The case of HLW-ILW/LL radioactive waste The geological disposal industrial centre (Cigéo) will consist of surface facilities and an underground facility. The surface facilities will primarily be used to accept and check the waste packages. The underground facility, located at a depth of about 500 metres, and comprising nearly 300 km of tunnels, will represent a surface area of about 15 km² where the waste packages will be emplaced by robotic systems in horizontal tunnels called “vaults” excavated in a layer of argilite. * See glossary page 34 The Cigéo project is intended for the deep geological disposal* of high level and intermediate level long-lived waste (HLW/ILW-LL) in order to protect human health and the environment from the very long-term radiological and chemical hazards linked to these wastes. The safety of Cigéo is based notably on the physical properties of this geological layer, which offers sufficient mechanical strength and prevents the migration of radionuclides* to the surface. The choice of deep geological disposal Owing to its depth, its design and its location in impermeable clay rock and a stable geological environment, this type of repository shelters the waste from human activity and natural events on the surface (such as erosion), while isolating the HLW and ILW‑LL waste from human activity over a very long time-scale. This is the preferred solution internationally and was chosen by France via the Bataille Act (1991). These disposal zones will be developed on a modular basis over a period of a century, to allow the gradual construction of the vaults in which the waste packages will be emplaced (see diagram). These packages represent a volume of 85,000 m³. Once all the waste packages are emplaced, Underground laboratory Package reception, inspection and preparation zone Shafts zone Works support zone HLW repository zone Double ramps ILW-LL repository zone THE BURE UNDERGROUND LABORATORY (MEUSE DÉPARTEMENT), situated at a depth of 490 metres, is a unique research tool for the Cigéo project. Its underground drifts allow in-situ study of a layer of clay 160 million years old, along with various concepts and techniques that could be used to construct the Cigéo facility. – 420 m – 550 m – 700 m Credits: Andra/S. Lavoué 22 • Les cahiers de l’ASN • May 2024 THE CHALLENGES FOR TOMORROW
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