Engineering and construction group Costain said it has won a £297m contract to provide its services at one of the largest nuclear projects in the UK. The group has been hired by Sellafield for engineering, procurement and construction of the Evaporator D project, Costain said in a company statement. The contract is an extension of an original Purchase Order awarded in September 2006 for Front End Engineering Design. The project is scheduled for completion in 2014.