Session: CS-22-02 Temper Bead Welding Advancements for Repair and Replacement

Paper Number: 107473

107473 - Progress and Advancement of Ambient Temperature Temper Bead Welding in the Nuclear Power Industry 

Ambient temperature temper bead welding is a proven technology that has been crucial for repair of nozzles and branch connections in heavy section pressure vessels and piping in the nuclear power industry. The technique is especially suited for repair welding applications where elevated preheat and post weld heat treatment are impractical, if not impossible. In the nuclear industry ambient temperature temper bead welding has been deployed extensively when systems cannot be drained for radiological or safety reasons. Significant advancements in the temper bead technology and improvements to the ASME code rules have been made since ASME first approved the ambient temperature temper bead welding technology with Case N-638 for machine GTAW in September of 1999.  The current ambient temperature temper bead Case N-888 approved in March of 2020 combines the ambient temper bead rules for SMAW in Case N-839 and Machine GTAW temper bead rules in Case N-638-11.  This paper summarizes the stepwise advancements in technology and changes to the code rules and requirements starting with Case N-638 up to the current Case N-888. For each significant change to the ambient temperature temper bead rules the purpose and reason for the change is presented with key technical basis documents referenced.

Presenting Author: Steven L. McCracken EPRI

Presenting Author Biography: Steve has a BS in Mechanical Engineering from the University of Missouri and an MS in Welding Engineering from The Ohio State University. Steve has worked in the nuclear power industry for over 40 years and has been with EPRI since May 2007 in the Welding & Repair Technology Center in Charlotte, NC. While at EPRI Steve has focused on research associated with Alloy 52 weldability, temper bead welding, and SCC repair and mitigation technologies. Steve is active in the ASME Code Committees in the areas of materials, welding, and repair/replacement activities. Prior to EPRI Steve was the Welding Engineer and ASME R&R Engineer at the Callaway Nuclear plant in Missouri. Before his Engineering career Steve was a certified pipe-fitter welder and worked at the Callaway and Wolf Creek nuclear power plants during construction.

Authors:

Steven L. McCracken EPRI
Shane Findlan Stone and Webster Inc.
Joseph Weicks Entergy