Document: NUREG-0800
Document ID: 274f0789-5956-4979-b7da-3b44ddf985d4
Document Type: srp
Title: TORNADO LOADS
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0705/ML070570002.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.3.2
CFR Part: 
CFR Title: 

Content:
cated. If venting is adopted as a way to reduce the atmospheric pressure change effect on a structure, the review will be performed on a case-by-case basis. D. Tornado-Generated Missile Impact Effects Tornado-generated missile characteristics and the design-basis tornado missile spectrum are provided in RG 1.76. The acceptance criteria for transforming tornado-generated missile impact into equivalent static loads on structures are delineated in SRP Section 3.5.3, subsection II. 3.3.2-6 Revision 3 - March 2007 E. Combined Tornado Effects After tornado-generated wind effects, Ww, atmospheric pressure change effects, Wp, and missile impact effects, Wm, are determined, the combination thereof should then be established in a conservative manner for structures. An acceptable method of combining these effects and establishing the total tornado load on a structure is as follows: Wt = Wp Eq. 1 Wt = Ww + 0.5 Wp + Wm Eq. 2 where: Wt = total tornado load Ww = load from tornado wind effect Wp = load from tornado atmospheric pressure change effect Wm = load from tornado missile impact effect 4. The information provided to demonstrate that failure of any structure or component not designed for tornado loads will not affect the capability of other SSCs to perform necessary safety functions, is acceptable if found in accordance with either of the following: A. The postulated failure or collapse of structures and components not designed for tornado loads, including missiles, can be shown not to result in any structural or other damage to safety-related structures, systems, or components. B. Safety-related structures are designed to resist the effects of the postulated structural failure, collapse, or generation of missiles from structures and components not designed for tornado loads. Technical Rationale The technical rationale for application of these acceptance criteria to the areas of review addressed by this SRP section is discussed in the following paragraphs: 1. Compliance with