The tenth Review Meeting of the Convention on Nuclear Safety (CNS) took place from 13 to 24 April 2026 at the International Atomic Energy Agency (IAEA) in Vienna. In respect of its National Report, the Review Meeting recognised Switzerland in four areas of good performance and identified one key challenge concerning the long-term availability of technical expertise.

• Areas of good performance

  1. International cooperation, transparency and openness

  The Contracting Parties acknowledged Switzerland’s close cooperation at both European and international level. Particularly noteworthy was Switzerland’s voluntary participation in the EU’s second Topical Peer Review on fire protection in nuclear installations from 2022 to 2025. Switzerland submitted a National Report and also provided experts for the peer review.

  2. Progress in dismantling Mühleberg Nuclear Power Plant

  The rapid dismantling of Mühleberg Nuclear Power Plant was also assessed positively. Decommissioning started promptly and has made significant progress. In particular, it was highlighted that the last spent fuel had already been removed from the site before 2024, which was earlier than originally planned.

  3. Modern regulatory framework for low-hazard installations

  The development by ENSI of a regulatory framework for low-hazard installations was cited as a further example of good performance.

  4. Ongoing updating of natural hazard analyses

  Switzerland continuously updates its natural hazard analyses and the associated probabilistic and deterministic safety analyses in line with the latest state of science and technology. This too was expressly praised.

• Challenge

  Challenge 1:

  Switzerland should develop an overarching national competence strategy for all relevant actors in order to ensure the long-term sustainability of nuclear expertise and human resources.

  This underlines the importance of training, promoting young talent and preserving knowledge in the nuclear sector – especially against the backdrop of ageing workforces and long-term projects such as decommissioning and waste disposal. A similar recommendation was already identified by expert teams both in the IRRS Mission 2021 and the IEA Review 2023 in Switzerland.

The “Country Review Report” contains a detailed summary of the Swiss review process.

“The findings of the Review Meeting demonstrate that, in international comparisons, Switzerland continues to have a high level of safety. At the same time, the identified challenge makes it clear that targeted investments in technical expertise and knowledge retention will remain necessary going forward,” stated ENSI Director General Marc Kenzelmann.

Once again, the meeting took place against the backdrop of the tense international situation. A central topic was the situation surrounding the Russian-occupied Zaporizhzhia Nuclear Power Plant in Ukraine. Many delegations stressed the importance of nuclear safety and security, including in armed conflicts, as well as the role of the IAEA on site.

Marc Kenzelmann also underlined the importance of international exchange: “The Convention on Nuclear Safety is a key instrument for the continuous improvement of nuclear safety worldwide. Particularly in such a geopolitically difficult time, it is crucial that regulatory authorities maintain an open dialogue, share experience and strengthen shared safety standards.” He continued: “In view of the current dynamic developments in the operating environment, whether new reactor technologies, the rapid development of artificial intelligence, increasing cybersecurity risks or climate-related impacts, it is important that Switzerland monitors these developments closely and responds appropriately within the scope of its possibilities and resources. This also includes looking beyond Europe and taking greater account of international developments.”

The currently tense geopolitical situation was also reflected in the final negotiations. The Contracting Parties engaged in lengthy and hard-fought debates over the content of the Summary Report. Thanks to Swiss mediation, the Summary Report was ultimately adopted by consensus. This is crucial because the report sets out the main findings of the Review Meeting and serves as a basis for the Convention’s continued development. It sends an important political signal and underlines the success of Swiss mediation.

The eleventh CNS Review Meeting will take place in April 2029.

The Convention on Nuclear Safety (CNS) is an international convention that was adopted in 1994 and entered into force in 1996. Its purpose is to achieve and maintain a high level of nuclear safety in nuclear power plants all over the world. The 98 Contracting Parties undertake to submit regular National Reports and evaluate each other within the framework of Review Meetings.

Further Information

Convention on Nuclear Safety: Switzerland submits 10th National Report to the IAEA