Document: NUREG-0800
Document ID: fce5c014-cdea-4bf2-83f9-535d051f0f3b
Document Type: srp
Title: MISSILES GENERATED BY NATURAL PHENOMENA
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070375.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.5.1.4
CFR Part: 
CFR Title: 

Content:
sis tornado parameters, including maximum wind speed, as part of its primary review responsibility for SRP Section 2.3.1.10 For those areas of review identified above as being part of the review under other SRP sections, the acceptance criteria and their methods of application are contained in the referenced SRP sections.11 II. ACCEPTANCE CRITERIA 12 The acceptability of the assessment as described in the applicant's Safety Analysis Report (SAR) is based on compliance with: General Design Criteria 2 and 4 as it relatesthey relate to the capability of structures, systems, 13 and componentsSSC important to safety to withstand the effects of tornadoes and other 14 15 natural phenomena. Acceptance is based on meeting the guidelines of Regulatory Guide 1.76 and 1.117. New applications may utilize a maximum tornado wind speed, used in the evaluation of missiles generated by the design-basis tornado, of at least 482 km/hr (300 mph) in lieu of the guidance on tornado wind speeds contained in Regulatory Guide 1.76 (see References 7 and 8).16 The methodology of identification of appropriate design basis missiles generated by natural phenomena shall be consistent with the acceptance criteria defined for the evaluation of potential accidents from external sources in SRP Section 2.2.3. Technical Rationale:17 The technical rationale for application of the above acceptance criteria to missiles generated by natural phenomena is discussed in the following paragraphs. 1. GDC 2 establishes requirements regarding the ability of SSC important to safety to withstand natural phenomena, including a tornado, without the loss of capability to perform their safety functions. Application of GDC 2 ensures that the chosen design basis reflects the most severe of the natural phenomena historically reported for the site and surrounding region. Regulatory Guide 1.76 describes a design-basis tornado based upon WASH-1300, "Technical Basis for Interim Regional Tornado Criteria" (Reference 6) that is