Steam generator group project: Final report: Post-service baseline eddy current examination, Task 7

Technical Report · Thu Dec 01 04:00:00 EST 1988

DOI:https://doi.org/10.2172/6126244· OSTI ID:6126244

Doctor, P. G.; Birks, A. S.; Ferris, R. H.; Harty, H.; Spanner, G. E.

The Steam Generator Group Project (SGGP) is using a retired-from-service pressurized water reactor steam generator as a test bed to investigate the reliability of in-service nondestructive (NDE) eddy current inspections. This information will provide the technical basis for reccommended changes to the regulations concerning in-service inspections of steam generator tubes and tube plugging criteria. The estimates of inspection reliability are being made from NDE data collected during a series of round robin inspections of a subset of tubes from the generator. Segments of these tubes have been removed from the generator and are being destructively analyzed to determine the actual state of tube degradation. To determine NDE reliability, a large number of service-induced defects were needed in the set of tubes selected for the round robin inspections. Thus two complete baseline eddy current inspections were performed to identify those tubes with a high probability of containing defects. The results of the baseline inspections are described in this report. The baseline inspections were performed by field-experienced personnel using two different commercially-available multifrequency eddy current systems. The analysis of the results showed larger than expected differences in the detection of suspected wall-loss defects (indications) and the subsequent estimates of the depth of the defects. One inspection reported 773 outer-diameter (OD) indications and the other 1041. The detection agreement between teams, based on the reporting of the same indication, was 84% and 61% for the inspections with the fewer and larger numbers of indications, respectively. The sizes of the same indications reported by different teams were observed to be significantly different. 6 refs., 35 figs., 23 tabs.

• Research Organization: Nuclear Regulatory Commission, Washington, DC (USA); Pacific Northwest Lab., Richland, WA (USA)
• DOE Contract Number: AC06-76RL01830
• OSTI ID: 6126244
• Report Number(s): NUREG/CR-5087; PNL-5940; ON: TI89010786
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
210200* -- Power Reactors
Nonbreeding
Light-Water Moderated
Nonboiling Water Cooled
BOILERS
DATA
DEFECTS
EDDY CURRENT TESTING
ELECTROMAGNETIC TESTING
EXPERIMENTAL DATA
IN-SERVICE INSPECTION
INFORMATION
INSPECTION
MATERIALS TESTING
NONDESTRUCTIVE TESTING
NUMERICAL DATA
PWR TYPE REACTORS
REACTORS
STEAM GENERATORS
TESTING
TUBES
VAPOR GENERATORS
WATER COOLED REACTORS
WATER MODERATED REACTORS