New radiolysis-driven matrix dissolution operational model based on stationary UO2 voltametric experiments. (1st May 2022)

• Record Type: Journal Article
• Authors: Radwan, J.; Ly, J.; Hainos, D.
• Is Part Of: Corrosion science. Volume 199(2022)
• Publication Date: 2022-05-01
• Subjects: A. Uranium dioxide -- B. Voltammetry -- B. Electrochemical calculation -- B. Modelling studies -- C. Anodic dissolution; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2022.110158
• Languages: English
• ISSNs: 0010-938X

Abstract

Abstract: In the framework of research on direct deep disposal of spent nuclear fuel, a new α radiolysis-driven matrix dissolution model is proposed. This model is based on an experimental stationary voltametric curve established using a UO2 rotating disk electrode in a neutral pH non-complexing solution under reducing conditions. Kinetic and chemical speciation calculations give access to the equilibrium redox potential of a simulated Callovo-Oxfordian pore water solution containing α-radiolysis products, which is used in the experimentally obtained current-potential relationship to estimate the oxidative dissolution rate. Comparison of model results with literature data show good agreement with previously established α−activity threshold values. Highlights: α radiolysis-driven spent nuclear fuel matrix dissolution model. Uranium dioxide anodic dissolution. Stationary electrochemical behavior of a UO2. Discontinuous sequential acquisition mode of voltammetric curves. Steady-state radiolysis products inventory. Electrochemical potential at the UO2 /solution interface.