Architecture and management of a geological repository - Andra

5 – Repository Modules• Arrangement of packages in the cellAll the disposal packages placed in the same cell have the same dimensions 69 . According to their size,they are arranged on 3 or 4 levels and over 2 to 4 columns in the crosswise direction of the cell (Figure5.1.15). A clearance of 15 cm is left between the top of the packages and the roof of the handlingchamber. A clearance of 10 cm is left crosswise between the package columns and between thepackages and the vertical walls of the handling chamber. The clearances are reduced to the minimumin the longitudinal direction. These clearances are sufficient for package handling and cell ventilation.With this spacing, the gaps between packages represent approximately 5% of the excavated section ofthe cell. It should be noted that it would be possible to reduce these gaps still further by inserting afiller block about ten centimetres thick above each stack of packages, and by reducing the spacingbetween package columns through improving the precision of the handling system.Figure 5.1.15Arrangement of packages in the cell• Description of the equipment of the cell head (before sealing)B cells are equipped with an airlock at the cell head (Figure 5.1.16). Its function is to provideradiological protection for personnel during operations for extracting packages from their transfertransfer cask and disposal (or withdrawal). The handling equipment used for these operations isremotely controlled from outside the airlock.The airlock is formed by two doors. The outer door (on the access drift side) is equipped with awindow onto which the transfer transfer cask is docked. This door is also used for the exit and entry ofthe handling truck in the airlock. The inner door (on the cell body side) is formed of several slidingpanels for the passage of this same truck for transferring packages to their repository location in thecell. The airlock thus formed between the two doors is fitted with a moving floor and a rotating table,which enable the handling truck to manoeuvre in a restricted space.The airlock is ventilated via ducts connected to the pipes in the cell body and via shielded baffles inthe airlock doors.69In some instances, packages of the same height and width (crosswise to the cell) but of different lengths (lengthwise to the cell) can beused. In this case, the packages are arranged by homogeneous zones within the cell.DOSSIER 2005 ARGILE -ARCHITECTURE AND MANAGEMENT OF A GEOLOGICAL DISPOSAL SYSTEM175/495