The construction of the World's first grid scale nuclear power station - Calder Hall in North East England - was commenced by Taylor Woodrow Construction in 1953 and was officially opened on 17 October 1956, using 1950s engineering and construction techniques..

Originally designed for a life of 20 years from respectively 1956-1959, the plant was after 40 years until July 1996 granted an operation licence for a further ten years.

The station was closed on 31 March 2003, the first reactor having been in use for nearly 47 years.

Seems to me we have gone backwards.

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Always love your work. Thanks for injecting empirical reality into what is too often a political discussion.

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Apr 3, 2023·edited Apr 3, 2023

Thank you for this insightful post. A minor mistake: the UK has not turned its back on big reactors as two more EPRs are in the pipeline at Sizewell.

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Hi. I've recently analysed the reactors built in Europe in the last 25 years, and all of them have issues of cost overruns and delays.

Three "outliers" : Flamanville, Olkiluoto 3 (which you haven't mentioned, about to come online, and having destroyed the contractor AREVA on the process), and Hinckley Point C.

Also, six other reactors that went online in the last years have the same issues.

Plus there have been eight stopped projects, which don't appear in the statistics because of survivor bias.

For Europe (I haven't made the analysis anywhere else), the claims of construction in 6-8 years don't hold.

Plus, I would like to challenge the idea that nations can build them fast when they need them. I think it's more "when they are experienced". This might have been the case for France in the 80's and currently for S. Korea, but it's not the case now for any European company or country.

Here's my full analysis, also taking on the Russian participation in the constructions taking place now in Turkey and Hungary


In any case I share the comments on Prof Flyvbjerg's work

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Apr 4, 2023·edited Apr 4, 2023

Lost of half-truths, lies by omission and outright falsehoods in your article:

You fail to mention that Hinckley Point C would be an example of learning by doing given that construction times are trending towards almost halving those of the other 2 European units of the same type, and in line with those built in China at Taishan.

(By the way, the fact that you don't mention China at all in addition to South Korea is... curious. They're the kings of standardised 5-year builds right now).

You seem to have pulled your Ostrovets €14 billion (?!) overrun out of a hat. It's not coherent with a 2-year delay for unit 2, or with any recent Rosatom project costs. What's your source? Because if it's this one (taken from WNISR, which LOL)


That's 12 billion RUBLES, genius. In 2001 prices. Adjust the 56.1 billion RUB for inflation and it gives you 400 billion RUB in 2023 prices. Convert to USD and the result is... $5 billion (per unit, I assume?) the exact quoted price.

This, incidentally, makes a lot of your analysis in the "Trojan horse" section fall apart, but there are other nonsensical aspects in it regarding energy independence (Akkuyu will produce 10% of Turkey's electricity regardless of the existence of other plants by foreign suppliers) and especially in the environmental part: Short of the Mediterranean boiling over the plant will always get cooling, perhaps with a lower power output during summertime due to Carnot efficiency, and it's located in an area of Turkey with null earthquake risk


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Maybe you have a point, but using this "half-truths, lies by omission and outright falsehoods" is bad style at least! I don't like it. Please get off of assuming bad faith everwhere. This is so annoying.

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Hinckley Point is being built by EDF. From what I've heard from them, they expect to get better at building their *next* plant of similar characteristics: Sizewell C.

I haven't analysed the Chinese plants. I guess that my main question would be the same as for S. Korea, is it possible to replicate the performance under different geographic and cultural setups? Let's see, for instance Poland seems to want to build a S. Korean plant.

For Ostrovets, the source is "Nuclear Geopolitics in the Baltic Sea Region: Exposing Russian Strategic Interests Behind

Ostrovets NPP"


Atlantic Council (2017)

But whatever the figure, it shows how Russia is using nuclear. Do you support the building of Paks in its current form? In other words, does your defense of nuclear imply accepting Russia's role in Paks or Akkuyu?

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Apr 5, 2023·edited Apr 5, 2023

> From what I've heard from them, they expect to get better at building their *next* plant of similar characteristics: Sizewell C.

What I've heard from them is that they want Sizewell C to be 20% faster than HPC 2, which itself is on track to be 20% faster than HPC 1.


(It's somewhere in that presentation)

"Nuclear Geopolitics in the Baltic Sea Region: Exposing Russian Strategic Interests Behind Ostrovets NPP"

Thanks for the source. According to their references they seem to have taken those figures from the 2015 WNISR:

"In March 2015, Atomstroyexport admitted the plant would cost 1,433.7 billion Rubles compared to the forecast from 2014 of 840 billion Rubles. At exchange rates of March 2015, when the Ruble was valued at about half the level of 2014, this equates to an original cost estimate of US$13 billion, increasing by 71 percent to US$22.9 billion" (p. 45)

This claim is unsourced and has been retracted from subsequent editions. The 2022 report reads:

"It is difficult to estimate what the final construction price will be. On the one hand, President Lukashenko has said that cost would be below US$10 billion, but refused to reveal the actual number stating: “It is a commercial secret. The contract price shouldn’t be made public.” Other sources suggest that the cost of the project has increased by 26 percent, to 56 billion Russian rubles [US$750 million] in 2001-prices. The uncertainty of the actual costs is compounded by the high volatility of exchange rates." (p. 362)

Common Mycle Schneider L tbh, including the astounding feat of economic illiteracy (or, more likely, willing dishonesty) that is reporting the unadjusted 2022 USD conversion rate for a projected cost in 2001 RUB.

> Do you support the building of Paks in its current form? In other words, does your defense of nuclear imply accepting Russia's role in Paks or Akkuyu?

I believe every country should be free to pursue their preferred energy and foreign policy objectives. I support Ukraine's fight against an imperialistic Russian state that can't tolerate nations in its old sphere of influence making their own economic and military partnerships; or Finland cancelling Hanhiviki and joining NATO. But I can't fault Hungary and Turkey for pursuing nuclear power with one of the few countries to get Gen 3+ builds right on time and within budget. It's their free choice too.

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It's their free choice and has consequences, which is what I would like to highlight. If 10% of your electricity is in the hands of Russia, then you're not doing energy independence right (Türkiye). If your dependence on Russia for your electricity reduces the scope of the EU sanctions against Russia, then you're not doing support to Ukraine right (Hungary).

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Great research, very useful and well presented as always. A key point about any large development is that its very difficult to pinpoint when works commence. Often complex geotechnical or ground preparatory/infrastructure work takes place on site before or during the regulatory process and this builds into construction. A lot of 'construction' takes place off-site (e.g. pressure vessels) and delays can be due to supply chain issues with these parts.

Also, a point about modular reactors. They may be fast and cheap to build, but they can be inherently inefficient for thermal plants. There is a reason why nuclear (and coal) plants are very large - you need scale for thermal efficiency. This is one of the core reasons why nobody has made modular nuclear viable despite many decades of research.

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I would categorize SMR build-rate and pricing as “unknown” until one of those outfits has shipped ten operating copies of one design.

The global PV business, even accounting for low capacity factor, is adding the equivalent of about 13 BWRX-300’s ... each ... month.

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The equivalent in which respect? Solar panels cannot provide electricity at night and their output during the day varies according to solar flux.

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The distinction you bring up is why I included the capacity factor in the math, which is to say we’re comparing power delivered per interval, not nameplate figures.

If I hadn’t done that, the PV figure would be 24 GW added monthly, not 4.

It will be great news for the NP business if it can approach these build rates.

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Still though, even with the capacity factored in, it still doesn't solve the issue that it's intermittent as most of the power generated for them will usually be concentrated on certain times of the day / year. His point still stands that it isn't stable throughout the day that isn't factored in the equation as energy demand will not adjust to the flux.

You'd still need electricity at night or on really cold winter days where these either won't work or isn't as efficient to fully support the demand needed. This leads to extra costs to compensate by creating massive storage (pumped hydro if geography allows or batteries) or have dispatchable sources like coal / gas peaker plants that often isn't factored into the cost analysis for these.

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My POV is that as far as night time power supply goes, there's two things that can attack the market share of the fossil power sources : nuclear or storage.

Until nuclear shows a build rate that matters, I won't be surprised to see the energy storage industry keep growing.

I've looked at peaker plant data in CA - their capacity factor is about 2%. What that tells me is that yes, they do run sometimes, and no, they don't run for very long. The more efficient CCGT gas plants are 10-20X higher capacity factor.

Even getting nuclear to the rate of 1GW built a month would be interesting!

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Interesting! I didn't know it takes that long. No wonder, retrofitting current plants for better waste disposal is always an issue. I think that is more concerning at the moment. Until we have a clear plan to sort out the nuclear waste, there will forever be a debate in the EU about how green the Nuclear plant is. Here is my article about it: https://www.drgreeneconomy.com/p/green-gas-and-nuclear-could-divide

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Apr 3, 2023·edited Apr 3, 2023

Other sources say Vogtle 3/4 began construction in 2009. Could you address this because obviously it discredits your analysis if your data is inaccurate. If your point is the site began construction in 2009 but the reactors only in 2013 isn’t that misleading? If it takes 4 years to even be ready to commence reactor construction that matters.

The $30b ish cost of Vogtle 3/4 is also relevant, as is £33b for Hinckley C. Cost matters just as much if not more than money.



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Fantastically useful post. Thank you!

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"That gives us lots of opportunity to learn how to do better: this gives them a shot of a better ‘learning curve’ than the large nuclear designs we’ve had in the past."

Just what the world needs, an industry making mistakes and learning on the job. FFS!

Pick a country, any country...


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Thanks for this article. It's nice to see some numerical analysis in the presence of so much political noise.

I'm afraid there's a "But" though.

In your graphs of construction times, you arrange the data always using the date when construction started. This means that for any plant that started build in the 2010s, the longest construction time it could possibly have is 13 years to end in 2023. For a plant started in 2019, it could not be included if its build was longer than 4 years.

Arranging the data like this distorts some of the graphs. In particular, if you were to arrange the green blocks of average construction times by decade using the date the plants entered commercial service rather than the build start date you would see a significant recent trend towards slower builds that I believe your presentation has disguised - especially as regards EU & US builds.

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Thank you for this. I have used and credited your work on build times in my latest article on how to reduce the costs of nuclear power.


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Eye opener - thanks! Definitely linking to this in my next Weekly Climate newsletter 🙏.

Only thing I would love to see is how it stacks up against the same generation capacity for renewable sources (wind, solar, hydro etc). Do you have those numbers?

I guess that’s the relevant comparison to make when people are saying “nuclear is too slow”. 6.5 years is still a long time if you can build the same capacity with wind and solar in 1 year (I have no idea if you can do that just picked a random number).

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Can u tell me what the embedded carbon footprint is of a reactor when construction is completed?

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This is just one of many studies that have been published over recent years and the conclusions share many commonalities. However, construction times haven't improved as a result of those findings either because the planers ignore them, unable to translate the findings into solutions, or the findings aren't relevant to the problem. One thing that these studies haven't considered is the volume of individuals involved in the project which can be a source of miscommunication, conflict, and contradiction.

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