Reduction Method for the Main Piping Vibration in Nuclear Power Plant

摘要

Recently, various types of piping system have been installed in the nuclear power plants. For the safe operation of the plants, vibration controls of the piping system are one of the important problems. Vibration of the piping system can be usually controlled by modifying the dynamic characteristics or by reducing the excitation forces on the piping system. Modification of the dynamic characteristics of the piping system can be made by increasing the fixed points of the piping system. However, this can give damage to the fixed points and make cracks in the piping systems because thermal expansion and contraction of the piping system are too much suppressed. Reduction method of the excitation forces have also some problems, such as difficulties in the prediction of vibration decrease, and consideration of both acoustic and vibration fields. Hence, in this study, a method of vibration reduction using P-SVD (piping-viscous damper) is proposed and estimations of the method are carried out though field applications and vibration measurements.