Seismic performance of fuel assemblies and impact force correlations with intensity-compatible sets of recorded ground motion time histories

Highlights: • Fuel assembly analyses for historical ground motions compatible with site hazard. • Maximum impact forces between spacer grids show large margins against buckling. • Regression of impact forces over principal components better than individual IM. • UHS-based excitation gives higher impact forces than most recorded ground motions. • Variability of impact forces mainly driven by ground motion variability. In the present paper, the seismic performance of fuel assembly rows is analyzed for historical ground motion records of seismic events in Europe that are compatible with the seismic hazard background of Goesgen NPP, at the frequency of exceedance of 10^-4/a. The benefit of the analysis is twofold. Firstly, it represents an alternative approach to standard fragility analysis, which is based on ground motions matching the UHS. Instead, the present analysis is based on recorded time histories which can be viewed as an actual earthquake scenario at the site. Secondly, the analysis looks at ground motion intensity measures other than the peak ground acceleration, which are considered to be equally or even more relevant for actual damage. Ultimately, these results can lead to more realistic fragility estimates – and hence risk footprint in the PSA – of the FA.