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Why Small Modular Nuclear Reactors Are a Dead End

The big question is, can SMRs deliver on their promises to overcome the historic drawbacks of conventional nuclear power? The answer is no.

Richard Heinberg, May 19, 2026, Common Dreams, https://www.commondreams.org/opinion/smrs-dead-end

The nuclear power industry is currently promoting designs for small modular reactors, or SMRs, that will supposedly be cheaper, safer, and faster to build than older nuclear power plants. Bill Gates and Amazon are investing in the technology. Moreover, some environmentalists, including Mark Lynas and Bill McKibben, support SMRs in the hope that they can lower carbon emissions. And, according to polls, far more Americans now approve of the development of nuclear energy than was the case just a decade or two ago.

This year, the world has been plunged into a global energy crisis: With the closure of the Strait of Hormuz, nearly a fifth of world oil shipments have been held up, with economic impacts likely to reverberate for months or years. World leaders are suddenly desperate for energy alternatives, and are turning to solar, coal, and nuclear. At the same time, electricity demand for data centers is exploding, and builders of those centers hope to use SMRs to power artificial intelligence (AI).

In short, it looks like a great moment for the nuclear industry.

Yet Indigenous peoples, technology critics, and old-school environmentalists still oppose nukes—even in new, highly touted forms. I agree with their critiques. In this article, we’ll look at the current nuclear revival and see why it may end up being a zombie attack.

Nuclear Renaissance?

Before looking at SMRs specifically, it’s helpful to understand the status of the nuclear industry in more general terms. The industry’s potential resurgence comes after three decades in the doldrums following the Chernobyl catastrophe in 1986. Today, roughly 440 nuclear power plants, spread across 30 countries and with a combined net capacity of around 400 gigawatts (GW), provide about 10% of the world’s electricity.

If you think, as I do, that the global polycrisis is an inevitable outgrowth of industrialism and its consequences (resource depletion, pollution, and overpopulation), then you’re likely to view SMRs as a pointless and dangerous waste of resources.

The US, which has the largest number of plants of any country (96), is seeing a slow phaseout of old reactors (average age 44 years), but has commissioned three new ones during the last decade. China is now operating 60 reactors, with up to 40 others under construction. India is likewise hoping to grow its nuclear industry rapidly and is experimenting with fast breeder reactors. Globally, the International Energy Agency forecasts total nuclear power capacity to grow to over 700 GW by 2050, and small modular reactors are expected to make up a significant share of this growth. A year ago, the Trump administration unveiled an ambitious nuclear strategy that includes a goal to quadruple the United States’ nuclear capacity by 2050, with SMRs playing a key role.

The principal drivers of renewed interest in nuclear power are climate change (globally), the Trump administration (in the US), tech companies’ voracious demand for electricity, and Asian nations’ hunger for more industrial power. Most nations want to limit their carbon emissions, and the main low-carbon alternatives to fossil fuels are solar, wind, hydro, and nuclear. Solar and wind are intermittent (“variable”) sources, requiring energy storage to align electricity supply with demand. Hydro has limited potential for growth. That leaves nuclear power, which has the advantage of being reliable and steady, and has possibilities for expansion.

If it’s helpful to understand why the industry is growing again, it’s just as important to know the reasons for its long period of dormancy:

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  Cost: Nuclear power plants are complex and expensive, employing technology that’s internationally regulated due to concerns about proliferation of nuclear weapons. Despite over 80 years of the industry’s development, nuclear plants still take a long time to build and are often plagued with cost overruns.
• Fuel: Uranium, the fuel for nearly all existing nuclear power plants, is a depleting nonrenewable resource, and supplies are running short. Uranium mining is a dirty, expensive process, and mine closures, mostly due to resource depletion, are expected to lead to fuel shortfalls by 2035. While geologists have identified more uranium resources, opening new mines will entail further environmental destruction and harm to human communities, of which the uranium mining industry already has a grim history.
• Waste: Despite decades of research, the global nuclear industry still has found no good place to put the 300,000 tons of nuclear waste—as well as 480,000 tons of depleted uranium in the US alone—that it has produced in the last 80+ years.
• Safety: While nuclear accidents are relatively rare, they can be devastating and expensive when they occur. The Fukushima disaster of 2011 resulted in direct cleanup costs of up to $180 billion as of 2016, but the damage still has not been completely contained, and indirect costs to human health have been estimated at half a trillion dollars. Further, nuclear power technology is still tied to the threat of nuclear weapons proliferation.
• Water Issues: Nearly all nuclear power plants use water as a coolant and are highly vulnerable to droughts and floods. Droughts reduce the availability of water for cooling, while floods (nuclear plants are generally built next to rivers, lakes, and other bodies of water) damage safety infrastructure and risk contaminating water sources.

If the nuclear industry can overcome its historic obstacles, a door is open. According to the industry, small modular reactors are the main way forward.

SMRs: Promise or Hype?

The main arguments for SMRs are that they would be cheaper and faster to build than conventional power plants; that they would be safer; and, being smaller, that they could be installed to power remote towns or data centers. The idea is to build components in a centralized factory and then assemble those components at power generation sites.

“Small” is defined as 300 megawatts of electrical power or less. While most existing nuclear plants are in the one-gigawatt (1,000 MW) range, some proposed SMRs are 20 megawatts or less; these are called “micro” reactors.

For the most part, SMRs are still at the design stage. China has one SMR under construction. In the United States, TerraPower, founded by Microsoft’s Bill Gates, has received a permit to build a 345-megawatt (not exactly “small,” but close) sodium-cooled reactor in Kemmerer, Wyoming.

Clearly it is possible to get funding and approval for these new-generation power plants. The big question is, can SMRs deliver on their promises to overcome the historic drawbacks of conventional nuclear power?

• Cost: SMRs will only be cheaper to build if large numbers are ordered; the first prototypes may be even more costly than conventional plants. Meanwhile, construction costs per MW of capacity will likely be higher, and operating costs are largely unknown until real-world data can be collected. The cost of electricity from SMRs is therefore also yet-to-be-determined, but preliminary estimates put it much higher than solar or wind.
• Fuel: Most proposed SMRs use uranium, but some designs on the drawing boards would use depleted uranium or thorium as fuels (see below). For now, however, the uranium fuel constraint looming over the nuclear industry remains in place. SMRs also won’t use their fuel more efficiently than conventional reactors, despite some claims to the contrary.
• Uranium From Seawater: The supply limits of uranium could be greatly expanded by harvesting it from seawater, where the potential resource is enormous—albeit at a concentration of about 3.3 parts per billion. The total oceanic uranium resource is estimated at 4.5 billion tons, over 500 times all identified land-based uranium resources. However, extracting the uranium will take a lot of energy: The best existing technology using absorbent materials will offer an energy return on energy invested (ERoEI) of about 4:1, which is lower than the ERoEI for solar, wind, hydro, fossil fuels, or conventional uranium mining.
• Waste: Some proposed SMR designs would be breeder reactors that could get rid of depleted uranium or even nuclear waste by using them as fuels—but this technology has faced significant challenges (see below). Otherwise, SMRs will do nothing to solve, and may actually worsen, the nuclear waste dilemma.
• Safety: SMRs are designed to be safer than conventional nuclear plants, using passive, gravity-driven cooling systems that don’t require electricity or human intervention to shut down. However, their overall safety is controversial. There is still no real-world data to support the industry’s promises. And having lots of smaller nuclear plants dotted across the landscape could make it easier for nuclear materials to end up in the hands of bad actors. The resilience of SMRs in the face of more frequent and more severe natural disasters is also controversial; a 2021 study concluded that storms, droughts, and higher ambient temperatures linked to climate change are likely to pose operational risks to all nuclear power plants.

The biggest remaining advantages of SMRs are the speed with which they could bedeployed once the manufacturing infrastructure is in place, and the prospect of providing non-grid-tied dedicated power sources for data centers.

What About Further Technological Advances?

When confronted with the limits of one technology, nuclear advocates often shift the conversation to another. However, close examination usually shows that each technological “solution” has its own problems:

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  Fast-Breeder Reactors: If nuclear fuel is scarce, why not develop fast breeders, which produce more nuclear fuel than they consume? Currently, Russia operates two fast breeders and India’s first one reached criticality in late April. China has a fast-breeder reactor for research. The US, France, and Japan operated breeders in the past but have shut down research along these lines due to high capital and operational costs, safety risks related to sodium coolant, and nuclear proliferation concerns.

• Alternative Cooling Systems: Water-cooled reactors (a category that includes nearly all existing commercial nuclear plants) pose risks of loss-of-coolant accidents due to pipe breaks, high-pressure operation failures, age-related component deterioration, and earthquakes or other natural disasters. The industry’s solution: Use sodium or helium as a coolant. Unfortunately, sodium is highly chemically reactive and ignites upon contact with air and reacts explosively with water, while helium is a depleting non-renewable resource that is becoming economically scarce at a rapid rate.
• Thorium Reactors: If uranium is scarce and might lead to weapons proliferation, why not use more abundant thorium? China already has an experimental two-megawatt thorium reactor in the Gobi Desert. However, thorium reactors have steep development costs and produce a highly radioactive byproduct, uranium-232, which decays into isotopes that emit penetrating gamma rays, making fuel handling and maintenance more hazardous and costly. Also, thorium reactors require a “driver” fuel: Thorium-232 is fertile, not fissile, meaning it needs a different radioactive fuel (like uranium or plutonium) to initiate the chain reaction. Therefore, proliferation concerns remain.

Currently, there is little real-world data regarding these “new” nuclear technologies, even though all have been discussed or experimented with for decades. The nuclear industry hasn’t actually solved its many dilemmas, and the current nuclear renaissance isn’t being driven by novel solutions so much as by the rapid worsening of society’s energy-related problems, primarily climate change:  World leaders are now so desperate for reliable low-carbon energy sources that they are willing to overlook substantial risks, if only the nuclear industry will put a shiny gloss on its latest iteration of products. And leaders of the tech industry, keenly aware of the soaring electricity demand from AI, are even more desperate for ways to power the exponential growth of their companies without risking a backlash from the rest of society, which may suffer from higher electricity prices or shortages.

If Not SMRs, Then What?

Nuclear power is a product of high-tech modern industrialism. The proponents of nuclear power assume—and nuclear reactors rely on—global supply chains, uninterrupted grid power, reliable water resources, and functioning political systems. The future that’s unfolding around us is a polycrisis in which supply chains, grid power, water, weather, and politics-as-usual are all threatened. In these unfolding circumstances, the only solutions that make sense are ones that are small-scale, local, low-risk, and nature based.

What to do about carbon emissions? Yes, we need to replace fossil fuels with low-carbon energy sources—but these should be as low-tech as possible, and we should aim to reduce overall energy usage.

What to do about AI data centers? That’s easy: Don’t build them. We are rushing headlong into an AI-managed future without an adequate understanding of what AI is, does, or is likely to do in the future. Besides, AI appears to be perhaps the biggest investment bubble in history.

Most political and economic leaders have taken the attitude that we must go to any possible lengths to save industrial modernity. But industrial modernity is the essence of our problem: It is a crisis-generating machine—and one that, prior to its inevitable self-destruction, is creating enormous wealth for a small minority of people, while entrapping everyone else in dreary systems of employment, payment, debt, dependency, and distraction that leave little time for reflection on the futility of it all.

Moreover, SMRs will do nothing to solve our immediate global energy crisis. The oil shortages that are already sweeping over the world in the wake of the US-Iran war cannot, in most cases, be offset with electricity—at least not right away. While electrification is a good interim energy strategy for gradually winding down modernity with minimal casualties, it’s one that will take time, and some things will be hard or impossible to meaningfully electrify—including heavy manufacturing and air travel. Meanwhile, the world needs gasoline, diesel, and jet fuel now; SMRs will take decades to deploy.

The opinion you hold about SMRs will have a lot to do with your general attitude toward technology. If you think humanity’s fate and future rest with high tech (including AI and advanced rockets to enable colonization of other planets), then you’re almost guaranteed to believe that SMRs will help us get there. But if you think, as I do, that the global polycrisis is an inevitable outgrowth of industrialism and its consequences (resource depletion, pollution, and overpopulation), then you’re likely to view SMRs as a pointless and dangerous waste of resources.

Once we see why industrial modernity is unsustainable, the most important question becomes: What is a viable exit strategy? On our way out the door of modernity and back toward simplicity, we need to minimize the creation of new problems and relearn nature’s elegant solutions. When our priorities are thus reoriented, nuclear power makes no sense.

May 24, 2026 Posted by Christina Macpherson | Small Modular Nuclear Reactors | Leave a comment

SMRs Aren’t Losing on Technology- They’re Losing on Economics

To put it bluntly: SMRs compete in an economy that no longer exists. Renewables and storage are not just low-carbon. They are modular economic units that can be deployed incrementally, financed through asset-level debt, and brought online quickly enough to generate early revenues. SMRs can generate low-carbon electricity. But they cannot generate early cash flows.

Oil Price, By Leon Stille – May 11, 2026, 

• Small Modular Reactors (SMRs) are still unlikely to drive the energy transition because renewables, batteries, and grid flexibility attract far more investment, scale faster, and generate quicker returns.
• The main barrier is no longer just technology or timelines, but economics.
• While SMRs may find niche uses in industrial clusters or remote grids, offshore wind, solar, storage, and transmission upgrades are already delivering emissions cuts and energy security today

Small Modular Reactors still won’t shift the Energy Transition, but for a different reason

Last year, I argued that small modular reactors will not save the energy transition. The core reasoning was simple: timelines were too long, costs too uncertain, and grid issues too persistent for SMRs to meaningfully scale in the critical decade ahead. Today, as the UK’s flagship SMR programme unfolds and European policymakers cast fresh doubt on offshore wind targets by pointing to Rolls-Royce’s design, one thing is clear: SMRs remain promised, not delivered. But the missing piece in the debate is no longer just timing, it is market prioritisation and capital competition.

The energy transition is in a race against time. Technologies compete not only to be clean, but to be investable, scalable and system-relevant within the lifespan of existing assets. In that competition, SMRs face structural disadvantages that go far beyond technology readiness.

Why SMRs Compete in the Wrong Economy

In the early rhetoric around SMRs, the narrative was framed as a simple trade-off: renewables bring intermittency and grid stress, nuclear brings dispatchability and firm power. This framing obscured a deeper point. Energy systems are not zero-sum puzzles where one technology simply replaces another. They are investment ecosystems where capital flows to where returns are fastest, risks are lowest and policy support is stable.

Today, that ecosystem overwhelmingly favours renewables, storage and flexibility solutions. Wind and solar are not just cheaper on a levelised cost basis; they integrate more naturally with digital grids, modular financing, and hybrid infrastructure strategies that combine solar, wind, batteries, demand response and interconnection. SMRs, by contrast, are large engineering builds with long lead times and high upfront capital requirements.

The UK’s own SMR timeline underscores this mismatch. The first unit is now expected to be ready for testing around 2030–2032. That means commercial deployment could be a decade after that. In the same period, offshore wind capacity alone in Europe is projected to grow to tens of gigawatts, not hundreds, but enough to reshape grid dynamics, storage markets and decarbonisation pathways well before SMRs arrive.

When capital is scarce, investors do not wait for future returns; they bet on near-term cash flows. This helps explain why renewable projects, battery factories, transmission upgrades and hydrogen early markets are attracting orders of magnitude more private investment than SMRs. The market has already judged where returns are likeliest in the 2020s and early 2030s.

The Myth of Dispatchable Value

Proponents of SMRs argue that dispatchable power is valuable. This is true, but the value is context-dependent. The grid of 2026 already recognises firm capacity mainly through metrics tied to flexibility, not base load. Batteries, demand response, grid balancing markets and sector coupling (including green hydrogen and power-to-x) are all mechanisms that provide firm contribution without nuclear scale and risk.

More importantly, the value of dispatchable nuclear is increasingly decoupled from peak system needs. Today’s grids prioritise fast response, fine-grained balancing rather than slow, heavy baseload adjustments. In that environment, SMRs structurally deliver late, heavy, and rigid capacity rather than fast, flexible, adaptive capacity.

When the UK and other European governments talk about SMRs, the discussion often centres on engineering and regulation. But the real barrier is economics. Nuclear economics are borne from a model built in an age of fully centralised grids and cost-plus financing. That model is misaligned with today’s competitive power markets, where value is increasingly derived from short-duration flexibility, spot pricing, and hybrid energy packages.

SMRs and Industrial Strategy

This is not to say SMRs have no future. In specific industrial contexts, heavy industrial clusters, remote non-interconnected grids, certain process heat applications, SMRs could be a useful tool. But that does not make them central to decarbonisation at scale.

Europe’s energy transition is not only about electricity. It is about electrification of heat, transport and industry, grid flexibility, and system integration. Offshore wind, for all its critics, delivers carbon-free electrons today. It creates entire industrial supply chains, workforce development pathways and export sectors. SMRs create jobs too, but only after a decade of development, regulation, licensing and capital deployment.

This mismatch is not trivial. Public budgets and political capital are finite. When policymakers debate whether to prioritise a gigawatt of wind or invest in a nuclear unit that might deliver in the next decade, the choice reflects not only technology readiness but opportunity cost.

Timelines Are Only the Surface Issue

Critics of SMRs often focus on schedule slippage. That is a real issue. But it is a symptom, not the fundamental problem. The deeper reality is that the global energy transition prioritises technologies that can deliver measurable impact within this decade. Market forces, investor preferences and policy frameworks all align with that priority. Expecting SMRs to become a backbone of the system …………………………………………………………………………………………………………………….https://oilprice.com/Alternative-Energy/Nuclear-Power/SMRs-Arent-Losing-on-Technology-Theyre-Losing-on-Economics.html

May 17, 2026 Posted by Christina Macpherson | Small Modular Nuclear Reactors | Leave a comment

Nuclear Scaling Requires Discipline. SMRs Deliver Fragmentation.

the evidence does not support treating SMRs as a broad, near-term, commercially validated solution

Michael Barnard, Clean Tecnica 28th April 2026, https://cleantechnica.com/2026/04/28/nuclear-scaling-requires-discipline-smrs-deliver-fragmentation/

When I wrote in 2021 that small modular reactors were mostly bad policy (peer reviewed version, CleanTechnica version), the argument was not that nuclear fission could not produce useful low-carbon electricity. It was already doing so every day. The United States had about 98 GW of operating nuclear capacity, and the global fleet was a major source of firm generation. The question was whether the SMR policy proposition matched the conditions under which nuclear power had scaled in the past. It did not then. The evidence since then has made the problem clearer.

The original SMR case rested on a simple promise. Make reactors smaller, build more of them in factories, reduce capital at risk, shorten construction schedules, serve more sites, and avoid the large-project failures that had damaged recent nuclear construction in liberalized electricity markets. It was an appealing story because it pointed at real nuclear problems. Large reactors are expensive to finance. They take a long time to build. A single failure can consume a utility’s balance sheet and a government’s political patience. A smaller unit sounds easier to manage.

But the promise depended on a condition that was often treated as background noise. SMRs only make economic sense if the sector converges on a few designs and builds them many times. Factory manufacturing does not create a learning curve because the word factory appears in a presentation. Learning curves come from repeated production of the same or similar products, with stable tooling, stable suppliers, stable inspections, stable quality assurance, stable training, and steady demand. Solar panels, batteries, and wind turbines became cheaper because the world made huge numbers of related products in shorter production cycles. Nuclear reactors are different. Each design carries a safety case, a fuel qualification pathway, licensing work, site work, security, emergency planning, operator training, waste arrangements, and decades of liability.

That was the central weakness in the SMR story in 2021. In that earlier assessment, I counted 57 SMR designs and concepts across 18 broad types, and none could be considered dominant. That was already far too fragmented for a credible manufacturing-learning argument. Since then, the OECD Nuclear Energy Agency’s SMR dashboard has tracked more than 120 SMR technologies worldwide, with roughly 70 to 80 included in recent dashboard editions after filtering out some paused, inactive, unfunded, or non-participating designs. The sector has not moved from many concepts to a few winners. It has become more crowded.

This matters because nuclear design proliferation is not cheap experimentation. In software, a hundred teams can try different approaches, fail fast, and leave lessons behind. In nuclear, each credible design requires scarce engineering, regulatory, fuel-cycle, owner, and supply-chain attention. A light-water SMR, a high-temperature gas reactor, a sodium fast reactor, a molten-salt reactor, and a microreactor are not minor variations around a shared product platform. They create different materials questions, fuel requirements, operating temperatures, inspection regimes, safety cases, and licensing pathways.

The EIA’s April 2026 Today in Energy article is useful because it lays out that diversity. It groups U.S.-relevant SMRs and microreactors into light-water reactors, high-temperature gas reactors, molten-salt reactors, sodium-cooled reactors, and other designs. It identifies applications such as AI loads, data centers, industrial sites, remote areas, microgrids, and military or federal facilities. It points to DOE programs, pilot pathways, and fuel-chain efforts. As a map of activity, it has value. As a test of whether the SMR proposition is becoming a real deployment class, it is much weaker.

The EIA article does not ask the questions that matter for scaling. It does not ask whether the order book is large enough to support factory learning. It does not ask whether design proliferation undermines standardization. It does not ask whether the credible projects are really small, or whether they are drifting back toward conventional power-station scale. It does not ask whether remote sites, mines, and islands are large enough markets to sustain a reactor manufacturing industry. It does not ask whether HALEU will be available at scale on the timelines implied by advanced reactor plans. It describes activity and optionality. It does not demonstrate convergence.

The historical conditions for nuclear scaling are not mysterious. Nuclear built at scale where it was treated as a national strategic program, where the state played a strong role, where designs were standardized or semi-standardized, where large reactors spread fixed costs over a lot of output, where experienced nuclear owner-operators existed, where training and safety culture were centralized, and where governments sustained programs for decades. France, South Korea, and China did not scale nuclear power by letting dozens of small reactor startups compete for scattered boutique sites. They scaled, to the extent they did, through alignment among state policy, utilities, vendors, regulators, finance, and workforce.

SMRs were sold as a way around these conditions. The actual market is rediscovering them. The projects that look most likely to be built are tied to existing nuclear sites, state-backed strategic sites, experienced utilities, military or laboratory settings, or large industrial anchors with public support. That does not mean they are worthless. It means they are not validating the broad SMR pitch. They are validating the old lesson that nuclear needs strong institutions.

The most credible projects are also getting bigger. Ontario’s Darlington project is the clearest Western example. Ontario Power Generation has a license to construct one GE Hitachi BWRX-300 at Darlington, with four units planned. Each unit is about 300 MW. This is a serious project, but it is not a small reactor scattered into a new class of sites. It is a 300 MW boiling water reactor at an existing nuclear site, backed by an experienced provincial nuclear operator with grid interconnection, cooling access, security culture, political support, and a long-term system need. If it succeeds, it will matter. But it will not prove that SMRs can escape nuclear’s institutional requirements.

China’s Linglong One, the ACP100 at Changjiang in Hainan, is another real project. At about 125 MW, it is closer to the traditional idea of a small reactor, and it has moved through construction and testing milestones. But it exists inside China’s state-led nuclear program. China can choose, license, finance, build, and integrate nuclear projects in ways that liberalized markets struggle to copy. That makes Linglong One important, but it does not make it proof that a global commercial SMR market has arrived.

TerraPower’s Natrium project in Kemmerer, Wyoming, is serious as well, with a construction permit issued by the U.S. Nuclear Regulatory Commission and non-nuclear site work underway. But Natrium is 345 MW, with storage-boosted output advertised around 500 MW. It sits above the old 300 MW SMR threshold and depends on sodium cooling, HALEU fuel, major public support, and a coal-site transition narrative. It may become a useful advanced reactor demonstration. It is not evidence that small, repeatable, low-risk nuclear products are ready for broad deployment.

Rolls-Royce makes the size drift even more obvious. Its reactor is about 470 MW. Three units at Wylfa would total about 1.4 GW, which is a large power station by any normal electricity-system measure. The unit is small only compared with the largest conventional reactors. It may fit the United Kingdom’s industrial strategy if the government commits to a fleet. But at 470 MW, the project is better understood as a medium reactor with modular construction ambitions than as the small product implied by early SMR rhetoric.

Holtec’s design history points the same way. The SMR-160 became the SMR-300. NuScale’s module moved from 50 MW toward 77 MW, and the commercial plant concept became a multi-module station approaching conventional plant scale. X-energy’s Xe-100 is about 80 MW as a module, but Dow’s proposed Seadrift project packages four units into about 320 MW. The pattern is clear. The more serious the customer discussion becomes, the more the sector tries to put several hundred MW behind a single site, operating organization, licensing file, security plan, and grid connection.

That is not an accident. Nuclear has large fixed costs that do not shrink in proportion to reactor size. A 50 MW reactor does not need one-twentieth of the licensing effort, one-twentieth of the security analysis, one-twentieth of the operator training, one-twentieth of the emergency planning, one-twentieth of the quality assurance, or one-twentieth of the waste arrangements of a 1,000 MW reactor. Some hardware costs scale down. Many institutional costs do not. Smaller reactors start with a scale penalty. Factory repetition is supposed to overcome it. But repetition requires a narrow set of designs and a large order book. The current market offers neither.

After years of SMR hype, the likely-build list remains short: Darlington, Linglong One, Natrium in Wyoming, TVA’s Clinch River, Dow’s Seadrift project, Holtec’s proposed Palisades units, Rolls-Royce at Wylfa, and Russian RITM-based Arctic or floating projects. That is not nothing, but it is not a broad commercial market. It is a small order book of state-backed, utility-backed, or strategic projects, often tied to existing nuclear or heavy-industrial sites, often larger than the original SMR story implied, and often dependent on public risk absorption. By contrast, the press-release order book is filled with memoranda of understanding, technology selections, data-center announcements, export discussions, remote-site narratives, and vendor road maps. Those are not reactors. Nuclear projects have a long valley between interest and electrons.

HALEU sits near the center of the problem, not at the edge of it. Several advanced reactor designs require higher-assay low-enriched uranium, enriched above the 3% to 5% U-235 common in today’s light-water reactor fuel but below 20%. HALEU can support smaller cores, longer operating cycles, higher burnup, and reactor designs that standard low-enriched uranium cannot support. That is why developers want it. It is also why it is a bottleneck.

The United States does not yet have a mature, large, domestic HALEU supply chain. Russia has been the major commercial source, which is now a strategic and political problem. Rebuilding a domestic chain requires conversion, enrichment, deconversion, fuel fabrication, transport packages, licensing, inspections, safeguards, workforce, and customer commitments. Each link needs facilities, capital, permits, contracts, and time. This is not a paperwork problem. It is an industrial-base problem.

There is a circular dependency at the heart of it. Reactor developers need HALEU to make credible deployment commitments. Fuel suppliers need credible reactor demand to justify investment. Customers need confidence that both reactor and fuel will be available. Regulators need data on fuel behavior and safety. Government can break pieces of the loop by funding fuel production and demonstration quantities, but that confirms that the strategy is government-led. It does not show that advanced SMRs are market-ready.

HALEU also makes design proliferation more damaging. A narrow reactor program using a common fuel form creates a clearer demand signal. A market with many designs, fuel forms, enrichments, geometries, claddings, coolants, and operating conditions creates a harder investment problem. Fuel suppliers are not being asked to serve one standardized fleet. They are being asked to prepare for a moving set of possible reactor futures. If HALEU is a gating condition for deployment, then public policy should be narrowing the field, not celebrating breadth.

This is where U.S. energy policy becomes confused. The United States has a rational nuclear policy layer and a speculative nuclear policy layer. The rational layer is preserving safe existing reactors, extending licenses where appropriate, uprating existing units, restarting recently retired units where the equipment and economics support it, and strengthening the workforce and fuel system. Existing plants have grid connections, trained operators, known safety records, community relationships, cooling systems, and regulatory histories. Keeping a safe reactor operating can avoid large volumes of fossil generation with much less uncertainty than a first-of-a-kind new build.

The speculative layer is treating a fragmented SMR sector as if it were already a deployable answer to new load growth. DOE’s UPRISE initiative, which emphasizes uprates, restarts, license extensions, and improvements to existing reactors, belongs largely in the practical bucket. A $900 million Gen III+ SMR funding opportunity belongs in the option-value and industrial-policy bucket. It may help one or two designs move forward. It may produce learning. But it is not proof that the commercial case exists.

AI has become the new accelerant for this policy story. Data centers want large amounts of firm power, often on fast schedules. U.S. policymakers are concerned about electricity demand growth from AI, data centers, and advanced manufacturing. Nuclear advocates see an opening. The problem is timing. Data centers are being planned and built on two-year to five-year horizons. First-of-a-kind nuclear projects move through design completion, licensing, site work, supply-chain development, fuel procurement, construction, testing, and commissioning on longer timelines. Existing nuclear plants can serve some corporate procurement needs. Restarts and uprates may help in some places. SMRs are not close enough to be the main answer to near-term AI load.

Data centers are a shaky foundation for SMR strategy in any event because the AI electricity panic has already started to look familiar. As I argued in a January 2025 CleanTechnica piece, every wave of digital growth has produced claims that data centers were about to overwhelm the grid, from the dot-com boom to cloud computing, streaming, remote work, blockchain, and now AI. The pattern has been repeated concern, then hardware, software, architecture, and market optimization. U.S. data centers were about 1.5% of electricity consumption in the 2006 EPA report and only about 1.8% in 2014, despite the internet becoming central to daily life. Even with AI, the article noted data centers at about 4.4% of U.S. electricity demand in 2022, material but not world-ending.

Data centers are a shaky foundation for SMR strategy in any event because the AI electricity panic has already started to look familiar. As I argued in a January 2025 CleanTechnica piece, every wave of digital growth has produced claims that data centers were about to overwhelm the grid, from the dot-com boom to cloud computing, streaming, remote work, blockchain, and now AI. The pattern has been repeated concern, then hardware, software, architecture, and market optimization. U.S. data centers were about 1.5% of electricity consumption in the 2006 EPA report and only about 1.8% in 2014, despite the internet becoming central to daily life. Even with AI, the article noted data centers at about 4.4% of U.S. electricity demand in 2022, material but not world-ending.

That is the core policy failure. U.S. SMR policy is confusing aspiration, option value, and industrial strategy with deployment readiness. Policymakers want SMRs to support AI growth, military resilience, export competition, coal-site redevelopment, industrial heat, fuel-cycle rebuilding, and decarbonization before the sector has demonstrated cost, schedule, fuel readiness, repeat construction, or customer depth. That is misguided boosterism. It takes a category that should be treated as a narrow, risky, publicly supported technology option and presents it as if it were a near-term pillar of energy strategy.

Microreactors and remote-site claims should be separated from utility-scale SMRs. Military bases, national laboratories, and research campuses are credible early niches because they have strategic reasons to accept higher cost, unusual risk, and federal procurement structures. Project Pele at Idaho National Laboratory, a 1 MW to 5 MW transportable reactor demonstration for the Department of Defense, fits that category. It is strategic procurement. It is not evidence of normal commercial electricity competitiveness.

Remote communities, mines, and islands are weaker as broad markets. They have real energy problems, including high diesel costs, reliability challenges, fuel logistics, and limited grid access. But the alternatives are improving and being built now. Mines in Western Australia have deployed hybrid systems with solar, wind, batteries, controls, demand management, and gas or diesel backup. Gold Fields’ Agnew project has delivered roughly 50% to 60% renewable energy over the long term. Liontown’s Kathleen Valley project targets more than 60% renewable power from startup. Those systems are modular, financeable, serviceable by normal industrial contractors, and expandable in pieces. They do not require nuclear licensing, nuclear operators, HALEU supply, nuclear waste arrangements, or a nuclear security regime.

The same logic applies to islands and remote communities. Solar, wind where resources are good, batteries, thermal storage, demand response, efficiency, heat pumps, and retained backup can reduce fuel imports and improve resilience without importing the full institutional weight of a nuclear facility. A microreactor may make sense for a sovereign military site, a national laboratory, or a nuclear-capable jurisdiction with a strategic reason to pay for it. That is different from a scalable business model. When an energy technology retreats to remote sites as a leading commercial story, it is often no longer arguing that it is broadly competitive. It is arguing that unusual constraints may hide its disadvantages.

A rational policy would stop treating optionality as progress. If governments believe SMRs are strategically necessary, then they should fund discipline. Pick one or two designs for fleet deployment. Put them at nuclear-capable sites first. Require transparent cost and schedule reporting. Separate first-of-a-kind cost from claimed nth-of-a-kind cost. Tie public support to standardization, real orders, fuel readiness, and repeat construction. Do not count MOUs as demand. Do not pretend that every data-center press release is a reactor order.

Licensing reform can help, but it is not a substitute for a market. The ADVANCE Act and related U.S. efforts to make NRC processes more timely and predictable are reasonable in principle. Regulators should be efficient while maintaining safety and security. But if dozens of designs seek attention, faster licensing does not solve the deeper problem. The bottleneck moves to design maturity, fuel, supply chain, owner capability, financing, construction execution, and public acceptance.

The policy mistake is not supporting any SMR development. Governments often buy option value, and there can be reasons to maintain nuclear engineering capacity, preserve strategic fuel-cycle skills, support a few demonstrations, and keep an export option alive. The mistake is presenting a fragmented, fuel-constrained, thinly ordered technology class as if it were a central answer to near-term electricity demand, AI growth, or industrial decarbonization. That is boosterism, not rational energy policy.

The update to the 2021 conclusion is straightforward. The success conditions have not been met. The sector has not consolidated. The credible projects are getting larger. The real builds are mostly attached to existing nuclear sites, state-backed programs, or strategic industrial contexts. HALEU remains a hard constraint. Remote-site narratives remain niche claims. Small, modular, advanced, factory-built, flexible, and deployable are claims that have to survive contact with licensing, fuel, siting, security, staffing, waste, construction, financing, and repeat orders. Some reactors will likely be built. Some may be useful. But the evidence does not support treating SMRs as a broad, near-term, commercially validated solution. It supports the older and less exciting conclusion that nuclear scale requires focus, standardization, strong institutions, mature fuel supply, and a long program. The SMR sector is still moving in the opposite direction.

May 6, 2026 Posted by Christina Macpherson | Small Modular Nuclear Reactors | Leave a comment