It is 60 years this weekend since the first criticality was achieved in Scotland using a test rig at Dounreay. Now the decommissioning team responsible for the site is marking that milestone by taking a major step towards demolishing the oldest reactor that remains at the former fast reactor research centre.
Companies are being invited to bid for a contract to demolish the iconic Dounreay Materials Test Reactor (DMTR) which became Scotland's first operational reactor in 1958. DMTR, which was built with steelwork weighing in at almost 600 tonnes and stands on foundations more than 25 metres in diameter, tested the effects of irradiation on metals and was the only reactor on the site to use heavy water instead of liquid metal as a coolant.
Fuel was removed soon after it shut down in 1969 and many of the surrounding facilities, including cooling towers, emergency control room and pipework have since been cleared out and demolished. The control room desk and panels, which were key to the operation of the reactor, were transferred to Caithness Horizons in 2015 where they remain on display and the final support building is on track to be knocked down by the end of the year.
Bill Lambie, Project Manager, said: "This month we celebrate the 60th anniversary of the first criticality in Scotland, which took place in a temporary test rig. That was an immense achievement, and we are now poised to demolish its successor and the oldest reactor on site, DMTR.
"The removal of DMTR from the skyline will be a significant step for Dounreay, and will be a real and visible sign of the decommissioning progress being made."
A contract notice will appear in the Official Journal of the European Union for the project estimated to be worth around £7 million over three years. A contractor is expected to be appointed in the first half of 2018.
The first criticality, where neutrons collide to create a nuclear chain reaction, was achieved in a test rig known as ZETR (zero energy test reactor) located alongside DMTR at lunchtime on 13 August 1957. Bill added: “This was an historic moment because it put Dounreay on the map as the UK's centre of fast reactor research, and encouraged the local population to acquire scientific skills and abilities that have been associated with the area ever since."
