Swiss federal authorities

Nuclear Facilities

Switzerland has the following nuclear power plants: Beznau (units 1 and 2), Gösgen and Leibstadt. Also in operation is a research reactor at the Federal Institute of Technology in Lausanne (EPFL). The Central Interim Storage Facility for radioactive waste (Zwilag) and the Federal Government’s Interim Storage Facility in Würenlingen are also monitored by ENSI.

The no longer operational Mühleberg Nuclear Power Plant is being decommissioned. Three research reactors at the Paul Scherrer Institute PSI in Würenlingen have nearly been fully dismantled.

  • NPP Beznau
    Beznau NPP comprises two largely identical two-loop pressurised water reactor units, which began commercial operation in 1969 and 1972 respectively. The net electrical output per unit is 365 MW.
  • NPP Gösgen
    Gösgen NPP is a three-loop pressurised water reactor system. It began commercial operation in 1979. The net electrical output is 1010 MW.
  • NPP Leibstadt
    Leibstadt NPP is a boiling water reactor that began commercial operation in 1984. The net electrical output is 1233 MW.
  • Former Mühleberg Nuclear Power Plant (permanent shutdown)
    Mühleberg NPP, which began commercial operation in 1972 and shut down in 2019, was a boiling water reactor with a net electrical output of 373 MW. Mühleberg NPP ceased power operations on 20 December 2019. In 2020, all fuel elements were transferred from the reactor pressure vessel to the fuel pond and the necessary measures implemented to establish safe technical post-operation. In 2022 and 2023, during decommissioning phase 1, Mühleberg NPP transported all its fuel elements to the Central Interim Storage Facility of Zwilag in Würenlingen, completing the first decommissioning phase in 2023. Since then, Mühleberg NPP has been in decommissioning phase 2.

 

Decommissioning of the following plants has been completed:

  • Lucens experimental nuclear power plant
  • Basel University Research Reactor
    Up until its final shutdown in 2015, the research reactor of Basel University was used to teach students and for neutron activation analysis. After the Federal Department of the Environment, Transport, Energy and Communications (DETEC) had ordered the decommissioning of the research reactor on 13 February 2019, ENSI approved the dismantling of the plant. Dismantling was completed in 2019. With the removal of the plant from federal government oversight, the first decommissioning project in Switzerland under the current nuclear energy legislation was completed.

News

  • News, Posts

    Beznau and Gösgen nuclear power plants must check their steam generators

    The Swiss Federal Nuclear Safety Inspectorate (ENSI) requires that the Beznau and Gösgen nuclear power plants check the quality and design of the forgings of the steam generators in respect of adherence to the material specifications. In doing so, ENSI is reacting to information from France.

  • News, Posts

    ENSI reviews reactor pressure vessel safety case submitted by Beznau 1

    Monday, Axpo submitted the documents for characterisation and assessment of the findings in the base material of the Beznau 1 reactor pressure vessel. The Swiss Federal Nuclear Safety Inspectorate (ENSI) will review these and decide whether Beznau 1 nuclear power plant will receive permission to restart. In its assessment, ENSI will be advised by the…

  • News, Posts

    Swiss nuclear power plants are unaffected by irregularities at the Le Creusot Forge

    The Swiss nuclear power plants use forgings for the safety-relevant main components with fully documented manufacturing and material quality certificates. This was confirmed by the operators in response to an enquiry made by the Swiss Federal Nuclear Safety Inspectorate (ENSI).

  • News, Posts

    Updated seismic hazard assumptions require new safety cases to be drawn up for Swiss nuclear power plants

    The Swiss Federal Nuclear Safety Inspectorate ENSI has set out new requirements for assessing seismic hazards in Swiss nuclear power plants in the light of the latest scientific findings. Plant operators are required to provide further proof, in three stages, by the end of 2020, that their plants can withstand even an extremely unlikely powerful…

  • News

    ENSI reviews Axpo’s project plan for the safety case of the Beznau 1 reactor pressure vessel

    Axpo submitted today a project plan (road map) to ENSI, the Swiss Federal Nuclear Safety Inspectorate, outlining procedures for the characterisation and evaluation of the indications in the base material of the Beznau 1 reactor pressure vessel. ENSI will review this plan in collaboration with a group of international experts.

  • News

    “Only an ultrasonic examination is capable of providing authoritative information regarding the current condition of the reactor pressure vessel.”

    The Swiss Federal Nuclear Safety Inspectorate (ENSI) requires the Beznau nuclear power plant to provide proof that the reactor pressure vessel is safe. In an interview, Georg Schwarz, the Director of the Division for Nuclear Power Plants and Deputy Director of ENSI, explains the importance of carrying out ultrasonic inspections.

  • News

    Beznau 2 can continue operating until the start of the annual overhaul in mid-August

    Block 2 of the Beznau nuclear power plant does not have to be shut down early. The operator Axpo was able to plausibly demonstrate to the Swiss Federal Nuclear Safety Inspectorate ENSI that even if one were to assume that the reactor pressure vessel of Beznau 2 had similar material defects to those in Beznau…

  • News

    More investigations are needed on the reactor pressure vessel of Beznau 1

    While carrying out ultrasonic measurements of the reactor pressure vessel of the Beznau 1 nuclear power plant the operator detected flaw indications that require evaluation. It submitted a corresponding report to the Swiss Federal Nuclear Safety Inspectorate ENSI yesterday. Beznau 1 is presently inactive because of the main annual overhaul. ENSI is now awaiting an…

  • News

    ENSI is also focusing on safety culture

    A good safety culture is necessary in order to ensure that technical installations are safe. There is widespread agreement on this point across all specialist disciplines and sectors. ENSI, the Swiss Federal Nuclear Safety Inspectorate, also gives consideration to safety culture in its supervisory work. In a new report on supervisory practice covering various issues,…