Development of the improved probabilistic fracture mechanics analysis code: VINTIN

An advanced probabilistic fracture mechanics (PFM) code for pressurized thermal shock analysis was developed. Based on the detailed review of the existing PFM codes, several improvements in deterministic and probabilistic analysis modules were incorporated into the VINTIN (Vessel INTegrity analysis INner flaws) code to enhance the accuracy and applicability. Especially, to calculate the applied stress intensity factors of semi-elliptical surface flaws, influence coefficients database for various flaw shapes, depths, and orientations were utilized. Aslo, clad stress and weld residual stress analysis modules were added. In probabilistic analysis, various options in flaw arrest check, reference fracture toughness curve, and spatial distribution of fluence were included to enhance the flexibility in the analysis. The analysis results of the VINTIN and other leading PFM codes for a hypothetical PTS transient were compared and found to be comparable