Defense Date
2024
Document Type
Thesis
Degree Name
Master of Science
Department
Mechanical and Nuclear Engineering
First Advisor
Braden Goddard
Second Advisor
Reza Mohammadi
Abstract
Chromium-coated Zircaloy-4 cladding represents a novel solution for creating nuclear cladding that has passive safety features. This and related developments aimed at improving nuclear safety are broadly categorized as accident-tolerant fuel and cladding. However, implementing this material presents practical challenges such as the vulnerability that cladding has to surface damage such as fretting wear. This research aims to determine if the pre-existing technique of X-ray fluorescence analysis is applicable for detecting these defects on the surface of the cladding. This was done by developing Monte Carlo N-Particle Transport models of a handheld device, the XL-5, alongside experimental measurements using this equipment. The model was used to simulate a 100 μm deep axial scratch on the cladding surface and determine if this leads to a statistically significant change in photopeak counts (defined as >3σ). The results of the verified model did indicate this level of certainty in the deviation, but experimental measurements performed using the XL-5 were less favorable. The chromium photopeak was effectively unchanged, with a change in photopeak counts of -10 (3σ = 96.3). The zirconium photopeaks showed better results, however they do not meet the threshold for statistical significance that was defined with a change in counts of 273.4 (3σ = 377.7). This indicates that zirconium deviations may be viable for detecting a surface defect of 100 μm deep in theory, but lack the reliability needed to be used in practice due to a lack of certainty. Notable concessions would need to be made to remedy this, such as increasing the detection time significantly.
Rights
© James T. Cahill
Is Part Of
VCU University Archives
Is Part Of
VCU Theses and Dissertations
Date of Submission
8-22-2024
Included in
Computational Engineering Commons, Mechanical Engineering Commons, Nuclear Engineering Commons