Aseismic design of turbine houses of nuclear power plants

The turbine house does not belong to the safety-related parts of equipment of a nuclear power plant. A special protection against earthquakes is not demanded by the authorities as long as it is proven that safety-related parts of equipment will not be restricted in their function by a collapse of the turbine house. The degree of an aseismic design is largely up to the customer, who has to weigh the risk of costs and availability against the additional costs that are necessary for the earthquake calculation and for constructive hardening. In comparison to the high-tuned turbine foundations as they are in use in the USA today, low-tuned turbine foundations as a result of helical-spring-support, which are constructed by the KWU exclusively, pose special problems with the aseismic design. This is discussed in this report. (Auth.)