Fabrication Flaw Density and Distribution in Piping Weldments
The U.S. Nuclear Regulatory Commission supported the Pacific Northwest National Laboratory (PNNL) to develop empirical data on the density and distribution of fabrication flaws in nuclear reactor components. These data are needed to support probabilistic fracture mechanics calculations and studies on component structural integrity. PNNL performed nondestructive examination inspections and destructive testing on archived piping welds to determine the fabrication flaw size and distribution characteristics of the flaws in nuclear power plant piping weldments. Eight different processes and product forms in piping weldments were studied including wrought stainless steel and dissimilar metal weldments. Parametric analysis using an exponential fit was performed on the data. Results were created as a function of the through-wall size of the fabrication flaws as well as the length distribution. The results are compared and contrasted with those developed for reactor pressure vessel processes and product forms. The most significant findings were that the density of fabrication flaws versus through-wall size was higher in piping weldments than that for the reactor pressure vessel weldments, and the density of fabrication flaws versus through-wall size in both reactor pressure vessel weld repairs and piping weldments were greater than the density in the original weldments. Curves showing these distributions are presented.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 1012896
- Report Number(s):
- PNNL-SA-66046; 401001060; TRN: US1102384
- Resource Relation:
- Conference: 20th International Conference on Structural Mechanics in Reactor Technology (SMiRT 20), August 9-14, 2009, Espoo, Finland, 257:393
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
36 MATERIALS SCIENCE
DEFECTS
DESTRUCTIVE TESTING
DISTRIBUTION
FABRICATION
FRACTURE MECHANICS
NUCLEAR POWER PLANTS
PARAMETRIC ANALYSIS
PRESSURE VESSELS
REACTOR TECHNOLOGY
REACTORS
STAINLESS STEELS
fabriation flaws
piping weldments
austenitic stainless steel
dissimilar metal welds