Nördlich Lägern (L/ILW repository)
At the beginning of 2015, Nagra proposed that the geological siting region Nördlich Lägern (ZH, AG) should be placed in reserve for Stage 3. ENSI recommended at the end of 2016 that Nördlich Lägern should also be investigated further.
The region to the north-west of Bülach is one of the six potential siting regions for a deep geological repository confirmed by the Federal Council.
Geological siting region Nördlich Lägern for the L/ILW repository
The siting region is located in the deformed Tabular Jura and is defined geographically by the national borders along the Rhine river and geologically by a fault zone (to the north and south) and by the depth of the host rock (to the south). The rocks within the disposal perimeter show less quiet bedding conditions than in the Zürich Nordost siting region. The Opalinus Clay qualifies as the priority host rock.
After optimisation, the disposal perimeter comprises 1.2 square kilometres.
|The geological siting region Nördlich Lägern for a potential L/ILW repository with the optimised disposal perimeter and the siting areas NL-2 and NL-6 for the surface facility.|
Canton Zürich: Bachs, Bülach, Eglisau, Glattfelden, Hochfelden, Neerach, Niederweningen, Oberweningen, Schleinikon, Schöfflisdorf, Stadel, Weiach
Canton Aargau: Fisibach, Schneisingen, Siglistorf
Results of the safety-based comparison in Stage 2
The geological siting region Nördlich Lägern for a L/ILW repository has insufficient space in the preferred depth range and there is no possibility to construct the repository at the optimum depth from an engineering perspective. More space is available at greater depth, but the engineering challenges would be significant and would probably lead to considerable impairment of the geological barrier.
Nagra proposes that the Nördlich Lägern siting region be placed in reserve for Stage 3.
Siting area designated for the surface facility
The siting area NL-2 for the surface facility of a potential L/ILW repository in the Nördlich Lägern siting region lies in the community of Weiach, to the east of the village. The siting area NL-6 lies in the community of Stadel. Based on collaboration with the region, the two siting areas were designated by Nagra in May 2014.
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.
Operation of a deep geological repository requires a surface facility.
In Stage 2, in January 2012, the Swiss Federal Office of Energy (SFOE) presented the four discussion proposals made by Nagra for the siting area for the surface facility of the deep geological repository. These proposals were discussed, added to and evaluated by the region, represented by the regional conference.
Nagra then prepared four additional siting proposals and a variant on an existing proposal. A further proposal was also developed at the request of Canton Zürich. The regional conference thus evaluated a total of ten proposals.
Based on cooperation within the framework of regional participation, Nagra designated the siting areas NL-2 and NL-6 as the potential areas for locating the surface facility of a L/ILW repository. The siting area NL-2 lies in the community of Weiach and the siting area NL-6 lies in the community of Stadel.
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 areas NL-2 and NL-6 (surface facility for a L/ILW repository).|
Siting area NL-2 for the surface facility
|Potential configuration of the components of the surface facility for a L/ILW repository (NL-2).|
|Orthophotograph of the NL-2 siting area in the community of Weiach. The area in red shows the space required for the surface facility of a L/ILW repository.|
|Possibility for integrating the NL-2 surface facility into the surrounding landscape (photorealistic view) for the example of the L/ILW repository, looking north. The buildings in the background are the gravel and concrete plant.|
Siting area NL-6 for the surface facility
|Potential configuration of the components of the surface facility for a L/ILW repository (NL-6).|
|Orthophotograph of the NL-6 siting area in the community of Stadel. The area in red shows the space required for the surface facility of a L/ILW repository.|
|Possibility for integrating the NL-6 surface facility into the surrounding landscape (photorealistic view) for the example of the L/ILW repository, looking west.|
In the siting region Nördlich Lägern, the Opalinus Clay qualifies as a host rock for disposal of low- and intermediate-level waste.
In Stage 1, two potential host rocks were identified for a L/ILW repository, namely the Opalinus Clay and the 'Brauner Dogger'. Nagra carried out a safety-based comparison of these two options in Stage 2, with the result that, overall, both host rocks show a good barrier function. However, the ‚Brauner Dogger’ 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 Nördlich Lägern siting region.
The Opalinus Clay is around 175 million years old and is around 110 metres thick in the siting region. It makes the main contribution to the barrier function of the overall system. The confining units above and below the Opalinus Clay ('Brauner Dogger' clay sequence, the Effingen Member and the Clay-rich Lias) also make a significant contribution to the barrier function. For the upper confining units, there are uncertainties that have to be considered in the evaluation. However, these have no influence on the selection of the siting regions.
The space available in the siting region in the preferred (from a technical-scientific viewpoint) depth range is unsuitable. More space is available at greater depth, but it would be difficult from an engineering viewpoint to construct a repository. During construction, the unfavourable depth could lead to significant impairment of the geological barrier.
|After optimisation, the disposal perimeter for a deep geological repository for L/ILW in the Nördlich Lägern siting region comprises 1.2 square kilometres.|
|Geological profile from north-north-east to south-south-west through the North of Lägeren siting region. The grey arrow marks the Opalinus Clay.|
|Geological rock profile showing the rock strata occurring in the Nördlich Lägern 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 Nördlich Lägern in the further 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 (20 Nov.)||Together with representatives of ENSI and Nagra, the SFOE provides information on the proposals for geological siting regions at an event in Glattfelden.|
|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||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.|
|1982 – 1983||Weiach (ZH) deep borehole.|