BEST PRACTICES IN MINIMISING SURFACE CONTAMINATION: A DISCUSSION OF BRITISH ENERGY’S OPERATIONAL EXPERIENCE WITH IRRADIATED FUEL TRANSPORT FLASKS

British Energy and its predecessor companies have been transporting irradiated fuel in specifically designed transport flasks between nuclear licensed sites within the UK since the 1960s. Minimising external contamination on fuel flasks has always been a high priority and sometimes a challenging task. This was particularly so around the turn of the century when the UK nuclear industry was tasked with addressing, and correcting, an increase in the number of flask contamination occurrences. This was tackled on several fronts, one of which was to identify and implement best practice. This has been formulated into a best practice guide, the principles of which are relevant to all fuel flasks, not just British Energy’s. These principles, listed below, are discussed. • Ensure flask surface finish is kept in good condition • Minimise pond activity and immersion time • Ensure the flask is physically clean before placing in the pond • Pre wet the flask before placing in the pond • Hand towel immediately after removal from the pond • Wash in warm water using an approved decontaminant • Rinse after drying and towel dry • Minimise cross contamination possibilities • Survey the flask prior to despatch, trend survey results • Minimise the time between survey and despatch • On arrival survey the flask with minimum delay • On arrival dry swab the correct area using light finger pressure • Investigate contamination incidents and trend near misses • Ensure the staff are trained and familiar with the requirements • Ensure that staff and management are clear of the priorities, standards and expectations Operational experience since the introduction of the best practice principles has been good, with a significant reduction in the number of contamination events. The main conclusion is that “Following the agreed process and ensuring the flask is despatched clean is more important than ensuring that the flask catches the scheduled train”. This needs to be the clear expectation that is set and taken into account when developing performance indicators.