After being inspected for external contamination, the steel cylinder is stored, usually in an underground repository.

In a glossy brochure entitled 'The Way Forward', they set out three different versions of underground repositories.

Several countries have considered using underground repositories.

Some experts suggest that centralized underground repositories which are well-managed, guarded, and monitored, would be a vast improvement.

As of 2009 there were no commercial scale purpose built underground repositories in operation.

The "rooms" are actually tunnels carved in the material making up the underground repository.

The environmental agency sets the standards for the underground repositories, agency officials said.

Experts agree that centralized underground repositories which are well-managed, guarded, and monitored, would be a vast improvement.

There is an international consensus on the advisability of storing nuclear waste in deep underground repositories, but no country in the world has yet opened such a site.

"But before you can say it is environmentally neutral, you need to know the safety case behind the deep underground repository."