Architecture and management of a geological repository - Andra

Figure 10.4.13C Cell sealed• Prior cell head section reconditioning processThis process is distinguished from the previous one in that access to the package requires partialdeconstruction of the seal and reconstruction of the cell head section.Like in the previous stage, it starts with the cell atmosphere inspection. However, it shall be carriedout through the seal via a small-diameter bore. For safety purposes, this bore shall be performed in aneutral, air-locked atmosphere. Inspecting the atmosphere then allows to check the cell is incompliance with the expected state.Deconstructing the seal and reconditioning the cell head sectionDeconstructing the cell seal consists in removing the seal and installing a support casing (Figure10.4.14).The support casing is intended to facilitate later installation of the temporary sleeve. Thediameter of the support casing is 200 mm larger than that of the permanent sleeve to account for a 1%potential deviation of the boring axis. This operation may be performed using a horizontal boringmachine (external motor micro tunnel borer and retractable tool); installation is carried out when thesupport casing is fitted.Figure 10.4.14C Cell seal boringDOSSIER 2005 ARGILE -ARCHITECTURE AND MANAGEMENT OF A GEOLOGICAL DISPOSAL SYSTEM430/495