As policymakers, engineers and others grapple (often unsuccessfully, it seems) with the problems of how to provide a secure, affordable supply of grid electricity in developed countries, it is easy to forget that electricity on tap is a rather recent innovation. The first commercial (and localised) grid was only set by Edison in 1882, to supply part of Manhattan. Nine years later, the first UK electricity station was opened, in Deptford. Most of the developed world was only connected to a power grid about a century ago.
In that period, there have been numerous inventions and improvements, but electricity is still generated either using water power, where geography permits hydro schemes to be built or, more commonly, thermally, as it was at the end of the 19th Century. Then, coal was the only real source of heat to produce steam and drive the turbines, but now natural gas vies with it for dominance. And we should not forget that, in the lifetimes of many readers, natural gas has replaced water gas, itself produced from coal.
Otherwise, the only innovation in the means of raising steam for turbines was the use of nuclear fission from the 1950s onwards. From a promising beginning and a period of rapid growth, enthusiasm has waned and little new capacity has been added for some time. Nevertheless, nuclear power plants still supply 13% or more of the world’s electricity, and a much higher proportion than that in some countries (19% in the USA, over 70% in France and, until recently, averaging 30% across the EU).
With the current drive to reduce carbon dioxide emissions, new nuclear plants have once more come higher up the agenda in many countries. Despite the claims of renewable energy enthusiasts, there is no way that wind, wave, tidal or solar arrays can provide a reliable, flexible, secure supply of electricity to the grid, at least without very large scale energy storage options which are unlikely to be available for many years yet. Even the projected Europe-wide DC super grid would be at best a partial answer. Nuclear, on the other hand, has the major advantage of combining essentially zero-carbon electricity with reliability and security of supply.
But plans to build new reactors in the UK are in the balance, and the problem is largely one of image. Nuclear power generation is very safe, but that is not necessarily how the public sees it. Perhaps this isn’t surprising for a technology whose destructive power in the form of the atomic bomb was harnessed before its peaceful uses were made available. Atomic radiation, despite the good its controlled use has brought to healthcare, does not have a good press.
Deep in the psyche of many of us, a dark cloud hangs over nuclear power, usually mushroom-shaped. The fear is of a disaster occurring, or merely a leak of radiation. More scary even than an explosion is often the worry of the invisible, long term effects of radiation: cancer and birth deformities. Partly, this is a rational response to the ultra-low exposure limits deemed to be safe. But these limits were imposed on the understanding that there really was no ‘safe’ limit for exposure; that the dose/response curve tended to the origin of the graph, with no threshold limit.
In fact, there is plenty of evidence that the body can cope perfectly well with low levels of radiation, with occasional DNA mutations being repaired along with the other random point mutations which occur in daily life. There is no evidence that living in Aberdeen, with its relatively high level of background radiation from the granite widely used for building, has any harmful effect on health. The concept of hormesis – that low levels of radiation may actually have a beneficial effect on health – is also a perfectly credible and respectable hypothesis, although it is not universally adhered to.
The Chernobyl disaster of 1986 was by far the worst nuclear accident ever to have occurred, and one that would be impossible in reactor designs now in operation. But, although dire predictions were made for the number of deaths and amount of long-term health damage which would occur, there were in total 28 deaths due to acute radiation exposure of emergency workers, plus 15 fatalities from thyroid cancer in following years (thyroid cancer is a particular risk because of the concentration of radioactive iodine, but responds well to treatment, with very high survival rates). Official estimates from international bodies are of a smaller than one percent increase in the lifetime cancer mortality risk for the 5 million inhabitants of the surrounding area. Nevertheless, Greenpeace and other organisations still talk of hundreds of thousands of deaths.
The more recent Fukushima disaster was nothing to do with nuclear technology per se, but was simply a matter of a poor choice of location and basic design: if backup diesel generators had been placed higher, they would not have been flooded and the plant would have shut down safely. There were no direct fatalities from acute radiation exposure, and a relatively small number of people received comparatively high doses. The tsunami itself was far more destructive, and the major radiation-induced damage is likely to be psychological.
There remains the issue of nuclear waste. In fact, most of the waste material is mildly radioactive items which have been exposed to radiation, with about 95% of the total radioactivity remaining in a very small volume which is highly radioactive and needs screening for many thousands of years (and cooling for a considerable period, as well). Not only are some of the components highly radioactive, but they also have very long half-lives. But this is an existing problem which we will have to deal with, and new reactors add relatively little to the total. In time, it is likely that most countries will find suitable long-term deep underground storage options; there seems to be public support for identifying a suitable site in Cumbria, for example.
But spent fuel can also be reprocessed and used a source of raw material rather than abandoned as waste. And the current reactor technology is not the only one. Fast breeder reactors, already successfully demonstrated on a large scale, can make much more efficient use of uranium. In the longer run, thorium is favoured by some as an alternative to uranium. The point is that what seems to be a problem is likely to be solved in coming decades. In the meantime, societies need energy security. Now is not the time to abandon the one reliable, safe, low-carbon approach to electricity generation we have available.
The Scientific Alliance
St John’s Innovation Centre
Cowley Road
Cambridge CB4 0WS
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