Document: NUREG-0800
Document ID: c23d52ec-d83f-4468-b35e-e8c97fdf2f09
Document Type: srp
Title: CONTAINMENT ISOLATION SYSTEM
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070461.pdf
Revision Date: 2023-06
Chapter: 6
Section ID: 6.2.4
CFR Part: 
CFR Title: 

Content:
t boundary while it preserves the capability of the boundary to prevent or limit the escape of fission products that may result from postulated accidents. This SRP section provides guidance related to design requirements for containment isolation provisions, including the number and location of isolation valves, the actuation and control features for isolation valves, redundancy, valve actuation signals, and closure times. Meeting the requirements of GDC 16 provides assurance that the containment and its associated systems will act as an essentially leaktight barrier to prevent the uncontrolled release of radioactive materials to the environment in the event of an accident.67 5. Compliance with GDC 54, "Piping Systems Penetrating Containment," requires that piping systems that penetrate the primary reactor containment be provided with leak detection, isolation, and containment capabilities having redundancy, reliability, and performance capabilities that reflect the importance to safety of isolating these piping systems. GDC 54 applies to this SRP section because the reviewer evaluates the containment isolation system to ensure that valves in piping systems that penetrate the containment are designed to close reliably under accident conditions, thereby preventing the uncontrolled release of radioactive materials. To ensure the reliability these valves, SRP Section 6.2.4 provides guidance related to leak detection, redundancy, leakage testing, and functional testing. Regulatory Guides 1.11 and 1.141 provide guidance acceptable to the staff for isolating instrument lines that penetrate the containment and for fluid systems, respectively. Nonessential lines are automatically isolated by the containment isolation signal. Meeting the requirements of GDC 54 provides assurance that the containment isolation system will reliably isolate piping systems penetrating containment, as required.68 6. Compliance with General Design Criterion (GDC 55), "Reactor Coolant Pressure