Phased Array Ultrasonic Examination of Reactor Coolant System (Carbon Steel-to-CASS) Dissimilar Metal Weld Mockup Specimen

Technical Report · Mon Nov 23 00:00:00 EST 2015

DOI:https://doi.org/10.2172/1259948· OSTI ID:1259948

Crawford, S. L. ^[1]; Cinson, A. D. ^[2]; Diaz, A. A. ^[1]; Anderson, M. T. ^[1]

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1. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
2. US Nuclear Regulatory Commission (NRC), Washington, DC (United States)

In the summer of 2009, Pacific Northwest National Laboratory (PNNL) staff traveled to the Electric Power Research Institute (EPRI) NDE Center in Charlotte, North Carolina, to conduct phased-array ultrasonic testing on a large bore, reactor coolant pump nozzle-to-safe-end mockup. This mockup was fabricated by FlawTech, Inc. and the configuration originated from the Port St. Lucie nuclear power plant. These plants are Combustion Engineering-designed reactors. This mockup consists of a carbon steel elbow with stainless steel cladding joined to a cast austenitic stainless steel (CASS) safe-end with a dissimilar metal weld and is owned by Florida Power & Light. The objective of this study, and the data acquisition exercise held at the EPRI NDE Center, were focused on evaluating the capabilities of advanced, low-frequency phased-array ultrasonic testing (PA-UT) examination techniques for detection and characterization of implanted circumferential flaws and machined reflectors in a thick-section CASS dissimilar metal weld component. This work was limited to PA-UT assessments using 500 kHz and 800 kHz probes on circumferential flaws only, and evaluated detection and characterization of these flaws and machined reflectors from the CASS safe-end side only. All data were obtained using spatially encoded, manual scanning techniques. The effects of such factors as line-scan versus raster-scan examination approaches were evaluated, and PA-UT detection and characterization performance as a function of inspection frequency/wavelength, were also assessed. A comparative assessment of the data is provided, using length-sizing root-mean-square-error and position/localization results (flaw start/stop information) as the key criteria for flaw characterization performance. In addition, flaw signal-to-noise ratio was identified as the key criterion for detection performance.

• Research Organization: Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
• Sponsoring Organization: USDOE; USNRC
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 1259948
• Report Number(s): PNNL-24920; 453040374; TRN: US1601535
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
36 MATERIALS SCIENCE
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
CARBON STEELS
AUSTENITIC STEELS
ULTRASONIC TESTING
WELDED JOINTS
MOCKUP
REACTOR COOLING SYSTEMS
STAINLESS STEELS
DEFECTS
KHZ RANGE 100-1000
DETECTION
PERFORMANCE
SIGNAL-TO-NOISE RATIO
COMPARATIVE EVALUATIONS
PUMPS
ERRORS
FREQUENCY DEPENDENCE
INSPECTION
NOZZLES