Who licenses small modular reactors in the US?

The Nuclear Regulatory Commission, under 10 CFR Part 50, Part 52 or, optionally, the new Part 53. Agreement States do not license power reactors.

What is 10 CFR Part 53?

An optional, risk-informed, performance-based and technology-inclusive licensing framework for commercial nuclear plants, published as a final rule in March 2026 in response to NEIMA.

What is an Agreement State?

A state that has taken over regulatory authority from the NRC for certain radioactive materials under Section 274 of the Atomic Energy Act.

What is a combined license?

A Part 52 license that authorizes both construction and operation of a nuclear power plant, often referencing a certified design.

How US nuclear regulation works: NRC, Agreement States and 10 CFR Parts 20, 50, 52 and 53

Who regulates a reactor, a gauge or a national laboratory depends on what it is and who owns it. This page maps the main laws and rules at a general level.

Study text drafted from public-domain US government sources. Practice questions are reviewed before publication.

Laws and agencies

The Atomic Energy Act of 1954 is the foundation of civilian nuclear regulation. The Energy Reorganization Act of 1974 split the old Atomic Energy Commission, creating the Nuclear Regulatory Commission (operating from January 1975) for regulation, while research went to what later became the Department of Energy. The Price-Anderson provisions of the Atomic Energy Act, first enacted in 1957, provide liability coverage for the public after a nuclear incident.

Under Section 274 of the Atomic Energy Act, most states have become Agreement States that license radioactive materials such as industrial gauges and medical uses. The NRC keeps authority over power reactors everywhere, so every SMR is NRC-licensed. DOE regulates occupational radiation protection at most of its own facilities under 10 CFR Part 835. Worker protection rules under NRC licenses are in 10 CFR Part 19 (notices, instructions, worker rights) and Part 20 (dose limits and radiation protection programs).

Licensing reactors: Parts 50, 52 and 53

Under 10 CFR Part 50, a plant receives a construction permit and later an operating license. Part 52 offers early site permits, standard design certifications (issued by rule, like NuScale's Appendix G), combined licenses that authorize construction and operation together, standard design approvals and manufacturing licenses. NRC staff review applications against guidance such as NUREG-0800, the Standard Review Plan.

The Nuclear Energy Innovation and Modernization Act (NEIMA) of 2019 directed the NRC to build a technology-inclusive framework for advanced reactors. The resulting 10 CFR Part 53 final rule was published on March 30, 2026 and took effect on April 29, 2026. It is voluntary and risk-informed: applicants may use it or stay with Parts 50 and 52.

Sample quiz

Practice questions for this section are being reviewed.

Practice questions for this section are still in review and will appear here once they have been checked.

Frequently asked questions

Who licenses small modular reactors in the US?: The Nuclear Regulatory Commission, under 10 CFR Part 50, Part 52 or, optionally, the new Part 53. Agreement States do not license power reactors.
What is 10 CFR Part 53?: An optional, risk-informed, performance-based and technology-inclusive licensing framework for commercial nuclear plants, published as a final rule in March 2026 in response to NEIMA.
What is an Agreement State?: A state that has taken over regulatory authority from the NRC for certain radioactive materials under Section 274 of the Atomic Energy Act.
What is a combined license?: A Part 52 license that authorizes both construction and operation of a nuclear power plant, often referencing a certified design.

Sources

Atomic Energy Act of 1954, as amended (42 U.S.C. 2011 et seq.)
NUREG-1350, NRC Information Digest
10 CFR Part 50, Domestic Licensing of Production and Utilization Facilities (U.S. NRC) www.ecfr.gov
10 CFR Part 52, Licenses, Certifications, and Approvals for Nuclear Power Plants (U.S. NRC) www.ecfr.gov
U.S. NRC final rule, Risk-Informed, Technology-Inclusive Regulatory Framework for Advanced Reactors (10 CFR Part 53), Federal Register 2026-06048 www.federalregister.gov
Nuclear Energy Innovation and Modernization Act (NEIMA), Pub. L. 115-439
U.S. NRC final rule, NuScale Small Modular Reactor Design Certification, Federal Register 2023-00729 www.federalregister.gov
10 CFR Part 20, Standards for Protection Against Radiation (U.S. NRC) www.ecfr.gov

Explanations on this page are original. Cited US government works are in the public domain; they do not endorse this site.