Architecture and management of a geological repository - Andra

6 – Overall underground architectureSegments of zone B drifts that run parallel to the main horizontal stress are sealed with argillite plugs.The seals situated in the cell access drifts ensure the zone is compartimentized into one-cell modules.Seals situated in connection drifts separate B zone from other repository installations.6.2.6 Description of the C waste and spent fuel repository zonesFigure 6.2.3Layout of a C (or spent fuel) repository zoneThe layout of C Waste (and, where applicable, spent fuel) repository zones is similar. Their design anddimensioning are greatly conditioned by thermal considerations.In order to facilitate the organization of their construction, operation and closure, these zones are splitinto sub-zones, each of which is then subdivided into 8 to 12 operating units.Each operating unit comprises 80 to 220 cells. The space between the cells is defined by thermaldimensioning (see Chapter 5).The operating units comprise 3 parallel drifts, the cell access drifts, connected to the connectingdrifts. These access drifts are connected to each other by perpendicular interconnecting drifts. Thislayout of drifts in threes ensures a high degree of ventilation operational safety even in the event offire.Zone C is sealed with argillite plugs located in structures that run parallel to the main horizontal.• Special case of C0 (and CU3) packagesC0 type C packages, which are significantly less exothermic than other C packages, are assigned to aspecific sub-zone with only one module. This would also be the case for CU3 type fuels, if applicable.DOSSIER 2005 ARGILE -ARCHITECTURE AND MANAGEMENT OF A GEOLOGICAL DISPOSAL SYSTEM262/495