The main concern with nuclear power plants and earthquakes is the structural integrity of the plant and the temperature of the reactor core. If the temperature goes into an uncontrolled state, the reactor will overheat and melt down with conceivable consequences.
Seismic monitoring is the primary measure used to avoid and mitigate potentially dangerous situations which could be caused by an earthquake. PGA (Peak Ground Acceleration) provides an idea of the real entity of a tremor. Magnitude alone does not affect PGA since the latter depends also on the depth of the earthquake.
When PGA exceeds a preset threshold, the seismic monitoring system alerts the central control center forcing a shutdown.
Our systems have been in use at the nuclear power plant of Caorso since 2002 with our previous company name and, as of 2015 the new Lunitek models are also being used in Trino Vercellese.
Even if both Caorso and Trino are no longer active nuclear plants, they need seismic monitoring because radioactive fuels are still present and need the utmost attention.