09.12.20 - This morning both units of the Beznau nuclear power plant (KKB) were taken off grid in a controlled manner. During an inspection within the framework of earthquake safety verification, two of six emergency power diesels were found to have an assembly deviation in shock absorbers (vibration dampers). This must be corrected.
Even if the two affected diesel engines had failed in case of a severe earthquake, the safety of the KKB would have remained guaranteed due to the remaining emergency diesel engines.
The shutdown of the plants was due to the fact that the technical specification for the operation of the plant, for which the KKB is responsible and which must be approved by the authorities, stipulates this.
KKB immediately informed the authority of the case and initiated steps to correct the detected assembly deviation. The work is expected to take three to four weeks.
During the shutdown of the nuclear power plant, steam is visible from the non-nuclear part of the plant above the engine room. There is no danger to people and the environment.
The work is carried out under the supervision of the Swiss Federal Nuclear Safety Inspectorate ENSI.