Asse – Workers found radioactively contaminated debris during drilling operations

After having carried out first measurements, a radiation protection officer determined that the debris that had been found in the process of drilling in a depth of 750 metres, was humid and radioactively contaminated. During the operations, the hand of a worker was contaminated. The measured radioactivity was clearly below the permissible limit value. Health detriments can be excluded. The staff of the Asse-GmbH decontaminated the hand that had come into contact with the debris as well as the drill and workplace.

If humidity occurs in the process of works, drilling operations inside the mine generally discontinue and investigations are initiated. The humidity in the debris was low. It could not be detected that the work area or visible solutions were saturated.

The debris is currently evaluated. It must be assumed that these were residual contaminations dating back to the time the waste was emplaced. Such residual contaminations can also be found at other places on the ground of the 750-m level. Further examinations are to clarify how to avoid contact with these areas during drilling operations in the future.

The drilling operations were required to examine the area near emplacement chambers 11 and 12. It is planned to backfill residual cavities in the upper area of the former gallery between the chambers with concrete in the scope of the necessary stabilisation measures.