A case study on the failure of the electrical panel of nuclear power plants by shaking table tests

The clearest method to evaluate seismic performance is to test the equipment installed in nuclear power plants using shaking table tests. Accordingly, research is conducted to directly evaluate the seismic performance and limit state via shaking table tests on equipment identical to the specifications supplied to nuclear power plants. Specifically, the fragility level test through the actual equipment test, which primarily aims to investigate the equipment's critical acceleration and failure mode, was carried out. This paper summarizes the limit state of the electrical panel for a nuclear power plant observed via the shaking table test through the damage mode using an actual equipment test. The actual equipment test was performed to check the critical acceleration level and analyze the damage mode on the electrical panels to be tested. Results of the shaking table test on the electrical panel confirmed that functional abnormalities were attributed to shaking and impact. It was also found that functional abnormalities and structural failure can occur in earthquakes of similar magnitude. Moreover, structural failure observed mostly involves damage to the door lock, damage to and/or detachment of the internal parts, and damage to connecting members, usually concentrated in the components that support heavy parts.