Chemistry Commons^™

Humid Air Corrosion Of Carbon Steel And Stainless Steels Under Gamma Radiation: The Role Of Solution Volume And Radiolysis Products, Masoud Zakeri

Electronic Thesis and Dissertation Repository

As nuclear power plants age and their lifetimes are extended, it is critical to be able to accurately assess the long-term integrity of the reactor structural materials. A current investigation into a leak in the End Shield Cooling (ESC) System in Ontario Power Generation’s Pickering Unit 6 reactor has raised a potential issue. The corrosion of the supporting structural materials (carbon steel (CS) and stainless steel (SS)) in the presence of ionizing radiation in small stagnant solutions and humid air conditions therefore needs careful evaluation.

This project investigates the effect of water radiolysis and humid air radiolysis products (H_{2 …}

Effects Of Gamma-Radiation On The Evolution Of Copper Corrosion Dynamics In Deep Geological Repository Solution Environments, Lindsay J. Grandy

Electronic Thesis and Dissertation Repository

The Canadian plan for permanent disposal of used nuclear fuel involves a used fuel container (UFC), a carbon steel vessel with a copper coating to provide the corrosion protection. The corrosion conditions for the copper layer of the UFC are expected to involve small, stagnant water volumes, pH values between 6 and 9, and a continuous flux of γ-radiation emitted from the radionuclides trapped in the fuel matrix. While γ-radiation does not affect the copper metal directly, humid air and water will radiolytically decompose into redox-active and acidic species which will be produced at constant concentrations and can alter the …

Copper Corrosion Dynamics Under Deep Geologic Repository Conditions, Masoumeh Naghizadeh

Electronic Thesis and Dissertation Repository

Canada’s plan for the permanent disposal of spent nuclear fuel involves a multiple-barrier system contained within a deep geologic repository (DGR). The key engineered barrier is the used fuel container (UFC), which is a copper-coated carbon steel vessel. The environments to which the copper coating will be exposed in the DGR are very different from those commonly encountered in copper corrosion studies. The copper (Cu) will be in contact with thin stagnant layers of water, and the corrosion system will be exposed to a continuous flux of γ-radiation. In the presence of γ-radiation, water and humid air decompose to redox-active …

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 …

Gamma-Radiolysis Kinetics Of Liquid, Vapour And Supercritical Water, Nastaran Yousefi

Electronic Thesis and Dissertation Repository

Inadequate understanding of radiation-induced water chemistry under supercritical conditions has been identified as one of the important obstacles in the development of a supercritical water-cooled reactor. Radiolysis of supercritical water generates a variety of redox reactive species, but their persistence in supercritical water is not well understood. This thesis describes the work performed towards addressing this deficiency: (1) the development of a reliable experimental method to determine the concentrations of water radiolysis products, primarily H₂, O₂ and H₂O₂, formed under g-irradiation of sub- and supercritical water (SCW), (2) the expansion of the application …