Model of eddy current based pressure tube to calandria tube gap measurement

A finite element method (FEM) model was used to simulate the electromagnetic response of a transmit-receive coil pair in the presence of two parallel plates separated by a gap. The work is towards developing a model of eddy current based pressure tube to calandria tube gap measurement in CANDU ^registered nuclear reactors. The FEM model was used to characterize the effect of variations in probe liftoff, conductor resistivity, plate wall thickness and plate-to-plate gap. The model was compared with laboratory measurements performed on a variety of nonferromagnetic conducting plates. Good qualitative agreement between the FEM model and experimental data was observed across a large range of resistivity (1.72 to 174 μΩ.cm), conductor wall thickness (1.1 to 4.85 mm), and plate gap (0 to 12.9 mm) at an excitation frequency of 1.9 kHz. The model is a first step in modelling eddy current response to variations in pressure tube to calandria tube gap.