Document: NRC Regulatory Guide
Document ID: a1541707-8144-409c-8842-4ea7d4b8ef4e
Document Type: regulatory_guide
Title: 10/2019 (Rev. 19)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1912/ML19128A244.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.147
CFR Part: 
CFR Title: 

Content:
e conditions for this guide.) 2/20/04 N-705 Evaluation Criteria for Temporary Acceptance of Degradation in Moderate Energy Class 2 or 3 Vessels and Tanks Section XI, Division 1 The ASME Code repair or replacement activity temporarily deferred under the provisions of this Code Case shall be performed during the next scheduled refueling outage for through-wall flaws. (Note: The NRC previously approved this Code Case without conditions; this is a new condition for this guide.) 11/10E N-711-1 Alternative Examination Coverage Requirements for Examination Category B-F, B-J, C-F-1, C-F-2, and R-A Piping Welds Section XI, Division 1 Code Case N-711-1 shall not be used to redefine the required examination volume for preservice examinations or when the postulated degradation mechanism for piping welds is primary water stress-corrosion cracking or crevice-corrosion degradation mechanisms. 0/17E N-749 Alternative Acceptance Criteria for Flaws in Ferritic Steel Components Operating in the Upper Shelf Temperature Range, Section XI, Division 1 In lieu of the upper shelf transition temperature, Tc, as defined in the Code Case, the following shall be used: Tc = 154.8 °F + 0.82 × RTNDT (in U.S customary units). Tc = 82.8 °C + 0.82 × RTNDT (in the International System of Units). Tc is the temperature above which the elastic plastic fracture mechanics (EPFM) method must be applied. Additionally, the NRC defines temperature Tc1 below which the linear elastic fracture mechanics (LEFM) method must be applied: Tc1 = 95.36 °F + 0.703 × RTNDT (in U.S customary units). Tc1 = 47.7 °C + 0.703 × RTNDT (in international system of units). Between Tc1 and Tc, although the fracture mode is in transition from LEFM to EPFM, users should consider whether it is appropriate to apply the EPFM method. Alternatively, the licensee may use a different Tc value if it can be justified by plant-specific Charpy curves. 3/16/12 RG 1.147, Rev. 19, Page 18 CODE CASE NUMBER TABLE 2 CONDITIONALLY ACCEPTABLE