Architecture and management of a geological repository - Andra

9 – Nuclear operating resources in the repository9.1.3 Preparing C waste disposal packagesPreparing the C waste disposal packages takes place over the following stages:- The empty over-pack is taken from the storage warehouse to the conditioning line. Before enteringthe packaging cell, the over-pack and its lid are demagnetised as required for the electronic beamwelding.- The primary packages are then placed in the over-pack in a loading station, using a specificgripping system. The lid is positioned and the whole is transferred to the welding chamber.- The lid is welded. The process adopted for closing the C packages is electron beam welding. Thistechnology requires the elements being welded to be placed in a vacuum. This process wasdescribed in the chapter relating to C waste disposal packages (see Section 4.2). The weldingmachine consists of a chamber, a pumping unit and a welding gun. The lower section of thepackage reception chamber, about 3 m3 in total, is fitted with a turntable on which the packagestarts to rotate. The chamber head has a door fitted with seals so that the container can beintroduced by the top and the chamber closed and made leaktight. The welding gun, with anestimated power of 45 kW and a travel speed of 10 to 15 centimetres per minute, carries out thewelding operation in a single pass of around 20 minutes.- Checks are then carried out on the weld and for non-contamination (described in Section 4.2). Asfor the B packages, the C packages declared non-conforming are transferred to a specificprocessing cell to retrieve the primary packages so that they can be returned to the cell to bereconditioned.- The conforming packages are stored in a temporary storage room before being transferred to theunderground installations.These operations are performed in a series of shielded cells illustrated by the diagram in Figure 9.1.6.DOSSIER 2005 ARGILE -ARCHITECTURE AND MANAGEMENT OF A GEOLOGICAL DISPOSAL SYSTEM333/495