Document: NRC Regulatory Guide
Document ID: 2704425a-c58a-45c4-93ab-8761721c3e7a
Document Type: regulatory_guide
Title: Evaluation of Reactor Pressure Vessels with Charpy Upper-Shelf Energy Less Than 50 Ft-Lb
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML0037/ML003740038.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.161
CFR Part: 
CFR Title: 

Content:
criterion given by Equation 2. The applied J integral is calculated for a series of flaw depths corresponding to increasing amounts of ductile flaw growth. The applied pressure, p, is set equal to the maximum accumulated pressure for Savice, Level A and B conditions, ps, with a safety factor, SF, equal to 1.25. The applied J-integral for Service Level A and B conditions may be calculated using Equations 6 through 10. Each pair of the applied J-integral and flaw depth is plotted on a crack driving force diagram to produce the 'The equations provided in Appendix B may be used if the transient temperature hstoy can be approxmatedI adequaty by either an exponential or a polynomial equatio. IV it cannot be approximated adequately, a mom rigorous approach should be used. Te omer code egmv iuAppeandix B is for general illustration licensees assume responslity for the correctness of the computer codes ty use. K 1.161-6 applied J-integral curve as illustrated in Figure 1. The mate riars J-R curve also is plotted on the crack driving force diagram. Flaw stbiity at a given applied load is demonstrated if the slope of the applied J-integral curve is less than the slope of the material's J-R curve at the equilibrium point on the J-R curve where the two curves intersect. 2.2 Level C Condition The acceptance criteria discussed in Regulatory Position 1 for Service Level C conditions are similar to those for Service Levels A and B, with the exceptions of the crack size to be considered and the safety factor applied to the pressure loading. For Service Level C conditions, flaw sizes up to one-tenth the base metal wall thickness, plus the clad thick ness t.L but with a total depth not to exceed 1.0 inch (2.54 cm), are to be considered. A safety factor of 1.0 is used for both pressure and thermal loading. As with the Service Level A and B criteria, for Service Level C it must be demonstrated that the applied J is less than the material's fracture resistance at a crack extension of 0.1