Tome Architecture and management of a geological repository - Andra
Tome Architecture and management of a geological repository - Andra
Tome Architecture and management of a geological repository - Andra
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5 – B waste <strong>repository</strong> zoneFigure 5.1.4 Stainless steel drum used as over-drum 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 <strong>repository</strong>.On average, the weight <strong>of</strong> conditioned waste per package is 220 to 240 kilograms, including roughly 90kilograms <strong>of</strong> dry extract <strong>and</strong> 130 kilograms <strong>of</strong> bitumen. The average weight <strong>of</strong> the finished packages is 240kilograms for STE3/STE2 <strong>and</strong> STEL packages <strong>and</strong> 330 kilograms for STEL packages with over-drum..5.1.3 Cemented or compacted technological wasteA third group <strong>of</strong> waste (reference package B3) is technological waste resulting from the operation <strong>and</strong>maintenance <strong>of</strong> nuclear facilities by COGEMA <strong>and</strong> the CEA. This consists mainly <strong>of</strong> various kinds <strong>of</strong>solid waste (various metals, organic materials), but also includes filtration sludge <strong>and</strong> evaporationconcentrates. This group also includes various waste produced at Marcoule such as graphite, ionexchangerresins <strong>and</strong> zeolites. The radiological activity <strong>of</strong> waste, especially <strong>of</strong> technological waste, isusually due surface contamination <strong>of</strong> the waste by fission products <strong>and</strong>/or activation products <strong>and</strong>/oractinides.The conditioning process for this waste depends on its production site <strong>and</strong>/or its type. The problemsposed by these waste packages are therefore linked essentially to the diversity (i) <strong>of</strong> their chemicalcontent, itself linked to the type <strong>of</strong> waste <strong>and</strong> the conditioning matrices used, <strong>and</strong> (ii) <strong>of</strong> containershapes <strong>and</strong> materials. The chemical nature <strong>of</strong> some packages also makes them liable to produce gases,chiefly hydrogen, by radiolysis. These packages do not generate heat.The various existing <strong>and</strong> planned technological waste packages can be grouped into nine subsets,taking into account the types <strong>of</strong> waste, the conditioning processes <strong>and</strong> the containers.A first subset <strong>of</strong> these packages comprises 1000-litre concrete containers, manufactured by the CEA,containing low-contamination sludge, debris, earth <strong>and</strong> s<strong>and</strong>s immobilised in a cement-bitumenmatrix. Following degradation, some <strong>of</strong> these concrete containers have been installed in non-alloysteel containers (see Figure 5.1.5).These two package shapes are considerably larger than those described in earlier paragraphs; onaverage, they weigh around 3.2 metric tons. There are very few <strong>of</strong> these packages (90 in total). As aprecaution, with no precise data available, the possibility <strong>of</strong> hydrogen production by radiolysis <strong>of</strong> thematrix water was considered.Dossier 2005 Granite - ARCHITECTURE AND MANAGEMENT OF A GEOLOGICAL REPOSITORY100/228
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