The HADES Underground Research Facility. RWMC FY2005 Consultation 2 Task 2 Special Report 2.1

The HADES URF is the main research facility in Belgium for R&D on the geological disposal of high-level radioactive waste. HADES is located in the Boom Clay layer at a depth of 225 m. The Boom Clay is a plastic clay of Rupelian age (~35MY) and has a thickness of about 100 m in the area of HADES. The first construction phase started in 1980 and since then HADES has been expanded several times. Excavation techniques evolved over time and in recent years the economical and technical feasibility of high-performance industrial excavation techniques for shafts and horizontal drifts were demonstrated. The primary purpose of HADES is to enable in-situ experiments on geomechanics, corrosion, thermal behaviour, migration, etc… For over 25 years, experiments in HADES have led to important advances in all these domains. At the start, experiments usually focussed on one specific aspect but as knowledge was gained, more complicated and multidisciplinary experiments were installed examining e.g. the combined effect of temperature, radiation and in-situ chemistry on relevant processes such as corrosion. Currently, a large-scale (2.5m diameter gallery) and long-term (~10 years) heater experiment is being prepared: the so-called PRACLAY experiment.