Nuclear power? What about Fusion?

The difference between nuclear power stations and nuclear bombs

Virtually all nuclear power stations operating in the world are based on nuclear fission of U235. The trouble is that in the pure uranium, U235 is only a tiny part of the whole, representing 0.7% of the uranium. The remaining 99.3% is U238. For a power station you need to raise the concentration of U235 to around 4% and for a uranium bomb usually to around 90%. Separating the 2 uranium isotopes turns out to be extremely difficult and costly. One method is by centrifuges, spinning the uranium so that the heavier form very slowly moves to the outside.

However a much easier way of making atom bombs is to create plutonium. You do this by cladding the nuclear power station core with U238. As the neutrons hit it, the U238 changes in 2 stages to Pu238, which is plutonium. The early nuclear power stations were specifically for making plutonium and the energy was simply a by-product. It even says this on the Pathe News programme recording of the Queen opening our first nuclear power station at Calder Hall in 1956.

But there was also the dream of building plutonium power stations, called Fast Breeder Reactors, for which the fuel would be created in a fission reactor. Unfortunately the attempts to do this ran into all sorts of problems, and Britain, the USA, Germany, and France have all given up after spending vast sums of money on it. Russia and Asian nuclear powers have not abandoned it yet. If fission had worked, then there would have been abundant fuel. But as it hasn't then suitable uranium supplies are limited. Estimates for the supply of uranium at present world consumption differ widely but range around 80 years.

The costs

The main cost in nuclear power is the capital cost of the building. A huge amount of money has to be borrowed while this is under construction with no return until the building is completed. If there is a delay the costs rise dramatically and this has often happened. It is happening now quite disastrously in Finland to the first nuclear power station to be built in Europe for more than a decade. Once built, a nuclear power station has to be kept running as much as possible to meet the debt repayment so it has to be part of the continuous base load. France seems to have managed a high share of nuclear power by selling its surplus to other countries. When a nuclear station is out of action for servicing, a big chunk of power is lost, so this has to be planned. If it is closed down for some other reason, there can be serious problems in electricity supply.

The industry maintains that it is cheap, but there are some enormous hidden costs:

• Decommissioning costs have not been included. These are now estimated to be around £72 billion for the UK, and future taxpayers will pay for this.
• Accident costs to the general public are not covered. In every single one of our home insurance policies, costs resulting from a nuclear accident are excluded.
• Nuclear waste management costs are also not included. High level waste has to be constantly cooled. One such waste is plutonium, of which Britain has more than enough for 1000 bombs. The half life of plutonium (the time it takes to halve its radioactivity) is 24,000 years!
• Then there are the costs of nuclear weapons proliferation, if nuclear power is seen as a worldwide solution for global warming. You can see from the explanation above that the easiest way of making an atom bomb is from a civil nuclear power programme and that is how a number of nuclear weapons nations have acquired their nuclear weapons.
• The Irish Sea is the most radioactive sea in the world as the result of discharges from Sellafield. It cannot be cleaned up. This has been complained about by countries as far away as Norway.
• The mining of uranium is an extremely dirty process and requires a lot of energy. This considerably raises its carbon footprint.
• By far the largest part of Britain's research and development in energy from the 1950s for 50 years went into nuclear power. That is one reason why we are so far behind the majority of European countries in developing alternatives, despite having the best renewable energy resources of any country in the European Union.

Nuclear accidents

We know something about the major accidents such as Chernobyl, Windscale, Harrisburg and Thorp, Sellafield, but a great deal is covered up or simply not widely reported. For instance, what Swedish scientists reported as the next worst accident after Chernobyl and Harrisburg rated a single paragraph buried in some British newspapers. On July 25th 2006 a short circuit caused a main power failure in Forsmark 1 nuclear reactor. There were 4 independent backup power supplies. 2 failed. Fortunately the other 2 worked. Had they also failed, which statistically from the evidence was a 1 in 16 chance, Swedish Nuclear engineers stated publicly that the resulting disaster would have been worse than Chernobyl.

Sweden is a country with some of the highest safety standards. Nuclear power stations are being sold to countries with much poorer standards. If there is a widespread expansion of nuclear power, another Chernobyl will happen through human error. When it happens, nuclear power stations under construction will be halted by popular demand and energy policies of countries depending on them will be in tatters.

Nuclear Fusion

Nuclear fusion is a completely different matter. It entails adding (or fusing) protons to hydrogen isotopes. It requires a huge amount of focussed heat to produce a yet more massive amount of heat. It creates very little radioactive waste. This is the form of nuclear power that James Lovelock has mainly advocated.

The trouble is that it has always been seen as realisable in 40 years time, and that prediction keeps on being 40 or 50 years into the future. The heat required is so great that no material can support the reaction and it has to be held in a magnetic field. The problems of creating, holding and harnessing the energy are immense.

However we already have an enormous, safely located, and reliable fusion reactor in the sun, and also the means of harnessing its energy. Plant photosynthesis, solar panels and solar cells and are direct ways of harnessing it. The temperature difference between the equator and the poles drives the wind. Wave energy is an accumulation of wind energy over a wide stretch of water. Evaporation of water which then falls as rain on high ground gives us hydro power. So wind, wave and hydro power are indirect ways of harnessing the sun's fusion energy. (Tide is caused by the gravitation pull of the moon, and to some extent the sun, and is like water constantly falling downhill towards the moon.)

Most of our present forms of renewable energy are means of harnessing safe, reliable, abundant and existing nuclear fusion. What we should be doing is recognising and utilising this benevolence.