Deep geological repositories

The Nuclear Energy Act of 2003 specifies that radioactive waste is to be disposed of in deep geological repositories in order to ensure the long-term protection of man and the environment. The Swiss waste management concept foresees two deep repositories: one for high-level waste and one for low- and intermediate-level waste.

The repositories will be constructed at a depth of several hundred metres in suitable rock formations. Depending on the type of waste to be emplaced, they will consist of disposal tunnels or caverns, a pilot facility for monitoring a representative component of the waste, a rock laboratory, infrastructure installations and access tunnels or shafts. During the construction and operational phases, additional structures are also required at the surface. During the construction and operation of the repository, additional installations are required at the surface. The waste will be delivered here and prepared for emplacement in the repository.

In the repository itself, a system of staged engineered safety barriers isolate the waste and ensure the long-term protection of man and the environment. These barriers include, for example, suitable packaging of the waste and backfilling of the disposal tunnels.

Once the monitoring phase is over, the repository and accesses are backfilled and sealed. Closure is carried out stepwise, with periodic observation phases.