Robot removal

Engineers in charge of dismantling a redundant nuclear reactor at Dounreay have unveiled the design of a giant robot, nicknamed Reactorsaurus, that cuts apart and removes equipment from the hazardous environment.

The team behind the 75-tonne Reactor Dismantler Manipulator (RDM) hope to award a contract in July to build a test model.

Work began two years ago on the RDM, which is designed to dismantle the liquid-sodium-filled prototype fast reactor that ceased operation in 1994. Once the sodium has been completely removed, the RDM will be used to cut up all equipment, including the pipework and the shield rods, into manageable pieces and lift them out of the reactor using two pincer arms that wield interchangeable cutting and lifting tools.

Jared Fraser, who leads the RDM design team at Dounreay Site Restoration Ltd (

), described the environment the RDM will have to work in: 'A lot of the fuel, the breeders and reflectors there are highly radioactive so we can't do manned entry. It is also mostly below ground in a large tank and the only way to get into it is to remove the retaining shield, which then gives us a 3.7m diameter access port in the 60m vessel.'