Tome Architecture and management of a geological repository - Andra

7 - Spent fuel repository zone7.5.2 Description of a repository moduleA repository module is a set of handling drifts and connecting drifts.Figure 7.5.1Schematic representation of a module for CU packagesThe handling drifts are served by a cluster of two to three connecting drifts that are dimensioned in thesame way as for C waste repository module to enable the module exploration, construction, operationand closure operations to be carried out successively (cf. § 6.5.2).A number of simulations have been carried out at this stage, to determine the module construction andoperating time. Estimated module exploration and construction time is two to three years longer thanmodule operation time, just as it is for C waste repository modules. It takes four to six years to preparea module for reference packages CU1 and about four years for a module for reference packages CU2,which will be operated respectively for eighteen months and two years [42].7.5.3 Assessing the number of spent fuel modulesWith no specific site data, an indicative estimate has been made of the number of modules in the spentfuel repository zone on the basis of the mean number of modules in operation over eighteen monthsfor CU1 and two years for CU2. For scenarios S1b and S1c, 18 modules are needed to host the CU2packages. This number would rise to 38 in the case of scenario S2 in which 24 modules would beexclusively dedicated to CU1.About fifteen blocks will have to be identified for two-level architecture in the case of scenarios S1,and 20-25 blocks for scenario S2.Dossier 2005 granite - ARCHITECTURE AND MANAGEMENT OF A GEOLOGICAL REPOSITORY213/228