Expected main effects of flooding on nuclear power plant sites

The effects of flooding on a nuclear power plant site may have a major bearing on the safety of the plant and may lead to a postulated initiating event (PIE) that is to be included in the plant safety analysis. The presence of water in many areas of the plant may be a common cause of failure for safety related systems, such as the emergency power supply systems or the electric switchyard, with the associated possibility of losing the external connection to the electrical power grid, the decay heat removal system and other vital systems. Details are provided in Ref [6]. 

The dynamic effect of the water can be damaging to the structure and the foundations of the plant as well as the many systems and components located outside the plant. In such cases there could also be major erosion at the site boundary, which should be studied and taken into consideration. 

A flood may transport ice floes in very cold weather or debris of all types which may physically damage structures, obstruct water intakes or damage the water drainage system. 

Flooding can also contribute to the dispersion of radioactive material to the environment in an accident [7]. Such an effect should be considered in the 

Other information on the causes and effects of flood induced phenomena may be found in other Safety Guides relating, respectively, to earthquakes [2], wind and snow [4], groundwater flow [3], and dispersion in air, water and groundwater [7]. 

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EXPECTED MAIN EFFECTS OF FLOODING ON NUCLEAR POWER PLANT SITES... 

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