Analysis and Solutions for Effect of Change of Seismic Acceleration on Valve Qualification

The envelope seismic acceleration is normally used in the seismic requirements of valve design in nuclear power plants. The envelope seismic acceleration in the present design is increased for the change of the site condition or design requirements, which will change the cover scope of the parent valves which has been already qualified. The principle requirements on the analysis and tests for different suppliers are determined based on the engineering practice, codes and standards. The detail input parameters for the different seismic test methods are also provided based on the principle requirements in the code.