Google will back the construction of seven small modular nuclear reactors (SMRs) from Kairos Power, becoming the first tech company to commission new nuclear power plants to provide low-carbon electricity for its energy-hungry data centres.

Google and Kairos said on Monday (14 October) that under the terms of the deal, the first of its kind, Google committed to buying power generated by seven reactors to be built by Kairos Power, a seven-year-old California-based startup.

The agreement targets adding 500 MW of nuclear power starting at the end of the decade, the companies said. The first reactor could be online by 2030 and additional reactors by 2035.

Google said that buying power from multiple SMRs sends an “important demand signal to the market”, while making a long-term investment to accelerate commercialisation.

“We believe that nuclear energy has a critical role to play in supporting our clean growth and helping to deliver on the progress of AI,” said Michael Terrell, senior director for energy and climate at Google.

“The grid needs these kinds of clean, reliable sources of energy that can support the build out of these technologies… We feel like nuclear can play an important role in helping to meet our demand, and helping meet our demand cleanly, in a way that’s more around the clock.

“The end goal here is 24/7, carbon-free energy,” said Terrell. “We feel like in order to meet goals around round-the-clock clean energy, you’re going to need to have technologies that complement wind and solar and lithium-ion storage.”

The company did not disclose the financial terms of the deal.

The 500 MW of generation that would be built by Kairos for Google is about enough to power a midsize city – or one AI data centre campus.

The project site – or whether there could be reactors at multiple locations –has not been determined, the companies said.

Google would have data centres somewhere in the region near the Kairos reactors, but it has not been determined whether they would receive power directly from the nuclear plants or from the grid. Google could count the addition of nuclear power toward meeting its carbon-reduction commitments.

The units for Google will include a single 50-MW reactor, with three subsequent power plants that would each have two 75-MW reactors, Kairos said. That compares with about 1,000 MW at reactors at conventional nuclear power plants.

Background: Work Has Begun On Demonstration Unit

Kairos will have to navigate complex approvals through the US Nuclear Regulatory Commission (NRC), but already has clearance to build a demonstration reactor in Tennessee, which could start operating in 2027.

The Hermes Low-Power Demonstration Reactor, which could be operational in 2027, is the first and only Generation IV* reactor to be approved for construction by the NRC and the first non-light-water reactor to be permitted in the US in over 50 years.

Hermes is a non-power version of Kairos Power’s fluoride salt-cooled high temperature reactor, the KP-HFR.

Kairos has also begun construction on a new reactor-grade salt production facility at its manufacturing development campus in Albuquerque, New Mexico.

Mike Laufer, chief executive and co-founder at Kairos, said the demonstration project and the Albuquerque plant are helping the company avoid spiraling costs, a pitfall of the conventional nuclear industry.

Tech companies are increasingly interested in nuclear as a medium-term solution to providing low-carbon electricity to meet their data centres’ energy demands.

Last month, Microsoft announced that it would commit to buying 20 years’ supply of electricity from the mothballed US nuclear power plant Three Mile Island if Constellation Energy restarted the site.

In March, Amazon Web Services, a subsidiary of the online retail giant founded by Jeff Bezos, acquired US power producer Talen Energy’s Cumulus data centre campus at the Susquehanna nuclear power station in Pennsylvania.

US computer technology company Oracle wants to power a new data centre through nuclear energy, according to the firm’s chief technology officer Larry Ellison.

Speaking during a recent earnings call, Ellison confirmed the cloud computing giant has “already got building permits” for three SMRs, without giving details.

Kairos Power: The Reactor Technology

Kairos Power’s technology uses a molten-salt cooling system, combined with a ceramic, pebble-type fuel, to efficiently transport heat to a steam turbine to generate power. This passively safe system allows the reactor to operate at low pressure, enabling a simpler more affordable nuclear reactor design.

Instead of water, which is used in traditional reactors, Kairos uses molten fluoride salt as a coolant.

The molten salts transfer heat away from the reactor core. The heat can then be used either to produce electricity or for industrial processes such as oil refining, desalination, and steel production.

These reactors have several inherent safety advantages. The first, and possibly the most important, is that the reactor is operated at low pressure because the coolants never approach boiling point. Even in an accident, there would be no force expelling materials from the reactor, and no high-pressure containment system would be required to prevent such a release.

The plant will use Triso coated particle fuel. Triso – or “tristructural-isotropic” – fuel particles contain a spherical kernel of enriched uranium oxycarbide surrounded by layers of carbon and silicon carbide, which contains fission products.

According to the US Department of Energy, Triso is essentially a “robust, microencapsulated fuel form” developed originally in the 1950s.

Perhaps Triso’s biggest benefit is that each particle acts “as its own containment system thanks to its triple-coated layers,” the DOE said. This allows them to retain fission products under all reactor conditions.

• No precise definition of a Generation IV reactor exists, but the term is used to refer to nuclear reactor technologies under development including gas-cooled fast reactors, lead-cooled fast reactors, molten salt reactors, sodium-cooled fast reactors, supercritical-water-cooled reactors and very high-temperature reactors. An international task force, the Generation IV International Forum (GIF), is sharing R&D to develop six Generation IV nuclear reactor technologies. GIF said goals of Generation IV reactor design include lower cost and financial risk, minimising nuclear waste and high levels of safety and reliability.