Présentations Colloques

Oral Presentation
7.04
Session 7.04: Groundwater and man-made underground works
Benabderrahmane Abdelhakim
Hydrogeological impact of the access ramps and shafts of the French Cigeo deep radioactive waste disposal on the above aquifers
Andra, the French national radioactive waste management agency is responsible for the long-term management of all radioactive waste produced in France. Its main mission is to find, implement and ensure safe management solutions for French radioactive waste, in order to protect present and future generations from the risk of these wastes. For Cigéo project (industrial center for deep geological disposal, applied to high-level waste and long-lived wastes), Andra has to assess impact and safety, from operating phase to long-term period, based on a sound scientific knowledge deduced from in situ experiments in URL, numerical simulation, technological demonstrators, …**In the scope of assessing shafts and ramps hydraulic impact, Andra has performed numerical simulations in order to quantify hydraulic discharges and flow coming into the structures, and thus to provide useful information to the design process. The objective of this paper is to describe the entire work, from data acquisition to simulation results, including phenomenological and numerical model development, taking into account both a fine description of hydrogeological layers and the digging schedule. **Description of the results will be focused on expansion of hydraulic drawdown in the multi-layer aquifer system, and its consequences on both (i) aquifer monitoring network (ii) ramp and shafts design (sealing of shafts parts, sizing of pumping system, etc..).**
France