Steam Generator Acoustic NDE

Some preliminary results from the steam generator acoustic non-destruction evaluation.*  In the below charts, the difference between the original pipe and that pipe with the noted defects are plotted.

Crack Defect

Hole Defect

We have proven that there is significant difference in the frequency response, and that a hole causes a noisy spectrum than a crack. The axial crack was quite long; it was a hack saw cut into the pipe, and for a real steam generator if you had a 5/64" hole in your steam generator there would be a huge problem - radioactive water would be mixing with the turbine steam.

*The idea is to detect defects in a steam generator by essential vibrating the entire structure. The principle is that if you ding a pipe with a long crack compared to one without you can hear the difference.