Aecon celebrates the delivery of the Darlington Nuclear Refurbishment project with the final unit completed four months ahead of schedule

Aecon Group Inc. (TSX: ARE) (“Aecon”) was pleased to join Ontario Power Generation (“OPG”), the Government of Ontario, and its partner Candu Energy, an AtkinsRéalis company, to celebrate the delivery of the Darlington Nuclear Refurbishment project. Unit 4, the fourth and final unit on the project, has been successfully completed under budget and four months ahead of schedule.

“Aecon is immensely proud to have completed Unit 4, the fourth and final unit of this critical, decade-long project at OPG’s Darlington Nuclear Generating Station. Working alongside OPG and our project partners, the capability, discipline, and commitment of our Darlington team and Ontario’s skilled tradespeople drove unit-over-unit improvements in safety, schedule, and cost performance,” said Jean-Louis Servranckx, President and Chief Executive Officer, Aecon Group Inc.

Originally scheduled to return to service in August 2026, Unit 4 has now entered the testing phase, with first power expected in the first quarter of 2026. Darlington provides approximately 20% of Ontario’s electricity and will deliver more than 3,500 megawatts of clean, reliable emission-free electricity with all four units refurbished and back online – enough to power 3.5 million homes for at least 30 more years.

“Delivering the world’s largest nuclear refurbishment project safely and four months ahead of schedule provides a model for major nuclear projects on a global scale,” said Aaron Johnson, Senior Vice President, Nuclear, Aecon Group Inc. “This trailblazing project significantly contributed to the evolution of Ontario’s world-class nuclear supply chain and the growth of Ontario’s skilled workforce – providing lasting economic benefits.”

Since the project began in 2016, over 23 million hours of work was completed without a lost-time incident. Aecon has worked with OPG and its joint venture partner, Candu Energy, to apply lessons learned on each subsequent unit to achieve efficiencies and schedule savings. The team expertly replaced and rehabilitated thousands of components while leveraging an industry-first combined pressure tube and calandria tube removal process.

Quick facts

• 960 end fittings removed in each reactor

• 1,920 fuel channels installed in each reactor

• 3,840 feeder tubes removed and replaced across all four units

• 6,240 fuel bundles loaded into each reactor’s fuel channels

• 23 million hours of work executed without a lost-time incident

The refurbishment project and the subsequent 30 years of station operation are expected to generate a total of $90 billion in economic benefits for Ontario and create 14,200 jobs per year. With 96% of project costs spent in the province, for every $1 spent on the project, Ontario’s GDP is expected to increase by an average of $1.40.

Building on the success of the Darlington Refurbishment Project, Aecon and Candu Energy are also working to deliver the Pickering Nuclear Refurbishment project. Aecon-led partnerships are currently working on the Bruce Power Major Component Replacement Project and delivering North America’s first grid-scale Small Modular Reactor through the Darlington New Nuclear Project, along with a growing roster of projects across North America.

Learn more about the Darlington Refurbishment Project.

About Aecon

Aecon Group Inc. (TSX: ARE) is a North American construction and infrastructure development company with global experience. Aecon delivers integrated solutions to private and public-sector clients through its Construction segment in the Civil, Urban Transportation, Nuclear, Utility and Industrial sectors, and provides project development, financing, investment, management, and operations and maintenance services through its Concessions segment. Join our online community on X, LinkedIn, Facebook, and Instagram @AeconGroupInc.