Nuclear plant bosses today revealed plans for a £25 million clean-up operation to remove thousands of radioactive particles released into the sea.

The preferred option for dealing with the legacy of the nuclear fragments which leaked from the Dounreay site in Caithness has been announced.

The seven-year project involves using remotely operated vehicles to scour an area of seabed the size of 60 football pitches.

It would be combined with an onshore operation to monitor and detect particles.

The announcement follows a two-year public consultation on how best to dispose of the irradiated nuclear fuel fragments.

An estimated 10,000 particles were discharged from Dounreay to the surrounding environment in the 1960s and 1970s.

Site operators the UK Atomic Energy Authority (UKAEA) believe the discharges were released into the sea through the plant's low active effluent drainage system.

Some of the fragments of irradiated nuclear fuel have been detected on Dounreay's surrounding beaches as well as on the seabed.

Earlier this year UKAEA was fined £140,000 by a court after admitting releasing radioactive particles into the sea and illegally dumping radioactive waste.

The cost of the proposed onshore and offshore monitoring and recovery has been estimated at £18-£25 million.