Can the rock laboratory be converted to deep geological disposal?

No. That is not possible. The rock laboratory is used only for research purposes. There can be no question of the disposal of radioactive waste here. That is part of the contractual arrangement with the Canton of Jura.


What is researched in the rock laboratory?

Research is separated into individual experiments, differentiated according to the following types: Development of methodology, e.g. test performance and related analyses; Characterisation of Opalinus Clay, e.g. understanding the chemical and physical processes in the Opalinus Clay at the laboratory and investigating the relevant properties and Parameters; Demonstration experiments. Here, tests on a 1:1 scale can be carried out over a long period. Generally, the experiments in the rock laboratory provide a significant body of knowledge about the feasibility and safety of deep geological disposal.


Why clay for a deep geological disposal facility?

Argillaceous rocks are suitable as a geological barrier for the long-term encapsulation of radioactive waste. The three most important characteristics are: Retention of radionuclides at the clay mineral surfaces, very low permeability (no transfer of radionuclides by flowing water), and the ability to self-sealing of cracks and fissures by swelling.

Properties of Opalinus clay

Is it possible to visit the rock laboratory?

Yes! Guided tours of the Mont Terri rock laboratory are organised throughout the year for groups of visitors. More information is available here: Tel. +41 32 461 40 53 /

Welcome to the visitors center

The Mont Terri project

The picture shows the entrance to the rock laboratory with the flags of all patners at the door.

The Mont Terri Project is an international research project for the hydrogeological, geochemical and geotechnical characterisation of a clay formation (Opalinus Clay).



Starting May 11, the scientific research work in the rock lab has resumed in a restricted manner. The Visitor Centre is again opened starting June 8. We thank you for your support during the last three months.

ETH Zurich and the Federal Office for the Safety of Nuclear Waste Management in Germany are new research partners in the Mont Terri project

Since 1 July 2019, ETH Zurich and the German Federal Office for the Safety of Nuclear Waste Management have been new partners in the Mont Terri research project. This means that 21 organisations from nine nations are now conducting research in the Mont Terri Rock Laboratory near St-Ursanne under the direction of swisstopo. While international research in the Opalinus Clay has so far concentrated on the safe underground storage of low-, medium- and high-level radioactive waste, ETH Zurich is giving new impetus to the still young field of research on CO2 storage.


Three ETH Zurich departments are represented:

  • The Department of Earth Sciences (Engineering Geology, Swiss Seismological Service)
  • EAWAG (Water Resources and Drinking Water Division)
  • The Paul Scherrer Institute (Laboratory for Waste Management LES)



Start of excavation for Gallery 2018 on March 12

Start of excavation works for Gallery 2018
Responsibles from Confederation, Canton Jura and Underground Rock Laboratory (URL) during the start of the extension work

The expansion of the Mont Terri rock laboratory in St-Ursanne has officially started. In just under two years, the research facility will have an additional 600 metres of tunnels and niches for experiments.

More informations

Start of excavation for Gallery 2018

Impressions from the rock laboratory

News: Extension of the Mont Terri rock laboratory

News: Extension of the Mont Terri rock laboratory

From 2018 to 2019 the Mont Terri rock laboratory was extended. Here, you find more links and information about it.

Extension 2018

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