Radiologically Controlled Line CFRP Repair
Restoring The Safety Reliability and Structural Integrity in a High-Risk Environment
At a nuclear facility, a 6” service water line within a radiological controlled system developed a critical leak, releasing contaminated water onto the facility floor and into adjacent floor drains. The plant chose the in-house contractor to install a carbon fiber system, but the repair failed returning the original problem of managing a leak within RC area. To manage the risk, the plant installed a temporary diversion system until a permanent solution could be executed.
During a scheduled outage, additional complications arose: the system remained active due to multiple drain-downs, and aging valves upstream made isolation impossible. Replacing the line would now require significant modifications beyond the original scope. The only viable path forward was a high-performance, fully engineered composite repair installed by qualified professionals. CFES delivered that solution.
Experience always overcomes challenges
CFES was brought in to engineer design and install a permanent repair solution with a CFES carbon fiber system, addressing both the existing leak and the broader pipe degradation issues while preserving safety and minimizing exposure risk.
How do you stop an active leak after a failed carbon fiber repair?
What’s the solution when system isolation isn’t possible due to aging valves & constant flow?
Inspection and Preparation
CFES implemented a comprehensive approach to inspection and preparation:
Damage Assessment:
Identified pipe wall thinning below 50% of original thickness
Defined upstream and downstream limits until sound pipe was located
Surface Preparation:
Achieved a white metal finish with a 2.5+ mil angular profile
Substrate cleaned and prepped for optimal bond strength
Prior Repair Integration
Existing failed CFRP wrap was left intact to prevent further leakage
Smoothed using epoxy paste to restore cylindrical geometry
New CFRP system was wrapped over the area, encapsulating the failed repair.
Innovative Repair Methods
Advanced materials and techniques were employed to ensure reliable and durable repairs:
FRP System Application:
CFES Style 1210 FG as the first reinforcement
CFES Style 501 used on elbows
CFES Style 1266 used on straight sections
CFES S Epoxy topcoat applied for environmental protection
Fabrication Quality:
Fabrics applied with correct orientation, no wrinkles or air entrapment
Repairs performed by CFES-trained and certified applicators
QA/QC documentation tracked installation and verified adherence to specifications.
Key Outcomes
Permanent Leak Containment
The engineered CFRP system provided a permanent encapsulization eliminating the active leak without requiring pipe replacement.
Safe Integration of Failed Repair
Instead of removing the failed wrap, which risked escalating radioactive exposure, CFES encapsulated it, ensuring containment & continuity.
Structural Restoration
Degraded and corroded pipe sections were encapsulated and restored to original design strength, with the CFRP system extended onto sound pipe for full reinforcement.
Verified Quality and Compliance
All work was completed by trained applicators under a documented QA/QC program, ensuring installation met CFES specifications & nuclear safety standards.
