Document: NUREG-0800
Document ID: 07e6bf87-51bb-4023-80a2-2a67ca4a9f80
Document Type: srp
Title: Revision 3 - March 2007
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0707/ML070740319.pdf
Revision Date: 2023-06
Chapter: 6
Section ID: 6
CFR Part: 
CFR Title: 

Content:
ctor operational modes of cold shutdown and refueling. 1. The on-line purge system should be designed in accordance with the following criteria: A. GDC 54 requires that the reliability and performance capabilities of containment isolation valves reflect the safety importance of isolating the systems penetrating the containment boundary; therefore, the performance and reliability of the purge system isolation valves should be consistent with the operability assurance program of SRP Section 3.10. The design basis for the valves and actuators should include the buildup of containment pressure for the LOCA break spectrum and the supply line and exhaust line flows as a function of time up to and during valve closure. B. The number of supply and exhaust lines should be limited to one supply line and one exhaust line to improve the reliability of the isolation function as required by GDC 54 and to facilitate compliance with the requirements of 10 CFR Part 50, Appendix K, for the containment pressure used in the evaluation of ECCS effectiveness and 10 CFR Part 100 for offsite radiological consequences. C. The size of the lines should not exceed about eight inches in diameter without detailed justification for larger line sizes to improve the reliability and performance capability of the isolation and containment functions as required by GDC 54 and to facilitate compliance with the requirements of 10 CFR Part 50, Appendix K, for the containment pressure used in evaluating ECCS effectiveness and 10 CFR Part 100 for the offsite radiological consequences. D. As required by GDC 54, the containment isolation provisions for the purge system lines should meet the standards appropriate to engineered safety features (i.e., quality, redundancy, testability and other appropriate criteria) to reflect the importance to safety of isolating these lines. GDC 56 establishes explicit requirements for isolation barriers in purge system lines. E. To improve the reliability of the isolation