Additional documentation on the engineering feasibility of a deep repository has been submitted by Switzerland’s national radioactive waste disposal cooperative Nagra. It claims there are no safety advantages to constructing a deeper repository than originally envisaged. In January 2015, Nagra proposed that further investigations are carried out at the proposed siting regions of Zürich Nordost and Jura Ost in the third and final stage of Switzerland’s plan for selecting sites for two repositories: one for low- and intermediate-level waste (LLW/ILW) and the other for high-level waste (HLW). It also said the four other regions under consideration in the second stage – Südranden, Nördlich Lägern, Jura-Südfuss and Wellenberg – will be placed in reserve. The six sites were proposed in November 2011 during the first stage of the selection process. Nagra is required to propose at least two regions to host each of the repositories for further investigations in the third stage. Last September, the Federal Nuclear Safety Inspectorate (ENSI) requested that Nagra submit additional technical documentation related to the optimization of the repository depth in terms of safety. It was required to show whether construction at greater depth involves disadvantages in terms of safety and whether modifying the repository concept would be advantageous for such depths.
World Nuclear News 11th Aug 2016 read more »