There is a renewed push for nuclear energy globally as it is low-carbon and so it is included in most planning scenarios for net zero, the argument often being that it can provide a consistent base load in contrast to the variability of renewables like solar and wind. But sustainable development consultant Ran Boydell makes the case that nuclear energy is essentially a dumb technology.
We tend to assume nuclear energy must be rocket science and so, despite being aware of the negatives, give it the benefit of the doubt in terms of the role it could play as part of our decarbonised energy future. But nuclear energy is dumb energy. Here’s how it actually works.
Nuclear power plants comprise two separate parts, commonly referred to as the nuclear island and the conventional island.
“Nuclear reactors are, fundamentally, large kettles”
The nuclear island is where the nuclear reactor is located – the genuine rocket science part – but this isn’t where the electricity is produced. All that happens in the nuclear island is that the heat given off by the nuclear reaction is captured to boil water and generate steam. Literally, that is the sole desired outcome. As noted by the World Nuclear Association: “nuclear reactors are, fundamentally, large kettles”.
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The steam is transferred to the conventional island, where it is used to drive traditional steam turbines, and it is these very conventional beasts that generate the electricity.
Steam turbine technology for electricity was first patented in 1884 when Charles Parsons demonstrated the effect at a shipyard in Newcastle – in that case coal supplying the heat. This technology is used largely unchanged in all modern thermodynamic power stations. The use of steam to create mechanical force, the primary energy transition, can be traced back to ancient Greece, so it’s about as far removed from rocket science as you can get.
The similarity of the process to fossil fuel power stations is explained succinctly by nuclear-power.com, a site that promotes greater public understanding about nuclear energy, when it states that: “since conventional power plants (such as fossil-fuel power plants) use very similar technology to convert thermal energy into electrical energy, this part of the nuclear power plant is called the conventional island.”
In short, nuclear energy uses technology from the mid-20th century, which was ground-breaking at the time but is now old hat. It does nothing more than generate heat, in preference to getting that heat from burning fossil fuels or biomass or tapping into solar or geothermal sources, which in turn is used to power some industrial revolution era technology. Is that really the best we can do to generate electricity in the 21st century?
The fact that we have discovered how to control and manipulate the nuclear reaction is a demonstration of humanity’s incredible capacity for science and technology, but that doesn’t mean it is always an appropriate technology to use.
Nuclear medicine, amazing! Nuclear weapons, dreadful! Nuclear submarines are probably an appropriate use of the technology, given the onerous operational constraints. But nuclear energy, just plain dumb.
Many countries have well-established nuclear energy systems, and there are valid reasons why these should be maintained, perhaps even expanded, but should we even be considering its use elsewhere? Nuclear energy was a headline campaign issue for the conservative Liberal/National Coalition during the Australian federal election in May 2025, and whilst they lost the election decisively, they are still holding onto it as a core part of their net zero policy. Yes, it’s low carbon, but is it appropriate?
Here are six technical reasons why not
Using a nuclear reaction to heat water and make steam is like driving a Maserati for the school run
1. Nuclear energy is a high-tech answer to a low-tech need
Managing a nuclear reaction is an incredibly complex science at the molecular level, with the power to amaze us by its use in medicine to save lives or by its massive explosive force in warfare.
Using a nuclear reaction to heat water and make steam is like driving a Maserati for the school run: an exercise in constraining the power that is desperately wanting to be released. By comparison, generating electricity using steam turbines is low grade technology, very low grade.
As noted before, it was first demonstrated by Charles Parsons in 1884, which in turn was based on Michael Faraday’s electric dynamo of 1831, whilst the core principles can be traced to Benjamin Franklin’s observations of 1751. Turn a wheel with magnets inside a wire coil, and electricity is produced, simple.
Wind turbines are a much better match to that demand: wind blows, blades turn, electricity is generated. Same for hydro electricity. Solar power is the real rocket science of the 21st century, where energy from sunlight is directly absorbed by the semiconductor material in the panels to create an electron flow, with no moving parts, no waste, no fuel supply logistics, no additional steps in the energy conversion process.
2. Nuclear energy is no more energy efficient than other comparable sources
The efficiency of converting heat, the primary energy, into electricity is roughly the same for nuclear as it is for fossil fuel plants, around 33 per cent; that is, only one third of the energy is captured, whilst two thirds is wasted. This is unsurprising as they all rely on essentially the same steam turbine systems. By comparison, wind turbines can get up to 60 per cent efficiency, and hydro is 90 per cent in converting mechanical energy into electricity.
3. Nuclear energy is very inflexible
Nuclear reactors run at constant high output 24/7, meaning a lot of off-peak generation is wasted. Whilst the industry is promoting how the design of plants can allow for more flexibility in the future, such as with smaller modular units, there are substantial technical limitations on how operational output can be controlled, especially in response to unscheduled peaks and troughs in demand. This is the opposite of what is needed to balance the variable output from renewables, and the answer for both is that better storage solutions are what we really need to capture excess generation.
4. Nuclear energy is a security risk
Energy infrastructure is always a potential target of attack, just look at the devastation being caused in Ukraine, but nuclear energy facilities can be turned from a target into a weapon. If breached, whether by direct hit or by sabotage of their operating systems, they present the risk of radioactive contamination across vast swathes of a country’s land and population. As the world seems to be becoming increasingly unstable politically, this risk cannot be ignored.
5. Nuclear energy leaves a prolonged, highly toxic inheritance
We all know how toxic the nuclear process is through all stages of its lifecycle, from the processing and transportation of the uranium fuel through the operational life of the plant and then the storage of the radioactive waste. But do we clock how long that inheritance lasts? Thousands of years, perhaps millions of years. Even just the decommissioning of a plant can take more than 20 years; that’s a whole human generation. And that’s just the standard operational process, let alone things going wrong, as demonstrated by the catastrophic events at Fukushima and Chernobyl.
6. Nuclear energy is expensive
It is an established fact that wind and solar are now by far the cheapest form of energy generation to build globally. Nuclear is three or four times the cost, and gas peaking plants are similar. Coal and standard gas plants are somewhere in the middle. In most countries where nuclear is being built today it relies on government subsidies or consumer price guarantees to make them financially viable. Nuclear is definitely not the answer to energy’s role in the cost of living crisis.
Nuclear energy is subject to all sorts of wild card problems just like every technology…
Four reactors at France’s Gravelines nuclear power plant were shut down late Sunday due to a swarm of jellyfish in the cooling systems, operator EDF said on Monday, likely due to rising water temperatures because of global warming.
https://www.reuters.com/business/energy/swarm-jellyfish-shuts-french-nuclear-plant-2025-08-11/
However, Nuclear energy is undergoing rapid research transformation. We need a more powerful energy grid as the new technology, e.g AI and its application in society, is energy-hungry and solar and wind will never be able to supply the eye-watering amount of energy required. It is probable that nuclear fusion power plants are not far off. Portable nuclear power plants are already in production and have been used in close proximity to their recipient needs,e.g. Massive data centres churning out the electronic technology – no transmission lines needed. All of this is already happening.
If AI companies want to use nuclear that is their choice, as with the recent recommissioning of Three Mile Island by Microsoft, but not sure we can rely on them to manage the long term waste.
I am not persuaded that nuclear fusion will be working any time soon, but it’s a whole different scenario as it doesn’t have the radioactive waste or risk. We definitely need a different energy system in between fossil fuels and fusion.
“not sure we can rely on them to manage the long term waste.”
The next step after cool-down on site should be consolidated interim storage. It would make no sense for operators for be responsible for managing their own waste inside such a facility. After interim storage, a fuel processor could remove the uranium and non-radioactive fission products (and a few usable radioactive ones) to cut the “waste” mass by more than 98%. Then the residue could be vitrified and shaped to fit sequestration canisters, and then borehole operators could place the canisters very deep, and there’s no reason each step of the operation could not be managed by specialists in that step, with management responsibility passed on from stage to stage.
“I am not persuaded that nuclear fusion will be working any time soon,”
Getting it working looks like a trivial challenge compared to making it cheap.
“it’s a whole different scenario as it doesn’t have the radioactive waste or risk.”
One of the major fugitive isotopes from conventional fission reactors is tritium. It is slippery stuff and can migrate right through many metals. But where a gigawatt-scale fission plant typically holds less than 1 gram of tritium, a D-T fusion reactor of similar scale would have a normal operating inventory of around 55 kg. D. Jassby did an overview of some rarely-mentioned problems in “Fusion reactors: Not what they’re cracked up to be” for the Bulletin of the Atomic Scientists.
“Steam turbine technology for electricity was first patented in 1884”
First photovoltaic cell –1883, by Charles Fritts.
“The use of steam to create mechanical force, the primary energy transition, can be traced back to ancient Greece, so it’s about as far removed from rocket science as you can get.”
First known use of wind to create force–around 3500 BCE.
First windmills–between 500 and 900 CE.
First rockets–somewhere in the Song dynasty (960-1279)
“In short, nuclear energy uses technology from the mid-20th century, which was ground-breaking at the time but is now old hat.”
Electric cars use technology that dates back to the 1830’s.
“It does nothing more than generate heat,”
Yeah, like fire. Which hominids have been using for at least a million years. And yet, we are still coming up with new ways to use fire. Indeed, fire is the literal basis for rocket science.
“Is that really the best we can do to generate electricity in the 21st century?”
There are many meanings of “best”. All technology that we actually use is, in some way, the best we can do–until we come up with something better.
“nuclear energy, just plain dumb.”
That’s like saying electricity is dumb. There are definitely dumb ways to use electricity, but that doesn’t mean electricity itself is dumb.
“1. Nuclear energy is a high-tech answer to a low-tech need”
That’s the same argument which was made against smart phones. You don’t hear that argument much any more.
“Managing a nuclear reaction is an incredibly complex science at the molecular level,”
At the management level, it’s: insert control rod–reactions decrease; withdraw control rod–reactions increase. Or, with molten salt fast reactors, the expansion of the salt itself regulates the reaction (more expansion, less reaction).
“2. Nuclear energy is no more energy efficient than other comparable sources… only one third of the energy is captured, whilst two thirds is wasted.”
With hotter Gen 4 reactors, that “waste” heat is also hotter, which makes it more practical to use it for other purposes. And some reactors are being built only to provide industrial heat.
“3. Nuclear energy is very inflexible…Nuclear reactors run at constant high output 24/7, meaning a lot of off-peak generation is wasted. … better storage solutions are what we really need to capture excess generation.”
With hotter reactors, the same molten salt thermal storage that works for solar thermal power can be used for nuclear power. With storage and an up-rated generator, the reactor could run flat out all the time while the plant has variable output. And such a plant would actually need intermittent wind and solar to carry the load at times to give it a chance to recharge the thermal tanks. And heat storage is much cheaper and simpler than electron storage.
“4. Nuclear energy is a security risk… If breached… they present the risk of radioactive contamination across vast swathes of a country’s land and population.”
The leading Gen 4 design in the U.S. will use Triso fuel suspended in molten salt. Breach the reactor and the liquid salt and fuel balls will flow out of the reactor into a non-critical configuration and will soon freeze solid in the relatively cold outer environment. The security risk would be much greater for municipal water supplies, grid infrastructure, chemical refineries, petroleum refineries, natural gas depots, fertilizer plants, pipelines, chemical or fuel rail tanker cars, passenger rail, rail stations, airports, airplanes, ferries, cruise ships, supertankers, tall buildings, government buildings, bridges, tunnels, stadiums, theaters, restaurants, hotels, nightclubs, schools, hospitals, malls, parades, concerts, military bases, and postal and package delivery services–all of which would be vastly easier and more effective targets.
“5. Nuclear energy leaves a prolonged, highly toxic inheritance…do we clock how long that inheritance lasts? Thousands of years, perhaps millions of years.”
Most of today’s spent fuel (95%) is just uranium. And yeah, uranium will always be unhealthy to eat. But uranium has always been abundant in the natural environment (billions of tonnes in the oceans, tens of trillions of tonnes on land). The only unavoidable radioactive products of fission are the fission products themselves. More than 80% of fission products will be cold and stable in around 10 – 20 years. The only significant long term hazard comes from cesium 137 and strontium 90–which become a thousandfold less radioactive each 300 years. By 500 years, the hazard level drops below routine natural radiation.
“6. Nuclear energy is expensive…It is an established fact that wind and solar are now by far the cheapest form of energy generation to build globally.”
And that became a fact only recently–following decades of wind and solar being far too expensive to compete. But we invested in supporting and improving wind and solar when they weren’t competitive–which many people thought was a dumb idea at the time–and that investment eventually paid off. Some of the new kinds of nuclear have tremendous potential to be cheaper than old-tech nuclear, but they too will probably need some help right at first. Also, energy and electricity are not the same thing. Wind and solar can provide industrial heat by converting electricity to heat, but heat is the native mode for nuclear, so its relative cost effectiveness roughly triples for heat applications.
I do not dispute any of the facts the commentator presents. There is nothing inherently right or wrong about facts (unless they are “alternative facts” that we seem to be getting a lot of nowadays). We all use facts to support or deny a particular point of view, and my point of view about nuclear energy is that it’s “dumb” in terms of the meaning from dictionary.com as “lacking intelligence or good judgment” or just plain “stupid”.
I was prompted to take this point of view by the fact that we are using the incredible science and technology involved in managing a nuclear reaction to do nothing more than boil water. In the 1950s it no doubt seemed like a very clever thing to do, but for society to continue to promote its use in the 2020s shows a decided lack of “good judgement”.
Like I said above, I do not dispute the facts presented and so won’t try to refute the many points made, apart from no.1 – this is not in any way the same argument that was made against smart phones. Using a smart phone to make a phone call is using a much more complicated piece of technology than necessary for that task, but they can do so much more than just make phone calls. Old fashioned mobile phones were made “smart” by the addition of computer technology to enable access to a huge range of services. They opened up opportunities we didn’t know we needed or wanted.
Nuclear energy is “dumb” because it is still just boiling water, it hasn’t given us anything new or anything we can’t get from other sources. It’s like using a Motorola DynaTAC instead of the latest iPhone – sure we can make a phone call on either of them, but it’s pretty obvious which of them is of more value to society in the 21st century.
We make choices as a society about which activities we promote and which we discourage, and these choices determine what our future will look like. As individuals our influence is small compared to governments, corporations or those with big money, but we can still make our point of view known. The direction of our future energy system is one of the biggest choices we are under pressure to make at the moment. We need to juggle carbon emissions and other environmental impacts as well as rising energy demand and how to optimise the use of existing infrastructure against the positive and negative legacy we leave future generations, and I just think we have so many better options than nuclear energy on all those counts.
“we are using the incredible science and technology involved in managing a nuclear reaction to do nothing more than boil water.”
Reactivity management is basically inserting or withdrawing control rods to obtain the desired heat output. That hardly seems incredible. Steam turbine technology is more complicated than that. It also seems peculiar to try to make this argument against fission power while being open to fusion power–which would use vastly more complex and expensive reactors to, again, boil water.
Also, we can and will do other things with nuclear heat than generate electricity.
“this is not in any way the same argument that was made against smart phones.”
I definitely remember this being a criticism of smart phones when they first came out.
“they can do so much more than just make phone calls.”
Many features have been added since they first came out. I’m expecting a similar gain of function with Gen 4 reactors.
“it hasn’t given us anything new or anything we can’t get from other sources.”
Also true of wind power and solar PV. All they do is push electrons, and we definitely had other ways of doing that before they came along. But nuclear-powered ships and subs arguably were something new. And old-tech civilian nuclear power gave us a non-combustion way to generate electricity without the location constraints which limited hydropower and geothermal (a feature wind and solar later duplicated–with less reliability). It also gave us the means to consume the bomb fuel from 20,000 nuclear warheads–unlike any other power source we have. But yes, it hasn’t given us anything new lately, because we’re still using old-tech nuclear. And Gen 4 nuclear hasn’t given us anything new because it isn’t here yet. But just because a service isn’t new, that doesn’t make it worthless or dumb.
“We need to juggle carbon emissions”
We’ll need to do a lot more than that.
“and other environmental impacts”
The environmental impacts of reservoir hydropower are far worse than for nuclear.
“as well as rising energy demand”
Which is still outstripping the growth in renewable generation.
“and how to optimise the use of existing infrastructure”
We have something like 1.4 billion internal combustion vehicles in service (plus combustion-powered boats and ships, aircraft, and billions of small motors). With nuclear-produced hydrocarbon fuels to replace fossil fuels, all those vehicles, engines, and motors, and the entire fuel delivery infrastructure could be converted to clean energy without significant modification.
“against the positive and negative legacy we leave future generations, and I just think we have so many better options than nuclear energy on all those counts.”
For me, a big legacy issue is planetary heating (and ocean acidification). If all we do is discontinue fossil fuel use and switch to clean energy, the result will be accelerated heating. That is because somewhere between a third to half of our warming potential is being masked by solar dimming from combustion particulates. Once we lose the shading effect from all that smog, the skies will clear, we’ll get the full brunt of the sun, and the pace of heating will accelerate, and that will last for centuries if we don’t aggressively draw down CO2 levels in the air. But with hotter reactors, we can use the secondary heat for that purpose. We already know how to do direct-from-air CO2 extraction at an efficiency of between 1.5 and 2 MWh(th) per tonne of CO2. So a 200 MW(e) air-cooled Gen 4 plant could sequester around a million tonnes of CO2 per year at that efficiency, just using the “waste” heat and the air motion created by the cooling fans. 100k such plants could pull around 100 gigatonnes of CO2 out of the air per year, and if we could use that to achieve a net reduction of, say, 30 gigatonnes per year, we could effectively claw back all surplus CO2 over pre-industrial levels in around 40 years. We could also use nuclear heat to produce sodium hydroxide to combat ocean acidification directly.
And in addition to synthetic fuel production and CO2 drawdown, we could also use nuclear heat for pyrolysis and use radiation cross-linking to greatly improve plastic recycling, and for industrial heat, for steady data-center power, for chemical processing, fertilizer production, isotope production, water desalination (or nuclear ships could move very large fresh-water bladders by sea), district heating, and thermal energy storage. And with molten salt fast reactors, we’ll be able to consume our supply of old-tech spent fuel, and our depleted uranium, and in the process leave following generations a legacy of energy abundance (just the “spent” fuel holds more energy than we’ve ever gotten from fossil fuels), which could also help lift billions out of energy poverty. And this energy abundance will also let us shrink the human footprint on nature–by displacing fuel crops, by letting us restore river systems and migratory fish runs, by increasing our trend towards urbanization, by reducing our fertility rate (a usual effect in high-energy societies), and by supporting area-dense but energy-hungry food systems, such as aquaponics and cellular food production.
That list of features and benefits is likely to grow to include things I haven’t even imagined at this point, but just those few items are enough for me to conclude that there can be smart ways to use nuclear energy. There are, of course, also dumb ways to use it. We should avoid doing those.