Technical Basis and SCC Growth Rate Data to Develop an SCC Disposition Curve for Alloy 82 in BWR Environments
Alloy 82 weld metal shows higher Stress Corrosion Cracking (SCC) resistance in BWR environments than Alloys 182 and 132. To define the relative factor of improvement in SCC resistance and its impact on plant management properly, it is appropriate to establish a SCC growth rate disposition curve for Alloy 82 in BWR environments. In this study, several factors that influence SCC growth behavior of Alloy 82 are evaluated based on the latest Crack Growth Rate (CGR) data collected in Japan BWR Owners Group projects. The goal is to provide a technical basis on which the validity of the data will be evaluated prior to proposing a new disposition curve. The factors evaluated include effects of type of Alloy 82 weld, specimen size, post weld heat treatment (PWHT) and sulfate addition on SCC growth rate.
KeywordsStress corrosion cracking Ni base alloy BWR Crack growth rate Disposition curve Weld type Size effect
GTAW data were collected in a co-operative research program between Japan BWR Owners Group (The Chugoku Electric Power Co., Tohoku Electric Power Co., Tokyo Electric Power Company Holdings, Chubu Electric Power Co., Hokuriku Electric Power Company, The Japan Atomic Power Company, Electric Power Development Co., Toshiba Corporation and Hitachi-GE Nuclear Energy. Some of the MIG/SAW tests were performed at the GE Global Research Center. Those valuable data and many discussions are gratefully acknowledged.
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