Document: NUREG-0800
Document ID: 6237521d-c825-4ed6-8fb7-7b3b8019a3fc
Document Type: srp
Title: SYSTEM QUALITY GROUP CLASSIFICATION
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070297.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.2.2
CFR Part: 
CFR Title: 

Content:
lineated in detail the system quality group classification boundaries for systems important to safety. Each individual line on a diagram is checked to assure the accuracy of the assigned quality group classification, including branch lines such as vent lines, drain lines, fill lines, test lines, and sample lines. Changes in quality group classification are permitted normally only at valve locations, with the valve assigned the higher classification. A change in quality group classification with no valve present is permitted 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. The following fluid systems important to safety for pressurized water reactor (PWR) and boiling water reactor (BWR) plants are reviewed by the EMEB with regard to quality group 31 classification. FLUID SYSTEMS IMPORTANT TO SAFETY FOR PWR PLANTS32 Auxiliary Feedwater System Boron Thermal Regeneration System1,2 Boron Recycle System1,2 Chemical and Volume Control System Combustible Gas Control System 6 33 Compressed Air System 1,2,6 34 Condensate Storage System 1 35 Containment Cooling System Containment Isolation System 6 36 Containment Purge System Containment Spray System Emergency Core Cooling System Emergency Diesel Engine Fuel Oil Storage and Transfer System 6 37 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 2,6 38 Feedwater System3 Main Steam System3 Pressurizer Power-Operated Relief Valves (PORVs) (including associated components and block valves) 6 39 Process and Post-Accident Sampling Systems 3 40 Reactor Auxiliary Cooling Water Systems (e.g., Component Cooling Water and Essential Chilled Water Systems) 2 41 Reactor Coolant System Refueling Water Storage System 2 42 Residual Heat Removal System Spent Fuel Pool