Document: NUREG-0800
Document ID: 22884f18-189e-46a8-81b2-45db11edf145
Document Type: srp
Title: SYSTEM QUALITY GROUP CLASSIFICATION
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML1422/ML14227A641.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.2.2
CFR Part: 
CFR Title: 

Content:
ed instrument sensing lines B,C (i) RG 1.151 Ultimate heat sink and supporting systems C (j) SRP Section 9.2.5, RG 1.72 Main steam, essential portions B SRP Section 10.3 Circulating water system D SRP 10.4.5 PWR safety-related steam generator blowdown B SRP 10.4.8 NOTES: a. RG 1.7, “Control of Combustible Gas Concentrations in Containment,” describes acceptable methods for the control of combustible gas in containment, with consideration of 10 CFR 50.44, “Standards for Combustible Gas Control System in Light-Water-Cooled Power Reactors.” b. SRP Section 6.2.4 contains guidance related to classification of containment isolation systems. Containment isolation system components (e.g., isolation barriers) are normally classified as Quality Group B unless their service function dictates that Quality Group A standards be applied. RGs 1.11 and 1.141 are cited in SRP Section 6.2.4 and describe methods acceptable to the NRC staff for complying with the Commission’s requirements with respect to containment isolation of fluid systems. c. RG 1.11, “Instrument Lines Penetrating Primary Reactor Containment,” describes a suitable basis that may be used to implement containment isolation design criteria for instrument lines. d. Branch Technical Position 6-3 describes methods for determining bypass leakage paths in dual containment plants. Position B.9.B indicates that closed systems proposed as leakage boundaries to preclude bypass leakage should be designed in accordance with Quality Group B standards, as defined by RG 1.26, “Quality Group Classification and Standards for Water-, Steam-, and Radioactive-Waste-Containing Components of Nuclear Power Plants,” but that systems designed to Quality Group C or D standards that qualify as closed systems to preclude bypass leakage will be considered on a case-by-case basis. e. RG 1.137, “Fuel Oil Systems for Standby Diesel Generators,” describes a method acceptable for complying with regulations regarding fuel-oil