A £100m clean-up operation to remove low-level radioactive waste at Dounreay has been given the go-ahead.

Planning permission has been granted for six concrete vaults which will store up to 240,000 tonnes of low-level radioactive waste from the decommissioned site near Caithness.

Work will begin next month to create the first two vaults to take the waste which is currently being stored onsite.

It is hoped that the first concrete-lined shallow vault, set into the rock, will be ready by 2014.

A Dounreay Site Restoration Limited spokesman said: "We have planning permission for up to six vaults but we are optimistic we will not need that many.

"That is Dounreay getting buried in the ground."

The construction project is linked in to the creation of a £4m fund to help the area's economy cope with the closure of the nuclear site.

The money, from the Nuclear Decommissioning Authority, will go towards projects to help ensure the social and economic stability of the region after Dounreay has been demolished.