Modeling of Cooling-Water Inleakage Effects in PWR Steam Generators

摘要

Analytical models of solution chemistry in local regions of PWR steam generators with condenser inleakage of seawater, brackish water, cooling tower water, and fresh water have been developed. Acidic solutions are expected in crevices at other than fresh water sites; caustic solutions are expected at fresh water sites. While silica input associated with condenser inleakage had a negligible effect on crevice chemistry for the cases considered, silica input to the steam generators from other sources can be sufficiently larger to increase crevice acidity at seawater sites during condenser inleakage at steady state blowdown chloride concentrations of 50 to 200 ppB. Modeling results, in conjunction with corrosion estimates as a function of pH, can be employed to develop preliminary estimates of the effect of blowdown water quality on denting at operating plants.