The deep geological repository consists of a test zone, a pilot storage area and a main section. The test zone is used to study the construction and operation of the deep geological repository. The pilot storage area is used to monitor the behaviour of the barrier system. Radioactive waste is deposited in the main section.
A deep geological repository is brought into operation gradually. The pilot storage area is used for long-term monitoring and is sealed before waste is deposited in the main section. This means any unfavourable developments can be identified early leaving time to implement the necessary measures. After the waste has been finally deposited the galleries are sealed.
Following upon the storage operation, the legislation stipulates a monitoring period during which it has to be possible to recover the waste easily. The monitoring phase enables operators to identify any unfavourable developments early leaving time to implement the necessary measures. New scientific knowledge and new types of technology can also be implemented during this time and changes can be made if required.
Once the monitoring phase has been concluded, parts of the facility which are still open can be backfilled and sealed. The deep geological repository will only be finally closed when safety can be guaranteed.