OPG planning up to four units at Darlington nuclear site.

Canada’s nuclear regulator has said the existing environmental assessment for new nuclear at the Darlington station in Ontario is applicable to the General Electric Hitachi BWRX‑300 reactor technology chosen by Ontario Power Generation (OPG) for the site.

OPG is planning to build up to four new nuclear reactors at the existing Darlington nuclear site in the municipality of Clarington.

In October 2022, OPG applied to the Canadian Nuclear Safety Commission (CNSC) for a licence to construct. Before it could consider OPG’s application, the commission was required to determine whether the chosen technology was fundamentally different from the technologies assessed in the environmental assessment, and whether a new assessment was needed.

“It is important to note that this decision does not authorise the construction of a BWRX‑300 reactor,” CNSC said. “The commission will hold a future public hearing to consider OPG’s application for a licence to construct one BWRX‑300 reactor at the Darlington nuclear site.”

In March, OPG said the early works phase of site preparation had been completed at the Darlington SMR site, where the first grid-scale SMR could go online by 2028.

The work at the Darlington, already home to four large-scale Candu 850 heavy water reactor units owned and operated by OPG, involved civil works including site grading, construction of temporary roads and construction laydown areas, installation of stormwater features, and establishment of onsite power water and IT infrastructure.