Westinghouse Electric Co. subsidiary PCI Energy services, LLC (PCI) has recently completed emergent repairs of steam generator bowl drain welds for Wolf Creek Nuclear Operating Corp. (WCNOC) at Wolf Creek Generating station (Wolf Creek). Westinghouse worked with WCNOC to repair Alloy 82/182 cracking in steam generator bowl drain welds discovered during Wolf Creek’s most recent refueling outage. Along with developing the tooling and repair processes, PCI also had to address several machining challenges to complete the repair. Machining was performed dry to avoid potential contamination of the bowl shell, which resulted in longer machining times than originally planned and required additional effort to change out and sharpen the tooling. Additionally, each steam generator had a unique as-found configuration for the drain fitting to steam generator bowl weld, and this further contributed to the machining difficulty. Welding for the project was performed with preheat and the weld deposit depth was limited to satisfy the conditions for a Post weld heat treat exemption for P1 material. The welding phase of the work was completed ahead of schedule, recovering much of the time lost during the difficult machining phase.
