Zürich Nordost (L/ILW repository)
At the beginning of 2015, Nagra proposed the geological siting region Zürich Nordost (ZH, TG) for further investigation in Stage 3. ENSI also recommended at the end of 2016 that Zürich Nordost should be investigated further.
The region in the north of Canton Zürich is one of the six potential siting regions for a deep geological repository confirmed by the Federal Council.
Geological siting region Zürich Nordost for the L/ILW repository
The siting region is located in the eastern Tabular Jura and is bounded geographically by the national borders along the Rhine river (to the west and north-west) and geologically by the Neuhausen Fault (to the north-east), as well as by the maximum depth of the host rock (to the south-east). The Opalinus Clay host rock has a large lateral extent and the rock layers show quiet bedding.
After optimisation, the disposal perimeter comprises 6.5 square kilometres.
|The geological siting region Zürich Nordost for a potential L/ILW repository with the optimised disposal perimeter and the siting area ZNO-6b for the surface facility.|
Canton Zürich: Benken, Dachsen, Flaach, Flurlingen, Kleinandelfingen, Laufen-Uhwiesen, Marthalen, Ossingen, Rheinau, Trüllikon, Truttikon
Canton Thurgau: Schlatt
Results of the safety-based comparison in Stage 2
The geological siting region Zürich Nordost for a L/ILW repository has a large underground spatial extent in the preferred depth range and offers a wide range of possibilities for optimum definition of the disposal perimeter. The disposal perimeter is well balanced in terms of depth. The effective containment zone (Opalinus Clay combined with thick confining units) shows very good barrier properties. The geological situation is also favourable with respect to long-term stability.
Nagra proposes the geological siting region Zürich Nordost for further investigation in Stage 3.
Siting area designated for the surface facility
The siting area ZNO-6b for the surface facility of a L/ILW repository in the siting region Zürich Nordost lies in the communities of Rheinau and Marthalen. It was selected in May 2014 based on collaboration with the siting 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 in Stage 3 using 3D seismics and exploratory boreholes. Definitive site selection will be made in Stage 3, with the initiation of the general licence procedure as specified 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 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. Following discussions with the region, Nagra then prepared four additional siting proposals and the regional conference thus evaluated a total of eight proposals.
In its interim report, the regional conference concluded that all the proposals were more or less unsuitable for locating the surface facility. The perimeter “Isenbuck/Berg” was also identified from the larger area; if the siting region Zürich Nordost is followed up further based on safety considerations, the placing of a surface facility within this perimeter will have to be considered. The boundary conditions that apply are also set out in the report.
Based on the collaboration within the framework of regional participation, Nagra then designated the siting area ZNO-6b as the potential area for locating the surface facility within the identified perimeter and taking into account the relevant boundary conditions.The siting area for the surface facility is located in the communities of Rheinau and Marthalen.
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. This is followed by further collaboration with the remaining siting regions on the concrete design of the surface facilities and possibilities for optimisation for integration into a possible general licence application.
|Geographical location of the siting area ZNO-6b (surface facility for a L/ILW repository).|
Siting area ZNO-6b for the surface facility
|Potential configuration of the components of the surface facility for a L/ILW repository.|
|Orthophotograph of the siting area in the communities of Marthalen and Rheinau. The area in red shows the space required for the surface facility of a L/ILW repository.|
|Possibility for integrating the surface facility into the surrounding landscape (photorealistic representation) for the example of the L/ILW repository, looking west (Bergholz).|
|A variant for a covered surface facility sunk lower into the landscape.|
The Opalinus Clay in the siting region Zürich Nordost is suitable as a host rock for a low- and intermediate-level waste repository.
In the Zürich Nordost siting region, two potential host rocks for a L/ILW repository were identified in Stage 1, namely the Opalinus Clay and the 'Brauner Dogger'. Nagra then carried out a safety-based comparison for these two options in Stage 2. Overall, both host rocks show a good barrier function: for the 'Brauner Dogger' there are however clear disadvantages compared to the Opalinus Clay. The Opalinus Clay therefore qualifies as the priority host rock for the L/ILW repository in the Zürich Nordost 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 (Clay-rich Lias, 'Brauner Dogger' clay sequences and the Effingen Member) also make a significant contribution to the barrier function. The siting region is very suitable in terms of available space in the preferred depth range.
|After optimisation, the disposal perimeter for a deep geological repository for L/ILW in the Zürich Nordost siting region comprises 6.5 square kilometres.|
|Geological profile from north-west to south-east through Zürich Nordost. The grey arrow marks the Opalinus Clay.|
Geological rock profile showing the rock strata occurring in the Zürich Nordost 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.)||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 (24 Nov.)||Together with representatives of ENSI and Nagra, the SFOE provides information on the proposals for geological siting regions at an event in Marthalen.|
|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.|
|2006 (28 June)||The Federal Council approves the „Entsorgungsnachweis" project, but rejects the request for identification of a site as being premature.|
|2005||Submission of a report setting out the options, in terms of potential host rocks and siting regions, for disposal of high-level waste (NTB 05-02, in German).|
|2002||Submission of the "Entsorgungsnachweis" feasibility study for high-level waste to the Federal Council. The project is based on the example of the Opalinus Clay in the Zürcher Weinland.|
|2001||Publication of the investigation reports for the Benken borehole (NTB 00-01) and the 3D seismic campaign (NTB 00-03).|
|1998 – 1999||Benken deep borehole.|
|1997||Extensive 3D seismic measurement campaign.|