An ingenious demolition technique is being used to remove the tallest structure at Europe's oldest nuclear facility.

The engineering team entrusted with the demolition of a high-rise chimney at the Sellafield nuclear reprocessing site in Cumbria is making use of a self-climbing platform to ensure that the challenging process is safely and successfully completed.

The 61-metre high chimney stands on top of a reprocessing plant which itself rises to a height of 11 storeys. This brings the total distance from ground to chimney top to 122 metres, making it the tallest historic structure on the site since its construction in the 1950s.

The difficulty of demolishing the towering chimney is compounded by its location at the centre of the busiest section of one of Europe’s oldest and most complex nuclear facilities, precluding the use of munitions.

In lieu of explosives, Sellafield’s demolition team will employ a unique, self-climbing platform to gradually dismantle the immense structure, which is set to be replaced with a new Separation Area Ventilation Stack (SAV).

“The job of bringing down the stack is going to be a delicate operation to ensure 100 per cent safety of all personnel and surrounding nuclear plants,” said project manager Matthew Hodgson. “Because we can’t use explosives, we will use an ingenious self-climbing platform which will bring the chimney down bit by bit in a controlled manner.”

According to Hodgson, the demolition process has required several years of planning in collaboration with a slew of other companies, and will entail the construction of an industrial lift and accompanying bridge structure to remove a total of 600 tonnes of concrete and rebar, as well as 25 tonnes of steel.

Battersea Power Station

“We have employed Nuvia Limited who has been working with us and a number of other contractors, including Delta Steeplejacks, for the last three years on the demolition scheme,” said Hodgson.

“Demolishing this chimney will represent a very visual demonstration of our commitment to tackling one of the most guarded parts of Sellafield’s legacy,” said Steve Slater, Sellafield’s head of decommissioning. “The plant was built in the shadow of the war to secretly produce nuclear materials for the UK’s defence programme.”

The self-climbing platform technology is already being applied to demolition work at another landmark industrial site in the UK – the Battersea Power Station on the banks of the River Thames.

The 103-metre chimneys of the Battersea Power Station are in a state of advanced decay and at risk of collapsing, posing a major threat to plans to convert the site into a combined office, residential and retail space.

Use of the technique will enable the hazardous chimneys to be removed while still preserving the integrity of the underlying structure, while the 2,400 tonnes of concrete salvaged from the demolition process will be crushed and used for the redevelopment scheme.