Tome Architecture and management of a geological repository - Andra

2 – High-Level and Long-Lived wasteThis chapter describes the primary HLLL waste packages that are considered for the 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 fuel consistent with current industrial practice,reprocessing of URE and MOX fuel, possible increase in the heat rating of vitrified C waste and theexploratory hypothesis of direct disposal of UOX, URE and MOX fuel.This chapter then presents the two categories of waste that fall into the framework of the30 December 1991 Act. It also provides an inventory model [3] which forms the basis for constructingall the design and dimensioning studies for the repository. The model brings together all the variouswaste families by defining waste “reference packages” (or package types) covering each a more or lessimportant range, varying in extent, of primary waste packages. The notion of waste reference packageis an essential element structuring the technical options considered in response to the diversity ofprimary waste. It is therefore a key to reading the following chapters. The inventory model stipulateswhich hypotheses are adopted for the number of primary packages to be incorporated for each studyscenario.2.1 The production of HLLL waste, study scenariosThe activity sectors producing the greatest volume of HLLL waste come within the nuclear powerindustry (EDF electricity-generating reactors, COGEMA fuel reprocessing plants, MELOX plantproducing MOX fuel) 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 “PWR” pressurised water reactors (58 of these are currentlyoperated) are reprocessed in the La Hague plants, except for URE and MOX fuels, prepared fromreprocessed uranium and plutonium respectively, which at present are stored in pools [4].Reprocessing operations produce various types of waste, either directly resulting from spent fuel(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 equipments) or radioactive effluent treatment (sludge). Currently, waste is conditioned in-line inthe 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 the so-called “UMo”solutions currently stored at La Hague, it should be noted that all fission product solutions, as well aseffluent sludges 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 mainly concerns neutronic poison and control rod assemblies and, to a lesser extent, waste suchas source clusters and metal parts (thimbles and pins for example). All waste currently produced isstored in pools close to the reactors.Dossier 2005 Granite - ARCHITECTURE AND MANAGEMENT OF A GEOLOGICAL REPOSITORY20/228