CALDER HALL COOLING TOWER DEMOLITION : Landmark Milestone for Decommissioning a t Sellafield - 8497

September 2007 saw a very visible cha nge to the Sellafield site following the culmination of a major decommissioning project; the demolition of the four Calder Hall cooling towers. A key part of the UK’s nuclear industrial heritage, Calder Hall, the world’s first commercial nuclear power sta tion, was opened by Her Majesty Queen Elizabeth II in October 1953 and continued to generate electricity until its closure in 2003. Following the decision to decommission the Calder Hall site, explosive demolition was identified as the safest and most cos t effective route for the removal of the towers. The technique, involving the placement of explosive in 60% of the circumference of both shell and legs, is a tried and tested method which had already been used successfully in more than 200 cooling towers i n the UK in the last 30 years. The location and composition of the four 88 metre high towers also create d additional challenges. Situated only 40 metres away from the UK’s only nuclear Fuel Handling Plant, as well as other sensitive structures on the Sell afield site, the project had to address the impact of a number of key areas, including dust, ground vibration and air over pressure, to ensure that the demolition could be carried out safely and without significant impact on other operational areas on the site. At the same time, the towers had to be prepared for demolition in a way that minimised the amounts of radioactive or hazardous waste materials arising. This paper follows the four year journey from the initial decision to demolish the towers right t hrough to the demolition itself as well as the clean up of the site post demolition. It will also consider the massive programme of work necessary not only to carry out the physical work safely but also to gain regulatory con fidence and stakeholder support to carry out the project successfully.