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Papers by David Shoesmith

Journal of The Electrochemical Society, 2019

Journal of The Electrochemical Society

Under some conditions, copper and copper alloys are either immune from corrosion or undergo slow ... more Under some conditions, copper and copper alloys are either immune from corrosion or undergo slow uniform corrosion, generally considered a favourable situation, since predicting the damage incurred by the metal during a period of uniform corrosion is relatively straightforward. However, under conditions leading to surface passivation of Cu, localized corrosion might occur in the presence of aggressive oxidants. Therefore, the susceptibility of Cu to localized corrosion must be considered carefully to avoid unpredictable failures in Cu-based structures. Understanding the pitting probability of Cu is important for various applications, including the use of Cu-coated containers for the permanent disposal of used nuclear fuel. In this study, the pitting probability of Cu in chloride-containing solutions crudely representing the groundwater that might be found in a deep geologic repository (DGR) was investigated using electrochemical techniques and statistical analysis. The probabilities...

Journal of The Electrochemical Society, 2022

The long-term containment plan for Canada’s used nuclear fuel employs copper-coated carbon steel ... more The long-term containment plan for Canada’s used nuclear fuel employs copper-coated carbon steel (CS) containers encased in compacted bentonite clay buffer boxes. In the hypothetical case of a through-coating defect, galvanic interactions between the Cu coating and the CS vessel are dependent on the conditions at the container surface. A zero-resistance ammeter was used to measure the galvanic current between Cu and CS electrodes at various area ratios in the presence of aerated 1 M NaCl and obstructive layers of bentonite slurry. The presence of bentonite resulted in an order of magnitude decrease in the corrosion rate of the steel. As shown by scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis and Raman spectroscopy, the extent of steel corrosion decreased significantly in the presence of bentonite slurry, favouring mild surface etching over oxide growth. Electrochemical impedance spectroscopy (EIS) measurements showed that the total impedance on carbon...

ECS Meeting Abstracts, 2021

Materials and Corrosion, 2020

The strategy for the permanent disposal of high‐level nuclear waste in Canada involves sealing it... more The strategy for the permanent disposal of high‐level nuclear waste in Canada involves sealing it in a copper‐coated steel container and burying it in a deep geologic repository. During the early emplacement period, the container could be exposed to warm humid air, which could result in the condensation of nitric acid, produced by the radiolysis of the humid air, on the copper surface. Previous studies have suggested that both nitrate and oxygen reduction will drive copper corrosion, with the nitrate reduction kinetics being dependent on the concentration of soluble copper(I) produced by the anodic dissolution of copper in the reaction with oxygen. This study focused on determining the kinetics of nitrate and oxygen reduction and elucidating the synergistic relationship between the two processes. This was investigated using corrosion potential and polarization measurements in conjunction with scanning electron microscopy and X‐ray photoelectron spectroscopy. Oxygen reduction was sho...

Journal of Electroanalytical Chemistry and Interfacial Electrochemistry, 1973

Journal of Electroanalytical Chemistry and Interfacial Electrochemistry, 1973

MRS Proceedings, 2006

Scandinavian/Canadian high-level nuclear waste repository conditions are expected to evolve from ... more Scandinavian/Canadian high-level nuclear waste repository conditions are expected to evolve from initially warm and oxic to eventually cool and anoxic. During the warm oxic period, corrosion products will accumulate on the container surface. These deposits could impede the reaction of Cu with aqueous sulphide, the only reaction that could lead to the significant accumulation of additional corrosion damage under the long-term anoxic conditions. The kinetics of reaction of Cu with aqueous sulphide solutions have been studied using electrochemical and surface analytical techniques. Corrosion potential measurements were used to follow the evolution of the surface as oxides/hydroxides were converted to sulphides in the sulphide concentration range 10-5 to 10-3 mol/L. Changes in composition were followed by in-situ Raman spectroscopy. Of critical importance is whether or not a period of preoxidation of a Cu container surface can prevent subsequent reaction of the surface with remotely pro...

MRS Proceedings, 2006

Canada's Nuclear Waste Management Organization has recommended to the Canadian federal govern... more Canada's Nuclear Waste Management Organization has recommended to the Canadian federal government an adaptive phased management approach to the long-term management of used nuclear fuel. This approach includes isolation in a deep geologic repository. In such a repository, the fuel would be sealed inside a carbon steel-lined copper container. To assist the development of performance assessment models studies of fuel behaviour inside a failed waste container are underway. Using an iterative modeling and experimental approach, the important features and processes that determine fuel behaviour have been identified and studied. These features and processes are discussed and the results of studies to elucidate specific mechanisms and determine important parameter values summarized.

Journal of The Electrochemical Society, 2010

ABSTRACT

Journal of The Electrochemical Society, 2007

ABSTRACT The conversion of a film on copper to in aqueous sulfide solutions has been followed usi... more ABSTRACT The conversion of a film on copper to in aqueous sulfide solutions has been followed using a combination of electrochemical techniques and in situ Raman spectroscopy. Oxide films were electrochemically grown in alkaline solutions and their composition and morphology determined using Raman spectroscopy and scanning electron microscopy. Although corrosion potential measurements indicate that the aqueous sulfide solution rapidly penetrates the porous layer, the oxide-to-sulfide reaction appears to proceed chemically at the oxide/solution interface rather than via the galvanic coupling of Cu oxidation to and reduction to Cu. In situ Raman spectroscopy confirms that the sulfide formed is , and cathodic stripping voltammetry shows that the reaction is initially rapid and then proceeds at a constant rate until the conversion is complete. Comparison of the amounts of oxide initially present and sulfide eventually formed demonstrates that the conversion is 100% efficient. These studies are part of a larger project to determine the important corrosion processes on copper high-level nuclear waste containers exposed to anoxic aqueous sulfide containing groundwaters.

Electrochimica Acta, 2011

Corrosion Engineering, Science and Technology, 2011

Canadian Journal of Chemistry, 1978

The electrochemical formation of mercuric oxide on mercury in alkaline solutions is described. Th... more The electrochemical formation of mercuric oxide on mercury in alkaline solutions is described. The reaction was investigated because of its importance as a reference electrode system, and also because it provides a model test of recent theoretical developments. Various derived data are compared to computer simulations of the growth mechanism.

Journal of The Electrochemical Society, 2019

Journal of The Electrochemical Society

Under some conditions, copper and copper alloys are either immune from corrosion or undergo slow ... more Under some conditions, copper and copper alloys are either immune from corrosion or undergo slow uniform corrosion, generally considered a favourable situation, since predicting the damage incurred by the metal during a period of uniform corrosion is relatively straightforward. However, under conditions leading to surface passivation of Cu, localized corrosion might occur in the presence of aggressive oxidants. Therefore, the susceptibility of Cu to localized corrosion must be considered carefully to avoid unpredictable failures in Cu-based structures. Understanding the pitting probability of Cu is important for various applications, including the use of Cu-coated containers for the permanent disposal of used nuclear fuel. In this study, the pitting probability of Cu in chloride-containing solutions crudely representing the groundwater that might be found in a deep geologic repository (DGR) was investigated using electrochemical techniques and statistical analysis. The probabilities...

Journal of The Electrochemical Society, 2022

The long-term containment plan for Canada’s used nuclear fuel employs copper-coated carbon steel ... more The long-term containment plan for Canada’s used nuclear fuel employs copper-coated carbon steel (CS) containers encased in compacted bentonite clay buffer boxes. In the hypothetical case of a through-coating defect, galvanic interactions between the Cu coating and the CS vessel are dependent on the conditions at the container surface. A zero-resistance ammeter was used to measure the galvanic current between Cu and CS electrodes at various area ratios in the presence of aerated 1 M NaCl and obstructive layers of bentonite slurry. The presence of bentonite resulted in an order of magnitude decrease in the corrosion rate of the steel. As shown by scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis and Raman spectroscopy, the extent of steel corrosion decreased significantly in the presence of bentonite slurry, favouring mild surface etching over oxide growth. Electrochemical impedance spectroscopy (EIS) measurements showed that the total impedance on carbon...

ECS Meeting Abstracts, 2021

Materials and Corrosion, 2020

The strategy for the permanent disposal of high‐level nuclear waste in Canada involves sealing it... more The strategy for the permanent disposal of high‐level nuclear waste in Canada involves sealing it in a copper‐coated steel container and burying it in a deep geologic repository. During the early emplacement period, the container could be exposed to warm humid air, which could result in the condensation of nitric acid, produced by the radiolysis of the humid air, on the copper surface. Previous studies have suggested that both nitrate and oxygen reduction will drive copper corrosion, with the nitrate reduction kinetics being dependent on the concentration of soluble copper(I) produced by the anodic dissolution of copper in the reaction with oxygen. This study focused on determining the kinetics of nitrate and oxygen reduction and elucidating the synergistic relationship between the two processes. This was investigated using corrosion potential and polarization measurements in conjunction with scanning electron microscopy and X‐ray photoelectron spectroscopy. Oxygen reduction was sho...

Journal of Electroanalytical Chemistry and Interfacial Electrochemistry, 1973

Journal of Electroanalytical Chemistry and Interfacial Electrochemistry, 1973

MRS Proceedings, 2006

Scandinavian/Canadian high-level nuclear waste repository conditions are expected to evolve from ... more Scandinavian/Canadian high-level nuclear waste repository conditions are expected to evolve from initially warm and oxic to eventually cool and anoxic. During the warm oxic period, corrosion products will accumulate on the container surface. These deposits could impede the reaction of Cu with aqueous sulphide, the only reaction that could lead to the significant accumulation of additional corrosion damage under the long-term anoxic conditions. The kinetics of reaction of Cu with aqueous sulphide solutions have been studied using electrochemical and surface analytical techniques. Corrosion potential measurements were used to follow the evolution of the surface as oxides/hydroxides were converted to sulphides in the sulphide concentration range 10-5 to 10-3 mol/L. Changes in composition were followed by in-situ Raman spectroscopy. Of critical importance is whether or not a period of preoxidation of a Cu container surface can prevent subsequent reaction of the surface with remotely pro...

MRS Proceedings, 2006

Canada's Nuclear Waste Management Organization has recommended to the Canadian federal govern... more Canada's Nuclear Waste Management Organization has recommended to the Canadian federal government an adaptive phased management approach to the long-term management of used nuclear fuel. This approach includes isolation in a deep geologic repository. In such a repository, the fuel would be sealed inside a carbon steel-lined copper container. To assist the development of performance assessment models studies of fuel behaviour inside a failed waste container are underway. Using an iterative modeling and experimental approach, the important features and processes that determine fuel behaviour have been identified and studied. These features and processes are discussed and the results of studies to elucidate specific mechanisms and determine important parameter values summarized.

Journal of The Electrochemical Society, 2010

ABSTRACT

Journal of The Electrochemical Society, 2007

ABSTRACT The conversion of a film on copper to in aqueous sulfide solutions has been followed usi... more ABSTRACT The conversion of a film on copper to in aqueous sulfide solutions has been followed using a combination of electrochemical techniques and in situ Raman spectroscopy. Oxide films were electrochemically grown in alkaline solutions and their composition and morphology determined using Raman spectroscopy and scanning electron microscopy. Although corrosion potential measurements indicate that the aqueous sulfide solution rapidly penetrates the porous layer, the oxide-to-sulfide reaction appears to proceed chemically at the oxide/solution interface rather than via the galvanic coupling of Cu oxidation to and reduction to Cu. In situ Raman spectroscopy confirms that the sulfide formed is , and cathodic stripping voltammetry shows that the reaction is initially rapid and then proceeds at a constant rate until the conversion is complete. Comparison of the amounts of oxide initially present and sulfide eventually formed demonstrates that the conversion is 100% efficient. These studies are part of a larger project to determine the important corrosion processes on copper high-level nuclear waste containers exposed to anoxic aqueous sulfide containing groundwaters.

Electrochimica Acta, 2011

Corrosion Engineering, Science and Technology, 2011

Canadian Journal of Chemistry, 1978

The electrochemical formation of mercuric oxide on mercury in alkaline solutions is described. Th... more The electrochemical formation of mercuric oxide on mercury in alkaline solutions is described. The reaction was investigated because of its importance as a reference electrode system, and also because it provides a model test of recent theoretical developments. Various derived data are compared to computer simulations of the growth mechanism.