Document: NRC Regulatory Guide
Document ID: 4f130c35-25dc-4950-b437-3801efdab5f6
Document Type: regulatory_guide
Title: Protection Against Extreme Wind Events and Missiles for Nuclear Power Plants (Rev. 2)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML1435/ML14356A107.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.117
CFR Part: 
CFR Title: 

Content:
ION Purpose This regulatory guide describes an approach that the staff of the U.S. Nuclear Regulatory Commission (NRC) considers acceptable for identifying those structures, systems, and components of light-water-cooled reactors that should be protected from the effects of the worst case extreme winds (tornados and hurricanes) and wind-generated missiles, and remain functional. Applicable Rules and Regulations • General Design Criterion 2, “Design Bases for Protection against Natural Phenomena,” of Appendix A, “General Design Criteria for Nuclear Power Plants,” to Title 10 of the Code of Federal Regulations (10 CFR) Part 50, “Domestic Licensing of Production and Utilization Facilities” (Ref. 1), requires, in part, that structures, systems, and components important to safety be designed to withstand the effects of natural phenomena such as tornadoes and hurricanes without loss of capability to perform their safety functions. Criterion 2 also requires that the design bases for these structures, systems, and components reflect (1) appropriate combinations of the effects of normal and accident conditions with the effects of natural phenomena, and (2) the importance of the safety functions to be performed. Related Guidance • RG 1.76, “Design-Basis Tornado and Tornado Missiles for Nuclear Power Plants,” (Ref. 2), provides a method to define design-basis tornado and design-basis tornado-generated missiles that a nuclear power plant should be designed to withstand. DG-1313, Page 2 • RG 1.221, “Design-Basis Hurricane and Hurricane Missiles for Nuclear Power Plants,” (Ref. 3) provides a method in selecting the design-basis hurricane wind speed and hurricane-generated missiles that a new nuclear plant should be designed to withstand. • RG 1.117 “Tornado Design Classification,” Rev. 1 (Ref. 4), describes a method acceptable to the NRC staff for identifying those structures, systems, and components of light-water-cooled reactors that should be