Ontario Construction News staff writer
CLARINGTON – The federal government has included Ontario Power Generation’s (OPG) Darlington Small Modular Reactor (SMR) as one of Canada’s major projects, the only Ontario initiative to appear on a list unveiled Thursday by Finance Minister Mark Carney.
The Canadian Nuclear Safety Commission issued a licence to construct the first SMR at Darlington in April, with the Ontario government granting approval for work to begin on May 8. OPG says site preparation has already been completed on time and on budget.
The Darlington SMR is set to be the first grid-scale SMR in North America. Through a six-year alliance agreement, OPG is partnering with Aecon, GE Vernova Hitachi Nuclear Energy (GVH) and AtkinsRéalis to deliver the project at the Darlington nuclear site east of Toronto.
The facility will use a GE Hitachi BWRX-300 reactor, a new class of nuclear technology capable of producing up to 300 megawatts of electricity — enough to power more than 300,000 homes. Developers say the design is intended to lower construction costs compared with conventional nuclear stations.
AtkinsRéalis is providing OPG with engineering expertise for the BWRX-300, including project management, licensing, design, procurement, construction support and commissioning, as well as digital delivery capabilities across both the nuclear island and balance-of-plant scopes. The company has been the project’s architect-engineer since 2023.
“As a world-class engineering services and nuclear organisation, we are advocates for the role of SMRs in the energy mix to create stable, affordable, and reliable power grids,” said Ian Edwards, president and CEO of AtkinsRéalis. He called the Darlington project “the first grid-scale SMR to be built in a G7 country – and Canada’s first nuclear new build in roughly 30 years.”
Aecon Kiewit Nuclear Partners was awarded the construction contract for the execution phase earlier this year, while GVH is responsible for reactor technology and major components. OPG holds the site licence and will maintain overall responsibility for commissioning, operator training, Indigenous engagement, stakeholder outreach and project oversight.
OPG president and CEO Nicolle Butcher added that the company will draw on its successful track record with AtkinsRéalis in the Darlington Refurbishment Project to deliver the new SMR.
The Darlington reactor is a key part of Ontario’s Critical Minerals and clean energy strategies, with officials positioning it as both a cornerstone of the province’s electrification push and a model for SMR deployment internationally. AtkinsRéalis says it is also supporting SMR projects in the U.K., U.S. and Poland.