US Rewrites Nuclear Rulebook After 37 Years

The NRC's new Part 53 framework promises faster, lower-cost licensing for advanced and small modular reactors beginning April 29.

25 Jun 2026

America has rewritten its nuclear licensing playbook for the first time in nearly four decades. Approved by the Nuclear Regulatory Commission on March 25 and 26, 2026, the new 10 CFR Part 53 framework took effect on April 29, creating a more flexible path for licensing advanced reactors and small modular reactors.

For years, existing licensing rules were built around conventional light-water reactors, leaving developers of newer technologies to navigate lengthy reviews, higher costs, and regulatory hurdles that often delayed projects before construction could begin. Part 53 replaces that one-size-fits-all approach with performance-based requirements that can accommodate a broader range of reactor designs.

NRC Chairman Ho Nieh described the decision as "a historic milestone," saying the United States now offers applicants multiple pathways to develop and deploy next-generation nuclear technologies. That flexibility could strengthen the country's appeal to both domestic developers and overseas investors looking for a clearer route into the American market.

Beyond reactor developers, the commercial impact reaches utilities, manufacturers, and data center operators seeking dependable, low-carbon electricity. Faster licensing can reduce capital tied up during regulatory reviews, improve project economics, and make financing easier to secure, while suppliers of reactor components could benefit as projects move from concept to construction with greater certainty.

Importantly, Part 53 is optional. Developers may continue using existing licensing pathways if they better suit a project, allowing the industry to adopt the new framework at its own pace. Its long-term success will depend on how efficiently the first applications move through the process, but the rule gives advanced nuclear technology its clearest regulatory opening in decades.