R75 TYPE B(U) PACKAGE: A ROBATEL'S NEW DESIGN FOR THE CLUSTER GUIDES TRANSPORTATION FROM EDF'S NPPS

As part of the maintenance of its French NPPs (Nuclear Power Plants), EDF/UTO (Operational Technical Unit of Electricité De France) commissioned ROBATEL Industries to design and manufacture a new Type B(U) transport package in order to remove cluster guides to be renewed. These are stainless steel assemblies which are contaminated and activated under neutron flux. They have various geometries depending on the different NPPs where they come from (about 300 kg and 4.5 m long). This package of 24 tons called R75 will transport by road under exclusive use up to 5 items between the various NPPs and the Hot Operational Base of Tricastin in Vaucluse, France. With its old nuclear history of more than 50 years and its strong experience in the design of radioactive material transport package (with about 80 approved type casks designed over the past 20 years), ROBATEL Industries has put its technical knowledge to serve a cask's design that integrates not only the regulatory requirements and the specific needs of EDF but also the technical innovations able to meet the latest expectations of the Safety Authorities. This paper therefore aims to present, through the example of the R75 packaging, how ROBATEL Industries develops innovative solutions both regarding the designs that the safety studies to continually improve its concepts and their relevance to the safety imperatives. That is specifically the case for such topics as the effects of an internal impact on the closure system (due to potential movements of the contents during an accident), the contaminated dusts containment (depending of the knowledge degrees and of the operational control capabilities regarding their activity level) or compliance and representativeness of the conditions of the realized drop tests (with those required by the regulations for the real package). For each of these points mentioned as examples, the safety justifications have constantly to fit to take account on one hand of the ever-increasing expectations of the Nuclear Safety Authorities and on the other hand of the progress of the scientific knowledge.