The nuclear mirage: why small modular reactors won’t save nuclear power
Small Modular Reactors (SMRs) are the nuclear industry’s latest shiny dream. It is more hope than strategy. SMRs only exist in the imagination of the nuclear industry and its supporters. SMRs can only be found on glossy PowerPoint slides. That is why the Paris-based nuclear consultant Mycle Schneider dubbed SMRs “power point reactors.” There are no engineering plans, no blueprints, no working prototypes.
Still, hope springs eternal, and the idea is to build advanced atomic fission reactors, typically defined as producing up to 300 megawatts of electricity per unit, less than a third the size of a conventional nuclear plant.
The “small” part refers to their reduced output and physical footprint, while “modular” means they’re designed to be built in factories, shipped to sites, and installed as needed, supposedly making them cheaper and faster to deploy than traditional reactors. In theory, you could add modules over time to scale up output, like snapping together Lego blocks.
But let’s not be fooled by the word “small.” Even a single SMR is a massive, highly radioactive industrial machine, capable of powering a mid-sized city and containing a radioactive inventory far greater than the bombs dropped on Hiroshima and Nagasaki.
The “small” label is relative only to the behemoths of the last century. In practice, a “small” reactor brings all the big problems of a conventional reactor: dangerous radioactive fuel, complex safety systems, and the risk of catastrophic failure or sabotage. The only thing that’s truly small about SMRs is their inability to benefit from the economies of scale that, in theory, were supposed to make large reactors affordable — but never actually did.
Rinse, repeat, rebrand
The pitch behind the industry’s push for SMRs is that assembly-line production will ensure quality and lower costs. Assembly lines can replicate flaws just as efficiently as they replicate parts. In the 1970s, I inspected a Chattanooga factory where every reactor vessel had contaminated welds. Six reactors arrived at their sites with factory-induced damage, which limited their lifespans and reduced their efficiency.
Also, consider that every steam generator ever built for U.S. reactors has failed prematurely. Replacement generators have failed, too — sometimes within a year. SMRs will use the same technology, but somehow we’re supposed to believe the outcome will be different this time.
Early prototypes — about the size of today’s SMRs — failed regularly, sometimes catastrophically. The infamous SL-1 reactor in Idaho exploded, killing all three operators. The Wall Street Journal called these plants “Atomic Lemons”— costlier and less efficient than anyone expected.
I’ve witnessed firsthand how unreliable nuclear plants can be. At Millstone Unit 1, where my nuclear industry career began, the plant was shut down for months at a time due to repeated mechanical failures. We’d fix one problem, only to find the same issue cropping up a year later.
Novelty breeds uncertainty. While SMRs and conventional nuclear reactors both fall under the umbrella of atomic reactors, the similarities largely end there. The mechanical and electrical differences between these two concepts are profound, with SMRs introducing a host of new engineering challenges that have not been thoroughly analyzed or experienced in traditional nuclear power plants, potentially offsetting any anticipated benefits and prolonging the path to reliable deployment.
Each of these changes introduces new opportunities for failure — none of them well understood, all of them expensive to fix. SMRs introduce a host of untested problems, including using higher-enriched uranium, close to weapons-grade, raising proliferation and safety concerns.
If anything, their smaller size exacerbates some problems. Because of their compact cores, SMRs can leak more neutrons than conventional reactors, leading to more complex damage to the nuclear reactor itself and different radioactive waste streams — waste that is harder and more expensive to manage and dispose of.
So, despite the “modular” promise, each SMR is still a massive piece of radioactive infrastructure, requiring the same level of security, emergency planning, and long-term waste management as any other nuclear reactor.
Why nuclear can’t compete with renewables
The dream of the first nuclear plants was that mining uranium was a lot cheaper than mining coal. But while nuclear costs continue to rise, wind, solar and battery storage are becoming increasingly cheaper and more reliable every year. And the sun and wind give energy for free. Renewables are now the lowest-cost source of new electricity in most markets. Nuclear, by contrast, has never achieved cost reductions through learning or mass production. Every new design is a new experiment, with new risks and new costs.
Every dollar spent on SMRs is a dollar not spent on proven, less expensive, rapidly deployable renewable energy sources. Worse still, the delays and overruns that have plagued nuclear projects mean that SMRs cannot be built in time to meet urgent climate goals. Meanwhile, wind, solar and storage are already delivering reliable, affordable and clean power to the grid.
The climate crisis demands solutions that are proven, scalable and affordable — qualities that nuclear power, in any form, has never delivered.
After half a century in the nuclear trenches, I can say this with certainty: the latest SMR campaign is not a revolution but a rerun (relapse?). It’s an expensive distraction from the real work of decarbonizing our energy system. The climate crisis demands solutions that are proven, scalable, and affordable — qualities that nuclear power, in any form, has never delivered.
A longer version of this article can be found at https://www.climateandcapitalmedia.com/the-nuclear-mirage-why-small-modular-reactors-wont-save-nuclear-power/.
