Abstract: AP1000 unit of Sanmen nuclear power plant is the third-generation nuclear power unit. In order to reduce the unit radiation level and occupational exposure dose, the design of radiation protection has adopted many measures, such as adding zinc of primary, operating at higher pH value, shutdown oxidation operation, steam generator primary water chamber electropolishing, optimizing equipment maintenance, optimizing shielding design, wireless dose monitoring, etc. This paper introduces the radiation level and occupational radiation dose data of AP1000 units of Sanmen nuclear power plant during operation and overhaul, and compared with the relevant data of domestic CPR1000 units, to analyse the radiation protection design of AP1000 units. And giving the suggestions on radiation protection operation management and technical improvement of AP1000 units of Sanmen nuclear power plant.

Key words: Sanmen nuclear power plant, AP1000, radiation protection, occupational exposure, dose