Data centers go nuclear for power-hungry AI workloads

AWS is putting its money into yet another SMR from X-energy, which also has developed TRISO-X, a custom version of a U.S. Department of Energy endorsed fuel, TRISO (TRi-structural ISOtropic particle). AWS has signed an agreement with Energy Northwest, which will construct, own, and operate an installation using the X-energy SMRs, to fund the feasibility stage of the project. It has also signed a memorandum of understanding with Dominion Energy to explore the use of SMRs in Virginia.

And yet another SMR vendor, NuScale—the only one so far with a design approved by the U.S. Nuclear Regulatory Commission (NRC), as it happens—uses pressurized water cooling. Its largest model can generate 77MWe per module, for a total of 924MWe, and can go without refueling for up to 21 months.

Data center colocation

Not all data centers are embracing SMRs, though. AWS, Meta, and Microsoft are all looking at colocation with standard nuclear power plants.

Colocation, in this context, means that the data center is not only close to the power plant, but also it receives its electricity directly, bypassing the electric grid. It’s a win-win situation for the co-located customer and the operator; the customer gets a long-term commitment for a supply of the power it needs, and the power operator has a known source of revenue.

Microsoft, for example, has made a 20-year power purchase agreement (PPA) with Constellation to purchase power from the currently decommissioned Unit 1 at the Three Mile Island nuclear facility, assuming Constellation can leap the many regulatory hurdles and revive it. Constellation plans to spend $1.6 billion to revamp and update the plant, to be renamed the Crane Clean Energy Center (CCEC).

“Restarting a nuclear reactor requires U.S. Nuclear Regulatory Commission approval following a comprehensive safety and environmental review, as well as permits from relevant state and local agencies,” Constellation said in a release. “Additionally, through a separate request, Constellation will pursue license renewal that will extend plant operations to at least 2054. The CCEC is expected to be online in 2028.”