Crack Detection in Nuclear Steam Generator Tubes

Rotary LSPI™ sensor for inspecting steam generator tubing

LSPI™ image of complex cracking in 17 mm (0.669 inch) ID tubing

The problem:

Steam generator tubes, found in commercial nuclear power generating plants, are sometimes subject to internal cracking. Left undetected, this cracking can ultimately lead to failure – causing unexpected shutdowns, expensive repairs and loss of revenue. Inspection of these tubes, already a challenge, is further complicated by the fact that they are located in a radiation environment.

The solution:

LTC's patented laser-scanned penetrant inspection (LSPI™) technology is ideal for crack detection in tubes. LTC has collaborated with iP-TEC AB of Sweden to integrate our LSPI™ sensor technology with their remote penetrant delivery system. The combination of LTC’s LSPI™ sensor technology with iP-TEC’s remote penetrant delivery system enables operators to generate high-resolution and quantitative inspection results from steam generator tubes. This automated fluorescent penetrant inspection system is capable of treating and scanning a tube in a matter of minutes.

Advantages include:

Rapid and quantitative data acquisition

Documentation of inspection results

Remote / automated operation

Near real-time results

Rugged and portable system components

Digital data format

Windows™-based software

Can be combined with other NDT technologies, such as eddy current.

The integrated penetrant delivery module and LSPI™ sensor allow operators to remotely and automatically treat and scan localized areas that are suspected to have crack indications.

The image above shows an example of typical LSPI™ test results obtained from the inner surface of 0.669 inch (17 mm) ID steam generator tubes. This new method of conducting automated fluorescent penetrant inspection (FPI) allows operators to automatically treat and scan a tube in a matter of minutes. Results are provided in a our LaserViewer™ software with quantitative “C-scan” images. Operators can measure feature geometry, print out hard-copy images and archive data for future analysis and comparison.

For more information about laser-scanned FPI and how it works, see our LSPI™ technology page.