Serious researches over nuclear security were held after the most dangerous this type accident in the world - Chernobyl. New reactors constructions were postponed or abandoned. However development has not been stopped. Since then, care about nuclear security has become major issue. These concerns put into R&D has brought significant security level increase. As it is shown in Figures no. 34 and 35 number of security incidents after years 90's has decreased. Today, there is only 0,5 of unplanned shutdown per almost one year reactor operation (1000 MWe reactor). [83]
In the same period, also industrial safety accident rate has been reduced from 5,2 to 0,92 per 1 mil person hours worked. This factor includes all nuclear industry and has been constant since last years.