Battery-powered trains will be used at Sellafield in a bid to reduce emissions at the sprawling West Cumbrian nuclear site.

Sellafield Ltd has agreed a contract with Staffordshire firm Clayton Equipment to supply the two hybrid locomotives, which can switch between a small low-emission diesel engine and onboard battery charging.

Sellafield Ltd said it was planning to use them on battery power as much as possible on its large internal railway system, which is connected to the Cumbrian coast line via a rail spur, to deliver carbon emissions reductions.

They will be used to shunt wagons around the site and a spokesman said: "Part of the reason for switching is to reduce exhaust gases from entering buildings when the locomotives are operating in hoist well areas."

John Thomas, lead system engineer (transportation) for Sellafield Ltd, said: “As part of our drive to become a more sustainable business, we are committed to reducing our carbon footprint.

“Our work in this area is balanced with the need to deliver value for money and maintain progress in our decommissioning programme.

“Once in operation, these locomotives will help to contribute to our carbon reduction commitments while also ensuring we deliver our core objective of making Sellafield safer, sooner.”

Clayton Equipment said: "The supply of the two locomotives will enable Sellafield Ltd to realise significant commercial benefits from reduced operation and maintenance costs.

"Additional benefits from their investment in greener technology include reduced emissions from the cleanest diesel engines, a reduced carbon footprint, reduced noise levels, greater haulage capacity and increased reliability."