Study on Seismic Qualification Test Input for Nuclear Safety Class Valves based on Dynamic Response Characteristics of Pipes

Since nuclear safety class valves may be located in different buildings and floors, the seismic qualification input needs to envelope all possible situations. China’s domestic nuclear power regulations provide the suggested relationship between frequency and acceleration for seismic input, but they do not specify how this was formulated or guide users on how to adapt it. This paper addresses this issue. Through the analysis of the seismic response characteristics of typical pipes, this paper summarizes the amplification characteristics of pipe systems to earthquakes and then provides a theoretical method for determining seismic input. It also offers guiding acceleration and frequency requirements for Generation 3 nuclear power plants. In terms of artificial simulation time history multi-frequency wave method and sinusoidal wave method in the valve seismic qualification commonly used in Generation 3 nuclear power plants, the theoretical method proposed in this paper can explain the differences between engineering practice and domestic regulations, and provide suggestions for problems encountered in qualification tests for adaptation.