Cleanliness of transportation cask cavities

Within the framework of spent fuel assemblies (SFA) shipments from French NPPs to the AREVA La Hague recycling plant, unexpected foreign objects have been observed in the cavities of TN® 12/2, TN® 13/2 and TN® 112 casks.The authorized contents of these casks are limited to spent fuel, with the basket and the spacers so any other content is therefore forbiddenIn the event of the presence of any foreign materials in the cask cavities, the potential risks during transport are:• damage to the basket or to the fuel assemblies in the case of solid objects,• radiolysis in the case of organic material.Any discovery or suspicion of a foreign material must be declared to the French Competent Authority by the consignor, accompanied by the appropriate safety analysis.In 2010, EDF and AREVA set up a working group to identify the origin of these foreign materials and find solutions to improve the cleanliness of the cask cavities and thus transport safety.This paper presents the objectives of the AREVA / EDF working group and will describe the different steps of the work performed and the processes followed in order to understand the foreign materials’ origins. Main correctives actions are presented as well as the successful results of the implementation of these actions.