Abstract: This paper briefly introduces the controlled area access monitoring system (KZC) and its radiation protection management in multi-reactor nuclear power plant, in which the former KZC systems were operated separately in different reactor units. The related issues regarding to achieve one unified KZC management system are also discussed, such as personnel certification to controlled area, individual monitoring, radiation contamination monitoring and its control, etc. In order to manage two separate KZC systems of four reactor units as one in corporate monitoring system, a technical upgrade project of KZC systems was launched in Qinshan-II nuclear power plant. The problems occurred during the technical upgrading and their resolutions are presented in this paper.

Key words: nuclear power plant, multi-reactor, radiation controlled area access monitoring system, technical upgrade