Document: NUREG-0800
Document ID: 025e5140-015c-4e77-ad4f-ff52a81956fe
Document Type: srp
Title: WIND LOADING
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0705/ML070570001.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.3.1
CFR Part: 
CFR Title: 

Content:
etermining these site-related parameters, are stated in SRP Sections 2.3.1 and 2.3.2. The approved values of these parameters should serve as basic input to the review and evaluation of the structural design procedures. 3. The procedures used to transform the wind speed into an equivalent pressure to be applied to structures and parts, or portions of structures, as delineated in American Society of Civil Engineers/Structural Engineering Institute (ASCE/SEI) 7-05, “Minimum Design Loads for Buildings and Other Structures,” are acceptable. In particular, the procedures used are acceptable if found in accordance with the following: A. For a design wind speed, V, the velocity pressure, qz, evaluated at height, z, is given by: qz = 0.00256 KzKdtKdV2I (lb/ft2) where: Kz = velocity pressure exposure coefficient evaluated at height, z, as defined in ASCE/SEI 7-05, Table 6-3, but not less than 0.87 Kdt = topographic factor equal to 1.0 Kd = wind directionality factor equal to 1.0 V = design wind speed in miles per hour (mi/h) as stated in SRP Section 2.3.1 I = importance factor equal to 1.15 3.3.1-4 Revision 3 - March 2007 B. For each wind direction considered, the upwind exposure category should be based on ground surface roughness that is determined from natural topography, vegetation, and constructed facilities. Surface roughness C is defined as open terrain with scattered obstructions having heights generally less than 30 ft. This category includes flat open country, grasslands, and all water surfaces in hurricane prone regions. Because most nuclear power plants are located in relatively open country, Kz values in Table 6-3 should be selected from the Exposure C column. The definition of Exposure C is provided in ASCE/SEI 7-05, Section 6.5.6.3. C. Design wind loads should be determined in accordance with the following sections in ASCE/SEI 7-05, as applicable. i. Section 6.5.12 – Design Wind Loads on Enclosed and Partially Enclosed Buildings ii. Section 6.5.13 -