Architecture and management of a geological repository - Andra

4 – Waste disposal PackagesAs for C packages, manufacture is carried out in two phases. The first one consists of the in-plantmanufacture of container components. The second phase consists of placing the fuel assembliesreceived bare or in individual cladding in the container, welding of the plug inside the body andclosing the disposal package by welding its lid with electron beam. This second phase must be carriedout in a succession of shielded cells for protection against exposure to radiation.4.3.4.1 Plant manufacture of containers and lidFigure 4.3.10The two versions of large diameter container with cylindrical and squareemplacementsAs mentioned above, the components to be manufactured are the shell made of non-alloy steel (P235)110 mm thick, the insert equipped with four emplacements (cylindrical or square), the bottom, lid andintermediate plug. For small diameter containers, this involves a shell made of non-alloy steel (P235)with rated thickness of 120 mm, a bottom, a lid and an intermediate plug.The various techniques analysed (c.f. section 4.2) for the manufacture of C waste over-pack body arealso envisaged for the spent fuel repository container body. As for the manufacture of the C over-packbody, two techniques have been identified as particularly appropriate: (i) forging of the shell andwelding of the built-up bottom (ii) drilling-drawing to obtain a body in one single piece withintegrated bottom.At this stage, due to large package dimensions and to facilitate insert manufacture, the techniqueadopted for demonstrators uses a built-up bottom welded onto a shell obtained from forging a block ofsteel.Shell forging is illustrated in Figure 4.3.11, with photographs taken during demonstrator manufacture.Figure 4.3.11Manufacturing stages of shell in non-alloy steelThe figure on the left shows the blank placed under a press which carries out forging operations andthe figure on the right shows the finished product machined to final specifications.DOSSIER 2005 ARGILE -ARCHITECTURE AND MANAGEMENT OF A GEOLOGICAL DISPOSAL SYSTEM154/495