Small Modular Reactors and the Massive Questions of Price & Waste

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The publication of Kim and Macfarlane’s 2026 research on small modular reactors is a second price pausing over. Nuclear vitality sits on the margins of most critical decarbonization pathways immediately, however SMRs have been marketed because the expertise that would change that. They’re marketed as cheaper, safer, quicker to construct, and simpler to finance than conventional giant reactors. The brand new research, revealed in Progress in Nuclear Power, takes a sober take a look at these claims and finds them wanting. It doesn’t dismiss nuclear energy outright, but it surely asks laborious questions that ought to matter to policymakers, buyers, and utilities deciding whether or not to commit public cash and grid house to SMRs.

The energy of the research lies in who wrote it. Philseo Kim is a researcher centered on nuclear economics and coverage. Allison Macfarlane is a former chair of the U.S. Nuclear Regulatory Fee and one of the credible voices on nuclear waste and governance. Collectively they bring about each technical and coverage lenses. Their prior work, together with a 2022 evaluation of SMR waste streams, already steered that these reactors may produce extra complicated and bigger volumes of waste than typical nuclear vegetation. This paper extends that analysis into each prices and waste, and the image that emerges shouldn’t be encouraging.

On the core of their financial evaluation is the levelized price of electrical energy, or LCOE. This metric aggregates capital, working, and gasoline prices over the lifetime of an influence plant. The authors reviewed estimates for 4 U.S. SMR designs, together with light-water and superior non-light-water ideas. They discovered big uncertainty in the associated fee projections. Some business estimates steered aggressive prices round $60–80 per MWh, however these assumed high-volume serial manufacturing that has by no means materialized in nuclear. Extra practical estimates, and the few real-world initiatives we’ve got seen in Russia, China, and the U.S., level towards prices nicely above $100 per MWh, in some instances multiples of that. The cancellation of NuScale’s flagship undertaking after prices ballooned from $5.3 billion to $9.3 billion is a living proof. The basic drawback is economies of scale. Smaller reactors imply larger prices per unit of output, and solely huge replication may reverse that development. No nation is on observe to construct the a whole bunch of similar models required.

On waste, the findings are even starker. The research exhibits that SMRs may generate two to thirty occasions extra spent gasoline per unit of vitality than immediately’s giant reactors. Their smaller cores leak extra neutrons, which prompts surrounding metal and creates extra long-lived radioactive materials. Some designs produce waste streams which have by no means been dealt with earlier than, akin to irradiated graphite or chemically reactive salts. These would require new packaging, licensing, and repository designs. Over the long run, some SMR fuels are projected to be about 50 p.c extra radiotoxic than typical spent gasoline after 10,000 years. This isn’t the story of simplified waste administration that distributors have been telling.

It is very important acknowledge what the research does and doesn’t declare. It doesn’t predict actual future prices right down to the greenback. It doesn’t assert that each SMR will inevitably fail. What it does is map the vary of uncertainties and level out that many of the elements that would elevate prices and improve waste are structural. Smaller reactors inherently lose the associated fee benefits of scale. Extra unique designs deliver extra unique waste. The most effective case eventualities depend upon optimistic assumptions about mass manufacturing and studying curves, which nuclear building has by no means delivered on. That makes SMRs a high-risk proposition in a world that wants low-cost, fast-to-deploy decarbonization instruments.

Trade responses have been predictable. NuScale and Terrestrial Power have disputed the waste findings, claiming the research used outdated or inaccurate assumptions. Advocates argue that modular building and repetition will ultimately drive prices down. But the precise proof from early initiatives factors within the different route. Russia’s floating SMRs and China’s HTR-PM each got here in a number of occasions over funds and haven’t been replicated. In North America and Europe, SMR initiatives stay on paper or within the very early levels, with business operation unlikely earlier than the 2030s. The research’s authors are cautious to acknowledge the shortage of working knowledge, however they argue persuasively that impartial evaluation is important exactly as a result of distributors usually are not clear about these points.

This work aligns intently with my very own long-standing evaluation of SMRs. The financial logic has at all times been shaky. Nuclear scaled up in dimension over many years as a result of bigger models delivered decrease prices per MWh. Reversing that logic and not using a revolutionary change in manufacturing economics has by no means made sense. The waste issues add one other layer. Nuclear waste is already an unsolved political and technical drawback. Multiplying the quantity and variety of waste streams makes the duty more durable, not simpler. SMRs don’t remedy nuclear’s elementary challenges. They replicate them in smaller packages whereas including new problems.

Globally, the image is constant. Russia and China have the one working SMRs, each over funds and restricted in scale. Argentina’s CAREM reactor is delayed. Canada, the UK, and the U.S. are investing in SMR designs, however none are close to business readiness. Gasoline provide for superior designs is one other bottleneck. Over 30 SMR ideas require high-assay low-enriched uranium, and solely Russia presently produces it at scale. Waste repositories worldwide are designed for typical spent gasoline, not for the brand new waste kinds SMRs would generate. The guarantees of SMRs as quick, modular, and globally deployable haven’t been borne out in apply.

As I used to be discussing with a worldwide, multi-stakeholder analysis group centered on what an actual zero emissions economic system will appear like this morning, for what little nuclear technology we are going to find yourself with — possibly 5% of complete vitality as a result of ideologues will construct it — GW-scale third technology reactors are simply tremendous, assuming that each one the opposite situations of success are met.

The implication for system planning is evident. Decarbonization this decade is dependent upon scaling applied sciences which can be already low cost and quick to deploy: wind, photo voltaic, batteries, interconnectors, demand administration. SMRs, in the event that they succeed in any respect, won’t arrive in significant numbers till the 2030s or 2040s. They could have area of interest roles, however they won’t be a serious wedge in world emissions reductions. Given their price and waste dangers, they need to not crowd out higher-probability choices for near-term deployment. Governments can proceed to fund restricted demonstrations, however public assist ought to be conditional, milestone-based, and tied to clear disclosure of waste and price knowledge.

The publication of Kim and Macfarlane’s research gives a clearer proof base. It’s a reminder that enthusiasm and advertising and marketing don’t erase structural challenges in physics and economics. For policymakers and buyers, the lesson is simple. Don’t assume SMRs will likely be cheaper, quicker, or cleaner than giant reactors. Demand proof on price, waste, and supply earlier than committing important assets. In a world of restricted capital and pressing local weather deadlines, the prudent course is to double down on the applied sciences which can be delivering now and preserve nuclear in a slim take a look at lane with clear cease guidelines.