Tome Architecture and management of a geological repository - Andra

5 – B waste repository zoneFigure 5.2.1Japan: general architecture of a deep TRU waste in crystalline rock and abituminised or low-level waste storage tunnelThe horizontal package handling option is adopted as the reference in the studies out of the sameconcern for compactness and reducing the clearances left over after disposal in the tunnels. By optingfor this choice the overall volume in the cell can be reduced, avoiding the need for a clearance (that theinstallation of an overhead crane requires in the upper part of the tunnel) that cannot be used fordisposal.Given the mechanical properties of the granite, the dimensions of the tunnels can be quite large, whichcontributes to the objective for repository compactness [35].Dimensioning for all B waste is essentially governed by the operational safety requirements in relationwith package emplacement and package drops prevention (cf. § 5.3). In the case of slightly exothermicwaste (B1 and B5), dimensioning takes also into account temperature criteria for the long-termbehaviour of the concrete of the packages and the radionuclide behaviour inside the cells (cf. § 5.2.2).Thus the cell architectures studied are disposal tunnels about ten metres high, and ten to twenty metresacross (cf. § 5.4). The tunnel lengths can be adjusted to both the waste characteristics and inventoryand the granite fracturing. They vary from 70-200 metres.Dossier 2005 Granite - ARCHITECTURE AND MANAGEMENT OF A GEOLOGICAL REPOSITORY115/228