Author Description

Individual specimens of full-length 15.24 mm diameter candu zircaloy-4 fuel sheaths, with three planes of appendages attached by beryllium brazing, were tested in a transient fuel studies visual rig at cge to determine test parameters for subsequent tests of seven-element clusters. the specimens were indirectly heated with internal electric heaters. during the tests the as-received sheath sections between the braze heat-affected zones of the specimens cooled relative to the braze heat-affected regions. tests were done with a variety of specimens and heating techniques to determine the cause of the axial temperature gradients and to find a solution to eliminate them. these tests showed the cge brazing cycle changed the surface emissivity of the heat-affected zones. test heating techniques did not alter the gradients. chemically removing approximately 0.01 mm from the specimen outer surfaces was selected as the best technique to obtain uniform axial temperatures.