Acceptance criterion for probabilistic structural integrity assessment: Prediction of the failure pressure of steam generator tubing with fretting flaws

• Two loop analysis to deal with uncertainties in the structural integrity assessment of steam generator tubing.
• The comparison between deterministic assessment and probabilistic assessment with varying confidence levels.
• Two acceptance standards for the probabilistic structural integrity assessment.

A probabilistic structural integrity assessment framework utilizing a two-loop Monte Carlo simulation process is proposed. The process and interpretation of the results are demonstrated using an example of Steam Generator (SG) tubing with fretting flaws. Acceptance standards established using a 95/90/90 criterion (which represents 95% probability at 90th percentile with 90% one-sided confidence) is proposed and compared with the generally accepted deterministic and traditional probabilistic acceptance standards.