60-year old Sellafield chimney undergoes demolition by hand
Image credit: Sellafield Ltd
Engineers have begun the challenging task of demolishing one of the largest hazards at Sellafield, a decades-old ventilation chimney.
Sellafield is a nuclear decommissioning and fuel reprocessing plant on the old site of Windscale and Calder Hall near Seascale, Cumbria. The vast majority of Britain’s nuclear waste is processed at Sellafield.
The 60-year old tapered chimney stack undergoing demolition is located on top of the site’s First Generation Reprocessing Plant, and was used to provide ventilation during reprocessing of used nuclear fuel. According to a press statement, the chimney is a priority for removal, due to no longer meeting modern construction safety standards.
Until recently, when a modern replacement was built, it was the tallest structure on the site at a height of 61m. Until the replacement ventilation and discharge system had been built, Sellafield engineers were unable to touch the ageing chimney.
This is a challenging task which has required four years of preparation: due to Sellafield being a crowded environment full of serious hazards, engineers were not able to use conventional cranes and explosives to demolish the tower, which is at the heart of the site.
Instead, Sellafield and its contractors assembled a self-climbing circular platform by the chimney which is held in place by friction, and which functions as a podium for workers to safely access the chimney and gradually demolish it. This process is being painstakingly carried out by hand using drills, hydraulic breakers, concrete crunching jaws, plasma steel cutting torches and other equipment.
Beginning in October, the chimney is being removed at a pace of one metre every week, until it has been completely removed by 2020.
“Given the structural integrity of the stack, its location in the heart of the site and the fact that this new technique has never been used here before, the planning has been comprehensive,” said Stuart Latham, head of remediation at Sellafield.
“The project demonstrates the challenges of decommissioning the Sellafield site.”
The Sellafield site has made headlines in recent years due to allegations that its operations are not adhering to safety standards, with nuclear material handled improperly and the facility being understaffed.