Electrochemical potential study of metals and alloys in a simulated BWR.

摘要

Selected internal components of Boiling Water Nuclear Reactors (BWRs) are damaged by the Intergranular Stress Corrosion Cracking (IGSCC). The development of a sacrificial anode provides the solution to this problem. The standard electrochemical potentials for different metal specimens were studied by both the open circuit measurement and potentiodynamic scan techniques in pressurized water at 50 ppb, 200 ppb and 8000 ppb dissolved oxygen content and 250°F, 350°F and 550°F temperature. The two approaches show that the electrochemical potentials for these sacrificial anode materials depend strongly on both dissolved O₂ and temperature. The corrosion potentials of the different metal specimens were also determined against stainless steel. Magnesium and Zirconium were found to be the best candidate for use in the BWR. This development requires selecting the metal specimens based on their expected open circuit potential in a BWR environment.