Evaluation of amine type inhibitors as potential crevice-buffering agents

This paper describes the results of a research effort conducted to evaluate the suitability of some selected amines as potential crevice buffering agents for PWR steam generator (SG) applications. Five commercially available amines were studied during this research. The investigation involved (1) the hydrolysis of these commercially available amines, including their kinetics of decomposition in simulated steam generator bulk water at 290 degrees C, and (2) their thermal stability in a simulated crevice environment. The study showed that although the high molecular weight amines undergo hydrothermal decomposition, they have a better buffering capacity than their low molecular weight counterparts at 290 degrees C. The amines provide effective crevice solution by as much as 2.84 to 4.24 units. It was concluded that polyamines provide environment at 290 degrees C, while morpholine remains the best low molecular weight amine investigated. However, the volatility of the amines was not considered in this work. Volatility data would be needed prior to an in-plant testing to ensure that the amines can concentrate in SG crevices