QUALITATIVE CORROSION MONITORING BY ONLINE ION CHROMATOGRAPHY

The corrosion mechanism for secondary side systems of pressurized water reactors has always been difficult to monitor and quantify. Ion chromatography may be the method to evaluate the corrosion phenomena using on-line systems. Two separate ion chromatography methods have been developed to monitor manganese, a component of carbon steel and stainless steel used in secondary system piping. The first method employs step gradient cation-exchange separation with chemically suppressed conductometric detection. The second method employs traditional transition metal analysis using an analytical column followed by post-column reagent addition and mixing with visible detection at 520 nm. The presence of manganese was verified using corrosion product monitors. Each monitor has a 0.45-mu-m particulate filter followed by three cation-exchange membrane filters for the determination of soluble metallic species. Atomic absorption spectrophotometry was employed to analyze the processed filters. Results for the corrosion monitors and the ion chromatography methods were compared to attempt validation of all methods and to establish practical methods for on-line corrosion monitoring.