Architecture and management of a geological repository - Andra

9 – Nuclear operating resources in the repositoryIn the case of B wastes, the size of the cell and the choice of piling the packages one on top of theother requires a large-sized machine that cannot be included in the transfer cask. The machine chosenis a fork-lift type truck stationed at the head of the cell.In all three cases, the function of radiological protection for personnel during the whole process (inboth normal and malfunction conditions) is ensured by the protective transfer cask and the fixedequipment at the head of the cell onto which the transfer cask is docked.9.3.2 Description of the equipment and process of installing packages of B wastes9.3.2.1 Design principles• Required functionsDisposal package of B wastes are characterised by a weight varying from 6 to 25 tonnes, a volume ofabout 4 to 10 m 3 and a contact dose rate that can reach 5 600 mSv/h for the most radioactive of them.The handling of heavy, radioactive packages piled in several vertical and horizontal layers in a largesizedcell (250 metres long) requires a remote-controlled mobile machine capable of moving the loadin the cell's three dimensions, i.e. longitudinally, laterally and vertically. This machine must also becapable, when depositing the packages, of a precision compatible with the functional clearancebetween the packages and the cell wall that is of the order of 10 cm. This machine must be able to turnthrough 180° to change from the position of "facing the transfer cask" to the position of "facing thecell".Furthermore, the existence of a mobile machine operating in an irradiated environment requires aradiological protection airlock to ensure the radiological protection of personnel when the machine hasto come out for maintenance or other operations. This airlock also allows it to be recovered when thecell is full.A first feasibility study has led to the identification of three essential components to fulfil the functionsdescribed above:- mobile handling equipment responsible for the function of transferring the packages from thetransfer cask to its final position in the cell,- radiological protection airlocks to ensure the function of radiological protection for personnel,- fixed equipment situated in the radiological protection airlocks to facilitate the machine'smovements when transferring the packages.DOSSIER 2005 ARGILE -ARCHITECTURE AND MANAGEMENT OF A GEOLOGICAL DISPOSAL SYSTEM345/495