Switzerland zeroes in on deep geological repository site

September 14, 2022, 7:00AMRadwaste Solutions
An illustration of Switzerland’s proposed deep geological repository. (Image: Nagra)

Nagra, Switzerland’s national cooperative for the disposal of radioactive waste, has announced that it has selected Nördlich Lägern as the site for a deep geological repository for radioactive waste. According to Nagra, extensive investigations have shown that Nördlich Lägern, located in northern Switzerland near the German border, is the most suitable area for a geologic repository with the best overall safety reserves.

Nagra also plans to build a spent fuel encapsulation plant at the Zwilag interim storage facility in nearby Würenlingen. As the Zwilag facility has been in operation for years, this solution is expected to offer organizational and ecological advantages.

Nagra will now prepare general license applications for the repository, aiming for submittal to Switzerland’s Federal Council in 2024.

The selection process: The Swiss government began its search for a geological repository in 2008, looking at the whole of the country. By 2018, it was decided that three sites should be investigated for further study: Jura Ost, Nördlich Lägern, and Zürich Nordost.

Nagra determined that all three siting regions were capable of hosting a repository but that Nördlich Lägern is the most suitable. By choosing Nördlich Lägern, Nagra revises its 2015 assessment that found that, based on available data, constructing a repository at the site would be more challenging from an engineering perspective.

That assessment was criticized by the Swiss Federal Nuclear Safety Inspectorate as not being sufficiently supported by data. After further investigation, Nagra concluded that the large distance between Nördlich Lägern’s Opalinus Clay and the nearest water-bearing rock layer, as well as the clay’s ancient porewater, provided the best geological barrier for the waste. The organization also found that the site’s underground rock formations have the largest connected area without major geological faults, providing maximum flexibility for repository construction.

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