The Swiss Federal Nuclear Safety Inspectorate (ENSI) has reinforced its message to nuclear power plants that they should beef up their defences against earthquakes.
Having warned the five plants last summer that they would have to improve their safety margins, ENSI on Monday gave details on what would be expected of them, together with a four-year timetable. This includes new methods to measure the seismic resistance of equipment designed to control the effects of an earthquake.
“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 earthquake,” the inspectorate stated.
ENSI director general Hans Wanner explained that new models to determine the safety of power plants were sparked by the 2011 Fukushima disaster in Japan.
“This is precisely why we are so keen to ensure that nuclear plant operators regularly update their comprehensive seismic safety cases and that these then comply with the latest scientific evidence – especially if this evidence suggests that stricter requirements are now necessary,” he said.
Even the Mühleberg power plant will have to comply with the new requirements despite being mothballed in 2019. The Swiss government decided in March 2011 to decommission all five power plants between 2019 and 2034.
In August of last year, Greenpeace, other NGOs and local residents close to the Beznau station in canton Aargau threatened legal action after citing serious environmental risks associated with the two plants.