The Tennessee Valley Authority’s Clinch River site in Oak Ridge, Tennessee, has been waiting for a nuclear reactor since the 1980s, when Congress killed a breeder reactor project there after billions in cost overruns. In May 2026, the Department of Energy signaled that the wait may finally be ending: it awarded TVA and Holtec Government Services up to $400 million each to build two separate small modular reactors, the largest federal investment in SMR deployment the country has ever made.
The combined $800 million commitment, announced through DOE’s Office of Clean Energy Demonstrations, targets Generation III+ reactor designs and uses a milestone-based funding structure that withholds payments until each company hits verified construction and licensing benchmarks. For an industry haunted by the Vogtle expansion in Georgia, which came in at roughly $35 billion and seven years behind schedule, the structure is as much a statement of intent as the dollar figure: the federal government wants to prove that smaller, factory-style nuclear plants can actually get built on time and on budget in the United States.
Two projects, two paths
TVA’s project will deploy a GE Vernova Hitachi BWRX-300 reactor at the Clinch River site. The utility holds a significant regulatory head start: the Nuclear Regulatory Commission issued an Early Site Permit for Clinch River in 2019, following an application TVA filed in May 2016. That permit confirms the site’s suitability for a reactor but does not authorize construction. TVA still needs a construction permit or combined license specifically for the BWRX-300, a process that historically takes several years for first-of-a-kind designs.
Holtec’s award supports a separate SMR deployment, but the DOE announcement provides fewer specifics. Holtec has promoted its SMR-160 design in other contexts, and the company is no stranger to federal nuclear partnerships. DOE’s Loan Programs Office extended a conditional commitment of up to $1.52 billion to support restarting the 811-megawatt Palisades nuclear plant in Michigan, whose operating license transferred from Entergy to Holtec on June 28, 2022. The SMR award and the Palisades restart are distinct efforts, but together they make Holtec the only company simultaneously pursuing both a reactor restart and a new SMR build with federal financial backing.
Both awards fall under DOE’s Generation III+ SMR Pathway to Deployment program (solicitation DE-FOA-0003485). The broader program carries a $900 million ceiling, with roughly $100 million reserved for smaller Tier 2 awards aimed at additional SMR concepts.
Why the funding structure matters more than the dollar amount
The money flows through Other Transaction agreements rather than traditional grants or cost-reimbursement contracts. That distinction is critical. Traditional federal energy grants reimburse costs as they pile up, which can insulate projects from the financial discipline that forces private developers to stay on schedule. OT agreements, by contrast, tie each payment tranche to a verified milestone: completing a licensing submission, pouring a foundation, passing an NRC inspection.
The program solicitation describes a phased structure with payments keyed to progress in design, licensing, procurement, construction, and commissioning. But the exact milestone schedules, dollar amounts per tranche, and quantitative thresholds that TVA and Holtec must meet have not been made public. That gap matters. Without those details, outside analysts cannot assess whether the OT structure will genuinely compress construction timelines or simply provide a new label for the same slow disbursement patterns that have plagued previous nuclear projects.
The harder question is enforcement. Will DOE renegotiate milestones if vendors encounter supply-chain bottlenecks or new regulatory requirements? Or will it hold the line, even at the risk of seeing a marquee project stall? OT agreements are only as tough as the agency willing to enforce them.
The shadow of NuScale and Vogtle
Any serious discussion of U.S. SMR prospects has to reckon with recent history. The NuScale Carbon Free Power Project in Idaho, previously the furthest-along SMR effort in the country, was formally terminated in November 2023 after its estimated cost per megawatt-hour rose roughly 75% from initial projections. The Utah Associated Municipal Power Systems, which was supposed to buy the electricity, could not secure enough subscribers at the higher price, and the project collapsed.
The Vogtle expansion tells a parallel cautionary tale at larger scale. Units 3 and 4, which entered commercial service in July 2023 and April 2024 respectively, were the first new commercial reactors built in the U.S. in roughly three decades. They also came in at approximately $35 billion, more than double the original estimate, and years behind schedule. SMR proponents argue that smaller, factory-fabricated designs avoid those problems by standardizing components and reducing on-site construction complexity. That argument is plausible but unproven at commercial scale in the American regulatory and construction environment.
Internationally, the picture is more advanced. China’s HTR-PM high-temperature reactor began commercial operation in December 2023, and Ontario Power Generation is pursuing an SMR at the Darlington site in Canada. The DOE awards are, in part, a response to the risk that the U.S. falls behind in a technology it pioneered.
What is driving the urgency
The timing of these awards is not accidental. Electricity demand across the U.S. is rising at its fastest pace in two decades, driven largely by the explosive growth of AI data centers, manufacturing reshoring, and the electrification of transportation and heating. Utilities that once planned for flat or declining load growth are now scrambling for firm, around-the-clock power sources that do not emit carbon.
Natural gas plants can fill the gap quickly but lock in fossil fuel dependence. Wind and solar are cheap but intermittent. Battery storage is improving but cannot yet cover multi-day demand surges. SMRs, if they can be built affordably and on schedule, offer something none of those alternatives provide on their own: compact, carbon-free baseload power that can be sited near demand centers, including the industrial campuses and data center clusters that are reshaping the American grid.
That “if” is doing a lot of work in that sentence. Neither TVA nor DOE has published projected electricity rates or cost-per-megawatt-hour estimates for the Clinch River SMR. For TVA’s customers across seven southeastern states, the question of whether a 300-megawatt reactor will produce power at competitive prices is not abstract. Federal subsidies can reduce the upfront capital burden, but operating costs, fuel procurement, regulatory compliance, and eventual decommissioning expenses will ultimately flow through to electricity bills.
What still needs to happen
The awards are a starting gun, not a finish line. TVA must secure an NRC construction permit or combined license for the BWRX-300 at Clinch River, a process with no public timeline from the commission. Holtec has yet to publicly confirm its reactor technology and deployment site for this specific award. DOE has not specified whether it expects one project to reach commercial operation before the other, or how it will evaluate success if the two efforts diverge in pace.
Tier 2 awards, expected to be smaller and aimed at additional SMR concepts, have not been announced, and their timing relative to the flagship projects remains unclear. Workforce readiness is another open question: building and operating SMRs requires specialized labor, from nuclear-qualified welders to reactor operators, and training pipelines take years to fill.
The federal government has moved beyond generic support for “advanced nuclear” and is now underwriting two specific Generation III+ SMR deployments with substantial, performance-based funding. Whether that bet pays off will depend less on Washington’s enthusiasm and more on the unglamorous realities of licensing schedules, construction productivity, supply-chain execution, and cost control. The money is committed. The milestones are set. Now someone has to actually build the reactors.
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*This article was researched with the help of AI, with human editors creating the final content.
