Study on Methodology for Quantification of Radioactive Discharges and Limits for Pressurized Water Reactor HPR1000 Based on Operating Experience

Abstract

For a nuclear power plant, the radioactive gaseous and liquid discharges are the main contributor to radiation exposure to the member of public and non-human biota during normal operation, which hence need to be quantified and to support the environmental impact assessment. When applying the traditional theoretical methodology, due to various and complex mechanisms involved in radioactive gaseous and liquid effluent streams, a number of assumptions need to be made to support the theoretical modeling. The combination of these assumptions can easily lead to overestimate or underestimate of the radioactive discharges and limits and may not represent the actual performance of the plants. As such, to obtain predicted discharges and limits closer to the future actual performance of the plant, it is meaningful and necessary to develop a methodology based on operating experience. This paper has studied and developed a systematic methodology based on operating experience for quantification of radioactive discharges and limits for the 3rd generation pressurized water reactor HPR1000 during normal operation, taking into account the differences on design features and operation management between the HPR1000 and the operating units, the fluctuations due to the variations of plant and system operation parameters and the potential influences from expected events within the normal operation range. This methodology has been successfully applied to HPR1000 and the results have been verified reasonable and appropriate by comparing with the operating experience data from comparable international PWRs. This methodology has been applied to HPR1000 successfully for Generic Design Assessment (GDA) in the UK and the European Utility Requirements for LWR Nuclear Power Plants (EUR) and can also be widely applied for other PWRs with slight adjustment.