Nuclear waste and its disposal is back high on the political agenda. Shahid Naqvi examines the background to the thorny subject

How to deal with hazardous nuclear waste produced by Britain's 16 nuclear power stations has long been a contentious issue.

Finding a solution has become even more urgent after the Government this year committed itself to a new wave of nuclear power stations to replace ageing plants.

This summer also saw the completion of a three-year study by the Committee on Radioactive Waste Management (CoWRM) into nuclear waste disposal.

It concluded the best way forward for getting rid of waste from existing plants was to bury it underground, similar to other European countries.

Currently, medium level nuclear waste is stored above ground at nuclear power plants.

Highly toxic waste is transported to Sellafield to be processed.

Debate has been raging for decades as to how best to dispose of the material. The possibility of storing it under-ground was looked at in the 1980s when nuclear waste disposal firm Nirex produced a list of 537 locations.

"The sites that were on the 'long list' were there primarily because they were suitable geologically and because of who owned the land," said John Dalton, spokesman of Nirex, which last year was brought under Government control.

"There was a sieving exercise which brought the list down to 204, ruling out those that had obvious deficiencies.

"After that, land ownership was looked at - for example if the land was owned by the MoD that obviously made it relatively easy. That brought it down to 165. Then they looked at the size of the site, which needed to be at least 400 hectares.

"From that there were 117 which became 39 and then down to 17 after looking at different geological environments."

A final shortlist of ten sites was drawn up. According to Nirex, Hams Hall was ruled out at the 165 to 117 stage.

The ten were in Essex, Caithness, the Western Isles, Humberside, Sellafield and Norfolk.

Public opposition and lack of political will, however, led to the project being shelved.

Tony Blair's support for a new generation of power plants as the solution to Britain's future energy needs has rekindled interest in under-ground disposal of radioactive waste.

Twenty years on, however, some of the original sites may no longer be suitable. They may have already been built upon or changed ownership.

When the CoRWM report was released, chairman Gordon MacKerron said: "For 50 years, the UK has been creating radioactive waste, without any clear idea of what to do with it.

"Whether we like it or not, waste exists and we have to deal with it. The committee has confidence that geological disposal is the best end point for managing our waste. It is the option that should perform best in terms of security, and protecting the public and the environment."

About a third of Britain is considered geologically suitable for underground nuclear waste disposal by scientists.

It would be located several hundred metres underground and encased in tough materials with the surrounding rock used as a barrier to prevent radioactive leakage into the environment.

Such facilities will to take several decades to develop and due to expense it is thought likely there may be only one or two in the country.

The Midlands is thought a likely location because of its central location.

But before any decision is made, the Government has promised a full and open public consultation.

Crucially, this will take into account local feeling. Perhaps unbelievable to some, Ministers are looking at introducing a volunteering system where local people ask to have a nuclear disposal site.

In return, they would get help with local amenities such as cash for schools, better roads, or other infrastructure.

Mr Dalton said: "That is exactly what has happened in Finland and Sweden. We may well be going down that road in this country.

"This radioactive waste has been around for 40 to 60 years and we should be doing something better with it."