Jura-Südfuss (L/ILW repository)
At the beginning of 2015, Nagra proposed that the geological siting region Jura-Südfuss (SO, AG) should be placed in reserve for Stage 3. ENSI agreed with this proposal at the end of 2016.
The region extends to the west of Olten on both sides of the cantonal boundary between Solothurn und Aargau.
Geological siting region Jura-Südfuss for the L/ILW repository
The Jura-Südfuss siting region lies on both sides of the River Aare in the area east of Olten. From a geological viewpoint, it belongs to the Subjurassic Zone which was influenced by the formation of the Folded Jura and is partly strongly tectonically dissected. The siting region is bounded geologically by regional fault zones (to the north-west, south-west and south) and by the depth of the host rock (to the south-east).
After optimisation, the disposal perimeter comprises 12.6 square kilometres.
The geological siting region Jura-Südfuss for a potential L/ILW repository with the optimised disposal perimeter and the siting area JS-1 for the surface facility.
Canton Solothurn: Däniken, Dulliken, Eppenberg-Wöschnau, Erlinsbach, Gretzenbach, Lostorf, Niedergösgen, Obergösgen, Olten, Schönenwerd, Starrkirch-Wil, Stüsslingen, Trimbach, Winznau
Canton Aargau: Aarau, Buchs, Gränichen, Hirschthal, Holziken, Kölliken, Muhen, Oberentfelden, Suhr, Unterentfelden
Results of the safety-based comparison in Stage 2
In the geological siting region Jura-Südfuss for a L/ILW repository, the effective containment zone (Opalinus Clay and confining units) is of limited thickness. The lower confining units are make effectively no contribution to the barrier function. Compared to the siting regions Zürich Nordost and Jura Ost, the space available in the preferred depth range is small as considerable spatial reserves are required due to the fact that the rock are more strongly tectonically overprinted. Nagra proposes that the Jura-Südfuss siting region be placed in reserve for Stage 3.
Siting area designated for the surface facility
The siting area JS-1 for the surface facility of a potential L/ILW repository in the Jura-Südfuss region is located in the community of Däniken. It was designated by Nagra in September 2013 based on collaboration with the region.
Next steps in the Sectoral Plan process
The proposals submitted by Nagra will be reviewed by the authorities and this will be followed by a public consultation process. At the end of Stage 2 – expected for 2018 – the Federal Council will decide which siting regions will remain in the process. These regions will then be investigated in more detail with 3D seismics and exploratory boreholes in Stage 3. Definitive site selection will be made in Stage 3, with the initiation of the general licence process as required by the Nuclear Energy Act.
In Stage 2, in January 2012, the Federal Office of Energy (SFOE) presented the four discussion proposals made by Nagra for siting areas for the surface facility in the Jura-Südfuss region. These were considered by the region, represented for this purpose by the regional conference, and were then supplemented and evaluated.
Based on the recommendation of the “Surface Facility Working Group”, the regional conference rejected all the proposed areas, but JS-1 will be followed up in the process as the “least bad” option. The regional conference did not make any proposals of its own.
Based on the collaboration with the region and the siting Cantons, Nagra then designated JS-1 as the area for locating the surface facility. The siting area for the surface facility is located in the community of Däniken.
The decision of the Federal Council at the end of Stage 2 is expected for 2018. This represents the definitive decision on which sites will remain in the process and will undergo further investigation in Stage 3. Together with the siting region, the further design of the surface facility and possibilities for optimisation will be concretised in the coming years and will be integrated into a possible general licence application.
|Geographical location of the siting area JS-1 (surface facility for a L/ILW repository).|
Siting area JS-1 for the surface facility
Potential configuration of the components of the surface facility.
|Orthophotograph of the Aare valley between Dulliken and Däniken showing the siting area JS-1. The area lies to the south-west of Däniken (Canton Solothurn, upper right in the photo).|
|Possibility for integrating the surface facility into the surrounding environment (photorealistic representation).|
Next steps in the process
Nagra will carry out an engineering risk analysis for the designated siting area JS-1 (access to the underground facilities), as well as a preliminary investigation for the environmental impact assessment.
In Stage 2 of the Sectoral Plan process, Nagra has to identify at least two geological siting regions per repository type (L/ILW and HLW), including the associated siting area for the surface facility. The proposals are then reviewed by the authorities and this is followed by a public consultation phase.
At the end of Stage 2 – expected for 2017 - the Federal Council will decide which siting regions will remain in the process. Definitive site selection takes place in Stage 3, with the initiation of the general licence procedure as specified in the Nuclear Energy Act.
The Opalinus Clay in the geological siting region Jura-Südfuss qualifies as a host rock for a low- and intermediate-level waste repository.
In the Jura-Südfuss siting region, two potential host rocks for a L/ILW repository – the Opalinus Clay and the Effingen Member – were identified in Stage 1. Nagra carried out a safety-based comparison of these two options in Stage 2. Overall, both host rocks show a good barrier function, but the Effingen Member shows clear disadvantages compared to the Opalinus Clay. The Opalinus Clay therefore qualifies as the priority host rock for the L/ILW repository in the siting region.
The Opalinus Clay is around 175 million years old and reaches a thickness of around 90 metres in the siting region. It makes the main contribution to the barrier function of the overall system. There are uncertainties regarding the upper confining units (Passwang Formation und Lower Acuminata strata) and these have to be taken into account in the evaluation. However, they do not have any influence on the selection of the siting regions. The lower confining units include layers with a partly increased hydraulic conductivity and make effectively no contribution to the barrier function. Compared to the siting regions Zürich Nordost und Jura Ost the space available is smaller as considerable spatial reserves are required due to the fact that the rocks have undergone strong tectonic overprinting.
After optimisation, the disposal perimeter for a L/ILW repository in Jura-Südfuss comprises an area of 12.6 square kilometres (simplified presentation according to NTB 14-01).
Geological rock profile from west to east through the siting region Jura-Südfuss. The grey arrow marks the Opalinus Clay.
Vertical geological profile showing the rock strata occurring in the Jura-Südfuss region.
Questions about the siting region
|2016 (22 March)||The SFOE publishes the Federal Office for the Environment’s review of the EIA preliminary investigations for the Jura Ost and Zürich Nordost regions.|
|2015 (30 Jan.)||The SFOE announces Nagra’s siting proposals. The geological siting regions Zürich Nordost and Jura Ost will undergo further investigation in Stage 3. They are suitable for a HLW, L/ILW or combined repository. The other siting regions will be placed in reserve. The proposals (safety-based comparisons, EIA preliminary investigations...) will be reviewed by the authorities, followed by a public consultation process. The Federal Council decision on Stage 2 is expected for 2018.|
|2014 (24 May)||Nagra presents the planning studies for the designated siting areas NL-2 and NL-6 for the surface facility at a full meeting of the regional conference for Nördlich Lägern.|
|2014 (15 May)||Nagra presents the planning study for the designated siting area ZNO-6b for the surface facility at a full meeting of the regional conference for Zürich Nordost.|
|2013 (4 Dec.)||Nagra presents the planning study for the designated siting area SR-4 for the surface facility at a full meeting of the regional conference for Südranden.|
|2013 (Sept.)||Nagra presents the planning study for the designated siting area JO-3+ for the surface facility at a full meeting of the regional conference for Jura Ost on 26th September. The planning studies for the designated siting areas in the regions Jura-Südfuss and Wellenberg are also presented in September. The planning studies for the other three siting regions will follow in the coming months.|
|2012 (20 Jan.)||Nagra announces its proposals for potential siting areas for the surface facility at a media conference held by the Swiss Federal Office of Energy (SFOE). These proposals serve as the basis for discussions within the framework of regional participation.|
|2011 (30 Nov.)||The Federal Council decides to include the geological siting region Jura Ost in the continuing Sectoral Plan process. Stage 1 of the process is complete and Stage 2 has been initiated.|
|2010 (1 Sept.)||Start of the public consultation phase on Stage 1 of the site selection process for deep geological repositories.|
|2010 (26 Feb.)||The Swiss Federal Nuclear Safety Inspectorate (ENSI) approves Nagra's proposed geological siting regions based on a review of safety and engineering feasibility criteria.|
|2009 (10 Dec.)||Announcement of the provisional planning perimeter by the Swiss Federal Office of Energy (SFOE).|
|2008 (11 Dec.)||Together with representatives from ENSI and Nagra, the SFOE provides information on the proposals for geological siting regions at an event in Oberbözberg.|
|2008 (4 Dec.)||Together with representatives from ENSI and Nagra, the SFOE provides information on the proposals for geological siting regions at an event in Niedergösgen.|
|2008 (6 Nov.)||Announcement by the SFOE of the proposed siting regions for deep geological repositories.|
|2008 (2 April)||The Federal Council approves the conceptual part of the Sectoral Plan for Deep Geological Repositories.|
|1993||Completion of the site investigations for low- and intermediate-level waste disposal, comparative assessment of the results for the four potential sites, proposal of the Wellenberg site.|
|1991 – 1992||Regional seismic investigations between the river Aare and Lake Constance (2D seismics).|
|1988||Recognition by the Federal Council of the feasibility and safety of disposing of low- and intermediate-level waste in Switzerland.|
|1985||Submission of Project Gewähr to the federal authorities (demonstration of the feasibility and safety of disposing of all types of radioactive waste in Switzerland).|
|1983 – 1984||Riniken (AG) deep borehole.|
|1982 – 1984||Regional seismic investigations in the area Olten - Schaffhausen.|