Document: NRC Regulatory Guide
Document ID: 0ae1e098-eccd-43e7-b12e-43b05aa1fe48
Document Type: regulatory_guide
Title: Safety-Related Concrete Structures for Nuclear Power Plants (Rev. 3)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1617/ML16172A240.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.142
CFR Part: 
CFR Title: 

Content:
ocalized area in the structure, (μ) = 3.0 DG-1283, Page 14 4.4.2 In Section F.3.7(a) and (b), when shear controls the design, the maximum permissible ductility ratios should be the following: a. When shear is carried by concrete alone, (μ) = 1.0 b. When shear is carried by a combination of concrete and stirrups, headed bars, or bent bars, (μ) = 1.3 4.4.3 In Section F.3.8(a) and (c), the maximum permissible ductility ratio in flexure should be as follows: a. When compression controls the design, as defined by a load-moment interaction diagram, (μ) = 1.0; b. When the compression load is less than 0.1f’c Ag or one-third of that which would produce balanced conditions, whichever is smaller, the permissible ductility ratio should be same as that given in Sections F.3.3 or F.3.4 of ACI 349-13; c. Vary linearly from (μ) = 1.0 to that given in Sections F.3.3 or F.3.4 of ACI 349-13 for conditions between those described in Section F.3.8(a) and (b). 4.4.4 The dynamic increase factors (DIFs) for flexure are acceptable as given in Section F.2.1 of ACI 349-13. However, DIFs for diagonal tension, direct shear, and bond strength should be as follows: a. DIF for diagonal tension and direct shear for reinforcing steel (stirrups) should be taken as 1.0, as specified in Table 5.4 of the ASCE “Report of the Committee on Impactive and Impulsive Loads,” Volume V, issued September 1980 (Ref. 25). b. DIF for diagonal tension and direct shear (punchout) and bond for reinforced and prestressed concrete should also be taken as 1.0, as specified in Table 5.4 of Ref. 25. 4.4.5 Section F.4.1 of ACI 349-13 allows the use of reinforcing steel with yield strength greater than 60 kilopounds per square inch. Regulatory Position 2.3 gives the NRC staff’s position on this subject. 4.4.6 The NRC staff will review the use of Section F.1.3 on a case-by-case basis. For example, the staff will review the use of Equations (RF-7) or (RF-8) instead of the shear provisions of ACI 349-13, as