REGULATORY INTELLIGENCE
HOW REACTORS GET APPROVED
Four pathways. Different rules.
Different timelines. Same goal.
Different timelines. Same goal.
PART 52
5–15 YR
Standard design approval + combined license. The long road.
TerraPower · Kairos · GE Vernova
PART 53
3–7 YR (est)
New framework for advanced reactors. Still being written.
University of Illinois (first filer)
DOE PILOT
MONTHS
EO 14301 pathway. DOE Atomic Energy Act authorization. July 4 deadline.
Valar · Radiant · Oklo · Antares · Aalo
SPACE NUCLEAR
TBD
DOE authorization, not NRC. New OSTP initiative April 2026.
NASA · DARPA · DoD · BWXT
APRIL 14, 2026 · SPACE NUCLEAR
Trump Administration launches National Initiative for American Space Nuclear Power — reactors in orbit by 2028, on Moon by 2030 →
APRIL 6, 2026 · NRC RULEMAKING
NRC proposes EO14300 rule accepting DOE demonstration data for commercial licensing — public comment until May 4, 2026 →
APPROVAL PATHWAYS
APPROVAL PATHWAYS
Select a pathway to explore
WHAT GETS REGULATED
WHAT GETS REGULATED
Reactors aren't the only thing that needs approval
NRC-Licensed Reactors
Commercial nuclear reactors in the US require a license from the Nuclear Regulatory Commission under 10 CFR Part 50, 52, or 53. This includes design certification of the reactor itself, environmental review of the site, and safety evaluation by NRC staff.
VIEW NRC PATHWAYS →DOE Pilot Reactors
Under EO 14301, DOE has emergency authority to demonstrate reactors without going through the full NRC commercial licensing process. DOE reactors must still meet safety requirements, but are authorized by DOE rather than NRC.
VIEW DOE PILOT →Part 50 note — TerraPower Natrium is licensed under the older 10 CFR Part 50 Construction Permit pathway. Part 50 separates the construction permit and operating license into two distinct applications. TerraPower chose this path because Natrium's SFR technology was not covered by Part 52 design certification rules at the time of application, and Part 53 had not yet been finalized.
SECTION — DOE FUNDING
DOE FUNDING PATHWAYS
Three parallel federal funding mechanisms de-risk advanced nuclear development. ARDP provides cost-shared construction grants, LPO provides low-cost debt, and the HALEU program develops the fuel supply chain that most advanced designs require.
SOURCE: DOE-NE — ARDP Award Agreements 2020–2023 · DOE LPO Conditional Commitments · DOE HALEU Availability Program FOA · IRA §40323
REGULATORY TIMELINE
KEY DATES
APR 14, 2026
Trump Administration launched National Initiative for American Space Nuclear Power directing NASA, DoD, and DOE to accelerate space fission systems for orbit, Moon, and Mars.
APR 6, 2026
NRC EO14300 rulemaking — DOE data accepted for commercial review
NRC proposed rule implementing EO 14300, allowing DOE demonstration program operational data to be used as evidence in commercial NRC licensing applications. Public comment period closes May 4.
MAR 4, 2026
TerraPower Construction Permit issued — first advanced reactor CP in US history
NRC issued Construction Permit for TerraPower Natrium sodium-cooled fast reactor at Kemmerer, Wyoming. First CP issued to an advanced non-LWR reactor in the United States.
NOV 2025
Valar criticality achieved — first DOE Pilot criticality
First reactor to achieve criticality through the DOE Emergency Authorization Pilot pathway under EO 14301.
MAR 31, 2025
Part 53 final rule published in Federal Register
10 CFR Part 53 — the technology-inclusive, risk-informed framework for advanced non-LWR reactors — published as a final rule. Effective July 15, 2025. First new NRC licensing framework in 36 years.
2023
NuScale Standard Design Approval — first SMR design certification
NRC approved NuScale VOYGR-6 Standard Design Approval, the first small modular reactor design certification in US history. UAMPS CFPP project cancelled the same year.
2022
Oklo NRC rejection — application resubmitted under Part 53
NRC rejected Oklo Aurora combined license application for insufficient safety analysis. Oklo refiled under the new Part 53 framework.
2016
Part 53 rulemaking initiated
NRC formally began rulemaking to create a technology-inclusive, risk-informed, performance-based licensing framework for advanced reactors. Nine years from initiation to final rule.