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U.S. Department of Energy
Office of Scientific and Technical Information

Acoustic emission/flaw relationship for in-service monitoring of nuclear pressure vessels. Quarterly report, April-September 1984. Volumes 3, 4

Technical Report ·
OSTI ID:6123462

Technical progress toward continuous acoustic emission monitoring of nuclear reactor pressure boundaries for flaw detection is described for this period. A draft report of ZB-1 vessel test results was completed. Growth of machined flaws was detected by AE during both 65/sup 0/C and 285/sup 0/C testing. A key result was clear detection of a natural crack in a fabrication weld by AE. Crack growth rates estimated from AE data compared well with measured crack growth rates for the machined defects. In service hydro test monitoring gave mixed results. Questionable vessel integrity as denoted by continued AE at pressure hold is readily detectable. With low overpressure (1.15 x operating pressure), flaws as deep as 70% through-wall did not produce significant AE. With higher overpressure (1.4 x operating pressure), flaws produced identifying AE. An engineering prototype AE monitor system has been completed for use in operational monitoring at Watts Bar Unit 1 reactor. A modified approach to crack growth AE signal identification is producing about 95% correct determinations on recorded waveforms from the ZB-1 vessel test. A report on results from AE monitoring hot functional testing at Watts Bar Unit 1 has been published.

Research Organization:
Pacific Northwest Labs., Richland, WA (USA)
DOE Contract Number:
AC06-76RL01830
OSTI ID:
6123462
Report Number(s):
NUREG/CR-3825-Vols.3-4; PNL-5125-Vols.3-4; ON: TI85009374
Country of Publication:
United States
Language:
English