The site for the deep geological repository

Find information, images, graphics and videos about Nagra’s siting proposal here.

Which site is Nagra proposing and why? Four questions for Nagra CEO Matthias Braun

Media release

Nördlich Lägern is the safest site for a deep geological repository: here, the rock deep below the surface best confines the radioactive waste for a very long time. Nagra’s investigations demonstrate this. The siting proposal is an important milestone in the project of the century of deep geological disposal. The entrance to the repository is to be constructed in the community of Stadel, and the encapsulation plants for radioactive waste will be built at the Zwilag interim storage facility in the community of Würenlingen.

Detailed report

Nagra’s siting proposal

In Nördlich Lägern, the rock has the best containment capacity for the radioactive waste – not only today, but also in the distant future. A safe deep geological repository could also be constructed in Jura Ost and Zürich Nordost, but Nördlich Lägern has the greatest long-term safety reserves.

You can find more information about our siting proposal in our report.

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Important questions and answers

Radioactive substances are used in nuclear power plants and in medicine, industry and research. Radioactive waste is produced in the process and the waste producers are legally obliged to dispose of it safely. For decades, national and international experts have searched for the best solution to safely contain radioactive waste over a period of hundreds of thousands of years until it is no longer hazardous. Deep below the surface, time practically comes to a standstill, which is why there is broad consensus that deep geological disposal is the best solution. Switzerland has anchored the requirement for a repository in its legislation.

Nördlich Lägern is the most suitable site and has the largest safety reserves. This has been determined based on three key factors: 1. Here, the rock deep below the surface best confines the radioactive waste. Nagra detected traces of water dating back millions of years in the pores of the rock. The quality of the rock is highest here. 2. As it is extremely stable, the rock in Nördlich Lägern is best suited for confining the waste not only today but also in the distant future. The earth's surface will change over time, but the ground deep below the surface will not. The rock hosting the repository thus offers the highest protection here. 3. Nördlich Lägern has the largest area of suitable rock, providing Nagra with the greatest degree of flexibility for constructing the repository.

1. It is very tight. 2. Should fissures form in the Opalinus Clay, it can seal these itself as it swells on contact with water. This has been demonstrated in numerous experiments. 3. The Opalinus Clay can bind radioactive substances over long periods of time. It contains negatively charged platelets. Most radioactive substances in the waste are positively charged and therefore effectively stick to the Opalinus Clay, which prevents them from migrating through the rock.

In 2015, we were concerned that, based on limited data available at the time, constructing the repository in Nördlich Lägern would be more challenging from an engineering perspective. The Swiss Federal Nuclear Safety Inspectorate (ENSI) criticised that these concerns were not sufficiently supported by data. As a result, we investigated all three regions extensively. Our conclusion: it is possible to construct a safe deep geological repository in all three regions. From today’s point of view, Nagra’s initial assessment was too cautious.

The total cost for decommissioning and waste management will amount to CHF 23 billion. Of this, around CHF 3.5 billion will be used for the decommissioning of the nuclear power plants and the interim storage facilities. The remaining roughly CHF 20 billion are allocated for work in conjunction with the deep geological repository such as research, interim storage, construction and operation.

Nagra was tasked with proposing the safest site for a repository based on scientific and technical expertise. Discussions concerning compensation payments and measures do not fall under Nagra’s responsibility but under that of the radioactive waste producers.

The surface infrastructure will cover an area of just over 12 hectares. This is equivalent to around 24 football fields.

By placing the encapsulation plants at Zwilag in Würenlingen, we can make use of synergies with existing facilities. The site is already the competence centre for the conditioning and packaging of radioactive waste. Environmental aspects have also been considered: less forest will have to be cleared and less soil removed.

After decades of research, we will enter a new phase in the project of the century of deep geological disposal. We will prepare the general licence applications for submission in 2024. These will then be reviewed by the authorities. The decision to approve the licences will be made by the Federal Council and the Federal Parliament and, in case of an optional referendum, the Swiss voters. At least a further ten years will pass before the start of initial construction work.

How does a deep geological repository work?

Why Nördlich Lägern?

The path to the siting proposal

Well-founded data basis
Borehole investigations
Borehole investigations

In recent years, the Jura Ost, Nördlich Lägern and Zürich Nordost siting regions have been investigated in great detail. Our database is now so extensive and the picture of the underground environment so complete that Nagra can determine the best site for a repository.

Opalinus Clay
Opalinus Clay

The Opalinus Clay is largely impermeable to water, can self-seal fissures and has the capacity to bind radioactive particles. For these reasons, this clay rock is the most important geological barrier of the deep geological repository.

What's new at Nagra
The surface facility

The surface facility at Haberstal

The surface facility for the deep geological repository is to be constructed in the Haberstal area in the community of Stadel. Nagra has selected this site in collaboration with the region and Canton Zürich.

More information
The site for the encapsulation plants

Encapsulation plants at the Zwilag interim storage facility

The encapsulation plants will be constructed at the site of the interim storage facility in Würenlingen. Synergies with existing facilities and environmental considerations were the main factors supporting this decision.

After the siting proposal

What happens next?

Following the siting proposal, we will prepare the general licence applications and plan to submit these to the authorities for review in 2024. Around 2029, the Federal Council will decide whether to grant the general licences and will submit its decision to the Federal Parliament. A national referendum can be called for against this decision. The final decision is expected for 2031.

Time schedule through 2125
Your contact persons
Patrick Studer
Patrick Studer

Head of Communication / Media Spokesperson

Jagna Züllig
Jagna Züllig

Deputy Head of Communication / Media Spokesperson

Felix Glauser
Felix Glauser

Media Spokesperson