Characterization of the Back-End Wastes in View of their Transportation

The designer of a packaging has to face two main problems: to fulfill the goal set forth by the user and to meet the safety requirement defined by the International Atomic Energy Agency (IAEA) and Competent Authorities. The demonstration of the second point is brought by the Safety Analysis Report of the package. This document must include a description of the packaging and of the content. When the transport takes place, the consignor has to demonstrate that the characteristics of the material to be loaded in the cask are not worse, as concerns safety, than the content described in the Safety Analysis Report. For this purpose, the description of the content will include a list of pertinent parameters allowing its characterization and clearly defining an \"allowable content\". These parameters must be as detailed as necessary and as simple as possible. But above all it must be possible to confirm, before shipment, that the package fulfills all safety criteria. Up to now, the main type B or type F packagings have involved fuel or radioactive sources which are particularly well defined and each packaging is dedicated to a given content. The parameters which characterize them are well known. For instance, for spent fuel assemblies, the list provides geometry of the assemblies (diameter of pellets, diameter and thickness of cladding, pitch of the rods), enrichment in uranium 235, burnup, specific power, cooling time , ... This type of material is well defined and is followed throughout its life by a Quality Assurance system, allowing a perfect knowledge of its characteristics and of its history. Because nuclear energy is now long established, more and more shipments and packagings are concerned by waste generated by the back end of the fuel cycle. The definition and characterization of the wastes are not so easy. One reason among others, for instance, is the waste processing, which generates a mixture of products of various origins. The paper describes some cases TRANSNUCLEAIRE had to face concerning high level, transuranic and irradiating wastes and the way they have been solved in order to provide the most reliable and flexible envelope characterization of the contents.