Deposition of Colloidal Magnetite on Stainless Steel in Simulated Steam Generator Conditions—Experiments and Modeling

Abstract

Sludge formation via colloidal magnetite deposition in steam generators is an important phenomenon that significantly influences the thermohydraulic properties and corrosion of structural materials. This paper aims to verify a model of sludge deposition and consolidation with emphasis on its most significant parameters and their experimental estimation. In-situ electrochemical impedance spectroscopic (EIS) measurements are employed for quantitative evaluation of magnetite deposition kinetics on stainless steel in ammonia-ethanolamine (AMETA) secondary coolant at different temperatures. Parameterization of the model by quantitative comparison of the mixed-conduction model (MCM) with experimental data is discussed. Model predictions are compared with literature data from laboratory experiments and plant operation. Conclusions are drawn about the applicability of the model for quantitative assessment of sludge deposition and consolidation rates.

Keywords

• sludge formation and consolidation
• particulate iron oxide
• construction material
• secondary power plant loop
• electrochemical impedance spectroscopy
• kinetic model