A nuclear startup just powered an Nvidia Blackwell chip with an advanced reactor

A California nuclear startup called Valar Atomics pulled off something this week that no one in the United States has done before with a next-generation reactor: it used one to power an AI chip.

On Wednesday, Valar connected its Ward 250 advanced reactor to an Nvidia Blackwell chip at a test facility in Utah and ran a live website off the setup. The amount of electricity generated was tiny — this was a demonstration, not a power plant — but it’s the first time an advanced reactor design has actually driven AI hardware.

The company also announced a partnership to build a small data center at the same Utah site, designed to test how AI computing facilities can run on advanced nuclear power combined with closed-loop liquid cooling, cutting their dependence on the electrical grid and water supplies.

Valar’s Ward 250 reactor had already reached criticality last month — meaning it achieved a self-sustaining chain reaction. This week’s power demonstration was the next step.

The company is one of a growing number of startups working on advanced reactor designs that use new materials and configurations to improve safety and efficiency. But the industry is still in its early stages. No advanced reactor is yet operating commercially in the United States.

AI data centers are hungry for electricity. International Energy Agency projections suggest AI-related energy consumption could rival entire mid-sized countries within a few years. Nuclear power’s steady carbon-free output makes it an increasingly attractive option.

Valar’s demo was tiny. But it showed the pieces can actually work together.