Abnormal Reasons of Cathodic Protection System of a Debris Filter

Corrosion was found on the out surface of a debris filter which was protected by an sacrificial anode cathodic protection system in a nuclear power plant in China. After checking the whole system, it is found that the poor connections between the anode and the filter as well as the cylinder and the filter were the main reasons causing the failure of cathodic protection. Improvement measures, such as adding extra conductive pieces and measuring the conductivity after system overhaul were proposed.