Franz Altkind, Head of the Electrical Engineering section

ENSI does not only grant approvals in the case of upgrading. Modifications to constructions, parts of installations, systems, equipment and documents that are classified as relevant for safety or technical security have to be approved by law – even in the case of decommissioning. If operators of nuclear power plants are planning such modifications, ENSI experts assess the projects in the light of national and international bodies of rules.

Modifications must be in accordance with the legal requirements, the ENSI guidelines and technical standards. This equally applies to the modernisation of machine techniques, electrical technology, measurement techniques and system technology. New buildings on the NPP site also have to be approved by ENSI. If a nuclear power plant is to be put back into operation after the annual audit, ENSI makes sure that all work is carried out according to operating instructions.

Approvals for major modifications to installations are usually carried out in stages: concept, technical implementation and the realisation of modifications each require separate approval. Approval for minor modifications can only be given in one step.

Approvals require close co-operation between the departments within ENSI. ENSI specialists assess how modifications being planned by operators will affect the safety of the installations, for instance. ENSI also cooperates with bodies of the Confederation and the cantons, as the leading authority, such as in relation to environmental aspects.