It would appear to be everybody from enterprise capitalists to the information media to the U.S. secretary of Power has been hyping small modular reactors as the important thing to unlocking a nuclear renaissance and fixing each local weather change and trendy knowledge facilities’ ravenous want for energy.
On Monday, the Pure Sources Committee of the California Meeting will think about a invoice to repeal a longstanding moratorium on nuclear vegetation within the state, which was meant to be in place till there’s a sustainable plan for what to do with radioactive waste. Defeated a number of occasions previously, this invoice would carve out an exception for small modular reactors, or SMRs, the present pipe dream of nuclear advocates.
SMRs are usually beneath 300 megawatts, in contrast with the mixed 2.2 gigawatts from Diablo Canyon’s two working reactors close to San Luis Obispo. These smaller nukes have obtained a lot consideration lately primarily as a result of trendy reactors are so expensive that the U.S. and Europe have all however stopped constructing any.
The unhappy fact is that small reactors make even much less sense than large ones. And Trump’s tariffs solely make the maths extra discouraging.
I’ve been analyzing nuclear energy since 1993, once I began a five-year stint on the Division of Power as a particular assistant to the deputy secretary. I helped him oversee each the nuclear vitality program and the vitality effectivity and renewable vitality program, which I ran in 1997.
So I do know all too effectively that the hype is constructed on quicksand — particularly, a seven-decade historical past of failure. As a 2015 evaluation put it, “Economics killed small nuclear energy vegetation previously — and doubtless will preserve doing so.” A 2014 journal article concluded lots of these “constructing assist for small modular reactors” are placing ahead “rhetorical visions imbued with parts of fantasy.”
However isn’t there a nuclear renaissance occurring? Nope. Georgia’s Vogtle plant is the one new nuclear plant the U.S. has efficiently constructed and began in current a long time. The full price was $35 billion, or about $16 million per megawatt of producing capability — excess of methane (pure fuel) or photo voltaic and wind with battery storage.
As such, Vogtle is “the costliest energy plant ever constructed on Earth,” with an “astoundingly excessive” estimated electrical energy price, famous Energy journal. Georgia ratepayers every paid $1,000 to assist this plant earlier than they even received any energy, and now their payments are rising greater than $200 yearly.
The excessive price of development and the ensuing excessive vitality payments clarify why nuclear’s share of worldwide energy peaked at 17% within the mid-Nineteen Nineties however was right down to 9.1% in 2024.
For many years, economies of scale drove reactors to develop past 1,000 megawatts. The concept abandoning this logic would result in a decrease price per megawatt is magical considering, defying technical plausibility, historic actuality and customary sense.
Even a September report from the federal Division of Power — which funds SMR growth — modeled a value per megawatt greater than 50% larger than for big reactors. That’s why there are solely three working SMRs: one in China, with a 300% price overrun, and two in Russia, with a 400% overrun. In March, a Monetary Instances evaluation labeled such small reactors “the costliest vitality supply.”
Certainly, the primary SMR the U.S. tried to construct — by NuScale — was canceled in 2023 after its price soared previous $20 million per megawatt, larger than Vogtle. In 2024, Invoice Gates advised CBS the total price of his 375-megawatt Natrium reactor could be “near $10 billion,” making its price almost $30 million per megawatt — virtually twice Vogtle’s.
All of this has performed out towards a backdrop of traditionally low-cost pure fuel and a fast growth of renewable vitality sources for electrical energy era. All that competitors towards nuclear energy issues: A 2023 Columbia College report concluded that “if the prices of recent nuclear find yourself being a lot larger” than $6.2 million per megawatt, “new nuclear seems unlikely to play a lot of a job, if any, within the U.S. energy sector.” R.I.P.
SMRs are simply certainly one of a number of wildly overhyped false guarantees on which the world is poised to spend lots of of billions of {dollars} by 2040, together with hydrogen vitality and direct air carbon seize.
However nuclear energy is the unique overhyped vitality know-how. When he was chairman of the Atomic Power Fee, Lewis Strauss — the Robert Downey Jr. character in “Oppenheimer” — predicted in 1954 that our kids would get pleasure from nuclear energy “too low-cost to meter.”
But by the point I joined the Division of Power in 1993, nuclear energy prices had grown steadily for many years. Since then, costs for brand new reactors have saved rising, and they’re now the costliest energy supply. However photo voltaic, wind and battery costs have saved dropping, turning into the most cost effective. Certainly, these three applied sciences represent a exceptional 93% of deliberate U.S. utility-scale electric-generating capability additions in 2025. The remaining is pure fuel.
China is the one nation constructing many new nuclear vegetation over the subsequent 5 years — about 35 gigawatts. Lower than 1% of this projected capability could be from small reactors — whereas greater than 95% will likely be from reactors over 1,100 megawatts. Now examine all that to the 350 gigawatts of photo voltaic and wind China constructed — simply in 2024.
For the U.S., President Trump’s erratic tariffs make small modular reactors a good riskier wager. If the U.S. financial system shrinks, so does demand for brand new electrical energy vegetation. And the dual threats of inflation and better rates of interest enhance the chance of even worse development price overruns.
Additionally, China, Canada and different buying and selling companions present vital provide chain parts wanted to mass-produce SMRs — and mass manufacturing is essential to the gross sales pitch claiming this know-how might develop into reasonably priced. That logic would apply provided that nearly the entire present SMR ventures fail and just one or two find yourself pursuing mass manufacturing.
So, can we please cease speaking about small modular reactors as an answer to our energy wants and get again to constructing the actual options — wind, photo voltaic and batteries? They’re cheaper and cleaner — and really modular.
Joseph Romm is a former appearing assistant secretary of Power and the creator of “The Hype About Hydrogen: False Guarantees and Actual Options within the Race to Save the Local weather.”
