NRC SMR Licensing in 2026: Part 53 Is Final, Part 57 Is Next, and the First Advanced Reactors Break Ground
NRC SMR licensing is changing fast: the US regulator has finalised a new framework for advanced reactors, proposed another for microreactors, and issued its first permit for a commercial non-water-cooled plant in more than 40 years.
NRC SMR licensing: the rule changes
The push comes from Executive Order 14300, signed in May 2025. It told the NRC to rewrite its rules within 18 months and to decide new reactor applications within 18 months, as POWER magazine explains.
- Part 53 (final). Unveiled in March 2026 and described as the first new reactor licensing framework since 1989. It is technology-neutral, and the NRC expects reviews of 18 months or less. It took effect on 29 April 2026.
- Part 57 (proposed). Announced on 24 April 2026 for microreactors and similar low-risk designs, which the NRC chairman said means roughly 100 MWe or smaller. The NRC projects licensing in 6 to 12 months. Comments closed in June, and I could not confirm a final rule yet.
Designs, permits and projects
- NuScale: the NRC approved the uprated 77 MWe design, but this was in May 2025, not 2026. A design approval is not a permit to build.
- TerraPower, Kemmerer (Wyoming): the NRC issued construction permit CPAR-1 on 9 March 2026. It is the first approval for a non-light-water commercial reactor in over 40 years, and the staff review took under 18 months. An operating licence is still required.
- Kairos Power, Hermes 2 (Tennessee): ground was broken on 17 April 2026. The 50MWe plant is planned to supply the Tennessee Valley Authority and Google data centres.
- Seadrift (Texas): Dow’s Long Mott Energy and X-energy filed a construction permit application for Xe-100 reactors in March 2025. The NRC is aiming for an 18.5-month review, and no decision has been reported.
A fair reality check
- Faster rules are not faster plants. Permits, operating licences, fuel supply and construction all still sit ahead of these projects.
- The NRC chairman has said some final rules will land beyond the 18-month target.
- Market forecasts vary widely. A figure of more than $200 billion by 2031 did not stand up in our checks. MarketsandMarkets, for example, estimates $7.14 billion by 2030, though definitions differ between reports.
- Natrium is an advanced sodium-cooled reactor, not strictly a small modular reactor.
GO-IBR Research Team take
For compliance and regulatory teams, the useful signal is the framework itself. Part 53 and the proposed Part 57 give developers risk-informed, performance-based routes in place of exemption-heavy reviews. Watch whether the NRC meets its own review clocks on TerraPower’s operating licence and the Seadrift permit, because that will show if the reforms hold up in practice.
Last updated 22 October 2026. Sources: POWER magazine; Nuclear Engineering International; American Nuclear Society; US NRC; World Nuclear News; MarketsandMarkets.
By the GO-IBR Research Team. © go-ibr.com
