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:
elopment that integrates implications for the general use of, for example, crack control, material and component ductility, deflection limits, over-strength factors, and strength-reduction factors, is ongoing and, therefore, its use is not generically endorsed. 2.4 Regulatory Position 2.4 endorses the provisions in paragraphs (a) and (b) of Section 21.1.5.1 in ACI 349-13 for American Society of Testing and Materials (ASTM) A615 (Ref. 14) Grade 60 reinforcement and provides conditions for minimum acceptable elongation. The conditions for DG-1283, Page 5 minimum acceptable elongation are those in ASTM A706 for Grade 60 (Ref. 15) deformed reinforcement. 2.5 For deep beams, ACI 349-13 incorporates Section 11.7 of ACI 318-08 by reference. For deep beams, the minimum area for shear reinforcement (Av), perpendicular to the flexural tension reinforcement, in Section 11.7.4 of ACI 318-08 has a lower limit of not less than 0.0025bws. The minimum area for shear reinforcement (Avh), parallel to the flexural tension reinforcement for deep beams in Section 11.7.5 of ACI 318-08 has a lower limit of not less than 0.0015bws2. For better control of the growth and width of diagonal cracks, Regulatory Position 2.5 increases the area of shear reinforcement parallel to the flexural tension reinforcement to 0.0025bws2. 2.6 On the tension face of a structural slab, wall, or shell, the NRC staff does not endorse the “one-third greater than that required by analysis” rule for minimum reinforcement in Section 7.12.4 of ACI 349-13. This provision is not supported by sufficient justification in the commentary of ACI 349-13. 2.7 Section 7.12.4 of ACI 349-13 does not specifically address the minimum reinforcement for a foundation base mat. Regulatory Position 2.7 specifies the minimum reinforcement requirement for a foundation base mat. 2.8 Section 11.9 of ACI 349-13 incorporates by reference Section 11.9.1 of ACI 318-08 for the design of shear forces perpendicular to the face of the wall.