THE TNF-XI: A NEW GENERATION PACKAGE FOR U OXIDES

Generally speaking, the existing packages in use for the transport of uranium oxides are quite “old” designs which have been more and more questioned by Competent Authorities worldwide. For some of them, the authorized payload had to be reduced for safety assessment reasons. These packages now need to be replaced. On behalf of Nuclear Fuel Industries, Ltd., Transnucléaire is in charge of the design of a new generation package: the TNF-XI design. As for every new type of package, one of the most important requirements is to maximize the payload / production price ratio and to make the operation and maintenance costs as low as possible. The design, which started mid 2000, is thus conducted with three guidelines. The first is to use the most recent Transnucléaire technology: specific non-corrosive foams, high performance criticality control resin and user-friendly closing devices. The second is to demonstrate its safety capability under the most penalizing condition. The third is to benchmark the serial production cost every time the basic design has changed in a way that can impact its price. Taking into account the existing sites interfaces and UO2 powder conditioning arrangements, the expected performance of the package is to transport six UO2 tons per 20-foot ISO container by loading 20 TNF-XI packagings: On a safety and licensing point of view, lessons have been learnt from the past. Indeed, it appeared in the last few years that approaches regarding demonstration of compliance with the regulations for fissile packages could vary from one national competent authority to another. Such packages having an extremely international life, the choice has been made to consult the relevant authorities at an early stage of the project. The aim is to consider their experiences and recommendations before the design and the associated methods of demonstration with the regulations have been definitively fixed. The TNF-XI fleet should be in operation starting end of year 2002.