Why is nuclear power back on the political agenda?

Britain is heading for an energy gap caused by rising demand and falling supply and some see nuclear power as the only way of filling that gap. Nuclear power stations supply about a quarter of the country's electricity but that figure will fall in the coming decade as older stations are decommissioned.

Experts suggest that within 10 years there could be an energy shortfall of 20 per cent if nothing is done. It could take 10 years to build new nuclear power stations so the Government has to decide soon whether to go ahead and build them again.

Why can't we fill the gap with renewable sources of energy?

Much work is being done on increasing the efficiency of power generation using wind, wave, tide and solar energy. Although there may be some environmental objections, to wind farms for instance, these renewable power sources have the advantage of being sustainable and clean.

However, not everyone is convinced that they can fill the energy gap on their own. Even the most optimistic assessments suggest that renewables might only be able to fill half of the energy gap, and many other assessments are more pessimistic.

Can we not just use coal, oil or gas?

Britain's reserves of natural gas and oil have probably passed their peak and will start to run out over the coming decades. To fill the gap we are having to buy gas and oil from other countries, but unfortunately these are not the most friendly or stable places in the world.

Russia could supply much of our needs but future governments might worry strategically about security of supply. The events this winter, when Russia shut down supplies to the Ukraine, showed how vulnerable energy customers can be to political pressure. An equally important reason for not buying fossil fuel from abroad is the Government's commitment to reduce emissions of carbon dioxide because of global warming. This is one of the arguments in support of rebuilding nuclear power stations, which do not produce carbon dioxide.

So what have we got against nuclear power?

Nuclear power stations may be good for climate change, but they still produce toxic waste which can remain radioactive and dangerous for thousands of years. Britain has yet to decide on what to do with the radioactive waste that has built up from nearly 50 years of nuclear power. Another important issue concerns safety and nuclear proliferation.

Chernobyl showed that a nuclear accident can be devastating - and does not respect national borders. If Britain goes ahead with new nuclear power stations, why shouldn't other countries in Africa, Asia and South America do the same? A world with thousands of nuclear power stations may not be as safe as a world with a few dozen.