Architecture and management of a geological repository - Andra

3 – High Level Long-Lived WasteThe conditioned waste comprises various materials (metals, organic matter, glass, debris, etc.) mixedin the same package. The average weight of the finished packages varies between 1.6 and 2.3 metrictons, depending on the content (compacted or non-compacted, conditioning with overdrums). Giventhe chemical content of the packages, once again potential production of hydrogen by radiolysis of theorganic matter and conditioning matrix water must be considered. These packages do not releaseradiation.The main characteristics of the nine subsets of cemented or compacted technological waste packagesare summarised in Table 3.2.1.Table 3.2.1Summary of the main characteristics of subsets of cemented or compactedtechnological waste packagesPackagesubsetOverall volume of thepackage (m 3 )ContainermaterialEmbedding orimmobilising matrixPresence ofmetallicmaterialsPresence oforganicmatter1 1 Concrete Cement-bitumen None x2 1.2 Fibre-reinforcedconcrete orasbestos cementCement x x3 1.8Concrete or nonalloyCement-bitumen or xx3.2 or 3.8 with overdrumsteelmortar4 0.5 Concrete Cement None x5 1.2 Fibre-reinforced Mortar x xconcrete6 0.18 Stainless steel None x x7 0.428 Stainless steel Cement None x8 0.5 Non-alloy or Cement-bitumen or xxstainless steel cementitious material9 1.22 Non-alloy steel Cement-bitumen orcementitious materialxx3.2.1.4 Cemented or compacted cladding wasteThis type of waste comes from spent fuel reprocessing in the COGEMA plants; it relates to themetallic framework components in the fuel assemblies. This waste is separated from recyclablenuclear materials (uranium, plutonium) and from fission products and minor actinides whenreprocessing commences during fuel shearing and dissolution operations.This waste is commonly known as "hulls and end caps" in pressurised water reactor fuel assemblies.The hulls are the cladding from the fuel rods, recovered in lengths of around three centimetres long,from which the nuclear material has been extracted by being dissolved in acid. The end caps are theparts located at both ends of the fuel assembly.The cladding waste under consideration here has come from reprocessing operations in the COGEMAplants at La Hague. They include (i) waste produced during previous reprocessing operations ofNUGG and PWR fuels, today stored in silos and pits, and (ii) waste from current and futurereprocessing operations of the various types of PWR UOX and MOX fuels, defined in the designscenarios given in Section 3.1.There are several types of materials in cladding waste: magnesium-zirconium and magnesiummanganesealloys for the NUGG fuels; zirconium-tin (zircaloy 4) or zirconium-niobium (M5 alloy)alloys, stainless steels and nickel alloy for the PWR fuels. Following the conditioning hypothesesindicated below, some packages also contain technological waste formed of metal only (non-alloy andstainless steels) or a metallic-organic mixture. The mass of this technological waste represents aroundten per cent of the total mass of conditioned waste per package.DOSSIER 2005 ARGILE -ARCHITECTURE AND MANAGEMENT OF A GEOLOGICAL DISPOSAL SYSTEM85/495