As we’ve reported, OPG is planning to build a total of four SMRs at the Darlington nuclear site and would use GE Hitachi’s BWRX-300 reactor technology. The four units once deployed would produce a total 1,200 MW of electricity.

In its latest filings, the provincial utility said it completed early-phase site preparation work for the first SMR and site clearing activities for the three planned additional SMRs in March 2024. Now, the project has commenced main site preparation activities.

OPG said the project completed the tunnel boring machine launch shaft retaining wall for the condenser cooling water system in June 2024. The company has now begun to drill for the reactor building shaft retaining wall. OPG is also planning for the procurement of long-lead items such as the fabrication of the reactor pressure vessel (RPV).

In October 2022, OPG submitted the License to Construct application to the Canadian Nuclear Safety Commission (CNSC) for the first SMR. In April 2024, Canadian regulators announced that the existing environmental assessment for the project is applicable to the BWRX-300 technology. The CNSC will hold a two-part second public hearing in October 2024 and January 2025 to consider OPG’s application.

Darlington refurbishment update

OPG also provided updates on the Darlington Refurbishment project, which began in 2016 to extend the lives of the station’s four units by at least 30 years. Refurbishment of Unit 2 was completed in June 2020, with Unit 3 completed in July 2023.

Work on Unit 1 began February 2022. In April 2024, OPG completed the lower feeder installation series and the lower body supports installation series for the Unit 1 refurbishment, signaling the end of reassembly. The loading of new fuel into the reactor was completed in May 2024.

The project is currently working to restore the reactor vault, which includes removing the bulkheads to reconnect Unit 1 back to the operating units. Vault restoration is on track for completion in August 2024. OPG said this would represent the completion of construction work and transition of the unit to start-up activities.

OPG said Unit 1 is expected to be returned to service by late 2024, ahead of its original schedule set for the second quarter of 2025.

Unit 4 refurbishment activities are currently in disassembly. The removal of the fuel channel assemblies is expected finished in the third quarter of 2024 with the removal of pressure tubes and calandria tubes. Refurbishment of Unit 4 is scheduled to be complete by the end of 2026.

OPG said the refurbishments of Units 1 and 4 incorporate the learnings from Units 2 and 3. The utility said it continues to assess the impact of the COVID-19 pandemic on the project’s total cost, which is tracking toward its $12.8 billion budget.

In May 2024, OPG applied to renew the operating license for the Darlington GS for a period of 30 years beyond November 2025. The two-part public hearing is scheduled to be held by the CNSC in March 2025 and June 2025.

The provincial utility is planning to build a total of four SMRs at the Darlington nuclear site and would use  GE Hitachi’s BWRX-300 reactor technology. The four units once deployed would produce a total 1,200 MW of electricity.

In April 2024, the Canadian Nuclear Safety Commission (CNSC) announced that the existing environmental assessment (EA) for the Darlington New Nuclear Project (DNNP) is applicable to the BWRX‑300 reactor.

Meanwhile, OPG told regulators the project has transitioned into the next phase of site preparation, which includes excavation for the first SMR’s power block.

“The CNSC’s decision confirms OPG’s stance related to the EA and is a critical next step in OPG’s application for a [license] to construct the first of the four SMRs at the DNNP site,” said Ken Hartwick, OPG President and CEO.

OPG has said it expects construction on the first reactor to be complete by 2028, with the additional SMRs coming online between 2034 and 2036. The utility aims to take learnings from the construction of the first unit to deliver cost savings on the subsequent units.

“Our fleet approach to both early work and the project as a whole means we can leverage common infrastructure, such as shared roads, utilities, and water intake, which will help to drive down regulatory, construction, and operating costs,” added Hartwick.

Supporting new SMR development and investing in nuclear power is part of the provincial government’s larger plan to prepare for electricity demand in the 2030s and 2040s. Nuclear power currently provides about 50% of Ontario’s electricity supply.

Also at the site, OPG told regulators that its refurbishment project at the large nuclear plant at Darlington remains on plan. Unit 4, the final unit to undergo refurbishment at the Darlington Generating Station, is currently in the component removal phase.

On the plant’s Unit 1, the project completed the lower feeder installation series and the lower body supports installation series, signifying the end of the third major segment of the refurbishment, Reassembly, and the beginning of the final major segment, Power Up.

The provincial utilities announced a master services agreement at a press conference Nov. 20.

The five-year agreement, which builds on existing collaboration between the utilities, would help streamline SMR development in Saskatchewan. Under the agreement, LEP would focus on program management, licensing and operational readiness activities.

OPG aims to build North America’s first SMR at its Darlington New Nuclear site. OPG expects the first of four SMRs would be completed there by the end of 2028 and online by 2030.

“We’re a couple of years into our process with our technology, as well as ultimately building out an operational capability,” said OPG President and CEO Ken Hartwick. “And the goal of OPG and Laurentis is to build out all this capability [in Saskatchewan].”

OPG, SaskPower and Laurentis would also leverage the research and expertise of post-secondary institutions in both provinces. As part of the agreement, the companies would coordinate and enable industry suppliers in Ontario and Saskatchewan to support a Canadian fleet of SMRs.

Earlier in 2023, SaskPower and OPG renewed an agreement to continue working together on new nuclear development, including SMRs. The utilities would provide mutual support by sharing lessons learned, technical resources and expertise, best practices and operating experience. SaskPower and OPG would consider future collaboration in other areas, including project development and plant operations.

OPG and SaskPower have both selected the GE Hitachi BWRX-300 SMR for potential deployment.

The first of four SMRs will be completed by the end of 2028, and online by the end of 2029.

SaskPower has started looking at potential sites for the province’s first SMR. Deployment would be expected in the mid-2030’s. Saskatchewan plans to decide whether to proceed with the project in 2029.

Unit 3 becomes the second Darlington unit to be fully refurbished. Unit 2 was completed in early June 2020.  OPG aims to have all four units done by the end of 2026.

Refurbishment work on the four nuclear reactors at Canada’s second-largest nuclear station began in October 2016. The ten-year, C$12.8 billion ($9.37 billion) project is expected to enable Darlington to generate electricity for an additional 30-plus years.

Last September, OPG said the project had crossed the halfway point and was on track to be completed on schedule.

Unit 1 refurbishment is approximately 60 percent complete and is currently in the reassembly phase, the power utility said. Unit 1 is expected to be completed by mid-2025.

Unit 4, the last of Darlington’s four reactors, will come offline shortly to begin its refurbishment process.

Refurbishment involves replacing key components of the reactor, such as fuel channels, steam generators, pumps, and other critical equipment. This phase also includes defueling and refueling, testing and other maintenance activities.

The Darlington station is made up of four 878 MW CANDU reactors, which entered service between 1990 and mid-1993.

OPG already plans to develop the “first grid-scale SMR” in North America at the Darlington site, GE Hitachi’s BWRX-300 reactor. OPG is partnering with GEH, SNC-Lavalin and Aecon on the project, with construction expected complete by 2028.

Subject to Canadian Nuclear Safety Commission (CNSC) regulatory approvals, the additional SMRs could come online between 2034 and 2036. The provincial government said OPG could take learnings from the construction of the first unit to deliver cost savings on the subsequent units.

Building multiple units would also allow common infrastructure such as cooling water intake, transmission connection and control room to be utilized by all four units instead of just one.

The four units once deployed would produce a total 1,200 MW of electricity.

Supporting new SMR development and investing in nuclear power is part of the government’s larger plan to prepare for electricity demand in the 2030s and 2040s. Nuclear power currently provides about 50% of Ontario’s electricity supply.

“A fleet of SMRs at the Darlington New Nuclear Site is key to meeting growing electricity demands and net zero goals,” said Ken Hartwick, OPG President and CEO.

The letter of intent signed by the companies June 2 builds on the companies’ existing relationship.

OPG and OSGE, along with the Tennessee Valley Authority (TVA), signed a technical collaboration agreement in March aimed at speeding up the regulatory process and deployment of GE Hitachi’s BWRX-300 SMR. That collaboration agreement would ensure the standard design is deployable in the U.S., Canada, Poland and beyond.

WATCH: GE Hitachi executive Sean Sexstone recently spoke exclusively with Power Engineering about the path to commercialization for the BWRX-300.

The agreement just signed by OPG and OSGE is aimed at future opportunities, under which OPG and its subsidiary, Laurentis Energy Partners, could provide SMR operator services to OSGE as they deploy SMRs in Poland and elsewhere in Europe. The partnership would include a number of SMR-related activities, including development and deployment, operations and maintenance, operator training, commissioning and regulatory support.

OSGE plans to deploy a fleet of BWRX-300 SMRs in Poland, with the first unit ready before the end of this decade. OSGE has applied to the Polish Government for a Decision in Principle on six potential sites and is now working through the regulatory process.

Site preparation for the first BWRX-300 is now underway at OPG’s Darlington New Nuclear Project Site, with construction to be completed in 2028. This could become the first grid-scale SMR to be built in North America.

GE Hitachi (GEH) has hopes for its BWRX-300, the 10th evolution of GE’s boiling water reactor design. The 300 MW water-cooled reactor design is based on the company’s Economic Simplified Boiling-Water Reactor (ESBWR), which is already licensed by the U.S. Nuclear Regulatory Commission.

GEH Executive Vice President of Advanced Nuclear Sean Sexstone refers to the BWRX-300 as a “simply made reactor” because it uses the same equipment and fuel that are already in GE reactors around the world.

“Ninety-five percent of it has been done,” said Sexstone in an exclusive interview with Power Engineering. “Maybe these are a little smaller in scale, but very proven.”

This is one reason why GE Hitachi believes the BWRX-300 can become the cheapest, quickest and lowest-risk SMR to market.

Sexstone said the company took the basic ESBWR design and simplified it, including several design safety features which are new to boiling water reactor technology.

The safety relief valves, deemed the most likely cause of a loss of coolant accident (LOCA), were eliminated in the design. The isolation condenser system (ICS) provides overpressure protection in accordance with ASME BPV code, section III, class 1 equipment (Status Report – BWRX-300 – GE Hitachi and Hitachi GE Nuclear Energy). In order to accommodate this change, the design pressure has been raised by 20% from previous boiling water reactors. GE Hitachi has also implemented integral isolation valves, which close to stop the loss of coolant in an accident scenario.

In general, because of their relatively small physical footprints, reduced capital investment and more flexible siting, SMRs are viewed as an antidote to the cost overruns that have plagued large-scale nuclear projects.

Sexstone said GE Hitachi has been able to eliminate roughly 90% of the concrete and steel from the ESBWR, leaving a total power plant footprint smaller than a football field. The company projects the BWRX-300 to have up to a 60% lower capital cost per megawatt compared with the typical water-cooled SMR.

But despite policy support and market growth for new nuclear, the economics are daunting.

First of a kind (FOAK) SMR costs could be as high as $8,000 per kilowatt (kW) and as low as $6,000 per kW, according to industry estimates cited by Wood Mackenzie. Analysts there expect that FOAK costs will be at the high end of this range, and could be even higher, as developers build out early-stage projects.

Sexstone told Power Engineering supply chain partnerships will be crucial to success.

“If we’re going to build two, three hundred or more of these [BWRX-300s], I think it’s going to be crucial that we have really good partnerships and we’re able to grow the supply chain in Canada, in the U.S., and globally,” he said.

In March 2023 the company announced a technical collaboration agreement with Ontario Power Generation (OPG), Tennessee Valley Authority (TVA) and Synthos Green Energy (SGE) aimed at speeding up the regulatory process and deployment.

Through the agreement, the partners will invest a total of around $400 million in the development of the BWRX-300 standard design and detailed design for key components, including reactor pressure vessel and internals. The collaborators are forming a Design Center Working Group with the purpose of ensuring the standard design is deployable in the U.S., Canada, Poland and beyond.

“The goal is, once that standard is set, it doesn’t change,” said Sexstone. “Then we can work on driving down the cost curve as we deploy multiple reactors.”

He added: “We have to get this first one or two right.”

OPG aims to deploy the BWRX-300 at its Darlington New Nuclear Project site in Clarington, Ontario. A commercial contract between GE Hitachi, Ontario Power Generation, SNC-Lavalin and Aecon was inked in January 2023. In 2022 the Canada Infrastructure Bank committed C$970 million ($713 million) toward the project in the bank’s largest investment in clean power to date.

This would be the first grid-scale SMR in North America. Site preparation is currently underway, with GE-Hitachi expecting approval to begin construction by late-2024. The reactor could be built by late-2028 or early-2029.

“We’re getting the site ready, finalizing both standard and site-specific design, ordering long lead engineering equipment important to maintaining the construction schedule,” Sexstone said.

In August 2022, TVA began planning and preliminary licensing for potential deployment of the BWRX-300 at its Clinch River Site near Oak Ridge, Tennessee. In June 2022 SaskPower announced that it had selected the BWRX-300 for potential deployment in Saskatchewan in the mid-2030s.

GE Hitachi, NuScale and Holtec are among the companies developing water-cooled SMRs. Other advanced reactor technology under development includes the use of nontraditional coolants such as liquid metals, salts and gases.

“We’ve got all these projects starting and funded by the government and private industry to develop new designs,” said Doug True, who is chief nuclear officer of the Nuclear Energy Institute (NEI). “It’s just a really exciting time to be in the industry.”

Another boost came from the federal Inflation Reduction Act (IRA), which offers a generous tax credit for advanced nuclear reactors and microreactors.

This has helped SMRs become even more attractive to utilities. True said NEI surveyed Chief Nuclear Officers at U.S. utilities in 2022, asking how much advanced nuclear they would need to meet decarbonization goals. He said the cumulative response was greater than 90 GW.

NEI updated the survey following the IRA’s passage and saw about a 10% increase, with personnel saying they’d need about 100 GW in new nuclear.

For another perspective, recent assessments cited in the Electric Power Reserarch Institute (EPRI) Advanced Reactor Roadmap suggest that over the next 10-20 years, the need to deploy advanced reactors in the United States and Canada will rival, and likely exceed, the scale of the entire existing operating nuclear energy capacity in North America.

“There are going to be challenges,” said True. “But the way that other countries have gotten their costs down for nuclear [reactors] is by getting good at building them. These first plants will get there, and we’ll learn, and we’ll get better and better.”

Wood Mackenzie’s modeling shows that if costs fall to $120/MWh by 2030, SMRs will be competitive with nuclear pressurized water reactors (PWRs), gas and coal – both abated and unabated – in some regions of the world.

Site preparation work – including non-nuclear infrastructure activities, such as clearing and grading parts of the site to build roads, utilities and support buildings – began in October and is planned to extend into 2025.

The license application was filed with the Canadian Nuclear Safety Commission (CNSC) on October 31 and was developed between OPG and GE Hitachi, which designed the BWRX-300. 

The regulatory review process includes opportunities for Indigenous Nations and Communities and the public to discuss the application, ask questions and raise areas of interest, OPG said, culminating in a public hearing, held by the CNSC. That is likely to take place in 2024.

The Darlington site is currently the only site in Canada licensed for a new nuclear build, with an accepted environmental assessment and site preparation license. OPG said it expects to make a construction decision by the end of 2024. It set a preliminary target date of 2028 for plant operations.

The BWRX-300 is a 300 MWe water-cooled, natural circulation SMR with passive safety systems that leverages the design and licensing basis of GEH’s ESBWR boiling water reactor. It is currently undergoing a CNSC pre-licensing Vendor Design Review.

If built, the Darlington SMR would be one of the first developed and could spark similar projects in Saskatchewan, New Brunswick and Alberta, with interest also emerging in the U.S. and Europe.

The Canada Infrastructure Bank recently committed C$970 million ($713 million) toward the Darlington New Nuclear Project in the bank’s largest investment in clean power to date, providing greater financial certainty and signaling federal support for the project.

Refurbishment work on the four nuclear reactors at Canada’s second-largest nuclear station began in October 2016. 

The Unit 3 project team is working through reactor reassembly, and the unit’s refurbishment work is more than 75% complete. Fuel channel installation was completed in mid-July, requiring the installation of 480 calandria and pressure tubes, 960 end fittings and other components. With fuel channels installed, lower feeder installation is underway, OPG said. 

Project teams used lessons learned from Unit 2, which, in 2020, was the first Darlington reactor to be refurbished, to trim time off of the schedule for Unit 3 retube and feeder replacement work.

Fuel reloading is expected to take place later this year and the unit is slated to return to service by mid-2023.

Work to defuel Unit 1 began last spring as the unit began its own 39-month refurbishment. Fuel removal involved using remote-controlled tooling to remove 6,240 fuel bundles from the reactor. Bulkheads were installed to island Unit 1 from the other operating units. OPG and its project partner, CanAtom Power Group, are reportedly preparing the reactor vault for the disassembly phase.

The final unit to be refurbished–Unit 4–is slated to start work in the third quarter of 2023. It has an expected return-to-service date in the fourth quarter of 2026.

The C$12.8 billion ($9.37 billion) project is expected to enable Darlington to generate electricity for an additional 30-plus years.

The Darlington station is made up of four, 878 MW CANDU reactors, which entered service between 1990 and mid-1993.

In October 2021, nuclear equipment firm BWXT’s Canadian subsidiary partnered with GE Hitachi Nuclear Energy on an engineering and procurement deal to support design and manufacturing of a small modular nuclear reactor at the Darlington station. The agreement aimed to facilitate development work on the BWRX-300 SMR, a 300-MW water-cooled reactor that is an evolution of the boiling water reactor design.

The Xe-100 is a high-temperature gas-cooled reactor that is designed to combine high-temperature steam and power production. The two said the reactor can support heavy industry including oil sands operations, mining applications, and other industrial processes.

One unit can generate up to 80 MW of electricity from 200 MW of thermal power, and can produce steam at 565 Celsius. The partners said it offers flexible co-generation options.

A press release said that Natural Resources Canada’s (NRCan) SMR Action plan shows an estimated global value of C$150 billion ($115.4 billion) per year by 2040 by replacing coal-fired generation; by providing heat and power for mines; by providing steam for heavy industry; and for remote island nations and off-grid communities.

Last November, OPG said it would work with GE Hitachi Nuclear Energy to deploy a BWRX-300 SMR at the Darlington new nuclear site, the only site in Canada currently licensed for a new nuclear construction, to be completed by the end of the decade.   

In 2020 the U.S. Department of Energy named X-energy as an awardee for its Advanced Reactor Demonstration Program (ARDP), which provides initial funding to build two advanced nuclear reactors that can be operational before the end of the decade. 

The Xe-100 is an 80 MWe (scalable to a 320 MWe four-pack) high temperature gas-cooled reactor. It uses TRi-structural ISOtropic particle fuel (TRISO), manufactured by Rockville, Maryland-based X-energy, that can integrate into large, regional electricity systems as a base and load-following source of low-carbon power. 

Earlier this year, TRISO-X LLC, a unit of X-energy, chose a site in Oak Ridge, Tennessee for its commercial advanced nuclear reactor fuel fabrication facility, one of the nation’s first High-Assay Low-Enriched Uranium (HALEU) based fuel fabrication facilities.