Jura Ost

The Federal Council decided on 21st November 2018 that the Jura Ost siting region (Canton Aargau) should undergo further investigation in Stage 3.

The siting region is located in the precursory folding zone of the Aargau Jura Mountains and was confirmed by the Federal Council in Stage 2 as one of the three potential siting regions for a deep geological repository.

Geological siting region Jura Ost

In Jura Ost, the siting regions for the L/ILW repository and the HLW repository are located in the precursory folding zone of the Aargau Jura Mountains. The quiet bedding of the strata that dip slightly towards the south-east is highly reminiscent of the relatively undisturbed Tabular Jura. The L/ILW siting region is bounded geologically by the Jura Main Thrust to the south, a regional fault to the north and the depth of the host rock in the east and west. The siting region for the HLW repository is bounded geologically by the Jura Main Thrust to the south and by the depth of the host rock in the east, north and west.

The siting regions for the L/ILW and HLW repositories or a combined repository in Jura Ost showing the main underground connection area, the potential disposal zones for HLW and L/ILW, the perimeter for the auxiliary access facilities and the siting area JO-3+ for the surface facility.

Siting communities in the region

L/ILW siting region, Canton Aargau: Bözen, Brugg, Effingen, Elfingen, Gallenkirch, Gansingen, Herznach, Hornussen, Kaisten, Laufenburg, Linn, Mönthal, Oberbözberg, Remigen, Riniken, Ueken, Unterbözberg, Villigen, Villnachern, Zeihen

HLW siting region, Canton Aargau: Brugg, Effingen, Elfingen, Gallenkirch, Linn, Mönthal, Oberbözberg, Remigen, Riniken, Unterbözberg, Villnachern, Zeihen

Next steps in the site selection process

Stage 3 is currently underway. More information is available on the page "Site selection".

Starting-point for concretising the surface infrastructure

At the end of Stage 2, the Federal Council designated an area for the surface facility in the siting region (JO-3+) and also indicated that potential synergies with the centralised interim storage facility Zwilag in Würenlingen should be investigated. As the surface facility is located outside the potential disposal zones, the main access to the repository would be via a tunnel. This would be used for the construction and operation of the repository and later for waste transport. The tunnel would start from the Schmidberg clay-pit, which is located in the vicinity of the JO-3+ siting area. The main underground connection area would be in the vicinity of Riniken at the eastern edge of the potential disposal zones. There would also be a ventilation shaft within the perimeter for the auxiliary access facilities. Based on this, Nagra has developed two proposals for the collaboration with the regions.

The concrete proposals can be found in the factsheet on Jura Ost (in German).

The Opalinus Clay is the host rock for the disposal of radioactive waste in the Jura Ost siting region.

The Opalinus Clay is around 173 million years old and is suitable as a host rock for both a HLW and a L/ILW repository. In the L/ILW and HLW siting regions, it reaches a thickness of around 110 metres and provides the main contribution to the barrier function of the overall system. In the Jura Ost siting region, there are uncertainties that have to be taken into consideration in the evaluation of the upper confining units (Passwang Formation and Lower Acuminata Beds), but these have no influence on the selection of the siting regions. The lower confining units (clay-rich Lias) have a comparable barrier function to that in the east facies area. The long-term stability is assured by the geological situation. Despite the limitations relating to the depth of the host rock, the L/ILW and HLW siting regions are suitable in terms of the space available in the preferred depth range.

Geological profile from west-south-west to east-north-east through the Jura Ost siting region. The grey arrow marks the Opalinus Clay.


Geological profile showing the rock strata occurring in the Jura Ost region.

In the third stage of the site selection process, the three siting regions remaining in the process are investigated in greater detail and then compared with one another. The exploration programme includes Quaternary investigations and deep boreholes. The latter will complete the overall geological picture of the siting region. The focus of the geoscientific investigations in the deep boreholes is on the depth, thickness, permeability and composition of the Opalinus Clay host rock in which the repository will be constructed. The properties of the confining rock units above and below the Opalinus Clay are also of particular interest.

Questions about the siting region

Questions on the Sectoral Plan process: Swiss Federal Office of Energy (SFOE)



Questions on safety: Swiss Federal Nuclear Safety Inspectorate (ENSI)


We use cookies to improve your experience on our website. By browsing this website, you consent to our use of cookies. For more information on our “Legal Conditions and Privacy Policy”, click here. Find out more about legal and data protection here
I accept