The book describes the methods of risk analysis and explains the procedures and results of a number of studies including the German Risk Study, Phase B and NUREG-1500. After defining basic concepts the methods of risk analysis are treated. In the field of nuclear energy studies for light water, fast breeder and high temperature reactors and for the nuclear fuel cycle are discussed; their relevant results are presented. Additionally, precursors to servere accidents are dealt with. Risk studies for process plants are described; their objectives and methods of analysis are compared. Furthermore, their approaches are compared with that of the German Risk Study, Phase A. Risk comparisons for nuclear, conventional and renewable energy sources are critically examined. Technical and legal aspects of the safety evaluation for nuclear power plants in the FRG and the potential of the combined use of the deterministic and probabilistic approaches are discussed. The book concludes with an overview of probabilistic safety goals in different countries.