Drone used for inspection work at Dounreay near Thurso

The drone is being used for inspections of Dounreay's tallest structures

A drone is being used at a Scottish nuclear site for work that can involve a risk of injury and cost thousands of pounds to be done by people.

The camera-equipped unmanned aerial vehicle is being flown on inspections of Dounreay's highest structures.

Dounreay Site Restoration Limited (DSRL) said it carries out about 50 such inspections every year.

The nuclear power site on the north Caithness coast near Thurso is in the process of being decommissioned.

Dounreay is the north coast of Caithness

The drone, which can fly to heights of up to 120m (393.8ft), has so far completed two aerial inspections.

Its use could save hundreds of thousands of pounds in costs, according to DSRL.

Tall structures on the Dounreay site include its landmark Dounreay Fast Reactor dome. The tallest structure on the site is 55m (180.5ft).

Machines have been used before for hazardous work at the plant.

They have included a device described as a "hi-tech worm" that was used to probe the condition of a pipeline once used to discharge radioactive effluent.

The £100,000 pipe crawler beamed back images from inside the underground pipeline to the sea that was in use from 1957 to 1992.