Congratulations, one of your very best columns. I appreciate your wish to cite the 1969 hit record, I’m The Urban Spaceman. But subsequent generations may be more familiar with a story written by Hans Christian Andersen from Denmark, concerning the small boy who alone was not taken in by the King’s much vaunted new clothes, declaring that the King was in fact naked. That seems thoroughly pertinent regarding SMR hypes.
I'm rather sceptical on these promises on paper. The whole concept of a modular reactor system isn't new either. The AGR design at Heysham A & Hartlepool was specifically designed to be factory built. But never got past those two prototypes.
Wow. Somehow you conveniently skipped over GE-Hitachi's BWRX-300 currently under construction in Ontario for Ontario Power - a proper commercial model. It is a First of its Kind and 3 more are in line to be constructed - with the first one scheduled to come online by 2030 or so. Alberta and Saskatchewan are also in line to construct this.
So feel free to speak for yourself when you practically dismiss SMRs as a gimmick - but reality says otherwise.
There’s nothing under construction! Just press releases. If one does get completed then regret will set in, and nothing more than press releases will follow
Like I said, feel free to speak for yourself. Construction on that site has been going on for about a year now under a site preparation permit. The full construction will be starting this month under a full construction permit. All of this is publicly available information that can be found with minimal effort.
And you want to categorically declare that the whole thing will be a regret when you have literally no skin in the game, sure go ahead - just know that you are speaking for yourself, and not for the ground reality.
Also, see my commentary at the bottom of the post which I have just added - Darlngton is heading to be the most expensive nuclear power station per GW ever built
Considering you do not seek to be properly informed, let me inform you that actual foundation construction is already well underway at the site - under a construction permit no less. But again, it is not like facts really matter for those who have already made up their minds.
Excellent and true article. I worked in the 60s at the uk atomic energy site which designed and developed nuclear reactors. At least one reactor had progressed to the final stage of supplying a fair amount of electricity to the National Grid for quite a few years with no problems. However it was decided to go ahead with the large size reactors and stop development of the various different types being researched even though some of them again had gone to quite a sophisticated level. What most people seem to have missed is that in the future we are going to need the best load power generation capability that is climate change invariable and also available all the time. Also able to produce huge amounts of gigawatts with a pretty reasonable long life. With these characteristics it's is likely to be expensive but that's not the point is it. there is not an alternative to nuclear power and we should be building as many as we can.
I find your take on this article surprising. Maybe I am missing something, but isn't the author saying the opposite? Many different designs have been tried, and most dropped. Building any nuclear reactor is very expensive and takes a long time. There simply isn't enough time and expertise (and funding) available to build many of them, regardless of relative size. It's a dead end. As for climate invariable - where are most nuclear power stations located? On the coast. Is the coast going to be impacted by climate change? Yes. How? It's going to move inland, sometimes by many miles. Also, more storms and storm surges massively increase the risk to existing NPS sites, requiring much more expensive mitigation (see Hinkley C). So, costs rise even further. It's a spiral of despair.
You are wrong. At uk winfrith nuclear development site in the 1960s several small to medium reactors were developed and one brought to full grid supplying for many years. Large reactors were chosen instead but that was purely political.. how do i know? I was a research phycisist with lab inside one of the reactor buildings. The site contained about 20 nuclear reactors in development or for research into more advanced versions.
Firstly the uk built quickly two different successful reactors classified as small relative to the huge ones currently being buit. Neither expensive nor took a long time. Plus a successful fast breeder. And easy to replicate these. I know because I worked at the uk reactor develooment site. Neither needs to be near water. So your answer is totally incorrect. Research winfrith, sghwr and dragon
Sghwr 100mw provided power to the grid for 23 years 650mw variant also designed as scale up. We could be building lots now.
A successful fast breeder? Dounreay was closed in 1998 after multiple problems. You're missing the key arguments in my post about the relative diseconomies of scale of smaller nuclear power plant.
Rubbish it successfully supplied the grid for 15 years. It was shut down for political reasons. We should have several now greatly helping with our power problems.
So only a VERY small part of cost (and cost overruns) is driven by material cost (concrete, steel etc).
There are 2 main reasons for the astronomic cost of NPP:
1. An appalling lack of project control, especially over engineering. What idiot starts construction, before even the basic design is approved (Olkiluoto 3). Endless rework, redesign and other delays drive up finance cost (remember the 67%).
2. Strategic misrepresentation. Deliberately under-budgeting the project, because both the principal and the contractor want the project to be approved. Knowing they will not be on the hook for the inevitable cost overruns. The tax payer will be.
The only way to reduce the cost of nuclear, is to change the project delivery.
In such a way, that it does not take 15 years from FID till commissioning.
When you succeed in doing this, you target those 67%, and not the 11%.
But the conclusion remains the same.
SMR will not solve the problem, the propagandists claim it will solve.
It's just like with transformers. No matter whether it's a 3 KVA or a 75 KVA.
The working principle and the complexity are identical. Just the size differs.
A SMR (no matter what definition) is no less complex than a large PWR.
The material cost per output unit are higher. But that is the 11%.
Only when you would build assembly-ready modules off-site, would it be possible to exclude engineering creativity, and thus reduce cost.
But this all depends on unit cost reductions, for which you need sufficient total output.
I’d go in a slightly different direction. SMRs are interesting for grid operators that want to retire coal plants but want clean energy. SMRs are a potential answer by providing dispatchable power from extant centralized hubs while operating carbon free.
So the comparison shouldn’t be on the basis of a nuclear power plant vs. gas peakers or renewables, rather it should be the total cost of the plant and the marginal benefit of being able to site dispatchable power in extant brownfields without the need for infrastructure upgrades and being able to make use of extant power infrastructure.
As the experience in Iberia last month illustrated, having inertia in the net is quite beneficial as generators that just follow can make the grid very brittle. Especially if you can only import 3% of your grid needs like in Iberia.
Now how to make the economics work is a different matter. So far, few markets seem to have cracked the nut re: how to make use of solar/wind while pricing in the benefit of reliable power.
I’d also add that economies of scale are more likely to occur in an industry where hundreds of SMRs are made every year, not one large plant every decade.
As for the need for ultra specialized gear, regulations, etc. I have relatively little sympathy for that. Operators have time and time again shown themselves to be extremely lax re: common sense (ie siting nukes and gensets in a known tsunami area of impact) and most of these regulations were written by the industry itself.
You want cheap nuclear power? I suggest the French EdF has perhaps a pretty convincing answer that supplies over 70% of the French power needs: standardization. Makes construction and later maintenance much easier than the unicorns the rest of the west keeps putting up.
As I argue in my post, SMRs are a throwback to an age when smaller nuclear power were abandoned because they cost more than large ones. So inasmuch as we'll get any SMRs over the next few years (very few I'd guess) they'll turn out to be so expensive that the idea will eventually be abandoned. There's lots of ways of getting more inertia in systems that are a lot cheaper and much quicker to deploy.
Agreed. SMRs are not expected to be deployed at scale until the 2030s or beyond, which is too late to meet 2030 climate targets. Renewables, storage, and demand-side measures are already deployable and cost-effective today.
While SMRs are being heavily promoted, particularly by governments and nuclear industry players, their high costs, slow timelines, and unproven scalability make them a high-risk and potentially distracting solution compared to rapidly advancing clean energy technologies.
I don’t disagree re: costs. The overruns in more recent years have been astronomical. The only reason we have LIPA in its present form is a nuke and Cuomo.
…but that’s where SMRs may offer an out via standardization and avoiding the costly change orders that dogged many of the large plants built in more recent years. Ie creating a standardized format may allow the collection of learning benefits much like EdF did with its fleet.
As for inertia, no doubt. Whether is flywheels like the one they are building in Ireland, or fat interconnects to willing adjoining iso grids (ie looking at you, Germany) there are ways to do it.
I still think SMRs have a place, especially in context of helping secure grid stability on a local basis vs. relying so much on imports like my location does. How to value said reliability is another matter, however.
Arguably, they are learning. EPR2 is a simpler design, has a smaller scope of components, is easier to build. But it’s precisely the regularity of nukes to run grossly over budget that makes them so uneconomical in most markets.
You don’t have the same scale problem with gas peakers. They are well understood and generally have few installation issues. That’s the benefit of scale and learning - both at the manufacturing stage as well as on site preparation and integration.
The fever dream of SMR proponents is to wring similar efficiencies both in construction and siting if scales increase enough. Time will tell.
The Chinese have an experimental high temperature molten salt Thorium Reactor producing energy. They are now constructing a larger version. You do not mention TerraPower, the Bill Gates/ Hitachi collaboration molten salt reactor. This is a genuine SMR in that they have plans to mass produce them after the first one is built and working. With these modern designs the whole idea is that by the laws of physics it is impossible to melt down, so you do not need the concrete protection of a traditional reactor. They should therefore be much cheaper to build. The TerraPower reactor is to be 325 MW which is big by the standards of the 1950s. This is a good not a bad thing.
there have been experimental molten salt reactors before. There's nothing new about this and no reason to think it is at all 'cheap'. It will still have to follow the same safety rules of other nuclear reactors
Yes molten salt reactors were developed the 1980s, but there is a lot new. In the same way wind energy has been used for hundreds of years, but a modern wind turbine is much more efficient than a windmill In a tulip field. The whole purpose of the TerraPower design is to use passive safety (i.e. using gravity and the laws of physics) rather than a lot of concrete and humans turning dials. This design is far safer than the gen 3 reactors such as Vogtle and Hinkley Point 3. I agree with you just building a small version of a traditional reactor is pointless and likely more expensive than a large one, but this is not what TerraPower and the Chinese are doing.
Wind power was developed in 5000 BC. Solar electricity was generated around 1900. What matters is how it is developed now. The Chinese recently tested one of their next gen reactors with a total power shut down (that is no cooling as happened by accident at Fukushima). As the science tells us it should, the reactor just stopped. The billions Gates and the other investors have put into TerraPower is on the assumption they can build reactors cheaply.
If these reactors do not exist then why are so many cargo ships and war ships powered by them. it is growing power train. Russia is opening up new trade routes using them.
The latest generation of sodium-cooled fast reactors (SFRs), often referred to as Generation IV designs, are designed to use significantly less concrete and steel compared to earlier nuclear reactors (like many light water reactors, LWRs). This reduction comes from several key design and operational advantages:
1. Operating at Atmospheric Pressure (or very low pressure):
* Sodium's High Boiling Point: Liquid sodium has a very high boiling point (around 880°C or 1616°F) compared to water (100°C or 212°F at atmospheric pressure). This means SFRs can operate at much higher temperatures without the need for the extremely high pressures seen in water-cooled reactors.
* No Massive Pressure Vessels: Water-cooled reactors, especially Pressurized Water Reactors (PWRs), require massive, thick-walled steel pressure vessels to contain the high-pressure water. This vessel is a major component demanding significant steel. Because SFRs operate at low pressure, they don't need such heavy-duty pressure vessels, leading to a substantial reduction in the required steel.
* Simpler Piping and Structures: The lower operating pressures also mean that the piping and other primary circuit components don't need to be as robustly built to withstand high internal pressure, further reducing steel requirements.
2. Excellent Heat Transfer Properties of Sodium:
* High Thermal Conductivity: Sodium is an excellent conductor of heat, much better than water. This means it can transfer heat away from the reactor core very efficiently.
* Compact Core Design: Because heat can be removed so effectively, the reactor core itself can be much more compact for a given power output. A smaller core means a smaller overall reactor vessel, and consequently, less concrete and steel needed for the containment and surrounding structures.
* High Power Density: The efficient heat transfer allows for a higher power density in the core, meaning more power can be generated from a smaller physical footprint.
3. Enhanced Passive Safety Features:
* Natural Circulation: The latest SFR designs are often built with enhanced passive safety systems that rely on natural physical phenomena (like natural circulation of the coolant) to remove decay heat in accident scenarios, rather than relying heavily on active, powered pumps and cooling systems.
* Inherent Shutdown Mechanisms: Some SFR designs incorporate inherent reactivity feedback mechanisms, where the reactor naturally slows down if temperatures rise too high.
* Reduced Need for Active Safety Systems: Because passive safety features are designed to handle many accident scenarios without human intervention or external power, the need for complex, redundant, and robust active safety systems (which require significant concrete and steel for their housing and support) is reduced. This simplifies the plant design and reduces the amount of materials needed for safety-related structures.
* Pool-Type Design: Many modern SFRs use a "pool-type" design where the entire primary coolant system (reactor core, pumps, heat exchangers) is contained within a single large vessel of liquid sodium. This design offers advantages in terms of leak prevention and containment, and it can reduce the need for extensive external piping and associated concrete support structures.
4. Modular Construction and Simplified Architecture:
* Prefabrication and Modularity: Newer designs often emphasize modular construction, where large components are fabricated off-site in factories and then assembled at the plant. This can lead to more efficient use of materials and less on-site construction time and complexity, which indirectly reduces the overall demand for raw materials like concrete and steel.
* Decoupled Structures: Some designs aim to "decouple" and simplify major structures, leading to a less interconnected and massive overall plant.
In essence, the combination of sodium's unique properties (high boiling point, excellent heat transfer) allowing for low-pressure, high-temperature operation, along with advanced passive safety designs and a focus on modularity, enables the latest generation of sodium-cooled reactors to achieve a more compact, inherently safer, and therefore materials-efficient design.
after all the failed promises of the nuclear power constructors in the past and the failure of previous attempts at even these technologies, we shouldn’t give much credence to what is written in PR handouts!
Of course there have been no cancellation and failed promises of renewable projects - not!
Numerous wind farm projects across Europe have been cancelled or stalled in recent years due to a variety of factors, including rising costs, higher interest rates, supply chain issues, permitting delays, grid connection bottlenecks, military concerns, and local opposition.
Here's a list of notable cancelled wind farm projects in Europe, with a focus on recent instances and significant capacity:
Offshore Wind Farms:
* Hornsea 4 (UK): Ørsted, the world's largest offshore wind farm developer, decided to discontinue this massive 2.4 GW project in its current form in May 2025. The cancellation was attributed to significant increases in supply chain costs, higher interest rates, and increased risks associated with construction and operation.
* Omø Syd (Omø South) (Denmark): European Energy ceased the development of this offshore wind project in January 2024. The project had been under development for over ten years, and its processing was suspended by the Danish Energy Agency due to EU law issues.
* Danish 3 GW Offshore Wind Tender (Hesselø, Kattegat II, and Kriegers Flak II) (Denmark): Denmark cancelled a major 3 GW offshore wind tender in January 2025 after receiving no bids for the projects. This was largely due to high costs and uncertain earnings.
* Boreas (UK): Swedish developer Vattenfall halted this 1.4 GW project in 2023 due to rising costs.
* Swedish Offshore Wind Projects (13 projects, ~32 GW total capacity) (Sweden): In November 2024, the Swedish government cancelled 13 offshore wind projects in the Baltic Sea, citing national security concerns related to military defense. This decision impacted developers such as OX2, Eolus, Ørsted, RWE, Freja Offshore, Deep Wind Offshore, and Statkraft. The cancelled projects included:
* Arkona
* Aurora
* Baltic Offshore Beta
* Baltic North Offshore Delta
* Cirro
* Hinchar
* Erik Segersäll
* Neptune
* Pleion
* Ski Blades
* Skåne Offshore Wind Farm
* South Victoria
* Triton
Onshore Wind Farms:
* Mont des Quatre Faux (France): In April 2025, the Nancy Administrative Court of Appeal revoked the permit for this 226 MW project, which would have been the largest onshore wind farm in France. The cancellation was primarily due to concerns about the visual impact of the 63 wind turbines.
* Various projects in the Netherlands: Dozens of potential onshore wind projects in the Netherlands have been cancelled, delayed, or put on hold due to protests and lack of local support.
* Projects in Norway: New project approvals were paused for three years in Norway due to protests, though the government has now resumed issuing permits with municipal agreement.
* Markbygden Ett (Sweden): While this is a completed and operational wind farm, it's worth noting that its power purchase agreement (PPA) with Hydro Energi was voluntarily cancelled in October 2024, resulting in a significant compensation payment, due to the project having lost hundreds of millions of euros since its start-up.
General Reasons for Cancellations Across Europe:
* Soaring Costs: Increased material costs, inflation, and higher interest rates have made large-scale wind projects less economically viable.
* Supply Chain Issues: Constraints and increased costs within the supply chain for components and services.
* Permitting Delays: Slow and complex permitting processes in many European countries, often not aligning with new EU rules.
* Grid Connection Bottlenecks: Insufficient grid infrastructure and long waiting queues for connecting new wind farms to the electricity grid.
* Lack of Demand/Funding: In some cases, projects struggle to secure demand for the generated power or fail to obtain necessary funding.
* Local Opposition: Public resistance based on visual impact, noise concerns, and environmental worries, particularly for onshore projects.
* Military Concerns: National security considerations, as seen in Sweden, can lead to the cancellation of projects in strategically important areas.
* Market Design Issues: Fragmented markets, negative electricity prices, and distorted market signals can undermine the financial viability of projects.
This list is not exhaustive, as project statuses can change and new cancellations may occur. However, it highlights some of the significant and recent examples of cancelled wind farm projects in Europe.
A quite brilliant dissection of the SMR myth. Here at STAND (Severnside Together Against Nuclear Development https://www.nuclearsevernside.co.uk) we are fighting the development of 4 or 6 "SMR"s on the River Severn. Our research and experience over the last 45 years has led us to exactly the same conclusions about SMRs as you, but you have encapsulated the arguments so cogently and succinctly. A recent poll showed that in spite of the fact that the official Green Party line is anti-nuclear power, 40% of Green party members are pro-nuclear. We will be attending a local meeting of the Green Party on Thursday, where pro Nuclear speakers have been invited, and your article gives us some excellence ammunition to counteract the disinformation that I know we will be hearing.
There was an article in the Eastern Daily Press today talking about IMSR (Integral Molten Salt Reactor) at the Bacton site. Maybe in 2030s. It was a confusing article.
Great article David! Sounds like they are looking for a marriage proposal by putting lipstick on that old piglet.
Congratulations, one of your very best columns. I appreciate your wish to cite the 1969 hit record, I’m The Urban Spaceman. But subsequent generations may be more familiar with a story written by Hans Christian Andersen from Denmark, concerning the small boy who alone was not taken in by the King’s much vaunted new clothes, declaring that the King was in fact naked. That seems thoroughly pertinent regarding SMR hypes.
Good read - will this hype be short lived - but people are making “money” to suggest SMR as silver bullet for everything
I'm rather sceptical on these promises on paper. The whole concept of a modular reactor system isn't new either. The AGR design at Heysham A & Hartlepool was specifically designed to be factory built. But never got past those two prototypes.
Wow. Somehow you conveniently skipped over GE-Hitachi's BWRX-300 currently under construction in Ontario for Ontario Power - a proper commercial model. It is a First of its Kind and 3 more are in line to be constructed - with the first one scheduled to come online by 2030 or so. Alberta and Saskatchewan are also in line to construct this.
So feel free to speak for yourself when you practically dismiss SMRs as a gimmick - but reality says otherwise.
There’s nothing under construction! Just press releases. If one does get completed then regret will set in, and nothing more than press releases will follow
Like I said, feel free to speak for yourself. Construction on that site has been going on for about a year now under a site preparation permit. The full construction will be starting this month under a full construction permit. All of this is publicly available information that can be found with minimal effort.
And you want to categorically declare that the whole thing will be a regret when you have literally no skin in the game, sure go ahead - just know that you are speaking for yourself, and not for the ground reality.
Site preparation should not be mistaken for construction.
Also, see my commentary at the bottom of the post which I have just added - Darlngton is heading to be the most expensive nuclear power station per GW ever built
Considering you do not seek to be properly informed, let me inform you that actual foundation construction is already well underway at the site - under a construction permit no less. But again, it is not like facts really matter for those who have already made up their minds.
Excellent and true article. I worked in the 60s at the uk atomic energy site which designed and developed nuclear reactors. At least one reactor had progressed to the final stage of supplying a fair amount of electricity to the National Grid for quite a few years with no problems. However it was decided to go ahead with the large size reactors and stop development of the various different types being researched even though some of them again had gone to quite a sophisticated level. What most people seem to have missed is that in the future we are going to need the best load power generation capability that is climate change invariable and also available all the time. Also able to produce huge amounts of gigawatts with a pretty reasonable long life. With these characteristics it's is likely to be expensive but that's not the point is it. there is not an alternative to nuclear power and we should be building as many as we can.
I find your take on this article surprising. Maybe I am missing something, but isn't the author saying the opposite? Many different designs have been tried, and most dropped. Building any nuclear reactor is very expensive and takes a long time. There simply isn't enough time and expertise (and funding) available to build many of them, regardless of relative size. It's a dead end. As for climate invariable - where are most nuclear power stations located? On the coast. Is the coast going to be impacted by climate change? Yes. How? It's going to move inland, sometimes by many miles. Also, more storms and storm surges massively increase the risk to existing NPS sites, requiring much more expensive mitigation (see Hinkley C). So, costs rise even further. It's a spiral of despair.
You are wrong. At uk winfrith nuclear development site in the 1960s several small to medium reactors were developed and one brought to full grid supplying for many years. Large reactors were chosen instead but that was purely political.. how do i know? I was a research phycisist with lab inside one of the reactor buildings. The site contained about 20 nuclear reactors in development or for research into more advanced versions.
Firstly the uk built quickly two different successful reactors classified as small relative to the huge ones currently being buit. Neither expensive nor took a long time. Plus a successful fast breeder. And easy to replicate these. I know because I worked at the uk reactor develooment site. Neither needs to be near water. So your answer is totally incorrect. Research winfrith, sghwr and dragon
Sghwr 100mw provided power to the grid for 23 years 650mw variant also designed as scale up. We could be building lots now.
A successful fast breeder? Dounreay was closed in 1998 after multiple problems. You're missing the key arguments in my post about the relative diseconomies of scale of smaller nuclear power plant.
Rubbish it successfully supplied the grid for 15 years. It was shut down for political reasons. We should have several now greatly helping with our power problems.
I worked for the ukaea on reactor development.
Before more are built, solve the waste problem. We can't protect the human genome from increasing loads of radioactivity.
Excellent write-out.
Unfortunately this is about 1.234.567 times too long for the attention span of the nuclear propagandist. But very useful to refer to.
On important point though, on the cost.
78% of the total lifecycle cost of a NPP is fixed.
11% is overnight capital cost (mostly material cost).
67% of cost of financing.
See this figure (nuclear energy agency)
https://blog.policy.manchester.ac.uk/wp-content/uploads/2022/10/Figure-1-PNG-1-768x502.png
So only a VERY small part of cost (and cost overruns) is driven by material cost (concrete, steel etc).
There are 2 main reasons for the astronomic cost of NPP:
1. An appalling lack of project control, especially over engineering. What idiot starts construction, before even the basic design is approved (Olkiluoto 3). Endless rework, redesign and other delays drive up finance cost (remember the 67%).
2. Strategic misrepresentation. Deliberately under-budgeting the project, because both the principal and the contractor want the project to be approved. Knowing they will not be on the hook for the inevitable cost overruns. The tax payer will be.
The only way to reduce the cost of nuclear, is to change the project delivery.
In such a way, that it does not take 15 years from FID till commissioning.
When you succeed in doing this, you target those 67%, and not the 11%.
But the conclusion remains the same.
SMR will not solve the problem, the propagandists claim it will solve.
It's just like with transformers. No matter whether it's a 3 KVA or a 75 KVA.
The working principle and the complexity are identical. Just the size differs.
A SMR (no matter what definition) is no less complex than a large PWR.
The material cost per output unit are higher. But that is the 11%.
Only when you would build assembly-ready modules off-site, would it be possible to exclude engineering creativity, and thus reduce cost.
But this all depends on unit cost reductions, for which you need sufficient total output.
Wright's law, aka experience curve.
https://en.wikipedia.org/wiki/Experience_curve_effects
Paul Martin wrote an excellent article on LinkedIn, where he explained that the required number of cumulative output, will NEVER be attained.
https://www.linkedin.com/pulse/scaling-examples-pt-1-small-modular-nuclear-reactors-smnrs-martin
To conclude
1. Material cost is not the fundamental cause of the demise of nuclear
2. SMR will not save nuclear; because it is the umpteenth version of the emperor's clothes
the figures quoted at the bottom of my post comparing Darlington and Flamanville 3 are pure overnight costs, nothing else
I’d go in a slightly different direction. SMRs are interesting for grid operators that want to retire coal plants but want clean energy. SMRs are a potential answer by providing dispatchable power from extant centralized hubs while operating carbon free.
So the comparison shouldn’t be on the basis of a nuclear power plant vs. gas peakers or renewables, rather it should be the total cost of the plant and the marginal benefit of being able to site dispatchable power in extant brownfields without the need for infrastructure upgrades and being able to make use of extant power infrastructure.
As the experience in Iberia last month illustrated, having inertia in the net is quite beneficial as generators that just follow can make the grid very brittle. Especially if you can only import 3% of your grid needs like in Iberia.
Now how to make the economics work is a different matter. So far, few markets seem to have cracked the nut re: how to make use of solar/wind while pricing in the benefit of reliable power.
I’d also add that economies of scale are more likely to occur in an industry where hundreds of SMRs are made every year, not one large plant every decade.
As for the need for ultra specialized gear, regulations, etc. I have relatively little sympathy for that. Operators have time and time again shown themselves to be extremely lax re: common sense (ie siting nukes and gensets in a known tsunami area of impact) and most of these regulations were written by the industry itself.
You want cheap nuclear power? I suggest the French EdF has perhaps a pretty convincing answer that supplies over 70% of the French power needs: standardization. Makes construction and later maintenance much easier than the unicorns the rest of the west keeps putting up.
As I argue in my post, SMRs are a throwback to an age when smaller nuclear power were abandoned because they cost more than large ones. So inasmuch as we'll get any SMRs over the next few years (very few I'd guess) they'll turn out to be so expensive that the idea will eventually be abandoned. There's lots of ways of getting more inertia in systems that are a lot cheaper and much quicker to deploy.
Agreed. SMRs are not expected to be deployed at scale until the 2030s or beyond, which is too late to meet 2030 climate targets. Renewables, storage, and demand-side measures are already deployable and cost-effective today.
While SMRs are being heavily promoted, particularly by governments and nuclear industry players, their high costs, slow timelines, and unproven scalability make them a high-risk and potentially distracting solution compared to rapidly advancing clean energy technologies.
I don’t disagree re: costs. The overruns in more recent years have been astronomical. The only reason we have LIPA in its present form is a nuke and Cuomo.
…but that’s where SMRs may offer an out via standardization and avoiding the costly change orders that dogged many of the large plants built in more recent years. Ie creating a standardized format may allow the collection of learning benefits much like EdF did with its fleet.
As for inertia, no doubt. Whether is flywheels like the one they are building in Ireland, or fat interconnects to willing adjoining iso grids (ie looking at you, Germany) there are ways to do it.
I still think SMRs have a place, especially in context of helping secure grid stability on a local basis vs. relying so much on imports like my location does. How to value said reliability is another matter, however.
Well the EPRs being constructed by EDF are supposed to be standardised as well. That’s not gong well.
Arguably, they are learning. EPR2 is a simpler design, has a smaller scope of components, is easier to build. But it’s precisely the regularity of nukes to run grossly over budget that makes them so uneconomical in most markets.
You don’t have the same scale problem with gas peakers. They are well understood and generally have few installation issues. That’s the benefit of scale and learning - both at the manufacturing stage as well as on site preparation and integration.
The fever dream of SMR proponents is to wring similar efficiencies both in construction and siting if scales increase enough. Time will tell.
The Chinese have an experimental high temperature molten salt Thorium Reactor producing energy. They are now constructing a larger version. You do not mention TerraPower, the Bill Gates/ Hitachi collaboration molten salt reactor. This is a genuine SMR in that they have plans to mass produce them after the first one is built and working. With these modern designs the whole idea is that by the laws of physics it is impossible to melt down, so you do not need the concrete protection of a traditional reactor. They should therefore be much cheaper to build. The TerraPower reactor is to be 325 MW which is big by the standards of the 1950s. This is a good not a bad thing.
there have been experimental molten salt reactors before. There's nothing new about this and no reason to think it is at all 'cheap'. It will still have to follow the same safety rules of other nuclear reactors
Yes molten salt reactors were developed the 1980s, but there is a lot new. In the same way wind energy has been used for hundreds of years, but a modern wind turbine is much more efficient than a windmill In a tulip field. The whole purpose of the TerraPower design is to use passive safety (i.e. using gravity and the laws of physics) rather than a lot of concrete and humans turning dials. This design is far safer than the gen 3 reactors such as Vogtle and Hinkley Point 3. I agree with you just building a small version of a traditional reactor is pointless and likely more expensive than a large one, but this is not what TerraPower and the Chinese are doing.
There have been molten salt reactors since the 1950s eg https://www.osti.gov/biblio/4237975
Wind power was developed in 5000 BC. Solar electricity was generated around 1900. What matters is how it is developed now. The Chinese recently tested one of their next gen reactors with a total power shut down (that is no cooling as happened by accident at Fukushima). As the science tells us it should, the reactor just stopped. The billions Gates and the other investors have put into TerraPower is on the assumption they can build reactors cheaply.
I cannot see how molten salt can be made "safe" or efficient in the long run. Pipes corrode - will they do so less in high temperature liquid salt?
Apparently this has been solved by Terra Power using a different compound for the piping utilizing Austenitic stainless steels.
If these reactors do not exist then why are so many cargo ships and war ships powered by them. it is growing power train. Russia is opening up new trade routes using them.
There have been nuclear submarines since the 1950s. As I explain this is not a new concept as is being promoted
The latest generation of sodium-cooled fast reactors (SFRs), often referred to as Generation IV designs, are designed to use significantly less concrete and steel compared to earlier nuclear reactors (like many light water reactors, LWRs). This reduction comes from several key design and operational advantages:
1. Operating at Atmospheric Pressure (or very low pressure):
* Sodium's High Boiling Point: Liquid sodium has a very high boiling point (around 880°C or 1616°F) compared to water (100°C or 212°F at atmospheric pressure). This means SFRs can operate at much higher temperatures without the need for the extremely high pressures seen in water-cooled reactors.
* No Massive Pressure Vessels: Water-cooled reactors, especially Pressurized Water Reactors (PWRs), require massive, thick-walled steel pressure vessels to contain the high-pressure water. This vessel is a major component demanding significant steel. Because SFRs operate at low pressure, they don't need such heavy-duty pressure vessels, leading to a substantial reduction in the required steel.
* Simpler Piping and Structures: The lower operating pressures also mean that the piping and other primary circuit components don't need to be as robustly built to withstand high internal pressure, further reducing steel requirements.
2. Excellent Heat Transfer Properties of Sodium:
* High Thermal Conductivity: Sodium is an excellent conductor of heat, much better than water. This means it can transfer heat away from the reactor core very efficiently.
* Compact Core Design: Because heat can be removed so effectively, the reactor core itself can be much more compact for a given power output. A smaller core means a smaller overall reactor vessel, and consequently, less concrete and steel needed for the containment and surrounding structures.
* High Power Density: The efficient heat transfer allows for a higher power density in the core, meaning more power can be generated from a smaller physical footprint.
3. Enhanced Passive Safety Features:
* Natural Circulation: The latest SFR designs are often built with enhanced passive safety systems that rely on natural physical phenomena (like natural circulation of the coolant) to remove decay heat in accident scenarios, rather than relying heavily on active, powered pumps and cooling systems.
* Inherent Shutdown Mechanisms: Some SFR designs incorporate inherent reactivity feedback mechanisms, where the reactor naturally slows down if temperatures rise too high.
* Reduced Need for Active Safety Systems: Because passive safety features are designed to handle many accident scenarios without human intervention or external power, the need for complex, redundant, and robust active safety systems (which require significant concrete and steel for their housing and support) is reduced. This simplifies the plant design and reduces the amount of materials needed for safety-related structures.
* Pool-Type Design: Many modern SFRs use a "pool-type" design where the entire primary coolant system (reactor core, pumps, heat exchangers) is contained within a single large vessel of liquid sodium. This design offers advantages in terms of leak prevention and containment, and it can reduce the need for extensive external piping and associated concrete support structures.
4. Modular Construction and Simplified Architecture:
* Prefabrication and Modularity: Newer designs often emphasize modular construction, where large components are fabricated off-site in factories and then assembled at the plant. This can lead to more efficient use of materials and less on-site construction time and complexity, which indirectly reduces the overall demand for raw materials like concrete and steel.
* Decoupled Structures: Some designs aim to "decouple" and simplify major structures, leading to a less interconnected and massive overall plant.
In essence, the combination of sodium's unique properties (high boiling point, excellent heat transfer) allowing for low-pressure, high-temperature operation, along with advanced passive safety designs and a focus on modularity, enables the latest generation of sodium-cooled reactors to achieve a more compact, inherently safer, and therefore materials-efficient design.
after all the failed promises of the nuclear power constructors in the past and the failure of previous attempts at even these technologies, we shouldn’t give much credence to what is written in PR handouts!
Of course there have been no cancellation and failed promises of renewable projects - not!
Numerous wind farm projects across Europe have been cancelled or stalled in recent years due to a variety of factors, including rising costs, higher interest rates, supply chain issues, permitting delays, grid connection bottlenecks, military concerns, and local opposition.
Here's a list of notable cancelled wind farm projects in Europe, with a focus on recent instances and significant capacity:
Offshore Wind Farms:
* Hornsea 4 (UK): Ørsted, the world's largest offshore wind farm developer, decided to discontinue this massive 2.4 GW project in its current form in May 2025. The cancellation was attributed to significant increases in supply chain costs, higher interest rates, and increased risks associated with construction and operation.
* Omø Syd (Omø South) (Denmark): European Energy ceased the development of this offshore wind project in January 2024. The project had been under development for over ten years, and its processing was suspended by the Danish Energy Agency due to EU law issues.
* Danish 3 GW Offshore Wind Tender (Hesselø, Kattegat II, and Kriegers Flak II) (Denmark): Denmark cancelled a major 3 GW offshore wind tender in January 2025 after receiving no bids for the projects. This was largely due to high costs and uncertain earnings.
* Boreas (UK): Swedish developer Vattenfall halted this 1.4 GW project in 2023 due to rising costs.
* Swedish Offshore Wind Projects (13 projects, ~32 GW total capacity) (Sweden): In November 2024, the Swedish government cancelled 13 offshore wind projects in the Baltic Sea, citing national security concerns related to military defense. This decision impacted developers such as OX2, Eolus, Ørsted, RWE, Freja Offshore, Deep Wind Offshore, and Statkraft. The cancelled projects included:
* Arkona
* Aurora
* Baltic Offshore Beta
* Baltic North Offshore Delta
* Cirro
* Hinchar
* Erik Segersäll
* Neptune
* Pleion
* Ski Blades
* Skåne Offshore Wind Farm
* South Victoria
* Triton
Onshore Wind Farms:
* Mont des Quatre Faux (France): In April 2025, the Nancy Administrative Court of Appeal revoked the permit for this 226 MW project, which would have been the largest onshore wind farm in France. The cancellation was primarily due to concerns about the visual impact of the 63 wind turbines.
* Various projects in the Netherlands: Dozens of potential onshore wind projects in the Netherlands have been cancelled, delayed, or put on hold due to protests and lack of local support.
* Projects in Norway: New project approvals were paused for three years in Norway due to protests, though the government has now resumed issuing permits with municipal agreement.
* Markbygden Ett (Sweden): While this is a completed and operational wind farm, it's worth noting that its power purchase agreement (PPA) with Hydro Energi was voluntarily cancelled in October 2024, resulting in a significant compensation payment, due to the project having lost hundreds of millions of euros since its start-up.
General Reasons for Cancellations Across Europe:
* Soaring Costs: Increased material costs, inflation, and higher interest rates have made large-scale wind projects less economically viable.
* Supply Chain Issues: Constraints and increased costs within the supply chain for components and services.
* Permitting Delays: Slow and complex permitting processes in many European countries, often not aligning with new EU rules.
* Grid Connection Bottlenecks: Insufficient grid infrastructure and long waiting queues for connecting new wind farms to the electricity grid.
* Lack of Demand/Funding: In some cases, projects struggle to secure demand for the generated power or fail to obtain necessary funding.
* Local Opposition: Public resistance based on visual impact, noise concerns, and environmental worries, particularly for onshore projects.
* Military Concerns: National security considerations, as seen in Sweden, can lead to the cancellation of projects in strategically important areas.
* Market Design Issues: Fragmented markets, negative electricity prices, and distorted market signals can undermine the financial viability of projects.
This list is not exhaustive, as project statuses can change and new cancellations may occur. However, it highlights some of the significant and recent examples of cancelled wind farm projects in Europe.
They don’t cost anything
A quite brilliant dissection of the SMR myth. Here at STAND (Severnside Together Against Nuclear Development https://www.nuclearsevernside.co.uk) we are fighting the development of 4 or 6 "SMR"s on the River Severn. Our research and experience over the last 45 years has led us to exactly the same conclusions about SMRs as you, but you have encapsulated the arguments so cogently and succinctly. A recent poll showed that in spite of the fact that the official Green Party line is anti-nuclear power, 40% of Green party members are pro-nuclear. We will be attending a local meeting of the Green Party on Thursday, where pro Nuclear speakers have been invited, and your article gives us some excellence ammunition to counteract the disinformation that I know we will be hearing.
thanks!
Nuscale Power Corp has a market cap of $5bn. Are you saying it’s all hot air?
I didn't bother mentioning NuScale as it has failed in its planned development, see https://www.utilitydive.com/news/nuscale-uamps-project-small-modular-reactor-ramanasmr-/705717/. I'm not going to comment on how and why people decide to invest their money in ventures like NuScale - but I wouldn't!
Yes they have given up...
Last Energy. I looked it up.
What it does: 35110 - Production of electricity; 35300 - Steam and air conditioning supply
Who it’s owned by: Last Energy Inc, described as a start-up October 2024 by Reuters
Mini company, so audited accounts not needed. Has a deficit of £1.2m
Has been going since November 2021
DESNZ would give it £40m?
Probably not!
There was an article in the Eastern Daily Press today talking about IMSR (Integral Molten Salt Reactor) at the Bacton site. Maybe in 2030s. It was a confusing article.