The search for potential sites for a final storage site for radioactive waste is going forward in Switzerland.
In the course of these efforts, DMT GmbH & Co. KG has concluded two-dimensional, deep seismic exploration surveys on behalf of the National Society for the Storage of Radioactive Waste (Nagra).
These surveys were carried out in two regions: Jura Ost and Nördlich Lägern. DMT, headquartered in Essen, Germany, won the contract following international tendering. The scope of the assignment included enhancing existing seismic sections to achieve denser coverage enabling a more thorough exploration of the geological structures.
The work in the prospect area, executed at altitudes between 315 and 850 meters above MSL, began in October 2011 and was finished in March 2012. The 116,000 working hours and 587,650 kilometres covered by vehicles were accident-free. To explore the subterranean geological structures, reflection seismic recordings were made along a grid of 20 lines, with a total length of 320 kilometres. The 18,000 geophones positioned along those lines, at locations selected in close liaison with Nagra, recorded the data from 38,000 vibration points and about 2,000 shot points (explosive charges). Precise information about the location and thickness of underground geological structures can be derived from the travel time of the impulse reflections.
"Particularly worth mentioning are the excellent management of the crew, the education and skills of the people involved, and DMT's outstanding technical capabilities of the demanding vibroseis technology," explained Dr. Uwe Köhler, Field Survey and Engineering Department Manager at Nagra. "All these were augmented by efficient and timely quality control analyses, the highest safety standards, a pleasant working atmosphere, and good cooperation with the local population."
For more information, visit www.dmt.de/en/home.html