Architecture and management of a geological repository - Andra

4 – Waste disposal Packages4.3.4.2 Insert manufacture for large diameter packagesThe grade of cast iron is selected to facilitate manufacture. Care was taken to limit the cast ironshrinkage during cooling after casting, so as to minimise clearance between the steel shell and insert(for overall mechanical performance) 56 .Direct pouring of the cast iron into the steel envelope was selected because it can minimise theclearance more easily.The first stages of production of the cast iron insert consist of making a set of four tubes, illustrated inFigure 4.3.12, as part of the demonstrator programme.Figure 4.3.12Preparation for insert castingAfter the tubes are put together using welded spacers; the ensemble is vertically lowered into thecasting shaft, then each tube is filled with sand.Once the forged shell has been placed around the four tubes, a pouring basin is placed at the top of theshell to spread the melted cast iron inside the shell.Casting operations carried out for the demonstrator are illustrated in Figure 4.3.13.Figure 4.3.13Insert casting56The type of cast iron is grey iron (GJL150) (G for moulded part, J for cast iron, L for graphite structure and 150 for resistance in MPa)with carbon and silicon content favoring graphite expansion to limit steel/cast iron interface clearance.DOSSIER 2005 ARGILE -ARCHITECTURE AND MANAGEMENT OF A GEOLOGICAL DISPOSAL SYSTEM155/495