Evaluation of source terms of fission products in gaseous effluents and recommendations for effluent monitoring of nuclear power plants

The source terms of fission products in the airborne effluents of the CPR1000 and HPR1000 (Hualong One) nuclear power plants (NPPs) in China were estimated for cycles without fuel failure. We used both the operational data for the primary coolants of domestic and foreign NPPs as well as the latest research on reactor source terms for this purpose. The results indicated that the activity concentrations of fission product nuclides in the gaseous effluents were two orders of magnitude lower than the detection limit of laboratory instruments. After comparing the domestic and foreign regulations on gaseous effluent monitoring of NPPs and reviewing the domestic gaseous effluent monitoring practices, recommendations on gaseous effluent monitoring were offered in this paper. This study could provide a technical basis for gaseous effluent management for NPPs and help revise the relevant Chinese regulations and standards in the future. (author)