Tome Architecture and management of a geological repository - Andra

6 – C waste repository zone6.6.4.1 Cask transfer in the underground installationsCask transfer in the shaft between the surface and underground is similar to B waste cask transfer(chapter 5). Once the cask is removed from the cage at the repository level, it is placed on a transfershuttle that takes it right above a disposal cell.This type of shuttle technology has been used at COGEMA’s La Hague site for many years.The shuttle basically consists of a wheeled vehicle and a moving chassis that suspends the cask whiletravelling and adjusts the cask opening alignment to the borehole axis when docking onto the disposalcell.Figure 6.6.6Shuttle in a handling driftThe vehicle is fitted with multi-directional wheels, each one with independent hydraulic motorisation,thus providing very tight turning circle. Each of these wheels has its own hydraulic lifting devicewhich, in synchronisation, can lift or lower the loading deck with the cask. The total mass of theloaded shuttle is about one hundred tonnes.6.6.4.2 Emplacing the packages in a disposal boreholeWhile docking the cask to a disposal cell (vertical borehole) head, additional radiological protectiondevices, similar to those at La Hague are used: a thick elastomer leaded seal fixed to the lower part ofthe vessel, and fixed or removable metal plates installed at the cell head.Before the shuttle arrives, the cell head protection device is removed. Once the shuttle is positionedover the cell head, the loading deck is lowered. Final alignment of the cask opening with the cell axisis adjusted using the translation systems of the moving chassis that holds the cask. The cask is thendocked by lowering the jacks integrated to the moving chassis.Disposal package emplacement in the borehole is carried out in the following sequence (Figure 6.6.7) :- grasping a package or plug in the cask;- revolving the barrel to line up the deck opening and cask axes;- emplacing the package in the borehole then retracting the empty clamp into the cask.Dossier 2005 granite - ARCHITECTURE AND MANAGEMENT OF A GEOLOGICAL REPOSITORY187/228