A NVIDIA Blackwell chip powered by a nuclear reactor: it really happened in the USA
The Californian startup Valar Atomics has announced that it has completed a demonstration that it calls a first in the United States: using electricity produced by a next-generation nuclear reactor to power an NVIDIA Blackwell processor.
The demonstration took place at a facility located in Emery County, where the Ward 250 reactor prototype generated a small amount of electricity subsequently directed to a system based on NVIDIA hardware. The power was used to temporarily operate a web server, demonstrating the possibility of directly using the reactor's electricity production for computational workloads.
According to Valar Atomics, it is the first U.S. nuclear startup to produce electricity with its own reactor and use it to power a platform based on NVIDIA technology. For the occasion, Valar Atomics and NVIDIA announced a collaboration aimed at studying computing infrastructures powered by advanced nuclear reactors. The stated objective is to design a 30 MW data center completely independent of municipal water supply.
The project arises from the increasing pressure exerted by artificial intelligence systems on electrical networks and water resources: traditional evaporative cooling systems in data centers consume large amounts of water.
To reduce this impact, the future infrastructure is expected to combine the reactor developed by Valar Atomics, designed to operate without using water as a cooling fluid, with a closed-loop cooling system developed by NVIDIA.
The demonstration came after a significant milestone was reached last month, when the Ward 250 reactor successfully completed its first controlled nuclear chain reaction. Before introducing nuclear fuel, the team had validated the design through an experimental platform called Ward Zero, a non-nuclear replica of the reactor. Within the prototype, silicon carbide heating elements were installed to simulate high operational temperatures and verify the behavior of structures under extreme thermal stress.
The technology developed by Valar Atomics is based on a High-Temperature Gas-Cooled Reactor (HTGR), an architecture the company identifies as Numenor. The system uses low-enriched uranium encapsulated in TRISO fuel particles, while heat transfer occurs through helium gas rather than water.
The use of TRISO fuel and gas cooling significantly alters the safety profile of the plant. According to the company, the reactor is designed so that residual heat can dissipate naturally even in the event of severe failures, without the need for pumps, emergency electrical supplies, or automatic mechanical systems. Additionally, TRISO particles are difficult to reuse for military applications, helping to limit nuclear proliferation risks.
The high operational temperatures also allow for the production of not only electricity but also high-quality heat usable directly in industrial plants, such as in chemical or manufacturing processes, improving the overall energy efficiency of the system.
Despite the technical success of the demonstration, the commercial deployment of advanced nuclear reactors remains far off. In the United States, the sector is predominantly composed of experimental projects, and currently, no next-generation advanced nuclear reactor has yet obtained certification from federal authorities for large-scale commercial use.