COG-OP-30B: A New COGEMA Overpack for Type 30B Cylinders

Abstract

Facing the difficulties encountered in the United States of America in obtaining a durable certificate of approval for the existing overpacks, COGEMA desired to free itself from the constraints imposed by these packagings for the transport of enriched uranium hexafluoride. Transnucl6aire therefore initiated the design of a new Type B(U)F overpack, on behalf of COGEMA, for use with the 30B cylinders containing uranium hexafluoride enriched up to 6% in ²³⁵U, obtained from natural or reprocessed uranium. The external aspect of the new overpack is quite standard (two cylindrical halves closed with ten toggles) and it keeps the same stowage system so that it can be used with the methods of transport which exist already. The main features of COGEMA's overpack are a reinforced internal structure to protect the 30B cylinder's skirt from bending and better absorption of the drop energy to limit the acceleration under impact. The drop tests and a fire test were performed successfully in February and March 1997, the French Certificate of Approval was obtained at the end of 1998, the Swedish validation by mid-1999 and the Canadian validation at the beginning of 2000.