Ultrasonic Thickness Measurement of Feeder Tubes

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Client’s problem

Thinning in feeder tubes on CANDU reactors has been known for several years. Regular reliable, measurement of the thickness of the tubes is now part of the client’s Outage scope. One of the more difficult areas to inspect, and of great interest, is the area adjacent to the Grayloc weld. The devices typically available for measuring tube thickness could not inspect close enough to the weld to satisfy the client’s needs.

Scope of work

Kinectrics was approached to develop hand tools to measure feeder thickness in the area of the Grayloc weld. The tools were designed in collaboration with our clients to meet their specifications, including ease of use, maintainability in the field, and of course, reliable measurement of thickness.

Solutions

Kinectrics developed two different tools to measure the thickness of feeder tubes. The first tool is the 6-pack encoded outrigger, a hand-held tool that incorporates six ultrasonic transducers and an encoder that records the circumferential position around the feeder. The tool can be run immediately adjacent to the weld, over the weld if the weld cap has been ground off, or anywhere else on a feeder that can be reached by hand. The 6-pack tool is available in two versions, one for 2” feeders and the second for 2.5” feeders.

The second tool is the Grayloc Area Inspection Tool (GAIT), a hand-held tool that can be adapted to fit either 2” or 2.5” feeders. The GAIT attaches directly to the Grayloc hub with a magnetic adaptor that is specific to the size and shape of the Grayloc hub. The tool incorporates eight ultrasonic transducers, oriented to optimize the signal as the probe head moves around the feeder, and an encoder to provide position, similar to the 6-pack.

Client benefits  

The tools have been used in several outages by our clients. The 6-pack has been particularly useful in scanning sections of feeders that are inaccessible with other tools. The GAIT tool has been deployed in two recent outages, providing reliable measurements of over a hundred feeders ahead of schedule.

For more information:

Andrew Grieve, 426.207.6000 x6264, andrew.grieve@kinectrics.com or

John D'Angelo. 416.207.6000 x6193, john.dangelo@kinectrics.com