Severe accidents management in PWRs

The main lesson from the Fukushima nuclear accident is that a nuclear facility must be prepared to handle catastrophic events. The operators of nuclear facilities have taken several actions based on lessons in order to enhance the ability of nuclear energy facilities to remain safe even if there is an extended loss of electric power. They have started to adopt strategies to mitigate events beyond the design envelope for nuclear energy facilities. This paper deals with implementation of some measures to existing nuclear power plants which do not include severe accident mitigation measures in their original design projects. It discusses the contribution of severe accident mitigation measures on the limitation of radiological consequences.