Document: NUREG-0800
Document ID: c3ba2b86-3805-4144-9775-cd35b7bffe2d
Document Type: srp
Title: SYSTEM QUALITY GROUP CLASSIFICATION
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1608/ML16084A884.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.2.2
CFR Part: 
CFR Title: 

Content:
—should be located downstream of a valve that is either normally closed or capable of automatic closure when the safety function is required. This valve should be assigned the higher classification. Any change in quality group classification with no valve present is considered acceptable only when it can be demonstrated that the safety function of the system is not impaired by a failure on the lower-classification side of the boundary. Further guidance on this topic is provided in RG 1.26. 3.2.2-9 Revision 3 – July 2016 5. The following fluid systems are examples of those that are reviewed by the staff with regard to quality group classification. Typical system names are provided below, based on historical staff reviews of prior applications. It should be noted that systems whose function is equivalent to those described in RG 1.26 may not be identified by these names, but the staff should consider the systems and functions in a given application for consistency with these general principles when evaluating whether the classifications are appropriate. Pressurized-Water Reactor Fluid Systems Subject to Quality Group Classification • auxiliary feedwater system • boron thermal regeneration system1, 2 • boron recycle system 1, 2 • chemical and volume control system • combustible gas control system 1, 3 • compressed air system 1, 2, 3 • condensate storage system 1 • containment cooling system • containment isolation system 3 • containment purge system • containment spray system • emergency core cooling system • emergency diesel engine fuel oil storage and transfer system 3 • emergency diesel engine cooling water system • emergency diesel engine starting system • emergency diesel engine lubrication system • emergency diesel engine combustion air intake and exhaust system • equipment and floor drainage system 2, 3 • feedwater system 4 • main steam system 4 • pressurizer power-operated relief valves (PORVs) (including associated