Les Hearn contributes to our debate about nuclear power
Earth’s climate has changed many times throughout its four billion year history and it seems beyond doubt that it is changing once again. But this is the first time that a single species has been responsible for the change.
Through our technological expertise, we have discovered and exploited vast resources of hydrocarbons (coal, oil and gas), fossil remains of plants and animals that died half a billion years ago. Some we have turned into novel substances, such as plastics and artificial fibres. These characterise our modern societies to a great extent. But most we have simply burnt to heat our homes, drive our vehicles and power our factories. And it doesn’t take a PhD to work out that once these fossil fuels are gone, that’s it!
Worse, the carbon dioxide released by burning these fuels will alter (is altering!) the climate, by an effect that was identified by the great Swedish chemist Arrhenius over a hundred years ago — the absorption of heat by CO2 in the atmosphere. Arrhenius even estimated the effect of increasing CO2 levels on global temperatures. He calculated that doubling the level would increase the average temperature by about 5º C, only slightly higher than the top estimate of the Intergovernmental Panel on Climate Change (which has the benefit of a century’s worth of meteorological research). At the then current levels of increase, Arrhenius estimated that it would take 3,000 years for CO2 levels to double. Now it seems likely to occur within about 30 years.
It would therefore be prudent to find alternatives to fossil fuels sooner, rather than later. In any case, they are going to run out but, before they do, their combustion will have increased atmospheric CO2 levels still more.
In addition, disputes between countries supplying and consuming fossil fuels will cause instability and massive price rises. The recent conflict between Russia and Ukraine over the former’s tripling of gas prices nearly led to the latter’s being without power and did lead to disruption of supplies to neighbouring countries, while a recent cold spell in Russia has led to fears of cuts in gas supplies to western Europe. By 2020, about a fifth of Britain’s energy needs will be met by importing Russian methane.
Now, there are huge quantities of spare energy around: the problem is how to use it. Most of it comes from the Sun, either directly, as light and heat, or indirectly, as wind and wave energy or energy in flowing water or in wood and sugar (biomass).
Tidal energy comes from the orbiting of the Moon, while geothermal energy comes from the decay of radioactive elements in the Earth’s core.
Nuclear power at present functions using artificially-induced fission of one of these elements (uranium) and of an element produced in reactors (plutonium).
Supplies of most of these are essentially infinite: the Sun will last for some five billion years before swelling up into a red giant star and vapourising the Earth; the Earth-Moon orbital system should last billions of years also before the Moon recedes to such a distance that tides become insignificant.
It is worth considering uranium reserves in more detail. These are, of course, finite but one of the by-products of nuclear power is plutonium. Fast breeder reactors could greatly increase the amount of the latter. In any case, the limiting factor of price, which determines whether it is worth searching for and exploiting uranium reserves, is of little relevance to the overall commercial viability of nuclear power. This is because the major expense is in plant… and decommissioning. Therefore, a substantial hike in uranium prices could expand useful reserves without making nuclear power much more expensive.
An additional source of fissile material is from the nuclear weapons stockpiles. Even without nuclear disarmament, it is estimated that the US is getting nearly 10 years’ worth of nuclear fuel from decommissioned weapons. One estimate is that, bearing in mind these facts, reserves will last for hundreds, or perhaps thousands, of years.
Logically, it is better to use renewable resources, as long as they do not have unacceptable social or environmental costs. But most of these have the problem that their energy is present in a very dilute form, such as low grade heat or slow-growing tree plantations. Many are also not constantly available — tides are only twice daily, it is dark at night or in winter, the winds don’t always blow. There are ways of mixing and matching resources (for instance, putting wind turbines where the Sun don’t shine!), but it is difficult to see how purely renewable sources could provide us with the constant supplies we have come to depend on.
The journalist George Monbiot, who champions environmentalism and opposes globalisation, gave this matter detailed scrutiny in his Guardian column a few weeks ago. Making the most favourable assumptions possible about reduction in demand through conservation measures, assuming that the problem of energy storage (to even out supplies and to cater for peak demand) had been solved, assuming substantial windfarms, tidal barrages, wave power machines, and so on, Monbiot comes up with a shortfall of over half the energy needed. He reluctantly concluded that some mix of fossil fuels and nuclear power seemed the only solution. The continued use of fossil fuels is justifiable only if the CO2 can be captured and stored underground, an unproved and expensive idea. Perhaps it is time to think the thinkable, and reconsider nuclear power.
It is true that nuclear power has some disasters to its discredit and is about as popular as anthrax. It is also true but less recognised that fossil fuel energy carries with it a staggering human cost, in deaths and diseases of miners and in the pollution of the air breathed by the majority of people. There is also the problem of disposal of highly radioactive waste, not so far solved. The “problem” of terrorism is a largely spurious one: a suicide “dirty” bomber would be just that, dying before having a chance to do much damage; power stations can be made and probably already are passenger plane-proof (and no-one’s proposed demolishing skyscrapers to prevent their attack post-9/11, as pointed out in Solidarity recently).
But the past does not determine the future! Modern fission reactors are being designed to safer “fail-safe” specifications. Research into the transmutation of nuclear waste in special reactors promises reductions in waste of 95% or more, with generation of energy as well!. Proposed new types of reactors could use the widely available element thorium to generate energy in a more controllable way, with no chance of run-away reactions like Chernobyl. And, if we’re serious about nuclear disarmament, what better way of getting rid of redundant bombs?