Document: NRC Regulatory Guide
Document ID: 769c53ca-7692-4fdf-9301-9fd64e37aa8f
Document Type: regulatory_guide
Title: Evaluations of Explosions Postulated To Occur on Transportation Routes Near Nuclear Power Plants (Rev. 3)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML2110/ML21105A439.pdf
Revision Date: 2023-05
Chapter: 
Section ID: RG-1.91
CFR Part: 
CFR Title: 

Content:
ogies, as appropriate. Background To meet GDC 4 of Appendix A to 10 CFR Part 50 regarding dynamic effects, the SSCs important to safety of a nuclear power plant must be appropriately protected against dynamic effects that may result from equipment failures and events and conditions outside the nuclear power unit. The effects of explosions that are of concern in analyzing structural response to blasts are incident or reflected pressure (overpressure), dynamic (drag) pressure, blast-induced ground motion, blast-generated missiles, and thermal effects. It is the judgment of the NRC staff that overpressure effects are controlling for explosions of the magnitude considered in this guide and for the SSCs that must be protected against these effects. Drag pressure effects will be much smaller than those resulting from the wind loading assumed for the design-basis tornado. The effects of blast-generated missiles would be less than those associated with the blast overpressure levels considered in this guide. However, if the overpressure criterion described in this guide is exceeded, the effects of missiles should be considered. The effects of blast-induced ground motion at the overpressure levels considered in this guide should be less than those of the vibratory ground motion associated with a safe-shutdown earthquake. The effects of thermal exposure (radiative heat flux) is expected to be insignificant for concrete and steel structures but may be of concern for exposed plastic components. This RG describes four methods for determining distances from critical plant structures to a fixed facility or transportation route beyond which any explosion or fire that might occur is not likely to have an adverse effect on plant operation or prevent a safe shutdown. Beyond these distances, a detailed review of potential explosions or fire at the fixed facility or on these transportation routes would not be required. An acceptable method for establishing the distances beyond which no