Thursday, November 12, 2026
Ontario Power Generation (OPG) announced in its third quarter financial results that is is undertaking a comprehensive assessment of the Darlington New Nuclear Project (DNNP) cost and schedule, and indicated that the DNNP Unit 1 is no longer expected to achieve the previously disclosed commercial operation date target of October 2030 or be completed within the previously disclosed estimated cost of $7.7 billion, inclusive of required systems and services that would be common to all SMRs planned as part of the project.
As previously noted in OPG’s 2025 annual and 2026 second quarter Management’s Discussion and Analysis (MD&A), the DNNP is subject to inherent risks and uncertainties that could affect project cost and schedule.
This reflects GE Vernova Hitachi (GEVH) Nuclear Energy’s ongoing engineering for its first-of-a-kind SMR, which has impacts on construction execution and supply chain performance. OPG is working with GEVH to complete outstanding engineering scope and move the project forward as quickly as possible.
“We have made meaningful progress in building the G7’s first small modular reactor, and critical work continues every day on site,” said OPG president and CEO Nicolle Butcher. “At the same time, we have identified risks that will impact Unit 1’s schedule and budget. As we continue construction, we are working to fully assess those impacts, and establish mitigation measures and a cost and schedule outlook that we can stand behind. As work progresses, we will share the information transparently.”
The assessment of the project cost and schedule will be informed by the completion of engineering scope, including construction deliverables. The assessment will also include further evaluation of engineering design maturity and completion timelines, first of a kind design complexity impacts on construction and procurement assumptions, updated market conditions including inflationary and geopolitical risk, other residual risks, and the effectiveness of mitigation and recovery actions.
The assessment of the project cost and schedule is currently expected to be substantially completed by mid-2027. OPG intends to provide further updates as additional material information becomes available.
The Darlington New Nuclear Project is No. 2 on ReNew Canada’s Top100 Projects report.
OPG is continuing construction of the G7’s first small modular reactor (SMR) under the DNNP, and to date, the project has achieved important construction milestones, including installation of the 2.1-million-pound basemat – the first nuclear foundation laid in Canada in more than 30 years.
During the third quarter of 2026, the project completed assembly of the tunnel boring machine ahead of tunnelling activities expected to commence in the last quarter of 2026. The machine will bore and line the condenser cooling water tunnel, an essential element for bringing Canada’s first SMR online. The project also completed the first turbine building pour, marking a key milestone for the building foundation.
Featured image: (OPG)
