Seismic evaluation or re-evaluation is an important issue with many existing nuclear power plants (IAEA/NSR/2002, 2003). This may be required to take account of new information that has come forward since the original evaluation. In some cases better margins can be demonstrated with the availability of new analysis techniques. It may be that older conservative safety margins are not considered sufficient in the light of present day requirements or that original evaluations were inadequate.

There are a number of supporting facilities that also require seismic evaluation. These include laboratories, research reactors and fuel cycle facilities. In general the cases for these facilities are less advanced and they present a wide range of different situations. Seismic evaluation of existing nuclear facilities is the subject of a recent IAEA international meeting in 2003 (IAEA/NSR/2002, 2003; IAEA International Symposium, 2003).

A number of IAEA Member States have on-going seismic upgrading programmes to improve the safety of their operating plant.