With federal funding windfall, X-energy advances small nuclear reactor

The U.S. Department of Energy is putting another $1 billion into X-energy, an Amazon-backed nuclear startup, on top of the $1.2 billion it committed back in 2021. The money is meant to help build small, next-generation nuclear reactors called Xe-100s. The first four are planned at a Dow Chemical plant in Seadrift, Texas, and could come online in the early 2030s. Across deals with Dow, Amazon, and a UK energy company, X-energy has commitments for as many as 144 of these reactors worldwide, though most are still years from breaking ground.

The Xe-100 works differently from traditional reactors: it uses graphite instead of water to control the nuclear reaction and helium gas to move heat, plus a specialized, heat-resistant fuel. That design suits industrial sites needing both heat and power, but it's unproven at commercial scale, and costs remain uncertain. X-energy hasn't updated its 2023 cost estimate of $4.75 billion to $5.75 billion, though the new federal funding suggests spending of at least $4.2 billion. The company still needs a construction permit from the Nuclear Regulatory Commission, expected in early 2027, and Dow won't decide whether to actually build the Seadrift plant until 2028 at the earliest.

None of this involves home energy upgrades or rebates directly. It's a look at where federal nuclear investment is heading as the U.S. tries to expand carbon-free power for industry and, increasingly, the data centers behind companies like Amazon.