Parsons, Kansas, will be the site of a California startup’s first ever 1-mile-deep nuclear reactor — with support from county commissioners, both Republican Kansas U.S. senators and Democratic Gov. Laura Kelly’s administration.

Deep Fission will hold a ceremonial groundbreaking on Tuesday at Great Plains Industrial Park. Company leaders hope to receive U.S. Department of Energy authorization and get its nuclear reactor up and running by next Fourth of July.

The company is part of a presidential pilot program that aims to demonstrate new reactors by then. After that, Deep Fission hopes to pursue commercial operations.

“The industrial park is looking to bring in, to attract industry and possibly data centers or other large uses of electricity,” Deep Fission CEO Liz Muller said in an interview with the Kansas News Service. “But in order to attract them, it needs to have a source of electricity.”

Deep Fission is an advanced nuclear company founded in 2023 that promises to place small nuclear reactors at the bottom of 30-inch wide, mile-deep boreholes.

In Kansas, a standard nuclear power plant proposal from an electricity company would need to pass through the agency that regulates utilities — the Kansas Corporation Commission — for a siting permit and public hearings, among other steps. However, the KCC said it doesn’t have enough information yet to know the full extent of its jurisdiction over Deep Fission’s project. For example, it remains to be seen whether the company will fall under laws that apply to electric utilities.

“The nature of Deep Fission’s operations will determine whether it qualifies as an electric utility,” the KCC said in a recent email.

Deep Fission’s letter of intent with the industrial park ultimately envisions a full-scale commercial project.

Parsons offers the opportunity to “potentially grow with the Park for decades to come,” the company said in a press release.

This would mean installing more nuclear reactors over the years, since Deep Fission designs its reactors to generate power for two to seven years.

Muller said the design is safe.

“All of the radioactivity stays at the bottom of the borehole a mile underground,” she said. “The only thing that is coming up through the borehole is clean, fresh water. We feel really good about our ability to protect both humans and the environment.”

That water comes up in the form of steam for turning a turbine to generate electricity, then cools and goes back down into the borehole.

Elected officials welcome Deep Fission to Parsons

Parsons, a city near the Oklahoma and Missouri borders, has a population of about 10,000. The Great Plains Industrial Park on the east side of Parsons covers 14,000 acres and is the former site of the Kansas Army Ammunition Plant.

Deep Fission’s press release includes enthusiastic quotes from a host of local, state and congressional voices.

“Kansas has long been a leader in energy production, and we’re continuing to diversify our portfolio with innovative technologies such as advanced nuclear,” Kansas Lt. Gov. and Secretary of Commerce David Toland said.

Toland said the Kansas Department of Commerce “will support (Deep Fission’s) efforts to integrate a thoughtful and transparent community engagement process that gives local residents clear avenues to ask questions and be part of the conversation.”

Republican Sens. Roger Marshall and Jerry Moran hailed the project.

“As our nation’s demand for reliable, around-the-clock energy continues to grow, advanced nuclear technology will play a critical role,” Marshall said. “It’s exciting to see cutting-edge innovation and high-quality energy investment come to Kansas.”

Robert Wood, chairman of the Great Plains Development Authority that owns the industrial park, said Deep Fission’s project is “showcasing Kansas’s potential to the world.”

“The Board and I look forward to building a long-term relationship with Deep Fission and the positive impacts this collaboration will bring,” Wood said.

County commissioners also touted economic development.

“We are committed to backing projects that provide jobs, energy, and economic growth for the citizens of Labette County,” the County Commission said.

Deep Fission melds nuclear, geothermal and oil industry technology

Muller entered the nuclear industry with her father, University of California Berkeley professor emeritus of physics Rich Muller. They wanted to solve two of the nuclear industry’s problems: nuclear waste and the high cost of nuclear power.

So the duo created two companies: Deep Isolation and Deep Fission.

The first company proposes solving nuclear waste disposal by drilling boreholes 1 mile deep and putting the waste at the bottom. The second company plans to make nuclear power much cheaper by drilling equally deep boreholes and putting reactors into them.

Deep Isolation is currently conducting tests. Deep Fission has signed letters of intent for sites in Kansas, Texas and Utah.

In August, Deep Fission’s reactor design became one of 11 projects picked for President Donald Trump’s nuclear pilot program, which offers to expedite testing of new designs and ultimately fast-track them to commercial licensing.

The federal program’s target is to get at least three nuclear reactors operating at a state of steady fission before next Fourth of July.

Deep Fission’s design will use a pressurized water reactor — the world’s most common kind of nuclear technology — small enough to fit into the borehole and powerful enough to generate about as much power as 10,000 homes consume, Muller said.

Deep Fission will then fill the borehole with water. The reactor at the bottom will transfer heat to water that will rise to the surface, become steam and turn turbines.

The steam will then cool down and return to the borehole, so that the same water is constantly reused.

The idea borrows technology and concepts from the geothermal and oil and gas industries, Muller said. Borehole drilling is standard practice for oil and gas. And geothermal power uses hot water that rises up a borehole, turns a turbine and is then reused.

A Deep Fission reactor will churn out power for two to seven years, depending on its design, Muller said. Afterward, the company could seal the reactor and leave it there. Or, if the U.S. develops a site for nuclear waste disposal, it could remove the reactor and send the waste there.

Deep Fission also said that once a reactor is spent, it could seal that one off and stack new ones on top of it, as long as the borehole was originally drilled deeper than 1 mile so that the uppermost reactor remains at least 1 mile deep.

This would make maximum use of a single borehole.

“We can keep doing that: seal it off, add another one on top,” she said. “And so if (one reactor) lasts seven years and you do seven of those cycles, that’s 49 years.”

Does the public get a say about Deep Fission’s plans?

Deep Fission said it considers community input critical.

“We have already had a significant amount of engagement with the community,” Muller said. “ We’ve done conversations with the government — local government, state government. We’ve had a number of stakeholder groups.”

Muller didn’t elaborate further on the stakeholders who have provided input and she didn’t indicate when the company plans to hold any public meetings that would allow the broader community to weigh in.

But she signaled that her company’s vision includes such meetings.

Asked whether the public’s input would have any influence, since Deep Fission has already selected a site and set a demonstration deadline of July 4, 2026, Muller said the company will want ongoing engagement on steps such as commercialization.

“There’s going to be lots of opportunities to participate, to be heard, to ask questions,” she said. “Starting immediately, but continuing on for years to come.”

State and federal oversight of nuclear energy

The extent to which Kansas energy regulators would oversee Deep Fission’s activities remains partly unclear. The KCC is in the early stages of communication with the company.

“The KCC is generally aware of Deep Fission and its intent to pursue a demonstration project” in Kansas, KCC staff said in an email last month. “Our agency has only had introductory meetings with the company.”

The KCC could conceivably regulate an underground nuclear reactor for a few reasons.

First, the commission regulates drilling and operations related to certain wells.

Second, the commission oversees public utilities, with a mission of keeping utilities reliable and reasonably priced.

If a public utility wants to build a new power plant, it has to file a proposal with the KCC. This can trigger public hearings on how the plant would impact other customers and what they pay for electricity.

Also, an electric utility that wants to build a nuclear plant needs a siting permit from the KCC. Getting that permit requires going through a public hearing.

Of these two spheres of regulation — oversight of wells and of public utilities — KCC jurisdiction is clearer in the first than the second.

The KCC said Deep Fission will have to first drill a pilot hole – which will help determine if the site is suitable. For the pilot hole, the company will need to seek a drilling license and permit from the KCC and provide financial assurance related to the pilot hole.

“Beyond that initial pilot hole, the KCC would not have jurisdiction over a nuclear reactor well,” the KCC said.

In the case of public utility regulation, the KCC said it needs more information to know its full jurisdiction.

“For example, Kansas law only requires ‘electric utilities’ to obtain a siting permit from the KCC for nuclear generation facilities,” the agency said, and it remains to be seen if Deep Fission fits that definition.

If Deep Fission does fall under that rule, it would have to file details to the KCC about its nuclear plans, including about the construction, operation and maintenance.

As for commercializing the project, Deep Fission’s long-term goal after demonstrating its technology, KCC said that state law doesn’t allow Deep Fission to sell electricity at retail without partnering with a regulated utility, which would trigger KCC oversight.

The rule wouldn’t apply if Deep Fission sells wholesale, the KCC said.

Apart from potential state regulation, Deep Fission’s project will fall under oversight from federal authorities such as the Nuclear Regulatory Commission.

The Trump administration is working to overhaul federal nuclear oversight, which it argues is overly burdensome and risk avoidant.

“Instead of efficiently promoting safe, abundant nuclear energy,” one of Trump’s executive orders said, “the NRC has instead tried to insulate Americans from the most remote risks without appropriate regard for the severe domestic and geopolitical costs of such risk aversion.”

Earlier this year, the administration unveiled executive orders and plans to press for approval of projects, rewrite regulations and use the controversial Department of Government Efficiency to shrink the Nuclear Regulatory Commission and focus on “expeditious processing of license applications and the adoption of innovative technology.”

Are there risks to groundwater or other environmental concerns?

The Kansas News Service asked whether state agencies would play any role in checking if Deep Fission’s chosen drilling site would pose any problem for water supplies or face any risk from earthquakes.

The KCC said it’s possible that the Kansas Department of Health and Environment will have a regulatory role and that collaboration with the Kansas Geological Survey (which houses expertise on groundwater, earthquakes and oil and gas wells) is also likely.

The Kansas News Service asked KDHE questions last month, including whether it would play any part in checking whether Deep Fission’s plans are safe for groundwater or other environmental implications. The agency didn’t respond and neither did the governor’s Office.

Deep Fission said its project poses no threat to groundwater.

“We know how to protect the water table,” Muller said, adding that the reactor would be about 1 mile below groundwater.

“It’s a full mile of rock. Billions of tons of rock,” she said.

As for keeping the water in the borehole secure, Muller said the company would use secure casing methods already used in the oil and gas industry.

Deep Fission’s partnership with waterless data centers

Separately from its plans in Parsons, Deep Fission is making inroads with the kind of data center companies that its federal financial filings indicate are its initial target market.

The company has a partnership with Endeavour, the parent company of Edged waterless data centers that have opened in Kansas City, Dallas, Atlanta, Chicago, Columbus, Des Moines and Phoenix — as well as Spain and Portugal.

The Edged data centers are designed to cool servers without water. Heavy water use for cooling is considered a top environmental concern related to the fast global increase in data centers.

In a federal filing, Deep Fission said its partnership with Endeavour should help it get a head start in the data center power segment.

“Even under conservative assumptions — such as 6% annual growth in data center demand, resulting in a doubling of consumption by 2035 — capturing just a percentage of incremental demand would represent a significant growth driver,” the company wrote.

Tech companies are building data centers at a furious pace in part because of the rapid rise of artificial intelligence.

In October, Deep Fission announced that it has so far inked letters of intent with “data centers, co-developers, industrial parks and strategic partners” that would entail generating 12.5 gigawatts of power.

Celia Llopis-Jepsen is the environment reporter for the Kansas News Service and host of the environmental podcast Up From Dust. You can follow her on Bluesky or email her at celia (at) kcur (dot) org.