Statistical and theoretical analysis of iodine spiking phenomena during steam generator tube rupture

Iodine spiking phenomena has long been the focal point in the design and review of nuclear power plants. This paper implements a statistical and theoretical analysis of iodine spiking phenomena during Steam Generator Tube Rupture (SGTR) events to enhance our understanding of iodine spiking phenomena, ensuring that analyses are aligned with current plant operations and theoretical models. In contrast to previous literatures, this paper proposes an amended iodine spiking model based on the statistical method which is combined with the practice of safety analysis. Additionally, a concurrent iodine spike initiated by the SGTR event is calculated using the theoretical model. Both the statistical analysis and the theoretical calculation results indicate that the current treatment of iodine spiking in regulatory is indeed quite conservative. Combining both methods, this paper recommends an envelope value for the iodine spiking factor and provides a fitting formula considering the applicability across different PWRs.