Architecture and management of a geological repository - Andra

3 – High Level Long-Lived WasteThis chapter describes the primary waste packages that are considered for the geological repositoryfeasibility study. It draws particular attention to their diversity. It is based on the results of the workcarried out jointly between Andra and the producers concerning (i) surveying, and (ii) collecting andstructuring the knowledge.Firstly it sets out the waste production scenarios underpinning the inventory considered. The survey ofexisting waste is based on knowledge of past and present processes, production reports for eachfacility, identification of storage sites and control of their contents. In considering future waste,hypotheses have been formulated concerning the continuation of production by the various facilities.For waste from nuclear power plants, several scenarios have been selected to cover the variouspossible situations: ongoing reprocessing of spent UOX fuels consistent with current industrialpractice, reprocessing of URE and MOX fuels, possible increase in the heat rating of vitrified C wasteand the exploratory hypothesis of direct disposal of UOX, URE and MOX fuels.This chapter then sets out the primary waste package characteristics for each existing or plannedfamily surveyed, on the basis of the relevant knowledge collected by the producers.It also provides an inventory model [3] which forms the basis for constructing all the design anddimensioning studies for the repository. The model brings together all the various waste families bydefining "waste packages types" covering each a more or less important range, varying in extent, ofprimary waste packages. The notion of waste package types is an essential element structuring thetechnical options considered in response to the diversity of primary waste. It is therefore a key toreading the following chapters.Finally, the chapter sets out the hypotheses concerning waste disposal volumes over time for variousscenarios.3.1 Waste production: the study scenariosThe activity sectors producing the greatest volume of waste studied come within the nuclear powerindustry (EDF electricity-generating reactors, COGEMA fuel reprocessing plants, MELOX plantproducing MOX fuels) or research and national defence activities (CEA centres).The study must also consider waste produced upstream of the cycle, during uranium ore processingoperations, and end-of-life radioactive objects from various industrial and medical activities.Currently, spent fuels removed from pressurised water reactors (58 of these are currently operated) arereprocessed in the La Hague plants, except for URE and MOX fuels, prepared from reprocesseduranium and plutonium respectively, which at present are stored in pools [39].Reprocessing operations produce various types of waste, either directly resulting from spent fuels(fission product solutions and minor actinides, fuel assembly cladding waste), or linked to the use offacilities for maintenance operations (technological waste resulting from replacement of parts andother equipment) or radioactive effluent treatment (sludge). Currently, wastes are conditioned in-linein the UP2-800 and UP3 plants at La Hague. In previous-generation plants (UP2-400 at La Hague andUP1 at Marcoule, now shut down), where fuels from various reactor generations were reprocessed,especially the first-generation NUGG (Natural Uranium-Graphite-Gas), part of the waste was stored inunconditioned form in specific facilities. However, with the exception of Umo solutions currentlystored at La Hague (see Section 3.2.2.1), it should be noted that all fission product solutions, as well aseffluent sludge at Marcoule, have been conditioned.In addition, the operation of electricity-generating nuclear reactors requires systems for starting up andcontrolling the reactors. After a certain time these are replaced and become waste. This mainlyconcerns neutronic poison and control rod assemblies and, to a lesser extent, waste such as sourceclusters and metal parts (thimbles and pins for example). All waste currently produced is stored inpools close to the reactors.DOSSIER 2005 ARGILE -ARCHITECTURE AND MANAGEMENT OF A GEOLOGICAL DISPOSAL SYSTEM74/495