The concept of risk from the point of view of science and technology

The author presented a review of the concept of risk assessment for nuclear installations from the point of view of science and technology. He stressed the necessity to put deterministic statements on an empirical foundation which, however, is not possible in practice due to the generally positive operating experience obtained so far with nuclear power plants. This is why probabilistic methods have to be applied, a framework concept being developed by GRS. The author further discussed in detail the probabilistic safety criteria currently discussed in the USA and explained the four criteria presented in the NRC proposal. (WB)