Document: NRC Regulatory Guide
Document ID: aa450282-f5b0-4dd2-b41a-917a7491deb2
Document Type: regulatory_guide
Title: Preparing Probabilistic Fracture Mechanics (Rev. 0)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML2133/ML21334A158.pdf
Revision Date: 2023-05
Chapter: 
Section ID: RG-1.245
CFR Part: 
CFR Title: 

Content:
..................................................... 16 2.7. Uncertainty Propagation .............................................................................................. 18 2.8. Convergence ................................................................................................................ 19 2.9. Sensitivity Analyses .................................................................................................... 21 2.10. Quantity of Interest Uncertainty Characterization ....................................................... 23 2.11. Sensitivity Studies ....................................................................................................... 24 RG 1.245 Revision 0, Page 6 B. DISCUSSION Reason for Issuance The NRC developed this RG to provide guidance for the use of PFM in regulatory applications. It is intended to ensure that the staff guidance is clear with regard to the contents of PFM regulatory applications. The use of this RG is anticipated to increase the efficiency of reviews for regulatory applications that use PFM as a supporting technical basis by providing a set of common guidelines for reviewers and licensees. Background In recent years, the NRC has observed an increase in the number of applications using PFM as a technical basis. The heightened focus on PFM is partly due to the increased emphasis on risk-informed regulation, but also because plant aging and new degradation mechanisms can be difficult to address using traditionally very conservative deterministic fracture mechanics. The increased use of PFM has also been facilitated by improvements in computational capability and the increased availability of PFM codes, such as Fracture Analysis of Vessels—Oak Ridge (FAVOR) (Ref. 12), Extremely Low Probability of Rupture (xLPR) (Ref. 13), and others. Furthermore, the NRC has used probabilistic fracture mechanics methods in developing regulatory positions, such as the alternate pressurized thermal shock (PTS)