX-300 reactor, which has affected construction execution and supply chain performance. The company is working with the vendor to complete the outstanding engineering scope and move the project forward, it said.

The Darlington New Nuclear Project is building the G7's first small modular reactor, a 300-megawatt BWRX-300. OPG said the project has reached construction milestones including installation of the 2.1-million-pound basemat, assembly of the tunnel boring machine, and the first turbine building pour.

OPG said a comprehensive assessment of the project's cost and schedule is underway and is expected to be substantially complete by mid-2027. No revised in-service date or revised cost has been published. "We have made meaningful progress in building the G7's first small modular reactor, and critical work continues every day on site," said Nicolle Butcher, OPG's President and CEO. "At the same time, we have identified risks that will impact Unit 1's schedule and budget."

In the same release, OPG said it removed Pickering Nuclear Generating Station Units 5 to 8 from service in September 2026 in preparation for refurbishment. Preliminary work, including defuelling, is underway and is currently ahead of schedule, with refurbishment construction expected to begin in early 2027, pending approval from the Canadian Nuclear Safety Commission.