Document: NUREG-0800
Document ID: 6c5a07e2-91cf-49ae-a450-62551ed6bcef
Document Type: srp
Title: CONTAINMENT ISOLATION SYSTEM
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0523/ML052340703.pdf
Revision Date: 2023-06
Chapter: 6
Section ID: 6.2.4
CFR Part: 
CFR Title: 

Content:
in the automatic reopening of containment isolation valves. Reopening of containment isolation valves should require deliberate operator action. In addition, ganged reopening of containment isolation valves is not acceptable. Reopening of isolation valves must be performed on a valve-by-valve basis, or on a line-by-line basis, pro- vided that electrical independence and other single-failure criterion continue to be satisfied. Administrative provisions to close all isolation valves manually before resetting the isolation signals is not an acceptable method of meeting this design requirement. III. REVIEW PROCEDURES The procedures described below provide guidance on review of the containment isolation system. The reviewer selects and emphasizes material from the review procedures as may be appropriate for a particular case. Portions of the review may be done on a generic basis for aspects of containment isolation common to a class of containments, or by adopting the results of previous reviews of plants with essentially the same containment isolation provisions. Upon request from the primary reviewer, other review branches will provide input for the areas of review stated in subsection I of this SRP section. The primary reviewer obtains and uses such input as required to assure that this review procedure is complete. The CSB determines the acceptability of the containment isolation system by comparing the system design criteria to the design requirements for an engi- neered safety feature. The quality standards and the seismic design classification of the containment isolation provisions including the piping penetrating the containment, are compared to Regulatory Guides 1.26 and 1.29, respectively. 6.2.4-8 Rev. 2 - July 1981 The CSB also ascertains that no single fault can prevent isolation of the con- tainment. This is accomplished by reviewing the containment isolation provisions for each line penetrating the containment to determine that two isolation bar- riers in