Michael Meacher - Labour's Future

With French and German companies lining up to build new nuclear power stations in Britain, the die now seems cast for nuclear. Or is it?

The Government’s goal is certainly ambitious. Ten countries – primarily the UK, USA, France and Canada, but also including Japan, Korea, Brazil, Argentina, South Africa and Switzerland – have set up a body called the Generation IV International Forum to develop a successor nuclear energy system to the previous Generations I (Magnox) and II (AGRs and the Sizewell B Light Water Reactor) and to follow the Generation III systems now being built. The latter includes the French Areva Evolutionary Pressure Reactor (EPR), the prototype of which is currently being constructed at Olkiluoto in Finland, with another being built in France. It is intended that these Generation III models plus (hopefully) improved versions in future will lead reactor orders through to 2030, after which it is hoped that Generation IV will kick in, the goal of which is nuclear sustainability.

However, the roadmap to get there is beset by profound practical problems which may well prove insurmountable. Generation II and III nuclear power plants operate in a ‘once-through’ mode, which means that only half of the 0.7% fissionable uranium U-235 content of natural uranium goes into the fuel while most of the heavy metal ends up in enrichment tails and in spent fuel as waste. This therefore requires a constant and increasing supply of natural uranium to meet the rising demand for electricity, while at the same time it intensifies the already unresolved problem of what to do with vast accumulations of radioactive waste.

Even the optimistic IAEA-OECD Red Book of world uranium reserves puts the total at 4.7 million tonnes, and that assumes a purchase price of at least $130/kg. In fact prices are currently nearly twice as high, yet primary uranium production is falling. But even if the Red Book figures were roughly correct and not significantly inflated, their total of known uranium resources is expected to be exhausted by 2030.

If fast reactors were to be introduced by then – which is the centrepiece of the strategy – a further 10 million tonnes, twice the known resources, would have to be ready for production, and this could only come from ‘speculative and undiscovered resources’. The nuclear power industry answers this by reference to the universality of uranium in the Earth’s crust and in seawater; but the enormous energy needed to extract it from these low concentration sources would actually exceed the energy output of the fission of the fuel thus provided, so in terms of net energy availability it is irrelevant.

These pressures are already being felt. The US gets half its nuclear fuel from diluted former nuclear weapons’ highly enriched uranium from Russia, and even Russia itself with its insufficient primary production will be forced to rely on ex-weapons material to power its planned expansion. The UK’s aim of security of energy supply will not be aided by 100% import of nuclear fuels on top of increased dependence on imported fossil fuels, notably gas. Japan has closed 7 nuclear power stations built on an earthquake fault line. Olkiluoto is already 2 years behind schedule after just 2 ½ years building and already has a £1bn cost overrun, and there can be no reliable evidence on the economics of nuclear power until the new designs of the Westinghouse AP1000 and European EPR water reactors have been fully tested over many years in service. Contrary to claims by the industry, unresolved questions of cost and the looming shortage of uranium are the biggest challenge to its revival.

To overcome the fragility of this recovery, the industry looks to Generation IV development of the fast reactor by 2030 as the key to ultimate nuclear sustainability. However if for this purpose the fast reactor were adopted in ‘breeder’ mode, an even greater quantity of highly radioactive actinides (plutonium, neptunium, americium and curium) would be generated, exacerbating still further the waste management problem. If on the other hand the fast reactor were adopted in ‘burner’ mode, as currently seems likely to prevail, the waste problem is alleviated, but there is no sustainability.

The Generation IV fuel systems offer at present 6 types, of which two are emerging as likely candidates. One is the very-high-temperature gas-cooled thermal reactor (VHTR) which can be used for coal gasification as well as thermo-chemical hydrogen production. The US Government favours this because a hydrogen economy is seen as the solution to the exhaustion of oil reserves and the petrol (gasoline) derived from it. The main problem with the VHTR, which has a coolant system outlet temperature of about 1,000ºC, is likely to arise from irradiation characterised by the Wigner Effect and from progressive disintegration by neutron bombardment.

Indeed a similar problem with the Wigner energy in pile 1 at Windscale (now Sellafield) caused the fire and melted the fuel elements. Given the very high temperatures needed for this complex and quite likely unstable process, its viability would need rigorous and exhaustive testing before such a problematic reactor were ever adopted.

The second favoured Generation IV candidate is the sodium-cooled fast reactor system (SFR). The idea here is that as supplies of natural uranium decline, it is replaced by a plutonium-based fuel which is incrementally augmented by fresh plutonium in a repetitive cycle, providing claims of sustainability. It is envisaged that there is a gain in the plutonium in a surrounding ‘blanket’ of uranium 238 over and above the plutoniun consumed in the reaction, with a doubling time of 15-20 years. But again there are two key problems. It is a burner reactor, not a breeder, so that whilst reducing waste management problems it does not provide for sustainability.

Secondly, even if fast reactors of this kind could be successfully deployed – a big if – the doubling time of 15-20 years would require supplies of natural uranium to be maintained for decades, if not centuries, until the fleet of ‘once-through’ reactors can be progressively replaced. And the uranium simply isn’t available for that timespan. So, a nuclear renaissance? Forget it.