Regional Basic Professional Training Course in Korea

Regional Basic Professional Training Course (BPTC) on Nuclear Safety
generation and propagation of tsunamis in the ocean and the response at any shore.
Seiches
When the site is near an enclosed or semi‐enclosed body of water (lake, port, narrow
estuary), oscillations of the mass of water may be caused by storm waves, variations of
the wind velocity, or a local landslide or earthquake. They may affect the water intake
and discharge structures and induce extreme high or low tides.
The site platform anchorage level is determined by a probabilistic analysis taking account
of extreme tides with respect to the astronomical years.
5.3.3.2. Continental floods
Floods following precipitation
At continental sites, floods most often follow precipitation, basically rain or snow.
Using the data gathered, two approaches are possible. The deterministic approach
attempts to evaluate a water level from the maximum precipitations reasonably
foreseeable on a catchment basin. Probabilistic methods attempt to determine this same
level by an analysis of the variations recorded in the past.
Floods following failures of dams
The collapse of water works as a result of hydrological or seismic causes or landslides in
a reservoir or the deterioration of a dam by age can cause very dangerous sudden floods.
The assumed mode of collapse of the dam takes account of its type of construction and of
the topography of the bed of the water course just downstream of the dam. The duration
and speed of collapse of the dam are determined by erosion calculations, by assuming
that a section fails or a breach forms. These calculations give the hydrogram of the
outward flows. From this information, the equations of hydrodynamics can be used, with
assumptions concerning the bed of the river (friction), to evaluate the level of the flood
❙ 336 ❙