Architecture and management of a geological repository - Andra

5 – Repository Modules• Assembly method for sleeve tube componentsThe sleeve components can be connected using various techniques:- Automatic welding of tubes with similar dimensions. This technique is well proven (pipelinelaying) but it is the longest to implement in the case of C waste disposal cells.- Threaded connections enable quick implementation. However, fewer references are available forthis technique and its cost is higher.- Connections via mechanical locking are particularly adapted to site conditions (fastimplementation, rotation equipment of no use).At this stage, the automatic welding solution seems interesting since it benefits from a very largeamount of experience feedback.5.2.5.2 Description of complete construction solutionTaking into account the preceding sections, the following is a construction solution [65] (See Figure5.2.19) :- The disposal cell is drilled using a tool followed by a tube that supports the terrain and is left inplace to constitute the sleeve.- The sleeve components are pushed by a tube pusher installed on the drill. They are progressivelywelded together upon their insertion. The drill – tube pusher assembly rests on the thrust framesecured in the access drift. The sleeve is pushed without rotating inside the terrain.- The peripheral bits are retractable. Set in spaced position for the drilling, they give the excavationa diameter slightly exceeding that of the sleeve. They are retracted at the end of the drilling so asto withdraw the tool inside the sleeve.- The bottom of the sleeve is then sealed by welding a plate on it.These various phases and the associated equipment are described below.Upon completion of these operations, the head of the disposal cell is fitted with the equipmentrequired for its operation (shielded trap door).Figure 5.2.19C waste disposal cell excavation sequenceDOSSIER 2005 ARGILE -ARCHITECTURE AND MANAGEMENT OF A GEOLOGICAL DISPOSAL SYSTEM219/495