Bad News for Nuclear: A Landmark Reactor Just Got Delayed

Ontario Power Generation (OPG) announced in its third-quarter 2026 results that the first unit of the Darlington New Nuclear Project (DNNP) will not meet the previously disclosed commercial operation date of October 2030 or the estimated cost of CAD 7.7 billion (USD 5.4 billion), inclusive of common systems and services for the four planned SMRs. World Nuclear News reported that OPG attributed the delay and cost overrun to GE Vernova Hitachi (GEVH) Nuclear Energy's ongoing engineering for its first-of-a-kind BWRX-300 SMR, which has affected construction execution and supply chain performance. OPG said it is working with GEVH to complete outstanding engineering scope and move the project forward as quickly as possible. The company expects to substantially complete a comprehensive assessment of projected cost and schedule by mid-2027, informed by engineering design maturity, first-of-a-kind complexity impacts on construction and procurement, updated market conditions including inflationary and geopolitical risk, and the effectiveness of mitigation and recovery actions. OPG President and CEO Nicolle Butcher said the company has made meaningful progress building the G7's first small modular reactor and critical work continues on site, but identified risks will impact Unit 1's schedule and budget. GE Vernova Hitachi spokesperson Jonathan Allen was quoted by The Globe and Mail saying there are multiple interconnected contributions across engineering, procurement and construction, as well as evolving market conditions including inflation and geopolitical risks. The Darlington project will be the first new nuclear build in Ontario in more than three decades. OPG received a Licence to Construct the first of four planned BWRX-300s from the Canadian Nuclear Safety Commission in April 2025, and the Province of Ontario approved a CAD 20.9 billion (USD 15 billion) budget and the start of construction the following month. Ontario's Ministry of Energy and Mines said the plan would create up to 18,000 Canadian jobs and inject CAD 500 million annually into the Ontario economy, with the four units set to add CAD 38.5 billion to Canada's GDP over 65 years, and that 80% of project spending goes to companies in Ontario. Site preparation began in autumn 2022, several long-lead items including the reactor pressure vessel have been procured, and the giant Basemat module was set into place 35 metres below ground in the excavated reactor building shaft in April 2026. The BWRX-300 is a 300 MWe water-cooled, natural circulation SMR with passive safety systems leveraging the design and licensing basis of GE Vernova Hitachi's US NRC-certified ESBWR and its licensed GNF2 fuel design.