In the design, natural and other catastrophic events are taken into account and a site study is performed to identify local natural and extreme catastrophic events. After identification of the natural or man induced risks, it is studied as to their potential impact on the plant site or equipments and functions. It is then incorporated as design basis external events and a study of their potential consequences in terms of emergency preparedness is performed. Later on, during the operational phase, monitoring of the various parameters is performed regularly and reviews of the sites also.
During the design phase, natural and other catastrophic events are taken into account and since they very much depend on the site and the country, a site study is a prerequisite. During the study many events which could take place at the site location are identified natural and extreme external events or man induced ones.
Availability and reliability of external electrical supply and water as well as feasibility of emergencies routes are appraised for cases of nuclear accident emergencies. Population density, dominant winds are also part of the site evaluation.
Natural hazards such as meteorological events - extreme temperature, extreme atmospheric moisture, snow precipitation (also blizzards) and ice pack, lightning - are studied as to their potential consequences and plant vulnerability.
Concerning extreme natural phenomena - earthquakes, volcanoes, tsunamis, tidal waves etc - a risk based approach is performed with a detailed comparison among the sources of events.
A site selection implies the following steps: identification of risks due to external events or man induced events, study of their potential impact on the plant site or equipments and functions, incorporation of the selected event as design basis external events and study of potential consequences in terms of emergency preparedness. Later on during the operational phase, monitoring of the various parameters is performed regularly and reviews of the sites can also be performed.