Nuclear Power Plant Circulating Water Pipeline

The headers were repaired during planned refueling outages.  Highlights of our work include the following:

• Developed a three-dimensional finite element model of the entire repair area to determine the stresses in the CFRP-lined header
• Prepared drawings, calculations, and specifications, including step-by-step procedures for removing the existing cement mortar lining, preparing the surface, installing CFRP, and curing
• Prepared a failure modes and effects analysis report describing the failure modes of the CFRP-lined steel pipe, the causes and effects of each failure mode, and measures that can be taken to prevent them
• Performed continuous inspections during construction to verify compliance with repair design and specifications
• Conducted tension tests according to ASTM D3039 – Standard Test Method for Tensile Properties of Polymer Matrix Composite Materials on coupons cut from the CFRP test panels prepared during construction
• Completed laboratory testing according to ASTM E2160 – Standard Test Method for Heat of Reaction of Thermally Reactive Materials by Differential Scanning Calorimetry on epoxy samples taken from CFRP liners prior to refilling the pipeline to confirm sufficient degree of cure
• Provided a report summarizing all inspection and testing activities, including inspection of prepared surfaces, mockup testing for bond strength, inspection of preparation and installation of all materials, and post-installation inspection identifying defects and corrective actions as necessary