Analysis and Management of Accelerated Aging of Relay in NPPs

This paper reveals the main factors of accelerated the aging of relay through statistical analysis of aging and failure data of intermediate relay and output relay for MV distribution board in Daya Bay nuclear power plant and Ling'ao nuclear power plant.The factors of accelerating relay aging are operation context including humidity,temperature,vibration impact,and etc.,and aging mechanism including oxidation corrosion,mechanical wear,electrical wear,organic gas corrosion,insulation aging,electromagnetic interference,and etc.The suggested measures are the classified management,relay replacement,periodic check,and periodic replacement or maintenance.