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Courses › Supplemental Nuclear: Small Modular Reactors

Lesson 3 of 9 · about 16 minutes

Manufacturers and where each stands with regulators

You'll be able to

  • Give the regulatory status of the main SMR and microreactor vendors as of October 2026
  • Tell an NRC license from a DOE authorization and a design approval from a construction permit
  • Compute review times from docket dates
  • Find a project's live status on the NRC website

Every vendor has a press page that makes its reactor sound nearly finished. The regulator's record is where the real status lives. In the United States that is usually the Nuclear Regulatory Commission. For test and demonstration reactors on federal sites it is the Department of Energy, and in Canada it is the Canadian Nuclear Safety Commission. This lesson puts the main vendors side by side, then shows how to check the status yourself, because the table below will be out of date within months.

For what each licensing step allows, see the table in the SMRs and advanced reactors lesson. For how the NRC works and what changed in 2024 and 2025, see who regulates nuclear power.

The vendor table, October 2026

Vendor and designFamily, sizeRegulator and statusKey dates
NuScale Power, US460 (VOYGR plants)Light-water, 77 MWe modules, 6 per plantNRC standard design approval. No U.S. construction permit application under review.50 MWe design certified by rule Jan. 19, 2023; US460 approved May 2025
GE Vernova Hitachi, BWRX-300Boiling water, up to 300 MWeNRC construction permit to TVA at Clinch River, Tenn. Canadian licence to construct at Darlington, Ont.Clinch River permit reported Sept. 30, 2026, after a 14-month review; CNSC licence April 4, 2025
Holtec, SMR-300Pressurized water, about 340 MWe each, 2 unitsPartial construction permit application and limited work authorization request for Palisades (Mich.), accepted by the NRCPart 1 submitted Dec. 31, 2025; accepted February 2026; final safety and environmental reviews expected March 2027
TerraPower, NatriumSodium fast, 345 MWe, up to 500 MWe with storageNRC construction permit, Kemmerer Unit 1 (Wyo.). Operating license still needed.Permit March 4, 2026; construction began April 23, 2026; completion expected 2030
X-energy, Xe-100Helium gas, about 80 MWe each, 4 unitsNRC construction permit review for Long Mott (Seadrift, Tex.)Docketed May 12, 2025; EA and FONSI May 18, 2026; final safety evaluation targeted November 2026; permit decision not yet scheduled
Kairos Power, Hermes and Hermes 2Salt-cooled, TRISO pebbles; Hermes 2 aimed at 50 MWeNRC construction permits for both test reactors (Oak Ridge, Tenn.). Operating licenses still needed.Permits 2023 and November 2024; Hermes 2 groundbreaking April 17, 2026
Oklo, AuroraLiquid-metal fast, up to 75 MWeDOE authorization at INL; preliminary safety analysis approved. First NRC application denied in 2022.Groundbreaking September 2025; PDSA approved June 2026; no operating date set
Aalo Atomics, Aalo-XSodium-cooled, 10 MWeDOE authorization at INL (Reactor Pilot Program)DSA approved May 2026; critical test reactor reached criticality July 4, 2026
Radiant, KaleidosHelium gas, 1 MWeDOE authorization for testing in INL's DOMEFuel delivered July 2026; reactor shipped to INL August 2026; testing expected to begin in 2026
Westinghouse, eVinciHeat pipe, 5 MWe commercial; 1 MWe prototypeTesting with DOE labs. Not on the NRC's June 2026 list of applicants under review.Zero-power criticality experiment on a scaled core mock-up in Nevada reported Aug. 27, 2026; DOME testing planned 2027 to 2028
Terrestrial Energy, IMSR (Project Tetra)Fuel-in-salt, 390 MWeDOE agreement under the Reactor Pilot Program; site lease at Texas A&M RELLISAgreement January 2026; lease June 2026
Natura Resources, MSR-1Fuel-in-salt research reactorAbilene Christian University holds an NRC construction permit (issued September 2024); DOE agreementPer ANS reporting, July 2026

The only U.S. sites with NRC construction permits for commercial-scale SMRs are Clinch River and Kemmerer. Most microreactor activity runs through DOE instead. A DOE authorization lets a company build and test on a federal site, and it stops short of a license to sell power commercially. Moving from an INL demonstration to a fleet of customer sites puts the vendor back in front of the NRC.

How the review clocks compare

Reviews are getting shorter. Executive Order 14300 (May 2025) told the NRC to decide on new reactor applications within 18 months, and the ADVANCE Act of 2024 pushed in the same direction. Supporters see a regulator finally matching its pace to the technology. Former NRC officials and groups like the Union of Concerned Scientists warn that deadlines and staff cuts can squeeze out the scrutiny the process exists for. The record so far shows faster reviews. It cannot yet show whether anything was missed, because none of these reactors has run.

Example: computing review times

  • TVA Clinch River: NRC review began July 2025. Permit reported September 30, 2026. July 2025 to September 2026 is 14 months.
  • Long Mott: docketed May 12, 2025. Final safety evaluation targeted November 2026. May 2025 to November 2026 is 18 months, and the permit decision comes after the safety evaluation and a hearing, so the full clock will run a little longer.
  • Natrium: TerraPower and the NRC describe an 18-month review, against an initial 27-month schedule. 27 minus 18 = 9 months saved, or a third of the original schedule.

For comparison, Vogtle 3 and 4 used a combined license issued in 2012 after a review that began in 2008. Short reviews are new.

Checking status yourself

  1. Start at the NRC's applicant projects page. It lists active applications. A design not on that list is not under NRC review, whatever the press release implies.
  2. Open the project page. Each lists submittal dates, docketing, the review schedule, safety evaluation milestones and hearing dates. Look for the "page last updated" date at the bottom.
  3. Note the docket number and search it in ADAMS, the NRC's document system, for the newest letters. Requests for additional information show what the staff found thin.
  4. For DOE-authorized projects at INL, look for DOE Idaho Operations Office approvals of safety documents (the PDSA and DSA). Company announcements and trade press like ANS Nuclear Newswire usually report these within days.
  5. For Canadian projects, the CNSC posts licences and hearing records. OPG posts construction updates for Darlington.

Example: reading a press release against the record

An invented vendor, Ridgeline Atomics, announces that its reactor "has cleared a key federal milestone and is on track for 2028 deployment."

  • Check the NRC applicant list. Ridgeline isn't on it.
  • Check DOE. Ridgeline has a preliminary safety design strategy approved for a test unit at a national lab.
  • So the "federal milestone" is an early DOE document for a test reactor. The 2028 date refers to the company's hope, not a regulator's schedule. A fair one-line summary: "Ridgeline has early DOE approval to test a prototype; it has not applied to the NRC for a commercial license."

Common mix-ups

  • Claim: NuScale's design is approved, so NuScale plants are licensed. What the evidence shows: The design approval covers the design only. Any plant still needs a site-specific permit or license, and none was under NRC review as of October 2026.
  • Claim: A construction permit means a reactor can run. What the evidence shows: Under Part 50, the operating license is a second review. Kemmerer and Clinch River both still need one.
  • Claim: DOE-authorized reactors at INL are NRC-licensed. What the evidence shows: They are authorized by DOE under its own authority for reactors it controls that do not sell commercial power.

Reporting angle

  • Ask every developer for its NRC docket number or its DOE authorization documents. No number means no application.
  • Bookmark the NRC project page and record the "last updated" date each time you cite it.
  • Watch the Federal Register for notices of hearing opportunity on any application near you. That 60-day window is when residents and groups can petition to intervene.
  • Read the NRC's environmental assessment or impact statement for the project; it holds the water, traffic and emergency planning numbers.
  • For DOE projects at INL, ask DOE Idaho for the PDSA and DSA approval letters and for what public review, if any, occurred under NEPA.

Research angle

Check yourself

1. As of mid-October 2026, which X-energy milestone had the NRC reached for Dow's Long Mott project?

2. Which vendor's design holds an NRC standard design approval but no U.S. construction permit at any site as of October 2026?

3. Oklo's Aurora at Idaho National Laboratory is moving forward under which authority?

4. The NRC docketed Long Mott on May 12, 2025, and targets the final safety evaluation for November 2026. About how long is that review?

5. Who licensed construction of the first BWRX-300 in Ontario?

Terms in this lesson

Standard design approval (SDA)
An NRC finding that a reactor design is acceptable. It approves no site and allows no construction.
Construction permit (CP)
NRC permission under 10 CFR Part 50 to build a specific reactor at a specific site. An operating license is a separate later step.
Docketing
The NRC's formal acceptance of an application as complete enough to review. Review clocks usually start here.
Documented safety analysis (DSA)
The DOE safety basis document a DOE-authorized reactor needs approved before it can operate; a preliminary version (PDSA) comes first.
Limited work authorization (LWA)
NRC permission to do certain safety-related site work before a construction permit is issued.

Full glossary

Sources