Probabilistic Fracture Mechanics Codes for Piping International Benchmark – Part 1: Deterministic Comparisons

Abstract

This paper describes deterministic benchmark comparisons of 14 probabilistic fracture mechanics (PFM) codes. The benchmark problem focused on determining the leak-before-break behavior of a nickel-based alloy weld in a large-bore piping system of a pressurized-water reactor. The modeled degradation mechanism was primary water stress-corrosion cracking (PWSCC). The benchmark problem was deterministically analyzed with the PFM codes using their models for crack growth rates, stress-intensity factors, crack-opening displacements (CODs), crack transition from inside surface-breaking cracks to through-wall cracks, leak rates, and crack stability. Several output quantities of interest relevant to leak-before-break behavior were then compared. Other outputs as a function of the simulated component operating time were also compared, including the crack lengths and depths, stress-intensity factors, inside and outside surface CODs, and leak rates. An interpretation of these comparisons is provided in relation to the underlying models to better understand the effects of the different modeling approaches. Insights from this study will be used to inform probabilistic comparisons of the PFM codes, which will be presented in a subsequent paper.