Architecture and management of a geological repository - Andra

3 – High Level Long-Lived WasteThe second group of packages (55% of the inventoried bitumen packages) consists of 428-litrestainless steel drums, also known as "EIP" overdrums 22 . These drums (see Figure 3.2.4) are used asoverdrums for primary non-alloy steel drums produced at the STEL between 1966 and October 1996.Figure 3.2.4Stainless steel drum used as overdrum for primary non-alloy steel drumsThe study takes the hypothesis that the interstitial gap between the two drums is completely filled witha non-compressible material, such as mortar, in order to limit the long-term mechanical deformation inthe repository.On average, the weight of conditioned waste per package is 220 to 240 kilograms, including roughly90 kilograms of dry extract and 130 kilograms of bitumen. The average weight of the finishedpackages is 240 kilograms for STE3/STE2 and STEL packages and 330 kilograms for STEL packageswith overdrum.3.2.1.3 Cemented or compacted technological wasteA third group of waste is technological waste resulting from the operation and maintenance of nuclearfacilities by COGEMA and the CEA. This consists mainly of various kinds of solid waste (variousmetals, organic materials), but also includes filtration sludges and evaporation concentrates. Thisgroup also includes various waste produced at Marcoule such as graphite, ion-exchanger resins andzeolites. The radiological activity of waste, especially of technological waste, is usually due surfacecontamination of the waste by fission products and/or activation products and/or actinides.The conditioning process for this waste depends on its production site and/or its type. The problemsposed by these waste packages are therefore linked essentially to the diversity (i) of their chemicalcontent, itself linked to the type of waste and the conditioning matrices used, and (ii) of containershapes and materials. The chemical nature of some packages also makes them liable to produce gases,chiefly hydrogen, by radiolysis. These packages do not generate heat.The various existing and planned technological waste packages can be grouped into nine subsets,taking into account the types of waste, the conditioning processes and the containers.A first subset of these packages comprises 1000-litre concrete containers, manufactured by the CEA,containing low-contamination sludges, debris, earth and sands immobilised in a cement-bitumenmatrix. Following degradation, some of these concrete containers have been installed in non-alloysteel containers (see Figure 3.2.5). These two package shapes are considerably larger than thosedescribed in earlier paragraphs; on average, they weigh around 3.2 metric tons. There are very few ofthese packages (90 in total). As a precaution, with no precise data available, the possibility ofhydrogen production by radiolysis of the matrix water was considered.22The French term EIP, meaning multipurpose storage, refers to the storage facility set up at the Marcoule site which will eventuallycontain all the B waste packages of this site.DOSSIER 2005 ARGILE -ARCHITECTURE AND MANAGEMENT OF A GEOLOGICAL DISPOSAL SYSTEM80/495