Ontario Power Generation (OPG) has received Canada’s first-ever construction license for a grid-scale Small Modular Reactor (SMR). The approval pertains to Unit One of the Darlington New Nuclear Project (DNNP), a significant milestone for both Ontario and Canada.

Ontario Power Generation has completed the early works for the project, with the site transitioned into the care of the project’s construction partner, Aecon, to allow for main site preparation to begin. This work includes excavation, the construction of shoring walls, as well as land clearance for three additional units.

Ontario’s Minister of Energy and Mines, Stephen Lecce, hailed the approval as a historic step.

“This approval is a historic milestone for Ontario and Canada. The Darlington Small Modular Reactor will be the first of its kind in the G7, helping to power our growing province with reliable, affordable, and emissions-free energy,” Lecce said. “Ontario is realizing its potential as a stable democratic energy superpower, and I look forward to sharing next steps for this exciting project in the coming weeks.”

The Canadian Nuclear Safety Commission (CNSC) issued the power reactor construction license to OPG, authorizing the construction of a General Electric Hitachi BWRX-300 reactor at the Darlington site in Clarington. The license is valid until March 31, 2035, and includes four facility-specific conditions in addition to standard regulatory requirements to ensure effective oversight.

CNSC’s decision follows a review of public submissions, with a two-part hearing held virtually in October 2024 and in person in January 2025. The Commission concluded that OPG is qualified to construct the reactor in a manner that will safeguard public health and the environment.