How safe is nuclear energy?

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Nuclear is one of the safest sources of energy.

Various scientific studies find this to be true, comparing the effects of all elements of nuclear energy - mining and refining Uranium, constructing and operating power plants, and the effects of accidents including Chernobyl and Fukushima - with wind, solar, hydro, biomass, fossil fuels etc.

This is no doubt surprising to many people. We are given the impression through newspapers magazines, radio and TV, and social media that nuclear energy is dangerous, because of Fukushima, Chernobyl and Three Mile Island. These are often described as "disasters" or "catastrophes", implying or sometimes claiming that thousands were killed and vast areas left uninhabitable, probably glowing at night with eerie and deadly radiation.

Yet Fukushima and TMI killed nobody, despite multiple reactors melting down. Radiation levels outside the Three Mile Island power plant did not exceed background levels. Even around Fukushima radiation levels were less than normal background levels in some populated parts of the world.

Chernobyl did kill people: 46 confirmed deaths, mostly from radiation sickness and thyroid cancer[1], maybe 4000 or so more[2], decades later, from cancers — if our more pessimistic assumptions about low level radiation are correct (which they may not be). And the evacuated zone, now largely free of human activity, is a teeming wildlife paradise[3].

But the Chernobyl accident involved a design of reactor which would never have been allowed to be built outside the former Soviet Union, built and operated in a culture which prevented learning from mistakes[4], and the accident occurred when most of its safety systems had been deliberately disabled in order to run an experiment on the reactor, which was being operated by a night shift crew who didn't properly understand what they were doing.

And that was the worst nuclear disaster ever.

For comparison, during the same period that we've had nuclear power, aeroplane crashes have claimed tens of thousands of lives[5], but we don't have activists and politicians calling for air travel to be shut down, or aeroplanes to be replaced by airships. Nor are there calls for cars to be replaced by horses and carts, despite the carnage on our roads.

We are told that nuclear waste is an enormous problem and that it has to be isolated from the environment for hundreds of thousands of years. But the fact is that the dangerous isotopes are the shorter-lived ones, like Caesium 137, which have half-lives of a few decades and which decay to harmless background levels in a few centuries. Even without long term repositories the massively-thick stainless steel casks used to store spent fuel at power stations provide safe containment for decades, if not centuries, to come. And we can build safe, long-term repositories, as Finland is demonstrating.

The other concern people cite is proliferation: the idea that having nuclear power stations makes it easier for a country to build nuclear weapons. Actually if anything it makes it harder; Uranium fuel for nuclear power stations is far too poorly enriched to use for weapons, and modern power station reactors are quite unsuitable for breeding Plutonium for weapons. And countries which acquire nuclear power stations have to submit to inspections to ensure they are not attempting to develop weapons. History shows that nuclear-armed countries acquired weapons before they developed nuclear power or - like Israel and North Korea - haven't developed nuclear power at all.

No form of energy is entirely safe

Deaths per TWh - Markandya and Wilkinson.png

People are killed by accidents working on wind turbines and solar panels. The world's single worst disaster at a power generation plant claimed 171,000 lives and made 12 million homeless: it involved a renewable energy generator[6].

But whilst wind, solar, nuclear and hydro can be dangerous when they go wrong, fossil fuels and some renewables kill people when they go right. Quite apart from climate change, the air pollution from burning coal, oil, gas and biomass (officially classified as renewable) causes sickness and death. If we add up all the deaths from accidents (large and small) and from air pollution, we can compare different energy sources[7]:

Nuclear energy is saving millions of lives

We can work out how many premature deaths due to air pollution were prevented by using nuclear instead of coal. Climate scientist and activist James Hansen and his colleage Pushker Kharecha did this in 2013 and calculated that world-wide, between 1971 and 2009, almost 5,000 people were killed by nuclear power, but more than 1.8 million people would have been killed by the coal-burning that nuclear replaced[8]. By the late noughties almost 80,000 lives a year were being saved, so by now well over 2 million people have been saved from early deaths thanks to nuclear energy.

Energiewende is killing thousands of people a year

Germany's "Energiewende" (Energy Transition) involves closing down the country's nuclear power stations. Germany used to get a quarter of its electricity from nuclear but now gets only 12%, whilst it gets 40% of its electricity from coal: mostly Lignite[9], the dirtiest form of this already dirty fuel. If Germany had kept all its nuclear power stations running it could burned less Lignite instead, and got only 27% of its electricity from coal instead of 40% — that's a third less than it now does.

What difference would that have made?

how many deaths German coal burning causes in neighbouring countries (from Dark Cloud report)

Germany's coal burning kills 4,350 people every year in Europe - 230 of those in the UK[10][11]. At least one-third of those - 1,450 lives - are due to Germany's nuclear shut-down. (Probably more, since if Germany had not shut down nuclear power stations it could preferentially have shut down Lignite ones rather than those burning the slightly less polluting black coal.) In the UK that's about 80 citizens being killed every year by Germany's anti-nuclear policy.

Footnotes and references

  1. See IPCC WG3 assessment report 5, Chapter 7: Energy Systems, page 550
  2. "Health effects of the Chernobyl accident: an overview", World Health Organisation, April 2006
  3. "“What About Radioactive Wastelands?” A Look at Chernobyl’s Effects on Nature", Iida Ruishalme, Thoughtscapism, 8 May 2019
  4. "A Viewer's Guide to HBO's Chernobyl Miniseries", Matt Wald, Nuclear Energy Institute, 1 May 2019
  5. "Aviation accidents and incidents: Bureau of Aircraft Accidents Archives (B3A)", Wikipedia
  6. Banquaio Dam, Wikipedia
  7. "What is the safest form of energy", Our World In Data
  8. "Prevented Mortality and Greenhouse Gas Emissions from Historical and Projected Nuclear Power", Pushker A. Kharecha and James E. Hansen, Environmental Science & Technology, 15 Mar 2013
  9. "Nuclear Power in Germany", World Nuclear Association, Updated March 2019
  10. "Coal-burning EU countries make their neighbours sick", WWF, 5 Jul 2016
  11. "Europe's dark cloud: how coal-burning countries are making their neighbours sick", Climate Action Network Europe, HEAL, Sandbag, WWF, local copy