Success Stories

New AECL technology reaches private sector implementation

AECL has recently submitted a patent for its Composite Angle Profiling Tool (CAPT). This innovative tooling was developed to detect pipe wall thinning in areas in CANDU reactors with severe access limitations (feeder pipes). The technology was first put to use in 2009 and has now been successfully implemented by the private sector. The successful deployment of this innovative AECL technology in the field is a clear example of how AECL helps to support a strong nuclear power sector in Canada.

The Composite Angle Profiling Tool is an ultrasonic testing inspection tool developed by AECL to produce wall thickness maps on feeder pipes and under welds. CAPT is based on technology first developed by AECL as part of a nuclear platform project in support of Wolsong Unit 1 Refurbishment. It was then modified and further developed by AECL as part of an industry-driven Feeder Integrity Joint Project. The first CAPT field trial was performed in 2009 by AECL as a commercial project.

As part of the primary heat transport system, feeders are a crucial component in reactor safety providing coolant to the reactor core. Destructive examination of feeders had revealed highly localized thin regions (blunt flaws) immediately adjacent to hub welds and fitting-to-fitting welds on the outlet feeders only. While blunt flaws are typically near the welds, more generalized thinning was also found at feeder bends beside or away from welds.

“The areas of the reactor that CAPT was designed to inspect are very difficult to access,” explains Hélène Hébert, Research Scientist with the Inspection Monitoring and Dynamics Branch. “Our tool really excels at safely examining those difficult spaces – often with uneven or angled faces where the pipes bend to meet the hub. There are many obstacles, with tight tolerances and high radiation fields and contamination issues further complicating matters.”

Although reactor designs differ, some reactors have as many as five welds to be inspected in as many as 480 feeders. The CAPT tool enables a more efficient job which helps to reduce worker dose and saves both time and money. The results are also far more detailed than competitor products as CAPT uses improved data analysis software (FAATS-COG v3.0) which provides greater simplicity than competitor products, and at lower cost. CAPT also has the ability to help the analyst produce wall thickness maps through weld crowns, Grayloc hub welds and fitting-to-fitting welds. It is also compatible with the instrumentation and software already commonly used in other CANDU feeder inspections.

AECL has now completed the training of a team from the private sector, and in mid-February they successfully undertook a CAPT inspection at an Ontario nuclear generating station. This was the first CAPT inspection not led by AECL; although AECL did have expertise on site should it have been required.

“With this inspection done, the knowledge transfer from AECL to the private sector is complete,” Hébert stated.