A 10 inch diameter fire protection header located in a northeast nuclear power plant was exhibiting the affects of severe external corrosion. Initial visual inspections revealed that groundwater infiltration, leaking conduit penetrations and steam trace leaks was the cause of the corrosion. Ultrasonic testing was performed at numerous locations along the pipe revealing significant deterioration with some areas at minimum wall thickness and the potential for through wall leaks.
The pipe is part of an active fire protection system vital to plant operation. The pipe is located in a radiogcally controlled area with limited access and workspace. The pipe’s location within the utility tunnel makes welding prohibitive. Pipe thickness well below minimum wall condition rendered the pipe fragile and subject to through wall leaks.
CSI, working with plant operators, were able to identify a way to bypass the fire protection header and keep the fire protection system active. We conducted repair of the piping utilizing CFRP to restore the pipe to original design specifications .