Strategic oversight of ENSI
Every four years, the ENSI Board sets objectives for ENSI in the form of a performance mandate. These objectives are specified each year in a performance agreement. In its activity and business report, the ENSI Board informs the Federal Council every year of progress towards achieving these objectives. The report for 2025 (in German) was approved by the Federal Council on 5 June 2026.
Long-term operation and shutdown of Gösgen Nuclear Power Plant
As the operating life of Swiss nuclear power plants increases, questions of maintenance are becoming increasingly important. In 2025, the plants carried out extensive modernisation measures, which were reviewed by ENSI.
The prolonged shutdown of Gösgen Nuclear Power Plant also required intensive oversight by ENSI. The trigger was a possible design weakness in the feedwater system.
Deep geological repository and research reactor project
At the end of 2024, Nagra submitted two general licence applications – one for the deep geological repository and one for the fuel encapsulation plant. In 2025, ENSI checked whether the documents were complete. The subsequent detailed review is expected to be completed in 2027.
Together with a private company, the Paul Scherrer Institute (PSI) is planning a nuclear test facility for a thorium molten salt reactor. Assessing novel technologies of this kind requires specific expertise. Targeted competence development, access to international expertise and regulatory safety research are therefore of strategic importance for ENSI.
In its report for 2025, the ENSI Board concludes that ENSI largely achieved its objectives and carries out its oversight responsibly, effectively and to a high standard.