Critical Spot Repairs of 30- and 90-inch Circulating Water System Piping
Circulating Water (CW) systems are critical to maintaining operability at nuclear power generating stations. If not properly inspected and maintained, there is a risk of station down powers or a forced outage.
A recent example is a US nuclear power plant that experienced a leak in a pipe that led to online maintenance activities, repairs and increased focus on the CW system. At this station, the CW system includes approximately 2,500 linear feet of 30- to 90-inch steel piping near the end of its service life.
The leak was a 12-inch diameter hole that developed within a 30-inch pipeline that was part of the CW system. The leak led to ongoing flooding of an intake basin, causing a need to monitor and pump the basin periodically until the next refueling outage.
During the refueling outage, the hole in the 30-inch pipeline was repaired along with proactively addressing other areas of identified corrosion within four (4) adjacent 90-inch pipelines. The total length of repairs was approximately 60 linear feet.
When evaluating the repairs to be completed, the station had a limited number of options. STRUCTURAL TECHNOLOGIES’ V-Wrap™ carbon fiber-reinforced polymer (CFRP) system was selected because it could deliver a fully structural upgrade to the areas of pipelines affected by corrosion damage and could be implemented during the refueling outage without impacting the schedule.
V-Wrap™ CFRP was ideal to address the spot repairs because it can be installed both internally and externally on the pipelines and is a 100% trenchless system requiring no excavation to complete installation.
STRUCTURAL safely and successfully completed the V-Wrap™ repairs during a planned 9-day working window within the refueling outage schedule. From initial technical support to materials selection, design, installation and quality control, STRUCTURAL TECHNOLOGIES and STRUCTURAL provided turnkey service to assist this nuclear station in addressing its emergent pipeline repair needs.