Ontario prepares to build three more small modular BWRX-300 reactors

The government of Ontario announced a partnership with Ontario Power Generation (OPG) to begin planning and licensing three more small modular reactors (SMRs) of the BWRX-300 design at the Darlington site. Once the power plant is fully completed, there will be a total of four SMRs at the site.

The announcement of plans to build three more BWRX-300 reactors follows January’s announcement of the construction of the first unit of this type at the Darlington site. The first demonstration unit is expected to be built at the site by 2028 at the latest, with the first electricity supplied to the grid in 2029.

The additional units could be commissioned between 2034 and 2036, depending on the flexibility of the Canadian nuclear regulator and the success of efforts to obtain a construction permit and licence.

With this timeline, OPG will be able to draw on experience gained from building the first unit. In theory, this should result in faster construction at lower cost. Building multiple small modular reactors also brings further savings through shared infrastructure. For example, the units can share water systems for cooling, power output systems and a unit control room, which can serve up to four units.

“Once these four units are operational, their total capacity will be 1200 MWe. At the Darlington site, this capacity can supply electricity to as many as 1.2 million homes. Together, we will help strengthen the province’s electricity security and economic growth,” OPG says.

At the end of October last year, OPG submitted an application to the Canadian Nuclear Safety Commission (CNSC) to build a BWRX-300 reactor at the Darlington site. This licence is required before construction work can begin. OPG is already preparing the site. OPG specialists believe that the CNSC will issue its decision on the reactor’s construction permit by the end of 2024.

BWRX-300

The BWRX-300 reactor system is a water-cooled boiling water reactor that uses natural circulation and passive safety systems. The unit meets the International Atomic Energy Agency’s (IAEA) definition of a small modular reactor (SMR). Its design is based on GE Hitachi’s ESBWR reactor.

In March, Canada’s nuclear regulator completed a pre-licensing vendor design review of the BWRX-300 with a positive outcome. The design is therefore the first to receive such an opinion.

Nuclear power is developing relatively rapidly in Canada. The government of Ontario announced the start of work to prepare for the construction of 4800 MWe of new nuclear capacity. The new units are the first major nuclear construction project in more than 30 years.

In addition to Canada, the United States is considering deploying the BWRX-300 reactor at the Clinch River site, as is Poland.