## 5 Conclusions  
This study aimed to directly compare the seismic behavior characteristics of electrical cabinets installed in NPPs through experimental and numerical methods to identify potential discrepancies. An electrical cabinet model was designed based on the dynamic characteristics of electrical equipment used in Korean-type NPPs, as informed by field surveys. A specimen was fabricated for shaking table tests. The shaking table testing included a resonant frequency search test and a limit state seismic simulation test, conducted under simultaneous tri-axial excitation. The input seismic motion was incrementally increased until structural damage to the specimen occurred. A numerical model was constructed, employing a fixed support to simulate the anchorage boundary conditions, a common practice in numerical analysis. The numerical model's validity was verified using the resonant frequency search test results. Seismic response analysis was performed using the same input seismic motion as the limit state seismic simulation test. The amplification of acceleration response from both the experimental and numerical results were then analyzed to identify and compare differences in seismic behavior characteristics. Figure 24: Percentage difference of FRS amplification ratio in A4: (**a**) average over the frequency range; (**b**) peak over the frequency range; (**c**) ZPA. The failure of the electrical cabinet model observed during the shaking table test was attributed to the fracture of the anchor bolts. As the input seismic motion increased, impact responses on the cabinet were observed, primarily due to the influence of local modes and the nonlinear behavior of the anchorage. These effects amplified the acceleration response and heightened the likelihood of anchor bolt failure. In actual practice, measures can be taken to prevent failure, such as increasing the design margin by welding the foundation and anchors or adding post-installed anchors. Therefore, it was concluded that reinforcing the support, such as by increasing the number of anchor bolts and enhancing the flexibility of the cabinet's base frame, is important to mitigate the impact responses acting on the electrical cabinet. RMS and RMQ values were calculated from the acceleration response time histories to quantitatively assess the seismic behavior characteristics. At EQ1, the acceleration responses from the experimental and numerical results demonstrated generally good agreement. However, at EQ3, where anchor bolt damage was observed, the experimental results revealed a significantly amplified acceleration response. The discrepancies between experimental and numerical results reached up to 49.95% and 58.81% in the horizontal direction for RMS and RMQ, respectively. In the vertical direction, the maximum discrepancy was 87.24%, with RMQ reflecting greater variation than RMS. Similarly, RRMQ was consistently evaluated to be greater than RRMS, confirming its ability to capture the effects of nonlinearity and impulsive characteristics. The seismic behavior characteristics were analyzed and compared by deriving the FRS from the acceleration response time histories. In the low-frequency range, the FRS obtained from the experimental and numerical results exhibited good agreement. However, as the input seismic motion increased, the FRS from the experimental results exhibited greater linear amplification than that from the numerical results across all three directions in the resonant frequency range. Notably, unlike the horizontal directions, where acceleration responses were uniformly amplified within the resonant frequency range, the vertical direction at EQ3 yielded a sharp amplification in the high-frequency range. Moreover, the amplification trend in this range increased with frequency. To quantify the FRS amplification, average and peak values, along with the ZPA, were defined for three frequency ranges: 1-10 Hz, 10-20 Hz, and 20-50 Hz.