Architecture and management of a geological repository - Andra

9 – Nuclear operating resources in the repositoryIt should however be pointed out that the principle described above is not the only solution to theproblem posed. The relevance of shifting the load that is required by use of two vehicles couldeventually be re-examined.9.2.4.2 Transfer of the transfer casks in driftsThe diagram in Figure 9.2.7 illustrates the design ofthe transfer casks transfer vehicle.The feasibility studies have led us to propose a fewprinciples for this low-slung vehicle resembling anelectric fork-lift truck on pneumatic tyres.The "low-slung" character enables the outsidedimensions of the combination of vehicle and transfercask to be reduced and thereby also reduces therotating radius and the cross-section of the drifts. Theload-bearing platform can be raised or lowered for theloading and unloading operations. It is equipped withindependently motorised wheels that can turn in alldirections to have a very small turning circle.Electrical energy is preferred to a diesel motorbecause of the fire hazards inherent in the latter typeof motor.Finally, the principle of pneumatic tyres waspreferred to a vehicle on rails. The use ofvehicles on tyres avoids the construction andmaintenance of a rail network. Using vehicles onpneumatic tyres also enables the drifts to havetighter bends than with vehicles on rail.It should be noted that this type of vehicle is atechnique that widely exists and has been provenin the nuclear context. Such vehicles areproduced by several European manufacturors.Figure 9.2.8 shows an example of thistechnology used for several years at the Cogemasite at La Hague.Figure 9.2.7 Transport vehicle of a caskof B wasteFigure 9.2.8 The transfer vehicle used on theLa Hague site (doc from Cogema)9.2.4.3 Docking of the transfer casks in the cell headsThe docking of the transfer casks at the cell heads is conducted by a specific vehicle: the "dockingshuttle". There is a specific shuttle for each type of transfer cask (B, C and CU). The special featuresof these three shuttles are related to the docking process of the three types of transfer cask and to theassociated docking mechanisms. They have similar design principles to those of the transfer vehicledescribed above.The docking of B transfer casks is conducted in the same direction as the shuttle's axis of motion.After being deposited by the transfer vehicle, the transfer cask is picked up by the shuttle, then travelsalong the drift giving access to the disposal cell and docks on a window equipped with metal doors,fitted into the wall of the radiological protection airlocks at the head of the cell.DOSSIER 2005 ARGILE -ARCHITECTURE AND MANAGEMENT OF A GEOLOGICAL DISPOSAL SYSTEM343/495