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The lab in the underworld

HADES is the underground lab at the SCK CEN site in Mol. Here, scientists have been conducting research into geological disposal of long-lived and/or high-level waste for 40 years, 225 metres deep in the Boom Clay.

The underground laboratory HADES is now operated by EURIDICE, an economic partnership between SCK CEN and NIRAS/ONDRAF.

HADES 40 (2)

Research on Boom clay interacting with radioactive substances

To test the geological disposal in layers of clay in Boom under real conditions, SCK CEN started in 1980 with the construction of a laboratory at 225 metres below ground level. The underground laboratory was given the apt name HADES, god of the underworld. Here, scientists perform research into the mechanical, chemical and microbiological characteristics of clay and the interaction between the radioactive waste and the materials in which the waste will be packed. How slowly do the radioactive substances spread in clay? How soon are the packaging materials of the radioactive waste affected? How can we build tunnels and side tunnels? The research results, computer models and simulations are promising. The radioactivity that after thousands of years would be released from the clay layer in strongly diluted concentrations, has no impact on humans or the environment.

💡 Want to know more about geological disposal? Read more here.


Purpose of EURIDICE in HADES

EURIDICE’s research activities include conducting large-scale tests, technical demonstrations and experiments designed to:

  • demonstrate the technical feasibility of building an underground disposal infrastructure in poorly indurated clay, comprising access shafts, main gallery and disposal galleries

  • study the excavation-damaged zone in the clay around the galleries and its potential impact on the performance of the disposal system
  • study the thermal impact of heat-emitting high-level waste on the behaviour of the clay

More on


The PRACLAY experiment: one of many HADES experiments

High-level waste generates heat and when placed in a repository it will cause the clay around the disposal galleries to heat up temporarily. The PRACLAY experiment is a large-scale experiment designed to study the impact of this heat on the deep clay layer. It will also look at how excavation affects the behaviour of the clay. 

More info on the studies

Take a look at HADES

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