Small But Mighty

Micro nuclear reactors will power the future. These are the top companies making them.

Big tech has big energy demands and ambitious energy goals. And, quite frankly, so do the rest of us. To power AI and keep electricity costs and emissions down, the Magnificent Seven tech companies and others are turning to a small, but powerful, solution. Micro nuclear reactors provide a significant punch – enough to power a data center or an industrial complex – without the long construction timeline to come online that comes with larger nuclear reactors that can power entire cities. Micro nuclear reactors have momentum, and they have policy on their side, with the U.S. Army’s Janus Program launched last year with the goal a reactor operating at a domestic military installation no later than Sept. 30, 2028. Several key players are at various stages of readiness to bring micro nuclear reactors online.

Tier 1: Closest to Deployment & Commercial Execution

Last Energy

In an effort to build a world with nuclear energy in the mix, Last Energy is building a mini version of its large-scale reactor for a project at Texas A&M’s Rellis innovation and tech campus. The PWR-5 microreactor will provide 5 megawatts of power to demonstrate safe, low-power criticality, and eventually hook onto the grid.

“We’re partnering with Texas A&M to usher in the next Atomic Era,” Last Energy founder and CEO Bret Kugelmass said. “With fuel in hand, an optimal site at RELLIS, and DOE authorisation underway, we have the ideal conditions to demonstrate a standardised, scalable microreactor product in the United States.”

• Why it ranks here: With private capital and U.S. Department of Energy backing, the PWR-5 is fully financed and could go critical in the next few months.

BWXT

The company that powers the U.S. Navy’s submarine and aircraft carrier fleet has struck a memorandum of understanding with Purdue University to conduct research on next-generation nuclear manufacturing, including small modular reactors and microreactors. PUR-1, the first nuclear reactor in the U.S. to be controlled and operated digitally, is at the center of the partnership and the key to developing even more advanced reactors.

“By aligning our nationally recognized engineering programs with cutting-edge nuclear technologies, like small modular reactors, we’re not only advancing research — we’re also preparing the next generation of scientists, engineers and policy leaders to meet the energy and workforce demands of tomorrow,” Purdue President Mung Chiang said.

• Why it ranks here: BWXT has a strong track record as the sole provider of nuclear fuel and components for U.S. Navy submarines and aircraft carriers, and PUR-1 is a unique reactor to base research on.

Westinghouse Electric Co.

Westinghouse has been powering America for 140 years, and it’s been in the nuclear game since the 1937 introduction of the Atom Smasher. Far from resting on its laurels, Westinghouse Nuclear has been busy lately, signing agreements with Tetra Tech Canada, Nordion, PSEG, and Nuclear Transport Solutions in the last few months to deploy the AP1000 and AP300 reactors in Ontario, produce Cobalt-60, and safely transport nuclear fuel, respectively. And they’re just getting started.

“We are targeting deployment of multiple eVinci microreactors across the world by the end of the decade, and the strong and continued partnership with NRIC, INL, and the Department of Energy is instrumental to our efforts,” Jon Ball, president of eVinci Technologies at Westinghouse, said.

• Why it ranks here: eVinci can produce 5MWe with a 15MWth core design. The reactor core is designed to run for eight or more full-power years before refueling.

Tier 2: Advanced, Well-Funded, Longer Timelines

X-energy

Already designing the SMRs for the Cascade Advanced Energy Facility in Washington state, X-energy now has a 10-year deal with SGL Carbon LLC to produce graphite reactor components for the 320 MW power station. In partnership with Amazon and Energy Northwest, X-energy will provide four Xe-100 SMRs to power the project, which could grow to 960 MW and provide energy to the local grid.

“Scaling new nuclear requires partners who know how to execute and have done so time and again in the world’s most demanding industries,” X-energy CEO J. Clay Sell said.

• Why it ranks here: The Cascade Advanced Energy Facility is scheduled to break ground in 2030, and having a powerful partner like Amazon gives X-energy a leg up in the race to stand out.

Kairos Power

Google has teamed with Kairos on a Master Plant Development Agreement, with the latter developing, constructing, and operating a series of advanced reactor plants to help the tech giant get to net zero emissions.

“This early commitment from Google provides a strong customer demand signal, which reinforces Kairos Power’s continued investment in our iterative development approach and commercial production scale-up,” Kairos Power VP Jeff Olson said.

Why it ranks here: The agreement calls for Kairos to bring a first SMR online by 2030, with more coming through 2035. In total, about 500 MW of nuclear energy would be added to U.S. grids.

Oklo

In another tech giant deal, Oklo plans to develop a 1.2 GW campus in Ohio to support Meta data centers in the area. Oklo’s business model allows large energy users to fund their own generation and add new clean power to the grid.

“Two years ago, Oklo shared its vision to build a new generation of advanced reactors in Ohio. Today, that vision is becoming a reality.” Jacob DeWitte, Oklo’s co-founder and CEO, said. “Meta’s funding commitment in support of early procurement and development activity is a major step in moving advanced nuclear forward.”

Why it ranks here: The agreement with Meta immediately turned Oklo stock into a hot buy, and its business model can help big energy users make good neighbors by having them pay for their generation and give back to the grid.

Tier 3: Strategic Adjacent & International Players

Rolls-Royce

The nuclear energy pioneer is helping the UK Space Agency research how nuclear energy could power a base on the moon. Nuclear power could extend the length of lunar missions and increase their scientific value, says Rolls-Royce, which has set a goal of having a reactor ready to send to the moon by 2029. It has £2.9 million ($3.6 million) in funding to work with.

“This funding will bring us further down the road in making the Micro-Reactor a reality, with the technology bringing immense benefits for both space and Earth. The technology will deliver the capability to support commercial and defense use cases alongside providing a solution to decarbonize industry and provide clean, safe, and reliable energy,” Abi Clayton, Rolls-Royce director of future programs, said.

• Why it ranks here: Artemis II marks the first human visit to the moon in over 50 years, but there isn’t scheduled to be another moon landing until 2027 at the earliest. Still, increased lunar activity is a goal for many space agencies in the near future. Rolls-Royce micro nuclear reactor could power it.

TerraPower

Backed by an investment of more than $1 billion by Bill Gates, TerraPower is working with Warren Buffett-backed utility PacfiCorp to develop more SMRs. It’s also undertaking a Natrium clean energy reactor demonstration project at a retiring coal plant in Wyoming.

“We just keep proving that we’re the leading nuclear project in the U.S.,” TerraPower CEO Chris Levesque told GeekWire. “We plan to build hundreds of Natrium reactors. We’re very focused on delivering the first one on time.”

Why it ranks here: TerraPower has MOUs with government agencies in several states to explore sitings of Natrium reactors and inked its own deal with Meta for eight advanced reactors, with the first two coming online in 2032.