Architecture and management of a geological repository - Andra

6 – Overall underground architectureA separation of the air ventilation circuitsThe nuclear operation drifts have a fresh air supply independent from that of the construction drifts inorder to prevent the dusts and smoke generated by the construction activity from entering. On theother hand, the air return and smoke removal circuits can be common to both types of drifts becausethere is no risk of radioactive substances being spread by the nuclear operation processes implementedin the repository installations (transfer of the waste packages into the drifts and emplacing in the cells).However, the ventilation circuit of the package transfer shaft makes up a separate circuit independentfrom the other ventilation circuits in order to guard against the consequences from a package falling ina shaft (see chapter 11).• Ventilation modelThe ventilation model (Figure 6.4.6) consists of several branches between the pressurised air intakeshafts and the depressurised air exhaust shaft.Figure 6.4.6Ventilation principleDOSSIER 2005 ARGILE -ARCHITECTURE AND MANAGEMENT OF A GEOLOGICAL DISPOSAL SYSTEM275/495