Robot used in demolition at Dounreay reactor site

The machine demolishing parts of the inside of a building at Dounreay

A robot has demolished parts of a site associated with the first operational reactor to achieve criticality in Scotland almost 60 years ago.

The Dounreay Materials Test Reactor (DMTR) achieved criticality, a nuclear term referring to the balance of neutrons in the system, in 1958.

The robot, Brokk 180, was used to dismantle parts of the interior of the reactor's support buildings.

DMTR is part of the Dounreay nuclear power complex near Thurso in Caithness.

The site is being decommissioned and its buildings demolished.

Bill Lambie, who has been managing the project at DMTR, said the completion of the robot's work meant the support building could now be demolished.

He said reaching this phase was "a significant achievement, made possible through the skills, ingenuity and hard work".

Robots are frequently used in the decommissioning work at Dounreay, as they can operate in areas of the site with dangerous levels of radiation.

They include a 75-tonne machine nicknamed Reactorsaurus.

DMRT was the first operational reactor to achieve criticality in Scotland on 24 May 1958.

However, a system known as a rig and named the Zero Energy Thermal reactor installed at Dounreay in 1956 went critical for the first time on 13 August 1957.

This was the first artificially made criticality in Scotland.