Document: NUREG-0800
Document ID: 632e6c59-03bd-4648-b0b3-e8b2efd6fa04
Document Type: srp
Title: CONTAINMENT ISOLATION SYSTEM
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0703/ML070380197.pdf
Revision Date: 2023-06
Chapter: 6
Section ID: 6.2.4
CFR Part: 
CFR Title: 

Content:
elease of radioactive materials to the environment. 2. GDC 2, "Design Bases for Protection Against Natural Phenomena," requires that safety-related SSCs be designed to withstand the effects of natural phenomena like earthquake, tornado, hurricane, flooding, tsunami, and seiche without loss of capability to perform safety functions. GDC 2 applies to this SRP section because the reviewer evaluates the containment isolation system for its capability to isolate the containment under accident conditions (e.g., LOCA) combined with severe natural phenomena. RG 1.29 provides guidance acceptable to the staff for developing designs with the capability to withstand earthquakes. Compliance with GDC 2 requirements provides reasonable assurance that the containment will act as an essentially leak-tight barrier and prevent the release of radioactive materials to the environment under all plausible conditions. 3. GDC 4, "Environmental and Dynamic Effects Design Bases," requires that safety-related SSCs (A) be designed to accommodate the effects of, and be compatible with, environmental conditions of normal operation, maintenance, testing, and postulated accidents (including LOCAs) and (B) be protected appropriately against dynamic effects (including those of missiles, pipe whipping, and discharging fluids) of equipment failures and events and conditions outside the nuclear power unit. GDC 4 applies to this SRP section because the reviewer evaluates the containment isolation system for its capability to perform its isolation function at all times in any environmental condition to which the system's components may be exposed, including dynamic effects. BTP 6-4 provides guidance as to dynamic effects that should be considered in the design of containment purge and vent valves. Compliance with GDC 4 requirements provide reasonable assurance that the containment isolation system has the capability to perform its safety function of containment isolation and to prevent the release of