The effort to demolish a 530-ton filter gallery on top of the a massive chimney at Sellafield has passed the half way point, site license company Sellafield Limited announced yesterday. The large filter gallery must addressed at the last remaining Windscale chimney before it can be brought down. The 110 meter chimney was a ventilation shaft for a reactor which suffered a core fire in 1957, increasing contamination. “The contaminated filters themselves were removed not long after the fire and the chimney was then sealed up to allow the radiation to decay. We’re now working to dismantle the filter gallery itself, which provided access to change and clean the filters,” Pile Chimney Demolition Project Manager Chris Wilson said in a statement. “The filter gallery is a large, robust structure built of steel, brick and concrete at the top of the chimney. We’re using conventional demolition techniques common in other industries but in an unconventional environment at the top of a nuclear chimney.”
About half of the filter gallery has been brought down, including 150 tons of concrete, 175 tons of steel and 66 tons of brick. The current schedule calls for completion of the gallery by October, followed by the demolition of the 1,400 ton diffuser box in 2017 to 2018. “The decommissioning challenges posed by the Pile chimney are unique and no other structure in the world provides the same complexity in terms of both radiological and conventional decommissioning constraints,” Head of Decommissioning Projects Jeremy Hunt said in a statement. “There’s no instruction manual for the job and we have to prove the decommissioning techniques chosen can be used 100 percent safely on the congested Sellafield site.”
