AtkinsRéalis Group Inc., a Montreal-based company, has initiated the process to license its Enhanced Candu 6 (EC6) nuclear reactor in the United States, marking a significant move into a market historically closed to foreign vendors. On June 23, 2026, the company submitted a licensing application to the U.S. Nuclear Regulatory Commission (NRC) under a new streamlined process known as Part 53, which requires the NRC to decide on commercial nuclear power plant licenses within 18 months.

The EC6 is an updated 730-megawatt version of a reactor model originally developed in the 1970s and exported to countries including Argentina, Romania, Korea, and China. Because the design is not entirely new and previously underwent a Canadian prelicensing review over a decade ago, AtkinsRéalis aims to secure NRC approval in as little as 12 months, according to Joe St. Julian, president of AtkinsRéalis’s nuclear business.

The U.S. nuclear market has traditionally favored domestic technology, with more than 130 reactors built on designs from four American vendors, mostly boiling water and pressurized water reactors. As a result, foreign companies, including Canadian firms, have previously found it difficult to penetrate this market. Decades ago, Atomic Energy of Canada Ltd. (AECL), AtkinsRéalis’s predecessor, attempted to enter the U.S. market with reactors such as the Candu 3U and the Advanced Candu Reactor 700 (ACR-700). However, technical challenges during NRC reviews and lengthy licensing timelines contributed to the dissolution of partnerships, including one with Dominion Energy in the early 2000s.

Since then, the NRC has acknowledged that its regulatory framework has been primarily designed around American light-water reactor technology, which has posed challenges for licensing alternative designs like the heavy-water Candu reactors. The introduction of Part 53, mandated by President Donald Trump’s executive order in May 2025, aims to overhaul these regulations to accelerate the licensing process and support a fourfold expansion of U.S. nuclear generating capacity by mid-century. This includes staffing reductions and a push to reduce what the administration considered excessive regulatory oversight.

While this regulatory reshaping presents an opportunity for AtkinsRéalis and other foreign vendors, including South Korea’s Korea Electric Power Corp., it has raised safety concerns among critics. Former NRC chairs Stephen Burns, Allison Macfarlane, and Richard Meserve published a commentary warning that the accelerated timelines and reduced NRC independence under the Trump administration could lead to unintended safety risks. They described the new licensing deadlines as "arbitrary" and expressed apprehension over diminished regulatory rigor.

AtkinsRéalis is also developing a larger reactor, the Monark—an updated version of its 1980s-era Candu 850 model—with a planned capacity of 925 megawatts. The company intends to seek NRC licensing for the Monark after completing Canadian regulatory approvals.

Despite past challenges and ongoing debate about regulatory changes, AtkinsRéalis executives report positive engagement with the NRC and the U.S. government, viewing the current environment as favorable to expanding their presence in the American nuclear market. The company believes the limited capacity of domestic suppliers like Westinghouse Electric Co., which currently markets the AP1000 reactor, creates space for alternative technologies amid the anticipated growth in demand for nuclear power.