Adequate engineering for lowering the frequency of initiating events at Siemens/KWU

The analysis of TMI and Chernobyl events shows weak points and deficits in the field of preventive safety features. This should not be forgotten during the ongoing discussion on severe accidents. Therefore the paper explains special preventive safety features which were the results of the development of Siemens/KWU reactor technology. With respect to the present discussion on new reactor concepts special attention is given to the inherent and passive safety features and the engineering which results in low core melt frequency. Such an analysis leads to knowledge modules which are based on experience during licensing procedures and plant operation and should be the starting points for reactor technology of the future