In this study, our objective was to examine a time-history analysis method for simultaneously extracting the dynamic and static seismic responses of nuclear power plant (NPP) equipment. A finite element model of the reactor containment building (RCB) was constructed based on previous research to establish reference structural analysis responses. Additionally, we studied an alternative approach to the methodology presented in the previous regulatory guide, with a focus on time-historical input analysis. To generate a time-history seismic input, we specifically concentrated on creating time histories based on the spectrum-shaped inputs commonly used in the industry. To achieve this, we assessed the compliance of a self-developed MATLAB algorithm for artificial seismic wave generation with regulatory requirements. Subsequently, a seismic analysis was conducted in the time domain using uniform support motion and independent support motion. Furthermore, we proposed a method for generating inputs that reflected these features, and compared and evaluated it against other methods for generating structural analysis responses.