This Safety Report provides up to date detailed guidance on actions to be taken in preparation for, and following, an earthquake at a nuclear power plant, taking into account the knowledge gained and the experience of Member States from the occurrence of strong earthquakes that affected nuclear power plants up to 2010. The publication is a compilation of available references based on related standards and proposes a more comprehensive set of criteria than those existing in some national regulations, based on damage and earthquake exceedance levels for dealing with situations related to plant shutdown, plant restart or plant continuing operation following the occurrence of an earthquake which may exceed the original design level. It will be a useful tool for regulatory bodies, specialists on earthquake engineering and technical support organizations.