Architecture and management of a geological repository - Andra

4 – Waste disposal PackagesLoadSlidingrunnerFigure 4.2.9 Sliding runner test bench Figure 4.2.10 Loaded sliding runnerTests carried out with a solid ceramic sliding runner demonstrated that the metal track underwentslight marking without metal detachment and that the load required for pushing was steady andstabilised at a value of half of the displaced weight, i.e. a friction factor of 0.5.For this type of ceramic, the sliding runners are shaped by pressing powder and then sintering i.e.raising to high temperatures for consolidation. After cooling, machining is required so that the partcomplies with rated dimensions. The part can be quite complex in shape. The material obtained hashomogenous characteristics with no residual stress.• Method for integrating ceramic sliding runners into disposal packagesIntegration of sliding runners in disposal packages must not affect the rated thickness of 55 mm ofsteel. This imposes an extra thickness of about 10 mm for installation of sliding runner emplacements.Two integration methods are possible: (i) direct bonding 47 of solid ceramic sliding runners in thesemachined emplacements with defined tolerance to obtain good mechanical resistance (especiallyresistance to shearing stress generated by friction applied to the metal sleeve), (ii) welding of slidingrunners of composite ceramic/metal type 48 inserted in these emplacements. The advantage of themetal part is that it can be welded to the extra steel thickness on the over-pack.4.2.4.3 Disposal package assemblyDisposal packages are assembled in a shielded cell:- The first operation consists of loading the primary package of vitrified waste into the container.Functional clearance provides ease of vertical loading by freeing up container manufacturetolerances and tolerances related to the primary package.- The lid is then placed on the container body. The ensemble is then inserted into an enclosurewhere the vacuum is effected, an operation required for electron beam welding. The container isthen rotated and orbital welding of the lid is carried out. Figure 4.2.11 shows a welding enclosureunder vacuum conditions and Figure 4.2.12 the electron beam welding process.4748Using high performance industrial glue.Firstly, solid sintered ceramic is produced then mechanically added to a metal base in order to obtain the composite ceramic/metalsliding runner.DOSSIER 2005 ARGILE -ARCHITECTURE AND MANAGEMENT OF A GEOLOGICAL DISPOSAL SYSTEM142/495