An improved model for the corrosion of used nuclear fuel inside a failed waste container under permanent disposal conditions

• Published in: Corrosion science Vol. 84; pp. 85 - 95
• Main Authors: Wu, Linda, Qin, Zack, Shoesmith, David W.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01-07-2014; Elsevier
• Subjects: A. Carbon steel; Applied sciences; B. Modelling studies; C. Anodic dissolution; C. Interfaces; Corrosion; Corrosion environments; Exact sciences and technology; Metals. Metallurgy; A. Carbon steel; C. Interfaces; B. Modelling studies; C. Anodic dissolution; Radioactive waste; Electrochemical corrosion; Nuclear fuel; Waste disposal; Modeling; Container; Storage; Anodic dissolution; Carbon steel; Application; Interface
• ISSN: 0010-938X; 1879-0496
• DOI: 10.1016/j.corsci.2014.03.019

[Display omitted]
•The corrosion of spent nuclear fuel in a failed waste container is modelled.•Alpha-radiolysis process is simulated using a full reaction set.•Corrosion of UO2 is largely influenced by steel corrosion products, Fe2+ and H2.•H2 concentrations required to completely suppress fuel corrosion are calculated.•Influences of burnup and fuel age are examined.
An improved model for nuclear fuel corrosion inside a failed waste container has been developed. The model considers the influence of the α-radiolysis products using a full radiolytic reaction set, and demonstrates that H2O2 is the dominant oxidant. Corrosion of the fuel is modelled considering both the direct oxidation of UO2 by H2O2 and the galvanically-coupled oxidation by H2O2 reduction on noble metal (ε) particles. Corrosion has been found to be very sensitive to the corrosion products of steel container, Fe2+ and H2. The surface coverage of ε-particles can significantly influence the dissolution rate.