Thorium, 3D Printing, and No Uranium: Ampera's Nuclear Plan for AI Data Centers
Ampera has presented the first complete specimen of its 3D-printed nuclear reactor, designed to provide energy for artificial intelligence data centers. The module, shown on July 1 at the company’s innovation center in Palm Beach Gardens, Florida, in front of over 100 people including local officials and entrepreneurs, is described by the company as the first solid-state, subcritical reactor entirely factory-built and powered by thorium.
The heart of the system is a monolithic spherical core with gyroid geometry, printed in silicon carbide. This is a complex shape, nearly impossible to achieve with traditional manufacturing techniques, maximizing the heat exchange surface relative to the occupied volume. The geometrical complexity of the design has driven Ampera towards additive manufacturing, the only viable path to shape such a structure.
The fuel used is thorium-based, encapsulated in TRISO (tristructural isotropic) particles: a fuel kernel surrounded by multiple layers of ceramic and carbon. Thorium is more abundant and less expensive than uranium, but is not itself fissile; it requires an external neutron source to trigger the transformation into protactinium-233, which then decays into uranium-233. This characteristic makes it, according to the World Nuclear Association, more difficult to use for military purposes compared to traditional nuclear fuels.
Intrinsic Safety, but Long Timelines
The subcritical nature of the reactor means that the fuel cannot sustain a chain reaction on its own: without an external source to trigger it, fission stops, drastically reducing the risk of a core meltdown. The solid-state design, devoid of moving parts, should also simplify maintenance and operational management compared to conventional reactors.
The nuclear module is part of Ampera's broader Integrated Energy Architecture, which also includes a waste heat recovery unit and a conventional fuel generator, modularly combinable according to customer needs. For electricity conversion, the company has developed a proprietary closed-loop supercritical CO2 Brayton cycle turbine, with a stated goal of 30 MWe per configuration (up to 15 MWe for smaller versions), sufficient to power a typical-sized data center.
Founder and CEO Brian Matthews described the new core and its pressure vessel as "the basis for factory-built, industrial-scale nuclear energy production," emphasizing how the additive technology employed demonstrates "a concrete commercial pathway" to bring the new generation of reactors to market "in accelerated timelines." Ampera, he added, is targeting sectors with the highest energy demands: AI data centers, defense, industry, and maritime.
Regarding timelines, the company remains cautious: the gas-powered electricity generation component is expected to be available as early as 2027, while the actual nuclear module will reach customers only around 2030, subject to regulatory approval. This is a noteworthy detail, considering that no commercial thorium reactor is currently operational in the United States, and certification timelines for novel nuclear technologies typically span years, if not decades.
Comparing with competitors helps frame the milestone achieved: Valar Atomics has already activated its Ward 250 microreactor, generating enough electricity to power an Nvidia RTX Spark desktop, and announced a partnership with Nvidia for a 30 MW data center. For now, Ampera stops a step short: it has showcased the hardware, but not the energy production.