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on 9/29/26 at 2:47 PM
Probabilistic fracture mechanics (PFM) addresses such questions as the likelihood that a crack in a pipe will be present, whether it is detected during a given inspection or whether it will grow to a large enough size to cause a leak or break. Therefore, PFM can be a key tool for leak-before-break (LBB) applications. A variety of PFM codes have been developed in OECD Nuclear Energy Agency (NEA) Member countries during the last four decades to support the continued safe operation of degraded, ageing components. However, these codes have been designed using different models and assumptions, because there are no generally accepted PFM guidance and acceptance criteria. Therefore, it is important to understand the effect of these differences.
Additionally, comparison and reconciliation between results from PFM and deterministic LBB approaches are also scarce. Accordingly, a PFM benchmark activity was conducted to address the following five objectives:
1. understand differences in PFM software design;
2. benchmark deterministic fracture mechanics models;
3. evaluate the effectiveness of leak detection (LD) in reducing failure probabilities;
4. reconcile deterministic LBB and PFM results;
5. evaluate the importance of two risk-significant parameters, such as in-service
inspection (ISI) and weld residual stress (WRS), in affecting failure probabilities.
