Experimental Determination of Residual Stresses in Roll Expanded Joints in CANDURTM Nuclear Reactors

This thesis describes work undertaken to further the understanding of mechanically roll expanded joints in CANDURTM nuclear reactor fuel channels. The residual stresses developed in the joints were investigated through experimental strain measurement during dismantling of joints of 6 and 10 mm walled tubes rolled over a range of wall reductions. Stresses in the rolled joint were calculated from the measured strains using the crack compliance method. A secondary objective was to evaluate the suitability of the crack compliance technique to predict stresses in rolled joints.;The wall thickness was found to have a larger effect on the stress state of the tube than did the amount of wall reduction. The crack compliance technique was found to be a useful tool to determine the residual stress distribution of tubes in mechanical roll expanded joints however the complexity of the technique prohibits application to many common problems.