Evaluation of Seismic Safety for Nuclear Installations

This Safety Guide provides recommendations on the seismic safety evaluation of nuclear installations. It addresses all types of new and existing nuclear installations. This Safety Guide presents three assessment methodologies: the deterministic approach, generally known as seismic margin assessment (SMA), seismic probabilistic safety assessment (SPSA), and a combination of SMA and SPSA known as ‘probabilistic safety assessment (PSA) based SMA. This Safety Guide provides specific recommendations on applying a performance-based graded approach to the seismic safety evaluation of nuclear installations other than nuclear power plants. It also covers the relation between seismic safety margins and defense-in-depth (DiD) level 3 and level 4. For new nuclear installations, this Safety Guide provides recommendations to assess adequacy of seismic margin to avoid cliff edge effects considering DiD level 3 and level 4. This publication is intended for use by regulatory bodies, operating organizations, and designers of nuclear installations.