Corrosion Mechanism and Electrochemical Reactions on Alloy 690 in Simulated Primary Coolant of Water–Water Energy Reactors-Reference-Cited by-同舟云学术

Corrosion Mechanism and Electrochemical Reactions on Alloy 690 in Simulated Primary Coolant of Water–Water Energy Reactors

Published:2024-04-17 Issue:8 Volume:17 Page:1846
ISSN:1996-1944
Container-title:Materials
language:en
Short-container-title:Materials

Author:

Bojinov Martin¹^ORCID,Betova Iva²,Karastoyanov Vasil¹

Affiliation:

1. Department of Physical Chemistry, University of Chemical Technology and Metallurgy, 1756 Sofia, Bulgaria

2. Institute of Electrochemistry and Energy Systems, Bulgarian Academy of Sciences, 1113 Sofia, Bulgaria

Abstract

During the power operation of the primary loop of a water cooled–water moderated energy reactor (WWER), the water chemistry evolves from a high-boron high-potassium composition to significantly lower concentrations of both constituents at the end of a campaign, and the Li concentration reaches ca. 0.7–0.9 ppm. In the present paper, the effect of primary water chemistry evolution during operation on the corrosion rate and conduction mechanism of oxides on Alloy 690 is studied by in situ impedance spectroscopy at 300 °C/9 MPa during 1-week exposures in an autoclave connected to a re-circulation loop. At the end of exposure, the samples were anodically polarized at potentials −0.8 to −0.1 V vs. SHE to evaluate the stability of the passive oxide. Simultaneously exposed samples of Alloy 690 were subsequently analyzed by XPS to estimate the thickness and in-depth composition of oxides. Impedance data were quantitatively interpreted using the mixed-conduction model (MCM) for oxide films. The effect of water chemistry evolution on the corrosion rate and conduction mechanism in the oxide on Alloy 690 in a primary coolant is discussed based on the obtained parameters.

Funder

the European Union-NextGenerationEU

the National Scientific Infrastructure “Energy Storage and Hydrogen Energy”

Publisher

MDPI AG

Link

https://www.mdpi.com/1996-1944/17/8/1846/pdf

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