Seismic Design of Fastenings with Anchors in Nuclear Power Plants

For the connection of steel structures and mechanical components like steel platforms, piping systems or vent pipes to concrete structures fastenings with metal anchors will be used. In nuclear power plants safety related fastenings require an adequate seismic design which is based on nuclear specific standards like the German safety standard series KTA 2201 “Design of Nuclear Power Plants against Seismic Events”. This safety standard series defines demands on determining the design basis earthquake as well as the design requirements of components and building structures including dynamic analysis procedures. The different demands on safety-related fastenings with anchors have been established in the German DIBt-guideline with the specifications for the technical approval of metal anchors and for the design of anchor connections. This guideline considers extraordinary action effects like earthquake actions. For example the load bearing of anchors has to be guaranteed in cracked concrete structures with large crack openings considering cyclic loading typically for seismic events. In addition to the DIBt-guideline the status report KTA-GS-80 presents a review about safety related fastenings in nuclear power plants. This report comprehends the essential information about the design and safety concept of those anchor fastenings regarding the interface between mechanical and constructional engineering. In this context the high demands on the limitation of deformations represents an important design criterion for the components with the assumption of a rigid connection to concrete structures.