According to the IPCC, the carbon intensity (emissions per unit energy generated) of nuclear power is very low, and similar to that of wind power. Even this low level of intensity arises from the present use of fossil fuels to create the equipment necessary to convert the low-carbon energy. Therefore, as fossil fuels are phased out we can expect even lower intensities in the future, both from nuclear and renewables.
In conventional energy scenarios, nuclear power and renewables are usually given equal billing and assumed to be complementary. Yet very few buy this 'both and' view. Discussion has become dramatically polarised.
The battle lines over energy are usually set, and people rarely change sides. This is particularly true for wind power and nuclear power, where people who support one often oppose the other. Unfortunately the 'acquired phobias' that emerge tend to cloud rational debate, so it is doubly important for campaigners of all kinds to calm down and try to get inside the skins of their 'opponents'.
In this spirit I wrote the following piece for an official energy magazine in 2005. I was then working at CAT and it caused no end of trouble for the poor Media Department, who tried hard to get me sacked. This illustrates the firmness of the battle lines.
A Devil's Pact? [.doc]
A more detailed exploration of the pros and cons of nuclear and renewables is found in the next item, which I drafted with my colleague Paul Allen, although it was never published. What some people deplored, but others found refreshing, was the neutral tone in which we spoke about various options. It is customory among supposedly green organisations to incorporate a kind of textual shudder in any sentence dealing with nuclear energy, but here we tried to treat everything with dispassionate consideration, and this in itself seemed shocking in some quarters.
SOME FURTHER COMMENTS
Unlike most so-called greens I do not have any 'acquired phobia' about nuclear power. I am not horrified by it. This is an important distinction, because for many people radioactivity is not only physically dangerous but generates a genuine revulsion. It is a kind of 'ritual pollution' more like that of pork for observant Jews and Muslims: they feel especially disgusted and contaminated. I do not share this.
Possibly this is due to routine use of radioactive tracers in biological research that I undertook in the sixties. As with medical X-rays I could see that, appropriately used, radioactivity could be both useful and safe. In the seventies I became friendly with the late John Fremlin of the University of Birmingham, who was 'Professor of Applied Radioactivity'. Not surprisingly he was a strong proponent of nuclear energy and introduced me to the scientific literature on all aspects of the field. I always tried to rely on the best quality of evidence, while maintaining a reasonable scepticism about group-think within the 'nuclear' community, and especially the commercial forces at all levels.
Despite some dramatic accidents, the worst being Chernobyl and the most recent Fukushima, I do not regard these as 'final nails in the coffin' of nuclear power. There is great controversy about the actual number of deaths, but on the whole I find the lower estimates more convincing. Even some of the higher ones however, do not mean that nuclear power is unusually dangerous. To compare the health effects of energy technologies, we should measure mortality or morbidity per unit of energy generated. When this is done, even including the famous accidents, nuclear power emerges as one of the safest forms of energy generation.
To illustrate what I mean, imagine two different energy technologies, each generating the same quantity of energy over say 50 years. One might cause, say, 10 deaths a year, so 500 over the whole period The other might cause zero deaths in routine operation, but might kill 500 in a single accident. The risk levels are the same over the long term, but the patterns are different, and the rare accident is almost certain to stand out more than the routine risks. This might well induce a special sense of dread, and I suppose we have to acknowledge that. But statistically I am not convinced that nuclear power has proved especially dangerous, so far at least.
Nuclear power has substantial limitations, of which more later. But we ought to acknowledge its pre-eminence with respect to the natural world and biodiversity. Of all energy technologies, nuclear power has the least impact on Nature per unit of energy generated. The reasons for this are twofold. One is that the energy density is extremely high, so its literal 'footprint' (including mining) is small, and the quantity of raw materials (concrete, steel etc) is low relative to energy generated. Anybody can do the sums to check this, or refer to standard texts such as Vaclav Smil’s Energy Density (MIT Press, 2017).
The other reason for the low impact of nuclear energy on the biosphere is that the energy-generating processes are not chemical, and so do not interact strongly with the natural world, for which chemistry is all. Nuclear power exists in a kind of parallel universe that coexists rather neutrally with natural ecosystems.
It will doubtless be argued that because events such as the Chernobyl explosion generated high levels of radioactivity that lasted many years in the area around the reactor, there must have been substantial effects on the local flora and fauna. Indeed there were, but this would not affect the wider populations or the functioning of food webs. In the natural world, individuals don't count: they nearly all die anyway, but we have a strong tendency to project our own human concern for individuals, as some do with, say, bird-strikes on wind turbine blades, equally fallacious. Any rise in the mutation rate would be lost in the normal processes of natural selection.
The upshot of this argument is that for the kinds of environmentalists whose highest value is the natural world, nuclear power should be favoured over pretty well anything else. I think it is probably true for many professional ecologists (and for 'Gaians' such as James Lovelock), but apparently not for some groups (such as Earth First!) ostensibly campaigning on behalf of the Biosphere. Intellectual consistency is probably not to be expected from this direction.
The case for nuclear power is probably enhanced too, by the widespead acceptance of Johan Rockstrom's concept of 'Planetary Boundaries'. An increasing proportion of nuclear power would not only help mitigate trends in climate change and ocean acidification, but in biodiversity and land use too, although there would be a question mark over the freshwater boundary, since all nuclear plants are very thirsty. This aspect deserves greater independent scrutiny.
How far could we go with a nuclear economy? Can we imagine for example, a kind of 'Super-France' that uses only nuclear power as the primary energy source? As far as I know nobody has modelled this, but we can assume an economy where as many as possible of the energy services are 'electric', including heating and transport, although a nuclear power station also produces a lot of heat, that could be used for district heating and industrial processes. When direct demand for electricity is low, nuclear electricity could be used to generate hydrogen for use in transport, backup and demand-matching and for all manner of other uses. It could theoretically work, and if 100% could work, then any other proportion will work too.
However, in the world as we find it, it seems to me that the strongest case against expanding nuclear power concerns risks in an unstable world. I am convinced that humanity is entering a very turbulent period that will last for the rest of the century. If climate change mitigation fails completely, as it well might, then probably by 2050 we are faced with an indefinitely continued nightmare world of widespread state collapse and tens of millions of desperate refugees.
It could be argued with drastic geopolitical problems like these, any difficulties with nuclear power would be relatively unimportant. I disagree here. That is not a world in which to try and maintain proper functioning of nuclear power stations and nuclear fuel cycles.
So, if we were absolutely sure mitigation will fail, it would be foolish to develop nuclear power any further. But nuclear is supposed to be a key part of the overall mitigation strategy to prevent dangerous climate change, avoiding regional collapses and leading to a stable, sustainable world for all humanity. Does this justify it? Personally I think not. The world is going to be unstable anyway: look at what's happening in the middle east! The best hope is a crash transition programme somewhat like that envisaged by Paul Gilding and Jorgen Randers in their One-Degree War Plan. Physically, this works, reduces GHG concentrations and keeps the temperature below the two degrees. Physically, we know how to do it. But it will still be incredibly messy and there will still be wars, state collapses, refugees and mad cults of all descriptions.
'Mad cults' are an important consideration. Adherents of such cults do not share our concern for the long-term well-being of modern civilisation and the biosphere. They might well be 'mad' in ethics and motivation but they can be superbly rational in strategy and technical ability. Think of the planning and execution of the 9/11 attacks. That was just a dress-rehearsal. Imagine disaffected sub-cultures, powerful cults or rogue states playing a long game and determined to disrupt 'enlightenment' states in the most effective ways possible. Naturally there will be 'ordinary' explosives terrorism, but it seems to me that nuclear power plants and the fuel cycle will be attractive targets, vulnerable to cyber-attack and internal sabotage as well as direct physical assaults.
I do not entertain much doubt that such things are bound to happen. They could easily bring the whole nuclear sector to a halt, and we would be obliged to manage the energy system without it. We could, and we can, so for what it's worth, my view is that we should design an energy system that does not depend on nuclear power. It is too 'brittle' for the present situation.
Will, then, the lights go out? In a non-fossil energy system based principally on renewables, a nuclear component does not help very much. Most of the big renewable systems are variable, and need backup plants able to respond swiftly to shortfalls. Nuclear cannot do this. Provided there is adequate backup, which is admittedly expensive, but do-able, a thoroughly reliable all-renewable energy system is possible. This is convincingly demonstrated by for example CAT's 2013 Zero-Carbon Britain model and Australia's Beyond Zero scenario.
Many other decarbonisation programmes do incorporate elements of nuclear power, although most do not. See Who’s Getting Ready for Zero?