Efficient global sensitivity analysis of structural vibration for a nuclear reactor system subject to nonstationary loading.

•Non-stationary stochastic loads were applied to a reactor system finite element model.•Model parameters were varied based on variations amongst reactor designs, considering aging phenomena.•Reactor vessel head acceleration response was examined via global sensitivity analysis.•Kriging surrogates were trained by exercising the finite element model through several sampling strategies.•The resultant global sensitivity analysis and surrogate modeling errors were compared.•Efficient methodology enables parsimonious and credible design analysis techniques.