FASTENINGS IN NUCLEAR POWER PLANTS QUALIFIED FOR EXTREME ACTIONS DUE TO DESIGN BASIS ACCIDENTS AND SEVERE ACCIDENTS

摘要

For nuclear power plants design basis accidents as well as severe accidents have to be considered in view of necessary plant engineering measures. These measures require safety-related components and building structures which have to be designed for extreme actions resulting from both groups of accidents. These extreme actions are, for example, actions due to seismic events, airplane crash, chemical explosions or LOCA (loss of coolant accident). For the anchoring of those safety-related components or structural elements in concrete structures adequate safety-related fastenings have to be applied. These fastenings are subdivided into two groups: cast-in fastenings (anchor plates with headed studs and anchor channels) and post-installed metal anchors (expansion anchors, undercut anchors or bonded anchors). Among headed studs and metal anchors in particular the use of anchor channels has become important in recent years. Regarding the design and safety concept of safety-related fastenings the effects of extreme action effects are of vital importance. So for example the load bearing of anchors has to be guaranteed in cracked concrete structures with large crack openings in a single crack considering cyclic loading typically for seismic events. The different demands on safety-related fastenings with anchors have been established in the German DIBt-guideline (2012) which also can be applied for headed studs and anchor channels. This guideline specifies the licensing of metal anchors and the design of anchor connections. Regarding this guideline in addition to the status report KTA-GS-80 (2013) all relevant aspects for safety-related fastenings will be presented in this paper.