Insufficient Dissolution Reason of Sacrificial Anode in a Nuclear Power Plant

Three years after a coastal nuclear power plant using seawater, most of the sacrificial anodes of the drum filter screen were still insufficiently dissolved and even fell off. Through the analysis of the anti-corrosion design of drum filter screen, the chemical composition and electrochemical performance of sacrificial anode, the reasons for the insufficient dissolution of sacrificial anode were studied. The results showed that there were casting defects inside sacrificial anode, seawater entered the inside of sacrificial anode from defects, and the base material was corroded preferentially and completely dissolved, the sacrificial anode fell off. The electrochemical performance of sacrificial anode did not meet standard regulation, and its low indium content was the root cause of insufficient dissolution.