Abstract
Spent Advanced Gas-Cooled Reactor (AGR) fuel is interim stored in cooling ponds, and the fuel cladding may suffer from Stress Corrosion Cracking (SCC) due to the combination of the Radiation-Induced Segregation (RIS) and the corrosive environment in the pond. This thesis presents a better understanding of SCC from different aspects of the phenomenon by using a thermally sensitised surrogate material. A new Small Punch Test (SPT) setup was developed that can accelerate the initiation of SCC by introducing a corrosive environment, and some SCCs were observed on the surrogate material after a few days of exposure. Digital Image Correlation (DIC) was performed on the sample with SCC, and several patterns for a corrosiveenvironment were compared. As DIC can only be used to monitor the cracks on the sample surface, an experiment was conducted by implementing X-ray Computed Tomography (XCT). An in-situ corrosion tensile experiment was performed at a synchrotron beamline, and the propagation of SCC was observed in real-time. To understand the relationship between thermal sensitisation and different grain boundary properties, a volume was reconstructed from serial-sectioned Electron Backscatter Diffraction (EBSD) maps from a thermally sensitised 304 stainless steel, and the remaining material was mapped by Energy-Dispersive X-ray Spectroscopy (EDS).
| Date of Award | 18 Jun 2024 |
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| Original language | English |
| Awarding Institution |
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| Sponsors | National Nuclear Laboratory |
| Supervisor | Ronald Clark (Supervisor), Matthew J Peel (Supervisor) & Mahmoud Mostafavi (Supervisor) |