Seismic analysis using Floor Response Spectra (FRS) plays a critical role in assessing the performance of Structure, Systems and Components (SSCs) located at different floors in nuclear facility structures. Presently, a standard 700 MWe PHWR nuclear reactor design is being adopted in fleet mode at multiple sites in India. Hence the conventional approach of FRS generation will require the entire analysis process to be repeated with different site specific seismic inputs for different NPP sites. The entire process is computationally cumbersome and time consuming. Thus, a computationally efficient frequency domain Transfer Function Method (TFM) based approach has been studied and developed which utilizes complex frequency transfer functions generated from the nodal response of conventional modal time history analysis. The frequency domain transfer functions, generated from the nodal response of conventional modal time history analysis, are then used to generate Floor response Spectra. The generated FRS is required for seismic design and analysis of Structure, Systems and Components located on different floors in nuclear facility structures for the expeditious completion of design and analysis activity. This paper aims to provide a comprehensive analysis to demonstrate the performance of TFM in comparison to the conventional method used for FRS generation for nuclear structures.