On the safety of nuclear power

Last week I wrote about the possibility of a new generation of small modular reactors, something a number of governments and businesses are betting on as a reponse to climate change and high energy prices. As is often the case, one of the things that came up in discussion was the safety of nuclear power. Is it safe? Can it ever be safe?

While the short answer to those questions is a pretty obvious no, the question ‘is it safe?’ doesn’t get us very far. We are surrounded by unsafe things every day. We learn to use them properly so that the risk is reduced.

Cars are an inherently unsafe technology, and as children we (hopefully) learn to navigate the streets in a way that reduces the risk. Running a pipeline of flammable gas into every house isn’t a safe thing to do, but we know how to run a gas grid responsibly to minimise risk. Even stairs are inherently risky: 700 people a year die from falling down the stairs in the UK alone, and 43,000 people are hospitalised in accidents involving stairs.

I hope this doesn’t sound glib in the context of nuclear power. The point is simply that danger and risk aren’t the same thing. Nuclear power is categorically unsafe. It relies on hugely complex systems handling radioactive material. It’s going to be dangerous. But if we learn from other dangerous things that we nevertheless use, maybe these are two more useful questions:

  • Is nuclear power safer than the alternatives?
  • Are we learning to reduce the risks?

First, we ought to consider nuclear power alongside all the other ways that we generate power. I’ve written about this before, and Our World in Data have helpfully graphed the relevant information.

Nuclear accidents are such vast and terrifying events that they loom large in the imagination – but we’re talking about a small number of very dramatic events. Coal power takes millions more lives than nuclear power does, but without ever making the iconic headlines. It’s attritional and ultimately far more destructive of human lives and wellbeing. Coal power needs to go in the bin.

Because they are so horrifying, it’s easy to overestimate the toll of nuclear disasters. The number of people killed directly by the Fukushima meltdown was zero, rising to one when you include a worker who died of cancer later. Sadly, a further 2,313 people died from heart attacks or disruptions to their medical care as a result of evacuation, which of course happened in the aftermath of an earthquake and a tsunami. Adding these indirect fatalities to the death rates still makes nuclear power 99.9% safer than brown coal.

If you are worried about the safety of energy, campaign against coal.

On the second question then: is the world getting better at managing the risks of nuclear? I mention Fukushima above because it’s the only nuclear accident this century and therefore the most closely studied. They really are quite few and far between. If we look at nuclear accidents over time, a pattern emerges. To illustrate, let me drop in a graph from Visualising Energy.

Of the ten incidents of nuclear meltdown, half happened in the early years of the technology. Lessons are learned, and despite the rapidly rising number of reactors around the world, there is no proportional rise in accidents. There are small incidents that aren’t on the graph, but years pass between serious accidents. After the little remembered failure of the East German Greifswald plant in 1989, it’s 22 years before the next accident at Fukushima – which only happened because a tsunami took out the cooling systems.

The pattern doesn’t tell us that nuclear is safe. What it tells us is that the technology has improved. That reactors are better designed, and those operating them have learned from past mistakes. The nuclear industry has a lot more experience.

This is not a comprehensive answer to the safety of nuclear power, not least because of the waste problem. Neither is it an endorsement of the technology – there are reasons why I advocate for renewable energy, demand management and storage. There are social and economic questions around nuclear power, and the urgency of climate change to keep in mind. But I hope that the points above shed a little light on the specific issue of safety.


  1. I can only comment from the early days of the technology too, as my Dad worked in the industry during the 80’s in Germany. What worries me most about that period was the number of unreported incidents and deaths. I know of at least a dozen leukaemia cases amongst my Dad’s former colleagues. My Dad himself died from a mysterious disease that they couldn’t even name, albeit many years later. During one particular serious incident (a near meltdown) at the Brunsbuettel power plant in the early 80’s, 30 illegal immigrants were sent into the plant to fix a leak. All of them were shortly afterwards deported and presumably died horrible deaths thereafter. None of this was ever reported in the press. All this makes me not want to trust any figures they might release.

    1. That’s sad to hear, and it’s very likely that illnesses and smaller accidents have been under-reported in some places. It still wouldn’t come anywhere near the toll of fossil fuels.

      This is also why transparency is so important in the nuclear industry. Some countries do that better than others. If you can visit your local power station, if it hosts school visits, then it becomes a trusted part of local infrastructure. If it’s all off limits and secret, nobody knows what goes on there and suspicions will abound. It then becomes impossible to make good decisions for or against nuclear power, because you know you’re not being told everything.

  2. Thanks for this thoughtful–and thought-provoking–post. As you mention yourself in the final paragraph, “the waste problem” really deserves a similar-length post of its own. However, I appreciate your weighing of the relative risks of nuclear vs. its alternatives–as you note, for reasons having to do with our innate cognitive biases, it’s easier to see the deaths caused by nuclear disasters than it is to appreciate all the different ways that fossil fuel energy kills people.

    1. It’s a very human thing to confuse danger and risk. People are afraid of flying but not of driving, even though far more people die in car accidents than plane crashes. The terror of a plane crash just looms so much larger in the imagination.

      The waste problem is an interesting one, because it’s not that there aren’t good solutions, but that nobody wants to pay the extraordinary cost of doing things properly. Except Finland – they have the gold standard on nuclear waste, if I remember correctly.

      1. I’ve also read (or maybe heard from Sabine Hossenfelder) that Finland is the gold standard on nuclear waste disposal. I’m curious how Finland has managed to defuse the NIMBYism that is so powerful in every other industrialized democracy.

  3. Trash data presented by the author from 2018 versus fresh data:

    The new record low of atom power in the UK has resulted in a new record low in emissions says UK Grid.

    Fresh statistics:

    March ’23

    March ’22

    March ’21

    March ’21

    For a longer overview:

    1. Not sure what the ‘trash data’ is that you’re referring to, or how your ‘fresh data’ challenges it! Also, if you post more than three links in a post, WordPress holds it as spam – just to let you know.

      I don’t need any convincing about renewable energy. I’ve been writing about nuclear recently because the UK government seems determined to invest in the sector. Overall, articles on renewable energy on this website outnumber articles on nuclear by at least ten to one.

  4. One person died from cancer in Fukushima?
    You should be reported to the press authorities for fake news.

    As far as we know ALL people working in the reactor No. 2 died from cancer.More than 50 …. including the director who forced the staff to destroy their radioactivity metering equipment.

    Over 100.000 killed due to the explosion Chernobyl ….. ?
    The Ukrainian grave yards do not accept evacuees from Chernobyl due to fear that the graves of the locals become polluted.

  5. My objections to nuclear aren’t really to do with a Chernobyl-style accident. It is more to do with the vast inefficiency of the decommissioning process. I live near Sellafield and it is the major employer in the area despite not having produced any energy for decades. I have friends who have worked there for nigh on thirty years and expect to see their careers out there, for another twenty odd years – all for the process of closing it down. Along the way, we’ve had plenty of scandals concerning the processing of waste and dangerous failures that have taken place – including that of dumping unprocessed waste on other countries. It seems an expensive and short term answer that brings much longer term problems with it.

    1. Yes, this is one of the big reasons I advocate renewable energy instead. And what is particularly depressing about decommissioning is the way the costs have been passed on to the taxpayer.

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