Masters Theses

Date of Award

5-2020

Degree Type

Thesis

Degree Name

Master of Science

Major

Nuclear Engineering

Major Professor

Jamie Coble

Committee Members

Christian Petrie, Richard Wood, Xueping Li

Abstract

The nuclear power industry is taking further advancements in the development and testing of advanced fuel compositions, such as accident tolerant fuel. Long-term performance of these newly developed fuels is estimated through physics-based simulation models of irradiation-, temperature-, pressure-, etc.-induced material degradation. model predictions are validated with the measurement and characterization of fuel pin evolution. Linear voltage differential transformers (LVDT) are commonly used to measure fuel pin evolution parameters. However, due to the bulky size and direct touch, LDVTs are often precluded from being used in high performance research reactors. There is crucial need to develop a sensor that can provide real-time reliable and robust material evolution measurements in a highly irradiated environment. A capacitance-based displacement sensor was then simulated and developed at the University of Tennessee to provide a direct measurement of in-pile dimensional change during irradiation. Capacitance-based sensors have been previously investigated for axial dimensional changes in a highly irradiated environments, and have been suggested that such sensors may provide reliable in-pile measurements. Simulated capacitance responses of various creep tube diameters were constructed with simple finite element method models (FEMM), which generate a meshed region over a two-dimensional environment. Due to the simple geometries, it was assumed that the mean capacitance value from the FEMM models were equal to that of a three-dimensional system. Following the simulated models, an Analog Devices 7747 evaluation board was used to provide real-time evaluation of various creep tubes. Diameters of tested/simulated creep tubes were increased by small increments (0.127 millimeter or 0.0254 millimeter) to determine if small dimensional differences could be easily differentiated. Both simulated and experimental capacitance trends showed that capacitance values could easily be distinguished from one another, indicating that the proposed sensor model could provide robust measurements. Troubleshooting in the development of experiment, sensor, and simulated along with potential areas for future research and development are discussed.

Download
Files over 3MB may be slow to open. For best results, right-click and select "save as..."

Share

COinS