US-based nuclear technology startup Ampera has completed production of the first full-scale, 3D-printed nuclear reactor module at its Palm Beach Gardens innovation centre in Florida. The prototype consists of a full-scale, unfuelled silicon carbide reactor core and pressure vessel. It serves as the physical hardware foundation for their upcoming factory-built microreactors.
“This next-generation nuclear core and pressure vessel sets the foundation for factory-built, mass-produced nuclear energy,” said Brian Matthews, Ampera Founder & CEO. “The advanced technology and additive manufacturing used demonstrate a clear commercial path for new nuclear technology coming to market in an accelerated manner.”
The heart of the unit is a spherical monolithic gyroid core 3D-printed from silicon carbide. The highly complex gyroid geometry provides a massive surface area relative to its volume, maximising heat transfer efficiency. The system will be fuelled by tri-structural isotropic (TRISO) thorium kernels. In June, Ampera announced it had established an Australian subsidiary to secure thorium supply and support US advanced nuclear fuel production.
Unlike traditional uranium-fuelled plants, thorium requires an external neutron driver to start and sustain operations, ensuring it remains completely subcritical. Because the fuel cannot support a self-sustaining chain reaction on its own, it features inherent passive safety. Turning off the external neutron generator instantly stops the reaction, eliminating the risk of a meltdown.
Configurations are designed to produce 15-30 MWe. Ampera claims the factory-sealed reactor can run continuously for up to 30 years without needing a single refuelling. The reactor relies on a supercritical carbon dioxide closed-loop turbine instead of steam. This enables compact, water-free deployment in dry or remote regions.
Ampera is explicitly targeting high-consumption, critical infrastructure sectors that require immediate, localised power such as AI data centres (with immediate power partnerships, such as a collaboration with Nvidia), military & defence installations, heavy industrial facilities and maritime vessel propulsion.
Because the nuclear module requires strict regulatory approvals, the company recently revealed a “Power Now-Nuclear Next” strategy. This involves first releasing an Integrated Energy Architecture, which uses high-efficiency gas-powered systems and waste heat recovery. These conventional units share two-thirds commonality with the planned nuclear installation, allowing future operators to easily swap the gas module for the thorium reactor once cleared by the authorities.
Completion of a full, non-fuelled prototype assembly (including shielding, turbines, and heat exchangers is targeted for late 2026 Testing of a fully fuelled prototype with active thorium fuel breeding is planned for 2027, which will also see commercial availability of the conventional gas/waste-heat power generation modules. Projected commercial rollout and shipment of the full nuclear reactor modules, pending Nuclear Regulatory Commission (NRC) approval is targeted for 2030.
Ampera is intentionally leveraging NRC’s recently finalised 10 CFR Part 53 regulatory framework to license its subcritical thorium microreactor. This represents a major shift from legacy nuclear licensing. By initiating formal pre-application engagement in February, Ampera became one of the first advanced nuclear startups to use this pathway.
Previously, nuclear plants had to license under rules built exclusively for large-scale light-water uranium-fuelled reactors. 10 CFR Part 53 is a voluntary, technology-inclusive, performance-based alternative framework. Instead of forcing startups to comply with rigid design components meant for 1,000 MWe plants, regulators evaluate the actual safety and performance outcomes of the reactor.
According to Brian Matthews, Part 53 allows the company to focus entirely on licensing their new technology rather than spending years explaining how and why their design differs from a conventional 1970s light-water system. Ampera’s strategy relies on “Safeguards-by-Design”, using embedded artificial intelligence to assist with safety monitoring and tracking nuclear materials.
Because the reactor relies on a subcritical design that cannot sustain a chain reaction without an external driver, early NRC feedback has been positive regarding its inherent inability to experience a traditional meltdown. The licensing strategy is split into distinct regulatory branches:
- Reactor Oversight & Safety Case: Proving that the physical hardware and passive safety systems work under the new performance metrics.
- Materials Handling: Ensuring safe factory assembly and transport, since these reactors are designed to fit inside standard shipping containers.
- The Fuel Cycle: Working through regulations regarding thorium TRISO kernels.
Ampera is finalising agreements with Lawrence Livermore National Laboratory to develop the fuel technology and exploring fuelled testing protocols with Idaho National Laboratory. Ampera has submitted its formal Regulatory Engagement Plan and preliminary safety case methodologies to the NRC’s Office of Nuclear Reactor Regulation and the Division of Fuel Management and has scheduled its first public and technical alignment meetings with the regulator to lock in the final certification schedule.
