The latest

The first US small modular reactor (SMR) developers are moving ahead with their reactor designs, and utilities are eyeing construction permit applications with the Nuclear Regulatory Commission (NRC). The Tennessee Valley Authority’s construction permit for GE-Hitachi’s BWRX-300 has been accepted by the NRC, and Kairos Power is developing its SMR in Oak Ridge, TN. TerraPower has begun (non-nuclear) construction at a retiring coal plant in Kemmerer, WY, where the company plans to install an advanced nuclear reactor by 2030.

Relevance

Nuclear technology is gaining importance for geopolitical, climate, and development reasons. 

• The US is already far behind Russia and China. Russia has far more nuclear agreements and has already deployed a floating SMR in Pevek. China operates an SMR in Shidao Bay.
• The US and 24 other countries have pledged to triple global nuclear power to provide zero-emission firm power.
• Smaller, safer, and more flexible models, such as SMRs and microreactors are likely to be especially attractive in emerging markets to boost economic growth and support industry.
• New US executive orders and a DOE Nuclear Reactor Pilot Program aim to accelerate nuclear development and quadruple US nuclear energy capacity by 2050.

The urgency

Fixing the financing gap. Despite likely demand for nuclear power in Asia and Africa, institutions that fund infrastructure are not yet ready to finance nuclear technology. The primarily reasons are: (a) lack of specific projects ready for financing, (b) limited in-house expertise, and (c) lingering prohibitions, legal or implicit, on supporting nuclear technology. Since the lead times for nuclear deals are long, and countries need time to prepare to adopt and oversee the technology, the evolving market could move faster than policy. It’s not too late for the financing agencies to catch up. The good news is that the World Bank has lifted its longstanding ban on financing nuclear, setting the stage for more financing agencies to follow suit.

Which next-generation nuclear models to watch? And when will they come to market? 

Several leading US advanced nuclear developers are on pace to launch demonstration projects by the end of the decade. It can be hard to keep track, so we’ve summarized public information on 10 of the most promising US companies that we’re keeping an eye on.

Most promising based on public information:

Oklo

• Model: Aurora Powerhouse
• Technology specs: 15-75 MWe liquid metal-cooled fast reactor that can be fueled by recycled fuel.
• 2025 status update: Completed the NRC’s readiness assessment and completed borehole drilling to determine the suitability of a construction site in 2025. Oklo is included in the DOE’s pilot program.
• Expected demo launch: 2028 or sooner.
• Expected commercial launch: 2028

GE Hitachi

• Model: BWRX-300
• Technology specs: 300 MWe water-cooled, water-moderated version of GE’s legacy nuclear reactor design that uses a common fuel. Since the BWRX-300 is a smaller reactor design similar to an already-approved nuclear reactor design, GE has stated that the Nuclear Regulatory Commission has already approved 80 percent of its components.
• 2025 status update: GE Hitachi, the Tennessee Valley Authority, and supply chain partners have formed a coalition to accelerate deployment of the BWRX-300 in Tennessee (Clinch River) and Indiana (Rockport).
• Expected demo launch: 2029 for Ontario Power Generation (Canada), with later pilots for Tennessee Valley Authority (USA) and Synthos Green Energy (Poland).
• Expected commercial launch: 2033

X-energy

• Model: Xe-100
• Technology specs: 80 MWe reactor that can be scaled into a 4x solution to create a 320MWe power plant. The Xe-100 uses TRISO fuel and has extensive passive safety features.
• 2025 status update: In 2025, the NRC published an 18-month review timeline for X-energy’s first project and will concurrently proceed with its environmental assessment, with commercial demonstration expected to follow.
• Expected demo launch: Construction is expected to start in 2026 and operations in 2029 for a Dow Chemical plant in Texas.
• Expected commercial launch: 2029 or 2030

TerraPower

• Model: Natrium
• Technology specs: 345 MWe sodium fast reactor combined with a molten salt energy storage system developed in partnership with GE Hitachi and with the support of the Department of Energy.
• 2025 status update: Secured $650m in new investment from NVIDIA and HD Hyundai. The company now has $3.4bn in funding ($2bn from DOE, $1.4bn from private sources) to build its Natrium reactor.
• Expected demo project launch: Construction begun at Kemmerer, Wyoming, in June 2024. The goal for the demo project launch is set for 2030.
• Expected commercial launch: 2032

Potentially Promising Based on Public Information:

Holtec

• Model: SMR-300 and SMR-160
• Technology specs:
  • SMR-300 is a small modular pressurized water reactor producing 300 MWe. It uses steam to make power in a conventional Rankine power cycle and features passive safety features.
  • SMR-160 is a 160 MWe reactor. It relies on gravity for critical safety systems.
• 2025 status update: Holtec is partnering with Hyundai Engineering & Construction to build 10 GW of generation capability with SMRs in North America in the 2030s.
• Expected demo launch: The company plans to submit in 2026 for construction permits for two SMR-300 reactors at the Palisades Nuclear Plant site (Michigan, US), with commissioning by the mid-2030s.
• Expected commercial launch: Holtec’s SMRs could start construction in the UK in 2028, and deployments are planned for 2029 in Ukraine and 2032 in the Czech Republic.

NuScale

• Model: NuScale Power Module
• Technology specs: A 77 MWe reactor design based on pressurized water-cooled reactor technology. NuScale’s plant models contain 4, 6, or 12 modules.
• 2025 status update: NuScale is the only SMR design that has received design certification and approval from the Nuclear Regulatory Commission. Its first planned pilot in Idaho was scrapped after the utility offtaker withdrew. NuScale, ENTRA1, and Tennessee Valley Authority launched a 6 GW SMR deployment program in September 2025.
• Expected demo launch: Unclear
• Expected commercial launch: Unclear

Kairos Power

• Model: KP-FHR
• Technology specs: 150 MWe fluoride salt-cooled reactor that uses TRISO fuel.
• 2025 status update: Installed the reactor pressure vessel for the company’s third test unit in Oak Ridge, TN, and unveiled a training simulator laboratory at the University of Tennessee in 2025. Google has partnered with Kairos to deploy 500 MW of power produced by advanced nuclear reactors.
• Expected demo launch: A low-power demo reactor is scheduled to be operational in East Tennessee in 2026.
• Expected commercial launch: 2035

BWX Technologies

• Models: Project Pele and BANR
• Technology specs:
  • Project Pele is a 1-5 MWe microreactor produced in collaboration with the Defense Department’s Strategic Capabilities Office. It uses Tri-structural Isotropic (TRISO) fuel and can be transported using truck, rail, ship, or a C-17 cargo plane.
  • BANR is a 50 MWe high-temperature gas reactor SMR that does not require extensive nuclear fuel handling facilities and storage due to its modular refueling compatibility. The reactors and accompanying infrastructure can be transported via truck, rail, or ship.
• 2025 status update: Construction of the Pele reactor core began in July 2025. The fuel is fabricated, and shipment to Idaho National Laboratory is pending.
• Expected demo launch:
  • A Project Pele construction broke ground at Idaho National Laboratory (INL) in 2024.
  • The Pele reactor is expected to start electricity production in 2028.
  • BANR’s viability is being evaluated under a two-year, two-phase contract between BWXT and the Wyoming Energy Authority. The assessment will determine the nuclear reactor’s viability as a source of energy alongside existing power generation sources.
• Expected commercial launch: 2030s

Westinghouse

• Model: AP300 & eVinci
• Technology specs: The AP300 is a 330 MWe pressurized water reactor. Scaled-down version of Westinghouse’s AP1000 design. Features proven passive safety systems and modular factory construction for faster deployment. eVinci is a 5 MWe micro reactor designed for transportability and quick on-site deployment.
• 2025 status update: Westinghouse has signed MoUs for deployment of the AP300 in New Brunswick, in Europe to serve data centers, and with suppliers of key equipment for the reactors. eVinci has received approval for its Preliminary Safety Design from the DOE, making it the first for a microreactor.
• Expected demo launch: 2030 (AP300)
• Expected commercial launch: 2030s

Natura Resources

• Model: MSR-100
• Technology specs: 100MW molten salt reactor.
• 2025 status update: Abilene Christian University granted a construction permit for a 1MW molten salt research reactor, which is to be followed by a commercial-scale MSR-100. Two developments of the MSR-100 were announced in Texas.
• Expected demo launch: No date available.
• Expected commercial launch: 2030s

Other companies that are developing next-generation models but which appear to be at an earlier stage or have less public information include: Aalo, Arc Clean Energy, Blykalla, Calogena, Copenhagen Atomics, Deep Fission, Hexana, Last Energy, Radiant, Stellaria, Terrestrial Energy, Thorcon, Thorizon, Valar Atomics.

DOE Reactor Pilot Program selections for July 2026 target: Aalo Atomics, Antares Nuclear, Atomic Alchemy, Deep Fission, Last Energy, Oklo, Natura Resources, Radiant, Terrestrial Energy, Valar Atomics.

Conclusion

Within the next five years, multiple new nuclear demonstration projects will launch, bringing commercial offerings closer to the marketplace. Countries considering advanced nuclear to meet their future electricity (and process heat) needs should watch these trends closely and begin securing the necessary long-term investment. Financing agencies, such as the World Bank and US Development Finance Corporation, dropping their nuclear bans were the first steps; next is to build in-house capacity to execute loans and investments into nuclear power.