The Real Obstacle to Nuclear Power

It’s not environmentalists—it’s the nuclear-power industry itself.

Photographs of two people in hard hats working on a test nuclear unit
John Muratore and Troy Price work on a test unit at Kairos Power. The company is trying to build a new kind of nuclear plant. (Brian Finke for The Atlantic)

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Kairos Power’s new test facility is on a parched site a few miles south of the Albuquerque, New Mexico, airport. Around it, desert stretches toward hazy mountains on the horizon. The building looks like a factory or a warehouse; nothing about it betrays the moonshot exercise happening within. There, digital readouts count down the minutes, T-minus style, until power begins flowing to a test unit simulating the blistering heat of a new kind of nuclear reactor. In this test run, electricity, not uranium, will furnish the energy; graphite-encased fuel pebbles, each about the size of a golf ball, will be dummies containing no radioactive material. But everything else will be true to life, including the molten fluoride salt that will flow through the device to cool it. If all goes according to plan, the system—never tried before—will control and regulate a simulated chain reaction. When I glance at a countdown clock behind the receptionist during a visit last May, it says 31 days, 8 hours, 9 minutes, and 22 seconds until the experiment begins.

The test unit looks surprisingly unimpressive: a shiny cylindrical drum only about 16 feet tall, resembling an oversize water heater. The scale is unlike that of an existing commercial nuclear plant. Forget about those airport-scale compounds with their fortresslike containment enclosures and 40-story cooling towers belching steam. This reactor will sit in an ordinary building the size of, say, a suburban self-storage facility. It will be made in factories for easy shipping and rapid assembly. Customers will be able to buy just one, to power a chemical or steel plant, or a few, linked like batteries, to power a city. Most important, even if a local disaster cuts the power to the cooling system and safety systems fail, this reactor will not melt down, spew radioactive material, or become too hot and dangerous to approach. It will remain stable until normal conditions are restored.

Small and safe is the vision, at least. Dozens of companies and labs in the U.S. and abroad are pursuing it. Kairos is well along, with a permit to build a full-fledged nuclear test reactor already moving toward federal approval, hopefully by the end of 2023. That test will depend on this one in Albuquerque, because molten-salt reactor cooling has not been tried in the United States since the 1960s, when a five-year experiment at the Oak Ridge National Laboratory, in Tennessee, proved the idea viable. In a few days, the test unit’s top will be installed, crowning the device with bristling pipes and sensors. Nearby, welders ready those pipes and valves. Engineers stand on top of scaffolding slotting graphite reflectors into place.

As I tour the facility, however, I soon realize that the crucial technology is not 16 feet tall but about 5 foot 6, balding, with jeans and thick, black-framed glasses. John Muratore runs this test operation and, as you would expect, is an experienced engineer; as you might not expect, he is a space engineer, not a nuclear one. As a boy in the ’60s, he was the archetypal kid who built model planes and joined the rocketry club and never stopped daydreaming about human flight. He spent 24 years working for NASA, where he was a flight controller for the space-shuttle program under the legendary flight director Gene Kranz, of Apollo 13 movie fame. Then he spent a decade working for SpaceX, Elon Musk’s world-beating private spaceflight company. Nuclear power wasn’t on his radar until recently, when Kairos’s executives called him for advice and wound up recruiting him. “A lot of it was the same,” he told me. “A launchpad and a nuclear reactor have a lot in common”—extreme temperatures, and many tons of concrete, and lots of pipes and valves and sensors and controls that must work together with extreme precision.

There’s another, more significant similarity: “The industry is hobbled by costs and schedule overruns, as was the launch industry prior to SpaceX.” Managing complex projects—and bringing new vigor to old ideas—is something Muratore’s 40 years in the space industry have taught him a lot about.

Nuclear power is in a strange position today. Those who worry about climate change have come to see that it is essential. The warming clock is ticking—another sort of countdown—and replacing fossil fuels is much easier with nuclear power in the equation. And yet the industry, in many respects, looks unready to step into a major role. It has consistently flopped as a commercial proposition. Decade after decade, it has broken its promises to deliver new plants on budget and on time, and, despite an enviable safety record, it has failed to put to rest the public’s fear of catastrophic accidents. Many of the industry’s best minds know they need a new approach, and soon. For inspiration, some have turned toward SpaceX, Tesla, and Apple.

Worker with Miliing Machine inside of the Kairos Power Pland
Michael Thomas, a Kairos machinist, loads a part into a milling machine for modifications. (Brian Finke for The Atlantic)

“Yeah, we were a bit crazy to try to do this,” Per Peterson, Kairos’s co-founder and chief nuclear officer, told me when I asked about starting a company from scratch and setting out to make the nuclear industry agile and competitive. “But I don’t remember ever lacking the confidence that it was feasible for us to do what we wanted to do.” The fate of the industry, and in some measure the planet, depends on whether he and like-minded entrepreneurs can finally keep their promises.


When I started reporting this article, I imagined it might be a diatribe against the environmental movement’s resistance to nuclear power. For a generation or more, the United States has been fighting climate change—and all the other ills that result from fossil fuels—with one hand tied behind its back. Bruce Babbitt, a former secretary of the interior and governor of Arizona, was on a presidential commission to evaluate nuclear power after the Three Mile Island plant’s partial meltdown in 1979, the U.S. industry’s worst accident. Though no one died or was even injured—and the accident led to new protocols and training under which the plant’s second, intact reactor operated uneventfully until 2019—the accident hardened the public and environmentalists against nuclear energy. After that, as Babbitt told me, “opposition in the environmental community was near unanimous. The position was ‘No new nuclear plants, and we should phase out the existing nuclear base.’ ” Which was the road the U.S. took. Today legacy nuclear power supplies about 20 percent of American electricity, but the country has fired up only one new power reactor since 1996.

From an environmental point of view, this seems like a perverse strategy, because nuclear power, as most people know, is carbon-free—and is also, as fewer people realize, fantastically safe. Only the 1986 accident at Chernobyl, in Ukraine, has caused mass fatalities from radioactivity, and the plant there was subpar and mismanaged, by Western standards. Excluding Chernobyl, the total number of deaths attributed to a radiation accident at a commercial nuclear-power plant is zero or one, depending on your interpretation of Japan’s 2011 Fukushima accident. The Fukushima evacuation certainly caused deaths; Japanese authorities have estimated that more than 2,000 people may have died from disruptions in services such as nursing care and from stress-related factors such as alcoholism and depression. (Some experts now believe that the evacuation was far too large.) Even so, Japan’s decision to shut down its nuclear plants has been estimated to cause multiples of that death toll, on account of the increased fossil-fuel pollution that followed.

The real challenge with giant nuclear plants like Fukushima and Three Mile Island is not making them safe but doing so at a reasonable price, which is the problem that companies like Kairos are trying to solve. But even people who feel scared of nuclear power do not dispute that fossil fuels are orders of magnitude more dangerous. One study, published in 2021, estimated that air pollution from fossil fuels killed about 1 million people in 2017 alone. In fact, nuclear power’s safety record to date is easily on par with the wind and solar industries, because wind turbines and rooftop panels create minor risks such as falls and fire. As for nuclear waste, it has turned out to be a surprisingly manageable problem, partly because there isn’t much of it; all of the spent fuel the U.S. nuclear industry has ever created could be buried under a single football field to a depth of less than 10 yards, according to the Department of Energy. Unlike coal waste, which is of course spewed into the air we breathe, radioactive waste is stored in carefully monitored casks.

And so environmentalists, I thought, were betraying the environment by stigmatizing nuclear power. But I had to revise my view. Even without green opposition, nuclear power as we knew it would have fizzled—today’s environmentalists are not the main obstacle to its wide adoption.

To be sure, environmentalists do not love nuclear power. They much prefer solar and wind. But as Babbitt told me, “They’re all coming around. The attitudes in the environmental community are perceptibly changing.” Although only a handful of the mainline environmental organizations are openly “nuclear inclusive” (for example, the Nature Conservancy), many quietly accept that nuclear power can be part of the climate solution, and perhaps a necessary part.

Because solar and wind power are inherently intermittent, they require other energy sources to even out peaks and dips. Natural gas and coal can do that, but of course the goal is to retire them. Batteries can help but are much too expensive to rely on at present, and mining, manufacturing, and disposing of them entail their own environmental harms. Also, nuclear power is the only efficient way to provide zero-carbon heat for high-temperature industrial processes such as steelmaking, which account for about a fifth of energy consumption.

Perhaps most important, adding solar and wind capacity becomes more expensive and controversial as the most accessible land is used up. Nuclear energy’s footprint is extremely small. Solar-energy production uses dozens of times as much land per unit of energy produced; wind uses much more land than that. According to congressional testimony by Armond Cohen of the Clean Air Task Force, meeting all of the eastern United States’ energy needs might require 100,000 square miles of solar panels (an area greater than New England) or more than 800,000 square miles of onshore windmills (Alaska plus California), versus only a bit over 500 square miles of nuclear plants (the city of Phoenix, Arizona). Given the amount of real estate that solar and wind farms usurp, efforts to place them are running into entirely predictable local resistance, which will only increase as the easiest and cheapest sites are picked off.

Finally, as low- and middle-income countries develop over the next several decades, they will almost double the world’s demand for electricity. Total global energy consumption will rise by 30 percent by 2050, according to the International Energy Agency. Meeting this challenge while reducing carbon emissions will be much harder, if not impossible, without a nuclear assist.

Left: Javier Talamantes, a Kairos technologist, installs one of the thousands of sensors that feed data
to the test unit. Right: A sensor monitors environmental oxygen levels to ensure the safety of personnel working on the unit. (Brian Finke for The Atlantic)

Recognizing as much, three consecutive administrations—Barack Obama’s, Donald Trump’s, and now Joe Biden’s—have included next-generation nuclear power in their policy agenda. Both parties in Congress support federal R&D funding, which has run into the billions in the past few years. Two-thirds of the states have told the Associated Press they want to include nuclear power in their green-energy plans. “Today the topic of new nuclear is front of mind for all our member utilities,” says Doug True, a senior vice president and the chief nuclear officer of the Nuclear Energy Institute, an industry trade group. “We have states saying, ‘Why can’t you build us a nuclear plant?’ ”

Thanks to those developments, the table is set for nuclear power in a way that has not been true for two generations. So what is the main problem for the nuclear-power industry? In sum: the nuclear-power industry.


The U.S. has two big commercial reactors under construction, both at the same site in Georgia. The licensing process for them began in 2008; construction began in 2012, with a projected price of $14 billion and start-up planned for 2017 at the latest. As of February 2022, the projected cost had mushroomed to $30 billion, and the reactors still aren’t open. (Hopefully in 2023, the sponsoring utility says.)

No one who knows the industry is surprised. In the United States, construction delays on the Georgia reactors and others drove Westinghouse, the company building them, into bankruptcy. France started building a new reactor at its Flamanville plant in 2007, planning to open it in five years; as of this writing, it is still not ready. Britain approved a major plant in 2008 and probably won’t turn it on until 2027, and the project is 50 percent over budget. Delays and cost overruns are so routine that they are simply assumed. “Nuclear as it exists today,” Mike Laufer, a co-founder and the CEO of Kairos Power, told me, “is clean, it’s reliable, it’s safe. But it’s not affordable”—at least when it comes to building new plants—“and this is what’s holding nuclear back from a much bigger role in fighting climate change.”

Industry veterans recall the 1950s and ’60s as a time of new ideas and experimentation in nuclear power. For scientists and engineers, the atom had the same kind of romantic, adventurous appeal as the space program. In 1968, a company called General Atomics got a license to build a gas-cooled reactor in Colorado, a new design and potentially the start of a new era. Instead, it proved to be the industry’s last stab at fundamental innovation. Thanks to incremental upgrades, today’s legacy nuclear plants cost almost 40 percent less to run than they did in 2012, according to the Nuclear Energy Institute, but if you had fallen asleep in the ’70s and awakened today, you would recognize the basic nuclear-power model as the same, both technologically and as a business proposition.

In particular, you would see the same gigantic plants and staggering building costs. In the 1970s, the industry stopped pursuing alternatives to using water to cool the hot nuclear core and transfer heat to steam turbines generating electricity. Water worked fine, but it had to be held under extreme pressure to stay fluid at fission temperatures, and if it boiled off, meltdowns were an inherent risk. Accidents could be reliably prevented, but only by building in elaborate safety measures, all of which necessitated costly engineering and heavy regulatory oversight. One executive likens constructing this style of plant to building a pyramid point-down: You could do it, but only with some heroic engineering. Reactors needed electric-powered pumps, and redundant cooling systems in case those failed, and massive containment structures in case those failed. The need for all of that redundancy and mass raised costs, inducing utility companies to seek economies of scale by making big reactors. Designing giant plants, each bespoke for a specific site, took years; licensing and building them took years more. “We got bogged down,” Kairos’s Peterson explained. “As we made plants bigger, we also made them unconstructable.” The creativity of the ’60s gave way to an industry that became, as John Muratore, the Kairos engineer, told me, “very formal, very bureaucratic, very slow, driven by safety concerns.” Meanwhile, as plants became ever more expensive, the relative cost of fossil fuels was declining and renewables were coming online—and, after the accident at Three Mile Island, public hostility became a problem, too.

Left to right: The Kairos Power co-founders Mike Laufer, Per Peterson, and Edward Blandford outside the facility in Albuquerque, New Mexico. (Brian Finke for The Atlantic)

And so, in a generation, nuclear power went from the fuel of the future to not worth the bother. Supply chains withered; talented engineers and executives sought greener pastures. The United States, once the industry’s world leader, became an also-ran. Today, as Peterson said, we find ourselves “mired in this world where all you can get are light-water reactors, and they’re challenging and expensive to build, and we don’t have good alternatives. Breaking out of that set of problems is one of the critical things we need to do today.” That requires technological breakthroughs; more important, however, it requires attitudinal ones.


Born in Brooklyn in 1956, John Muratore remembers visiting the 1964–65 World’s Fair, where an exhibit touted the energy of the atom in all its futuristic glory. He got an irradiated dime there and carried it around for years. (He now has a replacement that he bought on eBay.) Still, flight was his obsession, and so he took his Yale engineering degree to the Air Force’s aerospace program and then, perhaps inevitably, to NASA. After achieving his dream of serving as flight director—he oversaw five space-shuttle missions, including the first repair of the Hubble Space Telescope—he shifted to developing mission-control software. “We used a rapid iterative-build technology,” he told me, meaning that his team figured out how to develop new features in months instead of the previously customary years. The operative philosophy was build a little, test a little, fix a little.

That led him and some of his colleagues to wonder: Could they build a spacecraft the same way? In place of projects that were perfected on paper before ever being tried in space, could Silicon Valley–style trial and error work at NASA? He joined a team that used exactly those methods to build the X‑38, an emergency-reentry vehicle for astronauts on the International Space Station. Again, the team built, tested, fixed, and then repeated the cycle, learning by iterating. After a series of flights in which it was dropped from planes at varying altitudes, the X-38 was on the verge of its decisive space trial when the George W. Bush administration canceled it in a fit of parsimony. That disappointment eventually led Muratore out of NASA and, after an interlude as a professor, to SpaceX.

SpaceX was one of several private-sector competitors in a NASA program to relaunch, as it were, crewed spaceflight. The company set ambitious schedules and took big risks, a method that had its downsides: Prototypes blew up. But SpaceX proved its point. Today it is worth about $125 billion and has transformed spaceflight from a government program to a viable commercial business.

Per Peterson was among those who noticed how quickly and thoroughly SpaceX had revolutionized a staid (and in some ways troubled) industry. By his own account, Peterson had grown up “a bit of a flaming environmentalist and pretty liberal”; he put himself through college working in a bike shop before getting his doctorate, becoming an expert on heat transfer, and, as a professor at UC Berkeley in the 1990s, researching how to make nuclear-power plants safer. He came to understand how molten salt could replace water to cool a reactor core. Unlike water, molten salt stays liquid at high temperatures, so it doesn’t require ultrahigh pressurization and won’t boil away. That lets engineers dispense with heavy containment structures, allowing for smaller, cheaper, safer reactors.

Left: In-house machinery produces custom components, allowing Kairos Power to create and test prototypes quickly. Right: Muratore supervises operations in the on-site control room. (Brian Finke for The Atlantic)

Salt cooling is a technology that dates back to the 1960s but has not yet been successfully commercialized. Peterson, Mike Laufer, and a third colleague named Edward Blandford thought they could make that breakthrough by applying SpaceX’s methods. They founded Kairos in Oakland, California, in 2017, and today they have 300 employees, including Muratore, whom they nabbed in 2020. At the Kairos test center in Albuquerque, Muratore showed me an on-site machine shop—run by another SpaceX veteran—where engineers can fabricate parts in a matter of hours, and then walk them over to the test unit to see how they perform, and then refine and rework them. The idea is to make any errors fast and early, before they cause delays and overruns, and to learn during the design process how to simplify and speed up real-world manufacturing. Build a little, test a little, fix a little.


Peterson and his colleagues were not the only people to be frustrated by the industry’s failures, nor were they the only ones to launch ambitious start-ups. José Reyes, for instance, the Manhattan-born child of a Honduran father and a Dominican mother, was attracted to nuclear power in the go-go years of the 1970s, before Three Mile Island and ballooning costs kneecapped the industry. After training as a nuclear engineer, he worked for the Nuclear Regulatory Commission and then, at Oregon State University, on reactor design and testing. “I wanted to build something that was remarkably safe,” he told me. And he was intrigued by the countercultural idea of inverting traditional assumptions about economies of scale. “What happens when you go smaller?” he started to wonder. “That was kind of a surprise. You can start making these in factories.” In 2007, he co-founded NuScale Power to bring his concept to market. He says the company plans to deliver its first commercial reactor in 2027.

In my interviews with nuclear entrepreneurs like Peterson and Reyes, a pattern developed. The newcomers have engineering backgrounds but few if any ties to traditional nuclear utilities. They think that climate change is a dire problem, that nuclear power can ameliorate it, and that time is short. They don’t believe that conventional thinking offers sufficient answers, and so they take inspiration from elsewhere. Clay Sell, the CEO of an advanced-nuclear company called X-energy, cited both SpaceX and Apple, likening the company’s design process to the creation of the iPhone. Francesco Venneri, the Italian-born founder of a company he named (lest anyone miss the point) Ultra Safe Nuclear, said, “The model we’re trying to imitate is Tesla.”

The engineering choices that these companies and entrepreneurs are making vary. For instance, NuScale’s designs use water as the coolant, but rely on convection and gravity, not pumps, so they stay cool if electricity fails; Ultra Safe’s and X-energy’s use helium gas. TerraPower, another competitor, recently launched its own test of salt cooling, but using a different kind of salt from Kairos’s. What these diverse efforts share philosophically, though, is much more important than their technological differences: They seek to invert the industry’s lethargic, scale-driven business model. They think of themselves as building airplanes instead of airports—that is, as shifting the industry paradigm to mass production. (NuScale thinks it could sell three modular reactors a month; Ultra Safe hopes to start with 10 a year.) They all believe they can make nuclear fission inherently safe—and, crucially, win the public’s confidence.

Today Kairos, NuScale, Ultra Safe, and X-energy all say they can deploy advanced commercial reactors before the decade is out. The space is now rife with contenders; Third Way has identified nearly 150 companies and national labs around the world that are working on small, advanced nuclear reactors. The needed technologies are here. The goal is defined. So we’re back to the same old question: Can the industry deliver?

Some skepticism is warranted. Even if the innovators can eventually crack the code of affordable mass production, their Version 1.0 products won’t be cheap; to get launched, they will need risk-friendly investors and customers, as well as backing from Congress, the Energy Department, and government labs, not unlike the NASA incentives that propelled SpaceX. Perhaps the single biggest challenge, and one SpaceX did not face, is to modernize the slow-moving federal regulatory apparatus, which was built in our parents and grandparents’ era, when schedules were relaxed and cost overruns were fobbed off on utility customers.

Kairos Power, in Albuquerque, New Mexico (Brian Finke for The Atlantic)

Still, I came away from my conversations about the industry convinced that today presents the best opportunity in two generations for reinvention to take hold. The perception that the fight against runaway global warming could be lost within the next 20 years is a powerful motivator. So, too, is the realization that continued global reliance on oil and gas is a boon to democracy’s adversaries, most notably Russia. And if the United States fails to develop a competitive nuclear industry, our rivals will be happy to fill the gap. Russia is the predominant supplier of nuclear-power reactors in the global market, and China, which plans to build more domestic reactors in the next 15 years than the rest of the world has built in the past 35, hopes to elbow Russia aside. Those countries are also in the race to perfect the advanced, unconventional technologies that Kairos and its competitors are pursuing; China, for example, hopes to deploy a salt-cooled commercial reactor around 2030. Of course, we can assume that China and Russia will exploit any geostrategic leverage they can gain by dominating the global nuclear business. For reasons of grand strategy—as well as for safety and reliability—it would be better if U.S. companies and technologies were in the lead. All of this is on the minds of bureaucrats and politicians today.


In September, I joined a Zoom call to check on the progress of Kairos Power’s simulation experiment in Albuquerque. I saw the control room I had toured several months earlier: two rows of computer monitors facing a bank of screens that show video feeds and data streams. Besides John Muratore, only two operators—a test director and a test engineer—were in the room. Dozens of other engineers and executives monitored the proceedings from afar. The test didn’t present much of a spectacle. Supply-chain problems with heaters had delayed the launch by several weeks, but in August electricity had begun flowing into the shiny drum that mimicked an advanced reactor. Inside the simulator, hundreds of sensors dispatched data to the control room as the core’s temperature rose to the levels of a nuclear reaction.

That day, it measured almost 1,000 degrees Fahrenheit. Yet according to Muratore, the test unit was cool to the touch. At that high temperature, he told me, the system had been stable for several days, though hot spots needed attention. Early in 2023, after the hardware passed muster, salt would be introduced for weeks of evaluating and tweaking. With the results in hand, the company would begin construction of its full-fledged test reactor, with live nuclear fuel, in Oak Ridge—the same place the previous U.S. experiment with a salt-cooled reactor had been conducted, back in the 1960s. What’s old is new again.

Or rather, to be more precise, what is newest and potentially most significant about Kairos’s test is not a technological invention. Rather, it is innovation more broadly conceived. First and foremost, Kairos is devising not a nuclear technology but a business technology: a method of organizing a very complex project to be faster, simpler, more efficient, and cheaper. This kind of process innovation may not look like much, but it’s what nuclear power needs if it is to fulfill its extraordinary promise.

As my virtual tour wound down, I asked to meet the test director. Up from behind a monitor popped Davis Libbey. When I asked about his background, he said he was a recent recruit from—I should have seen this coming—SpaceX. John Muratore had snapped him up just a few months earlier. Apart from having to deal with very hot rather than very cold temperatures, he said, switching from spaceflight to nuclear power had been seamless. “From a control-room standpoint, this is very much what you’d see in South Texas or Hawthorne,” he said, referring to a SpaceX launch site and to its headquarters in California. “It’s all very similar.”

For the sake of the nuclear industry and the planet, we need to hope so.


In 1987, Congress authorized a national nuclear-waste repository at Yucca Mountain, in Nevada; for good measure, it banned permanently storing nuclear waste anywhere else. Unfortunately, that repository never opened and, thanks to obstacles both political and practical, apparently never will. Meanwhile, nuclear waste sits safely but only (in theory) temporarily at reactor sites around the country. To win public acceptance, Elizabeth Muller told me recently, the nuclear industry needs to resolve the waste problem, not just downplay it.

Muller is in her early 40s, the daughter of a physics professor. Alarmed by climate change, in 2010 she and her father started a climate-science nonprofit, Berkeley Earth, which argued that replacing coal with shale gas (a controversial proposition among some environmentalists, because it involves the water-injection process known as fracking) had to be part of the solution in the near term—and that the longer-term transition from hydrocarbons would require more nuclear power.

From their focus on natural gas, the Mullers knew that, by using computer-assisted directional drilling, an oil or gas rig can drill for miles in any direction, not just straight down but nosing horizontally along rich seams deep underground. (This transformative technology enabled the fracking revolution.) At a forum in 2015, Muller and her father, Richard Muller, heard a presentation about using boreholes to deposit nuclear waste in deep geological strata that have been stable for epochs. Her father, Muller said, “immediately thought of drilling horizontally into shale formations that have held volatile materials for millions of years.” Because geological strata are stacked horizontally, like pancakes, a vertical hole passes rapidly through them, exposing little area for potential storage. Instead, by drilling sideways to follow a suitable formation, “you get a lot more space at a given depth.” That creates more storage options at any given location, without having to truck waste to some distant (and currently nonexistent) repository.

Months after that forum, the Mullers founded a company, Deep Isolation. In 2018, they received seed funding, and the following year they showed that a drill rig on the surface could deposit specially designed waste canisters in horizontal boreholes, then later retrieve them, without any humans needing to work underground. The demonstration opened the possibility that waste can be safely stored, monitored, and if need be recovered near the sites that produce it, where communities are already accustomed to having nuclear neighbors. The company now employs about 50 people, Muller told me, and has won customer contracts in multiple countries, including the United States.

Can Deep Isolation succeed? Maybe, maybe not, but its greater significance is as an example of how the Big Nuclear mindset is cracking. Even a few years ago, the idea of an unconventional commercial start-up taking on the most intractable problem the industry faces—a problem that has defeated billions of dollars and ambitious government planning—would have seemed far-fetched, if not inconceivable.