Startup Powers an Nvidia PC With Nuclear

At a live event, a team member from startup Valar Atomics plugged an Nvidia RTX desktop PC into a nuclear reactor, turned the reactor up to 37% of its power, and switched the machine on. That PC then served a live website, nuclearwebsite.com, which the company says stays online only as long as the reactor keeps running.

What it is

Valar Atomics activated its Ward 250 microreactor and used it to power a single Nvidia Blackwell chip. Blackwell is Nvidia's current generation of AI processor. A microreactor is a very small nuclear reactor, and a small modular reactor (SMR) is a compact, factory-built design meant to be deployed faster than a full-scale plant.

CEO Isiah Taylor walked the audience through the chain of events. Uranium atoms fissioning in the reactor hall produce about 100 kilowatts of thermal energy. A pressurized helium cooling loop carries that heat to a thermal electric generator, which converts it into electrical current. That current powered the Nvidia chip on stage.

The company also announced a partnership with Nvidia to build a 30-megawatt, closed-loop AI factory. The "closed loop" detail matters: the design is meant to avoid drawing on local water supplies.

Why it matters

Data centers have become a live political issue. They are being blamed for sharp rises in power and utility bills, higher water consumption, and a drop in quality of life for nearby communities. According to the source, 7 out of 10 Americans say they do not want a data center in their backyard, and that resistance helped delay or cancel at least 75 projects in the first quarter of 2026 alone.

That pushback is pushing companies to find power that does not lean on the existing grid. Reactors like Ward 250 could, in principle, supply electricity directly to AI sites without adding strain to national or local networks. Water is the other half of the pitch. Amazon, Microsoft, and Nvidia are also working on approaches meant to cut data center water use by as much as 100%.

Big AI players have been circling nuclear for a while. Amazon, Google, Microsoft, Nvidia, and Oracle all began investing in nuclear technologies as early as 2024, betting that AI data centers would need enormous amounts of power.

Read the claims carefully

Valar Atomics says it is the first startup to achieve power production. That claim deserves context. The Department of Energy notes that two other firms, Deployable Energy with its Unity reactor and Antares Nuclear with its Mark-0, have also achieved criticality. Criticality means a reactor has reached a self-sustaining chain reaction, an early step toward generating electricity. In other words, several startups are moving in the same direction, and the exact order of milestones is contested.

Scale is worth keeping in perspective too. The on-stage demonstration involved 100 kilowatts of thermal energy powering one chip. The proposed AI factory is 30 megawatts. That is a large jump from a single desktop to a facility, and the source describes the factory as a plan rather than a finished build.

What's next

The immediate test is whether Valar Atomics and Nvidia can move from a stage demonstration to a working 30-megawatt facility that actually runs without tapping local water. If closed-loop, reactor-powered AI sites prove practical, they could reshape where and how data centers get built, especially in communities that have started saying no.

For now, the useful signal is not the spectacle of a PC running on nuclear power. It is that grid strain and water use have become real obstacles to AI expansion, and companies are now treating on-site energy as part of the hardware problem, not an afterthought.