The four cooling towers at the world's first full-scale nuclear power station - Calder Hall in Cumbria - have been demolished. Hundreds of people watched the 88-metre towers being blown up. They had stood there for 50 years, but were dismantled as part of the decommissioning of Calder Hall, which generated electricity for 47 years. Until 1995, the site had been used to produce weapons-grade plutonium.