Südranden (L/ILW repository)
Nagra proposes that the geological siting region Südranden (SH) be placed in reserve for Stage 3.
The siting region located near the Wannenberg – Lauferberg range of hills in the Canton Schaffhausen is one of the six potential siting regions for a deep geological repository confirmed by the Federal Council.
The geological siting region
The siting region is located in the Tabular Jura near the Wannenberg – Lauferberg range of hills. It is bounded geographically by the Klettgau channel (to the north) and the national border (to the south) and geologically by the Neuhausen Fault and the depth of the host rock (to the north-west). The host rock has a restricted lateral extent and the rock layers show quiet bedding.
Following optimisation, the disposal perimeter comprises 3.7 square kilometres.
|The Südranden geological siting region for a potential repository for L/ILW with the optimised disposal perimeter and the SR-4 siting area for the surface facility.|
Canton Schaffhausen: Beringen, Neuhausen am Rheinfall, Neunkirch, Wilchingen
Results of the safety-based comparison in Stage 2
In the Südranden siting region for a L/ILW repository, the host rock is located at a relatively shallow depth and has only very limited protection from erosion. As a result of the small overburden above the upper confining units, the effective containment rock zone is restricted compared to other siting regions. The formation of erosion channels that could have an influence on the long-term stability of the geological barrier is also possible. The limited suitability of the host rock depth and the centrally located Neuhauserwald bedrock channel offer only limited possibilities for optimising the disposal perimeter and, as a result, the availability of space is only just suitable.
Nagra therefore proposes that the Südranden geological siting region be placed in reserve for Stage 3.
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 procedure as required by the Nuclear Energy Act.
In Stage 2, in January 2012, the Swiss Federal Office of Energy (SFOE) presented the three proposals made by Nagra for the siting area for the surface facility of the deep geological repository.
These proposals were discussed, supplemented and evaluated by the region, represented by the regional conference. Based on the results of the discussions, the regional conference asked Nagra to prepare the additional proposals SR-4 and SR-5.
On the recommendation of the “Surface Facility Working Group”, the regional conference then rejected all the siting proposals. According to the regional conference, siting area SR-4 was the “least unsuitable” and the conference attached various conditions to its designation.
Based on the collaboration within the framework of regional participation, Nagra then designated SR-4 as the area for locating the surface facility. The siting area for the surface facility is located in the community of Neuhausen am Rheinfall.
The decision of the Federal Council at the end of Stage 2 is expected for 2018. This represents the definitive decision as to which siting regions will remain in the process and will be further investigated in Stage 3. Collaboration with the remaining siting regions will continue in the coming years on the concrete design of the surface facility and the possibilities for optimisation; the results will be taken over into a possible general licence application.
|Geographical location of the siting area SR-4 (surface facility for a low- and intermediate-level waste repository).|
Siting area SR-4 for the surface facility
|Potential configuration of the components of the surface facility.|
|Orthophotograph of the area between Beringen (above left) and Neuhausen am Rheinfall (below right) showing the siting area SR-4.|
|Possibility for integrating the surface facility into its surroundings (photorealistic representation).|
In the siting region Südranden, the Opalinus Clay has been examined as a host rock for disposal of low- and intermediate level waste.
The Opalinus Clay is around 175 million years old and reaches a thickness of around 105 metres in the siting region. It makes the main contribution to the barrier effect of the overall system. The lower confining units (Clay-rich Lias) also contribute to the barrier function. The 'Brauner Dogger' is not considered to be a confining unit because it could be adversely affected by decompaction effects.
The long-term stability of the geological barrier is of only limited suitability and the shallow location of the host rock provides only limited protection from erosion. The available space underground in the siting region is only just sufficient as the region is divided by a bedrock channel (the Neuhauserwald channel identified by seismic investigations in 2011/2012).
|After optimisation, the disposal perimeter for a L/ILW repository in Südranden comprises an area of 3.7 square kilometres (simplified presentation according to NTB 14-01).|
Geological profile from west-south-west to east-north-east through the Südranden siting region. The grey arrow marks the Opalinus Clay.
|Geological rock profile showing the rock strata occurring in the Südranden 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 2017.|
|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.)||At a media conference held by the Swiss Federal Office of Energy (SFOE), Nagra announces its proposals for potential siting areas for the surface facility. These will serve as the basis for discussions within the framework of regional participation.|
|2011 (30 Nov.)||The Federal Council decides to include the siting region Jura Ost in the further Sectoral Plan process. Stage 1 of the process is completed and Stage 2 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 siting regions following a review of safety and engineering feasibility aspects.|
|2009 (10 Dec.)||Announcement of the provisional planning perimeter by the Swiss Federal Office of Energy (SFOE).|
|2008 (18 Nov.)||Together with representatives of ENSI and Nagra, the SFOE provides information on the proposals for geological siting regions at an event in Neuhausen am Rheinfall.|
|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 sites, proposal of the Wellenberg site.|
|1991 - 1992||Regional seismic investigations between the river Aare and Lake Constance (2D seismics).|
|1988 - 1989||Siblingen deep borehole.|
|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).|
|1982 - 1984||Regional seismic investigations in the area Olten - Schaffhausen.|