Investigation on Ion Migration in the Secondary Side of Steam Generators Based on Porous Medium Method

Abstract

In the operation of nuclear power systems, leakage in condensers may introduce chloride ions (Cl⁻) and insoluble impurities into the secondary loop, posing corrosion risks to heat transfer components. This study investigates the migration and precipitation behavior of Cl⁻ and other impurities in the secondary side of steam generators using a porous medium-based numerical approach. The model simulates flow and heat transfer characteristics and evaluates distributions of temperature, void fraction, and velocity. The results show that inlet flow velocity, secondary side temperature, and primary side flow significantly affect ion transport and accumulation. Cl⁻ ions tend to accumulate on the hot side of the conical expansion support plate, with a peak concentration of 30.3 ppm. Insoluble impurities are primarily deposited on the flow distribution plate. These findings contribute to a better understanding of impurity behavior in nuclear steam generators, providing insights for improving safety and performance under potential seawater intrusion scenarios.

Keywords: steam generator, ion migration, distribution characteristics, impurity migration