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Smaller nuclear reactors (SMRs) are a costly dead end, especially for AI (2025)

Auteur	Joseph Romm, Ph.D.
	6-01-3-60-20.pdf
Datum	april 2025
Classificatie	6.01.3.60/20 (VEILIGHEID - REACTOREN - REST TYPES, KLEINE REACTOREN (SMR))
Voorkant

Penn Center for Science, Sustainability, and the Media

Smaller nuclear reactors (SMRs) are a costly dead end, especially for AI
Trump’s tariffs and other policies make them even more of a losing bet
Joseph Romm, Ph.D.

Executive Summary
For decades, prices for new nuclear plants kept rising, and they are now the most 
expensive form of power. But solar, wind, and battery prices kept dropping, 
becoming the cheapest. New reactors grew so costly the U.S. and Europe all but 
stopped building any. Nuclear’s share of global power peaked at 17% in the 
mid-1990s but was down to 9.2% by 2022 and 9.1% in 2024. (1)

New reactors are inflationary and lead to higher energy bills for consumers even
if they’re never turned on. The only U.S. plant built in decades, the $35 billion 
Vogtle plant in Georgia, is “the most expensive power plant ever built on earth,” 
with an “astoundingly high” estimated electricity cost. (2)
Georgia ratepayers’ bills are rising by over $220 a year. In 2023, state regulators 
made customers pay for most of the cost of the reactors—“on top of a monthly 
surcharge” (3) they’ve had to pre-pay for years, totaling $1000. (4) South Carolina 
consumers still pay for two never-completed reactors. (5)
Since these 1100-megawatt (MW) reactors are so costly, “small modular reactors” 
(SMRs) under 300 MW have been hyped, especially for AI data centers and 
hydrogen. But SMRs are a dead end—with high risks of cost overruns, delays, and 
reliability/safety problems. That’s why efforts to commercialize them have failed 
for decades. Worse, Trump’s policies “severely increase the risk of expensive, 
unexpected nuclear accidents,” Scientific American warned in March. (6) SMRs 
also have tariff risks since they need foreign sales, foreign uranium, and foreign 
components to succeed.
For decades, reactors have kept getting larger to capture economies of scale. So, 
SMRs face significant shrinkage diseconomies and a higher cost per MW than 
large reactors like Vogtle. Cost escalation is endemic to SMRs (see figure).
So, SMRs would mean even higher rates for consumers than big reactors. In 2025, 
solar, wind, and batteries represent 93% of planned U.S. utility-scale electric 
generating capacity additions. (7) Also, recent studies find advanced geothermal 
energy is on track to provide baseload and potentiallydispatchable power three 
times cheaper to build than Vogtle by 2030.