The regions, in which, in Switzerland, a deep geological repository for radioactive waste could be built, are known. But to be able to the safest location to choose, has started the Nagra on Monday in the Region North of Lägern, to drill in depth.
The drilling site is located in the Zürcher unterland, outside of Bülach ZH on an otherwise agricultural area of one hectare. The National cooperative for the storage of radioactive waste (Nagra) wants to complement this first series of deep holes in the image of the geological subsurface.
"We are straight after years of working slowly on the goal," said Maurus Alig, Total project Manager at Nagra, in front of the media. "The data we collect now with these holes, to serve us, to find the best and safest place for a deep geological repository."
First measurements had shown in the past: In the regions Jura Ost, North of Lägern and Zürich Nordost, a storage for radioactive waste is in principle possible. How 3D showed seismic measurements, is the surface ideal, and it has plenty of space.
composition of the opalinus clay
Now, however, are at these locations are still carefully examined, as the Rock is in the depth. The drill, which was taken on Monday, will now be six to nine months of round-the-clock operation. In a first step, he's digging several hundred meters in depth.
The opalinus clay, the host rock in which the underground storage is to be built, is located about 900 meters below the earth's surface. With the holes but also the over - and underlying layers of rock are to be investigated, such as Alig said. "We're looking for in the samples, the important characteristics that must be met for a camp."
So it goes, for example, to examine the thickness, the permeability and the composition of the host rock and the adjacent rocks. "Also important is the clay content," said Alig. The higher this is, the more waste is included." You'll drill until you've found the first place.
Next holes in Trüllikon
Overall, has submitted to the cooperative for the three possible regions of the Swiss Federal nuclear safety Inspectorate (Ensi) 23 applications for holes. How many are really carried out, depends on the results. Per site it will be in accordance with the Alig, around two to three. A bore will cost 15 million Swiss francs.
The Nagra hopes to complete by the deep holes, "the geological overall picture of the location regions." This will ensure that a scientifically justified choice of the first deep-storage sites can be made. "In 2022 we should know where the camp could be built," said Alig.
Then the appropriate framework permit applications are prepared and submitted. After planning by the Nagra, it will be 2031, up to the people to decide, and by 2050 will be built. Next, it is now performed in the summer of the second deep hole, in the location area of Zurich North in Trüllikon. (nag/sda)
Created: 15.04.2019, 16:31 PM