Abstract An impact hammer test of the full-scale mock-up of the ITER blanket remote handling system (BRHS) was carried out to validate the results of the seismic analysis of the BRHS which were performed using a finite element (FE) model. As the FE analysis of the BRHS predicted a vertical mode ∼8 Hz, which coincides with a major natural frequency of the vacuum vessel of ITER, evaluating the dynamic response of the BRHS experimentally and measuring the system's damping is indispensable in verifying the structural design of the system. Recent preliminary impact testing on the full-scale mock-up of the BRHS showed that the mock-up has a vertical major natural mode having a natural frequency of ∼7.5 Hz and a damping ratio of 0.5%. Several other major natural modes having frequencies less than 10 Hz were found to have damping ratios ranging from 0.2% to 2%. It was confirmed that the natural major frequencies obtained in the experiments are in agreement with the major frequencies obtained via analysis.