The Canadian Nuclear Safety Commission (CNSC) has granted Ontario Power Generation (OPG) approval to build a BWRX-300 reactor at the Darlington New Nuclear Project site in Clarington, Ontario. The CNSC determined that OPG is capable of performing the licensed activities, has robust programs to safeguard workers, the public, and the environment, and will uphold national security and Canada’s international commitments.

A rendering of a BWRX-300 plant

Valid until March 31, 2035, the license includes specific conditions and regulatory checkpoints during construction, requiring OPG to submit additional details to the CNSC before advancing further. This approval covers only the construction phase, not the reactor’s operation, which would require a separate licensing process if OPG applies for it in the future. OPG first sought a site preparation license in September 2006, with the CNSC completing an environmental assessment in May 2007. In 2012, the Canadian government concluded that the project is unlikely to cause significant environmental harm.

In December 2021, OPG chose the GE Hitachi BWRX-300 reactor for the site and applied for the construction license in October 2022. OPG shared on social media platform X: “The decision to grant OPG a license to construct the first of 4 SMRs is a significant milestone. We now await the go-ahead from the Ontario government to proceed.” Early site preparation is complete, with construction expected to begin later in 2025, pending final approvals, and operations targeted for late 2029.

Ontario’s Minister of Energy and Mines, Stephen Lecce, responded: “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.” He noted the project could generate up to 17,000 jobs during construction, add over CAD15 billion (USD10.5 billion) to Canada’s economy, and contribute CAD500 million annually to the supply chain, emphasizing the use of local and Canadian businesses.

In January 2025, GE Hitachi announced a contract with BWX Technologies to produce the reactor pressure vessel for the first Darlington small modular reactor (SMR). The project aligns with efforts to deliver clean, dependable energy while boosting economic growth through local industry involvement. It positions Ontario as a leader in innovative energy solutions, with plans for up to four SMRs at the site to meet rising electricity demands sustainably.