A steam generator tube supporting structure limits the steam generator (SG) tube motion that could result from flow induced vibration. The flow induced vibration of SG tubes may sometimes result in fretting wear damage at the tube/support locations. The fretting wear damage predictions could be performed using Archard's equation and wear coefficients which are largely based on experimental data obtained at representative test conditions. The effects of various parameters such as tube materials, support geometry and environmental conditions have been studied. The tube materials tested were Alloy 600 and Alloy 690. Four types of supporting structure were tested using three different levels of tube/support interaction. The tests were performed in pressurized water and saturated steam using equipment that simulates the steam generator environmental conditions and tube/support dynamic interactions. The average values of SG tube/support dynamic parameters such as peak normal force, number of impact, sliding distance per contact, work rate, and impact angle were derived using the WRAP software. The major results of this study are as follows; 1) the wear coefficients of Alloy 600 and Alloy 690 tubes with the 409 stainless steel tube support were shown to be similar. 2) wear coefficients of tubes derived in the steam conditions were greater than those obtained in the pressurized water conditions.
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