Document: NUREG-0800
Document ID: 362175ab-e7ce-488e-8515-4d4b3de493c7
Document Type: srp
Title: MISSILES GENERATED BY EXTREME WINDS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1304/ML13043A004.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.5.1.4
CFR Part: 
CFR Title: 

Content:
in the following paragraphs: 1. GDC 2 establishes requirements regarding the ability of SSCs important to safety to withstand the effects of natural phenomena without the loss of capability to perform their safety functions. With respect to wind and missile loads, the GDC 2 requirement that SSCs important to safety be designed to withstand the effects of the most severe natural phenomena that have been historically reported for the site and surrounding area is accounted for by considering the wind and missile loads associated with the 10-7 per year design-basis tornado and hurricane specified in RG 1.76 and RG 1.221, respectively. Designing a nuclear power plant to withstand the design-basis tornado and hurricane wind speeds and missiles discussed in RG 1.76 and RG 1.221 ensures that SSCs important to safety will be capable of performing their safety functions, and there will be no undue risk to the health and safety of the public in the event of these design-basis wind conditions. Evolutionary reactors should be designed based on regional wind speeds corresponding to strike probability of less than or equal to 10-7 per year, as defined in RG 1.76 and RG 1.221. 2. GDC 4 establishes requirements regarding the ability of SSCs important to safety to be protected from dynamic effects, including the effects of missiles, from events and conditions outside the nuclear unit. Tornadoes and hurricanes are events outside the nuclear unit that may result in dynamic effects, including the effects of missiles; therefore, this criterion applies to the assessment of missiles generated by tornado and hurricane winds. Nuclear power plant design must consider the impact of direct action of tornado wind and the moving ambient pressure field, as well as the impact of tornado-generated missiles. Hurricane effects considered in the design should include combinations of hurricane wind effects and hurricane-generated missile impact effects. Protection from a spectrum of missiles with the