Architecture and management of a geological repository - Andra

6 – Overall underground architectureThis drawing represents a situation where two cells are being constructed, three cells are being filled,and two cells are already filled. Ventilation barriers separate three sectors :- The construction sector,- The operation sector, which contains the cells being filled and those already filled,- The air exhaust drift sector, which includes two compartments : general air exhaust and smokeremoval.The pressurised fresh air arrives in full section through the construction drifts and the package transferdrifts to supply their respective sectors. The air of the cells is evacuated through the depressurised airexhaust drift.6.4.4.3 Ventilation of the C waste repository zones (or spent fuel repository zones)The drawing below shows the ventilation principle of a C waste repository sub-zone, where theoperating units are drift triplets.Figure 6.4.9Ventilation of the C waste repository zoneThis drawing represents a situation where two working units are in construction and one unit is inoperation. There are thus two sectors of activity, a construction sector and an operation sector. Thesetwo sectors are separated by a series of light bulkheads, some of which are equipped with an air lockwhich the operating personnel can go through 111 .The first working unit is in the excavating phase. Temporaryair ducts ensure the exhaust of air fromthe excavating worksites. The second operation unit is in the cell excavating phase; it is ventilated infull section according to the same principle as that of the units in operation described in section 5.2.4.The air exhaust of the various working units are connected to the air exhaust ducts of the connectingdrifts (construction drifts or package transfer drifts). Within the sub-zone, these ducts ensure the airreturn and smoke removal functions and are interconnected.111 The air pressure difference is small between these two sectors and, therefore, compatible with the air lock installation.DOSSIER 2005 ARGILE -ARCHITECTURE AND MANAGEMENT OF A GEOLOGICAL DISPOSAL SYSTEM278/495