Aluminum alloy corrosion and precipitation in high-temperature flow loop simulating environment after loss-of-coolant accidents

The aluminum (Al) alloy corrosion and precipitation tests were carried out in a high-temperature flow loop under different hypothesized post-LOCA chemistry conditions. The effect of the temperature, pH, flow rate and presence of other potential ions on Al corrosion was studied. The Al hydroxide phase transition from less-stable forms to thermodynamically stable forms during isothermal stage preferentially occurred in NaTB-buffered solution. The presence of Zn in solution could effectively inhibit Al release. The solution pH has a strong influence on Al corrosion and the volume of formed precipitate. A kinetic equation was developed to describe Al loss as a function of mass transfer coefficient and solution pH, the effect of OH concentration on Al corrosion was more pronounced than the rate of mass transfer. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

The study investigated the factors affecting aluminum alloy corrosion and precipitation in a high-temperature flow loop under different post-LOCA chemistry conditions, including temperature, pH, flow rate, and presence of other ions. It was found that the solution pH strongly influences aluminum corrosion and the volume of formed precipitate. Additionally, a kinetic equation was developed to describe aluminum loss as a function of mass transfer coefficient and solution pH, highlighting the significant influence of OH concentration on aluminum corrosion.