Repair of 2B high pressure feedwater heat at the Tri-State G&T Craig Generating Station, Craig, Colorado

This technical paper provides a summary of the Craig Station 2B high pressure feedwater repair project completed in November of 1993. After experiencing several forced outages on Craig Station Unit 2 from 2B feedwater heater leaks, Tri-State G&T initiated a capital project to replace the feedwater heater. In addition to complete replacement, Tri-State G&T investigated state-of-the-art repair methods developed under EPRI funded projects. As an alternative to immediate replacement, Tri-State G&T proposed a different repair strategy than used previously. The proposed alternative repair strategy was approved by Tri-State G&T management in July of 1993, the new repair strategy was completed with 6.9% of the tubes plugged and has resulted in reliable service to date with zero tube leaks. The capital project to replace the 2B feedwater heater has been canceled. The purpose of this technical paper is to summarize the technical resources, methods and procedures used to mitigate the damage mechanism and extend the life of the 2B feedwater heater.