How governments have failed to tackle an £85bn problem

Why has the issue of nuclear waste come up again?

The Government is contemplating building a new generation of atomic power stations, and the highly radioactive and dangerous waste - mainly spent nuclear fuel from reactors - is an inescapable by-product of their operation.

But haven't we had nuclear power for 50 years? Why is this still a problem?

All British governments since the 1950s have dodged the issue of how to make a final disposal of our nuclear waste. It's a technical and public relations problem. Nuclear waste is dangerous for thousands of years. The half-life of plutonium, the time a given amount of one of the most dangerous substances produced in atomic power stations reduces in radioactivity by half, is 24,000 years.

Why is the Government thinking of building new nuclear power stations?

It is reviewing its options for supplying the country with energy over the next 20 to 30 years. The Energy Review to look at this was launched yesterday and will present results "by the end of the summer".

We know the greens never liked nuclear power, but hadn't it long ago fallen out of favour with the Government too?

New nuclear power stations seemed unlikely ever again in Britain after the privatisation of electricity in 1989, not least because of the enormous costs of decommissioning the stations at the end of their lives. But suddenly nuclear is back in favour with some people in Whitehall and Westminster and it seems that ways may be found around the prohibitive costs. Officially, the Government hasn't yet made up its mind, but many people believe it has and the Energy Review is just a formality.

So why is nuclear back on the Government's agenda?

The Government says for two reasons: security of energy supply, and climate change. Take security of supply first. Britain has 12 nuclear power stations providing just under 20 per cent of our electricity. But they are ageing and by 2020 it is likely that all but one - Sizewell B, in Suffolk - will be decommissioned and the nuclear supply will be down to less than 7 per cent. This loss in generating capacity will be matched by a similar loss in capacity from coal-fired power stations because of new EU laws on gas emissions. So Britain faces losing about 30 per cent of its generating capacity in the coming decades and will have to make this up from other energy sources. The likeliest candidate is gas. But that means we will have to import up to 80 per cent of the total needed, probably from Russia. Recent events in Ukraine have shown that Russia is not above turning the gas tap off when the mood takes it. Some analysts think this is too great a strategic risk for the UK to take.

What about climate change?

The advantage of nuclear-generated electricity is that it does not produce the large amounts of carbon dioxide that are an inescapable product of energy generation using the fossil fuels. Britain wants to cut its CO2 emissions by 60 per cent by 2050 and some influential figures in the Government feel that a new generation of non-CO2-producing nuclear power stations is essential in achieving that.

But can't that be done with renewable energy - wind, solar and wave power?

Environmentalists say it can, and see nuclear power as a dangerous distraction. While the Government is committed to renewables, it does not believe that new power generation from renewables would equal the loss of the nuclear generation by 2020. Sir David King, the Government's chief scientific adviser, calls this "the energy gap". He sees another generation of nuclear power stations as necessary.