Dossier 2005 Argile-Architecture and Management of a Geological Repository

The Law of 30 December 1991 Loi n¯ 91-1381 du 30 dÇcembre 1991 relative aux recherches sur la gestion des dÇchets radioactifs. conferred on Andra the task of assessing the feasibility of a high-level, long-lived waste (HLLL waste) repository in a deep geological formation. This volume of the Dossier 2005 Argile reports on the results of the study from the standpoint of the architecture and management of such a repository. It is based on the characteristics of the clay formation studied in an underground research laboratory located in the Meuse and Haute-Marne departments. The feasability study sought to assess if it would be possible to build a repository which could be operated and managed in a reversible manner, closed and monitored and then evolve without any further human invention. It covers the entire inventory of existing French HLLL waste (classified as B or C) or waste which is to be produced in the short and medium term future (as well as, on an exploratory basis, spent fuel which has not necessarily been reprocessed). It aims to ensure that the safety of staff and public, and environmental protection, are not compromised at any time. To assess feasibility, Andra has selected a potential repository architecture that meets expectations and is industrially realistic. The repository design is based on available knowledge and technology. The architecture studied does not in any way freeze the definition of a potential repository. The technical options set out in this document, chosen as being as simple and robust as possible, show that solutions are conceivable. They should not be regarded as optimized solutions, either in technical/economic terms or from the safety standpoint. They may be developed further if action is taken on the project after 2006. This architecture was also the basis used to analyse repository safety, particularly its behaviour and evolution at different time scales. Two other volumes of the Dossier 2005 Argile address the phenomenological evolution of a repository and its safety assessment (Figure 1.1.1). All three volumes are based on reference knowledge documents and a number of thematic technical documents. The reference knowledge documents concern the Meuse/Haute-Marne site, waste packages (description and inventory model), the repository's constituent materials, waste package behaviour (release model) and radionuclide behaviour. The thematic technical documents particularly relevant to this volume concern the specifications for and design of the main repository components (waste packages and cells) and conceptual modelling of phenomena to be taken into account in designing repository reversibility (e.g. thermal load).