Ontario's $20.9B Nuclear Project Faces Cost and Uranium Sourcing Criticism

This story is part of a selection of our top news from 2025 that we're republishing during the holiday break. We'll be back to our regular schedule in the new year.

Ontario's decision to introduce small modular nuclear reactors (SMRs) at Darlington has sparked significant debate, focusing mainly on project costs and the risks of depending on enriched uranium from the U.S.

Ontario Power Generation announced approval of the first of four SMRs on May 8, marking the first new nuclear project in the province in over 30 years.

"This is truly a historic moment," said OPG President and CEO Nicolle Butcher. "This made-in-Ontario project will support provincial companies, create jobs for Ontarians, and spur growth for our economy."

Energy and Mines Minister Stephen Lecce announced the 1,200-megawatt project as a "nation-building" initiative, while Durham MPP Todd McCarthy emphasized its potential to bolster Ontario and Canada's energy security.

The first reactor's cost stands at $7.7 billion, with infrastructure and administrative expenses amounting to $1.6 billion, and $20.9 billion for the entire set of four. According to OPG, citing Conference Board of Canada data, the SMRs will contribute $38.5 billion to Canada's GDP over 65 years, creating 3,700 jobs annually, including 18,000 per year during construction.

First Mover Advantage or Boutique Pricing?

Butcher noted that being the first G7 region to adopt SMRs could offer Ontario a chance to showcase its nuclear expertise globally. However, The Globe and Mail highlights that the project's cost surpasses expectations, with independent observers suggesting it may deter additional investments.

Ed Lyman from the Union of Concerned Scientists described the estimate as "eye-popping" yet anticipated, pointing to the challenging economics of SMRs. He suggested that the Darlington SMR could become "a boutique unit" with high electricity costs.

According to an Ontario Clean Air Alliance study released last week, Darlington's SMRs will be substantially more expensive than renewable alternatives, such as wind and solar energy. Energy Futures Group used data from Ontario's Independent Electricity System Operator to compare nuclear with renewable power options.

The report projects the levelized cost of electricity (LCOE) by 2030 and 2040, with and without the federal clean energy investment tax credit. By 2040, unsubsidized costs are expected at:

• $30 for onshore wind;

• $41 for utility-scale solar;

• Up to $269 for SMRs and $307 for conventional nuclear, while a 30% ITC might lower SMR costs to $137 per MWh.

York University's Mark Winfield questions the financial feasibility, mentioning potential rate increases for Ontario electricity consumers and challenging the categorization of nuclear as 'clean' energy.

Concerns linger over whether operational experience with the four SMRs will sufficiently reduce costs for remaining units, already projected to range from $4.1 to $4.9 billion each. New Brunswick's scaling back of SMR plans adds further uncertainty.

Uranium Sourced from the United States

With the BWRX-300 relying on enriched uranium from New Mexico, geopolitical tensions raise concerns over supply reliability. After tariffs imposed by the U.S., Ontario Premier Doug Ford briefly imposed retaliatory measures on power exports.

Bob Walker from the Canadian Nuclear Workers’ Council expressed concerns about relying on foreign nuclear fuel, stating, "Developing a dependence on another country for our nuclear fuel has always been a concern, and recent events have proven those concerns are justified."

OPG's Neal Kelly called the situation "very fluid" and emphasized ongoing evaluations of potential impacts without commenting on alternative plans.