BfS is going to enforce sealing of chamber 4 of the Asse mine
Date 2009.01.16
By way of precaution, the Federal Office for Radiation Protection (BfS), intends to stabilise the sealing of emplacement chamber 4 of the Asse II mine with concrete. Today, BfS requested consent to the procedure by the competent Landesamt für Bergbau, Energie und Geologie (LBEG) and by Repository Surveillance. Repository Surveillance has already given its consent. An in-situ inspection of the damaged chamber 4 by experts of BfS and the Laender Mining Surveillance on 15 January had confirmed earlier that this measure is technically feasible and reasonable.
The inspection had shown that in case of a piece of rock falling from the roof and onto the waste stored in the particular chamber, which cannot be excluded, the existing plug to the chamber would very probably remain tight and, thus, no radioactivity would be released, either. However, no calculational proof can be established for this assumption. In order to ensure on all accounts a safe sealing of the chamber and, thus, to exclude the release of radioactivity, BfS, by way of precaution, is going to enhance the existing sealing with an additional concrete plug. One will immediately start preparations for this enforcement. Works are scheduled to be completed at the end of January. Through the planned measure it will be ensured that it will continue to be possible to retrieve the waste and that no options for action will be impeded.
A so-called special operating plan presenting the technical implementation is currently being developed and will be submitted to LBEG in the next week. Federal Environment Ministry and Lower Saxony Environment Ministry were informed, too.
In the medium and long term, it is planned to stabilise the chamber in such a way that a collapse can be excluded for the time until Asse will be finally closed. This could be achieved, for example, through backfilling the damaged chamber. However, a fundamental rock-mechanical and radiological evaluation of the situation in situ is essential for the further proceedings. BfS has already commissioned corresponding investigations. First assessments can be expected at the end of January, an expert talk with all institutions involved is to take place on 29 January.