The first North American-based small modular reactor (SMR) could take longer and cost more than earlier projected, Ontario Power Generation (OPG) reported this week.
The Canadian company reported in its third quarter earnings results that Unit 1 of the Darlington New Nuclear Project is no longer expected to be in commercial operation by October 2030, according to the company’s Tuesday press release.
OPG also said it does not expect to complete the first unit within the estimated budget of C$7.7 billion (US$5.4 billion).
OPG said this information comes from GE Vernova Hitachi’s ongoing engineering for this first-of-a-kind SMR project. GE Vernova’s BWRX-300 SMR, a boiling water reactor with a generating capacity of 300 megawatts, is being constructed at the Darlington site.
Assessment of the project cost and schedule could change further with completion of the engineering scope, OPG said.
According to the release, the assessment of the project cost and schedule is expected to be completed by mid-2027.
“We have made meaningful progress in building the G7’s first small modular reactor, and critical work continues every day on site,” OPG President and CEO Nicolle Butcher said in the release.
Butcher continued, “At the same time, we have identified risks that will impact Unit 1’s schedule and budget. As we continue construction, we are working to fully assess those impacts, and establish mitigation measures and a cost and schedule outlook that we can stand behind.”
The Darlington New Nuclear Project calls for four SMRs at the Darlington site to provide 1,200 megawatts of electricity for the Ontario Province. OPG received a construction permit from the Canadian Nuclear Safety Commission in April 2025 and began nuclear construction shortly afterward.
In October 2025, two Canadian government agencies committed C$3 billion (US$2.1 billion) to OPG’s Darlington project to help reduce the risk for the company’s construction and operation of its SMR units.
