Overview of pipe wall thickness management at Tohoku Electric Power

Pipe wall thinning is an aging process that has a significant effect on the safety and safe operation of power plants and its appropriate management is an issue common to all electric power companies. Tohoku Electric Power Co., Inc. has been putting an emphasis on pipe wall thickness management since 2006, when a through-hole possibly due to droplet-impact erosion was found in the vent piping of high-pressure feedwater heater No.2 at Onagawa Nuclear Power Station unit 2. Following this incident, extensive revisions were made to the pipe wall thickness management program and we have been making efforts to improve the efficiency of the management. This report addresses such issues. (author)