Architecture and management of a geological repository - Andra

5 – Repository Modules- another possible process would consist of compacting clay pellets or powder in-situ; it would bedone in the same way as the solution described for the type C disposal cell.At this stage, the prefabricated component solution appears to be the simplest.The next phase consists of producing the retaining plug. Unlike for the type C disposal cell, part of theretaining plug is already in place before closing the cell (prefabricated concrete rings). Closingtherefore consists of pouring an additional concrete plug in the central space and, if necessary,injecting the concrete/concrete and concrete/lining contacts.Figure 5.3.19Procedure for removing the sleeve and simultaneously fitting the swelling clayplug5.3.4 Layout of the type CU1 and CU2 cells in the repository moduleThe layout of type CU1 and CU2 repository modules, as presently proposed, is very similar to that oftype C modules. Each module consists of two work units, each work unit grouping together threeaccess drifts. The only difference is the number of cells and the details of the secondary infrastructuredrifts.Type CU1 and CU2 modules contain 80 to 130 disposal cells.In order to take flow hypotheses into consideration it is proposed that five secondary infrastructuredrifts be excavated in type CU1 repository zones and four in type CU2 zones. The additional drift intype CU1 zones is an air return drift, justified by operational requirements 100 .100 An increase in the internal diameter of 1 m would allow the number of secondary infrastructure drifts to be reduced from five to four intype CU1 zones.DOSSIER 2005 ARGILE -ARCHITECTURE AND MANAGEMENT OF A GEOLOGICAL DISPOSAL SYSTEM249/495