Every kid who ever started a neighborhood lawn-mowing business knows the struggle of yanking that pull cord over and over, trying to get the mower started. After a few tries, you remember to prime the engine. You give it a few pumps. The next pull, the engine stutters, catches, and roars to life. All those flying blades of grass might as well be dollar bills dropping into your piggy bank. Well, after a bit of priming, the nuclear industry is revving its engine.

The push behind this has been public. Over the past few years, federal funding, national-lab sites, and government-supplied fuel got the first advanced reactors off the ground. Now the engine is catching, and the developers are carrying it forward themselves. They are financing their own builds, breaking ground on private land, and securing their own fuel, the marks of an industry moving from demonstration into commercial operation.

Together the five signals this week cover the whole chain, from raw uranium to a reactor at power. Behind every link sits private capital and a private operator, on land the companies own and fuel they are sourcing themselves. We start at the back of the chain, with the question the public asks first: what happens to the fuel once a reactor is done with it.

First, the country is taking on one of its oldest open questions: what to do with the fuel after a reactor is finished with it. Curio, an advanced recycling firm, signed a memorandum with NuScale Power and Framatome to evaluate turning that used fuel into new fuel and recovered materials. Curio's NuCycle process, the companies say, can cut residual waste volumes by up to 97 percent while pulling out strategic materials worth keeping. The agreement is early, a framework for feasibility and engineering studies rather than a plant, but the problem behind it is old and large. Commercial reprocessing has been effectively frozen in the United States since 1977, when the country chose to treat all used fuel as waste to be buried rather than recovered. A private consortium now proposing to reverse that, paired with the only SMR holding an NRC design approval, is moving on a question that has shadowed American nuclear for half a century. [1]

Move to the front of the chain, where the fuel is made. Centrus and X-Energy signed a supply agreement for enrichment services, both low-enriched uranium and the higher-assay HALEU that most advanced designs need, produced at Centrus's centrifuge plant in Piketon, Ohio. The part that matters is how it is financed: X-Energy will prepay Centrus in phases, scaling production against its own commercial pipeline, in what Centrus's chief executive called non-dilutive, non-debt capital. HALEU has no commercial source in the United States, and enrichers have been unwilling to build capacity without firm demand while developers cannot commit without assured fuel. Government funding has been the usual way to break that deadlock, but here a private reactor company does it directly, putting its own money down years ahead of the first kilogram. Deals like it have pushed Centrus's enriched-fuel backlog toward $3 billion, most of it under firm contract. [2]

Enrichment needs uranium to enrich, and the newest source is old. IsoEnergy and DISA Technologies agreed to form DISA Uranium, a private company built on IsoEnergy's past-producing Utah mines and DISA's process for pulling uranium out of abandoned mine waste. The venture drew a $105 million financing commitment from a group that includes BHP Ventures, Valor Equity Partners, and Halliburton Labs. The resource it targets sets it apart: more than 15,000 abandoned uranium mine sites sit across the western United States, most left from Cold War mining, many on or near tribal land, long treated as a cleanup liability with few affordable options. DISA holds what the companies call the only NRC licence of its kind to remediate that waste and recover the uranium in it. Pulling fuel out of a waste problem, rather than permitting a new mine, is how a company gets domestic uranium moving without waiting a decade for a greenfield site. [3]

From fuel to the reactors it goes into. Deep Fission, a California company, received DOE approval of the Nuclear Safety Design Agreement for its Gravity reactor, the gate that lets the design advance under the Reactor Pilot Program. What the agreement clears is a departure from how reactors are normally built. Deep Fission puts a 15-megawatt pressurized water reactor at the bottom of a borehole a mile underground, where the weight of the water column supplies the pressure a steel containment vessel provides at the surface, and the surrounding rock does the containing. Steam rises to a conventional turbine, and the reactor can be winched up for inspection. The company broke ground on a pilot at a Kansas industrial park last year and has drilled past a mile, and data-center and industrial customers have already signed letters of intent for 12.5 gigawatts. Deep Fission intends the demonstration to become a licensed, commercially operating plant, not a one-time criticality test, betting that geology can strip the containment structure and the land footprint out of a reactor's cost. [4]

That brings the chain to a reactor already running. Oklo's Groves reactor reached criticality on private land in Lockhart, Texas, the fifth to go critical under the Reactor Pilot Program and the first to do it off a government site. It went from groundbreaking to a self-sustaining chain reaction in under a year, having built the facility in 229 days. The power level is deliberately tiny. The ownership is the whole point. Oklo financed the build, developed the site from bare private ground, procured its fuel and major components on the commercial market rather than drawing on government stock, and wrote its own operating and safety programs in-house. Groves is a test platform for Oklo's isotope business and will not sell isotopes itself. Its chief executive put the shift plainly: the company used to spend its effort producing licensing paperwork, and now it is building. That is the real output, proof that a private developer can carry a reactor from empty land to criticality on its own, and having done it once, do it again. That is what a primed engine sounds like when it catches. [5]

What changed is the government's role, not its presence. Federal programs still authorize these reactors and helped build the pathways every one of these companies used. The deeper change is what private ownership does to the industry's staying power. These companies finance their own reactors, mine and enrich their own fuel, and recycle what they have already used, so a shift in Washington now has far less to switch off. Nuclear has stalled that way before. Every prior American build-out leaned on federal appetite, and each one cooled when Washington's attention moved on, leaving half-finished plants and a supply chain that withered. Private balance sheets do not empty out when a subsidy lapses. That resilience is the real signal this week, more than any single criticality. A criticality is a moment; an ownership structure compounds, making each reactor easier to fund than the one before.

The limits are worth stating plainly. The largest builds in the country, the AP1000 fleet and the first-of-a-nation projects abroad, still run on public financing and public land, and plenty of advanced work still happens inside the national labs. The private turn is real, and it is partial. The same week these American companies moved on their own money, China's government approved eight more reactors, a reminder that the state-led model is not slowing. What the United States is testing is whether a privately financed, privately fueled industry can hold that pace. This week it showed it can start.

The real measure of a subsidy is not what it builds but what it makes unnecessary. Public money works best when it ends with the private sector no longer needing it. That is what the priming was for, and this week a corner of the nuclear industry proved it no longer needs the hand that started it.

The engine starts easily enough. The open question is whether privately financed nuclear keeps running when the first project slips or the first market cools, with no government hand nearby to steady the throttle.

More next week.

Dive deeper

  1. Curio, NuScale, and Framatome Partner on Used-Fuel Recycling Curio signed a memorandum of understanding with NuScale Power and Framatome to evaluate source-to-product and source-to-fuel pathways for materials recovered through Curio's proprietary NuCycle technology, which the company says can reduce residual waste volumes by up to 97 percent while recovering strategic nuclear materials. The parties will conduct technical assessments, feasibility studies, and supply-chain analyses toward possible future development and commercial agreements. Commercial reprocessing of used fuel has been effectively prohibited in the United States since 1977, when the country chose to treat all used fuel as high-level waste; earlier this year the DOE's Office of Nuclear Energy awarded more than $19 million to five companies, Curio among them, to develop recycling technologies.
  2. X-energy and Centrus Sign HALEU Supply Agreement Centrus and X-energy signed an agreement for Centrus to provide low-enriched uranium and high-assay low-enriched uranium (HALEU) to fuel X-energy's Xe-100 high-temperature gas-cooled reactors, produced at Centrus's American Centrifuge Plant in Piketon, Ohio. X-energy will prepay Centrus in phases to scale production against its commercial pipeline, in what Centrus called non-dilutive, non-debt capital. HALEU has no commercial source in the United States, and Centrus reports a roughly $3 billion contingent LEU and HALEU backlog, of which about $2.4 billion is definitised. The HALEU will feed X-energy's TRISO-X fuel fabrication facility in Oak Ridge, Tennessee.
  3. IsoEnergy and DISA to Form a New US Uranium Company IsoEnergy and DISA Technologies agreed to create DISA Uranium, combining IsoEnergy's past-producing conventional uranium mines in Utah with DISA's High-Pressure Slurry Ablation technology and its mine-waste remediation and recovery business. The venture secured a $105 million financing commitment from investors including BHP Ventures, Valor Equity Partners, and Halliburton Labs, with IsoEnergy taking about a 33 percent stake. DISA holds an NRC license to remediate abandoned uranium mine waste, of which more than 15,000 sites sit across the western United States, largely from Cold War-era mining, and to recover the uranium and vanadium they hold.
  4. DOE Approves the Safety Design for Deep Fission's Underground Reactor The DOE approved the Nuclear Safety Design Agreement for Deep Fission's Gravity reactor, allowing the design to advance under the Reactor Pilot Program. The Gravity reactor is a 15-MWe pressurized water reactor placed at the bottom of a borehole about one mile underground, where the weight of the water column supplies operating pressure and the surrounding rock provides containment; non-radioactive steam rises to a surface turbine and the reactor can be raised for inspection. Deep Fission broke ground on a pilot at the Great Plains Industrial Park in Parsons, Kansas, in December 2025 and has drilled past a mile, and it intends the demonstration to become an NRC-licensed, commercially operating unit rather than a one-time criticality test. The company has signed letters of intent totaling 12.5 GW.
  5. Oklo's Groves Reactor Reaches Criticality on Private Land Oklo's Groves Isotope Test Reactor in Lockhart, Texas, reached criticality on August 5, the fifth reactor to go critical under the DOE Reactor Pilot Program and the first to do so on private land. Oklo built the facility in 229 days and moved from groundbreaking to startup authorization in just over ten months, financing the build, developing the private greenfield site, procuring fuel and major components commercially, and writing its own operating and safety programs rather than relying on an existing national-laboratory framework. Groves is a low-power test platform for Oklo's isotope business and will not produce saleable isotopes; its purpose is to prove the company can design, build, and operate a reactor to inform future isotope-production facilities.

Process note: This brief is created using an AI-assisted workflow and reviewed before publication. Learn more about Finding Critical Path and how each edition is built at About — FindingCriticalPath.com.