Dounreay, the UK centre of fast reactor research and development from 1955 until 1994, is now Europe’s biggest nuclear site clean-up and closure project, offering engineering and environmental challenges. About 180 facilities, many containing chemical and radiological hazards, are being progressively dismantled and demolished, and their contents made safe for future generations. Cavendish Nuclear is the lead partner in a UK/US consortium contracted by the Nuclear Decommissioning Authority to manage the clean-up and deliver the site’s closure.