A wave of new nuclear companies has emerged, driven by the need for clean baseload power. Particularly Big Tech companies and data center builders are driving enthusiasm for the technology.
Start-ups are revitalizing the nuclear sector with advanced technologies like small modular reactors (SMRs), microreactors and fusion reactors.
- Small modular reactors (SMRs) are compact reactors, typically up to 300 megawatts in size and built in factories for faster cheaper deployment. They’re designed for flexible, scalable power.
- Microreactors are ultra-small, portable nuclear reactors (1 to 20 megawatts) designed for quick setup in remote or isolated areas. Their passive safety features and compact designs make them suitable for regions without extensive infrastructure.
- Fusion reactors generate energy by fusing atomic nuclei to produce significant amounts of electricity without long-lived radioactive waste. They’re inherently safer than fission and use abundant fuels but are still in development.
The start-ups are attracting attention and funding from both governments and private investors by promising carbon-free power with high reliability. Their approach is often more agile than that of traditional nuclear companies, with faster R&D cycles.
Nuclear start-up details
| Company Name | Reactor Type | Technology |
| TerraPower | Small Modular Reactor | Natrium sodium-cooled fast reactor |
| NuScale Power | Small Modular Reactor | Pressurized water-cooled reactor technology |
| Terrestrial Energy | Small Modular Reactor | Molten salt fission technology |
| X-energy | Small Modular Reactor | High temperature gas-cooled reactor |
| Last Energy | Small Modular Reactor | Four-loop pressurized water reactor |
| Kairos Power | Small Modular Reactor | Fluoride salt-cooled high temperature reactor |
| ARC Clean Technology | Small Modular Reactor | Sodium-cooled fast neuron reactor |
| Newcleo | Small Modular Reactor | Lead-cooled fast reactor |
| Rolls-Royce SMR | Small Modular Reactor | Three-loop pressurized water reactor |
| EDF Nuward | Small Modular Reactor | Pressurized water-cooled reactor technology |
| Oklo | Microreactor | Fast neutron reactor |
| Radiant | Microreactor | High temperature gas reactor |
| Ultra Safe Nuclear Corporation | Microreactor | High temperature gas reactor |
| Proxima Fusion | Fusion reactor | Magnetic confinement fusion |
| Commonwealth Fusion Systems | Fusion reactor | Magnetic confinement fusion |
| Helion Energy | Fusion reactor | Magneto-inertial fusion |
| General Fusion | Fusion reactor | Magnetic confinement fusion |
| Zap Energy | Fusion reactor | Sheared-flow-stabilized Z-pinch fusion |
| Tokamak Energy | Fusion reactor | Magnetic confinement fusion |
| First Light Fusion | Fusion reactor | Projectile inertial fusion |
| HB11 Energy | Fusion reactor | Laser inertial fusion |
| Marvel Fusion | Fusion reactor | Laser inertial fusion |
| Renaissance Fusion | Fusion reactor | Magnetic confinement fusion |
| Pacific Fusion | Fusion reactor | Pulsed magnetic inertia fusion |
Over the coming decade, advanced reactors will have to go through regulatory approval processes before they can be built. There is currently a wave of enthusiasm about the sector, but time will tell whether the public is open to building new nuclear reactors in their communities.
Aaron Foyer is Vice President, Research and Analytics at Orennia. Prior to Orennia, he leveraged his technical background in management consulting and finance roles. He has experience across the energy landscape including clean hydrogen, renewables, biofuels, oil and gas, petrochemicals and carbon capture.
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