Radiochemistry Commons^™

Galvanic Corrosion Of Carbon Steel-Stainless Steel Welds, Mi Li

Electronic Thesis and Dissertation Repository

A water leak in one of the Canada Deuterium Uranium (CANDU) nuclear reactors could lead to galvanic corrosion between the materials of its supporting structures: carbon steel (CS) and stainless steel (SS). This project investigates the effects of physical and chemical solution parameters on the corrosion of galvanically coupled dissimilar CS-SS welds, with the aim of developing a corrosion dynamics model that can be used to assess the long-term integrity of the CANDU reactor structural materials with confidence. The studied parameters were solution pH, temperature, the presence or absence of γ-radiation and the cathode:anode surface area ratio. Multiple electrochemical techniques …

Corrosion Dynamics Of Carbon Steel In Used Fuel Container Environments, Dan Guo

Electronic Thesis and Dissertation Repository

The current Canadian used nuclear fuel container (UFC) design uses a pressure‑grade carbon steel (CS) vessel with its outer surface coated with a thin layer of copper. One concern regarding the structural integrity of the UFC design is the potential internal corrosion of the CS vessel. Moisture trapped inside a UFC could condense within the gap between the hemispherical head and the cylindrical body of the vessel. The internal UFC environment will be exposed to a continuous flux of ionizing radiation arising from the decay of radionuclides trapped in the used UO₂ fuel matrix.

This thesis research project investigates …

Fundamental Chemistry Related To The Separations And Coordination Of Actinium-225, Thorium-227, And Technetium-99, Jasmine L. Hatcher

Dissertations, Theses, and Capstone Projects

This work explores the fundamental chemistry of actinium, thorium, and technetium in an effort to develop methodologies which help to address complications specific to each of these elements. Developing fundamental knowledge in inorganic chemistry has the power to meaningfully address a number of real world problems. By using simple systems and experiments like following an electron or changing the solvent system, we are able to gain invaluable information which can be used to address major issues.

Actinium-225 (t_½: 9.92 d) is an alpha-emitting radionuclide with nuclear properties well suited for alpha therapy of malignant tumors. The present global …

Electrochemical And Modelling Studies On Simulated Spent Nuclear Fuel Corrosion Under Permanent Waste Disposal Conditions, Nazhen Liu

Electronic Thesis and Dissertation Repository

The safety assessment models for the deep geological disposal of spent nuclear fuel require a fundamental understanding of the corrosion of spent fuel in a failed waste container. The overall research goal of this project is to investigate the corrosion of simulated spent fuel under permanent disposal conditions, using both model simulations and experimental investigations. A model for fuel corrosion has been expanded to determine the relative importance of radiolytic hydrogen and hydrogen from corrosion of the steel vessel in suppressing fuel corrosion. It was shown that, for CANDU (CANada Deuterium Uranium) fuel with moderate in-reactor burnup, only micromolar concentrations …

Direct Dissolution And Electrochemical Investigation Of Cerium And Uranium In Ionic Liquid, Janelle Droessler

UNLV Theses, Dissertations, Professional Papers, and Capstones

The solubility, coordination and speciation of f-elements in ionic liquids (ILs) has been the focus of numerous studies because the purely ionic systems have unique physical properties that can be exploited in comparison to aqueous, organic, or molten salt systems. Ionic liquids are thermally stable, have negligible vapor pressure, and are electrochemically stable at negative potentials that encompass the reduction potential of actinide species. Literature has suggested that the properties of ILs could potentially be utilized in the nuclear fuel cycle for separations and reprocessing. However, the solubility of f-elements in ILs has been significantly lower compared to traditional solvents. …

The Electrochemistry Of Hydrogen Peroxide On Uranium Dioxide And The Modelling Of Used Nuclear Fuel Corrosion Under Permanent Disposal Conditions, Linda Wu

Electronic Thesis and Dissertation Repository

This thesis reports a series of investigations examining the corrosion process of used nuclear fuel under permanent disposal conditions. The motivation of the project is that the safety assessment of deep geological disposal of spent nuclear fuel requires a fundamental understanding of the processes controlling fuel corrosion which could lead to the release of radionuclides to the geosphere from a failed container.

One primary objective of this project was to develop a computational model in order to simulate fuel corrosion under the disposal conditions. A series of simulations based on COMSOL were designed and developed to determine the influence of …

Synthesis, Extraction, Dissolution, And Voltammetry Of F-Species In A Room Temperature Ionic Liquid Solvent, Wendy Jacqueline Pemberton

UNLV Theses, Dissertations, Professional Papers, and Capstones

Room temperature ionic liquids (RTILs) are salts that are liquids from as low as -96 °C to up to 100 °C. RTILs are of high interest in many fields of study because of their negligible vapor pressure, high electrochemical stability, high conductivity, and wide electrochemical windows. These diverse solvents have recently been used in organic synthesis, as extraction solvents, and as electrochemical solvents. It is as a direct result of the multifunctional capabilities of these RTIL solvents that they are examined in this work. The ability to probe the chemistry of lanthanides and actinides is based on the unique properties …

Electrochemical Separation Of Curium And Americium, David W. Hatchett, Kenneth Czerwinski

Separations Campaign (TRP)

The objective of this project is to develop a method for the separation of Am from Cm based on electrochemical techniques. Electrochemical systems that allow the thermodynamics of actinide and lanthanide complexes to be systematically evaluated and tuned will be examined. The influence of complex formation on the ability to selectively isolate a given species electrochemically will be evaluated. Metal-ligand complex formation provides a useful derivation technique to increase solubility in solution environments that favor precipitation. In addition, the thermodynamic properties of a complex relative to the isolated species may be shifted to more suitably measurable electrochemical separation regimes. Electrochemical …