Valognes incident (1998)
Air flowing over the fins on the surface of transport cask cools the spent fuel inside it. As spent fuel is loaded underwater for radiation protection reasons, the cask's surface may be contaminated by the radioactive elements present in the water in the pool in which the loading operation is performed. This surface contamination is removed by intense, thorough rinsing. The contamination observed during the incident in 1998 was due to inadequate rinsing. Rinsing performance monitoring was upgraded following the Valognes incident.
Philippe Lesage/AREVA