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:
fined by Regulatory Guide 1.26, 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.172 (5) Reg. Guide 1.137 describes a method acceptable for complying with regulations regarding fuel-oil systems for standby diesel generators. The Reg. Guide describes positions with respect to the design and fabrication of diesel fuel oil systems which are supplemental to those indicated by the Quality Group C classification including the application of additional standards.173 (6) SRP Section 9.3.3 provides criteria used to determine the safety-related portions of the equipment and floor drainage system and indicates that the safety-related portions of the system are verified to be classified Quality Group C or higher.174 (7) Reg. Guide 1.96 describes an acceptable basis for evaluating the need for, and design of, leakage control systems for BWR main steam isolation valves. Position C.1 of the Reg. Guide describes the appropriate classification for leakage control systems as Quality Group B, with the exception of the unisolable portion of the system connected to the RCPB, which should be classified as Quality Group A. Appendix A of the Reg. Guide describes measures supplemental to the ASME Code to be applied for Quality Group A portions of the system.175 (8) Components of the reactor coolant system, including those comprising the RCPB, should be quality group classified accordingly. PORVs and associated components should be classified as safety-related where required to perform a safety-related function (e.g., mitigation of a design-basis steam generator tube rupture accident, low temperature overpressure protection of the reactor vessel, and/or plant cooldown as described in Generic Letter 90-06). As described in Reference 12, the safety-related classification 3.2.2-27 DRAFT Rev. 2 - April 1996 should address redundant and diverse control systems designed to seismic