Architecture and management of a geological repository - Andra

7 – The shafts and the driftsThe drifts travelled through by high power electric vehicles are equipped with overhead electric lines.The size constraint of this overhead electric line system, which must allow a radial clearance for thetrucks to pass by other vehicles, such as emergency vehicles, does not allow the installing of largesection ventilation ducts 122 .Figure 7.4.6Construction drift with track• Construction drifts equipped with railwaysThe main function of these drifts is to ensure the transport of broken rocks, concrete and backfillsbetween the shafts and the repository working units in operation for the C waste repository zone andpossibly the spent fuel repository zones.They are equipped with two metric-gauged railways connected by crossings – junctions, overheadelectric lines, large section ventilation ducts (approximately 7 m 2 ) and network installations.• Air exhaust driftsThe main function of these drifts is to ensure under normal conditions the exhaust of air from theconstuction and operation worksites to the air exhaust shaft. According to needs, they can also beequipped with smoke removal ducts.These drifts do not have equipment other than that required by ventilation or smoke removal needs.The presence of personnel in these drifts is strictly limited to maintenance requirements and assumesthe suspension of upstream construction or operation.7.5 Construction of shafts and connecting drifts7.5.1 Construction of shaftsThis section briefly reviews the various shaft sinking techniques in industrial use and then describesthe favoured method by indicating, if necessary, the possible variants of this method.122 On the other hand, the electric power systems of the package transfer vehicles and the railways require hardly any or no axial clearanceand are much less bulky.DOSSIER 2005 ARGILE -ARCHITECTURE AND MANAGEMENT OF A GEOLOGICAL DISPOSAL SYSTEM304/495