Effect of organic film on magnetite deposition behavior of alloy 690 steam generator tubes in simulated PWR secondary system

Abstract

The purpose of this study is to elucidate the effect of a film forming amine (FFA) on the magnetite deposition behavior of Alloy 690 tube in the secondary coolant system of pressurized water reactors. By the addition of octadecylamine (ODA), which is a FFA, an organic film with a petal-like form was evenly formed on the surface of the steam generator (SG) tube. Regardless of the addition of ODA, all simulated deposits were verified as magnetite and had a polyhedral or spherical shape. The amount of deposits on the film-formed SG tube was reduced by approximately 58% compared to the deposits on the as-received SG tube. The influence of the film-formed surface of the SG tube is discussed from the point of view of wettability, zeta potentials, and resistance of the electric double layer.

Keywords

• Steam generator tube
• Film forming amine
• Octadecylamine
• Magnetite deposits
• Zeta potential