Nuclear power plants must be properly decommissioned at the end of their working life, i. e. at the termination of the operational phase. This also applies to repositories for radioactive waste when the emplacement of waste has been completed. The dismantling of surface plant and machinery and the backfilling of the mine workings and shafts are, among other things, part of the decommissioning process of a repository. In so doing, the stored material is permanently isolated from the biosphere.