Document: NUREG-0800
Document ID: 80f85c58-62f4-4c36-99a0-9fc302a92188
Document Type: srp
Title: STRUCTURES,
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052340540.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.5.2
CFR Part: 
CFR Title: 

Content:
or shutdown, and for performing accident prevention or mitigation functions. The informa- tion provided in the SAR pertaining to SSC design bases, design criteria, descriptions and safety evaluations, together with the system and component characteristic tables and safety classification tables are reviewed to iden- tify safety functions performed by the SSC. In general, the safety functions to be performed by the SSC in various designs remain essentially the same. However, the location or arrangement of the SSC and the methods used vary from plant to plant depending upon the individual designer. The reviewer identi- fies variations in design and evaluates them on a case-by-case basis. The second step in the review is to determine the SSC, or portions of SSC, that require protection against externally generated missiles. The reviewer uses engineering judgment and the results of failure modes and effects ana- lyses in conjunction with the results of reviews under other SRP sections for specific SSC in determining the need for missile protection. Most safety- related systems are located within structures that are resistant to external missiles by virtue of design for other purposes (e.g., primary containment), 3.5.2-2 Rev. 2 - July 1981 or because the structures are constructed specifically to withstand missiles. Systems and components located within such structures are considered ade- quately protected. The reviewer concentrates his attention on safety-related SSC located outside such structures and on penetrations and access openings in the structures. Essential service water piping and components, storage tanks, and ultimate heat sink components are examples of SSC typically located out- side missile-resistant structures. Depending on the nature and source of the externally generated missiles, protection may be provided by missile barriers for individual components, by locating independent redundant systems in com- partments located in a missile protected structure,