Tome Architecture and management of a geological repository - Andra

5 – B waste repository zoneFigure 5.5.23D view of modules on 2 levels5.6 Disposal process and feasibility elementsThis chapter distinguishes the activities simultaneously implemented during the B waste disposalprocess. The activities vary in kind:- on-going exploration aiming to define the disposal tunnel layout inside the granite blocks(cf. § 4.3.1);- construction of tunnels and disposal modules;- nuclear operation in the disposal tunnels, for package emplacement and reversible management ofthe structures.Moreover when the choice is made to close the disposal modules, the work to be carried out is similarto the construction activities.Architectural measures in the B waste repository zone are such that these various activities can beflexibly and simultaneously carried out.Along these architectural measures, the proximity of the modules to the main connecting drift allowsthe throughputs required by each of these activities to be organised at all points of the repository zone.5.6.1 Siting the disposal tunnelsThe B waste cells are installed in very low permeability granite blocks that favour a mainly diffusivetransfer mode in the near-field granite, and far enough away from the water-conducting faults – someseveral tens of metres away.The envelope of the blocks and their characteristics have been subject to detailed survey during apreliminary phase of the works (cf. § 4.3.1).Dossier 2005 Granite - ARCHITECTURE AND MANAGEMENT OF A GEOLOGICAL REPOSITORY139/228