Cause Analysis on Leakage of O-ring Seal of Pressure Vessel in a Nuclear Power Station

The O-ring seal of pressure vessel in a nuclear power station leaked.The causes of leakage were analyzed by means of chemical composition analysis, size analysis, macro analysis, hardness test, silver coating quality analysis and micro analysis. The results show that the contact degree between the O-ring and the sealing groove of the top cover was low, and the surface quality of the silver coating was poor, which reduced the sealing reliability and caused the O-ring seal leakage.