A total of four BWRX-300 SMRs are now planned for deployment at Darlington, located about 45 miles east of Toronto. In January of this year, Wilmington, N.C.–based GEH, along with OPG and fellow Canadian firms SNC-Lavalin and Aecon, announced the signing of a contract for the deployment of a single BWRX-300 at the site. Construction of that unit is expected to be completed by the fourth quarter of 2028.
Subject to regulatory approvals on construction from the Ontario government and the Canadian Nuclear Safety Commission (CNSC), the additional SMRs could come on line between 2034 and 2036, according to last week’s announcement. This timing would allow OPG to apply lessons learned from the construction of the first unit to deliver cost savings on subsequent units, the government stated, adding that building multiple reactors would also allow common infrastructure to be utilized by all four units instead of just one, further reducing costs.
Renaissance men: “Our government’s open-for-business approach has led to unprecedented investments across the province—from electric vehicles and battery manufacturing to critical minerals to green steel,” declared Todd Smith, Ontario’s minister of energy. “Expanding Ontario’s world-leading SMR program will ensure we have the reliable, affordable, and clean electricity we need to power the next major international investment, the new homes we are building and industries as they grow and electrify.”
Ken Hartwick, OPG president and chief executive officer, said that his company “has proven its large nuclear project expertise through the on-time, on-budget Darlington refurbishment project” and that “by taking a similar approach to building a fleet of SMRs, we will deliver cost and schedule savings, and power 1.2 million homes from this [new nuclear] site by the mid-2030s.”
GEH president and CEO Jay Wileman added, “OPG and the province of Ontario have staked a leading position in the deployment of new nuclear with a project that will offer significant energy and economic benefits to Ontario and Canada. . . . We look forward to working closely with the SMR project partners as we build a fleet of new reactors together and demonstrate nuclear project excellence here in Canada.”
The tech: An evolution of GEH’s 1,520-MWe Generation III+ ESBWR design (approved by the Nuclear Regulatory Commission in 2014), the BWRX-300 is a 300-MWe water-cooled, natural-circulation SMR with passive safety systems. According to the company, because of design simplification, the BWRX-300 should require significantly lower capital costs per megawatt than other water-cooled SMR designs or existing large nuclear reactor designs. In March, the CNSC completed a combined phases 1 and 2 vendor design review of the unit, finding no fundamental barriers to licensing.
Background: Darlington, home to four 878-MWe CANDU pressurized water reactors, is the only site in Canada currently licensed for new nuclear. OPG was granted a license by the CNSC in 2012 to allow site preparation activities for a nuclear new-build project. The license was renewed in October 2021, and is now valid until October 11, 2031.
In October 2020, OPG announced that it was working with three grid-scale SMR technology developers—GEH, Terrestrial Energy, and X-energy—to advance engineering and design work with the goal of identifying options for future deployment. The following month, the utility announced the resumption of planning activities for future nuclear power generation at Darlington, with the goal of hosting a grid-size SMR as soon as 2028. (An earlier project plan had focused on the construction of traditional large reactors.) OPG selected GEH in December 2021 as its technology partner for the SMR project.
