A 50 tonne “transfer tunnel” has been installed at Sellafield to aid the massive decommissioning process taking place at the site.

The transfer tunnel has been hoisted into place at the Magnox Swarf Storage Silo and is a key piece of equipment in decommissioning the highly radioactive contents of the building.

The silo was built in the 1960s and contains waste created in Sellafield’s early days, the Nuclear Decommissioning Authority has listed it as one of the four highest priority decommissioning jobs in the UK.

The silo is beyond its operational life and the contents will eventually be stored in more modern facilities and eventually consigned to the UK’s underground repository.

Manufactured by Ansaldo NES at its base in the West Midlands, the tunnel is an essential part of the Silo Emptying Plant that will decommission the contents of Magnox Swarf.

Chris Halliwell, head of the Magnox Swarf Storage Silo programme for Sellafield Ltd, said: “This is a big moment for us all. It is fantastic to see the installation of the first part of the first machine that is going to get the waste out so that we can make this building far safer.

“We need to get this material out as soon as possible to reduce the overall risk. Everything at Sellafield is done with safety first and foremost in our minds.

“This is one of the nuclear industry’s most complicated engineering challenges being addressed before our very eyes. This is cutting edge technology at the world’s most complicated nuclear site.”

George Andrews, chief operating officer at Ansaldo NES compared the installation of the tunnel to a cup final.

He said: “We've all been working hard and closely for a number of years now and it's like scoring the goal in the FA cup final. It's a pretty significant event."

The Silo Emptying Plant is due to be operational by 2018 and will remain active until 2038 when the final radioactive material is set to be removed.

In October, Sellafield announced that it expects the silo to be cleaned up quicker and for about £1bn less than originally planned following a switch to a simpler method of treating and storing the material.