Experts: Stability provided for until 2020

According to more recent calculations, the Asse nuclear repository’s stability is provided for until 2020 unless the inflow of saline water increases. This is the result of an expert discussion initiated by the Federal Office for Radiation Protection (BfS). It will be important to accurately observe and analyse the inflow of saline solutions and the micro-seismic events in the rock. Since the beginning of the year, BfS has been the new operator of the facility. The former operator, Helmholtz Zentrum München, had previously stated that the Asse mine would only be stable by 2014.

In the course of the technical discussion, the experts evaluated data of 2008 when the rock of the Asse repository had been monitored. There was consensus among the experts that there was a residual stability of the mine until 2020, this being a scientifically reliable forecasting horizon. During this period the mine could be kept open. Thus, there is more time to examine and implement various options to close the repository, including the examination whether the waste can be retrieved from the repository.

However, the condition for the forecast until 2020 is that the moistness in the bearing walls of the emplacement chambers will not increase. Should the inflow from the overburden clearly increase, the cracks in the chambers could become larger. There was consensus among the experts that the still open cavities in the already backfilled chambers should be closed as soon as possible. A first step is the backfilling of the so-called roof clefts. BfS will shortly present a detailed plan on this issue. Furthermore, BfS is considering reasonable and necessary tasks to seal existing flow paths of the influent saline solutions.

The results of the expert talk have been coordinated, among others, between BfS and Lower Saxony Environment Ministry.