In 2009, as in previous years, ENSI rated the operation of the Swiss nuclear facilities as safe. Nevertheless, it was not an optimal year for nuclear safety. After systematic safety reviews at the Leibstadt and Mühleberg nuclear power plants, ENSI awarded both facilities a «good» rating. Both facilities were able to maintain the high safety levels achieved during the previous three years.
For the Leibstadt plant, the available data show that nuclear safety has improved in recent years. On the other hand, ENSI could only award a «satisfactory» rating to the Beznau and Gösgen nuclear power plants. In both cases, deficits in organisation and quality assurance were the reason.
At Beznau, this resulted in two members of staff being exposed to inadmissible levels of radiation.