September 26, 2019

Baseline Evaluation of Eddy Current Testing for PWSCC Susceptible Materials

Carol Nove
Michael Larche
Aaron Diaz
John Lareau
This technical letter report (TLR) summarizes technical efforts focused on assessments of eddy current testing (ET) examinations using various mockups for obtaining baseline surface and subsurface conditions on materials susceptible to primary water stress corrosion cracking (PWSCC). The scope of this work included nondestructive evaluation characterization of weld surfaces on mockups that were identified for application of various surface peening approaches. All of the work reported here was conducted prior to planned peening of these surfaces to evaluate pre-peening conditions, and subsequently compare the baseline ET results with post-peening conditions. The overall objective of this work was to demonstrate the effectiveness of employing ET for detecting near/sub-surface defects on mockups in support of peening assessments for surface stress improvement and mitigation of PWSCC in these materials. The U.S. Nuclear Regulatory Commission has communicated their expectations to industry for eddy current inspections of peened, inlayed, and onlayed dissimilar metal welds and is interested in better understanding detection performance and sensitivity of ET techniques to support the development of a technical foundation for detection and sizing limits, effective ET qualification requirements, alternate inspections or programs for evaluating PWSCC mitigation processes, and development of ET acceptance standards that can be referenced in the appropriate American Society of Mechanical Engineers Section XI Code Case (N-770-X). This TLR provides a technical discussion focused on the ET data obtained, the analysis, and conclusions drawn from surface examinations of various plate standards and actual components extracted from cancelled nuclear power plants.

Revised: September 26, 2019 | Published: September 17, 2019

Lareau J.P., M.R. Larche, A.A. Diaz, and C.A. Nove. 2019. Baseline Evaluation of Eddy Current Testing for PWSCC Susceptible Materials. PNNL-29113. Richland, WA: Pacific Northwest National Laboratory.