Abstract: Both units of Haiyang Nuclear Power Plant(NPP)Phase I have been equipped with AP1000 technology designed by Westinghouse of the United States. The radiation protection design was based on the priority of using advanced and mature technology. In order to reduce the radiation level of reactor unit and the occupational exposure dose to the staff, a lot of optimization design technology have been used: such as adopting the passive safety system to reduce the amount of equipment; integrated top head design of reactor pressure vessel; the maintenance-free main shield pump; steam generator primary circuit water chamber which adopted electrolytic polishing technology; spent fuel transport channel using of blocking water sac to improve equipment reliability; in order to reduce the maintenance workload. The main optimization measures adopted in the radiation protection design and the protection effect obtained by these measures were introduced, through comparison and analysis with typical data of domestic operating nuclear power plants. These measures can be used for reference for the optimization of radiation protection design in subsequent Phases of Haiyang NPP project, as well as for other peers.

Key words: radiation protection, design optimization, protection effect