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:
2.1 Hydrodynamic loads associated with seismic loads (i.e., the impulsive and sloshing loads for fluids in tanks) are to be considered as Ess in load combinations (C9-4) and (C9-8). Hydrodynamic loads associated with seismic loads are to be considered as Eo in load combinations (C9-2), (C9-7), and (C9-10). All other hydrodynamic loads should be taken as Yj in load combinations (C9-7) and (C9-8). 4.2.2 Design for loads due to accidental explosions, or accidental vehicle impacts or accidental small aircraft impacts should use load combination (C9-5), with those loads used in lieu of Wt, with the further guidance provided in ACI 349-13, Appendix F. RG 1.217 covers the effects from beyond-design-basis large aircraft impacts. 4.2.3 Use φ = 0.60 in C.9.3 and RC.9.3 of ACI 349-13 for shear critical members, reflecting the lower ductility of shear critical members than flexure-critical members. This is identical to regulatory position 3.7. 4.3 Appendix D, “Anchoring to Concrete” RG 1.199 endorses Appendix D with exceptions. 4.4 Appendix F, “Special Provisions for Impulsive and Impactive Effects” The NRC staff generally finds acceptable the local exceedance of section strengths in accordance with Appendix F under the impactive and impulsive loadings described in Sections F1.4 and F1.5 (e.g., accidental explosions and vehicle or small aircraft impacts, turbine missiles, and a localized pressure transient during an explosion). The permissible ductility in Appendix F is acceptable with the following exceptions: 4.4.1 In Section F.3.5, the maximum permissible ductility ratios (μ) when a concrete structure is subjected to a pressure pulse caused by compartment pressurization or blast loading should be the following: a. For the structure as a whole, (μ) = 1.0 b. For a localized 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