Progress in the Reliable Inspection of Cast Stainless Steel Reactor Piping Components
Studies conducted at the Pacific N¬orthwest National Laboratory (PNNL) in Richland, Washington, have focused on assessing the effectiveness and reliability of novel NDE approaches for the inspection of coarse-grained, cast stainless steel reactor components. The primary objective of this work is to provide information to the United States Nuclear Regulatory Commission (US NRC) on the utility, effec¬tiveness and reliability of ultrasonic testing (UT) and eddy current testing (ET) inspection techniques as related to the inservice ultrasonic inspec¬tion of primary piping components in pressurized water reactors (PWRs). This paper describes progress, recent developments and results from assessments of three different NDE approaches including ultrasonic phased array inspection techniques, eddy current testing for surface-breaking flaws, and a low-frequency ultrasonic inspection methodology coupled with a synthetic aperture focusing technique (SAFT). Westinghouse Owner’s Group (WOG) cast stainless steel pipe segments with thermal and mechanical fatigue cracks, PNNL samples containing thermal fatigue cracks and several blank spool pieces were used for assessing the inspection methods. Eddy current studies were conducted on the inner diameter (ID) surface of piping specimens while the ultrasonic inspection methods were applied from the outer diameter (OD) surface of the specimens. The eddy current technique employed a Zetec MIZ-27SI Eddy Current instrument and a Zetec Z0000857-1 cross point spot probe with an operating frequency of 250 kHz. In order to reduce noise effects, degaussing of a subset of the samples resulted in noticeable improvements. The phased array approach was implemented using an R/D Tech Tomoscan III system operating at 1 MHz, providing composite volumetric images of the samples. The low-frequency ultrasonic method employs a zone-focused, multi-incident angle inspection protocol (operating at 250-500 kHz) coupled with SAFT for improved signal-to-noise and advanced imaging capabilities. A variety of dual-element, custom designed low-frequency probes (fixed-wedge and variable angle configurations) were employed in laboratory trials. Re¬sults from laboratory studies for assessing detection, localization and length sizing effectiveness are discussed. This work was sponsored by the U.S. Nuclear Regulatory Commission under Contract DE-AC06-76RLO 1830; NRC JCN Y6604; Mr. Wallace Norris, Program Monitor.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 948428
- Report Number(s):
- PNNL-SA-44729; 401001060; TRN: US0901636
- Resource Relation:
- Conference: 18th International Conference on Structural Mechanics in Reactor Technology (SMiRT 18), 4178-4189, Art No. SMiRT18-O04-6
- Country of Publication:
- United States
- Language:
- English
Similar Records
Challenges and Capabilities for Inspection of Cast Stainless Steel Piping
Using Low-Frequency Phased Arrays to Detect Cracks in Cast Austenitic Piping Components
Related Subjects
36 MATERIALS SCIENCE
APERTURES
DEFECTS
DETECTION
EDDY CURRENT TESTING
EDDY CURRENTS
FOCUSING
PROBES
PWR TYPE REACTORS
REACTOR COMPONENTS
REACTOR TECHNOLOGY
RELIABILITY
STAINLESS STEELS
THERMAL FATIGUE
ULTRASONIC TESTING
ULTRASONIC WAVES
Ultrasonic
Phased Array
Eddy Current
SAFT
Cast Stainless Steel
Coarse Grained Material