Nuclear Facility Cooling Water Pipe Rehabilitation
After many spot repairs to remediate leaking issues that were becoming structural concerns, a client at a nuclear facility in North Carolina determined that it was necessary to structurally strengthen the 84-inch diameter discharge headers on four 84-inch diameter pipelines.
Fyfe's Tyfo® FRP system was installed by Fibrwrap Construction during an outage in 2013 to provide standalone rehabilitation on two circulating cooling discharge header pipes. The scope of work included removal of the cement mortar liner so that the fiber wrap could achieve a structural bond with the steel substrate. Chlorides were removed from the steel pipe walls by means of blasting. A chemical treatment was also applied prior to bonding to prep the surface of the pipe. Finally, the Tyfo® Fibrwrap® system was applied in the longitudinal and hoop direction, as dictated by the structural design, which was completed using finite element analysis.
The fiber wrap design was standalone throughout the straight pipe segments and designed as a composite section at the bends and at the supports. This allowed for the remaining steel section to provide the stiffness required in resisting thrust forces at those locations. Once the fiber installation was completed, compression rings were applied at the fiber terminations for both improved detailing and to prevent shear slipping due to longitudinal forces.