Ontario Power Generation said it has begun an estimated $19 billion renovation project for four remaining active units at the Pickering nuclear power plant near Toronto that would extend the operation of its CANDU technology reactors by up to 38 years.
Pickering reactors 5, 6, 7 and 8 will be shut down on Sept. 30 in preparation for the overhaul, which is expected to take up to a decade to complete, the company said in previous statements, with major work starting early next year, starting with Unit 5, pending final approval from the Canadian Nuclear Safety Commission.
The plant, located on the north shore of Lake Ontario, about 20 miles northeast of Toronto, began operating in 1971, eventually growing to a total capacity of 3.1 GW. eight reactors. Units 1 to 4 ceased commercial operation in 2024 and are now being decommissioned and prepared for safe storage. Units 5 to 8, commissioned between 1983 and 1986, now operate at about 2.1 GW and supply about 14% of Ontario’s electricity. The upgrade will add 100 MW of capacity, Ontario Power Generation said.
The Pickering project, part of Ontario’s long-term Energy for Generations program to upgrade its nuclear fleet and invest in other energy infrastructure, will involve the replacement of 1,520 fuel lines and 48 boilers, as well as the construction of a 1.5 km deep water dam. The work also includes construction of a 200,000 square foot tube feeder and boiler replacement formation
“Since it began operations, Pickering Nuclear has established itself as one of the largest and best-performing nuclear facilities in the world,” said Nicolle Butcher, the utility’s president and CEO. The project would generate about 30,500 jobs annually during construction, the company said.
The provincial government described the new upgrade as a next-level energy independence move for Canada, following the completion in February of the $9.4 million renovation of four reactors totaling 3.5 GW at the Darlington plant, with work completed four months early and $110 million under budget. A similar upgrade of the 6.5 GW Bruce nuclear power plant is now underway, with an estimated $9.2 million effort due for completion in 2033.
“As President Trump continues to target Ontario’s economy, the government is taking action to secure Ontario’s energy future with the start of construction” in Pickering, the provincial government said in a statement. “The Pickering renovation is part of Ontario’s broader plan to expand nuclear generation and strengthen a tariff-proof, recession-proof and almost entirely Canadian-made industry.”
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Energy Minister Stephen Lecce added that “the best way Ontario can fight back … is to build big. Not only are we moving forward with this historic project, but we’re also awarding contracts that will keep more than 90% of the project costs in Ontario.”
The nuclear push continues Canada’s Prime Minister Mark Carney’s program to bolster overall domestic energy production, including oil and gas and renewables infrastructure, and to garner more global investment in these and other areas.
“We are unleashing our full potential as an energy superpower,” he said, addressing the inaugural Canada Investment Summit, held Sept. 14-15 in Toronto.
CLICK HERE to hear Mark Carney’s address.
Major Aecon and AtkinsRealis update
For the third time, Toronto-based Aecon Group Inc. and its partners, Montreal-based engineer AtkinsRéalis and Oakville, Ont.-based Siemens Energy Canada Ltd., are anchoring the nuclear plant upgrades, awarding a combined $2.13 billion in contracts to Pickering.
Awarded $1.24 billion for Unit 5, the first reactor to be upgraded, a 50/50 joint venture between Aecon and AtkinsRéalis won the three-year replacement, feeder and boiler contract that includes replacement of steam generators, fuel channels and feeders. Similar work is expected for units 6, 7 and 8 in later phases, the company said. The contract covers engineering and design services, project delivery and program and project management. Ian L. Edwards, chairman and chief executive of AtkinsRéalis, and Aecon chief executive Jean-Louis Servranckx said the companies’ respective portions of the contract will be added to their nuclear charters in third-quarter results.
Aecon and Siemens Energy also have a $922 million contract for the Pickering turbine generator replacement project. Aecon has the majority stake in both contracts and is responsible for construction services and procurement of materials.
Aaron Johnson, senior vice president of nuclear at Aecon, said the contractor is “applying the lessons learned, best practices and proven execution strategies of [the Darlington] He said Aecon is also leading the construction of what would be the first commercial grid-scale small modular reactor in a G7 country to operate at the Darlington site by 2030. Bruce Power has also proposed building four new large reactors at the site, totaling about 4,800 MW, which would be Canada’s first large nuclear in years longer than media reports.
canada it has also mandated that at least one nuclear plant, either a large-scale reactor or a small modular unit, must be in operation or under construction. orout of Ontario by 2035. Utilities in the territories of Saskatchewan, New Brunswick, Alberta and Yukon are now collaborating on projects or exploring technologies.
Nuclear blackout, risks of expansion
Meanwhile, officials such as Tim Hodgson, Canada’s natural resources minister, are weighing a plan, similar to that used in Britain, to win outside investors for nuclear power projects. Quebec-based public pension fund La Caisse announced last year that it had taken a stake in the $51 billion Sizewell C nuclear reactor project in England through a $2.26 billion investment.
But workforce challenges loom. A feasibility report on the Pickering project, obtained by CTV News in 2024, identified a lack of skilled workers in Ontario as a key vulnerability of the project, noting that “the availability of boilers, licensed asbestos insulators and [workers] Trevor Jones, Ontario’s Minister of Labour, Immigration, Training and Skills Development, noted that “by expanding access to apprenticeships and skills training, we’re building the workforce Ontario needs to deliver important projects like Pickering reform and support our continued growth.”
The expansion of nuclear power also presents challenges for Canada, including how to manage the long-term storage of nuclear waste and spent nuclear fuel, with that material now held at generation sites. However, the country is reportedly planning an underground site for permanent disposal.
With Pickering out of service for the next decade, there are also concerns about using other fuel sources to cover its power output, as the other provincial nuclear plants have little or no additional capacity to do so, the independent power system operator said.
As a result, Ontario has already begun ramping up contracting of natural gas generation. Four of the six major power generation contracts awarded by the system operator in recent procurement rounds were to natural gas plants, accounting for 90% of a 746 MW block, the Toronto Star said in 2025, raising concerns about higher carbon emissions.
The system operator also noted, however, that renewable energy and battery storage appear to be gaining favor for long-term procurement through 2034, actually undercutting the price of gas in some cases, a report in The Narwhal said. The 250 MW Oneida Energy Storage Project in Haldimand County, Ontario, which Aecon completed last year, doubled the province’s battery storage capacity to 475 MW, with a further 1.8 GW acquired from other projects expected to come online by 2028.
Still, there is speculation that a shortfall could still occur with Pickering out of service that could turn Ontario into a net energy importer for the first time since 2005, Narwhal said, with imports largely from the U.S. amid an ongoing trade war.
